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Search Results: 1 - 10 of 945 matches for " Arjun Patra "
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Isolation and characterization of stigmast-5-en-3β-ol (β-sitosterol) from the leaves of Hygrophila spinosa T. Anders
Arjun Patra,S. Jha,P.N. Murthy,,Manik
International Journal of Pharma Sciences and Research , 2010,
Abstract: Purpose: Hygrophila spinosa T. Anders (Acanthaceae) commonly known as ‘Talmakhana’ in Hindi contains a number of phytoconstituents viz. alkaloids, phytosterols, glycosides, amino acids, proteins, phenolic acids, enzymes, vitamins, sugars, minerals, flavonoids, gums & ucilage, terpenoids etc. The objective of the present study was to isolate and characterize phytoconstituents(s) from the chloroform extract of Hygrophila spinosa leaves. Methods: Chloroform extract was subjected to column chromatography and eluted with solvent mixtures of increasing polarity, composed of petroleum ether, benzene and chloroform to isolate phytoconstituents. The structure of the isolated compound was established on the basis of elemental analysis and spectroscopic evidences (IR, UV, 1HNMR, 13CNMR, MS). Results: A sterol, stigmast-5-en-3β-ol was isolated from the chloroform extract of the leaves of the plant. The yield of the compound was 0.0046% w/w, m.p. 136- 1380C, λmax in EtOH: 206 nm, Rf value 0.72 in Toluene: Ether: Cyclohexane (5:2:1). Conclusions: Hygrophila spinosa contains β-sitosterol which may be responsible for various pharmacological activities of the plant.
The Method of Finite Difference Regression  [PDF]
Arjun Banerjee
Open Journal of Statistics (OJS) , 2018, DOI: 10.4236/ojs.2018.81005
Abstract: In this paper I present a novel polynomial regression method called Finite Difference Regression for a uniformly sampled sequence of noisy data points that determines the order of the best fitting polynomial and provides estimates of its coefficients. Unlike classical least-squares polynomial regression methods in the case where the order of the best fitting polynomial is unknown and must be determined from the R2 value of the fit, I show how the t-test from statistics can be combined with the method of finite differences to yield a more sensitive and objective measure of the order of the best fitting polynomial. Furthermore, it is shown how these finite differences used in the determination of the order, can be reemployed to produce excellent estimates of the coefficients of the best fitting polynomial. I show that not only are these coefficients unbiased and consistent, but also that the asymptotic properties of the fit get better with increasing degrees of the fitting polynomial.
Avian Diversity in and around Digha, District—East Midnapore (West Bengal, India)  [PDF]
Goutam Patra, Santanu Chakrabarti
Advances in Bioscience and Biotechnology (ABB) , 2014, DOI: 10.4236/abb.2014.57070
Abstract:

The digha is located at the border of West Bengal and Orissa state. It has both fresh and saline waterbodies rich in aquatic vegetation and several kinds of birds in the harbours in all the seasons. Grassland areas, rice fields, herbs, shrubs and trees located in and around the water bodies provide food and shelter for these birds. Total number of 86 bird species belonging to 10 orders and 35 families were recorded during the 2-year long study period. Passeriformes is the dominant order of birds. But the future of this avian fauna is in danger due to unchecked growth of tourism related hotel industry and urbanisation of the city.

Formation of Neutron-Rich and Superheavy Elements in Astrophysical Objects  [PDF]
Rabinarayan Panda, Suresh Kumar Patra
Journal of Modern Physics (JMP) , 2010, DOI: 10.4236/jmp.2010.15044
Abstract: We calculate the reaction and the fusion cross-sections of neutron-rich heavy nuclei taking light exotic isotopes as projectiles. Results of neutron-rich Pb and U isotopes are demonstrated as the representative targets and He, B as the projectiles. The Gluaber Model and the Coupled Channel Formalism are used to evaluate the reaction and the fusion cross-sections for the cases considered. Based on the analysis of these cross-sections, we predict the formation of heavy, superheavy and super-superheavy elements through rapid neutron/ light nuclei capture r-process of the nucleosynthesis in astrophysical objects.
Influence of Hot Band Annealing and Cold Rolling on Texture and Ridging of 430 Stainless Steel Containing Aluminum  [PDF]
Sudipta Patra, Lokesh Kumar Singhal
Materials Sciences and Applications (MSA) , 2013, DOI: 10.4236/msa.2013.41009
Abstract:

An approach to optimize the processing parameters to get superior ridging resistance and mechanical properties in commercial production of 430 ferritic stainless steel has been studied. Attention was also paid to improve productivity and energy saving without hampering the surface and mechanical property aspects of the material. Hot rolled coils annealed by slow cooling under insulated cover exhibit better ridging resistance than bell annealing treatment with a minor decrease in ductility. Soaking temperature prior to hot rolling has a significant effect on ridging resistance.

Landslide Hazard Mapping of Nagadhunga-Naubise Section of the Tribhuvan Highway in Nepal with GIS Application  [PDF]
Arjun Raj Pandey, Farzad Shahbodaghlou
Journal of Geographic Information System (JGIS) , 2014, DOI: 10.4236/jgis.2014.66059
Abstract: The aim of this project was to prepare and study a hazard map of Nagadhunga-Naubise section of the Tribhuvan highway. This section lies in the Middle Mountain region of Nepal. For the preparation of the hazard map of the corridor three steps, initial study, field investigation, and data analysis and presentation were carried out. In the initial study, the collection of available data and review of the literature were done. The base map was then prepared from the topographical map. In the field investigation step, all information and maps prepared earlier in the initial study were verified by field check. In the final step, prepared and verified data were then analyzed for the hazard mapping. Topography (gradient, slope shape and slope aspect), geology, drainage and land-use were considered to be the major influencing factors in the slope stability. Pre-assigned hazard rating method was used for hazard mapping of the study area. The area was divided into equal facets. Then ratings of responsible factors to the hazard were assigned to each facet and overlaid based upon a predetermined rating scheme. Total estimated hazard was the sum of these ratings for each overlay. Hazard map was prepared by using three categories as low hazard, medium hazard and high hazard. The Geographic Information System (GIS) was the main tool for the data input, analysis, and preparing of the final hazard map. The hazard map showed the areas of different hazard potential classes of; “low” with 32% portion, “Medium” with 51%, and “high” with 17% portion.
Acoustic Emission based Tool Condition Monitoring System in Drilling
Karali Patra
Lecture Notes in Engineering and Computer Science , 2011,
Abstract:
Biomedical Image Processing with Morphology and Segmentation Methods for Medical Image Analysis
Joyjit Patra
American Journal of Engineering Research , 2013,
Abstract: Modern three-dimensional (3-D) medical imaging offers the potential and promise for major advances in science and medicine as higher fidelity images are produced.It has developed into one of the most important fields within scientific imaging due to the rapid and continuing progress in computerized medical image visualization and advances in analysis methods and computer-aided diagnosis[1],and is now,for example,a vital part of the early detection,diagnosis, and treatment of cancer.The challenge is to effectively process and analyze the images in order to effectively extract, quantify,and interpret this information to gain understanding and insight into the structure and function of the organs being imaged.The general goal is to understand the information and put it to practical use.A multitude of diagnostic medical imaging systems are used to probe the human body.They comprise both microscopic (viz. cellular level) and macroscopic (viz.organ and systems level) modalities.Interpretation of the resulting images requires sophisticated image processing methods that enhance visual interpretation and image analysis methods that provide automated or semiautomated tissue detection,measurement, and characterization [2–4].In general,multiple transformations will be needed in order to extract the data of interest from an image,and a hierarchy in the processing steps will be evident, e.g., enhancement will precede restoration,which will precede analysis,feature extraction,and classification[5].Often,these are performed sequentially, but more sophisticated tasks will require feedback of parameters to preceding steps so that the processing includes a number of iterative loops.Segmentation is one of the key tools in medical image analysis.The objective of segmentation is to provide reliable, fast, and effective organ delineation.While traditionally, particularly in computer vision, segmentation is seen as an early vision tool used for subsequent recognition, in medical imaging the opposite is often true. Recognition can be performed interactively by clinicians or automatically using robust techniques, while the objective of segmentation is to precisely delineate contours and surfaces. This can lead to effective techniques known as “intelligent scissors” in 2D and their equivalent in 3D. This paper divided as follows. starts off with a more “philosophical” section setting the background for this study. We argue for a segmentation context where highlevel knowledge, object information, and segmentation method are all separate. we survey in some detail a number of segment
Theory of the photocount statistics for multi-mode multi-frequency radiation fields
Michael Patra
Physics , 2009,
Abstract: We derive on the level of quantum optics expressions for the uncertainty of the photocount in a multi-mode multi-frequency setup. The result depends on the quantum correlations of the individual modes and the frequency spectrum of the radiation, the latter leading to a frequency beating sometimes referred to as dynamic laser speckle. When the mode structure of the radiation field is disturbed between source and detector, another contribution to the photocount uncertainty referred to as static speckle appears. To predict the size of this effect, we present a suitable definition of the etendue (or phase space volume) that links the number of modes of a radiation field to macroscopic quantities.
Influence of Spatial Correlations on the Lasing Threshold of Random Lasers
Michael Patra
Physics , 2003, DOI: 10.1103/PhysRevE.67.065603
Abstract: The lasing threshold of a random laser is computed numerically from a generic model. It is shown that spatial correlations of the disorder in the medium (i.e., dielectric constant) lead to an increase of the decay rates of the eigenmodes and of the lasing threshold. This is in conflict with predictions that such correlations should lower the threshold. While all results are derived for photonic systems, the computed decay rate distributions also apply to electronic systems.
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