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Experimental investigation of flow and distortion mitigation by mechanical vortex generators in a coupled serpentine inlet-turbofan engine system

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Chinese Journal of Aeronautics 2020年第5期33卷 1375-1391页

作者： Iman MAGHSOUDI mohammad ali VAZIRY Mostafa MAHMOODI Department of Aerospace Malek-Ashtar University of TechnologyTehran 158751774Iran Department of Aerospace Malek-Ashtar University of TechnologyIsfahanShahinshahr 115/83145Iran

The performance of compact,aggressive ducts in advanced propulsion systems is limited by the internal flow separation coupled with the formation of secondary counter-rotating vortices that give rise to intensive flow distortions at the duct *** experimental investigation was conducted to study the flow field and passive suppression of flow separation and Aerodynamic Interface Plane (AIP) distortion in a serpentine air inlet *** were performed by a turbofan engine at several Engine Operating Points (EOPs) from 56%(idle) to 100%(max).A large total pressure deficit region arose at the upper part of the AIP,which was associated with the upper surface flow *** the new mechanical S-type vortex generators in two longitudinal positions (VGl and VG2),separation and loss were diminished at the upper part of the duct and *** VG2 arrangement attained the maximum reductions in distortion coefficients which were 73.72%,60.7% and 37.8% in DC(90°),DC(60°) and△P_C/P metrics,*** the next step of the study,some unsteady aspects of the flow field were analyzed inside the *** separation onset and reattachment points were determined by the standard deviation of static pressure on the upper *** AIP spectral distribution showed that the boundary of low pressure and high pressure recovery regions was dominated by the maximum ***,the PSD diagram of several probes at AIP revealed the vortex shedding frequency and its higher harmonics at separation *** energy content of distinct unsteady spectral features in the bare configuration was significantly reduced using VGs,which showed the improvement of flow at the duct exit.

关键词： Distortion coefficient Power spectral density Serpentine inlet Total pressure Vortex generators

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Slope stability of an unsaturated embankment with and without natural pore water salinity subjected to rainfall infiltration

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岩土力学 2022年第8期43卷 2136-2148页

作者： SADEGHI Hamed KOLAHDOOZ ali AHMADI mohammad-Mehdi Department of Civil Engineering Sharif University of TechnologyTehran ***Iran

Natural soils contain a certain amount of salt in the form of dissolved ions or electrically charged atoms,originated from the long-term erosion by acidic *** dissolved salt poses an extra osmotic water potential being normally neglected in laboratory measurements and numerical ***,ignorance of salinity may result in overestimation of stability,and the design may not be as conservative as ***,this research aims to first experimentally examine the influence of pore water salinity on water retention curve and saturated permeability of natural dispersive loess under saline and desalinated ***,the measured parameters are used for stability analyses of a railway embankment in an area subjected to regional rainfall ***,a numerical parametric study is carried out to explore the significance of different rainfall schemes,construction patterns,and anisotropic permeability on the factor of *** reveal that desalinization suppresses the water retention capability,which in turn results in a tremendous declination of unsaturated hydraulic *** the natural saline embankment,rainfall can hardly infiltrate into the desalinated embankment due to the lower ***,the factor of safety for natural saline conditions drops notably,while only marginal changes occur in the case of the desalinated embankment.

关键词： slope stability water salinity osmotic potential dispersive loess rainfall patterns

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Modeling the Facies of Reservoir Using Seismic Data with Missing Attributes by Dissimilarity Based Classification

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Journal of Earth Science 2017年第4期28卷 703-708页

作者： Majid Bagheri mohammad ali Riahi Institute of Geophysics University of TehranTehran 14115-6466Iran

Using seismic attributes as features for classification in feature space, in various aims such as seismic facies analysis, is conventional for the purpose of seismic interpretation. But sometimes seismic data may have no attributes or it is hard to define a small and relevant set of attributes in some applica- tions. Therefore, employing techniques that perform facies modeling without using attributes is neces- sary. In this paper we present a new method for facies modeling of seismic data with missing attributes that called dissimilarity based classification. In this method, classification is based on dissimilarities and facies modeling will be done in dissimilarity space. In this space dissimilarities consider as new features instead of real features. A support vector machine as a powerful classifier was employed in both feature space （feature-based） and dissimilarity space （feature-less） for facies analysis. The proposed feature-less and feature-based classification is applied on a real seismic data from an Iranian oil field. Facies model- ing using seismic attributes provide better results, but the feature-less classification outcome is also satis- factory and the facies correlation is acceptable. Indeed, the power of attributes to discriminate different facies causes to that facies analysis using attributes provide more reliable results comparing to feature- less facies analysis.

关键词： facies analysis dissimilarity feature seismic attributes classification support vector- classifier.

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Kinetics and mechanism of titanium hydride powder and aluminum melt reaction

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International Journal of Minerals,Metallurgy and Materials 2012年第2期19卷 165-172页

作者： ali Rasooli Mehdi Divandari Hamid Reza Shahverdi mohammad ali Boutorabi School of Metallurgy and Materials Engineering Member of Center of Excellence for Advanced Material and Processing (CEAMP) Iran University of Science and Technology Tehran 16844 Iran Department of Materials Faculty of Engineering Tarbiat Modaress University Tehran 14115-143 Iran

Based on the measurement of the released hydrogen gas pressure （PH2）, the reaction kinetics between TiH2 powder and pure aluminum melt was studied at various temperatures. After cooling the samples, the interface of TiH2 powder and aluminum melt was studied. The results show that the-time curves have three regions; in the first and second regions, the rate of reaction conforms zero and one order, respectively; in the third region, the hydrogen gas pressure remains constant and the rate of reaction reaches zero. The main factors that control the rate of reaction in the first and second regions are the penetration of hydrogen atoms in the titanium lattice and the chemical reaction between molten aluminum and titanium, respectively. According to the main factors that control the rate of reaction, three temperature ranges are considered for the reaction mechanism：（a） 700-750°C, （b） 750-800°C, and （c） 800-1000°C. In the first temperature range, the reaction is mostly under the control of chemical reaction; at the temperature range of 750 to 800°C, the reaction is controlled by the diffusion and chemical reaction; at the third temperature range （800-1000°C）, the dominant controlling mechanism is diffusion.

关键词： titanium hydride aluminum reaction kinetics reaction rate constants

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On the potential of alyssum as an herbal fiber to improve the filtration and rheological characteristics of water-based drilling muds

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Petroleum 2022年第4期8卷 509-515页

作者： mohammad Amin Ebrahimi ali Sanati Department of Petroleum Engineering Amirkabir University of TechnologyTehranIran Petroleum and Petrochemical Engineering School Hakim Sabzevari UniversitySabzevarIran

Drilling muds play an important role in drilling and production operations so that the degree of success in such operations is determined by the proper design of these *** optimize drilling operations and avoid excessive expenditure,it is essential to prepare a drilling mud that is both cheap and *** additives are typically used in drilling systems to improve these fluids'capabilities in terms of hole cleaning capacity,filtration control,viscosity,yield point,heat transfer,***,environmental concerns,cost of production,and availability are always considered challenging *** study introduces an eco-friendly herbal fiber in powder and regular forms as a potential alternative to other chemical *** do so,alyssum homolocarpum seed mucilage was added with different concentrations to the water-based drilling muds,and its rheological behavior,filtration control,and the induced formation damage were examined and the optimum concentration was *** results of this study revealed the advantages of the drilling muds formulated with alyssum in terms of filtration control,rheology,formation damage,and greenness.

关键词： Drilling fluid alyssum Herbal fiber Rheology Filtration contro

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Performance improvement of ionic surfactant flooding in carbonate rock samples by use of nanoparticles

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Petroleum Science 2016年第4期13卷 725-736页

作者： mohammad ali Ahmadi James Sheng Department of Petroleum Engineering Ahwaz Faculty of Petroleum Engineering Petroleum University of Technology Petroleum Department Texas Tech University

Various surfactants have been used in upstream petroleum processes like chemical flooding. Ultimately, the performance of these surfactants depends on their ability to reduce the interfacial tension between oil and water. The surfactant concentration in the aqueous solution decreases owing to the loss of the surfactant on the rock surface in the injection process. The main objective of this paper is to inhibit the surfactant loss by means of adding nanoparticles. Sodium dodecyl sulfate and silica nanoparticles were used as ionic surfactant and nanoparticles in our experiments, respectively. AEROSIL~？ 816 and AEROSIL~？200 are hydrophobic and hydrophilic nanoparticles. To determine the adsorption loss of the surfactant onto rock samples, a conductivity approach was used. Real carbonate rock samples were used as the solid phase in adsorption experiments. It should be noted that the rock samples were water wet. This paper describes how equilibrium adsorption was investigated by examining adsorption behavior in a system of carbonate sample（solid phase） and surfactant solution（aqueous phase）. The initial surfactant and nanoparticle concentrations were 500–5000 and 500–2000 ppm, respectively. The rate of surfactant losses was extremely dependent on the concentration of the surfactant in the system, and the adsorption of the surfactant decreased with an increase in the nanoparticle concentration. Also, the hydrophilic nanoparticles are more effective than the hydrophobic nanoparticles.

关键词： Adsorption Hydrophobic silica nanoparticles Hydrophilic silica nanoparticles Ionic surfactant Carbonate rock

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A novel ensemble model for predicting the performance of a novel vertical slot fishway

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Frontiers of Structural and Civil Engineering 2020年第6期14卷 1418-1444页

作者： Aydin SHISHEGARAN mohammad SHOKROLLAHI ali MIRNOROLLAHI Arshia SHISHEGARAN mohammadreza mohammad KHANI Deparlment of Water and Environmental Engineering School of Civil EngineeringIran University of Science and TechnologyTehran ***Iran Department of Water and Environmental Engineering School of Civil EngineeringSemnan UniversitySemnan 35131-19111Iran Department of Water and Enironmental Engineering School of Civil EngineeringIslamic Azad University Central Tehran BranchTehran ***Iran School of Progress Engineering Iran University of Science and TechnologyTehran ***Iran

We investigate the performance of a novel vertical slot fishway by employing finite volume and surrogate *** linear regression,multiple log equation regression,gene expression programming,and combinations of these models are employed to predict the maximum turbulence,maximum velocity,resting area,and water depth of the middle pool in the *** statistical parameters and error terms,including the coefficient of determination,root mean square error,normalized square error,maximum positive and negative errors,and mean absolute percentage error were employed to evaluate and compare the accuracy of the *** also conducted a parametric *** independent variables include the opening between bafles(OBB),the ratio of the length of the large and small baffles,the volume flow rate,and the angle of the large *** results show that the key parameters of the maximum turbulence and velocity are the volume flow rate and OBB.

关键词： novel vertical slot fishway parametric study finite volume method ensemble model gene expression programming

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Epidemiological observations of invasive group B Streptococcus infections in six major hospitals in Peninsular Malaysia

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Asian Pacific Journal of Tropical Medicine 2024年第9期17卷 384-391页

作者： AbdulRahman Muthanna Mohd Nasir Mohd Desa Nurul Asyikin Abdul Rahman Nurul Diana Dzaraly Nurul Hana Zainal Baharin Nur Afiza Aziz Chua Hui Shan Zalina Ismail Lailatul Akmar Mat Nor Marlindawati Mohd ali Nur Hanani Ahmad mohammad Noor Amal Azmai Syafinaz Amin-Nordin Department of Biomedical Sciences Faculty of Medicine and Health SciencesUniversiti Putra Malaysia43400 SerdangSelangorMalaysia School of Biology Faculty of Applied SciencesUniversiti Teknologi MARANegeri Sembilan72000 Kuala PilahMalaysia Department of Oral Biology&Biomedical Sciences Faculty of DentistryMAHSA University42610 JenjaromSelangorMalaysia School of Bioscience Faculty of Pharmacy and Biomedical SciencesMAHSA University42610 JenjaromSelangorMalaysia Department of Pathology Sultanah Aminah Hospital80100 Johor BahruJohorMalaysia Department of Pathology Melaka General Hospital75400 MelakaMalaysia Department of Medical Microbiology and Immunology Faculty of MedicineUniversiti Kebangsaan Malaysia56000 CherasKuala LumpurMalaysia Department of Pathology Sultan Idris Shah Serdang Hospital43000 KajangSelangorMalaysia Department of Pathology Tuanku Ja'afar Hospital70300 SerembanNegeri SembilanMalaysia Department of Pathology Sungai Buloh Hospital47000 Sungai BulohSelangorMalaysia Department of Biology Faculty of ScienceUniversiti Putra Malaysia43400 SerdangSelangorMalaysia Aquatic Animal Health and Therapeutics Laboratory Institute of BioscienceUniversiti Putra Malaysia43400 SerdangSelangorMalaysia Department of Medical Microbiology Faculty of Medicine and Health SciencesUniversiti Putra Malaysia43400 SerdangSelangorMalaysia Department of Medical Microbiology Sultan Abdul Aziz Shah HospitalUniversiti Putra MalaysiaPersiaran MARDI-UPM43400SelangorMalaysia

Objective:To address the lack of research on invasive group B Streptococcus(GBS)infections in Malaysia and Southeast Asia through a comprehensive analysis of GBS isolates obtained from ***:Medical records from patients with GBS infection isolated from the sterile site,such as blood and cerebrospinal fluid from 14 July 2019 to 15 December 2020,were reviewed from six major hospitals in Peninsular *** criteria were invasive GBS,sterile sites and non-repeated GBS isolated from the same patients in the same *** isolates were re-identified for GBS and ***:A total of 118 patients were eligible,with a majority of non-pregnant adults(76.3%).Over half of the patients(62.7%)had underlying medical conditions,with diabetes as the most common disease,followed by respiratory disease,renal disease,cardiovascular disease and skin and soft tissue *** most common manifestations were sepsis,followed by soft tissue abscess,diabetic foot ulcer,wet gangrene and *** overall mortality was 7.6%.The most common serotype was serotype桋.Conclusions:Invasive GBS infection among non-pregnant adults showed a rising trend,particularly among diabetic *** study underscores the importance of reducing risk factors and highlights the necessity of developing GBS vaccination as a preventive strategy for both infants and adults.

关键词： Streptococcus agalactiae Group B Streptococcus Invasive GBS infections Malaysia

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Fischer-Tropsch synthesis over ruthenium-promoted Co/Al_2O_3 catalyst with different reduction procedures

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Journal of Natural Gas Chemistry 2010年第5期19卷 503-508页

作者： ali Karimi ali Nakhaei Pour Farshad Torabi Behnam Hatami Ahmad Tavasoli mohammad Reza Alaei mohammad Irani Research Institute of Petroleum Industry (RIPI) Gas Research Division

The effect of reduction procedure on catalyst properties, activity and products selectivity of ruthenium-promoted Co/γ-Al2O3 catalyst in Fischer-Tropsch synthesis （FTS） was investigated. Catalyst samples were reduced with different reduction gas compositions and passivated before being characterized by TPR and XRD techniques. Different activity and product selectivity analyses were also performed. These results showed that the catalyst dispersion, particle size, and the degree of reduction changed with different reduction gas compositions, which were resulted from the water partial pressures in reduction process that give varying degrees of interaction with the support. It has been suggested that the FTS activity of cobalt catalyst was directly dependent on the catalyst reducibility. A reduction gas with a molar ratio of H2Prle = 1 was used to prevent the formation of Co-support compound during catalyst reduction.

关键词： Fischer-Tropsch synthesis cobalt reducibility activity C5+ selectivity

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Synthesis and Infrared Spectra Computation of Sterically Congested 2,2-Disubstituted Indane-1,3-dione Derivatives

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Chinese Journal of Structural Chemistry 2011年第4期30卷 568-574页

作者： Seyed mohammad Shoaei ali Reza Kazemizadeh ali Ramazani Department of Chemistry Islamic Azad UniversityZanjan Branch

Sterically congested 2,2-disubstituted indane-1,3-dione derivatives have been syn-thesized and characterized by 1H NMR,13C NMR,FT-IR and elemental *** B3LYP/HF calculations for computation of IR spectra have been carried out for the title compounds at the 6-31G and 6-311＋＋G basis set *** vibrational frequencies have been assigned and compared with the experimental FT-IR spectra and they are supported each other.

关键词： vibrational frequency DFT HF FT-IR spectra 2 2-disubstituted indane-1 3-dione isocyanide

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