bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect on the Grinding Performance by the Different Elements of the Auxiliary Material
Authors: Li Shi Lei , Lin Tao , Wang Zhi , He Xin Bo
Published: February 2014

The effect of different elements of the auxiliary material on the grinding performance was studied in this paper. Through the grinding experiment, the grinding performance of the abrasive tool can be obtained. It shows that the grinding rate decreased until its content reached to16% following with increasing the NaHCO3 content. And the abrasive removal rate reduced, while the grinding efficiency was lower than the abrasive tool without adding NaHCO3. When ZnO content was reached 3%, the grinding rate increased by 43.48% and the grinding efficiency was also improved; while continue to increase its content, the abrasive`s self-sharpening were reduced, which resulting the grinding rate declined. As the NBR (nitrile rubber) content increased, the grinding rate improved and while its content was 20%, the grinding rate increased by 45.93% and the abrasive removal rate reached to the lowest, but the grinding efficiency reduced more. While continue to add NBR, the grinding rate will decrease.
Influence of Minimum Quantity Lubrication on Cutting Force and Tool Wear during Machining of GH4169
Authors: Zhou Ji Lie , Sun Zhong Hao , Wu Yun Xian , Yu Yang
Published: February 2014

MQL system is introduced in this paper to verify the influences on the tool wear and cutting force that brought by MQL (minimal quantity lubrication) for high-temperature alloy. The system utilized various pressures that are caused by the compressed air flowing through the decrescent areas to absorb the liquid from the reservoir tank, and then the liquid was transported to the nozzle which could spray the liquid on the workpiece for cooling and lubrication. The results shown that MQL had an obvious advantage over dry cutting and traditional cooling methods; it could effectively reduce cutting forces and improve the tool life expectancy as well as processing quality and efficiency. The proposed method also had some other positive characteristics, such as the less dosage of cooling fluid and the environmental-friendly. It also can be applied to the processing of difficult-to-cut materials with a wide range of prospects.
Three-Dimensional Non-Linear FE Analysis of Shear Stress Distributions in Adhesively Bonded Joint
Authors: He Xiao Cong , Wang Yu Qi
Published: February 2014

The aim of this work is to investigate the shear stress distributions across the adhesive layer thickness in single-lap adhesively bonded joint. The shear stress distributions of a single-lap adhesively bonded joint have been investigated using the three-dimensional linear static and non-linear quasi-static finite element method. The analysis results indicate that there are significant differences between the linear static and non-linear quasi-static analyses. The results also show that the maximum value of the shear stress component S13 occurs at the centre line while the maximum of the shear stress components S12 and S23 occur near or at the left-rear corner of the adhesive layer.
Reinforced Round Timber Joints under Static and Cyclic Loading
Authors: Lokaj Antonín , Klajmonová Kristýna , Křivý Vit
Published: February 2014

Aim of this article is in presentation of results of static and cyclic tests of round timber bolted joints with inserted steel plates. At first, timber specimens were tested without reinforcement. Based on static tests results, mechanical reinforcement methods were proposed and tested: using modified washers and boost with screws. Rate of improvement in tensile strength was established for used reinforcement method. Static tests in tension were carried out on pressure machine EU 100 in laboratory of the Faculty of Civil Engineering VŠB-TU Ostrava. Round timber joints multi cyclical dynamic (fatigue) tests in tension were made in laboratory of ITAM AS CR Prague and in TRI Žilina.
Productivity Analysis of Fractured Well in Tight Oil Reservoir
Authors: Xu Yong Gao , Li Xian Wen , Liao Rui Quan , Xu Dong Jin
Published: February 2014

Hydraulic fracturing is an effective technique for increasing the productivity of wells producing from low permeability and tight oil formations (Reservoir permeability is less than 0.1mD). By establishing the seepage model of vertically fractured well, concerned on the threshold pressure gradient and stress sensitivity of the reservoir, the mathematical model has been solved and the productivity equation of vertically fractured well has been obtained in the paper. The productivity analysis shows that the bigger the threshold pressure gradient, the lower the productivity of oil well; the stronger the stress sensitivity, the lower the productivity, besides, the initial productivity of oil well increases with the increasing length of the fracture, but the increase rate tends small.
Research Status and Development Trend of Steel-Bamboo Composite Structure
Authors: Wen Yu , Xu Ke Ke , Tang Jing , Li Yu Shun
Published: February 2014

Steel structure system is the combination of specific fitting composites which are bamboo veneer and cold bending thin-wall steel, it is a high efficiency and energy-saving building structure system. It contains the advantages of both steel and bamboo, giving full play to the advantages of light weight, high strength, seismic.
Energy Assessment for China Nuclear Waste Based on Energy Harvesting
Authors: Guo Xiao Gang
Published: February 2014

Chinas nuclear waste disposal is Developing country in the world in both technology and management mode, especially the spent fuel final disposal plan is the weaknesses. After a brief overview of the China nuclear waste disposal, the article focuses on analysis nuclear waste management experience. China model characteristics include perfect planning and system, the concept of absolute safety and requirements, and in the whole process of the public participation and dialogue. China model brings us a lot of valuable enlightenment for nuclear waste disposal and management in other country.
Thermal Class Evaluation of Glass Net Used for Transformer
Authors: Zhang Hui , Yu Tao , Sheng Jian Feng , Yu Qiong
Published: February 2014

This work predicts the Thermal class of glass net for transformer. The rapid thermal ageing test method was applied to estimate thermal class of glass net.
Green Performance Assessment of Power Battery for Electric Vehicle Based on Multi-Objective and Multi-Stage
Authors: Gao Yang , Li Yu Ke , Mo Xing Bo
Published: February 2014

Green performance assessment of power battery is a whole life cycle process, which integrates Environment (E), Resource (R), Technology (T) and Cost (C) objectives considered as evaluation of multi-objective and multi-stage. According to definition of Green Product, the assessment model of multi-objective and multi-stage for power battery was built. The green utility function is proposed, by which the evaluation data of indices are changed uniformly into range of (0, 1) according to the assessment standard initialized as 0.5. The synthesis calculation method is given, which remains all the messages in the assessment. Finally, the green performance comparison between lithium-ion battery and nickel metal hydride battery proves the assessment method and process.
Effects of Heat Slug Shapes on the Heat Dissipation of High Power LED
Authors: Sauli Zaliman , Vairavan Rajendaran , Retnasamy Vithyacharan
Published: February 2014

High power light emitting diodes are currently challenged by thermal issue of high heat generation which limits the reliability and efficiency. Each component in the LED package has a significant role in heat dissipation. In this paper, a simulation study was done to scrutinize the influence of heat slug shape on the heat dissipation of single chip LED package using Ansys version 11. Two types of heat slug shapes, rectangular and cylindrical were used. The analysis was carried out under natural convection condition at ambient temperature of 25°C. Simulated results indicate that rectangular shape heat slug exhibits better heat dissipation.
Study on Duel Photo-Curing Properties of Quaternary Ammonium Salt Ionic Liquid as Photobase Generator
Authors: Zhong Rong , Xiong Rong Hua , Pang Lai Xing
Published: February 2014

Two quaternary ammonium tetraphenyl borates salt photobase generators were synthesized using 2-naphthoymethylene as chromophores, and triethylene diamine, pyridine. Their UV curing properties were studied in different environment. The results showed that their photolysis kinetics was of the first order reaction. Quaternary ammonium salts with the UV irradiation can initiate free radical photopolmerization and cure the epoxy resin.
Influence of Ionic Surfactants under Ultrasonic Irradiation to Reduce the Particle Size of Mechanically Alloyed La1-XSrX Fe0.5Mn0.25Ti0.25O3 Powders
Authors: Hafizah Mas Ayu Elita , Manaf Azwar , Soegijono Bambang
Published: February 2014

In this study, nanoparticles La1-xSrxFe0.5Mn0.25Ti0.25O3 particles were prepared by two successive methods: the mechanical alloying (MA) with the successive sintering and the deagglomeration of MA powders in the demineralized water containing surfactant under ultrasonic irradiation. It is shown that MA powders have coarser particle size of a slightly less than 6 micron in average. Additionally, the particle size distribution was relatively broadening which indicates a large size variation in particle sizes. As MA powders were dispersed in the demineralized water and irradiated by a 40 KHz ultrasonic wave for 5 hours the particle size distribution was improve significantly, it has a narrow particle size distribution with a mean particle size almost 180 nm. The particle has crystallite with mean size 20-26 nm subject to XRD line broadening analysis. Thus, the particles can be called nanoparticles clusters. The study also indicated the breakup of nanoparticle cluster was no longer effective in a prolonged ultra sonication time and yet reagglomeration was obvious. However, the latter was not occurred in a disperse media containing surfactants. In this study, four types of surfactant were used and their influences to the particle sizes were evaluated. According to this study, the four types of surfactants could reduce further the particle size but in different pathways. Sodium Dodecyl Sulphate (SDS) as anionic surfactant reduced the sizes of nanoparticle clusters to almost 180 nm by one step ultra sonication. While cationic, non-ionic and amphoteric surfactants promoted the gel formation in the first place, the nanoparticle clusters were then obtained after an additional heating to breaking the gel form to dry powders. The present of gel was due to stabilization process of the particle to avoid any re-agglomeration between each fine particle. In this paper, we discussed a systematic material preparation towards nanoparticles clusters and the mechanism as well as influence of surfactants in particle size reduction for LSMFTO powders.
Covalent Functionalization of Amino Group onto Carbon-Based Magnetic Nanoparticles Using Pulsed-Powder Explosion Technique
Authors: Saraswati Teguh Endah , Tsumura Shun , Nagatsu Masaaki
Published: February 2014

In order to enhance the treatment processing for powder of nanoparticle, we developed a modified setup using an inductively coupled radio frequency plasma with a pulsed explosion technique. Applying a negative pulsed bias voltage of -1 kV to the substrate stage in 15 seconds with a repetition frequency of 1 kHz and a duty ratio of 50 % in ammonia plasma, a significant increase of N 1s peak intensity in the X-ray photoelectron spectroscopy spectra was observed. The intensity of N 1s peak treated in the pulsed-biasing system raised both about four times higher than those of the particles treated without bias. After plasma treatment, the amino group was suggested to be covalently functionalized onto the nanoparticle surface and quantitatively examined by chemical derivatization. The amino group population attached onto treated nanoparticles was determined about 8.2 x 104 molecules per nanoparticle, roughly four times higher than that of particle without biasing which was about 1.9 x 104 molecules per nanoparticle. The surface structure analysis by a high resolution-transmission electron microscopy showed no significant damages were found on the nanoparticles, indicating that the present technique is suitable mainly for surface modification of powder materials without bringing any damages on their structural and morphological surface.
Preparation of Activated Carbons from Coconuts Shell for Pb (II) Adsorption
Authors: Yusmartini Eka , Setiabudidaya Dedi , Ridwan Ridwan , Marsi Marsi , Faizal Faizal
Published: February 2014

The purpose of this study is to prepare activated carbon from coconut shell to be used as an adsorbent for heavy metals. The coconut shell was carbonized at a temperature of 700°C and the resulting carbon is finely milled and sieved through No 200 mesh. Sulfuric acid is used as an activator for this process. The characteristics of the resulting activated carbon were tested and the results are as follows: moisture content 1.641%, ash content of 0.554%, iodine adsorption of 960.21 mg/g and the adsorption of methyl blue 212.1 mg/g. The small particle size of the activated carbon increases the surface area measured using BET method to 398.721 m2/g. Adsorption kinetic and adsorption efficiency of the activated carbon on Pb by batch method follow pseudo second-order equation order model with adsorption capacity at equilibrium equal to 24.491 mg per g Pb (II) adsorbent.
The Effect of Variation Concentration Nd3+ Ions on Physical and Optical Properties of TZBN Glass
Authors: Nurliana Evi , Riyatun Riyatun , Rahmasari Lita
Published: February 2014

This study aims to determine the optical and physical properties of TZBN:Nd glass with the composition (mol%) 60TeO2-2Bi2O3-(34-x)ZnO-4Na2O-xNd2O3 with variation of doping x = 0.5; 1.0; 1.5; 2.0. Fabrication has been done by using the melt-quenching technique. Characterization of tellurite glass covering density, refractive index and absorption spectrum of glass. Density of glass have been measured using the Archimedes method. Refractive index of glass have been measured using the Brewster angle at wavelength 746.191 nm. Absorption spectrum measurements using UV-Vis-NIR spectrophotometer Perkin Elmer Lambda 25 in the region of 200-1100 nm. The results of characterization show that density / physical characteristics of glass did not increase when the concentration of ions Nd3+ to TZBN:Nd glass increased. The refractive index of glass will increase as the concentration of ions Nd3+ to TZBN:Nd glass increased. Based on the results of UV-Vis-NIR spectroscopy measurements shows that there are nine significant spectra have been observed in the region of 200-1100 nm, such as at a wavelength of 431 nm, 474 nm, 515 nm, 527 nm, 585 nm, 684 nm, 749 nm, 805 nm, and 878 nm and the highest absorption peak is at a wavelength of 585 nm.
Gas Sensing Using Static and Dynamic Modes Piezoresistive Microcantilever
Authors: Nuryadi Ratno , Aprilia Lia , Aisah Nuning , Hartanto Djoko
Published: February 2014

A microcantilever has attracted interest in an application of high sensitivity sensor for chemical, physical, or biological objects. In this paper, we investigate a possibility of a piezoresistive microcantilever for gas sensing using a static and a dynamic modes operation. The gas used here is a liquefied petroleum gas (LPG). The measurement was performed by a Wheatstone bridge circuit in order to measure the microcantilever deflection or resonance frequency shift of the microcantilever vibration. The result shows that in the static mode, an output of Wheatstone bridge circuit, which attributes to the microcantilever deflection, changes due to the gas detection. For the dynamic mode, a voltage of peak-to-peak, which represents the microcantilever vibrations, decreases with increasing the gas flow time. This occurs due to the resonance frequency shift caused by the addition of gas molecules on the microcantilever surface. These results indicate that the developed system can be used as the gas sensor.
Structural Studies of 1,3:2,4-Dibenzylidene Sorbitol Gels
Authors: Takeno Hiroyuki , Kuribayashi Yuta
Published: February 2014

We investigated the self-assembled structures of 1,3:2,4-dibenzylidene sorbitol in different solvents by using synchrotron small-angle X-ray scattering (SAXS) and optical microscopy. Structures of a turbid gel and a nearly transparent gel were compared in this study. Although the sol-gel transition temperatures of both gels showed almost the same values, their structures were largely different. The optical microscopy observation showed that a spherulite structure was formed for the turbid gel, but for the transparent gel no distinct structure was seen in the scale of optical microscopy. The SAXS experiments reveal that the transparent gel was composed of fibrillar aggregates with the radius of gyration Rc of 38-40 Å in the cross-section. The increase in temperature in the gel state caused decrease in the fiber density with keeping the fiber thickness almost unchanged, and the fibrillar aggregates were completely dissolved above the sol-gel transition temperature. The cross-sectional size became more homogeneous, as the temperature approached the sol-gel transition temperature.
Experimental Studies of Thermo-Induced Mechanical Effects in the Main-Chain Liquid Crystal Elastomers
Authors: Supardi Supardi , Harsojo Harsojo , Yusuf Yusril
Published: February 2014

Liquid crystal elastomers (LCEs), either side-chain LCEs (SCLCEs) or main-chain LCEs (MCLCEs), possess a combination of LC and elastic properties, and are expected to be used as artificial muscles. We experimentally investigated the thermo-induced mechanical effects showed by MCLCEs with four different crosslinker concentrations, i.e., 8%, 12%, 14% and 16%. The samples were heated up to the critical temperature and the images were recorded. The samples made the contraction in direction parallel to the director and the expansion in direction perpendicular to the director. Drastic changes occured when approaching the critical temperature, the greater the crosslinkers concentration the bigger the maximum contraction and expansion. The shape anisotropy expression showed that heating up to the critical temperature caused the system no longer in anisotropic state.
Fabrication and Characterization of Ferroelectric Thin Film BaxSr1-xTiO3 for Application in Light Intensity Detector
Authors: Jamaluddin Anif , Susilowati Erna , Budiawanti Sri , Iriani Yofentina
Published: February 2014

Ferroelectric thin film devices have been demonstrated using BaxSr1-xTiO3 (BST) as a light intensity detector. Various compositions of BST (x=0.7, 0.8 and 0.9) were prepared using Chemical Solution Deposition method. Solution of barium acetate, strontium acetate, titanium (IV) iso-propoxide in a mixture of acetic acid and ethylene glycol was spin-coated onto a silicon substrate. The BST film was annealed at 800°C. The microstructure and the crystalline characterization of BST were studied using X-Ray Diffraction (XRD) pattern with General Structure Analysis System (GSAS) refinement. The film thickness was measured using Scanning Electron Microscopy (SEM). The response of BST film to source of light intensity was investigated with IRC meter and resonator coupling. The results show that the resistance of a thin BST film decrease as the intensity of light increase. On resonator coupling, VOUT shows a slight increases as the intensity of light increases.
A Theoretical Study on Electron Tunneling Current in Isotropic High-κ Dielectric Stack-Based MOS Capacitors with Charge Trapping
Authors: Noor Fatimah A. , Khairiah Khairiah , Mikrajuddin Abdullah , Khairurrijal Khairurrijal
Published: February 2014

Electron tunneling current in an isotropic metal-oxide-semiconductor (MOS) capacitor with a high-κ dielectric stack has been studied by considering the effect of charge trapping. The transmittance was analytically calculated by employing an Airy-wavefunction approach and including a coupling term between the transverse and longitudinal kinetic energies which is represented by an electron phase velocity in the gate. The transmittance was then applied to obtain tunneling currents in isotropic n+poly-Si/HfSiOxN/trap/SiO2/Si (100) MOS capacitors for different electron gate phase velocities and trap depths and widths. The calculated results show that the transmittance and tunneling current increase as the electron gate velocity decreases. In addition, the increase in the trap depth and width enhances the tunneling current.
Modeling of Drain Current in Armchair Graphene Nanoribbon Field Effect Transistor Using Transfer Matrix Method
Authors: Suhendi Endi , Noor Fatimah A. , Kurniasih Neny , Khairurrijal Khairurrijal
Published: February 2014

Drain current in an armchair graphene nanoribbon field effect transistor (AGNRFET) has been quantum mechanically modeled. The transfer matrix method (TMM) was employed to obtain the electron transmittance, and the obtained transmittance was then utilized to calculate the drain current by using the Landauer formula. The calculated results showed that the drain current increases with the gate and drain voltages. It was also shown that the threshold voltage for the device is around 0.3 V. In addition, the AGNR width influences the drain current of AGNRFET.
A Simple Way of Producing Nano Anatase TiO2 in Polyvinyl Alcohol Fibers
Authors: Harsojo Harsojo , Triyana Kuwat , Sosiati Harini
Published: February 2014

A simple way of producing nanoTiO2 on fiber polyvinyl alcohol (PVA) has been done using solution anatase TiO2 micro powder as a solution for electro spinner machine. The process relies upon the mixing of TiO2 and PVA in deionized water before converted it into fiber. The result shows that before and after heat treatment at 300°C, the electrospinning process are able to carry 60% TiO2 in the anatase phase and to reduce the fiber size and carry the crystalline in nanosize showing a potential way of making fiber carrying nanocrystalline anatase.
Anode Buffer for Organic Devices Composed of Gold Nanoparticles Prepared by Ark Plasma Deposition
Authors: Wang Dan , Yukitake Noriaki , Fujita Katsuhiko
Published: February 2014

Gold nanoparticles (Au NPs) with mean size of 1 nm were placed on an indium tin oxide (ITO) electrode by ark plasma gun. The hole injection at ITO/organic semiconductor was significantly enhanced by the NPs. Though the hole current was unstable upon the voltage scan, it can be substantially stabilized by the insertion of hyper-branched polystyrene (HPS) thin layer between ITO and Au NPs. The work function of ITO electrode was also increased by NPs. The ITO/HPS/Au NPs structure was applied to the anode of an organic solar cell (OSC) with a bulk heterojunction active layer. The power conversion efficiency was significantly higher than that of OSC without anode buffer layer and almost comparable to that with a representative buffer material.
Influence of Mass Ratio of Aquadest and TTIP on the Synthesis of TiO2 Nanoparticles to Improve the Performance of DSSC with Beta-Carotene as Sensitizer
Authors: Ardhani Nafi'ah , Supriyanto Agus , Yuwono Akhmad Herman , Suryana Risa
Published: February 2014

TiO2 nanoparticles have been successfully synthesized using the sol-gel method with main materials of titanium tetraisopropoxide (TTIP) and HClO4 solutions. Mass ratios (Rw) of aquadest and TTIP were 0.85, 2.00, and 3.50 which were going to be investigated in crystallization of TiO2 phases. Pre-heating was performed on TiO2 at 60°C for one day then it was annealed at 150°C for 3 hours. The DSSC structure was formed by using the synthesized-TiO2 as semiconductor material and beta-carotene as dye sensitizer. The x-ray diffraction (XRD) spectrum indicated that TiO2 peaks had anatase phases on crystal orientation of (101), (004), and (200) while TiO2 of rutile phase only appeared on orientation of (211). The highest intensity for all Rw was dominated by (101) anatase phase. From XRD spectrum data of (101) peak, the Scherrer’s method predicted that crystal size of TiO2 was 3.48 nm, 4.36 nm, and 4.47 nm for Rw of 0.85, 2.00, and 3.50, respectively. The Tauc’s method was applied on the UV-Vis data that predicted the bandgap energy (Eg) of TiO2 for Rw of 2.00 (Eg=3.14 eV) was higher than Rw of 0.85 (Eg=3.02 eV) and 3.50 (Eg=3.04 eV). The I-V characteristic calculation of DSSC structures were obtained that the efficiency optimum is 0.01% for Rw of 2.00. It is considered that bandgap energy value correlated to stability of Ti-OH bonds that caused the exited-electrons are easily injected to conduction band of TiO2. The performance of DSSC using the synthesized-TiO2 which consists of anatase and rutile can be improved about ten times compared to that using the pure-TiO2 rutile.
Organic-Inorganic Solar Cell Based on Sprayed MEH-PPV/ZnO Nanorods Layers
Authors: Mahmoud Fawzy A. , Shehata Adel B. , Mohamed Hagar , Magdy Wafaa
Published: February 2014

Zinc oxide layer have been prepared by spray pyrolysis technique. The effect of substrate temperature on structural and optical properties of the prepared layer has been investigated. XRD patterns show that ZnO layers are polycrystalline with (002) plane as preferential orientation. FESM images show that ZnO layeres consist of nanorods. Semi-conducting MEH-PPV polymer, which prepared in our lab, was dissolved in THF and sprayed on glass and KBr substrates at 150 oC with two different carrier gases. Organic-inorganic solar cell from MEH-PPV with ZnO nanorods layers was constructed, characterized and its efficiency was calculated.
The Formulation of Phonon as the Result of Second Quantization of Crystalline Lattice Vibration Using Wave Functional Method
Authors: Hermanto Arief
Published: February 2014

Phonon is undoubtedly one of the most important concepts in the physics of materials. Phonon is the result when we quantize vibrational field. Whereas Schrodinger’s wave function method is the most popular and intuitive method in doing the first quantization, one usually uses Heisenberg’s operator method in the second quantization. We feel that there is a methodological and pedagogical discontinuity here. So in this paper we will use Schrodinger’s wave functional method to quantize the lattice vibration to produce phonons. Wave functional is difficult due to the nondenumerably infinite number of dimensions of its domain. In this paper we will approximate this infinity through the discrete nature of crystalline lattice so that phonon can be represented by wave function with many variables
Effect of Oxygen Plasma on the Optical Properties of Monolayer Graphene
Authors: Santoso Iman , Singh Ram Sevak , Gogoi Pranjal Kumar , Asmara Teguh Citra , Wei Da Cheng , Chen Wei , Wee Andrew T.S. , Pereira Vitor M. , Rusydi Andrivo
Published: February 2014

The significant alteration of absorption (A) of monolayer graphene under mild oxygen plasma exposure has been observed. The first important effect is the reduction of the excitonic resonance peak at 4.64 eV. Secondly, in the near infrared range, A is gradually suppressed below an exposure-dependent threshold in sense that A << A0. Quantity A0 (given by πα and α is the fine structure constant) denotes constant absorption and relates to universal optical conductivity σ0. The suppression of A0 can be thought as the weakening of electron-hole interaction as displayed by the reduction of the excitonic resonance peak at 4.64 eV. The weakening of this interaction is due to the disorder introduced by the oxygen plasma exposure.
Ground Shear Strain and Rate of Erosion in the Coastal Area of North Bengkulu, Indonesia
Authors: Farid Muhammad , Sri Brotopuspito Kirbani , Wahyudi Wahyudi , Sunarto Sunarto , Suryanto Wiwit
Published: February 2014

North Bengkulu district has an area prone to earthquakes, because this area is very closed to the Sumatra subduction zone to the Eurasian tectonic plate. Coastal area in this region is experiencing with the very fast erosion. This is thought to have relation with earthquake-prone zones. This study aims to find the relationship between Ground Shear Strain (GSS) and rate of erosion in the coastal area of North Bengkulu. The data of coastal erosion rate was obtained by overlaying shoreline in 1947 and 2012. The GSS can be obtained by multiplying Seismic Vulnerability Index (SVI) and Peak Ground Acceleration (PGA) values around the shoreline. Seismic Vulnerability Index was obtained by processing microseismic data acquired using three component in short period of seismometers. The PGA was obtained from the historical earthquake and calculated by using Fukushima-Tanaka equation. The results show that the value of GSS varies between 0.0001 to 0.0055, and the SVI values is ranging from 1.2 to 16.1. In addition, we estimated that PGA value is 92 to 120 and the rate of erosion between 3.6 up to 5.8 m/yr. GSS value for each type of coastal is 0.00046 for the fine sandy beach flat, 0.0043 for flat coastal muddy, 0.0001 for flat rocky beaches, 0.0006 for sandy beaches to rugged, 0.0003 for steep rocky lava beach, 0.0014 for steep rocky coast of for clay, 0.0011 for bertufa steep sandy beach stones, and 0.0014 for the steep rocky shore tuffaceous clay. It is found that the GSS value depends on the type of coastal. In this case, flat coastal muddy show highest effect on the GSS. Both SVI and GSS can be estimated to be a quadratic relation to the erosion rate.
Development of Hydrocracking Catalyst Support from Kaolin of Indonesian Origin
Authors: Rahayu Endang Sri , Samadhi Tjokorde Walmiki , Subagjo Subagjo , Gunawan Melia Laniwati
Published: February 2014

The global shift of petroleum refinery towards heavier crude oils means an increasing demand of hydrocracking catalysts. This work studies the conversion of a kaolin originating from the Bangka island in Indonesia into a hydrocracking catalyst support consisting of zeolite-Y and amorphous alumina-silica phases. After a beneficiation process combining controlled settling and adsorption of the kaolin suspension in water with the addition of 125 ppm of 0.01% polyacrylamide solution as flocculant and 156 ppm of 0.1% calcium chloride solution as the adsorbent, the kaolinite phase content is increased from 63.6 to 74.3 %-mass. After spray drying, the kaolin is calcined at three temperatures for 2 hours each, producing calcined kaolin phases K700C at 700 °C, K1013 at 1013 °C, and K1050C at 1050 °C. Temperatures of calcination for obtaining calcined kaolin phases is determined based on result of DSC/TGA. Synthesis of zeolite-Y is done by mixing varying proportions of these three calcined kaolin products, and zeolite-Y crystal seeds. These mixtures are aged at room temperature for 11 hours prior to reaction in a hydrothermal condition at 93 °C for 15-21 hours. The best calcined kaolin composition is found to be K700C : K1013C : K1050C = 10:85:5 (%-mass), resulting in a zeolite NaY purity of 86-88 % as characterized by X-ray diffraction (XRD), average ratio of SiO2/ Al2O3 of 5.35, mean pore diameter of 23.1 Å, specific surface area of 186 m2/g, and a total pore volume of 0.107 mL/g as measured by N2 adsorption. In a parallel manner, a series of amorphous silica-alumina (ASA) synthesis experiments is done to identify the best metakaolin calcination temperature and metakaoline activation pH. These are found to be 527 °C and 8.0, respectively, producing an ASA product with a 65 %-mass amorphous phase content as estimated by XRD data processing. To prepare the hydrocracking catalyst support, the zeolite NaY is added into the ASA-forming metakaolin sol at a pH of 8.0, aged for 8 hours at 50 °C. An initial morphological characterization of the obtained zeolite-ASA composite catalyst support suggests a good dispersion of the smaller zeolite NaY particles in the ASA microspheres.
High Compressive Strength of Palm Oil Empty Fruit Bunches (Elaeis guineensis) Composites
Authors: Sriyanti Ida , Agustina Lina , Selviana Iftita , Marlina Leni
Published: February 2014

Simple mixing and hot pressing methods were used to make high strength and light-weight composite from oil palm empty fruit bunches (OPEFB) using PVAc as an adhesive and silica nanoparticles as a filler. The mechanical strength of the composite was examined in term of compressive strength. The simple mixing method was used to mix composition with PVAc and silica nanoparticles. Silica nanoparticles were added as filler. Hot pressing method was used to press the mixed composites at a pressing pressure of 85 MPa, pressing temperature of 150 °C, and pressing time of 20 minutes. The optimum composition in term of compressive strength for the strongest composite had a mass ratio of OPEFB/PVAc of 13 : 2 and obtained a compressive strength of 82,88 MPa. Higher compressive strength of 100,39 MPa was obtained by adding the silica nanoparticles at a mass ratio of OPEFB/PVAc/silica nanoparticles of 13 : 2 : 0,75. At pressing pressure of 100 MPa, pressing temperature of 150 °C, and pressing time of 20 minutes, we found compressive strength of 115,35 MPa. Data analysis of XRD showed that the used silica nanoparticles were in amorphous phase or had broad pattern. The compressive strength data showed that the composites were stronger than the composites made by Masturi and Kumagizuri, and also stronger than the ordinary wood-based composites. Thus, the composites are feasible to be used to replace wood-based composites, especially in furnishings.
Properties of the Treated Kenaf/Polypropylene (PP) Composites
Authors: Sosiati Harini , Supatmi Supatmi , Wijayanti Dwi Astuti , Widyorini Ragil , Soekrisno Soekrisno
Published: February 2014

Untreated and treated kenaf fibers were used in the fabrication of kenaf/polypropylene (PP) composites. The ratio of the fibers as fillers and PP as matrix was 40:60 in wt%. Small amounts of maleic anhydride grafted polypropylene (MAPP) were added as a coupling agent. Fourier transform infrared (FTIR) spectroscopy was used to estimate the cellulose contained in the treated kenaf fibers. A flexural test of the composites was conducted by referring to JIS (A 5905, 1994, Fiberboards). A composite with alkali-treated fiber had better properties (modulus of rupture (MOR) and elasticity (MOE), absorbed water and thickness in swelling) than that with a combination of steam-alkali and alkali-bleaching treated fibers, and untreated fibers. The dispersion characteristic of the fibers within the polymer matrix has been suggested as one of the significant factors affecting the composite properties. These composites are classified as medium density fiberboard (MDF, JIS, type 30 and 25).
Boron Carbide B25C and B8C18 Synthesized Using Boric Acid-Glucose and Boric Acid-Active Carbon at Low Temperature without Coreductor Materials
Authors: Toana Mufirah Cahya Fajrah , Soegijono Bambang
Published: February 2014

This study examines the formation of Boron carbide with a wide homogeneity range B8C18 and B25C, from boric acid-glucose and boric acid-active carbon as precursor materials. The samples was analysed by means of X-ray diffraction and Fourier Transform Infrared spectrometer. X-ray diffraction pattern was analysed by GSAS software. X ray diffraction pattern of B8C18 shows peaks at 27o, 39o, 45o, 65o and 79o, orthorhombic crystal system and lattice parameters a = 13.640 Ǻ, b = 7.8500 Ǻ and c = 12.910 Ǻ and space group P212121, whereas for B25C sample show peaks at 2θ angle 28o and 40o, tetragonal crystal system, and the lattice parameters a = b = 8.753 Ǻ and c = 5.093 Ǻ and space group P-4 2 m. FTIR results show that for B8C18 have absorption bands with B-C bond at 1196.5 cm-1, 0-H 3216.7 cm-1 and B-O at 1477.1 cm-1, whereas the formation B25C have absorption bands with B-C bond at 1195.1 cm-1, O-H 3216.7 cm-1 and B-O 1460.8 cm-1.
Quantitative Bump Height Analysis in ENIG Using Design of Experiment
Authors: Sauli Zaliman , Retnasamy Vithyacharan , Ehkan Phaklen , Fuad Fairul Afzal Ahmad , Yeow Aaron Koay Terr
Published: February 2014

Flip chip technology has grown by leaps and bounds and is getting even smaller in size. Optimization of process parameters in manufacturing is eminent due to reliability issues. This paper reports the parameters that affect the quality of the bump height in electroless nickel immersion gold (ENIG) and their relationships between each other. A total of four different combinations of parameters have been carried out for this investigation using the design of experiment (DOE) approach. It can be concluded that higher temperature of electroless nickel permits an increase of bump height where as the increment in immersion gold temperature does not nessasarily affect the value of bump height. All four samples recorded a higher value of bump height than the controlled bump height value. This implies reliability of the solder joint and assembly process robustness can be improved with an increase of bump height by increasing the time.
3D Micro-Radiography Imaging for Quick Assessment on Small Specimen
Authors: Wiguna Gede Arya , Suparta Gede Bayu , Louk Andreas Christian
Published: February 2014

An imaging procedure for developing a 3D X-ray micro-radiography system has been developed. The idea arose due to the necessity of performing internal inspection and testing nondestructively on a small specimen. The image is generated from multiple x-ray radiograph that were acquire from multiple angle of view. Each radiograph was taken for every one degree. The total angle covers up to 360 degree so that a set of 360 image were collected for each specimen. Then, for those images were rendered to be a 3-D image. A set of image processing procedures were applied such as background subtraction and noise reduction. From the experiment, this manner is very useful for assessing a small specimen nondestructively prior to perform a tomography inspection.
Synthesis of Low Fouling Porous Polymeric Membranes
Authors: Susanto Heru , Julyanti Dwi Putri , Roihatin Anis
Published: February 2014

The fouling problem has to be solved because fouling significantly reduces the performance of porous polymeric membranes. This paper presents methods to prepare low fouling membranes or to modify commercial/existing membranes to be low fouling membranes. At first, the principle of membrane separation as well as fouling phenomenon is presented. Important low fouling characters are also outlined. Thereafter, modification of membrane polymers to obtain low fouling character, principle as well as recent development in preparation of low fouling polymeric membranes and membrane modification of commercial/existing membrane are discussed.
Titania Coated Ceramic Membrane from Clay and Muntilan Sand for Wastewater Filter Application
Authors: Masturi Masturi , Sustini Euis , Khairurrijal Khairurrijal , Mikrajuddin Abdullah
Published: February 2014

A ceramic membrane was fabricated from clay and Muntilan sand using sol-gel method with certain amount of titania coated on the membrane surface. Polyethylene glycol (PEG) was used as a pore-agent. The main steps of the process are hot-pressing and calcination. Varying the clay:sand:PEG ratio membranes permeability was obtained between 6.39 x 10-13 m2/Pa.s and 1.39 x 10-11 m2/Pa.s. The addition of sand volume fraction improves the permeability produced as result of the larger of the sand particle producing the higher pores. The filtration performance was tested using aqueous solutions of methylene blue (MB) as one of the main pollutants produced from textile industries. Under a pressure difference of 4 kPa, the concentrations of MB remaining in the solution varied from 1.73% to 10.29% depending on the permeability. Therefore, the membrane is very potential to be applied as wastewater filter for coping with the availibity of clean water.
High Sensitivity Fluxgate Sensor for Detection of AC Magnetic Field: Equipment for Characterization of Magnetic Material in Subsurface
Authors: Indrasari Widyaningrum , Djamal Mitra , Srigutomo Wahyu , Hadziqoh Nur
Published: February 2014

A magnetic material characterization at subsurface of soil using portable controlled source electromagnetic (CSEM) methods needs a continuous signal which has frequency more than 1 kHz. This signal can be obtained from the function generator which its output was amplified by a power amplifier with a gain of 16 times. The AC output current of the power amplifier can be varied from 0.1 A 0.45 A at frequency of 5 kHz. To generate an AC magnetic field, the output of the power amplifier is then connected to the solenoid with a ferrite-core coils number of 130 and diameter of 3 cm. The AC magnetic field was detected by fluxgate sensor with high sensitivity (568 mV/μT or 1.76 nT/mV). By adjusting the excitation and phase detector frequency in the electronic circuits of fluxgate sensor, will enable this sensor work at higher frequency. The signal processing circuit of fluxgate sensor uses the 2nd-order of Butterworth filter with frequency scaling factor of 10.6 kHz. By this method fluxgate sensor can detect the AC magnetic field frequency up to 10 kHz. The output voltage of this sensor has a maximum measurement range of 0.23 2.95 V at frequency of 5 kHz. Meanwhile, the minimum detectable magnetic field is 1.5 μT; with a relative error of measurement was 2.74 %.
A New Type of Planar Chamber for High Frequency Ozone Generator System
Authors: Facta Mochammad , Salam Z. , Buntat Z.
Published: February 2014

This paper proposes a new type of planar chamber ozone generation operated at atmospheric pressure, ambient temperature and high frequency. The chamber was constructed in planar type with easy adjustment using simple filler material and arrangement for different type of electrodes. A prototype was developed based on study to find the most effective geometrical electrode shape and dielectric material to produce micro-discharges without additional discharge gas, low pressure and temperature.. The works were initially carried out by theoretical analysis and finite element simulations to find the best geometrical shape for the electrode and to prove theoretical prediction, the experimental works were set up to determine the preferable dielectric to be used along with the electrode. Finally, the best combination was revealed by using muscovite mica and aluminium mesh on copper plate to start generating ozone at 785 Volt and 30 kHz. This planar prototype chamber successfully delivered the highest ozone yield more than 3000 ppm and 120 g/kWh. Due to the simplicity and low cost design, this planar chamber can be suitably used for portable and home appliance.
Synthesis and Characterization of Nanostructured Tungsten Oxide by Hard Template Method
Authors: Hongo Teruhisa , Usami Yoshihiro , Yamazaki Atsushi
Published: February 2014

Nanostructured WO3 was synthesized by a hard template method using platelet-shaped mesoporous silica SBA-15. The nanostructured WO3 consisted of nanorod arrays comprised of mixed crystalline tetragonal and monoclinic phases with the diameter of 8.5 nm and the length of 170-300 nm. The specific surface area was 30 m2/g, which was about 6 times higher compared to that synthesized without the template.
Effect of Heating Time on Atrazine-Based MIP Materials Synthesized via the Cooling-Heating Method
Authors: Royani Idha , Widayani Widayani , Mikrajuddin Abdullah , Khairurrijal Khairurrijal
Published: February 2014

Molecular imprinting is a technique to produce a polymer called as molecularly imprinted polymer (MIP) that provides cavities to form a particular space generated by removing the template when the polymer has been formed. It will recognize a target that has the shape and physico-chemical properties similar or identical with those of template molecule. In this study, MIPs using atrazine as template have been made via the cooling-heating method. Initially the pre-polymer solution was cooled at a refrigerator for 1 h. Next, the polymerization was carried out at 70 °C for heating times of 90, 120, and 150 min. without nitrogen flow which is generally done for polymerization process. Characterizations were performed by employing a reversed-phase high performance liquid chromatograph (HPLC) and scanning electron microscope (SEM). From Scatchard plots, it was found that the equilibrium dissociation constant KD and the apparent maximum number of binding sites Bmax, which are written as (KD, Bmax), are (4.69 μM, 9.87 mmol/g), (4.54 μM, 9.56 mmol/g) and (3.52 μM, 7.44 mmol/g) for the heating times of 150, 120, and 90 min., respectively. This is verified by their SEM images showing that the broadest pore size distribution with the highest number of pores is in the MIP prepared under the heating time of 150 min. The MIPs therefore could be applied as an atrazine sensor and the MIP prepared under the heating time of 150 min. would give its best characteristics compared to the others.
Preparation of Orange Peel Based Activated Carbons as Cathodes in Lithium Ion Capacitors
Authors: Arie Arenst Andreas , Kristianto Hans , Suharto Ignatius , Halim Martin , Lee Joong Kee
Published: February 2014

In this work, activated carbon was prepared from Indonesian local orange peel using ZnCl2 activation method at various chemical ratios. The structural and morphological characteristics of orange peel based activated carbons were investigated using scanning electron microscope (SEM), Brunaeuer-Emmett-Teller surface analyzer. The highest surface area was estimated as 1200 m2g-1, obtained by the mass ratio of 1:2 (biomass : ZnCl2). The obtained carbon samples were then tested as cathodes in Lithium Ion Capacitors. Electrochemical measurement was examined by half cell configuration, using 1 M LiPF6 in EC/EMC/DMC solution (1:1:1 v/v) as electrolyte and Li metal as reference electrode. From cyclic voltammetry (CV) test, it was shown that orange peel based activated carbon demonstrated a stable electrochemical characteristics, with specific capacitance of 56 Fg-1 measured at scan rate of 1 mVs-1 under cut-off voltages between 2.5 and 4 V.
Bitumen Substance Analysis
Authors: Plachy Jan , Petranek Vít , Caha Zdenek
Published: February 2014

This contribution deals with the composition of the bitumen substance of bitumen waterproofing sheets used in bridge decks in the Slovak Republic. This contribution examines the samples of waterproofing sheets from various manufacturers in terms of the bitumen areal weight and the quantity of fillers in the bitumen substance. This contribution also answers the hypothesis of whether the quantity of bitumen is increased or decreased and the filler affects the basic thermal technical properties of bitumen waterproofing sheets, such as its flexibility at low temperatures and its heat resistance.
Development of Advanced Masonry Structures with Utilization of Alternative Thermal Insulating Materials
Authors: Zach Jiří , Hroudová Jitka , Sedlmajer Martin , Korjenic Azra
Published: February 2014

There has been increased effort for achieving enhanced properties of brickwork for external cladding of buildings, in particular as regards thermal insulation. This trend is caused by various factors, while the most important one is general aiming at reduction of energetic demand of buildings (within EU connected with the Regulation of the European Parliament and of the Council 2010/31/EU) and aiming at reduction of energetic demand of production of construction materials and building structures. The price of the products themselves is also important, because it determines their competitive strength in the market. One of the ways of development of thermal insulation brickwork with enhanced end-used properties with low price and minimal demands for material resources is use of secondary raw materials with low value of thermal conductivity. The paper describes possibilities of using granulated PUR material manufactured from water PUR foam used for production of thermal insulation form-pieces with integrated insulation layer.
Proposal and Testing Masonry Cement
Authors: Magrla Radek , Dvořák Karel , Kulísek Karel
Published: February 2014

This work deals with proposal and testing of cement mixtures normative called as Bricking cement. The norm demanded properties were tested on these cement mixtures depending on amount and type of used chemical admixtures. Technically it is possible to define this mixture binder as premix binder for ambulatory preparation of mortar and plaster admixtures.