Laser Peening Induced Shock Waves and Cavitation Bubbles in Water Studied by Optical Schlieren Visualization

AbstractA temporal and spatial study of the dynamics of generated shock waves and cavitation bubbles in water by laser peening using nanosecond Nd:YAG laser pulses is reported. False schlieren photographs of the zone surrounding the laser spot on the target were recorded by a fast ICCD camera. The developed experimental setup allowed us to obtain a visualization of the different phenomena (hemispherical, cylindrical and plane shock fronts, cavitation bubbles, phase disturbance tracks, plasma formation, etc.) that occur after the arrival of the laser pulse and that contain valuable information about the mechanical processes that take place on the sample

Angle Dependence of the Transverse Thermal Conductivity in YBa2_2Cu3_3O7_7 single crystals: Doppler Effect vs. Andreev scattering

We have measured the transverse thermal conductivity $\kappa_{xy}$ of twinned and untwinned YBa$_2$Cu$_3$O$_7$ single crystals as a function of angle $\theta$ between the magnetic field applied parallel to the CuO$_2$ planes and the heat current direction, at different magnetic fields and temperatures. For both crystals we observed a clear twofold variation in the field-angle dependence of $\kappa_{xy}(\theta) = - \kappa^0_{xy}(T,B) \sin(2\theta)$. We have found that the oscillation amplitude $\kappa^0_{xy}$ depends on temperature and magnetic field. Our results show that $\kappa^0_{xy} = a B \ln(1/(bB))$ with the temperature- and sample-dependent parameters $a$ and $b$. We discuss our results in terms of Andreev scattering of quasiparticles by vortices and a recently proposed theory based on the Doppler shift in the quasiparticle spectrum.Comment: 5 pages, 4 figure

Semi-synthetic Derivatives of Limonin A: Synthesis Using Basic Hydrolysis and Reduction with NaBH4

Limonin A (L-A) was obtained from seeds of Citrus sinensis that were dried, grounded, and extracted using Soxhlet equipment. Initially, 100% hexane was used to eliminate fats, and finally, 100% dichloromethane was used in order to concentrate and isolate the compound. L-A recrystallization was performed using acetic acid. The purified fraction was identified as limonin according to spectral nuclear magnetic resonance (NMR) data. Two reactions were performed from L-A: Basic hydrolysis that acted on the A’ lactone ring producing a sodium salt of the lactone, and reduction with NaBH4 to reduce the carbonyl of carbon C-7 and generate the corresponding alcohol limonol. The structural modification of abundant secondary metabolites can become a source of new products with biological activity, useful in the pharmaceutical, cosmetic, and agrochemical industries of natural origin. Keywords: limonin, semisynthetic derivates, bioactive compounds, non-timber forest products. Resumen La limonina A (L-A) se obtuvo a partir de semillas de Citrus sinensis, que fueron secadas, molidas y extraídas en equipo Soxhlet, utilizando inicialmente hexano al 100% para eliminar grasas y finalmente diclorometano al 100% para concentrar y aislar el compuesto. La re cristalización de la L-A se realizó utilizando ácido acético. La fracción purificada se identificó como limonina, acorde a los datos espectrales de RMN (Resonancia Magnética Nuclear). A partir de la Limonina A se realizaron dos reacciones: Hidrólisis básica que actuó sobre el anillo de lactona A’ produciendo la sal sódica de lactona y reducción con NaBH4 para reducir el carbonilo del carbono C-7 y generar el correspondiente alcohol limonol. La modificación estructural de metabolitos secundarios abundantes puede convertirse en una fuente para generar nuevos productos con actividad biológica, útiles en las industrias farmacéutica, cosmética y agroquímica de origen natural. Palabras Clave: Limonina; derivados semisintéticos, compuestos bioactivos, productos forestales no maderables

Thermal Conductivity Tensor in YBa2_2Cu3_3O7−x_{7-x}: Effects of a Planar Magnetic Field

We have measured the thermal conductivity tensor of a twinned YBa$_2$Cu$_3$O$_{7-x}$ single crystal as a function of angle $\theta$ between the magnetic field applied parallel to the CuO$_2$ planes and the heat current direction, at different magnetic fields and at T=13.8 K. Clear fourfold and twofold variations in the field-angle dependence of $\kappa_{xx}$ and $\kappa_{xy}$ were respectively recorded in accordance with the d-wave pairing symmetry of the order parameter. The oscillation amplitude of the transverse thermal conductivity $\kappa^0_{xy}$ was found to be larger than the longitudinal one $\kappa^0_{xx}$ in the range of magnetic field studied here ($0 T$$\le B \le 9$$T$). From our data we obtain quantities that are free from non-electronic contributions and they allow us a comparison of the experimental results with current models for the quasiparticle transport in the mixed state.Comment: 9 Figures, Phys. Rev. B(in press

A survey on Anthozoa and its habitats along the Northwest African coast and some islands: new records, descriptions of new taxa and biogeographical, ecological and taxonomical comments. Part I

Varias especies de Actiniarios y Escleractinias han sido recolectadas y estudiadas a lo largo de la costa noroeste africana y algunos de sus archipiélagos. Esta es la primera parte de un artículo más extenso que está centrado en Marruecos y Cabo Verde pero que también incluye información de otras zonas geográficas (Islas Canarias, Madeira, Gabón y Mauritania). La segunda parte incluirá bastante material del Golfo de Guinea. Cuatro nuevas especies y un nuevo género son descritos además de cinco nuevos registros de especies para la región estudiada. Bellactis caeruleus, Tubastrea caboverdiana, Thalamophyllia wirtzi y Africana wirtzi son las cuatro especies y el nuevo género descrito para la ciencia. Se han completado algunas descripciones de especies que de una forma y otra no estaban bien estudiadas.Several species of Actiniaria and Scleractinia have been searched and collected along the Western African coast and some of its archipelagos. This paper constitutes the first part of an extensive paper and it is focused on Morocco and Cape Verde, although some material and images from other spots (Canary Islands, Madeira, Gabon or even Mauritania) are included. The second part will also include some material from Gulf of Guinea. Four new species and a new genus are described, and five new records are also included in the paper. Bellactis caeruleus, Tubastrea caboverdiana, Thalamophyllia wirtzi and Africana wirtzi are the four new species and the new genus described. Some species, due to previous lack of good descriptions, are presented more deeply from the point of view of the descriptive aspect

Social deprivation and exposure to health promotion. A study of the distribution of health promotion resources to schools in England

This article has been made available through the Brunel Open Access Publishing Fund and is available from the specified link - Copyright @ 2010 Chivu and ReidpathBACKGROUND: Area deprivation is a known determinant of health. It is also known that area deprivation is associated with lower impact health promotion. It is less well known, however, whether deprived areas are less responsive to health promotion, or whether they are less exposed. Using data from a national, school-based campaign to promote vaccination against the human papilloma virus (HPV), the relationship between area deprivation and exposure was examined. METHODS: Taking advantage of a health promotion campaign to provide information to schools about HPV vaccination, a cross sectional study was conducted to examine the relationship between area level, social deprivation, and take-up of (i.e., exposure to) available health promotion material. The sample was 4,750 schools across England, including government maintained and independent schools. The relationship between area deprivation and exposure was examined using bi- and multivariate logistic regression. RESULTS: It was found that schools in the least deprived quintile had 1.32 times the odds of requesting health promotion materials than schools in the most deprived areas (p = .01). This effect was independent of the school size, the type of school, and the geographic region. Conclusion The relationship between area deprivation and the impact of health promotion may be due, at least in part, to differential levels of exposure. The study was limited in scope, pointing to the need for more research, but also points to potentially important policy implications

Relationship between Determinants of Health, Equity, and Dimensions of Health Literacy in Patients with Cardiovascular Disease

Background: Health literacy (HL) has been linked to empowerment, use of health services, and equity. Evaluating HL in people with cardiovascular health problems would facilitate the development of suitable health strategies care and reduce inequity. Aim: To investigate the relationship between different dimensions that make up HL and social determinants in patients with cardiovascular disease. Methods: Observational, descriptive, cross-sectional study in patients with cardiovascular disease, aged 50-85 years, accessing primary care services in Valencia (Spain) in 2018-2019. The Health Literacy Questionnaire was used. Results: 252 patients. Age was significantly related with the ability to participate with healthcare providers (p = 0.043), ability to find information (p = 0.022), and understanding information correctly to know what to do (p = 0.046). Level of education was significant for all HL dimensions. Patients without studies scored lower in all dimensions. The low- versus middle-class social relationship showed significant results in all dimensions. Conclusions: In patients with cardiovascular disease, level of education and social class were social determinants associated with HL scores. Whilst interventions at individual level might address some HL deficits, inequities in access to cardiovascular care and health outcomes would remain unjustly balanced unless structural determinants of HL are taken into account

Reutilización de aguas grises domésticas para el uso eficiente del recurso hídrico: aceptación social y análisis financiero. Un caso en Portugal

La reutilización de aguas grises (AG) contribuye a la preservación del agua y a disminuir la demanda de agua potable. En busca de potenciar esta alternativa en Portugal, se diseñó y evaluó financieramente un sistema hidrosanitario con reutilización de AG en un edificio multifamiliar, considerando la aceptación de los usuarios y los sistemas de tratamiento del AG para cumplir con los estándares de calidad para reuso. Los potenciales usuarios aceptaron el reuso de AG provenientes de la ducha, lavamanos y bidé, en la descarga de inodoros y riego de jardines. El sistema propuesto incluye el tratamiento del AG con reactores biológicos de membrana (MBR). Se presentó un periodo de retorno de 24 años y un valor presente neto de 14.775,18 USD, demostrando la viabilidad del sistema y logrando una reducción anual en el consumo de agua del 33 % (i.e. 3.351,92 m3), contribuyendo al uso eficiente del recurso a nivel urbano.Greywater reuse (GWR) in the domestic sector is increasingly recognized as an alternative to face the growing water scarcity. GWR provides an alternative water source (AWS) for purposes that do not require potable water quality. Aiming at promoting AWS implementation in Portugal, a GWR hydro - sanitary system was designed and financially assessed for a multifamily building (72 flats). Social acceptancy of sanitary devices and treatment systems that fulfil quality standards for water reuse was addressed. Consultation with potential users allowed identifying GWR acceptance for water from shower, washbasin and bidet for end - uses such as toilet flushing and garden irrigation. The system included a commercial treatment consisting on Membrane Bioreactor, and had 24 years payback period, Net Present Value of 14. 775, 18 USD, and annual potable water savings of 33 % (3.351,92 m3). Thus, the designed system was technical, social and financially feasible and can contribute to urban water use efficiency.info:eu-repo/semantics/publishedVersio