Eliminating inhibition of return by changing salient nonspatial attributes in a complex environment.

Inhibition of return (IOR) occurs when a target is preceded by an irrelevant stimulus (cue) at the same location: Target detection is slowed, relative to uncued locations. In the present study, we used relatively complex displays to examine the effect of repetition of nonspatial attributes. For both color and shape, attribute repetition produced a robust inhibitory effect that followed a time course similar to that for location-based IOR. However, the effect only occurred when the target shared both the feature (i.e., color or shape) and location with the cue; this constraint implicates a primary role for location. The data are consistent with the idea that the system integrates consecutive stimuli into a single object file when attributes repeat, hindering detection of the second stimulus. The results are also consistent with an interpretation of IOR as a form of habituation, with greater habituation occurring with increasing featural overlap of a repeated stimulus. Critically, both of these interpretations bring the IOR effect within more general approaches to attention and perception, rather than requiring a specialized process with a limited function. In this view, there is no process specifically designed to inhibit return, suggesting that IOR may be the wrong framing of inhibitory repetition effects. Instead, we suggest that repetition of stimulus properties can interfere with the ability to focus attention on the aspects of a complex display that are needed to detect the occurrence of the target stimulus; this is a failure of activation, not an inhibition of processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Carbon dioxide (CO2) storage and sequestration of land cover in the Leyte Geothermal Reservation

This study estimated the existing stored carbon (C) and rate of sequestration by vegetation that can potentially serve as a sink for the carbon dioxide emitted from eight geothermal plants in Leyte Geothermal Reservation, Philippines. For the 20,438 ha watershed in the vicinity of the power project, the total C storage is 3.84 Mt C (14.10 Mt CO₂) while C sequestration based on biomass change was 47.35 kt C (173.77 kt CO₂). Relative to power plant emission, the C stored in the reserve is equivalent to more than 22 years of CO₂ emission. Annual C sequestration is 27% of CO₂ emission per year. For the next 25 years, two scenarios were projected. Under Scenario I (“Business as Usual”), the forest reserve will be able to store and sequester more than 32 years of CO₂ emission from the power plants. Under Scenario II (“Accelerated Reforestation”), the reserve will be able to store and sequester about 34 years of CO₂ emission.In addition, the rate of C sequestration based on biomass change in vegetation was recorded to assess the optimum land use that can absorb the carbon dioxide emitted by the power project. These are as follows: tree plantations (10.09 tC/ha/yr)>coconut (4.78 tC/ha/yr)>brushland (4.29 tC/ha/yr)>natural forest (0.92 tC/ha/yr).In terms of cost, the power project operator is spending P1.22 per t CO₂ (P4.4 or US$0.12 per tC) for every year of C storage and sequestration. For 25 years, the total cost is P30.40 per tCO₂ (P111.5 or US$2.94 per tC) which is comparable to the cost of C offset in other tropical countries.     

DSC study of foamable poly (vinyl chloride‐co‐vinyl acetate) plastisols of different commercial plasticizers

In this article the characterization of the thermal behavior of foamable PVC (Poly (vinyl chloride)) plastisols from 20 different plasticizers has been studied by differential scanning calorimetry (DSC). The interactions between the resin and the plasticizer as well as the decomposition of the azodicarbonamide (ADC)—the chemical blowing agent (CBA) used—have been analyzed. The latter process is of crucial importance for the knowledge of plasticized PVC flexible foam formation. Clear effects of the chemical nature of the plasticizers and their molecular weight (M_w) have been observed, both in the interactions (swelling and early stages of gelation) between the resin and the plasticizer, as well as in the temperature of the ADC decomposition and the shape of the DSC peak. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Effect of Water Jet Cutting and Moderate Heat Treatment on Quality of Fresh-Cut Red Oak Leaf Lettuce (Lactuca sativa L. var. crispa)

Fresh-cut red oak leaf lettuce was produced by six different processing lines in order to assess the effect of water jet cutting (nozzle diameter 0.1 mm, pressure 2,500 bar) versus blade cutting as well as washing with cold and warm water (4 and 45 °C, 120 s) prior to and after shredding, respectively. Throughout refrigerated storage (4 °C, 12 days), O₂ and CO₂ levels in the modified atmosphere of the consumer-sized sample bags were monitored, and fresh-cut products and process water were subjected to microbiological analysis. As further quality parameters, phenylalanine ammonia lyase (PAL) activity as well as levels of chlorophyll a and b, β-carotene and cyanidin 3-O-(6”-O-malonyl)-glucoside were determined by HPLC with diode array detection (HPLC-DAD) and HPLC coupled with diode array detection and tandem mass spectrometry (HPLC-DAD-MSⁿ) throughout storage. Additionally, visual appearance and cut edge browning were assessed by sensorial evaluation and stereo microscopy on storage day 8. Microbiological quality throughout commercial shelf life was best retained by warm water washing of shredded lettuce. Furthermore, moderate heat treatment significantly reduced PAL activity and cut edge browning without affecting pigment contents and vitality of the lettuce tissue. Additionally, warm water treatment significantly lowered the microbial load in the process water. Throughout storage, water jet cutting did not affect the microbial, physiological and sensorial fresh-cut lettuce quality compared to blade cutting using a newly sharpened blade, thus indicating a similar degree of wounding due to the cutting techniques applied. The application of a pre-washing step prior to shredding was found to be suitable to reduce the risk of cross-contamination in subsequent process steps.     

Flüssigkeitsring-Vakuumpumpen

Liquid ring vacuum pumps – Oldtimers of vacuum technology and yet highly up-to-date Liquid ring vacuum pumps were developed over a hundred years ago. In the meantime, vacuum technology has evolved considerably and offers optimum economic and technical solutions for a wide variety of applications. However, liquid ring vacuum technology still has its reason for existence and is the most suitable principle for vacuum generation in some applications. Thanks to its functionality it is perfectly suited for the extraction of humid gases or vapours. Due to the use of process-compatible operating fluid and the possibility of different construction materials, it can be perfectly matched to different operating fluids and process conditions. In addition, it is available in many sizes on the market and can therefore extract very small and very high quantities of gas and vapour.     

Contrast between steady and time-averaged unsteady combustion simulations

Time-averaged predictions from unsteady solutions of the two-dimensional Navier–Stokes equations are contrasted with Reynolds-averaged results for a reacting flow problem in a high pressure combustor. The goal is to determine whether the two-dimensional unsteady approximation can be useful as an engineering analysis in problems for which time-averaged quantities are of primary interest. The conditions are taken from an experiment in which non-premixed gaseous oxygen and hydrogen were injected into a combustion chamber through coaxial channels. The resulting flowfield is dominated by a large recirculation zone arising from the back-step created by the injector. The results of steady and time-averaged, unsteady solutions are strikingly different. The unsteady simulation produces strong unsteady structures whose time-averaged results lead to a much wider flame zone, a different recirculation zone structure, and a substantially different wall heat flux than those obtained with a steady RANS procedure. The time-averaged calculations yield the correct combustor chamber pressure and compare considerably more favorably with heat flux measurements than do the RANS results. The two-dimensional approximation, however, overstates the unsteady vortex roll up and precludes large scale mixing across the axis of symmetry, thereby giving deficient predictions near the centerline. Overall, the present results indicate that capturing large-scale unsteady characteristics can provide more accurate predictions of recirculation dominated reacting flows and suggest that two-dimensional, time-averaged solutions represent a potentially useful engineering tool for problems of this nature while also serving as a precursor for full three-dimensional simulations.     

A Bayesian assessment of tumour prevalence in brown bullhead and white sucker from the Canadian waters of the Great Lakes

Liver and skin tumours in brown bullhead (Ameiurus nebulosus) and white sucker (Catostomus commersoni) have been associated with contamination of the aquatic environment. In this study, we present a Bayesian hierarchical logistic-Bernoulli framework that considers the role of fish covariates (e.g., age, total weight, gonad weight, liver weight, fork length) on tumour prevalence to identify the presence of “hot-spots” around the Canadian waters of the Great Lakes, where high fish tumour frequencies are registered. We developed methods to discern the degree of impairment that are either based on the comparison of tumour frequencies in contaminated (or impacted) sites against those predicted in their corresponding reference areas, or the assessment of the prevailing conditions in impaired sites independently, without the need to establish baseline conditions for comparison purposes. Our modelling study predicts low frequencies of neoplastic tumours in all the impacted locations. In contrast, the same comparisons with the preneoplastic lesions provided evidence of distinct differences between impacted and reference sites in Jackfish Bay, St. Mary’s River, Niagara River, Hamilton Harbour, and Bay of Quinte. We also found weak to moderately strong relationships between tumour occurrence and fish physical characteristics that varied considerably in terms of their strength and nature (sign) among the different locations. Our study concludes that the prevalence of neoplastic tumours appears to have reached acceptable levels around the Great Lakes, but the distinctly higher levels of preneoplasms in several impacted locations underscore the need to improve our understanding of the lesions that may lead to carcinogenesis.     

青稞酒发酵过程中生物胺动态变化

对青稞酒发酵过程中生物胺的动态变化规律进行研究。利用氨基酸自动分析液相色谱法测定青稞酒不同发酵阶段中7种生物胺的含量,来评价发酵环境以及控制合理发酵过程和发酵终产物的质量。结果表明：青稞原料中不含组胺,但是青稞酒醅及成品青稞酒中都含有组胺。传统发酵和多菌种发酵两种发酵方式青稞酒的生物胺含量变化规律是：腐胺及胍丁胺的含量变化随着发酵的进行呈下降趋势;组胺及酪胺的含量随发酵进程逐渐上升,尤其是酪胺,上升趋势明显,多菌种发酵由2.98μg/g上升至5.36μg/g,传统发酵由5.97μg/g 上升至11.67μg/g。其余各种生物胺含量变化不明显,发酵过程的生物胺总量变化也不显著。本实验检测的青稞酒醅中的生物胺总量范围在53.44～72.56μg/g,不存在生物胺安全问题。     

Density Functional Study of the Effects of Strains on the Adsorption of Methoxide and its Decomposed Intermediates on Cu(100) Surface

Periodic density functional slab models were used to investigate adsorption of methoxide and its decomposed intermediates on optimized and strained (?5% to +5%) Cu(100) surfaces. Surface relaxation energies and adsorption energies of methoxide and its decomposed intermediates were systematically studied and quantified. Reaction energetics of methoxide C–H and C–O bond breaking were quantified on the strained Cu(100) surfaces.