Search results for "methods"
showing 10 items of 4526 documents
Nopal Cactus (Opuntia ficus-indica) as a Source of Bioactive Compounds for Nutrition, Health and Disease
2014
Opuntia ficus-indica, commonly referred to as prickly pear or nopal cactus, is a dicotyledonous angiosperm plant. It belongs to the Cactaceae family and is characterized by its remarkable adaptation to arid and semi-arid climates in tropical and subtropical regions of the globe. In the last decade, compelling evidence for the nutritional and health benefit potential of this cactus has been provided by academic scientists and private companies. Notably, its rich composition in polyphenols, vitamins, polyunsaturated fatty acids and amino acids has been highlighted through the use of a large panel of extraction methods. The identified natural cactus compounds and derivatives were shown to be e…
Application of MOOSY32 eNose to Assess the Effects of Some Post Harvest Treatments on the Quality of ‘Salustiana’ Orange Juice
2015
A new prototype of Electronic Nose instrument, Multisensory Odor Olfactory System MOOSY32, with a processing method based on a multivariate classification analysis was used to assess different postharvest and storage treatments effects to Salustiana oranges. The analysis method is based on the measurement of the volatile compounds produced under different environmental and operational conditions. The Electronic Nose system revealed that orange juice flavor changes even when juices are analyzed right after each treatment and fruits are stored under refrigerated conditions. The instrument was able to detect even small changes in the aromatic pattern of the juices, confirming that the packing …
Radio detection of the young binary HD 160934
2013
Precise determination of dynamical masses of pre-main-sequence (PMS) stars is essential to calibrate stellar evolution models that are widely used to derive theoretical masses of young low-mass objects. Binary stars in young, nearby loose associations are particularly good candidates for this calibration since all members share a common age. Interestingly, some of these young binaries present a persistent and compact radio emission, which makes them excellent targets for astrometric VLBI studies. We aim to monitor the orbital motion of the binary system HD 160934, a member of the AB Doradus moving group. We observed HD 160934 with the Very Large Array and the European VLBI Network at 8.4 an…
Comparing Boosting and Bagging for Decision Trees of Rankings
2021
AbstractDecision tree learning is among the most popular and most traditional families of machine learning algorithms. While these techniques excel in being quite intuitive and interpretable, they also suffer from instability: small perturbations in the training data may result in big changes in the predictions. The so-called ensemble methods combine the output of multiple trees, which makes the decision more reliable and stable. They have been primarily applied to numeric prediction problems and to classification tasks. In the last years, some attempts to extend the ensemble methods to ordinal data can be found in the literature, but no concrete methodology has been provided for preference…
A comparative study of encapsulation structures for OLEDs
2007
Encapsulation is the final and most important step in the fabrication of organic light emitting diodes (OLEDs). An OLED operated in air can have a lifetime, defined as the time it takes for the luminance to decrease to half of its initial value, up to a few hours or less [1] due to degradation mechanisms induced by water vapour and oxygen. For emerging niche applications, such as OLED fluorescence biosensors [2] for routine laboratory analysis, the OLED is operated for a short period of time and then it must be disposed of. In this case OLEDs lifetimes of the order of a few hundreds of hours at initial luminance values in the range (500 1000) cd/m2 can be considered acceptable. To keep th…
Recent advances in upscalable wet methods and ink formulations for printed electronics
2014
This review deals with the use of solution processing approaches for organic electronics with a focus on material ink formulations as well as on their applicability. The solution processing techniques include methods like gravure printing, screen printing and ink-jet printing. Basic principles of each approach are understood and fundamental correlations between material (metals, semiconductors, and dielectrics) ink properties and final device performances can be drawn. Nevertheless, solution processing methods have the potential to evolve as the most promising tools in organic device fabrication techniques and have already been applied successfully in the fields of organic thin film transis…
Photoelectrical properties of thin films of DMABI derivatives
2011
Organic thin films with semiconducting properties have been intensively studied in nowadays due to very promising applications in organic electronics, for example, organic photovoltaic. Among organic semiconductors, group of indandiones with their photoelectrical properties, thermal and chemical stability are good candidates for use in design of novel molecular electronic devices. We have investigated photoconductivity quantum efficiency and its spectral dependence of two dimetilaminobenzylidene-1,3-indandione derivatives. Values of the photoconductivity threshold energy and optical energy gap are obtained. These results are compared with calculated transfer energy gap estimated according t…
Cultural intelligence, global mindset, and cross-cultural competencies: a systematic review using bibliometric methods
2020
We conducted a systematic review of 158 publications on Cultural Intelligence (CQ) and related concepts, Global Mindset (GM), and Crosscultural Competence (CC) using bibliometric methods. We apply citation analysis to highlight the most influential (in terms of citations) journals, publications, and specific researchers in the field. We apply factor and cluster analyses to analyse co-citations to identify the current knowledge structure in the research field. With content coding on the resulting groups of co-citations, we identify five research streams showing the overlap between the CQ, GM, and CC constructs, and also revealing the separations in the research on the constructs. We perform …
A longitudinal person-centred approach to the job demands-control model
2016
We used a longitudinal design and a person-centred methodology to test the strain and learning hypotheses of the job demands–control model among Finnish employees (n = 926), who were followed-up at three time points covering a period of 2 years (2008–2010). First, we identified longitudinal subgroups in demands and control across three measurement points. Second, we examined how these subgroups differed in strain (job exhaustion) and motivation-related outcomes (vigour at work, work–family enrichment). Growth mixture modelling revealed four subgroups: “stable high strain”, “stable low strain”, “increasing control”, and “decreasing control”. The stable high- and low-strain subgroups also dif…
El viaje desde los cuestionarios Likert a los cuestionarios de elección forzosa: evidencia de la invarianza de los parámetros de los ítems
2019
Multidimensional forced-choice questionnaires are widely regarded in the personnel selection literature for their ability to control response biases. Recently developed IRT models usually rely on the assumption that item parameters remain invariant when they are paired in forced-choice blocks, without giving it much consideration. This study aims to test this assumption empirically on the MUPP-2PL model, comparing the parameter estimates of the forced-choice format to their graded-scale equivalent on a Big Five personality instrument. The assumption was found to hold reasonably well, especially for the discrimination parameters. In the cases in which it was violated, we briefly discuss the …