Engineering Commons^™

High-Throughput Production Of Uniformly Sized Liquid Metal Microdroplets Using Submerged Electrodispersion, Yuxin Zhang, Shiyang Tang, Qianbin Zhao, Guolin Yun, Dan Yuan, Weihua Li

Faculty of Engineering and Information Sciences - Papers: Part B

Microdroplets of gallium-based liquid metal alloys have enabled various applications in the fields of biomedicine, electronics, and chemistry. However, due to the high surface tension of liquid metal, high-throughput production of uniformly sized liquid metal microdroplets is challenging using conventional acoustic or microfluidic methods. Here, adapting the submerged electrodispersion technique that has conventionally been used for generating water-based microdroplets, we develop a simple and straightforward platform for the high-throughput production of near-monodisperse (coefficient of variation less than 5%) liquid metal microdroplets in oil without using microfluidic devices. We demonstrate the capabilities of this method for producing liquid metal microdroplets (diameters …

Performance Evaluation Of Non-Gps Based Localization Techniques Under Shadowing Effects, Ngoc M. Nguyen, Le Chung Tran, Farzad Safaei, Son Lam Phung, Peter James Vial, Nam N. Huynh, Anne N. Cox, Theresa Harada, Johan Barthelemy

Faculty of Engineering and Information Sciences - Papers: Part B

Non-GPS localization has gained much interest from researchers and industries recently because GPS might fail to meet the accuracy requirements in shadowing environments. The two most common range-based non-GPS localization methods, namely Received Signal Strength Indicator (RSSI) and Angle-of-Arrival (AOA), have been intensively mentioned in the literature over the last decade. However, an in-depth analysis of the weighted combination methods of AOA and RSSI in shadowing environments is still missing in the state-of-the-art. This paper proposes several weighted combinations of the two RSSI and AOA components in the form of pAOA + qRSSI, devises the mathematical model for analyzing shadowing …

Thread Effects On The Stiffness Of Bolted Shear Connections, Aziz Ahmed, Lip H. Teh

Faculty of Engineering and Information Sciences - Papers: Part B

This paper investigates the effects of bolt threads on the initial and final stiffnesses of double-shear bolted connections through laboratory tests and finite element (FE) analyses. Nineteen specimens composed of 4.7 mm and 8.0 mm thick structural steel plates with bolt diameters of 20 mm and 30 mm having varying end distances are studied. The investigation, which involves shank and thread bolted connections, has found that the threads reduce the initial stiffness but increase the final stiffness. The FE analysis shows that the reduction in the initial stiffness is due to the bolt threads cutting into the connected plate, increasing …

Contradictions In Information Technology Mediated Work In Long-Term Care: An Activity Theoretic Ethnographic Study, Siyu Qian, Ping Yu, Anol Bhattacherjee

Faculty of Engineering and Information Sciences - Papers: Part B

Background: The growing demand for aged care services coupled with a global shortage of skilled nursing staff has hindered long-term care facilities' ability to provide necessary services to their residents. Healthcare information technology is expected to mitigate this challenge by streamlining nursing work, while also improving quality of care and productivity.

Objectives: This study set out to examine how nurses and care workers work, the role of information technology (IT) in their work and what contradictions they face in their IT mediated work.

Design: Ethnographic study informed by six components of activity theory: subject, object, tool, rule, …

Characterisations Of A Fibre Optic Dosimetry System For Source Tracking During Hdr Brachytherapy, Mohammed Al Towairqi, Dean L. Cutajar, Terry Braddock, Enbang Li, S Wadi-Ramahi, Belal Moftah, Anatoly B. Rosenfeld

Faculty of Engineering and Information Sciences - Papers: Part B

Brachytherapy is a complex treatment procedure where radioactive sources are inserted in or close to the tumours to destroy the cancerous cells. Due to the unique properties of scintillation plastic detectors, this study was aimed to characterise an innovative fibre optic dosimetry system as a quality assurance tool during HDR Brachytherapy. Scintillating plastic fibres with different scintillation lengths were prepared and then optically coupled to non-scintillating fibres for light transmission. A transimpedance photodiode amplifier was used to detect positional sensitivities of different fibre probes placed within a solid-water phantom at varying distances above an 192-Ir brachytherapy source located within the …

Creep In Primary Consolidation With Rate Of Loading Approach, Gang Bi, Shua Ni, Dong Wang, Yeqiang Chen, Jianfei Wei, Wenzong Gong

Faculty of Engineering and Information Sciences - Papers: Part B

The debate on creep in primary consolidation is analysed with a power law model following an approach in which creep is considered as rate of loading. According to this approach, primary consolidation is one type of rate of loading. To verify this approach, two types of tests, standard oedometer test and oedometer test with drainage prevented, are conducted on three types of soils (two from NGES and the other from Port of Guangzhou). The result: creep exponents obtained from two kinds of tests agree well with each other. Moreover, the approach is further validated by tracking, for over 80 years, …

Coffee-An Mpi-Parallelized Python Package For The Numerical Evolution Of Differential Equations, George Doulis, Jorg Frauendiener, Chris Stevens, Benjamin E. Whale

Faculty of Engineering and Information Sciences - Papers: Part B

COFFEE (Conformal Field Equation Evolver) is a Python package primarily developed to numerically evolve systems of partial differential equations over time using the method of lines. It includes a variety of time integrators and finite differencing stencils with the summation-by-parts property, as well as pseudo-spectral functionality for angular derivatives of spin-weighted functions. Some additional capabilities include being MPI-parallelisable on a variety of different geometries, HDF data output and post processing scripts to visualize data, and an actions class that allows users to create code for analysis after each timestep.

Fire-Resistance Of Eccentrically Loaded Rectangular Concrete-Filled Steel Tubular Slender Columns Incorporating Interaction Of Local And Global Buckling, Ghanim Mohammed Kamil, Qing Quan Liang, Muhammad N. S Hadi

Faculty of Engineering and Information Sciences - Papers: Part B

A mathematical model using the fiber approach is presented in this paper for quantifying the strength and fire-resistance of eccentrically loaded slender concrete-filled steel tubular (CFST) columns with rectangular sections incorporating the interaction of local and global buckling. The model utilizes the thermal simulator to ascertain the temperature distribution in cross-sections, and the nonlinear global buckling analysis to predict the interaction responses of local and global buckling of loaded CFST slender columns to fire effects. The initial geometric imperfection, air gap between the concrete and steel tube, tensile concrete strength, deformations caused by preloads, and temperature-dependent material behavior are included …

Boundaries, Spectral Triples And K-Homology, Iain G. Forsyth, Magnus Goffeng, Bram Mesland, Adam C. Rennie

Faculty of Engineering and Information Sciences - Papers: Part B

This paper extends the notion of a spectral triple to a relative spectral triple, an unbounded analogue of a relative Fredholm module for an ideal J◃A. Examples include manifolds with boundary, manifolds with conical singularities, dimension drop algebras, θ-deformations and Cuntz–Pimsner algebras of vector bundles.

The bounded transform of a relative spectral triple is a relative Fredholm module, making the image of a relative spectral triple under the boundary mapping in K-homology easy to compute. We introduce an additional operator called a Clifford normal with which a relative spectral triple can be doubled into a spectral triple.

The Clifford normal …

Influences Of Load And Microstructure On Tribocorrosion Behaviour Of High Strength Hull Steel In Saline Solution, Hui Wu, Yan Li, Zhou Li, Xiawei Cheng, Mahadi Hasan, Hongmei Zhang, Zhengyi Jiang

Faculty of Engineering and Information Sciences - Papers: Part B

The tribocorrosion behaviour of two diferent hull steels (namely, EH36 and EH47) was investigated using a ball-on-disk tribometer under varying normal loads from 10 to 100 N in a 3.5 wt% NaCl saline solution. Sliding in pure water was also performed for a comparison purpose. The results indicate that the corrosion products mainly consist of lath lepidocrocite (γ-FeOOH) with residual NaCl crystals when sliding against both steels EH36 and EH47 in the saline solution. Tribocorrosion on EH36 (pearlitic steel) shows lower coefcient of friction (COF) values than those obtained in water, while tribocorrosion on EH47 (bainitic steel) leads to higher …

Theoretical Study On Positron Scattering By Benzene Over A Broad Energy Range, Alessandra Souza Barbosa, Francisco Blanco, Gustavo Garcia, Marcio H. F. Bettega

Faculty of Engineering and Information Sciences - Papers: Part B

In this paper two theoretical methodologies, the Schwinger multichannel (SMC) method and the independent atom model with the screening corrected additivity rule (IAM-SCAR), were employed to study positron scattering by benzene over a broad impact energy range. The SMC calculations were carried out in the static plus polarization approximation, accounting for the elastic channel, for impact energies up to 20 eV. The IAM-SCAR method covered energies up to 1000 eV to provide total, elastic, ionization, excitation, and positronium formation cross sections. In the low-energy region we discuss how the description of the polarization effects affects the cross sections. In particular, …

Effects Of Grain Boundary On Wear Of Graphene At The Nanoscale: A Molecular Dynamics Study, Jie Zhang, Xinchun Chen, Qiang Xu, Tianbao Ma, Yuanzhong Hu, Hui Wang, Anh Kiet Tieu, Jianbin Luo

Faculty of Engineering and Information Sciences - Papers: Part B

Graphene has shown excellent tribological behaviors, enabling its potential applications as lubricating and anti-wear coatings, however, the grain boundaries (GBs) formed during the preparation process may deteriorate the performance of graphene. Using large-scale molecular dynamics simulations, we study the wear mechanism of graphene GBs with various misorientation angles between two grains. Compared with pure nanoindentation at the GBs, the critical load of wear failure upon nanoscratching across the GBs is much lower due to the synergetic actions of interlocking and pushing between the tip and graphene atoms. The misorientation angle between the adjacent grains significantly effects the onset and fashion …