ORIGINAL_ARTICLE
Adsorption of Phenolic Compounds onto the Activated Carbon Synthesized from Pulp and Paper Mill Sludge: Equilibrium Isotherm, Kinetics, Thermodynamics and Mechanism Studies
A new activated carbon was produced from pulp and paper mill sludge as a low cost precursor via chemical activation by zinc chloride. The activated carbon was successfully used for the adsorption of phenol and two of its derivatives, i.e. 2-chlorophenol and 4-nitrophenol from aqueous solutions. The characterization of the prepared activated carbon demonstrated high textural properties for the synthesized activated carbon. The results revealed the superior adsorption performance of the prepared activated carbon in this study compared to the commercial one. The effect of main affecting parameters such as pH, contact time, concentration and temperature on adsorption of phenolic compounds was experimentally investigated in discontinuous system. The adsorption capacities followed the order of 4-nitrophenol > 2-chlorophenol >phenol which was attributed to the property of substituent groups in their chemical structure. Among isotherm models used to describe experimental equilibrium data, the best match was obtained by Sips isotherm which revealed the heterogeneous behavior of the adsorption sites on the adsorbent surface. Kinetic study demonstrated that the adsorption kinetics followed pseudo-second-order kinetic model. Based on thermodynamic analysis, the negative values obtained for free Gibbs energy, enthalpy and entropy indicated spontaneous, exothermic and randomness behavior of the adsorption process, respectively.
https://www.ije.ir/article_72387_da3cefbc31b5049672c4c9a478b40052.pdf
2014-10-01
1485
1494
Adsorption
precursor
Pulp and Paper Mill Sludge
Activated carbon
Phenolic Compounds
Ali Asghar
Ghoreyshi
aa_ghoreyshi@nit.ac.ir
1
Chemical Eng., Babol Nooshirvani University of Technology
AUTHOR
Mojtaba
Masomi
mojtabamasomi@yahoo.com
2
Chemical Engineering, Babol University of Technology
AUTHOR
ORIGINAL_ARTICLE
Synthesis and Characteristics of Mesoporous Sol-gels for Lipase Immobilization
Enzyme cost is the major problem for industrial scale application. Immobilization is a promising approach to moderate the enzyme cost factor and increase its stability and activity. In this study, sol-gel method was used to prepare the immobilization platform and entrapped lipase as one of the most used enzyme in dairy processing, cosmetics and pharmaceutical industries. Lipase from Candida rugosa was immobilized onto glycidoxypropyltrimethoxysilane(GPTMS) and tetramethoxysilane (TMOS) derived sol-gels and the characteristics and hyrdrolytic activity were investigated. Michaelis-Menten kinetic properties reveal that although free enzyme can catalyze the reaction faster, but it has lower affinity for substrate molecules compared to sol-gel immobilized lipase. Entrapped lipase retained 67 % of its initial activity after six reaction cycles. It showed 100% activity compared to free lipase powder at 40-45°C. In pH 9, as free enzyme lost 90 % of its initial activity, immobilized lipase lost only 29% of its activity. Immobilized enzyme was more stable toward different pHs (100% activity at pH 7.5 compared to free form). Morphological characteristics of the immobilized enzyme were investigated by SEM images and BET. The sample had specific surface area and mean pore diameter of 2.599 m2/g and 46.13 nm.
https://www.ije.ir/article_72388_34ee539b9629eb94f9c37814e9c41abb.pdf
2014-10-01
1495
1502
Enzymes
sol
gel process
Hydrolysis
Immobilization
Kinetics
Mesoporous
Mojdeh
Nickpour
mojdeh.nickpour@yahoo.com
1
Energy Department, Materials & Energy Research Center
AUTHOR
ORIGINAL_ARTICLE
Review Heat Exchanger: Research Development of Self-rotating Inserts in Heat Exchanger Tubes
Heat exchangers are widely used in power engineering and industrial applications, many techniques such as coiled tube, surface tension devices, rough surfaces, extended surfaces have been investigated to enhancethermal performance and to minimize the cost and size of the heat exchanger equipment. One of the most important techniques is tube insert. In general,tube inserts can be classified into two broad categories: stationary inserts and self-rotating inserts.Compared with stationary inserts, the self-rotating inserts can rotate in the tube by fluid and the comprehensive performance of self-rotating inserts is improved significantly.This paper mainly focuses on reviewing the large number of experimental and numerical works taken by researchers on self-rotating inserts such as twisted tapes,miniature hydraulic turbine,turbine-type swirl generatorsetc.toimprove the thermal efficiency of heat exchanger and serviceable to designers implementing passiveenhancement techniques in heat exchange. The authors found that self-rotating inserts can strengthen the heat transfer efficiency meanwhile achieve on-line automatic anti-scaling and descaling effect. When the fluid velocity is more than 0.2m/s, most of self-rotating inserts can be applied meanwhile the convective heat transfer correlations have been discussed. The heat transfer performance and frictional loss have been discussed to get the optimal configuration of self-rotating inserts. Determining how to find the optimal self-rotating insert is the main objective of this paper..
https://www.ije.ir/article_72389_0765d9b96a255fbadddc1a15dba95508.pdf
2014-10-01
1503
1510
Tube Inserts
self
Rotating
Heat transfer enhancement
anti
scaling and Descaling
Li
Wang
wang084071@163.com
1
School of Chemical and Energy Engineering, Zhengzhou University
AUTHOR
Ya-fei
Li
liyafeijayo@126.com
2
School of Chemical Engineering and Energy, Zhengzhou University
AUTHOR
Can-can
Zhang
zhangwu8887@126.com
3
School of Chemical and Energy Engineering, Zhengzhou University
AUTHOR
Ke
Xu
xukeup@163.com
4
School of Chemical and Energy Engineering, Zhengzhou University
AUTHOR
Jin-xing
Wu
kievenlee@163.com
5
School of Chemical and Energy Engineering, Zhengzhou University
AUTHOR
ORIGINAL_ARTICLE
Studying Performance of Dubinin-astakhov and Dubinin-raduchkevic Equations to Evaluate Nanopore Volume and Pore Size of MCM-41 Particles (TECHNICAL NOTE)
MCM-41 particles were synthesized using inorganic raw materials and Cetyltrimethylammonium bromide (CTAB). The textural properties and structure of MCM-41 particles were characterized by XRD, SEM, TEM and N2 adsorption-desorption methods. To study performance of Dubinin-Astakhov and Dubinin-Raduchkevic isotherm models in evaluating mesopore volume and pore size of MCM-41 samples, the mesopore volume and pore size of several MCM-41 samples were calculated by means of two mentioned isotherm models and by utilizing N2 adsorption isotherms and XRD data. The obtained results also compared with the mesopore volume and pore size calculated by other methods. The results showed that the calculated mesopore volume and pore size on the samples with the fraction of mesopore volume > 0.9 had not good consistency with XRD data and the results obtained by other methods. However, the calculated mesopore volume and pore size on the samples with the fraction of mesopore volume ≤ 0.9 were in good agreement with XRD data and other advanced simulation techniques.
https://www.ije.ir/article_72390_a64eebcc6e1a14d3598a9eef2201e092.pdf
2014-10-01
1511
1518
Nitrogen isotherm data
MCM
41
Dubinin
Astakhov and Dubinin
Raduchkevic equations
Nanopore (mesopore) volume
Pore Size
Mohammad Reza
Sarsabili
navid.saeedi13@gmail.com
1
School of Chemical, Gas and Petroleum Engineering, Semnan University
AUTHOR
Mehdi
Parvini
m.parvini@sun.semnan.ac.ir
2
Chemical, Gas and Petroleum Engineering, Semnan University
AUTHOR
Navid
Saeidi
navid_saeedi13@yahoo.com
3
School of Chemical, Gas and Petroleum Engineering, Semnan University
AUTHOR
ORIGINAL_ARTICLE
A Procedure for Preparation of Semi-activated Carbon Fiber without any Treatment under High Temperature
A procedure for preparation of semi-activated carbon fiber (SACF) without any treatment under high temperature was proposed. The first step of the procedure is coating of an inorganic fiber (E-glass fiber) by an adsorbent mixture including powder activated carbon, methyl cellulose and water. In this work a set of experiments was performed to attain appropriate adsorbent mixture for good quality of coating. The best composition was investigated based on the adsorption property and the mechanical property of the coated fibers. The results showed that an adsorbent mixture containing 3 wt% or 4 wt% of methyl cellulose, and 15-20 wt% of activated carbon represents good quality of coating. The adsorption property of the coated fibers was studied by determination of iodine number for the adsorbent mixture. In this work the weight percent of the coated adsorbent mixture on the fibers were also obtained and reported. The mechanical property was examined by flowing of air through a packing of the coated fibers. BET surface area of the samples also was examined and compared to other reported works. The results showed that the surfaces area of the samples were eighter equal to or higher than other disclosed works. The weight loss of the coated fibers packing was measured after 20, 40 and 60 min flowing of air through a packing of the SACFs. The weight loss in all cases was very low (up to 0.001 gr); thus good quality of coating can be inferred.
https://www.ije.ir/article_72391_760adeeb704f896b166d657eb163c59e.pdf
2014-10-01
1519
1526
Activated carbon fiber
Organic binder
Iodine number
Adsorption property
Mechanical Property
Mohammad Nader
Lotfollahi
mnlotfollahi@semnan.ac.ir
1
School of Chemical, Gas and Petroleum Engineering, Semnan University
AUTHOR
Navid
Saeidi
navid_saeedi13@yahoo.com
2
School of Chemical, Gas and Petroleum Engineering, Semnan University
AUTHOR
ORIGINAL_ARTICLE
Employing Internal Flexible Wall as Mass Absorber in Tanks Subjected to Harmonic Excitations
The possibility of employing internal wall as mass absorber in rectangular water storage tanks subjected to harmonic ground motion excitation is investigated in this paper. Internal walls are used in these tanks usually for service performance purposes, which could be used as mass absorber to control seismic demand on tank's exterior walls. Derivation of the response of the coupled system including rigid external walls, flexible internal wall and fluid field is in frequency domain. The responses of the tank are evaluated subjected to harmonic excitations. By tuning the dynamic behavior of the tank and the sloshing liquid by changing the mass and stiffness of internal flexible wall, it is shown that wave elevation and water pressure on external rigid walls can be significantly reduced.
https://www.ije.ir/article_72392_9f89dce09e3bae7634a58a214c5fa2c4.pdf
2014-10-01
1527
1536
Seismic Demand
Mass absorber
Fluid
structure interaction
water storage tanks
marziye
mousavi
mousavimarziye@yahoo.com
1
Civil Engieering, Islamic Azad University of Tabriz
AUTHOR
saeed
tariverdilo
s.tariverdilo@urmia.ac.ir
2
Civil Eng., Urmia Univ.
AUTHOR
jahan
mousavi
jahanmousavi@yahoo.com
3
Civil Engieering, Urmia University
AUTHOR
ORIGINAL_ARTICLE
Assessment of Goodness of Fit Methods in Determining the Best Regional Probability Distribution of Rainfall Data
One of the most important problems in time series analysis of stream flow and rainfall data in an area is selecting the best probability distribution. Since the rainfall stations are associated and correlated with each other, so statistical analysis of the station data seamlessly are very important. Therefore, the first step in data analysis, is selecting the prevailing probability distribution in the region. Probability Plot Correlation Coefficient (PPCC) method is one of the most simple, efficient, and pointed approaches in this field which is used for selecting the best probability distribution at each station. Among these, the method of L-Moments is also developed and has the capacity of regional analysis to choose the best probability distribution. In this study, we examine monthly and annual rainfall data for a period of 50 years with both PPCC and L-moments methods based on different evaluations, in the North West of Iran. Although, results from the two methods were almost identical, but because of the simplicity of calculations and the use of a curve to determine the best statistical distribution, the use of L-moments was recommended.
https://www.ije.ir/article_72393_008ef3489fd090e1065de769f7999117.pdf
2014-10-01
1537
1546
Probability Plot Correlation Coefficient
L
Moments
Goodness of fit
Majid
Montaseri
montaseri@hotmail.com
1
Water Engineering, Urmia University
AUTHOR
Babak
Amirataee
babak.amirataee@gmail.com
2
Water Engineering, Urmia University
AUTHOR
Hossein
Rezaei
hrezaei@hotmail.com
3
Water Engineering, Urmia University
AUTHOR
ORIGINAL_ARTICLE
Dynamic Response of Submerged Vertical Cylinder with Lumped Mass under Seismic Excitation
An analytical approach is presented to assess the response of offshore structures under seismic excitation. This paper evaluates the impacts of different fluid field models and the mass of equipment at the top of offshore structure which is simulated as lumped mass on the responses of offshore structures. To do this, two and three dimensional fluid field models are developed. In three dimensional models different approximation regarding the free surface boundary condition associated with high and low frequency excitations are adopted. Then the alternation of response of structure with changing in the value of lumped mass is calculated. Finally the impacts of different models on the value of maximum displacement for Kobe earthquake are evaluated. It is shown that different approximations regarding the fluid field could largely change the value of maximum displacement evaluated by the models.
https://www.ije.ir/article_72394_7764d0f7355b7eb7ea37d1564fc73d54.pdf
2014-10-01
1547
1556
vertical circular cylinder
Seismic Excitation
lumped mass
Added mass
Mahdieh
Shahmardani
mahdieh.shahmardani@polimi.it
1
Civil and Environmental Engineering, Urmia University
AUTHOR
Jamil
Mirzapour
mirzapour.jamil@gmail.com
2
Structural Engineering, Politecnico Di Milano
AUTHOR
saeed
tariverdilo
s.tariverdilo@urmia.ac.ir
3
Civil Eng., Urmia Univ.
AUTHOR
ORIGINAL_ARTICLE
A Fuzzy Rule-based Expert System for the Prognosis of the Risk of Development of the Breast Cancer
Soft Computing techniques play an important role for decision in applications with imprecise and uncertain knowledge. The application of soft computing disciplines is rapidly emerging for the diagnosis and prognosis in medical applications. Between various soft computing techniques, fuzzy expert system takes advantage of fuzzy set theory to provide computing with uncertain words. In a fuzzy expert system, knowledge is represented as a set of explicit linguistic rules.Diagnosis of breast cancer suffers from uncertainty and imprecision associated to imprecise input measures and incompleteness of knowledge of experts. However there are several technology-oriented studies reported for breast cancer diagnosis, few studies have been reported for the breast cancer prognosis. This research presents a fuzzy expert system for breast cancer prognosis to further support of the process of breast cancer diagnosis. This approach is capable enough to capture ambiguous and imprecise information prevalent in the characterization of the breast cancer. For this,the paper utilizes aMamdani fuzzy reasoning model, which has high interpretability for interacting with human expertsduringprognosis process and consequently early diagnosisof thediseased. The performance results on real patients' dataset reveal the accuracy of the system with an average 95% which shows the superiority of the system in the prognosis process compared to other related works.
https://www.ije.ir/article_72395_27a99168e5a218895abf36bdea53cac0.pdf
2014-10-01
1557
1564
fuzzy expert system
Soft Computing
breast cancer
Prognosis
Rahil
Hosseini
rahilhosseini@gmail.com
1
Computer Engineering, Shahr-e-Qods Branch, Islamic Azad University, Tehr
AUTHOR
Razieh
Khezri
universityhosseini@gmail.com
2
Computer Engineering, Shahr-e-Qods Branch, Islamic Azad University
AUTHOR
Mahdi
Mazinani
mahdi_mazinani@yahoo.com
3
Department of Electronic Engineering, IAU
AUTHOR
ORIGINAL_ARTICLE
Multi Attribute Analysis of a Novel Compact UWB Antenna with Via-fed Elements for Dual Band Notch Function (RESEARCH NOTE)
A compact microstrip-fed antenna with dual notched bands is proposed. First, a simple basic configuration is presented for Ultra Wide Band (UWB) applications and then the dual band notched structure is extended from the UWB one. The basic structure of the UWB antenna consists of a simple square radiating patch and a ground plane with a wide square slot on back of the substrate. A semi-circle shaped slot is cut from the ground plane to improve the antenna impedance matching. In the sequel, aimed at filtering Worldwide Interoperability for Microwave Access (WiMAX) and Wireless Local Area Network (WLAN), via-fed inverted T-shaped element and two rectangular stubs are embedded in the antenna structure. The presented antenna is printed on a 20 × 20 × 0.8 mm3 FR4 substrate and operates over the frequency range of 2.9-16 GHz with WiMAX WLAN notched. To compare the performance of the proposed UWB antenna with respect to some previous designes, a novel framework based on the Analytical Hierarchy Process (AHP) is proposed. Using AHP methodology, the important operational aspects of antennas are taken into account simultaneously, resulting in a comprehensive comparison. Expert Choice software is used to apply the AHP technique.
https://www.ije.ir/article_72396_f2c7ca6699d9d9dce0142fc1a41a25ad.pdf
2014-10-01
1565
1572
Analytical Hierarchy Process
Dual Band
Notch
Expert choice software
UWB antenna
VIA
fed elements
Maryam
Majidzadeh
maryam_majidzadeh37@yahoo.com
1
Electrical Engineering, Urmia branch, Islamic azad university
AUTHOR
Changiz
Ghobadi
ch.ghobadi@urmia.ac.ir
2
Electrical Engineering Department, Urmia branch, Islamic Azad University
AUTHOR
ORIGINAL_ARTICLE
Comparative Investigation of Half-mode SIW Cavity and Microstrip Hybrid Antenna Using Different Patch Shapes
A set of hybrid microstrip patch and semi-circular cavity antennas is introduced. The semi-circular cavity is implemented using Half-mode Substrate Integrated Waveguide (HMSIW) technique. Different shapes of patch include rectangular, semi-circular and equilateral triangular are excited using proximity effect by the circular SIW cavity at its TM010 mode of operation. The whole structures have been excited using an inset microstrip line that leads to facility of planar circuit integration. The inherent limited bandwidth of the conventional microstrip patch antenna and SIW cavity-backed slot antenna is improved about 6% to 9.5% depending on the type of the patch using the proposed structure. Additionally, the proposed hybrid antenna enhances the antenna gain by about 1.5 dB. Meanwhile, the proposed hybrid antennas are made on a single-layer substrate has a low fabrication cost using printed circuit board (PCB) process. Three hybrid antennas are numerically and experimentally investigated. A comparative study between the three different structures contains gain, bandwidth, cross polarization level (CPL) and Front to Back Ratio (FTBR) is presented.
https://www.ije.ir/article_72397_62beca7e686818fefa00cb904e02e41a.pdf
2014-10-01
1573
1580
Hybrid antenna
microstrip patch
SIW cavity
Hamide
Dashti
hamide.dashti@gmail.com
1
Electrical engineering, Ferdowsi univ. of Mashhad
AUTHOR
ORIGINAL_ARTICLE
Design and Implementation of Digital Demodulator for Frequency Modulated CW Radar (RESEARCH NOTE)
Radar Signal Processing has been an interesting area of research for realization of programmable digital signal processor using VLSI design techniques. Digital Signal Processing (DSP) algorithms have been an integral design methodology for implementation of high speed application specific real-time systems especially for high resolution radar. CORDIC algorithm, in recent times, is turned out to be a huge researched outcome for its easy realizability in on-chip design in the field of vector rotated DSP applications. In this paper we propose a pipelined CORDIC architecture for digital demodulation in high performance, low power frequency modulated CW Radar. A complex Digital Phase Locked Loop (DPLL) has been used for digital demodulation with pipelined CORDIC module as its core processing element. The FPGA implementation of CORDIC based design has been chosen because of its inherent high system throughput due to its pipelined architecture where latency is reduced in each of the pipelined stage. Substantial amount of resource utilization has been reduced in proposed design. For better loop performance of first order complex DPLL during demodulation, the convergence of the CORDIC architecture is also optimized. Multiplierless BOXCAR filter has been incorporated at the final stage of the design for better information recovery from narrow samples with little energy signal and easy realization. Hardware synthesized result using Cadence design tools are presented.
https://www.ije.ir/article_72398_da362c4658dc5c361a78506bb0efa0e3.pdf
2014-10-01
1581
1590
FMCW Radar
CORDIC
FPGA
DSP
DPLL
Loop performance
Rajesh
Mishra
rmishra@gmail.com
1
ICT, Gautam Buddha University
AUTHOR
Amritakar
Mandal
amritkar2k@gmail.com
2
Information Technology, Gautam Buddha University
AUTHOR
ORIGINAL_ARTICLE
Multi-objective Economic-statistical Design of Cumulative Count of Conforming Control Chart
Cumulative Count of Conforming (CCC) charts are utilized for monitoring the quality characteristics in high-quality processes. Executive cost of control charts is a motivation for researchers to design them with the lowest cost. Usually in most researches, only one objective named cost function is minimized subject to statistical constraints, which is not effective method for economic-statistical design of control charts. In this paper, a multi-objective model for the economic-statistical design of the CCC control chart is developed. Then, multi-objective evolutionary algorithm (NSGA-II) for obtaining the Pareto optimal solution of the model is proposed. A numerical example is applied to illustrate the effectiveness of the proposed model. This model leads to lower cost and smaller probability of Type I and Type II errors, compared with economic model. In addition, a sensitivity analysis is done to investigate the effect of input parameters on the best solutions of the proposed model.
https://www.ije.ir/article_72399_5914c2391226ab958dd32d0fd2788f71.pdf
2014-10-01
1591
1600
Statistical process control
Cumulative Count of Conforming Charts
high
Quality Processes
multi
Objective Economic
Statistical design
NSGA
II Algorithm
Anahita
Sherbaf Moghaddam
anahita.sherbafmoghaddam@gmail.com
1
Industrial Engineering, Shahed University
AUTHOR
ORIGINAL_ARTICLE
Designing a Meta-Heuristic Algorithm Based on a Simple Seeking Logic
Nowadays, in majority of academic contexts, it has been tried to consider the highest possible level of similarities to the real world. Hence, most of the problems have complicated structures. Traditional methods for solving almost all of the mathematical and optimization problems are inefficient. As a result, meta-heuristic algorithms have been employed increasingly during recent years. In this study, a new algorithm will be introduced for solving continuous mathematical problems. The basis of this algorithm is based on the group seeking logic. In this logic, the seeking region and the seekers located inside are divided into several sections and they will seek in that special area. In order to assess the performance of this algorithm, from the available samples in articles, the most visited algorithms have been employed. The gained results show the advantage of SEA in comparison to these algorithms. In the end, a mathematical problem has been designed, which is unlike the structure of meta-heuristic algorithms. All the prominent algorithms have been applied to solve this problem, and none of them was able to solve.
https://www.ije.ir/article_72400_33ac36d72957526e21907fdaaa1fea76.pdf
2014-10-01
1601
1610
evolutionary algorithms
meta
heuristic algorithms Global optimization
Seeker Evolutionary Algorithm (SEA)
Multiple global minima
Reza
Tavakkoli-Moghaddam
tavakoli@ut.ac.ir
1
Industrial Engineering, University of Tehran
AUTHOR
Nikbakhsh
Javadian
nijavadian@ustmb.ac.ir
2
Industrial Engineering, Mazandaran University of Science and Technology
AUTHOR
shahab
poursafary
matlabhome.ir@gmail.com
3
Industrial Engineering, Mazandaran University of Science and Technology
AUTHOR
ORIGINAL_ARTICLE
A Novel Hybrid Approach to Analyze Cost of Quality: Balanced Scorecard and Fuzzy Logic
In this paper, a new methodology in the area of cost of quality (COQ) is proposed to determine the optimal investment allocation to all costs. The goal is to minimize costs involved in achieving a required level of quality. The contribution of this paper is fourfold: (I) considering two types of weights for each part of COQ, in which the first type is determined by the cost volume and the second is obtained by applying a decision-making technique; (II) participating shareholders’ opinions through the balanced scorecard method; (III) presenting a mathematical programming model to maximize the investment effectiveness; and (IV) considering a continuous improvement cycle to tune the model parameters. In addition, we also develop a COQ technique in fuzzy environment to enhance the accuracy of traditional methods of employing linguistic variables. To demonstrate the applicability of the presented methodology, a numerical example is investigated.
https://www.ije.ir/article_72401_1f706fccc14533e0de69dd250abf7c95.pdf
2014-10-01
1611
1618
Cost of quality
Fuzzy logic
Balanced Scorecard
optimization
Continuous improvement
Fatemeh
Kangi
f.kangi@yahoo.com
1
Industrial & Mechanical Engineering, Islamic Azad University, Qazvin Branch
AUTHOR
Sadegh
Borji
s.borji@rocketmail.com
2
Industrial & Mechanical Engineering, Islamic Azad University, Qazvin Branch
AUTHOR
S.T.A.
Niaki
niaki@sharif.edu
3
Industrial Engineering, Sharif University of Technology
AUTHOR
Vahid
Hajipour
v.hajipour@qiau.ac.ir
4
Industrial & Mechanical Engineering, Islamic Azad University, Qazvin Branch
AUTHOR
ORIGINAL_ARTICLE
Comparison of Purity and Properties of Hydroxyl Carbonate Apatite Extracted from Natural Thigh Bone by Different Physio-chemical Methods
New approaches to extracting natural hydroxyl carbonate apatite from bio waste of bovine bones cortical femur have been developed. To extract pure and natural bio ceramics, three different treatments have been applied: 1-Calcination heat treatment at temperature of 700 , 2-alkaline hydrothermal at temperature of 275 and 3-Pressurized low polarity water at temperature of 250 . Raw bovine bone and obtained apatite have been characterized by Fourier-transform infrared spectroscopy, X-ray diffraction, differential thermal and thermal gravity analyzer and fluorescent microscopy and scanning electron microscopy. The results indicate that all the proposed processes have this ability to produce pure natural hydroxyl carbonate apatite from bio-waste bovine bones. In calcinations heat treatment process, mainly all the organic component such collagen was removed at temperature of 600 and a carbonate apatite was obtained. The presence of carbonate groups led to increasing the biocompatibility and will be preferable for orthopedic and medical usages. At The degree of crystallization of powders is increased by increasing of temperature from 250°C for pressurized low polarity water processing to 600°C for calcinations treatment. Growth behavior and adhesion of cultured umbilical cord mesenchymal stem cells on the surface of 2-D hydroxyapatite scaffolds derived by these three different methods have been investigated. The results show that the stem cells could survive and attach on surface of derived carbonated hydroxyapatite scaffolds and demonstrate no negative response.
https://www.ije.ir/article_72402_fb81e1e8a75cbb90eac664abdcf8ff88.pdf
2014-10-01
1619
1626
Hydroxyl Carbonate Apatite
Bovine bone
Calcinations
Alkaline and pressurized low polarity water hydrothermal
mahdi
kalantar
mkalantar@yazd.ac.ir
1
dep. of mining and metallurgy, Yazd University
AUTHOR
ORIGINAL_ARTICLE
Surface Activation of NiTi Alloy by Using Electrochemical Process for Biomimetic Deposition of Hydroxyapatite Coating (TECHNICAL NOTE)
Electrochemical depositions of calcium phosphate (Ca-P) film on NiTi alloy in concentrated simulated body flood (SBF×5) were carried out by cathodic polarization. The Ca-P layer was successfully deposited on Ni-Ti alloy substrate under 10mA/cm2 current density for 2 hours at room temperature. Then, in order to investigate the bioactivity of the pre-calcified samples, they were immersed in SBF for 1 and 3 days. The microstructure, composition and bioactivity of the coatings were evaluated by using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) techniques. Results showed that the activation of the surface of the NiTi alloy by electrochemical process can significantly enhance the biomimetic deposition during time. On the other hand, by increasing immersion time of pre-calcified samples in SBF from 1 to 3 days, the biomimetic coating uniformly covered the surface of the sample. The ratio of the Ca/P for the pre-calcified sample after immersion in SBF for 3 days was about 1.5 which is very close to the Ca/P ratio of stoichiometric hydroxyapatite.
https://www.ije.ir/article_72403_53d697b7f871cc76213513cf4c4b5410.pdf
2014-10-01
1627
1634
NiTi alloy
Electrodeposition
Bioactivity
Biomimetic coating
Hydroxyapatite
ehsan
Saebnoori
saebnoori@yahoo.com
1
Department of Materials Science and Engineering, Tarbiat Modares University
AUTHOR
Iman
vali
vali@yahoo.com
2
, semnan university
AUTHOR
ORIGINAL_ARTICLE
Prediction of Deformation of Circular Plates Subjected to Impulsive Loading Using GMDH-type Neural Network
In this paper, experimental responses of the clamped mild steel, copper, and aluminium circular plates are presented subjected to blast loading. The GMDH-type neural networks (Group Method of Data Handling) are then used for the modelling of the mid-point deflection thickness ratio of the circular plates using those experimental results. The aim of such modelling is to show how the mid-point deflection varies with the variations of the important parameters. Further, it is shown that the use of dimensionless input variables, rather than the actual physical parameters, in such GMDH-type network modelling leads to simpler polynomial expressions which can be used for modelling and prediction purposes. It is also demonstrated that Singular Value Decomposition (SVD) can be effectively used to find the vector of coefficients of quadratic sub-expressions embodied in such GMDH-type networks. Such application of SVD will highly improve the performance of GMDH-type networks to model of nonlinear dynamic behavior of circular plates.
https://www.ije.ir/article_72404_6a8f6043066a13ddb33fcc865d564120.pdf
2014-10-01
1635
1644
Neural Network
modelling
Circular plate
Impulsive load
deformation
S.
Minaeian
sminaeian@gmail.com
1
Industrial Engineering, Sharif University of Technology
AUTHOR