This research paper presents an analysis of prospects and challenges of computer assisted virtual education systems in developing countries during COVID-19 pandemic. A questionnaire-based survey has been conducted through an online platform to assess the prospects and challenges of adopting computer assisted virtual education systems during the current pandemic in the 21st century. The questionnaire is composed of ten questions related to the computer assisted virtual education systems in Bangladesh. This analysis has been performed based on the data obtained from students’ perspectives. The outcome of the proposed research work is based on the response of 194 students of a Private University in Dhaka, Bangladesh. Almost equal number of students from urban and rural areas of Bangladesh have taken part in this survey willingly. From the analysis of the outcomes obtained from the survey it is revealed that there are a lot of prospects of online education along with some challenges in a developing country like Bangladesh. The outcome of the research based on prospects and challenges of online education systems can be a center of attraction for the researchers all over the world to develop a cost effective, user friendly, reliable computer assisted virtual education system for the developing countries, which may be also helpful for the underdeveloped countries in the very near future.

In this study, we subjected Centaurea virgata and Centaurea solstitialis extracts to a qualitative chemical analysis to identify the most important chemical groups they contain, we also aimed to determine their total phenolic content. In addition to the phytochemical study, hemolysis test was conducted to investigate the toxic effects of the plant extracts on red blood cells membranes, and to evaluate the plants’ ability to prevent the oxidative hemolysis for normal and G₆PD enzyme-deficient human erythrocytes. Qualitative Phytochemical analysis exposed that the aerial parts extracts contains phenolic compounds, tannins, flavonoids, saponins, and carbohydrates. Both extracts had good phenolic contents. The present study also showed that hydromethanolic extracts of the plants have no obvious toxic effects towards human erythrocytes membranes. The extracts proved their antioxidant activities through their excellent activities in protecting normal and G₆PD enzyme-deficient human erythrocytes from oxidative damage induced by H₂O₂. Further studies are wanted for detecting biological and biochemical effects of these plants.

Gasification has become the most important biomass conversion processes in recent years. There is an imperative need of an accurate mathematical model that can save cost and time from performing expensive experiments. In this study, a one-dimensional model is developed and solved in MATLAB to simulate a downdraft gasifier. The model incorporates the crucial effect of the pyrolysis fraction and char reactivity factor. The mass and energy balance are solved taking into account the kinetics of the reactions involved. The product composition, velocity, and pressure distribution along with temperature profile in the reduction zone are then obtained. The results obtained from the model are in close agreement with the experimental results.

India is facing multiple problems regarding taxation as tax evasion, black marketing, high price charge and corruption. Meanwhile indirect taxes paid by the producing firms are collected on level may be or may not be timely and honestly deposited to the department. There is a big issue of multiple tax system and the complex procedure. To get rid of these problems, a uniform tax system named as Goods and Service Tax (GST) was introduced. The current article is proposed to measure the effectiveness of GST as well as tries to analysis the effect of GST on Indian economic system especially in inflation rate and on foreign trade. Some suggestions are also proposed for make more effective system in India.

The risks associated with driving have resulted in severe tragedies and amongst these drowsiness is one such major risk. The state of drowsiness in drivers has led to accidents resulting in significant monetary losses, serious injuries and even deaths. Drivers involved in driving for longer times and distances are more prone to the state of drowsiness. The issues related to drowsiness have encouraged many researchers to develop detection mechanisms so that accidents could be averted. Researchers have discovered that most common basis for the detection of drowsiness are physiological based measures, behavioral based measures, subjective base measures and vehicle based measures. However, many researchers still endeavor to find more efficient solution for the detection of driver drowsiness. In this paper, major causes for drowsiness have been discussed. Various systems based upon which drowsiness can be detected have also been elaborated. Moreover, the conclusion of this paper focuses upon the gaps which if worked upon will bring new ways and means for developing a better and reliable system for detecting drowsiness. This paper will significantly contribute to the automobile industry as it will bring forth existing methods to detect drowsiness, and will also serve as a strong basis for the development of a robust drowsiness detection system which can be used as a safety feature for every automobile.

The application of the Elasto plastic-damage model is used to describe the ductile fracture model. Few parameters are responsible for ductile damage and its mechanism can be revealed by using Elasto plastic models. An overview of different models is described in this paper. Parameters responsible for high-stress triaxiality and low-stress triaxiality are also described in this paper. The objective of this article is to provide a review of Elasto-plastic damage models, which can be used for prediction of ductile fracture. Stress triaxiality is the ratio between mean stress and equivalent vonmisses stress.

Behavior Based Safety (BBS) approach is the “usage of science for changing the behavior of an individual”. “Behavior Based Safety” focuses on action of workmen on day-to-day safety behavior and its improvement. This study presents a case study within the multistory building construction in India. This research work plans the outline of the BBS method into 7 steps and encapsulates a number of behavioral safety methods to prevent the workplace accident. The objective of this paper is to create a safe work environment in construction industries by decreasing frequency severity of injuries and increase the safe behavior. The outcome of this research work revealed that a method related to observation, a real-time measure of safety behavior with appreciative and constructive feedback for the significant improvement of the safety performance in multistory building construction. Observers educated to provide appreciative feedback when the workers performed the task safely and to offer constructive feedback to unsafe task performers. Baseline data of current safety performance was calculated before the BBS approach implementation and compared with the safety performance weekly data to identify the improvements.

In this research work, performance and emissions of Tyre Pyrolysis Oil (TPO) in a diesel engine are experimentally examined as per Indian Standard: 10000. The main objective of this research work is to find the best proportion of blend based on performance and emission analysis. For the study, Tyre Pyrolysis Oil is added to diesel fuel, numbered D100 (pure diesel), D95T5 (by volume of 5% TPO and 95% diesel), D90T10 (by volume of 10% TPO and 90% diesel), D85T15 (by volume of 15% TPO and 85% diesel), D80T20 (by volume of 20% TPO and 80% diesel) and D75T25 (by volume of 25% TPO and 75% diesel). Fuels are tested in four strokes, single cylinder, direct injection, water cooled diesel engine. The effect of various blends on Mechanical Efficiency, Specific Fuel Consumption (SFC) and Thermal Efficiency are investigated by the performance test. The influences of blends on CO, O₂, NO_x, CO₂ and HC are investigated by an emission test using the 5-gas analyzer. The investigation shows that D85T15 blend has been proved best based on performance test compared to other blends. The investigation of Emission analysis shows that D85T15 blend has better combustion characteristics compared to others.

The paper discusses about the wind tree turbine which is a type of vertical axis wind turbine Savonius model. The turbine will be attached to a manufactured tree that will be installed in and around any public area such as parks, roads, public facilities, or business offices. The initial phase discusses about the theoretical evaluation of available wind power for a single aeroleaf wind tree turbine. The second phase evaluates the pressure drop across the aeroleaf blade at the various velocity using CFD simulation. The simulation outcome shows that, pressure drop is directly proportional to the wind velocity which causes rise in the power generated at the shaft. The less pressure drop is produced up to some radius of the aeroleaf and increases as the radius of aeroleaf increased. In third phase of experiment work, design a new single aeroleaf for wind tree turbine to measure actual shaft power at different wind inlet velocity. Experiment performance conducted on a single aeroleaf at different input wind velocities to measure the aeroleaf, entire casing and overall efficiencies. The result shows that power co-efficient increases at beginning and highest reaches at 32% at inlet velocity of 19 m/s.

The large memory requirement becomes the challenge for the NGS technologies, as the memory is the bottleneck for every application. There is need to reduce the memory utilization for the de Bruijn graph, so as to it could fit in low memory space. This work provides the efficient memory utilization for the de Bruijn graph. The minimizer breaks the reads into numerous little partitions with the goal that every partition could be loaded into main memory one by one; they process separately then later on merge to form the simple path of de Bruijn graph. This reduces the space usage required during construction of de Bruijn graph.