Search results for "Standards"
showing 10 items of 394 documents
Determination of fatty alcohol ethoxylates by derivatisation with maleic anhydride followed by liquid chromatography with UV-vis detection.
2007
The esterification of fatty alcohol ethoxylates (FAEs) by melting with maleic anhydride has been studied in the presence of urea. The reaction rate and yield of non-ethoxylated and ethoxylated alcohols increase largely when grinded urea is suspended in the reaction medium, a 100% yield being achieved at 80 degrees C in 15 min. The procedure is tolerant to the presence of large amounts of water. The UV-vis response factors of the derivatives of individual FAE oligomers vary little with the number of carbon atoms in the alkyl chain, n, and the number of ethylene oxide units, m. Derivatised samples of industrial FAE mixtures, cleaning products and river and sea waters were chromatographed on a…
Monte Carlo calculation of dose rate distributions around 192Ir wires.
1997
Monte Carlo calculations of absolute dose rate in liquid water are presented in the form of away-along tables for 1 and 5 cm 192 Ir wires of 0.3 mm diameter. Simulated absolute dose rate values can be used as benchmark data to verify the calculation results of treatment planning systems or directly as input data for treatment planning. Best fit value of attenuation coefficient suitable for use in Sievert-integrals-type calculations has been derived based on Monte Carlo calculation results. For the treatment planning systems that are based on TG43 formalism we have also calculated the required dosimetry parameters.
Understanding 802.11e contention-based prioritization mechanisms and their coexistence with legacy 802.11 stations
2005
The IEEE 802.11e task group has reached a stable consensus on two basic contention-based priority mechanisms to promote for standardization: usage of different arbitration interframe spaces and usage of different minimum/maximum contention windows. The goal of this article is to provide a thorough understanding of the principles behind their operation. To this purpose, rather than limit our investigation to high-level (e.g. throughput and delay) performance figures, we take a closer look at their detailed operation, also in terms of low-level performance metrics (e.g., the probability of accessing specific channel slots). Our investigation on one hand confirms that AIFS differentiation prov…
Innovation in Physical Education: Back to the principles of procedure
2018
El sistema educativo español ha sufrido, en los últimos años, numerosas modificaciones que lo han ido transformando. Una parte de ellas se ha centrado en la introducción de nuevos elementos en el currículum, como las competencias clave y los estándares de aprendizaje evaluables, que han cambiado la forma de concebir la educación y que se perciben como posturas innovadoras por parte del profesorado. Desgraciadamente, este modelo por competencias y por estándares ha recuperado un paradigma educativo centrado en el producto, es decir, la pedagogía por objetivos. Este modelo centra la atención del profesorado en ajustar la práctica educativa a criterios preestablecidos por las propias leyes a t…
Professionalisation and quality management: struggles, boundaries and bridges between two approaches
2011
European journal for Research on the Education and Learning of Adults 2 (2011) 1, S. 21-35
The long and winding road: Accidents and tinkering in software standardization
2021
Software is based on universal principles but not its development. Relating software to hardware is never automatic or easy. Attempts to optimize software production and drastically reduce their costs (like in hardware) have been very restricted. Instead, highly-skilled and experienced individuals are ultimately responsible for project success. The long and convoluted path towards useful and reliable software is often plagued by idiosyncratic accidents and emergent complexity. It was expected that software standardisation would remove these sources of unwanted diversity by aiming to controllable development processes, universal programming languages, and toolkits of reusable software compon…
Systematic review of chewing simulators : reality and reproducibility of in vitro studies
2020
Background The aim of this systematic review was to analyze the types of human chewing simulator described in scientific literature. Material and Methods An electronic search was conducted in the databases PubMed, Embase and Scopus. The search strategy included 10 search terms: “in vitro”; “dental materials”; “shear strength”; “fatigue fracture”; “bite force”; “prosthetic materials”; “chewing simulator”; “chewing machine”; “simulated mastication”; and “dental wear simulator.” Two researchers worked independently to assess the titles and abstracts of the articles. The quality of the in vitro trials selected was evaluated by means of the Consolidated Standards of Reporting Trials scale. Resul…
Minimal Information About an Immuno-Peptidomics Experiment (MIAIPE)
2018
Minimal Information about an Immuno-Peptidomics Experiment (MIAIPE) is an initiative of the members of the Human Immuno-Peptidome Project (HIPP), an international program organized by the Human Proteome Organization (HUPO). The aim of the MIAIPE guidelines is to deliver technical guidelines representing the minimal information required to sufficiently support the evaluation and interpretation of immunopeptidomics experiments. The MIAIPE document has been designed to report essential information about sample preparation, mass spectrometric measurement and associated mass spectrometry (MS)-related bioinformatics aspects that are unique to immunopeptidomics and may not be covered by the genera…
Multi-laboratory experiment PME11 for the standardization of phosphoproteome analysis
2022
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Alignment between standardized assessments and academic standards : the case of the Saber Mathematics Test in Colombia
2013
Resumen basado en el de la publicación Título, resumen y palabras clave en español e inglés Disponible la versión en inglés Análisis del concepto de alineación presentando los resultados de un estudio que examina el grado de alineación entre una evaluación estandarizada de matemáticas y unos estándares académicos. La alineación se examina usando el modelo de Webb y los resultados sugieren que el grado de alineación entre las evaluaciones estandarizadas y los estándares académicos no es el más adecuado y por lo tanto los resultados se deben interpretar con mucha cautela y se debe poner mucho cuidado con el tipo de decisiones que se toman con base en los resultados. ESP