bluuebunny/crossref_metadata_2025 huggingface dataset:
La ville, un « territoire du risque » privilégié ? Quand la représentation est un facteur de vulnérabilité (City, a privileged « territory of hazard » ? When representation is a factor of vulnerability)
Authors: Reghezza-Zitt Magali
Published: June 2014

Perceptions linked with certain territories are elements of vulnerability. A city — and now, a global city — can be thought of as the spatial inscription of the need for security. The representation of cities as safe havens results from a long historical process. This process created in the same time the idea that cities are places of hazards. The ideal of security increases the vulnerability of these places.
Peuples et préjugés chez Dion de Pruse et Lucien de Samosate
Authors: Gangloff Anne
Published: June 2014

During classical era, the notion of Greek identity was built relatively to barbarian identities. What did it become during the first two centuries of Roman Empire, according to sophist philosopher Dion of Prusa and writer Lucian of Samosata, two representatives of imperial hellenism who weren't Greeks from main Greece, who widely travelled and experienced disenchantements with their relations to Roman power ? This study attempts to compare their acceptance and use of traditional Greek prejudices and models, as well as their thoughts about the concepts of alterity and barbarity. Dion and Lucian, in different ways, spread a kind of hellenism built relatively to classical Grecism and his prejudices.
Parole, silence et mort : le complet des prétendants dans le roman de Chariton
Authors: Kasprzyk Dimitri
Published: June 2014

This paper studies the role of speaking in the episode of the suitors' plot at the beginning of Chariton's novel Chaereas and Callirhoe. Indeed the issue of the plot depends on the ability of characters to speak : when the suitors monopolize and manipulate the logos, the heroes cannot defend themselves as they did by their first attempt. On the contrary, they are reunited at the end of the novel as soon as they speak again to each other at Arados. From a dramatic point of view, a great importance is given to speech by a novelist who is a rhetor too.
Les Problemata hippocratiques : un exemple original de catéchisme et commentaire dans la tradition médicale et religieuse
Authors: Guardasole Alessia
Published: June 2014

Les Problèmes hippocratiques consistent en un corpus anonyme de 130 questions et réponses, qui - dans une parfaite Ringkomposition - s'ouvre et se termine avec des questions issues de la tradition des Aphorismes d'Hippocrate. Comme Jacques Jouanna l'a déjà montré, ce corpus se caractérise par l'originalité des explications du texte des Aphorismes dans la tradition des commentaires galénique et byzantins au traité d'Hippocrate. L'intérêt de ces problèmes réside également dans le fait qu'à côté d'Hippocrate les autres textes de référence, à partir desquels l'auteur se livre à des réflexions médicales et physiques, rentrent à la fois dans le domaine de la littérature dite « des questions et réponses » (notamment pseudo-Alexandre d'Aphrodise, mais aussi Aristote, Cassius Iatrosophiste et Théophylacte Simokattès), de la tradition néoplatonicienne des commentaires à Aristote (Olympiodore), des Écritures (Ecclésiaste, Psaumes) et des Pères de l'Église (Jean Chrysostome). Par l'étude des sources, nous essayons de dévoiler les mécanismes de constitution de ce catéchisme tout à fait original d'époque byzantine.
L'activisme numérique au regard du consumérisme politique : Pirates et Tea Partiers sous la loupe
Authors: Baygert Nicolas
Published: June 2014

Les potentialités liées au décloisonnement numérique de la parole politique facilitent le processus de co-construction d’une offre partisane d’un nouveau type. Le consumérisme politique vise à décrire ce phénomène. Il s’agit, à travers les exemples récents du Tea Party et du Parti pirate, d’appréhender l’émergence d’un activisme autogéré, voire peer-to-peer. Alors que ces deux mouvements innovent de par leur dynamique décisionnelle, il paraît néanmoins utile d’examiner leur impact réel sur le jeu démocratique, par-delà leur nature proprement contestataire, ainsi que d’évaluer leur capacité à refonder les modalités de la participation.
Las relaciones internacionales del régimen de Franco: una reflexión
Authors: Delgado Gómez-Escalonilla Lorenzo
Published: June 2014

La producción historiográfica sobre las relaciones internacionales del régimen de Franco ha aumentado considerablemente en los últimos años. Este artículo analiza algunas de las características fundamentales de los estudios dedicados al tema: predominio de la historia política en clave internacional, endeble soporte conceptual y metodológico, y ausencia de debates que permitan una valoración rigurosa de los logros alcanzados y los desafíos pendientes. Tras ello, se plantean una serie de elementos de reflexión —claves y protagonistas de esas relaciones internacionales, coordenadas interiores y exteriores—, para concluir con un esbozo de posibles perspectivas de la investigación.
La transición democrática en el periodismo político de Francisco Umbral
Authors: Ardavín Carlos X.
Published: June 2014

El presente artículo representa un estudio del articulismo político de Francisco Umbral referido al tema de la transición democrática, y asume como tesis que el citado articulismo articula una visión irónica y escéptica de dicho proceso. Para ello, se analizan una serie de recopilaciones periodísticas que demuestran el alto grado de visión política de Umbral y su sostenida voluntad de reflexión en torno al hecho más importante de la reciente historia política de España.
Personalidad, ciencia y contexto histórico en un sabio ilustrado: Humboldt y el Virreinato de la Nueva Granada (1801-1829)
Authors: Navas Sierra J. Alberto
Published: June 2014

Sin que hubiera sido el resultado de un bien meditado proyecto expedicionario, el científico prusiano, barón Alejandro de Humboldt, terminó recorriendo de Norte a Sur el antiguo Virreinato de la Nueva Granada. Su visita, que se inicio en marzo de 1801 y se prolongó hasta agosto de 1802, resultó extraordinariamente rica en experiencias y resultados científicos; los que han sido largamente resaltados por una amplia bibliografía al respecto. Sin embargo, no han sido suficientemente estudiados los aspectos histórico-contextuales y biográficos que antecedieron y singularizaron la estadía de Humboldt en las actuales Repúblicas de Colombia y Ecuador.
Trends in the Distribution and Abundance of Yellowstone Cutthroat Trout and Nonnative Trout in Idaho
Authors: Meyer Kevin A. , Larson Erin I. , Sullivan Christopher L. , High Brett
Published: June 2014

The distribution and abundance of Yellowstone cutthroat trout Oncorhynchus clarkii bouvieri across their native range is relatively well-known, but evaluations of trends in distribution and abundance over time are lacking. In 2010–2011, we resurveyed 74 stream reaches in the upper Snake River basin of Idaho that were sampled in the 1980s and again in 1999–2000 to evaluate changes in the distribution and abundance of Yellowstone cutthroat trout and nonnative trout over time. Yellowstone cutthroat trout occupied all 74 reaches in the 1980s, 70 reaches in 1999–2000, and 69 reaches in 2010–2011. In comparison, rainbow trout O. mykiss and rainbow × cutthroat hybrid occupancy increased from 23 reaches in the 1980s to 36 reaches in 1999–2000, and then declined back to 23 reaches in 2010–2011. The proportion of reaches occupied by brown trout Salmo trutta and brook trout Salvelinus fontinalis was largely unchanged across time periods. Yellowstone cutthroat trout abundance declined from a mean of 40.0 fish/100 linear meters of stream in the 1980s to 32.8 fish/100 m in 2010–2011. In contrast, estimates of abundance increased over time for all species of nonnative trout. Population growth rate (λ) was therefore below replacement for Yellowstone cutthroat trout (mean  =  0.98) and above replacement for rainbow trout (1.07), brown trout (1.08), and brook trout (1.04), but 90% confidence intervals overlapped unity for all species. However, λ differed statistically from 1.00 within some individual drainages for each species. More pronounced drought conditions in any given year resulted in lower Yellowstone cutthroat trout abundance 1 y later. Our results suggest that over a span of up to 32 y, the distribution and abundance of Yellowstone cutthroat trout in the upper Snake River basin of Idaho appears to be relatively stable, and nonnative trout do not currently appear to be expanding across the basin.
Negotiating Boundaries between Control and Dissent
Authors: Bowe Brian J. , Blom Robin , Freedman Eric
Published: June 2014

Increases in access to information and communication technologies (ICTs) have given citizens new tools to organize politically. This development has particular importance for those living under authoritarian regimes that rely on the repression of free speech to maintain power. These repressitarian elites resort to a variety of means to establish (or re-establish) control over citizen online communications. However, it is counterproductive for countries to crack down too tightly on Internet expression, because such actions can create negative economic consequences for countries hoping to engage in the 21st century’s wired economy. The friction between online free expression and government repression is playing out with close interest of Western governments, human rights advocates, and citizens because it places many technology companies in the difficult position of either facilitating such government repression or finding themselves unable to compete in those markets. This chapter examines recent developments in Iran, Egypt, China, and Singapore. All four countries have been identified as having severe impediments to free expression. Iran and Egypt, however, have seen the rise of some organized opposition movements despite the controls on media expression, while China and Singapore offer useful case studies on the economic dimensions of the balance between participating in the global networked society and controlling citizen expression. This chapter considers how financial and economic factors lead to more moderate views of Internet use in those countries and examine the struggles between maintaining openness and crackdowns.
“In YouTube We Trust”
Authors: Douai Aziz
Published: June 2014

YouTube has enabled new forms of political dissent in Arab societies. This chapter examines the development and rise of YouTube in the Arab world. In particular, it looks at how this video exchange site is invigorating the online public sphere’s vigorous demand for political reform and respect for human rights. Specifically, this investigation explores how social networking capabilities have made YouTube an effective asset in dissidents’ arsenal among Arab activists. To examine the vibrancy of this fledgling online public sphere, the chapter scrutinizes how activists incorporated YouTube videos to shed light on human rights abuses, specifically police abuse, corruption, and brutality in two Arab countries, Egypt and Morocco. The chapter concludes with a discussion of the new campaigning modes that the Internet and YouTube have facilitated.
ICT and Human Rights in Brazil
Authors: Filho José Rodrigues
Published: June 2014

Since the end of military government in Brazil, civilian governments have sought the accumulation and exercise of power to the detriment of the citizenry. They have done this with a kind of totalitarianism that takes the form of digital or bureaucratic dictatorship. Since the 1990s, they have started to implement information technology in the public sector to regulate and run the country in a command-and-control way through technological or bureaucratic dictatorship rather democratic process. While it is evident that there is a high level of investment in information technology in the public sector (e-government) in Brazil, there are also clear signs of the violation of human rights in terms of privacy. These occur, for instance, when the public administration exercises the power to engage in a process of electronic surveillance without the supervision of the judiciary. It is alleged that thousands of individual files have been accessed in the public administration in Brazil, despite the privacy protection offered by the national constitution. In addition, there is a proliferation of biometric identification using faces, eyes, fingerprints, and other body parts, especially in the e-voting system. This chapter shows how information technology (e-government) in Brazil could lead to violations of human rights because of the proliferation of biometric identification in the e-voting system as well as other sorts of invisible electronic surveillance that are affecting civil liberties and individual rights, including privacy.
Contingency and Hybridity in the Study of Digital Advocacy Networks
Authors: Wilson Christopher , Dunn Alexandra
Published: June 2014

This chapter proposes an analytic approach for the study of ICTs in contentious politics and human rights advocacy. By applying the analytical frames of contingency and hybridity to study design, this approach aims to promote empirical analyses, strengthen data comparability, and improve understanding into how human rights activists strategically combine digital and grounded communications to respond to complex and changing environments. The authors explore this analytic approach and its implications through a close analysis of the Front to Defend Egyptian Protesters (FDEP), a Cairo-based initiative utilizing multiple digital media to mobilize support teams for arrested protesters and work towards their release. Applying the analytical frames of contingency and hybridity to FDEP activities in 2010, prior to the uprisings now commonly referred to as the Arab Spring, the chapter observes a number of opportunities for targeted data collection. It closes by observing the challenges and opportunities this poses to the contemporary study of digital activism.
Performance of RHA Blended Cement Concrete under Sodium Chloride via Wetting and Drying
Authors: Dewi Sri Jayanti , Ramadhansyah Putra Jaya , Norhidayah Abdul Hassan , Md. Maniruzzaman A. Aziz , Hainin Mohd Rosli , Che Norazman Che Wan
Published: June 2014

This paper investigates the effects of concrete containing RHA subjected to sodium chloride solution (5% NaCl) under wetting and drying cycles. Five levels of cement replacement (0%, 10%, 20%, 30% and 40% by weight) were used. The total cementitious content used was 420 kg/m3. A water/binder ratio of 0.49 was used to produce concrete having target strength of 40 MPa at the age of 28 days. The performance of blended cement concrete was evaluated using compressive strength, chloride ion-penetration and chloride penetration depths. The results showed that the RHA blended cement concrete performed better than Portland cement concrete when exposed to 5% sodium chloride solution via cyclic wetting and drying conditions. RHA can reasonably be used as a cement replacement material for the purpose of reducing the chloride ion-permeability of the concrete, which in turn will increase its durability. Generally, a RHA replacement level of 10% or 20% is sufficient to enhance resistance to sodium chloride.
Double Layer Concrete Paving Blocks Using Waste Tyre Rubber as Aggregate Replacement
Authors: Jusli Euniza , Md Nor Hasanan , Ramadhansyah Putra Jaya , Zaiton Haron
Published: June 2014

This study provided the test results on the mechanical properties of double layer concrete paving blocks (CPBs) obtained by replacing portions of the conventional aggregate with waste tyre rubber. The mechanical properties discussed in this paper were compressive and flexural strength. Results indicated that the density of double layer CPBs containing rubber was lower than that of conventional CPB. The decrease was found to be proportional with the waste tyre rubber content. Due to the low strength and stiffness of waste tyre rubber particle, the compressive and flexural strength of double layer CPBs containing rubber appeared to be lower than that of conventional CPB.
Electrical Properties Investigation of Unsaturated Polyester Resin with Carbon Black as Fillers
Authors: Revati R. , Yahud S. , Majid M.S. Abdul
Published: June 2014

In this paper, conducting polymer composites were prepared by adding different percentage of carbon black (2, 4, 6 and 8)% to unsaturated polyester resin. Hence, this project focuses on two types of carbon black which is commercially available that is activated carbon black and carbon black produced internally from water hyacinth. Their effect on the electrical properties of the polyester compositewas analyzed. The A.C. electrical conductivity of the polyester composite was studied using Precision LCR meter. The A.C. electrical conductivity of polyester-carbon black composite has been investigated at a frequency ranging from 50 Hz to 1 MHz. The result showed that the electrical conductivity ofthe composite was changing with different concentration of carbon black. It has been observed that the electrical conductivity of the composite is frequency dependent and increases with increasing percentage of carbon black fillers in the polyester composite.
Stress Analysis of Adhesive Bonding of Urea Granulator Fluidization Bed
Authors: Nor Bakyah Abu , Afendi Mohd , Abdul Majid Mohd Shukry , Abdullah Abdul Rahman , Shahriman Abu Bakar
Published: June 2014

Stress analysis of adhesive bonding of urea granulator fluidization bed was performed by using finite element method. The main objective of this project is to develop an alternative joining technique for urea granulator fluidizationbed by using adhesive bonding. The problem can solve by using commercial finite element package ANSYS version 13.0. T-joint and double T-joint are the main adhesive joints which will be focused in this project. The stresses on stainless steel plate can reduce by increasing the thickness of adhesive as demonstrated in numerical analysis results. Different thickness of adhesive will give different value of maximum von Mises stress. It shows that greater thickness resulted in higher maximum. This analysis proves that increasing the adhesive thickness will reduces the joint strength because stress was concentrated more on the adhesive interfaces. The adhesive bonding on T-joint is stronger than other design of joint because it need lower stress. It followed by first design of double T-joint and second design of double T-joint.
Mechanical Properties of Vinyl Ester Resin/Epoxidized Plam Oil/Nanoclay Composite
Authors: Khalili Amirali , Rahmat Abdul Razak , Fakhari Alireza , Alsagayar Zyad Salem
Published: June 2014

The aim of this study is to develop vinyl ester resin (VE) with enhanced mechanical and thermal properties. Nanocomposites vinyl ester resin (VE)/ epoxidized palm oil (EPO)/ clay were prepared at different amount of epoxidized palm oil (EPO) (5, 7.5 and 10 wt%) in presence of various ratio of clay (1,2 and 3 phr) by free radical polymerization. The curing agent for polymerizing nanocomposites was methyl ethyl ketone peroxide (MEKP). Studies on their mechanical and physical properties were carried out by tensile and flexural tests. The results obtained revealed interactions between the vinyl ester resin (VE) and epoxidized palm oil (EPO). Based on the results of tensile strength, the optimum loading content for EPO and clay was 5wt% and 1 phr, respectively. When the concentration of EPO increased, the ductility was improved, indicated higher toughness.
Development of Mathematical Equation for Chip Serration Frequency in End Milling of Titanium Alloy (Ti6Al4V) under the Influence of Magnetic Field from Permanent Magnets
Authors: Sulaiman Syidatul Akma , Amin Akm Nurul
Published: June 2014

Machining of metals is generally accompanied by a violent relative vibration between work and tool, known as chatter. Chatter arises due to resonance when the vibrations of the instability of chip formation and the natural vibration modes of the machine-system components coincide. This paper focuses on a novel approach of minimizing chatter in end milling of Titanium alloy (Ti6Al4V) under magnetic field from permanent magnets. The method consists of two ferrite permanent magnet bars (dimensions: 1′′ x 6′′ x 3′′), mounted 5mm from the cutting tool using a specially designed fixture, to provide a uniform magnetic field of 2500-2700 Gausses (approximately). A titanium alloy Ti6Al4V block was then end milled using uncoated WC-Co inserts.The experiments were designed using the Design Expert software with three independent variables; cutting speed, feed, and depth of cut. Machining tests were conducted for two different conditions – with and without the application of magnets. Scanning Electron Microscope (SEM) was used to measure the chip segmentations.The SEM analysis of chip serrations demonstrated that the chip formations were more stable while cutting under the presence of permanent magnets due to lower intensity of chatter. Keywords: Chatter, Chip Serration Frequency, Permanent Magnet, Titanium Alloy.
Optimization of Preparation of Microwave Irradiated Bio-Based Materials as Porous Carbons for VOCs Removal Using Response Surface Methodology
Authors: Mohammed Jibril , Nasri Noor Shawal , Zaini Muhammad Abbas Ahmad , Dadum Usman Hamza , Ahmed Murtala Musa
Published: June 2014

Effluents from various industries release volatile organic compounds (VOCs) into the environment which causes serious environmental problems. Coconut shell based porous carbons (CSPC) were synthesized with potassium hydroxide as activating agent for adsorption of Benzene and Toluene. Central composite design (CCD) method under the response surface methodology (RSM) of the Design expert software version 7.1.6. was employed in the optimization of the preparation conditions of the porous carbons. The effects of three preparation variables (i.e. microwave power, irradiation time and KOH impregnation ratio) on Benzene and Toluene adsorption were studied. Based on the CCD, quadratic models were developed to correlate the preparation variables to the responses (Benzene and Toluene adsorption). The influence of process parameters on the properties of CSPC was examined using analysis of variance (ANOVA) to identify the significant parameters. The optimum condition was obtained at microwave power of 500W; irradiation time 4mins; and 1.5 KOH impregnation ratio, which resulted in 84% of Benzene and 85% of Toluene respectively at 95% yield.
Effect of Low Current for Machining Pit Using Electrical Discharge Machine
Authors: Syahrullail Samion , Razak M. Daud , Sapawe Norzahir , Yahya Azli , Kartiko Nugroho
Published: June 2014

Electric Discharge Machining Die sinker (EDM DS) is an established technology for surface modification. In this study, experiment were conducted using electrical discharge machine die sinker ZNC to investigate the effect of low pulse current rates to produce pits on SKD 11 (tool steel). Various parameters are considered during machining such as pulse current, gap voltage and dicharge time. Experiments were performed by three pulsed current levels (0.5A, 1.5A and 3.0A). The hollow copper rod as electrode with diameter 0.5mm is used to make spark surface of SKD 11. The experimental result reveals that the pit shape of a surface SKD 11 is significant to low pulse currents. For qualitative analysis, a distinction diameter pits and shapes represented with different low pulsed current. Overall, this study shows that presence of pits of surface embedded on the handle tool and machinery part will improve the existing technology available in surface modification.
Effects of Silicone Surfactant on the Water Absorption and Surface Morphology of Rigid Palm Oil-Based Polyurethane Foam
Authors: Farhana Shakira Md. Akhir , Mohd Haziq Dzulkifli , Nurfatmah Pz Nik , Majid Rohah A.
Published: June 2014

Polyurethane (PU) foams are widely used today in automotive and as insulation system. Due to environmental issues, efforts have been made to replace petrochemical polyol with natural-based polyol in PU foam production, without sacrificing any properties. This study aims to produce palm oil-based PU rigid foam for non-load bearing applications such as wall panel or insulation for buildings. Two parameters studied were percentage of water uptake and surface foam morphology. Palm oil-based polyol (POP) was reacted with polymeric 4,4-diphenylmethane diisocyanate (p-MDI) at 1:1 NCO:OH ratio. Water was used as blowing agent and silicone surfactant was added to produce stable rigid PU foam. The content of silicone surfactant was varied at 2 and 3 part by weight (pbw). The percentage of water uptake increased slightly with increasing surfactant contents due to siloxane portion of the surfactants, is thought able to reduce the surface tension of the cell, thus absorbing more water than 2 pbw surfactant content. The findings were supported with micrographs of scanning electron microscope (SEM) that showed a larger cell window area and thicker strut.
Effect of Rice Husk Ash Fineness on the Properties of Concrete
Authors: Dewi Sri Jayanti , Ramadhansyah Putra Jaya , Norhidayah Abdul Hassan , Md. Maniruzzaman A. Aziz , Hainin Mohd Rosli , Wan Ibrahim Mohd Haziman
Published: June 2014

In the present research, the effect of rice husk ash fineness on the properties of concrete was studied. Eight different fineness grades of rice husk ash were examined. A rice husk ash dosage of 15% by weight of binder was used throughout the experiments. The water-to-binder ratio was 0.49 to produce concrete having target strength of 40MPa at 28 d. Workability, compressive strength and gas permeability tests were carried out to identify the properties of concrete. The results revealed that increasing the fineness of RHA by mechanical grinding was found to improve the workability of RHA blended cement concrete. In addition, the use of RHA3 with mean particle size of 9.52μm produces the concrete with good strength. Finally, significant improvement was observed in mixtures incorporating RHA in terms of permeability coefficient.
Effect of Zinc Coating Thickness on Corrosion Performance of Mild Steel in Atmospheric and Seawater Environment
Authors: Idora M.S. Noor , Rahman M.M. , Ismail M. , Nik W.B. Wan
Published: June 2014

The application of zinc coating as a protective film to the mild steel against corrosion attack in atmospheric and seawater environment was studied. The objective of this study is to evaluate the corrosion performance of mild steel coated by different thickness of zinc under salt spray and also immersion test. The corrosion measurement test was performed by weight loss and potentiodynamic polarization. From the experimental study, it was found that the corrosion rate of mild steel is inversely proportional to the zinc coating thickness. The result also showed that the corrosion rate of mild steel in the salt spray test is higher than the immersion test.
Application of the Lattice Boltzmann Method for Fluid Flow around Complex Geometry
Authors: Jahanshaloo Leila , Che Sidik Nor Azwadi , Kermani Emad
Published: June 2014

In recent years, several strategies have been proposed to deal with complex geometry to study particle-fluid interaction using lattice Boltzmann method. Curved boundary treatments have been suggested to improve the accuracy of the stair-shaped approximation in conventional lattice Boltzmann simulations. This paper presents numerical analysis of three interpolation methods for confined flow around blockage positioned inside a channel. A two-dimensional nine velocity lattice arrangement was chosen to discretize the fluid domain and single relaxation time technique is applied in this study. The results are presented in terms of velocity contour, lift and drag forces variation for three different shapes of blockage. The simulations results are then compared with those obtained using the three different interpolating treatments. Some of these methods show more adaptability for force evaluating on distinct surfaces.
Film-Cooling Techniques at the End of Combustor and Inlet of Turbine in a Gas Turbine Engine: A Review
Authors: Che Sidik Nor Azwadi , Ehsan Kianpour
Published: June 2014

This study was carried out to extend database knowledge about the film cooling holes function at the end of combustor and inlet of turbine. Using the well-known Brayton cycle, rising the turbine inlet temperature, is the key to get higher engine efficiency in gas turbine engines. But the high temperature of the combustor exit flow causes non-uniformities. These non-uniformities lead to a reduction in the expected life of critical components. Therefore a cooling technique should be designed to protect these parts. There are two separate ways for Gas turbine cooling: internal cooling and external cooling. Film cooling is one of the most effective external cooling methods. In this system, a low temperature thin boundary layer such as buffer zone is formed and attached on the protected surface. In this study, a literature survey was done on the limited surveys, particularly since the first of 21th century.
Energy Savings on Automotive Air Conditioner Using Liquid-Suction Heat Exchanger Subcooler
Authors: Wahyu Budi Mursanto , Sumeru Kasni , Azhar Abdul Aziz , Henry Nasution
Published: June 2014

The present study describes a numerical analysis of the effect of subcooling using liquid-suction heat exchanger (LSHX) on the performance of automotive air conditioner. Besides increasing the cooling capacity, subcooling using LSHX also generates superheating in the suction of the compressor, where the superheating ensures only vapor phase of refrigerant entering the compressor suction and reduces the risk of damage to the compressor. The results show that the refrigeration capacity improvements and COP improvements up to 11.86% and 5.64%, respectively, for the subcooling of 1 K to 10 K and the condenser temperature of 40°C to 50°C.
Numerical Analysis of Modified Ejector Cycle on Ejector as an Expansion Device on Residential Air Conditioner
Authors: Sumeru Kasni , Nasution Henry , Ani Farid Nasir
Published: June 2014

The present study describes thermodynamic modeling of a novel cycle of ejector as an expansion device - called modified ejector cycle (MEC) - on residential air conditioner (A/C) to further enhance the COP improvement on standard ejector cycle (SEC). The difference between the SEC and MEC is the separator, namely the SEC uses a separator that has an inlet and two outlets, whereas in modified ejector cycle (MEC), the separator has only an inlet and an outlet in the system. Due to its environmental friendliness of R290 (propane), it is used to replace R22 as a working fluid in the numerical. The modeling results on the residential air conditioner with cooling capacity of 2.5 kW using R290 as working fluid showed that the COP improvement of the MEC was 42.86% at the condenser temperature of 45°C.
Bio-Oils Characteristic from Oil Palm Biomass from Different Fast Pyrolysis Techniques
Authors: Ani Farid Nasir , Salema Arshad Adam , Hasan Ismail
Published: June 2014

Pyrolysis is one of the effective ways to convert biomass into energy and value added products. Till date, no comparative study has been done on the characteristic of bio-oils of oil palm shell (OPS) and empty fruit bunch (EFB) from various fast pyrolysis techniques. This includes fluidized bed, fixed bed, rotating cone, microwave and others. Thus, the main objective of this paper was to analyze the characteristics of OPS and EFB bio-oils obtained from these processing techniques. Temperature was found to be the key parameter for the quality of bio-oils. Besides the various pyrolysis techniques, the lignocellulosic constituents of oil palm biomass also influence the chemical composition of the bio-oils. Overall, chemical analysis of OPS and EFB bio-oil through GC-MS has shown variation in the amount of phenol and its derivatives.
Potential Analysis of Rice Straw as an Alternative Energy Source for Substitute Coal in Indonesia
Authors: Makhrani
Published: June 2014

The study of the potential of rice straw was conducted to determine the potential energy of rice straw available as substitute energy sources of coal in Indonesia. The statistical data of rice production Indonesia in 2001-2012, used to analysis of the development potential of rice straw each year. Province are analyzed by 27 provinces have greater rice production of 100,000 tons per year. The analysis showed that the potential of rice straw and potential electrical energy increased by approximately 36.8 % over 12 years, an increase of approximately 3.1 % per year. The potential of rice straw in 27 provinces gained about 91.753 million tons which is equivalent to approximately 50.974 million tons of coal, electrical energy potential of about 382.305 GWh, and the potential power capacity about 43.642 MW. It was concluded that the energy potential of rice straw in 27 provinces in Indonesia is quite large and is increasing every year. Exploiting this potential as a source of electrical energy, can overcome the shortage of electrical energy and can reduce the use of coal in Indonesia.
Simulation of Flow over a Cavity Using Multi-Relaxation Time Thermal Lattice Boltzmann Method
Authors: Che Sidik Nor Azwadi , Ali Khan Aman
Published: June 2014

This article provides numerically study of the
multi-relaxation time
thermal
lattice Boltzmann method
(LBM)
for compute the
flow
and isotherm
characteristics in the
bottom heated
cavity located o
n a floor of horizontal channel
.
A double-distribution function (DFF)
was
coupled with MRT thermal LBM to
study
the effects
of
various grashof number (Gr),
Reynolds number
(Re)
and Aspect Ratio
(AR)
on the flow
and isotherm
characteristic.
The results we
re compared with the conventional single-relaxation time lattice Boltzmann scheme and benchmark solution for such flow configuration.
The results of the numer
ical simulation indicate that
multi-relaxation time
thermal
lattice Boltzmann scheme demonstrated good agreement, which supports its validity in computing fluid flow problem.
Study of Effect of Thermal Diffusivity on Ground Temperature for Malaysian Climate
Authors: Yusof Taib Mohd , Anuar Shahrani , Ibrahim Hassan
Published: June 2014

Ground has been proven that it is able to supply cooling and heating resulting in significant reduction of electricity consumption. This paper discusses potential of ground towards implementation of ground thermal storage by using ground heat exchanger (GHE) to supply passive cooling for any application. Analysis has been conducted based on empirical equation from conduction heat transfer for depth up to 6 m and thermal diffusivity from 0.04 to 0.1 m2/day. The main input parameters were obtained from local weather station for three consecutive years. The results showed that significant reduction of temperature occur at depth below than 2.0 m in which cooling can be supplied constantly throughout the year. Temperature amplitude also gets attenuated relatively with depth in which amplitude less than 1°C occur at depth more than 4 m for thermal diffusivity 0.04 m2/day. In addition, thermal diffusivity plays important role in determining ground temperature variation. It has been obtained that the temperature amplitude significantly increase when the thermal diffusivity increase. Therefore, this paper had suggested that the application of GHE should be placed in condition of thermal diffusivity 0.06 m2/day and below.
Microwave Assisted Pyrolysis of Waste Biomass Resources for Bio-Oil Production
Authors: Mushtaq Faisal , Channa Abdul Sami , Mat Ramli , Ani Farid Nasir
Published: June 2014

The agro-industrial sector of many countries generates considerable quantity of waste biomass and potential exploitation of this reside is necessary for economic and environmental reasons. Pakistan is an agricultural based country with widespread amount of crop residue generated annually. This study utilized rice husk, sawdust and bagasse residues to investigate the effects of microwave absorber loading on process temperature, pyrolysis products, and bio-oil composition using multimode microwave pyrolysis system operated at 300W and 2.54GHz. The results indicated that pyrolysis process temperature depends on the type of waste residue and microwave absorber loading. The maximum bio-oil yield of 22.41wt%, 33.61wt% and 19.1wt% were produced at 75wt% microwave absorber loading from rice husk, sawdust and bagasse, respectively. The D-Allose of 21.95 %area, dodecanoic acid of 71.22 %area and octasiloxane of 74.50 %area under GC-MS in rice husk, sawdust and bagasse bio-oils, respectively suggests potential use as chemical feedstock.
Keywords: Waste biomass; microwave absorber; microwave assisted pyrolysis; process temperature; product distribution; bio-oil composition
Evaluation of Paraffinic Mineral Oil as Lubricant in Cold Work Extrusion Process
Authors: Syahrullail Samion , Nurul Aini Mohd Ahyan
Published: June 2014

In this paper, the effect of frictional constraint from the application of three different viscosity of additive free paraffinic mineral oil as lubricant were investigated by cold work forward plane strain extrusion experiments. The experiment used a cold work plane strain extrusion apparatus consist of a pair of taper die and a symmetrical workpiece (billet). The billet material was annealed pure aluminum A1100 with radius 5 mm in deformation area. The experimental result shows that the higher viscosity, will lead to lower friction effect to the deformed area, as well as product area.
Phenolic Rich Components Identification of Heavy Oil Fractions of Biomass Pyrolytic Oil for Epoxy Resin Binder
Authors: Ahmed Murtala Musa , Nasri Noor Shawal , Mohsin Rahmat , Hamza Usman Dadum , Mohammed Jibril
Published: June 2014

Identification and assessment of phenol and phenolic rich components of heavy oil fractions of biomass pyrolytic oil were conducted. The original bio-oil used for this study was derived from the pyrolysis of empty fruit bunch (EFB). It was separated into water soluble (light oil) and water insoluble (heavy oil) components by mixing it with water at 2:1 V/V ratio under ambient condition with vigorous stirring using centrifuge for 30mins. The raw bio-oil and the heavy oil fractions were later characterized using Fourier Transform Infra-Red (FTIR) and Gas chromatography-Mass spectroscopy (GC-MS) techniques in order to identify the function groups present and their compositions. The GC-MS results for the heavy oil indicated a high concentration of phenol and phenolic components, which was strongly supported by the presence of OH group (characteristic of phenol) from FTIR analysis. Utilization of bio-oil which was known to have a significant amount of phenol and phenolic rich components for phenolic, novolac or epoxy resin manufacture would significantly reduce the cost and negative environmental effects of the fossil-based resins.
Finite Element and Experimental Study of Friction and Lubricants in Strip Drawing
Authors: Hafis Mohd Bin Sulaiman , Ridzuan Mohd Jamir Mohd , Mohamed A.R. , Farahana Ramli Nur
Published: June 2014

This study presents the results of experimental and finite element (FE) simulation work carried out to evaluate friction and lubricants that play a role in the increased forming load distributions. The experiments showed significant increases in forming load and visual pattern change was observed on the formed strip surfaces. This indicates that the tool-strip interaction is playing the dominant role in the increase in forming load observed. FE simulation was undertaken to analyse the details of forming operation and to determine mechanisms behind the increased forming load. It was found that the stresses were greater once the strip started to flow out through the tool die opening that required high forming loads. It is concluded that results from the tool-strip interaction is the main cause of the increased forming loads observed in strip drawing.
Prototype of Compact Flexural Fatigue Testing Machine
Authors: Mohd Jasri Muhammad Azrie Husainy , Afendi Mohd , Fauzi A.H.M.
Published: June 2014

The purpose of this project is to build a prototype of compact flexural fatigue testing machine and to strive for an easy working-environment as required by the users besides cutting the cost of the machining. This particular project is about to build the prototype of compact flexural fatigue testing machine in compact mode. In this project, the prototype will be functioning 60% similar to the real fatigue machine which is Dynamic Fatigue Testing Machine (INSTRON) due to timer counter, frequency and load applied. But the new invention is this prototype was using the concept of electromagnetic force relay that will apply to the specimen using the application of basic electronics. The motion sensor also being applied to this prototype to achieve accurate results when the specimen breaks up after undergoes a fatigue failure.
A Review of Porous Concrete Pavement: Applications and Engineering Properties
Authors: Ramadhansyah Putra Jaya , Mohd Ibrahim Mohd Yusak , Mohd Rosli Hainin , Wan Ibrahim Mohd Haziman
Published: June 2014

Porous concrete technology has been used since 1970s in various parts of the United State as an option to complex drainage systems and water retention areas.Porous concrete pavements have become popular as an effective stormwater management device to control the stormwater runoff in pavement. The objective of this paper is to study a pre-review on Porous concrete pavement and it previous laboratory study. From the literature, it was found that, the strength of the porous concrete pavementstill need to improve. To improve the strength of the porous concrete, various additive have been study as a part of porous concrete mix and yetthe optimum condition to produce good porous concrete still not been established. From the previous study, it was found that to prepare the porous concrete laboratory specimen, the use of standard Proctor hammer (2.5kg) and Pneumatic press (70 kPa compaction effort) resulted in the closest properties to the field porous concrete.
Short-Term Test of ±55 ̊ Filament Wound GRE Composite Pipes under Multiaxial Stress Ratios
Authors: Pranesh Krishnan , Majid M.S. Abdul , Afendi Mohd , Marzuki Haslan , Mohd Kazim Mohd Nor Fakhzan
Published: June 2014

This paper discusses the the development of an automated pressure testing rig to perform a short term test; Ultimate Elastic Wall Stress (UEWS) for ±55 ̊ glass fibre reinforced epoxy (GRE) composite pipe under various stress ratios. The prototype is capable of determining the stress-strain response caused by the static and cyclic pressure. This developed rig is to provide an alternative solution for the current qualification procedure explained in ISO14692 through ASTM 2992. As part of the work, an automated testing rig powered by labview program is developed with the aid of pressure sensors, solenoid valves and strain gauges which are interfaced through hardware modules from National Instruments. The UEWS test for the five stress ratios namely pure hydrostatic (2H:1A), pure hoop (1H:0A), pure axial (0H:1A), hoop to axial (1H:1A) and quad hoop to axial loading (4H:1A) were performed upon the ±55° filament wound glass-reinforced epoxy pipes. The changes in the stress strain response are captured from the strain gauge measurements and the UEWS failure points are calculated for all the loading conditions. The failure envelope developed from the failure points can be used to predict the long term performance of the GRE pipes and provide the benchmark for the design of composite pipes under various stress ratios.
Multi Objective Optimization of Surface Roughness and Workpiece Surface Temperature in Turning Operation
Authors: Nooraziah Ahmad , Tiagrajah V. Janahiraman
Published: June 2014

This paper presents the optimization of multiple performance characteristics (surface roughness and workpiece surface temperature) based on the Taguchi method. Three controllable factors of the turning process were studied at three levels. The single objective optimization was conducted using Taguchi method. The multiple Signal-to-Noise (MSNR) value was used to correspond to multi objective cases. The optimum combination of cutting parameters was obtained based on the highest value of MSNR.
The Interlaminar Shear Strength Test of Helical Wound Glass Fibre Reinforced Epoxy Laminates Subjected to Hydrothermal Ageing
Authors: Majid M.S. Abdul , Afendi Mohd , Daud R. , Amin N.A.M. , Mohamad Azizul , Hekman M.
Published: June 2014

This paper presents the experimental investigation of interlaminar shear strength (ILSS) tests of helical wound glass fibre reinforced epoxy (GRE) pipes subjected to hydrothermal ageing. Currently, the test is being used by composite pipes manufacturers as the alternative internal quality monitoring program for detection of manufacturing changes and reconfirmation of the design basis of composite pipes. The test specimens were cut in hoop direction from helically wound GRE composite pipes after exposure of 0, 250, 500, 1000-hour water at 80°C. The ILSS tests of the GRE samples were then conducted in accordance with ASTM D2344, and the results were analyzed to evaluate the durability performance of the laminates. The results show a clear degradation in the bonding strength between fibres and resin system interface after 500-1000-hour water exposure at 80°C. This findings show a good agreement in the trend observed with the standard qualification procedure elucidated in ASTM D2992 standard. Hence, ILSS test shows a great potential to be used as the internal short-term mechanical test method to qualify a new resin, curing agent or glass fibre in accordance to the next approach.
Shear Resistance of Trapezoidal Corrugated Web in Local Buckling
Authors: Usman Fathoni
Published: June 2014

This paper presents analytical studies using Eigenvalue buckling analysis in the Finite Element Method to determine shear buckling and subsequently determine shear resistance of thin plated member with trapezoidal corrugated web. The result is compared with experimental results. It is found that the proposed equations give good agreement to the experimental results. However, the buckling coefficient k is still not generate a good shear stress based on its slenderness ratio hw/tw.
Performance Analysis of Hydrocarbon Mixture to Replace R134a in an Automotive Air Conditioning System
Authors: Wellid Ismail , Sumeru Kasni , Azhar Abdul Aziz , Henry Nasution , Abioye A.M.
Published: June 2014

At present, most air conditioners in an automotive use R134a as working fluid. Due to the negative impact on the environment, i.e. global warming, the refrigerant must be replaced by environmental friendly working fluid. Hydrocarbons are natural fluids, no effect on the climate, inexpensive and readily available. The hydrocarbon mixture used in the present study is R436A, composed of R290 (propane) and R600a (isobutane) with a mass ratio of 56/44. The results show that the drop-in substitute from R134a to R436A reduced COP by 4.84, 4.74 and 4.64% for the condenser temperature of 40, 45 and 50°C, respectively. To generate COP improvement on the drop-in substitute, subcooling was carried out, and results show that the COP improvement was 4.42, 5.20 and 6.09% for the condenser temperature of 40, 45 and 50°C, respectively.