899 research outputs found

    Earth Pipe Cooling Strategy in Buildings: A Sustainable Approach

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    Abundant energy supply is one of the preconditions of economic growth, however, the economic growth in turn leads to higher energy consumption to support higher living standard. The energy demand is increasing at an alarming rate throughout the world, which may lead to scarcity of energy in near future. Most of this energy is used in buildings for heating and cooling. Therefore, it is important to adopt a system to save energy in buildings without using any habitual mechanical devices. Passive air cooling is such a system assists us to save energy in passive process. Earth pipe cooling strategy is one of them, which can cool a space with minimal energy. In this strategy, air comes through a pipe inlet and passes underground via buried pipes, transfers heat to the earth (soil), gets cooler and goes to the room through pipe outlet. This paper reviews the earth pipe cooling performance in different climates by an intensive literature survey. The performance was also compared with other common passive air cooling strategies used in buildings. The findings of the study recommend an optimum passive air cooling guidelines, and passive air cooling products to the occupants of the buildings. Keywords: Cooling Performance; Passive Air Cooling; Energy Consumption

    Modelling Li+ Ion Battery Electrode Properties

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    We formulated two detailed models for an electrolytic cell with particulate electrodes based on a lithium atom concentration dependent Butler-Volmer condition at the interface between electrode particles and the electrolyte. The first was based on a dilute-ion assumption for the electrolyte, while the second assumed that Li ions are present in excess. For the first, we used the method of multiple scales to homogenize this model over the microstructure, formed by the small lithium particles in the electrodes. For the second, we gave rigorous bounds for the effective electrochemical conductivity for a linearized case. We expect similar results and bounds for the "full nonlinear problem" because variational results are generally not adversely affected by a sinh term. Finally we used the asymptotic methods, based on parameters estimated from the literature, to attain a greatly simplified one-dimensional version of the original homogenized model. This simplified model accounts for the fact that diffusion of lithium atoms within individual electrode particles is relatively much faster than that of lithium ions across the whole cell so that lithium ion diffusion is what limits the performance of the battery. However, since most of the potential drop occurs across the Debye layers surrounding each electrode particle, lithium ion diffusion only significantly affects cell performance if there is more or less complete depletion of lithium ions in some region of the electrolyte which causes a break in the current flowing across the cell. This causes catastrophic failure. Providing such failure does not occur the potential drop across the cell is determined by the concentration of lithium atoms in the electrode particles. Within each electrode lithium atom concentration is, to leading order, a function of time only and not of position within the electrode. The depletion of electrode lithium atom concentration is directly proportional to the current being drawn off the cell. This leads one to expect that the potential of the cell gradually drops as current is drawn of it. We would like to emphasize that all the homogenization methods employed in this work give a systematic approach for investigating the effect that changes in the microstructure have on the behaviour of the battery. However, due to lack of time, we have not used this method to investigate particular particle geometries

    Study of a two steps process for the valorization of PVC-containing wastes

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    Published online 27 November 2012The presence of organic compounds in wastes, namely polymer based compounds, is considered a potential relevant source of energy. However, the presence of polyvinyl chloride (PVC) in their composition, causes recycling problems when a thermal process is considered for the wastes treatment [1] preventing its use on processes which the main goal is the energy recovery (Zevenhoven et al. in Fuel 81:507–510, 2002; Kim in Waste Manag 21:609–616, 2001). A possible solution should consider a first step for chlorine removal, through a pyrolysis process previously to a subsequent thermal treatment, for energetic valorization. The present work assesses a possible process for treating PVC-containing wastes in an environmentally friendly way. It is based on the effective de-chlorination of PVC-containing wastes through a pyrolysis process at low temperature before the carbonaceous residue (chlorine free fraction) being subjected to a subsequent thermal treatment for energetic valorization with the production of a synthesis gas (syngas). In the end of the process concentrated hydrochloric acid or other chlorine solutions and a syngas, with high energetic potential are obtained. The synthesis gas produced can be used in turbines or gas engines, replacing the gases obtained from fossil non-renewable resources. The validation of the proposed treatment of PVC-containing wastes in pilot scale has also been performed

    Development of screening techniques and identification of new sources of resistance to Ascochyta blight disease of chickpea

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    Effective controlled-environment and field screening techniques were developed and refined to identify resistance to Ascochyta blight (AB), caused by Ascochyta rabiei (Pass.) Labr. in chickpea. A controlled environment plant growth room facility developed for AB evaluation at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, India was modified to evaluate chickpea genotypes for resistance to AB. Controlled environment screening techniques, such as a seedling screening technique using 10-day-old seedlings and cut-twig screening techniques using excised twigs (10–15cm long) were developed. Components of the screening techniques were optimized in the controlled environment-plant growth room. The controlled environment screening techniques were found to be rapid, reliable and reproducible and a positive correlation was found between the seedling and cut-twig screening techniques (r=0.94). The cut-twig screening technique was quicker than the seedling screening technique and is particularly useful in screening segregating breeding lines derived from wild Cicer spp. Results of the controlled environment screening techniques were compared with results of field screening trials carried out at Dhaulakuan and Ludhiana in India, where the pathogen is endemic. A significant positive correlation was found between results from the controlled environment and field screening techniques (r=0.88). Using these resistance screening techniques, 150 elite chickpea breeding lines were evaluated and 29 lines with high and stable resistance to AB were identified

    Haemorrhage-related maternal mortality in Bangladesh: levels, trends, time of death, and care-seeking practices based on nationally representative population-based surveys

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    Background Haemorrhage is a major cause of maternal deaths globally, most of which are preventable and predominantly happen in low and middle-income countries, including Bangladesh. We examine the current levels, trends, time of death, and care-seeking practices for haemorrhage-related maternal deaths in Bangladesh. Methods We conducted a secondary analysis with data from the nationally representative 2001, 2010, and 2016 Bangladesh Maternal Mortality Surveys (BMMS). The cause of death information was collected through verbal autopsy (VA) interviews using a country-adapted version of the standard World Health Organization VA questionnaire. Trained physicians reviewed the VA questionnaire and assigned the cause of death using the International Classification of Diseases (ICD) codes. Results Haemorrhage accounted for 31% (95% confidence interval (CI) = 24-38) of all maternal deaths in 2016 BMMS, which was 31% (95% CI = 25-41) in 2010 BMMS and 29% (95% CI = 23-36) in 2001 BMMS. The haemorrhage-specific mortality rate remained unchanged between 2010 BMMS (60 per 100 000 live births, uncertainty range (UR) = 37-82) and 2016 BMMS (53 per 100 000 live births, UR = 36-71). Around 70% of haemorrhage-related maternal deaths took place within 24 hours of delivery. Of those who died, 24% did not seek health care outside the home and 15% sought care from more than three places. Approximately two-thirds of the mothers who died due to haemorrhage gave birth at home. Conclusions Postpartum haemorrhage remains the primary cause of maternal mortality in Bangladesh. To reduce these preventable deaths, the Government of Bangladesh and stakeholders should take steps to ensure community awareness about care-seeking during delivery

    Arabidopsis leucine-rich repeat receptor–like kinase NILR1 is required for induction of innate immunity to parasitic nematodes

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    Plant-parasitic nematodes are destructive pests causing losses of billions of dollars annually. An effective plant defence against pathogens relies on the recognition of pathogen-associated molecular patterns (PAMPs) by surface-localised receptors leading to the activation of PAMP-triggered immunity (PTI). Extensive studies have been conducted to characterise the role of PTI in various models of plant-pathogen interactions. However, far less is known about the role of PTI in roots in general and in plant-nematode interactions in particular. Here we show that nematode-derived proteinaceous elicitor/s is/are capable of inducing PTI in Arabidopsis in a manner dependent on the common immune co-receptor BAK1. Consistent with the role played by BAK1, we identified a leucine-rich repeat receptor-like kinase, termed NILR1 that is specifically regulated upon infection by nematodes. We show that NILR1 is essential for PTI responses initiated by nematodes and nilr1 loss-of-function mutants are hypersusceptible to a broad category of nematodes. To our knowledge, NILR1 is the first example of an immune receptor that is involved in induction of basal immunity (PTI) in plants or in animals in response to nematodes. Manipulation of NILR1 will provide new options for nematode control in crop plants in future

    Breeding Chickpea for Early Phenology: Perspectives, Progress and Prospects

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    Chickpea (Cicer arietinum L.) is currently grown in over 50 countries representing a wide range of environments and cropping systems. Phenology (time to flowering, podding and maturity) is an important component of crop adaptation in these environments. Crop maturity ranges from 80 to 180 days depending on genotype, soil moisture, time of sowing, latitude and altitude. However, in at least two-thirds of the chickpea growing area, the available crop-growing season is short (90-120 days) due to risk of drought or temperature extremities at the end of season (pod filling stage of the crop). About 73% of the global chickpea area is in South and Southeast Asia where chickpea is largely grown rainfed in the post-rainy season on receding soil moisture and often experiences terminal drought and heat stresses. Early phenology is also important in autumn-sown rainfed crop in Mediterranean-type environments for escape from terminal drought, as in Australia; and in summer-grown crop in the temperate environments for escape from frost at the end of season, as in Canada. Early phenology is also needed for promotion of chickpea to rice-fallows and other late sown conditions of south Asia. Hence, development of early maturing cultivars is one of the major objectives in chickpea breeding programs of International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, India and in several countries, including India, Myanmar, Bangladesh, Ethiopia, Australia and Canada. Several short-duration cultivars with resistance to fusarium wilt have been developed which have made significant impacts on enhancing chickpea area and production in central and southern India, Myanmar and Ethiopia. Efforts are being made to combine earliness with resistance to ascochyta blight and chilling tolerance for enhancing adaptation of chickpea to short-season Mediterranean regions and temperate environments. Early and extra-early cultivars are expected to play key role in expanding chickpea area in new niches where available crop growing season is short
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