Density measurement of fine aerosol fractions from wood combustion sources using ELPI distributions and image processing techniques

Aerosols from combustion sources are of high concern since they present a risk for health and environment. Particle size distribution of aerosols and in particular number size distribution are easily and quickly obtained using an Electrical Low Pressure Impactor (ELPI). However, this technique is depending of aerosol density; ρ, which may lead to biased particle size distributions. Aerosol density from combustion sources is usually not well known and depends on several parameters. Aerosol density cannot be measured with usual methods since there is generally not enough matter collected on each stage of the ELPI. Our approach uses electronic microscopy to evaluate ρ at each impaction stage in order to increase the accuracy of the number size distributions resulting from the ELPI measurements.Particles were collected on glass substrates deposited on each impaction stages. Images were obtained using a scanning electron microscope and image processing tools were applied.This method was first tested with silica particles resulting from a combustion process which have a constant density found to be comprised between 2.2 and 2.4 g cm⁻³ for stages 2 (57 and 95 nm) and 3 (95 and 158 nm), respectively. Once validated, this method was used to determine the density of wood combustion aerosols. The results match well for fly ashes from wood combustion with densities varying from 1.1 to 3.0 g cm⁻³ for particles of mean equivalent diameter ranging from 69 to 157 nm, respectively.     

Distributive justice, procedural justice, and psychological distress: The moderating effect of coworker support and work autonomy.

Recent research has demonstrated that the perception of injustice at work may increase psychological health-related problems. The purpose of this study is to examine the moderating effect of coworker support and work autonomy on the relationships between both distributive and procedural justice and psychological distress. Results, on the basis of responses to questionnaires given to 248 prison employees, show that coworker support moderates the relationships between both forms of justice and psychological distress. Specifically, these relationships are weakened when employees benefit from a high level of coworker support. Furthermore, work autonomy moderates the relationship between procedural justice and psychological distress but not the relationship between distributive justice and psychological distress. Thus, procedural injustice is less likely to increase psychological distress when the level of work autonomy is high. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A numerical photogrammetry technique for measuring microscale kinematics and fabric in Schneebeli materials

We present a numerical photogrammetry technique for obtaining semi–automated measurements concerning kinematic fields, i.e. translation and rotation of each “grain”, and fabric properties of a two-dimensional analogue granular material. An example is given in which the technique is applied in a biaxial compression test on a specimen consisting of 1,300 rods. The information that can be recorded by the technique is discussed along with its accuracy. This work is funded by the EU project Degradation and Instabilities in Geomaterials with Application to Hazard Mitigation (DIGA) in the framework of the Human Potential Program, Research Training Networks (HPRN-CT-2002-00220).     

Time course of cardiac conditioned responses in restrained rats as a function of the trace CS–US interval.

Two experiments aimed at understanding the temporal characteristics of trace-conditioned heart-rate responses to a 0.5-s tone (conditioned stimulus [CS]) in restrained rats. A CS paired with a tail-shock (unconditioned stimulus [UCS]) elicited lasting bradycardiac responses. The magnitude and extinction rate of conditioned responses (CR) were independent of the CS–US interval (interstimulus interval [ISI], 3 s to 20 s). Unreinforced test trials were analyzed for CR topography. Responding was delayed in groups with longer ISIs, but CR latencies, peak and decay times were not proportional to the ISI Response peaks tended to cluster either about 6 s after CS onset, or about 10 s with a slow decay, depending on the ISI. The authors postulated 2 components of auditory stimulus traces involved in cardiac conditioning, maximally active 6 s and 10 s respectively after CS onset. The topography of the CR could be constrained to combinations of associative strength and instantaneous activity of these 2 components. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Three-stage DEA models for incorporating exogenous inputs

In this paper, we discuss three-stage models that control for exogenous, non-discretionary inputs in data envelopment analysis. In a recent article in this journal, Monte Carlo analysis was employed to compare and contrast alternative DEA models that measure efficiency in the presence of exogenous variables. The methodology for comparison was flawed, calling into question the results presented. We introduce new second-stage models and compare and contrast them with simulated data.     

Iminosugar‐Based Galactoside Mimics as Inhibitors of Galactocerebrosidase: SAR Studies and Comparison with Other Lysosomal Galactosidases

Several families of iminosugar‐based galactoside mimics were designed, synthesized, and evaluated as galactocerebrosidase (GALC) inhibitors. They were also tested as inhibitors of lysosomal β‐ and α‐galactosidases in order to find new potent and selective pharmacological chaperones for treatment of the lysosomal storage disorder, Krabbe disease. Whereas 1‐C‐alkyl imino‐L ‐arabinitols are totally inactive toward the three enzymes, 1‐C‐alkyl imino‐D ‐galactitols were found to be active only toward α‐galactosidase A. Finally, 1‐N‐iminosugars provided the best results, as 4‐epi‐isofagomine was found to be a good inhibitor of both lysosomal β‐galactosidase and GALC. Further elaboration of this structure is required to achieve selectivity between these two galactosidases.     

Annealing of drawn monofilaments of liquid crystalline polymer vectra/vapor grown carbon fiber nanocomposites

The annealing treatment of drawn LCP nanocomposite monofilaments is discussed here. Upon annealing, an unstable structure is generated which presents a strong dependence on the annealing time sequence and temperature as observed by DSC. Moreover, it seems that increasing the draw down of the fiber restricts the formation of this new (unstable) structure. Based on dynamic mechanical analysis and on solid state ¹³C NMR, the nature of the newly-formed structure is elucidated, and based on sequence ordering within the non-oriented amorphous phase in the copolymer, a 10% change in the monomer proportion in the ordered phase is observed after annealing.     

Study of the chemical composition of edible red macroalgae Grateloupia turuturu from Brittany (France)

The chemical composition and its seasonal variation of the red seaweed Grateloupia turuturu, an invasive macroalgae from Brittany, France, were investigated. Size, ash, protein, lipid, dietary fibre (soluble, insoluble and total), protein pigment (R-phycoerythrin, R-phycocyanin), and fatty acid content were measured in G. turuturu samples collected over 1 year (2006). The average size of this seaweed was 32.0 cm long and approximately 5.0 cm wide, while the size of the thallus was maximal in June (in length and width). On the dry weight basis, this alga was constituted of more than 18% ash, about 23% protein, 2.6% lipids, and approximately 60% dietary fibre. The most abundant fatty acids were palmitic acid and eicosapentaenoic acid (52% and 12% of the fatty acid fraction, respectively). The study of seasonal variations showed that the best period to collect the seaweed for food use is between February and June.