A BIM-based theoretical framework for the integration of the asset End-of-Life phase

Due to the migration of industry from the use of traditional 2D CAD tools to Building Information Modelling (BIM) process, and the growing awareness of Construction and Demolition (C&D) waste issues, researchers are interested in compiling the use of BIM for C&D Waste issues. BIM is commonly used for the Design, Construction and Maintenance phases of an asset; however, the use of BIM for the End-of-Life management is still in its infancy. This paper proposes to reconsider the asset lifecycle by incorporating a sustainable End-of-Life, as a phase, in BIM context. Recommendations are given to push the BIM potential up to the asset End-of-Life management. Based on the results of a literature review assessing the current use of BIM for the asset End-of-Life, a conceptual framework was drawn. A set of eleven stakeholders, involved in the asset lifecycle, from inception to deconstruction were interviewed to improve the conceptual framework. The research reveals the impacts and barriers for the integration of the deconstruction phase into the asset lifecycle. Consequently, a theoretical framework for the asset lifecycle from inception to deconstruction in BIM environment is created to change the linear system to a circular economy.Peer reviewe

Pattern recognition receptors in immune disorders affecting the skin.

Contains fulltext : 109004.pdf (publisher's version ) (Open Access)Pattern recognition receptors (PRRs) evolved to protect organisms against pathogens, but excessive signaling can induce immune responses that are harmful to the host. Putative PRR dysfunction is associated with numerous immune disorders that affect the skin, such as systemic lupus erythematosus, cryopyrin-associated periodic syndrome, and primary inflammatory skin diseases including psoriasis and atopic dermatitis. As yet, the evidence is often confined to genetic association studies without additional proof of a causal relationship. However, insight into the role of PRRs in the pathophysiology of some disorders has already resulted in new therapeutic approaches based on immunomodulation of PRRs

Towards osteogenic and bactericidal nanopatterns?

Recent discoveries have shown that nanopatterns with feature sizes ≤100 nm could direct stem cell fate or kill bacteria. These effects could be used to develop orthopedic implants with improved osseointegration and decreased chance of implant-associated infections. The quest for osteogenic and bactericidal nanopatterns is ongoing but no controlled nanopatterns with dual osteogenic and bactericidal functionalities have been found yet. In this study, electron beam induced deposition (EBID) was used for accurate and reproducible decoration of silicon surfaces with four different types of nanopatterns. The features used in the first two nanopatterns (OST1 and OST2) were derived from osteogenic nanopatterns known to induce osteogenic differentiation of stem cells in the absence of osteogenic supplements. Two modifications of these nanopatterns were also included (OST2-SQ, OST2-H90) to study the effects of controlled disorder and lower nanopillar heights. An E. coli K-12 strain was used for probing the response of bacteria to the nanopatterns. Three nanopatterns (OST2, OST2-SQ, and OST2-H90) exhibited clear bactericidal behavior as evidenced by severely damaged cells and disrupted formation of extracellular polymeric substance. These findings indicate that controlled nanopatterns with features derived from osteogenic ones can have bactericidal activity and that EBID represents an enabling nanotechnology to achieve (multi)functional nanopatterns for bone implants.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.BT/BiocatalysisBiomaterials & Tissue BiomechanicsImPhys/Charged Particle Optic

Nature helps: Toward bioinspired bactericidal nanopatterns

Development of synthetic bactericidal surfaces is a drug-free route to the prevention of implant-associated infections. Surface nanotopographies with specific dimensions have been shown to kill various types of bacterial strains through a mechanical mechanism, while regulating stem cell differentiation and tissue regeneration. The effective ranges of dimensions required to simultaneously achieve both aims are in the <200 nm range. Here, a nanoscale additive manufacturing (=3D printing) technique called electron beam induced deposition (EBID) is used to fabricate nanopillars with reproducible and precisely controlled dimensions and arrangements that are within those effective ranges (i.e. a height of 190 nm, a diameter of 80 nm, and an interspacing of 170 nm). When compared to the flat surface, the nanopatterned surfaces show a significant bactericidal activity against both Escherichia coli and Staphylococcus aureus (with respective killing efficiencies of 97 ± 1% and 36 ± 5%). Direct penetration of nanopatterns into the bacterial cell wall leads to the disruption of the cell wall and cell death. The more rigid cell wall of S. aureus is consistent with the decreased killing efficiency. These findings support the development of nanopatterns with precisely controlled dimensions that are capable of killing both Gram-negative and Gram-positive bacteria.Biomaterials & Tissue BiomechanicsBT/BiocatalysisImPhys/Charged Particle Optic

Extrusion-Spheronization of Talc using Microcrystalline Cellulose as a Pellet Aid: Part I

NoThe aims of the present work were to pelletize talc by extrusion-spheronization technique using microcrystalline cellulose (MCC) as a pelletization aid and to study its performance as a neutral substrate for coating. A 32 factorial design was used to study the effect of independent variables (X1, amount of talc, and X2, MCC) on pellet properties