Anisotropic renormalized fluctuations in the microwave resistivity in YBCO

We discuss the excess conductivity above Tc due to renormalized order-parameter fluctuations in YBCO at microwave frequencies. We calculate the effects of the uniaxial anisotropy on the renormalized fluctuations in the Hartree approximation, extending the isotropic theory developed by Dorsey [Phys. Rev. B 43, 7575 (1991)]. Measurements of the real part of the microwave resistivity at 24 and 48 GHz and of the dc resistivity are performed on different YBCO films. The onset of the superconducting transition and the deviation from the linear temperature behavior above Tc can be fully accounted for by the extended theory. According to the theoretical calculation here presented, a departure from gaussian toward renormalized fluctuations is observed. Very consistent values of the fundamental parameters (critical temperature, coherence lenghts, penetration depth) of the superconducting state are obtained.Comment: RevTex, 8 pages with 5 figures included, to be published in Physical Review

Gate stability of GaN-Based HEMTs with P-Type Gate

status: publishe

La enseñanza del fútbol sala en la formación de futuros profesionales de la Educación Física: la aproximación entre la teoría y la práctica

El trabajo describe una actividad realizada en la asignatura de fútbol sala del curso de formación de profesorado en Educación Física de la Universidade de Caxias do Sul (UCS) en Brasil. Los estudiantes impartieron clases de fútbol sala para niñas con edad entre los 11 y los 14 años en los centros de enseñanza de la ciudad de Caxias do Sul y su región. El objetivo de la actividad fue proporcionar a los futuros profesionales un mayor acercamiento a la realidad con la cual se deberán enfrentar en un futuro muy cercano, produciendo una formación más significativa y relevante. Al final del curso, después de los 18 partidos semanales previstos, más las clases para las chicas, los estudiantes respondieron un pequeño cuestionario adaptado en la escala de Likert sobre la importancia de la experiencia práctica para su formación. Los resultados determinaron que 7% de los alumnos del curso consideraron que la experiencia de enseñanza con las chicas presentó poca importancia para su formación como profesionales de Educación Física. Por otra parte 16% han considerado importante la actividad práctica. 37% dijeron que la experiencia fue bastante importante y 40% han respondido que la actividad fue de fundamental importancia. Ninguno contestó que la actividad fue nada importante. Así, concluimos que la utilización de esa metodología y experiencia didáctica ha permitido la reducción de las discrepancias entre la teoría y práctica existentes en las asignaturas de carácter práctico en los cursos de formación del profesorado

Resistance Status of House Flies (Diptera: Muscidae) from Southeastern Nebraska Beef Cattle Feedlots to Selected Insecticides

The status of resistance to three insecticides (permethrin, stirofos, and methoxychlor), relative to a laboratory-susceptible colony, was evaluated in Þeld populations of house flies, Musca domestica L., collected from two beef cattle feedlots in southeastern Nebraska. Topical application and residual exposure to treated glass surfaces were suitable methods for determining the resistance status of house flies to permethrin, stirofos, or methoxychlor. However, in most cases, residual exposure was more sensitive in resistance detection (i.e., higher resistance ratios). The field populations tested were moderately resistant to permethrin (RR = 4.9-fold and RR = 7.3-fold, for topical application and residual exposure, respectively) and extremely resistant to stirofos and methoxychlor (not accurately quantifiable be cause of low mortality at the highest possible concentrations or doses). Probable explanations for the resistance status of these house fly populations and implications for global feedlot fly management are discussed

Audio Splicing Detection and Localization Based on Acquisition Device Traces

In recent years, the multimedia forensic community has put a great effort in developing solutions to assess the integrity and authenticity of multimedia objects, focusing especially on manipulations applied by means of advanced deep learning techniques. However, in addition to complex forgeries as the deepfakes, very simple yet effective manipulation techniques not involving any use of state-of-the-art editing tools still exist and prove dangerous. This is the case of audio splicing for speech signals, i.e., to concatenate and combine multiple speech segments obtained from different recordings of a person in order to cast a new fake speech. Indeed, by simply adding a few words to an existing speech we can completely alter its meaning. In this work, we address the overlooked problem of detection and localization of audio splicing from different models of acquisition devices. Our goal is to determine whether an audio track under analysis is pristine, or it has been manipulated by splicing one or multiple segments obtained from different device models. Moreover, if a recording is detected as spliced, we identify where the modification has been introduced in the temporal dimension. The proposed method is based on a Convolutional Neural Network (CNN) that extracts model-specific features from the audio recording. After extracting the features, we determine whether there has been a manipulation through a clustering algorithm. Finally, we identify the point where the modification has been introduced through a distance-measuring technique. The proposed method allows to detect and localize multiple splicing points within a recording

Efeito da adição de óleo na dieta de frangos sobre características físicas da ração.

No presente trabalho foi avaliado o efeito de níveis crescentes de adição de óleo de soja em dietas de frangos de corte sobre as características físicas da ração. Os trata mentos foram compostos por cinco níveis de inclusão de óleo:T1 ?1,74%; T2 ?2,87%; T3?4,01%; T4?5,15%; T5?6,28%.Estas dietas foram submetidas à peletização em equipamento CPM. Antes e após a produção foram coletadas cinco amostras por tratamento e analisadas em relação à características físicas. O delineamento experimental foi inteiramente ao acaso com cinco tratamentos e cinco repetições. Os dados foram submetidos à análise de variância e as médias foram comparadas pelo este t-Student, ao nível de 5%. Foram testados contrastes polinomiais e geradas as equações de regressão. Considerando os níveis de óleo como bloco, foram realizadas as comparações entre as rações fareladas e peletizadas. A peletização reduziu 23% na densidade da ração em relação à farelada. A peletização da dieta aumentou a umidade da ração, reduziu a densidade e diminui o ângulo de repouso. A adição de óleo reduziu o comprimento do pelete, reduziu a densidade da ração farelada, peletizada e da unidade do pelete e aumentou o ângulo de repouso tanto das dietas fareladas quanto peletizadas. This study evaluated the effect of increasing soybean oil levels on feed physical characteristics in broiler diets. The treatments consisted of five oil levels; T1 ?1.74 %, T2 ?2.87 %; T3 ?4.01%, T4 ?5.15%; T5 ?6.28 %. These diets were pelletized with CPM equipment. Before and after pelleting five samples per treatment were collected. Samples were cooled and analyzed for hardness and durability of the pellet and the percentage of fines. The experimental design was completely randomized with five treatments and five replicates. Data were submitted to analysis of variance and means were compared by t-Student Test at 5% level. Polynomial contrasts were also tested and generated regression equations. Assuming oil levels as block, it were performed comparisons between mash and pelleted diets. The pelleting reduced 23% in the feed density comparing to mash. Pelleting diets resulted in an increased of feed moisture, density reduction and decrease of angle of repose. The oil inclusion reduced the pellet length , reduced both mash and pelleted feed density, reduced pellet unitdensity and increased the angle of repose of mash and pellet feed

DAS Over Multimode Fibers With Reduced Fading by Coherent Averaging of Spatial Modes

We investigate the performance of distributed acoustic sensing over multi-mode fibers based on heterodyne phase-sensitive optical time-domain reflectometry. We report a mathematical model describing the relation between phase variation and applied strain in the presence of multi-mode propagation that supports the feasibility of distributed acoustic measurements over multi-mode fibers. We also propose a novel coherent averaging method that achieves up to a three-fold reduction of the noise floor compared to state-of-the-art methods