OALib Journal期刊

ISSN: 2333-9721




2016 ( 8 )

2015 ( 21 )

2014 ( 50 )

2013 ( 86 )


匹配条件: “Upadhyay Shakti” ,找到相关结果约476条。
Phenanthrenes of Eulophia ochreata Lindl.
Kshirsagar Rajendra,Kanekar Yogesh,Jagtap Suresh,Upadhyay Shakti
International Journal of Green Pharmacy , 2010,
Abstract: Pawra tribe of Satpuda mountain ranges that belong to Maharashtra region, India, is known to use tubers of Eulophia ochreata for rejuvenating and aphrodisiac properties and also for curing rheumatism. For systematic scientific validation of folk claims of E. ochreata tubers, we report here the collection, extraction, isolation and spectral characterization of molecules and also its evaluation for free radical scavenging activity. Isolation of molecules was carried out on activity-guided fractionation in 2,2 ′ -diphenyl-1-picrylhydrazyl assay. This is the first report of isolation of 9,10-Dihydro-2,5-Dimethoxyphenanthrene-1,7-diol and 5,7-Dimethoxyphenanthrene-2,6-diol from this orchid.
Some Construction Methods of A-Optimum Chemical Balance Weighing Designs  [PDF]
Rashmi Awad, Shakti Banerjee
Journal of Applied Mathematics and Physics (JAMP) , 2014, DOI: 10.4236/jamp.2014.213136
Abstract: Some new construction methods of the optimum chemical balance weighing designs and pairwise efficiency and variance balanced designs are proposed, which are based on the incidence matrices of the known symmetric balanced incomplete block designs. Also the conditions under which the constructed chemical balance weighing designs become A-optimal are also been given.
Web Testing: Tool, Challenges and Methods
Shakti Kundu
International Journal of Computer Science Issues , 2012,
Abstract: Web testing is the name given to software testing that focuses on web applications. Issues such as the security of the web application, the basic functionality of the site, its accessibility to handicapped users and fully able users, as well as readiness for expected traffic and number of users and the ability to survive a massive spike in user traffic, both of which are related to load testing. In this paper web testing based on tool, challenges and methods have been discussed which will help in handling some challenges during the website development. This paper presents best methods for testing a web application.
Shakti Kundu
International Journal on Computer Science and Engineering , 2012,
Abstract: With an explosive growth of the World Wide Web, websites are playing an important role in providing an information and knowledge to the end users. Web usage patterns are an important aspect to discover hidden and meaningful information. It will be big challenge in web mining when the volume of traffic is large and the volume of web data is still in the growing phase. To face the challenge an intelligent approach of web traffic analysis has been highlighted in this paper.
Prediction of Effective Elastic Modulus of Biphasic Composite Materials  [PDF]
Anupama Upadhyay, Ramvir Singh
Modern Mechanical Engineering (MME) , 2012, DOI: 10.4236/mme.2012.21002
Abstract: Two semi-empirical approaches for prediction of elastic modulus of biphasic composites have been proposed. Developed relations are for pore free matrix and pore free filler and found to depend on nonlinear contribution of volume fraction of constituents as well as ratio of elastic properties of individual phases. These relations are applied for the calculation of effective elastic modulus mainly for Al2O3-NiAl, SiC-Al, Alumina-Zirconia, Al-Al2O3, W-glass and Flax-Resin composite materials. Theoretical predictions using developed relations are compared with experimental data. It is found that the predicted values of effective elastic modulus using modified relations are quite close to the experimental results.
Single-Channel Speech Enhancement Using Critical-Band Rate Scale Based Improved Multi-Band Spectral Subtraction  [PDF]
Navneet Upadhyay, Abhijit Karmakar
Journal of Signal and Information Processing (JSIP) , 2013, DOI: 10.4236/jsip.2013.43040

This paper addresses the problem of single-channel speech enhancement in the adverse environment. The critical-band rate scale based on improved multi-band spectral subtraction is investigated in this study for enhancement of single-channel speech. In this work, the whole speech spectrum is divided into different non-uniformly spaced frequency bands in accordance with the critical-band rate scale of the psycho-acoustic model and the spectral over-subtraction is carried-out separately in each band. In addition, for the estimation of the noise from each band, the adaptive noise estimation approach is used and does not require explicit speech silence detection. The noise is estimated and updated by adaptively smoothing the noisy signal power in each band. The smoothing parameter is controlled by a-posteriori signal-to-noise ratio (SNR). For the performance analysis of the proposed algorithm, the objective measures, such as, SNR, segmental SNR, and perceptual evaluations of the speech quality are conducted for the variety of noises at different levels of SNRs. The speech spectrogram and objective evaluations of the proposed algorithm are compared with other standard speech enhancement algorithms and proved that the musical structure of the remnant noise and background noise is better suppressed by the proposed algorithm.

A Multi-Band Speech Enhancement Algorithm Exploiting Iterative Processing for Enhancement of Single Channel Speech  [PDF]
Navneet Upadhyay, Abhijit Karmakar
Journal of Signal and Information Processing (JSIP) , 2013, DOI: 10.4236/jsip.2013.42027

This paper proposes a multi-band speech enhancement algorithm exploiting iterative processing for enhancement of single channel speech. In the proposed algorithm, the output of the multi-band spectral subtraction (MBSS) algorithm is used as the input signal again for next iteration process. As after the first MBSS processing step, the additive noise transforms to the remnant noise, the remnant noise needs to be further re-estimated. The proposed algorithm reduces the remnant musical noise further by iterating the enhanced output signal to the input again and performing the operation repeatedly. The newly estimated remnant noise is further used to process the next MBSS step. This procedure is iterated a small number of times. The proposed algorithm estimates noise in each iteration and spectral over-subtraction is executed independently in each band. The experiments are conducted for various types of noises. The performance of the proposed enhancement algorithm is evaluated for various types of noises at different level of SNRs using, 1) objective quality measures: signal-to-noise ratio (SNR), segmental SNR, perceptual evaluation of speech quality (PESQ); and 2) subjective quality measure: mean opinion score (MOS). The results of proposed enhancement algorithm are compared with the popular MBSS algorithm. Experimental results as well as the objective and subjective quality measurement test results confirm that the enhanced speech obtained from the proposed algorithm is more pleasant to listeners than speech enhanced by classical MBSS algorithm.

Effects of plant latex based anti-termite formulations on Indian white termite Odontotermes obesus (Isoptera: Odontotermitidae) in sub-tropical high infestation areas  [PDF]
Ravi Kant Upadhyay
Open Journal of Animal Sciences (OJAS) , 2013, DOI: 10.4236/ojas.2013.34042
Abstract: In the present investigation various bioassays were conducted to evaluate the anti-termite efficacy of plant latex based formulations to control population of Indian white termite in subtropical soil. Results reveal that crude latex, its fractions and combinatorial fractions have shown very high toxicity against O. obesus. The LD50 values for different latex fractions of 24 h were in a range of 5.0-17.613 μg/mg while combined mixtures of Calotropis procera have shown synergistic activity against termites and caused comparably high mortality with LD50 1.987-6.016 μg/mg. The mortality rate was found dose and time dependent as it was found to be increased with an increase in dose and exposure period. In olfactometry tests, C. procera latex solvent fractions have shown significant repellency at a very low dose 0.010-0.320 μg/mg. Interestingly, solvent fractions have significantly repelled large numbers of worker termites due to volatile action of active components of latex and different additives. ED50 values obtained in crude latex were 0.121 μg/mg body weights while combinatorial formulations have shown ED50 in between 0.015-0.036 μg/mg. Statistical analysis of repelled and un-repelled termites gave a low Chi-square value (X2
Antimicrobial Activity of Fruit Latexes from Ten Laticiferous Plants  [PDF]
Ravi Kant Upadhyay
American Journal of Plant Sciences (AJPS) , 2015, DOI: 10.4236/ajps.2015.63053
Abstract: In the present investigation antibacterial activity of latexes from ten Indian plant species Spondias dulcis (Amra), Diospyros melanoxylon (Tendu), Terminalia bellirica (Wahera), Ficus glomerata (Gular), Phyllanthus emblica (Awla), Thevetia nerifolia (Kaner), Carica papaya (Papita), Calotropis procera (Ak), Ficus benghalensis (Bargad), Atrocarpus heterophyllus (Kathal) collected from Go-rakhpur, North India were determined in various in vitro systems. MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentration) values were determined in growth inhibitory bioassays by using different increasing concentrations of various latex extracts. Latex samples were diluted by using serial micro dilution method up to 10-10 method with Luria broth culture medium. These values were obtained significantly 2 - 3 times lower than that of broad spectrum antibiotic drugs. Besides this, inhibition zone diameters were measured in agar disc diffusion assay. A known volume i.e. 0.1 - 20 μg/μl of each latex were coated on separate sterile filter paper discs (Whatman No. 1) measuring 6 mm in size. Latex fractions registered significantly higher growth inhibition than that of broad spectrum antimicrobial drugs. Present study indicates the potential use of shows that both latex and its components and latex as are valuable source of medicinal products/active principles that can be used for treatment of life threatening infectious diseases. Because of higher inhibitory and cidal potential obtained in latexes than the synthetic drugs these that could lead to become efficient phytomedicines mainly to have and develop as complete drug formulations against to control infectious microbes.
GC-MS Analysis and in Vitro Antimicrobial Susceptibility of Foeniculum vulgare Seed Essential Oil  [PDF]
Ravi Kant Upadhyay
American Journal of Plant Sciences (AJPS) , 2015, DOI: 10.4236/ajps.2015.67110
Abstract: Essential oil from seeds of Foeniculum vulgare was extracted on Clevenger apparatus. Essential oil was analyzed on Gas-Chromatography-Mass spectrometry (GC-MS) from which thirty six components were identified, among which 6 major and 30 minor components having different structural formulae and molecular weight representing total 99.98% of oil. Essential was investigated for its antibacterial and antifungal activity against seven infectious microbial pathogens. Paper disc diffusion and serial micro-dilution assays were performed for the determination of inhibition zone (DIZ) diameters and minimal inhibitory concentration, respectively. The Foeniculum vulgare essential oil showed the Diameter of Inhibition Zone (DIZ) ranging from 19.4 ± 0.07 - 26.4 ± 0.09 mm at a concentration level of 28 μg/disc in all the ten strains tested. The minimum inhibitory concentration (MIC) of essential oil against bacterial and fungal strains was obtained in the range of 7.0 - 56 μg/ml. Antibacterial and antifungal activity of Foeniculum vulgare essential oil is due to the presence of certain secondary plant metabolites such as terpenoids, steroids and flavonoids, esters and acids which are identified in the essential oil. The oil components can be further studied for their biological activity and overcome the problem of drug resistance in microbes.

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