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Comparison of selective flocculation of low grade goethitic iron ore fines using natural and synthetic polymers and a graft copolymer

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International Journal of Minerals,Metallurgy and Materials 2018年第5期25卷 498-504页

作者： Kichakeswari Tudu Sagar Pal N.R.Mandre Department of Fuel and Mineral Engineering Indian Institute of Technology (Indian School of Mines) Polymer Chemistry Laboratory Department of Applied ChemistryIndian Institute of Technology (Indian School of Mines)

This study aims to beneficiate low grade goethitic iron ore fines using a selective flocculation process. Selective flocculation studies were conducted using different polymers such as starch amylopectin(AP), poly acrylic acid(PAA), and a graft copolymer(AP-g-PAA). The obtained results were analyzed; they indicate the enhancement of the iron ore grade from 58.49% to 67.52% using AP-g-PAA with a recovery of 95.08%. In addition, 64.45% Fe with a recovery of 88.79% was obtained using AP. Similarly, using PAA, the grade increased to 63.46% Fe with a recovery of 82.10%. The findings are also supported by characterizing concentrates using X-ray diffraction(XRD) and electron probe microanalysis(EPMA) techniques.

关键词： low grade iron ore fines selective flocculation graft copolymer amylopectin(AP) poly acrylic acid(PAA)

Microstructure, properties and hot workability of M300 grade maraging steel

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Defence Technology（防务技术） 2018年第1期14卷 51-58页

作者： K.V.A.Chakravarthi N.T.B.N.Koundinya S.V.S.Narayana Murty B.Nageswara Rao Materials and Mechanical Entity Vikram Sarabhai Space Centre Research scholar Department of Mechanical Engineering K L University Department of Metallurgical Engineering and Materials Science Indian Institute of Technology Department of Mechanical Engineering K L University

This paper presents isothermal uniaxial compression test results of M300 grade maraging steel over a wide range of temperatures(900 e1200℃) and strain rates(0.001 e100 s^(-1)) to examine hot deformability and concurrent microstructural evolution. Processing map is generated and indicated the optimum processing parameters in the temperature range of 1125℃-1200℃ and strain rate range of 0.001 e0.1 s^(-1). High values of the efficiency of power dissipation, microstructural observations and EBSD results indicate softening mechanism to be the occurrence of dynamic recrystallisation. Material constants in a constitutive relation are evaluated from the flow stress data useful in computer modelling.

关键词： Activation energy Constitutive relation Hot deformation M300 grade maraging steel Processing map

Effect of fusion welding processes on tensile properties of armor grade, high thickness, non-heat treatable aluminium alloy joints

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Defence Technology（防务技术） 2019年第3期15卷 353-362页

作者： K. Vasu H. Chelladurai Addanki Ramaswamy S. Malarvizhi V. Balasubramanian Department of Mechanical Engineering PDPM Indian Institute of Information Technology Design and Manufacturing Jabalpur Madhya pradesh 482005 India Centre for Materials Joining & Research (CEMAJOR) Department of Manufacturing Engineering Annamalai University Annamalai Nagar -(P.O) Tamil nadu 608002 India

AA5059 is one of the high strength armor grade aluminium alloy that finds its applications in the military vehicles due to the higher resistance against the armor piercing (AP) threats. This study aimed at finding the best suitable process among the fusion welding processes such as gas tungsten arc welding (GTAW) and gas metal arc welding (GMAW) by evaluating the tensile properties of AA5059 aluminium alloy joints. The fracture path was identified by mapping the low hardness distribution profile (LHDP) across the weld cross section under tensile loading. Optical and scanning electron microscopies were used to characterize the microstructural features of the welded joints at various zones. It is evident from the results that GTAW joints showed superior tensile properties compared to GMAW joints and this is primarily owing to the presence of finer grains in the weld metal zone (WMZ) and narrow heat-affected zone (HAZ). The lower heat input associated with the GTAW process effectively reduced the size of the WMZ and HAZ compared to GMAW process. Lower heat input of GTAW process results in faster cooling rate which hinders the grain growth and reduces the evaporation of magnesium in weld metal compared to GMAW joints. The fracture surface of GTAW joint consists of more dimples than GMAW joints which is an indication that the GTAW joint possess improved ductility than GMAW joint.

关键词： Gas tungsten arc welding Gas metal arc welding Armor grade aluminium alloy Tensile properties Microhardness

Thermophoresis and concentration effects in a fourth grade peristaltic flow with convective walls

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Journal of Central South University 2017年第7期24卷 1654-1662页

作者： Ali Aamir Asghar S Awais M Department of Mathematics COMSATS Institute of Information TechnologyAttock 43600Pakistan Department of Mathematics COMSATS Institute of Information TechnologyIslamabad 44000Pakistan Department of Mathematics King Abdulaziz UniversityJeddah 21432Saudi Arabia

In this investigation,we have studied the peristaltic fluid flow in an asymmetric channel with convective *** grade fluid model has been utilized in view of the fact that the results of all other differential type models can be deduced as the special *** effects of heat and mass transfer are *** thermophoresis effects occur in the energy *** heat and mass boundary conditions have been given special *** wave length and low Reynolds number approximations are utilized for the *** analytic solutions for the velocity,temperature and concentration profiles are calculated using perturbation technique and elaborated in the form of graphical observations for various physical quantities.

关键词： fourth grade fluid convective boundary conditions pumping and trapping peristalsis

Relative Syzygies and grade of Modules

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Acta Mathematica Sinica,English Series 2013年第3期29卷 489-504页

作者： Zeng Feng LIU Zhao Yong HUANG Department of Mathematics Nanjing University

Recently, Takahashi established a new approximation theory for finitely generated modules over commutative Noetherian rings, which unifies the spherical approximation theorem due to Auslan- der and Bridger and the Cohen-Macaulay approximation theorem due to Auslander and Buchweitz. In this paper we generalize these results to much more general case over non-commutative rings. As an application, we establish a relation between the injective dimension of a generalized tilting module w and the finitistic dimension with respect to w.

关键词： n-l-Syzygy modules n-w-torsionfree modules approximation presentations grade

Synthesis of high grade octahedron diamond through epitaxial growth

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中国有色金属学会会刊：英文版 1999年第3期9卷 477-480页

作者： Yi Jianhong(易建宏) National Key Laboratory for Powder Metallurgy, Central South University of Technology, Changsha 410083, P.R. China Cent S Univ Technol Natl Key Lab Powder Met Changsha 410083 Peoples R China

The work was based on the relationship between the crystal structure and parameters of diamonds in the synthetic process, in which Ni Mn C powder catalyst was used. At first, the diamond crystals nucleated in a cubic octahedron morphology through controlling such synthetic parameters as temperature and pressure in a parameter region where cubic octahedron ctystals can be obtained. Then the diamond nuclei grew epitaxially into crystals with a perfect octahedron morphology through increasing the synthesis temperature and decreasing the synthesis pressure in a parameter region where octahedron crystals can be obtained.

关键词： high grade diamond eqitaxial growth

Intravoxel incoherent motion diffusion-weighted magnetic resonance imaging for predicting histological grade of hepatocellular carcinoma:Comparison with conventional diffusion-weighted imaging

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World Journal of Gastroenterology 2018年第8期24卷 929-940页

作者： Shao-Cheng Zhu Yue-Hua Liu Yi Wei Lin-Lin Li She-Wei Dou Ting-Yi Sun Da-Peng Shi Department of Radiology Henan Provincial People’s HospitalZhengzhou 450003Henan ProvinceChina Medical College of Henan University Kaifeng 475000Henan ProvinceChina Department of Radiology West China HospitalSichuan UniversityChengdu 610000Sichuan ProvinceChina Department of Pathology Henan Provincial People’s HospitalZhengzhou 450003Henan ProvinceChina

AIM To compare intravoxel incoherent motion(IVIM)-derived parameters with conventional diffusion-weighted imaging(DWI) parameters in predicting the histological grade of hepatocellular carcinoma(h CC) and to evaluate the correlation between the parameters and the histological *** A retrospective study was performed. Sixty-two patients with surgically confirmed h CCs underwent diffusion-weighted magnetic resonance imaging with twelve b values(10-1200 s/mm^2). The apparent diffusion coefficient(ADC), pure diffusion coefficient(D), pseudo-diffusion coefficient(D*), and perfusion fraction(f) were calculated by two radiologists. The IVIM and conventional DWI parameters were compared among the different grades by using analysis of variance(ANOVA) and the Kruskal-Wallis test. Receiver operating characteristic(ROC) analysis was performed to evaluate the diagnostic efficiency of distinguishing between low-grade(grade 1, G1) and high-grade(grades 2 and 3, G2 and G3) hC C. The correlation between the parameters and the histological grades was assessed by using the Spearman correlation test. Bland-Altman analysis was used to evaluate the reproducibility of the two radiologists' *** The differences in the ADC and D values among the groups with G1, G2, and G3 histological grades of HCCs were statistically significant(P grades of h CC(P > 0.05). The ROC analyses demonstrated that the D and ADC values had better diagnostic performance in differentiating the low-grade h CC from the high-grade h CC, with areas under the curve(AUCs) of 0.909 and 0.843, respectively, measured by radiologist 1 and of 0.911 and 0.852, respectively, measured by radiologist 2. The following significant correlations were obtained between the ADC, D, and D~* values and the histological grades: r =-0.619(P < 0.001), r =-0.628(P < 0.001), and r =-0.299(P = 0.018), respectively, as measured

关键词： Intravoxel incoherent motion Diffusionweighted imaging hepatocellular carcinoma Pathological differentiation grade

Simulation on Remanufacturing Cost by Considering Quality grade of Returns and Buffer Capacity

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Journal of Shanghai Jiaotong university(Science) 2019年第4期24卷 471-476页

作者： ZHENG Yuqiao ZHANG Chengcheng SU Chun School of Mechanical and Electronic Engineering Lanzhou University of TechnologyLanzhou730050China School of Mechanical Engineering Southeast UniversityNanjing211189China

Selecting the remanufacturing system as object of the study, the buffer capacity is served as control variable, and design of experiment(DOE) and simulation are used to analyze the effect that uncertain quality of returns acts on system performance. The remanufacturing time and the recovery rate in each station are used to represent the quality level of the returns, and the variance of remanufacturing time is used to denote the variability of returns’ quality. Three factors(the variability, the proportion and the recovery rate) of different quality levels in returns are considered. By analyzing the variance and the range of the simulation results, some important conclusions are obtained: recovery rate affects the remanufacturing cost by far, and the variability has the minimum influence;furthermore, for the returns, the more obvious of the dispersion degree, the higher proportion of the high-level quality, and the higher of the recovery rate, the lower the cost of remanufacturing will be.

关键词： remanufacturing buffer simulation design of experiment(DOE) quality grade

New therapeutic perspectives in irritable bowel syndrome: Targeting low-grade inflammation, immuno-neuroendocrine axis, motility, secretion and beyond

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World Journal of Gastroenterology 2017年第36期23卷 6593-6627页

作者： Emanuele Sinagra Gaetano Cristian Morreale Ghazaleh Mohammadian Giorgio Fusco Valentina Guarnotta Giovanni Tomasello Francesco Cappello Francesca Rossi Georgios Amvrosiadis Dario Raimondo Gastroenterology and Endoscopy Unit Fondazione Istituto Giuseppe GiglioContrada Pietra Pollastra Pisciotto Euro-Mediterranean Institute of Science and Technology Department of Experimental Biomedicine and Clinical Neuroscience Section of Human AnatomyUniversity of Palermo Unit of Gastroenterology Ospedali Riuniti Villa Sofia-Vincenzo Cervello Department of Medicine Division of Gastroenterology and HepatologyKarolinska InstitutetKarolinska University Hospital Unit of Internal Medicine Ospedali Riuniti Villa Sofia-Vincenzo Cervello Section of Cardio-Respiratory and Endocrine-Metabolic Diseases Biomedical Department of Internal and Specialist MedicineUniversity of Palermo

Irritable bowel syndrome(IBS)is a chronic,recurring,and remitting functional disorder of the gastrointestinal tract characterized by abdominal pain,distention,and changes in bowel *** there are several drugs for IBS,effective and approved treatments for one or more of the symptoms for various IBS subtypes are *** understanding of pathophysiological mechanisms such as the role of impaired bile acid metabolism,neurohormonal regulation,immune dysfunction,the epithelial barrier and the secretory properties of the gut has led to advancements in the treatment of *** regards to therapies for restoring intestinal permeability,multiple studies with prebiotics and probiotics are ongoing,even if to date their efficacy has been *** parallel,much progress has been made in targeting low-grade inflammation,especially through the introduction of drugs such as mesalazine and rifaximin,even if a better knowledge of the mechanisms underlying the low-grade inflammation in IBS may allow the design of clinical trials that test the efficacy and safety of such *** literature review aims to summarize the findings related to new and investigational therapeutic agents for IBS,most recently developed in preclinical as well as Phase 1 and Phase 2clinical studies.

关键词： Therapy Low grade inflammation Motility Secretion Irritable bowel syndrome Immunoendocrine axis