653 research outputs found
Study of the Indentation Process under Specific Technological Parameters
AbstractThere is a large variety of Compressive Forming Processes with different typologies and characteristics. In this paper, the indentation process is studied from the point of view of manufacturing. The influence of technological parameters such as friction and shape factor on the process has been studied. The aluminum alloy AA 6082 has been employed in this study due to its good mechanical properties, light weight and its capacity of being recycled. The Finite Element Method (FEM) has been used for the analysis. The indentation process has been studied under axisymmetric conditions. The forces to carry out the indentation process and the contact pressures have been obtained. Finally, it is shown that the forces and the contact pressures do not have a high dependency on the friction between the surfaces of the punch and the workpiece. The shape factor has a greater influence on the process, especially the width of the workpiece
Study of the Indentation Process under Specific Technological Parameters
AbstractThere is a large variety of Compressive Forming Processes with different typologies and characteristics. In this paper, the indentation process is studied from the point of view of manufacturing. The influence of technological parameters such as friction and shape factor on the process has been studied. The aluminum alloy AA 6082 has been employed in this study due to its good mechanical properties, light weight and its capacity of being recycled. The Finite Element Method (FEM) has been used for the analysis. The indentation process has been studied under axisymmetric conditions. The forces to carry out the indentation process and the contact pressures have been obtained. Finally, it is shown that the forces and the contact pressures do not have a high dependency on the friction between the surfaces of the punch and the workpiece. The shape factor has a greater influence on the process, especially the width of the workpiece
Análisis químico de muestras minoritarias por procedimientos no destructivos, FRX, de útiles metálicos de la edad del bronce del sureste español
En el presente trabajo se expone las earaeterísticas prineipales de un nuevo
sistema de toma de muestras y su portamuestras. eon objeto de emplearlo en el
análisis químici^ de muestras arqueológieas. empleando 0.2 g eomo máximo, con
lo que se conserva la integridad del objeto analizado. En este caso se utiliza un
espectrómetro .seeuencial Philips PW1400. de tluorcseencia de rayos X. El ci
tado mcttKlo et>nsigue altas cotas de Habilidad y exactitud en los elementos quí
micos elegidos para su análisis
Numerical Solutions of Matrix Differential Models using Cubic Matrix Splines II
This paper presents the non-linear generalization of a previous work on
matrix differential models. It focusses on the construction of approximate
solutions of first-order matrix differential equations Y'(x)=f(x,Y(x)) using
matrix-cubic splines. An estimation of the approximation error, an algorithm
for its implementation and illustrative examples for Sylvester and Riccati
matrix differential equations are given.Comment: 14 pages; submitted to Math. Comp. Modellin
Propiedades Psicométricas del “Sport Motivation Scale” adaptado a la Danza.
El objetivo de esta investigación fue analizar las propiedades psicométricas de la versión en castellano del SMS adaptado a la Danza en su versión de 3, 5 y 7 factores. Se utilizó una muestra de 174 alumnos (165 de sexo femenino=94,8%; 9 de sexo masculino=5,2%) con edades comprendidas entre 10-17 años (M=11,37; DT=,862).Todos los alumnos pertenecen a los cinco Conservatorios Profesionales de Danza en Andalucía de las provincias de Granada, Almería, Cádiz, Córdoba y Sevilla. Como instrumento se utilizó la escala Sport Motivation Scale validada al castellano y para Educación Física adaptándola a la Danza, así como algunos datos sociodemográficos. Se analizaron las propiedades psicométricas de esta escala junto a un análisis exploratorio y confirmatorio en sus tres versiones. Los análisis apoyan que los tres modelos podrían ser utilizados según los datos del análisis factorial exploratorio, aunque sugerimos como mejor opción el modelo de siete factores en el ámbito de la Danza
Characterization of NADH dehydrogenases of Pseudomonas fluorescens WCS365 and their role in competitive root colonization
Microbial Biotechnolog
Changes in flavonoid content of grapefruit juice caused by thermal treatment and storage
The effect of conventional and microwave pasteurization on the main flavonoids present in grapefruit juice and their stability throughout 2 months of refrigerated and frozen storage was evaluated. Individual flavonoids were analyzed by HPLC. The results showed that naringin, narirutin, quercetin and naringenin were the most abundant flavonoids in grapefruit juice. In general, although every pasteurization treatment caused a significant reduction in the content of all the studied flavonoids, the treated samples were more stable during storage. While fresh squeezed juice (FS) and conventional pasteurized juice (CP) were better preserved under refrigeration conditions, microwave pasteurized juice (MP) conserved better when frozen stored. In fact, after 2 months, frozen MP samples showed the greatest flavonoid retention. From this point of view, microwave treatment can be considered a good alternative to conventional pasteurization. Industrial relevance: Flavonoids are polyphenolic compounds present in fruits and vegetables relevant not only in terms of quality, as they influence the visual appearance and taste, but also from a therapeutical point of view, as they appear to be associated with the prevention of degenerative diseases. The consumption of grapefruit juice is fairly widespread among the population. Traditionally, juices have been pasteurized by heat treatment to prolong their shelf life. However, this process may cause irreversible losses of nutritional quality and antioxidant activity and, in consequence, may affect their health-related properties. In this sense, the use of microwaves can be considered an alternative to conventional thermal pasteurization. Microwave energy was applied as alternative to conventional heating for grapefruit juice pasteurization. The results obtained in this study showed that when the effect of pasteurization process and storage is considered together, the use of microwave energy led to a greater retention of all the analyzed flavonoids, thereby representing a good alternative to conventional pasteurization. In this case, frozen storage of processed product would be recommended to better preserve these compounds. © 2011 Elsevier Ltd. All rights reserved.The authors wish to thank the Ministerio de Educacion y Ciencia and FEDER for their financial support throughout the Project AGL 2005-05994.Igual Ramo, M.; García Martínez, EM.; Camacho Vidal, MM.; Martínez Navarrete, N. (2011). Changes in flavonoid content of grapefruit juice caused by thermal treatment and storage. Innovative Food Science and Emerging Technologies. 12(2):153-162. https://doi.org/10.1016/j.ifset.2010.12.010S15316212
Effects of drying and pretreatment on the nutritional and functional quality of raisins
The close relationship between the consumption of fruits and health status stems from the nutritional and non-nutritional compounds found in fruits which play a key role in the prevention of different diseases. However, fruit processing and storage greatly affect fruit compounds. The aim of the present work was to study the influence of processing on the stability of macro and micronutrients present in grapes, with a view to recommending products that provide the highest nutritional quality and the best health conditions. The study focused on fruit dehydration treatments. Conventional and microwave-assisted air-drying processes were used to obtain raisins. Dehydration caused a decrease of all grape compounds studied excluding total phenols. Moreover, compared to conventional processing, microwave-assisted drying produced greater losses of ascorbic acid in the grape and increased pectin solubilization with a consequent change in texture. However the microwave-dehydrated samples showed higher antioxidant activity. © 2011 The Institution of Chemical Engineers.The translation of this paper was funded by the Universidad Politecnica de Valencia.Carranza Concha, J.; Benlloch Tinoco, M.; Camacho Vidal, MM.; Martínez Navarrete, N. (2012). Effects of drying and pretreatment on the nutritional and functional quality of raisins. Food and Bioproducts Processing. 90(2):243-248. https://doi.org/10.1016/j.fbp.2011.04.002S24324890
Deep exclusive electroproduction off the proton at CLAS
The exclusive electroproduction of above the resonance region was
studied using the Large Acceptance Spectrometer () at
Jefferson Laboratory by scattering a 6 GeV continuous electron beam off a
hydrogen target. The large acceptance and good resolution of ,
together with the high luminosity, allowed us to measure the cross section for
the process in 140 (, , ) bins:
, 1.6 GeV GeV and 0.1 GeV
GeV. For most bins, the statistical accuracy is on the order of a few
percent. Differential cross sections are compared to two theoretical models,
based either on hadronic (Regge phenomenology) or on partonic (handbag diagram)
degrees of freedom. Both can describe the gross features of the data reasonably
well, but differ strongly in their ingredients. If the handbag approach can be
validated in this kinematical region, our data contain the interesting
potential to experimentally access transversity Generalized Parton
Distributions.Comment: 18pages, 21figures,2table
Improvement in detecting cytomegalovirus drug resistance mutations in solid organ transplant recipients with suspected resistance using next generation sequencing
Objetives
The aim of this study was to identify CMV drug resistance mutations (DRM) in solid organ transplant (SOT) recipients with suspected resistance comparing next-generation sequencing (NGS) with Sanger sequencing and assessing risk factors and the clinical impact of resistance.
Methods
Using Sanger sequencing as the reference method, we prospectively assessed the ability of NGS to detect CMV DRM in the UL97 and UL54 genes in a nationwide observational study from September 2013 to August 2016.
Results
Among 44 patients recruited, 14 DRM were detected by Sanger in 12 patients (27%) and 20 DRM were detected by NGS, in 16 (36%). NGS confirmed all the DRM detected by Sanger. The additional six mutations detected by NGS were present in <20% of the sequenced population, being located in the UL97 gene and conferring high-level resistance to ganciclovir. The presence of DRM by NGS was associated with lung transplantation (p = 0.050), the administration of prophylaxis (p = 0.039), a higher mean time between transplantation and suspicion of resistance (p = 0.038) and longer antiviral treatment duration before suspicion
(p = 0.024). However, the latter was the only factor independently associated with the presence of DRM by NGS in the multivariate analysis (OR 2.24, 95% CI 1.03 to 4.87).
Conclusions
NGS showed a higher yield than Sanger sequencing for detecting CMV resistance mutations in SOT recipients. The presence of DRM detected by NGS was independently associated with longer antiviral treatment.Funding: M.A.M. was supported in part by: Agency for Health Technology Assessment and Research Supported by Ministerio de Economía y Competitividad, Instituto de Salud Carlos III (PS12/02131 and PI17/02150); Agència de Gestió d´Ajuts Universitaris I de Recerca, Generalitat de
Catalunya, 2017 SGR 794; and Fundació Marató TV3 project code 201824
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