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Explaining surface interactions for common associated gangues of rare earth minerals in response to the oxalic acid

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International Journal of Mining Science and Technology 2018年第2期28卷 343-346页

作者： saeed Chehreh Chelgani Brian Hart Department of Electrical Engineering and Computer Science University of Michigan Surface Science Western University of Western Ontario

In the flotation of rare earth minerals(REMs), oxalic acid is reportedly acting both as a depressant and p H modifier. Although results of testing have established the significance of oxalic acid in the flotation process, its specific role in either the recovery or selectivity of REMs over their common gangue minerals is not well understood. Pulp p H reduction trials with alternative acids have not shown the same effect on the REMs recovery or the depression of gangue phases. This work studies the effect of oxalic acid on the surface of common REMs gangue minerals(quartz and carbonates(dolomite and calcite)) in a series of conditioning tests. Gangue surface analyses by time of flight secondary ion mass spectroscopy(TOFSIMS) indicate that oxalic acid inhibits the transfer of secondary ions generated during the conditioning process from one mineral to another. In this regard, the oxalate anion acts to fix ions in solution through chelation, limiting their participation in surface adsorption.

关键词： Oxalic acid Rare earth Silicate Carbonate TOF-SIMS

Distinct colonoscopy findings of microscopic colitis:Not so microscopic after all?

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World Journal of Gastroenterology 2011年第37期17卷 4157-4165页

作者： Anastasios Koulaouzidis Athar A saeed Endoscopy Unit Centre for Liver and Digestive DisordersThe Royal Infirmary of Edinburgh Gastroenterology Department Queen Elizabeth Hospital

Microscopic colitis(MC) is considered an "umbrella term",comprising two subtypes,i.e.,collagenous colitis(CC) and lymphocytic colitis(LC).They are classically associated with normal or unremarkable *** the last few years,reports have been published revealing findings that are thought to be characteristic or pathognomonic of MC,especially CC.A systematic electronic and manual search of PubMed and EMBASE(to December 2010),for publications on distinct endoscopic findings in MC,resulted in 42 relevant reports for inclusion in this *** eight patients with collagenous colitis were *** one publication describing a distinct endoscopic pattern in LC was *** findings in CC are alteration of the vascular mucosal pattern,mucosal nodularity,a sequence of change from mucosal defects to mucosal cicatricial lesions,and perhaps(although of doubtful relevance) mucosal pseudomembranes.A causal connection of mucosal defects with the use of lansoprazole seems to *** of the proposed lesion description herein is recommended in order to improve homogeneity of future reports.

关键词： Collagenous colitis Microscopic colitis Endoscopy Mucosa Lesion

An autoregressive integrated moving average model for short-term prediction of hepatitis C virus seropositivity among male volunteer blood donors in Karachi,Pakistan

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World Journal of Gastroenterology 2009年第13期15卷 1607-1612页

作者： saeed Akhtar Shafquat Rozi Department of Community Medicine and Behavioral Sciences Faculty of MedicineKuwait University Department of Community Health Sciences Medical CollegeAga Khan University

AIM： To identify the stochastic autoregressive integrated moving average （ARIMA） model for short term forecasting of hepatitis C virus （HCV） seropositivity among volunteer blood donors in Karachi, Pakistan.METHODS： Ninety-six months （1998-2005） data on HCV seropositive cases （1000-1 x month1） among male volunteer blood donors tested at four major blood banks in Karachi, Pakistan were subjected to ARIMA modeling. Subsequently, a fitted ARIMA model was used to forecast HCV seropositive donors for 91-96 mo to contrast with observed series of the same months. To assess the forecast accuracy, the mean absolute error rate （%） between the observed and predicted HCV seroprevalence was calculated. Finally, a fitted ARIMA model was used for short-term forecasts beyond the observed series.RESULTS： The goodness-of-fit test of the optimum ARIMA （2,1,7） model showed non-significant autocorrelations in the residuals of the model. The forecasts by ARIMA for 91-96 mo closely followed the pattern of observed series for the same months, with mean monthly absolute forecast errors （%） over 6 mo of 6.5%. The short-term forecasts beyond the observed series adequately captured the pattern in the data and showed increasing tendency of HCV seropositivity with a mean ± SD HCV seroprevalence （1000^-1× month^-1） of 24.3 ±1.4 over the forecast interval.CONCLUSION： To curtail HCV spread, public health authorities need to educate communities and health care providers about HCV transmission routes based on known HCV epidemiology in Pakistan and its neighboring countries. Future research may focus on factors associated with hyperendemic levels of HCV infection.

关键词： Hepatitis C virus Blood donor Ecologicalanalysis Autoregressive integrated moving averagemodel Pakistan

Generation of structure light in probe absorption spectrum via microwave-driven Y-type atomic system

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Chinese Physics B 2023年第12期32卷 367-371页

作者： Muhammad saeed Muqaddar Abbas Center for Integrated Quantum Information Technologies(IOIT) School of Physics and Astronomyand State Key Laboratory of Advanced Optical Communication Systems and NetworksShanghai Jiao Tong UniversityShanghai 200240China Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter(Ministry of Education) Shaanxi Province Key Laboratory of Quantum Information and Quantum Optoelectronic DevicesSchool of PhysicsXi'an Jiaotong UniversityXi'an 710049China

Behavior of structure light is investigated by monitoring probe absorption using a microwave-driven Y-type atomic media *** system under consideration is driven by one of the control vortex beams as well as an extra non-vortex control beam to ensure electromagnetically induced *** significant aspect in the generation of structured light is the azimuthal phase-dependent modification for probe *** intensity distribution for absorption spectra is examined for simultaneously evaluating both the control vortex *** also go through the radial distribution of intensity for various orbital angular momentum *** modes of structural beams may be distinguished using the suggested *** research gives us a way for rapidly transferring vortex wavefronts from control field to probe absorption *** could be useful in quantum information processing.

关键词： structure light vortex beam

A New Insight into Energy Distribution of Electrons in Fuel-Rod Gap in VVER-1000 Nuclear Reactor

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Plasma Science and Technology 2015年第6期17卷 441-447页

作者： Fereshteh GOLIAN Ali PAZIRANDEH saeed MOHAMMADI Payam Noor University Science & Research Branch Islamic Azad University

In order to calculate the electron energy distribution in the fuel rod gap of a VVER- 1000 nuclear reactor, the Fokker-Planck equation （FPE） governing the non-equilibrium behavior of electrons passing through the fuel-rod gap as an absorber has been solved in this paper. Besides, the Monte Carlo Geant4 code was employed to simulate the electron migration in the fuel-rod gap and the energy distribution of electrons was found. As for the results, the accuracy of the FPE was compared to the Geant4 code outcomes and a satisfactory agreement was found. Also, different percentage of the volatile and noble gas fission fragments produced in fission reactions in fuel rod, i.e. Krypton, Xenon, Iodine, Bromine, Rubidium and Cesium were employed so as to investigate their effects on the electrons＇ energy distribution. The present results show that most of the electrons in the fuel rod＇s gap were within the thermal energy limitation and the tail of the electron energy distribution was far from a Maxwellian distribution. The interesting outcome was that the electron energy distribution is slightly increased due to the accumulation of fission fragments in the gap. It should be noted that solving the FPE for the energy straggling electrons that are penetrating into the fuel-rod gap in the VVER-1000 nuclear reactor has been carried out for the first time using an analytical approach.

关键词： plasma electron energy distribution function Langevin approach based onFokker-Planck equation Geant4 Monte Carlo code

Optimal design of structures for earthquake loads by a hybrid RBF-BPSO method

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Earthquake Engineering and Engineering Vibration 2008年第1期7卷 13-24页

作者： Eysa Salajegheh saeed Gholizadeh Mohsen Khatibinia Department of Civil Engineering University of Kerman Kerman lran

The optimal seismic design of structures requires that time history analyses （THA） be carried out repeatedly. This makes the optimal design process inefficient, in particular, if an evolutionary algorithm is used. To reduce the overall time required for structural optimization, two artificial intelligence strategies are employed. In the first strategy, radial basis function （RBF） neural networks are used to predict the time history responses of structures in the optimization flow. In the second strategy, a binary particle swarm optimization （BPSO） is used to find the optimum design. Combining the RBF and BPSO, a hybrid RBF-BPSO optimization method is proposed in this paper, which achieves fast optimization with high computational performance. Two examples are presented and compared to determine the optimal weight of structures under earthquake loadings using both exact and approximate analyses. The numerical results demonstrate the computational advantages and effectiveness of the proposed hybrid RBF-BPSO optimization method for the seismic design of structures.

关键词： earthquake optimization binary particle swarm neural networks radial basis function

On intervals and sets of hypermatrices(tensors)

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Frontiers of Mathematics in China 2020年第6期15卷 1175-1188页

作者： saeed RAHMATI Mohamed A.TAWHID Department of Mathematics and Statistics Faculty of ScienceThompson Rivers UniversityKamloopsBC V2C 0C8Canada

Interval hypermatrices(tensors)ape introduced and interval α-hypermatrices are uniformly characterized using a finite set of'extreme'hypermatrices,where α can be strong P,semi-positive,or positive definite,among many *** is shown that a symmetric interval is an interval(strictly)copositive-hypermatrix if and only if it is an interval(E)*** is also shown that an even-order,symmetric interval is an interval positive(semi-)definite-hypermatrix if and only if it is an interval P(P_(0))-*** hypermnatrices are generalized to sets of hyper-matrices,several slice-properties of a set of hypermatrices are introduced and sets of hypermatrices with various slice-properties are uniformly *** a consequence,several slice-properties of a compact,convex set of hyper-matrices are characterized by its extreme points.

关键词： Tensor hypermatrix interval hypermatrix hypermatrix set slice-P-property

Intracavity configuration for tuning and obtaining simultaneous dual-wavelength operation from CW Nd:YAG laser

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Chinese Optics Letters 2011年第7期9卷 55-58页

作者： Alireza Khorsandi saeed Ghavami Sabouri Department of Physics Isfahan University

In this letter, a thin slab of glass is used as Fabry-Perot etalon inside a cavity of a continuous wave （CW） Nd：YAG laser to change the behavior of its output longitudinal modes. The slab etalon is used as tuning element when it turns around the laser cavity axis. Two simultaneous longitudinal modes with a relatively wide tuning range from 5.83 MHz to 0,02 THz are obtained when the Nd：YAG laser is operated at moderate output power of about 120 roW. The mode structure of this configuration is modeled and simulated. Computer-generated diagrams are also presented schematically and compared with the experimental results.

关键词： YAG Intracavity configuration for tuning and obtaining simultaneous dual-wavelength operation from CW Nd Nd CW

Energy Management of Networked Smart Railway Stations Considering Regenerative Braking, Energy Storage System, and Photovoltaic Units

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Energy Engineering 2023年第1期120卷 69-86页

作者： saeed Akbari Seyed saeed Fazel Hamed Hashemi-Dezaki School of Railway Engineering Iran University of Science and TechnologyTehran13114-16846Iran Department of Electrical and Computer Engineering University of KashanKashan***Iran Research and Innovational Center for Electrical Engineering(RICE) Faculty of Electrical EngineeringUniversity ofWest Bohemia(UWB)Pilsen30100Czech Republic

The networking of microgrids has received significant attention in the form of a smart *** this paper,a set of smart railway stations,which is assumed as microgrids,is connected *** has been tried to manage the energy exchanged between the networked microgrids to reduce received energy from the utility ***,the operational costs of stations under various conditions decrease by applying the proposed *** smart railway stations are studied in the presence of photovoltaic(PV)units,energy storage systems(ESSs),and regenerative braking *** regenerative braking is one of the essential ***,the stochastic behaviors of the ESS’s initial state of energy and the uncertainty of PV power generation are taken into account through a scenario-based *** networked microgrid scheme of railway stations(based on coordinated operation and scheduling)and independent operation of railway stations are *** proposed method is applied to realistic case studies,including three stations of Line 3 of Tehran Urban and Suburban Railway Operation Company(TUSROC).The rolling stock is simulated in the MATLAB ***,the coordinated operation of networked microgrids and independent operation of railway stations are optimized in the GAMS environment utilizing mixed-integer linear programming(MILP).

关键词： Energy management system(EMS) smart railway stations coordinated operation photovoltaic generation regenerative braking uncertainty scenario-based model mixed-integer linear programming(MILP)