Ivan Guerrero Arias - Academia.edu (original) (raw)
Papers by Ivan Guerrero Arias
Un grupo interdisciplinario de estudiantes del Programa Semillero de Investigadores se dieron a l... more Un grupo interdisciplinario de estudiantes del Programa Semillero de Investigadores se dieron a la tarea de diseñar, con materiales económicos y de fácil consecución en el mercado, un prototipo de prótesis transtibial que mejora el modelo SACH. Para concretar el diseño, el proyecto realizó previamente un estudio cuantitativo para conocer aspectos psicológicos de personas con discapacidad física, y así determinar qué características convenía mejorar.Estudiantes del Programa Semillero de Investigadores desarrollaron un prototipo de prótesis de extremidad inferior o transtibial, para mejorar la calidad de vida de personas que pierden la capacidad de caminar.FUNDACIÓN FUNDAFE
IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium, 2018
A comparison between GPM Dual-frequency Precipitation Radar and ground-based radars located in So... more A comparison between GPM Dual-frequency Precipitation Radar and ground-based radars located in South America and the Caribbean is presented. The analysis compares radar variables from both system during overpasses of GPM over ground-based radars in the region of interest. Attenuation and bias correction is performed to ground radar data. The results show the potential of GPM to calibrate and monitor weather radars and subsequently using them for ground validation in Latin America and the Caribbean.
IGARSS 2019 - 2019 IEEE International Geoscience and Remote Sensing Symposium, 2019
This paper describes the deployment and features of CSU-CHIVO radar during the RELAMPAGO campaign... more This paper describes the deployment and features of CSU-CHIVO radar during the RELAMPAGO campaign in Argentina. Intercomparison with GPM-DPR is done using Volume Matching. Vertical profile analysis of storms is also shown and a list of GPM overpasses and summary of the tallest storms during the campaign are also included. The results show that CHIVO agree well with GPM in terms of reflectivity and microphysical structure of clouds and show the value of CHIVO for ground validation.
: The labelled preparation of the 'B' type botulismotoxin was obtained from the cultural ... more : The labelled preparation of the 'B' type botulismotoxin was obtained from the cultural fluid after growing 'Cl. botulinum' on a medium containing S35-methionine. The preparation was purified by a two-fold precipitation with ammonium sulfate and subsequent dialysis in the running fresh and distilled water. The obtained preparation of dry tagged botulisomotoxin was radioactive in the range of 1 mc/mg, while its toxicity equalled 5,000 Dlm/mg. The distribution of the labelled preparation was studied on white mice every 20, 60 and 150 minutes after an intravenous injection of 1,000 Dlm. The investigation covered: blood, brain, muscles, liver, kidneys, lungs, heart and intestines. The toxin preparation was found to rapidly find its way from the blood flow into body tissues. The highest radioactivity rate at all periods of the intoxication was recorded in the lungs, and the lowest - in the blood. During 150 minutes after intravenous administration of the tracer preparati...
RELAMPAGO (Remote sensing of Electrification, Lightning, And Mesoscale/microscale Processes with ... more RELAMPAGO (Remote sensing of Electrification, Lightning, And Mesoscale/microscale Processes with Adaptive Ground Observations) was an international field campaign that took place in Argentina near Sierras de Cordoba. It had an Intense Observing Period (IOP) from November 1st to December 15th of 2018 and an extended period that went until January 31st of 2019. In this paper we study Colorado State University C-band Hydrological Instrument for Volumetric Observation (CSU-CHIVO) and cross-compare it with GPM-DPR during the field campaign. CHIVO is also compared with C-band Scan Precipitation Radar 2 (CSAPR2) that is part of ARM and also was deployed during RELAMPAGO. Both radars were in the field for IOPs and the extended period.
Extended Abstract Remote sensing of Electrification, Lightning, And Mesoscale/microscale Processe... more Extended Abstract Remote sensing of Electrification, Lightning, And Mesoscale/microscale Processes with Adaptive Ground Observations (RELAMPAGO) field campaign has been conducted in the lee of the Andes Mountains in central Argentina. The lee of the Andes Mountains in central Argentina region is known for its high impact weather and some of the intense convective systems in the world. The intense events occur in terms of large hail (and the frequency of occurrences) and extreme lightning activities. However, the observations needed for the study of the convective events are scarce; this has been addressed during the RELAMPAGO experiment by performing various ground-based and airborne measurements. The repeated storms in this region have been sampled during the RELAMPAGO field campaign to study science questions related to the deep convective initiation, severeweather generation, and various stages of storm development [1]. As part of the experimental setup for RELAMPAGO, various ins...
Este libro trata sobre el acceso a la justicia de las personas privadas de libertad a partir de u... more Este libro trata sobre el acceso a la justicia de las personas privadas de libertad a partir de una tematica en especifico, que es la aplicacion de sanciones disciplinarias al interior de los penales. La publicacion de este libro que reune una investigacion tanto de los estandares internacionales en la materia como de la situacion en Chile, ha sido posible en el marco del proyecto “Acceso a la justicia de grupos en condicion de vulnerabilidad: privados de libertad y mujeres indigenas” a cargo del Centro de Derechos Humanos de la Facultad de Derecho de la Universidad de Chile que tiene como institucion socia al Instituto Nacional de Derechos Humanos y esta patrocinado por el Instrumento Europeo para la Democracia y los Derechos Humanos.
Por uso indiscriminado de pesticidas, segun la Organizacion Mundial de la Salud, tres millones de... more Por uso indiscriminado de pesticidas, segun la Organizacion Mundial de la Salud, tres millones de personas se intoxican al ano. En Ecuador segun datos del Ministerio de Salud Publica, las intoxicaciones por plaguicidas han aumentado en los ultimos cinco anos en 24,4%. En cultivadores fruticolas de Patate- Ecuador se evaluo clinica y epidemiologicamente los niveles de la colinesterasa (ChE), que estan asociados a toxicidad de los plaguicidas organofosforados (POFs) y los factores de riesgo existentes. Se determi- no la actividad de la colinesterasa serica en 250 muestras de fruticultores que emplean pesticidas, empleando la tecnica de TECO DIAGNOSTICS (PTC) con fotometro Mindray Ba-88-A, utilizado en quimica sanguinea. Como resultados del estudio, se obtuvo el valor medio de colinesterasa serica de 5.629,25 u/l; asi mismo, el 14,4% de los muestreados presentaron valores de colinesterasa menores a 4.000 u/l y mayores a 7.000 u/l. De los valores extremos con mas de 7.000 u/l, el 64% fu...
This paper presents microphysical inference retrievals obtained from spectral polarimetry during ... more This paper presents microphysical inference retrievals obtained from spectral polarimetry during the Relampago (Remote sensing of Electrification, Lightning, And Mesoscale/Microscale Processes with...
Journal of the Meteorological Society of Japan. Ser. II, 2021
The cross-validation of radars in a network is important in making consistent retrievals across t... more The cross-validation of radars in a network is important in making consistent retrievals across the domain and assuring the product quality. During the RELAMPAGO field campaign, two C-band radars, namely the Colorado State University C-band Hydrological Instrument for Volumetric Observations (CSU-CHIVO) and the C-band Scanning ARM Precipitation Radar (CSAPR-2), were deployed near the Sierras de Cordoba in Argentina, a region known for having some of the most intense severe weather in the world. In addition to these two radars, the operational radar of the Cordoba City, the Radar Meteorologico Argentino 1 (RMA-1), adds another instrument to the RELAMPAGO network. This study presents an intercomparison between the RELAMPAGO C-band radars using the GPM spaceborne radar as a common reference. A method to bring ground-based radars into better agreement is also proposed. Moreover, the attenuation correction for the C-band radar is studied in the context of intercomparing two radars. The attenuation coefficients are computed for the RELAMPAGO domain using the local disdrometers deployed during the campaign. After the attenuation correction, CSU-CHIVO, CSAPR-2, and RMA-1 compare well with GPM-DPR with a high correlation and bias less than 1 dB.
Bulletin of the American Meteorological Society, 2021
This article provides an overview of the experimental design, execution, education and public out... more This article provides an overview of the experimental design, execution, education and public outreach, data collection, and initial scientific results from the Remote Sensing of Electrification, Lightning, and Mesoscale/Microscale Processes with Adaptive Ground Observations (RELAMPAGO) field campaign. RELAMPAGO was a major field campaign conducted in the Córdoba and Mendoza provinces in Argentina and western Rio Grande do Sul State in Brazil in 2018–19 that involved more than 200 scientists and students from the United States, Argentina, and Brazil. This campaign was motivated by the physical processes and societal impacts of deep convection that frequently initiates in this region, often along the complex terrain of the Sierras de Córdoba and Andes, and often grows rapidly upscale into dangerous storms that impact society. Observed storms during the experiment produced copious hail, intense flash flooding, extreme lightning flash rates, and other unusual lightning phenomena, but f...
ECS Journal of Solid State Science and Technology, 2020
Revista Colombiana de Obstetricia y Ginecología, 2001
OBJETIVO: Evaluar el impacto de un modelo de Mejoramiento Continuo de la Atención Prenatal sobre ... more OBJETIVO: Evaluar el impacto de un modelo de Mejoramiento Continuo de la Atención Prenatal sobre la morbilidad materna y la morbimortalidad Perinatal.DISEÑO: Estudio prospectivo descriptivo.MATERIALES Y METODOS: Entre Enero de 1997 y Mayo de 1998, se evaluó la calidad de la atención ofrecida a las pacientes que asistieron a control prenatal en el Centro de Atención Ambulatoria del Instituto de Seguros Sociales (CAA - ISS) y el Centro de Salud Suroccidente del Servicio de Salud del Cauca (CSS -SS) de la ciudad de Popayán. Después de un período de observación de cinco meses, la intervención, realizada en los doce meses siguientes, consistió en la aplicación de un modelo de control de calidad, utilizando un formato diseñado para evaluar el correcto diligenciamiento de 92 variables de la Historia Clínica Perinatal, que permitía además la supervisión y la asesoría continua del personal que realizaba el control. Se analizó el diligenciamiento de 22.292 variables que correspondieron a una ...
Revista Colombiana de Obstetricia y Ginecología, 2001
El dispositivo subdérmico NORPLANT® (L-Norgestrel) ha sido extensamente utilizado como anticoncep... more El dispositivo subdérmico NORPLANT® (L-Norgestrel) ha sido extensamente utilizado como anticonceptivo en todo el mundo desde hace más de quince años, demostrando ser un método reversible, seguro, efectivo y de alta aceptación por las usuarias. Entre las escasas complicaciones locales se destacan dolor, hematomas, infecciones, expulsión del implante y diversas lesiones neurológicas. Hasta la fecha no se ha informado en la literatura (MEDLINE hasta Diciembre de 2000) ningún caso de Distrofia Simpática Refleja (Síndrome Doloroso Regional Complejo Tipo-I) asociado a la utilización de este moderno método.Se presenta el caso de una usuaria de este dispositivo, que presentó un cuadro característico de Distrofia Simpática Refleja en el brazo izquierdo después de colocársele un NORPLANT® (L-Norgestrel), que evolucionó desde el momento de su inserción hasta su extracción tres años después, con remisión total del Síndrome doloroso.
, to April 30, 2019. This campaign was comprised of more than 150 scientists from 10 organization... more , to April 30, 2019. This campaign was comprised of more than 150 scientists from 10 organizations. Data was collected to investigate different phases of the life cycle of thunderstorms that occur in Argentina to better understand the physical mechanisms that cause the initiation and growth of organized convective systems in some of the most intense storms on the planet. The main focus of the project was to develop new conceptual models for forecasting extreme weather events that will hopefully lead to reductions in future loss of life and property. This presentation shows the performance of a recently developed model for estimating ice mass aloft, a key component in the atmospheric electrification process, and a method for nowcasting lightning activity using C-band weather radar and Global Lightning Dataset (GLD360) data from RELAMPAGO. This nowcasting method uses a grid-based approach to make specific forecasts of lightning in space and time. The method estimates ice mass aloft in the region where electrification occurs using a numerical optimization approach to essentially reframe a simplified bulk microphysical model into a completely data-driven model. Previous results using WSR-88D Sband radar data in the United States showed that using this model significantly improved nowcasts of first-flash lightning occurrence versus the traditional weather radar-based ice mass estimator as well as using lightning flash-rate density directly.
Materials Research Express, 2019
Materials Research Express, 2019
The thermoresistivity and piezoresistivity of gold films with thicknesses of 10, 20, and 40 nm we... more The thermoresistivity and piezoresistivity of gold films with thicknesses of 10, 20, and 40 nm were analyzed. The films were thermally evaporated and deposited onto polyimide (Kapton®) substrates. Because of their nanometric thickness, the films required a post-deposition annealing to yield reproducible piezoresistive responses. Separation of each contributing factor and proper analytical models capturing the thermoresistivity and piezoresistivity responses were used for determining the gage factor (GF) and the temperature coefficient of resistance (TCR) of the films. The obtained GF values varied between 2.52 and 2.88, and the TCR values from (6.25 to 9.81) × 10−4 °C−1. The TCR is about one fourth of the value typically reported for a bulk material. It was also observed that the electrical current used to measure the electrical resistance causes important heating of the films. These phenomena are relevant and must be taken into account in the case of electrical currents flowing through metallic nanofilms, either when designing experiments or as part of a device.
Un grupo interdisciplinario de estudiantes del Programa Semillero de Investigadores se dieron a l... more Un grupo interdisciplinario de estudiantes del Programa Semillero de Investigadores se dieron a la tarea de diseñar, con materiales económicos y de fácil consecución en el mercado, un prototipo de prótesis transtibial que mejora el modelo SACH. Para concretar el diseño, el proyecto realizó previamente un estudio cuantitativo para conocer aspectos psicológicos de personas con discapacidad física, y así determinar qué características convenía mejorar.Estudiantes del Programa Semillero de Investigadores desarrollaron un prototipo de prótesis de extremidad inferior o transtibial, para mejorar la calidad de vida de personas que pierden la capacidad de caminar.FUNDACIÓN FUNDAFE
IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium, 2018
A comparison between GPM Dual-frequency Precipitation Radar and ground-based radars located in So... more A comparison between GPM Dual-frequency Precipitation Radar and ground-based radars located in South America and the Caribbean is presented. The analysis compares radar variables from both system during overpasses of GPM over ground-based radars in the region of interest. Attenuation and bias correction is performed to ground radar data. The results show the potential of GPM to calibrate and monitor weather radars and subsequently using them for ground validation in Latin America and the Caribbean.
IGARSS 2019 - 2019 IEEE International Geoscience and Remote Sensing Symposium, 2019
This paper describes the deployment and features of CSU-CHIVO radar during the RELAMPAGO campaign... more This paper describes the deployment and features of CSU-CHIVO radar during the RELAMPAGO campaign in Argentina. Intercomparison with GPM-DPR is done using Volume Matching. Vertical profile analysis of storms is also shown and a list of GPM overpasses and summary of the tallest storms during the campaign are also included. The results show that CHIVO agree well with GPM in terms of reflectivity and microphysical structure of clouds and show the value of CHIVO for ground validation.
: The labelled preparation of the 'B' type botulismotoxin was obtained from the cultural ... more : The labelled preparation of the 'B' type botulismotoxin was obtained from the cultural fluid after growing 'Cl. botulinum' on a medium containing S35-methionine. The preparation was purified by a two-fold precipitation with ammonium sulfate and subsequent dialysis in the running fresh and distilled water. The obtained preparation of dry tagged botulisomotoxin was radioactive in the range of 1 mc/mg, while its toxicity equalled 5,000 Dlm/mg. The distribution of the labelled preparation was studied on white mice every 20, 60 and 150 minutes after an intravenous injection of 1,000 Dlm. The investigation covered: blood, brain, muscles, liver, kidneys, lungs, heart and intestines. The toxin preparation was found to rapidly find its way from the blood flow into body tissues. The highest radioactivity rate at all periods of the intoxication was recorded in the lungs, and the lowest - in the blood. During 150 minutes after intravenous administration of the tracer preparati...
RELAMPAGO (Remote sensing of Electrification, Lightning, And Mesoscale/microscale Processes with ... more RELAMPAGO (Remote sensing of Electrification, Lightning, And Mesoscale/microscale Processes with Adaptive Ground Observations) was an international field campaign that took place in Argentina near Sierras de Cordoba. It had an Intense Observing Period (IOP) from November 1st to December 15th of 2018 and an extended period that went until January 31st of 2019. In this paper we study Colorado State University C-band Hydrological Instrument for Volumetric Observation (CSU-CHIVO) and cross-compare it with GPM-DPR during the field campaign. CHIVO is also compared with C-band Scan Precipitation Radar 2 (CSAPR2) that is part of ARM and also was deployed during RELAMPAGO. Both radars were in the field for IOPs and the extended period.
Extended Abstract Remote sensing of Electrification, Lightning, And Mesoscale/microscale Processe... more Extended Abstract Remote sensing of Electrification, Lightning, And Mesoscale/microscale Processes with Adaptive Ground Observations (RELAMPAGO) field campaign has been conducted in the lee of the Andes Mountains in central Argentina. The lee of the Andes Mountains in central Argentina region is known for its high impact weather and some of the intense convective systems in the world. The intense events occur in terms of large hail (and the frequency of occurrences) and extreme lightning activities. However, the observations needed for the study of the convective events are scarce; this has been addressed during the RELAMPAGO experiment by performing various ground-based and airborne measurements. The repeated storms in this region have been sampled during the RELAMPAGO field campaign to study science questions related to the deep convective initiation, severeweather generation, and various stages of storm development [1]. As part of the experimental setup for RELAMPAGO, various ins...
Este libro trata sobre el acceso a la justicia de las personas privadas de libertad a partir de u... more Este libro trata sobre el acceso a la justicia de las personas privadas de libertad a partir de una tematica en especifico, que es la aplicacion de sanciones disciplinarias al interior de los penales. La publicacion de este libro que reune una investigacion tanto de los estandares internacionales en la materia como de la situacion en Chile, ha sido posible en el marco del proyecto “Acceso a la justicia de grupos en condicion de vulnerabilidad: privados de libertad y mujeres indigenas” a cargo del Centro de Derechos Humanos de la Facultad de Derecho de la Universidad de Chile que tiene como institucion socia al Instituto Nacional de Derechos Humanos y esta patrocinado por el Instrumento Europeo para la Democracia y los Derechos Humanos.
Por uso indiscriminado de pesticidas, segun la Organizacion Mundial de la Salud, tres millones de... more Por uso indiscriminado de pesticidas, segun la Organizacion Mundial de la Salud, tres millones de personas se intoxican al ano. En Ecuador segun datos del Ministerio de Salud Publica, las intoxicaciones por plaguicidas han aumentado en los ultimos cinco anos en 24,4%. En cultivadores fruticolas de Patate- Ecuador se evaluo clinica y epidemiologicamente los niveles de la colinesterasa (ChE), que estan asociados a toxicidad de los plaguicidas organofosforados (POFs) y los factores de riesgo existentes. Se determi- no la actividad de la colinesterasa serica en 250 muestras de fruticultores que emplean pesticidas, empleando la tecnica de TECO DIAGNOSTICS (PTC) con fotometro Mindray Ba-88-A, utilizado en quimica sanguinea. Como resultados del estudio, se obtuvo el valor medio de colinesterasa serica de 5.629,25 u/l; asi mismo, el 14,4% de los muestreados presentaron valores de colinesterasa menores a 4.000 u/l y mayores a 7.000 u/l. De los valores extremos con mas de 7.000 u/l, el 64% fu...
This paper presents microphysical inference retrievals obtained from spectral polarimetry during ... more This paper presents microphysical inference retrievals obtained from spectral polarimetry during the Relampago (Remote sensing of Electrification, Lightning, And Mesoscale/Microscale Processes with...
Journal of the Meteorological Society of Japan. Ser. II, 2021
The cross-validation of radars in a network is important in making consistent retrievals across t... more The cross-validation of radars in a network is important in making consistent retrievals across the domain and assuring the product quality. During the RELAMPAGO field campaign, two C-band radars, namely the Colorado State University C-band Hydrological Instrument for Volumetric Observations (CSU-CHIVO) and the C-band Scanning ARM Precipitation Radar (CSAPR-2), were deployed near the Sierras de Cordoba in Argentina, a region known for having some of the most intense severe weather in the world. In addition to these two radars, the operational radar of the Cordoba City, the Radar Meteorologico Argentino 1 (RMA-1), adds another instrument to the RELAMPAGO network. This study presents an intercomparison between the RELAMPAGO C-band radars using the GPM spaceborne radar as a common reference. A method to bring ground-based radars into better agreement is also proposed. Moreover, the attenuation correction for the C-band radar is studied in the context of intercomparing two radars. The attenuation coefficients are computed for the RELAMPAGO domain using the local disdrometers deployed during the campaign. After the attenuation correction, CSU-CHIVO, CSAPR-2, and RMA-1 compare well with GPM-DPR with a high correlation and bias less than 1 dB.
Bulletin of the American Meteorological Society, 2021
This article provides an overview of the experimental design, execution, education and public out... more This article provides an overview of the experimental design, execution, education and public outreach, data collection, and initial scientific results from the Remote Sensing of Electrification, Lightning, and Mesoscale/Microscale Processes with Adaptive Ground Observations (RELAMPAGO) field campaign. RELAMPAGO was a major field campaign conducted in the Córdoba and Mendoza provinces in Argentina and western Rio Grande do Sul State in Brazil in 2018–19 that involved more than 200 scientists and students from the United States, Argentina, and Brazil. This campaign was motivated by the physical processes and societal impacts of deep convection that frequently initiates in this region, often along the complex terrain of the Sierras de Córdoba and Andes, and often grows rapidly upscale into dangerous storms that impact society. Observed storms during the experiment produced copious hail, intense flash flooding, extreme lightning flash rates, and other unusual lightning phenomena, but f...
ECS Journal of Solid State Science and Technology, 2020
Revista Colombiana de Obstetricia y Ginecología, 2001
OBJETIVO: Evaluar el impacto de un modelo de Mejoramiento Continuo de la Atención Prenatal sobre ... more OBJETIVO: Evaluar el impacto de un modelo de Mejoramiento Continuo de la Atención Prenatal sobre la morbilidad materna y la morbimortalidad Perinatal.DISEÑO: Estudio prospectivo descriptivo.MATERIALES Y METODOS: Entre Enero de 1997 y Mayo de 1998, se evaluó la calidad de la atención ofrecida a las pacientes que asistieron a control prenatal en el Centro de Atención Ambulatoria del Instituto de Seguros Sociales (CAA - ISS) y el Centro de Salud Suroccidente del Servicio de Salud del Cauca (CSS -SS) de la ciudad de Popayán. Después de un período de observación de cinco meses, la intervención, realizada en los doce meses siguientes, consistió en la aplicación de un modelo de control de calidad, utilizando un formato diseñado para evaluar el correcto diligenciamiento de 92 variables de la Historia Clínica Perinatal, que permitía además la supervisión y la asesoría continua del personal que realizaba el control. Se analizó el diligenciamiento de 22.292 variables que correspondieron a una ...
Revista Colombiana de Obstetricia y Ginecología, 2001
El dispositivo subdérmico NORPLANT® (L-Norgestrel) ha sido extensamente utilizado como anticoncep... more El dispositivo subdérmico NORPLANT® (L-Norgestrel) ha sido extensamente utilizado como anticonceptivo en todo el mundo desde hace más de quince años, demostrando ser un método reversible, seguro, efectivo y de alta aceptación por las usuarias. Entre las escasas complicaciones locales se destacan dolor, hematomas, infecciones, expulsión del implante y diversas lesiones neurológicas. Hasta la fecha no se ha informado en la literatura (MEDLINE hasta Diciembre de 2000) ningún caso de Distrofia Simpática Refleja (Síndrome Doloroso Regional Complejo Tipo-I) asociado a la utilización de este moderno método.Se presenta el caso de una usuaria de este dispositivo, que presentó un cuadro característico de Distrofia Simpática Refleja en el brazo izquierdo después de colocársele un NORPLANT® (L-Norgestrel), que evolucionó desde el momento de su inserción hasta su extracción tres años después, con remisión total del Síndrome doloroso.
, to April 30, 2019. This campaign was comprised of more than 150 scientists from 10 organization... more , to April 30, 2019. This campaign was comprised of more than 150 scientists from 10 organizations. Data was collected to investigate different phases of the life cycle of thunderstorms that occur in Argentina to better understand the physical mechanisms that cause the initiation and growth of organized convective systems in some of the most intense storms on the planet. The main focus of the project was to develop new conceptual models for forecasting extreme weather events that will hopefully lead to reductions in future loss of life and property. This presentation shows the performance of a recently developed model for estimating ice mass aloft, a key component in the atmospheric electrification process, and a method for nowcasting lightning activity using C-band weather radar and Global Lightning Dataset (GLD360) data from RELAMPAGO. This nowcasting method uses a grid-based approach to make specific forecasts of lightning in space and time. The method estimates ice mass aloft in the region where electrification occurs using a numerical optimization approach to essentially reframe a simplified bulk microphysical model into a completely data-driven model. Previous results using WSR-88D Sband radar data in the United States showed that using this model significantly improved nowcasts of first-flash lightning occurrence versus the traditional weather radar-based ice mass estimator as well as using lightning flash-rate density directly.
Materials Research Express, 2019
Materials Research Express, 2019
The thermoresistivity and piezoresistivity of gold films with thicknesses of 10, 20, and 40 nm we... more The thermoresistivity and piezoresistivity of gold films with thicknesses of 10, 20, and 40 nm were analyzed. The films were thermally evaporated and deposited onto polyimide (Kapton®) substrates. Because of their nanometric thickness, the films required a post-deposition annealing to yield reproducible piezoresistive responses. Separation of each contributing factor and proper analytical models capturing the thermoresistivity and piezoresistivity responses were used for determining the gage factor (GF) and the temperature coefficient of resistance (TCR) of the films. The obtained GF values varied between 2.52 and 2.88, and the TCR values from (6.25 to 9.81) × 10−4 °C−1. The TCR is about one fourth of the value typically reported for a bulk material. It was also observed that the electrical current used to measure the electrical resistance causes important heating of the films. These phenomena are relevant and must be taken into account in the case of electrical currents flowing through metallic nanofilms, either when designing experiments or as part of a device.