Separation of particles from hot gases using metallic foams

One of the most complicated tasks in the field of hot gas cleaning is the removal of particles from a complex mixture of degradation products formed during thermal treatment. A robust and completely reliable technology is still to be developed to achieve high efficiencies. In the past few years, significant improvements have been brought to gas cleaning technologies. Nevertheless, none of the existing processes has proved fully successful.The aim of this work is to perform the filtration of particles generated in fluidized bed gasification experiments using metallic foams. The gasified material used is dried sewage sludge. Nickel–chromium metallic foams are likely to have inherent properties that would make them suitable for use in structures where strength, high temperature-resistance and corrosion resistance are required. Moreover, metallic foams are characterized structurally by their cell topology, relative density, high porosity (? = 0.95) and cell size. In hot gas filtration, high temperature-resistance and low pressure drop to specific area ratio are essential characteristics. In the present work, several experimental operating conditions (heating time, temperature, washing method and metallic foam thickness) are investigated. The pressure drops in the metallic foams during filtration are calculated. The experimental results obtained are compared with numerical simulation results and a good agreement is obtained. The metallic foams are simulated from tomography results and a model is created.     

Zoos as settings for psychological research: A preliminary survey.

Presents survey results that support D. B. Miller's (see record 1977-28610-001) proposal that US zoological parks are appropriate environments for naturalistic comparative psychological research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Zoos worldwide as settings for psychological research: A survey.

Surveyed ongoing and future possibilities for comparative psychological research at overseas zoos by questionnaire. Results indicate that 92 (75.4%) of the zoos in 19 (70.7%) of the countries responding would welcome sound proposals for comparative psychological research. 19 preconditions for potential investigators to consider before designing and beginning projected research at overseas zoos are presented. In addition to formal answers to the survey, various zoo personnel offered comments and information concerning their sites. (12 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Association of biochemical and subjective indicators of drinking habits with performance on different neurobehavioral tasks

The present paper outlines the association of biochemical and subjective indicators of alcohol consumption. Due to its relevance as a potential confounding variable in occupational neurotoxicology, both sources of information about drinking habits were related to neurobehavioral test performance. A sample of 308 rotogravure printers and control subjects from a cross-sectional longitudinal study in various German printing plants was studied. Duration of employment was 4 months to 44 years (mean = 14.9, sd = 9.67). Mean age was 38.4 years (range 21 - 60). From venous blood samples three parameters considered to be sensitive for increased consumption of alcohol were used. They were carbohydrate-deficient transferrin (CDT), gamma glutamyl transferase (GGT), and mean cell volume (MCV). During the medical interview subjects with any chronic liver disease were identified and excluded from data analysis. Additionally, information about weekly consumption of alcohol was assessed and transformed to grams per day (g/d) values. Neurobehavioral testing included simple reaction time (SPES version), switching attention, symbol digit substitution, and digit span (EURONEST version). Additionally, a questionnaire of neurotoxic complaints was administrated. Other covariates, i.e. verbal ability, history of solvent exposure, and age were controlled. GGT and CDT were elevated in 10.5% and 6.6% of the population. 3.5% of the subjects reported daily consumption higher than 60 gram. There were positive correlations of CDT and GGT with the subjective indicator of drinking habits. The magnitude of these relationships were low, but the associations were significant. MCV was not correlated with subjective reports of drinking habits, but it showed convergent correlations with CDT and GGT. Comparison of these two parameters with performance on neurobehavioral tasks yielded only one negative association, i.e. between the memory-loaded tasks factor and GGT. CDT and subjective estimation of alcohol consumption were not related to any cognitive function tested in this study. Especially, the digits-backward task was negatively correlated with increased GGT.     

Seasonal and regional variation in triglyceride composition of French butterfat

In the present study, high-performance liquid chromatography analysis of butterfat allowed separation of 46 peaks at 32°C. Knowing the theoretical carbon number value of each triglyceride (TG), 32 peaks of the butterfat chromatogram were identified. These TGs were determined by extrapolation of their capacity factor values, and their identifications were confirmed with some standard TGs. Analysis of winter and summer butterfat from five different French areas showed significant seasonal and regional variation in the TG composition. However, the most important contribution to this variation was provided by TG groups represented by only four peaks. To approximately select the predominant TGs in these four peaks, a random distribution hypothesis was used to predict the amount of each TG. This hypothesis allowed the prediction of the TG components that seem to provide the most important contribution to both seasonal and regional variation.     

A comparative study of manganese and lead levels in human umbilical cords and maternal blood from two urban centers exposed to different gasoline additives

Manganese (Mn) and lead (Pb) are two neurotoxic chemicals and experimental evidence suggests that they can cross the placental barrier. Tetraethyl lead was still in use as an antiknock agent in Paris during the sampling period of the study, while it has been replaced by methylcyclopentadienyl manganese tricarbonyl (MMT) in Canada since 1977. By 1990, MMT was in 100% of gasoline in Canada. In a study of 160 pairs of mothers-neonates in Montreal and 206 pairs in Paris, we compared levels of Mn and Pb in the umbilical cord and in maternal blood. Neonates and mothers had significantly higher Pb levels in Paris where lead additives were still used in gasoline. Geometric mean maternal blood Pb levels were 5.4 microg/dl compared to 2.1 microg/dl in Montreal and cord blood Pb levels were 3.2 microg/dl in Parisian mothers compared to 1.7 microg/dl in Montreal. The prevalence of Paris Pb values superior to the 95th percentile of the Montreal distribution was highly elevated in all media studied. The prevalence of high Mn levels in umbilical cord blood was also significantly higher in Montreal. Surveillance programs are important to limit Pb overexposure and associated neurological effects in neonates where tetraethyl Pb is still in use as a gasoline additive. Since Mn is an essential element and dietary Mn intake may differ between Montreal and Paris, the difference observed with regard to high Mn values between Montreal and Paris cannot, at this time, be attributed to MMT in Montreal's gasoline. Further studies are needed to infer an association between Mn emissions from MMT and prenatal exposure to Mn.     

Binding of small mono- and oligomeric integrin ligands to membrane-embedded integrins monitored by surface plasmon-enhanced fluorescence spectroscopy

We recently developed a binding assay format by incorporating native transmembrane receptors into artificial phospholipid bilayers on biosensor devices for surface plasmon resonance spectroscopy. By extending the method to surface plasmon-enhanced fluorescence spectroscopy (SPFS), sensitive recording of the association of even very small ligands is enabled. Herewith, we monitored binding of synthetic mono- and oligomeric RGD-based peptides and peptidomimetics to integrins alphavbeta3 and alphavbeta5, after having confirmed correct orientation and functionality of membrane-embedded integrins. We evaluated integrin binding of RGD multimers linked together via aminohexanoic acid (Ahx) spacers and showed that the dimer revealed higher binding activity than the tetramer, followed by the RGD monomers. The peptidomimetic was also found to be highly active with a slightly higher selectivity toward alphavbeta3. The different compounds were also evaluated in in vitro cell adhesion tests for their capacity to interfere with alphavbeta3-mediated cell attachment to vitronectin. We hereby demonstrated that the different RGD monomers were similarly effective; the RGD dimer and tetramer showed comparable IC50 values, which were, however, significantly higher than those of the monomers. Best cell detachment from vitronectin was achieved by the peptidomimetic. The novel SPFS-binding assay platform proves to be a suitable, reliable, and sensitive method to monitor the binding capacity of small ligands to native transmembrane receptors, here demonstrated for integrins.     

The impact of logistical resources on prereferral team acceptability.

This study investigated the impact of logistical resources on the acceptability of student assistance team consultation to school staff. Elementary and middle school staff (N = 113) completed a measure of the acceptability of prereferral intervention team procedures while also rating the importance of five logistical supports for effective team functioning. A multiple regression analysis showed that the team process was more acceptable to staff who perceived these teams to be effective for helping students and to those who identified three supports for effective teaming: sufficient staff training in team procedures, adequate numbers of staff, and ample time. Results are discussed in the context of prior investigations, directions for future research, and implications for school practice. (PsycINFO Database Record (c) 2010 APA, all rights reserved)