GaN系半導体光電極のフラットバンドポテンシャルの研究

電気通信大学200

Creep properties of cement and alkali activated fly ash materials using nanoindentation technique

This paper presents creep properties of cement and alkali activated fly ash (AAFA) paste and mortar determined from statistical analysis of nanoindentation data. Cement paste having 95 MPa compressive strength at 28 days was tested for comparison and validation with a conventional test. Using nanoindentation, the specific creep of the cement paste after one year was predicted as 18.32 microstrain/MPa. For AAFA samples, an experimental program was set up using Taguchi's Design of Experiment method to consider four parameters, silica fume, sand to binder ratio, liquid to solid ratio, and superplasticiser, each with three variations.Using ANOVA, the percentage contributions of these parameters on the creep modulus of AAFA samples are: silica fume 26%, sand to binder ratio 21%, liquid to solid ratio 22%, and superplasticiser 31%. The results using de convolution technique to identify the creep modulus of different phases of AAFA matrices show that partly-activated, non-activated slag and non-activated compact glass phases are leading the creep behaviour of AAFA samples due to their high creep modulus. Compare to other parameters, the liquid to solid ratio contributes the most to the creep property of partly-activated slag, non-activated slag and non-activated compact glass phases, that is, 51%, 89%, 68%, respectively. Sand to binder ratio and superplasticiser have minor effect on the creep behaviour. The results of the creep properties of AAFA paste were then compared with those of AAFA concrete using an upscaling process. The creep rate of AAFA concrete was defined by the creep properties of the matrix and the interface between aggregates and matrix assuming perfect bonding and slip bonding conditions. The results from the upscaling process show that the creep properties of AAFA paste from nanoindentation are representative of the long-term creep properties of AAFA concrete determined from a conventional test method

Nonlinear Interactions Between Gravitational Radiation and Modified Alfven Modes in Astrophysical Dusty Plasmas

We present an investigation of nonlinear interactions between Gravitational Radiation and modified Alfv\'{e}n modes in astrophysical dusty plasmas. Assuming that stationary charged dust grains form neutralizing background in an electron-ion-dust plasma, we obtain the three wave coupling coefficients, and calculate the growth rates for parametrically coupled gravitational radiation and modified Alfv\'{e}n-Rao modes. The threshold value of the gravitational wave amplitude associated with convective stabilization is particularly small if the gravitational frequency is close to twice the modified Alfv\'en wave-frequency. The implication of our results to astrophysical dusty plasmas is discussed.Comment: A few typos corrected. Published in Phys. Rev.

Eosinophils and Oral Squamous Cell Carcinoma: A Short Review

The eosinophil cell has been related as a prognostic indicator for cancers. However, its exact function in tumour behaviour is still not clearly defined. In the oral cavity the presence of eosinophils can be a favourable prognostic indicator as well as it may be associated with a poor prognosis. In this short review, we briefly summarize the role of the eosinophils in the general context of immunoregulation and its relation to oral squamous cell carcinoma

Bioaccumulation of heavy metals in the selected commercially important edible fish species gray mullet (Mugil cephalus) from Negombo estuary

Consumption of fish contaminated with non essential heavy metals such as Pb, Hg and Cd metals which exceed the required limits pose a risk to human health. Bioaccumulations of heavy metals in fish depend on several factors such as increased levels of industrial pollution and domestic solid waste dumping in the estuary. Based on the pollution inputs into the estuary, it is considered that different localities within the estuary are polluted at different rates.The objectives of this study were to determine the non essential heavy metals concentration in fish tissues and assess the seasonal variations in the ecosystem. For this study, fish tissue samples were collected from nine sampling locations along the North (n =3), South (n=2), West (n=2), and East (n=2) parts of the estuary for a period of one year from January to December 2014. Fish tissue heavy metals levels were analyzed employing standard methods. Results revealed that the average concentrations (mg/kg) varied from Pb 0 to 0.15 ± 0.06, Cd 0.35 ± 0.16 to 1.04 ± 0.28 and Hg 0.0005 ± 0.0004 to 0.05 ± 0.046 mg/kg respectively. The detected levels were below the maximum permissible limits for hazardous substances in fish and fishery products for recommendation of FAO. The detected lead, mercury and cadmium contents in fish tissue were below the standard limits defined for each element < 0.5 mg/kg < 0.05 mg/kg and < 0.05 mg/kg respectively. Significant differences (P < 0.05) were observed for Pb and Hg depending on fish tissues. The levels of Pb and Hg metals in muscle tissue were lower than the standard limit for FAO. The value obtained on Cd 1.04 ± 0.28 mg/kg concentration was much higher than the permissible threshold limit observed in the north, south, east and west regions. The most prominent increases in Pb and Cd metal concentrations in fish tissue were found during the October, November and December study of 2014, which corresponded to peak periods from October, November and December which apparently coincided with the second inter monsoon of the island respectively

The composition of heavy molecular ions inside the ionopause of Comet Halley

The RPA2-PICCA instrument aboard the Giotto spacecraft obtained 10-210 amu mass spectral of cold thermal molecular ions in the coma of Comet Halley. The dissociation products of the long chain formaldehyde polymer polyoxymethylene (POM) have recently been proposed as the dominant complex molecules in the coma of Comet Halley; however, POM alone cannot account for all of the features of the high resolution spectrum. An important component of the dust at Comet Halley is particles highly enriched in carbon, hydrogen, oxygen, and nitrogen relative to the composition of carbonaceous chondrites. Since this dust could be a source for the heavy molecules observed by PICCA, a search was conducted for other chemical species by determining all the molecules with mass between 20 and 120 amu which can be made from the relatively abundant C, H, O, and N, without regard to chemical structure

Performance-enhancement of phase change materials for energy conservation in the built environment : a state-of-the-art review

Energy conservation has become a critical issue in the world today as strong economic growth is unfeasible without a sustainable strategy of energy conservation. Apart from long-term environmental impact, a well-managed strategy for energy consumption even results in improvement of the financial performance in the short term. Phase change materials (PCMs) with its capacity of storing thermal energy as latent heat is a viable approach of the utilization of solar heat, a green source of energy, and the optimization of energy consumption in buildings. However, the obstacle that prevents PCMs from being applied widely in practice comes from its poor performance in terms of heat transfer and shape stabilization. This article, therefore, presents a critical review of PCM and effective methods to boost its performance in terms of shape stabilization and transient heat transfer

Framework for analysis of demolition supply chain to optimize use of recycled concrete aggregate (RCA) and recycled aggregate (RA)

The paper discusses the factors that affect the recycling rate of recycled aggregates (RA) and recycled concrete aggregates (RCA) derived from demolition waste of reinforced concrete buildings. The recycling rate for construction and demolition waste presently stand at 57% in Australia, where countries such as Japan has achieved 98% recycling rates for demolition waste. A framework is proposed to investigate demolition waste management supply chain as a whole and to critically analyse and investigate the factors affecting the recycling rate of concrete and fines to produce RA and RCA from demolition waste. The factors affecting the recycling rate of concrete and fines across the waste supply chain are categorised into technical, economic and regulatory and policy related factors. The framework proposed is to analyse the inter-relationships between these factors

Numerical simulation of impact and penetration of ogvial shaped projectiles through steel plate structures

There is an urgent need to develop light-weight protective structures with a sufficient protection to prevent the damage occurring during extreme loading events such as blast and ballistic impacts. This study is a part of ongoing research to develop light weight amour materials which can sustain under those severe conditions. Numerical modelling with explicit finite element code LS-DYNA has performed with realistic geometries. Ballistic protection class BR7 in European norm EN 1063 considered, thus penetration of different shaped projectiles through thick steel plates was examined. Since the geometries and materials of the projectiles have a very significant influence on the outcome of this research detail modelling of the projectiles was performed. For the purpose of this paper, perforation mechanism of 7.62mm APM2 bullet through 6mm thick Weldox 460E high strength structural steel plate was examined. Largrangian methods combined with Johnson-Cook material model available in the LS-DYNA were used for the numerical simulations. Finally the ballistic limit curve for the 6mm thick Weldox 460E plate perforated by APM2 bullet was obtained. Results were compared with the analytical models

The Intellectual Property Implications of the Development of Industrial 3D Printing

This commissioned project/report for the European Commission explores the IP Implications of the Development of Industrial 3D Printing from a European perspective. The report aims to enhance the European business sector and foster innovation. Through a legal and empirical analysis, involving qualitative data drawn from interviews with 41 industry stakeholders, the findings from the project demonstrates the areas which needed to be addressed – and resolved. Being the first large-scale empirical project of its kind, the report delves into the heart of EU IP regulation and makes policy recommendations for all aspects of IP whilst also providing recommendations for industry. The report was authored by a team of national and international researchers including a team of academics and practitioners and consisted of Lead Author, Dinusha Mendis together with partners from UK (Julie Robson, Phill Dickinson), Austria (Maria del Carmen Calatrava-Moreno and Alfred Radeur); Finland (Rosa Ballardini); and Germany (Jan Nordemann and Hans Brorsen)