Science and Technology Studies Commons^™

N-Nitrosamine Rejection By Reverse Osmosis: Effects Of Membrane Exposure To Chemical Cleaning Reagents, Takahiro Fujioka, Stuart Khan, James Mcdonald, Annalie Roux, Yvan Poussade, Jorg Drewes, Long Nghiem

Faculty of Engineering and Information Sciences - Papers: Part A

No abstract provided.

Effect Of Niobium Clustering And Precipitation On Strength Of A Nbti-Microalloyed Ferritic Steel, Andrii Kostryzhev, Abdullah Alshahrani, Chen Zhu, Julie Cairney, Simon Peter Ringer, Chris Killmore, E V. Pereloma

Faculty of Engineering and Information Sciences - Papers: Part A

The microstructure-property relationship of an NbTi-microalloyed ferritic steel was studied as a function of thermo-mechanical schedule using Gleeble 3500 simulator, optical and scanning electron microscope, and atom probe tomography.

Closed-Orbit Dependence On The Field Direction In The Anisotropic Diamagnetic Kepler Problem, A Bruno-Alfonso, Colin Bleasdale, Gustavo Alvarez, R A. Lewis

Faculty of Engineering and Information Sciences - Papers: Part A

The classical orbits of an electron with anisotropic mass interacting with a Coulomb center in the presence of a magnetic field are investigated. It is shown that the shape and duration of the closed orbits depend on the magnetic-field direction. Reasonable agreement with available experimental results for donor-doped silicon samples in a magnetic field is found, when the energy value of the conduction electron is appropriately chosen.

Mean Curvature Flow Of Entire Graphs In A Half-Space With A Free Boundary, V.-M Wheeler

Faculty of Engineering and Information Sciences - Papers: Part A

We study the mean curvature flow of graphs with prescribed contact angle on a fixed, smooth hyperplane in Euclidean space. We obtain long time existence and convergence to a self similar solution of the mean curvature flow orthogonal to the fixed hyperplane.

Attribute-Based Optimistic Fair Exchange: How To Restrict Brokers With Policies, Yang Wang, Man Ho Allen Au, Willy Susilo

Faculty of Engineering and Information Sciences - Papers: Part A

Optimistic fair exchange (OFE) is a kind of protocols for solving the fair exchange problem between two participants with the help of an arbitrator that only needs to be involved when dispute occurs. As far as we are concerned, all previous work on OFE does not take into account user's attributes such as nationality and age. We identify that in some applications, the attributes could play an important role in the exchange to take place, and OFE may not be suitable to these scenarios. We introduce a new notion named attribute-based optimistic fair exchange (ABOFE) to solve the fair exchange …

Optimization And Application Of Process Parameters In An Az61 Alloy Twin-Roll Strip Casting, Jintao Li, Guangming Xu, Hailiang Yu, Lihong Su, Guanyu Deng, Cheng Lu, Lizi He, Huijun Li

Faculty of Engineering and Information Sciences - Papers: Part A

Twin-roll strip casting is a concerned technology for economically producing magnesium alloys sheets. In this paper, numerical simulation of the twin-roll strip casting of an AZ61 magnesium alloy was carried out and the optimal process parameters were obtained. Then, under the conditions obtained through simulation, AZ61 strips of good surface quality were successfully manufactured. The microstructure of the alloy by twin-rolled strip casting is obvious refined compared with that by conventional casting.

A New Empirical Model For Shear Strength Of Reinforced Concrete Beam - Column Connections, Tung Tran, Muhammad N. S Hadi, Thong M. Pham

Faculty of Engineering and Information Sciences - Papers: Part A

A new empirical model to estimate the joint shear strength of both exterior and interior beam-column connections is proposed. In the model, four parameters that have the most influence on joint shear strength are considered. Among these four, a new parameter is introduced to consider the bond condition and the possibility of beam bars transferring joint shear force into the columns. Consideration of this parameter in the model significantly improves the accuracy of the predicted joint shear strength. To calibrate the model, a large database of 98 reinforced concrete (RC) exterior and 73 RC interior beam-column connections displaying joint failure …

Impacts Of Pheromone Modification Strategies In Ant Colony For Data-Intensive Service Provision, Lijuan Wang, Jun Shen, Junzhou Luo

Faculty of Engineering and Information Sciences - Papers: Part A

In the provision of dynamic data-intensive services, the cost and response time of data sets as well as the states of services may change over time. An ant colony system for this problem is studied in this paper. Specifically, we consider changing the QoS attributes of services and replacing a certain number of services with new ones at different frequencies. In order to adapt the ant colony system to handle the dynamic scenarios, several pheromone modification strategies in reaction to changes of the optimization scenarios are investigated. The aim of the strategies is to find a balance between preserving enough …

A Review Of Technical Challenges In Planning And Operation Of Remote Area Power Supply Systems, Yingjie Tan, Lasantha Meegahapola, Kashem M. Muttaqi

Faculty of Engineering and Information Sciences - Papers: Part A

Remote area power supply (RAPS) systems are being used for many years to supply power to rural or remote communities where the utility grid is not accessible. In order to avoid the high operating cost and environmental impact caused by conventional generators, renewable energy resources are currently being utilised in RAPS systems. However, the intermittency of such renewable energy resources greatly impacts on planning and operation of RAPS systems. This paper aims to present a comprehensive review with regard to the RAPS system planning and operation techniques published in the literature. This paper summarises different modelling approaches associated with the …

The Budget Will Be Big On Infrastructure But We Need More Than Just Roads, Garry Bowditch

Faculty of Engineering and Information Sciences - Papers: Part A

The Abbott government is preparing to give Sydney's WestConnex road project a A$2 billion boost in this week's federal budget, part of a broader $10 billion infrastructure package aimed at boosting productivity and private sector investment. Congestion in Sydney continues to escalate with gridlock on roads impacting passenger and freight logistics. The persistence of this situation reflects poorly on project selection and asset management processes, along with distortions that have arisen from poor interactions between the Commonwealth and the states. Reform is urgently needed where there is less focus on ribbon cutting and more use of well-targeted "pinch point" interventions. …

Thermodynamic Considerations Of The Corrosion Of Nickel Ferrite Refractory By Na3alf6-Alf3-Caf2-Al 2o3 Bath, Raymond Longbottom, Sharon Nightingale, Brian Monaghan

Faculty of Engineering and Information Sciences - Papers: Part A

Thermodynamic analysis was carried out to interpret the results of corrosion testing of nickel ferrite samples in cryolite-based baths. The equilibrium between cryolite-based baths and nickel ferrite was considered. Isopleths between cryolite-based baths and nickel ferrite confirmed that for the temperature range of interest (1223-1273 K) there was limited solubility of nickel ferrite in the bath. To better understand the formation of the metal from nickel ferrite, the effect of reducing potentials on nickel ferrite and nickel ferrite-cryolite-based bath systems were considered. The formation of a metal phase was predicted at relatively high pO2. The metal phase was nickel-rich at …

Effect Of Directional Solidification Rate On The Microstructure And Properties Of Deformation-Processed Cu-7cr-0.1ag In Situ Composites, Keming Liu, Zhengyi Jiang, Jingwei Zhao, Jin Zou, Zhibao Chen, Deping Lu

Faculty of Engineering and Information Sciences - Papers: Part A

The influence of directional solidification rate on the microstructure, mechanical properties and conductivity of deformation-processed Cu-7Cr-0.1Ag in situ composites produced by thermo-mechanical processing was systematically investigated. The microstructure was analyzed by optical microscopy and scanning electronic microscopy. The mechanical properties and conductivity were evaluated by tensile-testing machine and micro-ohmmeter, respectively. The results indicate that the size, shape and distribution of second-phase Cr grains are significantly different in the Cu-7Cr-0.1Ag alloys with different growth rates. At a growth rate of 200 μm s-1, the Cr grains transform into fine Cr fiber-like grains parallel to the pulling direction from the Cr dendrites. …

Economic-Emission Dispatch Problem: A Semi-Definite Programming Approach, A M. Jubril, O A. Olaniyan, O A. Komolafe, Philip O. Ogunbona

Faculty of Engineering and Information Sciences - Papers: Part A

A semi-definite programming (SDP) formulation of the multi-objective economic-emission dispatch problem is presented. The fuel cost and emission functions are represented by high order polynomial functions and this was shown to be a more accurate representation of the economic-emission dispatch (EED) problem. Furthermore, the polynomial functions of both objective functions are aggregated into a single objective function using the weighted sum approach. This thus reduces the problem to a standard polynomial optimization problem which was formulated as a hierarchy of semi-definite relaxation problems. The resulting SDP problem was then solved at different degrees of approximation. The performance of the proposed …

Effects Of Hypochlorite Exposure On Morphology And Trace Organic Contaminant Rejection By Nf/Ro Membranes, Alexander R. Simon, Long D. Nghiem

Faculty of Engineering and Information Sciences - Papers: Part A

The impacts of membrane degradation due to chlorine attack on the rejection of inorganic salts and trace organic contaminants by nanofiltration (NF) and reverse osmosis (RO) membranes were investigated in this study. The rejection of trace contaminants was examined at environmentally relevant concentrations. Changes in the membrane surface morphology were observed as a result of chlorine exposure. A small increase in rejection was consistently observed with all four membranes selected in this study after being exposed to a low concentration of hypochlorite (100 ppm). In contrast, a higher concentration of hypochlorite (i.e., 2000 ppm) could be detrimental to the membrane …

Magnetization Curves Of Sintered Heavy Tungsten Alloys For Applications In Mri-Guided Radiotherapy, Stefan Kolling, Bradley Oborn, Paul Keall, Josip Horvat

Faculty of Engineering and Information Sciences - Papers: Part A

Purpose: Due to the current interest in MRI-guided radiotherapy, the magnetic properties of the materials commonly used in radiotherapy are becoming increasingly important. In this paper, mea- surement results for the magnetization (BH) curves of a range of sintered heavy tungsten alloys used in radiation shielding and collimation are presented.

Methods: Sintered heavy tungsten alloys typically contain > 90% tungsten and < 10% of a combina- tion of iron, nickel, and copper binders. Samples of eight different grades of sintered heavy tungsten alloys with varying binder content were investigated. Using a superconducting quantum interference detector magnetometer, the induced magnetic moment m was measured for each sample as a function of applied external field H₀and the BH curve derived.

Results: The iron content of the alloys was found to play a dominant role, directly influencing the magnetization M and thus the nonlinearity of the BH curve. Generally, the saturation magnetization increased with …

Characteristics Of Oxide Scale Formed On Ferritic Stainless Steels In Simulated Reheating Atmosphere, Xiawei Cheng, Zhengyi Jiang, Dongbin Wei, Jingwei Zhao, Brian J. Monaghan, Raymond J. Longbottom, Laizhu Jiang

Faculty of Engineering and Information Sciences - Papers: Part A

The aim of this study is to optimise the stainless steel oxidation behaviours during hot rolling. The high temperature oxidation behaviours of ferritic stainless steels B443NT and B445J1M were studied over the temperature range from 1000 to 1150 °C in a humid atmosphere containing 18% water vapour, as measured by a thermogravimetric analyser (TGA). The results indicate that breakaway oxidation occurs at 1090 °C for the B443NT steel, which is 60 °C lower than that for the B445J1M steel. The occurrence of iron oxide nodules on the steels marks the onset of breakaway oxidation; however, the breakaway oxidation phenomenon of …

Facilitating Social Collaboration In Mobile Cloud-Based Learning: A Teamwork As A Service (Taas) Approach, Geng Sun, Jun Shen

Faculty of Engineering and Information Sciences - Papers: Part A

Mobile learning is an emerging trend that brings many advantages to distributed learners, enabling them to achieve collaborative learning, in which the virtual teams are usually built to engage multiple learners working together towards the same pedagogical goals in online courses. However, the socio-technical mechanisms to enhance teamwork performance are lacking. To meet this gap, we adopt the social computing to affiliate learners’ behaviors and offer them computational choices to build a better collaborative learning context. Combining the features of the cloud environment, we have identified a learning flow based on Kolb team learning experience to realize this approach. Such …

Computationally Efficient Ontology Usage In Software Requirement Planning, Robert B. K Brown Ph.D, Ghassan Beydoun, Graham Low, William Tibben, F Garcia-Sanchez, Reza Zamani, Rodrigo Martinez-Bejar

Faculty of Engineering and Information Sciences - Papers: Part A

Understanding the needs of stakeholders and prioritizing requirements are the vital steps in the development of any software application. Enabling tools to support these steps have a critical role in the success of the corresponding software application. Based on such a critical role, this paper presents a computationally efficient ontology selection in software requirement planning. The key point guiding the underlying design is that, once gathered, requirements need to be processed by decomposition towards the generation of a specified systems design. A representational framework allows for the expression of high level abstract conceptions under a single schema, which may then …

Objective Computation Versus Subjective Computation, Nir Fresco

Faculty of Engineering and Information Sciences - Papers: Part A

The question ‘What is computation?’ might seem a trivial one to many, but this is far from being in consensus in philosophy of mind, cognitive science and even in physics. The lack of consensus leads to some interesting, yet contentious, claims, such as that cognition or even the universe is computational. Some have argued, though, that computation is a subjective phenomenon: whether or not a physical system is computational, and if so, which computation it performs, is entirely a matter of an observer choosing to view it as such. According to one view, which we dub bold anti-realist pancomputationalism, every …

Friction And Anti-Wear Property Of Aqueous Tri-Block Copolymer Solutions In Metal Forming, Buyung Kosasih, Oyong Novareza, A Kiet Tieu, Hongtao Zhu

Faculty of Engineering and Information Sciences - Papers: Part A

Friction and anti-wear property of aqueous symmetrical tri-block normal PEOm-PPOn-PEOm and reverse PPOn-PEOm-PPOn copolymer solutions have been studied. The study focuses on the effect of the solution bulk temperatures and the copolymer block structures. It was found that the concentration and the length of the copolymer blocks affect the solution cloud points, friction and anti-wear property. When solution was supplied at bulk temperature above their cloud point, aqueous copolymer solutions were not able to develop effective adsorbed film resulting in high friction and severe wear. When the bulk temperatures were below the cloud point, the anti-wear property improved significantly and …