bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estimating Uniaxial Compressive Strength of Tropically Weathered Sedimentary Rock Using Indirect Tests
Authors: Liang Maybelle , Mohamad Edy Tonnizam , Khun Ma Chau , Alel Mohd Nur Asmawisham 
Published: April 2015

Uniaxial compressive strength (UCS) of intact rock is particularly important in rock mechanic studies, especially for those involving civil and mining projects. However, the determination of UCS using direct test is generally expensive, time consuming and almost impossible in preparation of samples for highly weathered sedimentary rocks. In view of this, indirect tests are comparatively cheap, simpler, faster and more convenient to perform either in laboratory or at site. This paper aims to develop an estimation procedure in determining the UCS values of such weak weathered rocks. Among the indirect tests present herein are point load index, Schmidt Rebound hammer, Brazilian tensile test and slake durability test. Unfortunately, it was found that the accuracy of each single test varies with weathering states. Hence, a recommended procedure using combined indirect tests in determining UCS of weak sedimentary rocks is presented herein.
Review of Available Transfer Capability Determination with Grid Connected Hybrid Wind System using Probabilistic Collocation Method
Authors: Khairuddin Azhar , A. I. Alhammi 
Published: April 2015

Any distribution system with large integration of renewable energy based dispersed generations exposed to several difficulties clearly appeared while evaluating complex large-scale system Available Transfer Capability (ATC), where it is considered as one of the indices reflecting levels of reliability and security for power systems. This paper presents a review of ATC determination of the hybrid wind connected system using Probabilistic Collocation Method (PCM) under transient stability, voltage constraints. Applications of PCM technique in several electrical fields of power system transient-state evaluation are also debated, compared with Monte Carlo method. The first results shows the vast time saving obtained using PCM, with satisfied accuracy. The main goal of the review is to exploring different available usages of PCM technique and their corresponding suitable so that a reasonably precise and effective PCM algorithm can be determined for the concerned system, the relevant theory is outlined here, and unpretentious examples are applied to illustrate the applicability computation of ATC value implementing PCM method, as well as an example with a more credible power system, are obtainable. The feasibility of the suggested method would be validating through in the IEEE-24 RTS bus system.
Hyperspectral Imaging for Predicting Soluble Solid Content of Starfruit
Authors: Candra Feri , Abu Bakar Syed Abd. Rahman 
Published: April 2015

Hyperspectral imaging technology is a powerful tool for non-destructive quality assessment of fruits. The objective of this research was to develop novel calibration model based on hyperspectral imaging to estimate soluble solid content (SSC) of starfruits. A hyperspectral imaging system, which consists of a near infrared camera, a spectrograph V10, a halogen lighting and a conveyor belt system, was used in this study to acquire hyperspectral images of the samples in visible and near infrared (500-1000 nm) regions. Partial least square (PLS) was used to build the model and to find the optimal wavelength. Two different masks were applied for obtaining the spectral data. The optimal wavelengths were evaluated using multi linear regression (MLR). The coefficient of determination (R2) for validation using the model with first mask (M1) and second mask (M2) were 0.82 and 0.80, respectively.
Semi-Automatic Red Blood Cells Counting in Microscopic Digital Images
Authors: Abbas Naveed , Mohamad Dzulkifli , Abdullah Abdul Hanan 
Published: April 2015

The main purpose of this study is to employ the modern technologies and techniques to semi-automate the quantification process of the Red Blood Cells in Microscopic thin blood smear digital images. The process needs to be more accurate, efficient and universal then the currently practiced methods. The study considers the process to be semi-automated for two reasons, i.e. due to the critical aspect life and due to the diverse nature of the Red Blood Cells in cluster formation. The Methodology of this study involved interactive simple cuts and morphological operations for splitting clusters of Red Blood Cells while counting is carried out through labeling matrix. The Red Blood Cells counting is part of the complete blood count test and is frequently suggested by the Physician to know the number of Red Blood Cells in the patient’s body. The proposed method considers for counting process of the Red Blood Cells first split the clusters and then count the Red Blood Cells. The proposed method achieved an overall True Positive Rate (TPR) of 0.997%, True Negative Rate (TNR) of 0.00265%, accuracy of 0.998% and average error rate of 0.001375% tested on 50 images, data set also on the same number of images linear correlation coefficient R2 is 0.997 between manual and semi-automatic counting of Red Blood Cells.
Introducing an Application of a Charged Coupled Device (CCD) in an Optical Tomography System
Authors: Jamaludin Juliza , Abdul Rahim Ruzairi , Abdul Rahim Herlina , Fazalul Rahiman Hafiz , Mohd Muji Siti Zarina , Mohd Fadzil Naizatul Shima , Pei Ling Leow , Jumaah Fahjumi , Ahmad Anita , Nor Ayob Nor Muzakkir , En Hong Ling 
Published: April 2015

A tomographic system is a method used for capturing an image of an internal object section. Optical tomography is one method which widely used in medical and industrial fields. This paper reviews several applications of Charged Coupled Devices (CCD) and introduces an application of a CCD in an optical tomography system. Most of the previous research used this component for displacement measurement and as a video camera. This paper discusses its basic principle of operation, basic construction, its criteria, application, and its advantages compared to other optoelectronic sensors available in today’s market. The applications of this sensor in fields such as astronomy and medical has proved the ability and the good performance of CCD in capturing images. This sensor should widen its usage in optical tomography fields because it can give high performance in image reconstruction.
Evaluation Of Volumetric Properties And Resilient Modulus Performance Of Nanopolyacrylate Polymer Modified Binder (NPMB) Asphalt Mixes
Authors: Shaffie Ekarizan , Ahmad Juraidah , Arshad Ahmad Kamil , Kamarun Dzraini 
Published: April 2015

This paper presents the potential benefits of nanopolyacrylate (NPA) for the asphalt mixtures used on pavement. This research evaluates the resilient modulus performance of dense graded Superpave-designed HMA mix. Two different types of dense graded Superpave HMA mix were developed consists of unmodified bitumen mix (UMB) and nanopolyacrylate modified bitumen mix (NPMB). Nanopolyacrylate polymer modified bitumen was prepared from addition of 6 percent of NPA polymer into asphalt bitumen. Resilient modulus results from Resilient Modulus test were determined to evaluate the performance of these mixtures. Results showed that all the mixes passed the Superpave volumetric properties criteria which indicated that these mixtures were good with respect to durability and flexibility. The Resilient modulus result of NPMB demonstrates better resistance to rutting than those prepared using UMB mix. It was estimated that the average resilient modulus values for both UMB and NPMB mixtures are decreased by 80 percent when the test temperature increased from 25ºC to 40ºC. In conclusion, the addition of NPA to the binder has certainly improved the bitumen properties significantly and hence increase the resistant to rutting of the asphalt mixture.
Evaluation of Effects of Extended Short-Term Aging on the Rheological Properties of Asphalt Binders at Intermediate Temperatures Using Respond Surface Method
Authors: Hamzah Meor Othman , Omranian Seyed Reza , Golchin Babak , Hainin Mohd Rosli 
Published: April 2015

Predicting the effects of short term aging on asphalt binders’ rheological properties can be a complicated task. This is due to the exposure of different binders to different conditions. Hence, the utilization of a Respond Surface Method (RSM) is a practical way to predict these effects. An experimental matrix was planned to predict asphalt binders behavior at intermediate temperatures based on the central composite design for aging duration and test temperature. The test results showed that prolonging aging increased the binder complex modulus, but decreased the phase angle, while increasing the test temperature decreased the complex modulus but increased the phase angle. However, the trends in aging differ and depend on the binder type, test temperature and aging conditions. It was also found that the RSM method is a fast, effective and reliable tool to predict the effects of aging on binders’ rheological behavior.
Housing Bubble in Penang Prediction and Determinants
Authors: Yun Lu Loh , YM Lee Janice , Al-mulali Usama , Ahmad Nurul Afiqah , Mohammad Izran Sarrazin 
Published: April 2015

House prices in Malaysian cities increased drastically in the past few years, notably in the state of Penang. The existence of a housing bubble is speculated by major property players. This paper ascertains whether a housing bubble exists in Penang and explores the long-run and short-run determinants of Penang residential prices. Quarterly data (2000Q1 to 2012Q2) of House Price Index is the dependent variable and Gross Domestic Product, Consumer Price Index (CPI), Base Lending Rate (BLR) and Housing Supply as independent variables. Econometric model together with fully modified Ordinary Least Squares regression were used to detect the presence of housing bubble in Penang. The determinants of Penang house prices are based on Granger causality and variance decomposition analysis using the vector autoregressive (VAR) model. The results show no evidence of housing bubble in Penang housing market. CPI has both long-run and short run causality relationship with house prices while CPI and BLR explain a large part of housing price variance. Results show changes in inflation and cost of borrowing will greatly affect Penang house prices.
Turbine or Electric Motor Driven Gas Compressors on Production Platforms
Authors: Overli J. M. , Magnusson R. 
Published: April 2015

This paper describes the results obtained from a study commissioned to ascertain the optimum drive arrangements for the gas compression machinery to be installed on an integrated platform in the North Sea.
The study was restricted to two main drive type alternatives:
- All compressor stages on one shaft driven by a variable speed aero-derivative gas turbine.
- All compressor stages with separate, constant speed, electric motor drives.
The study took into account drive option and shafting arrangements with regard to flexibility of operation, weight, area, lay-out, foundation/alignment, waste heat recovery requirements, availability/reliability, safety, maintenance, fuel consumption, investment cost and operational experience.
For the specific case studied, the overall conclusion was in favour of the gas turbine drive alternative.
Boundary Conditions for the Potential Equation in Transonic Internal Flow Calculation
Authors: Deconinck H. , Hirsch Ch. 
Published: April 2015

An analysis of internal potential flow is presented showing the existence of multiple potential solutions with shocks for a given mass flow rate. These solutions are related to non isentropic Euler solutions.
Inflow and outflow boundary conditions are proposed which uniquely determine the shock position allowing the calculation of potential flows which are either choked or have a supersonic inlet.
Numerical computations using a multigrid finite element approach are presented and compared with exact quasi-one-dimensional Euler solutions confirming the ability of the potential method to solve accurately supersonic and choked nozzle flows.
Emissions Variability and Traversing on Production RB211 Engines
Authors: Hawkins H. L. , Bhangu J. K. , Priddin C. H. , Walker P. H. 
Published: April 2015

In order to control the emissions from aircraft gas turbines, the International Civil Aviation Organisation (I.C.A.O.) and the U.S. Environmental Protection Agency (E.P.A.) have, through consultations with the various parties over the past decade, made firm proposals for an emission certification scheme, together with mandatory limiting levels for certain pollutants. The compliance with the proposed emission standards requires that a representative sample is collected from the engine exhaust plane and transported without changing its chemical composition to the analysis instruments. Despite clearly defined rules for sample transfer and analysis methods, the emissions measurement will be subject to variability due to the following factors:
a) engine-to-engine variability which will include the impact of dimensional tolerance on the combustor hardware and other components which affect the combustor performance,
b) sampling variation because of the nonuniform distribution of the pollutant species in the exhaust plane (see references 4,5), with the result that engine manufacturers are required to demonstrate “by means of detailed traverse measurements in the sampling plane” that a specific probe design provides a representative sample,
and
c) gas analysis instrumentation scatter that occurs in the actual analysis of identical samples.
Ceramic Applications in Turbine Engines (CATE) Development Testing
Authors: Helms H. E. , Thrasher S. R. 
Published: April 2015

The objective of the CATE program was to apply ceramic components to the hot flow path of an existing vehicular gas turbine engine and thereby demonstrate the feasibility of structural ceramic components. To accomplish this the Allison IGT 404-4 gas turbine engine has operated at successively higher temperatures made possible by the introduction of ceramic components with performance and component durability demonstrations. Extensive ceramic material characterization, supplier process development work, development of non-destructive inspection (NDI) techniques, rig ceramic component development and proof testing, and engine demonstration testing have been conducted.
This paper describes the CATE Project concept for development testing of ceramic components for use in vehicular gas turbine engines. Included will be the approach to development testing, a description of the CATE GT 404 engine and the ceramic components designed for that engine, a summary of the development test experience accumulated on the ceramic components, an assessment of the results and benefits gained from the program, and recommendations for follow-on component development work.
The Measurement of Turbomachinery Stator-to-Drum Running Clearances
Authors: Davidson David P. , DeRose Robert D. , Wennerstrom Arthur J. 
Published: April 2015

The clearance between a compressor or turbine case and rotating blades or shrouds has been measured in a variety of ways over the years with varying degrees of accuracy. However, one critical clearance which has defied active measurement heretofore has been that between the tip of a cantilevered stator vane and an adjacent drum rotor. A significant number of turbomachines under development, representing many millions of dollars, have met an inglorious end through unanticipated rubs which were experienced in this area.
The present paper describes how a device which was introduced by its manufacturer for conventional rotor tip or shroud clearance measurements was applied to measure stator-vane-to-drum clearance. The installation technique is explained, and the results of vane-to-drum measurements made with a research compressor are presented. Adaptations of the same technique should permit similar measurements to be made within a turbine, and possibly on rotating seals buried deep within a turbomachine.
Redesign and Performance Analysis of a Transonic Axial Compressor Stator and Equivalent Plane Cascades With Subsonic Controlled Diffusion Blades
Authors: Dunker R. , Rechter H. , Starken H. , Weyer H. 
Published: April 2015

In order to verify a new controlled diffusion blade design concept, the stator of an existing transonic axial compressor stage was redesigned. Stator and equivalent cascade tests revealed the potential of such blades for a considerably higher aerodynamic loading than it has been applied up to now.
The design procedure is described and the results of plane cascade and stage testing are submitted including performance analysis of both, cascade and stator blade sections, at design and off-design operating conditions.
The blade profile shapes and cascade geometries were calculated by means of an inverse 2-dimensional method taking also into account the axial velocity density ratio (AVDR). This design concept is essentially based on prescribed blade pressure distributions which are optimized with respect to the blade boundary layer development.
The flow phenomena are illustrated by means of loss and flow turning investigations, blade pressure distributions and laser velocimetry data.
The test results reveal that the 2-D approach applied is quite promising for the 3-D stator blade design. Finally overall and blade element performance comparisons between the original NACA 65 profiled stator and the redesigned one demonstrate the favourable flow behaviour of the new stator as well as the great potential of the controlled diffusion blade concept.
Vectoring Exhaust Systems for STOL Tactical Aircraft
Authors: Tape R. F. , Hartill W. R. , Curry S. , Jones T. J. 
Published: April 2015

An analytical study has been performed to investigate the performance and application of four exhaust nozzle concepts with the potential to enhance the short takeoff and landing capabilities of advanced tactical aircraft for the 1990’s. The exhaust system concepts include side and rear exhaust thrust vectoring systems with axisymmetric and non-axisymmetric nozzles.
To investigate the application of the nozzle concepts, advanced tactical aircraft have been configured which will operate from 700 or 1000 feet fields. Four different propulsion system configurations were used, each producing glide slope equilibrium in a different way.
The characteristics of these STOL aircraft are compared with those of a CTOL aircraft designed to perform the same mission. The results show that the short field performance can be achieved with little aircraft TOGW or LCC penalty. The study also identifies promising configurations for STOL tactical aircraft.
Stiffness Derivative Finite Element Technique to Determine Nodal Weight Functions With Singularity Elements
Authors: Sha George T. 
Published: April 2015

The use of the stiffness derivative technique coupled with “quarter-point” singular crack-tip elements permits very efficient finite element determination of both stress intensity factors and nodal weight functions. Two-dimensional results are presented in this paper to demonstrate that accurate stress intensity factors and nodal weight functions can be obtained from relatively coarse mesh models by coupling the stiffness derivative technique with singular elements.
The principle of linear superposition implies that the calculation of stress intensity factors and nodal weight functions with crack-face loading, σ(rs), is equivalent to loading the cracked body with remote loads, which produces σ(rs) on the prospective crack face in the absence of crack. The verification of this equivalency is made numerically, using the virtual crack extension technique. Load independent nodal weight functions for two-dimensional crack geometry is demonstrated on various remote and crack-face loading conditions. The efficient calculation of stress intensity factors with the use of the “uncracked” stress field and the crack-face nodal weight functions is also illustrated.
In order to facilitate the utilization of the discretized crack-face nodal weight functions, an approach was developed for two-dimensional crack problems. Approximations of the crack-face nodal weight functions as a function of distance, (rs), from crack-tip has been successfully demonstrated by the following equation:
h a , r s = A a √ r s + B a + C a √ r s + D a r s
Coefficients A(a), B(a), C(a) and D(a), which are functions of crack length (a), can be obtained by least-squares fitting procedures. The crack-face nodal weight functions for a new crack geometry can be approximated using cubic spline interpolation of the coefficients A, B, C and D of varying crack lengths. This approach, demonstrated on the calculation of stress intensity factors for single edge crack geometry, resulted in a total loss of accuracy of less than 1%.
Operating Experience With a Waste Heat Recovery System Installed on a Pipeline Compressor Station
Authors: Vogt G. M. 
Published: April 2015

Construction of the Borsig waste heat recovery system at NOVA’s Clearwater Compressor Station is now complete. Initial operation of the system has been very encouraging.
This paper is an update on an earlier paper entitled “Pipeline Compressor Station with Waste Heat Recovery” by G. M. Holldorff, A. R. Hladun and S. A. Dunn. The process cycle including main components and control functions will be reviewed and their performance evaluated. Operating experience to date is also presented.
In emphasizing safety, NOVA has instituted unique operating and maintenance procedures to this system. These procedures are also outlined.
STOL Fighter Technology Program
Authors: Selegan David R. 
Published: April 2015

In recent years, the Air Force has provided additional funds to investigate the technologies and problems associated with providing fighters a Short Take Off and Landing (STOL) capability without seriously degrading today’s maneuver, load, and cruise performance. Within the Flight Dynamics Laboratory, this technology thrust has been planned and organized under the title of “Runway Independence.”
The thrust is multi-disciplined in that the following technologies are being investigated both singularly and in integrated combinations to quantify their contribution to providing options in solving the STOL design task. These technologies are: aerodynamics, integrated controls, thrust vectoring/reversing exhaust nozzles, landing gear, and cockpit aids and controllers necessary to operate under weather and/or at night.
To help focus these technology efforts and to mature existing technology, the STOL Technology Fighter program was formulated. The objective of the program is to flight validate and mature near-term advanced technologies applicable to providing a STOL capability without sacrificing today’s maneuver, cruise or dash performance. Specific technologies to be addressed in this program are: two-dimensional thrust vectoring/reversing exhaust nozzle; integrated flight/propulsion control; advanced high lift systems; rough/soft field landing gear; and cockpit aids and controllers necessary to locate and land a fighter on the usable portion of the runway at night and in weather.
The program will either modify an existing fighter like the F-15, F-16 or F-18 or build a hybrid vehicle like the X-29 with these technologies integrated into the vehicle. The contract will be awarded in 1983 with first flight in late 1987. The end objective of the program is to demonstrate take offs and landings under wet runway conditions of under 1500 feet including dispersion. This paper discusses the integration of these technologies into a total flight program.