Search results for "SAMPLE"
showing 10 items of 2270 documents
Determination of Glyphosate and AMPA in Food Samples Using Membrane Extraction Technique for Analytes Preconcentration
2022
The method for determining glyphosate (NPG) and its metabolite AMPA (aminomethyl phosphonic acid) in solid food samples using UAE-SLM-HPLC–PDA technique was developed. Firstly, ultrasonic-assisted solvent extraction (UAE) and protein precipitation step were used for the analyte isolation. Then, the supernatant was evaporated to dryness and redissolved in distilled water (100 mL). The obtained solution was alkalized to pH 11 (with 1 M NaOH) and used directly as donor phase in SLM (supported liquid membrane) extraction. The SLM extraction was performed using 2 M NaCl (5 mL) as an acceptor phase. The flow rate of both phases (donor and acceptor) was set at 0.2 mL/min. The membrane extraction t…
Single hollow fiber SLM extraction of polyamines followed by tosyl chloride derivatization and HPLC determination
2007
Determination of polyamines in biological fluids possesses medical diagnostic relevance. Despite the vast panel of analytical methods developed for polyamines they are not applied in routine clinical usage, mainly due to the time and labor consuming sample preparation step and complicated derivatization procedures. Thus, new simpler methods are needed. This paper describes a single hollow fiber SLM extraction method of polyamines followed by simple pre-column derivatization with tosyl chloride and HPLC-UV analysis. The influence of different parameters such as the extraction time, organic phase composition, acceptor pH, donor pH, acceptor volume, donor volume and stirring speed on the trans…
Multivariate optimization of the hollow fibre liquid phasemicroextraction of muscimol in human urine samples
2016
A liquid phase microextraction based on hollow fibre followed by liquid chromatographic determinationwas developed for the extraction and quantitation of the hallucinogenic muscimol from urine samples.Method applicability on polar hallucinogens was also tested on two alkaloids, a psychedelic hallucinogen,tryptamine and a polar amino acid, tryptophan which exists in its charged state in the entire pH range. Amultivariate design of experiments was used in which a half fractional factorial approach was applied toscreen six factors (donor phase pH, acceptor phase HCl concentration, carrier composition, stirring rate,extraction time and salt content) for their extent of vitality in carrier media…
Perceived threat or perceived benefit? Immigrants’ perception of how Finns tend to perceive them
2022
Research on how immigrants are perceived by locals has flourished extensively within the past decades. Through the lens of integrated threat theory and the threat benefit model, this study examines immigrants’ perceptions of how Finns tend to perceive them based on their lived experiences. In a sample of 103 immigrants from over 40 nationalities living in Finland, results indicate that overall, immigrants believe they are perceived more as a threat than a benefit to the Finnish society. Implications and opportunities for further research are discussed as well. peerReviewed
Teachers' attitudes and self-efficacy on implementing inclusive education in Japan and Finland: A comparative study using multi-group structural equa…
2018
Abstract This study aims to explore relationships between teachers' attitudes, self-efficacy, and background variables regarding inclusive education by using a sample of 359 Japanese and 872 Finnish teachers. A multi-group structural equation modelling was conducted to find similarities and differences in how the background variables predict teachers' attitudes and self-efficacy. Experience in teaching students with disabilities had a positive effect on teachers' attitudes and self-efficacy in both countries. However, teachers' teaching career and the amount of inclusive education training affected them differently in Japan and Finland. The findings could be used to improve inclusive educat…
Measuring pre-service teachers' attitudes towards inclusive education: Psychometric properties of the TAIS scale
2015
The Teachers’ Attitudes towards Inclusive Education (TAIS) scale was designed to measure pre-service teachers’ attitudes towards inclusion, as defined in the Salamanca Statement of UNESCO. The 10-item scale was developed using a sample of 185 final-year pre-service subject teachers. It was validated in four subsequent studies with various samples of teachers and pre-service teachers. The unidimensionality of the scale was established in all samples except the first-year students, and its validity was confirmed in psychometric analyses. The scale is suggested for use in intervention studies aiming to develop positive attitudes towards inclusion among teachers and pre-service teachers. peerRe…
Statements About the Pervasiveness of Behavior Require Data About the Pervasiveness of Behavior
2020
Despite recent close attention to issues related to the reliability of psychological research (e.g., the replication crisis), issues of the validity of this research have not been considered to the same extent. This paper highlights an issue that calls into question the validity of the common research practice of studying samples of individuals, and using sample-based statistics to infer generalizations that are applied not only to the parent population, but to individuals. The lack of ergodicity in human data means that such generalizations are not justified. This problem is illustrated with respect to two common scenarios in psychological research that raise questions for the sorts of the…
The closer¿ the unsafer: may the lack of safe distance be a silent contributor to the burden of traffic crashes in Spain?
2020
Not keeping an adequate safe distance is one of the elements that are directly related to traffic accidents. The main objective of this research was to identify the aspects that modulate the safe distance-accidents relation. Specifically, the frequency and reasons why drivers do not keep the safe distance, the perception of drivers regarding the probability of penalty, the penalties imposed and their severity, and the drivers’ opinion on the effectiveness of such penalties in order to change this behavior. A questionnaire was administrated to a sample of 1,100 Spanish drivers having any kind of driving license. The results showed that only the 5,6% of drivers always or sometimes do not keep…
Removal of hexavalent chromium from wastewaters by bone charcoal
1999
The adsorption of hexavalent chromium onto bone charcoal was studied as a function of time, amount of charcoal, pH, concentration of chromium and sample volume. The cross interference with other elements was also investigated. Tests were carried out with solutions of chromium(VI) at concentrations between 5 and 25 mg · L–1. Chromium removal efficiencies higher than 90% were achieved at pH = 1 using 2 g of bone charcoal and a stirring time in the order of 30 min. Acid and alkaline pretreatments of bone charcoal did not improve the sorption capacity of bone charcoal against Cr(VI). The presence of other ions had practically no influence on the chromium removal. The presence of a matrix of tan…
Exploring Creativity Expectation in CS1 Students’ View of Programming
2020
Full paper in Research category: Literature provides creativity definitions that are applicable to educational settings. For example, the definition by Plucker et al. emphasizes the ‘social context’ in which the usefulness and novelty of a creative outcome is evaluated, and notes that this emphasis allows students’ coursework to be deemed creative without extraordinary characteristics. Computing educators tend to assume that incoming CS course populations welcome creativity, and utilize application contexts (e.g., games, media, arts, and robots) in which creativity is a central attribute. Previous research also suggests that beginner CS students may initially possess versatile identities re…