Numerical evaluation of the vibration reduction index for structural joints

The present paper addresses the analysis of structural vibration transmission in the presence of structural joints. The problem is tackled from a numerical point of view, analyzing some scenarios by using finite element models. The numerical results obtained making use of this process are then compared with those evaluated using the EN 12354 standard vibration reduction index concept. It is shown that, even for the simplest cases, the behavior of a structural joint is complex and evidences the frequency dependence. Comparison with results obtained by empirical formulas reveals that those of the standards cannot accurately reproduce the expected behavior, and thus indicate that alternative complementary calculation procedures are required. A simple methodology to estimate the difference between numerical and standard predictions is here proposed allowing the calculation of an adaptation term that makes both approaches converge. This term was found to be solution-dependent, and thus should be evaluated for each structure.

Measuring color differences in automotive samples with lightness flop: a test of the AUDI2000 color-difference formula

From a set of gonioapparent automotive samples from different manufacturers we selected 28 low-chroma color pairs with relatively small color differences predominantly in lightness. These color pairs were visually assessed with a gray scale at six different viewing angles by a panel of 10 observers. Using the Standardized Residual Sum of Squares (STRESS) index, the results of our visual experiment were tested against predictions made by 12 modern color-difference formulas. From a weighted STRESS index accounting for the uncertainty in visual assessments, the best prediction of our whole experiment was achieved using AUDI2000, CAM02-SCD, CAM02-UCS and OSA-GP-Euclidean color-difference formulas, which were no statistically significant different among them. A two-step optimization of the original AUDI2000 color-difference formula resulted in a modified AUDI2000 formula which performed both, significantly better than the original formula and below the experimental inter-observer variability. Nevertheless the proposal of a new revised AUDI2000 color-difference formula requires additional experimental data.

Relationship between static and dynamic elastic modulus of calcarenite heated at different temperatures: the San Julián's stone

The San Julián’s stone is the main material used to build the most important historical buildings in Alicante city (Spain). This paper describes the analysis developed to obtain the relationship between the static and the dynamic modulus of this sedimentary rock heated at different temperatures. The rock specimens have been subjected to heating processes at different temperatures to produce different levels of weathering on 24 specimens. The static and dynamic modulus has been measured for every specimen by means of the ISRM standard and ultrasonic tests, respectively. Finally, two analytic formulas are proposed for the relationship between the static and the dynamic modulus for this stone. The results have been compared with some relationships proposed by different researchers for other types of rock. The expressions presented in this paper can be useful for the analysis, using non-destructive techniques, of the integrity level of historical constructions built with San Julián’s stone affected by fires.

Minimizing the IOL Power Error Induced by Keratometric Power

Purpose. To evaluate theoretically in normal eyes the influence on IOL power (PIOL) calculation of the use of a keratometric index (nk) and to analyze and validate preliminarily the use of an adjusted keratometric index (nkadj) in the IOL power calculation (PIOLadj). Methods. A model of variable keratometric index (nkadj) for corneal power calculation (Pc) was used for IOL power calculation (named PIOLadj). Theoretical differences ($PIOL) between the new proposed formula (PIOLadj) and which is obtained through Gaussian optics (PIOL Gauss) were determined using Gullstrand and Le Grand eye models. The proposed new formula for IOL power calculation (PIOLadj) was prevalidated clinically in 81 eyes of 81 candidates for corneal refractive surgery and compared with Haigis, HofferQ, Holladay, and SRK/T formulas. Results. A theoretical PIOL underestimation greater than 0.5 diopters was present in most of the cases when nk = 1.3375 was used. If nkadj was used for Pc calculation, a maximal calculated error in $PIOL of T0.5 diopters at corneal vertex in most cases was observed independently from the eye model, r1c, and the desired postoperative refraction. The use of nkadj in IOL power calculation (PIOLadj) could be valid with effective lens position optimization nondependent of the corneal power. Conclusions. The use of a single value of nk for Pc calculation can lead to significant errors in PIOL calculation that may explain some IOL power overestimations with conventional formulas. These inaccuracies can be minimized by using the new PIOLadj based on the algorithm of nkadj.

Measuring color differences in gonioapparent materials used in the automotive industry

This paper illustrates how to design a visual experiment to measure color differences in gonioapparent materials and how to assess the merits of different advanced color-difference formulas trying to predict the results of such experiment. Successful color-difference formulas are necessary for industrial quality control and artificial color-vision applications. A color- difference formula must be accurate under a wide variety of experimental conditions including the use of challenging materials like, for example, gonioapparent samples. Improving the experimental design in a previous paper [Melgosaet al., Optics Express 22, 3458-3467 (2014)], we have tested 11 advanced color-difference formulas from visual assessments performed by a panel of 11 observers with normal colorvision using a set of 56 nearly achromatic colorpairs of automotive gonioapparent samples. Best predictions of our experimental results were found for the AUDI2000 color-difference formula, followed by color-difference formulas based on the color appearance model CIECAM02. Parameters in the original weighting function for lightness in the AUDI2000 formula were optimized obtaining small improvements. However, a power function from results provided by the AUDI2000 formula considerably improved results, producing values close to the inter-observer variability in our visual experiment. Additional research is required to obtain a modified AUDI2000 color-difference formula significantly better than the current one.

Error induced by the estimation of the corneal power and the effective lens position with a rotationally asymmetric refractive multifocal intraocular lens

AIM: To evaluate the prediction error in intraocular lens (IOL) power calculation for a rotationally asymmetric refractive multifocal IOL and the impact on this error of the optimization of the keratometric estimation of the corneal power and the prediction of the effective lens position (ELP). METHODS: Retrospective study including a total of 25 eyes of 13 patients (age, 50 to 83y) with previous cataract surgery with implantation of the Lentis Mplus LS-312 IOL (Oculentis GmbH, Germany). In all cases, an adjusted IOL power (PIOLadj) was calculated based on Gaussian optics using a variable keratometric index value (nkadj) for the estimation of the corneal power (Pkadj) and on a new value for ELP (ELPadj) obtained by multiple regression analysis. This PIOLadj was compared with the IOL power implanted (PIOLReal) and the value proposed by three conventional formulas (Haigis, Hoffer Q and Holladay). RESULTS: PIOLReal was not significantly different than PIOLadj and Holladay IOL power (P>0.05). In the Bland and Altman analysis, PIOLadj showed lower mean difference (-0.07 D) and limits of agreement (of 1.47 and -1.61 D) when compared to PIOLReal than the IOL power value obtained with the Holladay formula. Furthermore, ELPadj was significantly lower than ELP calculated with other conventional formulas (P<0.01) and was found to be dependent on axial length, anterior chamber depth and Pkadj. CONCLUSION: Refractive outcomes after cataract surgery with implantation of the multifocal IOL Lentis Mplus LS-312 can be optimized by minimizing the keratometric error and by estimating ELP using a mathematical expression dependent on anatomical factors.

Nutrición enteral en el estado nutricional del cáncer; revisión sistemática

Objetivo: identificar qué efecto provoca la nutrición enteral en el estado nutricional del cáncer. Método: se realizó una búsqueda con las palabras clave “Cancer” AND “Enteral Nutrition” AND “Supplementation” en cuatro bases de datos documentales: Pubmed, EBSCO, ProQuest y Web of Science. Criterios de inclusión: edad de la muestra, mayores de 18 años; el programa de intervención incluía dieta y empleo o no de suplementación nutricional; ensayos clínicos publicados entre enero de 2004 y diciembre de 2014, en revistas científicas indexadas. Resultados: se han analizado 660 artículos, de los cuales solo han sido incluidos un 2%. El 58% de los programas de intervención son aplicados fuera de España; el 84% de las intervenciones fueron llevadas a cabo en un ambiente hospitalario; el 58% de la muestra está formada por adultos mayores de 54 años; el 33% de las intervenciones fueron multidisciplinares y su duración oscila entre 1 y 4 años. Discusión: se han encontrado pocas intervenciones a nivel nacional y se diferencian en dos tipos: fórmula enteral polimérica exclusiva o mixta junto a inmunonutrición. Conclusión: la nutrición enteral frente a la parenteral y su introducción de forma precoz mejora el estado nutricional del paciente; las fórmulas poliméricas junto a la inmunonutrición ayudan a la reducción del tiempo de hospitalización; los parámetros analíticos se muestran como un patrón de medición a la hora de valorar la mejora en el estado nutricional de los pacientes con cáncer. Se recomienda aumentar la investigación en este campo, sobre todo en niños.

Agua, derecho de uso y utilidad en el regadío de tradición andalusí del Reino de Valencia

El origen de la normativa escrita sobre el uso de las aguas en el territorio peninsular levantino plantea diversas incógnitas. Las primera de ellas sobre los quienes fueron los protagonistas en la redacción y determinación de ese derecho. La segunda sobre el papel que la costumbre de los sarracenos desempeñó en la preservación de tradiciones jurídicas, mantenimiento de infraestructuras y gestión del agua. La tercera tiene que ver con el modo de aunar intereses de comunidades distintas desde el punto de vista religioso y jurídico sobre el derecho de uso de forma equitativa y proporcional a necesidades no necesariamente coincidentes. Lo cierto es que las fuentes conservadas sobre el proceso de reconquista y población siguen siendo una de las mejores referencias para despejar incógnitas y justificar la tradición y pervivencia de un derecho inmemorial y vigente en algunas de sus formas y manifestaciones, no solo en el marco levantino sino en otros muchos espacios de la cuenca mediterránea con idénticas características medioambientales y geo-climáticas.

Phraseological features in conversational routines: An integrative model of autonomy

This paper deals with the analysis of routine formulas according to their degree of independence in discourse, with the aim of establishing a gradual line which restructures Sphere III (Corpas 1996, Alvarado 2015) — where phraseological utterances belong. The system developed by Briz and the Val.Es.Co. Group (2003, 2014) will help us segment conversation and check that phraseological utterances show various degrees of independence, both in Peninsular Spanish and in Latin American Spanish, which will make it possible to restructure Sphere III. The methodology utilized corresponds to the phraseological and pragmatic approach, and the examples were extracted from the Corpus de Conversaciones Coloquiales of Briz and the Val.Es.Co. Group (2002), and from the Corpus Preseea (2014).

Positional accommodative intraocular lens power error induced by the estimation of the corneal power and the effective lens position

Purpose: To evaluate the predictability of the refractive correction achieved with a positional accommodating intraocular lenses (IOL) and to develop a potential optimization of it by minimizing the error associated with the keratometric estimation of the corneal power and by developing a predictive formula for the effective lens position (ELP). Materials and Methods: Clinical data from 25 eyes of 14 patients (age range, 52–77 years) and undergoing cataract surgery with implantation of the accommodating IOL Crystalens HD (Bausch and Lomb) were retrospectively reviewed. In all cases, the calculation of an adjusted IOL power (PIOLadj) based on Gaussian optics considering the residual refractive error was done using a variable keratometric index value (nkadj) for corneal power estimation with and without using an estimation algorithm for ELP obtained by multiple regression analysis (ELPadj). PIOLadj was compared to the real IOL power implanted (PIOLReal, calculated with the SRK-T formula) and also to the values estimated by the Haigis, HofferQ, and Holladay I formulas. Results: No statistically significant differences were found between PIOLReal and PIOLadj when ELPadj was used (P = 0.10), with a range of agreement between calculations of 1.23 D. In contrast, PIOLReal was significantly higher when compared to PIOLadj without using ELPadj and also compared to the values estimated by the other formulas. Conclusions: Predictable refractive outcomes can be obtained with the accommodating IOL Crystalens HD using a variable keratometric index for corneal power estimation and by estimating ELP with an algorithm dependent on anatomical factors and age.

Pharmacopea de la Armada (1760), un libro singular para uso de los sanitarios navales del siglo XVIII

La Pharmacopea de la Armada, obra de Leandro de Vega, publicada en 1760 para uso de médicos y cirujanos de los buques y hospitales de la marina española a lo largo del siglo XVIII, está considerada como la primera farmacopea naval española. Su autor la define con un «catálogo de medicamentos pertenecientes a las enfermedades médicas», en definitiva un nomenclátor de fórmulas para la preparación de los medicamentos de mayor utilidad para los navegantes de la época, tanto de uso interno como externo. En el presente artículo se analiza en profundidad esta obra, reconocida su relevancia de fuente primaria, situándola en su contexto histórico, detallando el contenido de sus tratados, así como dando noticia biográfica de su autor e informando de la posición profesional y misión de sus destinatarios.

Cálculo del asiento elástico tridimensional de cimentaciones de rigidez variable en terrenos con una capa rígida inclinada

Las fórmulas basadas en la teoría de la elasticidad son ampliamente utilizadas para el cálculo de asientos de cimentaciones, ya que la totalidad de la normativa geotécnica recomienda su empleo. No obstante, estos métodos no cubren todas las situaciones geotécnicamente posibles ya que frecuentemente las condiciones geológicas son complejas. En este trabajo se analiza la influencia de la presencia de una capa rígida inclinada en los asientos elásticos de una cimentación superficial. Para ello se han resuelto 273 modelos tridimensionales no lineales de elementos finitos, variando los parámetros clave del problema: la inclinación y la profundidad de la capa rígida y la rigidez de la cimentación. Finalmente, se ha realizado un análisis estadístico de los resultados de los modelos y se ha propuesto una fórmula que puede ser utilizada en el cálculo de asientos por métodos elásticos, para tener en consideración la presencia de una capa rígida inclinada en profundidad.