569 research outputs found

    Exact treatment of dispersion relations in pp and p\=p elastic scattering

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    Based on a study of the properties of the Lerch's transcendent, exact closed forms of dispersion relations for amplitudes and for derivatives of amplitudes in pp and p\=p scattering are introduced. Exact and complete expressions are written for the real parts and for their derivatives at t=0t=0 based on given inputs for the energy dependence of the total cross sections and of the slopes of the imaginary parts. The results are prepared for application in the analysis of forward scattering data of the pp and p\=p systems at all energies, where exact and precise representations can be written.Comment: 23 pages, 1 figur

    Revisión de los elementos de ajuar conservados del sepulcro megalítico de Unón (Clavijo, La Rioja)

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    En este artículo se procede a la revisión de los materiales conservados del megalito desaparecido de Uñón (Clavijo, La Rioja), entre los que destacan varios recipientes campaniformes

    El ajuar doméstico en el poblado protohistórico de El Castejón de Bargota, Navarra

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    En este trabajo se ofrecen los resultados de las actividades de campo llevadas a cabo en el yacimiento protohistórico de El Castejón, y del posterior estudio de los datos recuperados, tanto de las estructuras, como del ajuar

    Modeling seismic wave propagation and amplification in 1D/2D/3D linear and nonlinear unbounded media

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    To analyze seismic wave propagation in geological structures, it is possible to consider various numerical approaches: the finite difference method, the spectral element method, the boundary element method, the finite element method, the finite volume method, etc. All these methods have various advantages and drawbacks. The amplification of seismic waves in surface soil layers is mainly due to the velocity contrast between these layers and, possibly, to topographic effects around crests and hills. The influence of the geometry of alluvial basins on the amplification process is also know to be large. Nevertheless, strong heterogeneities and complex geometries are not easy to take into account with all numerical methods. 2D/3D models are needed in many situations and the efficiency/accuracy of the numerical methods in such cases is in question. Furthermore, the radiation conditions at infinity are not easy to handle with finite differences or finite/spectral elements whereas it is explicitely accounted in the Boundary Element Method. Various absorbing layer methods (e.g. F-PML, M-PML) were recently proposed to attenuate the spurious wave reflections especially in some difficult cases such as shallow numerical models or grazing incidences. Finally, strong earthquakes involve nonlinear effects in surficial soil layers. To model strong ground motion, it is thus necessary to consider the nonlinear dynamic behaviour of soils and simultaneously investigate seismic wave propagation in complex 2D/3D geological structures! Recent advances in numerical formulations and constitutive models in such complex situations are presented and discussed in this paper. A crucial issue is the availability of the field/laboratory data to feed and validate such models.Comment: of International Journal Geomechanics (2010) 1-1

    Structure of Forward pp and p\=p Elastic Amplitudes at Low Energies

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    Exact analytical forms of solutions for Dispersion Relations for Amplitudes and Dispersion Relations for Slopes are applied in the analysis of pp and ppˉ\rm {p \bar p} scattering data in the forward range at energies below \sqrt(s)\approx 30 \GeV. As inputs for the energy dependence of the imaginary part, use is made of analytic form for the total cross sections and for parameters of the tt dependence of the imaginary parts, with exponential and linear factors. A structure for the tt dependence of the real amplitude is written, with slopes BRB_R and a linear factor ρμRt\rho-\mu_R t that allows compatibility of the data with the predictions from dispersion relations for the derivatives of the real amplitude at the origin. A very precise description is made of all dσ/dtd\sigma/dt data, with regular energy dependence of all quantities. It is shown that a revision of previous calculations of total cross sections, slopes and ρ\rho parameters in the literatures is necessary, and stressed that only determinations based on dσ/dtd\sigma/dt data covering sufficient tt range using appropriate forms of amplitudes can be considered as valid.Comment: 28 pages and 26 figure

    New properties of the Lerch's transcendent

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    A new representation of the Lerch''s transcendent F(z, s, a), valid for positive integer s=n=1, 2, … and for z and a belonging to certain regions of the complex plane, is presented. It allows to write an equation relating F(z, n, a) and F(1/z, n, 1-a), which in turn provides an expansion of F(z, n, a) as a power series of 1/z, convergent for |z|>1

    El depósito de armas de la azucarera (Alfaro, La Rioja)

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    En el presente artículo se trata el hallazgo de un depósito de armas: espadas, puñal, casco y umbos de escudo, principalmente, localizados durante la excavación realizada en el año 1969 en la Azucarera de Alfaro (La Rioja). El material es bastante significativo dentro del contexto peninsular. Parece tratarse de un depósito ritual de la guerra sertoriana, de ahí su importancia y el interés de su publicación

    Conocimientos de las enfermeras acerca de los cuidados paliativos en un área de críticos

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    Introducción y objetivos: Los pacientes que ingresan en las áreas de críticos (AC) tienen alta tasa de morbi-mortalidad debido a su complejidad. Los cuidados paliativos (CP) se presentan como un componente clave y pueden ayudar a mejorar el cuidado del paciente. La enfermera es esencial para la administración de estos cuidados; para ello, es necesario tener formación y saber integrarlos en la práctica diaria. El objetivo fue examinar el nivel de conocimientos de las enfermeras del AC acerca de los CP, y evaluar si existe asociación entre cada una de las variables estudiadas. Metodología: Estudio observación al descriptivo transversal en el AC de un hospital universitario de nivel terciario. Se utilizó el cuestionario Palliative Care Quiz for Nurses, traducido y validado al español. Es un cuestionario auto-administrado que consta de 20 ítems de respuesta múltiple (verdadero/falso/no sabe-no contesta)que evalúa tres aspectos de los CP: filosofía, psicosocial, y control del dolor y otros síntomas. Además, se recogieron datos socio demográficos. Se realizó estadística descriptiva e inferencial, considerándose estadísticamente significativo un valor de p<0,05 en todos los casos. Resultados: El cuestionario se administró a 68 enfermeras, con una edad media de 34,98 ± 12,12 anos, ˜ y 13,00 ± 11,75 anos ˜ de experiencia profesional. Doce enfermeras tenían formación de Máster y 28 enfermeras habían recibido formación en CP. El porcentaje de aciertos del cuestionario fue de 56,98%. No hubo diferencias estadísticamente significativas entre la puntuación media total y las variables estudiadas. Al analizar los aspectos de la escala, se encontró asociación entre la formación en paliativos y el control de síntomas (p = 0,033). Conclusión: Las enfermeras del AC tienen un conocimiento básico sobre los CP, siendo el aspecto psicosocial del mismo insuficiente. Un programa de formación que identifique conceptos erróneos y déficits formativos podría mejorar el control de síntomas de los pacientes que reciben CP, la calidad de estos cuidados y su integración.Abstract Introduction and objetive: Patients admitted to the Critical Care Unit (CCU) have a high mortality rate due to their complexity. Palliative care (PC) is a key aspect that can improve patient care. Because of the essential role of the nurse in providing this care, training, and including it in daily practice are needed. Our objective was to review the level of knowledge among the nurses in the CCU regarding PC and assess whether there is an association between each of the study variables. Methodology: We performed a descriptive observational cross-sectional study in the CCU of a tertiary level university hospital. The questionnaire Palliative Care Quiz for Nurses, previously validated and translated into Spanish, was used. This is a self-administered questionnaire consisting of 20 multiple-choice questions (True/False/Do not Know-Do not answer) which evaluates three aspects of PC: philosophy, psychosocial and control of pain and other symptoms. In addition, sociodemographic data was collected. Descriptive and inferential statistics were used, a p < .05 was considered statistically significant in all cases. Results: The questionnaire was administered to 68 nursers, with an average age of 34.98 ± 12.12 years, and 13.00 ± 11.75 years of professional experience. Twelve nurses have Master studies and 28 nurses have received training in PC. The percent of correct answers of the questionnaire was 56.98%. There were no statistically significant differences between the total average score and the variables studied. However, looking at each aspect on the scale, an association was found between PC training and control of pain and other symptoms (p = .033). Conclusion: Critical care nurses have a basic knowledge of PC, it being insufficientin the psychological sphere. Developing a training programme which identifies misconceptions and training deficits might improve the management of symptom control in palliative care patients, quality of care and its application

    A Simplified Elastic Model for Seismic Analysis of Earth-Retaining Structures with Limited Displacements

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    A simplified elastic model for analyzing static and dynamic interaction between earth-retaining structures and backfill within the range of small displacements is presented. The postulated model covers some of the available models as special cases. The model lends itself readily to the treatment of non-homogeneous backfills with elastic properties varying with depth. Internal (linear) damping in the backfill can be included without impairing the simplicity of the model. Radiation losses due to waves propagating horizontally in fills of semi-infinite extent are inherent to the postulated model. The solutions for some statical and dynamical problems of practical importance show satisfactory agreement with results based on the classical theory of elasticity

    Cerámicas, Estilo y Neolitización: estudio comparativo de algunos ejemplos de la Meseta Norte y Alto Valle del Ebro

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    El estudio de las colecciones cerámicas de diversos yacimientos situados en el entorno de Alto Ebro y la Meseta Norte permite aproximarnos a la caracterización de las primeras producciones cerámicas en esta área del interior peninsular. En base a ello, se proponen dos horizontes cronológicos consecutivos caracterizados por formas diferentes de decorar las cerámicas
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