Engineering Commons^™

Nanomanipulation Of Individual Carbon Nanotubes, Rishi Gupta, Taylor M. Cavanah, Marc In Het Panhuis

Australian Institute for Innovative Materials - Papers

Extended abstract of a paper presented at Microscopy and Microanalysis 2004 in Savannah, Georgia, USA, August 1-5, 2004.

Nano-Patterning And Manipulation Of Genetically Engineered Virus Nanoblocks, Moon J. Kim, Marc In Het Panhuis, R Gupta, A S. Blum, B R. Ratna, Bruce E. Gnade, Robert Wallace

Australian Institute for Innovative Materials - Papers

Extended abstract of a paper presented at Microscopy and Microanalysis 2004 in Savannah, Georgia, USA, August 1-5, 2004.

Distributed Polarizability Analysis For Para-Nitroaniline And Meta-Nitroaniline: Functional Group And Charge-Transfer Contributions, Marc In Het Panhuis, R W. Munn, P L A Popelier

Australian Institute for Innovative Materials - Papers

Topological partitioning of electronic properties is used to investigate the polarizability of para-nitroaniline and meta-nitroaniline. The distributed polarizabilities for atoms are combined into total local or generalized distributed contributions for the amino, ring, and nitro functional groups; generalized distributed group contributions have not been calculated before. The local group contributions are transferable between the two molecules only when charge transfer is suppressed, but the generalized distributed contributions prove surprisingly similar in the two molecules, apparently because they treat charge-transfer contributions explicitly.

Hook Crack In Electric Resistance Welding Line Pipe Steel, Sima Aminorroaya-Yamini, Hossein Edris, Mehrdad Fatahi

Australian Institute for Innovative Materials - Papers

One of the production methods for API line pipe steel is electric resistance welding (ERW). This kind of pipes is encountered with hook crack which is one of the defects that is observed in the upset zone of ERW pipes, detecting by ultrasonic inspection. Hook crack is a small crack following the weld flow lines and if severe enough, opened up at the pipe surface. These defects were commonly associated with sulphide stringers and non metallic oxide inclusions.

In this research, welds containing hook cracks were obtained from Ahvaz pipe making factory. Scanning electron microscope (SEM) examination showed that all …

N-Benzoylthiourea, Pawel Wagner, Sabina Niemczyk-Baltoro, Maciej Kubicki

Australian Institute for Innovative Materials - Papers

In the title compound, C₈H₈N₂OS, strong intramolecular N—H⋯O hydrogen bonds [N⋯O = 2.669 (3) and 2.618 (3) Å] form almost planar six-membered rings and enforce the conformation of the mol­ecule. Two kinds of intermolecular N—H⋯S hydrogen bonds [N⋯S = 3.309 (3)–3.456 (2) Å] between two symmetry-independent mol­ecules form consecutive dimers that expand in ribbons along the [100] direction.

2,5-Di-2-Thienylthiazolo[4,5-D]Thiazole, Pawel Wagner, Maciej Kubicki

Australian Institute for Innovative Materials - Papers

The mol­ecules of the title compound, C₁₂H₆N₂S₄, lie on centres of symmetry. The thio­phene and thia­zole rings are almost planar and their planes make a dihedral angle of 1.68 (8)°. In the crystal structure, there is a relatively short intermolecular S⋯S contact distance of 3.5786 (9) Å.

Improving The Mechanical Properties Of Single-Walled Carbon Nanotube Sheets By Intercalation Of Polymeric Adhesives, Jonathan N. Coleman, Werner J. Blau, Alan B. Dalton, Edgar Munoz, Steve Collins, Bog G. Kim, Joselito M. Razal, Miles Selvidge, Guillermo Vieiro, Ray Baughman

Australian Institute for Innovative Materials - Papers

Organic polymers, such as poly(vinyl alcohol), poly(vinyl pyrrolidone), and poly(styrene), were intercalated into single-walled carbon nanotube sheets by soaking the sheets in polymer solutions. Even for short soak times, significant polymer intercalation into existing free volume was observed. Tensile tests on intercalated sheets showed that the Young's modulus, strength, and toughness increased by factors of 3, 9, and 28, respectively, indicating that the intercalated polymer enhances load transmission between nanotubes.

Zinc Doping Effects On The Structure, Transport And Magnetic Properties Of La0.7sr0.3mn1-Xznxo3 Manganite Oxide, E V. Sotirova-Haralambeva, Xiaolin Wang, Hua-Kun Liu, Tania M. Silver, Konstantin Konstantinov, Josip Horvat

Australian Institute for Innovative Materials - Papers

The processing, microstructures and properties of La_0.7Sr_0.3Mn_1−xZn_xO₃ perovskite manganite, with x=0, 0.1, 0.2, and 0.3 have been investigated. X-ray diffraction, scanning electron microscopy (SEM) and other characterisation methods were used to study the relations of microstructure and properties. The X-ray powder diffraction results show a single phase for the 0<x<0.3 region that confirms the zinc incorporation into the Mn site. The SEM images with magnification 1500× indicate that the studied system is a single phase. The transport measurements show decreasing of insulator to metal transition temperature, T_t, with increasing the zinc concentration on the Mn site, while the resistivity increases with …

1,4-Bis[(1-Methyl-1-Phenylethyl)Peroxymethyl]Benzene, Nikodem Kuznik, Jan Zawadiak, Angelika Wieckol, Danuta Gilner, Pawel Wagner, Maciej Kubicki

Australian Institute for Innovative Materials - Papers

The title compound, C₂₆H₃₀O₄, is one of the first alkyl bis-peroxides to be structurally characterized. The mol­ecule lies on a centre of inversion and therefore the terminal phenyl rings are parallel. Although there are three aromatic rings in the mol­ecule, the C—O—O—C torsion angle of 163.10 (10)° is close to the value found in Me₃COOCMe₃.

The Effect Of Foamy Slag In Electric Arc Furnaces On Electric Energy Consumption, Sima Aminorroaya-Yamini, Hossein Edris

Australian Institute for Innovative Materials - Papers

In electric arc furnace steelmaking units, the essential parameters that considered important are reducing price, increasing production and decreasing environmental pollution. Electric arc furnaces are the largest users of electric energy in industry. The most important techniques that can be used to reduce the electric energy consumption in electric arc furnaces are scrap preheating, stirring, use of burners and hot charge and foamy slag.

Between these methods, use of foamy slag is the most useful and economic factor. Foamy slag can reduce the amount of energy, electrods, refractory consumption, tap to tap time and increases productivity. In this research, method …

Geometric Edge Barrier In The Shubnikov Phase Of Type Ii Superconductors, E Brandt

Australian Institute for Innovative Materials - Papers

In type-II superconductors the magnetic response can be irreversible for two different reasons: vortex pinning and barriers to flux penetration. Even without bulk pinning and in the absence of a microscopic Bean–Livingston surface barrier for vortex penetration, superconductors of nonellipsoidal shape can exhibit a large geometric barrier for flux penetration. This edge barrier and the resulting irreversible magnetization loops and flux-density profiles are computed from continuum electrodynamics for superconductor strips and disks of constant thickness, both without and with bulk pinning. Expressions are given for the field of first flux entry H_en and for the reversibility field H_{rev …}

Vortex Matter In Superconductors, V M Pan, Alexey Pan

Australian Institute for Innovative Materials - Papers

The behavior of the ensemble of vortices in the Shubnikov phase in biaxially oriented films of the high-temperature superconductor YBa₂Cu₃O_7−δ(YBCO) in an applied magnetic field is investigated for different orientations of the field. The techniques used are the recording of the current–voltage characteristics in the transport current and of resonance curves and damping of a mechanical oscillator during the passage of a transport current. It is shown that the behavior of the vortex ensemble in YBCOfilms, unlike the case of single crystals, is determined by the interaction of the vortices with linear defects—edge dislocations, …

Distributed Polarizability Of The Water Dimer: Field-Induced Charge Transfer Along The Hydrogen Bond, Marc In Het Panhuis, P L A Popelier, R W. Munn, J G. Angyan

Australian Institute for Innovative Materials - Papers

The topological partitioning of electronic properties approach at Hartree-Fock level is used to investigate charge transfer response in a water dimer. Distributed polarizability components are employed to calculate the change in electron density under external fields. Field-induced charge flow between the water monomers is most significant along the direction of the hydrogen bond. The molecular polarizability of the molecules in the dimer is reduced owing to formation of the hydrogen bond.

Two 1-Substituted 4-Nitroimidazoles, Maciej Kubicki, Teresa Borowiak, Jerzy Suwinski, Pawel Wagner

Australian Institute for Innovative Materials - Papers

Crystalline 4-nitro-1-phenyl­imidazole, C₉H₇N₃O₂, (I), and 4′-­nitro-1-phenyl-4,1′-bii­imidazole, C₁₂H₉N₅O₂, (II), contain C—H⃛O and C—H⃛N hydrogen bonds, connecting the mol­ecules into infinite chains. The aromatic fragments in both compounds are nearly planar. The dihedral angles between the benzene and imidazole rings are 26.78 (5)° in (I) and 29.36 (8)° in (II).

Population Inversion In An Optically Pumped Single Quantum Well, Timoghy J. Green, Wen Xu

Australian Institute for Innovative Materials - Papers

An optically pumped intersubband laser generator is proposed in which the continuum states above an Al_0.2Ga_0.8As–GaAs–Al_0.2Ga_0.8As single quantum well with a width of L=17 nm serve as the highest level in a four-level laser system. The design allows much greater flexibility in the choice of pumping source and simplifies considerably the device fabrication. We have obtained the electronic subband structure of the proposed device and utilized a simple rate equation approach to examine the electron density in different states under optical pumping.

Microscopic Treatment Of Substrate Effects On Linear And Quadratic Optical Response Of Model Langmuir-Blodgett Multilayers, Marc In Het Panhuis, R W. Munn

Australian Institute for Innovative Materials - Papers

Microscopic calculations are reported of linear and quadratic nonlinear optical response in model Langmuir-Blodgett films on a substrate, which is treated by the method of images. The effect of the substrate is significant in the first two layers, and is greatest for tilted molecules with their head groups adjacent to the substrate. The main qualitative effect is to lower the symmetry relative to a free-standing film. Calculations for stearic acidfilms show that the substrate effect is most important for molecules with nonuniform response on a metallic substrate.

Microscopic Calculations Of Linear And Quadratic Optical Response In Model Langmuir-Blodgett Multilayers, Marc In Het Panhuis, R W. Munn

Australian Institute for Innovative Materials - Papers

Microscopic calculations are reported of linear and quadratic nonlinear optical response in Langmuir–Blodgett films. The films are modeled as ordered layers of molecules that can tilt from the vertical and have a higher polarizability and first hyperpolarizability in the head than in the tail. The local electric field varies little after the first layer and negligibly after the second, which simplifies the analysis. Tilted two-layer Y-type films can have quadratic susceptibility components as large as X- or Z-type ones. Overall the results provide a systematic account of the linear and nonlinear optical properties as a function of …

Asymmetry And Rectification In The Tunnel Current Of A Nanometer-Sized Metal-Conjugated Polymer-Metal Junction, S T. Yau, C Zhang, Peter Innis

Australian Institute for Innovative Materials - Papers

Electron transport processes of a nanometer metal-conjugated polymer–metal tunnel junction have been probed using a scanning tunneling microscope. The tunnel current of the junction shows two effects. The appearance of an asymmetry in the tunnel current indicates that the junction transport mechanism is different from that for which tunneling occurs directly between two metallic electrodes. Thus, understanding of the asymmetry and hence the transport mechanism demands a detailed description of the metal–polymer interface. By applying the theories of the metal–semiconductor interface to the tunnel junction, we show the presence of an asymmetric electrostatic potential-energy profile, which, together with the metal-induced …

Analysis Of Linear And Quadratic Optical Response Of Mixed Langmuir-Blodgett Films Of Stearic Acid And 5-Ct, Marc In Het Panhuis, R W. Munn

Australian Institute for Innovative Materials - Papers

Published experimental optical second-harmonic generation (SHG) results for mixed films formed between stearic acid and the mesogen 5-CT (4^″-n-pentyl-4-cyano-p-terphenyl) are reanalyzed. Experimental refractive index results for the pure films are used to deduce molecular polarizabilities in order to calculate local fields. At low and high fractions of 5-CT, a consistent interpretation of the SHG is obtained using a mean molecular response based on a fixed axial hyperpolarizabilityβ_LLL for the mesogen, but at high mesogen fractions molecular tilt makes small off-diagonal componentsβ_LLM≈−β_LLL/40 essential. At intermediate fractions the treatment can interpret …

A Simulation Study Of The Kinetics Of Passage Of Co2 And N2 Through The Liquid/Vapor Interface Of Water, T Somasundaram, Marc In Het Panhuis, R M. Lynden-Bell, C H. Patterson

Australian Institute for Innovative Materials - Papers

The rate of passage of molecules of carbon dioxide and nitrogen through the vapor–liquid interface of water at 300 K is studied by simulation. Previous work has established the form of the free energy profile which has a minimum when the solute molecule is on the surface and a barrier between this state and solution in the bulk liquid. In one set of simulations, trajectories were initiated in the gas phase. From these, the average lifetime of molecules in the surface is determined to be considerably longer than the inverse of the energy relaxation rate, so that the sticking coefficient …

A Child's View Of Foam, Marc In Het Panhuis

Australian Institute for Innovative Materials - Papers

"Are you a grown-up?" I looked up, or more precisely down, into the eyes of a child. He had good reason to ask this since I was playing with bubbles at an exhibition for very young scientists. What attracts them? What does not? Physicists have been arguing over whether or not to consider it a duty to encourage children to enter physics. I would like to describe the actual experience of standing among the young and curious.