Extraction and pre-concentration of platinum and palladium from microwave-digested road dust via ion exchanging mesoporous silica microparticles prior to their quantification by quadrupole ICP-MS

We report on the use of mesoporous silica microparticles (mu Ps) functionalized with quarternary amino groups for the isolation of platinum and palladium tetrachloro complexes from aqueous road dust digests. The mu Ps have a size ranging from 450 to 850 nm and are suspended directly in the aqueous digests, upon which the anionic Pt and Pd complexes are retained on the cationic surface. Subsequently, the mu Ps are separated by centrifugation. Elements that cause spectral interferences in ICP-MS determination of Pt and Pd can be quantitatively removed by adding fresh 0.240 mol L-1 HCl to the mu Ps and by repeating the centrifugation step. The analyte-loaded mu Ps are then dissolved in 0.1 mL of 2 mol L-1 HF, diluted to 2 mL, and the solutions thus obtained are analyzed by quadrupole ICP-MS. This method avoids analyte elution from the sorbent. This "dispersed particle extraction" approach yielded a run-to-run relative standard deviation a parts per thousand currency signaEuro parts per thousand 5 % for Pt and a parts per thousand currency signaEuro parts per thousand 4 % for Pd (at 0.1 ng mL(-1), n = 4 road dust digests). Method detection limits (expressed as concentrations in the dust samples) are 2 and 1 ng g(-1) for Pt and Pd, respectively. The method was validated by analysis of a reference material (BCR CRM 723) and applied to the analysis of road dust samples collected in downtown Vienna. Pt and Pd concentrations in samples collected in summer and in winter were compared, with concentrations ranging from 205 to 1445 ng g(-1) for Pt and from 201 to 1230 ng g(-1) for Pd

A Study of Correctional Officers and Inmates Perception Relevant to Institutional Custody and Treatment

This paper presents an exploratory study of instructional corrections policy in general and the nature of such within one state system in particular. Traditionally, correctional institutions have evolved along two lines of though - custody and treatment. However, the role of the correctional officer has formulated along only one line of though - custody. Due to the all encompassing nature of the correctional officer position, this imbalance prevents, and may even hamper, treatment potential within the institution

Utilizing Phylogenetic and Geochemical Techniques to Examine Echinoderms Through Time

Understanding biotic changes through Earth’s history has been the goal of paleobiology since the inception of the field. Advances in science and technology have progressed allowing us to reassess old questions and new questions that could have not been addressed without these new methods. Echinoderms (sea stars, sea urchins, etc.) appear in the fossil record during the early Cambrian and are still abundant in marine ecosystems today. This persistence through time has made echinoderms model organisms to answer questions about Earth’s past and present. Despite this role as a model organism there are many questions that remain with respect to evolutionary history and biogeochemistry of echinoderms. The research herein therefore focuses on a combination of phylogenetics and geochemistry. First, I explore the phylogenetics of Paracrinoidea. Paracrinoidea is a clade of Paleozoic echinoderms that exhibit unusual morphologies. These morphologies have hindered our understanding of their phylogenetic relationships and character evolution. This study represents the first rigorous, quantitative phylogenetic analysis of Paracrinoidea. Both a phylogenetic hypothesis and phylomorphospace were generated to inform patterns seen in morphology with an evolutionary perspective. To explore echinoderm geochemistry, I examined major and minor element inclusion in echinoderm skeletal elements from four genera of modern echinoids from the Gulf of Mexico. These echinoids show measurable variation in skeletal composition which indicates a complex relationship between skeletal element growth rate and geochemical composition. These results help inform the utility of fossil echinoderms in geochemical studies and highlights the need for continued study of elemental incorporation in echinoderm skeletal elements. Finally, I explore the geochemistry of fossil echinoderms. Fossilization and diagenetic processes can alter the original chemistry of the fossilized skeletal elements and impact their utility as seawater proxies. This study used both petrographic and geochemical techniques to assess the retention of original chemistry of fossil echinoid skeletal elements. Results highlight the need for caution and petrographic work to determine the retention of original chemistry to assess the utility of echinoderms as proxies. This work highlights the utility of echinoderms as case study organisms and the power of combined analyses to elucidate biotic changes during the Phanerozoic

The Role of Larval Thermal Tolerance in the Distribution of Blue Mussel Species within the Gulf of Maine

Two species of blue mussel, Myrilus edulis and Myrilus trossulus, are sympatric throughout much of the Canadian Maritime Provinces and into the Gulf of Maine. While the distribution of M edulis extends south to the Mid-Atlantic, that of M. trossulus ends abruptly in the Gulf of Maine. I have hypothesized that these differences in adult distribution are the result of species-specific variation in larval thermal tolerances. Previously, it has been shown that when reared at 20 OC, from 36 hour post-fertilization through settlement, M. trossulus had significantly higher mortality rates than M. edulis. This study examined whether species-specific differences in thermal tolerance vary during larval development. Larvae of both species were exposed to three experimental temperatures at three time points during development and growth and mortality were monitored. Larval thermal tolerance for both species changed significantly as a function of age. Instantaneous mortality was highest during the first ten days of development and decreased to the lowest rate during the second ten days of development. Unexpectedly, there were no significant differences in mortality between M. edulis and M. trossulus larvae in any of the age-temperature treatments used in this experiment. These results stand in contrast to those from previous experiments and raise doubt as to whether the steep thermal gradient created by the Eastern Maine Coastal Current limits the distribution of M. trossulus

Oxalic acid in clear and cloudy atmospheres: Analysis of data from International Consortium for Atmospheric Research on Transport and Transformation 2004

Oxalic acid is often the leading contributor to the total dicarboxylic acid mass in ambient organic aerosol particles. During the 2004 International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) field campaign, nine inorganic ions (including SO_4^(2−)) and five organic acid ions (including oxalate) were measured on board the Center for Interdisciplinary Remotely Piloted Aircraft Studies (CIRPAS) Twin Otter research aircraft by a particle-into-liquid sampler (PILS) during flights over Ohio and surrounding areas. Five local atmospheric conditions were studied: (1) cloud-free air, (2) power plant plume in cloud-free air with precipitation from scattered clouds overhead, (3) power plant plume in cloud-free air, (4) power plant plume in cloud, and (5) clouds uninfluenced by local pollution sources. The aircraft sampled from two inlets: a counterflow virtual impactor (CVI) to isolate droplet residuals in clouds and a second inlet for sampling total aerosol. A strong correlation was observed between oxalate and SO_4^(2−) when sampling through both inlets in clouds. Predictions from a chemical cloud parcel model considering the aqueous-phase production of dicarboxylic acids and SO_4^(2−) show good agreement for the relative magnitude of SO_4^(2−) and oxalate growth for two scenarios: power plant plume in clouds and clouds uninfluenced by local pollution sources. The relative contributions of the two aqueous-phase routes responsible for oxalic acid formation were examined; the oxidation of glyoxylic acid was predicted to dominate over the decay of longer-chain dicarboxylic acids. Clear evidence is presented for aqueous-phase oxalic acid production as the primary mechanism for oxalic acid formation in ambient aerosols

Russische und slowakische Phraseme im Vergleich im Themenbereich Haus- und Nutztiere

Die vorliegende Diplomarbeit vergleicht russische und slowakische Phraseme im Themenbereich Haus- und Nutztiere. Der Aufbau der Arbeit gliedert sich in einen theoretischen und einen praktischen Teil. Im theoretischen Abschnitt werden die Merkmale und eine Definition der Phraseologie ausgearbeitet. Außerdem folgt eine kurze Zusammenfassung der Übersetzungstheorie mit dem Schwerpunkt auf den Problemen bei der Übersetzung von Phrasemen. Ein weiteres Kapitel wird der Entstehung von Phraseologismen gewidmet. Im praktischen Teil werden die Phraseme nach folgenden Kategorien verglichen: totale, partielle Äquivalenz und Nulläquivalenz. Am Ende der Arbeit werden die Ergebnisse in tabellarischer und ausformulierter Form zusammengefasst