Determination of local material properties of OSB sample by coupling advanced imaging techniques and morphology-based FEM simulation

This is the publisher’s final pdf. The published article is copyrighted by Walter de Gruyter & Co. and can be found at: http://www.degruyter.com/.The goal was to determine local mechanical properties inside of oriented strand board (OSB) based on a realistic morphology-based finite element (FE) model and data acquired from a physical test performed on the same material. The spatial information and local grayscale intensity from CT-scans obtained from small OSB sample was transformed into a 2D regular morphology-based FE mesh with corresponding material properties. The model was then used to simulate the actual compression test performed on the specimen using simplified boundary conditions. The simulated strain fields from the model were compared with the actual strain field measured on the specimen surface during the compression test by means of a full-field optical method, named digital image correlation (DIC). Finally, the original set of material properties was adjusted by an iterative procedure to minimize the difference between the simulated and the measured strain data. The results show that the developed procedure is useful to find local material properties as well as for morphological modeling without the need of segmentation of the image data. The achieved results serve as a prerequisite for full 3D analyses of the complex materials

Quay voices in Glasgow museums : an oral history of Glasgow dock workers

Notes on oral history project commissioned by Glasgow museums about Glasgow dock workers

Introduction de jachères florales en zones de grandes cultures : comment mieux concilier agriculture, biodiversité et apiculture ?

Les abeilles au sens large représentent plus de 20 000 espèces dans le monde. Or, un déclin des populations d'abeilles a été récemment observé en Europe (Biesmeijer et al., 2006 ; Rasmont et al., 2006). Il pose le problème du risque de disparition de ces insectes auxiliaires et de sa répercussion sur les activités humaines qui leur sont liées comme l’apiculture, la production de fruits, de légumes, de semences. La FAO (Nations-Unies) a lancé, en 1996, un cri d’alarme à l’attention de tous les gouvernements pour sauvegarder cette faune d’auxiliaires. Les causes possibles de ce déclin sont multiples (Kearns et al., 1998 ; Ghazoul, 2005). Les plus citées concernent la destruction et la fragmentation de l’habitat des abeilles (Richards, 2001 ; Steffan-Dewenter et al., 2006) et l'impact des produits phytopharmaceutiques (Kevan, 1975 ; Johansen et al., 1983 ; Taséi, 1996 ; Haskell et McEwen, 1998)

Sensitivity of Recalibrated Continuous Glucose Monitor Data

Continuous glucose monitors (CGMs) are increasingly used in research settings to examine glucose metabolism in newborn babies. Accuracy of these devices depends on calibration blood glucose (BG) measurements entered into the CGM device. The potential impact of variations in timing and accuracy of reference calibration measurements on CGM device output were assessed

Building a Model of Collaboration Between Historically Black and Historically White Universities

Despite increases over the last two decades in the number of degrees awarded to students from underrepresented groups in science, technology, engineering, and mathematics (STEM) disciplines, enhancing diversity in these disciplines remains a challenge. This article describes a strategic approach to this challenge—the development of a collaborative partnership between two universities: the historically Black Elizabeth City State University and the historically White University of New Hampshire. The partnership, a type of learning organization built on three mutually agreed upon principles, strives to enhance opportunities for underrepresented students to pursue careers in the STEM disciplines. This article further describes six promising practices that framed the partnership, which resulted in the submission of nine proposals to federal agencies and the funding of four grants that led to the implementation, research, learning, and evaluation that followed

Experimental Investigation of the Operating Point of a 1-kW ORC System

The organic Rankine cycle (ORC) is a promising technology for the conversion of waste heat from industrial processes as well as heat from renewable sources. Many efforts have been channeled towards maximizing the thermodynamic potential of ORC systems through the selection of working fluids and the optimal choice of operating parameters with the aim of improving overall system designs, and the selection and further development of key components. Nevertheless, experimental work has typically lagged behind modelling efforts. In this paper, we present results from tests on a small-scale (1 kWel) ORC engine consisting of a rotary-vane pump, a brazed-plate evaporator and a brazed-plate condenser, a scroll expander with a built-in volume ratio of 3.5, and using R245fa as the working fluid. An electric oil-heater acted as the heat source, providing hot oil at temperatures in the range 120-140°C. The frequency of the expander was not imposed by an inverter or the electricity grid but depended directly on the attached generator load; both the electrical load on the generator and the pump rotational speed were varied in order to investigate the performance of the system. Based on the generated data, this paper explores the relationship between the operating conditions of the ORC engine and changes in the heat-source temperature, pump and expander speeds leading to working fluid flow rates between 0.0088 kg/s and 0.0337 kg/s, from which performance maps are derived. The experimental data is, in turn, used to assess the performance of both the individual components and of the system, with the help of an exergy analysis. In particular, the exergy analysis indicates that the expander accounts for the second highest loss in the system. Analysis of the results suggests that increased heat-source temperatures, working-fluid flow rates, higher pressure ratios and larger generator loads improve the overall cycle efficiency. Specifically, a 46% increase in pressure ratio from 2.4 to 4.4 allowed a 3-fold electrical power output increase from 180 W to 550 W, and an increase in the thermal efficiency of the ORC engine from 1 to 4%. Beyond reporting on important lessons learned in improving the performance of the system under consideration, comparisons will be shown for making proper choices with respect to the interplay between heat-source temperature, generator load, and pump speed in an ORC system

Locating the place and meaning of physical activity in the lives of young people from low-income, lone-parent families

Background: In the United Kingdom (UK), it is predicted that economic cuts and a subsequent increase in child poverty will affect those already on the lowest incomes and, in particular, those living in lone-parent families. As a result, the informal pedagogic encounters within the family that contribute to the development of physical activity-related values, beliefs and dispositions from a very early age will be affected. Therefore, it is vital that we gain an understanding of the place and meaning of physical activity in the lives of young people, as well as the informal pedagogic practices and the socio-cultural forces that influence individual agency. Purpose: Based on Bourdieu's key concepts, this paper explores the interplay of structural conditions and personal agency with regard to physical activity in the lives of young people from low-income, lone-parent families. Methods: This study reports on the voices of 24 participants (aged 11–14) from low-income, lone-parent families in the West Midlands, UK. These participants were engaged in paired, semi-structured interviews to explore issues of personal agency by listening to how they reported on their present lives, past experiences and future possibilities with regard to physical activity. All corresponding interview data were analysed using analytical induction. Findings: This paper suggests that young people exhibited diminished desires to engage in activity due to structural constraints of time, parents' work commitments and a lack of transport that resulted in engagement in sedentary alternatives. Informal pedagogic practices within these families were restricted due to the associated structural conditions of living in a lone-parent family. As such, young people's choice to not seek out physical activities when at home reflected a ‘taste for necessity’ resulting from a lack of cultural and economic capital, placing restrictions on physical activity opportunities that stemmed from their family doxa. Conclusions: To succeed in fostering dispositions and opportunities to participate in physical activity, we must engage with young people from low-income, lone-parent families from an early age. Certainly though, further consideration of the informal pedagogic practices within, and the demands on, lone-parent families is required when designing any intervention or policy that seeks to enhance their current circumstances and provide opportunities for engagement in a variety of contexts

Recombinant human activated protein C improves endotoxemia-induced endothelial dysfunction: a blood-free model in isolated mouse arteries

Recombinant human activated protein C (rhAPC) is one of the treatment panels for improving vascular dysfunction in septic patients. In a previous study, we reported that rhAPC treatment in rat endotoxemia improved vascular reactivity, although the mechanisms involved are still under debate. In the present study, we hypothesized that rhAPC may improve arterial dysfunction through its nonanticoagulant properties. Ten hours after injection of LPS in mice (50 mg/kg ip), aortic rings and mesenteric arteries were isolated and incubated with or without rhAPC for 12 h. Aortic rings were mounted in a myograph, after which arterial contractility and endothelium-dependent relaxation were measured in the presence or absence of nitric oxide synthase or cyclooxygenase inhibitors. Flow (shear stress)-mediated dilation with or without the above inhibitors was also measured in mesenteric resistance arteries. Protein expression was assessed by Western blotting. Lipopolysaccharide (LPS) reduced aortic contractility to KCl and phenylephrine as well as dilation to acetylcholine. LPS also reduced flow-mediated dilation in mesenteric arteries. In rhAPC-treated aorta and mesenteric arteries, contractility and endothelial responsiveness to vasodilator drug and shear stress were improved. rhAPC treatment also improved LPS-induced endothelial dysfunction; this effect was associated with an increase in the phosphorylated form of endothelial nitric oxide synthase and protein kinase B as well as cyclooxygenase vasodilatory pathways, thus suggesting that these pathways, together with the decrease in nuclear factor-κB activation and inducible nitric oxide synthase expression in the vascular wall, are implicated in the endothelial effect of rhAPC. In conclusion, ex vivo application of rhAPC improves arterial contractility and endothelial dysfunction resulting from endotoxemia in mice. This finding provides important insights into the mechanism underlying rhAPC-induced improvements on arterial dysfunction during septic shock