Synthesis and Characterization of Tetraphenyltin

Synthesis and Characterization of Tetraphenyltin ABSTRACTS Tetraphenyltin in high yield has been prepared by the reaction of chlorobenzene, chlorotin (IV) and sodium metal in dry toluene characterized by Infra-red spectroscopy. Introduction Organic compounds that contains metal-carbon bond are called organometallic compounds. Organometallic compounds have been studied for nearly 200 years. Unique properties of these compounds have been used in many areas of life. The reactivity of organometallic compounds depends on the reduction potential of metal. For preparation and use, it is markedly observed that most reactivity requires low to moderate temperature and inert conditions like atmosphere and solvent. Generally the reactivity of these compounds seems like the ionic character of the carbon-metal bond, which may be estimated from the proton and carbon chemical shifts of methyl derivatives. % Ionic character of H3C–Metal as (CH3)2Hg 3)2Cd 3)2Zn 3)2Mg 3L [1]. The first reported organometallic compounds were prepared by the reductive substitution of alkyl halides. Alkali metals have strong or moderate negative reduction potentials, with lithium and magnesium being the most reactive. Halide reactivity increases in the order: Cl _R) tends to predominate. This can also be a problem when allyl or benzyl halides are converted to Grignard or lithium reagent [2]. Organometallic compounds of group (IV) elements There is an exceedingly extensive chemistry of the group four elements bound to carbon and some of the compounds, notably silicon-oxygen polymers and alkyl tin and lead compounds are of commercial importance. Essentially all the compounds are of the type M(IV) type. In the divalent state the only well established compounds are cyclopentadienyl tin alkyls or aryls of formula R2Sn are either transitory or non-existent, and the stable substances of this stoichiometry are linear or cyclic polymers of tetravalent tin. For all the group four elements the compounds can generally be designated R4-nMXn where R is the alkyl or aryl and X can vary widely being H, Cl, O, COR, OR, NR2SR etc. For a given class of compounds those with C-Si and C-Ge bonds have higher thermal stability and lower reactivity than those with bonds to Sn and Pb [3]. Organometallic compounds of Tin There are four series of organotin compounds depending on the number of carbon-tin bonds. These series are designated as mono-, di-, tri-, and tetraorganotin compounds with the general formula: RnSn X4-n Where R = an alkyl or aryl group Sn = the central tin atom in the oxidation state +4 X = a singly charged anion or an anionic organic group [4]. Complexes of transition metals The ability of transition metals to form organo derivatives only begins to be appreciated properly during the nineteen fifties. Nonetheless, the organometallic compounds of transition metals now constitute an enormous, diversified field of chemistry, which is still expanding rapidly. It begins breadth by merging into the field of metal carbonyls and related compounds. They also differ in structure from that of non-transition organo-metal derivatives. The transition metals form compounds in which there is metal to carbon sigma bond although pi bond in some cases may also be formed. More important, the unique characteristic of d orbital allow certain type of unsaturated hydrocarbons and some of their derivatives to be bound to metals in a non-classical manner to give molecules or ions with structures that have no counterpart elsewhere in chemistry. Not only is a wide range of organo compounds of different types are isolable, but also labile species play an important role in olefins, acetylene and their derivatives catalyzed by metal complexes [5]. Applications of Organotin compounds Depending on the organic groups, they can be powerful bactericides and fungicides [4]. Tributyltins are used as industrial biocides, eg. as antifungal agents in textiles and paper, wood pulp and paper mill systems, breweries, and industrial cooling systems. Tributyltins are also used in marine anti-fouling paint [1]. Triphenyltins are used as active components of anti fungal paints and agricultural fungicides [5]. Organotin compounds are widely studied class of meta-based antitumor drugs [2]. Organotin compounds are used in treatment of hyperbilirubinaemia [2]. Organotin compounds are used in chemicals used for wood preservation [1]. Addition of Organotin compounds to PVC increases its stability [1]. Organo metallic transition complexes also have role in molecular rearrangement processes [2]. Hypercoordinated Stannanes Tin compounds can also be coordinated to five atoms instead of the regular four unlike their carbon analogues. The stability of these hypercoordinated compounds is managed by electronegative substituent. In 2007 a stable organotin (all carbon pentaorganostannane) was reported at room-temperature (in argon) [4] in the form of lithium salt with the following structure. The geometry of the molecule is distorted trigonal bipyramidal. The carbon to tin bond lengths are 2.26Ã… apical, 2.17Ã… equatorial. These are larger than regular C–Sn bonds (2.14Ã…) which shows its hypervalent nature. Biological Aspects The chemistry of the organotin(IV) derivatives is being subject of study with growing interest, not only because of the environmental consequences of the widespread use of these compounds, but also as due to the increasingly importance of their medical assays for bactericide and antitumor purposes. In this respect, various triorganotins have been reported recently to be effective against mosquito larvae and adult mosquitoes responsible for malaria and yellow fever, and also some phenyltin derivatives display cardiovascular activity. In general, the structure-activity relationship in this kind of compounds is still subject of controversy, but it seems been established that, for instance, in the case of triorganotin carboxylates, those containing trans-O2SnC3 moieties exhibit a greater biocidal activity than those containing cis-O2SnC3. Organotin compounds have been implicated as reproductive toxicants and endocrine disruptors primarily through studies in aquatic organisms, with little information available in mammals. Among the organotins, aryltins have been less studied than alkyltins. Extensive data is available on mammalian developmental and reproductive toxicity of one aryltin compound, triphenyltin (TPT), from toxicity studies conducted in connection with the registration of triphenyltin hydroxide (TPTH) as a pesticide and supporting publications from the open literature. Indications of adverse functional and morphological effects on the reproductive tract of rats were reported in a dose range of 1.4-20 mg/kg/d. Gonadal histopathology (both ovaries and testes) and infertility were affected at the higher doses, while reproductive-tract cancer, smaller litter sizes, and reproductive organ weights were affected at the lower end of the dose range. In vitro studies indicate the TPT can directly activate androgen re ceptor-mediated transcription and inhibit enzymes that are involved in steroid hormone metabolism. These data suggest that the aryltin TPT can be active as a reproductive toxicant in mammals and may be a human endocrine disruptor. Organotins are one of the classes of compounds implicated as â€Å"endocrine disruptors† (Colborn Clement, 1992) primarily on the basis of the finding of imposex in aquatic gastropods (Smith, 1981; Horiguchi et al., 1994). In these organisms, genetic females and parts of the male reproductive system, including the penis and vas deferens, superimposed on a normal female genital system. Implications for mammalian reproduction are less explored. There are no available epidemiological studies of the reproductive toxicity of organotins in humans or mammalian wildlife populations, so that mammalian reproductive toxicity information is limited to laboratory animals. Among the organotins, a particularly large database on reproductive toxicity in laboratory animals is available through studies conducted for registration of triphenyltin hydroxide as a pesticide. Triphenyltin (TPT) came into use as a fungicide and matricide in the 1950s (HSDB, 1998). Currently, about 10 products containing TPT are registered for use as pesticides by the U.S. Environmental Protection Agency (U.S. EPA). Registration for TPT hydroxide was cancelled in California in 1983. TPT acetate and hydroxide were banned from use in the European Union (EU) in 2002 (Lo et al., 2003). This review presents and integrates information on reproductive toxicity from the triphenyltin hydroxide (TPTH) registration database made available through the Freedom of Information Act (FOIA), and includes papers on mammalian reproductive toxicity of other TPT salts. In this review, information from the pesticide registration data is presented in some detail since it is not available. Estimates of exposure for total tin indicate that the main route in the general population is from food, about 4 mg/d. A national survey in the United States in 1982 reported 8.7-15 à ¯Ã‚ Ã‚ ­g tin/g in human adipose tissue (ATSDR, 1992). However, these estimates are based on outdated information, and much of the tin came from canned foods (inorganic tin) (ATSDR, 1992). The most recent information for TPT is from Japan (Tsuda et al., 1995). Duplicate portion studies indicated an intake of 0.7 à ¯Ã‚ Ã‚ ­g TPT/d in 1991 and 1992, and market basket surveys indicated intakes of 5.4 and 1.3 à ¯Ã‚ Ã‚ ­g TPT/d in 1991 and 1992, respectively. Analytical techniques are now becoming available to separate various forms of inorganic and organic tin which promise more accurate human exposure assessment. Chemical equations 2Na + C6H5Cl C6H5Na + NaCl 4 C6H5Na +SnCl4 (C6H5)4Sn + 4NaCl Reagents required: 275 ml of dry toluene (350 ml if wet) 35 ml of chlorobenzene 15 gm of sodium 10 ml of SnCl4 Dry ice Special apparatus required: 500 ml, three neck, round-bottom flask Variac High-speed stirring motor Stirring rod with sharp metal blades Cylinder of argon About 1000 ml of kerosene in pane Extra sintered-glass funnels and filter flask Procedure Fifteen grams of clean sodium chunks and 250 ml of dry toluene are placed in the flask. A thermometer and an argon inlet tube are inserted through one of the side arm of the flask. The other side arm is Stoppard. Insert the stirrer through the main mouth of the flask, taking care of that the stirring blades cannot hit the thermometer and that they are above the chunks of sodium. While stirring gently, and with a slow stream of argon flowing, heat the contents slowly to 105 °. Then lower the stirrer so that the blades are about 1cm from the bottom of the flask and turn the stirrer on full power. It will be found necessary to increase the power input to the heating mental in order to keep the temperature at 105 °. After about 10 min of vigorous stirring at 105 °, remove the heating mantle from the flask. When the temperature has fallen to 99 °, stop the stirrer and allow the flask to cool to room temperature. The sodium should now be in the form of fine sand. Stir the sodium ge ntly to see if any of the particles have agglomerated. If so, the process must be repeated. If the sodium dispersion is not be used immediately, thoroughly flush the flask with the argon and tightly stopper it. Using the heating mantle, heat the dispersion, with moderately vigorous stirring, to 45 °. Attach a dropping funnel containing 35 ml of chlorobenzene to the unused side arm and add 2 to 3 ml of the chlorobenzene to the flask. Notice: The flask should never contain more than 3 ml of un reacted chlorobenzene! If more than this amount is present, an uncontrollably vigorous reaction may take place, resulting in a fire. Remove the heating mantle from the flask. The reaction should start, as evidenced by a rise in the temperature. If the reaction does not start at 45 °, cautiously rise the temperature to 50 ° (no higher!). If the reaction starts at this temperature, the temperature may suddenly rise to as high as 55 °, so be ready to cool the flask quickly with the kerosene bath. (If the reaction does not start at 50 °, cool the flask to room temperature, cautiously hydrolyze the mixture with alcohol, and discard). Temperature in access of 50 ° will not cause great harm at the beginning of the synthesis, but thereafter the temperature must be kept below 45 °; keep the flask partially immersed in the kerosene bath and cool the kerosene bath by occasionally adding pieces of DRY Ice to it. The temperature of the reaction mixture may be held between 40 and 45 ° by adjusting the rate of addition of chlorobenzene. After all the chlorobenzene has been added (about 1 to 2 hours), place a solution of 10ml of stannic chloride in 25ml of toluene in the dropping funnel, and, over a period of 30 min, add this solution to the reaction flask. During this addition, it is necessary to cool the flask so as to keep the temperature below 45 °. The flask now be stored indefinitely (without protection from the air) until the tin tetra phenyl is extracted from the mixture. Wipe the kerosene from the bottom of the flask, and, with moderate stirring, heat the mixture to incipient boiling and quickly filter through a sintered-glass funnel. It is best to keep most of the solid residue in the reaction flask. Cool the filtrate to room temperature and filter off the product on another sintered-glass funnel. Return the filtrate to the original flask and repeat the extraction two or three times until no more product precipitates on cooling the solution to room temperature. It is helpful to add another 100 ml of toluene to the mixture to reduce the necessary number of extractions. The final solution should be cooled in an ice bath before filtering. Suck the crystals of tin tetra phenyl as dry as possible on the filter and then let them air dry for 4 to 20 hours on a watch glass. A yield of about 25 gm of material melting at 266 to 228 ° should be obtained. A pure product (melting at 299 °) may be obtained by re crystallization from benzene or toluene. RESULTS AND DISCUSION Physical data for reported compounds are given in Table 1. Compound # Empirical formula M.P ( °C) Solubility % Yield 1. (C6H5)4Sn 110-112 Toluene, Ethanol, Chloroform 72 IR spectroscopy IR is one of the most important spectroscopic methods used for qualitative and quantitative analysis. It is based on the fact that each compound has its own unique spectra and certain functional groups absorbat about the same wavelength even in different molecules. Its single most important use has been for the identification of organic compounds whose spectra are generally complex and provide numerous maxima and minima that are used for comparison purposes. Indeed in most instances the IR spectrum of the compounds especially of organic compounds provides a unique finger print, which is readily distinguished from the absorption pattern from all other compounds because only optical isomers absorb in the same way. Absorption of IR radiation is confined largely to molecular species for which small energy differences exist between various vibration and rotational states. As for as spectrum is concerned we see a prominent peak at 457cm-1, which indicates the formation of metal to carbon b ond, which shows the formation of our product. For aliphatic CH peak appear at 3057 cm-1 . References P. Powell, Principles of Organometallic Chemistry, (1988), 2nd edition, Chapman and Hall, New York, pp-1-10. T.Mole and E.A Jaffery, Organometallic Compounds, (1972), 3rd edition, Elsvier Publishing Company, London, pp.89-92. F. Albert and Geoffrey Wilkinson, Advanced Inorganic Chemistry, (1962), 3rd edition, Interscience Publishers, New York, pp-310-312. J.C Bailar, H.J Emeleus, S.R Nhylom and A.F Trotman, Comprehensive Inorganic Chemistry, (1973), 2nd edition, Prgmon, New York, pp.153-157. J.C Bailar, H.J Emeleus, S.R Nhylom and A.F Trotman, Comprehensive Inorganic Chemistry, (1973), 4th edition, Prgmon, New York, pp.89-93. J.W Robinson, Undergraduate Instrumental Analysis, 5th Edition,(995), Marcel Dekker, New York,pp.166-168. A.U Rehman, Nuclear Magnetic Resonance, 1st edition,(1989),pp.90-93.

Operatic Melodrama in Apocalypse Now Essay -- Apocalypse Now Essays

Operatic Melodrama in Apocalypse Now The political and social unrest of the 1970s provided Hollywood with some of its most influential films, often stemming from unlikely sources; two decades after melodrama's heyday, the genre re-emerged in an original form that continues to affect modern filmmaking. The historical influences of Italian opera and Hollywood family melodramas spawned a type of film that has been described as "historical, operatic, choral or epic" (Greene 388). Filmmakers of the 1970s explored the traditional modes of melodramatic expression in order to address the socially charged times they lived in. Filmed in the wake of the Vietnam War, Francis Ford Coppola's Apocalypse Now is a complex treatise of human morality and modern warfare that expresses itself through melodramatic conventions. Coppola contained his war movie to the personal level, in order to make larger criticisms of the Vietnam conflict. The central narrative, based on Joseph Conrad's Heart of Darkness, follows an Oedipal trajectory simila r to those found in many 1950's family melodramas. The surreal, and often ironic use of music provides a startling counterpoint to the actions on screen. The film is imbued with many of the representative motifs, such as sexual dysfunction and alcoholism, which are found in earlier melodramas. Apocalypse Now helped to establish a new film genre - the operatic melodrama - that combined the historical representations of classic melodramas with the raw spectacle of modern filmmaking. Although distinctive melodramatic traditions developed in multiple countries, the Italian model is the most similar to that of the 1970's epic. While some melodramatic traditions evolved through novels or the theatre, "in Italy, ... ... out of a 1950s woman's film. The melodramatic influences of the film continue to manifest themselves in the newer release, just as Apocalypse Now continues to influence the epic movies of contemporary filmmakers. The unison of operatic spectacle and personal conflict spawned an original genre in the 1970s that remains an effective method of addressing social concerns. As we enter another period of political unrest and social change, it is likely that a new wave of melodramatic films is beginning to form on the horizon; there are certainly parallels between a government that declares war on terrorism and the U.S. army in Vietnam, who "knew everything about military tactics, but nothing about where they were or who the enemy was" (Cowie 143). From Conrad to Coppola, nuclear family to nuclear terrorism; never get off the boat, unless you're willing to go all the way. Operatic Melodrama in Apocalypse Now Essay -- Apocalypse Now Essays Operatic Melodrama in Apocalypse Now The political and social unrest of the 1970s provided Hollywood with some of its most influential films, often stemming from unlikely sources; two decades after melodrama's heyday, the genre re-emerged in an original form that continues to affect modern filmmaking. The historical influences of Italian opera and Hollywood family melodramas spawned a type of film that has been described as "historical, operatic, choral or epic" (Greene 388). Filmmakers of the 1970s explored the traditional modes of melodramatic expression in order to address the socially charged times they lived in. Filmed in the wake of the Vietnam War, Francis Ford Coppola's Apocalypse Now is a complex treatise of human morality and modern warfare that expresses itself through melodramatic conventions. Coppola contained his war movie to the personal level, in order to make larger criticisms of the Vietnam conflict. The central narrative, based on Joseph Conrad's Heart of Darkness, follows an Oedipal trajectory simila r to those found in many 1950's family melodramas. The surreal, and often ironic use of music provides a startling counterpoint to the actions on screen. The film is imbued with many of the representative motifs, such as sexual dysfunction and alcoholism, which are found in earlier melodramas. Apocalypse Now helped to establish a new film genre - the operatic melodrama - that combined the historical representations of classic melodramas with the raw spectacle of modern filmmaking. Although distinctive melodramatic traditions developed in multiple countries, the Italian model is the most similar to that of the 1970's epic. While some melodramatic traditions evolved through novels or the theatre, "in Italy, ... ... out of a 1950s woman's film. The melodramatic influences of the film continue to manifest themselves in the newer release, just as Apocalypse Now continues to influence the epic movies of contemporary filmmakers. The unison of operatic spectacle and personal conflict spawned an original genre in the 1970s that remains an effective method of addressing social concerns. As we enter another period of political unrest and social change, it is likely that a new wave of melodramatic films is beginning to form on the horizon; there are certainly parallels between a government that declares war on terrorism and the U.S. army in Vietnam, who "knew everything about military tactics, but nothing about where they were or who the enemy was" (Cowie 143). From Conrad to Coppola, nuclear family to nuclear terrorism; never get off the boat, unless you're willing to go all the way.

Software development and engineering

à ¯Ã‚ ¿Ã‚ ½ There are two features which are common to most engineering definitions à ¯Ã‚ ¿Ã‚ ½ The solution of practical problems for the benefit of humankind à ¯Ã‚ ¿Ã‚ ½ The use of scientific and other formalised knowledge to design and build artefacts within economic constraints Difference between scientists and engineers: à ¯Ã‚ ¿Ã‚ ½ Scientific reasoning and research is essentially inductive, scientists try to infer general rules or laws from the results of a limited number of observations or experimental results à ¯Ã‚ ¿Ã‚ ½ The activities of engineers are quite distinct, their objective is for human benefit rather than explaining the natural world. They make use of scientific results in a deductive way (to verify designs and ideas that are feasible and safe. Development of engineering disciplines QUESTION: How does engineering come to make use of scientific and formalised knowledge? ANSWER: The discipline starts in a state of craft practice: At this stage engineering is carried out by practitioners with little or no formal training and knowledge is acquired during apprenticeship. The second stage is the development of commercial exploitation when pressures arise to make economic use of resources or to increase output. Practice becomes more organised and standard procedures are established. The third stage in development sees the emergence of professional engineering. At this stage engineering is carried out by educated professionals who use formal analysis and scientific theory to understand and verify their designs. Characteristics of engineering Engineering projects tackle clearly defined and quantified problems. Another aspect of modern engineering is the use of systematised knowledge, this knowledge gives the engineer a good understanding both of the problems that he or she is addressing and the materials available for their solution. A science-based knowledge engineer will have considerable knowledge of proven procedures and designs which they can reuse where appropriate. An important aspect of this codified knowledge is the ability to learn from failures. SOFTWARE DEVELOPMENT AS ENGINEERING? Development of compiler technology à ¯Ã‚ ¿Ã‚ ½ In the 1950s when high-level programming languages were first being designed and implemented, compiler writing was regarded as difficult. à ¯Ã‚ ¿Ã‚ ½ The development of the first compiler for FORTRAN, completed in early 1957, required about 18 person-years of effort. à ¯Ã‚ ¿Ã‚ ½ Compiler technology has progressed dramatically since, that a compiler can now be implemented in anything from 6 person-weeks to a person-year. à ¯Ã‚ ¿Ã‚ ½ Modern compilers generally produce executable code that is very efficient and it is rare for programmers to need to resort to lower-level languages. à ¯Ã‚ ¿Ã‚ ½ Compilers are usually extremely reliable being at least as free from errors as most other software on a typical computer. Large-scale development projects Large-scale projects have always been much more prone to problems or failure than smaller developments, such as compiler implementations, due to difficulties of organising and co-ordinating teams, and dealing with clients. But this is not always the case, as seen in these two examples of large and highly successful projects. Example 1: à ¯Ã‚ ¿Ã‚ ½ SABRE, an Airline Reservation System developed for American Airlines. à ¯Ã‚ ¿Ã‚ ½ The project delivered about one million lines of code and involved around 400 person-years of effort. à ¯Ã‚ ¿Ã‚ ½ This success is all the more striking because of the lack of supporting software – there were no database systems available at that time, for example. Example 2: à ¯Ã‚ ¿Ã‚ ½ NASA Space Shuttle. à ¯Ã‚ ¿Ã‚ ½ The project involved introducing rigorous control of software development, tracking all changes and errors, and constantly refining the development process to ensure that errors are eliminated at the earliest possible stage. Other branches of engineering which have resulted in major disasters: à ¯Ã‚ ¿Ã‚ ½ In 1968, Roman point (a high-rise block of flats in London) collapsed after a gas explosion in a top flat. The block was constructed using prefabricated components. à ¯Ã‚ ¿Ã‚ ½ In 1980, the Hyatt Regency Hotel in Kansas City, Missouri, a suspended walkway which connected hotel floors collapsed causing deaths of 114 people. The failure was due to a combination of design and construction flaws. QUALITY AND SOFTWARE DEVELOPMENT In modern industry and business there is enormous concern to try to produce goods and services of high quality. Definition of Quality – ‘The set of characteristics of a product or service which satisfy a customer's requirements and expectations' American Joseph Juran, one of the early advocates of quality management, defined quality as the fitness for uses. Detailed tracking of error statistics during development has been found by developers such as Microsoft, to be extremely useful even though they may adopt a more informal approach to managing software development (Cusumano and Selby 1997). Development of ideas about quality Total Quality Management (TQM): à ¯Ã‚ ¿Ã‚ ½ Clearly defining quality in terms of customers' or consumers' requirements à ¯Ã‚ ¿Ã‚ ½ Concentrating on achieving quality by improving production processes rather than by inspection of end products à ¯Ã‚ ¿Ã‚ ½ The clear specification of processes and the use of statistical analyses and other techniques to track down the sources of faults so that the process can be improved à ¯Ã‚ ¿Ã‚ ½ The involvement of everyone in quality improvement à ¯Ã‚ ¿Ã‚ ½ Constantly trying to improve quality by learning from faults and improving processes and designs. The application of quality management to software development Applicable to software development? Each development of a system is a one-off project so it is not obvious that insights derived from improving manufacturing processes are applicable. The argument of Deming and others that quality cannot be achieved by testing alone is borne out by the experience of many software developers. Quality standards – ISO 9000 In order to achieve ISO 9000 certification: à ¯Ã‚ ¿Ã‚ ½ It has standards against which to measure all aspects of its development practices à ¯Ã‚ ¿Ã‚ ½ It has procedures in place to access performance against these standards à ¯Ã‚ ¿Ã‚ ½ Both the standards and the assessment methods used are recognised in the industry ISO 9000 has been criticised on its particular criteria for introducing too much paperwork and ignoring the importance of continuous improvement. Capability Maturity Model This model is primarily concerned with the way in which projects are managed and organised, so it proposes five levels of maturity in development practices. 1. Initial Level-Not stable environment for developing software. Success heavily dependent on key project staff. 2. Repeatable Level-Managing software projects based on previous experience. Project progress is tracked and under control. 3. Defined Level-A standard process of software development is used across the organisation. Adapted and tailored appropriately for individual projects. 4. Managed Level-Measurable quality targets are set for projects and the results achieved by all projects are monitored. 5. Optimising Level-Measurements obtained from the monitoring of software development are used as a basis for refining and improving the process used. This level is one of continuous improvement. Chapter 11 – Societies for computing professionals WHAT ARE PROFESSIONAL SOCIETIES? à ¯Ã‚ ¿Ã‚ ½ Professionals, such as medicine or the law, are distinguished from other occupations by the long period of training and experience which are required in order to qualify as a practitioner. à ¯Ã‚ ¿Ã‚ ½ Regulated by professional societies à ¯Ã‚ ¿Ã‚ ½ Societies are run by the members of the profession and represent its interests à ¯Ã‚ ¿Ã‚ ½ Not under the immediate control of the government or employers Professional institutions can be made in two ways: à ¯Ã‚ ¿Ã‚ ½ By stature (by passing a law) à ¯Ã‚ ¿Ã‚ ½ Royal Charter The Engineering profession (the institution of Civil Engineers, the institution of Mechanical Engineers, the British Computer Society) have similar rights and responsibilities: à ¯Ã‚ ¿Ã‚ ½ To advance knowledge in their area à ¯Ã‚ ¿Ã‚ ½ To uphold and seek to improve standards of practice (e.g. code of conduct for members) à ¯Ã‚ ¿Ã‚ ½ To set educational and training standards in their field (e.g. running professional exams and accrediting certain degree courses) à ¯Ã‚ ¿Ã‚ ½ To advise the government on issues within their area of expertise (e.g. BCS on the Computer Misuse Act) THE HISTORY OF ENGINEERING PROFESSIONS à ¯Ã‚ ¿Ã‚ ½ When engineering was at the stage of a craft practice, there were few formal mechanisms for the training of new engineers à ¯Ã‚ ¿Ã‚ ½ Throughout most of the nineteenth century British engineers were firmly convinced of the value of practical experience as the basis of training PROFESSIONAL INSTITUTIONS FOR SOFTWARE ENGINEERS Two professional institutions which have most relevance for computer professionals are the British Computer Society (BCS) and Institution of Electrical Engineers (IEE). Engineering Council à ¯Ã‚ ¿Ã‚ ½ Created by Royal Charter in 1981 à ¯Ã‚ ¿Ã‚ ½ Contains 290000 qualified engineers, including about 200000 Chartered Engineers FEANI FEANI represents the engineering profession at a European level and is made of engineering institutions from 27 countries. It was formed in 1951. PROFESSIONAL MEMBERSHIP Members of professional societies gain the benefit of meeting other professionals in their field as well as access to other resources, such as libraries, seminars and special interest groups. Course accreditation Computer Science degree courses which cover similar materiel to that of the BCS exams are often accredited by the British Computer Society. For a degree course to give full exemption it must: à ¯Ã‚ ¿Ã‚ ½ Cover the underlying theory and mathematics appropriate to computing à ¯Ã‚ ¿Ã‚ ½ Have an emphasis on design à ¯Ã‚ ¿Ã‚ ½ Promote understanding of ideas of quality à ¯Ã‚ ¿Ã‚ ½ Cover systems development approaches à ¯Ã‚ ¿Ã‚ ½ Cover ethical, legal, social and professional issues à ¯Ã‚ ¿Ã‚ ½ Include a substantial student project which involves the implementation of an application or tool using an engineering-based approach. Registration with the Engineering Council The Engineering Council maintains a register of qualified engineers. à ¯Ã‚ ¿Ã‚ ½ EA1 – introduction to the fabrication and use of materials à ¯Ã‚ ¿Ã‚ ½ EA2 – application of engineering principlines à ¯Ã‚ ¿Ã‚ ½ EA3 – a thorough and structured introduction to industry, involving practical assignments à ¯Ã‚ ¿Ã‚ ½ EA4 – preparation for the post with responsibility EA1 and EA2 = accredited in engineering degree EA3 and EA4 = period of appropriate work Professional development BCS has developed the Industry Structure Model to classify different roles and responsibilities which computing professionals must have. It identifies some 200 professional functions ranging from programming to management. The purpose of the model is to help individuals and organisations to plan training and career development by identifying current gaps in knowledge. BCS runs two development schemes: à ¯Ã‚ ¿Ã‚ ½ Professional Development scheme – computing professionals have properly planned and verified training Continuing Professional Development – those who have achieved qualification but who need to broaden their knowledge.

Concentration and Molarity Worked Example Problem