A Different Approach to $f(R)$-Cosmology (2008)
Here $f(R)$-cosmology is discussed using a different approach. This model explains early-inflation, emergence of cosmic background radiation at the exit from inflation, cosmic deceleration during...
$f(R)$-Cosmolgy from Early Universe Upto Future Cosmic Collapse and its Avoidance (2008)
In the present model, a unified picture of cosmology from early inflation to late acceleration is obtained from $ f(R)-$ gravity with non-linear terms $ R^2 $ and $ R^5 $ of scalar curvature $R$. It...
Here, cosmology is obtained from the variable gravitational constant $ G \propto \phi^{-2}$ with $ \phi(x) $ being a scalar and its fluctuations around the ground state. The gravitational action...
Here, cosmology of the late and future universe is obtained from $f(R)$-gravity with non-linear curvature terms $R^2$ and $R^3$ ($R$ being the Ricci scalar curvature). It is different from...
Non-linear Equation of State, COSMIC Acceleration and Deceleration During Phantom-Dominance (2007)
Here, RS-II model of brane-gravity is considerd for phantom universe using non-linear equation of stste. Phantom fluid is known to violate the weak energy condition. In this paper, it is found that...
Can Phantom-Dominated Universe Decelerate Also in Future ? (2007)
Here Randall-Sundrum brane-gravity models of the homogeneous and flat universe, dominated by phantom fluid, is considered. It is noted that brane-gravity corrections effect the behaviour of phantom...
Curvature Inspired Cosmological Scenario (2007)
Using modified gravity with non-linear terms of curvature, $R^2$ and $R^{(r +2)}$ (with $r$ being the positive real number and $R$ being the scalar curvature), cosmological scenario,beginning at the...
Riccion as a Cosmic Cold Dark Matter Candidate and late cosmic acceleration (2006)
Srivastava, S. K., Sinha, K. P.
In the past few years, a possibility is investigated, where curvature itself behaves as a source of dark energy. So, it is natural to think whether curvature can produce dark matter too. It is found...
Here, it is found that dark energy and dark matter emerge from the gravitational sector, if non-linear term of scalar curvature is added to Einstein-Hilbert lagrangian. An equation of state for dark...
Gravitational Origin of Phantom Dark Energy and Late Cosmic Acceleration (2006)
In this letter, dark energy is obtained using dual roles of the Ricci scalar (as a physical field as well as geometry). Dark energy density, obtained here, mimics phantom and the derived Friedmann...
Early and Late Transient Cosmic Acceleration due to Curvature Inspired Dark Energy (2006)
It is obtained that dark energy emerges from higher-derivative gravity with anon-linear terms proportional to $R^2$ and $R^3$ with $R$ being the Ricci scalar curvature. Interestingly, it is found...
In the present paper, it is found that dark energy emerges spontaneously from the modified gravity. According to cosmological scenario, obtained here, the universe inflates for $\sim 10^{-37}$ sec....
Quintessence Dark Energy Inspired by Dual Role of the Ricci Scalar (2005)
In this letter, it is obtained using dual role of the Ricci scalar (physical as well as geometrical role of the Ricci scalar curvature) in a natural way without any input in the theory for it. In...
Dual Nature of the Ricci Scalar and its Certain Consequences (2005)
Ricci scalar is the key ingredient of non-Newtonian theory of gravity, where space-time geometry has a crucial role. Normally, it is supposed to be a geometrical field, but interestingly it also...
In earlier papers, it is found that the Ricci scalar behaves in dual manner (i) like a matter field and (ii) like a geometrical field. Using dual role of the Ricci scalar, inhomogeneous cosmological...
Test of the hypothesis of transient molten state diffusion for swift-heavy-ion induced mixing (2005)
Srivastava,S. K.., Avasthi,D. K., Assmann,W., Wang,Z. G., Kucal,H., Jaquet,E., ...
Srivastava,S. K., Weissler,G. L.
Lowering of the ionization potentials of hydrogen and carbon atoms immersed in a high temperature and high density thermal plasma generated in a Maecker-type wall stabilized arc have been estimated...
Test of the hypothesis of transient molten state diffusion for swift-heavy-ion induced mixing (2005)
Srivastava, S. K.., Avasthi, D. K., Assmann, W., Wang, Z. G., Kucal, H., Jaquet, E., ...
Quantum driven Bounce of the future Universe (2004)
It is demonstrated that due to back-reaction of quantum effects, expansion of the universe stops at its maximum and takes a turnaround. Later on, it contracts to a very small size in finite future...
Mass Spectrometric Study of Sulfur Vapor (2004)
It is well known that sulfur catenates and forms oligmers ranging from S2 to S20. The actual number of species present in the vapor depends on several factors and has been the subject of many studies...
Electron Impact Ionization and Dissociative Ionization of C2H2 (2004)
By utilizing a crossed electron beam collision geometry, a combination of time-of-flight (TOF) and quadrupole mass spectrometers, and the relative flow technique1 normalized values of cross sections...
Cross Sections for the Formation of Negative Ions by Electron (2004)
Cross sections, appearance energies, and energies at which
Ionization Cross Sections of Silane and Disilane by Electron Impact (2004)
Krishnakumar, E., Srivastava, S. K.
Partial ionization cross sections for silane and disilane have
Ionization cross-sections for the production of positive ions from H2O by electron impact (2004)
Water is present in the atmospheres of 6 of the 9 planets. Cross section values for the direct and partial ionization of H2O by electron impact have been measured and compared with previously...
Cross sections for the production of energetic cations by electron impact on N2 and CO2 (2004)
Iga, I., Srivastava, S. K., Katayama, D. H.
Dissociative ionization cross sections for the production of singly charged energetic ions by electron impact on N2 and CO2 have been measured. The ions were divided into two groups: one with...
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Electron-Impact Ionization of Mg (2004)
Boivin, R. F., Srivastava, S. K.
A pulsed crossed beam technique is used to measure inonization cross-sections of metallic atoms. Relative values of cross-sections of single, double and triple inonization of magnesium have been...
Non-violation of Energy Conditions in the future accelerated universe due to quantum effects (2004)
Here, an accelerated phantom model for the late universe is explored, which is free from future singularity. It is interseting to see that this model exhibits strong curvature for all time in future,...
Tachyon as a Dark Energy Source (2004)
It is demonstrated that dark energy, driven by tachyons having non-minimal coupling with curvature and self-interacting inverse cubic potential, decays to cold dark matter in the late universe. It is...
Future Universe With w < -1 Without Big Smash (2004)
It is demonstrated that if cosmic dark energy behaves like a fluid with equation of state $p = {\rm w} \rho (p$ and $\rho$ being pressure and energy density respectively) as well as generalized...
Dark Energy and dark matter of the universe from one-loop renormalization of riccion (2004)
Here, creation of the universe is obtained only from gravity sector. The dynamical universe begins with two basic ingredients (i) vacuum energy, also called dark energy (as vacuum energy is not...
Srivastava,S. K., Plachke,D., Szökefalvi-Nagy,A., Major,J., Carstanjen,H. D.
The paper reports about recent experiments on HOPG (highly oriented pyrolytic graphite) by high-resolution RBS (Rutherford backscattering spectroscopy). By using an ion beam of 1 MeV N+ up to 7...
Swift heavy ion induced modification of Si/C60 multilayers (2004)
Srivastava,S. K., Kabiraj,D., Schattat,B., Carstanjen,H. D., Avasthi,D. K.
Srivastava, S. K., Plachke, D., Szökefalvi-Nagy, A., Major, J., Carstanjen, H. D.
The paper reports about recent experiments on HOPG (highly oriented pyrolytic graphite) by high-resolution RBS (Rutherford backscattering spectroscopy). By using an ion beam of 1 MeV N+ up to 7...
Swift heavy ion induced modification of Si/C60 multilayers (2004)
Srivastava, S. K., Kabiraj, D., Schattat, B., Carstanjen, H. D., Avasthi, D. K.
Mixing in Cu/Ge system by swift heavy ions (2003)
Kumar,S., Chauhan,R. S., Singh,R. P., Kabiraj,D., Sahoo,P. K., Rumbolz,C., ...
Electronic sputtering from HOPG: A study of angular dependence (2003)
Tripathi,A., Khan,S. A., Srivastava,S. K., Kumar,M., Kumar,S., ...
Mixing in Cu/Ge system by swift heavy ions (2003)
Kumar, S., Chauhan, R. S., Singh, R. P., Kabiraj, D., Sahoo, P. K., Rumbolz, C., ...
Electronic sputtering from HOPG: A study of angular dependence (2003)
Tripathi, A., Khan, S. A., Srivastava, S. K., Kumar, M., Kumar, S., ...
RADARSAT-1 Image Quality Excellence in the Extended Mission (1998)
Srivastava, S. K., Cote, S., Le Dantec, P., Hawkins, R. K.
RADARSAT-1, the first Canadian SAR remote sensing satellite, continues to provide calibrated data to worldwide users since the start of its routine operation on April 1, 1996, more than 9 years after...
The Ni2 (Mo, Cr) Ordering Transformation in a Ni-Mo-Cr Alloy. (1998)
Srivastava, S. K., Lewis, B. E.
The ordering transformations have been studied in Haynes 242 alloy (Ni-25Mo-8Cr). Homogeneous superlattice domains providing strength and stability are formed with the standard heat treatment....
A Low-Thermal Expansion, High Strength Ni-Mo-Cr Alloy for Gas Turbines. (1998)
A recently developed nickel alloy for gas-turbine applications, Haynes 242, has been evaluated. Microstructure, tensile properties (RT, 650 C, 760 C) as a function of aging for various times, and...
Oxidation of Gas Turbine Seal Ring Alloys and its Effect on Mechanical Properties. (1998)
Barnes, J. J., Srivastava, S. K.
Haynes 242 Ni alloy and Incoloy 909 were studied to determine the effects of oxidation resistance on their mechanical properties at 650 C and 760 C. Results indicated that Incoloy 909 had poor...
Chelating oin-exchange resin membrane sensor for nicke(11) ions (1996)
Rao, G N, Srivastava, Sandeep, Srivastava, S K, Singh, Mandera
A chalting ion-exchange resin(1hydroxy2 naphthaldoxine-formaldehyde polymer)containing nitrogen and oxgen donor atomas was prepared and characterized.The behave as a selective chelating ion-exchanger...
Worsening Drought Conditions Affect Relay Cropping in Central India (1995)
Chaudhary, J. L., Naidu, D., Srivastava, S. K.
In the Chhattisgarh region of central India (Figure 1), rice is grown on about 3.7 million ha, of which 80% is under rainfed conditions. The rice crop is grown mostly under the broadcast biasi system...
On the existence of tachyons in a bradyon-dominated universe (1985)
In the present paper, the question has been raised as to whether tachyons exist in our universe. The gravitational interaction of tachyons with bradyons is discussed by employing the method of...
Tetsuka, T, Daphna-Iken, D, Srivastava, S K, Baier, L D, DuMaine, J, Morrison, A R
The inflammatory cytokine interleukin 1 beta (IL-1 beta) induces both cyclooxygenase (COX) and nitric oxide synthase (NOS) with increases in the release of prostaglandin (PG) and nitric oxide (NO) by...
Broad-specificity endoribonucleases and mRNA degradation in Escherichia coli.
Srivastava, S K, Cannistraro, V J, Kennell, D
Crude extracts from Escherichia coli were screened for any broad-specificity endoribonuclease after the cell proteins were fractionated by size. In a mutant lacking the gene for RNase I (molecular...
Awasthi, S, Singhal, S S, Srivastava, S K, Zimniak, P, Bajpai, K K, Saxena, M, ...
Previous studies have demonstrated that a human glutathione conjugate transporter, designated as dinitrophenyl-S-glutathione ATPase (DNP-SG ATPase), catalyzed ATP hydrolysis in the presence of...
Srivastava, S K, Di Donato, A, Lacal, J C
We have generated deletion mutants of the H-ras p21 protein which lack residues 58 to 63 or 64 to 68 and contain either the normal glycine or an activating mutation, arginine, at position 12. None of...
Srivastava, S K, Lacal, J C, Reynolds, S H, Aaronson, S A
The high prevalence of ras oncogenes in human tumors has given increasing impetus to efforts aimed at elucidating the structure and function of their p21 products. To identify functionally important...
Identification of the protein encoded by the human diffuse B-cell lymphoma (dbl) oncogene.
Srivastava, S K, Wheelock, R H, Aaronson, S A, Eva, A
The dbl oncogene was initially isolated from a human diffuse B-cell lymphoma. Antisera from mice bearing tumors induced by this oncogene specifically detected a protein of about 66 kDa (p66) in dbl...
Activated and unactivated forms of human erythrocyte aldose reductase.
Srivastava, S K, Hair, G A, Das, B
Aldose reductase (alditol:NADP+ 1-oxidoreductase, EC 1.1.1.21) has been partially purified from human erythrocytes by DEAE-cellulose (DE-52) column chromatography. This enzyme is activated...
Srivastava, S K, Yuasa, Y, Reynolds, S H, Aaronson, S A
ras oncogenes are frequently activated in human tumors by mutations at codon 12 or 61 in their coding sequences. To investigate how these subtle alterations exert such profound effects on the...
Frequency of molecular alterations affecting ras protooncogenes in human urinary tract tumors.
Fujita, J, Srivastava, S K, Kraus, M H, Rhim, J S, Tronick, S R, Aaronson, S A
Members of the ras gene family are activated as oncogenes in many different human cancers. To systematically determine the frequency at which such genes might be involved in the neoplastic process...
Srivastava, S K, Wiktorowicz, J E, Awasthi, Y C
Human kidney hexosaminidase A (beta-N-acetylglucosaminidase; 2-acetamido-2-deoxy-beta-D-glucoside acetamidodeoxyglucohydrolase; EC 3.2.1.30) is a heteropolymer of two immunologically distinct...
Dinitrophenyl glutathione efflux from human erythrocytes is primary active ATP-dependent transport.
LaBelle, E F, Singh, S V, Srivastava, S K, Awasthi, Y C
Dinitrophenyl S-glutathione is accumulated by inside-out vesicles made from human erythrocytes in a process totally dependent on ATP and Mg2+. The vesicles were shown to accumulate dinitrophenyl...
Singh, S V, Dao, D D, Partridge, C A, Theodore, C, Srivastava, S K, Awasthi, Y C
Four immunologically distinct subunits were characterized in glutathione (GSH) S-transferases of human liver. Five cationic enzymes (pI 8.9, 8.5, 8.3, 8.2 and 8.0) have an apparently similar subunit...
Saneto, R P, Awasthi, Y C, Srivastava, S K
We have purified two isoenzymes of glutathione S-transferase from bovine retina to apparent homogeneity through a combination of gel-filtration chromatography, affinity chromatography and isoelectric...
Saneto, R P, Awasthi, Y C, Srivastava, S K
Since the eye is constantly exposed to potentially damaging chemical compounds present in the atmosphere and vascular system, we investigated the physiological role of glutathione S-transferase (GSH...
Purification and properties of human kidney-cortex hexosaminidases A and B.
Wiktorowicz, J E, Awasthi, Y C, Kurosky, A, Srivastava, S K
Hexosaminidases (EC 3.2.1.30) A and B from human kidney cortex were purified to homogeneity by using concanavalin A affinity chromatography, ion-exchange chromatography and gel filtration. The yield...
Purification and properties of glutathione peroxidase from human placenta.
Awasthi, Y C, Dao, D D, Lal, A K, Srivastava, S K
Glutathione peroxidase (glutathione--H2O2 oxidoreductase; EC 1.11.1.9) was purified to homogeneity from human placenta by using (NH4)2SO4 precipitation, ion-exchange chromatography, Sephadex gel...
Srivastava, S, Chandra, A, Ansari, N H, Srivastava, S K, Bhatnagar, A
The aim of this study was to identify the cardiac oxidoreductases involved in the metabolism of 4-hydroxy-2-trans-nonenal (HNE), an alpha,beta unsaturated aldehyde generated during the peroxidation...
Srivastava, S K, Hu, X, Xia, H, Bleicher, R J, Zaren, H A, Orchard, J L, ...
Glutathione (GSH) S-transferases (GSTs) have an important role in the detoxification of (+)-anti-7,8-dihydroxy-9,10-oxy-7,8,9, 10-tetrahydrobenzo[a]pyrene [(+)-anti-BPDE], which is the ultimate...
Structural and kinetic modifications of aldose reductase by S-nitrosothiols.
Srivastava, S, Dixit, B L, Ramana, K V, Chandra, A, Chandra, D, Zacarias, A, ...
Modification of aldose reductase (AR) by the nitrosothiols S-nitroso-N-acetyl penicillamine (SNAP) and N-(beta-glucopyranosyl)-N(2)-acetyl-S-nitrosopenicillamide (glyco-SNAP) resulted in a 3-7-fold...
Studies on the immunogenicity of Streptococcus equi vaccines in foals.
The ability of either formalin-treated or heat-inactivated whole Streptococcus equi cell vaccines or partially purified M-protein of S. equi to give rise to protective antibody levels was studied in...
The serological response of foals to vaccination against strangles.
A group of 100 foals was given either a commercial bacterin or an autogenous vaccine consisting of whole cells and an acid extract of Streptococcus equi. During the study, some of the foals developed...
Lymphocyte stimulation was observed in whole equine blood in the presence of phytohaemagglutinin and M protein extracted from a typical strain of Streptococcus equi. Blood samples were collected from...
Tetsuka, T, Daphna-Iken, D, Srivastava, S K, Baier, L D, DuMaine, J, Morrison, A R
The inflammatory cytokine interleukin 1 beta (IL-1 beta) induces both cyclooxygenase (COX) and nitric oxide synthase (NOS) with increas