Hot stage TEM investigations of dislocation climb in NiAl

Hot stage was used to investigate dislocation loop formation and growth at climb sources in Al rich alloys of β-NiAl. The loops grew by absorbing vacancies retained during cooling of the samples. The growth rate was dependent on the speed of cooling and anomalously high growth of loops occurred near the foil surfaces. The loop shapes were nearly square as a result of loop growth by a jog mechanism. Estimates of the vacancy concentration contained in the loops after growth demonstrated that nearly all thermal vacancies can be retained in NiAl.     

Leukocyte image analysis in the diff3 system

The diff3 System uses image processing and pattern recognition techniques to automatically analyze normal and abnormal white blood cells in a blood smear. The system consists of a spinner which creates a monolayer of cells on a glass slide, a stainer utilizing Wright's stain, the reagents to support the spinner and stainer, and an analyzer for automatic slide handling, analysis and report generation. The analyzer incorporates a wide range of image processing functions, including the generation and storage of gray scale image data, whole-field and partial-field image histogramming, and high-order binary image texture analysis and image transformation using the Golay processor (GLOPR). This paper describes the manner in which these hardware capabilities are used for white cell acquisition, scene segmentation and feature analysis. It concludes with some examples of texture extraction which illustrate the power of the Golay processor as a tool for image analysis.     

Starter cultures employed in the manufacture of biofermented milks

The market for fermented milks is expanding as more consumers become interested in the possible health aspects of the product. This paper reviews the types of bacteria that are currently being used in the manufacture of biofermented milks. The requirements of a starter culture in terms of ability to ferment milk to a stable product and to provide the necessary sensory properties for consumer demands are outlined. The paper also discusses and highlights some of the problems encountered in developing milks for the health market using probiotic organisms such as Lactobacillus acidophilus and species of Bifidobacterium.     

Effects of income and urban form on urban NO2: global evidence from satellites

Urban air pollution is among the top 15 causes of death and disease worldwide, and a problem of growing importance with a majority of the global population living in cities. A important question for sustainable development is to what extent urban design can improve or degrade the environment and public health. We investigate relationships between satellite-derived estimates of nitrogen dioxide concentration (NO(2), a key component of urban air pollution) and urban form for 83 cities globally. We find a parsimonious yet powerful relationship (model R(2) = 0.63), using as predictors population, income, urban contiguity, and meteorology. Cities with highly contiguous built-up areas have, on average, lower urban NO(2) concentrations (a one standard deviation increase in contiguity is associated with a 24% decrease in average NO(2) concentration). More-populous cities tend to have worse air quality, but the increase in NO(2) associated with a population increase of 10% may be offset by a moderate increase (4%) in urban contiguity. Urban circularity ("compactness") is not a statistically significant predictor of NO(2) concentration. Although many factors contribute to urban air pollution, our findings suggest that antileapfrogging policies may improve air quality. We find that urban NO(2) levels vary nonlinearly with income (Gross Domestic Product), following an "environmental Kuznets curve"; we estimate that if high-income countries followed urban pollution-per-income trends observed for low-income countries, NO(2) concentrations in high-income cities would be ～10× larger than observed levels.     

Oxidative stability of mahi mahi red muscle dipped in tilapia protein hydrolysates

The oxidative stability of mahi mahi red muscle dipped in tilapia protein hydrolysates was evaluated. Alkali solubilised tilapia protein isolate was hydrolysed using Flavourzyme to 13% degree of hydrolysis. Whole tilapia protein hydrolysate and ultrafiltered fraction <10 kDa were used as dip solutions. Mahi mahi red muscle was dip treated either for 2 or 4 min and stored at 4 °C. Lipid hydroperoxides (PV), thiobarbituric acid reactive substances (TBARS) and a∗ value were measured at regular intervals. Results showed that dip treatments significantly decreased (p < 0.05) the formation of PV and TBARS over 90 h storage time. There was no significant (p > 0.05) difference between WH and <10 kDa fractions, and between 2 and 4 min treatments. Red colour of treated samples measured as a∗ value decreased with storage time, but was not significantly different from the control. It could be concluded that dip treatment for 2 min in whole tilapia protein hydrolysate may be used as a potential antioxidant treatment for improving oxidative stability of fish fillets.     

Body dissatisfaction among middle-aged and older women

With the growing pervasiveness of mass media, individuals of all ages and both sexes are bombarded with images that glorify youthfulness, messages that tie self-worth to thinness, and products that promise youth and beauty forever. Aging women are vulnerable to these societal messages and experience strong pressures to maintain their youth and thinness. As the physiological changes that accompany normal aging move these women farther from the "ideal" image, body dissatisfaction may increase. These women are confronted with the impossible task of trying to defy the natural process of aging through a variety of means, including fashion, cosmetics, selective surgeries, and personal food choices. The resulting body image issues, weight preoccupation, and eating disturbances can lead to voluntary food restriction, depression, social withdrawal, lower self-esteem, and disordered eating, all of which can have a negative impact on quality of life and nutritional status. In this review we explore existing research on body dissatisfaction among middle-aged (30 to 60) and older (over 60) women, discuss the prevalence of body dissatisfaction, its predisposing risk factors, and the resulting eating and body maintenance behaviours, and examine implications for dietetic practice.     

Enhanced Fracture Toughness in Layered Microcomposites of Ce-ZrO2 and Al2O3

Laminar composites, containing layers of Ce-ZrO₂ and either Al₂O₃ or a mixture of Al₂O₃ and Ce-ZrO₂, have been fabricated using a colloidal method that allowed formation of layers with thicknesses as small as 10 μm. Strong interactions between these layers and the martensitic transformation zones surrounding cracks and indentations have been observed. In both cases, the transformation zones spread along the region adjacent to the layer, resulting in an increased fracture toughness. The enhanced fracture toughness was observed for cracks growing parallel to the layers as well as for those that were oriented normal to the layers.     

Direct Measurement of Transformation Zone Strains in Toughened Zirconia

Residual strains responsible for crack tip shielding have been measured within transformation zones surrounding cracks in Mg-PSZ. Two techniques were used for strain measurement: moiré interferometry and high-resolution image matching. Both methods provide maps of differential in-plane displacements within the specimen surface intersected by the crack, the latter method with the higher resolution. The results are compared with finite-element analysis to assess surface relaxation effects, and the measured strains are used to evaluate the crack tip shielding stress intensity factor. Calculations based on the assumption that the unconstrained transformation strain is hydrostatic dilatation yielded results that were significantly smaller than the measured toughness increases.     

Nuclear Magnetic Resonance Studies of Silicon Carbide Polytypes

The ²⁹Si MAS NMR spectra of the 2H, 4H, 6H, and 3C polytypes of silicon carbide are presented. An attempt is made to correlate differences in the chemical shifts with local atomic environment. The results of the analysis of the spectra of pure polytypes are used as a basic for the interpretation of the spectra of mixed polytypes and a discussion of the crystallinity and impurity levels of different samples. Carbon-13 chemical shifts obtained from spectra of the same polytypes are also tabulated.