Influence of configuration effects on multiple burst simulation testing

During the initial phase of a lightning strike attachment on an aircraft, fast current pulses (rise time approximately 100 ns, I(sub max) approximately few kA) were measured, which can create equipment upsets or disturbances. This threat, made of repetitive pulses and usually called 'multiple bursts', can be reproduced at the equipment interfaces assuming that the transfer function of the structure was determined. The normalized waveform H (10 kA - 100 ns rise time) is the reference for one of these pulses. The importance of the coaxial return path termination for the injection of the wave H is emphasized. According to the constitutive materials of the test bed, and the adaptation of the line, the natural oscillations of the structure and the internal coupling mechanisms can be modified. As a conclusion, various test configurations in relation with the nature of the test bed and the characteristics of the generator are detailed, for a more accurate ground simulation of the attachment phase

Developing a thermal confort index for vegetated open space in cities of arid zones

The degree of thermal comfort that people experience in open spaces is one of the determinants for use, especially in areas with extreme climates. It has a wide range of indices in the international literature. However, the study of five indices (THI, PE, TS, PMV and COMFA) regarding subjective responses presented low percentages of predictive successes in the city of study, characterized by an arid climate and intense urban vegetation. Therefore, the aim of this work is to develop a new thermal comfort index to predict more accurately the thermal sensation of the local residents. For this, there were campaigns monitoring of microclimatic parameters and field surveys about the real sensation of the people on a pedestrian street of Mendoza Metropolitan Area (MMA) in both winter and summer. The proposed new model is established through the correlation of environmental variables and individual subjective responses. The multivariate correlation is performed by linear regression. The theory of Akaike´s information is used as criterion to model selection. The new model IZA is a lineal relation of air temperature, relative humidity, wind speed and solar radiation, generally all available weather variables. We found a high correlation between subjective responses and the new model. Besides the Pearson coefficient which gives the new index is higher than other traditional indices evaluated. The percentage of success of the new index exceeds 85%, demonstrating the effectiveness of the proposed model. In conclusion, the use of IZA as a predictor of thermal comfort will allow a fair assessment of the effect of design and composition of space on your comfort conditions, without the need to carry out thermal perception surveys. This will facilitate the evaluation and decision-making regarding the thermal rehabilitation of open spaces.Fil: Ruiz, María Angélica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; ArgentinaFil: Correa Cantaloube, Erica Norma. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; Argentin

Design guidelines to reduce urban temperatures in regions with high solar productivity: Morphological and materials parameters

El estudio aquí expuesto examinó el potencial de las características del perfil urbano -morfología y materialidad- para disminuir las temperaturas urbanas. El objetivo consistió en identificar pautas de diseño y rehabilitación urbana, que permitan densificar áreas residenciales de la ciudad de Mendoza, Argentina. Para ello fueron simulados 32 escenarios con el programa ENVI-met 3.1, en los cuales se combinó distintos niveles de reflectancia solar (albedo) de los materiales que conforman las envolventes, diversas morfologías de perfil urbano, y presencia y ausencia de forestación dentro del canal vial, variando su orientación E-O y N-S. A partir de los resultados obtenidos por las simulaciones, se infiere que aquellos canales viales que presentan un comportamiento térmico más eficiente, están vegetados, y, morfológicamente, su perfil urbano es continuo sobre la línea municipal. En cuanto a la materialidad de sus envolventes, presentan niveles de albedo altos (0.7) en techos y pavimentos, y niveles de albedo bajo (0.3) en fachadas.This study examined the numerical modeling performance of morphological and materials alternatives for reducing urban temperatures. The aim was to identify design and urban regeneration guidelines that enable the densification of residential areas in the city of Mendoza, Argentina. To this end, using ENVI-met 3.1 software 32, scenarios were simulated that combined: different levels of solar reflectance (albedo) of building envelope materials, different urban profile morphologies, the presence or absence of forestation in urban canyons, and E-W/N-S variation in orientation. From the simulation results it can be inferred that there is more efficient thermal performance in the vegetated scenarios that morphologically have a continuous urban profile above the municipal building line. Regarding envelope materiality, there are high albedo levels (0.7) on roofs and pavements, and low albedo levels (0.3) on façades.Fil: Alchapar, Noelia Liliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ambiente, Hábitat y Energía; ArgentinaFil: Correa Cantaloube, Erica Norma. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ambiente, Hábitat y Energía; Argentin

Mathematical models to assessment the energy performance of textured cladding for facades

The temperature increase of a city in relation to its peripheral areas leads to the formation of an Urban Heat Island. Working on the opto-thermal properties of the building envelope is a viable mitigation strategy to reduce the temperatures of a city. Having quantitative data on energy performance allows the development of precise evaluations and the selection of the most efficient data in relation to energy consumption. The degree of efficiency of a material is calculated with an indicator called Solar Reflectance Index (SRI). Since opto-thermal properties change over time, the standard recommends obtaining the SRI level of both new and three-year-aged material (SRI3). In the present work, 80 facade claddings were evaluated to: (a) determine which qualitative variables significantly influence the SRI3 of the claddings; (b) obtain an equation that calculates the SRI3 without the need to monitor the large number of variables used for its calculation. For this, the following statistical methods were used: Multifactorial ANOVA and linear regression model. In this correlational analysis, color, composition and texture were selected as independent variables. The research showed that color is the variable that significantly influences SRI3 in all the evaluated claddings. By means of the equation obtained with the regression model, the SRI3 index was predicted reaching 95% IC. These results significantly save time and simplify the process of obtaining data since it is not necessary to monitor numerous input variables to calculate the indicator.Fil: Alchapar, Noelia Liliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Cientifícas y Tecnológicas; ArgentinaFil: Correa Cantaloube, Erica Norma. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Cientifícas y Tecnológicas; Argentin

All-integrated universal RF photonic spectral shaper

We demonstrate a microwave photonic spectral shaper in a silicon chip enabling distinct phase and amplitude modulation transformation. We show unprecedented RF filtering through monolithic integration of the spectral shaper with tunable ring resonators

Condiciones térmicas y beneficios ambientales de distintas configuraciones de plazas urbanas en zonas áridas

El presente trabajo evalúa las consecuencias de las decisiones de diseño implementadas en las plazas de Mendoza en las últimas décadas y su influencia sobre el comportamiento térmico del espacio. Dentro de cada plaza se han evaluado distintas estructuras de verde y sellado (prado, bosque, centro sellado). Los espacios fueron monitoreados durante el verano 2012-2013.Los resultados muestran que el comportamiento térmico de las estructuras evaluadas depende en gran medida de su condición de acceso al sol y su visión de bóveda celeste. Durante el día (periodo del calentamiento) la estructura más eficiente es la que bloquea la radiación solar mejorando la habitabilidad del espacio. En torno a la noche (periodo de enfriamiento) la estructura más eficiente es la que posee mayor apertura de bóveda celeste y predomina la condición verde de su ámbito. Finalmente desde el punto de vista térmico el patrón de diseño actual debilita los beneficios ambientales de las plazas insertas en ciudades de zonas áridas.This paper evaluates the consequences of design trends that have suffered the Mendoza city’s squares in recent decades and the influence of these design decisions on its thermal behavior. Within each square were evaluated different structures green and sealed (meadow, forest, center sealing). The spaces were monitored during summer 2012-2013. The results show the thermal behavior of the evaluated structures depends largely on his condition access to the sun and its view of sky. During the day (heating period) the structure that blocks solar radiation is the most efficient and improves habitability of the space. Around the night (cooling period) the more open structure, in which green areas are predominant, results the most efficient one. Finally, is observed that current design pattern weakens the environmental benefits of the squares inserted in arid cities.Fil: Stocco, Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Conicet - Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; ArgentinaFil: Canton, Maria Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Conicet - Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; ArgentinaFil: Correa Cantaloube, Erica Norma. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Conicet - Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; Argentin

Solar reflectance index of pedestrian pavements and their response to aging

Due to the impact of the optical characteristics of the materials composing the urban envelopes on the energy balance of cities, their categorization according to their ability to decrease urban temperatures is an indispensable tool for sustainable development. This work presents the evaluation results of the thermal performance of the different pedestrian pavements available in the region, so as to classify them according to the Solar Reflectance Index (SRI). The study was carried out during a 2-year period, involving the analysis of the behaviour of 28 pavements in widely used compositions, shapes and colours. Additionally, the aging effect of the material was quantified over the SRI. The results show that 74% of pavements diminished their initial ability for decreasing temperatures, while 50% of the dark material, with initial negative performances, improved their thermal behavior.Fil: Alchapar, Noelia Liliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; ArgentinaFil: Correa Cantaloube, Erica Norma. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; ArgentinaFil: Canton, Maria Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; Argentin

Evaluation of summer thermal conditions and the environmental efficiency of different urban square designs in Mendoza, Argentina

El objetivo de este trabajo es evaluar las consecuencias de las decisiones de diseño sobre el comportamiento térmico y la eficiencia ambiental de las plazas de la ciudad de Mendoza. A tal fin se seleccionaron tres casos de estudio, donde se evaluó el comportamiento de distintas estructuras presentes en las plazas. Para ello se desarrollaron mediciones de temperatura del aire mediante sensores fijos, durante un periodo de 40 días en la estación verano de 2012, los sensores fueron ubicados en las diferentes estructuras (bosque, prado y centro) de la plaza y en su entorno urbano, siguiendo un eje en sentido norte-sur. Además se determinó el valor del factor de visión de cielo (SVF) y la digitalización hemisférica de la trayectoria solar para todos los puntos evaluados. Los resultados ponen de manifiesto la necesidad de reflexionar y revisar las estructuras de plazas existentes, en cuanto a sus esquemas de diseño, dado que el esquema tradicional que plantea una distribución de espacios en forma simétrica, parece no ser el que combina en forma más eficiente las distintas variables involucradas en el comportamiento térmico de la plaza: materialidad, distribución de la vegetación y exposición solar. Además se observa que a menor densidad edilicia del entorno urbano en el cual se inserta la plaza, sus condiciones térmicas y su eficiencia ambiental pueden mejorarse, casi con independencia de otros factores, mediante un diseño apropiado del espacio.The aim of this study is to assess the impact of design decisions on the thermal performance and environmental efficiency of the squares in Mendoza's city. Three case studies were selected to evaluate the performance of different structures on the squares. Air temperature measurements were registered by fixed sensors for a 40 days period in the warm season of 2012. The sensors were placed in different structures (forest, meadow and centre) of the square and its urban environment, along an axis oriented from north to south. Also, the value of the sky view factor (SVF) was estimated and it was digitized the hemispheric solar path for all points evaluated. The results highlight the need to reexamine the structures of existing spaces from the point of view of their design schemes. The traditional square of symmetrically distribution does not seem to combine, in an efficient way, the different variables involved in its thermal behavior: materiality, distribution of the vegetation and sun exposure. It was also observed that thermal and environmental efficiency can be improved, independently of other factors, with an appropriate space design when the square is placed in an urban environment characterized by a low building density.Fil: Stocco, Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; ArgentinaFil: Canton, Maria Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; ArgentinaFil: Correa Cantaloube, Erica Norma. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; Argentin