318 research outputs found
Characterization of wind-blown sediment transport with height in a highly mobile dune (SW Spain)
The Valdevaqueros dune is located at one of the windiest points of Europe, where the frequent occurrence of strong easterly winds has generated a highly mobile dune. Several rotating cup anemometers in vertical array and a self-designed vertical sand trap, were placed to retain the drift sands at different heights over the surface in order to determine theoretical and actual sand transport rates in the Valdevaqueros dune system. General results show that 90% of the wind-blown sand is transported within the first 20cm above the dune crest surface. Theoretical
transport rates based on different empirical formulae were 0.33 to 0.78 times the in-situ sand transport rate detected, which was 2.08·10-2kgm-1s-1 under moderate wind power (mean speed ranging from 8.4 to 17.9ms-1). Analysis of different statistical grain-size parameters helped to understand sand transport distribution at different heights
Strengthening Privacy and Data Security in Biomedical Microelectromechanical Systems by IoT Communication Security and Protection in Smart Healthcare.
Biomedical Microelectromechanical Systems (BioMEMS) serve as a crucial catalyst in enhancing IoT communication security and safeguarding smart healthcare systems. Situated at the nexus of advanced technology and healthcare, BioMEMS are instrumental in pioneering personalized diagnostics, monitoring, and therapeutic applications. Nonetheless, this integration brings forth a complex array of security and privacy challenges intrinsic to IoT communications within smart healthcare ecosystems, demanding comprehensive scrutiny. In this manuscript, we embark on an extensive analysis of the intricate security terrain associated with IoT communications in the realm of BioMEMS, addressing a spectrum of vulnerabilities that spans cyber threats, data manipulation, and interception of communications. The integration of real-world case studies serves to illuminate the direct repercussions of security breaches within smart healthcare systems, highlighting the imperative to safeguard both patient safety and the integrity of medical data. We delve into a suite of security solutions, encompassing rigorous authentication processes, data encryption, designs resistant to attacks, and continuous monitoring mechanisms, all tailored to fortify BioMEMS in the face of ever-evolving threats within smart healthcare environments. Furthermore, the paper underscores the vital role of ethical and regulatory considerations, emphasizing the need to uphold patient autonomy, ensure the confidentiality of data, and maintain equitable access to healthcare in the context of IoT communication security. Looking forward, we explore the impending landscape of BioMEMS security as it intertwines with emerging technologies such as AI-driven diagnostics, quantum computing, and genomic integration, anticipating potential challenges and strategizing for the future. In doing so, this paper highlights the paramount importance of adopting an integrated approach that seamlessly blends technological innovation, ethical foresight, and collaborative ingenuity, thereby steering BioMEMS towards a secure and resilient future within smart healthcare systems, in the ambit of IoT communication security and protection
New design parameters for biparabolic beach profiles (SW Cadiz, Spain)
165 profiles of seventy-one beaches along the Gulf of Cadiz (SW, Spain) were studied to improve the formulation of the beach profile in tidal seas. Maritime climate, degree of energy exposure and size of the sand grains were taken into account to study the two sections of the biparabolic profile. The objective of the study was the determination of more accurate formulations of the design parameters for the equilibrium profile that involves tidal seas. These formulations were modelled and validated based on existing profiles to quantify the error existing between the real profile and the modelling. This comparative analysis was extended by considering the formulations proposed by other authors. The best results were obtained with the proposal presented herein
A Design Parameter for Reef Beach Profiles—A Methodology Applied to Cadiz, Spain
The southwestern coast of Spain is in a tidal zone (mesotidal) which causes the equilibrium profile to be developed in two different sections: the breakage section and the swash section. These two sections give rise to the typical bi-parabolic profile existing in tidal seas. The existence of areas with reefs/rocks which interrupt the normal development of the typical bi-parabolic profile causes different types of beach profiles. The objective of this article is designing an easy methodology for determining new formulations for the design parameters of the equilibrium profile of beaches with reefs in tidal seas. These formulations are applied on 16 profiles to quantify the error between the real profile data and the modelling results. A comparative analysis is extended to the formulations proposed by other authors, from which it is found that better results are obtained with the new formulations
El perfil de playa biparabólico: validación y aplicación al litoral gaditano
El perfil de equilibrio en playas es una herramienta muy utilizada en ingeniería de costas y relativamente de fácil aplicación. Quizás por ello, se ha tendido a “universalizar” su aplicación, especialmente con el perfil de Dean (1977) y Vellinga (1983), perfiles por otro lado muy parecidos, y que responden a lo que denominaríamos “Escuelas Americana y Holandesa”. La “Escuela Española” (González 1995, Bernabeu 1999, Gómez Pina, 1995, 2001) obtuvo expresiones de tipo biparabólico para perfiles en mares con marea
Effects of okadaic acid on the activities of two distinct phosphatidate phosphohydrolases in rat hepatocytes
AbstractIncubation of hepatocytes with okadaic acid displaced the N-ethylmaleimide-sensitive phosphatidate phosphohydrolase from the membrane fraction into the cytosol and partially prevented the oleate-induced movement of phosphohydrolase from cytosol to membranes. However, higher concentrations of oleate still caused translocation and activation of the phosphohydrolase. This enzyme is stimulated by Mg2+, and is probably involved in glycerolipid synthesis. Okadaic acid also decreased the concentration of diacylglycerol within the hepatocytes. Okadaic acid had no observable effect on the activity of an N-ethylmaleimide-insensitive phosphatidate phosphohydrolase which remained firmly attached to membranes. This activity is not stimulated by Mg2+ and is probably involved in signal transduction by the phospholipase D pathway
Optical and structural characterization of TiO-Zn-V thin films synthesized using the sol-gel method
We report structural and optical properties of thin films grown by the sol–gel method and spin-coating technique. We synthesized thin films of Tiox-Zn-V with varying concentrations of vanadium and titanium. The resulting thin films are characterized by x-ray diffraction (XRD), wavelength-dispersive x-ray fluorescence, and ultraviolet–visible spectrophotometry. XRD results indicate that the majority phase of the resulting structure was Tiox-Zn with a crystallographic plane (020) and an angular position 2θ of 42.38°. The presence of vanadium was confirmed by x-ray fluorescence, and transmittance measurements in the 300–800-nm range showed that the transmittance of this material was over 80%, but reduced in the presence of vanadium. We also found the width of the energy gap to decrease as the concentration of vanadium is increased, thereby suggesting an increase in conductivity and the introduction of a certain amount of disorder into the Tiox-Zn structure according to the Wemple–DiDomenico (WDD) formulation of energy dispersion. Thus, the influence of vanadium on the optical properties of the Tiox-Zn system could be advantageous for the fabrication of smart windows
Estudio del impacto visual y propuesta de mejora mediante la implantación de arbolado urbano del parque eólico "La Plata"
En los últimos años, las energías renovables han pasado a jugar un papel fundamental en el abastecimiento energético mundial, debido al aumento de la demanda de energía y a la creciente problemática ambiental. Sin embargo, las energías renovables no están exentas de problemas medioambientales, y factores como la ocupación del territorio y el impacto visual hacen que su aceptación social disminuya. En el caso de la energía eólica, la disposición de los aerogeneradores queda condicionada por la intermitencia en la dirección e intensidad del viento, lo que complica la reducción del impacto visual de los parques eólicos y, por tanto, su aceptación social. Debido a la complejidad de los escenarios en los que se sitúan estas instalaciones, existe una gran diversidad de metodologías para optimizar su integración en el paisaje, pero no hay una metodología generalizada que considere que la población debe jugar un papel importante en su desarrollo. Para conocer y valorar el impacto visual que genera el parque eólico "La Plata", se han aplicado tres metodologías: una basada en la valoración cualitativa de los escenarios de población, otra en el uso de Sistemas de Información Geográfica (SIG) y la última a través de cuestionarios, comprobando así la equidad en los resultados de las tres metodologías. Aplicadas las tres metodologías y comparando los resultados, todas ellas coinciden en la valoración del impacto visual negativo en el paisaje del parque eólico ?La Plata?, si bien la metodología que se apoya en el uso de cuestionarios incide directamente en la percepción de la población de este impacto, y discierne sus principales problemas. Para determinar la situación del arbolado propuesto se ha utilizado un SIG seleccionando las áreas prioritarias y así evaluar la reducción del impacto visual producido
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