An empirical analysis of nitrogen pressure effect on grain size development of nanostructured ternary nitride coatings

An empirical relationship between the grain diameter of ternary nitride coatings and trhe nitrogen deposition pressure was formulated in the present study. A linear relationship was established between the reciprocals of the square roots of the rgain diameter of the coatings and the nitrogen deposition pressure. It was further confirmed that the equation parameter, md of the empirical relationship was linearly proportional to the primary yield of the coating materials. With defined discharge conditions and sputter characteristics of the larget materials, the values of md for diffeent coatings can be calculated and te rgain size of the coating structure at different nitrogen deposition pressures can be determined

Effects of animal size and nutritional status on the RNA/DNA ratio in different tissues of the green-lipped mussel Perna viridis

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High temperature behaviour of magnetron sputtered nanocrystalline titanium aluminium nitride coatings

This paper is to study the thermal stability of nanocrystalline ternary nitride coatings at elevated temperatures. Nanocrystalline titanium aluminium nitride coatings were produced by reactive magnetron co-sputtering on glass substrates and AISI H13 tool steel substrates with nitrogen pressures of 0.4 and 0.65 mTorr (0.053 and 0.086 Pa) respectively. Heat treatment was applied to the coatings at temperatures up to 1000C. It was found that an unexpected grain refinement occurred in the coatings deposited at 0.4 mTorr nitrogen pressure after the heat treatment. a stronger development of TiN(TiAIN (200) component was also evident at temperatures above 800C. With a finer and densified grain struicture, the hardness of the coatings increased substantially from ~1700 to 2300HV

Balancing the peak and off-peak travel demands towards cemeteries and columbaria

Special events attract extraordinarily high travel demands within a relative short period of time. Managing those travel demands is more critical than that for normal commuting trips since the high demands usually induce more severe impacts to local traffic. The impacts vary amongst different special events due to the difference in their natures. Unlike most of the special events like concerts or football matches that have a fixed date and time, the visitors to grave-sweeping could choose their available date and time to visit around the festival dates. Therefore, the policy measures suggested to manage the demand for other special events in the previous researches ...postprin

X-ray photoelectron spectroscopy analysis of oxide formation on 8150 aluminium foils

It is known that an enrichment of metallic elements in the oxide layer of aluminium foils may significantly affect their surface properties. Elemental compositions at various depths of the newly developed 8150 aluminium foil were determined by x-ray photoelectron spectroscopy for selected heat treatment conditions. © Institute of Materials Engineering Australasia Ltd

Measurement of fracture toughness of hydrided Zircaloy - 4

Zircaloy-4 is a zirconium alloy that will be used for construction of many of the core components in the replacement research reactor at Lucas Heights. The fracture toughness of the alloy and its radiation-induced reduction over the 40 year planned life of the reactor is an important mechanical property for this application. This study aims to simulate the radiation-induced reduction in fracture toughness by hydriding Zircaloy-4. A range of fracture toughnesses is required to calibrate the sub-size Charpy and small punch (SP) surveillance specimens that will be irradiated over the life of the reactor against standard J1C fracture toughness specimens. Pieces of Zircaloy-4 plate were hydrided in a vessel at a temperature of 520°C, at different pressures for either 10 or 22 hours. Final hydrogen concentrations between 25 wt% ppm and 380 wt% ppm hydrogen were obtained under gaseous atmosphere. The fracture toughness of the hydrided Zircaloy-4 was assessed using sub-size 2.5 mm-thick Charpy, three-point bend J1C and SP tests. The results were correlated to determine the relationship between the J-integral fracture toughness, Charpy impact energy and equivalent fracture strain (εqf) from the SP tests. It was found that as hydrogen concentration and hydride formation increased, the fracture toughness of the alloy generally decreased. The results show there to be a useful relationship between fracture toughness and εqf measured for the SP tests. © Institute of Materials Engineering Australasia Ltd - Materials Forum Volume 27 - Published 2004

EBSD investigations of Equal Channel Angular Extruded copper

Development of nano- and submicron-structured materials has attracted significant research interest in the last ten years [1, 2]. Most recently, an innovative technology called the Equal Channel Angular Extrusion (ECAE) process has demonstrated its capability of producing nano- and submicronstructured metallic alloys with substantial strength improvement [3-8]. ECAE adopts the principle of mechanical attrition and imposes very heavy shear deformation on bulk materials without causing major dimensional changes of the extruded products [3]. It has been suggested that this technology has great advantages over the conventional mechanical attrition of ball milling because it can produce large sized samples free of any residual porosity

Mixed logit approach to modelling arrival time choice behaviour of cemetery and columbarium visitors during grave-sweeping festivals

Special events attract extraordinarily high travel demands over a relatively short time. Managing the travel demand for special events is more difficult than for normal commuting trips. Grave-sweeping is a special event that is popular in Asia, especially in Chinese societies. In Hong Kong, many people visit cemeteries and columbaria around the two traditional festivals, causing overcrowding at the sites and congestion on the access roads. To mitigate the adverse traffic effects, the police usually implement temporary traffic management measures to control the number of visitors accessing the sites. However, these measures often ignore visitors’ arrival time preferences and hence their effectiveness is questionable. This study models and analyses the arrival time preferences of cemetery and columbarium visitors under various transport mode scenarios. The model development is based on 3128 choice decisions collected from 782 respondents. A mixed logit model is calibrated to investigate the potential taste heterogeneity of the respondents, and a likelihood ratio test demonstrates that the model is superior to a standard multinomial logit model and provides a better fit to the survey data. The model results indicate that in-vehicle travel time, total waiting and walking time, and the provision and travel fare of feeder services are significant factors influencing cemetery and columbarium visitors’ arrival time choices. The effects of socio-economic factors are also examined and discussed. Based on the model results, recommendations are provided for managing the travel demand to cemeteries and columbaria at peak and off-peak hours on or around festival days.postprin

X-ray mapping of metallic elements in roll bonded metal laminates

Advanced metal laminates have experienced rapid development in functional engineering applications. In this study, copper/aluminium metal laminates were produced by the roll bonding technique at 430°C with a critical 40% rolling reduction and sintering treatment was applied at 450°C. Interface development of the samples was examined using scanning electron microscopy and the distribution of the metallic elements and the subsequent chemical phase formation in the interfacial region was investigated by x-ray mapping. It was found that movement of the copper atoms occurred at a faster diffusion rate into the aluminium region and resulted in a shift of the interface boundary. Growth rate of the interface was determined and its relationship with sintering time was formulated. Development of the metallic phases in the interfacial area of the metal laminates was observed and determined. © Institute of Materials Engineering Australasia Ltd