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Three-Dimensional Numerical Investigation of the Separation Process in a Vortex Tube at Different Operating Conditions

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Journal of Marine Science and Application 2016年第2期15卷 157-165页

作者： seyed ehsan rafiee M.M. Sadeghiazad Department of Mechanical Engineering Urmia University of Technology Urmia P.O. Box 57155-419 Iran

Air separators provide safe, clean, and appropriate air flow to engines and are widely used in vehicles with large engines such as ships and submarines. In this operational study, the separation process in a Ranque-Hilsch vortex tube cleaning （cooling） system is investigated to analyze the impact of the operating gas type on the vortex tube performance; the operating gases used are air, nitrogen, oxygen, carbon dioxide and nitrogen dioxide. The computational fluid dynamic model used is equipped with a three-dimensional structure, and the steady-state condition is applied during computations. The standard k-c turbulence model is employed to resolve nonlinear flow equations, and various key parameters, such as hot and cold exhaust thermal drops, and power separation rates, are described numerically. The results show that nitrogen dioxide creates the greatest separation power out of all gases tested, and the numerical results are validated by good agreement with available experimental data. In addition, a comparison is made between the use of two different boundary conditions, the pressure-far-field and the pressure-outlet, when analyzing complex turbulent flows in the air separators. Results present a comprehensive and practical solution for use in future numerical studies.

关键词： vortex tube air separator separation process operatinggas numerical simulation

Estimating Network Connectedness of Financial Markets and Commodities

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Journal of Systems Science and Systems Engineering 2020年第5期29卷 572-589页

作者： ehsan Bagheri seyed Babak Ebrahimi Financial Engineering Group Faculty of Industrial EngineeringK.N.Toosi University of TechnologyTehranIran

We investigate the directional volatility and return network connectedness among stock,commodity,bond,currency and cryptocurrency *** period of study covers Feb 2006 until August *** utilize and expand Diebold and Yilmaz(20142015)connectedness measurement;accordingly,in the variance decomposition structure,we use Hierarchical Vector Autoregression(HVAR)to estimate high dimensional networks more *** empirical results show that markets are highly connected,especially during *** stock markets are the net receiver of shocks,while European and American stock markets are the net transmitter of shocks to other *** pairwise connectedness results suggest that among stock markets,DAX-CAC 40,FTSE 100-CAC 40 and S&P 500-S&P_TSX index are more integrated through connectedness than the *** other markets,WTI crude oil-Brent crude oil,30-Year bond and 10-Year bond,Dollar Index futures-EUR/USD have notable *** terms of cryptocurrencies,they contribute insignificantly to other markets and are highly integrated with each *** and cryptocurrencies seem to be good choices for investors to hedge during a crisis.

关键词： Financial markets network connectedness econometrics commodity

Droplets diameter distribution using maximum entropy formulation combined with a new energy-based sub-model

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Chinese Journal of Chemical Engineering 2016年第11期24卷 1625-1630页

作者： seyed Mostafa Hosseinalipour Hadiseh Karimaei ehsan Movahednejad Energy and Environmental Lab Dpt Mech. Eng. Iran University of Science and Technology 16846-13114 Narmak Tehran lran University of California Berkeley USA

The maximum entropy principle(MEP) is one of the first methods which have been used to predict droplet size and velocity distributions of liquid sprays. This method needs a mean droplets diameter as an input to predict the droplet size distribution. This paper presents a new sub-model based on the deterministic aspects of liquid atomization process independent of the experimental data to provide the mean droplets diameter for using in the maximum entropy formulation(MEF). For this purpose, a theoretical model based on the approach of energy conservation law entitled energy-based model(EBM) is presented. Based on this approach, atomization occurs due to the kinetic energy loss. Prediction of the combined model(MEF/EBM) is in good agreement with the available experimental data. The energy-based model can be used as a fast and reliable enough model to obtain a good estimation of the mean droplets diameter of a spray and the combined model(MEF/EBM) can be used to well predict the droplet size distribution at the primary breakup.

关键词： Mean droplets diameter Energy conservation Maximum entropy formulation (MEF) Size distribution Statistical thermodynamics Mathematical modeling

An outlook on coronavirus disease 2019 detection methods

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Journal of Pharmaceutical Analysis 2022年第2期12卷 205-214页

作者： Zahra Hassani Nejad Fataneh Fatemi seyed ehsan Ranaei Siadat Department of Biochemistry Institute of Biochemistry and BiophysicsUniversity of TehranTehran***Iran Department of Protein Research Protein Research CenterShahid Beheshti UniversityTehran***Iran Sobhan Recombinant Protein Company Research and Development DepartmentTehran***Iran

Diagnostic testing plays a fundamental role in the mitigation and containment of coronavirus disease 2019(COVID-19),as it enables immediate quarantine of those who are infected and contagious and is essential for the epidemiological characterization of the virus and estimating the number of infected cases *** of viral infections,such as COVID-19,can be achieved through two general approaches:nucleic acid amplification tests(NAATs)or molecular tests,and serological or antibody-based *** genetic material of the pathogen is detected in NAAT,and in serological tests,host antibodies produced in response to the pathogen are *** methods of diagnosing COVID-19 include radiological imaging of the lungs and in vitro detection of viral *** review covers different approaches available to diagnosing COVID-19 by outlining their advantages and shortcomings,as well as appropriate indications for more accurate testing.

关键词： COVID-19 Diagnostics Nucleic acid amplification tests Serological tests

Enucleation and evisceration: indications, complications and clinicopathological correlations

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International Journal of Ophthalmology(English edition) 2014年第4期7卷 677-680页

作者： Ali Kord Valeshabad Masood Naseripour Rajab Asghari seyed Hamid Parhizgar seyed ehsan Parhizgar Mohammad Taghvaei Shahin Miri Department of Ophthalmology and Visual Sciences University of Illinois at Chicago Department of Ophthalmology Eye Research CenterRassoul Akram Hospital Iran University of Medical Sciences School of Medicine Tehran University of Medical Sciences Department of Ophthalmology Baqiyatallah University of Medical Sciences Department of Neurosurgery Imam Khomeini HospitalTehran University of Medical Sciences

·AIM: To assess main indications, postoperative complications and clinicopathological correlation of ocular enucleation-evisceration.·METHODS: A total of 107 subjects who underwent enucleation and/or evisceration and received hydroxyapatite implants(Scleral wrap or mesh) were assessed. For each patient clinicopathological data was collected which included demographic information,clinical history, primary clinical diagnosis, main cause of ophthalmic surgery(traumatic, non-traumatic), type of surgical procedure(enucleation, evisceration) and pathological report. Patients’ postoperative clinical visits were checked for procedure-related complications during first year after surgery.·RESULTS: One hundred and seven patients(male:65.4%; mean age: 26y) underwent enucleation(n=100) or evisceration(n =7) due to traumatic(n =41) and non-traumatic(n =66) causes. Disfiguring painful blind eye was the most common indication of surgery(66.4%),followed by leukocoria(19.6%) and endophthalmitis(4.7%). The main types of injury included firecracker,traffic and work accidents, and sharp object perforating injury. In 53(80.3%) subjects in non-traumatic group the initial clinical diagnosis matched the histopathologicalresults. Malignant tumors(retinoblastoma: 47.5%,malignant melanoma: 27.3%) were the most common pathological diagnoses followed by phthisis bulbi(25.8%).The most common procedure-related complications were major eye discharge(39.6%), and implant exposure and discharge(20.8%).·CONCLUSION: Trauma and malignant tumors are the leading causes of enucleation-evisceration. Despite developing new techniques and materials, enucleation is still associated with considerable postoperative complications.

关键词： enucleation evisceration retinoblastoma malignant melanoma ocular injury

Neurological manifestations related to Crohn’s disease:a boon for the workforce

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Gastroenterology Report 2019年第4期7卷 291-297,I0002页

作者： Reza Nemati Somayeh Mehdizadeh Hooman Salimipour ehsan Yaghoubi Zeinab Alipour seyed Masoud Tabib Majid Assadi Department of Neurology Bushehr University of Medical SciencesBushehrIran The Persian Gulf Tropical Medicine Research Center Bushehr University of Medical SciencesBushehrIran Department of Pathology Rasul-e Akram HospitalIran University of Medical SciencesTehranIran Department of Neurology Yasuj University of Medical SciencesYasujIran Department of Gastroenterology and Hepatology Bushehr University of Medical SciencesBushehrIran The Persian Gulf Nuclear Medicine Research Center Bushehr University of Medical SciencesBushehrIran

The neurological manifestations of Crohn’s disease and its prevalence are not well ***,we report five patients of confirmed Crohn’s disease with different neurological *** neurological presentations include anterior ischemic optic neuropathy,myelopathy,posterior reversible encephalopathy syndrome,chronic inflammatory demyelinating polyneuropathy,and chronic axonal sensory and motor *** manifestations should be kept in mind in the assessment of Crohn’s disease.

关键词： Crohn’s disease idiopathic inflammatory bowel disease neurological manifestation

Editor in Chief’s Note on the Green Hydrogen Fuel from Solar / Wind Power

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Journal of Management Science & Engineering Research 2019年第1期2卷 1-4页

作者： seyed ehsan Hosseini Combustion and Sustainable Energy Laboratory(ComSEL) Department of Mechanical EngineeringArkansas Tech University1811 N Boulder AveRussellvilleAR72801USA

Renewable and sustainable energy has an evolving story as the ongoing trade war in the word is influencing crude oil ***,the global warming is an inevitable consequence of the worldwide increasing rate of fossil fuel utilization which has persuaded the governments to invest on the clean and sustainable energy *** recent years,the cost of green energy has tumbled,making the price of renewables competitive to the fossil ***,the hydrogen fuel is still extremely expensive compared to the crude oil price,investigations about clean hydrogen fuel production and utilization has been developed significantly which demonstrate the importance of the hydrogen fuel in the *** article aims to scrutinize the importance of green hydrogen fuel production from solar/wind energy.

关键词： Solar Wind Hydrogen Electrolysis Fuel Cell

Phylogeography,genetic variability and structure of Acanthamoeba metapopulations in Iran inferred by 18S ribosomal RNA sequences:A systematic review and meta-analysis

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Asian Pacific Journal of Tropical Medicine 2017年第9期10卷 855-863页

作者： Adel Spotin Hamid Reza Moslemzadeh Mahmoud Mahami-Oskouei ehsan Ahmadpour Maryam Niyyati seyed Hossein Hejazi Fatemeh Memari Jafar Noori Immunology Research Center Tabriz University of Medical SciencesTabrizIran Department of Parasitology and Mycology Faculty of MedicineTabriz University of Medical SciencesTabrizIran Department of Medical Parasitology and Mycology School of MedicineShahid Beheshti University of Medical SciencesTehranIran Department of Parasitology and Mycology School of MedicineIsfahan University of Medical SciencesIsfahanIran

Objective: To verify phylogeography and genetic structure of Acanthamoeba populations among the Iranian clinical isolates and natural/artificial environments distributed in various regions of the ***: We searched electronic databases including Medline, Pub Med, Science Direct, Scopus and Google Scholar from 2005 to 2016. To explore the genetic variability of Acanthamoeba sp, 205 sequences were retrieved from keratitis patients, immunosuppressed cases and environmental sources as of various geographies of ***: T4 genotype was the predominant strain in Iran, and the rare genotypes belonged to T2, T3, T5(Acanthamoeba lenticulata), T6, T9, T11, T13 and T15(Acanthamoeba jacobsi).A total of 47 unique haplotypes of T4 were identified. A parsimonious network of the sequence haplotypes demonstrated star-like feature containing haplogroups IR6(34.1%) and IR7(31.2%) as the most common haplotypes. In accordance with the analysis of molecular variance, the high value of haplotype diversity(0.612–0.848) of Acanthamoeba T4 represented genetic variability within populations. Neutrality indices of the 18 S ribosomal RNA demonstrated negative values in all populations which represented a considerable divergence from neutrality. The majority of genetic diversity belonged to the infected contact lens and dust samples in immunodeficiency and ophthalmology wards, which indicated potential routes for exposure to a pathogenic Acanthamoeba sp. in at-risk individuals. A pairwise fixation index(FST) was from low to high values(0.024 33–0.418 92). The statistically FST points out that T4 is genetically differentiated between north-west, north-south and centralsouth metapopulations, but not differentiated between west-central, west-south, centralsouth, and north-central ***: An occurrence of IR6 and IR7 displays that possibly a gene flow of Acanthamoeba T4 occurred after the founder effect or bottleneck experience through ecological changes or host mobility

关键词： Acanthamoeba metapopulations Genetic variability Gene flow Molecular phylogeny Iran

Zero-Inflated Negative Binomial Regression Model with Right Censoring Count Data

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材料科学与工程（中英文B版） 2011年第4期1卷 551-554页

作者： seyed ehsan Saffari Robiah Adnan Department of Mathematics Faculty of Science Universiti Teknologi Malaysia Malaysia