Radiation in (2+1)-dimensions

In this paper we discuss the radiation equation of state $p=\rho/2$ in (2+1)-dimensions. In (3+1)-dimensions the equation of state $p=\rho/3$ may be used to describe either actual electromagnetic radiation (photons) as well as a gas of massless particles in a thermodynamic equilibrium (for example neutrinos). In this work it is shown that in the framework of (2+1)-dimensional Maxwell electrodynamics the radiation law $p=\rho/2$ takes place only for plane waves, i.e. for $E = B$. Instead of the linear Maxwell electrodynamics, to derive the (2+1)-radiation law for more general cases with $E \neq B$, one has to use a conformally invariant electrodynamics, which is a 2+1-nonlinear electrodynamics with a trace free energy-momentum tensor, and to perform a volumetric spatial average of the corresponding Maxwell stress-energy tensor with its electric and magnetic components at a given instant of time $t$.Comment: 7 pages. Accepted for publication in Phys. Lett.

Overview of ASDEX Upgrade results

The ASDEX Upgrade (AUG) programme is directed towards physics input to critical elements of the ITER design and the preparation of ITER operation, as well as addressing physics issues for a future DEMO design. Since 2015, AUG is equipped with a new pair of 3-strap ICRF antennas, which were designed for a reduction of tungsten release during ICRF operation. As predicted, a factor two reduction on the ICRF-induced W plasma content could be achieved by the reduction of the sheath voltage at the antenna limiters via the compensation of the image currents of the central and side straps in the antenna frame. There are two main operational scenario lines in AUG. Experiments with low collisionality, which comprise current drive, ELM mitigation/suppression and fast ion physics, are mainly done with freshly boronized walls to reduce the tungsten influx at these high edge temperature conditions. Full ELM suppression and non-inductive operation up to a plasma current of Ip = 0.8 MA could be obtained at low plasma density. Plasma exhaust is studied under conditions of high neutral divertor pressure and separatrix electron density, where a fresh boronization is not required. Substantial progress could be achieved for the understanding of the confinement degradation by strong D puffing and the improvement with nitrogen or carbon seeding. Inward/outward shifts of the electron density profile relative to the temperature profile effect the edge stability via the pressure profile changes and lead to improved/decreased pedestal performance. Seeding and D gas puffing are found to effect the core fueling via changes in a region of high density on the high field side (HFSHD). The integration of all above mentioned operational scenarios will be feasible and naturally obtained in a large device where the edge is more opaque for neutrals and higher plasma temperatures provide a lower collisionality. The combination of exhaust control with pellet fueling has been successfully demonstrated. High divertor enrichment values of nitrogen EN 10 have been obtained during pellet injection, which is a prerequisite for the simultaneous achievement of good core plasma purity and high divertor radiation levels. Impurity accumulation observed in the all-metal AUG device caused by the strong neoclassical inward transport of tungsten in the pedestal is expected to be relieved by the higher neoclassical temperature screening in larger devices.European Commission (EUROfusion 633053

BTZ black hole from (3+1) gravity

We propose an approach for constructing spatial slices of (3+1) spacetimes with cosmological constant but without a matter content, which yields (2+1) vacuum with $\Lambda$ solutions. The reduction mechanism from (3+1) to (2+1) gravity is supported on a criterion in which the Weyl tensor components are required to vanish together with a dimensional reduction via an appropriate foliation. By using an adequate reduction mechanism from the Pleba\'nski-Carter[A] solution in (3+1) gravity, the (2+1) BTZ solution can be obtained.Comment: 4 pages, Late

Overview of progress in European medium sized tokamaks towards an integrated plasma-edge/wall solution

Integrating the plasma core performance with an edge and scrape-off layer (SOL) that leads to tolerable heat and particle loads on the wall is a major challenge. The new European medium size tokamak task force (EU-MST) coordinates research on ASDEX Upgrade (AUG), MAST and TCV. This multi-machine approach within EU-MST, covering a wide parameter range, is instrumental to progress in the field, as ITER and DEMO core/pedestal and SOL parameters are not achievable simultaneously in present day devices. A two prong approach is adopted. On the one hand, scenarios with tolerable transient heat and particle loads, including active edge localised mode (ELM) control are developed. On the other hand, divertor solutions including advanced magnetic configurations are studied. Considerable progress has been made on both approaches, in particular in the fields of: ELM control with resonant magnetic perturbations (RMP), small ELM regimes, detachment onset and control, as well as filamentary scrape-off-layer transport. For example full ELM suppression has now been achieved on AUG at low collisionality with n = 2 RMP maintaining good confinement HH(98,y2) 0.95. Advances have been made with respect to detachment onset and control. Studies in advanced divertor configurations (Snowflake, Super-X and X-point target divertor) shed new light on SOL physics. Cross field filamentary transport has been characterised in a wide parameter regime on AUG, MAST and TCV progressing the theoretical and experimental understanding crucial for predicting first wall loads in ITER and DEMO. Conditions in the SOL also play a crucial role for ELM stability and access to small ELM regimes.European Commission (EUROfusion 633053

Los costos no laborales y el mercado laboral: impacto de la reforma de salud en Colombia.

El documento analiza el impacto que la reforma a la seguridad social en Colombia (Ley 100 de 1993) ha tenido sobre el mercado laboral. Utilizando series de tiempo (a través de métodos de cointegración y de regresiones iterativas, entre otros) se encuentra que el incremento de 14 puntos porcentuales en los costos no salariales, en un escenario donde la protección social se financia a través de impuestos a la nómina, ha generado una profunda segmentación del mercado laboral. Esta situación debe entenderse como la coexistencia de dos mercados laborales, uno asalariado y otro cuenta propia, que actúan como sustitutos el uno del otro. Por tanto, la reforma ha promovido la creación de empleos cuenta propia e informalidad, pues los trabajadores buscan emplearse en sectores donde pueden evadir estos pagos, mientras que las firmas se han visto desincentivadas a crear empleos formales. Este proceso ha sido particularmente nocivo para la población menos educada y más vulnerable, limitando así la generación de ingresos sostenibles y la superación de la pobrezaCostos no salariales, segmentación del mercado laboral, informalidad

Rethinking the construction of welfare in Mexico: Going beyond the economic measures

This study utilized a multidimensional measure of social welfare composed of 26 social indicators integrated in nine categories: education, employment and social protection, income, health, housing conditions, subjective wellbeing, social capital, use of technology, and culture and leisure to help understand social welfare in Mexico. We also compared the integrated measure with the Human Development Index. Estimation was performed using the DP2 method. Our analysis indicated that the health and housing conditions categories contributed the most to social welfare across the 32 Mexican States. In relation to the indicators, income and trust in other people were associated with welfare. Further, results on the welfare ranking of Mexican states revealed variations between the two indices ðDP2 and the HDI). Specifically, only four states occupied the same position on both indices, ten recorded different positions on DP2 moving up or down from their levels of social welfare. Implications of observed correlations are presented

Recuperación de cera de cutícula de caña de azúcar mediante separación mecánica y extracción con solventes

The industrial experience in the extraction and refining of sugar cane crude wax in Cuba from filter mud confirms the feasibility of such technologies for the production of waxes addressed to the pharmaceutical market, to high price drugs such as policosanol. With the aim of develop a new technology for the recovery the natural wax that covers the cane stalk, the present paper shows a new achievement, the recovery of the wax that occurs in the fraction DERMAX, a cuticular layer that remains after the mechanical processing of the sugar cane in a blade separator INTERCANE®, 5 ton/h, which was tested at the sugar mill. La Reforma, Veracruz state in Mexico. Two extraction systems, soxhlet and soxtec were tested and three different kind of organic solvents were evaluated. The waxy material was analysed by gas chromatography. A brief data about the chemical composition of the new quality of wax is disclosed.Las experiencias productivas de una planta industrial para la extracción y refinación de cera cruda a partir de la torta de los filtros (cachaza) confirman que estas tecnologías son viables para la producción de cera en lotes de pequeño volumen destinada al sector farmacéutico para aislar principios activos como es el caso del policosanol de uso médico. Con el objetivo de desarrollar esquemas enfocados a recuperar la cera natural que cubre el tallo de la caña de azúcar, en el presente trabajo se presenta como resultado novedoso la recuperación de la cera contenida en la fracción DERMAX, residuo cuticular que se obtiene del procesamiento mecánico de la caña en una máquina separadora de cuchillas INTERCANE®, de 5 ton/h, que fue probada en el ingenio La Reforma en el estado de Veracruz, México. Por medio de las técnicas de extracción Soxhlet y Soxtec se procesó la fracción DERMAX y se estudiaron 3 clases de disolventes orgánicos como agentes extractivos. El material ceroso extraído fue caracterizado por técnicas de determinación de índices físico-químicos y por cromatografía gaseosa, por lo que se reportan algunos datos sobre la composición química de esta nueva calidad de cera vegetal

Evaluation of clinical and antidiabetic treatment characteristics of different sub-groups of patients with type 2 diabetes : Data from a Mediterranean population database

Altres ajuts: Institut Universitari d'Investigació en Atenció Primària Jordi GolAltres ajuts: MSD Spain 4R16/062-1Aims: To describe the characteristics and antidiabetic treatment among type 2 diabetes patients according to the clinical conditions prioritized in the Spanish 2020 RedGDPS (Primary Care Diabetes Study Groups Network) therapeutic algorithm: obesity, older than 75 years, chronic kidney disease, cardiovascular disease, and heart failure. Methods: Retrospective, cross-sectional study. Clinical characteristics, the use of antidiabetic drugs and the KDIGO renal risk categories at 31.12.2016 were retrieved from the SIDIAP (Information System for Research in Primary Care) database (Catalonia, Spain). Results: From a total of 373,185 type 2 diabetes patients, 37% were older than 75 years, 45% obese, 33% had chronic kidney disease, 23.2% cardiovascular disease and 6.9% heart failure. Insulin was more frequently prescribed in chronic kidney disease, cardiovascular disease and heart failure whereas Sodium-Glucose cotransporter 2 inhibitors and Glucagon Like Peptide 1 receptor agonists were scarcely prescribed (2.6% and 1.4%, respectively). Among patients with severe renal failure, contraindicated drugs like metformin (16%) and sulfonylureas (6.1%) were still in use. The 2012 KDIGO renal risk categories distribution was: Low: 60.9%, Moderate: 21.6%, High: 9.8% and Very high: 7.7%. Conclusions: Almost 80% of our T2DM patients meet one of the five clinical conditions that should be considered for treatment individualization. Importantly, a relevant number of patients with severe renal failure were found to use contraindicated drugs

Regular (2+1)-dimensional black holes within non-linear Electrodynamics

(2+1)-regular static black hole solutions with a nonlinear electric field are derived. The source to the Einstein equations is an energy momentum tensor of nonlinear electrodynamics, which satisfies the weak energy conditions and in the weak field limit becomes the (2+1)-Maxwell field tensor. The derived class of solutions is regular; the metric, curvature invariants and electric field are regular everywhere. The metric becomes, for a vanishing parameter, the (2+1)-static charged BTZ solution. A general procedure to derive solutions for the static BTZ (2+1)-spacetime, for any nonlinear Lagrangian depending on the electric field is formulated; for relevant electric fields one requires the fulfillment of the weak energy conditions.Comment: 5 pages, Latex, 2 figure