13 results on '"Walasai, Gordhan Das"'
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2. Long-term electricity demand forecast and supply side scenarios for Pakistan (2015–2050): A LEAP model application for policy analysis
- Author
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Mirjat, Nayyar Hussain, Uqaili, Muhammad Aslam, Harijan, Khanji, Walasai, Gordhan Das, Mondal, Md Alam Hossain, and Sahin, Hasret
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- 2018
- Full Text
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3. Assessment of Climate Driven Changes in Flow Series of Alpine Basin: A Case Study of Danube River Basin
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Laghari, Abdul Nasir, Rajper, A., Walasai, Gordhan Das, Jatoi, Abdul Rehman, Jalbani, Nabi Bux, and Soomro, Hira
- Subjects
man-made abstraction ,climate change ,Alpine river ,seasonal flow regime - Abstract
This study was carried out in order to analyze the climate change driven influence on mean monthly flow series of Danube River and its tributaries during the last century. The study confirms some signs of climate driven alterations in monthly river flow series along with change in flow seasonality during the last century. In spite of this, man-made interference in the basin like i.e. groundwater extraction, irrigation, river regulation, land use alteration and urbanization, has significantly changed Danube flow regime in most areas of the catchment. The analysis of Achleiten station demonstrates that average annual flow regime is a little bit increased. Major increase is observed in winter and autumn months and decrease in summer months. These seasonal alterations clearly signal a future glimpse of reduced water availability in alpine basins. This will mainly occur due to the change in the form of precipitation in winter, from snow to rain and the consequent less snow accumulation, and the early melt of snow storage, less precipitation and high evaporation rate in summer.
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- 2018
- Full Text
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4. Performance Evaluation of Locally-Produced Waste Cooking Oil Biodiesel with Conventional Diesel Fuel
- Author
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Khaskheli, Abid Ali, Walasai, Gordhan Das, Jamali, Abdul Sattar, Jamali, Qadir Bakhsh, Siyal, Zafar Ali, and Mengal, Abdullah
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engine ,BSFC ,biodiesel ,WCO ,BTE - Abstract
Increasing environmental concerns forced us to look for cheaper, reliable and secure sources of energy. Fossil fuels like oil, coal, and natural gas are having limited supplies and are depleting fast. Both energy security and environmental concerns have resulted in inclination towards renewable energy sources. Biodiesel does not contain petroleum, but it can be blended with petro-diesel in various mix levels. This research investigated biodiesel produced by the use of cheap waste cooking oil, collected from the local market of Nawabshah, Pakistan. The collected waste oil was converted into biodiesel by transesterification process at PCSIR Laboratory, Karachi. The fuel samples were tested in a diesel engine test bed unit at the Thermodynamics Laboratory of Quaid-e-Awam University. Biodiesel blends were compared with the conventional diesel fuel. The comparative analysis of the performance parameters concluded that brake specific fuel consumption of B30 (biodiesel 30%+diesel 70%) mix was 6.9% higher than that of 100% diesel. The brake thermal efficiency of B30 decreased about 4.75% in comparison with conventional diesel.
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- 2018
- Full Text
- View/download PDF
5. Performance Analysis Of Water Filtration Units For Reduction Of Ph, Turbidity, Solids And Electricity Conductivity
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Laghari, Abdul Nasir, Walasai, Gordhan Das, Jatoi, Abdul Rehman, Shaikh, Faheem Akhtar, and Siyal, Zafar Ali
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pH ,water filtration ,water quality ,turbidity - Abstract
The main objective of this study was to analyze the performance of different filtration units that reduce turbidity, pH, total dissolved solids (TDS) and electrical conductivity (EC) of canal water. For that, three different types of filtration units, namely, slow sand, rapid sand and dual media were fabricated. Typical parameters of canal and filtered water, like pH, turbidity, TDS and EC were examined, and then the filtered water quality was compared with World Health Organizations (WHO) standards. Maximum pH reduction was noted with dual media and less by the rapid system, while more turbidity was reduced with the slow sand and less with the dual media filtration system. In contrary to the pH and turbidity results, increment in both TDS and EC values were noted in filtered samples compared to that of raw water samples due to the transfer of dissolved minerals present in the sand into the filtered water during the contact period with media in the bed. However, all examined parameters of filtered water were within WHO standards.
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- 2018
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6. Overcoming Electricity Crisis in Pakistan: An Overview of the Renewable Energy Status and Development in Pakistan
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Rehman, Syed Aziz Ur, primary, Cai, Yanpeng, additional, Nafees, Mohammad, additional, Walasai, Gordhan Das, additional, Mirjat, Nayyar Hussain, additional, and Rashid, Wajid, additional
- Published
- 2017
- Full Text
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7. Effects of Climate Change on Mountain Waters: A Case Study of European Alps.
- Author
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Laghari, Abdul Nasir, Bangwar, Daddan Khan, Walasai, Gordhan Das, Jatoi, Abdul Rehman, and Shaikh, Abdul Hannan
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CLIMATE change ,ATMOSPHERIC models ,MOUNTAINS ,WATER temperature ,GREENHOUSE gas mitigation - Abstract
The Alps play a vital role in the water supply of the region through the rivers Danube, Rhine, Po and Rhone while they are crucial to the ecosystem. Over the past two centuries, we witnessed the temperature to increase by +2 degrees, which is approximately three times higher than the global average. Under this study, the Alps are analyzed using regional climatic models for possible projections in order to understand the climatic changes impact on the water cycle, particularly on runoff. The scenario is based on assumptions of future greenhouse gases emissions. The regional model results show the consistent warming trend in the last 30-year span: temperature in winter may increase by 3 to 4.5°C and summers by 4 to 5.5°C. The precipitation regime may also be altered: increasing about 10-50% in winter and decreasing about 30-60% in summer. The changes in the amount of precipitation are not uninformed. Differences are observed particularly between the North West and South East part of the Alps. Due to the projected changes in alpine rainfall and temperature patterns, the seasonality of alpine flow regime will also be altered: massive rise will occur in winter and a significant reduction in summer. The typical low flow period during winter will also be shifted to late summer and autumn. [ABSTRACT FROM AUTHOR]
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- 2018
- Full Text
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8. Analysis of Mapping Techniques for Mountain Precipitation: A Case Study of Alpine Region, Austria.
- Author
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Laghari, Abdul Nasir, Memon, Aftab Hameed, Walasai, Gordhan Das, Bangwar, Daddan Khan, and Shaikh, Abdul Hannan
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MOUNTAINS ,METEOROLOGICAL precipitation ,REGRESSION analysis ,KRIGING ,TOPOGRAPHY - Abstract
Truly representative precipitation map generation of mountain regions is a difficult task. Due to poor gauge representativity, complex topography and uneven density factors make the generation of representative precipitation maps a very difficult task. To generate representative precipitation maps, this study focused on analyzing four different mapping techniques: ordinary kriging, spline technique (SP), inverse distance weighting (IDW) and regression kriging (RK). The generated maps are assessed through cross-validation statistics, spatial cross-consistency test and by water balance approach. The largest prediction error is produced by techniques missing information on co-variables. The ME and RMSE values show that IDW and SP are the most biased techniques. The RK technique produced the best model results with 1.38mm and 72.36mm ME and RMSE values respectively. The comparative analysis proves that RK model can produce reasonably accurate values at poorly gauged areas, where geographical information compensated the poor availability of local data. [ABSTRACT FROM AUTHOR]
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- 2018
- Full Text
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9. FKTR Performance Analysis of Water Filtration Units for Reduction of pH, Turbidity, Solids and Electricity Conductivity.
- Author
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Laghari, Abdul Nasir, Shaikh, Faheem Akhtar, Walasai, Gordhan Das, Jatoi, Abdul Rehman, and Siyal, Zafar Ali
- Subjects
WATER filtration ,ELECTRIC conductivity ,TURBIDITY ,HYDROGEN ion concentration in water - Abstract
The main objective of this study was to analyze the performance of different filtration units that reduce turbidity, pH, total dissolved solids (TDS) and electrical conductivity (EC) of canal water. For that, three different types of filtration units, namely, slow sand, rapid sand and dual media were fabricated. Typical parameters of canal and filtered water, like pH, turbidity, TDS and EC were examined, and then the filtered water quality was compared with World Health Organizations (WHO) standards. Maximum pH reduction was noted with dual media and less by the rapid system, while more turbidity was reduced with the slow sand and less with the dual media filtration system. In contrary to the pH and turbidity results, increment in both TDS and EC values were noted in filtered samples compared to that of raw water samples due to the transfer of dissolved minerals present in the sand into the filtered water during the contact period with media in the bed. However, all examined parameters of filtered water were within WHO standards. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
10. An Integrated Modeling Approach for Forecasting Long-Term Energy Demand in Pakistan.
- Author
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Ur Rehman, Syed Aziz, Yanpeng Cai, Fazal, Rizwan, Walasai, Gordhan Das, and Mirjat, Nayyar Hussain
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ENERGY development ,POWER resources ,ENERGY conservation ,ENERGY policy ,BOX-Jenkins forecasting ,ENERGY security - Abstract
Energy planning and policy development require an in-depth assessment of energy resources and long-term demand forecast estimates. Pakistan, unfortunately, lacks reliable data on its energy resources as well do not have dependable long-term energy demand forecasts. As a result, the policy makers could not come up with an effective energy policy in the history of the country. Energy demand forecast has attained greatest ever attention in the perspective of growing population and diminishing fossil fuel resources. In this study, Pakistan's energy demand forecast for electricity, natural gas, oil, coal and LPG across all the sectors of the economy have been undertaken. Three different energy demand forecasting methodologies, i.e., Autoregressive Integrated Moving Average (ARIMA), Holt-Winter and Long-range Energy Alternate Planning (LEAP) model were used. The demand forecast estimates of each of these methods were compared using annual energy demand data. The results of this study suggest that ARIMA is more appropriate for energy demand forecasting for Pakistan compared to Holt-Winter model and LEAP model. It is estimated that industrial sector's demand shall be highest in the year 2035 followed by transport and domestic sectors. The results further suggest that energy fuel mix will change considerably, such that oil will be the most highly consumed energy form (38.16%) followed by natural gas (36.57%), electricity (16.22%), coal (7.52%) and LPG (1.52%) in 2035. In view of higher demand forecast of fossil fuels consumption, this study recommends that government should take the initiative for harnessing renewable energy resources for meeting future energy demand to not only avert huge import bill but also achieving energy security and sustainability in the long run. [ABSTRACT FROM AUTHOR]
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- 2017
- Full Text
- View/download PDF
11. Electricity Demand Forecasting: A Pakistans Perspective.
- Author
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Shaikh, Suhail Ahmed, Mirjat, Nayyar Hussain, Korejo, Wajahat Shabbir, Walasai, Gordhan Das, Larik, Abdul Sattar, and Hussain, Arsalan
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ELECTRIC power consumption ,ELECTRIC utilities ,ENERGY consumption ,POWER resources ,ENERGY industries - Abstract
Accurate and realistic electricity demand projection has attained greatest ever importance in overall energy planning. Various methods are found in the literature for electricity demand forecasting ranging from econometric models to statistical tools and the energy models. The demand of electricity in the country has increased along with the number of electricity consumers in Pakistan over last 2-3 decades. However, the countrys energy and power departments capacity to rationally forecast electricity demand and subsequent planning as well as the implementation of developed strategies has not delivered to meet the demand. This paper examines the long-term electricity demand forecasting approaches and specifically reviews the demand projection studies as well as methodologies used in the past. There are mainly five consumer groups identified in the electricity sector of Pakistan i.e. domestic, commercial, industrial, agriculture and other. The growth parameters of each of these groups are pivotal to more accurate electricity demand projection. The Water and Power Development Authority (WAPDA) for nearly 40 years following the independence was responsible for power sector planning. However, following the restructuring of WAPDA, National Transmission and Dispatch Company (NTDC) in coordination with Distribution Companies (DISCOs) undertake electricity demand projection studies. This review finally identifies various loopholes in electricity planning and suggests various parameters and steps which require due consideration for electricity demand forecasting in Pakistan. [ABSTRACT FROM AUTHOR]
- Published
- 2017
12. Economic Viability and Environmental Efficiency Analysis of Hydrogen Production Processes for the Decarbonization of Energy Systems.
- Author
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Xu, Li, Wang, Ying, Shah, Syed Ahsan Ali, Zameer, Hashim, Solangi, Yasir Ahmed, Walasai, Gordhan Das, and Siyal, Zafar Ali
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HYDROGEN production ,MANUFACTURING processes ,HYDROGEN analysis ,ANALYTIC hierarchy process ,HYDROGEN as fuel ,DATA envelopment analysis - Abstract
The widespread penetration of hydrogen in mainstream energy systems requires hydrogen production processes to be economically competent and environmentally efficient. Hydrogen, if produced efficiently, can play a pivotal role in decarbonizing the global energy systems. Therefore, this study develops a framework which evaluates hydrogen production processes and quantifies deficiencies for improvement. The framework integrates slack-based data envelopment analysis (DEA), with fuzzy analytical hierarchy process (FAHP) and fuzzy technique for order of preference by similarity to ideal solution (FTOPSIS). The proposed framework is applied to prioritize the most efficient and sustainable hydrogen production in Pakistan. Eleven hydrogen production alternatives were analyzed under five criteria, including capital cost, feedstock cost, O&M cost, hydrogen production, and CO
2 emission. FAHP obtained the initial weights of criteria while FTOPSIS determined the ultimate weights of criteria for each alternative. Finally, slack-based DEA computed the efficiency of alternatives. Among the 11, three alternatives (wind electrolysis, PV electrolysis, and biomass gasification) were found to be fully efficient and therefore can be considered as sustainable options for hydrogen production in Pakistan. The rest of the eight alternatives achieved poor efficiency scores and thus are not recommended. [ABSTRACT FROM AUTHOR]- Published
- 2019
- Full Text
- View/download PDF
13. Modeling of Future Electricity Generation and Emissions Assessment for Pakistan.
- Author
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Mengal, Abdullah, Mirjat, Nayyar Hussain, Walasai, Gordhan Das, Khatri, Shoaib Ahmed, Harijan, Khanji, and Uqaili, Mohammad Aslam
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ELECTRIC power production ,RENEWABLE energy sources ,FOSSIL fuel power plants ,FOSSIL fuels ,ELECTRIC power consumption ,ALTERNATIVE fuels - Abstract
Electricity demand in Pakistan has consistently increased in the past two decades. However, this demand is so far partially met due to insufficient supply, inefficient power plants, high transmission and distribution system losses, lack of effective planning efforts and due coordination. The existing electricity generation also largely depends on the imported fossil fuels, which is a huge burden on the national economy alongside causing colossal loss to the environment. It is also evident from existing government plans that electricity generation from low-cost coal fuels in the near future will further increase the emissions. As such, in this study, following the government's electricity demand forecast, four supply side scenarios for the study period (2013–2035) have been developed using Long-range Energy Alternatives Planning System (LEAP) software tool. These scenarios are Reference scenario (REF) based on the government's power expansion plans, and three alternative scenarios, which include, More Renewable (MRR), More Hydro (MRH), and More Hydro Nuclear (MRHN). Furthermore, the associated gaseous emissions (CO
2 , SO2 , NOX , CH4 , N2 O) are projected under each of these scenarios. The results of this study reveal that the alternative scenarios are more environmentally friendly than the REF scenario where penetration of planned coal-based power generation plants would be the major sources of emissions. It is, therefore, recommended that the government, apart from implementing the existing plans, should consider harnessing the renewable energy sources as indispensable energy sources in the future energy mix for electricity generation to reduce the fossil-fuel import bill and to contain the emissions. [ABSTRACT FROM AUTHOR]- Published
- 2019
- Full Text
- View/download PDF
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