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101.
Alex Cao Abhilash K. Pandya Gulay K. Serhatkulu Rachel E. Weber Houbei Dai Jagdish S. Thakur Vaman M. Naik Ratna Naik Gregory W. Auner Raja Rabah D. Carl Freeman 《Journal of Raman spectroscopy : JRS》2007,38(9):1199-1205
This paper introduces a new robust method for the removal of background tissue fluorescence from Raman spectra. Raman spectra consist of noise, fluorescence and Raman scattering. In order to extract the Raman scattering, both noise and background fluorescence must be removed, ideally without human intervention and preserving the original data. We describe the rationale behind our robust background subtraction method, determine the parameters of the method and validate it using a Raman phantom against other methods currently used. We also statistically compare the methods using the residual mean square (RMS) with a fluorescence‐to‐signal (F/S) ratio ranging from 0.1 to 1000. The method, ‘adaptive minmax’, chooses the subtraction method based on the F/S ratio. It uses multiple fits of different orders to maximize each polynomial fit. The results show that the adaptive minmax method was significantly better than any single polynomial fit across all F/S ratios. This method can be implemented as part of a modular automated real‐time diagnostic in vivo Raman system. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
102.
S. Attia L. Hevroni A. Danon D. Meyerstein J. E. Koresh Y. Finkelstein 《Adsorption》2013,19(2-4):821-833
The oxygen isotopic exchange during dehydration and decomposition of five sulfate salt hydrates (CoSO4·6H2O, NiSO4·7H2O, ZnSO4·7H2O, CaSO4·2H2O, Li2SO4·H2O) was studied in detail by temperature programmed desorption mass spectrometry (TPD-MS) in a supersonic molecular beam (SMB) inlet mode. Crystals of the 18O-enriched salts were grown and the detailed desorption steps of the various gaseous products released during dehydration and decomposition of these compounds were recorded. The desorption patterns confirmed the known characteristic stepwise dehydration of these salts, where regardless of the crystalline structure and composition, in all the salts (excluding the Li and Ca sulfates) a major group of n ? 1 loosely bounded water of crystallization molecules (out of total of n molecules in the fully hydrated form) are released at adjacent temperatures in a typical low temperature range (<200 °C), while the last, most strongly bounded water molecule, consistently desorbs at relatively higher temperatures (240 < T < 440 °C). Interestingly, it is established that the oxygen isotopic exchange occurs exclusively between that latter, most strongly bound water molecule, and the salt anion. Remarkably, the results point out that the exchange process is mostly of solid-solid nature. Finally, the results point out that the probability of the isotopic exchange increases with the increment in the desorption temperature of the last dehydration step, i.e. with the bond strength in the monohydrate, between the last water molecule of crystallization and the cation. 相似文献
103.
Ashraf A. El-Shehawy Adel M. E. Attia 《Phosphorus, sulfur, and silicon and the related elements》2013,188(5):1129-1142
4-[(+)-Camphor-10'-sulfonylamino]acetophenone ( 2 ) and some of its chalcones 3 were easily prepared in quantitative yields starting from (+)-camphor-10-sulfonyl chloride. Several new 2-oxo-, 2-thio-, as well as 2-amino-pyridines carrying the camphor sulfonylamino group as a substituent were synthesized easily in one step by Michael addition of several activated nitriles to compounds 2 and 3 . The synthesis of some fused pyridines also was investigated. 相似文献
104.
105.
106.
Sheha R. R. Moussa S. I. Attia M. A. Sadeek S. A. Someda H. H. 《Russian Journal of Applied Chemistry》2018,91(3):483-498
Russian Journal of Applied Chemistry - Magnesium-cadmium hydroxyapatite [(Mg-Cd)HAP] and novel multi-wall carbon nanotubes Mg-Cd hydroxyapatite (CNTs/(Mg-Cd)HAP) composites were synthesized by a... 相似文献
107.
108.
H.A. Attia 《Archive of Applied Mechanics (Ingenieur Archiv)》2006,75(4-5):268-274
The influence of variation in physical variables on the steady magnetohydrodynamic (MHD) Couette flow with heat transfer is
studied. An external uniform magnetic field is applied perpendicular to the parallel plates and the fluid is acted upon by
a constant pressure gradient. The viscosity and the thermal as well as electric conductivities are assumed to be temperature
dependent. The two plates are kept at two constant but different temperatures, and the viscous and Joule dissipations are
considered in the energy equation. A numerical solution for the governing nonlinear coupled equations of motion and the energy
equation is obtained. The effect of the temperature-dependent viscosity, thermal conductivity, and electrical conductivity
on both the velocity and temperature distributions is examined.
H.A. Attia - On leave from: Dept. of Eng. Mathematics and physics, El-Fayoum University, El-Fayoum, Egypt 相似文献
109.
Rabah Benabid Mohamed Boudour Mohammad Ali Abido 《Analog Integrated Circuits and Signal Processing》2011,69(1):91-102
Optimal location, number, and settings of unified power flow controllers (UPFC) using various multi-objective optimization algorithms is presented in this paper. The UPFC parameters, locations and number are computed to maximize the voltage stability margin and minimize the real power losses at the same time. For this, developed hierarchical optimization versions of three recent multi-objective algorithms are proposed namely: non-dominated genetic algorithms (NSGA-II), non-dominated sorting particle swarm optimization (NSPSO) and Strength Pareto Evolutionary Algorithm 2 (SPEA2). The fuzzy logic is proposed to extract the best compromise solution from the Pareto set. The proposed algorithms are applied to IEEE 30-bus power system. The line flow and load bus voltage limits are taken into account. The obtained results show that the installation of the UPFC in the power system minimizes the power losses, enhances the static voltage stability, and improves the voltage profiles. Furthermore, the proposed methods are able to solve a hard discrete?Ccontinuous constrained multi-objective optimization problem. In addition, they do not show any limitation on the number of objective functions under consideration. 相似文献
110.
Touahir L Galopin E Boukherroub R Gouget-Laemmel AC Chazalviel JN Ozanam F Saison O Akjouj A Pennec Y Djafari-Rouhani B Szunerits S 《The Analyst》2011,136(9):1859-1866
The use of an amorphous silicon-carbon alloy overcoating on silver nanostructures in a localized surface plasmon resonance (LSPR) sensing platform allows for decreasing the detection limit by an order of magnitude as compared to sensors based on gold nanostructures deposited on glass. In addition, silver based multilayer structures show a distinct plasmonic behaviour as compared to gold based nanostructures, which provides the sensor with an increased short-range sensitivity and a decreased long-range sensitivity. 相似文献