Properties of Zeolites as Cataystics

Properties of Zeolites as Cataystics 1.0 INTRODUCTION TO ZEOLITES Zeolites are crystalline aluminosilicates, composed of TO4 tetrahedra (T = Si, Al) with O atoms connecting neighbouring tetrahedral, that contain pores and cavities of molecular dimensions (Breck, 1974). Many occur as natural minerals, but it is the synthetic varieties which are among the most widely used sorbents, catalysts and ion-exchange materials in the world (Barrer, 1982). The channels are large enough to allow the passage of guest species. In the hydrated phases, dehydration occurs at temperatures mostly below about 400 °C and is largely reversible. The framework may be interrupted by (OH, F) groups: these occupy a tetrahedron apex that is not shared with adjacent tetrahedra. Zeolites are different from other porous hydrates, as they retain their structural integrity upon loss of water. The Structure Commission of the International Zeolite Association identifies each framework with a three-letter mnemonic code (Baerlocher et al., 2001) e.g. Amicite- GSI; Faujasite- FAU etc. 1.1 IMPORTANCE OF GREEN PROCESSES In the chemical industry, the acceptability of a process is not only governed by cost and yield but in terms of eco-friendliness and pollution abatement. Choosing a more efficient catalytic route has greatly improved the efficiency of chemical processes. Green chemistry has been defined as the design of chemical products and processes in order to reduce or eliminate the generation of hazardous substances (Armor, 1999). The principles of green chemistry listed by Armor (1999) employs future approaches to new chemical processes. It includes: efficient use of raw materials, energy efficiency, use of biodegradable products and other subtle features. 2.0 HISTORICAL DEVELOPMENT OF ZEOLITES 2.1 NATURAL ZEOLITES Research in the field of zeolite science and technology made its first steps with natural zeolites and was mostly focused on natural zeolites until the beginning of the 1950s. The history of zeolites began in 1756 when Swedish mineralogist A.F. Cronstedt discovered the first zeolite mineral, stilbite when studying its apparent properties discovered its strange behaviour upon heating although there is no certain proof of its identity. The term ‘zeolite was coined from two Greek words, ‘zeo (to boil) and ‘lithos (stone). On the contrary, the first zeolite, chabazite, described by Bosch DAntic in 1792 has clear evidence in literature. Several other zeolites were discovered in the following years and around 1850, only about 20 zeolite types were reported in mineralogy books, including analcime, brewsterite, chabazite, edingtonite, epistilbite, faujasite, gismondine, gmelinite, harmotome, heulandite, laumontite, levyne, mesolite, natrolite, phillipsite, scolecite, stilbi te, and thomsonite. Starting from the middle of the 19th century until about 1975, there was a moderate increment in the number of zeolites discovered (about one new type every 6-7 years) and a clear acceleration in the last twenty five-thirty years. About 40 natural zeolites are known (Tschernich, 1992). Most zeolites known to occur in nature are of lower Si/Al ratios, since organic structure-directing agents necessary for formation of siliceous zeolites are absent. Sometimes natural zeolites are found as large single crystals, though are very difficult to make in the laboratory. The catalytic activity of natural zeolites is limited by their impurities and low surface areas. However, interests in natural zeolites shifted towards zeolite synthesis and synthetic materials, as they offered a series of advantages such as wider versatility, more open frameworks( for adsorption and catalysis),and quality in constitution and chemistry. As a result, research on natural zeolites, was mainly devoted to ion exchange process which was discovered around 1850 (Thompson, 1850; Way, 1850). Few years later, Eichhorn observed that chabazite and natrolite behaved as reversible ion exchangers. In the early decades of the 20th century, ion exchange selectivity of a variety of zeolites for peculiar cations, e.g., ammonium was performed (Barrer, 1950) and starting from the end of the 1950s, found uses in various sectors of environmental relevance, e.g., treatment of wastewaters and soil rebuilding and remediation. The most recent frontier in the application of natural zeolites is in the field of life sciences. One of the drawbacks of natural zeolite research for application purposes is due to the limited availability of zeolite as it is a precious mineral, compared to the synthetic counterparts which could be mass produced at a lower cost (Colella, 2005). 2.1.1 Formation The pathway of natural zeolite formation is similar to the laboratory synthesis of zeolite. Zeolite nucleation, crystallisation and crystal growth take place as a result of slow to fast cooling of warm to hot magmas(of volcanic origin), which are basic, oversaturated in silicate and aluminate species and contain alkaline and/or alkali-earth cations. hot fluid + volcanic ash oversaturated basic magma zeolite crystals {solution + gel) The magma is obtained via hydrolysis of the original glassy material and is responsible for the tetrahedral coordination of aluminium and together with silicon. The main factors responsible for the structural formation are temperature, chemistry of the ash and the chemical composition of the resulting solution. Gel is formed along the process but is however not directly connected to nucleation and growth, as there is evidence that zeolite nuclei form from the oversaturated solution at the glass shards / solution interface (Aiello et al., 1980). Temperature and time are two factors which differentiate natural zeolitisation from laboratory synthesis. 2.1.2 Physico-chemical properties i.Cation exchange: The ion exchange properties of natural zeolites depend on their chemistry which ismainly in terms of selectivity. Selectivity depends on the framework topology, ion size and shape, charge density on the anionic framework, ion valence and electrolyte concentration in the aqueous phase (Barrer et al., 1978). ii.Reactions with alkalis: Oncein alkaline environments, zeolites become unstable as they tend to transform, similarlyto glassy systems, into more stable phases, usually into other framework silicates (Goto and Sand, 1988). The interaction of zeolite-rich materials with Ca(OH)2 give rise to calcium silicates and aluminates, which upon hydration are able to harden in both aerial and aqueous environments. This behaviour makes them to be known as pozzolanic materials Thermal properties: Heating of zeolite powder induces physical and chemical changes, which have been shown to include water loss (which causes expansion on heating), decomposition and gas evolution, phase transition, structure breakdown, re-crystallisation, melting etc (Colella, 1998). This property enables zeolite tuff stones to display good sound-proofing and heat insulation and serve as good building materials. Depending on zeolite nature, chemical composition and rock constitution, the tuff expands as a result of quick heating at temperatures of 1250 °C or above, inadvertently followed by a rapid quenching to room temperature. 2.2 SYNTHETIC ZEOLITES Early work could be traced back to the claimed synthesis of levynite by St Claire Deville in 1862 as there were no reliable methods for fully identifying and characterising the products. The origin of zeolite synthesis however, evolved from the work of Richard Barrer and Robert Milton which commenced in the late 1940s. The first synthetic zeolite unknown as a natural mineral later found to have the KFI structure (Baerlocher et al., 2001 ) was discovered by Barrer when investigating the conversion of known mineral phases under the action of strong salt solutions at fairly high temperatures (ca. 170-270  °C). Robert Milton was the first person to use freshly precipitated aluminosilicate gels to carry out reactions under milder conditions. This led to the discovery of zeolites A and X (Milton et al., 1989). Initially, the synthesis of zeolites required the use of only inorganic reactants but was however expanded in 1961 to include quaternary ammonium cations leading to the discovery o f silica-rich phases (high-silica zeolites). Subsequently, more synthetic zeolites have been discovered (Baerlocher et al., 2001), as well as zeolite-like or zeolite-related materials (Szostak, 1989) known as zeotypes- represented by microporous alumino- and gallo phosphates (AlPO4s and GaPO4s) and titanosilicates. Studies on understanding zeolite synthesis have continued to be carried out upto the present day (Table 1). This has been due to discoveries of new materials, advances in synthetic procedures, innovations in theoretical modelling methods and, especially, by the development of new techniques for the investigation of reaction mechanisms and the characterisation of products. Table 1: Evolution of materials development in the zeolite field ‘‘Low Si/Al zeolites (1-1.5) A, X ‘‘Intermediate Si/Al zeolites (f2-5) A) Natural zeolites: erionite, chabazite, clinoptilolite, Mordenite Synthetic zeolites: Y, L, large-pore mordenite, omega ‘‘High Si/Al zeolites (ËÅ"10-100) By thermochemical framework modification: highly silicious variants of Y, mordenite, erionite By direct synthesis: ZSM-5, Silicate Silica molecular sieves silicalite Source: Flanigen (1980) 2.2.1 Mechanism of Hydrothermal Synthesis Experimental observations of a typical hydrothermal zeolite synthesis Due to its chemical reactivity and low cost, amorphous and oxide-like Si and Al which make up the microporous framework are mixed with a cation source usually, in a basic water-based medium. The resulting aqueous mixture is then heated in a sealed autoclave at above 100ËšC allowing the reactants to remain amorphous for sometime (induction period) after which crystalline zeolites are detected (Figure 2). Gradually, an approximately equal mass of zeolite crystals which is recovered by filtration, washing and drying replaces all the amorphous materials (Cundy and Cox, 2005).The bond type created in the crystalline zeolite product (e.g. zeolite A or ZSM-5) which contains Si-O-Al linkages is similar to that present in its precursor oxides, therefore the enthalpy change is not great. This process reduces nucleation rates, thereby forming larger crystals. Reactivity of the gel, temperature and pH affect the rate of zeolite formation as an increase in pH and temperature leads to increase in the rate of formation of zeolite crystals. In their mother liquors, the zeolitic phases are metastable, thereby transforming the initial zeolite into an undesired thermodynamically more stable phase (Ullmann, 2002). 2.2.3 Synthesis from Clay minerals Kaolin and metakaolin (calcining kaolin at 500-700 °C) are two important clays used for the production of the zeolites NaA, NaX, and NaY (Breck, 1974; Barrer, 1978) because binder-free extrudates and granules which offer advantages in adsorption technology are produced. 2Al2Si2O5(OH)4 2Al2Si2O7+4H2O Kaolin Metakaolin Depending on the zeolite, the clay is shaped and, SiO2and seed crystals are added and while in the preformed shape, the zeolite crystallises. Alternatively, zeolite is formed when the binder component of metakaolin undergoes hydrothermal treatment with sodium hydroxide solution (Goytisolo et al., 1973; Chi and Hoffman, 1977). Using ultrasonic radiation, reaction rate is enhanced and there is energy saving and lower production cost due to lower temperatures. This process is less often used as it could cause odor of the product due to impurities present in clay e.g. iron 2.2.2 Industrial Zeolite Synthesis Zeolite synthesis is an extremely broad area of research and due to differences in the preparation of each zeolite type, two representative zeolite types, TPA-ZSM-5 and zeolite Na-A, are chosen for a more detailed presentation of the synthesis {Table 2} (Jansen, 2001). Table 2: Synthesis mixtures, physical chemical properties of the representative zeolites Molar oxide ratio Na-A TPA-ZSM-5 SiO2 1 1 Al2O3 0.5 Na2O 1 0.16 H2O 17 49 TPA2O 0.3 T (ËšC) > 150 Physical Chemical properties Pore arrangements 3D, cages connected via windows 2D, intersecting channels Bronsted activity low High Affinity hydrophilic Hydrophobic Pore volume (cm3/g) 0.37 0.18 Source: Jansen (2001) The composition of zeolite product can be expressed by the cation type and its overall Si/Al ratio. In the preparation of zeolite, nucleation is the rate determining step which is influenced by a range of factors dependent on the temperature of the reaction mixture. Low Temperature Reaction Mixture: Here, the reaction mixture is prepared at low temperature, At high pH, condensation occurs when the nucleophilic deprotonated silanol group on monomeric neutral species is attacked (Figure 5). The acidity of the silanol group depends on the number and type of substituents on the silicon-atom (Jansen, 2001). Temperature raise of the reaction mixture from High Temperature Reaction Mixture: At this temperature, zeolites are formed from amorphous material which involves, reorganisation of the low temperature synthesis mixture, nucleation and precipitation (crystallisation). During the induction period, gel and species in solution rearrange from a continuous changing phase of monomers and clusters which disappears through hydrolysis and condensation, in which nucleation occurs (Jansen, 2001). The process particles become stable and nuclei forms, followed by crystallisation which could occur in metastable solid, highly dispersed or dense gel forms. Product quality, reaction time and yield influence efficient production of zeolites by optimising their composition. 2.2.2 Secondary Synthesis Methods Catalytic or adsorbent properties that cannot be achieved by direct synthesis utilise post-synthesis (secondary) treatments to increase catalytic activity, shape selectivity or porosity and thermal/hydrothermal stability. Dealumination and ion exchange are used to carry out these modifications. Dealumination The zeolite structure is selectively dealuminated by acid solutions, washing out aluminium out of the crystal, as was observed for zeolite A. However, for higher silica containing materials (clinoptilolite), a fully decationated structure is produced after continuous acid treatment. The metal ion is replaced with H3O+ followed by (Al+3 + H3O+) removal, generating a hydroxyl nest. Aluminium is removed from the framework but not the crystal by hydrothermal dealumination. The heterogeneity in the concentration of the framework and non-framework of aluminium depends on the type of modification used. Hydrothermal treatment causes the amorphous aluminium to collect on the crystal surface which through fluorosilicate treatment can reduce aluminium centred acid sites. Often, a secondary pore system is generated and hydroxyl nests can be annealed. In order to enhance the catalytic properties as well as stability, silicon, aluminium and other metal ions are introduced into the framework (Szostak, 2001). Other methods of producing thermally and hydrothermally stable cracking catalysts include: use of EDTA, SiCl4 vapor, and (NH4)2SiF6. Acid mediated dealumination process via aluminium extraction and generation of hydroxyl nest (Szostak, 2001) Ion Exchange This is an important technique in pore-size engineering for the production of zeolitic adsorbents (Breck, 1974). Ion exchange used in the production of Brà ¸nsted acid sites has major importance in the synthesis of solid acid catalysts (Ullmann, 2002). Ion exchange can be achieved also, for certain intermediate-silica and high-silica zeolites (e.g., mordenite) by treatment with mineral acids although involves the risk of dealuminating the zeolite framework (McDaniel and Maher, 1976). An indirect route via an ion exchange with ammonium salt solutions must be followed, producing the â€Å"ammonium form† calcined at ca. 400 °C to liberate ammonia and give the hydrogen form (Ullmann, 2002). When cations to be exchanged are positioned inaccessible cages, a sieve effect is produced. pH is an important factor in ion exchanging of highly charged transition metal ions in order to prevent metal hydroxide precipitation especially at low pH. 2.3 CHARACTERISATION OF ZEOLITES In order to determine the relationships between the physical and physicochemical as well as sorptive and catalytic properties of zeolites, it is important to know the structural, chemical and catalytic characteristics of zeolites. Several standard techniques are employed in zeolite characterisation. The most common of which is X-ray diffraction used in determining the structure and purity of zeolites. Others include: x-ray fluorescence spectroscopy (XRF) or atomic absorption spectrometry, used to analyze elemental composition, sorption analysis to study the pore system, IR-spectroscopy, typically using adsorbed probe molecules to characterize the acid sites, scanning electron microscopy (SEM), for determining the size and morphology of zeolite crystallites, high-resolution transmission electron microscopy (HRTEM), nuclear magnetic resonance (NMR) spectroscopy, temperature programme desorption (TPD) and many others (Schà ¼th, 2005). 3.0 GENERAL APPLICATIONS OF ZEOLITES Zeolites are used primarily in 3 major applications: ion-exchange, adsorbents, and catalysts. Natural zeolites play an important role in bulk mineral applications. Adsorbent applications: Common adsorbent applications focus on removal of small polar molecules and bulk separations, by more aluminous zeolites and based on molecular sieving processes respectively (Table 3). Table 3: Zeolite commercial applications as adsorbents Purification Bulk separations Drying: natural gas (including LNG), cracking gas (ethylene plants), refrigerant Normal/iso-paraffin separation, Xylene separation CO2 removal: natural gas, flue gas (CO2 + N2) cryogenic air separation plants Olefin separation, Separation of organic solvents Pollution abatement: removal of Hg, NOx, SO Separation of amino acids, n-nitrosoamines Sweetening of natural gas and liquefied petroleum gas Separation of CO2, SO2, NH3 Source: Flanigen (1980). Catalyst applications: Zeolites have the greatest use in catalytic cracking. They also play a role in hydroisomerisation, hydrocracking and aromatics processing. The strong acidity of zeolites plays a role in hydrocarbon processing. Asides this, they are finding increasing use in synthesis of fine chemicals and organic intermediates in isomerisation reactions, nucleophilic substitution and addition etc. Table 4: Zeolite applications in Catalysis Inorganic reactions: H2S oxidation, NO reduction of NH3, CO oxidation, reduction Hydrocarbon conversion: Alkylation, Cracking Organic reactions: Aromatization (C4 hydrocarbons), Aromatics (disproportionation, hydroalkylation, hydrogenation, hydroxylation, nitration, etc.) Dehydration Epoxidation Beckman rearrangement (cyclohexanone to caprolactam) Methanol to gasoline Chlorofluorocarbon decomposition Shape-selective reforming Source: Flanigen (1980); Galarneau et al (2001). Ion-exchange applications: Zeolite properties are directly exploited in several applications such as in the detergent industry, where zeolites are used for water softening or ‘building, animal food supplementation and in the treatment of wastewater (Townsend and Coker, 2001). Zeolite A has selectivity for Ca2+, thereby providing a unique advantage. Also, natural zeolites can be used to remove of Cs+ and Sr 2+radioisotopes through ion-exchange (Payra and Dutta, 2003). Table 5: Applications and advantages of Ion-exchange Applications Advantage Metals removal and recovery High selectivities for various metals Removal of Cs+ and Sr2+ Stable to ionizing radiation Detergent builder zeolite A, zeolite X (ZB-100, ZB-300) Remove Ca2+ and Mg2+ by selective exchange, no environmental problem Ion exchange fertilizers Exchange with plant nutrients such as NH4+ and K+ with slow release in soil Source: Flanigen (1980) Other Applications: Zeolites also play important roles in health-related applications (such as antibacterial agents, vaccine adjuvants, drug delivery, bone formation, biosensors and enzyme mimetics), oil refining, and petrochemical processes. Zeolite powders are used for odor removal and as plastic additives. Zeolitic membranes offer the possibility of organic transformations and separations coupled into one unit (Payra and Dutta, 2003). 3.1 ZEOLITES AND THE ENVIRONMENT Nearly all applications of zeolites are driven by environmental concerns, from cleaning toxic (nuclear) wastes, to treatment of wastewater, thereby reducing pollution. Zeolites have now been used to replace harmful phosphate builders in powder detergents due to water pollution risks. Zeolite catalysts help to save energy as they make chemical processes more efficient, minimising un-necessary waste and by-products. When used as solid catalysts and redox catalysts/sorbents, they reduce the need for corrosive liquid acids and remove atmospheric pollutants, (such as engine exhaust gases and ozone-depleting CFCs) respectively (Bell, 2001). In wastewater, zeolites (clinoptilolite, mordenite) are used to remove ammonia and ammonium ions (Townsend and Coker, 2001), as well as heavy metal cations and transition metals. 3.2 ZEOLITE CATALYSTS IN GREEN CHEMISTRY Zeolite catalysts have contributed to the design and synthesis of novel materials and development of new methodologies in organic synthesis, displacing the conventional and waste generating reagents thereby maximising atom utilization and reducing waste generated (E-factor). Zeolites play an important role in acid-catalyzed reactions such as acylation, alkylation, isomerisation and condensation, cyclisation and electrophilic aromatic substitution. Acylation of aromatic substrates: used in fine chemicals manufacture although has proven unsuccessful in less reactive aromatic compounds due to adsorption imbalance, unless performed in vapor phase using H-ZSM-5 (Singh and Pandey, 1997). 4.0 CONCLUSION Due to the role zeolites play mainly as catalysts in the environment as well as in chemical industry, the efficiency of the zeolite catalysts has been greatly improved. The yield and selectivity of the zeolite process is quantitative and in addition, reduces energy requirements, capital costs and complexity of equipments. Over the years, the synthesis process of zeolites have encompassed the principles of green chemistry as described in the report which has included waste prevention, energy efficiency, fewer environmental impacts, safer solvents, renewable materials, process intensification, catalysis and reduction in capital cost. Though present techniques seem to apply some of the principles of green chemistry, further research is still being employed to improve the overall process. 3.0 REFERENCES Aiello, R., Colella, C., Casey, D. G. and Sand, L.B. 1980. In L.V.C. Rees, ed. Proc. 5th Int. Conf. on Zeolites. Heyden Son, London, U.K. pp. 49. Armor, J. N. Applied Catalysis A: 189 (1999) 153-162. Baerlocher, C., Meier, W.M., Holson, D. 2001. Atlas of Zeolite Framework Types. 5th ed. Amsterdam: Elsevier. Barrer, R. M. 1978.Zeolite and Clay Minerals as Sorbents and Molecular Sieves. Academic Press, London. Barrer, R.M. 1978. In L.B. Sand and F.A. Mumpton, eds. Natural Zeolites. Occurrence, Properties, Use. Pergamon Press, Elmsford, NY. pp. 385. Barrer, R.M. 1982. Hydrothermal Chemistry of Zeolites; Academic Press: London. Barrer, R.M. J. Chem. Soc. (1950) 2342. Bell, R.G. 2001. Zeolites. [Online]Available at http://www.bza.org/zeolites.html. [Accessed 1 May 2010]. Breck, D.W. 1974. Zeolite Molecular Sieves. New York: Wiley. Colella, C. 1998. In J. Ma. Rincon and M. Romero, eds. Characterization Techniques of Glasses and Ceramics. Springer-Verlag, Berlin Heidelberg, Germany. pp. 112. Colella, C. 2005. Natural zeolites. In J. Cejka and H. van Bekkum, eds.Stud Surf Sci Catal 157. Cundy, C. S., Cox, P. A. 2003 .The Hydrothermal Synthesis of Zeolites: History and Development from the Earliest Days to the Present Time. Chem. Rev.103, pp.663-701. Cundy, C.S. and Cox, P.A. 2005. The hydrothermal synthesis of zeolites: Precursors, intermediates and reaction mechanism. Microporous and Mesoporous Materials. 82, 1-78. Damour, A., Hebd, C. R. Seances Acad. Sci. 44 (1857), pp. 975; also Ann. Chim. Phys., 3rd series, 53 (1858), pp. 438 (in French). De Gennaro, M., Colella, C., Franco, E. and Stanzione, D. Neues Jahrb. Mineral.-Mon.hefte. H.4(1988)149. Flanigen, E.M. 1980. Pure Appl Chem 52:2191-2211. Galarneau, A., Di Renzo, F., Fajula, F., Vedrine, J. eds., 2001. Zeolites and Mesoporous Materials at the Dawn of the 21st Century. Stud Surf Sci Catal 135. Goto and L.B. Sand. 1988. In D. Kallo and H.S. Sherry, eds. Occurrence, Properties and Utilisations of Natural Zeolites. Akademiai Kiado, Budapest, Hungary. pp. 161. Jansen, J.C. 2001. The preparation of oxide molecular sieves: synthesis of zeolites. In H. Van Bekkum, E.M. Flanigen, P.A. Jacobs, J.C. Jansen, eds. Introduction to zeolite science and practice.2nd ed. Stud Surf Sci Catal 137. Lancaster, M. 2002. Green Chemistry: an introductory text. Cambridge: Royal society of chemistry. Ch.4. McDaniel, C.V., Maher, P.K. In J. A. Rabo, ed. Zeolite Chemistry and Catalysis. ACS Monogr.171(1976) pp.285 Milton, R.M. In M.L. Occelli, H.E. Robson, eds. Zeolite Synthesis. ACS Symp. Ser. 398 (1989) pp.1 Payra, P., Dutta, P.K. 2003. Zeolites: A Primer. In S.M. Auerbach, K. Carrado, P.K. Dutta, eds. Handbook of zeolite science and technology.New York: Marcel Dekker Inc. Ch.1. Schà ¼th, F. 2005. In J. Cejka and H. van Bekkum, eds. High-throughput experiments for synthesis and applications of zeolites. Stud Surf Sci Catal 157. Sheldon, R.A. 2000. A special topic issue on green chemistry: Atom efficiency and catalysis in organic synthesis. Pure Appl. Chem., 72(7), pp. 1233-1246. Singh, A. P., Pandey, A. K. J. Mol. Catal. A: Chemical 123(1997), 141 Szostak, R. 1989. Molecular Sieves Principles of Synthesis and Identification. 2nd Edition: Van Nostrand Reinhold, New York, Blackie, London. Thompson, H.S. J. Royal Agric. Soc. Engl. 11 (1850), pp. 68. Townsend, R.P., Coker, E.N. 2001. Ion exchange in zeolites. In H. Van Bekkum, E.M. Flanigen, P.A. Jacobs, J.C. Jansen, eds. Introduction to zeolite science and practice. 2nd ed. Stud Surf Sci Catal 137. Tschernich, R.W. 1992. Zeolites of the World. Phoenix: Geoscience Press. Ullmann: Encyclopaedia of Industrial Chemistry. 2002. Zeolites. Wiley Interscience. W.R. Grace Co., DE2707313, 1977 (C. W. Chi, G. H. Hoffman). W.R. Grace Co., US3906076, 1973 (J. A. Goytisolo, D. D. Chi, H. Lee). Way, J.T. J. Royal Agric. Soc. Engl. 11 (1850), pp. 313.

The Repeating Island Essay -- Literary Analysis, Benintez-Rojo

In The Repeating Island, Antonio Benintez-Rojo writes on postindustrial societies inaccurate views of the Caribbean as a common archipelago and calls on postindustrial societies to reexamine their view of the Caribbean. In this paper the following topics in The Repeating Island will be examined in validating Benitez- Rojo’s perspective that the Caribbean is a meta-archipleago with no boundaries or center: Columbus’s machine to the sugar-making machine, the apocalypse to chaos, rhythm to polyrhythm, and literature to carnival. The first way Benitez-Rojo draws attention to his perspective is through his analysis on how the Atlantic became known as the Atlantic because of the presence of European slave plantations, piracy, servitude, and monopoly over the trades in the Caribbean. He refers to Christopher Columbus presence in Hispaniola as the starting point of â€Å"the machine† (Benitez- Rojo 5) that brought a wealth of goods from Hispaniola to Spain, who then spread its profitable practice to Cuba, Jamaica, and Puerto Rico at the expense of native people (6). After the Cape San Vicente disaster, where the Spanish lost treasure from French pirates, in 1565 Columbus’s machine expanded its conquests of gold, silver, and diamonds thus creating the fleet. The fleet not only helped the Spanish become wealthy, it made the Caribbean a meta-archipelago because of its presence in the waters of the Caribbean, Atlantic, and Pacific. Menendez de Aviles’s fleet proved successful in protecting gold and silver from pirate attacks through the use of Caribbean ports, forts, militia, and geography (8). In today’s Caribbean â€Å"the machine† is referred to as the plantation, which the Europeans controlled all aspects o... ...ted by it (23). Benitez-Rojo calls on a rereading of the Caribbean text and states once this is done, the result is the text showing the harmony of rhythms whose attempts to escape ‘in a certain kind of way’ (28). It is through carnaval the text can be seen in its most natural form, a meta-archipleago of everyday life. In The Repeating Island, Antonio Benintez-Rojo defends his perspective that the Caribbean is a meta-archipleago with no boundaries or center through his writing on Columbus’s machine to the sugar-making machine, the apocalypse to chaos, rhythm to polyrhythm, and literature to carnival. He debunks postindustrial society’s view of the Caribbean as a common archipelago by examining what makes the Caribbean, the Caribbean through its history and culture, which persuades the reader to reexamine the various writing on the Caribbean.

Cape It Syllabus

CARIBBEAN EXAMINATIONS COUNCIL Caribbean Advanced Proficiency Examination Correspondence related to the syllabus should be addressed to: The Pro-Registrar Caribbean Examinations Council Caenwood Centre 37 Arnold Road, Kingston 5, Jamaica, W. I. Telephone Number: (876) 920-6714 Facsimile Number: (876) 967-4972 E-mail address: [email  protected] org Website: www. cxc. org Copyright  © 2008 by Caribbean Examinations Council The Garrison, St. Michael 11158 Barbados This document CXC A4/U2/08 replaces CXC A4/U1/01 issued in 2001.Please note that the syllabus was revised and amendments are indicated by italics and vertical lines. First Issued 1998 Revised 2001 Revised 2008 Please check the website www. cxc. org for updates on CXC’s syllabuses. RATIONALE1 AIMS 2 SKILLS AND ABILITIES TO BE ASSESSED2 PRE-REQUISITES OF THE SYLLABUS3 STRUCTURE OF THE SYLLABUS4 UNIT 1: INFORMATION TECHNOLOGY THEORY MODULE 1: FUNDAMENTALS OF INFORMATION TECHNOLOGY5 MODULE 2: INFORMATION TECHNOLOGY SYST EMS9 MODULE 3: INFORMATION AND PROBLEM-SOLVING13 UNIT 2: APPLICATION AND IMPLICATIONMODULE 1: INFORMATION MANAGEMENT16 MODULE 2: USE OF INFORMATION TECHNOLOGY TOOLS19 MODULE 3: SOCIAL, ORGANIZATIONAL AND PERSONAL ISSUES22 OUTLINE OF ASSESSMENT25 REGULATIONS FOR PRIVATE CANDIDATES31 REGULATIONS FOR RESIT CANDIDATES31 ASSESSMENT GRID32 GLOSSARY33 T he Caribbean Advanced Proficiency Examination (CAPE) are designed to provide certification of the academic, vocational and technical achievement of students in the Caribbean who, having completed a minimum of five years of secondary education, wish to further their studies. The examinations ddress the skills and knowledge acquired by students under a flexible and articulated system where subjects are organised in 1-Unit or 2-Unit courses with each Unit containing three Modules. Subjects examined under CAPE may be studied concurrently or singly, or may be combined with subjects examined by other examination boards or institutions. The Caribb ean Examinations Council offers three types of certification. The first is the award of a certificate showing each CAPE Unit completed. The second is the CAPE diploma, awarded to candidates who have satisfactorily completed at least six Units, including Caribbean Studies.The third is the CAPE Associate Degree, awarded for the satisfactory completion of a prescribed cluster of seven CAPE Units including Caribbean Studies and Communication Studies. For the CAPE diploma and the CAPE Associate Degree, candidates must complete the cluster of required Units within a maximum period of five years. Recognized educational institutions presenting candidates for CAPE towards the award of the Council’s Associate Degree in nine categories must, on registering these candidates at the start of the qualifying year, have them confirm in the required form, the Associate Degree they wish to be awarded.Candidates will not be awarded any possible alternatives for which they did not apply. ? RATION ALE The Information Technology Syllabus for the Caribbean Advanced Proficiency Examination (CAPE) reflects the belief that Information Technology is essential to the economic and social development of the region. The widespread use of Information Technology, the tools and techniques for inputting, processing, storing, outputting, transmitting and receiving information, which was made possible because of improvements in computer and telecommunications technology, has significantly changed society.A large proportion of business transactions is now performed over computer networks. The Internet and multimedia computers have had a significant impact on the ways in which people work, learn, communicate, conduct business, and on the ways they seek entertainment. The increased integration of computer and telecommunications technology has led to an increased globalisation of the world economy. It is now possible to use a telephone line to transfer information between computers located anywh ere in the world.Moreover, as the world becomes familiar with the potential of Information Technology, people are beginning to realise that many problems and situations which were hitherto thought of as primarily involving physical activities, in fact rely for their solution on the ready availability of relevant information. In order for the Caribbean to participate in and contribute to this new world, it is essential that Caribbean people become familiar with this technology.This not only implies that we must know how to use the technology from a purely technical point of view; but also means that we must be conscious of the impact of Information Technology. In particular, we must be made aware that the appropriate use of Information Technology can help solve the problems that we are facing in their daily lives, whether they be of an economic, social or personal nature, and that Information Technology provides opportunities for economic development, as well as for further integrati on, of the region.However, the increased use of Information Technology also raises a number of ethical, legal and political issues, ranging from questions concerning privacy of information about individuals, to intellectual property rights. The introduction of Information Technology without careful consideration often worsens a problem, rather than solves it. Any decision to turn to Information Technology must, therefore, be preceded by a critical analysis of the strengths and weaknesses of the proposed solution. In addition, Information Technology has made access to information and misinformation far easier.It is, therefore, crucial that anyone, before using any information, first critically evaluate its reliability. ? AIMS The syllabus aims to: 1. develop an awareness of the importance of information in the solution of many problems; 2. develop a critical attitude to gathering, processing and evaluating information; 3. develop a broad understanding of hardware, software, networks, databases and information systems and their uses; 4. sensitize students to the use of Information Technology in conducting and living their daily lives; 5. evelop an awareness of the power and pitfalls of Information Technology; 6. develop an awareness of the ethical, legal and political considerations associated with information technology; 7. assist students in solving real-life problems, using the tools and techniques of the computer and computer-related technologies; 8. encourage students to use information sources and services to retrieve, interpret and communicate information; 9. develop a positive attitude to new and emerging technologies in Information Technology. ? SKILLS AND ABILITIES TO BE ASSESSEDThe skills that students are expected to have developed on completion of this syllabus have been grouped under three headings: 1. Knowledge and Comprehension; 2. Application and Analysis; 3. Synthesis and Evaluation. Knowledge and Comprehension The ability to: | |- recall and g rasp the meaning of basic facts, concepts and principles of Information Technology; | | |- identify real-life problems for which Information Technology solutions are appropriate and beneficial. | Application and Analysis The ability to: |- use facts, concepts, principles and procedures in unfamiliar situations; | | |- interpret and present data and draw logical conclusions about Information Technology issues; | | |- identify and recognize the relationships between the various components of Information Technology and their impact on society; | | |- recognize the limitations and assumptions of data gathered in an attempt to solve a problem. | Synthesis and EvaluationThe ability to: | |- make reasoned judgements and recommendations based on the value of ideas and information and their implications; | | |- use the computer and computer-based tools to solve problems; | | |- justify and apply appropriate techniques to the principles of problem-solving. | | | | ? PRE-REQUISITES OF THE S YLLABUSAny person with a good grasp of the Caribbean Secondary Education Certificate (CSEC) Information Technology Syllabus, or its equivalent, should be able to pursue the course of study defined by this syllabus. However, successful participation in the course of study will also depend on the possession of good verbal and written communication skills. ? STRUCTURE OF THE SYLLABUS This syllabus is arranged into TWO Units, each made up of three Modules. Whilst each Module in each Unit is independent, together they form a coherent course of study which should prepare candidates for the world of work and studies at the tertiary level.UNIT 1: INFORMATION TECHNOLOGY THEORY Module 1-Fundamentals of Information Technology Module 2-Information Technology Systems Module 3-Information and Problem-Solving UNIT 2: APPLICATION AND IMPLICATION Module 1-Information Management Module 2-Use of Information Technology Tools Module 3-Social, Organizational and Personal Issues In order to be successful, students should spend at least 50 hours of the 150 hours per Unit in a computer lab or on a computer at home or in the workplace. UNIT 1: INFORMATION TECHNOLOGY THEORY MODULE 1: FUNDAMENTALS OF INFORMATION TECHNOLOGY GENERAL OBJECTIVES On completion of this Module, students should: 1. develop an understanding of how Information Technology (IT) relates to other disciplines in Computing; 2. develop an understanding and appreciation of data and information, and the distinction between them; 3. develop an understanding of the nature and sources of information; 4. develop an understanding and appreciation of Information Technology and its history. SPECIFIC OBJECTIVES | |CONTENT | | | | | |Students should be able to: | | | | | |explain the concept of Information Technology; | |Definition and scope of Information Technology; application of tools for | | | |informational purposes. | | | | | |describe the relationship between Information Technology and | |Computing, Computer Science, So ftware Engineering, Computer Engineering, | |other disciplines in Computing; | |and Information Systems; commonalities and differences between | | | |disciplines. | | | | |explain the characteristics of data and information; | |Definition of terms; examples. | | | |Data: include unprocessed, unorganised and discrete (in separate, | | | |unrelated chunks), qualitative (opinion-based, subjective) or quantitative| | | |(measurement-based, objective), detailed or sampled. | | | | | | |Information: including distortion, disguise, reliability, inconsistency, | | | |incomprehensibility, subject to interpretation, value, relevance, | | | |confidentiality, timeliness, completeness, security, shareability, | | | |availability, lifespan, information as a commodity, format and medium; | | | |Nature and structure of information: strategic, tactical, operational; | | | |structured, semi-structured and unstructured. | | | | | | | | | | | | | | | | | UNIT 1 | |MODULE 1: FUNDAMENTAL S OF INFORMATION TECHNOLOGY (cont’d) | | | |SPECIFIC OBJECTIVES | |CONTENT | | | | | |Students should be able to: | | | |distinguish among data, information and knowledge; | | Differences among data, information and knowledge. | | | | |explain information processing; | | | | | |Definition of information processing (input process, output process); | | | |manual versus automated information processing; components of manual | | | |information processing: collect, collate, analyze, present and | | | |disseminate; components of automated information processing: input (data | | | |capture or entry), process (for example, analyze, sort, calculate), store,| | | |retrieve, output (present and disseminate); transmit data and information. | | | |Interrelationship between data and information through information | | | |processing. | | | | | | |Types of manual and automated information systems. | | | | | |discuss the importance of data and information; | |Use of information in decision making: data quality; appropriateness of | | | |data. Nature and structure of information: strategic, tactical, | | | |operational; structured, semi-structured and unstructured. | | |identify ways of representing data and information; | |Data: including character, string, numeric, aural (for example, Morse | | | |Code, musical notes), visual (for example, the individual frames of a | | | |movie, fingerprints); musical symbols. | | | | | | | |Information: including text, graphics, sound, video, special purpose | | | |notations (mathematical, scientific and musical notations); graphical | | | |representations (graphs and charts); tables. | | | | |discuss various types of information sources; | |Types of information sources: including books, journals, catalogs, | | | |magazines, newspapers, online libraries, CD-ROMs, DVDs, electronic | | | |databases, web sites, people, blogs, wikis; advantages, disadvantages of | | | |information sources. | | | | | UNIT 1 | |MODULE 1: FUNDAMENTALS OF INFORMATION TECHNOLOGY (cont’d) | | | | | |SPECIFIC OBJECTIVES | |CONTENT | | | | | |Students should be able to: | | | |identify characteristics of information sources; | |Include availability, cost, currency of information, amount of detail | | | |(depth), breadth of coverage, reliability, format and medium. | | | | |identify tools used in the entry, retrieval, processing, | |Examples of hardware, software, and communication tools. Tools associated| |storage, presentation, transmission and dissemination of | |with the Internet including on-line services; search engines; Usenet, | |information; | |Internet Relay Chat (IRC), telnet, ftp, newsgroups, message board, mailing| | | |list, Internet telephony. | | | | |justify the tools used in Information Technology; | |Hardware, software and communication tool used in the entry, retrieval, | | | |processing, storage, presentation, transmission and dissemination of | | | |information; advantages a nd disadvantages. | | | | | |outline the history of Information Technology; | |Brief history of computer hardware and software, Internet and | | | |telecommunications; categories by size, cost, and processing ability. | | | | |explain the meaning of terms related to telecommunication. | |Transmission media, channels, receivers, senders, modulation, bandwidth; | | | |telecommuting. | Suggested Teaching and Learning Activities To facilitate students’ attainment of the objectives of this Module, teachers are advised to engage students in the teaching and learning activities listed below. 1. Use the Internet to source relevant material. 2. Compile a glossary of terms using the Internet, computer magazines, textbooks and other information sources. This could form the basis of an in-class discussion. 3.Develop and use diagrams to represent the concepts and relationships contained in the Specific Objectives. 4. Invite resource persons with experience in the innovative use of Inf ormation Technology in fields, such as business and entertainment, to speak on relevant issues. 5. Develop manual filing system and compare functions, such as retrieval and sorting, with automated information system. UNIT 1 MODULE 1: FUNDAMENTALS OF INFORMATION TECHNOLOGY (cont’d) RESOURCES |Daley, B. |Computers are your Future, New Jersey: Pearson Prentice Hall, 2007. | | | | |Heathcote, P. A Level Computing, Letts, London: Letts, 2005. | | | | |Long, L. and Long, N. |Computers: Information Technology in Perspective, New Jersey: | | |Prentice Hall, 2004. | | | | |Parson, J. and Oja, D. |Computer Concepts, New York: International Thompson Publishing | | |Company, 2007. | | | |Shelly, G. , Cashman, T. , and Vermaat, M. |Discovering Computers, New York: International Thompson Publishing | | |Company, 2008. | UNIT 1 MODULE 2: INFORMATION TECHNOLOGY SYSTEMS GENERAL OBJECTIVES On completion of this Module, students should: 1. develop an understanding of the components o f Information Technology Systems; 2. develop an appreciation for human computer interaction (HCI); 3. develop an awareness of security measures associated with information technology systems; 4. develop an awareness of the structure of the World Wide Web and its standards and protocols. SPECIFIC OBJECTIVES | |CONTENT | | | | | |Students should be able to: | | | | | |describe Information Technology Systems; | |Definition; types of Information Technology Systems; examples. | | | | | |identify the components of an Information Technology | |Hardware, software, network, users: end-users and IT professionals; definitions | |System; | |and examples. | | | | |describe the purpose and functions of hardware | |Purpose, functions and types of hardware including input, output, storage, | |components; | |processor and peripheral devices; definitions and examples; interaction between | | | |hardware components. | | | | | describe the purpose and functions of software | |Purpose, functions and types of software including application, system (operating| |components; | |systems, language translators, and utilities); proprietary versus open source | | | |software; information systems including embedded systems: monitoring and control | | | |systems; data processing systems; management information systems, decision | | | |support systems, executive information systems; expert systems, data warehouses; | | | |definitions and examples; major input and output from each type of information | | | |system, such as data, information, processed transactions, reports including | | | |detailed, summarised, exception, ad hoc. | | | | |explain the various stages of the system development | |Including feasibility study, analysis, design, development, implementation, | |life cycle (SDLC), and software engineering; | |review; deliverables/output of each stage including system proposal, project | | | |plan, various diagrams and charts, information system (software) test plans, | | | |conversion plans, documentation including user and technical manuals. | | | | |UNIT 1 | |MODULE 2: INFORMATION TECHNOLOGY SYSTEMS (cont’d) | |SPECIFIC OBJECTIVES | |CONTENT | | | | | |Students should be able to: | | | | | | |discuss the tools used in the different stages of the | |Including questionnaires, interviews, observation, review/investigation of | |(SDLC); | |printed material, ER diagrams, data flow diagrams, process models, object models,| | | |decision tables and trees, computer-aided software engineering (CASE) tools, | | | |GHANT charts, prototypes, flowcharts, pseudocode, programming languages. | | | | |describe the purpose and functions of network | |Purpose, functions and types of networks including local area network (LAN), wide| |components; | |area network (WAN), metropolitan area network (MAN); virtual private network | | | |(VPN); Internet; Intranet; Extranet; configuration; topologies; transmission | | | |media: (wired versus wireless): fibr e-optic, Unshielded Twisted Pair (UTP); | | | |hotspots, protocols; definitions and examples; network security; firewalls. | | | | |explain the roles of users; | |Inclusion of IT professionals, end users: expert users, novice users; definitions| | | |and examples. | | | | | |compare the various features associated with the | |Features including, speed, efficiency, portability, maintainability, storage, | |components of Information Technology Systems; | |transmission. | | | | | |describe the interrelationship etween the components in| |Relationship between the components: hardware, software, network, user. | |an Information Technology System; | | | | | | | |describe different types of HCI; | |Types of HCI including forms, menu, command line, natural language, graphical | | | |user interface (GUI), speech and direct manipulation. | | | | |distinguish between different types of HCI; | |Types of HCI including forms, menu, command line, natural language, graphical | | | |user in terface (GUI), speech and direct manipulation. | | | | | |describe ways in which a user’s characteristics require | |For example, age, education, differently abled and cultural differences, | |adaptation of a user interface to increase | |non-visual interfaces, sensors, accessibility features; differences. |effectiveness; | | | | | | | |UNIT 1 | |MODULE 2: INFORMATION TECHNOLOGY SYSTEMS (cont’d) | | | | | |SPECIFIC OBJECTIVES | |CONTENT | | | | |Students should be able to: | | | |compare various security mechanisms; | |Physical access control versus logical access control measures and devices; | | | |including passwords (characteristics of an effective password- not obvious, | | | |length, mixed case, alphanumeric); authentication, encryption, swipe or key | | | |cards, biometric; data integrity. | | | | | |explain the meaning of terms related to the security of| |For example, data security, passwords, authentication, encryption, data | |Information Technology Systems; | |corruption. | | | | |describe the structure of the World Wide Web (WWW) as | |Hyperlinks, home page, web page versus web site; Hypertext Transfer Protocol | |interconnected hypertext documents; | |(HTTP), universal resource locator (URL), hypertext markup language (HTML), | | | |extensible markup language (XML); IP address versus domain name. | | | | | |discuss Internet standards. | |Hypertext Transfer Protocol (HTTP); Transfer Control Protocol/Internet Protocol | | | |(TCP/IP) in terms of specifications, guidelines, software and tools. | Suggested Teaching and Learning Activities To facilitate students’ attainment of the objectives of this Module, teachers are advised to engage students in the teaching and learning activities listed below. 1.Identify a user of a microcomputer system in an office environment and conduct an interview to ascertain which software tool is used by the user and why. Discuss specific features of the software that makes it suited to the given task. Determine if a more appropriate software tool could be used for the task, identify the software tool and explain why it is more appropriate. 2. Compile a glossary of terms using the Internet, computer magazines, textbooks and other information sources. This could form the basis of an in-class discussion. 3. Identify two examples of a HCI and make a presentation comparing and contrasting those interfaces. 4. Use the example of a person driving a car and interacting with the instruments on the dashboard as an opportunity to introduce HCI. UNIT 1MODULE 2: INFORMATION TECHNOLOGY SYSTEMS (cont’d) 5. Identify HCI used in different organizations (for example, restaurants, hospitals, recording studios, security firms, scientific labs) and by the student (for example, ipod, gaming consoles, cell phone, web pages) and evaluate these designs based on a set of identified criteria. 6. Develop and use diagrams to represent the concepts and relationships contained in the Spe cific Objectives. 7. Invite resource persons with experience in the innovative use of Information Technology in business to speak on relevant issues. RESOURCES |Daley, B. |Computers are your Future, New Jersey: Pearson Prentice Hall, 2007. | | | |Heathcote, P. |A Level Computing, Letts, London: Letts, 2005. | | | | |Long, L. and Long, N. |Computers: Information Technology in Perspective, New Jersey: | | |Prentice Hall, 2004. | | | | |Parson, J. and Oja, D. Computer Concepts, New York: International Thompson Publishing | | |Company, 2007. | | | | |Shelly, G. , Cashman, T. , and Vermaat, M. |Discovering Computers, New York: International Thompson Publishing | | |Company, 2008. | UNIT 1 MODULE 3: INFORMATION AND PROBLEM-SOLVING GENERAL OBJECTIVES On completion of this Module, students should: 1. develop the knowledge, skills and understanding of the problem-solving process; 2. develop an appreciation for the value and importance of information to solve problems. SPECIFIC OBJ ECTIVES | |CONTENT | | | | | |Students should be able to: | | | | | |explain the concept of problem-solving; | |Problem-solving as a process; finding solutions to a problem. | | | | |describe the stages of the problem-solving process; | |Stages: including define the problem, analyze the problem (using tools, such as | | | |questionnaires, interviews, observation, reviewing documents), identify and | | | |evaluate possible solutions, select and justify the optimal solution, implement, | | | |and review. | | | | | |describe the role of information in the solution of | |Identification of the information necessary for the solution of personal, | |real-life problems; | |commercial, scientific and social problems. Categorization of information as | | | |essential, desirable, extraneous or cosmetic in the solution of a problem. | | | | |explain how information can be used to solve real-life | |Criteria for rejecting or accepting a piece of information, including bias, | |problems ; | |accuracy, cultural context, completeness, currency of information, refereed and | | | |unrefereed sources, characteristics of information on the Internet. | | | | | |analyse the role of information in fulfilling the goals | |Information used in decision-making and problem-solving; capitalising on | |of an individual or organization; | |opportunities. | | | | |use data flow diagrams (DFD) to document the flow of | |Use of symbols for data stores, processing, data flow and external entities; | |information within an organization; | |context level DFD and first level detailed DFD. | | | | | |explain the concept of an algorithm; | |Definition; algorithm as a problem-solving strategy; its role and importance in | | | |the problem-solving process; properties of algorithm. | | | | |identify the necessary properties of ‘well designed’ | |Properties including a general solution to the problem in a finite number of | |algorithms; | |steps, clearly defined and unambiguo us, flow of control from one process to | | | |another. | UNIT 1 MODULE 3: INFORMATION AND PROBLEM-SOLVING (cont’d) |SPECIFIC OBJECTIVES | |CONTENT | | | | | |Students should e able to: | | | | | |identify ways of representing algorithms; | |Inclusion of narrative, flowcharts and pseudocode. | | | | | |develop algorithms to represent problem solution; | |Simple input, output, processing; control structures: sequence, selection, | | | |looping and iteration. | | | | |explain the concept of programming; | |Development of computer programs; stages in programme development; programming | | | |paradigms; examples of programming languages. | | | | | |outline the interrelationship(s) between algorithms and | |Algorithms as precursor to program development. | |programming. | | | Suggested Teaching and Learning Activities To facilitate students’ attainment of the objectives of this Module, teachers are advised to engage students in the teaching and learning activities listed below. 1.Conduct discussion leading to the definition of a problem to ascertain the students’ perspectives of the problem. Give feedback on the perspectives by identifying problems in different scenarios. For example, a farmer getting rid of a pest affecting his crop. 2. Emphasis should be placed on the fact that most if not all problems have an information component. For example, the information the farmer would need to get rid of the pest affecting his crop would be the type of pest, what are its natural enemies, what would be the effect on his crop of using a particular pesticide or a natural enemy of the pest. 3. Visit business places to observe how Information Technology is used to address problems faced by the organisation. 4.Invite professionals, artists, and others to make presentations to students to give additional perspectives on issues relevant to their studies. Encourage students to make presentations to persons outside of the school system, who can evalua te a comment on the presentations as well as answer the students’ questions. 5. Invite professionals, artists, and others to make presentations to students to give additional perspectives on issues relevant to their studies. Encourage students to make presentations to persons outside of the school system, who can evaluate a comment on the presentations as well as answer the students’ questions. UNIT 1 MODULE 3: INFORMATION AND PROBLEM-SOLVING (cont’d) 6.Choose a physical activity, such as a sport, to demonstrate how the use of information can be an effective tool or mechanism in ensuring a desired outcome, such as improved performance or success over competitors. 7. Develop a set of scenarios in which there are either opportunities or problems encountered by an organization. Students are required to (a) identify a problem, (b) formulate a problem statement, (c) suggest two possible solutions, and (d) recommend one of the solutions and justify the choice. 8. Adop t a single DFD notation style and have students complete several exercises to become familiar with that style, for example, Gane and Sarson. Present data flow diagramming errors and have students label these with the relevant terms.For example, black hole – process with only input data flow, a process with only output data flow from it; data stores or external entities that are connected directly to each other, in any combination; incorrectly labeling data flow or objects, some examples are: i) labels omitted from data flow or objects; ii) data flow labeled with a verb; iii) processes labeled with a noun. 9. Work in groups to address problem-solving through the development of algorithms and the use of pseudocode to solve those problems. This activity should ensure that all elements are practiced. RESOURCES |Daley, B. |Computers are your Future, New Jersey: Pearson Prentice Hall, 2007. | | | | |Heathcote, P. A Level Computing, Letts, London: Letts, 2005. | | | | |Long, L. and Long, N. |Computers: Information Technology in Perspective, New Jersey: | | |Prentice Hall, 2004. | | | | |Parson, J. and Oja, D. |Computer Concepts, New York: International Thompson Publishing | | |Company, 2007. | | | |Shelly, G. , Cashman, T. , and Vermaat, M. |Discovering Computers, New York: International Thompson Publishing | | |Company, 2008. | ? UNIT 2: APPLICATION AND IMPLICATION MODULE 1: INFORMATION MANAGEMENT GENERAL OBJECTIVES On completion of this Module, students should: 1. acquire the knowledge needed to organize and manage data, making it meaningful to an organization; 2. demonstrate the skills needed to organize and manage data within a database. SPECIFIC OBJECTIVES | |CONTENT | | | | | |Students should be able to: | | | | | |differentiate among terms used in Information | |For example, fields, records, tables, files, database and database management | |Management; | |system. | | | | | |explain how files and databases are used in | |Uses: including s tore, organize, search, retrieve; eliminate redundancies; data | |organizations; | |mining, data marts and data warehouses. | | | | |explain how data storage and retrieval have changed over| |Concept of the terms; history of storage devices; formats of data (from | |time; | |text-based to multimedia); volumes to be stored; compression utilities; access | | | |method and speed. | | | | | |explain the advantages of using a database approach | |Advantages including speed, efficiency, cost; data quality: completeness, | |compared to using traditional file processing; | |validity, consistency, timeliness and accuracy; data handling, data processing. | | | | |describe the different types and organization of files | |File types including master and transaction files; file organization including | |and databases; | |serial, sequential, random or direct, indexed sequential database types including| | | |personal, workgroup, department and enterprise databases; database organization | | | |including hierarchical, relational, network and object-oriented. | | | | |describe data flow diagrams (DFD); | |Define DFD; identify and describe the four symbols (elements): entity, process, | | | |data store, data flow; identify and describe the various levels of DFDs including| | | |context level DFD and first level detailed DFD. | UNIT 2 MODULE 1: INFORMATION MANAGEMENT (cont’d) |SPECIFIC OBJECTIVES | |CONTENT | | | | |Students should be able to: | | | | | |explain how the growth of the Internet impact on data | |Use of symbols, context level DFD and first level detailed DFD to illustrate the | |handling and data processing; | |information flow. | | | | | |explain how the absence of data quality, accuracy, and | |Including loss of revenue, sales, competitive advantage, customers; poor | |timeliness will impact on organizations; | |decision-making; missed opportunities; impact on problem solutions. | | | | |explain the concept of normalization; | |Definition of normalisation; attribute redundancy and anomalies; normal forms: | | | |including first normal form (1NF), second normal form (2NF), third normal form | | | |(3NF); keys: primary, foreign and composite (or compound or concatenated); | | | |partial and non-key dependencies; relationships, use of entity-relationship | | | |diagrams (ERD). | | | | |apply normalisation rules to remove normal form | |To 1NF, 2NF and 3NF; removal of attribute redundancy and anomalies, such as | |violations; | |repeating groups of data (or attributes), partial and non-key dependencies. | | | | | |explain how normal for relations impact databases; | |Including improve performance, data consistency, data integrity. | | | | | |construct a database. |Including forms; reports, queries, tables, tuples, relationship links, enforcing | | | |referential integrity, updates or deletions, use of foreign keys, use of macros, | | | |SQL, data validation and verification strategies; used to analyse data and | | | |provide multiple viewing and reporting of data. | | | | | Suggested Teaching and Learning ActivitiesTo facilitate students’ attainment of the objectives of this Module, teachers are advised to engage students in the teaching and learning activities listed below. 1. Choose a single scenario to which students can easily relate, such as a library system or student registration system, and use it throughout the Module to develop understanding of the specified concepts and techniques. UNIT 2 MODULE 1: INFORMATION MANAGEMENT (cont’d) 2. Ask students to complete several exercises on the normalisation process involving the use of standard notations to remove normal form violations. 3. Compile a glossary of terms using the Internet, computer magazines, textbooks and other information sources.This could form the basis of an in-class discussion. 4. Students should design and construct a database. 5. Develop and use diagrams to represent the concepts and relationships contai ned in the Specific Objectives. RESOURCES |Daley, B. |Computers are your Future, New Jersey: Pearson Prentice Hall, 2007. | | | | |Heathcote, P. |A Level Computing, Letts, London: Letts, 2005. | | | | |Long, L. and Long, N. Computers: Information Technology in Perspective, New Jersey: | | |Prentice Hall, 2004. | | | | |Parson, J. and Oja, D. |Computer Concepts, New York: International Thompson Publishing | | |Company, 2007. | | | | |Shelly, G. , Cashman, T. and Vermaat, M. |Discovering Computers, New York: International Thompson Publishing | | |Company, 2008. | UNIT 2 MODULE 2: USE OF INFORMATION TECHNOLOGY TOOLS GENERAL OBJECTIVES On completion of this Module, students should: 1. develop confidence in selecting and using productivity tools to solve real-life problems; 2. use their knowledge and understanding of a variety of software tools and apply their use to various situations; 3. develop the competence to present information in the appropriate manner; 4. use informat ion critically; 5. develop an awareness of emerging technologies. SPECIFIC OBJECTIVES | |CONTENT | | | | | |Students should be able to: | | | | | |explain reasons for the use of IT tools; | |Enhanced speed, accuracy, reliability, efficiency, flexibility, communication, | | | |presentation of information, integration of processes, decision making; storage | | | |and retrieval of large volumes of data; manageability of task; pressures from | | | |clients, competitors and suppliers. | | | | |explain the functions and uses of the major types of | |Examples of different types of software packages and their function and uses. | |software tools; | |Including Financial Packages, Software Development Tools, Statistical Tools, Word| | | |Processors, Spreadsheets, Presentation Tools, and Database Management Tools, | | | |Desktop publishing, graphics and personal information management. | | | | | |explain where a word processing tool is appropriate; | |Main purpose and uses; significa nt features of the tool. | | | | |explain where a spreadsheet tool is appropriate; | |Main purpose and uses; significant features of the tool. | | | | | |explain where a presentation tool is appropriate; | |Main purpose and uses; significant features of the tool. | | | | | |explain where a database management system tool is | |Main purpose and uses; significant features of the tool. |appropriate; | | | | | | | |jon | |UNIT 2 | |MODULE 2: USE OF INFORMATION TECHNOLOGY TOOLS (cont’d) | |SPECIFIC OBJECTIVES | |CONTENT | | | | | |Students should be able to: | | | | | | | |use IT tools to solve real-life problems; | |Including hardware, application software, and communication tools; main purpose | | | |and uses of tool; significant features of the tool. | | | | |justify the use of IT tools to solve real-life problems;| |Criteria for selection including the nature of the solution, type of analysis | | | |required (calculations, formatting, graphing), type of data, type o f storage, | | | |type of access method, type of processing, type of reports (detailed, summary, | | | |preformatted, ad hoc). | | | | | |use the most appropriate format to display or present | |Format including text, graphics, sound, video, graphs, charts and tables. |information; | | | | | | | |use appropriate information sources to retrieve and | |Criteria for selection, appropriateness for task, types of information sources: | |disseminate information for a particular task; | |including books, journals, catalogs, magazines, newspapers, online libraries, | | | |CD-ROMs, DVDs, electronic databases, web sites, and people. | | | | | |justify the acceptance or rej

Free Essays on The Little Rock Nine

Little Rock’s Crisis: A Year of Trouble The stories of the Little Rock nine have been a popular topic over the years, and have spawned articles, books, and even a major motion picture. All of these mediums have certain audiences that they attract. It is the job of the author to know what kind of audience he is facing. Newspapers and Journals are important tools to illustrate the difference in certain audiences. A newspaper offers a broad range of topics like sports, politics, and general everyday events. The Arkansas Democrat is a newspaper located in Arkansas, and on Sunday, September 27, 1998, it published an article titled, Little Rock’s â€Å"Lost Class† of 1959 recalls turbulent year, by Andrew A. Green. On the other hand, a journal is more focused on the interest of an individual, and is usually published by a university or research group. Arkansas Historical Quarterly is an example of a journal, and in the most recent volume, Spring of 2003, it also covers the story of the Little Rock nine ti tled, Segregationist Discourse, by Phoebe Godfrey. Although the articles are on the same topic, they differ in a variety of ways. The professions of the authors is a big reason for the difference in the articles, but the audience that the author is trying to reach is also important. Newspapers are designed to reach a wide audience, and cover a wide range of topics. In the article by Green, he covers a topic that would ordinarily be done by a professional in the field of history, but he writes in such a way that would be interesting for many different kinds of people. The story is about the closings of schools in the Little Rock after the integration of students in 1957. Green focuses on the students and their accounts of the tragedy. By incorporating the former students in his article he draws in a variety of readers. Adults that grew up during that time period would find it interesting to see their peers recollection ... Free Essays on The Little Rock Nine Free Essays on The Little Rock Nine Little Rock’s Crisis: A Year of Trouble The stories of the Little Rock nine have been a popular topic over the years, and have spawned articles, books, and even a major motion picture. All of these mediums have certain audiences that they attract. It is the job of the author to know what kind of audience he is facing. Newspapers and Journals are important tools to illustrate the difference in certain audiences. A newspaper offers a broad range of topics like sports, politics, and general everyday events. The Arkansas Democrat is a newspaper located in Arkansas, and on Sunday, September 27, 1998, it published an article titled, Little Rock’s â€Å"Lost Class† of 1959 recalls turbulent year, by Andrew A. Green. On the other hand, a journal is more focused on the interest of an individual, and is usually published by a university or research group. Arkansas Historical Quarterly is an example of a journal, and in the most recent volume, Spring of 2003, it also covers the story of the Little Rock nine ti tled, Segregationist Discourse, by Phoebe Godfrey. Although the articles are on the same topic, they differ in a variety of ways. The professions of the authors is a big reason for the difference in the articles, but the audience that the author is trying to reach is also important. Newspapers are designed to reach a wide audience, and cover a wide range of topics. In the article by Green, he covers a topic that would ordinarily be done by a professional in the field of history, but he writes in such a way that would be interesting for many different kinds of people. The story is about the closings of schools in the Little Rock after the integration of students in 1957. Green focuses on the students and their accounts of the tragedy. By incorporating the former students in his article he draws in a variety of readers. Adults that grew up during that time period would find it interesting to see their peers recollection ...