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Does delayed gastric emptying shorten the H pylori eradication period? A double blind clinical trial

World Journal of Gastroenterology 2006年第39期12卷 6310-6315页

作者： mohammad Hassan Emami mohammad Mehdi Saberfiroozi Abbas Arj Ali reza Taghavi Kamran Bagheri-Lankarani Najaf Dehbashi mohammad reza fattahi Mahvash Alizadeh mohammad Javad Kaviani Rahim Bahri-Najafi Bita Geramizadeh Abbas Esmaeili Gastroenterologist Isfahan University of Medical Sciences Poursina Hakim Research Institute Isfahan Iran Gastroenterologist Namazi University Hospital School of Medicine Shiraz University of Medical Sciences Isfahan Iran Gastroenterologist School of Medicine Kashan University of Medical Sciences Isfahan Iran Clinical Pharmacist Pharmaceutical School Shiraz University of Medical Sciences Shiraz Iran General Practitioner Poursina Hakim Research Institute Isfahan Iran

AIM: To evaluate the gastric emptying inhibitory effects of sugar and levodopa on H pylori eradication period. METHODS: A total of 139 consecutive patients were randomized into 6 groups. The participants with peptic ulcer disease or non-ulcer dyspepsia non-responding to other medications who were also H pylori-positive patients either with positive rapid urease test (RUT) or positive histology were included. All groups were pretreated with omeprazole for 2 d and then treated with quadruple therapy regimen (omeprazole, bismuth, tetracycline and metronidazole); all drugs were given twice daily. Groups 1 and 2 were treated for 3 d, groups 3, 4 and 5 for 7 d, and group 6 for 14 d. Groups 1 to 4 received sugar in the form of 10% sucrose syrup. Levodopa was prescribed for groups 1 and 3. Patients in groups 2 and 4 were given placebo for levodopa and groups 5 and 6 received placebos for both sugar and levodopa. Upper endoscopy and biopsies were carried out before treatment and two months after treatment. Eradication of H pylori was assessed by RUT and histology 8 wk ***: Thirty patients were excluded. Per-protocol analysis showed successful eradication in 53% in group 1, 56% in group 2, 58% in group 3, 33.3% in group 4, 28% in group 5, and 53% in group 6. Eradication rate, patient compliance and satisfaction were not significantly different between the groups. CONCLUSION: It seems that adding sugar or levodopa or both to anti H pylori eradication regimens may lead to shorter duration of treatment.

关键词：胃排空幽门螺杆菌葡萄糖左旋多巴

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Modelling-based Optimisation of the Direct Synthesis of Dimethyl Ether from Syngas in a Commercial Slurry Reactor

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Chinese Journal of Chemical Engineering 2013年第6期21卷 611-621页

作者： Sadegh Papari mohammad Kazemeini Moslem fattahi Department of Chemical and Petroleum Engineering Sharif University of Technology Azadi Avenue 11365-9465Tehran Iran

在现在的学习，我们开发了一个多部件为为从 syngas 和 CO2 的 dimethyl 醚(DME ) 的直接合成的一个商业催化泥浆反应堆的模拟和优化的一个维的数学模型，在搅拌机狂暴的政体操作。DME 生产率和公司变换被调节操作条件优化，例如表面的... 详细信息

在现在的学习，我们开发了一个多部件为为从 syngas 和 CO2 的 dimethyl 醚(DME ) 的直接合成的一个商业催化泥浆反应堆的模拟和优化的一个维的数学模型，在搅拌机狂暴的政体操作。DME 生产率和公司变换被调节操作条件优化，例如表面的煤气的速度，催化剂集中，在臼齿的煤气的流动率(W/F ) 上的催化剂团， syngas 作文，压力和温度。反应堆建模被完成利用集体平衡，全球运动模型和异构的水动力学。在异构的流动政体，气体被散布进二个水泡阶段：小、大。模拟结果用从飞行员植物获得的数据被验证。发达模型为大规模泥浆反应堆的设计也是适用的。

关键词：浆态床反应器直接合成基于模型二甲醚合成气优化商业催化剂浓度

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Mathematical modeling of a slurry reactor for DME direct synthesis from syngas

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Journal of Natural Gas Chemistry 2012年第2期21卷 148-157页

作者： Sadegh Papari mohammad Kazemeini Moslem fattahi Department of Chemical and Petroleum Engineering Sharif University of Technology

In this paper,an axial dispersion mathematical model is developed to simulate a three-phase slurry bubble column reactor for direct synthesis of dimethyl ether（DME） from *** large-scale reactor is modeled using mass and energy balances,catalyst sedimentation andsingle-bubble as well as two-bubbles class flow hydrodynamics.A comparison between the two hydrodynamic models through pilot plantexperimental data from the literature shows that heterogeneous two-bubbles flow model is in better agreement with the experimental data thanhomogeneous single-bubble gas flow ***,by investigating the heterogeneous gas flow and axial dispersion model for small bubblesas well as the large bubbles and slurry（*** paraffins and the catalyst） phase,the temperature profile along the reactor is *** between isothermal and non-isothermal reactors reveals no obvious performance difference between *** optimum values ofreactor diameter and height were obtained at 7 m and 50 m,*** effects of operating variables on the axial catalyst distribution,DME productivity and CO conversion are also investigated in this research.

关键词： modeling large-scale slurry bubble column optimization dimethyl ether synthesis single-bubble class two-bubbles class isotherm andnon-isotherm

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Experimental investigation of density current patterns using dynamic fractal analysis

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International Journal of Sediment Research 2021年第2期36卷 165-176页

作者： mohammad Hosseini mohammad Hadi fattahi Saeid Eslamian Department of Civil Engineering Najafabad Branch Islamic Azad University Department of Civil Engineering Marvdasht Branch Islamic Azad University Department of Water Engineering Isfahan University of Technology

Density currents are caused by a difference in density, though low, of an entering fluid with the ambient fluid. This type of current is two-phased and found on riverbeds or in reservoirs behind dams, and is nonlinear in nature, complex, and sensitive to initial conditions. Fractal geometry is used as a powerful tool for studying complex natural phenomena. Using experimental studies and changes in inlet current conditions, the fractal and multi-fractal analyses of the interface between the density current and the ambient fluid were done. In addition, a search was made to find a possible connection between the nonlinear patterns. According to the results, with an increase in the inlet discharge and inlet density of the current the fractal dimension decreased. Further, the smaller the range of the singularity spectrum diagram was, i.e., the more it was less than 0.34, the lower the system’s tendency was to be multi-fractal,and the system sensitive to large local changes. In the interface between the density current and the ambient fluid, using the fractal dimension-based Richardson number could improve experimental data by 12.4%. Moreover, with an increase in the Richardson number, the Reynolds number of the current decreased. Further, upon considering the fractal dimension, the Reynolds number improved by 23% and a good correlation with a coefficient of determination of 0.76.

关键词： Density current Fractal geometry Richardson number Multi-fractal analysis Fluid interface

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A three dimensional CFD simulation and optimization of direct DME synthesis in a fixed bed reactor

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Petroleum Science 2014年第2期11卷 323-330页

作者： Fazel Moradi mohammad Kazemeini Moslem fattahi Department of Chemical and Petroleum Engineering Sharif University of Technology Department of Chemical Engineering Abadan Faculty of Petroleum Engineering Petroleum University of Technology

In this study, a comprehensive three-dimensional dynamic model was developed for simulating the flow behavior and catalytic coupling reactions for direct synthesis of dimethyl ether （DME） from syngas including CO2 in a fixed bed reactor at commercial scale under both adiabatic and isothermal conditions. For this purpose, a computational fluid dynamic （CFD） simulation was carried out through which the standard κ-ε model with 10% turbulence tolerations was implemented. At first, an adiabatic fixed bed reactor was simulated and the obtained results were compared with those of an equivalent commercial slurry reactor. Then the concentration and temperature profiles along the reactor were predicted. Consequently, the optimum temperature, pressure, hydrogen to carbon monoxide ratio in the feedstock and the reactor height under different operation conditions were determined. Finally, the results obtained from this three-dimensional dynamic model under appropriate industrial boundary conditions were compared with those of others available in literature to verify the model. Next, through changing the boundary conditions, the simulation was performed for an isothermal fixed bed reactor. Furthermore, it was revealed that, under isothermal conditions, the performed equilibrium simulations were done for a single phase system. Considering the simultaneous effects of temperature and pressure, the optimum operation conditions for the isothermal and adiabatic fixed bed reactors were investigated. The results of the H2＋CO conversions indicated that, under isothermal condition, higher conversion could be achieved, in compared with that under adiabatic conditions. Then, the effects of various operating parameters, including the pressure and temperature, of the reactor on the DME production were examined. Ultimately, the CFD modeling results generated in the present work showed reasonable agreement with previously obtained data available in the literature.

关键词： Modeling CFD dimethyl ether synthesis dynamic behavior fixed-bed reactor isothermaland adiabatic conditions

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Effect of water salinity on oil/brine interfacial behaviour during low salinity waterflooding: A mechanistic study

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Petroleum 2019年第4期5卷 367-374页

作者： Peyman Rostami mohammad fattahi Mehraban mohammad Sharifi Morteza Dejam Shahab Ayatollahi Department of Petroleum Engineering Amirkabir University of Technology(Polytechnic of Tehran)TehranIran Department of Petroleum Engineering College of Engineering and Applied ScienceUniversity of WyomingLaramieUSA Department of Chemical and Petroleum Engineering Sharif University of TechnologyTehranIran

In recent years,controlling the salinity and composition of the injected water has become an emerging enhanced oil recovery(EOR)technique,often described as low salinity(LS)*** work is done with the intention to contribute to the ongoing discussions about LS waterflooding mechanism(s).For this purpose,a series of different experiments were *** first,the effect of salinity on the interfacial tension(IFT)and the contact angle was evaluated with a crude oil *** to achieve more accurate results in observing oil/water interface,similar IFT experiments were also carried out on a synthetic oil containing ***,microscopic visualization using glass micromodel was performed on the interface of the synthetic oil sample and *** brine solutions including Sea Water(SW),it's dilutions and formation water(FW)were used for various ***,to investigate the presented mechanism by other authors,a series of Environmental Scanning Electron Microscopy(ESEM)analysis on the synthetic oil was carried out to understand better the phase behaviour after contacting both synthetic oil and water phases from the micromodel *** on the existing mechanism,there exists an optimal concentration beyond which dilution is no longer an effective process.

关键词： Water salinity Wettability Interfacial tension Oil/brine interface Low salinity waterflooding

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Retinal Identification System Based on the Combination of Fourier and Wavelet Transform

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Journal of Signal and Information Processing 2012年第1期3卷 35-38页

作者： Masoud Sabaghi S. reza Hadianamrei Mehdi fattahi mohammad reza Kouchaki Ali Zahedi Nuclear Science and Technology Research Institute Tehran Iran

Retinal image is one of the robust and accurate biometrics. A new biometric identification system base on combination of Fourier transform and that special partitioning and wavelet transform presented in this article. In this method, at first, optical disc is localized using template matching technique and use it for rotate the retinal image to reference position. Angular partitioning with the special structure on magnitude spectrum of retinal image and Wavelet Transform is used for feature definition. Finally we employ Euclidean distance for feature matching. The proposed method applied on a database consist 400 retinal images from 40 persons. In this article noisy and rotate retinal image are used in identification process. 99.1% identification rate can achieve in this proposed method.

关键词： Component Formatting Style Styling Insert

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An Empirical Study on Microbial Load and Acidity in Raw Milk Produced in Malayer and Nahavand Cities, Iran 2012

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Health 2014年第16期6卷 2184-2189页

作者： mohammad rezaei Ali Asghar Behzadi Ali Akbar Malekirad Ahmad fattahi Mohamad Hadi Farahzadi mohammad Sarmadi Hasan mohammadi Aghamirlou reza Ali Fallahzadeh Department of Food Safety and Hygiene School of Public Health Tehran University of Medical Sciences Tehran Iran Department of Food Safety and Hygiene School of Health Yazd University of Medical Sciences Yazd Iran Department of Biology Payame Noor University Tehran Iran Department of Occupational Health Engineering School of Health Shahid Sadoughi University of Medical Sci-ences Yazd Iran Department of Neuroscience School of Advanced Technologies in Medicine Tehran University of Medical Sciences Tehran Iran Department of Environmental Health and Engineering School of Public Health Tehran University of Medical Sciences Tehran Iran Department of Environmental Health Engineering School of Health Shahid Sadoughi University of Medical Sciences Yazd Iran

Milk is very susceptible for growth and development of many microorganisms because it is rich in nutrients and has suitable condition. Thus, it is very vital to respect sanitary conditions at all stages of production and transport of raw milk. The objective of the present investigation was to determine the total bacterial, and acidity in raw milk from milk collection centers in Malayer and Nahavand cities. 52 milk samples were collected from 13 centers in summer 2012 and were analyzed according to standard methods. None of the raw milk samples under investigation, had superior or grade 1 quality. Only 7.7% of the samples were classified as raw milk with grade 2 quality and 92.3% were non-standard. The mean of microbial total count in base was 3.8 × 107 CFU/ml and average acidity in the samples was 0.163. The city of Tochqhaz and Aliabade-Damagh has the lowest and the highest microbial total count. In general the result of this study showed unsatisfactory conditions of milk in the milk collection centers of the Malayer and Nahavand cities.

关键词： Food Safety Milk Collection Centers Acidity Microbial Total Counts

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Developing a Mathematical Model for Hydrate Formation in a Spray Batch Reactor

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Advances in Materials Physics and Chemistry 2012年第4期2卷 244-247页

作者： mohammad Kazemeini Farideh Freidoonian Moslem fattahi Department of Chemical and Petroleum Engineering Sharif University of Technology P.O. Box 11365-9465 Tehran Iran Department of Chemical and Petroleum Engineering Sharif University of Technology Tehran Iran Islamic Azad University South Tehran Branch Tehran Iran

The formation of methane hydrate was undertaken in this research. The purpose of this work was to model the methane hydrate formation with a hydrate-water–methane system in a semi-batch reactor under steady–state, isothermal and isobaric conditions. Obtained results were validated with experiments conducted in a semi-batch spray reactor at low temperatures and high pressures. The investigated formation of gas hydrate from pure methane required physical constants of these materials which were determined through experimental data. The experiments hence, the theoretical calculations were conducted with pure methane and carried out in a spray reactor at 273.95K and 8705kPa to determine the actual amount of hydrate formation in such reactor. Ultimately;the comparison of the results generated from the developed mathematical model with those of experimental data of others indicated a very satisfactory agreement obtained.

关键词： Hydrate Formation Methane Spray Reactor Semi-batch Modeling

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Retinal Identification System Based on the Combination of Fourier and Wavelet Transform

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Journal of Signal and Information Processing 2012年第1期

作者： Masoud Sabaghi S. reza Hadianamrei Mehdi fattahi mohammad reza Kouchaki Ali Zahedi

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