Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
33
9
2020
09
01
Determination of Riboflavin by Nanocomposite Modified Carbon Paste Electrode in Biological Fluids Using Fast Fourier Transform Square Wave Voltammetry
1696
1702
EN
M.
Asgharian Marzabad
0000-0002-3515-4611
CEITEC—Central European Institute of Technology and Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, Czechia
asgharian.mahyaa@gmail.com
B.
Jafari
Center of Excellence in Electrochemistry, School of Chemistry, College of Science, University of Tehran, Tehran, Iran
b.jafari2588@gmail.com
P.
Norouzi
Center of Excellence in Electrochemistry, School of Chemistry, College of Science, University of Tehran, Tehran, Iran+Biosensor Research Center, Endocrinology & Metabolism Molecular-Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
norouzi@khayam.ut.ac.ir
10.5829/ije.2020.33.09c.01
Herein, fast Fourier transformation square-wave voltammetry (FFT-SWV) as a novel electrochemical determination technique was used to investigate the electrochemical behavior and determination of Riboflavin at the surface of a nanocomposite modified carbon paste electrode. The carbon paste electrode was modified by nanocomposite containing Samarium oxide (Sm<sub>2</sub>O<sub>3</sub>)/reduced graphene oxide (RGO) (2:1) to improve detection sensitivity of Riboflavin under optimal experimental conditions. Furthermore, the signal-to-noise ratio was significantly increased by application of discrete fast Fourier transformation analysis, background subtraction and two-dimensional integration of the electrode response over the selected potential range and the time window. Obtained cyclic voltammograms demonstrated a diffusion-controlled reversible electron transfer reaction for Riboflavin in phosphate buffer solution (pH=7.2). The peak potential values were pH-dependent, involving the same numbers of protons and electrons. To obtain the maximum sensitivity, some effective parameters such as scan rate (10 mV/s), accumulation time (0.2 s) and potential (+400 mV), frequency (1420 Hz) and amplitude (20 mV) were optimized. As a result, determination of Riboflavin using FFT-SWV showed a linear range of response from 10 to 400 nM (R<sup>2</sup>=0.9993), with limit of detection of 0.86 nM. An acceptable recovery percent was also obtained for Riboflavin in human plasma samples as criteria of measurement applicability of the proposed modified electrode.
fast Fourier transforms square wave voltammetry,Riboflavin,Reduced graphene Oxide,Samarium Oxide
https://www.ije.ir/article_108476.html
https://www.ije.ir/article_108476_043589a3456c9f6555eb0ace4cdd069a.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
33
9
2020
09
01
Experiments on Coupled Technique for Adjacent Similar Buildings
1703
1709
EN
U.
Ramakrishna
0000-0001-9308-8483
Department of Civil Engineering, BITS Pilani Hyderabad Campus, Hyderabad, Telangana, India
p20170409@hyderabad.bits-pilani.ac.in
S. C.
Mohan
Department of Civil Engineering, BITS Pilani Hyderabad Campus, Hyderabad, Telangana, India
mohansc@hyderabad.bits-pilani.ac.in
10.5829/ije.2020.33.09c.02
Increasing the population, urbanization has led to the rapid construction of buildings. Due to space constraints and an increase in land cost, these buildings are built too close to each other and can cause damage under dynamic actions such as earthquakes. A new technique, known as Structural coupling, has been developed recently, has found very effective in dissipating the dispersive vibrations. In this technique, two adjacent dissimilar buildings are connected through a coupling device, such that it can reduce the dynamic response of the structure. The application of the structural coupling technique becomes challenging for similar buildings due to their in-phase behavior under dynamic loads. In the current research, the seismic performance of similar buildings with the coupling technique is experimentally tested on a shake table. A three storey model has been simulated using a unidirectional shake table with the scaled ground motion. Similar building construction uncertainties are accounted for in the study with slight variations in their dynamic properties. The connection devices used are bracings and passive viscoelastic dampers. The results obtained confirm the effectiveness of structural coupling technique with various configurations of dampers for similar buildings over seismic protection individual buildings.
Similar Building,structural coupling,Bracing,Viscoelastic Damper,shake table
https://www.ije.ir/article_113060.html
https://www.ije.ir/article_113060_f8bc1fcb6036dd732036df3938fcfb3d.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
33
9
2020
09
01
Experimental Investigation of Porosity, Installation Angle, Thickness and Second Layer of Permeable Obstacles on Density Current
1710
1720
EN
A.
Jahangir
0000-0002-4338-2219
Department of Water science and Engineering, Ferdowsi University of Mashhad, Mashhad, Iran
ar.jahangir@mail.um.ac.ir
K.
Esmaili
0000-0001-5354-0949
Department of Water science and Engineering, Ferdowsi University of Mashhad, Mashhad, Iran
esmaili@um.ac.ir
M. F.
Maghrebi
0000-0002-0082-0020
Department of Civil Engineering, Ferdowsi University of Mashhad, Mashhad, Iran
maghrebi@um.ac.ir
10.5829/ije.2020.33.09c.03
This study explored the effect of porosity and installation angle, thickness (dimension) and second layer of permeable obstacles on density current control and trapping in the laboratory. For this purpose, an insoluble suspended polymer and two types of groove and cavity obstacles made from plexiglass sheets were selected. The experiments were conducted with two different concentrations, five different porosities, four different angles, four different thicknesses and two obstacle layers. The results showed that the optimum porosities for cavity and groove obstacles were 22 and 19%, respectively. In all experiments, the cavity trapping rates of 0.13% and 0.14% at 10% and 20% concentrations were higher than those of groove trapping. In addition, by increasing the angle, the rate of trapping decreased and its value was observed in the groove with the correlation coefficients of 0.995 and 0.981 compared to the cavity. The major effect of obstacles was found to be the flow deceleration where the average velocity in the cavity was obtained 3.62% higher than that in the groove. For the increased thickness with 10% porosity and groove type, the passage of materials from the obstacle further increased. By creating the second layer of obstacle, the passage of materials from the obstacle in the both groove and cavity increased, and the optimal distance of the second obstacle was 2.25 m from the first one.
Density current,Obstacle porosity,Obstacle installation angle,Obstacle thickness,Second layer of obstacle,Permeable obstacle
https://www.ije.ir/article_113059.html
https://www.ije.ir/article_113059_d4e2f55f03601776ac8990eb81774d57.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
33
9
2020
09
01
An Investigation of the Seismic Interaction of Surface Foundations and Underground Cavities Using Finite Element Method
1721
1730
EN
E.
Shoja
Department of Civil Engineering, Zanjan Branch, Islamic Azad University, Zanjan, Iran
H.
Alielahi
Department of Civil Engineering, Zanjan Branch, Islamic Azad University, Zanjan, Iran
h.alielahi@iauz.ac.ir
10.5829/ije.2020.33.09c.04
In this study, the seismic interaction of surface foundations and underground cavities was investigated. For this purpose, a parametric study of geometric dimensions of the foundation and cavity, their location, and the effect of the interaction between surface foundations and underground cavities was evaluated. The variable parameters include the ratio of the overburden height to the foundation width (H/B = 0.5, 1 and 2), the location ratio of the cavity to the foundation width (X/B=0, 2 and 8) and the ratio of the cavity diameter to the foundation width (d/B=0.5, 1 and 2), respectively. The accuracy of the finite element method was evaluated using a laboratory study and it was found that the used method provides an accurate prediction of tunnel behavior.The results indicated that by increasing the overburden height, the stress on the tunnel surfaces was increased for all values of X/B (the horizontal tunnel distance to the foundation width). Therfore, in the case where the tunnel is located exactly along the center at the bottom of the foundation (X/B=0, d/B=2), the maximum stress generated is approximately 2.13 times greater than its corresponding value in the ratio of the depth to width of 0.5 (X/B=0, d/B=0.5). It can be concluded that the higher overburden height, the greater stresses caused by the dynamic loads of the earthquake on the tunnel wall.
Surface foundation,Underground cavities,Finite element method,Seismic interaction
https://www.ije.ir/article_108501.html
https://www.ije.ir/article_108501_d0c22908173d4aad7dd8b4b410932b58.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
33
9
2020
09
01
Intrusion of Geomesh in Gypseous Soil Under Single Footing
1731
1736
EN
W. A.
Zakaria
Engineering College, Civil Department, University of Diyala, Iraq
waadzakariya@yahoo.com
10.5829/ije.2020.33.09c.05
Methods to improve bearing capacity of footing resting of collapsing soil can, in fact, take two approaches, improving soil strength properties and intrusion of reinforcing sorces into soil. The footing is modeled by a square steel plate 0.1 by 0.1 m. The footing is loaded as to have a stress of 40 kPa and settlement is receded in dry and in soaking conditions. Two depths of the geo-mesh reinforcement are used, one B (B is width of footing) and 0.5B. For one B depth, three different square sizes of geo-mesh are used, 4B, 6B, and 8B. For the reinforcement depth of 0.5B the three sizes of the geo-mesh used are, 3.5B, 5.5B, and, 7.5B. Results reveal that the best improvement obtained is the case of square geo-mesh width of 7.5B and located at depth of B/2 under footing, with an improvement in terms of collapse settlement of 35%, and a settlement reduction in dry condition of 50%. The least improvement is the case of square geo-mesh with width of 4B and depth of one B, and it was really negligible, about 4% decrease in collapse settlement. Other cases varied between the two mentioned ratios. For findings of study, author recommends not to use geomesh size less than size of footing and not to place it in a depth more than half footing width. As such, in a whole, the effectiveness of geomesh in reducing the settlement of collapsing soil is obvious if used in proper way.
footing,Geo-grid reinforcement,Geo-mesh reinforcement,Laboratoryl,Soil Improvement
https://www.ije.ir/article_108503.html
https://www.ije.ir/article_108503_b2a7b27863fccf1d1c45e8280db62bfd.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
33
9
2020
09
01
Collapse Problem Treatment of Gypseous Soil by Nanomaterials
1737
1742
EN
A. L.
Hayal
Civil Engineering Department, University of Kufa, Kufa, Iraq
A. M. B.
Al-Gharrawi
Civil Engineering Department, University of Kufa, Kufa, Iraq
M. Y.
Fattah
https://orcid.org/00
Civil Engineering Department, University of Technology, Baghdad, Iraq
myf_1968@yahoo.com
10.5829/ije.2020.33.09c.06
Investigation of the effect of using nanomaterials for improving and Stabilizing the gypseous soil was carried out using laboratory works. The gypseous soils were collected from a site of intake in Bahar Al-Najaf and mixed with two types of nanomaterials (Nano-silica and, Nano-clay) where the nanomaterials were added in small amounts as a percent of the dry weight of the soil sample. Tests to determine the sieve analysis, specific gravity, and collapse potential were performed. The results of the experimental work showed significant modification in the geotechnical properties of the soil sample. The collapse potential decreases as soon as the used nanomaterials were increased until they reach a percentage after which the collapse potential will be increased. Thus, addition of nanomaterials, even at a low percentage, could improve the properties of gypseous soil. When adding the nano-silica to the soil, the collapse potential (CP) is decreased whenever the nano-silica increases until 1% of the added nanomaterials and then further stabilizer increases the (CP), the percent of decrease in CP is about 91% where the effect of the additive (nano-silica) changes the classification of severity of collapse from “moderate trouble” case to “no problem” case.
Collapse Soil,Gypseous soil,nano materials,Soil Improvement
https://www.ije.ir/article_108504.html
https://www.ije.ir/article_108504_fe65084856e6de7f847bf405eb48fd61.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
33
9
2020
09
01
Plant Classification in Images of Natural Scenes Using Segmentations Fusion
1743
1750
EN
N.
Nikbakhsh
Department of Electrical & Computer Engineering, Babol Noshirvani University of Technology, Babol, Iran
nanikbakhsh@yahoo.com
Y.
Baleghi Damavandi
0000-0002-2882-4613
Department of Electrical & Computer Engineering, Babol Noshirvani University of Technology, Babol, Iran
y.baleghi@nit.ac.ir
H.
Agahi
Department of Mathematics, Faculty of Basic Science, Babol Noshirvani University of Technology, Babol, Iran
h_agahi@nit.ac.ir
10.5829/ije.2020.33.09c.07
This paper presents a novel approach to automatic classifying and identifying of tree leaves using image segmentation fusion. With the development of mobile devices and remote access, automatic plant identification in images taken in natural scenes has received much attention. Image segmentation plays a key role in most plant identification methods, especially in complex background images. Where there are no presumptions about leaf and background, segmentation of leaves in images with complex background is very difficult. In addition, each image has special conditions, so parameters of the algorithm must be set for each image. In this paper, image segmentation fusion is used to overcome this problem. A fast method based on maximum mutual information is used to fuse the results of leaf segmentation algorithms with different parameters. Applying Tsallis entropy and <em>g</em>-calculus, generalized mutual information equations are derived and used to obtain the best consensus segmentation. To evaluate the proposed methods, a dataset with tree leaf images in natural scenes and complex backgrounds is used. These images were taken from Pl@ntLeaves dataset and modified so that they do not have a presumption. The experimental results show the use of Tsallis entropy and <em>g</em>-calculus in image segmentation fusion, improves plant species identification.
g-calculus,Image Segmentation Fusion,Mutual Information,Plant Classification,Tsallis Entropy
https://www.ije.ir/article_113062.html
https://www.ije.ir/article_113062_732d8b99ff8e5c38a2cd97c426a68364.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
33
9
2020
09
01
Quay Cranes and Yard Trucks Scheduling Problem at Container Terminals
1751
1758
EN
S.
Behjat
Industrial & Systems Engineering Faculty, Tarbiat Modares University, Tehran, Iran
saeed.behjat@yahoo.com
N.
Nahavandi
0000-0002-1445-6557
Industrial & Systems Engineering Faculty, Tarbiat Modares University, Tehran, Iran
n_nahavandi@modares.ac.ir
10.5829/ije.2020.33.09c.08
A bi-objective mathematical model is developed to simultaneously consider the quay crane and yard truck scheduling problems at container terminals. Main real-world assumptions, such as quay cranes with non-crossing constraints, quay cranes’ safety margins and precedence constraints are considered in this model. This integrated approach leads to better efficiency and productivity at container terminals. Based on numerical experiments, the proposed mathematical model is effective for solving small-sized instances. Two versions of the simulated annealing algorithm are developed to heuristically solve the large-sized instances. Considering the allocation of trucks as a grouping problem, a grouping version of the simulated annealing algorithm is proposed. Effectiveness of the presented algorithms is compared to the optimal results of the mathematical model on small-sized problems. Moreover, the performances of the proposed algorithms on large-sized instances are compared with each other and the numerical results revealed that the grouping version of simulated annealing algorithm outperformed simulated annealing algorithm. Based on numerical investigations, there is a trade-off between the tasks’ completion time and the cost of utilizing more trucks. Moreover increasing the number of YTs leads to better outcomes than increasing the number of QCs. Besides two-cycle strategy and using dynamic assignment of yard truck to quay cranes leads to faster loading and unloading procedure.
quay crane scheduling,yard truck scheduling,non-crossing,Simulated Annealing Algorithm,Grouping,safety margin,Container Terminals
https://www.ije.ir/article_108466.html
https://www.ije.ir/article_108466_1ac098f5773196422a380ce6aeabc4a2.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
33
9
2020
09
01
Investigation on Mechanical and Electrical Properties of Cu-Ti Nanocomposite Produced by Mechanical Alloying
1759
1765
EN
R. M.
Babaheydari
Department of Material Science and Engineering, Shahid Bahonar University of Kerman, Iran
mirahamdireza@yahoo.com
S. O.
Mirabootalebi
0000-0001-5793-6238
Department of Material Science and Engineering, Shahid Bahonar University of Kerman, Iran
oweiys@gmail.com
G. H.
Akbari
Department of Material Science and Engineering, Shahid Bahonar University of Kerman, Iran
ghh.akbari@gmail.com
10.5829/ije.2020.33.09c.09
In this paper, Cu-Ti nanocomposite synthesized via ball milling of copper-titanium powders in 1, 3, and 6 of weight percentage compounds. The vial speed was 350 rpm and ball to powder weight ratio kept at 15:1 under Argon atmosphere, and the time of milling was 90 h. Obtained powders were studied by scanning electron microscopy (SEM), X-ray diffraction (XRD), and dynamic light scattering (DLS). Crystallite size, lattice strain, and lattice constant were calculated by Rietveld refinement with Maud software. The results show a decrease in the crystallite size, and an increase in the internal strain and lattice parameter. Furthermore, the lattice parameter grew by increasing the percentage of titanium. Then, the powders compressed by the cold press and annealed at 650˚C, and finally, their micro-hardness and electrical resistance were measured. These analyses show that via increasing the proportion of titanium, Cu-6wt%Ti with 312 Vickers had the highest micro-hardness; due to the increasing the work hardening. Moreover, the results of the electrical resistance illustrate through increasing the amount of alloying material, the electrical resistance grew which the highest electrical conductivity was Cu-1wt%Ti with 0.36 Ω.
Copper-Titanium alloys,mechanical alloying,Electrical resistance,Mechanical properties
https://www.ije.ir/article_113058.html
https://www.ije.ir/article_113058_467dd5493805072d31b55a44251c4be7.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
33
9
2020
09
01
Effect of Mechanical Alloying and Sintering on Phase Transformation, Microstructural Evolution, Mechanical Properties and Density of Zr-Cr Alloy
1766
1772
EN
J.
Arasteh
0000-0002-3573-6558
Department of Materials Science and Engineering, Shahid Bahonar University of Kerman, Kerman, Iran
javadaraste68@gmail.com
10.5829/ije.2020.33.09c.10
The purpose of present research was production ofZr-based alloy as the nuclear fuel cladding by mechanical alloying (MA) and sintering process. Firstly, Zr and Cr powders were mechanically alloyed to produce the refractory and hard Zr-10 wt% Cr alloy, and then, the powder mixtures were consolidated by press and following sintering at temperature of 800˚C min. The phase evolution, microstructural changes, microhardness, and density of the Zr-10 wt% Cr alloy were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), microhardness measurement, and the Archimedes method. The results showed that the MA increased the solid solubility of the immiscible powders of Cr and Zr; therefore, the Cr atoms were completely dissolved in the Zr lattice after 24 h of the milling time and the nanostructured Zr(Cr) solid solution was obtained with the high microhardness value of about 491 Hv. Also, the results of the density measurement indicated that the resulted density was close to 98% of the theoretical density.
mechanical alloying,microhardness,NanoStructured,Sintering,Solubility
https://www.ije.ir/article_113064.html
https://www.ije.ir/article_113064_f76124cc5a811e97caa5e35a1381a6a5.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
33
9
2020
09
01
Experimental Study on Warm Incremental Tube Forming of AA6063 Aluminum Tubes
1773
1779
EN
F.
Rahmani
Department of Mechanical Engineering, Kar higher Education Institute, Qazvin, Iran
f.rahmani@kar.ac.ir
S. M. H.
Seyedkashi
0000-0002-1544-0733
Department of Mechanical Engineering, University of Birjand, Birjand, Iran
seyedkashi@birjand.ac.ir
S. J.
Hashemi
0000-0002-6605-4920
Department of Mechanical Engineering, Faculty of Enghelab-e Eslami, Tehran Branch, Technical and Vocational University (TVU), Tehran, Iran
s_j_hashemi@tvu.ac.ir
10.5829/ije.2020.33.09c.11
Effect of temperature on formability of AA6063 aluminum tubes in incremental forming process was investigated. Experiments are performed on AA6063 aluminum tubes. A spirally moving tool incrementally expands the tube wall. The tube is clamped from both ends while the deformation zone is not in contact with the die. A circumferential heating system is used to heat the tube due to the low formability of aluminum alloys at ambient temperature. The effects of process parameters including temperature, radial feed, axial feed and tool linear velocity are investigated in order to obtain the highest formability and surface quality. The results show that with a temperature rise from 100°C to 300°C, the expansion ratio increases from 28% to 34%. Axial feeding and temperature are the most effective parameters on the surface roughness and bulge diameter, respectively.
Warm incremental tube forming,Expansion Ratio,Surface roughness,Temperature
https://www.ije.ir/article_108470.html
https://www.ije.ir/article_108470_6e5cb424bd60f35b9d5c12f0401b8a1e.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
33
9
2020
09
01
Effects of Drying Temperature and Aggregate Shape on the Concrete Compressive Strength: Experiments and Data Mining Techniques
1780
1791
EN
K.
Reza Kashyzadeh
0000-0003-0552-9950
Department of Mechanical and Instrumental Engineering, Academy of Engineering, Peoples’ Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya Street, Moscow, Russian Federation
kazem.kashyzadeh@gmail.com
S.
Ghorbani
0000-0003-0251-3144
Department of Mechanical and Instrumental Engineering, Academy of Engineering, Peoples’ Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya Street, Moscow, Russian Federation
gorbani-s@rudn.ru
M.
Forouzanmehr
School of Science & Engineering, Division of Solid Mechanics, Sharif University of Technology, International Campus, Kish Island, Iran
foruozanmehr@gmail.com
10.5829/ije.2020.33.09c.12
The main purpose of this paper is to assess the impact of the geometry and size of the aggregate, as well as the drying temperature on the compressive strength of the ordinary concrete. To this end, two aggregates with sharp and round corners were prepared in three different aggregate sizes. After preparing concrete samples, the drying operations were carried out in the vicinity of room temperature, cold wind, and hot wind. Next, the linear relationship between the concrete strength and the studied parameters was estimated using Multiple Linear Regression (MLR) method. Finally, the Taguchi Sensitivity Analysis (TSA) and Decision Tree Analysis (DTA) were applied in order to determine the importance of the parameters on the compressive strength of concrete. As a result, it is obtained that the aggregate size has the greatest influence on the compressive strength of the ordinary concrete followed by drying temperature as stated by method TSA and DTA. In addition, the influence percentages reported for each parameter by Taguchi approach and decision tree method are matched. The prediction of the strength obtained by Taguchi method and second-order regression with the experimental data are in a good agreement. It was concluded that the impact of drying temperature on the concrete strength is several times greater than the effect of the aggregate geometry. Finally, the main conclusion of this research is related to the application of cold wind for drying operation, which leads to an increase of the compressive strength by 8.67% and 11.55% for ordinary concrete containing a constant aggregate size of 20 and aggregate geometries of round and sharp corners, respectively.
Concrete,Compressive strength,aggregates,Drying process,Temperature
https://www.ije.ir/article_108477.html
https://www.ije.ir/article_108477_be566c6e835450fa541974c0f40330d8.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
33
9
2020
09
01
Ballistic Testing and Simulation of Co-continuous Ceramic Composite for Body Armour
1792
1796
EN
A. S.
Prasanth
0000-0002-6026-8012
Department of Mechanical Engineering, PSG College of Technology, Coimbatore, India
asp.mech@psgtech.ac.in
R.
Ramesh
0000-0001-8415-7942
Department of Mechanical Engineering, PSG Institute of Technology and Applied Research, Coimbatore, India
ramesh@psgitech.ac.in
T. S.
Kavinesh Sankaar
Department of Mechanical Engineering, PSG College of Technology, Coimbatore, India
tskavinesh2@gmail.com
10.5829/ije.2020.33.09c.13
Co-Continuous Ceramic Composites, referred to as C4, have bi-continuous, interconnected and interpenetrating phases of a metal and ceramic. This bestows such composites with a higher strength to weight ratio compared with traditional composites. In this research work, a C4 composite of AA5083/SiC is fabricated for personal body armour, using gravity infiltration technique. A numerical simulation model of the C4 specimen is developed. This finite element model is utilized to simulate the DoP of a subsonic bullet into the C4 and is estimated as 1.47 mm. The C4 specimen is then, subjected to ballistic tests. A medium velocity projectile with a rated velocity of 326 m/s is used to impact the C4 specimen. The ballistic tests validate the numerical simulation with a DoP of 1.5 mm. Visual inspection reveals brittle cracks and interfacial debonding in the impacted C4. The results indicate that, such composites can potentially be utilized as low cost body armour.
Co-continuous Ceramic Composite,depth of penetration,Impact testing,numerical simulation
https://www.ije.ir/article_113061.html
https://www.ije.ir/article_113061_a447d60daad9c3a2424cca7ea3df160c.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
33
9
2020
09
01
Particle Swarm Optimization Based Parameter Identification Applied to a Target Tracker Robot with Flexible Joint
1797
1802
EN
M. H.
Sangdani
Department of Mechanical and Aerospace Engineering, Shiraz University of Technology, Shiraz, Iran
A. R.
Tavakolpour-Saleh
0000-0001-6981-1686
Department of Mechanical and Aerospace Engineering, Shiraz University of Technology, Shiraz, Iran
tavakolpour@sutech.ac.ir
10.5829/ije.2020.33.09c.14
This paper focuses on parameter identification of a target tracker robot possessing flexible joints using particle swarm optimization (PSO) algorithm. Since, belt and pulley mechanisms are known as flexible joints in robotic systems, their elastic behavior affecting a tracker robot is investigated in this work. First, dynamic equations governing the robot behavior are extracted taking into account the effects of considered flexible joints. Thus, a flexible joint is modeled by a non-linear spring and damper system connecting the motor to the link. It is found that the governing dynamic equations include some unknown parameters, which must be identified in order to design the robot system. Consequently, a PSO-based identification scheme is proposed to achieve the unknown variables based on the experimental data of the open-loop system. Lastly, for validating the proposed identification scheme, the obtained results are compared to the experimental measurements as well as the results of another similar work in which the robot is modeled with rigid joints. The consequences reveal that the mathematical model of the robot with flexible joint can describe the elastic behavior of the tracker robot. Thus, a better agreement between the simulation and experimental data are found in comparison with outcomes of the robot model with rigid joints.
Flexible Joint,Parameter identification,Particle Swarm Algorithm,target tracker robot
https://www.ije.ir/article_108485.html
https://www.ije.ir/article_108485_5b597f30514fce95c627e196dbbc4918.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
33
9
2020
09
01
Modeling and Optimization of Mechanical Properties of PA6/NBR/Graphene Nanocomposite Using Central Composite Design
1803
1810
EN
M. R.
Nakhaei
Faculty of Mechanics and Energy, Shahid Beheshti University, Tehran, Iran
m_nakhaei@sbu.ac.ir
G.
Naderi
Iran Polymer and Petrochemical Institute, Tehran, Iran
10.5829/ije.2020.33.09c.15
Thermoplastic elastomer of PA6/NBR reinforced by various nanoparticles have wide application in many industries. The properties of these materials depend on PA6, NBR, and nanoparticle amount and characteristics. In this study, the simultaneous effect of NBR and graphene nanoparticle content on mechanical, thermal properties, and morphology of PA6/NBR/Graphene nanocomposites investigated by Central Composite Design (CCD). Thermal properties and morphology of PA6/NBR/Graphene nanocomposites were investigated by Differential Scanning Calorimetry (DSC), X-Ray Diffraction (XRD), and Scanning Electron Microscopy (SEM). The results indicate that a small percentage of error between predicted values of mechanical properties and experimental values was achieved. An increase in graphene content have a positive impact on the tensile strength but increasing the NBR phase has the opposite effect. A maximum tensile strength of 35.3 MPa for PA6/NBR/Graphene nanocomposites was obtained at the NBR and graphene content of 20 %wt and 1.5 %wt, respectively. The thermal behavior of the PA6/NBR blend improved with addition graphene. With the addition of 1.5 % graphene content to PA6/NBR blend, the crystallization temperature and melting temperature increased from 192.1 to 196.2 °C and 221.1 to 223.4 °C, respectively.
Central composite design,Mechanical properties,Nanocomposite,PA6/NBR/Graphene,thermal properties
https://www.ije.ir/article_108488.html
https://www.ije.ir/article_108488_e924dd4bfc05c0971d6c95de2b872df6.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
33
9
2020
09
01
Effect of Heat Input on Microstructural and Mechanical Properties of AISI 304 Welded Joint Via MIG Welding
1811
1816
EN
S. A.
Rizvi
0000-0002-3526-2428
University Polytechnic, Jamia Millia Islamia,New Delhi, India
saritbhu@gmail.com
10.5829/ije.2020.33.09c.16
In this experimental work, AISI 304 was welded via metal inert gas (MIG) welding process with Argon (Ar) as shielding gas. In the present study, AISI 304 was subjected to different heat input using a standard 308L electrode. Weld quality i.e. ultimate tensile strength, toughness, microhardness, and microstructure of AISI 304 were examined. Microstructures of welded joints were studied using scanning electron microscopy (SEM), linked to the SEM was used to determine the chemical composition of phases formed at the joint interface and from the result, it was revealed that at low heat input ultimate tensile strength is higher than those at medium and low heat input. From the result, it was also observed that grain coarsening extent in the HAZ increases with an increase in the heat input. It was also found that the fractures of toughness samples were brittle in nature which shows the low ductility and brittle fracture. Weld zone microstructure exhibited skeletal δ-ferrite in austenite matrix with various ferrite contents. Microhardness of weld bead was found to decrease with increases in the heat input. It was also observed that at medium heat input there was an improvement in tensile strength, elongation, and hardness due to finer grain structure and smaller inter-dendritic spacing.
AISI 304,fracture mode,heat input,microhardness,Microstructure,MIG Welding,SEM
https://www.ije.ir/article_113063.html
https://www.ije.ir/article_113063_d7c2c0a8d814f9bea81303d909dab6eb.pdf