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101.
Salim A. Messaoudi Muhammad I. Mustafa 《Nonlinear Analysis: Theory, Methods & Applications》2010,72(9-10):3602-3611
In this paper we consider a viscoelastic equation with a nonlinear feedback localized on a part of the boundary. We establish an explicit and general decay rate result, using some properties of the convex functions. Our result is obtained without imposing any restrictive growth assumption on the damping term and strongly weakening the usual assumptions on the relaxation function. 相似文献
102.
The viscosity index (VI) and the base number (BN) of motor oils are the most important parameters to be measured in order to assess their performance and service time. Both parameters were simply obtained for virgin and recycled motor oil samples using multivariate calibration based on the FTIR data. Analysis showed that the PLS-1 has outperformed CLS and PCR for the oil parameters prediction. Five and four PLS-1 latent variables were found optimum to obtained the VI and the BN from the FTIR data; respectively. With high accuracy (99-102%) and precision (3-11%), the BN could be determined over the range 4.57-16.45 mg KOH g−1 and the VI over the range 96-153. The outputs of the PLS-1 were found comparable to those obtained by the expensive and time-consuming ASTM methods. This developed method is highly recommended for quick monitoring of the motor oil quality parameters. 相似文献
103.
Morad Alizadeh Fazlollah Lak Mahdi Rasekhi Thiago G. Ramires Haitham M. Yousof Emrah Altun 《Computational Statistics》2018,33(3):1217-1244
We introduce a new class of distributions and provide a comprehensive treatment of its mathematical properties. The maximum likelihood method is discussed to estimate the parameters of the new model by means of Monte-Carlo simulation study. The heteroscedastic regression models with long-term survival are introduced to model data sets with the non homogeneity of the error variances in the presence of cured individuals. The potentiality of the proposed models is illustrated by means of four real data sets. 相似文献
104.
Mohammad Kafini Salim A. Messaoudi Serge Nicaise 《NoDEA : Nonlinear Differential Equations and Applications》2016,23(2):13
In this paper we consider a second-order abstract evolution system with delay. We show that, under suitable conditions on the initial data and the involved functionals, the energy of solutions blows up in finite-time. We also give some concrete examples to illustrate our main result. 相似文献
105.
Atsushi Narumi Sylvia Zeidler Haitham Barqawi Claudia Enders Wolfgang H. Binder 《Journal of polymer science. Part A, Polymer chemistry》2010,48(15):3402-3416
A cyclic initiator for the nitroxide‐mediated controlled radical polymerization (NMP) is a powerful tool for the preparation of macrocyclic polymers via a ring‐expansion vinyl polymerization mechanism. For this purpose, we prepared a Hawker‐type NMP‐initiator that includes an azide and a terminal alkyne as an acyclic precursor, which is subsequently tethered via an intramolecular azide/alkyne‐“click”‐reaction, producing the final cyclic NMP‐initiator. The polymerization reactions of styrene with cyclic initiator were demonstrated and the resultant polymers were characterized by the gel permeation chromatography (GPC) and the matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS). These results prove that the ring‐expansion polymerization of styrene occurred together with the radical ring‐crossover reactions originating from the exchange of the inherent nitroxides generating macrocyclic polystyrenes with higher expanded rings. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3402–3416, 2010 相似文献
106.
Mofeed Turky Rashid Mattia Frasca Abduladhem Abdulkareem Ali Ramzy Salim Ali Luigi Fortuna Maria Gabriella Xibilia 《Nonlinear dynamics》2012,68(4):555-563
Artemia larvae may show swarming organization under the presence of a light spot, while being insensitive to several other external stimuli. In this paper, the dynamics of the Artemia population in response to this kind of stimuli has been exploited to design a robot moving inside the water and able to lead the direction of the group. The robot therefore implements external leadership, by driving the Artemia population along a set of desired trajectories. Experimental results and simulations based on a model of Artemia motion confirmed the suitability of the approach. 相似文献
107.
108.
Richard A. Hollins Luiz A. Colnago Vera M. Salim Michael C. Seidl 《Journal of heterocyclic chemistry》1979,16(5):993-996
The thallation-iodination of 3-carbonylindoles ( 4a-f ) results in orientation control with substitution occurring at the 4-position ( 6a-f ). Also described is the dithallation of N-methylpyrrole-2-carboxaldehyde ( 2 ). 相似文献
109.
Mustafa M. El‐Abadelah Salim S. Sabri Monther A. Khanfar Hani A. Yasin Wolfgang Voelter 《Journal of heterocyclic chemistry》2002,39(5):1055-1059
The synthesis and spectral properties (ir, ms, nmr) of a substituted 2‐methyl‐2H‐pyrazolo[4,3‐d]‐pyrimidin‐7‐one ( 3 ), an isomer of Viagra®, are described. The key synthon, 4‐amino‐1‐methyl‐5‐propyl‐3‐pyrazolecarboxamide ( 7 ), is prepared via the reaction of ethyl 2,4‐dioxoheptanoate with methylhydrazine, followed by cyclization, nitration, amidation, and nitro group reduction. Interaction of 7 with 2‐ethoxyben‐zoyl chloride yielded the respective bis‐amide ( 8 ) which was cyclized in polyphosphoric acid to the corresponding pyrazolo[4,3‐d]pyrimidin‐7‐one derivative 9 . Chlorosulfonylation of 9 , and subsequent treatment with 1‐methylpiperazine furnished iso Viagra ( 3 ). 相似文献
110.
Mathematical models have been developed to optimize three configurations for membrane gas separation modules. The three systems include the single stage, the two stage, and the continuous membrane column (CMC). Analysis of the three systems is carried out for the case of enriching a binary mixture of methane and carbon dioxide, where the reject stream is the desired product. The cost optimization function includes the capital cost for compressors and membranes as well as the energy operating cost. The cost function is solved subject to a set of equality and inequality constraints. The equality constraints include the module balance equations and the permeation fluxes across the membrane. The inequality equations include constraints on mole fractions in permeate and reject streams, operating pressure, membrane area, and the amount of methane recovered in reject stream. Model equations for the three systems are solved using GINO, a program for nonlinear optimization. A quasi-Newton search method is selected and found quite efficient for solution of the equations. Over the range of parameters considered in the analysis, results show that the two stage configuration has a lower production cost than the other two systems. In addition, the operating cost for the CMC and the single stage systems are found to be comparable. Irrespective of this, the optimum amount of methane recovered is the highest for the CMC system. Although the optimum operating costs for the CMC and the single stage systems are higher than the two stage system, comparison should consider other factors including higher methane recoveries generated by the CMC system and the simplicity of design and operation for the single stage system. 相似文献