Fate of Zinc Oxide Nanoparticles during Anaerobic Digestion of Wastewater and Post-Treatment Processing of Sewage Sludge

The rapid development and commercialization of nanomaterials will inevitably result in the release of nanoparticles (NPs) to the environment. As NPs often exhibit physical and chemical properties significantly different from those of their molecular or macrosize analogs, concern has been growing regarding their fate and toxicity in environmental compartments. The wastewater-sewage sludge pathway has been identified as a key release pathway leading to environmental exposure to NPs. In this study, we investigated the chemical transformation of two ZnO-NPs and one hydrophobic ZnO-NP commercial formulation (used in personal care products), during anaerobic digestion of wastewater. Changes in Zn speciation as a result of postprocessing of the sewage sludge, mimicking composting/stockpiling, were also assessed. The results indicated that "native" Zn and Zn added either as a soluble salt or as NPs was rapidly converted to sulfides in all treatments. The hydrophobicity of the commercial formulation retarded the conversion of ZnO-NP. However, at the end of the anaerobic digestion process and after postprocessing of the sewage sludge (which caused a significant change in Zn speciation), the speciation of Zn was similar across all treatments. This indicates that, at least for the material tested, the risk assessment of ZnO-NP through this exposure pathway can rely on the significant knowledge already available in regard to other "conventional" forms of Zn present in sewage sludge.     

Rapeseed or linseed supplements in grass-based diets: Effects on milk fatty acid composition of Holstein cows over two consecutive lactations

Persistency of changes in milk fatty acid (FA) composition to 4 different oilseed supplements rich in cis-9 18:1 or 18:3n-3 was determined over 2 consecutive lactations in 58 and 35 Holstein cows during the first and second years, respectively. During the initial 5 wk of the study, all experimental cows were fed the same diet. Thereafter, cows received 1 of 5 treatments for 2 consecutive lactations, including the prepartum period. Treatments comprised the basal diet with no additional lipid, or supplements of extruded linseeds (EL), extruded rapeseeds (ER), cold-pressed fat-rich rapeseed meal (FRM), or whole unprocessed rapeseeds (WR). Oilseeds were offered to provide between 2.5 to 3.0% of additional oil in diet dry matter. During indoor periods, cows received a mixture (3:1, wt/wt) of grass silage and grass hay, whereas cows were at pasture during outdoor periods. Over the entire study, oilseed supplements decreased the concentration of milk FA synthesized de novo and increased 18:0 and cis-9 18:1 content, with a ranking of treatment responses (highest to lowest) of FRM, EL, ER, and WR. Irrespective of period, both EL and FRM increased total milk trans FA content, whereas WR resulted in lower concentrations in milk from grazing cows. Relative to rapeseed, EL resulted in higher increases in milk cis-12,cis-15,trans-12 to -16 18:1, nonconjugated trans 18:2 (especially ?11,15), and 18:3n-3. In contrast, rapeseed supplements resulted in a greater enrichment of cis-11 18:1, trans-4 to -9 18:1, and cis 20:1 than EL. Changes in milk FA composition to oilseeds were of greater magnitude during indoor than outdoor periods, where oilseed supplements often decreased cis-9,trans-11 conjugated linoleic acid content. During the second indoor period, both EL and ER resulted in higher total trans FA content, trans-10 18:1 in particular, than during the first indoor period, consistent with an interaction between dietary starch content and oilseed supplement. Overall, the extent of changes in milk FA composition were related to the nature (rapeseed or linseed) and form of oilseed (extruded, cold-pressed fat-rich meal or whole unprocessed), and their interactions with the composition of the basal diet (grass silage and hay or pasture; or dietary starch content). Milk FA responses were stable within each period and repeatable over both outdoor feeding periods, with extent of changes being comparable to reports from relatively short-term (1- to 3-mo) studies.     

Electronic Current Distribution Calculation for a Ni‐YSZ Solid Oxide Fuel Cell Anode

A simulation of a nickel‐yttrium stabilized zirconium oxide (Ni‐YSZ) solid oxide fuel cell cermet anode was used to determine the electronic current distribution within the percolating networks of nickel particles distributed in the electrode. The anode is simulated via a Monte–Carlo percolation model and current distribution is calculated via a relaxation algorithm. Nickel particle current densities are reported as a ratio to the total anode current density allowing results to be applied to any anode current density. Calculated current distributions were drastically affected by the volume percent of nickel as well as anode porosity. Experiments were performed to determine failure current densities of thin nickel wires to establish the relationship between critical current densities and surface area or volume of the wires. Both reducing and oxidizing environments were used for these measurements over a temperature range up to 800 °C.     

A comparison of different methods for assessing the features of eating disorders in patients with binge eating disorder.

The authors compared 3 methods for assessing the features of eating disorders in patients with binge eating disorder (BED). Participants were administered the Eating Disorder Examination (EDE) interview and completed the EDE Questionnaire (EDE-Q) at baseline. Participants prospectively self-monitored their eating behaviors daily for 4 weeks and then completed another EDE-Q. The EDE and the EDE-Q were significantly correlated on frequencies of objective bulimic episodes (binge eating) and on the Dietary Restraint, Eating Concern, Weight Concern, and Shape Concern subscales. Mean differences in the EDE and EDE-Q frequencies of objective bulimic episodes were not significant, but scores on the 4 subscales differed significantly, with the EDE-Q yielding higher scores. At 4 weeks, the EDE-Q retrospective 28-day assessment was significantly correlated with the prospective daily self-monitoring records for frequency of objective bulimic episodes, and the mean difference between methods was not significant. The EDE-Q and self-monitoring findings for subjective bulimic episodes and objective overeating differed significantly. Thus, in patients with BED, the 3 assessment methods showed some acceptable convergence, most notably for objective bulimic episodes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

New CMOS-compatible mechanical shear stress sensor

A new approach to the measurement of mechanical stresses is presented. The new sensor design utilizes the fact that shear stresses in the silicon lattice generate an electric field perpendicular to an electric current. The sensor effect is characterized by a new piezo-bridge-coefficient, which relates the sensitivity of the sensor structure to its crystallographic orientation. The sensor is based on a CMOS-compatible structure. It offers the possibility to realize highly sensitive single-element stress sensors for use in MEMS or in smart force measurement strips, as well. An example of a signal conditioning circuit is shown. Special designs with improved sensitivity and low noise are presented. The response to parasitic magnetic fields is measured and strongly reduced. Furthermore, the temperature behavior was analyzed and finally optimized     

Microstructural evolution in high purity aluminum processed by ECAP

High purity (99.99%) aluminum was processed by equal-channel angular pressing (ECAP) through 1–12 passes and examined using orientation imaging microscopy. The results reveal two distinct processing regimes: from 1 to 4 passes the microstructure evolves from elongated subgrains to an essentially equiaxed array of ultrafine grains and from 4 to 12 passes there is no measurable change in the average grain size and grain aspect ratio. The boundary misorientation angle and the fraction of high-angle boundaries increase rapidly up to 4 passes and at a slower rate from 4 to 12 passes. Anomalously large grains were visible in the central region of the billet pressed through 12 passes due to dynamic recovery and grain growth. The results suggest optimum processing is achieved by pressing through 4–8 passes.     

Block-based adaptive ROI for remote photoplethysmography

Remote photoplethysmography (rPPG) can achieve contactless human vital signs monitoring, but its signal quality is limited by the remote operation nature. In practical applications, improving the rPPG signal quality becomes an essential task. As a remote imaging technique, rPPG utilizes a camera to capture a video of a skin area, especially the facial area, then focuses on a particular sub-area as the region of interest (ROI). In this paper, we investigated a novel adaptive ROI (AROI) approach for improving the rPPG signal quality. In this approach, block-based spatial-temporal division is performed on a captured face video. Based on these segmented video pipelines, the spatial-temporal quality distribution of the rPPG signals is estimated using a signal-to-noise ratio (SNR) feature. Afterwards, AROIs are calculated through mean-shift clustering and adaptive thresholding in SNR maps. As the AROI can be dynamically adjusted according to the spatial-temporal quality distribution of rPPG signals on the face, the quality of the final recovered rPPG signal is improved. The performance of the proposed AROI approach was evaluated with both still and moving subjects. Compared to conventional ROI methods for rPPG, the proposed AROI obtained a higher accuracy in heart rate measurement. And the state-of-the-art motion-resistant rPPG techniques can be effectively enhanced through being integrated with the AROI.     

Optimization of a parallel permutation testing function for the SPRINT R package

The statistical language R and its Bioconductor package are favoured by many biostatisticians for processing microarray data. The amount of data produced by some analyses has reached the limits of many common bioinformatics computing infrastructures. High Performance Computing systems offer a solution to this issue. The Simple Parallel R Interface (SPRINT) is a package that provides biostatisticians with easy access to High Performance Computing systems and allows the addition of parallelized functions to R. Previous work has established that the SPRINT implementation of an R permutation testing function has close to optimal scaling on up to 512 processors on a supercomputer. Access to supercomputers, however, is not always possible, and so the work presented here compares the performance of the SPRINT implementation on a supercomputer with benchmarks on a range of platforms including cloud resources and a common desktop machine with multiprocessing capabilities. Copyright © 2011 John Wiley & Sons, Ltd.     

A complete temporal relational algebra

Various temporal extensions to the relational model have been proposed. All of these, however, deviate significantly from the original relational model. This paper presents a temporal extension of the relational algebra that is not significantly different from the original relational model, yet is at least as expressive as any of the previous approaches. This algebra employs multidimensional tuple time-stamping to capture the complete temporal behavior of data. The basic relational operations are redefined as consistent extensions of the existing operations in a manner that preserves the basic algebraic equivalences of the snapshot (i.e., conventional static) algebra. A new operation, namely temporal projection, is introduced. The complete update semantics are formally specified and aggregate functions are defined. The algebra is closed, and reduces to the snapshot algebra. It is also shown to be at least as expressive as the calculus-based temporal query language TQuel. In order to assess the algebra, it is evaluated using a set of twenty-six criteria proposed in the literature, and compared to existing temporal relational algebras. The proposed algebra appears to satisfy more criteria than any other existing algebra. Edited by Wesley Chu. Received February 1993 / Accepted April 1995