检索结果-南通市图书馆

International Journal of Digital Earth 2012年第2期5卷 91-105页

作者： amir saeed homainejad Independent Research Group on Geospatial TehranIran

The effect of Digital Earth on our life is *** and updating Geospatial data in Digital Earth is also *** paper presents the application of a new approach of image registration in Digital *** approach was developed based on registering a mono photograph on a master 3D *** result is a 3D vector model,which can be broadly applied in visualisation,mapping,geographic information system(GIS),planning,change detection,as well as Digital *** approach does not require parameters of correction for *** accuracy of the output depends on the accuracy of the master *** approach is very versatile and able to register any image on the digital elevation model,digital surface model and topographic 3D model.

关键词： Digital Earth image registration 3D model

A Hybrid and Lightweight Device-to-Server Authentication Technique for the Internet of Things

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第3期78卷 3805-3823页

作者： Shaha Al-Otaibi Rahim Khan Hashim Ali Aftab Ahmed Khan amir saeed Jehad Ali Department of Information Systems College of Computer and Information SciencesPrincess Nourah bint Abdulrahman UniversityP.O.Box 84428Riyadh11671Saudi Arabia Department of Computer Science Abdul Wali Khan University MardanMardan23200Pakistan Department of Computer Science and IT UET PeshawarJalozai Campus PeshawarPeshawar24240Pakistan Department of AI Convergence Network Ajou UniversitySuwon16499South Korea

The Internet of Things(IoT)is a smart networking infrastructure of physical devices,i.e.,things,that are embedded with sensors,actuators,software,and other technologies,to connect and share data with the respective server *** IoTs are cornerstones in different application domains,the device’s authenticity,i.e.,of server(s)and ordinary devices,is the most crucial issue and must be resolved on a priority ***,various field-proven methodologies were presented to streamline the verification process of the communicating devices;however,location-aware authentication has not been reported as per our knowledge,which is a crucial metric,especially in scenarios where devices are *** paper presents a lightweight and location-aware device-to-server authentication technique where the device’s membership with the nearest server is subjected to its location information along with other ***,Media Access Control(MAC)address and Advance Encryption Scheme(AES)along with a secret shared key,i.e.,λ_(i) of 128 bits,have been utilized by Trusted Authority(TA)to generate MaskIDs,which are used instead of the original ID,for every device,i.e.,server and member,and are shared in the offline ***,TA shares a list of authentic devices,i.e.,server S_(j) and members C_(i),with every device in the IoT for the onward verification process,which is required to be executed before the initialization of the actual communication ***,every device should be located such that it lies within the coverage area of a server,and this location information is used in the authentication process.A thorough analytical analysis was carried out to check the susceptibility of the proposed and existing authentication approaches against well-known intruder attacks,i.e.,man-in-the-middle,masquerading,device,and server impersonations,etc.,especially in the IoT ***,proposed authentication and existing state-of-the-art approaches have been s

关键词： Internet of things authenticity security location communication

Coupling of RANS and BEM Solvers for Simulation of Propeller Behind the Hull in Full Appended Model

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Ocean Engineering 2024年第3期38卷 424-438页

作者： saeed NAJAFI Mehdi POURMOSTAFA LIU Peng-fei Iranian National Institute for Oceanography and Atmospheric Science(INIOAS) Tehran 14155-4781Iran Department of Maritime Engineering Amir Kabir University of TechnologyTehran 15875-4413Iran Marine Offshore and Subsea TechnologySchool of EngineeringNewcastle UniversityNewcastle upon TyneNE17RUUK

To design a propeller for ship power plant,the interaction between ship hull and propeller must be taken into *** main concern is to apply the wake effect of ship stern on the propeller *** this paper,a coupled BEM(Boundary Element Method)/RANS(Renolds-Averaged Navier−Stokes)solver is used to simulate propeller behind the hull in the self-propulsion *** motivation of this work is to develop a practical tool to design marine propulsion system without suffering long computational *** unsteady boundary element method which is also known as panel method is chosen to estimate the propeller *** wakes are treated using a time marching wake alignment ***,a RANS code coupled with VoF equation is developed to consider the ship motions and wake field effects in the problem.A coupling algorithm is developed to interchange ship wake field to the potential flow solver and propeller thrust to the RANS *** on the difference between hull resistance and the propeller thrust,a PI controller is developed to compute the propeller RPM in every time *** of the solver is carried out using the towing tank test report of a 50 m oceanography research *** factor and trust deduction coefficient are estimated ***,the wake rollup pattern of the propeller in open water is compared with the propeller in real wake field.

关键词： RANS BEM coupled method ship propeller self-propulsion wake sheet pattern

Shear behavior and dilatancy of an artificial hard-matrix bimrock: An experimental study focusing on the role of blocky structure

在线全文

学校读者我要写书评

暂无评论

Rock Mechanics Bulletin

Rock Mechanics Bulletin 2024年第4期3卷 83-101页

作者： amir Yazdani saeed Karimi-Nasab Hossein Jalalifar Department of Mining Engineering Isfahan University of TechnologyIsfahanIran Department of Mining Engineering Shahid Bahonar University of KermanKermanIran Department of Petroleum Engineering Shahid Bahonar University of KermanKermanIran

Bimrocks are characterized by their geotechnically significant blocky structure,presenting complex shear *** study investigates the shear behavior and dilatancy of bimrocks featuring a rock-like matrix,such as *** study addresses a gap in current research,which has predominantly examined the shear behavior of soil-matrix bimrocks(bimsoils).Laboratory direct shear tests were performed on idealized models with varying volumetric block proportions(VBPs).The results highlight that blocks exert both positive and negative effects on shear strength,dilation,and block breakage factor(BF),depending on *** indicate 40%and 60%as critical VBPs,revealing distinct shear strength trends within this range,contrary to the dominant downward *** positively impact dilation and BF between 20%and 50%VBP,while negatively affecting them beyond this *** skeleton inherently promotes stable dilatancy under normal stress increments and intensifies stress dependency of shear *** in dilation angle concerning normal stress and VBP suggest the potential for characterizing this factor using equivalent strength and roughness,akin to rockfill *** assessments of equivalent strength revealed positive effects of blocks when VBP was between 30%and 70%.Lastly,the findings indicate that blocks notably impact pre-and post-peak behaviors by reducing shear stiffness and inducing local hardening *** study also discusses the similarities and distinctions in the function of blocks within soil-like and rock-like *** offers new insights into the exact role of blocks in bimrock shear behavior beyond the traditional interpretation through the variation of friction and cohesion.

关键词： Bimrock Rock-like matrix Shear behavior Shear strength Shear dilation Block breakage

Isoimperatorin alleviates acetic acid-induced colitis in rats

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Biomedicine 2024年第4期14卷 147-153页

作者： Saied Goodarzi amir Hossein Abdolghaffari Behnaz Najafi Mostafa Pirali Hamedani saeed Tavakoli Mahshad Marvi Maryam Baeeri Narguess Yassa Abbas Hadjiakhoondi Mohammad Abdollahi Zahra Tofighi Medicinal Plants Research Center Faculty of PharmacyTehran University of Medical SciencesTehranIran Department of Toxicology and Pharmacology Faculty of PharmacyTehran Medical SciencesIslamic Azad UniversityTehranIran Department of Pharmacognosy Faculty of PharmacyTehran University of Medical SciencesTehranIran Medicinal Plants Research Center Institute of Medicinal PlantsACECRKarajIran International Campus School of Pharmacy Tehran University of Medical SciencesTehranIran Toxicology and Diseases group The Pharmaceutical Sciences Research CenterTehran University of Medical SciencesTehranIran Department of Toxicology and Pharmacology Faculty of PharmacyTehran University of Medical SciencesTehranIran

Objective:To investigate the effect of isoimperatorin on histopathological and biochemical changes in acetic acid-induced colitis ***:Colitis was induced by intracolonic administration of acetic acid solution(4%v/v)in *** were divided into six groups including the sham group,the negative control group,the dexamethasone-treated group,and the groups treated with isoimperatorin(0.1,1,and 10 mg/kg/d by gavage).The treatments were administered for three days and then colonic status was assessed by macroscopic,histopathological,and biochemical ***:Isoimperatorin significantly alleviated colonic damage in a dose-dependent manner and improved histological changes in rats with acetic acid-induced *** also significantly reduced myeloperoxidase,TNF-α,IL-1β,and malodialdehyde ***:Isoimperatorin alleviates acetic acid-induced colitis in rats and may be a potential therapeutic agent for the treatment of colitis.

关键词： Isoimperatorin Inflammatory bowel disease Acetic acid Colitis TNF-α IL-1β

Synthesis and characterization of new azo containing Schiff base macrocycle

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2011年第4期22卷 439-442页

作者： saeed Malek-Ahmadi amir Abdolmaleki Department of Chemistry Isfahan University of TechnologyIsfahan-84156/83111Iran

Fully conjugated Schiff base macrocycle has been prepared through a simple and mild condition,a one-pot cyclization procedure of four-component without using a *** condensation reaction of related bis（hydroxybenzaldehyde） with phenylenediamines to prepare a conjugated[2 ＋ 2]Schiff base macrocycle has been investigated and fluorescent[2 ＋ 2]Schiff base macrocycles with N_2O_2 binding pockets has been prepared and characterized by elemental analysis,^1H NMR,IR,fluorescent,UV-visible and MALDI mass spectroscopies.

关键词： Schiff base macrocycle Non-template Azo compounds

A critical state based thermo-elasto-plastic constitutive model for structured clays

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2017年第6期9卷 1094-1103页

作者： amir Hamidi saeed Tourchi Fatemeh Kardooni Department of Civil Engineering School of Engineering Kharazmi University Department of Civil and Environmental Engineering Universitat Politècnica de CatalunyaBarcelona Tech

In this paper, a critical state based thermo-elasto-plastic constitutive model is developed for destructured, naturally structured and artificially structured saturated clays. The model is an extension of the previously developed thermo-mechanical model by the authors for saturated clays, considering the effects of structure on the mechanical behaviors of the soil. It is based on change in the position of normal consolidation line(NCL) in a compression plane(e-ln p′) due to the soil’s structure and variation of temperature. The present model is able to simulate the mechanical behavior of structured saturated clays in a triaxial plane at elevated temperatures lower than the boiling point of water. An attempt has been made to use the lowest possible number of parameters compared with that of Came Clay model and to ensure that these new parameters have clear physical interpretations. The sufficiency of the model was verified by the test results on artificially and naturally structured soils using thermal triaxial tests.

关键词： Thermo-mechanical constitutive model Structured clays Cam Clay Normal consolidation line Boom Clay

Photocatalytic degradation of methylene blue by nanostructured Fe/FeS powder under visible light

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2018年第2期25卷 244-252页

作者： Hassan Esmaili amir Kotobi saeed Sheibani Fereshteh Rashchi School of Metallurgy and Materials Engineering College of Engineering University of Tehran

The photocatalytic performance of mechano-thermally synthesized Fe/FeS nanostructures formed from micron-sized starting materials was compared with that of a thermally synthesized nanostructure with nano-sized precursors in this paper. The properties of as-synthesized materials were studied by X-ray diffraction（XRD）, transmission electron microscopy（TEM）, vibrating sample magnetometry（VSM）, diffuse reflectance spectroscopy（DRS）, and ultraviolet–visible（UV-Vis） spectroscopy. The effects of irradiation time, methylene blue（MB） concentration, catalyst dosage, and p H value upon the degradation of MB were studied. Magnetic properties of the samples showed that both as-synthesized Fe/FeS photocatalysts are magnetically recoverable, eliminating the need for conventional filtration steps. Degradation of 5 ppm of the MB solution by mechano-thermally synthesized Fe/FeS with a photocatalyst dosage of 1 kg/m^3 at pH 11 can reach 96% after 12 ks irradiation under visible light. The photocatalytic efficiency is higher in alkaline solution. The kinetics of photocatalytic degradation in both samples is controlled by a first-order reaction. However, the rate-constant value in the thermally synthesized Fe/FeS photocatalyst sample is only 1.5 times greater than that of the mechano-thermally synthesized one.

关键词： photocatalytic degradation iron sulfide nanoparticles kinetics methylene blue visible light

On the higher-order thermal vibrations of FG saturated porous cylindrical micro-shells integrated with nanocomposite skins in viscoelastic medium

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2022年第8期18卷 1416-1434页

作者： Zeinab Soleimani-Javid Ehsan Arshid saeed amir Mahdi Bodaghi Department of Solid Mechanics Faculty of Mechanical EngineeringUniversity of KashanKashanIran Department of Engineering School of Science and TechnologyNottingham Trent UniversityNottinghamNG118NSUK

Since the multi-layered structures are widely used nowadays, and due to interesting applications of cylindrical shells, this study is dedicated to analyzing free vibrational behaviors of functionally graded saturated porous micro cylindrical shells with two nanocomposite skins. Based on Biot's assumptions, constitutive relations for the core are presented and effective properties of the skins are determined via the rule of mixture. A sinusoidal theory is used to capture the shear deformation effects, and to account for the scale effects, the modified couple stress theory is employed which suggests a material length-scale parameter for predicting the results in small-dimension. With the aid of extended form of Hamilton's principle for dynamic systems, differential equations of motion are extracted. Fourier series functions are used to obtain natural frequencies and after validating them, a set of parametric studies are carried out. The results show the significant effects of porosity and Skempton coefficient, pores placement patterns, CNTs addition and distribution patterns, temperature variations, material length-scale parameter and viscoelastic medium on the natural frequencies of the microstructure. The outcomes of this work could be used to design and manufacture more reliable micro cylindrical structures in thermo-dynamical environments.

关键词： Vibration analysis Cylindrical shells Saturate porous materials Nanocomposite materials Carbon nanotubes Sinusoidal shear deformation theory Viscoelastic medium

Thermo-mechanical constitutive modeling of unsaturated clays based on the critical state concepts

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2015年第2期7卷 193-198页

作者： saeed Tourchi amir Hamidi School of Engineering Kharazmi University

A thermo-mechanical constitutive model for unsaturated clays is constructed based on the existingmodel for saturated clays originally proposed by the authors. The saturated clays model was formulatedin the framework of critical state soil mechanics and modified Cam-clay model. The existing model hasbeen generalized to simulate the experimentally observed behavior of unsaturated clays by introducingBishop＇s stress and suction as independent stress parameters and modifying the hardening rule and yieldcriterion to take into account the role of suction. Also, according to previous studies, an increase intemperature causes a reduction in specific volume. A reduction in suction （wetting） for a given confiningstress may induce an irreversible volumetric compression （collapse）. Thus an increase in suction （drying）raises a specific volume i.e. the movement of normal consolidation line （NCL） to higher values of voidratio. However, some experimental data confirm the assumption that this reduction is dependent on thestress level of soil element. A generalized approach considering the effect of stress level on themagnitude of clays thermal dependency in compression plane is proposed in this study. The number ofmodeling parameters is kept to a minimum, and they all have clear physical interpretations, to facilitatethe usefulness of model for practical applications. A step-by-step procedure used for parameter calibrationis also described. The model is finally evaluated using a comprehensive set of experimental datafor the thermo-mechanical behavior of unsaturated soils.2015 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. All rights reserved.

关键词： Constitutive model Unsaturated clays Plasticity Cam-clay Critical state