Observación del catálogo F.K.Z.

Se comunica la terminación de las observaciones realizadas con el Círculo Meridiano del Observatorio Astronómico "Félix Aguilar" para el programa F.K.S.I.Asociación Argentina de Astronomí

Quinto catálogo fundamental del círculo meridiano de San Juan

Este Catálogo fue observado con el Círculo Meridiano Reversible Repsold de 190 mm de abertura y 2.25 m de distancia focal, que se opera en el Observatorio Astronómico "Félix Aguilar" de la Universidad Nacional de San Juan, y contiene las estrellas FK4 que fueren observadas como estrellas de referencia para la confección del Segundo Catálogo Círculo Meridiano San Juan, FKSZ, catálogo al que deberá remitirse para mejor información.Asociación Argentina de Astronomí

On the optimal indoor air conditions for sars-cov-2 inactivation. An enthalpy-based approach

In the CoViD-19 pandemic, the precautionary approach suggests that all possible measures should be established and implemented to avoid contagion, including through aerosols. For indoor spaces, the virulence of SARS-CoV-2 could be mitigated not only via air changes, but also by heating, ventilation, and air conditioning (HVAC) systems maintaining thermodynamic conditions possibly adverse to the virus. However, data available in literature on virus survival were never treated aiming to this. In fact, based on comparisons in terms of specific enthalpy, a domain of indoor comfort conditions between 50 and 60 kJ/kg is found to comply with this objective, and an easy-to-use relationship for setting viable pairs of humidity and temperature using a proper HVAC plant is proposed. If confirmed via further investigations on this research path, these findings could open interesting scenarios on the use of indoor spaces during the pandemic

Segundo catálogo círculo meridiano San Juan

Este catálogo fue observado con el Círculo Meridiano Reversible que se opera en el Observatorio Astronómico "Félix Aguilar", de la Universidad Nacional de San Juan. Contiene 617 estrellas del Catálogo Original recibido del Departamento de Astronomía de la Universidad de Chile denominado FKSZ (Fundamental Katalog Slabi Zbiozp). Las estrellas están distribuidas en la zona +30° a -90° en declinación. Las observaciones, se iniciaron en agosto de 1975 y se terminaron en noviembre de 1977 con un total de 2949 pasajes en ascensión recta y de 2864 pasajes en declinación. El promedio del error cuadrático medio en ascensión recta de una observación es de 0ˢ.021 y de 0".39 en declinación.Asociación Argentina de Astronomí

Predicting sars-cov-2 weather-induced seasonal virulence from atmospheric air enthalpy

Following the coronavirus disease 2019 (COVID-19) pandemic, several studies have examined the possibility of correlating the virulence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19, to the climatic conditions of the involved sites; however, inconclusive results have been generally obtained. Although neither air temperature nor humidity can be independently correlated with virus viability, a strong relationship between SARS-CoV-2 virulence and the specific enthalpy of moist air appears to exist, as confirmed by extensive data analysis. Given this framework, the present study involves a detailed investigation based on the first 20-30 days of the epidemic before public health interventions in 30 selected Italian provinces with rather different climates, here assumed as being representative of what happened in the country from North to South, of the relationship between COVID-19 distributions and the climatic conditions recorded at each site before the pandemic outbreak. Accordingly, a correlating equation between the incidence rate at the early stage of the epidemic and the foregoing average specific enthalpy of atmospheric air was developed, and an enthalpy-based seasonal virulence risk scale was proposed to predict the potential danger of COVID-19 outbreak due to the persistence of weather conditions favorable to SARS-CoV-2 viability. As an early detection tool, an unambiguous risk chart expressed in terms of coupled temperatures and relative humidity (RH) values was provided, showing that safer conditions occur in the case of higher RHs at the highest temperatures, and of lower RHs at the lowest temperatures. Despite the complex determinism and dynamics of the pandemic and the related caveats, the restriction of the study to its early stage allowed the proposed risk scale to result in agreement with the available infectivity data highlighted in the literature for a number of cities around the world

Procedimiento para la reducción en declinación de series FK4- Resultados obtenidos

Se presentan resultados preliminares obtenidos de 7183 observaciones de declinación Series Kusner. Se discuten algunos detalles de la reducción y se compara el sistema de declinación observado en el FK4 en Δδ.Asociación Argentina de Astronomí

Resultados de observaciones meridianas del Cometa P/Halley

Reportamos los resultados de las observaciones astrométricas del cometa P/Halley, realizadas durante el período comprendido entre el 12.11.1985 y el 03.05.1986, con el círculo meridiano Repsold instalado en San Juan. Publicamos las coordenadas aparentes topo y geocéntricas de los quince pasajes meridianos observados: cuatro pre-perihelio y once post-perihelio.Asociación Argentina de Astronomí

Use of particle counter system for the optimization of sampling ,identification and decontamination procedures for biological aerosols dispersion in confined environment

Abstract In a CBRNe (Chemical, Biological, Radiological, Nuclear and explosive) scenario, biological agents hardly allow efficient detection/identification because of the incubation time that provides a lag in symptoms outbreak following their dissemination. The detection of atmospheric dispersion of biological agents (i.e.: toxins, viruses, bacteria and so on) is a key issue for the safety of people and security of environment. Another fundamental aspect is related to the efficiency of the sampling method, which leads to the identification of the agent released, in fact an effective sampling method is needed either to identify the contamination and to check for the decontamination procedure. Environmental monitoring is one of the ways to improve fast detection of biological agents; for instance, particle counters with the ability of discriminating between biological and non-biological particles are used for a first warning when the amount of biological particles exceeds a particular threshold. Nevertheless, these systems are not able to distinguish between pathogen and non-pathogen organisms, thus, classical “laboratory” assays are still required to unambiguously identify the particle which triggered the warning signal. In this work, a combination of commercially available equipment for detection and identification of the atmospheric dispersion of biological agents was evaluated in partnership between the Italian Army, the Department of Industrial Engineering and the School of Medicine and Surgery of the University of Rome “Tor Vergata”. The aim of this work, whose results are presented here, was to conduce preliminary studies on the dynamics of biological aerosols fallout after its dispersion, to improve detection, sampling and identification techniques. This will help minimizing the impact of the release of biological agents, guarantee environmental, and people safety and securit

Observación de radio-estrellas con el círculo meridiano de San Juan

Se informa sobre el avance del programa de observación de radio-estrellas con el Círculo Meridiano instalado en el Observatorio Astronómico "Félix Aguilar".Asociación Argentina de Astronomí

Resultados de observaciones meridianas de radio-estrellas

Uno de los principales problemas de la astrometría fundamental es la construcción de un marco inercial de referencia. Actualmente se están realizando importantes esfuerzos para materializarlo en base a las posiciones de radio-fuentes de origen extragaláctico, medidas con interferómetros de linea-base muy larga. La idea de su utilización se fundamenta en que estos objetos, debido a la gran distancia a la que se encuentran; no presentan movimientos propios medibles y por lo tanto son considerados como los mejores candidatos para establecer un sistema de coordenadas no-rotacional.Asociación Argentina de Astronomí