728 research outputs found
Role of deities in symbolizing conflicts of dispersing human groups
This article does not have an abstract
Ecology is for the people
The paper provides a theoretical frame work of evolution of ecological prudence in human populations. It emphasizes the urgent need to understand the conditions that favour or militate against the exercise of ecological prudence. Evidence is presented to show that the Indian society had evolved a rich tradition of social restraints on resource utilization. It is suggested that ecological prudence could come to prevail in India only through the involvement of the people at the grass-roots level
Particulate emissions from a wood-fired improved biomass stove
Worldwide, approximately three billion people cook their food using biomass fuels such as wood, charcoal, crop residues, and animal dung. The emissions produced by these smoky fires lead to four million premature deaths annually and large environmental consequences. While the negative effects of biomass burning have spurred much research into designing less polluting cookstoves, researchers need a knowledge-base to draw from when making design decisions. However, previous research has measured these emissions relatively far away from the source, not exploring how the design modifications affect the actual combustion. In this study, the emissions from an improved cookstove, the Berkeley-Darfur Stove, and single blocks of wood are examined in-situ using laser extinction. The pollutant production, measured by the opacity or soot volume fraction, was compared between the two systems to gain a deeper understanding of combustion in the stove while providing initial steps towards a non-intrusive sampling system for pollutant production in cookstove combustion chambers.Kathleen M. Lask, Paul R. Medwell, Cristian H. Birzer, Ashok J. Gadgilhttp://cfe.uwa.edu.au/news/acs2013http://www.anz-combustioninstitute.org
Multilayered feed forward Artificial Neural Network model to predict the average summer-monsoon rainfall in India
In the present research, possibility of predicting average summer-monsoon
rainfall over India has been analyzed through Artificial Neural Network models.
In formulating the Artificial Neural Network based predictive model, three
layered networks have been constructed with sigmoid non-linearity. The models
under study are different in the number of hidden neurons. After a thorough
training and test procedure, neural net with three nodes in the hidden layer is
found to be the best predictive model.Comment: 19 pages, 1 table, 3 figure
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Field-testing UV disinfection of drinking water
A recently invented device, ``UV Waterworks,`` uses ultraviolet (UV) light to disinfect drinking water. Its novel features are: low cost, robust design, rapid disinfection, low electricity use, low maintenance, high flow rate and ability to work with unpressurized water sources. The device could service a community of 1,000 persons, at an annual total cost of less than 10 US cents per person. UV Waterworks has been successfully tested in the laboratory. Limited field trials of an early version of the device were conducted in India in 1994--95. Insights from these trials led to the present design. Extended field trials of UV Waterworks, initiated in South Africa in February 1997, will be coordinated by the South African Center for Essential Community Services (SACECS), with technical and organizational support from Lawrence Berkeley National Laboratory(LBNL) and the Natural Resources Defense Council (both US). The first of the eight planned sites of the year long trial is an AIDS hospice near Durban. Durban metro Water and LBNL lab-tested a UV Waterworks unit prior to installing it at the hospice in August, 1997. The authors describe the field test plans and preliminary results from Durban
Mapping ecologically sensitive, significant and salient areas of Western Ghats: proposed protocols and methodology
The Western Ghats Ecology Expert Panel (WGEEP) of the Ministry of Environment and Forests, Government of India (GOI) has been asked to identify ecologically sensitive areas (ESAs) along the Western Ghats, and to suggest how to manage them. The concept of ESAs has been extensively discussed in the literature. Several ESAs have been set up in India over the last 22 years under the Environment Protection Act, 1986, and a GOI committee under the chairmanship of Pranob Sen has proposed certain criteria for identification of
ESAs. However, WGEEP noted that we still lack a global consensus either on the criteria to define ESAs or on a workable methodology to identify them. Furthermore, there are no clear guidelines on the management regime that should prevail in ESAs, and the Pranob Sen Committee has not addressed this issue at all. Hence, WGEEP
decided to undertake an exercise of defining ESAs and developing a workable methodology to assign levels of ecological significance/sensitivity as a first step towards putting ESAs on the map of the Western Ghats. This article provides a report on the outcome of a series of discussions and consultations held by WGEEP to
build a consensus on defining and mapping ESAs. It hopes to provoke discussion and feedback from a wider section of experts, with the aim of finalizing a generic methodology for mapping ESAs in other ecologically sign
ificant, biodiversity-rich areas within and outside the country. We hope to shortly prepare a companion paper that will address the equally vital management issues
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Influence of Subslab Aggregate Permeability of SSV Performance
The effectiveness of the technique of subslab ventilation (SSV) for limiting radon entry into basements was investigated through complementary experimentation and numerical modeling. Determination of the impact of subslab aggregate permeability on SSV performance was a primary objective. Subslab pressure fields resulting from SSV were measured in six well-characterized basements, each with a different combination of soil and aggregate permeability. The relationship between air velocity and pressure gradient within the three types of aggregate installed beneath the basement slabs was measured in the laboratory. A new numerical model of SSV was developed and verified with the field data. This model simulates non-Darcy flow in the aggregate. We demonstrate that non-Darcy effects significantly impact SSV performance. Field data and numerical simulations indicate that increasing the aggregate permeability within the investigated range of 2 x 10{sup -8} m{sup 2} to 3 x 10{sup -7} m{sup 2} substantially improves the extension of the subslab pressure field due to SSV operation. Subslab pressure field extension also improves as soil permeability decreases between 10{sup -9} m{sup 2} and 10{sup -10} m{sup 2}. With a slab-wall gap thickness of 1 mm and the range of aggregate permeability investigated, further reductions in soil permeability do not significantly improve the subslab pressure field extension. Sealing of cracks in the slab and excavation of a small pit where the SSV pipe penetrates the slab also dramatically improve this pressure field extension. A large ratio of aggregate permeability to soil permeability reduces the need for large depressurizations at the SSV pit. Our findings are consistent with the results of prior field studies; however, our understanding of SSV is improved and the dependence of SSV performance on the relevant parameters can now be quantified with the model
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Impacts of a Sub-Slab Aggregate Layer and a Sub-Aggregate Membrane on Radon Entry Rate: A Numerical Study
A subslab aggregate layer can increase the radon entry rate into a building by up to a factor of 5. We use a previously tested numerical technique to investigate and confirm this phenomenon. Then we demonstrate that a sub-aggregate membrane has the potential to significantly reduce the increase in radon entry rate due to the aggregate layer, even when a gap exists between the perimeter of the membrane and the footer. Such membranes greatly reduce diffusion of radon from the soil into the aggregate and are impermeable to flow. Radon entry through the basement floor slab is limited to radon entry through the holes in the membrane. In addition, a sub-aggregate membrane is predicted to improve the performance of active sub-slab ventilation systems and makes passive systems more promising
Chapter 9 - Buildings
This chapter aims to update the knowledge on the building sector since the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) from a mitigation perspective. Buildings and activities in buildings are responsible for a significant share of GHG emissions, but they are also the key to mitigation strategies. In 2010, the building sector accounted for approximately 117 Exajoules (EJ) or 32% of global final energy consumption and 19% of energy-related CO2 emissions; and 51% of global electricity consumption. Buildings contribute to a significant amount of F-gas emissions, with large differences in reported figures due to differing accounting conventions, ranging from around an eighth to a third of all such emissions. The chapter argues that beyond a large emission role, mitigation opportunities in this sector are also significant, often very cost-effective, and are in many times associated with significant co-benefits that can exceed the direct benefits by orders of magnitude. The sector has significant mitigation potentials at low or even negative costs. Nevertheless, without strong actions emissions are likely to grow considerably - and they may even double by mid-century - due to several drivers. The chapter points out that certain policies have proven to be very effective and several new ones are emerging. As a result, building energy use trends have been reversed to stagnation or even reduction in some jurisdictions in recent years, despite the increases in affluence and population.
The chapter uses a novel conceptual framework, in line with the general analytical framework of the contribution of Working Group III (WGIII) to the IPCC Fifth Assessment Report (AR5), which focuses on identities as an organizing principle
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