Cloning and expression of α-amylase in E. coli: genesis of a superior biocatalyst for substrate-specific MFC

One of the most practical approaches for establishing a successful microbial fuel cell (MFC) is to fasten the oxidation rate of the substrate by the microorganisms to get quick paced electron transfer between microbes and electrode. A genetically modified Escherichiacoli, overexpressing α-amylase, is constructed and applied as biocatalyst in MFC using starch as substrate. The results are compared with nonrecombinant, native E.coli. The results show better performance for the MFC containing the recombinant strain demonstrated by higher power density (PD), lower resistance, and significant electrochemical activity. Maximum PD has been recorded as 279.04 mW m^?2 compared to 120.33 Mw m^?2 for the MFC operated with nonrecombinant E.coli. The impedance results also suggest the effectiveness of the recombinant strain by lowering the internal resistance by more than half order as compared to the nonrecombinant one. These results affirm that the engineered strain can be used as a superior biocatalyst in contrast to the native strain and by using the technique of genetic alteration; gene of interest can be inserted based on the substrate to be treated. So, this work gives a useful insight for accomplishing successful MFC operation with the use of bacterial stains engineered at the molecular level.     

Effect of different design aspects of pipe for earth air tunnel heat exchanger system: A state of art

Earth air tunnel heat exchanger (EATHE) is a promising passive technique to provide thermal comfort condition in buildings. EATHE system uses undisturbed temperature of the ground for heating/cooling of air. Despite the several advantages, this technique has not become much popular owing to its high capital cost (mainly pipe cost and trench excavation cost) and large land area requirements. The primary objective of this study is to present a comprehensive review of different EATHE pipe layouts, pipe properties and positioning of the pipe with their advantages and limitations. It is observed that the ring pipe layout is the most cost-effective pipe-layout for small size EATHE system because it saves excavation cost by using a trench of the existing foundation of the building. However, Grid pipe-layout is an ideal layout for a large size EATHE system. Multi-layer pipe layouts should be used to reduce the land area requirement significantly. Moreover, EATHE system can be installed beneath the building (under building foot-print) to eliminate extra land area requirement for the installation of EATHE system. This review article shows that the Initial capital cost and land area requirement for the EATHE system can be substantially reduced by using appropriate pipe layout. It can be concluded that if EATHE system is installed with proper design strategies, it will be a clean and cost-effective method for building heating/cooling with significant power savings.     

南京市两次秋季污染过程及成因分析

为探究南京秋季污染过程的特征和影响因素,利用MODIS(Moderate Resolution Imaging Spectroradiometer)传感器获得的气溶胶光学厚度(Aerosol Optical Depth)、波长指数(Angstrom Exponent)、火点数据及CALIPSO(Cloud-Aerosol Lidar And Infrared Pathfinder Satellite Observations)卫星数据和来自NECP、MICAPS的温度、相对湿度、风向风速等常规气象要素数据,对南京2015年10月、2016年9月两次污染过程进行分析.研究结果表明:两次污染过程的AE412-470值(埃斯特朗波长指数α)均高于1,由此判断两次污染均以人为排放产生的细粒子为主.但2015年10月的AE412-470值明显低于2016年9月,说明在2015年10月污染过程中粗粒子所占比重高于2016年9月.结合对后向轨迹的分析发现,南京地区2015年10月污染天气的发生还受长距离输送的影响,污染源主要为来自内蒙古、山西等地的污染型沙尘粒子.研究还发现,较高的相对湿度、较低的地表风速、低混合层高度及贴地逆温等气象条件会导致污染物难以扩散稀释而累积在南京地区,造成该区域在秋季出现较严重的污染天气.     

Climate change impact and potential adaptation strategies under alternate climate scenarios for yam production in the sub-humid savannah zone of West Africa

Globally, yam (Dioscorea spp.) is the fifth most important root crop after sweet potatoes (Ipomoea batatas L.) and the second most important crop in Africa in terms of production after cassava (Manihot esculenta L.) and has long been vital to food security in sub-Saharan Africa (SSA). Climate change is expected to have its most severe impact on crops in food insecure regions, yet very little is known about impact of climate change on yam productivity. Therefore, we try estimating the effect of climate change on the yam (variety: Florido) yield and evaluating different adaptation strategies to mitigate its effect. Three regional climate models REgional MOdel (REMO), Swedish Meteorological and Hydrological Institute Regional Climate Model (SMHIRCA), and Hadley Regional Model (HADRM3P) were coupled to a crop growth simulation model namely Environmental Policy Integrated Climate (EPIC) version 3060 to simulate current and future yam yields in the Upper Ouémé basin (Benin Republic). For the future, substantial yield decreases were estimated varying according to the climate scenario. We explored the advantages of specific adaptation strategies suggesting that changing sowing date may be ineffective in counteracting adverse climatic effects. Late maturing cultivars could be effective in offsetting the adverse impacts. Whereas, by coupling irrigation and fertilizer application with late maturing cultivars, highest increase in the yam productivity could be realized which accounted up to 49 % depending upon the projection of the scenarios analyzed.     

Application of artificial neural network for prediction of Pb(II) adsorption characteristics

The adsorption of Pb(II) onto the surface of microwave-assisted activated carbon was studied through a two-layer feedforward neural network. The activated carbon was developed by microwave activation of Acacia auriculiformis scrap wood char. The prepared adsorbent was characterized by using Brunauer–Emmett–Teller (BET) surface area analyzer, scanning electron microscope (SEM), and X-ray difractometer. In the present study, the input variables for the proposed network were solution pH, contact time, initial adsorbate concentration, adsorbent dose and temperature, whereas the output variable was the percent Pb(II) removal. The network had been trained by using different algorithms and based on the lowest mean squared error (MSE) value and validation error, resilient backpropagation algorithm with 12 neurons in the hidden layer was selected for the present investigation. The tan sigmoid and purelin transfer function were used in the hidden and the output layers of the proposed network, respectively. The model predicted and experimental values of the percent Pb(II) removal were also compared and both the values were found to be in reasonable agreement with each other. The performance of the developed network was further improved by normalizing the experimental data set and it was found that after normalization, the MSE and validation error were reduced significantly. The sensitivity analysis was also performed to determine the most significant input parameter.     

Perceptions of incentives for participation: insights from joint forest management in India

The participatory approach in management of forests is now well established in forest policies of many developing countries. Incentives for different groups to participate have been argued by many to be desirable characteristics to promote participation. A key challenge for government and donor agencies is to develop better understanding of the incentives for different groups to be able to achieve and sustain their participation. Based on a case study of a joint forest management (JFM) programme in the northern state of Haryana in India, this paper highlights the relevance of understanding people's perception of the incentives. It specifically examines three hypotheses related to perceptions of villagers about incentives offered under the JFM programme and relates them to their participation in joint management. It concludes that a better understanding is likely to help in improving project implementation at the local level and the design of participatory forest management programmes more generally.     

Diversity of gastropods at Pudhumadam coast region and unusual occurrence of Tetraclita rubescens on conus shell

The marine environment is continuously subjected to chemical pollution, which may exert a detrimental effect on aquatic organisms. Biodiversity of marine invertebrates has been proven to be difficult to assess accurately using traditional morphological methods. Major problems include dearth of characters in many taxa. Hence, it is necessary to assess the eco-health of this marine invertebrate using reliable measurements of environmental quality as required in the present study. With the backdrop of information, the Pudhumadam coastal area was surveyed for the diversity of ruined/washed out gastropods species. As a competitor for space with gastropods, these barnacles settle on the conus for its food and habitat. In our study, the occurrence of acorn barnacles was observed on gastropod shells. The pink adult and many white small barnacles were noted on the shells. If these barnacles increase their habitat this may lead to destruction of diversity of gastropods.