bluuebunny/crossref_metadata_2025 huggingface dataset:
Models of Adopting Cloud Computing in the E-Government Context: A Review
Authors: Mohammed Fathey , Ibrahim Othman
Published: April 2015

Governments and public sector agencies are continuously looking for ways to improve their services. Therefore, there is a need for restructuring processes and effectively using technology to improve efficiency and effectiveness of the business operations. Cloud computing is one of recent technological trends that support these efforts. It is a new type of sourcing model in which computing services are provided as a utility over the Internet. This paper analyzes the benefits and challenges of cloud computing over e-government systems. It reviews the existing literature on the proposed models of cloud computing adoption in the context of e-government. Further, this paper critically analyzes and classifies these models to different categories.
Motivations for Value Co-creation in Higher Education Institutions Using Online Platforms: Case of Idea Bank
Authors: Hasan Nabil , Abdul Rahman Azizah , Saeed Faisal
Published: April 2015

The involvement of stakeholders in value creation is one of the successful marketing techniques. It helps to introduce a very clear view of understanding the stakeholder’s needs, thought and suggestions. Stakeholder engagement in value creation will highlight the fact that new ideas for developing services or products will help to meet customer’s needs and expectations. Ideation is one of the most important strategies that lead to development of such services, enhancing service quality and innovation. Motivation for generating ideas from stakeholders in Higher Educational Institutions (HEIs) through online interaction platforms is one of the challenges that needs further exploration, because of  human differences in the nature of motivation and mindset. Universiti Teknologi Malaysia (UTM) idea bank online platform is adopted as a case study in this research paper. The main aim of this study is to identify the factors that encourage stakeholders in HEIs to be continuously involved in value co-creation through available online platforms. Interviews with sample of active stakeholders have been conducted using open end questions. In addition, observation on idea bank website and analyzing the archive and website history is considered. The initial results identify three areas of motivations for value co-creation in HEIs: organizational motives, online platform characteristics, individual motives. Results and implications for this case study will help HEIs such as universities achieve better global market positioning, to differentiate themselves among others, and to develop stakeholder’s competencies.
Matrix for Mapping ICT Roles in Small and Medium Enterprises with TRIZ Inventive Principles Based on Redesign Service Types
Authors: Gazem Nadhmi , Abdul Rahman Azizah
Published: April 2015

Information and communications technology (ICT) has a high impact on Small and Medium Enterprises (SMEs) business. It enhances capacity for innovation and adds greater value to services in order to attract more customers and produce greater returns to the company. This paper aims to map the ICT roles for SMEs with the TRIZ 40 inventive principles (IP). The methodology of mapping is based on using Service Redesign Types (SRTs) as bridge to link between the ICT roles and the 40 IP. The results produced a new TRIZ 40 IP matrix with ICT roles that add value to implement the 40 IP to support SRTs. This paper conducted a case study in order to demonstrate the usability of mapping ICT role categories with the 40 IP based on SRTs. The output of this study can enhance the way of thinking of redesigning current services and lead SMEs to consider particular technologies that may improve performing the service.
Quranic Verses Verification using Speech Recognition Techniques
Authors: Mohammed Ammar , Sunar Mohd Shahrizal , Hj Salam Md. Sah
Published: April 2015

Al-Quran is the holy book of Muslims which is written and recited in Arabic language, the language in which it was revealed. Muslims believe that the Quran is neither corrupted nor altered this is mainly due to maintaining its original text. It is forbidden to recite the Quran in any other language apart from Arabic with neither additions nor subtractions. However with the proliferation of technology especially the Internet and social media sites such as Facebook and Twitter, the spread of mistakenly or deliberately distorted audio clips are witnessed regularly. In this regard, it is necessary to preserve the authenticity and integrity of the Quran from all sorts of corruption. This paper describes challenges and solutions for building a successful verification system of the Quran verses online. The paper describes the techniques used to deal with a finite vocabulary how modelling completely in the voice domain for language model and dictionary can avoid some system complexity, and how we built dictionaries, language and acoustic models in the framework.
The Role of Electronic Records Management (ERM) for supporting Decision making Process in Yemeni Higher Professional Education (HPE): A Preliminary Review
Authors: Mukred Muaadh , M. Yusof Zawiyah
Published: April 2015

The importance of information has influenced many organizations especially in developed countries such as UK and USA to invest in their information management budget to ensure their survival and comply with the law requirement of their countries. Information could determine the organizations’ success or failures since the process of decisions making mainly must be based on it. To be of value, information must be recorded. This recorded information which contains evident must be preserved. This is because records are evidence of organizational activities, transactions and decisions. Information embed in records supports business functions and are critical for the assessment of organizational performance. Records carry information created as the product of transactions carried out by organizations. Without reliable records agencies and governments could not manage their resources, its revenue or civil service and also cannot deliver services such as education and healthcare. Yemeni Universities and Community colleges where Higher Professional Education (HPE) is adopted to make full use of information embedded in records in any decision made. Yemen started introducing and implementing the HPE system which offers highly qualified specialists to the labor market with the help and support from Netherland government. The HPE project implemented more than five new outcomes based education (OBE) programs at three institutions namely the Industrial Technical Institute (ITI), Aden Community College and Sana’a Community College (SCC).OBE is a portfolio cantered system and the assessment method is depending on recorded information in the documents disclosed in the portfolio. The evaluation decision is based on the reliable information in the portfolio. It is impossible for an educational organization to function efficiently without proper ERM .However, there is not framework as guidance for managing these electronic records, thus making ERM ineffective and efficient leaving evaluation decisions not persuasive. To assess, evaluate and make decisions successfully Yemen’s HPE system requires a framework for managing its electronic records in order to be relevant and trustworthy for making decisions.
Early Detection of Pipeline Leakage Using Ultrasonic Sensor
Authors: Abdul Rahim Herlina , Abd Hamid Khairulanam , Zainal Abidin Hafilah
Published: April 2015

Pipelines leakage is the main problem faced by industries. The main causes of leakage on pipelines are corrosion, crack and disaster. This problem must be detected early to ensure that maintenance work can be done quickly to prevent pipe bursts, as well as to minimize operational costs. The objective of this research is to review a method for early detection of leakage on pipeline that affect by the changing water level in the pipeline. The method used in this research is ultrasonic sensor that is implanted on the outer surface pipeline.
Hardware Development of Reflection Mode Ultrasonic Tomography System for Monitoring Flaws on Pipeline
Authors: Nordin Norsuhadat , Idroas Mariani , Zakaria Zainal Arifin , Ibrahim M. Nasir
Published: April 2015

The pipeline inspection is a key requirement to maintain structural health and pipeline integrity for oil and gas transportation over countries. Pipe failure is a critical problem that needs to be endured within the operational work. The defects or flaws existence on pipeline surface is one of the most leading factors to pipe failures. A new approach of non-destructive technique is implemented to monitor flaws on pipeline by using reflection-mode ultrasonic tomography system. This paper details on the hardware development of ultrasonic tomography system based on reflection mode detection. The system consists of ultrasonic transceiver sensors mounted circularly and contactless to the pipe surface. The modeling work described the ultrasonic ring configuration, ultrasonic signal behavior, sensors arrangement and image grid estimation. The developed instrumentation system is used to detect external and internal flaws on pipe surface. The results show that the reflection-mode ultrasonic tomography is capable to differentiate flaws detected based on the calculated depth verified from the distance measured and through the reconstructed image.
Image Fusion for Electrodynamics and Optical Dual Mode Tomography System
Authors: Elmajri M. M. , Rahmat M. F. , Ibrahim S. , Mohammed N. F. , Hj Mat Said Seriaznita
Published: April 2015

In this paper, a novel fuzzy fusion method is proposed to combine the images obtained from dual modality (optical and electrodynamics) tomography sensors. The fuzzy rules designed are based on the features of each single mode sensor. Furthermore, the outcome of the proposed method is compared with the two mostly common image fusion methods; principal component analysis (PCA) and discrete wavelet transform (DWT). The fused image results of half flow and full flow solid/gas laboratory phantoms are presented in this paper. Matlab software was used to visualize and analyze the combined images. The results show that the proposed method has produces superior improvement in the quality of fused image for optical and electrodynamics dual mode tomography applications in the case of solid/gas flow.
Non-Destructive Assaying Gold Jewellery Using Dual-Energy Micro-Computed Tomography
Authors: Abdullah Jaafar , Samsudin Abibullah , Omar Nor Laili , Abdul Manan Hafizza
Published: April 2015

Determining the fineness of gold jewelleries remains one of the most challenging tasks in gold trading. The existing technology of gold testing is inadequate, allowing gold counterfeiting worldwide. The most popular non-destructive method for analysis of gold jewelleries is X-ray fluorescence technique. However, the technique is limited to surface only and it is also greatly influenced by matrix effects. In this paper, dual-energy X-ray micro-computed tomography method was proposed to assay gold jewelleries. Experimental results demonstrated that grey values of reconstructed tomographic images in combination with advanced image analysis procedures could be used to detect fake jewelleries. Due to the uniqueness of X-ray absorption, the technique was also capable of identifying different materials in gold jewelleries. Further analysis on sectioned-earrings samples using X-ray diffraction techniques and visual observation confirmed all tomographic findings.
An Overall Review: Modified Asphalt Binder Containing Sasobit in Warm-Mix Asphalt Technology
Authors: Hainin Mohd. Rosli , A. Aziz Md. Maniruzzaman , Feizabadi Shahab Moeini , Putra Jaya Ramadhansyah , Abdul Hassan Norhidayah , Mohd Jakarni Fauzan
Published: April 2015

Increasing emission of greenhouse gases is an environmental issue, and it is a great concern to curb this problem from further harm to the environment. Warm-mix asphalt (WMA) is one of efforts to curb a reduction in the temperature at which asphalt mixes are produced. WMA can reduce the temperature to 100°C and even lower without compromising the performance of asphalt binder. WMA has various benefits such as, reduction of asphalt binder temperature, reduction  in energy consumption and less air pollution. It reduces short-term aging, compacting effort and decreases temperature drop during transportation.  Sasobit is one of  the organic additives of warm mix asphalt. It is used as a binder modifier to produce rut resistant mixtures. It provides the option of reducing fume emissions, saving energy and reducing  production  cycles. Therefore, sasobit is the preferred additive for warm-mix asphalt (WMA). In addition, Complex shear modulus will be determined to find the rutting factor and fatigue factor for the asphalt binder (G*/Sinδ and  G*Sinδ  respectively). The overall  purposes of this study are to determine the importance of using  WMA as a green  pavement and  introducing  sasobit for modifying virgin asphalt binder.
Synthesis of Longitudinal Joint of Flexible Pavement
Authors: Mohd Hasan Mohd Rosli , Porter David , You Zhanping
Published: April 2015

This paper provides a wide range of information related to longitudinal joints of asphalt pavement, such as types of longitudinal joints, performance evaluations, factors of failure, and selection of the best practice in constructing longitudinal joints. Additionally, this synthesis provides an overview of construction methods which are typically used in constructing longitudinal joints, along with guides and approaches implemented by different road builders or authorities to attain a better longitudinal joint. It was found that difficulties during compaction of the asphalt pavement at the center line resulted in poor joint density. This has reduced the performance and durability of pavement that is associated with cracks and degradations due to moisture damage, such as raveling. Results from previous field studies and laboratory evaluations have been summarized to understand the factors of failure of the adjacent joint. The Michigan joint technique was found to be the best method in constructing longitudinal joints of HMA. The cutting wheel and the edge restraining device techniques are also recommended by the asphalt technologists however are dependent on the machine operator to obtain consistent results.
Evaluation of Warm Mix Asphalt Performance with High RAP Content
Authors: Arshad Ahmad Kamil , Ma Kridan Frag Ahmed , Kamaluddin Noor Azreena , Shafie Ekarizan
Published: April 2015

The pavement industry is currently forced to find alternative ways to produce asphaltic concrete with the  dwindling supply of new resources and the spiraling cost of materials. Warm Mix Asphalt (WMA) using reclaimed asphalt pavement (RAP) offers a sustainable solution to the problem by reducing energy requirements for production and the reuse of old pavement materials. The effects of warm mix asphalt additive (Sasobit) on mixes containing different percentages of RAP were investigated in the laboratory. Three different concentrations of RAP (30%, 40% and 50%) with 1.5% Sasobit by weight of binder were added, and Marshall method was used to produce all samples investigated. Two different mixing and compaction temperatures were used, 155°C and 135°C for mixing and 135°C and 120°C  for compaction. The performance of the mixes in terms of stiffness and moisture damage were investigated by carrying out the Indirect Tensile Resilient Modulus Test (ASTM D4123) and moisture susceptibility test (ASTM D 4867). The results obtained showed that there were no substantial differences in volumetric properties, stability and stiffness values of reclaimed mixes than the control mix (conventional hot mix asphalt). In addition, all the mixes investigated achieved the required minimum TSR of 80%. Measured rut depth using the Asphalt Pavement Analyser (APA) device and fatigue cycles to failure using beam specimen indicated that the mixes performed similar to or better than the control mix. The results showed that warm mix asphalt using sasobit-additive and containing high percentages of RAP could be a sustainable alternative to the conventional HMA mix.
Malaysian Transverse Rumble Strips: A Review and Recommendations for Practice
Authors: Othman Mohd Hanifi , Haron Zaiton , Hainin Mohd Rosli , Yahya Khairulzan , Yaacob Haryati , Sanik Mohd Erwan
Published: April 2015

Transverse rumble strips (TRS) is a common choice to reduce vehicle speed and increase driver alertness on roadway. TRS is a series of marked (either flat or raised) transverse bars placed across the road in direction of traffic flow. It functions to assist driver to become aware through optical, vibration and audible effect thus encouraging drivers to reduce speed and increase their alertness in order to face any hazard that may exist ahead. Although often being used, in reality TRS usage in Malaysia still has some aspects that can be improved. The purpose of this paper is to critically review the definition of thermoplastic TRS, its effectiveness, standard guidelines in Malaysia, thermoplastic materials and colour and also to propose the recommendation in regard practice of TRS in order to increase its effectiveness. Besides the available literature source in the light of the latest published findings, personal interview have been done to several authorities which are headquarter and district public work department, local municipal and university regarding TRS application guidelines and practice in Malaysia. The authors synthesize the available findings on the TRS performance and standard guidelines to propose some recommendations for a better application practice of TRS in particular in Malaysia. The proposal of all the findings hopefully would be beneficial to authorities in improving the practices of TRS.
An Overview of Moisture Damage in Asphalt Mixtures
Authors: Hamzah Meor Othman , Kakar Muhammad Rafiq , Hainin Mohd Rosli
Published: April 2015

This paper presents a short review on moisture induced damage in asphalt mixtures. Moisture induced damage is one of the most common causes of pavement distress that results in loss of strength, stripping, raveling, fatigue damage and permanent deformation. Different mechanisms have been used to explain the process of moisture damage in asphalt pavements. However, the moisture damage mechanism takes place due to the interaction of several different processes. The applicability of a single test method to evaluate moisture damage is impractical to a wide range of materials and conditions. Therefore, a new laboratory based testing procedure and analysis protocol is required, with the aim to simultaneously consider the effects of both traffic impact and moisture damage. The proper material design, efficient construction methods, reliable laboratory techniques and well planned highway surface and subsurface drainage systems may lead towards a sustainable asphalt pavement that is sufficiently durable to resist moisture damage. Although considerable advances concerning the subject have been reported, yet there is still a need to address certain issues that are actually involved in the process of asphalt mixture moisture susceptibility.
Applications and Sustainability in Groundwater Abstraction in Malaysia
Authors: Saimy Intan Sazrina , Raji Fauziah
Published: April 2015

Most major cities in Malaysia face problems of clean and safe water supply. The blame is on the population boom, industrialisation, pollution plus climate change. It becomes more complicated with uncontrolled usage, public’s ignorance and ineffective water management. These problems have led to higher dependencies towards alternative usage of groundwater to serve the needs of public, agricultural sector and the industries. Groundwater usage must be abstracted sustainably to avoid short and long term effects. This exploratory qualitative study analyses several aspects: (a) existing documents on Malaysian water management (b) documents on Malaysian groundwater governance; (c) applications and enforcements of groundwater governance in states. The analyses are essential in recognising and providing appropriate and effective groundwater governance towards higher consumption in the country especially in industrial sector. Early finding reveals the current groundwater governance lack good management and there are legal vacuums. This paper promotes appropriate groundwater governance and management of policies and strategies at both federal and state level, relevant agencies, stakeholders and local communities in ensuring sustainable groundwater resources usage in Malaysia.
Stock Market Reaction to Corporate Real Estate Divestitures and Acquisitions during the Global Financial Crisis
Authors: Ping Eng Annie Wong , YM Lee Janice , Mohamed Razali Muhammad Najib , Abdullah @ Mohd Asmoni Mat Naim , Mohammad Izran Sarrazin
Published: April 2015

Real estate divestitures and acquisitions (D&A) are conducted as part of corporate restructuring. This study aims to fill the knowledge gap on abnormal stock market returns (AR) toward D&A activities during the Global Financial Crisis (GFC) in a developing country. Malaysian listed non-real estate companies that conducted D&A during the GFC are used as sample. Event study is applied to determine AR surrounding D&A announcements within (-10day, +10day) event window. Results for both D&A announcements shows insignificant AR on and around announcement date (-1 to +1). For pre-announcement, divesting (acquiring) companies obtain negative (positive) AR, signifying that the market does not favor (favor) divestitures (acquisitions) due to leakage of information. The outcome of post-announcement proves that divesting companies continue to experience negative ARs, although most divesting companies were paid premium prices. However, acquiring companies experience significant and negative post-announcement AR. This is probably due to the price premium which most acquiring companies paid exceeding valuation for their acquisitions. In summary, the market disapproves divestitures in general and acquisitions of real estate assets exceeding their valuations during economic recessions.
An Overview of Green Retrofitting Implementation in Non Residential Existing Buildings
Authors: Jagarajan Rehmaashini , Abdullah @ Mohd Asmoni Mat Naim , YM Lee Janice , Jaafar Mohd Nadzri
Published: April 2015

Sustainability has been the latest value added service in the facility management field. However, the practice of sustainability in the facility management field is not well recognized and understood by the facility management team. As a result, building sector account to be the largest source of greenhouse gas emissions around the world. In fact, there is a strong business case for green building, yet green buildings represent the next phase of buildings. Since, the majority of the existing stock of buildings is not sustainably built and as it is not practically viable to demolish all the existing buildings, hence, one alternate solution is green retrofitting. However, the responses for green retrofitting are at very low rate. This paper reports the need to green retrofitting, reasons behind the limited number of green retrofitting implementation, and finally, a critical review of the existing body of knowledge on green retrofitting has been conducted. It is found that there has been no research conducted till to date on identifying the success factors for successful green retrofitting implementation.
Impacts of Indoor Environmental Quality (IEQ) Elements on Residential Property Market: A Review
Authors: Che Kasim Asmma’ , Megat Abdul Rahman Megat Mohd Ghazali , Mohd Raid Maryanti
Published: April 2015

Indoor environmental quality (IEQ) is among six criteria of Green Building Index (GBI) that need to be achieved by building owner in order to recognize their building as ‘green’ in Malaysia. The benefit of IEQ is to create conducive environment for human health. Besides influenced their overall image, leasing and resale value of the buildings, does indoor environmental quality (IEQ) features will give impact on real estate market in terms of price and rental particularly for residential building property? Therefore, this paper will review the broad literature regarding the impacts of indoor environmental quality (IEQ) for residential building property and its implication to towards property price and rental. The early hypothesis of this paper anticipates that indoor environmental quality (IEQ) features will indirectly increase residential property market price and rental. From this paper, it is hope that the positive impacts of these features will encourage building owners, developers and other main development actors to put these criteria into the same consideration as other criteria in GBI as one of the way to compensate the impact of the building towards economic, environment and social.
Conceptual Design of Malaysia Geopostcode System
Authors: Wan Othman Wan Mohamad Nazmeen , Mohamed Yusof Zainab , Amerudin Shahabuddin
Published: April 2015

The existing postcode hardly works to use in navigation and not precise due to large geographical area coverage. Therefore, development of alphanumeric spatial postcode (geopostcode) conceptual design is very crucial. The hierarchical aggregation of spatial boundaries is used to develop this alphanumeric geopostcode. This eight alphanumeric characters geopostcode can gives a thousand benefits to the users in term of navigation and time consuming. This geopostcode are very important in many sectors in Malaysia especially in Location-Based Services (LBS) application. By implementing of this geopostcode model, the time consuming for searching the address will reduce and increase the preciseness of the location placement. It is can be more flexible, easy to understand, easy to implement and promote data consistency, economic and social developments, governance, public participation and sharing with all participating entities. This new geopostcode hope will achieve greater usability need and to make the postcode as familiar to the person as their telephone number and plate number of their car as well as it is more likely to be memorized.
Spectral Variability Analysis of In-Situ Hyperspectral Remote Sensing at Leaf and Branch Scales for Tree Species at Tropical Urban Forest
Authors: Chew W. C. , Lau A. M. S. , Kanniah K. D. , Idris N. H.
Published: April 2015

Spectral variability analysis has been carried out on in-situ hyperspectral remote sensing data for 20 tree species available in tropical forest in Malaysia. Five different spectral ranges have been tested to evaluate the influence of intra-species spectral variability at specific spectral range given by different spatial scales (i.e. leaf to branch scales). The degree of intra-species spectral variability was not constant among different spectral ranges where the influence of spatial scale towards intra-species spectral variability at these spectral ranges was found increasing from leaf to branch scale. The ratio of leaves to non-photosynthetic tissues has made branch scale significantly influent the intra-species spectral variability. Results have shown that a specific spectral range was species sensitive on the intra-species and inter-species spectral variability in this study. This study also suggested the use of species sensitive wavelengths extracted from specific spectral range in hyperspectral remote sensing data in order to achieve good accuracy in tree species classification.
Effect of Plastic Flattening on the Shearing Response of Metal Asperities: A Dislocation Dynamics Analysis
Authors: Sun Fengwei , Van der Giessen Erik , Nicola Lucia
Published: April 2015

Discrete dislocation (DD) plasticity simulations are carried out to investigate the effect of flattening and shearing of surface asperities. The asperities are chosen to have a rectangular shape to keep the contact area constant. Plasticity is simulated by nucleation, motion, and annihilation of edge dislocations. The results show that plastic flattening of large asperities facilitates subsequent plastic shearing, since it provides dislocations available to glide at lower shear stress than the nucleation strength. The effect of plastic flattening disappears for small asperities, which are harder to be sheared than the large ones, independently of preloading. An effect of asperity spacing is observed with closely spaced asperities being easier to plastically shear than isolated asperities. This effect fades when asperities are very protruding, and therefore plasticity is confined inside the asperities.
Time Scale for Rapid Draining of a Surficial Lake Into the Greenland Ice Sheet
Authors: Rice James R. , Tsai Victor C. , Fernandes Matheus C. , Platt John D.
Published: April 2015

A 2008 report by Das et al. documented the rapid drainage during summer 2006 of a supraglacial lake, of approximately 44×106 m3, into the Greenland ice sheet over a time scale moderately longer than 1 hr. The lake had been instrumented to record the time-dependent fall of water level and the uplift of the ice nearby. Liquid water, denser than ice, was presumed to have descended through the sheet along a crevasse system and spread along the bed as a hydraulic facture. The event led two of the present authors to initiate modeling studies on such natural hydraulic fractures. Building on results of those studies, we attempt to better explain the time evolution of such a drainage event. We find that the estimated time has a strong dependence on how much a pre-existing crack/crevasse system, acting as a feeder channel to the bed, has opened by slow creep prior to the time at which a basal hydraulic fracture nucleates. We quantify the process and identify appropriate parameter ranges, particularly of the average temperature of the ice beneath the lake (important for the slow creep opening of the crevasse). We show that average ice temperatures 5–7  °C below melting allow such rapid drainage on a time scale which agrees well with the 2006 observations.
A Deformation Mechanism for Ridge-Shaped Kink Structure in Layered Solids
Authors: Lei Xiao-Wen , Nakatani Akihiro
Published: April 2015

A deformation mechanism for ridge-shaped kink structure (RSKS), a type of localized deformation, is studied with a discussion focusing on the kink deformation of a monocrystal with a single-slip system under a plane-strain condition. From a geometrical study of displacement continuity it is found that, to satisfy displacement continuity, the kink boundary formed by the deformation from an initially homogeneous structure must have symmetry. We propose a simple model of the RSKS deformation mode to accomplish plastic deformation from a compressive force parallel to the slip direction. First, important geometrical knowledge related to the RSKS formation mechanism is formulated analytically. Then, a simulation of a spring–mass model is performed to clarify the RSKS formation mechanism. The intensity of the angle-dependent force field is found to affect the deformation mode.
A Systematic Method for Design Prototyping
Authors: Camburn Bradley , Dunlap Brock , Gurjar Tanmay , Hamon Christopher , Green Matthew , Jensen Daniel , Crawford Richard , Otto Kevin , Wood Kristin
Published: April 2015

Scientific evaluation of prototyping practices is an emerging field in design research. Prototyping is critical to the success of product development efforts, and yet its implementation in practice is often guided by ad hoc experience. To address this need, we seek to advance the study and development of prototyping principles, techniques, and tools. A method to repeatedly enhance the outcome of prototyping efforts is reported in this paper. The research methodology to develop this method is as follows: (1) systematically identify practices that improve prototyping; (2) synthesize these practices to form a guiding method for designers; and (3) validate that the proposed method encourages best practices and improves performance. Prototyping practices are represented as six key heuristics to guide a designer in planning: how many iterations to pursue, how many unique design concepts to explore in parallel, as well as the use of scaled prototypes, isolated subsystem prototypes, relaxed requirements, and virtual prototypes. The method is correlated, through experimental investigation, with increased application of these best practices and improved design performance outcomes. These observations hold across various design problems studied. This method is novel in providing a systematic approach to prototyping.
Control Aspects of a Compressor Station for Gas Lift
Authors: Saadawi H.
Published: April 2015

The type and characteristics of the control system to be used for a centrifugal compressor station depend on several factors such as the compressor driver, process requirements, and the conditions under which the compressor will be operated. Designing a compressor control system for gas lift applications present different types of problems than those of conventional pipeline applications.

This paper describes the control philosophy of a compressor station used for lifting water in a closed-rotative gas lift installation in Bu Hasa field, Abu Dhabi.
Performance Potential of an Advanced Nuclear Gas Turbine/Cogeneration System (HTGR-GT/C)
Authors: McDonald Colin F. , Van Hagan Thomas H. , Kapich Davorin
Published: April 2015

The success of the closed-cycle gas turbine depends on utilizing high-grade waste heat. This paper presents features for an advanced nuclear gas turbine operating with a reactor outlet temperature of 950°C. It discusses the results of a systems study exploring the performance potential of an advanced nuclear gas turbine/cogeneration concept (HTGR-GT/C) with a high-temperature gas-cooled reactor heat source. It also highlights the flexibility of operation with regard to combined electrical power generation and process steam production.
Combustion of Coal Gas Fuels in a Staged Combustor
Authors: Rosfjord T. J. , McVey J. B. , Sederquist R. A. , Schultz D. F.
Published: April 2015

Gaseous fuels produced from coal resources have been considered for use in industrial gas turbines. Such fuels generally have heating values much lower than the typical gaseous fuel, natural gas; the low heating value could result in unstable or inefficient combustion. Additionally, coal gas fuels may contain ammonia which if oxidized in an uncontrolled manner could result in unacceptable NOx exhaust emission levels. Previous investigations have indicated that staged, rich-lean combustion represents a desirable approach to achieve stable, efficient, low NOx emission operation for coal-derived liquid fuels containing up to 0.8-wt pct nitrogen. An experimental program has been conducted to determine whether this fuel tolerance can be extended to include coal-derived gaseous fuels. The results of tests with three nitrogen-free fuels having heating values of 100, 250, and 350 Btu/scf and a 250 Btu/scf heating value doped to contain 0.7 pct ammonia are presented.
Turbine Deposition Evaluations Using Simplified Tests
Authors: Wenglarz R. A. , Cohn A.
Published: April 2015

Relatively simple and inexpensive tests (compared to cascade and turbine tests) have been utilized in deposition evaluations for alternate ash-bearing turbine fuels. These tests use simple cylindrical specimen geometries and test equipment which have adequately simulated turbine corrosion environments in the past. However, deposition rates on a cylindrical test specimen are not the same as deposition rates for turbine airfoils due to geometry differences. An approach is here described for extrapolating measured deposit buildup rates on cylindrical test specimens to project deposit buildup rates on turbine airfoils and turbine maintenance intervals for deposit removal. Deposition environments are identified for which the data extrapolation approach applies. This approach has provided reasonable deposition assessments for turbine operation with residual oil and coal-derived liquid fuels. Using data from residual oil tests representing current turbine operating conditions, maintenance intervals to remove deposits have been predicted which are in agreement with field experience.
Modifications of the Ives-Liutermoza Conformal-Mapping Procedure for Turbomachinery Cascades
Authors: Rae William J.
Published: April 2015

A conformal mapping technique, applicable to compressor and turbine cascades, is presented. The technique can be used to map the field surrounding the cascade into a rectangle, in which the image of the blade surface lies along one side of the rectangle, the image of the trailing edge is at two corners of the rectangle and the image of downstream infinity lies at the other two corners. These features make it possible to use the mapping in several contemporary flowfield-analysis codes, which carry out their calculations in such a rectangular plane. The mapping produces an O-type grid in the cascade plane.
Post-Test Evaluation of a Prototype Composite Water-Cooled Gas Turbine Nozzle
Authors: Muth M. C. , Beltran A. M.
Published: April 2015

Water-cooled high temperature gas turbine technology has been under investigation by the Gas Turbine Division of the General Electric Company for the past 15 years. The transition from testing small scale laboratory-size hardware to full-scale gas turbine components was initiated in 1975 by General Electric and extended further under the U.S. Department of Energy’s High Temperature Turbine Technology (HTTT) Program. A key element in this transition was the identification of a composite (hybrid) design for the first-stage nozzles. This design permits efficient heat transfer to the water-cooling passage-ways, thus lowering effective strains and increasing part life. The results of GE’s extensive efforts over many years to develop a composite water-cooled first-stage nozzle were further confirmed through the successful fabrication and testing of full-scale hardware under the DOE/HTTT Program.

This paper describes the post test metallurgical evaluation of two segments of the nozzle tested under the DOE/HTTT program. A brief description of the actual hot-gas path testing of the part is given. The bulk of the paper deals with a microstructural evaluation of the segments including microprobe traces and hardness surveys. Pre- and post-test non-destructive evaluations are also reviewed.
Evaluation of Advanced Combustor Concepts for Dry NOx Suppression With Coal-Derived, Gaseous Fuels
Authors: Beebe K. W. , Symonds R. A. , Notardonato J.
Published: April 2015

The projected decline in the availability of petroleum fuels for electricity generation or industrial applications, and the projected increase in an uncertainty of fuel costs throughout the next decade have been driving forces towards the utilization of the nation’s coal resources.
Multifuel Evaluation of Rich/Quench/Lean Combustor
Authors: Novick A. S. , Troth D. L. , Notardonato J.
Published: April 2015

The work described in this paper is a part of the DOE/LeRC “Advanced Conversion Technology Project” (ACT). The program is a multiple contract effort with funding provided by the Department of Energy and Technical Program Management provided by NASA LeRC. The emphasis in this paper is the fuel flexible combustor technology developed under the “Low NOx Heavy Fuel Combustor Concept Program” for application to the Detroit Diesel Allison (DDA) Model 570-K industrial gas turbine engine. The technology, to achieve emission goals, emphasizes dry fuel-bound nitrogen (FBN), control of NOx can be effected through a stated combustor with a rich initial combustion zone. A rich/quench/lean (RQL) variable geometry combustor utilizes the technology that will be presented to achieve low NOx from alternate fuels containing FBN. The results will focus on emissions and durability for multifuel operation.
Condition Monitoring at Bulls Bridge Power Station
Authors: Addrison K. N. , Hill M. L. G.
Published: April 2015

The Station chosen for the trial was Bulls Bridge Gas Turbine Station, sited near London Airport. (See Fig 1-1). Bulls Bridge contains 4, 70 MW sets; each 70 MW unit being powered by 4 Industrial Olympus gas generators, two at either end of a central alternator, (See Fig 1-2). At each end of the alternator, power is supplied via a clutch, to a shaft on which is mounted two power turbines, each driven by a single Olympus gas generator. Thus gas paths are separate between intake and final exhaust, and therefore each gas generator/power turbine assembly can be analysed without being unduly affected by associated plant.
Development of a Low Btu Gas Fuel Cooled Combustor for 3000°F Gas Turbine Operation
Authors: Koblish T. R. , Schaefer R.
Published: April 2015

The attraction of a coal gasification combined cycle system to utility operation lies in its higher efficiencies (pile-to-busbar) relative to competing power generating systems. In order to achieve these higher efficiencies the coal gasification combined cycle combustor/turbine section must provide reliable operation with low or medium Btu gaseous coal derived fuel at turbine inlet temperature levels above 2600°F.

Utilization of low Btu gas (LBG) fuel for attainment of temperature levels up to 3000°F in a gas turbine combustor environment presents several unique design and development problems. Because of the extremely high stoichiometric ratios required to attain 3000°F, the management of combustor cooling as well as internal air and low Btu gas fuel flow mixing patterns is considered critical for high combustion efficiency and stability. Equally important is the requirement for long term combustor durability. A unique combustor design concept has been developed to utilize the available heat sink capability of the LBG fuel to adequately cool the combustor walls for long service life.

Under a U.S. Department of Energy contract, an LBG fuel cooled combustor was designed for operation with 150 Btu/SCF fuel for use in development of a turbine capable of operating at 3000°F. This paper describes the background combustor technology and test program results with 150 Btu/SCF fuel regarding the combustion stability, efficiency, emissions and burner wall temperature levels for operation up to 3000°F exit gas temperatures and 6 atmospheres.
Developments in Air Cooling of Gas Turbine Vanes and Blades
Authors: Metzger Darryl E.
Published: April 2015

Over the history of gas turbine engine development, improvements in engine performance are closely tied to increases in the level of tolerable turbine inlet temperatures. The ability to operate at increasingly high temperatures has been the result of both improvements in materials capability and advances in the art of cooling the hot section components. For propulsion engines and their derivatives the cooling medium is air supplied from the compressor stages, requiring an expense of engine power. The hot section airfoils, particularly the first stage vanes and blades, consume a significant fraction of the total engine cooling air. Designers are continuously faced with the task of making more effective use of the coolant to improve either performance or durability or both. The design process requires detailed knowledge of heat transfer and flow friction characteristics for present and candidate future cooling schemes. Typical current cooling schemes and associated research work directed to future improved designs are discussed.
Advancing Electronic Technology Impact on Integrated Propulsion/Airframe Controls Design and Development
Authors: Houchard J. , Carlin C. , Tjonneland E.
Published: April 2015

Many exciting opportunities to enhance aircraft performance, cost and reliability/availability are rapidly becoming available to the propulsion system designer, with use of digital electronics, information/sensor sharing between airframe systems, and integrated functional designs for propulsion and aircraft flight controls. The propulsion engineer must become an active participant in this area to take full advantage of the advanced technology. In this endeavor, he is faced with the task, which seems to occur all so frequently in a rapidly advancing technology age, of developing new working tools and approaches not normally part of the propulsion engineers experience. A discussion is presented of some key technologies available to the propulsion designer, such as digital electronics, serial data buses, analytical redundancy and avionics standards. Analytical tools in computational fluid flow analysis and modern control theories are reviewed. These tools can be utilized to provide the analytical understanding of the flow characteristics of the propulsion system and to develop the optimal control laws for multivariable, integrated control systems. A design methodology for integrating the propulsion control system with the aircraft controls and avionics systems is presented. The required simulation facilities necessary for the development and checkout of integrated systems are described with examples of their use in advanced research projects.
A Simple One-Dimensional Model for Primary Turbine Blade Erosion Prediction
Authors: Dussourd J. L.
Published: April 2015

Sophisticated models to predict the erosion process in turbine blades exposed to dust laden gas stream quickly become complex and tedious for use for everyday engineering applications. A simpler model for primary erosion can be formulated by assimilating the blade row to a device having a certain size and deflecting the stream through a given angle and at a given rate. The technology which exists for particle impacts physics with bluff bodies can be adapted to cascades. Thus, basically the model is derived from first principles.

This approach is formulated in a quantitative manner in terms of cascade parameters, gas properties, and particulate parameters. The result is a simple equation which is easy to use and the physics of which are logical and intuitively reasonable. Its predictive ability, however, is limited to the frequency of impacts and the strength of the impacts. It does not address the mechanics of the impact process or the properties of the material being impacted. These variables are introduced through an experimental coefficient which, as it turns out, is the only experimental input in the analysis.

The method is tested against quite a few experimental cases with a degree of predictive ability which is acceptable in a simple, first order method. The agreement is thought to be at least as good as the credibility or accuracy of the test data. The method is finally applied to study the effects of various blade cascade parameters on erosion resistance, the results of which are presented in the form of general curves.
Effect of Particle Rebound Characteristics on Erosion of Turbomachinery Components
Authors: Wakeman T. , Tabakoff W.
Published: April 2015

Extensive high temperature solid particle rebound characteristics testing and analysis has been continuing at the University of Cincinnati. These measurements have been done in the high temperature erosion wind tunnel facility. The target material effect on rebounding characteristics when exposed to high temperatures has been investigated analytically. In addition, measurements have been completed for the following target materials: INCO 718, Ti 6-4, 2024 Al, Lead and Beryllium. Useful particle rebound characteristics have been derived from the measured data. The measured impulse relationship can be used to estimate the force interaction between the particle and the target material during the impact event. The particle rebound characteristics are very important parameters for calculating the particle trajectories and consequently predicting the erosion damages.