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1.
Habibeh Haddad Dabaghi Abdolmajid Bayandori Moghaddam Mahmood Kazemzad Rassoul Dinarvand Fezze Aryanasab Mohammad Reza Nabid 《Journal of Applied Electrochemistry》2008,38(3):409-413
Electrochemical treatment processes can significantly contribute to the protection of the environment through the minimization
of waste and toxic materials in effluents. From a pharmaceutical point of view and due to the existing resemblance between
the electrochemical and biological reactions, it can be assumed that the oxidation mechanisms on the electrode and in the
body share similar principles. In this paper, the application of electrochemical studies in the design of an environmentally
friendly method was delineated for the new hydrocaffeic acid (HCA, 3,4-dihydroxy hydrocinnamic acid) derivatives synthesis
at carbon electrodes in an undivided cell. In this cell, the EC mechanism reaction was involved, comprising two steps alternatively;
(1) electrochemical oxidation and (2) chemical reaction. In particular, the electro-organic reactions of HCA, an important
biological molecule, were studied in a water–acetonitrile (90:10 v/v) mixture in the presence of benzenesulfinic acid (3) and p-toluenesulfinic acid (4). The research included the use of a variety of experimental techniques, such as cyclic voltammetry, controlled-potential
electrolysis and product spectroscopic identification. 相似文献
2.
Orientation-based coding approaches have recently been widely employed for face and palmprint recognition where generally, one starts with a set of Gabor filters to extract orientation information and then proceeds to code dominant orientations as features for each point of the palmprint. However, as the Gabor filter is developed to model two-dimensional receptive fields of simple cells in straits cortex, it might not be our best choice when dealing with curved and complex structures inherent in the palmprint texture. Motivated by this intuition, this paper shows that Gabor filters are a subset of a bigger family of filters which we refer to as generalized Gabor filter (GGF). Depending on the values of its parameters, a GGF takes a rather diverse shapes and orientations, which results in a potentially finer feature extraction capability. We show this improved capability by employing GGFs in the palmprint verification process. In applying our method, two different sub-banks of GGFs are defined for the orientation-based feature extraction of palmprints, and when compared with Gabor filters, it will be shown that GGFs have the upper hand in capturing orientation features. Furthermore, compared with the competitive code—one of the well-known orientation-based coding methods—the number of employed orientations is reduced to half. This would automatically compensate for a double usage of the filter banks, which otherwise could increase the time complexity of using GGFs. These ideas are further elaborated using a set of experiments on PolyU II and PolyU 2D/3D palmprint databases. The results show the preeminence of using GGFs both in terms of accuracy and efficiency. 相似文献
3.
Seyed Hadi Ghaderi Hassan Moslemi NaeiniGholam Hossein Liaghat 《International Journal of Impact Engineering》2007
Based on the concept of Tensor Code a numerical method is presented for analysis of the plastic deformation process of circular sheet metals subjected to transverse impact loading. In the solution process, the equation of motion is solved explicitly with finite difference method in a series of small time steps over a Lagrangian mesh of zones. Using this method, a code has been developed and utilized for investigation of the deformation behavior of an explosively loaded circular sheet metal under various conditions. Deformation characteristics of a sheet under rectangular and triangular pressure distributions are discussed. It is shown that when these simple distributions are combined with each other, their individual effects on the deformation behavior are also combined in the deformation process. Effects of shape and duration of pressure pulse as well as boundary conditions have been explored. Moreover, results of the numerical simulation have been compared with those of theoretical solution and experiments reported by other researchers. Good agreements between them show the validity of the developed code. 相似文献
4.
N.R. Chitkara G.H. Liaghat 《The International Journal of Advanced Manufacturing Technology》2001,17(12):889-909
An experimental investigation into the quasi-static open-piercing of sintered aluminium powder compacts made initially in
the form of thin and thick disks was made, using four different shaped punches, i.e. solid circular, annular (circular ring-type),
triangular, and square. Typical results of punch load with punch movement and progressive changes in shapes of the specimens
were observed and the onset of fracture was noted in each case. Available theory for calculating the piercing force was applied
in a few cases and the results were compared with the experiments. These and other observations on the mechanical and metallurgical
aspects of the deformation are given and the results commented upon. 相似文献
5.
In this article, the ballistic behavior of the glass/epoxy/nanoclay hybrid nanocomposites is studied. The fiber glass used is a plain weave 200 g/m2, while the nanoclay is an organically modified montmorillonite nanoclay (Closite 30B). The epoxy resin system is made of Epon 828 as the epoxy prepolymer and Jeffamine D‐400 as the curing agent. 0, 3, 5, 7, and 10 wt% of nanoclay particles are dispersed in the epoxy resin. Ballistic tests are performed using flat‐ended projectiles in impact velocities 134 m/s and 169 m/s. The results show that the energy absorption capability and mechanical properties of the composite can be significantly enhanced by adding nanoparticles. When the impact velocity is 134 m/s, near than the ballistic limit, the most increase in the energy absorption capability is observed in 3 wt% nanoclay while with the impact velocity 169 m/s, beyond the ballistic limit, the highest increase is observed in 10 wt% nanoclay. POLYM. COMPOS., 37:1173–1179, 2016. © 2014 Society of Plastics Engineers 相似文献
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In the paper published by Wu and Jiang (Int. J. Impact. Eng. 19(5/6) (1997) 439), the experimental results of quasi-static and impact tests on six types of honeycomb cellular structures have been compared with theoretical predictions. The values of some of the parameters used in the formulae in their paper, seem to be incorrect. In this paper the cause of inaccuracy and the correct values of these parameters have been presented. 相似文献
8.
Mohammad Reza Nabid Maryam Golbabaee Abdolmajid Bayandori Moghaddam Ali Reza Mahdavian Mostafa Mohammadpour Amini 《Polymer Composites》2009,30(6):841-846
Peroxidase-catalyzed template-guided polymerization of aniline in the presence of γ- alumina nanosheet (NS) particles have been carried out in aqueous media and γ-Al2O3/PANI nanocomposite was obtained. The polymerization of aniline occurred in aqueous solution in the presence of SPS (sulfonated polystyrene) as a template and SDS (sodium dodecyl sulfate) as a surfactant. Both obtained nanocomposites were comparable by SEM images. It was demonstrated that the γ-Al2O3 NS/PANI-SPS nanocomposite has higher conductivity and the γ-Al2O3 NS/PANI-SDS nanocomposite has higher void areas. The higher conductivity of γ-Al2O3 NS/PANI-SPS nanocomposite is attributed to the higher coated areas of γ-Al2O3 NS during polymerization in comparison with γ-Al2O3 NS/PANI-SDS which are not coated efficiently as the former. The FT-IR studies showed that the γ-Al2O3 NS/PANI nanocomposite was formed by interaction of the polyaniline (PANI) and γ-Al2O3 NS. FTIR also showed that the amount of PANI in γ-Al2O3 NS/PANI-SPS is more than in γ-Al2O3 NS/PANI-SDS. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers 相似文献
9.
Rasoul Safdarian Korouyeh Hassan Moslemi Naeini Gholamhosein Liaghat 《Journal of Materials Engineering and Performance》2012,21(10):2053-2061
The forming limit diagram (FLD) is a useful method for characterizing the formability of sheet metals. In this article, different numerical models were used to investigate the FLD of tailor-welded blank (TWB). TWBs were CO2 laser-welded samples of interstitial-free (IF) steel sheets with difference in thickness. The results of the numerical models were compared with the experimental FLD as well as with the empirical model proposed by the North American Deep Drawing Research Group. The emphasis of this investigation is to determine the performance of these different approaches in predicting the FLD. These numerical models for FLD are: second derivative of thinning (SDT), effective strain rate (ESR), major strain rate (MSR), thickness strain rate (TSR), and thickness gradient (TG). Results of this research show necking will be happened, when the value of MSR, TSR, ESR criteria is maximum, TG????0.78 and SDT criterion has the first peak in forming process time. The value of dome height of TWB samples at failure was predicted based on the numerical models for samples with different widths. These numerical predictions were compared with the experimental results. The SDT model indicates a better agreement with experimental results in prediction of both the FLD and the limit dome height (LDH) in comparison to the other numerical models. Both numerical and experimental results show that minimum of LDH is happened in plane strain condition. 相似文献
10.
Seyed Jalal Hashemi Hassan Moslemi Naeini Gholamhosein Liaghat Roohollah Azizi Tafti Farzad Rahmani 《Journal of Materials Engineering and Performance》2013,22(1):57-63
Reduction of weight and increase of corrosion resistance are among the advantageous applications of aluminum alloys in automotive industry. Producing complicated components with several parts as a uniform part not only increases their strength but also decreases the production sequences and costs. However, achieving this purpose requires sufficient formability of the material. Tube hydroforming is an alternative process to produce complex products. In this process, the higher the material formability the more uniform will be the thickness distribution. In this research, tube hydroforming of aluminum alloy (AA1050) at various temperatures has been investigated numerically to study temperature effect on thickness distribution of final product. Also a warm hydroforming set-up has been designed and manufactured to evaluate numerical results. According to numerical and experimental results in the case of free bulging, unlike the constrained bulging, increase of the process temperature causes more uniform thickness distribution and therefore increases the material formability. 相似文献