Pollution and Foraging Behavior of Pied Kingfisher Ceryle rudis in Bujumbura Bay of Lake Tanganyika, Burundi: Conservation Implications

Lake Tanganyika is threatened by overfishing, deforestation, climate change and water pollution. Very few studies have investigated the effects of pollution on semi-aquatic communities such as aquatic birds. This study investigates the effects of pollution on the foraging behavior of pied Kingfisher Ceryle rudis in the Bujumbura bay of Lake Tanganyika. We use data on foraging behavior of this bird species collected in 2002 as background and data collected over two periods during which we assessed change in water environmental parameters. The sampling site is located in the littoral zone next to the channel mouths that collect rainfall and wastewater from Bujumbura city. The results show a change in the number of observations of foraging pied kingfishers during the course of the day with a significantly lower number of observations in the morning than in the study carried out in 2002. The most frequent foraging behavior also changed from direct dives in 2002 to repeated hovering before diving in 2016. These changes could be accounted for by pollution as the water parameters data collected during the same time periods reveal an increase in turbidity while dissolved oxygen levels dropped. Increased turbidity may have caused reduction of visibility of these visual predatory birds. Attention should be given to measures toward alleviation of pollution of Lake Tanganyika for the conservation of semi-aquatic communities which are members of this deep and ancient lake ecosystem

LSST optical beam simulator

We describe a camera beam simulator for the LSST which is capable of illuminating a 60mm field at f/1.2 with realistic astronomical scenes, enabling studies of CCD astrometric and photometric performance. The goal is to fully simulate LSST observing, in order to characterize charge transport and other features in the thick fully depleted CCDs and to probe low level systematics under realistic conditions. The automated system simulates the centrally obscured LSST beam and sky scenes, including the spectral shape of the night sky. The doubly telecentric design uses a nearly unit magnification design consisting of a spherical mirror, three BK7 lenses, and one beam-splitter window. To achieve the relatively large field the beam-splitter window is used twice. The motivation for this LSST beam test facility was driven by the need to fully characterize a new generation of thick fully-depleted CCDs, and assess their suitability for the broad range of science which is planned for LSST. Due to the fast beam illumination and the thick silicon design [each pixel is 10 microns wide and over 100 microns deep] at long wavelengths there can be effects of photon transport and charge transport in the high purity silicon. The focal surface covers a field more than sufficient for a 40x40 mm LSST CCD. Delivered optical quality meets design goals, with 50% energy within a 5 micron circle. The tests of CCD performance are briefly described.Comment: 9 pages, 9 figure

Comparative Analysis of Extrusion Processes by Finite Element Analysis

AbstractExtrusion processes are quite extended in the manufacturing of long products for a wide range of industrial applications. There are different approaches of extrusion processes, depending on either the final shape of the product to obtain or the maximum loading capacity of the equipment to be used. This work presents a comparative study of extrusion processes (solid and cup extrusion), considering both direct and indirect forming conditions and showing the most interesting differences between them. The comparison is realized by Finite Element simulation of the processes, using the code DEFORM F2. The material is a low carbon steel (AISI-1010) and the same extrusion ratio and ram displacement are considered in all cases. By comparing the required forces it can be concluded that required loads are higher in cup extrusion processes than in solid extrusion ones. Regarding the friction load, the maximum contribution due to the die-billet contact in cup extrusion is much higher than in the case of solid extrusion. On the contrary, the maximum friction load contribution due to the container wall is much higher in the case of solid extrusion than in cup extrusion

Analysis of Horizontal Axis Wind Turbine Array Optimization

Wind energy is the fastest growing form of renewable energy, with a multitude of possibilities for expansion. This, as well as other forms of renewable energy, will facilitate understanding of the growing concerns regarding global warming by decreasing our dependence on fossil fuels. Wind energy requires wind speeds of at least six miles per hour; therefore, only certain geographical areas are suitable for the use of this technology. The purpose of this experiment was to determine whether the orientation of an array of wind turbines increases or decreases energy production and efficiency. In this study, various arrays consisting of five wind turbines were tested. The total energy output of each array was tested using a wind tunnel from the wind energy lab at Georgia Southern University, INA219 current sensors, custom software written by Matthew Kiernan, and five “Cutting Edge Power” wind turbines. The most efficient array in terms of voltage, power and current was the 2-1-2 array, with average outputs of: voltage at 3.98 V, current at 440.73 mA, and power at 900.92 mW. The efficiency was determined through the power coefficient, which was 32.64%. The next most efficient array was the Left-Right Staggered array, with averages of: voltage at 3.90 V, current at 208.47 mA, and power at 838.08 mW. The efficiency was determined through the power coefficient, which was 32.13%. The Diagonal array was the third most efficient in overall energy output, with averages of: voltage at 3.75 V, current at 200.66 mA, and power at 789.07 mW. The efficiency was determined through the power coefficient, which was 29.54. The least efficient array array for energy output was Single File, with averages of: voltage at 2.79 V, current at 137.69 mA, and power at 451.05 mW. The efficiency was determined through the power coefficient, which was 18.31%. The results demonstrated that the close proximity of turbines negatively affects energy output, as observed through the turbulence that was produced. Possible errors observed were due to turbine models that did not perform as expected as well as the breadboard configuration

Towards Precision LSST Weak-Lensing Measurement - I: Impacts of Atmospheric Turbulence and Optical Aberration

The weak-lensing science of the LSST project drives the need to carefully model and separate the instrumental artifacts from the intrinsic lensing signal. The dominant source of the systematics for all ground based telescopes is the spatial correlation of the PSF modulated by both atmospheric turbulence and optical aberrations. In this paper, we present a full FOV simulation of the LSST images by modeling both the atmosphere and the telescope optics with the most current data for the telescope specifications and the environment. To simulate the effects of atmospheric turbulence, we generated six-layer phase screens with the parameters estimated from the on-site measurements. For the optics, we combined the ray-tracing tool ZEMAX and our simulated focal plane data to introduce realistic aberrations and focal plane height fluctuations. Although this expected flatness deviation for LSST is small compared with that of other existing cameras, the fast f-ratio of the LSST optics makes this focal plane flatness variation and the resulting PSF discontinuities across the CCD boundaries significant challenges in our removal of the systematics. We resolve this complication by performing PCA CCD-by-CCD, and interpolating the basis functions using conventional polynomials. We demonstrate that this PSF correction scheme reduces the residual PSF ellipticity correlation below 10^-7 over the cosmologically interesting scale. From a null test using HST/UDF galaxy images without input shear, we verify that the amplitude of the galaxy ellipticity correlation function, after the PSF correction, is consistent with the shot noise set by the finite number of objects. Therefore, we conclude that the current optical design and specification for the accuracy in the focal plane assembly are sufficient to enable the control of the PSF systematics required for weak-lensing science with the LSST.Comment: Accepted to PASP. High-resolution version is available at http://dls.physics.ucdavis.edu/~mkjee/LSST_weak_lensing_simulation.pd

Variables predictors of the set in the defence complex in volleyball

El objetivo de la investigación fue conocer las variables predictoras de la eficacia de colocación en el complejo de defensa (KII), en ambos géneros, en categorías de formación. La muestra del estudio estuvo compuesta por 2.404 acciones de juego, 1.104 en género masculino y 1.300 en género femenino, desarrolladas por los 34 equipos participantes en el Campeonato de España Under 16. La variable dependiente fue la eficacia de colocación. Las variables independientes se agruparon en: variables de defensa, de colocación en KII y de bloqueo. Los resultados determinaron que, en ambos géneros, la eficacia de defensa, la técnica de colocación y la participación en bloqueo predecían la eficacia de la colocación; en género masculino, zona de defensa y tiempo de colocación; ninguna variable fue predictora únicamente en género femenino. Esta información puede ser relevante para el desarrollo del proceso de entrenamiento en voleibolThe objective of the research was to analyse the variables predictors of the setting efficacy in the defence complex (KII), in youth athlete, in both genders. The study sample was comprised of 2404 game actions, 1104 in the male gender and 1300 in the female gender. The actions were carried out by the 34 teams that participated in the Spanish Under-16 Championship. The dependant variable was the setting efficacy. The results determined that, in both genders, the dig efficacy, setting technique and the participation in block predicted the setting efficacy; in male gender, the defence zone and tempo of set; no predictor variables were exclusive to the female gender. This information may be relevant when developing training processes in volleyballEste estudio se ha realizado gracias a la aportación de la Consejería de Economía e Infraestructuras de la Junta de Extremadura a través del Fondo Europeo de Desarrollo Regiona

Photometry and spectroscopy of faint candidate spectrophotometric standard DA white dwarfs

We present precise photometry and spectroscopy for 23 candidate spectrophotometric standard white dwarfs. The selected stars are distributed in the Northern hemisphere and around the celestial equators and are all fainter than r ~ 16.5 mag. This network of stars, when established as standards, together with the three Hubble Space Telescope primary CALSPEC white dwarfs, will provide a set of spectrophotometric standards to directly calibrate data products to better than 1%. These new faint standard white dwarfs will have enough signal-to-noise ratio in future deep photometric surveys and facilities to be measured accurately while still avoiding saturation in such surveys. They will also fall within the dynamic range of large telescopes and their instruments for the foreseeable future. This paper discusses the provenance of the observational data for our candidate standard stars. The comparison with models, reconciliation with reddening, and the consequent derivation of the full spectral energy density distributions for each of them is reserved for a subsequent paper.Comment: 31 pages, 17 figures, 10 tables, ApJ in press (accepted on December 23rd, 2018

Participation and Influence of the libero in recepcion and defence, in volleyball U-19

El objetivo fue conocer la participación e influencia líbero en fase de ataque y defensa, en etapas de formación. La muestra fueron 6948 acciones de juego, realizadas por los jugadores de los 21 equipos del Campeonato de España Juvenil masculino. Las variables fueron: función del receptor/defensor, zona de recepción/defensa en profundidad y lateralidad, eficacia de recepción/defensa, zona donde se realiza colocación en recepción/defensa, zona hacia donde se realiza la colocación en recepción/defensa, tiempo de ataque/contraataque y eficacia de ataque/contraataque. En recepción, existió asociación significativa entre función del receptor y zona de recepción en profundidad-lateralidad, y zona donde se realiza la colocación. En defensa, existió asociación significativa entre función del defensor y zona de defensa en profundidad-lateralidad, eficacia de defensa, zona donde se realiza la colocación, zona hacia donde se realiza la colocación y tiempo de contraataque. La influencia del líbero, en estas etapas, se manifiesta más en defensa que en recepciónThe aim was to know the participation and influence of the libero in side-out phase and counter-attack, in young athletes. The sample was 6948 game actions, carried out by the players of the 21 teams that participate in the Under-19 Spanish Championship. The variables were: player that intervened in reception/dig, depth and laterality reception/dig zone, reception/dig efficacy, setting zone in reception/dig, set´s area in reception/dig, tempo of attack/counterattack and attack/counterattack efficacy. In reception, showed significant association between player that intervened in reception, depth-laterality reception zone and the setting zone. In defense, showed significant association between the player that intervened in dig and the depth-laterality dig zone, dig efficacy, setting zone, set´s area and tempo of counterattack. The influence of the participation of the libero, in young athletes, appeared more often in defense than in the receptio

RF-Based Location Using Interpolation Functions to Reduce Fingerprint Mapping

Indoor RF-based localization using fingerprint mapping requires an initial training step, which represents a time consuming process. This location methodology needs a database conformed with RSSI (Radio Signal Strength Indicator) measures from the communication transceivers taken at specific locations within the localization area. But, the real world localization environment is dynamic and it is necessary to rebuild the fingerprint database when some environmental changes are made. This paper explores the use of different interpolation functions to complete the fingerprint mapping needed to achieve the sought accuracy, thereby reducing the effort in the training step. Also, different distributions of test maps and reference points have been evaluated, showing the validity of this proposal and necessary trade-offs. Results reported show that the same or similar localization accuracy can be achieved even when only 50% of the initial fingerprint reference points are taken

Rhizoctonia sp. binucleada asociada a raíces micorrizadas por Tuber melanosporum ITTAD: póster

PublishedTrabajo financiado por Gobierno Nacional de la República del Ecuador, a través del Programa de Becas Convocatoria Abierta 2012 de la Secretaria de Educación Superior, Ciencia, Tecnología e Innovación SENESCY