bluuebunny/crossref_metadata_2025 huggingface dataset:
Assisting People with Multiple Disabilities to Improve Computer Typing Efficiency through a Mouse Wheel and On-Screen Keyboard Software
Authors: Shih Ching Hsiang , Chang Man Ling , Huang Ju Pien , Lin Yi Chieh
Published: November 2013

This study aims to find out if the two students with multiple disabilities can learn to use standard keyboard and computer mouse with the intervention of newly developed software. With built-in On-Screen Keyboard (OSK), the user can key in commands by using a standard mouse. Without changing the conventional computer mouse and outward appearance, a new mouse driver program was designed, of which the scroll wheel became a key to quickly click on OSK. With this design, students with multiple disabilities can complete the task fast and correctly by sliding the mouse wheel.
Anaglyph 3D Display Based on a Computational Stereo System
Authors: Wang Meng , Chen Jian Sheng , Yang Chang , Cao Ke Ming , Su Guang Da
Published: November 2013

Anaglyph 3D is a low-cost and popular 3D display method, made out of a photo pair. With only one common camera, however, there are difficulties in capturing moving objects. We suggest using the light field camera, which can be exploited as a computational stereo rig, to capture image pairs simultaneously. A processing framework for making anaglyph 3D image is then proposed. The effectiveness of our proposal is verified visually by experiments.
Synthesis of Nano Alumina by a Novel Combustion Method
Authors: Elahipanah Navid , Heshmati-Manesh Saeed
Published: November 2013

nano Al2O3 powders have been synthesized by a solution combustion method (SCS) using glycine as a fuel and ammonium nitrate as an extra oxidizer. The effectiveness and influence of oxidizer/fuel ratio and the water contetnt of the solution on the crystallite size and characteristics of alumina particles was investigated respectively. As-synthesized powders were γ-alumina due to calcination of samples at 900 ̊C for 2 hours. Also, Results demonstrated that the alumina nanoparticles obtained from φ=1.8 had crystallite sizes around 65 nm which is less than other values of φ, due to evolution of larg amounts of gases which inhibits grain growth and less adiabatic temperature during the process. Also, it was concluded that the more the water content of the solution, the less the crystallinity and crystallite sizes of the products as a result of decreased adiacatic temperature.
Study on the Wear Behavior of Ultrafine Grained 304L Stainless Steel
Authors: Nafar Dehsorkhi Reyhane , Sabooni Soheil , Karimzadeh Fathallah , Rezaeian Ahmad , Enayati Mohammad Hossein
Published: November 2013

An ultrafine grained 304L stainless steel with average grain size of 650±100 nm was produced by a combination of cold rolling and annealing. Wear behavior of the steel was examined by dry sliding wear tests under different loads. Different microstructural characterizations were conducted on the ultrafine grained structure after thermomechanical processing and wear tests. The results demonstrated that the steel had yield strength of 720 MPa and total elongation of 47%, which is almost twice higher than typical coarse grained strength. Also, wear tests results showed a good linear relation between the cumulative wear loss and distance in each normal load. Wear rate was about 0.024, 0.043 and 0.093 mg/m for normal loads of 10, 20 and 30N, respectively. Wear mechanism was also recognized as delamination (in the early stage) and mixture of delamination and abrasion in higher distances.
A Mimetic Amorphous Active Carbon Model Using Molecular Dynamics Simulation
Authors: Farhadian Nafiseh
Published: November 2013

Porous carbons are disordered materials with applications in many areas such as catalysis, molecular separation, and energy storage/conversion. Among porous materials, active carbons are the most popular materials in separation processes. They are non-crystalline materials with heterogeneous pore structures. This property does not permit accurate structural determinations by diffraction techniques. Thus only limited structural information can be extracted from experimental techniques. Consequently, a molecular model of nanoporous carbon can't be constructed that is based solely on experimental data. Computer simulation techniques provide an alternative way to tackle this problem. So, in this study, the synthesis process of an amorphous active carbon is investigated using molecular dynamics simulation. Simulations are carried out at constant temperature in the box containing specific numbers of pure carbon sheets. Two different types of ensembles have been used for simulation includingNPTandNVT. Calculated results show that the final structure of porous carbons is in agreement with SEM images of some commercial active carbons. Also, results indicate that the final structure is consisted of three different pore size (r) zones: r<2 nm which produces micro pores,250 nm which named macro pores. These observations are exactly the same as what is observed in experiments. These various pore sizes especially micro and meso pores are observed in radial distribution function curve, too. At last, the temperature effect on the pore size is investigated. Three different temperatures of 973K, 1073 K and 1173 K are applied for the simulation. Calculated results show that increasing the temperature does not have any significant effects on the pore size and structure.
Simulation of a Gas Electron Multiplier Detector for Hard X-Ray Imaging with a Novel Nano Converter
Authors: Edalatkhah Elham , Saramad Shahyar , Sheibani Shahab
Published: November 2013

One of the most marvelous applications of GEM is hard X-ray imaging. For increasing the detection efficiency, a photoconverter is usually required. In this work a novel nanostructure photo converter is proposed. Simulation results show that the combination of fast position sensitive gas detector with nanophoto converter can be improved the detection efficiency by one order of magnitude in comparison to the bulk one, which is more benefic for hard X-ray medical imaging applications.
Synthesize and Characterization of Hollow Hydroxyapatite Nanopowders with Different Morphologies: Role of Cationic and Non-Ionic Surfactants
Authors: Seyfoori Amir , Hosseini Hamideh Mahmoodzadeh , Imani Fooladi Abbas Ali , Nourani Mohammad Reza
Published: November 2013

Today, hydroxyapatite hollow nanopowders have attracted the attention of researchers as a reliable option for drug and protein delivery systems. In this study, nanohydroxyapatite powders with different morphologies were successfully synthesized via wet chemical precipitation method. Elongated rice-shape and semi-spherical nanopowders with hollow structures were synthesized using CTAB and the mixture of cetyltrimethylammonium bromide (CTAB) and polyethylene glycol (PEG) as surfactants respectively. The properties of these nanopowders were charecterized by means of scanning electron microscopy, x-ray diffraction, fourier transform infrared spectroscopy and nitrogen adsorption experiments. The results showed that using CTAB as a surfactant not only can alter the morphology of the HAp nanopowders but also it can have a significant effect on the structure of them, so that by using CTAB and mixture of CTAB and PEG, nanoporous HAp nanopowders were acquired. Moreover, the analysis of nitrogen adsorption showed a higher average surface area for CTAB synthesized HAp in comparison to CTAB/PEG synthesized nanopowder. The amount of live cells adjacent to the HAp suspensions in PBS (50, 100, 200 mg/L) was evaluated by MTT experiment. The results of MTT assay showed the ascending cell proliferation trend for spherical nanopowders by an increment in suspension concentration, while this trend was descending for rice-shape nanopwders.
Evaluating the Effects of Different Plasticizers on Mechanical Properties of Starch/ Clay Nanocomposites
Authors: Sherafati Marjan , Mousavi Seyed Mohammad A. , Emam-Djomeh Zahra , Bagheri Reza
Published: November 2013

nanobiocomposites are a new class of hybrid materials composed of nanosized filler (nanofiller) incorporated into a bio-based matrix. Such an association between eco-friendly biopolymers and nanoobjects, with the aim to obtain synergic effects, is one of the most innovating routes to enhance the properties of these bio-matrices. In recent years, there has been an increasing interest in Starch as an inexpensive and renewable source has been used as a filler for environmentally friendly plastics for about two decades. However, the poor mechanical properties of starch based biopolymers, leads to use of nanoparticles as reinforcing materials. In the present study, the influence of a combination of a novel plasticizer (formamide) and a traditional plasticizer (glycerol) on the mechanical characteristic of the TPS (thermoplastic starch)-nanoclay compounds has been investigated and the results were compared with thermoplastic starches plasticized by glycerol only. The biodegradable nanocomposites were produced via melt extrusion processing and the samples for mechanical properties were originated by injection molding. The tests performed after two weeks keeping the samples in polyethylene bags. In this study, tensile strength, elongation at break and Young's Modulus were evaluated. Furthermore, the morphologies of samples were studied using a transmission optical microscope. This research showed that using a combination of glycerol and formamide reduce the Young's Modulus and improve the flexibility which can be useful in some applications.
Evaluating the Flow Properties of Ultrafine-Grained Materials
Authors: Kawasaki Megumi , Langdon Terence G.
Published: November 2013

Processing through the application of severe plastic deformation (SPD) provides an opportunity for achieving significant grain refinement, typically to the submicrometer or even the nanometer level. If these small grains are reasonably stable at elevated temperatures, it is possible to achieve excellent superplastic capabilities at very rapid strain rates. Recent developments on the flow properties of ultrafine-grained materials are examined and it is shown that the flow mechanisms can be readily depicted using deformation mechanism maps. Examples of maps are presented for materials processed by SPD techniques.
In Vivo and In Vitro Evaluation of Poly(lactide-co-glycolide)/Bioactive Glass Nanocomposite Coating
Authors: Mehdikhani-Nahrkhalaji Mehdi , Fathi Mohammad Hossein , Mortazavi Vajihesadat , Mousavi Sayed Behrouz , Hashemi-Beni Batool , Razavi Sayed Mohammad , Akhavan Ali , Haghighat Abbas
Published: November 2013

The aim of this study was to evaluate the interaction of bioactive and biodegradable poly (lactide-co-glycolide)/bioactive glass (PBG) nanocomposite coating with bone and human adipose-derived stem cells (hASC) in vivo and in vitro, respectively. Sol-gel derived 58S bioactive glass (BG) nanoparticles and 50/50wt% poly (lactic acid)/poly (glycolic acid) (PLGA) were used to prepare the coating. The nanocomposite coating was characterized by SEM, XRD, and AFM. Mechanical stability of the prepared nanocomposite coating was studied during intramed­ullary implantation of coated Kirschner wires (k-wires) into rabbit tibiae. Titanium mini-screws coated with PBG nanocompoite coating was implanted intramedullary in rabbit tibia. Bone tissue interaction with the prapared nanocomposite coating was evaluated 30 and 60 days after surgery. The effect of PBG nanocomposite coating on the attachment and viability of human adipose-derived stem cells (hASCs) was investigated. Results showed that PBG nanocomposite coating remained stable on the K-wires with a minimum of 96% of the original coating mass. Tissue around the coated implants showed no adverse reactions to the coating. Woven and trabecular bone formation were observed around the coated samples with a minimum inflammatory reaction. The hASCs showed excellent attachment and viability on the PBG nanocomposite coating. It was concluded that PBG nanocomposite coating provides an ideal surface for bone formation and stem cells attachment and it could be used as a candidate for coating the dental and orthopedic implants.
Fabrication of CoFe/BaFe12O19 Magnetic Nanocomposite Thin Films by Electrodeposition
Authors: Khameneh Soheila Kharratian , Sohi M. Heydarzadeh , Ataie Abolghasem , Mehrizi Saeed
Published: November 2013

A study of the incorporation of barium hexaferrite nanoparticles into a CoFe matrix by means of electrodeposition over brass substrates has been performed. Barium hexaferrite nanoparticles were prepared by co-precipitation route using solution of iron and barium nitrates with a Fe3+/Ba2+molar ratio of 8, by addition of NaOH with a OH-/NO3- molar ratio of 2. X-ray diffraction (XRD) results indicated that in a sample synthesized from aqueous solution and annealed at 900 °C for 1 hour, BaFe12O19 was the dominant phase. Field emission scanning electron microscopy (FE-SEM) showed plate-like particles of barium hexaferrite by mean diameter of 300 nm and thickness of 45 nm. CoFe-BaFe12O19 nanocomposite thin films were then electrodeposited froma Co-Fe bath containing the barium hexaferrite particles obtained in the first stage of this work. Finally, FE-SEM equipped with energy dispersive spectroscopy (EDS) analyzer and XRD analysis was applied on the deposited films, to confirm presence of the nanoparticles in the film. The average crystallite size of the deposits was around 30 nm. It was also noticed that increasing the concentration of the particles in the electroplating bath, caused a rise in the BaFe12O19 content of the deposits but had no significant effect on the composition of the CoFe matrix.
Sintering Characterizations of Ag-Nano Film on Silicon Substrate
Authors: Keikhaie Mahdi , Akbari Javad , Movahhedi Mohammad Reza , Alemohammad Hamidreza
Published: November 2013

Nowadays, thin films have many applications in every field. So, in order to improve the performance of thin film devices, it is necessary to characterize their mechanical as well as electrical properties. In this research work we focus on the development of a model for the analysis of the mechanical and electrical properties of silver nanoparticles deposited on silicon substrates. The model consists of inter-particle diffusion modeling and finite element analysis. In this study, through the simulation of the sintering process, it is shown that how the geometry, density, and electrical resistance of the thin film layer are changed with sintering conditions. The model is also used to approximate the values of the film Youngs modulus. Comparing results with experimental results shows the high accuracy of this approach.
The Effect of Process Parameters on Pulsed Nd:YAG Laser Welding of Inconel 625
Authors: Ramezani Hadi , Akbari Mousavi Seyed Ali Asghar , Ebrahimzadeh Hossein
Published: November 2013

The bead on plate welding specimens with the 1mm thickness was fabricated by Nd:YAG pulsed laser SW-1 . The effects of laser process parameters on the weld dimensions, metallurgical and mechanical properties of weld metal were investigated. The results showed that both weld depth and weld width increase with voltage. Unlike base metal that has coaxial grain structure, weld metal is composed of a dendritic structure. Grain growth in the heat affected zone did not occur. However, ultrafine precipitations were deposited at the HAZ which their size was approximately between 500 nm to microns. All tensile specimens failed in the fusion zone.
Electrolytic Coloring of Anodized Aluminum by Copper
Authors: Nozari Nezhad Masume , Kolahi Alireza , Kazemzad Mahmood , Saiedifar Maryam
Published: November 2013

It is important to generate aluminum oxide layer on the surface of aluminum in order to enhance the adhesion of the dye molecules in coloring aluminum industry. One of the major advantages of aluminum is the formation of a resistant oxide layer naturally, but the thickness of this layer is not high enough and it should be damaged due to lack of mechanical strength. However, the thickness of oxide layer can be increased through anodizing; this process improves its abrasion and corrosion resistance as well as its mechanical properties. In the present study, specimens of pure aluminum were anodized under galvanostatic condition in sulfuric acid electrolyte and porous nanostructured aluminum oxide layer was formed. Porosity of the anodized layer was controlled by optimizing the working conditions such as electrolyte concentration, anodizing time and current density. Finally, the specimens were electrolytically colored by applying alternating current to copper (Cu) solutions. Colored coatings were created at constant voltage and different coloring duration. The results indicated that the shade of different metal ions can be optimized by controlling the coloring parameters, the longer time of coloring results in the darker colors. The samples were examined by X-Ray Diffraction (XRD) spectroscopy and Scanning Electron Microscopy (SEM) and electrochemical test.
Effect of Rubber Modification on the Morphology and Properties of Novolac Nanostructures
Authors: Hajizadeh Alireza , Bahramian Ahmad Reza , Sharif Alireza
Published: November 2013

Nanostructured organic materials have received considerable attention over the past decade. This nanostructure is responsible for their unusual acoustic, thermal, and mechanical properties. One of the most studying of this field is sol-gel polymerization of resorcinol-formaldehyde, followed by organic solvent exchange, supercritical drying. However, the conventional process involves long gelation time, expensive monomer of resorcinol, high cost of supercritical drying device and so on, which makes it some distance away from being promoted to commercial production. In this work, to reduce cost and time, the reaction of novolac resin and hexamine and ambient pressure drying method was used for preparation and drying of organic gel. To reduce time, the polymerization in saturated atmosphere of solvent vapor instead of conventional sol-gel polymerization presented. These nanostructure materials have a nanoporous structure that constructed by colloidal like particles gathered up in filament-shaped. Because of this nanoporosity and structure, these materials have very low fracture energy and could including them as brittle materials. The goal of this research produces these nanostructure materials using novel method and enhances fractural resistance. To gain this proposes, the feasibility of using acrylonitrilebutadiene rubbers (NBR) has been investigated. For studying of morphology and properties of this structure, we used SEM, FTIR and porosimetry analysis. The results shows that the addition of 0.5, 1 and 2 wt% NBR to Novolac nanostructure increased density and decrease the pore volume and pore size.
Effect of Pulse Electrodeposition on Properties of Nanocrystalline Nickel Coatings
Authors: Sanaeian Mohammad Reza , Nasirpouri Farzad
Published: November 2013

In this work, nanocrystalline nickel coatings were electrodeposited from a Watts bath using direct (DC) and pulsed (PC) current. Effect of deposition conditions on the morphology, hardness, grain size, surface roughness and corrosion resistance of nickel coatings were investigated. Ni films deposited by PC method exhibited greater hardness values and smaller crystallite size compared to those deposited by DC method. A preferential crystallographic orientation or texture was found in the nickel films depending upon the electrodeposition pulse shape, as it is polycrystalline in the DC electrodeposited films, while exhibit <111> crystallographic growth direction for PC method. Corrosion evaluation results showed that the PC electrodeposited nanocrystalline Ni films have higher corrosion resistant compared to those deposited with the DC method in 2 mol/liter NaOH solution.
The Synthesis of Graphene Sheets Using Sodium Dodecyl Sulfate (SDS) as a Surfactant; An Electrochemical Process
Authors: Moradi Mina , Aghazadeh Jamshid , Mansouri Tehrani Aria
Published: November 2013

In this work a simple electrochemical approach was performed for the production of graphene sheet. SDS was used as a surfactant. Raman spectroscopy proved the existence of graphene and the quality of the product was further verified. The morphology of the graphene sheets were analyzed with scanning field emission electron microscope, indicating the crumpled nature of graphene sheets. In addition, atomic force microscopy was employed to determine the thickness of the graphene sheets which varied from monolayer graphene to the stack of a few graphene sheets. The current versus time graph indicated the possibility of achieving a higher exfoliation rate by applying higher voltages.
A Study on Electrospun Nanofibrous Mats for Local Antibiotic Delivery
Authors: Maleki Mahboubeh , Amani-Tehran Mohammad , Latifi Masoud , Mathur Sanjay
Published: November 2013

The demand for novel antibiotic-loaded electrospun nanofibrous structures has increased extremely in the recent years and has engaged the interests of scientists and engineers into a blend configuration of antibiotic drug and biocompatible polymers due to their unique applications in future of better therapeutic effect, reduced toxicity and sustained local antibiotic release over a period of time. One method to produce these antibiotic-loaded networks is by electrospinning process. However, it is very important to know structural characteristics and morphology of nanofibers for controlling the performance of the yields. In this paper, fabrication of electrospun nanofibers suited for antibiotic delivery system is investigated based on tetracycline hydrochloride as the antibiotic drug and poly (lactic-co-glycolic acid) as the biodegradable polymeric matrix. Furthermore, the effect of material and process parameters on morphology and release behavior of produced nonwovens is investigated. The efficacy of the medicated scaffolds using a static system for bacterial growth on agar plates was also proved.
Preparation of Cellulose Nanofibrils by High-Pressure Homogenizer and Zein Composite Films
Authors: Shakeri Alireza , Radmanesh Sattar
Published: November 2013

Cellulose nanofibrils ( NF ) have several advantages such as biodegradability and safety toward human health. Zein is a biodegradable polymer with potential use in food packaging applications. It appears that polymer nanocomposites are one of the most promising applications of zein films. Cellulose NF were prepared from starting material Microcrystalline cellulose (MCC) by an application of a high-pressure homogenizer at 20,000 psi and treatment consisting of 15 passes. Methods such as atomic force microscopy were used for confirmation of nanoscale size production of cellulose. The average diameter 45 nm were observed. Zeincellulose NF nanocomposite films were prepared by casting ethanol suspensions of Zein with different amounts of cellulose NF in the 0% to 5%wt. The nanocomposites were characterized by using Fourier transform infrared spectroscopy ( FTIR ), Atomic force microscopy ( AFM ) and X-ray diffraction ( XRD ) analysis. From the FTIR spectra the various groups present in the Zein blend were monitored. The homogeneity, morphology and crystallinity of the blends were ascertained from the AFM and XRD data, respectively. The thermal resistant of the zein nanocomposite films improved as the nanocellulose content increased. These obtained materials are transparent, flexible and present significantly better physical properties than the corresponding unfilled Zein films.
Synthesis of Co/TiO2 Nanocomposite and its Use in Construction of a Sensitive and Selective Sensor for Determination of Ciprofloxacin
Authors: Shamsipur Mojtaba , Gholivand Mohammad Bagher , Dehdashtian Sara , Feyzi Mostafa , Jafari Fataneh
Published: November 2013

The Co/TiO2 nanocomposite was synthesized by a modified sol-gel method. The surface structure and composition of nanoparticles were characterized by scanning electron microscopy (SEM), X-ray powder diffraction analysis (XRD), Fourier transform infrared (FTIR) spectrometry, thermal gravimetric analysis (TGA) and N2 physisorption. A carbon paste electrode (CPE) modified with Co/TiO2 nanocomposite was prepared and used for low level determination of antibiotic ciprofloxacin (CF) using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Under optimized conditions, the modified electrode exhibited a linear response over the concentration range of 0.1 to 70 μM CF, with a detection limit of 0.03 μM. The proposed sensor was applied to the CF determination in serum and urine samples.
Emulsion Technique to Synthesize Polystyrene Incorporated with Surface Modified and Unmodified Nano-TiO2 Particles
Authors: Mirzababaei Mahdi , Behniafar Hossein , Hashemimoghadam Hamid
Published: November 2013

In the present work, we have focused on the synthesis and characterization of Polystyrene (PS) nanocomposites incorporated with anatase-TiO2. The nanoTiO2particles were used in two forms including surface modified (mod TiO2) and surface unmodified (unmod TiO2). Accordingly, two PS/TiO2nanocomposites were synthesized, i.e. (PS/mod TiO2) and (PS/unmod TiO2), starting from styrene monomer in the presence of sodium dodecylsulfate (SDS) emulsifier. 4,4-Methylene diphenyldiisocyanate (4,4-MDI) was used for the surface modification of the nanoTiO2particles via urethanation reaction with terminal OH groups. After modification, optical behavior of the samples was determined. The chemical structure of pure polystyrene (pure-PS), (mod TiO2), (PS/mod TiO2), and (PS/unmod TiO2) was confirmed by FT-IR spectroscopy. X-ray diffraction (XRD) analyses obviously showed the broad peak related to the (pure-PS) centered at 2θ of 20 ° as well as the sharp characteristic peak of the TiO2nanoparticles appeared at about 2θ of 25 °. Moreover, diffuse reflectance UV/vis spectroscopy analyses, (mod TiO2) and (PS/mod TiO2) samples showed strong visible absorption at the range of 400 to 600 nm.
Synthesis of Magnetic Nanocomposite Fe3O4 Coated Polypyrrole (PPy) for Chromium(VI) Removal
Authors: Mirrezaie Najmeh , Nikazar Manochehr , Hasan Zadeh Mehrdad
Published: November 2013

In recent years there is a continuously increasing worldwide concern for the growth of wastewater treatment technologies. The utilization of iron-oxide nanomaterials has attracted much interest due to their unique properties, such as extremely small size, high surface-area-to-volume ratio, surface modifiability, excellent magnetic properties and great biocompatibility. In this study, Fe3O4 coated polypyrrole (PPy) magnetic nanocomposite was prepared via in situ polymerization of pyrrole monomer for the removal of highly toxic Cr (VI).The PPy/Fe3O4 nanocomposite was characterized by field-emission scanning electron microscopy (FE-SEM), X-ray diffraction pattern (XRD) and Fourier-transformed infrared spectroscopy (FTIR). The adsorption properties of the PPy/ Fe3O4 nanocomposite for the removal of Cr (VI) were thoroughly studied. Up to 99% adsorption was found with 220 mg/L Cr (VI) aqueous solution at pH 2. Adsorption results showed that Cr (VI) removal efficiency by the nanocomposite decreased with an increase in pH. Adsorption kinetic was best described by the Pseudo-second-order rate model. Desorption experiment showed that in spite of the very poor recovery of the adsorbed Cr (VI); the regenerated adsorbent can be reused efficiently at least for two successive adsorptiondesorption-cycles without significant loss of its initial capacity.
Production of Nanostructured Ni-Ti-Ag Alloy by Mechanical Alloying
Authors: Rostami Abbas , Sadrnezhaad Seyyed Khatiboleslam , Bagheri Gholam Ali
Published: November 2013

Because of corrosion resistance and antibacterial effects, shape memory Ni-Ti-Ag alloy can be considered for different biomedical applications. Mechanical alloying is used to produce nanostructured Ni-Ti-Ag alloy from elemental powders. X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) are used to characterize the product. Results show that after 1h milling, homogenous distribution of the elements occurs; while no intermetallic compounds is observed. After 3h milling, titanium dissolves in nickel to form amorphous and nanostructured solid phases. Peaks of B2 phase appear in the XRD pattern after the 3h milling of the powder mixture. Sintering of the 3h-milled mixture at 1223 K leads to the formation of NiTi intermetallic compound; while titanium disappears, the content of the element nickel reduces and grain growth takes place.
Fabrication of Nanostructure Ferrite Foam
Authors: Emamian Hamid Reza , Honarbakhsh-Raouf Abbas , Ataie Abolghasem , Mirzaee Omid , Bafti Hasan
Published: November 2013

In this work, cobalt ferrite nanopowder was synthesized by Pechini type sol-gel method based on polyesterification reaction between citric acid, ethylene glycol and benzoic acid. Single phase cobalt ferrite nanopowders including 80 nm mean particle sizes were achieved after calcination treatment at 750ͦC for 1 hour. Obtained powder was subjected to fabrication a foam using pure urea as a spacer material. Pure urea with desired particle size was mixed by ferrite powder with 50-60 volume percentages and appropriate amounts of ethanol and wax. The mixture was molded in a steel die and compacted by one direction hydraulic press to achieve a disk with 1cm diameter and 1cm height. Green compacted disk was sintered under controlled heating rate condition from room temperature to 1000ͦC prohibition of foam structure collapse. XRD, SEM analysis results proved the formation of open cell foam having nanostructured pore wall. The samples proceeding survey demonstrated that the key factors through foam processing by this route are applied force at compact step and heating rate at sinter step. Moreover using the nanopowder let loading more amounts of spacer, also lead to decrease of inhomogeneity pore distribution, which are considerable characteristic in foam structures.
An Investigation of Solvent Effect on Rhombohedral/Monoclinic/Tetragonal Phase Properties of Pb(Zr0.53Ti0.47)O3 Nanoparticles Prepared via Sol-Gel Method
Authors: Shakeri Amid , Abdizadeh Hossein , Golobostanfard Mohammad Reza
Published: November 2013

The highest piezoelectric and ferroelectric properties of lead zirconate titanate (PZT) occur in vicinity of morphotropic phase boundary (MPB). In MPB, crystalline phase ratios play a crucial role in determining the dielectric properties. In this paper, PZT nanoparticles were synthesized by a modified sol gel procedure and the effects of different solvents of methanol, ethanol, 1-propanol, and acetic acid on tetragonal, rhombohedral, and monoclinic phase ratios near the Pb (Zr0.53Ti0.47)O3 were investigated. The X-ray diffraction results show the formation of almost pure perovskite structure in all samples. The volume fraction of tetragonal and rhombohedral phases, lattice constants, and lattice distortion were measured from the X-ray diffraction and Raman spectroscopic analysis for each solvent. Also, the domain size was compared between the solvents. A trace amount of monoclinic phase could be detected by Raman spectroscopy. The results show that acetic acid is the most appropriate solvent for synthesizing of PZT nanoparticles in which the tetragonal lattice parameters are ct=4.16 Ǻ and at=4.02 Ǻ with a distortion of 3%. The tetragonal volume fraction is estimated about 77%. The particle size and degree of agglomeration were measured according to field emission electron microscopy and indicates that 70 nm particles were formed for acid-based sample.
Effect of Barrier Layer on Fabrication of FePt Nanowires by Electrodeposition into Nanoporous Alumina Templates
Authors: Ilkhchy Ali Fardi , Nasirpouri Farzad
Published: November 2013

It is well known that the nanoporous aluminum oxide film is an electrical insulator. In addition the homogeneity of electrodeposited nanowire arrays in nanoporous alumina templates increases drastically with the usage of AC electrodeposition in comparison to DC electrodeposition. This is revealing of the effect of dielectric properties of alumina that is used as template for electrodeposition. In this work integrated nanowire arrays of FePt alloys were successfully fabricated by alternating current electrodeposition on nanoporous alumina; also we characterize the nanoporous alumina membrane that is used as a template for FePt nanowire electrodeposition using EIS allowing the electrochemical impedance contributions from the barrier layer, nanoporous structure, and electrolyte solution resistance to be calculated through the use of an equivalent circuit model. The impedance spectra of the porous film prepared under different anodization conditions were measured. The data is attained at open circuit potential over a frequency range between 1 Hz to 100 KHz with an AC potential amplitude of 10 mV. As our result demonstrates the resistance of the bariyer layer decreases with the anodization temperature then the electrochemical process of FePt nanowires at template which fabricated on low anodization temperature will be difficult due to the higher resistance.
An Investigation on Magnetic Interacting La0.6Sr0.4MnO3 Nanoparticles
Authors: Ehsani Mohammad Hoseein , Kameli Parviz , Ghazi Mohammad Ebrahim , Razavi Fereidon Saadat
Published: November 2013

Nanoparticles of La0.6Sr0.4MnO3 (LSMO) with an equivalent average particle size of ~ 20nm were synthesized by nitrate-complex auto-ignition method. The structural and magnetic properties were investigated systematically. The X-Ray diffraction study coupled with the Rietveld refinement of XRD data showed that sample crystallize in a rhombohedral structure with space group of R-3C. The stretching and bending modes in Fourier transform infrared (FTIR) spectroscopy is observed which indicates the formation of the perovskite structure of LSMO. The nature of DC magnetization versus field M(H) plot for sample resembles qualitatively with ferromagnetic (FM) systems. The AC-susceptibility data obtained at different frequencies confirmed the presence of a frequencydependent freezing temperature around room temperature. Based on the interparticle interaction strength and phenomenological models (Neel-Brown, Vogel-Fulcher and Critical slowing down) the magnetic dynamic behavior of nanoparticles was characterized. By fitting the experimental data with mentioned models the possibility existence of superparamagnetic/spin glass states were considered. The obtained values from fitting performance showed that there is a strong interaction between magnetic nanoparticles of LSMO.
Characterization and Mechanical Properties of PM Fe-Cu/SiCp Alloys
Authors: Öksüz Kerim Emre , Gün Tarık , Şi̇mşi̇r Mehmet
Published: November 2013

FeCuCo alloys are the new generation of metal matrix for diamonds in PM processed cutting tools. These alloys were created with the purpose of reducing the cobalt content in diamond tools. Nevertheless, little have been published, once this is a matter of industrial interest. In this work, samples of Fe (10-20) wt. %Cu and Fe (10-20) wt. %Cu 1%wt SiCp alloys were processed by cold pressing at 350 MPa, followed by sintering at 1150 C/30 min. under argon atmosphere. After sintering, a study of structural and microstructural analyses was conducted. Brinell hardness and wear tests were carried out in the metal matrix, as well as the wear resistance of the metal matrix composites. The composition Fe-20%wt Cu-1%wt SiCp was the best among the studied ones, because it presented the best results of hardness and wear resistance.
Manipulating the Structure and Morphology of Cobalt-Boron Nanoparticles through a Chemical Approach
Authors: Sabarou Hooman , Ataie Abolghasem
Published: November 2013

Cobalt-boron nanoparticles have been synthesized by a chemical reaction between NaBH4 and CoCl2.6H2O through manipulating pH value of the reaction mixture. The morphology, structure, phase composition, and thermal behavior have been examined via FESEM, TEM, XRD, EDS, and DSC techniques, respectively. It is demonstrated that the morphology and structure of ultimate nanoparticles completely depends on the pH value of reaction mixture. While the neutral pH value favors the smallest nanoparticles with a mean particle size of 50 nm and complete amorphous structure, the acidic condition promotes the growth process and the crystal structure. Furthermore, these nanoparticles transform into cobalt nanocrystallites after heated at 600°C, and retained the discrepancies in the morphology and the structure of the parent cobalt-boron nanoparticles. A detailed characterization of the nanoparticulates, discussions on the synthesis mechanism, and subsequent formation transformation have been provided.
Study the Effect of Nanoemissive Materials on M-Type Cathode Performance
Authors: Chaharsoughi Mina Shiran , Hadianfard Mohammad Jafar , Shiezadeh Mohammad Mahdi
Published: November 2013

In this study, the stoichiometric mixture of barium carbonate, calcium carbonate, and aluminum oxide with ratio of 5:3:2 was produced by two individual methods: sol-gel combustion and ball-milling method used as a precursor of electron emissive material on impregnated cathodes which make up high power vacuum microwave tubes such as klystrons. Results from X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray spectroscopy on emissive material produced by sol-gel combustion technique show that its crystallite size is under 45 nm, and particle size is less than 100 nm, and the chemical composition of emissive material is uniform at nanoscale. The effects of two types of emissive materials on operation properties of M type cathode were also investigated. The two types of manufactured M cathodes were tested inside an electron gun under maximum anode voltage 10.5 kV in continues wave mode, at 1100 ͦC, and the anode-cathode distance was fixed at 5 mm. results show that the emission current of M cathode impregnated by nano emissive materials is more uniform than conventional cathode, and its current density is about 2.7 A/cm2, while in I-V curve it does not reach at saturated-emission region at 10.5 kV.
The Phonon Confinement Effect on the Impurity States in Cylindrical Nanowire with a Finite Confining Potential in Presence of Electric and Magnetic Fields
Authors: Yeranosyan Mkrtich A. , Shahbandari Abbas Ghouchani , Vartanian Arshak L.
Published: November 2013

In the framework of effective mass approximation, the LandauPekar variational procedure is adopted to study the ground-state binding energy of a hydrogenic impurity in a semiconductor nanowire with finite confining potential subjected to both external fields (electric and magnetic) and electronpolar optical phonon interaction taking into account the phonon confinement effect. The results for the binding energy as well as polaronic correction are obtained as a function of the wire radius, impurity position and applied fields. Calculated results reveal that the values of the polaronic shifts of impurity binding energy can be quite different for cases with finite and infinite confining potentials.
Fabrication of Super Paramagnetic Nanoparticles by Sol-Gel Method for Water Purification
Authors: Shaker Sarah , Zafarian Shirzad , Chakra Shilpa , Rao K. Venkateswara , Badii Khashayar , Aftabtalab Adeleh , Sadabadi Hamed
Published: November 2013

Present work is focused on synthesis and characterization of super paramagnetic nanoparticles which showed a high adsorption capacity of dyes which are the first contaminant to be recognized in wastewater of different industries such as paper and textiles. One of these dyes is congo red which is an anionic diazo dye with two azo groups. Magnetite (Fe3O4) nanoparticles were prepared successfully by Sol–Gel method by using ferric nitrate (Fe (NO3)39H2O) and ethylene glycol (C2H6O2) as precursors which were annealed at different temperatures. The obtained nanoparticles were characterized by X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM), Vibrating Sample Magnetometer (VSM) and Zeta Potential. The phase structures, particle sizes and morphologies of Fe3O4nanoparticles were determined by XRD and TEM. VSM shows the magnetic properties of nanoparticles. The results indicate that the obtained nanoparticles are single phase and the particle size and coercivity value of Fe3O4nanoparticles increased with the increase in annealing temperatures. Zeta Potential determined the surface charge of nanoparticles and the results show that nanoparticles can adsorb congo red. The adsorption capacity was evaluated using both the Langmuir and Freundlich adsorption isotherm models.
Fabrication of Carbon Nanotube Granules as Pd Catalyst Supports for Hydrogenation of Carbon-Carbon Triple Bond
Authors: Poursharif Akram , Kazemzad Mahmood , Tabrizi Nooshin Salman
Published: November 2013

Hydrogenation is one of the most important transformation reactions widely used in a large variety of areas such as Chemical, pharmaceutical and agricultural industries. Granulated carbon supported palladium catalysts have been used here for hydrogenation of carbon-carbon triple bonds. Catalyst composites and granules were produced by using sodium alginate binder under the certain thermal treatment process. After that, metal salt precursors were deposited using impregnation method. The final catalysts obtained through reduction of metal oxides by hydrazine as reducing agent. After that, metal particles loaded catalysts were utilized to perform hydrogenation reaction. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) techniques applied for investigation of catalysts. Reaction products were evaluated by High Performance Liquid Chromatography (HPLC) technique. It has been concluded that MWCNT as support exhibits high conversion in the hydrogenation of 2-butyne-1, 4-diol as a typical triple bond carbon-carbon precursor.
Preparation of Nano Crystalline Titanium Dioxide by Microwave Hydrothermal Method
Authors: Moghimifar Vahid , Raisi Ahmadreza , Aroujalian Abdolreza , Bandpey Niloofar Bayani
Published: November 2013

Titanium dioxide (TiO2) nanoparticles due to their exclusive physical, chemical and electrical properties are widely used as a heterogeneous catalyst and catalytic support in the chemical reactions, a semiconductor for photocatalysis reactions and additives in the membrane processes. The TiO2 nanoparticles are also utilized in solar cells, gas sensors, pigments and etc. Efficiency of these nanoparticles in various applications is dramatically dependent on their size. Various techniques such as combustion flame synthesis and conventional hydrothermal methods have been used to prepare TiO2 nanoparticles, but few synthesis techniques can reproducibly produce particles below 10 nm. In this study, the TiO2 nanoparticles in rutile phase were synthesized by microwave assisted hydrothermal method by controlling the crystallization time and temperature. Titanium tetrachloride (TiCl4) was used as a titanium precursor. The synthesized nanoparticles were characterized by X-ray powder diffraction (XRD) and Scanning Electron Microscope (SEM) analysis. The XRD pattern showed that the rutile phase of the TiO2 nanoparticles was successfully synthesized by the proposed method with the average crystal size of 4nm. Finally, the prepared Titanium dioxide (TiO2) nanoparticles were as a hydrophobic additive in the polymeric ultrafiltration membranes in order to reduce the membrane fouling.
Protection of High-Tech Buildings Facades and Envelopes with One Sided Nano-Coatings
Authors: Nazari Marzieh , Mahdavinejad Mohammadjavad , Bemanian Mohammadreza
Published: November 2013

Pollution on building façades deteriorates buildings' image and causes structural problems as well as aesthetic issues. It is necessary to clean up pollutants from façades to prevent erosion of materials and further unpleasant consequences. Nowadays emergence of new skyscrapers increased and considerable amount of money wasted each year for façade cleaning processes. Thus it is necessary to find new methods to protect buildings facades by usage of recombinant nanomaterials and nanocoatings. Nanotechnology opens a new window in front of building industry and high technology in construction. Literature review of the paper shows that the most of pollutant origin is presence of moisture in air as well as building mortars. While current methods of cleaning pollutants accelerate erosion. The most important aim of this research is finding some waterproof coating that can protect building facades from variety of pollutants. In theoretical points of view here is dilemma about moisture conduction. Usage of waterproof coating may cause considerable damages to mortar of buildings' walls because the architectural elements in need of some occasions to be dried, especially masonry constructed buildings which have to be dried in a long period of time. Therefore the important issue is necessity existence of ventilation in order to moisture in mortar can be dried. Usages of waterproof coatings isolate the moisture in mortar behind coating layer and will result in decay. Our experimental studies show that Silane and Siloxane nanocoatings may help building facades resist against pollutants especially in high-tech architecture.
Effect of Equal Channel Angular Pressing on the Microstructure and Mechanical Properties of AISI Type 304 Austenitic Stainless Steel
Authors: Toofaninejad Mohsen , Ahmadabadi Mahmoud Nili
Published: November 2013

The present paper describes the effect of severe plastic deformation on the microstructure and mechanical properties of AISI type 304 stainless steel by equal channel angular pressing (ECAP) at room temperature. The strain-induced martensitic transformation occurred in the specimens, and martensite phase increased with increasing strain up to 42% for three passes of ECAP. X ray diffraction was used to identify the strain-induced martensite phase and its volume fraction. The martensite phase, mechanical twins and micro hardness have increased with increasing passes of ECAP. Microstructures of specimens show that with increasing strain, subgrains less than microns are susceptible to be created by fragmentation of twins.
Effect of Nitrogen Doping on the Phase Evolution of the TiO2 Nanoparticles
Authors: Derakhshani Mohammad , Abdizadeh Hossein , Golobostanfard Mohammad Reza
Published: November 2013

Recently photocatalytic materials have been used in variety of industrial applications. TiO2 is the only suitable photocatalytic material for industrial usage due to its benefits such as non-toxicity, stability, and low cost. TiO2 nanoparticles were successfully synthesized from titanium alkoxide precursor by sol-gel method. Effects of nitrogen doping on the microstructure and phase evolution of the TiO2 nanoparticles were investigated. The X-ray diffraction results of doped samples confirm the presence of anatase as the only crystalline phase. The addition of nitrogen in titania matrix leads to disappearance of rutile traces. The scanning electron microscopy show that TiO2 nanoparticle size decreases by increasing nitrogen doping. Furthermore, DSC-TG results reveal that the crystallization temperature of doped sample shifts to higher temperatures of about 100 °C.
Electrophoretic Deposition of Titania Thin Films: Influence of Deposition Time on Microstructural and Optical Properties of the Coatings
Authors: Ghannadi Saber , Abdizadeh Hossein , Golobostanfard Mohammad Reza
Published: November 2013

Titania thin films were prepared by electrophoretic deposition at various deposition times (1, 5 and 10 min) in constant applied potential (5 V). For this purpose, modified titania sol was prepared as a colloidal suspension. The influence of deposition time on the thickness and optical properties of titania films was investigated. Scanning electron microscope images illustrate compact and homogeneous titania films deposited on FTO substrates. The results show that the film thickness increases with increasing the deposition time. It could be inferred from UV-Vis spectroscopy that increasing the thickness of deposited film causes higher absorbance at UV region. Also, increasing the deposition time from 1 to 5 min leads to increase in optical band gap of the deposited films.