Performance of steel beams strengthened with pultruded CFRP plate under various exposures

M. Gholami,A.R. Mohd Sam,A.K. Marsono,M.M. Tahir,I. Faridmehr 국제구조공학회 2016 Steel and Composite Structures, An International J Vol.20 No.5

The use of Carbon Fiber Reinforced Polymer (CFRP) to strengthen steel structures has attracted the attention of researchers greatly. Previous studies demonstrated bonding of CFRP plates to the steel sections has been a successful method to increase the mechanical properties. However, the main limitation to popular use of steel/CFRP strengthening system is the concern on durability of bonding between steel and CFRP in various environmental conditions. The paper evaluates the performance of I-section steel beams strengthened with pultruded CFRP plate on the bottom flange after exposure to diverse conditions including natural tropical climate, wet/dry cycles, plain water, salt water and acidic solution. Four-point bending tests were performed at specific intervals and the mechanical properties were compared to the control beam. Besides, the ductility of the strengthened beams and distribution of shear stress in adhesive layer were investigated thoroughly. The study found the adhesive layer was the critical part and the performance of the system related directly to its behavior. The highest strength degradation was observed for the beams immersed in salt water around 18% after 8 months exposure. Besides, the ductility of all strengthened beams increased after exposure. A theoretical procedure was employed to model the degradation of epoxy adhesive.

Process optimization and modeling of heavy metals extraction from a molybdenum rich spent catalyst by Aspergillus niger using response surface methodology

R. Mafi Gholami,S.M. Mousavi,S.M. Borghei 한국공업화학회 2012 Journal of Industrial and Engineering Chemistry Vol.18 No.1

The present study examines the biorecovery of heavy metals from a spent refinery catalyst obtained from one of the oil refineries in Iran using Aspergillus niger. Bioleaching experiments were carried out in batch cultures using A. niger in the one-step process to mobilize Co, Mo and Ni from hazardous spent catalysts. Response surface methodology (RSM) was applied for the design and analysis of experiments with the optimization of pH, temperature, inoculum percentage, pulp density and rotation speed during the bioleaching of the metals. Experiments were designed as per the central composite design (CCD)technique. Three cubic mathematical models were derived for prediction of the responses. In process optimization, maximal values of Co, Mo and Ni recoveries were achieved as 71%, 69% and 46%,respectively, with a pH of 5.0, a temperature of 31 8C, a pulp density of 2 g/L, a rotation speed of 115 rpm,and using a 12% inoculum.

Preparation and characterization of polyvinyl chloride based nanocomposite nanofiltration-membrane modified by iron oxide nanoparticles for lead removal from water

A. Gholami,A.R. Moghadassi,S.M. Hosseini,S. Shabani,F. Gholami 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.4

In this research (polyvinyl chloride-blend-cellulose acetate/iron oxide nanoparticles) nanocomposite membranes were prepared by casting technique to lead removal from wastewaters. The effect of blend ratio of polymer binder (PVC to CA) and Fe3O4 nanoparticles concentration on physico-chemical characteristics of membranes were studied. Water permeability and ionic rejection tests, water content and mechanical properties measurements and SEM analysis were carried out in membranes characterizations. Obviously, modified membrane containing 10 wt% CA and 0.1 wt% Fe3O4 nanoparticles showed better performance in lead removal compared to other modified membranes and also pristine ones.

First principles study of the I–V characteristics of the alkane-thiols nano-molecular wires

H. Aghaie,M.R. Gholami,M.D. Ganji,M.M. Taghavi 한국물리학회 2009 Current Applied Physics Vol.9 No.3

We report a density functional non-equilibrium Green’s function study of electrical transport in a single molecular conductor consisting of an ethane-dithiolate (C2H4S2) molecular wire with two sulfur end groups bonded to the Au(111) electrodes. We show that the current was increased by increasing the external voltage biases. The projected density of states (PDOS) and transmission coefficients T(E) under various external voltage biases are analyzed, and it suggests that the variation of the coupling between the molecule and the electrodes with external bias leads to the increase of the current. Furthermore, the investigation of the transport properties of the pentane- dithiolate (C5H10S2) molecular wire shows that the pentane-dithiolate molecular wire has a lower conductivity than the ethanedithiolate wire. We report a density functional non-equilibrium Green’s function study of electrical transport in a single molecular conductor consisting of an ethane-dithiolate (C2H4S2) molecular wire with two sulfur end groups bonded to the Au(111) electrodes. We show that the current was increased by increasing the external voltage biases. The projected density of states (PDOS) and transmission coefficients T(E) under various external voltage biases are analyzed, and it suggests that the variation of the coupling between the molecule and the electrodes with external bias leads to the increase of the current. Furthermore, the investigation of the transport properties of the pentane- dithiolate (C5H10S2) molecular wire shows that the pentane-dithiolate molecular wire has a lower conductivity than the ethanedithiolate wire.

Genetic Improvement of Some Traits in Four Strains of Silkworm, Bombyx mori L.

Moghaddam S. H. Hosseini,Jomeh K. N. Emam,Mirhosseini S. Z.,Gholamy M. R. Korean Society of Sericultural Science 2005 International Journal of Industrial Entomology Vol.10 No.2

A breeding plan was carried out on four commercial strains of silkworm (Bombyx mori L.) 101, 102, 103 and 104 to improve some important traits. Genetic gain or response to selection $({\Delta}G)$, heritability of cocoon shell weight (CSW) and specific combining ability effects were estimated to determine the strains that can be improved. Strain 101 had lowest heritabitity, ${\Delta}G$ and viability. Strain 102 was acceptable in selection response but its viability was low. Therefore these two strains were not suitable for more selection. As a result, only lines 103 and 104 were chosen for further improvement. Intra population selection based on independent culling level method practiced from third to sixth generation for both productive and viability traits simultaneously. While CSW and CW had increasingly enhanced during primary generations, they went slightly up after third generation. According to negative genetic correlation, viability decreased during primary generations, but after third generation that paid attention to balanced development of both productive and viability traits, viability increased so that the pupation rate reached to $91\%$ in 103 and $97\%$ in 104 for last generation $(G_8)$.

Genetic Improvement of Some Traits in Four Strains of Silkworm, Bombyx mori L.

( S. H. Hosseini Moghaddam ),( N. Emam Jomeh K. ),( S. Z. Mirhosseini ),( M. R. Gholamy ) 한국잠사학회 2005 International Journal of Industrial Entomology Vol.10 No.2

A breeding plan was carried out on four commercial strains of silkworm (Bombyx mori L.) 101, 102, 103 and 104 to improve some important traits. Genetic gain or response to selection (△G), heritability of cocoon shell weight (CSW) and specific combining ability effects were estimated to determine the strains that can be improved. Strain 101 had lowest heritabitity, △G and viability. Strain 102 was acceptable in selection response but its viability was low. Therefore these two strains were not suitable for more selection. As a result, only lines 103 and 104 were chosen for further improvement. Intra population selection based on independent culling level method practiced from third to sixth generation for both productive and viability traits simultaneously. While CSW and CW had increasingly enhanced during primary generations, they went slightly up after third generation. According to negative genetic correlation, viability decreased during primary generations, but after third generation that paid attention to balanced development of both productive and viability traits, viability increased so that the pupation rate reached to 91% in 103 and 97% in 104 for last generation .(G8)