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101.
Syed Safdar Ali Khalid Mohammed Khan Hartmut Echner Wolfgang Voelter Mashooda Hasan Atta-ur-Rahman 《Advanced Synthesis \u0026amp; Catalysis》1995,337(1):12-17
Two new synthons, Fmoc-L-Arg(biphenyl-4-sulphonyl)-OH ( 8 ) and Fmoc-Arg(4-methoxy-3-t-butylbenzenesulphonyl)-OH ( 14 ), are prepared for the synthesis of arginine-containing peptides. These groups are cleaved by commonly employed trifluoroacetic acid and methanesulphonic acid. Kinetic studies reveal that extended bicyclic aromatic conjugation, as in biphenyl, slightly improves the acid lability compared to the electron-donating t-butyl group. 相似文献
102.
The low temperature oxidation of a Montana subbituminous coal was investigated using round bottom 100 ml flasks in constant temperature baths. The experiments were carried out in normal and oxygen enriched air at 30°C, 45°C and 70°C with particle sizes ranging from 4 mesh to 100 mesh. Periodic analysis of gas samples from the flasks provided the rate data. The reactivity of the as received coal was compared with that of the same coal dried (i) in high pressure steam and (ii) in hot water
A rate equation has been proposed incorporating the effects of oxygen diffusion and surface reaction. For higher oxygen concentration and smaller particle sizes, the zero order surface reaction was found to be controlling. The temperature dependency of the reaction rate was found to be well represented by the Arrhenius equation. The activation energy varied slightly under various conditions between 15 to 20 kca)/g mole
The reactivity of the hot water dried coal was found to be similar to that of the as received coal. Steam dried coal however, was found to be much less reactive. 相似文献
A rate equation has been proposed incorporating the effects of oxygen diffusion and surface reaction. For higher oxygen concentration and smaller particle sizes, the zero order surface reaction was found to be controlling. The temperature dependency of the reaction rate was found to be well represented by the Arrhenius equation. The activation energy varied slightly under various conditions between 15 to 20 kca)/g mole
The reactivity of the hot water dried coal was found to be similar to that of the as received coal. Steam dried coal however, was found to be much less reactive. 相似文献
103.
The Jameson flotation cell has been commonly used to treat a variety of ores (lead, zinc, copper etc.), coal and industrial minerals at commercial scale since 1989. It is especially known to be highly efficient at fine and ultrafine coal recovery. However, although the Jameson cell has quite a simple structure, it may be largely inefficient if the design and operating parameters chosen are not appropriate. In this study, the design and operating parameters of a pilot scale Jameson cell were optimized to obtain a desired metallurgical performance in the slime coal flotation. The optimized design parameters are the nozzle type, the height of the nozzle above the pulp level, the downcomer diameter and the immersion depth of the downcomer. Among the operating parameters optimized are the collector dosage, the frother dosage, the percentage of solids and the froth height. In the optimum conditions, a clean coal with an ash content of 14.90% was obtained from the sample slime having 45.30% ash with a combustible recovery of 74.20%. In addition, a new type nozzle was developed for the Jameson cell, which led to an increase of about 9% in the combustible recovery value. 相似文献
104.
105.
Hüseyin Çelikkan A. Elif Sanli Hasan Aydin M. Levent Aksu 《Journal of Applied Electrochemistry》2009,39(9):1525-1533
This study was carried out to investigate the electrochemical behavior of boron tribromide in dimethlyformamide. The reduction
of the compound was found to follow a CE mechanism. The kinetic parameters and the diffusion coefficient were calculated by
the use of ultramicrodisc electrodes and chronoamperometry. The number of electrons transferred was found to be 2 by rotating
disc and ultramicro disc electrodes and 3 by coulometry. These results are in good accordance with those obtained from molten
boron salts. This study is important in regard to electrochemical boronizing at low temperatures. 相似文献
106.
Fire detection in video sequences using a generic color model 总被引:3,自引:0,他引:3
In this paper, a rule-based generic color model for flame pixel classification is proposed. The proposed algorithm uses YCbCr color space to separate the luminance from the chrominance more effectively than color spaces such as RGB or rgb. The performance of the proposed algorithm is tested on two sets of images, one of which contains fire, the other containing fire-like regions. The proposed method achieves up to 99% fire detection rate. The results are compared with two other methods in the literature and the proposed method is shown to have both a higher detection rate and a lower false alarm rate. Furthermore the proposed color model can be used for real-time fire detection in color video sequences, and we also present results for segmentation of fire in video using only the color model proposed in this paper. 相似文献
107.
M. Schulz R. Moshammer M. Dürr A. Hasan M.F. Ciappina 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2009,267(2):187-191
Recent developments on kinematically complete experiments on basic atomic fragmentation processes are reviewed. Comparisons between theoretical and experimental fully differential cross sections for single ionization of light atoms by charged particle impact are analyzed. Furthermore, a method developed very recently, four-particle Dalitz plots, is discussed in context of double ionization. The extraordinary power of these plots is their capability to provide a comprehensive picture of the momentum exchange between all four final-state particles in a single spectrum. 相似文献
108.
Hypocholesterolaemic effect of yoghurt containing Bifidobacterium pseudocatenulatum G4 or Bifidobacterium longum BB536 总被引:4,自引:0,他引:4
The effect of a yoghurt supplement containing Bifidobacterium pseudocatenulatum G4 or Bifidobacterium longum BB536 on plasma lipids, lipid peroxidation and the faecal excretion of bile acids was examined in rats fed a cholesterol-enriched diet. After 8 weeks, the rats in the positive control (PC) group who were fed the cholesterol-enriched diet showed significant increases in plasma total cholesterol (TC), low-density lipoprotein (LDL) cholesterol, and malondialdehyde (MDA). However, groups fed a cholesterol-enriched diet supplemented with yoghurt containing B. pseudocatenulatum G4 or B. longum BB536 had significantly lower plasma TC, LDL-C, very-low-density lipoprotein (VLDL) cholesterol, and MDA than had the PC group after 8 weeks of treatment. In addition, faecal excretion of bile acids was markedly increased in the rats fed the yoghurt containing B. pseudocatenulatum G4 or B. longum BB536 as compared to the PC and NC groups. 相似文献
109.
Oktay H. Ozturk Yesim Can Zafer Yonden Sedat Motor Gonul Oktay Hasan Kaya Mutay Aslan 《Lipids》2013,48(12):1217-1226
Although hypocholesterolemia is a reported finding in sickle cell disease (SCD), low-density lipoprotein (LDL)/high-density lipoprotein (HDL) subfractions and HDL-associated enzymes have not been determined in SCD patients. Blood was collected from 38 hemoglobin (Hb)A volunteers and 45 homozygous HbSS patients who had not received blood transfusions in the last 3 months. Serum lipids were measured by automated analyzer while LDL and HDL subfraction analysis was done by continuous disc polyacrylamide gel electrophoresis. Serum levels of cholesteryl ester transfer protein (CETP), lecithin-cholesterol acyltransferase (LCAT), apolipoprotein B (apoB) and apolipoprotein A-1 (apoA-I) were determined by enzyme-linked immunosorbent assay (ELISA). Total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) levels were significantly decreased, while TG levels were significantly increased in SCD patients compared to controls. A significant decrease in intermediate-density lipoprotein (IDL)-C, IDL-B, IDL-A and LDL-1 fractions were seen in SCD patients, while no significant difference was observed in small dense LDL particles. A significant decrease was seen in HDL-large, HDL-intermediate and HDL-small fractions in SCD patients versus controls. Levels of LCAT and ApoA-1 protein measured in SCD patients were significantly lower while no significant difference was observed in CETP and ApoB protein levels compared to controls. The reduction observed in LDL- and HDL-C in SCD patients was reflected as significantly decreased IDL, LDL-1 and HDL-subfractions. Decreased HDL subfractions may possibly lead to the reduced ApoA-1 and LCAT protein levels observed in SCD patients. 相似文献
110.
Bogdan M. Leu Hasan Yavaş Innokenty Kantor Vitali B. Prakapenka 《Journal of the American Oil Chemists' Society》2010,87(12):1517-1520
We measured the velocity of sound in olive oil under pressure with the Brillouin light scattering technique. Using the values
for the density and the thermal conductivity that have only recently been reported, we calculated the adiabatic compressibility
and the isobaric specific heat up to 356 MPa and the thermal diffusivity up to 200 MPa. The specific heat displays a maximum
at 124 MPa, suggesting a possible phase transition around this pressure. Apart from the theoretical and practical importance
of these results for the food industry and beyond, this work shows that Brillouin light scattering and macroscopic methods
are complementary and can be employed to measure thermophysical parameters of food liquids under pressure. 相似文献