1,245 research outputs found

    Quantum Logic Processor: A Mach Zehnder Interferometer based Approach

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    Quantum Logic Processors can be implemented with Mach Zehnder Interferometer(MZI) configurations for the Quantum logic operations and gates. In this paper, its implementation for both optical and electronic system has been presented. The correspondence between Jones matrices for photon polarizations and Pauli spin matrices for electrons gives a representation of all the unitary matrices for the quantum gate operations. A novel quantum computation system based on a Electronic Mach Zehnder Interferometer(MZI) has also been proposed. It uses the electron spin as the primary qubit. Rashba effect is used to create Unitary transforms on spin qubits. A mesoscopic Stern Gerlach apparatus can be used for both spin injection and detection. An intertwined nanowire design is used for the MZI. The system can implement all single and double qubit gates. It can easily be coupled to form an array. Thus the Quantum Logic Processor (QLP) can be built using the system as its prototype.Comment: 19 pages, 6 figures, 8 Table

    Impact of climate change on the characteristics of Indian summer monsoon onset

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    A high resolution regional climate modeling system, known as PRECIS (Providing REgional Climate for Impact Studies), developed by Hadley Centre for Climate Prediction and Research, UK, is applied for Indian subcontinent to assess the impact of climate change on the summer monsoon onset characteristics. The present day simulation (1961–1990) with PRECIS is evaluated for the characteristics of onset over Kerala, southernmost part of India, where the monsoon sets in over Indian landmass. The meteorological parameters like precipitation, outgoing long wave radiation (OLR), and low level winds are analysed to study the monsoon onset over Kerala. The model is able to capture the sudden and sharp increase of rainfall associated with the onset. The rapid built-up of convective activity over the southeastern Arabian Sea and Bay of Bengal is well represented by the model. PRECIS simulations, under scenarios of increasing greenhouse gas concentrations and sulphate aerosols, are analysed to study the likely changes in the onset characteristics in future, towards the end of present century (2071–2100). The analysis does not indicate significant difference in the mean onset dates in A2 and B2 scenarios. However, the variability of onset date is likely to be more towards the end of the 21st century especially in A2 scenario

    Impact of global warming on cyclonic disturbances over south Asian region

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    A state-of-the-art regional climate modelling system, known as PRECIS (Providing REgional Climates for Impacts Studies) developed by the Hadley Centre for Climate Prediction and Research, UK is applied over the Indian domain to investigate the impact of global warming on the cyclonic disturbances such as depressions and storms. The PRECIS simulations at 50 × 50 km horizontal resolution are made for two time slices, present (1961–1990) and the future (2071–2100), for two socioeconomic scenarios A2 and B2. The model simulations under the scenarios of increasing greenhouse gas concentrations and sulphate aerosols are analysed to study the likely changes in the frequency, intensity and the tracks of cyclonic disturbances forming over north Indian Ocean (Bay of Bengal and Arabian Sea) and the Indian landmass during monsoon season. The model overestimates the frequency of cyclonic disturbances over the Indian subcontinent in baseline simulations (1961–1990). The change is evaluated towards the end of present century (2071–2100) with respect to the baseline climate. The present study indicates that the storm tracks simulated by the model are southwards as compared to the observed tracks during the monsoon season, especially for the two main monsoon months, viz., July and August. The analysis suggests that the frequency of cyclonic disturbances forming over north Indian Ocean is likely to reduce by 9% towards the end of the present century in response to the global warming. However, the intensity of cyclonic disturbances is likely to increase by about 11% compared to the present

    Impact of global warming on cyclonic disturbances over south Asian region

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    A state-of-the-art regional climate modelling system, known as PRECIS (Providing REgional Climates for Impacts Studies) developed by the Hadley Centre for Climate Prediction and Research, UK is applied over the Indian domain to investigate the impact of global warming on the cyclonic disturbances such as depressions and storms. The PRECIS simulations at 50 x 50 km horizontal resolution are made for two time slices, present (1961-1990) and the future (2071-2100), for two socioeconomic scenarios A2 and B2. The model simulations under the scenarios of increasing greenhouse gas concentrations and sulphate aerosols are analysed to study the likely changes in the frequency, intensity and the tracks of cyclonic disturbances forming over north Indian Ocean (Bay of Bengal and Arabian Sea) and the Indian landmass during monsoon season. The model overestimates the frequency of cyclonic disturbances over the Indian subcontinent in baseline simulations (1961-1990). The change is evaluated towards the end of present century (2071-2100) with respect to the baseline climate. The present study indicates that the storm tracks simulated by the model are southwards as compared to the observed tracks during the monsoon season, especially for the two main monsoon months, viz., July and August. The analysis suggests that the frequency of cyclonic disturbances forming over north Indian Ocean is likely to reduce by 9% towards the end of the present century in response to the global warming. However, the intensity of cyclonic disturbances is likely to increase by about 11% compared to the present

    Characteristic Features of Precipitation Extremes over India in the Warming Scenarios

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    The detection of possible changes in extreme climate events, in terms of the frequency, intensity as well as duration assumes profound importance on the local, regional, and national scales, due to the associated critical socioeconomic consequences. Therefore, an attempt is made in this paper to evaluate various aspects of future projections of precipitation extremes over India, as projected by a state-of-art regional climate modeling system, known as PRECIS (Providing REgional Climates for Impacts Studies) towards the end of the 21st century (that is, 2071–2100) using standardized indices. Study reveals that PRECIS simulations under scenarios of increasing greenhouse gas concentration and sulphate aerosols indicate marked increase in precipitation towards the end of the 21st century and is expected to increase throughout the year. However the changes in daily precipitation and the precipitation extremes during summer monsoon (June through September) season are prominent than during the rest of year. PRECIS simulations under both A2 and B2 scenarios indicate increase in frequency of heavy precipitation events and also enhancement in their intensity towards the end of the 21st century. Both A2 and B2 scenarios show similar patterns of projected changes in the precipitation extremes towards the end of the 21st century. However, the magnitudes of changes in B2 scenario are on the lower side

    Modelling the Encroachment of Farmhouse Culture on Private Village Pastures and Its Environmental Fall-Out in Northern Western Ghats, India

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    Tropical India harbours numerous pasturelands across small landholdings ranging up to few hectares which are covered with grass that is suitable as fodder. These grazing lands are commonly known as ‘Gairan’ in urbanised northern Western Ghats mountain tract in Western India). Such grasslands comprise about 20% of the total area of a village (Jodha, 1986), support livestock and supplement the agro-economy of the village. These pasturelands are being replaced by fenced ‘farmhouses’ of the urban elite, resulting in land use changes that caused drastic qualitative and quantitative changes in terms of area, fodder species composition and livestock they support (Patwardhan et al., 2003). The study area has faced large changes in the last few decades with increases in the area under settlement by 240%s as well as a decrease in the area of agriculture land and grasslands-scrub vegetation by 31 % and 39 % respectively (Nalavade, 2003). The present paper documents socio-cultural, economic and environmental changes in private village pastures across the Mumbai-Pune urban belt

    Simulated projections for summer monsoon climate over India by a high-resolution regional climate model (PRECIS)

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    Impact of global warming on the Indian monsoon climate is examined using Hadley Centre's highresolution regional climate model, PRECIS (Providing REgional Climates for Impact Studies). Three simulations from a 17-member Perturbed Physics Ensemble generated using Hadley Center Coupled Model (HadCM3) for the Quantifying Uncertainty in Model Predictions (QUMP) project, are used to drive PRECIS. The PRECIS simulations corresponding to the IPCCSRES A1B emission scenario are carried out for a continuous period of 1961-2098. The model shows reasonable skill in simulating the monsoon climate over India. The climate projections are examined over three time slices, viz. short (2020s, i.e. 2011-2040), medium (2050s, i.e. 2041-2070) and long (2080s, i.e. 2071-2098). The model projections indicate significant warming over India towards the end of the 21st century. The summer monsoon precipitation over India is expected to be 9-16 more in 2080s compared to the baseline (1970s, i.e. 1961-1990) under global warming conditions. Also, the rainy days are projected to be less frequent and more intense over central India

    RAPD Analysis for Determination of Components in Herbal Medicine

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    In this study, the RAPD (Random Amplified Polymorphic DNA) technique was employed for determination of the components in an Ayurvedic herbal prescription, Rasayana Churna. One-hundred-and-twenty decamer oligonucleotide primers were screened in the RAPD analysis to identify three Ayurvedic medicines, dried stem of Tinospora cordifolia, dried fruit of Emblica officinalis and dried fruit of Tribulus terestris, the Ayurvedic prescription. Primer OPC-6 simultaneously generated three distinct amplicons, each specific to one component. The marker with 600 bp is specific to Tinospora cordifolia; the marker 500 bp is specific to Emblica officinalis and the remaining marker >1000 bp was present in Tribulus terestris. Presence of three herbal medicines was determined when RAPD reaction with OPC-6 was performed. The technique was proved to contribute to the identification of components in Ayurvedic herbal preparation and thus helping to serve as a complementary tool for quality control
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