Wormholes and Ringholes in a Dark-Energy Universe

The effects that the present accelerating expansion of the universe has on the size and shape of Lorentzian wormholes and ringholes are considered. It is shown that, quite similarly to how it occurs for inflating wormholes, relative to the initial embedding-space coordinate system, whereas the shape of the considered holes is always preserved with time, their size is driven by the expansion to increase by a factor which is proportional to the scale factor of the universe. In the case that dark energy is phantom energy, which is not excluded by present constraints on the dark-energy equation of state, that size increase with time becomes quite more remarkable, and a rather speculative scenario is here presented where the big rip can be circumvented by future advanced civilizations by utilizing sufficiently grown up wormholes and ringholes as time machines that shortcut the big-rip singularity.Comment: 11 pages, RevTex, to appear in Phys. Rev.

CO2 Capture in Chemically and Thermally Modified Activated Carbons Using Breakthrough Measurements: Experimental and Modeling Study

The development of adsorption-based technologies for CO2 capture in the post combustion processes requires finding materials with high capacity of adsorption and low cost of preparation. In this study, the modification of a commercial activated carbon (Norit ROX 0.8), considered as a solid adsorbent for CO2 capture, and the effects of different methods of activations, chemically (hydrogen peroxide, sulfuric acid, nitric acid, and urea) and thermally (at 800 °C) on adsorption performance, have been investigated. Then, CO2 adsorption capacity was studied at different temperatures and pressures to evaluate the effects of various agents on sample performance. The textural properties of the samples were determined using adsorption−desorption isotherms of nitrogen at −196 °C. Finally, the obtained data were modeled by Response Surface Methodology (RSM) and Langmuir isotherm. The results showed that the prepared sample by successive treatments with nitric acid, urea, and thermal calcination has a higher uptake capacity than other modified samples.This work was financially supported by Project POCI-01-0145- FEDER-006984 − Associate Laboratory LSRE-LCM funded by FEDER through COMPETE2020 - Programa Operacional Competitividade e Internacionalização (POCI) − and by national funds through FCT - Fundação para a Ciência e a Tecnologia. M.K. also acknowledges a research grant awarded under project ″VALORCOMP″ (ref.0119_VALORCOMP_ 2_P), financed through INTERREG V A Spain Portugal (POCTEP) 2014-2020, under the European Regional Development Fund by FCT.info:eu-repo/semantics/publishedVersio

Uptake capacity of adsorbent materials derived from municipal solid waste for CO2 capture at post combustion condition

The global climate change, as well as the accumulations of solid waste on landfills, are two of the primary issues nowadays, which it needs the significant attempts to reduce the impact on the ecosystem and environment from both of them [1]. In this work, the production of materials from organic solid waste is considered to produce adsorbent materials, which are assessed in the CO2 capture.This work is a result of the projects “VALORCOMP” (0119_VALORCOMP_2_P), funded by FEDER through Programme INTERREG V A Spain - Portugal (POCTEP) 2014–2020, and “AIProcMat@N2020 - Advanced Industrial Processes and Materials for a Sustainable Northern Region of Portugal 2020”, with the reference NORTE-01-0145-FEDER-000006, supported by NORTE 2020, under the Portugal 2020 Partnership Agreement, through FEDER; and POCI-01-0145-FEDER-006984 – Associate Laboratory LSRE-LCM funded by FEDER through COMPETE2020 - POCI – and by national funds through FCT.info:eu-repo/semantics/publishedVersio

3D tuned porous carbon monolith as catalysts in the wet peroxide oxidation of paracetamol

In recent years, many pharmaceuticals have been identified at trace levels worldwide in the aquatic environment [1]. Municipal wastewater treatment plants (WWTPs) are considered the main sources of these pollutants as they are not generally prepared to deal with such complex substances and thus, they are usually ineffective in their removal [1]. Despite the low concentration of drugs contained in those effluents, the presence of pharmaceuticals, even in trace concentrations, affects the quality of water and constitutes a risk of toxicity for the ecosystems and living organisms [1-2]. Consequently, new regulation for micropollutants discharge and monitoring has been issued in Europe (Directive 2013/39/EU). Paracetamol (PCM) deserves particular attention, since it has recently been discovered as a potential pollutant of waters, largely accumulated in the aquatic environment [3]. This work deals with the treatment of PCM, used as a model pharmaceutical contaminant of emerging concern, by catalytic wet peroxide oxidation using carbon-based monoliths (Fig. 1a) as catalysts. Monoliths were prepared by stereolithographic 3D printing of a photoresin, which was later converted into porous carbon by oxidation in air (300 °C, 6 h) and subsequent pyrolysis in N2 (900 °C, 15 min) as described elsewhere [4]. The materials revealed catalytic activity in the CWPO of PCM allowing to reach PCM conversions up to 30% with a residence time of 3.5 min (Fig. 1b).This work is a result of the Project “AIProcMat@N2020 - Advanced Industrial Processes and Materials for a Sustainable Northern Region of Portugal 2020”, with the reference NORTE-01-0145-FEDER-000006, supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDF); the Associate Laboratory LSRE-LCM - UID/EQU/50020/2019 - funded by national funds through FCT/MCTES (PIDDAC); and CIMO (UID/AGR/00690/2019) through FEDER under Program PT2020. The authors also acknowledge the joint financial support from Fundação para a Ciência e a Tecnologia (FCT) in Portugal and the Deutscher Akademischer Austauschdienst (DAAD) in Germany.info:eu-repo/semantics/publishedVersio

Provervios de Seneca

Copia digital. Madrid : Ministerio de Cultura. Subdirección General de Coordinación Bibliotecaria, 200

Effective Lagrangian description of the lepton flavor violating decays Z-->li lj

A comprehensive analysis of the lepton flavor violating (LFV) decays Z-->li lj is presented within the effective Lagrangian approach. Both the decoupling and nondecoupling scenarios are explored. The experimental constraints from li --> lj lk \bar{lk} and li -->lj gamma as well as some relationships arising from the gauge invariance of the effective Lagrangian are used to put constraints on Z-->li lj. It is found that while current experimental data impose very strong constraints on Z-->mu e, the channel Z --> tau mu (e)still may be at the reach of the planned TESLA collider.Comment: References added, final version to appear in Physical Review

Magneto-Acoustic Wave Oscillations in Solar Spicules

Some observations suggest that solar spicules show small amplitude and high frequency oscillations of magneto-acoustic waves, which arise from photospheric granular forcing. We apply the method of MHD seismology to determine the period of kink waves. For this purposes, the oscillations of a magnetic cylinder embedded in a field-free environment is investigated. Finally, diagnostic diagrams displaying the oscillatory period in terms of some equilibrium parameters are provided to allow a comparison between theoretical results and those coming from observations.Comment: 10 pages, 4 fig

3D-printed activated carbon for post-combustion CO2 capture

The applicability of 3D-printed activated carbons for their use to CO2 capture in post-combustion streams and the influence of activation conditions on CO2 uptake and CO2 to N2 selectivity were studied. For two monoliths with the same open cellular foam geometry but low and high burnoff during activation, a series of fixed-bed breakthrough adsorption experiments under typical post-combustion conditions, in a wide range of temperature (313 and 373 K), and partial pressure of CO2 up to 120 kPa were carried out. It is shown that the higher burnoff during activation of the 3D printed carbon enhances the adsorption capacity of CO2 and N2 due to the increased specific surface area with sorption uptakes that can reach 3.17 mol/kg at 313 K and 120 kPa. Nevertheless, the lower burnoff time on monolith 1 leads to higher selectivity of CO2 over N2, up to 18 against 10 on monolith 2, considering a binary interaction to a mixture of CO2/N2 (15/85 vol%) at 313 K. The single and multicomponent adsorption equilibrium is conveniently described through the dual-site Langmuir isotherm model, while the breakthrough curves simulated using a dynamic fixed-bed adsorption linear driving force model. Working capacities for the 3D printed carbon with lower burnoff time lead to the best results, varying of 0.15–1.1 mol/kg for the regeneration temperature 300–390 K. Finally, consecutive adsorption-desorption experiments show excellent stability and regenerability for both 3D printed activated carbon monoliths and the whole study underpins the high potential of these materials for CO2 capture in post-combustion streams.Generally, the authors are thankful to Dr. M. Rückriem and Dr. A. Schreiber from Microtrac Retsch GmbH for the kind support with nitrogen physisorption and mercury porosimetry measurements. The authors acknowledge the joint financial support from Fundação para a Ciência e a Tecnologia (FCT), in Portugal, and the Deutscher Akademischer Austauschdienst (DAAD), in Germany. Foundation for Science and Technology (FCT, Portugal) and ERDF under Programme PT2020 to CIMO (UIDB/00690/2020) and POCI-01-0145-FEDER006984-Associate Laboratory LSRE-LCM. Foundation for Science and Technology (FCT, Portugal) under Programme PTDC 2020 * 3599-PPCDTI * Engenharia dos Processos Químicos * project PTDC/EQU-EPQ/0467/2020. Foundation for Science and Technology (FCT, Portugal), through the individual research grants SFRH/BD/148525/2019 for Adriano Henrique and DFA/BD/7925/2020 for Lucas F. A. S. Zafanelli.info:eu-repo/semantics/publishedVersio

Efecto de quitosano en el crecimiento in vitro de Thecaphora frezii

Este biopolímero no es tóxico para mamíferos y animales superiores, y estimula la respuesta de defensa de las plantas frente a estrés biótico y abiótico. Desde que Allan y Hadwiger en 1979, mostraron por primera vez el efecto antifúngico de quitosano, este biopolímero ha atraído la atención de numerosos investigadores con el propósito de evaluar la sensibilidad de diferentes hongos frente a este compuesto. Se ha visto que quitosano de bajo peso molecular y alto grado de deacetilación es más efectivo para inhibir el crecimiento de hongos patógenos. El objetivo del presente trabajo fue analizar el efecto de quitosano como inhibidor del crecimiento in vitro del hongo Thecaphora frezii, agente causal de la enfermedad del carbón del maní.Instituto de Patología VegetalFil: Merino, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Unidad de Fitopatología y Modelización Agrícola (UFYMA); Argentina.Fil: Paccioretti, Mauro Andres. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas(CONICET). Unidad de Fitopatología y Modelización Agrícola (UFYMA). Córdoba; Argentina.Fil: Díaz, M.S. Gobierno de Córdoba. Ministerio de Ciencia y Tecnología. Centro de excelencia en productos y procesos Córdoba (CEPROCOR); ArgentinaFil: Figueroa, A.C. Gobierno de Córdoba. Ministerio de Ciencia y Tecnología. Centro de excelencia en productos y procesos Córdoba (CEPROCOR); ArgentinaFil: Paredes, Juan Andrés. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Fitopatología y Modelización Agrícola (UFYMA); Argentina.Fil: Rago, Alejandro Mario. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro de Investigaciones Agropecuarias; Argentin