Zeolites offer an interesting type of matrix for confinement of magnetic materials at the nanosco... more Zeolites offer an interesting type of matrix for confinement of magnetic materials at the nanoscopic level. We report on magnetic measurements performed on iron containing ZSM-5 zeolite. The ac susceptibility is sensitive to the extraction of iron ions from the zeolite framework by controlled thermal and hydrothermal treatments, forming small extra-framework iron oxide clusters.
En la Repûblica Dominicana, la producciôn de vegetales en invernaderos ha incrementado, motivada ... more En la Repûblica Dominicana, la producciôn de vegetales en invernaderos ha incrementado, motivada por el hecho de que los rendimientos alcanzados superan los niveles obtenidos a campo abierto. En el 2004, existian 268,800 m2 en producciôn y a finales del 2009 llegô a 2,946 millones, con diferentes tipos de estructuras y tecnologias de manejo. En general, los productores deciden seleccionar la inversion sobre criterios débiles por desconocimiento de las distintas opciones econômicas existentes. El objetivo de este trabajo fue caracterizar la producciôn de vegetales en ambiente protegido. El diagnôstico se realizô en Jarabacoa, Constanza, San José de Ocoa, Villa Trina y Moca, que representan 71% del total de ârea bajo invernadero. Se encuestaron 147 productores mediante entrevista estructurada, los cuales estaban distribuidos proporcionalmente en las cinco localidades. Los resultados indican que existen invernaderos con estructura de metal (= 4800 m2) y de madera (850 a 2600 m2). Para ...
EN EL MUSEO UNIVERSITARIO DEL CHOPO SE LLEVO A CABO LA INAUGURACION DE LAS EXPOSICIONES: PINTURA ... more EN EL MUSEO UNIVERSITARIO DEL CHOPO SE LLEVO A CABO LA INAUGURACION DE LAS EXPOSICIONES: PINTURA DF, DEL ARTISTA CUBANO CARLOS GARCIA, Y LA PRECISION DE LA INCERTIDUMBRE, DE CESAR MARTINEZ. LA PRIMERA, QUE PERMANECERA ABIERTA HASTA EL 24 DE ABRIL, MUESTRA IMAGENES ABSTRACTAS EN GRIS, MIENTRAS QUE LA SEGUNDA, QUE SE CLAUSURA EL 17, ESTA HECHA CON FUEGOS ARTIFICIALES.
This article describes the development of a library for Matlab (The MathWorks, Inc.) for sounds r... more This article describes the development of a library for Matlab (The MathWorks, Inc.) for sounds recognition based on Spiking Neural Networks. The mathematical model of the integrate and fire type is presented. The main modules of the library are as follows: encoding in “spikes”, spiking neural network and finally the training module. To illustrate its use, the library application to the task of phoneme recognition is presented.
As-synthesized, low iron content, ferrisilicates of ZSM-5-type contain well-separated Fe(III) ion... more As-synthesized, low iron content, ferrisilicates of ZSM-5-type contain well-separated Fe(III) ions in a tetrahedral environment and display paramagnetic behavior. After hydrothermal treatment, the iron ions are partially extracted from the framework, generating nanosize iron oxide or oxyhydroxide ferrimagnetic particles. This process has been studied by transmission electron microscopy (TEM), Mössbauer spectroscopy, magnetic ac susceptibility (χac), and field dependent magnetization, on samples containing up to 6.7 wt.% Fe. The experiments evidence the growth of nonaggregated particles, with a typical size around 3 nm, presumably located at the surface of the ferrisilicate crystallites. From a thorough granulometric analysis involving TEM and χacdata, it is concluded that, in the range from 1.5 to 4.6 wt.% Fe, the particle size distributions are significantly independent of the iron content.
International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases, 2011
Outcomes of community-acquired pneumonia (CAP) in relation to CD4+ cell counts have not been esta... more Outcomes of community-acquired pneumonia (CAP) in relation to CD4+ cell counts have not been established. We examined the correlation of CD4+ cell count and HIV-RNA level with the clinical outcomes of CAP in hospitalized HIV-infected patients.
Zeolites offer an interesting type of matrix for confinement of magnetic materials at the nanosco... more Zeolites offer an interesting type of matrix for confinement of magnetic materials at the nanoscopic level. We report on magnetic measurements performed on iron containing ZSM-5 zeolite. The ac susceptibility is sensitive to the extraction of iron ions from the zeolite framework by controlled thermal and hydrothermal treatments, forming small extra-framework iron oxide clusters.
En la Repûblica Dominicana, la producciôn de vegetales en invernaderos ha incrementado, motivada ... more En la Repûblica Dominicana, la producciôn de vegetales en invernaderos ha incrementado, motivada por el hecho de que los rendimientos alcanzados superan los niveles obtenidos a campo abierto. En el 2004, existian 268,800 m2 en producciôn y a finales del 2009 llegô a 2,946 millones, con diferentes tipos de estructuras y tecnologias de manejo. En general, los productores deciden seleccionar la inversion sobre criterios débiles por desconocimiento de las distintas opciones econômicas existentes. El objetivo de este trabajo fue caracterizar la producciôn de vegetales en ambiente protegido. El diagnôstico se realizô en Jarabacoa, Constanza, San José de Ocoa, Villa Trina y Moca, que representan 71% del total de ârea bajo invernadero. Se encuestaron 147 productores mediante entrevista estructurada, los cuales estaban distribuidos proporcionalmente en las cinco localidades. Los resultados indican que existen invernaderos con estructura de metal (= 4800 m2) y de madera (850 a 2600 m2). Para ...
EN EL MUSEO UNIVERSITARIO DEL CHOPO SE LLEVO A CABO LA INAUGURACION DE LAS EXPOSICIONES: PINTURA ... more EN EL MUSEO UNIVERSITARIO DEL CHOPO SE LLEVO A CABO LA INAUGURACION DE LAS EXPOSICIONES: PINTURA DF, DEL ARTISTA CUBANO CARLOS GARCIA, Y LA PRECISION DE LA INCERTIDUMBRE, DE CESAR MARTINEZ. LA PRIMERA, QUE PERMANECERA ABIERTA HASTA EL 24 DE ABRIL, MUESTRA IMAGENES ABSTRACTAS EN GRIS, MIENTRAS QUE LA SEGUNDA, QUE SE CLAUSURA EL 17, ESTA HECHA CON FUEGOS ARTIFICIALES.
This article describes the development of a library for Matlab (The MathWorks, Inc.) for sounds r... more This article describes the development of a library for Matlab (The MathWorks, Inc.) for sounds recognition based on Spiking Neural Networks. The mathematical model of the integrate and fire type is presented. The main modules of the library are as follows: encoding in “spikes”, spiking neural network and finally the training module. To illustrate its use, the library application to the task of phoneme recognition is presented.
As-synthesized, low iron content, ferrisilicates of ZSM-5-type contain well-separated Fe(III) ion... more As-synthesized, low iron content, ferrisilicates of ZSM-5-type contain well-separated Fe(III) ions in a tetrahedral environment and display paramagnetic behavior. After hydrothermal treatment, the iron ions are partially extracted from the framework, generating nanosize iron oxide or oxyhydroxide ferrimagnetic particles. This process has been studied by transmission electron microscopy (TEM), Mössbauer spectroscopy, magnetic ac susceptibility (χac), and field dependent magnetization, on samples containing up to 6.7 wt.% Fe. The experiments evidence the growth of nonaggregated particles, with a typical size around 3 nm, presumably located at the surface of the ferrisilicate crystallites. From a thorough granulometric analysis involving TEM and χacdata, it is concluded that, in the range from 1.5 to 4.6 wt.% Fe, the particle size distributions are significantly independent of the iron content.
International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases, 2011
Outcomes of community-acquired pneumonia (CAP) in relation to CD4+ cell counts have not been esta... more Outcomes of community-acquired pneumonia (CAP) in relation to CD4+ cell counts have not been established. We examined the correlation of CD4+ cell count and HIV-RNA level with the clinical outcomes of CAP in hospitalized HIV-infected patients.
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