bluuebunny/crossref_metadata_2025 huggingface dataset:
Solubility of Phoenix dactylifera Seed Oil in Supercritical Carbon Dioxide (Sc-Co2) Using Empirical Model
Authors: Aris Nor Aiysah , Norhuda I. , Adeib Idris S.
Published: December 2013

Phoenix dactylifera L. type Mariami from Iran was chosen for this study to investigate the solubility of its seed oil in supercritical carbon dioxide (SC-CO2). The seed has been discovered to possess an antioxidant. The extraction method using SC-CO2 solvent was used in this study to investigate the capabilities of supercritical fluid to extract Phoenix dactylifera L. seed oil since the method is clean compared with organic solvent extraction. Solubility of Phoenix dactilyfera seeds oil in SC-CO2 was correlated using empirical density based model with the help of IBM SPSS software for significance and correlation analysis of the models. Analysis of component in the oil was done using gas chromatography equipped with mass spectrometry (GC-MS). Oleic acid revealed to be the main fatty acid in Phoenix dactylifera seed oil, followed by palmitic acid, lauric acid, ascorbyl palmitate and others.
Effect of Different Nickel Content on the Mechanical Properties of Hydroxyapatite-Ni Composites from Coated Powders
Authors: Amin Sri Asliza Md , Zaheruddin Kasmuin Mohd , Azmi Rahmat , Jamaludin Shamsul Baharin , Khairel R.A.
Published: December 2013

HA-Ni composites were fabricated by uniaxial pressing from coated powders, in which HA particles were successfully coated with nickel precursor by the electroless deposition method. The compacted powders sintered at temperature 1200°C for 1h. Decomposition of hydroxyapatite into α-TCP (α tricalcium phosphate) and TTCP (tetracalcium phosphate) were not occured in any different nickel content before and after sintering. The Ni peaks sharply increased with increasing of Ni content indicate that high crystallinity of metal and confirmed the existence of nickel in the composites. Compared with that of pure HA, the fracture strength of HA inproved by almost 200% by adding 1wt% Ni due to the increase of the composites density. The enhancement in mechanical properties of HA-Ni composites was found to decrease with increase of Ni content, which attributed to the size effect of nickel grains and higher porosity percentage of composites.
Design and Optimization of a Monomer Processing Reactor
Authors: Rus Anika Zafiah M. , Isa Muhamad Soqhimi Mohamad , Yaanuur Syaafa’at S. , Masli E.S.
Published: December 2013

The purpose of this research is to design and to modify a monomer reactor tank in order to achieve higher output production of bio-monomer. The main aspect of this design is based on producing good quality and higher yielding of monomer. The design was started on lab scale process of 2L beaker into a 5L reactor. The most important point of the design is to produce larger amount of monomer as compared to lab scale equipment. Selecting material is vital on the process and cost for fabricating the reactor. It is to prevent chemical corrosion on the reactor and to produce higher yield of monomer with cost effective way. The optimization and analysis of the design and materials of a reactor were based on influence of heat and chemical resistance on the reactor. The design and analysis process were done using Solidworks and chemical resistance were based on the standard chemical chart for common materials used for a reactor. The best material for the reactor is Stainless Steel 316 based on chemical chart, heat resistance and cost effective. The yielding of monomer is more than 100% by lab scale method with predetermined controlled parameters of stirring speed and temperature. There were small differences between every samples. At 80°C, the yielding of monomer is the highest while the by product (water) is the lowest. Meanwhile, at 60°C the monomer yielding is the lowest with highest by-product.
Oil Blends as Biolubricant: Screening of Effect Factors Influence to Basestock
Authors: Abdullah Rozaini , Kasim Farizul Hafiz , Zuki Siti Nur Amalieya Syaza Mohd , Shamsuddin Noor Hajarul Ashikin
Published: December 2013

The price fluctuation and negative environmental effect of mineral oil-based lubricant are the main factors which instigate the research on high-oleic vegetable oil as its possible replacement. In this study, the factors involved in blending process of waste cooking oil (WCO) and Jatropha curcas oil (JCO) as biolubricant basestock were investigated using 2-level factorial design. The molar ratio of WCO to the JCO (WCO:JCO), stirring speed and blending times were the three factors studied. The WCO:JCO, stirring speed and the blending time were found to be significant to the increased of oleic acid content in the basestock. The highest percentage of oleic acid achieved was 53.31 % at molar ratio of WCO:JCO at 20:80, 350 rpm and time at 30 minutes. Thus this study exposed the potential of new blending oil which are comparable with other vegetable and mineral oils as base stock for bio-lubricant in term of fatty acid compositions.
The Utilization of Aluminum Waste as Sand Replacement in Concrete
Authors: Rahim Nur Liza , Ibrahim Norlia Mohamad , Salehuddin Shamshinar , Che Amat Roshazita , Mohammed Syakirah Afiza , Hibadullah Cik Roziana
Published: December 2013

Development activities in construction sector have caused serious problems throughout the world as the natural resource depletion and produce large amounts of waste. In Malaysia, the main problem appeared when most of the waste was abandoned and not recycling. Such conditions can cause serious problem such as environmental pollution. This research utilizes aluminum waste as sand replacement in concrete. The use of these materials not only helps in the natural resources such as sand, aggregate, cement and other building. However, it also helps in reducing the manufacturing cost of the concrete. In addition, the reduction in the cost of waste disposal, saving manpower and protect the environment from the effects of pollution are the benefits derived from the use of waste materials. A study was conducted on the use of recyclable aluminum materials, as sand replacement material in concrete mix with replacement of 1%, 2% and 5%. Lab tests, including slump tests, compressive strength and water absorption were conducted in this study. As a result, samples containing 1% aluminum waste has better performance in terms of strength and containing 5% aluminum waste has good resistance to water absorption. Using aluminum waste in concrete is an interesting way in recycling waste thus can reduce waste disposal on sites and also can conserve the natural resources.
The Application of Brick Wall and Bamboo Reinforced Concrete Frame for Redevelopment of Traditional Houses in Pengotan Village
Authors: Sutarja I. Nyoman
Published: December 2013

Majority of people in Pengotan Village, Bangli Regency, Bali, Indonesia, do not have healthy and decent housing and neighborhoods. In 2008, the Central Statistics Board (BPS) announced that there were 134,804 poor households in Bali, including those in Bangli regency. Pengotan village is one of the nine villages in Bangli regency with the highest number of poor households (956,517). One of indicators that determine the poor household status is the poor quality of traditional houses inhabited, such as untilled floor (exposed soil) and low quality bamboo wall. Thus it is necessary to redevelop those houses into habitable houses that meet the standard of safety, health and comfort. This standard was set by the government through the Building Act No. 28/2002. Some aspects of the house redevelopment are the physical aspects of the house, redesign of the system of structure with the addition of brick walls and bamboo reinforced concrete frame, also replacement of roof and floor. This study aims to improve the physical safety and thermal comfort of the building.
Compressive Strength and Density of Cementless Unfired Lightweight Brick Utilizing Coal Ash from Coal-Fired Thermal Power Plant
Authors: Mohd Pahroraji Mohamad Ezad Hafez , Saman Hamidah Mohd , Rahmat Mohamad Nidzam , Kamaruddin Kartini , Rashid Ahmad Faiz Abdul
Published: December 2013

Millions tons of coal ash which constitute of fly ash and bottom ash were produced annually throughout the world. They were significant to be developed as masonry brick to substitute the existing widely used traditional material such as clay and sand brick which were produced from depleting and dwindling natural resources. In the present study, the coal ash from coal-fired thermal power plant was used as the main raw material for the fabrication of cementless unfired lightweight brick. The binder comprising of Hydrated Lime (HL)-activated Ground Granulated Blastfurnace Slag (GGBS) system at binding ratio 30:70, 50:50 and 70:30 were used to stabilize the coal ash in the fabrication process of the brick. Foam was used to lightweight the brick. The compressive strength and ambient density were evaluated on the brick. The results indicated that the brick incorporating HL-GGBS system achieved higher strength of 20.84N/mm2 at 28 days compare to the HL system with strength of 13.98N/mm2 at 28 days. However, as the quantity of foam increase at 0%, 25%, 50%, 75% and 100%, the strength and density for the brick decreased.
Investigation of Workpiece Positioning Methods for Machining Oil-Pocket on Hip-Implant Spherical Surface
Authors: Kartiko Nugroho , Yahya Azli , Nor Liyana Safura Hashim , Razak M. Daud , Haji Khamis Nor Hisham , Khalil Kamal , Rahim Muhammad Arif Abdul , Baharom Ameruddin
Published: December 2013

Oil pocket has been reported that it may improve tribology characteristic and thus prolong the lifespan of the joint. In order to implement it on spherical surface, appropriate positioning system is required. This paper reports the investigation of three axes workpiece positioning system in order to machine oil pocket (micro-pits) on hip implant. A conventional linear x-y-z axes configuration (Cartesian coordinate) and two configuration of spherical coordinate (swing-swing and swing-rotate configuration) are applied in simulation. All machined workpiece are investigated in pits distribution, shape, and machined angle. The inspection concludes that spherical method with swing-rotate configuration is the most suitable method for machining oil pocket on spherical surface.
Surface Morphology and Corrosion Behavior of Electrolytic Coatings in Different Aqueous Solutions
Authors: Salleh Siti Hawa Mohamed , Nazree Derman Mohd , Omar Mohd Zaidi , Malek Rohaya Abdul
Published: December 2013

SS440C steels show potential as highest mechanical properties compared to others martensitic stainless steels. As their properties can be altered by some particular heat treatments, this steel is suitable for a extensive ranges of applications such as bearings, gage blocks, races, valve parts and many other manufacturing important components. Unfortunately, bare SS440C substrates corrode too quickly under corrosive environments. Surface modifications that are able to reduce corrosion rates to suitable levels will allow SS440C to become a reality for much more applications [1-.
Warpage Analysis with Straight Drilled and Conformal Cooling Channels on Front Panel Housing by Using Taguchi Method
Authors: Shayfull Z. , Sharif S. , Zain Azlan Mohd , Saad R. Mohd , Fairuz M.A.
Published: December 2013

The challenging in injection molding process is to get the uniform thermal distribution on the molded parts during the cooling stage which is mainly depend on the design of the cooling channels in injection mold. Poor design of cooling channels will result a non-uniform thermal distribution which lead to a longer cycle time, differential shrinkage and warpage defects on the molded parts. In this study, the performance of conformal cooling channels compared to the straight drilled cooling channels in order to minimize the warpage on the front panel housing is evaluated. The simulation results from Autodesk Moldflow Insight (AMI) 2013 are analyzed by using Taguchi Method and Analysis of Variance (ANOVA). The analyses show that conformal cooling channels are able to improve the quality of the molded parts in term of warpage compared to the conventional straight drilled cooling channels and the results are beneficial for the molding industries which involving the precise parts.
Investigation on the Effect of TiO2 Nanofiller to the Structural and Conductivity Characteristics of Poly(vinylidene fluoride-co-hexafluoropropylene)/Poly(ethyl methacrylate) Based Polymer Electrolytes System
Authors: Rudhziah Siti , Mohamed N.S.
Published: December 2013

In this study, Poly (vinylidene fluoride-co-hexafluoropropylene)/Poly (ethyl methacrylate (PEMA) nanocomposite polymer electrolytes was prepared by solution casting technique. The effects of TiO2 nanofiller on the structural, thermal and conductivity characteristics were examined using x-ray diffraction, scanning electron microscopy, differential scanning calorimetry and impedance spectroscopy. The crystallinity and conductivity of the salted system are found to increase with the addition of TiO2. The system containing 5 wt % of TiO2 exhibited the highest room temperature conductivity of 1.32 × 10-3 S cm-1.
Effects of Trans-Polyoctylene Rubber in Polypropylene/Recycled Acrylonitrile Butadiene/Rice Husk Powder Composites
Authors: Ragunathan Santiagoo , Sam Sung Ting , Azlinda Abdul Ghani , Kamaruddin Hussin , Hanafi Ismail , Mustaqqim Abdul Rahim , Zuhayr Md Ghazaly
Published: December 2013

Composites of polypropylene/Acylonitrile butadiene rubber/Rice husk powder/ (PP/NBRr/RHP) with and without trans-polyoctylene rubber (TOR) were prepared, and the effects of trans-polyoctylene rubber were investigated. By using rice husk powder of 150300μm, five different compositions of PP/NBRr/RHP composites (i.e.100/0, 80/20, 70/30, 60/40 and 40/60 phr) were prepared in an internal mixer at 180 °C and 50 rpm rotor speed. The results indicate that the incorporation of TOR improved the tensile properties of PP/NBRr/RHPcomposites. Scanning electron microscopy of the fractured surfaces proved that TOR promoted good adhesion between the PP-NBRr matrices and RHP.Keywords: Polypropylene; Trans-polyoctylene rubber; Rice husk powder; Acrylonitrile Butadiene rubber; composite
Modification of Pin on Disc Test to Measure Railway Brake Block Friction Coefficient
Authors: Triono Agus , Ign Wiratmaja Puja , Brodjonegoro Satryo Soemantri
Published: December 2013

One of the eligibility brakes requirements that used by railway is the fulfillment of the prescribed limit of friction coefficien. Test performed to determination railway brake block friction coefficient using pin on disc test. This test convert brake force into normal force on load cell that could be replace by balance. But due to the existing gap between arm force and brake force, error could be happened. To minimalized this error, that gap had to be reduced. In this research, the gap was reduced from 4.5 cm to 1 cm. Data recording was modified from manual recording into automatic recording using LabView program. This modified was very usefull because recording data could be done easily.
Effect of Alkali Treatment on Crystalline Structure of Cellulose Fiber from Mendong (Fimbristylis globulosa) Straw
Authors: Suryanto Heru , Marsyahyo Eko , Irawan Yudy Surya , Soenoko Rudy
Published: December 2013

The research aim is to investigate the effect of alkali treatment on the crystalline structure of Mendong fiber. The experiment was conducted by immerse fibers in 100 ml NaOH solution by a concentration of 2.5%, 5%, 7.5%, and 10% for 2 hours at the room temperature. The specimens were characterized by X-ray diffraction method. The morphology of fiber treated by alkali was observed by Scanning Electron Microscope. The result shows that the crystalline structure of cellulose in Mendong fiber was changed in alkali treatment. It was found that both the degree of crystallinity and crystalline index of Mendong fiber was increased until alkali treatment concentration of 7.5%.
Tensile and Morphology Properties of Polylactic Acid/Treated Typha latifolia Composites
Authors: Ibrahim Muthmirah , Jalil Jalilah Abd , Mahamud Syarifah Nuraqmar Syed , Yusrina Mat Daud , Husseinsyah Salmah , Rafi’ Yahya Muhammad
Published: December 2013

This paper is focused to investigate the effect of treated natural fiber (typha latifolia) content on tensile and morphology properties of polylactic acid (PLA)/treated typha latifolia (T-TyLa) composites. The composite was compounded using heated two roll mill and the composite samples were prepared through compression molding. Tensile test and scanning electron microscopy (SEM) analysis were carried out to study the properties of PLA/T-TyLa composites. The results showed that the tensile strength of PLA/T-TyLa composites was decreased for about 43% with initial addition of T-TyLa content. The tensile modulus of the composites was increased (23%-91%) with increasing of fiber content. However, increased in fiber content reduced the elongation at break for about 53%-67% of PLA/T-TyLa composites. The optimum increment was obtained at 30 wt% of fiber content. SEM results showed that fiber dispersion was better for PLA/T-TyLa composites at lower fiber content.
Effect of Organic Space Holder in Fabrication of Cloced-Cell Aluminium Foam
Authors: Idris Maizlinda Izwana , Ehsan I.I.Md. , Mohamed S.H.
Published: December 2013

In this work, the closed-cell aluminium foams were fabricated via powder metallurgy route with organic space holder which also known as carbamide (urea). Carbamide was added with aluminium powder at different compositions from 50wt% to 70wt%. Then the influences of sintering temperatures were also investigated at 500°C, 550°C and 600°C. Physical and mechanical tests were conducted on the fabricated closed cell aluminium foam samples. The result showed that the porosity inversely proportional with density, that means the porosity decreases as the density of the foam increased. Also, it was revealed that the highest compressive strength was obtained at sintering temperature of 550°C. However, the compressive strength of the closed-cell aluminium foam decreased at the sintering temperature of 600°C. This is due to the occurrence of oxidation problem. It can be concluded that carbamide can be proposed as one of the organic space holder material in the fabrication of closedcell aluminium foam. Then, the experimental parameters such as sintering temperature, type of space holder and composition gave great influence to the mechanical and physical properties of the fabricated closed-cell aluminium foam.
The Effects of Dynamic Vulcanization in Virgin Polyethylene (vPE)/Recycled Polyethylene (rPE)/Ethylene Propylene Diene Terpolymer (EPDM) Blends: Tensile Properties and Morphology
Authors: Ismail Hanafi , Noimam N.Z. , Wei Woon Hon , Nik Yahya N.Z.
Published: December 2013

The effects of dynamic vulcanisation in vPE/rPE/EPDM blends were studied. The discarded polyethylene used in the study was obtained from local cable manufacturers. The effects of different sulfur loading on the tensile properties and morphology of the thermoplastics elastomer blends were examined. Results show that the tensile properties (except EB) increased as increasing in sulfur loading. Scanning electron microscopy indicates that a uniform distribution of vulcanised EPDM in vPE/rPE/EPDM blends.
The Influence of CB, Silica and CaCO3 on Tensile and Morphological Properties of vPE/rPE/EPDM Blends
Authors: Ismail Hanafi , Noimam N.Z. , Wei Woon Hon , Nasir Muhammad Ridhwan Jamalul
Published: December 2013

The virgin polyethylene (vPE) and recycled polyethylene (rPE) was melt blended with ethylene propylene diene terpolymer (EPDM) in different ratio by using a Haake Rheomix at 180°C and 50 rpm were prepared. The characterization such as tensile properties and morphology were examined. Results indicated that, the tensile strength and youngs modulus of vPE/rPE/EPDM with CB show the highest value compared to silica and CaCO3 except for elongation at break. The scanning electron microscopy (SEM) studies proved that, better dispersion and less agglomeration of CB and silica filled particles as compared to the CaCO3.
Strain Distribution on Reinforcement of Concrete Beams Reinforced with Glass Fiber Reinforced Polymer (GFRP) Bars
Authors: Noor Azlina Abdul Hamid , Rendy Thamrin , Azmi Ibrahim , Hamid Hanizah Abdul
Published: December 2013

This paper presents a part of the results from an experimental study of strain distribution on reinforcement of concrete beams reinforced with glass fiber-reinforced polymer (GFRP) bars. Under static loading conditions, eight concrete beams reinforced with GFRP bars were tested and as comparison eight beams with steel reinforcement were also tested. All of the beams were prepared with varying ratios of longitudinal reinforcement bars and stirrups. The effect of shear span-effective depth ratio on strain distribution of longitudinal reinforcement was also observed. Furthermore, the behavior of strain on stirrups due to different materials of longitudinal reinforcement was also discussed in this report. The test results show that the ratio of longitudinal reinforcement significantly influence the strain distributions on reinforcement where the beams with higher ratio exhibit higher strain. Moreover, it was also obtained that the different types of longitudinal reinforcement considerably influences the strain behavior on stirrups as higher strain was observed in beams reinforced with GFRP bars.
The Effect of Methylene Diphenyl Diisocyanate on the Nonisothermal Properties of Polylactic Acid/Elaeis guineensis Fibres Biocomposites
Authors: Ahmad Subri Luqman Hakim , Alauddin Sakinah Mohd , Rosman Senawi
Published: December 2013

Biocomposites demands are significantly rising due to environmental regulations and concerns. However, incompatibility between the fibre and matrix is a major setback that diminishes the biocompostie properties. Therefore in this work, methylene diphenyl diisocynate (MDI) compatibilizers were used together with fibre surface treatment in order to increase compatibility between polylactic acid (PLA) and Elaeis Guineensis Fibres (EGF) biocomposite. Nonisothermal properties were investigated and it was found that, MDI increased compatibility of the PLA and EGF which led to the restriction of chain movements in the biocomposite. This restriction in chain mobility caused an increase the glass transition temperature and crystallization temperature and also reduced the degree of crystallinity.
High Sensitivity Humidity Sensor Based on ZnSnO3 Composite Nanocube
Authors: Md Sin N.D. , Musa M.Z. , Mamat M.H. , Ahmad S. , Aziz A. Abdul , Rusop Mohamad
Published: December 2013

The performance of nanocomposites semiconducting material used as a sensor is very much depending upon physical and chemical properties of the material. In this paper we address sensitivity of ZnSnO3thin film deposited by hydrothermal deposition in terms of its behavior towards humidity variations. The electrical, optical and structural properties of ZnSnO3thin film deposit at different volume of solvent (50 ml and 70 ml) grown by novel deposition of ZnSnO3hydrothermal with low temperature 95°C are also reviewed. The sensor performance of ZnSnO3thin film prepared at 50 ml volume show high sensitivity towards humidity. Using FESEM it was noted that the nanocube of ZnSnO3thin films growth on ZnO template with the size of nanocube is 100 to 140nm by varying the volume of the solvent.
Preparation of Polyethersulfone Ultrafiltration Membrane Surface Coated with TiO2 Nanoparticles and Irradiated under UV Light
Authors: Mohamad Siti Hawa , Idris M.I. , Abdullah Hasan Zuhudi
Published: December 2013

This paper focuses on performance of polyethersulfone (PES) ultrafiltration membrane coated with titanium dioxide (TiO2) nanoparticles and irradiated with UV light. The flat sheet membrane was prepared via phase inversion method, with two types of membrane; TiO2 coated PES membrane and UV irradiated TiO2 coated PES membrane. TiO2 suspension with concentration of 0.01, 0.03 and 0.05 wt.% were prepared and coated on the PES surface via dip coating. Membrane was immersed in all suspension for 15 minutes and 30 minutes. Then, prepared coated membranes were irradiated by 184 Watts UV lamp for 15 minutes. The performance of membranes was examined by permeation of humic acid. The morphology of membranes was analyzed by scanning electron microscopy (SEM). It was revealed that the pure water flux and humic acid permeation of UV irradiated TiO2 coated membrane was higher than TiO2 coated membrane. It can be concluded that TiO2 coated with 0.03 wt.% of suspension, 30 minutes and 15 minutes UV irradiation with 184 Watt light were determined as the optimum conditions for preparation ultrafiltration PES membrane.
Effect of Volume Plasticizers on the Thermal Performance of Tacca leontopetaloides Starch Biopolymer
Authors: Mohd Makhtar Nurul Shuhada , Mohd Amin Ainatul Mardhiah , Ghafar Nur Farzana Abdul , Aziz Nur Shahidah Ab , Muhd Rodhi Miradatul Najwa , Mohibah Musa , Hamid Ku Halim Ku
Published: December 2013

The effect of 10, 30 and 50 % volume of Olein oil, Glycerol and Crude Palm Oil (CPO) as plasticizer on the thermal performance of biopolymer has been investigated in this paper. The biopolymer was developed from a new source of starch,Tacca leontopetaloides, and natural rubber by using two roll-mill. Changes in functional groups and thermal performance of formulated bio-Thermoplastic elastomer (TPE) were analyzed by Fourier Transform Infrared (FTIR) and Thermogravimetric Analyzer (TGA). Increased volume of Olein oil and glycerol resulted to increasing strength of hydrogen bonding in the intermolecular TPEs, therefore it has high thermal resistant towards high temperature. Conversely, increased volume of CPO decreased the strength of hydrogen bonding in structural starch and CPO therefore TPE with CPO shows high degradability which possess up to 100 % weight reduction at 500 0C.
Filling Missing Data Using Interpolation Methods: Study on the Effect of Fitting Distribution
Authors: Noor M.N. , Yahaya A.S. , Ramli N.A. , Al Bakri Abdullah Mohd Mustafa
Published: December 2013

The presence of missing values in statistical survey data is an important issue to deal with. These data usually contained missing values due to many factors such as machine failures, changes in the siting monitors, routine maintenance and human error. Incomplete data set usually cause bias due to differences between observed and unobserved data. Therefore, it is important to ensure that the data analyzed are of high quality. A straightforward approach to deal with this problem is to ignore the missing data and to discard those incomplete cases from the data set. This approach is generally not valid for time-series prediction, in which the value of a system typically depends on the historical time data of the system. One approach that commonly used for the treatment of this missing item is adoption of imputation technique. This paper discusses three interpolation methods that are linear, quadratic and cubic. A total of 8577 observations of PM10 data for a year were used to compare between the three methods when fitting the Gamma distribution. The goodness-of-fit were obtained using three performance indicators that are mean absolute error (MAE), root mean squared error (RMSE) and coefficient of determination (R2). The results shows that the linear interpolation method provides a very good fit to the data.
Design and Development of Tracking System for Mines Detector Robot
Authors: Firdaus Ahamad Zaidi Ahmad , Liang Ng Shao , Hafis Mohd Bin Sulaiman , Ridzuan Mohd Jamir Mohd , Zaidi Nur Hidayah Ahmad
Published: December 2013

This paper presents the design and development of tracking system for the mines detector robot. The scope for the tracking system covers two important tasks: 1. Design of optimum tracking path to cover maximum scanning area of an enclosed field, and 2. Obstacles avoidance system to be able avoid the various types of obstacles during the scanning process. The tracking algorithms were designed and simulated using Webots simulation software. Upon successful simulation where all design objectives have been achieved, the algorithms were programmed in microcontroller to implement the tracking system on the mines detector robot. Experimental test rig for the robot was a flat surface, enclosed 3m x 3m area where several obstacles of different sizes and shapes were randomly placed. Several metal samples representing the metal detonator of minefield were also placed to test the sensing system of the robot. Infra-red (IR) sensors were used for the system to detect the obstacles and also to detect the end-path boundary of a routine scanning cycle. While simulation test results have shown achieved design objectives, experimental results shown 90% achievement and limitation on evading big size of circle-type obstacle.
Numerical Stress Analysis of Epoxy Adhesively Bonded Dissimilar Joint
Authors: Athirah Nur , Abdullah A.R. , Afendi M. , Majid M.S. Abdul , Daud Ruslizam , Idrus Haftirman
Published: December 2013

A two-dimensional adhesively bonded dissimilar single lap joint model was analyzed under tension. An explicit closed-form solution was formulated by using MATLAB tool for analysis of shear and peel stresses distribution along the bondline under effect of variation of overlap length, adherend thickness ratio and adherend Youngs modulus ratio. The solution was formulated based on analysis of Bo Zhao et al. [2]. The bending moment at the edge joint of the Bo Zhaos solution was replaced by the bending moment at the edge joint that have been proposed by X. Zhao et al. [5] to compare the accuracy of solutions. The least stress intensities in dissimilar joint could be achieved with a suitable ratio of thickness and Youngs modulus of adherends.
Estimation of Bioethanol Production from Jatropha curcas Using Neural Network
Authors: Abd. Rahman Norliza , Kofli N.T. , Yaakob Zahira , Gauri S.
Published: December 2013

Fossil fuel is one of the main energy sources for almost all country in the world. However, it is non-renewable energy source, not environmental friendly and the limited supply of the fossil fuel encouraged the scientist to discover other alternative way of new renewable energy supply. New alternative source should be considered for prolonged lifetime. Thus, non-conventional energy sources should be placed in the prior consideration, for instant bioethanol. Jatropha curcas seed is a toxic substance; however, it has a very high oil content which is approximately 3545%. After the extraction of oil from the seed, Jatropha seed cake is formed. In the pressed seed cake, it is found that it contains cellulose and glucose that can be used as substrate in bioethanol production. The production of bioethanol can be estimated by neural network using data from previous research. A programme using MATLAB 7.8 was used to develop the neural network. The software consists of Neural Network Toolbox which functions to train the input data and estimate the production of glucose and bioethanol as output data. An input layer represents the criteria of the production properties of glucose and bioethanol concentration. The hidden layer determines either the input data can be proceed to further production of glucose and bioethanol, whereas the output layer gives the estimation values of glucose and bioethanol production. Back propagation algorithm with TANSIG transfer function was used to accomplish the estimation of production of bioethanol. The error value given by the network was 0.0390. Thus, training sessions were considered successful. Therefore, the users could determine and estimate the production of glucose and bioethanol concentration in just a short period of time.
Thermophysical Properties of Ionic Liquid with Thiocyanate and Dicynamide Anions
Authors: Gonfa G. , Bustam M.A. , Murugesan T. , Man Z. , Abdul Mutalib M.I.
Published: December 2013

In this work, density and viscosity of ionic liquids with dicynamide and thiocyanate anion were obtained. The thermal expansion coefficient values were obtained from the experimental density values. The density and viscosity of the ionic liquids depends on the nature of the cations. The density of the ionic liquids increases in the order of [BMIM]+ < [AMI+ < [BzMI+ < [HEMI+ for dicynamide anion. Both for thiocyanate and dicynamide anions the viscosity values increase in the order of [BMI+ < [AMI+ < [BMI+ < [HEMI+. Moreover, viscosity values of ionic liquids with dicynamide anions are less than their corresponding thiocyanate anion.
Two-Step Sintering of Fine Barium Cerate-Zirconate Ceramics Electrolyte
Authors: Salmie Suhana Che Abdullah , Rohaya Abdullah , Nafisah Osman
Published: December 2013

Two-step sintering (TSS) was applied on the BaCe0.54Zr0.36Y0.1O2.95powder and the effect of the second step temperature (T2) during sintering process on the grain growth, density and hardness is reported. Normal sintering with holding temperature of 1500 °C and four different TSS profiles with four various T2 (1150 °C, 1250 °C, 1350 °C, 1450 °C) were conducted. From the results, sample sintered via TSS at T2 of 1450 °C shows the highest density compared to other samples including sample sintered via normal sintering at temperature 1500 °C. The grain size of the sample sintered at T2 of 1450 °C also smaller than the sample sintered via normal sintering. Result from hardness test proves the hardness also increase when the density increase.
The Effect of Inoculation on Properties of Modified Ductile Ni-Resist Alloy
Authors: Rashidi Mohd M. , Idris Mohd Hasbullah , Shayfull Z.
Published: December 2013

In this study, ductile Ni-resist alloy with a minimum 18 wt. % nickel composition was modified. Up to 12 wt. % manganese was added together with 10 wt. % nickel before undergoing the inoculation process at various percentages to investigate the effects of the alloying elements on both its microstructure and mechanical properties.. The results showed that increasing inoculation did reduce carbide formation and further led to improved tensile value and decreased hardness value. Moreover, inoculation led to a uniform distribution of free graphite. The experimental results show the inoculation process refined the modified alloyed iron microstructure and improved its mechanical properties.
The Response of Secondary Genes to Lipopolysaccharides in Macrophages Depends on Histone Deacetylase and Phosphorylation of C/EBPβ
Authors: Serrat Neus , Sebastian Carlos , Pereira-Lopes Selma , Valverde-Estrella Lorena , Lloberas Jorge , Celada Antonio
Published: December 2013

LPS induces the expression of NO synthase 2 (nos2) in macrophages. The expression of this molecule is one of the hallmarks of classical activation. In this paper, we describe that trichostatin A (TSA), which inhibits deacetylase activity, blocks LPS-dependent nos2 expression. TSA specifically inhibits LPS-dependent genes of secondary response, which require new protein synthesis for their induction but not those belonging to the primary response, which do not depend on this process. Deacetylase activity acts at the transcriptional level because RNA polymerase II was not bound after LPS stimulus when we added TSA. A link between the global acetylation caused by HDAC inhibitor and gene promoter recruitment of CDK8 was found. This Mediator complex subunit associates with Med 12, Med13, and cyclin C to form a submodule that is a transcriptional negative regulator. We also found that TSA reduces C/EBPβ phosphorylation without affecting its binding to DNA. Taken together, these results shed light on the molecular mechanisms involved in the transcriptional regulation of LPS-treated macrophages and on how TSA targets critical LPS-induced genes, such as nos2 and tnf-α, in inflammatory macrophage response.
Polymorphisms in the CD1d Promoter That Regulate CD1d Gene Expression Are Associated with Impaired NKT Cell Development
Authors: Borg Zachary D. , Benoit Patrick J. , Lilley Graham W. J. , Aktan Idil , Chant Alan , DeVault Victoria L. , Rincon Mercedes , Boyson Jonathan E.
Published: December 2013

CD1d-restricted NKT cells comprise an innate-like T cell population that exerts significant influence over early events in the developing immune response. The frequency of NKT cells is highly variable in humans and in mice, but the basis for this variability remains unclear. In this study, we report a striking deficiency of type I NKT cells in the wild-derived inbred strains PWD/PhJ, SPRET/EiJ, and CAST/EiJ. Investigation of the underlying basis for the lack of type I NKT cells revealed that one strain, PWD/PhJ, exhibited a significant impairment in thymocyte and splenocyte CD1d gene and protein expression. Accordingly, both thymocytes and bone marrow–derived dendritic cells from PWD mice exhibited a significant impairment in the ability to present α-galactosylceramide to NKT cells. The impaired PWD CD1d gene expression was due to impaired CD1d promoter activity. Fine-mapping of the promoter activity revealed that two single nucleotide substitutions at positions −331 and −164 in the proximal promoter were each sufficient to account for the diminished PWD CD1d promoter activity. Examination of the strain distribution pattern of these polymorphisms revealed that, of 19 strains analyzed, only PWD and PWK mice possessed both CD1d promoter polymorphisms. A subsequent examination of the PWK strain revealed that it also exhibited impaired thymocyte CD1d expression and very low numbers of NKT cells. Taken together, these results provide new insight into the control of CD1d gene expression, and they have implications for the evolution of CD1d and type I NKT cells.
A Single Amino Acid Substitution in the Hemagglutinin of H3N2 Subtype Influenza A Viruses Is Associated with Resistance to the Long Pentraxin PTX3 and Enhanced Virulence in Mice
Authors: Job Emma R. , Bottazzi Barbara , Short Kirsty R. , Deng Yi-Mo , Mantovani Alberto , Brooks Andrew G. , Reading Patrick C.
Published: December 2013

The long pentraxin, pentraxin 3 (PTX3), can play beneficial or detrimental roles during infection and disease by modulating various aspects of the immune system. There is growing evidence to suggest that PTX3 can mediate antiviral activity in vitro and in vivo. Previous studies demonstrated that PTX3 and the short pentraxin serum amyloid P express sialic acids that are recognized by the hemagglutinin (HA) glycoprotein of certain influenza A viruses (IAV), resulting in virus neutralization and anti-IAV activity. In this study, we demonstrate that specificity of both HA and the viral neuraminidase for particular sialic acid linkages determines the susceptibility of H1N1, H3N2, and H7N9 strains to the antiviral activities of PTX3 and serum amyloid P. Selection of H3N2 virus mutants resistant to PTX3 allowed for identification of amino acid residues in the vicinity of the receptor-binding pocket of HA that are critical determinants of sensitivity to PTX3; this was supported by sequence analysis of a range of H3N2 strains that were sensitive or resistant to PTX3. In a mouse model of infection, the enhanced virulence of PTX3-resistant mutants was associated with increased virus replication and elevated levels of proinflammatory cytokines in the airways, leading to pulmonary inflammation and lung injury. Together, these studies identify determinants in the viral HA that can be associated with sensitivity to the antiviral activities of PTX3 and highlight its importance in the control of IAV infection.
Expansion of CMV-Mediated NKG2C+ NK Cells Associates with the Development of Specific De Novo Malignancies in Liver-Transplanted Patients
Authors: Achour Abla , Baychelier Florence , Besson Caroline , Arnoux Armelle , Marty Michel , Hannoun Laurent , Samuel Didier , Debré Patrice , Vieillard Vincent ,   the K-GREF Study Group
Published: December 2013

Solid cancers are a major adverse outcome of orthotopic liver transplantation (OLT). Although the use of chronic immunosuppression is known to play a role in T cell impairment, recent insights into the specificities of NK cells led us to reassess the potential modulation of this innate immune cell compartment after transplantation. Our extensive phenotypic and functional study reveals that the development of specific de novo noncutaneous tumors post-OLT is linked to unusual NK cell subsets with maturation defects and to uncommon cytokine production associated with the development of specific cancers. Remarkably, in CMV+ patients, the development de novo head/neck or colorectal tumors is linked to an aberrant expansion of NK cells expressing NKG2C and a high level of intracellular TNF-α, which impact on their polyfunctional capacities. In contrast, NK cells from patients diagnosed with genitourinary tumors possessed a standard immature signature, including high expression of NKG2A and a robust production of IFN-γ. Taken together, our results suggest that under an immunosuppressive environment, the interplay between the modulation of NK repertoire and CMV status may greatly hamper the spectrum of immune surveillance and thus favor outgrowth and the development of specific de novo tumors after OLT.
A Presacral Solitary Fibrous Tumor with Extramedullary Hematopoiesis: Radiologic and Pathologic Findings
Authors: Savastano Sergio , d'Amore Emanuele S.G. , Beghetto Mario , Borgo Davide Dal , Franceschetti Ilaria , Capalbo Mirella
Published: December 2013

Solitary fibrous tumors (SFT) are rare, ubiquitous neoplasms of mesenchymal origin, with distinctive histopathological and immunohistochemical features. We herein report an unusual case of a presacral SFT diagnosed in an asymptomatic 40-year-old woman preoperatively investigated with computed tomography and magnetic resonance imaging. Post-operative pathology examination showed a SFT containing foci of extramedullary hematopoiesis. Revision of preoperative imaging did not evidenced any findings suggesting this unusual association. The patient was free from local recurrence and metastases one year after operation. Differential radiological and histological diagnoses of solid presacral masses is briefly discussed.
Lipoprotein Glomerulopathy Associated with a Mutation in Apolipoprotein E
Authors: Magistroni Riccardo , Bertolotti Marco , Furci Luciana , Fano Rita Adriana , Leonelli Marco , Pisciotta Livia , Pellegrini Elisa , Calabresi Laura , Bertolini Stefano , Calandra Sebastiano
Published: December 2013

Lipoprotein glomerulopathy is a pathological condition characterized by lipid accumulation in the glomerular capillaries that has been associated with the presence of rare mutants of apolipoprotein E (ApoE). We describe a 51-year-old Italian patient presenting Type III hyperlipidemia and proteinuria in whom renal biopsy showed capillary ectasia and intraluminal lipid deposits, suggesting the diagnosis of lipoprotein glomerulopathy. The patient, who had elevated plasma ApoE level, was found to be heterozygous for a mutation in ApoE (Arg150Cys), designated apoEMODENA. This mutation induces the formation of ApoE dimers that are detectable under non-reducing conditions. Treatment with hypolipidemic drugs did not result in a complete remission of the proteinuria and was accompanied by a slow but progressive worsening of renal function with the persistence of intracapillary lipid thrombi. The introduction of low-density lipoprotein aphaeresis combined with a more aggressive lipid lowering and antihypertensive therapy resulted in the remission of proteinuria and a substantial improvement of renal function. Switching from low-density lipoprotein aphaeresis to plasma filtration did not result in an equivalent control of renal damage. The patient died of intracranial hemorrhage during an acute episode of malignant hypertension.
Perron-Frobenius operators and the Klein-Gordon equation
Authors: Canto-Martín Francisco , Hedenmalm Haakan , Montes-Rodríguez Alfonso
Published: December 2013

For a smooth curve

\Gamma

and a set

\Lambda

in the plane

\mathbb R^2

, let

\mathrm{AC}(\Gamma;\Lambda)

be the space of finite Borel measures in the plane supported on

\Gamma

, absolutely continuous with respect to the arc length and whose Fourier transform vanishes on

\Lambda

. Following [12], we say that

(\Gamma,\Lambda)

is a Heisenberg uniqueness pair if

\mathrm{AC}(\Gamma;\Lambda)=\{0\}

. In the context of a hyperbola

\Gamma

, the study of Heisenberg uniqueness pairs is the same as looking for uniqueness sets

\Lambda

of a collection of solutions to the Klein–Gordon equation. In this work, we mainly address the issue of finding the dimension of

\mathrm{AC}(\Gamma;\Lambda)

when it is non-zero. We will fix the curve

\Gamma

to be the hyperbola

x_1x_2=1

, and the set

\Lambda= \Lambda_{\alpha,\beta}

to be the lattice-cross

\Lambda_{\alpha,\beta}=\left(\alpha \mathbb Z\times\{0\}\right)\cup \left(\{0\}\times\beta \mathbb Z\right),

where

\alpha,\beta

are positive reals. We will also consider

\Gamma_+

, the branch of

x_1x_2=1

where

x_1>0

. In [12], it is shown that

\mathrm{AC}(\Gamma;\Lambda_{\alpha,\beta})=\{0\}

if and only if

\alpha\beta\le1

. Here, we show that for

\alpha\beta>1

, we get a rather drastic “phase transition”:

\mathrm{AC}(\Gamma;\Lambda_{\alpha,\beta})

is infinite-dimensional whenever

\alpha\beta>1

. It is shown in [13] that

\mathrm{AC}(\Gamma_+;\Lambda_{\alpha,\beta})=\{0\}

if and only if

\alpha\beta<4

. Moreover, at the edge

\alpha\beta=4

, the behavior is more exotic: the space

\mathrm{AC}(\Gamma_+;\Lambda_{\alpha,\beta})

is one-dimensional. Here, we show that the dimension of

\mathrm{AC}(\Gamma_+;\Lambda_{\alpha,\beta})

is infinite whenever

\alpha\beta>4

. Dynamical systems, and more specifically Perron–Frobenius operators, will play a prominent role in the presentation.
Null controllability of Grushin-type operators in dimension two
Authors: Beauchard Karine , Cannarsa Piermarco , Guglielmi Roberto
Published: December 2013

We study the null controllability of the parabolic equation associated with the Grushin-type operator

A=\partial_x^2+|x|^{2\gamma}\partial_y^2\,, (\gamma>0),

in the rectangle

\Omega=(-1,1)\times(0,1)

, under an additive control supported in an open subset

\omega

of

\Omega

. We prove that the equation is null controllable in any positive time for

\gamma<1

and that there is no time for which it is null controllable for

\gamma>1

. In the transition regime

\gamma=1

and when

\omega

is a strip

\omega=(a,b)\times(0,1)\,, (0<a,b\le1)

, a positive minimal time is required for null controllability. Our approach is based on the fact that, thanks to the particular geometric configuration of

\Omega

, null controllability is closely linked to the one-dimensional observability of the Fourier components of the solution of the adjoint system, uniformly with respect to the Fourier frequency.
Homology computations for complex braid groups
Authors: Callegaro Filippo , Marin Ivan
Published: December 2013

Complex braid groups are the natural generalizations of braid groups associated to arbitrary (finite) complex reflection groups. We investigate several methods for computing the homology of these groups. In particular, we get the Poincaré polynomial with coefficients in a finite field for one large series of such groups, and compute the second integral cohomology group for all of them. As a consequence we get non-isomorphism results for these groups.