30 research outputs found

    Magnetic Response of NiFe2O4 nanoparticles in polymer matrix

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    We report the magnetic properties of magnetic nano-composite, consisting of different quantity of NiFe2O4 nanoparticles in polymer matrix. The nanoparticles exhibited a typical magnetization blocking, which is sensitive on the variation of magnetic field, mode of zero field cooled/field cooled experiments and particle quantity in the matrix. The samples with lower particle quantity showed an upturn of magnetization down to 5 K, whereas the blocking of magnetization dominates at lower temperatures as the particle quantity increases in the polymer. We examine such magnetic behaviour in terms of the competitive magnetic ordering between core and surface spins of nanoparticles, taking into account the effect of inter-particle (dipole-dipole) interactions on nanoparticle magnetic dynamics.Comment: 5 fihur

    Magnetic enhancement of Co0.2_{0.2}Zn0.8_{0.8}Fe2_2O4_4 spinel oxide by mechanical milling

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    We report the magnetic properties of mechanically milled Co0.2_{0.2}Zn0.8_{0.8}Fe2_2O4_4 spinel oxide. After 24 hours milling of the bulk sample, the XRD spectra show nanostructure with average particle size \approx 20 nm. The as milled sample shows an enhancement in magnetization and ordering temperature compared to the bulk sample. If the as milled sample is annealed at different temperatures for the same duration, recrystallization process occurs and approaches to the bulk structure on increasing the annealing temperatures. The magnetization of the annealed samples first increases and then decreases. At higher annealing temperature (\sim 10000^{0}C) the system shows two coexisting magnetic phases {\it i.e.}, spin glass state and ferrimagnetic state, similar to the as prepared bulk sample. The room temperature M\"{o}ssbauer spectra of the as milled sample, annealed at 3000^{0}C for different durations (upto 575 hours), suggest that the observed change in magnetic behaviour is strongly related with cations redistribution between tetrahedral (A) and octahedral (O) sites in the spinel structure. Apart from the cation redistribution, we suggest that the enhancement of magnetization and ordering temperature is related with the reduction of B site spin canting and increase of strain induced anisotropic energy during mechanical milling.Comment: 14 pages LaTeX, 10 ps figure

    Transient domain walls and lepton asymmetry in the Left-Right symmetric model

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    It is shown that the dynamics of domain walls in Left-Right symmetric models, separating respective regions of unbroken SU(2)_L and SU(2)_R in the early universe, can give rise to baryogenesis via leptogenesis. Neutrinos have a spatially varying complex mass matrix due to CP-violating scalar condensates in the domain wall. The motion of the wall through the plasma generates a flux of lepton number across the wall which is converted to a lepton asymmetry by helicity-flipping scatterings. Subsequent processing of the lepton excess by sphalerons results in the observed baryon asymmetry, for a range of parameters in Left-Right symmetric models.Comment: v2 version accepted for publication in Phys. Rev. D. Discussion in Introduction and Conclusion sharpened. Equation (12) corrected. 16 pages, 3 figure files, RevTeX4 styl

    Search for jet extinction in the inclusive jet-pT spectrum from proton-proton collisions at s=8 TeV

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    Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published articles title, journal citation, and DOI.The first search at the LHC for the extinction of QCD jet production is presented, using data collected with the CMS detector corresponding to an integrated luminosity of 10.7  fb−1 of proton-proton collisions at a center-of-mass energy of 8 TeV. The extinction model studied in this analysis is motivated by the search for signatures of strong gravity at the TeV scale (terascale gravity) and assumes the existence of string couplings in the strong-coupling limit. In this limit, the string model predicts the suppression of all high-transverse-momentum standard model processes, including jet production, beyond a certain energy scale. To test this prediction, the measured transverse-momentum spectrum is compared to the theoretical prediction of the standard model. No significant deficit of events is found at high transverse momentum. A 95% confidence level lower limit of 3.3 TeV is set on the extinction mass scale

    Searches for electroweak neutralino and chargino production in channels with Higgs, Z, and W bosons in pp collisions at 8 TeV

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    Searches for supersymmetry (SUSY) are presented based on the electroweak pair production of neutralinos and charginos, leading to decay channels with Higgs, Z, and W bosons and undetected lightest SUSY particles (LSPs). The data sample corresponds to an integrated luminosity of about 19.5 fb(-1) of proton-proton collisions at a center-of-mass energy of 8 TeV collected in 2012 with the CMS detector at the LHC. The main emphasis is neutralino pair production in which each neutralino decays either to a Higgs boson (h) and an LSP or to a Z boson and an LSP, leading to hh, hZ, and ZZ states with missing transverse energy (E-T(miss)). A second aspect is chargino-neutralino pair production, leading to hW states with E-T(miss). The decays of a Higgs boson to a bottom-quark pair, to a photon pair, and to final states with leptons are considered in conjunction with hadronic and leptonic decay modes of the Z and W bosons. No evidence is found for supersymmetric particles, and 95% confidence level upper limits are evaluated for the respective pair production cross sections and for neutralino and chargino mass values

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    Not AvailableThe study was taken up to compare the content broadcasted and good management practices followed in three community radio stations (CRS) operational under state agricultural university (SAU), Krishi Vigyan Kendra (KVK) and non-government organization (NGO). A sum of 120 listeners and 30 staff members were interviewed. Some of the good management practices of SAU-CRS recorded were: more number of village volunteers, versatile content creation, connecting with sponsoring agencies, knowledge back up by scientists. KVK-CRS practiced a messaging service to give alert to the listeners about important programmes. NGO-CRS maintained 12 members’ content management committee, which comprised rural women and innovative farmers. It has also installed wind mill to generate electricity during power cut. Major programmes aired from the community radios were listed across broadcast timings subjects covered, duration, frequency per week, format of presentation and resource person.Not Availabl

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    Not AvailableThe community radio has made an impression in all grounds of rural society in which there was a need to assess socio-technological empowerment of rural households. The study was taken up to compare the status of community members’ participation in community radios, operational under three different hosting agencies i.e. State Agricultural University (SAU), Krishi Vigyan Kendra (KVK) and Non-Government Organization (NGO). The community radio stations namely Pantnagar Janvani (G.B. Pant University of Agriculture and Technology), Pravara (KVK, Ahmednagar) and Yeralavani (Yerala Projects Society, Sangli) were selected purposively. Four villages have been selected randomly from one purposively selected block. Forty (40) respondents from four randomly selected villages from each CRS coverage area/ broadcast range along with 10 staff members of each CRS were selected for the study. Thus, a total of 150 respondents constituted the sample for the study. About 43 per cent of respondents had low level of participation in programme production and broadcasting followed by moderate level (40 %) and high level (17.50 %). Education and perception about CRS programmes were significantly influencing extent of participation of respondents.Not Availabl

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    Not AvailableInformation and Communication Technology (ICT) has influenced and changed rural women life very dramatically and has been proved vital tool for their empowerment. Despite major advancement in technology, accessibility and use of various ICT tools have been a major challenge in for rural women in India. The present study was undertaken for assessing barriers in adoption and use of Information and Communication Technology (ICT) among rural women. The study was conducted in Uttar Pradesh. 120 respondents were selected through simple random technique and data were collected from these respondents with the help of structured interview scheduled. Finding of the study suggested that the technological barriers (mean rank =297.34) found to be the most important factor which act as barrier in using ICT by rural women followed by cultural barrier (mean rank =285.54) followed by infrastructural barrier (mean rank =256.51) and personal barrier (122.59). Among technological barrier restricted accessibility to ICT tools (mean rank=4.21) and language barriers (mean rank=3.96) were found major barrier. Similarly in case of Infrastructural barrier poor electricity services (mean rank =2.16) followed by poor network connectivity (mean rank 2.13). Study revealed several barriers in use of ICT tools by rural women, therefore it is essentially needed to remove these barriers which discourage rural women to adopt and use ICT through various policy measure.Not Availabl

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    Not AvailableOver the period of time many information and communication technology based projects have emerged in India, supplemented traditional extension services by providing information to various stakeholders. But accessibility of information remain a challenge for most of the people particularly rural women because of poor infrastructure support, illiteracy,lack of skilled and many others. This creates a information gap between men and women and this gap was more widen for rural women. Information and communication technologies and tools have potential to provide solution to existing information asymmetry in various lagging sectors like agriculture and can ensure more equitable information share and thus helps in empowering rural women. Connecting Dream Foundation (an ngo’s)ICT based project have made significant contribution in information dissemination on diverse range of subjects and thus helps in reducing information gap for rural women by focusing on women information needs.The present study was undertaken for assessing its effectiveness in information dissemination and advisory services to rural women in two districts of Uttar Pradesh Hapur and Ghaziabad where Connecting Dream Foundation was working since last four years. Data were collected from 120 respondents (rural women) who were associated with CDF. The effectiveness was measured by effectiveness index developed for the purpose. The study revealed that the advisory services rendered by Connecting Dream foundation was found effective.Not Availabl
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