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Search Results: 1 - 10 of 151246 matches for " Raj K. Singh "
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Characterization of Wet and Dry Deposition in the Downwind of Industrial Sources in a Dry Tropical Area
Raj K. Singh,Raj M. Agrawal
The Scientific World Journal , 2001, DOI: 10.1100/tsw.2001.388
Abstract:
Antimicrobial and Herbal Drug Resistance in Enteric Bacteria Isolated from Faecal Droppings of Common House Lizard/Gecko (Hemidactylus frenatus)
Bhoj R. Singh,Vidya Singh,N. Ebibeni,Raj K. Singh
International Journal of Microbiology , 2013, DOI: 10.1155/2013/340848
Abstract: From 194 faecal dropping samples of common house geckos collected from offices (60), houses (88), integrated farm units (IFS,18) and hostels, guest houses, and dining rooms of different canteen/mess (HGM, 28), 326 bacterial isolates of enteric bacteria belonging to 17 genera and 34 species were detected. Escherichia coli were the most frequently (39) isolated followed by Citrobacter freundii (33), Klebsiella pneumonia (27), Salmonella indica (12), Enterobacter gergoviae (12), and Ent. agglomerans (11). Other important bacteria isolated from gecko droppings were Listonella damsela (2), Raoultella terrigena (3), S. salamae (2), S. houtenae (3), Edwardsiella tarda (4), Edwardsiella hoshinae (1), and Klebsiella oxytoca (2). Of the 223 isolates tested for antimicrobial drug sensitivity, 27 (12.1%) had multiple drug resistance (MDR). None of the salmonellae or edwardsiellae had MDR however, MDR strains were significantly more common among Escherichia spp. ( ) and isolates from IFS units ( ). The most effective herbal drug, Ageratum conyzoides extract, inhibited growth of only 27.8% of strains tested followed by ethanolic extract of Zanthoxylum rhetsa (13.9%), eucalyptus oil (5.4%), patchouli oil (5.4%), lemongrass oil (3.6%), and sandalwood oil (3.1%), and Artemisia vulgaris essential oil (3.1%). 1. Introduction In most parts of the world house wall lizards are common. In the Jharnapani area, common house gecko (Hemidactylus frenatus) is found everywhere in houses, in animal sheds, in offices, and so forth. Geckos are often reported as carriers of many zoonotic enteropathogens including nontyphoidal salmonellae [1–5], Citrobacter freundii, C. Intermedius, Erwinia herbicola, Enterobacter cloacae [2, 5], Shigella sonnei, Edwardsiella tarda, Enterobacter species, Serratia marcescens, Proteus spp., Klebsiella pneumonia, and Escherichia coli [5]. Researchers have suspected that lizards have a role as reservoirs in spread and emergence of drug resistant bacteria [2, 4, 5]. However, most of the studies on enteropathogens of public health significance in lizards have been conducted through collecting lizards, euthanizing them, and then collecting their intestinal contents, determining the presence of bacteria. Enteric diseases often spread through contamination of environment with the faeces of patients loaded with the pathogens. Insects often try to scavenge on patients’ excreta, and those insects that are eaten by house geckos may be sources of different pathogens in lizard intestine and may be detected in lizards’ intestine [2, 5]. The question we asked was what
A genetic algorithm based approach for optimal allocation of distributed generations in power systems for voltage sensitive loads
Raj Kumar Singh,S.K. Goswami
Journal of Engineering and Applied Sciences , 2009,
Abstract: Connecting green power sources to power grid are gradually becoming popular. Proper placement and sizing of these energy sources is important in order to obtain their maximum potential benefits. There have been studies to allocate the DG, in which loads are generally modeled as constant power or constant current types of loads. Since most of the distribution system loads are uncontrolled and dependent on the voltage and frequency of the system. Accordingly in this study a methodology has been presented that uses genetic algorithm to optimally place the DGs in terms of locations and sizes so as to minimize the per unit locational charges for active power at buses by incorporating different voltage dependent static load models. The presence of DG sources at distribution level has changed the characteristics of distribution network from passive to active. Nodal pricing and per unit locational charges often used in the pricing of short-term operation in transmission are good candidates to consider in distribution. Several simulation studies have been conducted on radial feeder as well as networked systems with single DG and multiple DG separately, subjected to no voltage violation at any of the buses.
EFFECT OF PRESSURE INDUCED GRAFT COPOLYMERIZATION ON THE PHYSICO-CHEMICAL PROPERTIES OF BIO-FIBERS
Amar Singh Singha,Raj K. Rana
BioResources , 2010,
Abstract: The present study deals with the surface modification of Agave americana L. fiber through graft copolymerization of methyl methacrylate under pressure in the presence of ceric ammonium nitrate as redox initiator. The various reaction parameters such as reaction time, pressure, concentration of nitric acid, initiator, and monomer, etc. were optimized to have the maximum graft yield of 13.6%. The grafted fibers were then subjected to the evaluation of different physico-chemical properties such as swelling behavior, solubility, moisture absorption under different humidity levels, resistance to acids and bases, etc. It was observed that swelling behavior, solubility behavior, and moisture absorbance decreased with increase in grafting, whereas resistance to acids and bases increased with grafting. The fibers grafted under the optimized conditions were then characterized by Fourier transform infra-red spectroscopy, scanning electron microscopy, thermogravimetric analysis, and x-ray diffraction techniques.
Unification scheme of radio galaxies and quasars falsified by their observed size distributions
Ashok K. Singal,Raj Laxmi Singh
Physics , 2013, DOI: 10.1088/0004-637X/766/1/37
Abstract: In the currently popular orientation-based unified scheme, a radio galaxy appears as a quasar when its principal radio-axis happens to be oriented within a certain cone opening angle around the observer's line of sight. Due to geometrical projection, the observed sizes of quasars should therefore appear smaller than those of radio galaxies. We show that this simple, unambiguous prediction of the unified scheme is not borne out by the actually observed angular sizes of radio galaxies and quasars. Except in the original 3CR sample, based on which the unified scheme was proposed, in other much larger samples no statistically significant difference is apparent in the size distributions of radio galaxies and quasars. The population of low-excitation radio galaxies with apparently no hidden quasars inside, which might explain the observed excess number of radio galaxies at low redshifts, cannot still account for the absence of any foreshortening of the sizes of quasars at large redshifts. On the other hand from infrared and X-ray studies there is evidence of hidden quasar within a dusty torus in many RGs, at $z>0.5$. It seems difficult how to reconcile this with the absence of foreshortening of quasar sizes at even these redshifts, and perhaps one has to allow that the major radio axis may not have anything to do with the optical axis of the torus. Otherwise to resolve the dichotomy of radio galaxies and quasars, a scheme quite different from the present might be required.
Incongruity of the unified scheme with a 3CRR-like equatorial strong-source sample
Ashok K. Singal,Raj Laxmi Singh
Physics , 2013, DOI: 10.1093/mnrasl/slt091
Abstract: We examine the consistency of the unified scheme of the powerful extragalactic radio sources with the 408 MHz BRL sample from the equatorial sky region, selected at the same flux-density level as the 3CRR sample. We find that, unlike in the 3CRR sample, a foreshortening in the observed sizes of quasars, expected from the orientation-based unified scheme model, is not seen in the BRL sample, at least in different redshift bins up to z~1. Even the quasar fraction in individual redshift bins up to z~1 does not match with that expected from the unified scheme, where radio galaxies and quasars are supposed to belong to a common parent population at all redshifts. This not only casts strong doubts on the unified scheme, but also throws up an intriguing result that in a sample selected from the equatorial sky region, using almost the same criteria as in the 3CRR sample from the northern hemisphere, the relative distribution of radio galaxies and quasars differs qualitatively from the 3CRR sample.
Vibrational and Quantum Chemical Study of Triphenylantimony(V)-o-salicylate
Tanveer Hasan,P. K. Singh,P. Raj,K. Singhal
Journal of Chemistry , 2008, DOI: 10.1155/2008/351845
Abstract:
New Voltage Mode Universal Filters Using Only Two CDBAs
J. K. Pathak,A. K. Singh,Raj Senani
ISRN Electronics , 2013, DOI: 10.1155/2013/987867
Abstract:
New Voltage Mode Universal Filters Using Only Two CDBAs
J. K. Pathak,A. K. Singh,Raj Senani
ISRN Electronics , 2013, DOI: 10.1155/2013/987867
Abstract: Two new configurations for voltage mode universal filters (VMUFs) using only two current differencing buffered amplifiers (CDBAs) are proposed. Both of the new configurations can realize all the five standard types of the filters, namely, low pass (LP), high pass (HP), band pass (BP), band stop (BS), and all pass (AP), from the same topology. In contrast to previously known CDBA-based VMUFs, the new configurations do not need an additional active device for voltage inversion to realize all pass functions. The proposed configurations offer the tunability of the natural angular frequency , quality factor , or the bandwidth (BW) through separate virtually grounded resistors. Moreover, both circuits have resistive input impedance (which can be made high) and a low output impedance to facilitate easy cascading without additional buffers. PSPICE simulation results, based upon commercially available AD844 ICs to implement the CDBA, are included which confirm the practical workability of the new VMUF configurations. 1. Introduction Analog filters are widely used for continuous-time signal processing in communication, measurement, instrumentation, and control systems [1]. Universal biquadratic filters are particularly attractive since they can realize all the five standard types of the filters, namely, low pass (LP), high pass (HP), band pass (BP), band stop (BS), and all pass (AP), from the same topology. Whereas universal voltage mode filters using current conveyors (CCs) or current feedback operational amplifiers (CFOAs) have received considerable attention in the technical literature, many of the reported circuits suffer from the drawbacks of requiring a large number of active and/or passive components and/or nonavailability of tuning of filter parameters [2]. Traditionally, the analog signal processing operations have been accomplished employing the voltage as signal variable. On the other hand, it has also been recognized that current mode circuits can achieve significant improvement in bandwidth, simplification of circuitry, power consumption, and dynamic range [3]. In order to maintain compatibility with existing voltage processing circuits as well as taking advantages of current mode circuits, a new active element called current differencing buffered amplifier (CDBA) was introduced in [4]. CDBA is suitable for IC implementation in both bipolar and CMOS technologies [4, 5]. Since a CDBA operates in both current mode and voltage mode, along with current differencing feature, CDBA has been shown to offer a lot of flexibility in circuit design; for
Decay analysis of compound nuclei with mass A$\sim 30-200$ formed in the reactions involving loosely bound projectiles
Mandeep Kaur,BirBikram Singh,Manoj K. Sharma,Raj K. Gupta
Physics , 2015, DOI: 10.1103/PhysRevC.92.024623
Abstract: The dynamics of the reactions forming compound nuclei using loosely bound projectiles is analysed within the framework of dynamical cluster decay model (DCM) of Gupta and Collaborators. We have analysed different reactions with $^{7}Li$, $^{9}Be$ and $^{7}Be$ as neutron rich and neutron deficient projectiles, respectively, on different targets at the three $E_{lab}$ values, forming compound nuclei within the mass region A$\sim 30-200$. The contributions of light particles LPs ($A\le4$) cross sections $\sigma_{LP}$, energetically favoured intermediate mass fragments IMFs ($5 \le A_2 \le 20$) cross sections $\sigma_{IMF}$ as well as fusion-fission $\it{ff}$ cross sections $\sigma_{ff}$ constitute the $\sigma_{fus}$ (=$\sigma_{LP}$+$\sigma_{IMF}$+$\sigma_{ff}$) for these reactions. The contribution of the emitted LPs, IMFs and ff fragments is added for all the angular momentum upto the $\ell_{max}$ value, for the resepctive reactions. Interestingly, we find that the $\Delta R^{emp}$, the only parameter of model and uniquely fixed to address the $\sigma_{fus}$ for all other reactions having $\it same$ loosely bound projectile at the chosen incident energy. It may be noted that the dynamical collective mass motion of preformed LPs, IMFs and ff fragments or clusters through the modified interaction potential barrier are treated on parallel footing. We see that the values of modified interaction barrier heights $\Delta V_{B}^{emp}$ for such reactions are almost of the same amount specifically at the respective $\ell_{max}$ values.
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