Cluster growth in far-from-equilibrium particle models with diffusion, detachment, reattachment and deposition

Monolayer cluster growth in far-from-equilibrium systems is investigated by applying simulation and analytic techniques to minimal hard core particle (exclusion) models. The first model (I), for post-deposition coarsening dynamics, contains mechanisms of diffusion, attachment, and slow activated detachment (at rate epsilon<<1) of particles on a line. Simulation shows three successive regimes of cluster growth: fast attachment of isolated particles; detachment allowing further (epsilon t)^(1/3) coarsening of average cluster size; and t^(-1/2) approach to a saturation size going like epsilon^(-1/2). Model II generalizes the first one in having an additional mechanism of particle deposition into cluster gaps, suppressed for the smallest gaps. This model exhibits early rapid filling, leading to slowing deposition due to the increasing scarcity of deposition sites, and then continued power law (epsilon t)^(1/2) cluster size coarsening through the redistribution allowed by slow detachment. The basic (epsilon t)^(1/3) domain growth laws and epsilon^(-1/2) saturation in model I are explained by a simple scaling picture. A second, fuller approach is presented which employs a mapping of cluster configurations to a column picture and an approximate factorization of the cluster configuration probability within the resulting master equation. This allows quantitative results for the saturation of model I in excellent agreement with the simulation results. For model II, it provides a one-variable scaling function solution for the coarsening probability distribution, and in particular quantitative agreement with the cluster length scaling and its amplitude.Comment: Accepted in Phys. Rev. E; 9 pages with figure

Finitely generated ideal languages and synchronizing automata

We study representations of ideal languages by means of strongly connected synchronizing automata. For every finitely generated ideal language L we construct such an automaton with at most 2^n states, where n is the maximal length of words in L. Our constructions are based on the De Bruijn graph.Comment: Submitted to WORDS 201

Tissue engineering : key elements and some trends

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Indicators for the assessment of social resilience in flood-affected communities – A text mining-based methodology

This work turns the social resilience concept into a practical and tangible set of dimensions and indicators for social resilience assessment. It further provides an analysis of the social resilience concept in the context of flood risk governance. Floods are a worldwide recurring phenomenon that causes severe social, economic and environmental losses. In the context of global change, it is very difficult to accurately predict extreme events that may increase disaster frequency; hence the implementation of social resilience is essential to lessen the losses. Indeed, the right balance between natural and social factors and indicators is yet to be found. Social resilience has been debated extensively for decades, both in scientific and political contexts. It has been a concern in disaster risk reduction and risk governance fields, both of which have strived to implement it. The enlarged conceptual discussion regarding this topic has resulted in some indicator-based assessments that hardly reflect the conceptual discussion developed so far. These indicator-based approaches still lack accurate inclusion of social dynamics and the capacity to learn from experience. In order to contribute to a comprehensive approach (concept and methods) for assessing social resilience to floods, the evolutionary resilience concept (Davoudi, Simin; Shaw, Keith; Haider, L. Jamila; Quilnlan, Allyson E; Petterson, Garry D.; Wilkinson, Cathy; Fünfgeld, Hartmut; McEvoy, Darryn; Porter, 2012) was considered as a reference in this work, as it can include dimensions that are difficult to evaluate (non-static time and learning-capacity in multi-dimensional systems). This work addresses the challenge of a conceptual overview of social resilience to include key factors and indicators. Our methodology uses text mining, experts' surveys and bibliography reviews to generate an indicators database. The contribution of this article to the scientific debate on social resilience assessment is twofold. First, the key-concepts, words and expressions in this field are identified, which provides the basis to build a comprehensive and coherent analytical framework. Secondly, an original indicators database is proposed in line with that framework. The results of a text mining-based methodology and an online survey, involving experts from different countries, show that four of the six dimensions of the indicators database refer to social aspects of risks (Individuals, Society, Governance, and Built Environment), while the remaining two refer to the Environment and Disaster. The results obtained so far suggest the need for a next step aiming to validate the dimensions and the indicators of this database through its application to real case studies.info:eu-repo/semantics/publishedVersio

Cork biomass biocomposites: lightweight and sustainable materials

Chapter 17. Cork biomass biocomposites: lightweight and sustainable materials.The authors would like to thank to the financial support from the Portuguese Foundation for Science and Technology (FCT) for the fellowship grant of Emanuel M. Fernandes (SFRH/BPD/96197/2013), “Fundo Social Europeu”- FSE and “Programa Diferencial de Potencial Humano POPH”.info:eu-repo/semantics/publishedVersio

Adipose tissue-derived stem cells and their application in bone and cartilage tissue engineering

The adipose tissue was considered a reserve of energy until the ’80s, when it was found that this tissue was involved in the metabolism of sex steroids such as estrogens. From then on, the importance attributed to this tissue radically changed as it was then considered an active organ, involved in important functions of the human body. In 2001, for the first time, the existence of stem cells within this tissue was reported, and since then, this tissue has been gaining an increased importance as a stem cell source for a wide range of potential applications in cell therapies and=or tissue engineering and regenerative medicine strategies, mainly due to its wide availability and easy access. This manuscript provides an overview on adipose stem cells (i.e., adipose tissue–derived stem cells, ASCs) considering the tissue of origin, the niche of the ASCs, and their phenotype in all aspects. In this paper it is also discussed the markers that have been used for the characterization of these cells, their differentiation properties, and their immunological reactivity, reporting studies from 2001 until this date. The ASCs are also compared with bone marrow stem cells (BMSCs), until now considered as the gold standard source of stem cells, underlining the common characteristics and the differences between the stem cells obtained from these two sources, as well as the advantages and disadvantages of their potential use in different applications. Finally, this review will also focus on the potential application of ASCs in tissue engineering applications, particularly in the regeneration of bone and cartilage, commenting on the progress of this approach and future trends of the field.T. Rada thanks the European Marie Curie EST Project (Alea Jacta Est) for the Ph. D. fellowship. The authors acknowledge the Portuguese Foundation for Science and Technology (FCT) for the partial financial support through funds from POCTI and/or FEDER programs and to the European Union funded STREP Project HIPPOCRATES (NMP3-CT-2003-505758) and the European NoE EXPER-TISSUES (NMP3-CT-2004-500283)

In vivo skin hydrating efficacy of fish collagen from greenland halibut as a high-value active ingredient for cosmetic applications

The industrial processing of fish for food purposes also generates a considerable number of by-products such as viscera, bones, scales, and skin. From a value-added perspective, fish by-products can act also as raw materials, especially because of their collagen content (particularly in fish skin). Interestingly, the potential of marine collagen for cosmetic applications is enormous and, remarkably, the extraction of this protein from fish skins has been established for different species. Using this approach, we investigated the integration of marine collagen (COLRp_I) extracted from the skin of the Greenland halibut as an active ingredient in a cosmetic hydrogel formulation. In this study, extracts of marine collagen at concentrations up to 10 mg/mL showed a non-cytotoxic effect when cultured with fibroblast cells for 3 days. In addition, marine collagen extract, when incorporated into a cosmetic hydrogel formulation, met criterion A of ISO 11930:2019 regarding the efficacy of the preservative system (challenge test). In addition, the cosmetic formulations based on marine collagen at dosages of 0.1, 0.25 and 0.5% were tested in a clinical study on the skin of the forearms of 23 healthy volunteers, showing a sightly hydration effect, suggesting its potential for beauty applications. Moreover, this work illustrates that the circular economy concept applied to the fish processing industry can represent important benefits, at innovation, environmental and economic levels.The authors acknowledge the funding from the European Union Transborder Cooperation Programme Interreg España-Portugal 2014–2020 (POCTEP) under the project 0302_CVMAR_I_1_P, which supported also the cosmetic clinical study performed by INOVAPOTEK under a services acquisition contract

Polyethylene composites with lignocellulosic material

The aim of this chapter is to describe in detail the advances in polyethylene reinforced with lignocellulosic material. Indeed, the successful employment of natural based materials to reinforce/improve the properties of polyolefins has been growing in a wide range of applications. Firstly, basic concepts and terminology adopted in the lignocellulosic composite materials are reviewed. The objective is to bring the readerâ s attention to important issues that must to be taken into account when working in this subject as well as by providing the most appropriate references for those with interest to delve into the topic. In the context of polyethylene lignocellulosic composites, ongoing research is then summarised mainly focussing on (i) the main aspects related to the selection of the commonly used lignocellulosic materials and the potential of its main chemical constituents, (ii) the principal methods used for the improvement of interfacial adhesion and (iii) the main adopted processing routes and the composite properties. Finally, applications, new challenges and opportunities of these polyethylene-lignocellulosic composites are also discussed.(undefined)info:eu-repo/semantics/publishedVersio