Directional emission of stadium-shaped micro-lasers

The far-field emission of two dimensional (2D) stadium-shaped dielectric cavities is investigated. Micro-lasers with such shape present a highly directional emission. We provide experimental evidence of the dependance of the emission directionality on the shape of the stadium, in good agreement with ray numerical simulations. We develop a simple geometrical optics model which permits to explain analytically main observed features. Wave numerical calculations confirm the results.Comment: 4 pages, 8 figure

Implications of Growing Biofuels Demands on Northeast Livestock Feed Costs

The relationship between complete-feed prices and commodity feedstock prices are estimated to analyze the effect of higher commodity prices on feed costs, with particular attention towards the price effects and substitutability of corn distillers dried grains with solubles (DDGS). Assuming the historical positive correlation between corn and DDGS prices, each $1/ton increase in the price of corn increases per ton feed costs between$0.45 and $0.67 across livestock sectors. A negative price correlation would offset some of the cost increases, but under most scenarios feed costs are expected to be at or above those experienced in 2007.Agricultural Finance,

Étude en microscopie électronique à balayage de l'installation de deux souches de Xanthomonas campestris pv manihotis sur feuilles de vitroplants de manioc

L'installation de 2 souches de Xanthomonas campestris pv manihotis, agressive (XCM17) et non agressive (XCM4), est suivie conjointement par numération et par microscopie électronique à balayage, sur des vitroplants de manioc. Les observations réalisées en microscopie électronique à balayage confirment la dynamique de population des 2 souches et permettent aussi de localiser les bactéries à la surface des tissus. Immédiatement après inoculation, l'aspect et la répartition des bactéries à la surface du limbe sont identiques quelle que soit la souche. Six jours après inoculation, la souche non agressive (XCM4) qui ne se multiplie pas ou peu à la surface du limbe n'entraîne pas d'altération des tissus foliaires. L'observation décèle la présence d'un voile recouvrant les cellules bactériennes. Dans les mêmes conditions, la souche agressive (XCM17) se multiplie rapidement ; on note la présence d'amas bactériens à proximité des stomates et les tissus présentent des altérations importantes. La méthode d'inoculation mise au point sur vitroplants de manioc permet de reproduire les symptômes caractéristiques de la maladie et de retrouver le comportement attendu des variétés utilisées. La culture in vitro fournit un matériel commode pour l'étude par différentes techniques des premières étapes de l'infection

A First Comparison of Millimeter Continuum and Mg II Ultraviolet Line Emission from the Solar Chromosphere

We present joint observations of the Sun by the Atacama Large Millimeter/submillimeter Array (ALMA) and the Interface Region Imaging Spectrograph (IRIS). The observations were made of a solar active region on 2015 December 18 as part of the ALMA science verification effort. A map of the Sun's continuum emission of size $2.4' \times 2.3'$ was obtained by ALMA at a wavelength of 1.25 mm (239 GHz) using mosaicing techniques. A contemporaneous map of size $1.9'\times 2.9'$ was obtained in the Mg II h doublet line at 2803.5\AA\ by IRIS. Both mm/submm$-\lambda$ continuum emission and ultraviolet (UV) line emission are believed to originate from the solar chromosphere and both have the potential to serve as powerful and complementary diagnostics of physical conditions in this poorly understood layer of the solar atmosphere. While a clear correlation between mm-$\lambda$ brightness temperature $T_B$ and the Mg II h line radiation temperature $T_{rad}$ is observed the slope is $<1$, perhaps as a result of the fact that these diagnostics are sensitive to different parts of the chromosphere and/or the Mg II h line source function includes a scattering component. There is a significant offset between the mean $T_B$(1.25 mm) and mean $T_{rad}$(Mg II), the former being $\approx 35\%$ greater than the latter. Partitioning the maps into "sunspot", "quiet regions", and "plage regions" we find that the slope of the scatter plots between the IRIS Mg II h line $T_{rad}$ and the ALMA brightness temperature $T_B$ is 0.4 (sunspot), 0.56 (quiet regions), and 0.66 (plage regions). We suggest that this change may be caused by the regional dependence of the formation heights of the IRIS and ALMA diagnostics, and/or the increased degree of coupling between the UV source function and the local gas temperature in the hotter, denser gas in plage regions.Comment: 8 pages, 2 figure

Silicon-on ceramic process: Silicon sheet growth and device development for the large-area silicon sheet task of the low-cost solar array project

The technical feasibility of producing solar-cell-quality sheet silicon to meet the Department of Energy (DOE) 1986 overall price goal of $0.70/watt was investigated. With the silicon-on-ceramic (SOC) approach, a low-cost ceramic substrate is coated with large-grain polycrystalline silicon by unidirectional solidification of molten silicon. This effort was divided into several areas of investigation in order to most efficiently meet the goals of the program. These areas include: (1) dip-coating; (2) continuous coating designated SCIM-coating, and acronym for Silicon Coating by an Inverted Meniscus (SCIM); (3) material characterization; (4) cell fabrication and evaluation; and (5) theoretical analysis. Both coating approaches were successful in producing thin layers of large grain, solar-cell-quality silicon. The dip-coating approach was initially investigated and considerable effort was given to this technique. The SCIM technique was adopted because of its scale-up potential and its capability to produce more conventiently large areas of SOC

Conidial germination in scon\u3csup\u3ec\u3c/sup\u3e

Conidial germination in scon

Circular dielectric cavity and its deformations

The construction of perturbation series for slightly deformed dielectric circular cavity is discussed in details. The obtained formulae are checked on the example of cut disks. A good agreement is found with direct numerical simulations and far-field experiments.Comment: 17 pages, 12 figure

A novel metric for coronal MHD models

[1] In the interest of quantitatively assessing the capabilities of coronal MHD models, we have developed a metric that compares the structures of the white light corona observed with SOHO LASCO C2 to model predictions. The MAS model is compared to C2 observations from two Carrington rotations during solar cycle 23, CR1913 and CR1984, which were near the minimum and maximum of solar activity, respectively, for three radial heights, 2.5 R⊙, 3.0 R⊙, and 4.5 R⊙. In addition to simulated polarization brightness images, we create a synthetic image based on the field topology along the line of sight in the model. This open-closed brightness is also compared to LASCO C2 after renormalization. In general, the model\u27s magnetic structure is a closer match to observed coronal structures than the model\u27s density structure. This is expected from the simplified energy equations used in current global corona MHD models

Low level of virological failure and drug resistance among patients receiving antiretroviral treatment under programme conditions in Maputo, Mozambique

Mexico AIDS Conference 200

Does the Name Matter? Developing Brands for Patented Fruit Varieties

WP 2011-16 August 2011JEL Classification Codes: M37; Q13Brands have largely been absent for fresh produce products; however, apples are one notable exception whereby varieties partially take the place of brands. Studying the role of brands in this market is particularly interesting given the introduction of several patented or socalled managed apple varieties. We develop an experiment to examine consumer response to a suite of apple varieties; treatments employ different branding strategies using different names for a new managed variety included in the experiment. Results suggest that the name does influence consumer valuation of the new variety and existing managed varieties, but has little impact on markets for traditional apple varieties