检索结果-南通市图书馆

Structural Integrity Assessment of Offshore Jackets Considering Proper Modeling of Buckling in Tubular Members-a Case Study of Resalat Jacket

引用

Journal of Marine Science and Application 2022年第4期21卷 145-167页

作者： mohammad hadi Erfani Department of Mechanical Engineering Sharif University of TechnologyTehran ***Iran

In the present research,results of buckling analysis of 384 finite element models,verified using three different test results obtained from three separate experimental investigations,were used to study the effects of five parameters such as D/t,L/D,imperfection,mesh size and mesh size ***,proposed equations by offshore structural standards concerning global and local buckling capacity of tubular members including former API RP 2A WSD and recent API RP 2A LRFD,ISO 19902,and NORSOK N-004 have been compared to FE and experimental *** of the most crucial parts in the estimation of the capacity curve of offshore jacket structures is the correct modeling of compressive members to properly investigate the interaction of global and local buckling which leads to the correct estimation of performance levels and *** of the proper compressive behavior of tubular members validated by experimental data is the main purpose of this *** of compressive braces of offshore jacket platforms by 3D shell or solid elements can consider buckling modes and deformations due to local *** FE software is selected for FE *** scope of action of each of elastic buckling,plastic buckling,and compressive yielding for various L/r ratios is ***,the most affected part of each parameter on the buckling capacity curve is *** pushover results of the Resalat Jacket with proper versus improper modeling of compressive members have been compared as a case *** to the results,applying improper mesh size for compressive members can under-predict the ductility by 33%and under-estimate the lateral loading capacity by up to 8%.Regarding elastic stiffness and post-buckling strength,the mesh size ratio is introduced as the most effective ***,imperfection is significantly the most important parameter in terms of critical buckling load.

关键词： Critical buckling load Compressive behavior Post-buckling strength Local buckling Tubular members Jacket type offshore platforms

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A robust intelligent audio watermarking scheme using support vector machine

引用

Frontiers of Information Technology & Electronic Engineering 2016年第12期17卷 1320-1330页

作者： mohammad MOSLEH hadi LATIFPOUR mohammad KHEYRANDISH Mahdi MOSLEH Najmeh HOSSEINPOUR Department of Computer Engineering Dezfoul Branch Islamic Azad University Dezfoul Iran Department of Computer Engineering Andimeshk Branch Islamic Azad University Andimeshk Iran Young Researchers and Elite Club Andimeshk Branch Islamic Azad University Andimeshk Iran

Rapid growth in information technology and computer networks has resulted in the universal use of data transmission in the digital domain. However, the major challenge faced by digital data owners is protection of data against unauthorized copying and distribution. Digital watermark technology is starting to be considered a credible protection method to mitigate the potential challenges that undermine the efficiency of the system. Digital audio watermarking should retain the quality of the host signal in a way that remains inaudible to the human hearing system. It should be sufficiently robust to be resistant against potential attacks, One of the major deficiencies of conventional audio watermarking techniques is the use of non-intelligent decoders in which some sets of specific rules are used for watermark extraction. This paper presents a new robust intelligent audio water- marking scheme using a synergistic combination of singular value decomposition （SVD） and support vector machine （SVM）. The methodology involves embedding a watermark data by modulating the singular values in the SVD transform domain. In the extraction process, an intelligent detector using SVM is suggested for extracting the watermark data. By learning the destructive effects of noise, the detector in question can effectively retrieve the watermark. Diverse experiments under various conditions have been carried out to verify the performance of the proposed scheme. Experimental results showed better imperceptibility, higher robustness, lower payload, and higher operational efficiency, for the proposed method than for conventional techniques.

关键词： Audio watermarking Copyright protection Singular value decomposition (SVD) Machine learning Support vector machine (SVM)

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Investigation and evaluation of ultrasound reactor for reduction of fungi from sewage

引用

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2007年第7期8卷 493-497页

作者： DEHGHANI mohammad hadi MAHVI Amir Hossein JAHED Gholam Reza SHEIKHI Razieh Department of Environmental Health Engineering School of Public Health Medical Sciences/University of Tehran P.O. Box 14155-6145 Tehran I.R. Iran

The objective of the investigation was to study the application of ultrasound reactor technology (USRT) as a disin-fectant for reduction of fungi from sewage effluent. Fungi are carbon heterotrophs that require preformed organic compounds as carbon sources. USRT is an attractive means to improve water quality because of the system simplicity and no production of toxic by-products. An ultrasound reactor produces strong cavitation in aqueous solution causing shock waves and reactive free radicals by the violent collapse of the cavitation bubble. These effects should contribute to the physical disruption of microbial structures and inactivation of organisms. There was significant reduction in fungal growth, with decreased fungal growth with increasing USRT. In this study, ultrasound irradiation at a frequency of 42 kHz was used to expose suspensions of fungi to evaluate the disinfection efficacy of the ultrasound reactor. Also, this study showed that in this system more than 99% reduction of sewage fungi was achieved after 60 min.

关键词： Ultrasound reactor Sewage Fungi Cavitation Frequency

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Application of response surface methodology and central composite rotatable design for modeling the influence of some operating variables of the lab scale thickener performance

引用

International Journal of Mining Science and Technology 2013年第5期23卷 717-724页

作者： Aghajani Shahrivar Alireza Soltani Goharrizi Ataallah Ebrahimzadeh Gheshlaghi Majid Sarafi Amir Razmirad mohammad Abdollahi hadi Department of Chemical Engineering University of Shahid Bahonar School of Mining Engineering College of EngineeringUniversity of Tehran

This study discussed the application of response surface methodology(RSM)and central composite rotatable design(CCRD)for modeling and optimization of the influence of some operating variables on the performance of a lab scale thickener for dewatering of tailing in the flotation *** thickener operating variables,namely feed flowrate,solid percent,flocculant dosage and feedwell height were changed during the tests based on *** ranges of values of the thickener variables used in the design were a feed flowrate of 9–21 L/min,solid percent of 8%–20%,flocculant dosage of 1.25–4.25 g/t and feedwell height of 16–26 cm.A total of 30 thickening tests were conducted using lab scale thickener on flotation tailing obtained from the Sarcheshmeh copper mine,*** underflow solid percent and bed height were expressed as functions of four operating parameters of *** values were found to be in good agreement with experimental values(R2values of 0.992 and 0.997 for underflow solid percent and bed height,respectively).This study has shown that the RSM and CCRD could effciently be applied for the modeling of thickener for dewatering of flotation tailing.

关键词： Response surface methodology Central composite rotatable design Modeling Thickener

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Dispersion compensation using high-positive dispersive optical fibers

引用

Chinese Optics Letters 2017年第3期15卷 64-68页

作者： Mohammand hadi Farokh Marvasti mohammad Reza Pakravan Electrical Engineering Department Sharif University of Technology Tehran 113658639 Iran

The common and traditional method for optical dispersion compensation is concatenating the transmitting optical fiber by a compensating optical fiber having a high-negative dispersion coefficient. In this Letter, we take the opposite direction and show how an optical fiber with a high-positive dispersion coefficient is used for dispersion compensation. Our optical dispersion compensating structure is the optical implementation of an iterative algorithm in signal processing. The proposed dispersion compensating system is constructed by cascading a number of compensating sub-systems, and its compensation capability is improved by increasing the number of embedded sub-systems. We also show that the compensation capability is a trade-off between the transmission length and bandwidth. We use the simulation results to validate the performance of the introduced dispersion compensating module. Photonic crystal fibers with high-positive dispersion coefficients can be used for constructing the proposed optical dispersion compensating module.

关键词： Dispersion compensation using high-positive dispersive optical fibers high

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Simultaneous determination of cysteamine and folic acid in pharmaceutical and biological samples using modified multiwall carbon nanotube paste electrode

引用

Chinese Chemical Letters 2012年第2期23卷 237-240页

作者： Ali Taherkhani Hassan Karimi-Maleh Ali A.Ensafi hadi Beitollahi Ahmad Hosseini mohammad A.Khalilzadeh Hassan Bagheri Department of Physics Takestan Branchlslamic Azad UniversityTakestanlran Department of Chemistry Majlesi BranchIslamic Azad UniversityIsfahanIran Environment Department Research Institute of Environmental SciencesInternational Center for ScienceHigh Technology and Environmental SciencesKermanIran Department of Chemistry Qaemshahr BranchIslamic Azad UniversityQaemshahrlran Department of Chemistry Takestan Branchlslamic Azad UniversityTakestanlran

A carbon paste electrode（CPE） chemically modified with multiwall carbon nanotubes and ferrocene（FC） was used as a selective electrochemical sensor for the simultaneous determination of trace amounts of cysteamine（CA） and folic acid（FA）.This modified electrode showed very efficient electrocatalytic activity for the anodic oxidation of *** peak current of differential pulse voltammograms of CA and FA increased linearly with their concentration in the ranges of 0.7-200μmol/L CA and 5.0- 700μmol/L *** detection limits for CA and FA were 0.3μmol/L and 2.0μmoI/L,*** diffusion coefficient（D） and transfer coefficient（α） of CA were also *** conditions are sufficient to allow determination of CA and FA both individually and simultaneously.

关键词： Cysteamine Folic acid Carbon nanotube paste electrode Voltammetry

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Modeling and optimization of low-grade Mn bearing ore leaching using response surface methodology and central composite rotatable design

引用

Transactions of Nonferrous Metals Society of China 2012年第9期22卷 2295-2305页

作者： Dariush AZIZI Sied Ziaedin SHAFAEI mohammad NOAPARAST hadi ABDOLLAHI School of Mining University College of EngineeringUniversity of TehranTehranIran

The application of leaching process to extracting Mn from a low-grade manganese ore was investigated using a software based design of experiments. Four main parameters, i.e. sulfuric acid concentration, oxalic acid concentration, time and temperature were considered in a central composite response surface design. The recoveries of Mn and Fe were selected as response of design. The optimum conditions under which the Mn and Fe recoveries were the highest and the time and temperature were the lowest were determined using statistical analysis and analysis of variance （ANOVA）. The results showed that Mn and Fe recoveries were 93.44% and 15.72% under the optimum condition, respectively. Also, sulfuric acid concentration was the most effective parameter affecting the process. The amounts of sulfuric and oxalic acid were obtained to be 7% and 42.50 g/L in optimum condition and the best time and temperature were 65 min and 63 ℃.

关键词： response surface methodology leaching manganese optimization modeling

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Optimal design and applicability of electric power steering system for automotive platform

引用

Journal of Central South University 2019年第4期26卷 839-851页

作者： Abolfazl KHALKHALI mohammad Hassan SHOJAEEFARD Masoud DAHMARDEH hadi SOTOUDEH Automotive Simulation and Optimal Design Research Laboratory School of Automotive EngineeringIran University of Science and Technology

The ongoing need for better fuel economy and lower exhaust pollution of vehicles has increased the employment of electric power steering(EPS)in *** design of EPS for a product family reduces the development and fabrication costs *** this paper,the TOPSIS method along with the NSGA-Ⅱis employed to find an optimum family of EPS for an automotive platform.A multi-objective optimization problem is defined considering road feel,steering portability,RMS of Ackerman error,and product family penalty function(PFPF)as the conflicting objective *** results for the single objective optimization problems and the ones for the multi-objective optimization problem,as well as two suggested trade-off design points are presented,compared and *** the two suggested points,performance at one objective function is deteriorated by about 1%,while the commonality is increased by 20%–40%,which shows the effectiveness of the proposed method in first finding the non-dominated design points and then selecting the trade-off among the obtained *** results indicate that the obtained trade-off points have superior performance within the product family with maximum number of common parts.

关键词： product family optimization optimal platform design NSGA-Ⅱ TOPSIS electric power steering

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Optimal Control Strategy for a Fully Determined HIV Model

引用

Intelligent Control and Automation 2010年第1期1卷 15-19页

作者： mohammad Shirazian mohammad hadi Farahi 不详

This paper shows how mathematical methods can be implemented to formulate guidelines for clinical testing and monitoring of HIV/AIDS disease. First, a mathematical model for HIV infection is presented which the measurement of the CD4+T cells and the viral load counts are needed to estimate all its parameters. Next, through an analysis of model properties, the minimal number of measurement samples is obtained. In the sequel, the effect of Reverse Transcriptase enzyme Inhibitor (RTI) on HIV progression is demonstrated by using a control function. Also the total cost of treatment by this kind of drugs has been minimized. The numerical results are obtained by a numerical method in discretization issue, called AVK.

关键词： HIV/AIDS Mathematical Modeling System Identification Control Theory Immunotherapy

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Structural and biological engineering of 3D hydrogels for wound healing

引用

生物活性材料(英文) 2023年第6期24卷 197-235页

作者： mohammad hadi Norahan Sara Cristina Pedroza-González Mónica Gabriela Sánchez-Salazar Mario Moisés Álvarez Grissel Trujillo de Santiago Escuela de Ingeniería y Ciencias Tecnológico de MonterreyMonterreyNL64849Mexico Centro de Biotecnología-FEMSA Tecnológico de MonterreyMonterreyNuevo LeónCP64849Mexico Departamento de Bioingeniería Tecnológico de MonterreyMonterreyNuevo LeónCP64849Mexico

Chronic wounds have become one of the most important issues for healthcare systems and are a leading cause of death *** dressings are necessary to facilitate wound *** wound dressings may substantially reduce healing time,reduce the risk of recurrent infections,and reduce the disability and costs *** the path of engineering of an ideal wound dressing,hydrogels have played a leading *** are 3D hydrophilic polymeric structures that can provide a protective barrier,mimic the native extracellular matrix(ECM),and provide a humid *** to their advantages,hydrogels(with different architectural,physical,mechanical,and biological properties)have been extensively explored as wound dressing *** we describe recent studies on hydrogels for wound healing applications with a strong focus on the interplay between the fabrication method used and the architectural,mechanical,and biological performance ***,we review different categories of additives which can enhance wound regeneration using 3D hydrogel *** engineering for wound healing applications promises the generation of smart solutions to solve this pressing problem,enabling key functionalities such as bacterial growth inhibition,enhanced re-epithelialization,vascularization,improved recovery of the tissue functionality,and overall,accelerated and effective wound healing.

关键词： Wound healing Wound dressing Hydrogel Tissue engineering 3D culture

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：