Performance evaluation of a biotrickling filter degrading mixtures of hydrophobic and hydrophilic compounds

The removal of a mixture of painting solvents from waste air using a biofiltration process was evaluated in this project. The pollutants removed included hydrophobic (aromatic hydrocarbons) and hydrophilic (water soluble ketones and esters) compounds. A trickle bed reactor with a defined immobilized mixed culture on polyethylene Pall rings was utilized in this biodegradation study. The removal efficiencies (RE) of the individual groups of pollutants during loading experiments were determined. An increase of the aromatic hydrocarbons loading resulted in a drop of their RE_AROM with no effect on the RE value of ketones. The overloading of ketones caused a rapid drop in RE_AROM and a small drop in RE_KET. To achieve a restoration of the biocatalyst degradation properties after the increase in loading, an addition of phosphate to the aqueous medium was implemented which successfully restored the removal efficiency.     

Effect of Floodwater Extraction on Mountain Stream Morphology

Floodwater is often extracted for consumptive purposes from western mountain streams in the United States. The long-term extraction of floodwater may alter the morphological and ecological balance of such streams. Scale model experiments based on eight mountain gravel-bed streams in Idaho were conducted to test the effects of floodwater extraction on stream morphology. The model channel transported a poorly sorted mix of model “gravel,” as well as copious amounts of model “sand.” The channel had a discontinuous floodplain, developed its own bar morphology, and contained large model colluvium as well as a bedrock platform. A mobile-bed equilibrium was first developed using a repeated hydrograph. The experiment was then repeated using a sliding cutoff discharge. The discharges in the hydrograph that were below a given cutoff discharge were reduced to 30% of bankfull discharge. By raising the cutoff discharge, it was possible to study the effect of increasing severity of floodwater extraction on stream morphology. The experiments indicated an increase in sand content on the bed surface and a decrease in the standard deviation of fluctuations in bed elevation with increasing severity of floodwater extraction.     

Chalcogenide Glasses Based on Germanium Disulfide for Second Harmonic Generation

High second‐order susceptibilities are created by thermal poling in bulk germanium disulfide based chalcogenide glasses. Experimental conditions of the poling treatment (temperature, voltage, time) were optimized for each glass composition. The second‐order nonlinear signals were recorded by using the Maker fringes experiment and a second‐order coefficient χ⁽²⁾ up to 8 pm V^–1 was measured in the Ge₂₅Sb₁₀S₆₅ glass. This value is obtained using a simulation based on accurate knowledge of the thickness of the nonlinear layer. Two mechanisms are proposed to explain the creation of a nonlinear layer under the anode: the formation and the migration of charged defects towards the anode may mainly occur in Ge₂₀Ga₅Sb₁₀S₆₅ and Ge₂₅Ga₅S₇₀ glasses, whereas the migration of Na⁺ ions towards the cathode may be responsible for the accumulation of negative charges under the anode in Ge₃₃S₆₇ and Ge₂₅Sb₁₀S₆₅ glasses. Different electronic conductivity behaviors seem to be at the origin of the phenomenon. In parallel, the potential effect of the poling treatment on the structural and electronic properties is studied using Raman spectroscopy and secondary ion mass spectroscopy measurements.     

Estimation of thermal diffusivity of foods using transfer functions

The effective thermal diffusivity of foodstuffs was estimated from time-temperature histories in the geometric center of samples exposed to heating and cooling processes.Transfer functions methodology was used as an alternative method to estimate the thermal diffusivity assuming that conduction was the main heat transfer mechanism. The samples were characterized as delayed first-order systems with unit gain, dead time (L) and time constant (τ).The results were compared with those obtained from the f_h value and with results reported in the literature.     

"The association between emotional upset and cardiac arrhythmia during daily life": Correction to Carels et al. (2003).

Reports an error in the original article by R. A. Carels et al (Journal of Consulting & Clinical Psychology, 2003[Jun], Vol 71[3], 613-618). On page 615, Lines 18, 20, 22, of Table 1, the data in the rows that read "Tachycardia in min per hr," "Repetitive PVCs per hr," and "PVCs per hr" are incorrectly reported in the n and % columns. They should have been reported in the M and SD columns. The corrected table is provided. (The following abstract of this article originally appeared in record 2003-00756-023.) Ventricular arrhythmia exhibits considerable within-subject variability that cannot be attributed to clinical status alone. This investigation examined the extent to which cardiac arrhythmia was associated with psychological and physical factors assessed during the hour preceding arrhythmic or nonarrhythmic activity. Approximately twice hourly, 46 patients randomly completed a diary assessing mood and physical symptoms during 24-hr electrocardiographic monitoring. Greater negative emotion was associated with increased arrhythmia. Additionally, greater negative emotion was significantly associated with increased arrhythmia among participants in a low left ventricular ejection fraction group (LVEF). However, this relationship between negative emotion and arrhythmia was not... (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fe-substituted (La,Sr)TiO3 as potential electrodes for symmetrical fuel cells (SFCs)

In the work presented herein, the potential use of La₄Sr₈Ti_12−xFe_xO_38−δ (LSTF) materials as electrodes for a new concept of solid oxide fuel cells, symmetrical fuel cells (SFCs), is considered. Such fuel cells use simultaneously the same material as anode and cathode, which notably simplifies the assembly and further maintenance of the cells. Therefore, we search for materials showing high conductivity in a wide range of oxygen partial pressures in addition to certain degree of catalytic activity for the oxidation of the fuel and reduction of the oxidant, respectively. The preliminary electrochemical experiments performed reveal that the overall conductivity increases notably upon Fe substitution, being the main contribution electronic n-type. The fuel cell tests indicate that LSTF composites with YSZ and CeO₂ perform reasonably well under H₂ conditions, although the performance in methane is rather modest and require further optimisation.     

Virtual reality is for real

Some current applications work in the computer-rendered environments known as virtual reality (VR) are examined. Caterpillar Inc., a manufacturer of earth-moving and construction equipment is using VR to assess interior visibility on new prototypes. The Big Three among US automobile makers are joining with a US Army vehicle center, United Technologies' automotive division, the University of Michigan, and a dozen other smaller companies to form a consortium for industrial VR. Boeings' new airliner, the 777, to be rolled out next year, is its first to be designed without the use of a full-scale physical mockup; VR was used instead. Military, medical, and entertainment applications of VR are growing     

Post-translational cleavage of a histone H1-like protein in the sperm of Mytilus

Starting with total RNA from spermatogenic cells of Mytilus trossulus and using random priming, we have cloned and sequenced the c-DNAs corresponding to two variants of the sperm-specific protein PLII* (phi 2B). DNA sequencing in conjunction with mass spectrometry and protein sequence data have allowed us to establish that of the three sperm-specific proteins present in the sperm of Mytilus (PL-II*(phi 2B), PL-III (phi 1), PL-IV (phi 3)), the first and the last one are the result of post-translational cleavage of a common precursor. This common precursor is a member of the histone H1 family, and it exhibits inter- and intraspecific microheterogeneity.     

Monoclonal antibodies to bovine growth hormone potentiate hormonal activity in vivo by enhancing growth hormone binding to hepatic somatogenic receptors

Administration of GH complexed with monoclonal antibodies (MABs) potentiates the in vivo actions of the hormone. In particular, growth and serum IGF-I concentrations of GH-treated hypophysectomized rats are increased by concomitant injection of anti-GH MABs. Among 37 anti-bovine GH (bGH) MABs, we selected one MAB with the most potentiating effects to investigate the mechanisms responsible for this phenomenon. Hypophysectomized rats were killed 18 h after a single s.c. injection of bGH (100 micrograms/rat), alone or complexed with increasing doses of MAB (4, 40, 400 micrograms/rat; MAB:bGH molar ratio: 0.005, 0.05, 0.5). IGF-I was measured by radioimmunoassay in acid-extracted sera and livers, whereas liver IGF-I mRNA was quantified by Northern blot hybridization. The in vivo occupancy of liver somatogenic (GH) receptors was derived from the determinations of total and free 125I-labelled bGH binding to liver homogenates treated with 4 mol MgCl2/l or water. Injection of MAB-bGH complexes enhanced body weight gain and raised serum IGF-I, liver IGF-I and liver IGF-I mRNA more than bGH alone (1.6-, 6-, 10- and 7-fold increases at the highest dose of MAB, compared with bGH alone; P < 0.001). These potentiating effects of the MAB were dose-dependent and significant potentiation of the growth response was already observed with the lowest dose of MAB. In vivo occupancy of liver GH receptors was markedly higher 18 h after injection of MAB-bGH complexes than after bGH alone, and this effect was also dose-dependent (receptor occupancy of 28%, 37% and 83% after 4, 40 and 400 micrograms of MAB respectively compared with 6% after bGH alone; P < 0.05, 0.05 and 0.001 respectively). In contrast, the in vitro binding of 125I-labelled bGH to liver homogenates was decreased in the presence of high doses of MAB. We conclude that low amounts of MABs complexed with bGH potentiate the stimulation by the hormone of liver IGF-I synthesis and secretion in a dose-dependent manner. These effects are mediated, at least in part, through changes in hormone-receptor interaction in vivo, leading to enhanced and/or prolonged binding of bGH to its somatogenic receptors.