Plasmonic Meta-Surface for Efficient Ultra-Short Pulse Laser-Driven Particle Acceleration

A laser-driven particle accelerator based on plasmonic nano-antennas is proposed and analyzed. The concept utilizes the enhancement and localization of the electric field by nano-antennas to maximize the acceleration gradient and to overcome potential metallic losses. The structure is optimized for accelerating relativistic particles using a femto-second laser source operating at 800nm, and is shown to support the bandwidth of ultra-short laser pulses (up to 16fsec) while providing a high acceleration gradient potentially reaching 11.6GV/m.Comment: 7 pages, 5 figure

Cost of generic clinical mastitis in dairy cows

In this thesis a framework for estimating production losses and monetary costs of generic clinical mastitis (CM) was developed and possible applications were demonstrated. Milk Losses were estimated from 5 large, high producing, dairy herds that used automatic recording of daily milk yields by using mixed models, with a random herd effect and an autoregressive covariance structure to account for repeated measurements. Generalized mixed models, with a random herd effect, were used to quantify the effect of CM on mortality and culling. Generalized mixed models, with a random herd effect, were used to estimate the conditional risks for the first 3 CM occurrences. A specially structured optimization and simulation model based on multilevel hierarchical Markov process that included a detailed representation of repeated episodes of CM was used to study the effects of various factors on the cost of CM. The average cost of CM in our study herds was $179. In the basic scenario 92$3-$403), and moderately on exogenous factors. The costs of following sub optimal replacement policies were evaluated, such as a decision to treat all cows with CM or replacing all cows after their 3rd CM case. The cost-benefit of applying two fictitious vaccinations were calculated. Comparing expected net present values obtained from the model for cows with similar traits but differing in CM state and pregnancy status can assist the farmer in making quantitative economic CM treatment decisions. Current information technology as online individual cow milk recording systems and detailed herd management programs enable individual farm estimations in a growing number of dairy farms. The developed dynamic optimization and simulation model with its user interface enables gaining insight into disease costs under farm specific conditions. Such a model can be used by dairy farmers, bovine practitioners, or extension experts to assist in disease management decisions and thus improve the profitability of the enterprise

Altitude effects on heat transfer processes in aircraft electronic equipment cooling

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1989.Includes bibliographical references (leaves 113-115).by Doron Bar-Shalom.M.S

The Effect of Chlorides on the Performance of DME/Mg[B(HFIP)4_4]2_2 Solutions for Rechargeable Mg Batteries

One of the major issues in developing electrolyte solutions for rechargeable magnesium batteries is understanding the positive effect of chloride anions on Mg deposition-dissolution processes on the anode side, as well as intercalation-deintercalation of Mg$^{2+}$ ions on the cathode side. Our previous results suggested that Cl$^−$ ions are adsorbed on the surface of Mg anodes and Chevrel phase Mg$_x$Mo$_6$S$_8$ cathodes. This creates a surface add-layer that reduces the activation energy for the interfacial Mg ions transportation and related charge transfer, as well as promotes the transport of Mg$^{2+}$ from the solution phase to the Mg anode surface and into the cathodes\u27 host materials. Here, this work further examines the effect of adding chlorides to the state-of-the-art Mg[B(HFIP)$_4$]$_2$/DME electrolyte solution, specifically focusing on reversible magnesium deposition, as well as the performance of Mg cells with benchmark Chevrel phase cathodes. It was observed that the presence of chlorides in these solutions facilitates both Mg deposition, and Mg$^{2+}$ ions intercalation, whereby this effect is more pronounced as the purity level of the solution is lowered

Primary Metabolites, Anthocyanins, and Hydrolyzable Tannins in the Pomegranate Fruit

Pomegranate (Punica granatum L.) is an important and interesting fruit tree that is cultivated in many parts of the world. In recent years, along with the increase in its cultivation and consumption there has been a dramatic increase in the scientific interest in its biology, methods of cultivation, adaptation to environmental cues and its health-promoting properties. Quite a large proportion of the various metabolites produced in the pomegranate were determined and their content in the bark, roots, leaves, and fruit was reported. Many reviews on polyphenolic compound content, antioxidant activity and health-promoting compounds were published recently. However, only very few recent reports were dedicated to primary metabolites, despite the fact that much work was done on organic acids, sugars, proteins, lipids, and amino acids of the pomegranate fruit. In this review, a special effort was made to present these recent studies and the review is devoted to primary metabolites. The reported data show high variation in the content of primary metabolites within the pomegranate fruit; therefore the data is presented (whenever possible) according to fruit tissues (peel, arils, and seeds), developmental stages of the fruit, environmental and climatic conditions, and genetic background. Most of the data on pomegranate is based on metabolic content and contains no genetic or molecular analysis except for work done on anthocyanins and hydrolyzable tannins. In those cases, gene assignment and genetic control studies were pointed out in the review. The recent publication of the genome sequences from several pomegranate varieties and transcriptomic data from fruits, flowers, and leaves is expected to facilitate the understanding of genetic control of metabolites in pomegranate

Detectors for the Gamma-Ray Resonant Absorption (GRA) Method of Explosives Detection in Cargo: A Comparative Study

Gamma-Ray Resonant Absorption (GRA) is an automatic-decision radiographic screening technique that combines high radiation penetration with very good sensitivity and specificity to nitrogenous explosives. The method is particularly well-suited to inspection of large, massive objects (since the incident gamma-ray probe is at 9.17 MeV) such as aviation and marine containers, heavy vehicles and railroad cars. Two kinds of gamma-ray detectors have been employed to date in GRA systems: 1) Resonant-response nitrogen-rich liquid scintillators and 2) BGO detectors. This paper analyses and compares the response of these detector-types to the resonant radiation, in terms of single-pixel figures of merit. The latter are sensitive not only to detector response, but also to accelerator-beam quality, via the properties of the nuclear reaction that produces the resonant gamma-rays. Generally, resonant detectors give rise to much higher nitrogen-contrast sensitivity in the radiographic image than their non-resonant detector counterparts and furthermore, do not require proton beams of high energy-resolution. By comparison, the non-resonant detectors have higher gamma-detection efficiency, but their contrast sensitivity is very sensitive to the quality of the accelerator beam. Implications of these detector/accelerator characteristics for eventual GRA field systems are discussed.Comment: 11 page

Noncoding deletions reveal a gene that is critical for intestinal function.

Large-scale genome sequencing is poised to provide a substantial increase in the rate of discovery of disease-associated mutations, but the functional interpretation of such mutations remains challenging. Here we show that deletions of a sequence on human chromosome 16 that we term the intestine-critical region (ICR) cause intractable congenital diarrhoea in infants1,2. Reporter assays in transgenic mice show that the ICR contains a regulatory sequence that activates transcription during the development of the gastrointestinal system. Targeted deletion of the ICR in mice caused symptoms that recapitulated the human condition. Transcriptome analysis revealed that an unannotated open reading frame (Percc1) flanks the regulatory sequence, and the expression of this gene was lost in the developing gut of mice that lacked the ICR. Percc1-knockout mice displayed phenotypes similar to those observed upon ICR deletion in mice and patients, whereas an ICR-driven Percc1 transgene was sufficient to rescue the phenotypes found in mice that lacked the ICR. Together, our results identify a gene that is critical for intestinal function and underscore the need for targeted in vivo studies to interpret the growing number of clinical genetic findings that do not affect known protein-coding genes