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Experimental investigation of typical surface treatment effect on velocity fluctuations in turbulent flow around an airfoil

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Chinese Journal of Aeronautics 2023年第10期36卷 112-123页

作者： Babak ELHAMI Mojtaba.dehghan manshadi Ali Akbar dehghan Faculty of Mechanical Engineering Malek Ashtar University of TechnologyIsfahan 177415875Iran Mechanical Engineering Faculty Yazd UniversityYazd ***Iran

Noise reduction of different airfoils is important because these sections are used in wind turbines,propellers,and aircraft *** methods are used for passive noise reduction of *** of these methods is the use of surface *** this research,the effect of the typical surface treatment element(finlets)on the vortex structure at different frequencies in the turbulent flow created on the NACA2412 section is *** this purpose,one-dimensional hot wire probe is *** used surface treatment in this research has a special geometry and the distance between two consecutive finlets is 6 mm(S=6 mm).This study shows that this surface treatment element can be used for noise reduction in high *** result of this research is the suggestion of the most suitable position to install this special surface treatment element to reduce vortex energy in all frequency *** installation location is determined based on a dimensionless parameter(X_(aft)/h).

关键词： Finlet spacing Passive noise reduction Sound Pressure Level(SPL) Surface treatment(finlets) Velocity power spectral density

Numerical evaluation of passive control of shock wave/boundary layer interaction on NACA0012 airfoil using jagged wall

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Acta Mechanica Sinica 2016年第5期32卷 792-804页

作者： Mojtaba.dehghan manshadi Ramin Rabani Mechanical and Aerospace Engineering Department Malek-Ashtar University of TechnologyEsfahan Iran Department of Mechanical Engineering Yazd University

Shock formation due to flow compressibility and its interaction with boundary layers has adverse effects on aerodynamic characteristics, such as drag increase and flow separation. The objective of this paper is to appraise the practicability of weakening shock waves and, hence, reducing the wave drag in transonic flight regime using a two-dimensional jagged wall and thereby to gain an appropriate jagged wall shape for future empirical study. Different shapes of the jagged wall, including rectangular, circular, and triangular shapes, were employed. The numerical method was validated by experimental and numerical studies involving transonic flow over the NACA0012 airfoil, and the results presented here closely match previous experimental and numerical results. The impact of parameters, including shape and the length-to-spacing ratio of a jagged wall, was studied on aerodynamic forces and flow field. The results revealed that applying a jagged wall method on the upper surface of an airfoil changes the shock structure significantly and disintegrates it, which in turn leads to a decrease in wave drag. It was also found that the maximum drag coefficient decrease of around 17 % occurs with a triangular shape, while the maximum increase in aerodynamic efficiency（lift-to-drag ratio）of around 10 % happens with a rectangular shape at an angle of attack of 2.26？.

关键词： Jagged wall Passive flow control Shock wave/boundary layer interaction Aerodynamic efficiency

Effects of Bulbous Bow on Cross-Flow Vortex Structures Around a Streamlined Submersible Body at Intermediate Pitch Maneuver： A Numerical Investigation

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Journal of Marine Science and Application 2016年第1期15卷 8-15页

作者： Saeed Abedi Ali Akbar dehghan Ali Saeidinezhad Mojtaba.dehghan manshadi Department of Mechanical Engineering Yazd University Yazd 89195-741 Iran Department of Mechanical and Aerospace Engineering Malek Ashtar University of Technology Esfahan 83145-115 Iran

在在一个中间的入射角的优化身体附近的一块流动地被跨流动的分离和旋涡的流动地统治。分开的流动在身体的 leeside 上导致一双旋涡；因此，精确地决定这对并且估计它的尺寸和地点是必要的。这研究基于 RANS 方程利用基于元素的有限体... 详细信息

在在一个中间的入射角的优化身体附近的一块流动地被跨流动的分离和旋涡的流动地统治。分开的流动在身体的 leeside 上导致一双旋涡；因此，精确地决定这对并且估计它的尺寸和地点是必要的。这研究基于 RANS 方程利用基于元素的有限体积方法在 SUBOFF 赤裸的 submarined 壳附近计算 3D axisymmetric 流动。跨流动的旋涡结构然后数字地与 SUBOFF 和 DRDC STR 弓为一艘潜水艇被模仿并且比较。计算结果迫使并且砍旋涡结构的壳表面和力量和地点上的压力分发在 20 的一个中间的发生角度被介绍？？

关键词：数值研究涡结构交叉流球鼻艏俯仰潜体剪切应力分布风洞实验

Experimental study of flow field distribution over a generic cranked double delta wing

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Chinese Journal of Aeronautics 2016年第5期29卷 1196-1204页

作者： Mojtaba.dehghan manshadi Mehdi Eilbeigi Mohammad Kazem Sobhani Mehrdad Bazaz Zadeh Mohammad Ali Vaziry Department of Mechanical and Aerospace Engineering Malek Ashtar University of Technology

The flow fields over a generic cranked double delta wing were investigated. Pressure and velocity distributions were obtained using a Pitot tube and a hot wire anemometer. Two different leading edge shapes, namely ＂sharp＂ and ＂round＂, were applied to the wing. The wing had two sweep angles of 55° and 30°. The experiments were conducted in a closed circuit wind tunnel at velocity 20 m/s and angles of attack of 5°- 20° with the step of 5°. The Reynolds number of the model was about 2 - 105 according to the root chord. A dual vortex structure was formed above the wing surface. A pressure drop occurred at the vortex core and the root mean square of the measured velocity increased at the core of the vortices, reflecting the instability of the flow in that region. The magnitude of power spectral density increased strongly in spanwise direction and had the maximum value at the vortex core. By increasing the angle of attack, the pressure drop increased and the vortices became wider; the vortices moved inboard along the wing, and away from the surface; the flow separation was initiated from the outer portion of the wing and developed to its inner part. The vortices of the wing of the sharp leading edge were stronger than those of the round one.

关键词： Cranked double delta wing Flow field Hot wire Leading edge shape Vortical flow

Experimental Investigation of the Effect of Bow Profiles on Resistance of an Underwater Vehicle in Free Surface Motion

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Journal of Marine Science and Application 2015年第1期14卷 53-60页

作者： Mehran Javadi Mojtaba.dehghan manshadi Saeid Kheradmand Mohammad Moonesun Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 Iran Department of Mechanical and Aerospace Engineering Malek Ashtar University of Technology Shahinshahr Isfahan 83145/115 Iran Department of Marine Science and Ocean Engineering Malek Ashtar University of Technology Shahinshahr Isfahan 83145/115 Iran Hydrodynamic Department National University of Shipbuilding (NUOS) Nikolaev 35968/241 Ukraine

在这份报纸，拖引坦克实验被进行在一个模型上学习流动的行为在水下有弓的各种各样的形状的车辆，即在免费表面运动测试的探戈舞和标准弓。为不同弗鲁德数字的全部的电阻试验性地被考虑。拖引的坦克与能通过 0.056 m/s

关键词：水下机器人航行阻力自由表面运动实验型材弗劳德数摩擦阻力系数

Manufacturing of graded titanium scaffolds using a novel space holder technique

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Bioactive Materials 2017年第4期2卷 248-252页

作者： Yunhui Chen Damon Kent Michael Bermingham Ali dehghan-manshadi Gui Wang Cuie Wen Matthew Dargusch Queensland Centre for Advanced Materials Processing and Manufacturing(AMPAM) The University of QueenslandSt.Lucia4072Australia School of Science and Engineering University of the Sunshine CoastMaroochydore DCQLD4558Australia ARC Research Hub for Advanced Manufacturing of Medical Devices Australia School of Engineering RMIT UniversityMelbourne3001Australia

To optimize both the mechanical and biological properties of titanium for biomedical implants,a highly flexible powder metallurgy approach is proposed to generate porous scaffolds with graded porosities and pore *** pellets acting as space holders were compacted with titanium powder and then removed by dissolution in water before *** morphology,pore structure,porosity and pore interconnectivity were observed by optical microscopy and *** results show that the porous titanium has porosity levels and pore size gradients consistent with their design with gradual and smooth transitions at the interfaces between regions of differing porosities and/or pore ***,the porous titanium has high interconnectivity between pores and highly spherical pore *** this article we show that this powder metallurgy processing technique,employing the novel sugar pellets as space-holders,can generate porous titanium foams with well-controlled graded porosities and pore *** method has excellent potential for producing porous titanium structures for hard tissue engineering applications.

关键词： Porous scaffolds Titanium Powder metallurgy Space holder Graded porosity

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商业纯钛等温热变形的再结晶行为

特种铸造及有色合金 2014年第4期34卷 357-359页

作者：何力佳 dehghan-manshadi A Dippenaar R J 辽宁工业大学材料科学与工程学院 Faculty of Engineering University of Wollongong

利用Gleeble3500热力模拟试验机研究了商业纯钛(Grade 2)高温下的等温热变形行为。纯钛的高温变形中发生的动态再结晶由高温淬火后金相组织的观察及应力-应变曲线所表征。结果表明,变形温度及应变速率对纯钛的变形组织及流变曲线影响较... 详细信息

利用Gleeble3500热力模拟试验机研究了商业纯钛(Grade 2)高温下的等温热变形行为。纯钛的高温变形中发生的动态再结晶由高温淬火后金相组织的观察及应力-应变曲线所表征。结果表明,变形温度及应变速率对纯钛的变形组织及流变曲线影响较大,同时,也观察到动态软化现象的发生。软化率则主要受变形温度、应变速率影响。与未变形的纯钛组织相比,变形对纯钛的组织有明显的细化作用。

关键词：商业纯钛再结晶变形晶粒细化国家留学基金委资助项目

Effect of green tea consumption in treatment of mild to moderate depression in Iranian patients living with HIV: A double-blind randomized clinical trial

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Chinese Herbal Medicines 2021年第1期13卷 136-141页

作者： dehghan manshadi Seyed Ali Mousavi Seyed Alireza Salehi Mohammad Reza Zebardast Jayran SeyedAlinaghi SeyedAhmad Rezazade Shams Ali Mirhoseinian Seyed Saeid Asadollahi-Amin Ali Department of Infectious Diseases and Tropical Medicine Imam-Khomeini Hospital ComplexTehran University of Medical SciencesTehranTehran 11519Iran Department of Infectious Diseases and Tropical Medicine Shahid Sadoughi HospitalShahid Sadoughi University of Medical Sciences and Health ServicesYazd 11519Iran Cognitive Neuroscience Linguistics Institute for Cognitive Science Studies(ICSS)Tehran 11519Iran Iranian Research Center for HIV/AIDS Iranian Institute for Reduction of High-Risk BehaviorsTehran University of Medical SciencesTehran 11519Iran Medicinal Plants Research Center Institute of Medicinal PlantsACECRTehran 11519Iran Department of Pharmacognosy Faculty of Pharmacy.Tehran University of Medical Sciences.Tehran 11519Iran

Objective: Depression affects people living with HIV(PLWH) compliance leading to poor control *** observational studies showed an anti-depression effect of green tea extract(GTE). The therapeutic effect of GTE on depression were investigated in PLWH receiving antiretroviral therapy(ART).Methods: Fifty PLWH on ART with diagnose of mild to moderate of depression, participated in a doubleblind, placebo-controlled trial and underwent 12 weeks of treatment with either 400 mg GTE capsules or placebo twice daily. The Hamilton depression scale of patients was measured before, 6 weeks and 12 weeks after treatment in two groups. The primary outcome measure was performed to evaluate the efficacy of GTE in improving depressive ***: The mean of Hamilton score showed a significant difference between the two groups after 12 weeks(P = 0.035). Repeated measures ANOVA test showed a significant effect for time ? treatment interaction on the Hamilton mean score between the two groups(P = 0.000).Conclusion: It seems the use of GTE capsules in PLWH on ART is safe and could lead to greater and more rapid improvement in depressive symptoms than placebo. Thus it can be considered as an alternative therapy for mild to moderate depression. Further studies with higher sample size and longer followup and comparisons with other antidepressive drugs are warranted.

关键词： depression green tea HIV

The Effects of Cupping Therapy on Skin’s Biomechanical Properties in Wistar Rats

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Chinese Medicine 2016年第1期7卷 25-30页

作者： Mohammad Mohsen Roostayi Taraneh Norouzali Farideh dehghan manshadi Mehdi Abbasi Alireza Akbarzadeh Baghban Physiotherapy Research Center School of Rrhabilitation Shahid Beheshti University of Medical Sciences Tehran Iran Department of Anatomy Tehran University of Medical Sciences Tehran Iran Department of Biostatics Shahid Beheshti University of Medical Sciences Tehran Iran

Cupping therapy has been widely used for clinical treatment of soft tissue lesions. The current study investigated the effects of cupping therapy on biomechanical properties of the skin in Wistar rats. 20 rats were divided into two groups: 10 in experimental and 10 in control group. Either the right or the left lower quadrants of the lumbar regions in the experimental group underwent 10 minutes daily cupping therapy for 12 days. The skin stiffness and ultimate tensile strength of all the rats were measured using tensiometer. The skin stiffness and ultimate tensile strength were decreased significantly in cupping side of the experimental group as compared with the non-cupping side and the control group. There were no significant differences between the non-cupping side of the experimental group and the control group. In conclusion, cupping therapy can be useful as a treatment method to reduce the skin stiffness and ultimate tensile strength.

关键词： Cupping Therapy Stiffness Ultimate Tensile Strength Wistar Rat Skin