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141.
In this study, pure rhodium was fabricated and mechanically investigated at the nanoscale for the first time. The nanopillars approach was employed to study the effects of size on the yield point. Nanopillars with different diameters were fabricated using electroplating followed by uniaxial compression tests. Scanning electron microscopy (SEM) was used as a quality control technique by imaging the pillars before and after compression to ensure the absence of cracks, buckling, barrelling or any other problems. Transmission electron microscopy and SEM were used as microstructural characterization techniques. Due to substrate-induced effects, only the plastic region of the stress–strain curves were investigated, and it was revealed that the yield point increases with size reduction up to certain limit, then decreases with further reduction of the nanopillar size (diameter). The later weakening effect is consistent with the literature, which demonstrates the reversed size effect (the failure of the plasticity theory) in nanocrystalline metals, i.e. smaller is weaker. In this study, however, the effect of size reduction is not only weakening, but is strengthening-then-weakening, which the authors believe is the true behavior of nanocrystalline materials. 相似文献
142.
Omar Hussain Tharam Dillon Farookh Khadeer Hussain Elizabeth Chang 《Simulation Modelling Practice and Theory》2011,19(2):704-717
Business activities are a result of carefully formed associations between different users in order to achieve certain pre-decided outcomes. Decision-making in such associations is an important step and transactional risk analysis is one of the integral processes that facilitates this step. This paper presents an approach that determines the negative consequences (termed as financial risk) of forming e-business associations. Unlike other approaches, our model captures the different types of events and their uncertainties to determine the financial risk by using the convolution operator and expressing it as a probabilistic measure rather than as a crisp financial value. Such representation makes sense as the financial risk may be determined at a point of time in future where nothing is certain. Depending upon the complexity of the problem, we explain the different ways of using the convolution operator to determine the financial risk. The simulation result shows a better representation and understanding of the financial risk that will provide important inputs to the transactional risk analysis and the decision-making process. 相似文献
143.
Miguel Ángel Vélez Omar Sánchez Sixto Romero José Manuel Andújar 《Applied Soft Computing》2010,10(2):578-591
The present paper puts forward a methodology which allows increasing interpretability of TSK models identified by means of neuro-fuzzy techniques, although it shall also be applicable to models identified through other hybrid or different techniques. With this purpose, this paper puts forward a method which allows oriented adjustment of the rules’ precedent and consequent parameters in TSK models. The methodology extends the adaptive phase with an adjustment phase (or fine tuning phase) based on overlap ratio and overlap area, where the gradient descendent algorithm is used to adjust precisely the adapted parameters in the fuzzy model. The adjustment based on the overlap ratio is applied to the parameters defining the rules’ precedent and consequent parts. The overlap area becomes a more precise tuning of parameters of precedent part of rules. After the adaptation of the neuro-fuzzy model by means of the developed methodology, the model acquires a clear physical meaning enabling its immediate linguistic interpretation. Finally, some examples are given to prove the validity of the developed methodology. 相似文献
144.
Omar Bouattane Bouchaib Cherradi Mohamed Youssfi Mohamed O. Bensalah 《Parallel Computing》2011,37(4-5):230-243
In this paper, we propose a parallel algorithm for data classification, and its application for Magnetic Resonance Images (MRI) segmentation. The studied classification method is the well-known c-means method. The use of the parallel architecture in the classification domain is introduced in order to improve the complexities of the corresponding algorithms, so that they will be considered as a pre-processing procedure. The proposed algorithm is assigned to be implemented on a parallel machine, which is the reconfigurable mesh computer (RMC). The image of size (m × n) to be processed must be stored on the RMC of the same size, one pixel per processing element (PE). 相似文献
145.
M Stucki R Moudry C Kempf A Omar A Schlegel PG Lerch 《Canadian Metallurgical Quarterly》1997,700(1-2):241-248
A chromatographic fractionation method has been developed for the production of a liquid-stable anti-D immunoglobulin product for intravenous and intramuscular use. An immunoglobulin fraction, highly enriched with anti-D immunoglobulins, was isolated by cation-exchange column chromatography and further polished, first by anion-exchange chromatography, followed by an aluminium hydroxide gel treatment. The process includes two specific steps for virus inactivation and removal, namely S/D treatment and nanofiltration. The overall anti-D process yield is about 56%. The final product is stabilised with human albumin and glycine and placed in ready-to-use syringes. The anti-D product was shown to be stable in liquid state for at least 30 months at 4 degrees C. 相似文献
146.
Price Rumi Kato; Spitznagel Edward L.; Downey Thomas J.; Meyer Donald J.; Risk Nathan K.; El-Ghazzawy Omar G. 《Canadian Metallurgical Quarterly》2000,12(1):40
Because psychological assessment typically lacks biological gold standards, it traditionally has relied on clinicians' expert knowledge. A more empirically based approach frequently has applied linear models to data to derive meaningful constructs and appropriate measures. Statistical inferences are then used to assess the generality of the findings. This article introduces artificial neural networks (ANNs), flexible nonlinear modeling techniques that test a model's generality by applying its estimates against "future" data. ANNs have potential for overcoming some shortcomings of linear models. The basics of ANNs and their applications to psychological assessment are reviewed. Two examples of clinical decision making are described in which an ANN is compared with linear models, and the complexity of the network performance is examined. Issues salient to psychological assessment are addressed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
147.
Omar M. Atrooz 《International Journal of Food Science & Technology》2008,43(3):490-494
The effects of Maillard reaction products (MRPs) on apple and potato polyphenol oxidase (PPO) were estimated spectrophotometrically. Model systems of glucose and amino acids [lysine (lys), tyrosine (tyr), proline (pro), cysteine (cys), glumatic acid (glu), aspartic acid (asp), and histidine (his)] were heated at 90 °C for 3 h. The MRPs showed inhibitory effects on PPO extracted from apple and potato. These effects depend on the type of MRP and origin of PPO. The antioxidant activity of MRPs was evaluated. It was found that MRPs exhibit different free radical scavenging activity and these effects were significant. The colour intensity of MRPs was estimated. Browning was not directly related to the antioxidant activity. 相似文献
148.
In recent years, numerous investigations have addressed the shear strengthening of reinforced concrete (RC) beams with externally bonded fiber-reinforced polymer (FRP) composites. Despite this research effort, the mechanisms of shear resistance that are developed in such a strengthening system have not yet been fully documented and explained. This clearly inhibits the development of rational and reliable code specifications. This paper aims to contribute to the understanding of the shear resistance mechanisms involved in RC beams strengthened in shear with externally bonded FRP. It is based on results obtained from an experimental program, involving 17 tests, performed on full size T beams, and using a comprehensive and carefully optimized measuring device. The resistance mechanisms are studied by observing the evolution of the behavior of the strengthened beams as the applied loads are increased. The local behavior of the FRP and the transverse steel, in particular in the failure zones, are thoroughly examined. The operative resistance mechanisms are also studied through the load sharing among the concrete, the FRP, and the transverse steel, at increasing levels of applied load. 相似文献
149.
Waschbusch Daniel A.; Porter Stephen; Carrey Normand; Kazmi S. Omar; Roach Kerry A.; D'Amico Delia A. 《Canadian Metallurgical Quarterly》2004,36(2):97
We evaluated parent and teacher ratings of a large sample (N=1579) of elementary-school children in Canada to determine how different conceptualizations of disruptive behaviour are co-related and related to other measures of functioning. Parent and teacher ratings were consistent, and suggested three separate but correlated aspects of disruptive behaviour in children: (1) reactive/oppositional behaviour, (2) proactive/callous behaviour; and (3) inattention-impulsive-overactive behaviour. These were uniquely and significantly related to DSM-IV diagnostic scores and to other measure of impairment, indicating that they measure distinct aspects of disruptive behaviour in children. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
150.
Peter Bettess Joseph Shirron Omar Laghrouche Bernard Peseux Rie Sugimoto Jon Trevelyan 《International journal for numerical methods in engineering》2003,56(4):531-552
The theory for integrating the element matrices for rectangular, triangular and quadrilateral finite elements for the solution of the Helmholtz equation for very short waves is presented. A numerical integration scheme is developed. Samples of Maple and Fortran code for the evaluation of integration abscissæ and weights are made available. The results are compared with those obtained using large numbers of Gauss–Legendre integration points for a range of testing wave problems. The results demonstrate that the method gives correct results, which gives confidence in the procedures, and show that large savings in computation time can be achieved. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献