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11.
拉斯干酪添加有超滤牛乳制得,该牛乳中乳固形物质量分数分别为对照样(纯牛乳)的1.4、1.6和2.0倍,成熟3个月.拉斯干酪显示了比对照样更高的干酪得率,其水分、脂肪质量分数和pH值与对照样的相似,在成熟期均呈下降趋势,但氮质量分数等均呈上升趋势,且以牛乳中乳固形物质量分数提高到对照样的1.6倍时最高.结果表明,乳固形物质量分数为对照样1.6倍时牛乳制得的拉斯干酪其感官特性最佳. 相似文献
12.
This paper reports of a comprehensive study on the durability properties of concrete containing polypropylene fiber and fly ash. Properties studied include unit weight and workability of fresh concrete, and compressive strength, modulus of elasticity, porosity, water absorption, sorptivity coefficient, drying shrinkage and freeze–thaw resistance of hardened concrete. Fly ash content used in concrete mixture was 0%, 15% and 30% in mass basis, and fiber volume fraction was 0%, 0.05%, 0.10% and 0.20% in volume basis. 相似文献
13.
I. K. El Zawawi K. Sedeek A. Adam Manal A. Mahdy 《Journal of Materials Science: Materials in Electronics》2011,22(7):825-832
Undoped and Mn doped ZnSe nanoparticles thin films of thickness ranging from 20 to 120 nm have been successfully synthesized
via inert gas condensation (IGC) technique with constant Argon gas flow rate and deposition temperature 300 K. The energy
dispersive X-ray analysis (EDX) for freshly deposited Zn1−xMnxSe thin films were carried out and revealed that Mn contents (x) were 0, 0.05, 0.16 and 0.25. The as-prepared deposited thin
films of different thickness were examined using transmission electron microscope (TEM) and showed that all films were nanocrystalline
with particle size ranging from 4.1 to 6.6 nm. The grazing incident in-plane X-ray diffraction (GIIXD) patterns verified nanocrystalline
single phase zinc blende structure for 80 nm film thickness for all examined Zn1−xMnxSe compound films. A broadening of main characteristic lines (111), (220) and (311) of cubic phase was observed and was attributed
to the lower particle size in nanocrystalline examined Zn1−xMnxSe compound films. 相似文献
14.
F.M. Hady R.A. Mohamed A. Mahdy 《International Communications in Heat and Mass Transfer》2006,33(10):1253-1263
We formulate the problem of free convection from a vertical wavy surface embedded in a uniform porous medium in the presence of an external magnetic field and internal heat generation or absorption effects. Using the appropriate transformations, the boundary layer equations are reduced to non-linear partial differential equations. The transformed boundary layer equations are solved numerically using Runge–Kutta integration scheme with the shooting technique. We have focused our attention on the evaluation of the local Nusselt number Nux, dimensionless velocity, f′, and temperature, θ. The governing parameters are the amplitude of the waviness of the surface, a, ranging from 0.0 (flat plate) to 0.3, and the heat generation absorption parameter Q ranging from − 0.25 to 0.25, and magnetic parameter Mn, ranging from 0.0 to 2.0. The effect of all these parameters are discussed and plotted. 相似文献
15.
On the electrochemical behaviour of the anodic oxide film on tungsten in HCOOH and CH3COOH solutions
The electrochemical behaviour of the anodic oxide film on tungsten during, or after, interruption of current flow was studied in HCOOH and CH3COOH solutions by galvanostatic and capacitance techniques. The results show the conditions under which enhancement of film growth occurs as revealed from its formation and dissolution characteristics. The results also show the possibility of the electrochemical oxidation of formic acid by the thick oxide film on tungsten. The importance of this electrocatalytic process is the occurrence of the oxidation process without appreciable oxygen evolution. The galvanostatic oxidation of tungsten in HCOOH as a reducing agent can be considered as a novel method for the preparation of a class of oxides; oxidation with simultaneous partial reduction. 相似文献
16.
Manal A. Mahdy Sayed H. Kenawy Esmat M.A. Hamzawy Gehan T. El-Bassyouni I.K. El Zawawi 《Ceramics International》2021,47(9):12047-12055
The influence of adding 10, 20 and 30% molar ratio of silicon carbide (SiC) separately to a composite of wollastonite (W) with a fixed content of 10%Fe2O3 prepared by wet precipitation method was studied. The crystal structure of the annealed composite powders was inspected by X-ray diffraction (XRD); revealing multi-phase structure. The highest estimated crystallite size investigated by Scherrer equation of W, SiC, WFe:SiC10, WFe:SiC20 and WFe:SiC30 were 53.89, 54.6, 56.3, 48.5 and 54.6 nm respectively; demonstrating the formation of nanocomposites. Particles shape, size and crystallinity of the samples were studied using high resolution transmission electron microscope (HR-TEM). The band gap Eg values of the nanocomposites increased with SiC content having an intermediate value that lies between that of γ-Fe2O3 (maghemite) and SiC. Ferromagnetic and paramagnetic contributions were observed in the magnetic hysteresis loops for the composites. This study highlighted that the coercive field (Hci) of the composites improved with increasing the SiC content. The innovative wollastonite/Fe2O3/SiC with amended magnetic properties elicited attention due to their promising application in bone filler and industrial purposes. 相似文献
17.
Harandizadeh Hooman Jahed Armaghani Danial Khari Mahdy 《Engineering with Computers》2021,37(1):685-700
Engineering with Computers - Prediction of ultimate pile bearing capacity with the aid of field experimental results through artificial intelligence (AI) techniques is one of the most significant... 相似文献
18.
Mahdy A.M. Anis H.I. Ward S.A. 《Dielectrics and Electrical Insulation, IEEE Transactions on》1998,5(4):612-617
The dielectric breakdown of air insulating systems is believed to be sensitive to local irregularity of the electric field which may result from the presence of defects such as contaminants adhering to electrode surfaces and surface roughness. Normally metal machining methods are used to eliminate such electrode surfaces irregularities. However, system aging and harsh operating conditions create and sustain such rough surface conditions which may, in turn, lead to the failure of insulation under the resulting enhanced electric stresses. Electrode surface roughness causes a large reduction in the breakdown strengths of gas insulated apparatus. Surface roughness leads to the existence of localized microscopic regions with local field intensities larger than the average field in the gas near the electrodes. This paper models the insulation breakdown mechanism in the presence of such surface roughness, or protrusions, taking into account their random nature which lends the problem to probabilistic treatment. In order to generalize the surface roughness effect on the dielectric withstand of air-insulated systems, surface roughness is simulated by using a random event generator. The perturbations which these protrusions inflict on the field distribution in a nearly-uniform field gap are assessed. The corresponding breakdown voltages are estimated for different patterns of surface roughness. The results are statistically formulated 相似文献
19.
The Journal of Supercomputing - Large-scale computing platforms become essential in nowadays business and scientific activities. The electrical energy consumed by such platforms increases... 相似文献
20.
In cooperative communications, the problem of error propagation has a detrimental effect on the diversity order of the wireless system. To mitigate such an effect, we present a relaying scheme that is based on the absolute value of the log-likelihood ratio (LLR) of the received message signals at both the relay node and the destination node. The calculated LLR values are then compared to each other and based on the result of the comparison, a decision is made on whether or not to activate the relay node. The proposed scheme does not rely on any threshold, and is thus simple in nature. A closed-form expression is derived for the bit-error-rate (BER) of the proposed scheme. The theoretical developments are validated by simulations. As a means for performance measurement, the proposed scheme is compared to its counterparts and is shown to provide a better BER performance at a much lower complexity. Furthermore, a closed-form expression of the outage probability is also derived. 相似文献