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21.
In this article we propose efficient scan path and BIST schemes for RAMs. Tools for automatic generation of these schemes have been implemented. They reduce the design effort and thus allow the designer to select the more appropriate scheme with respect to various constraints. 相似文献
22.
R Pratesi L Gandolfi H Friedman L Farage CA de Castro C Catassi 《Canadian Metallurgical Quarterly》1998,33(8):817-821
BACKGROUND: Our objective was to determine the possible presence of IgA antibodies directed against human central nervous system (CNS) structures in sera from coeliac disease (CD) patients. METHODS: Serum samples were collected from 4 patients with active CD on a gluten-containing diet, 11 biopsy-proven CD patients on a gluten-free diet (GFD), and 52 non-coeliac gastrointestinal controls. In all patients IgA antigliadin antibody (AGA) titres were determined with enzyme-linked immunoassay (ELISA), and IgA antiendomysium antibodies (EMA) with indirect immunofluorescence on human umbilical cord. Cryostat sections of human brain occipital cortex were incubated with the patients' sera and subsequently labelled with anti-human IgA fluorescein conjugate. RESULTS: All sera from patients with active CD on a gluten-containing diet yielded positive results in both the IgG-AGA and EMA test and in indirect immunofluorescence on brain tissue, disclosing a strong fluorescence over blood-vessels structures. All sera from CD patients on a GFD and from non-coeliac gastrointestinal controls gave a negative result on both the EMA test and the immunofluorescence reaction on human brain. CONCLUSIONS: Sera from patients with active CD contain IgA antibodies that react with human brain vessel structures, giving intense fluorescence. These antibodies are not present in sera from coeliac patients on a GFD or non-coeliac controls. This finding might be involved in the abnormal nervous system manifestations frequently described in association with coeliac disease. 相似文献
23.
Joaquim J. Barroso Pedro J. Castro Joaquim P. Leite Neto 《Journal of Infrared, Millimeter and Terahertz Waves》2003,24(1):79-86
We present a method for measuring the electrical conductivity of metallic materials that relies on the ratio of two loaded Q factors, QR/QX, with QR corresponding to a TE011-mode reference cavity made of aluminum, and QX the Q that results upon replacing the aluminum plate with the one fabricated from the material to be examined. Electrical conductivity is mathematically inferred from the ratio QR/QX where the loaded Q factors are measured by using the transmission-type method. Within a 3.0 percent accuracy, conductivities determined at 8.7 GHz for electrolytic copper (5.6 times 107 S/m) and brass (1.6 times 107 S/m) show to be in good agreement with those reported in the literature. 相似文献
24.
The effect of aluminium on the equilibrium phases of the Cu-Zn alloys has been studied within the range of chemical compositions
of interest to brass producers. Ternary alloys were cast by melting two Cu-Zn base alloys (with ∼59.5% and ∼61.2 wt.% Cu)
followed by the addition of aluminium up to 3.68 wt.%. Isothermal homogenization, followed by rapid cooling, has been used
to determine the equilibrium phases at different temperatures. The alloys have been observed by scanning electron microscopy
(SEM) and the respective chemical analysis determined by electron probe microanalysis (EPMA). Statistical analysis of the
results enables a correlation of the chemical compositions of the equilibrium phases with temperature within composition range
of the study. 相似文献
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27.
Michael Rabinovich Kate L. Olsavsky Burr Leach Mauricio Cabrera‐Ríos José M. Castro 《应用聚合物科学杂志》2008,109(4):2465-2471
Sheet molding compound (SMC) is a fiber‐reinforced polymeric composite. It is often used in automotive, marine, and industrial applications over other materials because of its high strength to density ratio, resistance to corrosion, and low cost. There is a demand in the SMC industry to be able to characterize SMC processability. This is particularly true for heavy truck body panels, one of the fastest growing applications of SMC. Because of their large size and high strength requirement, the molding forces have a major influence in the molding cycle. Also because of the long flow paths involved, the ability of the paste to carry glass needs to be properly characterized when developing new SMC materials. In this article, we demonstrate the benefits of using spiral flow as a processability tester. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
28.
This paper analyzes a system subject to repairable and non-repairable failures. Non-repairable failures lead to replacement of the system. Repairable failures, first lead to repair but they lead to replacement after a fixed number of repairs. Operating and repair times follow phase type distributions (PH-distributions) and the pattern of the operating times is modelled by a geometric process. In this context, the problem is to find the optimal number of repairs, which maximizes the long-run average reward per unit time. To this end, the optimal number is determined and it is obtained by efficient numerical procedures. 相似文献
29.
S. B. S. D. Castro 《Dynamical Systems: An International Journal》1995,10(1):13-31
We prove several results concerning problems invariant under the action of an arbitrary compact Lie group Γ. These include the existence of mixed-mode solutions and secondary Hopf bifurcations. We provide a definition of mode interaction which applies to a wide selection of problems and consider the unfolding of the equations characterizing such problems. Where appropriate, we distinguish the case when I acts trivially on one of the modes 相似文献
30.
A. T. Sousa P. S. Fialho C. A. Nieto de Castro R. Tufeu B. Le Neindre 《International Journal of Thermophysics》1996,17(3):551-560
The density of HCFC 141b has been measured at several temperatures between 260 and 320 K, Mid pressures up to 20 MPa, with a mechanical oscillator densimeter. The densimeter was calibrated with 2,2,4-trimethylpentane, whose density was obtained from a correlating cyuation with 0.3% uncertainty. The density data obtained for HCFC 14H) hits a reproducibility of 0.05% and an uncertainty of 0.3%. The data obtained were fitted to a Tait-type equation. which reproduced the experimental densities within 0.11 % and were compared with the data obtained in other works.Paper presented at the Twelfth Symposium on Thermophysical Properties, June 19–24, 1994, Boulder, Colorado, U.S.A. 相似文献