Internal transitions of negatively charged magnetoexcitons in quantum dots

We report calculations of oscillator strengths for the far infrared absorption of light by the excitonic complexes Xn- (the excess charge, n, ranging from one to four) confined in quantum dots. The magnetic field is varied in an interval which corresponds to ``filling factors'' between 2 and 3/5. Electron-hole interaction effects are seen in the deviations of the peak positions from the Kohn lines, and in the spreading of the oscillator strengths over a few final states. Transition densities are used as an additional tool to characterize the absorption peaks.Comment: Presented as a poster in the Third Stig Lundqvist Conference on Advancing Frontiers of Condensed Matter Physics: Fundamental Interactions and Excitations in Confined Systems, Trieste, August 11 - 1

Time Scale Analysis of a Fluidized-Bed Catalytic Reactor Based on a Generalized Dynamic Model

A fluidized-bed reactor model is implemented to simulate a Maleic Anhydride (MA) reactor with special emphasis on its dynamic behaviour. The dynamic model is general enough that it can treat a wide range of catalytic systems, subject to mass and energy balances within the phases. The model represents multiple phases and regions (low-density phase, high-density phase, freeboard region) and can account for heat and mass axial and radial anisotropic dispersion, change in molar/volumetric flow due to reaction, temperature and pressure profiles, hydrodynamic regime variation, catalyst deactivation, energy options, and multiple membranes of various geometries for introduction/extraction of any compound. The model reduces, as special cases, to most fluidized bed reactor models reported in the literature, allowing the influence of simplifying assumptions to be investigated. Introduction of different assumptions for a MA fluidized-bed reactor of industrial scale reveal quite different predicted time scales for key dynamic phenomena inherent to the process. A mass transfer/reaction time scale was found to be close to the residence time of the gas molecules in the reactor. The heat transfer time scale is several orders of magnitude larger for the current system. This type of time-scale analysis may be a useful tool to identify the appropriate degree of sophistication to predict the dynamics of complex reacting systems

Hospital general con unidad cardiovascular en la ciudad de Ibagu?

60 p. Recurso Electr?nicoEl hospital general con unidad cardiovascular localizado en la zona de expansi?n dispuesta por el plan de ordenamiento territorial (POT), es un proyecto que minimiza la crisis de salud por medio de infraestructura y cuerpo m?dico en la ciudad o departamento. Es producto al d?ficit de equipamientos de salud en Ibagu? y su prioridad o enfoque en las afecciones cardiovasculares, ya que es la principal causa de muerte en el Tolima. Est? compuesto por un juego de cinco vol?menes articulados, que concentran siete niveles; cada volumen adopta una funci?n espec?fica, lo mismo para cada nivel, donde se organizan las unidades puntuales del hospital; dando como resultado espacial, 15 consultorios m?dicos, una unidad de imagenologia general y otra cardiaca, la unidad de laboratorios y terapia, estos ubicados en el segundo nivel; en el tercer piso opera la unidad de quir?fanos y salas de recuperaci?n, el cuarto nivel la unidad de cuidados intensivos y del quinto al s?ptimo, la unidad de hospitalizaci?n. Continuo al volumen principal se ubica el volumen de servicios complementarios, dirigido a la pedagog?a m?dica, ?reas de comercio y zonas de estar. La propuesta ampliar?a la cobertura de salud de la ciudad y departamental, mejorando la calidad de vida para una falencia vigente; adem?s genera grandes oportunidades de orden f?sico, social, econ?mico y ambiental para un sector de futuro desarrollo de Ibagu?.The general hospital with a cardiovascular unit located in the expansion zone provided by the Territorial Order Plan (TOP) is a project that minimizes the health crisis through the infrastructure and the medical staff in the city or department. The project is a product of the deficit of health facilities in Ibagu?, Tolima and its priority are cardiovascular diseases, since it is the main cause of death in the region. It is composed of a set of five articulated volumes, which concentrate seven levels; each volume adopts a specific function, each level as well, where the specific units of the hospital are organized. As a result, in the second floor there are 15 medical clinics, a general imaging unit, a cardiac unit, laboratory and therapy unit. While in the third, there are the surgeon and recovery rooms. In the fourth there is the intensive care unit, and from the fifth to seventh, the hospitalization unit. The unit of complementary services is located next to the main unit; it is focused on medical pedagogy, areas of commerce, and living areas. The proposal will enhance the health coverage in the city and the department, improving the life quality. In addition, it generates great opportunities of physical, social, economic, and environmental order for a sector of future development in Ibagu?. Key words: health, hospital, unit, cardiology

INVESTIGATION OF CHANGE OF VOLUMETRIC FLOW IN FLUIDIZED-BED REACTORS

Volumetric flow can change due to such factors as variation in the number of moles due to reaction, feed distribution, change of phase, membranes and changes in temperature and pressure. This change in volumetric flow was investigated by varying the fluidized-bed pressure in a two-dimensional steel column. Pressure was impulsively adjusted, showing large transient voids during the transitions after rapid growth of the existing bubbles. The effects of sudden depressurization as well as elevated pressure fluidization were also investigated

Riqueza, endemismo y conservación de los mamíferos de Colombia

We update the list of Colombian mammal species based upon a new revision of specimens in the major collections within and outside the country and a compilation of recent taxonomic changes of species present in the country. The result of these changes is a total of 492 native species, which represents a net increment of 62 species with respect to the previous list published in the year 2000, and this exceeds similar updates in other Neotropical countries. Although the level of knowledge differs greatly between groups, we provide some general indicators, as diversity on the level of orders, endemism, patterns of distribution, and conservation state. The greatest species richness occurs in the orders Chiroptera (198 spp.) and Rodentia (122 spp.), but there are 23 endemic species of rodents in contrast to only seven endemic bats. According to the nature and scale of the evaluations, between 39 (MAVDT) and 52 (IUCN) species of Colombian mammals are considered to be endangered. The major threats are still deforestation, hunting and illegal commerce

Phylogeny and systematics of the "Pronophila clade," with 2 new genera to resolve the formerly polyphyletic genus Pseudomaniola (Lepidoptera: Nymphalidae: Satyrinae)

Analysis of a target enrichment molecular dataset confirms the monophyly of the Neotropical montane butterfly group known as the Pronophila Westwood clade, 1 of 2 major lineages of the satyrine subtribe Pronophilina. The Pronophila clade comprises 18-20 recognized genera and some 125 species. Within this group, the genus Pseudomaniola Röber appears as paraphyletic, and is split here into 3 genera, Pseudomaniola sensu novum with 6 species, including 4 previously considered as subspecies of P. phaselis (Hewitson), the monobasic Fahraeusia Pyrcz n. gen. for Catargynnis asuba Thieme, n. comb., and Boyeriana Pyrcz, Espeland & Willmott n. gen., with 9 species. The adults of all 3 genera can be recognized by their wing color patterns, but the strongest synapomorphies are found in the genitalia, especially those of the male, supporting the above systematic de cisions. Notable differences are also found in scale organization and morphology. A divergence time analysis suggests that Fahraeusia diverged from Pseudomaniola + Boyeriana in the mid-Miocene, around 12 Mya, and the subsequent separation of the last 2 genera occurred at the start of the Pliocene at around 5 Mya

Deciphering the components of regional net ecosystem fluxes following a bottom-up approach for the Iberian Peninsula

Quantification of ecosystem carbon pools is a fundamental requirement for estimating carbon fluxes and for addressing the dynamics and responses of the terrestrial carbon cycle to environmental drivers. The initial estimates of carbon pools in terrestrial carbon cycle models often rely on the ecosystem steady state assumption, leading to initial equilibrium conditions. In this study, we investigate how trends and inter-annual variability of net ecosystem fluxes are affected by initial non-steady state conditions. Further, we examine how modeled ecosystem responses induced exclusively by the model drivers can be separated from the initial conditions. For this, the Carnegie-Ames-Stanford Approach (CASA) model is optimized at set of European eddy covariance sites, which support the parameterization of regional simulations of ecosystem fluxes for the Iberian Peninsula, between 1982 and 2006. <br><br> The presented analysis stands on a credible model performance for a set of sites, that represent generally well the plant functional types and selected descriptors of climate and phenology present in the Iberian region – except for a limited Northwestern area. The effects of initial conditions on inter-annual variability and on trends, results mostly from the recovery of pools to equilibrium conditions; which control most of the inter-annual variability (IAV) and both the magnitude and sign of most of the trends. However, by removing the time series of pure model recovery from the time series of the overall fluxes, we are able to retrieve estimates of inter-annual variability and trends in net ecosystem fluxes that are quasi-independent from the initial conditions. This approach reduced the sensitivity of the net fluxes to initial conditions from 47% and 174% to −3% and 7%, for strong initial sink and source conditions, respectively. <br><br> With the aim to identify and improve understanding of the component fluxes that drive the observed trends, the net ecosystem production (NEP) trends are decomposed into net primary production (NPP) and heterotrophic respiration (<i>R</i><sub>H</sub>) trends. The majority (~97%) of the positive trends in NEP is observed in regions where both NPP and <i>R</i><sub>H</sub> fluxes show significant increases, although the magnitude of NPP trends is higher. Analogously, ~83% of the negative trends in NEP are also associated with negative trends in NPP. The spatial patterns of NPP trends are mainly explained by the trends in <i>f</i>APAR (<i>r</i>=0.79) and are only marginally explained by trends in temperature and water stress scalars (<i>r</i>=0.10 and <i>r</i>=0.25, respectively). Further, we observe the significant role of substrate availability (<i>r</i>=0.25) and temperature (<i>r</i>=0.23) in explaining the spatial patterns of trends in <i>R</i><sub>H</sub>. These results highlight the role of primary production in driving ecosystem fluxes. <br><br> Overall, our study illustrates an approach for removing the confounding effects of initial conditions and emphasizes the need to decompose the ecosystem fluxes into its components and drivers for more mechanistic interpretations of modeling results. We expect that our results are not only specific for the CASA model since it incorporates concepts of ecosystem functioning and modeling assumptions common to biogeochemical models. A direct implication of these results is the ability of this approach to detect climate and phenology induced trends regardless of the initial conditions