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Finite Element Analysis of Porous Titanium Alloy Hip Stem to Evaluate the Biomechanical Performance During Walking and Stair Climbing

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Journal of Bionic Engineering 2019年第6期16卷 1103-1115页

作者： sami Emad Alkhatib Hassan Mehboob Faris Tarlochan School of Mechanical and Chemical Engineering M050The University of Western Australia35 Stirling HighwayCrawleyPerthWA6009Australia Department of Engineering Management College of EngineeringPrince Sultan UniversityRiyadhKingdom of Saudi Arabia Department of Mechanical and Industrial Engineering College of EngineeringQatar UniversityDohaQatar

Despite the success of cementless hip stem,stress shielding still presents a serious problem leading to bone *** incorporating porous cellular structures represent a promising ***,this study validates the finite element models of titanium(Ti)alloy(Ti-6Al-4V)porous stem and effective porous *** effective porous stems with strut thicknesses 0.33 mm-1.25 mm(18%-90%porosity)under different loading conditions were *** results of finite element models revealed that changing the load type and porosity affect stress *** loads yield the maximum stress levels while walking loads result in the lowest stresses in the ***,the point load results in the maximum stress shielding and micromotions(-19% to 18%,40μm to 703μm),as compared to walking(-17.5% to 3%,35μm to 242μm)and climbing loads(-7% to 1.6%,30μm to 221 μm).Finally,effective porous stems of strut thickness 0.87 mm exhibit the lowest stress shielding signals(<5%)under all loading conditions.

关键词： porous cellular microstructures porous hip stems physiological loads finite element analysis stress shielding

Comparison of Parallel Kinematic Machines with Three Translational Degrees of Freedom and Linear Actuation

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Chinese Journal of Mechanical Engineering 2015年第4期28卷 841-850页

作者： PRAUSE Isabel CHARAF EDDINE sami CORVES Burkhard Department of Mechanism Theory and Dynamics of Machines RWTH Aachen University

The development of new robot structures, in particular of parallel kinematic machines（PKM）, is widely systematized by different structure synthesis methods. Recent research increasingly focuses on PKM with less than six degrees of freedom（DOF）. However, an overall comparison and evaluation of these structures is missing. In order to compare symmetrical PKM with three translational DOF, different evaluation criteria are used. Workspace, maximum actuation forces and velocities, power, actuator stiffness, accuracy and transmission behavior are taken into account to investigate strengths and weaknesses of the PKMs. A selection scheme based on possible configurations of translational PKM including different frame configurations is presented. Moreover, an optimization method based on a genetic algorithm is described to determine the geometric parameters of the selected PKM for an exemplary load case and a prescribed workspace. The values of the mentioned criteria are determined for all considered PKM with respect to certain boundary conditions. The distribution and spreading of these values within the prescribed workspace is presented by using box plots for each criterion. Thereby, the performance characteristics of the different structures can be compared directly. The results show that there is no ＂best＂ PKM. Further inquiries such as dynamic or stiffness analysis are necessary to extend the comparison and to finally select a PKM.

关键词： parallel kinematic machines comparison benchmark selection scheme

Spinal dural arteriovenous fistula:a comprehensive review of the history,classification systems,management,and prognosis

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Chinese Neurosurgical Journal 2024年第1期10卷 48-56页

作者： Ali Alkhaibary Ahoud Alharbi Nada Alnefaie Hajar Alammar Alshaymaa M.Arishy Noor Alghanim Yazeed M.Aldhfyan Arwa Albaiahy Yahya H.Khormi Wael Alshaya Saad AlQahatani Ahmed Aloraidi Ahmed Alkhani sami Khairy College of Medicine King Saud Bin Abdulaziz University for Health SciencesRiyadhSaudi Arabia King Abdullah International Medical Research Center RiyadhSaudi Arabia Division of Neurosurgery Department of SurgeryKing Abdulaziz Medical CityMinistry of National Guard-Health AffairsRiyadhSaudi Arabia Department of Neurosurgery National Neurosciences InstituteKing Fahad Medical CityRiyadhSaudi Arabia College of Medicine Jazan UniversityJazanSaudi Arabia Department of Neurosurgery King Faisal Specialist Hospital and Research CenterRiyadhSaudi Arabia Department of Surgery Faculty of MedicineJazan UniversityJazanSaudi Arabia

Spinal dural arteriovenous fistulas account for the majority of spinal vascular *** are typically located in the thoracolumbar region and are diagnosed in the middle-aged and elderly *** spinal dural arteriovenous fistulas have been postulated to be acquired,their exact development remains ***,the arteriovenous shunt is situated close to the spinal nerve root,inside the dura mater,where the blood from the radiculomeningeal artery and radicular vein *** history,there have been multiple classification systems of spinal arteriovenous shunts since *** were mainly based on the evolution of diagnostic studies as well as the treatment of these *** classification systems have undergone significant changes over the *** intracranial dural arteriovenous fistula,spinal dural arteriovenous fistula is progressive in *** neurological manifestations,due to venous congestion,tend to be insidious as well as *** include sensory deficits,such as paresthesia,bilateral and/or unilateral radicular pain affecting the lower limbs,and gait *** dural arteriovenous fistulas can be suspected on magnetic resonance imaging/magnetic resonance angiography and confirmed by digital subtraction angiography(DSA).The management includes surgery,endovascular therapy,and in selected cases,*** treatment goal of spinal dural arteriovenous fistula is to halt the progression of the *** prognosis depends on both the duration of symptoms as well as the clinical condition prior to *** present article comprehensively reviews the pathophysiology,changes in classification systems,natural history,clinical manifestations,radiological features,management,and prognosis.

关键词： Connection Endovascular Myelopathy Vascular

Primary malignant vascular tumors of the liver in children:Angiosarcoma and epithelioid hemangioendothelioma

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World Journal of Gastrointestinal Oncology 2021年第4期13卷 223-230页

作者： sami Bannoura Juan Putra Department of Paediatric Laboratory Medicine Hospital for Sick Children555 University AveToronto M5G 1X8OntarioCanada

Primary malignant vascular neoplasms of the liver,angiosarcoma and epithelioid hemangioendothelioma,are extremely rare entities in the pediatric *** Society for the Study of Vascular Anomalies classification system is recommended for the pathologic diagnosis of hepatic vascular lesions in this age *** this article,we highlight the clinicopathologic characteristics of hepatic angiosarcoma and epithelioid hemangioendothelioma in the pediatric *** angiosarcoma in children shows a slight female predominance with an average age of 40 mo at *** distinct histologic features include whorls of atypical spindled cells and eosinophilic globules,in addition to the general findings of *** diagnosis of pediatric hepatic angiosarcoma is not always straightforward,and the diagnostic challenges are discussed in the *** epithelioid hemangioendothelioma also demonstrates a female predominance,but is more commonly identified in adolescents(median age at diagnosis:12 years).Histologically,the lesion is characterized by epithelioid cells and occasional intracytoplasmic lumina with a background of fibromyxoid *** WWTR1-CAMTA1 and YAP1-TFE3 fusions have been associated with epithelioid hemangioendothelioma,there are currently no known signature genetic alterations seen in pediatric hepatic *** in molecular pathology,particularly for pediatric hepatic angiosarcoma,is necessary for a better understanding of the disease biology,diagnosis,and development of targeted therapies.

关键词： Pediatric Hepatic angiosarcoma Epithelioid hemangioendothelioma Infantile hemangioma Liver tumor Molecular genetics

Role of endoscopic retrograde cholangiopancreatography in the management of hepatic hydatid disease

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World Journal of Gastroenterology 2014年第41期20卷 15253-15261页

作者： Kemal Dolay sami Akbulut Department of Surgery Medipol University Faculty of Medicine Department of Surgery and Liver Transplant Institute Inonu University Faculty of MedicineTurgut Ozal Medical Center

Most cases of hepatic hydatid disease exhibit uncomplicated clinical course and ***,the diagnosis and management of complicated hepatic hydatid disease is a special *** of the most common and serious complications of hepatic hydatid disease is the rupture of the cyst into intrahepatic bile *** clinical appearance of intrabiliary rupture can range from asymptomatic to jaundice,cholecystitis,cholangitis,liver abscess,pancreatitis and *** treatments for major ruptures can result in high morbidity and mortality ***,ruptures that cannot be diagnosed preoperatively can induce complications such as biliary fistulae,biloma,cavitary infection and obstructive *** the past,these complications were diagnosed and treated by surgical ***,complications in both the pre- and postoperative periods are diagnosed and treated by non-invasive or minimally invasive *** clinical practice,endoscopic retrograde cholangiopancreatography(ERCP) is indicated for patients with preoperative frank intrabiliary rupture in which hydatid elements are clearly seen in the bile ducts,or for biliary adverse events after surgery,including persistent biliary fistulae and ***,controversy concerning routine preoperative ERCP and prophylactic endoscopic sphincterotomy in patients suspected of having minor cystobiliary communications still *** this article,the role of ERCP in the diagnosis and management of hepatic hydatid disease during the pre- and postoperative periods is reviewed.

关键词： Hydatid cyst Complications Intrabiliary rupture Endoscopic retrograde cholangiopancreatography

Computational fluid dynamic(CFD)modelling of transient flow in the intermittent gas lift

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Petroleum Research 2020年第2期5卷 144-153页

作者： Nagham Amer sami Zoltan Turzo Petroleum and Natural Gas Institute Faculty of Earth Science and EngineeringUniversity of Miskolc3515MiskolcHungary Department of Petroleum Engineering College of EngineeringUniversity of BaghdadAljadrea10071BaghdadIraq

A computational fluid dynamics model(CFD)is developed for intermittent gas lift *** simulation is conducted for a test section of 18 m vertical tube with 0.076 m in diameter using air as injection gas and oil as a formation *** results obtained from the CFD model are validated with the experiment results from the *** current study shows that computational modeling is a proven simulation program for predicting intermittent gas lift characteristics and the transient flow parameters that are changing with time and position in the coordinate *** model can predict the slug velocity behavior for different injection *** slug velocity profile shows three regions;the first region is the rapid acceleration at the initial time of injection,the second region shows the nearly constant velocity until the slug reaches the surface and the third region is again the rapid acceleration when the liquid starts to ***,the results obtained from this model show that as the gas injection pressure increases,the liquid slug velocity increase,and the region of the constant velocity *** effect of the injection time on the liquid production rate has been studied for two different gas injection pressures of 40 psig and 50 *** developed model shows that more than 50%of the liquid production is coming from after flow period.

关键词： Intermittent gas lift Slug velocity Transient flow CFD Artificial lift

On the effectiveness of dry drainage in soil salinity control

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Science China(Technological Sciences) 2009年第11期52卷 3328-3334页

作者： VINCENT Bernard BOUARFA sami VIDAL Alain Cemagref BP 44 92163 Antony Cedex France Cemagref 361 rue Jean-Franois Breton BP 5095 34196 Montpellier Cedex 5 France

Dry drainage is thought to be a potential approach to control soil salinity. This study took the Hetao Irrigation District as an example and evaluated the effectiveness of dry drainage by using remote sensing, a conceptual model and a field experiment. Archived remote sensing images from 1973―2006 were used to delineate the temporal and spatial change of soil salinity. The conceptual water and salt balance model was used to evaluate the role of dry drainage in removing excess salt from the irrigated land. The field experiment was performed to get field validation and give more accurate estimation. The results show that dry drainage did contribute to remove excess salt from the irrigated land and succeed in controlling soil salinity in the Hetao Irrigation District. It can be taken as an alternative approach in (semi-)arid area where artificial drainage is not applicable.

关键词： soil salinity dry drainage remote sensing conceptual model field experiment

Structural Characterization, Vibrational Studies and Electrical Properties of 2-Amino-3-benzyloxy Pyridinium Perchlorate

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Chemical Research in Chinese Universities 2015年第5期31卷 693-698页

作者： sami Soukrata MOHAMED Belhouchet TAHAR Mhiri Laboratory of Solid State Faculty of Sciences University of Sfax 3000 Sfax Tunisia

A title organic-inorganic hybrid material 2-amino-3-benzyloxy pyridinium perchlorate was synthesized by slow evaporation at room temperature using 2-amino-3-benzyloxypyridine as the structure-directing agent. The structure of the title compound was determined by means of single-crystal X-ray diffraction at 293 K. The results show that this compound crystallizes in the centrosymetric monoclinic system with a space group of P2 1/n and lattice parameters of a=0.7025（5） nm, b=1.2635（5） nm, c=1.5766（5） nm, Z=4 and V=1.3905（2） nm^3. The crystal structure has been determined and refined to R1=0.0367 and wR2=0.1022 using 2326 independent reflections and can be described as a succession of organic and inorganic layers parallel to the bc plane. In this arrangement, hydrogen bonds and van der Waals interactions between different species play an important role in the two-dimensional（2D） network cohesion. This compound was also characterized by means of infrared spectroscopy, Raman spectroscopy and thermogravimetric analysis-differential thermal analysis（TG-DTA）. Moreover, protonic conduction of this compound determined by an impedance analyzer has been studied in the temperature range of 303--373 K.

关键词： Organic-inorganic hybrid Chemical synthesis Infrared and Raman spectroscopy Thermal analysis Electrical property

Computational fluid dynamic(CFD)simulation of pilot operated intermittent gas lift valve

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Petroleum Research 2020年第3期5卷 254-264页

作者： Nagham Amer sami Zoltan Turzo Petroleum and Natural Gas Institute Faculty of Earth Science and EngineeringUniversity of Miskolc3515MiskolcHungary

To design an efficient intermittent gas-lift installation,reliable information is needed in the performance of all process components,from the outer boundary of the reservoir to the surface *** gas lift valve is the one critical component that affects the design of the whole *** intermittent producing system,the pilot gas-lift valve is extremely used to control the point of compressed gas entry into the production tubing and acts as a pressure regulator.A novel approach using computational fluid dynamics simulation was performed in this study to develop a dynamic model for the gas passage performance of a 1-in.,Nitrogen-charged,pilot gas-lift *** performance curves were obtained by using Methane as an injection gas with flow rates reaching up to 4.5 MMscf/*** study investigates the effect of internal pressure,velocity and temperature distribution within the pilot valve that cannot be predicted in the experiments and mathematical models during the flow-performance studies.A general equation of the nonconstant discharge coefficient has been developed for 1-inch pilot valve to be used for further calculation in the industry without using CFD *** developed model significantly reduces the complexity of the data required to calculate the discharge coefficient.

关键词： Gas lift Intermittent Pilot valve CFD Discharge coefficient