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Synthesis and Infrared Spectra Computation of Sterically Congested 2,2-Disubstituted Indane-1,3-dione Derivatives

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Chinese Journal of Structural Chemistry 2011年第4期30卷 568-574页

作者： Seyed mohammad Shoaei ali Reza Kazemizadeh ali Ramazani Department of Chemistry Islamic Azad UniversityZanjan Branch

Sterically congested 2,2-disubstituted indane-1,3-dione derivatives have been syn-thesized and characterized by 1H NMR,13C NMR,FT-IR and elemental *** B3LYP/HF calculations for computation of IR spectra have been carried out for the title compounds at the 6-31G and 6-311＋＋G basis set *** vibrational frequencies have been assigned and compared with the experimental FT-IR spectra and they are supported each other.

关键词： vibrational frequency DFT HF FT-IR spectra 2 2-disubstituted indane-1 3-dione isocyanide

Preparation and Characterization of DGEBA/EPN Epoxy Blends with Improved Fracture Toughness

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Chinese Journal of Polymer Science 2018年第5期36卷 632-640页

作者： Morteza Khalina mohammad Hosain Beheshty ali Salimi Department of Composites Iran Polymer and Petrochemical Institute Department of Resin and Adhesives Iran Polymer and Petrochemical Institute

The physical and mechanical properties of blends composed of two kinds of epoxy resins of different numbers of functional groups and chemical structure were studied. One of the resins was a bifunctional epoxy resin based on diglycidyl ether of bisphenol A and the other resin was a multifunctional epoxy novolac resin. Attempt was made to establish a correlation between the structure and the final properties of cured epoxy samples. The blend samples containing high fraction of multifunctional epoxy resin showed higher solvent resistance and lower flexural modulus compared with the blends containing high fraction of bifunctional epoxy resin. The epoxy blends showed significantly higher ductility under bending test than the neat epoxy samples. The compressive modulus and strength increased with increasing of multifunctional epoxy in the samples, probably due to enhanced cross-link density and molecular weight. Morphological analysis revealed the presence of inhomogeneous sub-micrometer structures in all samples. The epoxy blends exhibited significantly higher fracture toughness（by 23% at most） compared with the neat samples. The improvement of the fracture toughness was attributed to the stick-slip mechanism for crack growth and activation of shear yielding and plastic deformation around the crack growth trajectories for samples with higher content of bifunctional epoxy resin as evidenced by fractography study.

关键词： Epoxy Blend Functionality Mechanical property Toughness

Effects of intermediate Ni layer on mechanical properties of Al–Cu layered composites fabricated through cold roll bonding

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International Journal of Minerals,Metallurgy and Materials 2018年第5期25卷 573-583页

作者： ali Shabani mohammad Reza Toroghinejad alireza Bagheri Department of Materials Engineering Isfahan University of Technology

Layered composites have attracted considerable interest in the recent literature on metal composites. Their mechanical properties depend on the quality of the bonding provided by the intermediate layers. In this study, we analyzed the mechanical properties and bond strengths provided by the nickel layer with respect to its thickness and nature(either powder or coating). The results suggest that bond strength decreases with an increase in the content of nickel powder. At 0.3 vol% of nickel coating, we found the nature of nickel to be less efficient in terms of bond strength. A different picture arose when the content of nickel was increased and the bond strength increased in nickel coated samples. In addition, the results demonstrate that mechanical properties such as bend strength are strongly dependent on bond strength.

关键词： cold roll bonding Al/Ni/Cu composite mechanical testing metallography

Peak displacement patterns for the performance-based seismic design of steel eccentrically braced frames

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Earthquake Engineering and Engineering Vibration 2019年第2期18卷 379-393页

作者： ali Fakhraddini Hamed Saffari mohammad Javad Fadaee Department of Civil Engineering Shahid Bahonar University of Kerman

Performance-based seismic design(PBSD) aims to assess structures at different damage states. Since damage can be directly associated to displacements, seismic design with consideration of displacement seems to be logical. In this study, simple formulae to estimate the peak floor displacement patterns of eccentrically braced frames(EBFs) at different performance levels subjected to earthquake ground motions are proposed. These formulae are applicable in a PBSD and especially in direct displacement-based design(DDBD). Parametric study is conducted on a group of 30 EBFs under a set of 15 far field and near field accelerograms which they scaled to different amplitudes to adapt various performance levels. The results of thousands of nonlinear dynamic analyses of EBFs have been post-processed by nonlinear regression analysis in order to recognize the major parameters that influence the peak displacement pattern of these frames. Results show that suggested displacement patterns have relatively good agreement with those acquired by an exact nonlinear dynamic analysis.

关键词： performance-based seismic design direct displacement-based design displacement pattern eccentrically braced frames steel building

A trapdoor one-way function for verifiable secret sharing

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High-Confidence Computing 2022年第2期2卷 34-40页

作者： ali Kanso mohammad Ghebleh Department of Mathematics Kuwait UniversityKuwait CityKuwait

This paper proposes a(t,n)-threshold verifiable secret sharing scheme with changeable parameters based on a trapdoor one-way *** scheme consists of a generation phase,a distribution phase,an encoding phase and a reconstruction *** generation and distribution phases are,respectively,based on Shamir’s and Feldman’s approaches,while the encoding phase is based on a novel trapdoor one-way *** the reconstruction phase,the shares and reconstructed secret are validated using a cryptographic hash *** comparison with existing schemes,the proposed scheme leaks no direct information about the secret from public ***,unlike some existing schemes,the generation and distribution phases of the proposed scheme are both independent of the *** feature leads to a number of advantages over existing approaches such as the dealer’s ability to perform the following modifications without updating the shares(i)modify the secret and(ii)adjust the threshold parameters of the ***,each participant receives a single share,and designated participants can be given the privilege of choosing their own shares for reconstructing a secret ***,the proposed scheme possesses a high level of security which is inherited from the schemes of Shamir and Feldman,in addition to the trapdoor one-way function and the employed cryptographic hash function.

关键词： Shamir’s scheme Feldman’s scheme Verifiable secret sharing schemes Secret sharing schemes with changeable threshold parameters Trapdoor one-way function Hash function

Mitigating the catastrophic impacts of torrential rivers in semi-arid environments: a case of the Gash River in eastern Sudan

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Journal of Arid Land 2011年第3期3卷 174-183页

作者： Samir mohammad ali Alredaisy Department of Geography Faculty of EducationUniversity of Khartoum

The climatic, geomorphic, hydrologic and aquifer characteristics of the torrential Gash River across mountainous areas, in far eastern Sudan, were analyzed in order to mitigate its recurring catastrophic impacts. Hydrologic and climatic data and interpretation of Gash River satellite images were from relevant research works carried out in Gash Basin from 1985 to 2008. The results indicated that the total catchment area of Gash River is about 21,000 km2, and the basin area is 31,000 km2. The total length of Gash River is 450 km and the average slope is 200 cm/km. The width of the catchment varies from 30 m to 90 m and that of the basin is from 100 m to 800 m, and the course of the river is varied. During the period of 1980？2008, the mean annual rainfall was 250 mm and the mean annual discharge was 6.8 ×10~8 m^3, and the flooding is approximately one time per 5 years. Torrential floods measured at Kassala town since 1907 showed that an absolute maximum discharge was 876 m3/s and a mean maximum discharge was 365 m3/s. These characteristics differ widely between catchment and basin areas. The author proposes that, by analyzing the climatic, geomorphic, hydrologic and aquifer characteristics of the Gash River and considering the role of community, a concise database could be provided to formulate the aquifer, geomorphic, hydrologic and climatic （AQUIGEOHYCLIM） regional approach to mitigate Gash River recurring catastrophic impacts.

关键词： AQUIGEOHYCLIM Gash River basin climate geomorphology hydrology mitigation water management

Microscopic and macroscopic atomization characteristics of a pressure-swirl atomizer, injecting a viscous fuel oil

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Chinese Journal of Chemical Engineering 2020年第1期28卷 9-22页

作者： Seyed mohammad ali Najafi Pouria Mikaniki Hojat Ghassemi School of Mechanical Engineering Iran University of Science and Technology(IUST)P.O.B.16765-163TehranIran

Combustion of heavy fuels is one of the main sources of greenhouse gases, particulate emissions, ashes, NOxand SOx. Gasification is an advanced and environmentally friendly process that generates combustible and clean gas products such as hydrogen. Some entrained flow gasifiers operate with Heavy Fuel Oil(HFO) feedstock. In this application, HFO atomization is very important in determining the performance and efficiency of the *** atomization characteristics of HFO(Mazut) discharging from a pressure-swirl atomizer(PSA) are studied for different pressures difference(Δp) and temperatures in the atmospheric ambient. The investigated parameters include atomizer mass flow rate( _m), discharge coefficient(CD), spray cone angle(θ), breakup length(Lb), the unstable wavelength of undulations on the liquid sheet(λs), global and local SMD(sauter mean diameter) and size distribution of droplets. The characteristics of Mazut sheet breakup are deduced from the shadowgraph technique. The experiments on Mazut film breakup were compared with the predictions obtained from the liquid film breakup model. Validity of the theory for predicting maximum unstable wavelength was investigated for HFO(as a highly viscous liquid). A modification on the formulation of maximum unstable wavelength was presented for HFO. SMD decreases by getting far from the atomizer. The measurement for SMD and θ were compared with the available correlations. The comparisons of the available correlations with the measurements of SMD andθ show a good agreement for Ballester and Varde correlations, respectively. The results show that the experimental sizing data could be presented by Rosin-Rammler distributions very well at different pressure difference and temperatures.

关键词： Gasifier Heavy fuel oil Atomization Pressure-swirl atomizer Mazut Size distribution Wavelength Viscosity

Evaluation the Properties of Polycaprolactone/Fluorapatite Nano-biocomposite

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Journal of Bionic Engineering 2022年第1期19卷 179-187页

作者： Mojtaba Momeni Kamran Amini ali Heidari mohammad Khodaei Department of Mechanical Engineering Khomeinishahr BranchIslamic Azad UniversityKhomeinishahr84181-48499IsfahanIran Center for Advanced Engineering Research Majlesi BranchIslamic Azad University86316-56451IsfahanIran Materials Engineering Group Golpayegan College of EngineeringIsfahan University of Technology87717-67498GolpayeganIran

In this study,nano-biocomposites of polycaprolactone(PCL)as the matrix and different amounts of nanofluorapatite(nFA)(0,10,20 and 30 wt.%)as the reinforcement were prepared for possible scaffold fabrication using the fused filament fabrication(FFF)3D *** Emission Scanning Electron Microscopy(FE-SEM)and Energy Dispersive Spectroscopy(EDS)showed that nFA particles were well distributed in the PCL matrix.X-ray diffraction analysis(XRD)and Fourier Transform Infrared Spectroscopy(FTIR)depicted no chemical interaction between the elements of the *** Scanning Calorimetric(DSC)analysis was then used to assess the thermal properties of the composites,suggesting that this could be due to the amorphous phase formation of the intermolecular hydrogen bonds between PCL and nFA,resulting in the suppression of PCL *** results of mechanical characterization also showed that the addition of nFA up to 20 wt.%to the PCL increased the tensile and yield strength,as well as reducing the elongation at both yield and failure points and increasing the Young *** best mechanical properties were obtained for the PCL/20nFA *** strength and Young modulus were increased by 30%and 179%,respectively;meanwhile,elongation of PCL/20nFA was decreased by 70%,as compared to the naked *** changes could be attributed to the better distribution of the nFA filler in the PCL *** to the obtained results,PCL/20nFA could be regarded as a good composite in terms of the mechanical properties for the regeneration of the bone tissue.

关键词： Nano-biocomposite Polycaprolactone Fluorapatite Bone tissue engineering Mechanical properties

Seismic control of multi-degrees-of-freedom structures by vertical mass isolation method using MR dampers

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Earthquake Engineering and Engineering Vibration 2024年第2期23卷 503-510页

作者： Mohamad Shahrokh Abdi Masoud Nekooei mohammad-ali Jafari Department of Civil Engineering Marivan BranchIslamic Azad UniversityMarivan ***Iran Department of Civil Engineering Science and Research BranchIslamic Azad UniversityTehran ***Iran Structural Department of Transmission and Distribution Research Center Niroo Research Institute(NRI)Tehran ***Iran

Vertical mass isolation(VMI)is one of the novel methods for the seismic control of *** this method,the entire structure is assumed to consist of two mass and stiffness subsystems,and an isolated layer is located among *** this study,the magnetorheological damper in three modes:passive-off,passive-on,and semi-active mode with variable voltage between zero and 9 volts was used as an isolated layer between two ***-degrees-of-freedom structures with 5,10,and 15 floors in two dimensions were examined under 11 pairs of near field *** each level,the displacement of MR dampers was taken into *** responses of maximum displacement,maximum inter-story drift,and maximum base shear in controlled and uncontrolled buildings were compared to assess the suggested approach for seismic control of the *** to the results,the semi-active control method can reduce the response by more than 12%compared to the uncontrolled mode in terms of maximum displacement of the mass subsystem of the *** method can reduce more than 16%and 20%of the responses compared to the uncontrolled mode in terms of maximum inter-story drift and base shear of the structure,respectively.

关键词： seismic control vertical mass isolation base shear magnetorheological damper semi-active control