240 research outputs found
Hermitian clifford analysis
This paper gives an overview of some basic results on Hermitian Clifford analysis, a refinement of classical Clifford analysis dealing with functions in the kernel of two mutually adjoint Dirac operators invariant under the action of the unitary group. The set of these functions, called Hermitian monogenic, contains the set of holomorphic functions in several complex variables. The paper discusses, among other results, the Fischer decomposition, the Cauchy–Kovalevskaya extension problem, the axiomatic radial algebra, and also some algebraic analysis of the system associated with Hermitian monogenic functions. While the Cauchy–Kovalevskaya extension problem can be carried out for the Hermitian monogenic system, this system imposes severe constraints on the initial Cauchy data. There exists a subsystem of the Hermitian monogenic system in which these constraints can be avoided. This subsystem, called submonogenic system, will also be discussed in the paper
Cauchy integral and singular integral operator over closed Jordan curves
This paper is mostly a review paper. It contains a description of old and recent results concerning the regularity conditions on a Jordan curve in the plane that imply the boundedness of the singular integral operator as well as the boundary behavior of the Cauchy type integral. These results are of significance for boundary value problems in domains with non-smooth and non-rectifiable boundaries. © 2014 Springer-Verlag Wien
Cauchy integral and singular integral operator over closed Jordan curves
© Springer-Verlag Wien 2014. This paper is mostly a review paper. It contains a description of old and recent results concerning the regularity conditions on a Jordan curve in the plane that imply the boundedness of the singular integral operator as well as the boundary behavior of the Cauchy type integral. These results are of significance for boundary value problems in domains with non-smooth and non-rectifiable boundaries
Integration over non-rectifiable curves and Riemann boundary value problems
In this paper we introduce an alternative way of defining the curvilinear Cauchy integral over non-rectifiable curves in the case of complex functions of one complex variable. Especially the jump behavior on the boundary is considered. As an application, solvability conditions of the Riemann boundary value problem are derived on very weak conditions to the boundary. Besides the complex case the consideration can be extended to the theory of Douglis algebra valued functions. © 2011 Elsevier Inc
Influencia del riego deficitario controlado precosecha sobre la calidad de la cereza ´Prime Giant`
El uso de redes de sensores para el manejo del riego deficitario controlado (RDC) en
cerezo puede incidir en la mejora de la productividad del agua, calidad de la fruta y en su
comportamiento poscosecha, al permitir el conocimiento y control del estado hídrico del
suelo y árbol en todo momento.
En el primer año de ensayo, el riego deficitario aplicado en precosecha para
satisfacer el 85% de las necesidades máximas del cultivo (ETcg) permitió un ahorro de agua
del 17% (380 m3 ha-1) respecto al tratamiento control, que se regó al 110% de la ETcg. Este
déficit hídrico ligero no afectó a la producción (16,13 t ha-1) e incluso mejoró la calidad del
fruto. Así, en el momento de la cosecha (t0) los frutos bajo déficit ligero presentaron matices
más rojos y mayor acidez que los de riego completo. Esta mayor acidez no afectó al índice
de madurez debido a la compensación por sólidos solubles totales (SST). El carácter de
mayor acidez perduró tras 30 días de conservación en frio (t1) y 5 días de simulación de las
condiciones de comercialización (t2). Igualmente, los frutos bajo déficit hídrico presentaron
una tendencia a menores pérdidas de peso por deshidratación a finales de los periodos de
conservación en frio y de simulación de la comercialización.Ministerio de Economía y Competitividad AGL2013-49047-C2-1
Mejora de la calidad de las medidas de ozono mediante un fotómetro UV de referencia
The Directive 92/72/CE makes reference to the analysis method described in the UNE 77-221:2000 and to the fact that the ozone analyzers shall be calibrated with a UV reference photometer or with a transfer standard.From the need of developing a procedure that assure the quality and the trazability of the measurements in Spain, the Atmospheric Pollution Area has decided to implant a NIST UV reference photometer as ozone national standard.Taking into account the procedures used by EPA and NIST, a verification procedure has been developed consistent in the realization of 6 comparisons of the Transfer Standard versus NIST UV reference photometer in different days; at least 5 different ozone concentrations are analyzed. Each comparison begins and ends always with a concentration of 0 ppb of O3, and from each comparison its regression linear is obtained.Once the 6 comparisons are done, the calibration relationship is obtained and the uncertainty associated with the transfer standard is calculated.Until now, the verifications of 17 transfer standards have been done: 11 of them were UV photometers, 2 were ozone generators and 4 were ozone generators of dilution banks.From the results is concluded that generally the uncertainties of the ozone generators are greater than those of the UV photometers, so being recommended this one like transfer standard.To emphasize that with the utilization of the tranfer standards for the calibration of ozone analyzers, the quality and the trazability of the generated data are guaranteed.La Directiva 92/72/CE hace referencia al método de análisis descrito en la UNE 77-221:2000 y a que los analizadores de ozono se deben calibrar con un fotómetro UV de referencia o con un patrón transferido.De la necesidad de desarrollar un procedimiento que asegure la calidad y la trazabilidad de las mediciones en España, el Área de Contaminación Atmosférica ha decidido implantar un fotómetro UV de referencia NIST como patrón de ozono.Teniendo en cuenta los procedimientos empleados por EPA y NIST, se ha desarrollado un procedimiento de verificación consistente en la realización de 6 comparaciones del Patrón Transferido frente al Fotómetro UV de Referencia NIST, en días diferentes, analizándose, como mínimo, 5 concentraciones de ozono diferentes. Cada comparación se inicia y se finaliza siempre con una concentración de 0 ppb de O3. De cada comparación se obtiene una regresión lineal.Una vez realizadas las 6 comparaciones se obtiene la Recta de calibración y se calcula la incertidumbre asociada al patrón transferido.Se ha realizado la verificación de 17 patrones transferidos de los que 11 son fotómetros UV, 2 son generadores de ozono y 4 son generadores de ozono de bancos de dilución.De los resultados se concluye que las incertidumbres de los generadores de ozono, en general, son mayores que las de los fotómetros UV, recomendándose estos últimos como patrones transferidos.Destacar que mediante la utilización de los patrones transferidos para la calibración de analizadores de ozono se garantiza tanto la calidad como la trazabilidad de los datos generados
Diffusion of e-health innovations in 'post-conflict' settings: a qualitative study on the personal experiences of health workers.
BACKGROUND: Technological innovations have the potential to strengthen human resources for health and improve access and quality of care in challenging 'post-conflict' contexts. However, analyses on the adoption of technology for health (that is, 'e-health') and whether and how e-health can strengthen a health workforce in these settings have been limited so far. This study explores the personal experiences of health workers using e-health innovations in selected post-conflict situations. METHODS: This study had a cross-sectional qualitative design. Telephone interviews were conducted with 12 health workers, from a variety of cadres and stages in their careers, from four post-conflict settings (Liberia, West Bank and Gaza, Sierra Leone and Somaliland) in 2012. Everett Roger's diffusion of innovation-decision model (that is, knowledge, persuasion, decision, implementation, contemplation) guided the thematic analysis. RESULTS: All health workers interviewed held positive perceptions of e-health, related to their beliefs that e-health can help them to access information and communicate with other health workers. However, understanding of the scope of e-health was generally limited, and often based on innovations that health workers have been introduced through by their international partners. Health workers reported a range of engagement with e-health innovations, mostly for communication (for example, email) and educational purposes (for example, online learning platforms). Poor, unreliable and unaffordable Internet was a commonly mentioned barrier to e-health use. Scaling-up existing e-health partnerships and innovations were suggested starting points to increase e-health innovation dissemination. CONCLUSIONS: Results from this study showed ICT based e-health innovations can relieve information and communication needs of health workers in post-conflict settings. However, more efforts and investments, preferably driven by healthcare workers within the post-conflict context, are needed to make e-health more widespread and sustainable. Increased awareness is necessary among health professionals, even among current e-health users, and physical and financial access barriers need to be addressed. Future e-health initiatives are likely to increase their impact if based on perceived health information needs of intended users
On the Lebesgue measure of Li-Yorke pairs for interval maps
We investigate the prevalence of Li-Yorke pairs for and
multimodal maps with non-flat critical points. We show that every
measurable scrambled set has zero Lebesgue measure and that all strongly
wandering sets have zero Lebesgue measure, as does the set of pairs of
asymptotic (but not asymptotically periodic) points.
If is topologically mixing and has no Cantor attractor, then typical
(w.r.t. two-dimensional Lebesgue measure) pairs are Li-Yorke; if additionally
admits an absolutely continuous invariant probability measure (acip), then
typical pairs have a dense orbit for . These results make use of
so-called nice neighborhoods of the critical set of general multimodal maps,
and hence uniformly expanding Markov induced maps, the existence of either is
proved in this paper as well.
For the setting where has a Cantor attractor, we present a trichotomy
explaining when the set of Li-Yorke pairs and distal pairs have positive
two-dimensional Lebesgue measure.Comment: 41 pages, 3 figure
Design of a Customized Neck Orthosis for FDM Manufacturing with a New Sustainable Bio-composite
The interest in developing customized external orthopaedic devices,
thanks to the advent of Additive Manufacturing (AM), has grown in recent
years. Greater attention was focused on upper limb casts, while applications to
other body’s parts, such as the neck, were less investigated. In this paper the
computer aided design (CAD) modelling, assessment and 3D printing with
fused deposition modelling (FDM) of a customized neck orthosis are reported.
The modelling, based on anatomic data of a volunteer subject, was aimed to
obtain a lightweight, ventilated, hygienic and comfortable orthosis compared to
the produced medical devices generally used for neck injuries. CAD models
with different geometrical patterns, introduced for lightening and improving
breathability, were considered, specifically, a honeycomb pattern and an elliptical
holes pattern. These models were structurally assessed by means of finite
elements analysis (FEA). Furthermore, an innovative composite material was
considered for 3D printing. The material, Hemp Bio-Plastic® (HBP), composed
by polylactic acid (PLA) and hemp shives, offers different advantages including
lightweight, improved superficial finish and antibacterial properties. The results
obtained in terms of design methodology and manufacturing by 3D printing of a
prototype have shown the feasibility to develop customized cervical orthoses,
with potentially improved performance with respect to cervical collars available
on the market also thanks to the use of the innovative composite material
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