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Full-Text Articles in Social and Behavioral Sciences
Reliability Analysis Of Strain-Softening Slopes, Robin N. Chowdhury, Gautam Bhattacharya
Reliability Analysis Of Strain-Softening Slopes, Robin N. Chowdhury, Gautam Bhattacharya
Faculty of Engineering and Information Sciences - Papers: Part A
Slope reliability must be considered in the context of a variety of factors which control or influence stability or the balance between disturbing and resisting forces. The problems of slope stability are varied, ranging from fi rst-time failures to reactivated landslides and from minor, localized slope movements to catastrophic events. Reliability analysis within a probabilistic framework offers a very powerful tool for taking into consideration the variability of key geotechnical parameters as well as other uncertainties. In this paper, the progressive decrease in shear strength along potential slip surfaces is considered in terms of a residual factor treated as one …
A Comparison Study Of The Numerical Integration Methods In The Trajectory Tracking Application Of Redundant Robot Manipulators, Emre Sariyildiz, Hakan Temeltas
A Comparison Study Of The Numerical Integration Methods In The Trajectory Tracking Application Of Redundant Robot Manipulators, Emre Sariyildiz, Hakan Temeltas
Faculty of Engineering and Information Sciences - Papers: Part A
Differential kinematic has a wide range application area in robot kinematics. The main advantage of the differential kinematic is that it can be easily implemented any kind of mechanisms. In differential kinematic method, Jacobian is used as a mapping operator in the velocity space. The joint velocities are required to be integrated to obtain the pose of the robot manipulator. This integration can be evaluated by using numerical integration methods, since the inverse kinematic equations are highly complex and nonlinear. Thus, the performances of the numerical integration methods affect the trajectory tracking application. This paper compares the performances of numerical …
Use Centric Hci Requirements Elicitation, Robert B. K Brown
Use Centric Hci Requirements Elicitation, Robert B. K Brown
Faculty of Engineering and Information Sciences - Papers: Part A
Among persistent issues in HCI are its separation from the other disciplines involved in the construction of Information Systems, any coherently extensive methodology and straight forward techniques for clustering interface elements for best effect. An approach to HCI which encompasses the full context of use (rather than just of usage) and entails more traditional SA&D within a single framework could be of some value. This paper introduces the HCI values of the Activity Theoretic System Architecture (ATSA) Method. © 2011 Robert B.K. Brown.
An Analytical Simulation Technique For Cone-Beam Ct And Pinhole Spect, Xuezhu Zhang, Yujin Qi
An Analytical Simulation Technique For Cone-Beam Ct And Pinhole Spect, Xuezhu Zhang, Yujin Qi
Faculty of Engineering and Information Sciences - Papers: Part A
This study was aimed at developing an eficient simulation technique with an ordinary PC．The work involved derivation of mathematical operators，analytic phantom generations，and effective analytical projectors developing for cone—beam CT and pinhole SPECT imaging．The computer simulations based on the analytical projectors were developed by ray—tracing method for cone—beam CT and voxel—driven method for pinhole SPECT of degrading blurring．The 3D Shepp Logan，Jaszczak and Defrise phantoms were used for simulation evaluations and image reconstructions．The reconstructed phantom images were of good accuracy with the phantoms．The results showed that the analytical simulation technique is an efi cient tool for studying cone—beam CT and pinhole SPECT …
Bauschinger Effect In Microalloyed Steels: Part Ii. Influence Of Work Softening On Strength Development During Uoe Line-Pipe Forming, Andrii Kostryzhev, Martin Strangwood, Claire L. Davis
Bauschinger Effect In Microalloyed Steels: Part Ii. Influence Of Work Softening On Strength Development During Uoe Line-Pipe Forming, Andrii Kostryzhev, Martin Strangwood, Claire L. Davis
Faculty of Engineering and Information Sciences - Papers: Part A
The Bauschinger effect (a reduced yield stress at the start of reverse deformation following forward prestrain) is an important factor of strength development for cold metal forming technology. In steels, the magnitude of the Bauschinger effect depends on composition, through the presence of microalloy precipitates, and prior processing, through the size and distribution of the microalloy precipitates and the presence of retained work hardening. In this article, the parameters of the Bauschinger effect and work hardening (coefficient and exponent) in forward and reverse deformations were quantitatively related to the particle number density and dislocation density for two high-strength low-alloy (HSLA) …
Enhanced Gas Drainage From Undersaturated Coal Bed Methane Reservoirs, Dennis John Black, Naj Aziz, Ting Ren
Enhanced Gas Drainage From Undersaturated Coal Bed Methane Reservoirs, Dennis John Black, Naj Aziz, Ting Ren
Faculty of Engineering and Information Sciences - Papers: Part A
Traditional methods of coal seam gas drainage rely on the use of reservoir pressure reduction to promote gas desorption from the coal matrix. Studies in coal mining gas drainage operations, particularly in coal seams that are deeply undersaturated and have low permeability, found the rate of reservoir pressure reduction was prohibitively slow. In such conditions, lengthy production delays have been experienced while additional gas drainage drilling is undertaken in an attempt to reduce seam gas content below specified threshold limits. Such drilling represents a high additional operating cost and yields low total gas production whilst adversely impacting the mine's gas …
Methods For Generating Complex Networks With Selected Structural Properties For Simulations: A Review And Tutorial For Neuroscientists, Brenton Prettejohn, Matthew Berryman, Mark Mcdonnell
Methods For Generating Complex Networks With Selected Structural Properties For Simulations: A Review And Tutorial For Neuroscientists, Brenton Prettejohn, Matthew Berryman, Mark Mcdonnell
Faculty of Engineering and Information Sciences - Papers: Part A
Many simulations of networks in computational neuroscience assume completely homogenous random networks of the Erdös–Rényi type, or regular networks, despite it being recognized for some time that anatomical brain networks are more complex in their connectivity and can, for example, exhibit the “scale-free” and “small-world” properties. We review the most well known algorithms for constructing networks with given non-homogeneous statistical properties and provide simple pseudo-code for reproducing such networks in software simulations. We also review some useful mathematical results and approximations associated with the statistics that describe these network models, including degree distribution, average path length, and clustering coefficient. We …
Solidification And The Δ/Γ Phase Transformation Of Steels In Relation To Casting Defects, Suk Chun Moon, Rian Dippenaar, Sang-Hyeon Lee
Solidification And The Δ/Γ Phase Transformation Of Steels In Relation To Casting Defects, Suk Chun Moon, Rian Dippenaar, Sang-Hyeon Lee
Faculty of Engineering and Information Sciences - Papers: Part A
Many advanced steels fall within the peritectic composition range, which are notoriously difficult to cast due to cracking and breakout problems in the continuous casting process especially at high casting speeds. In this study an attempt was made to obtain practical understanding of the solidification and the δ→γ phase transformation of various commercial steels using high-temperature laser-scanning confocal microscopy. Under rapid cooling conditions the transformation morphology showed a massive-type of transition rather than a classical diffusion-controlled transformation.
Effects Of A Brief Cognitive Intervention Aimed At Communicating The Negative Reinforcement Explanation For Smoking On Relevant Cognitions And Urges To Smoke, Mairtin S. Mcdermott, Theresa M. Marteau, Peter Hajek
Effects Of A Brief Cognitive Intervention Aimed At Communicating The Negative Reinforcement Explanation For Smoking On Relevant Cognitions And Urges To Smoke, Mairtin S. Mcdermott, Theresa M. Marteau, Peter Hajek
Faculty of Engineering and Information Sciences - Papers: Part A
Introduction:The aim of the current study was to assess the impact of an intervention aimed at communicating the negative reinforcement explanation for smoking, a set of ideas derived from popular self-help books, upon participants' cognitions and urges to smoke. Methods: Smokers (n = 205) undergoing standard stop-smoking treatment were randomised to receive either the experimental intervention, a brief intervention aimed at communicating the explanation or a control intervention, a video on the health risks of smoking. Outcomes were participants' acceptance of the negative reinforcement explanation for smoking, positive outcome expectations for smoking, self-efficacy and urges to smoke reported at one …
Self-Shape Optimisation Of Cold-Formed Steel Closed Profiles Using Genetic Algorithms, Benoit Gilbert, Lip H. Teh, Hong Guan
Self-Shape Optimisation Of Cold-Formed Steel Closed Profiles Using Genetic Algorithms, Benoit Gilbert, Lip H. Teh, Hong Guan
Faculty of Engineering and Information Sciences - Papers: Part A
For economical benefits, optimisation of mass-produced structural steel products is widely researched. The objective is to minimise the quantity of material used without sacrificing the strength and practicality of the structural members. Current research focuses on optimising the dimensions of conventional cross-sectional shapes but rarely considers discovering new optimum shapes. This report introduces the concepts of a new optimisation method which enables the crosssection to self-shape to an optimum by using the evolution and adaptation benefits of Genetic Algorithm. The feasibility and accuracy of the method are verified by implementing it to find optimum thin-walled profiles against simple parameters for …
An Early Asearc - Taught Subject: Has It Been A Success?, Carole Birrell, Ken Russell
An Early Asearc - Taught Subject: Has It Been A Success?, Carole Birrell, Ken Russell
Faculty of Engineering and Information Sciences - Papers: Part A
A 300-level subject covering Sample Surveys and Experimental Design has now been taught jointly to the Universities of Wollongong and Newcastle for two years, first using video-conferencing and then the Access Grid. In both years the subject was delivered by the same two lectures. We provide an initial review of the subject. We discuss its organisation, the use of technology, changes in our teaching and administrative styles needed to cope with this mode of delivery, feedback from students and our reaction to all of these. An overview of the subject results is given.
Australia Should Delay A Carbon Tax Until The Rest Of The World Acts, Henry Ergas
Australia Should Delay A Carbon Tax Until The Rest Of The World Acts, Henry Ergas
Faculty of Engineering and Information Sciences - Papers: Part A
The big question about the carbon tax is not whether it's a good or a bad idea in theory. The major issue is whether it makes sense for Australia to implement it at a time of great uncertainty, both in terms of economic outlook and the extent and nature of international action. To my mind a carbon tax is not desirable. Australia's prosperity is based on a resource endowment that is carbon intensive, both in terms of our mineral and our agricultural sector. Moreover, much of that carbon intensity is not amenable to technological quick-fixes. For instance, there is little …
Can Australia High Speed Rail Overcome It's Bumpy History?, Philip Laird
Can Australia High Speed Rail Overcome It's Bumpy History?, Philip Laird
Faculty of Engineering and Information Sciences - Papers: Part A
The Australian Government has released an "implementation" study for high speed rail (or HSR) on the east coast with a further study to follow. The proposal looks at corridors between Melbourne, Sydney and Brisbane. It includes the option of three-hour travel times between Sydney and Melbourne, with tickets costing around $100. With the projected price of the project starting at around $60 billion, and Australia's chequered history with HSR, it is not unreasonable to ask whether the project will commence. In this case, would Sydney to Newcastle take preference over Sydney to Melbourne?
Cracking Bin Laden's Computer Code: Unlikely, Jennifer Seberry
Cracking Bin Laden's Computer Code: Unlikely, Jennifer Seberry
Faculty of Engineering and Information Sciences - Papers: Part A
It has been reported that Osama bin Laden's hard drives have been seized, hard drives that could conceivably contain information regarding the membership, funding and future plans of al-Qaeda. Information of this type would help anti-terrorism agencies enormously. The hard drives were recovered from bin Laden's compound in the Pakistani city of Abbottabad and are said to be encrypted with a encryption method known as AES-256. AES-256 is the current world standard for data encryption and is used by the likes of Wikileaks and the US Government to encrypt sensitive information.
Adjusting For Network Size And Composition Effects In Exponential Family Random Graph Models, Pavel N. Krivitsky, M Handcock, Martina Morris
Adjusting For Network Size And Composition Effects In Exponential Family Random Graph Models, Pavel N. Krivitsky, M Handcock, Martina Morris
Faculty of Engineering and Information Sciences - Papers: Part A
Exponential-family random graph models (ERGMs) provide a principled way to model and simulate features common in human social networks, such as propensities for homophily and friend-ofa- friend triad closure. We show that, without adjustment, ERGMs preserve density as network size increases. Density invariance is often not appropriate for social networks. We suggest a simple modification based on an offset which instead preserves the mean degree and accommodates changes in network composition asymptotically. We demonstrate that this approach allows ERGMs to be applied to the important situation of egocentrically sampled data. We analyze data from the National Health and Social Life …
Three-Dimensional Nonlinear Analysis Of Seismic Ground Response Of Soft Soils In Shanghai, Qingsheng Chen, Guangyun Gao, Junfeng He
Three-Dimensional Nonlinear Analysis Of Seismic Ground Response Of Soft Soils In Shanghai, Qingsheng Chen, Guangyun Gao, Junfeng He
Faculty of Engineering and Information Sciences - Papers: Part A
Reduced order bounding surface model was employed to study 3-D seismic ground response of site considering the nonlinearity of soft soils in Shanghai. A nonlinear procedure for response analysis of horizontal layered sites subjected to multidirectional earthquake loading was used to study vertical and horizontal ground responses, respectively, under unidirectional and multidirectional base excitations (Taft). Also, the development of ratio of vertical and horizontal peak acceleration and the effects of the variation of groundwater table on the characteristics of seismic responses were studied. The study results show that the characteristics of vertical seismic ground response are much different from those …
Feasibility Study Of Microgrid Application In Langkawi And Socotra Islands, Ahmed Haidar
Feasibility Study Of Microgrid Application In Langkawi And Socotra Islands, Ahmed Haidar
Faculty of Engineering and Information Sciences - Papers: Part A
Alternative Energy is becoming a popular and an essential energy resource in the current century. This paper investigates the effect of using a hybrid microgrid system in Langkawi and Socotra Islands. Configuration of the optimal hybrid system is selected based on the best components and its sizing with appropriate operation strategy to provide a cheap efficient, reliable and cost effective system. The total net present cost for the two Islands has been determined using HOMER program based on the Island’s data. This finding will help to install sources of renewable energy in places that will ensure low cost and performance …
On-Chip Stimulated Brillouin Scattering, Ravi Pant, Christopher Poulton, Duk-Yong Choi, Hannah Mcfarlane, Samuel Hile, Enbang Li, Luc Thevenaz, Barry Luther-Davies, Stephen J. Madden, Benjamin J. Eggleton
On-Chip Stimulated Brillouin Scattering, Ravi Pant, Christopher Poulton, Duk-Yong Choi, Hannah Mcfarlane, Samuel Hile, Enbang Li, Luc Thevenaz, Barry Luther-Davies, Stephen J. Madden, Benjamin J. Eggleton
Faculty of Engineering and Information Sciences - Papers: Part A
We demonstrate on-chip stimulated Brillouin scattering (SBS) in an As2S3 chalcogenide rib waveguide. SBS was characterized in a 7cm long waveguide with a cross-section 4μm x 850nm using the backscattered signal and pump-probe technique. The measured Brillouin shift and its full-width at half-maximum (FWHM) linewidth were ~7.7 GHz and 34 MHz, respectively. Probe vs. pump power measurements at the Brillouin shift were used to obtain the gain coefficient from an exponential fit. The Brillouin gain coefficient obtained was 0.715 x 10−9 m/W. A probe gain of 16 dB was obtained for a CW pump power of ~300 mW.
Cavity Enhanced Stimulated Brillouin Scattering In An Optical Ship For Multiorder Stokes Generation, Ravi Pant, Enbang Li, Duk-Yong Choi, Christopher Poulton, Stephen J. Madden, Barry Luther-Davies, Benjamin J. Eggleton
Cavity Enhanced Stimulated Brillouin Scattering In An Optical Ship For Multiorder Stokes Generation, Ravi Pant, Enbang Li, Duk-Yong Choi, Christopher Poulton, Stephen J. Madden, Barry Luther-Davies, Benjamin J. Eggleton
Faculty of Engineering and Information Sciences - Papers: Part A
We report the first demonstration of on-chip cascaded stimulated Brillouin scattering (SBS). Cascaded SBS is characterized in a 4 cm long chalcogenide ( As2S3 ) rib waveguide where the end facet reflections provide a monolithic Fabry–Perot (FP) resonator. The presence of the FP cavity reduces the Brillouin gain threshold, which enables observation of cascaded SBS at reduced pump powers. We observe up to three orders of Stokes waves in the backscattered signal at a coupled peak power of 1.34 W . Anti-Stokes waves due to four-wave mixing between the pump and the Stokes wave were observed in the forward spectrum.
Terahertz-Wave Parametic Oscillator With Misalignment-Resistant Tuning Cavity, Bo Sun, Sanxing Li, Jinsong Liu, Enbang Li, Jianquan Yao
Terahertz-Wave Parametic Oscillator With Misalignment-Resistant Tuning Cavity, Bo Sun, Sanxing Li, Jinsong Liu, Enbang Li, Jianquan Yao
Faculty of Engineering and Information Sciences - Papers: Part A
We demonstrate a terahertz-wave parametric oscillator (TPO) with a corner-cube resonator consisting of a corner-cube prism (CCP) and a flat mirror. By using the cavity configuration proposed in this Letter, the generation of tunable monochromatic terahertz (THz) waves can be achieved just by rotating the flat mirror instead of rotating the TPO cavity relative to the pump beam. The THz-wave output intensity and pulse width can be controlled periodically by rotating the CCP around the cavity axis. The TPO stability against cavity misalignment is significantly improved by at least 1 to 2 orders of magnitude compared with the conventional plane–parallel …
Octave Spanning Supercontinuum In An As2s3 Taper Using Ultralow Pump Pulse Energy, Darren D. Hudson, Stephen A. Dekker, Eric C. Magi, Alexander C. Judge, Stuart D. Jackson, Enbang Li, J S. Sanghera, L B. Shaw, I D. Aggarwal, Benjamin J. Eggleton
Octave Spanning Supercontinuum In An As2s3 Taper Using Ultralow Pump Pulse Energy, Darren D. Hudson, Stephen A. Dekker, Eric C. Magi, Alexander C. Judge, Stuart D. Jackson, Enbang Li, J S. Sanghera, L B. Shaw, I D. Aggarwal, Benjamin J. Eggleton
Faculty of Engineering and Information Sciences - Papers: Part A
An octave spanning spectrum is generated in an As2S3 taper via 77 pJ pulses from an ultrafast fiber laser. Using a previously developed tapering method, we construct a 1.3 μm taper that has a zero-dispersion wavelength around 1.4 μm . The low two-photon absorption of sulfide-based chalcogenide fiber allows for higher input powers than previous efforts in selenium-based chalcogenide tapered fibers. This higher power handling capability combined with input pulse chirp compensation allows an octave spanning spectrum to be generated directly from the taper using the unamplified laser output.
Geotechnical Properties Of Reconstituted Dredged Mud, Dhanya Ganesalingam, Arul Arulrajah, Jayantha Ameratunga, Peter Boyle, Nagaratnam Sivakugan
Geotechnical Properties Of Reconstituted Dredged Mud, Dhanya Ganesalingam, Arul Arulrajah, Jayantha Ameratunga, Peter Boyle, Nagaratnam Sivakugan
Faculty of Engineering and Information Sciences - Papers: Part A
In the present study, laboratory tests were undertaken in order to assess the index properties and consolidation characteristics of dredged mud which is excavated during the maintenance dredging works carried out in Port of Brisbane, Queensland, Australia. These dredged spoils are reused as the fill materials in the major land reclamation project currently undertaken adjacent to the port for expanding the port facitlites. In the laboratory, index properties of dredged mud such as, particle size distuibution, Atterberg limits and specifc gravity were determined. Oedometer tests were conducted to calculate the consolidation properties of dredged mud. Laboratory resuls for consolidation properties …
Authenticated Key Exchange Under Bad Randomness, Guomin Yang, Shanshan Duan, Duncan Wong, Chik How Tan, Huaxiong Wang
Authenticated Key Exchange Under Bad Randomness, Guomin Yang, Shanshan Duan, Duncan Wong, Chik How Tan, Huaxiong Wang
Faculty of Engineering and Information Sciences - Papers: Part A
We initiate the formal study on authenticated key exchange (AKE) under bad randomness. This could happen when (1) an adversary compromises the randomness source and hence directly controls the randomness of each AKE session; and (2) the randomness repeats in different AKE sessions due to reset attacks.We construct two formal security models, Reset-1 and Reset-2, to capture these two bad randomness situations respectively, and investigate the security of some widely used AKE protocols in these models by showing that they become insecure when the adversary is able to manipulate the randomness. On the positive side, we propose simple but generic …
Effect Of Magnetostatic Field On Microstructure Of 5005 Aluminum Alloy Sheet By Roll-Casting, Jintao Li, Guangming Xu, Jianzhong Cui
Effect Of Magnetostatic Field On Microstructure Of 5005 Aluminum Alloy Sheet By Roll-Casting, Jintao Li, Guangming Xu, Jianzhong Cui
Faculty of Engineering and Information Sciences - Papers: Part A
The roll-casting technology of 5000 series aluminum alloy is one of the difficulties at present. Roll-casting technology was employed in this paper and high quality 5005 aluminum alloy sheets were fabricated successfully under different conditions. The solidification of melt in roll-casting process is the rapid directional solidification. The effect of magnetostatic field on microstructure of 5005 aluminum alloy sheet by roll-casting has been investigated and analyzed. The results indicate that imposing magnetostatic field can refine the grains of 5005 aluminum alloy.
Sensitization Behaviour Of 11-12% Cr Aisi 409 Stainless Steel During Low Heat Input Welding, Cornelis Janise Van Niekerk, Madeleine Du Toit
Sensitization Behaviour Of 11-12% Cr Aisi 409 Stainless Steel During Low Heat Input Welding, Cornelis Janise Van Niekerk, Madeleine Du Toit
Faculty of Engineering and Information Sciences - Papers: Part A
The study comprised of the investigation into the sensitization characteristics of AISI 409 titanium stabilized ferritic stainless steel during low heat input welding. AISI 409 is a fully ferritic stainless steel used in catalytic converters and tubing for automotive exhaust systems due to the supposition that sensitization does not occur during low heat input welding. Two plates of 2 and 4 mm were tested for sensitization during low heat input welding. The study confirmed that chromium carbide (M23C6) precipitation occurs on the grain boundaries in the heat-affected zone with consequent depletion of Cr adjacent to the …
Large Area Microfabrication Of Electroactive Polymeric Structures Based On Near-Field Electrospinning, R Lameiro, Vitor Sencadas, Senentxu Lanceros-Méndez, J H. Correia, P M. Mendes
Large Area Microfabrication Of Electroactive Polymeric Structures Based On Near-Field Electrospinning, R Lameiro, Vitor Sencadas, Senentxu Lanceros-Méndez, J H. Correia, P M. Mendes
Faculty of Engineering and Information Sciences - Papers: Part A
The use of electroactive polymeric materials for sensing and actuating applications is very attractive due to important properties like low operating voltage, low form factor, or high mechanical flexibility. However, its use has been conditioned by the lack of available processing methods for such materials. The deposition of thin layers is very easy by conventional techniques; however obtaining patterned layers is not a trivial task. This paper presents a methodology suitable to fabricate electroactive polymeric microstructures on large area devices. Structures ranging from ∼1, 5 mm to ∼100 μm width, with a thickness of ∼12 μm, were obtained.
Tailoring The Morphology And Crystallinity Of Poly(L-Lactide Acid) Electrospun Membranes, Clarisse Ribeiro, Vitor Sencadas, Carlos M. Costa, J L. Gomez Ribelles, Senentxu Lanceros-Méndez
Tailoring The Morphology And Crystallinity Of Poly(L-Lactide Acid) Electrospun Membranes, Clarisse Ribeiro, Vitor Sencadas, Carlos M. Costa, J L. Gomez Ribelles, Senentxu Lanceros-Méndez
Faculty of Engineering and Information Sciences - Papers: Part A
Biodegradable poly(L-lactic acid) (PLLA) microfibers were prepared by electrospinning by varying the applied potential, solution flow rate and collector conditions. PLLA fibers with smoothly oriented and random morphologies were obtained and characterized by scanning electron microscopy. The optimum fiber orientation was obtained at 1000 rpm using a 20.3 cm diameter collecting drum, while for higher and lower drum rotation speeds, the rapid random motion of the jets resulted in a random fiber distribution. The deformation of the jet with rapid solidification during electrospinning often results in a metastable phase. PLLA electrospun fibers are amorphous but contain numerous crystal nuclei that …
Effect Of The Carbon Nanotube Surface Characteristics On The Conductivity And Dielectric Constant Of Carbon Nanotube/Poly(Vinylidene Fluoride) Composites, S A. Carabineiro, Manuel F. Pereira, J Nunes-Pereira, Cristina Caparrós, Vitor Sencadas, Senentxu Lanceros-Méndez
Effect Of The Carbon Nanotube Surface Characteristics On The Conductivity And Dielectric Constant Of Carbon Nanotube/Poly(Vinylidene Fluoride) Composites, S A. Carabineiro, Manuel F. Pereira, J Nunes-Pereira, Cristina Caparrós, Vitor Sencadas, Senentxu Lanceros-Méndez
Faculty of Engineering and Information Sciences - Papers: Part A
Commercial multi-walled carbon nanotubes (CNT) were functionalized by oxidation with HNO3, to introduce oxygen-containing surface groups, and by thermal treatments at different temperatures for their selective removal. The obtained samples were characterized by adsorption of N2 at -196°C, temperature-programmed desorption and determination of pH at the point of zero charge. CNT/poly(vinylidene fluoride) composites were prepared using the above CNT samples, with different filler fractions up to 1 wt%. It was found that oxidation reduced composite conductivity for a given concentration, shifted the percolation threshold to higher concentrations, and had no significant effect in the dielectric response.
Thermal, Dielectrical And Mechanical Response Of A And B-Poly(Vinilydene Fluoride)/Co-Mgo Nanocomposites, A J. Paleo, Carlos Martínez-Boubeta, Lluis Balcells, Carlos M. Costa, Vitor Sencadas, Senentxu Lanceros-Méndez
Thermal, Dielectrical And Mechanical Response Of A And B-Poly(Vinilydene Fluoride)/Co-Mgo Nanocomposites, A J. Paleo, Carlos Martínez-Boubeta, Lluis Balcells, Carlos M. Costa, Vitor Sencadas, Senentxu Lanceros-Méndez
Faculty of Engineering and Information Sciences - Papers: Part A
Nanocomposites of the self-forming core-shell Co-MgO nanoparticles, which were of approximately 100 nm in diameter, and poly(vinylidene fluoride) (PVDF) polymer have been prepared. When the polymer is crystallized in the a-phase, the introduction of the nanoparticles leads to nucleation of the g-phase of PVDF, increasing also the melting temperature of the polymer. With the introduction of the Co-MgO particles, the dielectric constant of the material slightly increases and the storage modulus decreases with respect to the values obtained for the pure polymer.
Network Neighbor Effects On Customer Churn In Cell Phone Networks, Pavel N. Krivitsky, Pedro Ferreira, Rahul Telang
Network Neighbor Effects On Customer Churn In Cell Phone Networks, Pavel N. Krivitsky, Pedro Ferreira, Rahul Telang
Faculty of Engineering and Information Sciences - Papers: Part A
No abstract provided.