1,721,097 research outputs found
The effect of microstructure on the tensile and impact behaviour of short-glass fibre-reinforced polyamide 6.6 as assessed by micro-computed tomography
Full text linkInjection moulding of short-fibre-reinforced thermoplastics opens a new dimension in the field of mass production of complicated net-shaped parts with accurate dimensions and the new challenge is to produce parts with tailored properties. However, the layered structure frequently observed in these composites strongly affects their mechanical behaviour and constitutes the main difficulty in transferring the results of tests performed on standard specimens to actual components and parts. In addition, to use injection-moulded composite materials safely, their mechanical behaviour under different loading conditions must be well understood. In the present work, the effect of microstructure, in terms of fibre length and orientation, on the tensile and impact behaviour of injection-moulded short-glass fibre-reinforced polyamide 6.6 was investigated. Digital reconstruction of the three-dimensional structure of samples, differently oriented with respect to the melt flow path, was obtained by the high-spatial-resolution non-destructive technique of synchrotron radiation micro-computed tomography (micro-CT). Automatic evaluation of the fibre length distribution was developed by a global method based on the mean fibre length distribution, computed from the star length distribution (SLD). The results of uniaxial tensile tests and Izod impact experiments were successfully correlated with morphological analysis of fractured surfaces and the results of SLD. These studies revealed important changes in fibre orientation distribution when the sample orientation is changed with respect to melt flow direction, which also strongly influenced the composite mechanical response.Fil: Rosic, N.. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Mollo, M.. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Bernal, Celina Raquel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnología en Polímeros y Nanotecnología. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnología en Polímeros y Nanotecnología; ArgentinaFil: Cosmi, F.. Università degli Studi di Trieste; Itali
Studio sperimentale sull'apprendimento motorio in relazione al disturbo di alcune variabili esterne
Full text linkLo studio sperimentale condotto è nato dall’esigenza di personalizzare e adattare l’esercizio allenante al singolo o a ristretti gruppi di persone.
La sua finalità scientifica è quella di indagare gli effetti prodotti da uno stimolo multisensoriale traumatizzante di bassa entità sulla memoria emozionale e sul sistema motorio.
L’esigenza di dimostrare scientificamente le conseguenze di un trauma sul movimento e sulla postura nasce dall’esperienza clinica, osservando soggetti realmente traumatizzati e l’augurio migliore per il futuro è quello di riuscire a creare dei protocolli di allenamento adattato per consentire il miglioramento delle strategie posturali e quindi il recupero delle attività motorie progressivamente condizionate da esperienze negative vissute.
Questo lavoro, svoltosi presso il reparto di Medicina Fisica e Riabilitativa del Policlinico Tor Vergata, vede unite diverse figure professionali come il fisiatra, il fisioterapista e il laureato in scienze motorie.
L’obiettivo specifico è quello di valutare se la stimolazione multisensoriale riprodotta in laboratorio (esperienza spiacevole o simulazione di trauma in multisensorialità) causi un indebolimento degli arti inferiori ed in particolare dell’arto destro, ossia la parte di maggiore entrata dello stimolo sensoriale.
Un altro obiettivo specifico è quello di valutare se la stimolazione multisensoriale riprodotta in laboratorio, finalizzata alla rievocazione del trauma vissuto, sia in grado di scatenare meccanismi anticipatori di allerta.
Il campione osservato ai fini di tale studio è composto da 46 persone di età compresa tra i 20 e i 40 anni; sono esclusi coloro che in passato hanno subito traumi cranici.
Il campione è suddiviso in due gruppi:
il Gruppo Sperimentale è disturbato da una simulazione di trauma in multisensorialità durante un’esercitazione di forza massima ed è sottoposto a Re-Test 24 ore dopo;
il Gruppo di Controllo esegue un esercizio di forza massima ed è sottoposto a Re-Test 24 ore dopo.
La valutazione della forza massima è data da un guanto dinamometrico contro il quale i soggetti effettuano una pressione per entrambi gli arti, l’esercizio è quindi in contrazione isometrica contro resistenza.
I risultati ottenuti dall’analisi dei dati sono significativi infatti, nei soggetti appartenenti al Gruppo Sperimentale la resistenza dei muscoli flessori dell’anca destra (in particolare l’ileopsoas) è risultata inferiore rispetto al rilevamento iniziale e rimane tale il giorno dopo quando il soggetto è testato nuovamente nelle stesse condizioni.The experimental study conducted was born from the need to customize and adapt the exercise workout to the individual or small groups of people.
Its scientific aim is to investigate the effects of a multisensory stimulus traumatic low amount of memory and the emotional motor system.
The need to scientifically prove the effects of trauma on the movement and posture comes from clinical experience, watching actors really traumatized the wish the best for the future is to be able to create customized training protocols to enable the improvement of strategies postural and then the recovery of motor activity progressively influenced by negative experiences lived.
This work was held at the Department of Physical Medicine and Rehabilitation Medicine of the Policlinico Tor Vergata, seen together several professionals such as physiotherapist, physiotherapist and a graduate in physical sciences.
The specific objective is to assess whether the multisensory stimulation reproduced in the laboratory (unpleasant experience or trauma in multisensory simulation) causes a weakening of the lower limbs and right limb in particular, that the greater part of the incoming sensory stimulus.
Another specific objective is to assess whether the multisensory stimulation reproduced in the laboratory, aimed at re-enactment of trauma, is able to trigger anticipatory warning mechanisms.
Observed the sample for this study consists of 46 people aged between 20 and 40 years, but excluding those who have suffered head injuries in the past.
The sample is divided into two groups:
The experimental group is disturbed by a simulated trauma during multisensory exercise maximum force and is subject to re-test after 24 hours;
the control group performs an exercise in full force and subject to re-test 24 hours later.
The assessment of maximum force is given by a glove dynamometer against which subjects perform a pressure to both legs, the exercise is therefore isometric contraction against resistance.
The results obtained from the data are significant because, in subjects belonging to the Experimental Group to the strength of the right hip flexors (iliopsoas in particular) was lower than the initial detection and remains the next day when the subject is tested again under the same conditions
Images de la culture, P. H. Chombart de Lauwe, M. J. Chombart de Lauwe, S. Mollo, M. Huguet, et al. 1966.
No full textDufrasne Claude. Images de la culture, P. H. Chombart de Lauwe, M. J. Chombart de Lauwe, S. Mollo, M. Huguet, et al. 1966.. In: Revue française de pédagogie, volume 1, 1967. pp. 40-41
Prediction of the Occurrence of Lameness in Dairy Cows using a Fuzzy-Logic Based Expert System. - Part I
Full text linkRosana G. Moreira, Editor-in-Chief; Texas A&M UniversityThis is a paper from International Commission of Agricultural Engineering (CIGR, Commission Internationale du Genie Rural) E-Journal Volume 7 (2005): Prediction of the Occurrence of Lameness in Dairy Cows using a Fuzzy-Logic Based Expert System. ? Part I by Carvalho, V., I. A. Naas, Mollo, M., and V. Massafera Jr
P. H. Chombart de Lauwe, M. J. Chombart de Lauwe, S. Mollo, M. Huguet, R. Kaès, J. Larrue, C. Thomas, Images de la culture, 1966
No full textVidal Daniel. P. H. Chombart de Lauwe, M. J. Chombart de Lauwe, S. Mollo, M. Huguet, R. Kaès, J. Larrue, C. Thomas, Images de la culture, 1966. In: Sociologie du travail, 10ᵉ année n°4, Octobre-décembre 1968. pp. 454-455
P. H. Chombart de Lauwe, M. J. Chombart de Lauwe, S. Mollo, M. Huguet, R. Kaès, J. Larrue, C. Thomas, Images de la culture, 1966
No full textVidal Daniel. P. H. Chombart de Lauwe, M. J. Chombart de Lauwe, S. Mollo, M. Huguet, R. Kaès, J. Larrue, C. Thomas, Images de la culture, 1966. In: Sociologie du travail, 10ᵉ année n°4, Octobre-décembre 1968. pp. 454-455
RICERCA-AZIONE SUL SIGNIFICATO DELL’ESPERIENZA EDUCATIVA NELLA SCUOLA PRIMARIA E DELL’INFANZIA
No full textManipolazione di un linguaggio socialmente costruito in una classe di scuola primaria: costruzione del concetto di equivalenza
No full textLes objets en tant que médiateurs de la communication chez les enfants atteints de troubles du spectre autistique.
No full textCes dernières années, la perspective socio-matérielle a alimenté un important débat
interdisciplinaire concernant le rôle du monde physique (c.-à-d. les objets) dans le développement
psychologique humain. Plusieurs études dans le domaine de la psychologie du développement ont
montré des résultats positifs dans l'explication de la relation entre le sujet et le contexte social par
une approche socio-matérielle, en particulier au début du développement. L'importance des objets a
également été reconnue chez les enfants atteints de troubles du spectre autistique (TSA), montrant
que ces enfants sont caractérisés par des altérations de l'utilisation des objets dès le début du
développement. Certaines études ont souligné que les objets pouvaient faciliter les interactions entre
les enfants atteints de TSA et leurs pairs. Cependant, le rôle des objets n'a pas été suffisamment
étudié dans les interactions entre les enfants atteints de TSA et les adultes. L'objectif principal de la
présente étude était d'examiner chez les enfants atteints de TSA la fonction communicative que les
activités avec des objets jouent dans les interactions avec les adultes, en mettant en évidence le rôle
médiateur des objets dans ces interactions. Plus généralement, cette étude vise également à
souligner la pertinence d'adopter une perspective socio-matérielle pour mettre en évidence certains
aspects négligés de l'activité psychologique des enfants atteints de TSA. Pour vérifier cette
hypothèse, nous avons mené une étude exploratoire approfondie, en recueillant des données auprès
d'un échantillon d'enfants de trois ans (N = 18 ; F = 3) et de quatre ans (N = 26 ; F = 3) atteints de
TSA. Les enfants ont été observés en situation de jeu libre avec un adulte. Ils étaient libres de
choisir un objet parmi un ensemble prédéfini. Par le biais de données quantitatives, nous avons
décrit les caractéristiques générales de la manipulation d'objets ; par le biais de données qualitatives,
nous avons cherché à saisir et à décrire, dans des séquences microgénétiques, certaines
caractéristiques des activités des enfants, définies comme socio-matérielles. L'analyse des activités
socio-matérielles a suggéré le rôle des objets comme médiateur des interactions entre les enfants
atteints de TSA et les adultes
Epidermal cell junctions and their regulation by p63 in health and disease
No full textAs the outermost tissue of the body, the epidermis is the first physical barrier for any pressure, stress or trauma. Several specialized cell–matrix and cell–cell adhesion structures, together with an intracellular network of dedicated intermediate filaments, are required to confer critical resilience to mechanical stress. The transcription factor p63 is a master regulator of gene expression in the epidermis and in other stratified epithelia. It has been extensively demonstrated that p63 positively controls a large number of tissue-specific genes, including those encoding a large fraction of tissue-restricted cell adhesion molecules. Consistent with p63 functions in cell adhesion and in epidermal differentiation, heterozygous mutations clustered mainly in the p63 C-terminus are causative of AEC syndrome, an autosomal dominant disorder characterized by cleft palate, ankyloblepharon and ectodermal dysplasia associated with severe skin erosions, bleeding and infections. The molecular basis of skin erosions in AEC patients is not fully understood, although defects in desmosomes and in other cell junctions are likely to be involved. Here, we provide an extensive review of the different epidermal cell junctions that cooperate to withstand mechanical stress and on the mechanisms by which p63 regulates gene expression of their components in healthy skin and in AEC syndrome. Collectively, advancement in understanding the molecular mechanisms by which epidermal cell junctions precisely exert their functions and how p63 orchestrates their coordinated expression, will ultimately lead to insight into developing future strategies for the treatment of AEC syndrome and more in generally for diseases that share an overlapping phenotype
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