3,231 research outputs found

    Effect of Tree Litter Application on Lowland Rice Yield in Bangladesh

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    The effect of tree litters on rice yield (cv. BR11) was evaluated in the study. Four kinds of tree litter, i.e., ipil-ipil or lamtoro (Leucaena leucocephala (Lamk) De Witt), sissoo (Dalbergia sissoo), akashmoni (Acacia auriculiformis) and mander (Erythrina orientalis) were incorporated into the soil 15 days before transplanting at rate of 5 ton/ha supplemented with inorganic fertilizers (83 kg N, 48 kg P205­, 42 kg K20, 10 kg S and 3.6 kg Zn/ha). In the control plots only recommended inorganic fertilizer were applied. Results showed that tree litter application had a significantly positive effect on the yield parameters such as plant height, panicle length, tillers per hill, filled grain and index of 1000-grain weight. Grain yield of plots treated with ipil-ipil, sissoo, akashmoni and mander was 5.61, 4.49, 4.95 and 5.36 ton/ha, and the yield increased over control plots 39.6, 11.7, 23.1 and 33.3%, respectively. It is worthy to note that addition of tree litter to inorganic fertilizer produced significantly higher yield than inorganic fertilizers solely. Among the tree litter, ipil-ipil and mander had the greatest increase in rice yield, while akashmoni was intermediate and sissoo was the least

    Emission Dispatch Problem with Cubic Function Considering Transmission Loss using Particle Swarm Optimization

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    In this research, authors have exploited particle swarm optimization (PSO) technique for solving the emission dispatch problem. Authors have used cubic function, instead of quadratic function, to solve emission dispatch problem to make the system more robust against nonlinearities of actual power generator. PSO with cubic function reveals better results by optimizing less emission of hazardous gases, transmission losses and showing robustness against nonlinearities than simplified direct search method (SDSM)

    Investigating Master-Slave Architecture for Underwater Wireless Sensor Network.

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    A significant increase has been observed in the use of Underwater Wireless Sensor Networks (UWSNs) over the last few decades. However, there exist several associated challenges with UWSNs, mainly due to the nodes' mobility, increased propagation delay, limited bandwidth, packet duplication, void holes, and Doppler/multi-path effects. To address these challenges, we propose a protocol named "An Efficient Routing Protocol based on Master-Slave Architecture for Underwater Wireless Sensor Network (ERPMSA-UWSN)" that significantly contributes to optimizing energy consumption and data packet's long-term survival. We adopt an innovative approach based on the master-slave architecture, which results in limiting the forwarders of the data packet by restricting the transmission through master nodes only. In this protocol, we suppress nodes from data packet reception except the master nodes. We perform extensive simulation and demonstrate that our proposed protocol is delay-tolerant and energy-efficient. We achieve an improvement of 13% on energy tax and 4.8% on Packet Delivery Ratio (PDR), over the state-of-the-art protocol

    Face mask mandates and risk compensation: an analysis of mobility data during the COVID-19 pandemic in Bangladesh

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    Introduction Concerns have been raised about the potential for risk compensation in the context of mask mandates for mitigating the spread of COVID-19. However, the debate about the presence or absence of risk compensation for universal mandatory mask-wearing rules—especially in the context of COVID-19—is not settled yet. Methods Mobility is used as a proxy for risky behaviour before and after the mask mandates. Two sets of regressions are estimated to decipher (any) risk-compensating effect of mask mandate in Bangladesh. These include: (1) intervention regression analysis of daily activities at six types of locations, using pre-mask-mandate and post-mandate data; and (2) multiple regression analysis of daily new COVID-19 cases on daily mobility (lagged) to establish mobility as a valid proxy. Results (1) Statistically, mobility increased at all five non-residential locations, while home stays decreased after the mask mandate was issued; (2) daily mobility had a statistically significant association on daily new cases (with around 10 days of lag). Both significances were calculated at 95% confidence level. Conclusion Community mobility had increased (and stay at home decreased) after the mandatory mask-wearing rule, and given mobility is associated with increases in new COVID-19 cases, there is evidence of risk compensation effect of the mask mandate—at least partially—in Bangladesh

    Investigation of the IoT Device Lifetime with Secure Data Transmission

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    This paper represents the approach for estimation of the lifetime of the IoT end devices. The novelty of this approach is in the taking into account not only the energy consumption for data transmission, but also for ensuring the security by using the encryption algorithms. The results of the study showed the effect of using data encryption during transmission on the device lifetime depending on the key length and the principles of the algorithm used

    Aircraft Cost Index and the Future of Carbon Emissions from Air Travel

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    Air travel accounts for 2% of global CO2 emissions and this proportion is set to grow in the future. There are currently no large scale solutions to drastically reduce the industry’s dependence on oil. Therefore, airlines are looking to use a basket of measures to reduce fuel consumption. Optimisation of the use of cost index (CI) could be a valuable addition to this. By balancing time-dependent costs with the cost of fuel, it controls the speed of the aircraft to achieve the most economic flight time. This has a direct impact on the CO2 emissions from the aircraft, with higher speeds resulting in higher fuel consumption. The aim of this study is to assess the impact that CI has on CO2 emissions for six different aircraft models on a flight-by-flight basis and to evaluate how the CI could be affected by future impacts on the industry for a representative aircraft. Results show that a range of representative CI values for different aircraft models exist and suggest that the maximum benefit for optimising CI values occurs for long range flights. The average saving in CO2 emissions is 1%. Results show that time-related costs have the greatest effect on the optimum CI values, particularly delay costs. On the fuel side of the equation it is notable that a carbon price resulting from the implementation of a market based mechanism has little impact on the optimum CI and only reduces CO2 emissions by 0.01% in this case. The largest savings in CO2 emissions result from the use of biofuels, with reductions of between 9% and 44% for 10% and 50% blends respectively. This study also highlights the need for further research into crew and maintenance costs, cumulative costs and delay induced by congestion and climate change events, as well as policy considerations to ensure that there is a reduction in CO2 emissions. The study concludes that CI should be seen as a valuable tool in both helping to reduce CO2 emissions, as well to assess the impact of future events on the industry
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