80 research outputs found
Compaction of microporous amorphous solid water by ion irradiation
We have studied the compaction of vapor-deposited amorphous solid water by energetic ions at 40 K. The porosity was characterized by ultraviolet-visible spectroscopy, infrared spectroscopy, and methane adsorption/desorption. These three techniques provide different and complementary views of the structural changes in ice resulting from irradiation. We find that the decrease in internal surface area of the pores, signaled by infrared absorption by dangling bonds, precedes the decrease in the pore volume during irradiation. Our results imply that impacts from cosmic rays can cause compaction in the icy mantles of the interstellar grains, which can explain the absence of dangling bond features in the infrared spectrum of molecular clouds.Fil: Raut, U.. University of Virginia; Estados UnidosFil: Teolis, B. D.. University of Virginia; Estados UnidosFil: Loeffler, M. J.. University of Virginia; Estados UnidosFil: Vidal, Ricardo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Famá, M.. University of Virginia; Estados UnidosFil: Baragiola, R. A.. University of Virginia; Estados Unido
Metereological conditions and psychiatric emergency visits in Messina, Italy
Objective: The aim of this study is to examine the association between psychiatric disease, climatic and seasonal factors in patients recorded to the Emergency Unit, in Messina Hospital (Italy). Method: A total of 6565 psychiatric patients were recorded to the Emergency Unit in Messina from January 2005 and December 2010. Each psychiatric visit in emergency, was categorized by date of appearance and admitting diagnosis according to diagnostic categories: Anxiety, Mood Disorders and Psychosis. Local weather data were obtained from the Metereological Instituted "Aereonautica Militare" station in Messina, Sicily, In addition, to gathering data on the state of the sky, temperature, atmosphericpressure with the normalized value at sea level, relative humidity, rainfall, wind direction and speed, the station is connected to a buoy located on the eastern sector of Tyrrhenian Sea. Results: In anxiety disorders we have found relevant results comparison between winter and spring (p=.007) and spring and fall (p=.001). In affective disorders the differences occur in relation to winter and fall (p=.002), spring and fall (p=001), spring and summer (p=002). The psychotic disorder presents significant differences between summer and fall (p=.001) and spring and fall (p=.002). Conclusions: We can observe a similarity of affective disorders, i.e. anxiety and mood disorders compared to psychosis, which have different influences and probably according to dissimilar etiopathogenetic ways. In our research, the distribution of anxiety disorders is higher than depressive disorders in terms of delivering emergency room visits. The major differences occur comparing spring and fall, the seasons when all pathological classes have significant differences. It follows that the most abrupt climate change, typical of these seasons, as a whole, cause psychopathological emergencies. The study is important for planning a more effective assistance for patients needing psychiatric support
Radiolysis of water ice in the outer solar system: Sputtering and trapping of radiation products
We performed quantitative laboratory radiolysis experiments on cubic water ice between 40 and 120 K, with 200 keV protons. We measured sputtering of atoms and molecules and the trapping of radiolytic molecular species. The experiments were done at fluences corresponding to exposure of the surface of the Jovian icy satellites to their radiation environment up to thousands of years. During irradiation, O2 molecules are ejected from the ice at a rate that grows roughly exponentially with temperature; this behavior is the main reason for the temperature dependence of the total sputtering yield. O2 trapped in the ice is thermally released from the ice upon warming; the desorbed flux starts at the irradiation temperature and increases strongly above 120 K. Several peaks in the desorption spectrum, which depend on irradiation temperature, point to a complex distribution of trapping sites in the ice matrix. The yield of O2 produced by the 200 keV protons and trapped in the ice is more than 2 orders of magnitude smaller than used in recent models of Ganymede. We also found small amounts of trapped H2O2 that desorb readily above 160 K.Fil: Bahr, D.A.. University of Virginia; Estados UnidosFil: Famá, M.. University of Virginia; Estados UnidosFil: Vidal, Ricardo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Baragiola, Raul Antonio. University of Virginia; Estados Unido
Recent advances and perspectives on starch nanocomposites for packaging applications
Starch nanocomposites are popular and abundant materials in packaging sectors. The aim of this work is to review some of the most popular starch nanocomposite systems that have been used nowadays. Due to a wide range of applicable reinforcements, nanocomposite systems are investigated based on nanofiller type such as nanoclays, polysaccharides and carbonaceous nanofillers. Furthermore, the structures of starch and material preparation methods for their nanocomposites are also mentioned in this review. It is clearly presented that mechanical, thermal and barrier properties of plasticised starch can be improved with well-dispersed nanofillers in starch nanocomposites
Status of QUBIC, the Q&U Bolometer for Cosmology
The Q&U Bolometric Interferometer for Cosmology (QUBIC) is a novel kind of
polarimeter optimized for the measurement of the B-mode polarization of the
Cosmic Microwave Back-ground (CMB), which is one of the major challenges of
observational cosmology. The signal is expected to be of the order of a few
tens of nK, prone to instrumental systematic effects and polluted by various
astrophysical foregrounds which can only be controlled through multichroic
observations. QUBIC is designed to address these observational issues with a
novel approach that combines the advantages of interferometry in terms of
control of instrumental systematics with those of bolometric detectors in terms
of wide-band, background-limited sensitivity.Comment: Contribution to the 2022 Cosmology session of the 33rd Rencontres de
Blois. arXiv admin note: substantial text overlap with arXiv:2203.0894
Biodegradable foams based on starch, polyvinyl alcohol, chitosan and sugarcane fibers obtained by extrusion
Concentração de propriedade e desempenho: um estudo nas empresas brasileiras de capital aberto do setor de energia elétrica
Effect of incorporation of nutraceutical capsule waste of safflower oil in the mechanical characteristics of corn starch films
An analysis of the deinstitutionalization of inflation-adjusted accounting practices in Brazilian companies
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