Investigação de parâmetros da emissão térmica em comprimentos de onda rádio como sonda da energia dos raios gama em novas clássicas

The study of Classical Novae over the last two decades has fastly changed due to the upgrade of radio telescopes, such as the Karl Jansky Very Large Array, and the advent of space-based γ-ray telescopes, such as Fermi. Multi-frequency studies of these objects are able to provide us detailed information about the physical conditions after eruptions enabling us to study the contributions of novae to their interstellar medium. Some, if not all, classical novae are predicted to release GeV γ-rays, although the origin of these emissions is yet to be fully understood. However, there are significant indications that it is connected to internal shocks within the ejected material, which also causes the non-thermal emission and dust production. The radio light curves of 7 classical novae (V959 Mon, V1324 Sco, V5668 Sgr, V357 Mus, V906 Car, V5589 Sgr, and V1723 Aql) were fitted with a spherically symmetric thermal emission model in this study, of which 2 are from previously unpublished data (V5668 Sgr and V357 Mus). The model is based on the “Hubble Flow Model” and is coupled with the Markov Chain Monte Carlo (MCMC) code, emcee. This is the first time the emcee code was coupled to fit radio light curves of novae. Non-thermal emission was clearly evident in the results of the fit, as expected from previous studies of these novae. In 6 out of the 7 novae the model was capable to decouple the two components of the emission. Of the 7 novae, only 5 were detected with γ-ray emission. This dissertation aims to identify connections between the thermal emission input parameters (distance, filling factor, maximum expansion velocity, and mass of ejecta) and the γ-ray brightness or the limit of nondetection. To date, attempts to find correlations between parameters at different wavelengths and γ-ray emission, or lack of, were met with various successes. We find an inverse correlation between the ejecta mass and the γ-ray luminosity. This inverse correlation is reminiscent of the attenuation of γ-ray photons by an absorbing screen (most likely the ejecta itself). The inverse correlation found between the γ-ray emission and ejected mass may also help explain the origin of the 102 factor observed in the values of detected γ-ray luminosit.O estudo de novas clássicas nas últimas duas décadas tem mudado rapidamente devido à melhoria de telescópios rádio, como o Karl Janky Very Large Array e novos telescópios espaciais de raios γ, como o Fermi. Estudos de multifrequências destes objetos são capazes de fornecer informação detalhada sobre as condições físicas durante erupções, permitindo o estudo das contribuições de novas no meio interestelar. Prevê-se que algumas, senão todas, as novas clássicas emitam raios γ com energia na ordem dos GeV. No entanto, a origem destas emissões não está ainda totalmente compreendida. Contudo, existe indicações significativas de que estão relacionadas com choques internos dentro do material expelido, que também causa emissão não-térmica e produção de poeira. Neste estudo, curvas de luz nas bandas de rádio de 7 novas clássicas (V959 Mon, V1323 Sco, V5668 Sgr, V357 Mus, V906 ´ Car, V5589 Sgr e V1723 Aql) foram ajustadas com um modelo de emissão térmica com simetria esférica, dos quais 2 são de dados não publicados (V5590 Sgr e V357 Mus). O modelo e baseado no “Hubble Flow Model” e está acoplado ao código de Monte Carlo de Cadeias de Markov, emcee. Esta e a primeira vez que o código emcee foi acoplado para fazer ajustes de curvas de luz nas bandas de rádio de novas. Emissão não-térmica estava claramente evidente nos resultados dos ajustes, como era de esperar tendo em conta resultados de estudos prévios. Em 6 de 7 novas, o modelo foi capaz de dissociar as duas ´ componentes de emissão. De 7 novas, apenas 5 foram detetadas em emissão de raios γ. Nesta dissertação pretende-se identificar conexões entre os parâmetros de entrada da radiação térmica (distância, fator de preenchimento, velocidade máxima de expansão e massa expelida) e o brilho de raios γ, ou o limite de não deteção. Até à data, tentativas para encontrar correlações entre parâmetros a diferentes comprimentos de onda e emissão de raios γ, ou falta dela, tiveram diversos graus de sucesso. Nós encontrámos uma correlação inversa entre a massa ejetada e a luminosidade de raios γ. Esta correlação inversa e remanescente da atenuação de fotões γ, por uma barreira absorvente (muito provavelmente o próprio material ejetado). A correlação inversa encontrada entre a emissão de raios γ e a massa expelida pode também ajudar a explicar o fator de 102 observado nos valores de luminosidade de raios γ.Mestrado em Físic

Maria Pia fecit / By Maria Pia: the observed and the observer. Some reflections on gender issues considering the case of Queen Maria Pia, the photographer

his article discusses some aspects of the status of women amateur photographers during the turn of the 19th to 20th centuries, considering the case of the Portuguese Queen Maria Pia of Savoy (1847-1911). We acknowledge the difficulties of making the historiography of women photographers in Portugal, due to the scarcity of sources and archives, and the lack of questions about these absences and their reasons. These facts have contributed to a history of photography in Portugal that consists of a succession of male names of “great photographers”. Asking questions about “the other half”, as well as broadening conceptions of photography to include the diversity of their practices may contribute to highlight the gender constructions raised by photographic practice. It also will help to understand the factors contributing to the limited  access of Portuguese women to this practice and the lack of their public visibility, during this period

Exploring the Feasibility and Limitations of Digital Product Passports in the Textile Industry: A Critical Assessment of Current Models

openThe European Commission defines the Digital Product Passport (DPP) as a structured collection of product-related data with a predetermined scope. It includes agreed-upon data ownership and access rights, facilitated by a unique identifier. This information is electronically accessible through a data carrier (Colledani and Abdalla, 2023). The DPP plays a crucial role in digitizing the industry along the value chain and has a broad impact on all life cycle stages. Its influence extends to shaping new legislative regulations, creating business opportunities, and refining strategies that contribute to a more effective circular economy. This involves determining how products are utilized, recycled, repurposed, and repaired. The data collected serves a dual purpose: aiding customers in making informed decisions and helping companies identify opportunities within their supply chain to align strategies with environmental needs. Currently, the textile sector is actively crafting a proposal for the DPP that aligns with the European Commission's requirements. This initiative aims to identify the most suitable proposal, which will subsequently pave the way for defining the next steps for the broader industry. Notably, the textile sector, recognized as one of the most environmentally impactful industries, is slated to implement DPP regulations by 2027. However, it's noteworthy that France has opted for an accelerated implementation, planning to enforce these regulations by 2024. This decision reflects a commitment to expedite the adoption of DPP regulations across the entire industry. This master thesis contributes to the ongoing discourse supporting the success of the DPP. The reader will gain insights into the DPP as both a system and a product. Additionally, the thesis delves into the definition of current data requirements for textiles, examines undefined elements, provides an overview of existing proposals and their distinctions, and proposes characteristics necessary for cohesive value propositions.The European Commission defines the Digital Product Passport (DPP) as a structured collection of product-related data with a predetermined scope. It includes agreed-upon data ownership and access rights, facilitated by a unique identifier. This information is electronically accessible through a data carrier (Colledani and Abdalla, 2023). The DPP plays a crucial role in digitizing the industry along the value chain and has a broad impact on all life cycle stages. Its influence extends to shaping new legislative regulations, creating business opportunities, and refining strategies that contribute to a more effective circular economy. This involves determining how products are utilized, recycled, repurposed, and repaired. The data collected serves a dual purpose: aiding customers in making informed decisions and helping companies identify opportunities within their supply chain to align strategies with environmental needs. Currently, the textile sector is actively crafting a proposal for the DPP that aligns with the European Commission's requirements. This initiative aims to identify the most suitable proposal, which will subsequently pave the way for defining the next steps for the broader industry. Notably, the textile sector, recognized as one of the most environmentally impactful industries, is slated to implement DPP regulations by 2027. However, it's noteworthy that France has opted for an accelerated implementation, planning to enforce these regulations by 2024. This decision reflects a commitment to expedite the adoption of DPP regulations across the entire industry. This master thesis contributes to the ongoing discourse supporting the success of the DPP. The reader will gain insights into the DPP as both a system and a product. Additionally, the thesis delves into the definition of current data requirements for textiles, examines undefined elements, provides an overview of existing proposals and their distinctions, and proposes characteristics necessary for cohesive value propositions

Mechanisms of Fruit Ripening: Retrospect and Prospects

This paper aims at giving an overview of the progress made during the last decades on the mechanisms of fruit ripening and to present the most recent trends and prospects for the future. Important steps forward will be presented (respiratory climacteric, ethylene biosynthesis and action, isolation of genes involved in the ripening process, biotechnological control of fruit ripening....) by showing how the judicious exploitation of the data published previously, the strategies, methodologies and plant material adopted have been crucial for the advancement of knowledge. Opportunities of co-operation between geneticists and post-harvest physiologists as well as new possibilities offered by genomics, proteomics and metabolomics for the understanding of the fruit ripening process and the development of sensory quality will be developed

Partial extinction did not diminish spontaneous recovery after 24-hour retention interval

Fear extinction is not permanent but it may suffer from different forms of relapse. One strategy potentially useful to diminish relapse is the partial extinction treatment, according to which, extinction may be potentiated if a gradual and sparse number of CS-US pairings are introduced within the extinction treatment. The present study, using a differential fear conditioning paradigm, tries to evaluate the efficacy of partial extinction to reduce a specific form of relapse, spontaneous recovery, after a 24 h. retention interval. The results showed that partial extinction did not diminish spontaneous recovery when compared with standard extinction. From a theoretical point of view, the pattern of results found was more consistent with the idea that extinction entails the acquisition of new knowledge than with the idea that there are conditions in which extinction entails the erasure of the original acquisitionUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Impacto de precálculo en cálculo

Al observar que los estudiantes no cuentan con los niveles mínimos necesarios para cursar la materia de Cálculo, se aplican actualmente dos criterios de selección a los estudiantes aspirantes a llevar estos cursos. Los criterios son: aprobar un instrumento de evaluación pre-requisitos o superar un curso propedéutico de precálculo. Este estudio se realiza con el fin de valorar la pertinencia de la aplicación de estos criterios y medir el impacto del curso propedéutico sobre el desempeño de los estudiantes en los cursos de Cálculo Diferencial (ingenierías) y Cálculo Diferencial e Integral (Licenciaturas en el área de negocios). Los resultados muestran una correlación significativa entre los resultados obtenidos en el curso de precálculo y el resultado en el curso de Cálculo