224 research outputs found
\u27Parallel Universe\u27 or \u27Proven Future\u27? The Language of Dependent Means t-Test Interpretations
Of the three kinds of two-mean comparisons which judge a test statistic against a critical value taken from a Student t-distribution, one – the repeated measures or dependent-means application – is distinctive because it is meant to assess the value of a parameter which is not part of the natural order. This absence forces a choice between two interpretations of a significant test result and the meaning of the test hypothesis. The parallel universe view advances a conditional, backward-looking conclusion. The more practical proven future interpretation is a non-conditional proposition about what will happen if an intervention is (now) applied to each population element. Proven future conclusions are subject to the corrupting influence of time-displacement, which include the effects of learning, development, and history. These two interpretations are explored, and a proposal for new conceptual categories and nomenclature is given to distinguish them, applicable to other repeated measures procedures derived from the general linear model including ANOVA
Multiphysic FEMLAB modelling to evaluate mid-infrared photonic detector performances
National audienceInfrared photo detectors operating in the mid infrared region find application in pollution monitoring, high speed infrared imaging systems and free space telecommunications. Currently the dominant infrared detector technology are based on HgCdTe or InSb photovoltaic devices. Because of their narrow band gap these devices show at room temperature (RT) high dark reverse current and small R0.A product, which significantly restrict the getting of high ambient performances. To reduce the darkness current and increase R0.A product, we suggested studying structures with large band gap energy. The objective of the photo detector structures modelling presented in this paper is double. It allows first to simulate and to estimate the theoretical performances of previously introduced large band gap components. As such we shall calculate, the product R0.A and the quantum efficiency to end in the specific detectivity D*. It is also a support to help in the understanding and in the interpretation of the made photo detectors characterizations
Electrical properties of short period InAs/GaSb superlattice
International audienc
Self-consistent calculations of the energy and tunable emission spectra of doping superlattices
Based on the developed method of self-consistent calculations the results of description of tunable optical spectra versus
temperature and excitation level for the GaSb doping superlattices of different design are presented. Account of the
appearing tails of the density of states allows describing the long-wavelength edges and shape transformation in the
spectra of absorption, gain, and luminescence and peculiarities in the optical transitions characteristics. Possible laser
diode structures with n-i-p-i crystals in the active region are suggested including ordinary and δ-doped superlattices.
Effects of tunable lasing are examined and ways for control of the radiation wavelength are discussed
RETRATO SIN IDENTIFICAR [Material gráfico]
Copia digital. Madrid : Ministerio de Educación, Cultura y Deporte, 201
RETRATO DE NIÑOS [Material gráfico]
Copia digital. Madrid : Ministerio de Educación, Cultura y Deporte, 201
On DABAL-Me₃ promoted formation of amides
The range and utility of DABAL-Me3 couplings of methyl esters and free carboxylic acids with primary and secondary amines under a variety of conditions (reflux, sealed tube, microwave) has been compared for a significant range of coupling partners of relevance to the preparation of amides of interest in pharmaceutical chemistry. Commercial microwave reactors promote the fastest couplings and allow the use of significantly sterically hindered amines (primary and secondary) and carboxylic acids derivatives. The influence of microwave energy on the reaction system was shown to be typically related to thermal effects (over-pressuring and superheating)
RETRATO SIN IDENTIFICAR [Material gráfico]
Copia digital. Madrid : Ministerio de Educación, Cultura y Deporte, 201
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