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2012

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Articles 18841 - 18870 of 23304

Full-Text Articles in Social and Behavioral Sciences

Development Of Sipm-Based Scintillator Tile Detectors For A Multi-Layer Fast Neutron Tracker, R Preston, J Jakubek, D Prokopovich, J Uher Jan 2012

Development Of Sipm-Based Scintillator Tile Detectors For A Multi-Layer Fast Neutron Tracker, R Preston, J Jakubek, D Prokopovich, J Uher

Faculty of Engineering and Information Sciences - Papers: Part A

We are developing thin tile scintillator detectors with silicon photomultiplier (SiPM) readout for use in a multi-layer fast-neutron tracker. The tracker is based on interleaved Timepix and plastic scintillator layers. The thin 15 x 15 x 2 mm plastic scintillators require suitable optical readout in order to detect and measure the energy lost by energetic protons that have been recoiled by fast neutrons. Our first prototype used dual SiPMs, coupled to opposite edges of the scintillator tile using light-guides. An alternative readout geometry was designed in an effort to increase the fraction of scintillation light detected by the SiPMs. The …

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The Explanatory Role Of Computation In Cognitive Science, Nir Fresco Jan 2012

The Explanatory Role Of Computation In Cognitive Science, Nir Fresco

Faculty of Engineering and Information Sciences - Papers: Part A

Which notion of computation (if any) is essential for explaining cognition? Five answers to this question are discussed in the paper. (1) The classicist answer: symbolic (digital) computation is required for explaining cognition; (2) The broad digital computationalist answer: digital computation broadly construed is required for explaining cognition; (3) The connectionist answer: subsymbolic computation is required for explaining cognition; (4) The computational neuroscientist answer: neural computation (that, strictly, is neither digital nor analogue) is required for explaining cognition; (5) The extreme dynamicist answer: computation is not required for explaining cognition. The first four answers are only accurate to a first …

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Momentum Balance Method And Estimation Of Boundary Shear Stress Distribution, Shu-Qing Yang, Nadeesha Chamini Dharmasiri, Yu Han Jan 2012

Momentum Balance Method And Estimation Of Boundary Shear Stress Distribution, Shu-Qing Yang, Nadeesha Chamini Dharmasiri, Yu Han

Faculty of Engineering and Information Sciences - Papers: Part A

Determination of local boundary shear stress is an important topic in hydraulic engineering. When attempting to determine this from a very thin boundary region, it is a difficult one because it requires special skills and instruments to treat the measured data. With the advent of new equipment, like the acoustic Doppler velocity profilers (ADVP), all the velocity profiles in the primary flow region can be simultaneously measured, and it is necessary to develop a new method to estimate the boundary shear stress using the primary flow data. This paper presents such a method called the momentum balance method (MBM). A …

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Behaviour Of Cfrp Wrapped Square Rc Columns Under Eccentric Loading, Xu Lei, Thong Minh Pham, Muhammad N. Hadi Jan 2012

Behaviour Of Cfrp Wrapped Square Rc Columns Under Eccentric Loading, Xu Lei, Thong Minh Pham, Muhammad N. Hadi

Faculty of Engineering and Information Sciences - Papers: Part A

Fibre Reinforced Polymer (FRP) is an excellent material to strengthen existing structures. However, the confinement efficiency of FRP - confined square columns is relatively low compared to circular columns due to stress concentration at the sharp corners. This paper presents a new techniqu e aimed to maximise the efficiency of FRP confinement for square concrete columns : circularisation using segmental circular concrete covers . Sixteen square reinforced concrete columns were cast. Four were used as a reference group; four were rounded 20 mm at each corner and wrapped with three layers of CFRP simulating the conventional methods; the rest eight …

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Isometric Representations Of Totally Ordered Semigroups, M A. Aukhadiev, V H. Tepoyan Jan 2012

Isometric Representations Of Totally Ordered Semigroups, M A. Aukhadiev, V H. Tepoyan

Faculty of Engineering and Information Sciences - Papers: Part A

Let S be a subsemigroup of an abelian torsion-free group G. If S is a positive cone of G, then all C*-algebras generated by faithful isometrical non-unitary representations of S are canon- ically isomorphic. Proved by Murphy, this statement generalized the well-known theorems of Coburn and Douglas. In this note we prove the reverse.

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Delivering Zero Carbon Homes In The Uk, Emma Elizabeth Heffernan, Wei Pan, Xi Liang Jan 2012

Delivering Zero Carbon Homes In The Uk, Emma Elizabeth Heffernan, Wei Pan, Xi Liang

Faculty of Engineering and Information Sciences - Papers: Part A

In the UK and internationally, a plethora of voluntary and mandatory energy efficiency standards for new buildings exist, with the common aim of mitigating the impact of new buildings on climate change. However, the take-up of voluntary schemes has been limited and, as a result, many governments have seen the need to introduce mandatory schemes through legislation; from 2016 all new build homes in England and Wales will be required to achieve zero carbon in regulated energy consumption. The international context of voluntary and mandatory building energy efficiency standards is examined through a review of the literature. The review is …

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Cold Model Study Of Blast Gas Discharge From The Taphole During The Blast Furnace Hearth Drainage, Qinglin He, Geoffrey M. Evans, Paul Zulli, Francis Tanzil Jan 2012

Cold Model Study Of Blast Gas Discharge From The Taphole During The Blast Furnace Hearth Drainage, Qinglin He, Geoffrey M. Evans, Paul Zulli, Francis Tanzil

Faculty of Engineering and Information Sciences - Papers: Part A

Blast gas discharge from the taphole in the course of the blast furnace hearth drainage was experimentally studied using a packed bed cold model. It was found that gas break-through time was strongly influenced by the furnace operating conditions and coke bed structure. Gas break-through time decreases with (a) increasing draining rate; (b) decreasing slag and iron levels in the hearth; and (c) increasing slag viscosity. It increases with an increase in the coke-free layer depth and coke-free space width. Under certain conditions, the gas-liquid interface in the region directly above the taphole becomes unstable, leading to viscous finger formation …

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Long-Distance Walking Effect On Below-Knee Amputee Compensatory Gait Patterns And Implications On Prosthetic Designs And Training, L F. Yeung, Aaron Leung, Ming Zhang, Winson Lee Jan 2012

Long-Distance Walking Effect On Below-Knee Amputee Compensatory Gait Patterns And Implications On Prosthetic Designs And Training, L F. Yeung, Aaron Leung, Ming Zhang, Winson Lee

Faculty of Engineering and Information Sciences - Papers: Part A

Trans-tibial amputees are advised to walk as much as able people to achieve healthy and independent life. However, they usually have difficulties in doing so. Previous researches only included data from a few steps when studying the gait of amputees. Walking over a long distance was rarely examined. The objective of this study was to investigate the changes in spatial-temporal, kinetic and kinematic gait parameters of trans-tibial amputees after long-distance walking. Six male unilateral trans-tibial amputees performed two sessions of 30-min walking on a level treadmill at their self-selected comfortable speed. Gait analysis was undertaken over-ground: (1) before walking, (2) …

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A Real-Time In Vivo Dosimetric Verification Method For High-Dose Rate Intracavitary Brachytherapy Of Nasopharyngeal Carcinoma, Zhen-Yu Qi, Xiao-Wu Deng, X Cao, Shao-Min Huang, Michael L. Lerch, Anatoly B. Rosenfeld Jan 2012

A Real-Time In Vivo Dosimetric Verification Method For High-Dose Rate Intracavitary Brachytherapy Of Nasopharyngeal Carcinoma, Zhen-Yu Qi, Xiao-Wu Deng, X Cao, Shao-Min Huang, Michael L. Lerch, Anatoly B. Rosenfeld

Faculty of Engineering and Information Sciences - Papers: Part A

Purpose: A real-time in vivo dosimetric verification method using metal-oxide-semiconductor field effect transistor (MOSFET) dosimeters has been developed for patient dosimetry in high-dose rate (HDR) intracavitary brachytherapy of nasopharyngeal carcinoma (NPC). Methods: The necessary calibration and correction factors for MOSFET measurements in 192Iridium source were determined in a water phantom. With the detector placed inside a custom-made nasopharyngeal applicator, the actual dose delivered to the tumor was measured in vivo and compared to the calculated values using a commercial brachytherapy planning system. Results: Five MOSFETs were independently calibrated with the HDR source, yielding calibration factors of 0.48 ± 0.007 cGymV. …

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Analysis Of Thermal Stress During Of Twin-Roll Casting Of Magnesium Alloy, Yucheng Zhang, T Han, Zhengyi Jiang, Dongbin Wei Jan 2012

Analysis Of Thermal Stress During Of Twin-Roll Casting Of Magnesium Alloy, Yucheng Zhang, T Han, Zhengyi Jiang, Dongbin Wei

Faculty of Engineering and Information Sciences - Papers: Part A

The process of twin-roll casting including pouring, solidifying, rolling and cooling can be accomplished in a very short time. Consequently, some important process parameters in the twin-roll casting that are difficult to be obtained in experiment can be acquired using numerical simulation. In this paper, a numerical simulation based on a 2D finite element model of vertical twin-roll strip casting of magnesium alloy has been conducted, and the thermal stress fields are significantly discussed. The influences of key process parameters consisting of submerged nozzle depth and nozzle spray angle have been studied. The thermal cracks on the surface of the …

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Biocompatible Ferroelectric (Na,K)Nbo3 Nanofibers, A Jalalian, A M. Grishin Jan 2012

Biocompatible Ferroelectric (Na,K)Nbo3 Nanofibers, A Jalalian, A M. Grishin

Faculty of Engineering and Information Sciences - Papers: Part A

"Dense homogeneous textile composed from continuous bead-free sodium potassium niobate (NKN) nanofibers 100 mu m long and 50-200 nm in diameter was sintered by sol-gel calcination assisted electrospinning. High resolution electron microscopy and x-ray diffraction revealed preferential cube-on-cube growth of fibers in [001] direction. Raman spectrum of NKN fibers contains all the features characteristic to electrically poled orthorhombic phase. In contrast to polycrystalline ceramics, it shows relative enhancement of the Raman cross section of isotropic A(1g)(nu(1)) mode compared with polar axis defined F(2g)(nu(5)) and E(g)(nu(2)) vibrations. We interpret this as an evidence for superparaelectric state of NKN nanofibers. Spontaneous polarization …

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Towards Formalizing A Reputation System For Cheating Detection In Peer-To-Peer-Based Massively Multiplayer Online Games, Willy Susilo, Yang-Wai Chow, Rungrat Wiangsripanawan Jan 2012

Towards Formalizing A Reputation System For Cheating Detection In Peer-To-Peer-Based Massively Multiplayer Online Games, Willy Susilo, Yang-Wai Chow, Rungrat Wiangsripanawan

Faculty of Engineering and Information Sciences - Papers: Part A

The rapidly growing popularity of Massively Multiplayer Online Games (MMOGs) has given rise to an increase in the number of players world wide. MMOGs enable many players interact together through a shared sense of presence created by the game. The Peer-to-Peer (P2P) network topology overcomes communication bottleneck problems associated with centralized client/server sys- tems. Thus, P2P-based MMOGs are seen as the way of the future, and many dierent P2P-based MMOG architectures have been proposed to date. However, many architectures are proposed in an ad hoc manner and enhancing the security of such systems is an elusive research problem. In this …

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Recent Progress On Programming Methods For Industrial Robots, Zengxi Pan, Joseph Polden, Nathan Larkin, Stephen Van Duin, John Norrish Jan 2012

Recent Progress On Programming Methods For Industrial Robots, Zengxi Pan, Joseph Polden, Nathan Larkin, Stephen Van Duin, John Norrish

Faculty of Engineering and Information Sciences - Papers: Part A

"Although an automated flexible production cell is an intriguing prospect for small to median enterprises (SMEs) in current global market conditions, the complexity of programming remains one of the major hurdles preventing automation using industrial robots for SMEs. This paper provides a comprehensive review of the recent research progresses on the programming methods for industrial robots, including online programming, offline programming (OLP), and programming using Augmented Reality (AR). With the development of more powerful 3D CAD/PLM software, computer vision, sensor technology, etc. new programming methods suitable for SMEs are expected to grow in years to come. (C) 2011 Elsevier Ltd. …

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Mechanics Of Design And Model Development Of Cvc-Plus Roll Curve, Jianzhong Xu, Dianyao Gong, Zhengyi Jiang, Xianghua Liu, Guodong Wang Jan 2012

Mechanics Of Design And Model Development Of Cvc-Plus Roll Curve, Jianzhong Xu, Dianyao Gong, Zhengyi Jiang, Xianghua Liu, Guodong Wang

Faculty of Engineering and Information Sciences - Papers: Part A

The mathematic model of CVC-Plus work roll curve is built. The ratio of the initial shifting value to the target crown is determined, and the mathematical model considering the relationship between the coefficients A2, A3, A4, A5 and is established. According to the theoretical analysis, the distance between the maximum or minimum point of the high order equivalent crown for work roll with CVC-plus roll curve and the rolling central point is the times of the roll barrel length. In general, the initial shifting value of the CVC-plus roll curve is not equal to the initial shifting value of the …

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Multifactor Optimization Of A Fuzzy-Pid Controller Using Genetic Algorithm, Xiaofeng He, Wei Chen, Bihai Zhu, Zhengyi Jiang, Christopher David Cook Jan 2012

Multifactor Optimization Of A Fuzzy-Pid Controller Using Genetic Algorithm, Xiaofeng He, Wei Chen, Bihai Zhu, Zhengyi Jiang, Christopher David Cook

Faculty of Engineering and Information Sciences - Papers: Part A

The design of a Fuzzy-PID controller involves setting the fuzzy rules, membership functions and its associated scaling factors. How to obtain a better control result and how these scaling factors affect the controller's performance are still a challenge. In this paper, the automatic position control system of a Hille 100 experimental rolling mill was used as a research testbed. Based on the mathematical control model of the rolling mill, a Fuzzy-PID controller was developed, and the process of implementing global optimization considering all these factors simultaneously by using genetic algorithm is introduced in detail. Through simulation, the performance of the …

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Study On Surface Roughness And Friction During Hot Rolling Of Stainless Steel 301, Dongbin Wei, Zhengyi Jiang, Junxia Huang, Aiwen Zhang, Xu Shi, Sihai Jiao Jan 2012

Study On Surface Roughness And Friction During Hot Rolling Of Stainless Steel 301, Dongbin Wei, Zhengyi Jiang, Junxia Huang, Aiwen Zhang, Xu Shi, Sihai Jiao

Faculty of Engineering and Information Sciences - Papers: Part A

A well-defined boundary condition is important for generating an accurate model for simulating metal forming process. It is important to characterize the features of the oxide scale in hot rolling of stainless steel strip. Short time oxidation tests in humid air with water vapor content of 7.0 vol. % were carried out using Gleeble 3500 thermo-mechanical simulator. The deformation, surface morphology of oxide scale, and the friction in hot rolling were studied by conducting hot rolling tests. The results show that the surface roughness decreases with an increase of reduction. The effect of oxide scale on friction and surface roughness …

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Nonlinear Analysis Of Biaxially Loaded High Strength Rectangular Concrete-Filled Steel Tubular Slender Beam-Columns, Part I: Theory, Qing Quan Liang, Vipulkumar Ishvarbhai Patel, Muhammad N. S Hadi Jan 2012

Nonlinear Analysis Of Biaxially Loaded High Strength Rectangular Concrete-Filled Steel Tubular Slender Beam-Columns, Part I: Theory, Qing Quan Liang, Vipulkumar Ishvarbhai Patel, Muhammad N. S Hadi

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a new numerical model for the nonlinear inelastic analysis of biaxially loaded high strength thin-walled rectangular concrete-filled steel tubular (CFST) slender beam-columns. The numerical model considers the effects of progressive local buckling, initial geometric imperfections, high strength materials and second order. The accurate fiber element method is used to model the inelastic behavior of composite cross-sections. Theoretical models are developed that simulate the load-deflection responses and strength envelopes of thin-walled rectangular CFST slender beamcolumns under biaxial loads. New computational algorithms based on the M􀂗􁈷 ller's method are developed to adjust the depth and orientation of the neutral …

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The Benefits Of Introducing Electronic Health Records In Residential Aged Care Facilities: A Multiple Case Study, Yiting Zhang, Ping Yu, Jun Shen Jan 2012

The Benefits Of Introducing Electronic Health Records In Residential Aged Care Facilities: A Multiple Case Study, Yiting Zhang, Ping Yu, Jun Shen

Faculty of Engineering and Information Sciences - Papers: Part A

Purpose: Information and communications technology solutions have been introduced into the residential aged care system in order to improve the effectiveness and efficiency of aged care, however to date, the actual benefits have not been systematically analysed. The aim of this study was to identify the benefits of electronic health records (EHR) in residential aged care services and to examine how the benefits have been achieved. Method: A qualitative interview study was conducted in nine residential aged care facilities (RACFs) belonging to three organisations in the Australian Capital Territory (ACT), New South Wales (NSW) and Queensland, Australia. A longitudinal investigation …

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Recrystallisation Behaviour Of Low Carbon Steel With And Without Addition Of Chromium, Azdiar A. Gazder, Vladimir Bata, Sujoy S. Hazra, Elena V. Pereloma Jan 2012

Recrystallisation Behaviour Of Low Carbon Steel With And Without Addition Of Chromium, Azdiar A. Gazder, Vladimir Bata, Sujoy S. Hazra, Elena V. Pereloma

Faculty of Engineering and Information Sciences - Papers: Part A

The effects of 0.74wt% Cr addition on the recrystallisation kinetics of low carbon (LC) steel was investigated using Vickers hardness testing, optical metallography and Electron Back- Scattering Diffraction (EBSD). Compared to the unalloyed steel, Cr addition significantly delays the time for recrystallisation and increases the JMAK pre-exponential factor (k) by an order of magnitude. During initial softening, EBSD returned similar orientations for nucleated and growing grain fractions in both steels. However with longer annealing times the micro-texture of recrystallised grains differs from their earlier counterparts. Overall, the effect of fine Cr carbides on grain boundary mobility in the LC-Cr steel …

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Strain-Induced Phase Transformation During Thermo-Mechanical Processing Of Titanium Alloys, A Dehghan-Manshadi, Rian J. Dippenaar Jan 2012

Strain-Induced Phase Transformation During Thermo-Mechanical Processing Of Titanium Alloys, A Dehghan-Manshadi, Rian J. Dippenaar

Faculty of Engineering and Information Sciences - Papers: Part A

Strain-induced phase transformation studies have been conducted in a Ti-6Al-2Sn-4Zr-6Mo alloy. This alloy was subjected to b sub-transus deformation upon slow cooling from the b-phase field and the effect of strain on the extent and morphology of the phase transformation during hot-deformation was determined. In addition, the transformation kinetics and the morphology of the newly formed a-phase were studied following deformation under different cooling conditions. By applying strain, the rate of the b-to-a phase transformation increased significantly during deformation as well as during slow cooling following deformation. This increase in the kinetics of the b-to-a transformation can be ascribed to …

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Comparison Of Some Tests Of Fit For The Inverse Gaussian Distribution, D J. Best, John C. W Rayner, Olivier Thas Jan 2012

Comparison Of Some Tests Of Fit For The Inverse Gaussian Distribution, D J. Best, John C. W Rayner, Olivier Thas

Faculty of Engineering and Information Sciences - Papers: Part A

This paper gives an empirical investigation of some tests of goodness of fit for the inverse Gaussian distribution.

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Synthesis And Electrochemical Properties Of Sn-Sno2/C Nanocomposite, Chuanqi Feng, Meiyu Dan, Chaofeng Zhang, Zaiping Guo, Shiquan Wang, R Zeng Jan 2012

Synthesis And Electrochemical Properties Of Sn-Sno2/C Nanocomposite, Chuanqi Feng, Meiyu Dan, Chaofeng Zhang, Zaiping Guo, Shiquan Wang, R Zeng

Faculty of Engineering and Information Sciences - Papers: Part A

A Sn-Sn02/C nanocomposite was synthesized using the electrospinning method. Thermal analysis was used to determine the content range of Sn and Sn02 in the composite. The composite was characterized by X-ray diffraction, and the particle size and shape in the Sn-SnOiC composite were determined by scanning and transmission electron microscopy. The results show that the Sn-Sn02/C composite takes on a nanofiber morphology, with the diameters of the nanofibers distributed from 50 to 200 nm. The electrOChemical properties of the Sn-SnOiC composite were also investigated. The Sn-SnOiC composite as an electrode material has both higher reversible capacity (887 mAh· g-I). and …

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Multi-Level Controlled Signature, Pairat Thorncharoensri, Willy Susilo, Yi Mu Jan 2012

Multi-Level Controlled Signature, Pairat Thorncharoensri, Willy Susilo, Yi Mu

Faculty of Engineering and Information Sciences - Papers: Part A

In this work, we present and establish a new primitive called Multi-level Controlled Signature. This primitive allows a signer to specify a security level to limit the verifiability of the signature. This primitive works as follows. Without losing generality, we assume the security levels of a group of users are defined in ascending order, where “A” represents the lowest security level and “Z” represents the highest security level, respectively. When a signer signs a message by specifying a security level “C”, all users who have a security level greater than “C” will be able to verify while other users whose …

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Perm: Practical Reputation-Based Blacklisting Without Ttps, Man Ho Allen Au, Apu Kapadia Jan 2012

Perm: Practical Reputation-Based Blacklisting Without Ttps, Man Ho Allen Au, Apu Kapadia

Faculty of Engineering and Information Sciences - Papers: Part A

Some users may misbehave under the cover of anonymity by, e.g., defacing webpages on Wikipedia or posting vulgar comments on YouTube. To prevent such abuse, a few anonymous credential schemes have been proposed that revoke access for misbehaving users while maintaining their anonymity such that no trusted third party (TTP) is involved in the revocation process. Recently we proposed BLACR, a TTP-free scheme that supports ‘reputation-based blacklisting’ — the service provider can score users’ anonymous sessions (e.g., good vs. inappropriate comments) and users with insufficient reputation are denied access. The major drawback of BLACR is the linear computational overhead in …

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Voltage Unbalance Management In Power Systems Based On Iec 61000-3-13:2008: Implications On The Use Of 'Kue Factor', Upuli Jayatunga, Sarath Perera, Philip Ciufo Jan 2012

Voltage Unbalance Management In Power Systems Based On Iec 61000-3-13:2008: Implications On The Use Of 'Kue Factor', Upuli Jayatunga, Sarath Perera, Philip Ciufo

Faculty of Engineering and Information Sciences - Papers: Part A

Voltage unbalance emission allocation principles prescribed in IEC61000-3-13:2008 Technical Report utilise a factor, kuE, which allows separation of the total voltage unbalance that arises at a point of evaluation due to both the load under consideration and the supply network. As per the definition given, this factor (kuE) accounts for the unbalance emission that arises due to the load whereas (1-kuE) accounts for unbalance that arises due to the network. The technical report prescribes a range of values from which a suitable value can be chosen based on the system characteristics, however, no systematic methodologies exist to-date to determine the …

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Simulation Model Of A Grid-Connected Single-Phase Photovoltaic System In Pscad/Emtdc, Brian K. Perera, Sridhar R. Pulikanti, Philip Ciufo, Sarath Perera Jan 2012

Simulation Model Of A Grid-Connected Single-Phase Photovoltaic System In Pscad/Emtdc, Brian K. Perera, Sridhar R. Pulikanti, Philip Ciufo, Sarath Perera

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, a complete simulation model of a grid-connected single-phase two-stage photovoltaic (PV) system with associated controllers is presented. The simulation model is developed in PSCAD/EMTDC simulation program. The component models of the grid-connected PV system include a PV array, a dc-dc boost converter, a voltage source converter (VSC) and an LCL filter. Components of the LCL filter, the dc-link capacitor of the VSC and the inductor of the dc-dc boost converter are established theoretically and that are used in modelling the grid-connected PV system. The control architecture of the presented system incorporates a synchronous reference frame phase-locked-loop (s-PLL), …

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The Effect Of Incomplete Mixing Upon The Belousov-Zhabotinskii Reaction, Ahmed Hussein Msmali, Mark I. Nelson, Maureen P. Edwards Jan 2012

The Effect Of Incomplete Mixing Upon The Belousov-Zhabotinskii Reaction, Ahmed Hussein Msmali, Mark I. Nelson, Maureen P. Edwards

Faculty of Engineering and Information Sciences - Papers: Part A

The aim of this research to investigate the effect of incomplete mixing upon the existence of periodic solutions. To this end we study the behaviour of the Belousov- Zhabotinskii (B-Z) reaction in a batch reactor. The B-Z reaction is a well studied chemical system that exhibits periodic behaviour. Furthermore, simplified mathematical models exist which have been validated both against experimental data and larger chemical mechanisms. Specifically, we study the `Oregonator' model for the B-Z reaction due to Field and Noyes (1974). This consists of five chemical reactions involving three independent chemical intermediates. We extend this model by combining it with …

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Underground Coal Mine Delay Data Analysis System, Ernest Y. Baafi, Ian Porter Jan 2012

Underground Coal Mine Delay Data Analysis System, Ernest Y. Baafi, Ian Porter

Faculty of Engineering and Information Sciences - Papers: Part A

Due to the high levels of uncertainty in underground coal mining operations, delays occur regularly which inadvertently reduce the utilisation of mining equipment. In most coal mines delay data is primarily sourced from shift reports, machine monitoring and production systems. The recording process is initiated commonly at the end of a shift to ensure the correct information is recorded for the managerial decision process. An issue that the Australian coal industry faces is the lack of a standardised delay recording process and delay classification system. Tools used within the industry to analyse delay data are mostly mine specific and offer …

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Modelling A Longwall Production System Using Flexsim 3d Simulation Software, D Cai, E Baafi, I Porter Jan 2012

Modelling A Longwall Production System Using Flexsim 3d Simulation Software, D Cai, E Baafi, I Porter

Faculty of Engineering and Information Sciences - Papers: Part A

Longwall mining accounts for more than 75% of underground coal production in Australia. It is a popular underground coal mining method worldwide, mainly due to its high extraction ratio, high productivity and increased safety due to improved powered support units. A longwall system requires significant capital investment, and it is necessary to minimise the financial risk associated with this investment. Minimisation of this financial risk requires a sound knowledge of the relationship between underlying operational/technical constraints and associated costs. A discrete simulation model using the Flexsim 3D virtual reality environment has been developed to assist management evaluate the impact of …

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Thermodynamic Analysis Of A High-Yield Biochemical Process For Biofuel Production, M Imroz Sohel, Michael W. Jack Jan 2012

Thermodynamic Analysis Of A High-Yield Biochemical Process For Biofuel Production, M Imroz Sohel, Michael W. Jack

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a thermodynamic analysis of a high-yield biochemical process for biofuel production from lignocelluosic biomass based on a previously proposed process. Unlike the standard biochemical process, which ferments sugar intermediates to ethanol, the process under consideration converts sugars to acetic acid which is esterified and hydrogenated to produce ethanol. This process has a significantly higher yield and produces no carbon dioxide. However, we find that the thermodynamic efficiency of the process is not increased in proportion to the yield gain. An additional survey of various biofuel production processes showed no direct correlation between yield and thermodynamic efficiency. This …

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