Bromate Determination by X-Ray Fluorescence (XRF) to Identify Pre-Baking Potassium Bromate Addition in Bread

Wavelength-dispersive x-ray fluorescence (WDXRF) was applied to determine bromate (Br) as an indication of pre-baking bromate addition in bread. The proposed methodology needed a minimum sample preparation procedure because it was carried out directly on solid samples. The calibration of Br in bread obtained showed low detection limit and high sensitivity to distinguish precisely Br concentrations greater than natural Br. The excellent performance of the present methodology would be useful to identify pre-baking bromation in bread, which can be used to help set up a programme to control bromation in bread. Application of this methodology to bakery control caused an important reduction of bromate use in province of Córdoba, Argentina.     

Degradation of carbamazepine by Trametes versicolor in an air pulsed fluidized bed bioreactor and identification of intermediates

The paper describes the aerobic degradation of carbamazepine (CBZ), an anti-epileptic drug widely found in aquatic environment, from Erlenmeyer flask to bioreactor by the white-rot fungus Trametes versicolor. In Erlenmeyer flask, CBZ at approximately 9 mg L⁻¹ was almost completely eliminated (94%) after 6 d, while at near environmentally relevant concentrations of 50 μg L⁻¹, 61% of the contaminant was degraded in 7 d. Acridone, acridine, 10,11-dihydro-10,11-dihydroxy-CBZ, and 10, 11-epoxy-CBZ were identified as major metabolites, confirming the degradation of CBZ. The degradation process was then carried out in an air pulsed fluidized bioreactor operated in batch and continuous mode. Around 96% of CBZ was removed after 2 days in batch mode operation, and 10,11-dihydro-10,11-epoxycarbamazepine was found as unique metabolite. In bioreactor operated in continuous mode with a hydraulic retention time of 3 d, 54% of the inflow concentration (approx. 200 μg L⁻¹) was reduced at the steady state (25 d) with a CBZ degradation rate of 11.9 μg CBZ g⁻¹ dry weight d⁻¹. No metabolite was detected in the culture broth. Acute toxicity tests (Microtox) indicated that the final culture broth in both batch and continuous mode operation were non toxic, with 15 min EC50 values of 24% and 77%, respectively.     

Effectiveness of portable HEPA air cleaners on reducing indoor endotoxin,PM10, and coarse particulate matter in an agricultural cohort of children with asthma: A randomized intervention trial

We conducted a randomized trial of portable HEPA air cleaners in the homes of children age 6–12 years with asthma in the Yakima Valley, Washington. All families received asthma education while intervention families also received two HEPA cleaners (child's bedroom, living room). We collected 14-day integrated samples of endotoxin in settled dust and PM₁₀ and PM_10-2.5 in the air of the children's bedrooms at baseline and one-year follow-up, and used linear regression to compare follow-up levels, adjusting for baseline. Seventy-one families (36 HEPA, 35 control) completed the study. Baseline geometric mean (GSD) endotoxin loadings were 1565 (6.3) EU/m² and 2110 (4.9) EU/m², respectively, in HEPA vs. control homes while PM₁₀ and PM_10-2.5 were 22.5 (1.9) μg/m³ and 9.5 (2.9) μg/m³, respectively, in HEPA homes, and 19.8 (1.8) μg/m³ and 7.7 (2.0) μg/m³, respectively, in control homes. At follow-up, HEPA families had 46% lower (95% CI, 31%–57%) PM₁₀ on average than control families, consistent with prior studies. In the best-fit heterogeneous slopes model, HEPA families had 49% (95% CI, 6%–110%) and 89% lower (95% CI, 28%–177%) PM_10-2.5 at follow-up, respectively, at 50th and 75th percentile baseline concentrations. Endotoxin loadings did not differ significantly at follow-up (4% lower, HEPA homes; 95% CI, −87% to 50%).     

A computer-based simulation model for the prediction of evacuation from mass-transport vehicles

EXODUS is a prototype egress model designed to simulate the evacuation of large numbers of individuals from an enclosure. The model tracks the trajectory of individuals as they make their way out of the enclosure, or are overcome by fire hazards such as heat and toxic gases. The software is expert system based, the progressive motion and behaviour of each individual being determined by a set of heuristics or rules. EXODUS is intended, primarily, for use in mass-transport vehicles such as aircraft, but it also has application to cinema, theatres and lecture halls. EXODUS comprises five core interacting components—the movement, behaviour, passenger, hazard and toxicity submodels. These sub-components are described and model results are compared with experimental data generated from a series of competitive aircraft evacuation experiments. The model is successful in predicting the experimental trends. Finally, the capabilities of the model are demonstrated through a series of hypothetical evacuation scenarios involving a wide-body aircraft.     

Three-dimensional effect of stresses in open stope mine design

The stability graph method is widely used for open stope mine design. During the development of the method the effect of induced stresses were included by using two-dimensional or limited three-dimensional stress analysis. In this paper, three-dimensional numerical models are used to develop new induced stress curves, and to evaluate the effects on the stability graph method and open stope mine design. Significant differences are identified for the estimated stresses at the wall of the stopes, leading to an increase of the size of the stopes.     

Climatic evaluation of models that predict hourly direct irradiance from hourly global irradiance: Prospects for performance improvements

This paper presents a comprehensive evaluation of recent models designed to predict direct from global irradiance on a short time step basis. Three models are selected for the present evaluation. These were proposed by Erbs et al., Skartveit and Olseth, and Maxwell. Model validation is performed against a large array of experimental data: A total of over 60,000 global and direct data points from 14 sites in Europe and the United States. Environments range from humid oceanic to desertic, including humid continental, high altitude, subtropical, and polluted. It is found that specific models are better adapted to certain climatic types than others. However, each model is found to have a “generic” insolation-dependent error pattern across all climates. This error pattern may be deterministically corrected and yield substantial performance improvement without additional input data.     

Solubility parameters in polyoxetanes: Poly(oxetane), poly(3,3-dimethyl oxetane), and poly(3,3-diethyloxetane)

The solubility parameter of poly(oxetane), poly(3,3-dimethyloxetane) and poly(3,3-diethyl oxetane) has been estimated by measuring solution viscosities. Values of δ = 9.4, 7.9, and 7.9 cal^1/2·cm^?3/2 for each polymer were obtained and compared with those calculated from empirical methods. The 3-dimensional solubility parameter approach has been also applied in order to get additional information on the effect of structural modifications on the main chain in the solubility behavior.