OALib Journal期刊

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匹配条件: “Srivastava Vikas Kumar” ,找到相关结果约23117条。
Structure of odd $^{79,81,83}$Se isotopes with proton and neutron excitations across $Z=28$ AND $N= 40$
Vikas Kumar,P. C. Srivastava
Physics , 2013, DOI: 10.1142/S0218301313500912
Abstract: The recently measured experimental data of $^{79,81,83}$Se isotopes have been interpreted in terms of shell model calculations. The calculations have been performed in ${f_{5/2}pg_{9/2}}$ space with the recently derived interactions, namely with JUN45 and jj44b. To study the importance of the proton excitations across the $Z=28$ shell in this region. We have also performed calculation in ${fpg_{9/2}}$ valence space using an ${fpg}$ effective interaction with $^{48}$Ca core and imposing a truncation. Excitation energies, $B(2)$ values, quadrupole moments and magnetic moments are compared with experimental data when available. Present study reveals the importance of proton excitations across the $Z=28$ shell for predicting quadrupole and magnetic moments.
Feature Image Generation Using Low, Mid and High Frequency Regions for Face Recognition
Vikas Maheshkar,Sushila Kamble,Suneeta Agarwal,Vinay Kumar Srivastava
International Journal of Multimedia & Its Applications , 2012,
Abstract: In this paper, we propose a generation of feature image for face recognition. Feature image is generated using Discrete Cosine Transform (DCT), which tries to best classify different face images by maximizing the individual difference between face images. Low, Mid, and High frequency components of DCT are usedto hold different information of face by providing a local description of different facial components such as detailed smooth region description and, effective edge representation. Reduction in different frequency components is achieved using statistical measure such as standard deviation. A comparison of proposed work with other standard methods is done on ORL face datasets. An experimental result shows a significant improvement of the proposed scheme.
Comparison of two approaches of infraclavicular brachial plexus block for orthopaedic surgery below mid-humerus
Trehan Vikas,Srivastava Uma,Kumar Aditya,Saxena Surekha
Indian Journal of Anaesthesia , 2010,
Abstract: The brachial plexus in infraclavicular region can be blocked by various approaches. Aim of this study was to compare two approaches (coracoid and clavicular) regarding success rate, discomfort during performance of block, tourniquet tolerance and complications. The study was randomised, prospective and observer blinded. Sixty adult patients of both sexes of ASA status 1 and 2 requiring orthopaedic surgery below mid-humerus were randomly assigned to receive nerve stimulator guided infraclavicular brachial plexus block either by lateral coracoid approach (group L, n = 30) or medial clavicular approach (group M, n = 30) with 25-30 ml of 0.5% bupivacaine. Sensory block in the distribution of five main nerves distal to elbow, motor block (Grade 1-4), discomfort during performance of block and tourniquet pain were recorded by a blinded observer. Clinical success of block was defined as the block sufficient to perform the surgery without any supplementation. All the five nerves distal to elbow were blocked in 77 and 67% patients in groups L and M respectively. Successful block was observed in 87 and 73% patients in groups L and M, respectively (P > 0.05). More patients had moderate to severe discomfort during performance of block due to positioning of limb in group M (14 vs. 8 in groups M and L). Tourniquet was well tolerated in most patients with successful block in both groups. No serious complication was observed. Both the approaches were equivalent regarding success rate, tourniquet tolerance and safety. Coracoid approach seemed better as positioning of operative limb was less painful, coracoids process was easy to locate and the technique was easy to learn and master.
KTP laser photoselective vaporization of the prostate: an initial experience
Vikas Kumar,Rakesh Kapoor,Anand Dharaskar,Aneesh Srivastava
Turkish Journal of Urology , 2011,
Abstract: Objective: To review the initial experience of potassium-titanyl-phosphate (KTP) laser photoselective vaporization of the prostate (PVP). Materials and methods: Thirty patients with benign prostatic enlargement who underwent PVP at our institution between March 2007 and June 2009 were prospectively analyzed. The efficacy of the procedure was assessed using the International Prostate Symptom Score (IPSS), Quality of Life (QoL) score, maximum flow rate (QMax), and post-void residual volume (PVR) at 3, 6, and 12 months after surgery and then annually thereafter. Operative time, laser energy and fiber use, and any procedural or postoperative complications were noted. Results: Fourteen (47%) patients opted for PVP by choice, and 16 (53%) underwent PVP because they were at high-risk for transurethral resection of the prostate (TURP), KTP laser PVP was successfully performed in all patients without any intraoperative complications. The median prostate volume was 47 g (range 25-136 g). Median operative time, laser energy, and hospital stay were 84 min (range 66-109 min), 126.1 kJ (range 27.6-235.5 kJ), and 2 days (range 1-9 days), respectively. IPSS, QoL score, QMax, and PVR improved from preoperative median values of 22, 04, 09 mL/sec, and 206 mL to 03, 01, 19.7 mL/sec, and 30.5 mL, respectively, postoperatively. No patient required blood transfusion or had TURP syndrome. Urethral stricture developed in only 2 (6.6%) patients in our study. Conclusion: Although the financial cost of laser installation is difficult to justify in developing countries, our initial results demonstrate that KTP laser PVP is a treatment method that can be adopted to treat patients with benign prostatic hyperplasia safely and effectively, especially those patients with significant systemic comorbidities.
Physical Growth Standards for Urban Adolescents (10-15 Years) from South Gujarat
Thakor Hitendra,Kumar Pradeep,Desai Vikas,Srivastava Ratan
Indian Journal of Community Medicine , 2000,
High-spin structures of $^{77,79,81,83}$As isotopes
Vikas Kumar,P. C. Srivastava,Irving O. Morales
Physics , 2015, DOI: 10.1142/s0217732315500935
Abstract: In the present work we report comprehensive set of shell model calculations for arsenic isotopes. We performed shell model calculations with two recent effective interactions JUN45 and jj44b. The overall results for the energy levels and magnetic moments are in rather good agreement with the available experimental data. We have also reported competition of proton- and neutron-pair breakings analysis to identify which nucleon pairs are broken to obtain the total angular momentum of the calculated states. Further theoretical development is needed by enlarging model space by including $\pi 0f_{7/2}$ and $\nu 1d_{5/2}$ orbitals.
High-spin structures of $^{86,87,88,89}$Y: a shell model interpretation
P. C. Srivastava,Vikas Kumar,M. J. Ermamatov
Physics , 2014, DOI: 10.1134/S1063778814100111
Abstract: In this work nuclear structure properties of $^{86,87,88,89}$Y isotopes have been investigated using large-scale shell-model calculations within the full $f_{5/2}pg_{9/2}$ model space. The calculations have been performed with JUN45 and jj44b effective interactions that have been proposed for use in the $f_{5/2}$, $p_{3/2}$, $p_{1/2}$, $g_{9/2}$ model space for both protons and neutrons. Reasonable agreement between experimental and calculated values are obtained. This work will add more information to previous study by projected shell model [Eur. Phys. J. A 48, 138 (2012)] where full-fledged shell model calculations proposed for these nuclei.
Shell model description of Gamow-Teller strengths for $^{42}$Ti, $^{46}$Cr, $^{50}$Fe and $^{54}$Ni
Vikas Kumar,P. C. Srivastava,Jorge G. Hirsch
Physics , 2015,
Abstract: A systematic shell model description of the experimental Gamow-Teller transition strength distributions in $^{42}$Ti, $^{46}$Cr, $^{50}$Fe and $^{54}$Ni is presented. These transitions have been recently measured via $\beta$ decay of these $T_z$=-1 nuclei, produced in fragmentation reactions at GSI and also with ($^3${He},$t$) charge-exchange (CE) reactions corresponding to $T_z = + 1$ to $T_z = 0$ carried out at RCNP-Osaka. The calculations are performed in the $pf$ model space, using the GXPF1a and KB3G effective interactions. Qualitative agreement is obtained for the individual transitions, while the calculated summed transition strengths closely reproduce the observed ones.
Negi Richa Srivastava,Bindra Rattan Lal,Srivastava Vikas Kumar,Kumar Dhirendra
International Research Journal of Pharmacy , 2013, DOI: 10.7897/2230-8407.04333
Abstract: The Zingiberaceae, the largest family in the Zingerabales, comprises nearly 50 genera and 1000 species and is pantropical concentrated mainly in the old world, chiefly in Indomalaysia. Members of the family yield species, dyes, perfumes, medicines and a number of ornamental species are cultivated for their ornamental flowers. Curcuma is one of the important ‘Rasayana’ drugs mentioned in Ayurveda. In the present study three successive extractions of plant rhizomes viz. C. amada, C. malabarica and C. zedoaria were undertaken by using various solvent like alcohol, hydro-alcohol and water in their increasing polarity and the extracts thus obtained were subjected for their phytochemical analysis, followed by Thin Layer Chromatographic examination by optimizing the solvent system.
Analysis of proton and neutron pair breakings: High-spin structures of $^{124-127}$Te isotopes
Vikas Kumar,P. C. Srivastava,M. J. Ermamatov,Irving O. Morales
Physics , 2014, DOI: 10.1016/j.nuclphysa.2015.07.012
Abstract: In the present work recently available experimental data for high-spin states of four nuclei, $^{124}_{\ 52}$Te, $^{125}_{\ 52}$Te, $^{126}_{\ 52}$Te, and $^{127}_{\ 52}$Te have been interpreted using state-of-the-art shell model calculations. The calculations have been performed in the $50-82$ valence shell composed of $1g_{7/2}$, $2d_{5/2}$, $1h_{11/2}$, $3s_{1/2}$, and $2d_{3/2}$ orbitals. We have compared our results with the available experimental data for excitation energies and transition probabilities, including high-spin states. The results are in reasonable agreement with the available experimental data. The wave functions, particularly, the specific proton and neutron configurations which are involved to generate the angular momentum along the yrast lines are discussed. We have also estimated overall contribution of three-body forces in the energy level shifting. Finally, results with modified effective interaction are also reported.

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