The role of magnetoplasmons in Casimir force calculations

In this paper we review the role of magneto plasmon polaritons in the Casimir force calculations. By applying an external constant magnetic field a strong optical anisotropy is induced on two parallel slabs reducing the reflectivity and thus the Casimir force. As the external magnetic field increases, the Casimir force decreases. Thus, with an an external magnetic field the Casimir force can be controlled.The calculations are done in the Voigt configuration where the magnetic field is parallel to the slabs. In this configuration the reflection coefficients for TE and TM modes do not show mode conversion.Comment: contribution to QFEXT09, Norman, Oklahoma 200

Pull-in control due to Casimir forces using external magnetic fields

We present a theoretical calculation of the pull-in control in capacitive micro switches actuated by Casimir forces, using external magnetic fields. The external magnetic fields induces an optical anisotropy due to the excitation of magneto plasmons, that reduces the Casimir force. The calculations are performed in the Voigt configuration, and the results show that as the magnetic field increases the system becomes more stable. The detachment length for a cantilever is also calculated for a cantilever, showing that it increases with increasing magnetic field. At the pull-in separation, the stiffness of the system decreases with increasing magnetic field.Comment: accepted for publication in App. Phys. Let

Analysis of Indoor Radon Distribution Within a Room By Means of Computational Fluid Dynamics (CFD) Simulation

Radon gas is recognized by international organizations such as the United States Environmental Protection Agency (US-EPA) as the main contributor of radiation environmental to which human beings are exposed. Therefore, the evaluation of indoor radon concentration is a matter of public interest. The emanation and the income of the gas inside a room will generate a negative impact on the quality of the air when the place is not properly ventilated. Understanding how this gas will be distributed inside the room will allow to predict the spatial and temporal variations of radon levels and identify these parameters will provide important information that researchers can be used for calculate radiation dose exposure. Consequently, this studies can prevent a health risk for the people that live or work within the room. Currently, several researchers use the technique called Computational Fluid Dynamics (CFD) to simulate the distribution of gas radon, making use of the various commercial programs that exist in the market. In this work, three simulations were developed in rooms that have a similar geometry but different dimensions, in order to observe how the gas is distributed inside a closed space and to analyze how this distribution varies when the volume of the place is increased. The results show that as the volume of the site increases the radon is mitigated more rapidly and therefore has lower levels of concentration of this gas, as long as the level of radon emanation is kept constant

Van der Waals torque induced by external magnetic fields

We present a method for inducing and controlling van der Waals torques between two parallel slabs using a constant magnetic field. The torque is calculated using the Barash theory of dispersive torques. In III-IV semiconductors such as $InSb$, the effect of an external magnetic field is to induce an optical anisotropy, in an otherwise isotropic material, that will in turn induce a torque. The calculations of the torque are done in the Voigt configuration, with the magnetic field parallel to the surface of the slabs. As a case study we consider a slab made of calcite and a second slab made of $InSb$. In the absence of magnetic field there is no torque. As the magnetic field increases, the optical anisotropy of $InSb$ increases and the torque becomes different from zero, increasing with the magnetic field. The resulting torque is of the same order of magnitude as that calculated using permanent anisotropic materials when the magnetic fields is close to 1 T.Comment: to appear in Journal of Applied Physic

FINDRISC, utilidad en el screening de diabetes, personalización y asociaciones: FINDRISC, utility in the screening of diabetes, personalization and associations

ABSTRACT Introduction: We are currently experiencing the diabetes pandemic, in 2017 the "International Diabetes Federation" reported that 425 million adults have diabetes. Within the prevention and screening we have FINDRISC (Finnish Diabetes Risk Score), a test that is being widely used, so we must review the available evidence, if it has sufficient predictive capacity to be recommended and used, if there is personalization according to sociodemographic patterns, and if it has relationships. Methods: In this systematic review article, the information was compiled from PubMed, Elsevier library, ScienceDirect, BMJ Journals and “Revista de la facultad de Medicina Humana de la URP. Results: Of 30 articles found, 23 were selected: 12 were analytical, 7 descriptive, 2 cases and control, 2 clinical trials. Conclusion: The average AUC is 77.81%, so it has sufficient positive predictive capacity. 91% suggest its use, 35% of studies have personalized it and can be linked to metabolic syndrome, subclinical vascular complications and quality of life. Key words: FINDRISC; Metabolic syndrome; Prediabetic state; Obesity; Health Survey; Diabetes Mellitus, Type 2, Detection, Risk; Public health. (source: MeSH NLM) DOI:  10.25176/RFMH.v18.n3.1594RESUMEN Introducción: Estamos viviendo actualmente la pandemia de la diabetes, en el año 2017 la “International Diabetes Federation” informo que 425 millones de adultos tienen diabetes. Dentro de la prevención y screening tenemos al FINDRISC (Finnish Diabetes Risk Score), un test que está siendo ampliamente utilizado, por ello debemos revisar la evidencia disponible, si tiene la suficiente capacidad predictiva para ser recomendado y utilizado, si existe personalización según patrones sociodemográficos, y si tiene relaciones con otras patologías. Métodos: En este artículo de revisión sistemática, la información fue recopilada de PubMed, Elsevier library, ScienceDirect, BMJ Journals y de la revista de la facultad de Medicina Humana de la URP. Resultados: De 30 artículos encontrados, 23 fueron seleccionados: 12 fueron analíticos, 7 descriptivos, 2 casos y control, 2 clinical trials. Conclusión: El AUC promedio es de 77.81%, por lo que tiene suficiente capacidad predictiva positiva. El 91% sugiere su uso, el 35% de los estudios lo ha personalizado y se puede vincular con síndrome metabólico, complicaciones vasculares subclínicas y calidad de vida. Palabras clave: FINDRISC; Síndrome metabólico; Estado prediabético; Obesidad; Encuesta de Salud; Diabetes Mellitus, Tipo 2, Detección, Riesgo; Salud pública. (fuente: DeCS BIREME) DOI:  10.25176/RFMH.v18.n3.159

Optimization of the Position of the CR-39 Polycarbonate Sheet Inside the Solid State Track Detector “Measuring Device” Through Computational Fluid Dynamics Technique

The “measuring device” is one of the most reliable, efficient and economic indoor radon dosimeters that exist. This device was developed by the Proyecto de Aplicaciones de la Dosimetría (PAD) at the Physics Institute of UNAM (IF-UNAM) and consists of a transparent rigid plastic cup, a CR-39 polycarbonate sheet and a standard size metal clip that is used to hold the polycarbonate in the center of the cup. The cup is wrapped and covered with a low-density polyurethane protector in order to prevent the detector from being irradiated by ionizing particles found in the environment. In this work, an analysis was carried out that allowed to understand how the radon concentration on the polycarbonate sheet varies when its height is changed with respect to the base of the plastic cup, in order to understand what position increase the probability of interaction between radon and the surface of the detector. For the development of this work, four computational simulations were performed with the technique called Computational Fluid Dynamics (CFD). The results shows that as the CR-39 is positioned more closed to the base of the cup, the probability of interaction of the radon and the detector increase. Based on these results it is concluded that, when there is a limit in the time in which a measuring device can be placed in the zone where it is desired to quantify indoor radon, it is recommended to collocated the CR-39 at 1 cm with respect to the base of the cup

The nature of twitter trending topics: Analysing intrinsic factors associated with the twitter ecosystem

© 2018 The authors and IOS Press. All rights reserved. We are inundated with data—companies such as Twitter deal with petabytes of information on a daily basis. However, some users, especially the new ones, often find it difficult to cope with the overwhelming and disorganised deluge of information. Scientists have already worked out ways to identify Twitter trending topics, as a means to index information and make sense of it. However, we know little about the impact on trending topics of various intrinsic factors associated with the Twitter ecosystem. For example, anecdotal evidence suggests that trending topics are characterised by highly polarised tweets, or that large audiences typically host the emergence of trending topics. However, no study has yet addressed these issues formally. To remedy this situation, we have launched an investigation on the nature of trending topics. Our initial observations indicate that there is a correlation between strong sentiment polarity and the emergence of trending topics—we can also confirm that the strength of the polarity drops as the trending topics fade away. Conversely, our experiments highlight that there is no correlation between the size of a Twitter audience and the rise of trending topics

Adaptation and evaluation of the bottle assay for monitoring insecticide resistance in disease vector mosquitoes in the Peruvian Amazon

<p>Abstract</p> <p>Background</p> <p>The purpose of this study was to establish whether the "bottle assay", a tool for monitoring insecticide resistance in mosquitoes, can complement and augment the capabilities of the established WHO assay, particularly in resource-poor, logistically challenging environments.</p> <p>Methods</p> <p>Laboratory reared <it>Aedes aegypti </it>and field collected <it>Anopheles darlingi </it>and <it>Anopheles albimanus </it>were used to assess the suitability of locally sourced solvents and formulated insecticides for use with the bottle assay. Using these adapted protocols, the ability of the bottle assay and the WHO assay to discriminate between deltamethrin-resistant <it>Anopheles albimanus </it>populations was compared. The diagnostic dose of deltamethrin that would identify resistance in currently susceptible populations of <it>An. darlingi </it>and <it>Ae. aegypti </it>was defined. The robustness of the bottle assay during a surveillance exercise in the Amazon was assessed.</p> <p>Results</p> <p>The bottle assay (using technical or formulated material) and the WHO assay were equally able to differentiate deltamethrin-resistant and susceptible <it>An. albimanus </it>populations. A diagnostic dose of 10 μg a.i./bottle was identified as the most sensitive discriminating dose for characterizing resistance in <it>An. darlingi </it>and <it>Ae. aegypti</it>. Treated bottles, prepared using locally sourced solvents and insecticide formulations, can be stored for > 14 days and used three times. Bottles can be stored and transported under local conditions and field-assays can be completed in a single evening.</p> <p>Conclusion</p> <p>The flexible and portable nature of the bottle assay and the ready availability of its components make it a potentially robust and useful tool for monitoring insecticide resistance and efficacy in remote areas that require minimal cost tools.</p