A study of Ultra-High-Energy Cosmic Ray propagation in one-dimensional simulations

Cosmic Rays have come to play an important role in understanding the universe, and astroparticle physics has undergone major developments in the last few decades. As such, several observatories have been set up with the purpose of detecting these particles, and simulation frameworks have been developed in order to further analyze their behavior by creating highly variable environments and parameters. This work covers the essential theory required to study propagation of Ultra- High-Energy Cosmic Rays restricted to linear one-dimensional propagation only; this includes the primary methods of energy loss during propagation, mainly through reactions with the photon background like photo-pion production and photo-disintegration, and additional cosmological effects. The study was done using the CRPropa 3.0 simulation framework. To determine the best possible maximum energy for the simulations, initial trials were done by testing the GZK cutoff for multiple energy values, followed by an analysis of heavier nuclei propagation. As a final complete test run, a model of the cosmic ray spectrum for energies above 1018 eV was made based on two data sets, one made from the average composition of the whole CR energy spectrum, and the other from The Pierre-Auger Observatory measurements for the high energy range. The results showed that initial source composition was the determining factor in the shape of the CR spectrum. These initial simulations done in this work will set the ground for future more complex simulations and studies.Los rayos cósmicos juegan un papel importante en nuestro entendimiento del universo, por eso, la física de astropartículas ha sido desarrollada en gran medida en estas últimas décadas. Varios observatorios han sido construidos con el propósito de detectar estas partículas, y a su vez se han desarrollado programas de simulaciones para analizar su comportamiento usando ambientes y variables con una alta variabilidad. Este trabajo cubre la teoría necesaria para estudiar la propagación de rayos cósmicos de ultra-altas energías restringido a una sola dimensión; esto incluye las principales causas de pérdida de energía durante su propagación, principalmente a través de interacciones con el fondo de fotones como la fotoproducción de piones y fotodesintegración, así como otros efectos cosmológicos. Este estudio fue realizado con el programa de simulaciones CRPropa 3.0. Para determinar la mejor energía máxima para las simulaciones, los primeros ensayos comprobaron el límite GZK para múltiples valores de energía, seguido de un análisis de la propagación de núcleos más pesados. A manera de ensayo final, un modelo del espectro de rayos cósmicos para energías mayores a 1018 eV fue hecho basado en dos grupos de datos, uno a partir de la composición general promedio de todo el espectro de energías de los rayos cósmicos, y el otro a partir de mediciones hechas por el observatorio Pierre-Auger para altas energías. Los resultados muestran que la composición inicial de la fuente es el factor determinante en la forma del espectro. Las simulaciones iniciales hechas en este trabajo serán utilizadas como base para futuras y más complejas investigaciones.Trabajo de investigació

Microsatellite analysis of Alpine grape cultivars ( Vitis vinifera L.): alleged descendants of Pliny the Elder's Raetica are genetically related

According to Pliny the Elder and other Greco-Roman geoponics, Raetica was a famous white grape as well as a white wine produced in Raetia, a Province of the Roman Empire. Does Raetica grape have modern descendants? Etymologically and geographically, the white ‘Rèze' from Valais (Switzerland) would be the best candidate. Using available microsatellite data, we searched for relatives of ‘Rèze' in our database containing over 1,700 genotypes of grape cultivars from all over the world. Twelve cultivars showing putative first-degree (parent-offspring or full-siblings) or second-degree (grandparent-grandoffspring, uncle-nephew or half-siblings) relationships with ‘Rèze' were then analysed at 60 microsatellite markers. Calculation of allele sharing and likelihood ratios between competing relationship categories revealed that four cultivars had parent-offspring relationship with ‘Rèze': ‘Cascarolo Bianco' (Piedmont, Italy), ‘Arvine Grande' (Valais, Switzerland), ‘Groppello di Revò' and ‘Nosiola' (Trentino, Italy). Given that some of these are also said to be Raetica descendants, we may well be on the tracks of Pliny the Elder's Raetica grape. However, there is no evidence about the identity of Raetica. Analysis of ancient DNA of grape pips excavated from archaeological sites of the Roman times might provide key information. Our first attempts were unsuccessful, but analysis of additional samples and optimisation of the method could provide groundbreaking results about the identity of the grapes cultivated in classical antiquit

A linear regression based-approach to collective gas source localization

This work addresses the problem of gas leaks and proposes a search strategy for identifying the source of a gas leak within a virtual simulation environment. The research focuses on designing and implementing simulation, control, and gas source search packages using swarm robotics. The simulation employs numerical integration strategies, while the robot swarm control is based on potential fields theory. The location of the gas source using a weighted linear regression strategy is used to estimate the gas concentration gradient, which plays a crucial role in the optimization strategy employed. The paper presents an overview of the key concepts employed and their relevance to different stages of the problem and highlights the main results achieved through the chosen strategies. A significant outcome of this work is the development of reusable software packages applicable to various research contexts in mobile robotics.The project is supported by National Council for Scientific and Technological Development – CNPq (process CNPq 407984/2022-4); Fund for Scientific and Technological Development – FNDCT; Ministry of Science, Technology and Innovations – MCTI of Brazil; Araucaria Foundation; and the General Superintendence of Science, Technology and Higher Education (SETI).info:eu-repo/semantics/publishedVersio

Multi-mobile robot and avoidance obstacle to spatial mapping in indoor environment

The advancement of technology and techniques applied to robotics contributes to increasing the quality of life and safety of humanity. One of the most widespread applications of mobile robotics is related to monitoring indoor environments. However, due to factors such as the size of the environment impacting the monitoring response, battery autonomy, and autonomous navigation in environments with unknown obstacles, they are still significant challenges in the diffusion of mobile robotics in these areas. Strategy adopting multiple robots can overcome these challenges. This work presents an approach to use multi-robots in hazardous environments with gas leakage to perform spatial mapping of the gas concentration. Obstacles arranged in the environment are unknown to robots, then a fuzzy control approach is used to avoid the collision. As a result of this paper, spatial mapping of an indoor environment was carried out with multi-robots that reactively react to unknown obstacles considering a point gas leak with Gaussian dispersion.This work has been supported by FCT - Fundação para a Ciência e Tecnologia within the Project Scope: UIDB/05757/2020. Additionally, this work was supported in part by the National Counsel of Technological and Scientific Development of Brazil (CNPq), in part by the Coordination for the Improvement of Higher Level People (CAPES).info:eu-repo/semantics/publishedVersio

As práticas do movimento cooperativo como lugares de eduucacâo

O foco temático deste artigo está nas práticas do movimento cooperativo como lugares de educação, tendo em seu cerne a pergunta sobre a relação entre cooperação e educação. O texto é oriundo de reflexões teórico-críticas a partir da experiência de atuação dos autores durante décadas junto a organizações cooperativas. Desse contexto surgem questionamentos relativos ao papel da educação em uma organização cooperativa. Objetiva-se potencializar o debate teórico e que este possa servir de instrumento prático ao movimento cooperativo. Conclusivamente observa-se que associados e associadas se educam nas relações sociais e econômicas da cooperação, podendo-se afirmar que o movimento cooperativo constitui um lugar de educaçãoThis article focuses on the practices of the cooperative movement as places of education. It has at its core the question of the relationship between cooperation and education. The text is derived from theoretical and critical reflections from the work of the authors' experience for decades with the cooperative organizations. In this context, some questions concerning the role of education in a cooperative organization arise. The objective is to enhance the theoretical debate and it can serve as a tool for practicing the cooperative movement. We observed that cooperative members educated themselves in the social and economic relations of cooperation, so that we can say the cooperative movement is a place of educatio

O USO DO MOODLE NA UFSC: DO APOIO AO ENSINO PRESENCIAL À GESTÃO UNIVERSITÁRIA

O objetivo desta pesquisa é investigar o potencial e o uso da ferramenta de ensino à distância Moodle, na forma de apoio ao ensino presencial, até a produção dos relatórios gerenciais e sua aplicação na administração universitária. A UFSC implantou um Moodle corporativo de apoio aos cursos presenciais, a partir da grande demanda do EaD, da disseminação cultural da ferramenta Moodle em nível mundial, bem como o do constante aprimoramento tecnológico desta plataforma, feito pelo grupo desenvolvedor. A criação de um grupo de suporte e a integração com o sistema acadêmico da UFSC foi disponibilizado, de forma efetiva, em 2009. A Superintendência de Governança Eletrônica e Tecnologia da Informação e Comunicação (SeTIC) disponibiliza suporte aos usuários e personaliza as funções de ajuda existentes no sistema. O Moodle integra-se os sistemas acadêmicos (CAGR/CAPG/CAPL) da UFSC o que facilita para os alunos e ao próprio setor de registro acadêmico, pois as informações são trocadas automaticamente entre os dois sistemas. Por exemplo, se todas as atividades de uma disciplina passarem pelo Moodle, no final do período acadêmico o Moodle faz a correção dos exercícios, calculando a nota final do aluno e permitindo o encaminhamento desta nota para o sistema acadêmico. Toda a comunidade acadêmica (alunos e professores) que utiliza o sistema acadêmico é cadastrada automaticamente no Moodle. Os investimentos em tecnologia da informação e comunicação (TIC) pela UFSC facilitaram o processo. Os principais resultados mostram a gradativa aceitação do padrão Moodle pela comunidade acadêmica, e mostram o pouco uso das informações gerenciais produzidas pelo sistema pelos administradores da UFSC

The Specific Heat of a Trapped Fermi Gas: an Analytical Approach

We find an analytical expression for the specific heat of a Fermi gas in a harmonic trap using a semi-classical approximation. Our approximation is valid for kT>hw and in this range it is shown to be highly accurate. We comment on the semi-classical approximation, presenting an explanation for this high accuracy.Comment: To be published in Physics Letters A. 7 pages (RevTex) and 2 figures (postscript