The role of new material technologies for sustainable practice in the concrete industry

Author(s):  
Michael Henry ◽  
Yoshitaka Kato
2019 ◽  
Vol 10 (4) ◽  
pp. 56 ◽  
Author(s):  
Hamid Mortazavian ◽  
Guillaume A. Picquet ◽  
Jānis Lejnieks ◽  
Lynette A. Zaidel ◽  
Carl P. Myers ◽  
...  

In this study, we have prepared a series of 4- and 6-arm star-shaped polymers with varying molecular weight and hydrophobicity in order to provide insight into the role and relationship that shape and composition have on the binding and protecting of oral relevant surfaces (hydroxyapatite, HAP) from bacteria colonization. Star-shaped acrylic acid polymers were prepared by free-radical polymerization in the presence of chain transfer agents with thiol groups, and their binding to the HAP surfaces and subsequent bacteria repulsion was measured. We observed that binding was dependent on both polymer shape and hydrophobicity (star vs. linear), but their relative efficacy to reduce oral bacteria attachment from surfaces was dependent on their hydrophobicity only. We further measured the macroscopic effects of these materials to modify the mucin-coated HAP surfaces through contact angle experiments; the degree of angle change was dependent on the relative hydrophobicity of the materials suggesting future in vivo efficacy. The results from this study highlight that star-shaped polymers represent a new material platform for the development of dental applications to control bacterial adhesion which can lead to tooth decay, with various compositional and structural aspects of materials being vital to effectively design oral care products.


2016 ◽  
Vol 48 (3) ◽  
pp. 292-310 ◽  
Author(s):  
Beverley Hawkins ◽  
Annie Pye ◽  
Fernando Correia

This article develops an understanding of the agential role of boundary objects in generating and politicizing learning in organizations, as it emerges from the entangled actions of humans and non-humans. We offer two empirical vignettes in which middle managers seek to develop more sustainable ways of working. Informed by Foucault’s writing on power, our work highlights how power relations enable and foreclose the affordances, or possibilities for action, associated with boundary objects. Our data demonstrate how this impacts the learning that emerges as boundary objects are configured and unraveled over time. In so doing, we illustrate how boundary objects are not fixed entities, but are mutable, relational, and politicized in nature. Connecting boundary objects to affordances within a Foucauldian perspective on power offers a more nuanced understanding of how ‘the material’ plays an agential role in consolidating and disrupting understandings in the accomplishment of learning.


2009 ◽  
Vol 59 (2) ◽  
pp. 147-161 ◽  
Author(s):  
Kari Dyregrov

Little knowledge has been documented on the experiences of young suicide survivors, how they are coping with schooling and what kind of support they think they need. Thirty-two adolescents who had lost a close family member or friend by suicide participated in a research project by filling in questionnaires and participating in focus group interviews. The article explores the young people's experiences with and wishes for help from the school, including teachers and school nurses. The results show that the young people struggle with concentration and learning new material. Although many are satisfied with care and support while at school, the young bereaved do not receive all the assistance they wish for and need. In order to adequately support young suicide survivors to continue schooling, it is worth listening to their opinions about how they may be approached.


2014 ◽  
Vol 644-650 ◽  
pp. 4896-4899
Author(s):  
Wen Shi Mao

Modern decorative materials constantly updated and developed, and many of them are limited tube used for a time, and soon are replaced or eliminated. Soft adornment material can shape and express art atmosphere of indoor, having huge advantages and functions. In this paper, we research and analyze the soft adornment material from different point of view, and making catch-all category on the function of indoor soft adornment material that will be used in art design environmental. Soft adornment material has a great influence on the indoor space, such as people's sense of feel, smell, etc. Also from the angle of the color and design, as well as the texture analysis to analyze the utilization of soft decoration materials in interior design, and emphasized on low carbon green theme, highlighting the new idea of interior design, and also excusing the advantages of the new material.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8292 ◽  
Author(s):  
Shunxing Jiang ◽  
Zhiheng Li ◽  
Xin Cheng ◽  
Xiaolin Wang

The pterosaur is the first known vertebrate clade to achieve powered flight. Its hyoid apparatus shows a simplification similar to that of birds, although samples of the apparatus are rare, limiting the ability to make an accurate determination. In this study we reveal a new pterosaur specimen, including the first definite basihyal. Through the comparison of pterosaur hyoids, a trend has been discovered for the shortened hyoid relative to the length of the skull, indicating a diminished role of lingual retraction during the evolution of the pterosaur. The new material, possibly from a gallodactylid Gladocephaloideus, represents one of the least effective lingual retractions in all pterosaurs. Based on the structure of an elongated ceratobranchial and retroarticular process on mandibles, the function of the Y-shaped istiodactylid tongue bone is similar to those of scavenger crows rather than chameleons, which is consistent with the interpretation of the scavenging behavior of this taxon. More fossil samples are needed for further study on the function of other pterosaur hyoids.


Lituanistica ◽  
2020 ◽  
Vol 65 (4) ◽  
Author(s):  
Aurelijus Gieda

It has been emphasised on several occasions that Professor Eduard Wolter was a prominent figure and a broad-profile humanitarian in the history of Lithuanian humanities, who for many decades was actively interested in Lithuanian studies, among other things. The revolutionary changes in Russia divided Wolter’s academic career into two unequal parts: nearly forty years of academic work in Tsarist Russia and thirteen years in Kaunas. Bearing in mind the status of academic Lithuanian studies at the beginning of the twentieth century, his was an unprecedented case in Lithuania until 1940. We can claim that before 1940, no other Lithuanian humanitarian had such a long academic career of several decades devoted to Lithuanian studies. However, we still do not have an academic biography of Wolter, and Stasė Bušmienė’s work Eduardas Volteris, published almost 50 years ago, remains the most comprehensive publication in the field. Because of these circumstances, we must search for new problematic aspects, updated interpretations, and new material-based approaches. The article analyses the context of the revolutionary changes in Russia, the role of Augustinas Voldemaras in the history of the Wolters’ emigration, and Prof. Wolter’s recurrent concern about the academic possessions he had left in St. Petersburg when he was already in Lithuania. This article seeks new solutions: the emigration of the Wolter family to Lithuania is viewed as a potentially crucial knot in the professor’s biography. It allows understanding and linking two seemingly very different stages in his biography (Tsarist Russia and independent Lithuania). Lithuanian research interests and the related circle of like-minded people that had evolved in the course of many decades form a consistent deep-rooted epicentre of Prof. Wolter’s biography. The research method chosen imparts inner integrity to the biography of Prof. Wolter and an opportunity to look into the path of this scholar, who was also a member of the Russian Academy of Sciences, in the long term perspective. This text develops and substantiates the thesis that scholars’ emigration from Bolshevik Russia took place under dire circumstances: they had to leave not only their homes but also their libraries behind, their manuscripts and much of the material accumulated over many decades of academic work. Also, from the point of view of a collective biography, the context of the loss of the old University of St. Petersburg after the Bolshevik takeover in Russia is shown. While in Lithuania, Prof. Wolter made great efforts to recover the manuscripts, the library, and the collections he had left behind in St. Petersburg. This moment justifies the emigration of the Wolter family to Lithuania as a relevant key to the whole biography of Prof. Wolter. For the first time in historiography, the article gives a detailed analysis of Augustinas Voldemaras’ 53 letters to Alexandra Wolter (translated and published by Gediminas Rudis). The letters offer an interesting and characteristic description of the actual circumstances of the emigration of the Wolter family to Lithuania. This correspondence reveals a special connection between Voldemaras and the Wolter family. Voldemaras, who had lived in the Wolters’ house in St. Petersburg for over a decade, became a true family member, and their communication in the process of the emigration of the Wolter family was best described as close familial relations. In this way, the article sheds light on the role of Prof. Voldemaras in the relocation of the Wolter family to Lithuania, which did not find reflection either in Wolter’s biography or in general historiography.


1998 ◽  
Vol 62 (1) ◽  
pp. 181-203 ◽  
Author(s):  
Joachim-Volker Höltje

SUMMARY To withstand the high intracellular pressure, the cell wall of most bacteria is stabilized by a unique cross-linked biopolymer called murein or peptidoglycan. It is made of glycan strands [poly-(GlcNAc-MurNAc)], which are linked by short peptides to form a covalently closed net. Completely surrounding the cell, the murein represents a kind of bacterial exoskeleton known as the murein sacculus. Not only does the sacculus endow bacteria with mechanical stability, but in addition it maintains the specific shape of the cell. Enlargement and division of the murein sacculus is a prerequisite for growth of the bacterium. Two groups of enzymes, hydrolases and synthases, have to cooperate to allow the insertion of new subunits into the murein net. The action of these enzymes must be well coordinated to guarantee growth of the stress-bearing sacculus without risking bacteriolysis. Protein-protein interaction studies suggest that this is accomplished by the formation of a multienzyme complex, a murein-synthesizing machinery combining murein hydrolases and synthases. Enlargement of both the multilayered murein of gram-positive and the thin, single-layered murein of gram-negative bacteria seems to follow an inside-to-outside growth strategy. New material is hooked in a relaxed state underneath the stress-bearing sacculus before it becomes inserted upon cleavage of covalent bonds in the layer(s) under tension. A model is presented that postulates that maintenance of bacterial shape is achieved by the enzyme complex copying the preexisting murein sacculus that plays the role of a template.


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