Search results for "ELECTRONICS"
showing 10 items of 4340 documents
Performance of porous silica layers in open-tubular columns for liquid chromatography
1989
Abstract Progress has been made in the preparation of porous silica layers in fused-silica capillaries for open-tubular liquid chromatography. The porous silica layer is prepared by (i) static coating of the silica precursor, polyethoxysiloxane (PES), followed by (ii) converting the PES film into a porous silica layer with ammonia solution. The porous silica layer can be easily modified by silane reagents commonly used in packed column high-performance liquid chromatography. The performance of the silica layer with the different phase systems was tested with polyaromatic hydrocarbons and derivatized amino acids as samples.
Magnetic and structural investigations of ultra-thin Co–Fe alloy films on W(1 1 0)
2004
Abstract We investigated ultra-thin CoxFe1−x films on a flat and vicinal BCC W(1 1 0) surface with thicknesses between 1.8 and 7 monolayers (ML) using longitudinal Kerr magnetometry. We found a transition from magnetic bulk behavior between 3 and 4 ML to the monolayer. The maximum of the remnant Kerr signal that appears for thicker films at x=0.5 turns into a minimum for a sample thickness below 4 ML , while the specific Kerr-rotation per monolayer shows the well known bulk behavior. A similar magnetic behavior on the flat as well as on the stepped part of the substrate indicates that this is an intrinsic property. For x=0.5 the pseudomorphic monolayer is paramagnetic even when it is covere…
The COMPASS Setup for Physics with Hadron Beams
2015
The main characteristics of the COMPASS experimental setup for physics with hadron beams are described. This setup was designed to perform exclusive measurements of processes with several charged and/or neutral particles in the final state. Making use of a large part of the apparatus that was previously built for spin structure studies with a muon beam, it also features a new target system as well as new or upgraded detectors. The hadron setup is able to operate at the high incident hadron flux available at CERN. It is characterised by large angular and momentum coverages, large and nearly flat acceptances, and good two and three-particle mass resolutions. In 2008 and 2009 it was successful…
Growth of passive layers on nickel during their voltammetric anodic dissolution in a weakly acid medium
2006
Abstract Quartz crystal microbalance in combination with voltammetry has been used for studying the electrochemical oxidation behaviour of a nickel deposit in a weakly acid medium. The instantaneous mass/charge ratio (Fdm/dQ) analysis allows to obtain the fraction of charge consumed in the passivation process, and, that way, the experimental kinetic equation of the passive layer growth. This experimental law has been fitted to the theoretical equation derived from the point defect model theory under voltammetric conditions.
Characteristic Excitation Wavelength Dependence of Fluorescence Emissions in Carbon "quantum" Dots
2017
Carbon "quantum" dots (CDots), generally defined as small carbon nanoparticles with various surface passivation schemes, have emerged to represent a rapidly advancing and expanding research field. CDots are known for their bright and colorful fluorescence emissions, where the colorfulness is associated with the emissions being excitation wavelength dependent. In this work, CDots with 2,2′-(ethylenedioxy)bis(ethylamine) (EDA) for surface functionalization were studied systematically by using steady-state and time-resolved fluorescence methods. The observed fluorescence quantum yields are strongly excitation wavelength dependent, and the dependence apparently tracks closely the observed absor…
Zerstörungsfreie Phasenanalyse dünner Oberflächenschichten mittels Konversionselektronen
1987
By use of an appropriate gamma radiation, conversion electrons may be produced by Mossbauer effect also in a depth below the sample surface deeper than the free path for inelastic electron scattering. Because the Mossbauer spectrum of the conversion electrons reflects the local phase composition, the recording of all electrons escaping from the surface allows an integral phase analysis of a layer of some 10–100 nm thickness. If only electrons within a narrow range of energy are recorded, a depth selective phase analysis is possible. The applicability of these two techniques of conversion electron spectroscopy is demonstrated by a few examples concerning oxidation and passivation of steel. C…
Evaluation of a multispectral diffuse optical spectroscopy device for assessment of cardiometabolic risk related alterations of body composition
2013
Cardiometabolic diseases encompass a combination of conditions which lead to an increase in the risk of cardiovascular disease and diabetes. With the increasing percentage of the population becoming overweight, it is important to diagnose when the excess adipose tissue becomes malign. The development of a safe, mobile, non-invasive method that would be easy to perform, and low-cost, but also would offer an accurate assessment of subcutaneous adipose tissue (SAT) both in lean and in obese persons is required. A prototype device using an optical method for measurement of the SAT in vivo has been developed, it contains multiple LEDs with four wavelengths (660nm, 780nm, 870nm, 940nm) distribute…
Domain structure of epitaxial SrRuO3 thin films
2005
Growth of multidomains in epitaxial thin-film oxides is known to have a detrimental effect on some functional properties, and, thus, efforts are done to suppress them. It is commonly accepted that optimal properties of the metallic and ferromagnetic $\mathrm{SrRu}{\mathrm{O}}_{3}$ (SRO) epitaxies can only be obtained if vicinal $\mathrm{SrTi}{\mathrm{O}}_{3}$ (001) (STO) substrates are used. It is believed that this results from the suppression of multidomain structure in the SRO film. Here we revise this important issue. Nanometric films of SRO have been grown on STO(001) vicinal substrates with miscut $({\ensuremath{\theta}}_{V})$ angles in the $\ensuremath{\sim}0.04\ifmmode^\circ\else\te…
Comparison of free software platforms for the calculation of the 90% confidence interval of f2 similarity factor by bootstrap analysis
2020
Abstract Introduction The calculation of the 90% confidence interval of f2 based on the bootstrap methodology has been proposed and accepted by the main regulatory authorities when the dissolution data shows excessive variability. Different free software platforms allow the calculation of the 90% CI of f2 by means of bootstrapping. Their use in regulatory submissions is growing, but divergent results have been observed between the available software platforms. Therefore, the objective of this work is to analyze the characteristics of these software platforms and evaluate their results. Methods and materials Highly variable in vitro dissolution data from two products were selected. Three dif…
Bone Regeneration and Soft Tissue Enhancement Around Zygomatic Implants: Retrospective Case Series
2020
Purpose: To present a case series of zygomatic implants combined with bone regeneration and soft tissue enhancement techniques to reduce the risk of biological delayed complications such as maxillary sinusitis and soft tissue recession. Materials and methods: Zygomatic implants placed simultaneously with different bone regeneration techniques (buccal, palatal and buccal-palatal bone regeneration) and soft tissue enhancement techniques (pediculate and free connective tissue graft) were followed for at least 12 months. The following information was collected: patient age and sex, number of zygomatic implants, zygomatic implant success rate, zygomatic implant position according to classificati…