Second order statistics of NLOS indoor MIMO channels based on 5.2 GHz measurements

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Settlement behaviour of hybrid asphalt-ballast railway tracks

The use of structural asphalt layers inside ballasted railway tracks is attractive because it can increase track bending stiffness. Therefore, for the first time, this paper investigates the long-term settlement characteristics of asphaltic track in the presence of a subgrade stiffness transition zone. Phased load cyclic compression laboratory tests are performed on a large-scale hybrid asphalt-ballast track, supported by subgrade with varying stiffness. It is found that an asphaltic layer acts as a bridge to shield the subgrade from high stresses. It is also found that the asphalt reduces track settlement, and is particularly effective when subgrade stiffness is low

418 cm-1 Raman scattering from gallium nitride nanowires: Is it a vibration mode of N-rich Ga-N bond configuration?

A Raman-active vibration mode at 418 cm-1 is observed in wurtzite gallium nitride (GaN) nanowires synthesized by different growth methods. In particular, Raman scattering measurements of a number of GaN nanowires systematically prepared by nitriding Β- Ga2 O3 nanowires at different temperatures show an interesting evolution of the mode, revealing that it is most likely the vibration mode of N-rich octahedral Ga- N6 bonds. This idea is further supported by the high-resolution transmission electron microscopic observation. © 2007 American Institute of Physics.published_or_final_versio

Increased risk of suicide in New South Wales men with prostate cancer: Analysis of linked population-wide data

© 2018 Smith et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Background An elevated risk of suicide after a diagnosis of prostate cancer has been reported previously in the USA and Sweden. We aimed to identify whether prostate cancer survivors resident in New South Wales Australia are at higher risk of suicide and if so, who is most at risk. Methods Data were obtained from the New South Wales (NSW) Cancer Registry for all men diagnosed with prostate cancer in NSW during 1997 to 2007. These were linked by the Centre for Health Record Linkage (CHeReL) to Australian Bureau of Statistics Mortality Data to the end of 2007 to determine vital status and cause of death. We compared the number of suicides observed for prostate cancer survivors with the expected number of suicides based on age- and calendar year- specific rates for the NSW Male population using standardised mortality ratios (SMRs). Suicide rate ratios (RR) by disease and patients' characteristics were estimated using multivariable negative binomial regression to determine the most at risk groups. Results During the study period 51,924 NSW men were diagnosed with prostate cancer. Forty nine of these men were subsequently recorded as committing suicide up to 10 years after diagnosis with an SMR of 1.70 (95% CI:1.26±2.25). Twenty six (53%) of these suicides occurred within 12 months after diagnosis. Risk diminished over time since diagnosis (RR in 1±2 years after diagnosis = 0.29, 95% CI: 0.12±0.71, 2±4 years RR = 0.30, 95% CI: 0.14±0.16 and 4+ years RR = 0.26, 95% CI: 0.11±0.60 compared with <1 year since diagnosis). Men with non-localised disease had a higher risk of suicide compared to men with localised disease (RR = 2.68, 95% CI: 1.15±6.23). Men living outside major cities had lower risk of suicide compared to those resident in major cities (rate ratio = 0.42, 95% CI: 0.20±0.87). Single, divorced, widowed or separated men were more likely to commit suicide than married men (RR = 4.18, 95% CI: 2.36±7.42). Conclusion Risk of suicide is higher for NSW men diagnosed with prostate cancer than the general age matched Male population. Vulnerable or lonely men and those with pre-existing depression or suicidal ideation who are diagnosed with prostate cancer should be offered additional psychological support

True nature of an archetypal self-assembly system: Mobile Au-thiolate species on Au(111)

Alkanethiol self-assembled monolayer (SAM) phases on Au(111) have been assumed to involve direct S head group bonding to the substrate. Using x-ray standing wave experiments, we show the thiolate actually bonds to gold adatoms; self-organization in these archetypal SAM systems must therefore be governed by the movement of these Au-S-R moieties on the surface between two distinct local hollow sites on the surface. The results of recent ab initio total energy calculations provide strong support for this description, and a rationale for the implied significant molecular mobility in these systems

Rail trackbed and performance testing of stabilised sub-ballast in normal and high-speed environments

The ability of geogrids to preserve track alignment within a high-speed rail environment at close to critical velocity is somewhat uncertain; testing in a controlled environment can be problematic. This paper presents the results from a new ‘true triaxial’ test apparatus that overcomes some of these problems. In ‘normal’-speed rail environments, geogrids have been used for many years to stabilise and enhance the performance of sub-ballast to maintain both vertical and horizontal alignment and increase the interval between maintenance events. This has been reflected in controlled testing conducted in both the laboratory, in the field and under heavy loading. To look at this issue for high-speed rail and to make comparisons between track alignment preservation in normal and high-speed environments, a new ‘true triaxial’ test apparatus (GeoTT) has been developed at Heriot Watt University that can subject railway sub-ballast to forces in all 6 directions, mimicking the principle stress rotation that has been implicated in track alignment deterioration subjected to high speed train traffic. The use of this apparatus, where the rams are programmed using force-time histories developed from 3D finite element models, allows sub-ballast performance to be evaluated for the fraction of the time and cost that would be necessary for full scale testing. A comparison is made between existing testing results from ‘normal-speed’ testing and the new high speed simulations that indicate the continued potential for geogrids to continue to aid track performance in much more critical environments

Quantum dissipation and broadening mechanisms due to electron-phonon interactions in self-formed InGaN quantum dots

Quantum dissipation and broadening mechanisms in Si-doped InGaN quantum dots are studied via the photoluminescence technique. It is found that the dissipative thermal bath that embeds the quantum dots plays an important role in the photon emission processes. Observed spontaneous emission spectra are modeled with the multimode Brownian oscillator model achieving an excellent agreement between experiment and theory for a wide temperature range. The dimensionless Huang-Rhys factor characterizing the strength of electron-LO-phonon coupling and damping constant accounting for the LO-phonon-bath interaction strength are found to be ∼0.2 and 200 cm-1, respectively, for the InGaN QDs. © 2006 American Institute of Physics.published_or_final_versio

A glutathione s-transferase confers herbicide tolerance in rice

Plant glutathione S-transferases (GSTs) have been a focus of attention due to their role in herbicide detoxification. OsGSTL2 is a glutathione S-transferase, lambda class gene from rice (Oryza sativa L.). Transgenic rice plants over-expressing OsGSTL2 were generated from rice calli by the use of an Agrobacterium transformation system, and were screened by a combination of hygromycin resistance, PCR and Southern blot analysis. In the vegetative tissues of transgenic rice plants, the over-expression of OsGSTL2 not only increased levels of OsGSTL2 transcripts, but also GST and GPX expression, while reduced superoxide. Transgenic rice plants also showed higher tolerance to glyphosate and chlorsulfuron, which often contaminate agricultural fields. The findings demonstrate the detoxification role of OsGSTL2 in the growth and development of rice plants. It should be possible to apply the present results to crops for developing herbicide tolerance and for limiting herbicide contamination in the food chain

Settlement behaviour of hybrid asphalt-ballast railway tracks

The use of structural asphalt layers inside ballasted railway tracks is attractive because it can increase track bending stiffness. Therefore, for the first time, this paper investigates the long-term settlement characteristics of asphaltic track in the presence of a subgrade stiffness transition zone. Phased load cyclic compression laboratory tests are performed on a large-scale hybrid asphalt-ballast track, supported by subgrade with varying stiffness. It is found that an asphaltic layer acts as a bridge to shield the subgrade from high stresses. It is also found that the asphalt reduces track settlement, and is particularly effective when subgrade stiffness is low

True triaxial testing of geogrid for high speed railways

This work describes a series of novel experimental tests to determine the potential of geogrids to confine granular layers within ballasted railway lines operating at speeds close to critical velocity. This is important because at low train speeds, vertical stresses are dominant, but when approaching critical velocity conditions, dynamic horizontal stress levels are magnified. Therefore the majority of previous geogrid investigations have been performed assuming constant horizontal stress levels, thus making them more relevant for lower speed lines. To investigate settlement under high relative train speeds, ballasted railway track samples were subject to combined vertical-horizontal cyclic loading. Three areas were explored: (1) the performance benefit from placing geogrid at the ballast-subballast interface, (2) the performance benefit from placing geogrid at the subballast-subgrade interface, (3) the effect of subgrade stiffness on geogrid performance at the subballast-subgrade interface. Testing was performed using a unique large-scale true triaxial apparatus which had the ability to vary stress levels in three Cartesian directions. Compared to the control conditions, the geogrid offered a settlement improvement of approximately 35% when placed at the ballast-subballast interface, and 10–15% when placed at the subballast-subgrade interface. Regarding subgrade CBR, it was found that the geogrid offered the greatest performance benefits when the subgrade was soft. Therefore it was concluded that for the ballasted rail structures under test, when subject to elevated levels of horizontal stress, geogrids reduced settlements compared to non-geogrid solutions