Management and Performance of APPLE Battery in High Temperature Environment

India's first experimental communication satellite, APPLE, carried a 12 AH Ni-Cd battery for supplying power during eclipse. Failure to deploy one of the two solar panels resulted in the battery operating in a high temperature environment, around 40 C. This also resulted in the battery being used in diurnal cycles rather than just half yearly eclipse seasons. The management and performance of the battery during its life of two years are described. An attempt to identify the probable degradation mechanisms is also made

Study of dominating parameters of high speed solar plasma streams in relation to cosmic ray and geomagnetic storms

The high speed solar wind streams observed near Earth are generally associated with the solar features, such as solar flares and coronal holes. Past studies of these streams from the two sources have revealed distinctly different effects on cosmic ray intensity, whereas the effect is similar for geomagnetic disturbances. Moreover, the effect of the magnitude of the high speed streams (V) and its rate of increase (dv/dt) has also been a subject of investigation to understand their relative contribution in producing geomagnetic disturbances. From the analysis of some of the fast streams presented here, it is difficult to predict, which one of the two (V, dv/dt) is more effective in producing geo-magnetic disturbances. Further, in most of the cases, no substantial decrease in cosmic ray intensity is observed

The refractive index and wave vector in passive or active media

Materials that exhibit loss or gain have a complex valued refractive index $n$. Nevertheless, when considering the propagation of optical pulses, using a complex $n$ is generally inconvenient -- hence the standard choice of real-valued refractive index, i.e. n_s = \RealPart (\sqrt{n^2}). However, an analysis of pulse propagation based on the second order wave equation shows that use of $n_s$ results in a wave vector \emph{different} to that actually exhibited by the propagating pulse. In contrast, an alternative definition n_c = \sqrt{\RealPart (n^2)}, always correctly provides the wave vector of the pulse. Although for small loss the difference between the two is negligible, in other cases it is significant; it follows that phase and group velocities are also altered. This result has implications for the description of pulse propagation in near resonant situations, such as those typical of metamaterials with negative (or otherwise exotic) refractive indices.Comment: Phys. Rev. A, to appear (2009

GIS based modeling of socio-environmental impacts due to a highway development project- A case study

Infrastructure development is the basic need for economic development of a country. Highway is an important infrastructure for movement of goods and passenger traffic. In the recent years, the need for developing adequate road transportation infrastructure has been realized by Government of India and various state Governments.  Major road development projects have been formulated at national level in India. Analysis of socio-environmental impact is an essential component of environmental impact assessment (EIA) that is required for the planning of all major road projects. Most of the socio-environmental attributes are spatial in nature and for a rational assessment of these impacts it is necessary to quantify the impacts considering their spatial variations.In this paper a methodology is demonstrated with reference to a case study of highway development project in India, for the quantification of impact on individual socio-environmental attributes based on the perception of public in the influence area of the project, and the spatial variation of impacts is modeled using Geographic Information System (GIS). &nbsp

Water quality surrounding to MSW dumps of Raipur city-A case study

In India, urbanization and rapid population growth have led to degradation of environment, by increased rate of exploitation of natural resources and generation of municipal solid wastes (MSW). Municipal Solid Waste (MSW) disposal is a big problem for most of the towns in developing countries. In India dumping of MSW on low laying area is the common practice in most of the towns. The dumping of waste in uncontrolled manner creates many kinds of problems for the surrounding environment. Ground water pollution is one of the serious effects of the MSW dumping. The assessment of impacts on ground water sources near to MSW dumps is of considerable importance in management and disposal of solid waste. The leachate may greatly affect the ground water sources near to the dumpsites. In the present study an attempt has been made to investigate the extent of impact on ground water sources namely open wells, shallow tube wells (depth less than 30 m) and deep tube wells (depth more than 50 m).  The pollution status is also monitored at varying distances from the solid waste dumping sites to investigate the trend of leachate movement in the subsoil. Water samples from different sources at different locations are assessed for physical, chemical and biological properties.&nbsp

Seasonal variation in composition and characteristics of indian municipal solid waste –A case study

In developing countries like India, rapid urbanization and uncontrolled population growth have lead to the socio-environmental problem of ill-managed municipal solid waste. Evaluating the characteristics of municipal solid waste is an important aspect of MSWM because the selection of effective management strategies depends on the types and variation in the characteristics of the waste to be managed. The focus of the present paper is to determine the variation in composition as well as characteristics of municipal solid waste for Indian conditions. A case study is presented for Raipur city to determine the seasonal variation in waste characteristics. The seasonal variation in characteristics of MSW was found to be in a wide range of 4-125 %, so for comprehensive management of this MSW, a proper combination of recycling and recovery, composting, energy generation and dumping on land should be adopted.&nbsp

Cumulative effect of Forbush decreases in the heliospheric modulation during the present solar cycle

A monthly Forbush decrease index (Fd-I) is generated and it is compared with the observed long term chnges in the cosmic ray intensity near earth at energies greater than or equal to 1 Gev over 1976-83. Significant correlation is observed between the two except for 1978. Such an effect is also seen in the correlation plot between the solar flare index (SFI) and Fd-I

Energy-efficient Multifunctional Sensors based on Semiconductor Devices.

The growing potential of telemedicine and on-body health monitoring has led to the emergence of a new set of challenges associated with chemical, biological and other kinds of sensors that may be needed to facilitate integration with wearable devices. This thesis is aimed at addressing some of these challenges via the use of novel semiconductor device architectures in ways that facilitate significant advances in energy efficiency, miniaturization and cost effectiveness of traditional sensing techniques. For displays, organic light emitting devices (OLED) offer several unprecedented advantages over conventional displays, including flexibility, compactness, and superior power efficiency. However, the touch sensing capability in such devices is usually provided by capacitive or resistive sensors overlaid on the main display that increase bulkiness. Integration of touch sensing with the imaging plane of the display could dramatically reduce thickness, improve reliability, and enhance sensing resolution. This thesis reports a novel physical effect in OLEDs that could allow touch sensing to be performed by the image-forming pixel itself. In addition to studying the fundamental physical mechanism by which this sensing proceeds, an efficient single pixel OLED that generates changes in electrical current upon touch is discussed. Another new challenge in wearable electronics is limited on-board power, due to growing power requirements to support a larger number of functions, and a relatively low energy density of batteries. At the same time, a considerable amount of research in recent years has been dedicated to developing novel biochemical sensors that can be integrated with wearables. To address these two emerging challenges, a modified dye-sensitized solar cell is designed to detect common contaminants in drinking water (e.g. metal ions), while powering its own operation by converting absorbed ambient light into an electrical signal. Finally, a simple, cost-effective chemiluminescence detection scheme is that is applicable to a wide variety of substances, ranging from environmental contaminants to biomarkers, is demonstrated. We expect that further improvements in the optical collection efficiency of the reaction chamber will result in detection limits in the single nanomolar regime, potentially unlocking a broad range of field and point-of-care diagnostic applications.PhDMaterials Science and EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/113321/1/kanika_1.pd

Use of fly ash in black cotton soil for road construction

Waste products from various industries normally deposited in landfills, have been proposed for use as an alternate construction material. The utilization of these alternate materials needs to be encouraged for economy of construction and conservation of materials. One by-product that has shown as an alternate construction material is fly ash. In this paper an effort is made to use fly ash to stabilise soils for road construction, in order to reduce the amount of waste globally. In the present assignment, black cotton soils were stabilized with different quantities of fly ash. On the basis of preliminary investigations, it has been found that stabilization with fly ash, improves the CBR and plasticity characteristics of black cotton soils.For hydration of fly ash, the lime content is responsible, so substantial improvements in desired properties can be achieved by addition of small quantity of lime. ie2< r؇F `oF Microbiologists have come up with an important point that if genetic modification is carried out extensively, new viruses with greater potential to harm mankind may evolve anytime, and the probability of this occurring can be quite high. This form of dangerous biotechnology will only benefit largely towards the GM crop farmers in form of monetary gain. According to relevant statistics, farmers would save more than US$3.3 billion annually on herbicides, insecticides, and fungicides. So come to think of it. Is it worthwhile to become the guinea pigs just to save a few bucks, while those farmers are sitting down there counting their huge earnings without inflicting any risks on themselves? While some countries have banned GMOs or placed a moratorium on their release, others are increasing both investment levels and land area devoted to cultivating genetically modified (GM) crops. In 2006, GM crops were grown commercially by 10.3 million farmers (9.3 million resource-poor small farmers in developing countries) in 22 countries, on 102 million hectares - about 4 per cent of total arable land worldwide [5] &nbsp