26 research outputs found
Design and concept of renewable energy driven auto-detectable railway level crossing systems in Bangladesh
Bangladesh’s railway system mostly uses typical manual railway crossing techniques or boom gates through its 2955.53 km rail route all over the country. Accidents frequently happen at railway crossings due to the lack of quickly operating gate systems, and to fewer safety measures at the railway crossing as well. Currently, there are very few automatic railway crossing systems available (without obstacle detectors). Additionally, all of them are dependent on the national power grid, without a backup plan for any emergency cases. Bangladesh is still running a bit behind in generating enough power for its consumption; hence, it is not possible to have a continuous power supply at all times all over the countryside. We aim to design and develop a smart railway crossing system with an obstacle detector to prevent common types of accidents at railway crossing points. We use two infrared (IR) sensors to operate the railway crossing systems, which are controlled by an Arduino Uno. This newly designed level crossing system is run with the help of sustainable renewable energy, which is cost-effective and eco-friendly, and applied under the national green energy policy towards achieving sustainable development in Bangladesh as a part of the global sustainable goal to face climate change challenges. We have summarized the simulated the results of several renewable energy sources, including a hybrid system, and optimized the Levelized Cost of Energy (LCOE) and the payback periods
Adaptation to flooding in low‐income urban settlements in the least developed countries: A systems approach
This study aims to use a whole systems approach (1) to understand the processes of adaptation to flooding of the urban poor; (2) to identify new knowledge of how low‐income settlements might better adapt to climatic risks; and (3) to begin to develop appropriate guidance on this. Low‐income urban settlements in the least developed countries (LDCs) present an extreme case where catastrophic natural hazards and chronic social hazards overlap. These low‐income urban populations face the greatest adaptation challenges as they often occupy informal settlements that are particularly exposed to hazards, and have multiple vulnerabilities arising from their lack of basic services. There is a dynamic complexity of issues arising from the many levels of actor involved and multiple social and physical factors. Analysing such a complex phenomenon calls for a specific conceptual framing, and a systems theory approach is suggested to provide a holistic perspective. The case study for this research is located in Dhaka East, where there is both high vulnerability to flooding, and a significant low‐income population. The research has adopted a mixed methods approach involving different data collection methods governed by the different scales and actors being investigated. The research develops new systems understandings of perceptions and experiences of the local population about adaptation processes in low‐income urban settlements, and how these processes may be positively influenced by integrating bottom‐up and top‐down approaches
Finite element modeling of steel piles and suction caissons in sand under lateral and inclined load
The behavior of a steel pipe pile in sand subjected to lateral load is examined by three-dimensional finite element (FE) analyses using the commercially available software package ABAQUS/Standard 6.10 EF1. The sand around the pile is modeled using a modified form of Mohr-Coulomb soil model. The modifications involve the nonlinear variation of elastic soil modulus with mean stress and the variation of mobilized angle of internal friction and dilation angle with plastic shear strain, which are implemented in ABAQUS/Standard using a user subroutine. Numerical analyses are also performed by using the LPILE software which is based on the p-y curve approach and widely used in design for estimating lateral load capacity of pile foundations. The FE and LPILE results are compared with the results of two full-scale tests available in the literature. It is shown that the FE model better simulates the response of a pile under lateral load. Comparing the numerical results with the full-scale test results, some limitations of the p-y curve method are highlighted. -- In the second part of the study, finite element analyses are performed to estimate the pullout capacity of a suction caisson subjected to oblique loading. Three-dimensional finite element analyses are performed using ABAQUS/Standard 6.10 EF1 finite element software. The effects of two key variables, loading angle and mooring line position, are investigated. The finite element results are compared with centrifuge test results available in the literature. The maximum pullout capacity is obtained when the mooring line is attached at approximately 75% depth of the caisson for the cases analyzed in this study
Design and Concept of Renewable Energy Driven Auto-Detectable Railway Level Crossing Systems in Bangladesh
Bangladesh’s railway system mostly uses typical manual railway crossing techniques or boom gates through its 2955.53 km rail route all over the country. Accidents frequently happen at railway crossings due to the lack of quickly operating gate systems, and to fewer safety measures at the railway crossing as well. Currently, there are very few automatic railway crossing systems available (without obstacle detectors). Additionally, all of them are dependent on the national power grid, without a backup plan for any emergency cases. Bangladesh is still running a bit behind in generating enough power for its consumption; hence, it is not possible to have a continuous power supply at all times all over the countryside. We aim to design and develop a smart railway crossing system with an obstacle detector to prevent common types of accidents at railway crossing points. We use two infrared (IR) sensors to operate the railway crossing systems, which are controlled by an Arduino Uno. This newly designed level crossing system is run with the help of sustainable renewable energy, which is cost-effective and eco-friendly, and applied under the national green energy policy towards achieving sustainable development in Bangladesh as a part of the global sustainable goal to face climate change challenges. We have summarized the simulated the results of several renewable energy sources, including a hybrid system, and optimized the Levelized Cost of Energy (LCOE) and the payback periods.</jats:p
Design and concept of renewable energy driven auto-detectable railway level crossing systems in Bangladesh
Bangladesh’s railway system mostly uses typical manual railway crossing techniques or boom gates through its 2955.53 km rail route all over the country. Accidents frequently happen at railway crossings due to the lack of quickly operating gate systems, and to fewer safety measures at the railway crossing as well. Currently, there are very few automatic railway crossing systems available (without obstacle detectors). Additionally, all of them are dependent on the national power grid, without a backup plan for any emergency cases. Bangladesh is still running a bit behind in generating enough power for its consumption; hence, it is not possible to have a continuous power supply at all times all over the countryside. We aim to design and develop a smart railway crossing system with an obstacle detector to prevent common types of accidents at railway crossing points. We use two infrared (IR) sensors to operate the railway crossing systems, which are controlled by an Arduino Uno. This newly designed level crossing system is run with the help of sustainable renewable energy, which is cost-effective and eco-friendly, and applied under the national green energy policy towards achieving sustainable development in Bangladesh as a part of the global sustainable goal to face climate change challenges. We have summarized the simulated the results of several renewable energy sources, including a hybrid system, and optimized the Levelized Cost of Energy (LCOE) and the payback periods
Design and concept of renewable energy driven auto-detectable railway level crossing systems in Bangladesh
Bangladesh’s railway system mostly uses typical manual railway crossing techniques or boom gates through its 2955.53 km rail route all over the country. Accidents frequently happen at railway crossings due to the lack of quickly operating gate systems, and to fewer safety measures at the railway crossing as well. Currently, there are very few automatic railway crossing systems available (without obstacle detectors). Additionally, all of them are dependent on the national power grid, without a backup plan for any emergency cases. Bangladesh is still running a bit behind in generating enough power for its consumption; hence, it is not possible to have a continuous power supply at all times all over the countryside. We aim to design and develop a smart railway crossing system with an obstacle detector to prevent common types of accidents at railway crossing points. We use two infrared (IR) sensors to operate the railway crossing systems, which are controlled by an Arduino Uno. This newly designed level crossing system is run with the help of sustainable renewable energy, which is cost-effective and eco-friendly, and applied under the national green energy policy towards achieving sustainable development in Bangladesh as a part of the global sustainable goal to face climate change challenges. We have summarized the simulated the results of several renewable energy sources, including a hybrid system, and optimized the Levelized Cost of Energy (LCOE) and the payback periods
Design and Concept of Renewable Energy Driven Auto-Detectable Railway Level Crossing Systems in Bangladesh
Bangladesh’s railway system mostly uses typical manual railway crossing techniques or boom gates through its 2955.53 km rail route all over the country. Accidents frequently happen at railway crossings due to the lack of quickly operating gate systems, and to fewer safety measures at the railway crossing as well. Currently, there are very few automatic railway crossing systems available (without obstacle detectors). Additionally, all of them are dependent on the national power grid, without a backup plan for any emergency cases. Bangladesh is still running a bit behind in generating enough power for its consumption; hence, it is not possible to have a continuous power supply at all times all over the countryside. We aim to design and develop a smart railway crossing system with an obstacle detector to prevent common types of accidents at railway crossing points. We use two infrared (IR) sensors to operate the railway crossing systems, which are controlled by an Arduino Uno. This newly designed level crossing system is run with the help of sustainable renewable energy, which is cost-effective and eco-friendly, and applied under the national green energy policy towards achieving sustainable development in Bangladesh as a part of the global sustainable goal to face climate change challenges. We have summarized the simulated the results of several renewable energy sources, including a hybrid system, and optimized the Levelized Cost of Energy (LCOE) and the payback periods
Antioxidant potential of common leafy vegetables in Bangladesh
Amount of polyphenols, flavonoids, anthocyanins in ethanol extracts and antioxidant activity of both ethanol and lipophilic extracts of common leafy vegetables in Bangladesh were compared. Among the 12 leafy vegetables, Ipomoea aquatica Forssk. showed the highest content of total polyphenols (38.9 mg gallic acid equivalent (GAE)/g extract) and flavonoids (23.2 mg (+)-catechin equivalent (CE)/g extract). Highest anthocyanins content was found in Amaranthus gangeticus L. (1.15 ?mol/g extract) followed by Pisum sativum L. (0.85 ?mol/g extract). Ethanol extracts of Brassica campestris L., Enhydra fluctuans Lour., I. aquatica, Lagenaria siceraria (Mol.) Standl. and P. sativum exhibited high DPPH free radical scavenging activity with IC50 of 104.2, 85.5, 26.9, 125 and 68.5 ?g/ml, respectively whereas for the same lipophilic pentane extracts of Basella alba L. showed the lowest (68.4 ?g/ml) IC50 followed by I. aquatica (70.4 ?g/ml), E. fluctuans (75.7 ?g/ml), L. siceraria (78.3 ?g/ml) and B. campestris (80.6 ?g/ml). I. aquatica also showed the highest NO free radical scavenging followed by B. campestris and B. alba. Highest reducing power (O.D. = 1.7) was observed for I. aquatica followed by P. sativum (O.D. = 1.12), B. alba (O.D. = 0.86) and L. siceraria (O.D. = 0.72) at 400 ?g/ml extract. They also displayed high total antioxidant capacity. Therefore, the top five potential leafy vegetables consist of both hydrophilic and lipophilic antioxidant(s), the order being I. aquatica > B. campestris > B. alba > P. sativum > and L. siceraria. DOI: http://dx.doi.org/10.3329/bjb.v44i1.22723 Bangladesh J. Bot. 44(1): 51-57, 2015 (March)</jats:p
