Failure analysis of a steel motorcycle kickstand

Copyright @ 2009 Springer US.A fractured steel motorcycle kickstand was metallurgically investigated using a range of failure analysis tools [visual examination, energy dispersive X-ray (EDX) analysis, electron microprobe analysis (EPMA), scanning electron microscopy (SEM), fractography, optical microscopy, hardness testing and non-destructive testing (NDT)]. The steel kickstand’s composition, its microstructure, electron fractographs, and mechanical test results have been critically interpreted. Some evidence of wear damage, in the failed kickstand, was observed. The microstructural and fractographic analyses showed pre-existing micro-cracks which were believed to have grown to result in ductile failure followed by acceleration of corrosion. Recommendations have been made to avoid the failure of the motorcycle kickstand

Efficient synthesis of plate-like crystalline hydrated tungsten trioxide thin films with highly improved electrochromic performance

Cataloged from PDF version of article.Plate-like hydrated tungsten trioxide (3WO(3)center dot H(2)O) films were grown on a fluorine doped tin oxide (FTO) coated transparent conductive substrate via an efficient, facile and template-free hydrothermal method. The film exhibited a fast coloration/bleaching response (t(c90%) = 4.3 s and t(b90%) = 1.4 s) and a high coloration efficiency (112.7 cm(2) C(-1)), which were probably due to a large surface area

All-optical mapping of barrel cortex circuits based on simultaneous voltage-sensitive dye imaging and channelrhodopsin-mediated photostimulation

© The Author(s), 2015. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Neurophotonics 2 (2015): 021013, doi:10.1117/1.NPh.2.2.021013.We describe an experimental approach that uses light to both control and detect neuronal activity in mouse barrel cortex slices: blue light patterned by a digital micromirror array system allowed us to photostimulate specific layers and columns, while a red-shifted voltage-sensitive dye was used to map out large-scale circuit activity. We demonstrate that such all-optical mapping can interrogate various circuits in somatosensory cortex by sequentially activating different layers and columns. Further, mapping in slices from whisker-deprived mice demonstrated that chronic sensory deprivation did not significantly alter feedforward inhibition driven by layer 5 pyramidal neurons. Further development of voltage-sensitive optical probes should allow this all-optical mapping approach to become an important and high-throughput tool for mapping circuit interactions in the brain.This work was supported by the World Class Institute (WCI) program of the National Research Foundation of Korea (NRF) funded by Ministry of Education, Science and Technology of Korea (MEST) (NRF) Grant No. WCI 2009-003 and by the Competitive Research Programme (CRP) of NRF (Singapore) Grant No. NRF 2008 NRF-CRP 002-082

Effects of Nonlinear Dispersion Relations on Non-Gaussianities

We investigate the effect of non-linear dispersion relations on the bispectrum. In particular, we study the case were the modified relations do not violate the WKB condition at early times, focusing on a particular example which is exactly solvable: the Jacobson-Corley dispersion relation with quartic correction with positive coefficient to the squared linear relation. We find that the corrections to the standard result for the bispectrum are suppressed by a factor $\frac{H^2}{p_c^2}$ where $p_c$ is the scale where the modification to the dispersion relation becomes relevant. The modification is {\it mildly} configuration-dependent and equilateral configurations are more suppressed with respect to the local ones, by a factor of one percent. There is no configuration leading to enhancements. We then analyze the results in the framework of particle creation using the approximate gluing method of Brandenberger and Martin, which relates more directly to the modeling of the trans-Planckian physics via modifications of the vacuum at a certain cutoff scale. We show that the gluing method overestimates the leading order correction to the spectrum and bispectrum by one and two orders, respectively, in $\frac{H}{p_c}$. We discuss the various approximation and conclude that for dispersion relations not violating WKB at early times the particle creation is small and does not lead to enhanced contributions to the bispectrum. We also show that in many cases enhancements do not occur when modeling the trans-Planckian physics via modifications of the vacuum at a certain cutoff scale. Most notably they are only of order O(1) when the Bogolyubov coefficients accounting for particle creation are determined by the Wronskian condition and the minimization of the uncertainty between the field and its conjugate momentum.Comment: v1: 11 pages, 2 figures; v2: references update

Efficient synthesis of plate-like crystalline hydrated tungsten trioxide thin films with highly improved electrochromic performance

Plate-like hydrated tungsten trioxide (3WO3·H 2O) films were grown on a fluorine doped tin oxide (FTO) coated transparent conductive substrate via an efficient, facile and template-free hydrothermal method. The film exhibited a fast coloration/bleaching response (tc90% = 4.3 s and tb90% = 1.4 s) and a high coloration efficiency (112.7 cm2 C-1), which were probably due to a large surface area

Excited-state optically detected magnetic resonance of spin defects in hexagonal boron nitride

Negatively charged boron vacancy (VB-) centers in hexagonal boron nitride (hBN) are promising spin defects in a van der Waals crystal. Understanding the spin properties of the excited state (ES) is critical for realizing dynamic nuclear polarization. Here, we report zero-field splitting in the ES of DES = 2160 MHz and an optically detected magnetic resonance (ODMR) contrast of 12% at cryogenic temperature. The ES has a g-factor similar to the ground state. The ES photodynamics is further elucidated by measuring the level anti-crossing of the VB- defects under varying external magnetic fields. In contrast to nitrogen vacancy (NV-) centers in diamond, the emission change caused by excited-state level anti-crossing (ESLAC) is more prominent at cryo-temperature than at room temperature. Our results provide important information for utilizing the spin defects of hBN in quantum technology

Thermoplastic Green Machining for Textured Dielectric Substrate for Broadband Miniature Antenna

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65902/1/j.1551-2916.2005.00089.x.pd

Cosmological perturbations in a healthy extension of Horava gravity

In Horava's theory of gravity, Lorentz symmetry is broken in exchange for renormalizability, but the original theory has been argued to be plagued with problems associated with a new scalar mode stemming from the very breaking of Lorentz symmetry. Recently, Blas, Pujolas, and Sibiryakov have proposed a healthy extension of Horava gravity, in which the behavior of the scalar mode is improved. In this paper, we study scalar modes of cosmological perturbations in extended Horava gravity. The evolution of metric and density perturbations is addressed analytically and numerically. It is shown that for vanishing non-adiabatic pressure of matter the large scale evolution of cosmological perturbations converges to that described by a single constant, $\zeta$, which is an analog of a curvature perturbation on the uniform-density slicing commonly used in usual gravitational theories. The subsequent evolution is thus determined completely by the value of $\zeta$.Comment: 10 pages, 4 figures; v2: published versio

The impact of environmental, social, and governance disclosure on firm value: The role of CEO power

Using a large cross-sectional dataset comprising of FTSE 350 listed firms, this study investigates whether superior environmental, social and corporate governance (ESG) disclosure affects firm value. We find a positive association between ESG disclosure level and firm value, suggesting that improved transparency and accountability and enhanced stakeholder trust play a role in boosting firm value. We also report that higher CEO power enhances the ESG disclosure effect on firm value, indicating that stakeholders associate ESG disclosure from firms with higher CEO power with greater commitment to ESG practice. This evidence is strong and consistent for three different measures of ESG-related disclosure: the ESG, environmental and social disclosure scores. The results are robust to the use of an instrumental variable approach, and the Heckman two-stage estimation procedure

Saving tropical forests by knowing what we consume

Oil palm agriculture threatens tropical forests and biodiversity. Previous studies focused on finding ways to reduce the impacts of oil palm on biodiversity and the environment. However, the actual uptake of sustainable practices depends in part on economic demand. We undertook the first investigation on consumer attitudes and willingness‐to‐pay (WTP) for deforestation‐free sustainable palm oil. In a sample of 251 consumers in Singapore, we found little consumer bias against palm oil per se. However, consumers had strong negative opinions toward products that cause deforestation. On average, consumers stated a WTP of 8.2–9.9% more for common palm oil‐containing products that are deforestation‐free. Given the current premium for segregated certified sustainable palm oil (CSPO; 1.5–5%), there is an incentive for manufacturers to use CSPO. Educational campaigns by environmental organizations and prominent advertising of CSPO usage through sustainability labels can potentially improve the economic demand for sustainable practices in oil palm agriculture.Xingli Giam, Letchumi Mani, Lian Pin Koh and Hugh T.W. Ta