The application of stereoscopic PIV to measure the flow of air into an enclosure containing a fire

Flow fields encountered in full-scale enclosure fires are highly three-dimensional and span a large spatial extent. Stereoscopic particle image velocimetry (SPIV) was applied to provide a large-scale planar interrogation of the flow of air available to a series of fires burning inside an enclosure. Time-averaged velocity fields across the doorway of the enclosure are presented. These flows are bi-directional and SPIV reveals that the time-averaged height of the region of flow reversal depends on location within the doorway. The volume flow rate of available air computed from the classical one-dimensional flow approach agrees well with the numerical integration using the velocity field provided by SPIV. Good agreement between the measured velocities for SPIV configurations optimized for seed particle displacements along the laser sheet axis and optimized for displacements perpendicular to the laser sheet demonstrate that large-scale SPIV measurements can be conducted with very good precision.     

Capillary electrophoretic determination of oxalate in amniotic fluid

A capillary electrophoretic (CE) assay for oxalate has been applied to the quantitative determination of free oxalate in amniotic fluid. Indirect absorbance detection of oxalate is accomplished with a chromate-based background electrolyte modified with ethylenediaminetetraacetic acid (EDTA). Detection interference due to the presence of high levels (≈4 mg/ml) of inorganic chloride is eliminated through a direct sample clean-up procedure based on cation (Ag⁺-form) resins. Separation interference from amniotic fluid proteins is prevented through the use of a simple aqueous-based dilution procedure. This method for the determination of oxalate in amniotic fluid provides precision of ≈5% relative standard deviation (RSD). Within-day precisions for the oxalate response and migration time are better than 3% RSD and 1% RSD, respectively. Between-day precisions for the oxalate response and migration time are better than 6% RSD and 3% RSD, respectively. The analytical recovery of oxalate (1000 ng/ml) spiked into amniotic fluid was better than 96%. The limit of detection (LOD) for the method is ≈100 ng/ml oxalate. This method also shows promising results for the determination of oxalate in human blood plasma samples.     

Linkage effects on binding affinity and activation of GPR30 and estrogen receptors ERalpha/beta with tridentate pyridin-2-yl hydrazine tricarbonyl-Re/(99m)Tc(I) chelates

We describe a new structural class of neutral tridentate pyridin-2-yl hydrazine chelates for labeling with tricarbonyl Re/99mTc(I) under aqueous conditions and investigate the receptor binding of synthetic estradiol derivatives with the novel G-protein-coupled receptor GPR30 and estrogen receptors ERalpha/beta. The steroid linkage affected the affinity and selectivity of estrogen binding with these receptors. Fluorescence assays based on calcium signaling demonstrate that membrane-permeable chelates 2 and 3 interact with the receptors in whole cells. These results suggest that in vitro assays will facilitate the development of targeted imaging agents for intracellular receptors and the feasibility of targeting GPR30 and ERalpha/beta for diagnostic tumor imaging.     

Diagnostic ultrasound artifacts during imaging of two-body interfaces: part 2--beam thickness artifact

A diagnostic ultrasound method is being developed for measuring surface contact areas at the tibio–femoral interface of a total knee replacement in a non-clinical industrial setting as an engineering design tool. As an initial step towards this, a previous study mathematically predicted the effect of ultrasound beam thickness on contact area measurements at a two-body interface. In the current study, a novel metal-on-polymer acoustic test object was constructed to create circular two-body interfaces of known geometry. The object was ultrasonically imaged, contact areas measured, and the results compared with the theoretical model previously developed.     

Author index to volume 90A

Proton spin-lattice relaxation has been investigated at three frequencies in two polycrystalline proteins, lysozyme and α-chymotrypsin, between 10 and 300 K. Methyl group reorientation is identified as the main source of relaxation, but other dynamical processes also contribute.     

Flow models for assessing human activities

The concept of flow is a fundamental one in describing human activities. This paper outlines recent modelling work which describes systems in terms of physical flows. The role of such models in assessing system changes is discussed using an extended case study from the field of natural resource analysis, and the complementary nature of environmental, economic and other bases of evaluation is considered.     

Convexity spaces. II. Separation

This is the second of a series of three papers dealing with convexity spaces. In the first paper [1] we defined a convexity space and investigated some of its basic properties. Here we consider the separation and support of convex sets. Throughout the paper we will be dealing with a convexity space (X, ·) and the terminology and notation used will be those of [1]. In particular A^c denotes the complement of the set A in X and β is used to denote set-theoretic difference.