A5011495587- Magnetic Properties of Alloys
- Rare-earth and actinide compounds
- Magnetic and transport properties of perovskites and related materials
- Planetary Science and Exploration
- Astro and Planetary Science
- Magnetic properties of thin films
- Stellar, planetary, and galactic studies
- Experimental Learning in Engineering
- Education and Digital Technologies
- Science and Education Research
- Business and Management Studies
- Nuclear Physics and Applications
- Geotechnical and Geomechanical Engineering
- Photovoltaic System Optimization Techniques
- Pigment Synthesis and Properties
- Science Education and Pedagogy
- Educational Strategies and Epistemologies
- Neural Networks and Applications
- Mineral Processing and Grinding
- Isotope Analysis in Ecology
- Time Series Analysis and Forecasting
- Mineralogy and Gemology Studies
- Iron Metabolism and Disorders
- Material Science and Thermodynamics
- Experimental and Theoretical Physics Studies
Universidade do Porto
2011-2024
University of Coimbra
2013-2024
Measuring one physical quantity as a function of another often requires making some choices prior to the measurement process. Two these are: data range where measurements should focus and number (n) points acquire in chosen range. Here, we consider interval variation independent variable (x) that is associated with given dependent (y). We analyzed role width lower endpoint on parameter estimation by linear regression. show that, when feasible, increasing more effective than same reducing...
The specific heat (C(T)) of Gd4Co3 was measured in the temperature range 2–300 K and its magnetic contribution (Cm(T)) determined using a new method that fits electronic coefficient (γ) Debye (θD) by constraining resulting entropy (Sm(T)) to saturate at temperatures far above Curie (TC). Cm(T) exhibits low-temperature bump originating from thermal excitation gapped spin waves, which is responsible for pronounced peaks, ≈35 K, both Cm/T derivative electrical resistivity (dρm/dT). Apart...
In order to study the effects caused by substituting Co for Cu on electronic and transport properties of Gd4(Co1−xCux)3 compounds with x=0.05, 0.1, 0.2, 0.3, electrical resistivity [ρ(T)] measurements were performed in temperature range 12–300K. The paramagnetic-ferrimagnetic spin-reorientation transitions are marked clear anomalies dρ∕dT. For x=0.2, however, onset ferrimagnetic at TC produces just a comparatively small peak This fact is compatible hypothetical mixed phase exhibiting partial...
We present a study of the spin disorder resistivity ([Formula: see text]) and electronic specific heat coefficient (γ) in Gd(4)(Co(1-x)Cu(x))(3) compounds, with x = 0.00, 0.05, 0.10, 0.20 0.30. The experimental results show strongly nonlinear dependence [Formula: text] on average de Gennes factor (G(av)) which, similar intermetallic is usually attributed to existence fluctuations Co 3d bands. Values γ were found around 110 mJ mol(-1) K(-2) for much larger than 38.4 isostructural nonmagnetic...
Abstract This work describes an exact radiometric model for experimental demonstrators of the detection exoplanets by transit method. generalises calculation depth occultation from standard method to case a finite size demonstrator apparatus. Results show that, apparatuses moderately small sizes, significant accuracy improvement in determination planet can be achieved using proposed comparison formula The radiance distribution star is found crucial importance, as deviations Lambertian lead...
The spectacular progress of space exploration during the last 30 years has allowed developmentof Planetary Geosciences, an intrinsically interdisciplinary field sciences joining together geologists,geophysicists, geochemists, etc. Master degree courses in astrophysics and planetary geosciences areattracting more graduates with a great diversity backgrounds covering physics, earthsciences, engineering, mathematics. It is, therefore, important to promote these courses,highlighting not only...
We describe a method for the exact data linearization of charging curve capacitor. The calculations required are as simple those involved in discharging curve, allowing analysis process using graphical and fitting tools available introductory physics courses. proposed can also be generalized to university-level problems involving biased exponential curves an input parameter estimation nonlinear procedures.
We report results of thermoelectric power measurements (S(T)) in ferrimagnetic Gd4(Co1-xCux)3 compounds with x = 0.05, 0.1, 0.2, and 0.3, the temperature range 8–300 K. Whereas Gd4Co3, S(T) is always negative, for > 0 substitution Co Cu gives rise to appearance a low positive maximum at around 30 Based on our previous study these compounds, we argue that this originates from electron-magnon scattering sensitive electron band structure changes resulting accompanying reduction ratio...
In order to study the effects caused by substituting Co for Cu on magnetic properties of Gd4(Co1−xCux)3 compounds with x=0.05, 0.1, 0.2, and 0.3, superconducting quantum interference device magnetization measurements were performed polycrystalline samples in temperature range 5–300 K using applied fields from 0 5 T. Experimental results show that substitution produces an increase anisotropy, which is accompanied important changes ordering these ferrimagnetic respect Gd4Co3. A T-x phase...
The ammeter-voltmeter method is a general for measuring electrical resistances that widely used in the introductory physics laboratory, mostly pedagogical reasons. Simultaneous readings of current (I) and voltage (V) allow calculation resistance (R) using Ohm’s law: R = V/I. It implicitly assumed wire contact present circuit can be neglected. Two configurations are usually proposed, depending on relative values internal ammeter voltmeter. In this work, we highlight deficiencies standard...
When conducting experiments involving the measurement of physically related quantities, choosing an appropriate spacing for experimental independent variable is a crucial procedure whose consequences may go beyond data graphical visualization. This particularly true if measured quantities are nonlinearly and errors nonuniform. In this work, we show that procedures should provide higher density points in range where larger, to more effectively average out random thus mitigate accuracy...
We propose a method for formative assessment of laboratory work which provides running updated diagnostic the student performance and skills in all predefined areas sub-areas. The is easily adaptable to any type report or assessment, provided that graded profile can be defined.
In this work, a meteorite sample recovered in Morocco is characterized by detailed petrographic observations transmitted and reflected light optical microscopy using XRD SEM it tentatively classified. VIS/NIR spectral analysis of the same previous study suggested that seemingly related to HAMLET meteorite, which was classified as LL4 chondrite. From obtained results refinement present study, L4 L5 Composition maps across selected chondrules matrix are presented.
The aim of our study is to find out the attitude students towards use cooperative learning with whiteboarding in an undergraduate introductory Physics course at Department and Astronomy Faculty Science University Porto. We used online survey face-to-face-classroom observations as a supporting tool collect data. was based on multiple choice questions titled “Attitude Towards Cooperative Learning Whiteboarding Introductory Physics” (ATCLWIP), 5-point Likert scale, format strongly disagree,...