The ancient problem of tides, phenomena observed since the humanity early days, still today provides important analysis. In this work, starting with the study of tides, but considering the law gravity, we determine Moon’s characteristics, such as mass, volume, and some aspects of its chemical composition. This approach is carried out by using an inverse-like method, proposed by Henrique Fleming. The formulation provides a way to revisit the Galilei qualitative studies about tides, starting exclusively from the Earth motion. We point out the importance of galilean formulation, what is under criticism in some studies.

O antigo problema das marés, fenômeno observado desde os primórdios da humanidade, ainda nos lega análises importantes. Nesse trabalho, a partir do estudo desse fenômeno, mas levando em conta a gravitação, determinamos características da Lua, tais como como a massa, volume e aspectos da composição química. Essa determinação é feita usando um tipo de método inverso, proposto por Henrique Fleming. Essa abordagem nos permite reexaminar a análise qualitativa de Galilei sobre o problema, partindo exclusivamente dos movimentos da Terra. Apontamos para a importância da formulação galileana, criticada em certos estudos.

ABSTRACT: Soil enzymes play a fundamental role in nutrient cycling in forest systems. The stoichiometry of C, N, and P–acquiring enzymes has been used to indicate nutrient limitation in the soil. However, the enzymatic stoichiometry remains poorly understood in pure and mixed eucalypt plantations. Thus, this study aims to assess the activity of enzymes in the soil to address the hypothesis that the introduction of N2-fixing trees could influence the enzymatic stoichiometry on C, N, and P cycling. The activity of β-glucosidase (BG), urease (U), and acid phosphatase (AP) was assessed in soil (0-20 cm depth) of pure Eucalyptus grandis without (E) and with N fertilization (E+N), and a mixed system with E. grandis and Acacia mangium (E+A), and a pure A. mangium (A) plantation at 27 and 39 months after planting. The activities of BG/U, BG/AP, and U/AP were used to calculate the enzyme C/N, C/P, and N/P ratios, respectively. Rates of N–acquiring enzymes were higher in E and E+N, while soil microorganisms invested in P–acquiring enzymes in A and E+A. The vector length and angle demonstrated that C demand by microorganisms does not change in relation to N and P, regardless of the treatment. However, N demand decreased in relation to P in A and E+A (mainly at 27 months). Our results suggest that enzymes activity in pure eucalypt systems is limited for their soil-litter nutrient contents. At the same time while acacia and mixed plantation seem to invest in P–acquiring enzymes to improve biological N2 fixation promoted by diazotrophic bacteria associated to acacia.

Abstract This article performs an analysis of female participation in science, in the Brazilian system of graduate studies and scientific research as a case study. This is relevant because science is a central supporting structure for modern societies and, therefore, a detailed analysis of the scientific power structure behind academic policy creation can reveal aspects of androcentrism in scientific activity. The main goal of this work is to identify the process of misogyny in science by describing its reproductive pattern. Our results show that women are around 50% of the undergraduate and graduate students when all fields are taken into consideration, but only 37% of the researchers in the CNPq system. We also observe a significant increase in female percentage within scientific activities at the initial and intermediary levels, except for the most prestigious areas as hard science. However, a scissor effect is identified between the initial level and the more prominent positions. This unbalanced participation reveals that female occupations in science are mostly as lower workforce since women are quite far from the social decision-making circles in this career

A mecânica quântica é aqui construída a partir de elementos constitutivos gerais com ênfase nos aspectos experimentais que fundam a teoria. A presente abordagem estabelece como pontos de partida as definições de sistemas de referências e a estrutura do espaço tempo, a natureza das simetrias e dos sistemas de referência, a noção de estado e as relações causais entre estados diferentes, o que leva a equação de Schrödinger. Um aspecto importante é que a mecânica quântica é decodificada como uma teoria de campo; nesse sentido o conceito de ponto material é descrito. A abordagem tem sido aplicada com sucesso em cursos de Pós-gradução do Mestrado Nacional Profissionalizante em Ensino de Física e se mostra muito eficiente na discussão dos fundamentos da mecânica quântica, em particular quanto às bases experimentais da teoria.

In this paper, the quantum mechanics is presented from general constitutive elements with emphasis on the experimental aspects that support the theory. This approach establishes as starting points the definitions of reference systems and the structure of the space time, the nature of symmetries and reference systems, the notion of state and the causal relationships between different states, which leads to the Schrödinger equation. A crucial aspect is that the quantum mechanics is decoded as a field theory, in which meaning the concept of material point is described. The approach has been successfully applied in post-graduate courses of the National Professional Master?s Degree in Physics Teaching and proves very efficient in discussing the fundamentals of quantum mechanics, in particular as the experimental pillars of the theory.

Abstract The transformation of women’s role in society has been systematically studied. Numerous authors point out that among the factors of extreme relevance to this fact, the main is the increased presence of women in the formal job market. Researches also reveal that the increase in quantity is not reflected equally in all productive sectors nor the egalitarian occupation of high hierarchical positions. The present study aimed to analyze how the presence of women, especially in leadership positions, has evolved at the Brazilian Federal Agency for the Support and Evaluation of Postgraduate Education (CAPES) and the National Council for Scientific and Technological Development (CNPq) over the last 20 years. For these analyzes, surveys were conducted in the people management systems of the Brazilian Federal Public Administration. The initial hypothesis was that female attendance had increased in both the total number of female servants and in management and auxiliary positions, known as DAS in Brazil; however, evidence shows that women reduced overall agency presence, especially in the number of female Analysts occupying DAS positions. These results indicate that the misogyny observed in the academic sphere of the Brazilian National Postgraduate and Science, Technology, and Innovation systems are replicated in the politic-bureaucratic sphere that manages and sponsors these systems.

Resumo O teorema de Nöther é revisitado com dois objetivos: ressaltar a significado desses resultados para a física contemporânea e ao mesmo tempo apresentar aspectos da biografia de Emmy Nöther, enfatizando a misoginia sofrida na sua atividade científica, a despeito da reconhecida importância, ainda em vida, de seus trabalhos. Sob esta perspectiva, a vida de Emmy Nöther levanta a questão sobre a situação atual da atuação da mulher em ciência. Esse aspecto é abordado através de uma análise da participação de mulheres atuando em ciências com dados do CNPq e da CAPES. Para discutir e apresentar a dimensão apropriada dos resultados principais de Emmy Nöther, contextualizando a importância na física contemporânea, um caminho algébrico é seguido (nos livros textos, os teoremas são apresentados através do formalismo Lagrangiano), mas tanto quanto possível procurando uma abordagem discurso pedagógica.

Abstract The Nöther's theorem is revisited with two main goals: to reinforce the meaning of such results for the contemporary physics and to present aspects of the Nöther's biography emphasizing the misogyny process that she suffered during her scientific life, despite of the recognized importance of her results even when she was alive. Under this perspective, the Nöther's live raises questions about the present-day participation of women in science. This aspect is addressed by an analysis of female researchers, by using data from CNPq and CAPES (two Brazilian Government agencies). In order to discuss and to present a proper dimension of the Nöther results, emphasizing such results for physics, an algebraic way is followed (usually such results are derived through the Lagrangian formalism); however, as much as possible, looking for a pedagogical presentation.

A nonequilibrium statistical operator (NSO) is built for classical sistems using a field theory in classical phase space, which is but a classical version of the thermofield dynamics formalism. The approach developed here starts with a second-quantized version of this phase-space field theory. Then elements of symmetry are analysed and invariants of the theory are introduced. The local conservation laws are derived and used to make explicit NSO. Such a method is applied to derive the Fokker-Planck-Kramers equation.