Physical Sciences and Mathematics Commons^™

Effects Of Disorder On Thermoelectric Properties Of Semiconducting Polymers, Zlatan Aksamija, Dhandapani Venkataraman, Connor J. Boyle, Meenakshi Upadhyaya

Zlatan Aksamija

Gravitationally Induced Quantum Superposition Reduction With Large Extra Dimensions, Jonas R. Mureika

Jonas Mureika

A gravity-driven mechanism (``objective reduction'') proposed to explain quantum state reduction is analyzed in light of the possible existence of large extra dimensions in the ADD scenario. By calculating order-of-magnitude estimates for nucleon superpositions, it is shown that if the mechanism at question is correct, constraints may be placed on the number and size of extra dimensions. Hence, measurement of superposition collapse times ({\it e.g.} through diffraction or reflection experiments) could represent a new probe of extra dimensions. The influence of a time-dependent gravitational constant on the gravity-driven collapse scheme with and without the presence of extra dimensions is also …

Biological Aggregation Driven By Social And Environmental Factors: A Nonlocal Model And It Degenerate Cahn-Hilliard Approximation, Andrew J. Bernoff, Chad Topaz

Chad M. Topaz

No abstract provided.

Scheduling Instruction Effects For A Statically Pipelined Processor, F. Rasapour, G. Cook, G.-R. Uh

Gang-Ryung Uh

Statically pipelined processors have a fully exposed datapath where all portions of the pipeline are directly controlled by effects within an instruction, which simplifies hardware and enables a new level of compiler optimizations. This paper describes an effect scheduling strategy to aggressively compact instructions, which has a critical impact on code size and performance. Unique scheduling challenges include more frequent name dependences and fewer renaming opportunities due to static pipeline (SP) registers being dedicated for specific operations. We also realized the SP in a hardware implementation language (VHDL) to evaluate the real energy benefits. Despite the compiler challenges, we achieve …

Development Without Energy? Assessing Future Scenarios Of Energy Consumption In Developing Countries, Jan Steckel, Robert Brecha, Michael Jakob, Jessica Strefler, Gunnar Luderer

Robert J. Brecha

We analyze the relationship between economic development and energy consumption in the context of greenhouse gas mitigation. The main contribution of this work is to compare estimates of energy thresholds in the form of minimum energy requirements to reach high levels of development with output projections of per capita final energy supply from a group of integrated assessment models (IAMs). Scenarios project that reductions of carbon emissions in developing countries will be achieved not only by means of decreasing the carbon intensity, but also by making a significant break with the historically observed relationship between energy use and economic growth. …

2014-15 Central West State Of The Environment Report, Neil Dufty

Neil Dufty

Carbon Nanotube-Reduced Graphene Oxide Composites For Thermal Energy Harvesting Applications, Mark S. Romano, Na Li, Dennis Antiohos, Joselito M. Razal, Andrew Nattestad, Stephen Beirne, Shaoli Fang, Yongsheng Chen, Rouhollah Jalili, Gordon G. Wallace, Ray Baughman, Jun Chen

Gordon Wallace

By controlling the SWNT-rGO electrode composition and thickness to attain the appropriate porosity and tortuosity, the electroactive surface area is maximized while rapid diffusion of the electrolyte through the electrode is maintained. This leads to an increase in exchange current density between the electrode and electrolyte which results in enhanced thermocell performance.

Novel Nanographene/Porphyrin Hybrids-Preparation, Characterization, And Application In Solar Energy Conversion Schemes, Daniel Kiessling, Ruben D. Costa, Georgios Katsukis, Jenny Malig, Fabian Lodermeyer, Sebastian Feihl, Alexandra Roth, Leonie Wibmer, Matthias Kehrer, Michel Volland, Pawel W. Wagner, Gordon G. Wallace, David L. Officer, Dirk M. Guldi

Gordon Wallace

Four novel nanographene/porphyrin hybrids were prepared, characterized, and probed in solar energy conversion schemes. Exfoliation of graphite by means of immobilizing four different porphyrins onto the basal plane of graphene is accompanied by distinct electronic interactions in both the ground and the excited states. In the ground state, a strong loss in oscillator strength goes hand-in-hand with a notable broadening of the porphyrin transitions and, as such, attests to the shift of electron density from the electron donating porphyrins to nanographene. In the excited state, a nearly quantitative quenching of the porphyrin fluorescence is indicative of full charge transfer. The …

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

Shi Xue Dou

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 …

Finite Molecular Anchoring In The Escaped-Radial Nematic Configuration: A 2-H-Nmr Study, G. P. Crawford, David W. Allender, J. William Doane, M. Vilfan, I. Vilfan

David W Allender

The director-field configuration of a nematic liquid crystal confined to cylindrical cavities of polycarbonate Nuclepore membranes ranging from 0.3 to 0.05-mu-m in radius is determined using deuterium nuclear magnetic resonance (H-2 NMR). Spectral patterns from cavities of radius 0.3-mu-m reveal the escaped-radial configuration with singular point defects, but as the cylinder size is decreased, the elastic energy imposed by the curvature of the confining walls competes with the anchoring energy to tilt the directors away from their preferred perpendicular anchoring direction, preventing the expected transition to the planar-radial configuration. A surface fitting parameter is directly determined by simulating H-2-NMR line …

Electron Energy Dependent Charging Effects Of Multilayered Dielectric Materials, Gregory Wilson, Jr Dennison, Amberly Evans, Justin Dekany

Gregory Wilson

Measurements of the charge distribution in electron-bombarded, thin-film, multilayer dielectric samples showed that charging of multilayered materials evolves with time and is highly dependent on incident energy; this is driven by electron penetration depth, electron emission and material conductivity. Based on the net surface potential’s dependence on beam current, electron range, electron emission and conductivity, measurements of the surface potential, displacement current and beam energy allow the charge distribution to be inferred. To take these measurements, a thin-film disordered SiO2 structure with a conductive middle layer was charged using 200 eV and 5 keV electron beams with regular 15 s …

Approximation Of Range In Materials As A Function Of Incident Electron Energy, Gregory Wilson, Jr Dennison

Gregory Wilson

A simple composite analytic expression has been developed to approximate the electron range in materials. The expression is applicable over more than six orders of magnitude in energy (<10 eV to >10 MeV) and range (10-9 m to 10-2 m), with uncertainty of ≤20% for most conducting, semiconducting and insulating materials. This is accomplished by fitting data from two standard NIST databases [ESTAR for the higher energy range and the electron IMFP (inelastic mean free path) for the lower energies]. In turn, these data have been fit with well-established semi-empirical models for range and IMFP that are related to standard materials properties …

Comment On The Ionization Energy Of B2f4, Bun Chan, Adam J. Trevitt, Stephen J. Blanksby, Leo Radom

Adam Trevitt

The Gn test sets(1) of accurate (uncertainty ≤ 1 kcal mol–1 ≈ 4 kJ mol–1) experimental data are widely employed in the development and assessment of quantum chemistry procedures. However, while all the data in the Gn sets nominally carry a sub-kcal mol–1 uncertainty, several of the experimental values show uncharacteristically large discrepancies when compared with values determined by high-level theoretical calculations. One of these questionable values is the adiabatic ionization energy (IE) of B2F4, for which the theoretical values calculated, for example, with the high-level G2 (1133.9, kJ mol–1),(1b) G3 (1135.4 kJ mol–1),(2) and G4 (1127.2 kJ mol–1)(3) procedures …

Advanced Microwave-Assisted Production Of Hybrid Electrodes For Energy Applications, Peter Sherrell, Jun Chen, Joselito M. Razal, Ivan P. Nevirkovets, Carol Crean, Andrew I. Minett, Gordon G. Wallace

Gordon Wallace

Carbon nanotubes are one of the most prominent materials in research for creating electrodes for portable electronics. When coupled with metallic nanoparticles the performance of carbon nanotube electrodes can be dramatically improved. Microwave reduction is an extremely rapid method for producing carbon nanotube-metallic nanoparticle composites, however this technique has so far been limitied to carbon nanotube soot. An understanding of the microwave process and the interactions of metallic nanoparticles with carbon nanotubes has allowed us to extend this promising functionalisation route to pre-formed CNT elelctrode architectures. Nanoparticle reduction onto pre-formed architectures reduces metallic nanoparticle waste as particles are not formed …

A Study Of The Status And Future Of Superconducting Magnetic Energy Storage In Power Systems, X Xue, Eric Cheng, Danny Sutanto

Professor Darmawan Sutanto

Superconducting magnetic energy storage (SMES) systems offering flexible, reliable, and fast acting power compensation are applicable to power systems to improve power system stabilities and to advance power qualities. The authors have summarized researches on SMES applications to power systems. Furthermore, various SMES applications to power systems have been described briefly and some crucial schematic diagrams and equations are given. In addition, this study presents valuable suggestions for future studies of SMES applications to power systems. Hence, this paper is helpful for co-researchers who want to know about the status of SMES applications to power systems.

Power System Applications Of Superconducting Magnetic Energy Storage Systems, X D. Xue, Eric Kw Cheng, Danny Sutanto

Professor Darmawan Sutanto

This study overviewed current researches on power system applications of SMES systems. Some key schematic diagrams of applications were given, too. Furthermore, the authors tried to present a few valuable suggestions for future studies of SMES applications to power systems.

Optimal Configuration Assessment Of Renewable Energy In Malaysia, Ahmed Haidar, Priscilla John, Mohd Shawal

Dr Ahmed Mohamed Ahmed Haidar

This paper proposes the use of a PVewindediesel generator hybrid system in order to determine the optimal configuration of renewable energy in Malaysia and to compare the production cost of solar and wind power with its annual yield relevant to different regions in Malaysia namely, Johor, Sarawak, Penang and Selangor. The configuration of optimal hybrid system is selected based on the best components and sizing with appropriate operating strategy to provide a cheap, efficient, reliable and cost-effective system. The various renewable energy sources and their applicability in terms of cost and performance are analyzed. Moreover, the annual yield and cost …

Smart Control Of Upcq Within Microgrid Energy System, C Benachaiba, Ahmed Haidar, O Habab, O Abdelkhalek

Dr Ahmed Mohamed Ahmed Haidar

One of the most popular issues in the future power distribution is the quality improvement of microgrid and the development of smart grid (SG). Many applications operating at the microgrid level can be considered as smart grid functions. This paper proposes the application of Fuzzy Logic (FL) technique within microgrid energy system based on the most modern power conditioning equipment devices such as Unified Power Quality Conditioner (UPQC). This technique is working together with the microgrid to track the disturbance of the smart grid and improve the quality of the system with a high flexibility. Furthermore, a control methodology developed …

An Energy-Aware Multilevel Clustering Algorithm For Wireless Sensor Networks, Xinfang Yan, Jiangtao Xi, Joe F. Chicharo, Yanguang Yu

Dr Yanguang Yu

Clustering sensors nodes as the basic of routing is an efficient mechanism for prolonging the lifetime of wireless sensor networks. In this paper, the high-efficient multilevel clustering is abstracted as a root tree which has the performances of the minimal relay set and the maximal weight according to graph theory. A mathematical model for the clustering virtual backbone is built. Based on the model, an algorithm called energy-aware multilevel clustering (EAMC) is proposed. The EAMC can reduce the number of relays used for data transmission by minimizing the amount of the nodes in the root tree (that is cluster-head). Furthermore, …

Potential Reduction In Energy Use From A High Speed Rail Network In Australia, Philip Laird

Dr Philip Laird

High Speed Rail or HSR with electric passenger trains using steel wheels on steel rails with maximum operating speeds of 250km/h or more is now operational in 12 countries. It is now under review in Australia. The paper considers energy use on the 10 top routes of the Melbourne-Sydney and Sydney-Brisbane corridors and finds that HSR was in place by 2020, HSR could reduce the use of aviation fuel by over 450 million litres each year. External costs and Sydney airport issues are also noted.

Hydrogen Energy Storage For A Permanent Magnet Wind Turbine Generator Based Autonomous Hybrid Power System, Nishad Mendis, Saad Sayeef, Kashem Muttaqi, Sarath Perera

Associate Professor Sarath Perera

The Performance of a novel hybrid Remote Area Power Supply (RAPS) system consisting of a Permanent Magnet Synchronous Generator (PMSG), fuel cell system, electrolyser and synchronous condenser is investigated in this paper. The fuel cell system is used to provide power during under-generation scenarios whereas the electrolyser absorbs excess power during over-generation conditions. A synchronous condenser is incorporated into the RAPS system to provide better reactive power and inertial support. Individual controllers for each system module have been developed and implemented. A control coordination methodology is established with a view to regulate the active and reactive power balance of the …

Control Of Energy Storage Interface With A Bidirectional Converter For Photovoltaic Systems, K.N Hasan, M.E Haque, Michael Negnevitsky, Kashem Muttaqi

Associate Professor Kashem Muttaqi

Efficient energy storage is one of the greatest concerns for renewable power generation. This paper focuses on the control of a battery management system (BMS) for photovoltaic (PV) applications with a high efficiency bidirectional converter. The proposed BMS control strategy utilizes the dc bus power and battery state of charge (SOC) for the charging and discharging of the battery with a bidirectional converter. The bidirectional converter includes fewer components and switches, has less switching losses with zero voltage switching, and has high gain buck-boost operations. A new control algorithm of charging-discharging control for the battery storage system is proposed. The …

Hydrogen Energy Storage For A Permanent Magnet Wind Turbine Generator Based Autonomous Hybrid Power System, Nishad Mendis, Saad Sayeef, Kashem Muttaqi, Sarath Perera

Associate Professor Kashem Muttaqi

The Performance of a novel hybrid Remote Area Power Supply (RAPS) system consisting of a Permanent Magnet Synchronous Generator (PMSG), fuel cell system, electrolyser and synchronous condenser is investigated in this paper. The fuel cell system is used to provide power during under-generation scenarios whereas the electrolyser absorbs excess power during over-generation conditions. A synchronous condenser is incorporated into the RAPS system to provide better reactive power and inertial support. Individual controllers for each system module have been developed and implemented. A control coordination methodology is established with a view to regulate the active and reactive power balance of the …

A Comparative Study Of Vehicle Drive Performance And Energy Efficiency, S. Abdul Rahman, P. D. Walker, Nong Zhang, Jianguo Zhu, Haiping Du

Dr Haiping Du

In this paper, two types of increasingly more efficient and greener vehicles are analyzed and compared. These vehicles are: a proposed conceptual seriesparallel powertrain, the University of Technology, Sydney plug-in hybrid electric vehicle (UTS PREY); and, a conventional series-parallel hybrid electric vehicle with an internal combustion engine .. The UTS PREY requires only a single electric machine to function as an electric motor or generator in different time intervals controlled by a special energy management strategy. The UTS PREV uses two energy storage devices, the battery and the ultracapacitor, which can work together effectively to maintain the state of charge …

A Novel Anti-Collision Protocol For Energy Efficient Identification And Monitoring In Rfid-Enhanced Wsns, Kwan-Wu Chin, Dheeraj Klair

Associate Professor Kwan-Wu Chin

This paper presents a dynamic framed slotted Aloha (DFSA) protocol that is energy efficient, and more importantly, is the first protocol capable of monitoring tags. Our protocol uses three separate frames: 1) reservation, 2) body, and 3) monitor. The reservation and body frame are used to identify tags, whereas the monitor frame is used to keep track of identified tags. We have performed extensive simulation studies on all three frames, and compared our protocol with existing framed Aloha protocols. From our results, we confirm that our protocol is suitable for use in RFID-enhanced Wireless Sensor Networks (WSNs).

A Simulation Study On The Energy Efficiency Of Pure And Slotted Aloha Based Rfid Tag Reading Protocols, Alejandro Ruiz-Rivera, Dheeraj Klair, Kwan-Wu Chin

Associate Professor Kwan-Wu Chin

This paper studies the energy efficiency of twelve Pure and Slotted Aloha tag reading protocol variants via simulation. We compare their energy consumption in three collision resolution phases: 1) success, 2) collision, and 3) idle. Our extensive simulation results show that Pure Aloha with fast mode and muting has the lowest energy consumption, and hence is most suited for deployment in energy-constrained environments.

An Energy-Aware Multilevel Clustering Algorithm For Wireless Sensor Networks, Xinfang Yan, Jiangtao Xi, Joe F. Chicharo, Yanguang Yu

Professor Joe F. Chicharo

Clustering sensors nodes as the basic of routing is an efficient mechanism for prolonging the lifetime of wireless sensor networks. In this paper, the high-efficient multilevel clustering is abstracted as a root tree which has the performances of the minimal relay set and the maximal weight according to graph theory. A mathematical model for the clustering virtual backbone is built. Based on the model, an algorithm called energy-aware multilevel clustering (EAMC) is proposed. The EAMC can reduce the number of relays used for data transmission by minimizing the amount of the nodes in the root tree (that is cluster-head). Furthermore, …

Design Of A High Temperature Superconductor Magnetic Energy Storage Systems, R L Causley, Christopher Cook, Steve Gower

Christopher Cook

The University of Wollongong (UoW) has received funding for the research and development of a 20 kJ high temperature superconducting magnetic energy storage device (HTS SMES). This SMES will be operated at 25 K in contrast to most existing HTS designs, which operate at 77K. This paper includes a literature review of the current technology for the configuration of the SMES coil and a summary of the work done at UoW to date. Solenoidal and toroidal coils designs are compared to determine which will provide the required level of energy stored for a minimum superconductor and device volume. The design …

Chemically Activated Reactions On The C7h5 Energy Surface: Propargyl + Diacetylene, I-C5h3 + Acetylene, And N-C5h3 + Acetylene, Gabriel Da Silva, Adam J. Trevitt

Adam Trevitt

This study uses computational chemistry and statistical reaction rate theory to investigate the chemically activated reaction of diacetylene (butadiyne, C4H2) with the propargyl radical (C •H2CCH) and the reaction of acetylene (C 2H2) with the i-C5H3 (CH 2CCCC•H) and n-C5H3 (CHCC •HCCH) radicals. A detailed G3SX-level C7H 5 energy surface demonstrates that the C3H3 + C4H2 and C5H3 + C2H 2 addition reactions proceed with moderate barriers, on the order of 10 to 15 kcal mol-1, and form activated open-chain C 7H5 species that can isomerize to the fulvenallenyl radical with the highest barrier still significantly below the entrance channel …

Developing The Next Generation Of Women And Minority Scientists For The Nuclear Energy Industry, Darrell Burrell, Andrea Todd, Aikyna Finch, Maurice Dawson

Maurice Dawson

The largest source of carbon dioxide emissions globally is the combustion of fossil fuels (coal, oil and natural gas) in power plants, automobiles, industrial facilities and other sources. Generating electricity is the single largest source of carbon dioxide emissions, representing 41% of all emissions. Since 2007 the United States has been more actively considering nuclear power as an option for developing energy. Three decades after the Three Mile Island accident seemed to doom the nuclear power industry, the idea of a nuclear renaissance has been gaining public acceptance as a way to generate energy without greenhouse gas emissions and meet …