Search results for "SAMPLE"
showing 10 items of 2270 documents
Analytical procedures for short chain chlorinated paraffins determination - How to make them greener?
2019
Abstract The aim of the following paper was to gather current scientific information about the analytical protocols dedicated to measuring the content level of short-chain chlorinated paraffins (SCCPs) in various types of environmental samples. Moreover, the data about the basic validation parameters of applied procedures for SCCPs determination are listed. The main issue which is highlighted in the paper is the possibility of the application of green analytical chemistry (GAC) principals in the SCCPs measuring process to reduce the environmental impact of the applied methodology. Analytical methods dedicated to SCCPs determination contain a significant number of steps and require advanced …
Determination of Selected Phthalates by Gas Chromatography–Mass Spectrometry in Personal Perfumes
2015
A simple and fast method is proposed to analyze commercial personal perfumes. Our method includes measurement of phthalates, known to be major sources of endocrine disruptor chemicals (EDC), which originate from the less volatile fraction of perfumes. The quantification of phthalates were carried out directly with no sample preparation required on 30 samples of commercial products using gas chromatography and mass spectrometry (GC-MS) as a detector. The total concentrations of 15 investigated compounds ranged from 17 to 9650 mg/L with an average of 2643 mg/L. The highest total concentration was found in cologne. Diethyl phthalate (DEP), diisobutyl phthalate (DiBP), di(2-ethylhexyl) phthalat…
Evaluation of sampling adsorbents and validation of a LC-HRMS method for determination of 28 airborne pesticides
2018
A new strategy for sampling, using a low-volume sampler, and determination of airborne pesticides by liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS) has been developed. The trapping efficiency of three adsorbents (sandwich PUF-XAD2-PUF; XAD-2 and XAD-4) was tested for 33 currently used pesticides and the first adsorbent (PUF-XAD2-PUF) was selected because it presented the highest retention capacity without breakthrough. Selected PUF-XAD2-PUF had the following design: 5 g of Amberlite XAD-2 sandwiched between two cylinders of PUF (6.87 cm(3), height: 1.4 cm, diameter: 2.5 cm). A validation of the analytical methodology that includes microwave extraction with e…
Attitudes toward gay men and lesbians and their relationship with gender role beliefs in a sample of chilean university students
2012
ABSTRACT. This paper analyzes the relation between gender role beliefs and prejudice toward gay men and lesbians in Chile. Participants were Chilean university students (N = 283). Results indicate that men are more prejudiced than women and religious people are more prejudiced than non-religious people. On the other hand, gender role beliefs mediate sex differences in prejudice. The participants' more traditional gender role beliefs hold more negative attitudes toward gay men and lesbians. Men are more prejudiced than women, particularly in their attitudes toward gay men. In addition, sex differences in attitudes toward lesbians and gay men are mediated by gender role beliefs.
Percepción sobre la violencia de género según el nivel educativo y el género
2014
El presente estudio tiene como objetivo comparar diferentes variables relacionadas con la violencia de género entre estudiantes universitarios y de otros niveles educativos y el género. La muestra está formada por 247 estudiantes. Los resultados apuntan diferencias estadísticamente significativas en función del nivel educativo en las variables percepción de los tipos de maltrato, aprobación de la violencia y tolerancia de conductas de riesgo, entre otras. La percepción de los estudiantes no universitarios frente a los universitarios los coloca en una situación de mayor riesgo ante la misma. Con respecto al género las diferencias se dan en algunas formas de actuar y en la percepción de los t…
State of the Art in Information Security Policy Development
2020
Despite the prevalence of research that exists under the label of “information security policies” (ISPs), there is no consensus on what an ISP means or how ISPs should be developed. This article reviews state-of-the-art ISP development by examining a diverse sample of literature on the subject. The definition and function of an ISP is studied first, revealing a rich tapestry of different notions behind the same term. When looking at the broad picture of the research on ISP development methods, we find different phases and levels of detail. Analyzing the different views on the content, context, and strategy alignment provides for further understanding on the complexity of the matter. As an o…
Low-cost approximate reconstructing of heterogeneous microstructures
2016
We propose an approximate reconstruction of random heterogeneous microstructures using the two-exponent power-law (TEPL). This rule originates from the entropic descriptor (ED) that is a multi-scale measure of spatial inhomogeneity for a given microstructure. A digitized target sample is a cube of linear size L in voxels. Then, a number of trial configurations can be generated by a model of overlapping spheres of a fixed radius, which are randomly distributed on a regular lattice. The TEPL describes the averaged maximum of the ED as a function of the phase concentration and the radius. Thus, it can be used to determine the radius. The suggested approach is tested on surrogate samples of cer…
Rapid construction of algebraic axioms from samples
1991
Abstract An axiom is called reliable if it is confirmed in several places in a given sample of algebra. A very effective algorithm for enumerating such axioms is described.
Good-genes effects in sexual selection
1999
The magnitude of the effect of good genes as a viability benefit accruing to choosy females remains a controversial theoretical and empirical issue. We collected all available data from the literature to estimate the magnitude of good-genes viability effects, while adjusting for sample size. The average correlation coefficient between male traits and offspring survival in 22 studies was 0.122, which differed highly significantly from zero. This implies that male characters chosen by females reveal on average 1.5% of the variance in viability. The studies demonstrated considerable heterogeneity in effect size; some of this heterogeneity could be accounted for by differences among taxa (birds…
Improving the Representativeness of a Simple Random Sample: An Optimization Model and Its Application to the Continuous Sample of Working Lives
2020
This paper proposes an optimization model for selecting a larger subsample that improves the representativeness of a simple random sample previously obtained from a population larger than the population of interest. The problem formulation involves convex mixed-integer nonlinear programming (convex MINLP) and is, therefore, NP-hard. However, the solution is found by maximizing the size of the subsample taken from a stratified random sample with proportional allocation and restricting it to a p-value large enough to achieve a good fit to the population of interest using Pearson&rsquo