Search results for "Effect"
showing 10 items of 9072 documents
Effects of high pressure thermal treatments in oxygen and helium atmospheres on amorphous silicon dioxide and its radiation hardness
2009
The effects of thermal treatments at similar to 400 degrees C in oxygen or helium atmospheres at similar to 180 baron the radiation hardness of amorphous SiO(2) are studied. The generation efficiency of several point defects under gamma irradiation is compared to that of the untreated material. All the effects on point defects generation here observed can be explained in terms of changes in the precursor sites. In particular it has been observed that the thermal treatments can change the precursors sites of point defects both through temperature and pressure related processes, not depending on the atmosphere, and through oxygen related processes creating oxygen excess sites. The presence of…
In-situ observation of beta-ray induced UV optical absorption in a-SiO2: radiation darkening and room temperature recovery
2006
International audience; We studied the optical absorption in the 3.0-6.2 eV range induced in bulk amorphous SiO2 by beta-ray irradiation up to similar to 1 MGy at room temperature. The induced absorption was measured in situ both during irradiation and in the post irradiation time. Our data evidence E', center as the main defect induced by irradiation and the partial decay of their absorption band at about 5.8 eV after irradiation. A quantitative analysis of the time evolution of the induced absorption shows that the transmission recovery observed after irradiation is compatible with the reaction of radiation-induced defects with H-related (H-2, H2O) species diffusing in the amorphous matrix
Occupational Safety and Health
2012
Abstract Occupational health and safety reflects the effect of the work environment on employees, groups and work units in organizations, and organizations as a whole. This chapter provides an overview of the research on workplace safety and specifically discusses safety training, regulatory focus, safety climate, leadership, and job design as they relate to safety. Additionally, the literature on occupational health, drawing heavily on the occupational stress literature, discusses the employee-employer relationship from a psychological contract perspective, including climate for sexual harassment, collective burnout and its contagion, recovery, and organizational wellness programs. Particu…
Gaia -ESO Survey: Analysis of pre-main sequence stellar spectra
2015
This paper describes the analysis of UVES and GIRAFFE spectra acquired by the Gaia-ESO Public Spectroscopic Survey in the fields of young clusters whose population includes pre-main sequence (PMS) stars. Both methods that have been extensively used in the past and new ones developed in the contest of the Gaia-ESO survey enterprise are available and used. The internal precision of these quantities is estimated by inter-comparing the results obtained by such different methods, while the accuracy is estimated by comparison with independent external data, like effective temperature and surface gravity derived from angular diameter measurements, on a sample of benchmarks stars. Specific strategi…
Effect of short-chain alcohols on surfactant-mediated reversed-phase liquid chromatographic systems.
2010
The behaviour of β-blockers in a reversed-phase liquid chromatographic (RPLC) column with mobile phases containing a short-chain alcohol (methanol, ethanol or 1-propanol), with and without the surfactant sodium dodecyl sulphate (SDS), was explored. Two surfactant-mediated RPLC modes were studied, where the mobile phases contained either micelles or only surfactant monomers at high concentration. Acetonitrile was also considered for comparison purposes. A correlation was found between the effects of the organic solvent on micelle formation (monitored by the drop weight procedure) and on the nature of the chromatographic system (as revealed by the retention, elution strength and peak shape of…
Neuropeptide Y effects on pineal melatonin synthesis in the rat
1987
Neuropeptide Y (NPY)-like immunoreactivity is present in the rodent pineal gland. To elucidate possible effects on pineal melatonin synthesis NPY (5 nmol/kg body wt.) was injected into the common carotid artery of male rats. Activities of the melatonin biosynthetic enzymes, serotonin N-acetyltransferase (NAT) and hydroxyindole-O-methyltransferase (HIOMT) were determined by means of radioenzymatic methods. Intact light-exposed animal showed increased NAT activity at day- and at nighttime. Blinded animals showed a more than 10-fold reduction of NAT activity after nocturnal NPY injections. HIOMT activity was only slightly influenced at either time. These results are discussed in terms of the p…
Thermoelectric properties of CoTiSb based compounds
2009
Several CoTiSb based compounds were synthesized and investigated on their thermoelectric properties. The aim was to improve the thermoelectric properties of CoTiSb by the systematic substitution of atoms or the introduction of additional Co into the vacant sublattice. The solid solutions Co1+xTiSb, Co1?yCuyTiSb and CoTiSb1?zBiz were synthesized. X-ray diffraction was used to investigate the crystal structure. The resistivity, the Seebeck coefficient and the thermal conductivity were determined for all compounds in the temperature range from 2 to 400?K. The highest figure of merit for each solid solution is presented. We were able to improve the figure of merit by a factor of approximately s…
Synthesis and characterization of bi-functional photorefractive polymers
2001
Abstract A novel bi-functional photorefractive acrylate polymer with pendant carbazolyl groups and azo derivatives as side chains was synthesized, in which azo derivatives as electro-optic chromophores and carbazolyl as photoconductive moiety were covalently linked on the acrylate backbone. Photorefractive experiments showed that a high two-beam coupling gain coefficient of 93 cm −1 , diffraction efficiency of 12% and electro-optic coefficient of 26 pm/V were obtained. With increasing writing beam's intensity, the two-beam coupling enhanced gradually, and then reached saturation. Using the method of four-wave mixing, the photoisomerization grating was observed.
Organizational and activational effects of testosterone on risk-taking in economical behavior: A systematic review
2017
Resumen El objetivo de esta revisión sistemática es evaluar la influencia de la testosterona circulante (efectos activacionales) y de la exposición prenatal a ella (efectos organizacionales) sobre la asunción de riesgos en conductas económicas, evaluando los trabajos de investigación existentes hasta la fecha acerca de la temática. La base bibliográfica analizada se obtuvo de distintas bases de datos especializadas en el ámbito de la psicología y las neurociencias. Los resultados obtenidos concluyen en una relación contrastada entre la testosterona circulante y la asunción de riesgo financiero. En lo referente a la exposición prenatal se evidencia un estado inmaduro de la investigación sobr…
Generalized effective stress concept for saturated active clays
2021
Experimental evidence shows that changes in pore-water chemistry can significantly affect the mechanical behavior of saturated active clays. Despite this evidence, how the chemical composition of the pore water can be considered in effective stress definition is questionable. This paper develops the concept of generalized effective stress for active clays. To this end, physicochemical studies on water–clay mineral interactions are used to clearly define the different types of ions and water present in an active clay. In particular, the presence of both movable and non-movable ions within the liquid water is highlighted. Taking this into account, thermodynamic and geochemistry principles ar…