97 research outputs found
Formalism for obtaining nuclear momentum distributions by the Deep Inelastic Neutron Scattering technique
We present a new formalism to obtain momentum distributions in condensed
matter from Neutron Compton Profiles measured by the Deep Inelastic Neutron
Scattering technique. The formalism describes exactly the Neutron Compton
Profiles as an integral in the momentum variable . As a result we obtain a
Volterra equation of the first kind that relates the experimentally measured
magnitude with the momentum distributions of the nuclei in the sample. The
integration kernel is related with the incident neutron spectrum, the total
cross section of the filter analyzer and the detectors efficiency function. A
comparison of the present formalism with the customarily employed approximation
based on a convolution of the momentum distribution with a resolution function
is presented. We describe the inaccuracies that the use of this approximation
produces, and propose a new data treatment procedure based on the present
formalism.Comment: 11 pages, 8 figure
A discrete boundary value problem in Banach spaces
In this paper we present existence theorems for the second order discrete boundary problem in Banach spaces under weaker conditions we have known. We suppose the weak sequential continuity and some conditions expressed in terms of the measure of the weak noncompactness
Static structure factor of liquid parahydrogen
7 págs.; 5 figs. ; PACS number~s!: 61.20.2p, 61.12.2q, 78.70.2gThe single-differential neutron-scattering cross section of liquid parahydrogen has been measured at 15.2 K and 2 bars of applied pressure by means of low-energy neutron diffraction. Our experimental conditions enable the direct observation of the peak of the liquid structure factor and therefore largely improve the signal-to-noise ratio with respect to measurements carried out using higher-energy neutron diffraction. This avoids the need of performing corrections of approximate nature to the measured cross section that is dominated by molecular rotational components if measured by conventional neutron diffraction. ©2004 American Physical SocietyPeer Reviewe
Development of novel PEX5-PEX14 protein-protein interaction (PPI) inhibitors based on an oxopiperazine template
Protein-protein interactions (PPIs) constitute an important but challenging class of molecular targets for small molecules. The PEX5-PEX14 PPI has been shown to play a critical role in glycosome biogenesis and its disruption impairs the metabolism in Trpanosoma parasites, eventually leading to their death. Therefore, this PPI is a potential molecular target for new drugs against diseases caused by Trypanosoma infections. Here, we report a new class of peptidomimetic scaffolds to target the PEX5-PEX14 PPI. The molecular design was based on an oxopiperazine template for the α-helical mimetics. A structural simplification along with modifications of the central oxopiperazine scaffold and addressing the lipophilic interactions led to the development of peptidomimetics that inhibit PEX5-TbPEX14 PPI and display cellular activity against T. b. brucei. This approach provides an alternative approach towards the development of trypanocidal agents and may be generally useful for the design of helical mimetics as PPI inhibitors
The effect of AgroSupra S fertilization on yield and yield components of spring barley
Польовий експеримент з ярим ячменем проведено у 2014 р. Вивчено два такі варіанти: 0 – контроль, S – AgroSupra S (42 кг·S·га-1). Використання AgroSupry S як сірчаного добрива забезпечило збільшення врожаю зерна порівняно з контрольним варіантом. Збільшення врожайності залежить від маси 1000 зерен і, меншою мірою, від кількості зерен у колосі. Сульфат кальцію, зареєстрований офіційно як сірчано-кальцієве добриво AgroSupra S, має властивості хорошого добрива, подібні до інших сірчаних добрив.Field experiment with winter wheat was conducted in 2014. Two variants were compared: 0 – control, S – AgroSupra S (42 kg·S·ha-1). Application of AgroSupra S, as sulphur fertilizer caused significant increase of grain yield as compared with control variant. Yield increase was the effect of higher 1000 grains weight and in minor scale of number of grains per ear. Limestone sulfate officially registered as sulphur-calcium AgroSupra S fertilizer has good properties similar to other sulphur fertilizers
The Bariloche Neutron Physics Group Current Activities
Our group has evolved around a small accelerator-based neutron source (ABNS), the 25 million electron Volt (MeV) linear electron accelerator at the Bariloche Atomic Centre. It is dedicated to applications of neutronic methods to tackle problems of basic sciences and to technological applications. Among these, the determination of total cross section of a material as a function of neutron energy by means of transmission experiments for thermal and sub-thermal neutrons is very sensitive to the geometric arrangement and movement of the atoms, over distances ranging from the 'first-neighbour scale' up to the microstructural level or 'grain scale'. This also allowed to test theoretical models of calculated cross sections and scattering kernels. Interest has moved from pulsed neutron diffraction towards deep inelastic neutron scattering (DINS), a powerful tool for the determination of atomic momentum distribution in condensed matter and for non-destructive mass spectroscopy. In recent years non-intrusive techniques aimed at the scanning of large cargo containers have started to be developed with this ABNS, testing the capacity and limitations to detect special nuclear material and dangerous substances in thick cargo arrangements. More recently, the use of the ever-present “bremsstrahlung” radiation has been recognized as a useful complement to instrumental neutron activation, as it permits to detect other nuclear species through high-energy photon activation. The facility is also used for graduate and undergraduate students experimental work within the frame of Instituto Balseiro Physics and Nuclear Engineering courses of study, and also MSc and PhD theses work.Fil: Mayer, Roberto Edmundo. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: D'Amico, N. M. B.. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Granada, Jose Rolando. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Dawidowski, Javier. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Santisteban, Javier Roberto. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Blostein, Juan Jeronimo. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Tartaglione, Aureliano. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rodriguez Palomino, Luis Alberto. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Marquez Damian, Jose Ignacio. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sepúlveda Sosa, C.. Comision Chilena de Energia Nuclear; Chil
Epidemia de Gripe A en Buenos Aires en 2009 y la comunicación de la prevención colectiva
Objetivo: Analizar longitudinalmente la construcción de la participación social en la prevención de la gripe A en 2009, evaluando sincrónicamente discursos sobre prevención y evolución de la epidemia en clase media urbana de Buenos Aires. Métodos: Triangulación cuali-cuantitativa: 1) Evolución de enfermedad tipo Influenza en un Hospital de Comunidad que atiende clase media porteña; 2) Evolución de casos a nivel país; 3) Representación de la prevención en medios gráficos nacionales. Resultados: El brote epidémico en clase media porteña precedió al total país, período en el que el porcentaje en tapa de notas sobre gripe A era 3,9%. Las medidas que previenen colectivamente la difusión viral (higiene de manos, superficies y contención de estornudos) se comunicaron posteriormente al pico epidémico.
Conclusiones: La comunicación contribuyó a construir tardíamente la participación social. Esto evidencia la necesidad de promover la participación temprana de la sociedad en la prevención colectiva frente a riesgo epidémicos
Historical (1750 - 2014) anthropogenic emissions of reactive gases and aerosols from the Community Emission Data System (CEDS)
We present a new data set of annual historical (1750–2014) anthropogenic chemically reactive gases (CO, CH4, NH3, NOX, SO2, NMVOC), carbonaceous aerosols (BC and OC), and CO2 developed with the Community Emissions Database System (CEDS). We improve upon existing inventories with a more consistent and reproducible methodology applied to all emissions species, updated emission factors, and recent estimates through 2014. The data system relies on existing energy consumption data sets and regional and country-specific inventories to produce trends over recent decades. All emissions species are consistently estimated using the same activity data over all time periods. Emissions are provided on an annual basis at the level of country and sector and gridded with monthly seasonality. These estimates are comparable to, but generally slightly higher than, existing global inventories. Emissions over the most recent years are more uncertain, particularly in low- and middle-income regions where country-specific emission inventories are less available. Future work will involve refining and updating these emission estimates, estimating emissions uncertainty, and publication of the system as open source software
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