International audienceReliability of connectors is still a major concern for end users in many ap... more International audienceReliability of connectors is still a major concern for end users in many applications. One way to improve it is to optimize the surface coatings deposited on base substrates. Although gold remains the most widely used contact plating material, many alternative coatings have been developed in the past or recent years. Among these alternatives are silver final coatings and gold flash over palladium-nickel plated alloy. The properties of these two platings have been mainly investigated in symmetrical configurations where male and female contacts have similar deposits. In this work, asymmetrical configurations - where platings on male and female contacts are dissimilar - are studied. Wear behaviour was investigated with friction and fretting tests. The aim was to characterize the role of the various layers on the wear performances of contacts. Contact resistance behaviours were measured and correlated to the wear tracks investigated with various techniques such as ...
30th International Conference on Electrical Contacts - ICEC 2020, Jun 7, 2021
Plating systems of electrical contacts are key technologies for connectors in terms of electrical... more Plating systems of electrical contacts are key technologies for connectors in terms of electrical and mechanical reliability performance. Au/Ni is historically the reference plating system and Au/PdNi/Ni is widely used since 1986. More recently, plating systems like Au/Ag/Ni, Au/NiW, AgPd/Ni and AgSb/Ni were also introduced. Nevertheless, published scientific literature, concerning tribological compatibility of these various plating systems, is limited. This research work is a simplified approach to study compatibility, in terms of durability & wear, between Au/Ni, AuPdNi/Ni, Au/Ag/Ni and AgSb/Ni under different contact pressures or normal forces. Durability and frictional wear testing were performed. Various surface analysis techniques were used to analyze wear tracks and investigate wear mechanisms as well as their impact on contact resistance. Results show that terminal contact pressure range is a key parameter to take into account when mating two different platings. precious metals) and its moderate cost offset all its disadvantages. Silver plated connectors were historically rated for 50 mating/unmating cycles only. A lot of development work followed in the mid 2000's and new silver plating stacks and deposits were developed with pure silver showing much higher hardness and Young moduli. Several alloyed silver processes were also developed with deposits showing relatively very high hardness such as silver-antimony (AgSb) and silver-palladium (AgPd) [3,4]. Researchers developed improved organic or inorganic anti-tarnishing solutions as silver is naturally subject to sulfidation. Improved post-treatments were also developed such as new contact lubricants or low coefficient of friction grafted molecules. The objective was to extend silver usage to electronic connectors where more than 50 mating/unmating cycles are required, as gold and palladium prices have shown to be extremely volatile and unpredictable. We have seen, for example, AgSb plated connectors developed and commercialized, by several connector manufacturers, for Hybrid and Electrical vehicles where several thousands of mating/unmating cycles are required. This was unimaginable initially when considering silver plating. We have also seen gold over hard silver (GCS) plated electronic and power connectors [5,6] commercialized, when gold plated over silver engineering usage was limited, for decades, to special electrical switches [7] applications and special aerospace connectors.
En este trabajo, se realizó la simulación numérica de la respuesta dinámica de un sistema multicu... more En este trabajo, se realizó la simulación numérica de la respuesta dinámica de un sistema multicuerpo utilizando un modelo unidimensional (1D) implementado a través de elementos finitos (EF), para establecer una comparación con su modelo analítico propuesto en ecuaciones diferenciales ordinarias (EDO). El sistema multicuerpo seleccionado es uno de los objetos de estudio de la dinámica de sistemas vehiculares, un vehículo de transporte de carga constituido por cuerpos rígidos y cuerpos elásticos. Se obtuvieron resultados satisfactorios, con errores menores del 2.5% respecto al modelo teórico de referencia que validan el modelo numérico generado por métodos computacionales para el estudio dinámico y la factibilidad de ser empleado para modelar sistemas de esta índole y de mayor complejidad. Tales resultados conducen a afirmar la ventaja que ofrece el modelado numérico utilizando herramientas computacionales para incorporar algunas otras características del sistema multicuerpo que no son consideradas en los modelos analíticos simplificados, como lo es la integración entre el estudio del estado de esfuerzo-deformación en el tiempo bajo condiciones de trabajo del vehículo de carga para este caso de estudio.
In this paper we present the prototype of the Expert System for the Preeclampsia Prevention Progr... more In this paper we present the prototype of the Expert System for the Preeclampsia Prevention Program (ESPPP), a ruled-based medical expert system that supports diagnostic and therapeutic decisions in the realm of hypertensive disorders of pregnancy (HDP) and that could be used for training physicians and for guiding them to accurately perform all the activities of a public health program ("Preeclampsia Prevention Program"). ESPPP applies pragmatic criteria for diagnosing, classifying and suggesting the appropriate treatment of the HDP and their complications. This system guides the user for collecting patient information easily, and based on those items that leads to the possible diagnose and treatment for that patient. ESPPP has been developed for the Preeclampsia Prevention Program to be used by all physician that assist pregnant women in Mérida, Venezuela. ESPPP will be carefully evaluated and, if proven effective and accurate, it will be presented to practitioners a new tool for delivering high-quality, standard and individually adapted health care.
Resumen En este artículo se presenta el Sistema Experto para el Programa de Prevención de la Pree... more Resumen En este artículo se presenta el Sistema Experto para el Programa de Prevención de la Preeclampsia (SEPPP) sistema experto en medicina, basado en reglas, que apoya el diagnóstico y la toma de decisiones terapéuticas e campo de los desórdenes hipertensivos del embarazo (DHE), y que puede ser de utilidad para el entrenamient médicos y para guiarlos a ejecutar adecuadamente el programa de salud pública. SEPPP aplica criterios pragmát para clasificar, diagnosticar y sugerir el tratamiento de los DHE y sus complicaciones. Este sistema guía al usua recoger fácil y sistemáticamente la información de la paciente, y basado en esos datos puede llevar al po diagnóstico y tratamiento apropiado para esa paciente. SEPPP se ha desarrollado en el Programa de Prevención d Preeclampsia (PPP) para ser usado en los ambulatorios urbanos y rurales y en los hospitales del Distrito Sanit Mérida. El SEPPP será evaluado en la práctica y, si prueba ser eficaz y preciso, se procederá a ser presentado a médicos esta nueva herramienta para ofrecer servicios médicos de alta calidad, estandarizados e individualizados Palabras claves: Sistemas expertos, desórdenes hipertensivos del embarazo, preeclampsia, diagnóstico méd inteligencia artificial.
International audienceReliability of connectors is still a major concern for end users in many ap... more International audienceReliability of connectors is still a major concern for end users in many applications. One way to improve it is to optimize the surface coatings deposited on base substrates. Although gold remains the most widely used contact plating material, many alternative coatings have been developed in the past or recent years. Among these alternatives are silver final coatings and gold flash over palladium-nickel plated alloy. The properties of these two platings have been mainly investigated in symmetrical configurations where male and female contacts have similar deposits. In this work, asymmetrical configurations - where platings on male and female contacts are dissimilar - are studied. Wear behaviour was investigated with friction and fretting tests. The aim was to characterize the role of the various layers on the wear performances of contacts. Contact resistance behaviours were measured and correlated to the wear tracks investigated with various techniques such as ...
30th International Conference on Electrical Contacts - ICEC 2020, Jun 7, 2021
Plating systems of electrical contacts are key technologies for connectors in terms of electrical... more Plating systems of electrical contacts are key technologies for connectors in terms of electrical and mechanical reliability performance. Au/Ni is historically the reference plating system and Au/PdNi/Ni is widely used since 1986. More recently, plating systems like Au/Ag/Ni, Au/NiW, AgPd/Ni and AgSb/Ni were also introduced. Nevertheless, published scientific literature, concerning tribological compatibility of these various plating systems, is limited. This research work is a simplified approach to study compatibility, in terms of durability & wear, between Au/Ni, AuPdNi/Ni, Au/Ag/Ni and AgSb/Ni under different contact pressures or normal forces. Durability and frictional wear testing were performed. Various surface analysis techniques were used to analyze wear tracks and investigate wear mechanisms as well as their impact on contact resistance. Results show that terminal contact pressure range is a key parameter to take into account when mating two different platings. precious metals) and its moderate cost offset all its disadvantages. Silver plated connectors were historically rated for 50 mating/unmating cycles only. A lot of development work followed in the mid 2000's and new silver plating stacks and deposits were developed with pure silver showing much higher hardness and Young moduli. Several alloyed silver processes were also developed with deposits showing relatively very high hardness such as silver-antimony (AgSb) and silver-palladium (AgPd) [3,4]. Researchers developed improved organic or inorganic anti-tarnishing solutions as silver is naturally subject to sulfidation. Improved post-treatments were also developed such as new contact lubricants or low coefficient of friction grafted molecules. The objective was to extend silver usage to electronic connectors where more than 50 mating/unmating cycles are required, as gold and palladium prices have shown to be extremely volatile and unpredictable. We have seen, for example, AgSb plated connectors developed and commercialized, by several connector manufacturers, for Hybrid and Electrical vehicles where several thousands of mating/unmating cycles are required. This was unimaginable initially when considering silver plating. We have also seen gold over hard silver (GCS) plated electronic and power connectors [5,6] commercialized, when gold plated over silver engineering usage was limited, for decades, to special electrical switches [7] applications and special aerospace connectors.
En este trabajo, se realizó la simulación numérica de la respuesta dinámica de un sistema multicu... more En este trabajo, se realizó la simulación numérica de la respuesta dinámica de un sistema multicuerpo utilizando un modelo unidimensional (1D) implementado a través de elementos finitos (EF), para establecer una comparación con su modelo analítico propuesto en ecuaciones diferenciales ordinarias (EDO). El sistema multicuerpo seleccionado es uno de los objetos de estudio de la dinámica de sistemas vehiculares, un vehículo de transporte de carga constituido por cuerpos rígidos y cuerpos elásticos. Se obtuvieron resultados satisfactorios, con errores menores del 2.5% respecto al modelo teórico de referencia que validan el modelo numérico generado por métodos computacionales para el estudio dinámico y la factibilidad de ser empleado para modelar sistemas de esta índole y de mayor complejidad. Tales resultados conducen a afirmar la ventaja que ofrece el modelado numérico utilizando herramientas computacionales para incorporar algunas otras características del sistema multicuerpo que no son consideradas en los modelos analíticos simplificados, como lo es la integración entre el estudio del estado de esfuerzo-deformación en el tiempo bajo condiciones de trabajo del vehículo de carga para este caso de estudio.
In this paper we present the prototype of the Expert System for the Preeclampsia Prevention Progr... more In this paper we present the prototype of the Expert System for the Preeclampsia Prevention Program (ESPPP), a ruled-based medical expert system that supports diagnostic and therapeutic decisions in the realm of hypertensive disorders of pregnancy (HDP) and that could be used for training physicians and for guiding them to accurately perform all the activities of a public health program ("Preeclampsia Prevention Program"). ESPPP applies pragmatic criteria for diagnosing, classifying and suggesting the appropriate treatment of the HDP and their complications. This system guides the user for collecting patient information easily, and based on those items that leads to the possible diagnose and treatment for that patient. ESPPP has been developed for the Preeclampsia Prevention Program to be used by all physician that assist pregnant women in Mérida, Venezuela. ESPPP will be carefully evaluated and, if proven effective and accurate, it will be presented to practitioners a new tool for delivering high-quality, standard and individually adapted health care.
Resumen En este artículo se presenta el Sistema Experto para el Programa de Prevención de la Pree... more Resumen En este artículo se presenta el Sistema Experto para el Programa de Prevención de la Preeclampsia (SEPPP) sistema experto en medicina, basado en reglas, que apoya el diagnóstico y la toma de decisiones terapéuticas e campo de los desórdenes hipertensivos del embarazo (DHE), y que puede ser de utilidad para el entrenamient médicos y para guiarlos a ejecutar adecuadamente el programa de salud pública. SEPPP aplica criterios pragmát para clasificar, diagnosticar y sugerir el tratamiento de los DHE y sus complicaciones. Este sistema guía al usua recoger fácil y sistemáticamente la información de la paciente, y basado en esos datos puede llevar al po diagnóstico y tratamiento apropiado para esa paciente. SEPPP se ha desarrollado en el Programa de Prevención d Preeclampsia (PPP) para ser usado en los ambulatorios urbanos y rurales y en los hospitales del Distrito Sanit Mérida. El SEPPP será evaluado en la práctica y, si prueba ser eficaz y preciso, se procederá a ser presentado a médicos esta nueva herramienta para ofrecer servicios médicos de alta calidad, estandarizados e individualizados Palabras claves: Sistemas expertos, desórdenes hipertensivos del embarazo, preeclampsia, diagnóstico méd inteligencia artificial.
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