Simulation of the Unsteady Gas Flow through a Three-way Automotive Catalyst

This paper describes a model of a 1.8-litre four-cylinder four-stroke gasoline engine fitted with a close-coupled three-way catalyst (TWC). Designed to meet EURO 3 emissions standards, the engine includes some advanced emission control features in addition to the TWC, namely: variable valve timing (VVT), swirl control plates, and exhaust gas recirculation (EGR). Gas flow is treated as one-dimensional (1D) and unsteady in the engine ducting and in the catalyst. Reflection and transmission of pressure waves at the boundaries of the catalyst monolith are modelled. In-cylinder combustion is represented by a two-zone burn model with dissociation and reaction kinetics. A single Wiebe analysis of measured in-cylinder pressure data is used to determine the mass fraction burned as a function of crank angle (CA) at each engine speed. Measured data from steady-state dynamometer tests are presented for operation at wide open throttle (WOT) over a range of engine speeds. These results include CA-resolved traces of pressure at various locations throughout the engine together with cycle-averaged traces of gas composition entering the catalyst as indicated by a fast-response emissions analyser. Simulated engine performance and pressure wave action throughout the engine are well validated by the measured data.

Opacity in the upper atmosphere of AU Mic

In this paper we investigate the validity of the optically thin assumption in the transition region of the late-type star AU Mic. We use Far-Ultraviolet Spectroscopic Explorer (FUSE) observations of the C III multiplet and O VI resonance lines, hence yielding information at two different levels within the atmosphere. Significant deviations from the optically thin fluxes are found for C III in both quiescent and flare spectra, where only 60% of the flux is actually observed. This could explain the apparent deviation of C III observed in emission measure distributions. We utilize escape probabilities for both homogeneous and inhomogeneous geometries and calculate optical depths as high as 10 for the C III 1175.71 Angstrom component of the multiplet. Using a lower limit to the electron density (10(11) cm(-3))we derive an effective thickness of

Dietary glycaemic index, glycaemic load and breast cancer risk: a systematic review and meta-analysis

This systematic review aimed to examine if an association exists between dietary glycaemic index (GI) and glycaemic load (GL) intake and breast cancer risk. A systematic search was conducted in Medline and Embase and identified 14 relevant studies up to May 2008. Adjusted relative risk estimates comparing breast cancer risk for the highest versus the lowest category of GI/GL intake were extracted from relevant studies and combined in meta-analyses using a random-effects model. Combined estimates from six cohort studies show non-significant increased breast cancer risks for premenopausal women (relative risk (RR) 1.14, 95% CI 0.95-1.38) and postmenopausal women (RR 1.11, 95% CI 0.99-1.25) consuming the highest versus the lowest category of GI intake. Evidence of heterogeneity hindered analyses of GL and premenopausal risk, although most studies did not observe any significant association. Pooled cohort study results indicated no association between postmenopausal risk and GL intake (RR 1.03, 95% CI 0.94-1.12). Our findings do not provide strong support of an association between dietary GI and GL and breast cancer risk. © 2008 Cancer Research UK.


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Selection of an analytical method for evaluating bovine serum albumin concentrations in pharmaceutical polymeric formulations

Bovine serum albumin (BSA) is a commonly used model protein in the development of pharmaceutical formulations. In order to assay its release from various dosage forms, either the bicinchoninic acid (BCA) assay or a more specific size-exclusion high performance liquid chromatography (SE-HPLC) method are commonly employed. However, these can give erroneous results in the presence of some commonly-used pharmaceutical excipients. We therefore investigated the ability of these methods to accurately determine BSA concentrations in pharmaceutical formulations that also contained various polymers and compared them with a new and compared with a new reverse-phase (RP)–HPLC technique. We found that the RP-HPLC technique was the most suitable method. It gave a linear response in the range of 0.5 -100 µg/ml with a correlation coefficient of 0.9999, a limit of detection of 0.11 µg/ml and quantification of 0.33 µg/ml. The performed ‘t’ test for the estimated and theoretical concentration indicated no significant difference between them providing the accuracy. Low % relative standard deviation values (0.8-1.39%) indicate the precision of the method. Furthermore, the method was used to quantify in vitro BSA release from polymeric freeze-dried formulations.

Heart Rhythm UK position statement on clinical indications for implantable cardioverter defibrillators in adult patients with familial sudden cardiac death syndromes

Whilst the decision regarding defibrillator implantation in a patient with a familial sudden cardiac death syndrome is likely to be most significant for any particular individual, the clinical decision-making process itself is complex and requires interpretation and extrapolation of information from a number of different sources. This document provides recommendations for adult patients with the congenital Long QT syndromes, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia, hypertrophic cardiomyopathy, and arrhythmogenic right ventricular cardiomyopathy. Although these specific conditions differ in terms of clinical features and prognosis, it is possible and logical to take an approach to determining a threshold for implantable cardioveter-defibrillator implantation that is common to all of the familial sudden cardiac death syndromes based on estimates of absolute risk of sudden death. Published on behalf of the European Society of Cardiology. © The Author 2010.

'Someone Big and Important': Identification and Affect in an International Development Organization

Psychoanalysis has been widely used to develop our understanding of power in organizations. In this paper, I draw on a case study of a non-profit organization in the field of international development, in order to explore in depth how people engage with powerful discourses at play in this context. I use an ethnographic approach to do so, and find Lacan's ideas on identification and affect to be useful in the analysis of the case. I show how, at first glance, people appeared to readily alter their activities and goals in response to the wishes of an important donor. However, moving deeper to examine identifications on the part of people themselves reveals complex forms of recognition that were inscribed by affective relations. I discuss the implications of these findings for the study of organizations, including the contribution of the concept of affect for studies of identification and subjection in organizations, and the value of ethnographic research approaches that draw upon Lacan's work on recognition.

Char oxidation of torrefied biomass at high temperatures and high heating rates

The char oxidation of a torrefied biomass and its parent material was carried out in an isothermal plug flow reactor (IPFR), which is able to rapidly heat the biomass particles to a maximum temperature of 1400 °C at a heating rate of 104 °C/s, similar to the real conditions found in power plant furnaces. During each char oxidation test, the residues of biomass particles were collected and analyzed to determine the weight loss based on the ash tracer method. According to the experimental results, it can be concluded that chars produced from a torrefied biomass are less reactive than the ones produced, under the same conditions, from its raw material. The apparent kinetics of the torrefied biomass and its parent material are determined by minimizing the difference between the modeled and the experimental results. The predicted weight loss during char oxidation, using the determined kinetics, agrees well with experimental results

Patterning and switching of nano-size ferroelectric memory cells

A "top-down" approach using a-beam lithography and a "bottom-up" one using self-assembly methods were used to fabricate ferroelelectric Pb(Zr,Ti)O-3, SrBi2Ta2O9 and BaTiO3 nanostructures with lateral sizes in the range of 30 nm to 100 nm. Switching of single sub-100 nm cells was achieved and piezoelectric hysteresis loops were recorded using a scanning force microscope working in piezoresponse mode. The piezoelectricity and its hysteresis acquired for 100 nm PZT cells demonstrate that a further decrease in lateral size under 100 nm appears to be possible and that the size effects are not fundamentally limiting on increase density of non-volatile ferroelectric memories in the Gbit range.

Social Work Home Visits to Children and Families in the UK: A Foucauldian Perspective

The home visit is at the heart of social work practice with children and families; it is what children and families' social workers do more than any other single activity (except for recording), and it is through the home visit that assessments are made on a daily basis about risk, protection and welfare of children. And yet it is, more than any other activity, an example of what Pithouse has called an ‘invisible trade’: it happens behind closed doors, in the most secret and intimate spaces of family life. Drawing on conceptual tools associated with the work of Foucault, this article sets out to provide a critical, chronological review of research, policy and practice on home visiting. We aim to explain how and in what ways changing discourses have shaped the emergence, legitimacy, research and practice of the social work home visit to children and families at significant time periods and in a UK context. We end by highlighting the importance for the social work profession of engagement and critical reflection on the identified themes as part of their daily practice.