bluuebunny/crossref_metadata_2025_split huggingface dataset:
EFFECT OF PH TOWARDS HYDROGEN GAS OUTPUT OF A SMALL AND PORTABLE ALKALINE ELECTROLYSER
Authors: Zakaria Muhammad Zulfattah , Saaduna Mohd Noor Asril , Idris Norain , Haminudin Nor Faizah , Abdollah Mohd Fadzli , Ahmad Emy Zairah 
Published: October 2015

Experiments have been conducted to test the hydrogen gas output of a small and portable alkaline electrolyser, a device which converts electricity into hydrogen and oxygen gases via electrolysis process. This cell will be mounted on a vehicle with 12VDC electricity system to supply hydrogen gas to the air intake which will react as a fuel catalyst to enhance combustion and emission while the oxygen will be released back to the atmosphere. The small cell is made of 16 stainless steel plates type SS316 with size of 15 cm x 10 cm x 0.06 cm and the electrolyte is made of distilled water mixed with potassium hydroxide. The aim of this study was to obtain optimal pH level for the electrolyte. Result showed that the hydrogen gas output started to increase when the pH of the electrolyte approached pH14. Almost zero gas production wasrecorded at pH below 13.5. However, by increasing the amount of potassium hydroxide even when the pH was already 14 showed increased amount of gas released. The same result was recorded for distilled water and reverse osmosis water (RO for drinking).
ENERGY ANALYSIS FOR LIGHTING AND AIR-CONDITIONING SYSTEM OF AN ACADEMIC BUILDING
Authors: Boon Tuan Tee , Yahaya Ahmad Zubair , Breesam Younus Fahad , Mat Dan Reduan , Zakaria Muhammad Zulfattah 
Published: October 2015

Energy analysis is important to analyze energy consumption pattern, monitoring on how the energy used varies with time in the building and how the system element interrelate. In this case study, a preliminary energy audit is done on lighting and air-conditioning system. The lighting and airconditioning system consume the highest amount from the total building energy usage. The study was conducted in the Faculty of Mechanical Engineering Building, Universiti Teknikal Malaysia (UTeM) Technology Campus. From the result shows that the air-conditioning system has contributed approximately 48.8% from the total monthly energy usage. The estimation of Building Energy Index (BEI) for the cooling load is 655.19 kWh/m²/year. Meanwhile, the BEI for lighting system is found approximately 150 kWh/m2/year.
KENAF AS MATERIAL FOR LABORATORY TABLETOP
Authors: Salleh Zuraidah , Yunus Syarifah , Berhan Mohamad Nor , Mei Hyie Koay , Kalam Anizah , Nik Masdek Nik Rozlin 
Published: October 2015

Nowadays, kenaf are gaining attention in the development and is used in many types of engineering application. This new type of composite also contribute towards the green technology making it favorable in various applications. This research is focused on making a laboratory tabletop by utilizing the unidirectional oriented kenaf fiber as the main material which is layered with woven fiberglass. The project methodology is divided into three sections; preparing the specimen, conducting the experiment and testing as well as data analysis. The mould that contains a layer of woven fiberglass and kenaf fiber were poured from a mixture of polyester resin and polyester hardener. The specimen was then compressed and left to dry completely before further testing. Tensile test was carried out by following the ASTM D3039, ASTM D7264 standard for flexural test and ASTM D7136 for drop weight impact test. The results data obtained was found to be suitable for lightweight use only.
EFFECT OF HYBRIDIZATION ON OPEN-HOLE TENSION PROPERTIES OF WOVEN KEVLAR/GLASS FIBER HYBRID COMPOSITE LAMINATES
Authors: Shaari Norazean , Jumahat Aidah , Abdullah Shahrul Azam , Hadderi Ahmad Zariff 
Published: October 2015

Hybrid laminates consisting of woven Kevlar/glass fiber composite plies were studied in terms of their residual tensile strength, stiffness and fracture surface. Residual tensile strength and stiffness were determined from the open hole tension test according to ASTM D5766. The laminates of Kevlar fiber reinforced polymer (KFRP), glass fiber reinforced polymer (GFRP) and hybrid of Kevlar-glass fiber reinforced polymer (KGFRP) were fabricated using a vacuum bagging process. Three different ratios of Kevlar to glass fiber plies were prepared in this study which were 20:80, 50:50, and 80:20. Results showed that hybrid laminate consisting of 80:20 Kevlar to glass fiber plies, produced higher residual tensile strength and stiffness when compared to the other hybrid system. Furthermore, strength and stiffness of hole specimens were reduced within 50-63% when compared to unhole specimens due to existence of the hole. In addition, the effect of adding nanosilica to the hybrid system was also studied. 5 wt% of nanosilica was added to the hybrid composite laminates and results showed that higher tensile strength and stiffness was observed in GFRP and 20:80 KGFRP specimens, while the tensile strength was decreased with an increased number of Kevlar fiber. This research was conducted as there are limited number of studies that have been done on the tensile strength of woven hybrid composite laminates so far, especially on hybridization of Kevlar and glass fiber with consideration on the effect of hole and addition of nanofillers.
BEHAVIOR OF IMPLANT STABILITY DURING IMPLANT TREATMENT: IN VIVO STUDY
Authors: Genisa Maya , Rajion Zainul Ahmad , Shuib Solehuddin , Pohchi Abdullah , Mohamad Dasmawati 
Published: October 2015

Implant stability is essential parameters that indicate the success of the implant treatment. However, the relation between implant stability, osseointegration and also remodeling process during that period is still unclear. This study was to evaluate the behavior of implant stability during implant treatment period.To investigate the behavior of the implant stability and its relation with quality and quantity of the bone during implant treatment, eight dental implant patients have been involved. Series of monitoring stages were conducted. The implant stability for each stage were measured using Resonance Frequency Analysis (RFA) devise and the behavior of quality and quantity of the bone during treatment have been monitored by using CBCT data. The phases of monitoring are divided into 3 phases; phase 1 is immediately after implant insertion, phase 2 is immediately after crown installation (4 month after implant insertion), and phase 3 is 1 month after crown installation (5 month after implant insertion). The results were tabulated and analyzed using statistical software namely SPSS 20.5 to examine the correlation between basic measurement of bone quality and quantity and ISQ. The results show that during 4 month after implant insertion period, the density of bone around the implant are decrease, this period was predicted as remodeling process. After 5 moth since implant insertion, the density start to increase. This phase possibly indicated the starting phase of osseointegration process. In addition, the ISQ for each patient was increased significantly. The primary implant stability was correlated with the space availability and bone quantity and quality, the result shows that the implant stability is proportional with the height of the mandibular and cortical thickness and inversely with width of mandibular. The highest correlation with the primary implant stability is the product of cortical thickness with the height of mandibular. There is a significant correlation between implant stability (ISQ) with dimension of site implant and density of bone.
FULL-AND REDUCED- ORDER COMPENSATOR FOR INNOSAT ATTITUDE CONTROL
Authors: Hashim Fadzilah , Mashor Mohd Yusoff , Sharun Siti Maryam 
Published: October 2015

This paper presents a study on the estimator based on Linear Quadratic Regulator (LQR) control scheme for Innovative Satellite (InnoSAT). By using LQR control scheme, the controller and the estimator has been derived for state space form in all three axes to stabilize the system’s performance. This study starts by converting the transfer functions of attitude control into state space form. Then, the step continues by finding the best value of weighting matrices of LQR in order to obtain the best value of controller gain, K. After that, the best value of L is obtained for the estimator gain. The value of K and L is combined in forming full order compensator and in the same time the reduced order compensator is also formed. Lastly, the performance of full order compensator is compared to reduced order compensator. From the simulation, results indicate that both types of estimators have presented good stability and tracking performance. However, reduced order estimator has simpler equation and faster convergence to zero than the full order estimator. This property is very important in developing a satellite attitude control for real-time implementation.
EFFECT OF NANOSILICA CONTENT ON LONGITUDINAL AND TRANSVERSE TENSILE PROPERTIES OF UNIDIRECTIONAL KENAF COMPOSITE
Authors: Manap Norhashidah , Jumahat Aidah , Sapiai Napisah 
Published: October 2015

Nowadays, continuous natural fibre reinforced polymer nanocomposites have attracted substantial attention among researchers due to various benefits possesses by the natural fibres. Kenaf fibre has become one of the high potential candidates to replace synthetic fibres in polymer composite. Kenaf fibre exhibits good strength and modulus properties, low density, non-abrasive during processing and biodegradable. This study is aimed to evaluate the effect of nanosilica on longitudinal and transverse tensile properties of unidirectional (UD) kenaf composite. The UD kenaf composite samples were prepared based on three different nanosilica content; i.e. 5, 13 and 25 wt.%. The samples were prepared using filament winding and vacuum bagging techniques. The 0o and 90o tensile tests were conducted in accordance to ASTM standard D3039 in order to obtain longitudinal and transverse tensile properties of unmodified and nanosilica-modified kenaf composites. The fracture surfaces of the specimens were observed using scanning electron microscope in order to identify fracture mechanisms involved during tension. The results showed that the addition of nanosilica reduced longitudinal tensile Young’s modulus, strength and failure strain of the kenaf composite. SEM micrographs revealed incomplete resin wetting and fibre pull-out mechanism at high nanosilica content that contributed to premature failure of the kenaf composites. However, it was found that the addition of nanosilica improved transverse tensile properties of kenaf composites since these properties were mostly governed by the properties of the matrix. A stiffer matrix improved the transverse tensile modulus and strength of kenaf composites.
Peak Accelerations of Equipment Within a Bundle Towhead During Pile Driving Operations
Authors: Roberts Graeme , Sriskandarajah T. , Arosio Umberto , McDonald Nick , Pingen Dirk , Rajaratnam Sabesan 
Published: October 2015

Pipeline bundles are towed to site between towhead manifold structures which are designed to contain all the manifold valve-work and control equipment. The towhead is a space frame that not only supports and protects the on-board equipment during service but also allows the attachment of temporary buoyancy units that are necessary for the towing and controlled ballasting operations during installation.
Pre-installed equipment within the towhead space-frame must be operable following the bundle on-shore transportation, launch, offshore tow and pile driving operations that are necessary to secure some towheads to the seabed.
The analysis work reported in this paper focuses on pile driving activities and was carried out to demonstrate that forced acceleration of pre-installed equipment, caused by transmission of pile driving energy to the towhead, did not exceed the equipment’s recommended allowable shock limits.
The desired outcome of the analyses was an understanding that equipment pre-installation offered an acceptable design solution for a particular towhead configuration founded on a soft silty clay soil in the North Sea and that this outcome would be applicable to future similar towheads.
Fatigue Crack Growth Rate of Reeled Pipe in Sour Environments
Authors: Safari Javad , Thodla Ramgopal , Merchant Ian , Hamilton John 
Published: October 2015

Fatigue Crack Growth Rate (FCGR) of reeled pipe (strained & aged) in sour environments was investigated. FCGR frequency scans on different microstructures, i.e. heat affected zone (HAZ), and weld center line (WCL), revealed that, FCGR in corrosive environments increased with decreasing frequency and reached a plateau value at low frequencies of 10mHz to 3mHz. At these ‘plateau frequencies’, FCGR in the moderately sour environment that was investigated were found to be about 10–18× or 30× higher than the in-air values for the WCL and HAZ, respectively. There was no effect of the reeling cycles on the FCGR of the WCL or HAZ specimens. The FCGRs of the WCL were consistently lower than that of the HAZ by about a factor of 2–3× under various conditions. The reason for the lower FCGR of the WCL is not well understood. It is possible that it may be due to the higher yield strength (YS) of the overmatched welds, differing hydrogen concentration and/or diffusion coefficient or possibly due to the differences in the microstructure between the HAZ and WCL.
Paris law curves, FCGRs as a function of ΔK (stress intensity factor range), were measured on the HAZ, and WCL (both intrados) at the plateau frequency (10mHz), representative of flowline cyclic loading. They were also measured at a higher frequency of 0.33Hz, representative of Steel Catenary Risers (SCR) cyclic loading associated with wave motion. Comparisons of measured Paris law curves in corrosive environments to those in air were consistent with the results of the frequency scans. There was no effect of number of cycles of reeling on the Paris law curves in the sour environment tested for WCL and HAZ specimens at both the plateau frequency and 0.33Hz.
The results of the test program suggest FCGR of WCL and HAZ in the sour environment tested are not affected by number of cycles (up to 5) of straining on the intrados side for the strain level (1.93% per cycle) used in this study.
Analysis of Impact Loads on a Self-Elevating Unit During Jacking Operation
Authors: Ringsberg Jonas W. , Daun Viktor , Olsson Fredrik 
Published: October 2015

The renewable energy resource of offshore wind is believed to have a great potential in playing an essential role on the future energy market in Europe, but there are complications such as harsh weather and low accessibility. To manage this, most offshore wind turbines of today are installed and maintained using self-elevating units (SEUs). In this study, a method is presented that enables the analysis of weather window assessments for the installation and retrieval phases of a SEU. The method of analysis takes site-specific parameters, defined as soil type and water depth, into account in addition to vessel-specific and environmental parameters. The inclusion of site-specific parameters is the novel contribution compared to assessment methodologies used today.
A simulation model is presented that incorporates a coupled non-linear time-domain analysis of vessel motion and soil-structure interaction. Soil deformation behaviour during impact is described by resistance curves based on a bearing capacity theory. A structural evaluation criterion against which impact forces are compared is used for weather window assessments. The simulation model is applied on a case study utilizing different soil types to study impact forces and the capacity of the structure for withstanding such impacts and eventually performing a weather window assessment.
The results show that the jacking operation can be divided into two phases when it comes to loads on the spudcan: a phase dominated by vertical forces followed by a phase dominated by horizontal forces. It is found that including soil deformation behaviour is of paramount importance to the magnitude of the resulting impact forces and that class-recommended practice does indeed produce rather large force estimates. Thus, assessments where site-specific parameters are incorporated could definitely increase the operable weather window for SEUs, and, consequently, increase the economic competitiveness of, for example, the offshore wind industry.
Parameterization of a Multi-Directional Tidal Turbine Performance Using Computational Fluid Dynamics
Authors: Medvitz Richard B. , Jonson Michael L. , Dreyer James J. , McEntee Jarlath 
Published: October 2015

High resolution RANS CFD analysis is performed to support the design and development of the Ocean Renewable Power Company (ORPC) TidGen™ multi-directional tidal turbine. Two-dimensional and three-dimensional unsteady, moving-mesh CFD is utilized to parameterize the device performance and to provide guidance for device efficiency improvements.
The unsteady CFD analysis was performed using a well validated, naval hydrodynamic CFD solver and implementing dynamic overset meshes to perform the relative motion between geometric components. This dynamic capability along with the turbulence model for the expected massively separated flows was validated against published data of a high angle of attack pitching airfoil.
Two-dimensional analyses were performed to assess both blade shape and operating conditions. The blade shape performance was parameterized on both blade camber and trailing edge thickness. The blades shapes were found to produce nearly the same power generation at the peak efficiency tip speed ratio (TSR), however off-design conditions were found to exhibit a strong dependency on blade shape. Turbine blades with the camber pointing outward radially were found to perform best over the widest range of TSR’s. In addition, a thickened blade trailing edge was found to be superior at the highest TSR’s with little performance degradation at low TSR’s.
Three-dimensional moving mesh analyses were performed on the rotating portion of the full TidGen™ geometry and on a turbine blade stack-up. Partitioning the 3D blades axially showed that no sections reached the idealized 2D performance. The 3D efficiency dropped by approximately 12 percentage points at the peak efficiency TSR. A blade stack-up analysis was performed on the complex 3D/barreled/twisted turbine blade. The analysis first assessed the infinite length blade performance, next end effects were introduced by extruding the 2D foil to the nominal 5.6m length, next barreling was added to the straight foils, and finally twist was added to the foils to reproduce the TidGen™ geometry. The study showed that making the blades a finite length had a large negative impact on the performance, whereas barreling and twisting the foils had only minor impacts. Based on the 3D simulations the largest factor impacting performance in the 3D turbine was a reduction in mass flow through the turbine due to the streamlines being forces outward in the horizontal plane due to the turbine flow resistance. Strategies to mitigate these 3D losses were investigated, including adding flow deflectors on the turbine support structure and stacking multiple turbines in-line.
VolturnUS 1:8: Conclusion of 18-Months of Operation of the First Grid-Connected Floating Wind Turbine Prototype in the Americas
Authors: Viselli Anthony M. , Goupee Andrew J. , Dagher Habib J. , Allen Christopher K. 
Published: October 2015

This paper presents an overview of the successful conclusion of 18 months of testing the first grid-connected floating offshore wind turbine prototype in the Americas. The prototype, called VolturnUS 1:8, was installed off Castine, Maine, USA. The prototype is a 1:8 scale prototype and serves to de-risk the deployment of a full-scale 6MW turbine. VolturnUS utilizes innovations in materials, construction, and deployment technologies such as a concrete semi-submersible hull and an advanced composite tower to reduce the costs of offshore wind. The prototype unit was designed following the American Bureau of Shipping (ABS) “Guide for Building and Classing Floating Offshore Wind Turbine Installations”. Froude scaling was used in designing the 1:8-scale VolturnUS prototype so that the motions of the prototype in the relatively protected site represent those of the full-scale unit in an open site farther offshore. During the past year, a comprehensive instrumentation package monitored key performance characteristics of the platform during operational, extreme, and survival storm conditions. Data collected include: wind speed, turbine power, rotor angular frequency, blade pitch, torque, acceleration; tower bending moment, 6 DOF accelerations at tower top and base, mooring line tensions, and wave elevation at the platform. During the past year the prototype has experienced many environments representative of scaled ABS design conditions including operational wind and sea-states, 50-year sea states and 500-year survival sea states.
This large data set provides a unique view of a near full-scale floating wind turbine subjected to its prescribed environmental conditions. Inspections of the concrete hull following removal provided confirmation of material durability. Marine growth measurements provide data for future design efforts.
Location Targeting for Wave Energy Deployment From an Operation and Maintenance Perspective
Authors: de Andrés Adrián D. , Guanche Raúl , Vidal César , Losada Íñigo J. 
Published: October 2015

When looking for a location for a wave energy converter (WEC) installation, developers usually look for sites with high or very high wave energy resource. From this perspective, countries like Scotland or Ireland have made great effort to include this energy source in their energy mix due to their expected high untapped potential. However, higher resource carries marine operation restrictions. Because of that, the selection of a site for a WEC deployment, the installation, operation and maintenance factors have to be considered from the beginning.
In this work an analysis of the suitable locations for the development of wave energy is performed based on the operation and maintenance (O&M) parameters. This study is performed across the globe coastlines taking the met-ocean climate data from Reguero et al (2011) global reanalysis database (GOW) developed at IH Cantabria.
Firstly, an analysis of the global availability and accessibility levels is performed all around the globe taking different wave height thresholds into account. Seven specific locations (North-West Denmark, West of Ireland, Chile, North of Spain, West Portugal, South-West Australia and North of Scotland) with high interest on wave energy have been further analyzed and compared.
Secondly, the O&M access limits are quantified in terms of the weather windows and the waiting period between available weather windows. A statistical analysis of these parameters is performed within different weather windows lengths (6 h, 12 h and 24 h). The seasonality of these parameters is also analyzed. Finally, a failure analysis will be carried out, simulating the repair operation along the lifecycle of the device for different failure rates and waiting times. The affection of this failure and repair scheme over the power production of a device analyzed previously in Andres et al (2014) will be presented.
In this study, some locations with high resource (Spain, Nova Scotia) lead to medium to high accessibilities/availabilities due to the balance between resource and persistence of the weather conditions. Some locations with high resource such as Chile or Australia resulted inaccessible during very long periods of time due to the persistence of severe conditions and then not very recommended for novel converters with uncertain failure rates.