Quebradores, dobradores e obedientes: Explorando a mediação de edTPA dos formadores de professores

This article reflects a qualitative exploratory inquiry into the lived experiences of faculty members working within a system of urban schools of education as they supported diverse teacher candidates in completing the Educative Teacher Performance Assessment (edTPA) during its first semesters of high-stakes implementation. Drawing upon questionnaire responses and semi-structured interviews, our findings demonstrate the disparity and variation in the level and kind of support offered to teacher candidates. We discuss the ways that the policy, stance, and the ethical, pedagogical, and logistical dilemmas teacher educators faced as they supported candidates intersected to shape the supports provided. Implications focus on utilization of such test scores for evaluating teacher preparation institutions, faculty relations, and the diversification of the teacher workforce. Este artículo refleja una investigación exploratoria cualitativa sobre las experiencias de vida de formadores  de docentes trabajando en escuelas urbanas mientras apoyaban a candidatos a maestros para completar el programa de Evaluación del Desempeño Educativo (edTPA) durante los primeros semestres de implementación de esta propuesta de consecuencias severas. Nuestros resultados basados en respuestas al cuestionario y entrevistas semiestructuradas, muestran la disparidad y la variación en el nivel y el tipo de apoyo ofrecido a los futuros docentes. Se analizan las formas en que los posicionamientos políticos, éticos, pedagógicos y dilemas logísticos que enfrentaban los formadores de docentes influenciaban como apoyaban a los  futuros docentes. Las conclusiones se centran en la utilización de resultados de este tipo de pruebas para la preparación docentes, la evaluación de las instituciones, las relaciones con los formadores docentes y la diversidad entre los docentes. Este artigo presenta uma pesquisa exploratória qualitativa sobre as experiências de vida dos formadores de professores que trabalham em escolas urbanas, apoiando futuros docentes no processo de completar a avaliação do programa do Rendimento Escolar (edTPA) durante o primeiro semestre de aplicação da presente proposta com consequências severas. Nossos resultados com base nas respostas ao questionário e entrevistas semiestruturadas mostram a disparidade e variação do nível e tipo de suporte oferecido aos futuros professores. as maneiras pelas quais os formadores docentes enfrentavam os dilemas políticos, éticos, educacionais e logísticos influenciava os apoios oferecidos aos futuros professores. Os resultados focam na utilização dos resultados de tais testes para preparação de professores, avaliação das instituições, as relações com formadores de professores e diversidade entre os professores

Optimization of lumping schemes for plane square quadratic finite element in elastodynamics

The effectiveness of explicit direct time-integration methods is conditioned by using diagonal mass matrix which entails significant computational savings and storage advantages. In recent years many procedures that produced diagonally lumped mass matrices were developed. For example, the row sum method and diagonal scaling method (HRZ procedure) can be mentioned. In this paper, the dispersive properties of different lumping matrices with variable mass distribution for the plane square 8-node serendipity elements are investigated. The dispersion diagrams for such lumping matrices are derived for various Courant numbers, wavelengths and the directions of wave propagation

Dispersion of elastic waves in the contact–impact problem of a long cylinder

AbstractNumerical dispersion of two-dimensional finite elements was studied. The outcome of the dispersion study was verified by the numerical and analytical solutions to the longitudinal impact of two long cylindrical bars. In accordance with the results of the dispersion analysis it was demonstrated that the quadratic elements showed better accuracy than the linear ones

Simultaneous Border-Collision and Period-Doubling Bifurcations

We unfold the codimension-two simultaneous occurrence of a border-collision bifurcation and a period-doubling bifurcation for a general piecewise-smooth, continuous map. We find that, with sufficient non-degeneracy conditions, a locus of period-doubling bifurcations emanates non-tangentially from a locus of border-collision bifurcations. The corresponding period-doubled solution undergoes a border-collision bifurcation along a curve emanating from the codimension-two point and tangent to the period-doubling locus here. In the case that the map is one-dimensional local dynamics are completely classified; in particular, we give conditions that ensure chaos.Comment: 22 pages; 5 figure

Full Field Computing for Elastic Pulse Dispersion in Inhomogeneous Bars

In the paper, the finite element method and the finite volume method are used in parallel for the simulation of a pulse propagation in periodically layered composites beyond the validity of homogenization methods. The direct numerical integration of a pulse propagation demonstrates dispersion effects and dynamic stress redistribution in physical space on example of a one-dimensional layered bar. Results of numerical simulations are compared with analytical solution constructed specifically for the considered problem. Analytical solution as well as numerical computations show the strong influence of the composition of constituents on the dispersion of a pulse in a heterogeneous bar and the equivalence of results obtained by two numerical methods

Corrosion and Electrochemical Properties of Laser-Shock-Peening-Treated Stainless Steel AISI 304L in VVER Primary Water Environment

Laser Shock Peening (LSP) is a surface treatment technique for metallic materials. It induces plastic deformation at the surface of up to around 1 mm in depth. This process introduces residual stresses that lead to strain hardening, and potentially improvements in fatigue, stress corrosion cracking (SCC) and general corrosion behaviour in many, but not all, corrosive media. In this paper, two specimens made of AISI 304L stainless steel, one LSP-treated and one un-treated, were tested at 280 °C and 8 MPa in VVER (or PWR) primary circuit water chemistry using in situ Electrochemical Impedance Spectroscopy (EIS). This experiment serves to qualify the influence of LSP on the changes in corrosion behaviour in high-temperature, high-density water. The residual stress (RS) measurement of the surface showed a compression RS. Before LSP treatment, RS at the surface was 52.2 MPa in the rolling direction 0°RD and 10.42 MPa in the transverse rolling direction 90°RD. After the treatment, surface RS was −175.27 MPa and −183.51 MPa for Scan and TScan directions, respectively. The effect of compressive RS at the surface was studied and showed an increase in corrosion rate. The analysis of oxide layer by SEM revealed differences between LSP-treated and untreated AISI 304L specimens and their connection to corrosion rates

Dynamics of a cantilever beam with piezoelectric sensor: Parameter identification

This work has been supported by the grant 23-06220S of the Czech Science Foundation within institutional support RVO:61388998

Computation of Invariants of Lie Algebras by Means of Moving Frames

A new purely algebraic algorithm is presented for computation of invariants (generalized Casimir operators) of Lie algebras. It uses the Cartan's method of moving frames and the knowledge of the group of inner automorphisms of each Lie algebra. The algorithm is applied, in particular, to computation of invariants of real low-dimensional Lie algebras. A number of examples are calculated to illustrate its effectiveness and to make a comparison with the same cases in the literature. Bases of invariants of the real solvable Lie algebras up to dimension five, the real six-dimensional nilpotent Lie algebras and the real six-dimensional solvable Lie algebras with four-dimensional nilradicals are newly calculated and listed in tables.Comment: 17 pages, extended versio