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Pressure Distribution at Inner Surface of Selected Pelton Bucket for Micro Hydro
Get PDFFour different Pelton bucket contours have been designed at Kathmandu University, namely DB01, DB02, DB03, and DB04. The primary aim of this study is to provide a detailed experimental analysis of the pressure distribution in these four different bucket contours, along with comparison to the commonly used ITDG bucket contour. The head and flow rate have been maintained constant during the test period. The pressure distribution around the inner surface of the bucket has been measured at three different angles of the bucket to the jet incidence: 0 degrees (normal to the jet), +15 degrees (incline away from the jet), and -15 degrees (incline towards the jet), considering extreme contact conditions by the jet. The test has been carried out for the stationary bucket. The pressure is measured in 20 orthogonal grid points of size 10mm x 10mm. The bucket is drilled normal to the surface on each pressure intake points. Fine copper pipes of 5mm diameter are fitted from the external surface of each orifice as pressure taps. Transparent PVC pipes are fitted to each pressure point for measuring pressure head in terms of water height. The bucket DB02 with elliptical section has been found with uniform pressure distribution. This profile had shown better performance in terms of torque. The pressure distribution inside the bucket DB02 has matched the flow pattern
A Common Fixed Point Theorem in a Cone Metric Space
Get PDFA common fixed point theorem for a pair of weakly compatible mappings is proved in a cone metric space which extends and improves various well-known similar results.
 
Thermal Induced Microstructures of KOH Etched Silicon Surface
Get PDFAnisotropic KOH etching of silicon for the fabrication of Micro-electro mechanical system (MEMS) part is based on surface finish and angular dependence of etch rate, creating thin diaphragm. The absolute values of orientation dependent etch rate is found to vary with thermal agitation. In this work, experimental results of etch rate is found quite consistent with simulated and are justify with their unusual values of activation energy along different planes. The various sites that an atom can occupy are not equivalent of their energy; some are more favorable to removal than others. In this paper attention is given to demonstrate thermal activation energy is the prime parameter that influences the behavior of etching mechanism as well as AFM surface morphology. Low-voltage contact mode atomic force microscopy (AFM) has been employed to analyze the morphology of the etched silicon surface at relevant different temperature. A systematic variation in morphological growth leads to stabilized surface structure under the influence of associated activation energy is concluded
Volatile Organic Compounds of Medicinal Values from Nepalese Acorus calamus L.
Get PDFThe volatile organic compounds (VOCs) from the rhizomes of Nepalese Acorus calamus L. were isolated using the simultaneous distillation–extraction (SDE) technique and subsequently analyzed via gas chromatography–mass spectrometry (GC-MS). A total of fifty-three VOCs were identified, belonging to various chemical classes including alcohol (11), aldehyde (14), ester (3), furan (1), hydrocarbon (19), ketone (4), N-containing, miscellaneous (1). The yield of volatile compounds obtained from the rhizomes of A. calamus was found to be 7493.59 mg/kg. Several bioactive compounds were identified, including β-asarone (46.78%), [E,Z]-2,4-decadienal (14.15%), linalool (0.41%), farnesol (11.09%), methyleugenol (6.10%), α- and β-pinene (both 0.06%), [E]-caryophyllene (0.11%), β-elemene (0.39%), ocimene (0.7%), aromadendrene (0.26%), and camphor (0.03%)
Indigenous Knowledge on Ethnobotanical Plants of Kavrepalanchowk District
Get PDFEthnobotanical knowledge is common and important among the tribal people but much of the information is empirical at best lacking logical validation. A number of ethnic communities residing in the study area are partially or fully dependent on the forest resources to meet their requirements. The present study analyses indigenous knowledge of ethnobotanical plant species and utilization of 68 species belonging to 59 genera under 37 families in day-to-day life of ethnic communities of Kaverpalanchowk district of central Nepal. The diverse ethnic communities such as Tamang, Newar, Magar, Chhetri, Pariyar, Biswakarma, and Tolange have a good association with plants and their potential role they use for different purposes; treatment of various ailments, economic and other values, and worship in different religions and customs. The traditional knowledge on the utilization of these ethnobotanical plants is widely accepted by these indigenous people
A Study of Livestock Management Patterns in Sagarmatha National Park, Khumbu Region: Trends as Affected by Socio-Economic Factors and Climate Change
Get PDFThe landscape of Sagarmatha National Park (SNP) evolved under centuries of livestock grazing and farming activities of the Sherpa people. This study attempts to determine changes in livestock population and composition, and explore major driver of changes in the six major year-round settlements in SNP that will be helpful to introduce management interventions for sustainable level of farming in the Park. The necessary data are collected through questionnaire survey. The study indicates that the total number of livestock in Khumbu has not declined, but their type and distribution have changed in each settlement over time. The male cattle breeds are increasing as these animals are used as pack animals and make twice the income of a human porter. However, female cattle breeds are declining because of the meager returns. Likewise, the number of livestock is comparatively less in places like Namche and Khumjung which are on the main tourist route, while in places like Forste and Thamicho where tourism flow is comparatively less, livestock number is high. As tourism created many employment opportunities with substantial income, people are gradually scaling down yak farming. Though tourism is the main driver of changes in livestock patterns, there are other socio-economic factors like education, prestige, political change, and globalization which have modified the animal husbandry practices. Increasing atmospheric temperatures, changes in precipitation patterns, and increased frequency of extreme weather events are the climatic changes seen in the area which are the result of climate change. But the socio-economic factors have actually outweighed the impacts of climate change on livestock in the area. However, as global warming continues, changing climatic patterns could possibly affect high altitude indigenous breeds like yak by creating shortage of water, fodder and increase in pests and diseases
Assessing Evolution and Biodiversity in Plants at the Molecular Level
Get PDFDNA sequencing and fingerprinting methods for the analysis of plant evolution and diversity have been in use for over two decades. Thousands of research reports have been published which have provided insight not only into the evolutionary pathways of plant species but also into the evolution of several genetic loci. This review highlights several articles that have made use of nuclear and chloroplast loci to investigate plant phylogeny and the evolutionary processes that have led to the current distribution and diversity of plants
Electrical Characterization of Atmospheric Pressure Gaseous Discharge
Get PDFThis paper reports the generation of atmospheric pressure gaseous discharge and its electrical characterization. For this purpose, a point-plane electrode system has been fabricated. A high voltage power supply (0-11 kV, 50 Hz) was applied across the electrodes. Discharge was generated with and without the dielectric barrier between the electrodes. The gas discharge was seen as in-homogenous filamentary type discharge without the dielectric. Whereas the filamentary discharge turned into bluish glow when the lower electrode was covered by a dielectric. The current and voltage of the discharge were measured by using a high frequency digital oscilloscope. The power consumed by the discharge was measured from the measured values of current and voltage. A special attention has been paid to investigate the effect of electrode geometry on the nature of the discharge
Key words: Gaseous discharge; point-plane electrode; dielectric material; filamentary discharge; current and voltage measurement
DOI: 10.3126/kuset.v4i1.2887
Kathmandu University Journal of Science, Engineering and Technology Vol.4, No.1, September 2008, pp 81-8
Heavy Metals and Safety of Fresh Fruits in Bangalore City, India - A Case Study
Get PDFUrban food security in India is a matter of growing concern. It is estimated that by 2005, 60% of India's population will be living in urban areas. The presence of heavy metals in human body always draws scientific concern as these are considered responsible for affecting health, especially in these days where the release of toxic wastes in the environment has been increased. The increasing trends in food contamination in urban areas are largely attributed to the polluted environment in urban agriculture, contaminated food transport and supply chains; poor market sanitary conditions, and the use of contaminated or waste water for irrigation purposes. The objectives of this paper to measure the levels of heavy metal contamination of fruits in Bangalore markets and assess how the heavy metal contamination might have impacted food safety standards vis a vis heavy metals on urban consumers. The results show that urban consumers are at greater risk of purchasing fresh fruits with high levels of heavy metals beyond the legally permissible limits as defined by the Indian Prevention of Food Adulteration Act, 1954. It must be noted here that these norms are less strict than international food safety norms like Codex Alimentarius or European Union standards. It is therefore suggested here that care should be taken in the following: reduce pollution at water source points; improve post harvest handling; enhance better coordination in fresh crops trading system to improve food safety standards; improve sanitary conditions for the city food markets; and increase awareness in consumers and policy makers on the dangers of heavy metal contamination in the food intake.
Keywords: Heavy metals; Prevention of Food Adulteration Act; Atomic Absorption Spectrophotometer (AAS)
DOI: 10.3126/kuset.v4i1.2880
Kathmandu University Journal of Science, Engineering and Technology Vol.4, No.1, September 2008, pp 17-2
Formulation of Once a Day Controlled Release Tablet of Indomethacin Based on HPMC-Mannitol
No full textp>A hydroxypropyl methylcellulose (HPMC K4M, HPMC K15M, and HPMC K100M) matrix tablet containing Indomethacin along with mannitol was formulated as a function of HPMC viscosity, and was compared with the commercial products. The release characteristics of the matrix tablet were investigated in the intestinal fluid, 6.8 pH phosphate buffer for 12 hours. The formulated products and two marketed products as reference sample were studied for its different physicochemical parameters and in vitro dissolution studies. It was found that the drug release profile decreases with increase in viscosity of polymer and, with increase polymer level in the formulations. Matrix tablets formulated employing Drug:HPMC K15M:mannitol::1:0.25:1 and Drug:HPMC K15M:mannitol::1:0.25:2 gave slow release of indomethacin spread over 12 hours and their dissolution profiles were compared with the Indian marketed product. The dissolution profiles of both the formulations were similar to the dissolution profile of the marketed product, the similarity factor being 74.59 and 68.04 respectively. The dissolution profiles of formulations containing same viscosity grade of HPMC in remarkably different concentrations and different viscosity grade of HPMC in same concentrations were different.
Key words: Indomethacin; Controlled release; Hydroxypropyl methyl cellulose; Mannitol; Dissolution.
DOI: 10.3126/kuset.v4i1.2884
Kathmandu University Journal of Science, Engineering and Technology Vol.4, No.1, September 2008, pp 55-6