Iranica Journal of Energy and Environment (IJEE)

312-319

Authors: Jiravut Seengenyoung, Poonsuk Prasertsan and Sompong O-Thong

The effect of alkaline and acid pretreatment on solubilization of solid organic matter in palm oil mill effluent (POME) and hydrogen production by Thermoanaerobacterium-rich sludge was studied. Organic matter solubilization of alkaline and acid pretreatments were increased up to 28 and 15.7% of initial soluble COD in POME, respectively. That corresponds to carbohydrate solubilization of 41 and 32% of initial soluble carbohydrate in POME, respectively. A maximum hydrogen production yield of 4.6 l H2/l-POME was achieved from POME pretreated with 1.5% w/v NaOH, which was 3-fold greater than raw POME and 1-fold greater than POME pretreated with 1.5% w/v HCl. Optimum conditions for biohydrogen production from alkaline pretreated POME using Thermoanaerobacterium-rich sludge was found at initial pH 5.5 and temperature of 60°C, which gives a maximum hydrogen production yield of 5.2 l H2/l-POME and increased 51% as compared to raw POME. The biogas was mainly composed of hydrogen and carbon dioxide with the percentage of hydrogen ranging from 55-60% of biogas and free of methane. During the conversion of alkaline pretreated POME into hydrogen, the acetic and butyric acids were main by-products in the metabolism. The results showed that alkaline pretreatment is an effective pretreatment methods for enhancing the hydrogen production yield from POME. The use of Thermoanaerobacterium-rich sludge is promising for future engineering practice of biohydrogen production from alkaline pretreated POME.

330=335

Authors: Fatemeh Ardestani

Mycophenolic acid (MPA) is an antibiotic and immunosuppressive agent, as a secondary metabolite of Penicillium brevicompactum. Parameter optimization of culture composition using Test plan L16, available in the form of an orthogonal array and software for automatic design and analysis of the experiments, both based on Taguchi approach was performed in MAP production process by Penicillium brevicompactum ATCC 16024 in a batch submerged culture. Optimal levels of key parameters including glucose, enzymaticaly hydrolyzed casein, methionine and glycine concentrations were determined. Optimum glucose, enzymaticaly hydrolyzed casein, methionine and glycine concentrations were obtained 80, 25, 1.2 and 20 g. L 1, respectively. Theoretically expected and also experimentally actual obtained mycophenolic acid concentrations under the optimal conditions were 2.025 and 1.995 g. L 1, respectively with a good consistency as 98.5%. Analysis showed the glucose concentration was found to be the most significant factor as well as glycine concentration was the less important factor on MPA production in the investigated process.

343-347

Authors: Mohammad Mahdi Mardanpour, Mohsen Nasr Esfahany, Tayebeh Behzad, Ramin Sedaqatvand, Forough Sharifi and Fatemeh Naderi

In this study, the single chamber microbial fuel cell (MFC) with annular configuration and spiral anode geometry is proposed for future large-scale applications. Dairy wastewater containing complex organic matter was used as substrate. Factors affecting power generation and internal resistance of this MFC such as substrate injection, electrode surface area, and substrate concentration were investigated to elucidate the effects of the MFC configuration and operating conditions on its performance. The results show that with decreasing anode surface area output current is reduced. With decreasing anode surface area from 2×63 to 2×38cm, output current is reduced about 34%. In measurement of open dircuit voltage, replacement of old wastewater by fresh ones the open circuit voltage significantly increased. Also, enhancement of wastewater concentration shows an increase in the MFC power density. The MFC which was fed with wastewater with lower COD had a shorter batch time than that of the higher wastewater COD.

357-360

Authors: Ehsan Zarmehri, Morteza Sadeghi and Arjomand Mehrabani-Zeinabad

Bipolar plates play the most significant role in weight, volume and corresponding costs of fuel cells. Initially, metallic and graphite materials had been used for production of bipolar plates due to their electrical conductivity characteristics. Later, these plates due to their deficiency such as corrosion, weight and production expenses were appropriately substituted by composite plates. This article presents results of a study on construction of bipolar plates using conductive polymeric composites. In the constructed composites, polypropylene was implement as polymer matrix and conductive carbon black and graphite as filler in order to supply the required electrical conductivity. The added fillers have been distributed in polypropylene by using an internal mixer. Then, bipolar plate specimens were prepared by molding of composite in hot press. The prepared specimens have been characterized to evaluate their specifications such as mechanical properties and their performance properties like thermal and electrical conductivities. The results of performed tests have shown a good performance on thermal conductivity greater than 10W/m.K, electrical conductivity higher than 50S/cm and high mechanical strength, flexural strength greater than 25MPa. The constructed composite plates were optimized and their weight in compare to similar metallic plates 80% and in contrast to graphite plates 40% were reduced. This method for production of bipolar plates is more economical as it reduces the cost of used materials and expenses of manufacturing operations.

376-384

Authors: H. Hassanzadeh Afrouzi and M. Farhadi

In the present study, mixed convection flow was investigated by Lattice Boltzmann method in a square lid-driven cavity utilizing nanofluid in presence of cubic obstacle. The fluid in the cavity was a water-based nanofluid containing Cu nanoparticles. The study was carried out for a constant Rayleigh number 10 , the Richardson number ranging from 0.1 to 10 and the solid volume 4 fraction ranging from 0 to 0.03. The effects of solid concentrations on hydrodynamic and thermal characteristics were investigated. The results were presented in the form of streamlines and temperature contours for different values of solid volume fractions and Richardson numbers. The results indicated that the averaged Nusselt number increases byaugmentation of solid volume fraction. The Richardson number had more effect on Nusselt number when obstacle was located at the bottom section of enclosure.

391-397

Authors: Mostafa Keshavarz Moraveji, Reza Davarnejad and MarziehFarjami

Having accurate values of the parameters which mainly govern the industrial processes in hand is the key aspect to handle the process and optimize it. To deal with this challenge, some mathematical models have been developed and modified to be epidemic. This Study aims to present the simulation of gas-solid flow in fluidized bed dryer. Numerical solution of two-dimensional, axis-symmetrical cylindrical model for both phases is the very base on which this study is conducted. Some of the versatile parameters like inlet gas velocity and temperature, diameter and density of particles during drying process went under magnification and also challenges of heat transfer along the bed are investigated and discussed in detail. Solid temperatures in the center and on the surface which are greatly affected by time as well as results of the study are shown. At the end, model outputs are compared with experimental data which shows reasonable agreement and good match.

406-418

Authors: Feridon Ghadimi, Mohammad Ghomi, Mohsen Ranjbar and Abdolmotaleb Hajati

Present investigation was performed to provide heavy metal signatures of urban dusts and to evaluate potential sources in Arak, Markazi province. Twenty- nine samples of urban dusts were collected in Arak city. Then Pb, Cu, Ni, Zn, Cr, Hg and As concentrations were determined by using atomic absorption spectrophotometry. The results indicate that, in comparison with Iran soil, urban dusts in some of the area in Arak have elevated metal concentrations, except those of Ni, Zn, Hg and As. Correlation coefficient analysis, principal component analysis (PCA) and cluster analysis (CA) were performed and three main sources with corresponding cluster elements were identified: (1) Zn, Cr, Hg and As have soil and industrial sources; (2) Pb and Ni are mainly derived from industrial sources, combined with traffic sources; (3) Cu come mainly from industrial sources. Geoaccumulation index (Igeo), enrichment factors (EF) and contamination degree (Cd) were calculated, which in turn further confirms the source identification. Also, Igeo, EF and Cd give an insight of human influence degree of urban dusts.

425-432

Authors: Nasser Baharlou Houreh and Ebrahim Afshari

Present study investigates the cathode gas channel of proton exchange membrane fuel cell that is partially blocked by one or more baffle plates. In order to investigate the effects of the selected shape, size and the number of baffles on oxygen transport in the gas diffusion layer a numerical modeling is carried out in 27 cases. With consideration of both maximum oxygen concentration in the gas diffusion layerand reasonable pressure drop, the results indicate that in all cases, an increase in baffle height is more effective than an increase in number of baffle plates. Also, installing three large rectangular baffles seem quite appropriate, but when there is restriction in securing pressure in fuel cell, installing the semicircle baffle is better than the rectangular one.

171 - 177

Authors: Woo Yian Peen, Chua Yie Sue, Choong Kok Keong

The Cholla cactus skeleton has been the inspiration source for this study, in our effort to search forlight and more structural effective structures. This woody skeleton of Cholla with oval shaped perforationsarranged in spiral pattern is found strong enough to support the cactus self weight. This research has beencarried out to investigate the effects of percentage of perforations and perforations arrangements on structuralbehaviour of cylindrical hollow section. A total of eleven models consisting of one cylindrical hollow sectionwithout perforation as the control model and ten simplified perforated cylindrical hollow sections have beenconstructed using a finite element method software. The perforated models have been assigned with 10 to 50percent of perforations area by fixing the number of perforations to twenty and altering the perforation size toachieve the percentage variable. Computational analyses have been carried out for three loading conditions:compressive, flexural and torsional. Findings have shown that the increment in percentage of perforationsproduces higher stresses to the cylindrical hollow section. This has effects on the structural capacity of thecylindrical hollow section. Array arrangement of the perforations shows better structural performance incompression and flexural loading conditions while spiral arrangement exhibits better structural performanceunder torsional loading condition.

186 - 198

Authors: Morteza Naghipour, Saleh Mohammad Ebrahimzadeh Sepasgozar

Today Steel moment resistance connections are the most common type of connections that are widely used in steel structures and certainly play a significant role in retrofitting, reliability and economic benefits.It is used also for improvement of the quality and useful life cycle of buildings. Considering the motions importance and after the Northridge earthquake, the invention of RBS connection was a turning point inresistant steel moment connections. This research observes the seismic behavior of the RBS connection with reduced section of flange and a new AW- RBS with reduced section of web in a double section beams that are applicable in Iran. These observations are performed using ABQUS finite elements software. Many models are implemented under cycle loads and ductility. Energy absorption and plastic behavior in the reduced section were observed. Among the studied connections, AW- RBS with the least resistance and stiffness decrement had bearded 8% off the rotation of the story. These models have acceptable behavior in cyclic loads.

208 - 211

Authors: Gholamreza Abdollahzadeh, Seyed Mostafa Shabanian

Behavioral study of connections using moment - rotation curve for analyzing different types ofconnections and also the concept of strength, ductility and rigidity of steel connections are important. One ofthe most common connections in bending frames of steel structures is beam to column connections with flangeplates. A correct perception about structural behavior of beam to column connections and also appropriateknowledge of their force transmission and their behavior in modeling and analysis of the steel structures areessential. In present study, beam to column steel connection with flange plate under monotonic loading, bothanalytical and experimental would be investigated. The obtained results showed that moment - rotation curvesof experimental sample and finite element (F.E.) model are reasonably close to each other. As a result, F.E.method could be an appropriate tool to investigate the behavior of these connections which would significantlydecrease number of trial and error approaches.

219 - 222

Authors: Fatimah De’nan, MusniraMustar, Adzhar Bin Hassan, Norbaya Omar

Shear buckling occurred in the instability modes of steel beams when it slender. This paper develops a three-dimensional finite element model using LUSAS 14.3 to study on the effect of the triangular steel beam web profile (T WP) in shear buckling behaviour of different thickness compared RI to that of the normal flat beam (FW).All specimens are cantilever beam which are fixed at one ends. The flange is constant with variable web thickness. Eigenvalue buckling analysis was used in analysing the buckling load of the flat plate model and triangular web profile (TRIWP). Results showed that the web thickness gave a significant impact on the shear buckling of the TRIWP. In addition, the corrugation thickness of web was also effective in increasing the shear buckling capacity of the profile.

238 - 242

Authors: Gholamreza Abdollahzadeh, Seyed Mostafa Shabanian

Study destructive earthquakes which have occurred in recent year's shows that beam to column connection are the main component of force transmission and also play a vital role in stability of structure; such failure of these connections could lead to the destruction of structures. In current study, the behavior of beam to column steel connection with flange plate was studied by using component method. The correctness of results was examined by comparing the moment-rotation curve of beam to column connection with flange plate under monotonic loading which was obtained by component method and experimental method. Studying the result shows that moment-rotation curve which was obtained by component and by experiments method are reasonably close to each other. Therefore, it could be concluded that this component method is an appropriate tool for studying the behavior of this connections.

251 - 257

Authors: Yee Hooi Min, Choong Kok Keong

Form-finding of tensioned fabric surface bordered by Möbius strip is investigated. Möbius strip is a surface with only one side and only one boundary component. Möbius strip has the mathematical property of being non-orientable. The form of Möbius strip has been adopted in the creation of sculpture, exploration of idea for bridges and buildings. In this study, the possibility of adopting the form of Möbius strip as surface shape for tensioned fabric structure has been studied. The combination of shape and internal forces for the purpose of stiffness and strength is an important feature of tensioned fabric surface. For this purpose,form-finding needs to be carried out. In this study, nonlinear analysis method is used for form-finding analysis.The influence of non-orientable characteristic of Möbius strip on the modeling process using finite element procedures was investigated. Pattern of pre-stress in the resulting tensioned fabric surface is also studied.Form-finding has been found to converge for Möbius strip R/W 1.37 with initial assumed shape specified to follow the topology without opening which has been observed in experiment.

265 - 270

Authors: H.R. Tavakoli, M. Talebzadeh Amiri, G. Abdollahzade, A. Janalizade

The risk of earthquake ground motion parameters in seismic design of structures and Vulnerability and risk assessment of these structures against earthquake damage are important. The damages caused by the earthquake engineering and seismology of the social and economic consequences are assessed. This paper determined seismic hazard analysis in Babol via deterministic and probabilistic methods. Deterministic and probabilistic methods seem to be practical tools for mutual control of results and to overcome the weakness of approach alone. In the deterministic approach, the strong-motion parameters are estimated for the maximum credible earthquake, assumed to occur at the closest possible distance from the site of interest, without considering the likelihood of its occurrence during a specified exposure period. On the other hand, the probabilistic approach integrates the effects of all earthquakes expected to occur at different locations during a specified life period, with the associated uncertainties and randomness taken into account. The calculated bedrock horizontal and vertical peak ground acceleration (PGA) for different years return period of the study area are presented.

283 - 288

Authors: M. Hoseinzadeh, G.D. Najafpour, M.A. Beygi

This paper focuses on addition of fillers in epoxy resin and aggregate for polymer concrete (PC)preparation. For the preparation of PC, two kinds of fillers, i.e. rice husk ash and broom stem ash were used.According to experimental results, addition of fillers had a positive impact on the physical and mechanical properties of the PC. In the PC sample with rice husk ash, with the filler/aggregate ratio of 0.075 and 18.4%polymer, maximum compressive strength of 86.41 Mpa was obtained; while the compressive strength of the polymer concrete without filler was 71.2 Mpa. The PC sample with broom stem ash, with the filler/aggregate ratio of 0.12 and 23% polymer showed the maximum flexural strength.

294 - 298

Authors: Bassam A. Tayeh, B.H. Abu Bakar, M.A. Megat Johari, S.M. Tayeh

The deterioration of reinforced concrete structures is a major social problem. To minimize this problem and ensure effective structural management, the number and extent of repair interventions must be kept at the lowest probable level. Good bond is one of the main requirements for successful repair. The main aim of this study was to investigate the compressive stress-strain behaviour of the composite specimens consist of ordinary concrete (OC) substrate as old concrete and reactive powder concrete (RPC) as a retrofitting material,by using different types of OC substrate surface preparation methods. The results showed that the composite OC/RPC specimens were able to behave closely to individual OC, in the case of using OC substrate with surface prepared by sand blasted.

304 - 310

Authors: Mehdi Golestaneh, Ghasem Najafpour, Ghazaleh Amini, Morteza Beygi

Polymer concrete (PC) with suitable mechanical and chemical properties was prepared. The properties of PCs are dependent upon the type of resins and filler materials. This research paper presents an assessment of the chemical resistance of polymer concretes in various chemical compositions. Epoxy resin was used to fabricate PC samples. The sample blocks were exposed to hostile environment in strong acidic and alkali conditions. The loss of compressive strength of the samples exposed to corrosive environment was insignificant. The strength of corrosive environment had significant effect on the chemical resistance of the fabricated PC samples. A desired blend of the optimized chemical composition of epoxy was used and tested in all corrosive environments. These samples were successfully passed all the designed testing conditions.

77 - 85

Authors: Ali Eliassi, Hamid Modarress, Ali Reza Karimzadeh

In this study the effects of some different factors on ceria (CeO2) catalytic activity for ethanol steam reforming (ESR) to produce high H2/CO ratio were investigated. The considered factors were sonication time in three durations (0, 15 and 30 minutes), calcination temperature at three temperatures (500, 650 and 800°C), mole ratio of H2O/ethanol in three ratios (3, 5 and 8) and reactor temperature at three temperatures (300, 350 and 400°C). The Taguchi L9 experimental design method was used to investigate the effect of these parameters on maximization of H2/CO. To identify the catalyst characteristics XRD, SEM, EDS, BET and TGA analysis were done. It was established that a face centered cubic crystal forms of nano particles of CeO2 were formed. Also the obtained results showed that by increasing calcination temperature or reducing the sonication time, the nano particle size was increased. The reactor tests showed that the optimum conditions for maximization of H2/CO ratio were: sonication time zero, calcination temperature 800°C, H2O/ethanol ratio 3 and reactor temperature 300°C. The mole percent of H2 and CO in these conditions were 64.46 and 0.011%, respectively.

91 - 98

Authors: Moosa Balali Osia, Seyed Jamal Hosseinipour, Mohammad Bakhshi-Jooybari, Abdolhamid Gorgi

Fuel cell constitutes from different components, among which bipolar plates are the important and expensive part. Nowadays, the fabrication methods of bipolar plates are the main challenges in fuel cell technology. Among different methods, the fabrication of bipolar plates from metal forming processes is the best selection. Recently, hydroforming is one of these methods that are used in fabrication of these plates. On the other hand, there are different layouts of flow fields for various usages. These layouts can be categorized, in forming viewpoint, to two distinct groups; one of them is the simple group (e.g. serpentine or parallel flow fields) and the other is the complex group (e.g. pattern and pin type flow fields). This paper investigate on feasibility of a hybrid micro-manufacturing process to fabricate fuel cell metallic bipolar plates that consists of multi-array pin type flow field on a large surface area. First, several forming methods for formation of bipolar plates in the FEM software (ABAQUS 6.10) were simulated. Second, the best method for actual fabrication of metallic bipolar plates without any rupture or defect was hydroformed. The results indicated that the complex flow field metallic bipolar plates can be formed adequately using the combined hydroforming and stamping (sizing) processes.

104 - 109

Authors: Mehdi Mehrpooya, Samaneh Daviran

In this study, a photovoltaic-electrolyser-fuel cell system was considered and simulated. This hybrid system produces hydrogen in the daytime and stores it in the storage tank in order to supply the required energy for the peak period of demand. Dynamic behavior of the process components was analyzed under different conditions. Transient simulation represents performance of the components and the system. Results can be used for improving the component’s efficiency and optimizing component’s size. The results obtained in this work, consist of hourly values of hydrogen produced by electrolyser unit, generated fuel cell energy to cover the energy demand, generated PV energy, dynamic behavior of the PEM fuel cell and tank pressure level.

116 - 125

Authors: Alireza Yaghoubi, Sepideh Gheibi, Farschad Torabi

Polymer Electrolyte Membrane Fuel Cells (PEMFCs) are identified as the most important choice to replace internal combustion engines. But there is still a long way to reach this fact, and, in order to reach such a purpose, it is necessary to carry out many optimizations on these cells. One of the methods resulting in a deeper and better understanding of physical processes within the cells is simulation of physical governing equations on fuel cells. In this article, these governing equations are introduced and a system of equations is solved for a model.

130 - 135

Authors: Mehdi Nazari, Hassan Ghassemi, Mahmoud Ghiasi, Mesbah Sayehbani

The research explained in this paper was carried out to analyze and design a point absorber wave energy convertor for Assaluyeh coastal on Persian Gulf. The geographical conditions of this region have some local short waves which may be ideal to use this type of energy convertor. According to the collecting of wave data and using an optimized buoy, it is concluded that the adjustments on damping and natural frequency have more effect on average heave displacement. Therefore, by changing the shape of flat buoy to conical cylindrical, the drag coefficient that has direct effect on the damping of the buoy could be reduced. Regarding the length to diameter ratio of 1.7 for the selected buoy, changing its shape from flat cylinder to conical cylinder causes the drag coefficient to decrease by 50 %, which is followed by 20% increase in average amplitude of heave motion from 0.524-0.625m. This increase in average amplitude heave is efficacious in increase power buoy around 45 watts.

142 - 149

Authors: Hassan Hoveidi, Masumeh Ahmadi Pari, HosseinVahidi, Maryam Pazoki, Tahereh Koulaeian

Systematic industrial waste management is one of an important issue due to high environmental risks caused by improper waste disposal. Hence, present research was conducted to investigate environmental aspects of optimal disposal and management methods of industrial waste of Toos industrial estate in Mashhad. In this work, one of the environmental impact assessment methods called Rapid Impact Assessment Matrix (RIAM) was applied. Thus, various disposal options such as open dumping, sanitary landfill, gasification and incineration from the viewpoint of the physical, chemical, biological, ecological, cultural and social, economical and environmental aspects were evaluated. All of these aspects were compared due to selection of disposal methods through application of RIAM technique. The obtained results showed that sanitary landfill led to more beneficial effects than the other four mentioned options. Therefore, the best method of choice in compare to other options for waste management in the industrial estate of Toos, Mashhad was selected.

155 - 160

Authors: Ali Beheshti, Amirabbas Kamanbedast, Hossein Akbari

The Gotvand-Olya Dam is a rock-fill dam, located at Khuzestan province in southwest of Iran. Since the dam is subjected to the daily water level fluctuation, such as rapid drawdown and refill, thus induce a structural impact on the behavior of dam body, it draws many soil engineering concerns. In this paper, seepage analysis of the rock-fill dam was primarily conducted to evaluate the dam safety against the leakage through the dam body. Traditionally, steady-state analysis was employed to investigate the seepage in the dam body, summing that water level is fixed at two cases: high and low water levels. Consequently, it was not able to properly reflect the time-dependent characteristics of seepage phenomena. In this study, seepage analysis was numerically performed using 2-D FEM transient analysis. As a particular boundary condition for an analysis, the water level fluctuation was incorporated to simulate the daily changes. As a result, various seepage phenomena were quantified such as hydraulic gradient, seepage vector and pore water pressure distribution at the corresponding time of interest as the water level rises and recedes. At steady state analysis, the seepage flux at high water level in downstream area was predicted to be 78 l/s. In additions, the seepage flux measured and estimated were both acceptable considering design criteria. The result of this study proves that there is no sign of hazardous sources contributing to the possibility of piping, internal erosion and excess leakage through the dam body.

1 - 7

Authors: Ghodsi Mohammadi Ziarani, Alireza Badiei, Masoomeh Azizi, Parisa Gholamzadeh, Leila Seyedakbari

An efficient green and benign synthesis was developed in the one-pot three component Strecker reaction using heterogeneous nanoporous acid catalyst of SBA-Pr-SO3H with a pore size of 6 nm under solvent free condition. This method has the advantages of short reaction time, ease of the products isolation, excellent yields for the products.

17 - 23

Authors: Sanaz. Monemtabary, Mojtaba Shariati Niasar, Mohsen Jahanshahi, Ali Asghar Ghoreyshi

In this work, The adsorption of methane onto multi-walled carbon nanotubes (MWCNTs) was studied, in which the influences of temperatureand pressure were investigated. The physical properties of the MWCNT were systematically characterised by Scanning Electron Microscopy (SEM) and Brunauere-Emmette-Teller (BET) surface area measurements. The equilibrium adsorption data were analyzed using threecommon adsorption models: Langmuir, Freundlich and Sips. All of the models fit the experimental results well. The adsorption thermodynamic was carried out at 283.15, 298.15 and 313.15 K. The isosteric heat of adosrption( H) was calculated for CH4 and H2, using Claussius–Clapeyron equation. The small amounts of that indicated physical nature of adsorption mechanism.All values were negative, indicating that the adsorption is feasible and exothermic process in nature.

28 - 35

Authors: Mehdi Forouzani, Atefeh Abouzarzadeh, Nader Bahramifar, Mohsen Jahanshahi

In the presence of imprinting molecules of Nalidixic acid, uniformly sized molecularly imprinted polymers (MIPs) in nanometer range were synthesized. The MIPs were successfully prepared by precipitation polymerization using methacrylic acid (MAA) and methyl methacrylate (MMA) as functional monomers at different mole ratios. The effect of combination of MAA-to-MMA on the morphology, binding, recognition and release behaviors of the final particles were studied. The produced polymers were characterized by differential scanning calorimetry and their morphology was precisely examined by scanning electron microscopy. We obtained very uniform imprinted nanospheres with diameter of 120- 180 nm. Among the MIP nanospheres the MIPs using combination of MAA and MMA showed nanospheres with lowest mean diameter (120 nm) and the highest selectivity factor (9.7). The adsorption properties of Nalidixic acid in acetonitrile for imprinted nanospheres were evaluated by equilibrium rebinding experiments. Results from binding experiments proved that MIPs exhibit specific affinity to Nalidixic acid in contrast to control polymers and this performance was affected by pH of loading solution and. Moreover, release experiments showed the controlled release of Nalidixic acid in longtime period. The loaded Nalidixic acid was released from the imprinted nanospheres within the 140 h.

43 - 48

Authors: Asieh Dehghani Kiadehi, Mohsen Jahanshahi, Mohammadreza Mozdianfard, Gholamreza Vakili-Nezhaad

Some techniques have been developed to produce carbon nanotubes (CNTs) in sizeable quantities, including arc discharge, laser ablation and chemical vapor deposition (CVD). Arc discharge in liquid environment is a new, simple and cheap method of synthesizing CNTs. CNTs in this study were fabricated by arc discharge in liquid. The present work was undertaken to study the effect of electrical conductivity of liquid on CNTs production and was fabricated using arc discharge between two graphite electrodes submerged in different aqueous solutions of NaCl, KCl and LiCl. For comparative study, CNTs were synthesized under different electrical conductivity conditions and the results were analyzed, compared and discussed. The scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy were employed to study the morphology of these carbon nanostructures. Based on LiCl 0.25 N, high-crystalline and a longed multi MWCNTs, SWCNTs were synthesized by using this technique.

53 - 59

Authors: Razieh Jabari seresht, Mohsen Jahanshahi, Ali Morad Rashidi, Ali Asghar Ghoreyshi

Thermally-reduced graphene was obtained from reduction of graphene oxide (GO) via heat treatment under the hydrogen in the range of 300-1100°C. In order to find optimum tempreture, the synthesized graphene has been investigated by X-ray diffraction (XRD), FTIR spectroscopy as well as Raman spectroscopy. The result indicated that the reduced graphene at 900°C (GR900) had the highest quality in comparison with the other temperatures. Additionally, GR900 exhibited a sharp (002) peak corresponding to an interlayer distance of 3.39° A, which is close to that of conventional graphene (3.4°A). However, the structure of GR900 was also investigated by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and the results supported the previous findings.

68 - 72

Authors: Yadollah Batebi, Alireza Mirzagoltabar, Seyed Mostafa Shabanian, Sara Fateri

Basically most of cement based mixtures are likely shrinking. Use of fibers is not a new idea in this case. Previously, there were some evidences that horse hair, straw and cotton fibers were used in mud and mortars in ancient times. Then, utilizing these fibers in concrete mixture may increase concrete workability and decrease shrinkage cracks. Due to nano cross-section of hair and its proper tensile strength this project investigates its application to reduce the shrinkage of concrete mixtures. For this purpose, human hair fibers were used in 0.4 and 0.8 and 1.2 weight percent and the length of the fibers in each case varied between 15 and 60 millimeter and the samples were made of dimensions of 40×40×160 millimeters. Results are shown as considerable amount of hair may reduce in the shrinkage in the hair reinforced concrete.