Search results for "Computer program"
showing 10 items of 807 documents
Using Induced Ordered Weighted Averaging (IOWA) Operators for Aggregation in Cross-Efficiency Evaluations
2014
This paper proposes an enhancement of the cross-efficiency evaluation through the aggregation of cross-efficiencies by using a particular type of induced ordered weighted averaging IOWA operator. The use of a weighted average of cross-efficiencies for the calculation of the cross-efficiency scores, instead of the usual arithmetic mean, allows us to introduce some flexibility into the analysis. In particular, the main purpose of the approach we present is to provide aggregation weights that reflect the decision maker DM preferences regarding the relative importance that should be attached to the cross-efficiencies provided by the different decision-making units. To do it, an ordering is to b…
Helical Shift Mechanics of Rubber V-Belt Variators
2011
A very common configuration of V-belt variators for motorcycles considers the correction of the belt tensioning depending on the resistant torque by means of suitable helical-shaped tracks allowing the driven half-pulleys to close/open. The theoretical model for belt-pulley coupling is rather complex for this configuration, where one half-pulley may run in advance and the other one behind with respect to the belt, and requires the repeated numerical solution of a strongly nonlinear differential system by a sort of shooting technique, until all the operating conditions are fulfilled (angular contact extent, torque, and axial force). After solving the full equations, the present study develop…
Speciation of tin(II) in aqueous solution: thermodynamic and spectroscopic study of simple and mixed hydroxocarboxylate complexes
2013
This contribution reports the results of potentiometric and Mossbauer investigations on the formation, stability, and structure of binary and ternary mono- and binuclear complexes of Sn2+ with three hydroxocarboxylic ligands (namely L = tartrate, malate, and citrate) and chloride at T = 298.15 K in different ionic media and ionic strengths (0.15 and 1.00 mol dm−3 in NaCl(aq) and 1.00 mol dm−3 in NaNO3(aq)). The stability constants of various simple Sn i H j L (2+−) and mixed Sn i H j L k Cl (2+−−) species obtained in the different experimental conditions are reported, and various speciation diagrams of the simple and mixed systems are shown in different conditions. The sequestering ability …
Ethanol-Based Post-processing of Generator-Derived 68Ga Toward Kit-Type Preparation of 68Ga-Radiopharmaceuticals
2014
Post-processing by means of a cation-exchanger–based protocol is an efficient strategy for purification and concentration of generator-derived 68Ga. It ensures the removal of 68Ge before 68Ga-radiopharmaceutical preparation and high labeling yields of 68Ga-labeled radiopharmaceuticals for routine medical application. Methods: In an effort to overcome the problem associated with acetone in the currently applied method, we have investigated the feasibility of replacing it with ethanol. The purification of 68Ga from coeluted metallic impurities (68Ge4+, Fe3+, Zn2+, and Ti4+) on various cation-exchange columns has been investigated with a variety of post-processing solutions. As a proof of prin…
The Renaissance of the 68Ge/68Ga Radionuclide Generator Initiates New Developments in 68Ga Radiopharmaceutical Chemistry
2010
⁶⁸Ge/⁶⁸Ga radionuclide generators have been investigated for almost fifty years now, since the cyclotron-independent availability of positron emitting ⁶⁸Ga via the ⁶⁸Ge/⁶⁸Ga system had always attracted researches working in basic nuclear chemistry as well as radiopharmaceutical chemistry. However, it took decades and generations of research (and researchers) to finally approach a reliable level of ⁶⁸Ge/⁶⁸Ga generator designs, adequate to the modern requirements of radiometal labeling chemistry. ⁶⁸Ga radiopharmacy now is awaking from a sort of hibernation. The exciting perspective for the ⁶⁸Ge/⁶⁸Ga generator, now - more than ever, asks for systematic chemical, radiochemical, technological an…
Improved column-based radiochemical processing of the generator produced 68Ga.
2011
An improved chemical strategy for processing of the generator produced (68)Ga was developed based on processing of the original (68)Ge/(68)Ga generator eluate on a micro-column. Direct pre-concentration and purification of the eluted (68)Ga is performed on a cation-exchange resin in hydrochloric acid/acetone media. A supplementary step based on a second micro-column filled with a second resin allows direct re-adsorption of (68)Ga eluted from the cation exchanger. (68)Ga is finally striped from the second resin with a small volume of pure water. For this purpose a strong anion exchanger and a novel extraction chromatographic resin based on tetraalkyldiglycolamides are characterized. The stra…
Maturation of a Key Resource – The Germanium-68/Gallium-68 Generator: Development and New Insights
2011
(68)Ge/(68)Ga radionuclide generators have been investigated for almost fifty years, since the cyclotron-independent availability of positron emitting (68)Ga via the (68)Ge/(68)Ga system had always attracted researches working in basic nuclear chemistry as well as radiopharmaceutical chemistry. However, it took decades and generations of research (and researchers) to finally reach a level of (68)Ge/(68)Ga radionuclide generator designs adequate to the modern requirements of radiometal labelling chemistry. Nevertheless, most of the existing commercial generator systems address aspects of (68)Ge breakthrough and safe synthesis of (68)Ga radiopharmaceuticals by adopting eluate post-processing …
Revista iberoamericana de educación
2012
Título, resumen y palabras clave en español, portugués e inglés Monográfico con el título: "Didáctica de la Lengua y la Literatura" Resumen tomado de la publicación Se propone el examen de las implicaciones del concepto de género discursivo, tomado de M. Bajtín, para la enseñanza de la composición escrita dentro del marco metodológico de las secuencias didácticas. Además de situar la enseñanza en un marco comunicativo, integra los aprendizajes específicos de habilidades lingüístico-comunicativas dentro de una tarea global que les da sentido. Se destaca de un modo especial la importancia de esta integración en cuanto a los conocimientos explícitos sobre la lengua y sus condiciones de uso. Se…
Spatialization of the Semantic Web
2012
syntax for Horn-like rules. The SWRL as the form, antecedentconsequent, where both antecedent and consequent are conjunctions of atoms written a1^ ... ^ an. Atoms in rules can be of the form C(x), P(x,y), Q(x,z), sameAs(x,y), differentFrom(x,y), or builtIn(pred, z1, ..., zn), where C is an OWL description, P is an OWL individual-valued property, Q is an OWL data-valued property, pred is a datatype predicate URIref, x and y are either individual-valued variables or OWL individuals, and z, z1, ... zn are either data-valued variables or OWL data literals. An OWL data literal is either a typed literal or a plain literal. Variables are indicated by using the standard convention of prefixing the…
School principals’ point of view on pupils’ participation
2021
La participación es un derecho que los niños y niñas deben tener la oportunidad de ejercer y la escuela es un escenario idóneo para que el alumnado pueda hacer oír su voz exponiendo ideas, tomando decisiones y formulando propuestas. Con el objetivo de detectar las opciones del alumnado de participar en el centro y apuntar vías para maximizarlas efectuamos un estudio a partir de un cuestionario elaborado ad hoc dirigido a todos y todas los directores y directoras de escuelas de Cataluña. En concreto, participaron 684 y los resultados indican que los niños y las niñas no solo opinan en clase, sino que toman decisiones cuando trabajan en grupo, en relación con la convivencia o votando sus prop…