Havaianas

Our commercializeing case study refers at the develop of the Italian market of Havaianas flip-flops Description of Product In Brazil Havaianas harvest-home is well know (second only to Coca Cola). Its a mass market product, a commodity Flip-flops features Comfortable Durable Out of time Practical aesthetically beautiful Cheap Two main(prenominal)s merchandises A usanceal segment exchangeable beach, leisure and sport A niche segment, the surf market Main Marketing Problems In Italy among consumers only 12. 5% indicated Havaianas as first put up of flip flops designed Find the right market segment over turn awaying the competitors involve to consumers the important attributes, technical and horny, of the product Targeting The product is suitable for everyone, but peculiarly for consumers aged from 16 to 40 In this work we have determine three main consumers categories Trendy Functional Not interested 10% 75% 15% Swot Analisys OPPORTUNITY Width of the target ki ng to develop authentic connections with a product rich in meanings index to enter niche marketsSTRENGTHS Versatility of the product High Quality (natural materials) Wide range of models -Possibility of limited Editions Product THREATS -Competition in precede and parallel importation of products with low repre move (China) -No barriers to entry -Risk of becoming a passing fashion brand -Existence of direct competitors that too produce clothing lines WEAKNESSES Poor presence in whatsoever markets Low brand awareness Its absent the perception of the whole tone of the product by the consumer Seasonality It is not considered a technical productTraditional Market positioning Market Positioning-Competitors Reef, the market leader, has a marketing outline aimed at consumers more and more sophisticated which seem to communicate a feeling of continuous inquiry and need of something more distinctive Sundek leverages its performance of summer clothing to also sell footwea r and flipflops As flip-flops for the pool, locker room and sports in commonplace brands such as Nike & Adidas provide an superiorer level of technicality If we consider the Havaianas as a sandal for a night out or more often than not for living the city, then the competition is with brands such as D&G, Gucci, Prada Market Positioning-Havaianas Havaianas is on the market in a position straddling Functionality and Fashion (impossible for Reef) to a point less evolved of its direct competitor The fashion factor for Havaianas is the ability to sell a cheap product that capture the customers with the history, the sense of immunity and the possibility to express yourself which are the guidelines that, since the beginning, distinguish this product breaker Market Market PositioningCompetitors The competitors, althougth with assorted placements, stands on the left side of the table aiming to attract customers with their ability to distinguish the technical characteristics of the pro duct There are also in this background brands such as Cool that are oriented more to products of high quality and technically suitable for sport Others (in the area at the seat left) that link instead, quite indistinct between them, to follow the fashion unconstipated at the expense of the more technical characteristics Market PositioningHavaianasHavaianas instead focuses its strategy in being able to exploit the high degree of elaborateness that surfers reserve to this brand and this is the main feature that differentiates it from competitors In the surfing earthly concern Havainas is an object of worship now deeply rooted in the tradition and attractiveness of this sport and it is from this that the brands draws its market power Marketing Goals Create an emotional bond with the brand and its history Provide more popularity to the brand so that potential buyers earth-closet easily associate the brand with various modelsBrand school of thought Extraordinary capabilities that this product has to create a bond between the substance abuser and Brazil, the place of origin of the product and always destination of dreams of Italians Havaianas is a product that can be considered true a long history, a expectant deal of continuity (the characteristics have remained largely unchanged over time) inborn materials and a process that has within it elements almost craft (examples of this are the molds make ? by hand) that make it meaningful and rich of story to tellMarketing Initiatives Havaianas Disco-Bus Twinsbros & Havaianas ledgeman group Website Website At the heart of our proposals for Havaianas there is the transformation of the current website in golf club to create a direct relationship with the consumer and a sense of social status Build a section dedicated to events and parties with a photogallery which shows all connected to the world of Havaianas and itslifestyle Website Party on Havaianas. it The user, in order to take part in various competiti ons, must enroll communicating his e-mail.This entrust throw in the company to create a large agenda of contacts through which it can communicate the dates of events, promotions and news of any kind in order to create a direct line to the most loyal. For people registered, there will be a further advantage will be sent by e-mail invitations for the various parties that will be printed and presented at the transport for a chance to enter for free Testimonial for Havaianas The consumers will place their photos with the more strange use that they can make with their flip-flops.The most uncommon and original will be published on the site, with the possibility to be commented on by all users, and the winning photo will engender the icon for the communication campaign of Havaianas in the following year Twinsbros & Havaianas Surf Team The TwinsBros Factory has its headquarters in Livorno(Italy) and is structured specifically for the production of high quality surfboards The first g oal of the collaboration is to create a set of surfboards and material competition sponsored Havaianas The second one is sponsor a team of surfers who will turn Italy to participate the races of the Italian circuit Twinsbros & Havaianas Surf Team Return in terms of visibility will be published a banner Havaianas. it on the homepage of the site twinsbros. net Will be published a banner of TB & Havaianas surf team on the two main Italian surf portals (surfdome. it & surftolive. com) Will be published articles accompanied by photographs on the same portals above and magazines same Surfer Magazine, SurfUP & SurfNews Strong visibility in the audience present at the competition with the distribution of gadgets Havaianas Disco-Bus The project consists of a disco-bus which during the summer will turn to the most famous locations of the italian summer nightlife (Riccione, Milano Marittima, Porto Cervo, etc. .. ) It will be deprived of the seats and designed with the logo Havaianas in an d outside so as to produce a strong visual impact on the observer The atmosphere will be tipically brazilian with theme-parties, music, cocktails and various kinds of gadgets provided

Appendix A †Questionnaire Essay

Conclusion (300) The current study found that thither are significant differences in terms of both nutrition association and wellness behaviours between normal weight and obese individuals. In particular, they whoop it up much glasses of piddle and engage more frequently in exercise sessions. It has also noted that the obese stem also has more frequent intake of meals crisps sweets, burnt umber or desert sweetie beverages low-pitched calorie drinks instant noodles and deep fried nutriment. They also read labels more frequently and are aware of the recommended intake for various sources.While not all factors have yielded significant differences, the fact that there are differences in some of the factors compared suggest that being aware of proper nutrition and the risks of obesity may be beneficial for Hong Kong residents so that they make take the happy means for preventing these risks. * divert underline your answer where appropriate 1. Please finalise your height, weig ht and gender Height (m) Weight (kg) Gender 2. What is your age group? ? 18 to 23 ? 30 to 35 ? 24 to 29 ? 36 to 40 3. What is your occupation? ? Student ? Housewife/husband?Clerk or officer ? Technical worker ? Other please specify 4. What is your bringing up level? ? Up to primary school ? Up to F. 3 (secondary) ? Up to A-level ? University or above 5. Do you know what is BMI stand for? ? Yes, please arouse it ? No 6. What configurations of diet are rich in fibre? ? Vegetables ? message ? Fish ? No idea 7. What is the recommended periodical intake for fruits and vegetables? ? 3 grammatical constituent a twenty- quad hours ? 7 a day ? 5 assign a day ? No idea 8.Do you know the recommended daily intake for the food group of bread, cereal, rice & noodles? e. g. 1 to 2 servings per day ? Yes ? No If yes, please state it 9. Carbohydrates, protein and fats are the main sources of energy from the diet. Do you know the recommended daily % for each source? e. g. 30% carbohydrates, 40% protein, and 30% fat ? Yes ? No If yes, please state it 10. How many glass of water do you drink everyday? ? Less than 2 or 2 ? 3-4 ? 5-6 ? 7 or above 11.Do you read the nutritional labeling of food that you take daily? ? Yes ? No If yes, do you read all of the food that you eat or only read for a certain food items? ? All ? Read some only 12. Do you consider your health before choosing what to eat? ? Always ? Some generation ? Never 13. What time do you ordinarily have your supper? ? 6 to 7 pm ? 7 to 8 pm ? 8 to 9 pm 14. What time do you unremarkably go to sleep? ? Before 10 pm ? 10- 11 pm ? 11- 12 pm ? After 12 pm For how foresighted? 15. How a great dealtimes do you do exercise? ? Rarely/ Never ? 1 to 2 times a hebdomad ? 3 to 4 times a week ? More than 5 times a weekIf yes, for how long each time? ? 4 times a day 3 to 4 times a day 2 to 3 times a day 3 -4 times a week 1 -2 times a week Rarely/ never E. g. Crisps x Sweets, chocolate or Dessert Sweetie Beverages Low calor ie drinks (e. g. diet coke) arcsecond noodles/ cup noodles Any deep fried food (fried meatball, fried tofu etc) 19.How often did you eat out or order a takeout food/delivery last week? Please cross(x) 1 option under ? 3 times a day ? 2 times a day ? 1 times a day ? More than 5 times a week ? 2 to 5 times a week ? Rarely /Never Is it almost the same every week or just happened in last week? 20. Do you usually eat more food in the restaurant than at radical? ? Yes ? No 21.Do you think food given in restaurants in less healthy than home- made food? ? Yes ? No Why? 22. What kind of restaurant/ cafe do you visit the most? Please inclination of an orbit 3 of them. Starting from the 1st most, 2 and 3. For example 1st McDonalds second Japanese restaurant 3rd Hot pot restaurant 1. 2. 3. 23. How often did you visit the following food service last month? Please cross(x) your option. Everyday Most days 2 to 3 time a week Once a week Rarely/ never e. g. topical anesthetic cuisine x Local cuisine(e. g. Dim sum) Japanese food nimble food (KFC, McDonalds) Dessert shop Other Please specify _________________.24. ar you happy with your weight? ? I am happy with my weight. ? I would standardized to lose weight ? I would like to put on weight.ReferencesKarelis, A. D. , St-Pierre, D. H. , Conus, F, Rabasa-Lhoret, R. , & Poehlman, E. T. , (2004). metabolous and body composition factors in subgroups of obesity what do we know? The ledger of Clinical Endocrinology & Metabolism, 89(6), 25692575. Lau, D. (2006). A pilot study on the attitudes and practice relating to the worry of overweight and obese patients among primary health care professionals in four primary care clinics in Hong Kong.The Hong Kong Practitioner, 28. Lin, B. H. , Guthrie, J. & Frazao, E. (1999). Nutrient contribution of food forth from home. Frazao, E. (eds). Americas eating habits Changes and consequences, 213-242 U. S. Department of Agriculture, Economic Research returns Washington, D. C. Agriculture Information Bulletin No. 750. Obesity and overweight. Retrieved on phratry 30, 2006 from http//www. who. int/dietphysicalactivity/media/en/gsfs_obesity. pdf Obesity Research. (undated). Retrieved on September 20, 2006 from http//www. obesityresearch. org/cgi/reprint/12/6/889. pdf Popkin B. N. , Lu B.International Journal Obesity Related Metabolic Disorder, 28, 282 289. Woo, J, Leung, S. S. F. , Ho, S. C, Lam, T. H, Janus, E. D (1998). Dietary Intake and Practices in Hong Kong Chinese Population J. Epidemiol. Community Health, 52, 631-637. Woo, J. (2000). Diet, nutrition, and health in older China adults. Retrieved on September 30, 2006 from http//www. unsystem. org/SCN/archives/scnnews19/ch17. htm Woo, J. (2000). diet and health issues in the general Hong Kong population. Retrieved on September 20, 2006 from http//www. hkmj. org. hk/hkmj/abstracts/v4n4/383. htm.

Computer Hardware Essay

I. LECTURE OVERVIEWFoundation C one timepts figurer ambitiousw ar, reviews tr destroys and developments in micro calculator, mid browse, and processor electronic calculating machine administrations staple discriminating in cast of partingsation processor trunk concepts and the major faces of technologies make commit of in peripheral subterfuges for expressy reckoner infix, takings, and entrepot. estimator Systems Major types of take aimy reckoner systems be summarized in Figure 13.2. A memorializey reckoner is a system of information affect components that perform input, treat, turnout, fund, and take in manoeuvers. Its hardw be components take on input and turnout winds, a profound rival on unit ( processor), and first and bitary fund devices. The major functions and hardw be in a calculation machine system ar summarized in Figure 13.9 own(prenominal) computing machine Systems Micro electronic estimators be utilize as face-to-face data processors, entanglement data processors, personal digital assistants, technical workstations, and information appliances. Like to the highest degree ready reckoner systems today, personal computers atomic number 18 in corporeald in a conformation of telecommunications interlocks. This typic ally includes local bea profits, invitee/server interlocks, intranets and extranets, and the internet. new(prenominal) ready reckoner Systems Midrange computers ar increasingly employ as tendinous profits servers, and for umpteen multi drug substance abuser transmission line selective information impact and scientific applications. mainframe computer computers be out size of itr and to a commodiouser extent respectable than c withdraw to midsize computers. They argon ordinarily faster, harbor much entrepot capacitance, and basin support more(prenominal) network users and peripheral devices. They argon numbered to handle the information touch nee ds of seriousy grown organizations with high volumes of transaction treat, or with conf apply computational problems. Supercomputers ar a special category of passing mightily central impact unit computer systems excogitateed for vast computational assignments.II. LEARNING OBJECTIVESLearning accusative Identify the major types, trends, and uses of microcomputer, midrange and mainframe computer systems. Outline the major technologies and uses of computer peripherals for input, output, and memory board. Identify and give examples of the components and functions of a computer system. Identify the computer systems and peripherals you would consider or recommend for a handicraft of your choice, and explain the reasons for your selections.III. LECTURE NOTES segmentation 1 estimator Systems End User and Enterprise reckoning inductionAll computers argon systems of input, bear upon, output, computer memory, and maintain components. Technology is evolving at a fast pace, and new-fangled forms of input, output, processing, and entrepot devices continue to enter the market. Analyzing urban center of Richmond and Tim Beaty BuildersWe green goddess learn a lot about innovative pedigree uses of PDAs from this chemise. larn a few proceeding to evidence it, and we will discuss it (See City of Richmond and Tim Beaty Builders in Section IX).TYPES OF COMPUTER remainsS -Figure 13.2There argon near(prenominal) major categories of computer systems with a variety of characteristics and capabilities. Thus, computer systems be typically classified as Mainframe computers Midrange computers personal computersThese categories atomic number 18 attempts to describe the relative figuring position reard by different reason platforms or types of computers therefore, they ar not precise classifications. Some experts predict the merging or disappearance of some(prenominal)(prenominal)(prenominal) computer categories. They feel that galore(postnominal) midrange and mainframe systems project been made obsolete by the power and versatility of client/server networks of microcomputers and servers. Most recently, both(prenominal) application experts progress to predicted that the emergence of network computers and information appliances for applications on the internet and integrated intranets will commute many personal computers, oddly in grownup organisations and in the home computer market.MICROCOMPUTER SYSTEMSMicrocomputers atomic number 18 the smallest notwithstanding nigh important categories of computers systems for disdain people and consumers. They argon as well referred to as personal computers (or PCs). The computing power of current microcomputers exceeds that of the mainframe computers of previous generations at a fraction of their cost. They have become powerful-networked professional workstations for use by end users in business.Microcomputerscategorised by size1. Handheld2. Notebook3. laptop4. Portable5. D esktop6. Floor-standingMicrocomputerscategorised by use1. Home2. personal3. Professional4. Workstation5. Multi-user SystemsMicrocomputerscategorised by special purpose1. Workstation Computers2. net income Servers3. in the flesh(predicate) digital AssistantsWorkstation Computers some microcomputers are powerful workstationcomputers (technical work stations) that support applications with big(a) mathematical computing and graphics dis tomboy enquires much(prenominal) as computeraided run into (CAD) in engineering, or investment and portfolio analysis in the securities industry. Network Servers are usually more powerful microcomputers that co-ordinate telecommunications and resourcesharing in small local sphere networks (LANs), and Internet and intranet bladesites. This is the fastest growing microcomputer application category.Network Computers Network Computers (NCs) are a major new microcomputer category designed primarily for use with the Internet and corporate intranets by clerical workers, operational employees, and knowledge workers with specialised or throttle computing applications.In-between NCs and full-featured PCs are stripped-down PCs known as NetPCs or legacy-free PCs. NetPCs are designed for the Internet and a limited range of applications deep down a company. Examples are Dells Webpc, Compaqs IPaq, HPs e-PC, and eMachines e maven.Network computers (also called thin clients) are low-cost, sealed, networked microcomputers with no or token(prenominal) train record shop. Users of network computers count on primarily on Internet and intranet servers for their in operation(p) system and web browser, Java-enabled application computer software program, and selective information irritate and fund. Main attractions of network computers everywhere full-featured PCs are their low cost to Purchase Upgrade alimony SupportOther benefits to businesses include Ease of software distri saveion and licensing Computing platform standardisati on Reduced end user support requirements amend manageability by dint of centralised management and enterprisewide misrepresent of computer network resources.Information AppliancesThe market is bring home the baconing a number of gadgets and information appliances that offer users the capability to perform enable host of fundamental computational chores. Examples of some information appliances include Personal digital Assistants (PDAs) are designed for cheerful mobile communications and computing. PDAs use touch screens, pen- ground write course credit, or keyboards to protagonist mobile workers fling and receive E-mail, access the Web, and exchange information much(prenominal)(prenominal) as ap vizorments, to-do lists, and sales contacts with their backdrop PCs or web servers. Set-top boxes and photograph recording-game consoles that yoke to home TV sets. These devices enable you to surf the Web or publicise and receive E-mail and watch TV curriculums or play del ineation games at the same time. Wireless PDAs and cellular and PCS phones and wired sound-based appliances that can send and receive E-mail and access the Web.Computer TerminalsComputer terminals are chthoniangoing a major conversion to networked computer devices. For example Dumb terminals are keyboard/ exposure monitor devices with limited processing capabilities, to intelligent terminals, which are modified networked PCs, network computers or former(a)wise microcomputer-powered network devices. Intelligent terminals can perform entropy approach and some information processing tasks free-lancely. Networked terminals which may be Windows terminals that are dependent on network servers for Windows software, processing power, and fund, or Internet terminals, which depend on Internet or intranet website servers for their operating systems and application software. Transaction terminals are a form of intelligent terminal. Uses can be shew in banks retail stores, factories, and other work sites. Examples are ATMs, factory motion recorders, and POS terminals.MIDRANGE COMPUTER SYSTEMSMidrange computers, including minicomputers and high-end network servers, aremulti-user systems that canmanage networks of PCs and terminals. Characteristics of midrange computers include Generally, midrange computers are general-purpose computers that are enceinter and more powerful than near microcomputers but are smaller and less powerful than closely blown-up mainframes. be less to buy, operate, and maintain than mainframe computers. Have become popular as powerful network servers to servicing manage large Internet websites, corporate intranets and extranets, and client/server networks. Electronic commerce and other business uses of the Internet are popular high-end server applications, as are integrated enterprisewide manufacturing, distribution, and monetary applications. info warehouse management, information digging, and online analytical processing are modify to the growth of high-end servers and other midrange systems. First became popular as minicomputers for scientific research, orchestration systems, engineering analysis, and industrial process monitoring and control. Minicomputers could easily handle such uses because these applications are narrow in scope and do not demand the processing versatility of mainframe systems. Serve as industrial process-control and manufacturing graft computers and they play a major role in computeraided manufacturing (CAM). Take the form of powerful technical workstations for computer-aided design (CAD) and other computation and graphics-intensive applications. Are utilise as front-end computers to assist mainframe computers in telecommunications processing and network management. Can function in ordinary operating env compressments (do not need air condition or galvanisingal wiring). Smaller models of minicomputers do not need a staff of specialists to operate them.MIDRANGE COMPUTER APPLI CATIONSServe as industrial process-control and manufacturing plant computers. Play a major role in computer-aided manufacturing (CAM).Serve as powerful technical workstations for computer-aided design (CAD) and other computation and graphics-intensive applicationsServe as front-end computers to assist mainframe computers in telecommunications processing and network management.Midrange Computer as Network Server Electronic commerce and other business uses of the Internet are popular high-end server applications, as are integrated enterprisewide manufacturing, distribution, and financial applications. Other applications, like info warehouse management, entropy mining, and online analytical processing are contributing to the growth of high-end servers and other midrange systems. Serve as powerful network servers to help manage large Internet web sites, corporate Intranets and extranets, and client/server networksMAINF random memoryE COMPUTER SYSTEMSMainframe computers are large, fast , and powerful computer systems. Characteristics of mainframe computers include They are physically larger and more powerful than micros and minis. Can process hundreds of millions of instructions per second (million instructions per second). Have large primary transshipment center capacities. Main store capacitance can range from hundreds of megabytes to many gigabytes of primary storage. Mainframes have slimmed down drastically in the concluding few years, dramatically reducing air-conditioning needs, electronic power consumption, and floor pose requirements, and and then their acquisition and operating costs. Sales of mainframes have increase cod to cost reductions and the increasein applications such as data mining and wareho apply, decision support, and electronic commerce.Mainframe Computer Applications Handle the information processing needs of major corporations and government agencies with many employees and customers. Handle enormous and complex computational proble ms. Used in organisations processing great volumes of transactions. Handle great volumes of complex calculations involved in scientific and engineering analyses and simulations of complex design projects. Serve as superservers for the large client/server networks and high-volume Internet web sites of large companies. Are becoming a popular business-computing platform for data mining and warehousing, and electronic commerce applications.Supercomputer SystemsThe term supercomputer describes a category of extremely powerful computer systems specifically designed for scientific, engineering, and business applications requiring extremely high-speeds for massive numeric computations.Supercomputer Applications Used by government research agencies, large universities, and major corporations. Are used for applications such as global weather forecasting, forces defence systems, computational cosmology and astronomy, microprocessor research and design, large scale data mining, large time-shar ing networks, and so on. Use parallel processing architectures of interconnected microprocessors (which can execute many instructions at the same time in parallel). Can perform arithmetic calculations at speeds of billions of floating- come in operations per second (gigaflops). teraflop (1 trillion floating-point operations per second) supercomputers, which use advanced massively parallelprocessing (MPP) designs of thousands of interconnected microprocessors, are becoming available. Purchase price for large supercomputers are in the $5 million to $50 million range.Mini-supercomputersThe use of rhombohedral multiprocessing (SMP) and distributed shared retrospect (DSM) designs of smaller numbers of interconnected microprocessors has spawned a breed of mini-supercomputer with prices that start in the hundreds of thousands of dollars.TECHNICAL NOTE THE COMPUTER SYSTEM CONCEPTS Figure 13.9As a business professional, you do not need a detailed technical knowledge of computers. However , you do need to ascertain some basic facts and concepts about computer systems. This should help you be an informed and amentiferous user of computer system resources.A computer is a system, an co-ordinated combination of components that perform the basic system functions of input, processing, output, storage, and control, and so providing end users with a powerful information-processing tool. Understanding the computer as a computer system is vital to the effective use and management of computers. A computer is a system of hardware devices organised according to the following system functions Input. Examples of some input devices of a computer system include1. Keyboards2. Touch natural coverings3. depress Pens4. Electronic Mice4. opthalmic Scanners5. Voice InputThey convert data into electronic machine-readable form for enjoin entry or by a telecommunications network into a computer system.Processing. The central processing unit (CPU) is the main processing component of a computer system. (In microcomputers, it is the main microprocessor). matchless of the CPUs major components is the arithmetic-logic unit (ALU) that performs the arithmetic and logic functions required in computer processing. Components of the CPU include1. Control Unit 2. Arithmetic-Logic Unit 3. primary winding shop UnitOutput. Convert electronic information produced by the computer system into human-intelligible form for presentation to end-users.Examples of output devices include1. television set Display Units 2. sound Response Units 3. Printers computer storage. The storage function of a computer system is used to store data and program instructions postulate for processing. retentiveness devices include1. Primary stock Unit (main repositing)2. Secondary terminus gubbinss ( magnetised magnetized dish antenna and register units, ocular plows)Control. The control unit of a CPU interprets computer program instructions and transmits directions to the other compone nts of the computer system.Computer Processing SpeedsOperating speeds of computers are measured in a number of ways. For example Milliseconds Thousands of a second.Microseconds Millionths of a second.Nanoseconds Billionth of a secondPicosecond Trillionth of a secondOther terminology used includesTeraflop used by some supercomputersMIPS Million instructions per secondMegahertz (MHz) Millions of cycles per secondGigahertz (GHz) Billions of cycles per secondClock Speed used to rate microprocessors by the speed of their measure circuits and internal clock.Section II Computer Peripherals Input, Output, and Storage TechnologiesINTRODUCTIONA computer is just a high-powered processing box without peripherals. Your personal computing needs will dictate the components you choose for our cave inicular computing needs. Analyzing United Technologies and Eastman KodakWe can learn a lot about the business appreciate of consolidating computer operations and systems from this case. Take a few minutes to read it, and we will discuss it (See United Technologies and Eastman Kodak in Section IX).PERIPHERALSPeripherals are the generic name for all input, output, and secondary coil storage devices that are array of a computer system. Peripherals depend on direct connections or telecommunications cogitate to the central processing unit of acomputer system. Thus, all peripherals are online devices, that is, separate from, but can be electronically connected to and controlled by, a CPU. This is the opposite of off-line devices, which are separate from and not under the control of the CPU.INPUT TECHNOLOGYThere has been a major trend toward the increased use of input technologies that deliver a more indispensable user interface for computer users. more(prenominal) and more data and commands are cosmos entered directly and easily into computer systems by means of pointing devices like electronic mice and touch pads, and technologies like ocular examine, handwriting recognition, and voice recognition.POINTING DEVICESKeyboards are excuse the around widely used devices for entering data and text into computer systems. However, pointing devices are a better alternative for issuing commands, making choices, and responding to prompts screeninged on your video screen. They work with your operating systems graphical user interface (GUI), which presents you with icons, menus, windows, buttons, nix, and so on, for your selection. Examples of pointing devices include Electronic Mouse A device used to fall upon the cursor on the screen, as well as to young commands and make icon and menu selections. Trackball A device used to move the cursor on the display screen.Pointing stay on A small spangly device, sometimes likened to the eraser head of a pencil. The cursor moves in the direction of the insistence you place on the track point. Touchpad A small rectangular touch-sensitive go up usually placed below the keyboard. The cursor moves in th e direction your finger moves on the pad.Touch Screens A device that accepts data input by the placement of a finger on or close to the cathode-ray tube screen.PEN-BASED COMPUTINGPen-based computing technologies are world used in many hold computers and personal digital assistants. These small PCs and PDAs contain fast processors and software that recognises and digitises handwriting, hand printing, and hand drawing. They have a pressure-sensitive layer like a graphics pad under their slatelike liquid crystal display (LCD) screen.A variety of penlike devices are availableDigitizer Pen A photoelectronic device that can be used as a pointing device, or used to draw or write on a pressure-sensitive surface of a graphics tablet.Graphics Tablet A device that allows an end user to draw or write on a pressure-sensitive tablet and has their handwriting or graphics digitised by the computer and accepted as input. delivery RECOGNITION SYSTEMSSpeech recognition and voice response (in the ir infancy) promise to be the easiest method of data entry, word processing, and conversational computing, since dustup is the easiest, most natural means of human communication.Speech recognition systems analyse and classify address or vocal tract patterns and convert them into digital codes for entry into a computer system. Early voice recognition products used discrete actors line recognition, where you had to pause between distributively spoken word. New continuous speech recognition (CSR) software recognises controlled, conversationally paced speech. Examples of continuous speech recognition software include NaturallySpeaking by Dragon Systems ViaVoice by IBM VoiceXpress by Lernout & Hauspie FreeSpeech by PhilipsAreas where speech recognition systems are used include Manufacturers use it for inspection, inventory, and quality control Airlines and parcel delivery companies use it for voice-directed sorting of baggage and parcels Voice touch off GPS systems are being used in advanced car design Physicians use it to enter and printout prescriptions Gemmologists use it to free up their hands when inspecting and place precious stones Handicapped mortals use voice-enabled software to operate their computers, e-mail, and surf the solid ground Wide Web.Speaker-independent voice recognition systems allow a computer to understand a few words from a voice it has never comprehend before. They enable computers to respond to verbal and touch-tone input over the telephone.Examples include Computerized telephone call switching Telemarketing surveys Bank pay-by-phone bill-paying service Stock quotations services University registration systems Customer credit and account balance inquiriesOPTICAL examineOptical scanning devices read text or graphics and convert them into digital input for a computer. Optical scanning enables the direct entry of data from source documents into a computer system.Popular uses of optical scanning include Scanning varlets of text an d graphics into your computer for desktop publishing and web publishing applications. Scan documents into your system and organize them into folders as part of a document management library system for easy cite or retrieval.There are many types of optical scanners, but they all employ photoelectric devices to scan the characters being read. Reflected light patterns of thedata are converted into electronic impulses that are then accepted as input into the computer system.Optical scanning engine room known as optical character recognition (OCR) can read special-purpose characters and codes. OCR scanners are used to read characters and codes onMerchandise tagsProduct labelsCredit poster receipts inferior billsInsurance premiumsAirline ticketsSort mailScore testsProcess business and government formsDevices such as handheld optical scanning wands are used to read OCR coding on merchandise tags and other media. more business applications involve reading bar code, a code that utilise s bars to represent characters. One parking area example is the Universal Produce engrave (UPC) bar coding that you see on packages of food items and many other products.OTHER INPUT TECHNOLOGIES magnetised stripe technology is a familiar form of data entry that helps computers read credit cards. The dark charismatic stripe on the back of such cards is the same iron oxide coating as on magnetised immortalise. Smart cards that establish a microprocessor dapple and several(prenominal) kilobytes of memory into debit entry, credit, and other cards are popular in Europe, and becoming available in the United States. Digital cameras and digital video cameras enable you to shoot, store, and download still photos or full motion video with audio into your PC. magnetised ink character recognition (MICR) is machine recognition of characters printed with magnetised ink. Primarily used for check processing by the banking industry.OUTPUT TECHNOLOGIESComputers provide information in a vari ety of forms. Video displays and printed documents have been, and still are, the most common forms of output from computer systems. But other natural and attractive output technologies such as voice response systems and multimedia output are increasingly found along with video displays in business applications.VIDEO OUTPUTVideo displays are the most common type of computer output. Most desktop computers rely on video monitors that use cathode ray tube (CRT) technology. commonly, the pellucidity of the video display depends on the type of video monitor you use and the graphics circuit board installed in your computer. A high-resolution, flicker-free monitor is especially important if you spend a lot of time viewing multimedia on CDs or the Web, or complex graphical displays of many software packages.The biggest use of liquid crystal displays (LCDs) is to provide a opthalmic display capability for portable microcomputers and PDAs. LCD displays need significantly less electric curre nt and provide a thin, flat display.Advances in technology such as active matrix and dual scan capabilities have modify the color and clarity of LCD displays.PRINTED OUTPUTAfter video displays, printed output is the most common form of output displays. Most personal computer systems rely on inkjet or laser printers to produce permanent (hard copy) output in high-quality printed form. Printed output is still a common form of business communications, and is frequently required for legal documentation. Inkjet printers Spray ink onto a page one line at a time. They are popular, low-cost printers for microcomputer systems. They are quiet, produce several pages per minute of high-quality output, and can print both black-and-white and high-quality colour graphics.Laser Printers Use an electrostatic process analogous to a photocopying machine to produce many pages per minute of high-quality black-and-white output. to a greater extent expensive colour laser printers and multifunction in kjet and laser models that print, fax, scan, and copy are other popular choices for business offices. retentiveness TRADE-OFFSselective information and information need to be stored after input, during processing, and before output. Computer-based information systems rely primarily on the memory circuits and secondary storage devices of computer systems to accomplish the storage function.Major trends in primary and secondary storage methods Progress in very-large scale consolidation (VLSI), which packs millions of memory circuit elements on small semiconductor unit device memory chips, are responsible for continuing increases in the main-memory capacity of computers. Secondary storage capacities are also expected to escalate into the billions and trillions of characters, due primarily to the use of opticalmedia.Storage Trade-offs Speed, capacity, and cost relationships. Note the cost/speed/capacity trade-offs as one moves from semiconductor memories to magnetic media, such as mag netic discuss and tapes, to optical magnetic discs. High-speed storage media cost more per byte and provide lower capacities. giant capacity storage media cost less per byte but are lazy semiconductor unit memories are used principally for primary storage, though they are sometimes used as high-speed secondary storage devices. magnetized phonograph recording and tape and optical disk devices are used as secondary storage devices to greatly enlarge the storage capacity of computer systems. Most primary storage circuits use RAM (random access memory) chips, which lose their contents when electrical power is interrupted Secondary storage devices provide a more permanent type of storage media for storage of data and programs.Computer Storage Fundamentals Figure 13.20Data is processed and stored in a computer system through the strawman or absence of electronic or magnetic signals in the computers circuitry in the media it uses. This is called a two-state or binary star represen tation of data, since the computer and media can exhibit sole(prenominal) two possible states or conditions ON (1) or OFF (0).Computer storage elements Bit is the smallest element of data, (binary digit) which can have a value of zero or one. The capacity ofmemory chips is usually expressed in terms of bits.Byte is the basic grouping of bits that the computer operates as a whiz unit. It typically consists of 8 bits and is used to represent one character of data in most computer coding schemes (e.g. 8 bits = 1 byte). The capacityof a computers memory and secondary storage devices is usually expressed in terms of bytes. ASCII (American Standard Code for Information Interchange)EBCDIC (Extended binary star Coded Decimal Interchange Code) Pronounced EB SEE DICKStorage capacities are frequently measured inKilobyte= 1,000 bytesMegabyte= 1,000,000 bytesGigabyte= 1,000,000,000 bytes tebibyte= 1,000,000,000,000 bytesPetabyte= 1,000,000,000,000,000 bytesExabyte= 1,000,000,000,000,000,00 0 bytesZettabyte= 1,000,000,000,000,000,000,000 bytesYottabyte= 1,000,000,000,000,000,000,000,000 bytesDirect and Sequential Access Direct Access Primary storage media such as semiconductor memory chips are called direct access or random access memories (RAM). Magnetic disk devices are frequently called direct access storage devices (DASDs).The terms direct access and random access describe the same concept. They mean that an element of data or instructions can be directly stored and retrieved by selecting and using any of the locations on the storage media. They also mean that each storage position (1) has a unique address and (2) can be singly accessed in approximately the same length of time without having to search through other storage positions.Sequential Access successive access storage media such as magnetic tape do not have unique storage addresses that can be directly addressed. Instead, data moldiness be stored and retrieved using a sequential or serial process. Data are recorded one after another in a predetermined sequence on a storage moderate. Locating an individual item of data requires searching much of the recorded data on the tape until the desired item is located.SEMICONDUCTOR MEMORYThe primary storage (main memory) on most modern computers consists of microelectronic semiconductor memory circuits. Plug-in memory circuit boards containing 32 megabytes or more of memory chips can be added to your PC to increase its memory capacity. Specialized memory can help improve your computers performance. Examples include foreign cache memory of 512 kilobytes to help your microprocessor work faster Video graphics accelerator cards with 16 megabytes of RAM are used for faster and clearer video performance removable credit-card-size and smaller flash memory RAM cards provide several megabytes of erasable direct access storage for PDAs or hand-held PCs.Some of the major attractions of semiconductor memory are Small size Fast speed Shock and tempera ture resistanceOne major impairment of most semiconductor memory is Volatility Uninterrupted electric power must be supplied or the contents of memory will be lost (except withread exclusively memory, which is permanent).There are two basic types of semiconductor memory Random Access remembering (RAM) these memory chips are the most widely used primary storage medium. Each memory position can be both read and written, so it is also called read/write memory. This is a volatile memory.Read Only Memory ( read-only storage) Non-volatile random access memory chips are used for permanent storage. read-only memory can be read but not erased or overwritten. instructions and programs in primary storage can be permanently burned into the storage cells during manufacturing. This permanent software is also called firmware. Variations include mall (programmable read only memory) and EPROM (erasable programmable read only memory), which can be permanently or temporarily programmed after manufacture.MAGNETIC DISK STORAGEThese are the most common forms of secondary storage for modern computer systems. Thats because they provide fast access and high storage capacities at a reasonable cost. Characteristics of magnetic disks magnetic disc vexs contain metal disks that are coated on both sides with an iron oxide recording material. Several disks are mounted together on a vertical shaft, which typically rotates the disks are speeds of 3,600 to 7,600 revolutions per minute (rpm) Access arms between the slightly separated disks to read and write data on concentric, circular tracks position electromagnetic read/write heads. Data are recorded on tracks in the form of piffling magnetized drifter to form the binary digits of common computer codes. Thousands of bytes can be recorded on each track, and there are several hundred data tracks on each disk surface, which provides you with billions of storage positions for software and data. Types of Magnetic magnetic disksThere are several types of magnetic disk arrangements, including disk cartridges as well as fixed disk units. Removable disk devices are popular because they are transportable and can be used to store backup copies of your data off-line for convenience and security. diskette dish aerials, or magnetic disks, consist of polyester film disks covered with an iron oxide compound. A single disk is mounted and rotates freely inside a tutelary flexible or hard plastic jacket, which has access openings to accommodate the read/write head of a disk drive unit. The 3-1/2-inch floppy disk, with capacities of 1.44 megabytes, is the most widely used version, with a newer Superdisk technology offering 120 megabytes of storage. Hard Disk Drives combine magnetic disks, access arms, and read/write heads into a sealed module. This allows higher speeds, greater data-recording densities,and closer tolerances within a sealed, more stable environment. Fixed or removable disk cartridge versions are available. Ca pacities of hard drives range from several hundred megabytes to many gigabytes of storage.RAID StorageDisk arrays of interconnected microcomputer hard disk drives have replaced large-capacity mainframe disk drives to provide many gigabytes of online storage. Known as RAID (redundant arrays of independent disks), they combine from 6 to more than 100 small hard disk drives and their control microprocessors into a single unit. Advantages of RAID disks include Provide large capacities with high access speeds since data is accessed in parallel over eighter from Decatur-fold paths from many disks. Provide fault tolerant capability, since their redundant design offers aggregate copies of data on several disks. If one disk fails, data can be recovered from backup copies automatically stored on other disks. Storage area networks (SANs) are high-speed fibre channel local area networks that can interconnect many RAID units and share their combined capacity through network servers for many u sers.MAGNETIC TAPE STORAGEMagnetic Tape is still being used as a secondary storage medium in business applications. The read/write heads of magnetic tape drives record data in the form of magnetised floater on the iron oxide coating of the plastic tape. Magnetic tape devices include tape reels and cartridges in mainframes and midrange systems, and small cassettes or cartridges for PCs.These devices serve as poky, but lower cost, storage to supplement magnetic disks to meet massive data warehouse and other business storage requirements. Other major applications for magnetic tape include long-term archival storage and backup storage for PCs and other systems.OPTICAL DISK STORAGEOptical disk storage involves technology, which is based on using a laser toread tiny spots on a plastic disk. The disks are currently sure-footed of storing billions of characters of information. load down disc read-only memory A common type of optical disk used on microcomputers. They are used for read on ly storage. Storage is over 600 megabytes per disk. This is homogeneous to over 400 1.44-megabyte floppy disks or 300,000 double-spaced pages of text. Data are recorded as microscopic pits in a curlicue track, and are read using a laser device.Limitation save data cannot be erasedCD-R ( covenant disk recordable) is another optical disk technology. It enables computers with CD-R disk drive units to record their own data once on a CD, and then be able to read the data indefinitely. Limitation Recorded data cannot be erasedCD-RW (CD-rewritable) optical disk systems have now become available which record and erase data by using a laser to heat a microscopic point on the disks surface. In CD-RW versions using magneto-optical technology, a magnetic coil changes the spots reflective properties from one direction to another, thus recording a binary one to zero. A laser device can then read the binary codes on the disk by sensing the direction of reflected light. videodisk (Digital Vid eo Disk or Digital Versatile Disk) can hold from 3.0 to 8.5 gigabytes of multimedia data on each side of a bundle disk. The large capacities and high- quality images and sound of videodisk technology are expected to eventually replace CD-ROM and CD-RW technologies for data storage, andpromise to accelerate the use of DVD drives for multimedia products that can be used in both computers and home entertainment systems. DVD-ROM is beginning to replace magnetic tape videocassettes for movies and other multimedia products. DVD RAM is being used for backup and archival storage data and multimedia files. traffic ApplicationsOne of the major uses of optical disks in mainframe and midrange systems is in image processing, where longterm archival storage of historical files of document images must be maintained. Mainframe and midrange computer versions of optical disks use 12-inch plastic disks with capacities of several gigabytes, with up to 20 disks held in jukebox drive units. WORM (Wri te Once, Read Many) versions of optical disks are used to store data on the disk. Although data can only be stored once, it can be read an infinite number of times.One of the major business uses of CD-ROM disks for personal computers is to provide a publishing medium for fast access to reference materials in a convenient, compact form. These include Catalogs Directories ManualsPeriodical abstractsPart listingsStatistical databases of business activity and stinting activity Interactive multimedia applications in business, education, and entertainment usingCD-ROM and DVD disks.Optical disks have become a popular storage medium for image processing and multimedia business applications and they appear to be a promising alternative to magnetic disks and tape for very large mass storage capabilities for enterprise computing systems. However, rewritable optical technologies are still being perfected. Also, most optical disk devices are significantly slower and more expensive (per byte of s torage) than magnetic disk devices. So optical disk systems are not expected to displace magnetic disk technology in the near future for most business applications.IV. KEY name AND CONCEPTS DEFINEDBinary RepresentationPertaining to the presence or absence of electronic or magnetic signals in the computers circuitry or in the media it uses. There are only two possible states or conditions presence or absence. Central Processing Unit (CPU)The unit of a computer system that includes the circuits that controls the interpretation and execution of instructions. In many computer systems, the CPU includes the arithmetic-logic unit, the control unit, and primary storage unit.Computer SystemComputer hardware as a system of input, processing, output, storage, and control components. Thus a computer system consists of input and output devices, primary and secondary storage devices, the central processing unit, the control unit within the CPU, and other peripheral devices.Computer TerminalAny input/output device connected by telecommunications links to a computer.Digital CamerasDigital still cameras and digital video cameras enable you to shoot, store, and download still photos or full-motion video with audio in your PC.Direct AccessA method of storage where each storage position has a unique address and can be severally accessed in approximately the same period of time without having to search through other storage positions. Information ApplianceDevices for consumers to access the Internet.Laptop ComputerA small portable PC.Liquid Crystal Displays (LCD)Electronic visual displays that form characters by applying an electrical charge to selected silicon crystals.Magnetic Disk StorageData storage technology that uses magnetised spots on metal or plastic disks. Magnetic Disk Storage floppy disk DiskSmall phonograph record enclosed in a protective envelope. It is a widely used form of magnetic disk media that provides a direct access storage capability for microcomputer systems. Magnetic Disk Storage Hard DiskSecondary storage medium generally nonremovable disks made out of metal and covered with a magneticrecording surface. It holds data in the form of magnetised spots.Magnetic Disk Storage RAIDRedundant array of independent disks. Magnetic disk units that house many interconnected microcomputer hard disk drives, thus providing large, fault tolerant storage capacities. Magnetic Ink Character erudition (MICR)The machine recognition of characters printed with magnetic ink. Primarily used for check processing by the banking industry.Magnetic StripeA magnetic stripe card is a plastic wallet-size card with a strip of magnetic tape on one surface widely used for credit/debit cards.Magnetic TapeA plastic tape with a magnetic surface on which data can be stored by selective magnetisation of portions of the surface.Mainframe ComputerA larger-size computer system, typically with a separate central processing unit, as distinguished from microcomputer and minicomputer systems.MicrocomputerA very small computer, ranging in size from a Computer on a chip to a small typewriter-size unit. MicroprocessorA semiconductor chip with circuitry for processing data.Midrange ComputerLarger and more powerful than most microcomputers but are smaller and less powerful than most large mainframe computer systems.MinicomputerA small electronic general-purpose computer.Network ComputerA new category of microcomputer designed mainly for use with the Internet and Intranets on tasks requiring limited or specialised applications and no or minimal disk storage. Network ServerA type of midrange computer used to co-ordinate telecommunications and resource sharing and manages large web sites, Intranets, extranets, and client/server networks.Network TerminalA terminal that depends on network servers for its software and processing power. Off-linePertaining to equipment or devices not under control of the central processing unit. OnlinePertaining to equipment or devices under control of the central processing unit. Optical Character Recognition (OCR)The machine identification of printed characters through the use of light-sensitive devices. Optical Disk StorageTechnology based on using a laser to read tiny spots on a plastic disk. The disks are currently capable of storing billions of characters of information.Optical Disk Storage CD-ROMAn optical disk technology for microcomputers featuring compact disks with a storage capacity of over 500 megabytes.Optical Disk Storage CD-RCompact disk recordable (CD-R) enables computers with CD-R disk drive units to record their own data once on a CD, than be able to read the data indefinitely.Optical Disk Storage CD-RWCompact disk rewritable (CD-RW) enables computers with CD-RW disk drive units to record and erase data by using a laser to heat a microscopic point on the disks surface. Optical Disk Storage DVDDigital video disk or digital versatile disk (DVD) enables computers with DVD disk drive uni ts to hold from 3.0 to 8.5 gigabytes of multimedia data on each side of a compact disk. Optical Disk Storage WORM DiskOptical disk that allows users to write once, read many times.Optical ScanningUsing a device (scanner) that scans characters or images and generates their digital representations. Pen-Based ComputingTablet-style microcomputers that recognise hand-writing and hand-drawing done by a pen-shaped device on their pressure sensitive display screens.Peripheral DevicesIn a computer system, any unit of equipment, distinct from the central processing unit, that provides the system with input, output, or storage capabilities.Personal Digital AssistantHandheld microcomputer devices, which are designed for convenient mobile communications and computing. Pointing DevicesDevices, which allow end users to young commands or make choices by moving a cursor on the display, screen. Pointing Device Electronic MouseA small device that is electronically connected to a computer and is mov ed by hand on a flat surface in order to move the cursor on a video screen in the same direction. Buttons on the mouse allow users to issue commands and makeresponses or selections.Pointing Device Pointing StickA small buttonlike device sometimes likened to the eraser head of a pencil. The cursor moves in the direction of the pressure you place on the track point.Pointing Device TouchpadIs a small rectangular touch-sensitive surface usually placed below the keyboard. The cursor moves in the direction your finger moves on the pad.Pointing Device TrackballA roller device set in a case used to move the cursor on a computers display screen. Primary StorageThe main (or internal) memory of a computer. Usually in the form of semiconductor storage. PrintersDevices that produce hard copy output such as paper documents or reports. Secondary StorageExternal or auxiliary storage device that supplements the primary storage of a computer.Semiconductor MemoryMicroelectronic storage circuitry et ched on tiny chips of silicon or other semiconducting material.Semiconductor Memory RAMAlso known as main memory or primary storage type of memory that temporarily holds data and instructions needed shortly by the CPU. RAM is a volatile type of storage. Semiconductor Memory ROMAlso known as firmware a memory chip that permanently stores instructions and data that are programmed during the chips manufacture. Three variations on the ROM chip are PROM, EPROM, and EEPROM. ROM is a nonvolatile form of storage. Sequential AccessA sequential method of storing and retrieving data from a file.Smart CardsCards such as debit and credit cards, which have an embedded microprocessorchip and several kilobytes of memory.Speech RecognitionDirect conversion of spoken data into electronic form suitable for entry into a computer system. Promises to be the easiest, most natural way to communicate with computers.Storage might ElementsUnits used for storage capacity and data bits, bytes, kilobytes (KB) , megabytes (MB), gigabytes (GB), terabytes (TB).Storage force Elements BitA compaction of binary digit. It can have the value of either 0 or1. Storage Capacity Elements ByteA sequence of adjacent binary digits operated on as a unit and usually shorter than a computer word. In many computer systems, a byte is a grouping of eight bits that can represent one alphabetic or special character or can be packed with two decimal digits.Storage Capacity Elements Kilobyte (K or KB)When referring to computer storage capacity it is equivalent to 2 to the 10th power, or 1,014 in decimal notation.Storage Capacity Elements Megabyte (MB)One million bytes. More accurately, 2 to the 20th power, 1,048,576 in decimal notation.Storage Capacity Elements Gigabyte (GB)One billion bytes. More accurately, 2 to the 30th power, or 1,073,741,824 in decimal notation.Storage Capacity Elements Terabyte (TB)One trillion bytes. More accurately, 2 to the 40th power, or 1,009,511,627,776 in decimal notation.St orage Media Trade-offsThe trade-offs in cost, speed, and capacity of various storage media.SupercomputerA special category of large computer systems that are the most powerful available. They are designed to solve massive computational problems. time ElementsUnits used for measuring processing speeds milliseconds, microseconds, nanoseconds, and picoseconds.Time Elements MillisecondA 1000th of a second.Time Elements MicrosecondA millionth of a second.Time Elements NanosecondOne billionth of a second.Time Elements PicosecondOne trillionth of a second.Touch-Sensitive ScreenAn input device that accepts data input by the placement of a finger on or close to the CRT screen.Transaction TerminalsTerminals used in banks, retail stores, factories, and other work sites that are used to overtake transaction data at their point of origin. Examples are point-of-sale (POS) terminals and automated teller machines (ATMs).Video OutputVideo displays are the most common type of computer output.V olatilityMemory (such as electronic semiconductor memory) that loses its contents when electrical power is interrupted. WandA handheld optical character recognition device used for data entry by many transaction terminals. WorkstationA computer terminal or micro- or minicomputer system designed to support the work of one person. Also, a highpowered computer to support the work of professionals in engineering, science, and other areas that require extensive computing power and graphics capabilities.V. DISCUSSION QUESTIONSDo you agree with the statement The network is the computer?What trends are occurring in the development and use of the major types of computer systems?Do you think that network computers (NCs) will replace personal computers (PCs) in business applications?Are networks of PCs and servers making mainframe computers obsolete?Whattrends are occurring in the development and use of peripheral devices? Why are those trends occurring?When would you recommend the use of each of the followingNetwork computersNetPCsNetwork terminalsInformation appliances in business applicationsWhat processor, memory, magnetic disk storage, and video display capabilities would you require for a personal computer that you would use for business purposes?What other peripheral devices and capabilities would you want to have for your business PC?

Motaba Virus – Immune System and Operation Clean Sweep

The mercenary camp was in the Motaba River V all(prenominal)ey of congou tea was bombed to stop the computer computer computer virus from spreadheading. 2. No I would exact removed all the great deal and disinfected all of them so the virus would stay in the set and nobody would die. 3. Sam Daniels and his crew were sent out to the Motaba Valley because at that place was a level 4 virus. 4. The conditions in the Motaba valley were sad, smoky, poor and in that respect were dead people everywhere. 5. The symptoms of the mystery disease at Motaba Valley were tumefy everywhere, sever headaches and bleeding from every orifice. 6.No the virus that caused the mystery disease at Motaba Valley was not airborne. 7. A. The tribesmans explanation of why the disease was change the tribe was because it was the gods punishment for cutting down the rain forest. B. No I founding fathert think the explanation makes any sense because obtain nature couldnt be happy with the loss of the plan ts and forest. 8. They wore thick set cases and multiple airlocks, ultra violet light rooms and workers must be intensely trained. 9. The virus got to the U. S. by the monkey that Jimbo traveled with from the forest. 11.The electron microscope shows slightly the Motaba virus in Kidney kiosks, and it showed it was invaded, multiplied and defeated the cells. 12. Jimbo is the owner of the infected monkey, and the monkey with the virus kills many people. 13. Rudy is the store owner of the animal store, and she is around these animals all the time. 14. Robby try to baring out if Jimbo had any contact with animals or how he got ghastly before he died. 15. A. Jimbo got infected by the virus by a monkey spitting on his mouth. B. Rudy got infected by the monkey loot him. c. Jimbos girlfriend Alice got infected by kissing Jimbo. D.Henry got infected by ocellus splattering on him. E. People at the movie theatre got infected by cosmos coughed on by someone with virus. F. Robby got i nfected by being stabbing herself with the needle. G. Casey got infected by taking his suit in an infected area. 16. A. The Motaba virus mutated because it became airborne. B. The Motba virus was so dicey because it get airborne made it a dish out easier to spread a lot faster. 17. A They forced the people to stay in town and they couldnt leave their houses. B. Family members had to endure that they will eventually die because of the spread of the virus, the screwball ad to be tested and would most likely die. 18. transaction wanton sweep was the bomb that is powerful that not nuclear and is dropped on the California area, killing the disease and virus. 19. Many government officials thought it was demand because the virus wouldnt spread and kill millions. 20. Yes I think it is welcome to kill a few lives to save the human population. Sometimes you wipe out to take desperate measures when theres a deadly virus going around. It would be better to take a few lives than kill the building block human population.It makes sense to kill the people with the virus (because there were few) and save the rest of the population. They could permanently kill off the virus by killing the people with it and saving other people form getting it. I think it would be necessary because to save a whole population would be essential over saving a few people. 21. I think that if there was a positive and known etymon that would help the cause by sacrificing the animals, then it would be necessary so not so many people would die. 22. Danielles prevented the success of Operation Clean Sweep by flying there airplane just in front so they couldnt bomb the city.And by relation back them they found the mend. 23A. They determined the identity of the virus by drawing blood from an infected person. 23B. They determined the cause of the disease by analyzing blood and set it under a microscope and they found tons of ebola viruses in the blood. 23C. They tracked the spread of the virus by keeping track of who had it, how they got it, when and where. 24A. Finding the military of the virus was critical and finding the anti-serum because they had to create the anti-serum from the monkeys blood. 24B.Danielles was so intent on capturing the monkey in California because thats how they would find the cure for the virus, since the monkey was indeed the virus carrier. 25A. A host cell is a living cell in which a virus reproduces. A primary host or definitive host is a host in which the parasite reaches maturity and, if possible , reproduces 25B. The monkey could befuddle been referred to as virus carrier or infected living organism. 26. After capturing the monkey, Daniells and his team up were able to find the cure to the virus and vaccine. 27. They used that room because they did not want the virus to spread anymore. 8. A. Antiserum is blood serum containing polyclonal antibodies. B. Antiserum is used to pass off on passive immunity to many diseases. C. Passive antibody transfusion from a previous human survivor is the only effective treatment for Ebola infection. D. An antigen is a toxin or other foreign substance that induces an insubordinate response in the body, esp. the production of antibodies. E. Antibodies in the antiserum bind the infectious agent or antigen. The resistant system then recognizes the antibody and the antigen and antibody work together to fight off viruses in repellent systems. F.Antibodies in the antiserum bind the infectious agent or antigen. The immune system then recognizes foreign agents bound to antibodies and triggers a more half-hardy immune response. The use of antiserum is particularly effective against pathogens which are capable of evading the immune system in the unstimulated state barely which are not plenteous enough to evade the stimulated immune system. The existence of antibodies to the agent thence depends on an sign lucky survivor whose immune system by chance discovered a counteragent to the pathogen, or a host species which carries the virus but does not suffer from its effects.Further stocks of antiserum can then be produced from the initial donor or from a donor organism that is inoculated with the pathogen and cured by some stock of preexisting antiserum. G. They gave a lot the monkey and they wouldnt beget been able to find a cure that works that fast and be distributing it out to everyone to save currently sick people. It would have interpreted at least a month to find a cure and those people that were in the hospital would have died and not have been protected in real life. H.They gave a lot the monkey and they wouldnt have been able to find a cure that works that fast and be distributing it out to everyone to save currently sick people. It would have taken at least a month to find a cure and those people that were in the hospital would have died and not have been saved in real life. They make the fulfil of the antiserum look like an easy and fats process when really it takes months. It is a difficult task that takes an extremely long time. Its not likely that they would find a cure in both days and not logical.They couldnt pass on the cure that chop-chop to save the people that were currently in he hospital. They would have had to do many tests t find the cure to the virus it would not have taken just two days. 29. I thought the movie was good, but parts were not realistic. It showed how dangerous ebola really was and how fast it could spread. The government would believably take desperate measure to save the whole population. Ebola spreads so apace and kills so fast. The movie was a good representation of ebola, how it spreads and how quickly and dangerous it is. 30. A. Yes viruses kill and they scare man and are deadly and fast moving.B. Everyone was so fearful and hopeless that if It happened today everyone would freak out and live in fear. C. Its significant because man doesnt have all fears but most would have a fear of dea dly virus because its unknown and unseen, D. I think that man will ultimately obtain because there are so man doctors and scientist searching for viruses. That if an outbreak happened they would have a cure so fast with all the engineering being created. A virus is a deadly, killer but I dont see an outbreak in the future because of all the technology and there hasnt been an incident for decades.

Filtration & Centrifugation

FILTRATION Filtration whitethorn be specify as a process of disengagement of hales from a fluent by deterio enume consec evaluateing the kindred through with(predicate) and through a poriferous average that retains the impregnables, but al let looses the fluid to pass through. The suspension to be sink ined is known as slurry. The porous sensitive utilize to retain the solids is known as puree mediocre. The accumulated solids on the drop be referred to as riddle bar, plot of ground the clear fluent passing through the slobber is filt lay stunned. When solids ar int magnetic poleuce in a actually conf applyd concentration i. e. , non colossal 1. 0% w/v, the process of its separation from wateryity is called clarification. butt on of filtration The filtration operation is shown below in the figure * The cogitates of the crystallize medium ar bantamer than the sizing of the activateicles to be sepa tempod. * click medium (for eg gain vigor newsp rint or muslin textile) is placed on a support (a sieve). * When slurry (feed) is passed over the dribble medium, the fluid commingles through the sieve medium by virtue of a military press differential across the tense up. * Gravity is playing on the eloquent column. Therefore, solids ar trapped on the issue of the riddle medium numeral 1 filtration Once the preliminary layer of particles is deposited, further filtration is brought about wherein the leach medium serves only as a support. * The penetrate will treat efficiently only after an initial deposit. * After a peculiar(a) point of time, the opponent offered by the filter legal comm building blocky is broad(prenominal) that closely filtration is s bakshishped. For this reason, a positive drive is applied on the filter measure (upstream) or negative pressure (suction) is applied below the filter medium ( smoothenstream). Factors affecting the account of filtrationThe tread of filtration which depends on various(a) factors bear be written as set out of filtration = Area of filter X compel oddment muggyness X Resistance of saloon and filter The rate of filtration depends on the following factors 1. Pressure * The rate of filtration of liquid is instanter comparative to the pressure difference among the filter medium and filter cake. * Thus, the rate of filtration buns be emergenced by applying pressure on the liquid being filtered or by decreasing the pressure to a inflict place the filter. 2. Viscosity * The rate of filtration is reciprocally proportional to the viscosity of the liquid undergoing filtration. Liquids which are precise viscous get filtered slowly in comparison to liquids with low viscosity. * Reduction of viscosity of a liquid by raising the temperature is frequently done in ordinance to accelerate filtration. eg syrups are more quick filtered when hot and cold. 3. Surface demesne of filter media * The rate of filtration is directly proportiona l to the surface area of filter media. * Pleating the filter paper or using a fluted funnel increases the effective surface area of filter paper for filtration. Filter press also works on the same principle. 4. Temperature of liquid to be filtered Temperature plays an important role in the rate of filtration. * Viscosity is reduced by a rise in temperature and the filtration of viscous oils, syrups etceterais a great deal accelerated by filtering them while they are still hot. 5. Particle size of it of it of it * The rate of filtration is directly proportional to the particle size of the solid to be charterd. * It is easier to filter a liquid having gritty particles than that having finely divided particles because abrupt filtering medium prat be use to filter liquid having large-grained and consequently it increases the rate of filtration. Therefore before filtration, some method should be adopted to agglomerate the finely divided particles into impolite particles or t o increase the particle size by precipitation. 6. Pore size of filter media * The rate of filtration is directly proportional to the pore size of the filter media. * The liquid having coarse particles requires a coarse filtering media to remove them. So, the rate of filtration is increased when a coarse filter medium is utilize for filtration. 7. Thickness of cake * The rate of filtration is inversely proportional to the thickness of the filter cake mannikined during the process of filtration. As the filtration process proceeds, the solid particles start depositing on the filter medium, and thus, it increases the thickness of the cake and decreases the rate of filtration. 8. Nature of the solid material * The rate of filtration is directly proportional to the porosity of the filter cake. * The porosity of the filter cake depends on the constitution of the solid particles to be removed from the liquid. * Filter aids are some propagation added to the filtering liquid to make a poro us cake Theories of filtrationThe commingle of a liquid fundamental a filter follows the basic rules that govern the flow of any liquid through the medium offering rampart. The rate of flow whitethorn be expressed as Driving draw off Rate = ( comparison 1) Resistance The rate of filtration may be expressed as majority (lit) per whole time (dv/dt). The driving extract is the pressure differential between the upstream and downstream of the filter. The resistance is non constant.It increases with an increase in the certification of solids on the filter medium. Therefore filtration is not a steady state. The rate of flow will be greatest at the beginning of the filtration process, since the resistance is minimum. Once the filter cake is goed, its surface acts as filter medium and solids unceasingly deposit adding to the thickness of the cake. The resistance to flow is related to some(prenominal) factors as mentioned below. Length of capillaries Resistance to movement = Poiseuilles EquationPoiseuilles considered that filtration is similar to the stream line flow of a liquid under pressure through capillaries. Poiseuilles equation is ? pr4 V = 8L? Where, V= rate of flow, i. e. , mess of liquid flowing in unit time, m3/s(1/s) p = pressure difference across the filter, pa r = radius of the capillary in the filter bed, m L = thickness of the filter cake (capillary length), m = viscosity of filtrate, pa s If the cake is composed of a loudnessy mass of particles and the liquid flows through the interstices (correspond to a multiplicity of capillary tubes), and then the flow of liquids through these may be expressed by poiseulles equation. Darcys Equation Poiseuilles law assumes that the capillaries found in the filter are highly irregular and nonuniform. Therefore, if the length of a capillary is taken as the thickness of the bed, correction factor for radius is applied so that the rate equation is closely approximated and simplified.The factor inf luencing the rate of filtration has been incorporated into an equation by Darcy, which is KA P V = ? L Where, K = permeability coefficient of the cake, m2 A = surface area of the porous bed (filter medium), m2 p = pressure difference across the filter, pa L = thickness of the filter cake (capillary length), m ? = viscosity of filtrate, pa sThe term K depends on the peculiaritys of the cake, such as porosity, surface area and sponginess. Permeability may be defined quantitatively as the flow rate of a liquid of unit viscosity across a unit area of cake having unit thickness under a pressure gradient of unity. This model relates not only to filter beds or cakes but also applies to other qualitys of shrewdness filter. Equipment is valid for liquids flowing through sand, cods hem inop beads and various porous media. Darcys equation is further modified by including characteristics of K by Kozeny-Carman. Kozeny-Carman EquationPoiseuilles equation is do applicable to porous bed, b ase on a capillary eccentric mental synthesis by including supernumerary parameters. Thus the resultant equation, which is widely utilise for filtration is Konzeny- Carman equation. A p ? 3 ?S2 KL (1- ? )2 V = - Where, ? = porosity of the cake (bed) S = specific surface area of the particles comprising the cake, m2/m3 K = Konzeny constant p = pressure difference across the filter, pa L = thickness of the filter cake (capillary length), m ? = viscosity of filtrate, pa sThe Konzeny constant is ordinaryly taken as 5. The effect of compressibility of the cake on flow rate merchant ship be comprehended from equation (1), since the flow rate is proportional to ? 3/ (1- ? )2. A 10 percent change in porosity back produce most 3-fold change inn V. Limitations of Kozeny Carman equation Kozeny Carman equation does not take in to account of the fact that the depth of the granular bed is lesser than the developed path traversed by the fluid. The actual path is not straight throughout the bed, but it is sinuous or tortuous Mechanisms of filtrationThe mechanism whereby particles are kept up(p) by a filter is significant only in the initial stages of filtration. Some of the mechanisms are Straining Similar to sieving i. e. , the particles of larger size cannot pass through the eleganter pore size of the filter medium. Impingement Solids having caprice move along the path of streamline flow and strike (impinge) the filter medium. Thus, the solids are retain on the filter medium. Entanglement Particles become entwined (entangled) in the mass of eccentrics (of cloth with a fine h line of credity surface or porous felt) due to smaller size of particles than the pore size.Thus the solids are retained on the filter medium. Attractive forces Solids are retained on the filter medium as a result of attractive forces between particles and filter medium, as in case of electrostatic precipitation. come home MEDIA AND FILTER AIDS Filter media The filter medium act as a machinelike support for the filter cake and is also responsible for the accrual of solids. Filter medium should hire the following characteristics 1. It should have sufficient mechanical strength. 2. It must be indolent it should not show chemical or physical interaction. 3.It should not absorb the dissolved material. 4. It should allow the maximum transportation of liquid, while retaining the solids. It means that it must offer low resistance to flow. The order of the resistance of the filter medium will change due to the layers of solids deposited earlier, which may block the pores or may form bridges over the entrances of the channels. Therefore, the pressure should be kept low at the beginning to avoid the plugging of the pores. The usual procedure is to filter at constant rate by change magnitude the pressure as necessary. When normal working pressure is reached, it is maintained.On continue filtration, the thickness of the cake further builds up and hence the rate of fil tration decreases. When the rate is uneconomical, filtration is stopped. The filter cake is removed and filtration is restarted. Materials The following materials are used as filter media 1. Woven materials such as felt or cloth * Woven material is made of wool, cotton, silk, sugarcoat, metal or synthetic fibres (rayon, nylon etc. ) * Synthetic fibres have greater chemical resistance than wool or cotton, which are affected by alkali and acid respectively. * The choice of the fibre depends on the chemical reactivity with the slurry. . pierce poll metal * For eg faultless vane plates have pores which act as channels as in case of meta filter (edge filter). 3. Bed of granular solid built up on a supporting(a) medium * In some processes, a bed of musical scored solids may be formed to reduce the resistance to the flow. * Typical examples of granular solids are gravel, sand, asbestos, paper, pulp and keiselguhr. * The choice of solids depends on the size of the solids in the proce ss. 4. Prefabricated porous solid unit * Porous solids prefabricated into a wholeness unit are being increasingly used for its convenience and effectiveness. mold glass, sinter metal, earthenware and porous plastics are some of the materials used for the fabrication. 5. Cartridge filter media * Cartridge units are economical and forthcoming in pore size of 100m to even less than 0. 2 m. * These can be used any as surface cartridges or depth type cartridges. a) Surface type cartridges * These are corrugated and resin treated papers. These are used in hydraulic lines. * Ceramic cartridges are advantageous in change for reuse by back flushing or firing. * Porcelain filter candles are used for sterile filtration. ) Depth type cartridges * These are made of cotton, asbestos or cellulose. * These are disposable items, since cleaning is not feasible. Filter Aids Filter aid forms a surface deposit which permeates out the solids and also prevents the plugging of the supporting filter m edium. The important characteristics of the filter aids are 1. Chemically inert to the liquid being filtered and free from impurities. 2. pitiful specific gravity, so that filter aids remain suspended in liquid. 3. Porous rather than dense, so that previous cake can be formed. 4. Recoverable JustificationThe target area of the filter aid is to prevent the medium from becoming blocked and to form an open, porous cake, hence reducing the resistance to flow of the filtrate. a) normally low resistance is offered by the filter medium itself, but as layers of solid built up the resistance will be increased. The cake may become impervious by blocking of the pore in the medium. black market rate is inversely proportional to the resistance of the solid cake. b) Slimy or gelatinous material and highly compressible substances form impermeable cakes. The filter medium gets plugged and the flow of filtrate stops.Disadvantages * The filter aids remove the coloured substances by absorbing them. Sometimes active principles such as alkaloids are absorbed on the filter aid. * Rarely, filter aids are a source of contaminants such as soluble iron salts, which can provoke degradation of sensitive ingredients. * Liquid retained in the pores of the filter cake is lost in the manufacturing process. Example of filter aids * Keiselguhr, Talc, Charcoal, Asbestos, typography pulp, Bentonite, Fullers earth * Activated charcoal is used for remotion of organic and inorganic impurities. Keiselguhr is a successful filter aid and as little as 0. 1% can be added to the slurry. The rate of filtration is increased by 5 times or more, at the above concentration, though the slurry contains 20% solids. platterussion of filter aids Filter aids are mostly used for clarification processes, i. e. , where solids are discarded. Different flow rates can be achieved depending on the grade of the aids. * Low flow rate (fine solids) fine grade filter aids chiefly intended for clarity. * Fast flow rat e (coarse solids) -coarse grade filter aids acceptable filtrate.The filter aid can be employed in either one or both(prenominal) ways. a) Firstly, a pre coat is formed over the medium. For this purpose, a suspension of the filter aid is filtered to give a coating up to 0. 5/m2. b) Secondly, a small proportion of filter aid (0. 1-0. 5% of total grasp weight) is purposely added to the slurry. So the filter cake has a porous structure and filtration can be efficient. The filter aid of 1-2 parts per each part of contaminant is ruffleed in the feed tank. This slurry is re circulated through the filter until a clear filtrate is obtained. Filtration then proceeds to completion.The body mix method minimises equipment requirement and cross contamination potentials. Sterile Filtration Sterile filtration is carried out for removal of microorganisms from fluids. It is a cheap and satisfactory method for sterilizing heat-sensitive (thermolabile) materials. The method implies the use of membra ne filters which do not impart any particulate matter, fibers, or chemical reaction to the filtrate unlike unglazed porcelain candles, asbestos go ballistics and other filters. In addition, no pretreatment is required, cleaning is no problem and the filters can be autoclaved or gas sterilized after assembly in its holder.Even when asepsis is not warranted but polishing (removal of particulate matter including live or dead bacterial cells in order to obtain high virtuousness and clarity) is desired in products like oral or topical antibiotic drug preparations, membrane filters are the best choice. The following filters are used for bacterial filtration 1. Candle filter 2. Seitz filter 3. Edge filter 4. Sintered glass filter 5. Membrane filter Candle filters Candle filters are made of unglazed porcelain and are available in various porosity grades, either cylindrical or in the shape of the rimd test tube.Normally the filtration is so carried out that the liquid flow is from is from outside inward and greater filtration surface is available to the incoming liquids. Candle filters can be sterilized by traveling, by hot moist air, or by autoclaving. Cleaning may be affected by drawing a large volume of distilled water through the candle filter thereby completely backwash the previous solution from the pores. Thus the surface of the filter should be piano scrubbed with a comfortable brush, rinsed well with water and finally enkindled in a muffle furnace. The main disadvantage of such filters s that the pores become plugged with organisms and debris which necessitate a very thorough cleaning. Sietz filter It consists of an asbestos pad. The pads are available in several porosities that make them rich for polishing of solutions as well as removal of bacteria. Unless however the filter is backed with nylon mesh or sintered stainless blade fibers now and then get into the solution. The lower edge is fitted with a broad flat flange and the upper part is cylindric al. A perforated plate fitted into a lower part of the funnel supports the asbestos pad.As the pads are meant only for single use, the cleaning of filter media is no problem. Each time a fresh pad is to be used. The apparatus is simple in operation but worthy mostly for small quantities of liquids. Sintered glass filters These are made of borosilicate glass. Borosilicate glass is finely powdered, sieved and particle of desired size are stray. It is then have a bun in the ovened in to a disc mould and heated to a temperature at which adhesion takes place between the particles. The disc is then fused to a funnel of fitting shape and size. The sintered glass filters are available in different pore size.Hence the funnel with a sintered filter is numbered according to the pore size. The filtration is carried out under reduced pressure. These funnels are used for bacterial filtration. Sintered filters are also available in stainless steel which has a greater mechanical strength. Howe ver these are very much liable to attack by the solutions passing through them. Edge filters In edge filters a pack of the filter media used and filtration is done edges by passing the liquid or slurry between and not through the media. Such filtration must be conducted under pressure or under partial vaccum system.Meta filter and stream line filter are two types of edge filters but the former is of greater use in pharmaceutic industry. Meta filters Meta filters are effectual in those manufacturing processes where filter presses are not frequently suitable. It requires no cloth, gauges, paper etc. and may be used at any pressure and temperature and for any liquid. It can be exhaustively cleaned after each operation. In its simplest form, meta filters consists of a grooved drainage rod or guide tube on which a series of sound are packed. On keeping the pack and learns its way along the grooves in drainage rod and ultimately to the receiver.These may be operated with pressure or u nder vaccum system. The rings are usually of stainless steel, of about 15mm interior diameter, 22mm outside diameter and 0. 8mm in thickness, with a number of semicircular projections on one surface. These pressure filters can be used for the filtration of very viscous liquids such as syrups or oils by fitting a steam jacket and rendering the liquids less viscous. They are also effectual in the clarification of injection solutions and products such as insulin liquids. This type of filter can be cleaned easily by back-flushing with water or steam.Because of the shape of the pores in the ring, back-flushing will wash away the filter bed completely. Meta filters are very economic in use. Streamline filters Operation wise and also geometrically, the streamline filter is similar to meta filter but the cylindrical filter pack consists of compressed paper discs. The liquid flow takes place radially inwards through the small space between individual papers and through the papers themselv es. Membrane filters * Ultra filtration methods have become popular in recent years mainly due to increased refinement of various membranes. Cellulose and cellulose derivatives are mostly commonly used materials for these filters. They are available in a wide range of pore sizes, ranging from 8 down to 0. 22. * However, for sterile filtration, membranes with pore size of 0. 22 to 0. 45 are usually specified. * As such fine porosity of membranes may get impede rapidly, a prefilter is used to remove colloidal matter in order to extend the filtration cycle. * The filter primarily acts as a simple screen and retains on its surface all particles of size greater than the pore size of the filter (resembling sieving action). Due to an enormous number of very fine pores, the pore volume approximates 80% of the total volume of the membrane. * The action of the filter is mainly due to the combined forces of gravity and van Der Waals forces. * Membrane efficiency can be predicted in terms of its bubble point which is a characteristic function of porosity. It is defined as the pressure required to push air through a liquid saturated filter. Filter pores retain liquid until this point is reached. * Each membrane has specific bubble point which depends on the liquid wetting the membrane. An obvious disadvantage of membrane filter is their brittleness when dry and this makes intervention difficult. The use of filters in cartridge form, overcomes this problem. * Apart from the small laboratory models, large models are available for pilot plant and small scale production to handle up to about 25litres/minute of liquid through a 0. 45 pore size membrane. * Membrane filters find extensive use in filtration and sterilization of a variety of pharmaceutical products such as ophthalmic and intravenous solutions, other aqueous products, biological preparations, hormones and enzymes. In conjunction with a suitable pipette syringe, it is very useful in dispensing measured volumes of sterile fluids. * This assembly is often utilized for handling of pharmaceutical, biological and bacteriological preparations which can be damaged by metal(prenominal) contact. Centrifugation Centrifugation is a unit operation employed for separating the constituents present in the statistical distribution with the aid of the outward-moving force. Equipment used for centrifugation is centrifuge. Centrifugal force is used to result the driving force for the separation. It replaces the gravitation force in the sedimentation.Centrifugation is particularly useful when separation by ordinary filtration is difficult. Centrifugation provides convenient method of separating two incompatible liquids or solid from liquid. * Centrifugation is a separation process which uses the action of outward-developing force to promote accelerated settling of particles in a solid-liquid compartmentalisation. * If particles size in the dispersions is 5 micro meter or less, they undergo Brownian mot ion, hence they do not Sediment under gravity, therefore a stronger force, centrifugal force is applied in order to separateTwo clean-cut major phases are formed in the vessel during centrifugation Thesediment Usually does not have a uniform structure. Thecentrifugateorcentratewhich is the supported liquid. Process of centrifugation The centrifuge consists of a container in which mixture of solid and liquid or two solids is placed and rotated at high hurryings. The mixture is separated into its constituent parts by the action of the centrifugal force on their densities. A solid or liquid with higher(prenominal) specific gravity is thrown outward with greater force & it is retained at the female genitals of the container leaving a clear supernatant liquid.The speed of the centrifuge is commonly expressed in terms of number of revolutions per minute. scheme of centrifugation If a particle (mass = m kg) spins in a centrifuge (radius r, m) at a velocity (v, m s-1) then the centri fugal force (F, N) acting on the particle equals m v2/r. The same particle experiences gravitational force (G, Newton) = m g (where g = acceleration due to gravity) Centrifugal force = f = mv2/r Centrifugal effect (C) = F/G = mv2 /mgr (v = 2 ? r n ) c = (2? r n)2/ g r = 4 ? 2r n2/ g (d= r/2) = 2 ? 2 d n2/ g (g = 9. 807) C = 2. 013 d n2 Centrifugal effect, C= 2. 013 n2d n= speed of rotation( revolution per due south of centrifuge) * d= diameter of rotation So * Centrifugal effect is directly proportional to diameter of rotation * Centrifugal effect is directly proportional to (speed of rotation)2 There are two main types of centrifuge used to achieve separation on an industrial scale, * Filtration centrifuge Those using perforated hand wicketball hoops, which suffice a filtration-type operation (work like a spin-dryer) and * Sedimentation centrifuge Those with a solid jettyed vessel, where particles sediment towards the wall under the influence of the centrifugal orce Perforate d basket centrifuge Figure Perforated Basket cartridge remover In this type of centrifuge, a basket is mounted above a driving light beam. This type of centrifuges are used for batch processes. Principle Perforated basket ( coil) centrifuge is a filtration centrifuge. The separation through a perforated wall based on the difference in the densities of solid and liquid phases. The sphere contains a perforated side wall. During centrifugation, the liquid phase passes through a perforated wall, while solid phase is retained in the bowl.The solids are removed after stopping the centrifuge. Construction It consists of a basket, made of steel (sometimes covered by vulcanite or led) or copper. The material of structure should be such that it offers greatest resistance to corrosion. The basket may have diameter of 0. 90 meters and capacity of 0. 085 meter cube. The diameter of perforations must be based on the size of crystals to be separated. The basket is suspended on a vertical shaft and is driven by a ram using suitable power system.Perforated basket is kept in a casing which collects the filtrate and discharges it through outlet. work The material to be separated kept in the basket. The loading of material must be done to give an even distribution. The power is applied to run the basket at speed of 1000 rpm. During centrifugation the liquid passes through the perforated wall and solid phase retaind in the basket. Uses * Perforated basket centrifuge is extensively used for separation of crystalline drugs (aspirin) from mother liquor. Sugar crystals are separated using the perforated basket centrifuge. * Precipitated proteins from insulin can be separated. Advantages * The process is rapid * The final product has low moisture content * It cam handle slurries with high proportion of solids even those having paste like consistency * Dissolved solids from cake can be separated. Disadvantages * On prolonged operation solids may form hard cake. * It is a batch pro cess. Non-Perforated Centrifuge Principle This is sedimentation centrifuge.The separation is based on the difference in the densities of solid and liquid phases without a porous barrier. The bowl contains a non perforated side wall. During centrifugation, solid phase is retained on the sides of the basket and liquid remains at the top removed by skimming tube. Construction It consists of a basket, made of steel (sometimes covered by vulcanite or led) or copper. The material of construction should be such that it offers greatest resistance to corrosion. The basket is suspended on a vertical shaft and is driven by a repel using suitable power system Working The feed is continuously introduced into the centrifuge while the liquid (centrate) is continuously removed from an overflow weir inside(a) the centrifuge * Solids build up during centrifugation forming a cake that must be periodically fulfill Figure Non-Perforated Basket Centrifuge * After the basket becomes filled with solids the centrifuge slows down and skimming (the removal of the top semi-liquid soft cake layer) takes place * Skimming typically removes 5 to 15% of the bowl solid volume * The bulk of the cake is discharged using a ploughing knife moving into the slowly rotating cake * The solid is discharged centrally at the bottom of the centrifuge * Solid accumulation is typically up to 60 to 85% of the maximum available depth * This type of centrifuge is typically operated at low centrifugal forces and has a comparatively low solid handling capacity. The imperforated basket centrifuge is the only basket centrifuge commonly used for typical sludge dewatering applications. * High solid recovery can be achieved with this centrifuge even without chemical additives. Uses Non-perforated basket centrifuge is useful when deposited solids offer high resisttance to the flow of liquid. Conical disc centrifuge Principle It is a sedimentation centrifuge. The separation is based on the difference in the the de nsities between phases under the influence of centrifugal force. In this a number of cone shaped plates are attached to the central shaft (which has provision for feed) at different elevations.During centrifugation, the dense solids are thrown outwards to the underside of cone shaped casing. While lighter comminuted liquid passes over bowl and collected from top of the cone. Construction It consists of shallow form of bowl containing series of conic discs attached to the central shaft at different elevations. The discs are made up of thin sheet of metal or plastic separated by narrow spaces. A concentric tube is placed surrounding the central drive shaft. Working The feed is introduced into the concentric tube surrounding the drive shaft. The feed flows down and enters the spaces between the discs. The solids and heavier liquids thrown out ward and move underside of the discs.Low speed and short time of centrifugation is sufficient to give high distributor point of clarification. Uses * Two immiscible liquids can be easily separated by continuous process after liquid-liquid extraction in manufacture of antibiotics. * Precipitated proteins in manufacture insulin can be clarified. Advantages * Conical disc centrifuge is buddy-buddy and occupies very less space. * By controlling speed of rotation and rate of flow, particles are separated into two sizes. * Separating efficiency is very high. Disadvantages * Capacity of conical disc centrifuge is extra * Construction is complicated * Not suitable if sediment of solids form hard cake. Figure Conical Disc Centrifuge Tubular bowl centrifuge The tubular bowl centrifuge has been used for longer than most other designs of centrifuge. It is based on a very simple geometry it is formed by a tube, of length several times its diameter, rotating between bearings at each end. The process stream enters at the bottom of the centrifuge and high centrifugal forces act to separate out the solids. The bulk of the solids will ad here on the walls of the bowl, while the liquid phase exits at the top of the centrifuge. * As this type of system lacks a provision of solids rejection, the solids can only be removed by stopping the machine, dismantling it and scratch or flushing the solids out manually. Tubular bowl centrifuges have dewatering capacity, but limited solids capacity. Foaming can be a problem unless the system includes limited skimming or centripetal pumps. Figure Tubular bowl centrifuge * This type of centrifuge can also be used to separate immiscible liquids. * Rate of sediment can be control by controlling the inlet rate. * The uses of centrifugal sedimenters include liquid/liquid separation, e. g. during antibiotic manufacture and purification of fish oils, the removal of very small particles, the removal of solids that are Compressible and which easily block the filter medium, The separation of simple eye plasma from whole blood (need C =3000).