An evaluation of a pilot-scale nonthermal plasma advanced oxidation process for trace organic compound degradation

This study evaluated a pilot-scale nonthermal plasma (NTP) advanced oxidation process (AOP) for the degradation of trace organic compounds such as pharmaceuticals and potential endocrine disrupting compounds (EDCs). The degradation of seven indicator compounds was monitored in tertiary-treated wastewater and spiked surface water to evaluate the effects of differing water qualities on process efficiency. The tests were also conducted in batch and single-pass modes to examine contaminant degradation rates and the remediation capabilities of the technology, respectively. Values for electrical energy per order (EEO) of magnitude degradation ranged from <0.3 kWh/m³-log for easily degraded compounds (e.g., carbamazepine) in surface water to 14 kWh/m³-log for more recalcitrant compounds (e.g., meprobamate) in wastewater. Changes in the bulk organic matter based on UV₂₅₄ absorbance and excitation-emission matrices (EEM) were also monitored and correlated to contaminant degradation. These results indicate that NTP may be a viable alternative to more common AOPs due to its comparable energy requirements for contaminant degradation and its ability to operate without any additional feed chemicals.     

The socio-political economy of nuclear power development in Japan and South Korea

This paper analyzes the socio-cultural, political and economic conditions prevalent during the inception of nuclear power programs in Japan and South Korea in order to identify commonalities which support nuclear power program expansion. The study identifies six factors as having a clear influence on supporting nuclear power development: (1) strong state involvement in guiding economic development; (2) centralization of national energy policymaking and planning; (3) campaigns to link technological progress with national revitalization; (4) influence of technocratic ideology on policy decisions; (5) subordination of challenges to political authority, and (6) low levels of civic activism. The paper postulates that insights from this study can be used to assess the propensity of nations which have the emergent capacity to support nuclear power development to actually embark on such programs.     

An end-to-end tool chain for Sensory Experience based on MPEG-V

This paper provides an overview of our research conducted in the area of Sensory Experience including our implementations using MPEG-V Part 3 entitled “Sensory Information”. MPEG-V Part 3 introduces Sensory Experience as a tool to increase the Quality of Experience by annotating traditional multimedia data with sensory effects. These sensory effects are rendered on special devices like fans, vibration chairs, ambient lights, scent disposers, water sprayers, or heating/cooling devices stimulating senses beyond the traditional ones. The paper's main focus is on the end-to-end aspects including the generation, transmission, and synchronized rendering of sensory effects with the traditional multimedia data taking movie clips as an example. Therefore, we present in this paper an open source tool chain that provides a complete end-to-end sensory effect generation and consumption framework. Furthermore, we summarize results from various subjective quality assessments conducted in this area. Finally, we point out research challenges that may encourage further research within this emerging domain.     

A deterministic model for the occurrence and dynamics of multiple mutations in hierarchically organized tissues

Cancers are rarely caused by single mutations, but often develop as a result of the combined effects of multiple mutations. For most cells, the number of possible cell divisions is limited because of various biological constraints, such as progressive telomere shortening, cell senescence cascades or a hierarchically organized tissue structure. Thus, the risk of accumulating cells carrying multiple mutations is low. Nonetheless, many diseases are based on the accumulation of such multiple mutations. We model a general, hierarchically organized tissue by a multi-compartment approach, allowing any number of mutations within a cell. We derive closed solutions for the deterministic clonal dynamics and the reproductive capacity of single clones. Our results hold for the average dynamics in a hierarchical tissue characterized by an arbitrary combination of proliferation parameters. We show that hierarchically organized tissues strongly suppress cells carrying multiple mutations and derive closed solutions for the expected size and diversity of clonal populations founded by a single mutant within the hierarchy. We discuss the example of childhood acute lymphoblastic leukaemia in detail and find good agreement between our predicted results and recently observed clonal diversities in patients. This result can contribute to the explanation of very diverse mutation profiles observed by whole genome sequencing of many different cancers.     

Impact of surrounding tissue on conductance measurement of coronary and peripheral lumen area

Parallel conductance (electric current flow through surrounding tissue) is an important determinant of accurate measurements of arterial lumen diameter, using the conductance method. The present study is focused on the role of non-uniform geometrical/electrical configurations of surrounding tissue, which are a primary source of electric current leakage. Computational models were constructed to simulate the conductance catheter measurement with two different excitation electrodes spacings (i.e. 12 and 20 mm for coronary and peripheral sizing, respectively) for different vessel–tissue configurations: (i) blood vessel fully embedded in muscle tissue, (ii) blood vessel superficially embedded in muscle tissue, and (iii) blood vessel superficially embedded in muscle tissue with fat covering half of the arterial vessel (anterior portion). The simulations suggest that the parallel conductance and accuracy of measurement is dependent on the inhomogeneous/anisotropic configuration of surrounding tissue, including the asymmetric dimension and anisotropy in electrical conductivity of surrounding tissue. Specifically, the measurement was shown to be accurate as long as the vessel was superficial, regardless of the considerable total surrounding tissue dimension for coronary or peripheral arteries. Moreover, it was shown that the unfavourable impact of parallel conductance on the accuracy of conductance catheter measurement is decreased by the combination of a lower transverse electrical conductivity of surrounding muscle tissue, a smaller electrode spacing and a larger lumen diameter. The present findings confirm that the conductance catheter technique provides an accurate platform for sizing of clinically relevant (i.e. superficial and diseased) arteries.     

Landscape and flow path-based nutrient loading metrics for evaluation of in-stream water quality in Saginaw Bay,Michigan

Landscape metrics are often used to model nonpoint source pollution from agricultural and urban surface runoff. By considering topography and the spatial arrangement of land cover, landscape metrics can better account for hydrologic connectivity, loading quantity, and vegetated buffer filtering between nutrient loading sources and streams. For this study we develop a surface runoff nutrient loading metric that considers source (i.e. cropland or developed) loading and buffer filtering along hydrologic transport vectors, or flow paths. We use General Additive Modeling to evaluate the relationship between this metric and in-stream nitrogen (N) and phosphorus (P) concentrations in the Saginaw Bay watershed in Michigan, US and compare the relative predictive power between this metric and other landscape metrics that do not consider hydrologic connectivity. The flow path-based cropland loading metric was a stronger predictor of in-stream NO₃ concentrations than alternative metrics. In-stream P concentrations were best predicted by models that included 48-h antecedent precipitation and catchment-wide proportion of developed landcover. Metric maps reveal high nutrient loading areas where only a small proportion of loading reaches streams via surface runoff, highlighting the need to consider nutrient loading via drainage tiles and other subsurface pathways in efforts to quantify nonpoint source loading to surface waters. The flow path-based loading metric is represented spatially as a gridded dataset showing estimates of nutrient loading adjacent to streams, and with higher resolution stream delineation data it could be used by land managers to target locations for precision buffer placement to intercept surface runoff and reduce nutrient loading.     

SYNTHESIS FACTORS THAT IMPACT TiO2 NANOTUBE ACTIVITY DURING GAS-PHASE PHOTOCATALYTIC OXIDATION OF METHANOL

Statistically designed experiments determined which steps in the hydrothermal synthesis of TiO₂ nanotubes significantly impacted the rate of photocatalytic oxidation of gas-phase methanol. This study investigated the following synthesis steps: sodium hydroxide treatment time, conductivity of the first and second washings, acid treatment time and pH, calcination temperature, and H₂O₂ post-treatment. The synthesis procedure produced a highly active photocatalyst; the maximum catalyst activity of the TiO₂ nanotubes was approximately seven times that of the starting material, Degussa P-25. Characterization with transmission electron microscopy, X-ray diffraction, and temperature-programmed oxidation revealed that the nanotubes were 10–12 nm in diameter with an average length of approximately 100 nm.     

An examination of different fitness and novelty based selection methods for the evolution of neural networks

It has been suggested recently that it is a reasonable abstraction of evolutionary processes to use evolutionary algorithms that select individuals based on the novelty of their behavior instead of their fitness. Here we study the performance of fitness- and novelty-based search on several neuroevolution tasks. We also propose several new algorithms that select both for fit and for novel individuals, but without weighting these two criteria directly against each other. We find that behavioral speciation, behavioral near neutral speciation, and behavioral novelty speciation perform best on most tasks. Pure novelty search, as well as a number of hybrid methods without speciation mechanism, do not perform well on most tasks. Using behavioral criteria for speciation often yields better results than using genetic criteria.     

Electrostatic charging during the flow of grains from a cylinder

Electrostatic charging is ubiquitous in granular processing, leading to problems of safety, jamming and unwanted material segregation. To better understand the mechanics of granular charging, we focus here on flow through a metal cylinder, where we can isolate charging regions near the cylinder walls from noncharging regions further away. We confirm that monodisperse grains charge in proportion to the area of contact between grains and the cylinder walls, and so in large cylinders, most particles remain almost uncharged. Those particles that do charge reach a plateau charge density after filling the cylinder and flowing past the walls a distance of less than one and a half centimeters. For bidisperse granular blends, the net charge produced by the mixture is dominated by the component that comes into contact with the walls of the apparatus. This is found to be caused by segregation effects as well as the coating of the larger particles by the smaller ones. We make use of these results to predict the charge generated in mass flow hoppers, and we test these predictions. Finally we examine the effect of grounding the experimental apparatus, and we find that paradoxically, grounding does not prevent charge accumulation.     

Perceive-decide-act, perceive-decide-act: How abstract is repetition-related decision learning?

Recent encounters with a stimulus often facilitate or “prime” future responses to the same or similar stimuli. However, studies are inconclusive as to whether changing the response that is required attenuates priming only for identical stimuli, or also for categorically related items. In 2 object priming experiments, the authors show that priming was eliminated if the initial decision associated with a stimulus changed on a later trial. This disruption of priming extended to perceptually and conceptually similar object exemplars and was found even when the classification tasks were uncorrelated with one another, many other items had intervened, and after only 1 prior encounter with a given stimulus. These outcomes are consistent with the rapid and automatic binding of a stimulus with a response into an episodic “instance” or “event file” and demonstrate that repetition-related decision learning is not hyperspecific but generalizes to new stimuli. (PsycINFO Database Record (c) 2011 APA, all rights reserved)