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排序方式: 共有495条查询结果,搜索用时 15 毫秒
1.
This paper discusses the essential elements for successful Total Quality Management (TQM) implementation in hospital, and the challenges that occur with such implementation. Guidelines for this implementation are provided to show how TQM tools can be used effectively in hospitals. 相似文献
2.
I. Kashif H. Farouk S. A. Aly A. M. Sanad M. H. El-Kottamy E. E. Assem 《Journal of Materials Science: Materials in Electronics》1992,3(3):144-146
The effect of the addition of Fe2O3 and heat treatment duration on the magnetic susceptibility of vanadium borophosphate glass were studied. The magnetic susceptibility of glass samples was found to increase with increasing Fe2O3 content, which may be explained by the formation of the FeO6 group and the change of Fe2+ to Fe3+ which has higher paramagnetic properties. No detectable changes in the magnetic susceptibility with heat treatment for the samples containing 0.0, 0.5 and 1.0 mol% Fe2O3 was observed. The magnetic susceptibility for the heat treated samples containing 2.5, 5.0 and 7.5 mol% Fe2O3 decreases sharply with increasing duration of heat treatment up to 6 h and then remains almost constant. The sharp decrease in magnetic susceptibility of 2.5 mol% Fe2O3 is attributed to the increase in the number of ferrous ions. The sharp decrease for samples containing 5.0 and 7.5 mol% Fe2O3 is attributed to the increase in the number of Fe3+ in tetrahedral co-ordination. The rate of crystallization owing to the heat treatment was calculated and was found to increase with increasing iron oxide content. The geometry of crystallization was found to be in three-, two-and one-dimension(s) for samples containing 2.5, 5.0 and 7.5 mol% Fe2O3, respectively. 相似文献
3.
The thermal behaviour of a packed bed storage system charged with hot air is modelled using two partial differential equations representing the energy conservation in the air and solid phases constituting the bed. These two equations are coupled through the heat exchange process between the two phases. A fully implicit numerical scheme based on forward, upwind and central differencing for the time, first and second space derivatives, respectively, is used to solve the modelling equations. Marching technique is used for the air equation and a tri-diagonal matrix solver is employed to solve the solid equation. The solution yields the thermal structure of the bed, namely the air and solid temperature distribution inside the bed at any particular time, and the variation of total energy stored in the bed with time. The effect of bed length, solid diameter and void fraction on the thermal characteristics of the packed bed is studied. Further, the performance of the bed under variable inlet air temperature and mass flow rate is investigated. 相似文献
4.
Leach characteristics of 137Cs and 60Co radionuclides from both ordinary Portland cement and cement mixed with two different ratios of silica fume and ilmenite have been studied using International Atomic Energy's (IAEA) standard leach method. A mathematical model has been simulated to predict the release rate of each nuclide from cubic geometry waste matrix and the predicted values are discussed in relation to experimentally observed leach rates to confirm the validity of the proposed mechanism in the model. The effect of temperature on the radionuclides leaching rates was also studied and the effective diffusion coefficients were obtained at different temperatures. The net fractional release of the two radionuclides from different waste forms showed a decreasing pattern as 137Cs>60Co, indicating the largest diffusion coefficient for cesium in all waste matrices. 相似文献
5.
Mohamed M. Abd-Alla Maher F. El-Zohry Kamal I. Aly Mohamed M. M. Abd-El-Wahab 《应用聚合物科学杂志》1993,47(2):323-329
A new interesting category of organometallic polyesters based on diarylidenecycloalkanones containing ferrocene derivatives in the polymer main chain has been prepared by interfacial polycondensation of 1,1′-dichlorocarbonyl ferrocene or 1,1′-dichlorocarbonyl-4,4′-diiodoferrocene with 2,5-bis(p-hydroxybenzylidene)cyclopentanone, 2,5-divanillylidenecyclopentanone, 2,6-bis(p-hydroxybenzylidene)cyclohexanone, 2,6-divanillylidenecyclohexanone, and 2,7-bis(p-hydroxybenzylidene) cycloheptanone. The resulting polyesters were characterized by elemental analyses, infrared spectroscopy, solubility, and viscometry measurements. The thermal behavior of the synthesized polymers was evaluated by thermal gravimetric analysis and correlated with their structures. The crystallinity of all polymers were examined by x-ray diffraction analysis. Moreover, the electrical conductivity of a selected example of polymer was investigated above the temperature range (300–500 K) and showed that it followed an Arrhenius-type equation with activation energy 2.09 eV. © 1993 John Wiley & Sons, Inc. 相似文献
6.
Different Estimation Methods for Constant Stress Accelerated Life Test under the Family of the Exponentiated Distributions 下载免费PDF全文
Abdallah A. Abdel Ghaly Hanan M. Aly Rana N. Salah 《Quality and Reliability Engineering International》2016,32(3):1095-1108
The Accelerated Life Testing (ALT) has been used for a long time in several fields to obtain information on the reliability of product components and materials under operating conditions in a much shorter time. One of the main purposes of applying ALT is to estimate the failure time functions and reliability performance under normal conditions. This paper concentrates on the estimation procedures under ALT and how to select the best estimation method that gives accurate estimates for the reliability function. For this purpose, different estimation methods are used, such as maximum likelihood, least squares (LS), weighted LS, and probability weighted moment. Moreover, the reliability function under usual conditions is predicted. The estimation procedures are applied under the family of the exponentiated distributions in general, and for the exponentiated inverted Weibull (EIW) as a special case. Numerical analysis including simulated data and a real life data set is conducted to compare the performances between these four methods. It is found that the ML method gives the best results among other estimation methods. Finally, a comparison between the EIW and the Inverted Weibull (IW) distributions based on a real life data set is made using a likelihood ratio test. It is observed that the EIW distribution can provide better fitting than the IW in case of ALT. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
7.
Abd El Munim HE Farag AA 《IEEE transactions on pattern analysis and machine intelligence》2007,29(6):945-958
In this paper, we revisit the implicit front representation and evolution using the vector level set function (VLSF) proposed in (H. E. Abd El Munim, et al., Oct. 2005). Unlike conventional scalar level sets, this function is designed to have a vector form. The distance from any point to the nearest point on the front has components (projections) in the coordinate directions included in the vector function. This kind of representation is used to evolve closed planar curves and 3D surfaces as well. Maintaining the VLSF property as the distance projections through evolution will be considered together with a detailed derivation of the vector partial differential equation (PDE) for such evolution. A shape-based segmentation framework will be demonstrated as an application of the given implicit representation. The proposed level set function system will be used to represent shapes to give a dissimilarity measure in a variational object registration process. This kind of formulation permits us to better control the process of shape registration, which is an important part in the shape-based segmentation framework. The method depends on a set of training shapes used to build a parametric shape model. The color is taken into consideration besides the shape prior information. The shape model is fitted to the image volume by registration through an energy minimization problem. The approach overcomes the conventional methods problems like point correspondences and weighing coefficients tuning of the evolution (PDEs). It is also suitable for multidimensional data and computationally efficient. Results in 2D and 3D of real and synthetic data will demonstrate the efficiency of the framework 相似文献
8.
P. Yalamanchili Z. Al Aly E. Gonzalez . 《Hemodialysis international. International Symposium on Home Hemodialysis》2004,8(1):95-96
Valproic acid toxicity is not infrequent and is difficult to treat, as there is no specific antidote. In the past, this drug was considered unremovable by extracorporeal methods because of the highly protein bound state (90–95%). However, recent reports suggest that the toxicokinetics of valproate vary considerably from the pharmacokinetics at therapeutic levels, and at higher concentrations protein‐binding sites become saturated. The drug's relatively low molecular weight (144 Da), small volume of distribution (0.13–0.23 L/kg), and saturable protein binding render it potentially amenable to extracorporeal removal, but published experience is scant and there are only a few reported instances in which patients were successfully treated with extracorporeal methods. Here we report the case of a patient with serious valproate toxicity treated with simultaneous “in series” hemodialysis and hemoperfusion followed by continuous veno‐venous hemodiafiltration. A 35‐year‐old homeless male presented to the emergency department after ingesting 120 pills of valproic acid. Initial valproic acid level was 59 µg/mL. Urine drug screen was negative and serum chemistries including LFTs were normal. He was treated with activated charcoal and admitted to the intensive care unit. 4 h later, he developed respiratory failure and became hemodynamically unstable. He was intubated and successfully resuscitated. Subsequently, the valproic acid level was found to be 553 µg/mL and a decision was made to employ extracorporeal methods for drug removal. “In series” hemodialysis and hemoperfusion were done for 4 h and simultaneous blood samples for measurement of valproic acid levels were obtained as blood entered the hemoperfusion column (arterial) and as it exited the hemodialysis membrane (venous). Extraction ratio, whole blood, and plasma clearances were calculated and they compared substantially with the published data. The above measures decreased valproate levels from 572.6 (pre‐dialysis level) to 203.2 µg/mL. This was followed by continuous veno‐venous hemodiafiltration for 18 h, which sustained the drug removal and prevented significant post‐dialytic rebound. This is the first reported instance in which these three methods were administered together successfully in the management of valproic acid toxicity. 相似文献
9.
The effect of gypsum in slag-blended cement on free and restrained shrinkage of concrete subjected to various curing conditions
is presented in this paper. Added gypsum in slag-blended cements was found to increase the autogenous shrinkage of concrete
up to 56 days. However, added gypsum caused small reduction in the long-term shrinkage when the concrete was exposed to drying.
Slag concretes with 3% added gypsum content, when exposed to drying at the age of 24 h, exhibited more cracking tendency than
comparable concrete with 0% added gypsum. This is attributed to the increased shrinkage evolution of slag concrete with 3%
gypsum content at early ages. However, if moist cured for 7 days, increasing the amount of gypsum from 3 to 5% in slag-blended
cement reduced the cracking tendency. It is concluded that the beneficial effect of increasing gypsum in reducing cracking
tendency in slag concrete is only favourable if moist cured for 7 days. 相似文献
10.
M. Sh. El-Gayar A. E.-M. Ahmed G. A. Gohar A. H. Hegazi H. M. Ibrahim A. M. Aly 《Petroleum Science and Technology》2013,31(14):1434-1444
Abstract Vacuum distillates of an Egyptian crude oil were subjected to solvent extraction process applying N-methyl-2-pyrrolidone (NMP) and furfural as dearomatization solvents. The study shows that the extraction solvent together with the temperature and solvent-to-oil ratio have a significant effect on the yield and quality of produced lubricating oils. The optimum temperature for extracting light waxy distillates with NMP is 55°C at the solvent-to-feed ratio 2:1. These conditions are appropriate to remove the major portion of aromatics from the raffinate. The apparent activation energy (Ea), enthalpy (ΔH*), entropy (ΔS*), and free energy of activation (ΔG*) were calculated for the solvent dearomatization process. 相似文献