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In-process failure analysis of thin-wall structures made by laser powder bed fusion additive manufacturing

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Journal of Materials Science & Technology 2022年第3期98卷 233-243页

作者： Apratim Chakraborty reza Tangestani Rasim Batmaz Waqas Muhammad Philippe Plamondon Andrew Wessman Lang Yuan Étienne Martin University of Waterloo 200 University Avenue WestWaterlooON N2L 3G1Canada Polytechnique Montréal 2500 Chemin de PolytechniqueMontréalQC H3T 1J4Canada University of Arizona 1235 E.James E.Rogers WayTucsonAZ 85721-0012United States University of South Carolina 301 Main StreetColumbiaSC 29208United States

Fabrication of thin-wall components using the laser powder bed fusion(LPBF)additive manufacturing(AM)technology was investigated for two“hard-to-weld”high gamma prime Ni-based superalloys RENé65(R65)and RENé108(R108).Simple block parts with wall thicknesses of 0.25 mm,1.00 mm,and5.00 mm are printed using a bidirectional laser scanning strategy without layer-wise *** with walls thinner than 5 mm fail before reaching the designated build *** indicate that reduction of limiting build height(LBh)corresponds to the reduction of part thickness and is unaffected by alloy *** the contrary,the number of internal micro-cracks along columnar grain boundaries in the build direction(BD)increases with part thickness and is significantly higher in R108 than *** findings suggest that reduced LBh in parts with thinner walls is not caused by internal micro-crack *** and finite element analysis(FEA)of the in-process thermal stresses show that the LBh trend is not explained by the conventional cracking *** suggest that part thickness affects stress distribution leading to more substantial distortion and consequent failure to add layers for continued fabrication of thinner parts.

关键词： Laser powder bed fusion Superalloys Thin-wall Residual stress Additive manufacturing

highly efficient and green synthesis of 14-aryl(alkyl)-14h-dibenzo[a,j]xanthene and 1,8-dioxooctahydroxanthene derivatives catalyzed by reusable zirconyl triflate[ZrO(OTf)_2]under solvent-free conditions

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Chinese Chemical Letters 2011年第1期22卷 9-12页

作者： Iraj Mohammadpoor-Baltork Majid Moghadam Valiollah Mirkhani Shahram Tangestaninejad hamid reza Tavakoli Department of Chemistry Catalysis DivisionUniversity of IsfahanIsfahan 81746-73441Iran

An efficient, convenient and green method has been introduced for the preparation of 14-aryl（alkyl）-14h-dibenzo[a,j]xanthene and 1,8-dioxooctahydroxanthene derivatives by the reaction of aldehydes with 2-naphthol and 5,5-dimethyl-1,3-cyclohexanedione, respectively, in the presence of ZrO（OTf）2 as a reusable catalyst under solvent-free conditions. In addition, very short reaction times, excellent yields, straightforward procedure, and relatively non-toxicity of the catalyst are other noteworthy advantages of the present method.

关键词： Xanthenes Zirconyl triflate Aldehydes 2-Naphthol Reusable catalyst

Reliability-based maintenance scheduling of hydraulic system of rotary drilling machines

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International Journal of Mining Science and Technology 2013年第5期23卷 771-775页

作者： Mohammad Javad Rahimdel Mohammad Ataei reza khalokakaei Seyed hadi hoseinie Faculty of Mining Engineering Sahand University of Technology Faculty of Mining Engineering Geophysics and PetroleumShahrood University of Technology Division of Operation and Maintenance Engineering Lulea University of Technology

hydraulic system has a critical and important role in drilling *** failure in this system leads to problems in power system and machine *** the failure cannot be prevented entirely,it is important to minimize its *** is one of the most effcient and important method to study safe operation probability of hydraulic *** this research,the reliability of hydraulic system of four rotary drilling machines in Sarcheshmeh Copper Mine in Iran has been *** data analysis shows that the time between failures(TBF)of Machines A and C obey the Weibull(2P)and Weibull(3P)distribution,***,the TBF of Machines B and D obey the lognormal *** regard to reliability plots of hydraulic systems,preventive reliability-based maintenance time intervals for 80%reliability levels for machines in this system are 10 h.

关键词： Reliability Drilling hydraulic Maintenance

Epidemiological transition of colorectal cancer in developing countries: Environmental factors, molecular pathways, and opportunities for prevention

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World Journal of Gastroenterology 2014年第20期20卷 6055-6072页

作者： Faraz Bishehsari Mahboobeh Mahdavinia Michele Vacca reza Malekzadeh Renato Mariani-Costantini Division of Gastroenterology Robert H Lurie Comprehensive Cancer Center Department of Medicine Northwestern University Feinberg School of Medicine Chicago IL 60611 United States Division of Allergy-Immunology Department of Medicine Northwestern University Feinberg School of Medicine Chicago IL 60611 United States Medical Research Council-human Nutrition Research MRC-HNR Cambridge CB1 9NL United Kingdom Institute of the Metabolic Science IMS Cambridge CB2 0QQ United Kingdom Digestive Oncology Research Center Digestive Disease Research Institute Tehran University of Medical Sciences Shariati Hospital Tehran *** Iran Unit of General Pathology Aging Research Center G. d’Annunzio University Foundation 66100 Chieti Italy Department of Medical Oral and Biotechnological Sciences G. d’Annunzio University 66100 Chieti Italy

Colorectal cancer(CRC)is one of the leading causes of cancer and cancer-related mortality *** disease has been traditionally a major health problem in industrial countries,however the CRC rates are increasing in the developing countries that are undergoing economic *** environmental risk factors,mainly changes in diet and life style,have been suggested to underlie the rise of CRC in these *** and lifestyle impinge on nuclear receptors,on the intestinal microbiota and on crucial molecular pathways that are implicated in intestinal *** this respect,the epidemiological transition in several regions of the world offers a unique opportunity to better understand CRC carcinogenesis by studying the disease phenotypes and their environmental and molecular associations in different *** data from these studies may have important implications for the global prevention and treatment of CRC.

关键词： Colorectal cancer Developing countries Environment Diet Nuclear receptors Gut microbiota

Applying machine learning techniques to predict laminar burning velocity for ammonia/hydrogen/air mixtures

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Energy and AI 2023年第3期13卷 207-218页

作者： Cihat Emre Ustun Mohammad reza herfatmanesh Agustin Valera-Medina Amin Paykani School of Physics Engineering and Computer ScienceUniversity of HertfordshireHatfieldAL109ABUnited Kingdom College of Physical Sciences and Engineering Cardiff UniversityCardiffCF243AAUnited Kingdom

Ammonia utilisation in internal combustion engines has attracted wide interest due to the current trend toward decarbonisation,as ammonia is a zero-carbon fuel with different combustion properties to *** laminar burning velocity(LBV)is a fundamental property of fuels with a significant effect on the combustion processes and accurate calculations and measurements of the LBV over a wide range of fuel blends,pressures and flow conditions is a time-consuming,complicated *** main goal of the current study is to predict the LBV of Nh_(3)/h_(2)/air mixtures using a hybrid machine learning(ML)approach based on a training dataset consisting of both the experimental LBV values and additional data obtained from numerical simulations with a detailed kinetic *** ML model training data is collected from existing experimental LBV in the literature for Nh_(3)/h_(2)/air ***,synthetic data is generated using one-dimensional(1D)simulations to reduce data inhomogeneity and increase accuracy of the ML *** total,24 different ML algorithms are tested to find the best model both for the experimental and the hybrid *** results suggest that both Gaussian Process Regression(GPR)and Neural Networks(NNs)can be utilised to predict LBV of Nh_(3)/h_(2)/air mixtures with reasonable *** hybrid ML model achieved a coefficient of determination of R^(2)=***,hybrid ML model hyperparameters are optimised to achieve a coefficient of determination of R^(2)=*** was also found that ML can speed up LBV computation from 9500 to 27000 times compared to 1D simulations with a reduced mechanism.

关键词： Machine learning Ammonia hydrogen Laminar burning velocity Combustion

Genetic analysis of polymerase complex(PA,PB1 and PB2) genes of h9N2 avian influenza viruses from Iran(1999 to 2009)

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Asian Pacific Journal of Tropical Biomedicine 2012年第11期2卷 858-862页

作者： Masoud Soltanialvar reza Goodarzi Farshad Akbarnejad Department of Avian Diseases Faculty of AgricultureIslamic Azad University Department of Avian Pathology Islamic Azad University

Objective:To determine the molecular characterization of Polymerase complex(PA,PB1 and PB2) genes of h9N2 avian influenza viruses and the genetic relalionsliip of Iranian h9N2 viruses and other Asian ***:The Polymerase complex(PA,PBl and PB2) genes from seven isolates of h9N2 viruses isolated from commercial chickens in Iran during 2008-2009 were amplified(by RT-PCR method) and *** sequences(Open Reading Frame: orf) of the PA,PBl and PB2 genes were used for phylogenetic tree ***:Most PB2 and PA genes of the h9N2 viruses isolated in 2008-2009 belonged to the unknown avian sublineage which grouped with the 2004 Pakistani h7N3 *** PBl genes of Iranian viruses indicated greater genetic diversity and shared a high level of similarity to PBl genes from either hS or h7 subtypes with compared to established h9N2 Eurasian ***:Our findings demonstrated that the h9N2 viruses in Iran exhibit striking reassortment which has led to the generation of new genotypes.

关键词： Genetic analysis Polymerase complex Avian influenza Iran

Comparative numerical study on the child head injury under different child safety seat angles

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Theoretical & Applied Mechanics Letters 2019年第4期9卷 260-263,I0005页

作者： reza Razaghi hasan Biglari Mojtaba hasani Alireza Karimi Department of Mechanical Engineering University of TabrizTabrizIran Basir Eye health Research Center TehranIran Department of Biomedical Engineering Faculty of EngineeringUniversity of IsfahanIsfahanIran Department of Mechanical Engineering Kyushu UniversityFukuoka 819-0395Japan

It has been shown that annually around 1250 children younger than 15 years old die in traffic *** number of children who also injured as a consequence of car accidents is noticeably *** to the ECE-R44 regulation the safety of children in the cars,the use of a child safety seat(CSS)is highly *** a CSS would dramatically diminish the injuries of traffic ***,the posture,especially the angle,of a child when seating on a seat may also affect the amount of injury occurs during the *** has been revealed that during the accident only few children remained seated in the standard position,and most of them whether slouched or slanted and turned their head to the side-support of the *** positions,such as leaning forward,escaping from the harness or holding feet were also *** study aimed to perform a finite element(FE)study to figure out what angle of seating would result in the least amount of injury to the child head in a typical car crash under the speed of 47 km/*** do that,a 1.5 years old child dummy(a dummy representing the anthropometry of a 1.5 years old child)has been accommodated on a seat under the angles of 15°,30°,and 45°.The results *** resulted displacements in the head after the accident were also calculated at X,Y,and Z *** results in this regard indicated a higher displacement at X direction whereas the lowest one was seen at Y *** results have implications not only for understanding the amount of injury to the child head after the accident under different seating angles,but also for giving an insight to the CSS industries and families to choose the right seating posture for the child in the car to reduce the severity of injury.

关键词： Child head injury Child safety seat Accident Finite element

Methanol to propylene： the effect of iridium and iron incorporation on the hZSM-5 catalyst

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Frontiers of Chemical Science and Engineering 2012年第3期6卷 253-258页

作者： Alireza MOhAMMADrezaEI Sadegh PAPARI Mousa ASADI Abas NADERIFAR reza GOLhOSSEINI National Petrochemical Company Petrochemical Research & Technology Company (NPC-RT) Tehran 14358-84711 Iran Department of Chemical an'd Petroleum Engineering Sharif University of-Technology Tehran 11365-9465 Iran Department of Chemical Engineering Amirkabir University of Technology Tehran 15914 Iran

The effect of iridium and iron impregnation of hZSM-5 zeolite on the methanol to propylene reaction （MTP） was investigated. The selectivities ofpropylene and other hydrocarbons, and the conversion of methanol were compared by performing MTP in a small pilot plant. The results indicate that hZSM-5 zeolite modified by iron and iridium increased propylene selectivity by 6.3% and 8%, respectively. The selectivity ofpropylene was higher for Ir/ h-ZSM-5 than for Fe/h-ZSM-5, where Fe/h-ZSM-5 was more stable than Ir/h-ZSM-5. Analytic techniques, including X-ray diffraction, BET surface area, temperature-programmed desorption of ammonia, and inductively coupled plasma atomic emission spectroscopy, were used to characterize the modified zeolites as well as the parent zeolites.

关键词： hZSM-5 promoter iridium iron MTP

以磷酸二氢铵为催化剂一锅法合成 3,4-二氢嘧啶-2-酮(英文)

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催化学报 2012年第4期33卷 659-665页

作者： reza TAYEBEE Behrooz MALEKI Malihe GhADAMGAhI Department of Chemistry School of SciencesHakim Sabzevari University

A one-pot three component Biginelli condensation of different substituted aromatic and aliphatic aldehydes with ethyl acetoacetate and urea to the respective 3,4-dihydropyrimidin-2-(1h)-ones under solvent-free conditions that is simple,effective,and environmentally friendly was *** dihydrogen phosphate(Nh4h2PO4) was used as a non-toxic,inexpensive,and easily available *** facile reaction condition and simple isolation and purification procedures of this method make it a good option for the synthesis of dihydropyrimidinones.

关键词：化学催化高压高温