Estiolamento, incisão na base da estaca e uso do ácido indolbutírico na propagação da caramboleira por estacas lenhosas.

Objetivou-se, neste trabalho, avaliar o efeito do estiolamento, da incisão na base da estaca e do tratamento com ácidoindolbutírico (AIB) no enraizamento de estacas lenhosas de caramboleira. As estacas foram padronizadas com um par de folhasinteiras e 12 cm de comprimento

Diferentes substratos na produção de porta-enxertos de caramboleira.

Objetivou-se com o presente estudo verificar a influência de diferentes substratos na produção de porta-enxertos de caramboleira. As sementes foram extraídas de frutos maduros de carambola cultívar Malásía, lavadas em água corrente e semeadas em bandejas de poliestireno (72 células, capacidade de 120 cm3/célula), contendo os seguintes substratos: vermículita, Plantmax, Rendmax, terra de barranco, areia e terra + areia (1:1, 2:1 e 1:2 v/v). Em seguída, as bandejas foram colocadas em ambiente coberto por sombrite com 50 % de lurninosidade, efetuando-se regas manuais diárias. Após 130 dias da semeadura, foram coletados os seguintes dados biométricos: porcentagem de plantas vivas, altura das plântulas, comprimento das raízes e número de folhas. Concluiu-se que a mistura terra + areia (1:1 v/v) foi mais eficiente na germinação de sementes e formação inicial de porta-enxertos de caramboleira

Study and suppression of the microstructural anisotropy generated during the consolidation of a carbonyl iron powder by field-assisted hot pressing

Published OnlineA spherical carbonyl iron powder was consolidated by the field-assisted hot pressing technique using graphite tools at two different temperatures, both above the austenitizing temperature. The microstructures obtained exhibited a compositional gradient in carbon along the consolidated material. Thus, the outer rim of the cylindrical samples was composed of cementite and pearlite that gradually turned to pearlite, leading to a fully ferritic microstructure at the core of the sample. The increase in the temperature has led to a higher introduction of carbon within the sample. The interposition of a thin tungsten foil between the graphite die/punches and the powders has significantly reduced the diffusion of the carbon through the iron matrix and has suppressed the microstructural anisotropy.Publicad

Event-based causality in virtual reality

In this paper, we describe such an environment, in which the user can be presented in real-time with an alternative range of consequences for a given interaction with virtual world objects, thus inducing various perceptions of causality. From a systemic perspective, we can adopt a pragmatic approach, inspired from Humian philosophy, which considers that causal relations are established by the user in response to certain event co-occurrences. To control causal perception in VR, the system comprises the following components: a visualisation engine, an Event Recognition System (together with its specific event formalism that supports event modification), and a causal engine as an Event Modification System, which selects co-occurring events on a rule-based manner. A search process, evaluates alternative consequences using semantic and spatio-contiguity information, such as comparison between candidate objects on which the action consequences should be applied. A first prototype has been fully implemented and is described together with an example real-time simulation

INFLUENCE OF THE MODEL SIZE IN THE NUMERICAL DETERMINATION OF THE AVERAGE THERMAL STRESSES IN AN MMC COMPOSITE

In previous works the authors discussed some issues related to a specific metallic matrix composites (MMC), the Aluminum matrix reinforced with SiC particles (Al+SiC) which has a metal matrix (powder) mixed with ceramic particles. These materials have some advantages when used as a structural material such as their high strength and good conformability. Their properties depend, among others, on the volumetric ratio, the  particles size and distribution besides the matrix microstructure itself. Some of them are obtained at elevated temperature what produces a thermal stress state in the material. The Al+SiC is one of the later. The powder mix is extruded at 600oC and it is used at 20oC. Several numerical analyses were performed considering the random distribution of the particles and a non-linear behavior in the aluminum matrix. The results showed strong influence of the aluminum elastic-plastic behavior in the composite thermal stress distribution due to its manufacturing process. However, one issue remained: the size of the model. It represents the central portion of a Al+SiC bar which is only about 10 times the size of a single particle (~10L). The present work investigates, always numerically, the influence of the model size on the thermal stress distribution. It considers 2 sets of non-linear analyses with random distributed particles: one with 20 models with size of 20L each one, the other set with another 20 models with size 40L. This approach allows a view of the results tendency compared with the 10L ones. As done before, the modeled volumetric ratio has a very tight range of values with its average very near to the value in an actual Al+SiC composite. It is showed that the first model size was already enough to get good results without sacrificing neither the computer nor the analyst time

Type localities of cricetids in unknown lands: Jesematathla and Waikthlatingmayalwa in the Paraguayan Chaco

Jesematathla y Waikthlatingmayalwa son dos localidades típicas de roedores cricétidos emplazadas en el Chaco de Paraguay. En la primera fueron coleccionados los holotipos de Akodon toba y Oryzomys wavrini; en la segunda, Akodon lenguarum y Phyllotis chacoënsis. La ubicación geográfica exacta de estas localidades es aún discutida, aspecto que se intenta clarificar en esta nota. Los resultados obtenidos indican que ambas se emplazan en el Chaco Húmedo. Jesematathla se corresponde hoy día con la Estancia Yesamathasa. Waikthlatingmayalwa ha desaparecido como topónimo, en favor de Misión Central y solo debe conservarse a los fines históricos. Se discuten brevemente las implicaciones taxonómicas de estos hallazgos.Jesematathla and Waikthlatingmayalwa are two type localities of cricetid rodents from the Paraguayan Chaco. The holotypes of Akodon toba and Oryzomys wavrini were collected in the former; whereas, Akodon lenguarum and Phyllotis chacoënsis were obtained in the latter. The exact geographic location of both localities is controversial, and the goal of this note is to clarify the issue. We show that both localities are located in the Humid Chaco. Jesematathla corresponds today to the Estancia Yesamathasa. Waikthlatingmayalwa disappeared as a toponym, replaced by Misión Central and should be retained solely for historical purposes. The taxonomic implications of these findings are briefly discussed.Centro de Estudios Parasitológicos y de Vectore

Type localities of cricetids in unknown lands: Jesematathla and Waikthlatingmayalwa in the Paraguayan Chaco

Jesematathla y Waikthlatingmayalwa son dos localidades típicas de roedores cricétidos emplazadas en el Chaco de Paraguay. En la primera fueron coleccionados los holotipos de Akodon toba y Oryzomys wavrini; en la segunda, Akodon lenguarum y Phyllotis chacoënsis. La ubicación geográfica exacta de estas localidades es aún discutida, aspecto que se intenta clarificar en esta nota. Los resultados obtenidos indican que ambas se emplazan en el Chaco Húmedo. Jesematathla se corresponde hoy día con la Estancia Yesamathasa. Waikthlatingmayalwa ha desaparecido como topónimo, en favor de Misión Central y solo debe conservarse a los fines históricos. Se discuten brevemente las implicaciones taxonómicas de estos hallazgos.Jesematathla and Waikthlatingmayalwa are two type localities of cricetid rodents from the Paraguayan Chaco. The holotypes of Akodon toba and Oryzomys wavrini were collected in the former; whereas, Akodon lenguarum and Phyllotis chacoënsis were obtained in the latter. The exact geographic location of both localities is controversial, and the goal of this note is to clarify the issue. We show that both localities are located in the Humid Chaco. Jesematathla corresponds today to the Estancia Yesamathasa. Waikthlatingmayalwa disappeared as a toponym, replaced by Misión Central and should be retained solely for historical purposes. The taxonomic implications of these findings are briefly discussed.Centro de Estudios Parasitológicos y de Vectore

Type localities of cricetids in unknown lands: Jesematathla and waikthlatingmayalwa in the Paraguayan Chaco

Jesematathla y Waikthlatingmayalwa son dos localidades típicas de roedores cricétidos emplazadas en el Chaco de Paraguay. En la primera fueron coleccionados los holotipos de Akodon toba y Oryzomys wavrini; en la segunda, Akodon lenguarum y Phyllotis chacoënsis. La ubicación geográfica exacta de estas localidades es aún discutida, aspecto que se intenta clarificar en esta nota. Los resultados obtenidos indican que ambas se emplazan en el Chaco Húmedo. Jesematathla se corresponde hoy día con la Estancia Yesamathasa. Waikthlatingmayalwa ha desaparecido como topónimo, en favor de Misión Central y solo debe conservarse a los fines históricos. Se discuten brevemente las implicaciones taxonómicas de estos hallazgos.Jesematathla and Waikthlatingmayalwa are two type localities of cricetid rodents from the Paraguayan Chaco. The holotypes of Akodon toba and Oryzomys wavrini were collected in the former; whereas, Akodon lenguarum and Phyllotis chacoënsis were obtained in the latter. The exact geographic location of both localities is controversial, and the goal of this note is to clarify the issue. We show that both localities are located in the Humid Chaco. Jesematathla corresponds today to the Estancia Yesamathasa. Waikthlatingmayalwa disappeared as a toponym, replaced by Misión Central and should be retained solely for historical purposes. The taxonomic implications of these findings are briefly discussed.Fil: Pardiñas, Ulises Francisco J.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; ArgentinaFil: Simoes Libardi, Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; ArgentinaFil: Galliari, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; Argentin

Estudo de parâmetros físicos, químicos e hídricos de um latossolo amarelo, na região amazônica.

O presente estudo objetiva caracterizar informações sobre atributos físicos, químicos e, principalmente, hídricos de um perfil de solo sob um sistema agroflorestal com o intuito de contribuir para o conhecimento básico e uso racional das terras amazônicas