Effect of Diethylenetriamine and Triethylamine sensitization on the critical diameter of Nitromethane

In this work, the critical diameter for detonation was measured for Nitromethane (NM) sensitized with two different amines: Diethylenetriamine (DETA) and Triethylamine (TEA). The critical diameter in glass and polyvinylchloride tubes is found to decrease rapidly as the amount of sensitizer is increased, then increase past a critical amount of sensitizer. Thus the critical diameter reaches a minimum at a critical concentration of sensitizer. It was also found that the critical diameter is lower with DETA than with TEA

Impacts of Fire Emissions and Transport Pathways on the Interannual Variation of CO In the Tropical Upper Troposphere

This study investigates the impacts of fire emission, convection, various climate conditions and transport pathways on the interannual variation of carbon monoxide (CO) in the tropical upper troposphere (UT), by evaluating the field correlation between these fields using multi-satellite observations and principle component analysis, and the transport pathway auto-identification method developed in our previous study. The rotated empirical orthogonal function (REOF) and singular value decomposition (SVD) methods are used to identify the dominant modes of CO interannual variation in the tropical UT and to study the coupled relationship between UT CO and its governing factors. Both REOF and SVD results confirm that Indonesia is the most significant land region that affects the interannual variation of CO in the tropical UT, and El Nino-Southern Oscillation (ENSO) is the dominant climate condition that affects the relationships between surface CO emission, convection and UT CO. In addition, our results also show that the impact of El Nino on the anomalous CO pattern in the tropical UT varies strongly, primarily due to different anomalous emission and convection patterns associated with different El Nino events. In contrast, the anomalous CO pattern in the tropical UT during La Nina period appears to be less variable among different events. Transport pathway analysis suggests that the average CO transported by the "local convection" pathway (Delta COlocal) accounts for the differences of UT CO between different ENSO phases over the tropical continents during biomass burning season. Delta COlocal is generally higher over Indonesia-Australia and lower over South America during El Nino years than during La Nina years. The other pathway ("advection within the lower troposphere followed by convective vertical transport") occurs more frequently over the west-central Pacific during El Nino years than during La Nina years, which may account for the UT CO differences over this region between different ENSO phases.NASA Aura Science Team (AST) program NNX09AD85GJackson School of Geosciences at the University of Texas at AustinJet Propulsion Laboratory, California Institute of Technology, under NASAGeological Science

Component-based Segmentation of words from handwritten Arabic text

Efficient preprocessing is very essential for automatic recognition of handwritten documents. In this paper, techniques on segmenting words in handwritten Arabic text are presented. Firstly, connected components (ccs) are extracted, and distances among different components are analyzed. The statistical distribution of this distance is then obtained to determine an optimal threshold for words segmentation. Meanwhile, an improved projection based method is also employed for baseline detection. The proposed method has been successfully tested on IFN/ENIT database consisting of 26459 Arabic words handwritten by 411 different writers, and the results were promising and very encouraging in more accurate detection of the baseline and segmentation of words for further recognition

The financing behavior of Dutch firms

This paper investigates the financing behaviour of Dutch firms by testing whether a firm’s financing decisions are determined by certain factors identified in various theories. Since a firm’s financing decision is reflected in the changes of its leverage, our research focuses on the relationship between a firm’s debt ratio change and the changes in certain factors. The approach used in the paper is the structural equation modeling (SEM) technique. The model identifies various important factors that are related to Dutch firms’ financing decisions. The empirical results provide moderate support for the static trade-off theory, the pecking-order hypothesis, as well as the dynamic capital structure model. However, our data set is insuffi- cient to confirm the static trade-off theory, and our results provide little evidence to back the asymmetric information argument behind the pecking-order hypothesis.

The determinants of Dutch capital structure choice

This paper uses the structural equation modeling (SEM) technique to empirically test the determinants of capital structure choice for Dutch firms. We include major factors identified by capital structure theories and construct proxies for these factors with consideration of specific institutional settings in the Netherlands. We also carefully rescale the observed variables in order to conform with the linear structure of the model and the multivariate normality assumption. Our empirical results shed many important insights on Dutch firms’ financing behavior. In particular, we identified important factors that have so far been ignored in the literature for the Dutch capital structure choice. Furthermore our results provide evidence supporting the “static trade-off" hypothesis. While the “pecking-order" behavior is observed for Dutch firms, our results cast doubt on the rationale of asymmetric information behind the “pecking-order" hypothesis. We also point out that the static cross-section evidence is not sufficient to conclude whether or not the management of Dutch firms is entrenched. Models based on the dynamic behavior of firms’ capital structure choice are called for such tests.

Comment on "Photon energy and carrier density dependence of spin dynamics in bulk CdTe crystal at room temperature"

We comment on the conclusion by Ma et al. [Appl. Phys. Lett. {\bf 94}, 241112 (2009)] that the Elliott-Yafet mechanism is more important than the D'yakonov-Perel' mechanism at high carrier density in intrinsic bulk CdTe at room temperature. We point out that the spin relaxation is solely from the D'yakonov-Perel' mechanism. The observed peak in the density dependence of spin relaxation time is exactly what we predicted in a recent work [Phys. Rev. B {\bf 79}, 125206 (2009)].Comment: 2 page

Effects of topological edge states on the thermoelectric properties of Bi nanoribbons

Using first-principles calculations combined with Boltzmann transport theory, we investigate the effects of topological edge states on the thermoelectric properties of Bi nanoribbons. It is found that there is a competition between the edge and bulk contributions to the Seebeck coefficients. However, the electronic transport of the system is dominated by the edge states because of its much larger electrical conductivity. As a consequence, a room temperature value exceeding 3.0 could be achieved for both p- and n-type systems when the relaxation time ratio between the edge and the bulk states is tuned to be 1000. Our theoretical study suggests that the utilization of topological edge states might be a promising approach to cross the threshold of the industrial application of thermoelectricity