Search results for " Reference"

Validated fast procedure for trace element determination in basil powder

2011

Abstract An inductively coupled plasma optical emission spectroscopic (ICP-OES) method has been developed and fully validated for trace element determination in basil samples. The method involves the previous sample digestion, under pressure, with a mixture of HNO 3 , HCl and H 2 O 2 inside a microwave oven, 42 elements were studied and 33 elements (Al, As, Ba, Ca, Cr, Co, Cu, Fe, Pb, Li, Mg, Mn, Mo, Ni, K, Se, Na, Sr, Tl, Ti, V, Zn, Sc, Y, La, Ce, Nd, Tb, Ho, Er, Tm, Yb, Lu) were determined quantitatively in basil leaves obtained from Morocco and Spain. The method provided recovery percentages from 89% to 113% for spiked concentrations at mg kg −1 and μg kg −1 . Accurate results were found…

Double Laser LIBS and micro-XRF spectroscopy applied to characterize materials coming from the Greek-Roman theater of Taormina

2009

The laser-induced breakdown spectroscopy (LIBS) is an applied physical technique that has shown, in recent years, its great potential for rapid qualitative analysis of materials. The possibility to implement a portable instrument that perform LIBS analysis makes this technique particularly useful for in situ analysis in the field of cultural heritages. The aim of this work is to compare the results, obtained by LIBS measurements with X-Ray Fluorescence (XRF) ones, on calcareous and refractory materials coming from the Greek-Roman theater of Taormina. Calibration curves for LIBS and XRF were obtained by measuring certified reference materials and using them as standards. LIBS measurements we…

Development of standard operation procedures for the manufacture of n-octadecyl bonded silicas as packing material in certified reference columns for…

2004

The development of standard operation procedures for the manufacture of a n-octadecyl bonded spherical silica packing from partially condensed tetraethoxysilane as silica source is described. The synthesis comprises five intermediate products and six synthesis steps which were examined according to their reproducibility and robustness. The results led to the optimisation of the manufacturing process for a n-octadecyl bonded silica. Correlations were drawn between the dynamic viscosity of the poly(ethoxy)siloxane (PES), the synthesis parameters, the resulting pore structural properties and particle size distribution of the silicas. Validated procedures were developed to manufacture spherical…

Hard cap espresso extraction-stir bar preconcentration of polychlorinated biphenyls in soil and sediments.

2017

Abstract A Nespresso © hard cap espresso machine has been employed for the quantitative extraction of polychlorinated biphenyls (PCBs) from sediments and soils. Sample extraction was performed from five grams of sample in less than 40 s, with 200 mL ethanol 40% (v/v) in water and PCBs were concentrated using stir bar sorptive extraction (SBSE) and determined by thermal desorption-gas chromatography-tandem mass spectrometry (TD-GC-MS-MS). Eleven PCB congeners (28, 52, 77, 80, 81, 101, 118, 138, 153,169, and 180) were determined in soils and sediments with limits of quantification in the 0.03–0.08 ng g −1 range. Extraction efficiency was established by the analysis of soil samples spiked with…

Assessment of Dietary Intake of Chromium (III) in Relation to Tolerable Upper Intake Level

2018

Progress in the standardisation of particle and surface characterisation

2002

In 1999, we published a comprehensive survey of standards and certified reference materials for dispersed and porous solids. The present paper summarises and reports on new standards and proposals.

Assessing interactional skills in a paired speaking test : raters’ interpretation of the construct

2019

The operationalization of interactional competence (IC) within the paired speaking test format allows for a range of interactional skills to be tested. However, in terms of assessment, challenges are posed with regard to the co-constructed nature of IC, making investigations into raters’ perceptions of the construct essential to inform test score interpretation. This qualitative study explores features of IC that raters attended to as they evaluated performances in a paired speaking test, part of a Swedish national test of English as a Foreign Language (EFL). Two groups of raters, 17 EFL teachers from Sweden, using national standards based on the Common European Framework of Reference for L…

The National Bilingual Programme in Colombia: Imposition or Opportunity?

2011

The National Bilingual Programme, created by the Colombian Ministry of Education in 2004, offers all students in the county the possibility of becoming bilingual in English and Spanish as part of a vision of increased productivity in a globalised world. However, the language and education policies promoted within this framework tend to foreground the development of English at the expense of bilingual competence in Spanish and English. This bilingual policy has been strongly criticised by several Colombian academics with regard to what they consider as the imposition in the Colombian context of the Common European Framework of Reference for Languages, the disregard of local knowledge and exp…

Use your languages! : From monolingual to multilingual interaction in a language class

2015

This reflective paper presents a new course concept for multilingual interaction, which was piloted at the University of Jyväskylä Language Centre in the spring of 2014. The course, implemented as part of the centre’s action research, is the result of a development process aimed at enhancing students’ multilingual and multicultural academic communication competences along with promoting use of their entire linguistic repertoire. The course concept was inspired by the EU project Modularising Multilingual and Multicultural Academic Communication Competence (MAGICC), whose main intent is “to integrate multilingual and multicultural academic communication competences as graduate learning outcom…

Developing a conceptual framework : the case of MAGICC

2015

This paper reports the steps taken to develop the conceptual framework of the MAGICC project (2013), which aimed to provide action-oriented descriptions of multilingual and multicultural academic and professional communication competence, instructional designs to promote these in higher education language teaching, and multidimensional forms of assessment aligned with the learning outcomes established – all presented in an academic ePortfolio that expands the features of the existing European Language Portfolio (ELP) to the higher education level. “Starting with systematic desk research into the existing conceptualisations of multi/plurilingual and multi/ intercultural competences as well a…