Determination of the Sodium Carbonate-Sulfur Dioxide Reaction Rate Coefficient at 450°F

Abstract

Gas-phase dispersion in granular biofilter materials with a wide range of particle sizes was investigated using atmospheric air and nitrogen as tracer gases. Two types of materials were used: (1) light extended clay aggregates (LECA), consisting of highly porous particles, and (2) gravel, consisting of solid particles. LECA is a commercial material that is used for insulation, as a soil conditioner, and as a carrier material in biofilters for air cleaning. These two materials were selected to have approximately the same particle shape. Column gas transport experiments were conducted for both materials using different mean particle diameters, different particle size ranges, and different gas flow velocities. Measured breakthrough curves were modeled using the advection-dispersion equation modified for mass transfer between mobile and immobile gas phases. The results showed that gas dispersivity increased with increasing mean particle diameter for LECA but was independent of mean particle diameter for gravel. Gas dispersivity also increased with increasing particle size range for both media. Dispersivities in LECA were generally higher than for gravel. The mobile gas content in both materials increased with increasing gas flow velocity but it did not show any strong dependency on mean particle diameter or particle size range. The relative fraction of mobile gas compared with total porosity was highest for gravel and lowest for LECA likely because of its high internal porosity.     

Infill McMansions: Style and the psychophysics of size

The number and size of infill oversized houses, or McMansions, has increased in the U.S. and the world. To maintain desirable neighborhood appearances, communities should know what constitutes “too big.” This paper reports six studies that used color simulations of blocks of houses to examine compatibility and visual appeal in relation to attributes of the infill house and its context. Following psychophysical findings, the relative size of the infill house should have larger effects on response than its actual size. The studies confirmed that the infill ratio had more weight than size for perceived compatibility. Compatibility did not always translate into visual appeal. For visual appeal, infill style had larger effects than did size or size ratio, height had larger effects than width, and, for larger sizes and ratios, infill ratio had larger effects than actual size. To maintain visual quality in relation to infill houses, communities should first seek an architecturally compatible style, and then try to control its relative size (the infill façade area). Tests of responses to real infill houses can show how well these findings generalize.     

Near-surface monitoring for the ZERT shallow CO2 injection project

As part of a collaborative effort operated by the Zero Emission Research and Technology Center (ZERT), a series of two shallow releases of CO₂ was performed at a test site in Bozeman, MT. The purpose of the experiment was to simulate possible leakage scenarios from a carbon capture and storage operation in order to further develop and verify monitoring technologies used to characterize and quantify the release of CO₂. The project included collaboration with several research groups and organizations. Presented here are the results of soil–gas monitoring conducted by researchers from the National Energy Technology Laboratory, including CO₂ flux measurement, soil–gas analysis, perfluorocarbon tracer monitoring, and soil resistivity measurements. Together, these methods proved to be effective in detecting and characterizing leakage in the near-surface.     

Seasonal profiles of leaf ascorbic acid content and redox state in ozone-sensitive wildflowers

Cutleaf coneflower (Rudbeckia laciniata L.), crown-beard (Verbesina occidentalis Walt.), and tall milkweed (Asclepias exaltata L.) are wildflower species native to Great Smoky Mountains National Park (U.S.A.). Natural populations of each species were analyzed for leaf ascorbic acid (AA) and dehydroascorbic acid (DHA) to assess the role of ascorbate in protecting the plants from ozone stress. Tall milkweed contained greater quantities of AA (7-10 micromol g(-1) fresh weight) than crown-beard (2-4 micromol g(-1) fresh weight) or cutleaf coneflower (0.5-2 micromol g(-1) fresh weight). DHA was elevated in crown-beard and cutleaf coneflower relative to tall milkweed suggesting a diminished capacity for converting DHA into AA. Tall milkweed accumulated AA in the leaf apoplast (30-100 nmol g(-1) fresh weight) with individuals expressing ozone foliar injury symptoms late in the season having less apoplast AA. In contrast, AA was not present in the leaf apoplast of either crown-beard or cutleaf coneflower. Unidentified antioxidant compounds were present in the leaf apoplast of all three species. Overall, distinct differences in antioxidant metabolism were found in the wildflower species that corresponded with differences in ozone sensitivity.     

Parental supervision of teenage drivers in a graduated licensing system

OBJECTIVES: Most states now have lengthy learner periods for young, beginning drivers as part of their graduated driver licensing (GDL) systems. Although parents play a vital role during the learner stage of GDL by supervising driving practice, virtually nothing is known about the nature and quality of parental supervision. The objectives of this study were to investigate parents' supervisory behavior and parent-teen relationships during the learner stage of graduated licensing and to evaluate two approaches for assisting parents in supervising their teenager's early driving experience. METHODS: Families of teenagers applying for a learner permit received either a booklet describing highly structured practice sessions for beginning drivers, a series of "tip sheets" offering more generalized guidance, or no special materials. Questionnaires were sent separately to parents and teenagers three to six months after teenagers obtained their permit. RESULTS: Of 1,190 participating families, 653 parents (55%) and 609 teenagers (51%) responded. Both parents and teenagers perceived parents as supportive and helpful during driving sessions. Parents often demonstrated positive behaviors, such as complimenting their teenager and pointing out possible hazards; they also exhibited less desirable behaviors, such as raising their voice, but these were less frequent. A majority of parents (71%) and teenagers (52%) reported that they enjoyed spending this time together. About four months after obtaining a permit, most parents believed their teenager did not yet have enough experience and was not ready to drive unsupervised. Although the reported behaviors are encouraging, within-family agreement was low on most items. Finally, efforts to assist parents proved unsuccessful. Although parents thought the booklet and tip sheets were helpful, most used these materials only in a general way. CONCLUSIONS: The extended learning experience required by GDL programs is a positive experience for many families. However, finding a method for helping parents achieve maximum benefits during this process will be challenging. The results also suggest that current requirements in the learner phase of most state GDL systems (six months; 30-50 hours) may be inadequate to ensure that teenagers obtain a sufficient amount of experience to begin driving safely on their own.     

Air emission inventories in North America: a critical assessment

Although emission inventories are the foundation of air quality management and have supported substantial improvements in North American air quality, they have a number of shortcomings that can potentially lead to ineffective air quality management strategies. Major reductions in the largest emissions sources have made accurate inventories of previously minor sources much more important to the understanding and improvement of local air quality. Changes in manufacturing processes, industry types, vehicle technologies, and metropolitan infrastructure are occurring at an increasingly rapid pace, emphasizing the importance of inventories that reflect current conditions. New technologies for measuring source emissions and ambient pollutant concentrations, both at the point of emissions and from remote platforms, are providing novel approaches to collecting data for inventory developers. Advances in information technologies are allowing data to be shared more quickly, more easily, and processed and compared in novel ways that can speed the development of emission inventories. Approaches to improving quantitative measures of inventory uncertainty allow air quality management decisions to take into account the uncertainties associated with emissions estimates, providing more accurate projections of how well alternative strategies may work. This paper discusses applications of these technologies and techniques to improve the accuracy, timeliness, and completeness of emission inventories across North America and outlines a series of eight recommendations aimed at inventory developers and air quality management decision-makers to improve emission inventories and enable them to support effective air quality management decisions for the foreseeable future.     

Perceived Discomfort and Electromyographic Activity of the Upper Trapezius While Working at a VDT Station

Ten female participants performed work at a video display terminal (VDT) station over a whole working day. Subjective local muscular fatigue was evaluated by means of the Category Ratio 10 scale. Electromyographic activity of the upper right and left trapezius was measured. A comparison was made between 5 participants who had previous complaints and 5 participants who reported no musculoskeletal problems in the shoulder-neck region. The subjective scores for the shoulder differed significantly between the two groups, being higher for the group with complaints. Both groups showed a decrease in discomfort after the lunch break. The activity of the trapezius increased significantly for both groups, in a more pronounced way for the group with disorders. Although it is found in literature that VDT work is a task with very low static loads, it seems from this study that the EMG activity increase can be an indication of muscle fatigue: More effort was required to accomplish the same VDT task at the end of the day.     

Creating affordable Internet map server applications for regional scale applications

This paper presents an overview and process for developing an Internet Map Server (IMS) application for a local volunteer watershed group using an Internal Internet Map Server (IIMS) strategy. The paper illustrates that modern GIS architectures utilizing an internal Internet map server coupled with a spatial SQL command language allow for rapid development of IMS applications. The implication of this approach means that powerful IMS applications can be rapidly and affordably developed for volunteer organizations that lack significant funds or a full time information technology staff.     

Linking workplace incivility to citizenship performance: The combined effects of affective commitment and conscientiousness

Although all human relationships are believed to generally adhere to the basic tenets of social exchange theory, recent research suggests that exchange processes may vary as a function of individual differences. We tested this possibility by examining whether the effects of uncivil workplace exchanges on employee attitudes and behavior were moderated by conscientiousness. Using matched data from 190 job incumbents and their supervisors, we found (i) the effect of workplace incivility on citizenship performance to be transmitted through affective commitment and (ii) the strength of this effect to depend on individual differences in conscientiousness. As such, the overall pattern of relationships supported moderated mediation, in that, the indirect effect of workplace incivility on citizenship performance through affective commitment was stronger for individuals high (as compared with those low) in conscientiousness. These findings broaden the focus of prior research by illustrating that, in addition to the mediating effects of cognitive and stress‐based factors, social exchange processes are important for understanding incivility's adverse effects on citizenship performance and that such exchanges are moderated by individual differences in conscientiousness. Copyright © 2011 John Wiley & Sons, Ltd.