779 research outputs found
Electrochemical Reactivation of AISI 409 Ferritic Stainless Steel Sheet Welded by Laser Process with application in aeronautical
The susceptibility to sensitization in 409 ferritic stainless steel (FSS) weldments was studied, by means of double loop electrochemical potentiokinetic reactivation test (DL-EPR). After the electrochemical test, the microstructure was analyzed by scanning electron microscopy (SEM) and the presence of elements with dispersive energy of X-rays (EDS), with the X-ray diffraction (XRD) technique they were identified present phases in different welds. Microhardness profiles were employed to evaluate the mechanical properties. With the aim of analyze the effect on the degree of sensitization to welding processes and the base material, a methodological analysis of gas metal arc welding GMAW, gas tungsten arc welding GTAW and LASER welding process was performed. The LASER process generated the highest ratio between the reactivation (Ir) and activation (Ia) current, despite it caused less microstructural change. The higher ratio Ir/Ia is attributed to the lack of penetration in the butt join, showing crevice corrosion.
Keywords: 409 Ferritic stainless steel, DL-EPR, GMAW, GTAW, LASER
Monkeypox, an unattended emerging infection.
El virus de la viruela símica estrechamente relacionado al virus de la viruela humana, es una zoonosis endémica de África occidental y central. En los seres humanos, la infección puede provocar una enfermedad similar a la viruela humana, aunque de menor severidad, pese a ello se asocia a una letalidad reportada variable desde menos del 1% al 11%. La transmisión se produce principalmente a través de gotitas respiratorias o contacto directo con el exudado de lesiones. La transmisión persona a persona está bien descrita, tanto comunitaria como nosocomial. El cuadro clínico se caracteriza por un pródromo de fiebre, al cual se agrega exantema y linfadenopatía. Dentro de las complicaciones se pueden incluir neumonía, encefalitis y queratitis. No existe un tratamiento aprobado establecido, aunque se incluyen estrategias en base a antivirales y vacunas.Monkeypox virus, closely related to human smallpox virus, is a zoonosis endemic to West and Central Africa. In humans, the infection can cause a disease similar to smallpox, although less severe, despite this it is associated with a variable reported lethality from less than 1% to 11%. Transmission occurs primarily through respiratory droplets or direct contact with exudate from lesions. Person-to-person transmission is well described, both in the community and nosocomial. The clinical picture is characterized by a prodrome of fever, to which is added rash and lymphadenopathy. Complications may include pneumonia, encephalitis, and keratitis. There is no established approved treatment, although strategies based on antivirals and vaccines are included
Benzo-Fused Seven- and Six-Membered Derivatives Linked to Pyrimidines or Purines Induce Apoptosis of Human Metastatic Breast Cancer MCF-7 Cells In Vitro
Analysis Approach of How University Automotive Competitions Help Students to Accelerate their Automotive Engineer Profile
Rapid Prototyping for Evaluating Vehicular Communications
[Abstract] This Thesis details the different elements of a rapid prototyping system able to
implement and evaluate vehicular communications fast, according to the continuously
evolving requirements of the industry. The system is basically composed of a testbed
and a channel emulator, which allow evaluating communication transceivers in realistic
vehicular scenarios.
Two different testbeds are introduced: a generic 2x2 system and a vehicular platform.
The former is used to compare and study space-time block coding (STBC) transmissions
at 2.4 GHz over different indoor channels. The latter makes use of software
transceivers whose performance is evaluated when they work under artificial high-speed
Rayleigh-fading scenarios.
To show the capabilities of both platforms, three software transceivers have been
developed following the specifications for the physical layers of the standards IEEE
802.11p, IEEE 802.11a and IEEE 802.16e (Mobile WiMAX). The present work details
the different elements that make up each transceiver and indicates how to connect them
to the rest of the system to perform evaluation measurements.
Finally, single-antenna and multi-antenna performances are measured thanks to the
design and implementation of three FPGA-based channel emulators that are able to
recreate up to seven different vehicular scenarios that include urban canyons, suburban
areas and highways[Resumo] A presente Tese detalla os elementos necesarios para constituir un sistema basado en
prototipado rápido capaz de levar a cabo e avaliar comunicacións vehiculares. O hardware
do sistema está composto básicamente por unha plataforma de probas (testbed)
e un emulador de canal, os cales permiten avaliar o rendemento de transceptores
inartiamicos recreando diferentes escenarios vehiculares.
Inicialmente, este traballo céntrase na descripción do hardware do sistema, detallando
a construcción e proba dunha plataforma multi-antena e un testebed vehicular.
Estos sistemas permitiron, respectivamente, estudar o comportamento de códigos STBC
(space-time block codes) en interiores e medir o rendemento de tranceptores software
ao traballar a distintas velocidades vehiculares en canais con desvaecemento Rayleigh.
Tres transceptores software foron creados seguindo as especificacións das capas
físicas dos estándares IEEE 802.11p, IEEE 802.11a e IEEE 802.16e (Mobile WiMAX).
Este traballo detalla os diferentes componentes de cada transceptor, indicando cómo
conectalos ao resto do sistema para realizar a avaliacition do seu rendemento. Dita
avaliación realizouse coa axuda de tres emuladores de canal basados en tecnoloxía
FPGA (Field Programmable Gate Array), os cales son capaces de recrear ata sete
escenarios vehiculares distintos, incluindo cañóns urbanos, zonas suburbanas e autopistas.[Resumen] La presente Tesis detalla los elementos necesarios para constituir un sistema basado
en prototipado rtiapido capaz de llevar a cabo y evaluar comunicaciones vehiculares.
El hardware del sistema está compuesto por una plataforma de pruebas (testbed) y
un emulador de canal, los cuales permiten evaluar el rendimiento de transceptores
inaltiambricos recreando diferentes escenarios vehiculares.
Inicialmente, este trabajo se centra en la descripcition del hardware del sistema,
detallando la construccition y prueba de una plataforma multi-antena y un testebed
vehicular. Estos sistemas han permitido, respectivamente, estudiar el comportamiento
de ctiodigos STBC (space-time block codes) en interiores y medir el rendimiento en
canal con desvanecimiento Rayleigh de tranceptores software a distintas velocidades
vehiculares.
Tres transceptores software han sido creados siguiendo las especificaciones de las
capas físicas de los estandares IEEE 802.11p, IEEE 802.11a e IEEE 802.16e (Mobile
WiMAX). Este trabajo detalla los diferentes componentes de cada transceptor,
indicando ctiomo conectarlos al resto del sistema para realizar la evaluacition de su
rendimiento. Dicha evaluacition se realiztio con la ayuda de tres emuladores de canal
basados en FPGAs (Field Programmable Gate Array), los cuales son capaces de recrear
comunicaciones multi-antena en hasta siete escenarios vehiculares distintos, incluyendo
cañones urbanos, zonas suburbanas y autopistas
Digestibility of diets with flour fish silage for the growing of arawana (Osteoglossum bicirrhossum)
ABSTRACT
Objective. The purpose of this research was to evaluate the digestibility of different nutritional and energy components of artificial diets containing flour fishsilage used in growing of arawana fingerlings (O. bicirrhossum). Materials and methods. 240 fingerlings distributed in 12 tanks with 20 fish per experimental unit were handled, in a completely randomized design made up of 4 treatments with three replicates, each with inclusions of 0 (0ESH), 10 (10ESH), 20(20ESH) and 30% flour fish silage (30ESH) of treatments T0, T1, T2 and T3 respectively; fromflour fish silagein order to formulate isoenergetic and isonitrogenous diets in the different treatments to avoid sources of miscalculation of the experimental variables. Results. High digestibility coefficients were observed in treatments T1 (10ESH) and T3 (30ESH). The protein, lipid and energy utilization ratios were greater than 60%, which shows the importance of including flour fish silage as a source of protein to improve the various growth parameters. Significant differences between treatments were found in the increase of length (p≤0.05), showing that the T1 was the best treatment with an average of 1.21±0.29 cm. Conclusions. According to the coefficients of digestibility, length increase and benefit – cost ratio, the best treatment was T1 (10ESH) used to feed arawana (O. bicirrhossum), during the growing period, demonstrating the economic and ecological advantages for utilization of this source of protein in aquaculture.
RESUMEN
Objetivo. Analizar la digestibilidad de los diferentes componentes nutricionales y energéticos en dietas balanceadas con niveles de harina de hidrolizado de vísceras de cachama en el alevinaje de arawana (O. bicirrhossum). Materiales y métodos. Se evaluaron 240 alevinos, distribuidos en 12 acuarios a razón de 1 animal/5 L. Se utilizó un diseño completamente al azar, conformado por cuatro tratamientos con tres réplicas cada uno, con inclusiones de 0 (0ESH), 10 (10ESH), 20 (20ESH) y 30% de extracto seco de hidrolizado de vísceras de cachama (30ESH) para los tratamientos T0, T1, T2 y T3 respectivamente; para evitar fuentes de error en el cálculo de las variables experimentales, se formularon dietas isoenergéticas e isonitrogenadas. Resultados. Se detectaron diferencias estadísticas significativas en el incremento de longitud (p≤0.05), indicando que el T1 (10ESH) es el mejor tratamiento con un promedio de talla de 1.21 ±0.29 cm, además, se obtuvieron coeficientes de digestibilidad superiores al 60% en los tratamientos T1 (10ESH) y T3 (30ESH) en lo referente a proteína, lípidos y Coeficientes de Utilización Energética (CUE); demostrando la importancia de incluir el extracto seco de hidrolizado de vísceras de cachama, en las dietas de los peces para mejorar las distintas variables zootécnicas, teniendo en cuenta la importancia acuariofílica de la especie. Conclusiones. De acuerdo con los coeficientes de digestibilidad, incrementos de longitud y la relación beneficio – costo el mejor tratamiento fue el T1 (10 ESH) en dietas de levante para O. bicirrhossum; demostrando las ventajas económicas y ecológicas de la incorporación de esta materia prima en la alimentación acuícola
Modificación reglamentaria en baloncesto: descripción del juego colectivo de ataque en categoría infantil
The aim of this study was to describe the characteristics of attack collective game of the boys 13-and-under competition. The variables studied were number of attack phases, type of each attack phase, duration of each attack phase, number of passes of each attack phase and number of players of each attack phase. The study sample comprised 1878 attack phases from the all six teams which played the boys 13-and-under regular competition for the season 2011/2012 in Granada (Spain), 72 players (age: M=12.56 years, SD=0.54) participated. This research did by means of observational methodology. The findings of the present study show an improvement in competition, adapting to the characteristics and needs of young players. Some aspects could be improved if it change further some of the values obtained in the variables analyzed.El objetivo del presente estudio fue describir las características del juego colectivo de ataque en categoría infantil masculina respecto al número de fases de ataque, duración de la fase de ataque, tipo de fase de ataque, número de pases por fase de ataque y número de jugadores que participan en cada por fase, tras realizar una serie de modificaciones reglamentarias: reducción del número de jugadores y tamaño del balón y de la distancia de la línea de tiro libre y triple con respecto al aro. La muestra estuvo compuesta por 1878 fases de ataque realizadas por los seis equipos que participaron en la competición regular de la categoría infantil masculina durante la temporada 2011/2012 en la provincia de Granada (España), participando un total de 72 jugadores (edad: M=12.56 años, SD=0.54). El estudio se realizó mediante metodología observacional. Los datos muestran una mejora en la competición, adecuándola a las características y necesidades de los jóvenes jugadores. Algunos aspectos son susceptibles de mejora si se modificasen aún más algunos de los valores obtenidos en las variables analizadas
Preparation and characterization of biodegradable gelatine and starch films embedding cerium oxide nanoparticles stabilized by PLGA micelles for antibiofilm applications
Cerium oxide nanoparticles (CeO2NPs) have been widely investigated for numerous applications due to their redox activity, free radical scavenging property, and biofilm inhibition. Here we describe a new antibiofilm system based on CeO2NPs protected and stabilised by PLGA micelles embedded in two different biodegradable and biocompatible films. CeO2NPs were synthesised following the W/O microemulsion method and subsequently encapsulated in PLGA micelles according to the single emulsion/solvent procedure. All formulations (free NPs, empty micelles and loaded micelles) were incorporated in gelatine and starch films aimed at food packaging use. The chemical and physical characterizations of the NPs and micelles solutions were carried out by Dynamic Light Scattering (DLS), Transmission Electron Microscopy (TEM) and X-ray Photoelectron Spectroscopy (XPS). Blank films and films incorporating micelles and NPs were also characterized by Scanning Electron Microscopy (SEM) and by XPS. Antibacterial experiments were also performed to investigate the system viability for the final use
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