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91.
Rosner JL Adam NE Alexander JP Berkelman K Cassel DG Duboscq JE Ecklund KM Ehrlich R Fields L Gibbons L Gray R Gray SW Hartill DL Heltsley BK Hertz D Jones CD Kandaswamy J Kreinick DL Kuznetsov VE Mahlke-Krüger H Meyer TO Onyisi PU Patterson JR Peterson D Phillips EA Pivarski J Riley D Ryd A Sadoff AJ Schwarthoff H Shi X Stroiney S Sun WM Wilksen T Weinberger M Athar SB Avery P Breva-Newell L Patel R Potlia V Stoeck H Yelton J Rubin P Cawlfield C Eisenstein BI Karliner I Kim D Lowrey N Naik P 《Physical review letters》2006,96(12):121801
We present the first experimental limits on high-q2 contributions to charmless semileptonic decays of the form expected from the weak annihilation (WA) decay mechanism. Such contributions could bias determinations of /Vub/ from inclusive measurements of B-->Xulupsilon. Using a wide range of models based on available theoretical input we set a limit of GammaWA/Gammab-->u<7.4% (90% confidence level) on the WA fraction, and assess the impact on previous inclusive determinations of /Vub/. 相似文献
92.
S. Dechoudhury Vaishali Naik Manas Mondal Hemendra Kumar Pandey Avik Chatterjee Dirtha Sanyal Debasis Bhowmick Alok Chakrabarti 《Pramana》2010,75(3):485-499
The design of a medium energy beam transport (MEBT) line comprising of a re-buncher and four quadrupoles, two upstream and
the other two downstream of the re-buncher, has been presented. The design was done to ensure almost 100% transport of heavy-ion
beams of about 99 keV/u energy from RFQ having a q/A not less than 1/14 through the re-buncher and then through IH Linac of about 0.6 m length in which beam would be accelerated
to about 185 keV/u. The re-buncher has been designed to operate at 37.8 MHz, the resonating frequency of both the RFQ and
the IH Linac. The entire beam line has been installed and recently O5+ beam from RFQ has been transported through the re-buncher and subsequently accelerated in the IH Linac successfully. 相似文献
93.
A.S. Joshi P.A. Naik S. Barnwal Y.B.S.R. Prasad P.D. Gupta 《Optics Communications》2010,283(23):4713-763
Diagnostic information about the self-generated magnetic fields (SGMF) generated in laser produced plasmas is normally obtained by measuring the Faraday rotation angle (FRA) of a linearly polarized laser probe beam passing through the plasma. Simultaneous recording of the corresponding interferogram is required to get the density information necessary for estimating the magnetic field. The problem with this method is that the visibility of the fringes in the interferogram can be poor, and the SGMF cannot be calculated in the regions where the interference fringes are not observable. In this paper, we propose a new method to obtain the density distribution and the SGMF from two simultaneous measurements of FRA using two probe beams of different colors, which allows one to calculate the SGMF without the need of interferometry. 相似文献
94.
Sachin R. Shirsath Anup P. Patil Rohit Patil Jitendra B. Naik Parag R. Gogate Shirish H. Sonawane 《Ultrasonics sonochemistry》2013,20(3):914-923
The present work deals with the removal of Brilliant Green dye from wastewater using a poly(acrylic acid) hydrogel composite (PAA-K hydrogel) prepared by incorporation of kaoline clay. The composite has been synthesized using ultrasound assisted polymerization process as well as the conventional process, with an objective of showing the better effectiveness of ultrasound assisted synthesis. It has been observed that the hydrogel prepared by ultrasound assisted polymerization process showed better results. The optimum conditions for the removal of dye are pH of 7, temperature of 35 °C, initial dye concentration of 30 mg/L and hydrogel loading of 1 g. The extent of removal of dye increased with an increase in the contact time and initial dye concentration. A pseudo-second-order kinetic model has been developed to explain the adsorption kinetics of dye on the PAA-K hydrogel. Thermodynamic and kinetic parameters indicate that the adsorption process is spontaneous in nature and the PAA-K hydrogel prepared by ultrasound process is a promising adsorbent compared to conventional process. The obtained adsorption data has also been fitted into commonly used adsorption isotherms and it has been found that Freundlich as well as Langmuir adsorption isotherm models fits well to the experimental results. 相似文献
95.
An efficient and environmentally friendly multicomponent synthesis of substituted 1,8-naphthyridines catalyzed by bismuth(III) nitrate pentahydrate [Bi(NO(3))(3) . 5H(2)O] under solvent-free microwave irradiation is described. This procedure has such advantages as short reaction time, high yields, and simple workup. The catalyst could be reused several times, keeping its initial activity recycled reactions. 相似文献
96.
We present here design and synthesis of very efficient, high‐yielded and simple approach of a series of C4‐linked coumarin–hypoxanthine pharmacophores 1 ( a–j ) with moderate to excellent in vitro antimicrobial activity. According to earlier studies, potential modification at C4‐position of coumarin ring provided excellent bioactive molecules. All the titled compounds were characterized by spectroscopic and elemental analyses. Titled compounds have been developed via systematic tuning of coumarin ring substitutions, which are prepared from the well‐known Pechmann condensation reaction. The addition of a pendent nucleobase in hypoxanthine group improved the in vitro antimicrobial activity. Computational studies were also mimicking the potent biomolecules. A good pharmacokinetic profile is suggested by theoretical calculation of absorption, distribution, metabolism, and excretion properties. Therefore, synthesis of these titled compounds provided an insight towards better antimicrobial agents. 相似文献
97.
Vikash Kumar Viraj G. Naik Avijit Das Sourayan Basu Bal Malabika Biswas Nupur Kumar Anasuya Ganguly Amrita Chatterjee Mainak Banerjee 《Tetrahedron》2019,75(27):3722-3732
Available online Development of water soluble AIE-active “light-up” bioprobes for the detection of biomacromolecules has drawn huge research interests in recent past. In this study, a series of ethylene glycol modified water soluble tetrameric tetraphenylethylene amphiphiles with pyridinium polar heads (TPE-xEG-Py, x = 3, 4, 6 or 1a-c) have been synthesized by varying the ethylene glycol spacer. Their unique structure allows them to form vesicles and other nanoaggregates in aqueous solutions. These amphiphiles were successfully utilized for fluorimetric detection and quantitation of BSA and DNA based on the electrostatic interactions to trigger AIE-emission from the TPE moiety. The electrostatic interaction was also proved very effective in wash-free imaging of both Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria with up to 92 folds increase in fluorescence response within bacterial concentration 0–12 × 108 CFU mL?1. The strategy is advantageous due to cost-effective and easy synthesis, high water solubility, and fast response. 相似文献
98.
Comparative studies on radiolytic degradation of deuterium labeled and unlabeled tributyl phosphates
Shikha Sharma Sunil K. Ghosh Devidas B. Naik Prem S. Dhami Joti N. Sharma 《Journal of Radioanalytical and Nuclear Chemistry》2014,302(1):583-591
Deuterium labeled tributyl phosphates were synthesized and their solutions in n-dodecane have been investigated for γ-radiolytic degradation up to an absorbed dose of 2,000 kGy from a 60Co source. The performance was compared with undeuterated TBP. Radiolysis extent and pattern of formation of major degradation products, viz. dibutyl hydrogen phosphate and monobutyl dihydrogen phosphate were found to be very similar from deuterated or undeuterated samples. Extraction behavior for UO2 2+ and Pu(IV) was studied after the radiolysis, and the results showed similarity in extraction/stripping behavior for all labeled or unlabeled TBP samples. The isotope effect (k H/k D) observed is minimal in this γ-radiolytic degradation study. 相似文献
99.
S. Barnwal Y. B. S. R. Prasad S. Nigam K. Aneesh M. L. Sharma R. P. Kushwaha P. K. Tripathi P. A. Naik J. A. Chakera C. P. Navathe P. D. Gupta 《Applied physics. B, Lasers and optics》2014,117(1):131-139
Intense lasing had been obtained from argon plasma in the soft X-ray region from a capillary discharge plasma system. Different diagnostics have been used to characterize the lasing properties by recording the temporal, spatial, and spectral profiles of the emission. The divergence measurement indicates that the soft X-ray laser beam has good directionality with a divergence of 3.5 mrad. The spectrum of the laser beam measured using a transmission grating showed intense lasing line at 46.9 nm. Diffraction orders as high as 10th orders were observed. The temporal profile recorded with a vacuum diode showed a distinct laser peak with a pulse width ~1.2 ns (FWHM). In addition, the coherence of the X-ray laser beam was also confirmed from the high-contrast interference fringes (visibility ~85 %) recorded using double slits. 相似文献
100.
Chelsea C. Buck Patrick B. Dennis Maneesh K. Gupta Marcus T. Grant Marquise G. Crosby Joseph M. Slocik Peter A. Mirau Kellie A. Becknell Kristen K. Comfort Rajesh R. Naik 《Macromolecular bioscience》2019,19(3)
The suckerin family of proteins, identified from the squid sucker ring teeth assembly, offers unique mechanical properties and potential advantages over other natural biomaterials. In this study, a small suckerin isoform, suckerin‐12, is used to create enzymatically crosslinked, macro‐scale hydrogels. Upon exposure to specific salt conditions, suckerin‐12 hydrogels contracted into a condensed state where mechanical properties are found to be modulated by the salt anion present. The rate of contraction is found to correlate well with the kosmotropic arm of the Hofmeister anion series. However, the observed changes in hydrogel mechanical properties are better explained by the ability of the salt to neutralize charges in suckerin‐12 by deprotonization or charge screening. Thus, by altering the anions in the condensing salt solution, it is possible to tune the mechanical properties of suckerin‐12 hydrogels. The potential for suckerins to add new properties to materials based on naturally‐derived proteins is highlighted. 相似文献