Screening of Fe–Cu-Zeolites Prepared by Different Methodology for Application in NSR–SCR Combined DeNOx Systems

The NO_x NH₃-SCR performance of several Cu and Fe catalysts supported on BETA and ZSM-5 zeolites has been studied in single SCR and double NSR–SCR configuration, and the activity related to the nature and reducibility of metal species on the catalyst surface. Intermediate ammonia formed in NSR improved greatly NO_x conversion at the exit of the double NSR–SCR configuration, which was practically totally converted to N₂.     

Effect of pasteurization of Ewe's milk and use of a native starter culture on the volatile components and sensory characteristics of roncal cheese.

The effect of pasteurization of milk and use of a native starter culture on the volatile components and sensory characteristics of a Spanish ewe's-milk cheese were examined. Three cheese batches were made, one from raw milk, another from pasteurized milk, and a third from pasteurized milk with an added native starter culture in addition to the commercial starter. Cheeses were analyzed at 1, 120, and 240 d of ripening. Analysis of the volatile components was by purge and trap connected to a gas chromatograph with a mass spectrometer and disclosed a total of 76 components belonging to the following chemical families: hydrocarbons, fatty acids, esters, sulfur and carbonyl compounds, and, in particular, alcohols. Pasteurization lowered the levels of certain volatile components, especially alcohols, aldehydes, and ketones. The cheeses made from pasteurized milk showed lower scores for attributes of characteristic taste and aftertaste, as well as a characteristic aroma at 240 d of ripening. These results suggest that the components present in higher concentrations in the cheeses made from the raw milk were necessary for development of characteristic Roncal cheese aroma. The new native starter culture tested did not exert a significant effect on any of the parameters considered, with the exception of certain isolated components, for which higher or lower quantities were recorded in the cheeses made with that starter culture, although the differences did not have a definite effect on the sensory characteristics of the cheeses.     

On the Effect of Reduction and Ageing on the TWC Activity of Pt/Ce0.68Zr0.32O2 under Simulated Automotive Exhausts

The three-way activity under complex feed-streams of a series of Pt/Ce_0.68Zr_0.32O₂ catalysts, either fresh or submitted to different ageing treatments, both before and after reduction, has been studied and related to the species present on the catalysts in view of their characteristics and TPR behaviour.     

Large Bolometer Arrays with Superconducting NbSi Sensors for Future Space Experiments

New techniques in microelectronics allow to build large arrays of bolometers filling the focal plane of submillimeter and millimeter telescopes. The expected sensitivity increase is the key for the next generation of space experiments in this wavelength range. Superconducting bolometers offer currently the best prospects in terms of sensitivity and multiplexed readout. We present here the developments led in France based on NbSi alloy thermometers. The manufacturing process of a 23 pixel array and the test setup are described.      

The acoustic startle response and disruption of aiming: II. Modulation by forewarning and preliminary stimuli

Four experiments examined the disruption of rifle aim by intense noise bursts. In Experiment 1 a trigger pull was followed occasionally by a noise burst. Aiming was disrupted for 1-2 s, an effect that habituated within days and recovered between days. Expected stimuli were less disruptive than were unexpected stimuli. Experiment 2 demonstrated that weak auditory prestimuli 100 ms before unexpected intense sounds also reduced noise-produced errors. Experiment 3 showed that the intratympanic reflex had not played a protective role in this effect. Experiment 4 showed that a weak tactile prestimulus increased both a muscular measure of the acoustic startle reaction and the perturbing effect of the noise burst on motor performance. In general, conditions that affect the amplitude of the acoustic startle reflex similarly influence the disruptive effect of a noise burst on motor performance, but the two measures are not correlated in the detail necessary to suggest a causative relationship.     

Temperature variation of magnetic aftereffect

The paper analyzes the anomalous behavior of the magnetic aftereffect decay coefficient with temperature, which has been established experimentally from a thermodynamic point of view. The Arrhenius law, which has often been used to model magnetic aftereffect, is based on the Maxwell-Boltzmann (MB) statistics. At low temperatures, however, magnons obey Bose-Einstein (BE) statistics, which have a different energy spectrum. MB statistics are a good approximation to BE statistics in the temperature range in which most devices operate. The variation in temperature, governed by chemical potential that is essentially linear, has a negative slope and is zero below a low but finite temperature. Other explanations for this anomalous behavior would predict an incorrect type of temperature dependence. This new interpretation of magnetic aftereffect may have profound implications on accelerated testing to determine life expectancy of recordings     

Italian multicentre study on microbial environmental contamination in dental clinics: a pilot study

The dental practice is associated with a high risk of infections, both for patients and healthcare operators, and the environment may play an important role in the transmission of infectious diseases. A microbiological environmental investigation was carried out in six dental clinics as a pilot study for a larger multicentre study that will be performed by the Italian SItI (Society of Hygiene, Preventive Medicine and Public Health) working group "Hygiene in Dentistry". Microbial contamination of water, air and surfaces was assessed in each clinic during the five working days of the week, before and during treatments. Air and surfaces were also examined at the end of the daily activity. A wide variation was found in microbial environmental contamination, both within the participating clinics and relative to the different sampling times. Microbial water contamination in Dental Unit Water Systems (DUWS) reached values of up to 26 × 10⁴ cfu/mL (colony forming units per millilitre). P. aeruginosa was found in 33% of the sampled DUWS and Legionella spp. in 50%. A significant decrease in the Total Viable Count (TVC) was recorded during the activity. Microbial air contamination showed the highest levels during dental treatments and tended to decrease at the end of the working activity (p < 0.05). Microbial buildup on surfaces increased significantly during the working hours. As these findings point out, research on microbial environmental contamination and the related risk factors in dental clinics should be expanded and should also be based on larger collections of data, in order to provide the essential knowledge aimed at targeted preventive interventions.     

Synthesis of Fatty Acid Amides of Catechol Metabolites that Exhibit Antiobesity Properties

A series of fatty acid amides of 3,4‐methylenedioxymethamphetamine (MDMA) catechol metabolites were synthesized in order to evaluate their biological activities. Upon administration, all synthesized compounds resulted in negative modulation of food intake in rats. The most active compounds have affinity for the CB₁ receptor and/or PPAR‐α; part of their biological activity may be caused by these double interactions.     

Tunable TiO2 (anatase and rutile) materials manufactured by mechanical means

Anatase and rutile are two naturally found titanium dioxide phases with attractive dielectric, catalytic, and photo-catalytic characteristics. Anatase and rutile are photo-catalytically active in the UV region, since their band gaps are 3.2 eV and 3.75 eV, respectively. In this work is proposed a cost-effective, easy to launch methodology for modification of the TiO₂ bandgap. Such modifications will make the oxides photo-catalytically active in a wider optical range from the visible wavelengths to an extended UV spectrum. The proposed methodology is based on mechanical means such as mixing and milling. Various ratios of anatase:rutile were investigated and milled from 0 (mixing only) to 50 h using high energy mills. The results on mixing and milling show that it is possible to modify the bandgap of the TiO₂ from 2.53 eV to 4.04 eV. The characterization was conducted by means of X-ray diffraction, Raman spectroscopy, Scanning electron microscopy, and optical spectroscopy.