Heesup Choi; Masumi Inoue; Risa Sengoku; Hyeonggil Choi
Abstract
In this study, it is possible to disperse effectively cracked using synthetic fiber, an examination of the most suitable self-healing conditions was performed on the above crack width 0.1mm. As a result, effective crack dispersion using polyvinyl alcohol (PVA) fibers with polar OH - groups, as well as ...
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In this study, it is possible to disperse effectively cracked using synthetic fiber, an examination of the most suitable self-healing conditions was performed on the above crack width 0.1mm. As a result, effective crack dispersion using polyvinyl alcohol (PVA) fibers with polar OH - groups, as well as improved self-healing for cracks that are larger than 0.1 mm in width, posing concerns of CO2 gas and Cl - penetration, were observed. Also, CO3 2- reacts with Ca 2+ in the concrete crack, resulting in the precipitation of a carbonate compound, CaCO3. Based on this, it is deemed possible for the recovery of effective water tightness and strength recovery through effective freezing-thawing resistance to be made from cracks that are larger than 0.1 mm in width. In addition, it was determined that, as for the most suitable self-healing conditions in the inside and surface of the cracks, calcium hydroxide (Ca(OH)2) solution with CO2 micro-bubble was more effective in promoting the self-healing capability than water with CO2 micro-bubble.
Mohammed Menhal Shbeh; Russell Goodall
Abstract
Titanium foams are advanced materials with macroporous structure that have a great potential in a variety of areas such as biomedical and functional applications. They are characterized by their reduced density and stiffness, with high permeability and excellent biocompatibility. One production technique ...
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Titanium foams are advanced materials with macroporous structure that have a great potential in a variety of areas such as biomedical and functional applications. They are characterized by their reduced density and stiffness, with high permeability and excellent biocompatibility. One production technique for Ti foams with promising results is Metal Injection Moulding (MIM). So far most of the porous titanium produced by this technique has a very basic design with low percentage of porosity, thus limiting its potential in the biomedical industry, among others. In this study, the use of MIM in combination with a space holder to produce single and multi-layered porous Ti with high volume percentage of porosity will be explored. The results show that it is possible to produce Ti foam with a total volume percentage of porosity of 61 % through MIM technology. In addition, it is also feasible to combine different porous layers resulting in multi-layered porous titanium parts with gradient porosity that could have a huge potential in a wide range of applications, especially for biomedical implants, where these pores can promote bone ingrowth as well as reduce stiffness to match that of the natural bone, thus alleviating the stress shielding problem.
V. Saikiran; N. Manikanthababu; N. Srinivasa Rao; S. V. S. Nageswara Rao; A. P. Pathak
Abstract
Trilayered HfO2/Ge/HfO2 thin films were grown on Si substrate by RF magnetron sputtering with HfO2 and Ge targets. The subsequent rapid thermal annealing (RTA) of these films at 700 & 800°C results in formation of Ge nanocrystals (NCs) in HfO2 matrix. X-ray diffraction (XRD) and micro-Raman spectroscopy ...
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Trilayered HfO2/Ge/HfO2 thin films were grown on Si substrate by RF magnetron sputtering with HfO2 and Ge targets. The subsequent rapid thermal annealing (RTA) of these films at 700 & 800°C results in formation of Ge nanocrystals (NCs) in HfO2 matrix. X-ray diffraction (XRD) and micro-Raman spectroscopy measurements were performed to confirm the formation of Ge NCs in the annealed samples. XRD results indicate that the as-deposited samples show amorphous behaviour, whereas the annealed samples clearly confirm the crystallinity of the films. The average size of the Ge NCs was found to increase with an increase in annealing temperature. Raman scattering studies confirm that the annealed samples exhibit a shift in peak position corresponding to Ge-Ge optical phonon vibrations, which clearly indicates the formation of Ge NCs. Conversely, as-deposited samples were also irradiated with swift heavy ions of 150 MeV Au and 80 MeV Ni at a fluence of 3×10 13 ions/cm 2 to synthesize Ge NCs. The structural properties of pristine and irradiated samples have been studied by using X-ray diffraction, Raman spectroscopy to substantiate the growth of Ge NCs upon irradiation. The results obtained by RTA are compared with the irradiated ones.
A. Kumar;Somik Banerjee
Abstract
Structural and conformational modifications in conducting polymer nanostructures viz., Polyaniline (PAni) nanofibers induced by swift heavy ion (SHI) irradiation have been investigated employing TEM, XRD, UV-Vis, FTIR and micro-Raman spectroscopy. Upon interaction with the highly energetic ions, PAni ...
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Structural and conformational modifications in conducting polymer nanostructures viz., Polyaniline (PAni) nanofibers induced by swift heavy ion (SHI) irradiation have been investigated employing TEM, XRD, UV-Vis, FTIR and micro-Raman spectroscopy. Upon interaction with the highly energetic ions, PAni nanofibers are fragmented and get amorphized. The local range of order is found to decrease with a corresponding increase in the concentration of point defects and dislocations leading to the enhancement in strain. Vibrational spectra of the pristine and SHI irradiated PAni nanofibers studied using FTIR and micro-Raman (μR) spectroscopy indicate conformational changes in PAni nanofibers upon SHI irradiation. Loss of π-stacking due to the enhancement in the torsion angle between Cring-N-Cring upon irradiation is indicative of strong electrostatic interaction between the electron rich C-N site in the aromatic rings of PAni chains and the ion beam. The most significant variation in PAni nanofibers upon SHI irradiation is the transformation of para di-substituted benzene (benzenoid) structure of PAni into the quinone di-imine (quinoid) structures; a phenomenon that has been simultaneously observed in both the FTIR and Raman spectra. The presence of two main peaks representing the same structures in PAni nanofibers in both the Raman and IR spectra is because of the presence of delocalized sp2 phases and local disorder in PAni nanofibers, which gives rise to electrical and mechanical fluctuations that destroy the symmetry rules.
Yoshiaki Hirano; Katsutoshi Ooe; Kazuyoshi Tsuchiya; Tomohiro Hosokawa; Kazuto Koike; Shigehiko Sasa
Abstract
A health monitoring system (HMS) involving a blood extraction device with a new type of hybrid biosensor comprising an enzyme and a semiconductor has recently been developed. A MOSFET was used as the transducer. The gate electrode was extracted from the MOSFET using a cable. Gold (Au)-plate-immobilized ...
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A health monitoring system (HMS) involving a blood extraction device with a new type of hybrid biosensor comprising an enzyme and a semiconductor has recently been developed. A MOSFET was used as the transducer. The gate electrode was extracted from the MOSFET using a cable. Gold (Au)-plate-immobilized glucose oxidase (Go) was used as a biosensor and attached to the gate electrode. Go was immobilized on a self-assembled spacer combined with an Au electrode by the cross-link method using BSA as an additional bonding material. The electrode could be used to detect electrons generated by the oxidization of hydrogen peroxide produced by the reaction between Go and glucose using the constant electric current measurement system of the MOSFET-type hybrid biosensor. The sensitivities for the diluted whole blood and blood plasma were 61.4 and 171.2 V/(mol/L), respectively. The hybrid biosensor was useful for HMS.
