Stable Quantum Resonances in Atom Optics

A theory for stabilization of quantum resonances by a mechanism similar to one leading to classical resonances in nonlinear systems is presented. It explains recent surprising experimental results, obtained for cold Cesium atoms when driven in the presence of gravity, and leads to further predictions. The theory makes use of invariance properties of the system, that are similar to those of solids, allowing for separation into independent kicked rotor problems. The analysis relies on a fictitious classical limit where the small parameter is {\em not} Planck's constant, but rather the detuning from the frequency that is resonant in absence of gravity.Comment: 5 pages, 3 figure

How to detect a possible correlation from the information of a sub-system in quantum mechanical systems

A possibility to detect correlations between two quantum mechanical systems only from the information of a subsystem is investigated. For generic cases, we prove that there exist correlations between two quantum systems if the time-derivative of the reduced purity is not zero. Therefore, an experimentalist can conclude non-zero correlations between his/her system and some environment if he/she finds the time-derivative of the reduced purity is not zero. A quantitative estimation of a time-derivative of the reduced purity with respect to correlations is also given. This clarifies the role of correlations in the mechanism of decoherence in open quantum systems.Comment: 7 pages, 1 figur

Polymer electrolyte membranes and process for the production thereof

The process for the production of a polymer electrolyte membrane, comprises the successive steps of: preparing a mixed solution of a Room Temperature Ionic Liquid (RTIL), at least one alkaline metal salt and a photosensitive hydrogen abstracting component at a temperature in the range 20 to 70 °C, wherein the RTIL is a compound consisting of at least one organic cation and at least one organic or inorganic anion; adding to the solution a polymeric material at a temperature in the range of 20-70 °C; blending the solution added with the polymeric material at a temperature in the range of 70-140 °C to get a uniform mixture; pressing the mixture between two sheets at a temperature in the range of 60 - 150 °C and a pressure in the range of 20 - 80 bar, so that a film is formed; and exposing the film to UV light, so that the polymeric material of the film is cross-linked and the polymer electrolyte membrane is obtained

Preliminary study of illumination levels in university and elementary classrooms in Campina Grande, Brazil

The purpose of our study was to provide preliminary data on light levels used in university and elementary school classrooms in Campina Grande, Brazil with the aim of providing Brazilian politicians and educators with data to support continued educational initiatives in northeast Brazil. The data were gathered at the Universidade Federal de Campina Grande (UFCG) and compared with a sample of classrooms at Oklahoma State University (OSU) in Stillwater Oklahoma. The results indicated that many seats within UFCG classrooms met or exceeded minimum standards but significant numbers did not. Moreover, compared to classrooms at OSU, UFCG classrooms are not as highly illuminated and the Brazilian elementary classrooms examined did not meet minimum illumination standards.Peer reviewedPsychologyZoolog

Resonant Lifetime of Core-Excited Organic Adsorbates from First Principles

We investigate by first-principles simulations the resonant electron-transfer lifetime from the excited state of an organic adsorbate to a semiconductor surface, namely isonicotinic acid on rutile TiO$_2$(110). The molecule-substrate interaction is described using density functional theory, while the effect of a truly semi-infinite substrate is taken into account by Green's function techniques. Excitonic effects due to the presence of core-excited atoms in the molecule are shown to be instrumental to understand the electron-transfer times measured using the so-called core-hole-clock technique. In particular, for the isonicotinic acid on TiO$_2$(110), we find that the charge injection from the LUMO is quenched since this state lies within the substrate band gap. We compute the resonant charge-transfer times from LUMO+1 and LUMO+2, and systematically investigate the dependence of the elastic lifetimes of these states on the alignment among adsorbate and substrate states.Comment: 24 pages, 6 figures, to appear in Journal of Physical Chemistry

Enamel Formation Genes Influence Enamel Microhardness Before and After Cariogenic Challenge

There is evidence for a genetic component in caries susceptibility, and studies in humans have suggested that variation in enamel formation genes may contribute to caries. For the present study, we used DNA samples collected from 1,831 individuals from various population data sets. Single nucleotide polymorphism markers were genotyped in selected genes (ameloblastin, amelogenin, enamelin, tuftelin, and tuftelin interacting protein 11) that influence enamel formation. Allele and genotype frequencies were compared between groups with distinct caries experience. Associations with caries experience can be detected but they are not necessarily replicated in all population groups and the most expressive results was for a marker in AMELX (p = 0.0007). To help interpret these results, we evaluated if enamel microhardness changes under simulated cariogenic challenges are associated with genetic variations in these same genes. After creating an artificial caries lesion, associations could be seen between genetic variation in TUFT1 (p = 0.006) and TUIP11 (p = 0.0006) with enamel microhardness. Our results suggest that the influence of genetic variation of enamel formation genes may influence the dynamic interactions between the enamel surface and the oral cavity. © 2012 Shimizu et al

Trade openness, real exchange rates and job reallocation

This paper investigates the impact of real exchange rate movements on job reallocation at the industry level. The analysis focuses on the manufacturing sector of Belgium, using data for 82 NACE 3-digit industries, over the time span 1996-2002. I find that real exchange rate changes do have a significant impact on job flows, and that this impact is magnified by increasing levels of trade exposure. In particular, a real appreciation is found to lower net employment growth through higher job destruction, while job creation is not significantly affected. These results are in line with previous empirical evidence on the United States, and differ from earlier findings for France and Germany, where the adjustment to real exchange rate shocks has been found to occur mainly through the job creation margin. I suggest that these differences may be explained by the fact that Belgium is a small open economy

Quantum resonances and decoherence for delta-kicked atoms

The quantum resonances occurring with delta-kicked atoms when the kicking period is an integer multiple of the half-Talbot time are analyzed in detail. Exact results about the momentum distribution at exact resonance are established, both in the case of totally coherent dynamics and in the case when decoherence is induced by Spontaneous Emission. A description of the dynamics when the kicking period is close to, but not exactly at resonance, is derived by means of a quasi-classical approximation where the detuning from exact resonance plays the role of the Planck constant. In this way scaling laws describing the shape of the resonant peaks are obtained. Such analytical results are supported by extensive numerical simulations, and explain some recent surprising experimental observations.Comment: 51 pages, 13 figures; KEYWORDS: quantum chaos, decoherence, kicked rotor, dynamical localization, atom optics; submitted to Nonlinearit

An Investigation of Nurses' Knowledge, Attitudes, and Practices Regarding Disinfection Procedures in Italy

<p>Abstract</p> <p>Background</p> <p>This study assessed the level of knowledge, attitudes, and practice regarding disinfection procedures among nurses in Italian hospitals.</p> <p>Methods</p> <p>A face-to-face interview gathered the following information: demographic and practice characteristics; knowledge about the healthcare-associated infections (HAIs) and the disinfection practices; attitudes towards the utility of guidelines/protocols and perception of the risks of acquiring/transmitting HAIs; compliance with antisepsis/disinfection procedures; and sources of information.</p> <p>Results</p> <p>Only 29% acknowledged that urinary and respiratory tract infections were the two most common HAIs and this knowledge was significantly higher in those with a higher level of education. Attitudes towards the utility of guidelines/protocols for disinfection procedures showed a mean score of 9.1. The results of the linear regression model indicated a more positive attitude in female nurses, in those with a lower number of years of activity, and in those needing additional information about disinfection procedures. Nurses with higher educational level and with a higher perception of risk of transmitting an infectious disease while working were more likely to perform appropriate antisepsis of the surgical wound and handwashing before and after medication.</p> <p>Conclusions</p> <p>Plan of successful prevention activities about HAIs and provide pointers to help optimize disinfection procedures and infection prophylaxis and management are needed.</p