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Search Results: 1 - 10 of 7546 matches for " Lilia Beatriz Vence "
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Disponibilidad de agua-aire en sustratos para plantas
Vence,Lilia Beatriz;
Ciencia del suelo , 2008,
Abstract: the study of the physical properties of substrates for container plant production is very important because the water and air availability for plant roots is involved. a substrate must contain a sufficient amount of available water and air to produce an optimum plant growth and development. worldwide, the study of the properties that determine the water and air availability started from soil sciences and has been evolving to the present existence of a great variety of products that can be used, concomitant with the identification of parameters and specific measurement methods for the physical characterization of the substrates. in argentina, the study of plant substrates is a new area under development and it demands an interdisciplinary work that should agree with a common language of technical terms, the election of specific analytical methods of reference and an updated legislation for substrate materials. a critical assessment of the great amount of information provided by other countries could be adapted to our reality and our materials. in this review, we listed the most important concepts for the physical evaluation of the substrates as the foundation for a better understanding and discussion of the subject.
Disponibilidad de agua-aire en sustratos para plantas Water-air availability in plant substrates
Lilia Beatriz Vence
Ciencia del Suelo , 2008,
Abstract: Las propiedades físicas de los sustratos especialmente las relacionadas con la disponibilidad de agua-aire para las raíces de las plantas son las más importantes dentro del estudio de estos materiales usados en cultivos en contenedores. Para un óptimo crecimiento de la planta un sustrato debe contener suficiente cantidad de agua y aire y ambos estar disponibles. A nivel mundial el estudio de las propiedades que determinan esta disponibilidad comenzó desde las ciencias del suelo y fue adaptándose a las características propias de la amplia gama de productos que pueden ser utilizados, surgiendo así variables y métodos de medida específicos para la caracterización física de sustratos. En la Argentina el estudio de sustratos para plantas constituye un área de conocimiento nueva y en desarrollo, por ello exige un trabajo interdisciplinario donde hay que concordar un lenguaje común de términos técnicos, la elección de los métodos analíticos de referencia específicos y una legislación actualizada para sustratos. Haciendo un estudio crítico de la gran cantidad de información al respecto que proviene de otros países se podrán adaptar a nuestra realidad y a nuestros materiales. En esta revisión se enumeran resumidamente los más importantes conceptos a tener en cuenta para la evaluación física de sustratos a fin de que puedan servir de base para una mejor comprensión y discusión del tema. The study of the physical properties of substrates for container plant production is very important because the water and air availability for plant roots is involved. A substrate must contain a sufficient amount of available water and air to produce an optimum plant growth and development. Worldwide, the study of the properties that determine the water and air availability started from soil sciences and has been evolving to the present existence of a great variety of products that can be used, concomitant with the identification of parameters and specific measurement methods for the physical characterization of the substrates. In Argentina, the study of plant substrates is a new area under development and it demands an interdisciplinary work that should agree with a common language of technical terms, the election of specific analytical methods of reference and an updated legislation for substrate materials. A critical assessment of the great amount of information provided by other countries could be adapted to our reality and our materials. In this review, we listed the most important concepts for the physical evaluation of the substrates as the foundation for a better understan
Propiedades físicas e hidráulicas de perlita en cultivos de rosas y sus variaciones temporales Physical and hydraulic properties of perlites used in rose cultures and their dependency on time
Daniel A. Martínez,Ana María Landini,Héctor Svartz,Lilia Vence
Ciencia del Suelo , 2006,
Abstract: Se evaluaron las características físicas e hidráulicas de la perlita usada como sustrato único, en un cultivo bajo cubierta de rosas (Rosa hybrida L.) para corte, observando su comportamiento durante el cultivo. Se evaluaron muestras de perlita con 0, 28 y 39 meses de uso extraídas de la zona radicular del cultivo. Se determinaron la densidad aparente (DA), densidad real de las partículas intactas (DRI), densidad real de las partículas pulverizadas (DRP), distribución de tama o de partícula, capacidad de aire (CA), agua fácilmente disponible (AF), agua de reserva (AR), porosidad efectiva (PE). La conductividad hidráulica no saturada (Kns) se obtuvo a partir del modelo de Mualem-van Genuchten. La perlita registró en el tiempo, rotura de los granos superiores a 2 mm, observándose un incremento de la fracción comprendida entre 1 mm y 2 mm, no habiendo modificaciones significativas en partículas inferiores a 0,5 mm. Se observó un aumento de la PE, y de la CA mientras que los valores de AF, AR se mantuvieron aproximadamente constantes. El aumento de PE podría explicarse como resultado de la inserción de las raíces y el arrastre de las partículas finas fuera de la zona radicular. En cambio, de forma consistente con el aumento de la CA, Kns experimentó una disminución en un orden de magnitud luego de 39 meses. Physical and hydraulic properties of perlite used as unique substrate in a greenhouse cut roses (Rosa hybrida L.) culture and their dependence on time were investigated. Samples of, perlite with 0,28 and 39 months of use, extracted from the rhizosphere, were analyzed. Bulk density (DA), real density of intact particles (DRI) real density of pulverized particles (DRP), particle size distribution, air capacity (CA), available water (AFD), unavailable water (AR) and effective porosity (PE) were determined. Non-saturated hydraulic conductivity (Kns) was obtained using the Mualemvan Genuchten model. It was found cracking of particles with diameters greater than 2 mm and an increment of the fraction between 1 mm and 2 mm after 28 and 39 months of use. No significant alteration of particles with diameters smaller than 0,5 mm was found. Values of PE and CA increased with time of use, while values of AFD, AR showed no variation. The increment of PE with time of use could be explained as a consequence of particle breakdown due to roots, or tiny particle drift from the rhizosphere. Accordingly with the increment of CA, a diminution in one order of magnitude of Kns after 39 months of use was found.
Propiedades físicas e hidráulicas de perlita en cultivos de rosas y sus variaciones temporales
Martínez,Daniel A.; Landini,Ana María; Svartz,Héctor; Vence,Lilia; Bottini,Lucila; Mascarini,Libertad; Orden,Susana; Villela,Fernando;
Ciencia del suelo , 2006,
Abstract: physical and hydraulic properties of perlite used as unique substrate in a greenhouse cut roses (rosa hybrida l.) culture and their dependence on time were investigated. samples of, perlite with 0,28 and 39 months of use, extracted from the rhizosphere, were analyzed. bulk density (da), real density of intact particles (dri) real density of pulverized particles (drp), particle size distribution, air capacity (ca), available water (afd), unavailable water (ar) and effective porosity (pe) were determined. non-saturated hydraulic conductivity (kns) was obtained using the mualemvan genuchten model. it was found cracking of particles with diameters greater than 2 mm and an increment of the fraction between 1 mm and 2 mm after 28 and 39 months of use. no significant alteration of particles with diameters smaller than 0,5 mm was found. values of pe and ca increased with time of use, while values of afd, ar showed no variation. the increment of pe with time of use could be explained as a consequence of particle breakdown due to roots, or tiny particle drift from the rhizosphere. accordingly with the increment of ca, a diminution in one order of magnitude of kns after 39 months of use was found.
SISTEMA GALLEGO DE INNOVACIóN Y POLíTICAS DE INNOVACIóN: BALANCE DE UNA DéCADA
XAVIER VENCE DEZA
Revista Galega de Economía , 2010,
Abstract: Se realiza un análisis de los rasgos más importantes de la evolución del sistema gallego de innovación a lo largo de la última década. Se examina la posición relativa de Galicia en el marco europeo con base en los indicadores sintéticos de innovación y se examinan las tendencias evolutivas con base en los indicadores de input y output de las actividades de I+D y de innovación. Se hace también un balance de las políticas de I+D e innovación del Gobierno autónomo, así como de los cambios en la configuración de la ense anza superior.
Cambio estrutural e innovación en la economía gallega. Los retos en el umbral del siglo XXI
Xavier Vence Deza
Revista Galega de Economía , 2000,
Abstract: Se analiza el proceso de cambio estructural y de transformación de la economía gallega a lo largo del último cuarto de siglo desde las perspectivas de la teoría de los sistemas nacionales de innovación (SNI) y de la teoría de la regulación. Para ello se abordan las principales transformaciones que tienen lugar en la base productiva y la incidencia que los diferentes elementos del SNI (estructura productiva, sistema financiero, sistema de I+D, educación, políticas públicas, etc.) tuvieron sobre la capacidad de adaptación e innovación de los principales sectores de nuestra economía, especialmente el agrario y el industrial. La existencia de segmentos innovadores en ambos sectores no es suficente para contrarrestar el perfil de declive de nuestra economía en este período. Del diagnóstico de los factores, externos e internos, que condicionaron nuestra evolución en el pasado inmediato pueden vislumbrarse los obstáculos que es preciso superar para que la economía gallega mejore, o por lo menos mantenga, sus posiciones en el marco de la Unión Europea.
Key business factors for eco-innovation: an overview of recent firm-level empirical studies
ángeles Pereira,Xavier Vence
Cuadernos de Gestión , 2012,
Abstract: The increasing interest in eco-innovation or environmental innovation as a strategy not only to address the serious global environmental problems but also as a source of competitive advantages for companies and for the emergence of new business areas, leads us to try to identify the different factors that act as determinants of its development and adoption at the micro level. In this paper we integrate the findings from several recent empirical studies according to our own classification of factors derived from the variables used in those analyses. From a conventional perspective we referred to the structural characteristics of firms (size, sector, age), the business logic (cost savings, market expansion) or to its technological competence (R&D, path dependencies, qualification of staff and management, cooperation and participation in networks, etc.). We added another category to refer to organizational or marketing innovations that reflect the existence of a certain environmental strategy within the company. In general, the findings show that factors influencing conventional innovation also work in relation to eco-innovation, in particular those related to cost savings and technological competence. Therefore, along with a stringent environmental regulation (justified because of the specific characteristics of eco-innovation) specific supply and demand side instruments are convenient. Measures to disseminate environmental information amongst all stakeholders can also be very useful to promote environmentally friendly and economically viable products and processes, as well as forms of organization and new business.
Concomitancia de fibromialgia em pacientes portadores de hipotireoidismo e de altera??es tireoideanas em pacientes com fibromialgia
Freire, Marlene;Teodoro, Reginaldo B.;Oliveira, Lilia Beatriz;Cunha, Selma Freire C.;Ferreira, Beatriz P.;Borges, Maria de Fátima;
Revista Brasileira de Reumatologia , 2006, DOI: 10.1590/S0482-50042006000100004
Abstract: introduction: fibromyalgia can be defined as a non-inflammatory musculoskeletal pain syndrome. it is a chronic condition, commonly associated with fatigue and non-restorative sleep. however, such symptoms may result from coexisting diseases, for instance hypothyroidism. objective: based on this evidence, the aim of this study was to describe the concomitance of fibromyalgia in patients with hypothyroidism, the cases of hypothyroidism in patients diagnosed with fibromyalgia and determine the symptoms associated with above clinical conditions. methods: one hundred and sixty-six patients with fibromyalgia and 56 patients with hypothyroidism were evaluated. volunteer patients answered a questionnaire to detect the main signs and symptoms of these diseases and then underwent serum determination of thyroid stimulating hormone (tsh), free thyroxine (ft4) and anti-thyroperoxidase (a-tpo). results: among 166 patients with fibromyalgia, 35 (21.1%) were diagnosed with clinical or sub-clinical hypothyroidism. among 56 patients with hypothyroidism, 36 (64.3%) had the diagnosis of fibromyalgia confirmed, according to the american college of rheumatology's (acr) criteria. in patients with previously diagnosed hypothyroidism, fatigue, non-restorative sleep and chronic headache were symptoms statistically more frequent among those with the diagnosis of fibromyalgia. morning stiffness prevailed in patients diagnosed with hypothyroidism and without fibromyalgia. conclusion: we can concluded from this study that, in order to enhance the diagnostic approach and follow-up treatment, the presence of clinical or laboratorial manifestations of thyroid dysfunction in patients with fibromyalgia must be considered, as well as manifestations of fibromyalgia in patients with hypothyroidism.
La balanza de pagos tecnológicos de Galicia: entre la dependencia y la irrelevancia tecnológicas
Xavier Vence Deza,óscar Rodil Marzábal
Revista Galega de Economía , 2002,
Abstract: Se realiza una aproximación cuantitativa a la balanza de pagos tecnológicos de Galicia, recogiendo los pagos y los ingresos correspondientes a los flujos de tecnología no incorporada para los a os 1998 y 1999 a partir de una encuesta a las empresas. Los resultados revelan, tanto a nivel global como sectorial, un escaso volumen de flujos tecnológicos inmateriales y un elevado déficit en el comercio de conocimientos y servicios tecnológicos, confirmando la profunda dependencia de Galicia.
Dependence on Creativity Characteristics as Observed during the Implementation of Laboratory Activities  [PDF]
Lilia Ellany Mohtar, Lilia Halim, Seth Sulaiman
Creative Education (CE) , 2015, DOI: 10.4236/ce.2015.611115
Abstract: A person’s creativity can be elicited through observations made upon his/her behaviour and personality characteristics which are in turn termed as creativity characteristics. Physics Practical Work (PPW) is a form of instruction which is intended to foster a creative culture in schools in which large numbers of students can be engaged in an environment where creativity flourishes. However, there are criticisms leveled against the effectiveness of PPW in developing creativity among students as indicated by the emergence of the creativity characteristics. Besides being involved in PPW as a requirement of the course SPN3231, 12 respondents of the study comprising final year undergraduate physics education students participated in a Physics Innovative Project (PIP) whereby they had to modify or devise an alternative method(s) for teaching physics topics which they had earlier conducted in PPW. Seven dominant creativity characteristics constructs were incorporated into a well-validated Structured Interview Checklist (27 items) and an Observation Checklist (37 items). All data were analysed using the Interactive Qualitative Analysis Model by Miles and Huberman (1994). Results of the study indicated that PIP fostered frequent emergence of creativity characteristics much better as compared to PPW.
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