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Full-Text Articles in Engineering
Silicon Monoxide-A Convenient Precursor For Large Scale Synthesis Of Near Infrared Emitting Monodisperse Silicon Nanocrystals, Wei Sun, Chenxi Qian, Xiao Sherri Cui, Liwei Wang, Muan Wei, Gilberto Casillas, Amr S. Helmy, Geoffrey A. Ozin
Silicon Monoxide-A Convenient Precursor For Large Scale Synthesis Of Near Infrared Emitting Monodisperse Silicon Nanocrystals, Wei Sun, Chenxi Qian, Xiao Sherri Cui, Liwei Wang, Muan Wei, Gilberto Casillas, Amr S. Helmy, Geoffrey A. Ozin
Australian Institute for Innovative Materials - Papers
While silicon nanocrystals (ncSi) embedded in silicon dioxide thin films have been intensively studied in physics, the potential of batch synthesis of silicon nanocrystals from the solid-state disproportionation of SiO powder has not drawn much attention in chemistry. Herein we describe some remarkable effects observed in the diffraction, microscopy and spectroscopy of SiO powder upon thermal processing in the temperature range 850-1100 °C. Quantum confinement effects and structural changes of the material related to the size of the silicon nanocrystals nucleated and grown in this way were established by Photoluminescence (PL), Raman, FTIR and UV-Visible spectroscopy, PXRD and STEM, pinpointing …
A Green And Facile Way To Prepare Granadilla-Like Silicon-Based Anode Materials For Li-Ion Batteries, Lei Zhang, Ranjusha Rajagopalan, Haipeng Guo, Xianluo Hu, S X. Dou, Hua-Kun Liu
A Green And Facile Way To Prepare Granadilla-Like Silicon-Based Anode Materials For Li-Ion Batteries, Lei Zhang, Ranjusha Rajagopalan, Haipeng Guo, Xianluo Hu, S X. Dou, Hua-Kun Liu
Australian Institute for Innovative Materials - Papers
A yolk-shell-structured carbon@void@silicon (CVS) anode material in which a void space is created between the inside silicon nanoparticle and the outer carbon shell is considered as a promising candidate for Li-ion cells. Untill now, all the previous yolk-shell composites were fabricated through a templating method, wherein the SiO2 layer acts as a sacrificial layer and creates a void by a selective etching method using toxic hydrofluoric acid. However, this method is complex and toxic. Here, a green and facile synthesis of granadilla-like outer carbon coating encapsulated silicon/carbon microspheres which are composed of interconnected carbon framework supported CVS nanobeads is reported. …
Beam Perturbation Characteristics Of A 2d Transmission Silicon Diode Array, Magic Plate, Z A. Alrowaili, Michael L. F Lerch, Marco Petasecca, Martin Carolan, Peter E. Metcalfe, Anatoly B. Rosenfeld
Beam Perturbation Characteristics Of A 2d Transmission Silicon Diode Array, Magic Plate, Z A. Alrowaili, Michael L. F Lerch, Marco Petasecca, Martin Carolan, Peter E. Metcalfe, Anatoly B. Rosenfeld
Faculty of Engineering and Information Sciences - Papers: Part A
The main objective of this study is to demonstrate the performance characteristics of the Magic Plate (MP) system when operated upstream of the patient in transmission mode (MPTM). The MPTM is an essential component of a real-time QA system designed for operation during radiotherapy treatment. Of particular interest is a quantitative study into the influence of the MP on the radiation beam quality at several field sizes and linear accelerator potential differences. The impact is measured through beam perturbation effects such as changes in the skin dose and/or percentage depth dose (PDD) (both in and out of field). The MP …
Reduction Of Quartz To Silicon Monoxide By Methane-Hydrogen Mixtures, Xiang Li, Guangqing Zhang, Ragnar Tronstad, Oleg Ostrovski
Reduction Of Quartz To Silicon Monoxide By Methane-Hydrogen Mixtures, Xiang Li, Guangqing Zhang, Ragnar Tronstad, Oleg Ostrovski
Faculty of Engineering and Information Sciences - Papers: Part A
The reduction of quartz was studied isothermally in a fluidized bed reactor using continuously flowing methane-hydrogen gas mixture in the temperature range from 1623 K to 1773 K (1350 °C to 1500 °C). The CO content in the off-gas was measured online using an infrared gas analyzer. The main phases of the reduced samples identified by XRD analysis were quartz and cristobalite. Significant weight loss in the reduction process indicated that the reduction products were SiO and CO. Reduction of SiO2 to SiO by methane starts with adsorption and dissociation of CH4 on the silica surface. The high carbon activity …
Rapid Transformation Of Hexagonal To Cubic Silicon Carbide (Sic) By Electric Discharge Assisted Mechanical Milling, Iis Siti Aisyah, Monika Wyszomirska, Andrzej Calka, David Wexler
Rapid Transformation Of Hexagonal To Cubic Silicon Carbide (Sic) By Electric Discharge Assisted Mechanical Milling, Iis Siti Aisyah, Monika Wyszomirska, Andrzej Calka, David Wexler
Faculty of Engineering and Information Sciences - Papers: Part A
Silicon carbide powder was successfully transformed from hexagonal SiC into cubic SiC using the electric discharge assisted mechanical milling (EDAMM) method. The milling process was conducted in nitrogen plasma at atmospheric pressure. The effects of pulsed alternating current (AC) and direct current (DC) discharge on product formation were investigated. Products were characterized by X-ray diffractometry, scanning electron microscopy, transmission electron microscopy and nanohardness. It was found that hexagonal SiC can be transformed into cubic SiC under EDAMM processing, near complete transformation occurring within 5 min when applying AC mode electrical pulses, and within 10 min when applying DC mode discharges.
Characterisation Of A Cobalt-60 Small-Beam Animal Irradiator Using A Realtime Silicon Pixelated Detector, C Porumb, Jocelyn Davies, Vladimir Perevertaylo, Anatoly B. Rosenfeld, Marco Petasecca
Characterisation Of A Cobalt-60 Small-Beam Animal Irradiator Using A Realtime Silicon Pixelated Detector, C Porumb, Jocelyn Davies, Vladimir Perevertaylo, Anatoly B. Rosenfeld, Marco Petasecca
Faculty of Engineering and Information Sciences - Papers: Part A
The paper presents a study performed by the Centre for Medical Radiation Physics (CMRP) using a high spatial and temporal resolution silicon pixelated detector named MagicPlate- 512. The study focuses on the characterisation of three pencil beams from a low-dose rate, 6 TBq, cobalt-60 source, in terms of percentage depth dose, beam profiles, output factor and shutter timing. Where applicable, the findings were verified against radiochromic EBT3 film and ionization chambers. It was found that the results of the MagicPlate-512 and film agreed within 0.9 mm for penumbra and full-width at half-maximum measurements of the beam profiles, and within 0.75% …
Characterisation Of Silicon Diode Arrays For Dosimetry In External Beam Radiation Therapy, Claudiu S. Porumb, Abdullah H. Aldosari, Iolanda Fuduli, Dean L. Cutajar, Matthew Newall, Peter E. Metcalfe, Martin G. Carolan, Michael L. F Lerch, Vladimir Perevertaylo, Anatoly B. Rosenfeld, Marco Petasecca
Characterisation Of Silicon Diode Arrays For Dosimetry In External Beam Radiation Therapy, Claudiu S. Porumb, Abdullah H. Aldosari, Iolanda Fuduli, Dean L. Cutajar, Matthew Newall, Peter E. Metcalfe, Martin G. Carolan, Michael L. F Lerch, Vladimir Perevertaylo, Anatoly B. Rosenfeld, Marco Petasecca
Faculty of Engineering and Information Sciences - Papers: Part A
Modern stereotactic radiation therapy modalities utilize small beams and large dose gradients to deliver radiation in few fractions, reducing the possibility to correct for mistakes during the treatment process. Therefore, in order to ensure best possible treatment for the patient, quality assurance for such treatments necessitates a stable, linear, and sensitive radiation detector with high spatial resolution and radiation hardness. In this work, two silicon detector arrays with high spatial resolution have been characterized by 6 MV and 18 MV medical LINAC irradiation, and 5.5 MeV He2+ heavy ion microprobe. A maximum discrepancy of 0.6 mm in field size has …
Cationic Silicon Nanocrystals With Colloidal Stability, Ph-Independent Positive Surface Charge And Size Tunable Photoluminescence In The Near-Infrared To Red Spectral Range, Kenneth K. Chen, Kristine Liao, Gilberto Casillas, Yiying Li, Geoffrey A. Ozin
Cationic Silicon Nanocrystals With Colloidal Stability, Ph-Independent Positive Surface Charge And Size Tunable Photoluminescence In The Near-Infrared To Red Spectral Range, Kenneth K. Chen, Kristine Liao, Gilberto Casillas, Yiying Li, Geoffrey A. Ozin
Australian Institute for Innovative Materials - Papers
In this report, the synthesis of a novel class of cationic quaternary ammonium-surface-functionalized silicon nanocrystals (ncSi) using a novel and highly versatile terminal alkyl halide-surface-functionalized ncSi synthon is described. The distinctive features of these cationic ncSi include colloidal stability, pH-independent positive surface charge, and size-tunable photoluminescence (PL) in the biologically relevant near-infrared-to-red spectral region. These cationic ncSi are characterized via a combination of high-resolution scanning transmission electron microscopy with energy-dispersive X-ray analysis, Fourier transform infrared, X-ray photoelectron, and photoluminescence spectroscopies, and zeta potential measurements.
Light Activated Electrochemistry: Light Intensity And Ph Dependence On Electrochemical Performance Of Anthraquinone Derivatized Silicon, Ying Yang, Simone Ciampi, Moinul H. Choudhury, J Justin Gooding
Light Activated Electrochemistry: Light Intensity And Ph Dependence On Electrochemical Performance Of Anthraquinone Derivatized Silicon, Ying Yang, Simone Ciampi, Moinul H. Choudhury, J Justin Gooding
Australian Institute for Innovative Materials - Papers
We seek to understand how the thermodynamics and kinetics of anthraquinone-containing self-assembled monolayer on silicon electrodes are affected by two key experimental variables: the intensity of the light assisting the anthraquinone/anthrahydroquinone redox process and the local solution environment. The substrates are chemically passivated poorly doped p-type silicon electrodes. The study presents a strategy for the selective modulation of either the anodic or the cathodic process occurring at the interface. Cyclic voltammetry studies showed that unlike for a proton-coupled electron transfer process performed at metallic electrodes, for the redox reaction of the anthraquinone unit on a silicon electrode it becomes possible …