检索结果-南通市图书馆

Experimental determination of gas holdup and volumetric mass transfer coefficient in a jet bubbling reactor

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2021年第6期34卷 61-67页

作者： Mostafa Abbasian-arani Mohammad Sadegh Hatamipour amir Rahimi Chemical Engineering Department University of IsfahanIsfahanIran

The hydrodynamics and mass transfer characteristics of a lab-scale jet bubbling reactor(JBR)including the gas holdup,volumetric mass transfer coefficient and specific interfacial area were assessed experimentally investigating the influence of temperature,pH and superficial gas *** reactor diameter and height were 11 and 30 cm,*** was equipped with a single sparger,operating at atmospheric pressure,20 and 40℃,and two pH values of 3 and *** height of the liquid was 23 cm,while the superficial gas velocity changed within 0.010-0.040 m·s^(-1)*** were conducted with pure oxygen as the gas phase and saturated lime solution as the liquid *** liquid-side volumetric mass transfer coefficient was determined under unsteady-state oxygen absorption in a saturated lime *** gas holdup was calculated based on the liquid height change,while the specific interfacial area was obtained by a physical method based on the bubble size distribution(BSD)in different superficial gas *** results indicated that at the same temperature but different pH,the gas holdup variation was negligible,while the liquid-side volumetric mass transfer coefficient at the pH value of 6 was higher than that at the pH=*** a constant pH but different temperatures,the gas holdup and the liquid-side volumetric mass transfer coefficients at 40℃were higher than that of the same at 20℃.A reasonable and appropriate estimation of the liquid-side volumetric mass transfer coefficient(kla)in a pilot-scale JBR was provided which can be applied to the design and scale-up of JBRs.

关键词： Jet bubbling reactor Liquid-side volumetric mass transfer coefficient Gas holdup Specific interfacial area Experimental analysis

Energy efficiency of small buildings with smart cooling system in the summer

在线全文

学校读者我要写书评

暂无评论

Frontiers in Energy 2022年第4期16卷 651-660页

作者： Yazdan DANESHVAR Majid SABZEHPARVAR Seyed amir Hossein HASHEMI Department of Civil Engineering Qazvin BranchIslamic Azad UniversityQazvin 314199-15195Iran Department of Industrial Engineering Collage of EngineeringKaraj BranchIslamic Azad UniversityKaraj 31499-68111Iran

In this paper,a novel cooling control strategy as part of the smart energy system that can balance thermal comfort against building energy consumption by using the sensing and machine programming technology was *** this goal,a general form of a building was coupled by the smart cooling system(SCS)and the consumption of energy with thermal comfort cooling of persons simulated by using the EnergyPlus software and compared with similar buildings without *** the beginning of the research,using the data from a survey in a randomly selected group of hundreds and by analyzing and verifying the results of the specific relationship between the different groups of people in the statistical society,the body mass index(BMI)and their thermal comfort temperature were obtained,and the sample building was modeled using the EnergyPlus *** result show that if an intelligent ventilation system that can calculate the thermal comfort temperature was used in accordance with the BMI of persons,it can save up to 35%of the cooling load of the building yearly.

关键词： smart home heating and cooling systems saving energy optimal consumption of energy

Effect of intermetallic compounds on the fracture behavior of dissimilar friction stir welding joints of Mg and Al alloys

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2019年第10期26卷 1285-1298页

作者： amir Hossein Baghdadi Zainuddin Sajuri Nor Fazilah Mohamad Selamat Mohd Zaidi Omar Yukio Miyashita amir Hossein Kokabi Centre for Materials Engineering and Smart Manufacturing Faculty of Engineering and Built EnvironmentUniversiti Kebangsaan Malaysia43600 UKM BangiSelangor 43600Malaysia Department of Mechanical Engineering Nagaoka University of TechnologyNagaoka940-2188Japan Department of Materials Science and Engineering Sharif University of TechnologyTehran 11365-11155Iran

Joining Mg to Al is challenging because of the deterioration of mechanical properties caused by the formation of intermetallic compounds(IMCs) at the Mg/Al interface. This study aims to improve the mechanical properties of welded samples by preventing the fracture location at the Mg/Al interface. Friction stir welding was performed to join Mg to Al at different rotational and travel speeds. The microstructure of the welded samples showed the IMCs layers containing Al12Mg17(γ) and Al3Mg2(β) at the welding zone with a thickness(< 3.5 μm). Mechanical properties were mainly affected by the thickness of the IMCs, which was governed by welding parameters. The highest tensile strength was obtained at 600 r/min and 40 mm/min with a welding efficiency of 80%. The specimens could fracture along the boundary at the thermo-mechanically affected zone in the Mg side of the welded joint.

关键词： aluminum alloy magnesium alloy intermetallic compounds dissimilar welded joint friction stir welding

Enhanced Chimp Optimization Algorithm Using Attack Defense Strategy and Golden Update Mechanism for Robust COVID-19 Medical Image Segmentation

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2024年第4期21卷 2086-2109页

作者： amir Hamza Morad Grimes Abdelkrim Boukabou Samira Dib Non Testing Destructive Laboratory Faculty of TechnologyUniversity of Jijel18000JijelAlgeria Laboratory of Renewable Energy Faculty of TechnologyUniversity of Jijel18000JijelAlgeria

Medical image segmentation is a powerful and evolving technology in medical *** fact,it has been identified as a very effective tool to support and accompany doctors in their fight against the spread of the coronavirus(COVID-19).Various techniques have been utilized for COVID-19 image segmentation,including Multilevel Thresholding(MLT)-based meta-heuristics,which are considered crucial in addressing this ***,despite their importance,meta-heuristics have significant ***,the imbalance between exploration and exploitation,as well as premature convergence,can cause the optimization process to become stuck in local optima,resulting in unsatisfactory segmentation *** this paper,an enhanced War Strategy Chimp Optimization Algorithm(WSChOA)is proposed to address MLT *** strategies are incorporated into the traditional Chimp Optimization *** update mechanism that provides diversity in the ***,the attack and defense strategies are incorporated to improve the search space leading to avoiding local *** experimental results were conducted by comparing WSChoA with recent and well-known algorithms using various evaluation metrics such as Feature Similarity Index(FSIM),Structural Similarity Index(SSIM),Peak signal-to-Noise Ratio(PSNR),Standard deviation(STD),Freidman Test(FT),and Wilcoxon Sign Rank Test(WSRT).The results obtained by WSChoA surpassed those of other optimization techniques in terms of robustness and accuracy,indicating that it is a powerful tool for image segmentation.

关键词： Image processing Segmentation Optimization Chimp Golden update mechanism Attack-defense strategy COVID-19

High salt and fat intake, inflammation, and risk of cancer

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers in Biology 2017年第6期12卷 387-391页

作者： amir Abdoli Department of Parasitology Faculty of Medical Sciences Tarbiat Modares University Tehran Iran

Background Inflammatory conditions are involved in the pathophysiology of cancer. Recent findings have revealed that excessive salt and fat intake is involved in the development of severe inflammatory *** literature search was performed on various online databases (PubMed, Scopus, and Google Scholar) regarding the roles of high salt and fat intake in the induction of inflammatory reactions and their roles in the etiopathogenesis of *** The results indicate that high salt and fat intake can induce severe inflammatory conditions. However, various inflammatory conditions have been strongly linked to the development of cancer. Hence, high salt and fat intake might be involved in the pathogenesis of cancer progression via putative mechanisms related to inflammatory *** Reducing salt and fat intake may decrease the risk of cancer.

关键词： cancer inflammation nutrition salt fat

The anisotropic grain size effect on the mechanical response of polycrystals:The role of columnar grain morphology in additively manufactured metals

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2024年第14期181卷 240-256页

作者： S.amir H.Motaman Dilay Kibaroglu Institut für Eisenhüttenkunde RWTH Aachen UniversityIntzestraße 1Aachen 52072Germany

Additively manufactured(AM)metals exhibit highly complex microstructures,particularly in terms of grain morphology which typically features heterogeneous grain size distribution,irregular and anisotropic grain shapes,and the so-called columnar *** conventional morphological descriptors based on grain shape idealization are generally inadequate for representing complex and anisotropic grain mor-phology of AM *** primary aspect of microstructural grain morphology is the state of grain boundary spacing or grain size whose effect on the mechanical response is known to be *** this paper,we formally introduce the notion of axial grain size from which we derive mean axial grain size,effective grain size,and grain size anisotropy as robust morphological descriptors ca-pable of effectively representing highly complex grain *** instantiated a discrete sample of polycrystalline aggregate as a representative volume element(RVE)featuring random crystallographic orientation and misorientation ***,the instantiated RVE incorporates the typical mor-phological features of AM microstructures including distinctive grain size heterogeneity and anisotropic grain size owing to its pronounced columnar grain *** ensured that any anisotropy ob-served in the macroscopic mechanical response of the instantiated sample primarily originates from its underlying anisotropic grain *** RVE was then employed for mesoscale full-field crystal plasticity simulations corresponding to uniaxial tensile deformation along various axes via a spectral solver and a physics-based crystal plasticity constitutive model which was developed,calibrated,and validated in ear-lier *** the numerical analyses,we isolated the contribution of anisotropic grain size to the anisotropy in the mechanical response of polycrystalline aggregates,particularly those with the charac-teristic complex grain morphology of AM *** contribution c

关键词： Axial grain size Grain size anisotropy Strain hardening anisotropy Grain morphology Morphological texture Columnar grains Additive manufacturing

Health concerns of veterans with high-level lower extremity amputations

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Military Medical Research 2019年第2期6卷 117-127页

作者： Elahe Faraji Mostafa Allami Nafiseh Feizollahi amir Karimi amir Yavari Mohammadreza Soroush Majid Moudi Janbazan Medical and Engineering Research Center(JMERC) NO.17Farrokh St.Moghaddas Ardebily Ave.Chamran HighwayTehranIran

Background: To identify health concerns of veterans with high-level lower extremity ***: Through a cross-sectional study, general practitioners, an orthopedic specialist, psychologists, psychiatrists,physiotherapist and prosthetists examined 100 veterans using a short-form health-related quality of life questionnaire(SF-36) that assessed their ability to perform activities of daily living(ADL), instrumental activities of daily living(IADL) and life satisfaction(SWLS) after hip disarticulation or hemi-pelvectomy amputations. The assessment tool was designed to gather statistically useful information about their health ***: The means of the Physical Component Summary(PCS), Mental Component Summary(MCS), SWLS, ADL and IADL were 48.58±29.6, 33.33±22.0, 19.30±7.7, 48.10±10.5 and 5.08±1.8, respectively. Somatization, depression, and anxiety were the most prevalent disorders;among the veterans who were visited by psychiatrists, 11.6% had a history of hospitalization in a psychiatry section, and 53.2% had a psychiatric visit. Regardless of their injury in battle, 34% of veterans were hospitalized. Hearing problems were common, and about four-fifths of the participants suffered from at least one orthopedic condition. Neuroma(49%) was the most common stump-related complication during orthopedic evaluations, though the prevalence of phantom pain was 81% during the pain assessment. A total of 87% of the participants had a history of wearing a prosthesis, but only 29% wore a prosthesis at the time of the present *** Canadian-type of prosthesis was uncomfortable and not useful(27%) and excessively heavy(10%) according to the ***: Understanding veterans’ characteristics and special needs are important to make sure that enough facilities and services are afforded to them. These findings emphasize the importance of paying close attention to different dimensions of health in veterans and can help health providers identify health needs

关键词： War-related trauma High level lower extremity amputation Health needs assessment

Evaluating the efficiency of the Dong model in determining fire vulnerability in Iran’s Zagros forests

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry Research 2019年第4期30卷 1447-1458页

作者： Sabri Baqer Rasooli amir Eslam Bonyad Department of Geography College of EducationUniversity of GarmianKalarKurdistan RegionIraq Department of Forestry Faculty of Natural ResourcesUniversity of GuilanSowmeh SaraIran

Recent fires in Iran’s Zagros forests have inflicted heavy,extensive losses to the environment,forests,villages,and forest inhabitants,resulting in a huge financial loss to the *** the increasing risk of fire and the resulting losses,it has become ever more necessary to design and develop efficient fire control and prediction *** present study utilizes the Dong model to develop a map of areas vulnerable to fire in the Zarivar lake forests as a representative sample of Zagros *** model uses as its inputs some of the most significant factors(such as vegetation,physiographic features,and the human component)that affect the fire occurrence and *** assigned weights to each factor based on the model,all maps were overlapped in the ArcMap and then the region was divided into five *** results showed that 74%of the region was located in three classes:highly vulnerable,vulnerable,and medially *** validate the proposed zoning map it was compared with a map based on real data obtained from previous *** results showed that 81%of fire incidents were located in highly vulnerable,vulnerable and medially vulnerable ***,the findings indicated a medium to a high degree of fire vulnerability in Zarivar Lake forests.

关键词： Dong model Fire incidents Zarivar lake Zoning

Controllable reactor based hybrid HVDC breaker

在线全文

学校读者我要写书评

暂无评论

High Voltage 2020年第5期5卷 543-548页

作者： amir Heidary Mehdi Bigdeli Kumars Rouzbehi Department of Electrical Engineering Zanjan BranchIslamic Azad UniversityZanjanIran 2Department of System Engineering and Automatic ControlUniversity of SevilleSevilleSpain

Short circuit fault occurrence in high-voltage DC (HVDC) systems causes extremely high currents in a fast raising time that does not experience current zero-crossing. To protect HVDC systems/grids against fault current, fast HVDC breaker is an essential equipment. This study presents the design procedure of a novel HVDC breaker based on solid-state controllable reactor which is able to reduce the fault current's rate of rise and fault current amplitude to less than grid nominal current in the breaking process. The main achievement of the proposed HVDC breaker is that not only breaker does not encounter fault current, but also none of the series HVDC equipment is influenced by the fault. The designed breaker performance is studied by PSCAD/EMTPS, and then the simulation results are validated by the developed laboratory experimental setup.

关键词： fault EMTP nominal