165 research outputs found
Dynamic Super Round Based Distributed Task Scheduling for UAV Networks
No full textNetworks of Unmanned Aerial Vehicles (UAVs) are emerging in many application domains, e.g., military surveillance. To perform collaborative tasks, the involved UAVs exchange several types of information, e.g., sensor data and commands. The major question here is how to schedule the tasks under dynamic traffic flows to provide network services. Existing solutions use the Round-Robin Strategy (RRS), where the tasks are scheduled statistically by dividing the time into fixed-length rounds. However, the RRS wastes significant network and device resources due to task scheduling in each round. This paper proposes DROVE – a novel clustering approach that allows the UAVs for dynamic task scheduling. However, determining the task scheduling is crucial, as it significantly affects several network parameters, e.g., throughput. Therefore, we devise the problem of distributed task scheduling under dynamic traffic flow scenarios to optimize the throughput. We propose a clustering task scheduling algorithm to serve dynamic traffic flows. Particularly, we integrate the dynamic traffic flows into the Lyapunov drift analysis framework, and determine the throughput optimality of our proposed scheduling algorithm. We perform extensive simulations to validate the effectiveness of DROVE. The results show that DROVE outperforms the state-of-the-art solutions in terms of energy consumption, clustering overhead, throughput, end-to-end delay, flow success rate and packet drop rate. </p
Potential and economic feasibility of solar home systems implementation in Bangladesh
No full textSolar home systems (SHSs) are the real hope for electrification of the off-grid areas in Bangladesh by utilizing the solar energy in renewable and sustainable basis. This paper demonstrates the solar energy prospect, the present status and dissemination schemes of SHSs in off-grid and coastal areas of Bangladesh by several government and Non-government organizations (NGOs). The country has an average daily solar radiation ranges between 4–6.5 kWh/m2. Currently, more than 3.8 million SHSs of capacity range 10–135 Wp (watt peak) with a total capacity of 150 MW have been disseminated in rural and isolated areas in Bangladesh. In this paper, ten case studies of capacity 20 Wp, 30 Wp and 42 Wp were investigated to evaluate economic viability at two randomly selected villages in Sirajgonj district and Jessore district, Bangladesh. The analysis showed that the SHSs for small business enterprise and household with small income generation are economically viable rather than only household lighting
Present Situation and Future Trend of Renewable Energy in South Asian Countries: A Review
No full textAuthor response
No full textThe Ca2+-sensor synaptotagmin-1 that triggers neuronal exocytosis binds to negatively charged membrane lipids (mainly phosphatidylserine (PtdSer) and phosphoinositides (Ptdlns)) but the molecular details of this process are not fully understood. Using quantitative thermodynamic, kinetic and structural methods, we show that synaptotagmin-1 (from Rattus norvegicus and expressed in Escherichia coli) binds to Ptdlns(4,5)P-2 via a polybasic lysine patch in the C2B domain, which may promote the priming or docking of synaptic vesicles. Ca2+ neutralizes the negative charges of the Ca2+-binding sites, resulting in the penetration of synaptotagmin-1 into the membrane, via binding of PtdSer, and an increase in the affinity of the polybasic lysine patch to phosphatidylinositol-4,5-bisphosphate (PtdIns(4,5)P-2). These Ca2+-induced events decrease the dissociation rate of synaptotagmin-1 membrane binding while the association rate remains unchanged. We conclude that both membrane penetration and the increased residence time of synaptotagmin-1 at the plasma membrane are crucial for triggering exocytotic membrane fusion
Recent trends and challenges of algal biofuel conversion technologies
No full textAzad, M ORCiD: 0000-0001-8258-6057The rapid growth in global energy demands has triggered the scientific community to explore new stepwise biofuel conversion approaches. Biofuels are considered as one of the most promising renewable alternatives to meet the global energy crisis and environmental concerns. Microalgae biomass has proven the potentiality for the production of biofuels, chemicals, and bio-based products leading to the transition from petroleum-based economy to a bio-based economy. Algal biofuel offers a number of advantages, for example, higher growth rate with no competition with food and minimal or no environmental impacts. Biofuel produced from microalgae has low viscosity and low density with high caloric value compared to cellulosic biofuel, which makes algal biofuel more suitable for the application. This chapter outlines the progress on the biofuels production from algal biomass. The process description of possible algal biofuel routes underlining the challenges associated with large-scale production have been detailed in this chapter
Static Anthropometric Characteristics of Bangladeshi Vehicle Driver: A Case Study
No full textBackground. Inappropriate design of sitting furniture and working equipment causes the serious musculoskeletal injuries and various pains as well as reducing working efficiency. Uncomfortable sitting posture in prolonged driving in Bangladesh is an issue to be solved immediately. Therefore, anthropometric databank of user population is significantly essential for the suitable dimensional design for avoiding these remarkable problems.Methods. This study analyses the anthropometric data of the Bangladeshi male vehicle driver aged between 30 and 60 years. A total of 210 Bangladeshi healthy drivers are considered for 15 anthropometric measurements and compared with the similar anthropometrics of other nationalities.Results.The mean stature and sitting height erect of Bangladeshi driver are 1645 mm and 843 mm, respectively. The mean of body mass index (BMI) of the drivers is 26.09 kg/m2, which indicates that the drivers are overweight. The mean stature of Bangladeshi driver is 17 mm shorter than the driver of Korea and 115 mm shorter than the driver of Iran.Conclusion. There are substantial differences between the body dimensions of Bangladeshi driver and similar dimensions of other countries. In comparison, Bangladeshi driver is found to be the shortest compared with the sample of other nationalities
Recent trends and challenges of algal biofuel conversion technologies
No full textThe rapid growth in global energy demands has triggered the scientific community to explore new stepwise biofuel conversion approaches. Biofuels are considered as one of the most promising renewable alternatives to meet the global energy crisis and environmental concerns. Microalgae biomass has proven the potentiality for the production of biofuels, chemicals, and bio-based products leading to the transition from petroleum-based economy to a bio-based economy. Algal biofuel offers a number of advantages, for example, higher growth rate with no competition with food and minimal or no environmental impacts. Biofuel produced from microalgae has low viscosity and low density with high caloric value compared to cellulosic biofuel, which makes algal biofuel more suitable for the application. This chapter outlines the progress on the biofuels production from algal biomass. The process description of possible algal biofuel routes underlining the challenges associated with large-scale production have been detailed in this chapter
Electrical energy conservation through human behavior change: Perspective in Bangladesh
No full textAll the existing energy sources have environmental, social and economic impacts. The greenhouse effect results global warming, air pollution and energy security have led to increasing interest and more development in energy conservation. Electrical energy conservation is one of them. In this paper, critical electrical energy situation in one of the developing countries in the world, Bangladesh was considered in general. It is possible to serve maximum number of electrical energy consumers by maintaining proper use of the electrical energy. During hot summer the electrical power shortage is about 1000 MW to 1500 MW each year. If energy conservation is achieved through human behavior change, around 390 GWh of electrical energy per month and 4,683 GWh per year can be saved in Bangladesh. A related case study is conducted for this study and a bottom up method is used to conduct this study. The case study and many other literature shows that it is possible to save the electrical energy through behavior change from 3% to 20%
Techno-economic analysis of ionic liquid pre-treatment integrated pyrolysis of biomass for co-production of furfural and levoglucosenone
No full textTechno-economic analysis of ionic liquid pre-treatment integrated pyrolysis of biomass for co-production of furfural and levoglucosenon
Techno-economic analysis of ionic liquid pre-treatment integrated pyrolysis of biomass for co-production of furfural and levoglucosenone
No full textIn the current work, a techno-economic analysis of pyrolysis of choline glycinate pre-treated biomass has been presented for the co-production of furfural and levoglucosenone along with hemicellulose, lignin and biochar as other byproducts. The mass balance suggested that the 1800 kg/h dry sugarcane straw biorefinery plant could produce about 260 kg/h furfural and 65 kg/h levoglucosenone. The minimum selling price of furfural and levoglucosenone were also estimated and the values were 1640 and 3590 AU NPV with a payback period of 15.4 years. The sensitivity analysis suggested that biomass loading, ionic liquid recycling and cost, waste heat recovery, furfural yield, interest rate and capital cost are the major influential factors for both the minimum selling price of furfural and levoglucosenone
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