984 research outputs found

    Nonanoic Acid Exhibits Inconsistency Between Bulk and Surface pKa

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    Mathematical and Physical Sciences (The Ohio State University Spring Undergraduate Research Expo)Organic molecules at the ocean surface influence the climate through their reactions as coatings on sea spray aerosols, although many complex processes have not yet been fully described. By further characterizing molecules at this surface, climate effects through aerosol processes could be deduced. One common organic at the ocean surface is nonanoic acid (NA), which may be formed via the oxidation of oleic acid by gas phase species such as ozone. The pKa for an acid is characteristic and gives insight into its reactivity, but its value at the air-water interface is not necessarily the same as in bulk solution (~4.8 for many organic acids). The reactivity of sea-surface carboxylic acids cannot be well predicted without an accurate value of surface pKa. By varying pH via titration and simultaneously measuring the surface tension of a NA solution via a Wilhelmy platinum plate, the surface pKa of NA can be obtained. The surface pKa of NA would be shown on the titration curve of surface tension versus pH as the inflection point. At pH 12, NA is ionized and its surface tension is 70.68 mN/m, near that of neat water (72.80 mN/m). At pH 3, the surface tension of NA is 30.49 mN/m, showing an increase in surface activity. Additionally, Brewster angle microscopy (BAM) will be used in the future to image NA at the surface at different pH values. With an accurate pKa and visual evidence of the surface activity of nonanoic acid, the atmospheric impact of aerosols could be further described. Investigation of this inconsistency is a first step to better predict climate change.CAICE, a National Science Foundation Center for Chemical Innovation (CHE-1305427)Academic Major: Chemistr

    Late Cretaceous crinoids (Echinodermata) from the southwestern margin of the Holy Cross Mts. (southern Poland) and phylogenetic relationships among bourgueticrinids

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    A systematic account of crinoids from the Upper Coniacian–Lower Campanian of the southwestern margin of the Holy Cross Mountains in southern Poland is presented. Seven crinoid taxa [Marsupites testudinarius (von Schlotheim), Bourgueticrinus ellipticus (Miller), Bourgueticrinus sp., I.? granosus Valette, Isocrinus? sp., Nielsenicrinus carinatus Roemer and Austinocrinus bicoronatus (von Hagenow)] are described and illustrated. The new material from Poland extends down the stratigraphic range of Austinocrinus bicoronatus to the Lower Campanian. Morphometric data support that Bourgueticrinus ellipicus and B.? suedicus are conspecific. Taphonomy and paleoecology of recorded crinoid assemblages are discussed. Phylogeny of Cretaceous bourgueticrinids is also revisited

    Workplace Dispute Resolution and Gender Inequality

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    Despite substantial bodies of research on employment differentials between women and men and on conflict in the workplace, little prior research links the two. This article summarizes preliminary results of a study which attempts to fill this knowledge gap. We conceive of workplace disputes as having origins, processes, and outcomes. We theorize that these three components are patterned by sex roles, sex segregation of jobs, and work structures (unions, firms, industries). Our findings indicate that workplace jurisprudence operates differentially for women and men employees, as hypothesized. The results suggest linkages to other aspects of employment inequality and provide a theoretical framework for further research and policy making

    Epiphytic ant-plant obtains nitrogen from both native and invasive ant inhabitants

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    Ant-plants have been extensively used as model systems in the study of the evolution and ecology of mutualisms. Using a 15N isotope labeling experiment, we found that both a native ant mutualist (Philidris cordata) and an invasive ant (Pheidole megacephala) provide nitrogen to the Australian ant-plant Myrmecodia beccarii

    Epiphytic ant-plant obtains nitrogen from both native and invasive ant inhabitants

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    Ant-plants have been extensively used as model systems in the study of the evolution and ecology of mutualisms. Using a 15N isotope labeling experiment, we found that both a native ant mutualist (Philidris cordata) and an invasive ant (Pheidole megacephala) provide nitrogen to the Australian ant-plant Myrmecodia beccarii

    Ideology and scientific credibility: environmental policy in the American Pacific Northwest

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    In the later years of the twentieth century and into the twenty-first century, there has been an increasing emphasis among many decision-makers, interest groups, and citizens about the importance of science-based environmental policy. The assumption is that scientists can facilitate the resolution of public environmental decisions by providing scientific information to policymakers and the public, and by becoming more directly involved in policy arenas than they have traditionally been. However, at the same time, there are those who question the value of science, especially for ideological reasons. This study empirically examines the impact of ideology on attitudes toward science, scientific research, and scientists among various environmental policy participants. The data utilized to investigate these orientations were collected from surveys of five different groups involved in environmental policy and management in the Pacific Northwest including ecological scientists at universities and federal agencies; natural resource and environmental managers of state and federal programs; members of interest groups (e.g., environmental groups, industry associations, etc.); the “attentive public” (i.e., citizens who have participated in the environmental policy process); and the general public. Preliminary results reveal significant differences between liberals and conservatives in their orientations toward science, with self-identified liberals generally more likely to see science and scientists as objective and conservatives having a contrary view

    Using Elicited Choice Probabilities to Estimate Random Utility Models: Preferences for Electricity Reliability

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    When data on actual choices are not available, researchers studying preferences sometimes pose choice scenarios and ask respondents to state the actions they would choose if they were to face these scenarios. The data on stated choices are then used to estimate random utility models, as if they are data on actual choices. Stated choices may differ from actual ones because researchers typically provide respondents with less information than they would have facing actual choice problems. Elicitation of choice probabilities overcomes this problem by permitting respondents to express uncertainty about their behavior. This paper shows how to use elicited choice probabilities to estimate random utility models with random coefficients and applies the methodology to estimate preferences for electricity reliability in Israel.

    Collection efficiency and design of microbial air samplers

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    The variables affecting the physical collection efficiency of air samplers of the type that impact microbe-carrying particles onto agar were investigated using a simplified analytical method and computational fluid dynamics. The results from these two techniques were compared, as were the effect of jet velocity, nozzle size, and nozzle distance from the agar surface; also considered was the optimisation of these variables to obtain an efficient design of sampler. A technique is described that calculates the proportion of microbe-carrying particles that a sampler will collect from a typical size distribution of microbe-carrying particles found in an occupied room; the three air samplers studied were found to collect from about 22% to over 99% of the micro-organisms in the room air

    Ophiuroids Discovered in the Middle Triassic Hypersaline Environment

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    Echinoderms have long been considered to be one of the animal phyla that is strictly marine. However, there is growing evidence that some recent species may live in either brackish or hypersaline environments. Surprisingly, discoveries of fossil echinoderms in non-(open)marine paleoenvironments are lacking. In Wojkowice Quarry (Southern Poland), sediments of lowermost part of the Middle Triassic are exposed. In limestone layer with cellular structures and pseudomorphs after gypsum, two dense accumulations of articulated ophiuroids (Aspiduriella similis (Eck)) were documented. The sediments with ophiuroids were formed in environment of increased salinity waters as suggested by paleontological, sedimentological, petrographical and geochemical data. Discovery of Triassic hypersaline ophiuroids invalidates the paleontological assumption that fossil echinoderms are indicators of fully marine conditions. Thus caution needs to be taken when using fossil echinoderms in paleoenvironmental reconstructions
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