The Structure of Displacement Cascades in Silicon

We have extended the work of Mueller and Guenzer on the simulation of damage cascades in silicon. We considered the effects of modifying the energy cutoff and interparticle interaction that they used. We also examined the effect of finite temperature on channeling and of using an amorphous model for the silicon, rather than a crystalline model. An estimate of the maximum size of heavily damaged regions produced by neutron induced displacement damage cascades was made. The effects of high neutron fluence and of annealing are briefly discussed, as is the likehood of permanent device damage resulting from the displacement damage.     

On-Line Subtraction of the Cardiac Activity from the Esophageal Electromyogram of the Diaphragm

A system is described whereby the integrated electrocardiogram is automatically subtracted from the total integrated electrical activity recorded in the esophagus. By this method, a measure of the electrical activity in the diaphragm is obtained, and the output from the respiratory center can be studied independently of mechanical alterations of chest wall and lungs.     

Probing the dynamics of nanoparticle growth in a flame using synchrotron radiation

Flame synthesis is one of the most versatile and promising technologies for large-scale production of nanoscale materials. Pyrolysis has recently been shown to be a useful route for the production of single-walled nanotubes, quantum dots and a wide variety of nanostructured ceramic oxides for catalysis and electrochemical applications. An understanding of the mechanisms of nanostructural growth in flames has been hampered by a lack of direct observations of particle growth, owing to high temperatures (2,000 K), rapid kinetics (submillisecond scale), dilute growth conditions (10(-6) volume fraction) and optical emission of synthetic flames. Here we report the first successful in situ study of nanoparticle growth in a flame using synchrotron X-ray scattering. The results indicate that simple growth models, first derived for colloidal synthesis, can be used to facilitate our understanding of flame synthesis. Further, the results indicate the feasibility of studies of nanometre-scale aerosols of toxicological and environmental concern.     

A New Digital Echo Canceler for Two-Wire Full-Duplex Data Transmission

A new approach to echo canceling for two-wire fullduplex data transmission is proposed. The canceling signal is directly synthesized from the binary data, using a transversal filter approach, and the usual multiplications are replaced by additions and subtractions, thus allowing efficient operation of a large number of taps as required for the canceling of distant echoes. As a specific application, a system processing one sample per baud is discussed where timing signals at both communicating stations are assumed to be synchronized. A stochastic adjustment gradient-type algorithm is used for both training and adaptive tracking of the canceler. It is shown that convergence does not depend on intersymbol interference, timing phase, carrier phase, or the energy ratio of the local to the received signal, but is a function only of the number of taps. Convergence time is proportional to that number, and the optimum step size for fastest convergence is equal to the reciprocal of the number of taps. The residual fluctuation noise is proportional to that part of the mean-square (MS) error which cannot be reduced by the canceler and is a simple function of the product of the tap signal and the step size. The predicted convergence properties are verified by simulation results. Finally, it is shown how such an echo canceler might be used to allow two-wire full-duplex transmission for data rates as high as 4800 bit/s.     

The effect of wall absorption on the Toms effect

The effect of the adsorption of Polymer Molecules to tube walls on the Toms effect has been investigated, whereby strong and weak adsorbing tube materials for like test distances were used.For Reynold's numbers between 70,000 and 100,000, at a pressure difference of approximately 1 atm, the reduction of pressure drop because of a better adsorption is influenced only insignificantly.Since there were reported much more positive results in a publication by Hand and Williams[1], we try to give an interpretation for this discrepancy.     

Alpha-cyano-4-hydroxycinnamic acid affinity sample preparation. A protocol for MALDI-MS peptide analysis in proteomics

We present a new MALD1 sample preparation technique for peptide analysis using the matrix alpha-cyano-4-hydroxy-cinnamic acid (CHCA) and prestructured sample supports. The preparation integrates sample purification, based on the affinity of microcrystalline CHCA for peptides, thereby simplifying the analysis of crude peptide mixtures. Enzymatic digests can thus be prepared directly, without preceding purification. Prepared samples are homogeneous, facilitating automatic spectra acquisition. This method allows preparation of large numbers of samples with little effort and without the need for automation. These features make the described preparation suitable for cost-efficient high-throughput protein identification. Performance of the sample preparation is demonstrated with in situ proteolytic digests of human brain proteins separated by two-dimensional gel electrophoresis.     

TIMING OF REDD CONSTRUCTION BY FALL CHINOOK SALMON IN THE HANFORD REACH OF THE COLUMBIA RIVER

Spawning habits of fall Chinook salmon in the Hanford Reach of the Columbia River have been documented with annual aerial surveys since 1948. We developed a series of models analysing these data, exploring the influence of environmental factors on the timing of redd construction. These models included a logistic regression and a dynamic modelling approach, with combinations of day of year (as a surrogate for environmental cues such as day length), water temperature and discharge as potential explanatory factors. Results of these analyses indicate that day of year was the strongest predictor of the timing of redd construction, but with significant modifying effects of water temperature and discharge. The dynamic modelling approach provides substantial advantages over a traditional logistic regression, including (1) the ability to treat data collected at non‐synchronous time intervals in a consistent fashion and (2) the ability to easily implement complex functions (e.g., threshold responses) relating behaviour to environmental cues. Evaluation of the series as a whole indicates that the median date of redd construction has increased over time, from approximately day 299 in 1950 to day 307 in 2010, as has the temperature on Oct 1 (16.3 °C–18.1 °C). The degree to which these changes are caused by climate change or dam operations is uncertain, however. Copyright © 2013 John Wiley & Sons, Ltd.     

Why seeking help from teammates is a blessing and a curse: A theory of help seeking and individual creativity in team contexts.

Research has not explored the extent to which seeking help from teammates positively relates to a person's own creativity. This question is important to explore as help seeking is commonly enacted in organizations and may come with reciprocation costs that may also diminish creativity. Results based on 291 employees in a single division of a large multinational organization revealed that seeking help predicted creativity and mediated the relationship between intrinsic motivation and creativity. However, help seekers also incurred reciprocation costs in that they tended to give more help to teammates, and giving help to teammates was negatively related to creativity. In general, giving higher levels of help attenuated the positive relationship between help seeking and creativity. We also tested an integrated model to show that help giving moderated the mediated relationship between intrinsic motivation and creativity via help seeking, such that higher levels of help giving attenuated this mediated effect. We discuss theoretical and practical implications recommending additional research regarding the interpersonal creative process in team contexts. (PsycINFO Database Record (c) 2011 APA, all rights reserved)