Physical Sciences and Mathematics Commons^™

Workshop | Body Worn Video Recorders: The Socio-Technical Implications Of Gathering Direct Evidence, Katina Michael, Alexander Hayes

Alexander Hayes Mr.

- From in-car video recording to body-worn video recording

- Exploring available technologies: how do they work, pros and cons

- Storing direct evidence in secure storage: factors to consider

- Citizens “shooting” back with POV tech – what are their rights?

- Crowdsourced sousveillance- harnessing public data for forensic profiling

- Police force policies and practices on the application of new media

A Novel Weighted-Graph-Based Grouping Algorithm For Metadata Prefetching, Peng Gu, Jun Wang, Yifeng Zhu, Hong Jiang, Pengju Shang

Yifeng Zhu

Although data prefetching algorithms have been extensively studied for years, there is no counterpart research done for metadata access performance. Existing data prefetching algorithms, either lack of emphasis on group prefetching, or bearing a high level of computational complexity, do not work well with metadata prefetching cases. Therefore, an efficient, accurate, and distributed metadata-oriented prefetching scheme is critical to leverage the overall performance in large distributed storage systems. In this paper, we present a novel weighted-graph-based prefetching technique, built on both direct and indirect successor relationship, to reap performance benefit from prefetching specifically for clustered metadata servers, an arrangement envisioned …

Facies And Reservoir Characterization Of The Permian White Rim Sandstone, Black Box Dolomite, And Black Dragon Member Of The Triassic Moenkopi Formation For Co2 Storage And Sequestration At Woodside Field, East-Central Utah, Walter Andrew Harston

Theses and Dissertations

Geologic sequestration of anthropogenic carbon dioxide (CO2) greenhouse gas emissions is an engineering solution that potentially reduces CO2 emissions released into the atmosphere thereby limiting their effect on climate change. This study focuses on Woodside field as a potential storage and sequestration site for CO2 emissions. The Woodside field is positioned on a doubly plunging, asymmetrical anticline on the northeast flank of the San Rafael Swell. Particular focus will be placed on the Permian White Rim Sandstone, Black Box Dolomite and Black Dragon Member of the Triassic Moenkopi Formation as the reservoir/seal system to store and sequester CO2 at Woodside …

Software Techniques To Reduce The Energy Consumption Of Low-Power Devices At The Limits Of Digital Abstractions, Mastooreh Salajegheh

Open Access Dissertations

My thesis explores the effectiveness of software techniques that bend digital abstractions in order to allow embedded systems to do more with less energy. Recent years have witnessed a proliferation of low-power embedded devices with power ranges of few milliwatts to microwatts. The capabilities and size of the embedded systems continue to improve dramatically; however, improvements in battery density and energy harvesting have failed to mimic a Moore's law. Thus, energy remains a formidable bottleneck for low-power embedded systems.

Instead of trying to create hardware with ideal energy proportionality, my dissertation evaluates how to use unconventional and probabilistic computing that …

Reduced Graphene Oxide With Superior Cycling Stability And Rate Capability For Sodium Storage, Yunxiao Wang, Shulei Chou, Hua-Kun Liu, S X. Dou

Australian Institute for Innovative Materials - Papers

Sodium ion battery is a promising electrical energy storage system for sustainable energy storage applications due to the abundance of sodium resources and their low cost. In this communication, the electrochemical properties of sodium ion storage in reduced graphene oxide (RGO) were studied in an electrolyte consisting of 1 M NaClO4 in propylene carbonate (PC). The experimental results show that the RGO anode allowed significant sodium ion insertion, leading to higher capacity at high current density compared to the previously reported results for carbon materials. This is due to the fact that RGO possesses higher electrical conductivity and is a …

Synthesis Of Hollow Geo2 Nanostructures, Transformation Into Geoc, And Lithium Storage Properties, Li Li, Kuok H. Seng, Chuanqi Feng, Hua-Kun Liu, Zaiping Guo

Australian Institute for Innovative Materials - Papers

In this work, we synthesize mesoporous and hollow germanium@carbon nanostructures through simultaneous carbon coating and reduction of a hollow ellipsoidal GeO2 precursor. The formation mechanism of GeO 2 ellipsoids and the ratio of Ge4+ to Sn4+ as the starting materials are also investigated. Compared to the solid ellipsoidal Ge@carbon (Ge@C-3), the hollow ellipsoidal Ge@C-1 sample exhibits better cycling stability (100% capacity retention after 200 cycles at the 0.2 C rate) and higher rate capability (805 mA h g-1 at 20 C) compared to Ge@C-3 due to its unique hollow structure; therefore, this hollow ellipsoidal Ge@carbon can be considered as a …

A Facile Route To Synthesize Transition Metal Oxide/Reduced Graphene Oxide Composites And Their Lithium Storage Performance, Chongjun Zhao, Shulei Chou, Yunxiao Wang, Cuifeng Zhou, Hua-Kun Liu, S X. Dou

Australian Institute for Innovative Materials - Papers

Transition metal oxide (Mn3O4, Fe2O3, Co3O4, and ZnO) and reduced graphene oxide (RGO) composites were successfully synthesized via a hydrothermal method using the direct reaction between the corresponding metal powder and graphene oxide (GO). In this process, the GO can be reduced by transition metal powder in water, and the nanosized metal oxide can be obtained, and homogeneously mixed with and wrapped by RGO to form a metal oxide/RGO composite at the same time. X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, and scanning and transmission electron microscopy were used to characterize the as-prepared materials. The different experimental parameters, including reactants, …

An Overview - Functional Nanomaterials For Lithium Rechargeable Batteries, Supercapacitors, Hydrogen Storage, And Fuel Cells, Hua-Kun Liu

Australian Institute for Innovative Materials - Papers

There is tremendous worldwide interest in functional nanostructured materials, which are the advanced nanotechnology materials with internal or external dimensions on the order of nanometers. Their extremely small dimensions make these materials unique and promising for clean energy applications such as lithium ion batteries, supercapacitors, hydrogen storage, fuel cells, and other applications. This paper will highlight the development of new approaches to study the relationships between the structure and the physical, chemical, and electrochemical properties of functional nanostructured materials. The Energy Materials Research Programme at the Institute for Superconducting and Electronic Materials, the University of Wollongong, has been focused on …

A Hybrid Electrolyte Energy Storage Device With High Energy And Long Life Using Lithium Anode And Mno2 Nanoflake Cathode, Shulei Chou, Yun-Xiao Wang, Jiantie Xu, Jia-Zhao Wang, Hua-Kun Liu, S X. Dou

Australian Institute for Innovative Materials - Papers

A hybrid electrolyte energy storage system combining the features of supercapacitors and lithium batteries has been constructed. It consists of MnO2 nanoflakes in 1 M Li2SO4 aqueous electrolyte as the cathode and lithium foil in ionic liquid (1 M lithium bis(trifluoromethanesulfonyl)imide (LiNTf2) in N-methyl-N-propyl pyrrolidinium bis(trifluoromethanesulfonyl)imide ([C(3)mpyr][NTf2])) electrolyte as the anode, separated by a lithium super ionic conductor glass ceramic film (LiSICON). This system shows the advantages of both a supercapacitor (long cycle life) and a lithium battery (high energy), as well as low cost and improved safety due to the combination of ionic liquid and ceramic solid state electrolyte …

Highly Uniform Tio2/Sno2/Carbon Hybrid Nanofibers With Greatly Enhanced Lithium Storage Performance, Zunxian Yang, Qing Meng, Zaiping Guo, Xuebin Yu, Tailiang Guo, Rong Zeng

Australian Institute for Innovative Materials - Papers

Highly uniform, relatively large area TiO2/SnO 2/carbon hybrid nanofibers were synthesized by a simple method based on thermal pyrolysis and oxidation of an as-spun titanium-tin/polyacrylonitrile nanoweb composite in an argon atmosphere. This novel composite features the uniform dispersion and encapsulation of highly uniform nanoscale TiO 2/SnO2 crystals in a porous carbon matrix. The high porosity of the nanofiber composite material, together with the conductive carbon matrix, enhanced the electrochemical performance of the TiO 2/SnO2/carbon nanofiber electrode. The TiO 2/SnO2/carbon nanofiber electrode displays a reversible capacity of 442.8 mA h g-1 for up to 100 cycles, and exhibits excellent rate capability. …

The Effects Of Fec (Fluoroethylene Carbonate) Electrolyte Additive On The Lithium Storage Properties Of Nio (Nickel Oxide) Nanocuboids, Kuok H. Seng, Li Li, Dapeng Chen, Zhixin Chen, Xiaolin Wang, Hua-Kun Liu, Zaiping Guo

Australian Institute for Innovative Materials - Papers

Nanocuboid shaped NiO (nickel oxide) has been synthesized using an optical floating zone furnace. It was found that the nanocuboids exhibit single crystalline nature, and have clean and sharp edges. Furthermore, the NiO nanocuboids were tested for their electrochemical performances as anode material for LIBs (lithium-ion batteries) in a coin-type half cell. The effects of FEC (fluoroethylene carbonate) additive on the lithium storage performance were also investigated, which is the first of such studies for transition metal oxides. It was found that FEC has a positive effect on the cycling stability and also improves the rate performances of the nanocuboids. …

Simply Mixed Commercial Red Phosphorus And Carbon Nanotube Composite With Exceptionally Reversible Sodium-Ion Storage, Wei-Jie Li, Shulei Chou, Jia-Zhao Wang, Hua-Kun Liu, S X. Dou

Australian Institute for Innovative Materials - Papers

Recently, sodium ion batteries (SIBs) have been given intense attention because they are the most promising alternative to lithium ion batteries for application in renewable power stations and smart grid, owing to their low cost, their abundant natural resources, and the similar chemistry of sodium and lithium. Elemental phosphorus (P) is the most promising anode materials for SIBs with the highest theoretical capacity of 2596 mA h g-1, but the commercially available red phosphorus cannot react with Na reversibly. Here, we report that simply hand-grinding commercial microsized red phosphorus and carbon nanotubes (CNTs) can deliver a reversible capacity of 1675 …

Tubular Graphitic-C 3 N 4 : A Prospective Material For Energy Storage And Green Photocatalysis, Muhammad Nawaz Tahir, Chuanbao Cao, Faheem K. Butt, Faryal Idrees, Nasir Mahmood, Zulfiqar Ali, Imran Aslam, M Tanveer, Muhammad Rizwan, Tariq Mahmood

Australian Institute for Innovative Materials - Papers

We have established a facile and scaleable approach to fabricate tubular graphitic-C3N4 using melamine. The construction of the unique tubular morphology is a result of the pre-treatment of melamine with HNO3. Herein, for the first time, we have explored the electrochemical properties of g-C3N4 as an electrode material for supercapacitors. Tubular g-C3N4 has significant advantages due to its distinctive morphology, high surface area (182.61 m² g^-1) and combination of carbon with nitrogen. Therefore, tubular g-C3N4 demonstrated a good specific capacitance of 233 F g^-1 at a current density of 0.2 A g^-1 in 6 M …