Young Children’s cliques : a study on processes of peer acceptance and cliques aggregation

A considerable amount of research has examined the link between children’s peer acceptance, which refers to the degree of likability within the peer group, social functioning and emotional wellbeing, at a same age and in a long term perspective, pointing out to the contribution of peer acceptance for mental wellbeing. Our study proposes a sociometric methodology that, differently from many studies focused on individual classifications of social status, moves to the analysis of affiliative social networks within the class group. This study describes how individual factors such as socio-emotional competence, temperament, and linguistic skills are related to positive reciprocated nominations (=RNs) and examines the cliques generated by reciprocal nominations according to similarities (socio-emotional competence, temperament and linguistic skills) among cliques’ members. Eighty-four preschool children (M age = 62.5 months) were recruited. The Sociometric Interview to assess RNs and the Peabody Picture Vocabulary Test - Revised (PPVT-R; Dunn & Dunn, 1981) to assess receptive language were administered; the Social Competence and Behaviour Evaluation Short Form questionnaire (SCBE-30; LaFreniere & Dumas, 1996) and the Quit Temperament Scale (Axia, 2002) were filled in by the teachers. Results showed that children with higher RNs presented higher scores in social orientation, positive emotionality, motor activity, linguistic skills and social competence (trend), and exhibited lower anxietywithdrawal. The analysis of cliques revealed that children preferred playmates with similar features: social competence, anger-aggression (trend), social orientation, positive emotionality, inhibition to novelty, attention, motor activity (trend) and linguistic skills. These findings provide insights about processes of peer affiliation, highlighting the role of socio-emotional functioning and linguistic skills.peer-reviewe

Recycling PC-TV waste glass in clay bricks and roof tiles

Disposal of PC and TV sets is a growing problem, involving for over 40 wt. % waste glasses with high Pb (funnel) or Ba-Sr concentration (panel) which cannot be recycled in the glass manufacture. A possible way to re-use these glasses is in the manufacturing of clay bricks and roof tiles, that was appraised by laboratory simulation of the brickmaking processing and technological characterization of unfired and fired products. The recycling of both funnel and panel glasses into clay bodies is technologically feasible, resulting in a behaviour substantially plasticity-reducing during shaping-drying (implying a reduction of mechanical strength) and promoting sintering during firing. No significant release of Pb, Ba and Sr was found during firing and leaching test for the carbonate-poor body; in contrast, some Pb volatilization during firing and Sr leaching were observed for the carbonate-rich body. Additions of 2 wt. % appear to be practicable, while 5 wt. % glass induces unacceptable modifications of technological properties. The recommended amount is within 2 and 4 wt. %, depending on the characteristics of clay bodies. The main constraint is that glass must have a particle size below the limit of pan mills used in brickmaking (<1 mm)

Titania slag as a ceramic pigment

The phase transformations and colouring mechanisms that occur during the ceramic processing of titania slag were investigated using XRF-EDS, XRD, DRS and laboratory-scale application in glazed and unglazed tiles. The slag transforms to pseudobrookite, undergoing a drastic colour change during firing as a consequence of thermal oxidation with Fe2+ to Fe3+ and Ti3+ to Ti4+ reactions. The intense brown colour imparted by titania slag is stable at both low (up to 1050 degrees C) and high (around 1200?C) temperatures and is suitable for porcelain stoneware tiles. In through-body application, titania slag enables \u27spotting\u27 effects to be achieved

Process of pyroplastic shaping for special-purpose porcelain stoneware tiles

A novel technique to manufacture special-purpose tiles (i.e. trim pieces, steps, skirting boards, etc.) has been recently developed on the basis of a pyroplastic shaping of porcelain stoneware tiles. This innovative process involves a second firing, peaking at temperatures close to those of sintering, whose effect was investigated by comparing industrially-manufactured tiles before and after pyroplastic shaping. Characterization by XRF, XRPD, SEM and standard testing (ISO 10545) put in evidence that pyroplastic bending induced little changes in the water absorption and bulk density values, as in phase composition. Limited variations occurring to closed porosity, mechanical strength and microstructure do not significantly affect the overall technological performance of the special-purpose tiles, which is substantially the same of the original porcelain stoneware tiles. A detailed microstructural characterization was performed for the first time on porcelain stoneware tiles: coarse grains (>10 ?m) represent 10-15% of total volume, while fine-grained crystals, dispersed in the glassy phase, amount from 30% to 65% of the viscous matrix. The pyroplastic behaviour was found to depend in a complex way on such microstructural and compositional features, which deeply affect the effective viscosity of the matrix

Recycling the insoluble residue from titania slag dissolution (tionite) in clay bricks

Tionite is the insoluble residue from the titania slag dissolution process for TiO2 manufacturing. It is a fine grained sludge consisting of rutile, anatase, amorphous phase and bassanite. Chemical composition is TiO2 (ca. 50%), SiO2 (ca. 30%) and minor Al, Ca, Mg, and Fe, plus residual sulfur, implying an acidic pH of waste. Moisture is about 35% of dry weight. The potential of tionite as colouring agent in clay bricks was appraised by admixing (up to 9%) either as-produced or neutralized tionite to four industrial clay bodies. The effect on technological behaviour was assessed by laboratory simulation of the industrial brickmaking process and determining working moisture, drying sensitivity, shrinkage and bending strength, water absorption, bulk density, efflorescence, and colour. The use of tionite is technologically feasible, with little adjustment of industrial cycle, and resulting brick performances depend remarkably on the composition and properties of clay bodies. Carbonate-rich bodies seem to be affected by tionite more during drying than during firing; carbonate-poor bodies range from little changes to consistent worsening of brick performances. No relevant changes of process and product parameters were found up to 3% tionite. Additions over 5% induce significant variations, such as increase of working moisture and water absorption, decrease of bulk density and bending strength. A definite and consistent improvement of this technological behaviour is achieved by using neutralized tionite. The yearly output of tionite could be entirely recycled by approximately four average size brickworks adding about 3% of residue (dry weight

Glass-ceramic frits for porcelain stoneware bodies: effects on sintering, phase composition and technological properties

In the present work, the effects of glass-ceramic frits (10wt%) added to a porcelain stoneware body in replacement of non-plastic raw materials, were evaluated simulating the tile-making process. Each glass-ceramic frit plays its own peculiar effect on the compositional properties and only some precursors behave as real glass ceramic materials. The positive influence of glass-ceramic precursors in promoting the sintering stands out when temperature onset densification and sintering rate are considered: both of them are improved with respect to the reference body. The presence of glass-ceramic frits allows the preserve good technological properties, complying with the latest requirements of the industrials practice

Processing and properties of large-sized ceramic slabs

Large-sized ceramic slabs - with dimensions up to 360x120 cm2 and thickness down to 2 mm - are manufactured through an innovative ceramic process, starting from porcelain stoneware formulations and involving wet ball milling, spray drying, die-less slow-rate pressing, a single stage of fast drying-firing, and finishing (trimming, assembling of ceramic-fiberglass composites). Fired and unfired industrial slabs were selected and characterized from the technological, compositional (XRF, XRD) and microstructural (SEM) viewpoints. Semi-finished products exhibit a remarkable microstructural uniformity and stability in a rather wide window of firing schedules. The phase composition and compact microstructure of fired slabs are very similar to those of porcelain stoneware tiles. The values of water absorption, bulk density, closed porosity, functional performances as well as mechanical and tribological properties conform to the top quality range of porcelain stoneware tiles. However, the large size coupled with low thickness bestow on the slab a certain degree of flexibility, which is emphasized in ceramic-fiberglass composites. These outstanding performances make the large-sized slabs suitable to be used in novel applications: building and construction (new floorings without dismantling the previous paving, ventilated fa?ades, tunnel coverings, insulating panelling), indoor furnitures (table tops, doors), support for photovoltaic ceramic panelsSe han fabricado piezas de gran formato, con dimensiones de hasta 360x120 cm, y menos de 2 mm, de espesor, empleando m?todos innovadores de fabricaci?n, partiendo de composiciones de gres porcel?nico y utilizando, molienda con bolas por v?a h?meda, atomizaci?n, prensado a baja velocidad sin boquilla de extrusi?n, secado y cocci?n r?pido en una sola etapa, y un acabado que incluye la adhesi?n de fibra de vidrio al soporte cer?mico y el rectificado de la pieza final. Se han seleccionado piezas en verde y cocidas, caracteriz?ndolas desde el punto de vista tecnol?gico, composicional (FRZ, DRX) y microestructural (MEB). Los productos semiacabados muestran una destacada uniformidad microestructural y estabilidad dimensional, dentro de un amplio margen de temperaturas de cocci?n. La composici?n de las fases y la compacidad de la microestructura, son muy semejantes a las que presentan las baldosas de gres porcel?nico convencionales. Los valores de la capacidad de absorci?n de agua, densidad aparente, porosidad cerrada, propiedades funcionales as? como las propiedades tribol?gicas y mec?nicas se sit?an en los mejores valores de las piezas de gres porcel?nico. No obstante las grandes dimensiones, unidas al reducido espesor dotan a las piezas de una cierta flexibilidad, que refuerza el empleo de la capa de fibra de vidrio. Estas destacadas propiedades hacen utilizables, a los grandes formatos, en nueva s aplicaciones, construcci?n y edificaci?n (sin desmontar los pavimentos preexistentes, fachadas ventiladas, revestimiento de t?neles, paneles aislantes etc.) muebles ( encimeras y puertas), soporte de paneles fotovoltaico

Nipple Reconstruction Using the “Arrow Flap” Technique: Outcomes and Patients Satisfaction

Introduction: Skin-sparing mastectomy (SSM) entails complete removal of the breast tissue and the nipple and areola complex (NAC) with preservation of as much of the overlying skin as possible. The preservation of the natural skin envelope during SSM improves the aesthetic outcome of immediate breast reconstruction, but the lack of NAC determines that the reconstructed breast remains anatomically incomplete with not always satisfactory final results. For this purpose, the aim of the present study was to investigate and evaluate the impact of nipple reconstruction after skin sparing and skin reducing mastectomy on the patients' perception and intimate life. Materials and method: This was a comparative single-center prospective study that involved 42 patients underwent NAC reconstruction after SSM. A pre- and postoperative quality-of-life and psychological questionnaires Breast-Q questionnaire (Breast Conserving therapy module) were given to all the patients before the surgery and 6 months after. The statistical analysis with chi-square test was performed. Results: After 6 months a prevalence of patients reported to be very satisfied in regard to shape, appearance, naturalness, projection, position and symmetry. The study shows an overall improvement in all the psychological items analyzed with statistically significant difference regarding: "patient's satisfaction," "self-confidence," "appearance of the breast." Conclusion: The authors believe that the NAC reconstruction has useful functional and aesthetic results particularly appreciated by patients who feel demoralized after breast demolition surgery

Describing communication profiles of low-risk preterm and full-term late talkers

Introduction: Late talkers represent a heterogeneous population. We aimed to describe communication profiles of low-risk preterm and full-term late talkers according to their receptive and expressive vocabulary size, considering communicative, linguistic, cognitive, and motor skills, as well as biological and environmental risk factors. Methods: Sixty-eight late talkers (33 born low-risk preterm and 35 full-term) were identified through a language screening at 30 months. Parents filled out the Italian Short Forms of the MacArthur Bates Communicative Development Inventories and the Socio Conversational Skills Rating Scales. Children were assessed with the Picture Naming Game test and the Bayley Scales of Infant and Toddler Development. Results: A two-step cluster analysis identified three distinct profiles among late talkers according to their receptive and expressive vocabulary size. Severe late talkers (25%) showed less frequent use of pointing, limited verbal imitation, receptive vocabulary size, lexical and sentence production, responsiveness and assertiveness, and lower cognitive scores than mild late talkers (40%). Moderate late talkers (35%) showed less frequent verbal imitation, limited lexical and sentence production and lower cognitive scores than mild late talkers. Male gender was significantly more represented in the severe late profile, whereas other biological and environmental factors did not differ among the three profiles. Conclusions: Findings highlighted the relevance of assessing communicative, lexical, grammar, pragmatic, and cognitive skills to describe late talkers’ profiles. A deeper investigation of phonological skills might also contribute to a further understanding of interindividual variability in this population

Technological behavior of porcelain stoneware bodies with Egyptian syenites

The progressive depletion of the main feldspathic flux deposits in the World is forcing the ceramic industry to search for suitable substitutes. The aim of this study is to assess the potential of some feldspar sources in the Egyptian Eastern Desert, particularly syenites from Abu Khruq, in the manufacture of ceramic tiles. Beneficiated samples obtained by laboratory-scale mineral processing were tested into porcelain stoneware batches (from 10% to 30% wt in replacement of feldspars) and compared with a reference body through a laboratory reproduction of the industrial processing. The technological behavior of unfired tiles does not suffer any significant alteration due to the use of syenites. On the other hand, syenite-bearing bodies exhibit some changes in the phase composition and the chemistry of the melt, that turns richer in alkali, especially K2O. The consequently increased sintering rate depends mainly on the viscosity of the liquid phase formed during firing. In conclusion, syenites can be used without technological hindrances to manufacture porcelain stoneware tiles. The firing behavior of syenite-bearing batches can be reasonably adjusted by setting key parameters (eg, the feldspar amount and the Na/K ratio), but the darker color of fired bodies requires to further lower the iron oxide