Avaliação e cultura de qualidade nos serviços italianos para a infância: orientações e experiências dos anos 1990 aos dias de hoje

Resumo O artigo apresenta o debate sobre a qualidade dos serviços para a infância na Itália a partir dos anos 90 do século passado, no contexto das reflexões e das propostas que surgiram na Europa. Passando a limpo as experiências mais significativas de avaliação de tais contextos no decorrer de 30 anos, serão expostas as orientações prevalentes, seja no nível das políticas educativas, sobretudo regionais, seja no nível do debate pedagógico. A apresentação se concluirá, mostrando quais seriam, atualmente, os desafios surgidos pela necessidade de difundir uma cultura de avaliação que se coloque em prol de promover processos efetivos de melhoria

The structure of ZrO2 phases and devetrification processes in a Ca-Zr-Si-O-based glass ceramic: a combined a-XRD and XAS study

The structure of Zr atomic environment in a CaO-ZrO2-SiO2 glass-ceramic has beenstudied combining x-ray absorption spectroscopy (XAS), X-ray diffraction (XRD) andanomalous-XRD (a-XRD) techniques as a function of thermal treatments. The analysisof XRD patterns demonstrates that the devitrification process, as a function ofthermal treatment, proceeds through the partial segregation of Zr-depleted phases(Wollastonite-like) and Zr-rich phases (Zr-oxides). The XAS and a-XRD measurementsat the Zr K edge have been exploited to get a closer insight on the atomicstructure around Zr ions. In the as quenched glass the Zr is 6-fold coordinated to Oxygenatoms in an amorphous environment rich of Ca and Si. Thermal treatment firstly(T=1000 - 1050 oC) determines the partial segregation of Zr in form of oxide whichcrystalline structure is that of tetragonal Zirconia (t-ZrO2). Raising the temperature(T=1100 oC) provokes the formation of ZrO2 crystallites in the monoclinic crystallographicphase (Baddeleyite: m-ZrO2). The analysis of XAS data demonstrates that aconsiderable amount of Zr still remains in an amorphous Calcium-Silicate phase

Short range investigation of sub-micron zirconia particles

The Perturbed Angular Correlations technique was used to determine the nanoconfigurations and their thermal behavior in two non-aggregated zirconia nanospheres of unlike sizes obtained by adding different water amounts during preparation. Three residues containing- Zr surroundings were determined for the non-crystalline starting zirconias, the two organics containing- ones being particle size dependent. Upon crystallization, the nanospheres showed the stabilization of both tetragonal (t´- and t- forms) and cubic (Xc- form) phases. Nevertheless, their amounts, temperature of appearance and thermal evolution depended on the residues containing- precursors. It was observed, in addition, that the structure of the smaller nanospheres became gradually monoclinic. The bigger spheres remained stabilized up to the highest temperatures certainly due to their lower specific surface area that favors the permanence of the oxygen defective t´- form

Stable population structure in Europe since the Iron Age, despite high mobility

Ancient DNA research in the past decade has revealed that European population structure changed dramatically in the prehistoric period (14,000–3000 years before present, YBP), reflecting the widespread introduction of Neolithic farmer and Bronze Age Steppe ancestries. However, little is known about how population structure changed from the historical period onward (3000 YBP - present). To address this, we collected whole genomes from 204 individuals from Europe and the Mediterranean, many of which are the first historical period genomes from their region (e.g. Armenia and France). We found that most regions show remarkable inter-individual heterogeneity. At least 7% of historical individuals carry ancestry uncommon in the region where they were sampled, some indicating cross-Mediterranean contacts. Despite this high level of mobility, overall population structure across western Eurasia is relatively stable through the historical period up to the present, mirroring geography. We show that, under standard population genetics models with local panmixia, the observed level of dispersal would lead to a collapse of population structure. Persistent population structure thus suggests a lower effective migration rate than indicated by the observed dispersal. We hypothesize that this phenomenon can be explained by extensive transient dispersal arising from drastically improved transportation networks and the Roman Empire’s mobilization of people for trade, labor, and military. This work highlights the utility of ancient DNA in elucidating finer scale human population dynamics in recent history

Avaliação e cultura de qualidade nos serviços italianos para a infância: orientações e experiências dos anos 1990 aos dias de hoje

Resumo O artigo apresenta o debate sobre a qualidade dos serviços para a infância na Itália a partir dos anos 90 do século passado, no contexto das reflexões e das propostas que surgiram na Europa. Passando a limpo as experiências mais significativas de avaliação de tais contextos no decorrer de 30 anos, serão expostas as orientações prevalentes, seja no nível das políticas educativas, sobretudo regionais, seja no nível do debate pedagógico. A apresentação se concluirá, mostrando quais seriam, atualmente, os desafios surgidos pela necessidade de difundir uma cultura de avaliação que se coloque em prol de promover processos efetivos de melhoria

La valutazione di contesto e del bambino: questioni e prospettive

In relazione alla educational evaluation, vengono delineati il rapporto tra valutazione e qualità educativa proponendo approcci diversi in relazione agli scopi, agli oggetti e ai soggetti della valutazione. Viene quindi delineato un approccio valutativo formativo e partecipato, in relazione tanto alla valutazione di contesto che del bambino

The effect of sintering conditions on linear shrinkage in porcelainized stoneware tiles as studied in a two-level full factorial experimental design

Linear firing shrinkage, together with water absorption, apparent density and the modulus of rupture, is commonly used as a process control parameter in industrial ceramics. In this paper its optimization is studied with a two-level full factorial experimental design approach. In particular, the influence of forming pressure, sintering temperature and time have been inves-tigated. It has been verified that a Design of Experiment (DOE) approach is a suitable tool to identify the significantfactors that control the densification process of porcelainized stoneware tiles. Moreover a mathematical model has been proposed and tested with good results. The results evidenced that the variable with the higher influence is the sintering temperature followed by forming pressure while time has influence only in sinergy with temperature

Il metodo Rietveld nello studio della capacit\ue0 deflocculante di tripolifosfati di sodio

In questo articolo la capacit\ue0 deflocculante di diversi tripolifosfati (TTT) \ue8 messa in corralazione con la loro analisi mineralogica e chimic

ESEM investigation of the reaction mechanism in Pr-doped zircon

The formation mechanism of praseodymium-doped zircon stain was studied, using environmental scanning electron microscopy (ESEM) primarily. The significance of ESEM as a processing tool for studying chemical and morphological dynamic changes was evaluated, with respect to the traditional investigation methods. In particular ESEM observation permits to define the role of the mineralizers and indicates a two-step mechanism