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91.
Majid Ramezani Mahdi Bashiri Anthony C. Atkinson 《Expert systems with applications》2011,38(8):9557-9563
Multiple response problems include three stages: data gathering, modeling and optimization. Most approaches to multiple response optimization ignore the effects of the modeling stage; the model is taken as given and subjected to multi-objective optimization. Moreover, these approaches use subjective methods for the trade off between responses to obtain one or more solutions. In contradistinction, in this paper we use the Prediction Intervals (PIs) from the model building stage to trade off between responses in an objective manner. Our new method combines concepts from the goal programming approach with normalization based on negative and positive ideal solutions as well as the use of prediction intervals for obtaining a set of non-dominated and efficient solutions. Then, the non-dominated solutions (alternatives) are ranked by the TOPSIS (Technique for Order Preference by Similarity to the Ideal Solution) approach. Since some suggested settings of the input variables may not be possible in practice or may lead to unstable operating conditions, this ranking can be extremely helpful to Decision Makers (DMs). The consideration of statistical results together with the selection of the preferred solution among the efficient solutions by Multiple Attribute Decision Making (MADM) distinguishes our approach from others in the literature. We also show, through a numerical example, how the solutions of other methods can be obtained by modifying the relevant approach according to the DM’s requirements. 相似文献
92.
Majid Aryafar Ramin Raiszadeh Alireza Shalbafzadeh 《Journal of Materials Science》2010,45(11):3041-3051
The possibility of the bonding of the two layers of a double oxide film defect when held in liquid A356 Al alloy was investigated.
The defect was modelled experimentally by maintaining two aluminium oxide layers in contact with each other and the atmosphere
trapped between them in the A356 liquid alloy for varying lengths of time of between 30 s and 48 h. Any changes in the composition
and morphology of these layers were studied by SEM, EDX and XRD. The results showed that the two layers of a double oxide
film defect might bond to each other by two different mechanisms, one during the transformation of Al2O3 to MgAl2O4 spinel in relatively short holding times, which would cause the layers to bond at several points and the other during the
gradual transformation of spinel to MgO in longer times, which would cause strong bonding between the layers. It was shown
that any bonding can take place essentially only after the oxygen and nitrogen of the atmosphere within the defect are consumed. 相似文献
93.
A finite-element approach is used to analyze the slope stability problem and to examine the effect of soil dilatancy on the stability of slopes. It is found that soil dilatancy has a significant effect on the stability of slopes, and that higher values of dilation angle lead to larger stability numbers. Therefore, the stability numbers obtained from limit analyses (lower∕upper bound solutions) are not conservative for granular soils that exhibit a dilation angle smaller than a soil's friction angle. 相似文献
94.
95.
This work investigates the possibility of utilizing the µp-8085 and its application to concrete crack depth evaluation. For the purpose of the nondestructive testing, ultrasonic pulses are of importance in assessing the quality of concrete as well as flaw detection and measurement. This will be useful in repairing concrete columns. 相似文献
96.
T. S. Velayutham W. H. Abd Majid A. B. Ahmad Yik Kang Gan Seng Neon Gan 《应用聚合物科学杂志》2009,112(6):3554-3559
Three different polyester polyols, with various oleic acid content, were used in the preparation of polyurethane (PUR) coatings. The polyols were designated as Alk28, Alk40, and Alk65, in which 28, 40, and 65 represent the percentage of oleic acid of the polyol formulations. These polyester polyols were reacted with aromatic diisocyanate [toluene diisocyanate (TDI)] to form PUR coatings. The acid value, hydroxyl value, molecular weight, and viscosity of the polyols have been determined. The reaction between the polyols and TDI was studied by Fourier Transform Infrared spectroscopy and X‐ray diffraction (XRD). The effects of varying NCO/OH ratio and oleic acid content of polyols on physical and mechanical properties of PUR films were studied. XRD results indicate that the samples are amorphous. PURs, made with Alk28, have the best mechanical properties followed by Alk40 and Alk65. The mechanical properties of the samples have increased as the NCO/OH ratio was increased from 1.2 to 1.6. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
97.
Synthesis of thioglycerol capped zinc selenide nanoparticles with a relatively narrow size distribution by a simple and inexpensive low temperature (~ 80 °C) wet chemical method is reported here. Main advantage of this method is the use of non-toxic precursors. The size of the nanoparticles can be varied easily by changing the concentration of the capping agent. The extracted nanoparticles remain stable under normal atmospheric conditions and can be redispersed in suitable solvents. The sharp absorption features obtained in the UV-Visible absorption spectra reveal the formation of monodispersed ZnSe nanoparticles. The nanoparticles were characterized using X-ray photoelectron spectroscopy, X-ray diffraction, UV-Visible absorption spectroscopy, photoluminescence and transmission electron microscopy. 相似文献
98.
The optical response of materials based on gold nanoparticle assemblies depends on many parameters connected to both material
morphology and light excitation characteristics. The optical energy absorbed is then converted into heat through different
nanoscale energy exchange mechanisms. This heating subsequently modifies itself the optical properties. We investigate the
interplay between the optical and thermal responses of nanocomposite media under its theoretical aspect. In this first paper,
the thermal response of gold nanoparticle assemblies under pulsed optical excitation is considered. Both conventional and
original modelling approaches are presented. We first underline the role of electromagnetic interactions between particles
in a dense assembly in its linear optical response. We then show how the interaction of light with matrix-embedded gold nanoparticles
can result in the generation of thermal excitations through different energy exchange mechanisms. Finally, we demonstrate
the possible significant influence of the heat carrier ballistic regime and phonon rarefaction in the cooling dynamics of
an embedded gold nanoparticle subsequent to ultrafast pulsed laser excitation. 相似文献
99.
Mohsen Vafaie-Sefti Hamid Modarress Majid Emami Meibodi Seyyed Ali Mousavi-Dehghani 《加拿大化工杂志》2007,85(1):65-74
An association equation of state (AEOS) has been proposed for hydrogen-bonded compounds. To obtain this AEOS, the compressibility factor was assumed to consist of two parts: the physical part due to physical interactions of molecules; and the chemical part due to molecular association by hydrogen bonding of molecules. The physical part of the compressibility factor was represented by the MMM EOS for non-polar compounds proposed by Mohsen-Nia et al., Fluid Phase Equilib. 206 , 27-39 (2003), and the chemical part of the compressibility factor was deduced by proposing a molecular association model of infinite series. 相似文献
100.
The two-dimensional dynamic interaction of progressive plane seismic waves with an arbitrarily thick, isotropic, and functionally graded cylindrical shell of infinite extent embedded in a boundless fluid-saturated porous elastic medium is investigated. The inhomogeneous shell is approximated by a laminate model, for which the solution is expected to gradually approach the exact one as the number of layers increases. Continuity of the displacement and stress components at the interfaces of neighboring layers is applied to form a system global transfer matrix, ultimately leading to determination of the modal scattering and transmission coefficients. The analytical results are illustrated with numerical examples in which an air-filled steel–zirconia FGM shell, buried in a water-saturated Ridgefield Sandstone formation, is insonified by fast compressional or shear waves at normal incidence. The effects of material compositional gradient and FGM layer thickness on the basic dynamic field quantities are evaluated and discussed. Limiting cases are considered and good agreements with the solutions available in the literature are obtained. 相似文献