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Estimation of leachate from a pilot scale lysimeter
Get PDFThe most important component of solid waste management is long-term safe and reliable disposal of solid waste in sanitary landfills. Leachate formed in landfills needs proper management. The biodegradable portion of waste is largely responsible for the production of leachate and landfill gas. This paper presents the outcome of the research on the water management of landfill in Nepal using a designed and built pilot scale field lysimeter model. The leachate production from the lysimeter as an effect of climatological factors is assessed. The Hydrologic Evaluation of Landfill Performance (HELP) model is used to compute estimates of water balances. Simulation of the model indicates that the evapotranspiration (ET) is nearly constant and do not follow the precipitation and percolation trend. Also the evapotranspiration component in this case, is not high. This may be due to the small surface area of lysimeter and larger portion of the leachate percolated before evaporation could take place. The model has been calibrated for the local situation with the limited observed data of leachate generation from the lysimeter. However the trend of leachate generation on HELP simulation and Actual Data seem to be similar during month of October to December season, but during June to September, the trend shows higher actual percolation rate compared to the model output. This may be due to the higher value of permeability of barrier soil (in the range of 10-5 cm/s), which should be generally in the range of 10-7 cm/s or lower. The rainy season during June to September may be another reason, when soil is wet most of the time. The annual data shows that percolation is about 81-84% of precipitation amount, whereas evapotranspiration is about 15-19%. The application of the model may be a valuable tool to determine strengths and weaknesses of designing and operating of landfills in developing countries like Nepal.
Kathmandu University Journal of Science, Engineering and Technology Vol. 8, No. II, December, 2012, 93-100
DOI: http://dx.doi.org/10.3126/kuset.v8i2.733
Conformational, Chemical Reactivity, Thermodynamic Properties, and the SEM Study of Yohimbine Hydrochloride
Get PDFWe have presented a study on structural conformation of yohimbine hydrochloride using density functional theory (DFT) method. A short description about the surface morphology with scanning electron microscopy imaging has been included. Correlation between different thermodynamic properties with variation in the temperature has been given. The global and local chemical reactivity descriptors have been calculated, from which nucleophilicity and electrophilicity of the given atomic sites in the molecule can be known
Fixed Point Theorems for Occasionally Weakly Compatible Maps in G-Metric Space
Get PDFIn this paper, we prove common fixed point theorems for a pair of occasionally weakly compatible maps in Symmetric G-metric space. Our results generalize and extend several relevant common fixed-point theorems from the literature
A Result in Dislocated Quasi Metric Space
Get PDFIn this paper, we prove a fixed point theorem in dislocated quasi-metric space which extends and unifies some well-known similar results in literature
Common Fixed Point Theorem on Cone Banach Space
Get PDFThe aim of this manuscript is to discuss some fixed point results for self mappings satisfying certain contractive conditions on Cone Banach space
Some Common Fixed Point Theorems in Menger Spaces Using Occasionally Weakly Compatible Mappings
Get PDFIn this paper we prove some common fixed point theorems for family of occasionally weakly compatible mappings in Menger space. Also improvement of the results of B. D. Pant and Sunny Chauhan [1] under relaxed conditions is given. 
Optimum Use of Renewable Energy Resources to Generate Electricity via Hybrid System
Get PDFThe necessity of a hybrid energy system is gaining more importance day by day as it incorporates two or more renewable energy resources that, when integrated, overcome limitations inherent in either. A hybrid energy system has been seen as an excellent solution for the electrification of rural places where grid extension is difficult and economically not feasible. Such systems may consist of several renewable resources such as solar PV, wind, biomass, micro-hydro, geothermal, and other conventional generators for backup, where the deficiency of one system can be compensated by others. This paper depicts the different system components and their optimal combination for the efficient generation of electrical energy exploiting locally available resources. The model discussed in the paper comprises micro-hydro, solar PV, and biomass for the rural village in Nepal known as Kalikhola, which is used as a case study. The optimized hybrid system shows a unit cost of $0.088/KWh, which is obtained after the simulation considering the contribution of individual renewable resources participating in the system
Assessment of Microbial Quality of Chlorinated Drinking Tap Water and Susceptibility of Gram-Negative Bacterial Isolates towards Chlorine
Get PDFSixty (56.1%) water samples crossed the permissible limit of WHO guideline value in heterotrophic plate count and total coliform count each. Ten different genera of gram-negative bacteria were recovered, among which E. coli was predominant followed by Citrobacter spp., Shigella spp., Enterobacter spp., Providencia spp., Klebsiella spp., Salmonella spp., Pseudomonas spp., Proteus spp., and Edwardsiella spp. Higher the temperature of water sample, higher the bacterial growth was obtained (p= 0.002), and similarly, a higher level of free residual chlorine in water reduced the bacterial growth (p= 0.037). However, increase or decrease of pH (p= 0.454), turbidity (p= 0.164), and conductivity (p= 0.969) didn't affect the microbial growth. A negative correlation (r= -0.162) between heterotrophic plate count and free residual chlorine was observed, but without statistical significance (p= 0.096). Similarly, a negative correlation (r= -0.383) between total coliform count and free residual chlorine was observed with statistical significance (p= 0.001). In the chlorine assay, all tested eight different genera of gram-negative bacteria were found to be chlorine resistant at 0.2 mg/L for a contact time of 30 minutes. The average time required for T99.9 (3-log) and T99.99 (4-log) reduction of viable isolates from the initial population of 2×106 cells/mL were found to be less than 30 minutes and greater than 60 minutes respectively. Log inactivation of various bacterial isolates with a chlorine concentration of 0.2 mg/L for a contact time of 30 minutes ranged from 3 to 3.5-log. The emergence of chlorine-resistant organisms in drinking water probably demands alternate disinfection or mitigation strategy
Transient Thermal Model of Airflow Effects in Human Eye Temperature
Get PDFHigh air speed makes thinner the thermal boundary layer between cornea and environment. This accelerates evaporation of water and convective heat transfer. Both factors drop corneal temperature. Most of the literatures of thermal modeling in human eye air forced convection effects is not considered. Based on different climatic conditions of Nepal and their impact on two-wheeler rider's eye, one dimensional variational finite element model is developed to investigate the forced convection effects of airflow in eye temperature distribution. The bio-heat transfer process is simulated in transient state cases. The results show that, high air speed decreases corneal temperature rapidly in cold climate but there is no significant decrease found in hot climate. The corneal temperature starts to plateau from approximately same time at same air speed and in different ambient temperature
Biobriquetting in Nepal - Scope and Potentials: A Review
Get PDFNepal still relies heavily on traditional sources of energy for cooking, heating, and livestock feeding. In search for alternatives to fuel wood and utilization of waste biomass, briquetting was introduced in 1982 by the private sector to produce charred rice briquettes and rice husk briquettes in 1987. A close analysis of the situation during the 1980s reveals that the entire briquetting efforts came from the private sector, without any government support in terms of policies, incentives, and motivation. Also, there was no technical backstopping and very little R&D to support briquetting. So because of various techno-economic problems, most of the briquetting industries closed down. The situation in the country after 2010, nearly thirty years later, is entirely different. With the increase in awareness about briquettes as a renewable source of energy, climate change, and global warming issues from fossil fuel use, and the concept of utilizing waste for energy, along with the change in kerosene and briquettes fuel prices, briquettes are slowly emerging as a viable alternative source of energy for cooking and heating. Many briquetting industries are again being established in the private sector. The Nepali experience on briquetting shows that almost all of the biobriquetting technologies have been introduced in the country. R&D institutions have emerged, and research and development activities supporting biomass briquetting are constantly increasing. The assessment of agro-forest waste shows that there is a huge raw material base that can be utilized for briquetting. The technological capability in fabrication, reproduction, repair, and maintenance has been well developed. Many funding, promotional, and R&D organizations are now actively involved in briquetting. The Government through the Alternative Energy Promotion Centre (AEPC) is formulating policies, plans, and programs, including incentives for the promotion of biobriquetting. With the introduction of proper policies and incentives, biomass briquetting has big potentials and scope for the promotion of biobriquettes in the near future