In recent decades, there has been a dramatic increment in plastic consumption. Used plastic is one of the major wastes in many countries including Nepal. A lot of money is spent in land filling to process plastic wastes which can pose a threat to environment in long run. The incineration of plastic wastes leads to severe air pollution. Plastic pyrolysis process is a widely used technique to handle plastic wastes in many foreign countries. It is a new technology in Nepalese context. It involves melting plastic wastes, vaporizing them, condensing the vapor and distilling to obtain fuel. In the pyrolysis reactor, plastics are heated, vaporized and the vapor thus produced is passed to shell and tube condenser for condensation. The liquid thus obtained is called pyrolysis oil and char remains in pyrolysis reactor as residue. The yields depend on various factors like plastic type used, cracking temperature of plastic, rate of heating, operation pressure of reactor, type of reactor, residence time, use of catalyst, etc. The plant was designed and modeled in 3D CAD software, Solidworks. Batch reactor was employed to pyrolyze Low Density Polyethylene at reactor base temperature of about 600°C and the vapour produced was directed to horizontal, counter-flow shell and tube condenser. From 10 kg of plastics, the plant yielded 6.63 liters of pyrolysis oil and 2.236 kg of char, on average, in the cost of 3.169 kg of LPG gas.

Supply chain sustainability as a new and very effective approach has recently attracted the attention of researchers in the field of supply chain management. Also, a circular economy helps to reduce the waste materials and products in a supply chain. In order to include circular economy in supply chain network design, it is necessary to use the concept of closed-loop network design. Therefore, designing a sustainable closed-loop supply chain network that works well even by changing some parameters seems to be necessary. This paper presents a multiproduct, sustainable closed-loop supply chain network under uncertainty. First, a mathematical model is proposed to design a closed-loop network, and then a set of possible scenarios is used to deal with the uncertainty of the parameters. In order to show the validity and applicability of the proposed model, numerical examples are presented and analyzed. In this regard, numerical results show the appropriate performance of the proposed mode...

Aluminium 6061 (Al6061) alloy, which is known as commercial alloy, is massively used in aviation and automobile industries. Therefore, research on Al6061 alloy is gaining significance among scientists and researchers all over the world as it provides light weight, high strength and stiffness, high impact, and corrosion resistance in engineering applications. The comprehensive analysis of mechanical behavior under large stress-strain deformation responses of the alloy is studied over a wide range of strain-rates such as 1 × 10−3 s−1, 1 × 103 s−1, 2 × 103 s−1, and 3 × 103 s−1 under room temperature to elevated temperatures of 100°C and 200°C. In this regard, this study aims to evaluate the Johnson–Cook strength and fracture constants utilizing the Johnson–Cook constitutive model equations. Furthermore, the evaluated constant parameters have been used to perform numerical simulation analysis utilizing ABAQUS/CAE software. According to the study’s findings, the critical perforation velo...

Gravitational water vortex power generation plant is ultra-low head micro hydro concept which requires mere 0.7-2m of height. GWVPP is based on the principle of power generation with rotation of turbine with the help of vortex generated due to basin structure when water can pass tangentially. This technology is in a primitive phase of development in various part of world. So, developers across the world are interested on how it performs in real site as only few real installations have been made far. This paper attempts to analyze the performance of different scale down model of GWVPP. First, the performance is compared among various experimental studies and pilot installations done so far in Nepal. After that the analysis of different computational studies is performed. To accesses the validation of the result obtained from the past researches, 1:20 scale down model of a plant which is to be installed in Johannesburg South Africa is developed and whose computational and experimental result is compared and predicted the model performance.

In today's world, where global warming is one of the greatest human challenges, sustainable energy generation is becoming increasingly relevant. The use of green and clean energy sources is the best way to minimize CO 2 , CO, NO X and other emissions of conventional energy usage. Solar photovoltaic (PV) systems are more beneficial and an exciting application to set up an eco-friendly green educational campus. In this regard, the potential sites within Tribhuvan University, Institute of Engineering, Purwanchal Campus, Dharan city, Nepal are analysed for grid-tied solar PV power plant installation to meet the 100% energy demand of the campus using energy, economic and environment-friendly analysis. The daily, monthly and annual load and solar irradiance data of past years of the campus have been analysed to estimate the solar PV plant's capacity and system performance using PVSYST V7.0 software analysis tools .The simulation results show that 110 kWp of solar PV power plant will be sufficient for the entire campus to qualify for the first fully green-powered campus in Nepal, which corresponds to fulfill 66.4 MWh/year daytime energy demand out of total 161 MWh/year energy consumption of the campus with a capacity to generate a total of 181.5 MWh/year energy from the designed solar PV system. The result also shows that 115.1 MWh/year of surplus energy produced from the PV power plant can be injected into the utility grid to yield considerable savings in utility cost. On the basis of these results, campus authorities and stakeholders may commit to investing and implementing of this project to ensure that the campus is completely green.

Aluminium 6061 (Al6061) alloy, which is known as commercial alloy, is massively used in aviation and automobile industries. erefore, research on Al6061 alloy is gaining significance among scientists and researchers all over the world as it provides light weight, high strength and stiffness, high impact, and corrosion resistance in engineering applications. e comprehensive analysis of mechanical behavior under large stress-strain deformation responses of the alloy is studied over a wide range of strain-rates such as 1 × 10 − 3 s − 1 , 1 × 10 3 s − 1 , 2 × 10 3 s − 1 , and 3 × 10 3 s − 1 under room temperature to elevated temperatures of 100°C and 200°C. In this regard, this study aims to evaluate the Johnson-Cook strength and fracture constants utilizing the Johnson-Cook constitutive model equations. Furthermore, the evaluated constant parameters have been used to perform numerical simulation analysis utilizing ABAQUS/CAE software. According to the study's findings, the critical perforation velocity was found to be 70 ms − 1 when a flat-nosed bullet (45 mm length and 12 mm diameter) made of stainless steel weighing 50 grams was fired normally to the center of a square plate specimen of Al6061 alloy. e specimen of the square flat plate was prepared with side 205 mm and 2 mm thickness (205 × 205 × 2 mm 3). A good correlation for critical perforation velocity of experimental acquisition data and numerical simulation results has been found. ese findings increase the knowledge of the material's response application to the high-velocity impact that can be used in arms-ammunition, aviation, marine, automobile, and home appliances.

Supply chain sustainability as a new and very effective approach has recently attracted the attention of researchers in the field of supply chain management. Also, a circular economy helps to reduce the waste materials and products in a supply chain. In order to include circular economy in supply chain network design, it is necessary to use the concept of closed-loop network design. erefore, designing a sustainable closed-loop supply chain network that works well even by changing some parameters seems to be necessary. is paper presents a multiproduct, sustainable closed-loop supply chain network under uncertainty. First, a mathematical model is proposed to design a closed-loop network, and then a set of possible scenarios is used to deal with the uncertainty of the parameters. In order to show the validity and applicability of the proposed model, numerical examples are presented and analyzed. In this regard, numerical results show the appropriate performance of the proposed model. Finally, sensitivity analysis is performed to assess the role of customer demand in different aspects of sustainability. It is revealed that increasing customer demand will have a strong impact on economic and environmental objectives.