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91.
The authors present a simple liver biopsy protocol that is a reliable and cost-effective method of diagnosing hepatic Wilson's disease. Biopsy specimens are obtained in routine fashion, without the need for copper-free solutions or instruments. The samples are then embedded in paraffin, stained for copper and copper-associated protein, and studied by light microscopy. Subsequently, a sample of hepatic parenchyma is excised from the paraffin block for chemical quantitation of tissue copper. This combination of methods generally yields reliable results and allows confirmation of the diagnosis in cases of Wilson's disease in which special stains for copper are negative. In most instances, electron-microscopic studies are not necessary. 相似文献
92.
Firewall testing is one of the most useful of a set of alternatives for evaluating the security effectiveness of a firewall. A major advantage of firewall testing is being able to empirically determine how secure a firewall is against attacks that are likely to be launched by network intruders. This article advances the view that firewall testing should examine not only the ability of a firewall to resist attacks from external sources, but also the defences of the entire network that the firewall protects against external threats. Accordingly, testing should follow a systematic methodology to ensure that it is complete and appropriate, and to reduce the risk of damage and/or disruption to networks and hosts within. 相似文献
93.
Arash Yavari Shahram Sarkani E. Thomas Moyer Jr. 《International Journal of Fracture》2002,114(1):1-27
In this paper we study the mechanical attributes of the fractal nature of fracture surfaces. The structure of stress and strain singularity at the tip of a fractal crack, which can be self-similar or self-affine, is studied. The three classical modes of fracture and the fourth mode of fracture are discussed for fractal cracks in two-dimensional and three- dimensional solid bodies. It is discovered that there are six modes of fracture in fractal fracture mechanics. The J-integral is shown to be path-dependent. It is explained that the proposed modified J-integrals in the literature that are argued to be path-independent are only locally path-independent and have no physical meaning. It is conjectured that a fractal J-integral should be the rate of potential energy release per unit of a fractal measure of crack growth. The powers of stress and strain singularities at the tip of a fractal crack in a strain-hardening material are calculated. It is shown that stresses and strains have weaker singularities at the tip of a fractal crack than they do at the tip of a smooth crack. 相似文献
94.
The nature of the hydration and aggregation of di(2-ethylhexyl) sulfoxide (DEHSO) dissolved in wet dodecane at 25 °C has been characterized using Fourier transform infrared (FTIR) spectrophotometry, Karl Fischer titrations, and tritium-tracer equilibrium measurements. Least-squares computer modeling of the water content of 0.01-to-0.4 M DEHSO solutions equilibrated with water (optionally containing nonextractable CaCl2 to adjust the water activity ay in the range 0.28 to 1.0) indicates that the expected 1:1 species DEHSO H20 predominates at low DEHSO concentration (K11 = {DEHSO H20} / ({DEHS0]aw.) = 0.12 ± 0.01) with additional formation of hyarated dimeric species at the higher DEHSO concentrations. Analysis of the water vibrational bands in the FTIR spectra of 0.01-to-0.4 M DEHSO solutions in equilibrium with pure water supports the formation of both the 1:1 species and a dimer, identified by its spectral characteristics as the 2:1 dimer monohydrate. By reference to the available literature on the hydration of weak bases, the results suggest that at least part of the ‘nom'deaiityrsquo; of solutions of weak-base extractants in wet nonpolar diluents may be explained by formation of the discrete 1:1 and 2:1 monohydrate species. 相似文献
95.
96.
Lili Wu Ling Li Samuel F. Evans Tessa A. Eskander Bruce A. Moyer Zhichao Hu Paul J. Antonick Stephen Harrison M. Parans Paranthaman Richard Riman Alexandra Navrotsky 《Journal of the American Ceramic Society》2019,102(5):2398-2404
Layered aluminum double hydroxide chloride sorbents, LiCl∙Al2(OH)6.nH2O, Li-LDH, have shown promising application in selective Li extraction from geothermal brines. Maintaining LiCl uptake capacity and retaining a long cycle life are critical to widespread application of sorbent materials. To elucidate the energetics of Li capture, enthalpies of LDH with different Li content have been measured by acid solution calorimetry. The formation enthalpies generally become less exothermic as the Li content increases, which indicates that Li intercalation destabilizes the structure, and the enthalpies seem to approach a limit after the Li content x = 2Li/Al exceeds 1. To improve stability, metal doping of the aluminum LDH structure with iron was performed. Introduction of a metal with greater electron density but a similar ionic radius was postulated to improve the stability of the LDH crystal structure. The calorimetric results from Fe-doped LDH samples corroborate this as they are more exothermic than LDH-lacking Fe. This suggests that Fe doping is an effective way to stabilize the LDH phase. 相似文献
97.
Dmitri M. Orlov Todd E. Evans Richard A. Moyer Michael J. Schaffer Oliver Schmitz Alberto Loarte 《Fusion Engineering and Design》2012,87(9):1536-1543
In this work we evaluated the ITER ELM coils design based on two metrics: the Chirikov vacuum magnetic island overlap parameter, and the vacuum Field Line Loss Fraction. The study was performed for a range of current amplitudes for three different n = 4 waveforms: square, cosine and sine. The results indicated that ITER ELM coils are designed with a high level of flexibility to accommodate different operation scenarios (H-mode and Steady State) with different values of q95 and q-profiles. The magnetic island overlap analysis showed that ITER ELM coils are capable of matching the DIII-D I-coil spectrum. The Field Line Loss analysis showed that edge vacuum stochastization might be achieved that is similar or greater than in DIII-D. Fault analysis of the coils indicated that ITER ELM coils are robust and show good characteristics even with 11% of dead coils. 相似文献
98.
Lynch J.J. Moyer H.P. Schaffner J.H. Royter Y. Sokolich M. Hughes B. Yoon Y.J. Schulman J.N. 《Microwave Theory and Techniques》2008,56(7):1592-1600
99.
Diffusion in the β(bcc) phase field of the Fe-Ni-Al system was investigated at 1004°C with solid-solid diffusion couples assembled
with β2 alloys of selected composition. Experimental diffusion paths were determined for all couples and interdiffusion coefficients
calculated at composition points corresponding to intersections of diffusion paths and maxima and minima of concentration
profiles. The dependence of interdiffusion coefficients on composition was most clearly presented in terms of the parameter
Fe/(Fe + Ni). The diffusive interactions between aluminum and nickel as represented by the cross coefficients were either
positive or negative depending on the ternary composition. The Fe/(Fe + Ni) ratio appeared to be a significant parameter since
iron and nickel atoms behave differently in affecting the degree of ordering in nonstoichiometric (Fe, Ni)Al alloys with less
than 50 at. pct aluminum. 相似文献
100.
Selective ion exchange is one of the preferred treatment technologies for removing low levels of perchlorate (ClO4-) from contaminated water because of its high efficiency and minimal impact on water quality through the addition or removal of chemicals and nutrients. However, the exceptionally high affinity of ClO4- for type I anion-exchange resins makes regeneration with conventional NaCl brine extremely difficult and costly for practical applications. The present study entails the development of a novel regeneration methodology applicable to highly selective anion-exchange resins. Tetrachloroferrate (FeCl4-) anions, formed in a solution of ferric chloride and hydrochloric acid (e.g., 1 M FeCl3 and 4 M HCl), were found to effectively displace Cl04- anions that were sorbed on the resin. A mass-balance analysis indicated that a nearly 100% recovery of ion-exchange sites was achieved by washing with as little as approximately 5 bed volumes of the regenerant solution in a column flow-through experiment There was no significant deterioration of the resin's performance with respect to ClO4- removal after repeated loading and regeneration cycles. Thus, the new methodology may offer a cost-effective means to regenerate ClO4- -loaded resins with improved regeneration efficiency, recovery, and waste minimization in comparison with conventional brine regeneration techniques. 相似文献