PURSE 2004

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A statistical analysis of the vegetative characters of Sri Lankan asparagas (𝘍. 𝘢𝘴𝘱𝘢𝘳𝘢𝘨𝘢𝘤𝘦𝘢𝘦)
(University of Peradeniya Sri Lanka, 2004-11-10) Rajapaksha, C. P.; Yakandawala, D. M. D.
𝘈𝘴𝘱𝘢𝘳𝘢𝘨𝘶𝘴 is an important genus of medicinal plants used in ayurvedic medicine in Sri Lanka. The circumscriptions in different taxonomic treatments of the taxa differ with splitting and lumping of species. Four species are recognised, 𝘈. 𝘳𝘢𝘤𝘦𝘮𝘰𝘴𝘶𝘴, 𝘈. 𝘧𝘢𝘭𝘤𝘢𝘵𝘶𝘴, 𝘈. 𝘨𝘰𝘯𝘰𝘤𝘭𝘢𝘥𝘰𝘴 and 𝘈. 𝘻𝘦𝘺𝘭𝘢𝘯𝘪𝘤𝘶𝘴 by upgrading the endemic 𝘈. 𝘳𝘢𝘤𝘦𝘮𝘰𝘴𝘶𝘴 var. 𝘻𝘦𝘺𝘭𝘢𝘯𝘪𝘤𝘶𝘴 to species status. The latest revision in the Flora recognises only three species where the endemic 𝘈. 𝘻𝘦𝘺𝘭𝘢𝘯𝘪𝘤𝘶𝘴 is reduced under 𝘈. 𝘳𝘢𝘤𝘦𝘮𝘰𝘴𝘶𝘴. Field experience suggests the occurrence of several morphological variants with very distinct character combinations that are not listed under the presently recognised species descriptions. Because of these discrepancies, the present study was undertaken to elucidate the number of different Asparagus species that occur in Sri Lanka. Live specimens were collected from all recorded locations and several other locations covering all climatic zones. Plants were studied in detail and characters showing variations were identified. These characters were coded into a data matrix and were subjected to cluster analysis. A total of 50 characters was recorded; but as floral data were not complete for a few specimens, only 23 vegetative characters were included in the analysis. The resulted dendrogram identified five major clusters. Each of these identified clusters was evaluated on the basis of the character combinations of the individuals included within the cluster. Two of these clusters unequivocally agreed with the character combinations of 𝘈. 𝘨𝘰𝘯𝘰𝘤𝘭𝘢𝘥𝘰𝘴 and 𝘈. 𝘧𝘢𝘭𝘤𝘢𝘵𝘶𝘴. The other three clusters together corresponded to the character combination described during the latest revision under 𝘈. 𝘳𝘢𝘤𝘦𝘮𝘰𝘴𝘶𝘴. However, the clear separation of this large cluster into three sub clusters at an acceptable distance indicates the heterogenic nature of the species. Each of these clusters could be supported by character combinations which are unique to each of them; 𝘈𝘴𝘱𝘢𝘳𝘢𝘨𝘶𝘴 with shorter, trigonous, and sickle shaped cladodes of higher elevation; 𝘈𝘴𝘱𝘢𝘳𝘢𝘨𝘶𝘴 with shorter, trigonous, and sickle- shaped cladodes of lower elevation and 𝘈𝘴𝘱𝘢𝘳𝘢𝘨𝘶𝘴 with longer, trigonous, straight cladodes of lower elevation. The results of the cluster analysis using vegetative characters unambiguously identify the species 𝘈. 𝘨𝘰𝘯𝘰𝘤𝘭𝘢𝘥𝘰𝘴 and 𝘈. 𝘧𝘢𝘭𝘤𝘢𝘵𝘶𝘴. Species of 𝘈𝘴𝘱𝘢𝘳𝘢𝘨𝘶𝘴 described under 𝘈. 𝘳𝘢𝘤𝘦𝘮𝘰𝘴𝘶𝘴 is an assemblage of different species of 𝘈𝘴𝘱𝘢𝘳𝘢𝘨𝘶𝘴. The group of 𝘈𝘴𝘱𝘢𝘳𝘢𝘨𝘶𝘴 that occur in the higher elevations with shorter, trigonous, sickle-shaped cladodes is possibly the group that was recognized as 𝘈. 𝘻𝘦𝘺𝘭𝘢𝘯𝘪𝘤𝘶𝘴 (Baker) Hook. f. in 1892
Stresses in a stupa dome with non-homogeneous materials
(University of Peradeniya Sri Lanka, 2004-11-10) Piratheepan, J.; Ragumaran, R.; Thanenjeyan, S.; Ranaweera, M. P.
Ancient Stupas in Sri Lanka are solid structures, mostly made of bricks, and some of them reached colossal proportions. The Jetavana Stupa built by King Mahasena (276-303 AD), reached a height of 122 m, making it the third tallest structure in the world at one time, and it is still the largest brick structure in the world. With the passage of time, and due to the exposure to elements and the neglect, ancient stupas under went decay, and were restored from time to time. Presently the Central Cultural Fund is carrying out restoration!conservation of ancient stupas, and this should be carried out with care and sensitivity. One of the requirements for this is the knowledge of stresses in the stupa, and the identification of critical zones. In connection with the conservation of Jetavana stupa, stress analyses have been done previously, assuming the stupa material to be homogeneous. However, excavations have shown that the dome of the stupa, its largest structural component, have four different zones made of bricks of different sizes, and earth; the outermost zone consisting of large strong bricks and the inner core consisting of earth filling. This paper presents some results of a study of stresses in the dome of the Jetavana stupa, taking into account the non-homogeneity of its material. Analyses were done using the finite element package SAP2000. The dome, which is a truncated ellipsoid of height 52.2 m, and base diameter 105.4 ill, was modelled as an axisymmetric solid of linear elastic material having different values for Young's modulus (𝘌) and Poisson's ratio (ဎ). The loading considered was that due to gravity. The results show that the vertical stresses are moderately sensiuve to material properties, the sensitivity being more to Young's modulus than to Poisson's ratio. The vertical stresses are compressive throughout the dome, and they reach a maximum of 823 kPa at the centre of the base when 𝘌 = 4.5 GPa throughout, and this value starts to decrease as 𝘌 at the core is reduced beyond 2.5 GPa, and reaches 594 kPa at the centre of the base when 𝘌 is made very small. On the other hand, radial and hoop stresses are very sensitive to material properties, especially to Poisson's ratio. They also remain compressive all over the dome, except when 𝘌 is made very low at the core. The mild dependency of the vertical stresses on the material properties is to be expected, as the vertical stress essentially takes up the self weight. The strong dependency of horizontal stresses (hoop & radial) on Poisson's ratio is also to be expected, as Poisson's effect is the main factor causing them. In all cases, stresses found were well below the strengths of the ancient bricks.
A Study of Redox Mechanism of Polypyrrole/ Dodecylbenzenesulfonate Polymer Films Using Optical Absorption and Cyclic Voltammetry
(University of Peradeniya Sri Lanka, 2004-11-10) Velmurugu, Y.; Chandrakanthi, R. L. N.; Careem, M. A.; Skaarup, S.
The properties of polypyrrole (PPy) are strongly influenced by the preparative and other conditions as well as the history of the polymer sample. The dependence of sample history is more prominent in the field of conducting polymers due to the complex nature of polymers when compared to crystalline solids. Therefore, in spite of the tremendous amount of work on conducting polymers, there still exist considerable differences among the results reported in the literature with regard to the properties of polymers. In the present study, the doping of polypyrrole with large anionic detergent dodecylbenzenesulfonate (DBS) has been investigated using the optical spectroscopy and cyclic voltammetry. Reproducible voltammograms were only obtained after the completion of several potential cycles. The optical absorption spectra of the stable state of the film showed an energy gap of 3.05 eV corresponding to a strong π → π* (band gap of neutral PPyIDBS film) transition in its reduced state. In conducting state, a broad absorption peak was present at 1.29 eV indicating the bipolaron formation during oxidation. In addition to this, a small shoulder was observed at around 2.2 eV corresponding to the polarons. These results indicate that bipolarons and polarons are the conducting species in PPylDBS film. But the bipolarons seem to be the dominant species. In addition to the above studies the PPy/DBS films were prepared using SOBS electrolytes having different concentrations to investigate the effect of micelle formation in the solution. The capacities of the cyclic voltammograms obtained for the films made with electrolyte concentrations above critical micelle concentration (CMC) value seemed larger than that of the films made with concentrations below the CMC value. Also in absorption spectra an intensity variation of the peaks and a small shift in isosbestic point with the variation of concentration of SOBS were observed.
Study of structure-solid state photoreactivity correlation in 4-cyanobutyl cobaloxime complexes csing X-Ray powder diffraction
(University of Peradeniya Sri Lanka, 2004-11-10) Pahalagedara, K. R.; Somisara, D. M. U. K.; Vithana, C.
The 4-cyanobutyl group)(δ-cyanobutyl group) bonded to the Co atom in cobaloxime complex is found to be isomerized to α-cyanobutyl isomer though γ and β cyanobutyl groups upon irradiation with visible light in the solid slate. Generally, in solid state reactions, the reactivity depends on microscopic structures present in the solid state in different ways. Hence, in order to identify the structural factors controlling the photoisomerization taking place in 4-cyanobutyl complexes, a series of closely related compounds with known molecular and crystal structures were used to investigate the solid state reactivity. Single crystal X-ray diffraction studies done previously revealed that among six complexes used here, C-C-N groups of 4-cyanobutyl chains of (4-cyanobutyl)(4- sopropylpyridine )bis( dimethy Iglyoximato )cobalt(III) (4cb4ippy), (4-cyanobutyl)(3- methylpyridine)bis( dimethylgl yoximato )cobalt(UI) (4cb3mpy), and (4-cyanobutyl)(3- chloropyridine) bis(dimethylglyoximato) cobalt(IIl) (4cb3c1py) take parallel conformations with respect to the cobaloxime planes, whereas those of (4-cyanobutyl)(isonicotonicacid)bis (dimethylglyoximato) cobalt(III) (4cbisonic), (4-cyanobutyl)( 4-cyanopyridine) bis(dimethylglyoximato) c:obait(III) (4cb4cpy), and (4-cyanobutyl)(aniiine) bis(dimethylglyoximato)cobalt(III)(4cbani). have perpendicular conformations to the cobaloxime planes. The reactivity was estimated quantitatively for each complex as a percent conversion of the reactant to products, taking the change in the intensity of the strongest peak in each X- ray powder diffraction (XRPD) pattern recorded before and after irradiation of samples for 120 hrs, into account. The percent conversion calculated according to the XRPD data revealed that the photoreactivity of complexes having similar alkyl conformations is governed by the size of the void space around the reactive group (reaction cavity volume). Because when there is more space in the cavity, atomic movements are more feasible in the solid state. However, the comparison of the reactivity 01 complexes with different conformers indicated that the C-C-N groups of 4-cyanobutyJ chains with parallel conformations to the cobaloxime planes are topochemically more favorable here, as they have shown high isomerization activity.
A study of the antifungal activity of black tea polyphenols (catechin and theaflavin) against candida species
(University of Peradeniya Sri Lanka, 2004-11-10) Sitheeque, M. A. M.; Panagoda, G. J.; Yau, J.; Amarakoon, A. M. T.; Udagama, U. R. N.; Samaranayake, L. P.
Catechin and theaflavin are two polyphenols found in black tea, the latter being a dimer of the former, which is a theogallate. Catechin and theaflavin are obtained from fermented leaves of the tea plant (𝘊𝘢𝘮𝘦𝘭𝘭𝘪𝘢 𝘴𝘪𝘯𝘦𝘯𝘴𝘪𝘴) by the standard extraction method described by Vuataz et al (1959) and Roberts and Smith (1963). Although anti-oxidant, some antifungal and anti-cariogenic properties of both catechin and theaflavin have been reported there has been no report on any anti-candidal activity of these polyphenols in the literature to date. The objectives of the study are: 1) to verify the antifungal effect of catechin and theaflavin on isolates of five different species of 𝘊𝘢𝘯𝘥𝘪𝘥𝘢; 2) to determine the minimal inhibitory concentration (MIC) of catechin and theaflavin in respect of 𝘊𝘢𝘯𝘥𝘪𝘥𝘢 𝘢𝘭𝘣𝘪𝘤𝘢𝘯𝘴; 3) to determine the existence of post anti-fungal effect (PAFE) if any, of these polyphenols in respect of Cialbicans and 4) to assess the qualitative effect if any on the yeast cells exposed to the polyphenols under study using a scanning electron microscope (SEM). Both catechin and theaflavin solutions were separately prepared to percentage concentrations of 1.25, 0.625, 0.3125 and 0.156 with sterile distilled water. Five isolates of each of the following five 𝘊𝘢𝘯𝘥𝘪𝘥𝘢 species were used for this study: 𝘊𝘢𝘯𝘥𝘪𝘥𝘢 𝘢𝘭𝘣𝘪𝘤𝘢𝘯𝘴, 𝘊𝘪𝘨𝘭𝘢𝘣𝘳𝘢𝘵𝘢, 𝘊 𝘱𝘢𝘳𝘢𝘱𝘴𝘪𝘭𝘰𝘴𝘪𝘴 𝘊𝘬𝘳𝘶𝘴𝘦𝘪, 𝘢𝘯𝘥 𝘊 𝘵𝘳𝘰𝘱𝘪𝘤𝘢𝘭𝘪𝘴. Antifungal effect of the polyphenols was studied using the standard gel diffusion method. The isolates were inoculated on Mueller- Hinton agar (MHA) plates.l Sul, of one of the four concentrations stated above of either catechin or theaflavin was added to wells bored in the middle of the inoculated area. The plates were then incubated for 24-36 hours at 37° C. The experiment was quadruplicated and repeated on a second day. The inhibitory zones observed were measured using an image analysis software on a camera-linked computer. The MIC was determined only with 𝘊. 𝘢𝘭𝘣𝘪𝘤𝘢𝘯𝘴. It was determined visually and spectrophotometrically at 595nm, following 24 h of incubation at 37°C. Post antifungal effect of both polyphenols was studied using the method described by Ellepola and Samaranayake (1998). 𝘊. 𝘢𝘭𝘣𝘪𝘤𝘢𝘯𝘴 ATCC 90028 was exposed to the MIe of both catechin and theaflavin and the cells were prepared in the standard method for SEM study. All isolates of all five species were found to be sensinve to both catechin and theaflavin. There was a statistically significant inter-species variation of sensitivity with 𝘊. 𝘨𝘭𝘢𝘣𝘳𝘢𝘵𝘢 being the most sensitive and 𝘊. 𝘵𝘳𝘰𝘱𝘪𝘤𝘢𝘭𝘪𝘴 being the least sensitive with 𝘊. 𝘢𝘭𝘣𝘪𝘤𝘢𝘯𝘴 and other species occupying intermediate positions. The MIC of both catechin and theflavin for 𝘊. 𝘢𝘭𝘣𝘪𝘤𝘢𝘯𝘴 was found to be 0.625%. PAFE was observed with theflavin but a paradoxical effect of post antifungal enhancement was seen with catechin. Under the SEM the exposed 𝘊. 𝘢𝘭𝘣𝘪𝘤𝘢𝘯𝘴 cells showed structural damage in the form of shrivelling and collapse.
Urinary osmolality: creatinine ratio of spot urine samples relates to body hydration status
(University of Peradeniya Sri Lanka, 2004-11-10) Dissanayake, D. M. M. P.; Godevithanage, S.; Jayalath, W. A. T. A.; Chandrasiri, A. D. N.; Goonasekara, C. D. A.; Jinasena, P. H. R. P.
The objectives of the study were to establish (i) The consistency /inconsistency of early morning spot urine osmolality: creatinine ratio (0: C) in healthy subjects on repeated measurements (ii) the influence of water loading on 0: C (iii) the influence of organophosphate (OP) poisoning on 0: C. Healthy volunteers (n=30) adequately hydrated (a), a similar group of subjects (n=21) (b), and 32 OP poisoned patients in the leU (c) were used for the 3 phases, (i, ii, iii) of this study. Early morning spot urine samples collected on 4 consecutive days from group (a), spot urine samples collected before and hourly intervals up to 3 hours after 1.0 Iof water loading (group (b) and catheter urine samples of ventilated OP poisoned patients (group (c) were analyzed for osmolality and creatinine concentration. Group (a) healthy subjects showed a mean O:C ratio of 66.6 mosmol.kg⁻¹/mmol.⁻¹ (mean osmolality = 534.0 mosmol.kg⁻¹, mean creatinine = 9.89 mmol.⁻¹) and this was consistent on the 4 days. Group (b) healthy subjects showed diminishing values for osmolality and creatinine concentration after water loading. However, the 0: e ratio increased from the basal value and remained elevated at 3 hours, The mean 0: C ratios before and 1, ,2, 3 hours after water loading were 72.72, 96.4, 106.4, 85.93 mosmol.kg/mmol.⁻¹". This increase was significant at 1 and 2 hours after water loading. The 32 OP poisoned patients showed a mean 0: C ratio of 110.8 mosmol.kg'l/mmol.⁻¹ (mean osmolality = 352.30 mosrnol.kg", mean creatinine concentration = 4.11 mmol.⁻¹). Of the OP poisoned group a subgroup of compatible age (20-30 yr) patients (n = 8 ) showed a mean O:C ratio of 100.7 mosmolkg⁻¹/mmol⁻¹ on the first day of poisoning which was significantly different from the early morning spot urine O:C ratio of normal subjects (66.63) (p = 0.01). Results indicated that in adequately hydrated healthy subjects, the spot urine sample is adequate in estimating body hydration status. This was reinforced by the water-loading test in which 0: C ratio increased with increasing hydration, promptly in 1 hour.
Use of multivariate time series model to analyze the effect of the global warming phenominan in Colombo District
(University of Peradeniya Sri Lanka, 2004-11-10) Niruba, J; Wijekoon, P.
In recent years many scientists started to analyze the global warming effect in different regions in the world. They identified that the increased emission of greenhouse gasses has contributed to a manmade rise in global temperature and sea level, which causes long lasting and least reversible problems in the weather patterns around the world. In this study average temperature and rainfall data in Colombo district, collected by the Department of Meteorology, were analyzed using multivariate Time Series techniques. First the non-stationary time series was converted to a stationary series by using the "𝘥𝘪𝘧𝘧𝘦𝘳𝘦𝘯𝘤𝘦 𝘮𝘦𝘵𝘩𝘰𝘥". The Burg algorithm was used to fit an autoregressive model for the mean corrected data. The order of the model was decided by the minimum AICC. The Residual auto- correlation and cross-correlation graphs showed the suitability of the fitted model. After validating the fitted model, it was used to forecast the Temperature and Rainfall for the Colombo District up to year 2007. The results were also used to consider the existence of trends and any possible patterns which comply with the Global Warming effect. The average increase between the fitted values and the existing actual values was calculated, and this average effect was compared with the Global effect obtained by other researchers.
Water management in Walawe basin using system dynamics simulation modeling
(University of Peradeniya Sri Lanka, 2004-11-10) Nandalal, K. D. W.; Wickramaratna, N. S.
Walawe river basin, located in the south of Sri Lanka has a total drainage area of 2442 k.m2 and receives an average annual rainfall of 1750 mm. The water resources system in the basin consists of two major reservoirs, namely, Samanalawewa reservoir and Udawalawe reservoir, and other components such as irrigation schemes and power plants. The top most Samanalawewa reservoir on' the Walawe river supplies irrigation water to Kaltota irrigation scheme (880 ha) located just downstream of it, in addition to hydropower generation. The Udawalawe reservoir supplies irrigation water to downstream lands located on both banks of the river through right and left bank canals. This water passes through two small hydropower plants built at the Udawalawe dam. The total land area irrigated on the right bank is about 11400 ha while that on the left bank is about 6110 ha. Development of additional land for irrigation of about 5340 ha has been commenced on the left bank. The paper presents a model developed based on System Dynamics (SD) principles for the decision making for effective water resources utilization in the Walawe river basin. SD is a rigorous method of system description, which facilitates feedback analysis, usually via a simulation model, of the effects of alternative system structure and control policies on system behavior. Understanding of the system and its boundaries, identifying the key variables, representation of the physical processes or variables through mathematical relationships, mapping the structure of the model and simulating the model for understanding its behavior are the major steps that are carried out in the development of a system dynamics model. SD applications for water management decision making are rarely found. However, the SD model that incorporates the complexities and interaction among different activities in the Walawe river basin proves the usefulness of our modeling approach in terms of strategic decisions on water sharing to help all water-use sectors of the basin. The case of irrigation water supply with the new irrigation system development under the Udawalawe reservoir is compared to the present condition, and considerable water deficit is observed. However, additional water management scenarios, with possible crop diversification may be analyzed to draw better water management plans. Moreover, the model can be used to develop better operational rule curves for the reservoirs based on a large number of simulations.
Yield and nutritive value of two fodder grasses as affected by fertilizers
(University of Peradeniya, 2004-11-10) Himali, S. M. C.; Premalal, G. G. C.; Jayasekara, N.; Atapattu, I. K.; Premaratne, S.
An experiment was conducted to evaluate the effect of fertilizer on yield and quality of CO-3 (𝘗𝘦𝘯𝘯𝘪𝘴𝘦𝘵𝘶𝘮 𝘱𝘦𝘳𝘱𝘶𝘳𝘪𝘶𝘮 𝘹 𝘗𝘦𝘯𝘯𝘪𝘴𝘦𝘵𝘶𝘮 𝘢𝘮𝘦𝘳𝘪𝘤𝘢𝘯𝘶𝘮) and VRI-435 (𝘗𝘢𝘯𝘪𝘤𝘶𝘮 𝘮𝘢𝘹𝘪𝘮𝘶𝘮) fodder under mid country wet zone of Sri Lanka. The experiment consisted of four treatments namely, Tl - CO-3 without fertilizer, T2 - CO-3 with fertilizer, T3 - VRI-435 without fertilizer and T4 - VRI-435 with fertilizer. Treatments were arranged in a Randomized Complete Block Design with 3 replicates. Rates of inorganic fertilizer applied to CO-3 and VRI-435 were 322 kg N, 115 kg P₂0₅, 135 kg K₂0 /ha/yr and 230 kg N, 80.5 kg P₂0₅ and 90 kg K₂0 /ha/yr respectively. Nitrogen was applied in 9 splits. Cattle manure was applied at the rate of 15,000 kg/ha/yr. Other management practices were adopted as recommended. Plants were harvested for the first time at 45 days after planting and again 40 days after the first harvest and, fresh yield per plot was recorded. Sub samples were taken from each plot to determine the dry matter content and chemical composition of forages. Plants were harvested again after 40 days and same parameters were taken. Data were statistically analyzed using SAS package and means were separated using LSD. Application of fertilizer increased (p
Performance of rabbits as affected by type of grass
(University of Peradeniya, Sri Lanka, 2004-11-10) Himali, S. M. C.; Premalal, G. G. C.; Jayasekara, N.; Atapattu, I. K.; Premaratne, S.
A feeding trial was conducted in mid country wet zone of Sri Lanka to investigate the effect of different types I forms of grass on the performance of rabbits. Rabbits were selected (600 g ± 250 g) and housed in individual wire net cages. Age of the rabbits was 7 weeks ± 6 days. Twenty rabbits were selected and blocked (five blocks) according to the body weight. It was a Complete Randomized Block Design (RCBD) with four treatments and five replicates, Water was supplied ad 𝘭𝘪𝘣𝘪𝘵𝘶𝘮 throughout the experimental period. Diets were consisted of fresh grass or hay. Grass used were CO-3 (𝘗𝘦𝘯𝘯𝘪𝘴𝘦𝘵𝘶𝘮 𝘱𝘦𝘳𝘱𝘶𝘳𝘪𝘶𝘮 𝘹 𝘗𝘦𝘯𝘯𝘪𝘴𝘦𝘵𝘶𝘮 𝘢𝘮𝘦𝘳𝘪𝘤𝘢𝘯𝘶𝘮) or Signal grass (𝘉𝘳𝘢𝘤𝘩𝘪𝘢𝘳𝘪𝘢 𝘣𝘳𝘪𝘻𝘢𝘯𝘵𝘩𝘢𝘪) as fresh or in the form of hay. Treatments were as follows: Tl - 300 g of CO-3 fresh grass, T2 - 60 g of CO-3 hay, T3 - 300 g of Brachiaria fresh and T4 - 60 g of Brachiaria hay. In addition to forage or hay, each rabbit was fed with 50 g of broiler finisher. The trial was consisted of an adaptation period of one week, followed by a three days preliminary period and a 28 days collection period. Initial body weight of each rabbit was recorded at the beginning and once a week, thereafter. All rabbits were fed with the relevant diet between 9.00 to 10.00 a.m. throughout the experimental period. Feed offered, feces output and refusals were recorded daily and sub samples were taken for dry matter determination and for chemical analysis. Proximate compositions of feed samples were analyzed according to standard methods. Dry matter intake, weight gain, dry matter digestibility and feed conversion ratios were calculated using the above data. Data were statistically analyzed using the SAS computer package. Means were separated using the LSD test. No significant differences were observed between treatments for any of the parameters studied. However, intake of fresh grass was always higher (about 6 %) compared to any type of hay. The highest weight gain (140 g/week) and dry matter digestibility (73 %) were recorded in fresh Brachiaria grass compared to other treatments. However, values were not significantly different from each other. The lowest feed conversion ratio (3.9) was observed with CO-3 fresh grass and feed cost per kg of live weight was low (Rs 85/kg) with Brachiaria fresh grass. According to the results, CO-3 grass can replace Brachiaria as forage for growing rabbits and it is also economical to feed hay during the dry period
George Keayt's painting and its indianness
(University of Peradeniya Sri Lanka, 2004-11-10) Bandara, W.M.P.S.
George Keyt's paintings, as similar works of many others, have been subjected to criticism and appreciation on the basis of many theoretical constructs. His works have been analyzed and appreciated both in the light of Hindu Aesthetic and Philosophical concepts as well as European art forms. Some have traced the inspiration he drew to Buddhist paintings of both India and Sri Lanka and those of Hindu tradition as found in Khajuraho, Bbuwaneshwari and Konarak temples. The latter displays tantric practices of medieval Hinduism. (Sunil Goonesekera, Albert Dharmasiri) Some see parallels of European arts such as cubism, expressionism and impressionism in Keyt's paintings. However, when we consider the origin and transition of Keyt's paintings, such comparisons show that they take into consideration only some aspects of it. That could be seen only at a given time in the evolution of his craftsmanship. But my venture in the present study is to investigate for a theoretical basis that could accommodate all his paintings, both at the levels of analysis and appreciation of his art. Seeing the unity in diversity and universality in complexity is the main feature of Indian aestheticism. In my view, the theory of Rasa could playa major role in the analysis and appreciation of Keyt's art. Whatever the tradition, be it Buddhist, Tantric or Hindu, the major thread that connects all his painting appears to me to be the Indian theory of Rasa, which plays a dominant role as a background for all his paintings. In this paper I shall attempt to analyze the paintings of Keyt on the basis of their formal features and evaluate their aesthetic leanings on the basis of the Rasa theory mentioned above. I shall also make use of his poetical compositions to substantiate my view.
Urban geological problems in Ratnapura City, Sri Lanka
(University of Peradeniya Sri Lanka, 2004-11-10) Pallawala, P. M. D. W. D.; Pitawala, H. M. T. G. A.; Gunatilake, A. A. J. K.
Ratnapura city is situated in the wet lowlands of Sri Lanka. Urban area spreads over 20 square kilometers with a population of 46300. The inhabitants of the city face natural hazards like periodic flooding, land instability and number of other gee-environmental problems created by their activities. During high rainfall periods, more than 20% of the urban area is flooded as approximately 273 square kilometers of drainage basin accumulates around the city. According to government authorities, more than 15% of the urban area is under landslide risk. The scope of the study is to investigate the present hazards of Ratnapura city, their causative factors and to suggest feasible preventive and mitigatory measures. The investigation was carried out using available literature survey, maps, aerial photographs and field observations. Ratnapura city is surrounded by hillocks and Kalu Ganga that are strongly responsible for the present urban environmental hazards and as a result for slow development of the city. Flooding is the major hazard affecting the Ratnapura city as annual floods submerge over 15% of the Central BusinessDistrict (CBD). High outflow of Kalu Ganga near Ratnapura town due to regular high precipitation is the major reason. Present CBD of Ratnapura city has expanded to adjacent sloppy lands and it triggers the land instability which is further aggravated by structural geological conditions and secondary deposits like colluvium/weathered overburden on slopes. Also the environmental geological problems of the city are worsened by increasing population and poor land use practices especially in constructions near CBD and agriculture in the periphery of the city. In order to overcome the present situation, suitable mitigatory measures are crucial. Land use planning is an effective mid and long term remedial measure. Recently established administrati ve center at Hidellana must be further developed to facilitate the increasing population and to avoid geographical barriers of geologically unstable Ratnapura city. Appropriate building construction practices like piled apartments to suit sloppy lands and flood plains should be encouraged if the present town is going to be further developed. The engineering geological hazard map of the city area shows several geological factors which should be considered when contemplating land use in future constructions and agricultural work. The planners must consider the geology related hazard map prior to any ground-based development work in the city. However the development of Hidellana area must be encouraged as a new town because the area is geologically more favorable and stable than the present Ratnapura city.
Urban pollution into Polgolla Reservoir
(University of Peradeniya Sri Lanka, 2004-11-10) Herath, G. B. B.; Ratnayake, U. R.; Paranavithana, G. N.
Sri Lanka is endowed with rich water resources emanating from the central highlands that receive rain during the monsoons. These waters are carried radially from the central hills through 103 distinct river basins covering 90% of the island. Of these the Mahaweli River basin is the largest draining 16% of the country and carries water from the wet region to the dry region. As this water satisfies only a small region in the dry zone, the Mahaweli water is developed for many irrigation and hydropower Projects during the last 30 years by constructing as many as 5 major reservoirs across it. These Projects irrigate 364,000 ha in dry zone covering approximately 38% of the total land area of dry zone and generate more than 500 MW of hydropower. Few years after construction, all these reservoir waters are under direct pressures from agriculture, urban and industrial activities that changed the land use patterns within the catchments. In addition, excessive use of agrochemicals and chemical fertilizers release of domestic sewage and dumping of solid waste into the river cause indirect pressures. These pollutions collectively interact resulting in complex impacts on Mahaweli reservoirs. Out of the above, non-point pollution from urbanization and agricultural activities is believed to exert significant pressures on Mahaweli waters and lack of adequate waste disposal and management facilities for the increased urban population is said to have amplified the situation. Therefore to assess the current situation correctly, a study was initiated to quantify and characterize the potential risk level of non-point pollution into the Mahaweli river reservoirs from urban and agricultural land use changes. For this, initially three of the tributaries (Pinga Oya, Maha Oya and Nanu Oya) of Mahaweli draining into the Polgolla reservoir were investigated for diffuse pollution pressures from different land uses including agriculture, forestry, domestic, urban and industrial sectors. Wastewater discharges, fanning practices, field conditions and risks to watercourses were assessed on each of these catchments. GIS datasets of catchment characteristics were used to scale up and analyze the pollution at catchment level. Monthly river samples at over 20 locations were taken and analyzed for various pollutants such as nitrates, phosphates, BOD, DO, pathogens etc. Stream average DO decreased from 5 mg/l to 4 mgll and N0₃₋N increased from 0.5 mgll to 1.75 mgll during the study. Further, fecal coliform levels as high as 7500 pfullOOmI was measured. The study has clearly established that land use, particularly improper human settlements. intensive agriculture and geological formation strongly influence on the pollution. Analysing with the GIS data shows that as the case of most developing countries with very little large-scale industries, biological pollution due to human pollution especially on rainy days from non-point sources is the predominant factor. Low 00 values and high coliform counts indicate excessive biological contamination from human excreta. Further. unsatisfactory farming practices contribute a fair amount of nutrient load in the upper catchments and unless proper pollution control measures are implemented, eutrophic conditions in the reservoir would be inevitable.
Under-voltage problem in Sri Lanka: a case study
(University of Peradeniya Sri Lanka, 2004-11-10) Gajanayake, C. J.; Kumara, J. R. S. S.; Sana, M. K. M.; Atputharajah, A.; Fernando, M. A. R. M.
Under-voltage is one or a critical power quality issue in some of the power distribution networks in Sri Lanka. However. attention to these power quality problems and standards arc minimal. Therefore. most of the consumers face problems related to power quality. In this paper, a case study of under-voltage problem in the faculties of Agriculture (Agric) and Veterinary Medicine and Animal Science (Vet) of the University of Peradeniya are presented. Initially. a survey was conducted to collect the information related to the electrical installations at Agriculture and Vet faculties. Then, electrical measurements (voltage, current. power, power factor, harmonics etc.) were monitored at the main panels and sub-panels of the buildings of these facilities. This was done under normal load, which covered working hours. lunch break and weekends. The measurements were continued in all the buildings while loading gradually up to the possible full load. Two test set-ups: one using a clamp-on-power meter interfaced to a laptop and the other a power meter interfaced to a data logger were used to record continuous measurements in main panels and sub-panels respectively. The maximum full loads with requirements-based and socket outlet-based were estimated for all the buildings by assuming an overall power factor of 0.9 and diversity factor of 0.75. The whole system was simulated under maximum loading using IPSA computer package. It was found that the phase voltages of the administration building of the Agriculture Faculty reduced significantly (below 10%). The voltage in R phase was even 70% of the rated 230 V. However. the building consisting Departments of Biology. Soil and Food Sciences of the Agriculture Faculty had a stable normal voltage level since it was directly supplied from the transformer. The Animal Science buildings had voltage drops up to 12% of the rated voltage. The main building and the Department or Clinical Studies of the Vet Faculty also experienced some under-voltages. In general. these under-voltages art: due to unbalance loading and improper selection of LV cabling. However. the other buildings and transformer terminals were within acceptable limits. To improve the voltages at tile' Agriculture administration building. it was suggested to supply it directly from the transformer with a cable of the double sized cable and to balance the loads within the building. To improve the main voltages of the overall system. it was recommended to increase the voltage at the supply end of the transformer by 5% and to increase the size by a factor of two of main cables in the buildings which had experienced under-voltage (Department of Farm Animal Production and Health main building and Department of Veterinary Clinical studies of Vet Faculty). Replacement and modification or main panels of Animal Science old, Animal Science new, Vet administration and Vel Clinical are also recommended.
Yield enhancement of tube wells by hydrofracturing technique: a casestudy in Sri Lankan hardrocks
(University of Peradeniya Sri Lanka, 2004-11-10) Bandara, A. M. R.; Dharmagunawardhane, H. A.; Amarasinghe, Udeni
Over the last few decades, more than 20,000 tube wells have been constructed in the hardrock terrain of Sri Lanka for drinking water supply purposes. However, about twenty percent of these tube wells have failed due to inadequate yields. The design of a tube well in hard rock areas consists of two main components; a) A comparatively large diameter (165mm to 205mm) vertical drill hole, cased with a PVC casing in the weathered overburden from ground level to the rock, and b) A comparatively smaller diameter (104mm to 165mm) and unlined drill hole in the rock below the casing The depth of tube wells in hard rocks of Sri Lanka usually varies between 30 to about 100m with an average depth of 45m. Groundwater enters the tube well through the discontinuity planes such as joints, faults, lithological contacts or fractures that have been penetrated by the unlined drill hole. The yield of the tube well depends on the amount of groundwater percolating into the borehole through these structural discontinuities which in turn depends on their openness, intensity, interconnection and lateral extent. Filling of weathered materials in these joints and fractures some times reduce the flow of water in to the borehole. The hydro fracturing technique firstly involves isolation of a low yielding discontinuity plane in the rock within the un-lined hole using one or two inflatable packers. Then a very high pressure is applied by pumping water into the isolated joint or fracture zone using a high pressure water pump (600 l/minute at 1OO bars). When the pressure is increased gradually, it abruptly expands the openness of the joints and also develops new interconnections of previously non connected discontinuity planes. This is indicated at the surface as a sudden drop of the pressure in the gauges connected to the high pressure water pump. Under the present study, hydro fracturing technique was applied in 16 low yielding tube wells where the original yield was less than 17 l/minute, In 14 of these wells, the yield was less than 5 l/minute and eight were completely dry. The study revealed that the application of hydro fracturing for enhancing the yield was successful in more than 85% of the tube wells. Yield of the wells had improved to levels that they could be put into use as community water supply wells with hand pumps. Considering the cost of construction of a new tube well to replace an unsuccessful tube well in community water supply programs, it became evident that the vast majority of already drilled and failed tube wells in the country can be rehabilitated with the help of hydro fracturing technique. The present study is the first attempt of this type applied in the hard rock tube wells in Sri Lanka.
The women's ownership of land and property in the Pre-Colonial Period in Sri Lanka (from 3rd century B. C. to 15th century A. D.)
(University of Peradeniya Sri Lanka, 2004-11-10) Chandrika, M.
Many scholars who have analyzed the tenurial system in ancient Sri Lanka have- postulated that males were the owners of land and property. Among them H.W. Codrington, Wilhelm Geiger and M.B. Ariyapala are prominent. But in analyzing the inscriptions and other historical evidence of the pre- colonial era, it is revealed that not only males but females also owned land and property in the past. The objective of this study is to identify women's ownership of land and property in the pre-colonial period. There are several valuable studies about women in ancient Ceylon, but, they mainly examine the social status of women. They have not paid attention to the economic status and ownership of land and property directly. Therefore this study is of very great importance in understanding ancient society and its economy. Details of women's ownership of land and property can be analyzed under the following headings. 1. Ownership, of caves 2. Ownership of monastic establishments 3. Ownership of fields, irrigation tanks, villages etc. In examining details of women's ownerships of land and property, my research has taken into account women's social status. Most of the available evidence illustrates that donations for meritorious or public purposes have been made by women of higher social status, such as, queens, princesses, and mothers, daughters or wives of men of standing. In addition these categories of women also participated in various other economic activities. However, my research will attempt on the basis of the available evidence, to examine land and property rights of women of both upper and lower social status. Apart from donations and grants my research will also attempt to examine the concept of ownership, sale and other forms of alienation of property by women during this period.
Water quality modeling in Kotmale reservoir
(University of Peradeniya Sri Lanka, 2004-11-10) Nandalal, K. D. W.; Abeysinghe, K. G. A. M. C. S.
Kotmale reservoir is the uppermost reservoir in the Mahaweli water resource development scheme in Sri Lanka. Though hydro-energy generation is its prime purpose, it acts as a storage reservoir in the satisfaction of downstream irrigation water requirements, too. Its total storage capacity is about 172x10⁶m³ while the height of the dam is about 87m. The Kotmale reservoir faced several water quality related problems in the recent past. During a severe drought in 1991, the reservoir water level dropped and a thick bloom of Microcystic aeruginosa was observed in the upstream region. This shifted towards the dam due to wind action covering the whole surface of the reservoir This paper presents modeling of water quality in the Kotmale reservoir to predict water quality in it, which enables taking precautionary measures in such situations. The collection of water quality data within a reservoir is very expensive and therefore, the ability to predict water quality, by a model would be very valuable. . A coupled hydrodynamic-water quality model, DYRESM-CAEDYM, was calibrated and validated for the Kotmale reservoir. The component, DYRESM is a one-dimensional hydrodynamic model for predicting the vertical distribution of temperature, salinity and density in lakes and reservoirs. The other component, CAEDYM is a complex ecological model containing process descriptions of primary production, secondary production, nutrient and metal cycling, oxygen dynamics and the movement of sediment. DYRESM-CAEDYM couples these two models, resulting in a powerful tool to investigate the interactions between physics, chemistry and biology in aquatic ecosystems. The model requires a series of input data that include the meteorological conditions (air temperature, relative humidity, wind velocity, solar radiation, rainfall, evaporation), inflow quantity, inflow quality and outflow quantity over the period of simulation in addition to initial vertical distribution of all the simulated state variables. The model DYRESM-CAEDYM was able to predict water quality in the reservoir and released from the reservoir. The model was configured to simulate water level, temperature, salinity, density and 5 water-quality constituents (DO, N0₃, NH₄, PO₄, pH). The model reasonably reproduced the seasonal and spatial patterns of water-temperature, dissolved oxygen, nitrate, ammonia, orthophosphorus and pH. To predict reservoir water quality, the model needs only the inflow water quality, which can be measured easily and inexpensively. If adverse water quality conditions are predicted, precautionary measures that could be taken can be studied with the help of the model. The calibrated model is a useful tool to manage the Kotmale reservoir to avoid adverse water quality conditions in the reservoir as well as supplied from it.
Study of the causative factors for the occurrence of Illukpotha landslide at Kalawana
(University of Peradeniya Sri Lanka, 2004-11-10) Kudahetty, Chamindi; Gunathilake, Jagath
Extremely intense rainfall occurred on 17ᵗʰ May 2003 in the Ratnapura district of Sri Lanka triggered one of the worst natural disaster of the country in the recent past. As a result of the extreme rainfall, landslides and widespread slope failures took place in the hilly areas in the Ratnapura, Kalutara, Matara, Galle and Hambanthota districts. Total of 316 landslide have been reported in the Ratnapura district itself. Among these landslides, IlIukpotha (Pothupitiya Kanda) landslide at Kalawana is the largest landslide occurred in the recent past. It covers approximately one square kilometers area and occurred as a debris flow, taking two paths along the existing valleys. This devastated landslide has been reported to be occurred on 17ᵗʰ May 2003 at 5.45 pm, killing 7 people and destroying 8 houses. This paper deals with the causative factors for occurrence of the Illukpotha landslide, which is located near the 21 km post on the Kalawana-Pothupitiya road in Ratnapura district. The field investigation revealed that this debris flow occurred due to a combination of natural and man-made causes. The extensive precipitation of over 500rnm per day (occurred within 7-8 hours of the day) has become the triggering factor of this landslide, which later converted into a devastative debris flow. IlIukpotha landslide has been initiated due to the saturation of fault zones (N 70°- 80° E and N 40° W) at the crest of the landslide as a result of the extensive infiltration of this rainwater. The underlying geological formation (weathered garnatiferrous charnockitic gneiss with relatively thick clay bands and pegmatite), extensive joint systems (parallel to the above fault systems), fault planes with thin clay seams, slope angle (approximately 35°), and deeply weathered overburden (2-4m thick) were playing a major role. The exposed bed rock along the slope shows the existence of complex folding structures associated with the axial area of the major Potupitiya antiform. General strike of the rocks (succession of charnockitic gneiss, granulitic gneiss, and biotite gneiss) is at East-West direction and except for the landslide initiation area, the whole debris flow is occurred along the dip slope. The landscape features identified on the pre-landslide aerial photographs provide evidences for the occurrence of historical landslide along the slope concerned. More over it was clear that the improper cultivation practices (cultivation of tea introducing horizontal drains in former forest land) on the steep hill slopes at this area, have further accelerated the infiltration rate. Therefore, it could be concluded that the fundamental causative factors for occurrence of the Illukpotha landslide were; continuous excessive precipitation within a short period of the day, existence of the faults, and prominent rectangular joint pattern, deeply weathered thick overburden and the change of land use from forest to tea cultivation.
A study on cardiotoxin of Sri Lankan Cobra
(University of Peradeniya Sri Lanka, 2004-11-10) Ranasinghe, J. G. S.; Suzuki, M.; Athauda, S. B. P.; Perera, P. A. J.; Moriyama, A.
Sri Lanka has the highest fatality rate of snakebites in the world. The cobra (𝘕𝘢𝘫𝘢 𝘯𝘢𝘫𝘢 𝘯𝘢𝘫𝘢) is one the most dangerous species in the Indian subcontinent. Anti venom serum (AVS) is the only effective therapy available for treatment of snake bite. Anaphylaxis can be fatal unless emergency treatment is given. At this juncture, it is worthwhile to investigate the composition of the toxins of Sri Lankan cobra and find out their homogeneity to Indian species. In this study, venom was collected from captured cobras reared at the reptile facility in the Faculty of Medicine, University of Peradeniya. Crude venom was purified by chromatographic met;hods and the purified product was subjected to protein sequencing. The cardiotoxin of Sri Lankan cobra which is responsible for tissue reactions and haematological changes after envenomation was analysed. In order to clarify the structural relationship among them, amino acid sequence of cardiotoxins determined in this study were compared with those of cardiotoxins already reported in other cobra species. The amino acid sequences of the cardiotoxin, present in the Sri Lankan cobra is different from other Asian cobras. It is much closer to 𝘕𝘢𝘫𝘢 𝘯𝘢𝘫𝘢 𝘰𝘹𝘪𝘢𝘯𝘢. This study supports the view that there are genetical differences between the Sri Lankan and Indian cobra species. It is beneficial to analyse the major toxins of our endogenous snakes and produce anti venom specific to our species in Sri Lanka, thereby helping to reduce the high fatality due to snakebite.
Super-elevation of flow in channels of nonlinear alignment
(University of Peradeniya Sri Lanka, 2004-11-10) Wijethunga, J. J.
The presence of curves or bends in alignment is unavoidable in the design of open channels. However, the flow at a bend is quite complicated due to the presence of spiral currents,cross-waves and also the super-elevation of the water surface. The difficulties in the designof channels of nonlinear alignment often arise due to the paucity of information on the reliabilityof the theoretical formulae available in the literature for the estimation of the super- elevationof flow at bends. In this backdrop, the primary objectives of the present study are: i) to improve our understanding of the flow behaviour at bends, and, ii) to examine the reliabilityof the theoretical formulae mentioned above, through an experimental investigation of the flow in channels of nonlinear alignment over a range of the relevant dimensionless parameters. The experimental work was carried out in a 6 m long masonry open channel consisting of a 60°- bend with a radius of curvature of 0.75 m. The original width and the height of the channel were 310 mm and 350 mm, respectively, whilst the channel slope was 0.02. Subsequently, the width, the height and the slope of the channel were changed to obtain measurements over a wider range of the relevant dimensionless parameters. Further, the velocity measurements were made using a 20 mm diameter propeller meter equipped with a digital counter. The measurements have been compared with the following semi-empirical formulae that are available to estimate the super-elevation. In these formulae, 𝘣 is the width of the channel; 𝘨 is the acceleration due to gravity; 𝘳 is the radius of curvature of the bend with the subscripts 𝘤, 𝘪 and 𝘰 denoting centre, inner and outer, respectively; 𝘝 is the flow velocity; and Δ𝘏 is the super-elevation of the flow. [The abstract includes mathematical functions and symbols.] The results indicate that the measured values of Δ𝘏 are closer to equations (1) and (2), whilst equation (3) under-predicts the measurements by about 50%. Therefore, it appears that equations(I) and (2) are more reliable than equation (3) in estimating the super-elevation. The way in Δ𝘏/𝘣 varies with 𝘥/𝘣 (𝘥 is the water depth) for different values of 𝘳/𝘣 has also been examined, and it appears that the general trend is for Δ𝘏/𝘣 to increase with increase of 𝘥/𝘣.

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