Teaching programming for secondary school : a pedagogical content knowledge based approach

The general research aim of this thesis is to understand what the PCK of CS for secondary school is, with a special focus on the subject "programming", being programming one of the core subjects of CS. Knowledge of PCK will then be used to assess the Dutch situation, with special focus on Dutch CS textbooks and Dutch teachers. The final aim is to find tailor made solutions for the Dutch CS scenario, where CS risks to disappear from the secondary school curriculum due to several problems. Among the problems evidenced: most Dutch teachers have no solid disciplinary background, being mostly teachers from other disciplines re-trained to teach CS. To support these teachers ad hoc solution, it is necessary to understand the PCK of CS. To do so a preparatory literature study reveals to what extent the PCK of programming has been explored. Because no real effort to portray such knowledge has been done in CS before, an exploratory study has been designed and conducted with expert CS teachers in order to unveil this knowledge. With the knowledge about PCK gathered through this exploratory study, the PCK of textbooks and teachers in the Dutch scenario is evaluated

Selection of novel geopolymeric mortars for sustainable construction applications using fuzzy topsis approach

Construction is recognized as one of the most polluting and energy consuming industries worldwide, especially in developing countries. Therefore, Research and Development (R&D) of novel manufacturing technologies and green construction materials is becoming extremely compelling. This study aims at evaluating the reuse of various wastes, originated in the Kraft pulp-paper industry, as raw materials in the manufacture of novel geopolymeric (GP) mortars whose properties fundamentally depend on the target application (e.g., insulating panel, partition wall, structural element, furnishing, etc.). Five different wastes were reused as filler: Two typologies of Biomass Fly Ash, calcareous sludge, grits, and dregs. The produced samples were characterized and a multi criteria analysis, able to take into account not only the engineering properties, but also the environmental and economic aspects, has been implemented. The criteria weights were evaluated using the Delphi methodology. The fuzzy Topsis approach has been used to consider the intrinsic uncertainty related to unconventional materials, as the produced GP-mortars. The computational analysis showed that adding the considered industrial wastes as filler is strongly recommended to improve the performance of materials intended for structural applications in construction. The results revealed that the formulations containing 5 wt.% of calcareous sludge, grits, and dregs and the one containing 7.5 wt.% of calcareous sludge, grits, dregs, and Biomass Fly Ash-1 have emerged as the best alternatives. Furthermore, it resulted that the Biomass Fly Ash-2 negatively influences the structural performance and relative rank of the material. Finally, this case study clearly shows that the fuzzy Topsis multi-criteria analysis represents a valuable and easy tool to investigate construction materials (either traditional and unconventional) when an intrinsic uncertainty is related to the measurement of the quantitative and qualitative characteristics

La Camera dello Scirocco di Villa Naselli di Gela a Palermo

L'articolo tratta il complesso della Camera (o Stanza) dello Scirocco di Villa Naselli Ambleri a Palermo, una delle poche superstiti e meglio conservate dell'agro palermitano. Tipologicamente, una Stanza dello Scirocco è una struttura sotterranea artificiale, costruita in prossimità di una sorgente d'acqua per riprodurre le piacevoli condizioni di frescura che si possono avvertire in una caverna naturale. I manoscritti e i documenti d'archivio riportano che, in questi luoghi, i nobili amavano trascorrere del tempo in compagnia di parenti ed amici per sfuggire alla calura estiva, banchettando e rinfrescandosi nell'acqua fresca. Dopo aver inquadrato la borgata della Grazia (oggi Villagrazia), dove il complesso ricade, il contributo descrive l'evoluzione storico-costruttiva della Camera, soffermandosi su materiali e tecniche costruttive impiegate nonché i criteri di raffrescamento passivo che, attivati principalmente da una torre del vento di epoca medievale, permettono alla Camera di Ambleri di attivare una costante circolazione d'aria (un unicum nel panorama del tipo) e mantenere, quindi, un micro-clima particolarmente piacevole

Time-frequency analysis of power signal : application to substation monitoring and management system

This paper presents a power disturbance detection and classification method based on Time-Frequency analysis. We will discuss how the choice the kernels affect the characteristic of the distribution function. Here we consider a non-stationary testing harmonic composed of a fundamental frequency of 50Hz and its second and third harmonic frequency components. The 50Hz signal is on for the entire record extending from 0 to 1second, while the 100Hz signal is from 100ms to 350 ms and 200Hz signal is from 200ms to 550ms. As for comparison, we will use the same testing signal for different type of kernels. This technique has been applied in a substation monitoring and management system which monitors the power quality at the substation as well as the street lighting panel

Teaching programming for secondary school : a pedagogical content knowledge based approach

The general research aim of this thesis is to understand what the PCK of CS for secondary school is, with a special focus on the subject "programming", being programming one of the core subjects of CS. Knowledge of PCK will then be used to assess the Dutch situation, with special focus on Dutch CS textbooks and Dutch teachers. The final aim is to find tailor made solutions for the Dutch CS scenario, where CS risks to disappear from the secondary school curriculum due to several problems. Among the problems evidenced: most Dutch teachers have no solid disciplinary background, being mostly teachers from other disciplines re-trained to teach CS. To support these teachers ad hoc solution, it is necessary to understand the PCK of CS. To do so a preparatory literature study reveals to what extent the PCK of programming has been explored. Because no real effort to portray such knowledge has been done in CS before, an exploratory study has been designed and conducted with expert CS teachers in order to unveil this knowledge. With the knowledge about PCK gathered through this exploratory study, the PCK of textbooks and teachers in the Dutch scenario is evaluated

Constructive characters of the Western Sicilian masonry in the XVIII and XIX centuries

La tradizione costruttiva di apparecchi murari nella Sicilia occidentale - soprattutto a causa dei frequenti terremoti che si verificarono a Palermo tra i secoli XVIII-XIX (il pi\uf9 distruttivo avvenuto nel 1726, seguito da quelli del 1751, e 1823) - impose la realizzazione di nuovi tipi di muratura che, nel rispetto dei precetti della regola dell'arte, suggeriscono metodi pi\uf9 severi di quella che si pu\uf2 definire la "buona" costruzione muraria, sia nella scelta dei materiali che nell'adozione di nuove tecniche costruttive. La cultura tecnica di quel tempo era in grado di definire metodi costruttivi, introducendo appropriati miglioramenti e sperimentazioni, che promossero nuove conoscenze, tecniche di consolidamento, anche antisismiche, sia tramite l'introduzione di nuovi materiali che nell'identificazione -caso per caso -della muratura pi\uf9 appropriata. Ne deriva un compendio di tecniche che risolsero brillantemente i problemi relativi al rischio sismico e favorirono l'interazione tra la muratura, a seconda del tipo, e gli altri sistemi strutturali (solai, volte, sistemi di copertura, aggetti, controsoffitti, ecc) inseriti e/o intimamente collegati ad essa. Lo scopo di questo studio \ue8 quello di analizzare le pratiche costruttive consolidate - anche attraverso nuove acquisizioni documentarie - e di trattare nello specifico alcuni casi di studio, che identificano notevoli "exampla" per la loro originalit\ue0 e la sperimentazione delle soluzioni finali adottate. Allo stesso tempo, si vuole produrre un atlante delle tecniche costruttive tradizionali che pu\uf2 rilevarsi estremamente utile per gli studiosi che indagano nel campo della costruzione storica, nonch\ue9 per i tecnici e gli operatori che agiscono nel campo del restauro e del consolidamento strutturale, indirizzandoli verso un progetto rispettoso e compatibile. Inoltre, attraverso un confronto con le regole di costruzione evidenziate da trattati e manuali, si vogliono mettere in luce le tecniche costruttive della tradizione siciliana, al fine di segnalarle ad un ambito tecnico pi\uf9 ampio, evidenziando anche le caratteristiche e gli elementi di specifici originalit\ue0 che si sono riscontrati durante la ricerca.The tradition of weight-bearing walls in the Western Sicily - mainly due to the frequent earthquakes occurring in Palermo between the XVIII-XIX centuries (the most destructive happened in 1726, 1751, and 1823) - imposed new types of masonry that, following the precepts of the rule of the art, suggested more stringent methods of well-construction, both in the choice of materials and in the adoption of novel constructive technologies. The technical culture of that time was able to refile the constructive methods introducing appropriate improvements and experiments, which promoted the development of new knowledge (matter, materials, and constructive techniques), systems of consolidation and anti-seismic techniques, both for the introduction of new materials and in the identification of the most appropriate masonry. The result is a compendium of noteworthy techniques that brilliantly solved the problems related to the seismic risk as well as helped the interaction between masonry, depending on types, and the other structural and not structural systems (floors, vaults, roofs, overhangs, ceilings, etc.) connected to it. The aim of this work is analyzing the consolidated construction practices \u2013 also through new documentary acquisitions \u2013 and discussing some cases of study, that identify some notable exampla for the originality and the experimentation of the final adopted solutions. At the same time, we want to produce an atlas of traditional constructive techniques that may be extremely useful to scholars investigating the field of historical construction as well as to technicians and contractors working in restoration and structural reinforcements towards a respectful and compatible project. Moreover, in comparison to the knowledge of construction rules handed by treaties and manuals, we want to transmit the building techniques of the Sicilian tradition, in order to properly report them in respect to a wider technical ambit, emphasizing also the specific characteristics and elements of originality that we have founded during our researches

Timber framed with masonry infill: a historical anti-seismic device. The Portuguese Pombaline gaiola.

La ricostruzione postsismica e la prevenzione sismica sono stati da sempre un fondamento costruttivo.Questo studio analizza la tipologia costruttiva della gaiola pombalina, un sitema costruttivo e strutturale molto diffuso in Portogallo ma non solo, adottato a Lisbona a seguito del terremoto del 1755. Si analizzano i materiali e le tecniche costruttive, gli elementi utili al rinforzo e consolidamento della struttura muraria, ampiamente diffuso in area mediterranea a partire dal XVIII secolo.Questo sistema costruttivo pu\uf2 e deve anche oggi essere considerato un utile presidio antisismico da riconoscere e preservare da interventi incolti, se non addirittura da incongrue demolizioni.Post-seismic reconstruction and seismic prevention have always been a major concern worldwide. This work analyses the Pombaline gaiola (meaning cage), a structural system of masonry reinforcement used in the reconstruction of Lisbon following the earthquake of 1755. A gaiola consists in the insertion of a three-dimensional timber frame embedded in stone masonry in order to bind together the various structural parts, and contribute to the overall seismic resistance. Timber framed reinforcement is an old anti-seismic device that may be globally observed in the history of the constructive technology. From the Roman times, this system spread in the Mediterranean area during the XVIII century but a large quantity of examples can be observed almost worldwide. The Pombaline gaiola is analysed from an architectural, constructive, and structural point of view to show how that traditional system made a robust (re)construction possible. Beyond the suboptimal rules of the art and tacit historical instances, and by means of philological criterion and detailed analysis of seismic improvement, contemporary preservation works should ensure the structural safety of the historical construction. In such a perspective, this study examines aspects of diffused timber frameworks with masonry infill that go beyond the anti-seismic technology and develops guidelines for preservation