Uptake of Plutonium on a Novel Thin Film for Use in Spectrometry

Trace elemental and isotopic analysis of actinides via Thermal Ionization Mass Spectrometry (TIMS) is often difficult and time consuming due to intensive sample preparation. Polymer thin films show strong potential for rapid concentration of radionuclides from solution that may prove as suitable substrates for TIMS analyses. In this work, a polymer thin film (~180 nm) was coated onto a silicon substrate and utilized for rapid radioanalytical analysis. The polymer is composed of poly(vinyl benzyl chloride) functionalized with triethyl amine (TEA) to produce an anion-exchange site for concentrating anionic actinide complexes (i.e. PuCl62-, Pu(NO3)62-) from solution. In addition, selectively functionalizing “spots†with TEA creates hydrophilic regions and allows for concentration of an aqueous drop when surrounded by the hydrophobic polymeric backbone. Batch uptake studies were performed using inductively coupled plasma mass spectrometry, liquid scintillation counting and alpha spectrometry to determine uptake kinetics and anion-exchange capacities of the polymer thin film. Results indicated that along with a potential for utilization as a TIMS substrate, the polymer thin film yields high resolution alpha spectra, comparable to samples produced via electrodeposition. An apparent equilibrium constant (Kd) for the functionalized polymer was found to be approximately 9060 L/kg from 9M HCl. The anion exchange capacity of the film was determined using 36Cl uptake studies and found to be 1.25 x 10-1 ± 1.07 × 10-2 meq/gpolymer. Thus, the rapid uptake kinetics, good anion-exchange capacity, and high-resolution alpha spectra show good promise for the use of this thin film for rapid radioanalytical analyses

Addressing the Challenge of Preparing Assistant Principals for the Principalship in Moore County

This problem of practice study attempted to address the challenge of preparing assistant principals for the principalship in Moore County. Across the nation and state, it is a challenge to fill vacant principalships with quality candidates. This problem is magnified in rural school districts. Moore County has had an over 34% principal turnover rate over the last two years. While this turnover on its own was not necessarily negative, it did indicate the strategic need for Moore County to build a pipeline of principal ready candidates. Utilizing a Plan, Do, Study, Act improvement science process, a school leadership academy that involved a small cohort of 9 assistant principals was designed and implemented to address this problem. The design included year-long face-to-face meetings; internal and external professional learning opportunities; standards-based leadership assessments; exposure to leadership experts; and a principal screening interview. The data and observations from this study indicate that this improvement strategy had a positive impact on the problem. Additional recommendations and implications are shared that are applicable to principal preparation programs and school district leadership development initiatives

Personality and getting out the vote

Due in large part to the overlapping layers of federal, state, and local governments, the United States holds more elections than any other industrialized democracy in the world. Perhaps as a result, the U.S. also consistently has the lowest voter turnout of these countries. The importance of mobilizing supporters has long been recognized in conventional political wisdom, but until recently relatively little research had been done into which methods are actually effective at getting out the vote. The extant research tends to focus on the methods used to reach voters (e.g., doorto- door canvassing, direct mail, telephone calls, etc.) and has dealt with the message of the GOTV appeals only as an afterthought. As such, while good information is available regarding the efficacy of different modalities, the research on the effect of the GOTV message is often inconclusive. Likewise, political research has only recently begun to consider the role of individual differences, especially personality, as a predictor of political behavior. Traditionally, individual differences have been treated as “noise” in the context of political research. There are indications, however, that far from being noise, individual differences in general, and personality in particular, are vital considerations and effective predictors of civic engagement (Mondak, Hibbing, Canache, Seligson, & Anderson, 2010), partisanship (Mondak & Halperin, 2008), and political orientation (Verhulst, Hatemi, & Martin, 2010) among potential voters. The results of this study reveal that response to some types of GOTV messages can be modeled using variation in personality traits as a predictor. This is consistent with some earlier findings suggesting systematic variation in political behavior and affiliation associated with variation in personality traits. Furthermore, this study reveals that different types of appeal content do indeed differ significantly in their perceived effectiveness. The study has implications for how GOTV campaigns can be conducted in order to differentially benefit candidates of differing ideologies

Alternative Sample Loading Preparation for Thermal Ionization Mass Spectrometry

This contribution describes a new sample loading method for Thermal Ionization Mass Spectrometry (TIMS), which is used in nuclear safeguards and non-proliferation efforts worldwide and is known as the “gold standard” in isotopic ratio measurements of plutonium. TIMS analysis is used to determine grades of nuclear material and the extent of enrichment at production sites. The current sample loading method for TIMS analysis is known as “bead-loading”. While it provides the lowest detection limit of any known method for plutonium analysis, bead-loading is a difficult, time consuming, and expensive method that results in up to 20% sample loss. The major encumbrance of the method is the need to manually place a small polymer bead (~40 μm diameter) containing the plutonium sample onto a narrow and fragile ionization filament. We have developed an alternative sample loading method that eliminates the difficult and time-consuming steps by pre-coating the ionization filaments with a thin polymer film. Sample loading times have been reduced from hours to minutes. The films remain stably anchored to the filament, thus preventing sample loss. Ongoing TIMS measurements are testing our hypothesis that the method will increase overall measurement efficiency/sensitivity by isolating the sample in close proximity to the filament

Redox‐controlled preservation of organic matter during “OAE 3” within the Western Interior Seaway

During the Cretaceous, widespread black shale deposition occurred during a series of Oceanic Anoxic Events (OAEs). Multiple processes are known to control the deposition of marine black shales, including changes in primary productivity, organic matter preservation, and dilution. OAEs offer an opportunity to evaluate the relative roles of these forcing factors. The youngest of these events—the Coniacian to Santonian OAE 3—resulted in a prolonged organic carbon burial event in shallow and restricted marine environments including the Western Interior Seaway. New high‐resolution isotope, organic, and trace metal records from the latest Turonian to early Santonian Niobrara Formation are used to characterize the amount and composition of organic matter preserved, as well as the geochemical conditions under which it accumulated. Redox sensitive metals (Mo, Mn, and Re) indicate a gradual drawdown of oxygen leading into the abrupt onset of organic carbon‐rich (up to 8%) deposition. High Hydrogen Indices (HI) and organic carbon to total nitrogen ratios (C:N) demonstrate that the elemental composition of preserved marine organic matter is distinct under different redox conditions. Local changes in δ13C indicate that redox‐controlled early diagenesis can also significantly alter δ13Corg records. These results demonstrate that the development of anoxia is of primary importance in triggering the prolonged carbon burial in the Niobrara Formation. Sea level reconstructions, δ18O results, and Mo/total organic carbon ratios suggest that stratification and enhanced bottom water restriction caused the drawdown of bottom water oxygen. Increased nutrients from benthic regeneration and/or continental runoff may have sustained primary productivity.Key PointsBottom water redox changes triggered carbon burial within the WIS during OAE 3Anoxia developed due to O2 drawdown in a stratified water columnRedox‐controlled changes in OM preservation altered primary δ13Corg signalsPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/112294/1/palo20210.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/112294/2/palo20210-sup-0001-SupportingInfo.pd

Carbon cycle history through the Jurassic–Cretaceous boundary: A new global δ13C stack

publisher: Elsevier articletitle: Carbon cycle history through the Jurassic–Cretaceous boundary: A new global δ13C stack journaltitle: Palaeogeography, Palaeoclimatology, Palaeoecology articlelink: http://dx.doi.org/10.1016/j.palaeo.2016.03.016 content_type: article copyright: Copyright © 2016 Published by Elsevier B.V