Search results for "SAMPLE"
showing 10 items of 2270 documents
Application of isotope-dilution laser ablation ICP-MS for direct determination of Pu concentrations in soils at pg g(-1) levels.
2003
The methods available for determination of environmental contamination by plutonium at ultra-trace levels require labor-consuming sample preparation including matrix removal and plutonium extraction in both nuclear spectroscopy and mass spectrometry. In this work, laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was applied for direct analysis of Pu in soil and sediment samples. Application of a LINA-Spark-Atomizer system (a modified laser ablation system providing high ablation rates) coupled with a sector-field ICP-MS resulted in detection limits as low as 3x10(-13) g g(-1) for Pu isotopes in soil samples containing uranium at a concentration of a few microg g(-1). …
Systematic procedure for the preparation of sets of calibration standards for x-ray fluorescence analysis of ceramic materials
1998
A systematic procedure for the preparation of optimized sets of calibration solid standards for the x-ray fluorescence analysis of ceramic materials is described. The matrix of the contents of the N analytes in the n standards (n ≥ N) is calculated from an n x N experimental design matrix, and from the upper and lower limits of the calibration range for each of the N analytes. Two procedures, which are useful for taking into account analyte interactions, are proposed for constructing the experimental design matrix, i.e. the scroll procedure and the procedure of the centers. A program developed to help the analyst in designing and preparing the set of standards following the proposed procedu…
FIA—FT—IR determination of ibuprofen in pharmaceuticals
1992
A method has been developed for the determination of Ibuprofen (2-[4-isobutylphenyl]-propionic acid) in pharmaceuticals by FT-IR, using the carbonyl band which this compound presents at 1710 cm(-1) in carbon tetrachloride solutions. Samples are dissolved in carbon tetrachloride. In this solvent the excipients are not soluble and so the drug can be directly determined without any additional treatment. The use of a simple FIA manifold permits one to carry out this analysis with a low consumption of reagent and the FT-IR provides a continuous monitoring of the spectral base-line which permits an accurate determination of the maximum in the absorbance band. Also, the FIA system permits easy and…
Demultiplexing Visible and Near-Infrared Information in Single-Sensor Multispectral Imaging
2016
In this paper, we study a single-sensor imaging system that uses a multispectral filter array to spectrally sample the scene. Our system captures information in both visible and near-infrared bands of the electromagnetic spectrum. Due to manufacturing limitations, the visible filters in this system also transmit the NIR radiation. Similarly, visible light is transmitted by the NIR filter, leading to inaccurate mixed spectral measurements. We present an algorithm that resolves this issue by separating NIR and visible information. Our method achieves this goal by exploiting the correlation of multispectral images in both spatial and spectral domains. Simulation results show that the mean squa…
A Short Measure of Acceptability of Intimate Partner Violence Against Women: Development and Validation of the A-IPVAW-8 Scale
2021
Attitudes of acceptability of intimate partner violence against women (IPVAW) are considered one of the main risk factors of this type of violence. The aim of this study is to develop and validate a short version of the acceptability of IPVAW scale, the A-IPVAW-8, for large scale studies where space and time are limited. A panel of experts were asked to assess item content validity. Two samples were recruited to assemble an 8-item short version of the scale using automated test assembly, and to reassess the psychometric properties of the A-IPVAW-8 in an independent sample. Results showed that the A-IPVAW-8 had adequate internal consistency (α = .72-.76, ω = .73-.81), a stable one-factor la…
The development and validation of a rapid method for the determination of antimicrobial agent residues in milk and meat using ultra performance liqui…
2014
Abstract A new multi-class method has been developed for the identification and quantification of the residues of 26 antibiotics from different classes (sulfonamides, macrolides, tetracyclines, penicillins, and quinolones) in milk and meat by ultra performance liquid chromatography coupled to hybrid quadrupole – high resolution Orbitrap mass spectrometry (UPLC–qOrbitrap). The sample preparation included extraction of two analytical portions with acetonitrile and 5% trichloroacetic acid, respectively, followed by centrifugation and filtration. The method was validated over three days at 50% of MRL (maximum residue limit) set in the European Union. Experiments on spiked meat and milk samples …
The Influence of Business Ecosystems on Innovation-Based Industries: A Research on the Mechanical Sector in Italy
2018
The business ecosystem perspective can be considered as a more advanced point of view for interpreting the development of local economic systems, if compared to more traditional concepts such as clusters, industrial districts, local or regional systems, and local networks. The business ecosystem perspective allows to better highlight the adaptive and evolutionary nature of local systems in front of the changing external environment and dynamics on national and international markets. The aim of the research was to analyze the key characteristics of firms belonging to a local business ecosystem specialized on an innovation-driven industry – the mechanical sector – in order to verify which kin…
Importance of work characteristics affects job performance: The mediating role of individual dispositions on the work design-performance relationships
2020
Abstract Work characteristics influence job performance but the individual values, reflected on the importance that employees place on each work characteristic, may affect this relationship. Drawing insights from personal salience and person-job fit theory, our research explored the partial mediation effect of importance given to work characteristics in the relation between 18 work characteristics and job performance in a sample of Colombian workers from different economic sectors (N = 817). We found that 17 out of 18 work characteristics indirectly influenced job performance through its effect on importance. These findings emphasize the role of personal antecedents on job performance with …
Patterns of Psychological Responses among the Public during the Early Phase of COVID-19: A Cross-Regional Analysis
2021
This study aimed to compare the mediation of psychological flexibility, prosociality and coping in the impacts of illness perceptions toward COVID-19 on mental health among seven regions. Convenience sampled online survey was conducted between April and June 2020 from 9130 citizens in 21 countries. Illness perceptions toward COVID-19, psychological flexibility, prosociality, coping and mental health, socio-demographics, lockdown-related variables and COVID-19 status were assessed. Results showed that psychological flexibility was the only significant mediator in the relationship between illness perceptions toward COVID-19 and mental health across all regions (all ps = 0.001–0.021). Seeking …
Relationship Between Mental Health and the Education Level in Elderly People: Mediation of Leisure Attitude.
2020
Purpose The present study intends to explore the influence of education on the mental health of retired people and the mediating role of a leisure attitude in this relationship. Design/methodology The sample was simple random, and a confidentiality agreement was established. The sample was composed of 403 Portuguese participants (37.2% male; 62.8% female). The participants completed the MHI and the LAS. Findings The hypothesized mediation model showed that a leisure attitude mediated the association between education and well-being. In addition, higher levels of distress were found in participants with higher levels of education. Scientific contribution Our results suggest that old-aged peo…