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Engineering dynamic systems or materials to respond to biological process is one of the major tasks in synthetic biology and will enable wide promising applications, such as robotics and smart medicine. Herein, a super‐soft and dynamic DNA/dopamine‐grafted‐dextran hydrogel, which shows super‐fast volume‐responsiveness with high sensitivity upon solvents with different polarities and enables creation of electric circuits in response to microbial metabolism is reported. Synergic permanent and dynamic double networks are integrated in this hydrogel. A serials of dynamic hydrogel‐based electric circuits are fabricated: 1) triggered by using water as switch, 2) triggered by using water and petroleum ether as switch pair, 3) a self‐healing electric circuit; 4) remarkably, a microbial metabolism process which produces ethanol triggering electric circuit is achieved successfully. It is envisioned that the work provides a new strategy for the construction of dynamic materials, particularly DNA‐based biomaterials; and the electric circuits will be highly promising in applications, such as soft robotics and intelligent systems., A super‐soft and dynamic DNA‐based hybrid hydrogel is reported, which shows super‐fast volume‐responsiveness with high sensitivity upon solvents with different polarities and enables creation of electric circuits in response to microbial metabolism.

Treballs Finals de Grau de Matemàtiques, Facultat de Matemàtiques, Universitat de Barcelona, Any: 2020, Director: Antoni Benseny, [en] Given an electrical circuit, formed by wires, nodes, batteries and resistors, the main goal of this work is to solve this electrical circuit. This means finding the electric current in each wire. The graph theory and its use in computer science through data structures, like trees, and hierarchical traversing algorithms, like the Breadth-first search algorithm, will be used to solve the problem. The first part of the project will intend to solve an electrical circuit using C++, the main algorithms used have been described in this paper. The second part of the project will simulate an electrical circuit using graphics and control libraries allowing to interact with the electrical circuit.

This paper characterizes the robust second-moment stability of stochastic linear systems subject to varying delays. The delays assume a particular form suitable to represent packet loss in networked control systems, under the zero-order hold feedback. The proposed robust stability condition requires checking the spectral radius of an appropriate matrix that that depends on uncertain parameters belonging to a polytope. Due to this polytope’s dependence, checking the spectral radius is difficult from the numerical viewpoint. As an attempt to solve the problem, we convert the polytope-based condition into a randomized approach. Namely, we present probability bounds that help us certificate the robust second-moment stability under high probability. A real-time electronic application illustrates the potential benefits of our approach.

The development of new academie programs must assure that the goals of the authors are taken into account by the teachers and moreover that they are followed up by pedagogical actions. This paper deals with the analysis of the teachers’ perception of the didactic contents in the basic electricity program developed at the middle school level. Semi-directive interviews performed with nine teachers seem to indicate that the teachers’ professional experience and their usual habits limit their perception of program modifications, despite their knowledge of the existing difficulties that the modifications are supposed to remedy. A discussion about how to help teachers better understand and implement the intentions of the curriculum’s authors concludes the paper., La mise en place de nouveaux programmes nécessite, de la part des enseignants, une prise en compte des intentions des rédacteurs puis une traduction de celles-ci en actes pédagogiques. Nous nous intéressons ici à la perception que les enseignants ont des intentions didactiques contenues dans le nouveau programme d’électricité de la classe de quatrième en France. Des entretiens semi-directifs, conduits avec neuf enseignants, semblent montrer que leur expérience professionnelle, leurs habitudes, limitent leur perception des nouveautés malgré une bonne connaissance des difficultés que les modifications de programme visent à résoudre. Les formes particulières de cet effet de filtrage sont analysées. On observe à ce propos qu’il peut être utile d’associer des intentions didactiques nouvelles à un objet matériel lui-même nouveau qui leur serve de support., El desarrollo de nuevos prog ramas académicos necesita que las intenciones de los redactores sean tomadas en cuenta por los enseñantes y además que ellas sean traducidas en actos pedagógicos. Nosotros nos interesamos aqui en la percepcion que los enseñantes tienen de las intenciones pedagógicas contenidas en el nuevo programa de electricidad de la clase de cuarto en Francia. Entrevistas semi-directivas conducidas con nueve enseñantes, indican que sus experiencias profesionales, sus hábitos, limitan sus percepciones de las novedades a pesar de un buen conocimiento de las dificultades que las modificaciones del programa intentan resolver. Las formas particulares de este efecto de filtro son analizadas. Se observa a este propósito que puede ser útil asociar intenciones didácticas nuevas a un objeto material nuevo que les sirva de soporte., Couchouron Monique, Viennot Laurence, Courdille Jean-Marie. Les habitudes des enseignants et les intentions didactiques des nouveaux programmes d'électricité en classe de quatrième. In: Didaskalia, n°8, 1996. Nouvelles technologies dans l'enseignement des sciences et des techniques. pp. 81-96.

This paper presents web-based graphical schematic editor for analysis of electric and electronic circuits. It is a JavaScript application that uses Spice OPUS and Maple with PraCAn package as a computation engine. In case of linear circuits, results can be obtained in symbolic form. Continuous-time linear and nonlinear circuits as well as periodically switched linear (PSL) circuits can be analyzed. All created circuits can be exported to various file formats for greater compatibility with documentation formats and other simulation programs. The whole system is developed at the Department of Circuit Theory, for teaching support and research.

This paper presents a mixed methods study in which 77 students and 3 teachers took part, that investigated the practice of Learning by Design (LBD). The study is part of a series of studies, funded by the Netherlands Organisation for Scientific Research (NWO), that aims to improve student learning, teaching skills and teacher training. LBD uses the context of design challenges to learn, among other things, science. Previous research showed that this approach to subject integration is quite successful but provides little profit regarding scientific concept learning. Perhaps, when the process of concept learning is better understood, LBD is a suitable method for integration. Through pre- and post-exams we measured, like others, a medium gain in the mastery of scientific concepts. Qualitative data revealed important focus-related issues that impede concept learning. As a result, mainly implicit learning of loose facts and incomplete concepts occurs. More transparency of the learning situation and a stronger focus on underlying concepts should make concept learning more explicit and coherent.

This paper presents a mixed methods study in which 77 students and 3 teachers took part, that investigated the practice of Learning by Design (LBD). The study is part of a series of studies, funded by the Netherlands Organisation for Scientific Research (NWO), that aims to improve student learning, teaching skills and teacher training. LBD uses the context of design challenges to learn, among other things, science. Previous research showed that this approach to subject integration is quite successful but provides little profit regarding scientific concept learning. Perhaps, when the process of concept learning is better understood, LBD is a suitable method for integration. Through pre- and post-exams we measured, like others, a medium gain in the mastery of scientific concepts. Qualitative data revealed important focus-related issues that impede concept learning. As a result, mainly implicit learning of loose facts and incomplete concepts occurs. More transparency of the learning situation and a stronger focus on underlying concepts should make concept learning more explicit and coherent.

International audience; Arduino open-source microcontrollers are well known in sensor applications for scientific equipment and for controlling RepRap 3D printers. Recently low-cost open-source gas metal arc weld (GMAW) RepRap 3D printers have been developed. The entry-level welders used have minimal controls and therefore lack any real-time measurement of welder voltage or current. The preliminary work on process optimization of GMAW 3D printers requires a low-cost sensor and data logger system to measure welder current and voltage. This paper reports on the development of a low-cost open-source power measurement sensor system based on Arduino architecture. The sensor system was designed, built, and tested with two entry-level MIG welders. The full bill of materials and open source designs are provided. Voltage and current were measured while making stepwise adjustments to the manual voltage setting on the welder. Three conditions were tested while welding with steel and aluminum wire on steel substrates to assess the role of electrode material, shield gas, and welding velocity. The results showed that the open source sensor circuit performed as designed and could be constructed for

Neste artigo analisamos diferentes concepçõoes e raciocínios dos alunos sobre conceitos básicos envolvidos em circuitos elétricos simples, que se tornam obstáculos para a aprendizagem, e apresentamos um produto de um trabalho de pesquisa, que consiste em um conjunto de atividades de simulação e modelagem computacionais, desenvolvidas com o software Modellus, levando em conta tais dificuldades, com o objetivo de auxiliar o aluno a superá-las. In this paper we analyze different student's conceptions and reasonings regarding basic concepts involved in simple electric circuits, that become obstacles for the learning, and present a product of a research work, that consists in a set of computational modeling and simulation activities, developed with the software Modellus, taking into account such difficulties to help students to surpass them.

In this paper, the implementation of signal processing circuits on a novel translinear Field-Programmable Analog Array (FPAA) testchip is reported. The FPAA testchip is based on a 0.35-micron, fully CMOS translinear element, which is the core block of a reconfigurable analog cell. The FPAA embeds a 5 5 cell array. As implementation examples, a four-quadrant multiplier with five decade dynamic range and a programmable fourth-order low-pass filter with up to 7 MHz bandwidth have been mapped on the translinear FPAA. 14 cells have been used for the four-quadrant multiplier while 18 cells were needed for the fourth-order low-pass filter.