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101.
Blends of polypropylene (PP) and acrylonitrile butadiene rubber (NBR) were prepared with different weight compositions with a plasticorder at 180°C at a rotor speed of 60 rpm for 8 min. The physicomechanical properties and mass swell of the prepared blends were investigated with special reference to the effects of the blend ratio. The prepared epoxidized linseed oil (EL) (i.e., E0.5L, E1L, E1.5L, and E2L using 0.5, 1, 1.5, and 2 mol H2O2/mole of unsaturation in linseed oil) and maleic acid anhydride (MAH) were melt mixed in various contents (i.e., 1, 5, 10, and 15 wt %) with a PP/NBR blend with a weight ratio of 70/30 and used as compatibilizers. The effect of the compatibilizer contents on the physicomechanical properties and mass swell of the binary blend was investigated. With an increase in the compatibilizer content up to 10 wt %, the blend showed an improvement in the physicomechanical properties and reduced mass swell in comparison with the uncompatibilized one. The addition of a compatibilizer beyond 10 wt % did not improve the blend properties any further. The efficiency of the compatibilizers (10 wt %) was also evaluated by studies of phase morphology (scanning electron microscopy). © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   
102.
The vibrations of a thermoelastic beam subject to a sudden heat input are damped by active control. The control objective is specified as the minimization of a quadratic functional in terms of displacement and velocity at a given time. The control is exercised by means of point actuators which are placed so as to minimize the maximum actuator force. The solution of the control problem is obtained by means of eigenfunction expansions. The physical problem corresponds to the suppression of vibrations of a structure suddenly entering into the daylight zone. Numerical results indicate that the displacement and velocity of the beam can be effectively reduced by means of active control exercised by point actuators.  相似文献   
103.
Alpha-feto-protein (AFP) is the most popular tumor marker for hepatocellular carcinoma (HCC). It is used in diagnosis and follow up of cases by estimating its rise in the serum. The aim of this work is to study the value of estimating AFP in ascitic fluid of HCC patients with ascites. This work is a case control study on 32 patients, including 22 cases with ascites and HCC and 10 control group with ascites due to liver cirrhosis without HCC. The level of AFP was estimated in serum and in ascitic fluid by Radio-immuno assay RIA. The serum ascites albumin gradient (SAAG) was assessed by measuring albumin in all samples using bromocresole green dye binding. Guided aspiration liver biopsy and ascitic fluid cytology was done, stained with H & E. It was found that, AFP level in serum was elevated in 72.7% of HCC patients, and in ascitic fluid was elevated 63.6% HCC patients. Also, there was a highly significant, direct positive correlation between elevation of AFP in serum and in ascitic fluid (r = 0.778). No elevation of AFP in serum and in ascitic fluid was detected in control group. Ascitic fluid cytology showed malignant cells in one case only. SAAG was significantly lower in the HCC group 0.83 gm/dl than the control group 2.43 gm/dl (p-value < 0.001). Elevation of AFP in ascitic fluid is of high importance in evaluation of HCC, and is as significant as serum and runs parallel to it. Estimation of AFP in ascitic fluid is much more significant in evaluation of HCC cases than ascitic fluid cytology.  相似文献   
104.
Optimal major and minimal maintenance policies for deteriorating systems   总被引:7,自引:2,他引:5  
We present a maintenance model for a multi-state semi-Markovian deteriorating system. Our model allows one of three maintenance decisions (do-nothing, minimal maintenance or replacement) to be taken at each state of the system. We use control limit policy and the policy-iteration algorithm to find the optimal maintenance policies that minimizes the expected long-run cost rate of the system. Numerical examples are given to illustrate the proposed policies.  相似文献   
105.
成熟区岩性油气藏勘探再认识   总被引:1,自引:1,他引:0  
大港油田历经40多年的勘探,已经进入成熟区岩性油气藏勘探阶段。成熟区的油源、储集、圈闭等条件均较优越,但成熟区构造及油藏关系复杂,因此成熟区勘探应采用斜坡区岩性勘探的思路和工作流程,重新认识和评价成熟区的分析研究工作,要在充分利用成熟区丰富钻井资料的基础上,开展储层精细研究,包括层序划分、岩相识别以及剖面上和平面上的储层刻画。实践证明,对成熟区岩性油气藏勘探的再认识应用效果十分明显,从而打开了成熟区勘探的新局面。  相似文献   
106.
Existing transportation planning modeling tools have critical limitations with respect to assessing the benefits of intelligent transportation systems (ITS) deployment. In this article, we present a novel framework for developing modeling tools for quantifying ITS deployments benefits. This approach is based on using case–based reasoning (CBR), an artificial intelligence paradigm, to capture and organize the insights gained from running a dynamic traffic assignment (DTA) model. To demonstrate the feasibility of the approach, the study develops a prototype system for evaluating the benefits of diverting traffic away from incident locations using variable message signs. A real–world network from the Hartford area in Connecticut is used in developing the system. The performance of the prototype is evaluated by comparing its predictions to those obtained using a detailed DTA model. The prototype system is shown to yield solutions comparable to those obtained from the DTA model, thus demonstrating the feasibility of the approach.  相似文献   
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109.
Recent research has shown that virtual agents expressing empathic emotions toward users have the potential to enhance human–machine interaction. To provide empathic capabilities to a rational dialog agent, we propose a formal model of emotions based on an empirical and theoretical analysis of the users’ conditions of emotion elicitation. The emotions are represented by particular mental states of the agent, composed of beliefs, uncertainties and intentions. This semantically grounded formal representation enables a rational dialog agent to identify from a dialogical situation the empathic emotion that it should express. An implementation and an evaluation of an empathic rational dialog agent have enabled us to validate the proposed model of empathy.  相似文献   
110.
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