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2.
Work has been done on the molten ternary system U-Th-Sn to provide a selective nitriding separation scheme. The nitride formation reaction has been studied as a function of temperature (1490° to 1700°C) and weight percent of U/Th in Sn, using a Sievert's-type apparatus. Nitride formation has been demonstrated in a U-Th-Gd system. 相似文献
3.
The paper describes the practical uses of two-dimensional (2-D) fc-step-ahead self-tuning prediction algorithms. Two distinct application areas are considered. The first concerns direct prediction/forecasting, applied to data with a strong periodic (or 'seasonal’) component. The second concerns the prediction of data from spatial scanning sensors or spatial sensor arrays. In both cases, the original data is usually one-dimensional in nature. The contribution of the paper is to show how, by treating the data as if it were two-dimensional in nature, a vast improvement in the quality of predictions is obtained. Moreover, because the 2-D predictors are self-tuning, the algorithms require virtually no user intervention and no prior filtering or pre-processing of the data. 相似文献
4.
RAFAEL SCAF DE MOLON MARTA MARIA ALVES PEREIRA ERICA DORIGATTI DE AVILA 《Biocell》2022,46(5):1151-1156
It has been recognized that physical and chemical properties of biomaterial surfaces mediate the quality of extracellular matrix (ECM) that may affect cell behaviors. In nature, ECM is a heterogeneous three-dimensional superstructure formed by three major components, glycosaminoglycan, glycoconjugate, and protein, that anchors cellular compartments in tissues and regulates the function and the behavior of cells. Changes in the biointerface alter the quality of ECM and morphology through cell surface receptors, which, in turn, enable it to trigger specific cell signaling and different cellular responses. In fact, a number of strategies have been used to improve the functionality of surfaces and direct cell behavior through precisely designed environments. Herein, we aimed to discuss, through a science-based viewpoint, the biomaterial surface features on cell behavior and analyze the impact of cell physical modification on dental implant development. 相似文献
5.
A problem consisting of the optimal design of a segmented wall on a surface having a nonlinear slope contour is considered. It is formulated as an optimal control problem and a solution procedure based on the Discrete Maximum Principle is developed. An application to a real case, which previously had been solved by a Dynamic Programming based method, is included together with some critical comments on the above-mentioned technique. 相似文献
6.
PATRICIA L. ALVES DE LIMA DANIEL A RIBEIRO MARINA M SUGUI ANA PAULA TEREZAN MARIA APARECIDA C DOMINGUES E R FILHO LUCIANA AZEVEDO DAISY M F SALVADORI LUCIA R RIBEIRO 《Journal of Food Biochemistry》2010,34(1):206-228
In this study, we have investigated the stability of the antigenotoxic properties of dried of Lentinula edodes (Berk.) Singer mushroom powder stored at room and at − 20C. Mice were pretreated by gavage for 15 consecutive days with 0.6 mL/day of an aqueous extract of dried L. edodes powder prepared at 60C. On day 15, the mice were intraperitoneally injected with 50 mg/kg N-ethyl-N-nitrosourea (ENU); 3 h later, peripheral blood was withdrawn from the animals and used to evaluate DNA damage using the comet assay. The mice were sacrificed 24 h after the ENU treatment and the bone marrow used to measure the frequency of micronucleated polychromatic erythrocytes. The results indicated that storage at both room temperature and at − 20C significantly reduced the antigenotoxic effects of the mushroom powder. In addition, whereas freshly dried mushroom powder was nongenotoxic, storage of the powder at − 20C resulted in genotoxic activity ( P < 0.05). Taken together, our data indicate that constituents of L. edodes powder are altered during storage, resulting in both genotoxicity and a reduction in antigenotoxicity. 相似文献
7.
This paper presents a fuzzy algorithmic approach to the construction of composite indices. The method uses a fuzzy analytic translation of a linguistic definition of the composite index, where the definition involves more primary concepts for which scales already exist. An application to the construction of a functional limitation index is presented. Comparisons between the fuzzy algorithmic approach and a more standard, tabular approach are also shown. The results suggest that the fuzzy algorithmic approach yields essentially the same index with less effort and some conceptual advantages. 相似文献
8.
DONALD H. HAMMOND STEPHEN M. CROW SANDRA J. HARTMAN 《International journal of systems science》2013,44(11):2255-2260
Clark et al ( 1992)reported on the use of a computer simulation model to show that significant reduction in customer ‘ waiting time’ could be achieved by new management policies for multi-station service organizations. They modelled a multi-phase queuing structure and showed reductions in the system variable ‘ time in system’ when servers were pooled at the first reception desk, rather than having single servers at multiple desks to provide service. Their model also demonstrated a greater savings in system transit time when the servers moved with the customers through subsequent tasks (multi-phase systems) This paper uses classical queuing theory to evaluate these results. We conclude that Clark et al' s findings can be supported through use of the classical waiting line formulas. 相似文献
9.
MARIA PIA FANTI BRUNO MAIONE BIAGIO TURCHIANO 《International journal of control》2013,86(6):2523-2542
Linear positive systems are utilized in various scientific areas such as economic modelling, behavioural science, stochastic processes etc. A recent study has focused on some sufficient conditions for the controllability of these systems. A full characterization is provided of the controllability for discrete-time single-input positive systems. Necessary and sufficient conditions are derived using a digraph-theoretic approach. The main results show that strong constraints are to be imposed on the digraph associated with the pair (A, b) to ensure the controllability of the system. 相似文献
10.
SANDRA L. HOUSTON WILLIAM N. HOUSTON J. MANUEL PADILLA 《Computer-Aided Civil and Infrastructure Engineering》1987,2(3):207-222
Ageotechnical engineering microcomputer program has been developed for the determination of permanent slope displacements resulting from earthquake shaking. The Newmark procedure, in which accelerations in excess of yield accelerations are double integrated to obtain displacements, has been incorporated into the program DISPLMT. Several user options are available for describing the yield acceleration function, including variation with time and variation with displacement. Screen graphics are available which allow the user to observe the down slope movements of the Newmark sliding block as they increase with time during the simulated earthquake. DISPLMT has been used to calculate the permanent movements of an earth dam using acceleration-time histories and soil shear stresses determined from a separate analysis. Modification to the conventional Newmark procedure, by introduction of a "slip layer," has been made in the analysis of a dam. Permanent slope displacements can be analyzed using the recommended procedure, which involves fairly simple computations that can be performed in a reasonable period of time with the exclusive use of microcomputers. 相似文献