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Effect of Upward Internal Flow on Dynamics of Riser Model Subject to Shear Current

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China Ocean Engineering 2012年第1期26卷 95-108页

作者：陈正寿 KIM Wu-joan 熊丛博 School of Naval Architecture and Civil Engineering Zhejiang Ocean University Department of Ocean Engineering Mokpo National University The First Institute of Oceanography State Oceanic Administration

Numerical study about vortex-induced vibration （V/V） related to a flexible riser model in consideration of internal flow progressing inside has been performed. The main objective of this work is to investigate the coupled fluid-structure interaction （FSI） taking place between tensioned riser model, external shear current and upward-progressing internal flow （from ocean bottom to surface）. A CAE technology behind the current research which combines structural software with the CFD technology has been proposed. According to the result from dynamic analysis, it has been found that the existence of upward-progressing internal flow does play an important role in determining the vibration mode （/dominant frequency）, vibration intensity and the magnitude of instantaneous vibration amplitude, when the velocity ratio of internal flow against external current is relatively high. As a rule, the larger the velocity of intemal flow is, the more it contributes to the dynamic vibration response of the flexible riser model. In addition, multi-modal vibration phenomenon has been widely observed, for asymmetric curvature along the riser span emerges in the case of external shear current being imposed.

关键词： internal flow upward-progressing fluid-structure interaction velocity ratio

Abnormal endogenous pain modulation and somatic and visceral hypersensitivity in female patients with irritable bowel syndrome

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World Journal of Gastroenterology 2007年第27期13卷 3699-3704页

作者： Clive H Wilder-Smith joan Robert-Yap Brain-Gut Research Group Gastroenterology Group Practice Berne Switzerland Supported by the Brain-Gut Research Group Berne Switzerland

AIM： To investigate the role of endogenous pain modulatory mechanisms in the central sensitization implicated by the visceral hypersensitivity demonstrated in patients with irritable bowel syndrome （IBS）. Dysfunction of modulatory mechanisms would be expected to also result in changes of somatic sensory function. METHODS： Endogenous pain modulatory mechanisms were assessed using heterotopic stimulation and somatic and visceral sensory testing in IBS. Pain intensities （visual analogue scale, VAS 0-100） during suprathreshold rectal distension with a barostat, cold pressor stimulation of the foot and during both stimuli simultaneously （heterotopic stimulation） were recorded in 40 female patients with IBS and 20 female healthy controls. RESULTS： Rectal hypersensitivity （defined by 95% Cl of controls） was seen in 21 （53%）, somatic hypersensitivity in 22 （55%） and both rectal and somatic hypersensitivity in 14 of these IBS patients. Heterotopic stimulation decreased rectal pain intensity by 6 （-11 to -1） in controls, but increased rectal pain by 2 （-3 to ＋6） in all IBS patients （P 〈 0.05） and by 8 （-2 to ＋19） in IBS patients with somatic and visceral hypersensitivity （P 〈 0.02）. CONCLUSION： A majority of IBS patients had abnormal endogenous pain modulation and somatic hypersensitivity as evidence of central sensitization.

关键词： Diffuse noxious inhibitory controls Endogenous pain modulation Hypersensitivity Irritable Bowel Syndrome Quantitative sensory testing Visceral pain Sensitization

An Adaptive Power Allocation Scheme for Performance Improvement of Cooperative SWIPT NOMA Wireless Networks

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Computers, Materials & Continua 2020年第5期63卷 1043-1064页

作者： Manimekalai Thirunavukkarasu Romera joan Sparjan Laxmikandan Thangavelu College of Engineering Guindy Anna UniversityChennai600025India

Future wireless networks demand high spectral efficiency,energy efficiency and *** non-orthogonal multiple access(NOMA)with simultaneous wireless information and power transfer(SWIPT)is considered as one of the novel techniques to meet this *** this work,an adaptive power allocation scheme called SWIPT based adaptive power allocation(SWIPT-APA-NOMA)is proposed for a power domain NOMA *** proposed scheme considers the receiver sensitivity of the end users while calculating the power allocation coefficients in order to prevent wastage of power allocated to user in outage and by offering priority to any one of the users to use maximum harvested power.A detailed analysis on the bit error rate(BER)performance of the proposed scheme is done and closed form expression is *** have been carried out with various parameters that influence the receiver sensitivity and the results show that the network achieves better outage and BER performance using the proposed *** is found that the proposed scheme leads to a ten-fold decrease in transmit power for the same error performance of a fixed power allocation ***,it offers 96.06%improvement in the capacity for a cumulative noise figure and fading margin of 10 dB.

关键词： NOMA SWIPT cooperative relaying adaptive power allocation

Molecular rotors as a class of generally highly active ion transporters

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Science China Chemistry 2021年第12期64卷 2154-2160页

作者： Jie Shen joan Jia Ying Han Ruijuan Ye Huaqiang Zeng Frontier Research Center for Multidisciplinary Sciences School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an710072China Temasek Polytechnic 21 Tampines Avenue 1Singapore529757Singapore

We describe here a class of unconventional ion transporters,molecular rotors that transport ions through a rotating function rather than via traditional carrier or channel *** macroscopic rotors,these molecular rotors consist of three modularly tunable components,i.e.,a membrane-anchoring stator,a crown ether-containing rotator for ion binding and transport,and a triple bond-based axle that allows the rotator to freely rotate around the stator in the lipid *** bilayer experiments reveal the generally high ability of all molecular rotors in promoting the highly efficient transmembrane K^(+)flux(EC50 values=0.49-1.37 mol%relative to lipid).While molecular rotors differing only in the ion-binding unit exhibit similar ion transport activities,those differing in the rotator’s length display activity differences by up to 174%.

关键词： supramolecular chemistry molecular machines artificial membrane transporters molecular rotors K+transporters

Probabilistic Delay Fault Model for DVFS Circuits

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Tsinghua Science and Technology 2011年第4期16卷 399-407页

作者：雷庭孙义和 joan Figueras Institute of Microelectronics Tsinghua University Department of Electronic Engineering Universitat Politècnica de Catalunya

Decreasing the power supply voltage in dynamic voltage frequency scaling to save power con- sumption may introduce extra delays in CMOS circuits, which may cause errors. This paper presents the probabilistic delay fault model （PDFM）, which describes the probability of an error occurring as a function of the power supply voltage and the clock period in synchronous CMOS circuits. In a wide range of applica- tions （graphic, video, digital filtering, etc.）, errors occurring with low probability and not remaining for a long time are acceptable. For combinational circuits which have long critical paths with low probability of excita- tion, a performance increase is achieved with a certain rate of errors determined by the PDFM compared with the traditional design which considers the worst case. The PDFM applied to array multipliers and ripple carry adders shows the agreement of the predicted probabilities with simulated delay histograms to support the practicality of using the PDFM to select power supply voltage and clock period in dynamic voltage fre- quency scaling circuits with tolerable error rates.

关键词： dynamic voltage frequency scaling delay fault timing violation probability

Esophagogastric junction distensibility assessed using the functional lumen imaging probe

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World Journal of Gastroenterology 2017年第7期23卷 1289-1297页

作者： joan W Chen Joel H Rubenstein Department of Gastro-enterology and Hepatology University of Michigan Health SystemsAnn ArborMI 48109United States

To assess reference values in the literature for esophageal distensibility and cross-sectional area in healthy and diseased subjects measured by the functional lumen imaging probe (FLIP).METHODSSystematic search and review of articles in Medline and Embase pertaining to the use of FLIP in the esophagus was conducted in accordance with the PRISMA guidelines. Cross-sectional area and distensibility at the esophagogastric junction (EGJ) were abstracted for normal subjects, achalasia, and gastroesophageal reflux disease (GERD) patients, stratified by balloon length and volume of *** achalasia studies (n = 154), 3 GERD (n = 52), and 5 studies including healthy controls (n = 98) were included in the systematic review. Normative data varied widely amongst studies of healthy volunteers. In contrast, studies in achalasia patients uniformly demonstrated low point estimates in distensibility ≤ 1.6 mm2/mmHg prior to treatment that increased to ≥ 3.4 mm2/mmHg following treatment at 40mL bag volume. In GERD patients, distensibility fell to the range of untreated achalasia (≤ 2.85 mm2/mmHg) following *** may be a useful tool in assessment of treatment efficacy in achalasia. The drastic drop in EGJ distensibility after fundoplication suggests that FLIP measurements need to be interpreted in the context of esophageal body motility and highlights the importance of pre-operative screening for dysmotility. Future studies using standardized FLIP protocol and balloon size are needed.

关键词： Impedance planimetry Gastroesophageal reflux disease Esophageal distensibility Achalasia

Computational Study of Interstitial Hydrogen Atoms in Nano-Diamond Grains Embedded in an Amorphous Carbon Shell

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Communications in Computational Physics 2011年第4期9卷 843-858页

作者： Amihai Silverman Alon Hoffman joan Adler Taub Computer Center Technion-IITHaifa 32000Israel Schulich Faculty of Chemistry Technion-IITHaifa 32000Israel Department of Physics Technion-IITHaifa 32000Israel

The properties of hydrogen atoms in a nano-diamond grain surrounded by an amorphous carbon shell are studied with Tight Binding computer *** samples model nano-diamond grains,of a few nanometers in size,that nucleate within an amorphous carbon matrix,as observed in deposition from a hydrocarbon rich *** calculations show that the average hydrogen interstitial formation energy in the amorphous region is lower than in the nano-diamond core,therefore hydrogen interstitial sites in the in the amorphous region are more stable than in the nano-diamond *** formation energy difference is the driving force for the diffusion of hydrogen atoms from nano-diamond grains into amorphous carbon *** energy well was observed on the amorphous side of the nano-diamond amorphous carbon interface:hydrogen atoms are expected to be trapped *** scenario agrees with experimental results which show that hydrogen retention of diamond films increases with decreasing grain size,and suggest that hydrogen is bonded and trapped in nano-diamond grain boundaries and on internal grain surfaces.

关键词： Nano-diamond amorphous-carbon DOS NEXAFS molecular-dynamics tightbinding

Gene expression changes after hypoxic preconditioning in rat hepatocytes

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Hepatobiliary & Pancreatic Diseases International 2006年第3期5卷 416-421页

作者： joan Rosello-Catafau Department of Experimental Pathology Instituto de Investigaciones Biomedicas de Barcelona CSICSpain

BACKGROUND: Hypoxic preconditioning can protect hepatocytes against hypoxic injury, but its mechanism has not been elucidated. The aim of this study was to profile gene expression patterns involved in hypoxic preconditioning and probable mechanism at the level of gene expression. METHODS: Hepatocytes were divided into 2 groups: control group and hypoxic preconditioning group. Biotinlabeled cRNA from the control group and the hypoxic preconditioning group was hybridized by oligonucleotide microarray. Genes that were significantly associated with hypoxic preconditioning were filtered, and validated at the level of transcript expression. RESULTS: Forty-three genes with significantly altered expression patterns were discovered and most of them had not been previously reported. Among these genes,genes encoding superoxide dismutase 2 (SOD2)and interleukin 10 (IL-10) in the hypoxic preconditioning group were confirmed to be up-regulated with real-time quantitative PCR. CONCLUSIONS: Many cytokines are involved in hypoxic preconditioning and protect hepatocytes from hypoxiareoxygenation injury, and the increase of oxygen freeradical scavengers and anti-inflammatory factors may play a key role in this phenomenon. Diverse signal pathways are probably involved.

关键词： hepatocyte hypoxic preconditioning oligonucleotide microarray superoxide dismutase 2 interleukin 10

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