bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Alkaline Concentrations on the Tensile Properties of Napier Grass Fibre
Authors: Ridzuan Mohd Jamir Mohd , Abdul Majid M.S. , Afendi Mohd , Aqmariah Kanafiah S.N. , Nuriman M.B.M.
Published: August 2015

This paper presents an experimental investigation of the effects of alkaline treatment on the tensile properties of Napier grass fibres. The effect of different concentrations of NaOH aqueous solutions on the morphology and structure of the fibres were studied. The fibres were treated with 5%, 10%, and 15% of Sodium hydroxide (NaOH) concentration for 24 hours of soaking time. The single fibre tests were then performed in accordance with ASTM D3822-07 standard. The morphology of the fibres before and after alkali treatment was observed with a Metallurgical Microscope MT8100. The results show that the physical properties were varied after the treatments and 10% concentration of NaOH treatment yield the maximum tensile strength and elongation of the fibre at 172 MPa and 5.7% respectively. Morphology observation found that the fibre became thinner, and the surface roughness of the fibres increased with the increment of NaOH concentration.
Design and Fabrication of Hybrid Vehicle for Disabled Persons
Authors: Bhaskaran E.
Published: August 2015

Disabled Persons are one who has either legs or hands and it is duty of every individual to safeguard them. Government is helping through various schemes by supplying wheel chair etc. there is need for sophisticated vehicle for them to work in the factory by moving inside the factory premises, moving inside the house premises and office premises. The primary objective of this project is to develop a vehicle for Disabled Persons especially for people without legs. Hence extensive research was carried out to come out with this idea and its methodology by Voice of Customer and Quality Functional Deployment (QFD) analysis. Here handle bar is used with accelerator and brake incorporated. The Permanent Magnet Direct Circuit (PMDC) Motor is used in the brake drum driven by battery / solar current since this is a vehicle primarily designed for Disabled Persons, the vehicle is designed considering their disability in mind and much importance is given regarding the safety of the passenger after. Hence driver ergonomics plays a key role in the designing of vehicle for legless persons. Handle bar designed to suit both manual steering and electric steering. Chassis design and center of Gravity is calculated and the Brake is kept in the Handle Bar.
Minimising Material Handling Cost Using Relative Factors for Fixed Area Cell Layout Problem
Authors: Arulkumar P.V. , Saravanan M.
Published: August 2015

An importance of material handling is the movement of materials at the minimum cost and also an effective material handling system reduces the manufacturing cost. The objective of this paper is to reduce the material handling cost by placing the production equipments within the cell in the given fixed area layout. Few relative factors are considered while designing the layout. These factors help in improving the layout design. While designing the layout some higher cost assigned for some important moves. A benchmark problem has solved by using Artificial Bee Colony (ABC) and Particle Swarm Optimization (PSO) algorithms. The results are tabulated, compared, and analyzed. Based on that analysis the PSO algorithm performed well and given better placement of machines with minimum material handling cost.
Robotic Arm Design for Coconut-Tree Climbing Robot
Authors: Rajesh Kannan M. , Thejus P. , Allan P. , Trayesh V. , Gokul M.
Published: August 2015

Coconut is inseparable part of life of people of southern India particularly in the states of Kerala and Tamilnadu. Coconut as tender coconut water, coconut gratings, coconut milk, coconut oil etc. find its way in at least one food item cooked daily the people of this southern part of India. Due to extreme shortage in people to climb the coconut trees and pluck the coconuts, the cost of coconuts is increasing steeply. One solution to this problem is to have a robotic coconut tree climber with an arm to cut the coconuts. In this research work, we present the design, implementation and testing of robotic arms to be used in these robotic coconut tree climbers, to cut the coconuts. Different robotic arm designs are presented with proper analysis and results.
Evaluation of Adhesive T-Joint Using Finite Element Analysis
Authors: Izzawati B. , Afendi Mohd , Nurhashima S. , Nor A. , Abdullah Abdul Rahman , Daud Ruslizam
Published: August 2015

This study evaluates the effect of temperature upon adhesive properties and behavior of adhesively bonded T-joint. Finite element analyses established the effect of this parameter on the durability joint and stress distribution within the adhesive layer. A series of temperatures and stress analyses using finite element analysis (FEA) has been conducted in the T-joint configuration for this purpose. The parametric studies on the FE model revealed that stress distributions are sensitive to the changes in adhesive properties due to changes in temperature. In general, stresses were reduced with changes in the temperature which resulted in the ability of the adhesive layer to undergo plastic deformation.
Determining the Behaviour of Fatigue Strain Histories of Vehicle Coil Springs by Using Statistical Inferences
Authors: Mahmud Mashitah , Abdullah Shahrum , Ariffin Ahmad Kamal , Nopiah Z.M. , Yunoh M.F.M. , Mansor Nor Izan Izura
Published: August 2015

The evaluation of fatigue behavior of real components under service loading is important in reliability analysis. The present paper investigates the characteristics of two strain signals spectrum by using statistical inferences. The data used in this study are obtained from strain gauges installed on coil spring component of car suspension system driven over two different road surfaces. The coil springs are made of SAE 5160 carbon steel materials. The strain signals are explored to produce the summary statistics (i.e. root-mean-square, kurtosis, skewness etc.) and the rainflow cycle counting is performed to obtain total number of cycles and damage per cycle. Further, distribution fitting is applied to the cycle-counted strain ranges data. The results show that both signals fit well to a mixed Weibull distribution with three subpopulations.
Full Factorial Design Analysis on Mechanical Properties of Electron Beam Irradiated-Flame Retarded LDPE/EVA Composites
Authors: Tee Tiam Ting , Bee Soo Tueen , Hassan Azman , Ratnam Chantara Thevy , Sin Lee Tin , Low Chong Yu
Published: August 2015

This study aims to investigate the effect of three factors, namely alumina trihydrate (ATH), montmorillonite (MMT) and irradiation dosage on the mechanical properties (tensile strength and elongation at break) of flame-retarded LDPE-EVA composites. In this study, full factorial design analysis was used to examine the effects of factors and their combination interactions on mechanical properties. ATH is the most significant factor in affecting the tensile strength of LDPE-EVA blends due to the poor compatibility effect between ATH particles and LDPE-EVA matrix. However, MMT is the least significant factor on tensile strength of LDPE-EVA composites. ATH was the most significant in affecting the elongation at break of LDPE-EVA blends. This is because the increasing of ATH amount in LDPE-EVA matrix could restrict the mobolity of polymer chains in LDPE-EVA matrix. However, the factor of irradiation dosage was found to be insignificant in affecting the elongation at break of LDPE-EVA blends.
Porous Solid Carbon Dioxide Adsorbent Using Cost Effective Materials: A Review
Authors: Yasmin Yuriz , Mohd Noor Mazlee , Chan W.H. , Shamsul J.B. , Rahmat Azmi
Published: August 2015

Greenhouse effects were generated from anthropogenic emissions of carbon dioxide (CO2) into the atmosphere. High concentration of CO2 has recognised as major causes of global warming. In order to keep CO2 at a manageable level, adsorptions of these gases from the flue gases is necessary. Developing a low cost porous solid adsorbent as adsorption media become a great attention due to environmental and economic concerns. This paper has reviewed the cost effective materials with a suitable methods to fabricate the porous solid adsorbent. This paper also has discussed the adsorption mechanisms of CO2 on the selective cost effective materials.
The Effect of Milling Time and Sintering Temperature on Synthesis of PbTiO3 by Mechanical Alloying
Authors: Fajarin Rindang , Purwaningsih Hariyati , Nugroho Febri
Published: August 2015

PbTiO3 is one of electroceramic materials which can be applied for electronics and microelectronics due to their dielectric, pyroelectric, and piezoelectric properties. The members of PbTiO3-based ferroelectrics are widely used in multilayer, actuator and sensor capacitor. At room temperature, PbTiO3 has a tetragonal perovskite structure. In this research, PbTiO3 particles are synthesized by mechanical alloying method with variation of milling time and sintering temperature. The milling time variation is taken for 10, 20 and 30 hours. Sintering temperature variation is performed at 850, 900 and 1000°C. The powders used in the milling process are PbO and TiO2 powders. X-Ray Diffraction (XRD) and Scanning Electron Microscopy–Electron Difraction X-ray (SEM-EDX) are performed to analyze the formation of PbTiO3 phase. It is found that the synthesized powders contain 100% PbTiO3 phase for all sintering temperatures. The PbTiO3 particles have agglomeration shape with a broad particle size. The electrical properties of PbTiO3 are measured using electrical test device. Electricity test analysis shows that the synthesized PbTiO3 behaves as semiconductor-like.
Fluctuation Theorem Application on 2-D Granular Materials Configurations
Authors: Viridi Sparisoma , Nurul Khotimah Siti , Novitrian Novitrian , Widayani Widayani
Published: August 2015

Probability occurrence between two successive 2-d granular materials configuration, which are related to their entropy, can be used to check history line of the materials configurations. As an example, a well-known Brazil-nut effect will be presented. In small region it seems that this effect violates principle of minimum energy but not as the whole system, where the energy does decrease. In this work effect of temperature is considered constant since the configurations are observed in frozen states instead of dynamic or fluidized states.
Crystalline Characterization and Dielectric Constant of Barium Strontium Titanates Prepared by Solid State Reaction
Authors: Maharsi Retno , Jamaluddin Anif , Supriyanto Agus , Iriani Yofentina
Published: August 2015

Barium strontium titanate (BST) materials with the chemical formula of BaxSr1-xTiO3 had successfully made ​​by solid state reaction method. The materials were made in the form of bulk. Ba mole composition was varied in the value of x = 0,5; 0,7; and 0,9. It was varied to study the influence on crystal structure and dielectric constant. The result of crystalline characterization performed by X-ray diffractometer instrument shows that changes in the composition of x causes a shift in the diffraction angle. The lattice parameter was obtained from the refinement with the GSAS software and calculation process. Lattice parameter of BST with a value of x = 0,5 and 0,7 are a = b = c, so that the crystal structure is cubic. While the BST with a value of x = 0,9 has lattice parameter a = b ≠ c, so that the crystal structure is tetragonal. Dielectric constant measurements performed at frequency of 1 KHz by RLC-meter instrument. The highest dielectric constant ​was ​obtained at 465 on Ba0,9Sr0,1TiO3. The dielectric constant of cubic-crystal structured material is bigger than tetragonal-crystal structured material.
Thermoelectric Properties Enhancement of NaCo2O4 through Ca Atom Partial Substitution on Na Atom
Authors: Ermawan Erwin , Poertadji Suhardjo
Published: August 2015

Single phase samples of Na1-xCaxCo2O4 (with x = 0, 0.1, 0.2 and 0.3) are prepared by utilizing a solid state reaction process, and the Ca2+ substitution effect on thermoelectric properties is then observed. On the samples, the increment of Ca2+ substitution results in the increase of resistivity and thermo power properties. The Ca2+ substitution in NaCo2O4 reduces charge carriers of the samples. This phenomenon indicates that there are many holes in the samples and it is consistent with the positive sign of thermo power. It demonstrates that the Ca2+ substitution is effective to enhance thermoelectric properties.
Benefeciation of Derived Bovine Bone Waste Hydroxyapatite Obtained from Meatballs Sellers and its Characterization
Authors: Asmi Dwi
Published: August 2015

In this study, bovine bone waste obtained from meatballs sellers was utilized as novel alternative bioresource of hydroxyapatite (HA). The femur bovine bone waste in bulk form was initially deproteinized using HCl and NaOH and then followed by calcination at 500 °C and 800 °C for 5 h to obtained HA powder. The thermal stability of HA powder was monitored using simultaneous thermogravimetric analysis (TG) and differential thermal analysis (DTA). The TG/DTA result shows that the combustion of the organic component of bone, especially of collagen occured at temperature range of 174-550 °C. The phase content, type of bond present, and morphology of calcined HA powder were conducted using x-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy (SEM) respectively. The crystallinity of the HA sample shows increase with increasing of the temperature calcination. The characteristic of bands of HA and additionally peaks of carbonate ions were observed in the FTIR results and the morphologic characteristics of the HA particles shows the material is a homogeneous powder.
The Influence of Heat and Two Stages Precipitation in the Process of Natural Polymer Purification from the Byproduct of Bioethanol Process Base on Empty Palm Fruit Bunch
Authors: Hanafi Achmad , Budiman Harry , Aulia Fauzan
Published: August 2015

The biopolymer material, lignin, was recovered from the black liquor by acidification of the black liquor using sulfuric acid. Several purification techniques were carried out to produce the high purity of lignin such as gradual precipitation of lignin from black liquor (first stage: precipitation at pH 7, second stage: precipitation at pH 2) and the diluting of crude lignin by sodium hydroxide then followed by re-precipitation at different temperature. Subsequently, the impurities of lignin product resulted from each purification techniques was determined as ash content that analyzed using temperature program furnace; and the content of lignin was investigated using spectrophotometer UV-Vis. The result showed that the content of lignin of material produced from gradual precipitation was approximately 77.6%. It was higher than the content of lignin about 3.4% of material produced from direct precipitation to pH 2. In addition, the elevating of temperature from 40 to 60°C was no considerably affect to the content of lignin in precipitate produced from re-precipitation of crude lignin solution in sodium hydroxide. Nonetheless, the content of lignin of precipitate improved 15% when the temperature of re-precipitation of crude lignin solution in sodium hydroxide was raised from room temperature to 40-60°C.
The Influence of Adding Bio Inhibitor Sarang Semut (Myrmecodia pendans) to Carbon Steel API 5L Grade B in Solution of HCl 1 M
Authors: Pradityana Atria , Sulistijono Sulistijono , Shahab Abdullah
Published: August 2015

Inhibitor is generally known as one of many alternatives to control corrosion rate. These days, there is the rapid development in which finding inhibitor made from natural ingredient that is really eco-friendly. This research use type of sarang semut, Myrmecodia Pendans (MP), as bio inhibitor with concentrate level for about 0-500 mg/L and also using the material of carbon steel API 5L Grade B, and HCl 1 M as such corrosive media. The affectivity of bio inhibitor is generally known through such calibration which is called as Weight Loss, Potentiodynamic Polarization Test, Electrochemical Impedance Spectroscopy Test, and X-Ray Diffraction Test. The test results show that when it is added with bio inhibitor, there is the decreasing of corrosion rate from 109.88 mpy to 39.294 mpy in concentration level of 500 mg/L. Inhibition mechanism occurred is that there is the formation of a thin layer on the metal surface. Meanwhile, the XRD results show that there are compounds of Fe, FeCl3 and FeOCl in carbon steel API 5l Grade B.
The Effect of the Wall Thickness on Wear of an UHMWPE Acetabular Liner
Authors: Jamari J. , Hidayat A. , Saputra Eko , Anwar Iwan Budiwan , Ismail Rifky , van der Heide Emile
Published: August 2015

A larger diameter of femoral head of artificial hip joint (AHJ) is commonly recommended for increasing range of motion (RoM) and for avoiding dislocation. Unfortunately, increasing that diameter will reduce the material liner thickness of the acetabular component. The behaviour of the AHJ contact system with thickness variation of the Ultra High Molecular Weight Polyethylene (UHMWPE) acetabular liner was studied numerically and experimentally. Finite element analysis was employed for calculating contact stresses and the wear volume was measured experimentally. Numerical results show higher contact stresses with decreasing liner wall thickness. Yet, the experimental results suggest that wear decreases as well with decreasing wall thickness. These findings are important in designing an optimised acetabular liner for larger RoM.
Effect of Acidic and Basic Environment to the Degradation Behavior of PLGA Nanocapsules for Biomedical Application
Authors: Baiti Risa Nurin , Ardhyananta Hosta , El Kirat Karim
Published: August 2015

Poly (D, L lactic-co-glycolic) acid (PLGA) is very famous with its biodegradability property. In the formed of nanocapsules (NPs), it is applied as contrast agent or for drug encapsulation. To pursuit better function of PLGA NPs, a study about degradation behaviour is necessary because it is related to NPs drug release pattern. To conduct this research, PLGA NPs was prepared by emulsification solvent-evaporation method and incubated in phosphate, acetate, and carbonate buffer to observe the effect of different pH into degradation rate of PLGA NPs. The acidic environment tends to have fast destructuration with less lactate monomer produced indicating less breaking of ester bonds. While in the basic condition, the degradation is done slowly with high production of lactate. This phenomena is related to the solubility of oligomers. So, it is clear that different pH affects the degradation mechanism of PLGA NPs and it can be applied to encapsulate drug for gastric or small intestinal cancer which have acidic and basic environment respectively.
Synthesis of Sulfur-Doped Carbon Dots by Simple Heating Method
Authors: Dany Rahmayanti Handika , Sulhadi Sulhadi , Aji Mahardika Prasetya
Published: August 2015

Carbon Dots (C-Dots) was successfully prepared by simple heating method. The effect of additional elemental sulfur on the luminiscent performance of C-Dots was investigated. The preparation, chemical composition and optical properties such as absorbance and band gap energy are studied. The C-Dots were prepared with various mass sulfur 0.5-3.0 g and citric acid-urea was constant, i.e. 1.0 g and 4.0 g, respectively. This study used sulfur from natural deposit in Indonesia. The raw materials were prepared by mixing in pure water. The homogeneous solutions were heated at 225°C for 15 minutes under atmospheric pressure. The color emission of C-Dots is found in the visible light spectrum. The addition of sulfur in C-Dots phosphor caused the shifting of absorbance wavelength, i.e. 350-429 nm. By increasing mass of sulfur, the band gap energy of C-Dots decreased from 2.4 eV to 1.8 eV.
Synthesis and Fabrication of Nanoparticle-Based Thin Layer of Natural Porphyrin
Authors: Sulistyana Defi , Fonita Elvira Freditia , Utari Utari , Purnama Budi , Suryana Risa , Abraha Kamsul
Published: August 2015

Synthesis and fabrication of nanoparticle-based thin layer of natural porphyrin was reported in this paper. The natural porphyrin solutions used in the experiments were synthesized by using a process of column chromatography techniques. Then natural porphyrin thin films were deposited by spin coating methods on Cu substrate. Experiment result showed that natural porphyrin thin films composed of discrete islands. More detailed observation show that the islands were formed from smaller islands that called supra molecule.
Transition Metal (Ni, Cr)-Doped ZnO Assisted CTAB Performance on Decolorization of Organic Dyes
Authors: Noorhidayati Annisa , Philipus Raynaldi , Rachmawati Mia Putri , Saleh Rosari
Published: August 2015

A series of semiconductor nanophotocatalyst based on transition metal (Ni and Cr) doped ZnO nanoparticles have been synthesized in the presence of cetril methyl ammonium bromide (CTAB) by co-precipitation method. Samples were characterized by X-Ray Diffraction (XRD), Energy Dispersive X-Ray (EDX), Field Emission Scanning Electron Microscope (FESEM), and Brunauer-Emmet-Teller (BET) method. The resulting materials were explored for the decolorization of 4 different organic dyes (methyl orange, methylene blue, malachite green, and congo red) under UV light irradiation. The resulting materials exhibited relatively higher photocatalytic decolorization than bare Ni- and Cr-doped ZnO nanoparticles with similar doping concentration
Load Support Improvement on Superhydrophobic Surface in Lubricated-MEMS Using Numerical Investigation
Authors: Muchammad Muchammad , Tauviqirrahman Mohammad , Jamari J. , Schipper Dirk Jan
Published: August 2015

The development of micro-electro-mechanical systems (MEMS) faces a great challenge in commercial application with respect to lubrication issue recently. Short life time of lubricated MEMS is primarily caused by the failure of the lubrication. In this study, the use of superhydrophobic material applied on one or both of the opposing surfaces in lubricated MEMS was introduced to reduce this type of failure. The optimum parameter of the superhydrophobic effect that provides the greatest load support in MEMS was obtained using numerical analysis. A modified Reynolds equation combined with cavitation model was derived. The slip length model was used to address the superhydrophobic effect for the hydrodynamic analysis. It was shown that in the absence of the wedge effect, load support can be obtained using the superhydrophobic surface. In addition, the numerical analysis showed that the performance of MEMS using such surface depends on cavitation.
In Vitro Release Characteristics of Hydrophobic Breast Cancer Drug Loaded Poly Lactic-co-Glycolic Acid (PLGA) Nanoparticles
Authors: Siddiqa Akhtar Jahan , Chaudhury Koel , Adhikari Basudam
Published: August 2015

The present work focuses on the development of biodegradable PLGA nanoparticles (NPs) for controlled release of a breast cancer drug, letrozole. NPs of different drug-polymer ratio formulations (F1, F2, F3, F4) were fabricated using solvent evaporation technique. Physico-chemical characteristics of these NPs were assessed using dynamic light scattering (DLS) spectrophotometer. In-vitro drug release study was carried out over an extended period of 30 days at 37 °C in simulated physiological fluid. To evaluate the release kinetics, data was fitted to different models. NPs with various sizes and size distributions were obtained by altering the drug-polymer ratio. Zeta potential of PLGA and drug loaded NPs were found to be-29.4± 1.3 mV and-21.0±0.6 mV, respectively. The release kinetics of the drug from NPs was in good agreement with Korsmeyer-Peppas model, ensuring controlled release of the drug from the NPs. In-vitro release studies showed high correlation coefficient (R2 = 0.90) for formulation F2 and F3 up to 30 days. It is concluded that NPs with F2 and F3 formulations provide a controlled release of the incorporated drug and, therefore, hold promise to be investigated further in detail.
Montmorillonite Incorporated in Cr Doped ZnO Nanoparticles for Degradation of Organic Dyes in Water under UV Light Irradiation
Authors: Carmida Vici Tritella , Rahmawati Mia Putri , Djaja Nadia Febiana , Saleh Rosari
Published: August 2015

In this study, the photocatalytic degradation of methylene blue and congo red has been investigated using montmorillonite modified Cr-doped ZnO nanoparticles. Chromium doped zinc oxide nanoparticles were synthesized by co-precipitation method and were characterized using X-ray diffraction, Fourier-transform infrared absorption and UV-visible spectrophotometer. Furthermore these nanoparticles were explored to degradation of methylene blue and congo red in aqueous solution as model of organic pollutant under UV light irradiation. Comparison of degradation efficiency demonstrated that Cr-doped ZnO nanoparticles modified montmorillonite exhibited higher activity than pure Cr-doped ZnO.
The Effect of Sokka Clay on the Tensile and Burning Properties of rPP/Clay Composite
Authors: Diharjo Kuncoro , Suharty N.S. , Nusantara A.E.B. , Afandi Ridwan
Published: August 2015

Materials engineering, in order to achieve weight reduction and cost saving, was widely developed using plastic-based composite materials, like polypropylene (PP). As the large consumption of PP, the recycled polypropylene (rPP) was potential for producing rPP-based composites for car body panels. However, it had to have high mechanical and burning properties, and it can be achieved using clay particle as filler, like local clay from Sokka Kebumen Indonesia. The clay particle was made from rejected Sokka tile pocessed using a grinding machine and sieved for several sizes (≤74μm; 74-100 μm; 100-125 µm). The mixure of rPP/clay were pressed using a hotpress for producing the composite and its specimens were tested using Universal Testing Machine and horizontal burning test apparatus, and the fracture surfaces were observed using SEM. The enhancing of tensile and burning properties of rPP/clay composite can be performed by using the addition of Sokka-clay and smaller particle of clay. The rPP/clay composite was competitive with the commercial panel of car interior and potential to be applied as car panel material.
Performance Simulation on a Magnetorheological Valve Module Using Three Different Commercial Magnetorheological Fluid
Authors: Ichwan Burhanuddin , Mazlan Saiful Amri , Imaduddin Fitrian , Ubaidillah Ubaidillah , Zamzuri Hairi
Published: August 2015

Simulation studies on a new concept of modular Magnetorheological (MR) valve using annular-radial gap combination are discussed in this paper. This study predicts and compares the performance of MR valve module with three different commercial kind MR fluids namely the MRF-122EG, MRF-132DG, and MRF140CG. Magnetorheological effect in various types of MR fluid is analyzed using finite element method (FEM) software in term of simulation magnetic field density within the valve module. The approximated functions of permeability and field dependent yield stress for each kind of MR fluid are derived and presented in this paper as a prerequisite for simulation works. The result has shown that the highest pressure drop rating is reached by applying an MR fluid type MRF140CG, for another kind has shown smallest of pressure drop rating because of the ability to produce the achievable pressure drop highly depends on MR fluid properties.
Effect of Drying Time on Mechanical Properties of Natural Rubber Products Filled with Modified Kaolin Prepared from Latex Dipping
Authors: Harahap Hamidah , Surya Elmer , Surya Indra , Azahari Baharin , Hanafi Ismail
Published: August 2015

Alkanolamide-modifed kaolin was added into natural rubber latex (NRL) pre-vulcanization system at 70°C and the products were formed into films by coagulant dipping method. The dipped films then were dried at 120°C for 15 and 30 min. The effect of drying time on properties of NRL films such as crosslink density, tensile strength, tensile modulus, and elongation at break was observed in this study. Results showed that longer drying time improved the properties of NRL films due to the additional formation of crosslink process in the NRL films. The longer drying time swelled the particles more in matrix as confirmed by Scanning Electron Microscopy (SEM) micrograph.
Considerations on the Specific Phenomena in Metal Heating when Using Electrolytic Plasma
Authors: Hriţcu Daniel , Lupu-Poliac Margareta , Hatmanu Mihai , Baciu Elena Raluca , Baciu Constantin , Izet Ali
Published: August 2015

Discovered in 1930, metal processing by electrolysis processes in aqueous solutions, are being intensely studied starting with 1960, so that now they have a wide diversity and industrial applicability. The present paper illustrates some theoretical considerations regarding specific electrode processes of the aqueous solutions electrolysis and the I=f (U) characteristics of the Me/VGS/E electrochemical system thus establishing the forming conditions of electrolytic plasma (PE). The continuous and stable character of the deposited layer (VGS) and of the shell formed by the electrolytic plasma will contribute to the rapid heating of the metal electrode, under the influence of the three heat flows qa, ql and qs. Plasma electrolytic saturation phenomena (PES) and the formation of oxides on the metal surface (PEO), represent the two main directions of plasma electrolytic deposition (PED).
Synthesis of Nanosized Silica and Silver-Doped Silica Nanoparticles for Heat Transfer Fluids Applications
Authors: Mahmed Norsuria , Al Bakri Abdullah Mohd Mustafa , Sandu Andrei Victor , Vizureanu Petrică , Hannula Simo Pekka
Published: August 2015

The nanosized silica (SiO2) with the size less than 100 nm have successfully been prepared by hydrolysis and condensation of tetraethyl orthosilicate (TEOS) via a modified Stöber method at room temperature. The experiment was conducted by controlling the amount of the catalyst used, i.e., ammonium hydroxide (NH4OH). The morphology observation of the synthesized silica nanoparticles was conducted by using a transmission electron microscope (TEM). It was found that the size of the silica depending on the amount of the catalyst used, with homogenous size ranging from 10 to 360 nm. The doping of silver nanoparticles was done by mixing the synthesized silica with the silver ions (Ag+) solutions. Then the sample was annealed for 75 min which results in the nucleation of the silver nanoparticles less than 20 nm onto the silica surfaces, depending on the temperature used.
Researches on Structural Factor Involvement in Oral Tribology
Authors: Hanganu Stela Carmen , Hanganu Lucian Constantin , Macovei Georgiana , Potop Georgeta Lidia , Grigoras Stefan , Sandu-Ville Florin Tudose , Armencia Adina Oana
Published: August 2015

This study is focused on two ceramic materials, D.SING (Ivoclar) and VM13 (emphasis the VITA TN), frequently used in restorative dentistry practice and it comes to complete a full set of results obtained by the authors over several years of research on oral tribology with main influence on oral health. In this way there are involved more specific structural aspects of dental restorative ceramic materials quality as is shown in [1].
Testing Procedure for Timber Strength Grading
Authors: Isopescu Dorina Nicolina , Neculai Oana
Published: August 2015

Despite the variability and particularities that the timber reveals, the strength class grading system has been developed to meet the need to correlate structural design standards with quality standards for timber products. The paper presents the standardised approaches for determining the characteristic values of properties for timber products, with the purpose of classifying the material according to the strength classes system presented in European standards.
Strengthening of Masonry Walls Using Fiber Reinforced Polymer (FRP) Materials
Authors: Partene Eva , Stoian Valeriu , Bindean Andrei , Fekete-Nagy Luminita
Published: August 2015

The paper presents the behavior of masonry walls built up using ceramic blocks with hollows tested in bear state and then strengthened using FRP materials. A number of two masonry walls are subjected to cyclic in-plane horizontal loads and constant vertical loads, in order to determine the efficiency of the strengthening solutions compared with the shear resistance of the walls in bear state. Also, the experimental program is useful to observe the failure modes of the strengthened walls and also to determine if such strengthening solutions is earthquake-resistant.
Carbon Fiber Strips Retrofitting System for Precast Reinforced Concrete Wall Panel
Authors: Fofiu Mihai , Bindean Andrei , Stoian Valeriu
Published: August 2015

This paper presents the retrofitting procedure used on a precast reinforced concrete wall panel (PRCWP) in order to restore its initial load bearing capacity. The specimen used in this experimental test is one from the residential multistoried buildings constructed in Romania from the 1970 onwards. All of the characteristics of the element are from the specific era, only scaled down with a factor of 1:1,2. The element was subjected to in-plane reversed cyclic loading to simulate its seismic behavior and obtain its maximum load bearing capacity. After the test we retrofitted the element using Carbon Fiber Strips Externally Bonded (EBR) and anchored with Carbon Fiber Reinforced Polymers (CFRP) mesh. The porpoise of the paper is to compare the maximum loading bearing capacity of the unstrengthen and strengthen elements in order to compare them and examine the efficiency of this retrofitting procedure.
Formulation for Stress Intensity Factors and J-Integral Calculation by Eddy Current Testing
Authors: Harzallah Salaheddine , Chabaat Mohamed , Benissad Sekoura
Published: August 2015

In this paper, we present a method for computing the Stress Intensity Factor (SIF) and J-Integral, by measuring and testing related Eddy currents. In the process, we provide a magnetic vector based formulations for the theoretical set up. Furthermore, we provide relevant applications having theory consistent results.
The Biomaterial Relevance of Oxytocin in Some Zebrafish Studies
Authors: Plavan Gabriel , Alin Ciobica , Nicoara Mircea , Timofte Daniel
Published: August 2015

Oxytocin is a nonapeptide hormone that is involved, besides its classical functions, in linking social signals with cognition, behaviors and reward. Also, it seems to have a critical role in the regulation of brain-mediated processes that are strongly relevant to many neuropsychiatric disorders. In this way, in the present paper we will try to describe the most important and modern aspects regarding the relevance of oxytocin administration in various animal models of neuropsychiatric disorders, as well as in human patients. Also, the relevance of zebrafish studies in this context will be extensively discussed.
Characteristics Evolution of Transylvanian Sand after Biogrout Treatment
Authors: Kaltenbacher Zsolt , Máté Mátyás Istvá
Published: August 2015

This paper presents the evolution of Transylvanian sand characteristics after calcium based Biogrout treatment. By injection into the sand body of microbiological entities and certain chemicals sand is transformed into sand-stone in a short time by a phenomena called Microbially Induced Carbonate Precipitation – MICP. Triaxial testing was performed on treated samples in a confined-drained system and geotechnical and mechanical parameters were calculated. The results obtained were then compared with data from triaxial tests on the same untreated sand in the same conditions. It has been found that sand parameters suffer significant changes after Biogrout treatments in only a short period of time.
Respiratory Parameters-Based Approach to Assessing Dust Loading
Authors: Povodator Arkadi , Tsepelev Vladimir S. , Kulikova Natali
Published: August 2015

The idea of assessing the respiratory organs’ protection means has been considered, that takes into account the dust penetration coefficient and dynamics of the worker’s cardio respiratory parameters under working conditions. The individual samplers’ speed is proposed to be controlled by means of the lung ventilation while dust loading inside and outside the individual protection means is to be determined. This enables assessing them by a conventional performance factor taking into account cardio respiratory parameters as well.
Electromagnetic Sensors for Improvement of Damage Detection in Composite Materials Reinforced with Carbon Woven Fibers
Authors: Iftimie Nicoleta , Steigmann Rozina , Vizureanu Petrica , Faktorova Dagmar , Savin Adriana
Published: August 2015

This paper presents two methods for electromagnetic nondestructive evaluation (eNDE) of composite materials reinforced with carbon woven fibers using a sensor with orthogonal coils and a sensor with metamaterials lens. The samples were impacted with low energy in order to study delamination influence. The electromagnetic behavior of composite was simulated by finite-difference time-domain (FDTD) software, showing a very good concordance with eNDE tests.
Inverse Problems Using Neural Networks for Cracks Characterization in Materials
Authors: Harzallah Salaheddine , Chabaat Mohamed , Benissad Sekoura
Published: August 2015

Inverse eddy current problem using Artificial Neural Networks (ANN) approach for the localization and the classification shape of defects is considered. The task of reconstructing the cracks and damage in the plate profile of an inspected specimen in order to estimate its material properties can be described in this research work. This is accomplished by inverting eddy current probe impedance measurements that are recorded as a function of probe position, excitation frequency or both. In eddy current nondestructive evaluation, this is widely recognized as a complex theoretical problem whose solution is likely to have a significant impact on the characterization of cracks in materials .
Impact on Surface Treatment of Hydrophobic Consolidation Terracotta Ornaments
Authors: Pelin Vasile , Huțanu Ioana , Borş Eugen , Vasilache Viorica , Sandu Ion , Brânzilă Mihai
Published: August 2015

During the consolidation and rehabilitation interventions of George RaduMelidon City Library Roman, Neamţ County, a series of architectural terracotta decorations, manufactured in the second half of the century XIX, have been identified and cataloged. The current state of these decorations, made from geomaterials, requires the establishment of a technical solution which will be used to preserve, to strengthen the color, the aesthetic surface and the chromatic reintegration. Thus, the paper presents the study of four current commercial chemicals products, part of the additives hydrophobic/waterproofing group. One of the products is a water based emulsion, while the other three are organic based solvents. This study was required in order to develop an optimal treatment to preserve the old terracotta from facade of building already mentioned. The technical features that these products have in common are sealing and waterproofing by superficial coating, with an average penetration and restoration of chromatic aspect, as close to the original. CIE L*a*b* colorimetry, optical microscopy and the measure of humidity (reversible water content and related chemical) were implemented in the study of optimization of pellicle dispersion systems based on the four chemicals.
The Effects of Incenses’ Smoke on Different Types of Varnishes
Authors: Budu Ana Maria , Sandu Ion , Earar Kamel
Published: August 2015

different types of incenses are burnt during religious ceremonies in churches: frankincense, myrrh or rosin based incense. The icons from iconostasis usually are not protected by glass and they are exposed to the burning products of incense. To study the influence of burnt frankincense, myrrh and rosin based incense artificial on different types of dammar varnishes, samples of balsa wood covered with gesso, titanium white and dammar varnish were exposed to incense and were artificial aged under UV-A light for 60 hours. This paper presents the colour changes suffered by the varnishes.
Dry Lubricant Materials Deposited by Magnetron Sputtering and Friction Coefficients Evaluation
Authors: Jinga Vlad , Cristea Daniel , Mateescu A.O. , Samoila Cornel , Ursuțiu Doru , Mateescu G. , Munteanu Daniel
Published: August 2015

Because friction became a more and more important issue regarding its influences on economical trends and technological developments, causing energy waste, pollution and increased costs for production, this research is oriented towards developing new type of coatings (monolayer and multilayer) having dry lubrication properties. Presented work will refer only to friction coefficients variation for tested samples, trying to establish the direct influence of used deposition parameters and settings for obtained analyses results regarding dry lubrication properties and also trying to determine the best recipe for dry lubrication coatings depositions.
Friction and Wearing Behaviour of Sintered Composites Made from Copper Mixed with Carbon Fibers
Authors: Caliman Radu
Published: August 2015

This paper presents a study regarding friction and wear comportment of sintered composite materials obtained by mixture of copper with short carbon fibers. Sintered composites are gaining importance because the reinforcement serves to reduce the coefficient of thermal expansion and increase the strength and modulus. In case of composites form by carbon fiber and copper, the thermal conductivity can also be enhanced. The combination of low thermal expansion and high thermal conductivity makes them very attractive for electronic packaging. Besides good thermal properties, their low density makes them particularly desirable for aerospace electronics and orbiting space structures. Compared to the metal itself, a carbon fiber-copper composite is characterized by a higher strength-to-density ratio, a higher modulus-to-density ratio, better fatigue resistance, better high-temperature mechanical properties and better wear resistance. Varying the percentage of short carbon fibers from 7,8% to 2,4%, and the percentage of copper from 92,2% to 97,6%, five dissimilar composite materials have been made and tested from the wear point of view. Friction tests are carried out, at room temperature, in dry conditions, on a pin-on-disc machine. The friction coefficient was measured using abrasive discs made from steel 4340 having the average hardness of 40 HRC, and sliding velocity of 0,6 m/sec. The primary goal of this study work it was to distinguish a mixture of materials with enhanced friction and wearing behaviour. The load applied on the specimen during the tests, is playing a very important role regarding friction coefficient and also the wearing speed.
Influence of Process Parameters on the Properties of TiO2 Films Deposited by a D.C. Magnetron Sputtering System on Glass Support
Authors: Toma Stefan Lucian , Bejinariu Costica , Lucian Eva , Sandu Ioan Gabriel , Toma Bogdan Florin
Published: August 2015

In this paper it has been deposited films of titanium oxide (TiO2), on a support of glass, by a D.C. magnetron sputtering system, by varying the working pressure (p = 2∙10-3 - 6.5∙10-3mbar) of the substrate temperature on three levels. The obtained layers were investigated and characterized by optical microscopy, Scanning Electron Microscopy SEM, X-ray diffraction and Atomic Force Microscopy. It was observed that, by modifying technological parameters of the process (working pressure and substrate temperature) it is changing the initial orientation of the compounds ((100) turns into (101) or (002)). The AFM analysis has allowed the observation of the fact that the average roughness of deposited films, expressed as RMS, has increased over 98% at the increasing of sputtering pressure from 2 10-3mbar to 6.5 10-3mbar. SEM analysis showed that the density of the deposit increases with substrate temperature. The granulation of the films obtained, presents an increasing trend with the variation of process parameters.
Investigation of Copper-Silver Solders Properties in Liquid State before Amorphization
Authors: Baryshev Evgeny E. , Kostina Tatyana , Tyagunov Gennady V. , Shmakova Ksenya Yu.
Published: August 2015

The temperature and concentration dependences of kinematic viscosity of alloys of Cu-Ag system with Ag content to 99 mass % in liquid state have been studied. It has been found that heating above certain critical temperatures leads to transform the melt to equilibrium state. The kinematic viscosity of the Cu-Ag melts are extremely depend from silver content in the alloy. The new regime of amorphous ribbon production is selected. Proposed regime leads to increasing of microhardness and weld strength on 10 % and corrosion resistivity on 15 %.
Effect of TiO2 on Duck Eggshell Membrane as Separators in Supercapacitor Applications
Authors: Dahlan D. , Sartika N. , Astuti  , Namigo E.L. , Taer E.
Published: August 2015

A study concerning the effect of TiO2 on duck eggshell membrane as separator in supercapacitor applications. Concentration of TiO2 on duck eggshell membrane are 1 %wt, 5 %wt and 10 %wt respectively. Construction capacitor cell is shaped sandwich system. Membrane separator placed in the midst of the two carbon electrodes containing H2SO4 solution. From the micrograph Scanning Electron Microscopy (SEM), it observed that TiO2 particles in all samples are uniform in size. At concentration of 1 %wt, TiO2 particles covered all fiber of duck eggshell membrane, but not many pore is formed while at concentration of 5%, the TiO2 particles fill the pores between the fibers, thus causing the pores between the fibers get smaller and multiplied in number. However, if the TiO2 particles added is the more than 10 %wt, the particles will actually cover the pores between the fibers of the membrane. Characteristics of the capacitor was measured by using Edaq cyclic voltameter. Maximum value of specifics capacitance (Csp) was 2.3 F / g, with current 0.007 mA and voltage of 0.002 V. This value occurs at a concentration of 5 wt% TiO2 on the charging time for 20 seconds.
Enhancement of Lithium Battery Performance by Thickness Anode Film Modification
Authors: Fajaryatun Rani Cahyani , Sukardi Therecia Wulan , Jumari Arif , Purwanto Agus
Published: August 2015

A lithium battery was composed of anode, cathode, and separator. The performance of lithium battery was influenced by the thickness of film, the composition of material, and the effect of surfactant and binder. This research investigated the effect of the anode film thickness to the electrochemical performances of lithium battery. Mesocarbon microbeads (MCMB) and lithium iron phosphate (LiFePO4) were used respectively as anode and cathode. Mesocarbon microbeads, carbon black (conductive agent), polyvinylidene fluoride (PVDF) as a binder and N-methyl-2-pyrrolidone (NMP) as a solvent were mixed well to produce slurry. The slurry were then coated, dried and pressed. The anode had various thickness of 50 μm, 70 μm, 100 μm, and 150 μm. The cathode film was made with certain thickness. The performance of lithium battery was examined by Eight Channel Battery Analyzer, the composition of the anode sample was examined by XRD (X-Ray Diffraction), and the crystal structure of the anode sample was analyzed by SEM (Scanning Electron Microscope). The research showed that the thickness of anode film of 100 μm gave the best performance. The battery performance decreased if the thickness was more than 100 μm. The best performance of battery voltage were between 3649 mV and 3650 mV.