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Full-Text Articles in Physics

A Long-Channel Model For The Asymmetric Double-Gate Mosfet Valid In All Regions Of Operation, Abhishek Kammula, Bradley Minch Jul 2012

A Long-Channel Model For The Asymmetric Double-Gate Mosfet Valid In All Regions Of Operation, Abhishek Kammula, Bradley Minch

Bradley Minch

We present a physically based, continuous analytical model for long-channel double-gate MOSFETs. The model is particularly well suited for implementation in circuit simulators due to the simple expressions for the current andthe continuous nature of the derivatives of the current which improves convergence behavior.


A Reduced Model Of Cavitation Physics For Use In Sonochemistry, Brian Storey, Andrew Szeri Jul 2012

A Reduced Model Of Cavitation Physics For Use In Sonochemistry, Brian Storey, Andrew Szeri

Brian Storey

Sonochemistry involves focusing acoustic energy through cavitation bubbles to increase chemical activity. The violent bubble collapses lead to temperatures of several thousand kelvin, which drive chemical reactions. In previous work, we gave a detailed computational model of a single bubble collapse, taking into account phase change, mass diffusion, heat diffusion and chemical reactions. All of these phenomena are important in determining the conditions at collapse. The present work involves development of a much simpler model that includes all the physics relevant to the determination of the reaction products. Comparisons with the more detailed computations are made; the reduced model is …


Water Vapour, Sonoluminescence And Sonochemistry, Brian Storey, Andrew Szeri Jul 2012

Water Vapour, Sonoluminescence And Sonochemistry, Brian Storey, Andrew Szeri

Brian Storey

Sonoluminescence is the production of light from acoustically forced bubbles; sonochemistry is a related chemical processing technique. The two phenomena share a sensitive dependence on the liquid phase. The present work is an investigation of the fate and consequences of water vapour in the interior of strongly forced argon micro–bubbles. Due to the extreme nonlinearity of the volume oscillations, excess water vapour is trapped in the bubble during a rapid inertial collapse. Water vapour is prevented from exiting by relatively slow diffusion and non–equilibrium condensation at the bubble wall. By reducing the compression heating of the mixture and through primarily …


Ftir Studies Of Pema/Pvdf-Hfp Blend Polymer Electrolyte System Incorporated With Licf3so3 Salt, Siti Rohana Majid, Sim L. N., Arof A. K. Dec 2011

Ftir Studies Of Pema/Pvdf-Hfp Blend Polymer Electrolyte System Incorporated With Licf3so3 Salt, Siti Rohana Majid, Sim L. N., Arof A. K.

Siti Rohana Majid

Poly(ethyl methacrylate), PEMA and poly(vinylidenefluoride-co-hexafluoropropylene). PVdF-HFP have been chosen as hosts for the development of a polymer blend electrolyte system. Lithium trifluoromethanesulfonate (triflate), LiCF3SO3 is the lithium ion, Li+ provider. The ratio of PEMA:PVdF-HFP in the blend is fixed at 70:30 in order to obtain transparent films with good mechanical stability. The polymers and LiCF3SO3 salt have been refluxed for 2 h at temperatures between 55 and 65 degrees C. The concentration of LiCF3SO3 salt has been varied from 0 to 40 wt.%. Fourier transform infrared (FTIR) spectroscopy has shown that blending between PEMA and PVdF-HFP has occurred from the …


Pmma-Libob Gel Electrolyte For Application In Lithium Ion Batteries, Siti Rohana Majid, Kufian M. Z., Aziz M. F., Shukur M. F., Rahim A. S., Ariffin N. E., Shuhaimi N. E. A., Yahya R., Arof A. K. Dec 2011

Pmma-Libob Gel Electrolyte For Application In Lithium Ion Batteries, Siti Rohana Majid, Kufian M. Z., Aziz M. F., Shukur M. F., Rahim A. S., Ariffin N. E., Shuhaimi N. E. A., Yahya R., Arof A. K.

Siti Rohana Majid

Different amounts of lithium bis(oxalato) borate (LiBOB) have been added into a mixture of equal weights of ethylene carbonate (EC) and propylene carbonate (PC). The variation of molar conductivity of the LiBOB based liquid electrolyte with square root of salt concentration obeys the weak electrolyte theory. The 0.6 M LiBOB in EC/PC liquid electrolyte with highest room temperature conductivity of 4.8 mS cm(-1) was chosen for further work. 10 to 50 wt.% PMMA was added to this composition and heated between 343 and 353 K for 20 min to obtain the gel polymer electrolytes (GPEs). Due to its dry state …


Graphene Oxide And Its Electrochemical Performance, Siti Rohana Majid, Ban F. Y., Huang N. M., Lim H. N. Dec 2011

Graphene Oxide And Its Electrochemical Performance, Siti Rohana Majid, Ban F. Y., Huang N. M., Lim H. N.

Siti Rohana Majid

In this study, graphene oxide (GO) was synthesized from graphite flakes using simplified Hummer's method. Field Emission Scanning Electron Microscopy (FESEM) image showed that the GO nanosheets had an average area 7000 mu m(2) with lateral dimension of up to 150 mu m. The X-Ray Diffraction (XRD) pattern revealed a (002) diffraction peak, signifying the successful synthesis of GO. GO solution was cast on an aluminum (Al) foil placed in a petri dish and left to dry to form an electrode made up of GO film on the Al foil (GO-Al). It was found that GO-Al exhibited equivalent series resistance …


Nonlinear Waves And Solitons On Contours And Closed Surfaces, Andrei Ludu Dec 2011

Nonlinear Waves And Solitons On Contours And Closed Surfaces, Andrei Ludu

Andrei Ludu

No abstract provided.


Hydrogen Production From Biogas By Oxy-Reforming: Reaction System Analysis, Aleksandra Terlecka, Wojciech M. Budzianowski Dec 2011

Hydrogen Production From Biogas By Oxy-Reforming: Reaction System Analysis, Aleksandra Terlecka, Wojciech M. Budzianowski

Wojciech Budzianowski

Oxy-reforming is emerging as an interesting alternative to conventional methods of hydrogen generation. The current article characterises this process through analysis of individual reactions: SMR (steam methane reforming), WGS (water gas shift) and CPO (catalytic partial oxidation). Analyses relate to optimisation of thermal conditions thus enabling cost-effectivenes of the process.