Effect of grain size on deformation twinning in a magnesium alloy and commercial purity titanium

This data collection contains several optical microstructure images, EBSD maps and stress-strain curves. The research involves collecting data from samples with different grain sizes at several values of plastic strains to measure some important twinning parameters such as twin volume fraction and number of twins per grain. The aim of this study is to investigate the effect of grain size on deformation twinning behaviour in two hcp metals i.e. commercial purity titanium and AZ31 magnesium alloy.

Influence of grain size and training temperature on strain of polycrystalline Ni50Mn29Ga21 samples

The alloy Ni-Mn-Ga aroused great interest for application as a magnetic shape memory (MSM) material. This effect is caused by reorientation of twin variants by an external magnetic field. So far, most of the experiments were concentrated on single crystals. But, the MSM effect can also be realised in polycrystals which can be prepared much more efficiently. Here, polycrystalline samples were prepared by directional solidification with a <100> fibre texture of the high temperature cubic austenitic phase parallel to the heat flow. Afterwards, a heat treatment was applied for chemical homogenisation and stress relaxation in the austenitic state. Then the samples were heated up to the austenitic state and cooled down under load. The microstructure was analysed by Electron Back Scatter Diffraction (EBSD) before and after that treatment. Mechanical training at room temperature and 40°C was tracked by recording stress-strain curves. By increasing the number of training cycles the strain also increases. The influence of different training temperatures was investigated on samples with different grain sizes.

Adaptive patch size determination for patch-based image completion

Patch-based image completion proceeds by iteratively filling the target (unknown) region by the best matching patches in the source image. In most existing such algorithms, the size of the patches is either fixed and specified by a default number or simply chosen to be inversely proportional to the spatial frequency. However, it is noted that the patch size affects how well the filled patch captures the local characteristics of the source image and thus the final completion accuracy. Thus in this paper we propose a new method to compute appropriate patch sizes for image completion to improve its performance. In particular, we formulate the patch size determination as an optimization problem that minimizes an objective function involving image gradients and distinct and homogenous features. Experimental results show that our method can provide a significant enhancement to patch-based image completion algorithms.

The role of cultural values and religion on views of body size and eating practices among adolescents from Fiji, Tonga and Australia

Objectives This study investigated cultural values related to body image and eating practices in Western and non-Western societies.

Design and Methods In total, 628 Fijian, 463 Indo-Fijian, 598 Tongan, and 534 Australian adolescents completed measures of cultural values and religious influences in relation to the ideal body and eating practices.

Results Fijian and Tongan adolescents were more likely to value a large body. Religious influences were most strongly associated with eating practices for Fijians, Indo-Fijians, and Tongans.

Conclusions The findings support the role of religion in transmitting cultural values regarding eating practices in Pacific Island communities.

Statement of contribution
What is already known on this subject? Previous research has demonstrated that sociocultural factors shape body image and eating behaviours. Most of this research has been conducted in Western countries.

What does this study add? The current study identifies the role of cultural values and religious influences on body image and eating behaviours in a number of different cultural groups. This is the first study to use the same methodology to explore these relationships across Western and Pacific Island communities.

Clutch size for Mediterranean loggerhead turtles (Caretta caretta)

We investigated the number of eggs laid and the total clutch volume for loggerhead turtles (Caretta caretta L.) nesting on the Greek island of Cephalonia (38° 09′ N, 20° 33′ E) during 1990. Both the number of eggs laid and clutch volume were positively related to female body size, and the mean explained variation for these relationships (36·6% and 37·7%, respectively) were not significantly different. Clutch volume decreased as the season progressed because individuals laid successively smaller clutches. The inter-nesting interval (range 15–19 days) did not significantly influence the number of eggs laid or clutch volume. For individuals seen laying more than once, female size in combination with the number of a clutch in relation to all the clutches observed for that individual, together explained 65·5% of the variation in clutch volume.

Reproductive investment and optimum clutch size of Loggerhead Sea Turtles (Caretta caretta)

(1) Data for loggerhead turtles (Caretta caretta L.) nesting on the Greek island of Cephalonia were used to develop a model which predicted the optimum clutch size. (2) There was a positive linear relationship between the number of clutches into which eggs could be divided and the total time spent by a nesting turtle on the beach, and hence a negative relationship between the time invested on the beach per egg and clutch size. (3) A previous study indicated that energy expenditure for nesting turtles on land is very high, so there may be a selective pressure to maximize clutch size in order to minimize the energy expended per egg laid. As there appeared to be no counterselective pressures favouring small clutches, clutch size should be constrained by a female's egg-carryingc apacity,w hich in turn could be expected to be related to her body size. Hence, a positive relationship between clutch size and body size was predicted, and was found in the population under study.

Size distribution and volume fraction of T1 phase precipitates from TEM images: Direct measurements and related correction

Transmission Electron Microscopy (TEM) can be used to measure the size distribution and volume fraction of fine scale precipitates in metallic systems. However, such measurements suffer from a number of artefacts that need to be accounted for, related to the finite thickness of the TEM foil and to the projected observation in two dimensions of the microstructure. We present a correction procedure to describe the 3D distribution of disc-like particles and apply this method to the plate-like T1 precipitates in an Al-Li-Cu alloy in two ageing conditions showing different particle morphologies. The precipitates were imaged in a High-Angular Annular Dark Field Microscope (HAADF-STEM). The corrected size distribution is further used to determine the precipitate volume fraction. Atom probe tomography (APT) is finally utilised as an alternative way to measure the precipitate volume fraction and test the validity of the electron microscopy results.