Recent advances in bio-based polymers and composites: Preface to the BiPoCo 2012 Special Section

The increasing environmental awareness of the society has become an important factor in recent decades affecting legislation, commerce and industry as well as research and development to a great extent [1-7]. This tendency has also been recognized by the European Community, which supports numerous projects in order to promote innovative solutions leading to a sustainable economy. Three such projects of the Seventh Framework Programme with overlapping scopes, Biostruct [8], Forbioplast [9] and Woody [10], focused on the valorization of forest-derived resources for the production of various bio-based products, including polymers, additives, and composites with natural reinforcements. The leaders of these projects decided to join forces to organize a conference in order to create a possibility to disseminate their results as well as to increase the efficiency of their research and development by exchanging ideas with leading experts in the field. The International Conference on Bio-based Polymers and Composites (BiPoCo 2012) was organized for the first time in Siófok, Hungary, between May 27th and 31th, 2012, with 234 registered participants delivering more than 90 oral and 110 poster presentations. Scientific and technological lectures focused on the theory and practice of biopolymers, renewable-based monomers, fillers and additives as well as sustainable polymer blends and composites with possible application in packaging, agriculture, automotive or biomedicine. In the following sections we provide a short overview of the main research areas and presentations related to the event, and by doing so, continue the line set by Filip Du Prez, Jean-Marie Raquez and Philippe Dubois as Editors of the recent Biobased Polymers and Related Materials special issue of the European Polymer Journal [11]. Below we introduce to the reader the BiPoCo 2012 Special Section containing four feature articles and several research papers

Interactions, structure and properties in poly(lactic acid)/thermoplastic polymer blends

Blends were prepared from poly(lactic acid) (PLA) and three thermoplastics, polystyrene (PS), polycarbonate (PC) and poly(methyl methacrylate) (PMMA). Rheological and mechanical properties, structure and component interactions were determined by various methods. The results showed that the structure and properties of the blends cover a relatively wide range. All three blends have heterogeneous structure, but the size of the dispersed particles differs by an order of magnitude indicating dissimilar interactions for the corresponding pairs. Properties change accordingly, the blend containing the smallest dispersed particles has the largest tensile strength, while PLA/PS blends with the coarsest structure have the smallest. The latter blends are also very brittle. Component interactions were estimated by four different methods, the determination of the size of the dispersed particles, the calculation of the Flory-Huggins interaction parameter from solvent absorption, from solubility parameters, and by the quantitative evaluation of the composition dependence of tensile strength. All approaches led to the same result indicating strong interaction for the PLA/PMMA pair and weak for PLA and PS. A general correlation was established between interactions and the mechanical properties of the blends

Vizuális médiahatások és a testi elégedettség kapcsolata

Problem : Mass media is the essential source of distributing the cultural expectations about body appearance. In western societies the emphasized and idealized lean and skinny female bodies are hardly attainable for the majority of population. Percieving the difference between the actual and the idealized bodies can cause serious dissatisfaction, frustration or anxiety about the physical appearance. Nowadays women’s bodies appearing in movies and television are drastically thinner like thirty years ago, and dieting is a popular and recurrent issue of different television programmes and articles of female magazines. Aim: The aim of this presentation is to reveal the relationship between the percieved media images and the effect of body dissatisfaction. Relevant studies show great direct effect of skinny images on body dissatisfaction and percieved anxiety. Results: Repeated presentation of thin images are associated with the internalization of the thin ideal. Some personal characteristics such as overweight, body dissatisfaction, frequent self-monitoring or the neccesity to compare the physical appearance to the others, are associated with the vulnerability of body dissatisfaction as a result of viewing thin media images. Conclusion: Many researchers emphasize the association of thin media images with body dissatisfaction, body image disturbances and eating disorders. Body image and psychological well-being shows close connection, as body image shows great effect on self-evaluation and behaviour. In some serious conditions body image disturbances are associated with eating disorders, depression, social phobia, or other self-harm behaviours

A tanárképzés történeti hagyományai Magyarországon

The “teacher training centre” named in the 2011 Higher Education Act is not a novelty in the history of the Hungarian secondary school teacher training. Regarding its function, “the teacher training institute” established at the end of the 19th century can be considered as an antecedent at Hungarian universities. This type of institution was created in university cities, such as Budapest, and later Kolozsvár, Szeged, Pécs and Debrecen. Its function was to carry out a continual interest-promoting discourse on issues of the practical needs of secondary education with university faculties referring to the Humboldtian idea as regards the freedom of teaching. Thanks to the 1924 Teacher Training Act, the training institutes in the capital and provincial cities gained strong legitimacy, in the wake of which with their definied licenses remarkable achievements were made in harmonizing the components of teacher training