A study of secondary instabilities in postbuckling composite aerostructures

A number of experimental studies have shown that postbuckling stiffened composite panels, loaded in uniaxial compression, may undergo secondary instabilities, characterised by an abrupt change in the buckled mode-shape of the skin between the supporting stiffeners. In this study high-speed digital speckle photogrammetry is used to gain further insight into an I-stiffened panel's response during this transient phase. This energy-dissipating phenomenon will be shown to be able to cause catastrophic structural failure in vulnerable structures. It is therefore imperative that an accurate and reliable methodology is available to predict this phenomenon. The shortcomings of current non-linear implicit solution schemes, found in most commercially-available finite element codes, are discussed. A robust and efficient strategy, which utilises an automated quasi-, static/pseudo-transient hybrid scheme, is presented in this paper and validated using a number of experimental tests. This approach is shown to be able to predict mode-jumping with good accuracy.

Analysis of Betaine and Choline Contents of Aleurone, Bran, and Flour Fractions of Wheat (Triticum aestivum L.) Using 1H Nuclear Magnetic Resonance (NMR) Spectroscopy

In conventional milling, the aleurone layer is combined with the bran fraction. Studies indicate that the bran fraction of wheat contains the majority of the phytonutrients betaine and choline, with relatively minor concentrations in the refined flour. This present study suggests that the wheat aleurone layer (Triticum aestivum L. cv. Tiger) contains the greatest concentration of both betaine and choline (1553.44 and 209.80 mg/100 g of sample, respectively). The bran fraction contained 866.94 and 101.95 mg/100 g of sample of betaine and choline, respectively, while the flour fraction contained 23.30 mg/100 g of sample (betaine) and 28.0 mg/100 g of sample (choline). The betaine content for
the bran was lower, and the choline content was higher compared to previous studies, although it is known that there is large variation in betaine and choline contents between wheat cultivars. The ratio of betaine/choline in the aleurone fraction was approximately 7:1; in the bran, the ratio was approximately 8:1; and in the flour fraction, the ratio was approximately 1:1. The study further
emphasizes the superior phytonutrient composition of the aleurone layer.
INTRODUCTION
Wheat is a valuable source of betaine, choline (1, 2), B
vitamins, vitamin E, and a number of minerals, including iron,
zinc, magnesium, and phosphorus (3). Epidemiological studies
indicate that whole-grain consumption is protective against
several chronic diseases (4-12). It has not been fully elucidated
how whole-grain cereals or specific fractions (13) exert their
protective effect, but it is thought to be due to their content of
several nutrients associated with the reduced risk of disease.
Conventionally, whole grain is separated during milling into
bran, germ, and flour (14). The nutrient composition of these
fractions differ markedly; refined wheat flour contains approximately
50% less vitamins and minerals than whole-grain
flour (

Review of the Viability Audit process: analysis of primary school data

This paper provides an analysis of the primary school data provided in the viability audit report published in February 2012. The Viability Audit has been led by the Education and Library Boards, working in close conjunction with CCMS. The Area Planning process was led by the Department of Education, working with the Education and Library Boards and CCMS. Draft area planning reports, and revised reports following consultation, have been published for post primary schools; draft area planning reports for primary schools have been published and are not out for consultation. It should be noted that the draft area plan reports for primary schools used updated data available to the ELBs so some of the patterns will differ slightly from those reported in the analysis below.