Visualization of the modeled degradation of building flooring systems in building maintenance

The development of a maintenance programme for construction projects is a highly complex and data intensive undertaking. This exercise is characterised by the lack of relevant data on the one hand and the overwhelming amount of extraneous data on the other. The uncertainties and complexities have resulted in increased conservatism in the development of lifecycle evaluation of building maintenance programing, subsequently, these programmes tend to display the symptoms of either the maintenance actions being uneconomical or fall short of providing the appropriate service to the users of the building. The current research project is based on the premise that the visual approach will facilitate a just-in-time solution to maintenance scheduling, hence, the use of virtual simulation of the building is proposed. The broader aim of this research is to develop a complete building maintenance programme through visualisation of buildings as they degrade over time. Here, the focus is on the flooring system and the manner they degrade over time. This requires a better understanding of their pattern and rate of usage. To this end, Anthroposophy and Anthropocentric descriptions of human movement pattern have been used to describe the behaviour of 'subjects' and subsequently represent the pattern and density of the degradation of flooring systems. The mathematics representing this behaviour has been developed which enables it to be embedded into the proposed overall visual building maintenance model

Reconstructive Phase Transition in Ultrashort Peptide Nanostructures and Induced Visible Photoluminescence

A reconstructive phase transition has been found and studied in ultrashort di- and tripeptide nanostructures, self-assembled from biomolecules of different compositions and origin such as aromatic, aliphatic, linear, and cyclic (linear FF-diphenylalanine, linear LL-dileucine, FFF-triphenylalanine, and cyclic FF-diphenylalanine). The native linear aromatic FF, FFF and aliphatic LL peptide nanoensembles of various shapes (nanotubes and nanospheres) have asymmetric elementary structure and demonstrate nonlinear optical and piezoelectric effects. At elevated temperature, 140–180 °C, these native supramolecular structures (except for native Cyc-FF nanofibers) undergo an irreversible thermally induced transformation via reassembling into a completely new thermodynamically stable phase having nanowire morphology similar to those of amyloid fibrils. This reconstruction process is followed by deep and similar modification at all levels: macroscopic (morphology), molecular, peptide secondary, and electronic structures. However, original Cyc-FF nanofibers preserve their native physical properties. The self-fabricated supramolecular fibrillar ensembles exhibit the FTIR and CD signatures of new antiparallel β-sheet secondary folding with intermolecular hydrogen bonds and centrosymmetric structure. In this phase, the β-sheet nanofibers, irrespective of their native biomolecular origin, do not reveal nonlinear optical and piezoelectric effects, but do exhibit similar profound modification of optoelectronic properties followed by the appearance of visible (blue and green) photoluminescence (PL), which is not observed in the original peptides and their native nanostructures. The observed visible PL effect, ascribed to hydrogen bonds of thermally induced β-sheet secondary structures, has the same physical origin as that of the fluorescence found recently in amyloid fibrils and can be considered to be an optical signature of β-sheet structures in both biological and bioinspired materials. Such PL centers represent a new class of self-assembled dyes and can be used as intrinsic optical labels in biomedical microscopy as well as for a new generation of novel optoelectronic nanomaterials for emerging nanophotonic applications, such as biolasers, biocompatible markers, and integrated optics

Photoluminescence and Surface Photovoltage Spectroscopy Studies of Hydroxyapatite Nano-Bio-Ceramics

Photoluminescence (PL) and surface photovoltage spectroscopy applied to nanostructural bioceramics hydroxyapatite (HAp) allowed to study electron (hole) energy states spectra of HAP and distinguish bulk and surface localized levels. Studied PL excitation spectra allowed obtaining an exact value of the energy band gap in HAP: Eg=3.95 eV.This result is consistent with Eg value determined by the contact potential difference (ΔCPD) curves treatment method as Eg=3.94 eV. Comparison between ΔCPD and PL spectra indicates that the energy spectra of electron – hole levels studied by two different experimental spectroscopy techniques are very similar. This comparison enables to conclude that all HAp samples have identical electron – hole states structures consisting of five bulk states and one surface state. It is assumed that the deep electron (hole) charged states may be responsible for high bioactivity of the HAp nanoceramics

Electronic States Spectroscopy of Hydroxyapatite Ceramics

Photoluminescence, surface photovoltage spectroscopy and high-resolution characterization methods (Atomic Force Microscopy, Scanning Electron Microscopy, X-ray spectroscopy and DC conductivity) are applied to nanostructured Hydroxyapatite (HAp) bioceramics and allowed to study electron (hole) energy states spectra of the HAp and distinguish bulk and surface localized levels. The measured trap spectra show strong sensitivity to preliminary heat treatment of the ceramics. It is assumed that found deep electron (hole) charged states are responsible for high bioactivity of the HAp nanoceramics

Electronic states spectroscopy of Hydroxyapatite ceramics

Photoluminescence, surface photovoltage spectroscopy and high-resolution characterization methods (Atomic Force Microscopy, Scanning Electron Microscopy, X-ray spectroscopy and DC conductivity) are applied to nanostructured Hydroxyapatite (HAp) bioceramics and allowed to study electron (hole) energy states spectra of the HAp and distinguish bulk and surface localized levels. The measured trap spectra show strong sensitivity to preliminary heat treatment of the ceramics. It is assumed that found deep electron (hole) charged states are responsible for high bioactivity of the HAp nanoceramics

Photoluminescence and surface photovoltage spectroscopy studies of hydroxyapatite nano-Bio-ceramics

Photoluminescence (PL) and surface photovoltage spectroscopy applied to nanostructural bioceramics hydroxyapatite (HAp) allowed to study electron (hole) energy states spectra of HAP and distinguish bulk and surface localized levels. Studied PL excitation spectra allowed obtaining an exact value of the energy band gap in HAP: Eg=3.95 eV.This result is consistent with Eg value determined by the contact potential difference (ΔCPD) curves treatment method as Eg=3.94 eV. Comparison between ΔCPD and PL spectra indicates that the energy spectra of electron – hole levels studied by two different experimental spectroscopy techniques are very similar. This comparison enables to conclude that all HAp samples have identical electron – hole states structures consisting of five bulk states and one surface state. It is assumed that the deep electron (hole) charged states may be responsible for high bioactivity of the HAp nanoceramics