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Natural Convection of a Power-Law Nanofluid in a Square Cavity with a Vertical Fin
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作者 Amira M’hadbi Mohammed El Ganaoui +2 位作者 Haïkel Ben Hamed Amenallah Guizani Khalid Chtaibi 《Fluid Dynamics & Materials Processing》 EI 2024年第9期2091-2108,共18页
The behavior of non-Newtonian power-law nanofluids under free convection heat transfer conditions in a cooled square enclosure equipped with a heated fin is investigated numerically.In particular,the impact of nanoflu... The behavior of non-Newtonian power-law nanofluids under free convection heat transfer conditions in a cooled square enclosure equipped with a heated fin is investigated numerically.In particular,the impact of nanofluids,composed of water and Al_(2)O_(3),TiO_(2),and Cu nanoparticles,on heat transfer enhancement is examined.The aim of this research is also to analyze the influence of different parameters,including the Rayleigh number(Ra=10^(4)-10^(6)),nanoparticle volume fraction(φ=0%-20%),non-Newtonian power-law indexes(n=0.6-1.4),and fin dimensions(Ar=0.3,0.5,and 0.7).Streamlines and isotherms are used to depict flow and related heat transfer characteristics.Results indicate that thermal performance improves with increasing Rayleigh number,regardless of the nanoparticle type or nanofluid rheological behavior.This suggests that the buoyancy force has a significant impact on heat transfer,particularly near the heat source.The Nusselt number is more sensitive to variations in Cu nanoparticle volume fractions compared to Al₂O₃and TiO₂.Moreover,the average Nusselt numbers for power-law nanofluids with n<1(n>1)are greater(smaller)than for Newtonian fluids due to the decrease(increase)in viscosity with increasing(decreasing)shear rate,at the same values of Rayleigh number Ra owing to the amplification(attenuation)of the convective transfer.Notably,the most substantial enhancement is observed with Cu-water shear-thinning nanofluid,where the Nusselt number increases by 136%when changing from Newtonian to shear thinning behavior and by 154.9%when adding 16%nanoparticle volume fraction.Moreover,an even larger increase of 57%in the average Nusselt number is obtained on increasing the fin length from 0.3 to 0.7. 展开更多
关键词 Heat transfer NANOFLUID non-Newtonian fluid natural convection
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Effectiveness and safety of apixaban and rivaroxaban vs warfarin in patients with atrial fibrillation and chronic kidney disease
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作者 Sylvie Perreault Laurie-Anne Boivin Proulx +2 位作者 Aurélie Lenglet Ziad A Massy Marc Dorais 《World Journal of Nephrology》 2023年第5期132-146,共15页
BACKGROUND Randomized controlled trials(RCTs)of direct oral anticoagulants(DOACs)included a low proportion of atrial fibrillation(AF)patients with chronic kidney disease(CKD),and suggested that DOACs are safe and effe... BACKGROUND Randomized controlled trials(RCTs)of direct oral anticoagulants(DOACs)included a low proportion of atrial fibrillation(AF)patients with chronic kidney disease(CKD),and suggested that DOACs are safe and effective in patients with mild-to-moderate CKD.In a metanalysis of RCTs and observational studies,DOACs were associated with better efficacy(vs warfarin)in early CKD and had similar efficacy and safety profiles in patients with stages IV-V CKD.But few studies have provided data on the safety and effectiveness of each DOAC vs warfarin in patients with stage III CKD.The effectiveness and safety of DOACs in those patients are still subject to debate.AIM To assess and compare the effectiveness and safety of apixaban and rivaroxaban vs warfarin in this patient population.METHODS A cohort of patients with an inpatient or outpatient code for AF and stage III CKD who were newly prescribed apixaban and rivaroxaban was created using the administrative databases from the Quebec province of Canada between 2013 and 2017.The primary effectiveness outcome was a composite of ischemic stroke,systemic embolism,and death,whereas the primary safety outcome was a composite of major bleeding within a year of DOAC vs warfarin initiation.Treatment groups were compared in an under-treatment analysis using inverse probability of treatment weighting and Cox proportional hazards.RESULTS A total of 8899 included patients filled out a new oral anticoagulation therapy claim;3335 for warfarin and 5564 for DOACs.Compared with warfarin,15 mg and 20 mg rivaroxaban presented a similar effectiveness and safety composite risk.Apixaban 5.0 mg was associated with a lower effectiveness composite risk[Hazard ratio(HR)0.76;95%confidence interval(CI):0.65-0.88]and a similar safety risk(HR 0.94;95%CI:0.66-1.35).Apixaban 2.5 mg was associated with a similar effectiveness composite(HR 1.00;95%CI:0.79-1.26)and a lower safety risk(HR 0.65;95%CI:0.43-0.99.Although,apixaban 5.0 mg was associated with a better effectiveness(HR 0.76;95%CI:0.65-0.88),but a similar safety risk profile(HR 0.94;95%CI:0.66-1.35).The observed improvement in the effectiveness composite for apixaban 5.0 mg was driven by a reduction in mortality(HR 0.61;95%CI:0.43-0.88).CONCLUSION In comparison with warfarin,rivaroxaban and apixaban appear to be effective and safe in AF patients with stage III CKD. 展开更多
关键词 Atrial fibrillation Chronic kidney disease Direct oral anticoagulant EFFECTIVENESS SAFETY WARFARIN
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Procalcitonin and intestinal ischemia:A review of the literature 被引量:10
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作者 Cyril Cosse Charles Sabbagh +2 位作者 Sad Kamel Antoine Galmiche Jean-Marc Regimbeau 《World Journal of Gastroenterology》 SCIE CAS 2014年第47期17773-17778,共6页
Intestinal ischemia is common after emergency gastrointestinal or cardiovascular surgery.At present,there are no diagnostic tools for the early diagnosis of intestinal ischemia.In the last decade,procalcitonin(PCT)has... Intestinal ischemia is common after emergency gastrointestinal or cardiovascular surgery.At present,there are no diagnostic tools for the early diagnosis of intestinal ischemia.In the last decade,procalcitonin(PCT)has been suggested as a marker of this condition.Here,we review the use of PCT as a diagnostic tool for intestinal ischemia.Two reviewers independently searched the Pub Med and EMBASE databases for articles on intestinal ischemia and PCT.They then considered(1)the criteria applicable to preclinical and clinicaldata;and(2)PCT’s predictive value in the diagnosis of intestinal ischemia.Article quality was rated according to the STAndards for Reporting of Diagnostic accuracy.Between 1993 and 2014,seven studies(including two preclinical studies and five clinical studies)dealt with the use of PCT to diagnose intestinal ischemia.Procalcitonin’s sensitivity,specificity,positive predictive value and negative predictive value ranged between 72%and 100%;68%and 91%;27%and 90%and 81%and 100%,respectively.The area under the receiver operating characteristic curve ranged from 0.77 to 0.92.In view of the preclinical and clinical data,we consider that PCT can be used in daily practice as a tool for diagnosing intestinal ischemia. 展开更多
关键词 PROCALCITONIN INTESTINAL ISCHEMIA DIAGNOSIS REVIEW
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Robust Admissibility and Stabilization of Uncertain Singular Fractional-Order Linear Time-Invariant Systems 被引量:5
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作者 Saliha Marir Mohammed Chadli 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2019年第3期685-692,共8页
This paper addresses the robust admissibility problem in singular fractional-order continuous time systems. It is based on new admissibility conditions of singular fractional-order systems expressed in a set of strict... This paper addresses the robust admissibility problem in singular fractional-order continuous time systems. It is based on new admissibility conditions of singular fractional-order systems expressed in a set of strict linear matrix inequalities(LMIs). Then, a static output feedback controller is designed for the uncertain closed-loop system to be admissible. Numerical examples are given to illustrate the proposed methods. 展开更多
关键词 CONTROL FRACTIONAL-ORDER SYSTEMS linear matrix inequalities (LMIs) output feedback CONTROL robust ADMISSIBILITY SINGULAR SYSTEMS UNCERTAIN SYSTEMS
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Frey procedure for the treatment of chronic pancreatitis associated with common bile duct stricture 被引量:5
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作者 Lionel Rebibo Thierry Yzet +3 位作者 Cyril Cosse Richard Delcenserie Eric Bartoli Jean-Marc Regimbeau 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS 2013年第6期637-644,共8页
BACKGROUND:The Frey procedure(FP)is the treatment of choice for symptomatic chronic pancreatitis(CP).In cases of biliary stricture,biliary derivation can be performed by choledochoduodenostomy,Roux-en-Y choledochojeju... BACKGROUND:The Frey procedure(FP)is the treatment of choice for symptomatic chronic pancreatitis(CP).In cases of biliary stricture,biliary derivation can be performed by choledochoduodenostomy,Roux-en-Y choledochojejunostomy or,more recently,reinsertion of the common bile duct(CBD)into the resection cavity.The objective of the present study was to evaluate the outcomes associated with each of these three types of biliary derivation.METHODS:We retrospectively analyzed demographic,CPrelated,surgical and follow-up data for patients having undergone FP for CP with biliary derivation between 2004and 2012 in our university medical center.The primary efficacy endpoint was the rate of CBD stricture recurrence.The secondary endpoints were surgical parameters,postoperative complications,postoperative follow-up and the presence of risk factors for secondary CBD stricture.RESULTS:Eighty patients underwent surgery for CP during the study period.Of these,15 patients received biliary derivation with the FP.Eight of the FPs(53.3%)were combined with choledochoduodenostomy,4(26.7%)with choledochojejunostomy and 3(20.0%)with reinsertion of the CBD into the resection cavity.The mean operating time was 390minutes.Eleven complications(73.3%)were recorded,including one major complication(6.7%)that necessitated radiologicallyguided drainage of an abdominal collection.The mean(range)length of stay was 17 days(8-28)and the median(range)follow-up time was 35.2 months(7.2-95.4).Two patients presented stricture after CBD reinsertion into the resection cavity;one was treated with radiologically-guided dilatation and the other underwent revisional Roux-en-Y choledochojejunostomy.Three patients presented alkaline reflux gastritis(37.5%),one(12.5%)cholangitis and one CBD stricture after FP with choledochoduodenostomy.No risk factors for secondary CBD stricture were identified.CONCLUSIONS:As part of a biliary derivation,the FP gave good results.We did not observe any complications specifically related to surgical treatment of the biliary tract.However,CBD reinsertion into the resection cavity appeared to be associated with a higher stricture recurrence rate.In our experience,choledochojejunostomy remains the"gold standard"for the surgical treatment for CBD strictures. 展开更多
关键词 common bile duct stricture chronic pancreatitis Frey procedure PANCREATECTOMY
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Comprehensive Modulation and Classification of Faults and Analysis Their Effect in DC Side of Photovoltaic System 被引量:3
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作者 Mehrdad Davarifar Abdelhamid Rabhi Ahmed El Hajjaji 《Energy and Power Engineering》 2013年第4期230-236,共7页
The first step in automatic supervision, condition monitoring and fault detection of photovoltaic system is recognition, exploration and classification of all possible faults that maybe happen in the system. This pape... The first step in automatic supervision, condition monitoring and fault detection of photovoltaic system is recognition, exploration and classification of all possible faults that maybe happen in the system. This paper aims to perceive, classified, simulate and discus all electrical faults in DC side of photovoltaic system, regarding electrical voltage and current inspections. For that, simplified hybrid model of photovoltaic panel in MATLAB environment is used. Investigation and classification of each type of faults is down and the effects of the faults are illustrated in this paper. Flash test are applied to improved electrical model. Current-Voltage curves signature are interpreted and investigated in simulation environment. 展开更多
关键词 PHOTOVOLTAIC Systems Modeling Electrical FAULT FAULT Detection
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Multidisciplinary management of Mirizzi syndrome with cholecystobiliary fistula: the value of minimally invasive endoscopic surgery 被引量:6
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作者 Fabien Le Roux Charles Sabbagh +4 位作者 Brice Robert Thierry Yzet Laurent Dugue Jean-Paul Joly Jean-Marc Regimbeau 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS CSCD 2015年第5期543-547,共5页
Mirizzi syndrome, a rare complication of gallstones, is defined by obstruction of the main bile duct. This obstruction may worsen and thus result in cholecystobiliary fistula. Surgical management of Mirizzi syndrome i... Mirizzi syndrome, a rare complication of gallstones, is defined by obstruction of the main bile duct. This obstruction may worsen and thus result in cholecystobiliary fistula. Surgical management of Mirizzi syndrome is complicated by the presence of inflamed tissue around the hepatic pedicle, making it impossible to distinguish between the main bile duct and the gallbladder. The surgeon's first task is to perform subtotal cholecystotomy(from the fundus of the gallbladder to the neck) without trying to locate the cystic duct. In a second step, the gallstones are extracted and the main bile duct is then repaired. In most cases, a T-tube is used to drain the main bile duct, and abdominal drainage is left in place(in case a bile fistula forms). This study concluded that preoperative drainage of the main bile duct in the treatment of Mirizzi syndrome types II and III is feasible and might help to decrease the postoperative complication rate. 展开更多
关键词 jaundice Mirizzi syndrome cholecystobiliary fistula endoscopic treatment cholecystectomy T-tube drain
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Impact of homogeneous pathologic response to preoperative chemotherapy in patients with multiple colorectal liver metastases 被引量:1
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作者 Charles Sabbagh Denis Chatelain +4 位作者 Christophe Attencourt Jean-Paul Joly Bruno Chauffert Cyril Cosse Jean-Marc Regimbeau 《World Journal of Gastroenterology》 SCIE CAS 2017年第45期8027-8034,共8页
AIM To analyze the homogeneity of pathologic response to preoperative chemotherapy(PRPC) after chemotherapy in patients with multiple liver metastases(LM).METHODS From September 2011 to August 2014,patients with at le... AIM To analyze the homogeneity of pathologic response to preoperative chemotherapy(PRPC) after chemotherapy in patients with multiple liver metastases(LM).METHODS From September 2011 to August 2014,patients with at least two LM undergoing preoperative chemotherapy prior to resection were included in this retrospective,single-center study. The endpoints were PRPC homogeneity(according to both the Rubbia-Brandt and MD Anderson classifications),the impact of PRPC on the MDT decision,factors associated with homogeneous PRPC and overall survival of patients with vs. without homogeneous PRPC.RESULTS seventy-three patients with a total of 88 liver resections(including 15 two-stage procedures) were included in the study. The homogeneous PRPC rate was 55% according to the Rubbia-Brandt classification and 53% according to the MD Anderson classification. The MDT decision was modified by the PRPC in only 2.7% of patients(n = 2). CONCLUSION The PRPC was homogeneous in only one half of patients and had very little influence on the MDT decision. 展开更多
关键词 Liver metastases Pathological response HOMOGENEITY Preoperative chemotherapy Colorectal cancer
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Combined radiologic and endoscopic treatment(using the “rendezvous technique”) of a biliary fistula following left hepatectomy 被引量:1
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作者 Aurélien Gracient Lionel Rebibo +2 位作者 Richard Delcenserie Thierry Yzet Jean-Marc Regimbeau 《World Journal of Gastroenterology》 SCIE CAS 2016年第30期6955-6959,共5页
Despite the ongoing decrease in the frequency of complications after hepatectomy, biliary fistulas still occur and are associated with high morbidity and mortality rates. Here, we report on an unusual technique for ma... Despite the ongoing decrease in the frequency of complications after hepatectomy, biliary fistulas still occur and are associated with high morbidity and mortality rates. Here, we report on an unusual technique for managing biliary fistula following left hepatectomy in a patient in whom the right posterior segmental duct joined the left hepatic duct. The biliary fistula was treated with a combined radiologic and endoscopic procedure based on the "rendezvous technique". The clinical outcome was good, and reoperation was not required. 展开更多
关键词 Left HEPATECTOMY RENDEZVOUS TECHNIQUE BILIARY stent BILIARY FISTULA ANATOMIC variation
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Analysis of Urea in Petfood Matrices: Comparison of Spectro-Colorimetric, Enzymatic and Liquid Chromatography Electrospray Ionization High Resolution Mass Spectrometry Methods
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作者 Patrick Pibarot Serge Pilard 《American Journal of Analytical Chemistry》 2012年第9期613-621,共9页
Adulteration may consist in non authorized source of nitrogen addition to increase the protein content of some raw materials. Urea which is authorized for feed is a non nutritional source of nitrogen in food and pet f... Adulteration may consist in non authorized source of nitrogen addition to increase the protein content of some raw materials. Urea which is authorized for feed is a non nutritional source of nitrogen in food and pet food. Adulteration of food or pet food raw material by urea is thus monitored by manufacturer and governmental authorities with official methods which are either enzymatic (Association of Official Agricultural Chemists, AOAC) or spectro-colorimetric (European Community, EC). Each method gives results which are not comparable and spectro-colorimetric methods may result in false-positive urea detection. Liquid chromatographic (LC/UV-DAD) analysis of extracts from spectro-colorimetric method indicates that presence of free amino-acid may interfere with colorimetric detection of urea in the EC method with pet food samples. Liquid chromatography electrospray ionization high resolution mass spectrometry (LC/ESI-HRMS) has allowed to quantify low content (<0.01%) of urea in pet food water extracts for samples which resulted in significant urea detection with colorimetric method and in content below the detection threshold with enzymatic method. This study demonstrates the EC colorimetric method is not applicable to pet food and also food samples which have a complex composition with significant levels of free amino acids. On the other hand we clearly evidenced by means of the LC/ESI-HRMS results that the AOC Enzymatic method is applicable to urea quantification in pet food samples and gives reliable results. 展开更多
关键词 Pet FOOD FOOD UREA ADULTERATION ENZYMATIC Method Spectro-Colorimetry LC/UV-DAD LC/ESI-HRMS
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Conversion of Dermal Proteins of an Algerian Ovine to an Antimicrobial Agent for Skin Lesion
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作者 Tabak Messekine Djamila Meddah Boumediene Sonnet Pascal 《Journal of Environmental Science and Engineering(B)》 2016年第1期11-16,共6页
The aim of this study was the conversion of the ovine dermal proteins as a natural product that has an antimicrobial power which used for tissue repair and skin lesion. After dehairing, fleshings, deliming the animal ... The aim of this study was the conversion of the ovine dermal proteins as a natural product that has an antimicrobial power which used for tissue repair and skin lesion. After dehairing, fleshings, deliming the animal tissues (ovine) and purification, the essential oils of Lavandula officinalis, Eucalyptus globules and Eugenia caryophyllata had been supplied and fixed. The product obtained is a spongy material communicating with open voids between the fibers. With a transparent light yellow color, it has a remarkable antibacterial power and a very strong inhibitory activity on all the bacterial strains tested whose average diameter of the inhibition zones exceeds 16 mm. It is also characterized by a smell which can be aromatic, pleasant and spicy or fresh and spicy depending on the essential oil used. 展开更多
关键词 CONVERSION essential oils ovine dermal proteins natural substance medical purposes.
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Effects of Cellulose Fiber Content on Mechanical and Electrical Properties of Polyurethane Based Composites
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作者 Aomar Hadjadj Fouad Malek +3 位作者 El Miloud Maafi Lan Tighzert Omar Jbara Jean-Luc Dellis 《材料科学与工程(中英文A版)》 2013年第6期398-406,共9页
关键词 纤维素纤维 复合材料 聚氨酯基 纤维含量 机械性能 电气性能 热塑性基体 表征技术
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Is State Anhedonia Characteristic of Parkinson’s Disease?
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作者 Gwenolé Loas Pierre Krystkowiak 《Advances in Aging Research》 2015年第6期225-229,共5页
Anhedonia, the lowered ability to experience pleasure, is one of the non-motor symptoms in Parkinson’s disease. Recently, the distinction between consummatory and anticipatory anhedonia has been proposed and anhedoni... Anhedonia, the lowered ability to experience pleasure, is one of the non-motor symptoms in Parkinson’s disease. Recently, the distinction between consummatory and anticipatory anhedonia has been proposed and anhedonia, notably in PD, could constitute a stable characteristic (anhedonia-trait) or secondary symptom (anhedonia-state). Several studies, using healthy control groups, reported high state consummatory and anticipatory anhedonia in PD using the Snaith Hamilton Pleasure Scale (SHAPS), but when control groups included subjects with different illnesses no significant differences were reported. The aim of the present study was to compare PD subjects with subjects presenting a non-Parkinson motor neurological disease on the anhedonia subscale of the Beck Depression Inventory (BDI-II). This subscale rated consummatory and anticipatory anhedonia state. No significant difference was reported. This result confirmed that PD subjects were not characterized by high levels of state anhedonia when the subjects were compared to subjects with a different disease. Contrary to trait consummatory anhedonia, state anhedonia could be nonspecific to Parkinson’s disease. 展开更多
关键词 Parkinson’s Disease ANHEDONIA Consummatory Anticipatory DEPRESSION BDI-II
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Regulation of the Excitation Reactive Power of the Asynchronous Wind Turbine at Variable Speed
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作者 Taoufik Ouchbel Smail Zouggar +3 位作者 Mohamed Larbi Elhafyani Mohamed Oukili Mohammed Sedik Abdelhamid Rabhi 《Smart Grid and Renewable Energy》 2013年第3期272-280,共9页
This work focuses, initially, on modeling and simulating an isolated wind system in MATLAB/SIMULINK. And in the second part, it presents the simulation results of the wind system to start unloading and in resistive lo... This work focuses, initially, on modeling and simulating an isolated wind system in MATLAB/SIMULINK. And in the second part, it presents the simulation results of the wind system to start unloading and in resistive load, and the third part will discuss the strategy for adjusting the output voltage of the wind system to connect it to a rural operating load. The results show that in a dynamic environment where the wind speed and the load, changes abruptly, the voltage of the output is controlled at the desired value. 展开更多
关键词 RENEWABLE ENERGY WIND ENERGY Modeling Control of REACTIVE Power
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Analysis and Simulation of a Crowbar Protection for DFIG Wind Application during Power Systems Disturbances
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作者 Abdellatif Noubrik Larbi Chrifi-Alaoui +1 位作者 Pascal Bussy Abedelkrim Benchaib 《Journal of Mechanics Engineering and Automation》 2011年第4期303-312,共10页
The performance of a 1.5 MVA wind-power Doubly Fed Induction Generator (DFIG) under network fault is studied using simulator developed in MATLAB-SIMULINK. This paper investigates a new control method able to improve... The performance of a 1.5 MVA wind-power Doubly Fed Induction Generator (DFIG) under network fault is studied using simulator developed in MATLAB-SIMULINK. This paper investigates a new control method able to improve the fault-ride through capability of DFIG. In such generators the appearance of severe voltage sags at the coupling point make highlight important over currents at the rotor/stator windings, making the use of crowbar protection device necessary and inevitable in order to protect the machine as well as the rotor side power converter. The simulator consists of the DFIG analytical model, power transformer model and the detailed frequency converter model including crowbar protection device. Simulation results are carried out to show the transient behavior of the DFIG when a sudden voltage dip is introduced with and without the crowbar implementation. 展开更多
关键词 Wind energy DFIG (doubly fed induction generator) CROWBAR LVRT (low voltage ride through) power network simulation.
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Psycho-Traumatic Evaluation of Identity (PEI): Example of Depressive Disorder
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作者 Joanic Masson Amal Bernoussi +2 位作者 Yannick Gounden Charlemagne Simplice Moukouta François Erero Njiengwe 《Open Journal of Psychiatry》 2016年第4期262-272,共11页
PEI is a clinical approach which aims at assessing the links between psycho-trau- matic experience and depressive disorder. In the present study, inspired by the EMDR (Eye Movement Desensitization and Reprocessing) pr... PEI is a clinical approach which aims at assessing the links between psycho-trau- matic experience and depressive disorder. In the present study, inspired by the EMDR (Eye Movement Desensitization and Reprocessing) protocol, the PEI approach is proposed to 30 patients with depressive disorder. The aim is to determine the implication of negative cognitions and dysphoric emotions resulting from a traumatic experience on their psychopathological disorder. Our analysis shows a predominance of memories linked to a lack of affective support during childhood. The negative cognitions identified confirm a feeling of insecurity generated either by a failure of affective bond or helplessness towards the event. An alteration of self-es- teem also emerges. Likewise, the present work also shows how psychotherapeutic care should consider narrowing the focus on traumatic experiences. 展开更多
关键词 PEI EMDR Psychological Trauma Depressive Disorder PSYCHOTHERAPY
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Effect of Substitution of Cement by Mineral Powders on the Physico-mechanical Properties and Microstructure of Sand Concretes
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作者 Belkacem Belhadj Justin Houessou +1 位作者 Nicolas Montrelay Michèle Quéneudec 《Journal of Architectural Environment & Structural Engineering Research》 2022年第4期18-29,共12页
The approach that contributes to the development of eco-materials in construction is the use of mineral powders,which can improve mechani­cal properties and reduce cement consumption.This article aims to study th... The approach that contributes to the development of eco-materials in construction is the use of mineral powders,which can improve mechani­cal properties and reduce cement consumption.This article aims to study the effect of substitution by mass of cement with mineral powders on the physicomechanical properties and microstructure of sand concretes.The used mineral powders are A:the limestone,B:the natural pozzolan,C:the hydraulic lime,D:(1/3 limestone+1/3 natural pozzolan+1/3 hydraulic lime),and E:(1/2 natural pozzolan+1/2 hydraulic lime).The studied percentages are 5%,10%and 15%,in both separated and combined states.The studied properties are workability,compressive strength,the elastic­ity modulus in compression,shrinkage and microstructure analysis.The objective is to target the optimal percentage of the substitution of cement with mineral powders,which ensures the best compromise between the main properties of the studied sand concretes.The obtained results show that the optimal percentage is in favor of the substitution of cement by 10%D(1/3 limestone,1/3 natural pozzolan and 1/3 hydraulic lime).Even the 15%of mineral powder D,presented similar performances compared to the sand concrete(without mineral powders).Finally,in the context of the development of eco-materials,it should be noted that the 10%D and 15%D(1/3 limestone,1/3 natural pozzolan and 1/3 hydraulic lime)contribute to decrease the use of cement and consequently to reduce of CO2 emissions. 展开更多
关键词 Eco-materials Sand concretes CEMENTS Mineral powders Physico-mechanical properties MICROSTRUCTURE
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Occurrence of Cassava Mosaic Begomovirus New Species and Ageratum Leaf Curl Cameroon Virus on Pepper(Capsicum annuum L.)in Togo
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作者 Kodjovi Atassé Dansou-Kodjo Assion Sétu Mivedor +2 位作者 Kossikouma Djodji Adjata Jérome Duclercq Yawovi Mawuena Dieudonné Gumedzoe 《Agricultural Sciences》 2019年第5期671-682,共12页
Cassava mosaic disease caused by the whitefly-transmitted begomoviruses (family Geminiviridae) is a major threat to cassava (Manihot esculenta Crantz) production, which can be intercropped with other plants such as pe... Cassava mosaic disease caused by the whitefly-transmitted begomoviruses (family Geminiviridae) is a major threat to cassava (Manihot esculenta Crantz) production, which can be intercropped with other plants such as pepper (Capsicum annuum L.). The aim of this study is to identify cassava begomoviruses on other crops in cassava intercropping systems. Thus, foliar samples showing typical symptoms of virus diseases in cassava intercropping systems were collected from pepper and submitted to PCR analysis and direct sequencing. Three begomovirus species ACMV, EACMV and ALCCMV were identified and characterized in samples. Isolates of these species shared respectively 90% - 93%, 74% and 80% nucleotide identities with begomoviruses. These findings show that cassava begomoviruses can infect other crops and will help in understanding the epidemiology related to whitefly-transmitted begomoviruses in cassava intercropping systems. 展开更多
关键词 ACMV ALCCMV BEGOMOVIRUS EACMV PEPPER Sequencing
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Genetic Diversity of Tomato(Solanum lycopersicum L.)Begomovirus in Togo
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作者 Assion Setu Mivedor Justin Simon Pita +2 位作者 Kossikouma Djodji Adjata Jerome Duclercq Yawovi Mawuena Dieudonne Gumedzoe 《Agricultural Sciences》 2017年第12期1402-1414,共13页
Geminiviruses, in particular the members of the genus Begomovirus , are considered to be a major phytosanitary problem for tomato crops production in the world. They are responsible for yield losses of up to 20% to 10... Geminiviruses, in particular the members of the genus Begomovirus , are considered to be a major phytosanitary problem for tomato crops production in the world. They are responsible for yield losses of up to 20% to 100%. Regrettably, Togo is not spared from this situation. This work aims to show the genetic diversity of the begomoviruses affecting tomato crops production in Togo and their relationship with other begomoviruses. To achieve these objectives, 307 samples of tomato leaves and wild plant species with typical virus symptoms were collected in the Maritime, Plateaus, Central, Kara and Savannah regions and submitted to PCR analysis. The results revealed the presence of begomovirus in 25.40% of the analyzed samples. The PCR products obtained were submitted to direct sequencing. Phylogenetic analysis of sequences of DNA-A different regions of begomovirus identified in this work with that of other begomoviruses showed a nucleotide identity of 96% respectively for Tomato leaf curl Togo virus-Fontem, Tomato Leaf Curl Togo Virus , Ageratum leaf curl Cameroon Alphasatellite;98% respectively to Tomato leaf curl Nigeria virus , Ageratum leaf curl Cameroon virus , Tomato leaf curl Cameroon virus-Fontem, Ageratum leaf curl Cameroon virus and 99% respectively to Tomato leaf curl Kumasi virus , Pepper yellow vein Mali virus Bazegahot and Pepper yellow vein Mali virus-Ouaga. These results suggest a high degree of genetic diversity of tomato begomoviruses identified in Togo. 展开更多
关键词 BEGOMOVIRUSES Direct Sequencing Phylogenetic Relationships TOMATO Wild Plants
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求解二维矩形Packing面积最小化问题的动态归约算法 被引量:2
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作者 何琨 姬朋立 李初民 《软件学报》 EI CSCD 北大核心 2013年第9期2078-2088,共11页
二维矩形Packing面积最小化问题(rectangle packing area minimization problem,简称RPAMP)是具有NP难度的高复杂度的布局优化问题,也是大规模集成电路设计中floorplanning问题的一个核心问题.通过动态构造矩形框的宽和高,将求解一个RP... 二维矩形Packing面积最小化问题(rectangle packing area minimization problem,简称RPAMP)是具有NP难度的高复杂度的布局优化问题,也是大规模集成电路设计中floorplanning问题的一个核心问题.通过动态构造矩形框的宽和高,将求解一个RPAMP转化为求解一组二维矩形Packing判定问题(rectangle packing decision problem,简称RPDP).在求解RPDP的最大适配度算法的基础上,进一步考虑了当前动作对全局紧凑性的影响,评估了当前动作对局部空间的损害程度,设计了求解RPDP的最小损害度算法.然后,结合矩形框宽、高的动态构造方法,设计得到求解RPAMP的最终算法.对15个相关的RPAMP算例(包括著名的MCNC算例和GSRC算例)进行了测试.更新了其中9个算例的最好记录,另有2个与当前的最好记录持平.得到了98.50%的平均填充率,将国内外文献中已见报道的最高平均填充率提高了0.85%. 展开更多
关键词 NP难度 布局优化 布图规划 面积最小化 启发式
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