247 research outputs found
Les fiches de sortie hopitalieres comme source d'information de l'enregistrement. XI Reunion du groupe pour l'épidémiologie et l'enregistrement du cancer dans les pays de langue latine
No full textMultiscale relaxation in aging colloidal gels: From localized plastic events to system-spanning quakes
No full textRelaxation of internal stresses through a cascade of microscopic restructuring events is the hallmark of many materials, ranging from amorphous solids like glasses and gels to geological structures subjected to a persistent external load. By means of photon correlation imaging, a recently developed technique that blends the powers of scattering and imaging, we provide a spatially and temporally resolved survey of the restructuring and aging processes that spontaneously occur in physical gels originating from an arrested phase separation. We show that the temporal dynamics is characterized by an intermittent sequence of spatially localized "microquakes" that eventually lead to global rearrangements occurring at a rate that scales with the gel age. Notably, these dramatic upheavals of the gel structure are heralded by a progressive acceleration of the microscopic gel dynamics that originates from recognizable active spots and then spreads at a large but finite speed through the gel. Within the "slack" phase between two of these "macroquakes," the fluctuations of the degree of temporal correlation obey a non-Gaussian statistics described by a generalized logistic distribution. The evidence we obtained bear consistent analogies with the stress relaxation processes taking place in earthquake sequences and with the intermittent restructuring of plastic crystals at the microscale
Diffusione nell'ambiente, effetti tossici e cancerogeni del cromo
No full texteffetti tossici e cancerogeni del crom
Analyzing difficulties in arithmetic word problem solving: An epistemological case study in primary school
No full textThis paper focuses on difficulties that primary school students have in facing mathematical word problems. In particular, we are interested in exploring how they develop in the transition from grade 2 to grade 5. The research basis of the hypothesis is that some difficulties detected in grade 5 are already predictable in grade 2. Starting from the data collected in grade 5 by the National Standardized Assessment, we carry out a quantitative analysis looking for word problems in which students experience difficulties. Subsequently, we conduct a backward analysis of the grade 2 test of the same cohort of students in order to identify a set of word problems linked with those selected in grade 5 test. The analysis shows the presence of many common difficulties in the two grades. We design and carry out specific educational activities concerning word problem-solving in grade 2. These activities produce positive changes in the experimental class compared to the control class. This could suggest that a previous intervention in grade 2 could allow overcoming future difficulties in word problem text comprehension in grade 5
Analisi dei dati di mortalità per cancro (periodo 1984-87) nei residenti genovesi immigrati da altre regioni
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Una review sulla associazione silice-cancro del polmone (uso e abuso del PMR negli studi basati su autopsia).
No full textSul controllo di qualità dei distaccanti, ausiliari per prodotti da forno
No full textGli Autori evidenziano l’importanza dell’attività del controllo qualità nella produzione degli agenti distaccanti da impiegare nell’industria dei prodotti da forno. A questo proposito risulta importante la verifica di qualità della frazione grassa utilizzata come componente fondamentale e veicolante altre materie prime e/o additivi, e vengono riportati dati di composizione in trigliceridi di oli impiegati in formulazione di alcuni distaccanti in commercio sul mercato nazionale.
Nello stesso tempo si dimostra evidente il fenomeno di migrazione del distaccante dal contenitore di
cottura al prodotto da forno cotto: ciò suggerisce considerazioni utili in merito all’uso di alcuni componenti ausiliari impiegati in formulazione. Con tale nota si auspica una più chiara regolamentazione dell’uso di alcuni additivi oltre ad una sempre maggiore attenzione per la razionale scelta delle materie prime impiegate, sia ai fini della costanza di efficienza che ai fini della qualità e sicurezza degli alimenti
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