Differences in Second Language Acquisition and Academic Achievement by Extracurricular Activity Participation for English Language Learners

In this study differences in academic performance on the Texas English Language Proficiency Assessment System and State of Texas Assessments of Academic Readiness as a function of participation in extracurricular activities for English Language Learners were examined Data obtained from a large suburban district in southeast Texas for all students who were enrolled in Grades 6 through 12 for the 2014-2015 school year were analyzed Patterned after the federal Annual Measurable Achievement Objectives for English Language Learners participation in extracurricular activities for English Language Learners was not related to second language acquisition or the attainment of English fluency Conversely in regard to performance on state assessments in reading and in mathematics English Language Learners who were not involved in extracurricular activities had higher scores than English Language Learners who were involved in extracurricular activities Suggestions for research and policy were provide

Physical weathering intensity controls bioavailable primary iron(II) silicate content in major global dust sources

The speciation of iron (Fe) reaching the ocean, for instance in wind‐blown dust and coastal sediments, impacts its bioavailability to phytoplankton and its impact on atmospheric carbon dioxide (CO2) and climate. For dust reaching the Southern Ocean, primary Fe(II) silicates that are physically weathered from bedrock are highly bioavailable compared to more chemically weathered, Fe(III)‐rich species, suggesting that weathering in dust source regions impacts the bioavailable Fe supply. However, this phenomenon has not been studied in other important terrestrial Fe sources, where weathering regimes and source geology vary. Here, we use Fe X‐ray absorption spectroscopy on marine sediment cores to show that major global dust and sediment sources impacted by high physical weathering contain abundant primary minerals and thus are overlooked as a source of highly bioavailable Fe globally. Thus, it is important to consider the role of physical versus chemical weathering in Fe fertilization and biotic CO2 cycling

Production and Composition of Pyrogenic Dissolved Organic Matter From a Logical Series of Laboratory-Generated Chars

Though pyrogenic carbon (pyC) has been assumed to be predominantly stable, degradation and transfers of pyC between various pools have been found to influence its cycling and longevity in the environment. Dissolution via leaching may be the main control on loss processes such as microbial or abiotic oxidation, mineral sorption, or export to aquatic systems. Yet, little is known about the controls on pyrogenic dissolved organic matter (pyDOM) generation or composition. Here, the yield and composition of pyDOM generated through batch leaching of a thermal series of oak and grass biochars, as well as several non-pyrogenic reference materials, was compared to that of their parent solids. Over 17 daily leaching cycles, biochars made from oak at 250–650◦C released decreasing amounts of C on both a weight (16.9–0.3%, respectively) and C yield basis (7.4–0.2% C, respectively). Aryl-C represented an estimated 32–82% of C in the parent solids (identified by 13C-NMR), but only 7–38% in the leachates (identified by 1H-NMR), though both increased with pyrolysis temperature. PyC, often operationally defined as condensed aromatic carbon (ConAC), was quantified using the benzenepolycarboxylic acid (BPCA) method. Tri- and tetra-carboxylated BPCAs were formed from non-pyrogenic reference materials, thus, only penta- and hexa-carboxylated BPCAs were used to derive a BPCA-C to ConAC conversion factor of 7.04. ConAC made up 24–57% of the pyrogenic solid C (excluding the 250◦C biochar), but only about 9–23% of their respective leachates’ DOC, though both proportions generally increased with pyrolysis temperature. Weighted BPCA compound distributions, or the BPCA Aromatic Condensation (BACon) Index, indicate that ConAC cluster size increased in pyrogenic solids but not in leachates. Additional evidence presented suggests that both aromatic cluster size and O-containing functional group contents in the pyrogenic solid control pyC solubility. Overall, pyDOM was found to be compositionally dissimilar from its parent chars and contained a complex mixture of organic compound groups. Thus, it is expected that estimates of dissolved pyC production and export, made only by detection of ConAC, are too low by factors of 4–11

Microbial Labilization and Diversification of Pyrogenic Dissolved Organic Matter

With the increased occurrence of wildfires around the world, interest in the chemistry of pyrogenic organic matter (pyOM) and its fate in the environment has increased. Upon leaching from soils by rain events, significant amounts of dissolved pyOM (pyDOM) enter the aquatic environment and interact with microbial communities that are essential for cycling organic matter within the different biogeochemical cycles. To evaluate the biodegradability of pyDOM, aqueous extracts of laboratory-produced biochars were incubated with soil microbes, and the molecular changes to the composition of pyDOM were probed using ultrahigh-resolution mass spectrometry (Fourier transform–ion cyclotron resonance–mass spectrometry). Given that solar irradiation significantly affects the composition of pyDOM during terrestrial-to-marine export, the effects of photochemistry were also evaluated in the context of pyDOM biodegradability. Ultrahigh-resolution mass spectrometry revealed that many different (both aromatic and aliphatic) compounds were biodegraded. New labile compounds were produced, 22 %–40 % of which were peptide-like. These results indicated that a portion of pyDOM has been labilized into microbial biomass during the incubations. Fluorescence excitation–emission matrix spectra revealed that some fraction of these new bio-produced molecules is associated with proteinaceous fluorophores. Two-dimensional 1H–1H total correlation nuclear magnetic resonance (NMR) spectroscopy identified a peptidoglycan-like backbone within the microbially produced compounds. These results are consistent with previous observations of peptidoglycans within the soil and ocean nitrogen cycles where remnants of biodegraded pyDOM are expected to be observed. Interestingly, the exact nature of the bio-produced organic matter was found to vary drastically among samples indicating that the microbial consortium used may produce different exudates based on the composition of the initial pyDOM. Another potential explanation for the vast diversity of molecules is that microbes only consume low molecular-weight compounds, but they also produce reactive oxygen species (ROS), which initiate oxidative and recombination reactions that degrade high molecular-weight compounds and produce new molecules. Some of the bio-produced molecules (212–308 molecular formulas) were identified in estuarine and marine (surface and abyssal oceanic), and 81–192 of these formulas were of molecular composition attributed to carboxyl-rich alicyclic molecules (CRAM). These results indicate that some of the pyDOM biodegradation products have an oceanic fate and can be sequestered into the deep ocean. The observed microbially mediated diversification of pyDOM suggests that pyDOM contributes to the observed large complexity of natural organic matter observed in riverine and oceanic systems. More broadly, our research shows that pyDOM can be substrate for microbial growth and be incorporated into environmental food webs within the global carbon and nitrogen cycles

Biolability of Fresh and Photodegraded Pyrogenic Dissolved Organic Matter From Laboratory-Prepared Chars

Pyrogenic dissolved organic matter (pyDOM) is known to be an important biogeochemical constituent of aquatic ecosystems and the carbon cycle. While recent studies have examined how pyDOM production, composition, and photolability varies with parent pyrogenic solid material type, we lack an understanding of potential microbial mineralization and transformation of pyDOM in the biogeosphere. Thus, leachates of oak, charred at 400 °C and 650 °C, as well as their photodegraded counterparts were incubated with a soil‐extracted microbial consortium over 96 days. During the incubation, significantly more carbon was biomineralized from the lower versus higher temperature char leachate (45% vs. 37% lost, respectively). Further, the photodegraded leachates were biomineralized to significantly greater extents than their fresh non‐photodegraded counterparts. Kinetic modeling identified the mineralizable pyDOC fractions to have half‐lives of 9–13 days. Proton nuclear magnetic resonance spectroscopy indicated that the majority of this loss could be attributed to low molecular weight constituents of pyDOM (i.e., simple alcohols and acids). Further, the quantification of benzenepolycarboxylic acid (BPCA) molecular markers indicated that condensed aromatic compounds in pyDOM were biomineralized to much lesser extents (4.4% and 10.1% decrease in yields of ΣBPCA‐C over 66 days from 400 °C and 650 °C oak pyDOM, respectively), but most of this loss could be attributed to the biomineralization of smaller condensed clusters (four aromatic rings or less). These results highlight the contrasting bioavailability of different portions of pyDOM, and the need to examine both to evaluate its role in soil or aquatic heterotrophy and its environmental fate in the hydrogeosphere

Biolability of Fresh and Photodegraded Pyrogenic Dissolved Organic Matter From Laboratory-Prepared Chars

Pyrogenic dissolved organic matter (pyDOM) is known to be an important biogeochemical constituent of aquatic ecosystems and the carbon cycle. While recent studies have examined how pyDOM production, composition, and photolability varies with parent pyrogenic solid material type, we lack an understanding of potential microbial mineralization and transformation of pyDOM in the biogeosphere. Thus, leachates of oak, charred at 400 °C and 650 °C, as well as their photodegraded counterparts were incubated with a soil‐extracted microbial consortium over 96 days. During the incubation, significantly more carbon was biomineralized from the lower versus higher temperature char leachate (45% vs. 37% lost, respectively). Further, the photodegraded leachates were biomineralized to significantly greater extents than their fresh non‐photodegraded counterparts. Kinetic modeling identified the mineralizable pyDOC fractions to have half‐lives of 9–13 days. Proton nuclear magnetic resonance spectroscopy indicated that the majority of this loss could be attributed to low molecular weight constituents of pyDOM (i.e., simple alcohols and acids). Further, the quantification of benzenepolycarboxylic acid (BPCA) molecular markers indicated that condensed aromatic compounds in pyDOM were biomineralized to much lesser extents (4.4% and 10.1% decrease in yields of ΣBPCA‐C over 66 days from 400 °C and 650 °C oak pyDOM, respectively), but most of this loss could be attributed to the biomineralization of smaller condensed clusters (four aromatic rings or less). These results highlight the contrasting bioavailability of different portions of pyDOM, and the need to examine both to evaluate its role in soil or aquatic heterotrophy and its environmental fate in the hydrogeosphere

Wax Point Determinations Using Acoustic Resonance Spectroscopy

The thermodynamic characterization of the wax point of a given crude is essential in order to maintain flow conditions that prevent plugging of undersea pipelines. This report summarizes the efforts made towards applying an Acoustic Cavity Resonance Spectrometer (ACRS) to the determination of pressures and temperatures at which wax precipitates from crude. Phillips Petroleum Company, Inc., the CRADA participant, supplied the ACRS. The instrumentation was shipped to Dr. Thomas Schmidt of ORNL, the CRADA contractor, in May 2000 after preliminary software development performed under the guidance of Dr. Samuel Colgate and Dr. Evan House of the University of Florida, Gainesville, Fl. Upon receipt it became apparent that a number of modifications still needed to be made before the ACRS could be precisely and safely used for wax point measurements. This report reviews the sequence of alterations made to the ACRS, as well as defines the possible applications of the instrumentation once the modifications have been completed. The purpose of this Cooperative Research and Development Agreement (CRADA) between Phillips Petroleum Company, Inc. (Participant) and Lockheed Martin Energy Research Corporation (Contractor) was the measurement of the formation of solids in crude oils and petroleum products that are commonly transported through pipelines. This information is essential in the proper design, operation and maintenance of the petroleum pipeline system in the United States. Recently, new petroleum discoveries in the Gulf of Mexico have shown that there is a potential for plugging of undersea pipeline because of the precipitation of wax. It is important that the wax points of the expected crude oils be well characterized so that the production facilities for these new wells are capable of properly transporting the expected production. The goal of this work is to perform measurements of solids formation in crude oils and petroleum products supplied by the Participant. It is anticipated that these data will be used in the design of new production facilities and in the development of thermodynamic models that describe the behavior of wax-saturated petroleum

Linear-Accelerator Program

Contains reports on one research project

Design of Microwave Vitrification Systems for Radioactive Waste

Oak Ridge National Laboratory (ORNL) is involved in the research and development of high-power microwave heating systems for the vitrification of DOE radioactive sludges. Design criteria for a continuous microwave vitrification system capable of processing a surrogate filtercake sludge representative of a typical waste-water treatment operation are discussed. A prototype 915 MHz, 75 kW microwave vitrification system or `microwave melter` is described along with some early experimental results that demonstrate a 4 to 1 volume reduction of a surrogate ORNL filtercake sludge