International Journal of Materials


ISSN: 2313-0555
Volume 3, 2016

Notice: As of 2014 and for the forthcoming years, the publication frequency/periodicity of NAUN Journals is adapted to the 'continuously updated' model. What this means is that instead of being separated into issues, new papers will be added on a continuous basis, allowing a more regular flow and shorter publication times. The papers will appear in reverse order, therefore the most recent one will be on top.

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Volume 3, 2016


Title of the Paper: Investigation of Micro-flexographic Printing Method in Fine Solid Lines Printing Structure by Graphene Ink

 

Authors: S. Hassan, M. S. Yusof, M. I. Maksud, M. N. Nodin

Pages: 98-103

Abstract: Micro-flexographic is a new printing method which is combination of flexography printing and micro-contact printing technique. Flexography printing is one of the high speeds production in roll to roll printing technique which commonly use in graphic printing industry. Micro-contact printing method usually use for micro to nano scale image especially in fine solid lines image structure. Ink is also one of the important parameter in micro to nano scale image printing. Graphene is a low cost material that suitable to use as a printing ink. Graphene ink has a capability in producing or printing image and electronic device in micro to nano scale structure. This research elaborates the use of graphene as a printing ink in combination of flexography and micro-contact printing method which known as micro-flexographic printing for micro to nano scale fine solid lines image. Here, it is proposed that extending micro-flexographic printing technique into the multiple micro to nano scale printing fine solid lines image onto biaxially oriented polypropylene (BOPP) substrate. This paper will investigate the capability of Micro-flexographic printing method in producing micro to nano fine solid lines image by using graphene ink for future printing development and application of printing electronic, graphic and bio-medical purpose.


Title of the Paper: Mathematical Modeling of Crown Fire Initiation in Three-Dimensional Setting

 

Authors: Valeriy Perminov, Alexander Goudov

Pages: 93-97

Abstract: Setting up and numerical solution of crown forest fire initiation and spread are presented with the use of a general mathematical model of forest fire. In this paper the theoretical investigations of the problems of forest fire initiation was carried out. Mathematical model of forest fire was based on an analysis of experimental data and using concept and methods from reactive media mechanics. The research was based on numerical solution of three dimensional Reynolds equations. The boundary-value problem is solved numerically using the method of splitting according to physical processes.


Title of the Paper: Direct Synthesis of Dimethyl Ether from Carbon Dioxide and from Mixture of Carbon Dioxide and Carbon Monoxide over Copper Alumina Catalysts Prepared by Using the Sol-Gel Method

 

Authors: Kaoru Takeishi, Yutaro Wagatsuma

Pages: 88-92

Abstract: Cu-Zn/Al2O3 catalyst and Cu-Ga/Al2O3 catalyst were prepared by using consecutive sol-gel method. These catalysts were used for direct synthesis of dimethyl ether (DME) from carbon dioxide, and from mixture of carbon dioxide and carbon monoxide. For comparison, a mixed catalyst of methanol synthesis catalyst and methanol dehydration catalyst was prepared according to a patent. The catalysts prepared by the sol-gel method are more effective for DME and methanol synthesis from CO2. Cu-Ga/Al2O3 catalyst is more effective for higher DME selectivity than Cu-Zn/Al2O3 catalyst. These significant catalysts were also tested for direct DME synthesis from mixture of CO2 and CO. The Cu-Zn/Al2O3 catalyst is more effective than the Cu-Ga/Al2O3 catalyst in this case.


Title of the Paper: Mathematical Modeling for Heat-Shrinkable Polymeric Article Production

 

Authors: Hossein Hosseini, Boris V. Berdyshev, Igor V. Iskopintsev

Pages: 83-87

Abstract: This paper presents a rheological model for producing hollow heat-shrinkable polymeric articles from thermoplastic materials. Heat-shrinking occurs as a result of internal rearrangement of the structural elements of a polymer. Practical tests for a one-step production technology of heat shrinkable products from conventional non-modified thermoplastic polymeric materials were successful. A non-linear viscoelastic model was developed that allows qualitative and quantitative prediction of the stress-strain behavior of heat-shrinkable polymers during heating and stretching. This research was done to develop a technique to determine the maximum possible change in size of heat-shrinkable products during heating. The rheological model used in this work was particularly suitable for defining process parameters and constructive parameters of the processing equipment and it provided a one-step production process for heat shrinkable thermoplastic articles.


Title of the Paper: Kinetic Modeling of Hydrocracking Process

 

Authors: Mohammad Mosaddegh, Hossein Hosseini

Pages: 79-82

Abstract: An investigation for achieving the kinetic of hydrocracking process with HC-201 catalyst, that is used in isomax unit of Tehran refinery, was carried out in a tubular reactor at temperatures of 380 and 420°C, pressures of 115 and 150 bar and space velocity of 1.5 hr-1 . In order to design and optimize hydrocracking process, a model is needed to express the effect of key features on the overall reaction rate. In this paper, based on the experimental results, a suitable kinetic model for the catalytic hydrocracking process was achieved in operating condition. There is a good agreement between theoretical results and experimental data.


Title of the Paper: Experimental Characterization of Strength and Elastic Compressive Properties for Unidirectional Carbon-Fiber Reinforced Composite

 

Authors: Sergey N. Shevtsov, Jiing-Kae Wu, Olga D. Alekseeva

Pages: 74-78

Abstract: The most comprehensive endurance characterization of high-strength polymeric composites subject to the external environmental action (humidity, cyclic temperature changes, and ultra violet radiation) can be obtained at the compressive testing of the material’s samples. Reinforcing fibers that are directed at acute angles to the part (or specimen) axis carry most of the load at tension,


Title of the Paper: Simplified Modeling of Cement Kiln Precalciner

 

Authors: Dimitris C. Tsamatsoulis

Pages: 69-73

Abstract: This study aims in developing of a simplified dynamic model of cement kiln precalciner between the feed rate of the primary fuel and the temperature at precalciner exit. The model includes perfect mixers connected in series. The optimum number of tanks and the dynamic parameters has been computed using production data. A successful attempt has been also performed to model the errors between the actual process values and the calculated ones by the dynamic model by autoregressive equations. The distributions of gain and time constant were also determined, providing information about the model uncertainty. The described simplified model could be used for parameterization of a PID controller for regulating the process. Due to its simplicity, the tuning results could be used at least as initial values of the controller.


Title of the Paper: The Effect of Friction Coefficient on Punch Load and Thickness Reduction in Deep Drawing Process

 

Authors: Sadık Olguner, A. Tolga Bozdana

Pages: 64-68

Abstract: This paper presents a numerical study for the determination of the effect of friction coefficient on punch load and thickness reduction in cylindrical cup deep drawing process. The effects of friction have been investigated by Finite Element Method (FEM). Finite element simulations have been carried out with material model of AISI 1006 cold rolled steel for deep drawing by using DEFORM-3D software. It was seen that the required punch load increases significantly with the increase of coefficient of friction between forming tools and sheet blank. Additionally, in order to see how limiting drawing ratio (LDR) is influenced by the friction, thickness reduction of sheet blank at flange and wall regions of drawn cup is evaluated for a specified drawing ratio under the influence of different friction conditions. Reduction of thickness was found to be more pronounced under a higher friction effect.


Title of the Paper: Modern Processing Technologies of All-Ceramic Dental Crowns with Various Zirconia Frameworks

 

Authors: Sorin Porojan, Liliana Porojan, Cristina Savencu

Pages: 60-63

Abstract: CAD/CAM (computer aided design/computer aided manufacturing) processing or zirconia frameworks and overpressing of the veneer are modern methods available to achieve all-ceramic bilayered crowns. Besides materials strength, other factors affect restorations’ clinical longevity, such as prosthesis design and technological steps. The aim of the study is to display alternative modern technologies for the fabrication of all-ceramic molar crowns with various zirconia frameworks. The individual processing procedures could cause structural flaws. The structural flaws may be located in the framework, at the veneer–core interface, at the surface, in the bulk of the veneering material, and lead to stress concentration as well as act as fracture initiation sites. An innovative modality for the improvement of all-ceramic restorations in the posterior areas might be the possibility to use glass ceramics as veneering material for zirconia cores and to adjust framework designs. Individual processing procedures are responsible for structural flaws.


Title of the Paper: The Rate of Chromium Leaching from Slag-Based Cement Composites in Different Leachants

 

Authors: J. Oravec, A. Estokova, S. Demcak

Pages: 56-59

Abstract: In this experiment, the reference concrete samples containing Portland cement as binder, and the concrete samples with the addition of ground blast furnace slag (65% and 95%, respectively as replacement of Portland cement) were analysed regarding the leachability of chromium. The prepared concrete samples were subjected to long-term leaching test for 500 days in three different leachants (distilled water, rainwater and Britton-Robinson solution). Subsequently, the concentration of chromium in the various leachates was measured by AAS method. The leaching parameters as values of the pH and the conductivity were also studied. Measured values of dissolved hexavalent chromium clearly indicate that the higher amount of slag was incorporated into the concrete samples the more of chromium was leached-out. Distilled water was found as the most aggressive leachant for chromium when compared to the other leachants used. This experiment clearly shows the need for the regulation and control of the waste addition to the construction materials and the need for long-term study in relation to the leaching of heavy metals into the environment.


Title of the Paper: Simulation of Nanocomposite Coating Created by Electrocodeposition Method

 

Authors: A. Vakhrushev, E. Molchanov

Pages: 44-55

Abstract: This paper reviews the recent experimental results from literature on electrocodeposition of nanoparticles in a metallic matrix. The mathematical model for hydrodynamic simulation of electrocodeposition of copper and alumina composite coating on rotating cylinder electrode is presented. The model can describe the hydrodynamics, particles size, current density and concentration of particles. It is found that the unsteady diffusion layer is formed close to the rotating electrode surface and the electro kinetics forces are the driving forces of the process. The good correlations with experimental data are received.


Title of the Paper: Investigation of CO2 Laser Drilled Micro Holes for Heat Affected Zone and Structural Integrity in CFRP Composites

 

Authors: Anarghya M., Nitish S. R., Yatheesha R. B., Gurumurthy B. M., Ranjith B. S.

Pages: 33-43

Abstract: This paper analyses the CFRP composites upon which laser drilling is performed using Marbach Compact CO2 laser cutting system (2115 DC-020), and their analysis is done through scanning electron microscope (SEM) JOEL JSM-6490 LV. Considering the continuous wave laser instead of the pulsed laser and the selection of the optimum gas pressure of 4bar of the assist gas (Argon) in the laser in this study has resulted in the contribution of least heat affected zones. Optimum parameters of the CO2 laser drilling techniques such as the cutting speed, gas pressure, assist gas, laser type, laser beam power, and frequency are developed. The characteristics of the workpiece such as the material, diameter, and thickness is also considered, and an optimization process is performed to maintain the structural integrity of the composite by reducing the induction of HAZ in the composite, after performing the laser drilling. The SEM images for the various parameter values are developed. The optimization of these parameter values concludes the paper.


Title of the Paper: Temperatures and Heat Transfer beneath a Ground Floor Slab

 

Authors: Iveta Skotnicova, Lenka Lausova

Pages: 26-32

Abstract: This paper presents the results of one-year period in situ experiment designed to monitor the thermal performance of a real slab-on-ground floor. Experimental measurements of the subsoil temperatures were performed outside and under the foundation (at various depths and locations) of a timber frame passive house. The results of the experimental measurements of the subsoil temperatures under the foundation of the passive house showed higher temperatures than predicted in standard calculating procedures and moreover they are not included in the calculations at all. The results of the measurements of the heat flux over a slab-on-ground floor are presented only for a short period of time and will be the subject of further research. This paper also reports the results of the calculation procedures proposed by the standards for slab-on-ground heat transfer. In the following paragraphs, the analytical detailed calculation procedure of CSN EN ISO 13370:2009, the analytical simplified method of CSN EN 12831:2004 and the numerical simulation methods of CSN EN ISO 10211:2009 are described and compared. Different boundary conditions (external design temperatures and external measured temperatures) were used. The ground temperatures were not included in the calculation procedures; only the thermal conductivity of the ground was respected. In particular, a two-dimensional finite element model, was used to simulate the heat transfer beneath a ground floor slab into the soil. The results showed that this model is more suitable tools to predict the thermal performance of the slab-on-ground floor than simplified analytical methods.


Title of the Paper: Role of Substrates in Self-Organized Coalescence of 3D Carbon Nanostructures

 

Authors: D. Fülep, I. Zsoldos, I. László

Pages: 20-25

Abstract: In the present work we study how the existence of graphite substrates effect growing process of nanotubes from graphene nanoribbons. For this purpose a HPC (High Performance Computing) –oriented simulation method were implemented in our research lab. The new modeling and computation method allows us to obtain conditions for the chosen problem of material science tighter and more precise than ever before.


Title of the Paper: The Parameters of the Thermal Panel Based on a Phase Change Materials

 

Authors: Martin Kolacek, Martin Zalesak

Pages: 7-12

Abstract: Article describes results of research of behavior and application of the thermal panels. These panels are based on the phase change materials under normal inner environment temperature in buildings. It was measured a several important parameters of thermal panel. Time constant, heat transfer coefficient and their changes in different surface treatment of the panels were measured. All process of measurement were done in heating mode with the thermal electric foil. The article describes the parameters of panel which were obtained by different methods measurement and calculation. The parameters were applied in simulation environment where was created a computer model. The simulation model was validated with the parameters that were measured on the real thermal panel. In the simulation environment were created a different application of these panels to determine an appropriate use


Title of the Paper: Material Construction of Replacement Brake Discs: A Regulation Compliance Study

 

Authors: Lamin F., Omar A., Osman M. R., Wong S. V.

Pages: 1-6

Abstract: Brake disc is a component of friction materials in a typical automotive braking system. Similar to other wear and tear automotive parts, which requires replacement, this definitely involves the after-market industry. Even though standard has been set, the actual compliance of the commercialised discs is still ambiguous. Products with a higher quality and performance are frequently referred to those with a higher price. However, the currently available studies provide no evidence of price effect on product quality. In this study, an experimental investigation was conducted to assess the commercial brake discs elemental composition compliance to the United Nation regulation of brake disc replacement, UN Regulation 90. As a case study, it focuses on replacement disc for a model of M1 vehicle category. By scrutinizing samples that were randomly selected from the after-market, elemental composition analysis were carried out through Energy Dispersive X-ray spectroscopy and assessment of variability of brake disc elemental composition were accordingly performed. The result reveal that there were significant deviation of the aftermarket replacement brake discs to the standard requirement. On top of that, no correlation observed between price and the standard compliance. The results presented here may facilitate improvements in the standard implementation, enforcement, market surveillance as well as after-market price controlling mechanism. Indeed, this is crucial in ensuring the current safety standard and subsequently enhancing it to an adequate and satisfactory level.