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21.
M. Sweany A. BernsteinS. Dazeley J. Dunmore J. FeldeR. Svoboda M. Tripathi 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2012,664(1):245-250
Cherenkov detectors employ various methods to maximize light collection at the photomultiplier tubes (PMTs). These generally involve the use of highly reflective materials lining the interior of the detector, reflective materials around the PMTs, or wavelength-shifting sheets around the PMTs. Recently, the use of water-soluble wavelength-shifters has been explored to increase the measurable light yield of Cherenkov radiation in water. These wave-shifting chemicals are capable of absorbing light in the ultraviolet and re-emitting the light in a range detectable by PMTs. Using a 250 L water Cherenkov detector, we have characterized the increase in light yield from three compounds in water: 4-Methylumbelliferone, Carbostyril-124, and Amino-G Salt. We report the gain in PMT response at a concentration of 1 ppm as 1.88±0.02 for 4-Methylumbelliferone, stable within 0.5% over 50 days, 1.37±0.03 for Carbostyril-124, and 1.20±0.02 for Amino-G Salt. The response of 4-Methylumbelliferone was modeled, resulting in a simulated gain within 9% of the experimental gain at 1 ppm concentration. Finally, we report an increase in neutron detection performance of a large-scale (3.5 kL) gadolinium-doped water Cherenkov detector at a 4-Methylumbelliferone concentration of 1 ppm. 相似文献
22.
Rajender Singh Malik Sandeep Nath Tripathi Deeksha Gupta Veena Choudhary 《International Journal of Hydrogen Energy》2014
Novel composite membranes were prepared using imidazolium type aprotic ionic liquids and sulfonated poly (ether ketone) (SPEK) as polymer matrix by solution casting process. All the prepared membranes were characterized for their thermal stability, mechanical properties, ion exchange capacity, proton conductivity and leaching out of ionic liquids in presence of water. Ionic liquid based membranes were more flexible than neat SPEK membrane due to the plasticization effect of ionic liquids. The interactions and compatibility occurring among components were investigated by vibration spectroscopy (FTIR ATR) and scanning electron microscopy respectively. The thermal stability of composite membranes was higher than unmodified membranes. The ion conductivity of composite membranes under anhydrous conditions was found to be dependent on temperature, type and concentration of ionic liquid in SPEK matrix. Ion conductivities of composite membranes under anhydrous condition were found to be up to two orders (∼100 times) higher than neat SPEK membrane and it was found to be ∼5 mS/cm at 140 °C for SPEK/OTf-70. These composite membranes can be successfully operated at temperatures ranging from 40 °C to 140 °C under anhydrous conditions. 相似文献
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24.
Abhishek Kumar Tripathi Sudipta Mukhopadhyay 《Signal, Image and Video Processing》2014,8(8):1431-1439
In this paper, a framework of real-time video processing for fog removal using uncalibrated single camera system is proposed. Intelligent use of temporal redundancy present in video frames paves the way for real-time implementation. Any fog removal algorithm for images acquired with uncalibrated single camera system can be extended to video using the proposed framework. For the purpose of real-time implementation, several fog removal algorithms for images are investigated and few top ranking algorithms in speed and quality are chosen. Simulation results confirm that proposed framework reduces the computation per frame significantly. Proposed fog removal framework has a wide application in navigation, transportation, and other industries. 相似文献
25.
Exploration of a Library of 3,4‐(Methylenedioxy)aniline‐Derived Semicarbazones as Dual Inhibitors of Monoamine Oxidase and Acetylcholinesterase: Design,Synthesis, and Evaluation 下载免费PDF全文
A library of 3,4‐(methylenedioxy)aniline‐derived semicarbazones was designed, synthesized, and evaluated as monoamine oxidase (MAO) and acetylcholinesterase (AChE) inhibitors for the treatment of neurodegenerative diseases. Most of the new compounds selectively inhibited MAO‐B and AChE, with IC50 values in the micro‐ or nanomolar ranges. Compound 16 , 1‐(2,6‐dichlorobenzylidene)‐4‐(benzo[1,3]dioxol‐5‐yl)semicarbazide presented a balanced multifunctional profile of MAO‐A (IC50=4.52±0.032 μm ), MAO‐B (IC50=0.059±0.002 μm ), and AChE (IC50=0.0087±0.0002 μm ) inhibition without neurotoxicity. Kinetic studies revealed that compound 16 exhibits competitive and reversible inhibition against MAO‐A and MAO‐B, and mixed‐type inhibition against AChE. Molecular docking studies further revealed insight into the possible interactions within the enzyme–inhibitor complexes. The most active compounds were found to interact with the enzymes through hydrogen bonding and hydrophobic interactions. Additionally, in silico molecular properties and ADME properties of the synthesized compounds were calculated to explore their drug‐like characteristics. 相似文献
26.
Thin films of CdSe and silver(Ag)-doped CdSe have been prepared on glass substrates by thermal evaporation in argon gas atmosphere. X-ray diffraction pattern indicates the presence of hexagonal structure with preferred orientation along (100) plane. Elemental composition of the thin films has been analyzed using energy dispersive X-ray analysis. Scanning electron microscopy has been used to investigate the morphology of the thin films. Transmission electron microscope reveals spherical nature of nanoparticles. A decrease in the band gap due to the formation of band tails in the band gap with increase in Ag doping in CdSe lattice has been observed. Photoluminescence spectra indicate redshift in band edge emission peak with increase in Ag doping in CdSe. Electrical conductivity measurements are also studied, and two types of conduction mechanisms taking part in the transport phenomena are observed. Hall measurements indicate n-type behavior of undoped and Ag-doped CdSe thin films. 相似文献
27.
Silicon - Accumulation of trap charges at the semiconductor and oxide interface is the most dominating factor and cannot be neglected as it degrades device performance and reliability. This... 相似文献
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PLA/functionalized‐gum arabic based bionanocomposite films for high gas barrier applications 下载免费PDF全文
The present work focuses on the microwave synthesis of lactic acid‐grafted‐gum arabic (LA‐g‐GA) by polycondensation reaction and its influence as an additive to improve the gas barrier properties of poly(lactic acid) (PLA) films, prepared by solution casting method. It is observed that during the synthesis of LA‐g‐GA, hydrophilic gum is converted into hydrophobic due to grafting of in situ grown hydrophobic oligo‐(lactic acid). Subsequently, PLA/LA‐g‐GA bionanocomposite films are fabricated and characterized for structural, thermal, mechanical and gas barrier properties. Path breaking reduction in oxygen permeability (OP) of ~10 folds is achieved in case of PLA films containing LA‐g‐GA as filler. However, water vapor transmission rate (WVTR) is reduced up to 27% after 5 wt % addition of filler. Reduction in OP of this order of magnitude enables the PLA to compete with PET in term of enhancing shelf life and maintaining the food quality. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43458. 相似文献
30.
Synchronization of processes is one of the major performance bottlenecks in a distributed system. The synchronization is usually achieved via message passing. There are two basic types of overhead in such a synchronization: the rate of message exchange, and the blocking probabilities of processes. In this paper we consider two processes synchronizing via message passing and study their performance behavior on the basis of the above-mentioned overheads. A number of protocols for message exchange are analyzed. The model gives rise to a three-dimensional Markov chain. An algorithm to solve the model and numerical results are presented to compare the various protocols. 相似文献