Creep behavior of poly(lactic acid) based biocomposites

Polymer composites containing natural fibers are receiving growing attention as possible alternatives for composites containing synthetic fibers. The use of biodegradable matrices obtained from renewable sources in replacement for synthetic ones is also increasing. However, only limited information is available about the creep behavior of the obtained composites. In this work, the tensile creep behavior of PLA based composites, containing flax and jute twill weave woven fabrics, produced through compression molding, was investigated. Tensile creep tests were performed at different temperatures (i.e., 40 and 60 \ub0C). The results showed that the creep behavior of the composites is strongly influenced by the temperature and the woven fabrics used. As preliminary characterization, quasi-static tensile tests and dynamic mechanical tests were carried out on the composites. Furthermore, fabrics (both flax and jute) were tested as received by means of quasi-static tests and creep tests to evaluate the influence of fabrics mechanical behavior on the mechanical response of the resulting composites. The morphological analysis of the fracture surface of the tensile samples showed the better fiber-matrix adhesion between PLA and jute fabric

Durability of biodegradable polymers for the conservation of cultural heritage

The use of polymers for conservation of cultural heritage is related to the possibility to slow down or stop natural deterioration which, in many cases, corresponds to stopping the entrance of liquid water and to favor spontaneous water vapor removal. Unfortunately, hydrophobicity is generally favored by surface roughness and thus competitive with transparency. It is therefore important to find an optimal balance hydrophobicity, transparency and durability (especially to photooxidation). However, polymers typically used for applications in this field come from non-renewable resources and are not biodegradable. In this work, the mechanical, structural, and optical properties of PLA, PBAT, and a PBAT/PLA blends, as well as surface properties and water vapor permeability, were investigated before and after exposure to UV irradiation, in order to evaluate their durability and suitability for conservation of cultural heritage

Evaluating visitor experiences with interactive art

The Music Room is an interactive installation that allows visitor to compose classical music by moving throughout a space. The distance between them and their average speed maps the emotionality of music: in particular, distance influences the pleasantness of the music, while speed influences its intensity. This paper focuses on the evaluation of visitors' experience with The Music Room by examining log-data, video footages, interviews, and questionnaires, as collected in two public exhibitions of the installation. We examined this data to the identify the factors that fostered the engagement and to understand how players appropriated the original design idea. Reconsidering our design assumptions against behavioural data, we noticed a number of unexpected behaviours, which induced us to make some considerations on design and evaluation of interactive art

Elderly Onset Celiac Disease: A Narrative Review.

Celiac sprue is a chronic disease, which usually occurs in children and young adults. However, it can develop in any age group, and the prevalence is increasing even in the elderly population. The atypical patterns of clinical presentation in this age group sometimes can cause a delay in diagnosis. Given the lower sensitivity and specificity of serological tests in the aged population, clinical suspect often arises in the presence of complications (autoimmune disorders, fractures, and finally, malignancy) and must be supported by endoscopic and imaging tools. In this review, we highlight the incidence and prevalence of celiac disease in the elderly, the patterns of clinical presentation, diagnosis, and the most frequent complications, with the aim of increasing awareness and reducing the diagnostic delay of celiac disease even in the elderly populatio

Hedysarum coronarium-Based Green Composites Prepared by Compression Molding and Fused Deposition Modeling

In this work, an innovative green composite was produced by adding Hedysarum coronarium (HC) flour to a starch-based biodegradable polymer (Mater-Bi\uae, MB). The flour was obtained by grinding together stems, leaves and flowers and subsequently sieving it, selecting a fraction from 75 \ub5m to 300 \ub5m. Four formulations have been produced by compression molding (CM) and fused deposition modeling (FDM) by adding 5%, 10%, 15% and 20% of HC to MB. The influence of filler content on the processability was tested, and rheological, morphological and mechanical properties of composites were also assessed. Through CM, it was possible to obtain easily homogeneous samples with all filler amounts. Concerning FDM, 5% and 10% HC-filled composites proved also easily printable. Mechanical results showed filler effectively acted as reinforcement: Young\u2019s modulus and tensile strengths of the composites increased from 74.3 MPa to 236 MPa and from 18.6 MPa to 33.4 MPa, respectively, when 20% of HC was added to the pure matrix. FDM samples, moreover, showed higher mechanical properties if compared with CM ones due to rectilinear infill and fibers orientation. In fact, regarding the 10% HC composites, Young\u2019s modulus of the CM and FDM ones displayed a relative increment of 176% and 224%, respectively

Defining the Field: Revisiting the ACA 1995 Definition of Communication Studies

This article deals with the problem of defining communication studies in higher education. In 1995, the Association for Communication Administration (ACA) convened a summer conference that produced a two-sentence definition of the field of communication. More than 100 conferees voted their unanimous approval of the definition, which was then disseminated nationally and used by communication scholar/teachers for a multiplicity of purposes. Given the potential utility of that definition and the expansion of communication studies since 1995, the present study surveyed ACA\u27s current members to determine whether they are aware the definition exists, how they have used it, and the extent to which they perceive it as representative of communication studies today. The results of that survey are reported in this article, which begins with a description of why and how this definition was originally developed. In a field as diverse and eclectic as communication, a need exists for some commonality of understanding about what constitutes the discipline\u27s subject matter. Such understanding, in the form of a definition, can serve two functions: it can provide a descriptor of the diversity, breadth, and depth of the field itself; and, it can be used to represent the discipline to an external audience, both inside and outside of academe, many of whom may still hold onto the notion that the field is committed only to the practice and study of speech making

Consistency and Change: The (R)Evolution of the Basic Communication Course

The basic communication course, with its roots in classical Greece and Rome, is frequently a required course in general education. The course often serves as our “front porch,” welcoming new students to the Communication discipline. This essay first outlines early traditions in oral communication instruction and their influence on future iterations of the course. In addition, because fundamental changes in higher education in more modern times affected emphases and delivery of the course, we focus on the relationship between general education and the basic course and the significant curricular changes to the course during the latter part of the 20th century. Finally, we discuss ramifications of the evolution of the basic course, as the discipline moves forward into the 21st century

Why Communication is Important: A Rationale for the Centrality of the Study of Communication

This article defends the importance of studying communication. Academic disciplines in higher education are routinely called upon to explain and justify their role in the educational enterprise. Some academic fields such as history and philosophy are more central in the pursuits of liberal arts, while others such as business administration and engineering are more related to career development. The discipline of communication is fairly unique as it crosses these boundaries. As a result, a need exists to provide a rationale for the study of communication. The National Communication Association, in response to requests from communication departments and administrators for evidence supporting the centrality of their discipline, has collected and annotated nearly 100 articles, commentaries, and publications which call attention to the importance of the study of communication in contemporary society. Four of five major themes in the bibliography provide support for the importance of communication education to: the development of the whole person; the improvement of the educational enterprise; being a responsible citizen of the world, both socially and culturally; and, succeeding in one\u27s career and in the business enterprise. A fifth theme highlights the need for communication education to be provided by those who are specialists in its study

Differential expression of proteins in omental and subcutaneous adipose tissue related to sexual stedroids concentrations

Comunicaciones a congreso

Recent Developments and Formulations for Hydrophobic Modification of Carrageenan Bionanocomposites

Versatility of the anionic algal polysaccharide carrageenan has long been discussed and explored, especially for their affinity towards water molecules. While this feature is advantageous in certain applications such as water remediation, wound healing, etc., the usefulness of this biopolymer is extremely limited when it comes to applications such as food packaging. Scientists around the globe are carrying out research works on venturing diverse methods to integrate hydrophobic nature into these polysaccharides without compromising their other functionalities. Considering these foregoing studies, this review is designed to have an in-depth understanding of diverse methods and techniques adopted for tuning the hydrophobic nature of carrageenan-based bionanocomposites, both via surface alterations or by changes made to their chemical structure and attached functional groups. This review article mainly focuses on how the hydrophobicity of carrageenan bionanocomposites varies as a function of the type and refinement of carrageenan, and with the incorporation of additives including plasticisers, nanofillers, bioactive agents, etc. Incorporation of nanofillers such as polysaccharide-based nanoparticles, nanoclays, bioceramic and mineral based nanoparticles, carbon dots and nanotubes, metal oxide nanoparticles, etc., along with their synergistic effects in hybrid bionanocomposites are also dealt with in this comprehensive review article