Survey of undeclared egg allergen levels in the most frequently recalled food types (including products bearing precautionary labelling)

Since the number of recalls involving undeclared allergens is commonly associated with bakery and snack foods, we aimed to determine the frequency of egg allergens in a large number of these products using two commercial enzyme-linked immunosorbent assay (ELISA) methods. Samples were chosen that either had no egg identified on the product label or which had an egg precautionary statement. Among all samples, egg protein was detected in 5% of products using a Morinaga (MO) kit and 1% of products using a R-Biopharm (RB) kit. For bakery samples, egg protein was detected in 6% of 363 samples with no precautionary labelling (6% by MO and 1% by RB kit) and 12% of 80 samples which had precautionary labelling. For snack samples, egg protein was detected in 2% of 371 samples with no precautionary labelling (2% by MO and < 1% by RB kit) and 5% of 21 samples which had precautionary labelling. The disagreement rates between two methods were 5.2% for bakery products and 2.6% for snack products. The sample repeatability was at an acceptable level for bakery (< 12.5%) and snack foods (< 7.5%) for each method. The relative standard deviation between test kits was high (103.1%) for bakery foods. Four bakery products without precautionary labelling had a higher level of egg protein per serving compared with the eliciting dose (ED₁₀ of 3.7 mg protein) for egg allergic patients. These results highlight the fact that detection methodology plays a vital role for accurate labelling control and mitigation of risk for egg allergic consumers.     

Stormwater and fire as sources of black carbon nanoparticles to Lake Tahoe

Emitted to the atmosphere through fire and fossil fuel combustion, refractory black carbon nanoparticles (rBC) impact human health, climate, and the carbon cycle. Eventually these particles enter aquatic environments, where they may affect the fate of other pollutants. While ubiquitous, the particles are still poorly characterized in freshwater systems. Here we present the results of a study determining rBC in waters of the Lake Tahoe watershed in the western United States from 2007 to 2009. The study period spanned a large fire within the Tahoe basin, seasonal snowmelt, and a number of storm events, which resulted in pulses of urban runoff into the lake with rBC concentrations up to 4 orders of magnitude higher than midlake concentrations. The results show that rBC pulses from both the fire and urban runoff were rapidly attenuated suggesting unexpected aggregation or degradation of the particles. We find that those processes prevent rBC concentrations from building up in the clear and oligotrophic Lake Tahoe. This rapid removal of rBC soon after entry into the lake has implications for the transport of rBC in the global aquatic environment and the flux of rBC from continents to the global ocean.     

Stratification Dynamics and Geothermal Potential of a Deep Shaft in the Flooded Wolf Mine,Siegerland/Germany

Mine Water and the Environment - Mine water hydraulics and geothermal potential of a deep shaft of the flooded Wolf mine in the Siegerland ore district of the Rhenish Massif in Germany were...     

Investigations of ductile damage during the process chains of toothed functional components manufactured by sheet-bulk metal forming

Sheet-bulk metal forming processes combine conventional sheet forming processes with bulk forming of sheet semi-finished parts. In these processes the sheets undergo complex forming histories. Due to in- and out-of-plane material flow and large accumulated plastic strains, the conventional failure prediction methods for sheet metal forming such as forming limit curve fall short. As a remedy, damage models can be applied to model damage evolution during those processes. In this study, damage evolution during the production of two different toothed components from DC04 steel is investigated. In both setups, a deep drawn cup is upset to form a circumferential gearing. However, the two final products have different dimensions and forming histories. Due to combined deep drawing and upsetting processes, the material flow on the cup walls is three-dimensional and non-proportional. In this study, the numerical and experimental investigations for those parts are presented and compared. Damage evolution in the process chains is simulated with a Lemaitre damage criterion. Microstructural analysis by scanning electron microscopy is performed in the regions with high mechanical loading. It is observed that the evolution of voids in terms of void volume fraction is strongly dependent on the deformation path. The comparison of simulation results with microstructural data shows that the void volume fraction decreases in the upsetting stage after an initial increase in the drawing stage. Moreover, the concurrent numerical and microstructural analysis provides evidence that the void volume fraction decreases during compression in sheet-bulk metal forming.     

Evaluating The Extent of Bio-Polyester Polymerization in Solid Wood by Thermogravimetric Analysis

In this study, the thermogravimetric analysis (TGA) technique has been applied to determine the extent of in situ polymerization achievable in solid wood on treating with bio-polyester oligomers. Low-molecular-weight oligomers of poly(lactic acid) (PLA), poly(glycolic acid) (PGA), poly(butylene succinate) (PBS), and poly(butylene adipate) (PBA) were impregnated and then thermally polymerized within solid wood to enhance the physical properties of wood. TGA revealed a similar degree of oligomer polymerization was achieved either with pure oligomers or within the wood structure. The influence of relatively acidic treatments, such as low-molecular-weight PGA oligomers, was observed to lead to degradation of the hemicellulose wood component. Polymerization of PLA and PGA oligomer treatments which penetrate the wood cell wall gave relatively lower wood thermal stability. Treatment and polymerization of lumen filling PBS and PBA oligomers contributed to increased wood thermal stability.