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51.
Abstract

Of the voluminous resolutions issued by United Nations General Assembly, the Millennium Declaration, adopted in 2000, is one of the most significant. It specifies eight development goals and sets the year 2015 as the target date for achieving such goals. Although water is not explicitly mentioned as one of those eight principal goals, it is specified as a subset under one of those goals. Three years later, the United Nations General Assembly paid special attention to water by issuing a separate resolution declaring the period 2005 to 2015 as the “International Decade for Action, Water for Life.” This article reviews and discusses the Resolution and analyzes its added value.  相似文献   
52.
53.
Fetal tissue transplantation has gathered considerable interest among researchers dealing with organ transplantation. A large number of studies concerning fetal intestinal transplantation have been published in the past 2 decades, almost all of them aiming to determine the feasibility of a properly functioning fetal transplant in continuity with the host's own enteral system. This study was designed to determine the absorptive capacity of the neogut in vivo, without anastomosing the transplant to the host's intestine, and to evaluate its use as an accessory enteral segment. Intestinal segments taken from Wistar albino fetuses were transplanted subcutaneously into the abdominal wall of 20 Sprague-Dawley rats. Immunosuppression was maintained by daily cyclosporin A (Cy A) 10 mg/kg injections s.c. and evaluated by determination of serum Cy A level and T-helper/T-suppressor cell ratio. The neogut was converted into a Thiry-Vella loop 2 weeks after transplantation. A test solution composed of 20% glucose and Trophamine was perfused via the stomas; glucose and amino acid absorption gradients were calculated. The gamma-glutamyl transferase (GGT) activity and mitotic index of the neogut were determined. Results were compared to those obtained from the host. There was no significant difference (P > 0.05) in glucose absorption between the neogut and the host tissue. Amino acid absorption and specific GGT activity were significantly less (P < 0.01) in the neogut. There was no significant difference (P > 0.05) between neogut and host intestine in mitotic index. Our data support the idea of using a transplanted fetal intestinal segment as an accessory feeding route.  相似文献   
54.
This paper investigates the effects of microwave irradiation on the synthesis of zeolite Na-A from coal fly ash at atmospheric pressure. Microwave irradiation has shown to accelerate zeolitization from several hours to several minutes. A single-mode laboratory-scale microwave was employed, which enabled control of irradiated power and temperature of the reaction mixture, while the pressure was controlled by affixing a condenser on the 40 mL Teflon reactor vessel with a working volume 20 mL. Design of Experiment was used to compare two methods of converting CFA to zeolite-A, direct hydrothermal method and indirect fusion method. Experiments conducted were two level four factorial designs. The first factor considered was the categorical factor of conversion method (hydrothermal vs fusion), while the other three factors investigated were power (P), time (θ), and aluminate concentration (δ). Zeolite produced from CFA (CFAZA) was characterized using XRD, FTIR, SEM, TGA, BET, and cation exchange capacity. It was observed that the crystallinity of the product was influenced by factors such as, conversion method, power, time, and aluminate concentration. The hydrothermal and fusion products were comparable to each other in their characteristics, however, hydrothermal CFAZA performed better at immobilizing heavy metal ions and showed better crystalline structure, whereas fusion CFAZA had a higher BET surface area and a slightly higher CEC. Regardless of the performance of the categorical factors the other factors, i.e., power, time, and aluminate concentration followed the same trend for both types of CFAZA.  相似文献   
55.
This article presents machinability of 17-4PH stainless steel using a hybrid technique composed of plasma-enhanced turning and cryogenic turning. First of all, using some primary experimental tests and nonlinear regression, a mathematical model was developed for surface temperature of uncut chip as a function of plasma current and cutting parameters. Then, the influence of cutting speed (Vc), feed (f), and surface temperature of uncut chip (Tsm) was studied on surface roughness (Ra), cutting force (Fz), and tool flank wear (VB). The results show that hybrid turning (HYT) is able to lower the main cutting force and tool flank wear in comparison with conventional turning. In addition, surface roughness was improved except for high level of surface temperature of uncut chip. However, hardness measurement of machined workpiece showed that HYT does not change the hardness of machined surface.  相似文献   
56.
Today, there is a high level of demand for sustainable buildings. The most important decisions regarding a building's sustainable features are made during the design and preconstruction stages. Leadership in Energy and Environmental Design (LEED®) is the most widely adopted sustainable building rating system in the United States. For projects pursuing LEED® certification, designers have to conduct in-depth sustainability analyses based on a building's form, materials, context, and mechanical-electrical-plumbing (MEP) systems. Since Building Information Modeling (BIM) allows for multi-disciplinary information to be superimposed within one model, it creates an opportunity to conduct these analyses accurately and efficiently as compared to the traditional methods. In this exploratory research, a case study was conducted on Salisbury University's Perdue School of Business building to demonstrate the use of BIM for sustainable design and the LEED® certification process. First, a conceptual framework was developed to establish the relationship between BIM-based sustainability analyses and the LEED® certification process. Next, the framework was validated via this case study. The results of this study indicate that documentation supporting LEED® credits may be directly or indirectly prepared using the results of BIM-based sustainability analyses software. This process could streamline the LEED® certification process and save substantial time and resources which would otherwise be required using traditional methods.  相似文献   
57.
Myocardial perfusion SPECT using the prone position improves inferior wall counts and decreases motion problems as compared with the usual supine position. Nonetheless, it is not suitable for women. In addition, it is associated with artifactual anteroseptal defects and hot spots. METHODS: The right lateral (RL) position was evaluated instead of the prone position in 72 patients (26 women). RL imaging was performed immediately after the supine imaging during a routine 2-day 99mTc-sestamibi exercise protocol. The SPECT images were scored semiquantitatively by three physicians. Moreover, regional myocardial counts, as well as extent and severity of defects, were assessed by quantitative polar map analysis. RESULTS: All patients tolerated the RL position well and there was no significant patient movement in either position. Higher inferior myocardial counts per pixel were observed in the RL than in supine images. Inferior wall defects (especially mild ones) were more common in the supine than the RL images, whereas defects in other regions were not different. Quantitative analysis confirmed these findings. Analysis of 34 patients with recent coronary arteriography revealed an overall coronary artery disease (CAD) supine- and RL-imaging specificity of 50% and 75%, respectively, and the sensitivities of both were 93%. Right CAD sensitivity, specificity and normalcy rates for the supine position were 100%, 44% and 55%, whereas those of the RL position were 94%, 75% and 90%, respectively. CONCLUSION: The RL position improves CAD diagnostic accuracy, particularly right CAD, without significant artifacts in other myocardial regions. Unlike the prone position, the RL position is well tolerated by both women and men.  相似文献   
58.
Superfluid3He in severely confined geometries is studied in the Ginzburg-Landau limit. Both A and B phases are analyzed in narrow slabs and in small cylinders. Physically measurable quantities include the superfluid density and the critical current, which are significantly suppressed by the boundaries. Related alterations in the phase diagram are also considered. For small lateral dimensions, the A phase can be favored even well below the polycritical pressure.  相似文献   
59.
The chemical durability of some selected glass-ceramic materials based on the Li2O- (MnO, CaO)MgO---Al2O3---SiO2 glass composition, has been determined by HCl, using the powder test.

The leachability of the glass-ceramic was gradually increased by replacing MgO with MnO, while it was decreased by addition of MnO instead of CaO. Calcium oxide had a retarding effect on the durability of the material when it was added instead of MgO and/or MnO. However, on the addition of Al2O3 in replacing Li2O, the durability of the material was markedly improved. The leaching data were found to be dependent mainly on the proportion of the glass oxide constituents i.e. MgO/MnO, CaO/MnO and Li2O/Al2O3 ratios present in the glasses.

The results were correlated to different views concerning the effect of various ions on the rate of interdiffusion between the crystalline-glass materials and leaching solution, the type, and proportions of the crystalline phases developed in glass-ceramics and residual glass phase.  相似文献   

60.
Phase transformations have been studied in glasses related in composition to Li2O-MgO-SiO2 (930° C) eutectic glass modified by Al2O3Li2O replacement on a cation per cation basis. Crystallization processes and changes in the solid solutions of the mineral phases developed during the controlled heating of the glasses have been followed using X-ray and microscopic techniques.Solid solutions of lithia aluminosilicate phases (B-eucryptite and/or B-spodumene s.s.) are the essential minerals that crystallize in glasses through most of the heat treatment applied. Lithium metasilicate, disilicate, clinoenstatite and cordierite are also encountered.B-eucryptite s.s. is formed in early stage of crystallization of the glass which transforms into B-spodumene s.s. at higher temperature (800° C). However, in some cases, it persists at temperatures as high as 1000° C.Metastable B-eucryptite-B-quartz s.s. can accomodate considerable amounts of Mg2+ and Al3+ ions in its lattice especially at lower temperature. At higher temperature for long duration, a redistribution of the elements takes place, and the cordierite phase then developed.  相似文献   
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