Search results for "ROMA"
showing 10 items of 13919 documents
A capillary liquid chromatography method for benzalkonium chloride determination as a component or contaminant in mixtures of biocides
2015
A method for quantifying benzalkonium chloride (BAK), an alkyl dimethyl benzyl ammonium compound, in several biocides formulations is proposed. A tertiary amine like N-(3-aminopropyl)-N-dodecyl-1,3-propanediamine (TA) and a straight-chain alkyl ammonium compound like trimethyl-tetradecyl ammonium chloride (TMTDAC), have been employed as trade surfactants besides BAK. Two capillary analytical columns with different polarities are tested: inertsil CN-3 capillary column (150mm×0.5mm i.d., 3μm particle diameter) and a non endcapped Zorbax C18 capillary column (35mm×0.5mm i.d., 5μm particle diameter). This latter column provided the best separation of the BAK homologues in less than 12min using …
Sample Preparation Improvement in Polycyclic Aromatic Hydrocarbons Determination in Olive Oils by Gel Permeation Chromatography and Liquid Chromatogr…
2005
Abstract The determination of 15 polycyclic aromatic hydrocarbons (PAHs) in olive oil samples has been improved in order to obtain a fast methodology with a low limit of detection through the combination of liquid–liquid extraction with acetonitrile and preparative gel permeation chromatography (GPC) prior to the injection of purified extracts into a C18 column. Acetonitrile–water was used as the mobile phase with a gradient from 50 to 95%, w/w, acetonitrile in 30 min. The oven temperature was maintained at 15°C, and fluorometric detection was made at a fixed excitation wavelength of 264 nm and variable, optimal emission wavelength for each analyte ranging from 352 nm for 11-H-benzo(b)fluor…
Impact of viewing distance on relative depth judgements for stimuli in physical space
2019
In natural viewing, numerous depth cues are available to the visual system, but their significance varies considerably depending on the viewing distance. How is it reflected in the outcome of depth judgements? We have designed a psychophysical experiment with a limited number of depth cues to examine distance-related changes in the correct response rate and time. Twenty young adults evaluated relative depth of stimuli in physical space. Each time four constant angular size achromatic stimuli were presented on a volumetric multi-planar display. One of these stimuli was demonstrated closer to the observer comparing to others. The experiment followed the four-interval forced-choice procedure. …
CNGB3 mutations account for 50% of all cases with autosomal recessive achromatopsia
2005
Contains fulltext : 47591.pdf (Publisher’s version ) (Closed access) Achromatopsia is a congenital, autosomal recessively inherited disorder characterized by a lack of color discrimination, low visual acuity (<0.2), photophobia, and nystagmus. Mutations in the genes for CNGA3, CNGB3, and GNAT2 have been associated with this disorder. Here, we analyzed the spectrum and prevalence of CNGB3 gene mutations in a cohort of 341 independent patients with achromatopsia. In 163 patients, CNGB3 mutations could be identified. A total of 105 achromats carried apparent homozygous mutations, 44 were compound (double) heterozygotes, and 14 patients had only a single mutant allele. The derived CNGB3 mutatio…
A comparison among different techniques for human ERG signals processing and classification
2014
A comparison among different techniques for human ERG signals processing and classification ( Articles not published yet, but available online Article in press About articles in press (opens in a new window) ) Barraco, R.a, Persano Adorno, D.a , Brai, M.a, Tranchina, L.b a Dipartimento di Fisica e Chimica, Università di Palermo and CNISM, Viale delle Scienze, Ed. 18, I-90128 Palermo, Italy b Laboratorio di Fisica e Tecnologie Relative - UniNetLab, Università di Palermo, Viale delle Scienze, Ed. 18, I-90128 Palermo, Italy Abstract Feature detection in biomedical signals is crucial for deepening our knowledge about the involved physiological processes. To achieve this aim, many analytic appro…
Mutations in the Cone Photoreceptor G-Protein α-Subunit Gene GNAT2 in Patients with Achromatopsia
2002
Achromatopsia is an autosomal recessively inherited visual disorder that is present from birth and that features the absence of color discrimination. We here report the identification of five independent families with achromatopsia that segregate protein-truncation mutations in the GNAT2 gene, located on chromosome 1p13. GNAT2 encodes the cone photoreceptor-specific alpha-subunit of transducin, a G-protein of the phototransduction cascade, which couples to the visual pigment(s). Our results demonstrate that GNAT2 is the third gene implicated in achromatopsia.
Renewable polyol obtained by microwave-assisted alcoholysis of epoxidized soybean oil: Preparation, thermal properties and relaxation process
2019
[EN] The soybean oil polyol (SOP) use as feedstock in the polyurethane industry has been recently emphasized due to its excellent resistance to hydrolysis, which is also applicable in coatings and thermal insulation. In this article, the SOP was obtained by a very fast microwave-assisted alcoholysis of epoxidized soybean oil (ESO). The preparation method, thermal properties, and relaxation process were evaluated. High yields as opening and consumption epoxy group and selectivity of 99.8 mol%, 985 mol%, and 71.2 mol% were obtained. Through titrations, nuclear magnetic resonance and gel permeation chromatography were identified parameters as 0.32 mg KOH.g(-1) acid number, 190 mg KOH.g(-1) hyd…
Magnetic properties of Co2Mn1−xFexSi Heusler alloys
2006
Co2Mn1−xFexSi Heusler alloys with Fe concentration x = 0–0.4 as prepared by arc melting show a L21 long range order for all Fe concentrations. Magnetic properties of Co2Mn1−xFexSi Heusler alloys were investigated by magnetometry and circular magnetic dichroism. The magnetization of the Fe doped Heusler alloys is in agreement with the Slater–Pauling values expected for half-metallic ferromagnets. Element specific magnetic moments as determined by x-ray absorption using the total electron yield method are in disagreement with theoretical predictions for x = 0 but approach the predicted values as the Fe concentration increases. Surprisingly small Fe concentration increases the magnetic moments…
High-spin polarization of Heusler alloys
2006
Fermi surface of a half-metal compound with cubic Fm–3m symmetry: Heusler alloy or double perovskite.The inset shows the spin resolved density of state for a CCFA Heusler compound. ( This illustration appears on the cover of the print edition. ) This cluster issue of Journal of Physics D: Applied Physics is devoted to magnetic Heusler alloys. This class of materials is currently considered to contain the most attractive half-metallic ferromagnets due to their high Curie temperatures and their structural relation to conventional semiconductors. The first compound to be identified as a half-metallic ferromagnet, by de Groot et al back in 1983, was the half-Heusler alloy NiMnSb. After a period…
A spatially resolved investigation of the local, micro-magnetic domain structure of single and polycrystalline Co2FeSi
2007
The Heusler compound Co2FeSi is a promising material for magneto-electronic devices. With a Curie temperature of 1100?K and a saturation magnetization of 6?Bohr magnetons and a high spin polarization at the Fermi edge it fulfils the essential requirements for magnetic sensors or spin valve structures. An essential feature for such devices is the micro-magnetic domain structure. X-ray magnetic circular dichroism?photo emission electron microscopy has been used for a direct observation of the domain structure of single- and polycrystalline samples. The polycrystalline material exhibits a micro-magnetic ripple structure, as it is well known for pure Co and other polycrystalline Heusler compoun…