Search

Very Low Frequency emissions are the audio-frequency signals generated by the wave particle interaction in the magnetosphere. These waves propagate in the whistler mode from the source region to the observation point. Accurate analysis and interpretation of the dynamic spectra yield information about composition and structure of the intervening media alongwith the generation mechanism. We have observed hiss, periodic hiss, chorus emission and triggered emissions during routine recording of whistler waves but spectrogram of the discrete VLF emissions are not presented in this paper. Details of theoretical computation are presented. In our computation we have shown that the non-linear theory of wave-particle interaction could explain partly the observed spectra. We have computed resonant electron energy for different pitch angle for L = 2 and 4.5 and Bunching time, trapping time, etc are also computed. The computed results are in good agreement with those reported by other workers. [ABSTRACT FROM AUTHOR]

This paper investigates the particle size distribution, chemical composition, fired modulus of rupture (MOR), and apparent porosity of blended clay utilizing clays available in Bikaner region and comparison with a imported Ukrainian clay. The blended clay B2 presents good white buff fired colour, higher fired modulus of rupture, and low porosity. The blend is suitable for Traditional Indian ceramic industries and a substitute of Ukrainian clay in India. [ABSTRACT FROM AUTHOR]

Coal is one of the most abundant energy resources and has the capability to meet future energy needs with high reliability. The use of coal as an energy source and as a source of organic chemicals feedstock may become more important in the future. It is physically and chemically a heterogeneous and carbonaceous rock which consists of organic and inorganic materials. Assam coal has been, and continuous to be, a valuable energy source, especially for the various industry in India and for liquefactions of coal. The basic chemical structure of coal that has been widely accepted today was built up from the synthesis of results obtained from X-ray diffraction data. The present paper reports a comparative investigation of coals from different collieries/areas of Makum coalfield, Assam viz. Ledo, Tikak, Baragolai, Tipong and Tirap collieries Makum coalfield, Assam with the help of X-ray diffraction (XRD). The X-ray diffraction patterns indicate that the coals are amorphous in nature. The present XRD method includes the evaluation of Function of Radial Distribution of Atoms (FRDA) and structural interpretations of the coals from their Radial Distribution Function (RDF) plots after proper corrections for air scatter, absorption by sample and polarization. The curve intensity profiles in FRDA clearly show quite regular molecular packets for these coals. The first maxima in the FRDA curves was obtained at r = 0.4 A° for Ledo, Baragolai and Tipong coals whereas for Tikak coal it was observed at r = 0.5 A°. The first maximum in the pair distribution function plots, G (r) of Ledo, Tikak, and Tipong coals was obtained at r = 0.15 nm whereas for Baragolai and Tirap coals it was observed at r = 0.14 nm and r = 0.12 nm respectively, which relates to the C-C (aliphatic/aromatic) bonds in coal matrix. The Assam coal samples from Ledo, Tikak, Baragolai, Tipong and Tirap collieries of Makum coalfield have almost the same RDF inter-atomic distances except slight differences. This study reveals the absence of graphite like structures in Assam (India) coals. [ABSTRACT FROM AUTHOR]

This paper gives an Introduction to Superconducting Magnetic Energy Storage (SMES) systems and their applications along with an overview of their present status. Further a brief description to a Micro SMES/UPS system of 0.5 MJ capacity that was developed/tested at IIT, Kharagpur is also included. [ABSTRACT FROM AUTHOR]

The National AIDS Control Organization (NACO) of India had estimated, before this year, that there were 5.134 million HIV positive people in India at the end of 2004 and that they were increasing at the rate of more than a quarter of a million people every year. In a recent publication, we estimated that, if the number of reported AIDS cases in India are only 50% efficient, i.e. if the number of actual AIDS cases in India is no more than twice the reported number, then the number of HIV positive people in India should have been no more than 2.5 million at the end of 2004. Many other people in the epidemiology community have the same point of view. Now, the government of India is also of the same view and “The latest data released by the government shows that the country has around 2 to 3 million people with HIV, much lower than last year's figure of 5.7 million”. However, our assumption that the actual number of AIDS cases in India is only about twice the number reported, has been questioned, and it has been suggested that the Indian system of AIDS reporting is woefully inaccurate and the actual number of AIDS cases there could be three, four or even five times the reported number. In this paper, we consider this suggestion and show that, even if the actual number of AIDS cases was three, four, or even five, times the reported number, the number of HIV positive people in India, at the end of 2004, should still be no more than 2.5 million. This is because our previous estimate was an over estimate and had room to accommodate considerably more number of AIDS cases. We also estimate the number of AIDS deaths in India and show that it should be considerably less than those estimated by the World Health Organisation (WHO). [ABSTRACT FROM AUTHOR]

The population growth in India may overtake China by the year 2030. The National Population Policy of India targets population stabilization in India by the year 2045. The present paper carries out objective analysis of the population growth in India in terms of change in specific growth. At the present rate of specific growth rate decline, the population by the end of the century will be 2.49 billion. For the population to achieve zero growth by the year 2045, a decline in specific growth rate will have to be achieved at the rate of 0.000428 per year. [ABSTRACT FROM AUTHOR]

Energy is supplied in the form of electricity, heat or fuels and an energy supply system must guarantee sufficient production and distribution of energy. An energy supply system based on renewable energy can be utilized as integrated renewable energy system (IRES), which can satisfy the energy needs of an area in appropriate & sustainable manner. Given the key role of renewable energy in rural electrification of remote rural areas, the IRES for a given area can be modeled & optimized for meeting the energy needs. In the present paper, Jaunpur block of Uttaranchal state of India has been selected as remote area. Based upon the data collected, the resource potential and energy demand has been calculated & presented. The model on the basis of unit cost of the energy has been optimized using LINDO software 6.10 version. The results indicated that the optimized model has been found to the best choice for meeting the energy needs of the area. The results further indicated that for the above area, either an IRES consisting of the above sources can provide a feasible solution in terms of energy fulfillments in the range of EPDF from 1.0 to 0.75. [ABSTRACT FROM AUTHOR]

Statistical analysis of historical rainfall, involving fitting of an appropriate distribution for obtaining rainfall intensities of different interval, is very much useful for making resource allocation decisions concerning risks. This paper gives details of a study involving the use of six statistical distributions for rainfall estimation for Barh and Megharaj sites. Anderson Darling test statistic was used for checking the goodness of fit of the distributions to the recorded data. Diagnostic analysis, involving D-index statistic, was used for evaluating the suitability of the probability distribution for the data under study. The study shows the Log Pearson Type III to be the best suited, among six statistical distributions studied, for extreme value analysis of the rainfall for the data under study. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

Rain attenuation studies especially in tropical countries assume significance due to sparse measurements and variability in rain rates and drop size distributions. Conventional techniques are not very significant in dealing with the attenuation due to melting layer and vertical structure of rainfall. The MST radar located at Gadanki, India, is an excellent state of the art system for atmospheric studies. Earlier studies have demonstrated that VHF radars like MST can also be used for precipitation studies. The VHF Radar operating at 53 MHz with a peak power of 2.5 MW is able to provide details of melting layer and drop fall velocities. However, identification of precipitation echo from the clear echo is quite challenging, as 53 MHz is not attenuated by rain. Nevertheless studies have clearly demonstrated in identifying the two echoes. Present Paper deals with new algorithms based on the wavelet analysis techniques (time series data (I & Q)) to deal with the problem. The technique has been used for SNR improvement, and effective tracing of the Doppler profile even in low SNR regions. This is a definite advantage over the conventional algorithms based on single peak detection which usually fail in extracting the Doppler profile in the low SNR regions. Also, the conventional algorithms fail to trace the clear air echo during convection. The proposed algorithm has been tested on both the clear air and convection data sets. The results thus obtained have been compared with existing algorithms. Consistency of Doppler profile and better height coverage has been reported. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

The sunrise effect, sunset effect, the diurnal and seasonal variations are the characteristic feature of low frequency (LF) radio wave propagated over a large distance. The normal character has been found to be perturbed during rainy days. The amplitude of 40 kHz signal transmitted from Miyakoji station, Japan and received in North-East India is remarkably attenuated after the commencement of rain. On the basis of nature of attenuation the observed records have been classified into two different forms viz., F1 and F2. An analysis in this regard is represented in this paper. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

The efficient design of reliable communication link requires the knowledge of rain fade margin to be provided in the system design to overcome the losses in the signal strength due to rain over the path. Hence there is need for the development of reliable and accurate propagation model for attenuation prediction at the operating frequency of the link at particular location. Therefore study of rain-induced effects on microwave propagation was undertaken at Guru Nanak Dev University, Amritsar. This paper describes the measurement of zenith path attenuation due to rain at Amritsar (31° 38′ N 74° 52′ E) India, using zenith looking radiometer operating at 20 GHz. The effective rain height has been obtained from the analysis of the radiometric data and point rainfall intensity. Specific attenuation for various rain rates in the present study has been evaluated from measured drop size data using lognormal drop size distribution. The average effective rain height at Amritsar has been estimated and compared to that of predicted by ITU-R model. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

Developments of new reactor designs for the utilization of thorium, such as the Advanced Heavy Water Reactor, especially demand creation of new nuclear data for all the isotopes of the thorium fuel cycle. Improved nuclear data are essential to support new initiatives such as the international project on innovative nuclear reactors and fuel cycles (INPRO), which aims to support the safe, sustainable, economic, and proliferation-resistant use of nuclear technology to meet the global energy needs of the 21st century. The detailed pursuit of development of Generation IV nuclear energy systems that offer advantages in the areas of economics, safety, reliability, and sustainability require significantly improved nuclear data. The development of Accelerator Driven Sub-critical Systems proposed by Carlo Rubbia and others require a significant amount of new nuclear data in extended energy regions and improvement of the presently available nuclear data. The quality assurance in design and safety studies in nuclear energy in the next few decades and centuries require new and improved nuclear data with high accuracy and energy resolution. The paper presents, from the perspective of the author, an overview of some of the improvements in nuclear data required for a sound scientific basis of advanced nuclear systems. Also, from the perspective of benchmarking and integral validation of nuclear data, presented briefly is the status of thorium irradiations performed in a Pressurized Heavy Water Reactor (PHWR) in India and new results of post-irradiation analyses available thus far. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Networking plays an important role in ensuring that women participate equally in science and technology. In Nagpur, India, a growing city in the center of the country, a small and local network called Women in Physics in Nagpur was launched in July 2013 with about 10-15 members. A Google group of the same name was also launched. The main aim of the network was to set collective goals towards a vision for Indian women physicists. This paper reports on one of our early activities, a survey of women in Nagpur who have a physics background, and suggests future activities. [ABSTRACT FROM AUTHOR]

Cryogenic bolometer detectors, with their high resolution spectroscopy capability, are ideal for neutrino mass experiments as well as for search of rare processes like neutrinoless double beta decay (0νββ) and dark matter. A feasibility study for investigation of 0νββ in 124Sn at the upcoming underground facility of India based Neutrino Observatory (INO) has been initiated. This paper describes endeavors towards cryogenic tin bolometer development. [ABSTRACT FROM AUTHOR]

This paper presents a Linear Programming (LP) model for obtaining optimized cropping area in the command of Ukai reservoir. The objective is to maximize the sum of the relative yields from all crops in the irrigated area for specific range of water availability like 100%, 90%, 80% and 70%. The present study is aimed to get the optimal allocation of irrigation water depending upon the availability of water from the source. The net revenue from agricultural production will be maximized for available irrigation water taking into account the sets of constraints like crop area, cropping pattern and water requirement. The model is applied to a part of Ukai reservoir system namely Ukai Right Bank Main Canal (URBMC), in Gujarat state, India. [ABSTRACT FROM AUTHOR]

MoRT&H claims that a total of 10,855 kms of national highways was constructed in FY 2018-2019, highest ever in a single year and projects combining to 52,000 kms are in progress in the current year. CRISIL forecasts that NHAI will be awarding tenders of 4,000-4,300 kms per year between the fiscal years 2020-2024. So, it can be established that road and highway development in India is happening faster than ever before. All this development will lead to greater demand in materials and having alternate recycled materials can be a solution to fulfill those demands quickly, efficiently and cost economically. This research focusses on studying potential alternative materials for flexible pavements by analyzing the existing research of the past 10 years and establish a list of potential materials which can be used as an alternative. On studying several alternate materials had good potential, ranging from waste plastic, waste foundry sand, copper slag, etc. to materials like waste cooking oil. The most popular of those were, waste plastic, waste rubber, reclaimed asphalt and copper slag. Further analysis included to verify with any kind of specification, specified for use of such materials and have a conclusion on how these materials can be adopted as pavement materials. [ABSTRACT FROM AUTHOR]

Rajasthan is mineral based state and Bikaner and its surrounding district have been gifted with Gypsum. Mt of Gypsum is available in these districts. Gypsum has multiple uses including basic raw material for POP industry, addition in cement and a natural fertilizer. This mineral has changes the economic scenario in the remote areas of Bikaner, Nagaur, Hanumangarh, Sanchore, Shriganganagar etc. Gypsum and selenite are mined about 3.0 million tons per year. There is huge demand from cement industry as Gypsum is added for improving setting time of cement. Gypsum is a natural fertilizer for alkaline land and it role is vital in state like India where alkaline land is major role. Its high use as fertilizer has potential to change millions of poor farmer families and improving in crop production. Cement Industry has started importing Gypsum from Thailand, Bankong, Pakistan, Iran etc. The mining of gypsum of purity of 70% CaSO4.2H2O is cooperative effort between the land owners and Rajasthan State Mines and Minerals Limited. Gypsum fulfills the demand of POP and Cement industry in Rajasthan and powder gypsum used in agriculture for recon dining of alkaline soil. This paper deals with multiple uses, availability, and future prospective of Gypsum, a white gold of Rajasthan. [ABSTRACT FROM AUTHOR]

In the present paper we accumulate the recent advances in atmospheric research by analyzing meteorological data. We have calculated meteorological parameters over the central Himalayan region at Nainital (longitude 79.45□ E, latitude 29.35□N). It is a high altitude place (1951 meters) which is very useful for such type of measurement. We have done our work on meteorological parameters in GVAX (Ganges Valley Aerosol Experiment) project. It was an American-Indo project which was use to capture pre-monsoon to post-monsoon conditions to establish a comprehensive baseline for advancements in the study of the effects of Atmospheric conditions of the Ganges Valley. The Balloon Borne Sounding System (BBSS) technique was also used for in-situ measurements of meteorological parameters. [ABSTRACT FROM AUTHOR]

Building materials cause direct radiation exposure because of their radium, thorium and potassium content. In this paper, samples of commonly used building materials in Tiruvannamalai, city, have been collected randomly over the city. The samples were tested for their radioactivity contents by using gamma spectroscopic measurements. All samples under investigation are within the recommended safety limit when used as building construction. [ABSTRACT FROM AUTHOR]

In this paper we summarize the situation for women in physics in India. We provide some statistics, describe new initiatives, and provide comments collated from the widely varying backgrounds of the authors. [ABSTRACT FROM AUTHOR]

In present days radio communication scenario, three issues are considered to be the most important. These are reliability, directivity and regulation of transmitted power. All such issues can be taken care provided the characterization of our tropospheric medium is done with good degree accuracy. The radio wave propagating above 10 GHz is affected severely by rain and cloud. In case of rain, the attenuation of radio wave is the main concerned but for cloud along with attenuation, noise temperature generated by cloud is also another issue. Cloud attenuation and cloud noise temperature can be deduced if cloud morphology in terms of cloud coverage, cloud height, cloud thickness, cloud liquid water content etc. is available. The meteorologists of India have studied cloud morphology as well as cloud dynamics for the weather forecasting purposes. But in this paper, an attempt has been made to deduce results on cloud parameters for radio wave propagation studies by utilizing the observations taken by the sophisticated computer controlled Doppler radar belonging to the India Meteorological Department over Kolkata. The Doppler radar operates in C-band at frequency ∼ 2700–2900 MHz with peak power 500 kW. Several cloud parameters viz. radar reflectivity, cloud thickness, cloud height, cloud vertical integrated liquid water content etc. have been studied in probability distribution scale. Based on cloud height, the temperature of the cloud has been determined. It is seen that over Kolkata, the cloud height ∼ 6.5 km occur for maximum percentage of time. The cloud temp has been estimated by using the lapse rate of the temperature with height, which is ∼ 6.5°c km. By using the cloud height, cloud temperature and cloud liquid water content, the attenuation of radio wave due to cloud at microwave and millimeter wave frequency bands, over Kolkata have been derived. It is seen that attenuation value varies from 0.2 dB / km to 30 dB / km over the frequency range from 10 GHz to 100 GHz. The noise temperature generated by cloud has been estimated and found to be from 8°K to 202°K at the frequency range from 10 GHz to 70 GHz with cloud thickness ∼ 1 km and at cloud temperature ∼ 260 °K. Such noise affects the signal to noise (S/N) ratio of the communication system. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]