Search results for "visual"

Determination of trace elements in gluten-free food for celiac people by ICP-MS

2014

Abstract This paper is the first analytical approach to the study of twenty heavy metals in the gluten-free foods for celiac people. Only the ICP-MS technique was used. One of the advantages about the use of ICP-MS for this characterization is the high sensitivity that improved the limits of quantification levels for some elements that are present at low quantities in some samples. The concentration values of As, Ba, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Sb, Se, Sn, V and Zn in seventeen gluten-free food samples are reported. The highest arsenic and molybdenum levels were measured in Rice noodle from China (0.088 and 0.47 mg kg − 1 , respectively). The highest concentrations of some metal…

ChemInform Abstract: High-Temperature Hall Measurements on BaSnO3 Ceramics.

2010

Quantitative Phase Analysis of Mixtures of Three Components using Rietveld and Rius Standardless Methods. Comparative Results

2000

Eight samples, supplied by the Commission on Powder Diffraction of the International Union of Crystallography, through the Round Robin on quantitative phase analysis, were analized using standardless methods. Samples were mixtures of corundum, zincite and fluorite in different ratios. The Rietveld method, using the DBW 3.2 and FULLPROF software, and the Rius method, using MENGE-PC software, were used. Results obtained agree well with the real composition supplied (a posteriori) by the IUCr.

Dyes That Bear Thiazolylazo Groups as Chromogenic Chemosensors for Metal Cations

2011

A family of dyes (L 1-L 6) that contain a thiazolylazo group as signalling subunit and several macrocyclic cavities with different ring sizes and type and number of heteroatoms as binding sites has been synthesized and characterized. Solutions of L 1-L 6 in acetonitrile show broad and structureless absorption bands in the 554-577 nm range with typicalmolar absorption coefficients that range from 20000 to 32000 M -1 cm -1. A detailed protonation study was carried out with solutions of L 1, L 2 and L 5 in acetonitrile. Addition of one equivalent of protons to L 1 and L 2 resulted in the development of a new band at 425 and 370 nm, respectively, which was ascribed to protonation in the aniline…

Minimization of childhood maltreatment is common and consequential: results from a large, multinational sample using the childhood trauma questionnai…

2016

Childhood maltreatment has diverse, lifelong impact on morbidity and mortality. The Childhood Trauma Questionnaire (CTQ) is one of the most commonly used scales to assess and quantify these experiences and their impact. Curiously, despite very widespread use of the CTQ, scores on its Minimization-Denial (MD) subscale-originally designed to assess a positive response bias-are rarely reported. Hence, little is known about this measure. If response biases are either common or consequential, current practices of ignoring the MD scale deserve revision. Therewith, we designed a study to investigate 3 aspects of minimization, as defined by the CTQ's MD scale: 1) its prevalence; 2) its latent struc…

Dependence of solvent quality on the composition of copolymers: experiment and theory for solutions of P(MMA-ran-t-BMA) in toluene and in chloroform.

2014

The interaction of toluene with P(MMA-ran-t-BMA) and with the corresponding homopolymers was determined via vapor pressure measurements at 30, 50 and 70 °C. A unified thermodynamic approach served for the modeling of the results. It is capable of describing the behavior of the different solutions by means of two adjustable parameters, one representing the effective number of solvent segments and the other accounting for the interactions between the components. The solvent quality of toluene passes a maximum, a minimum and another maximum upon an increase of the t-BMA content of the copolymer at all temperatures. A similar behavior is discernable from vapor pressure data of chloroform publis…

Influence of lower rim C-methyl group on crystal forms and metal complexation of resorcinarene bis-crown-5

2015

C-methyl resorcinarene bis-crown-5 (1) with pendant methyl groups at the lower rim was prepared and crystallized in various solvent mixtures with and without selected metal salts. The crystal structures of two polymorphic forms of unsolvated 1 (1-I and 1-II), three solvates (acetonitrile, chloroform and dichloromethane-methanol), and three metal complexes with silver and cesium salts were obtained. The lower rim methyl groups and the block shape of the host promote crystal packing in brick-wall type assemblies, in which the binding cavities are efficiently filled by the crown bridges. Thus, solvents are found in the interstitial space or coordinated to the crown bridges on top of the cavity…

EXPERIENCES OF STRUCTURE ANALYSES OF CHLOROPHENOL DIMERS AND TRIMERS FOUND IN DIFFERENT SAMPLES

1982

ABSTRACT Chlorophenol formulations (Kymi/Kymmene Co., wood preservatives), sawmill wood waste samples and different waste treatment product samples were analyzed for oligomeric by-products of the polychlorinated phenols. Structure types for 26 phenolic dimers, 45 neutral dimers and 13 phenolic trimers were determined by GC/MS. Types of one tetrachloro and one hexachloro compound detected remained unknown. Contents of by-products in chlorophenol formulations varied greatly depending on their production method. Chemical treatment of wastes with NaClO and NaOH lowered their contents of chlorophenols and phenolic dimers, but did not change (NaOH) or increased (NaClO) the contents of neutral dim…

Folding in vitro of light-harvesting chlorophyll a/b protein is coupled with pigment binding.

2002

The major light-harvesting chlorophyll a/b protein (LHCIIb) of the plant photosynthetic apparatus is able to self-organise in vitro. When the recombinant apoprotein, Lhcb1, is solubilised in the denaturing detergent sodium (or lithium) dodecylsulfate (SDS or LDS) and then mixed with chlorophylls and carotenoids under renaturing conditions, structurally authentic LHCIIb forms. Assembly of functional LHCIIb, as indicated by the establishment of energy transfer between complex-bound chlorophyll molecules, occurs in two apparent kinetic steps with time constants of 10 to 30 seconds and 50 to 300 seconds, depending on the reaction conditions. Here, we use circular dichroism (CD) in the far-UV ra…

Physiological Aspects of Nitrogen Fertilizer Impact on Latvian Origin Cannabis Sativa L .

2015

The aim of the present study was to evaluate nitrogen fertilizer impact on photosynthesis and yield of hemp, applying modern non-destructive methods. The main object of the investigation – hemp cultivar of Latvian origin ‘Pūriņi’. Laboratory and field experiments showed diverse effects of different nitrogen fertilizer doses on various parameters. Additional nitrogen fertilizer dose of 60 kg ha-1 is most effective as evaluated by chlorophyll content in hemp leaves and changes of chlorophyll a fluorescence parameters. Nitrogen fertilizer negatively affected fiber content in hemp stems, therefore while cultivating hemp only for fiber production use of nitrogen fertilizer should be reduced. Acc…