bluuebunny/crossref_metadata_2025 huggingface dataset:
The Quest for Economic Recovery
Authors: Tsakalerou Mariza , Lee Rongbin W. B.
Published: October 2014

Most organizations respond to an economic crisis by focusing on operational efficiency and/or on intellectual capital utilization and innovation. The conjecture is that intellectual capital confers distinct competitive advantage to an enterprise via knowledge management and knowledge spillovers and improved innovation capacity. Despite mixed empirical evidence to support this claim, intellectual capital and knowledge management remain at the forefront of an organization's agenda during an economic downturn. Recent surveys from the field indicate some dissatisfaction with practical knowledge management. These findings are difficult to interpret because at the same time organizations appear to adopt the position that management of knowledge resources is extremely important from a strategic perspective. The objective of this chapter is to provide some new perspectives on what drives success in the knowledge economy and to demonstrate how knowledge management is the ideal response to the challenge of innovation.
Improvement of Organizational Knowledge Transfer through Integration of Functional Silos in Smart Network
Authors: Todorović Ivan , Čudanov Mladen , Komazec Stefan
Published: October 2014

This chapter presents the possibility for improving inter-organizational knowledge transfer in the public sector by implementing adequate organizational change through analysis of public enterprises in one European capital. The structure of public enterprises is often fragmented in groups of specialized companies. Internal organizational models of particular companies are most often functional organizational structure models. Functional organizations are characterized by formation of organizational silos, where knowledge, power, and information can often be trapped and secluded from other parts of organization, among other structural weaknesses. Further, isolated structures exist not only on the level of functions within single organizations but also between different public companies in the same municipality, in spite of common ownership. Thus, knowledge transfer is restrained, not just among functions in individual organizations, but also on even higher levels, among different companies. The main purpose of this chapter is to describe how introduction of smarter, networked organizational forms can reduce these barriers and enable knowledge transfer.
Investigating the Associated Factors of Trust on Online Transactions
Authors: Lim Andriew
Published: November 2014

Although e-commerce is growing rapidly, it has not achieved its potential. A survey shows that more than fifty percent of online carts are abandoned. This paper investigates the associated factors of trust that influence customers in conducting online transactions. Through relevant literature study and questionnaire, this paper shows that privacy and security significantly affect customers' interpersonal trust on online transactions. The lower the customer perception of risk, the more they are inclined to conduct online transactions. The quality of the website also affects the customers' trust on online transactions. These aspects are strongly correlated to the reputation of the online merchants, which implicates the success of e-commerce itself.
Aerodynamics Performance of Endwall Film Cooling under the Influence of Purge Flow in High Pressure Turbine Cascade
Authors: Wan Aizon W. Ghopa , Funazaki Kenichi , Mansor Mohd Radzi Abu
Published: October 2014

Modern gas turbine requires sophisticated cooling technologies to avoid thermal failure due to the extreme operating environment. Film cooling is one of the most important cooling technologies used for gas turbine hot-section components, particularly for blade aerofoil surfaces and endwall. Previous research has shown that the endwall region is considerably more difficult to cool than the blade aerofoil surfaces because of the existence of complex secondary flow structures such as horse-shoe vortex, cross flow and passage vortex in the blade passage. Therefore, this study focuses on aerodynamics interaction of the cooling air through the upstream slot with the secondary flow field. Experiments carried out using 5-holes Pitot tube have revealed the secondary flow field at blade downstream of linear cascade of high pressure turbine. A baseline condition without any leakage flows was compared with the leakage ejection case. Finally, both cases were validated by simulations from commercial software, ANSYS CFX.
Design and Analysis of an Aircraft Composite Hinge Bracket Using Finite Element Approach
Authors: Mun Wai Chee , Rivai Ahmad , Bapokutty Omar
Published: October 2014

The use of composite materials in aircraft structures have been increasing for the past decade. The anisotropic and heterogeneous nature of composites remains a major challenge to the design and analysis of composite aircraft structures. Composite structures require a different design approach compared to the design of metallic structures. This paper aims to provide a step by step definitive guide to design and analyze composite structures using finite element approach. A simplified design model for the composite structural design was used to analyze an aircraft composite hinge bracket. The composite hinge bracket which is made of IM7/8552 laminated composite plates was successfully designed with a margin of safety of 0.216 and a weight savings of 43.77 percent was estimated.
Reverse Engineering of a Fixed Wing Unmanned Aircraft 6-DoF Model for Navigation and Guidance Applications
Authors: Burston Martin T. , Sabatini Roberto , Clothier Reece , Gardi Alessandro , Ramasamy Subramanian
Published: October 2014

A method for deriving the parameters of a six-degree-of-freedom (6-DoF) aircraft dynamics model by adopting reverse engineering techniques is presented. The novelty of the paper is the adaption of the 6-DoF Aircraft Dynamics Model (ADM) as a virtual sensor integrated in a low-cost navigation and guidance system designed for small Unmanned Aircraft (UA). The mass and aerodynamic properties of the JAVELIN UA are determined with the aid of an accurate 3D scanning and CAD processing. For qualitatively assessing the calculated ADM, a trajectory with high dynamics is simulated for the JAVELIN UA and compared with that of a published 6-DoF model of the AEROSONDE UA. Additionally, to confirm the validity of the approach, reverse engineering procedures are applied to a published CAD model of the AEROSONDE UA aiding to the calculation of the associated 6-DoF model parameters. A spiral descent trajectory is generated using both the published and calculated parameters of the AEROSONDE UA and a comparative analysis is performed that validates the methodology. The accurate knowledge of the ADM is then utilized in the development of a virtual sensor to augment the UA navigation and guidance system in case of primary navigation sensor outages.
Visualization of Flow Field and Wake over Clean and Under-Loaded Wings
Authors: Al-Kayiem Hussain H.
Published: October 2014

Experimental details of the flow field and wake over airfoils and 2-D wings are time and cost consumption. In this study, the flow visualization technique was adopted to investigate the flow field surrounding NACA4412 airfoil. The investigations were carried out in smoke tunnel, operating at low Reynolds number in a range of 105. The airfoil was tested in two operational cases: first as clean wing and the second as under-loaded wing by attached missile model. The experiments were conducted at various angles of attack as 00, 50,100, 150and 200. It was found that the under-load of external body under the wing is influencing the flow structure over the wing. Also, the wake after the external body is swirling, leading to very complicated wake interaction. The results from the work can support the numerical simulation and the prediction of the laminar to turbulent transition and the separation and wake interaction of high lift airfoil flow fields.
Performance Testing of Anechoic Chamber
Authors: Mustapha H. , Ismail K.H. , Daim T.J. , Jamil S.F.
Published: October 2014

Anechoic chambers are widely used in performing EMC measurements according to the established EMC standards. In space area, the elements of EMC measurements such as emission, immunity and susceptibility are critically important to ascertain that all of electrical and electronic components in the satellite body will function correctly without fail, thus ensures the smoothness of satellite operation upon launching into space. Realising this, level of anechoic chamber performance should always be in the optimum state as possible. This paper presents the specific tests that were carried out in the anechoic chamber as to determine the accuracy of its performance. All four types of tests were run in main chamber, control and amplifier room within frequencies range of 10 kHz to 20GHz. The tests will characterize the shielding effectiveness of RF shielded enclosure, the Field Uniformity Area (FUA), Site VSWR and Normalised Site Attenuation (NSA) of anechoic chamber. The basis of the measurement techniques is described and typical test results are discussed. Based on the results, it is concluded that the anechoic chamber is in good condition, ready for testing and capable to produce reliable output.
Towards an Optical Aircraft Navigation System
Authors: Chahl Javaan , Dawadee Aakash
Published: October 2014

Navigation by means that are fully self contained, without the weight and cost of high performance inertial navigation units is highly desirable in many applications both military and civilian. In this paper we introduce a suite of sensors and behaviors that include: the means to reduce lateral drift due to wind using optical flow, detection of a constellation of landmarks using a machine vision system, and a polarization compass that is reliable at extreme latitudes based on polarization. In a series of flight trials and detailed simulations we have demonstrated that a combination of these functions achieves purely optical navigation with simplicity and robustness.
Stores Separation Simulation Development: A Roadmap to System Realisation via Intelligent Data Management System
Authors: Faat Shamsul Bahri , Zhahir Amzari , Ahmad Mohamed Tarmizi , Ajir M.R.
Published: October 2014

An Intelligent-Data Management System (IDMS) for store separation analysis has been developed for Stores Separation Simulation program. The characteristics of the IDMS generically focuses on gathering, collecting, analysing, reporting, summarising and visualising validated data prior separation activity in simulated environment. The components of IDMS are Aircraft Configuration, Interface Configuration, Stores Geometry, Pylon Configuration and Cube (a multi-dimensional visibility of Form, Fit and Function stores-platform Data Verifier). Overall, this project combined information from separation patterns analysis by integrating multi-dimensional databases, systematic-data orchestration; rules based data mining for stores separation verifier into one data management system. This paper presents the program review of overall store separation simulation program.
An Evaluation of Economic Model for Assessing Aviation Environmental Impacts towards Airline Operations
Authors: Mohd Yunos Siti Nur Mariani , Abdul Ghafir Mohammad Fahmi , Wahab A.A.
Published: October 2014

Environmental concerns due to aviation emissions and noise have resulted in introduction of emission and noise charges imposed by airports to airline operators. In order to assess the impact of emission and noise towards the airline's operating costs, this paper presents the initial work in developing an economic model and explains the validation and application of the direct operating cost (DOC) estimation used by the model. A comparison with another two DOC estimation methods has also been performed. The results indicate that the estimated cost is in a good agreement with the data from the public domain despite the differences with data from other estimation methods due to the variation of approach adopted by each model. Finally, an inclusion of environmental charges in DOC is also presented, which shows the amount is relatively small. Nonetheless, in order to ensure a sustainable airline operations, further actions in reducing aviation emission and noise are essential.
Comparison of Digital DATCOM and Wind Tunnel Data of a Winged Hybrid Airship’s Generic Model
Authors: Ul Haque Anwar , Asrar Waqar , Omar Ashraf Ali , Sulaeman Erwin , Ali J.S. Mohamed
Published: October 2014

Use of low fidelity tools in designing subscale generic wind tunnel models is usually required to get first-hand knowledge about general trends of aerodynamic and stability parameters. Most of such tools are limited to well-defined conventional aircraft configurations. In the present work, aerodynamic and stability characteristics of a winged hybrid airship is explored at low subsonic speed by using Aircraft Digital DATCOM, which is based on semi-empirical methods for preliminary aircraft geometries. Spheroidal ellipsoidal shaped hull of the airship is modeled in DATCOM along with the geometrical details of wing and empennages. The prediction of zero lift drag coefficient, coefficient of lift and pitching moment is the focus of this paper. Except the drag coefficients, trends of analytical results compare well with experimental data.
Wing-in-Ground Effect Vehicles Flight Automatic Control Systems Development Problems
Authors: Nebylov Alexander , Nebylov Vladimir
Published: October 2014

The Wing-in-Ground Effect vehicles (WIG-craft, Wingships) or Ekranoplanes as they are called in Russia are developing in several countries and the problem of perfect flight control is very important for these vehicles' successful application either for commercial or military. An accident-free flight at very low altitude above the rough underlying surface, mainly above the disturbed sea surface, and also take-off and landing require special systems of motion control that are different from those used on planes. The requirements for such motion control systems and the new criteria for their improvement are offered. The aim of this investigation is to define the way for operational performance improvement of the vehicles of advanced design. The experience and achievements in this field of high technology are described.
A Review on the Impact of Aircraft Cabin Air Quality and Cabin Pressure on Human Wellbeing
Authors: Zubair Mohamed , Ahmad Kamarul Arifin , Riazuddin Vizy Nazira
Published: October 2014

Airliner cabins present more complicated scenario due to different design and operation challenges owing to the extreme environmental conditions, complexity of the operational systems, and the authorities that govern such environments. The scientific evaluation is rendered difficult due to lack of empirical evidence determining the airliner cabin air quality as well as consequent health effects occurring due to short or long flight exposure. Crew members and passengers report dizziness, fatigue, headaches, sinus and ear problems, dry eyes and sore throats during and after travel. There are persistent concerns about the transmission of infectious agents such as influenza, tuberculosis and measles viruses during flights. Moreover, a systematic collection of data related to airplane environmental exposures is not yet available and the effects of environmental conditions on wellbeing of travelers and their comfort level are yet to be fully ascertained. In this work, a systematic review of the air quality inside the airliner cabin are discussed. The potential pollutants and their established causes are discussed. In addition to this, major health discomforts faced by the occupants are presented.
Effective Range of Unmanned Aerial Vehicle (UAV) in the Malaysian Army Tactical Operations
Authors: Abu Hassan Shamil
Published: October 2014

Unmanned Aerial Vehicle (UAV) has been used in military application even during the conflicts in World War II. The utilization of UAV was further expanded during the Vietnam War and the role of “eye in the sky” has seen UAV became the ultimate ISTAR (Intelligence, Surveillance, Target Acquisition and Reconnaissance) tool for almost all conflicts. The evolution of UAV in various sizes and features will see UAV saturating the battlefield theater’s cloud in the future. This paper is to present the concept of operations of UAV in the military, segmented by units in battle to enable researchers to concentrate their research on types of UAV to suit the needs of the Malaysian Army. Using effective firepower range of all Malaysian Army arsenals and the commonality in terms of tasking, this study is able to establish the classes in terms of range needed for UAV in the Malaysian Army. From the observation, it is clear that the majority of the intended UAV will be operating in the less than 3 km combat radius.
Study of Wake Profiles of a Simplified Model of High Speed Train Using RANS and LES Turbulent Models
Authors: Mohd Salleh Sufiah , Mat Ali Mohamed Sukri , Shaikh Salim Sheikh Ahmad Zaki , Muhamad Sallehuddin , Mahzan Muhammad Iyas
Published: October 2014

Flow structure over bluff bodies is more complex in wake. The wake is characterized by the unsteady behavior of the flow, large scale turbulent structure and strong recirculation region. For the case of high speed train, wake can be observed at the gap between the coaches and also on the rear coach. Wakes formation of high speed train are generated by free shear layer that is originated from the flow separation due to the sudden change in geometry. RANS and LES turbulent models are used in this paper to stimulate the formation of wakes and behavior of the flow over a simplified high speed train model. This model consists of two coaches with the gap between them is 0.5D. A total of four simulations have been made to study the effect of computational domain size and grid resolution on wake profiles of a simplified high speed train. The result shows that the computational domain can be reduced by decreasing the ground distance to 1.5D without affecting the magnitude of the wake profile. Both RANS and LES can capture the formation of the wake, but LES requires further grid refinement as the results between the two grid resolutions are grid dependent.
Control of Bubble Growth by Using Virtual Chamber Neck in Micro Nozzle Channel
Authors: Leu Tzong Shyng , Lin Chin Fong
Published: October 2014

In this paper, dynamic behaviors of different chamber neck designs are studied. Within a micro-nozzle channel, different chamber neck designs for controlling bubble growth are used, including conventional structural chamber neck as well as virtual chamber neck. Dynamics of bubble growth rates under different input signals and chamber neck configurations are measured using a high speed microscopic imaging system. The experimental results show that with the help of virtual chamber neck at upstream, the bubble interface will move faster toward the nozzle direction, which will enhance the actuation force of the liquid toward the nozzle direction.
Anti-Aliasing for the Visualization of Wavefield Propagation
Authors: Chia Chen Ciang , Lee Jung Ryul
Published: October 2014

Visualization of wavefield propagation has been evolving as one of the most significant nondestructive imaging methods for structural damage evaluation and shock analysis. Corresponding visualization systems that are commonly used are potentially affected by aliasing due to the nature of discrete sampling in spatial and temporal domains. This study was conducted to define the problem and produce a spatial sampling guideline for aliasing-free visualization. Experimental demonstration was given at various spatial sampling rates for comparison. The results verified that the guideline is valid and can be used for quick determination of aliasing-free spatial sampling rate prior to experiment. Special guideline for post-sampling optimization was also presented.
Modelling High Velocity Impact on Aluminium Alloy 7075-T6 under Axial Pretension
Authors: Kamarudin K.A. , Ismail Al Emran
Published: October 2014

This paper explains the utilisation of finite element model to analyse the ballistic limit of aluminium alloy 7075-T6 impacted by 8.33 g with 12.5 mm radius rigid spherical projectiles. This numerical study was compared with the results obtained experimentally. During impact, the targets were subjected to either non- or uniaxial- pretension and the projectile travelled horizontally to the target. It was observed that pretensioned targets were more vulnerable, which reduced the ballistic limit. The existence of harmful failures owing to pretension impact was ascertained and compared with the non-pretension targets.
Modal Analysis of Thin Walled Multi-Cell Multi-Tapered Composite Beams of Closed Cross Sections
Authors: Ahmed Sohail , Ahmed M.N.
Published: October 2014

This paper explicitly highlights the modal analysis of thin walled multi-cell multi-tapered composite beams in cantilever configurations, using MSC Patran / Nastran finite element package. Initially, the verification of the model was done with the analytical results in order to ensure the model accuracy. All the multi-tapered beams under examination are composed of closed section and three cell configuration. There is a vivid description of all the effects of composite material and stacking sequence on the modal frequencies. It also suggests the ways to shift the natural frequencies of the multi-tapered beams. This paper verifies the effects of different geometrical configurations of beams (tapered angles, lengths and point of variation of tapered angles) on the modal frequencies. This research is also useful in aerospace industry while designing the aircraft wing, which would experience the vibrations due to wind gust and engine cycles.
A Computational and Analytical Study into the Use of Counter-Flow Fluidic Thrust Vectoring Nozzle for Small Gas Turbine Engines
Authors: Banazadeh Afshin , Banazadeh Farzad
Published: October 2014

This paper provides an understanding of counter-flow fluidic thrust vectoring, in the presence of the secondary air vacuum, applied to the exhaust nozzle of a micro-jet engine. An analytical and numerical study is performed here on a divergent collar surface adjacent to the cylindrical exhaust duct system. The vectoring angle is controlled by manipulating the momentum flux through a vacuum gap that is located on a circle concentric to the main nozzle. Three dimensional numerical simulations are conducted by utilizing a computational fluid dynamics model with two-equation standard k-ε turbulence model to study the pressure and velocity distribution of internal flow and nozzle geometry. Moreover, an analytical validation is carried out based on the known mathematical form of the governing equations of fluid dynamics over the sinusoidal wall. It is shown that the analytical results are in good agreement with numerical simulations, which also show that the pressure coefficient over the collar surface has the same trend as given by computational simulation. Similarly, the results of the numerical method are also verified against experimental results that were approved by previous research in area of numerical model for co-flow fluidic thrust vectoring technique.
The Effect of Demographics on Customer Satisfaction amongst Malaysia Hajj Pilgrims: Survey Result
Authors: Ahmad M.F. , Arif Mohd Shoki Md , Zakuan Norhayati , Rahman S.S.S.A. , Abdullah T.A.R. , Fadzil N.
Published: October 2014

Customer satisfaction (CS) is one of the most important criteria for business performance. Customer satisfaction contributes to the customer loyalty, which in turn helps improving performance of the organisation such as sales and profit. In order to survive in the operation and business with intense competition between enterprises, the focus of CS is important to ensure business excellence. This piece of work relates to a study on effect of demographic of Hajj Pilgrims on customer satisfaction. A questionnaire was prepared and given to 500 respondents of Malaysian Hajj Pilgrims which gave a 70.0% response rate or 350 respondents. Overall descriptive result depicts high level of CS, showing that Malaysia Hajj Pilgrims have high satisfaction towards Hajj services, which are being provided by Hajj Pilgrims organiser. Lembaga Tabung Haji (TH), which manages more than 80.0% of Malaysia Hajj Pilgrims every year, has performed the excellent performance towards CS. This study also shows that there are no significant differences in CS amongst demographics such as gender, age, occupation, academic status except category of Hajj Pilgrims.
The Effect of Bottom Ash on Fresh Characteristic, Compressive Strength and Water Absorption of Self-Compacting Concrete
Authors: Zainal Abidin Norul Ernida , Wan Ibrahim Mohd Haziman , Jamaluddin Norwati , Kamaruddin Kartini , Hamzah Ahmad Farhan
Published: October 2014

Bottom ash is a solid residue produced through combustion process in a coal-fired power plant. It has been catogarized as a waste and usually disposed in the utility disposed site. With higher demand on the power energy, more coal-power plant are constructed and abundance of bottom ash are produced. Recently, the utilization of bottom ash in the construction industry has gained the interest of researches. Since it has similiar particle size distribution as normal sand, many attempt has been made in studying it potential use in mortar and concrete. In complementary to that, this paper presents the effect of bottom ash on fresh and hardened properties of self-compacting concrete (SCC). Bottom ash is used as fine aggregate replacing sand with replacement ratio range from 0% to 30% by volume. The effects of bottom ash on the SCC were investigated by comparing the test result of SCC mixed bottom ash with control specimens (0% of bottom ash). The test result on fresh properties of the concrete mixture revealed that, as the replacement level of bottom ash increased, the slump flow, L-box passing ratio and segregation resistance ratio (SR) decreased. Nevertheless, the slump flow time (T500) result increased with the increased of bottom ash content. The results show that the porosity and the irregular shape of the bottom ash particle has great influence on workability and viscosity of the fresh concete. The compressive strength and water absorption test are carried out on the sample at curing time of 7 and 28days. In terms of strength, the use of bottom ash in the production of SCC has increased the compressive strength of the concrete up to 15% replacement level. The increase in strength show the presence of the pozzolanic reactivity in a concrete with bottom ash particle. The water absorption rate was observed to be lower with a sample which having 10% and 15% replacement level.
Preparation of Palm Oil Fuel Ash Composite as Green Pigment
Authors: Kiong Sia Chee , Mohd Nor Syarul Hakimi , Ong Pauline , Ng Wei Ming
Published: October 2014

In this work, the potential beneficial uses of palm oil fly ash (POFA) as a green pigment in paint technology via sintering process was studied. The POFA composites were sintered in the furnace at temperature 750°C. The obtained green pigment from POFA composites through the processes of mixing, reductive heating, ball milling and sieving was subsequently characterized by X-Ray diffraction technique.
Viscosity Analysis of Copper Powder Mixed with Palm Stearin Based Binder
Authors: Nordin Nor Amalina , Rabzi Izyan , Wahab Nor‘aini , Jumahat Aidah , Ismail Muhammad Hussain
Published: October 2014

In this experimental work, the viscosity of copper powder mixed with developed binder system based on palm stearin were studied and analyzed by means of rheological test. The feedstock is limited to 65 vol% of copper powder and 35 vol% of binder system; each of which consists of palm stearin (PS) and polyethylene (PE) prepared in four distinct formulations; 50 wt.% PS, 60 wt.% PS, 70 wt.% PS and 80 wt.% PS. Both copper powder and binder system were initially mixed to produce four sets of homogeneous feedstock. The rheological characterizations of the feedstock which includes its viscosity, pseudo-plasticity, shear sensitivity index (n), and yield stress were analyzed by using Rosand RH2000 Capillary Rheometer at a temperature of 150°C. Finally, the moulded parts were immersed in the n-heptane solution for 7 hours. The morphology analysis by Scanning Electron Microscope (SEM) by means of Hitachi SU 3500 Scanning Electron Microscope were carried out at the end of every stage. The study has shown clearly that PS plays several important roles in the composite binder system.
Evaluations of Mechanical Properties and Residual Strength of Drilled Glass Fiber Reinforced Polymer (GFRP) Composites
Authors: M.M.Wong Irina , Tan Chye Lih , Azmi Azwan Iskandar , Leong K.W. , Mohd Radzi Muhammad Nazri
Published: October 2014

This paper investigates the mechanical properties of drilled and non-drilled glass fiber reinforced polymer (GFRP) composites of plain woven and stitch bi-axial ±45° fabrics. Vacuum-assisted resin transfer moulding was employed to fabricate the composite panels. In the first stage of this study, mechanical properties such as tensile strength, flexural strength, and volume fraction of the composites were determined by per ASTM standards. Later on, the fabricated GFRP composites were drilled in order to investigate the delamination damage. Based on this issue, residual strength was evaluated after drilling process using constant feed rate and spindle speed but different drill bit geometries, which include twist drill bit and step drill bit. Experimental results showed that plain woven performed better in term of mechanical properties and residual strength after drilling process. In addition, residual strengths of drilled composites using step drill bit exhibited superior performance than that of the twist drill.
Impact of Alkali Treatment Conditions on Kenaf Fiber Polyester Composite Tensile Strength
Authors: Hashim Mohd Yussni , Roslan Mohd Nazrul , Mahzan Shahruddin , Zin Mohd , Ariffin Saparudin
Published: October 2014

The increase of environmental issues awareness has accelerated the utilization of renewable resources like plant fiber to be used as reinforced material in polymer composite. However, there are significant problems of compatibility between the fiber and the matrix due to weakness in the interfacial adhesion of the natural fiber with the synthetic matrices. One of the solutions to overcome this problem is using chemical modification like alkali treatment. In this study, the impact of alkali treatment conditions on short randomly oriented kenaf fiber reinforced polyester matrix composite tensile strength was investigated. The experimental design setting was based on 2 level factorial experiments. Two parameters were selected during alkali treatment process which are kenaf fiber immersion duration (at 30 minute and 480 minute) and alkali solution temperature (at 40°C and 80°C). Alkali concentration was fixed at 2% (w/v) and the kenaf polyester volume fraction ratio was 10:90. The composite specimens were tested to determine the tensile properties according to ASTM D638-10 Type I. JOEL scanning electron microscopy (SEM) was used to study the microstructure of the material. The result showed that alkali treatment conditions setting do have the impact on tensile strength of short randomly oriented kenaf polyester composite. The interaction factors between immersion time and temperature was found to have prominent factors to the tensile strength of composite followed by the immersion time factor.
Identification of Methyl Ester Content from Waste Cooking Oil Using Gas Chromatographic Method
Authors: Abdullah Nor Hazwani , Hassan Sulaiman
Published: October 2014

Waste cooking oil has always been an environment problem in food factories and one method of effect disposing this oil without effecting the environment is to convert it to fatty acid methyl ester (FAME) using small scale pilot plant. The conversion of waste cooking oil with sodium hydroxide as a catalyst in conversional process at 22kHz speed. The reaction of time, molar ratio, speed, catalyst and amount of catalyst will be effect in FAME quality. The quality of biodiesel define is total ester content using gas chromatography. Gas chromatography analysis is a one of technique for identification and quantitation of compounds in a biodiesel sample. From biodiesel sample can identification of contaminants and fatty acid methyl ester. In this research biodiesel sample were analyses using a gas chromatography-flame ionization detector ( Perkin Elmer GC Model Clarus 500) equipped with a DB-5 HT capillary column ( 0.53mm x 5 m) J&W Scientific. The analytic conditions for ester content were as follow by: column temperature used 2100C, temperature flame ionization detector (FID) of 2500C, pressure of 80kPa, flow carrier gas of 1ml/min, temperature injector of 2500C, split flow rate of 50ml/min, time for analysis 20 minute and volume injected of 1 μl. The ester content (C), expresses as a mass fraction in present using formula (EN 14103, 2003a) calculation. Conversion of triglyceride (TG) to FAME using conversional process obtained 96.54 % w.t with methanol to oil molar ratio 6:1, 1%w.t acid sulphuric and 1% w.t sodium hydroxide catalyst.
Application of Molasses as a Binder in Sand Mold Operation
Authors: Ibrahim Bashir , Tijjani Y. , Rafukka I.A. , Suleiman M.U.
Published: October 2014

The application of molasses as a binder in sand mold operation was investigated. Standard Sand Mold mixture (5 cm diameter x 5 cm height) were made with 1-5% molasses and Chalawa sand the balance. The molding Properties such as ; Green Compressive Strength(GCS), Green Shear Strength(GSS), Dry Compressive Strength(DCS), Dry Shear Strength(DSS), Green Shatter Index, Green Permeability, Flowability, and Compactibility of sand molasses mixture were obtained. 2% Molasses-sand mixture was selected for molding the prototype cast based on the highest values of the Green Compressive Strength, Green Permeability, and excellent Flowability (96.4%) observed in the experiments. The result shows that molasses alone could not be used as a binder. This is further supported by the low values of Green Shatter Index (31.3%) and Compactibility (25%) reported.
Optimizing Pulsed Current Micro Plasma Arc Welding Parameters to Maximize Ultimate Tensile Strength of AISI 304L Sheets Using Response Surface Method
Authors: Siva Prasad Kondapalli , Srinivasa Rao Chalamalasetti , Nageswara Rao Damera
Published: October 2014

AISI 304L is an austenitic Chromium-Nickel stainless steel offering the optimum combination of corrosion resistance, strength and ductility. These attributes make it a favorite for many mechanical components. The paper focuses on developing mathematical model to predict ultimate tensile strength of pulsed current micro plasma arc welded AISI 304L joints. Four factors, five level, central composite rotatable design matrix is used to optimize the number of experiments. The mathematical model has been developed by response surface method. The adequacy of the model is checked by ANOVA technique. By using the developed mathematical model, ultimate tensile strength of the joints can be predicted with 99% confidence level. Contour plots are drawn to study the interaction effect of pulsed current micro plasma arc welding parameters ultimate tensile strength of AISI 304L steel. The developed mathematical model has been optimized using Response Surface Method to maximize the ultimate tensile strength.
Mathematical Modeling for the Prediction of Depth of Penetration in Double Pulse GMA Welding Using Fractional Factorial Method
Authors: Manikya Kanti K. , Pedapati Srinivasa Rao , Ranga Janardhana Ginka , Rani A.M.A.
Published: October 2014

The quality of weld joint is directly influenced by the input process parameters influenced by various process parameters during welding. The weld quality can be decided by bead geometry viz., depth of penetration and bead width. Inadequate depth of penetration will lead to failure of the welded structure. This paper presents the development of mathematical model for the prediction of depth of penetration of weld bead geometry in pulsed gas metal arc welding process in double pulse mode. The model is based on experimental data .In this investigation four input process parameters wire feed rate, ratio of wire feed rate to travel speed, amplitude and double pulse frequency are considered. The experiments were conducted on 6mm thickness plate of 5083 H111 aluminum alloy using fractional factorial design of experiments. The mathematical model for depth of penetration is developed using multiple nonlinear regression. The developed model is then compared with experimental results and it is found that the results obtained from mathematical model are accurate. The obtained results help in selecting quickly the process parameters to achieve the desired quality.
The Effect of Adding Additives on the Mixture of 80% Methanol 96% 20% Ethanol 10% as a Renewable Fuel to Kerosene Substitute
Authors: Astanto Jarot Hari , Himawanto Dwi Aris , Tjahjana D. Danardono Dwi Prija , Astuti Dwi
Published: October 2014

This research aims to obtain the effect of adding additives on the mixture of 80% methanol (96%) 20% ethanol (10%) that is based on the combustion characteristics as shown by the spaces: specific gravity at 60/60oF, heating value, flash point, kinetic viscosity at 40°C and the specific heat Cp. The method used to determine the effect of adding additives on the mixture of 80% methanol (96%) 20% ethanol (10%) is water boiling test (WBT) start cold and laboratory testing which includes heating value test, specific gravity test, kinetic viscosity test, flash point test. The results showed that the mixture of 80% methanol (96%) 20% ethanol (10%) with the addition of 33.4 ml (500 ml/60 liters of fuel) of additives Top One Power Booster get the temperature of the flame burning at the base is 479°C, the temperature of the flame burning in the middle is 383°C, boiling time (97°C) 1 kg of water is 3 minutes 22 second, fuel consumption is 90 ml, found puddles on kaviti 0.25 ml. It can be concluded that the additives Top One Octane Booster OB-4.5 in the form of caplets/solid containing heavy metals Pb (lead) so it does not dissolve in a mixture of 80% methanol (96%) 20% ethanol (10%), the addition of 33.4 ml of additive Top One Power Booster in a mixture of 80% methanol (95%) 20% ethanol (10%) to increase the heating value, the kinetic viscosity, specific heat and degrade the specific gravity, density and flash point.
Exhaust Emission Reduction of Diesel Engine Fueled with Emulsified Palm Oil Methyl Esters
Authors: Aziz Amir Bin , Siong Wong Chung , Mamat Rizalman , Hagos Ftwi Yohaness
Published: October 2014

An emulsion fuels is one of an alternative method that have been used to reduce exhaust emission from diesel engine. However, there were still not properly explored on the emulsified biodiesel. In this work, the effects of water concentration in palm oil diesel emulsions (POD) [POD is palm oil Methyl esters] on exhaust emissions of a 4-cylinder diesel engine were investigated. The engine speed was set at 2500 rpm and loads at 20, 40 and 60 %. Emulsions were prepared using ultrasound method by mixing POD fuel with 5, 10 and 20 % of water by volume. Results of exhaust emissions for POD and their emulsion were compared with OD fuel. The experimental results show that, the increasing water concentration in POD decrease the NOx and PM simultaneously. POD emulsions is a promising alternative fuels for reducing emissions from diesel engines without any engine modifications.
Predicting the Performance and Emissions Characteristics of a Medium Duty Engine Retrofitted with Compressed Natural Gas System Using 1-Dimensional Software
Authors: Alimin Ahmad Jais , Ismail Muhammad Yusri , Osman Shahrul Azmir
Published: October 2014

The rise of crude oil price and the implications of exhaust emissions to the environment from combustion application call for a new reliable alternative fuel. A potential alternative fuel for compression ignition (C.I.) engine is the compressed natural gas (CNG). For C.I. engines to operate using CNG, or to be converted as a retrofitted CNG engine, further modifications are required. Previous works reported loss in brake power (BP) and increase in hydrocarbon (HC) emission for C.I. engine retrofitted with CNG fuelling. Verification of performance characteristics for CNG retrofitted engine through experimental analysis requires high cost and is very time consuming. Thus, a 1-Dimensional simulation software, GT-Power, was introduced in this study to reduce the experimental process and setup. A 4-cylinder medium duty C.I. engine (DE) and CNG retrofitted engine (RE) GT-Power models were used in this simulation work over various operational conditions: low, medium and high load conditions. As compared with DE model, results from RE model showed that RE model achieved an average 4.9% improvement for brake specific fuel consumption (BSFC) and loss in BP by 37.3%. For nitrogen oxides (NOX) and carbon dioxides (CO2) RE model predicted reduction of 48.1% (engine mode 1-9) and 33.4% (all engine modes), respectively. Moreover, RE produced 72.4% more carbon monoxide (CO) and 90.3% more HC emission.
Stability and Takeoff Ground Roll Issues of Hybrid Buoyant Aircraft
Authors: Ul Haque Anwar , Asrar Waqar , Omar Ashraf Ali , Sulaeman Erwin , Mohamed Ali Jaffar S.
Published: October 2014

In the field of aviation it is well known that a vehicle’s stability and takeoff flight segment are critical. This issue becomes more critical for a hybrid aircraft which is concealed as an airship with huge volume of hull as compared with fuselage of a conventional aircraft. In the present work, stability issues of a generic model of airship and of a conceptual model of hybrid aircraft are discussed. Special emphasis is given for future sizing of empennages of IWHA-14, a hybrid aircraft concept proposed for Malaysian inter island transportation. Effect of gondola position on rotation angle for takeoff ground roll was analyzed and it was found that such configurations can meet the requirement of minimum roll angle.
Vibration Response on MiNT-SRC Building due to Ground Borne Vibrations from Humans Using Finite Element Modeling
Authors: Tuan Chik Tuan Norhayati , Ahyer Muhammad Zarrin , Yusoff Nor Azizi , Ilias Mohd Ezwan , Wan Ibrahim Mohd Haziman , Ghazali Mohd Imran
Published: October 2014

Building structure is naturally exposed to the vibration phenomenon. Vibration in high amplitude may causes big damages to the building structure, while the lower amplitude of vibrations is not causes big effect to the building but it may produce low vibration response to floor structure that can disturbance people comfort and equipment workability. In this study, the vibration response is focusing on low amplitude of vibrations from the ground which due to human activity like footstep or walking. Human activity such as walking will produce low vibration amplitude that can affect the sensitivity of sensitive equipment inside the research or laboratories facilities. Microelectronic and Nanotechnology-Shamsuddin Research Center (MiNT-SRC) building at UTHM is selected to be a location for ground borne vibration measurement due to human activities. The research center is chosen due to sensitivity equipment in the building that prone to vibration effect. Finite element modelling is the method been used to analysed the vibration response distribution to overall building. Vibration data input from field measurement is analysed in ANSYS software based on finite element method, and then further analysis in MATLAB software. A ModalV analysis program in MATLAB is used to produce one third octave velocity spectra and vibration criterion curve for the studied floor. The study shows that the vibration criterion for MiNT-SRC building is classified as VC-E at ground floor and VC-B at the first floor. Thus, based on the result analysis, the sensitive equipment is most suitable to locate at the ground floor of MiNT-SRC building.
Physical and Sound Absorption Properties of Spent Tea Leaf Fiber Filled Polyurethane Foam Composite
Authors: Ahsan Qumrul , Ching Chia Pooi , bin Yaakob Mohd Yuhazri
Published: October 2014

Spent tea leaves (STL) from tea producing factories can be considered as new resources for sound absorbing polyurethane (PU) matrix composite materials because STL are rich in polyphenols (tannins) which cause high durability, high resistance to fungal and termites, and high resistance to fire. The research aims to study the physical characteristics of STL and the effect of dispersion morphology of STL on the sound absorption properties of polyurethane foam composites by varying filler loading. Three grades of STL fibers either as received or granulated are used in this study, namely BM-FAE and SWBHE derived from the stalk while FIBER-FAE derived from the leaves of the tea plant. The PU/STL composites are fabricated through open molding method with a fiber loading of 16 wt. %. The fabricated composites are then subjected to physical and sound absorption testing as well as microscopic observations to analyze the distribution of filler in composite. The study shows that as-received FIBER-FAE spent tea leaves provide the best sound absorption coefficient and for composites using granulated fibers from any grade have lower sound absorption coefficient. These results show that a novel kind of sound absorption materials with the recycling of waste materials can be obtained for the solution of noise and environmental pollution.
The Effects of Spot Weld Pitch to the Axial Crushing Characteristics of Top-Hat Crash Box
Authors: Dimas Agustinus , Dirgantara Tatacipta , Gunawan Leonardo , Jusuf Annisa , Putra Ichsan Setya
Published: October 2014

Numerical study of the effect of spot weld pitch with respect to top-hat crash box crushing characteristics are presented in this paper. Belytschko-Lin-Tsay shell element was used for modeled columns wall with Piecewise Linear Plasticity material model. The impactor was modeled using hexahedral solid elements and assumed as a rigid body. Spot weld joints used to connect mild steel St37 plates of the columns were modeled using beam element and solid element. Impact characteristics related to the spot weld pitch and models were evaluated from simulation results in the form of crushing force vs axial deformation of the column. The results show that spot weld pitch does not significantly affect the crushing characteristics for top-hat crash box with beam element spot weld model, while solid element spot weld model show otherwise. The difference between beam element spot weld model and solid element spot weld model is larger at spot weld pitch 0.50H – H, and tend to close at higher spot weld pitch. Top-hat crash box model becomes stiffer with solid element applied as spot weld model.
Impact Behavior of Square Crash Box Structures Having Holes at Corners
Authors: Chanh Nghia Nguyen , Dirgantara Tatacipta , Santosa Sigit P. , Jusuf Annisa , Putra Ichsan Setya
Published: October 2014

In this paper, an analytical prediction and numerical simulation of the behavior of square crash box structures having hole at corners on dynamic axial crushing are studied. The focus of the present theoretical prediction is to calculate the mean crushing force and maximum crushing force during the folding process subjected to axial impact loading. Then, the effect of hole size to the crushing response of square crash box structures was also evaluated. For validation, an explicit non-linear commercial finite element code LS-DYNA was used to predict the response of the structures subjected to axial crushing. It was found that results of numerical method and theoretical prediction were in good agreement. The results showed that, by inserting holes at corners, the folding can be controlled to be always started from the hole, and peak crush load on the first fold can be reduced significantly. Meanwhile, the decreasing of mean crushing force is insignificant compared to the one without holes. Hence, the characteristic of impact energy absorption in a progressive buckling can be improved, the damage in passenger compartment can be minimized, and the deceleration level can be kept in safe level to prevent injury of the passenger.