bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Metal Catalysts Type and Annealing Time on the Growth of Zinc Oxide Nanostructures by Thermal Vapor Deposition Method
Authors: Rosli Aimi Bazilah , Yusof Khairul Aimi , Herman Sukreen Hana , Johari Muhammad Hazmi , Shariffudin Shafinaz , Ani Mohd Hanafi
Published: August 2014

This paper reports the results of zinc oxide (ZnO) nanostructure growth on different types of metal catalysts, namely gold and platinum, and also the effect of annealing time of the metal catalysts prior to the deposition of ZnO nanostructures. The metal catalysts layers with 15 nm thickness were deposited on glass substrates by sputter coater and then annealed in air ambient for 15 and 30 min at 500 °C. ZnO nanostructure was then deposited on the metal catalysts by thermal chemical vapour deposition (TCVD) method. We found that the Au catalyst morphologies varied with the annealing time, and the growth morphology of the ZnO followed the morphology of the Au catalyst. The morphology of the metal catalysts and ZnO nanostructures were characterized using field emission scanning electron microscopy (FESEM). The grown ZnO nanostructures were tested for their ability for extended gate field effect transistor (EGFET) sensor application. The samples were attached to the gate of an NFET and were dipped in acid and alkali buffer solutions while the gate voltage was measured. We found that the extended gate gave different voltage in buffer solutions with different pH which indicated that the samples can act as the extended gate of an EGFET sensor.
Effect of Oxygen Flow Rate on the Memristive Behavior of Reactively Sputtered TiO2 Thin Films
Authors: Kamarozaman Nur Syahirah , Shamsul Muhamad Uzair , Herman Sukreen Hana , Abdullah Wan Fazlida Hanim
Published: August 2014

The paper presents the memristive behavior of sputtered titania thin films on ITO substrate. Titania thin films were deposited by RF magnetron sputtering method while varying the oxygen flow rate of (O2/ (O2 + Ar) x100 = 10, 20 and 30 %) during deposition process. The effect of oxygen flow rate to the structural properties was studied including the physical thickness, and also the effect towards switching behavior. It was found that sample deposited at 20 % oxygen flow rate gave better memristive behavior compared to other samples, with larger ROFF/RON ratio of 9. The characterization of memristive behavior includes the effect of electroforming process and successive of I-V measurements are discussed.
Synthesis of CdSe Nanoparticles: Control of Reaction Temperature
Authors: Ishak Mohamad Nizam , Yaacob K.A.
Published: August 2014

Nanoparticles such as cadmium selenide (CdSe) have unique optical properties in term of band gap. These properties can be adjusted by controlling the size of nanoparticles. In this research we have synthesized different sizes of CdSe nanoparticles by controlling the reaction temperatures at 260 oC and 300 oC using a hot injection method. The as-synthesized CdSe nanoparticles were characterized using UV-visible spectroscopy and high resolution transmission electron microscope. From the UV-visible absorption spectra, the absorption peak of CdSe nanoparticles synthesis at growth temperature of 260 oC was 521 nm with estimated particle diameter of 2.57 nm, and for 300 oC the absorption peak was at 601 nm with estimated particle diameter of 4.63 nm. This indicates that the size of CdSe nanoparticles can be controlled by controlling the reaction temperature.
Effect of Calcination Temperature on the Morphological and Phase Structure of Hydrothermally Synthesized Copper Ion Doped TiO2 Nanotubes
Authors: Razali Mohd Hasmizam , Ahmad-Fauzi M.N. , Mohamed Abdul Rahman , Sreekantan Srimala
Published: August 2014

Morphological evolution and phase transformations of copper ion doped TiO2nanotubes after being calcined at different temperatures were studied by field emission scanning electronmicroscopy, transmission electron microscopy, and X-ray diffraction. After calcination at 300°C, the nanotubes with uniform diameter and length wereobtained. At 400°C, the nanotube structures were maintained. Nevertheless the inner tube diameter became narrower, and in same instances disappeared due to aggregation of nanotubes. The copper ion doped TiO2nanotubes then transformed to nanorodsat 500°C and the length of the nanorodsshortens after calcination at 600 °C. When the calcination temperature was further increased to 700°C, the nanorodsdisintegrate to form nanoparticles. On the other hand the phase structures of copper ion doped TiO2 nanotubes calcined at 300 and 400 °C were TiO2 hexagonal. After calcined at higher temperature (600 and 700°C) they transformed to anatase TiO2 (tetragonal).
Characterization of ITO/Ag and ITO/Ni Bi-Layer Transparent Conductive Electrodes
Authors: Ali Ahmad Hadi , Abu Bakar Ahmad Shuhaimi , Ahmad Mohd Anas , Zainuriah Hassan
Published: August 2014

This paper reports on ITO/Ag and ITO/Ni thin transparent conductive electrodes (TCE) for optoelectronics device applications. The ITO/Ag and ITO/Ni bi-layer TCE were deposited on Si and glass substrates by thermal evaporator and radio frequency (RF) magnetron sputtering. Post-annealing was performed on the samples at 600°C in air. Electrical, optical and morphological characteristics were investigated by means of Hall Effect measurement system, UV-Vis spectrophotometer and atomic force microscope (AFM). The measured electrical resistivity of ITO/Ag (0.5 × 10-4 Ωcm) is lower than ITO/Ni (1.2 × 10-4 Ωcm) due to the high carrier concentration of ITO/Ag of 12.0 × 1021 cm-3. Optical transmittance at visible ranges of ITO/Ag (70%) is higher than the ITO/Ni (44%). Higher surface roughness and smaller grain sizes of ITO/Ag as compared to the ITO/Ni are factors that contribute to the good quality of TCE characteristics.
Biocompatibility and Efficacy of Five-Channel and Eight-Channel Crosslinked Urethane-Doped Polyester Elastomers (CUPEs) as Nerve Guidance Conduit for Reconstruction of Segmental Peripheral Nerve Defect Using Rat Model
Authors: Ho Angela W.H. , Ip W.Y.
Published: August 2014

Introduction: Peripheral nerve injury is common in clinical practice. Nerve defect is a challenging scenario. The current gold standard of managing a nerve defect is autologous nerve graft. However, due to the selection of nerve graft and donor site morbidity, artificial nerve conduits are gaining popularity. However, there are drawbacks of single hollow conduit such as lack of internal support to prevent conduit collapse and inability so as to recreate the proper native spatial arrangement of cells and extracellular matrix within the conduit. In this study, the biocompatibility and efficacy of five-channel and eight-channel Crosslinked Urethane-doped Polyester Elastomers (CUPEs) as nerve guidance conduit will be evaluated through a rat model with reconstruction of segmental peripheral nerve defect. Material and Method: Eighteen adult Sprague-Dawley rats were used. They were randomly allocated to three groups: autograft group, five-channel conduit group and eight-channel conduit group with each consisted of six rats. A 10mm nerve defects were created at the right sciatic nerve. They were bridged with reverse autograft, 5-channel conduit and 8-channel conduit. After eight weeks the rats were euthanized and the reconstructed nerves were harvested for histomorphometric analysis. Result: All conduits showed regenerated nerve tissue inside. There was no collapse of the conduits. There were no severe tissue reaction or scarring near the reconstructed nerve. No neuroma was formed. Histomorphometric analysis showed nerve regeneration was enhanced with increasing number of channels inside conduit. There was overall drop in fiber density between proximal and distal segment among all groups. Conclusion: CUPE nerve guidance conduit is biocompatible and shows good nerve regeneration in reconstructing nerve defect.
VSC Adsorption Capability of Layered Double Hydroxide Containing Transition Metal
Authors: Yokogawa Yoshiyuki , Sano Hiroya , Namba Shota , Fujii Kazuo , Morita Yuki , Hotta Masato , Doi Yutaka
Published: August 2014

Many people worldwide assess themselves as having halitosis, often caused by bio-film and microbial putrefaction of the debris in the mouth, leading to the production of mal-odorous compounds, volatile sulfur compounds (VSC) such as hydrogen sulfide (H2S), methyl mercaptan and dimethyl sulfide. Some desulfurizing agents such as CaO and Na2CO3 in the industry are widely used, but there are few dental desulfurizing agents or adsorbents for removal of VSC. Ag ion exchanged zeolite material showed a high adsorptive property of H2S in aqueous solution (H2S water), however Ag sulfides were formed in aqueous solution. The VSC adsorption capabilities of layered double hydroxides, of which composition is A1-xAlx(OH)2Bx/n·mH2O, where A is Mg and/or Zn and B is CO32-, in aqueous medium was studied by FPD/GC. The concentration of H2S fell to 0% in 2 h when the Zn hydrotalcite was used, while that decreased to 20% in 18 h when the Mg hydrotalcite heated at 500 °C was used. The zinc ion was not detected in the H2S water after soaking for 18 hours.The Zn hydtotalcite is expected to be likely adsorbent for the fast removal of VSC from the mouth.
Biomimetic Model of Articular Cartilage Based on In Vitro Experiments
Authors: Smyth Patrick A. , Green Itzhak , Jackson Robert L. , Hanson R. Reid
Published: August 2014

Articular cartilage is a complicated material to model for a variety of reasons: its biphasic/triphasic properties, heterogeneous structure, compressibility, unique geometry, and variance between samples. However, the applications for a biomimetic, cartilage-like material are numerous and include: porous bearings, viscous dampers, robotic linkages, artificial joints, etc. This work reports experimental results on the stress-relaxation of equine articular cartilage in unconfined compression. The response is consistent with simple spring and damper systems, and gives a storage and loss moduli. This model is proposed for use in evaluating biomimetic materials, and can be incorporated into large-scale dynamic analyses to account for motion or impact. The proposed characterization is suited for high-level analysis of multi-phase materials, where separating the contribution of each phase is not desired.
Metatarsal Horizontal Angle Variety Information of Female with Different Hallux Valgus
Authors: Li Feng Ling , Zhang Yan , Liang Min Jun , Li Jian She , Gu Yao Dong
Published: August 2014

Hallux valgus is a common foot deformity with a multifactorial etiology. Factors associated with the development of hallux valgus (HV) are multifactorial and the etiology of hallux valgus remains unclear. The purpose of this study was to measure the biomechanical relationship between Hallux Valgus Angle (HVA), intermetatarsal Angle (IMA), Interphalangeal Angle (IPA), and metatarsal horizontal angle, in order to reveal the tendency of metatarsal horizontal angle along with hallux valgus angle increasing. Foot models of nine subjects are built through CT scan and editing software and calculated metatarsal horizontal angles using motion analysis system. It showed that with the increased of HVA, the metatarsal horizontal angle of the first to fifth was decreased. This method and results maybe have a new sight to reveal the characters of HV patients. Keywords: Hallux valgus; Metatarsal horizontal angle; Foot Models
Morphological, Typological and Structural Characters of the Old Centers in the Center of Coastal Apulia: Some Instruments for the Safeguard and the Recovery of their Architectural Heritage
Authors: Riondino Antonio Vito
Published: August 2014

This study aims to give a contribution to the knowledge, and the use of it, in the safeguard and recovery of the architectural heritage of the old center in the center of coastal Apulia. It is an area characterized by settlement processes that, even though have been combined by the different specific situations, shape this territory as an homogeneous geographic-formal area.
Dynamic Testing of Masonry Towers Using the Microwave Interferometry
Authors: Gentile Carmelo , Saisi Antonella
Published: August 2014

Microwave remote sensing is the most recent experimental methodology suitable to the non-contact measurement of deflections on large structures, in static or dynamic conditions. After a brief description of the radar measurement system, the paper addresses the application of microwave remote sensing in ambient vibration testing of two historic masonry towers.
A NN-Based Approach for Monitoring Early Warnings of Risk in Historic Buildings via Image Novelty Detection
Authors: Carnimeo Leonarda , Nitti Rosamaria
Published: August 2014

Architectural heritage is an important part of the history and identity of countries, but ancient buildings suffer a high vulnerability to hazards, which may induce unpredictable damages. For this purpose, the development of techniques for monitoring historic buildings and immediately alerting in case of early vulnerability assessment is a main objective to be pursued. This paper concerns with a proposal of noninvasive Neural Network-based approach for predicting risk events in artistic buildings. More in detail, a neural approach is suggested for detecting temporal novelties in images of historic evidences with the aim of monitoring early warning of risk events.
Hearing the Buildings: Smart Monitoring through Advanced Sonification Approaches
Authors: Floros Andreas , Vlamou Elena , Chrissikopoulos Vassilios
Published: August 2014

Risk prevention of historical buildings through sensor network monitoring represents a challenging and together promising task towards an optimized buildings’ protection plan. Due to the significant character that historical buildings have within the history and identity of local and consequently national communities, the monitoring approach above is nowadays considered a fundamental component of cultural preservation. Modern trends on sensor networks nowadays allow the installation of wireless monitoring equipment, able to collect a large volume and variety of data that can be further processed in order to support prevention modelling techniques and strategies. Despite the valuable post-processing outcome of the above modelling techniques, in several real-time monitoring cases, an aspect that may significant impact the data analysis accuracy from the monitoring engineer is to create an audiovisual representation of the gathered data that are easily perceived and directly associated to well-known environmental conditions. Towards this aim, in this work an audio-based representation of the collected data is introduced that achieves high monitoring performance in terms of the perceived nature of the building vibrations themselves. The proposed audio-based representation technique is based on a number of advanced sonification methods, combined with specific human-hearing simulation mechanisms that allow an effective increase of the represented information volume in real-time. A number of subjective tests that were performed demonstrate a significant improvement on the way that the monitoring personnel can efficiently perceive the origin and / or nature of the acquired vibrations, rendering the proposed technique a strong supplement towards efficient historical building risk prevention.
Hybrid Model for Measurement of Building Vulnerability
Authors: Vlamos Panayiotis , Pateli Adamantia , Psiha Maria
Published: August 2014

In this paper a hybrid model for measurement of building vulnerability caused by strong motion arrays is proposed. Our model is based on is a multi-disciplinary method that will predict the behavior of a building structure in reaction to unforeseen stress. In addition, we classify the already proposed vulnerability assessment methods and we describe the criteria for the appropriate selection of building vulnerability assessment method.
URFA: The Planned City and the Process of Medievalization
Authors: Ieva Matteo
Published: August 2014

One of the main objectives of this study is to search for the verification of a hypothesis. It is an attempt to understand if it is possible to apply the method developed by the Italian School of Typology to read the planned city of Western Europe to other parts of the world and to investigate if this way of planning can also be extended to other zones that have different geographical and cultural properties. Urfa, in fact, is believed to provide a fertile ground with its multi-cultural structure for such a research. It is a city situated in the southeast Turkey, which displays both the characteristics of Turkish and Syrian cultures. The analysis was conducted in various scales; that is, the territorial organism, the urban organism, the aggregative organism and the building organism. The graphic instruments were preferred to be the historic maps above all, the plan that regulates the city and the cadastral maps showing the actual situation that also indicate the recent developments and the distruction of the urban tissue. These reading instruments have been too limited and heterogeneous with respect to what we usually use. Therefore the releif of the most ancient part of the city has been made by the students.1
Dynamic Monitoring and Seismic Response of a Historic Masonry Tower
Authors: Saisi Antonella , Gentile Carmelo , Guidobaldi Marco , Xu Man
Published: August 2014

After the Italian earthquakes of May 2012, an extensive research program had been performed to assess the state of preservation of the tallest historic tower in Mantua, Italy. Subsequently, a continuous dynamic monitoring system was installed in the tower, with seismic and structural health monitoring purposes. After a brief description of the investigated tower and its state of preservation, the paper summarizes some results of the long-term dynamic monitoring.
Strength Performance of Unreinforced Brick Masonry Walls under Flexo-Compression Load. Analytical Methods
Authors: Bernat-Maso Ernest , Gil Lluís
Published: August 2014

The structure of many historical buildings relies on unreinforced masonry load-bearing walls. In the case of large slenderness or significant eccentricity of the vertical compressive loads the mechanism formation failure mode is likely. Considering the second order bending effects and the tensile strength of the masonry is essential to accurately calculate the load-bearing capacity of these structures, which is required for maintenance tasks. An analytical methodology has proposed with this aim. This original method, the Southwell plot method and the formulations from two standard codes (ACI-530 and Eurocode-6) are applied to calculate the resistance of 18 experimentally tested walls to conclude that the proposed methodology brings correct results, the standards are conservative and the Southwell plot method is the most suitable for the analysis of the considered cases but it is not always applicable.
One-Year Monitoring of a Historic Bell Tower
Authors: Cantieni Reto
Published: August 2014

In 2003, people working in the San Luzi, Zuoz, bell tower reported excessive tower vibrations when ringing bells. Zuoz is a village in the Upper Engadin Valley, Switzerland. Measurements performed in 2004 showed a maximum tower vibration velocity amplitude of 16 mm/s which is more than five times the acceptable value ([1], [2], [3]). In 2008 the two large bells (out of four) were equipped with cranked yokes and their pendulum frequency was reduced to get a larger distance to the tower natural frequency. Measuring again in 2009 yielded the two large bells no longer exciting large tower vibrations. However, this was not true for bell No. 3. Subsequently, this bell's pendulum frequency was also reduced. In 2011, measurements showed that this last measure had negative instead of positive effects. And, now disposing of three values, the tower natural fundamental frequency was found to be somewhere in the f = 1.43...1.50 Hz region. It was then decided to monitor the tower dynamic behavior for one year to get reliable information on the natural frequency scatter. Monitoring started June 11, 2012, and ended October 7, 2013. The results: a) The tower fundamental frequency varied in an f = 1.42...1.59 Hz range, b) The tower is stiffer in winter than in summer, c) On a daily or weekly schedule, the tower fundamental frequency is following the temperature curve: increasing stiffness with increasing temperature and vice versa. A possible explanation for this contradiction is given. Due to space restrictions, also monitored bell ringing excited tower vibrations can not be discussed here.
Properties of Lightweight Bubbles Aggregate (LBA) for the Replacement of Coarse Aggregates in Concrete
Authors: Ibrahim Norlia Mohamad , Wen Leong Qi , Che Amat Roshazita , Abdul Majid Taksiah , Rahim Nur Liza , Shamsuddin Shamshinar
Published: August 2014

The depletion of natural resources in the production of coarse aggregate are very crucial. Construction materials are solely depends on natural granite in the making of cement composite. Therefore , there is an urgency need to develop new alternatives material that can replace the usage of granite in concrete production. In this study, LBA have been produced to cater this problem. It is made from a mixture of bubbles from foam and ordinary portland cement. The ratio of the raw materials used is 1 part of bubbles and 2 part of ordinary Portland cement. Its manufacturing process does not involving any sintering process so it will part help to reduce energy comsuption at about 30%. The properties and characteristics of the LBA such as density, specific gravity, water absorption, strength were investigated. Results shown that the specific gravity of LBA was 1.00, water absorption was 19.44%, dry bulk density was between 730 – 800 kg/m3 and dry loose bulk density was ranged from 700 to 730 kg/m3 and the strength of aggregates is 14.00 MPa. It is found that the LBA can be used as a partial replacement of granite in the production of concrete. Keywords: LBA, concrete, density
Fundamentals of Geopolymers and Related Alkali Activated Materials
Authors: Temuujin J. , Minjigmaa A. , Bayarzul U. , Zolzaya Ts. , Davaabal B. , Amgalan J.
Published: August 2014

With the increasing rate of depletion of natural raw materials for production of building materials, their sustainable usage is clearly an important topic for consideration. For instance, 1 tonne ordinary Portland cement (OPC) requires 1.7 tonnes of raw materials, 1.0 tonne of coal and 100 kWh of electricity. One tonne of cement emits 0.8 - 1 tonne of CO2 into atmosphere globally contributing ~5% of total manmade carbon dioxide. Therefore, the development of new, sustainable, low carbon footprint construction materials is an important task for materials scientists and civil engineers. One type of binder that is attracting particular attention around the world is alkali-aluminosilicate chemistry based material the so-called geopolymers.
In this presentation we will discuss the fundamentals of geopolymer chemistry and the similarities to and differences from conventional alkali activated materials chemistry.
Particular attention will be given to our latest results on the preparation of geopolymer type paste and concrete from fly ash. Mechanical activation of fly ash caused a decrease in porosity with a partial amorphisation of the crystalline constituents. Geopolymer type paste prepared from 30 minute milled Darkhan pond ash showed increase in 7 day compressive strengths by 7 times reaching of 15.4 (4.6) MPa.
Keywords: Geopolymer binder, alkali-activated materials, coal combustion by products
Utilization of Recycled Glass Waste as Partial Replacement of Fine Aggregate in Concrete Production
Authors: Rahim Nur Liza , Che Amat Roshazita , Ibrahim Norlia Mohamad , Salehuddin Shamshinar , Mohammed Syakirah Afiza , Abdul Rahim Mustaqqim
Published: August 2014

Glass dust waste creates chronic environmental problems, mainly due to the inconsistency of waste glass streams. Glass is widely used in our lives through manufactured products such as sheet glass, bottles, glassware, and vacuum tubing. Glass is an ideal material for recycling. The use of recycled glass helps in energy saving. The increasing awareness of glass recycling speeds up inspections on the use of waste glass with different forms in various fields. One of its significant contributions is to the construction field where the waste glass was reused for concrete production. The properties of concretes containing glass dust waste as fine aggregate were investigated in this study. Glass dust waste was used as a partial replacement for sand at 10%, 20% and 50% of concrete mixes. Compression strength for 7, 14 and 28 days concrete of age were compared with those of concrete made with natural fine aggregates. The results proved that highest strength activity given by glass dust waste after 28 days. The compressive strength of specimens with 10% glass dust waste content were 32.9373 MPa, higher than the concrete control specimen at 28 days. Using glass dust waste in concrete is an interesting possibility for economy on waste disposal sites and conservation of natural resources.
Effect of Sodium Silicate Types on the High Calcium Geopolymer Concrete
Authors: Ridzuan A.R.M. , Khairulniza A.A. , Arshad M.F.
Published: August 2014

Geopolymerization is an innovative technology that can transform several solid aluminosilicate materials into useful products called geopolymers. Alkali activation of aluminosilicate precursors such as waste or by-product materials from other manufacturing processes is established as one of the methods of producing sustainable binders for construction. Most of previous studies focus on low calcium pozzolanic material and very little study on high calcium material. Waste Paper Sludge Ash (WPSA) were used as main pozzolanic material in this present study. The high-calcium WPSA essentially consists of aluminosilicate modified by the presence of large amounts of calcium. It can be categorized as cementitious and pozzolanic material when Calcium Oxide (CaO) varies between 10% and 20% or greater than 20%. The chemical composition of the WPSA used in this study contains approximately 53% of CaO, this value consider very high compared with other high calcium material used by other researchers. Alkali (Na or K) hydroxides or silicates are generally used as the activating agents. Based on previous geopolymerization studies, it was estimated that the most important production cost factor is the cost of used chemicals and especially the one of Sodium Silicate (Na2SiO3) solution. Sodium Silicate (Na2SiO3) are usually used as a alkaline activators in geopolymerization process. Na2SiO3 comprises a fundamental process in geopolymerization technology. Therefore, this study aims at experimentally the polymerization stage in Na2SiO3. In this study of geopolymer concrete using powder Na2SiO3 (which makes handling easier in practice and more economic) and compares it with waterglass (liquid Na2SiO3). In this study, WPSA and alkaline liquid are being used to replaced the Portland cement to produce geopolymer concrete. The alkaline liquid that been used is the combination of sodium hydroxide (NaOH) and Na2SiO3. Two (2) series of geopolymer concrete specimens composing two (2) different type of Na2SiO3 which are powder form solution (4 Molar) and waterglass ( ready made liquid form) were adopted. In addition, present study also examined the effect of using Recycle Concrete Aggregate (RCA) to produced more green concrete. There are 144 cube specimens at size 100mm x 100mm x 100mm were prepared. The compressive strength of the geopolymer concrete specimens is tested at the age of 3, 7, 14 and 28 days after cured in local laboratory ambient condition. The chemical analysis using XRF/XRD and morphorlogical structure view from SEM/EDX also been examined. The result shows that the silicate phases were characterized as X-ray amorphous to semi-crystalline structures materials and the strength effect using these both silicate types (liquid and powder) are not much differ. Consequently, more economic production of geopolymers by used Na2SiO3 solution (powder) for geopolymer production.
The Effect of NaOH Concentration and Curing Condition to the Strength and Shrinkage Performance of Recycled Geopolymer Concrete
Authors: Ridzuan Ahmad Ruslan Mohd , Al Bakri Abdullah Mohd Mustafa , Arshad Mohd Fadzil , Mohd Tahir Muhammad Faheem , Khairulniza A.A.
Published: August 2014

Concrete is widely used as a material construction. Globally, the consumption of concrete was estimated to be more than 8 billion tons per year. Nowadays, many problems arise related to concrete manufacturing occur especially on environmental issues. A key concern for environmentalists has always been climate change. One of the ways to mitigate the impact activities on the climate is to reduce carbon footprint. Portland cement are commonly been used in concrete is responsible for about 5% of all CO2emission. It is reported by Davidovit that the production of one ton of Portland cement emits approximately one ton of CO2into the atmosphere. There are several ways to reduce environmental pollution that cause by production and utilization of Portland cement, one of it is Geopolymer concrete. Subsequently Geopolymer concrete incorporating with recycle concrete aggregate (RCA) is one of the alternative to further reduce carbon footprint and as well as can reduce waste. Geopolymer concrete is a concrete that use no cement and produced by the combination of alkaline activator and supplementary cementitious material (SCM) such as fly ash, boiler ash, waste paper sludge ash (WPSA), ground granulated blast-furnace slag (GGBS), and so on in order to reduce carbon emission. In this study the Waste Paper Sludge Ash (WPSA) were used as a SCM and the combination of sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) as a binder. Two (2) series of geopolymer concrete specimens comprising two (2) different molar of sodium hydroxide (NaOH) which are 8M and 14M were adopted. The effect variable alkaline molarity on the compressive strength and shrinkage of the geopolymer concrete specimens is tested at the age of 3, 7, 14 and 28 days. The mixture of geopolymer concete with 8M of sodium hydroxide (NaOH) concentration then was categorized into three (3) groups. Each group were been cured at different curing condition which are in ambient condition, oven, and external condition. The size of specimens prepared were 100mm x 100mm x100mm. The result shows that the molarities of sodium hydroxide (NaOH) influenced the strength of Waste Paper Sludge Ash (WPSA) based geopolymer concrete produced incorporating with increasing of recycle concrete aggregate (RCA). The result also show that the geopolymer concrete undergoes very low shrinkage. Curing condition will also effect the strength of geopolymer concrete produced.
Study on Quenching and Artificial Ageing on Al-Si Alloy
Authors: Achitei Dragoş Cristian , Sandhu Andrei Victor , Abdullah Mohd Mustafa Al Bakri , Vizureanu Petrică , Kamarudin Hussin
Published: August 2014

Aluminum alloys have special advantages on the structural changes induced by thermal treatments. Thus, for proper machining a solution quenching is applied, when the hardness and the tensile strength of the alloy decreases. In order to restore the properties natural or artificial ageing is necessary.
Development of Low Cost Sn-0.7Cu Base Composite Solder for High Temperature Application
Authors: Mahim Zawawi , Saud Norainiza , Razak Nurul Razliana Abdul
Published: August 2014

This research has investigated the advantages of Sn-0.7Cu composite solder compared to conventional Sn-0.7Cu solder. The method used for fabricating the composite solder is a powder metallurgy (PM) technique. SiC and Al particles were added to Sn-0.7Cu powder during the mixing process. The Sn-0.7Cu solder composite that reinforced with 0.25 wt% of SiC and 0.5 wt% of Al, were successfully synthesized via PM technique. The result showed that the addition of SiC and Al were improving the mechanical properties and thermal stability of the solder as well as reduces the material cost.
Thermal Properties of Polypropylene/Palm Kernel Shell Biocomposites: Effects of Amino Silane (APTES)
Authors: Mohamed Omar Murad Salem , Ong Hui Lin , Akil Hazizan Md , Nik Nur Azza N.A. , Safwan M. Muhammad , Sofiah M.K. Anis
Published: August 2014

Effects of 3-aminopropyltriethoxysilane (APTES) as coupling agent on thermal properties of Polypropylene/Palm Kernal Shell (PP/PKS) biocomposites were studied. PKS with different filler loading (5, 10, 15, 20 and 25 wt %) were added into polypropylene matrix and were compounded using hot melt blending method. Thermogravimetric Analysis (TGA) result shows a higher thermal stability of amino silane modified fillers (10% filler loading). Percentage of crystallinity for PP/PKS composites increased after adding amino silane due to better dispersion of filler and the ability of coupling agent to enhance compatibility between PKS and polypropylene hence it increases the nucleation site.
Design of Experiment (DOE) of Powder Metallurgy Technique in Fabricating SnCu/Carbon Lead-Free Composite Solder with Different Mixing Parameters
Authors: Musa Sayyidah Amnah , Saud Norainiza
Published: August 2014

Physical and mechanical properties of a solder joint will be improved by adding the high performance of reinforcement particulates in the monolithic lead-free solder. In this study, 0.1wt% of activated carbon (AC) was added into Sn-0.7Cu lead-free solder which fabricated via powder metallurgy (PM) techniques. Various parameters used in PM technique such as mixing time, compacting load and sintering temperature has been carried out in fabricating the composite solder. In this study, the best mixing time has been optimized. The distribution of carbon in SnCu matrix for each mixing time was observed by using optical microscope. Microstructural observation showed that the increasing in mixing time has increased the number of AC particles to become agglomerated. It is found out that 1hour of mixing time is the best parameter to fabricate SnCu/AC composite solder via powder metallurgy route since the distribution of reinforcement particles has distributed uniformly at the grain boundaries without any agglomeration.
Treatment Method for Dispersion of Carbon Nanotubes: A Review
Authors: Sinar A.A. , Nur Azni Mohd Azizan , Zainuddin Firuz , Hazizan Md Akil , Siti Shuhadah M.S. , Sahrim H.A.
Published: August 2014

Polymer nanocomposites have a great interest because of special properties of carbon nanotubes (CNTs) as excellent for mechanical, chemical, electrical and thermal properties. CNTs are categorized as single walled nanotubes (SWCNTs) and multi walled nanotubes (MWCNTs). The largest challenge is how to achieve uniform distribution of CNTs within the polymer matrix due to CNTs tend to agglomerated because of their hydrophobic nature. The resulted from CNTs bundles or aggregates reduced the mechanical performance of the final polymer nanocomposites. The surface of the CNTs must be modifiy to reduce the hydrophobicity and improved the interfacial adhesion to a bulk polymer. This paper reviewed the two (2) treatments of CNTs such as physical methods and chemical methods to obtain a better dispersion and enhance the CNTs properties in polymer nanocomposites.
Hybrid Microwave-Assisted Rapid Sintering Process for Fabrication of Sn-0.7Cu+1.0wt.%Si3N4 Composite Solder
Authors: Somidin Flora , Saud Norainiza , Mohd Salleh Mohd Arif Anuar
Published: August 2014

Hybrid microwave-assisted powder metallurgy sintering process is an emerging technology in synthesizing composite solder. In this study, a combination of microwave-energy heating and radiant heating from SiC crucible (so called hybrid heating) for the powder metallurgy sintering process for fabrication of Sn-0.7Cu+1.0wt.%Si3N4 composite solder was developed. The influence of different microwave power output with and without SiC crucible on the heating rate was measured. The effect of the increasing microwave exposure time on the microhardness values of Sn-0.7Cu+1.0wt.%Si3N4 composite solder sintered pellets were also measured to correlate the effect of heating behavior of the hybrid microwave-sintering and the present of the sintering mechanism within the green compact samples. It can be observed that the increasing of microwave power output has marginal effect to the heating rate of the setup. Higher heating rate using optimum power output (800 W) can be realized with the present of SiC crucible (susceptor material). The results revealed that the microhardness of the Sn-0.7Cu+1.0wt.%Si3N4 green compact decreases as microwave exposure time is increased. While, minimal microhardness value changes after 3 minutes (230 oC) using the 800 W of microwave exposure time.
Investigation of Epoxidized Natural Rubber (ENR 50) as a Compatibilizer on Cogon Grass Filled Low Density Polyethylene/Soya Spent Flour
Authors: Sam S.T. , Hani Nurul , Ismail H. , Noriman Nik , Ragunathan S.
Published: August 2014

Natural fiber reinforced composites are increasingly being used in various applications area. Therefore, the processing method and physical properties of these composites are very important parameters in product quality and quaranty. This paper focused on the tensile properties, Fourier transform infrared (FTIR) and water absorption of cogon grass (CG) with low density polyethylene (LDPE)/soya spent flour (SSF) composites. The tensile strength and elongation at break (Eb) of uncompatibilized CG with LDPE/ SSF decreased significantly with increasing of fiber content. However, the Young’s modulus increased with increasing of CG loading. The presence of epoxidized natural rubber (ENR 50) as a compatibilizer increased the tensile strength, Eband Young’s modulus of the composites when compared to uncompatibilized composites. Fourier transform infrared results show distinguishable peaks for compatibilized and uncompatibilized composites. The water absorption for both uncompatibilized and compatibilized composites increased from day 1 until day 21. The presence of ENR 50 as compatibilizer showed lower water absorption percentage compared to uncompatibilized composites.
The Effect of Si/Al Ratio and Sodium Silicate on the Mechanical Properties of Fly Ash Based Geopolymer for Coating
Authors: Asif Afshan , Man Zakaria , Mohd Azizli Khairun Azizi , Nuruddin Muhd Fadhil , Ismail Lukman
Published: August 2014

The present study has been performed to see the effect of varying Si/Al ratio (1.85 to 3) by using same concentration of NaOH and same solid/water ratio for the development of mechanical properties at 28 days of room temperature and also select the Si/Al ratio for coating application. The performance of the geopolymer was investigated on the basis of compressive strengthSEM along with EDS. Pure sodium hydroxide specimens displayed decreased strength. However the combination of sodium hydroxide and sodium silicate specimen with aSi/Al ratio of 2 showed maximum strength, whereas the specimen after Si/Al ratio 2 showed decrease in strength.
Effect of Particle Size on Properties of Sidoarjo Mud-Based Geopolymer
Authors: Antoni  , Wiyono David , Vianthi Agie , Putra Permana , Kartadinata Gary , Hardjito Djwantoro
Published: August 2014

The eruption of Sidoarjo mud volcano that has been taken place since 2006 had caused significant damage to the local social environment, and until now there is no immediate solution that can be offered. Utilization of the Sidoarjo mud as construction material recently has gained some advancement by calcination of the mud, that make the previously inert material to become more reactive and to be more viable for its use as cement replacement or geopolymer precursor. This paper reports an on-going study to utilize the Sidoarjo mud as precursor of geopolymer by investigating the influence of particle size on the reactivity of the calcined Sidoarjo mud. Furthermore, durability properties of Sidoarjo mud-based geopolymer was also studied. The results show that making finer the mud particles by milling in longer period, using a rod-mill drum for 8 hours, can increase the reactivity of the mud. Compressive strength of geopolymer mortar can increase up to 155% when compared to the ones based on milling time of only 2 hours. Durability properties of sulphate acid resistance and chloride penetration are comparable to fly ash-based geopolymer, while the shrinkage measurement showing higher value.
Hybridization Effect of Kaolin and Calcium Carbonate on Tensile and Thermal Properties of Compatibilized Polypropylene Composites
Authors: Faheem M.T. Muhammad , Safwan M. Muhammad , Al Bakri A.M. Mustafa
Published: August 2014

In this study, effect of combination between two fillers, Kaolin and Calcium Carbonate into Polypropylene (PP) composites was investigated. Hybrid thermoplastic composites from Kaolin and Calcium Carbonate were manufactured via melt mixing process involving Brabender internal mixer. Polypropylene grafted Maleic Anhydride (PP-g-MA) was also blend together with Polypropylene and both fillers during melt mixing. Single filler system composites were also introduced in this study in order to have comparison with hybrid filler system composites. Tensile, morphological and thermal properties of hybrid composites were discovered by Instron 5569 tensile testing machine, scanning electron microscopy (SEM) and thermogravimetric analyzer (TGA). Tensile test shows that additional of two fillers, kaolin and calcium carbonate could increase the strength and modulus of PP matrix. Calcium carbonate gives better strength and modulus for PP matrix compared to kaolin. However, the usage of calcium carbonate and kaolin deteriorate the elongation at break of PP matrix. The usage of two different fillers also embellish PP matrix by improve the thermal stability of the composites.
The Cross-Priming Capacity and Direct Presentation Potential of an Autoantigen Are Separable and Inversely Related Properties
Authors: Wang Jinguo , Nanjundappa Roopa Hebbandi , Shameli Afshin , Clemente-Casares Xavier , Yamanouchi Jun , Elliott John F. , Slattery Robyn , Serra Pau , Santamaria Pere
Published: August 2014

We investigated whether a prevalent epitope of the β-cell–specific autoantigen islet-specific glucose-6-phosphatase catalytic subunit–related protein (IGRP206–214) reaches regional Ag-presentation pathways via unprocessed polypeptide chains, as free IGRP206–214 peptide or via preformed IGRP206–214/Kd complexes. This was accomplished by expressing bacterial artificial chromosome transgenes encoding wild-type (stable) or ubiquitinated (unstable) forms of IGRP in IGRP-deficient NOD mice carrying MHC class I–deficient β-cells, dendritic cells, or B cells. We investigated the ability of the pancreatic lymph nodes of these mice to prime naive IGRP206–214-reactive CD8+ T cells in vivo, either in response to spontaneous Ag shedding, or to synchronized forms of β-cell necrosis or apoptosis. When IGRP was made unstable by targeting it for proteasomal degradation within β-cells, the cross-priming, autoimmune-initiating potential of this autoantigen (designated autoantigenicity) was impaired. Yet at the same time, the direct presentation, CTL-targeting potential of IGRP (designated pathogenicity) was enhanced. The appearance of IGRP206–214 in regional Ag-presentation pathways was dissociated from transfer of IGRP206–214 or IGRP206–214/Kd from β cells to dendritic cells. These results indicate that autoantigenicity and pathogenicity are separable and inversely related properties and suggest that pathogenic autoantigens, capable of efficiently priming CTLs while marking target cells for CTL-induced killing, may have a critical balance of these two properties.
Mouvement glaciaire vers le nord sur le piémont laurentien dans la région de Québec, Québec
Authors: Paradis S J , Bolduc A M
Published: August 2014

A survey of glacial flow indicators in the Québec City area has revealed the presence of a northward movement as far as the edge of the Laurentians to an elevation of about 200 m. This could indicate a late-glacial advance of Appalachian ice to the
Laurentian Piedmont on the north shore of the St. Lawrence River. This young, northward movement adds a new element to the general chronology of ice flow in the region: initial ice flow to the south-southwest, followed by flow to the southeast. A recovery towards the east, followed by another shift
to the southeast, could be linked to the development and disappearance of an ice stream and a calving bay in the St. Lawrence Valley. This phase was followed by a final, local, northward flow originating from the Appalachians.
Evaluation of detectors and probe housing for borehole spectral gamma-gamma logging
Authors: Mwenifumbo C J , Elliott B E
Published: August 2014

Three scintillation detectors; sodium iodide, cesium iodide, and bismuth germanate (BGO) were evaluated with particular reference to the detection of low-energy g- rays in borehole spectral g-g (SGG) logging applications. The spectral response characteristics of
a low-atomic- number (Z), fibreglass probe housing was also compared to stainless steel, a high-Z probe housing. Direct g-rays from low-energy barium and medium-energy cesium g-ray sources, and backscattered g-rays from a cobalt source, were used to evaluate the detector and probe-housing
performances. The BGO detector has the worst energy resolution; however, it is more efficient at stopping g- rays. The stainless-steel probe housing significantly attenuates the low-energy g-rays, making it difficult to detect changes in the spectral shape related to variations in the distribution
of heavy elements. Stainless steel is, therefore, a poor choice as a probe housing. The attenuation of low-energy g-rays through the fibreglass probe housing is slight, making it a better choice for SGG logging.
Geological landscape of the pre-Inca archeological site at Chavin de Huantar, Peru
Authors: Turner R J W , Knight R J , Rick J
Published: August 2014

Chavin de Huantar, a large pre-Inca temple complex in a steep-walled mountain valley, was constructed on three geomorphic elements: the toe of an inactive earthflow, an alluvial fan, and a river floodplain. Part of the temple complex suffered river-bank erosion
early this century and structures indicate ancient Chavin inhabitants attempted to control river position. The temple complex and nearby valley floor was buried by a damaging debris flow in 1945. A nearby agricultural plain that likely influenced the siting of the temple complex represents an
ancient landslide-dammed lake floor.
The temple is constructed of large stone blocks, mostly sandstone and quartzite with lesser granite, limestone, and volcanic tuff. Sandstone and volcanic tuff could have been quarried locally but the nearest sources for limestone and granite are 3 km and 15 km from the site.