PURSE 2001

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An assessment of energy substitution possibilites in the Sri Lankan economy
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Dissnayake, M.N.; Gunatileka, H.M.
Energy is a very important input in the production process of a country. Sri Lanka imports its entire requirement of crude oil and oil products. Domestic energy resources consist of only biomass and hydropower. Higher dependency of an economy on a particular input, especially when large amount of that input are imported, renders the economy vulnerable to external price shocks. Sri Lankan energy importation statistics show that the demand for imported energy is increasing by 9% per annum and neariy 3% of the country's GDP is spent on energy imports. Therefore, external energy price shocks can have a profound impact on the Sri Lankan economy. In fact, the current economic slow down in Sri Lanka is partly due the higher energy prices There are many ways to reduce the dependency of an economy on imported energy. This study explored one such possibilities: substitution of energy with other inputs. The objectives of this study were to examine substitution possibilities between energy and non energv inputs in Sri Lanka and to identify the responsiveness of factor demand to price changes The specific aim was to estimate the elasticity of substitution for the basic factors of production in the Sri Lankan economy to check the substitutability among them. In addition, own I price and cross price elasticities of demand were estimated to examine the price responsiveness of energy inputs. The selected factors of production for the analysis were labour, capital and petroleum 1 based energy Data on GDP, quantity of labor, quantity of petroleum energy, amount of capital, 1 price of petroleum, interest rates and wage rates were collected from different secondary sources. Quarterly data for the period of 1990-1999 were used in the analysis Data limitations did not allow extension of the data set for the periods before 1990. Factor share equations for labor, capital and petroleum energy, derived from a Translog production function, were estimated. The estimation was carried out as a system of equations using Seemingly Unrelated Regression ( method. Price elasticities and elasticities of substitution were calculated using estimated share equation parameters. The results reveals that the petroleum energy is price inelastic and it behaves as a complement with other two inputs Hence, the results imply that, substitution possibilities of both labor and capital, in place of energy, do not exist given the structure of the economy. Of the two ways 10 reduce energy dependency, i.e., energy conservation and substitution, these results suggest that energy conservation is the only possible way to deai with the situation. To achieve higher efficiency from energy conservation practices, various educational, administrative and fiscal measures can be used as part of the government policy Results also show that the use of price as a mechanism to reduce energy consumption will not be an effective reform strategy due to price inelasticity of energy.
Antimicrobial Activity of Some Sri Lankan Rubiaceae and Meliaceae
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Jayasinghe, U. L. B.; Jayasooriya, C. P.; Bandara, B. M. R.; Ekanayake, S. P.; Merlini, L.; Assante, G
Continuing our work on biologically active compounds from Sri Lankan plants we have now screened 94 solvent extracts (n-hexane, dichloromethane and methanol) obtained from leaves, bark and stem of thirteen Rubiaceae species (Benkara malabarica, Canthium coromandelicum, Canthium dicoccum, Haldina cordifolia, Ixora calycina, Morinda tinctoria, Mussaendafrondosa, Psychotria gardneri, Psychotria nigra, Psycho tria stenophylla, Saprosma foetens, Tarenna asiatica and Wendlandia bicuspidatay and two Meliaceae species (Aglia congylos and Munronia pumilia) for antibacterial activity against Escherichia coli (Ec), Micrococcus luteus (Ml), Bacillus subtilis (Bs) and Bacillus cereus (Bc) and antifungal activity against Saccharomyces cerevisiae (Se), Ustilago maydis (Um) and Aspergillus niger (An). Screening for antimicrobial activity was carried out using the disc diffusion method. The media used for culturing bacteria, fungi and yeast like fungi were nutrient agar, Czapek agar and glucose yeast agar, respectively. The plants M.tinctoria, M.frondosa, P. gardneri and P. stenophylla showed antimicrobial activity against at least five of the seven microbes examined: M. tinetoria (leaves) - hexane extract against Ec, Bs, Be and An, and dichloromethane extract against Sc, Ec and Be; M tinetoria(bark) - dichloromethane extract against Se, Ec, Bs and An, and methanol extract against MI and Be; M frondosa (leaves) - dichloromethane extract against Sc, Ec, Bs and Be, and methanol extract against Bs; M frondosa (bark) - hexane extract against Sc, Um, Ml and Be, dichloromethane extract against Se, MI and Be, and methanol extract against Ec and Bs; P. gardneri (leaves) - dichloromethane extract against An,. and methanol extract against Sc, £C, Ml and Be; P. gardneri (bark) - hexane extract against An, dichloromethane extract against Se and Bs, and methanol extract against Ec, MI, Bs and Be; P. stenophylla (leaves) - dichloromethane extract against Ec; P. stenophylla (bark) - dichloromethane extract against Um, £C, MI, Bs, Be and An and methanol extract against MI. The following extracts were found to be inactive: A. congylos (leaves - methanol), B. malabarica (leaves - hexane), C. coromandelicum (leaves - hexane), H. eordifolia (leaves -hexane, bark - hexane and methanol), I. calycina (bark - hexane), M tinetoria (leaves-methanol, bark - hexane), M. frondosa (leaves - hexane), M puma/ia (leaves - hexane, dichloromethane and methanol), P. gardneri (leaves - hexane), P. nigra (leaves - hexane and dichloromethane), P. stenophylla (leaves - hexane and methanol, bark - hexane), S. foetens (bark - hexane), T asiatica (bark - hexane), W bicuspidata (leaves - methanol, bark - methanol).
Apple tissue base biosensor for thiram
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Weliwegamage, U. S. K.; Navaratne, A.
Some plant tissues, such as pineapple, tea, apple and potatoe tissues, contain the enzyme; called polyphenol oxidase, which catalyses the oxidation of catechol to o-quinone in the primary enzymatic step. Thiram is a frequently used dithiocarbamate fungicide in vegetable cultivations world wide including Sri Lanka. It is also used as a seed protectant and as a soil spray. The excess amounts of thiram pollute the water resources and soil in agricultural areas. Hence the trace level determination ofthiram is highly desirable. An electrochemical biosensor was developed to detect thiram using the apple tissue polyphenol oxidase. The enzyme interacts with thiram to give an oxidative voltammetric behavior: an oxidation peak was clearly observed at +0.10V vs. SCE in phosphate buffer solution at pH 7. The electrochemical response of thiram-enzyme system depends strongly on the solution pH. The peak current responses observed at pH 1,3, 5, 7 and 9 were 0.00 µA, 3.00 µA, 6.75 µA, 11.25 µA and 8.75 µA respectively. Further the continuous scanning studies carried out at same medium suggested that the analyte is highly adsorbed on to the electrode surface during this process. The voltammetric response shows a significant dependence on medium pH. The optimum pH for the voltammetric process was found to be 7, where the best pH reported for the reactivity of polyphenol oxidase. The method was used to detect thiram in a standard solution of 1.0x 10-6 mol dm-3, which was accomplished by preconcentration of analyte on modified electrode prior to cyclic voltammetric analysis. In the preconcentration process, the solution was stirred for an accumulation period of 15 min with applying a potential of O.OOV vs. SCE as the accumulation potential.
Application of CO2 laser for oral soft tissu surgery in children
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Jayawardena, J. A.; Kato, J.; Wijeyeweera, R. L.
Lasers are increasingly being used for many operative procedures in Dentistry. One of these lasers, namely C02, has been reported to be very .effective in surgery involving oral soft tissues. CO2 laser is capable of incising and excising soft tissues through a mechanism called tissue vaporization, during which a surface coagulation layer is produced, at the operating site. As a result, the operating field remains clear during the operation, and there is no need of suturing after the operative procedure. The objective of this study was to clarify the effect of C02 laser irradiation on oral soft tissue problems of children in Sri Lanka. In this report the continuous C02 laser at 10.6J.L m with low power was used in 20 subjects, aged between 2 and 15 years, having main indications for labial frenectomy, treatment of ankyloglossia and excision of mucocele. The results indicated that C02 laser has the following advantages 1. The operation time required was lesser when compared with the conventional surgical procedure. 2. The procedure of the operation was simple. Hence, there was no need of general anaesthesia. 3. There was no post-surgical infection. 4. The contraction and scarring of the wound was minimal. We conclude that the use of CO2 laser is a safe and effective method for soft tissue surgery in children.
Analytic philosophy: A brief appraisal
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Kalansuriya, A. D. P.
Analytic philosophers identify the very subject of Philosophy with an analysis of words, terms, notions, expressions, statements, etc.. Wittgenstein gave a new impulse to analytic philosophy with the radiant notion, namely, "A main source of our failure to understand is that we do not command a clear view of the use of words." This is a clear recognition of human failure together with a committed estimate of the ability to engineer solutions for problems that have befallen the best brain since the Greeks. "A clear view of the use of words." But, then, what does it mean? One has to note the nature of the discourse, that of the doctrine, that of the argument, etc. (to which Wittgenstein says 'language game') in which it finds expression that is its original home, in which alone it meaning. Two conclusions follow (i) that confusions, which occupy us do not arise. (ii) which are already there, can be dispelled. The implication being a therapeutic one reminds of a prescription for doing philosophy. That is, putting the word in its linguistic context and whole statement in its native context. But, then, how does one do this? By accepting and mastering analytic techniques. The resuIt: To bring words back from their metaphysical to everyday usage (L Wittgenstein, 'Phylosophical Investigations, 1953: 48e), implying that metaphysics does not have a logic of its own whereas other discourses have a logic of their own. Implied are "chains of reasoning" or "forms of life" in all discourses other than 'philosophy'; for 'philosophy' is not a discourse an analytic activity. Based on this concept of "chains of reasoning," one sees not only the nature of the discourse--science, religion, aesthetics, etc. but also the limits pertaining to 'truth' or 'falsity' of statements that come within first-order disciplines. This brings out the very base of Analytic phylosophy understood and practiced in the English-speaking world as a second-order discipline.
Anatomical variations in common an external carotid arteries in Sri Lankans - A preliminary study
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Banneheka, B. M. H. S. K.; Vithanaarachchi, C.; Nanayakkara, C. D.
Carotid arteries are the main sources of blood to the structures in the head and neck region. Normally, the right and left Common Carotid arteries differ in origin and length, they persue a similar course and distribution after being divided into External and Internal carotid arteries in the neck. The normal course and distribution of these arteries has been studied and well documented. Although some of the anatomical variations in these structures have been identified and reported earlier, such data is available only for western populations. During this study, the origin, course and the level of bifurcation of the common carotid arteries, branching pattern and important relations of the external carotid arteries and the diameters of these vessels at different anatomical levels were looked into while special attention was paid to identify the anatomical variations. Although it is not possible to draw any final conclusions, the results of this preliminary study shows that anatomical variations of common external carotid arteries are relatively common among the Sri Lankans. Higher or lower bifurcation and unusually tortuous course of common carotids and several variations in the course and branching pattern of external carotids, which were found during the study, are reported here.
Anatomy and categorization of pegmatites around Moragahakanda area
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Pitawala, A.
Pegmatitic occurrences are commonly observed in the proposed Moragahakanda- reservoir area. Most of them are characterized by economically important minerals such as quartz, feldspar and mica. At present, some pegmatites are mined for needs of the industry and there is a surplus of raw materials. As a result, there has not been any serious attempt to determine the extent and distribution of pegmatites. Three types of pegmatite occurrences, which are genetically different from each other, are observed. The older occurrences formed perhaps due to metamorphic events contain coarse to very coarse grains (up to few ern) of quartz and feldspar as major minerals and amphibole and mica as accessory minerals. They are smaller light coloured bodies several meters in length. On the other hand, dark coloured pegmatites are characterized by coarse to very coarse grains (up to several em) of pyroxene, amphibole and mica and they are occasionally associated with dykes of pyroxenite. They occur as bands parallel to the general trend of surrounding metamorphic rocks. The mineralogical composition and the filed relationship suggest that these bodies had formed at greater depths, perhaps subsequent to a metamorphic event. However, younger, strongly zoned pegmatites may have been formed at shallow depths. They are mainly made up of mega size crystals (up to several meters) of quartz and feldspar. The minor mineral constituent of the bodies is mica. Fluorite, tourmaline and opaque minerals occur as accessory minerals.
Antibotic resistance of organisms isolated form clinical cases at the microbiological diagnostic labortory
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Panawala, P. V. S.; Wijewardana, T. G.; De Alwis, M. C. L.
Antibiotics are used as therapeutic as well as prophylactic measures in livestock industries and pet animal clinics. Use of antibiotics without any restrictions or rationale has led to serious problems such as drug resistance and hypersensitivity in the human population. The antibiotic sensitivity pattern of causative organisms isolated from specimens submitted to the microbiological diagnostic laboratory at the Faculty of Veterinary Medicine and Animal Science during 12.06.2001 to 12.10.2001 was analyzed with a view to detect any drug resistance. The bacterial isolates obtained from a total of 37cases showed resistance to a number of antibiotics tested. The organisms isolated and included in the study were Ecoli, Streptococcus spp, Klebsiella spp., Pseudomonas spp., Aeromonas spp., Jonesia spp, Acinetobactor spp, Staphylococcus spp and coliforms. These isolates originated from 24 canine, 8 bovine, 2 feline and 3 wild animal samples. Seventy three percent of the organisms studied showed resistance to trimethoprim + sulphadiazine combination. A few organisms (10.8 %) showed resistance to gentamycin. Only one organism (a Staphylococcus spp.) showed resistance to amoxicillin + clavalunate combination. The other antibiotics for which the organisms showed resistance were erythromycin (37.8 %), tetracycline (29.7 %), ampicillin (24.3 %), methicillin (2l.6 %), penicillin (18.9 %), enrofloxacin (13.5 %), mupirocin (2.7 %), cephradine (2.7 %), streptomycin (2.7 %), diclloxacillin (2.7 %), and norfloxacin (2.7 %). The results of the study so far show the potential danger of continuous use and abuse of antibiotics.
Analysis of polycyclic aromatic hydrocarbons(PAHs) in ambient air
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Karunaratne, D. G. G. P.; Jeyalalitha, E.
Most studies of emissions from combustion for energy generation have been aimed at abating inorganic emissions COₓ, NOₓ and SOₓ owing to the strict legislations to which these compounds have been subjected and because they are emitted in large amounts in comparison to organic emissions. Technical modifications to reduce inorganic emissions have affected organic emissions so that growing attention is being paid now to volatile organic compounds, particularly to polycyclic aromatic compounds (PACs) and, especially to polycyclic aromatic hydrocarbons (PAHs) owing to their carcinogenic character. Although there is no definitive legislation concerning PAH abatement, the Environmental Protection Agency (EPA) has fixed 16 PAHs as priority pollutants, the last of which was included in 1997. These compounds are as follows: naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, chrysene, benzo (a) anthracene, benzo( b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, indeno( 1,2,3-c,d) pyrene, benzo(g,h,i)perylene and dibenzo(a,h)antracene. It is expected that air quality would improve soon if PAH emission was controlled. The simplest member of the PAH family is naphthalene, a two-ring compound which can be found in the vapour phase in the atmosphere. Three-, four-, and five-ring compounds can also be found in both the vapor and particulate phases in the atmosphere. PAHs consisting of five or more rings tend to be solids adsorbed onto other particulate matter in the atmosphere. A widely recognized five-ring PAH compound is benzo (a) pyrene. Naphthalene is by far the predominant airborne PAH. Night time concentrations of naphthalene are greater than daytime concentrations because of the hydroxyl radial reaction mechanism which removes naphthalene from the atmosphere in daylight. As ring size increases, the effect of this removal mechanism diminishes. These gaseous- phase reactions are important because they also lead to the formation of nitro-P AHs which are direct acting mutagens. High volume air samplers equipped with polyurethane foam (PUF) adsorbent have been a standard device for monitoring semi-volatile organic compounds (SVOCs) in air for a number of years. In such samplers, air is drawn past a filter to retain particle-phase SVOCs and then past the PUF adsorbent to retain vopour-phase SVOCs. This sampling geometry has the potential to cause sampling artifacts, most notably "blow-oft" whereby SVOCs which are adsorbed on particulate matter in ambient air may be volatilized from the particles after collection on a filter medium, thus enhancing the apparent vapour-phase concentration. A second effect which may occur is "blow-on" whereby vapor-phase SVOCs in ambient air are adsorbed on the filter media or on accumulated particulate and/or organic matter on the surface of the filter media. This would result in an apparent increase in the particle-phase loading of the SVOC in question. It is important to note that both of these phenomena can occur simultaneously.
Analysis of how to control the pollution due to wastewater from textile industry
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Abeyarathne, W. G. N. S.; Karunarathne, D. G. G. P.; Herath, G. B. B.
The textile and garments industry is the largest industrial sector in Sri Lanka. Direct and indirect employments in these industries are estimated to be over 500,000. The textile industry manufactures finished cloth from imported raw materials. Manufacture of finished cloth from raw fibre (cotton and synthetic) involves 3 major operations as, spinning, weaving/knitting and finishing. Spinning and weaving are essentially dry processes and cause therefore relatively minor pollution problems. Significant pollution problems are, however, caused by the various finishing operations, including desizing, washing, scouring, mercerizing, bleaching, dyeing/printing and various types of final treatment processes. The finishing processes consume large quantities of water producing substantial volumes of liquid waste, which is a significant source of water pollution in Sri Lanka. The textile processing industry in Sri Lanka is probably the 2nd largest polluter after the natural rubber industries, which jointly generates a liquid waste load of about 45,000kg COD/day (Industrial pollution control guidelines from CEA). This wastewater contains various compounds, which are harmful for the aquatic environment and are toxic for human and animal in cases of ingestion or physical contact. Textile processing wastewater contain oil, dye and biodegradable organic compounds, which may cause anaerobic conditions in receiving surface waters, resulting in die off of fish and other water organisms and emission of foul odours. Wastewater treatment systems of textile processing industries generally consist of biological and/or physical/chemical treatment processes, or combinations of these processes. After these processes the treated water discharges to the nearby stream. The chemical and bio sludge resulting from the process are subjected to drying on a sand bed and then discharges without further treatment (normally used for land filling). The aim of this research is to analyse how to control and minimize the pollution due to this wastewater & sludge discharge. The production of waste from textile processing operations can be prevented or reduced by numerous different measures. Such measures include replacement of toxic process by less harmful chemicals, process modifications and good housekeeping practices. Similarly the sludge also can be analysed for the harmful substances and we can find methods to treat them.
Aerated soaking of paddy for rice parboiling and its effect on effluent kinetics
(Unviersity of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Senanayake, S. S.; Basnayake, B. F. A.; Mowjood, M. I. M.
Parboiling is practiced to increase the milling performance and cooking quality of rice. The main steps in parboiling process are soaking, steaming and drying of paddy. Traditional cold soaking is one of the methods used for soaking in which the paddy is submerged in water for a period of 48- 72h. The effluent from this method is in poor quality and has the potential to pollute the environment, water bodies and lands. This study was carried out to find a solution to reduce the environmental impact of effluent release from parboiling process. The effluents (traditional parboiling method - T 1) from five mills in Anuradhapura were collected and the colour, odour, turbidity, temperature, pH, Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Solids (TS), and Total Suspended Solids (TSS) were measured. Alternatively two laboratory models were developed and tested for aerated soaking. In the first model (T 2) the water was trickled over the paddy at the rate of 1000ml/min and drained water was re-circulated to reduce the amount of water needed for soaking In the second model (T,) a charcoal filter was introduced before the re-circulation of water to study the effect of charcoal treatment in the effluent The effluent samples from 11, 12 and 13 were incubated at 20°C and Dissolved Oxygen (DO) was measured in 12h intervals for 5 days to calculate BOD values. DO was measured using Winkler titration method The rate constants were estimated from the BOD curve developed for the three treatments. Average temperature, pH, COD, TS and TSS values of the eftluent of T 1 were 38°C , 6.1, 2548 mg/l, 150 mg/l and 50 mg/l, respectively. The effluent from T 1 also had the highest mean BOD value (2452 mg/I) at the end of 5 days, unpleasant colour and odour though the degree of contamination varied among the mills These results indicate the potential of the effluent of the traditional method as a pollutant. Effluents of the laboratory models (T2 and T3) recorded much lower BOD values at the end of 5 days (356 and 128 mg/l, respectively) with no unfavorable colour or odour T3 recorded the lowest rate constant (0.07 per day) when compared with T, and T2 (0.28 and 0.15 per day, respectively). In the aerated soaking methods (T2 and 13) tested, water can be recycled. In addition, the soaking time needed to absorb water up to optimum moisture content was less in T2 and T3 compared to that of traditional method. Eating quality of rice was also observed to be high with the aerated models than with the traditional method. Power requirements and cost - benefit analysis have to be studied to improve the aerated soaking system in mills. Further studies are necessary to identify carbonaceous and nitrogenous demand in the BOD curves of the models considered Further understanding on the kinetics of effluent can lead to design more efficient aerated soaking and effluent treatment reactors.
Palugolle Ayyana Paththini Dewalaya
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Senanayake, P.
pdf attached.
Utilization of medicinal plants/cereals/legumes in formulation of instant Kola-Kenda (Green-Porridge) mixtures
(Unviersity of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Gamlath, G. G. S.; Thevakaran, K.; Gunatilaka, K. D. P.; Illeperuma, C. K.
Kola-kenda is a traditional drink with many medicinal and nutritional benefits. However, habit of consumption of kola-kenda is disappearing fast due to difficulties in obtaining suitable leaves and inconveniences associated with traditional preparation methods. The study was conducted to establish the processing variables in the formulation of instant kola-kenda mixtures using unexplored medicinal herbs such as Curry leaves (Murraya koenigiiv, Kalukamberiya leaves (Solanum nigrum) and Heenbovitiya leaves (Obeckia octandra). The herbs were dried after steam blanching or water blanching The three pre-treatments for rice included precooking, wet milling or dry milling. Soya bean was either roasted or dried after boiling. The herbs were mixed separately with rice and soya bean (used in place of coconut) to develop nutritionally and organoleptically sound products. The best proportion cf ingredients in the mixtures were identified The best formula for each herb was selected based on physical (colour, viscosity and cooking time), nutritional (crude protein, crude fat, crude fiber and total ash contents) and sensory properties (appearance, taste, colour, aroma, consistency and overall acceptance) of the final product. A sample currently available in the market was used as the control for statistical comparisons. The best pretreatment combinations which received the significantly (P
The vegetation of Ussangoda
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Wickramaratne, S. N.
Situated, about 222 km south of Colombo close to Nonagama Junction in the Ambalantota DS division, Ussangoda is a unique area both geologically and ecologically. It is one of the few, known serpentine areas of Sri Lanka. Yet, unlike other serpentine areas of the country Ussangoda is a coastal geological formation, with open scrub vegetation. There are also legends associated with this site adding a cultural value to it. This area has been declared 'pre-historic site' under the Coast Conservation Department while its periphery is part of Kalametiya Sanctuary under the purview of the Department of Wildlife Conservation.The objective of the present study was to survey this area's vegetation with emphasis on zonation structure and composition. The methodology consisted of: (1) identification of soil units and (2) study of vegetation in the soil units. The topographic parameters and location were studied by a GPS survey. Slope was measured by an Abney Level. Soil color was determined by the use of Munsell Color Chart. Vegetation was studied in the field in quadrats (114 m2 ones in open areas). No soil chemical analyses were done. The study revealed the following: Ussangoda is a mound-like edaphic unit gently sloping on all directions ranging from 07m to 30m above sea level. Slope varies between 07% and 10%. The undifferentiated soil overlying serpentine rocks has two units: (1) A 'Re Earth' formation similar to what is found in the Aruakalu area north of Puttlam (10R 3/6 dry and 2.5 YR 3/4 wet). (2) A yellow to white formation (10 YR 5/4 dry and 2.5 YR 3/3 wet 5YR 4/4 dry and 5YR 3/4 wet. These overlying soils do not seem to be typical chocolate brown 'serpentine soils' found in the serpentine areas of Yudagana-pitiya, Gingal-pelessa and Indikola-pelessa. Each of the two soil units has dense 'scrub' vegetation areas and 'open vegetation areas. The open areas include several small (scrub islands' of varying size. If the narrow 'shore-line vegetation' is excluded there are 29 species of flowering plant common to the area They belong to 21 families. Seventeen woody species (within 12 families) are in the scrub vegetation including scrub islands whereas; 12 species of non-perennial herbs (within families) exist in the open vegetation areas. The presence of 'nickel hyper accumulators among the herbs in the Red Earth area has been reported by Seneviratne et al. (2000) in Pro 6th Annual Forestry Symp. of the Dept of Forestry, Univ. of Sri Jayawardenapura and Ministry of Forestry and Environment. Tree height in the area ranges from 1.4 m to 3.7 m. In the open areas the trees and prostrate. The dbh of tree species ranges from 1.5cm to 12.4 em. The open vegetation area have discontinuous ground vegetation of which the density ranges from 98 to 53 individual /2500cm2 (i.e. 11.1 m2).
Use of cation exchange membrane in the electridiaysis treatment of black liquor
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11) Ariyaratna, S. M. W. T. P. K.; Shantnini, R.; Walgama, K. S.
The liquid effiuent from the Embillipitiya pulp mill, known as black liquor, is an extremely complex substance containing chemicals such as residual sodium hydroxide, sodium carbonate, sodium silicate, sodium lignite, phenolic compounds, and some organic acids. Its black color is due to the presence oflignate ions which are almost impossible to decompose by biodegradation. A continuous release of black liquor into a water body has the potential to kill all the aquatic life in the water body and eventually turn it into a dead one. Black liquor has successfully been converted into a colorless liquor in an electrodialysis unit used to fractionate Embillipitiya black liquor into sodium hydroxide, lignin and organic acids cellophane was used as the anode and cathode side membranes in this electrodialyser. As a further improvement to the system, the cathode-side cellophane membrane was replaced by a cation exchange membrane, and the performances by the two membranes was compared. The system with the cation exchange membrane yielded a considerably higher rate of separation than the cellophane one. It gained almost half of energy that used for the same separation in the system with cellophane. When operating beyond limiting current densities, unlike cellophane membranes, the cation exchange membrane encourages the water splitting phenomenon. The side effects of water splitting, such as high-energy consumption and damage to membranes, were identified and quantified. Methods to minimize these effects were tested, and were found to be successful. For inctance using dilute NaOH solution, instead of distilled water in the cathode chamber, reduce water splitting. Beside these, the durability of the membranes was also studied and the methods to preserve the membrane for the subsequent runs were also examined. After using the membrane, it was found out to store in 0.1M NaOH solution.
Use of cyclogram technique for the interpretation of water supply borehole data
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Malaviarachchi, M. A. S. P. K.; Dharmagunawardhane, H. A.
Cyclogram mapping technique represents and illustrates well strata logs that depict penetrating lithologies of the boreholes together with other hydrogeologic parameters. This method has been successfully utilized in some other countries, to describe borehole data from sedimentary areas. However, the method has not been applied in crystalline rock areas. Since 90% of the land area of Sri Lanka is a crystalline rock terrain and a large number of water supply boreholes have been drilled in it, an attempt was made to illustrate borehole data using the cyclogram technique. Under the present study, interpretation of borehole data using cyclograms was done for one hundred water supply boreholes in the Polonnaruwa 1:50 000 topographic map. Drawing of cyclograms was done using Microsoft Paint and plotting on map layers was done with Adobe Photoshop 5.5 software packages. Cyclograms were set on a map illustrating all available geological and hydrogeological information on the same layout. Mapping of water supply borehole data using the cyclograms revealed that the method could be successfully applied for showing location of wells and boreholes, three-dimensional illustration of penetrated strata and presentation of other technical and hydrogeologic data from wells, all on a single map. Consequently, it was found that the cyclogram map could be used as a base map of well records, which is essential for proper interpretation of groundwater conditions in crystalline rock areas.
Weekly surveillance of antimicrobial resistance of colanising flora from patients in ICU- general hospital Kandy
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Thevanesam, V; Devolage, M; Ekanayake, E. W. M. A.; Gamage, T. M.
Nosocomial infections are a common cause of morbidity and mortality in Intensive care units (leU). Morbidity and mortality increase when infections are caused by multi-resistant bacteria. There is limited and often anecdotal information on the role of multi-resistant bacteria in leU related infections. A previous attempt to establish a continuous surveillance programme was found to be too labour intensive. The current study attempts to determine the cost effectiveness of a weekly surveillance programme. Weekly surveillance was carried out on all patients in the leu from March to May 2001. Endotracheal aspirate, urine and blood were taken for culture from intubated patients . Ninety six Gram negative bacilli (awaiting identification) were isolated from 27 patients. Antimicrobial sensitivity of the isolates were tested using a standardised sensitivity testing method (BSAC) . Most isolates were resistant to cefuroxime (98.9%). A high proportion of isolates were resistant to commonly used antibiotics such as cefotaxime (87.5%), ampicillin (80.2%) and gentamicin (62.5%). Approximately half the isolates were resistant to co- amoxiclav (48.9%) and ciprofloxacin (51%).Only amikacin (9.4%), meropenem (9.4%) and imipenem (15.6%) retained useful antimicrobial action. It is worrying to see high levels of resistance to rarely used antibiotics such as aztreonam (48.9%) netilmicin (79.2%) and ceftazidime (61.5%) A pilot study to determine the necessity and viability of carrying out surveillance for antimicrobial resistance showed that there is a high incidence of resistance in Gram negative bacilli isolated from patients in a intensive care unit. Although only 27 patients were screened over a period of 7 weeks, the findings suggest that surveillance is essential to monitor the extent and pattern of antimicrobial resistance. However, even weekly surveillance is very labour intensive and time and cost requirements will have to be considered before surveillance is established as routine practice in Sri Lankan hospitals.
The world in the twenty first century
(Unviersity of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Gajameragedera, B.
The objective of this paper is to probe the possibility of the formation of a globs society in the twenty first century, from both theoretical and practical angles. The world, free from the East-West bloc conflict, is passing through a process of revolutionary transformation The basic argument of this paper is that this global change can result in the formation of global society in the course of the twenty first century. It assumes that the world is, at bottom a philosophical problem This concerns the problem identifying the conceptual basis of this world order. It is argued that the problem of striking the right balance between freedom and equality could be the only basis for the establishment of a peaceful, durable, and equitable world order If a world order is established on the basis of striking a right balance between freedom and equality, then there will be a global society From a conventional point of view the only alternative to this is the idea that the world order can rest upon equilibrium of power among the great powers. In this fast changing and inter-dependent world this preposition in untenable.
Trends in the development of learning strategies in a medical school context
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Marambe, K. N.; Vermunt, J. D.; Boshuizen, H. P. A.
Development of an advanced, deep level learning in students is an important purpose of tertiary education. Since the objective of present day curriculum reform is basically to improve the quality of learning processes that students realize, the emphasis is on how the students should learn as well as on what they should learn (the content). Therefore, among researchers, the attention for the quality of learning processes has grown as well. However, Longitudinal, within-subject studies to examine intra-individual changes of the learning strategies are scarce. Furthermore, similar studies have not been reponed within a medical school context in Sri Lanka. The present study aimed to broaden the understanding of the learning process of the medical students in a traditional curriculum. This involves the extent to which students report change, the degree of stability and variability of learning strategies, mental models of learning and learning orientations during the course of studies. Participants were 144 students (82%) from the 1999/2000 batch and 92 students (61%) from 1996/1997 batch of medical students of the Faculty of Medicine, University of Peradeniya, Sri Lanka. Adapted version of the Inventory of Learning Styles called the "Adyayana Rata Prakasha Malawa (ARPM)" was used as the test instrument. The inventory (ARPM) measured learning strategies, learning orientations and mental learning models of students. This study has a within-subject longitudinal design. ARPM was administered prior to the commencement of the academic course proper and towards the end of the third term ofthe Second MBBS course in the case of 1999/2000 batch of students. For the 1996/1997 batch, the same inventory was administered during the first term of Third MBBS part I course and then towards the end of the Third term in the Third MBBS part II course. In the respective batches, only those who completed both inventories were included in the study. Paired samples T-test was used to analyse the changes between variables within each batch. Results showed that both batches of students had reported the use of stepwise processing strategies (memorising and analyzing strategies) less frequently. Within the regulation domain, self- regulation of learning was reported significantly less during the course of studies by both batches of students. The other similarity observed in the two groups of students was the decrease in personal interest in the course of time. However, analysis did not reveal more frequent use of constructive learning strategies such as critical processing and concrete processing in the course of time. It is recommended that these findings, specially the fact that there is no increase in the use of constructive learning strategies and self-regulation strategies, be given special attention during curriculum development.
Treatment of wastewater from service stations
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Werellagama, D. R. I. B.; Amarasiri, S. P.; Salgodo, N. A. B.; Sangakkara, G. L. B.
All vehicles have to be serviced in order to maintain the vehicle in good condition. In servicing a vehicle there are three separate activities, viz. removal of spent engine oil, lubrication and body wash & cleaning under carriage. The types of detergents, used for each of the cleaning processes, are different. Also the contaminants added from the vehicles to the wastewater are also different. The main wastes generated are lubricants and oils that are washed away from the vehicles and detergents that are used at the time of servicing for cleaning purposes. In Sri Lanka often the effiuent from vehicle service stations are discharged to the environment without any treatment. This project was initiated with the objective of finding a solution to this problem by identifying the common constituents of the service station discharge wastewater and proposing a method of treatment based on improving the available treatment methods. This report is on the progress of the initial year of this project. To prevent hazards to downstream users of these waste streams, it is important to treat the wastewater before discharging. To identify the characteristics of wastewater, the wastewater from three service stations, at The Faculty of Engineering, Mawanella and Eriyagama were studied. These were selected due to the proximity to the Faculty of Engineering, Peradeniya; and also due to the willingness of the managers to give their Wastewater samples for analysis. COD, Suspended Solids, Total Solids, Turbidity and pH of the samples were studied. In the absence of any specific discharge standard, the Sri Lanka Standard for Discharge of effiuents to inland surface waters is used to quantify the results. After a thorough literature review, data on available treatment methods were obtained. The methods identified are screening, sedimentation, oil-water separation, secondary sedimentation and reuse of water in the service station. The oil water separation step identified is flotation. Other available de-oiling methods are hydro-cyclone, centrifugation, dehydration, crystallization and distillation. The oil recovered in the oil-water separation step can be sold as it is, recycled, reprocessed, reclaimed or regenerated. With the methodology identified, lab scale tests are being carried out in the Environmental Engineering Laboratory, of the Faculty of Engineering, Peradeniya, to get a practical and cost-effective wastewater treatment solution suitable for Sri Lanka.

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