cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.14326420
title: Generalization of the least uncomfortable journey problem

description: Abstract The variational problem of the least uncomfortable journey between two locations on a straight line is simplified by a choice of the dependent variable. It is shown that taking the position, instead of the velocity, as the optimal function of time to be determined does away with the isoperimetric constraint. The same results as those found with the velocity as the dependent variable are obtained in a simpler and more concise way. Next the problem is generalized for motion on an arbitrary curve. In the case of acceleration-induced discomfort, it is shown that, as expected, motion on a curved path is always more uncomfortable than motion on a straight line. It is not clear that this is necessarily the case for jerk-induced discomfort, which appears to indicate that the acceleration provides a more reasonable measure of the discomfort than the jerk. The example of motion on a circular path is studied. Although we have been unable to solve the problem analytically, approximate solutions have been constructed by means of trial functions and the exact solution has been found numerically for some choices of the relevant parameters.
DOI: 10.6084/m9.figshare.14326420.v1
title: Generalization of the least uncomfortable journey problem

description: Abstract The variational problem of the least uncomfortable journey between two locations on a straight line is simplified by a choice of the dependent variable. It is shown that taking the position, instead of the velocity, as the optimal function of time to be determined does away with the isoperimetric constraint. The same results as those found with the velocity as the dependent variable are obtained in a simpler and more concise way. Next the problem is generalized for motion on an arbitrary curve. In the case of acceleration-induced discomfort, it is shown that, as expected, motion on a curved path is always more uncomfortable than motion on a straight line. It is not clear that this is necessarily the case for jerk-induced discomfort, which appears to indicate that the acceleration provides a more reasonable measure of the discomfort than the jerk. The example of motion on a circular path is studied. Although we have been unable to solve the problem analytically, approximate solutions have been constructed by means of trial functions and the exact solution has been found numerically for some choices of the relevant parameters.
DOI: 10.6084/m9.figshare.14326421.v1
title: On periodic potentials on simple cubic lattice

description: Abstract This text is a simple adaptation of the characterization via Fourier series of a class of periodic potentials to the simple cubic lattice, originally developed in the honeycomb lattice, rigorously treating both the potential type properties and the nature properties of the lattice space.
DOI: 10.6084/m9.figshare.14326421
title: On periodic potentials on simple cubic lattice

description: Abstract This text is a simple adaptation of the characterization via Fourier series of a class of periodic potentials to the simple cubic lattice, originally developed in the honeycomb lattice, rigorously treating both the potential type properties and the nature properties of the lattice space.
DOI: 10.6084/m9.figshare.14326423
title: Epidemic spreading

description: We present an analysis of six deterministic models for epidemic spreading. The evolution of the number of individuals of each class is given by ordinary differential equations of the first order in time, which are set up by using the laws of mass action providing the rates of the several processes that define each model. The epidemic spreading is characterized by the frequency of new cases, which is the number of individuals that are becoming infected per unit time. It is also characterized by the basic reproduction number, which we show to be related to the largest eigenvalue of the stability matrix associated with the disease-free solution of the evolution equations. We also emphasize the analogy between the outbreak of an epidemic with a critical phase transition. When the density of the population reaches a critical value the spreading sets in, a result that was advanced by Kermack and McKendrick in their study of a model in which the recovered individuals acquire permanent immunization, which is one of the models analyzed here.
DOI: 10.6084/m9.figshare.14326423.v1
title: Epidemic spreading

description: We present an analysis of six deterministic models for epidemic spreading. The evolution of the number of individuals of each class is given by ordinary differential equations of the first order in time, which are set up by using the laws of mass action providing the rates of the several processes that define each model. The epidemic spreading is characterized by the frequency of new cases, which is the number of individuals that are becoming infected per unit time. It is also characterized by the basic reproduction number, which we show to be related to the largest eigenvalue of the stability matrix associated with the disease-free solution of the evolution equations. We also emphasize the analogy between the outbreak of an epidemic with a critical phase transition. When the density of the population reaches a critical value the spreading sets in, a result that was advanced by Kermack and McKendrick in their study of a model in which the recovered individuals acquire permanent immunization, which is one of the models analyzed here.
DOI: 10.25345/c56z35
title: MassIVE MSV000087110 - negative acox-1.1 C. elegans metabolome
title: detected metabolome of acox-1.1 C. elegans mutants
DOI: 10.6084/m9.figshare.14326424
title: A didactic proposal for the study of magnetic interaction between magnets and some epistemological considerations

description: Abstract The force of magnetic interaction between magnets is a curious effect, which attracts the attention of people of the most varied ages. If, on the one hand, its description is too tricky to be presented in basic physics courses, on the other, restricting some aspects of the magnets, the force admits a behavior described analytically by an exponential decay with the distance between the magnets. We present, then, a sequence of experiments that allows us to estimate the repulsion force between pairs of equal cylindrical magnets. Forgetting for a while this pragmatic side, we also discuss how a magnetic field admits its representation as an axial vector field.
DOI: 10.6084/m9.figshare.14326424.v1
title: A didactic proposal for the study of magnetic interaction between magnets and some epistemological considerations

description: Abstract The force of magnetic interaction between magnets is a curious effect, which attracts the attention of people of the most varied ages. If, on the one hand, its description is too tricky to be presented in basic physics courses, on the other, restricting some aspects of the magnets, the force admits a behavior described analytically by an exponential decay with the distance between the magnets. We present, then, a sequence of experiments that allows us to estimate the repulsion force between pairs of equal cylindrical magnets. Forgetting for a while this pragmatic side, we also discuss how a magnetic field admits its representation as an axial vector field.
DOI: 10.6084/m9.figshare.14326426.v1
title: Tem Menina no Circuito: data and results after five years

description: Abstract A common scenario to be observed in the exact sciences courses of several universities around Brazil is a room composed mostly of male students. What we see is intense segregation by gender in higher education areas: men predominate in the exact sciences, while women continue professionalizing in health sciences or basic education. Some social aspects may contribute to this segmentation, such as girls being less exposed than boys to subjects related to Physics. As a way of encouraging female high school students to see Physics and other areas of the exact and natural sciences as a career opportunity, the “Tem Menina no Circuito” project was created in 2014, and has been developed since then. In order to understand the project’s influences and contributions from 2014 to 2019, a questionnaire was distributed to the project’s participants. As a conclusion, it was observed that the students’ previous education seems to have influence over their career choice and that the project makes the students look to other areas of expertise as possibilities which were previously unknown to them.
DOI: 10.6084/m9.figshare.14326426
title: Tem Menina no Circuito: data and results after five years

description: Abstract A common scenario to be observed in the exact sciences courses of several universities around Brazil is a room composed mostly of male students. What we see is intense segregation by gender in higher education areas: men predominate in the exact sciences, while women continue professionalizing in health sciences or basic education. Some social aspects may contribute to this segmentation, such as girls being less exposed than boys to subjects related to Physics. As a way of encouraging female high school students to see Physics and other areas of the exact and natural sciences as a career opportunity, the “Tem Menina no Circuito” project was created in 2014, and has been developed since then. In order to understand the project’s influences and contributions from 2014 to 2019, a questionnaire was distributed to the project’s participants. As a conclusion, it was observed that the students’ previous education seems to have influence over their career choice and that the project makes the students look to other areas of expertise as possibilities which were previously unknown to them.
DOI: 10.6084/m9.figshare.14326430
title: Measuring the Stokes' parameters: A new practice for teaching optics

description: Abstract Here, we implement a physics teaching laboratory practice that aims to investigate the Stokes parameters through the analysis of polarized light transmitted by polarizing optical elements. The practice was implemented according to the project-based learning methodology. All the investigated states of polarized light were generated using a homemade polarization simulator, comprising a light source (laser emitting at 670 nm) combined with different polarizing optical elements. We have shown that the practice is effective for obtaining the Stokes' parameters. Moreover, it can be easily designed as an advanced experimental project for optics teaching laboratories, with the purpose of confirming and advancing theoretical studies of the topic.
DOI: 10.6084/m9.figshare.14326430.v1
title: Measuring the Stokes' parameters: A new practice for teaching optics

description: Abstract Here, we implement a physics teaching laboratory practice that aims to investigate the Stokes parameters through the analysis of polarized light transmitted by polarizing optical elements. The practice was implemented according to the project-based learning methodology. All the investigated states of polarized light were generated using a homemade polarization simulator, comprising a light source (laser emitting at 670 nm) combined with different polarizing optical elements. We have shown that the practice is effective for obtaining the Stokes' parameters. Moreover, it can be easily designed as an advanced experimental project for optics teaching laboratories, with the purpose of confirming and advancing theoretical studies of the topic.
DOI: 10.6084/m9.figshare.14326432
title: Use of an automatic device for the determination of mechanical properties on photoelastic samples of small dimensions

description: Abstract Photoelastic materials and Photoelasticity have been very effective in the study of the effects of stress and strain in materials such as iron, steel, concrete, etc. However, mainly because of human interaction, systematic errors are introduced during the measurement process, which directly affects the final result. When using small photoelastic samples, these types of errors can escalate due to the increased difficulty of handling. Intending to minimize systematic errors in the process of data collection, this work presents the use of an automatic loading device, developed by us, to apply mechanical stresses in small photoelastic samples. The device created has shown great effectiveness in photoelastic applications that uses a transmission polariscope, but it can also be used in other photoelastic techniques, such as reflection photoelasticity, as well as in other areas of optics such as Holography and Speckle. An important benefit is the ease and speed of handling that can improve the organization and quality of the activities in labs of optics.
DOI: 10.6084/m9.figshare.14326432.v1
title: Use of an automatic device for the determination of mechanical properties on photoelastic samples of small dimensions

description: Abstract Photoelastic materials and Photoelasticity have been very effective in the study of the effects of stress and strain in materials such as iron, steel, concrete, etc. However, mainly because of human interaction, systematic errors are introduced during the measurement process, which directly affects the final result. When using small photoelastic samples, these types of errors can escalate due to the increased difficulty of handling. Intending to minimize systematic errors in the process of data collection, this work presents the use of an automatic loading device, developed by us, to apply mechanical stresses in small photoelastic samples. The device created has shown great effectiveness in photoelastic applications that uses a transmission polariscope, but it can also be used in other photoelastic techniques, such as reflection photoelasticity, as well as in other areas of optics such as Holography and Speckle. An important benefit is the ease and speed of handling that can improve the organization and quality of the activities in labs of optics.
DOI: 10.6084/m9.figshare.14326433
title: Pac-Man Josephson junctions: useful trigonometric puzzles?

description: Abstract Rather interesting trigonometric equations arise when considering a Josephson junction obtained by embedding a Pac-Man shaped superconducting island in between two superconducting electrodes. In the present work we unfold these equations, written in terms of the superconducting phase difference between the two electrodes, and find the current-phase relation and the maximum superconducting current of the Josephson junction network. The solution of the trigonometric equations defining the superconducting current state of the system can be proposed to advanced high-school students or to undergraduate students in an interdisciplinary lecture.
DOI: 10.6084/m9.figshare.14326433.v1
title: Pac-Man Josephson junctions: useful trigonometric puzzles?

description: Abstract Rather interesting trigonometric equations arise when considering a Josephson junction obtained by embedding a Pac-Man shaped superconducting island in between two superconducting electrodes. In the present work we unfold these equations, written in terms of the superconducting phase difference between the two electrodes, and find the current-phase relation and the maximum superconducting current of the Josephson junction network. The solution of the trigonometric equations defining the superconducting current state of the system can be proposed to advanced high-school students or to undergraduate students in an interdisciplinary lecture.
DOI: 10.6084/m9.figshare.14326438
title: Gauge theories via Shaw-Deser

description: Abstract The aim of this work is to present and discuss the Shaw-Deser methodology to describe the interaction between matter and radiation by gauge symmetry (abelian/non-abelian). Between the lines, the message we intend to convey is how the “ fingerprint ” of local gauge symmetry is contained in global gauge symmetry, through a current-field interaction (Dirac/Schwinger) and a more algebraic (iterative) analysis, complementing the geometrical approach of Yang-Mills/Utiyama.
DOI: 10.6084/m9.figshare.14326438.v1
title: Gauge theories via Shaw-Deser

description: Abstract The aim of this work is to present and discuss the Shaw-Deser methodology to describe the interaction between matter and radiation by gauge symmetry (abelian/non-abelian). Between the lines, the message we intend to convey is how the “ fingerprint ” of local gauge symmetry is contained in global gauge symmetry, through a current-field interaction (Dirac/Schwinger) and a more algebraic (iterative) analysis, complementing the geometrical approach of Yang-Mills/Utiyama.
DOI: 10.6084/m9.figshare.14326439
title: Applications of the numerical calculation for a resolution of transcendent equations in quantum mechanics

description: Abstract Many students of physics and of certain courses of engineering are faced with the discipline of numerical calculation, developing it in a purely abstract way. In this way, this work aims at the use of numerical calculus as a tool to solve problems involving quantum mechanics in order to demonstrate in practice its application in obtaining and analyzing results in two specific problems: ( i ) The double well symmetric potential δ ( x ). ( i i ) And the square well infinite potential with a centered potential barrier, type δ ( x ). For these two cases we show that the possible solutions of allowed energies can be obtained by the numerical calculation, specifically by the method of the bisection. We also show that the parity of the wave function interferes directly in the allowed states and the effects on the particle subjected to these two potentials.
DOI: 10.6084/m9.figshare.14326439.v1
title: Applications of the numerical calculation for a resolution of transcendent equations in quantum mechanics

description: Abstract Many students of physics and of certain courses of engineering are faced with the discipline of numerical calculation, developing it in a purely abstract way. In this way, this work aims at the use of numerical calculus as a tool to solve problems involving quantum mechanics in order to demonstrate in practice its application in obtaining and analyzing results in two specific problems: ( i ) The double well symmetric potential δ ( x ). ( i i ) And the square well infinite potential with a centered potential barrier, type δ ( x ). For these two cases we show that the possible solutions of allowed energies can be obtained by the numerical calculation, specifically by the method of the bisection. We also show that the parity of the wave function interferes directly in the allowed states and the effects on the particle subjected to these two potentials.
DOI: 10.6084/m9.figshare.14326441
title: Synchronization of pendulum clocks and metronomes: a qualitative treatment

description: Abstract Pendulum clocks and metronomes have in common the fact that they are self-excited oscillators, exhibiting stationary oscillations where an external energy input compensates losses due to damping. In the phase plane these oscillations are represented by closed trajectories called limit cycles, and the motion along them can be parameterized by a phase angle. In this work we investigate the dynamics resulting from the coupling between two phase oscillators, using average equations for the resonant cases. The results from this analysis are used to qualitatively describe phase locking and synchronization phenomena in phase oscillators, explaining results observed in the coupling of pendulum clocks and metronomes.
DOI: 10.6084/m9.figshare.14326441.v1
title: Synchronization of pendulum clocks and metronomes: a qualitative treatment

description: Abstract Pendulum clocks and metronomes have in common the fact that they are self-excited oscillators, exhibiting stationary oscillations where an external energy input compensates losses due to damping. In the phase plane these oscillations are represented by closed trajectories called limit cycles, and the motion along them can be parameterized by a phase angle. In this work we investigate the dynamics resulting from the coupling between two phase oscillators, using average equations for the resonant cases. The results from this analysis are used to qualitatively describe phase locking and synchronization phenomena in phase oscillators, explaining results observed in the coupling of pendulum clocks and metronomes.
DOI: 10.6084/m9.figshare.14326445
title: An overview of kinetic theory in plasma physics to obtain a specific form of the Grad-Shafranov equation

description: This article aims to present a theoretical formulation in the area of plasma physics to obtain a specific form of the Grad-Shafranov equation, in other words, to obtain the Ampère-Maxwell law as a function of the magnetic vector potential and current density. We seek to better understand some phenomena that occur in interplanetary plasma. Another objective is to present this theme in a didactic way as clearly and concisely as possible. In particular, a mathematical development takes place as an introduction to the work, showing the equations we want to deduce, with each section we build a theoretical basis in plasma physics, using concepts of thermodynamics and the universal laws of physics, as well as mathematics, culminating in the Grad-Shafranov specific equation. Finally, we present one of the best known solutions for the Grad-Shafranov equation, as well as references for those who want to delve into the subject.
DOI: 10.6084/m9.figshare.14326445.v1
title: An overview of kinetic theory in plasma physics to obtain a specific form of the Grad-Shafranov equation

description: This article aims to present a theoretical formulation in the area of plasma physics to obtain a specific form of the Grad-Shafranov equation, in other words, to obtain the Ampère-Maxwell law as a function of the magnetic vector potential and current density. We seek to better understand some phenomena that occur in interplanetary plasma. Another objective is to present this theme in a didactic way as clearly and concisely as possible. In particular, a mathematical development takes place as an introduction to the work, showing the equations we want to deduce, with each section we build a theoretical basis in plasma physics, using concepts of thermodynamics and the universal laws of physics, as well as mathematics, culminating in the Grad-Shafranov specific equation. Finally, we present one of the best known solutions for the Grad-Shafranov equation, as well as references for those who want to delve into the subject.
DOI: 10.6084/m9.figshare.14326447
title: Determining the efficiency of a Stirling engine using Arduino: a proposal for teaching thermodynamics in introductory courses

description: During the last few years, research in physics education has highlighted the interest of the Arduino platform and its associated sensors in improving teaching. In this paper we present a proposal for the study of thermodynamics in introductory courses. We have built a home-made Stirling engine with low-cost materials. From a theoretical study of the thermodynamic cycle associated to the engine, we propose several strategies to measure its efficiency. Next, we describe the experimental setup, based on Arduino sensors, that allows us to record the necessary measurements to develop the proposed strategies. The results obtained show the low efficiency of thermal engines and the differences between the theoretical and experimental thermodynamic cycles.