An evaluation tool for physics applets

Physics applets are well known appealing resources to teach and learn physics, and a large number of them are available on the Internet. Nevertheless, not all of them are of the same quality, because such applets do not fit every specific teaching/learning purpose. The start question was which features should have a physics applet in order that it can be considered a good applet according to our experience as teachers or lecturers. The answer should be based on practical evaluations of applets from the Internet, taking quality evaluation criteria already published into account. In this way, an evaluation tool was developed as a rubric which draws attention to the different aspects of an applet that are relevant for teaching or learning a physics topic, grouping these aspects into five categories. Each category is given a separate scoring based on a preparatory qualitative evaluation of the aforementioned aspects. This evaluation tool has been tested on five physics applets by four secondary-school teachers as experts in first-year students’ background. The results show the suitability degree of each of these applets as resources for different teaching/learning environments, as well as the suitability of the evaluation tool itself. In addition, the evaluation tool simplifies the interchange of information on physics applets among teachers and lecturers.Postprint (author's final draft

Highly efficient electrochemical and chemical hydrogenation of 4-nitrophenol using recyclable narrow mesoporous magnetic CoPt nanowires

Toxic nitro-compounds, such as 4-nitrophenol, are one of the most common wastewater industrial pollutants. Thus, efficient ways to neutralize them are actively pursued. Here novel procedures to degrade this type of compounds based on the use of mesoporous magnetic nanowires are demonstrated. Fully-mesoporous magnetic narrow (25 nm) CoPt nanowires with an extraordinary effective area are grown by ionic liquid-in-water microemulsions in alumina templates. These mesoporous nanowires are shown to be efficient catalysts for the hydrogenation of 4-nitrophenol by electro-catalysis. Additionally, these nanowires also present an exceptional conventional catalytic activity when used in conjunction with NaBH4, particularly when magnetic stirring is utilized. In fact, magnetically actuated mesoporous CoPt nanowires drastically outperform all state-of-the-art 4-nitrophenol catalysts. Additionally, given their magnetic character, these nanowires can be easily recycled and reused. Thus, the outstanding catalytic performance of mesoporous CoPt nanowires makes them excellent candidates for wastewater treatment agents

Crystal structure solution of an elusive polymorph of Dibenzylsquaramide

The crystal structure of the third polymorph of dibenzylsquaramide (Portell, A. et al., 2009), (fig. 1) has been determined from laboratory X-ray powder diffraction data by means of direct space methods using the computing program FOX. (Favre-Nicolin and Černý, 2002) The structure resolution has not been straightforward due to several difficulties on the indexing process and in the space group assignment. The asymmetric unit contains two different conformers, which has implied an additional difficulty during the Rietveld (Rietveld, 1969) refinement. All these issues together with particular structural features of disquaramides are discusse

Mòduls multimèdia com a suport per l'aprenentatge de l'acústica

La finalitat del projecte era elaborar material en forma de mòduls multimèdia disponibles a través de la xarxa, que incloguessin continguts de física (fenòmens oscil·latoris i ondulatoris) relacionats amb l’acústica, com a material de suport a l’aprenentatge en una ALE semipresencial (“Introducció a l’Acústica”) i, de forma parcial, en assignatures troncals de física dels primers cursos d’enginyeria que inclouen els temes esmentats. Els resultats poden veure’s a les pàgines web fruit d’aquest projecte, http://baldufa.upc.edu/arcadi/acustica/temes.htm. Es disposa allí d’un conjunt de mòduls amb itineraris de navegació, amb continguts hipertextuals, animacions Flash, vídeos, mostres de so i eines interactives i d’autoavaluació (problemes i qüestions multiresposta). Ofereixen la possibilitat d’organitzar-los per a diferents contextos educatius, escollint els temes concrets que puguin ser més interessants per a cada context educatiu concret (p.ex. titulació d’E.T.I., especialitat Electrònica o bé Mecànica, etc.)

The Problem of Inconsistency in Reasoning in Engineering Education – A Case Study about the Mental Model of Sound

Every planning of an efficient teaching has the aim of achieving satisfactory learning outcomes. From a constructivistic point of view, it is a commonly accepted fact that such a planning has to take into account the prior ideas that students bring to the class. In order to know them, we carried out a survey about the prior ideas on the nature of sound that our fifteen third-year engineering students had at the begin of an elective subject on acoustics. We used a questionnaire where the students had to express their prior ideas with their own words. Although the students expressed scientifically accepted ideas in about 2/3 of the individual questions on a whole, a cross comparison between each student’s answers for the different scenarios revealed a great number of inconsistencies in the mental model of the nature of sound (wave model): only about 1/3 of our students were consistent in all these scenarios. The inconsistency in their reasoning was still clearer when each student had to apply his/her respective mental model about sound to several properties of sound, in particular the relationship between pitch and distance travelled by sound. We analyse the state of the art in the literature about the issue of students’ consistency, and we consider some proposals suggested in the literature, which we apply in part in our own teaching resources, in order to overcome this inconsistency problem.Postprint (published version

A multimedia-based course to learn basic acoustics through the Internet: description and evaluation

A course on Basic Acoustics has been implemented as an Internet site with multimedia resources such as Flash animations, video clips, etc. Multimedia resources are particularly suitable for acoustics, due to the special role played by sound. The constructivistic model of learning within the EHEA framework was taken as the most suitable approach. The students’ overall evaluation has been positive, especially as regards the embedded multimedia resources. Furthermore, many comments taken from their evaluations and assignments have helped to correct deficiencies and to improve the course.Postprint (published version

An evaluation tool for physics applets

Physics applets are well known appealing resources for teaching and learning physics, and there is a lot of them available on the Internet. Nevertheless, not all of them are of the same quality as such resources nor fit every specific teaching/learning purpose. The start question was why we teachers or lecturers like a given applet or not, and the answer should be based on practical evaluations of applets from the Internet, taking quality evaluation criteria already published into account. In this way, an evaluation tool was developed as a rubric which draws attention to the different aspects of an applet that are relevant for teaching or learning a physics topic, grouped into five categories. Each category is given a separate scoring based on a preparatory qualitative evaluation of the aforementioned aspects. This evaluation tool has been tested on five physics applets by four secondary-school teachers as experts in first-year students’ background. The results show the suitability degree of each of these applets as resources for different teaching/learning environments, as well as the suitability of the evaluation tool itself, which simplifies the interchange of information on physics applets among teachers and lecturer

Transformació d’uns apunts tradicionals en un web hipertextual d’acústica

Peer Reviewe

Influence of the Nature of Aminoalcohol on ZnO Films Formed by Sol-Gel Methods

Here we present comparative studies of: (i) the formation of ZnO thin films via the sol-gel method using zinc acetate dihydrate (ZAD), 2-methoxyethanol (ME) as solvent, and the aminoalcohols (AA): ethanolamine, (S)-(+)-2-amino-1-propanol, (S)-(+)-2-amino-3-methyl-1-butanol, 2-aminophenol, and aminobenzyl alcohol, and (ii) elemental analyses, infrared spectroscopy, X-ray diffraction, scanning electron microscopy, absorption and emission spectra of films obtained after deposition by drop coating on glass surface, and thermal treatments at 300, 400, 500 and 600 ◦C. The results obtained provide conclusive evidences of the influence of the AA used (aliphatic vs. aromatic) on the ink stability (prior to deposition), and on the composition, structures, morphologies, and properties of films after calcination, in particular, those due to the different substituents, H, Me, or iPr, and to the presence or the absence of a -CH2- unit. Aliphatic films, more stable and purer than aromatic ones, contained the ZnO wurtzite form for all annealing temperatures, while the cubic sphalerite (zinc-blende) form was also detected after using aromatic AAs. Films having frayed fibers or quartered layers or uniform yarns evolved to 'neuron-like' patterns. UV and photoluminescence studies revealed that these AAs also affect the optical band gap, the structural defects, and photo-optical properties of the films

Expanding the Crystal Form Landscape of the Antiviral Drug Adefovir Dipivoxil

The solid state of adefovir dipivoxil (AD) has been revisited. In the present article we extend the knowledge about the solid state of this pharmaceutical prodrug. The stability landscape of the amorphous form with respect to the anhydrous and hydrate crystalline forms has been studied, and the use of an antiplasticizing agent to increase its Tg is described. The crystal structure of the elusive anhydrous form I has been determined from laboratory powder X-ray diffraction data by means of direct space methods using the computing program FOX. In addition, three new isostructural solvates of AD (methanol, ethylenglycol, and methylethylketone) have been discovered and structurally characterized by single cristal X-ray diffraction