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Full-Text Articles in Engineering
Magnetopolaron Interactions In N-Type Indium Phosphide, R. A. Lewis, P. E. Simmonds, Y. J. Wang
Magnetopolaron Interactions In N-Type Indium Phosphide, R. A. Lewis, P. E. Simmonds, Y. J. Wang
Faculty of Engineering - Papers (Archive)
Broadband far-infrared absorption spectroscopy is used to investigate n-type indium phosphide in magnetic fields of up to 30 T. The large energy range 2–14 Ry and the large magnetic field range 03 employed permit the observation of a rich variety of magnetopolaron interactions. We report on the magnetopolaron effect for bound states in InP, beginning with the coupling of the 2p+ state with the 1s+LO phonon state. We further observe the magnetopolaron effect associated with the metastable state 210. In addition we report i) the re-emergence of the 210 impurity state transition beyond the LO phonon manifold, ii) the possible …
Reflections Of Active Galactic Nucleus Outbursts In The Gaseous Atmosphere Of M87, W. Forman, P. Nulsen, S. Heinz, F. Owen, J. Eilek, A. Vikhlinin, M. Markevitch, R. Kraft, E. Churazov, C. Jones
Reflections Of Active Galactic Nucleus Outbursts In The Gaseous Atmosphere Of M87, W. Forman, P. Nulsen, S. Heinz, F. Owen, J. Eilek, A. Vikhlinin, M. Markevitch, R. Kraft, E. Churazov, C. Jones
Faculty of Engineering - Papers (Archive)
We combined deep Chandra, ROSAT HRI, and XMM-Newton observations of M87 to study the impact of active galactic nucleus (AGN) outbursts on its gaseous atmosphere. Many X-ray features appear to be a direct result of repetitive AGN outbursts. In particular, the X-ray cavities around the jet and counterjet are likely due to the expansion of radio plasma, while rings of enhanced emission at 14 and 17 kpc are probably shock fronts associated with outbursts that began 1–2 × 107 yr ago. The effects of these shocks are also seen in brightenings within the prominent X-ray arms. On larger scales, ∼50 …
Strong Terahertz Emission From (100) P-Type Inas, Rajind Mendis, M. L. Smith, L. J. Bignell, R. Vickers, R. A. Lewis
Strong Terahertz Emission From (100) P-Type Inas, Rajind Mendis, M. L. Smith, L. J. Bignell, R. Vickers, R. A. Lewis
Faculty of Engineering - Papers (Archive)
Terahertz emission has been observed from (100) Zn-acceptor-doped InAs under illumination by fs pulses of near-infrared radiation. Turning the crystal about the surface normal produces two maxima per rotation, whether the angle of incidence is 45° or 75°, in contrast to (111) p-InAs, where three maxima per rotation have been reported. The emitted terahertz power has a quadratic variation with the pump power and decreases with increasing temperature in the range 20–300 K. This behavior is consistent with a photocurrent surge being the dominant terahertz generating mechanism at low excitation fluences. The p-type InAs generates about two orders of magnitude …
Monitoring Structural Degradation Of Rail Pads In Laboratory Using Impact Excitation Technique, S. Kaewunruen, Alexander Remennikov
Monitoring Structural Degradation Of Rail Pads In Laboratory Using Impact Excitation Technique, S. Kaewunruen, Alexander Remennikov
Faculty of Engineering - Papers (Archive)
In ballasted railway track, the deterioration of a sleeper and ballast support usually occurs due to both regular and irregular wheel/rail interactions. The repeated impact of train wheels over sleepers can reduce the lifetime of a sleeper and degrade ballast. To attenuate the effect of the impact loads on concrete sleepers, the resilient rail seat pads are used. After a certain time in service conditions, the worn rail pads have to be replaced. Assessment of the condition of rail pads is of great importance to track engineers and plays an important role in the overall track maintenance cost. A non-destructive …
Tsunami Affected Coastal Soil Disturbance And Implications On Reconstruction With Special Reference To Low-Cost Dwellings And Rail Tracks, Buddhima Indraratna, Mohamed A. Shahin, Cholachat Rujikiatkamjorn, Hadi Khabbaz
Tsunami Affected Coastal Soil Disturbance And Implications On Reconstruction With Special Reference To Low-Cost Dwellings And Rail Tracks, Buddhima Indraratna, Mohamed A. Shahin, Cholachat Rujikiatkamjorn, Hadi Khabbaz
Faculty of Engineering - Papers (Archive)
On 26 December 2004, the largest earthquake for more than 4 decades (magnitude 9.0) occurred between the Australian and Eurasian plates in the Indian Ocean (along the overly stressed Sunda trench) to the west of Aceh Province (Northern Sumatra). The quake triggered a series of waves that increased in height rapidly close to the shore (tsunami) spreading thousands of kilometers across the Bay of Bengal. In the Eastern and Southern coastal belt of Sri Lanka, the floodwaters reached almost 1 km inland, causing unprecedented damage to infrastructure and over 4000 fatalities. Widespread destruction included several kilometres of rail tracks, dislocating …
Seismic Lateral Response Of Piles In Liquefying Soil, D. S. Liyanapathirana, H. G. Poulos
Seismic Lateral Response Of Piles In Liquefying Soil, D. S. Liyanapathirana, H. G. Poulos
Faculty of Engineering - Papers (Archive)
Soil liquefaction is one of the major factors affecting the behavior of piles founded in seismically active areas. Although methods are available for seismic analysis of pile foundations, in many of them, the supporting soil is assumed to be an elastic material. Here a numerical model is presented which takes into account the reduction of soil stiffness and strength due to pore pressure generation and subsequent soil liquefaction, in addition to the material nonlinearity. Results obtained from the new method are compared with centrifuge test data and show excellent agreement with the observed pile behavior during these tests. To investigate …
Electronic Efficiency In Nanostructured Thermionic And Thermoelectric Devices, Mark F. O'Dwyer, R. A. Lewis, C. Zhang, T. E. Humphrey
Electronic Efficiency In Nanostructured Thermionic And Thermoelectric Devices, Mark F. O'Dwyer, R. A. Lewis, C. Zhang, T. E. Humphrey
Faculty of Engineering - Papers (Archive)
Advances in solid-state device design now allow the spectrum of transmitted electrons in thermionic and thermoelectric devices to be engineered in ways that were not previously possible. Here we show that the shape of the electron energy spectrum in these devices has a significant impact on their performance. We distinguish between traditional thermionic devices where electron momentum is filtered in the direction of transport only and a second type, in which the electron filtering occurs according to total electron momentum. Such “total momentum filtered” thermionic devices could potentially be implemented in, for example, quantum dot superlattices. It is shown that …
Effects Of Collective Excitations On The Quantum Well Intersubband Absorption, X. W. Mi, J. C. Cao, C. Zhang, F. B. Meng
Effects Of Collective Excitations On The Quantum Well Intersubband Absorption, X. W. Mi, J. C. Cao, C. Zhang, F. B. Meng
Faculty of Engineering - Papers (Archive)
The dependence of the intersubband absorption spectra on the Coulomb interaction and quantum well (QW) width is studied. Rather than following the Fermi–Dirac distribution, we have solved the intersubband equations of motion to determine the subband population self-consistently. We have gone beyond the linear absorption theory to show the effect of various many-body interactions on the absorption spectra. It is found that the redistribution of electrons in excited states reduces the absorption. Our results indicate that the line shape and peak position are determined by the interplay of different collective excitations, such as the Fermi edge singularity and the intersubband …
Silicon/Disordered Carbon Nanocomposites For Lithium-Ion Battery Anodes, Z. P. Guo, E. Milin, J. Z. Wang, Jun Chen, Hua-Kun Liu
Silicon/Disordered Carbon Nanocomposites For Lithium-Ion Battery Anodes, Z. P. Guo, E. Milin, J. Z. Wang, Jun Chen, Hua-Kun Liu
Faculty of Engineering - Papers (Archive)
Silicon/disordered carbon Si-DC nanocomposites have been synthesized by high-energy ballmilling of Si-sucrose and silicon-polyvinyl alcohol followed by pyrolysis under argon flow. The exact disordered carbon content in the as-prepared Si-DC nanocomposites was determined by thermogravimetric analysis for the first time. Based on the thermogravimetric analysis, X-ray diffraction, Raman, and cyclic voltammetric results, we believe that carbon distribution on the Si particles in Si-DC nanocomposite using PVA as the carbon source is more uniform and has higher efficiency than that using sucrose as the carbon source, under the same preparation conditions. The carbon content and the starting polymers significantly affect the …
Structure, Spin Glass, And Spin State In Perovskite Gdco/Sub 1-X/Mn/Sub X/O/Sub 3/ (X /Spl Les/ 0.5), M Mehdi Farhoudi, Xiaolin Wang
Structure, Spin Glass, And Spin State In Perovskite Gdco/Sub 1-X/Mn/Sub X/O/Sub 3/ (X /Spl Les/ 0.5), M Mehdi Farhoudi, Xiaolin Wang
Faculty of Engineering - Papers (Archive)
Perovskite GdCo/sub 1-x/Mn/sub x/O/sub 3/ (x=0.2,0.3,0.4,0.5) compounds have been prepared by solid-state reaction. Structures were characterized using X-ray diffraction and Rietveld Refinement method. The compounds crystallized in orthorhombic with Plmn space group. Crystal lattices decreased with the increase of Mn doping level. DC magnetization and ac susceptibility were studied over a wide temperature range and different frequencies. A typical spin glass state was observed in all samples around the same temperature of 122 K where the compounds turned from paramagnetic to ferromagnetic states. For x
Infrared-Active Phonons Of Perovskite Homn/Sub 1-X/Co/Sub X/O/Sub 3/ (X=0--0.8), Feng Gao, Xiaolin Wang, M Mehdi Farhoudi, R. A. Lewis
Infrared-Active Phonons Of Perovskite Homn/Sub 1-X/Co/Sub X/O/Sub 3/ (X=0--0.8), Feng Gao, Xiaolin Wang, M Mehdi Farhoudi, R. A. Lewis
Faculty of Engineering - Papers (Archive)
Polycrystalline perovskites compounds HoMn/sub 1-x/Co/sub x/O/sub 3/ (x=0--0.8) have been prepared by conventional solid-state reaction. Here, we used far-infrared (FIR) spectroscopy to study infrared active phonon modes and present a comparative analysis of infrared transmission spectra of polycrystalline HoMn/sub 1-x/Co/sub x/O/sub 3/ (x=0--0.8). The data indicated that phonon modes significantly changed with increase of cobalt doping level. Four main bands were assigned as external, torsional, bending and stretching bands. The external vibration energy remain same at /spl omega//sub 1//spl sim/190 cm/sup -1/ for Co doping x/spl les/0.5 and shift to higher energy for x>0.5. Torsional and bending bands exhibit …
Modelling Blast Loads On Buildings In Complex City Geometries, Alexander Remennikov, T. A. Rose
Modelling Blast Loads On Buildings In Complex City Geometries, Alexander Remennikov, T. A. Rose
Faculty of Engineering - Papers (Archive)
This paper is concerned with an accurate prediction of the effects of adjacent structures on the blast loads on a building in urban terrain. Blast loadings on structures have typically been evaluated using empirical relationships. These relationships assume that there are no obstacles between the charge and the target. In real situations, the actual blast loads can either be reduced due to shadowing by other buildings or can be enhanced due to the presence of other buildings in the vicinity. Results of the numerical simulations presented in this study for multiple buildings in an urban environment have demonstrated the importance …
Strength Analysis Of Steel–Concrete Composite Beams In Combined Bending And Shear, Q. Q. Liang, B. Uy, M. A. Bradford, H. R. Ronagh
Strength Analysis Of Steel–Concrete Composite Beams In Combined Bending And Shear, Q. Q. Liang, B. Uy, M. A. Bradford, H. R. Ronagh
Faculty of Engineering - Papers (Archive)
Despite experimental evidences, the contributions of the concrete slab and composite action to the vertical shear strength of simply supported steel–concrete composite beams are not considered in current design codes, which lead to conservative designs. In this paper, the finite element method is used to investigate the flexural and shear strengths of simply supported composite beams under combined bending and shear. A three-dimensional finite element model has been developed to account for geometric and material nonlinear behavior of composite beams, and verified by experimental results. The verified finite element model is than employed to quantify the contributions of the concrete …
Terahertz Emission From (100) P-Ina, M. L. Smith, R. Mendis, R. E. M. Vickers, R. A. Lewis
Terahertz Emission From (100) P-Ina, M. L. Smith, R. Mendis, R. E. M. Vickers, R. A. Lewis
Faculty of Engineering - Papers (Archive)
Terahertz emission from (100) p-type InAs illuminated by ultrafast near-infrared pulses is investigated. A two-fold rotational symmetry was observed when rotated about the surface normal. A quadratic relationship was found for the emission dependence on optical pump power. These suggest the presence of photo-carrier transport and optical rectification mechanisms. The InAs emission was found to exceed that of a blackbody radiator for frequencies below 1 THz for nominal input power levels. The generated power was found to be roughly two orders of magnitude greater than a 1mm ZnTe emitter.
Application Of Experimental Modal Testing For Estimating Dynamic Properties Of Structural Components, S. Kaewunruen, Alexander Remennikov
Application Of Experimental Modal Testing For Estimating Dynamic Properties Of Structural Components, S. Kaewunruen, Alexander Remennikov
Faculty of Engineering - Papers (Archive)
In this paper, experimental modal testing is used in relation to solving problems in railway engineerin. The railway engineering problem is related to identification of the dynamic properties of the railway track components in laboratory and in-situ conditions. This information is critically needed at the moment, in order to develop the Australian track model. In particular, the modal testing is applied to determine the dynamic stiffness and damping parameters of rail pads of various ages to investigate their degree of degradation with time in service. The frequency ranges used in the tests were different reflecting the range of resonant frequencies …
Investigation Of Vibration Characteristics Of Prestressed Concrete Sleepers In Free-Free And In-Situ Conditions, Alexander Remennikov, Sakdirat Kaewunruen
Investigation Of Vibration Characteristics Of Prestressed Concrete Sleepers In Free-Free And In-Situ Conditions, Alexander Remennikov, Sakdirat Kaewunruen
Faculty of Engineering - Papers (Archive)
This paper presents results of an experimental modal analysis of prestressed concrete sleepers in both free-free and in-situ conditions. Four types of prestressed concrete sleepers were provided by the Australian manufacturers. The concrete sleepers were tested using an impact hammer excitation technique over the frequency range of interest: 0 to1600 Hz. Frequency response functions (FRFs) were measured using the Bruel&Kjaer PULSE dynamic analyser. The FRFs were processed using the STARModal analysis package to identify natural frequencies and the corresponding mode shapes for the sleepers. The conclusions are presented on the effect of boundary conditions on the dynamic properties of prestressed …
Measurement Of Pore Water Pressure Of Clay-Infilled Rock Joints During Triaxial Shearing, Buddhima Indraratna, J. Mylvaganam
Measurement Of Pore Water Pressure Of Clay-Infilled Rock Joints During Triaxial Shearing, Buddhima Indraratna, J. Mylvaganam
Faculty of Engineering - Papers (Archive)
Joints existing within a rock mass are normally filled with fine materials such as clay and silt, which decrease its ultimate strength and make it easier to deform. The shear behaviour of infilled rock joints is controlled by several parameters, such as infill thickness, joint roughness and drainage conditions (Ladanyi & Archambault, 1977; Lama, 1978; de Toledo & de Freitas, 1993; Indraratna et al., 2005). If the infill material is saturated and drainage is impeded, pore water pressure within the infilled joint will build up and change during shear displacement. The importance of pore water pressure in the hydromechanical stability …
Enhanced Stiffness Modeling, Identification And Characterization For Robot Manipulators, G. Alici, B. Shirinzadeh
Enhanced Stiffness Modeling, Identification And Characterization For Robot Manipulators, G. Alici, B. Shirinzadeh
Faculty of Engineering - Papers (Archive)
This paper presents the enhanced stiffness modeling and analysis of robot manipulators, and a methodology for their stiffness identification and characterization. Assuming that the manipulator links are infinitely stiff, the enhanced stiffness model contains: 1) the passive and active stiffness of the joints and 2) the active stiffness created by the change in the manipulator configuration, and by external force vector acting upon the manipulator end point. The stiffness formulation not accounting for the latter is known as conventional stiffness formulation, which is obviously not complete and is valid only when: 1) the manipulator is in an unloaded quasistatic configuration …
Determination Of Dynamic Properties Of Rail Pads Using An Instrumented Hammer Impact Technique, Alexander Remennikov, Sakdirat Kaewunruen
Determination Of Dynamic Properties Of Rail Pads Using An Instrumented Hammer Impact Technique, Alexander Remennikov, Sakdirat Kaewunruen
Faculty of Engineering - Papers (Archive)
The repeated impact of train wheels over sleepers can reduce the lifetime of a sleeper and degrade ballast. In more extreme cases it can lead to the breakdown of the concrete sleeper. Concrete sleepers are rigid compared to steel and wooden sleepers and therefore it is necessary to provide impact attenuation to prevent premature breakdown of the concrete. One of the measures employed to attenuate the effect of the impact loads on concrete sleepers has been the use of the resilient rail seat pads. Numerous analytical and numerical models have been formulated to investigate the dynamic behaviour of railway track …
The Cluster-Scale Agn Outburst In Hydra A, P. Nulsen, B. R. Mcnamara, M. W. Wise, L. P. David
The Cluster-Scale Agn Outburst In Hydra A, P. Nulsen, B. R. Mcnamara, M. W. Wise, L. P. David
Faculty of Engineering - Papers (Archive)
Deep Chandra observations of the Hydra A Cluster reveal a feature in the X-ray surface brightness that surrounds the 330 MHz radio lobes of the AGN at the cluster center. Surface brightness profiles of this feature and its close association with the radio lobes argue strongly that it is a shock front driven by the expanding radio lobes. The Chandra image also reveals other new structure on smaller scales that is associated with the radio source, including a large cavity and filament. The shock front extends 200–300 kpc from the AGN at the cluster center, and its strength varies along …
Boundary Shear Stress In Spatially Varied Flow With Increasing Discharge, M. H. Khiadani, S. Beecham, J. Kandasamy, Muttucumaru Sivakumar
Boundary Shear Stress In Spatially Varied Flow With Increasing Discharge, M. H. Khiadani, S. Beecham, J. Kandasamy, Muttucumaru Sivakumar
Faculty of Engineering - Papers (Archive)
The distribution of the wall shear stress on the bed and sidewalls of an open channel receiving lateral inflow was obtained from experimental measurements of the distribution of the velocity in the viscous sublayer using a laser doppler velocimeter. The experiments were conducted in a 0.4 m wide by 7.5 m long flume. Lateral inflow was provided into the channel from above via sets of nozzles positioned toward the downstream end of the flume. Lateral inflow was provided over a length of 1.9 m. The results indicate that the local boundary shear stresses are significantly influenced by lateral inflow. The …
Interaction Between Superconductor And Ferromagnetic Domains In Iron Sheath: Peak Effect In Mgb2/Fe Wires, J. Horvat, W. K. Yeoh, Leonie M. Miller
Interaction Between Superconductor And Ferromagnetic Domains In Iron Sheath: Peak Effect In Mgb2/Fe Wires, J. Horvat, W. K. Yeoh, Leonie M. Miller
Faculty of Engineering - Papers (Archive)
Interaction between the superconductor and ferromagnet in MgB2/Fe wires results in either a plateau or a peak effect in the field dependence of transport critical current, Ic(H). This is in addition to magnetic shielding of external field. Current theoretical models cannot account for the observed peak effect in Ic(H). This paper shows that the theoretical explanation of the peak effect should be sought in terms of interaction between superconductor and magnetic domain structure, obtained after re-magnetization of the iron sheath by the self-field of the current. There is a minimum value of critical current, below which the re-magnetization of the …
Magnetic And Transport Properties Of The Layered Perovskite System Sr2–Yyycoo4 (0<=Y<=1), X. L. Wang, E. Takayama-Muromachi
Magnetic And Transport Properties Of The Layered Perovskite System Sr2–Yyycoo4 (0<=Y<=1), X. L. Wang, E. Takayama-Muromachi
Faculty of Engineering - Papers (Archive)
Layered perovskite cobalt oxides Sr2−yYyCoO4 y=0, 0.1, 0.3, 0.5, 0.67, 0.83, and 1 were synthesized under high pressure and high temperature conditions. Structure refinement revealed that these compounds crystallize in K2NiF4-type structures with space group I4/mmm. The parent compound Sr2CoO4 undergoes a ferromagnetic transition with Tc=255 K. The Tc decreases with increasing y to 150 K for y=0.5, and ferromagnetism was not observed for y0.67. Assessment of spin states for Co3+ and Co4+ ions suggested strongly that both are present as intermediate spin states when y0.67 at least for the higher temperature range above Tc. Fairly large negative magnetoresistance was …
Solid-State Thermionics And Thermoelectrics In The Ballistic Transport Regime, T. E. Humphrey, Mark F. O'Dwyer, C. Zhang, R. A. Lewis
Solid-State Thermionics And Thermoelectrics In The Ballistic Transport Regime, T. E. Humphrey, Mark F. O'Dwyer, C. Zhang, R. A. Lewis
Faculty of Engineering - Papers (Archive)
It is shown that the equations for electrical current in solid-state thermionic and thermoelectric devices converge for devices with a width equal to the mean free path of electrons, yielding a common expression for the intensive electronic efficiency in the two types of devices. This result is used to demonstrate that the material parameters for thermionic and thermoelectric refrigerators are equal, rather than differing by a multiplicative factor as previously thought.
Development Of An Equivalent Homogenous Fluid Model For Pseudo-Two-Phase (Air+Water) Flow Through Fractured Rock, Jeffrey Price, Buddhima Indraratna
Development Of An Equivalent Homogenous Fluid Model For Pseudo-Two-Phase (Air+Water) Flow Through Fractured Rock, Jeffrey Price, Buddhima Indraratna
Faculty of Engineering - Papers (Archive)
Fracture flow of two-phase mixtures is particularly applicable to the coal mining and coal bed methane projects in Australia. A one-dimensional steady-state pseudo-two-phase flow model is proposed for fractured rock. The model considers free flow of a compressible mixture of air and water in an inclined planar fracture and is based upon the conservation of momentum and the “cubic” law. The flow model is coupled to changes in the stress environment through the fracture normal stiffness, which is related to changes in fracture aperture. The model represents the individual air and water phases as a single equivalent homogenous fluid. Laboratory …
The Effect Of The Electron Energy Spectrum On Electronic Efficiency And Power In Thermionic And Thermoelectric Devices, Mark F. O'Dwyer, T. E. Humphrey, R. A. Lewis, C. Zhang
The Effect Of The Electron Energy Spectrum On Electronic Efficiency And Power In Thermionic And Thermoelectric Devices, Mark F. O'Dwyer, T. E. Humphrey, R. A. Lewis, C. Zhang
Faculty of Engineering - Papers (Archive)
We show that the details of the energy spectrum of transmitted electrons in thermionic and thermoelectric devices have a significant impact on their performance. We distinguish between traditional thermionic devices where electron momentum is filtered in the direction of transport only and a second type, in which the electron filtering occurs according to total electron momentum. Our main result is that the electronic efficiency of a device is not only improved by reducing the width of the transmission filter, but also strongly depends on whether the transmission probability rises sharply from zero to full transmission. Finally, we comment on the …
Analytical And Numerical Modeling Of Soft Soil Stabilized By Prefabricated Vertical Drains Incorporating Vacuum Reloading, Buddhima Indraratna, I. Sathananthan, Cholachat Rujikiatkamjorn, A. S. Balasubramaniam
Analytical And Numerical Modeling Of Soft Soil Stabilized By Prefabricated Vertical Drains Incorporating Vacuum Reloading, Buddhima Indraratna, I. Sathananthan, Cholachat Rujikiatkamjorn, A. S. Balasubramaniam
Faculty of Engineering - Papers (Archive)
This paper describes the analytical formulation of a modified consolidation theory incorporating vacuum pressure, and numerical modeling of soft clay stabilized by prefabricated vertical drains, with a linearly distributed ~trapezoidal! vacuum pressure for both axisymmetric and plane strain conditions. The effects of the magnitude and distribution of vacuum pressure on soft clay consolidation are examined through average time-dependent excess pore pressure and consolidation settlement analyses. The plane strain analysis was executed by transforming the actual vertical drains into a system of equivalent parallel drain walls by adjusting the coefficient of permeability of the soil and the applied vacuum pressure. The …
Addressing The Geotechnical Challenges Posed By Soft Clays, Buddhima Indraratna
Addressing The Geotechnical Challenges Posed By Soft Clays, Buddhima Indraratna
Faculty of Engineering - Papers (Archive)
[Extract] This Special Issue of the Int. J. Geomech. on soft clay engineering and soft clay improvement is a result of discussion among various colleagues during the Geo-2000 Conference in Melbourne, where the need for a Special Issue on soft clay engineering and improvement was raised. The papers contributed to this Special Issue are selected to reflect the latest developments relating to soft clay engineering and improvement, and address research and applications in many places around the world (e.g., Australia, Finland, The Netherlands, Norway, Singapore, United Kingdom, and the United States). This Special Issue covers a variety of aspects for …
Raman Spectroscopy As A Tool To Study Tic Formation During Controlled Ball Milling, B. H. Lohse, A. Calka, D. Wexler
Raman Spectroscopy As A Tool To Study Tic Formation During Controlled Ball Milling, B. H. Lohse, A. Calka, D. Wexler
Faculty of Engineering - Papers (Archive)
Titanium and carbon elemental powder mixtures with compositions of Ti100–xCx (x=50,40,30) were milled under a helium atmosphere using a magnetoball mill. For Ti50C50 and Ti60C40 powder mixtures, the combined results of external mill temperature monitoring and x-ray diffraction (XRD) analysis indicated that, after a specific incubation period, titanium carbide (TiC) was formed rapidly via a highly exothermic mechanically induced reaction. However, contrary to the current understanding of mechanically induced self-propagating reactions, Raman spectroscopy clearly showed the formation of nonstoichiometric TiC in Ti50C50 and Ti60C40 powders prior to the sudden exothermic event occurring inside the mill. This result has not been …
The Powerful Outburst In Hercules A, P. Nulsen, D. C. Hambrick, B. R. Mcnamara, D. Rafferty, L. Birzan, M. W. Wise, L. P. David
The Powerful Outburst In Hercules A, P. Nulsen, D. C. Hambrick, B. R. Mcnamara, D. Rafferty, L. Birzan, M. W. Wise, L. P. David
Faculty of Engineering - Papers (Archive)
The radio source Hercules A resides at the center of a cooling flow cluster of galaxies at redshift z = 0.154. A Chandra X-ray image reveals a shock front in the intracluster medium (ICM) surrounding the radio source, about 160 kpc from the active galactic nucleus (AGN) that hosts it. The shock has a Mach number of 1.65, making it the strongest of the cluster-scale shocks driven by an AGN outburst found so far. The age of the outburst is 5.9 × 107 yr, its energy ~3 × 1061 ergs, and its mean power ~1.6 × 1046 …