OALib Journal期刊

ISSN: 2333-9721



匹配条件: “ Priyadarshini Sanghamitra Sahoo” ,找到相关结果约896条。
Effect of Strontium Substitution on Impedance Properties of Ba5GdTi3V7O30 Ceramics  [PDF]
Bana Bihari Mohanty, Priyadarshini Sanghamitra Sahoo, Bala Krushna Giri, Jagata Nanda Panda, Ram Naresh Prasad Choudhary
Journal of Modern Physics (JMP) , 2018, DOI: 10.4236/jmp.2018.94043
Abstract: A series of compounds Ba5-xSrxGdTi3V7O30 (x = 0 - 5), belonging to tungsten bronze family were prepared by a high-temperature solid-state reaction route. Using X-Ray diffraction technique and Scanning Electron Micrograph, the formation and surface morphology of the compounds were studied. The X-Ray diffraction study informs the formation of single-phase orthorhombic structures. The substitution of Sr ion with increasing concentration in the compounds as per formula resulted in a variation of the electrical properties. Study of electrical properties using impedance analyzer exhibits: 1) the presence of negative temperature coefficients of resistance (NTCR) behavior; 2) presence of temperature dependent electrical relaxation phenomena; 3) evidences of single electrical relaxation attributed to the presence of bulk contribution to the electrical properties for pure Ba5GdTi3V7O30 compound; 4) an enhancement in the barrier to the mobility of charge carriers on Sr-substitution. The effects of Sr on changes in the electrical conductivity as a function of temperature at different frequency are described based on impedance spectrum analysis.
Preparation and Study of Dielectric and Electrical Conductivity of Ba5NdTi3V7O30 Ceramics  [PDF]
Jagatananda Panda, Bana Bihari Mohanty, Priyadarshini Sanghamitra Sahoo, Ram Naresh Prasad Choudhary
Open Access Library Journal (OALib Journal) , 2018, DOI: 10.4236/oalib.1104834
Ba5NdTi3V7O30 is a tungsten bronze structured ceramic sample, prepared by Solid State reaction route at high temperature (950℃). The room temperature XRD analysis confirms orthorhombic crystal structure of the compound. Dielectric peak is observed at ~460℃ showing the transition of the compound from ferroelectric to paraelectric phase. Appearance of hysteresis loop confirms the existence of ferroelectric properties in the materials. Different values of activation energy in different temperature regions of the ac conductivity versus inverse absolute temperature graph exhibit mixed type of conduction process in the compound (i.e., ionic-polaronic and space charge generated from the oxygen ion vacancies).
Impedance Spectroscopy of Ba5GdTi3V7O30  [PDF]
Bana Bihari Mohanty, Priyadarshini Sanghamitra Sahoo, Mohapatra Prakash Kumar Sahoo, Ram Naresh Prasad Choudhary, Ram Naresh Prasad Choudhary, Ram Naresh Prasad Choudhary, Ram Naresh Prasad Choudhary
Journal of Modern Physics (JMP) , 2012, DOI: 10.4236/jmp.2012.35050
Abstract: The polycrystalline sample of Ba5GdTi3V7O30 , a member of tungsten bronze structural family, was prepared by a high-temperature solid-state reaction technique. A preliminary X-ray diffraction analysis suggests the formation of single-phase compound with orthorhombic structure. The effect of temperature on impedance parameters was studied using an impedance analyzer in a wide frequency range (102- 106 Hz) at different temperatures. The real and imaginary part of complex impedance traces semicircle(s) in the complex plane. The temperature dependent plots reveal the presence of both bulk and grain boundary effects. The bulk resistance of the material decreases with rise in temperature. This exhibits a typical negative temperature coefficient of resistance (NTCR) behavior of the material. The modulus analysis suggests a possible hopping mechanism for electrical transport processes of the material. The nature of variation of dc conductivity suggests Arrhenius type of electrical conductivity.
Influence of language and ancestry on genetic structure of contiguous populations: A microsatellite based study on populations of Orissa
Sanghamitra Sahoo, VK Kashyap
BMC Genetics , 2005, DOI: 10.1186/1471-2156-6-4
Abstract: The allele distribution pattern showed uniformity in the studied groups with approximately 81% genetic variability within populations. The coefficient of gene differentiation was found to be significantly higher in tribes (0.014) than caste groups (0.004). Genetic variance between the groups was 0.34% in both ethnic and linguistic clusters and statistically significant only in the ethnic apportionment. Although the populations were genetically close (FST = 0.010), the contemporary caste and tribal groups formed distinct clusters in both Principal-Component plot and Neighbor-Joining tree. In the phylogenetic tree, the Orissa Brahmins showed close affinity to populations of North India, while Khandayat and Gope clustered with the tribal groups, suggesting a possibility of their origin from indigenous people.The extent of genetic differentiation in the contemporary caste and tribal groups of Orissa is highly significant and constitutes two distinct genetic clusters. Based on our observations, we suggest that since genetic distances and coefficient of gene differentiation were fairly small, the studied populations are indeed genetically similar and that the genetic structure of populations in a geographical region is primarily influenced by their ancestry and not by socio-cultural hierarchy or language. The scenario of genetic structure, however, might be different for other regions of the subcontinent where populations have more similar ethnic and linguistic backgrounds and there might be variations in the patterns of genomic and socio-cultural affinities in different geographical regions.Human society in a geographic area develops when colonizing populations bring along with them different languages, cultures and technological advancements over a period of time. As more populations migrate to settle in the same area, they are either eliminated, subjugated or absorbed [1]. In India, majority of incoming populations have been absorbed, forming heterogeneous and complex
Synthesis and Electrical Analysis of Ba5GdTi3V7O30 Ceramics  [PDF]
Bana B. Mohanty, Priyadarshini S. Sahoo, Mahapatra P. K. Sahoo, Ram N. P. Choudhary
Materials Sciences and Applications (MSA) , 2012, DOI: 10.4236/msa.2012.33027
Abstract: A polycrystalline sample of Ba5GdTi3V7O30 was prepared using a mixed oxide method at high temperature (i.e., at 950℃). The formation of single-phase compound with orthorhombic structure at room temperature was confirmed from preliminary X-ray diffraction study. Detailed studies of dielectric properties of Ba5GdTi3V7O30, investigated in a wide frequency range (102 - 106 Hz) at different temperatures (33℃ - 500℃) showed that these properties of the material are strongly dependent on frequency and temperature. The existence a dielectric anomaly suggests that the compound has a transition temperature at ~385℃. The nature of the variation of conductivity and value of activation energy in different regions, calculated from the temperature dependence of ac conductivity (dielectric data) suggest that the conduction process is of mixed type (i.e., ionic-polaronic and space charge generated from the oxygen ion vacancies). The ac conductivity spectrum obeys Jonscher’s universal power law.
Deletions in the Y-derived amelogenin gene fragment in the Indian population
VK Kashyap, Sanghamitra Sahoo, T Sitalaximi, R Trivedi
BMC Medical Genetics , 2006, DOI: 10.1186/1471-2350-7-37
Abstract: Samples were analyzed using commercial genetic profiling kits. Those that exhibited failures in amelogenin-based gender identification were further analyzed with published as well as newly designed primers to ascertain the nature and extent of mutation.The failure rate among Indian males was 0.23 %. Though the exact size and nature of the deletion (single point mutations at a number of positions or a single large deletion) could not be determined in the present study, it is inferred that the deletion spans a region downstream of the reverse primer-binding site of commercially available amelogenin primer sets. Deletions were conspicuously absent among the Mongoloid tribes of Northeast India, while both caste and tribal groups harbored these mutations, which was predominantly among the Y-chromosomes belonging to J2 lineage.Our study indicates that the different amelogenin primer sets currently included in genetic profiling multiplex kits may result in erroneous interpretations due to mutations undetectable during routine testing. Further there are indications that these mutations could possibly be lineage-specific, inherited deletions.Genotyping the X-Y homologous amelogenin gene segment for gender identification is widely used for DNA profiling in DNA databasing, forensic casework, archeological specimens, preimplantation and prenatal diagnoses [1-4]. The amelogenin gene is a single copy gene, homologues of which are located on Xp22.1-Xp22.3 and Yp 11.2 [5]. Regions on this gene that are sufficiently conserved are amplified for simultaneous detection of the X and Y alleles in gender identification procedures. Primers bind to the first intron region of the amelogenin gene on the X and Y-chromosomes [6] and amplify regions that differ in base sequence, hence resulting in products that are easily distinguishable by differences in size and sequence. The most widely used primer set [6] delimits a 6 bp deletion on the X-chromosome and produces fragments of 106 bp and 112 b
Rapid, Efficient and High-Performance Protocol for Agrobacterium rhizogenes-Mediated Hairy Root Transformation of the Common Bean Phaseolus vulgaris  [PDF]
Sanghamitra Khandual, Pallavolu Maheswara Reddy
Advances in Bioscience and Biotechnology (ABB) , 2014, DOI: 10.4236/abb.2014.54041

A rapid, efficient and high-performance transformation protocol employing Agrobacterium rhizogenes was developed for the common bean Phaseolus vulgaris. In this study, we examined competencies of various protocols to induce and explants that respond to hairy root transformation in bean plants. Utilizing young seedlings with severed radicles/hypocotyls, we developed a highly efficient procedure for achieving hairy root transformation frequencies as high as 100% as visualized by GUS reporter gene expression system. Transgenic hairy roots in these young composite plants were susceptible to nodulation by rhizobia, and form an excellent system for high throughput genomic analysis to study root biology and endosymbiosis in common bean.

Early diagnosis of airway closure from pigtail signature capnogram and its management in intubated small infants undergoing general anaesthesia for surgery
Mishra Sanghamitra
Indian Journal of Anaesthesia , 2010,
Abstract: Spontaneous glottis closure during expiration in infants is a normal protective reflex that helps prevent alveolar and small airway collapse (due to compliant chest wall) and thereby maintains functional residual capacity. Endotracheal intubation eliminates this protective mechanism and puts the infant into the risk of hypoxaemia and hypercarbia. This report sums up the early detection of airway closure in a series of three intubated small infants undergoing surgery with general anaesthesia, by the appearance of typical pigtail shaped capnogram, associated with decreased end tidal carbon dioxide and mild hypoxaemia, which was successfully managed by early institution of positive end expiratory pressure.
The Role of Acid Strength of Modified NaX Zeoliteson Gas Phase Ethylation of Benzene
Sanghamitra Barman
Journal of Applied Sciences , 2010,
Abstract: The role of acid strength of modified NaX zeolites in gas phase ethylation of benzene were studied over Ce exchanged NaX zeolite of different types. Acidity of the modified zeolite was investigated by means of adsorbing ammonia at different temperature. The conversion of reactantsvaries with the acid strength as well as the different types of the zeolites. The strong acid sites are active centers while the weak acid sites are inactive. The influences of various process parameters such as temperature, space-time and the feed ratio of benzene to ethanol on benzene conversion over most acidic zeolite were studied. The kinetic and adsorption constants of the rate equations were estimated by the best fit. From the estimated kinetic constants, the activation energies and frequency factors for various reactions were determined. The activation energy values compared well with those reported by other investigators for same reactions over similar catalysts.
Strengthening Civil Society: Lessons from the Consumer Forum at Basrur in Karnataka
Priyadarshini Kedlaya
Socio-Legal Review , 2010,
Abstract: Necessitated by the inherent limitations of the market and failures in governance by the State, the search for alternative solutions has witnessed the emergence of the sphere of civil society. Organisations of ordinary people have taken up the task of ensuring better governance through their interactions with both the state and the market. The Consumer Forum at Basrur is a civil society organisation that seeks to build capacities amongst citizens and empower them to demand greater accountability from both the government and private players. Its key tool is effective communication, particularly through letter-writing, wherein the Forum guides the consumers in establishing contact with suppliers and officials and finding solutions to their problems in a cost effective and transparent manner. In this paper, the author studies the methodology and work of this Forum in order to assess the possibility of replicating the model.

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