Evaluation of the compactness of subbase and base geomaterials by using stiffness

Stiffness of soil that is defined as ratio of load to deflection depends on some physical properties such as compactness and water content. The purpose of this research study is to use stiffness for estimating compactness of granular geomaterials that are used as subbase and base courses of roads. In this research study, the stiffness of soil samples was determined according ASTM D6758-08 test method by using electro-mechanical device. The dry density of the compacted soil was determined by sand-cone method in the field. More than 80 laboratory and in situ tests were performed. The obtained stiffness data was used to establish a relationship between stiffness, compaction ratio and water content. The results showed that there is a strong relationship between the stiffness, compaction ratio and water content. Also, the result of validation showed that there is good correlation between in situ and laboratory tests results.     

Catalytic cracking of light naphtha over hierarchical ZSM-5 using rice husk ash as silica source in presence of ultrasound energy: Effect of carbon nanotube content

Hierarchical structured ZSM-5 was prepared by sonochemical assisted carbon nanotube templated method and their catalytic activity was examined in catalytic cracking of light naphtha. Different amounts of carbon nanotubes (5, 15, 30?wt%) was introduced into the synthesis gel, as a hard template, for mesopore creation. The rice husk ash was used as a silica source. In order to analyse physicochemical properties of synthesized catalysts, multi-techniques such as XRF, XRD, BET, FE-SEM, NH₃-TPD and TGA were used. The obtained results revealed that by adjusting the amount of carbon nanotube, catalyst properties can be favorably tuned. The XRD analysis confirmed successful synthesis of high crystalline ZSM-5 zeolite. According to the FE-SEM analysis, small rough spheres of ZSM-5 were synthesized in all samples. The use of carbon nanotube led to creating new mesopores in the ZSM-5 structure. However, increase in carbon nanotube content led to destruction of micropores of ZSM-5. The acidity of ZSM-5 slightly changed. Results from catalytic activity test showed that high catalyst stability can be achieved in presence of mesopores along with the micropores. The highest olefin yield (54?wt%) and the best catalytic stability were obtained over the synthesized ZSM-5 with 15?wt% carbon nanotube.     

Ballistic limit prediction using a numerical model with progressive damage capability

The ultimate objective of this study is to provide further understanding of the behaviour of laminated composites of varying lamina orientations and stacking sequences, when under high-velocity impact. Emphasis is placed on the determination of ballistic limits of these composites. To this end, an experimental program is carried out and a computational model, with progressive damage modeling capabilities, is developed using LS-DYNA. Experiments are performed whereby striking velocities are measured, via high-speed photography, to determine the ballistic limits of carbon fiber-reinforced polymer (CFRP) laminates of various stacking sequences. The results are reproduced closely by a numerical simulation, indicating that the numerical analysis conducted, including the choice of material model and contact definition, is an accurate means for modeling the high-speed impact characteristics of CFRP laminates. It is found that the use of static elastic and strength properties to describe the material is reasonable, since strain rate effects are found to be negligible. The kinetic energy of the projectile, plotted over the simulated impact duration, is used as the prime parameter to compare the experimental and numerical results. The numerical results accurately predict the experimental ballistic limit for six of the seven tested laminate stacking sequences. Failure due to delamination is found to play a vital role with respect to the energy absorbing ability and lamina stacking sequence of CFRP laminates.     

Moving contact lines on heterogeneous substrates

The dynamics of the deformations of a moving contact line on a disordered substrate are formulated, taking a proper account of the various interfacial forces as well as the dissipation mechanisms. Prompted by the results from dynamical renormalization group calculations, it is suggested that the coating transition in contact lines receding at relatively high velocities can be understood as a roughening transition in the contact line. A phase diagram is proposed for the system in which the phase boundaries corresponding to the coating transition and the pinning transition meet at a junction point, and suggest that for sufficiently strong disorder a receding contact line will leave a Landau-Levich film immediately after de-pinning.     

Behavior of Double-Oxide Film Defects in Al-0.05?wt pct Sr Alloy

The change in the composition of oxide layers and the possibility of the formation of bonding between the two layers of a double-oxide film defect when held in an Al-0.05?wt pct Sr melt was investigated. The defect was modeled experimentally by maintaining two aluminum oxide layers in contact with one another in the liquid metal at 1023?K (750?°C) for times ranging from 5?seconds to 50?hours. Any changes in the composition and morphology of these layers were studied by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The results showed that the A1₂O₃ layers started to transform to SrO gradually from the moment that they submerged into the melt. The transformation caused the two layers to bond with each other gradually. The results illustrated that the composition of the oxide layers of a double oxide film defect submerged in Sr-treated melt is different from that of pure Al, and this might affect the mechanical properties and the behavior of the defect in the melt significantly.     

Cesarean delivery: a randomized trial of epidural versus patient-controlled meperidine analgesia during labor

Barrett's esophagus is found in about 1% of the older population and in 3% to 5% of persons with gastroesophageal reflux. It is acquired more commonly by men and the prevalence increases with age. Most cases in the population remain undiagnosed. The incidence of adenocarcinoma of the esophagus and esophagogastric junction is increasing, both being related to Barrett's esophagus. Small areas of intestinal metaplasia are common but of uncertain significance.     

A three-stage damage detection method for large-scale space structures using forward substructuring approach and enhanced bat optimization algorithm

In this study, an efficient three-stage method is proposed for damage detection of large-scale space structures by employing forward substructuring approach, modal strain energy and enhanced bat algorithm (EBA) optimization. EBA is a modified version of BA that is proposed in this paper and used a passive congregation operator to improve the performance of standard BA. In the first stage, the global structure is divided into manageable substructures. The stiffness matrices of independent substructures are obtained based on Kron’s substructuring method. Then a modal strain energy-based index is employed to precisely locate the eventual damages of the structure. In the third stage, damage severities are estimated via EBA using the second-stage results. To demonstrate the ability of the proposed method for detection of multiple structural damages, large-scale space structures with different types of damage scenarios are considered. The results show that the proposed method can detect the exact locations and severity of damages highly accurate in space structures.

     

A randomized study of combined spinal-epidural analgesia versus intravenous meperidine during labor: impact on cesarean delivery rate

We recently reported on the successful generation of immortalized (CEPI-17-CL4) cells from primary human corneal epithelial (P-CEPI) cells which exhibited phenotypic, immunohistochemical and metabolic characteristics akin to the P-CEPI cells. The aims of the present studies were to investigate the ligand binding and functional coupling of the histamine receptors to various biochemical and physiological systems in the P-CEPI and CEPI-17-CL4 cells and to relate these findings to the normal and/or pathophysiological role of histamine on the human ocular surface. Specific [3H]-pyrilamine binding to CEPI-17-CL4 cell homogenates comprised >93% of the total binding and represented interaction with an apparent single population of high affinity (Kd=3.76+/-0.78 nM; n=4) and saturable (Bmax = 1582+/-161 fmol g(-1) tissue) number of histamine-1 (H1) receptor binding sites on CEPI-17-CL4 cell homogenates. The H1-receptor selective antagonists, pyrilamine (Ki=3.6+/-0.84 nM, n=4) and triprolidine (Ki = 7.7+/-2.6 nM, n=3), potently displaced [3H]-pyrilamine binding, while the H2- and H3-receptor selective antagonists, ranitidine and clobenpropit, were weak inhibitors (K(i)s>13 microM). Histamine induced phosphoinositide (PI) hydrolysis 2.7-4.4 fold above basal levels and with a potency of 14.9+/-4.9 microM (n=9) and 4.7+/-0.2 microM (n=9) in P-CEPI and CEPI-17-CL4 cells, respectively. Histamine-induced PI turnover was antagonized by H1-receptor selective antagonist, triprolidine, with a potency (Ki) of 3.2+/-0.66 nM (n=10) and 3.03+/-0.8 nM (n=4) in P-CEPI and CEPI-17-CL4 cells, respectively, but weakly effected by 10 microM cimetidine and clobenpropit, H2- and H3-receptor antagonists. The PI turnover response was attenuated by pre-treatment of the cells with the selective phospholipase C inhibitor, U73122 (1-(6-((17beta-3-methoxyestra- 1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione) (IC50=4.8+/-2.4 microM, n = 3). Histamine stimulated intracellular Ca2+ ([Ca2+]i) mobilization in CEPI-17-CL4 cells with a potency of 6.3+/-1.5 microM (n=4). The histamine-induced [Ca2+]i mobilization was reduced by about 28% following pre-incubation of the cells with 4 mM EGTA. While triprolidine completely inhibited histamine-induced [Ca2+]i mobilization, it did not influence the bradykinin-induced [Ca2+]i mobilization response. Histamine (EC50s = 1.28-2.77 microM, n=3-4) concentration-dependently stimulated the release of interleukin-6 (IL-6), IL-8 and granulocyte macrophage colony-stimulating factor, but it did not significantly alter release of tumour necrosis factor-alpha, PGE2 or collagenase-1 (matrix metalloproteinase-1; MMP-1) from CEPI cells. However, IL-1 (10 ng ml(-1)), foetal bovine serum (10%) and phorbol-12-myristate-13-acetate (3 microg ml(-1)) were effective positive control secretagogues of all the cytokines, PGE2 and MMP-1, respectively, from these cells. It is concluded that the CEPI cells express H1-histamine receptors which are positively coupled to PI turnover and [Ca2+]i mobilization which may be directly or indirectly responsible for the release of various cytokines from these cells at physiologically and/or pathologically relevant concentrations.     

Introduction of a Novel Hybrid Weighted Exponential Logarithm-Maximum Throughput (HWEL-MT) Scheduler for QoS Improvement of LTE/4G Cellular Networks

The real-time broadcast of multimedia contents such as VoIP and video traffics in recent cellular networks is increasingly becoming common. In this regard, LTE networks with the objective of providing high speed data along with QoS assurance have been introduced. To perform this, schedulers in order to allocate of the resources to the traffics are used as channel-aware/QoS-aware. The most important and effective schedulers are EXP RULE and E2M RULE for this type of networks but still requires improving of QoS parameters to reach an optimal level of performance. In this paper aims to improve the packet loss rate (PLR), latency and throughput parameters especially and improve the other QoS parameters generally in the downlink LTE networks, a new scheduler called Hybrid Weighted Exponential Logarithm-Maximum Throughput (HWEL-MT) RULE method has been proposed. By performing simulations and comparisons between output results of EXP-Rule, E2M RULE and HWEL-MT RULE schedulers for VoIP, video and best effort traffics, we have totally concluded that the proposed HWEL-MT scheduler is able to improve PLR, delay, throughput, fairness and spectral efficiency more than two other examined methods. The results have been presented and compared by implementing a LTE network included 5–70 mobile users in open source LTE-Sim software.     

Multiple Workflow Scheduling Strategies with User Run Time Estimates on a Grid

In this paper, we present an experimental study of deterministic non-preemptive multiple workflow scheduling strategies on a Grid. We distinguish twenty five strategies depending on the type and amount of information they require. We analyze scheduling strategies that consist of two and four stages: labeling, adaptive allocation, prioritization, and parallel machine scheduling. We apply these strategies in the context of executing the Cybershake, Epigenomics, Genome, Inspiral, LIGO, Montage, and SIPHT workflows applications. In order to provide performance comparison, we performed a joint analysis considering three metrics. A case study is given and corresponding results indicate that well known DAG scheduling algorithms designed for single DAG and single machine settings are not well suited for Grid scheduling scenarios, where user run time estimates are available. We show that the proposed new strategies outperform other strategies in terms of approximation factor, mean critical path waiting time, and critical path slowdown. The robustness of these strategies is also discussed.