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Experiments were carried out to evaluate the toxicity of six botanicals, Bazna (Zanthoxylum rhetsa), Ghora-neem (Melia sempervirens), Hijal (Barringtonia acutangula), Karanja (Pongamia pinnata), Mahogoni (Swietenia mahagoni) and Neem (Azadirachta indica) against red flour beetle, Tribolium castaneum Herbst. Leaf and seed extracts were prepared by using acetone, methanol and water as solvents. The results showed that extracts of all the six plants had direct toxic effect on red flour beetle. Among them, Neem seed extract showed the highest toxic effect (mortality, 52.50%), whereas Hijal leaf extract possessed the lowest toxic effect (mortality, 22.24%). Among the solvents, acetone extract showed more toxic effect than other extracts. Seed extracts of respective plants were slightly more toxic than leaf extract. The effectiveness of most of the plant extracts increased proportionally with the increase of doses and decreased with time. Keywords: Plant extracts; Toxicity; Red flour beetleDOI: 10.3329/jbau.v7i1.4789 J. Bangladesh Agril. Univ. 7(1): 1-5, 2009

The Ganges-Brahmaputra-Meghna (GBM) delta is one of the world's largest deltas. It is currently experiencing high rates of relative sea-level rise of about 5 mm/year, reflecting anthropogenic climate change and land subsidence. This is expected to accelerate further through the 21st Century, so there are concerns that the GBM delta will be progressively submerged. In this context, a core question is: can sedimentation on the delta surface maintain its elevation relative to sea level? This research seeks to answer this question by applying a two-dimensional flow and morphological model which is capable of handling dynamic interactions between the river and floodplain systems and simulating floodplain sedimentation under different flow-sediment regimes and anthropogenic interventions. We find that across a range of flood frequencies and adaptation scenarios (including the natural polder-free state), the retained volume of sediment varies between 22% and 50% of the corresponding sediment input. This translates to average rates of sedimentation on the delta surface of 5.5 mm/yr to 7.5 mm/yr. Hence, under present conditions, sedimentation associated with quasi-natural conditions can exceed current rates of relative sea-level rise and potentially create new land mass. These findings highlight that encouraging quasi-natural conditions through the widespread application of active sediment management measures has the potential to promote more sustainable outcomes for the GBM delta. Practical measures to promote include tidal river management, and appropriate combinations of cross-dams, bandal-like structures, and dredging.

Too much or too little water is always a challenge for any water related issue, especially for developing countries where water is abundant or crisis like Bangladesh with the change of circumstances. Dhaka the capital of Bangladesh is facing a serious water scarcity problem due to the big gap between demand and supply of water system. On the other hand it can be say that this water crisis originated due to too much water like floods, rainfall, drought etc. that force rural people from other part of country towards city and city is losing its hydrological balance to accommodate these unwanted migrated people. Dhaka has experiencing a tremendous pressure and transformation in terms of its water system due to such unmanageable urban growth and uncontrolled urbanization. Design strategies and solution are needed to respond for pressing climate and environmental changes and necessary to take action against the ubiquitous human mismanagement of the essential resource of water. To overcome these water related problem water can be a designing element for structuring future development with the combination of sustainable approaches for social and physical transformation, open up opportunities for land water management system. This paper will try to find the changing relation between the city and its water system. Using Kamrangir chor a water linked suburb in Dhaka as an experimental site this paper will also frame some urban design strategies for reducing water damages, revitalize water sources, productive water parks, which will structure new water based urban development.

Rapid urbanization combined with high economic growth, industrialization, and changes in socio-economic conditions increase the quantity of municipal solid waste. Cities located in South-Asia are facing serious issues due to waste, with countries like India, Bangladesh, and Pakistan top of the list of bad waste management. The increasing generation of solid waste and also the improper management of waste in Bangladesh leads to environmental degradation. Current waste management practice in Bangladesh is so weak that day by day it is harming the climate and creating a lot of unwanted situations. This research consists of an examination of the current administrative measures and presents another proposition for the executive cycle to decrease ecological contamination. The research study aims to decrease the amount of waste being dumped into municipal sanitary landfill sites & converting the waste into energy which is both financially and environmentally suitable by involving unemployed people in the management system. The results of this study will give an idea of how waste can be utilized as a resource and how this resource can be a capital good as well as how the local level problems can be solved by taking some strategies and making our environment suitable for future generations.

Abstract In the context of the rural electrification challenge, sharing-based nanogrids represent an innovative approach for affordable and sustainable electricity. The peer-to-peer topology of these nanogrids is targeted at organic growth and thus requires real time monitoring and optimization. A data analysis tool has been developed, aiming at achieving an efficient power flow and real time optimization of generation, storage, load and distribution capacities. This paper elaborates the core algorithms of the network topology optimization and provides first results based on data from a pilot nanogrid in Bangladesh.

Les insectes nuisibles sont un problème très courant dans les jardins de thé où ils causent une perte énorme chaque année. L'étude a été menée pour mesurer le potentiel d'un piège à lumière LED solaire en tant que technologie de lutte antiparasitaire respectueuse de l'environnement dans le jardin de thé du Bangladesh. Les résultats ont montré que le plus grand nombre d'insectes des ordres des coléoptères (3526) et des hémiptères (557) était capturé sous le piège à lumière LED solaire alors qu'il était le plus faible chez les hyménoptères (47) et les orthoptères (3). Les résultats de l'étude ont également indiqué que sur une moyenne de 9 jours, le nombre total d'insectes capturés était de 725, 244, 146, 112 et 85 à 6-7, 7-8, 8-9, 9-10 et 22-11 heures, respectivement, alors qu'il était de 656, 1004, 566, 3970, 602, 489, 680, 620 et 3222 du 1er au 9e jour, respectivement. Par conséquent, le taux décroissant moyen avec le temps (horaire) a été calculé à 66,34, 40,16, 23,29 et 24,11 % par rapport à la 1ère heure (18h-19h). Le patron moyen de capture des insectes par rapport aux 1ers jours a été diminué ou vice-versa. De 18h00 à 11h00, l'intensité lumineuse initiale a été mesurée à 28 lux, ce qui a augmenté jusqu'à 245 lux à 20h00, puis a considérablement diminué. L'intensité lumineuse a une relation positive avec la capture des insectes. La plupart des insectes coléoptères et hémiptères ont été capturés sous faible intensité lumineuse en début de soirée (18h00). Par conséquent, l'étude a suggéré que le piège à lumière LED à base solaire pourrait avoir le potentiel de réduire un grand nombre de parasites du thé dans le jardin de thé. Las plagas de insectos son un problema muy común en el jardín de té, donde causan una gran pérdida cada año. El estudio se realizó para medir la potencialidad de una trampa de luz LED basada en energía solar como una tecnología de manejo de plagas ecológica en el jardín de té de Bangladesh. Los resultados mostraron que el mayor número de insectos de los órdenes Coleoptera (3526) y Hemiptera (557) se capturaron bajo la trampa de luz LED basada en energía solar, mientras que fue más bajo en Hymenoptera (47) y Orthoptera (3). Los resultados del estudio también indicaron que en un promedio de 9 días, el total de insectos capturados (número) fue de 725, 244, 146, 112 y 85 a las 6-7, 7-8, 8-9, 9-10 y 10-11 pm, respectivamente, mientras que fue de 656, 1004, 566, 3970, 602, 489, 680, 620 y 3222 en los días 1 a 9, respectivamente. Por lo tanto, la tasa media de disminución con el tiempo (por hora) se calculó en 66.34, 40.16, 23.29 y 24.11% en comparación con la 1ª hora (6-7 pm). El patrón medio capturado de los insectos en comparación con los primeros días disminuyó o viceversa. De 6:00 p. m. a 11:00 a. m., la intensidad de la luz inicial se midió a 28 lux, que se elevó hasta 245 lux a las 8:00 p. m., después de lo cual se redujo drásticamente. La intensidad de la luz tiene una relación positiva con la captura de insectos. La mayoría de los insectos coleópteros y hemípteros fueron capturados bajo baja intensidad de luz en la tarde (6.00 pm). Por lo tanto, el estudio sugirió que la trampa de luz LED basada en energía solar podría tener el potencial de reducir una gran cantidad de plagas de té en el jardín de té. Insect pest is a very common problem in tea garden where they caused a huge loss in each year. The study was conducted to measure the potentiality of a solar based LED light trap as an eco-friendly pest management technology in the tea garden of Bangladesh. The results showed that the highest number of insects from Coleoptera (3526) and Hemiptera (557) orders were captured under the solar based LED light trap while it was lowest in Hymenoptera (47) and Orthoptera (3). The study results also indicated that in an average of 9 days, total captured insects (number) were 725, 244, 146, 112, and 85 at 6-7, 7-8, 8-9, 9-10, and 10-11 pm, respectively while it was 656, 1004, 566, 3970, 602, 489, 680, 620 and 3222 at 1st to 9th days, respectively. Hence, the average decreasing rate with time (hourly) was computed at 66.34, 40.16, 23.29, and 24.11% compared to the 1st hour (6-7 pm). The average captured pattern of the insects compared to the 1st days was decreased or vice-versa. From 6.00 pm to 11.00 am, the initial light intensity was measured at 28 lux which raised up to 245 lux at 8.00 pm after that it down drastically. Light intensity has a positive relation with insect capture. Most of the Coleopteran and Hemipteran insects were captured under low light intensity in the early evening (6.00 pm). Therefore, the study suggested that the solar based LED light trap might have the potential to reduce a great number of tea pests in the tea garden. الآفات الحشرية هي مشكلة شائعة جدا في حديقة الشاي حيث تسببت في خسارة كبيرة في كل عام. أُجريت الدراسة لقياس إمكانات مصيدة إضاءة LED القائمة على الطاقة الشمسية كتقنية صديقة للبيئة لإدارة الآفات في حديقة الشاي في بنغلاديش. وأظهرت النتائج أن أكبر عدد من الحشرات من غمديات الأجنحة (3526) ونصف الأجنحة (557) تم التقاطها تحت فخ ضوء LED الشمسي بينما كان أدنى مستوى في غشاء البكارة (47) و Orthoptera (3). كما أشارت نتائج الدراسة إلى أنه في متوسط 9 أيام، بلغ إجمالي الحشرات التي تم اصطيادها (العدد) 725 و 244 و 146 و 112 و 85 في 6-7 و 7-8 و 8-9 و 9-10 و 10-11 مساءً، على التوالي، بينما كان 656 و 1004 و 566 و 3970 و 602 و 489 و 680 و 620 و 3222 في الأيام من الأول إلى التاسع على التوالي. وبالتالي، تم حساب متوسط معدل التناقص مع الوقت (بالساعة) عند 66.34 و 40.16 و 23.29 و 24.11 ٪ مقارنة بالساعة الأولى (6-7 مساءً). انخفض متوسط النمط الذي تم التقاطه من الحشرات مقارنة بالأيام الأولى أو العكس. من الساعة 6:00 مساءً إلى الساعة 11:00 صباحًا، تم قياس شدة الضوء الأولية عند 28 لوكس والتي ارتفعت إلى 245 لوكس في الساعة 8:00 مساءً بعد ذلك انخفضت بشكل كبير. شدة الضوء لها علاقة إيجابية مع التقاط الحشرات. تم التقاط معظم حشرات غمدية الأجنحة ونصف الأجنحة تحت شدة الإضاءة المنخفضة في وقت مبكر من المساء (6.00 مساءً). لذلك، أشارت الدراسة إلى أن مصيدة ضوء LED القائمة على الطاقة الشمسية قد يكون لها القدرة على تقليل عدد كبير من آفات الشاي في حديقة الشاي.

Ionic liquids (ILs) are molten salts that are entirely composed of ions and have melting temperatures below 100 °C. When immobilized in polymeric matrices by sol–gel or chemical polymerization, they generate gels known as ion gels, ionogels, ionic gels, and so on, which may be used for a variety of electrochemical applications. One of the most significant research domains for IL-based gels is the energy industry, notably for energy storage and conversion devices, due to rising demand for clean, sustainable, and greener energy. Due to characteristics such as nonvolatility, high thermal stability, and strong ionic conductivity, IL-based gels appear to meet the stringent demands/criteria of these diverse application domains. This article focuses on the synthesis pathways of IL-based gel polymer electrolytes/organic gel electrolytes and their applications in batteries (Li-ion and beyond), fuel cells, and supercapacitors. Furthermore, the limitations and future possibilities of IL-based gels in the aforementioned application domains are discussed to support the speedy evolution of these materials in the appropriate applicable sectors.