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161.
Structural and magnetic properties of Pr–Ni substituted Ca0.5Ba0.5Fe12O19 hexa-ferrite nanoparticles
Hasan M. Khan M.U. Islam Yongbing Xu Muhammad Naeem Ashiq Irshad Ali M. Asif Iqbal Muhammad Ishaque 《Ceramics International》2014
Effect of Pr–Ni substitution on structural and magnetic properties of Ca0.5Ba0.5−xPrxNiyFe12−yO19 (x=0.00–0.10 and y=0.00–1.00) prepared by the sol–gel auto combustion method were investigated. The XRD analysis confirmed the single phase M-type hexa-ferrite structure. The lattice parameters were found to increase as Pr–Ni content increases, which is attributed to the ionic size of the implicated cations. The Pr–Ni seems to be completely soluble in the lattice. Transmission electron microscopy reveals that the grain size decreases with increase of Pr–Ni substitution. The coercivity and remanent magnetization ranges from 1511 to 1925 (Oe) and 21.4 to 26.5 (emu/g), respectively. The coercivity values of all the samples fall in the range of M-type hexa-ferrites. 相似文献
162.
A numerical simulation for the modeling of solar kilns for hardwood timber drying with different boundary conditions has been developed in this work. This simulation has been used to predict the key behavior of the wood and the kiln itself under different geographical and weather conditions in Australia. This work, therefore, enables a site to be suggested that is likely to give the best kiln performance both in terms of the productivity and the quality of the end-use product. As test cases, realistic climatic conditions for three representative geographical locations in Australia, including Sydney (latitude 33.86°S), Melbourne (37.81°S), and Brisbane (27.46°S), have been considered in this simulation. Out of the three sites considered in this work, the fastest drying rates (and highest diffusion coefficients) were predicted in Brisbane. The highest level of instantaneous strain in the timber for this location was also predicted to be 0.0075 m/m, which is much less than the failure value (0.02 m/m). The moisture content distribution profile within the boards toward the end of the drying period was found to be almost uniform, which is likely to cause low degrade in the dried timber. 相似文献
163.
164.
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
165.
Waqar Ahmad Ali Al-Matar Zaheer Aslam Izhar A. Malik Hafiz M. Irshad 《Chemical Engineering Communications》2020,207(7):946-960
AbstractA series of Cu-K/Al2O3 catalysts were synthesized by wet impregnation technique. The reduced catalysts were further used for conversion of carbon dioxide to methane and carbon monoxide. Moreover, the fresh and used catalysts were characterized to investigate the changes in the surface morphology, metal dispersion, surface area, crystalline phases, and functional groups of studied catalysts. The SEM analysis of fresh and spent catalysts showed no remarkable difference in surface morphology with irregular shaped agglomerated particles. Furthermore, TEM micrographs presented the well distribution of metal catalyst over alumina support. The decrease in surface area from 115 to 77?m2/g for Cu1.62-K0.5/Al2O3 after reaction was related to sintering and oxidation of catalyst during reaction. XRD revealed the disappearance of some minor peaks which can be associated with the sintering of spent catalyst. FTIR also presented some new peak for spent catalyst which can be linked with metal oxides. Moreover, various reaction conditions of temperature (230, 400, and 600?°C), pressure (1 and 7?bar), and feed molar ratio of H2/CO2 (2:1 and 4:1) were investigated using different Cu loading (0, 1, 1.25, 1.62, and 4 weight percent). A maximum CO2 conversion of 63% with 39% CH4 selectivity was achieved by using Cu1.62-K0.5/Al2O3 at 600?°C, molar ratio of H2/CO2 4 under 7?bar. The presence of K on the surface of synthesized catalyst increased the CO2 conversion from 48% (Cu1/Al2O3) to 55% (Cu1-K0.5/Al2O3) at above mentioned reaction conditions which suggested the promoter effect of K during conversion of carbon dioxide. 相似文献
166.
Industrialization has led to a number of environmental problems, such as release of toxic metals and other toxic organic and inorganic compounds to the environment. Among all, the rapid expansion of leather related industries in Pakistan have resulted in considerable environmental problems and effluents from processing of both domestic and imported hides and skins have increased pollution to alarming levels. Some tannery effluents of Peshawar area investigated in the present study showed high concentrations of Cr(Ⅵ) (2.7-12.6 mg/L), Cu(Ⅱ) (2.6-11.4 mg/L) and phenol (0.1-4.2 mg/L). These contaminants are very toxic and must be removed from effluents before releasing into water bodies. A new technique of gamma irradiation has been investigated to decrease the load of COD and concentrations of Cr(Ⅵ), Cu(Ⅱ) and phenol associated with tannery effluents to the permitted values. It was observed that concentration of Cr(Ⅵ) in the effluents can be brought to the permitted level by applying radiation dose of 3 kGy. A radiation dose of 2.5 kGy was required to remove more than 95% of Cu(Ⅱ) and 100 % degradation of phenol in tannery effluents could be achieved by only one kGy of radiation dose. 相似文献
167.
168.
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
169.
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
170.
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