bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanical Response Analysis of the Composite Asphalt Pavement
Authors: Li Li Min
Published: August 2014

With the constant increasing of traffic flow and axle load, the early failure of semi-rigid base asphalt pavement is increasingly serious in China. The bad durability and short service life of pavement have become main obstacles in road construction development. Based on the experience of successful application, the early failure of semi-rigid base asphalt pavement is solved, and the service life of pavement is increased by using of the composite asphalt pavement. To solve the design problem of the composite asphalt pavement , its mechanical properties influence results of are obtained by the factors, such as shear strain, shear stress, compression strain on top of subgrade, etc, by a lot of calculation using Shell pavement design software. These provide theoretical basis for durable asphalt pavement design based on rut-resistance property.
Synthesis of Symmetrical P1,P2-Dinucleoside Diphosphates with Pyrimidine Bases
Authors: Sun Jian , Gong Shan Shan , Sun Qi
Published: August 2014

Treatment of nucleoside phosphoropiperidates with 0.5 equiv of water in the presence of 4,5-dicyanoimidazole (DCI) provides an efficient method for one-pot synthesis of symmetrical P1,P2-dipyrimidine-nucleoside diphosphates under mild conditions.
Synthesis of Dinucleoside Triphosphates with Pyrimidine Bases
Authors: Wang Qiang , Gong Shan Shan , Sun Qi
Published: August 2014

A facile and efficient method for the synthesis of dinucleoside triphosphates with pyrimidine bases (Up3U, Cp3C, and Up3C) from the corresponding nucleoside 5′-phosphoropiperidates has been developed. The experimental results indicated that the employment of 4,5-dicyanoimidazole (DCI) as the activator could notably promote the coupling reaction.
Effect of Annealing Temperature of Hybrid CeO2/TiO2 Nanotubes on the Photocurrent
Authors: Azhar Mustaffa Ali , Rozana Monna , de Cunha Mabel , Anwar Dede Miftahul , Ahmadi Ehsan , Khairunisak Abdul Razak , Cheong Kuan Yew , Lockman Zainovia
Published: August 2014

Cerium oxide (CeO2) or known as ceria were deposited on titanium dioxide, TiO2, nanotubes by electrodeposition process as to produce hybrid materials that can generate photocurrent. The electrodeposition process is done by using 0.1 M cerium chloride mixed with 0.1 M ammonium acetate as ligands to promote stability complexes in a standard two electrode bath. Voltage and pH were controlled to ensure the most optimum condition of cerium oxide deposition. Samples were then annealed at different temperatures. Photocurrent results indicate that annealed sample at 450°C shows the best photocurrent due to high degree of anatase and cubic crystallinity.
Effects of Graphene Nanopletelets on Poly(Lactic Acid)/Poly(Ethylene Glycol) Polymer Nanocomposites
Authors: Chieng Buong Woei , Azowa Ibrahim Nor , Yunus Wan MD Zin Wan , Hussein Mohd Zobir
Published: August 2014

Graphene nanoplatelets (xGnP) were investigated as a novel nanoreinforcement filler in poly (lactic acid)(PLA)/poly (ethylene glycol)(PEG) blends by melt blending method. The prepared nanocomposites exhibited a significant improvement in tensile properties at a low xGnP loading. The tensile properties demonstrated the addition of 0.3wt% of xGnP led to an increase of up to 32.7%, 69.5% and 21.9% in tensile strength, tensile modulus and elongation at break of the nanocomposites respectively, compared to PLA/PEG blend. The nanocomposites also shows enhanced thermal stability compared with PLA/PEG blend in thermogravimetry analysis (TGA). Scanning electron microscopy (SEM) image of PLA/PEG/0.3wt% xGnP displays good uniformity and more homogenous morphology.
Preparation of Linear Low-Density Polyethylene-g-Poly(Acrylic Acid)-Co-Starch Hydrogel
Authors: Irani Maryam , Hanafi Ismail , Ahmad Zulkifli
Published: August 2014

In this work, a type of hydrogel from waste linear low density polyethylene (LLDPE), acrylic acid (AA), and starch was prepared using N, N-methylenebisacrylamide (MBA) as the crosslinker, and benzoyl peroxide as the initiator. The hydrogel was characterized by Fourier transform infrared spectroscope (FTIR), scanning electron micrograph (SEM), and X-ray diffraction (XRD). The results confirmed the incorporation of acrylic acid and starch in the LLDPE chain. SEM results show that the prepared hydrogel has a porous structure. Product showed maximum water absorbency of 180 g/g in distilled water.
A Spectroscopic Study on the Polymer Colour Transition for Indicating the Exposure to Ionizing Radiation
Authors: Naurah Mat Isa , Liyana Mohd Ali Napia , Hamzah Mohd. Yusof
Published: August 2014

This paper presents results from a series of experiments in which two combinations of polymer-dye film were exposed to ionizing radiation (electron beam). These experiments were performed for the purpose of investigating the possibility of polyethylene (PE) and polyvinyl chloride (PVC) with and without the addition of malachite green (MG) dye for radiation indication in the form of colour transition. MG dye was also inspected whether it has experienced the photodarkening from the exposure to ionizing radiation. The experiments were carried out using samples in the form of film. From this study, it was proven that the polymers and dye do not work alone to give the change. Halogen-containing polymer was found positive in stimulating the acid-sensitive dye for the transition of colour. The colour transition of the combination of PVC/MG without pH adjustment was consistently increasing with irradiation level. The transition is observed even at 100 kGy of the radiation exposure. Samples with the addition of basic solution have a rapid change in terms of colour but the limit of sensitivity was decreased to only 20 kGy of radiation exposure.
Effect of Lamination Layers on Tensile Properties and Mould Cleaning Efficiency of Laminated NBR Latex Composite
Authors: Rashid Azura A. , Md Sidek Mufidah , Chean Tan Svin
Published: August 2014

Mould cleaning process is the process of removal build-up deposited or residue material on the mould surface after repeated cycles of production. The currently used mould cleaning process is sand blasting (abrasive process) and dry rubber mould cleaning compounds (depends on the skill of the operators during rubber compounding). Latex laminated compounds will be beneficial as a new substitute for mould cleaning because of its excellent strength properties and the lamination process to increase its thickness. The main focus of this research is to investigate the effect of lamination process on mechanical properties and mould cleaning efficiency of laminated Nitrile Butadiene Rubber (NBR) latex composites. Laminated NBR latex films with cleaning agent and waste latex compound was prepared by arranging half-cured latex sheets with various thicknesses of outer layer (NBR latex films with cleaning agent) and core layer (waste NBR latex film). The core and outer layers are prepared through casting method with different thickness. The laminated films were subjected to compression moulding using hot press at 120°C. Reinforcement of the core layer gives laminated latex composite with better mechanical properties, but excessive of core layer portion reduced the mechanical properties of laminated films. The efficiency of mould cleaning of laminated NBR latex films were depends on the flow ability and adhesion properties of the fresh latex layer with mould cleaning agent (outer layer).
Controlled Growth of ZnO Nanoparticles with Different Morphologies Using Sol-Gel Technique
Authors: Thein Myo Thuya , Pung Swee Yong , Aziz Azizan , Itoh Mitsuru
Published: August 2014

A low temperature sol-gel approach was demonstrated to prepare ZnO nanoparticles with controlled morphologies. By changing the concentration of NH4OH, the ZnO nanoparticles evolves from sphere-like, star-like and sheet-like structures. No peak of additional phase was observed in the XRD patterns except the diffraction peaks of ZnO. The estimated crystallite size of ZnO nanoparticles decreases with the increase of NH4OH. It is also found that the morphology of nanoparticles affects the optical bandgap of ZnO. The optical bandgap of sphere-like,star-like, and sheet-like ZnO nanoparticles are 3.55 eV, 3.48 eV and 3.45 eV, respectively. The growth mechanism of ZnO nanoparticles was discussed.
The Production of Green Polymer - Hyperbranched Curable Palm Oil Oleic Acid
Authors: Salleh Mek Zah , Badri Khairiah , Tajau Rida , Salleh Nik Ghazali
Published: August 2014

Palm oil is one of the main raw materials available in the country. Hence, the diversification ofpalm oil derivatives into new products has been given priority. The development of new radiation curable materials for applications in radiation ultraviolet (UV) or electron beam (EB) curing technology is an important research area. The hyperbranched curable polyurethane acrylate (HBPUA) from oleic acid of palm oil has been synthesized through a three-step reaction. Dipentaerythritol was initially reacted with 2, 2-bis (hydroxymethyl) propionic acid in a solution medium aided by p-toluene sulfonic acid as a catalyst to form hyperbranched polyol polyester first generation (HBP-1). HBP-1 then used as the core and reacted with palm oil oleic acid to form the hyperbranched polyol polyester second generation (HBP-2). HBPUA was prepared by reacting HBP-2 resin with diisocyanate and hydroxyl-containing acrylate monomer with the presence of 0.1-2 wt% dibutyltin dilaurate as a catalyst. The reaction was confirmed by several analytical data namely hydroxyl value (OHV), fourier transform infrared (FTIR), gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR) analyses. The HBPUA was easily curable when subjected to EB radiation. The thermal decomposition of HBPUA showed good thermal stability up to 450 oC.
Effects of Binders System on Sintered Properties of Metal Injection Molding Parts of M2 High Speed Steel
Authors: Sauti Rosliza , Wahab Nor‘aini , Omar Mohd Afian , Ahmad I.N.
Published: August 2014

This paper reports on the compatibility of waste rubber binder combined with conventional binder, paraffin wax and local binder, palm stearin for M2 High Speed Steel injection molding in order to obtain the better properties. The feedstock was prepared at a powder loading of 65 vol.% using 22um M2 High Speed Steel powder and the binders consisting of 55wt.% paraffin wax/palm stearin, 21wt.% polyethylene, 14wt.% waste rubber and 10wt.% stearic acid. The specimens were then sintered in vacuum atmosphere within a temperature range from 1200°C to 1260°C. The results shown even the best properties is obtain from the conventional binders, paraffin wax, thus the properties of local binders palm stearin is still comparable and good. The maximum density of paraffin wax binder was 8.095g/cm3 achieved at temperature 1250°C and palm stearin binder was 8.111g/cm3 achieved at temperature 1240°C. Therefore, in term the best strength of paraffin wax was 2351Mpa whilst palm stearin was 2210MPa, both recorded at temperature 1230°C.
Tungsten Inert Gas Surface Alloying of Commercial Purity Titanium (CP-Ti) with Fe-C-Si Ternary Mixtures
Authors: Adeleke S.A. , Maleque M.A.
Published: August 2014

Surface modification by means of alloying is a vital process to improve the performance of a material surface which is subjected to wear and corrosion environments without altering the bulk properties. In this study, the surface of commercial purity-titanium (CP-Ti) material was alloyed using pre-placed powder mixture of iron, silicon and carbon at different weight ratios under TIG torch melting technique. The effects of energy input (1080 and 1350 J/mm) in TIG torch on the melt geometry, topography, microstructure and hardness were examined. The results showed that the TIG torch produced melt pools geometry with hemispherical in shape and different geometrical dimensions. Pores were seen to be concentrated at the edges where low melting energies are prominent to entrapped escaped gases upon fast melt solidification. The melt layers with the 1350 J/mm consisted of armed typed of TiC precipitation in the presence of longer solidification time. The sizes of dendrites observed at energy inputs of 1350 J/mm was found to be greater in population and larger in the middle of the melt pool compared to the energy input of 1080 J/mm. The alloyed layer exhibited a maximum hardness of ~ 810 HV which is about 4 times greater than the base hardness of 200 HV. The high hardness observed at particular areas is attributed to the higher population and larger sizes of dendritic microstructure produced using 1350 J/mm TIG arc source compared to 1080 J/mm which was dominated by lesser precipitated TiC resulting lower hardness values in the melt pool. Keywords: Surface modification; TiC; TIG; dendrites; microhardness
Characterization of Ceramic Tiles Added with EAF Slag Waste
Authors: Teo Pao Ter , Anasyida Abu Seman , Nurulakmal Mohd Sharif
Published: August 2014

The increasing production of steel leads to an increment of solid wastes generated especially Electric Arc Furnace (EAF) slag. This becomes a serious concern as the slag has to be disposed in a proper manner in order to avoid dumping in landfills which will eventually occupy available land and may cause permanent damage to the flora and fauna. In this project, an attempt was made to utilize the EAF slag as one of the raw materials in ceramic tiles. Results obtained showed that as percentage of EAF slag added was increased up to 60%, percentage of apparent porosity and water absorption were found to increase, accompanied by reduction in flexural strength due to more severe porosity was observed in the tiles. On the other hand, reducing the percentage of EAF slag up to 40% while increasing percentage of ball clay added led to formation of higher total percentage of anortite and wollastonite minerals. This would contribute to higher flexural strength of tiles. In addition, by adding silica and feldspar, the flexural strength of tile produced was further improved due to optimization of densification process. Highest flexural strength of EAF slag based tiles was attained at composition of 40% EAF slag 30% ball clay 10% feldspar 20% silica. It was observed that properties of ceramic tiles added with EAF slag, especially flexural strength are comparable with commercial ceramic tiles. Therefore, the EAF slag ceramic tiles have great potential to be made into high flexural strength or wear resistant floor tiles.
Effect of Feldspar Content on Electric Arc Furnace Slag (EAFS) Added Tiles
Authors: Hasmaliza Mohamad , Abu Seman Anasyida , Gan Wei Long
Published: August 2014

Electric arc furnace slag (EAFS) is a solid waste from steel making industrial. Previously, EAFS was deposited, recycled or used as fertilizer. In present study, EAFS is used as one of the raw materials in ceramic tile production. EAFS added tiles samples have been prepared by mixing of EAFS with ball clay, quartz and feldspar. The feldspar content was varied at various weight percentages (0, 10 and 20 %) to observe their effect on the produced samples. The raw materials mixture was pressed and then sintered at temperature range 1100°C-1175°C for 1 hour. In general, results shows that, sample with higher content of feldspar require shorter vitrification range and having relatively higher density and good strength properties. In addition, MOR value was increasing as the sintering temperature was increasing. However when the temperature reached 1175°C, the MOR was dropped which may be due to the early vitrification of the compositions, resulting in over firing, grain growth and recrystallization. Whereas the density values are relatively higher than the conventional vitreous ceramic tiles due to the presence of high amount of iron oxide from the EAFS.
Preparation of Globular Microstructure Aluminum Alloy Using Cooling Slope Casting as Feed Material for Equal Channel Pressing Process
Authors: Thuong Nguyen Van , Hussain Zuhailawati , Abu Seman Anasyida , Huy T.D.
Published: August 2014

Equal channel angular pressing (ECAP) could be used to achieve ultra fine grains in bulk aluminum alloy through severe plastic deformation. Typically a feed material of as-cast aluminum alloys is used with a typical hypoeutectic solidification structure, consisting of primary aluminum dendrites and interdendritic network of lamellar eutectic silicon. On the other hand, semi-solid metal casting provides non-dendritic and globular microstructure which is one of a considerable factor in obtaining homogenous microstructure after ECAP. This work is an attempt to produce aluminum alloy with globular microstructure using cooling slope semi-solid casting process which is believed suitable as a feedstock for ECAP. The aim of this work described in this paper was to understand of microstructural evolution of aluminum structure during cooling slope casting process. Two experiments were carried out. A sample was casted via a cooling slope into a vertical cold mild steel mould at pouring temperature of 640°C. Cooling slope length of 250 mm, slope temperature of room temperature and tilt angle of 60o was applied. Another sample was casted directly into a vertical cold mild steel mould at pouring temperature of 640°C. The primary α-Al phases in the sample that casted without cooling slope was mostly in dendritic throughout the section of sample whilst the primary α-Al phases transformed completely into non-dendritic in the sample that was casted via the cooling slope. Therefore, the transformation is believed resulted from the effect of cooling slope
The Design of Elastin-Like Polypeptides (ELPs) as a Nanoparticulate-Based Therapeutic and Diagnostic Imaging Agent
Authors: Mohd Janib Siti Najila , Minea Radu O. , Swenson Steve D. , Liu ShuangLong , Pastuszka Martha K. , Markland Frank S. , Conti Peter S. , Li ZiBo , Mackay J. Andrew
Published: August 2014

The goal of our study is to develop genetically engineered polypeptides that self-assemble into nanoparticulates, which can present functional moieties on their exterior and sequester drugs and/or imaging agents within their interior. These particulates are intended to improve the detection and treatment of malignancy.
Effect of Ageing Temperature on the Microstructures and Mechanical Properties of Ti-Nb Shape Memory Alloys
Authors: Hamzah Esah , Hastuti Kurnia , Hashim Jasmi
Published: August 2014

In this study, Ti-30at.%Nb was subjected to solution annealing at 900°C followed by ageing at 300o, 400°C, 500°C and 600°C for one hour in order to investigate the effect of ageing temperature on the microstructures and mechanical properties behaviour. It was found that the microstructures of the sample in solution anneal consists of β austenite phase. This indicates that the transformation temperature, Ms, of the material is below room temperatures. The presence of other phases such as α phase and ω precipitates has been detected on the samples after ageing at 500°C and 600°C. Maximum hardness value and tensile strength obtained on the sample aged at 500°C was associated with the presence of ω phase, however the existence of α phase in the sample aged at 600°C provides the lowest hardness and tensile strength. The solution treated sample shows the best shape memory behaviour compared to other heat treated alloys. However, the best superelastic behaviour was observed on the sample aged at 300°C.
Polyethylene Glycol Diacrylate Microgels from Irradiated Micelles
Authors: Yusof Hamzah , Naurah Mat Isa , Liyana Mohd Ali Napia
Published: August 2014

Micro sized gels have been widely used as drug carriers for its compatibility in blood. Among its important properties are round small dimensions and large surface area. These properties allow for better attachment of ligand and higher stability in the blood stream. In this study,microgels from polyethylene glycol diacrylate (PEGDA) were prepared from its microemulsions form using electron beam with energy of 3 MeVat different irradiation dose of 0 to 25 kGy. Dynamic light scattering (DLS) study revealed that gel with diameter of 70-100 nm with a narrow size distribution was obtained at 5 kGy and 400-550 nm with a broad size distribution at 25 kGy. The molecular weight obtained from GPC-MALLS for the minimum practical dose irradiated has resulted to more than 4.22 x 105 g/mol as compared to7.75 x 102 g/mol forunirradiated polymer. The increase of size and its distribution as well as its molecular weight over the elevation dose were suspected to be due to diffusion of micelles that leads to recombination of macro radicals from different micelles during longer irradiation period at higher doses. Overall findings from this study have proven that PEGDA microgels can be prepared via electron beam radiation with emulsions as templates for polymerization.
The Structure and Electrochemical Performance of LiNi0.3Co0.3Mn0.3Cr0.1O2 Cathode Materials
Authors: Roshidah Rusdi , Kamarulzaman Norlida , Mohd Hilmi Jaafar , Azilah Abd Rahman , Nor Sabirin Mohamed , Fun Hoong Kun
Published: August 2014

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Layered cathode materials are important for Li-ion battery application due to their high theoretical specific capacity. Efforts have been made to synthesize mixed-metal cathode materials such as LiNi1/3Co1/3Mn1/3O2 based materials with promising electrochemical characteristics. This is to lower the expensive Co content and help to stabilize the materials. Substitution of these materials with chromium producing LiNi0.3Co0.3Mn0.3Cr0.1O2 material will also improve the stability of the cathodes. In this work, pure and single phase LiNi0.3Co0.3Mn0.3Cr0.1O2 material was successfully synthesized using a combustion method. The samples were then annealed at 900 °C for 24, 48 and 72 h. From the charge-discharged measurements, it was found that the performance of the LiNi0.3Co0.3Mn0.3Cr0.1O2 cathode material annealed at 900 °C for 24 h shows the best performance.

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Fe-TiO2 Nanoparticles by Hydrothermal Treatment with Photocatalytic Activity Enhancement
Authors: Aida Ibrahim Siti , Sreekantan Srimala
Published: August 2014

Fe-TiO2 nanoparticles with 5-9 nm sizes were prepared by sol gel method subsequently subjected to hydrothermal treatment at 150°C for 6 h. Titanium (IV) isopropoxide and iron (III) nitrate nonahydrate were used as precursor. The morphology, structure and composition of the Fe-TiO2 were investigated by X-ray diffraction (XRD), Transmission emission microscopy (TEM) and UV-vis spectroscopy (UV-vis). XRD analysis revealed the prepared samples was dominated with anatase phase and a trace of brookite phase. The TiO2 crystallite size was reduced as Fe content was increased. Compared with the pure TiO2 nanoparticles, the Fe-TiO2 nanoparticles exhibited higher photocatalytic activity in decolorizing methyl orange into non-toxic inorganic products under UV irradiation.
Structural and Leaching Properties Study of Ce and Pr Lead Silicate Glasses
Authors: Alias Nor Hayati , Isa Norriza Mohd , Isa Muhammad Jamal Md , Ahmad Megat Harun Al Rashid Megat , Matori Mohd Khalid
Published: August 2014

In this study, Cerium (Ce) and Praseodymium (Pr) containing lead silicate glasses were produced with 2 different weight percentage (low 0.2 wt% and high 0.4 wt% content). The presence of Ce and Pr in the glass mixture might be expected to alter the structural and leaching glass properties. The radiation shielding properties of the synthesized glasses is explained in the form of lead equivalent study. The FTIR (Fourier Transform Infrared Spectrometer) was performed as to observe the structural changes of the synthesis glasses at 1.5 Gy gamma radiation exposures. Leaching study is performed by ICP (Inductively coupled plasma spectrometry) analysis.
Simulation and Fabrication of Silicon Field Emission Cathodes for Cold Electron Sources
Authors: Langer Christoph , Prommesberger Christian , Lawrowski Robert , Dams Florian , Schreiner Rupert
Published: August 2014

We report on the simulation and fabrication of nanostructured silicon surfaces for field emission (FE) applications, e.g. ionization sensors and x-ray tubes. For the design and optimization of field-emitting silicon structures, the influence of the geometric parameters like tip height, apex radius, aperture angle and curvature shape on the field enhancement factor was investigated by simulation using finite element method. A universal geometric model which describes the real geometry of our silicon structures sufficiently accurate was taken for modeling a variety of different silicon tip structures as well as ridge structures. While a high dependency of the field enhancement on the aspect ratio and the aperture angle was found, the simulations show that the elliptic curvature affects the field enhancement only marginally. Finally, an improved process for fabrication of such silicon structures on n-type as well as p-type substrate is described, using reactive ion etching with adjustable anisotropy, wet thermal oxidation and wet etching.
Synthesizing Vertically Aligned Zinc Oxide Nanowires on Borosilicate Glass Using Vapor Trapping Approach
Authors: Shamsudin Nurul Hanim , Abdul Khalid Kamarul Aizat , Mohamed Khairudin
Published: August 2014

We demonstrate the vertically well-aligned zinc oxide (ZnO) nanowires synthesized on amorphous borosilicate glass (BSG) via simple chemical vapor deposition (CVD) process with a vapor trapping approach. During the process, zinc precursor was put inside a glass vial with the vial’s opening was directed towards the BSG substrate, which is being placed downstream from the gas flow and approximately 30-40 mm from the precursor. The BSG substrates were coated with Nichrome (NiCr) and gold (Au) coating prior to the synthesis process. Vertically aligned nanowires with a high aspect ratio was found to be deposited in total operating pressure of 20-25 bar with an Oxygen flow rate range of 5-10 sccm and argon flow rate range of 30-50 sccm. This vapor trapping approach using BSG substrates provided a good alternative towards controllable growth of ZnO NWs on any much cheaper amorphous substrates for future development of low cost energy-converter heat cell devices based on ZnO nanowires.
Preparation of WO3 Nanorods by Seeded Growth Hydrothermal Reaction
Authors: Ng Chai Yan , Yip Zhang Rong , Khairunisak Abdul Razak , Lockman Zainovia
Published: August 2014

Tungsten oxide (WO3) nanorods were successfully grown at low temperature of 90 °C by seeded growth hydrothermal reaction. The effect of sodium chloride (NaCl) addition on nanorod aggregation was studied. The hydrothermal reaction was conducted at various reaction periods (16-24 h). Monoclinic WO3 nanorods started to grow from the seeds after 18 h of hydrothermal reaction and more vertical nanarods were formed after 20 h of treatment. The addition of NaCl successfully reduced the aggregation of nanorods. Cyclic voltammetry (CV) was performed to measure the electrochromic properties of the WO3 nanorods. WO3 nanorods grown with NaCl showed faster intercalation and de-intercalation processes due to less nanorods aggregation.
Formation and Characterization of TiO2 Scattering Layer Deposited by Spray Pyrolysis for DSSC
Authors: Yaacob Khatijah Aisha , Borhanuddin Mohamad Syahir
Published: August 2014

In this paper the TiO2 nanoparticle for scattering layers were prepared using hydrolytic and non-hydrolytic sol gel route. The TiO2 nanoparticles by hydrolytic sol gel were prepare by adding 5 ml of titanium (IV) isopropanol (TTIP) with 15 ml isopropanol. Then this TTIP mixture was added dropwise into 250 ml water with adjusted pH to 3 using nitric acids. For non-hydrolytic sol gel route 12 gram of acetylacetone, 12 gram of TTIP and 16 gram of ethanol anhydrous were mixed in a beaker under vigorous stirring. Then the prepared TiO2 nanoparticles solutions were deposited onto TiO2 mesoporous layer via spray pyrolysis and assemble into complete solar cell. From the XRD (X-ray diffraction) results show that the phase of TiO2 nanoparticles formed by hydrolytic sol gel route was amorphous and for non-hydrolytic route the phase formed was mixture of anatase and rutile. The efficiency of the solar cell shows that scattering layer prepare by hydrolytic route give higher efficiency, 6.0 x 10-5 %, as compare to scattering layer prepare by non-hydrolytic route, 4.9 x 10-5 %.
Research on Preparation and Stacking Performance of IPMC
Authors: Xu Yan , Gang Zhao , Ma Chang Shun , Sun Zhuang Zhi
Published: August 2014

In order to improve the performance of IPMC, a chemical deposition method was utilized to manufacture IPMC with silver electrodes (Ag-IPMC), and methods of ion exchange and ionic liquid penetration were adopted to conduct modified treatment for original IPMC. Additionally, the stacking performance of IPMC, which was disposed by ionic liquid penetration after the modified treatment, was analyzed. Results showed that: Ag-IPMC, which was modified by treating in 2mol/L LiCl solution for three hours, presented the optimal performance. Also, the IPMC after modified treatment by ionic liquid penetration swung longer in air, and its tip output displacement was stable at five millimeter; without any change with time. Furthermore, the stacked model of IPMC decreased the excursion of center in the process of swinging, and it also increased the output force of IPMC. The stacked model, which was composed with 3 sheets of IPMC after modifying treatment by ionic liquid penetration, was verified to have the optimal performance.
Analysis of Operational Modal Identification Techniques Performances and their Applicability for Damage Detection
Authors: Rizzo Andrea Antonio , Giannoccaro Nicola Ivan , Messina Arcangelo
Published: August 2014

Operational modal identification techniques, also known asAmbientmodal orOutput Onlymodal, have been in recent years object of growing interest within several applications typical of civil, mechanical and aerospace engineering. In this paper, two of them, known as EFDD and SSI, are fully implemented by means of in-house codes and applied on a finite element beam model dynamic response time data, in order to evaluate their accuracy, focusing on the lowest system’s natural frequencies. Assessments of the techniques’ robustness to a disturbance in the random excitation, reliability when implementing on a small number of measurement channels and in localization and quantification of a given damage in multiple sites are also performed and presented.
Non-Destructive Techniques and Monitoring for the Evolutive Damage Detection of an Ancient Masonry Structure
Authors: Foti Dora
Published: August 2014

In the present article non-destructive testing evaluation of the existing damage evolution has been applied to some buildings of the medieval town of Craco (Matera, Italy) and, in particular, to the Normand tower. Actually the little town of Craco is totally abandoned as a consequence of the activation of the landslide motions of its soil depth. Nevertheless, the Normand tower still stands because it is located on a stable and stiffer foundation ground. The tower was built in the XII century. It is 20 m tall and has a symmetric square plan, with dimensions 11 m x 11 m; it was built for defense against enemy attacks. Inside the tower a cistern in reinforced concrete was placed in 1949. It is not connected to the structural walls of the tower; however it represents an obstacle for installing the damage detection equipment and sensors. In this article a preliminary study on the masonry structure of the Normand tower is carried on. A finite element numerical model has been developed and a modal analysis has been performed. The final aim of the research is to find out the evolutionary stage of the cracks and to propose a possible retrofit of the tower.
The Old City of Jerusalem between Heritage and Urban Renewal: Public Buildings and Typological Aspects
Authors: Rociola Giuseppe Francesco
Published: August 2014

The interest in the study of public buildings in ancient nucleus of Jerusalem stems from the need to investigate the develop principles of the urban structure between the Tyropoeion Valley and the western edge and northern of the Haram al-Sharif. The building fabric including madrasas, Ribat, hammams and the Suq al-Qattanin is only the latest result of a layering process culminating with the transformation work produced by Mamluks from 1260 until 1517. The identification of a modular distance between the routes or the measure correspondence in the individual blocks, suggest the adaptation of a previous planned urban fabric, dating probably at least to the Herodian period. The increase of religious pilgrimages and trades in Jerusalem during the Mamluk sultanate has stimulated an intensive building activity, centered mainly in the construction of Madrasas and Ribat, organically aggregated to form an urban fabric heavily infilled. In a period running from mid-XIII at the end of the fifteenth century, the building fabric finds its final set, then completed by Ottomans between the sixteenth and seventeenth century and involving especially, in addition to the reconstruction of the walls, the building of small libraries, the upgrading of existing buildings and construction of fountains in nodal points of urban structure. The paper explains a research in progress about historical urban fabrics of Jerusalem, [1] in which the close relation between the urban structure and the buildings is one of the main aspects toward an urban renewal hypothesis of the Old City, that is characterized by complex relationship among international heritage programs, public safety, and contemporary uses coherent with the role of the ancient public buildings according to the urban history.
Preventive Fire Risk Assessment of Italian Architectural Heritage: An Index Based Approach
Authors: Arborea Alessandro , Mossa Giorgio , Cucurachi Giorgio
Published: August 2014

One of the most challenging problems of the ancient architectural heritage is its protection from fire risk. The “Italian Risk assessment map of the cultural heritage” (Carta del Rischio [1]), is a GIS-based platform developed by the Italian Central Institute for Restoration (ISCR) to assess the exposure and the vulnerability to static-structural, environmental, anthropogenic and seismic risk of the historical and cultural heritage. The paper marks a new phase of development of the Risk Map Information System aiming at integrating the vulnerability estimation of the historical buildings with a new method derived from the Fire Risk Index Method for Multi-storey Apartment Buildings (FRIM-MAB). The new index-based method has been tested in a full scale case-study in comparison with both the Italian prescriptive assessment and the performance-based fire protection approach. Results show the capability of the approach, its reliability and user friendliness.
The Norman Tower in the Abandoned Village of Craco (MT). Meaning and Reasons of the Restoration
Authors: de Cadilhac Rossella
Published: August 2014

The study of the Norman tower in the abandoned village of Craco (MT) is part of a larger research aimed at the development of a project for conservation and enhancement of the entire urban organism which, complying with the nature of the area, can not take into account the geological critical condition and the consistent safety problem.
Large-Scale Seismic Vulnerability Assessment Method for Urban Centres. An Application to the City of Florence
Authors: Ripepe Maurizio , Lacanna Giorgio , Deguy Pauline , de Stefano Mario , Mariani Valentina , Tanganelli Marco
Published: August 2014

The seismic vulnerability assessment of a building requires a comprehensive knowledge of both building structural features and soils geophysical parameters. To achieve a vulnerability assessment at the urban scale a large amount of data would be necessary, with a consequent involvement of time and economical resources. The aim of this paper is hence to propose a simplified procedure to evaluate the seismic vulnerability of urban centres and possible seismic damage scenarios in order to identify critical areas and/or building typologies to plan future actions of seismic risk mitigation and prevention. The procedure is applied to the outstanding case study of the city of Florence. The research is based on the definition of major building typologies related to construction periods and type of the structural system (masonry or reinforced concrete), the identification of a set of sample buildings, the analysis of the dynamic behaviour and the evaluation of a vulnerability index with an expeditious approach. The obtained results allow to define potential vulnerability and post-event damage scenarios related to the expected levels of peak ground acceleration.
Buildings Behavior in the Urban Fabric: The Knowledge Issue in the Post-Earthquake Reconstruction Plans
Authors: Carocci Caterina F. , Circo Chiara
Published: August 2014

This paper - the first of two companion papers [1] - focuses on some considerations about the issue of the knowledge of masonry buildings in aggregate, which aims at evaluating the safety and, at the same time, the preservation inquiry of this built heritage.
Investigation on the Degree of Reaction and Strength Performance of Fly Ash Based Geopolymer Binder with Alternative Chemical Reagents
Authors: Rahman Norbaizurah , Kusbiantoro Andri
Published: August 2014

The existence of high calcium contents in fly ash will contribute to the rapid stiffening and low workability of geopolymer paste. This study reports the feasibility of sodium nitrate and citric acid as the alternative admixtures for geopolymer binder. The effects of sodium nitrate and citric acid were independently evaluated at 0.5%, 1.5% and 2.5% of fly ash weight in geopolymer mixture. The effect of these admixtures on fresh geopolymer characteristic was evaluated through series of setting time and flow table workability tests, while degree of hydration, compressive strength and porosity tests were conducted to provide fundamental information on the hardened properties of geopolymer paste. Based on the result of degree of reaction, the inclusion of sodium nitrate in fly ash based geopolymer will increase the level of degree of hydration. Nevertheless, this result is in contrast with citric acid inclusion where degree of hydration decreased along with the increasing dosage of citric acid in the mixture. Strength development of geopolymer paste, particularly during the early age, appears to be affected by various geopolymerization rate presented by these admixtures.
Characterization of Soils as Potential Raw Materials for Soil Stabilization Application Using Geopolymerization Method
Authors: Zaliha S.Z. Sharifah , Al Bakri Abdullah Mohd Mustafa , Kamarudin Hussin , Fauziah A.
Published: August 2014

Soft soil has been associated to many problems especially in engineering field. Continues research and studies are done to find other alternatives in soil stabilization that environmental friendly and economic. Geopolymerization is one of the developing fields that can fulfill those requirements. In this preliminary study, three samples of soil (Soil 1, 2 and 3) were examined to investigate their potential for geopolymerization method based on their characterization. X-ray fluorescence, X-ray diffraction and scanning electron microscope were conducted. From the results, the soils do have potential, however, further investigations need to be done after this study to evaluate whether the soils are suitable using geopolymerization method for soil stabilization.
Effect of NaOH Concentration on Microstructure of Boiler Ash Based Geopolymer
Authors: Yahya Zarina , Al Bakri Abdullah Mohd Mustafa , Kamarudin Hussin , Khairul Nizar I. , Razak A.R.
Published: August 2014

Boiler ash is one of the waste material from palm oil processing industry and it was widely available. The role of alkaline activator in geopolymer is important for its mechanical properties. NaOH and sodium silicate solution was used as alkaline activator. In order to investigate effect of NaOH concentration on microstructure of boiler ash based geopolymer 6 different NaOH concentration (6M, 8M, 10M, 12M, 14M, 16M) were used. The boiler ash based geopolymer samples were cured in oven at temperature 80 °C for 24 hr. The compressive strength of geopolymer samples at 7 days showed that 14M obtained the maximum strength (13.9 MPa). This result was supported with SEM analysis were the 14M geopolymer sample showed more dense geopolymer matrix compared to others.
Comparison of Using NaOH and KOH Activated Fly Ash-Based Geopolymer on the Mechanical Properties
Authors: Abdul Rahim R.H. , Rahmiati Tia , Azizli Khairun Azizi , Man Zakaria , Nuruddin Mohd Fadhil , Ismail Lukman
Published: August 2014

Geopolymer synthesis has two main requirements to fulfil which are the source material that is rich in Silicon (Si) and Aluminum (Al) and alkali activator such as sodium/potassium hydroxide. Sodium hydroxide (NaOH) is widely used for the synthesis of geopolymer compared to potassium hydroxide (KOH) with addition of silicate solution for the purpose of increasing dissolution process. However, the comparison of using different activator in the absence of silicate solution for geopolymer synthesis is not well established. This paper presents an evaluation on compressive strength of fly ash–based geopolymer by using different activator (KOH and NaOH) with respect to different curing conditions (time and temperature) in the absence of sodium silicate. The samples were mixed using mortar mixer and prepared in 50mm x 50mm x 50mm mould for determination of compressive strength. It can be observed that the highest compressive strength up 65.28 MPa was obtained using NaOH. Meanwhile, synthesis using KOH only recorded 28.73 MPa. The compressive strength was better when cured at elevated temperature (60°C) than room temperature (25°C). Further analysis on the microstructure of the highest compressive strength geopolymer samples for both activators was carried out using Field Emission Scanning Microscopy (FESEM) and Raman spectroscopy.
The Effect of Silicon Nitride Addition on Microstructure and Microhardness of SN100C Solder Alloy Using Powder Metallurgy
Authors: Ramli Mohd Izrul Izwan , Saud Norainiza , Mohd Salleh Mohd Arif Anuar , Nazree Derman Mohd , Mohd Said Rita , Nasir Norhayanti
Published: August 2014

The effect of Si3N4particulate addition on the commercial SN100C solder alloy has been investigated. The SN100C/Si3N4composite solder was fabricated via powder metallurgy (PM) technique. In this study five different Si3N4composition which have been chosen were (0 wt. %, 0.25 wt. %, 0.5 wt. %, 0.75 wt. %, and 1.0 wt. %).The results showed that Si3N4particulate has remain as foreign particles and precipitate at the grain boundaries thus improved the physical properties of the composite solder compared to monolithic solder alloy. The addition of 1.0 wt. % Si3N4give highest hardness value to the composite solder.
Effect of Polypropylene-Methyl Polyhedral Oligomeric Silsesquioxane Compatibilizer in Polypropylene/Silica Nanocomposites: Mechanical, Morphological and Thermal Studies
Authors: Sofiah M.K. Anis , Ong Hui Lin , Akil Hazizan Md , Ishak Zainal Arifin Mohd
Published: August 2014

The Effect of 1 wt% and 3 wt% of polypropylene-methyl polyhedral oligomeric silsesquioxane (PP-POSS) as compatibilizer on polypropylene/silica (PP/SiO2) nanocomposites, prepared in the thermo Haake internal mixer was studied. The 3 wt% of PP-Methyl POSS added into PP/SiO2 system showed highest value of tensile strength. Moreover, nanocomposites with 3 wt% of PP-POSS compatibilizer showed the highest thermal stability among the nanocomposite systems in this study.
Effect of TiO2 Reinforcement on Microstructure and Microhardness of Low-Silver SAC107 Lead-Free Solder Composite Solder
Authors: Nasir Norhayanti Mohd , Saud Norainiza , Nazree Derman Mohd , Salleh Arif Anuar Mohd , Ramli Mohd Izrul Izwan , Said Rita Mohd
Published: August 2014

This research has investigated the physical performances of low-silver Sn-Ag-Cu (SAC) lead-free composite solder reinforced with titanium dioxide (TiO2). The SAC/TiO2 composite solder were fabricated via powder metallurgy (PM) technique. The five different composition chosen were 0, 0.25, 0.5, 0.75, and 1.0. The results showed that distribution of TiO2 along the grain boundaries has increased the hardness of the SAC/TiO2 composite solders compared to monolithic SAC solder alloy.
Testing on Building Material Using Waste Material in Fired Clay Brick
Authors: Kadir A.A. , Sarani Noor Amira , Leman A.M.
Published: August 2014

Clay brick is one of the building materials that have been used in the construction field for thousand years. It has been used as a major construction material because it can tolerate with severe weathering action, flexible properties and it is easy to handle. Many researchers have been incorporated waste material such as organic waste, waste treatment sludge, fly ash, cigarette butts, rice husk and processed waste tea into fired clay brick. This application gives an idea to use waste material that will give a minimum impact to the real environment. In this study, high calorific value waste such as cigarette butts (CBs) were incorporated into fired clay brick. Different percentages of CBs (0%, 2.5% and 5.0%) were added into the raw clay brick. All samples were fired up to 1050°C with different heating rates (1°C/min, 3°C/min and 5°C/min). Properties including compressive strength, dry density, firing shrinkage and water absorption are reported and discussed. The results show that the compressive strength of fired clay brick was obtained with 2.5% CBs of fired clay brick at 1°C/min heating rate compared to others. As for the density, it was reduced with higher percentages of CBs incorporated into the raw clays. From the results, water absorption was slightly increased when CBs were incorporated into clay brick. The results suggested that heating rates at 1oC/min is adequate to achieve optimum properties.
Effect of Surface Modification on Strain Rate Sensitivity of Polypropylene/Muscovite Layered Silicate Composites
Authors: Omar M.F. , Abd Wahab Nur Suhaili , Akil Hazizan Md , Ahmad Zainal Arifin , Rasyid Mohd Fadli Ahmad , Noriman N.Z.
Published: August 2014

Surface modification is one of the treatment methods that can be implemented to improve the strain rate sensitivity of composite materials. In this study, both untreated and treated polypropylene/muscovite layered silicate composites were tested under static and dynamic loading up to 1100 s-1 using the universal testing machine and the split Hopkinson pressure bar apparatus, respectively. Muscovite particles were treated with lithium nitrate and cetyltrimethylammonium bromide as a surfactant through ion exchange treatment. Results show that the treated polypropylene/muscovite specimens with fine state of dispersion level shows better rate of sensitivity as compared to untreated polypropylene/muscovite specimens under a wide range of strain rate investigated. Apart from that, the rate of sensitivity of both tested polypropylene/muscovite layered silicate composites also show great dependency on the strain rate sensitivity was steadily increased with increasing strain rate. Unfortunately, the thermal activation values show contrary trend. Key words: Ion exchange treatment; Strain rate sensitivity; Muscovite particles; Split Hopkinson pressure bar apparatus; Strain rates