Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Publication
- File Type
Articles 1 - 13 of 13
Full-Text Articles in Physical Sciences and Mathematics
Modelling Carbon Nanostructures For Filtering And Adsorbing Polycyclic Aromatic Hydrocarbons, Thien Tran-Duc, Ngamta Thamwattana
Modelling Carbon Nanostructures For Filtering And Adsorbing Polycyclic Aromatic Hydrocarbons, Thien Tran-Duc, Ngamta Thamwattana
Dr Ngamta Thamwattana
The discovery of carbon nanostructures, such as graphene and carbon nanotubes, has led to the creation of many novel nano-devices. In this paper, we consider an environmental application of carbon nanostructures for filtering and adsorbing polycyclic aromatic hydrocarbons (PAHs) which are environmental pollutants. We mathematically investigate the adsorption of PAHs onto a graphene sheet and determine the underlying mechanisms of suction of PAHs into a carbon nanotube. We adopt a continuum approach together with the semi-empirical Lennard-Jones potential to determine van der Waals interaction forces and energies. Results obtained here for certain PAHs are well in agreement with existing experimental …
Continuum Modelling For Carbon And Boron Nitride Nanostructures, James M. Hill, Ngamta Thamwattana
Continuum Modelling For Carbon And Boron Nitride Nanostructures, James M. Hill, Ngamta Thamwattana
Dr Ngamta Thamwattana
Continmuum based models are presented here for certain boron nitride and carbon nanostructures.
Mechanics Of Fullerene-Carbon Nanotube Bundle Oscillators, James Hill, Ngamta Thamwattana, Duangkamon Baowan, Barry Cox
Mechanics Of Fullerene-Carbon Nanotube Bundle Oscillators, James Hill, Ngamta Thamwattana, Duangkamon Baowan, Barry Cox
Dr Ngamta Thamwattana
Carbon nanostructures, such as nanotubes and fullerenes, are of considerableinterest to a wide range of research communities. Owing to their unique properties, a numberof applications involving these structures have been proposed, one of which is the so-callednano-scaled oscillators, for which the resultant oscillatory frequencies are in the gigahertzrange. The phenomena of the gigahertz oscillations have also led to the possible creation offuture devices, such as ultra-fast optical filters and ultra-sensitive nano-antennae. In thispaper we present recent developments in this area and review the authors recent work,where we investigate the mechanics of a new type of gigahertz oscillator comprising afullerene C60 …
Mathematical Modelling For A C60 Carbon Nanotube Oscillator, Barry Cox, Ngamta Thamwattana, James Hill
Mathematical Modelling For A C60 Carbon Nanotube Oscillator, Barry Cox, Ngamta Thamwattana, James Hill
Dr Ngamta Thamwattana
The discovery of fullerenes C60 and carbon nanotubes has created an enormous impact on nanotechnology. Because of their unique mechanical and electronic properties, such as low weight, high strength, flexibility and thermal stability, fullerenes C60 and carbon nanotubes are of considerable interest to researchers from many scientific areas. One problem that has attracted much attention is the creation of gigahertz oscillators. While there are difficulties for micromechanical oscillators, or resonators, to reach a frequency in the gigahertz range, it is possible for nanomechanical systems to achieve this. A number of studies have found that the sliding of the inner-shell inside …
Orientation Of A Benzene Molecule Inside A Carbon Nanotube, Thien Tran-Duc, Ngamta Thamwattana, James Hill
Orientation Of A Benzene Molecule Inside A Carbon Nanotube, Thien Tran-Duc, Ngamta Thamwattana, James Hill
Dr Ngamta Thamwattana
Benzene molecules confined in carbon nanotubes of varying radii are employed as semiconductors in electronic nanodevices, and their orientation determines the electrical properties of the system. In this paper, we investigate the interaction energy of all the possible configurations of a benzene molecule inside various carbon nanotubes and then we determine the equilibrium configuration. We adopt the continuous approach together with the semi-empirical Lennard-Jones potential function to model van der Waals interaction between a benzene molecule and a carbon nanotube. This approach results in an analytical expression, which accurately approximates the interaction energy and can be readily used to generate …
Spherical And Spheroidal Fullerenes Entering Carbon Nanotubes, James Hill, Ngamta Thamwattana, Barry Cox
Spherical And Spheroidal Fullerenes Entering Carbon Nanotubes, James Hill, Ngamta Thamwattana, Barry Cox
Dr Ngamta Thamwattana
A continuous model of a fullerene inside a carbon nanotube and for which both the fullerene and carbon nanotube are treated as smooth surfaces with uniform atomic number densities and the van der Waals interaction is formulated using a 6-12 Lennard-Jones potential. From the model we derive acceptance conditions and suction energies for C60, C70 and C80 fullerenes. We show that for these systems where the fullerenes are not accepted by the nanotube, then the suction energy is particularly sensitive to the equatorial semi-axis length b. Alternatively, when the nanotube does accept the fullerene then an approximately equal suction energy …
Sulfur-Mesoporous Carbon Composites In Conjunction With A Novel Ionic Liquid Electrolyte For Lithium Rechargeable Batteries, Jun Chen, Syed Ashraf, Sau Yen Chew, See How Ng, David Wexler, Jiazhao Wang, Hua Liu, Zhengwei Zhao, Shulei Chou
Sulfur-Mesoporous Carbon Composites In Conjunction With A Novel Ionic Liquid Electrolyte For Lithium Rechargeable Batteries, Jun Chen, Syed Ashraf, Sau Yen Chew, See How Ng, David Wexler, Jiazhao Wang, Hua Liu, Zhengwei Zhao, Shulei Chou
Shulei Chou
Sulfur coated mesoporous carbon (S-C) composites have been synthesized and physically characterized by scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and thermogravimetric analysis. Firstly, the electrochemical properties of the S-C composite cathode materials were tested in a conventional electrolyte consisting of 1 mol/L lithium bistrifluormethanesulfonimidate in poly(ethylene glycol) dimethyl ether to compare them with pure sulphur electrode. The capacity and cyclic stability of the S-C composite were improved. Then the S-C composites were tested in a novel ionic liquid electrolyte consisting of 1-ethyl-3-methylimidazolium bis(trifluromethanesulfonyl)imide and lithium
Flexible Free-Standing Carbon Nanotube Films For Model Lithium-Ion Batteries, Jun Chen, Sau Yen Chew, See How Ng, Jiazhao Wang, Hua Liu, P Novak, F Krumeich, Shulei Chou
Flexible Free-Standing Carbon Nanotube Films For Model Lithium-Ion Batteries, Jun Chen, Sau Yen Chew, See How Ng, Jiazhao Wang, Hua Liu, P Novak, F Krumeich, Shulei Chou
Shulei Chou
No abstract provided.
One-Step Spray Pyrolysis Synthesized Cuo-Carbon Composite Combined With Carboxymethyl Cellulose Binder As Anode For Lithium-Ion Batteries, Chao Zhong, Jia-Zhao Wang, Xuan-Wen Gao, Shulei Chou, Konstantin Konstantinov, Hua Liu
One-Step Spray Pyrolysis Synthesized Cuo-Carbon Composite Combined With Carboxymethyl Cellulose Binder As Anode For Lithium-Ion Batteries, Chao Zhong, Jia-Zhao Wang, Xuan-Wen Gao, Shulei Chou, Konstantin Konstantinov, Hua Liu
Shulei Chou
Copper oxide-carbon composite with hollow sphere structure has been synthesized by a one-step spray pyrolysis method and tested as anode material for lithium-ion batteries. Different analytical methods, including X-ray powder diffraction, scanning electron microscopy, energy-dispersive X-ray spectrometry, thermogravimetric analysis, and systematic electrochemical tests were performed. The results demonstrate that the CuO-carbon composite in conjunction with carboxymethyl cellulose (CMC) binder has an excellent electrochemical performance, with a capacity of 577 mAh g-1 up to 100 cycles. The usage of the water soluble binder, CMC, not only obviously improves the electrochemical performance, but also makes the electrode fabrication process much easier and …
The Loss Of Carbon Dioxide From Activated Perbenzoate Anions In The Gas Phase: Unimolecular Rearrangement Via Epoxidation Of The Benzene Ring, David G. Harman, Aravind Ramachandran, Michelle Gracanin, Stephen J. Blanksby
The Loss Of Carbon Dioxide From Activated Perbenzoate Anions In The Gas Phase: Unimolecular Rearrangement Via Epoxidation Of The Benzene Ring, David G. Harman, Aravind Ramachandran, Michelle Gracanin, Stephen J. Blanksby
Stephen Blanksby
The unimolecular reactivities of a range of perbenzoate anions (X−C6H5CO3-), including the perbenzoate anion itself (X = H), nitroperbenzoates (X = para-, meta-, ortho-NO2), and methoxyperbenzoates (X = para-, meta-OCH3) were investigated in the gas phase by electrospray ionization tandem mass spectrometry. The collision-induced dissociation mass spectra of these compounds reveal product ions consistent with a major loss of carbon dioxide requiring unimolecular rearrangement of the perbenzoate anion prior to fragmentation. Isotopic labeling of the perbenzoate anion supports rearrangement via an initial nucleophilic aromatic substitution at the ortho carbon of the benzene ring, while data from substituted perbenzoates indicate that …
Zawartość Węgla I Siarki W Pyle Pm2,5 I Pm10 W Powietrzu W Centrum Krakowa, Monika Dziugieł, Marek Bogacki, Robert Oleniacz, Marian Mazur
Zawartość Węgla I Siarki W Pyle Pm2,5 I Pm10 W Powietrzu W Centrum Krakowa, Monika Dziugieł, Marek Bogacki, Robert Oleniacz, Marian Mazur
Robert Oleniacz
This paper presents the results of the PM2.5 and PM10 mass concentration measurements in an urban air and results obtained from the additional chemical analysis concerning carbon and sulfur content of the collected dust samples. Dust samples were collected at the measuring point located on the roof of five-storey building at the AGH University of Science and Technology in Krakow, Poland (the center of the urban area of the city). In the scope of this study the relations between the carbon and sulfur content within the collected dust samples were determined in the function of the dust fraction content and …
An Investigation Of Voluntary Corporate Greenhouse Gas Emissions Reporting In A Market Governance System: Australian Evidence, Michaela Rankin, Carolyn Windsor, Dina Wahyuni
An Investigation Of Voluntary Corporate Greenhouse Gas Emissions Reporting In A Market Governance System: Australian Evidence, Michaela Rankin, Carolyn Windsor, Dina Wahyuni
Carolyn Windsor
Purpose – Institutional governance theory is used to explain voluntary corporate greenhouse gas (GHG) reporting in the context of a market governance system in the absence of climate change public policy. This paper seeks to hypothesise that GHG reporting is related to internal organisation systems, external privately promulgated guidance and EU ETS trading.
Design/methodology/approach – A two-stage approach is used. The initial model examines whether firms’ GHG disclosures are associated with internal organisation systems factors: environmental management systems (EMS), corporate governance quality and environmental management committees as well as external private guidance provided by the Global Reporting Initiative (GRI) and …
The Density Factor In The Synthesis Of Carbon Nanotube Forest By Injection Chemical Vapor Deposition, R. W. Call, C. G. Read, C. Mart, T. -C. Shen
The Density Factor In The Synthesis Of Carbon Nanotube Forest By Injection Chemical Vapor Deposition, R. W. Call, C. G. Read, C. Mart, T. -C. Shen
T. -C. Shen
Beneath the seeming straight-forwardness of growing carbon nanotube(CNT) forests by the injection chemical vapor deposition(CVD) method, control of the forest morphology on various substrates is yet to be achieved. Using ferrocene dissolved in xylene as the precursor, we demonstrate that the concentration of ferrocene and the injection rate of the precursor dictate the CNT density of these forests. However, CNT density will also be affected by the substrates and the growth temperature which determine the diffusion of the catalyst adatoms. The CNT growth rate is controlled by the temperature and chemical composition of the gases in the CVD reactor. We …