Necesidades académicas, personales, sociales y vocacionales de estudiantes internacionales e intercambio en la Universidad de Puerto Rico, Recinto de Río Piedras

Recibido 20 de setiembre de 2011 • Aceptado 24 de octubre de 2011 • Corregido 14 de noviembre de 2011   El propósito de este estudio fue identificar las necesidades de una muestra de estudiantes internacionales y de intercambio que cursan estudios en la Universidad de Puerto Rico, Recinto de Río Piedras. Se exploraron datos socio-demográficos así como las necesidades académicas, vocacionales, y personales/sociales, con los fines de recopilar información de relevancia para universidades que sirven esta población y someter recomendaciones que atiendan las necesidades. Los hallazgos revelaron necesidades mayormente en las áreas académicas y vocacionales. Entre estas, se destacan la necesidad de aprender inglés o español, y el conocer sobre internados y ofrecimientos académicos en Puerto Rico y fuera del país, sueldo y oportunidades de empleo, ayudas económicas y servicios estudiantiles en la Universidad de Puerto Rico. Se proveen recomendaciones para trabajar con las necesidades identificadas ya que, según establece la bibliografía, las dificultades que confrontan estos/as estudiantes pueden afectar su desempeño académico e incluso su salud emocional.

Canopy-scale biophysical controls of transpiration and evaporation in the Amazon Basin.

Canopy and aerodynamic conductances (gC and gA) are two of the key land surface biophysical variables that control the land surface response of land surface schemes in climate models. Their representation is crucial for predicting transpiration (λET) and evaporation (λEE) flux components of the terrestrial latent heat flux (λE), which has important implications for global climate change and water resource management. By physical integration of radiometric surface temperature (TR) into an integrated framework of the Penman?Monteith and Shuttleworth?Wallace models, we present a novel approach to directly quantify the canopy-scale biophysical controls on λET and λEE over multiple plant functional types (PFTs) in the Amazon Basin. Combining data from six LBA (Large-scale Biosphere-Atmosphere Experiment in Amazonia) eddy covariance tower sites and a TR-driven physically based modeling approach, we identified the canopy-scale feedback-response mechanism between gC, λET, and atmospheric vapor pressure deficit (DA), without using any leaf-scale empirical parameterizations for the modeling. The TR-based model shows minor biophysical control on λET during the wet (rainy) seasons where λET becomes predominantly radiation driven and net radiation (RN) determines 75 to 80 % of the variances of λET. However, biophysical control on λET is dramatically increased during the dry seasons, and particularly the 2005 drought year, explaining 50 to 65 % of the variances of λET, and indicates λET to be substantially soil moisture driven during the rainfall deficit phase. Despite substantial differences in gA between forests and pastures, very similar canopy?atmosphere "coupling" was found in these two biomes due to soil moisture-induced decrease in gC in the pasture. This revealed the pragmatic aspect of the TR-driven model behavior that exhibits a high sensitivity of gC to per unit change in wetness as opposed to gA that is marginally sensitive to surface wetness variability. Our results reveal the occurrence of a significant hysteresis between λET and gC during the dry season for the pasture sites, which is attributed to relatively low soil water availability as compared to the rainforests, likely due to differences in rooting depth between the two systems. Evaporation was significantly influenced by gA for all the PFTs and across all wetness conditions. Our analytical framework logically captures the responses of gC and gA to changes in atmospheric radiation, DA, and surface radiometric temperature, and thus appears to be promising for the improvement of existing land?surface?atmosphere exchange parameterizations across a range of spatial scales.

Canopy-scale biophysical controls of transpiration and evaporation in the Amazon Basin.

Canopy and aerodynamic conductances (gC and gA) are two of the key land surface biophysical variables that control the land surface response of land surface schemes in climate models. Their representation is crucial for predicting transpiration (?ET) and evaporation (?EE) flux components of the terrestrial latent heat flux (?E), which has important implications for global climate change and water resource management. By physical integration of radiometric surface temperature (TR) into an integrated framework of the Penman?Monteith and Shuttleworth?Wallace models, we present a novel approach to directly quantify the canopy-scale biophysical controls on ?ET and ?EE over multiple plant functional types (PFTs) in the Amazon Basin. Combining data from six LBA (Large-scale Biosphere-Atmosphere Experiment in Amazonia) eddy covariance tower sites and a TR-driven physically based modeling approach, we identified the canopy-scale feedback-response mechanism between gC, ?ET, and atmospheric vapor pressure deficit (DA), without using any leaf-scale empirical parameterizations for the modeling. The TR-based model shows minor biophysical control on ?ET during the wet (rainy) seasons where ?ET becomes predominantly radiation driven and net radiation (RN) determines 75 to 80?% of the variances of ?ET. However, biophysical control on ?ET is dramatically increased during the dry seasons, and particularly the 2005 drought year, explaining 50 to 65?% of the variances of ?ET, and indicates ?ET to be substantially soil moisture driven during the rainfall deficit phase. Despite substantial differences in gA between forests and pastures, very similar canopy?atmosphere "coupling" was found in these two biomes due to soil moisture-induced decrease in gC in the pasture. This revealed the pragmatic aspect of the TR-driven model behavior that exhibits a high sensitivity of gC to per unit change in wetness as opposed to gA that is marginally sensitive to surface wetness variability. Our results reveal the occurrence of a significant hysteresis between ?ET and gC during the dry season for the pasture sites, which is attributed to relatively low soil water availability as compared to the rainforests, likely due to differences in rooting depth between the two systems. Evaporation was significantly influenced by gA for all the PFTs and across all wetness conditions. Our analytical framework logically captures the responses of gC and gA to changes in atmospheric radiation, DA, and surface radiometric temperature, and thus appears to be promising for the improvement of existing land?surface?atmosphere exchange parameterizations across a range of spatial scales.

Arricchimento semantico nel contesto dell'Existing Building Information Modelling: aspetti metodologici e applicazione al caso della Rocca Estense di San Felice sul Panaro.

(ITA) L’industria mondiale odierna nel campo dell’architettura e dell’ingegneria si esprime quasi esclusivamente mediante l’approccio BIM, Building Information Modeling. Anche se sviluppato pensando alle nuove costruzioni ed ancora in via di perfezionamento, è entrato prepotentemente nei capitoli normativi di molti stati all’urlo dell“interoperability”. Su questo tema è recente l’interesse e la possibilità di adozione per l’intervento sul costruito, ovvero di Existing Building Information Modelling, eBIM. Gli studi applicativi-sperimentali in questo ambito sono sempre più numerosi e convergono, purtroppo, sulla delicata correlazione tra la gestione del contenuto semantico e la perdita di interoperabilità. Questa tesi si incentra sull’analisi di tale correlazione valutando in particolare l’aspetto metodologico-applicativo dell’arricchimento semantico adottando come caso studio la Torre Nord della Rocca Estense di San Felice sul Panaro. (ENG)Today's global industry in architecture and engineering fields, expresses itself almost entirely focusing on BIM, Building Information Modeling. Even though it was developed taking in consideration new buildings and the ones that are in the process of improvement, it has entered the regulatory chapters of many states in the hymn of "interoperability". Concerning this topic is recent the interest and possibility of adopting a process to intervene on the already built constructions, Existing Building Information Modeling, eBIM. Application-experimental studies in this area are increasingly numerous and unfortunately converge, on the delicate correlation between the management of the semantic content and the loss of interoperability. This thesis focuses on the analysis of this correlation by evaluating in particular the methodological-applicative aspect of semantic enrichment by adopting the North Tower of the Rocca Estense in San Felice sul Panaro as a case study.

Fatigue Design Challenges of Transition Pieces from Decommissioned Platforms for Offshore Wind Energy

All structures are subjected to various loading conditions and combinations. For offshore structures, these loads include permanent loads, hydrostatic pressure, wave, current, and wind loads. Typically, sea environments in different geographical regions are characterized by the 100-year wave height, surface currents, and velocity speeds. The main problems associated with the commonly used, deterministic method is the fact that not all waves have the same period, and that the actual stochastic nature of the marine environment is not taken into account. Offshore steel structure fatigue design is done using the DNVGL-RP-0005:2016 standard which takes precedence over the DNV-RP-C203 standard (2012). Fatigue analysis is necessary for oil and gas producing offshore steel structures which were first constructed in the Gulf of Mexico North Sea (the 1930s) and later in the North Sea (1960s). Fatigue strength is commonly described by S-N curves which have been obtained by laboratory experiments. The rapid development of the Offshore wind industry has caused the exploration into deeper ocean areas and the adoption of new support structural concepts such as full lattice tower systems amongst others. The optimal design of offshore wind support structures including foundation, turbine towers, and transition piece components putting into consideration, economy, safety, and even the environment is a critical challenge. In this study, fatigue design challenges of transition pieces from decommissioned platforms for offshore wind energy are proposed to be discussed. The fatigue resistance of the material and structural components under uniaxial and multiaxial loading is introduced with the new fatigue design rules whilst considering the combination of global and local modeling using finite element analysis software programs.