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Wear behavior and dry sliding tribological properties of ultra-fine grained Al5083 alloy and boron carbide-reinforced Al5083-based composite at room and elevated temperatures

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Transactions of Nonferrous Metals Society of China 2021年第1期31卷 74-91页

作者： Matin SAESSI ali alizadeh alireza ABDOLLAHI Department of Composites Malek-Ashtar University of TechnologyTehranIran Department of Materials and Manufacturing Processes Malek-Ashtar University of TechnologyTehranIran Metallic Materials Research Center Malek-Ashtar University of TechnologyTehranIran

Tribological behavior and wear mechanisms of mechanically milled Al5083 alloy and Al5083−5wt.%B4C composite at room temperature and 200°C were *** revealed that due to the oxidative wear at room temperature,a mechanically mixed layer(MML)was formed to protect the surface of the *** 80 N of load at room temperature,the milled Al5083 and the Al5083−5wt.%B4C samples showed evidence of abrasion with limited volume *** this case,the wear rates were 5.8×10−7 and 4.4×10−7 mm3/(m·N),*** 200°C and under 80 N of applied load,severe wear occurred in the milled Al5083 sample,and wear rate reached 10.8×10−7 mm3/(m·N)while the Al5083−5wt.%B4C sample showed mild wear with local 3-body abrasion and the wear rate reached 5.3×10−7 mm3/(m·N).Strengthening mechanisms such as dislocation pinning and the Hall−Petch theory,high hardness and the load transfer effect were crucial in determining the wear behavior of the Al5083−5wt.%B4C *** the other hand,the milled Al5083 sample represented a relatively high wear rate at 200°C,which seemed to be related to the local grain growth and a drop in its hardness.

关键词： tribological behavior oxidative wear mechanically mixed layer wear rate Hall−Petch theory

Processing, characterization, room temperature mechanical properties and fracture behavior of hot extruded multi-scale B_4C reinforced 5083 aluminum alloy based composites

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Transactions of Nonferrous Metals Society of China 2017年第6期27卷 1233-1247页

作者： ali alizadeh alireza ABDOLLAHI Mohammad Javd RADFAR Faculty of Materials & Manufacturing Processes Malek Ashtar University of Technology Faculty of Engineering South Tehran Branch Islamic Azad University

Microstructural characteristics and mechanical behavior of hot extruded Al5083/B4C nanocomposites were ***5083and Al5083/B4C powders were milled for50h under argon atmosphere in attrition mill with rotational speed of400r/*** increasing the elongation,milled powders were mixed with30%and50%unmilled aluminum powder(mass fraction)with meanparticle size of>100μm and100μm unmilled particles reduced the tensile strength and ductility at the same *** increasing the content of unmilledparticles failure mechanism changed from brittle to ductile.

关键词： Al5083 alloy metal matrix composite boron carbide multi-scale composite hot extrusion mechanical milling

Comparison between the Effects of Alfentanil, Lidocaine and Their Composition in Controlling the Hemodynamic Responses at the Time of Awake Extubation of Patients

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International Journal of Clinical Medicine 2017年第6期8卷 430-438页

作者： ali alizadeh Mahmoud Aghaziarati Nasim Zarin Assistant Professor of Medical Science University Qazvin Iran Anesthesiologist of Medical Science University Tehran Iran Assistant Professor of Anesthesiology Medical Science University Qazvin Iran

Background and aim: Instability in the hemodynamic symptoms has been common at the time of extubation in patients and the cause to create the side effects. The aim of this research was to study the effect of injection of Alfentanil, Lidocaine and their composition in reduction of side effects arising from extubation. Materials and methods: 172 patients (20 - 40 years old) that referred to Shahid Rajaee Hospital in 2014 and had been under the orthopedic surgery, were divided randomly and by using colored cards into four equal groups (43 patients in each group). Alfentanil (5 microgram/kilogram) was injected to the first group. The second group received Lidocaine (1 milligram/ kilogram). The composition of these two drugs was injected to the third group and the normal equal volume of Saline was injected to the fourth group which was the control group. The means of systolic and diastolic blood pressure, average arterial pressure and the number of heartbeat at the time of extubation were measured and registered 1, 5, 10, 15 and 20 minutes after extubation. Also, the amount of situation of bucking after extubation was registered in the groups. Results: The demographic results were similar in all groups. The mean of systolic blood pressure and number of heartbeats in the group of Alfentanil and composition of Alfentanil-Lidocaine had significant reduction (p 0.05). The situation of bucking in three treatment groups had significant reduction in comparison with control group. Conclusion: Alfentanil and composition of it with Lidocaine both had caused reducing the systolic blood pressure and heartbeats.

关键词： Alfentanil Lidocaine Hemodynamic Responses

Chronic effects of stretching on range of motion with consideration of potential moderating variables:A systematic review with meta-analysis

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Journal of Sport and Health Science 2024年第2期13卷 186-194页

作者： Andreas Konrad Shahab alizadeh Abdolhamid Daneshjoo Saman Hadjizadeh Anvar Andrew Graham ali Zahiri Reza Goudini Chris Edwards Carina Scharf David George Behm Institute of Human Movement Science Sport and HealthGraz UniversityGraz A-8010Austria School of Human Kinetics and Recreation Memorial University of NewfoundlandSt.John’sNL A1C 5S7Canada Department of Sport Injuries and Corrective Exercises Faculty of Sport SciencesShahid Bahonar University of KermanKerman 76169-13439Iran

Background:It is well known that stretch training can induce prolonged increases in joint range of motion(ROM).However,to date more information is needed regarding which training variables might have greater influence on improvements in ***,the purpose of this metaanalysis was to investigate the effects of stretch training on ROM in healthy participants by considering potential moderating variables,such as stretching technique,intensity,duration,frequency,and muscles stretched,as well as sex-specific,age-specific,and/or trained state-specific adaptations to stretch ***:We searched through PubMed,Scopus,Web of Science,and SportDiscus to find eligible studies and,finally,assessed the results from 77 studies and 186 effect sizes by applying a random-effect ***,by applying a mixed-effect model,we performed the respective subgroup *** find potential relationships between stretch duration or age and effect sizes,we performed a ***:We found a significant overall effect,indicating that stretch training can increase ROM with a moderate effect compared to the controls(effect size=-1.002;Z=-12.074;95%confidence interval:-1.165 to-0.840;p<0.001;I^(2)=74.97).Subgroup analysis showed a significant difference between the stretching techniques(p=0.01)indicating that proprioceptive neuromuscular facilitation and static stretching produced greater ROM than did ballistic/dynamic ***,there was a significant effect between the sexes(p=0.04),indicating that females showed higher gains in ROM compared to ***,further moderating analysis showed no significant relation or ***:When the goal is to maximize ROM in the long term,proprioceptive neuromuscular facilitation or static stretching,rather than ballistic/dynamic stretching,should be *** to consider in future research as well as sports practice is that neither volume,intensity,nor frequency of stretching were

关键词： Flexibility Long-term stretching Stretch training

The Effect of Oral <i>Melissa officinalis</i>on Serum Oxidative Stress and Second Degree Burn Wounds Healing

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Health 2014年第18期6卷 2517-2524页

作者： Masumeh Abbasdust Arbastan Kobra Rahzani Davood Hekmatpou Shaban ali alizadeh Mohammad Rafiei ali Akbar Malekirad Nursing Department Arak University of Medical Sciences Arak Iran Faculty of Nursing and Midwifery Arak University of Medical Sciences Arak Iran Faculty of Medicine Arak University of Medical Sciences Arak Iran Department of Social Medicine Arak University of Medical Sciences Arak Iran Department of Biology Payame Noor University Tehran Iran

For this aim, this study conducted in order to assess the effect of lemon balm as an antioxidant on second degree wound healing and oxidative stress serum of burning patients. To meet the aim, 60 patients with 15 to 50 burn percent with the age range of 18 to 50 were invited after considering to inclusion criteria by the researchers. First they have been put by non-probable method and then random method in two groups of experiment (30 people) and control (30 people). After that, experiment group in addition to ordinary treatment has been used Melissa officinalis (lemon balm) plant two times a day for two weeks (1.5 g in 100 cc). Oxidative stress parameters included serum total antioxidant and the rate of malondialdehyde (MDA) that is one of total production of lipid peroxidation have been measured in patients’ blood sample in first and last parts of the study. The wound position has been studied by using standard wound BATES-JENSEN assessment tool in first, seventh and fifteenth days of study. In order to analyze data, independent sample t-test, paired sample t-test and repeated measurement variance have been used. These results indicated that the state of wound healing in experimental group was better than that in control group. Results indicated that mean of serum total antioxidant had been increased in both groups. The index of lipid peroxidation at the end of period has been increased in experiment group than control group, whether this index is significantly decreased at the end of 15 days in experimental group. According to the results of this study, the effect of Melissa officinalis (lemon balm) plant was effective in increasing lipid peroxideative in better states of second degree burn wound healing.

关键词： Burn Wounds Healing Lemon Balm Oxidative Stress

Genuine entanglement under squeezed generalized amplitude damping channels with memory

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Chinese Physics B 2024年第2期33卷 158-163页

作者： Mazhar ali Department of Electrical Engineering Faculty of EngineeringIslamic University MadinahMadinah 107Saudi Arabia

We study genuine entanglement among three qubits undergoing a noisy process that includes dissipation, squeezing,and decoherence. We obtain a general solution and analyze the asymptotic quantum states. We find that most of these asymptotic states can be genuinely entangled depending upon the parameters of the channel, memory parameter, and the parameters of the initial states. We study Greenberger–Horne–Zeilinger(GHZ) states and W states, mixed with white noise,and determine the conditions for them to be genuinely entangled at infinity. We find that for these mixtures, it is possible to start with a bi-separable state(with a specific mixture of white noise) and end with genuine entangled states. However, the memory parameter μ must be very high. We find that in contrast to the two-qubit case, none of the three-qubit asymptotic states for n → ∞ are genuinely entangled.

关键词： genuine entanglement squeezed thermal baths multipartite states

Heat transfer analysis in particle-laden flows using the immersed boundary method

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Particuology 2024年第7期90卷 394-403页

作者： ali Abbas Zaidi Department of Mechanical Engineering University of Manitoba75A Chancellors CircleWinnipegR3T 5V6Canada

This paper investigates an efficient immersed boundary method(IBM)for multiple-core CPU machines with local grid refinement for the calculation of heat transfer between fluids and finite-sized *** fluid momentum equations are solved by using the fractional step method,while the energy equation is solved by employing the second-order Adams-Bashforth *** efficient load balancing between the CPU cores,the coupling between particles and fluid is obtained by applying the body force in the fluid equations,which depends on the solid volume fraction of particles contained in each grid cell,and then by linearly interpolating the particle temperature and velocity on the fluid grid cell(in place of the delta function commonly used in literature).Several test cases from the literature are studied,and good agreement is observed between the simulation results and the ***,a scaling study on multiple core machines is performed,demonstrating the proposed IBM's capabilities for a significant reduction in processing time.

关键词： Heat transfer Immersed boundary method Particle resolved direct numerical simulations Fluid solid interactions

Simulation of the deformable lateral boundaries in biaxial test using DEM

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Particuology 2024年第5期88卷 161-175页

作者： ali Momeni Barry Clarke Yong Sheng ali Hassanpour WSP 3 Wellington PlaceLeedsLS1 4APUK Hull University HullHU6 7RXUK School of Civil Engineering University of LeedsLeedsLS2 9JTUK School of Computer Science University of HullHullHU6 7RXUK School of Chemical and Process Engineering University of LeedsLeedsLS2 9JTUK

Applying the discrete element method(DEM)in soil mechanics can provide abundant information at the particle-scale and facilitates illustration of the macro-mechanical behaviour of soils based on the inter-particle *** triaxial test is one of the most common laboratory methods to study the macro-mechanical behaviour of particulate materials such as ***,many problems in geotechnical design can be assumed and simplified as a plane strain *** a biaxial test can be conducted to reproduce the macro-mechanical behaviour of soil,where the sample is enclosed by two horizontal rigid platens and a vertical latex membrane,which is a deformable continuous element and allows the enclosed specimen to deform freely while maintaining confining stress during *** paper presents an algorithm to represent physical and mechanical characteristics of latex membrane in the 2D DEM simulation of biaxial test using the PFC^(2D) *** investigate the impact of the lateral boundary conditions on the micro-macro mechanical behaviours of soil samples,two sets of DEM biaxial tests are conducted,*** rigid and deformable lateral boundary *** DEM modeling results indicate that the lateral boundary conditions have a significant effect on the micro-scale fabric properties,thickness and inclination of the shear *** comparison between these two simulations also demonstrates that the lateral boundary conditions play a major role in the peak and post-peak stress-strain behaviours as well as the dilation and critical state behaviours of granular soils.

关键词： Discrete element method Biaxial test Deformable boundaries Shear band Critical state Fabric anisotropy Geometrical stability index

Sensing the heavy water concentration in an H_(2)O-D_(2)O mixture by solid-solid phononic crystals

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Chinese Physics B 2024年第4期33卷 493-498页

作者： Mohammadreza Rahimi ali Bahrami Optoelectronic and Nanophotonics Research Laboratory(ONRL) Faculty of Electrical EngineeringSahand University of TechnologyTabrizIran

A new method based on phononic crystals is presented to detect the concentration of heavy water(D_(2)O)in an H_(2)O-D_(2)O *** have been obtained and analyzed in the concentration range of 0%-10%and 90%-100%D_(2)O.A proposed structure of tungsten scatterers in an aluminum host is *** order to detect the target material,a cavity region is considered as a sound wave resonator in which the target material with different concentrations of D_(2)O is *** changing the concentration of D_(2)O in the H_(2)O-D_(2)O mixture,the resonance frequency undergoes a frequency *** 1%change in D_(2)O concentration in the H_(2)O-D_(2)O mixture causes a frequency change of about 120 *** finite element method is used as the numerical method to calculate and analyze the natural frequencies and transmission spectra of the proposed *** performance evaluation index shows a high Q factor up to 1475758 and a high sensitivity up to 13075,which are acceptable values for sensing *** other figures of merit related to the detection performance also indicate high-quality performance of the designed sensor.

关键词： phononic crystals sensor H_(2)O-D_(2)O mixture cavity