Search results for "absorptio"
showing 10 items of 2815 documents
Evaluation of Antimony, Cadmium and Lead Levels in Vegetables, Drinking and Raw Water from Different Agricultural Areas
1990
Abstract Lead and cadmium levels in edible vegetables and antimony, lead and cadmium in drinking and raw waters from three agricultural areas exposed to different levels of environmental pollution (1-high industrial pollution, 2-high urban pollution, 3-standard low industrial and urban pollution) are determined. The organic matter is destroyed by repeated attack with nitric acid. Cadmium and lead are determined by graphite furnace atomic absorption spectrometry (GFAAS) and antimony by hydride generation atomic absorption spectrometry (HGAAS). When the results obtained for three different areas are compared, differences between cadmium and lead contents in vegetables are observed. Waters are…
Quantification of cadmium-induced metallothionein in crustaceans by the silver-saturation method
1995
Metallothionein (MT) has been proposed as a specific biochemical probe for metal exposure of aquatic organisms. It is recognized that its usefulness as a monitoring tool depends on the full understanding of its function and on the possibility of measuring its concentration in tissues. Therefore the study of MT in crustaceans is interesting from two different points of view: the need to understand mechanisms associated with the toxicology of metals, and the potential use of this protein for monitoring metal-contamined environments. Several methods have been developed for quantitative measurements of MT in biological samples. Immunochemical and electrochemical procedures are reliable techniqu…
A surface EXAFS study of thin nickel deposits on (110) TiO2 surfaces
1997
Abstract The first stages of nickel deposition on a clean (110) TiO 2 surface were studied using surface extended X-ray absorption fine structure (EXAFS). Experiments were performed on two kinds of nickel deposits, one of 0.8 equivalent monolayers and another of 1.6 equivalent monolayers. Depositions were performed on well characterized TiO 2 (110)-p(1 × 1) surfaces. The correlation of Auger experiments with EXAFS results showed that no islands were present on the surface; only two-dimensional growth of nickel was observed. Moreover, it was shown, in the case of the thinner deposit, that a model with nickel atoms forming chains in the channels determined by oxygen atoms on the surface is co…
Electrostatic phenomena in ion exchange membranes
1971
Abstract Specific and transport properties of a cation and an anion exchange membrane in Na + and Cl - form respectively have been measured in water and dioxane water mixtures. A greater electrolyte absorption and a lesser specific conductivity and counterion transport number in solvents at higher dioxane content indicate strong electrostatic interactions between fixed groups in the membrane and counterions.
Measurement of the low-energy antideuteron inelastic cross section
2020
In this Letter, we report the first measurement of the inelastic cross section for antideuteron-nucleus interactions at low particle momenta, covering a range of $0.3 \leq p < 4$ GeV/$c$. The measurement is carried out using p-Pb collisions at a center-of-mass energy per nucleon-nucleon pair of $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV, recorded with the ALICE detector at the CERN LHC and utilizing the detector material as an absorber for antideuterons and antiprotons. The extracted raw primary antiparticle-to-particle ratios are compared to the results from detailed ALICE simulations based on the GEANT4 toolkit for the propagation of antiparticles through the detector material. The analysis of th…
Research data supporting 'Short hydrogen bonds enhance nonaromatic protein-related fluorescence'
2021
Raw data for experimental figures. Files contain .cif (crystallographic information file) for XRD data of the L-pyro-amm structure. .xlsx file containing spectra for absorption of L-glutamine, L-pyroglutamine and L-pyro-amm. .xlsx file contains spectra for fluorescence excitation and emission collected over 8 days for L-glutamine conversion to L-pyro-amm.
Optical transitions associated with non bridging oxygen hole centers in irradiated silica
2005
The Photocycle of Bacteriophytochrome Is Initiated by Counterclockwise Chromophore Isomerization.
2022
Photoactivation of bacteriophytochrome involves a cis–trans photoisomerization of a biliverdin chromophore, but neither the precise sequence of events nor the direction of the isomerization is known. Here, we used nonadiabatic molecular dynamics simulations on the photosensory protein dimer to resolve the isomerization mechanism in atomic detail. In our simulations the photoisomerization of the D ring occurs in the counterclockwise direction. On a subpicosecond time scale, the photoexcited chromophore adopts a short-lived intermediate with a highly twisted configuration stabilized by an extended hydrogen-bonding network. Within tens of picoseconds, these hydrogen bonds break, allowing the c…
Local Structure Studies of Ti for SrTi16O3 and SrTi18O3 by Advanced X-ray Absorption Spectroscopy Data Analysis
2015
Strontium titanate is a model quantum paraelectric in which in the region of dominating quantum statistics the ferroelectric instability is inhibited due to nearly complete compensation of the harmonic contribution into ferroelectric soft mode frequency by the zero-point motion contribution. The enhancement of atomic masses by the substitution of 18O for 16O decreases the zero-point atomic motion and low-T ferroelectricity in SrTi18O3 is realized. In this study we report on the local structure of Ti in SrTi16O3 and SrTi18O3 by Ti K-edge extended x-ray absorption fine structure measurements in temperature range 6 – 300 K.
Micro evidence for sources of innovation in European countries
2012
This paper investigates sources of product or process innovation, such as investments in research and development, machinery, personnel training and management systems, by examining microdata from eight European countries. We pay particular attention to the effect of research and development in favouring the absorption of new technologies, i.e. the absorptive capacity. Significant positive effects of each source on both product and process innovations are found. Significant evidence of positive absorptive capacity emerges only in firms with low predicted probabilities of introducing innovation.