Enhancing Energy Use Research Articles

HOW DOES THE DIGITAL ECONOMY AFFECT ENERGY EFFICIENCY?

As a new way of promoting high-quality economic development, whether the digital economy can enhance energy use efficiency by improving resource allocation is of great practical significance to global energy conservation and emission reduction efforts. This research employs principal component analysis and slacks-based measure data envelopment analysis in a case study of 30 provinces in China between 2014 and 2020 to evaluate the digital economy and energy efficiency. The analysis explores how the digital economy impacts energy efficiency, considering direct impacts, mediating effects, and their nonlinear relationship. The findings indicate a declining trend in China’s energy efficiency before it starts to moderate. The digital economy can boost energy efficiency by encouraging industry upgrades and reducing labor mismatches. The threshold regression model reveals that when the capital mismatch level exceeds 0.8871, the digital economy adds considerably to energy efficiency. The study’s findings confirm the linear and nonlinear energy efficiency impact trajectories of the digital economy, offering useful references for sustainable development policymaking.

AI-Enhanced Demand Response Strategies in Smart Grids: Toward Sustainable Energy Future

To accomplish a sustainable energy future, this article researches the consolidation of computerized reasoning (AI) into request reaction components inside smart grids. While considering the joining of sustainable power sources and expanding energy utilization, current energy frameworks depend altogether on load the executives and continuous energy request reaction. Conventional methodologies battle with the intricacies of dynamic energy situations. Results from the examination feature the worth of AI and ML for enhancing energy use. Versatile learning for energy proficiency, exact interest determining, continuous observing, and sustainable power source mix are completely made conceivable by these innovations. An intensive vision for the Smart Lattice is introduced, underscoring financial matters, proficiency, wellbeing, ecological obligation, security, and reliability. We check out at the benefits and downsides of incorporating energy stockpiling gadgets and the job of circulated framework insight. The determination gives a careful future vision to AI-enhanced request reaction in smart grids by featuring research issues connected with self-learning frameworks, complete robotization, self-recuperating grids, fitting and-play advances, network safety, and labor force improvement.

Thermoelectric Optimization of Integrated Energy System Based on Bidirectional Electricity-to-Hydrogen Technology

Abstract Addressing the challenges of high energy consumption and low efficiency in integrated energy systems, this research develops an optimal scheduling strategy that takes into account the dynamic operational conditions of the system and the complementary nature of electricity, hydrogen, and heat energies. Through the innovative application of variable efficiency gas turbines and solid oxide batteries, our model adeptly converts between these forms of energy. Moreover, we introduce a demand response strategy that seeks to balance efficiency with low-carbon generation and integrates a tiered carbon trading scheme to influence user electricity use and curb system-wide carbon footprints. Empirical results validate the effectiveness of our method in significantly enhancing energy use efficiency, cost savings, and emissions reductions.

Enhancing energy use efficiency of wireless sensor networks using newly proposed fault tolerance multipath routing protocol (MRP-FT)

The present study compared the newly proposed fault tolerance multipath routing protocol (MRP-FT) under the particle swarm optimization-based fault tolerant routing (PSO-FT) technique to the existing low-energy adaptive clustering hierarchy (LEACH) protocol applied in different combinations of inter-node numbers (N ) ranging from 100 to 300 nodes (N100−300) in wireless sensor networks (WSNs) with different area sizes (Xm × Ym) of 100–1000 m2 (WSN100−1000) to enhance energy efficiency and reliability of WSNs. The implementation of MRP-FT protocol significantly decreased the packet overhead by 36.0–69.5%, delay by 40.4–52.9%, and energy consumption by 35.9–52.9%, while increasing reliability by 97.0–104.1%, compared to the existing LEACH protocol. For instance, at N100−200, the LEACH simulated packet overhead increased from 76-89 packets at t = 500 s with an increase in WSN size from 100 to 1000. At N300 + WSN100, the packet overhead showed the highest decrease of ca. 69.5% with MRP-FT over the LEACH protocol. The implementation of the MRP-FT protocol reduced energy consumption by 35–123 J over the LEACH protocol.

Uso de lecitina integral de soja em dietas com concentrado energético de fontes amiláceas ou lipídicas para novilhos

ABSTRACT Diets with high energy density and additives that enhance energy use are necessary for finishing feedlot cattle. The objective of the present study was to evaluate the performance, ingestive behavior, apparent digestibility of the diet and the carcass traits of feedlot steers fed concentrates from different energy sources, one derived from starchy sources and the other, from lipid sources, combined or not with whole soy lecithin, at a dose of 40 g animal day-1. The experimental design was completely randomized blocks, in a 2 x 2 factorial arrangement. The combination of whole soy lecithin with the lipid energy source concentrate increased the dry matter digestibility and the carcass yield of the animals (76.03% and 57.20%, respectively). The lipid energy source concentrate showed higher ether extract digestibility and animals fed on it had higher carcass yield (84.18% and 56.85%, respectively). Whole soy lecithin promoted a reduction in fecal pH due to a greater fermentation of carbohydrates and fatty acids in the intestinal lumen. Using whole soy lecithin combined with energy concentrate from a lipid source is recommended due to its improvements in the use of the diet and in the carcass yield.

Maize/Peanut Intercropping Reduces Carbon Footprint Size and Improves Net Ecosystem Economic Benefits in the Huang-Huai-Hai Region: A Four-Year Study

The dual challenges of global climate change and reductions in the amount of arable land represent growing threats to the stability of global human populations. Efforts to further optimize cropping systems to maximize yields while minimizing greenhouse gas emissions in limited land areas have thus emerged as a focus in modern agriculture. Cereal-intercropping management strategies may represent a promising approach to simultaneously addressing both of these challenges in China. We aimed at comprehensively assessing changes in yield, carbon footprint, and net ecosystem economic benefit when transitioning from maize/peanut monoculture to intercropping in a field-scale study in an effort to aid in the development of low-carbon intercropping systems that do not have an adverse impact on Chinese grain yields. Beginning in June of 2018, a randomized complete block design with three treatments was used to initiate this study: (1) peanut monoculture (P), (2) maize monoculture (M), and (3) maize/peanut intercropping (MP). We compared yield, greenhouse gas emissions, carbon footprint and net ecosystem economic benefit. Results over four years showed that the land equivalent ratio associated with MP was greater than 1. All three of these cropping systems were net CO2 and N2O sources as well as net CH4 sinks, with MP generating significantly (p < 0.05) lower N2O and CO2 flux as well as smaller seasonal N2O and CO2 emissions relative to M. MP additionally reduced the carbon footprint associated with this cropping system by 11.11–31.65% and 30.37–43.62% relative to M and P, respectively. Consistently, MP treatment resulted in respective 70.69% and 26.25% net ecosystem economic benefit (NEEB) increases relative to the M and P conditions while simultaneously enhancing energy use efficiency. In summary, MP systems have potential economic benefit with lower environmental risk alternative to traditional peanut or maize monocropping systems. Converting from peanut or maize monocropping systems to MP systems practices contributed to improved farmland use efficiency, clean production and increased farmers’ income in an agricultural system.

Does structural transformation in economy impact inequality in renewable energy productivity? Implications for sustainable development

Since the global economies are in pursuit of achieving the 2030 Sustainable Development Goals (SDG) agenda, it has become pertinent to undergo an energy transition and enhance energy use efficiency in tandem. This is creating a disparity in the renewable energy generation, which is arising out the structural transformation of the economies. Against this background this study aims to assess the impacts of structural transformation on inequality in renewable energy productivity across selected OECD countries between 1990 and 2019. This study is important from the perspective that due to inequitable economic growth trajectory attained by the OECD nations, the renewable energy consumption levels of the OECD nations display significant amount of disparity which can also be reflected in terms of unequal distribution of renewable energy productivity across these countries. Besides, since the OECD countries are gradually transforming their economies from being agriculture-oriented to service-oriented and are becoming more focused on energy innovation and energy efficiency aspects, it can be hypothesized that this structural transformation might reduce the inequality in renewable energy productivity among these nations. Using second-generation methods and dynamic elasticity analysis, this study finds that structural transformation helps to reduce the inequality in renewable energy productivity. Besides, technological innovation is also evidenced to exert inequality-reduction effects. In contrast, conflicts and economic conflicts are evidenced to generated adverse effects on inequality in renewable energy productivity within the OECD countries. Furthermore, the outcomes from this study have also identified the policy interventions responsible for the aggravation of inequality in renewable energy productivity. Based on these findings, a policy framework has been provided to help the OECD countries to attain the objectives of SDG 7 and SDG13.

Smart control of air conditioning systems in manufacturing systems facing uncertainty

Enhancing energy use efficiency and reducing energy demand are important issues for industry and academe. Studies on the ventilation, and air conditioning (HVAC) system highlighted the optimization of individual devices, but did not fully consider global optimization. The heating and cooling mechanism of an HVAC system in the present study comprises multiple chillers, chilled water pumps, condenser water pumps, and cooling towers. This study proposes a smart control model of heating, ventilation, and HVAC systems in manufacturing systems to deal with dynamic indoor cooling demands and outdoor temperature changes. A stochastic mixed integer mathematical programming model optimizes the heating and cooling decisions of the HVAC system for energy conservation. This study also investigates a case of the HVAC system in a TFT-LCD manufacturing firm. Experiment results indicate that the proposed model saves up to 3.2% of total energy in the target HVAC system.

The food-energy-water-carbon nexus in a maize-maize-mustard cropping sequence of the Indian Himalayas: An impact of tillage-cum-live mulching

Amid the current environmental crises that exert enormous pressure on the arable lands, there is a need to adopt environment-friendly effective but highly productive conservation agriculture practices to feed the growing world population. Thus, a study was conducted to test the hypothesis that the inclusion of cowpea (Vigna unguiculata L. Walp) live mulch under no-till and reduced tillage in the summer maize (Zea mays L.) – rainy season maize-mustard (Brassica juncea (L.) czern) sequence would enhance agronomic productivity, energy use efficiency, and water productivity while reducing greenhouse gases emissions. Five tillage treatments viz., no-till, no-till-live mulch, reduce tillage, reduce tillage-live mulch, and conventional tillage were evaluated in three times replicated randomized complete block design. Land productivity for maize–maize–mustard system was the highest under reduced tillage-live mulch. No-till-live mulch had 36.4% lesser energy requirement, 2.4 times more energy productivity than that under conventional tillage. Reduced tillage-live mulch and no-till-live mulch had higher water productivity compared to all other treatments. The conventional tillage had the highest net CO2-eq emission while no-till-live mulch had the lowest. Inclusion of cowpea as live mulch enhanced C sequestration which has the potential to offset approximately half of the total CO2 emission, enhance energy use efficiency, land and water productivity. The findings of this study might be useful to develop a policy for sustainable high productivity through efficient resource use in the Eastern Himalayan Ecosystems that have the potential to become the corn belts of India.

Emission Mitigation and Energy Security Trade-Off: Role of Natural Gas in the Indian Power Sector

India’s Nationally Determined Contributions (NDC) aim to increase the share of non-fossil fuel, especially renewables, in power generation. But at the same time, it mentions that coal is likely to dominate the power generation in the short and medium term to meet the increase in demand and support the intermittency of renewable energy-based power generation. Thus, additional efforts to transform the thermal power generation to a more efficient and less emitting one in the near term by increasing the use of natural gas (a fossil fuel with a lower emission factor than coal) may be planned towards achieving India’s additional mitigation commitments. The paper presents the implications of a proposed increase in the share of natural gas in thermal power generation of India by looking into the trade-off between emission mitigation and energy security. Along with a Reference Scenario, three alternative emission scenarios are proposed to understand the likely impacts of increased penetration of natural gas in power generation on India’s projected emission profile up to 2050. Results suggest that higher mitigation potential can be achieved through fuel-switch in thermal generation and technological up-gradation to enhance energy use efficiency. The energy security due to the increased share of natural gas imports can be dealt with by diversifying import sources. Shifts can achieve this in the emphasis on long-term contracts.

No-till and mulching enhance energy use efficiency and reduce carbon footprint of a direct-seeded upland rice production system

Sustainability of conventional agricultural production systems is threatened by triple challenges of energy and environmental crises, deteriorating natural resources bases, and declining farm profitability. Current agricultural management practices (energy-intensive, inefficient external and natural input use, and crop biomass burning) are negatively impacting the ecosystem services which are the principal drivers for food security and human survival. Hence, there is a need to shift from unsustainable production practices to cleaner production systems. Energy use, carbon footprint (CF), and economic sustainability are important indicators of any clean production systems. Thus, a hypothesis was formulated that no-till (NT) cultivation along with mulching can provide an environmentally clean crop production practice that can enhance energy use efficiency, economic profitability, and reduce the CF. Therefore, the present experiment was conducted for four consecutive years (2012–15) to evaluate the energy budget, CF, and economics of NT along with bio-mulching for a cleaner upland rice production system. The experiment comprised of two tillage practices i.e., conventional tillage (CT) and NT in main plots and four bio- mulches in subplots i.e., rice straw mulch (RSM), Gliricidia sepium mulch (GLM), brown manuring mulch (BMM) of cowpea (Vigna unguiculata), and no mulch (NM) as a control. Results revealed that the adoption of NT curtailed energy use by 48.50%, specific energy by 49.63%, CF by 16.48%, and cost of cultivation by 35% in addition to enhancing energy use efficiency and benefit to cost ratio in comparison to CT. It was also observed that mulching, particularly the BMM, boosted the energy use efficiency, economic productivity, net returns, and benefit to cost ratio over NM. The results suggested that NT with BMM is an environmentally clean production technology to enhance the energy use efficiency, besides reducing the CF of direct-seeded upland rice production system in the Eastern Himalayas and similar eco-regions of the world.

Effects of crop rotation on energy use efficiency of irrigated potato with cereals, canola, and alfalfa over a 14-year period in Manitoba, Canada

Crop rotations can be used to optimize energy use efficiency (EUE) by preserving or enhancing optimal fertility and chemical use and reducing greenhouse gas (GHG) emissions. A field experiment consisting of six rotations of potato (Solanum tuberosum L.) with canola (Brassica napus L.) (P-C), wheat (Triticum aestivum L.) (P-W), canola-wheat (P-C-W), oat (Avena sativa L.)-wheat (P-O-W), wheat-canola-wheat (P-W -C-W), and canola underseeded to alfalfa (Medicago sativa L.)-alfalfa-alfalfa (P-C(A)-A-A) was conducted on a clay loam soil in Manitoba, Canada for 14 years to assess the relative energy use performance of potato and all crops in each rotation. The potato phase in the P-C(A)-A-A rotation had the largest average annual net energy (93.5 GJ ha−1), the largest output/input energy ratio (3.65), the highest potato yields harvested per GJ input (1013 kg GJ−1) and the lowest cost per tonne of carbon retained ($912 t−1) in comparison with potato in the other rotations. The net energy, energy ratio, and potato yield harvested per GJ input used for potato in P-C(A)-A-A was, respectively, 11%, 10%, and 9.5% higher than 2-yr P-W or P-C rotations. Similarly, cost per tonne of carbon retained for potato in the 2-yr rotations was 8% higher than for potato in the P-C(A)-A-A rotation. The 2-yr rotations performed well in terms of EUE and economics in early cycles of the study but became less efficient as the study progressed due to buildup of plant diseases and decreased yields. The EUE indicators of entire rotations were different; however, the overall results suggested that the longer P-C-W or P-C(A)-A-A rotations are beneficial in that P-C-W provided better economic and EUE outcomes overall while P-C(A)-A-A provided the best potato yield and environmental indicators. These findings suggest that potato growers should include a legume in their crop rotation systems to enhance energy use efficiency while maintaining crop productivity.

Enhancing ecosystem services and energy use efficiency under organic and conventional nutrient management system to a sustainable arecanut based cropping system

The present study was undertaken to explore the impact of no nutrient, organic nutrition, and integrated nutrient management on ecosystem services, and the energy balance of the arecanut based intercropping system. Most indicators of ecosystem services were influenced significantly by nutrient management practices. The energy efficiency (1.72) and net energy (19625 MJ ha−1) improved significantly in the organic nutrient practice due to lower energy input (30722 MJ ha−1) and higher energy output (50347 MJ ha−1). The mean values of the indicator of dependence on non-renewable energy sources and an indicator of farm autonomy for organic farms were 0.3 and 0.46, respectively. The study suggests 46% of the inputs produced in the farm were recycled in the organic farms. The significantly higher sustainability yield index (0.25), sustainability value index (0.44) and system economic efficiency (21 USD day−1) were observed in the organic nutrient system. The study concludes that organic nutrition along with adequate management is required to harness the potential of arecanut based cropping system to improve energy efficiency, ecosystem services, and soil quality to achieve sustainability.

Can conservation tillage and residue management enhance energy use efficiency and sustainability of rice-pea system in the Eastern Himalayas?

ABSTRACTLow productivity and energy use efficiency (EUE) of rice farming are the major concerns for agricultural sustainability in the Eastern Himalayan region of India. A field experiment on rice (Oryza sativa L.)-pea (Pisum sativum L) system was conducted for three consecutive years during 2012–15 in lowland ecosystem to assess the direct and residual impact of tillage and residue management (RM) practises on productivity and sustainability. Significantly higher grain yield of rice was achieved under no-till (NT) than minimum tillage (MT) and conventional tillage (CT). Among RM practises, 50% NPK + green leaf manure, 50% NPK + weed biomass and 50% NPK + in-situ residue retention recorded significantly higher mean grain yields than application of 50% NPK and 100% NPK without residues. Residual effect of MT in preceding rice gave significantly higher green pod yield of succeeding pea than NT and CT. The system EUE was significantly higher under MT (rice)-NT (pea) compared to those of NT-NT and CT-NT systems. The sustainable yield index of rice and pea was maximum under MT-NT followed by NT-NT. Thus, NT/MT with suitable RM practises is a pertinent strategy for sustainable productivity of rice-pea system in the Eastern Himalayas and in similar adjoining regions.

Emergy Analysis of Greenhouse Cucumber Production in Sistan Region

In the current century, agriculture sustainability and the reduction of environmental pressure are two main objectives of the management of agro-ecosystems that is challenged by energy inefficiency. In this respect, the present study assessed one of the most important planting systems in Sistan region by emergy analysis approach. It analyzed all inputs of greenhouse cucumber production system in Sistan including renewable inputs (sunlight, wind, rain), non-renewable inputs (net topsoil loss), and purchased inputs (machinery, fossil fuels, electricity, plastic, utility, labor, N, K, P and micro fertilizers, and chemical herbicides) and services. In this study, an emergy analysis was performed on greenhouse cucumber production system of Sistan using the data collected from a 3000-m2 greenhouse in Zahak Agricultural Research Station (as an average representative of agricultural lands in Sistan Region). The results revealed that total emergy of greenhouse cucumber system was 1.094 × 1018 seJ, and diesel fuel and labor were the main emergy consumers with the emergy consumption rates of 7.9 × 1017 and 1.92 × 1017 seJ ha-1, respectively. Main emergy indices including emergy yield ratio, emergy investment ratio, environmental loading ratio, and sustainability index were found to be 1.00, 2089, 4.34 and 20.23, respectively. Therefore, it is imperative to consider the optimization of highly consumed inputs, the reduction of environmental impacts, and the increase in sustainability by making changes in greenhouse structures, enhancing energy use efficiency inside the greenhouse, and mechanizing the planting, cultivating and harvesting processes in order to develop greenhouse cucumber system in Sistan.

Households’ Energy Consumption Change in China: A Multi-Regional Perspective

As China’s economy enters the “new normal” phase, its growth model has gradually changed to focus more on domestic consumption. In this paper, we examine regional disparities in households’ total (direct and indirect) energy use in China from 2002 to 2012. Using a structural decomposition approach, we examine how changes in China’s technology, economic structure, urbanization, lifestyle, and interregional trade affect household energy use across different regions. We find that rising income levels contributed most to energy usage. Improved energy efficiency offset the rising effects of heightened household consumption in most regions. Rural-to-urban migration played an important role in enhancing energy use in all regions from 2002 to 2012. Moreover, households started to rely more heavily on interregional trade of final goods and services to meet their consumption demands. Based on this multi-regional and multi-angle study, we provide some regional-specific policies that would help curb household energy demand and promote sustainable consumption in China.

Energy Use and Policy Implications for Energy Security in Asia: A Panel Data Approach

The article aims to investigate impacts of determinants on energy use in 13 Asian countries for the past two decades (1996-2015) by employing a panel database. We found that electric power per capita, fossil fuel consumption, fuel exports, and gross domestic product (GDP) per unit of energy use have positives influences on energy use in Asia. However, fuel imports and investment in energy with participation of the private negatively affects energy use in this region. Our results also addressed that energy use in Asian countries still heavily depends upon fossil energy such as coal, oil, and natural gas. Indeed, our findings stated that economic growth is a positive motivation in terms of enhancing energy use in Asia. Lastly, policies are recommended to ensure energy security and foster economic growth in Asia. DOWNLOAD HISTORY | This article has been downloaded 512 times in Digital Commons before migrating into this platform.

Input-output energy analysis of rice production in different crop management practices in central China

Abstract Reducing energy inputs and enhancing energy use efficiency (EUE) are essential to ensure energy security and long-term sustainability of rice production. Central China accounts for 54% of the total rice cultivated area and total rice production in China. To date, assessments of energy use and EUE regarding rice production in central China have not been performed. To perform these assessments, we determined energy input and EUE in farmers’ practice (FP) and simplified and reduced-input practice (SRIP) using an input-output energy analysis. The results suggested that energy input, energy output, and rice grain yield in FP and SRIP were 34544.4 and 25441.5 MJ ha−1, 266744.9 and 234393.0 MJ ha−1, and 9171.3 and 8449.9 kg ha−1, respectively. SRIP exhibited 19.0% and 24.8% significantly higher EUE and energy productivity than FP, respectively. Lower specific energy in SRIP (3.01 MJ kg−1) than in FP (3.76 MJ kg−1) indicated that the energy used to produce one unit of grain was lower in SRIP than in FP. This study demonstrated that EUE could be significantly increased by reducing energy consumption with the adoption of SRIP. Future rice production with reduced energy input will require more innovative agronomic practices to improve both yield and energy output.

Smart grid data analytics framework for increasing energy savings in residential buildings

Abstract Human energy consumption has gradually increased greenhouse gas concentrations and is considered the main cause of global warming. Currently, the building sector is a major energy consumer, and its share of energy consumption is increasing because of urbanization. This paper presents a framework for smart grid big data analytics and components required for an energy-saving decision-support system. The proposed system has a layered architecture that includes a smart grid, a data collection layer, an analytics bench, and a web-based portal. A smart metering infrastructure was installed in a residential building to conduct an experiment for evaluating the effectiveness of the proposed framework. Furthermore, a novel hybrid nature-inspired metaheuristic forecast system and a dynamic optimization algorithm are designed behind the analytics bench for achieving accurate prediction and optimization of future energy consumption. The main contribution of this study is that an innovative framework for the energy-saving decision process is presented; the framework can serve as a basis for the future development of a full-scale smart decision support system (SDSS). Through the identification of consumer usage patterns, the SDSS is expected to enhance energy use efficiency and improve the accuracy of future energy demand estimates. End users can reduce their electricity costs by implementing the optimal operating schedules for appliances, which are provided by the SDSS.

Effects of Tillage and Crop Establishment Methods, Crop Residues, and Nitrogen Levels on Wheat Productivity, Energy-savings and Greenhouse Gas Emission under Rice -Wheat Cropping System

Field experiments were conducted to evaluate conventional tillage (CT), permanent raised bed (PRB), and zero tillage (ZT) with residue retention and removal at three nitrogen levels (0, 100, and 120 kg N ha-1) on wheat productivity, energy input and energy output, energy use efficiency, specific energy, and CO2 emission from 2010 to 2012 under rice-wheat system at Pheta V.D.C, Bara, Nepal. The experiments were carried out in strip split plot designs with three replications. Zero tillage wheat produced significantly higher grain yield (2616.5 kg ha-1), saved 10.4 % energy input, increased energy output (12.4 %), enhancing energy use efficiency by 25.2 % and reducing specific energy by 23.6 %, as compared to conventional tillage. Diesel consumption on crop establishment and irrigations were the lowest for ZT (48.6 liter ha-1) and the highest for CT (86.3 liter ha-1). PRB consumed the lowest quantity of diesel on two irrigations (34.6 liter ha-1) with higher energy use efficiency (3.4 %) and lower specific energy (8.76 MJ kg-1) over CT. The CO2 emission from CT was the highest (224.32 kg ha-1) over ZT (126.4 kg ha-1) and PRB (146.11 kg ha-1). Residue retention increased 4 % grain yield over residue removal. Without nitrogen application, energy output was the lowest (34192 MJ ha-1) with the highest specific energy (12.6 MJ kg-1). Thus, zero-till wheat with 40-cm residue retention and 100 kg N ha-1 application was suggested for mass scale adoption in the Tarai region of Nepal.DOI: http://dx.doi.org/njst.v15i2.12104 Nepal Journal of Science and Technology Vol. 15, No.2 (2014) 1-10