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Characterization and corrosion behavior of Al-Co-rare earth(Ce-La)amorphous alloy

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Journal of rare Earths 2023年第5期41卷 771-779,I0006页

作者： Seyed Ali Mousavi Sayed Hamid Hashemi Ali Ashrafi reza Shoja razavi Seyyed Mehdi Ghazi Mirsaeed Faculty of Materials and Manufacturing Technologies Malek Ashtar University of TechnologyTehran167885611Iran Department of Materials Engineering Malek Ashtar University of TechnologyIsfahanShahin-shahrIran Department of Materials Engineering Isfahan University of TechnologyIsfahan***Iran

A new Al-based amorphous alloy with excellent corrosion resistance and high thermal stability was produced in the Al-Co-rE(Ce-La)*** this regard,two different amorphous-nanocrystalline ribbons:Al_(87.6)-Co_(6.4)-Ce_(3.8-)La_(2.2)(M_(1))and Al_(82.3)-Co_(10.1)-Ce_(4.8)-La_(2.8)(M_(2))were prepared using melt *** results reveal the supercooled liquid region(ATx)of 218℃which shows that the M2alloy has higher thermal stability in comparison to the *** M2ribbons present the superior corrosion resistance because of the formation of amorphous *** icorr,Ecorr,Epit,and Epit-Ecorrvalues of fully amorphous Al-Co-Ce-La metallic ribbons have a better trend of anti-corrosion performance compared to other crystalline and amorphous aluminum alloys.

关键词： Amorphous alloys Melt-spinning rare earth metal Corrosion behavior

Phenological Stage, Plant Biomass, and Drought Stress Affect Microbial Biomass and Enzyme Activities in the rhizosphere of Enteropogon macrostachyus

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Pedosphere 2019年第2期29卷 259-265页

作者： Kevin Z.MGANGA Bahar S.razavi Muhammad SANAULLAH Yakov KUZYAKOV Department of Soil Science of Temperate Ecosystems Institute of Soil Science University of G?ttingen Department of range and Wildlife Sciences South Eastern Kenya University Department of Agricultural Soil Science Institute of Soil Science University of G?ttingen Institute of Soil and Environmental Sciences University of AgricultureFaisalabad Institute of Environmental Sciences Kazan Federal University

Indigenous grasses have been effectively used to rehabilitate degraded African drylands. Despite their success, studies examining their effects on soil bioindicators such as microbial biomass carbon(C) and enzyme activities are scarce. This study elucidates the effects of drought stress and phenological stages of a typical indigenous African grass, Enteropogon macrostachyus, on microbial biomass and enzyme activities(β-glucosidase, cellobiohydrolase, and chitinase) in the rhizosphere soil. Enteropogon macrostachyus was grown under controlled conditions. Drought stress(partial watering) was simulated during the last 10 d of plant growth, and data were compared with those from optimum moisture conditions. The rhizosphere soil was sampled after 40 d(seedling stage), 70 d(elongation stage), and 80 d(simulated drought stress). A high root:shoot ratio at seedling stage compared with elongation and reproduction stages demonstrated that E. macrostachyus invested more on root biomass in early development, to maximise the uptake of nutrients and water. Microbial biomass and enzyme activities increased with root biomass during plant growth. Ten-day drought at reproduction stage increased the microbial biomass and enzyme activities, accompanying a decrease in binding affinity and catalytic efficiency. In conclusion, drought stress controls soil organic matter decomposition and nutrient mobilization, as well as the competition between plant and microorganisms for nutrient uptake.

关键词： African grass catalytic efficiency cellobiohydrolase chitinase β-glucosidase nutrient uptake optimum moisture soil bioindicators

Iranian healthcare professionals' perspectives about factors influencing the use of telemedicine in diabetes management

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World Journal of Diabetes 2018年第6期9卷 92-98页

作者： Haleh Ayatollahi Nader Mirani Fatemeh Nazari Narjes razavi School of Health Management and Information Sciences Iran University of Medical SciencesTehran ***Iran Zanjan University of Medical Sciences Zanjan ***Iran School of Nursing and Midwifery Iran University of Medical SciencesTehran ***Iran

AIM To identify factors influencing the use of telemedicine in diabetes management from the perspectives of hea-lthcare *** This was a quantitative study that was conducted in 2016. The participants were 240 nurses and 55 physicians from three teaching hospitals as well as from one endocrinology and metabolism research center. No sampling method was used and the data were collected by using a five-point(1 to 5) Likert scale questionnaire, which had 37 questions. Descriptive and inferential statistics(Mann-Whitney U test) were used to analyze the *** The findings showed that both physicians(4.06 ± 0.69) and nurses(4.02 ± 0.61) tended to use telemedicine technology for managing diabetes. Overall, the lowest mean value for physicians(3.79 ± 0.82) was related to the compatibility of telemedicine with other clinical activities in diabetes management. For nurses, the lowest mean value pertained to the usefulness of telemedicine in diabetes management(3.99 ± 0.53) and their attitude toward using this technology(3.99 ±0.65).CONCLUSION Although physicians and nurses agreed on using te-lemedicine technology in diabetes management, it is necessary to consider their concerns prior to the im-plementation and deployment of new technologies. This approach will help to improve the level of technology acceptance among the users.

关键词： Telemedicine Diabetes mellitus Physicians Nurses

Evaluation of hydrogen effect on the fatigue crack growth behavior of medium-Mn steels via in-situ hydrogen plasma charging in an environmental scanning electron microscope

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Journal of Materials Science & Technology 2021年第26期85卷 30-43页

作者： Di Wan Yan Ma Binhan Sun Seyed Mohammad Javad razavi Dong Wang Xu Lu Wenwen Song Department of Mechanical and Industrial Engineering Norwegian University of Science and TechnologyRichard Birkelands vei 2B7491TrondheimNorway Steel Institute(IEHK) RWTH Aachen UniversityIntzestraße 152072AachenGermany Max-Planck-Institut für Eisenforschung GmbH Max-Planck-Straße 140237DüsseldorfGermany

Fatigue crack growth(FCG)tests were conducted on a medium-Mn steel annealed at two intercritical annealing temperatures,resulting in different austenite(γ)to fe rrite(α)phase fractions and differentγ(meta-)*** in-situ hydrogen plasma charging was combined with in-situ cyclic loading in an environmental scanning electron microscope(ESEM).The in-situ hydrogen plasma cha rging increased the fatigue crack growth rate(FCGr)by up to two times in comparison with the reference tests in *** investigations showed a brittle-like crack growth or boundary cracking manner in the hydrogen environment while a ductile transgranular manner in *** both materials,the plastic deformation zone showed a reduced size along the hydrogen-influenced fracture path in comparison with that in *** difference in the hydrogen-assisted FCG of the medium-Mn steel with different microstructures was explained in terms of phase fraction,phase stability,yielding strength and hydrogen *** refined study can help to understand the FCG mechanism without or with hydrogen under in-situ hydrogen charging conditions and can provide some insights from the applications point of view.

关键词： Hydrogen embrittlement Fatigue crack growth(FCG) Electron channeling contrast imaging(ECCI) Medium-Mn steel Hydrogen plasma

ACOUSTICAL IMPrOVEMENTS WITH NATUrAL AIr VENTILATION IN THE LIU INSTITUTE FOr GLOBAL ISSUES AT THE UNIVErSITY OF BrITISH COLUMBIA

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Journal of Green Building 2011年第1期6卷 114-122页

作者： Zohreh razavi Max richter Murray Hodgson Alireza Khaleghi Stantec Architecture Ltd. Acoustics and Noise research Group SOEH-MECHUniversity of British Columbia3rd Floor2206 East MallVancouverBC V6T 1Z3 Current address:Busby Perkins+Will 1220 Homer St.VancouverBC V6B 2Y5 School of Environmental Health 3rd floor2206 East Mall and Department of Mechanical Engineering6250 Applied Science LaneUniversity of British

Low speech privacy in shared and private offices in one of the early generation of a“green”building resulted in occupants’*** problem is experienced in Liu institute with a natural-ventilation *** a system requires low air-flow resistance which is achieved by large openings which will result in noise transmission between various spaces within the *** poor acoustical quality in this building resulted in occupants’noise complaints which were further investigated by way of relevant acoustical ***-Acoustic software was utilized to modify the acoustical quality of the building without any disturbance to the *** optimized design of the transfer box above the office door was selected based on CATT-Acoustic *** acoustical measurements were conducted after installation of the transfer box above the office *** measurements’results agreed with the predictions which led to improved speech privacy to an acceptable level between the office and the corridor in Liu *** work should be done to improve the acoustical quality of natural-ventilated building to conform to ANSI standards.1 The results of this study strongly support including acoustics in“green”building designs with natural ventilation to avoid users’complaints.

关键词： “green”building natural ventilation acoustical environment noise control

Neuro-fuzzy systems in determining light weight concrete strength

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Journal of Central South University 2019年第10期26卷 2906-2914页

作者： Seyed Vahid razavi TOSEE Mehdi NIKOO Department of Civil Engineering Jundi-Shapur University of TechnologyDezfulIran Young researchers and Elite Club Ahvaz BranchIslamic Azad UniversityAhvazIran

The adaptive neuro-fuzzy inference systems(ANFIS)are widely used in the concrete *** this research,the compressive strength of light weight concrete was *** this end,the scoria percentage and curing day variables were used as the input parameters,and compressive strength and tensile strength were used as the output *** addition,100 patterns were used,70%of which were used for training and 30%were used for *** assess the precision of the neuro-fuzzy system,it was compared using two linear regression *** comparisons were carried out in the training and testing *** results revealed that the neuro-fuzzy systems model offers more potential,flexibility,and precision than the statistical models.

关键词： neuro-fuzzy systems compressive strength light weight concrete linear regression model

SYNTHESIS AND CHArACTErIZATION OF NANOSTrUCTUrED-SEGMENTED BLOCK COPOLYETHErAMIDE BASED ON NYLON6 AND POLY(ETHYLENE OXIDE)

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Chinese Journal of Polymer Science 2010年第4期28卷 597-605页

作者： Majid Peyravi Masoomeh Akhfash Ardestani Ali Akbar Babaluo Mir Karim razavi Aghjeh Seyed roohollah Pishghadam Elham Jannatdoust Nanostructure Materials research Center(NMrC) Sahand University of TechnologyP.O.Box 51335/1996TabrizI.R.Iran Chemical Engineering Department Sahand University of TechnologyP.O.Box 51335/1996TabrizI.R.Iran Institute of Polymeric Materials Sahand University of TechnologyP.O.Box 51335/1996TabrizI.R.Iran Polymer Engineering Department Sahand University of TechnologyP.O.Box 51335/1996TabrizI.R.Iran

Segmented block copolymer based on nylon6 （N6） and polyethylene oxide （PEO） with stochiometric ratio was synthesized via a two-step process. The first step represents end capping of N6 in the presence of adipic acid leading to carboxy terminated N6, and the second one is polycondensation of the latter product with PEO in the presence of catalyst and thermostabilizer to form a high molecular weight multi-block copolymer. Several methods were applied to characterize the synthesized copolyrner such as Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, differential thermal analysis, differential scanning calorimetry, X-ray diffraction and atomic force microscopy. The obtained results confirmed the multi-block structure for copolymer with a very high degree of micro-phase separation. Atomic force microscopy micrographs indicated that the morphology was the dispersion of high stiffness nanostructured polyamide （PA） domains in the amorphous region of PEO matrix, which can be very important in their performance for membrane processes.

关键词： Copolyetheramide Segmented block Nylon6 Poly(ethylene oxide) Nanomaterial

Design and Analysis of Energy Absorbent Bioinspired Lattice Structures

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Journal of Bionic Engineering 2023年第4期20卷 1670-1686页

作者： Lucrezia Greco Federica Buccino Zhuo Xu Laura Vergani Filippo Berto Mario Guagliano Seyyed Moahmmad Javad razavi Sara Bagherifard Department of Mechanical Engineering Politecnico di MilanoMilanItaly Department of Mechanical and Industrial Engineering Norwegian University of Science and TechnologyTrondheimNorway Chemical Engineering and Materials Environment Department Sapienza University of RomeRomeItaly

The increasing demand for energy absorbent structures,paired with the need for more efficient use of materials in a wide range of engineering fields,has led to an extensive range of designs in the porous forms of sandwiches,honeycomb,and *** achieve an even better performance,an ingenious solution is to learn how biological structures adjust their configurations to absorb energy without catastrophic *** this study,we have attempted to blend the shape freedom,offered by additive manufacturing techniques,with the biomimetic approach,to propose new lattice structures for energy absorbent *** this aim we have combined multiple bio-inspirational sources for the design of optimized configurations under compressive *** lattice structures are fabricated based on the designed unit cell geometries and studied using experimental and computational *** individual effect of each bio-inspired feature has been evaluated on the energy absorbance performance of the designed *** on the design parameters of the lattices,a tuning between the strength and energy absorption could be obtained,paving the way for transition within a wide range of real-life applicative scenarios.

关键词： Energy absorbance Lattice structures Bio-inspiration Fused deposition modeling Lightweight design

Effect of neat and reinforced polyacrylonitrile nanofibers incorporation on interlaminar fracture toughness of carbon/epoxy composite

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Theoretical & Applied Mechanics Letters 2018年第2期8卷 126-131页

作者： S.M.J.razavi r.Esmaeely Neisiany S.Nouri Khorasani S.ramakrishna F.Berto Department of Mechanical and Industrial Engineering Norwegian University of Science and Technology(NTNU)Richard Birkelands vei 2b7491TrondheimNorway Center for Nanofibers and Nanotechnology Department of Mechanical EngineeringNational University ofSingapore(NUS)Singapore 117576Singapore Department of Chemical Engineering Isfahan University of TechnologyIsfahan 84156-83111Iran

This paper presents an experimental investigation on fracture behavior of epoxy resin-carbon fibers composites interleaved with both neat polyacrylonitrile （PAN） nanofibers and A1203-PAN nanofibers. In particular, the paper focuses on the effect of adding Al2O3 nanopartiles in PAN nanofibers, which were incorporated in unidirectional （UD） laminates. The effectiveness of adding a thin film made of Al2O3-PAN on the fracture behavior of the carbon fiber reinforced polymer （CFrP） has been addressed by comparing the energy release rates, obtained by testing double cantilever beam （DCB） samples under mode I loading condition. A general improvement in interlaminar fracture energy of the CFrP is observed when the both neat PAN nanofibers and Al2O3-PAN nanofibers are interleaved. However, higher interlaminar strength has been observed for the samples with a thin film of Al2O3-PAN nanofibers, suggesting a better stress distribution and stress transformation from resin-rich area to reinforcement phase of hybrid composites.

关键词： Carbon fiber reinforced polymer Delamination Fracture test Nanofibers Al2O3 nanoparticles