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Sample records for alder creek sanidine

  1. 40Ar/39Ar ages from the rhyolite of Alder Creek, California: age of the Cobb Mountain normal-polarity subchron revisited

    USGS Publications Warehouse

    Turrin, B.D.; Donnelly-Nolan, J. M.; Hearn, B.C., Jr.

    1994-01-01

    New 40Ar/39Ar age determinations on sanidine from the rhyolite of Alder Creek, California, indicate a 1.186 ?? 0.006 Ma age for the Cobb Mountain Normal-Polarity Subchron. The hew age is statistically older (?? = 0.05) than the previously reported K-Ar age (1.12 ?? 0.02 Ma) and agrees with the age suggested by the astronomical polarity time scale. Incomplete extraction of radiogenic 40Ar (40Ar*) from the sanidine is the most likely reason for the disparity between the 40Ar/39Ar and K-Ar ages. Because the Cobb Mountain subchron is a worldwide, short-duration event, and because no widely used interlaboratory 40Ar/39Ar standard younger than 27 Ma exists, it is proposed that sanidine from the rhyolite of Alder Creek be considered for use as a new Quaternary 40Ar/39Ar mineral standard. -Authors

  2. 54. ALDER CREEK DIVERSION, PROJECT 1933, EXHIBIT F, SANTA ANA ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    54. ALDER CREEK DIVERSION, PROJECT 1933, EXHIBIT F, SANTA ANA POWERHOUSE NO. 2 SCE drawing no. 5206858, no date (FERC no. 1933-48). - Santa Ana River Hydroelectric System, Redlands, San Bernardino County, CA

  3. Effects of Alder Mine on the Water, Sediments, and Benthic Macroinvertebrates of Alder Creek, 1998 Annual Report.

    SciTech Connect

    Peplow, Dan

    1999-05-28

    The Alder Mine, an abandoned gold, silver, copper, and zinc mine in Okanogan County, Washington, produces heavy metal-laden effluent that affects the quality of water in a tributary of the Methow River. The annual mass loading of heavy metals from two audits at the Alder Mine was estimated to exceed 11,000 kg per year. In this study, water samples from stations along Alder Creek were assayed for heavy metals by ICP-AES and were found to exceed Washington State's acute freshwater criteria for cadmium (Cd), copper (Cu), selenium (Se), and zinc (Zn).

  4. Age of the Lava Creek supereruption and magma chamber assembly at Yellowstone based on 40Ar/39Ar and U-Pb dating of sanidine and zircon crystals

    NASA Astrophysics Data System (ADS)

    Matthews, Naomi E.; Vazquez, Jorge A.; Calvert, Andrew T.

    2015-09-01

    The last supereruption from the Yellowstone Plateau formed Yellowstone caldera and ejected the >1000 km3 of rhyolite that composes the Lava Creek Tuff. Tephra from the Lava Creek eruption is a key Quaternary chronostratigraphic marker, in particular for dating the deposition of mid Pleistocene glacial and pluvial deposits in western North America. To resolve the timing of eruption and crystallization history for the Lava Creek magma, we performed (1) 40Ar/39Ar dating of single sanidine crystals to delimit eruption age and (2) ion microprobe U-Pb and trace-element analyses of the crystal faces and interiors of single zircons to date the interval of zircon crystallization and characterize magmatic evolution. Sanidines from the two informal members composing Lava Creek Tuff yield a preferred 40Ar/39Ar isochron date of 631.3 ± 4.3 ka. Crystal faces on zircons from both members yield a weighted mean 206Pb/238U date of 626.5 ± 5.8 ka, and have trace element concentrations that vary with the eruptive stratigraphy. Zircon interiors yield a mean 206Pb/238U date of 659.8 ± 5.5 ka, and reveal reverse and/or oscillatory zoning of trace element concentrations, with many crystals containing high U concentration cores that likely grew from highly evolved melt. The occurrence of distal Lava Creek tephra in stratigraphic sequences marking the Marine Isotope Stage 16-15 transition supports the apparent eruption age of ˜631 ka. The combined results reveal that Lava Creek zircons record episodic heating, renewed crystallization, and an overall up-temperature evolution for Yellowstone's subvolcanic reservoir in the 103-104 year interval before eruption.

  5. Age of the Lava Creek supereruption and magma chamber assembly at Yellowstone based on 40Ar/39Ar and U-Pb dating of sanidine and zircon crystals

    USGS Publications Warehouse

    Matthews, Naomi E.; Vazquez, Jorge A.; Calvert, Andrew T.

    2015-01-01

    The last supereruption from the Yellowstone Plateau formed Yellowstone caldera and ejected the >1000 km3 of rhyolite that composes the Lava Creek Tuff. Tephra from the Lava Creek eruption is a key Quaternary chronostratigraphic marker, in particular for dating the deposition of mid Pleistocene glacial and pluvial deposits in western North America. To resolve the timing of eruption and crystallization history for the Lava Creek magma, we performed (1) 40Ar/39Ar dating of single sanidine crystals to delimit eruption age and (2) ion microprobe U-Pb and trace-element analyses of the crystal faces and interiors of single zircons to date the interval of zircon crystallization and characterize magmatic evolution. Sanidines from the two informal members composing Lava Creek Tuff yield a preferred 40Ar/39Ar isochron date of 631.3 ± 4.3 ka. Crystal faces on zircons from both members yield a weighted mean 206Pb/238U date of 626.5 ± 5.8 ka, and have trace element concentrations that vary with the eruptive stratigraphy. Zircon interiors yield a mean 206Pb/238U date of 659.8 ± 5.5 ka, and reveal reverse and/or oscillatory zoning of trace element concentrations, with many crystals containing high U concentration cores that likely grew from highly evolved melt. The occurrence of distal Lava Creek tephra in stratigraphic sequences marking the Marine Isotope Stage 16–15 transition supports the apparent eruption age of ∼631 ka. The combined results reveal that Lava Creek zircons record episodic heating, renewed crystallization, and an overall up-temperature evolution for Yellowstone's subvolcanic reservoir in the 103−104 year interval before eruption.

  6. Age of the Lava Creek supereruption and magma chamber assembly at Yellowstone based on 40Ar/39Ar and U-Pb dating of sanidine and zircon crystals

    NASA Astrophysics Data System (ADS)

    Vazquez, J. A.; Matthews, N. E.; Calvert, A. T.

    2015-12-01

    The last supereruption from the Yellowstone Plateau formed Yellowstone caldera and ejected the >1000 km3 of rhyolite that composes the Lava Creek Tuff (LCT). Tephra from the eruption blanketed much of the western United States, and is a key Quaternary chronostratigraphic marker, in particular for dating deposition of mid-Pleistocene glacial and pluvial deposits in western North America. We performed 40Ar/39Ar dating of single sanidines to delimit eruption age, and ion microprobe U-Pb and trace-element analyses of crystal faces on single zircons to characterize magmatic evolution and date near-eruption crystallization, as well as analyses of crystal interiors to date the interval of zircon crystallization. Sanidines from the two LCT members A and B yield an 40Ar/39Ar isochron date of 631 ± 4 ka (2σ). Crystal faces on zircons from both members yield a weighted mean 206Pb/238U date of 627 ± 6 ka (2σ) and have trace element concentrations that vary with eruptive stratigraphy. Zircon interiors yield a weighted mean 206Pb/238U date of 660 ± 6 ka, and reveal reverse and/or oscillatory zoning of trace element concentrations, with many crystals containing high-U concentrations and dark cathodoluminescence (CL) cores. These crystals with high-U cores are possibly sourced from 'defrosting' of melt-impregnated margins of the growing subvolcanic reservoir. LCT sanidines mirror the variation of zircon composition within the eruptive stratigraphy, with crystals from upper LCT-A and basal LCT-B having bright-CL rims with high Ba concentrations, suggesting late crystallization after addition of less evolved silicic magma. The occurrence of distal LCT in stratigraphic sequences marking the Marine Isotope Stage 16-15 transition supports the apparent eruption age of ca. 631 ka. These results reveal that Lava Creek zircons record episodic heating, renewed crystallization, and an overall up-temperature evolution for Yellowstone's subvolcanic reservoir in the 103-104 year interval

  7. Pressure Dependent Mass Fraction in Noble Gas Mass Spectrometers: A Possible Explanation for the Excessive Dispersion in the EARTHTIME Fish Canyon/Alder Creek Inter-Calibration Experiment

    NASA Astrophysics Data System (ADS)

    Turrin, B. D.; Swisher, C. C.; Mana, S.

    2011-12-01

    Mass spectrometer fractionation bias (mass discrimination) is a ubiquitous phenomenon in noble gas mass spectroscopy and must be corrected for in order to obtain accurate-high precision isotopic ratios that are used in isotopic age calculations. Temporal variations in mass fractionation are well known phenomena and have been reported in several studies (eg. Turrin et al., 2010 and references therein). Here we report on the pressure dependency on mass spectrometer fractionation bias. In our experiment, we varied by a factor of five the signal size of aliquots of atmospheric argon delivered from an automated air pipette system. The measured mass discrimination difference (MD) as determined by the 40Ar/36Ar ratio between the 1-fold and 5-fold air pipette shots is ~5%. The air 40Ar/36Ar aliquots were measured using a MAP 215-50 operating in pulse counting mode. The air measurements were interspersed with measurements of Alder Creek (AC) sanidine and Fish Canyon (FC) sanidine that were co-irradiated for 0.75 hours. The grain sizes for the two mineral standards were chosen such that the AC sample yielded 40Ar signals of about 50 kcps, similar to that delivered by a single aliquot delivered by the air pipette. The FC grains were about 5-10 times greater (150-600 kcps) than the single air aliquot. Following the analyses, we applied the MD correction to both the FC and AC analyses. When the MD as determined from the single pipette data (which matches 40Ar beam intensity of the AC sample) is applied to both the AC and FC data a "J" of 1.579±0.001x10-4 is obtained from the FC data and an age of 1183 ±4 ka for AC. However, when the MD as determined from the multiple aliquot pipette data (with an 40Ar beam similar to that of the FC analyses) is applied to the FC data a "J" of 1.588±0.001x10-4 is obtained and an AC age of 1189 ±4 ka the same age at the 95% confidence level, the reported age for AC. We conclude that variation in MD over signal sizes typically analyzed in 40Ar

  8. Concordant ages for the Lava Creek Tuff from high-spatial-resolution U-Pb dating of zircon rim faces and single-crystal sanidine 40Ar/39Ar dating

    NASA Astrophysics Data System (ADS)

    Matthews, N. E.; Vazquez, J. A.; Calvert, A. T.

    2013-12-01

    The last great explosive supereruption from the Yellowstone Plateau formed present-day Yellowstone caldera and ejected the >1000 km3 of rhyolite that composes the Lava Creek Tuff (LCT). The LCT eruption blanketed much of the western United States in ash, and consequently is a key chronostratigraphic marker bed for delimiting Quaternary uplift rates, the age of middle Pleistocene glacial and pluvial deposits, and tephra correlation in North America. Previous 40Ar/39Ar dating of the two mineralogically distinct LCT members (A & B) yield ages ranging from ca. 600 ka (Gansecki et al., 1998) to ca. 640 ka (Lanphere et al., 2002). To resolve the timing of eruption and crystallization timescale for the LCT magma, we dated both LCT members using a dual-method approach as follows: (1) ion microprobe (SHRIMP-RG) U-Pb dating and trace-element characterization of the final few micrometers of zircon crystallization by analysis of unpolished rims on indium-mounted crystals, and dating of the onset of zircon crystallization by traditional analysis of sectioned crystal interiors, and (2) laser-fusion 40Ar/39Ar dating of single sanidine crystals from bulk LCT ignimbrite and pumice. The unpolished rims of zircon from LCT members A & B yield indistinguishable ages, with a mean age of 621.8 × 2.5 ka (1σ) after correction for initial 230Th disequilibrium as constrained by ion-probe analyses of LCT melt inclusions. Single sanidine crystals from LCT-B yield a mean age of 624.9 × 2.6 ka (FCT=28.17 Ma) that is indistinguishable from the zircon rim ages for both members. These results indicate that LCT members A & B erupted over a geologically brief interval, which is supported by the direct and gradational contact of their equivalent fallout in distal lacustrine deposits and a lack of field evidence for a significant time-break between the LCT A & B in proximal deposits (Christiansen, 2001), but contrasts with older Yellowstone ignimbrite (e.g., Huckleberry Ridge) that may have erupted

  9. Origin of a sanidine-coesite grospydite

    SciTech Connect

    Wohletz, K.H.; Smyth, J.R.

    1982-01-01

    A grospydite xenolith from the Roberts Victor kimberlite pipe in South Africa presents an unusual phase assemblage of clinopyroxene, garnet, kyanite, coesite, and sanidine. The rock as previously described (Smyth and Hatton, 1977) consists of 50% omphocitic clinopyroxene, 28% garnet (Gr/sub 50/Py/sub 28/Alm/sub 22/), 9% kyanite, 65 coesite, and 1% sanidine (Or/sub 99/). Assuming the addition of three additional compatible phases (phlogopite, enstatite, and H/sub 2/O vapor) and a simplified chemistry of the phases present, a Schreinemakers thermodynamic analysis was attempted in order to estimate the pressure and temperature of equilibrium of the rock. Four reactions involving six components are likely to have determined an invariant point for the assemblage: (1) Kyn + 2 Cpx reversible Cos + Gt + En; (2) 3 Cos + Phl reversible San + 3 En + H/sub 2/O; (3) 3 Kyn + 6 Cpx + Phl reversible San + 3 Gt + 6 En + H/sub 2/O; and (4) 6 Cos + 3 gt + Phl reversible San + 3 Kyn + 6 Cpx + H/sub 2/O. Using tabulated as well as estimated thermodynamic data for the phases, the calculated values for equilibrium temperatures and pressures for the reactions yield an invariant point for the assemblage at a depth of about 160 km (40 kbars) and a temperature of about 1060/sup 0/C. This point likely represents a subsolidus recrystallization stage of origin.

  10. Distribution of rubidium between sodic sanidine and natural silicic liquid

    USGS Publications Warehouse

    Noble, D.C.; Hedge, C.E.

    1970-01-01

    Phenocrysts of sodic sanidine from twelve upper Cenozoic units of silicic ash-flow tuff and lava from the Western United States contain from 0.25 to 0.45 the Rb present in the associated groundmass materials. The ratios of potassium to rubidium in the sanidines are, on the average, about four times greater than those of the groundmass. Separation of phenocrystic sanidine from salic melts provides an efficient method for raising the Rb content and lowering the K/Rb ratio of the melts, although the amount of differentiation probably is limited by continuous reequilibration of the alkalis between crystal and liquid phases through ion exchange. Syenites of cumulate origin will have appreciably lower Rb contents and higher K/Rb ratios than the melts from which they precipitated. Available data on the distribution of Rb between synthetic biotite and K-sanidine demonstrate that the separation of biotite probably will not deplete salic melts in Rb relative to K. ?? 1970 Springer-Verlag.

  11. Heat transfer in quartz, orthoclase, and sanidine at elevated temperature

    NASA Astrophysics Data System (ADS)

    Höfer, M.; Schilling, F.

    The thermal diffusivity of quartz, orthoclase, and sanidine was measured in different directions by a transient method, to determine the second-rank tensor of thermal transport properties as a function of temperature up to 800 °C. Thermal diffusivity of phonons is described as D=1/3 v l, where v is the phonon velocity and l the mean free path length of phonons. In quartz the thermal diffusivity at room temperature is 3.60 mm2 s-1 in [1 0 0] and 7.00 mm2 s-1 in [0 0 1] direction. A 1/T dependency of thermal diffusivity is observed for both directions up to 550 °C with a pronounced anisotropy (A=62% A=(Dmax - Dmin)/Daverage), which decreases with increasing temperature. Close to the α-β-phase transition, we observed a minimum in thermal diffusivity and a negligible anisotropy. Up to 573 °C the maximam of thermal diffusivity, average phonon velocity, and mean free path length are observed in [0 0 1] direction. However, above the temperature of phase transition the maximum values of the properties are observed in [1 0 0] direction. The observed behavior is explained by a model which interrelates velocity and mean free path length of phonons. A further contribution to the thermal diffusivity behavior is related to the higher symmetry of β-quartz, resulting in a reduced phonon-phonon-scattering probability. At ambient temperature, orthoclase and sanidine show similar values of thermal diffusivities ( 1 mm2 s-1) and a temperature-independent anisotropy behavior between 22 and 350 °C of 30%. For both feldspars a small 1/T temperature dependence of thermal diffusivity up to 350 °C is observed. The transparent sanidine in gemstone quality shows a strong increase in thermal diffusivity above 350 °C proportional to T 3. The contribution of the radiative heat-transfer mechanism leads to values more than two times higher in sanidine than in a milky-cloudy orthoclase at 800 °C. For the feldspars the mean free path length of phonons shows a small temperature dependence

  12. The Dynamics of the Post-Caldera Magmatic System at Yellowstone: Insights from Age, Trace Element, and Isotopic Data of Zircon and Sanidine

    NASA Astrophysics Data System (ADS)

    Stelten, M. E.; Cooper, K. M.; Vazquez, J. A.; Calvert, A. T.; Glessner, J. J.; Wimpenny, J.; Yin, Q. Z.

    2014-12-01

    Yellowstone hosts a voluminous magmatic system that produced three silicic caldera-forming eruptions over the past 2.1 My. Following the most recent of these (the Lava Creek Tuff at 639 ka), the magma system at Yellowstone underwent two episodes of intracaldera eruptions, the latest of which produced the Central Plateau Member (CPM) rhyolites. The CPM rhyolites erupted intermittently from ca. 170 ka to ca. 70 ka and can be viewed as snapshots of the magma system through time, which provides a unique opportunity to study the dynamics of an evolving caldera system. To constrain the nature and timescales of magmatic processes at Yellowstone we examine four CPM rhyolites that erupted from ca. 116 ka to ca. 74 ka and present a comprehensive data set that integrates (1) 238U-230Th ages, trace-elements, and Hf isotope compositions of the surfaces and interiors of single zircons, (2) bulk 238U-230Th ages and in situ Ba and Pb isotope compositions of sanidines, (3) sanidine 40Ar-39Ar ages, and (4) trace-element and isotopic compositions of the CPM glasses. Zircon 238U-230Th ages and Hf isotope data demonstrate that isotopically juvenile magmas, derived from Yellowstone basalts, were added to the Yellowstone magma reservoir over time and were fundamental to its post-caldera isotopic evolution. We use zircon Hf isotope data along with new Hf isotope data (and existing O isotope data) for the Yellowstone basalts (whole-rocks), older Yellowstone rhyolites (glasses), and local crustal sources to quantify the role of isotopically juvenile magma in the evolution of the magmatic system. Additionally, linking age, trace-element, and isotopic data from zircon and sanidine demonstrates that eruptible CPM rhyolites were generated by extracting melt and antecrystic zircon from a long-lived (>200 ky) crystal mush, while sanidine remained trapped in the crystal network. The extracted melts amalgamated and then crystallized new sanidines and rims on the antecrystic zircons that were in

  13. Volcanic processes recorded by inclusions in sanidine megacrystals ejected from Quaternary Rockeskyll volcano, Eifel, Germany

    NASA Astrophysics Data System (ADS)

    Eilhard, Nicole; Schreuer, Jürgen; Stöckhert, Bernhard

    2016-04-01

    Sanidine megacrystals were ejected by a late stage explosive eruption at the Quaternary Rockeskyll volcanic complex, Eifel volcanic field, Germany. The homogeneous distribution of barium (about 1 % wt BaO equivalent to about 2 mole % celsian component) indicates that the nearly perfect single crystals must have crystallized in the Ostwald-Miers range from a huge reservoir, probably in the roof of a magma chamber. Irregularities during crystal growth caused trapping of hydrous melt inclusions, which are the objective of the present study. The inclusions show a characteristic concentric microstructure, in the following described from the sanidine host towards the inclusion center: (1) Ba is enriched by a factor of 2 to 3 in a ca. 0.01 mm wide rim, compared to the otherwise homogeneous sanidine host; (2) inwards, the continuous rim is overgrown by a thin crust of Ba enriched sanidine with irregular surface; (3) a layer of glass with a composition similar to sanidine; (4) a second, thinner layer of glass slightly reduced in Na2O and K2O, separated from the first glass layer by a sharp interface with approximately spherical shape; (5) a bubble containing a fluid phase, composed of H2O and minor CO2. This record is interpreted as follows: After crystallization of the sanidine megacrystals, a rise in temperature within the magmatic system caused some re-melting of the Ba-rich sanidine around the inclusions. Partitioning of Ba between the small included melt reservoir and the host caused formation of the Ba-rich rim (layer 1) by diffusive exchange. The onset of cooling lead to crystallization of the thin sanidine crust (layer 2). Finally, very rapid decompression and cooling during the subsequent explosive eruption caused sequential phase separation (two stages) in the remaining melt, the denser melt phase (layers 3 and 4) quenched to glass, the complementary low-density volatile-rich phase forming the central bubble. In summary, the microstructure and phase composition of

  14. Anomalous elastic behaviour of hydrous sanidine megacrysts from the Eifel, Germany

    NASA Astrophysics Data System (ADS)

    Schreuer, Jürgen; Demtröder, Kathrin; Sondergeld, Peter; Dehn, Sara

    2010-05-01

    Sanidine megacrystals from Volkesfeld (Riedener Kessel, East Eifel volcanic field) are well known for their fast irreversible changes of optical properties at moderately high annealing temperatures (starting from 750°C) [1]. These unique optical effects are probably related to fast changes of the Al/Si-order, the origin of which is not yet understood. Polarised infrared spectra and NMR studies indicate a relatively high amount of water (about 200 wt-ppm) in the Eifel sanidines compared to low-sanidine crystals from Madagascar (~ 1 wt-ppm) [2,3] possessing no unusual optical properties at high temperatures. In order to clarify the role of water for the observed anomalies, we investigated the elastic properties of sanidine megacrystals from four different eruptive centres (Essingen, Kerpen, Rockeskyll, Volkesfeld) of the quarternary volcanic fields of the Eifel between room temperature and 1100°C with the aid of resonant ultrasound spectroscopy (RUS). Low-sanidine from Madagascar served as a reference. The Eifel sanidine megacrystals are all very similar in respect to their chemical and structural properties. The chemical composition NaxK1-xAlSi3O8 as obtained by EMPA varies between x = 0.15 (east Eifel volcanic field) and 0.27 (west Eifel volcanic field) with up to 2 at-% celsian and less than 0.02 at-% anorthite. High-resolution DSC and thermogravimetric measurements revealed an irreversible weight loss at about 950°C which corresponds to about 250 wt-ppm H2O. Single crystal structure analyses yielded 2t1 ≈ 0.58 for the Al-occupation of the t1 tetrahedral position indicating nearly fully disordered high-sanidines. For comparison, the potassium-rich low-sanidines from Madagascar are characterised by 2t1 = 0.69. The temperature evolution of the elastic constants of 'dry' Madagascar sanidine is monotonic and fully reversible in successive runs. However, at about 890°C a small peak appears in the ultrasound attenuation above a slowly rising background. In

  15. The effect of alder forest cover and alder forest conversion on site fertility and productivity

    SciTech Connect

    Van Miegroet, H.; Cole, D.W.; Homann, P.S.

    1988-01-01

    Red alder (Alnus rubra Bong.) is known for its ability to improve the status of soil N through symbiotic N fixation. The objective of this paper is to assess the effect of red alder forests and their removal on soil and solution chemistry and on the growth of trees subsequently established on such sites. This was achieved through a series of paired field comparisons at two locations in Washington, involving similar-aged pure alder and Douglas-fir forests on soils that were essentially the same prior to stand establishment. At Pack Forest alder and Douglas-fir stands on high- and low-productivity sites were subjected to three levels of harvesting: bore only removal, whole tree (aboveground) harvesting, and complete removal of all vegetation and forest floor. The effect of harvesting intensity was examined on nutrient removal with biomass and through leaching, and on subsequent seedling growth. At Thompson Research Center adjacent Douglas-fir and alder forests were harvested, and half of each area was replanted with either Douglas-fir or red alder seedlings, yielding four forest conversion units. Differences in growth patterns, tree nutrient status, and leaching losses between these conversion plots were examined. Compared with adjacent Douglas-fir forests, substantially more N, P, K, and Ca are tied up in aboveground vegetation and on the forest floor of alder forests, and these elements also cycle faster in alder ecosystems primarily due to the deciduous nature of alder.

  16. Ba-rich sanidine megacrysts in trachytic rocks of Eslamy volcano, NW Iran

    NASA Astrophysics Data System (ADS)

    Aßbichler, Donjá; Asadpour, Manijeh; Heuss-Aßbichler, Soraya; Kunzmann, Thomas

    2016-04-01

    The Eslamy volcano is located on a peninsula at the eastern coast of Urumieh lake, NW Iran. The complex stratovolcano with gentle slope flanks exposes a collapsed caldera in the central part. Specific features are different sanidine rich rocks that occur in form of ejecta and flows. According to the field observations they are products of one volcanic event. XRF measurements show they all have trachytic compositions. Typical for this locality are the large sanidine phenocrysts. In the trachytic flow the sanidine crystals reach average size of ~4 cm embedded in a greenish-blue matrix consisting mainly of crystallized feldspar and subordinate pyroxen. Occasionally feldspar megacrysts of approx. 10 cm were observed. Na content of the sanidine megacrysts varies between 0.05 - 0.5 pfu with higher concentrations in the cores. Furthermore they show oscillatory zoning patterns caused by variations of Ba content (0-0.04 pfu). The matrix of the trachytic flow consist mainly of interlocking sanidine crystals (0.05-0.45 pfu Na) partly with Ba-rich cores containing up to 0.06 pfu Ba. In contrast to the megacrysts they show slightly higher Fe contents (0.025-0.035 pfu). The volcanic ejecta with bombs of approx. 50 cm in size were found in one distinct layer within a pyroclastic horizon. The average diameter of the feldspar phenocrysts is much smaller (0.5-2 cm). Sanidine is the main phase of these rocks (up to 80 %). As mafic phase up to 30 % pyroxen (mainly diospide) ± biotite can be observed. Accessories are magnetite ± apatite ± titanite ± zircon. In contrast to the flow rocks the main phase of the matrix of the ejecta is always glass with higher Fe2O3 (total) contents (up to 6 wt.-%) indicating a fast cooling of the sample due to ejection. They are completely depleted in Ba. In two samples zoned feldspar relicts enclosed in glass show remolten rims. Similar to flow rocks the feldspar phenocrysts of all ejecta show a complex zoning pattern, e.g. three samples expose high

  17. Temperature, size, and depth of the magma reservoir for the Taylor Creek Rhyolite, New Mexico

    USGS Publications Warehouse

    Duffield, W.A.; du Bray, E.A.

    1990-01-01

    The 55 km3 mid-Tertiary Taylor Creek Rhyolite in southwestern New Mexico consists of 20 lava domes and flows. This rhyolite is metaluminous to weakly peraluminous. Compositional zonation in feldspar phenocrysts is very minor and nonsystematic. The compositions of each feldspar species vary little throughout the suite of analyzed samples. This chemical homogeneity of phenocrysts reflects similar whole-rock homogeneity and suggests that the lavas were tapped from a single large reservoir of magma. Ages of sanidine phenocrysts determined using 40Ar/39Ar indicate that the Taylor Creek Rhyolite lavas were emplaced during a period of less than 0.42 my. and possibly less than 0.13 m.y., which is consistent with the single-reservoir scenario. Two-feldspar geothermometry suggests that Taylor Creek Rhyolite phenocrysts crystallized at about 775??C, at an assumed pressure of 2 kbar. Fe-Ti-oxide geothermometry suggests phenocryst growth at about 800??C. Experimental studies suggest that quartz and potassium-feldspar crystals that grow from H2O-undersaturated granitic magmas should exhibit resorption texture, a texture ubiquitous to Taylor Creek Rhyolite quartz and sanidine phenocrysts. We tentatively conclude that the Taylor Creek Rhyolite magma was H2O undersaturated and subliquidus at an unspecified pressure greater than 0.5 kbar during phenocryst growth and that Taylor Creek Rhyolite pyroclastic deposits formed because volatile saturation developed during the ascent of magma to sites of eruption. -from Authors

  18. The pentadehydro-Diels-Alder reaction.

    PubMed

    Wang, Teng; Naredla, Rajasekhar Reddy; Thompson, Severin K; Hoye, Thomas R

    2016-04-28

    In the classic Diels-Alder [4 + 2] cycloaddition reaction, the overall degree of unsaturation (or oxidation state) of the 4π (diene) and 2π (dienophile) pairs of reactants dictates the oxidation state of the newly formed six-membered carbocycle. For example, in the classic Diels-Alder reaction, butadiene and ethylene combine to produce cyclohexene. More recent developments include variants in which the number of hydrogen atoms in the reactant pair and in the resulting product is reduced by, for example, four in the tetradehydro-Diels-Alder (TDDA) and by six in the hexadehydro-Diels-Alder (HDDA) reactions. Any oxidation state higher than tetradehydro (that is, lacking more than four hydrogens) leads to the production of a reactive intermediate that is more highly oxidized than benzene. This increases the power of the overall process substantially, because trapping of the reactive intermediate can be used to increase the structural complexity of the final product in a controllable and versatile manner. Here we report an unprecedented overall 4π + 2π cycloaddition reaction that generates a different, highly reactive intermediate known as an α,3-dehydrotoluene. This species is in the same oxidation state as a benzyne. Like benzynes, α,3-dehydrotoluenes can be captured by various trapping agents to produce structurally diverse products that are complementary to those arising from the HDDA process. We call this new cycloisomerization process a pentadehydro-Diels-Alder (PDDA) reaction-a nomenclature chosen for chemical taxonomic reasons rather than mechanistic ones. In addition to alkynes, nitriles (RC≡N), although non-participants in aza-HDDA reactions, readily function as the 2π component in PDDA cyclizations to produce, via trapping of the α,3-(5-aza)dehydrotoluene intermediates, pyridine-containing products. PMID:27088605

  19. Supporting Evidence for the Astronomically Calibrated Age of Fish Canyon Sanidine

    NASA Astrophysics Data System (ADS)

    Rivera, T. A.; Storey, M.; Zeeden, C.; Kuiper, K.; Hilgen, F.

    2010-12-01

    The relative nature of the 40Ar/39Ar radio-isotopic dating technique requires that the age and error of the monitor mineral be accurately known. The most widely accepted monitor for Cenozoic geochronology is the Fish Canyon sanidine (FCs), whose recommended published ages have varied by up to 2% over the past two decades. To reconcile the discrepancy among recommended ages, researchers have turned to the use of (i) intercalibration experiments with primary argon standards, (ii) cross-calibration with U-Pb ages, and (iii) cross-calibration with sanidine-hosted tephras present in astronomically tuned stratigraphic sections. The increasingly robust quality of the astronomical timescale, with precision better than 0.1% for the last 10 million years, suggests this method of intercalibration as the best way to proceed with addressing the true age of FCs. Recently, Kuiper, et al. (2008) determined an astronomically calibrated age of 28.201 ± 0.046 Ma (2σ), based upon the Moroccan Melilla Basin Messâdit section. Here, we provide independent verification for the Kuiper, et al. (2008) FCs age using sanidines extracted from a tephra intercalated in another Mediterranean-based astronomically tuned section. The direct tuning of this section was achieved through correlation to long (~400 kyr) and short (~100 kyr) eccentricity, followed by tuning of basic sedimentary cycles to precession and summer insolation, using the La2004(1,1) astronomical solution (Laskar, et al., 2004). We employed a Nu Instruments Noblesse multi-collector noble gas mass spectrometer for the 40Ar/39Ar experiments, analyzing single crystals of FCs relative to sanidines from the astronomically dated tephra. The use of the multi-collector instrument allowed us to obtain high precision analyses with a level of precision for fully propagated external errors for FCs near the 0.1% goal of EARTHTIME. The research leading to these results has received funding from the European Community's Seventh Framework

  20. Origins of Stereoselectivity in the trans-Diels-Alder Paradigm

    PubMed Central

    Paton, Robert S.; Mackey, Joel L.; Kim, Woo Han; Lee, Jun Hee; Danishefsky, Samuel J.; Houk, K. N.

    2010-01-01

    The regioselectivity and stereoselectivity aspects of the Diels-Alder/radical hydrodenitration reaction sequence leading to trans-fused ring systems have been investigated with density functional calculations. A continuum of transition structures representing Diels-Alder and hetero-Diels-Alder cycloadditions as well as a sigmatropic rearrangement have been located, and they all lie very close in energy on the potential energy surface. All three pathways are found to be important in the formation of the Diels-Alder adduct. Reported regioselectivities are reproduced by the calculations. The stereoselectivity of radical hydrodenitration of the cis-Diels-Alder adduct is found to be related to the relative conformational stabilities of bicyclic radical intermediates. Overall, the computations provide understanding of the regioselectivities and stereoselectivities of the trans-Diels-Alder paradigm. PMID:20557046

  1. Enantio- and periselective nitroalkene Diels-Alder reaction.

    PubMed

    Narcis, Maurice J; Sprague, Daniel J; Captain, Burjor; Takenaka, Norito

    2012-12-14

    The periselective Diels-Alder reaction of 5-substituted pentamethylcyclopentadienes and nitroethylene has been realized by helical-chiral hydrogen bond donor catalysts. To our knowledge, this represents the first asymmetric catalytic nitroalkene Diels-Alder reaction via activation of nitroalkene, and thus establishes its proof-of-principle. PMID:23104427

  2. Mechanisms and timescales of generating eruptible rhyolitic magmas at Yellowstone caldera from zircon and sanidine geochronology and geochemistry

    USGS Publications Warehouse

    Stelten, Mark; Cooper, Kari M.; Vazquez, Jorge A.; Calvert, Andrew T.; Glessner, Justin G

    2015-01-01

    We constrain the physical nature of the magma reservoir and the mechanisms of rhyolite generation at Yellowstone caldera via detailed characterization of zircon and sanidine crystals hosted in three rhyolites erupted during the (ca. 170 – 70 ka) Central Plateau Member eruptive episode – the most recent post-caldera magmatism at Yellowstone. We present 238U-230Th crystallization ages and trace-element compositions of the interiors and surfaces (i.e., unpolished rims) of individual zircon crystals from each rhyolite. We compare these zircon data to 238U- 230Th crystallization ages of bulk sanidine separates coupled with chemical and isotopic data from single sanidine crystals. Zircon age and trace-element data demonstrate that the magma reservoir that sourced the Central Plateau Member rhyolites was long-lived (150 – 250 kyr) and genetically related to the preceding episode of magmatism, which occurred ca. 256 ka. The interiors of most zircons in each rhyolite were inherited from unerupted material related to older stages of Central Plateau Member magmatism or the preceding late Upper Basin Member magmatism (i.e., are antecrysts). Conversely, most zircon surfaces crystallized near the time of eruption from their host liquids (i.e., are autocrystic). The repeated recycling of zircon interiors from older stages of magmatism demonstrates that sequentially erupted Central Plateau Member rhyolites are genetically related. Sanidine separates from each rhyolite yield 238U-230Th crystallization ages at or near the eruption age of their host magmas, coeval with the coexisting zircon surfaces, but are younger than the coexisting zircon interiors. Chemical and isotopic data from single sanidine crystals demonstrate that the sanidines in each rhyolite are in equilibrium with their host melts, which considered along with their near-eruption crystallization ages suggests that nearly all CPM sanidines are autocrystic. The paucity of antecrystic sanidine crystals relative to

  3. Covalently crosslinked diels-alder polymer networks.

    SciTech Connect

    Bowman, Christopher; Adzima, Brian J.; Anderson, Benjamin John

    2011-09-01

    This project examines the utility of cycloaddition reactions for the synthesis of polymer networks. Cycloaddition reactions are desirable because they produce no unwanted side reactions or small molecules, allowing for the formation of high molecular weight species and glassy crosslinked networks. Both the Diels-Alder reaction and the copper-catalyzed azide-alkyne cycloaddition (CuAAC) were studied. Accomplishments include externally triggered healing of a thermoreversible covalent network via self-limited hysteresis heating, the creation of Diels-Alder based photoresists, and the successful photochemical catalysis of CuAAC as an alternative to the use of ascorbic acid for the generation of Cu(I) in click reactions. An analysis of the results reveals that these new methods offer the promise of efficiently creating robust, high molecular weight species and delicate three dimensional structures that incorporate chemical functionality in the patterned material. This work was performed under a Strategic Partnerships LDRD during FY10 and FY11 as part of a Sandia National Laboratories/University of Colorado-Boulder Excellence in Science and Engineering Fellowship awarded to Brian J. Adzima, a graduate student at UC-Boulder. Benjamin J. Anderson (Org. 1833) was the Sandia National Laboratories point-of-contact for this fellowship.

  4. Analbite - Sanidine Thermodynamic Mixing Properties: Highly Precise HF Solution Calorimetric Data Across A Twenty-Member Crystalline Solution Series

    NASA Astrophysics Data System (ADS)

    Hovis, G. L.

    2013-12-01

    Enthalpies of K-Na mixing for the analbite - sanidine feldspar series were investigated by Hovis (1988, J. Petrology) in the early 80's. That work was based on data at a limited number of compositions, owing to the large sample sizes required for HF solution calorimetric measurements at the time. Thermodynamic mixing properties for mineral series, especially those exhibiting compositionally asymmetric mixing quantities, are best defined when samples at a large number of compositions are utilized. Enabled by the small sample sizes now possible for HF solution calorimetric dissolutions (Hovis et al., 1998, Amer. Mineral.), we revisit feldspar thermodynamic properties, having synthesized an analbite - sanidine series consisting of samples at 20 compositions. Solution calorimetric experiments on these samples at 50 °C in 20.1 wt% HF under isoperibolic conditions have resulted in highly precise calorimetric data (standard deviation per sample averaging 0.06 % of the heat of solution). Although enthalpies of K-Na mixing based on the new data display some degree of compositional asymmetry, with a maximum value of 4.8 kJ/mol at a mole fraction potassium of 0.47, the distribution of enthalpy-of-mixing values remains nearly symmetric with respect to K content. This contrasts significantly with data for Al-Si ordered low albite - microcline crystalline solutions, reinvestigated via synthesis of a 21-member series, which show significantly higher mixing magnitudes and considerably greater asymmetry with respect to composition. The maximization of enthalpies of K-Na mixing at sodic compositions correlates well with the sodic critical compositions for both solvi. The lower mixing magnitudes for analbite - sanidine are consistent with the comparatively lower critical temperature of the analbite - sanidine solvus (e.g., Smith & Parsons, 1974, Mineral. Mag.) relative to that for low albite - microcline (Bachinski & Müller, 1971, J. Petrology). Entropies of K-Na mixing for

  5. Analbite - Sanidine Thermodynamic Mixing Properties: Highly Precise HF Solution Calorimetric Data Across A Twenty-Member Crystalline Solution Series

    NASA Astrophysics Data System (ADS)

    Hovis, G. L.

    2012-12-01

    Enthalpies of K-Na mixing for the analbite - sanidine feldspar series were investigated by Hovis (1988, J. Petrology) in the early 80's. That work was based on data at a limited number of compositions, owing to the large sample sizes required for HF solution calorimetric measurements at the time. Thermodynamic mixing properties for mineral series, especially those exhibiting compositionally asymmetric mixing quantities, are best defined when samples at a large number of compositions are utilized. Enabled by the small sample sizes now possible for HF solution calorimetric dissolutions (Hovis et al., 1998, Amer. Mineral.), we revisit feldspar thermodynamic properties, having synthesized an analbite - sanidine series consisting of samples at 20 compositions. Solution calorimetric experiments on these samples at 50 °C in 20.1 wt% HF under isoperibolic conditions have resulted in highly precise calorimetric data (standard deviation per sample averaging 0.06 % of the heat of solution). Although enthalpies of K-Na mixing based on the new data display some degree of compositional asymmetry, with a maximum value of 4.8 kJ/mol at a mole fraction potassium of 0.47, the distribution of enthalpy-of-mixing values remains nearly symmetric with respect to K content. This contrasts significantly with data for Al-Si ordered low albite - microcline crystalline solutions, reinvestigated via synthesis of a 21-member series, which show significantly higher mixing magnitudes and considerably greater asymmetry with respect to composition. The maximization of enthalpies of K-Na mixing at sodic compositions correlates well with the sodic critical compositions for both solvi. The lower mixing magnitudes for analbite - sanidine are consistent with the comparatively lower critical temperature of the analbite - sanidine solvus (e.g., Smith & Parsons, 1974, Mineral. Mag.) relative to that for low albite - microcline (Bachinski & Müller, 1971, J. Petrology). Entropies of K-Na mixing for

  6. Microwave-Based Reaction Screening: Tandem Retro-Diels-Alder/Diels-Alder Cycloadditions of ortho-Quinol Dimers

    PubMed Central

    Dong, Suwei; Cahill, Kath arine J.; Kang, Moon -Il; Colburn, Nancy H.; Henrich, Curtis J.; Wilson, Jennifer A.; Beutler, John A.; Johnson, Richard P.; Porco, John A.

    2011-01-01

    We have accomplished a parallel screen of cycloaddition partners for ortho-quinols utilizing a plate-based microwave system. Microwave irradiation improves the efficiency of retro-Diels-Alder/Diels-Alder cascades of ortho-quinol dimers which generally proceed in a diastereoselective fashion. Computational studies indicate that asynchronous transition states are favored in Diels-Alder cycloadditions of ortho-quinols. Subsequent biological evaluation of a collection of cycloadducts has identified an inhibitor of activator protein-1 (AP-1), an oncogenic transcription factor. PMID:21942286

  7. Reinvestigation of the annite = sanidine + magnetite + H2 reaction using the fH2-sensor technique

    USGS Publications Warehouse

    Cygan, G.L.; Chou, I.-Ming; Sherman, David M.

    1996-01-01

    The decomposition of the iron mica, annite, to sanidine plus magnetite and vapor, KFe3AlSi3O10(OH)2 = KAlSi3O8 + Fe3O4 + H2, has been reexamined experimentally with the use of a variety of buffers coupled with fH2 sensors at 2 kbar and between 400 and 840 ??C. Various capsule configurations were used in this study to delineate the equilibrium constant for this reaction in conjunction with 57Fe Mo??ssbauer spectroscopy measurements to monitor the oxy-annite component in mica in selected experiments. Results at the most reducing and highest temperature conditions of this study extend the annite stability field to higher temperature and fo2 values than those defined in previous work. Lower temperature results indicate that the annite-sanidine-magnetite stability boundary does not intersect the hematite + magnetite + H2O buffer at 400??C as previously reported but rather is subparallel to the buffer curve at lower fo2 values. The equilibrium fH2 (in bars) for the assemblage annite + sanidine + magnetite + vapor at 2 kbar and between 400 and 840 ??C can be described by the relation log fH2 (??0.08) = 13.644 - (17368/T) + (5.168 ?? 106)/T2, where T is temperature in kelvins.

  8. Variations in trace element partition coefficients in sanidine in the Cerro Toledo Rhyolite, Jemez Mountains, New Mexico: Effects of composition, temperature, and volatiles

    SciTech Connect

    Stix, J. ); Gorton, M.P. )

    1990-10-01

    Trace element partition coefficients have been measured for one plagioclase and five sanidine mineral separates from the Cerro Toledo Rhyolite, New Mexico. Sanidine partition coefficients vary substantially and systematically within the Cerro Toledo Rhyolite. Partition coefficients for Ca, Sr, Zn, La, and Eu are lowest in the most evolved rhyolites, whereas Sm and HREE partition coefficients are highest. Rubidium partition coefficients remain constant, while those for Ba, Ce, and Th are variable. Variations of the Sr, Zn, La, and Eu partition coefficients are correlated with the Ca contents and partition coefficients of the sanidines. Calcium may have controlled the distribution of these elements in the sanidine by modifying the feldspar structure. The low Ca partition coefficients in sanidines for the most evolved rhyolites may be the consequence of modification of the melt structure, possibly due to increased volatile contents at the top of the magma chamber(s) during evolution of the Cerro Toledo Rhyolite. The Zn and La partition coefficients between sanidine and melt also may have been controlled by this change in melt structure. Modelling using major elements and the constant Rb partition coefficient for sanidine indicates 70% crystallization of magma during Cerro Toledo Rhyolite time by removal of 68% sanidine and 32% quartz. Estimates of the volume (1) of initial parental magma and (2) of the magma that crystallized during this period are 11,670 km{sup 3} and 8,170 km{sup 3}, respectively. The average intrusion rate of silicic magma during Cerro Toledo Rhyolite activity was 35 {times} 10{sup {minus}3} km{sup 3}/a.

  9. Single-crystal 40Ar/39Ar incremental heating reveals bimodal sanidine ages in the Bishop Tuff

    NASA Astrophysics Data System (ADS)

    Andersen, N. L.; Jicha, B. R.; Singer, B. S.

    2015-12-01

    The 650 km3 Bishop Tuff (BT) is among the most studied volcanic deposits because it is an extensive marker bed deposited just after the Matuyama-Brunhes boundary. Reconstructions of the vast BT magma reservoir from which high-silica rhyolite erupted have long influenced thinking about how large silicic magma systems are assembled, crystallized, and mixed. Yet, the longevity of the high silica rhyolitic melt and exact timing of the eruption remain controversial due to recent conflicting 40Ar/39Ar sanidine vs. SIMS and ID-TIMS U-Pb zircon dates. We have undertaken 21 40Ar/39Ar incremental heating ages on 2 mm BT sanidine crystals from pumice in 3 widely separated outcrops of early-erupted fall and flow units. Plateau ages yield a bimodal distribution: a younger group has a mean of 766 ka and an older group gives a range between 772 and 782 ka. The younger population is concordant with the youngest ID-TIMS and SIMS U-Pb zircon ages recently published, as well as the astronomical age of BT in marine sediment. Of 21 crystals, 17 yield older, non-plateau, steps likely affected by excess Ar that would bias traditional 40Ar/39Ar total crystal fusion ages. The small spread in older sanidine ages, together with 25+ kyr of pre-eruptive zircon growth, suggest that the older sanidines are not partially outgassed xenocrysts. A bimodal 40Ar/39Ar age distribution implies that some fraction of rhyolitic melt cooled below the Ar closure temperature at least 10 ky prior to eruption. We propose that rapid "thawing" of a crystalline mush layer released older crystals into rhyolitic melt from which sanidine also nucleated and grew immediately prior to the eruption. High precision 40Ar/39Ar dating can thus provide essential information on thermo-physical processes at the millenial time scale that are critical to interpreting U-Pb zircon age distributions that are complicated by large uncertainties associated with zircon-melt U-Th systematics.

  10. Tracking the Evolution of Young Mush at Long Valley through High Spatial Resolution U-Th Zircon Dating and Sanidine Geospeedometry of Inyo Domes Rhyolite

    NASA Astrophysics Data System (ADS)

    Matthews, N. E.; Vazquez, J. A.

    2012-12-01

    The Inyo Domes rhyolitic chain, which erupted at ca. 1350 CE from a fissure near the northern boundary of Long Valley caldera, California, provides an example of rhyolitic mush that has been episodically tapped over an interval of hundreds of thousands of years1. Our new data reveal that the mixed magmas each have unique crystallization histories with varying residence times but also exhibit evidence for final mixing within a hundred years of final eruption. In order to evaluate the timing of crystallization and history of rejuvenation, we present ion microprobe 238U-230Th zircon geochronology coupled with geospeedometry from trace-element zoning data for crystals extracted from the Inyo Domes and older related rhyolite. The South Deadman and Glass Creek domes display complex magma mixing features, involving a coarsely-porphyritic (CP) and finely-porphyritic (FP) rhyolite which are distinct in their mineralogy, chemistry and textures. The CP lava is similar in texture and mineralogy to the ~100 ka Deer Mountain rhyolite, situated to the south of the Inyo chain. In contrast, the FP lava may relate to magma sourced in the Mono chain to the north of the caldera2. Mafic enclaves are commonly found within CP lava, suggesting late stage mixing and heating episodes in the crystal mush. High-resolution records of zircon crystallization were obtained using SHRIMP-RG analyses of unpolished rims for crystals embedded in indium, along with sectioned crystals exposing interiors. Deer Mountain zircons have rims that grew immediately prior to eruption (~100 ka) and cores that are significantly older (~250 ka), providing evidence for zircon growth during protracted evolution of the mush body. South Deadman Dome CP rhyolite contains three populations of zircon, with apparent populations of ~30 ka, ~100 ka, and >200 ka, the latter two correlating to populations sampled by the earlier Deer Mountain eruption. Zircons extracted from FP rhyolite return near-eruption ages (~1 ka) and do

  11. 1. EAGLE CREEK RECREATION AREA, VIEW OF EAGLE CREEK TRAIL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. EAGLE CREEK RECREATION AREA, VIEW OF EAGLE CREEK TRAIL REGISTRY BOOTH. - Historic Columbia River Highway, Eagle Creek Recreation Area, Historic Columbia River Highway at Eagle Creek, Troutdale, Multnomah County, OR

  12. 3D Photofixation Lithography in Diels–Alder Networks

    PubMed Central

    Adzima, Brian J.; Kloxin, Christopher J.; DeForest, Cole A.; Anseth, Kristi S.

    2013-01-01

    3D structures were written and developed in a crosslinked polymer initially formed by a Diels–Alder reaction. Unlike conventional liquid resists, small features cannot sediment, as the reversible crosslinks function as a support, and the modulus of the material is in the MPa range at room temperature. The support structure, however, can be easily removed by heating the material which depolymerizes the polymer into a mixture of low-viscosity monomers. Complex shapes were written into the polymer network using two-photon techniques to spatially control the photoinitiation and subsequent thiol–ene reaction to selectively convert the Diels–Alder adducts into irreversible crosslinks. PMID:23080017

  13. Isotopic dating of Lava Creek B tephra in terrace deposits along the Wind River, Wyoming--Implications for post 0. 6 Ma uplift of the Yellowstone hotspot

    SciTech Connect

    Izett, G.A.; Pierce, K.L.; Naeser, N.D. ); Jaworowski, C. . Dept. of Geology and Geophysics)

    1992-01-01

    Along the Wind River near Kinnear (Pavillon quadrangle), a meter-thick tephra layer occurs near the middle of a main-stem gravel deposit about 100 m above the river. On Muddy Ridge 25 km east of Kinnear, a Lava Creek B tephra layer occurs at the base of a terrace deposit about 100 m above Muddy Creek. Another Lava Creek B tephra site 67 km northwest and upstream from Kinnear occurs within main-stem gravels of a terrace deposit 145 m above the river. This upstream increase of 45 m of the tephra horizon raises the concern that the two tephra layers might not be of the same age. All three tephras contain the same assemblage of phenocrysts as that in the Lava Creek Tuff, Member B in Yellowstone National Park and the Lava Creek B volcanic ash bed of the Western U.S., and therefore they are arguably correlatives. The authors confirmed this petrographic correlation by isotopic dating of sanidine crystals recovered from cm-size pumice lapilli in the Kinnear tephra and from coarse-grained tephra at the Muddy Creek site. Laser total-fusion Ar-40-Ar-39 ages of sanidine from the two sites are coeval, 0.66[plus minus]0.01 Ma and 0.67[plus minus]0.01 Ma at Muddy Creek. Conventional K-Ar dating of sanidine from the tephra at the Cl453 site resulted in an age of 0.60[plus minus]0.02 Ma. Glass-mantled zircon crystals from the Cl453 site yielded a fission-track age of 0.67[plus minus]0.16 Ma. These isotopic ages are compatible with conventional K-Ar, Ar-40-Ar-39, and fission-track ages of the Lava Creek Tuff, Member B in Yellowstone National Park and other occurrences of Lava Creek B ash beds. The authors suggest that the terrace deposit that contains the Lava Creek B tephra rises from the Kinnear site northwest up the Wind River as a result of Quaternary uplift in the area of the Yellowstone hotspot.

  14. Restoring Fossil Creek

    ERIC Educational Resources Information Center

    Flaccus, Kathleen; Vlieg, Julie; Marks, Jane C.; LeRoy, Carri J.

    2004-01-01

    Fossil Creek had been dammed for the past 90 years, and plans were underway to restore the stream. The creek runs through Central Arizona and flows from the high plateaus to the desert, cutting through the same formations that form the Grand Canyon. This article discusses the Fossil Creek monitoring project. In this project, students and teachers…

  15. 61. Photocopy of Engine Room Floor Plan, White Alder. The ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    61. Photocopy of Engine Room Floor Plan, White Alder. The Niagara Shipbuilding Corp. Engineering Department, Buffalo, New York. Coast Guard Headquarters Drawing No. 540-WAGL-1604-10, dated February 1943; revised January 1963. Original drawing property of the U.S. Coast Guard. - U.S. Coast Guard Cutter WHITE HEATH, USGS Integrated Support Command Boston, 427 Commercial Street, Boston, Suffolk County, MA

  16. N2-fixing red alder indirectly accelerates ecosystem nitrogen cycling

    USGS Publications Warehouse

    Perakis, Steven S.; Matkins, Joselin J.; Hibbs, David E.

    2012-01-01

    Symbiotic N2-fixing tree species can accelerate ecosystem N dynamics through decomposition via direct pathways by producing readily decomposed leaf litter and increasing N supply to decomposers, as well as via indirect pathways by increasing tissue and detrital N in non-fixing vegetation. To evaluate the relative importance of these pathways, we compared three-year decomposition and N dynamics of N2-fixing red alder leaf litter (2.34 %N) to both low-N (0.68 %N) and high-N (1.21 %N) litter of non-fixing Douglas-fir, and decomposed each litter source in four forests dominated by either red alder or Douglas-fir. We also used experimental N fertilization of decomposition plots to assess elevated N availability as a potential mechanism of N2-fixer effects on litter mass loss and N dynamics. Direct effects of N2-fixing red alder on decomposition occurred primarily as faster N release from red alder than Douglas-fir litter, but direct increases in N supply to decomposers via fertilization did not stimulate decomposition of any litter. Fixed N indirectly influenced detrital dynamics by increasing Douglas-fir tissue and litter N concentrations, which accelerated litter N release without accelerating mass loss. By increasing soil N, tissue N, and the rate of N release from litter of non-fixers, we conclude that N2-fixing vegetation can indirectly foster plant-soil feedbacks that contribute to the persistence of elevated N availability in terrestrial ecosystems.

  17. Continuous Flow of Nitroso Diels-Alder Reaction

    PubMed Central

    2015-01-01

    Our flow reaction systems have provided quantitative yields of nitroso Diels-Alder products with no byproducts in cases of cyclic dienes without temperature and pressure controls. Additionally, the reaction times were significantly shortened by using homogeneous catalyst (CuCl) or heterogeneous reagent (MnO2) in comparison with batch reaction. PMID:26138229

  18. High stereoselectivity on low temperature Diels-Alder reactions

    PubMed Central

    da Silva Filho, Luiz Carlos; Lacerda Júnior, Valdemar; Constantino, Mauricio Gomes; da Silva, Gil Valdo José; Invernize, Paulo Roberto

    2005-01-01

    We have found that some of the usually poor dienophiles (2-cycloenones) can undergo Diels-Alder reaction at -78°C with unusually high stereoselectivity in the presence of niobium pentachloride as a Lewis acid catalyst. A remarkable difference in reaction rates for unsubstituted and α- or β-methyl substituted 2-cycloenones was also observed. PMID:16542029

  19. High stereoselectivity on low temperature Diels-Alder reactions.

    PubMed

    da Silva Filho, Luiz Carlos; Lacerda Júnior, Valdemar; Constantino, Mauricio Gomes; da Silva, Gil Valdo José; Invernize, Paulo Roberto

    2005-01-01

    We have found that some of the usually poor dienophiles (2-cycloenones) can undergo Diels-Alder reaction at -78 degrees C with unusually high stereoselectivity in the presence of niobium pentachloride as a Lewis acid catalyst. A remarkable difference in reaction rates for unsubstituted and alpha- or beta-methyl substituted 2-cycloenones was also observed. PMID:16542029

  20. Enhanced stereocontrol in Diels-Alder reactions of chiral dienols.

    PubMed

    Cayzer, Tory N; Miller, Natalie A; Paddon-Row, Michael N; Sherburn, Michael S

    2006-05-21

    This combined experimental-computational investigation demonstrates that the presence of a removable bromine substituent on a diene leads to complete pi-diastereofacial and endo/exo stereoselection in both intermolecular and intramolecular Diels-Alder reactions. The influence of the bromine upon stereoselectivity is dramatic: the cycloaddition of nonbrominated precursor 18E, for example, gives four diastereomeric products in a 55:13:16:16 ratio; the bromine-containing analogue gives one stereoisomer within the limits of detection. The examination of B3LYP/6-31+G(d) transition structures allows an interpretation of these experimental findings. A method for the completely stereoselective synthesis of complimentary diastereomeric products (30Z and 31Z) from the same simple starting materials (28 and 2) is reported. Discrepancies between calculation and experiment in an earlier investigation into the Diels-Alder reaction are explained. PMID:16688346

  1. Recent Progress in Dehydro(genative) Diels-Alder Reaction.

    PubMed

    Li, Wenbo; Zhou, Liejin; Zhang, Junliang

    2016-01-26

    In recent years, remarkable progress has been made in dehydro or dehydrogenative Diels-Alder (D-A) reactions. This Minireview gives an overview of the major two strategies for dehydro(genative) Diels-Alder reactions, which differ in dehydrogenation and D-A cyclization sequence. Reactions in which D-A cycloaddition is followed by dehydrogenation are useful methods for the synthesis of various aromatic compounds, whereas advancements in dehydro genative procedures with oxidants or catalysts prior to D-A cycloaddition offer yet further new routes to functionalized cycloadducts. Recent leading findings are highlighted and the current state of the art, scope, and limitations of these processes are discussed in this Minireview. PMID:26786814

  2. Shell Creek Summers

    ERIC Educational Resources Information Center

    Seier, Mark; Goedeken, Suzy

    2005-01-01

    In 2002 Shell Creek Watershed Improvement Group turned to the Newman Grove Public Schools' science department to help educate the public on water quality in the watershed and to establish a monitoring system that would be used to improve surface and groundwater quality in the creek's watershed. Nebraska Department of Environmental Quality provided…

  3. First-principles calibration of 40Ar/39Ar mineral standards and complete extraction of 40Ar* from sanidine

    NASA Astrophysics Data System (ADS)

    Morgan, L. E.; Kuiper, K.; Mark, D.; Postma, O.; Villa, I. M.; Wijbrans, J. R.

    2010-12-01

    40Ar/39Ar geochronology relies on comparing argon isotopic data for unknowns to those for knowns. Mineral standards used as neutron fluence monitors must be dated by the K-Ar method (or at least referenced to a mineral of known K-Ar age). The commonly used age of 28.02 ± 0.28 Ma for the Fish Canyon sanidine (FCs) (Renne et al., 1998) is based upon measurements of radiogenic 40Ar in GA1550 biotite (McDougall and Roksandic, 1974), but underlying full data were not published (these measurements were never intended for use as an international standard), so uncertainties are difficult to assess. Recent developments by Kuiper et al. (2008) and Renne et al. (2010) are limited by their reliance on the accuracy of other systems. Modern technology should allow for more precise and accurate calibration of primary K-Ar and 40Ar/39Ar standards. From the ideal gas law, the number of moles of 40Ar in a system can be calculated from measurements of pressure, volume, and temperature. Thus we have designed and are proceeding to build a pipette system to introduce well-determined amounts of 40Ar into noble gas extraction lines and mass spectrometers. This system relies on components with calibrations traceable to SI unit prototypes, including a diaphragm pressure gauge (MKS Instruments), thermocouples, and a “slug” of an accurately determined volume to be inserted into the reservoir for volume determinations of the reservoir and pipette. The system will be renewable, with a lifetime of ca. 1 month for gas in the reservoir, and portable, to permit interlaboratory calibrations. The quantitative extraction of 40Ar* from the mineral standard is of highest importance; for sanidine standards this is complicated by high melt viscosity during heating. Experiments adding basaltic “zero age glass” (ZAG) to decrease melt viscosity are underway. This has previously been explored by McDowell (1983) with a resistance furnace, but has not been quantitatively addressed with laser heating

  4. 40Ar/39Ar age of the Manson impact structure, Iowa, and correlative impact ejecta in the Crow Creek member of the Pierre Shale (Upper Cretaceous), South Dakota and Nebraska

    USGS Publications Warehouse

    Izett, G.A.; Cobban, W.A.; Dalrymple, G.B.; Obradovich, J.D.

    1998-01-01

    A set of 34 laser total-fusion 40Ar/39Ar analyses of sanidine from a melt layer in crater-fill deposits of the Manson impact structure in Iowa has a weighted-mean age of 74.1 ?? 0.1 Ma. This age is about 9.0 m.y. older than 40Ar/39Ar ages of shocked microcline from the Manson impact structure reported previously by others. The 74.1 Ma age of the sanidine, which is a melt product of Precambrian microcline clasts, indicates that the Manson impact structure played no part in the Cretaceous-Tertiary (K-T) mass extinction at 64.5 Ma. Moreover, incremental-heating 40Ar/39Ar ages of the sanidine show that it is essentially free of excess 40Ar and has not been influenced by postcrystallization heating or alteration. An age spectrum of the matrix of the melt layer shows effects of 39Ar recoil, including older ages in the low-temperature increments and younger ages in the high-temperature increments. At 17 places in eastern South Dakota and Nebraska, shocked quartz and feldspar grains are concentrated in the lower part of the Crow Creek Member of the Pierre Shale (Upper Cretaceous). The grains are largest (3.2 mm) in southeastern South Dakota and decrease in size (0.45 mm) to the northwest, consistent with the idea that the Manson impact structure was their source. The ubiquitous presence of shocked grains concentrated in a thin calcarenite at the base of the Crow Creek Member suggests it is an event bed recording an instant of geologic time. Ammonites below and above the Crow Creek Member limit its age to the zone of Didymoceras nebrascense of earliest late Campanian age. Plagioclase from a bentonite bed in this zone in Colorado has a 40Ar/39Ar age of 74.1 ?? 0.1 Ma commensurate with our sanidine age of 74.1 Ma for the Manson impact structure. 40Ar/39Ar ages of bentonite beds below and above the Crow Creek are consistent with our 74.1 ?? 0.1 Ma age for the Manson impact structure and limit its age to the interval ?? 74.5 0.1 to 73.8 ?? 0.1 Ma. Recently, two origins for the

  5. Alder (alnus crispa) effects on soils in ecosystems of the agashashok river valley, northwest Alaska

    USGS Publications Warehouse

    Rhoades, C.; Oskarsson, H.; Binkley, D.; Stottlemyer, B.

    2001-01-01

    At the northern limit of the boreal forest biome, alder (Alnus crispa [Ait.] Pursh) shrubs occur in a variety of ecosystems. We assessed the effects of individual alder shrubs on soil properties and understory plant tissue nitrogen in floodplain terraces, valley slopes and tussock tundra ridges. The three ecosystems differed with respect to soil properties and abiotic conditions and supported distinct plant communities. Alder increased resin-exchangeable soil N and NO3 production significantly in each ecosystem. The greatest difference between alder canopy and surrounding soil NO3 measured both under field and laboratory conditions occured in floodplain sites. The shrub effect on soil pH and soil organic matter was greatest on tundra ridges. Alder shrubs also influenced the nitrogen nutrition of plants growing beneath their canopies. Plants growing below alder canopies had higher foliar nitrogen concentration and natural abundance 15N composition and lower carbon to nitrogen ratio than open-grown plants. Similar to soil N availability, understory plant leaf chemistry responded more to alder on floodplains than on slope or tundra ecosystems. This pattern suggests that understory plants rely more heavily on alder-fixed-N in this resource-poor ecosystem.

  6. Enantioselective and regioselective pyrone Diels-Alder reactions of vinyl sulfones: total synthesis of (+)-cavicularin.

    PubMed

    Zhao, Peng; Beaudry, Christopher M

    2014-09-22

    The total synthesis of (+)-cavicularin is described. The synthesis features an enantio- and regioselective pyrone Diels-Alder reaction of a vinyl sulfone to construct the cyclophane architecture of the natural product. The Diels-Alder substrate was prepared by a regioselective one-pot three-component Suzuki reaction of a non-symmetric dibromoarene. PMID:25082270

  7. Compositional gradients in large reservoirs of silicic magma as evidenced by ignimbrites versus Taylor Creek Rhyolite lava domes

    USGS Publications Warehouse

    Duffield, W.A.; Ruiz, J.

    1992-01-01

    The Taylor Creek Rhyolite of southwest New Mexico consists of 20 lava domes and flows that were emplaced during a period of a few thousand years or less in late Oligocene time. Including genetically associated pyroclastic deposits, which are about as voluminous as the lava domes and flows, the Taylor Creek Rhyolite represents roughly 100 km3 of magma erupted from vents distributed throughout an area of several hundred square kilometers. Major-element composition is metaluminous to weakly peraluminous high-silica rhyolite and is nearly constant throughout the lava field. The magma reservoir for the Taylor Creek Rhyolite was vertically zoned in trace elements, 87Sr/86Sr, and phenocryst abundance and size. Mean trace-element concentrations, ranges in concentrations, and element-pair correlations are similar to many subalkaline silicic ignimbrites. However, the polarity of the zonation was opposite that in reservoirs for ignimbrites, for most constituents. For example, compared to the Bishop Tuff, only 87Sr/86Sr and Sc increased upward in both reservoirs. Quite likely, a dominant but nonerupted volume of the magma reservoir for the Taylor Creek Rhyolite was zoned like that for the Bishop Tuff, whereas an erupted, few-hundred-meter-thick cap on the magma body was variably contaminated by roof rocks whose contribution to this part of the magma system moderated relatively extreme trace-element concentrations of uncontaminated Taylor Creek Rhyolite but did not change the sense of correlation for most element pairs. The contaminant probably was a Precambrian rock of broadly granitic composition and with very high 87Sr/86Sr. Although examples apparently are not yet reported in the literature, evidence for a similar thin contaminated cap on reservoirs for large-volume silicic ignimbrites may exist in the bottom few meters of ignimbrites or perhaps only in the pumice fallout that normally immediately precedes ignimbrite emplacement. 87Sr/86Sr in sanidine phenocrysts of the

  8. Compositional gradients in large reservoirs of silicic magma as evidenced by ignimbrites versus Taylor Creek Rhyolite lava domes

    NASA Astrophysics Data System (ADS)

    Duffield, Wendell A.; Ruiz, Joaquin

    1992-04-01

    The Taylor Creek Rhyolite of southwest New Mexico consists of 20 lava domes and flows that were emplaced during a period of a few thousand years or less in late Oligocene time. Including genetically associated pyroclastic deposits, which are about as voluminous as the lava domes and flows, the Taylor Creek Rhyolite represents roughly 100 km3 of magma erupted from vents distributed throughout an area of several hundred square kilometers. Major-element composition is metaluminous to weakly peraluminous high-silica rhyolite and is nearly constant throughout the lava field. The magma reservoir for the Taylor Creek Rhyolite was vertically zoned in trace elements, 87Sr/86Sr, and phenocryst abundance and size. Mean trace-element concentrations, ranges in concentrations, and element-pair correlations are similar to many subalkaline silicic ignimbrites. However, the polarity of the zonation was opposite that in reservoirs for ignimbrites, for most constituents. For example, compared to the Bishop Tuff, only 87Sr/86Sr and Sc increased upward in both reservoirs. Quite likely, a dominant but nonerupted volume of the magma reservoir for the Taylor Creek Rhyolite was zoned like that for the Bishop Tuff, whereas an erupted, few-hundred-meter-thick cap on the magma body was variably contaminated by roof rocks whose contribution to this part of the magma system moderated relatively extreme trace-element concentrations of uncontaminated Taylor Creek Rhyolite but did not change the sense of correlation for most element pairs. The contaminant probably was a Precambrian rock of broadly granitic composition and with very high 87Sr/86Sr. Although examples apparently are not yet reported in the literature, evidence for a similar thin contaminated cap on reservoirs for large-volume silicic ignimbrites may exist in the bottom few meters of ignimbrites or perhaps only in the pumice fallout that normally immediately precedes ignimbrite emplacement. 87Sr/86Sr in sanidine phenocrysts of the

  9. Ectomycorrhizal root development in wet Alder carr forests in response to desiccation and eutrophication.

    PubMed

    Baar, J; Bastiaans, T; van de Coevering, M A; Roelofs, J G M

    2002-06-01

    Effects of desiccation and eutrophication on ectomycorrhizal (ECM) root development in wet Alder carr forests in The Netherlands were studied. In northwestern Europe, wet Alder carr forests are found mostly in peatlands and along streams, forming an important component of wetland ecosystems. The dominant tree species in wet Alder carr forests is Alnus glutinosa (L.) Gaertn. (Black alder), which associates with ectomycorrhizal fungi. During recent decades, wet Alder carr forests in Europe have declined because of desiccation and eutrophication, particularly in The Netherlands. In the present study, the number of root tips of A. glutinosa trees was highest in an undisturbed wet Alder carr forest in a peatland area. Eutrophication in the peatland area significantly inhibited ectomycorrhizal (ECM) root development of A. glutinosa. In the eutrophied forest, ECM root tips were observed only close to A. glutinosa trees growing on hummocks. The concentrations of nitrate and potassium in soil water of the eutrophied forest were significantly higher than in the undisturbed forest, while magnesium and iron concentrations and the pH were significantly lower. The number of ECM root tips of A. glutinosa in a desiccated forest along a stream was generally lower than in an undisturbed wet Alder carr forest on waterlogged soil in the same area. The sulphate concentration in soil water in the desiccated forest was significantly higher than in the forest on waterlogged soil. ECM root development of A. glutinosa may have been negatively affected by the chemical composition of the soil water. PMID:12072985

  10. The Taylor Creek Rhyolite of New Mexico: a rapidly emplaced field of lava domes and flows

    USGS Publications Warehouse

    Duffield, W.A.; Dalrymple, G.B.

    1990-01-01

    The Tertiary Taylor Creek Rhyolite of southwest New Mexico comprises at least 20 lava domes and flows. Each of the lavas was erupted from its own vent, and the vents are distributed throughout a 20 km by 50 km area. The volume of the rhyolite and genetically associated pyroclastic deposits is at least 100 km3 (denserock equivalent). The rhyolite contains 15%-35% quartz, sanidine, plagioclase, ??biotite, ??hornblende phenocrysts. Quartz and sanidine account for about 98% of the phenocrysts and are present in roughly equal amounts. With rare exceptions, the groundmass consists of intergrowths of fine-grained silica and alkali feldspar. Whole-rock major-element composition varies little, and the rhyolite is metaluminous to weakly peraluminous; mean SiO2 content is about 77.5??0.3%. Similarly, major-element compositions of the two feldsparphenocryst species also are nearly constant. However, whole-rock concentrations of some trace-elements vary as much as several hundred percent. Initial radiometric age determinations, all K-Ar and fission track, suggest that the rhyolite lava field grew during a period of at least 2 m.y. Subsequent 40Ar/39Ar ages indicate that the period of growth was no more than 100 000 years. The time-space-composition relations thus suggest that the Taylor Creek Rhyolite was erupted from a single magma reservoir whose average width was at least 30 km, comparable in size to several penecontemporaneous nearby calderas. However, this rhyolite apparently is not related to a caldera structure. Possibly, the Taylor Creek Phyolite magma body never became sufficiently volatile rich to produce a large-volume pyroclastic eruption and associated caldera collapse, but instead leaked repeatedly to feed many relatively small domes and flows. The new 40Ar/39Ar ages do not resolve preexisting unknown relative-age relations among the domes and flows of the lava field. Nonetheless, the indicated geologically brief period during which Taylor Creek Rhyolite magma was

  11. The Taylor Creek Rhyolite of New Mexico: a rapidly emplaced field of lava domes and flows

    NASA Astrophysics Data System (ADS)

    Duffield, Wendell A.; Dalrymple, G. Brent

    1990-08-01

    The Tertiary Taylor Creek Rhyolite of southwest New Mexico comprises at least 20 lava domes and flows. Each of the lavas was erupted from its own vent, and the vents are distributed throughout a 20 km by 50 km area. The volume of the rhyolite and genetically associated pyroclastic deposits is at least 100 km3 (denserock equivalent). The rhyolite contains 15% 35% quartz, sanidine, plagioclase, ±biotite, ±hornblende phenocrysts. Quartz and sanidine account for about 98% of the phenocrysts and are present in roughly equal amounts. With rare exceptions, the groundmass consists of intergrowths of fine-grained silica and alkali feldspar. Whole-rock major-element composition varies little, and the rhyolite is metaluminous to weakly peraluminous; mean SiO2 content is about 77.5±0.3%. Similarly, major-element compositions of the two feldsparphenocryst species also are nearly constant. However, whole-rock concentrations of some trace-elements vary as much as several hundred percent. Initial radiometric age determinations, all K-Ar and fission track, suggest that the rhyolite lava field grew during a period of at least 2 m.y. Subsequent 40Ar/39Ar ages indicate that the period of growth was no more than 100 000 years. The time-space-composition relations thus suggest that the Taylor Creek Rhyolite was erupted from a single magma reservoir whose average width was at least 30 km, comparable in size to several penecontemporaneous nearby calderas. However, this rhyolite apparently is not related to a caldera structure. Possibly, the Taylor Creek Phyolite magma body never became sufficiently volatile rich to produce a large-volume pyroclastic eruption and associated caldera collapse, but instead leaked repeatedly to feed many relatively small domes and flows. The new 40Ar/39Ar ages do not resolve preexisting unknown relative-age relations among the domes and flows of the lava field. Nonetheless, the indicated geologically brief period during which Taylor Creek Rhyolite magma was

  12. BEAVER CREEK WILDERNESS, KENTUCKY.

    USGS Publications Warehouse

    Englund, K.J.; Hammack, R.W.

    1984-01-01

    The Beaver Creek Wilderness, Kentucky, was studied. Coal is the most important mineral resource in the Beaver Creek Wilderness. The coal is tentatively ranked as high-volatile A bituminous, and like coal of this rank in nearby mining areas, it is primarily suitable for use as steam coal. The coal resources are estimated to total 8. 31 million short tons in beds greater than 14 in. thick. Nonmetallic minerals present in the Wilderness include limestone, shale, clay, and sandstone; these commodities are abundant outside the wilderness. The information available is not adequate for the assessment of the oil and gas resource potential of the Beaver Creek Wilderness. There is little likelihood for the occurrence of metallic mineral resources.

  13. Beaver Creek Wilderness, Kentucky

    SciTech Connect

    Englund, K.J.; Hammack, R.W.

    1984-01-01

    The Beaver Creek Wilderness, Kentucky, was studied in 1980 by the USGS and USBM. Coal is the most important mineral resource in the Beaver Creek Wilderness. The coal is tentatively ranked as high-volatile A bituminous, and like coal of this rank in nearby mining areas, it is primarily suitable for use as steam coal. The coal resources are estimated to total 8.31 million short tons in beds greater than 14 in. thick. Nonmetallic minerals present in the Wilderness include limestone, shale, clay, and sandstone; these commodities are abundant outside the wilderness. The information available is not adequate for the assessment of the oil and gas resource potential of the Beaver Creek Wilderness. There is little likelihood for the occurrence of metallic mineral resources.

  14. Electron transfer-initiated Diels-Alder cycloadditions of 2'-hydroxychalcones.

    PubMed

    Cong, Huan; Ledbetter, Dustin; Rowe, Gerard T; Caradonna, John P; Porco, John A

    2008-07-23

    An efficient approach to cyclohexenyl chalcones employing highly electron rich 2'-hydroxychalcone dienophiles via electron transfer-initiated Diels-Alder cycloaddition is described. Using the methodology, the total synthesis of nicolaiodesin C has been accomplished. PMID:18576647

  15. Boulder Creek Study

    ERIC Educational Resources Information Center

    Bingaman, Deirdre; Eitel, Karla Bradley

    2010-01-01

    Boulder Creek runs literally in the backyard of Donnelly Elementary School and happens to be on the EPA list of impaired water bodies. Therefore, a unique opportunity for problem solving opened the door to an exciting chance for students to become scientists, while also becoming active in their community. With the help of the Idaho Department of…

  16. WILLOW CREEK RECLAMATION PROJECT

    EPA Science Inventory

    Working in cooperation with the EPA, Colorado Division of Minerals and Geology, and others, the Willow Creek Reclamation Committee (WCRC) will investigate the sources and character of water entering the mine workings on the Amethyst vein near the town of Creede, Colorado. Activi...

  17. The Paint Creek Project.

    ERIC Educational Resources Information Center

    Northrop, David; Vonck, Beth

    1998-01-01

    Describes a summer program project designed and conducted by a mixed-age group of elementary children. Students collected data to determine whether a local stream was polluted, and interpretations of the data varied. An informational video about the project and the creek was produced. (PVD)

  18. Heavy metal stress in alders: Tolerance and vulnerability of the actinorhizal symbiosis.

    PubMed

    Bélanger, Pier-Anne; Bellenger, Jean-Philippe; Roy, Sébastien

    2015-11-01

    Alders have already demonstrated their potential for the revegetation of both mining and industrial sites. These actinorhizal trees and shrubs and the actinobacteria Frankia associate in a nitrogen-fixing symbiosis which could however be negatively affected by the presence of heavy metals, and accumulate them. In our hydroponic assay with black alders, quantification of the roots and shoots metal concentrations showed that, in the absence of stress, symbiosis increases Mo and Ni root content and simultaneously decreases Mo shoot content. Interestingly, the Mo shoot content also decreases in the presence of Ni, Cu, Pb, Zn and Cd for symbiotic alders. In symbiotic alders, Pb shoot translocation was promoted in presence of Pb. On the other hand, Cd exclusion in symbiotic root tissues was observed with Pb and Cd. In the presence of symbiosis, only Cd and Pb showed translocation into aerial tissues when present in the nutrient solution. Moreover, the translocation of Ni to shoot was prevented by symbiosis in the presence of Cd, Ni and Pb. The hydroponic experiment demonstrated that alders benefit from the symbiosis, producing more biomass (total, root and shoot) than non nodulated alders in control condition, and in the presence of metals (Cu, Ni, Zn, Pb and Cd). Heavy metals did not reduce the nodule numbers (SNN), but the presence of Zn or Cd did reduce nodule allocation. Our study suggests that the Frankia-alder symbiosis is a promising (and a compatible) plant-microorganism association for the revegetation of contaminated sites, with minimal risk of metal dispersion. PMID:26091871

  19. CANEY CREEK WILDERNESS, ARKANSAS.

    USGS Publications Warehouse

    Ericksen, George E.; Dunn, Maynard L., Jr.

    1984-01-01

    Metallic and nonmetallic mineral resources identified in the Caney Creek Wilderness, Arkansas, include many small manganese deposits in areas of novaculite, tripoli, shale, and slate. Small amounts of hand-sorted manganese-oxide ore have been recovered from several of the manganese deposits during sporadic mining activity. Additional manganese resources remain in the known deposits, but the amount in any given deposit is small.

  20. The Influence of Speckled Alder on Nitrogen Accumulation in Adirondack Wetlands

    NASA Astrophysics Data System (ADS)

    Kiernan, B. D.; Hurd, T. M.; Raynal, D. J.

    2001-05-01

    Shrub-dominated wetlands of the Adirondacks typically support vigorous populations of nitrogen-fixing speckled alder Alnus incana (L.) Moench var. americana Regel), and are the second most abundant wetland type in the Adirondack region. In symbiotic association with an actinomycete of the genus Frankia, this shrub fixes 37-43 kg N/ha/yr in monotypic stands. This study was undertaken to quantify the abundance of alder in wetlands typed as "Scrub-shrub 1" (SS1; known as alder/willow wetlands) in the National Wetlands Inventory, and to determine the accumulation of nitrate and ammonium in alder wetland substrates. Twenty wetlands from the Oswegatchie-Black (OB) and Upper Hudson (UH) watersheds were randomly selected using the Adirondack Park Agency's GIS data base which includes wetland cover types assigned using remotely sensed data. Wetlands designated as "SS1" (scrub-shrub vegetation) and "SS1/EM1" (scrub-shrub with emergent herbaceous vegetation) were included in the sample. Six wetlands varying in alder abundance were chosen to estimate N accumulation in the substrate, with measurement of dissolved inorganic N in groundwater and ion exchange resin extracts. In the OB watershed, A. incana averaged 30 % of total shrub density in SS1 wetlands and 36 % in SS1/EM1 wetlands. Alder accounted for 49 % of all stems in UH SS1 wetlands, 28 % in the SS1/EM1 wetlands and in total accounted for 35 % of all stems in this study. Nitrate in IER extracts and groundwater was significantly higher in high-density alder wetlands (p < 0.05). Eight of the 20 wetlands included in this study were estimated to have less than 3,000 alder stems/ha, and five were estimated to have greater than 10,000 stems/ha. The other seven wetlands averaged 6,000 stems/ha. At nine sites, foliar N equaled or exceeded estimated atmospheric deposition (~10 kg/ha/yr), and was likely derived from N fixation. We conclude that 50 % of the SS1/EM1 wetlands and at least 75 % of the SS1 wetlands in these watersheds

  1. Linking Landscape Characteristics and High Stream Nitrogen in the Oregon Coast Range: Red Alder Complicates Use of Nutrient Criteria

    EPA Science Inventory

    Red alder (a nitrogen-fixing tree) and sea salt inputs can strongly influence stream nitrogen concentrations in western Oregon and Washington. We compiled a database of stream nitrogen and landscape characteristics in the Oregon Coast Range. Basal area of alder, expressed as a ...

  2. 216. Construction of the Back Creek Bridge over Back Creek ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    216. Construction of the Back Creek Bridge over Back Creek and Virginia Route 613. This is a good example of a precast concrete girder bridge. Note the fallen beam at the far end. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  3. Diels-Alder reactions: The effects of catalyst on the addition reaction

    NASA Astrophysics Data System (ADS)

    Yilmaz, Özgür; Kus, Nermin Simsek; Tunç, Tuncay; Sahin, Ertan

    2015-10-01

    The reaction between 2,3-dimethyl-1,3-butadiene and dimethyl 7-oxabicyclo[2.2.1]hepta-2,5-diene-2,3-dicarboxylate is efficiently achieved with small amounts of catalyst, i.e. phenol, AcOH, nafion, and β-cyclodextrin. Exo-diastereoselective cycloaddition reactions were observed both without catalyst and different catalysts for 48 days. As a result, different products (tricyclicmolecule 5, retro-Diels-Alder product 6, and oxidation product 7) were obtained with different catalysts. In addition, we synthesized Diels-Alders product 8 and tricyclocyclitol 10 via Diels-Alder reaction. The structures of these products were characterized by 1H NMR, 13C NMR, MS and IR spectroscopy.

  4. Electrostatic catalysis of a Diels-Alder reaction

    NASA Astrophysics Data System (ADS)

    Aragonès, Albert C.; Haworth, Naomi L.; Darwish, Nadim; Ciampi, Simone; Bloomfield, Nathaniel J.; Wallace, Gordon G.; Diez-Perez, Ismael; Coote, Michelle L.

    2016-03-01

    It is often thought that the ability to control reaction rates with an applied electrical potential gradient is unique to redox systems. However, recent theoretical studies suggest that oriented electric fields could affect the outcomes of a range of chemical reactions, regardless of whether a redox system is involved. This possibility arises because many formally covalent species can be stabilized via minor charge-separated resonance contributors. When an applied electric field is aligned in such a way as to electrostatically stabilize one of these minor forms, the degree of resonance increases, resulting in the overall stabilization of the molecule or transition state. This means that it should be possible to manipulate the kinetics and thermodynamics of non-redox processes using an external electric field, as long as the orientation of the approaching reactants with respect to the field stimulus can be controlled. Here, we provide experimental evidence that the formation of carbon-carbon bonds is accelerated by an electric field. We have designed a surface model system to probe the Diels-Alder reaction, and coupled it with a scanning tunnelling microscopy break-junction approach. This technique, performed at the single-molecule level, is perfectly suited to deliver an electric-field stimulus across approaching reactants. We find a fivefold increase in the frequency of formation of single-molecule junctions, resulting from the reaction that occurs when the electric field is present and aligned so as to favour electron flow from the dienophile to the diene. Our results are qualitatively consistent with those predicted by quantum-chemical calculations in a theoretical model of this system, and herald a new approach to chemical catalysis.

  5. The Beaver Creek story

    USGS Publications Warehouse

    Doyle, W.H., Jr.; Whitworth, B.G.; Smith, G.F.; Byl, T.D.

    1996-01-01

    Beaver Creek watershed in West Tennessee includes about 95,000 acres of the Nation's most productive farmland and most highly erodible soils. In 1989 the U.S. Geological Survey, in cooperation with the Tennessee Department of Agriculture, began a study to evaluate the effect of agricultural activities on water quality in the watershed and for best management practices designed to reduce agricultural nonpoint-source pollution. Agrichemical monitoring included testing the soils, ground water, and streams at four farm sites ranging from 27 to 420 acres. Monitoring stations were operated downstream to gain a better understanding of the water chemistry as runoff moved from small ditches into larger streams to the outlet of the Beaver Creek watershed. Prior to the implementation of best management practices at one of the farm study sites, some storms produced an average suspended-sediment concentration of 70,000 milligrams per liter. After the implementation of BMP's, however, the average value never exceeded 7,000 milligrams per liter. No-till crop production was the most effective best management practice for conserving soil on the farm fields tested. A natural bottomland hardwood wetland and a constructed wetland were evaluated as instream resource-management systems. The wetlands improved water quality downstream by acting as a filter and removing a significant amount of nonpoint-source pollution from the agricultural runoff. The constructed wetland reduced the sediment, pesticide, and nutrient load by approximately 50 percent over a 4-month period. The results of the Beaver Creek watershed study have increased the understanding of the effects of agriculture on water resources. Study results also demonstrated that BMP's do protect and improve water quality.

  6. Ecophysiological characteristics of Taiwan alder (Alnus formosana) seedlings adapted to the subtropical region.

    PubMed

    Liao, Tien-Szu; Weng, Jen-Hsien

    2002-04-01

    We investigated several ecophysiological characteristics of seedlings of a low-elevation (100-200 m) and a high-elevation (2000-2400 m) population of Taiwan alder (Alnus formosana Makino) from subtropical Taiwan. Both populations had a wide optimal temperature range for photosynthesis, and there was little difference in the optimal temperature range for photosynthesis between populations. Photosynthetic rate (P(N)) was near maximal from 20 to 35 degrees C when seedlings of both the low-elevation and the high-elevation populations were acclimated at a day/night temperature of 30/23 degrees C. When seedlings were acclimated at a day/night temperature of 20/10 degrees C, P(N) was near maximal over the range 15-35 degrees C in the low-elevation population and 15-30 degrees C in the high-elevation population. Compared with nine other tree species native to Taiwan, Taiwan alder had a high P(N) and stomatal conductance (g(s)) under well-watered conditions. Reflecting its higher transpiration rate, Taiwan alder had a significantly greater leaf-air temperature difference than camphor (Cinnamomum camphora (L.) J. Presl), a co-occurring lowland tree species with leaves similar in shape and size to those of Taiwan alder. Despite higher g(s), high root and shoot hydraulic conductances enabled Taiwan alder to maintain higher leaf water potentials than camphor under well-watered conditions. We conclude that both photosynthetic characteristics and water relations are important factors enabling Taiwan alder to adapt to a wide temperature range, thereby ensuring its success at both high and low elevations in subtropical Taiwan. PMID:11960760

  7. Stereoselection in Intramolecular Diels-Alder Reactions of 2-Cyano-1-azadienes: Indolizidine and Quinolizidine Synthesis.

    PubMed

    Tay, Gidget C; Sizemore, Nicholas; Rychnovsky, Scott D

    2016-07-01

    Progress toward understanding the scope and diastereoselectivity of intramolecular Diels-Alder reactions using 2-cyano-1-azadienes is described herein. The resulting cyanoenamine products are underutilized intermediates in organic synthesis. Assembly of the Diels-Alder precursors was achieved using an improved imine condensation/oxidative cyanation protocol. By this method, several highly substituted indolizidine and quinolizidine architectures were constructed. Quantum mechanical DFT calculations at the B3LYP/6-31+G(d) level of theory were performed for these cyclizations and provide insights into the origins of the observed diastereoselectivities. PMID:27295460

  8. Schleyer hyperconjugative aromaticity and Diels-Alder reactivity of 5-substituted cyclopentadienes.

    PubMed

    Levandowski, Brian J; Zou, Lufeng; Houk, K N

    2016-01-01

    Schleyer's discovery of hyperconjugative aromaticity and antiaromaticity in 5-substituted cyclopentadienes further expanded our understanding of the pervasive influence of aromaticity. Acceptors induce antiaromatic character by Schleyer's negative hyperconjugative aromaticity, and donors have the opposite effect. We computationally explored the Diels-Alder reactivity of 5-substituted cyclopentadienes with ethylene and maleic anhydride. The predicted billionfold difference in the computed gas phase rate constants at room temperature for the Diels-Alder reactions of 5-substituted cyclopentadienes with ethylene or maleic anhydride results from differences in the transition state distortion energies, which are directly related to the hyperconjugative aromaticity of these molecules. PMID:26444427

  9. Preparation and Diels-Alder reactions of 1′-heterosubsituted vinylimidazoles

    PubMed Central

    Ray, Abhisek; Mukherjee, Sabuj; Das, Jayanta; Bhandari, Manoj K.; Du, Hongwang; Yousufuddin, Muhammed; Lovely, Carl J.

    2015-01-01

    A Diels-Alder/rearrangement sequence has been pursued in our lab en route to a number of oroidin dimers. In order to access the fully substituted core of these molecules, 1′,2′-disubstituted 4-vinylimidazoles were required as dienes. The preparation of a series of a 4-vinylimidazoles containing substituents on the vinyl moiety via hydroalumination/electrophilic trapping or hydrosilylation are described. These derivatives undergo Diels-Alder reactions with N-phenylmaleimide to provide the tetrahydrobenzimidazole derivatives. The cycloadducts derived from halosubstituted systems generally undergo elimination, leading to the corresponding dihydrobenzimidazole, whereas the silyl and stannyl derivatives provide the corresponding 4-substituted tetrahydrobenzimidazole. PMID:26139945

  10. Enantioselective Organocatalytic Diels–Alder Trapping of Photochemically Generated Hydroxy‐o‐Quinodimethanes

    PubMed Central

    Dell'Amico, Luca; Vega‐Peñaloza, Alberto; Cuadros, Sara

    2016-01-01

    Abstract The photoenolization/Diels–Alder strategy offers straightforward access to synthetically valuable benzannulated carbocyclic products. This historical light‐triggered process has never before succumbed to efforts to develop an enantioselective catalytic approach. Herein, we demonstrate how asymmetric organocatalysis provides simple yet effective catalytic tools to intercept photochemically generated hydroxy‐o‐quinodimethanes with high stereoselectivity. We used a chiral organic catalyst, derived from natural cinchona alkaloids, to activate maleimides toward highly stereoselective Diels–Alder reactions. An unconventional mechanism of stereocontrol is operative, wherein the organocatalyst is actively involved in both the photochemical pathway, by leveraging the formation of the reactive photoenol, and the stereoselectivity‐defining event. PMID:26797768

  11. Competition between classical and hexadehydro-Diels–Alder (HDDA) reactions of HDDA triynes with furan

    PubMed Central

    Nguyen, Quang Luu; Baire, Beeraiah; Hoye, Thomas R.

    2015-01-01

    We report here thermal reactions between furan and one of three related triyne substrates. Each triyne is capable of reacting initially in two modes: (i) unimolecular hexadehydro-Diels-Alder (HDDA) reaction or (ii) bimolecular Diels-Alder reaction between one of its alkynes with furan. The relative rates of these initial events are such that two of the substrates react essentially in only one of modes (i) or (ii). The third is intermediate in behavior; its bifurcation is dependent on the concentration of the furan reactant. These results teach, more generally, principles relevant to the design of efficient HDDA-based reaction cascades. PMID:26028780

  12. Kiowa Creek Switching Station

    SciTech Connect

    Not Available

    1990-03-01

    The Western Area Power Administration (Western) proposes to construct, operate, and maintain a new Kiowa Creek Switching Station near Orchard in Morgan County, Colorado. Kiowa Creek Switching Station would consist of a fenced area of approximately 300 by 300 feet and contain various electrical equipment typical for a switching station. As part of this new construction, approximately one mile of an existing 115-kilovolt (kV) transmission line will be removed and replaced with a double circuit overhead line. The project will also include a short (one-third mile) realignment of an existing line to permit connection with the new switching station. In accordance with the Council on Environmental Quality (CEQ) regulations for implementing the procedural provisions of the National Environmental Policy Act of 1969 (NEPA), 40 CFR Parts 1500--1508, the Department of Energy (DOE) has determined that an environmental impact statement (EIS) is not required for the proposed project. This determination is based on the information contained in this environmental assessment (EA) prepared by Western. The EA identifies and evaluates the environmental and socioeconomic effects of the proposed action, and concludes that the advance impacts on the human environment resulting from the proposed project would not be significant. 8 refs., 3 figs., 1 tab.

  13. Ship Creek bioassessment investigations

    SciTech Connect

    Cushing, C.E.; Mueller, R.P.; Murphy, M.T.

    1995-06-01

    Pacific Northwest Laboratory (PNL) was asked by Elmendorf Air Force Base (EAFB) personnel to conduct a series of collections of macroinvertebrates and sediments from Ship Creek to (1) establish baseline data on these populations for reference in evaluating possible impacts from Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) activities at two operable units, (2) compare current population indices with those found by previous investigations in Ship Creek, and (3) determine baseline levels of concentrations of any contaminants in the sediments associated with the macroinvertebrates. A specific suite of indices established by the US Environmental Protection Agency (EPA) was requested for the macroinvertebrate analyses; these follow the Rapid Bioassessment Protocol developed by Plafkin et al. (1989) and will be described. Sediment sample analyses included a Microtox bioassay and chemical analysis for contaminants of concern. These analyses included, volatile organic compounds, total gasoline and diesel hydrocarbons (EPA method 8015, CA modified), total organic carbon, and an inductive-coupled plasma/mass spectrometry (ICP/MS) metals scan. Appendix A reports on the sediment analyses. The Work Plan is attached as Appendix B.

  14. Paleomagnetism and Lithostratigraphy of the Miocene Tuff of Huntoon Creek Type Section

    NASA Astrophysics Data System (ADS)

    Johnson, S.; Pluhar, C. J.; Lindeman, J. R.

    2014-12-01

    Here we define the Tuff of Huntoon Creek (THC), previously identified and mapped in Mono Basin, CA by Gilbert et al. (1968) as "latite ignimbrite" (K-Ar date of 11.1-11.9 Ma). Formally defining this formation and its paleomagnetic characteristics, can help reveal the spatial and temporal relationships of the Walker Lane and Mina Deflection structural features, including distribution of vertical axis rotation. THC is composed of four tuffs with an intercalated volcaniclastic sandstone giving a total stratigraphic thickness of ~300 m. We define THC in a gorge of Huntoon Creek, where the stratigraphic section is capped by Pliocene basalt. The lowest and most extensive stratigraphic unit, the Huntoon Valley member of THC, is ~243 m thick and can be distinguished from other units by the presence of sanidine and biotite phenocrysts and normal polarity. A 7-meter-thick volcaniclastic sandstone overlies the Huntoon Valley member, straddling a magnetic polarity reversal within the section. The 3 overlying members of THC are reversed-polarity, biotite-bearing, sanidine-free tuffs of variable degrees of welding. Their paleomagnetic directions are each statistically distinguishable from the others, indicating that the deposition of each tuff is separated by a significant amount of time and can be used as a geologically instantaneous measure of Earth's magnetic field for purposes of averaging out secular variation. The capping Pliocene olivine basalt was emplaced over an erosional unconformity of significant relief, as evidenced by the complete absence at some locations of the uppermost biotite-bearing THC member. The tilt corrected mean paleomagnetic direction for the 4 members of THC indicate a clockwise rotation magnitude of 77.5°±40.3°. The absolute rotation results of this locality are statistically indistinguishable from the relative rotation results of this locality compared to Cowtrack Mountain (Lindeman et al. 2013). The corroboration of these data suggests that

  15. Assembly of the Isoindolinone Core of Muironolide A by Asymmetric Intramolecular Diels-Alder Cycloaddition

    PubMed Central

    Flores, Beatris; Molinski, Tadeusz F.

    2011-01-01

    The hexahydro-1H-isoindolin-1-one core of muironolide A was prepared by asymmetric intramolecular Diels Alder cycloaddition using a variant of the MacMillan organocatalyst which sets the C4,C5 and C11 stereocenters. PMID:21751773

  16. WATERSHED BIOGEOCHEMISTRY IN THE OREGON COAST RANGE: THE ROLE OF RED ALDER AND SALMON

    EPA Science Inventory

    Variations in plant community composition across the landscape can influence nutrient retention and loss at the watershed scale. A striking example of plant species influence is the role of N2-fixing red alder (Alnus rubra) in the biogeochemistry of Pacific Northwest forests. T...

  17. The Phytophthora species assemblage and diversity in riparian alder ecosystems of western Oregon, USA.

    PubMed

    Sims, Laura Lee; Sutton, Wendy; Reeser, Paul; Hansen, Everett M

    2015-01-01

    Phytophthora species were systematically sampled, isolated, identified and compared for presence in streams, soil and roots of alder (Alnus species) dominated riparian ecosystems in western Oregon. We describe the species assemblage and evaluate Phytophthora diversity associated with alder. We recovered 1250 isolates of 20 Phytophthora species. Only three species were recovered from all substrates (streams, soil, alder roots): P. gonapodyides, the informally described "P. taxon Pgchlamydo", and P. siskiyouensis. P. alni ssp. uniformis along with five other species not previously recovered in Oregon forests are included in the assemblage: P.citricola s.l., P. gregata, P. gallica, P. nicotianae and P. parsiana. Phytophthora species diversity was greatest in downstream riparian locations. There was no significant difference in species diversity comparing soil and unwashed roots (the rhizosphere) to stream water. There was a difference between the predominating species from the rhizosphere compared to stream water. The most numerous species was the informally described "P. taxon Oaksoil", which was mainly recovered from, and most predominant in, stream water. The most common species from riparian forest soils and alder root systems was P. gonapodyides. PMID:26240311

  18. The role of curvature in Diels-Alder functionalization of carbon-based materials.

    PubMed

    Willocq, B; Lemaur, V; El Garah, M; Ciesielski, A; Samorì, P; Raquez, J-M; Dubois, Ph; Cornil, J

    2016-06-18

    We have estimated theoretically the impact of curvature on the free energies of activation and reaction associated with Diels-Alder reactions on carbon-based materials. Significant reduction is observed for both energy values with increasing curvature for core-functionalization, while the opposite trend prevails for edge-functionalization, as further supported by SEM/fluorescence measurements. PMID:27226252

  19. Enantioselective Synthesis of (+)-Estrone Exploiting a Hydrogen Bond-Promoted Diels−Alder Reaction

    PubMed Central

    2010-01-01

    Starting from Dane’s diene and methylcyclopentenedione, (+)-estrone is synthesized along the Quinkert−Dane route in 24% total yield. The key step is an enantioselective Diels−Alder reaction promoted by an amidinium catalyst as efficiently as by a traditional Ti-TADDOLate Lewis acid. PMID:20302330

  20. Reactions of nitroso hetero-Diels-Alder cycloadducts with azides: stereoselective formation of triazolines and aziridines.

    PubMed

    Bodnar, Brian S; Miller, Marvin J

    2007-05-11

    The addition of azides to acylnitroso hetero-Diels-Alder cycloadducts derived from cyclopentadiene affords exo-triazolines in excellent yield. The reaction is greatly affected by the level of alkene strain, while sterically demanding azides do not hinder the reaction. Conversion of the triazolines to aziridines is also described. PMID:17429998

  1. Reactions of Nitroso Hetero Diels-Alder Cycloadducts with Azides: Stereoselective Formation of Triazolines and Aziridines

    PubMed Central

    Bodnar, Brian S.

    2011-01-01

    The addition of azides to acylnitroso hetero Diels-Alder cycloadducts derived from cyclopentadiene affords exo triazolines in excellent yield. The reaction is greatly affected by reducing the level of alkene strain, while sterically demanding azides do not hinder the reaction. Conversion of the triazolines to aziridines is also described. PMID:17429998

  2. A solvent-free Diels-Alder reaction of graphite into functionalized graphene nanosheets.

    PubMed

    Seo, Jeong-Min; Baek, Jong-Beom

    2014-12-01

    A solvent-free Diels-Alder reaction was carried out by heating a mixture of graphite and a typical dienophile, maleic anhydride (MA) or maleimide (MI), in a sealed glass ampoule of argon. The functionalization of graphite with dienophiles was confirmed by various characterization techniques, suggesting the efficient functionalization and delamination of graphite into a few layers of graphitic nanosheets. PMID:25314623

  3. Hydrogen-Bonding Catalysis of Tetraalkylammonium Salts in an Aza-Diels-Alder Reaction.

    PubMed

    Kumatabara, Yusuke; Kaneko, Shiho; Nakata, Satoshi; Shirakawa, Seiji; Maruoka, Keiji

    2016-08-01

    A piperidine-derived tetraalkylammonium salt with a non-coordinating counteranion worked as an effective hydrogen-bonding catalyst in an aza-Diels-Alder reaction of imines and a Danishefsky diene. The hydrogen-bonding interaction between the ammonium salt and an imine was observed as part of a (1) H NMR titration study. PMID:27311924

  4. Synthesis of a natural chromenoquinone via the Diels-Alder reaction of pyranobenzyne and furan.

    PubMed

    Katakawa, Kazuaki; Sato, Ayaka; Iwasaki, Mari; Horikawa, Tomofumi; Kumamoto, Takuya

    2014-01-01

    We describe the total synthesis of angular chromenoquinone 1 isolated from Conospermum plants. Iodophenol, a precursor of pyranobenzyne, was prepared by Claisen rearrangement of an iodoresorcinol derivative. Diels-Alder reaction of the pyranobenzyne and a substituted furan proceeded in low regioselectivity to afford desired 1 and its regioisomer. PMID:25087635

  5. A Computational Experiment of the Endo versus Exo Preference in a Diels-Alder Reaction

    ERIC Educational Resources Information Center

    Rowley, Christopher N.; Woo, Tom K.

    2009-01-01

    We have developed and tested a computational laboratory that investigates an endo versus exo Diels-Alder cycloaddition. This laboratory employed density functional theory (DFT) calculations to study the cycloaddition of N-phenylmaleimide to furan. The endo and exo stereoisomers of the product were distinguished by building the two isomers in a…

  6. Changes in sediment volume in Alder Lake, Nisqually River Basin, Washington, 1945-2011

    USGS Publications Warehouse

    Czuba, Jonathan A.; Olsen, Theresa D.; Czuba, Christiana R.; Magirl, Christopher S.; Gish, Casey C.

    2012-01-01

    The Nisqually River drains the southwest slopes of Mount Rainier, a glaciated stratovolcano in the Cascade Range of western Washington. The Nisqually River was impounded behind Alder Dam when the dam was completed in 1945 and formed Alder Lake. This report quantifies the volume of sediment deposited by the Nisqually and Little Nisqually Rivers in their respective deltas in Alder Lake since 1945. Four digital elevation surfaces were generated from historical contour maps from 1945, 1956, and 1985, and a bathymetric survey from 2011. These surfaces were used to compute changes in sediment volume since 1945. Estimates of the volume of sediment deposited in Alder Lake between 1945 and 2011 were focused in three areas: (1) the Nisqually River delta, (2) the main body of Alder Lake, along a 40-meter wide corridor of the pre-dam Nisqually River, and (3) the Little Nisqually River delta. In each of these areas the net deposition over the 66-year period was 42,000,000 ± 4,000,000 cubic meters (m3), 2,000,000 ± 600,000 m3, and 310,000 ± 110,000 m3, respectively. These volumes correspond to annual rates of accumulation of 630,000 ± 60,000 m3/yr, 33,000 ± 9,000 m3/yr, and 4,700 ± 1,600 m3/yr, respectively. The annual sediment yield of the Nisqually (1,100 ± 100 cubic meters per year per square kilometer [(m3/yr)/km2]) and Little Nisqually River basins [70 ± 24 (m3/yr)/km2] provides insight into the yield of two basins with different land cover and geomorphic processes. These estimates suggest that a basin draining a glaciated stratovolcano yields approximately 15 times more sediment than a basin draining forested uplands in the Cascade Range. Given the cumulative net change in sediment volume in the Nisqually River delta in Alder Lake, the total capacity of Alder Lake since 1945 decreased about 3 percent by 1956, 8 percent by 1985, and 15 percent by 2011.

  7. Joint determination of 40K decay constants and 40Ar∗/ 40K for the Fish Canyon sanidine standard, and improved accuracy for 40Ar/ 39Ar geochronology

    NASA Astrophysics Data System (ADS)

    Renne, Paul R.; Mundil, Roland; Balco, Greg; Min, Kyoungwon; Ludwig, Kenneth R.

    2010-09-01

    40Ar/ 39Ar and K-Ar geochronology have long suffered from large systematic errors arising from imprecise K and Ar isotopic data for standards and imprecisely determined decay constants for the branched decay of 40K by electron capture and β - emission. This study presents a statistical optimization approach allowing constraints from 40K activity data, K-Ar isotopic data, and pairs of 238U- 206Pb and 40Ar/ 39Ar data for rigorously selected rocks to be used as inputs for estimating the partial decay constants ( λ ɛ and λ β) of 40K and the 40Ar∗/ 40K ratio ( κFCs) of the widely used Fish Canyon sanidine (FCs) standard. This yields values of κFCs = (1.6418 ± 0.0045) × 10 -3, λ ɛ = (0.5755 ± 0.0016) × 10 -10 a -1 and λ β = (4.9737 ± 0.0093) × 10 -10 a -1. These results improve uncertainties in the decay constants by a factor of >4 relative to values derived from activity data alone. Uncertainties in these variables determined by our approach are moderately to highly correlated (cov( κFCs, λ ɛ) = 7.1889 × 10 -19, cov( κFCs, λ β) = -7.1390 × 10 -19, cov( λ ɛ, λ β) = -3.4497 × 10 -26) and one must take account of the covariances in error propagation by either linear or Monte Carlo methods. 40Ar/ 39Ar age errors estimated from these results are significantly reduced relative to previous calibrations. Also, age errors are smaller for a comparable level of isotopic measurement precision than those produced by the 238U/ 206Pb system, because the 40Ar/ 39Ar system is now jointly calibrated by both the 40K and 238U decay constants, and because λ ɛ( 40K) < λ( 238U). Based on this new calibration, the age of the widely used Fish Canyon sanidine standard is 28.305 ± 0.036 Ma. The increased accuracy of 40Ar/ 39Ar ages is now adequate to provide meaningful validation of high-precision U/Pb or astronomical tuning ages in cases where closed system behavior of K and Ar can be established.

  8. 5. VIEW OF MOSIER CREEK BRIDGE, NORTH ELEVATION. Historic ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. VIEW OF MOSIER CREEK BRIDGE, NORTH ELEVATION. - Historic Columbia River Highway, Mosier Creek Bridge, Spanning Mosier Creek carrying Historic Columbia River Highway, Troutdale, Multnomah County, OR

  9. EAGLE CREEK BRIDGE, WEST ELEVATION LOOKING 55 DEGREES NORTHEAST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    EAGLE CREEK BRIDGE, WEST ELEVATION LOOKING 55 DEGREES NORTHEAST - Historic Columbia River Highway, Eagle Creek Bridge, Spanning Eagle Creek on Historic Columbia River Highway, Troutdale, Multnomah County, OR

  10. 2. MOSIER CREEK BRIDGE LOOKING NORTHWEST AT SOUTH ELEVATION. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. MOSIER CREEK BRIDGE LOOKING NORTHWEST AT SOUTH ELEVATION. - Historic Columbia River Highway, Mosier Creek Bridge, Spanning Mosier Creek carrying Historic Columbia River Highway, Troutdale, Multnomah County, OR

  11. 2. EAGLE CREEK RECREATION AREA, VIEW OF COMMUNITY KITCHEN. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. EAGLE CREEK RECREATION AREA, VIEW OF COMMUNITY KITCHEN. - Historic Columbia River Highway, Eagle Creek Recreation Area, Historic Columbia River Highway at Eagle Creek, Troutdale, Multnomah County, OR

  12. Perspective view of span over French Creek and east abutment, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Perspective view of span over French Creek and east abutment, looking NW. - Pennsylvania Railroad, French Creek Trestle, Spanning French Creek, north of Paradise Street, Phoenixville, Chester County, PA

  13. Underside of span over Pickering Creek, showing highly skewed piers, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Underside of span over Pickering Creek, showing highly skewed piers, looking south. - Pennsylvania Railroad, Pickering Creek Trestle, Spanning Pickering Creek, south of Buckwalter Road, Pickering, Chester County, PA

  14. Dendrochronology and lakes: using tree-rings of alder to reconstruct lake levels

    NASA Astrophysics Data System (ADS)

    van der Maaten, Ernst; Buras, Allan; Scharnweber, Tobias; Simard, Sonia; Kaiser, Knut; Lorenz, Sebastian; van der Maaten-Theunissen, Marieke; Wilmking, Martin

    2014-05-01

    Climate change is considered a major threat for ecosystems around the world. Assessing its effects is challenging, amongst others, as we are unsure how ecosystems may respond to climate conditions they were not exposed to before. However, increased insight may be obtained by analyzing responses of ecosystems to past climate variability. In this respect, lake ecosystems appear as valuable sentinels, because they provide direct and indirect indicators of change through effects of climate. Lake-level fluctuations of closed catchments, for example, reflect a dynamic water balance, provide detailed insight in past moisture variations, and thereby allow for assessments of effects of anticipated climate change. Up to now, lake-level data are mostly obtained from gauging records and reconstructions from sediments and landforms. However, these records are in many cases only available over relatively short time periods, and, since geoscientific work is highly demanding, lake-level reconstructions are lacking for many regions. Here, we present and discuss an alternative method to reconstruct lake levels, which is based on tree-ring data of black alder (Alnus glutinosa L.). This tree species tolerates permanently waterlogged and temporally flooded conditions (i.e. riparian vegetation), and is often found along lakeshores. As the yearly growth of trees varies depending upon the experienced environmental conditions, annual rings of black alder from lakeshore vegetation likely capture information on variations in water table, and may therefore be used to reconstruct lake levels. Although alder is a relatively short-lived tree species, the frequent use of its' decay-resistant wood in foundations of historical buildings offers the possibility of extending living tree-chronologies back in time for several centuries. In this study, the potential to reconstruct lake-level fluctuations from tree-ring chronologies of black alder is explored for three lake ecosystems in the Mecklenburg

  15. Big Bayou Creek and Little Bayou Creek Watershed Monitoring Program

    SciTech Connect

    Kszos, L.A.; Peterson, M.J.; Ryon; Smith, J.G.

    1999-03-01

    Biological monitoring of Little Bayou and Big Bayou creeks, which border the Paducah Site, has been conducted since 1987. Biological monitoring was conducted by University of Kentucky from 1987 to 1991 and by staff of the Environmental Sciences Division (ESD) at Oak Ridge National Laboratory (ORNL) from 1991 through March 1999. In March 1998, renewed Kentucky Pollutant Discharge Elimination System (KPDES) permits were issued to the US Department of Energy (DOE) and US Enrichment Corporation. The renewed DOE permit requires that a watershed monitoring program be developed for the Paducah Site within 90 days of the effective date of the renewed permit. This plan outlines the sampling and analysis that will be conducted for the watershed monitoring program. The objectives of the watershed monitoring are to (1) determine whether discharges from the Paducah Site and the Solid Waste Management Units (SWMUs) associated with the Paducah Site are adversely affecting instream fauna, (2) assess the ecological health of Little Bayou and Big Bayou creeks, (3) assess the degree to which abatement actions ecologically benefit Big Bayou Creek and Little Bayou Creek, (4) provide guidance for remediation, (5) provide an evaluation of changes in potential human health concerns, and (6) provide data which could be used to assess the impact of inadvertent spills or fish kill. According to the cleanup will result in these watersheds [Big Bayou and Little Bayou creeks] achieving compliance with the applicable water quality criteria.

  16. δ15N patterns of Douglas-fir and red alder riparian forests in the Oregon Coast Range

    USGS Publications Warehouse

    Scott, E.E.; Perakis, S.S.; Hibbs, D.E.

    2008-01-01

    We used naturally occurring stable isotopes of N to compare N dynamics in near-stream and upslope environments along riparian catenas in N-fixing red alder (Alnus rubra) and Douglas-fir (Pseudotsuga menziesii) forests in the Coast Range of western Oregon. Based on the existing literature, we expected soil δ15N to be enriched closer to streams owing to inputs of isotopically heavy, marine-derived N by spawning salmon, higher rates of denitrification near the stream, or both. However, it has been unclear what effect red alder might have on soil δ15N patterns near streams. We found a consistent −1‰ δ15N signature in red alder foliage, and δ15N of total N in soils under red alder averaged 2.2‰ along sampling transects extending 20 m upslope from the stream. Surprisingly, δ15N of total N in soil under Douglas-fir was progressively depleted nearer to streams, opposite from the pattern expected from N losses by denitrification or N inputs from anadromous salmon. Instead, δ15N of total N in soil under Douglas-fir converged toward soil δ15N values typical of red alder sites. We consider that the historic presence of red alder may have contributed a legacy of lower soil δ15N nearer to streams on sites that are currently dominated by young Douglas-fir forest.

  17. Headwater riparian invertebrate communities associated with red alder and conifer wood and leaf litter in southeastern Alaska

    USGS Publications Warehouse

    LeSage, C.M.; Merritt, R.W.; Wipfli, M.S.

    2005-01-01

    We examined how management of young upland forests in southeastern Alaska affect riparian invertebrate taxa richness, density, and biomass, in turn, potentially influencing food abundance for fish and wildlife. Southeastern Alaska forests are dominated by coniferous trees including Sitka spruce (Picea sitchensis (Bong.) Carr.), western hemlock (Tsuga heterophylla (Raf.) Sarg.), with mixed stands of red cedar (Thuja plicata Donn.). Red alder (Alnus rubra Bong.) is hypothesized to influence the productivity of young-growth conifer forests and through forest management may provide increased riparian invertebrate abundance. To compare and contrast invertebrate densities between coniferous and alder riparian habitats, leaf litter and wood debris (early and late decay classes) samples were collected along eleven headwater streams on Prince of Wales Island, Alaska, during the summers of 2000 and 2001. Members of Acarina and Collembola were the most abundant taxa collected in leaf litter with alder litter having significantly higher mean taxa richness than conifer litter. Members of Acarina were the most abundant group collected on wood debris and alder wood had significantly higher mean taxa richness and biomass than conifer wood. Alder wood debris in more advanced decay stages had the highest mean taxa richness and biomass, compared to other wood types, while conifer late decay wood debris had the highest densities of invertebrates. The inclusion of alder in young-growth conifer forests can benefit forest ecosystems by enhancing taxa richness and biomass of riparian forest invertebrates. ?? 2005 by the Northwest Scientific Association. All rights reserved.

  18. 5. EAGLE CREEK RECREATION AREA, EXTERIOR VIEW OF PORTION OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. EAGLE CREEK RECREATION AREA, EXTERIOR VIEW OF PORTION OF EAGLE CREEK OVERLOOK. - Historic Columbia River Highway, Eagle Creek Recreation Area, Historic Columbia River Highway at Eagle Creek, Troutdale, Multnomah County, OR

  19. 6. EAGLE CREEK RECREATION AREA, INTERIOR VIEW OF PORTION OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. EAGLE CREEK RECREATION AREA, INTERIOR VIEW OF PORTION OF EAGLE CREEK OVERLOOK. - Historic Columbia River Highway, Eagle Creek Recreation Area, Historic Columbia River Highway at Eagle Creek, Troutdale, Multnomah County, OR

  20. Distortion-Controlled Reactivity and Molecular Dynamics of Dehydro-Diels-Alder Reactions.

    PubMed

    Yu, Peiyuan; Yang, Zhongyue; Liang, Yong; Hong, Xin; Li, Yanwei; Houk, K N

    2016-07-01

    We report density functional theory (M06-2X) studies of a series of dehydro-Diels-Alder (DDA) reactions. For these and the parent reaction, the stepwise mechanisms have similar barriers, whereas the barriers of the concerted mechanisms differ significantly. The reactivity of DDA reactions is controlled by distortion energy. The concerted and stepwise mechanisms of the hexadehydro-Diels-Alder (HDDA) reaction are competitive with activation barriers of ∼36 kcal/mol. This is because a large distortion energy (∼43 kcal/mol) is required to achieve the concerted transition state geometry. MD simulations reveal that productive concerted trajectories display a strong angle bending oscillation (∼25° oscillation amplitude), while the stepwise trajectories show only a chaotic pattern and less pronounced bending vibrations. PMID:27286801

  1. Use of wetlands for production of woody plants for fuels and petrochemical substitutes. [Alders, willows, poplars

    SciTech Connect

    Farnham, R.S.; Read, P.

    1981-03-01

    Work performed on this project in the past year has included the evaluations of natural stands productivity for wetland biomass species; propagation studies with alder, willow and poplar species; nursery establishment for production of cultivars and evaluation of wetland soils suitable for production of woody biomass species. Also a biomass research facility has been established in N. Minnesota suitable for long-term research and demonstration. Propagation research has included both micro and macro propagation techniques with native willows, selected willow clones from Sweden, alder seed selection from Finland and hybrid poplar clones from US Forest Service, Rhinelander, Wisconsin. Approximately 100,000 rooted plants will be available for field research by June 1, 1981.

  2. Cyclodextrin-promoted Diels Alder reactions of a polycyclic aromatic hydrocarbon under mild reaction conditions

    PubMed Central

    Chaudhuri, Sauradip; Phelan, Tyler; Levine, Mindy

    2015-01-01

    Reported herein is the effect of cyclodextrins on the rates of aqueous Diels Alder reactions of 9-anthracenemethanol with a variety of N-substituted maleimides. These reactions occurred under mild reaction conditions (aqueous solvent, 40 °C), and were most efficient for the reaction of N-cyclohexylmaleimide with a methyl-β-cyclodextrin additive (94% conversion in 24 hours). These results can be explained on the basis of a model wherein the cyclodextrins bind the hydrophobic substituents on the maleimides and activate the dienophile via electronic modulation of the maleimide double bond. The results reported herein represent a new mechanism for cyclodextrin-promoted Diels Alder reactions, and have significant potential applications in the development of other cyclodextrin-promoted organic transformations. Moreover, the ability to deplanarize polycyclic aromatic hydrocarbons (PAHs) under mild conditions, as demonstrated herein, has significant applications for PAH detoxification. PMID:26692588

  3. Total synthesis of Elisabethin A: intramolecular Diels-Alder reaction under biomimetic conditions.

    PubMed

    Heckrodt, Thilo J; Mulzer, Johann

    2003-04-23

    We describe the first total synthesis of the marine diterpenoid elisabethin A. The synthesis uses (S)-hydroxy-2-methyl-propionate as the chiral starting material, which is elaborated into a dienyl-iodide and added to an aryl acetic acid ester via enolate alkylation. The hydroquinoid system is oxidized to the quinone which serves as the dienophile in a highly stereocontrolled intramolecular Diels-Alder addition. This IMDA reaction, which to our knowledge is the first one to employ a terminal (Z)-diene, proceeds under biomimetic conditions (water, ferrichloride as the oxidant, room temperature) with high yield and stereoselectivity. The Diels-Alder adduct is transformed into the natural product via a three-step sequence including selective hydrogenation, base-catalyzed epimerization of the cis- into the trans-decalin system and O-demethylation. PMID:12696865

  4. Recrystallization and anatexis along the plutonic-volcanic contact of the Turkey Creek caldera, Arizona

    USGS Publications Warehouse

    du Bray, E.A.; Pallister, J.S.

    1999-01-01

    Unusual geologic and geochemical relations are preserved along the contact between intracaldera tuff and a resurgent intrusion within the 26.9 Ma Turkey Creek caldera of southeast Arizona. Thick intracaldera tuff is weakly argillically altered throughout, except in zones within several hundred meters of its contact with the resurgent intrusion, where the groundmass of the tuff has been variably converted to granophyre and unaltered sanidine phenocrysts are present. Dikes of similarly granophyric material originate at the tuff-resurgent intrusion contact and intrude overlying intracaldera megabreccia and tuff. Field relations indicate that the resurgent intrusion is a laccolith and that it caused local partial melting of adjacent intracaldera tuff. Geochemical and petrographic relations indicate that small volumes of partially melted intracaldera tuff assimilated and mixed with dacite of the resurgent intrusion along their contact, resulting in rocks that have petrographic and compositional characteristics transitional between those of tuff and dacite. Some of this variably contaminated, second-generation magma coalesced, was mobilized, and was intruded into overlying intracaldera rocks. Interpretation of the resurgent intrusion in the Turkey Creek and other calderas as intracaldera laccoliths suggests that intrusions of this type may be a common, but often unrecognized, feature of calderas. Development of granophyric and anatectic features such as those described here may be equally common in other calderas. The observations and previously undocumented processes described here can be applied to identification and interpretation of similarly enigmatic relations and rocks in other caldera systems. Integration of large-scale field mapping with detailed petrographic and chemical data has resulted in an understanding of otherwise intractable but petrologically important caldera-related features.

  5. Biomass of Speckled Alder on an Air-Polluted Mountain Site and its Response to Fertilization

    NASA Astrophysics Data System (ADS)

    Kuneš, Ivan; Baláš, Martin; Koňasová, Tereza; Špulák, Ondřej; Balcar, Vratislav; Millerová, Kateřina Bednářová; Kacálek, Dušan; Jakl, Michal; Zahradník, Daniel; Vítámvás, Jan; Š´astná, Jaroslava; Jaklová Dytrtová, Jana

    2014-12-01

    The article summarizes outcomes of a biomass study conducted in a young speckled alder plantation on a cold mountain site. At this location, the previously existing old forest was clear felled because of damage from air pollution, and present-day surface humus is in need of restoration. The intention of this study was to quantify the biomass and nutrients accumulated by alders and their components and assess whether the initial fertilization resulted in increased biomass production and nutrient accumulation in the biomass. Besides the control, two fertilized treatments were installed. In the surface treatment (SUT), the amendment was applied as a base dressing in small circles around trees. In the planting-hole treatment (PHT), the amendment was incorporated into soil inside the planting holes. Five growth seasons after planting and fertilization, six alders from each treatment were harvested including roots. Their biomass was quantified and analyzed for macroelements. The greatest pool of dry mass (DM) was branches in the control and stem wood in the fertilized treatments. The greatest pools of macroelements were leaves and branches. The most pronounced effects of fertilization were recorded in the DM and consequently in the absolute quantities of nutrients. The DM of an average tree in the control, SUT, and PHT was 85, 226, and 231 g, respectively. The absolute contents of nutrients per tree in the fertilized treatments showed the following increases, as compared with the control: (N) 2.5-2.6 times; (P) 1.6-2.4 times; (K) 1.8-2.1 times; and (Mg) 1.8-2.0 times, respectively. Speckled alder responded positively to fertilization.

  6. Biomass of speckled alder on an air-polluted mountain site and its response to fertilization.

    PubMed

    Kuneš, Ivan; Baláš, Martin; Koňasová, Tereza; Spulák, Ondřej; Balcar, Vratislav; Millerová, Kateřina Bednářová; Kacálek, Dušan; Jakl, Michal; Zahradník, Daniel; Vítámvás, Jan; Stastná, Jaroslava; Jaklová Dytrtová, Jana

    2014-12-01

    The article summarizes outcomes of a biomass study conducted in a young speckled alder plantation on a cold mountain site. At this location, the previously existing old forest was clear felled because of damage from air pollution, and present-day surface humus is in need of restoration. The intention of this study was to quantify the biomass and nutrients accumulated by alders and their components and assess whether the initial fertilization resulted in increased biomass production and nutrient accumulation in the biomass. Besides the control, two fertilized treatments were installed. In the surface treatment (SUT), the amendment was applied as a base dressing in small circles around trees. In the planting-hole treatment (PHT), the amendment was incorporated into soil inside the planting holes. Five growth seasons after planting and fertilization, six alders from each treatment were harvested including roots. Their biomass was quantified and analyzed for macroelements. The greatest pool of dry mass (DM) was branches in the control and stem wood in the fertilized treatments. The greatest pools of macroelements were leaves and branches. The most pronounced effects of fertilization were recorded in the DM and consequently in the absolute quantities of nutrients. The DM of an average tree in the control, SUT, and PHT was 85, 226, and 231 g, respectively. The absolute contents of nutrients per tree in the fertilized treatments showed the following increases, as compared with the control: (N) 2.5-2.6 times; (P) 1.6-2.4 times; (K) 1.8-2.1 times; and (Mg) 1.8-2.0 times, respectively. Speckled alder responded positively to fertilization. PMID:25294419

  7. TEMPO-Mediated Aza-Diels-Alder Reaction: Synthesis of Tetrahydropyridazines Using Ketohydrazones and Olefins.

    PubMed

    Yang, Xiu-Long; Peng, Xie-Xue; Chen, Fei; Han, Bing

    2016-05-01

    A novel, facile, and efficient method for the synthesis of tetrahydropyridazines by a one-pot tandem reaction of easily accessible ketohydrazones and olefins in the presence of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) has been successfully developed. The reaction involves the initial generation of azoalkenes from direct oxidative dehydrogenation of ketohydrazones using TEMPO as the commercially available oxidant, followed by a subsequent aza-Diels-Alder reaction with olefins. PMID:27120574

  8. Diels-Alder Reactions of Furans with Itaconic Anhydride: Overcoming Unfavorable Thermodynamics.

    PubMed

    Pehere, Ashok D; Xu, Shu; Thompson, Severin K; Hillmyer, Marc A; Hoye, Thomas R

    2016-06-01

    Unfavorable thermodynamics often render furans reluctant to engage in high-yielding Diels-Alder (DA) cycloaddition reactions. Here, we report the highly efficient conversion of the biosourced reactants itaconic anhydride (IA) and furfuryl alcohol (FA) to a single DA adduct. The free energy advantages provided by anhydride ring opening and crystal lattice energy of the product overcome the loss of aromaticity of the furanoid diene. Detailed (1)H NMR studies provided valuable insights about relevant kinetic and thermodynamic features. PMID:27214494

  9. New L-Serine Derivative Ligands as Cocatalysts for Diels-Alder Reaction

    PubMed Central

    Sousa, Carlos A. D.; Rodríguez-Borges, José E.; Freire, Cristina

    2013-01-01

    New L-serine derivative ligands were prepared and tested as cocatalyst in the Diels-Alder reactions between cyclopentadiene (CPD) and methyl acrylate, in the presence of several Lewis acids. The catalytic potential of the in situ formed complexes was evaluated based on the reaction yield. Bidentate serine ligands showed good ability to coordinate medium strength Lewis acids, thus boosting their catalytic activity. The synthesis of the L-serine ligands proved to be highly efficient and straightforward. PMID:24383009

  10. Molecular Complexity via C–H Activation: A Dehydrogenative Diels-Alder Reaction

    PubMed Central

    Stang, Erik M.; White, M. Christina

    2011-01-01

    Traditionally, C–H oxidation reactions install oxidized functionality onto a preformed molecular skeleton, resulting in a local molecular change. The use of C–H activation chemistry to construct complex molecular scaffolds is a new area with tremendous potential in synthesis. We report a Pd(II)/bis-sulfoxide catalyzed dehydrogenative Diels-Alder reaction that converts simple terminal olefins into complex cycloadducts in a single operation. PMID:21842902

  11. Water quality study at the Congaree Swamp National monument of Myers Creek, Reeves Creek and Toms Creek. Technical report

    SciTech Connect

    Rikard, M.

    1991-11-01

    The Congaree Swamp National Monument is one of the last significant near virgin tracts of bottom land hardwood forests in the Southeast United States. The study documents a water quality monitoring program on Myers Creek, Reeves Creek and Toms Creek. Basic water quality parameters were analyzed. High levels of aluminum and iron were found, and recommendations were made for further monitoring.

  12. 77 FR 42714 - Eagle Creek Hydropower, LLC, Eagle Creek Land Resources, LLC, Eagle Creek Water Resources, LLC...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-20

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Eagle Creek Hydropower, LLC, Eagle Creek Land Resources, LLC, Eagle Creek Water Resources, LLC; Notice of Application Accepted for Filing, Soliciting Motions To Intervene, Protests, and Comments Take notice that...

  13. Multiple Magmatic Events Over 40 Ma in the Fish Creek Mountains, North-central Great Basin, Nevada, USA

    NASA Astrophysics Data System (ADS)

    Cousens, B.; Henry, C. D.; Stevens, C.; Varve, S.

    2011-12-01

    The Fish Creek Mountains, located in north-central Nevada south of Battle Mountain, is a site of multiple igneous events ranging from ca. 35 Ma to 1 Ma, covering most of the igneous history of the Great Basin of the western United States. Such extended volcanic activity allows for documentation of mantle sources and petrogenetic processes over time. Beginning approximately 50 Ma, the Great Basin experienced a magmatic front that began migrating southwestward across southern Idaho, central Oregon and into northern Nevada and Utah. Intermediate, "arc-like" andesite and dacite dominated volcanic activity in northeastern Nevada between about 45 and 36 Ma. By 34 Ma, a northwest-trending belt of rhyolitic ash-flow calderas began to develop through central Nevada, the "ignimbrite flare-up". Volcanism then migrated westwards towards the Sierra Nevada. In north-central Nevada, the oldest lavas are ca. 35 Ma basaltic andesites through rhyolites that are exposed in the western Shoshone Range, the eastern Tobin Range, and the northern and eastern Fish Creek Mountains. Plagioclase-rich andesites, dacite intrusions, and volcanic breccias occur in a belt along the western side of the Fish Creek Mountains. The bulk of the Fish Creek Mountains is composed of the 24.7 Ma Fish Creek Mountains rhyolitic tuff that is largely confined to an undeformed caldera structure. The caldera and tuff are anomalously young compared to nearby felsic centers such as the Caetano caldera (33.8Ma) and Shoshone Range (39-35 Ma) and relative to the southwest to west magmatic migration. The basal tuff is unwelded, with abundant pumice and lithic (primarily volcanic) fragments but only rare crystals. Sanidine and smoky quartz phenocrysts become more abundant upsection and glassy fiamme (hydrated to devitrified) are common, but the abundance of lithic fragments diminishes. 16-15 Ma volcanic rocks of the Northern Nevada Rift are exposed in the Battle Mountain area, ranging in composition from subalkaine

  14. The mechanisms and timescales of rhyolite generation at Yellowstone caldera: New insights from 238U-230Th crystallization ages, trace-elements, and isotope compositions of zircon and sanidine

    NASA Astrophysics Data System (ADS)

    Stelten, M. E.; Cooper, K. M.; Vazquez, J. A.; Calvert, A. T.

    2013-12-01

    The Yellowstone Plateau hosts one of the largest Quaternary magmatic systems on Earth, with caldera forming eruptions at ~2.1 Ma, ~1.3 Ma, and ~0.64 Ma, as well as numerous intracaldera rhyolitic eruptions between caldera-forming events. The most recent post-caldera eruptive episode at Yellowstone produced the Central Plateau Member (CPM) of the Plateau Rhyolite, which erupted intermittently between ca. 170-70 ka with a cumulative volume ≥600 km3. Thus, the CPM rhyolites provide snapshots of a large silicic magmatic system though time. We examine five CPM rhyolites that erupted from ~125 ka to ~70 ka, and constrain the mechanisms and timescales of generating eruptible rhyolites at Yellowstone caldera by comparing (1) 238U-230Th crystallization ages and trace-element compositions of the interiors and surfaces (i.e., unpolished rims) of individual zircons with (2) bulk 238U-230Th crystallization ages and in situ major-element, Ba, and Pb isotope data for sanidines hosted in each rhyolite. The zircon age and trace-element data show that zircons in CPM rhyolites record crystallization from their respective eruption age to >150 ka before eruption, with most zircon surfaces crystallizing close to eruption and many interiors crystallizing 10 kyr to 150 kyr before eruption. At any given age, zircon surfaces have homogeneous trace-element compositions relative to zircon interiors for most elements and element ratios. For example, when considering data from all five CPM rhyolites, the zircon surfaces and interiors show similar broad trends in Eu/Eu* and U/Th over time, but the surfaces display less scatter. These observations suggest that the zircon surfaces grew from a more homogeneous region of the magma reservoir relative to where the zircon interiors grew. Although the zircon surfaces and interiors are similar in some elements and element ratios (e.g., Eu/Eu*, U/Th) at a given age, zircon surfaces and interiors display distinct (Y, MREE, HREE)/(P, U) ratios at a given

  15. PECONIC ESTUARY PROGRAM TIDAL CREEK STUDY

    EPA Science Inventory

    EEA evaluated ten tidal creeks throughout the Peconic Estuary representing a wide range of watershed variables. Primary focus was directed towards the collection and analysis of the macrobenthic invertebrate communities of these ten tidal creeks. Analysis of the macrobenthic comm...

  16. 78 FR 62616 - Salmon Creek Hydroelectric Company, Salmon Creek Hydroelectric Company, LLC; Notice of Transfer...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-22

    ... Energy Regulatory Commission Salmon Creek Hydroelectric Company, Salmon Creek Hydroelectric Company, LLC; Notice of Transfer of Exemption 1. By letter filed September 23, 2013, Salmon Creek Hydroelectric Company informed the Commission that they have changed its name to Salmon Creek Hydroelectric Company, LLC for...

  17. Asotin Creek Model Watershed Plan

    SciTech Connect

    Browne, D.; Holzmiller, J.; Koch, F.; Polumsky, S.; Schlee, D.; Thiessen, G.; Johnson, C.

    1995-04-01

    The Asotin Creek Model Watershed Plan is the first to be developed in Washington State which is specifically concerned with habitat protection and restoration for salmon and trout. The plan is consistent with the habitat element of the ``Strategy for Salmon``. Asotin Creek is similar in many ways to other salmon-bearing streams in the Snake River system. Its watershed has been significantly impacted by human activities and catastrophic natural events, such as floods and droughts. It supports only remnant salmon and trout populations compared to earlier years. It will require protection and restoration of its fish habitat and riparian corridor in order to increase its salmonid productivity. The watershed coordinator for the Asotin County Conservation District led a locally based process that combined local concerns and knowledge with technology from several agencies to produce the Asotin Creek Model Watershed Plan.

  18. High-precision 40Ar/39Ar sanidine geochronology of ignimbrites in the Mogollon-Datil volcanic field, southwestern New Mexico

    USGS Publications Warehouse

    McIntosh, W.C.; Sutter, J.F.; Chapin, C.E.; Kedzie, L.L.

    1990-01-01

    40Ar/39Ar age spectra have been obtained from 85 sanidine separates from 36 ignimbrites and one rhyolitic lava in the latest Eocene-Oligocene Mogollon-Datil volcanic field of southwestern New Mexico. Of the 97 measured age spectra, 94 yield weighted-mean plateau ages each giving single-spectrum 1?? precision of??0.25%-0.4% (??0.07-0.14 Ma). Replicate plateau age determinations for eight different samples show within-sample 1?? precisions averaging ??0.25%. Plateau ages from multiple (n=3-8) samples of individual ignimbrites show 1?? within-unit precision of ??0.1%-0.4% (??0.04-0.13 Ma). This within-unit precision represents a several-fold improvement over published K-Ar data for the same ignimbrites, and is similar to the range of precisions reported from single-crystal laser fusion studies. A further indication of the high precision of unit-mean 40Ar/30Ar ages is their close agreement with independently established stratigraphic order. Two samples failed to meet plateau criteria, apparently due to geologic contamination by older feldspars. Effects of minor contamination are shown by six other samples, which yielded slightly anomalous plateau ages. 40Ar/39Ar plateau ages permit resolution of units differing in age by 0.5% (0.15 Ma) or less. This high resolution, combined with paleomagnetic studies, has helped to correlate ignimbrites among isolated ranges and has allowed development of an integrated timestratigraphic framework for the volcanic field. Mogollon-Datil ignimbrites range in age from 36.2 to 24.3 Ma. Ignimbrite activity was strongly episodic, being confined to four brief (<2.6 m.y.) eruptive episodes separated by 1-3 m.y. gaps. Ignimbrite activity generally tended to migrate from the southeast toward the north and west. ?? 1990 Springer-Verlag.

  19. High-precision 40Ar/39Ar sanidine geochronology of ignimbrites in the Mogollon-Datil volcanic field, southwestern New Mexico

    NASA Astrophysics Data System (ADS)

    McIntosh, William C.; Sutter, John F.; Chapin, Charles E.; Kedzie, Laura L.

    1990-11-01

    40Ar/39Ar age spectra have been obtained from 85 sanidine separates from 36 ignimbrites and one rhyolitic lava in the latest Eocene-Oligocene Mogollon-Datil volcanic field of southwestern New Mexico. Of the 97 measured age spectra, 94 yield weighted-mean plateau ages each giving single-spectrum 1σ precision of±0.25% 0.4% (±0.07 0.14 Ma). Replicate plateau age determinations for eight different samples show within-sample 1σ precisions averaging ±0.25%. Plateau ages from multiple ( n=3 8) samples of individual ignimbrites show 1σ within-unit precision of ±0.1% 0.4% (±0.04 0.13 Ma). This within-unit precision represents a several-fold improvement over published K-Ar data for the same ignimbrites, and is similar to the range of precisions reported from single-crystal laser fusion studies. A further indication of the high precision of unit-mean 40Ar/30Ar ages is their close agreement with independently established stratigraphic order. Two samples failed to meet plateau criteria, apparently due to geologic contamination by older feldspars. Effects of minor contamination are shown by six other samples, which yielded slightly anomalous plateau ages. 40Ar/39Ar plateau ages permit resolution of units differing in age by 0.5% (0.15 Ma) or less. This high resolution, combined with paleomagnetic studies, has helped to correlate ignimbrites among isolated ranges and has allowed development of an integrated timestratigraphic framework for the volcanic field. Mogollon-Datil ignimbrites range in age from 36.2 to 24.3 Ma. Ignimbrite activity was strongly episodic, being confined to four brief (<2.6 m.y.) eruptive episodes separated by 1 3 m.y. gaps. Ignimbrite activity generally tended to migrate from the southeast toward the north and west.

  20. Stable Isotope Variability of Altered Sanidine Feldspars within the Bear Lodge Alkaline Intrusive Complex, Wyoming: Implications for Mineral Exploration Near a Late-Stage Carbonatite Ore Body

    NASA Astrophysics Data System (ADS)

    Mulvaney-Norris, J. L.; Larson, P. B.

    2015-12-01

    In a brecciated intrusive complex, mineral assemblages from non-ore-stage hydrothermal alteration may be mistakenly associated with ore body emplacement during exploration. The ability to differentiate mineralizing from non-mineralizing alteration by stable isotope analysis, and to map the fluid pathways, is a useful tool for future exploration. The Bull Hill diatreme, central Bear Lodge Mountains, contains porphyritic alkaline clasts and cross-cutting megacrystic sanidine trachyte dikes. The K feldspar (Kfs) phenocrysts reacted with and recorded the passage of hydrothermal fluids, likely derived from post-diatreme carbonatite intrusions. A study of the δ18O values of Kfs in the complex can assist mineralization mapping by revealing the late hydrothermal fluid pathways and provenance. Dike and breccia samples were split from three drill holes at regular distances, moving away from carbonatite dikes and large veins. Eighteen samples were prepared for oxygen isotope analysis by physical separation of megacrysts, or by crushing and hand-picking Kfs fragments from the breccia. A carbonatite Kfs sample was prepared by partial HCl digestion. Oxygen isotope ratios were measured at the Washington State University GeoAnalytical Laboratory using a Finnegan Delta S Mass Spectrometer. Kfs δ18O values range between 7.69‰ and 9.09‰ in the diatreme breccia xenocrysts, 5.28‰ to 8.12‰ in the megacrystic dike phenocrysts, and 7.15‰ in the carbonatite phenocrysts. Results suggest no clear relationship between the δ18O values in Kfs and the different phases of intrusion. This may be due to δ18O variability introduced by zoned and multi-crystal samples, limited variations of δ18O values among intrusion fluids, or that the final carbonatite intrusion pervasively altered all samples within the study area. Therefore, this method may not be particularly useful for identifying potential ore-bearing units in the Bear Lodge Intrusive Complex.

  1. Can an Alder Disease Influence the Controls of Ecosystem Water Flux?

    NASA Astrophysics Data System (ADS)

    Rohrs-Richey, J. K.; Mulder, C. P.; Ruess, R. W.; Winton, L. M.; Stanosz, G. R.

    2007-12-01

    In Alaska, nitrogen-fixing shrubs (Alnus spp.) comprise a large component of the vegetation and are important for water and energy flux in the Alaskan tundra, the Interior boreal forest, and south-central Alaska. Recently there has been high incidence and severity of a canker disease on Alnus which alters small scale controls (e.g., leaves, branches) of water and carbon flux and may have ecosystem scale effects in severely diseased areas. The fungal pathogen, Valsa melanodiscus (anamorph =Cytospora umbrina), kills active xylem and phloem, causes long, girdling cankers on stems, and is frequently associated with stem mortality in the thin leaf alder (Alnus tenuifolia) and green alder (Alnus crispa). We are just beginning to understand how this canker disease affects the physiology of its host and the implications for water loss and carbon fixation. An inoculation experiment at the University of Alaska is currently being conducted on well-watered and water-limited green alders to: 1) monitor the response of the water transport system to infection and canker development; 2) assess the ability of colonized alders to adjust water use efficiency; and 3) measure the effect of canker development on photosynthesis. Only 4 weeks after inoculation, stems (3-5 mm diam.) with incipient cankers had an overall reduction in total daily water loss and up to 50 percent decrease in daily peak water loss. Stems with incipient cankers were also unable to attain the maximum photosynthetic rate of healthy stems, and had lower light saturation points and quantum efficiencies. Further quantification of these relationships is underway. This study, in combination with recent field measurements of sapflow, will allow us to estimate the impact of varying degrees of disease severity on stand-level water flux. Alders are a keystone species and are currently responding to climate change by expanding into the Alaska tundra, increasing abundance in northern Alaska, and migrating into river

  2. OXYGEN AERATION AT NEWTOWN CREEK

    EPA Science Inventory

    A successful initial feasibility investigation of oxygen aeration at the 0.11-cu m/sec (2.5-mgd) municipal wastewater treatment plant in Batavia, New York, prompted a larger demonstration at New York City's 13.6-cu m/sec (310-mgd) Newtown Creek Plant. A 34-mo evaluation was perfo...

  3. Parachute Creek Shale Oil Program

    SciTech Connect

    Not Available

    1981-01-01

    This pamphlet describes Union Oil's shale oil project in the Parachute Creek area of Garfield County, Colorado. The oil shale is estimated to contain 1.6 billion barrels of recoverable oil in the high Mahogany zone alone. Primarily a public relations publication, the report presented contains general information on the history of the project and Union Oil's future plans. (JMT)

  4. Dimerization of quercetin, Diels-Alder vs. radical-coupling approach: a joint thermodynamics, kinetics, and topological study.

    PubMed

    Fourré, Isabelle; Di Meo, Florent; Podloucká, Pavlína; Otyepka, Michal; Trouillas, Patrick

    2016-08-01

    Quercetin is a prototypical antioxidant and prominent member of flavonoids, a large group of natural polyphenols. The oxidation of quercetin may lead to its dimerization, which is a paradigm of the more general polyphenol oligomerization. There exist two opposing mechanisms to describe the dimerization process, namely radical-coupling or Diels-Alder reactions. This work presents a comprehensive rationalization of this dimerization process, acquired from density functional theory (DFT) calculations. It is found that the two-step radical-coupling pathway is thermodynamically and kinetically preferred over the Diels-Alder reaction. This is in agreement with the experimental results showing the formation of only one isomer, whereas the Diels-Alder mechanism would yield two isomers. The evolution in bonding, occurring during these two processes, is investigated using the atoms in molecules (AIM) and electron localization function (ELF) topological approaches. It is shown that some electron density is accumulated between the fragments in the transition state of the radical-coupling reaction, but not in the transition state of the Diels-Alder process. Graphical Abstract Quantum chemistry calculations of the dimerization process of quercetin show that a radical coupling approach is preferred to a Diels-Alder type reaction, in agreement with experimental results. Analysis of the bonding evolution highlights the reaction mechanism. PMID:27449669

  5. Sediment Dynamics and Southern Steelhead Habitat (Oncorhynchus mykiss) in the Matilija Creek Watershed, Southern California

    NASA Astrophysics Data System (ADS)

    Minear, J. T.; Kondolf, G. M.

    2003-12-01

    Matilija Creek, one of two principal forks of the Ventura River, drains 142 km2 in the Transverse Ranges of southern California. Thanks to rapid tectonic uplift and weak clastic rocks, sediment yields exceed 1200 m3/km2 annually. Matilija Dam was built in 1947 with an initial capacity of 8 million m3 and is now nearly full of sediment. The dam is structurally unsafe, blocks anadromous fish migration, and is being considered for removal. The Ventura River has one of the southernmost runs of steelhead trout (Oncorhynchus mykiss), with an average of approximately 2,500 annually migrating up Matilija Creek before the dam was built. The high sediment yields and highly variable flow regime have raised questions about the interactions among high flows, sediment transfer from lower order tributaries to the third order channels used by the fish, and fish life history. Previous studies in Southern California have documented sediment yields (especially following debris flows and fires, and mostly in the San Gabriel Mountains), but the interaction of geomorphic processes and aquatic habitat in this highly episodic environment is not well understood. We used a combination of mapping and survey techniques, sediment traps, grain size analysis, lithologic analysis and scour rods to study intra-annual geomorphic processes and sediment dynamics affecting Southern Steelhead habitat in the Matilija Creek area in 16 study pools over the 2002 and 2003 flow seasons (dry and "normal", respectively) and found little sediment was deposited or scoured from pools. However, other processes not previously recognized significantly affected the steelhead habitat in the study pools including tufa cementation (carbonate deposition) and alder root growth in spawning gravels, as well as seasonal desiccation of some reaches. Removal of Matilija Dam will reopen suitable habitat to steelhead trout, but managers should recognize that habitat quality is likely to vary considerably from year

  6. Magma mixing and the generation of isotopically juvenile silicic magma at Yellowstone caldera inferred from coupling 238U–230Th ages with trace elements and Hf and O isotopes in zircon and Pb isotopes in sanidine

    USGS Publications Warehouse

    Stelten, Mark E.; Cooper, Kari M.; Vazquez, Jorge A.; Reid, Mary R.; Barfod, Gry H.; Wimpenny, Josh; Yin, Qing-Zhu

    2013-01-01

    The nature of compositional heterogeneity within large silicic magma bodies has important implications for how silicic reservoirs are assembled and evolve through time. We examine compositional heterogeneity in the youngest (~170 to 70 ka) post-caldera volcanism at Yellowstone caldera, the Central Plateau Member (CPM) rhyolites, as a case study. We compare 238U–230Th age, trace-element, and Hf isotopic data from zircons, and major-element, Ba, and Pb isotopic data from sanidines hosted in two CPM rhyolites (Hayden Valley and Solfatara Plateau flows) and one extracaldera rhyolite (Gibbon River flow), all of which erupted near the caldera margin ca. 100 ka. The Hayden Valley flow hosts two zircon populations and one sanidine population that are consistent with residence in the CPM reservoir. The Gibbon River flow hosts one zircon population that is compositionally distinct from Hayden Valley flow zircons. The Solfatara Plateau flow contains multiple sanidine populations and all three zircon populations found in the Hayden Valley and Gibbon River flows, demonstrating that the Solfatara Plateau flow formed by mixing extracaldera magma with the margin of the CPM reservoir. This process highlights the dynamic nature of magmatic interactions at the margins of large silicic reservoirs. More generally, Hf isotopic data from the CPM zircons provide the first direct evidence for isotopically juvenile magmas contributing mass to the youngest post-caldera magmatic system and demonstrate that the sources contributing magma to the CPM reservoir were heterogeneous in 176Hf/177Hf at ca. 100 ka. Thus, the limited compositional variability of CPM glasses reflects homogenization occurring within the CPM reservoir, not a homogeneous source.

  7. Magma mixing and the generation of isotopically juvenile silicic magma at Yellowstone caldera inferred from coupling 238U-230Th ages with trace elements and Hf and O isotopes in zircon and Pb isotopes in sanidine

    NASA Astrophysics Data System (ADS)

    Stelten, Mark E.; Cooper, Kari M.; Vazquez, Jorge A.; Reid, Mary R.; Barfod, Gry H.; Wimpenny, Josh; Yin, Qing-zhu

    2013-08-01

    The nature of compositional heterogeneity within large silicic magma bodies has important implications for how silicic reservoirs are assembled and evolve through time. We examine compositional heterogeneity in the youngest (~170 to 70 ka) post-caldera volcanism at Yellowstone caldera, the Central Plateau Member (CPM) rhyolites, as a case study. We compare 238U-230Th age, trace-element, and Hf isotopic data from zircons, and major-element, Ba, and Pb isotopic data from sanidines hosted in two CPM rhyolites (Hayden Valley and Solfatara Plateau flows) and one extracaldera rhyolite (Gibbon River flow), all of which erupted near the caldera margin ca. 100 ka. The Hayden Valley flow hosts two zircon populations and one sanidine population that are consistent with residence in the CPM reservoir. The Gibbon River flow hosts one zircon population that is compositionally distinct from Hayden Valley flow zircons. The Solfatara Plateau flow contains multiple sanidine populations and all three zircon populations found in the Hayden Valley and Gibbon River flows, demonstrating that the Solfatara Plateau flow formed by mixing extracaldera magma with the margin of the CPM reservoir. This process highlights the dynamic nature of magmatic interactions at the margins of large silicic reservoirs. More generally, Hf isotopic data from the CPM zircons provide the first direct evidence for isotopically juvenile magmas contributing mass to the youngest post-caldera magmatic system and demonstrate that the sources contributing magma to the CPM reservoir were heterogeneous in 176Hf/177Hf at ca. 100 ka. Thus, the limited compositional variability of CPM glasses reflects homogenization occurring within the CPM reservoir, not a homogeneous source.

  8. Total Synthesis of the Galbulimima Alkaloids Himandravine and GB17 Using Biomimetic Diels–Alder Reactions of Double Diene Precursors

    PubMed Central

    Larson, Reed T.; Pemberton, Ryan P.; Franke, Jenna M.; Tantillo, Dean J.; Thomson, Regan J.

    2015-01-01

    The enantioselective total syntheses of himandravine and GB17 were completed through a common biomimetic strategy involving Diels–Alder reactions of unusual double diene containing linear precursors. The double diene precursors, containing or lacking a C12 substituent as required to produce GB17 or himandravine, respectively, were found to undergo Diels–Alder reactions to afford mixtures of regioisomeric cycloadducts that map onto the alternative carbocyclic frameworks of both himandravine and GB17. Computational investigations revealed that these Diels–Alder reactions proceed via transition state structures of similar energy that have a high degree of bispericyclic character and that the low levels of regioselectivity observed in the reactions are a consequence of competing orbital interaction and distortion energies. The combined experimental and computational results provide valuable insights into the biosynthesis of the Galbulimima alkaloids. PMID:26305231

  9. Total Synthesis of the Galbulimima Alkaloids Himandravine and GB17 Using Biomimetic Diels-Alder Reactions of Double Diene Precursors.

    PubMed

    Larson, Reed T; Pemberton, Ryan P; Franke, Jenna M; Tantillo, Dean J; Thomson, Regan J

    2015-09-01

    The enantioselective total syntheses of himandravine and GB17 were completed through a common biomimetic strategy involving Diels-Alder reactions of unusual double diene containing linear precursors. The double diene precursors, containing or lacking a C12 substituent as required to produce GB17 or himandravine, respectively, were found to undergo Diels-Alder reactions to afford mixtures of regioisomeric cycloadducts that map onto the alternative carbocyclic frameworks of both himandravine and GB17. Computational investigations revealed that these Diels-Alder reactions proceed via transition state structures of similar energy that have a high degree of bispericyclic character and that the low levels of regioselectivity observed in the reactions are a consequence of competing orbital interaction and distortion energies. The combined experimental and computational results provide valuable insights into the biosynthesis of the Galbulimima alkaloids. PMID:26305231

  10. Recent Advances in Inverse-Electron-Demand Hetero-Diels-Alder Reactions of 1-Oxa-1,3-Butadienes.

    PubMed

    Pałasz, Aleksandra

    2016-06-01

    This review is an endeavor to highlight the progress in the inverse-electron-demand hetero-Diels-Alder reactions of 1-oxa-1,3-butadienes in recent years. The huge number of examples of 1-oxadienes cycloadditions found in the literature clearly demonstrates the incessant importance of this transformation in pyran ring synthesis. This type of reaction is today one of the most important methods for the synthesis of dihydropyrans which are the key building blocks in structuring of carbohydrate and other natural products. Two different modes, inter- and intramolecular, of inverse-electron-demand hetero-Diels-Alder reactions of 1-oxadienes are discussed. The domino Knoevenagel hetero-Diels-Alder reactions are also described. In recent years the use of chiral Lewis acids, chiral organocatalysts, new optically active heterodienes or dienophiles have provided enormous progress in asymmetric synthesis. Solvent-free and aqueous hetero-Diels-Alder reactions of 1-oxabutadienes were also investigated. The reactivity of reactants, selectivity of cycloadditions, and chemical stability in aqueous solutions and under physiological conditions were taken into account to show the potential application of the described reactions in bioorthogonal chemistry. New bioorthogonal ligation by click inverse-electron-demand hetero-Diels-Alder cycloaddition of in situ-generated 1-oxa-1,3-butadienes and vinyl ethers was developed. It seems that some of the hetero-Diels-Alder reactions described in this review can be applied in bioorthogonal chemistry because they are selective, non-toxic, and can function in biological conditions taking into account pH, an aqueous environment, and temperature. PMID:27573264

  11. Diarylheptanoids from green alder bark and their potential for DNA protection.

    PubMed

    Novaković, Miroslav; Stanković, Miroslava; Vučković, Ivan; Todorović, Nina; Trifunović, Snežana; Apostolović, Danijela; Mandić, Boris; Veljić, Milan; Marin, Petar; Tešević, Vele; Vajs, Vlatka; Milosavljević, Slobodan

    2014-06-01

    Nine diarylheptanoids, 1-9, catechin (11), and a phenolic glucoside, 10, were isolated from the bark of green alder (Alnus viridis). Four of the isolated compounds, i.e., 2, 5, 8, 10, are new. The structures of 1-11 were determined on the basis of spectroscopic data. All isolated compounds were evaluated for their in vitro protective effects on chromosome aberrations in peripheral human lymphocytes using cytokinesis-block micronucleus (CBMN) assay. Almost all of them exerted a pronounced effect of decreasing DNA damage of human lymphocytes, acting stronger than the known synthetic protector amifostine. PMID:24934673

  12. Hetero-Diels-Alder reactions of hetaryl and aryl thioketones with acetylenic dienophiles.

    PubMed

    Mlostoń, Grzegorz; Grzelak, Paulina; Mikina, Maciej; Linden, Anthony; Heimgartner, Heinz

    2015-01-01

    Selected hetaryl and aryl thioketones react with acetylenecarboxylates under thermal conditions in the presence of LiClO4 or, alternatively, under high-pressure conditions (5 kbar) at room temperature yielding thiopyran derivatives. The hetero-Diels-Alder reaction occurs in a chemo- and regioselective manner. The initially formed [4 + 2] cycloadducts rearrange via a 1,3-hydrogen shift sequence to give the final products. The latter were smoothly oxidized by treatment with mCPBA to the corresponding sulfones. PMID:26124858

  13. On the theory of Brownian motion with the Alder-Wainwright effect

    NASA Astrophysics Data System (ADS)

    Okabe, Yasunori

    1986-12-01

    The Stokes-Boussinesq-Langevin equation, which describes the time evolution of Brownian motion with the Alder-Wainwright effect, can be treated in the framework of the theory of KMO-Langevin equations which describe the time evolution of a real, stationary Gaussian process with T-positivity (reflection positivity) originating in axiomatic quantum field theory. After proving the fluctuation-dissipation theorems for KMO-Langevin equations, we obtain an explicit formula for the deviation from the classical Einstein relation that occurs in the Stokes-Boussinesq-Langevin equation with a white noise as its random force. We are interested in whether or not it can be measured experimentally.

  14. Conformations of allylic fluorides and stereoselectivities of their diels-alder cycloadditions.

    PubMed

    Grée, D; Vallerie, L; Grée, R; Toupet, L; Washington, I; Pelicier, J P; Villacampa, M; Pérez, J M; Houk, K N

    2001-04-01

    The preparations of new allylic fluorides from the corresponding alcohols are reported. Conformational analysis is achieved by comparison of experimental NMR measurements with theoretical (B3LYP) calculations of relative energies of conformers and J(H,H) and J(H,F) coupling constants. The Diels-Alder reactions of allylic fluorides are investigated experimentally and theoretically. The stereoselectivities of the reactions were determined by NMR analysis and, in one case, by X-ray crystallography. Theoretical predictions of stereoselectivity based upon transition state modeling provided good agreement with experiment. Theoretical models for allylic fluorides and transition state conformations are reported. PMID:11281778

  15. The Nitrosocarbonyl Hetero-Diels–Alder Reaction as a Useful Tool for Organic Syntheses

    PubMed Central

    Bodnar, Brian S.

    2014-01-01

    Organic transformations that result in the formation of multiple covalent bonds within the same reaction are some of the most powerful tools in synthetic organic chemistry. Nitrosocarbonyl hetero-Diels–Alder (HDA) reactions allow for the simultaneous stereospecific introduction of carbon–nitrogen and carbon–oxygen bonds in one synthetic step, and provide direct access to 3,6-dihydro-1,2-oxazines. This Review describes the development of the nitrosocarbonyl HDA reaction and the utility of the resulting oxazine ring in the synthesis of a variety of important, biologically active molecules. PMID:21520360

  16. Insight on mendable resin made by combining Diels-Alder epoxy adducts with DGEBA

    NASA Astrophysics Data System (ADS)

    Dello Iacono, S.; Martone, A.; Filippone, G.; Acierno, D.; Zarrelli, M.; Giordano, M.; Amendola, E.

    2016-05-01

    Formation of micro-cracks is a critical problem in polymers and polymer composites during their service in structural applications. In this context, materials endowed with self-healing features would lead to the next polymers generation. In the present paper, an epoxy system integrating Diels-Alder epoxy adducts is investigated by thermal and spectroscopic analysis. The direct and retro D-A reaction have been studied by FTIR and specific absorption bands have been identified. Finally, mechanical tests have been performed on the system. The polymer is able to heal fracture and micro-cracks recovering its stiffness after a thermal treatment.

  17. Silver Nanoparticle-Catalyzed Diels-Alder Cycloadditions of 2′-Hydroxychalcones

    PubMed Central

    Cong, Huan; Becker, Clinton F.; Elliott, Sean J.; Grinstaff, Mark W.; Porco, John A.

    2010-01-01

    Metal nanoparticles are currently being employed as catalysts for a number of classical chemical transformations. In contrast, identification of novel reactions of nanoparticles, especially towards the synthesis of complex natural products and derivatives, is highly underdeveloped and represents a bourgeoning area in chemical synthesis. Herein, we report silica-supported silver nanoparticles as solid, recyclable catalysts for Diels-Alder cycloadditions of 2′-hydroxychalcones and dienes in high yield and turnover number. The use of silver nanoparticle catalysts is further demonstrated by the total synthesis of the cytotoxic natural product panduratin A employing a highly electron-rich dienophile and Lewis acid-sensitive diene. PMID:20443601

  18. Diels-Alder reactions of five-membered heterocycles containing one heteroatom

    PubMed Central

    Ding, Xiaoyuan; Nguyen, Son T.; Williams, John D.; Peet, Norton P.

    2015-01-01

    Diels-Alder reactions of five-membered heterocycles containing one heteroatom with an N-arylmaleimide were studied. Cycloaddition of 2,5-dimethylfuran (4) with 2-(4-methylphenyl)maleimide (3) in toluene at 60 °C gave bicyclic adduct 5. Cycloadditions of 3 with 2,5-dimethylthiophene (11) and 1,2,5-trimethylpyrrole (14) were also studied. Interestingly, the bicyclic compound 5 cleanly rearranged, with loss of water, when treated with p-toluenesulfonic acid in toluene at 80 °C to give 4,7-dimethyl-2-p-tolylisoindoline-1,3-dione (6). PMID:25838605

  19. Structural Modification of Sol-Gel Materials through Retro Diels-Alder Reaction

    SciTech Connect

    SHALTOUT,RAAFAT M.; LOY,DOUGLAS A.; MCCLAIN,MARK D.; PRABAKAR,SHESHASAYANA; GREAVES,JOHN; SHEA,KENNETH J.

    1999-12-08

    Hydrolysis and condensation of organically bridged bis-triethoxysilanes, (EtO){sub 3}Si-R-Si(OEt){sub 3}, results in the formation of three dimensional organic/inorganic hybrid networks (Equation 1). Properties of these materials, including porosity, are dependent on the nature of the bridging group, R. Flexible groups (akylene-spacers longer than five carbons in length) polymerize under acidic conditions to give non-porous materials. Rigid groups (such as arylene-, alkynylene-, or alkenylene) form non-porous, microporous, and macroporous gels. In many cases the pore size distributions are quite narrow. One of the motivations for preparing hybrid organic-inorganic materials is to extend the range of properties available with sol-gel systems by incorporating organic groups into the inorganic network. For example, organically modified silica gels arc either prepared by co-polymerizing an organoalkoxysilane with a silica precursor or surface silylating the inorganic gel. This can serve to increase hydrophobicity or to introduce some reactive organic functionality. However, the type and orientation of these organic functionalities is difficult to control. Furthermore, many organoalkoxysilanes can act to inhibitor even prevent gelation, limiting the final density of organic functionalities. We have devised a new route for preparing highly functionalized pores in hybrid materials using bridging groups that are thermally converted into the desired functionalities after the gel has been obtained. In this paper, we present the preparation and characterization of bridged polysilsesquioxanes with Diels-Alder adducts as the bridging groups from the sol-gel polymerization of monomers 2 and 4. The bridging groups are constructed such that the retro Diela-Alder reaction releases the dienes and leaves the dienophiles as integral parts of the network polymers. In the rigid architecture of a xerogel, this loss of organic functionality should liberate sufficient space to modify the

  20. Energy storage capacity of reversible liquid phase Diels-Alder reactions as determined by drop calorimetry

    SciTech Connect

    Chung, C.P.

    1983-01-01

    Several Diels-Alder reactions were evaluated as possible candidates for energy storage. The goal was to use simple drop calorimetry to screen reactions and to identify those with high energy storage capacities. The dienes used were furan and substituted furans. The dienophiles used were maleic anhydride and substituted maleic anhydrides. Sixteen reactions have been examined. Three had energy storage capacities that were increased due to reaction (maleic anhydride and 2-methyl furan, maleic anhydride and 2-ethyl furan, maleic anhydride and 2,5-dimethyl furan). The remaining thirteen showed no increase in apparent heat capacity due to reaction.

  1. Continuous-flow stereoselective organocatalyzed Diels-Alder reactions in a chiral catalytic "homemade" HPLC column.

    PubMed

    Chiroli, Valerio; Benaglia, Maurizio; Cozzi, Franco; Puglisi, Alessandra; Annunziata, Rita; Celentano, Giuseppe

    2013-07-19

    Continuous-flow organocatalyzed Diels-Alder reactions have been performed with excellent enantioselectivity for the first time in a chiral "homemade" HPLC column, packed with silica on which a MacMillan catalyst has been supported by a straightforward immobilization procedure. The versatility of the system was also proven by running with the same column continuous-flow stereoselective reactions with three different substrates, showing that the catalytic reactor may efficiently work in continuo for more than 150 h; the regeneration of the HPLC column was also demonstrated, allowing to further extend the activity of the reactor to more than 300 operating hours. PMID:23808663

  2. Control of femtosecond laser driven retro-Diels-Alder-like reaction of dicyclopentadiene

    PubMed Central

    Das, Dipak Kumar; Goswami, Tapas; Goswami, Debabrata

    2013-01-01

    Using femtosecond time resolved degenerate pump-probe mass spectrometry coupled with simple linearly chirped frequency modulated pulse, we elucidate that the dynamics of retro-Diels-Alder-like reaction of diclopentadiene (DCPD) to cyclopentadiene (CPD) in supersonic molecular beam occurs in ultrafast time scale. Negatively chirped pulse enhances the ion yield of CPD, as compared to positively chirped pulse. This indicates that by changing the frequency (chirp) of the laser pulse we can control the ion yield of a chemical reaction. PMID:23814449

  3. Hetero-Diels–Alder reactions of hetaryl and aryl thioketones with acetylenic dienophiles

    PubMed Central

    Grzelak, Paulina; Mikina, Maciej; Linden, Anthony

    2015-01-01

    Summary Selected hetaryl and aryl thioketones react with acetylenecarboxylates under thermal conditions in the presence of LiClO4 or, alternatively, under high-pressure conditions (5 kbar) at room temperature yielding thiopyran derivatives. The hetero-Diels–Alder reaction occurs in a chemo- and regioselective manner. The initially formed [4 + 2] cycloadducts rearrange via a 1,3-hydrogen shift sequence to give the final products. The latter were smoothly oxidized by treatment with mCPBA to the corresponding sulfones. PMID:26124858

  4. GRAHAM CREEK ROADLESS AREA, TEXAS.

    USGS Publications Warehouse

    Houser, B.B.; Ryan, George S.

    1984-01-01

    A geologic and geochemical investigation of the Graham Creek Roadless Area, Texas was conducted. The area has a probable mineral-resource potential for oil and gas. The roadless area contains a deposit of kaolinite clay similar to deposits being mined west of the area; the southeast part of the roadless area has a substantiated kaolinite clay resource potential. Semectite clay and sand deposits also are present in the area but these resources are relatively abundant throughout the region. Detailed analyses of well logs from the vicinity of the Graham Creek Roadless Area in conjunction with study of seismic data are necessary to determine if subsurface stratigraphy and structure are favorable for the accumulation of oil and gas.

  5. PINE CREEK ROADLESS AREA, OREGON.

    USGS Publications Warehouse

    Walker, George W.; Denton, David K., Jr.

    1984-01-01

    Examination of the Pine Creek Roadless Area, Oregon indicates that there is little likelihood for the occurrence of energy or metallic mineral resources in the area. No mines or mineral prospects were identified during the investigation. Although nearby parts of Harney Basin are characterized by higher than normal heat flow, indicating that the region as a whole may have some as yet undefined potential for the occurrence of the geothermal energy resources, no potential for this resource was identified in the roadless area.

  6. The Inverse Demand Oxa-Diels-Alder Reaction of Resorcinarenes: An Experimental and Theoretical Analysis of Regioselectivity and Diastereoselectivity.

    PubMed

    Stefańska, Karolina; Jędrzejewska, Hanna; Wierzbicki, Michał; Szumna, Agnieszka; Iwanek, Waldemar

    2016-07-15

    The Diels-Alder reaction enables introduction of new functionalities onto the resorcinarene skeleton with simultaneous generation of new stereogenic centers and expansion of the internal cavity. We present highly regio- and diastereoselective inverse electron demand oxa-Diels-Alder reactions of resorcinarene ortho-quinone methide with benzofuran and indene, each generating 12 new stereogenic centers. The mechanism and reasons for regioselectivity and diastereoselectivity were analyzed using theoretical calculations (NBO charges, Fukui functions, transition state energies, and thermodynamic stability of the products). Enantiomers were separated, and their configurations were determined by comparison of experimental and theoretical electronic circular dichroism spectra. PMID:27336857

  7. Chiral Pyridinium Phosphoramide as a Dual Brønsted Acid Catalyst for Enantioselective Diels-Alder Reaction.

    PubMed

    Nishikawa, Yasuhiro; Nakano, Saki; Tahira, Yuu; Terazawa, Kanako; Yamazaki, Ken; Kitamura, Chitoshi; Hara, Osamu

    2016-05-01

    Chiral pyridinium phosphoramide 1·HX was designed to be a new class of chiral Brønsted acid catalyst in which both the pyridinium proton and the adjacent imide-like proton activated by the electron-withdrawing pyridinium moiety could work cooperatively as strong dual proton donors. The potential of 1·HX was shown in the enantioselective Diels-Alder reactions of 1-amino dienes with various dienophiles including N-unsubstituted maleimide, which has yet to be successfully used in an asymmetric Diels-Alder reaction. PMID:27093584

  8. Medium-Ring Effects on the Endo/Exo Selectivity of the Organocatalytic Intramolecular Diels-Alder Reaction.

    PubMed

    Hooper, Joel F; James, Natalie C; Bozkurt, Esra; Aviyente, Viktorya; White, Jonathan M; Holland, Mareike C; Gilmour, Ryan; Holmes, Andrew B; Houk, K N

    2015-12-18

    The intramolecular Diels-Alder reaction has been used as a powerful method to access the tricyclic core of the eunicellin natural products from a number of 9-membered-ring precursors. The endo/exo selectivity of this reaction can be controlled through a remarkable organocatalytic approach, employing MacMillan's imidazolidinone catalysts, although the mechanistic origin of this selectivity remains unclear. We present a combined experimental and density functional theory investigation, providing insight into the effects of medium-ring constraints on the organocatalyzed intramolecular Diels-Alder reaction to form the isobenzofuran core of the eunicellins. PMID:26560246

  9. Enantio- and periselective nitroalkene Diels-Alder reactions catalyzed by helical-chiral hydrogen bond donor catalysts.

    PubMed

    Peng, Zhili; Narcis, Maurice J; Takenaka, Norito

    2013-01-01

    Helical-chiral double hydrogen bond donor catalysts promote the nitroalkene Diels-Alder reaction in an enantio- and periselective manner. This represents the first asymmetric catalytic nitroalkene Diels-Alder reaction via LUMO-lowering catalysis. To gain an insight into this new process, the substrate scope of our catalyst was investigated by exploiting readily available 5-substituted pentamethylcyclopentadienes. The catalyst was found to tolerate dienes with different steric demands as well as dienes substituted with heteroatoms. The synthetic utility of 5-substituted pentamethylcyclopentadienes is rather limited, and thus we have developed a three-step route to 1,4,5,5-tetrasubstituted cyclopentadienes from commercially available ketones. PMID:23966083

  10. [sup 40]Ar/[sup 39]Ar isotopic dates from the Cripple Creek gold-Telluride district, Colorado: Constraints on the timing of magmatism and mineralization

    SciTech Connect

    Kelley, K.D.; Snee, L.W. ); Thompson, T.B. . Dept. of Earth Resources)

    1993-04-01

    The Cripple Creek district is within a Tertiary diatreme-intrusive complex, a steep-walled basin in Proterozoic pelitic and igneous rocks that is filled with terrigenous sedimentary rocks, volcanic and hydrothermal breccias, and tuffs. The orebodies occur as veins in Proterozoic and Tertiary rocks or as deposits localized within hydrothermal breccia bodies or disseminated in diatreme breccias. [sup 40]Ar/[sup 39]Ar dates from igneous rocks demonstrate the approximately contemporaneous emplacement of the most differentiated phonolitic rocks. Three sanidine samples from phonolite yield apparent ages ranging from 30.9 [+-] 0.1 to 31.8 [+-] 0.1 Ma (1 sigma). Biotite and sanidine age spectra from relatively less differentiated tephriphonolite are discordant; the emplacement age is estimated to be between 31.4 [+-] 0.1 and 32.5 [+-] 0.1 Ma. A maximum age of 31.5 [+-] 0.1 Ma was obtained on a whole-rock sample of trachyandesite. The mafic phonolitic rocks are relatively younger. A sample of the Isabella dike, a phonotephrite dike cutting phonolite, yields a whole-rock age of 28.7 [+-] 0.04 Ma. The data suggest that mineralization both predates and postdates emplacement of the mafic phonolitic rocks. Hydrothermal biotite in a vein cutting phonolite yields an age of 29.9 [+-] 0.1 Ma. The age spectrum of adularia from a vein cutting volcaniclastic rocks is difficult to interpret due to the presence of excess argon, but an age is estimated to be between 29.5 and 30.4 Ma. In the vicinity of the phonotephrite dike, field evidence suggests that vein mineralization postdates emplacement of the dike; potassium feldspar from potassium altered phonolite in the vicinity of mineralized rock yields ages of 28.2 [+-] 0.1 and 28.8 [+-] 0.1 Ma.

  11. Floods in Starkweather Creek basin, Madison, Wisconsin

    USGS Publications Warehouse

    Lawrence, Carl L.; Holmstrom, Barry K.

    1972-01-01

    The reaches evaluated are (1) Starkweather Creek and West Branch Starkweather Creek, for a distance of 6.0 river miles from the mouth at Lake Monona upstream to the U.S. Highway 51 crossing north of Truax Field; and (2) East Branch Starkweather Creek (2.8 river miles), from its confluence with the West Branch near Milwaukee Street upstream to a point near the Interstate Highway 90-94 crossing.

  12. Traveltime characteristics of Gore Creek and Black Gore Creek, upper Colorado River basin, Colorado

    USGS Publications Warehouse

    Gurdak, Jason J.; Spahr, Norman E.; Szmajter, Richard J.

    2002-01-01

    In the Rocky Mountains of Colorado, major highways are often constructed in stream valleys. In the event of a vehicular accident involving hazardous materials, the close proximity of highways to the streams increases the risk of contamination entering the streams. Recent population growth has contributed to increased traffic volume along Colorado highways and has resulted in increased movement of hazardous materials, particularly along Interstate 70. Gore Creek and its major tributary, Black Gore Creek, are vulnerable to such contamination from vehicular accidents along Interstate 70. Gore Creek, major tributary of the Eagle River, drains approximately 102 square miles, some of which has recently undergone significant urban development. The headwaters of Gore Creek originate in the Gore Range in the eastern part of the Gore Creek watershed. Gore Creek flows west to the Eagle River. Beginning at the watershed boundary on Vail Pass, southeast of Vail Ski Resort, Interstate 70 parallels Black Gore Creek and then closely follows Gore Creek the entire length of the watershed. Interstate 70 crosses Gore Creek and tributaries 20 times in the watershed. In the event of a vehicular accident involving a contaminant spill into Gore Creek or Black Gore Creek, a stepwise procedure has been developed for water-resource managers to estimate traveltimes of the leading edge and peak concentration of a conservative contaminant. An example calculating estimated traveltimes for a hypothetical contaminant release in Black Gore Creek is provided. Traveltime measurements were made during May and September along Black Gore Creek and Gore Creek from just downstream from the Black Lakes to the confluence with the Eagle River to account for seasonal variability in stream discharge. Fluorometric dye injection of rhodamine WT and downstream dye detection by fluorometry were used to measure traveltime characteristics of Gore Creek and Black Gore Creek. During the May traveltime measurements

  13. Sediment transport through a tidal creek

    NASA Astrophysics Data System (ADS)

    Green, Malcolm O.; Hancock, Nicole J.

    2012-08-01

    A 3-month field experiment was conducted at Henderson Creek, New Zealand. The data show how tidal creeks that are an extension of the freshwater drainage network (as opposed to tidal creeks that are part of an estuarine distributary network with no direct connection to the land) variously import, export and deposit fine sediment sourced from both landward and seaward of the creek, depending on the wind and freshwater runoff, and modulated by the tide. During freshwater spates, saltwater was largely displaced from the tidal creek at low tide, and sediment sourced from the land was deposited inside the tidal creek and exported to the wider estuary beyond the base of the creek. In one spate, during which 80 mm of rain fell in less than one day, 580 t of sediment was sourced from landward of the tidal creek, and a maximum of 33% of this was exported to the wider estuary. Between rainstorms when it was calm, sediment was returned from the wider estuary by tidal currents (but not necessarily the same sediment that was exported during spates), and sediment was also eroded from the middle reaches of the tidal creek and transported to the upper reaches, where it was deposited. The up-estuary deposition is explainable in Lagrangian terms as a type of settling lag, which results in an asymmetrical response of suspended-sediment concentration to current speed in the tidal creek. The return of sediment to the tidal creek between spates was greatly enhanced by wind waves that resuspended sediments from the intertidal flats of the wider estuary, with that sediment being transported by tidal currents into the tidal creek where it was deposited, largely in the middle reaches. There is a broad consensus that waves drive a net loss of sediment from intertidal flats to offshore, which reverses a net accumulation of sediment on intertidal flats during calm weather. In contrast, waves on the intertidal flats outside the mouth of Henderson Creek initiate net landward transport of

  14. DEEP CREEK AND MUD CREEK, TWIN FALLS, IDAHO. WATER QUALITY STATUS REPORT, 1986

    EPA Science Inventory

    Deep Creek and Mud Creek are located in Twin Falls County near Buhl, Idaho (17040212). From April through October, these creeks convey irrigation drainage water from the western part of the Twin Falls irrigation tract to the Snake River. During 1986, water quality surveys were ...

  15. LIGHTNING CREEK, PACK RIVER, AND SAND CREEK, BONNER COUNTY, IDAHO - WATER QUALITY SUMMARY, 1978

    EPA Science Inventory

    In Water Year 1978, water quality studies were conducted on Lightning Creek, Pack River, and Sand Creek in Bonner County, Idaho (17010214, 17010213) to determine the present status of the streams. Water quality in Lightning Creek was generally very high. No violations of standa...

  16. 33 CFR 110.79c - Fish Creek Harbor, Fish Creek, Wisconsin.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Fish Creek Harbor, Fish Creek, Wisconsin. 110.79c Section 110.79c Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.79c Fish Creek Harbor, Fish...

  17. 33 CFR 110.79c - Fish Creek Harbor, Fish Creek, Wisconsin.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Fish Creek Harbor, Fish Creek, Wisconsin. 110.79c Section 110.79c Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.79c Fish Creek Harbor, Fish...

  18. 75 FR 40034 - Northeastern Tributary Reservoirs Land Management Plan, Beaver Creek, Clear Creek, Boone, Fort...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-13

    ... (Significant Threat), or Rank 3 (Lesser Threat) on the Tennessee Exotic Plant Pest Council list of Invasive... Northeastern Tributary Reservoirs Land Management Plan, Beaver Creek, Clear Creek, Boone, Fort Patrick Henry... Land Management Plan (NTRLMP) for the 4,933 acres of TVA-managed public land on Beaver Creek,...

  19. The Hexadehydro-Diels-Alder Cycloisomerization Reaction Proceeds by a Stepwise Mechanism.

    PubMed

    Wang, Tao; Niu, Dawen; Hoye, Thomas R

    2016-06-29

    We report here experiments showing that the hexadehydro-Diels-Alder (HDDA) cycloisomerization reaction proceeds in a stepwise manner-i.e., via a diradical intermediate. Judicious use of substituent effects was decisive. We prepared (i) a series of triyne HDDA substrates that differed only in the R group present on the remote terminus of the diynophilic alkyne and (ii) an analogous series of dienophilic alkynes (n-C7H15COC≡CR) for use in classical Diels-Alder (DA) reactions (with 1,3-cyclopentadiene). The R groups were CF3, CHO, COMe/Et, CO2Me, CONMe2/Et2, H, and 1-propynyl. The relative rates of both the HDDA cyclization reactions and the simple DA cycloadditions were measured. The reactivity trends revealed a dramatic difference in the behaviors of the CF3 (slowest HDDA and nearly fastest DA) and 1-propynyl (fastest HDDA and slowest DA) containing members of each series. These differences can be explained by invoking radical-stabilizing energies rather than electron-withdrawing effects as the dominating feature of the HDDA reaction. PMID:27266843

  20. New Insights into the Diels-Alder Reaction of Graphene Oxide.

    PubMed

    Brisebois, Patrick P; Kuss, Christian; Schougaard, Steen B; Izquierdo, Ricardo; Siaj, Mohamed

    2016-04-18

    Graphene oxide is regarded as a major precursor for graphene-based materials. The development of graphene oxide based derivatives with new functionalities requires a thorough understanding of its chemical reactivity, especially for canonical synthetic methods such as the Diels-Alder cycloaddition. The Diels-Alder reaction has been successfully extended with graphene oxide as a source of diene by using maleic anhydride as a dienophile, thereby outlining the presence of the cis diene present in the graphene oxide framework. This reaction provides fundamental information for understanding the exact structure and chemical nature of graphene oxide. On the basis of high-resolution (13) C-SS NMR spectra, we show evidence for the formation of new sp(3) carbon centers covalently bonded to graphene oxide following hydrolysis of the reaction product. DFT calculations are also used to show that the presence of a cis dihydroxyl and C vacancy on the surface of graphene oxide are promoting the reaction with significant negative reaction enthalpies. PMID:26953926

  1. 1. Deep Creek Road, picnic pavilion Great Smoky Mountains ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Deep Creek Road, picnic pavilion - Great Smoky Mountains National Park Roads & Bridges, Deep Creek Road, Between Park Boundary near Bryson City & Deep Creek Campground, Gatlinburg, Sevier County, TN

  2. 2. Deep Creek Road, old bridge at campground entrance. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Deep Creek Road, old bridge at campground entrance. - Great Smoky Mountains National Park Roads & Bridges, Deep Creek Road, Between Park Boundary near Bryson City & Deep Creek Campground, Gatlinburg, Sevier County, TN

  3. 2. Big Creek Road, worm fence and road at trailhead. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Big Creek Road, worm fence and road at trailhead. - Great Smoky Mountains National Park Roads & Bridges, Big Creek Road, Between State Route 284 & Big Creek Campground, Gatlinburg, Sevier County, TN

  4. 7. Cable Creek Bridge after completion. Zion National Park negative ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. Cable Creek Bridge after completion. Zion National Park negative number 1485, classification series 002, 12. - Floor of the Valley Road, Cable Creek Bridge, Spanning Cable Creek on Floor of Valley, Springdale, Washington County, UT

  5. 8. DETAIL VIEW OF DATEPLATE WHICH READS 'HARP CREEK, LUTEN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. DETAIL VIEW OF DATEPLATE WHICH READS 'HARP CREEK, LUTEN BRIDGE CO., CONTRACTOR, ARKANSAS STATE HIGHWAY DEPARTMENT, 1928' - Harp Creek Bridge, Spans Harp Creek at State Highway 7, Harrison, Boone County, AR

  6. Detail view of the Ten Mile Creek Bridge, view looking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail view of the Ten Mile Creek Bridge, view looking northeast at the modified "X" bracing and concrete hangers. - Ten Mile Creek Bridge, Spanning Ten Mile Creek on Oregon Coast Highway, Yachats, Lincoln County, OR

  7. Detail view of the Ten Mile Creek Bridge decorative concrete ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail view of the Ten Mile Creek Bridge decorative concrete arched balustrade at southeast corner of bridge, view looking east. - Ten Mile Creek Bridge, Spanning Ten Mile Creek on Oregon Coast Highway, Yachats, Lincoln County, OR

  8. Detail perspective view of the Ten Mile Creek Bridge arch, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail perspective view of the Ten Mile Creek Bridge arch, decorative cantilevered balustrade, and floor beams. - Ten Mile Creek Bridge, Spanning Ten Mile Creek on Oregon Coast Highway, Yachats, Lincoln County, OR

  9. Elevation view of the Spring Creek Bridge, view looking east. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Elevation view of the Spring Creek Bridge, view looking east. - Spring Creek Bridge, Spanning Spring Creek at Milepoint 253.98 on Oregon to California Highway (US Route 97), Chiloquin, Klamath County, OR

  10. Approach view of the Spring Creek Bridge, view looking south. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Approach view of the Spring Creek Bridge, view looking south. - Spring Creek Bridge, Spanning Spring Creek at Milepoint 253.98 on Oregon to California Highway (US Route 97), Chiloquin, Klamath County, OR

  11. General perspective view of the Spring Creek Bridge, view looking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    General perspective view of the Spring Creek Bridge, view looking east. - Spring Creek Bridge, Spanning Spring Creek at Milepoint 253.98 on Oregon to California Highway (US Route 97), Chiloquin, Klamath County, OR

  12. General perspective view of the Spring Creek Bridge, view looking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    General perspective view of the Spring Creek Bridge, view looking southeast. - Spring Creek Bridge, Spanning Spring Creek at Milepoint 253.98 on Oregon to California Highway (US Route 97), Chiloquin, Klamath County, OR

  13. Topographic view of the Spring Creek Bridge and Collier State ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Topographic view of the Spring Creek Bridge and Collier State Park, view looking east. - Spring Creek Bridge, Spanning Spring Creek at Milepoint 253.98 on Oregon to California Highway (US Route 97), Chiloquin, Klamath County, OR

  14. General perspective view of the Spring Creek Bridge, view looking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    General perspective view of the Spring Creek Bridge, view looking northwest. - Spring Creek Bridge, Spanning Spring Creek at Milepoint 253.98 on Oregon to California Highway (US Route 97), Chiloquin, Klamath County, OR

  15. Approach view of the Spring Creek Bridge, view looking north. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Approach view of the Spring Creek Bridge, view looking north. - Spring Creek Bridge, Spanning Spring Creek at Milepoint 253.98 on Oregon to California Highway (US Route 97), Chiloquin, Klamath County, OR

  16. 3. MOSIER CREEK BRIDGE LOOKING 135 DEGREES SOUTHEAST AT NORTH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. MOSIER CREEK BRIDGE LOOKING 135 DEGREES SOUTHEAST AT NORTH ELEVATION. - Historic Columbia River Highway, Mosier Creek Bridge, Spanning Mosier Creek carrying Historic Columbia River Highway, Troutdale, Multnomah County, OR

  17. EAGLE CREEK BRIDGE, EAST ELEVATION, SUBSTRUCTURE DETAIL LOOKING 333 DEGREES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    EAGLE CREEK BRIDGE, EAST ELEVATION, SUBSTRUCTURE DETAIL LOOKING 333 DEGREES NORTH-NORTHWEST - Historic Columbia River Highway, Eagle Creek Bridge, Spanning Eagle Creek on Historic Columbia River Highway, Troutdale, Multnomah County, OR

  18. 4. MOSIER CREEK BRIDGE LOOKING 202 DEGREES SOUTHWEST AT NORTH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. MOSIER CREEK BRIDGE LOOKING 202 DEGREES SOUTHWEST AT NORTH ELEVATION. - Historic Columbia River Highway, Mosier Creek Bridge, Spanning Mosier Creek carrying Historic Columbia River Highway, Troutdale, Multnomah County, OR

  19. NORTH ELEVATION OF MULTNOMAH CREEK BRIDGE, VIEW LOOKING 130 DEGREES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    NORTH ELEVATION OF MULTNOMAH CREEK BRIDGE, VIEW LOOKING 130 DEGREES SOUTHEAST - Historic Columbia River Highway, Multnomah Creek Bridge, Historic Columbia River Highway spanning Multnomah Creek, Troutdale, Multnomah County, OR

  20. 1. MOSIER CREEK BRIDGE LOOKING NORTHEAST FROM SOUTHEAST CORNER AT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. MOSIER CREEK BRIDGE LOOKING NORTHEAST FROM SOUTHEAST CORNER AT BRIDGE SURFACE. - Historic Columbia River Highway, Mosier Creek Bridge, Spanning Mosier Creek carrying Historic Columbia River Highway, Troutdale, Multnomah County, OR

  1. DETAIL OF MULTNOMAH CREEK BRIDGE, LOOKING 25 DEGREES NORTHNORTHEAST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF MULTNOMAH CREEK BRIDGE, LOOKING 25 DEGREES NORTH-NORTHEAST - Historic Columbia River Highway, Multnomah Creek Bridge, Historic Columbia River Highway spanning Multnomah Creek, Troutdale, Multnomah County, OR

  2. EAGLE CREEK BRIDGE, EAST ELEVATION, VIEW LOOKING 290 DEGREES WESTNORTHWEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    EAGLE CREEK BRIDGE, EAST ELEVATION, VIEW LOOKING 290 DEGREES WEST-NORTHWEST - Historic Columbia River Highway, Eagle Creek Bridge, Spanning Eagle Creek on Historic Columbia River Highway, Troutdale, Multnomah County, OR

  3. 3. EAGLE CREEK RECREATION AREA, VIEW OF PICNIC AREA WITH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. EAGLE CREEK RECREATION AREA, VIEW OF PICNIC AREA WITH COMMUNITY KITCHEN IN BACKGROUND. - Historic Columbia River Highway, Eagle Creek Recreation Area, Historic Columbia River Highway at Eagle Creek, Troutdale, Multnomah County, OR

  4. 1. OVERALL VIEW OF LOBOS CREEK INLET STRUCTURE (#1786), LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. OVERALL VIEW OF LOBOS CREEK INLET STRUCTURE (#1786), LOOKING SOUTHWEST - Presidio Water Treatment Plant, Lobos Creek Inlet Structure, East of Lobos Creek at Baker Beach, San Francisco, San Francisco County, CA

  5. 3. Threequarter view of Oak Creek Bridge behind visitor center ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. Three-quarter view of Oak Creek Bridge behind visitor center facing southwest - Oak Creek Administrative Center, One half mile east of Zion-Mount Carmel Highway at Oak Creek, Springdale, Washington County, UT

  6. 59. Credit FM. Flood waters on South Battle Creek next ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    59. Credit FM. Flood waters on South Battle Creek next to powerhouse. Note height of water in relation to tailraces. - Battle Creek Hydroelectric System, Battle Creek & Tributaries, Red Bluff, Tehama County, CA

  7. 1. Salmon Creek Diversion Dam, weir (to left), sand and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Salmon Creek Diversion Dam, weir (to left), sand and silt sluice gate (center), main canal headworks (to right), view to northwest - Salmon Creek Diversion Dam, Salmon Creek, Okanogan, Okanogan County, WA

  8. 2. Salmon Creek Diversion Dam, overview, diversion weir center foreground, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Salmon Creek Diversion Dam, overview, diversion weir center foreground, headworks overflow weir to center left, view to east - Salmon Creek Diversion Dam, Salmon Creek, Okanogan, Okanogan County, WA

  9. 6. General perspective view of Neawanna Creek Bridge, showing bushhammered, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. General perspective view of Neawanna Creek Bridge, showing bush-hammered, recessed panels in fascia wall - Neawanna Creek Bridge, Spanning Neawanna Creek at Milepoint 19.72 on U.S. 101 (Oregon Coast Highway), Seaside, Clatsop County, OR

  10. NITROGEN EXPORT FROM FORESTED WATERSHEDS IN THE OREGON COAST RANGE: THE ROLE OF N2-FIXING RED ALDER

    EPA Science Inventory

    Variations in plant community composition across the landscape can influence nutrient retention and loss at the watershed scale. A striking example of plant species influence is the role of N2-fixing red alder (Alnus rubra) in the biogeochemistry of Pacific Northwest forests. T...

  11. Anomalous Reactivity and Selectivity in the Intermolecular Diels-Alder Reactions of Multisubstituted Acyclic Dienes with Geometrical Isomers of Enals.

    PubMed

    Zhou, Jia-Hui; Cai, Sai-Hu; Xu, Yun-He; Loh, Teck-Peng

    2016-05-20

    A Lewis-acid catalyzed intermolecular Diels-Alder reaction between multisubstituted acyclic dienes and the E and Z isomers of α,β-enals was studied. It was found that the diene reacted selectively with the Z-isomer of the α,β-enal. PMID:27132468

  12. A Kinetic Study of the Diels-Alder Reaction. An Experiment Illustrating Simple Second-Order Reaction Kinetics.

    ERIC Educational Resources Information Center

    Silvestri, Michael G.; Dills, Charles E.

    1989-01-01

    Describes an organic chemistry experiment for teaching the basic concepts of chemical kinetics. Provides background information about first- and second-order reactions, experimental procedures of the Diels-Alder reaction between cyclopentadiene and dimethyl fumarate, and the experimental results. (YP)

  13. Microwave-Enhanced Organic Syntheses for the Undergraduate Laboratory: Diels-Alder Cycloaddition, Wittig Reaction, and Williamson Ether Synthesis

    ERIC Educational Resources Information Center

    Baar, Marsha R.; Falcone, Danielle; Gordon, Christopher

    2010-01-01

    Microwave heating enhanced the rate of three reactions typically performed in our undergraduate organic chemistry laboratory: a Diels-Alder cycloaddition, a Wittig salt formation, and a Williamson ether synthesis. Ninety-minute refluxes were shortened to 10 min using a laboratory-grade microwave oven. In addition, yields improved for the Wittig…

  14. The Preparation and Properties of Thermo-reversibly Cross-linked Rubber Via Diels-Alder Chemistry.

    PubMed

    Polgar, Lorenzo Massimo; van Duin, Martin; Picchioni, Francesco

    2016-01-01

    A method for using Diels Alder thermo-reversible chemistry as cross-linking tool for rubber products is demonstrated. In this work, a commercial ethylene-propylene rubber, grafted with maleic anhydride, is thermo-reversibly cross-linked in two steps. The pending anhydride moieties are first modified with furfurylamine to graft furan groups to the rubber backbone. These pendant furan groups are then cross-linked with a bis-maleimide via a Diels-Alder coupling reaction. Both reactions can be performed under a broad range of experimental conditions and can easily be applied on a large scale. The material properties of the resulting Diels-Alder cross-linked rubbers are similar to a peroxide-cured ethylene/propylene/diene rubber (EPDM) reference. The cross-links break at elevated temperatures (> 150 °C) via the retro-Diels-Alder reaction and can be reformed by thermal annealing at lower temperatures (50-70 °C). Reversibility of the system was proven with infrared spectroscopy, solubility tests and mechanical properties. Recyclability of the material was also shown in a practical way, i.e., by cutting a cross-linked sample into small parts and compression molding them into new samples displaying comparable mechanical properties, which is not possible for conventionally cross-linked rubbers. PMID:27583665

  15. Asymmetric synthesis of bicyclic dihydropyrans via organocatalytic inverse-electron-demand oxo-Diels-Alder reactions of enolizable aliphatic aldehydes.

    PubMed

    Li, Jun-Long; Yang, Kai-Chuan; Li, Yi; Li, Qiang; Zhu, Hong-Ping; Han, Bo; Peng, Cheng; Zhi, Yong-Gang; Gou, Xiao-Jun

    2016-08-23

    A highly enantioselective organocatalytic inverse-electron-demand oxo-Diels-Alder reaction involving aqueous acetaldehyde has been discovered. The reaction, in which cyclic enones serve as dienes in the presence of readily available secondary amine catalysts, allows facile construction of optically active bicyclic dihydropyrans. Other typical enolizable aliphatic aldehydes can also serve as competent dienophiles in the reaction. PMID:27436351

  16. Sorocenols G and H, Anti-MRSA Oxygen Heterocyclic Diels-Alder-type Adducts from Sorocea muriculata Roots

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bioassay-guided fractionation of a root extract of Sorocea muriculata led to the isolation and identification of two new oxygen heterocyclic Diels-Alder-type adducts, sorocenols G (1) and H (2), along with lupeol-3-(3'R-hydroxytetradecanoate) and oxyresveratrol. The structures of 1 and 2 were eluci...

  17. Underside from northeast. Waterville Bridge, Spanning Swatara Creek at ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Underside from northeast. - Waterville Bridge, Spanning Swatara Creek at Appalachian Trail (moved from Little Pine Creek at State Route 44, Waterville, Lycoming County), Green Point, Lebanon County, PA

  18. KANAB CREEK ROADLESS AREA, ARIZONA.

    USGS Publications Warehouse

    Billingsley, George H.; Ellis, Clarence E.

    1984-01-01

    On the basis of a mineral survey, the Kanab Creek Roadless Area in north-central Arizona has a probable mineral-resource potential for uranium and copper in four small areas around five collapse structures. Gypsum is abundant in layers along the canyon rim of Snake Gulch, but it is a fairly common mineral in the region outside the roadless area. There is little promise for the occurence of fossil fuels in the area. Studies of collapse structures in surrounding adjacent areas might reveal significant mineralization at depth, such as the recent discovery of the uranium ore body at depth in the Pigeon Pipe.

  19. 33 CFR 117.331 - Snake Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Snake Creek. 117.331 Section 117.331 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.331 Snake Creek. The draw of the Snake...

  20. 33 CFR 117.331 - Snake Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Snake Creek. 117.331 Section 117.331 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.331 Snake Creek. The draw of the Snake...

  1. 33 CFR 117.331 - Snake Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Snake Creek. 117.331 Section 117.331 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.331 Snake Creek. The draw of the Snake...

  2. 33 CFR 117.331 - Snake Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Snake Creek. 117.331 Section 117.331 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.331 Snake Creek. The draw of the Snake...

  3. 33 CFR 117.331 - Snake Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Snake Creek. 117.331 Section 117.331 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.331 Snake Creek. The draw of the Snake...

  4. TOXICITY PERSISTENCE IN PRICKLY PEAR CREEK, MONTANA

    EPA Science Inventory

    Instream toxicity tests using the larval fathead minnow Pimephales promelas and the cladoceran Ceriodaphnia reticulata were conducted on Prickly Pear Creek, Montana waters to study toxicity persistence in a stream. The toxicity source was Spring Creek, a tributary of Prickly Pear...

  5. 33 CFR 117.324 - Rice Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Rice Creek. 117.324 Section 117.324 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.324 Rice Creek. The CSX Railroad Swingbridge,...

  6. 33 CFR 117.324 - Rice Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Rice Creek. 117.324 Section 117.324 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.324 Rice Creek. The CSX Railroad Swingbridge,...

  7. 33 CFR 117.324 - Rice Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Rice Creek. 117.324 Section 117.324 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.324 Rice Creek. The CSX Railroad Swingbridge,...

  8. 33 CFR 117.324 - Rice Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Rice Creek. 117.324 Section 117.324 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.324 Rice Creek. The CSX Railroad Swingbridge,...

  9. 33 CFR 117.324 - Rice Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Rice Creek. 117.324 Section 117.324 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.324 Rice Creek. The CSX Railroad Swingbridge,...

  10. 33 CFR 117.1013 - Kinsale Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Kinsale Creek. 117.1013 Section 117.1013 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Virginia § 117.1013 Kinsale Creek. The draw of...

  11. 33 CFR 117.1013 - Kinsale Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Kinsale Creek. 117.1013 Section 117.1013 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Virginia § 117.1013 Kinsale Creek. The draw of...

  12. 33 CFR 117.1013 - Kinsale Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Kinsale Creek. 117.1013 Section 117.1013 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Virginia § 117.1013 Kinsale Creek. The draw of...

  13. 33 CFR 117.1013 - Kinsale Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Kinsale Creek. 117.1013 Section 117.1013 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Virginia § 117.1013 Kinsale Creek. The draw of...

  14. 33 CFR 117.543 - Bear Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Bear Creek. 117.543 Section 117.543 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.543 Bear Creek. (a) The draws of the...

  15. 33 CFR 117.543 - Bear Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Bear Creek. 117.543 Section 117.543 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.543 Bear Creek. (a) The draw of the...

  16. 33 CFR 117.543 - Bear Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Bear Creek. 117.543 Section 117.543 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.543 Bear Creek. (a) The draw of the...

  17. 33 CFR 117.543 - Bear Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Bear Creek. 117.543 Section 117.543 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.543 Bear Creek. (a) The draws of the...

  18. 33 CFR 117.543 - Bear Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Bear Creek. 117.543 Section 117.543 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.543 Bear Creek. (a) The draw of the...

  19. Pine Creek Ranch; Annual Report 2002.

    SciTech Connect

    Berry, Mark E.

    2003-02-01

    This report gives information about the following four objectives: OBJECTIVE 1--Gather scientific baseline information for monitoring purposes and to assist in the development of management plans for Pine Creek Ranch; OBJECTIVE 2--Complete and implement management plans; OBJECTIVE 3--Protect, manage and enhance the assets and resources of Pine Creek Ranch; and OBJECTIVE 4--Deliverables.

  20. 27 CFR 9.211 - Swan Creek.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Swan Creek. 9.211 Section... THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.211 Swan Creek. (a) Name. The name of the viticultural area described in this section is “Swan Creek”....

  1. 27 CFR 9.211 - Swan Creek.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Swan Creek. 9.211 Section... THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.211 Swan Creek. (a) Name. The name of the viticultural area described in this section is “Swan Creek”....

  2. 27 CFR 9.211 - Swan Creek.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Swan Creek. 9.211 Section... THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.211 Swan Creek. (a) Name. The name of the viticultural area described in this section is “Swan Creek”....

  3. 27 CFR 9.211 - Swan Creek.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Swan Creek. 9.211 Section... THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.211 Swan Creek. (a) Name. The name of the viticultural area described in this section is “Swan Creek”....

  4. 27 CFR 9.211 - Swan Creek.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Swan Creek. 9.211 Section... THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.211 Swan Creek. (a) Name. The name of the viticultural area described in this section is “Swan Creek”....

  5. 33 CFR 117.335 - Taylor Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Taylor Creek. 117.335 Section 117.335 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.335 Taylor Creek. The draw of US441 bridge, mile...

  6. 33 CFR 117.335 - Taylor Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Taylor Creek. 117.335 Section 117.335 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.335 Taylor Creek. The draw of US441 bridge, mile...

  7. 33 CFR 117.917 - Battery Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Battery Creek. 117.917 Section 117.917 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements South Carolina § 117.917 Battery Creek. The draw...

  8. 33 CFR 117.917 - Battery Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Battery Creek. 117.917 Section 117.917 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements South Carolina § 117.917 Battery Creek. The draw...

  9. 33 CFR 117.917 - Battery Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Battery Creek. 117.917 Section 117.917 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements South Carolina § 117.917 Battery Creek. The draw...

  10. 33 CFR 117.917 - Battery Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Battery Creek. 117.917 Section 117.917 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements South Carolina § 117.917 Battery Creek. The draw...

  11. 33 CFR 117.917 - Battery Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Battery Creek. 117.917 Section 117.917 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements South Carolina § 117.917 Battery Creek. The draw...

  12. 33 CFR 117.809 - Tonawanda Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Tonawanda Creek. 117.809 Section 117.809 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New York § 117.809 Tonawanda Creek. The draw of...

  13. 33 CFR 117.813 - Wappinger Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Wappinger Creek. 117.813 Section 117.813 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New York § 117.813 Wappinger Creek. The draw of...

  14. 33 CFR 117.813 - Wappinger Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Wappinger Creek. 117.813 Section 117.813 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New York § 117.813 Wappinger Creek. The draw of...

  15. 33 CFR 117.809 - Tonawanda Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Tonawanda Creek. 117.809 Section 117.809 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New York § 117.809 Tonawanda Creek. The draw of...

  16. 33 CFR 117.841 - Smith Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Smith Creek. 117.841 Section 117.841 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements North Carolina § 117.841 Smith Creek. The draw of the...

  17. 33 CFR 117.841 - Smith Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Smith Creek. 117.841 Section 117.841 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements North Carolina § 117.841 Smith Creek. The draw of the...

  18. 33 CFR 117.841 - Smith Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Smith Creek. 117.841 Section 117.841 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements North Carolina § 117.841 Smith Creek. The draw of the...

  19. 33 CFR 117.841 - Smith Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Smith Creek. 117.841 Section 117.841 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements North Carolina § 117.841 Smith Creek. The draw of the...

  20. 33 CFR 117.841 - Smith Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Smith Creek. 117.841 Section 117.841 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements North Carolina § 117.841 Smith Creek. The draw of the...

  1. Diversity-Oriented Approaches to Polycyclics and Bioinspired Molecules via the Diels-Alder Strategy: Green Chemistry, Synthetic Economy, and Beyond.

    PubMed

    Kotha, Sambasivarao; Chavan, Arjun S; Goyal, Deepti

    2015-05-11

    We describe diverse approaches to various dienes and their utilization in the Diels-Alder reaction to produce a variety of polycycles. The dienes covered here are prepared by simple alkylation reaction or via the Claisen rearrangement or by enyne metathesis of alkyne or enyne building blocks. Here, we have also included the Diels-Alder chemistry of dendralenes, a higher analog of cross-conjugated dienes. The present article is inclusive of o-xylylene derivatives that are generated in situ starting with benzosultine or benzosulfone derivatives. The Diels-Alder reaction of these dienes with various dienophiles gave diverse polycyclic systems and biologically important targets. PMID:25875156

  2. The impact of a pulsing groundwater table on greenhouse gas emissions in riparian grey alder stands.

    PubMed

    Mander, Ülo; Maddison, Martin; Soosaar, Kaido; Teemusk, Alar; Kanal, Arno; Uri, Veiko; Truu, Jaak

    2015-02-01

    Floods control greenhouse gas (GHG) emissions in floodplains; however, there is a lack of data on the impact of short-term events on emissions. We studied the short-term effect of changing groundwater (GW) depth on the emission of (GHG) carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) in two riparian grey alder (Alnus incana) stands of different age in Kambja, southern Estonia, using the opaque static chamber (five replicates in each site) and gas chromatography methods. The average carbon and total nitrogen content in the soil of the old alder (OA) stand was significantly higher than in the young alder (YA) stand. In both stands, one part was chosen for water table manipulation (Manip) and another remained unchanged with a stable and deeper GW table. Groundwater table manipulation (flooding) significantly increases CH4 emission (average: YA-Dry 468, YA-Manip 8,374, OA-Dry 468, OA-Manip 4,187 μg C m(-2) h(-1)) and decreases both CO2 (average: OA-Dry 138, OA-Manip 80 mg C m(-2) h(-1)) and N2O emissions (average: OA-Dry 23.1, OA-Manip 11.8 μg N m(-2) h(-1)) in OA sites. There was no significant difference in CO2 and CH4 emissions between the OA and YA sites, whereas in OA sites with higher N concentration in the soil, the N2O emission was significantly higher than at the YA sites. The relative CO2 and CH4 emissions (the soil C stock-related share of gaseous losses) were higher in manipulated plots showing the highest values in the YA-Manip plot (0.03 and 0.0030 % C day(-1), respectively). The soil N stock-related N2O emission was very low achieving 0.000019 % N day(-1) in the OA-Dry plot. Methane emission shows a negative correlation with GW, whereas the 20 cm depth is a significant limit below which most of the produced CH4 is oxidized. In terms of CO2 and N2O, the deeper GW table significantly increases emission. In riparian zones of headwater streams, the short-term floods (e.g. those driven by extreme climate events) may significantly enhance

  3. Buck Creek River Flow Analysis

    NASA Astrophysics Data System (ADS)

    Dhanapala, Yasas; George, Elizabeth; Ritter, John

    2009-04-01

    Buck Creek flowing through Springfield Ohio has a number of low-head dams currently in place that cause safety issues and sometimes make it impossible for recreational boaters to pass through. The safety issues include the back eddies created by the dams that are known as drowning machines and the hydraulic jumps. In this study we are modeling the flow of Buck Creek using topographical and flow data provided by the Geology Department of Wittenberg University. The flow is analyzed using Hydraulic Engineering Center - River Analysis System software (HEC-RAS). As the first step a model of the river near Snyder Park has been created with the current structure in place for validation purposes. Afterwards the low-head dam is replaced with four drop structures with V-notch overflow gates. The river bed is altered to reflect plunge pools after each drop structure. This analysis will provide insight to how the flow is going to behave after the changes are made. In addition a sediment transport analysis is also being conducted to provide information about the stability of these structures.

  4. Poly /Diels-Alder/ matrix resins. [high temperature resistant graphite reinforced composites

    NASA Technical Reports Server (NTRS)

    Jones, R. J.; Orell, M. K.; Sheppard, C. H.; Vaughan, R. W.

    1977-01-01

    A poly (Diels-Alder) (PDA) resin approach was investigated as a means to achieve autoclavability of high-temperature resistant resin/fiber composites under mild fabrication conditions. The results of the study were highly promising and program objectives were achieved. Low-void content Type A-S graphite reinforced composites were autoclave fabricated from a PDA resin/fiber prepreg prepared from an acetone:methanol:dioxane varnish. Autoclave conditions were 400 F and 100 psi for up to two hours duration. After postcure at temperatures up to 600 F, the composites demonstrated high initial mechanical properties at temperatures up to 550 F. The results from isothermal aging studies in air for 1000 hours indicated potential for long-term (over 1000 hours) use at 500 F and shorter-term use at 550 F.

  5. Characterization of vanadium ion uptake in sulfonated diels alder poly(phenylene) membranes

    DOE PAGESBeta

    Lawton, Jamie; Jones, Amanda; Tang, Zhijiang; Lindsey, Melanie; Zawodzinski, Thomas A

    2015-11-28

    Sulfonated diels alder poly(phenylene) (SDAPP), alternative aromatic hydrocarbon membranes for vanadium redox flow batteries (VRFBs) are characterized using electron paramagnetic resonance (EPR). Membranes soaked in sulfuric acid and vanadyl sulfate are analyzed to determine the membrane environment in which the vanadyl ion (VO2+) diffuses in the membranes. These results are compared to Nafion 117 membranes. In contrast to Nafion, the VO2+ in SDAPP membranes exists in two different environments. The results of analysis of rotational diffusion determined from fits the EPR spectral lineshapes in comparison with previously reported permeation studies and measurements of partitioning functions reported here suggest that themore » diffusion pathways in SDAPP are very different than in Nafion.« less

  6. Economic considerations in establishing European alder in herbaceous cover on surface-mined land

    SciTech Connect

    Ringe, J.M.; Graves, D.H.

    1985-12-09

    Herbicides are a practical tool for selectively controlling vegetative competition during tree seedling establishment. A study to investigate the effects of eight herbicide treatments on the survival and height growth of European alder (Alnus glutinosa) seedlings established in herbaceous cover indicated a positive treatment effect, but very little difference between the herbicide treatments themselves. Since the costs of the herbicides varied considerably, similar results could be obtained using the different herbicides, but at substantially different costs. Biological data were combined with the economic data to derive a modified benefit/cost ratio. This ratio facilitates herbicide treatment choice by comparing the amount of added survival or growth obtained per dollar spent on herbicides. 5 references, 6 tables.

  7. Description and identification of Alnus acuminata ectomycorrhizae from Argentinean alder stands.

    PubMed

    Pritsch, Karin; Becerra, Alejandra; Põlme, Sergei; Tedersoo, Leho; Schloter, Michael; Agerer, Reinhard

    2010-01-01

    The objective of this study was to describe the morphological and anatomical features of five unidentified ectomycorrhizal types of Alnus acuminata and to complement their identification based on ITS-rDNA sequence analysis. The combined approach of morphotyping and sequence analysis based on ITS sequence comparison with sequences contained in GenBank and the UNITE database let us assign three of the five field-collected ectomycorrhiza morphotypes to the tomentella-thelephora lineage that closely matched European and North American species. The sequencing results within Tomentella point toward alder specific clades within T. sublilacina, T. ellisii and T. stuposa sensu lato. The two other EcM morphotypes matched Lactarius omphaliiformis and a Russula sp. Better focused, concomitant fruit body surveys are needed for accurate identification of South American ectomycorrhizal fungi because of the evidence of cryptic speciation in both agaricoid and resupinate mycobionts. PMID:20943556

  8. Kondrat'eva ligation: Diels-Alder-based irreversible reaction for bioconjugation.

    PubMed

    Jouanno, Laurie-Anne; Chevalier, Arnaud; Sekkat, Nawal; Perzo, Nicolas; Castel, Hélène; Romieu, Anthony; Lange, Norbert; Sabot, Cyrille; Renard, Pierre-Yves

    2014-11-01

    Diversification of existing chemoselective ligations is required to efficiently access complex and well-defined biomolecular assemblies with unique and valuable properties. The development and bioconjugation applications of a novel Diels-Alder-based irreversible site-specific ligation are reported. The strategy is based on a Kondrat'eva cycloaddition between bioinert and readily functionalizable 5-alkoxyoxazoles and maleimides that readily react together under mild and easily tunable reaction conditions to afford a fully stable pyridine scaffold. The potential of this novel bioconjugation is demonstrated through the preparation of fluorescent conjugates of biomolecules and a novel Förster resonance energy transfer (FRET)-based probe suitable for the in vivo detection and imaging of urokinase-like plasminogen activator (uPA), which is a key protease involved in cancer invasion and metastasis. PMID:25346140

  9. A mechanochemical study of the effects of compression on a Diels-Alder reaction.

    PubMed

    Jha, Sanjiv K; Brown, Katie; Todde, Guido; Subramanian, Gopinath

    2016-08-21

    We examine the effects of compressive external forces on the mechanisms of the parent Diels-Alder (DA) reaction between butadiene and ethylene. Reaction pathways and transition states were calculated using the nudged elastic band method within a mechanochemical framework at the CASSCF(6,6)/6-31G**, as well as the B3LYP/6-311++G** levels of theory. Our results suggest that compressive hydrostatic pressure lowers the energy barrier for the parent DA reaction while suppressing the undesirable side reaction, thereby leading to a direct increase in the yield of cyclohexene. Compressive pressure also increases the exothermicity of the parent DA reaction, which would lead to increased temperatures in a reaction vessel and thereby indirectly increase the yield of cyclohexene. Our estimates indicate that the compression used in our study corresponds to a range of 68 MPa-1410 MPa. PMID:27544105

  10. Dynamics of methane production, sulfate reduction, and denitrification in a permanently waterlogged alder swamp

    SciTech Connect

    Westermann, P.; Ahring, B.K.

    1987-10-01

    The dynamics of sulfate reduction, methane production, and denitrification were investigated in a permanently waterlogged alder swamp. Molybdate, an inhibitor of sulfate reduction, stimulated methane production in soil slurries, thus suggesting competition for common substrates between sulfate-reducing and methane-producing bacteria. Acetate, hydrogen, and methanol were found to stimulate both sulfate reduction and methane production, while trimethylamine mainly stimulated methane production. Nitrate addition reduced both methane production and sulfate reduction, either as a consequence of competition of poisoning of the bacteria. Sulfate-reducing bacteria were only slightly limited by the availability of electron acceptors, while denitrifying bacteria were seriously limited by low nitrate concentrations. Arrhenius plots of the three processes revealed different responses to temperature changes in the slurries. Methane production was most sensitive to temperature changes, followed by denitrification and sulfate reduction. No significant differences between slope patterns were observed when comparing summer and winter measurements, indicating similar populations regarding temperature responses.

  11. Characterization of vanadium ion uptake in sulfonated diels alder poly(phenylene) membranes

    SciTech Connect

    Lawton, Jamie; Jones, Amanda; Tang, Zhijiang; Lindsey, Melanie; Zawodzinski, Thomas A

    2015-11-28

    Sulfonated diels alder poly(phenylene) (SDAPP), alternative aromatic hydrocarbon membranes for vanadium redox flow batteries (VRFBs) are characterized using electron paramagnetic resonance (EPR). Membranes soaked in sulfuric acid and vanadyl sulfate are analyzed to determine the membrane environment in which the vanadyl ion (VO2+) diffuses in the membranes. These results are compared to Nafion 117 membranes. In contrast to Nafion, the VO2+ in SDAPP membranes exists in two different environments. The results of analysis of rotational diffusion determined from fits the EPR spectral lineshapes in comparison with previously reported permeation studies and measurements of partitioning functions reported here suggest that the diffusion pathways in SDAPP are very different than in Nafion.

  12. Click and Patterned Functionalization of Graphene by Diels-Alder Reaction.

    PubMed

    Li, Jing; Li, Meng; Zhou, Li-Li; Lang, Shuang-Yan; Lu, Hai-Yan; Wang, Dong; Chen, Chuan-Feng; Wan, Li-Jun

    2016-06-22

    Chemical functionalization is a promising approach to controllably manipulate the characteristics of graphene. Here, we designed cis-dienes, featuring two dihydronaphthalene backbones, to decorate a graphene surface via Diels-Alder (DA) click reaction. The installation of a diene moiety into a nonplanar molecular structure to form cis-conformation enables a rapid (∼5 min) DA reaction between graphene and diene groups. Patterned graphene of sub-micrometer resolution can be obtained by easily soaking poly(methyl methacrylate)-masked graphene in solution of hydroxyl-substituted cis-diene at room temperature. The functionalization degree can be further controlled by carrying out the reaction at higher temperature. The present result gives important insight into the effect of molecular conformation on the graphene functionalization process, and provides an effective and facile method for graphene functionalization. PMID:27264112

  13. Total synthesis of (+)-gelsemine via an organocatalytic Diels-Alder approach.

    PubMed

    Chen, Xiaoming; Duan, Shengguo; Tao, Cheng; Zhai, Hongbin; Qiu, Fayang G

    2015-01-01

    The structurally complex alkaloid gelsemine was previously thought to have no significant biological activities, but a recent study has shown that it has potent and specific antinociception in chronic pain. While this molecule has attracted significant interests from the synthetic community, an efficient synthetic strategy is still the goal of many synthetic chemists. Here we report the asymmetric total synthesis of (+)-gelsemine, including a highly diastereoselective and enantioselective organocatalytic Diels-Alder reaction, an efficient intramolecular trans-annular aldol condensation furnishing the prolidine ring and establishing the configuration of the C20 quaternary carbon stereochemical centre. The entire gelsemine skeleton was constructed through a late-stage intramolecular SN2 substitution. The enantiomeric excess of this total synthesis is over 99%, and the overall yield is around 5%. PMID:25995149

  14. Total synthesis of (+)-gelsemine via an organocatalytic Diels–Alder approach

    PubMed Central

    Chen, Xiaoming; Duan, Shengguo; Tao, Cheng; Zhai, Hongbin; Qiu, Fayang G.

    2015-01-01

    The structurally complex alkaloid gelsemine was previously thought to have no significant biological activities, but a recent study has shown that it has potent and specific antinociception in chronic pain. While this molecule has attracted significant interests from the synthetic community, an efficient synthetic strategy is still the goal of many synthetic chemists. Here we report the asymmetric total synthesis of (+)-gelsemine, including a highly diastereoselective and enantioselective organocatalytic Diels–Alder reaction, an efficient intramolecular trans-annular aldol condensation furnishing the prolidine ring and establishing the configuration of the C20 quaternary carbon stereochemical centre. The entire gelsemine skeleton was constructed through a late-stage intramolecular SN2 substitution. The enantiomeric excess of this total synthesis is over 99%, and the overall yield is around 5%. PMID:25995149

  15. Synthesis of tetrasubstituted 1-silyloxy-3-aminobutadienes and chemistry beyond Diels–Alder reactions

    PubMed Central

    Li, Xijian; Peng, Siyu; Li, Li; Huang, Yong

    2015-01-01

    Electron-rich dienes have revolutionized the synthesis of complex compounds since the discovery of the legendary Diels–Alder cycloaddition reaction. This highly efficient bond-forming process has served as a fundamental strategy to assemble many structurally formidable molecules. Amino silyloxy butadienes are arguably the most reactive diene species that are isolable and bottleable. Since the pioneering discovery by Rawal, 1-amino-3-silyloxybutadienes have been found to undergo cycloaddition reactions with unparalleled mildness, leading to significant advances in both asymmetric catalysis and total synthesis of biologically active natural products. In sharp contrast, this class of highly electron-rich conjugated olefins has not been studied in non-cycloaddition reactions. Here we report a simple synthesis of tetrasubstituted 1-silyloxy-3-aminobutadienes, a complementarily substituted Rawal's diene. This family of molecules is found to undergo a series of intriguing chemical transformations orthogonal to cycloaddition reactions. Structurally diverse polysubstituted ring architectures are established in one step from these dienes. PMID:25898310

  16. Dynamics of Methane Production, Sulfate Reduction, and Denitrification in a Permanently Waterlogged Alder Swamp

    PubMed Central

    Westermann, Peter; Ahring, Birgitte Kiær

    1987-01-01

    The dynamics of sulfate reduction, methane production, and denitrification were investigated in a permanently waterlogged alder swamp. Molybdate, an inhibitor of sulfate reduction, stimulated methane production in soil slurries, thus suggesting competition for common substrates between sulfate-reducing and methane-producing bacteria. Acetate, hydrogen, and methanol were found to stimulate both sulfate reduction and methane production, while trimethylamine mainly stimulated methane production. Nitrate addition reduced both methane production and sulfate reduction, either as a consequence of competition or poisoning of the bacteria. Sulfate-reducing bacteria were only slightly limited by the availability of electron acceptors, while denitrifying bacteria were seriously limited by low nitrate concentrations. Arrhenius plots of the three processes revealed different responses to temperature changes in the slurries. Methane production was most sensitive to temperature changes, followed by denitrification and sulfate reduction. No significant differences between slope patterns were observed when comparing summer and winter measurements, indicating similar populations regarding temperature responses. PMID:16347472

  17. Flood discharges and hydraulics near the mouths of Wolf Creek, Craig Branch, Manns Creek, Dunloup Creek, and Mill Creek in the New River Gorge National River, West Virginia

    USGS Publications Warehouse

    Wiley, J.B.

    1994-01-01

    The U.S. Geological Survey, in cooperation with the National Park Service, studied the frequency and magnitude of flooding near the mouths of five tributaries to the New River in the New River Gorge National River. The 100-year peak discharge at each tributary was determined from regional frequency equations. The 100-year discharge at Wolf Creek, Craig Branch, Manns Creek, Dunloup Creek, and Mill Creek was 3,400 cubic feet per second, 640 cubic feet per second, 8,200 cubic feet per second, 7,100 cubic feet per second, and 9,400 cubic feet per second, respectively. Flood elevations for each tributary were determined by application of a steady-state, one-dimensional flow model. Manning's roughness coefficients for the stream channels ranged from 0.040 to 0.100. Bridges that would be unable to contain the 100-year flood within the bridge opening included: the State Highway 82 bridge on Wolf Creek, the second Fayette County Highway 25 bridge upstream from the confluence with New River on Dunloup Creek, and an abandoned log bridge on Mill Creek.

  18. 77 FR 10960 - Drawbridge Operation Regulation; Snake Creek, Islamorada, FL

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-24

    ... SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulation; Snake Creek, Islamorada, FL AGENCY... of Snake Creek Bridge, mile 0.5, across Snake Creek, in Islamorada, Florida. The regulation is set... Sheriff's Office has requested a temporary modification to the operating schedule of Snake Creek Bridge...

  19. 1. EXTERIOR OVERVIEW OF NORTH END OF RUSH CREEK POWERHOUSE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. EXTERIOR OVERVIEW OF NORTH END OF RUSH CREEK POWERHOUSE RESIDENTIAL COMPLEX SHOWING BUILDING 108 AT PHOTO RIGHT AND BUILDING 105 AT PHOTO CENTER BEHIND TREE. RUSH CREEK POWERHOUSE IS PARTIALLY VISIBLE AT EXTREME PHOTO LEFT). VIEW TO WEST. - Rush Creek Hydroelectric System, Clubhouse Cottage, Rush Creek, June Lake, Mono County, CA

  20. 1. EXTERIOR OVERVIEW OF SOUTH END OF RUSH CREEK POWERHOUSE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. EXTERIOR OVERVIEW OF SOUTH END OF RUSH CREEK POWERHOUSE RESIDENTIAL COMPLEX SHOWING THE RUSH CREEK POWERHOUSE AT PHOTO RIGHT (TAILRACE IN FOREGROUND), BUILDING 106 NEXT TO THE POWERHOUSE AT PHOTO LEFT CENTER, AND BUILDING 103 AT UPPER PHOTO LEFT ABOVE AND BEHIND BUILDING 106. VIEW TO SOUTH. - Rush Creek Hydroelectric System, Worker Cottage, Rush Creek, June Lake, Mono County, CA

  1. 3. OVERVIEW CONTEXTUAL VIEW OF BIG CREEK NO. 3 COMPLEX ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. OVERVIEW CONTEXTUAL VIEW OF BIG CREEK NO. 3 COMPLEX SHOWING SWITCHRACKS AND SUPPORT BUILDINGS TO PHOTO RIGHT OF POWERHOUSE, SAN JOAQUIN RIVER FLOWING IN PHOTO CENTER TO LOWER RIGHT, AND PENSTOCKS AND STANDPIPES IN BACKGROUND ABOVE POWERHOUSE. VIEW TO EAST. - Big Creek Hydroelectric System, Powerhouse 3 Penstock Standpipes, Big Creek, Big Creek, Fresno County, CA

  2. 2. CONTEMPORARY PHOTOGRAPH OF BIG CREEK POWERHOUSE NO. 3 TAKEN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. CONTEMPORARY PHOTOGRAPH OF BIG CREEK POWERHOUSE NO. 3 TAKEN FROM SAME ANGLE AS CA-167-X-1. THREE ORIGINAL PENSTOCKS PLUS FOURTH AND FIFTH PENSTOCKS (VISIBLE TO LEFT OF ORIGINAL THREE), AND THREE ORIGINAL STANDPIPES COUPLED TO FOURTH STANDPIPE SHOWN BEHIND AND ABOVE POWERHOUSE BUILDING. VIEW TO NORTHEAST. - Big Creek Hydroelectric System, Powerhouse 3 Penstock Standpipes, Big Creek, Big Creek, Fresno County, CA

  3. Panther Creek, Idaho, Habitat Rehabilitation, Final Report.

    SciTech Connect

    Reiser, Dudley W.

    1986-01-01

    The purpose of the project was to achieve full chinook salmon and steelhead trout production in the Panther Creek, Idaho, basin. Plans were developed to eliminate the sources of toxic effluent entering Panther Creek. Operation of a cobalt-copper mine since the 1930's has resulted in acid, metal-bearing drainage entering the watershed from underground workings and tailings piles. The report discusses plans for eliminating and/or treating the effluent to rehabilitate the water quality of Panther Creek and allow the reestablishment of salmon and trout spawning runs. (ACR)

  4. Jacobs Creek bioaccumulation report, 1979 and 1980

    SciTech Connect

    Koch, L.M.; Harned, R.D.

    1981-04-01

    In conjunction with TVA's monitoring of biota in Jacobs Creek (TVA 1981), which receives fly ash pond effluent from Paradise Steam-Electric Plant and is a tributary to the Green River, fish flesh samples were collected for metals analyses. Following pH adjustment of the Paradise fly ash pond, it was anticipated aquatic communities in the lower portion of Jacobs Creek would begin to recover. Development of a fishery in this area was expected as recovery progressed. A potential avenue for metals transfer to humans would be established through consumption of fish from Jacobs Creek. Therefore, concentrations of metals in fish flesh were analyzed.

  5. Flood of August 27-28, 1977, West Cache Creek and Blue Beaver Creek, southwestern Oklahoma

    USGS Publications Warehouse

    Corley, Robert K.; Huntzinger, Thomas L.

    1979-01-01

    This report documents a major storm which occurred August 27-28, 1977, in southwest Oklahoma near the communities of Cache and Faxon, OK. Blue Beaver Creek and West Cache Creek and their tributaries experienced extensive flooding that caused an estimated $1 million in damages. Reported rainfall amounts of 8 to 12 inches in 6 hours indicate the storm had a frequency in excess of the 100-year rainfall. Peak discharges on Blue Beaver Creek near Cache and West Cache Creek near Faxon were 13,500 cubic feet per second and 45,700 cubic feet per second respectively. The estimated flood frequency was in excess of 100 years on Blue Beaver Creek and in excess of 50 years on West Cache Creek. Unit runoff on small basins were in excess of 2000 cubic feet per second per square mile. Surveyed highwater marks were used to map the flooded area. (USGS)

  6. Steel Creek wildlife: L-Lake/Steel Creek Biological Monitoring Program, January 1986--December 1987

    SciTech Connect

    Giffin, M.A.; Patterson, K.K.

    1988-03-01

    Reptile and amphibian populations in Steel Creek below L-Lake were assessed in monthly or quarterly sampling programs. Thirty-eight species of reptiles or amphibians were collected during 1987 in the Steel Creek corridor below the L-Lake impoundment, and in the delta and channel. Juvenile turtles and alligators, and larval amphibians were observed or collected during the study, indicating continued reproduction in Steel Creek. The reptile and amphibian populations in Steel Creek show no indication of any effect due to the impoundment of the lake or the operation of L-Reactor. Waterfowl and associated birds in Steel Creek below L-Lake were observed, in conjunction with other sampling programs, during winter--spring and fall--winter migrations. Nine species of waterfowl and five species of associated birds were observed in 1987 in the Steel Creek corridor below the L-Lake impoundment and in the delta and channel.

  7. Toms Creek IGCC Demonstration Project

    SciTech Connect

    Virr, M.J.

    1992-01-01

    The Toms Creek Integrated Gasification Combined Cycle (IGCC) Demonstration Project was selected by DOE in September 1991 to participate in Round Four of the Clean Coal Technology Demonstration Program. The project will demonstrate a simplified IGCC process consisting of an air-blown, fluidized-bed gasifier (Tampella U-Gas), a gas cooler/steam generator, and a hot gas cleanup system in combination with a gas turbine modified for use with a low-Btu content fuel and a conventional steam bottoming cycle. The demonstration plant will be located at the Toms Creek coal mine near Coeburn, Wise County, Virginia. Participants in the project are Tampella Power Corporation and Coastal Power Production Company. The plant will use 430 tons per day of locally mined bituminous coal to produce 55 MW of power from the gasification section of the project. A modern pulverized coal fired unit will be located adjacent to the Demonstration Project producing an additional 150 MW. A total 190 MW of power will be delivered to the electric grid at the completion of the project. In addition, 50,000 pounds per hour of steam will be exported to be used in the nearby coal preparation plant. Dolomite is used for in-bed gasifier sulfur capture and downs cleanup is accomplished in a fluidized-bed of regenerative zinc titanate. Particulate clean-up, before the gas turbine, will be performed by high temperature candle filters (1020[degree]F). The demonstration plant heat rate is estimated to be 8,700 Btu/kWh. The design of the project goes through mid 1995, with site construction activities commencing late in 1995 and leading to commissioning and start-up by the end of 1997. This is followed by a three year demonstration period.

  8. Toms Creek IGCC Demonstration Project

    SciTech Connect

    Virr, M.J.

    1992-11-01

    The Toms Creek Integrated Gasification Combined Cycle (IGCC) Demonstration Project was selected by DOE in September 1991 to participate in Round Four of the Clean Coal Technology Demonstration Program. The project will demonstrate a simplified IGCC process consisting of an air-blown, fluidized-bed gasifier (Tampella U-Gas), a gas cooler/steam generator, and a hot gas cleanup system in combination with a gas turbine modified for use with a low-Btu content fuel and a conventional steam bottoming cycle. The demonstration plant will be located at the Toms Creek coal mine near Coeburn, Wise County, Virginia. Participants in the project are Tampella Power Corporation and Coastal Power Production Company. The plant will use 430 tons per day of locally mined bituminous coal to produce 55 MW of power from the gasification section of the project. A modern pulverized coal fired unit will be located adjacent to the Demonstration Project producing an additional 150 MW. A total 190 MW of power will be delivered to the electric grid at the completion of the project. In addition, 50,000 pounds per hour of steam will be exported to be used in the nearby coal preparation plant. Dolomite is used for in-bed gasifier sulfur capture and downs cleanup is accomplished in a fluidized-bed of regenerative zinc titanate. Particulate clean-up, before the gas turbine, will be performed by high temperature candle filters (1020{degree}F). The demonstration plant heat rate is estimated to be 8,700 Btu/kWh. The design of the project goes through mid 1995, with site construction activities commencing late in 1995 and leading to commissioning and start-up by the end of 1997. This is followed by a three year demonstration period.

  9. 78 FR 5798 - Grouse Creek Wind Park, LLC, Grouse Creek Wind Park II, LLC; Notice of Petition for Enforcement

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-28

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Grouse Creek Wind Park, LLC, Grouse Creek Wind Park II, LLC; Notice of... Utility Regulatory Policies Act of 1978 (PURPA), Grouse Creek Wind Park, LLC and Grouse Creek Wind Park...

  10. Steel Creek fish, L-Lake/Steel Creek Biological Monitoring Program, January 1986--December 1991

    SciTech Connect

    Sayers, R.E. Jr.; Mealing, H.G. III

    1992-04-01

    The Savannah River Site (SRS) encompasses 300 sq mi of the Atlantic Coastal plain in west-central South Carolina. The Savannah River forms the western boundary of the site. Five major tributaries of the Savannah River -- Upper Three Runs Creek, Four Mile Creek, Pen Branch, Steel Creek, and Lower Three Runs Creek -- drain the site. All but Upper Three Runs Creek receive, or in the past received, thermal effluents from nuclear production reactors. In 1985, L Lake, a 400-hectare cooling reservoir, was built on the upper reaches of Steel Creek to receive effluent from the restart of L-Reactor, and protect the lower reaches from thermal impacts. The lake has an average width of approximately 600 m and extends along the Steel Creek valley approximately 7000 m from the dam to the headwaters. Water level is maintained at a normal pool elevation of 58 m above mean sea level by overflow into a vertical intake tower that has multilevel discharge gates. The intake tower is connected to a horizontal conduit that passes through the dam and releases water into Steel Creek. The Steel Creek Biological Monitoring Program was designed to meet environmental regulatory requirements associated with the restart of L-Reactor and complements the Biological Monitoring Program for L Lake. This extensive program was implemented to address portions of Section 316(a) of the Clean Water Act. The Department of Energy (DOE) must demonstrate that the operation of L-Reactor will not significantly alter the established aquatic ecosystems.

  11. 33 CFR 117.929 - Durham Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... OPERATION REGULATIONS Specific Requirements South Carolina § 117.929 Durham Creek. The removable span of the... Charleston of an emergency in the Bushy Park Reservoir, the span shall be removed as soon as possible...

  12. 33 CFR 117.929 - Durham Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... OPERATION REGULATIONS Specific Requirements South Carolina § 117.929 Durham Creek. The removable span of the... Charleston of an emergency in the Bushy Park Reservoir, the span shall be removed as soon as possible...

  13. 33 CFR 117.929 - Durham Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... OPERATION REGULATIONS Specific Requirements South Carolina § 117.929 Durham Creek. The removable span of the... Charleston of an emergency in the Bushy Park Reservoir, the span shall be removed as soon as possible...

  14. 33 CFR 117.929 - Durham Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... OPERATION REGULATIONS Specific Requirements South Carolina § 117.929 Durham Creek. The removable span of the... Charleston of an emergency in the Bushy Park Reservoir, the span shall be removed as soon as possible...

  15. Dry Creek Wilderness study area, Arkansas

    SciTech Connect

    Haley, B.R.; Stroud, R.B.

    1984-01-01

    A mineral evaluation study of the Dry Creek Wilderness Study Area indicated that the area has a probable resource potential for natural gas and little promise for the occurrence of other mineral commodities.

  16. Diels-Alder Trapping of Photochemically Generated Dienes with Acrylic Esters: A Novel Approach to Photocured Polymer Film Development

    NASA Technical Reports Server (NTRS)

    Ilhan, Faysal; Tyson, Daniel S.; Smith, Deedee; Meador, Mary Ann; Meador, Michael A.

    2004-01-01

    Diels-Alder cycloadditions have often been utilized in polymer synthesis as an alternative to condensation reactions. In our earlier efforts, we developed a new method for the preparation of linear aromatic polyimides, which employs o-quionodimethanes (o-QDMs), generated by a well-known photochemical reaction: the photoenolization of o-methylphenyl ketones. Photolysis of o-methylbenzophenone 1 produces hydroxy-o-quino- diemthane 2, which can be trapped with dienophiles, such as dimethyl acetylenedicarboxylate, to efficiently yield the corresponding cycloadduct (Scheme 1). Here we extend this approach to a novel photocuring process for development of polymer films. We synthesized a series of molecules with multi o-mehtylphenyl ketone functionalities. We further investigated these molecules as photoreactive monomers to obtain polyester films through Diels-Alder cycloadditions.

  17. Exploring Reaction Mechanism on Generalized Force Modified Potential Energy Surfaces (G-FMPES) for Diels-Alder Reaction

    NASA Astrophysics Data System (ADS)

    Jha, Sanjiv; Brown, Katie; Subramanian, Gopinath

    We apply a recent formulation for searching minimum energy reaction path (MERP) and saddle point to atomic systems subjected to an external force. We demonstrate the effect of a loading modality resembling hydrostatic pressure on the trans to cis conformational change of 1,3-butadiene, and the simplest Diels-Alder reaction between ethylene and 1,3-butadiene. The calculated MERP and saddle points on the generalized force modified potential energy surface (G-FMPES) are compared with the corresponding quantities on an unmodified potential energy surface. Our study is performed using electronic structure calculations at the HF/6-31G** level as implemented in the AIMS-MOLPRO code. Our calculations suggest that the added compressive pressure lowers the energy of cis butadiene. The activation energy barrier for the concerted Diels-Alder reaction is found to decrease progressively with increasing compressive pressure.

  18. Wolf Creek Generating Station containment model

    SciTech Connect

    Nguyen, D.H.; Neises, G.J.; Howard, M.L.

    1995-12-31

    This paper presents a CONTEMPT-LT/28 containment model that has been developed by Wolf Creek Nuclear Operating Corporation (WCNOC) to predict containment pressure and temperature behavior during the postulated events at Wolf Creek Generating Station (WCGS). The model has been validated using data provided in the WCGS Updated Safety Analysis Report (USAR). CONTEMPT-LT/28 model has been used extensively at WCGS to support plant operations, and recently, to support its 4.5% thermal power uprate project.

  19. The Blacktail Creek Tuff: an analytical and experimental study of rhyolites from the Heise volcanic field, Yellowstone hotspot system

    NASA Astrophysics Data System (ADS)

    Bolte, Torsten; Holtz, Francois; Almeev, Renat; Nash, Barbara

    2015-02-01

    The magma storage conditions of the 6.62 Ma Blacktail Creek Tuff eruption, belonging to the Heise volcanic field (6.62-4.45 Ma old) of the Yellowstone hotspot system, have been investigated by combining thermobarometric and experimental approaches. The results from different geothermometers (e.g., Fe-Ti oxides, feldspar pairs, apatite and zircon solubility, and Ti in quartz) indicate a pre-eruptive temperature in the range 825-875 °C. The temperature estimated using two-pyroxene pairs varies in a range of 810-950 °C, but the pyroxenes are probably not in equilibrium with each other, and the analytical results of melt inclusion in pyroxenes indicate a complex history for clinopyroxene, which hosts two compositionally different inclusion types. One natural Blacktail Creek Tuff rock sample has been used to determine experimentally the equilibrium phase assemblages in the pressure range 100-500 MPa and a water activity range 0.1-1.0. The experiments have been performed at fluid-present conditions, with a fluid phase composed of H2O and CO2, as well as at fluid-absent conditions. The stability of the quartzo-feldspathic phases is similar in both types of experiments, but the presence of mafic minerals such as biotite and clinopyroxene is strongly dependent on the experimental approach. Possible explanations are given for this discrepancy which may have strong impacts on the choice of appropriate experimental approaches for the determination of magma storage conditions. The comparison of the composition of natural phases and of experimentally synthesized phases confirms magma storage temperatures of 845-875 °C. Melt water contents of 1.5-2.5 wt% H2O are required to reproduce the natural Blacktail Creek Tuff mineral assemblage at these temperatures. Using the Ti-in-quartz barometer and the Qz-Ab-Or proportions of natural matrix glasses, coexisting with quartz, plagioclase and sanidine, the depth of magma storage is estimated to be in a pressure range between 130 and

  20. Studies on the synthesis of (-)-spinosyn a: application of the steric directing group strategy to transannular Diels-Alder reactions.

    PubMed

    Frank, Scott A; Roush, William R

    2002-06-14

    A highly diastereoselective and enantioselective synthesis of the decahydro-as-indacene nucleus 12 of (-)-spinosyn A (1) is reported. By implementing the steric directing group strategy, tricyclic lactone 37 was produced from a remarkably diastereoselective transannular Diels-Alder reaction of lactone 9. The tricyclic core of the natural product was then obtained by using an Ireland-Claisen ring contraction of 37. Reversal of the order of these two steps resulted in an almost complete loss of diastereoselectivity. PMID:12054969

  1. Copper-Catalyzed Aza-Diels-Alder Reaction and Halogenation: An Approach To Synthesize 7-Halogenated Chromenoquinolines.

    PubMed

    Yu, Xiaoqiang; Wang, Jiao; Xu, Zhanwei; Yamamoto, Yoshinori; Bao, Ming

    2016-05-20

    A new halogenation method to construct halogen-substituted quinoline moieties is described. The Cu-catalyzed intramolecular aza-Diels-Alder reaction and halogenation reaction proceeded smoothly under mild conditions to produce the corresponding 7-chloro-6H-chromeno[4,3-b]quinolines and 7-chloro-6H-thiochromeno[4,3-b]quinolines in satisfactory yields. PMID:27145113

  2. Quantitative structure-activation barrier relationship modeling for Diels-Alder ligations utilizing quantum chemical structural descriptors

    PubMed Central

    2013-01-01

    Background In the present study, we show the correlation of quantum chemical structural descriptors with the activation barriers of the Diels-Alder ligations. A set of 72 non-catalysed Diels-Alder reactions were subjected to quantitative structure-activation barrier relationship (QSABR) under the framework of theoretical quantum chemical descriptors calculated solely from the structures of diene and dienophile reactants. Experimental activation barrier data were obtained from literature. Descriptors were computed using Hartree-Fock theory using 6-31G(d) basis set as implemented in Gaussian 09 software. Results Variable selection and model development were carried out by stepwise multiple linear regression methodology. Predictive performance of the quantitative structure-activation barrier relationship (QSABR) model was assessed by training and test set concept and by calculating leave-one-out cross-validated Q2 and predictive R2 values. The QSABR model can explain and predict 86.5% and 80% of the variances, respectively, in the activation energy barrier training data. Alternatively, a neural network model based on back propagation of errors was developed to assess the nonlinearity of the sought correlations between theoretical descriptors and experimental reaction barriers. Conclusions A reasonable predictability for the activation barrier of the test set reactions was obtained, which enabled an exploration and interpretation of the significant variables responsible for Diels-Alder interaction between dienes and dienophiles. Thus, studies in the direction of QSABR modelling that provide efficient and fast prediction of activation barriers of the Diels-Alder reactions turn out to be a meaningful alternative to transition state theory based computation. PMID:24171724

  3. A Catalyst-Enabled Diastereodivergent Aza-Diels-Alder Reaction: Complementarity of N-Heterocyclic Carbenes and Chiral Amines.

    PubMed

    Rong, Zi-Qiang; Wang, Min; Chow, Chi Hao Eugene; Zhao, Yu

    2016-07-01

    Highly efficient and diastereodivergent aza-Diels-Alder reactions have been developed to access either diastereomeric series of benzofuran-fused δ-lactams and dihydropyridines in nearly perfect stereoselectivity (d.r. >20:1, >99 % ee for all examples). The complementarity of N-heterocyclic carbene and chiral amine as the catalyst was demonstrated for the first time, together with an excellent level of catalytic efficiency (1 mol % loading). PMID:27219298

  4. A new approach to the synthesis of monomers and polymers incorporating furan/maleimide Diels-Alder adducts

    NASA Astrophysics Data System (ADS)

    Banella, Maria Barbara; Gioia, Claudio; Vannini, Micaela; Colonna, Martino; Celli, Annamaria; Gandini, Alessandro

    2016-05-01

    The Diels-Alder reaction between furan and maleimide moieties is a well-known and widely used strategy to build bio-based macromolecular structures with peculiar properties. The furan-maleimide adducts are thermally reversible because they can be broken above about 120°C and recombined at lower temperatures. At the moment only the monomers exhibiting the furan or the maleimide moieties on their extremity are used in order to get linear or cross-linked polymeric structures. The innovative idea described here consists in using a monomer bearing two carboxylic acidic groups on its extremities and a furan-maleimide Diels-Alder adduct within its structure. This monomer can give rise to classical polycondensation reactions leading to polymers. These polymers (which are polyesters in the present case) can be broken at high temperatures in correspondence of the furane-maleimide Diels-Alder adduct leading to segments exhibiting furan or maleimide moieties at their extremities, which at lower temperature recombine leading to random or block copolymers.

  5. Performance of ectomycorrhizal alders exposed to specific Canadian oil sands tailing stressors under in vivo bipartite symbiotic conditions.

    PubMed

    Beaudoin-Nadeau, Martin; Gagné, André; Bissonnette, Cyntia; Bélanger, Pier-Anne; Fortin, J André; Roy, Sébastien; Greer, Charles W; Khasa, Damase P

    2016-07-01

    Canadian oil sands tailings are predominately sodic residues contaminated by hydrocarbons such as naphthenic acids. These conditions are harsh for plant development. In this study, we evaluated the effect of inoculating roots of Alnus viridis ssp. crispa and Alnus incana ssp. rugosa with ectomycorrhizal fungi in the presence of tailings compounds. Seedlings were inoculated with 7 different strains of Paxillus involutus and Alpova diplophloeus and were grown under different treatments of NaCl, Na2SO4, and naphthenic acids in a growth chamber. Afterwards, seedling survival, height, dry biomass, leaf necrosis, and root mycorrhization rate were measured. Paxillus involutus Mai was the most successful strain in enhancing alder survival, health, and growth. Seedlings inoculated with this strain displayed a 25% increase in survival rate, 2-fold greater biomass, and 2-fold less leaf necrosis compared with controls. Contrary to our expectations, A. diplophloeus was not as effective as P. involutus in improving seedling fitness, likely because it did not form ectomycorrhizae on roots of either alder species. High intraspecific variation characterized strains of P. involutus in their ability to stimulate alder height and growth and to minimize leaf necrosis. We conclude that in vivo selection under bipartite symbiotic conditions is essential to select effective strains that will be of use for the revegetation and reclamation of derelict lands. PMID:27170470

  6. Design Paradigm Utilizing Reversible Diels-Alder Reactions to Enhance the Mechanical Properties of 3D Printed Materials.

    PubMed

    Davidson, Joshua R; Appuhamillage, Gayan A; Thompson, Christina M; Voit, Walter; Smaldone, Ronald A

    2016-07-01

    A design paradigm is demonstrated that enables new functional 3D printed materials made by fused filament fabrication (FFF) utilizing a thermally reversible dynamic covalent Diels-Alder reaction to dramatically improve both strength and toughness via self-healing mechanisms. To achieve this, we used as a mending agent a partially cross-linked terpolymer consisting of furan-maleimide Diels-Alder (fmDA) adducts that exhibit reversibility at temperatures typically used for FFF printing. When this mending agent is blended with commercially available polylactic acid (PLA) and printed, the resulting materials demonstrate an increase in the interfilament adhesion strength along the z-axis of up to 130%, with ultimate tensile strength increasing from 10 MPa in neat PLA to 24 MPa in fmDA-enhanced PLA. Toughness in the z-axis aligned prints increases by up to 460% from 0.05 MJ/m(3) for unmodified PLA to 0.28 MJ/m(3) for the remendable PLA. Importantly, it is demonstrated that a thermally reversible cross-linking paradigm based on the furan-maleimide Diels-Alder (fmDA) reaction can be more broadly applied to engineer property enhancements and remending abilities to a host of other 3D printable materials with superior mechanical properties. PMID:27299858

  7. Effects of fungal inocula and habitat conditions on alder and eucalyptus leaf litter decomposition in streams of northern Spain.

    PubMed

    Pérez, Javier; Galán, Javier; Descals, Enrique; Pozo, Jesús

    2014-02-01

    We investigated how fungal decomposer (aquatic hyphomycetes) communities colonizing alder and eucalyptus leaf litter respond to changes in habitat characteristics (transplantation experiment). We examined the breakdown of leaf materials and the associated fungal communities at two contrasting sites, a headwater stream (H) and a midreach (M). Agroforestry increased from headwater to midreach. One month after the start of experiments at both sites, some leaf samples from the midreach site were transplanted to the headwater site (M-H treatment). Although both sites showed similar dissolved inorganic nutrient concentrations, eucalyptus leaves initially incubated at the midreach site (M, M-H) increased their breakdown rate compared to those incubated along the experiment at the headwater site (H). Alder breakdown rate was not enhanced, suggesting that their consumption was not limited by nutrient availability. Sporulation rates clearly differed between leaf types (alder > eucalyptus) and streams (H > M), but no transplantation effect was detected. When comparing conidial assemblages after transplantation, an inoculum effect (persistence of early colonizing species) was clear in both leaf species. Substrate preference and shifts in the relative importance of some fungal species along the process were also observed. Overall, our results support the determining role of the initial conditioning phase on the whole litter breakdown process, highlighting the importance of intrinsic leaf characteristics and those of the incubation habitat. PMID:24141942

  8. Short-term influence of nitrate on acetylene reduction, photosynthesis and nodule respiration of black alder seedlings

    SciTech Connect

    Cazell, B.H.; Samuelson, L.J.; Seiler, J.R. )

    1990-05-01

    Black alder (Alnus glutinosa L. Gaernt.) has shown significant benefits in several silvicultural applications such as nurse-trees. However, little is known concerning the nitrate/N-fixing interactions. Our objections were to examine the effects of three nitrate levels on acetylene reduction (AR), net photosynthesis (Ps) and nodule respiration (NR). Fifteen month-old black alder rooted cuttings were inoculated with one strain of Frankia inoculum (ARgN22D) at six months, maintained under 16h photoperiod at ambient greenhouse conditions, and fertilized for two months prior to study with a modified Crone's N-free solution. At study initiation seedlings were fertilized for six days with 0, 7.5 or 15 mM NO{sub 3}{sup {minus}}. Measurements of AR, Ps and NR were collected on the second, fourth and sixth day of NO{sub 3}{sup {minus}} application. By day four AR was significantly lowered by 75% for the 15 mM NO{sub 3}{sup {minus}} treatment when compared with the controls. On day six, Ps and NR were lowered significantly by 29% and 59%, respectively, for the 15 mM NO{sub 3}{sup {minus}} treatments when compared to control values. Results suggest any benefit from black alder N-fixation might be negated by nitrate fertilization.

  9. A Soil Moisture-Heat Based Early Establishment Model of Riparian White Alder (Alnus rhombifolia)

    NASA Astrophysics Data System (ADS)

    Jablkowski, P.; Johnson, E. A.; Martin, Y. E.

    2013-12-01

    Establishment of fluvially dispersed seeds on accreted gravel-sand bars is limited by water availability in streams. Past establishment models have used the stream/water table recession rate, and maximum root growth rate to determine the elevation limit of seedling establishment. This approach neglects the role of the saturated-unsaturated vadose zone in providing water to recently germinated seedlings, the physical processes that determine the soil moisture content, and the effect moisture deficit has on seedling root growth. This study combines a soil moisture-heat budget and a seedling root growth model that responds to soil moisture availability to find the elevation limit of establishment of white alder (Alnus rhombifolia) on vertically accreted bars along the south fork Eel River in the Angelo Coast Range Reserve, California. To establish successfully, seedling roots must maintain a connection with sufficient moisture to avoid water stress. This will depend on the elevation of the bar, the stream recession rate, the root growth rate, and the diurnal cycle of soil moisture. A one-dimensional moisture-heat budget of the top 15 centimeters of sediment was validated at two locations characterized by sand and clay-gravel textures respectively, using soil moisture and temperature measurements at 5, 10 and 15 cm, net radiation, air temperature, humidity, wind velocity and precipitation measured during spring-summer stream recession. Two patterns in soil water content were apparent: an average daily moisture decrease at each depth driven by stream/water table recession, and a diurnal pattern of isothermal liquid and vapour flux increasing soil water content in the upper 15 cm between 12:00 pm and 5:00 pm PDT. To determine seedling root growth rates, white alder seedlings were grown in growth chambers under a range of reduced matric potentials using polyethylene glycol. Root length measurements were made at 4 hour intervals and a quadratic equation was fit to the root

  10. 77 FR 13592 - AER NY-Gen, LLC; Eagle Creek Hydro Power, LLC, Eagle Creek Water Resources, LLC, Eagle Creek Land...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-07

    ... Energy Regulatory Commission AER NY-Gen, LLC; Eagle Creek Hydro Power, LLC, Eagle Creek Water Resources... Comments and Motions To Intervene On February 24, 2012, AER NY-Gen, LLC (transferor), Eagle Creek Hydro...' Contact: Transferor: Mr. Joseph Klimaszewski, AER NY- Gen, LLC, P.O. Box 876, East Aurora, NY 14052,...

  11. 75 FR 5631 - Wolf Creek Nuclear Operating Corporation, Wolf Creek Generating Station; Environmental Assessment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-03

    ... Federal Register notice dated March 27, 2009 (74 FR 13967). There will be no change to radioactive... no significant impact [Part 73, Power Reactor Security Requirements, 74 FR 13926, 13967 (March 27... COMMISSION Wolf Creek Nuclear Operating Corporation, Wolf Creek Generating Station; Environmental...

  12. 4. O'BRIAN CANAL/SECOND CREEK INTERSECTION Second Creek is in the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. O'BRIAN CANAL/SECOND CREEK INTERSECTION Second Creek is in the foreground; the O'Brian Canal is in the background; vicinity of East 112th Avenue and Potomac Road in Adams County - O'Brian Canal, South Platte River Drainage Area Northest of Denver, Brighton, Adams County, CO

  13. Hoe Creek groundwater restoration, 1989

    SciTech Connect

    Renk, R.R.; Crader, S.E.; Lindblom, S.R.; Covell, J.R.

    1990-01-01

    During the summer of 1989, approximately 6.5 million gallons of contaminated groundwater were pumped from 23 wells at the Hoe Creek underground coal gasification site, near Gillette, Wyoming. The organic contaminants were removed using activated carbon before the water was sprayed on 15.4 acres at the sites. Approximately 2647 g (5.8 lb) of phenols and 10,714 g (23.6 lb) of benzene were removed from the site aquifers. Phenols, benzene, toluene, ethylbenzene, and naphthalene concentrations were measured in 43 wells. Benzene is the only contaminant at the site exceeds the federal standard for drinking water (5 {mu}g/L). Benzene leaches into the groundwater and is slow to biologically degrade; therefore, the benzene concentration has remained high in the groundwater at the site. The pumping operation affected groundwater elevations across the entire 80-acre site. The water levels rebounded quickly when the pumping operation was stopped on October 1, 1989. Removing contaminated groundwater by pumping is not an effective way to clean up the site because the continuous release of benzene from coal tars is slow. Benzene will continue to leach of the tars for a long time unless its source is removed or the leaching rate retarded through mitigation techniques. The application of the treated groundwater to the surface stimulated plant growth. No adverse effects were noted or recorded from some 60 soil samples taken from twenty locations in the spray field area. 20 refs., 52 figs., 8 tabs.

  14. Silylium ion-catalyzed challenging Diels-Alder reactions: the danger of hidden proton catalysis with strong Lewis acids.

    PubMed

    Schmidt, Ruth K; Müther, Kristine; Mück-Lichtenfeld, Christian; Grimme, Stefan; Oestreich, Martin

    2012-03-01

    The pronounced Lewis acidity of tricoordinate silicon cations brings about unusual reactivity in Lewis acid catalysis. The downside of catalysis with strong Lewis acids is, though, that these do have the potential to mediate the formation of protons by various mechanisms, and the thus released Brønsted acid might even outcompete the Lewis acid as the true catalyst. That is an often ignored point. One way of eliminating a hidden proton-catalyzed pathway is to add a proton scavenger. The low-temperature Diels-Alder reactions catalyzed by our ferrocene-stabilized silicon cation are such a case where the possibility of proton catalysis must be meticulously examined. Addition of the common hindered base 2,6-di-tert-butylpyridine resulted, however, in slow decomposition along with formation of the corresponding pyridinium ion. Quantitative deprotonation of the silicon cation was observed with more basic (Mes)(3)P to yield the phosphonium ion. A deuterium-labeling experiment verified that the proton is abstracted from the ferrocene backbone. A reasonable mechanism of the proton formation is proposed on the basis of quantum-chemical calculations. This is, admittedly, a particular case but suggests that the use of proton scavengers must be carefully scrutinized, as proton formation might be provoked rather than prevented. Proton-catalyzed Diels-Alder reactions are not well-documented in the literature, and a representative survey employing TfOH is included here. The outcome of these catalyses is compared with our silylium ion-catalyzed Diels-Alder reactions, thereby clearly corroborating that hidden Brønsted acid catalysis is not operating with our Lewis acid. Several simple-looking but challenging Diels-Alder reactions with exceptionally rare dienophile/enophile combinations are reported. Another indication is obtained from the chemoselectivity of the catalyses. The silylium ion-catalyzed Diels-Alder reaction is general with regard to the oxidation level of the

  15. Blasting of the Twin Creek`s highwall failure

    SciTech Connect

    Gray, C.J.; Bachmann, J.A.

    1996-12-01

    On December 26, 1994, at 1:00 a.m., the Twin Creeks Mine experienced a major highwall failure involving over 2.5 million tons. The long chain of events that led up to this failure actually started in late August when a truck driver first noticed the cracks in the highwall. Soon after, an intense survey prism monitoring program was initiated. An electronic, continuous monitor linked to Dispatch was soon in place which monitored the crack that was most likely to fail into the active pit area first. It wasn`t until early December when the graphs started showing greater increases in movement. On December 22, the acceleration curves skied-out. The 600 ft. highwall finally collapsed about three days later and left material spread 800 ft. across the bottom of the pit. Not knowing if the large overhangs above the slide would soon give away sending more material into the pit or if the numerous tension cracks on the surface would result in yet another major failure, it was only after restoring the rigid monitoring program and observing no movement that the company decided to drill and blast the overhanging material. The purpose of the blast wasn`t to cast the material into the pit, but to kick-out the toe so that the weight of material above would fall upon itself. After two months of preparation and almost three weeks of drilling and loading, the shot occurred on March 21, 1995. Approximately one million tons were successfully blasted that day, and presently they have completed mining the slough material itself and reestablished benches from the top.

  16. Baseline Characteristics of Jordan Creek, Juneau, Alaska

    USGS Publications Warehouse

    Host, Randy H.; Neal, Edward G.

    2004-01-01

    Anadromous fish populations historically have found healthy habitat in Jordan Creek, Juneau, Alaska. Concern regarding potential degradation to the habitat by urban development within the Mendenhall Valley led to a cooperative study among the City and Borough of Juneau, Alaska Department of Environmental Conservation, and the U.S. Geological Survey, that assessed current hydrologic, water-quality, and physical-habitat conditions of the stream corridor. Periods of no streamflow were not uncommon at the Jordan Creek below Egan Drive near Auke Bay stream gaging station. Additional flow measurements indicate that periods of no flow are more frequent downstream of the gaging station. Although periods of no flow typically were in March and April, streamflow measurements collected prior to 1999 indicate similar periods in January, suggesting that no flow conditions may occur at any time during the winter months. This dewatering in the lower reaches likely limits fish rearing and spawning habitat as well as limiting the migration of juvenile salmon out to the ocean during some years. Dissolved-oxygen concentrations may not be suitable for fish survival during some winter periods in the Jordan Creek watershed. Dissolved-oxygen concentrations were measured as low as 2.8 mg/L at the gaging station and were measured as low as 0.85 mg/L in a tributary to Jordan Creek. Intermittent measurements of pH and dissolved-oxygen concentrations in the mid-reaches of Jordan Creek were all within acceptable limits for fish survival, however, few measurements of these parameters were made during winter-low-flow conditions. One set of water quality samples was collected at six different sites in the Jordan Creek watershed and analyzed for major ions and dissolved nutrients. Major-ion chemistry showed Jordan Creek is calcium bicarbonate type water with little variation between sampling sites.

  17. A Single Molecular Diels-Alder Crosslinker for Achieving Recyclable Cross-Linked Polymers.

    PubMed

    Chen, Shengli; Wang, Fenfen; Peng, Yongjin; Chen, Tiehong; Wu, Qiang; Sun, Pingchuan

    2015-09-01

    A triol-functional crosslinker combining the thermoreversible properties of Diels-Alder (DA) adducts in one molecule is designed, synthesized, and used as an ideal substitute of a traditional crosslinker to prepare thermal recyclable cross-linked polyurethanes with excellent mechanical properties and recyclability in a very simple and efficient way. The recycle property of these materials achieved by the DA/retro-DA reaction at a suitable temperature is verified by differential scanning calorimetry and in situ variable temperature solid-state NMR experiments during the cyclic heating and cooling processes. The thermal recyclability and remending ability of the bulk polyurethanes is demonstrated by three polymer processing methods, including hot-press molding, injection molding, and solution casting. It is notable that all the recycled cross-linked polymers display nearly invariable elongation/stress at break compared to the as-synthesized samples. Further end-group functionalization of this single molecular DA crosslinker provides the potential in preparing a wide range of recyclable cross-linked polymers. PMID:26248230

  18. Artificial Metalloenzymes with the Neocarzinostatin Scaffold: Toward a Biocatalyst for the Diels-Alder Reaction.

    PubMed

    Ghattas, Wadih; Cotchico-Alonso, Lur; Maréchal, Jean-Didier; Urvoas, Agathe; Rousseau, Maëva; Mahy, Jean-Pierre; Ricoux, Rémy

    2016-03-01

    A copper(II) cofactor coupled to a testosterone anchor, copper(II)-(5-(Piperazin-1-yl)-1,10-phenanthroline)testosterone-17-hemisuccinamide (10) was synthesized and associated with a neocarzinostatin variant, NCS-3.24 (KD =3 μm), thus generating a new artificial metalloenzyme by following a "Trojan horse" strategy. Interestingly, the artificial enzyme was able to efficiently catalyze the Diels-Alder cyclization reaction of cyclopentadiene (1) with 2-azachalcone (2). In comparison with what was observed with cofactor 10 alone, the artificial enzymes favored formation of the exo products (endo/exo ratios of 84:16 and 62:38, respectively, after 12 h). Molecular modeling studies assigned the synergy between the copper complex and the testosterone (KD =13 μm) moieties in the binding of 10 to good van der Waals complementarity. Moreover, by pushing the modeling exercise to its limits, we hypothesize on the molecular grounds that are responsible for the observed selectivity. PMID:26677011

  19. Combinatorial Synthesis of Linearly Condensed Polycyclic Compounds, Including Anthracyclinones, Through Tandem Diels-Alder Additions

    NASA Astrophysics Data System (ADS)

    Vogel, Pierre

    Double exocyclic 1,3-dienes such as 2,3,5,6-tetramethylidene-7-oxabicyclo[2.2.1]heptane and its 1-substituted derivatives undergo two successive Diels-Alder additions with large reactivity difference between the addition of the first equivalent (k 1) and the second equivalent (k 2) of dienophile. This allows one to prepare, through parallel synthesis, a large number of linearly condensed polycyclic systems containing three annulated six-membered rings, including naphthacenyl systems and anthracyclinones. The large k 1/k 2 rate constant ratio is a consequence of the Dimroth principle, the first cycloaddition being significantly more exothermic then the second one. Control of regio- and stereoselectivity of the two successive cycloadditions is possible by 1-substitution of the 2,3,5,6-tetramethylidene-7-oxabicyclo[2.2.1]heptane, for instance by a 1-(dimethoxymethyl) group, or by stereoselective disubstitution of the double diene by arenesulfenyl substituents. Enantiomerically pure anthracyclinones and analogues are obtained using enantiomerically pure dienophiles such as 3-oxo-but-2-en-2-yl esters. The chemistry so-developed has allowed the preparation of enantiomerically pure 6-((aminoalkoxy)oxy)methyl-6,7-dideoxyidarubicinones that are DNA intercalators and inhibitors of topoisomerase II-induced DNA strained religation.

  20. Vanadium redox flow battery efficiency and durability studies of sulfonated Diels Alder poly(phenylene)s

    SciTech Connect

    Fujimoto, Cy H.; Kim, Soowhan; Stains, Ronald; Wei, Xiaoliang; Li, Liyu; Yang, Zhenguo

    2012-07-01

    Sulfonated Diels Alder poly(phenylene) (SDAPP) was examined for vanadium redox flow battery (VRFB) use. The ion exchange capacity (IEC) was varied from 1.4, 1.6 and 2.0 meq/g in order to tune the proton conductivity and vanadium permeability. Coulombic efficiencies between 92 to 99% were observed, depending on IEC (lower IEC, higher coulombic efficiencies). In all cases the SDAPP displayed comparable energy efficiencies (88 - 90%) to Nafion 117 (88%) at 50mA/cm2. Membrane durability also was dependent on IEC; SDAPP with the highest IEC lasted slightly over 50 cycles while SDAPP with the lowest IEC lasted over 400 cycles and testing was discontinued only due to time constraints. Accelerated vanadium lifetime studies were initialed with SDAPP, by soaking films in a 0.1 M V5+ and 5.0 M total SO4-2 solution. The rate of degradation was also proportional with IEC; the 2 meq/g sample dissolved within 376 hours, the 1.6 meq/g sample dissolved after 860 hours, while the 1.4 meq/g sample broke apart after 1527 hours.

  1. Diels Alder polyphenylene anion exchange membrane for nonaqueous redox flow batteries

    SciTech Connect

    Small, Leo J.; Pratt, III, Harry D.; Fujimoto, Cy H.; Anderson, Travis M.

    2015-10-23

    Here highly conductive, solvent-resistant anionic Diels Alder polyphenylene (DAPP) membranes were synthesized with three different ionic contents and tested in an ionic liquid-based nonaqueous redox flow battery (RFB). These membranes display 3–10× increase in conductivity in propylene carbonate compared to some commercially available (aqueous) anion exchange membranes. The membrane with an ion content of 1.5 meq/g (DAPP1.5) proved too brittle for operation in a RFB, while the membrane with an ion content of 2.5 meq/g (DAPP2.5) allowed excessive movement of solvent and poor electrochemical yields (capacity fade). Despite having lower voltage efficiencies compared to DAPP2.5, the membrane with an intermediate ion content of 2.0 meq/g (DAPP2.0) exhibited higher coulombic efficiencies (96.4% vs. 89.1%) and electrochemical yields (21.6% vs. 10.9%) after 50 cycles. Crossover of the electroactive species was the primary reason for decreased electrochemical yields. Analysis of the anolyte and catholyte revealed degradation of the electroactive species and formation of a film at the membrane-solution interface. Increases in membrane resistance were attributed to mechanical and thermal aging of the membrane; no chemical change was observed. As a result, improvements in the ionic selectivity and ionic conductivity of the membrane will increase the electrochemical yield and voltage efficiency of future nonaqueous redox flow batteries.

  2. Storing solar energy with liquid phase Diels-Alder reactions. Final report

    SciTech Connect

    Poling, B.E.

    1983-07-28

    At the beginning of this project, a preliminary study was completed that indicated the Diels-Alder reaction between maleic anhydride and 2 methyl furan had an energy storage capacity greater than water. During the last two years when this grant was in effect, three additional projects have been completed. First, an improved calorimetric techniques was developed for determination of the energy storage capacity of a reversible liquid phase chemical reaction. This technique confirmed the validity of the earlier results for the maleic anhydride-methyl furan reaction. Second, a technique was developed for characterizing solution nonidealities for mixtures in which reversible chemical reactions occur. It was found that for the maleic anhydride-2 methyl furan reaction, these non idealities could affect equilibrium compositions by nearly 40%. Third, drop calorimetry was used as a screening method to examine sixteen reactions for their potential as energy storage candidates. Of the sixteen examined, three (all involving maleic anhydride and substituted furan) showed an increased energy storage capacity due to reaction while the remaining thirteen showed no increase. In the following report, results of these three studies are summarized. Finally, a general summary of the status of energy storage by chemical reactions is presented.

  3. Surface confined retro Diels-Alder reaction driven by the swelling of weak polyelectrolytes.

    PubMed

    Lyu, Beier; Cha, Wenli; Mao, Tingting; Wu, Yuanzi; Qian, Hujun; Zhou, Yitian; Chen, Xiuli; Zhang, Shen; Liu, Lanying; Yang, Guang; Lu, Zhongyuan; Zhu, Qiang; Ma, Hongwei

    2015-03-25

    Recently, the type of reactions driven by mechanical force has increased significantly; however, the number of methods for activating those mechanochemical reactions stays relatively limited. Furthermore, in situ characterization of a reaction is usually hampered by the inherent properties of conventional methods. In this study, we report a new platform that utilizes mechanical force generated by the swelling of surface tethered weak polyelectrolytes. An initiator with Diels-Alder (DA) adduct structure was applied to prepare the polyelectrolyte-carboxylated poly(OEGMA-r-HEMA), so that the force could trigger the retro DA reaction. The reaction was monitored in real time by quartz crystal microbalance and confirmed with atomic force microscopy and X-ray photoelectron spectroscopy. Compared with the conventional heating method, the swelling-induced retro DA reaction proceeded rapidly with high conversion ratio and selectivity. A 23.61 kcal/mol theoretical energy barrier supported the practicability of this retro DA reaction being triggered mechanically at ambient temperature. During swelling, the tensile force was controllable and persistent. This unique feature imparts this mechanochemical platform the potential to "freeze" an intermediate state of a reaction for in situ spectroscopic observations, such as surface-enhanced Raman spectroscopy and frequency generation spectroscopy. PMID:25734373

  4. Diels Alder polyphenylene anion exchange membrane for nonaqueous redox flow batteries

    DOE PAGESBeta

    Small, Leo J.; Pratt, III, Harry D.; Fujimoto, Cy H.; Anderson, Travis M.

    2015-10-23

    Here highly conductive, solvent-resistant anionic Diels Alder polyphenylene (DAPP) membranes were synthesized with three different ionic contents and tested in an ionic liquid-based nonaqueous redox flow battery (RFB). These membranes display 3–10× increase in conductivity in propylene carbonate compared to some commercially available (aqueous) anion exchange membranes. The membrane with an ion content of 1.5 meq/g (DAPP1.5) proved too brittle for operation in a RFB, while the membrane with an ion content of 2.5 meq/g (DAPP2.5) allowed excessive movement of solvent and poor electrochemical yields (capacity fade). Despite having lower voltage efficiencies compared to DAPP2.5, the membrane with an intermediatemore » ion content of 2.0 meq/g (DAPP2.0) exhibited higher coulombic efficiencies (96.4% vs. 89.1%) and electrochemical yields (21.6% vs. 10.9%) after 50 cycles. Crossover of the electroactive species was the primary reason for decreased electrochemical yields. Analysis of the anolyte and catholyte revealed degradation of the electroactive species and formation of a film at the membrane-solution interface. Increases in membrane resistance were attributed to mechanical and thermal aging of the membrane; no chemical change was observed. As a result, improvements in the ionic selectivity and ionic conductivity of the membrane will increase the electrochemical yield and voltage efficiency of future nonaqueous redox flow batteries.« less

  5. Calibration of a Carboniferous U-Pb and Ar-Ar Standard

    NASA Astrophysics Data System (ADS)

    Shea, E. K.; Machlus, M.; Hemming, S. R.; Bowring, S. A.

    2015-12-01

    An important goal of the EARTHTIME initiative is to produce an accurate and precise sequence of geologic events, allowing the evaluation of the rates of geologic processes. Toward this end, the Ar-Ar and U-Pb communities require a set of standards that permit inter-laboratory and inter-technique comparisons. Natural zircon and sanidine samples that are extensively analyzed by multiple labs play a critical role for these comparisons, but are currently limited in number (Plesovice, R33, Temora 2 zircons; Fish Canyon, Alder Creek, Taylor Creek sanidine). Calibration between the sanidine Ar-Ar and zircon U-Pb is sparse and complexity in one or both of the systems is a general problem. Further, there is currently no Paleozoic sanidine monitor standard for Ar-Ar geochronology. The sanidine- and zircon-bearing Carboniferous Fire Clay tonstein provides potential natural Paleozoic standards for these two systems. The Fire Clay tonstein is a voluminous Carboniferous ash bed from the Appalachian basin. Exposures of the tonstein span over 300 km, making it a valuable marker bed for Appalachian geology. Here we report the results of 64 single-grain zircon U-Pb TIMS analyses and 223 single-grain sanidine Ar/Ar analyses. Although previous efforts have been plagued by xenocrystic zircons, by careful selection of only elongate crystals we were able to entirely avoid discordant analyses older than 316 Ma. Unfiltered analyses of zircons analyzed from a population of acicular crystals give a range of dates between ~315 and ~314 Ma with 2 sigma uncertainties of ~0.2 Ma. A weighted mean of these dates has an MSWD of ~4.0, suggesting geological complexity in the magma chamber or post-eruption lead loss. Sanidine ages have a range of less than 1 %, and only a single population can be distinguished with precision at the 1 Ma level for individual crystals. The ability to select crystals of both zircon and sanidine that give a narrow range of ages suggests that the Fire Clay tonstein holds

  6. FIDDLER CREEK POLYMER AUGMENTATION PROJECT

    SciTech Connect

    Lyle A. Johnson, Jr.

    2001-10-31

    The Fiddler Creek field is in Weston County, Wyoming, and was discovered in 1948. Secondary waterflooding recovery was started in 1955 and terminated in the mid-1980s with a fieldwide recovery of approximately 40%. The West Fiddler Creek Unit, the focus of this project, had a lower recovery and therefore has the most remaining oil. Before the project this unit was producing approximately 85 bbl of oil per day from 20 pumping wells and 17 swab wells. The recovery process planned for this project involved adapting two independent processes, the injection of polymer as a channel blocker or as a deep-penetrating permeability modifier, and the stabilization of clays and reduction of the residual oil saturation in the near-wellbore area around the injection wells. Clay stabilization was not conducted because long-term fresh water injection had not severely reduced the injectivity. It was determined that future polymer injection would not be affected by the clay. For the project, two adjoining project patterns were selected on the basis of prior reservoir studies and current well availability and production. The primary injection well of Pattern 1 was treated with a small batch of MARCIT gel to create channel blocking. The long-term test was designed for three phases: (1) 77 days of injection of a 300-mg/l cationic polyacrylamide, (2) 15 days of injection of a 300-mg/l anionic polymer to ensure injectivity of the polymer, and (3) 369 days of injection of the 300-mg/l anionic polymer and a 30:1 mix of the crosslinker. Phases 1 and 2 were conducted as planned. Phase 3 was started in late March 1999 and terminated in May 2001. In this phase, a crosslinker was added with the anionic polymer. Total injection for Phase 3 was 709,064 bbl. To maintain the desired injection rate, the injection pressure was slowly increased from 1,400 psig to 2,100 psig. Early in the application of the polymer, it appeared that the sweep improvement program was having a positive effect on Pattern 1

  7. Environmental setting of Maple Creek watershed, Nebraska

    USGS Publications Warehouse

    Fredrick, Brian S.; Linard, Joshua I.; Carpenter, Jennifer L.

    2006-01-01

    The Maple Creek watershed covers a 955-square-kilometer area in eastern Nebraska, which is a region dominated by agricultural land use. The Maple Creek watershed is one of seven areas currently included in a nationwide study of the sources, transport, and fate of water and chemicals in agricultural watersheds. This study, known as the topical study of 'Agricultural Chemicals: Sources, Transport, and Fate' is part of the National Water-Quality Assessment Program being conducted by the U.S. Geological Survey. The Program is designed to describe water-quality conditions and trends based on representative surface- and ground-water resources across the Nation. The objective of the Agricultural Chemicals topical study is to investigate the sources, transport, and fate of selected agricultural chemicals in a variety of agriculturally diverse environmental settings. The Maple Creek watershed was selected for the Agricultural Chemicals topical study because its watershed represents the agricultural setting that characterizes eastern Nebraska. This report describes the environmental setting of the Maple Creek watershed in the context of how agricultural practices, including agricultural chemical applications and irrigation methods, interface with natural settings and hydrologic processes. A description of the environmental setting of a subwatershed within the drainage area of Maple Creek is included to improve the understanding of the variability of hydrologic and chemical cycles at two different scales.

  8. 78 FR 12714 - Intermountain Region, Payette National Forest, New Meadows Ranger District, Idaho; Lost Creek...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-25

    ... District, Idaho; Lost Creek-Boulder Creek Landscape Restoration Project AGENCY: Forest Service, USDA... Creek-Boulder Creek Landscape Restoration Project. The Lost Creek- Boulder Creek Landscape Restoration... converted to ATV trails; restoration of 90 miles of unauthorized roads; and relocation of 1\\ 1/2\\ half...

  9. Steel Creek fish: L-Lake/Steel Creek Biological Monitoring Program, January 1986--December 1987

    SciTech Connect

    Paller, M.H.; Heuer, J.H.; Kissick, L.A.

    1988-03-01

    Fish samples were collected from Steel Creek during 1986 and 1987 following the impoundment of the headwaters of the stream to form L-Lake, a cooling reservoir for L-Reactor which began operating late in 1985. Electrofishing and ichthyoplankton sample stations were located throughout the creek. Fykenetting sample stations were located in the creek mouth and just above the Steel Creek swamp. Larval fish and fish eggs were collected with 0.5 m plankton nets. Multivariate analysis of the electrofishing data suggested that the fish assemblages in Steel Creek exhibited structural differences associated with proximity to L-Lake, and habitat gradients of current velocity, depth, and canopy cover. The Steel Creek corridor, a lotic reach beginning at the base of the L-Lake embankment was dominated by stream species and bluegill. The delta/swamp, formed where Steel Creek enters the Savannah River floodplain, was dominated by fishes characteristic of slow flowing waters and heavily vegetated habitats. The large channel draining the swamp supported many of the species found in the swamp plus riverine and anadromous forms.

  10. Steel Creek water quality: L-Lake/Steel Creek Biological Monitoring Program, November 1985--December 1991

    SciTech Connect

    Bowers, J.A.; Kretchmer, D.W.; Chimney, M.J.

    1992-04-01

    The Savannah River Site (SRS) encompasses 300 sq mi of the Atlantic Coastal Plain in west-central South Carolina. The Savannah River forms the western boundary of the site. Five major tributaries of the Savannah River -- upper Three Runs Creek, Four Mile Creek, Pen Branch, Steel Creek, and Lower Three Runs Creek -- drain the site. All but Upper Three Runs Creek receive, or in the past received, thermal effluents from nuclear production reactors. In 1985, L Lake, a 400-hectare cooling reservoir, was built on the upper reaches of Steel Creek to receive effluent from the restart of L-Reactor, and protect the lower reaches from thermal impacts. The Steel Creek Biological Monitoring Program was designed to meet envirorunental regulatory requirements associated with the restart of L-Reactor and complements the Biological Monitoring Program for L Lake. This extensive program was implemented to address portions of Section 316(a) of the Clean Water Act. The Department of Energy (DOE) must demonstrate that the operation of L-Reactor will not significantly alter the established aquatic ecosystems.

  11. Big Creek Hydroelectric System, East & West Transmission Line, 241mile ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Big Creek Hydroelectric System, East & West Transmission Line, 241-mile transmission corridor extending between the Big Creek Hydroelectric System in the Sierra National Forest in Fresno County and the Eagle Rock Substation in Los Angeles, California, Visalia, Tulare County, CA

  12. 1. WATER ENTERING CONFLUENCE POOL FROM BEAR CREEK AT LEFT, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. WATER ENTERING CONFLUENCE POOL FROM BEAR CREEK AT LEFT, AND FROM SANTA ANA RIVER THROUGH TUNNEL #0 AT RIGHT. VIEW TO NORTHEAST. - Santa Ana River Hydroelectric System, Bear Creek Diversion Dam & Confluence Pool, Redlands, San Bernardino County, CA

  13. 13. Detail view of Sterling Creek lettuce shed showing second ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. Detail view of Sterling Creek lettuce shed showing second floor window sill - Richmond Hill Plantation, Sterling Creek Lettuce Shed, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  14. 15. Detail view of Sterling Creek lettuce shed showing second ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. Detail view of Sterling Creek lettuce shed showing second floor support beams. - Richmond Hill Plantation, Sterling Creek Lettuce Shed, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  15. 12. Detail view of Sterling Creek lettuce shed showing floor ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. Detail view of Sterling Creek lettuce shed showing floor joist and support beams - Richmond Hill Plantation, Sterling Creek Lettuce Shed, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  16. 1. View of Sterling Creek lettuce shed looking south, with ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. View of Sterling Creek lettuce shed looking south, with road in foreground - Richmond Hill Plantation, Sterling Creek Lettuce Shed, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  17. 5. View of Sterling Creek lettuce shed looking northwest showing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. View of Sterling Creek lettuce shed looking northwest showing office - Richmond Hill Plantation, Sterling Creek Lettuce Shed, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  18. Detail view of Fanno Creek trestle, showing trestle substructure, view ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail view of Fanno Creek trestle, showing trestle substructure, view looking north - Oregon Electric Railroad, Fanno Creek Trestle, Garden Home to Wilsonville Segment, Milepost 34.7, Garden Home, Washington County, OR

  19. Elevation of deck truss span over creek, looking NW along ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Elevation of deck truss span over creek, looking NW along U.S. route 322. - Pennsylvania Railroad, Brandywine Valley Viaduct, Spanning Brandywine Creek & U.S. Route 322, Downingtown, Chester County, PA

  20. Rock Creek and Potomac Parkway / Waterside Drive Sycamore and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Rock Creek and Potomac Parkway / Waterside Drive Sycamore and White Ash Trees, Rock Creek and Potomac Parkway, median between northbound and southbound lanes near the Waterside Drive exit and entrance ramps., Washington, District of Columbia, DC

  1. Lower connections from south. Waterville Bridge, Spanning Swatara Creek ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Lower connections from south. - Waterville Bridge, Spanning Swatara Creek at Appalachian Trail (moved from Little Pine Creek at State Route 44, Waterville, Lycoming County), Green Point, Lebanon County, PA

  2. Barrel view from southwest. Waterville Bridge, Spanning Swatara Creek ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Barrel view from southwest. - Waterville Bridge, Spanning Swatara Creek at Appalachian Trail (moved from Little Pine Creek at State Route 44, Waterville, Lycoming County), Green Point, Lebanon County, PA

  3. The Boulder Creek Batholith, Front Range, Colorado

    USGS Publications Warehouse

    Gable, Dolores J.

    1980-01-01

    The Boulder Creek batholith is the best known of several large Precambrian batholiths of similar rock composition that crop out across central Colorado. The rocks in the batholith belong to the calc-alkaline series and range in composition from granodiorite through quartz diorite (tonalite) to gneissic aplite. Two rock types dominate': the Boulder Creek Granodiorite, the major rock unit, and a more leucocratic and slightly younger unit herein named Twin Spruce Quartz Monzonite. Besides mafic inclusions, which occur mainly in hornblende-bearing phases of the Boulder Creek Granodiorite, there are cogenetic older and younger lenses, dikes, and small plutons of hornblende diorite, hornblendite, gabbro, and pyroxenite. Pyroxenite is not found in the batholith. The Boulder Creek Granodiorite in the batholith represents essentially two contemporaneous magmas, a northern body occurring in the Gold Hill and Boulder quadrangles and a larger southern body exposed in the Blackhawk and the greater parts of the Tungsten and Eldorado Springs quadrangles. The two bodies are chemically and mineralogically distinct. The northern body is richer in CaO and poorer in K2O, is more mafic, and has a larger percentage of plagioclase than the southern body. A crude sequence of rock types occurs from west to east in the batholith accompanied by a change in plagioclase composition from calcic plagioclase on the west to sodic on the east. Ore minerals tend to decrease, and the ratio potassium feldspar:plagioclase increases inward from the western contact of the batholith, indicating that the Boulder Creek batholith is similar to granodiorite batholiths the world over. Emplacement of the Boulder Creek batholith was contemporaneous with plastic deformation and high-grade regional metamorphism that folded the country rock and the batholith contact along west-northwest and north-northwest axes. Also, smaller satellitic granodiorite bodies tend to conform to the trends of foliation and fold axes in

  4. Hydrology and Flood Profiles of Duck Creek and Jordan Creek Downstream from Egan Drive, Juneau, Alaska

    USGS Publications Warehouse

    Curran, Janet H.

    2007-01-01

    Hydrologic and hydraulic updates for Duck Creek and the lower part of Jordan Creek in Juneau, Alaska, included computation of new estimates of peak streamflow magnitudes and new water-surface profiles for the 10-, 50-, 100-, and 500-year floods. Computations for the 2-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year recurrence interval flood magnitudes for both streams used data from U.S. Geological Survey stream-gaging stations weighted with regional regression equations for southeast Alaska. The study area for the hydraulic model consisted of three channels: Duck Creek from Taku Boulevard near the stream's headwaters to Radcliffe Road near the end of the Juneau International Airport runway, an unnamed tributary to Duck Creek from Valley Boulevard to its confluence with Duck Creek, and Jordan Creek from a pedestrian bridge upstream from Egan Drive to Crest Street at Juneau International Airport. Field surveys throughout the study area provided channel geometry for 206 cross sections, and geometric and hydraulic characteristics for 29 culverts and 15 roadway, driveway, or pedestrian bridges. Hydraulic modeling consisted of application of the U.S. Army Corps of Engineers' Hydrologic Engineering Center River Analysis System (HEC-RAS) for steady-state flow at the selected recurrence intervals using an assumed high tide of 20 feet and roughness coefficients refined by calibration to measured water-surface elevations from a 2- to 5-year flood that occurred on November 21, 2005. Model simulation results identify inter-basin flow from Jordan Creek to the southeast at Egan Drive and from Duck Creek to Jordan Creek downstream from Egan Drive at selected recurrence intervals.

  5. Water-quality appraisal. Mammoth Creek and Hot Creek, Mono County, California

    SciTech Connect

    Setmire, J.G.

    1984-06-01

    A late summer reconnaissance in 1981 and a spring high-flow sampling in 1982 of Mammoth Creek and Hot Creek, located in the Mammoth crest area of the Sierra Nevada, indicated that three water-quality processes were occurring: (1) mineralization; (2) eutrophication; and (3) sedimentation. Limited areas of fecal contamination were also observed. Mineralization due primarily to geothermal springs increased dissolved-solids concentration downstream, which changed the chemical composition of the water. The percentage of calcium decreased gradually, the percentage of magnesium and sodium increased, and the percentage of fluoride, sulfate, and chloride fluctuated, but increased overall. These changes produced water quality in Mammoth Creek similar to that of the springs forming Hot Creek. Twin Lakes and the reach of Hot Creek below the fish hatchery showed evidence of eutrophication. Twin Lakes had floating mats of algae and a high dissolved-oxygen saturation of 147% at a pH of 9.2. Hot Creek had abundant growth of aquatic vascular plants and algae, dissolved-oxygen saturations ranging from 65% to 200%, algal growth potential of 30 milligrams per liter, nitrate concentration of 0.44 milligram per liter, and phosphate concentration of 0.157 milligram per liter. Sediment deposition was determined from detailed observations of bed-material composition, which showed that fine material was deposited at Sherwin Creek Road and downstream. Fecal contamination was indicated by fecal-coliform bacteria counts of 250 colonies per 100 milliliters and fecal-streptococcal bacteria counts greater than 1000 colonies per 100 milliliters. Although bacterial sampling was sporadic and incomplete, it did indicate adverse effects on water quality for the following beneficial uses that have been identified for Mammoth Creek and Hot Creek: (1) municipal supply; (2) cold-water habitat; and (3) contact and noncontact water recreation. 6 refs., 15 figs., 15 tabs.

  6. Quality of water and time-of-travel in Bakers Creek near Clinton, Mississippi. [Bakers Creek

    SciTech Connect

    Kalkhoff, S.J.

    1982-01-01

    A short-term intensive quality-of-water study was conducted during a period of generally low streamflow in Bakers Creek and its tributary, Lindsey Creek, near Clinton, Mississippi. During the September 15-18, 1980 study, dissolved oxygen concentrations in Bakers Creek were less than 5 milligrams per liter. The specific conductance, 5-day biochemical oxygen demand, nutrient concentrations, and bacteria densities in Bakers Creek decreased downstream through the study reach. The mean specific conductance decreased from 670 to 306 microhms per centimeter. The 5-day biochemical oxygen demand decreased from 19 to 2.8 milligrams per liter. The mean total nitrogen and phosphorous concentrations decreased from 10 and 7.1 to 1.0 and 0.87 milligram per litter, respectively. The maximum fecal bacteria decreased from 7200 to 400 colonies per 100 milliliter. The concentrations of mercury, iron, and manganese in a sample collected at the downstream site exceeded recommended limits. Diazinon and 2,4-D were also present in the water. A bottom material sample contained DDD (2.5 micrograms per kilogram), DDE (2.7 micrograms per kilogram), and DDT (.3 micrograms per kilogram). The tributary inflow from Lindsey Creek did not improve the water quality of Bakers Creek. The dissolved oxygen concentrations were generally less than 5.0 milligrams per liter at the sampling site on Lindsey Creek. The 5-day biochemical oxygen demand, the mean specific conductance, and fecal coliform densities were greater in the tributary than at the downstream site on Bakers Creek. The average rate of travel through a 1.8-mile reach of Bakers Creek was 0.06 foot per second or 0.04 miles per hour. 6 references, 9 figures, 2 tables.

  7. 1. EXTERIOR OVERVIEW OF SOUTH END OF RUSH CREEK POWERHOUSE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. EXTERIOR OVERVIEW OF SOUTH END OF RUSH CREEK POWERHOUSE RESIDENTIAL COMPLEX SHOWING THE RUSH CREEK POWERHOUSE AT PHOTO RIGHT, BUILDING 106 NEXT TO THE POWERHOUSE AT PHOTO CENTER, BUILDING 103 AT UPPER PHOTO LEFT, AND BUILDING 104 ABOVE BUILDING 106 PARTIALLY OBSCURED BEHIND TREE AT UPPER PHOTO CENTER. VIEW TO SOUTH. - Rush Creek Hydroelectric System, Worker Cottage, Rush Creek, June Lake, Mono County, CA

  8. 1. OVERVIEW OF EXTREME EAST END OF BIG CREEK TOWN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. OVERVIEW OF EXTREME EAST END OF BIG CREEK TOWN ACROSS POWERHOUSE NO. 2 FOREBAY (POWERHOUSE NO. 1 AFTERBAY). TOWER CARRYING TRANSMISSION LINES FROM POWERHOUSE NO. 1 IS AT PHOTO CENTER. BEHIND TOWER IS BUILDING 103. TO PHOTO LEFT OF BUILDING 103 IS BUILDING 105. VIEW TO NORTH. - Big Creek Hydroelectric System, Big Creek Town, Operator House, Orchard Avenue south of Huntington Lake Road, Big Creek, Fresno County, CA

  9. Flood-inundation maps for Indian Creek and Tomahawk Creek, Johnson County, Kansas, 2014

    USGS Publications Warehouse

    Peters, Arin J.; Studley, Seth E.

    2015-01-01

    Digital flood-inundation maps for a 6.4-mile upper reach of Indian Creek from College Boulevard to the confluence with Tomahawk Creek, a 3.9-mile reach of Tomahawk Creek from 127th Street to the confluence with Indian Creek, and a 1.9-mile lower reach of Indian Creek from the confluence with Tomahawk Creek to just beyond the Kansas/Missouri border at State Line Road in Johnson County, Kansas, were created by the U.S. Geological Survey in cooperation with the city of Overland Park, Kansas. The flood-inundation maps, which can be accessed through the U.S. Geological Survey Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/, depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at the U.S. Geological Survey streamgages on Indian Creek at Overland Park, Kansas; Indian Creek at State Line Road, Leawood, Kansas; and Tomahawk Creek near Overland Park, Kansas. Near real time stages at these streamgages may be obtained on the Web from the U.S. Geological Survey National Water Information System at http://waterdata.usgs.gov/nwis or the National Weather Service Advanced Hydrologic Prediction Service at http://water.weather.gov/ahps/, which also forecasts flood hydrographs at these sites.Flood profiles were computed for the stream reaches by means of a one-dimensional step-backwater model. The model was calibrated for each reach by using the most current stage-discharge relations at the streamgages. The hydraulic models were then used to determine 15 water-surface profiles for Indian Creek at Overland Park, Kansas; 17 water-surface profiles for Indian Creek at State Line Road, Leawood, Kansas; and 14 water-surface profiles for Tomahawk Creek near Overland Park, Kansas, for flood stages at 1-foot intervals referenced to the streamgage datum and ranging from bankfull to the next interval above the 0.2-percent annual exceedance probability flood level (500-year recurrence interval). The

  10. Selected hydrologic data for Fountain Creek and Monument Creek basins, east-central Colorado

    USGS Publications Warehouse

    Kuhn, Gerhard; Ortiz, Roderick F.

    1989-01-01

    Selected hydrologic data were collected during 1986, 1987, and 1988 by the U.S. Geological Survey for the Fountain Creek and Monument Creek basins, east-central Colorado. The data were obtained as part of a study to determine the present and projected effects of wastewater discharges on the two creeks. The data, which are available for 129 surface-water sites, include: (1) About 1,100 water quality analyses; (2) about 420 measurements of discharge, (3) characteristics of about 50 dye clouds associated with measurements of traveltime and reaeration , and (4) about 360 measurements of channel geometry. (USGS)

  11. Radiometric ages of the Fire Clay tonstein [Pennsylvanian (Upper Carboniferous), Westphalian, Duckmantian]: A comparison of U-Pb zircon single-crystal ages and 40Ar/39Ar sanidine single-crystal plateau ages

    USGS Publications Warehouse

    Lyons, P.C.; Krogh, T.E.; Kwok, Y.Y.; Davis, D.W.; Outerbridge, W.F.; Evans, H.T., Jr.

    2006-01-01

    The Fire Clay tonstein [Pennsylvanian (Upper Carboniferous), Westphalian Series, Duckmantian Stage]-a kaolinized, volcanic-ash deposit occurring in Kentucky, West Virginia, Tennessee, and Virginia-is the most widespread bed in the Middle Pennsylvanian of the central Appalachian basin, USA. A concordant single-crystal U-Pb zircon datum for this tonstein gives a 206Pb/238U age of 314.6 ?? 0.9 Ma (2??). This age is in approximate agreement with a mean sanidine plateau age of 311.5 ?? 1.3 Ma (1??, n = 11) for the Fire Clay tonstein. The difference between the two ages may be due to bias between the 40K and 238U decay constants and other factors. The age of the Fire Clay tonstein has important implications for Duckmantian Stage (Westphalian Series) sedimentation rates, correlations with the Westphalian Series of Europe, Middle Pennsylvanian volcanic events, and the late Paleozoic time scale. ?? 2006 Elsevier B.V. All rights reserved.

  12. Ar-40/Ar-39 ages of Meishan Bed 25 sanidine and igneous intrusions from the Siberian platform compared: implications for the timing of gas emissions and the End-Permian extinction

    NASA Astrophysics Data System (ADS)

    Storey, M.; Reichow, M. K.; Saunders, A. D.

    2013-12-01

    The end-Permian mass extinction wiped out nearly all life on our planet. The cause for this cataclysmic event and whether this appeared as a double extinction is a matter of current debate. The most favoured candidate is volatile release from either magmatic degassing directly or induced by interaction between magmas and volatile bearing deposits. Release of volatiles during thermal metamorphism and assimilation of coal and evaporite deposits which are widespread on the Siberian platform following igneous intrusion has been proposed as a major cause of the environmental and extinction event at the end of the Permian, with venting of carbon gases and halocarbons to the atmosphere leading to global warming and atmospheric ozone depletion (Svensen et al., 2009). To meaningfully examine this proposed causality requires precise dating of the Siberian intrusions at the ';Earthtime' goal of × 0.1 % or better. Here we present preliminary results from Ar-40/Ar-39 step heating experiments on plagioclase and biotite from Siberian basin intrusions and compare the data with published and new Ar-40/Ar-39 sanidine ages for Bed 25 from the global section and Permian-Triassic boundary stratotype at Meishan, China. REFERENCES H. Svensen et al., Siberian gas venting and the end-Permian environmental crisis, Earth and Planetary Science Letters, volume 277, 490-500, 200

  13. 78 FR 28897 - Lost Creek ISR, LLC, Lost Creek Uranium In-Situ Recovery Project; Sweetwater County, Wyoming

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-16

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Lost Creek ISR, LLC, Lost Creek Uranium In-Situ Recovery Project; Sweetwater County, Wyoming AGENCY: Nuclear Regulatory Commission. ACTION: Environmental assessment and finding of no...

  14. 78 FR 37474 - Radio Broadcasting Services; Dove Creek, Colorado

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-21

    ... COMMISSION 47 CFR Part 73 Radio Broadcasting Services; Dove Creek, Colorado AGENCY: Federal Communications..., allots FM Channel 229C3 as a first local transmission service at Dove Creek, Colorado. Channel 229C3 can be allotted at Dove Creek, consistent with the minimum distance separation requirements of...

  15. 77 FR 75946 - Radio Broadcasting Services; Dove Creek, CO

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-26

    ... COMMISSION 47 CFR Part 73 . Radio Broadcasting Services; Dove Creek, CO AGENCY: Federal Communications... 229C3 as a first local service at Dove Creek, Colorado. Channel 229C3 can be allotted at Dove Creek... Sec. 73.202 2. Section 73.202(b), the Table of FM Allotments under Colorado, is amended by adding...

  16. 75 FR 8036 - Monitor-Hot Creek Rangeland Project

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-23

    ... Forest Service Monitor-Hot Creek Rangeland Project AGENCY: Forest Service, USDA. ACTION: Notice of intent... continued livestock grazing ] within the Monitor-Hot Creek Rangeland Project area. The analysis will... conditions within the Monitor-Hot Creek Rangeland Project area towards desired conditions. The project...

  17. 1. EXTERIOR OVERVIEW SHOWING BISHOP CREEK PLANT 4 RESIDENTIAL COMPLEX. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. EXTERIOR OVERVIEW SHOWING BISHOP CREEK PLANT 4 RESIDENTIAL COMPLEX. BUILDING 113 IS VISIBLE AT RIGHT PHOTO CENTER. PLANT 5 INTAKE DAM AT PHOTO LEFT. VIEW TO WEST. - Bishop Creek Hydroelectric System, Plant 4, Worker Cottage, Bishop Creek, Bishop, Inyo County, CA

  18. 1. EXTERIOR OVERVIEW SHOWING BISHOP CREEK PLANT 4 RESIDENTIAL COMPLEX. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. EXTERIOR OVERVIEW SHOWING BISHOP CREEK PLANT 4 RESIDENTIAL COMPLEX. ROOF OF BUILDING 105 IS VISIBLE IN UPPER PHOTO CENTER. PLANT 5 INTAKE DAM AT PHOTO LEFT. VIEW TO WEST. - Bishop Creek Hydroelectric System, Plant 4, Worker Cottage, Bishop Creek, Bishop, Inyo County, CA

  19. 1. EXTERIOR OVERVIEW OF NORTH END OF RUSH CREEK POWERHOUSE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. EXTERIOR OVERVIEW OF NORTH END OF RUSH CREEK POWERHOUSE RESIDENTIAL COMPLEX SHOWING BUILDING 108 AT PHOTO RIGHT AND BUILDING 105 AT PHOTO CENTER BEHIND SWITCHRACKS AND TREE. POWERHOUSE IS AT EXTREME PHOTO LEFT. VIEW TO WEST. - Rush Creek Hydroelectric System, Worker Cottage, Rush Creek, June Lake, Mono County, CA

  20. 1. EXTERIOR OVERVIEW SHOWING BISHOP CREEK PLANT 4 RESIDENTIAL COMPLEX. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. EXTERIOR OVERVIEW SHOWING BISHOP CREEK PLANT 4 RESIDENTIAL COMPLEX. BUILDING 122 IS VISIBLE AT PHOTO CENTER. PLANT 5 INTAKE DAM AT PHOTO LEFT. VIEW TO WEST. - Bishop Creek Hydroelectric System, Plant 4, Worker Cottage, Bishop Creek, Bishop, Inyo County, CA

  1. 33 CFR 110.72 - Blackhole Creek, Md.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... tip of an unnamed island located 0.16 mile upstream from the mouth of the creek approximately 660 feet to the west shore of the creek; northwest of a line ranging from the southwesterly tip of the island toward the point of land on the west shore of the creek immediately southwest thereof; and north of...

  2. 33 CFR 110.72 - Blackhole Creek, Md.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... tip of an unnamed island located 0.16 mile upstream from the mouth of the creek approximately 660 feet to the west shore of the creek; northwest of a line ranging from the southwesterly tip of the island toward the point of land on the west shore of the creek immediately southwest thereof; and north of...

  3. 33 CFR 110.72 - Blackhole Creek, Md.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... tip of an unnamed island located 0.16 mile upstream from the mouth of the creek approximately 660 feet to the west shore of the creek; northwest of a line ranging from the southwesterly tip of the island toward the point of land on the west shore of the creek immediately southwest thereof; and north of...

  4. 33 CFR 110.72 - Blackhole Creek, Md.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... tip of an unnamed island located 0.16 mile upstream from the mouth of the creek approximately 660 feet to the west shore of the creek; northwest of a line ranging from the southwesterly tip of the island toward the point of land on the west shore of the creek immediately southwest thereof; and north of...

  5. 33 CFR 110.72 - Blackhole Creek, Md.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... tip of an unnamed island located 0.16 mile upstream from the mouth of the creek approximately 660 feet to the west shore of the creek; northwest of a line ranging from the southwesterly tip of the island toward the point of land on the west shore of the creek immediately southwest thereof; and north of...

  6. Detail view of the Ten Mile Creek Bridge joint between ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail view of the Ten Mile Creek Bridge joint between the tied arch span and the approach span, view looking east at southwest corner of bridge. - Ten Mile Creek Bridge, Spanning Ten Mile Creek on Oregon Coast Highway, Yachats, Lincoln County, OR

  7. 33 CFR 117.745 - Rancocas River (Creek).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Rancocas River (Creek). 117.745... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.745 Rancocas River (Creek). (a) The following requirements apply to all bridges across the Rancocas River (Creek): (1) Public vessels of...

  8. 33 CFR 117.745 - Rancocas River (Creek).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Rancocas River (Creek). 117.745... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.745 Rancocas River (Creek). (a) The following requirements apply to all bridges across the Rancocas River (Creek): (1) Public vessels of...

  9. View looking Eastnortheast at French Creek trestle, which appears at ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View looking Eastnortheast at French Creek trestle, which appears at left center of frame. Bridge in foreground is west entrance to abandoned Phoenix iron works. - Pennsylvania Railroad, French Creek Trestle, Spanning French Creek, north of Paradise Street, Phoenixville, Chester County, PA

  10. Factors affecting distribution of wood, detritus, and sediment in headwater streams draining managed young-growth red alder - Conifer forests in southeast Alaska

    USGS Publications Warehouse

    Gomi, T.; Johnson, A.C.; Deal, R.L.; Hennon, P.E.; Orlikowska, E.H.; Wipfli, M.S.

    2006-01-01

    Factors (riparian stand condition, management regimes, and channel properties) affecting distributions of wood, detritus (leaves and branches), and sediment were examined in headwater streams draining young-growth red alder (Alnus rubra Bong.) - conifer riparian forests (40 years old) remained in channels and provided sites for sediment and organic matter storage. Despite various alder-conifer mixtures and past harvesting effects, the abundance of large wood, fine wood, and detritus accumulations significantly decreased with increasing channel bank-full width (0.5-3.5 m) along relatively short channel distances (up to 700 m). Changes in wood, detritus, and sediment accumulations together with changes in riparian stand characteristics create spatial and temporal variability of in-channel conditions in headwater systems. A component of alder within young-growth riparian forests may benefit both wood production and biological recovery in disturbed headwater stream channels. ?? 2006 NRC.

  11. Ross operation in children and young adults: the Alder Hey case series

    PubMed Central

    Raja, Shahzad Gull; Pozzi, Marco

    2004-01-01

    Background The ideal prosthesis for aortic valve replacement in children and young adults has not been found yet. In recent years there has been a renewed interest in the replacement of aortic valve with the pulmonary autograft owing to its advantages of lack of anticoagulation, potential for growth and excellent haemodynamic performance. The purpose of this study was to review our institutional experience at Alder Hey hospital with the Ross procedure in children and young adults. Methods From November 1996 to September 2003, 38 patients (mean age, 13.1 ± 5.7 years) underwent the Ross procedure for various aortic valve diseases using the root replacement technique. Clinical and echocardiographic follow-up was performed early (within 30 days), 3 to 6 months, and yearly after surgery. Medical records of all patients were reviewed retrospectively. Results There was 1 perioperative death. The patients were followed-up for a median interval of 36 months and up to 7 years. One patient died 3 years after surgery secondary to ventricular arrhythmia with overall mortality of 5.3%. Actuarial survival at 7 years was 94 ± 2.5% and there was 100% freedom from reoperation for autograft valve dysfunction or any other cause. Balloon dilatation was required in 2 patients for pulmonary homograft stenosis. The haemodynamics at the latest follow-up were also similar to those at the time of discharge after surgery. There was no progression in the degree of aortic regurgitation for 11 patients with trivial and 3 with mild regurgitation. Conclusion Our experience demonstrates that Ross operation is an attractive option for aortic valve replacement in children and young adults. Not only can the operation be accomplished with a low operative risk but the valve function stays normal over a long period of time with minimal alteration in lifestyle and no need for repeated operations to replace the valve as a result of somatic growth of the children. PMID:15096281

  12. Harnessing the bioorthogonal inverse electron demand Diels-Alder cycloaddition for pretargeted PET imaging.

    PubMed

    Reiner, Thomas; Lewis, Jason S; Zeglis, Brian M

    2015-01-01

    Due to their exquisite affinity and specificity, antibodies have become extremely promising vectors for the delivery of radioisotopes to cancer cells for PET imaging. However, the necessity of labeling antibodies with radionuclides with long physical half-lives often results in high background radiation dose rates to non-target tissues. In order to circumvent this issue, we have employed a pretargeted PET imaging strategy based on the inverse electron demand Diels-Alder cycloaddition reaction. The methodology decouples the antibody from the radioactivity and thus exploits the positive characteristics of antibodies, while eschewing their pharmacokinetic drawbacks. The system is composed of four steps: (1) the injection of a mAb-trans-cyclooctene (TCO) conjugate; (2) a localization time period during which the antibody accumulates in the tumor and clears from the blood; (3) the injection of the radiolabeled tetrazine; and (4) the in vivo click ligation of the components followed by the clearance of excess radioligand. In the example presented in the work at hand, a (64)Cu-NOTA-labeled tetrazine radioligand and a trans-cyclooctene-conjugated humanized antibody (huA33) were successfully used to delineate SW1222 colorectal cancer tumors with high tumor-to-background contrast. Further, the pretargeting methodology produces high quality images at only a fraction of the radiation dose to non-target tissue created by radioimmunoconjugates directly labeled with (64)Cu or (89)Zr. Ultimately, the modularity of this protocol is one of its greatest assets, as the trans-cyclooctene moiety can be appended to any non-internalizing antibody, and the tetrazine can be attached to a wide variety of radioisotopes. PMID:25742199

  13. QM/QM' Direct Molecular Dynamics of Water-Accelerated Diels-Alder Reaction.

    PubMed

    Liu, Fengjiao; Yang, Zhongyue; Mei, Ye; Houk, K N

    2016-07-01

    A QM/QM' direct molecular dynamics study of a water-accelerated Diels-Alder reaction in aqueous solution is reported. Cyclopentadiene and methyl vinyl ketone are known to react faster in water than in nonpolar solvents. We have explored how polarization of water molecules afforded by PM3 influences the nature of the transition state, and the reaction dynamics. We compare the results with previous studies on QM/MM and QM/MM+3QM water simulations from our laboratory. Transition state sampling in vacuum PM3 water boxes indicates that the asynchronicity is 0.54 Å in QM/QM', as compared to 0.48 Å in QM/MM, and 0.54 Å in QM/MM+3QM water. The mean time gap between the formation of two C-C bonds is 19 fs for QM/QM', compared to 20 fs for QM/MM, and 25 fs for QM/MM+3QM water. The samplings and time gaps are qualitatively consistent, indicating that water polarization is not significant in sampling and dynamics of bonding changes. The dynamics of hydrogen bonding between reacting molecules and water molecules was also analyzed. From reactants to transition states, H-bond shortening is 0.4 Å by QM/QM', while only 0.15 Å for QM/MM and QM/MM+3QM water. From reactants to transition states, the mean value of the H-bond angle increases by 19° in QM/QM', but only 4° in QM/MM, and 10° in QM/MM+3QM water. These suggest that water polarization is essential for the correct representation of dynamical formation of hydrogen bonds in the transition state by water reorientation. QM/QM' overestimates the hydrogen bonding enhancement because of its underestimation of neutral hydrogen bonding within the reactants, a general deficiency of PM3. PMID:27092967

  14. Harnessing the Bioorthogonal Inverse Electron Demand Diels-Alder Cycloaddition for Pretargeted PET Imaging

    PubMed Central

    Lewis, Jason S.

    2015-01-01

    Due to their exquisite affinity and specificity, antibodies have become extremely promising vectors for the delivery of radioisotopes to cancer cells for PET imaging. However, the necessity of labeling antibodies with radionuclides with long physical half-lives often results in high background radiation dose rates to non-target tissues. In order to circumvent this issue, we have employed a pretargeted PET imaging strategy based on the inverse electron demand Diels-Alder cycloaddition reaction. The methodology decouples the antibody from the radioactivity and thus exploits the positive characteristics of antibodies, while eschewing their pharmacokinetic drawbacks. The system is composed of four steps: (1) the injection of a mAb-trans-cyclooctene (TCO) conjugate; (2) a localization time period during which the antibody accumulates in the tumor and clears from the blood; (3) the injection of the radiolabeled tetrazine; and (4) the in vivo click ligation of the components followed by the clearance of excess radioligand. In the example presented in the work at hand, a 64Cu-NOTA-labeled tetrazine radioligand and a trans-cyclooctene-conjugated humanized antibody (huA33) were successfully used to delineate SW1222 colorectal cancer tumors with high tumor-to-background contrast. Further, the pretargeting methodology produces high quality images at only a fraction of the radiation dose to non-target tissue created by radioimmunoconjugates directly labeled with 64Cu or 89Zr. Ultimately, the modularity of this protocol is one of its greatest assets, as the trans-cyclooctene moiety can be appended to any non-internalizing antibody, and the tetrazine can be attached to a wide variety of radioisotopes. PMID:25742199

  15. Novel Diels-Alder based self-healing epoxies for aerospace composites

    NASA Astrophysics Data System (ADS)

    Coope, T. S.; Turkenburg, D. H.; Fischer, H. R.; Luterbacher, R.; van Bracht, H.; Bond, I. P.

    2016-08-01

    Epoxy resins containing Diels-Alder (DA) furan and maleimide moieties are presented with the capability to self-heal after exposure to an external heat source. A conventional epoxy amine system has been combined with furfuryl and maleimide functional groups in a two-step process, to avoid major side-reactions, and the concentration of a thermo-reversibly binding cross-linker was considered to balance thermoset and thermoplastic behaviours, and the subsequent self-healing performance. In the context of self-repair technologies an inbuilt ‘intrinsic’ self-healing system is deemed favourable as the healing agent can be placed in known ‘hot spot’ regions (i.e. skin-stringer run outs, ply drops and around drilled holes) where operational damage predominately occurs in load bearing aerospace structures. In this study, the mechanical and self-healing performance of furan functionalised epoxy resins containing varying amounts (10, 20, 30 or 40 pph) of bismaleimide were investigated using a bulk epoxy polymer tapered double cantilever beam test specimen geometry. Two forms, a thin film and a bulk material, were evaluated to account for future integration methods into fibre reinforced polymer (FRP) composites. The highest healing efficiency, with respect to the obtained initial load value, was observed from the 20 pph bulk material derivative. The polymers were successful in achieving consistent multiple (three) healing cycles when heated at 150 °C for 5 min. This novel investigated DA material exhibits favourable processing characteristics for FRP composites as preliminary studies have shown successful coextrution with reinforcing fibres to form free standing films and dry fibre impregnation.

  16. The mechanism of the retro-Diels-Alder reaction in 4-vinylcyclohexene cation radical

    NASA Astrophysics Data System (ADS)

    Pancíř, J.; Tureček, F.

    1984-06-01

    Butadiene cation radicals are produced symmetrically from the ring and side-chain of the vinylcyclohexene cation radical near the onset of the fragmentation. The appearance energies of C 4H 6+- and C 4H 2D 4+- from (3,3,6,6-D 4)vinylcyclohex ene were measured as 11.07 ± 0.05 and 11.06 ± 0.06 eV, respectively. This sets the barrier to retro-Diels-Alder decomposition at 1140 kJ mol -1 above the energy of 1 and 44 kJ mol -1 above the thermochemical threshold corresponding to C 4H 6+- + C 4H 6. Topological molecular orbital calculations indicate that this lowest-energy path involves a sequential rupture of the C 3C 4 and C 5C 6 bonds, with a calculated barrier of 211 kJ mol -1. The second, two-step reaction channel proceeds by subsequent fission of the C 5C 6 and C 3C 4 bonds with a barrier of 299 kJ mol -1. This channel is found experimentally as a break on the ionization efficiency curve at 12.1 eV. Both the supra-supra and the supra-antara pericyclic reactions go through energy maxima and are therefore forbidden. The supra-supra process is the most favorable route for decomposition from the first excited state, the activation energy being 333 kJ mol -1. The preference for the two-step mechanism is due to hyperconjugative stabilization of intermediate molecular configurations.

  17. Actinorhizal Alder Phytostabilization Alters Microbial Community Dynamics in Gold Mine Waste Rock from Northern Quebec: A Greenhouse Study

    PubMed Central

    Callender, Katrina L.; Roy, Sébastien; Khasa, Damase P.; Whyte, Lyle G.; Greer, Charles W.

    2016-01-01

    Phytotechnologies are rapidly replacing conventional ex-situ remediation techniques as they have the added benefit of restoring aesthetic value, important in the reclamation of mine sites. Alders are pioneer species that can tolerate and proliferate in nutrient-poor, contaminated environments, largely due to symbiotic root associations with the N2-fixing bacteria, Frankia and ectomycorrhizal (ECM) fungi. In this study, we investigated the growth of two Frankia-inoculated (actinorhizal) alder species, A. crispa and A. glutinosa, in gold mine waste rock from northern Quebec. Alder species had similar survival rates and positively impacted soil quality and physico-chemical properties in similar ways, restoring soil pH to neutrality and reducing extractable metals up to two-fold, while not hyperaccumulating them into above-ground plant biomass. A. glutinosa outperformed A. crispa in terms of growth, as estimated by the seedling volume index (SVI), and root length. Pyrosequencing of the bacterial 16S rRNA gene for bacteria and the ribosomal internal transcribed spacer (ITS) region for fungi provided a comprehensive, direct characterization of microbial communities in gold mine waste rock and fine tailings. Plant- and treatment-specific shifts in soil microbial community compositions were observed in planted mine residues. Shannon diversity and the abundance of microbes involved in key ecosystem processes such as contaminant degradation (Sphingomonas, Sphingobium and Pseudomonas), metal sequestration (Brevundimonas and Caulobacter) and N2-fixation (Azotobacter, Mesorhizobium, Rhizobium and Pseudomonas) increased over time, i.e., as plants established in mine waste rock. Acetate mineralization and most probable number (MPN) assays showed that revegetation positively stimulated both bulk and rhizosphere communities, increasing microbial density (biomass increase of 2 orders of magnitude) and mineralization (five-fold). Genomic techniques proved useful in investigating

  18. Synthesis of terephthalic acid via Diels-Alder reactions with ethylene and oxidized variants of 5-hydroxymethylfurfural

    PubMed Central

    Pacheco, Joshua J.; Davis, Mark E.

    2014-01-01

    Terephthalic acid (PTA), a monomer in the synthesis of polyethylene terephthalate (PET), is obtained by the oxidation of petroleum-derived p-xylene. There is significant interest in the synthesis of renewable, biomass-derived PTA. Here, routes to PTA starting from oxidized products of 5-hydroxymethylfurfural (HMF) that can be produced from biomass are reported. These routes involve Diels-Alder reactions with ethylene and avoid the hydrogenation of HMF to 2,5-dimethylfuran. Oxidized derivatives of HMF are reacted with ethylene over solid Lewis acid catalysts that do not contain strong Brønsted acids to synthesize intermediates of PTA and its equally important diester, dimethyl terephthalate (DMT). The partially oxidized HMF, 5-(hydroxymethyl)furoic acid (HMFA), is reacted with high pressure ethylene over a pure-silica molecular sieve containing framework tin (Sn-Beta) to produce the Diels-Alder dehydration product, 4-(hydroxymethyl)benzoic acid (HMBA), with 31% selectivity at 61% HMFA conversion after 6 h at 190 °C. If HMFA is protected with methanol to form methyl 5-(methoxymethyl)furan-2-carboxylate (MMFC), MMFC can react with ethylene in the presence of Sn-Beta for 2 h to produce methyl 4-(methoxymethyl)benzenecarboxylate (MMBC) with 46% selectivity at 28% MMFC conversion or in the presence of a pure-silica molecular sieve containing framework zirconium (Zr-Beta) for 6 h to produce MMBC with 81% selectivity at 26% MMFC conversion. HMBA and MMBC can then be oxidized to produce PTA and DMT, respectively. When Lewis acid containing mesoporous silica (MCM-41) and amorphous silica, or Brønsted acid containing zeolites (Al-Beta), are used as catalysts, a significant decrease in selectivity/yield of the Diels-Alder dehydration product is observed. PMID:24912153

  19. Synthesis of terephthalic acid via Diels-Alder reactions with ethylene and oxidized variants of 5-hydroxymethylfurfural.

    PubMed

    Pacheco, Joshua J; Davis, Mark E

    2014-06-10

    Terephthalic acid (PTA), a monomer in the synthesis of polyethylene terephthalate (PET), is obtained by the oxidation of petroleum-derived p-xylene. There is significant interest in the synthesis of renewable, biomass-derived PTA. Here, routes to PTA starting from oxidized products of 5-hydroxymethylfurfural (HMF) that can be produced from biomass are reported. These routes involve Diels-Alder reactions with ethylene and avoid the hydrogenation of HMF to 2,5-dimethylfuran. Oxidized derivatives of HMF are reacted with ethylene over solid Lewis acid catalysts that do not contain strong Brønsted acids to synthesize intermediates of PTA and its equally important diester, dimethyl terephthalate (DMT). The partially oxidized HMF, 5-(hydroxymethyl)furoic acid (HMFA), is reacted with high pressure ethylene over a pure-silica molecular sieve containing framework tin (Sn-Beta) to produce the Diels-Alder dehydration product, 4-(hydroxymethyl)benzoic acid (HMBA), with 31% selectivity at 61% HMFA conversion after 6 h at 190 °C. If HMFA is protected with methanol to form methyl 5-(methoxymethyl)furan-2-carboxylate (MMFC), MMFC can react with ethylene in the presence of Sn-Beta for 2 h to produce methyl 4-(methoxymethyl)benzenecarboxylate (MMBC) with 46% selectivity at 28% MMFC conversion or in the presence of a pure-silica molecular sieve containing framework zirconium (Zr-Beta) for 6 h to produce MMBC with 81% selectivity at 26% MMFC conversion. HMBA and MMBC can then be oxidized to produce PTA and DMT, respectively. When Lewis acid containing mesoporous silica (MCM-41) and amorphous silica, or Brønsted acid containing zeolites (Al-Beta), are used as catalysts, a significant decrease in selectivity/yield of the Diels-Alder dehydration product is observed. PMID:24912153

  20. Actinorhizal Alder Phytostabilization Alters Microbial Community Dynamics in Gold Mine Waste Rock from Northern Quebec: A Greenhouse Study.

    PubMed

    Callender, Katrina L; Roy, Sébastien; Khasa, Damase P; Whyte, Lyle G; Greer, Charles W

    2016-01-01

    Phytotechnologies are rapidly replacing conventional ex-situ remediation techniques as they have the added benefit of restoring aesthetic value, important in the reclamation of mine sites. Alders are pioneer species that can tolerate and proliferate in nutrient-poor, contaminated environments, largely due to symbiotic root associations with the N2-fixing bacteria, Frankia and ectomycorrhizal (ECM) fungi. In this study, we investigated the growth of two Frankia-inoculated (actinorhizal) alder species, A. crispa and A. glutinosa, in gold mine waste rock from northern Quebec. Alder species had similar survival rates and positively impacted soil quality and physico-chemical properties in similar ways, restoring soil pH to neutrality and reducing extractable metals up to two-fold, while not hyperaccumulating them into above-ground plant biomass. A. glutinosa outperformed A. crispa in terms of growth, as estimated by the seedling volume index (SVI), and root length. Pyrosequencing of the bacterial 16S rRNA gene for bacteria and the ribosomal internal transcribed spacer (ITS) region for fungi provided a comprehensive, direct characterization of microbial communities in gold mine waste rock and fine tailings. Plant- and treatment-specific shifts in soil microbial community compositions were observed in planted mine residues. Shannon diversity and the abundance of microbes involved in key ecosystem processes such as contaminant degradation (Sphingomonas, Sphingobium and Pseudomonas), metal sequestration (Brevundimonas and Caulobacter) and N2-fixation (Azotobacter, Mesorhizobium, Rhizobium and Pseudomonas) increased over time, i.e., as plants established in mine waste rock. Acetate mineralization and most probable number (MPN) assays showed that revegetation positively stimulated both bulk and rhizosphere communities, increasing microbial density (biomass increase of 2 orders of magnitude) and mineralization (five-fold). Genomic techniques proved useful in investigating

  1. Can We Use Tree Rings of Black Alder to Reconstruct Lake Levels? A Case Study for the Mecklenburg Lake District, Northeastern Germany

    PubMed Central

    van der Maaten, Ernst; van der Maaten-Theunissen, Marieke; Buras, Allan; Scharnweber, Tobias; Simard, Sonia; Kaiser, Knut; Lorenz, Sebastian; Wilmking, Martin

    2015-01-01

    In this study, we explore the potential to reconstruct lake-level (and groundwater) fluctuations from tree-ring chronologies of black alder (Alnus glutinosa L.) for three study lakes in the Mecklenburg Lake District, northeastern Germany. As gauging records for lakes in this region are generally short, long-term reconstructions of lake-level fluctuations could provide valuable information on past hydrological conditions, which, in turn, are useful to assess dynamics of climate and landscape evolution. We selected black alder as our study species as alder typically thrives as riparian vegetation along lakeshores. For the study lakes, we tested whether a regional signal in lake-level fluctuations and in the growth of alder exists that could be used for long-term regional hydrological reconstructions, but found that local (i.e. site-specific) signals in lake level and tree-ring chronologies prevailed. Hence, we built lake/groundwater-level reconstruction models for the three study lakes individually. Two sets of models were considered based on (1) local tree-ring series of black alder, and (2) site-specific Standardized Precipitation Evapotranspiration Indices (SPEI). Although the SPEI-based models performed statistically well, we critically reflect on the reliability of these reconstructions, as SPEI cannot account for human influence. Tree-ring based reconstruction models, on the other hand, performed poor. Combined, our results suggest that, for our study area, long-term regional reconstructions of lake-level fluctuations that consider both recent and ancient (e.g., archaeological) wood of black alder seem extremely challenging, if not impossible. PMID:26317768

  2. Can We Use Tree Rings of Black Alder to Reconstruct Lake Levels? A Case Study for the Mecklenburg Lake District, Northeastern Germany.

    PubMed

    van der Maaten, Ernst; van der Maaten-Theunissen, Marieke; Buras, Allan; Scharnweber, Tobias; Simard, Sonia; Kaiser, Knut; Lorenz, Sebastian; Wilmking, Martin

    2015-01-01

    In this study, we explore the potential to reconstruct lake-level (and groundwater) fluctuations from tree-ring chronologies of black alder (Alnus glutinosa L.) for three study lakes in the Mecklenburg Lake District, northeastern Germany. As gauging records for lakes in this region are generally short, long-term reconstructions of lake-level fluctuations could provide valuable information on past hydrological conditions, which, in turn, are useful to assess dynamics of climate and landscape evolution. We selected black alder as our study species as alder typically thrives as riparian vegetation along lakeshores. For the study lakes, we tested whether a regional signal in lake-level fluctuations and in the growth of alder exists that could be used for long-term regional hydrological reconstructions, but found that local (i.e. site-specific) signals in lake level and tree-ring chronologies prevailed. Hence, we built lake/groundwater-level reconstruction models for the three study lakes individually. Two sets of models were considered based on (1) local tree-ring series of black alder, and (2) site-specific Standardized Precipitation Evapotranspiration Indices (SPEI). Although the SPEI-based models performed statistically well, we critically reflect on the reliability of these reconstructions, as SPEI cannot account for human influence. Tree-ring based reconstruction models, on the other hand, performed poor. Combined, our results suggest that, for our study area, long-term regional reconstructions of lake-level fluctuations that consider both recent and ancient (e.g., archaeological) wood of black alder seem extremely challenging, if not impossible. PMID:26317768

  3. Design and synthesis of polycyclic sulfones via Diels–Alder reaction and ring-rearrangement metathesis as key steps

    PubMed Central

    Gunta, Rama

    2015-01-01

    Summary Here, we describe a new and simple synthetic strategy to various polycyclic sulfones via Diels–Alder reaction and ring-rearrangement metathesis (RRM) as the key steps. This approach delivers tri- and tetracyclic sulfones with six (n = 1), seven (n = 2) or eight-membered (n = 3) fused-ring systems containing trans-ring junctions unlike the conventional all cis-ring junctions generally obtained during the RRM sequence. Interestingly the starting materials used are simple and commercially available. PMID:26425192

  4. Nitroso Diels-Alder (NDA) Reaction as an Efficient Tool for the Functionalization of Diene-Containing Natural Products

    PubMed Central

    Carosso, Serena; Miller, Marvin J.

    2014-01-01

    This review describes the use of nitroso Diels-Alder reactions for the functionalization of complex diene-containing natural products in order to generate libraries of compounds with potential biological activity. The application of this methodology to the structural modification of a series of natural products (thebaine, steroidal dienes, rapamycin, leucomycin, colchicine, isocolchicine and piperine) is discussed using relevant examples from the literature from 1973 onwards. The biological activity of the resulting compounds is also discussed. Additional comments are provided that evaluate the methodology as a useful tool in organic, bioorganic and medicinal chemistry. PMID:25119424

  5. Concise Approach to (ent)-14 β-Hydroxysteroids through Highly Diastereo-/Enantioselective Diels-Alder Reactions.

    PubMed

    Peter, Clovis; Ressault, Blandine; Geoffroy, Philippe; Miesch, Michel

    2016-07-25

    14β-Hydroxysteroids, especially 14β-hydroxyandrostane derivatives are closely related to the cardenolide skeletons. The latter were readily available through highly diastero/enantioselective Diels-Alder (DA) reactions requiring high pressure or Lewis acid activation. Moreover, in the presence of (R)- or (S)-carvone as a chiral dienophile, the DA-reaction takes place under chemodivergent parallel kinetic resolution control affording highly enantiomerically enriched 14β-hydroxysteroid derivatives or the corresponding (ent)-14β-hydroxysteroid derivatives. PMID:27192692

  6. Tandem cross enyne metathesis (CEYM)–intramolecular Diels–Alder reaction (IMDAR). An easy entry to linear bicyclic scaffolds

    PubMed Central

    Miró, Javier; Sánchez-Roselló, María; Sanz, Álvaro; Rabasa, Fernando

    2015-01-01

    Summary A new tandem cross enyne metathesis (CEYM)–intramolecular Diels–Alder reaction (IMDAR) has been carried out. It involves conjugated ketones, esters or amides bearing a remote olefin and aromatic alkynes as the starting materials. The overall process enables the preparation of a small family of linear bicyclic scaffolds in a very simple manner with moderate to good levels of diastereoselectivity. This methodology constitutes one of the few examples that employ olefins differently than ethylene in tandem CEYM–IMDAR protocols. PMID:26425205

  7. 33 CFR 334.240 - Potomac River, Mattawoman Creek and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Potomac River, Mattawoman Creek and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian Head Division, Indian Head, Md. 334... and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian Head Division, Indian Head, Md....

  8. 33 CFR 334.240 - Potomac River, Mattawoman Creek and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Potomac River, Mattawoman Creek and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian Head Division, Indian Head, Md. 334... and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian Head Division, Indian Head, Md....

  9. 33 CFR 334.240 - Potomac River, Mattawoman Creek and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Potomac River, Mattawoman Creek and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian Head Division, Indian Head, Md. 334... and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian Head Division, Indian Head, Md....

  10. 33 CFR 334.240 - Potomac River, Mattawoman Creek and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Potomac River, Mattawoman Creek and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian Head Division, Indian Head, Md. 334... and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian Head Division, Indian Head, Md....

  11. 33 CFR 334.240 - Potomac River, Mattawoman Creek and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Potomac River, Mattawoman Creek and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian Head Division, Indian Head, Md. 334... and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian Head Division, Indian Head, Md....

  12. Copper(II)-catalyzed room temperature aerobic oxidation of hydroxamic acids and hydrazides to acyl-nitroso and azo intermediates, and their Diels-Alder trapping.

    PubMed

    Chaiyaveij, Duangduan; Cleary, Leah; Batsanov, Andrei S; Marder, Todd B; Shea, Kenneth J; Whiting, Andrew

    2011-07-01

    CuCl(2), in the presence of a 2-ethyl-2-oxazoline ligand, is an effective catalyst for the room temperature, aerobic oxidation of hydroxamic acids and hydrazides, to acyl-nitroso and azo dienophiles respectively, which are efficiently trapped in situ via both inter- and intramolecular hetero-Diels-Alder reactions with dienes. Both inter- and intramolecular variants of the Diels-Alder reaction are suitable under the reaction conditions using a variety of solvents. Under the same conditions, an acyl hydrazide was also oxidized to give an acyl-azo dienophile which was trapped intramolecularly by a diene. PMID:21644530

  13. Grieving in the Muscogee Creek Tribe

    ERIC Educational Resources Information Center

    Walker, Andrea C.

    2008-01-01

    A qualitative, collective case study explores grieving in the Muscogee Creek tribe. Data from interviews with 27 participants, all adult members of the tribe, reveal tendencies in patterns of grieving. Commonalities include (a) individual strength and certainty of recovery; (b) focus on giving to others in the family and coping as a family unit;…

  14. Wolf Creek steam line break analysis

    SciTech Connect

    Garrett, T.J.; Neises, G.J. )

    1990-07-01

    The Steamline Break transient results are presented to the Electric Power Research Institute (EPRI) to demonstrate the RETRAN analysis of a PWR steamline break. RETRAN analysis results are compared to the Wolf Creek USAR results to demonstrate the adequacy of plant modeling techniques for the Design Basis Accident Methodology with Multidimensional Effects project coordinated by EPRI. 7 refs., 29 figs., 4 tabs.

  15. Drywell corrosion stopped at Oyster Creek

    SciTech Connect

    Lipford, B.L. ); Flynn, J.C.

    1993-11-01

    This article describes the detection of corrosion on the drywell containment vessel of Oyster Creek Nuclear Plant and the application of a protective coating to repair the drywell. The topics of the article include drywell design features, identification of the problem, initial action, drywell corrosion, failure of cathodic protection, long-term repair, and repair results.

  16. The Last Class at Daniel's Creek.

    ERIC Educational Resources Information Center

    Rice, Russ

    1987-01-01

    Time and modern education caught up with the nine pupils of Daniel's Creek Elementary School, one of the last remaining one-room schoolhouses in Kentucky. The school was closed at the end of the 1986-87 school year by the county school board, after much opposition from a citizen's group. (JMM)

  17. Bereavement Rituals in the Muscogee Creek Tribe

    ERIC Educational Resources Information Center

    Walker, Andrea C.; Balk, David E.

    2007-01-01

    A qualitative, collective case study explores bereavement rituals in the Muscogee Creek tribe. Data from interviews with 27 participants, all adult members of the tribe, revealed consensus on participation in certain bereavement rituals. Common rituals included (a) conducting a wake service the night before burial; (b) never leaving the body alone…

  18. Gold Creek: Preserving an Environmental Studies Center.

    ERIC Educational Resources Information Center

    Brooks, Suzanne

    In response to a Board of Trustees request for information and recommendations concerning the future use of the Gold Creek property owned by the Los Angeles Community College District, this report emphasizes that the use of this site for instructional field experiences enhances the quality of environmental education for the district's diverse…

  19. CAMAS CREEK STUDY, CAMAS COUNTY, IDAHO. 1979

    EPA Science Inventory

    The National Eutrophication Survey on Magic Reservoir determined that Camas Creek in Camas County, Idaho (17040220) contributed roughly 45% of the total phosphorus load and 34% of the total nitrogen load into Magic Reservoir. From this finding, a water quality study was conducte...

  20. Species status of Mill Creek Elliptio

    SciTech Connect

    Davis, G.M.; Mulvey, M.

    1993-12-31

    This report discusses environmental effects of the Savannah River Plant on aqautic populations in Mill Creek and surrounding tributaries. Of particular concern was the status of Elliptio. Genetics and phenotypic characteristics have shown that the current classification system is not adequate for these populations. The appendices characterize genetic variability at different loci, electrophoretic data, allele frequencies, sympatric species, and anatomical characters.

  1. Goodwin Creek Experimental Watershed: A Historical Perspective

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Goodwin Creek Experimental Watershed was established in north central Mississippi by U.S. Congressional action and the U.S. Department of Agriculture National Sedimentation Laboratory has operated the watershed since October, 1981. Since then, the watershed has provided a platform for research ...

  2. OROFINO CREEK STUDY, CLEARWATER COUNTY IDAHO, 1979

    EPA Science Inventory

    In Water Year 1979, a water quality study was conducted on Orofino Creek in Clearwater County, Idaho (17060306) to determine the present condition of the stream and to assess the impact of point and nonpoint sources. The study involved approximately bi-monthly monitoring for the...

  3. 33 CFR 117.745 - Rancocas Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... requirements apply to all bridges across the Rancocas River (Creek): (1) Public vessels of the United States... that any delay in opening the draw span shall not exceed ten minutes. However, if a train moving toward... bridge is given, that train may continue across the bridge and must clear the bridge interlocks...

  4. How Fern Creek Is Beating Goliath

    ERIC Educational Resources Information Center

    Donovan, Margaret; Galatowitsch, Patrick; Hefferin, Keri; Highland, Shanita

    2013-01-01

    The "David" is Fern Creek Elementary, a small urban school in Orlando, Florida, that serves an overwhelmingly disadvantaged student population. The "Goliaths" are the mountains of problems that many inner-city students face--poverty, homelessness, mobility, instability, limited parent involvement, and violent neighborhood…

  5. 33 CFR 117.815 - Westchester Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New York § 117.815 Westchester Creek. The draw of the Bruckner Boulevard/Unionport Bridge, mile 1.7, at the Bronx, New York, shall open on signal if at least a two-hour advance notice is given to the New York City Department of Transportation (NYCDOT)...

  6. 33 CFR 117.815 - Westchester Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New York § 117.815 Westchester Creek. The draw of the Bruckner Boulevard/Unionport Bridge, mile 1.7, at the Bronx, New York, shall open on signal if at least a two-hour advance notice is given to the New York City Department of Transportation (NYCDOT)...

  7. Intensive survey of the bay creek watershed, July 1992

    SciTech Connect

    Short, M.B.; Kelly, T.G.; Hefley, J.E.

    1995-05-01

    During July 1992, the Illinois Environmental Protection Agency conducted an intensive survey of the Bay Creek basin, a fifth order tributary in the Mississippi River North Central Basin. Bay Creek drains approximately 176.4 square miles primarily in Pike and a small portion of Calhoun counties. Four stations were sampled on the Bay Creek main stem and one on Honey Creek. The survey focused on macroinvertebrate communities, fish populations, instream habitat, fish tissue, sediment and water chemistry, and land use as well as a review of ambient water quality data from IEPA station KCA-01 near Nebo, Illinois, as tools to document the biological and chemical status of Bay Creek.

  8. Steel Creek zooplankton: L Lake/Steel Creek Biological Monitoring Program, January 1986--December 1987

    SciTech Connect

    Starkel, W.M.; Chimney, M.J.

    1988-03-01

    The objectives of this portion of the Steel Creek Biological Monitoring Program were to analyze data on macrozooplankton taxonomy and density in the Steel Creek corridor and swamp/delta, and compare the composition of the post-impoundment macrozooplankton community with pre-impoundment conditions and communities from other stream and swamp systems. The data presented in the report cover the period January 1986 through December 1987. Macrozooplankton samples were collected monthly using an 80 ..mu..m mesh net at Stations 275, 280, and 290 in the Steel Creek corridor and Stations 310, 330, 350, and 370 in the Steel Creek delta/swamp. Macrozooplankton taxa richness was highest at the two Steel Creek corridor stations nearest the L-Lake dam (Stations 275 and 280); mean values were 10.6 and 7.2 taxa collected/month in 1986 vs 12.1 and 12.3 taxa collected/month in 1987. The lowest taxa richness occurred at Steel Creek swamp/delta stations; means ranged from 1.9 to 4.2 taxa collected/month during both years.

  9. Pine Creek Ranch, FY 2001 Annual Report.

    SciTech Connect

    Berry, Mark E.

    2001-11-01

    Pine Creek Ranch was purchased in 1999 by the Confederated Tribes of Warm Springs using Bonneville Power Administration Fish and Wildlife Habitat Mitigation funds. The 25,000 acre property will be managed in perpetuity for the benefit of fish and wildlife habitat. Major issues include: (1) Restoring quality spawning and rearing habitat for stealhead. Streams are incised and fish passage barriers exist from culverts and possibly beaver dams. In addition to stealhead habitat, the Tribes are interested in overall riparian recovery in the John Day River system for wildlife habitat, watershed values and other values such as recreation. (2) Future grazing for specific management purposes. Past grazing practices undoubtedly contributed to current unacceptable conditions. The main stem of Pine Creek has already been enrolled in the CREP program administered by the USDA, Natural Resource Conservation Service in part because of the cost-share for vegetation restoration in a buffer portion of old fields and in part because of rental fees that will help the Tribes to pay the property taxes. Grazing is not allowed in the riparian buffer for the term of the contract. (3) Noxious weeds are a major concern. (4) Encroachment by western juniper throughout the watershed is a potential concern for the hydrology of the creek. Mark Berry, Habitat Manager, for the Pine Creek Ranch requested the Team to address the following objectives: (1) Introduce some of the field staff and others to Proper Functioning Condition (PFC) assessments and concepts. (2) Do a PFC assessment on approximately 10 miles of Pine Creek. (3) Offer management recommendations. (4) Provide guidelines for monitoring.

  10. Humus bacteria of Norway spruce stands: plant growth promoting properties and birch, red fescue and alder colonizing capacity.

    PubMed

    Elo; Maunuksela; Salkinoja-Salonen; Smolander; Haahtela

    2000-02-01

    We studied the potential of the humus layer of the Norway spruce stands to supply beneficial rhizobacteria to birch (Betula pendula), alder (Alnus incana) and fescue grass (Festuca rubra), representatives of pioneer vegetation after clear-cutting of the coniferous forest. Axenically grown seedlings of these species were inoculated with the acid spruce humus, pH 3.7-5.3. Actinorhizal propagules, capable of nodulating alder, were present in high density (10(3) g(-1)) in humus of long-term limed plots, whereas plots with nitrogen fertilization contained almost none (

  11. Insight into the informational-structure behavior of the Diels-Alder reaction of cyclopentadiene and maleic anhydride.

    PubMed

    Molina-Espíritu, Moyocoyani; Esquivel, Rodolfo O; Kohout, Miroslav; Angulo, Juan Carlos; Dobado, José A; Dehesa, Jesús S; LópezRosa, Sheila; Soriano-Correa, Catalina

    2014-08-01

    The course of the Diels-Alder reactions of cyclopentadiene and maleic anhydride were studied. Two reaction paths were modelled: endo- and exo-selective paths. All structures within the transient region were characterized and analyzed by means of geometrical descriptors, physicochemical parameters and information-theoretical measures in order to observe the linkage between chemical behavior and the carriage of information. We have shown that the information-theoretical characterization of the chemical course of the reaction is in complete agreement with its phenomenological behavior in passing from reactants to products. In addition, we were able to detect the main differences between the two reaction mechanisms. This type of informational analysis serves to provide tools to help understand the chemical reactivity of the two simplest Diels-Alder reactions, which permits the establishment of a connection between the quantum changes that molecular systems exert along reaction coordinates and standard physicochemical phenomenology. In the present study, we have shown that every reaction stage has a family of subsequent structures that are characterized not solely by their phenomenological behavior but also by informational properties of their electronic density distribution (localizability, order, uniformity). Moreover, we were able to describe the main differences between endo-adduct and exo-adduct pathways. With the advent of new experimental techniques, it is in principle possible to observe the structural changes in the transient regions of chemical reactions. Indeed, through this work we have provided the theoretical concepts needed to unveil the concurrent processes associated with chemical reactions. PMID:25086767

  12. An interpenetrating HA/G/CS biomimic hydrogel via Diels-Alder click chemistry for cartilage tissue engineering.

    PubMed

    Yu, Feng; Cao, Xiaodong; Zeng, Lei; Zhang, Qing; Chen, Xiaofeng

    2013-08-14

    In order to mimic the natural cartilage extracellular matrix, a novel biological degradable interpenetrating network hydrogel was synthesized from the gelatin (G), hyaluronic acid (HA) and chondroitin sulfate (CS) by Diels-Alder "click" chemistry. HA was modified with furylamine and G was modified with furancarboxylic acid respectively. (1)H NMR spectra and elemental analysis showed that the substitution degrees of HA-furan and G-furan were 71.5% and 44.5%. Then the hydrogels were finally synthesized by cross-linking furan-modified HA and G derivatives with dimaleimide poly(ethylene glycol) (MAL-PEG-MAL). The mechanical and degradation properties of the hydrogels could be tuned simply through varying the molar ratio between furan and maleimide. Rheological, mechanical and degradation studies demonstrated that the Diels-Alder "click" chemistry is an efficient method for preparing high performance biological interpenetrating hydrogels. This biomimic hydrogel with improved mechanical properties could have great potential applications in cartilage tissue engineering. PMID:23769536

  13. Synthesis of the Reported Pyranonaphthoquinone Structure of the Indoleamine-2,3-dioxygenase Inhibitor Annulin B by Regioselective Diels-Alder Reaction.

    PubMed

    Inman, Martyn; Carvalho, Catarina; Lewis, William; Moody, Christopher J

    2016-09-01

    Annulin B, isolated from the marine hydroid isolated from Garveia annulata, is a potent inhibitor of the tryptophan catabolizing enzyme indoleamine-2,3-dioxygenase (IDO). A synthesis of the reported pyranonaphthoquinone structure is described, in which the key step is a regioselective Diels-Alder reaction between a pyranobenzoquinone dienophile and a silyl ketene acetal diene. PMID:27513176

  14. Integration of Computational and Preparative Techniques to Demonstrate Physical Organic Concepts in Synthetic Organic Chemistry: An Example Using Diels-Alder Reaction

    ERIC Educational Resources Information Center

    Palmer, David R. J.

    2004-01-01

    The Diels-Alder reaction is used as an example for showing the integration of computational and preparative techniques, which help in demonstrating the physical organic concepts in synthetic organic chemistry. These experiments show that the students should not accept the computational results without questioning them and in many Diels-Alder…

  15. Bicyclic Guanidine Catalyzed Asymmetric Tandem Isomerization Intramolecular-Diels-Alder Reaction: The First Catalytic Enantioselective Total Synthesis of (+)-alpha-Yohimbine.

    PubMed

    Feng, Wei; Jiang, Danfeng; Kee, Choon-Wee; Liu, Hongjun; Tan, Choon-Hong

    2016-02-01

    Hydroisoquinoline derivatives were prepared in moderate to good enantioselectivities via a bicyclic guanidine-catalyzed tandem isomerization intramolecular-Diels-Alder (IMDA) reaction of alkynes. With this synthetic method, the first enantioselective synthesis of (+)-alpha-yohimbine was completed in 9 steps from the IMDA products. PMID:25932622

  16. Diels-Alder Synthesis of endo-cis-N-phenylbicyclo[2.2.2]oct-5-en-2,3-dicarboximide

    ERIC Educational Resources Information Center

    Baar, Marsha R.; Wustholz, Kristin

    2005-01-01

    A study investigated the Diels-Alder synthesis of endo-cis-N-phenylbicyclo [2.2.2]oct-5-en-2,3-dicarboximide. The amount of time taken by a reaction between the 1,3-cyclohexadiene and N-phenylmaleimide at room temperature and also whether the desired cycloadduct would precipitate directly from the reaction mixture was examined.

  17. Fast Hetero-Diels-Alder Reactions Using 4-Phenyl-1,2,4-Triazoline-3,5-Dione (PTAD) as the Dienophile

    ERIC Educational Resources Information Center

    Celius, Tevye C.

    2010-01-01

    A hetero-Diels-Alder reaction that proceeds rapidly and only requires a simple filtration to purify the product is presented. The dienophile, 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD), is prepared by the heterogeneous oxidation of 4-phenylurazole by the bromenium ion, Br[superscript +], generated in situ by the oxidation of potassium bromide by…

  18. Illustrating the Utility of X-Ray Crystallography for Structure Elucidation through a Tandem Aldol Condensation/Diels-Alder Reaction Sequence

    ERIC Educational Resources Information Center

    Hoang, Giang T.; Kubo, Tomohiro; Young, Victor G., Jr.; Kautzky, Jacob A.; Wissinger, Jane E.

    2015-01-01

    Two introductory organic chemistry laboratory experiments are described based on the Diels-Alder reaction of 2,3,4,5-tetraphenylcyclopentadienone, which is synthesized prior to or in a one-pot reaction, with styrene. Students are presented with three possible products, the "endo" and "exo" diastereomers and the decarbonylated…

  19. The Synthesis of "N"-Benzyl-2-Azanorbornene via Aqueous Hetero Diels-Alder Reaction: An Undergraduate Project in Organic Synthesis and Structural Analysis

    ERIC Educational Resources Information Center

    Sauvage, Xavier; Delaude, Lionel

    2008-01-01

    The synthesis of "N"-benzyl-2-azanorbornene via aqueous hetero Diels-Alder reaction of cyclopentadiene and benzyliminium chloride formed in situ from benzylamine hydrochloride and formaldehyde is described. Characterization of the product was achieved by IR and NMR spectroscopies. The spectral data acquired are thoroughly discussed. Numerous…

  20. Diels-Alder Cycloadditions: A MORE Experiment in the Organic Laboratory Including a Diene Identification Exercise Involving NMR Spectroscopy and Molecular Modeling

    ERIC Educational Resources Information Center

    Shaw, Roosevelt; Severin, Ashika; Balfour, Miguel; Nettles, Columbus

    2005-01-01

    Two Diels-Alder reactions are described that are suitable for a MORE (microwave-induced organic reaction enhanced) experiment in the organic chemistry laboratory course. A second experiment in which the splitting patterns of the vinyl protons in the nuclear magnetic resonance (NMR) spectra of two MORE adducts are used in conjunction with molecular…

  1. Synthesis of a Self-Healing Polymer Based on Reversible Diels-Alder Reaction: An Advanced Undergraduate Laboratory at the Interface of Organic Chemistry and Materials Science

    ERIC Educational Resources Information Center

    Weizman, Haim; Nielsen, Christian; Weizman, Or S.; Nemat-Nasser, Sia

    2011-01-01

    This laboratory experiment exposes students to the chemistry of self-healing polymers based on a Diels-Alder reaction. Students accomplish a multistep synthesis of a monomer building block and then polymerize it to form a cross-linked polymer. The healing capability of the polymer is verified by differential scanning calorimetry (DSC) experiments.…

  2. N,N'-Dioxide/nickel(ii)-catalyzed asymmetric Diels-Alder reaction of cyclopentadiene with 2,3-dioxopyrrolidines and 2-alkenoyl pyridines.

    PubMed

    Lu, Yan; Zhou, Yuhang; Lin, Lili; Zheng, Haifeng; Fu, Kai; Liu, Xiaohua; Feng, Xiaoming

    2016-07-01

    A chiral N,N'-dioxide/Ni(OTf)2 complex-catalyzed asymmetric Diels-Alder reaction of cyclopentadiene with 2,3-dioxopyrrolidines and 2-alkenoyl pyridines has been achieved. The corresponding chiral bridged compounds were obtained in high yields with excellent dr and ee values (up to 97% yield, 95 : 5 dr and 97% ee). PMID:27284594

  3. A π-electronic covalent organic framework catalyst: π-walls as catalytic beds for Diels-Alder reactions under ambient conditions.

    PubMed

    Wu, Yang; Xu, Hong; Chen, Xiong; Gao, Jia; Jiang, Donglin

    2015-06-25

    We report a strategy for developing π-electronic covalent organic frameworks as heterogeneous catalysts that enable the use of columnar π-walls as catalytic beds to facilitate organic transformations in their one-dimensional open channels. The π-frameworks exhibit outstanding catalytic activity, promote Diels-Alder reactions under ambient conditions and are robust for cycle use. PMID:26000867

  4. Benthic macroinvertebrate richness along Sausal Creek, Oakland, California

    NASA Astrophysics Data System (ADS)

    Lara, D.; Ahumada, E.; Leon, Y.; Bracho, H.; Telles, C.

    2012-12-01

    Sausal Creek, 5.0 km long, is one of the principal watercourses in Oakland, California. The headwaters of Sausal Creek arise in the Oakland Hills and the creek flows southwestward through the city, discharging into the tidal canal that separates the island of Alameda from Oakland; the creek ultimately flows into San Francisco Bay. Due to the presence of rainbow trout, the stream health of Sausal Creek is a local conservation priority. In the present study, a survey of benthic macroinvertebrates in the creek was conducted and possible correlations between environmental variables and taxonomic richness were analyzed. Three stations along the creek were sampled using a 30.5cm 500 micron aquatic d-net, and temperature, pH and dissolved oxygen levels were measured in creek samples obtained at each station. Temperature, pH and dissolved oxygen levels remained constant along the creek. Taxonomic richness was highest at the upstream site of Palo Seco, located in an eastern section of the creek, and furthest downstream at Dimond Park, in the western portion of the creek. The Monterrey site, just west of Palo Seco was found to be significantly low in benthic macroinvertebrates. The Palo Seco and Monterrey sites are separated by Highway 13 and storm drain inputs may bring contaminants into the creek at this site. At the Monterrey site Sausal Creek follows the Hayward Fault, gas emissions or change in substrate may also affect the local population of benthic invertebrates. Further research will be conducted to determine what factors are contributing to this local anomaly.

  5. Surface-water quality in the Campbell Creek basin, Anchorage, Alaska

    USGS Publications Warehouse

    Brabets, T.P.; Wittenberg, L.A.

    1983-01-01

    Four streams in the Campbell Creek Basin were sampled during different flow conditions for an 18-month period. North Fork Campbell and South Fork Campbell Creeks drain areas virtually undisturbed by man 's activities. The other two streams, Little Campbell Creek and the main stem Campbell Creek, drain areas that have been urbanized. The water from South Fork Campbell and North Fork Campbell Creeks is of good quality and does not adversely affect the water quality of the main stem Campbell Creek. Little Campbell Creek, which has been affected by urbanization, impacts the water quality of Campbell Creek during lowland snowmelt periods when discharges from South Fork Campbell and North Fork Campbell Creeks are small. High concentrations of suspended sediment in Campbell Creek may be contributed by Little Campbell Creek. Fecal-coliform bacteria concentrations are highest at Little Campbell Creek and probably account for most of the high coliform concentrations at Campbell Creek. (USGS)

  6. Summer food habits and trophic overlap of roundtail chub and creek chub in Muddy Creek, Wyoming

    USGS Publications Warehouse

    Quist, M.C.; Bower, M.R.; Hubert, W.A.

    2006-01-01

    Native fishes of the Upper Colorado River Basin have experienced substantial declines in abundance and distribution, and are extirpated from most of Wyoming. Muddy Creek, in south-central Wyoming (Little Snake River watershed), contains sympatric populations of native roundtail chub (Gila robusta), bluehead sucker, (Catostomus discobolus), and flannelmouth sucker (C. tatipinnis), and represents an area of high conservation concern because it is the only area known to have sympatric populations of all 3 species in Wyoming. However, introduced creek chub (Semotilus atromaculatus) are abundant and might have a negative influence on native fishes. We assessed summer food habits of roundtail chub and creek chub to provide information on the ecology of each species and obtain insight on potential trophic overlap. Roundtail chub and creek chub seemed to be opportunistic generalists that consumed a diverse array of food items. Stomach contents of both species were dominated by plant material, aquatic and terrestrial insects, and Fishes, but also included gastropods and mussels. Stomach contents were similar between species, indicating high trophic, overlap. No length-related patterns in diet were observed for either species. These results suggest that creek chubs have the potential to adversely influence the roundtail chub population through competition for food and the native fish assemblage through predation.

  7. 77 FR 21722 - Gore Creek Restoration Project; Intent To Prepare an Environmental Impact Statement

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-11

    ... Forest Service Gore Creek Restoration Project; Intent To Prepare an Environmental Impact Statement AGENCY: Medicine Bow-Routt National Forests, Forest Service, USDA. Project: Gore Creek Restoration Project. ACTION... proposed Gore Creek Restoration Project (Gore Creek). The Gore Creek analysis area...

  8. Active channel for Fanno Creek, Oregon

    USGS Publications Warehouse

    Sobieszczyk, Steven

    2011-01-01

    Fanno Creek is a tributary to the Tualatin River and flows though parts of the southwest Portland metropolitan area. The stream is heavily influenced by urban runoff and shows characteristic flashy streamflow and poor water quality commonly associated with urban streams. This data set represents the active, wetted channel as derived from light detection and ranging (LiDAR) data and aerial photographic imagery. The wetted channel boundary is equivalent to the extent of water observed during a 2-yr high flow event.

  9. Channel stability of Turkey Creek, Nebraska

    USGS Publications Warehouse

    Rus, David L.; Soenksen, Philip J.

    1998-01-01

    Channelization on Turkey Creek and its receiving stream, the South Fork Big Nemaha River, has disturbed the equilibrium of Turkey Creek and has led to channel-stability problems, such as degradation and channel widening, which pose a threat to bridges and land adjacent to the stream. As part of a multiagency study, the U.S. Geological Survey assessed channel stability at two bridge sites on upper and middle portions of Turkey Creek by analyzing streambed-elevation data for gradation changes, comparing recent cross-section surveys and historic accounts, identifying bank-failure blocks, and analyzing tree-ring samples. These results were compared to gradation data and trend results for a U.S. Geological Survey streamflow-gaging station near the mouth of Turkey Creek from a previous study. Examination of data on streambed elevations reveals that degradation has occurred. The streambed elevation declined 0.5 m at the upper site from 1967-97. The streambed elevation declined by 3.2 m at the middle site from 1948-97 and exposed 2 m of the pilings of the Nebraska Highway 8 bridge. Channel widening could not be verified at the two sites from 1967-97, but a historic account indicates widening at the middle site to be two to three times that of the 1949 channel width. Small bank failures were evident at the upper site and a 4-m-wide bank failure occurred at the middle site in 1987 according to tree ring analyses. Examination of streambed-elevation data from a previous study at the lower site reveals a statistically significant aggrading trend from 1958-93. Further examination of these data suggests minor degradation occurred until 1975, followed by aggradation.

  10. 27 CFR 9.85 - Willow Creek.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... where the 1,000-foot contour line intersects Kirkham Creek (directly north of section 19, T.7 N./R.5E.), beginning in a southerly direction, the boundary line the 1,000-foot contour line to; (1) The point of intersection between the 1,000-foot contour line and the north section line of section 27, T.6N./R.5E.;...

  11. 27 CFR 9.85 - Willow Creek.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... where the 1,000-foot contour line intersects Kirkham Creek (directly north of section 19, T.7 N./R.5E.), beginning in a southerly direction, the boundary line the 1,000-foot contour line to; (1) The point of intersection between the 1,000-foot contour line and the north section line of section 27, T.6N./R.5E.;...

  12. 27 CFR 9.85 - Willow Creek.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... where the 1,000-foot contour line intersects Kirkham Creek (directly north of section 19, T.7 N./R.5E.), beginning in a southerly direction, the boundary line the 1,000-foot contour line to; (1) The point of intersection between the 1,000-foot contour line and the north section line of section 27, T.6N./R.5E.;...

  13. 27 CFR 9.85 - Willow Creek.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... where the 1,000-foot contour line intersects Kirkham Creek (directly north of section 19, T.7 N./R.5E.), beginning in a southerly direction, the boundary line the 1,000-foot contour line to; (1) The point of intersection between the 1,000-foot contour line and the north section line of section 27, T.6N./R.5E.;...

  14. 27 CFR 9.85 - Willow Creek.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... where the 1,000-foot contour line intersects Kirkham Creek (directly north of section 19, T.7 N./R.5E.), beginning in a southerly direction, the boundary line the 1,000-foot contour line to; (1) The point of intersection between the 1,000-foot contour line and the north section line of section 27, T.6N./R.5E.;...

  15. DRY CREEK WILDERNESS STUDY AREA, ARKANSAS.

    USGS Publications Warehouse

    Haley, Boyd R.; Stroud, Raymond B.

    1984-01-01

    The Dry Creek Wilderness Study Area covers an area of about 10 sq mi in parts of Logan, Scott, and Yell Counties, Arkansas. A mineral evaluation study of the area indicated that the area has a probable resource potential for natural gas and little promise for the occurrence of other mineral commodities. Less than 100,000 cu ft/day of natural gas is being produced from one well about 4 mi north of the area.

  16. Parachute Creek shale-oil program. [Brochure

    SciTech Connect

    Not Available

    1982-01-01

    Union Oil Company has a plan for commercial shale-oil production at the Parachute Creek area of Colorado. This brochure describes the property and the company's concept for room and pillar mining and upflow retorting. Environmental precautions will preserve and restore vegetation on disturbed land and will safeguard local streams and underground basinx. Union will assist local communities to provide housing and services. 17 figures. (DCK)

  17. 75 FR 27332 - AER NY-Gen, LLC; Eagle Creek Hydro Power, LLC; Eagle Creek Water Resources, LLC; Eagle Creek Land...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-14

    ... Energy Regulatory Commission AER NY-Gen, LLC; Eagle Creek Hydro Power, LLC; Eagle Creek Water Resources... Comments and Motions To Intervene May 7, 2010. On April 30, 2010, AER NY-Gen, LLC (transferor) and Eagle.... Joseph Klimaszewski, AER NY- Gen, LLC, 613 Plank Road, Forestburgh, New York, 12777; phone (845)...

  18. Steel Creek primary producers: Periphyton and seston, L-Lake/Steel Creek Biological Monitoring Program, January 1986--December 1991

    SciTech Connect

    Bowers, J.A.; Toole, M.A.; van Duyn, Y.

    1992-02-01

    The Savannah River Site (SRS) encompasses 300 sq mi of the Atlantic Coastal Plain in west-central South Carolina. Five major tributaries of the Savannah River -- Upper Three Runs Creek, Four Mile Creek, Pen Branch, Steel Creek, and Lower Three Runs Creek -- drain the site. In 1985, L Lake, a 400-hectare cooling reservoir, was built on the upper reaches of Steel Creek to receive effluent from the restart of L-Reactor and to protect the lower reaches from thermal impacts. The Steel Creek Biological Monitoring Program was designed to assess various components of the system and identify and changes due to the operation of L-Reactor or discharge from L Lake. An intensive ecological assessment program prior to the construction of the lake provided baseline data with which to compare data accumulated after the lake was filled and began discharging into the creek. The Department of Energy must demonstrate that the operation of L-Reactor will not significantly alter the established aquatic ecosystems. This report summarizes the results of six years` data from Steel Creek under the L-Lake/Steel Creek Monitoring Program. L Lake is discussed separately from Steel Creek in Volumes NAI-SR-138 through NAI-SR-143.

  19. Rock Creek Tower Painting Project : Environmental Assessment.

    SciTech Connect

    United States. Bonneville Power Administration.

    1988-10-01

    Bonneville Power Administration (BPA) built a 500-kV line across Rock Creek, a Class I trout stream about 20 miles east of Missoula, MT. Two 190-foot towers rise on either side of the Rock Creek valley, and the line between is suspended 600 feet over the valley floor. The crossing poses a hazard to passing airplanes and disrupts the natural landscape. The area where the line crosses Rock Creek is prized for its scenic beauty. In response to public demand that BPA protect the visual beauty of this area, BPA painted the towers gray to blend them best in with their natural surroundings. The issue now is to decide between either two gray towers or two orange-and-white towers. The underlying need is to resolve the conflict of pilot safety against scenic intrusion. The proposed action is to paint the gray tower aeronautical orange and white. Alternatives are to paint the orange-and-white tower back to its original gray; or leave the dilemma unresolved (the ''no-action'' alternative). 9 refs., 3 figs.

  20. Denverton Creek gas field, Solano County, California

    SciTech Connect

    Lindblom, R.G.; Jacobson, J.B.

    1988-02-01

    The Denverton Creek gas field is located in Solano County, California, 40 mi northeast of San Francisco on the west side of the Sacramento Valley. The field was discovered in 1966 by the Mobil Oil Corporation Trojan Powder 1 well from a sand of Paleocene age within the Martinez channel. During 1967 and 1968, new pool discoveries were made in other Paleocene sands. Commercial gas deliveries began in March 1967 and ceased in 1971, and the field was abandoned in 1973 with a cumulative production of 712 million ft/sup 3/ of gas from three wells. Increases in natural gas prices during the middle and late 1970s, coupled with sound geological concepts supported by improved seismic data, led to a number of discoveries in the valley. Included in this effort was reestablishment of production at Denverton Creek in 1977 by new drilling. Chevron USA, in joint ventures with Cities Service and Channel Exploration, has drilled nine wells in the field, which developed two new pool discoveries. In 1986, the field produced 5 bcf of gas from 11 wells. Gas entrapment in the Denverton Creek field is caused by a number of anomalies, including sand pinch-out, faulting, and truncations by unconformities and the Martinez channel. Although these types of entrapping mechanisms are found in other fields in the Sacramento Valley, the Denverton Creekfield is unique in that all are present in one producing area.

  1. Steel creek macroinvertebrates: L Lake/steel creek biological monitoring program January 1986--December 1987

    SciTech Connect

    O'Hop, J.R.; Lauritsen, D.; Magoulik, D.

    1988-04-01

    The macroinvertebrate community in Steel Creek was monitored at 13 sampling stations from January 1986 to December 1987 to assess the effects of L-Lake impoundment on the biological community downstream from the dam. The benthic macroinvertebrate communities were sampled monthly at 13 stations in Steel Creek using artificial substrates. Macroinvertebrates suspended in the water column were collected monthly at seven stations using drift nets. Emerging aquatic insects were sampled monthly at seven stations with floating emergence traps. Invertebrates on natural substrates (bottom sediments, snags, and macrophytes) were collected at seven stations in May and September in both 1986 and 1987. Macroinvertebrates were collected in February and August of 1986 and 1987 at 13 stations in Steel Creek using dip nets. 61 refs., 79 figs., 18 tabs.

  2. Bioassessment of Hollis Creek, Oktibbeha County, Mississippi

    USGS Publications Warehouse

    Winger, P.V.; Lasier, P.J.; Bogenrieder, K.J.

    2000-01-01

    Physical, chemical and biological components at five stations on Hollis Creek, Oktibbeha County, Mississippi were evaluated using Rapid Bioassessment Protocols (RBP) and the Sediment Quality Triad (SQT) on August 24-26, 1999, in order to assess potential biological impacts from the Starkville Waste Water Treatment Facility (WWTF) on downstream resources. Two stations were selected above the WWTF and three below. The WWTF discharges treated effluent into Hollis Creek, but during storm events raw sewage may be released. Hollis Creek is a tributary of the Noxubee River that traverses the northern portion of Noxubee National Wildlife Refuge, which is managed as bottomland hardwood forest land for the protection of fish and wildlife resources. Hollis Creek was channelized throughout most of its length, resulting in high, unstable banks, degraded stream channel and unstable substratum. The RBP scores for the habitat evaluations from each station indicated that Stations 1 and 2 had degraded habitat compared to the reference site, Station 5. Benthic macroinvertebrate and fish assemblages also indicated that the biological integrity at Stations 1 and 2 was less than that of the downstream stations. The SQT showed that Stations 1 and 2 were degraded and the most likely causes of the impairment were the elevated concentrations of polycylclic aromatic hydrocarbons and metals in the sediments; Hyalella azteca survival in pore water and growth in solid-phase sediment exposures were reduced at these upstream sites. The source of contaminants to the upper reaches appears to be storm-water runoff. The close concordance between the RBP and SQT in identifying site degradation provided a preponderance of evidence indicating that the upper reaches (Stations 1 and 2) of Hollis Creek were impacted. Biological conditions improved downstream of the WWTF, even though physical degradation steinming from channelization activities were still evident. The increased discharge and stabilized base

  3. Geologic map of the Skull Creek Quadrangle, Moffat County Colorado

    USGS Publications Warehouse

    Van Loenen, R. E.; Selner, Gary; Bryant, W.A.

    1999-01-01

    The Skull Creek quadrangle is in northwestern Colorado a few miles north of Rangely. The prominent structural feature of the Skull Creek quadrangle is the Skull Creek monocline. Pennsylvanian rocks are exposed along the axis of the monocline while hogbacks along its southern flank expose rocks that are from Permian to Upper Cretaceous in age. The Wolf Creek monocline and the Wolf Creek thrust fault, which dissects the monocline, are salient structural features in the northern part of the quadrangle. Little or no mineral potential exists within the quadrangle. A geologic map of the Lazy Y Point quadrangle, which is adjacent to the Skull Creek quadrangle on the west, is also available (Geologic Investigations Series I-2646). This companian map shows similar geologic features, including the western half of the Skull Creek monocline. The geology of this quadrangle was mapped because of its proximity to Dinosaur National Monument. It is adjacent to quadrangles previously mapped to display the geology of this very scenic and popular National Monument. The Skull Creek quadrangle includes parts of the Skull Creek Wilderness Study Area, which was assessed for its mineral resource potential.

  4. Northeast and northwest elevations. View to south Flint Creek ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Northeast and northwest elevations. View to south - Flint Creek Hydroelectric Project, Powerhouse, Approximately 3 miles southeast of Porters Corner on Powerhouse Road, Philipsburg, Granite County, MT

  5. Topographic view of McCord Creek Bridge and the Columbia River ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Topographic view of McCord Creek Bridge and the Columbia River Gorge - McCord Creek Bridge, Spanning McCord Creek at Milepost 38.62 on Old Columbia River Highway (Highway No. 30), Warrendale, Multnomah County, OR

  6. Northeastern Florida Bay estuarine creek data, water years 1996-2000

    USGS Publications Warehouse

    Hittle, Clinton D.; Zucker, Mark A.

    2004-01-01

    From October 1995 to September 2000 (water years 1996-2000), continuous 15-minute stage, water velocity, salinity, and water temperature data were collected at seven estuarine creeks that flow into northeastern Florida Bay. These creeks include West Highway Creek, Stillwater Creek, Trout Creek, Mud Creek, Taylor River, Upstream Taylor River, and McCormick Creek. Discharge was computed at 15-minute intervals using mean water velocity and the cross-sectional area of the channel. Fifteen-minute unit values are presented for comparison of the quantity, quality, timing, and distribution of flows through the creeks. Revised discharge estimation formulas are presented for three noninstrumented sites (East Highway Creek, Oregon Creek and Stillwater Creek) that utilize an improved West Highway discharge rating. Stillwater Creek and Upstream Taylor River were originally noninstrumented sites; both were fully instrumented in 1999. Discharge rating equations are presented for these sites and were developed using a simple linear regression.

  7. Diels-Alder attachment of a planar organic molecule to a dangling bond dimer on a hydrogenated semiconductor surface.

    PubMed

    Godlewski, Szymon; Kawai, Hiroyo; Engelund, Mads; Kolmer, Marek; Zuzak, Rafal; Garcia-Lekue, Aran; Novell-Leruth, Gerard; Echavarren, Antonio M; Sanchez-Portal, Daniel; Joachim, Christian; Saeys, Mark

    2016-06-22

    Construction of single-molecule electronic devices requires the controlled manipulation of organic molecules and their properties. This could be achieved by tuning the interaction between the molecule and individual atoms by local "on-surface" chemistry, i.e., the controlled formation of chemical bonds between the species. We demonstrate here the reversible attachment of a planar conjugated polyaromatic molecule to a pair of unpassivated dangling bonds on a hydrogenated Ge(001):H surface via a Diels-Alder [4+2] addition using the tip of a scanning tunneling microscope (STM). Due to the small stability difference between the covalently bonded and a nearly undistorted structure attached to the dangling bond dimer by long-range dispersive forces, we show that at cryogenic temperatures the molecule can be switched between both configurations. The reversibility of this covalent bond forming reaction may be applied in the construction of complex circuits containing organic molecules with tunable properties. PMID:27271337

  8. Pyrone Diels-Alder Routes to Indolines and Hydroindolines: Syntheses of Gracilamine, Mesembrine, and Δ(7) -Mesembrenone.

    PubMed

    Gan, Pei; Smith, Myles W; Braffman, Nathaniel R; Snyder, Scott A

    2016-03-01

    Although the Diels-Alder reaction has long been utilized for the preparation of numerous heterocycles, opportunities to extend its power remain. Herein, we detail a simple, modular, and robust approach that combines various amines regioselectively with 4,6-dichloropyrone to create substrates which, under appropriate conditions, can directly deliver varied indolines and hydroindolines through [4+2] cycloadditions with substitution patterns difficult to access otherwise. As an initial demonstration of the power of the strategy, several different natural products have been obtained either formally or by direct total synthesis, with efforts toward one of these-the complex amaryllidaceae alkaloid gracilamine-affording the shortest route to date in terms of linear step count. PMID:26865400

  9. Catalytic Effects of Oxide Surfaces on Diels-Alder Cycloaddition between Furan and Methyl Acrylate: A DFT Study

    NASA Astrophysics Data System (ADS)

    Salavati-Fard, Taha; Jenness, Glen; Caratzoulas, Stavros; Doren, Douglas

    Using density functional theory with periodic boundary conditions, we study the catalytic effects of oxide surfaces such as ZrO_2 and HfO_2 on Diels-Alder reaction between furan and methyl acrylate. The cycloadduct can be dehydrated later to produce methyl benzoic which is an important step toward benzoic acid production. The gas-phase and on-surface reaction mechanisms are studied in detail. The surface hydration effects on the reaction mechanism and energy profile are studied as well. Our calculations show that the oxide surfaces catalyze the reaction significantly through the interaction of metal sites with methyl acrylate. The calculations are interpreted by making use of electronic density of states and band structure of the catalyst.

  10. Factors Controlling the Reactivity and Selectivity of the Diels-Alder Reactions Involving 1,2-Azaborines.

    PubMed

    García-Rodeja, Yago; Fernández, Israel

    2016-08-01

    The factors controlling the reactivity and endo/exo selectivity of the Diels-Alder reactions involving 1,2-azaborines have been computationally explored within the density functional theory framework. It is found that the AlCl3-catalyzed [4 + 2]-cycloaddition reaction between these dienes and N-methylmaleimide proceeds concertedly and leads almost exclusively to the corresponding endo cycloadduct, which is in good agreement with previous experimental observations. In addition, the effect of the substituent directly attached to the boron atom of the 1,2-azaborine on the process is also analyzed in detail. To this end, the combination of the activation strain model of reactivity and the energy decomposition analysis methods has been applied to gain a quantitative understanding into the origins of the endo selectivity of the process as well as the influence of the boron and nitrogen substituent on the barrier heights of the transformations. PMID:27383907

  11. Full cell study of Diels Alder poly(phenylene) anion and cation exchange membranes in vanadium redox flow batteries

    DOE PAGESBeta

    Pezeshki, Alan M.; Fujimoto, Cy; Sun, Che -Nan; Mench, Matthew M.; Zawodzinski, Thomas A.; Tang, Z. J.

    2015-11-14

    In this paper, we report on the performance of Diels Alder poly(phenylene) membranes in vanadium redox flow batteries. The membranes were functionalized with quaternary ammonium groups to form an anion exchange membrane (QDAPP) and with sulfonic acid groups to form a cation exchange membrane (SDAPP). Both membrane classes showed similar conductivities in the battery environment, suggesting that the ion conduction mechanism in the material is not strongly affected by the moieties along the polymer backbone. The resistance to vanadium permeation in QDAPP was not improved relative to SDAPP, further suggesting that the polarity of the functional groups do not playmore » a significant role in the membrane materials tested. Both QDAPP and SDAPP outperformed Nafion membranes in cycling tests, with both achieving voltage efficiencies above 85% while maintaining 95% coulombic efficiency while at a current density of 200 mA/cm2.« less

  12. Full cell study of Diels Alder poly(phenylene) anion and cation exchange membranes in vanadium redox flow batteries

    SciTech Connect

    Pezeshki, Alan M.; Fujimoto, Cy; Sun, Che -Nan; Mench, Matthew M.; Zawodzinski, Thomas A.; Tang, Z. J.

    2015-11-14

    In this paper, we report on the performance of Diels Alder poly(phenylene) membranes in vanadium redox flow batteries. The membranes were functionalized with quaternary ammonium groups to form an anion exchange membrane (QDAPP) and with sulfonic acid groups to form a cation exchange membrane (SDAPP). Both membrane classes showed similar conductivities in the battery environment, suggesting that the ion conduction mechanism in the material is not strongly affected by the moieties along the polymer backbone. The resistance to vanadium permeation in QDAPP was not improved relative to SDAPP, further suggesting that the polarity of the functional groups do not play a significant role in the membrane materials tested. Both QDAPP and SDAPP outperformed Nafion membranes in cycling tests, with both achieving voltage efficiencies above 85% while maintaining 95% coulombic efficiency while at a current density of 200 mA/cm2.

  13. Elucidation of Diels-Alder Reaction Network of 2,5-Dimethylfuran and Ethylene on HY Zeolite Catalyst.

    PubMed

    Do, Phuong T M; McAtee, Jesse R; Watson, Donald A; Lobo, Raul F

    2013-01-01

    The reaction of 2,5-dimethylfuran and ethylene to produce p-xylene represents a potentially important route for the conversion of biomass to high-value organic chemicals. Current preparation methods suffer from low selectivity and produce a number of byproducts. Using modern separation and analytical techniques, the structure of many of the byproducts produced in this reaction when HY zeolite is employed as a catalyst has been identified. From these data, a detailed reaction network is proposed demonstrating that hydrolysis and electrophilic alkylation reactions compete with the desired Diels-Alder/dehydration sequence. This information will allow the rational identification of more selective catalysts and more selective reaction conditions. PMID:23316419

  14. Elucidation of Diels-Alder Reaction Network of 2,5-Dimethylfuran and Ethylene on HY Zeolite Catalyst

    PubMed Central

    Do, Phuong T.M.; McAtee, Jesse R.; Watson, Donald A.; Lobo, Raul F.

    2012-01-01

    The reaction of 2,5-dimethylfuran and ethylene to produce p-xylene represents a potentially important route for the conversion of biomass to high-value organic chemicals. Current preparation methods suffer from low selectivity and produce a number of byproducts. Using modern separation and analytical techniques, the structure of many of the byproducts produced in this reaction when HY zeolite is employed as a catalyst has been identified. From these data, a detailed reaction network is proposed demonstrating that hydrolysis and electrophilic alkylation reactions compete with the desired Diels-Alder/dehydration sequence. This information will allow the rational identification of more selective catalysts and more selective reaction conditions. PMID:23316419

  15. Irreversible endo-Selective Diels–Alder Reactions of Substituted Alkoxyfurans: A General Synthesis of endo-Cantharimides

    PubMed Central

    Foster, Robert W; Benhamou, Laure; Porter, Michael J; Bučar, Dejan-Krešimir; Hailes, Helen C; Tame, Christopher J; Sheppard, Tom D

    2015-01-01

    The [4+2] cycloaddition of 3-alkoxyfurans with N-substituted maleimides provides the first general route for preparing endo-cantharimides. Unlike the corresponding reaction with 3H furans, the reaction can tolerate a broad range of 2-substitued furans including alkyl, aromatic, and heteroaromatic groups. The cycloaddition products were converted into a range of cantharimide products with promising lead-like properties for medicinal chemistry programs. Furthermore, the electron-rich furans are shown to react with a variety of alternative dienophiles to generate 7-oxabicyclo[2.2.1]heptane derivatives under mild conditions. DFT calculations have been performed to rationalize the activation effect of the 3-alkoxy group on a furan Diels–Alder reaction. PMID:25756502

  16. Diels-Alder functionalized carbon nanotubes for bone tissue engineering: in vitro/in vivo biocompatibility and biodegradability

    NASA Astrophysics Data System (ADS)

    Mata, D.; Amaral, M.; Fernandes, A. J. S.; Colaço, B.; Gama, A.; Paiva, M. C.; Gomes, P. S.; Silva, R. F.; Fernandes, M. H.

    2015-05-01

    The risk-benefit balance for carbon nanotubes (CNTs) dictates their clinical fate. To take a step forward at this crossroad it is compulsory to modulate the CNT in vivo biocompatibility and biodegradability via e.g. chemical functionalization. CNT membranes were functionalised combining a Diels-Alder cycloaddition reaction to generate cyclohexene (-C6H10) followed by a mild oxidisation to yield carboxylic acid groups (-COOH). In vitro proliferation and osteogenic differentiation of human osteoblastic cells were maximized on functionalized CNT membranes (p,f-CNTs). The in vivo subcutaneously implanted materials showed a higher biological reactivity, thus inducing a slighter intense inflammatory response compared to non-functionalized CNT membranes (p-CNTs), but still showing a reduced cytotoxicity profile. Moreover, the in vivo biodegradation of CNTs was superior for p,f-CNT membranes, likely mediated by the oxidation-induced myeloperoxidase (MPO) in neutrophil and macrophage inflammatory milieus. This proves the biodegradability faculty of functionalized CNTs, which potentially avoids long-term tissue accumulation and triggering of acute toxicity. On the whole, the proposed Diels-Alder functionalization accounts for the improved CNT biological response in terms of the biocompatibility and biodegradability profiles. Therefore, CNTs can be considered for use in bone tissue engineering without notable toxicological threats.The risk-benefit balance for carbon nanotubes (CNTs) dictates their clinical fate. To take a step forward at this crossroad it is compulsory to modulate the CNT in vivo biocompatibility and biodegradability via e.g. chemical functionalization. CNT membranes were functionalised combining a Diels-Alder cycloaddition reaction to generate cyclohexene (-C6H10) followed by a mild oxidisation to yield carboxylic acid groups (-COOH). In vitro proliferation and osteogenic differentiation of human osteoblastic cells were maximized on functionalized CNT

  17. Enantio- and Diastereoselective Formal Hetero-Diels-Alder Reactions of Trifluoromethylated Enones Catalyzed by Chiral Primary Amines.

    PubMed

    Lin, Yong-Jun; Du, Li-Na; Kang, Tai-Ran; Liu, Quan-Zhong; Chen, Ze-Qin; He, Long

    2015-08-10

    Enantioselective formal hetero-Diels-Alder reactions of trifluoromethylated enones and 2-amino-1,3-butadienes generated in situ from aliphatic acyclic enones and chiral primary amines are reported. The corresponding tetrahydropyran-4-ones are formed in up to 94 % yield and with up to 94 % ee. The reaction was carried out through a stepwise mechanism, including initial aminocatalytic aldol condensation of 2-amino-1,3-butadiene to the trifluoromethylated carbonyl group followed by an intramolecular oxa-Michael addition. Both NMR investigation and theoretical calculations on the transition state indicate that the protonated tertiary amine could effectively activate the carbonyl group of the trifluoromethyl ketone to promote the addition process through hydrogen-bonding interaction of N-H⋅⋅⋅F and N-H⋅⋅⋅O simultaneously, and thus provide a chiral environment for the approach of amino-1,3-butadienes to the activated trifluoromethyl ketone, resulting in high enantioselectivity. PMID:26179273

  18. Enhancement of the Click Chemistry for the Inverse Diels Alder Technology by Functionalization of Amide-Based Monomers

    PubMed Central

    Pipkorn, Ruediger; Wiessler, Manfred; Waldeck, Waldemar; Lorenz, Peter; Muehlhausen, Ute; Fleischhacker, Heinz; Koch, Mario; Braun, Klaus

    2011-01-01

    In the near future personalized medicine with nucleic acids will play a key role in molecular diagnostics and therapy, which require new properties of the nucleic acids, like stability against enzymatic degradation. Here we demonstrate that the replacement of nucleobases with PNA by functional molecules harbouring either a dienophile or a diene reactivity is feasible and confers all new options for functionalization. These newly developed derivatives allow independent multi-ligations of multi-faceted components by use of the inverse Diels Alder technology. The high chemical stability and the ease of synthesis qualify these polyamide building blocks as favourites for intracellular delivery and targeting applications. This allows local drug concentrations sufficient for imaging and therapy and simultaneously a reduction of the application doses. It is important to point out that this technology is not restricted to ligation of medicament material; it is also a candidate to develop new and highly efficient active compounds for a “sustainable pharmacy”. PMID:21750642

  19. Diels-Alder Trapping of Photochemically Generated o-Quinodimethane Intermediates: An Alternative Route to Photocured Polymer Film Development

    NASA Technical Reports Server (NTRS)

    Tyson, Daniel S.; Ilhan, Faysal; Meador, Mary Ann B.; Smith, Dee Dee; Scheiman, Daniel A.; Meador, Michael A.

    2004-01-01

    Photolysis of o-methylphenyl ketones generates bis-o-quinodimethane intermediates that can be trapped in situ by dienophiles through Diels-Alder cycloadditions. This well-known photochemical process is applied to a series of six new photoreactive monomers containing bis-(o-methylphenyl ketone) functionalities combined with diacrylate and triacrylate ester monomers for the development of acrylic ester copolymer blends. Irradiation of cyclohexanone solutions of the bis-(o-methylphenyl ketone)s and acrylate esters produce thin polymer films. Solid state 13C NMR data indicated 47- 100% reaction of the bis-(o-methylphenyl ketone)s, depending on experimental conditions, to yield the desired products. DSC and TGA analyses were performed to determine the glass transition temperature, T,, and onset of decomposition, Td, of the resulting polymer films. A statistical Design of Experiments approach was used to obtain a systematic understanding of the effects of experimental variables on the extent of polymerization and the final polymer properties.

  20. Regioselective Synthesis of C-3-Functionalized Quinolines via Hetero-Diels-Alder Cycloaddition of Azadienes with Terminal Alkynes.

    PubMed

    Saunthwal, Rakesh K; Patel, Monika; Verma, Akhilesh K

    2016-08-01

    A highly efficient metal and protection-free approach for the regioselective synthesis of C-3-functionalized quinolines from azadienes (in situ generated from 2-aminobenzyl alcohol) and terminal alkynes through [4 + 2] cycloaddition has been developed. An unprecedented reaction of 2-aminobenzyl alcohol with 1,3- and 1,4-diethynylbenzene provided the C-3 tolylquinolines via [4 + 2] HDA and oxidative decarboxylation. The -NH2 group directed mechanistic approach was well supported by the control experiments and deuterium-labeling studies and by isolating the azadiene intermediate. The reactivity and selectivity of unprotected azadiene in metal-free base-assisted hetero-Diels-Alder reaction is exploited to quickly assemble an important class of C-3-functionalized quinolines, which are difficult to access. PMID:27380814

  1. Diels-Alder reactions for the rational design of benzo[b]thiophenes: DFT-based guidelines for synthetic chemists

    NASA Astrophysics Data System (ADS)

    Brasca, Romina; Kneeteman, María N.; Mancini, Pedro M. E.; Fabian, Walter M. F.

    2012-02-01

    In this work we studied the capability of several diene/dienophile pairs to undergo Diels-Alder (DA) reactions leading to benzo[b]thiophenes. A variety of synthetically and commercially available nitrothiophenes were chosen as dienophiles. Methyl 5-nitro-3-thiophenecarboxylate was selected as a potential strong electrophilic candidate based on some DFT-based properties and the substitution pattern of the expected product. The mechanistic details concerning the participation of this dienophile in polar DA reactions were investigated through a theoretical point of view. The results were compared with the experimental outcomes. This methodology should allow synthetic chemists to analyze DA reactions in detail in a stage prior to the synthetic job.

  2. Effects of surface inactivation, high temperature drying and preservative treatment on surface roughness and colour of alder and beech wood

    NASA Astrophysics Data System (ADS)

    Aydin, Ismail; Colakoglu, Gursel

    2005-10-01

    Although extensive research has been conducted in wood surface quality analysis, a unified approach to surface quality characterisation does not exist. Measurements of the variation in surface roughness and surface colour are used widely for the evaluation of wood surface quality. Colour is a basic visual feature for wood and wood-based products. Colour measurement is one of the quality control tests that should be carried out because the colour deviations are spotted easily by the consumers. On the other hand, a common problem faced by plywood manufacturers is panel delamination, for which a major cause is poor quality glue-bonds resulting from rough veneer. Rotary cut veneers with dimensions of 500 mm × 500 mm × 2 mm manufactured from alder ( Alnus glutinosa subsp. barbata) and beech ( Fagus orientalis Lipsky) logs were used as materials in this study. Veneer sheets were oven-dried in a veneer dryer at 110 °C (normal drying temperature) and 180 °C (high drying temperature) after peeling process. The surfaces of some veneers were then exposed at indoor laboratory conditions to obtain inactive wood surfaces for glue bonds, and some veneers were treated with borax, boric acid and ammonium acetate solutions. After these treatments, surface roughness and colour measurements were made on veneer surfaces. High temperature drying process caused a darkening on the surfaces of alder and beech veneers. Total colour change value (Δ E*) increased linear with increasing exposure time. Among the treatment solutions, ammonium acetate caused the biggest colour change while treatment with borax caused the lowest changes in Δ E* values. Considerable changes in surface roughness after preservative treatment did not occur on veneer surfaces. Generally, no clear changes were obtained or the values mean roughness profile ( Ra) decreased slightly in Ra values after the natural inactivation process.

  3. Tyrosine-Lipid Peroxide Adducts from Radical Termination: Para-Coupling and Intramolecular Diels-Alder Cyclization

    PubMed Central

    Shchepin, Roman; Möller, Matias N.; Kim, Hye-young H.; Hatch, Duane M.; Bartesaghi, Silvina; Kalyanaraman, Balaraman; Radi, Rafael

    2013-01-01

    Free radical co-oxidation of polyunsaturated lipids with tyrosine or phenolic analogs of tyrosine gave rise to lipid peroxide-tyrosine (phenol) adducts in both aqueous micellar and organic solutions. The novel adducts were isolated and characterized by 1D and 2D NMR as well as by mass spectrometry. The spectral data suggest that the polyunsaturated lipid peroxyl radicals give stable peroxide coupling products exclusively at the para position of the tyrosyl (phenoxy) radicals. These adducts have characteristic 13C chemical shifts at 185 ppm due to the cross-conjugated carbonyl of the phenol-derived cyclohexadienone. The primary peroxide adducts subsequently undergo intramolecular Diels-Alder (IMDA) cyclization, affording a number of diastereomeric tricyclic adducts that have characteristic carbonyl 13C chemical shifts at ~198 ppm. All NMR HMBC and HSQC correlations support the structure assignment of the primary and Diels-Alder adducts, as does MS collision induced dissociation. Kinetic rate constants and activation parameters for the IMDA reaction were determined and the primary adducts were reduced with cuprous ion giving a phenol-derived 4-hydroxycyclohexa-2,5-dienone. No products from adduction of peroxyls at the phenolic ortho position were found either in the primary or the cuprous reduction product mixtures. These studies provide a framework for understanding the nature of lipid-protein adducts formed by peroxyl-tyrosyl radical-radical termination processes. Coupling of lipid peroxyl radicals with tyrosyl radicals leads to cyclohexenone and cyclohexadienone adducts which are of interest in and of themselves since, as electrophiles, they are likely targets for protein nucleophiles. One consequence of lipid peroxyl reactions with tyrosyls may therefore be protein-protein crosslinks via interprotein Michael adducts. PMID:21090613

  4. Chemo-protective and regenerative effects of diarylheptanoids from the bark of black alder (Alnus glutinosa) in human normal keratinocytes.

    PubMed

    Dinić, Jelena; Ranđelović, Teodora; Stanković, Tijana; Dragoj, Miodrag; Isaković, Aleksandra; Novaković, Miroslav; Pešić, Milica

    2015-09-01

    Medicinal plants are recognized from ancient times as a source of diverse therapeutic agents and many of them are used as dietary supplements. Comprehensive approaches are needed that would identify bioactive components with evident activity against specific indications and provide a better link between science (ethno-botany, chemistry, biology and pharmacology) and market. Recently, the bark of black alder (Alnus glutinosa) appeared at market in the form of food supplement for treatment of different skin conditions. This study aimed to evaluate protective effects of two diarylheptanoids isolated from the bark of black alder: platyphylloside, 5(S)-1,7-di(4-hydroxyphenyl)-3-heptanone-5-O-β-D-glucopyranoside (1) and its newly discovered analog 5(S)-1,7-di(4-hydroxyphenyl)-5-O-β-D-[6-(E-p-coumaroylglucopyranosyl)]heptane-3-one (2) towards doxorubicin damaging activity. To that end, we employed HaCaT cells, non-cancerous human keratinocytes commonly used for skin regenerative studies. Diarylheptanoids significantly antagonized the effects of doxorubicin by lowering the sensitivity of HaCaT cells to this drug. Compound 2 prevented doxorubicin-induced cell death by activating autophagy. Both 1 and 2 protected HaCaT cells against doxorubicin-induced DNA damage. They significantly promoted migration and affected F-actin distribution. These results indicate that chemo-protective effects of diarylheptanoids may occur at multiple subcellular levels. Therefore, diarylheptanoids 1 and 2 could be considered as protective agents for non-cancerous dividing cells during chemotherapy. PMID:26162555

  5. Hydrologic analysis of Steel Creek and L Lake and the effects of flow reduction on Steel Creek habitat

    SciTech Connect

    del Carmen, B.R.; Paller, M.H.

    1993-12-31

    This report was prepared to support a proposal to eliminate the EIS mandated spring flow requirements in Steel Creek below L Lake. The base flow in Steel Creek below L Lake was estimated using historical data. The water balance of L Lake was studied to evaluate the effects of flow reduction on the Steel Creek hydrologic system. The base flow in Steel Creek below L Lake is estimated as 0.28 cms (10 cfs). A reduction in L Lake discharge to 0.28 cms will result in a fish community similar to the one that existed before the impoundment of L Lake.

  6. A Creek to Bay Biological Assessment in Oakland, California

    NASA Astrophysics Data System (ADS)

    Ahumada, E.; Ramirez, N.; Lopez, A.; Avila, M.; Ramirez, J.; Arroyo, D.; Bracho, H.; Casanova, A.; Pierson, E.

    2011-12-01

    In 2007, the Surface Water Ambient Monitoring Program (SWAMP) assessed the impact of trash on water quality in the Peralta Creek which is located in the Fruitvale district of Oakland, CA. This 2011 follow-up study will take further steps in evaluating the physical and biological impacts of pollution and human development on Peralta Creek and in the San Leandro Bay, where the Creek empties into the larger San Francisco Bay estuary. This study will utilize two forms of biological assessment in order to determine the level of water quality and ecosystem health of Peralta Creek and San Leandro Bay in Oakland, California. A Rapid Bioassesment Protocal (RBP) will be used as the method of biological assessment for Peralta Creek. RBP uses a biotic index of benthic macroinvertebrates to provide a measure of a water body's health. Larval trematodes found in two mud snails (Ilynassa obsoleta and Cerithidea californica) will be used to evaluate the health of the San Leandro Bay. Due to the complex life cycle of trematodes, the measure of trematode diversity and richness in host species serves as an indicator of estuarine health (Huspeni 2005). We have completed the assessment of one section of Peralta Creek, located at 2465 34th Avenue, Oakland, CA 94601. Abundance results indicate a moderately healthy creek because there were high levels of pollution tolerant benthic macroinvertebrates. The tolerant group of benthic macroinvertebrates includes such organisms as flatworms, leeches, and scuds. This is possibly due to this section of the creek being pumped up to the surface from culverts impacting the macroinvertebrate's life cycle. Another contributing factor to creek health is the amount of organic debris found in the creek, which inhibits the flow and oxygenation of the water, allowing for more pollution tolerant aquatic insects to persist. Further investigation is being conducted to fully assess the Peralta Creek watershed; from the preliminary results one can surmise that

  7. Hydrologic data collection at Crowders Creek and Steele Creek, York County, South Carolina, 1991-92

    USGS Publications Warehouse

    Gissendanner, John W.

    1994-01-01

    Rapid industrial and urban growth is anticipated in the vicinity of Crowders Creek near Clover, S.C., and Steele Creek near Fort Mill, S.C. These subbasins are in the Catawba River Basin in York County, S.C. To obtain baseline information on these basins prior to urbanization, gaging stations 02145642 (Crowders Creek near Clover, S.C.) and 021467801 (Steele Creek near Fort Mill, S.C.) were established to collect streamflow and water-quality data. Continuous stream-stage and streamflow data were collected during the periods of March 23, 1991 to September 30, 1992, and May 29, 1991 to September 30, 1992, for stations 02145642 and 021467801, respectively. Average streamflows for stations 02145642 and 021467801 for the study period were 80.5 cubic feet per second and 28.6 cubic feet per second, respectively. Water-quality data were collected on four separate occasions at each gage site; two samplings during low-flow events and two samplings during high-flow events. Fecal coliform concentrations exceeded minimum standards for freshwater with other physical and chemical constituents meeting South Carolina Department of Health and Environmental Control standards.

  8. WEST CLEAR CREEK ROADLESS AREA, ARIZONA.

    USGS Publications Warehouse

    Ulrich, George E.; Bielski, Alan M.

    1984-01-01

    Results of geologic, geochemical, and aeromagnetic studies and review of mineral records and prospect examination for the West Clear Creek Roadless Area, Arizona, indicate that there is little likelihood of the occurrence of mineral or energy resources. No concentrations of minerals were identified within the boundary of the area. A small manganese deposit occurs 1-3 mi east of the area but does not extend into the area. Slightly anomalous values for certain trace metals were found in samples taken within the area, but do not indicate the presence of metallic resources. Gypsum, basaltic cinders, and sandstone occur in the area.

  9. ROCK CREEK, IDAHO WATER QUALITY STATUS REPORT, 1970-1984

    EPA Science Inventory

    The study was designed to determine the characteristics and amounts of industrial and municipal wastes discharged to Rock Creek, Idaho (17040212) and subsequently into the Snake River and to evaluate the effects of these wastes on the biota and water quality of Rock Creek. Indus...

  10. 33 CFR 117.153 - Corte Madera Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Corte Madera Creek. 117.153 Section 117.153 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements California § 117.153 Corte Madera Creek. The draw...

  11. 33 CFR 117.153 - Corte Madera Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Corte Madera Creek. 117.153 Section 117.153 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements California § 117.153 Corte Madera Creek. The draw...

  12. 78 FR 76750 - Drawbridge Operation Regulation; Chambers Creek, Steilacoom, WA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-19

    ...The Coast Guard has issued a temporary deviation from the operating schedule that governs the Burlington Northern Santa Fe (BNSF) Chambers Creek Railway Bridge across Chambers Creek, mile 0.0, at Steilacoom, WA. The deviation is necessary to allow BNSF to perform maintenance and upgrade items to this vertical lift bridge in support of Positive Train Control requirements per the Rail Safety......

  13. "Bridge #6 Rock Creek: Castiron 48" pipe lines to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    "Bridge #6 - Rock Creek: Cast-iron 48" pipe lines to Gravity - 1859." Construction photo of Pennsylvania Avenue Bridge, 1859. Photograph courtesy Washington Aqueduct Division, U.S. Army Corps of Engineers - Pennsylvania Avenue Bridge, Spanning Rock Creek & Potomac Parkway, Washington, District of Columbia, DC

  14. DEEP CREEK, LATAH COUNTY, IDAHO - WATER QUALITY STATUS REPORT, 1988

    EPA Science Inventory

    Deep Creek, Idaho (17060108) had been identified as a first priority stream segment in the Nonpoint Source Pollution Abatement program. Current designated uses for Deep Creek are as a domestic and agricultural water supply, primary and secondary contact recreation, as well as co...

  15. Hydrologic data for Mountain Creek, Trinity River basin, Texas, 1976

    USGS Publications Warehouse

    Buckner, H.D.

    1978-01-01

    The total drainage area of Mountain Creek, Texas, is 304 sq mi. The stream-gaging stations on Mountain Creek near Cedar Hill and Walnut Creek near Mansfield provide hydrologic data to define runoff characteristics from small drainage basins. They also serve as index stations for inflow into the reservoir and provide operational data for the reservoir. In addition, the station Walnut Creek near Mansfield is equipped with a recording rain gage. The stage station near Duncanville provides data pertinent to operation of the gates in the Mountain Creek Lake Dam. The reservoir-content station at the dam provides records of reservoir state and contents. The stream-gaging station Mountain Creek at Grand Prairie provides records of outflow from Mountain Creek Lake and the basin. Basin outflow for the 1976 water year was 78,660 acre-feet which is only 1,140 acre-feet above the 16-year (1960-76) average of 77,520 acre-feet. Storage in Mountain Creek Lake showed a net gain of 760 acre-feet during the water year. Rainfall over the study area for the 1976 water year was about 32 inches, which is about 2 inches below the long-term mean rainfall (1960-75) for the area. (Woodard-USGS)

  16. RILEY CREEK, IDAHO WATER QUALITY STATUS REPORT, 1975-1976

    EPA Science Inventory

    The report presents a review of Riley Creek, Idaho (17040212) water quality data collected from September 1975 through September 1976. The creek meets all water quality standards except for total and fecal coliform bacteria. Sources of coliform bacteria include fish hatcheries,...

  17. Recovery of a PCB-Contaminated Creek Fish Community

    EPA Science Inventory

    Polychlorinated Biphenyls (PCBs) from the Sangamo-Weston Superfund Site near Clemson, South Carolina, USA, were released into the Twelvemile Creek until the early 1990s. PCB concentrations in fish in this creek have remained elevated: levels in six target fish species are still a...

  18. BILLINGSLEY CREEK, GOODING COUNTY, IDAHO. WATER QUALITY STATUS REPORT, 1984

    EPA Science Inventory

    Billingsley Creek in Gooding County, Idaho (17040212) has been identified as a stream where fish farm discharges and other land use practices are degrading water quality. The Idaho Department of Health and Welfare, Division of Environment sampled Billingsley Creek to assess in-s...

  19. 33 CFR 117.115 - Three Mile Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Three Mile Creek. 117.115 Section 117.115 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Alabama § 117.115 Three Mile Creek. (a) The draw...

  20. 78 FR 938 - Burton Creek Hydro Inc., Sollos Energy, LLC'

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-07

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Burton Creek Hydro Inc., Sollos Energy, LLC' Notice of Transfer of Exemption..., 1985,\\1\\ has been transferred to Sollos Energy, LLC. The project is located on Burton Creek in...

  1. 33 CFR 117.705 - Beaver Dam Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Beaver Dam Creek. 117.705 Section 117.705 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.705 Beaver Dam Creek. The draw of...

  2. 33 CFR 117.705 - Beaver Dam Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Beaver Dam Creek. 117.705 Section 117.705 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.705 Beaver Dam Creek. The draw of...

  3. 33 CFR 117.705 - Beaver Dam Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Beaver Dam Creek. 117.705 Section 117.705 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.705 Beaver Dam Creek. The draw of...

  4. 33 CFR 117.705 - Beaver Dam Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Beaver Dam Creek. 117.705 Section 117.705 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.705 Beaver Dam Creek. The draw of...

  5. 33 CFR 117.705 - Beaver Dam Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Beaver Dam Creek. 117.705 Section 117.705 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.705 Beaver Dam Creek. The draw of...

  6. 76 FR 37267 - Safety Zone, Pantego Creek; Belhaven, NC

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-27

    ...The Coast Guard is establishing a temporary safety zone on the Pantego Creek, Belhaven, NC. This action is necessary to protect the life and property of the maritime public from the hazards posed by fireworks displays. This zone is intended to restrict vessels from a portion of the Pantego Creek during the Belhaven Fourth of July...

  7. 2. Rear view of upper dam with Millstone Creek flowing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Rear view of upper dam with Millstone Creek flowing over overspill. Photograph taken from west bank of Millstone Creek. VIEW SOUTHEAST - Loleta Recreation Area, Upper Dam, 6 miles Southeast of interesection of State Route 24041 & State Route 66, Loleta, Elk County, PA

  8. Pataha Creek Model Watershed : 1998 Habitat Conservation Projects.

    SciTech Connect

    Bartels, Duane G.

    1999-12-01

    The projects outlined in detail on the attached project reports are a few of the many projects implemented in the Pataha Creek Model Watershed since it was selected as a model in 1993. 1998 was a year where a focused effort was made to work on the upland conservation practices to reduce the sedimentation into Pataha Creek.

  9. 2. LOOKING SOUTHEAST FROM THE WEST BANK OF HAW CREEK. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. LOOKING SOUTHEAST FROM THE WEST BANK OF HAW CREEK. A CLOSE-UP PHOTO OF THE NORTH SIDE OF THE BRIDGE, ITS PARAPETS AND THE UTILITY PIPES SUSPENDED FROM ITS OVERHANG. - Seventh Street Bridge, Spanning Haw Creek at Seventh Street, Columbus, Bartholomew County, IN

  10. 8. CLOSEUP OF THE GATES ON THE TOBY CREEK OUTLET ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. CLOSEUP OF THE GATES ON THE TOBY CREEK OUTLET AND THE OUTLET OF THE PUMP DISCHARGE CHANNEL, LOOKING NORTHEAST. - Wyoming Valley Flood Control System, Woodward Pumping Station, East of Toby Creek crossing by Erie-Lackawanna Railroad, Edwardsville, Luzerne County, PA

  11. 2. 'SANTA ANA RIVER AT CHINO CREEK, RIVERSIDE COUNTY.' This ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. 'SANTA ANA RIVER AT CHINO CREEK, RIVERSIDE COUNTY.' This is an oblique aerial view to the north, looking over the flooded fields between Chino Creek and the Santa Ana River, just upstream of the Prado Dam site. File number written on negative: R & H 80 024. - Prado Dam, Santa Ana River near junction of State Highways 71 & 91, Corona, Riverside County, CA

  12. 33. Site Plan: Custer Air Force Station, Battle Creek, Michigan, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    33. Site Plan: Custer Air Force Station, Battle Creek, Michigan, FD Radar Facilities-FPS-27, Electrical Plot Plan and Duet Details, USACOE, not date. - Fort Custer Military Reservation, P-67 Radar Station, .25 mile north of Dickman Road, east of Clark Road, Battle Creek, Calhoun County, MI

  13. Bridge 223, view looking east up Rock Creek Canyon at ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Bridge 22-3, view looking east up Rock Creek Canyon at Milepost 22.82. The line passes through tunnel 4 onto Bridge 22-3 and heads eastward up Rock Creek Canyon out onto the Camas Prairie - Camas Prairie Railroad, Second Subdivision, From Spalding in Nez Perce County, through Lewis County, to Grangeville in Idaho County, Spalding, Nez Perce County, ID

  14. WATER QUALITY STATUS REPORT, VINYARD CREEK, JEROME COUNTY, IDAHO. 1986

    EPA Science Inventory

    During 1986, a survey was done on Vinyard Creek (17040212) to assess water quality conditions and beneficial use impairment due to agricultural pollutants. During the 1986 irrigation season, Vinyard Creek transported an estimated 780 tons of sediment to the Snake River. Most of...

  15. DRY CREEK, IDAHO WATER QUALITY STATUS REPORT, 1976-1977

    EPA Science Inventory

    Water quality samples were collected monthly at one station in Water Year 1977 to determine the water quality status of Dry Creek in Twin Falls and Cassia Counties, Idaho (17040212). The stream was sampled near the mouth upstream from Murtaugh Lake. The section of Dry Creek abo...

  16. MIDDLE POTLATCH CREEK, LATAH COUNTY, IDAHO - PRELIMINARY INVESTIGATION REPORT, 1993

    EPA Science Inventory

    The 1992 Idaho Water Quality Status Report listed the Middle Potlatch Creek (17060306) as an Idaho Impaired Stream Segment Requiring Further Assessment and listed the creek as a water body not fully supporting at least one beneficial use. This preliminary resource assessment foc...

  17. 33 CFR 117.1001 - Cat Point Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Cat Point Creek. 117.1001 Section 117.1001 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Virginia § 117.1001 Cat Point Creek. The draw of...

  18. 33 CFR 117.1001 - Cat Point Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Cat Point Creek. 117.1001 Section 117.1001 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Virginia § 117.1001 Cat Point Creek. The draw of...

  19. 33 CFR 117.1001 - Cat Point Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Cat Point Creek. 117.1001 Section 117.1001 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Virginia § 117.1001 Cat Point Creek. The draw of...

  20. 33 CFR 117.1001 - Cat Point Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Cat Point Creek. 117.1001 Section 117.1001 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Virginia § 117.1001 Cat Point Creek. The draw of...

  1. 33 CFR 117.1001 - Cat Point Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Cat Point Creek. 117.1001 Section 117.1001 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Virginia § 117.1001 Cat Point Creek. The draw of...

  2. Major-ion, nutrient, and trace-element concentrations in the Steamboat Creek basin, Oregon, 1996

    USGS Publications Warehouse

    Rinella, Frank A.

    1998-01-01

    Bottom-sediment concentrations of antimony, arsenic, cadmium, copper, lead, mercury, zinc, and organic carbon were largest in City Creek. In City Creek and Horse Heaven Creek, concentrations for 11 constituents--antimony, arsenic, cadmium, copper, lead, manganese (Horse Heaven Creek only), mercury, selenium, silver, zinc, and organic carbon (City Creek only)--exceeded concentrations considered to be enriched in streams of the nearby Willamette River Basin, whereas in Steamboat Creek only two trace elements--antimony and nickel--exceeded Willamette River enriched concentrations. Bottom-sediment concentrations for six of these constituents in City Creek and Horse Heaven Creek--arsenic, cadmium, copper, lead, mercury, and zinc--also exceeded interim Canadian threshold effect level (TEL) concentrations established for the protection of aquatic life, whereas only four constituents between Singe Creek and Steamboat Creek--arsenic, chromium, copper (Singe Creek only), and nickel--exceeded the TEL concentrations.

  3. Unocal restarts Parachute Creek plant after turnaround

    SciTech Connect

    Not Available

    1986-12-01

    In late November, Unocal Corporation restarted its Parachute Creek shale oil project after a two-month turnaround, or overhaul operation. The plant is again operating at about 50% of its 10,000 barrel/day design capacity. This is the maximum rate which has been achieved for long periods of time. Unocal has been continuing to explore the possibility of adding a fluidized bed combustor to the retorting system. A decision on whether to proceed with building the FBC is expected to be made by July, 1987. The Colorado Mined Land Reclamation Board has allowed Unocal to make changes at Parachute Creek to better accommodate the handling of spent shale. These changes are described. Operating problems at the plant from start-up and modifications required are reviewed. Upgrading of the shale oil syncrude cannot be done at the Gary, Indiana refinery as planned. Current plans are to truck it to Utah, place it in a pipeline to Midland, Texas, then pipe it through Cushing, Oklahoma to the Unocal refinery in Lemont, Illinois.

  4. On the Diels-Alder approach to solely biomass-derived polyethylene terephthalate (PET): conversion of 2,5-dimethylfuran and acrolein into p-xylene.

    PubMed

    Shiramizu, Mika; Toste, F Dean

    2011-10-24

    Polyethylene terephthalate (PET) is a polymeric material with high global demand. Conventionally, PET is produced from fossil-fuel-based materials. Herein, we explored the feasibility of a sustainable method for PET production by using solely bio-renewable resources. Specifically, 2,5-dimethylfuran (derived from lignocellulosic biomass through 5-(hydroxymethyl)furfural) and acrolein (produced from glycerol, a side product of biodiesel production) were converted into the key intermediate p-xylene (a precursor of terephthalic acid). This synthesis consists of a sequential Diels-Alder reaction, oxidation, dehydration, and decarboxylation. In particular, the pivotal first step, the Diels-Alder reaction, was studied in detail to provide useful kinetic and thermodynamic data. Although it was found that this reaction requires low temperature to proceed efficiently, which presents a limitation on economic feasibility on an industrial scale, the concept was realized and bio-derived p-xylene was obtained in 34% overall yield over four steps. PMID:21922576

  5. Cyclopropanation of nitroso Diels–Alder cycloadducts and application to the synthesis of a 2’,3’-methano carbocyclic nucleoside

    PubMed Central

    Ji, Cheng; Miller, Marvin J.

    2010-01-01

    Treatment of nitroso Diels–Alder cycloadducts 1 with diazomethane in the presence of palladium acetate gives synthetically useful exo-6-oxa-7-azatricyclo[3.2.1.02,4]octane derivatives 7 in good to excellent yield. Using this methodology, a conformationally restricted 2’,3’-methano carbocyclic nucleoside was efficiently synthesized from nitroso cycloadduct 1a in 7 steps. PMID:20607121

  6. Adaptation of a Small-Molecule Hydrogen-Bond Donor Catalyst to an Enantioselective Hetero-Diels–Alder Reaction Hypothesized for Brevianamide Biosynthesis

    PubMed Central

    2015-01-01

    Chiral diamine-derived hydrogen-bond donors were evaluated for their ability to effect stereocontrol in an intramolecular hetero-Diels–Alder (HDA) reaction hypothesized in the biosynthesis of brevianamides A and B. Collectively, these results provide proof of principle that small-molecule hydrogen-bond catalysis, if even based on a hypothetical biosynthesis construct, holds significant potential within enantioselective natural product synthesis. PMID:25697748

  7. New and Concise Syntheses of the Bicyclic Oxamazin Core Using an Intramolecular Nitroso Diels-Alder Reaction and Ring-Closing Olefin Metathesis

    PubMed Central

    Watson, Kyle D.; Carosso, Serena

    2013-01-01

    Herein two new and concise synthetic approaches for making an unsaturated bicyclic oxamazin core are reported. The first involves the use of an intramolecular Diels-Alder reaction to form both of the fused rings in one step. The second approach incorporates ring-closing olefin metathesis in the final step to form the second fused ring of the core. The scope of the second approach was also expanded further to afford larger ringed bicyclic systems. PMID:23276301

  8. Sources of baseflow for the Minnehaha Creek Watershed, Minnesota, US

    NASA Astrophysics Data System (ADS)

    Nieber, J. L.; Moore, T. L.; Gulliver, J. S.; Magner, J. A.; Lahti, L. B.

    2013-12-01

    Minnehaha Creek is among the most valued surface water features in the Minneapolis, MN metro area, with a waterfall as it enters the Minnehaha Creek park. Flow in Minnehaha Creek is heavily dependent on discharge from the stream's origin, Lake Minnetonka, the outlet of which is closed during drought periods to maintain water elevations in the lake resulting in low- (or no-) flow conditions in the creek. Stormwater runoff entering directly to the creek from the creek's largely urbanized watershed exacerbates extremes in flow conditions. Given the cultural and ecological value of this stream system, there is great interest in enhancing the cultural and ecosystem services provided by Minnehaha Creek through improvements in streamflow regime by reducing flashiness and sustaining increased low-flows. Determining the potential for achieving improvements in flow requires first that the current sources of water contributing to low-flows in the creek be identified and quantified. Work on this source identification has involved a number of different approaches, including analyses of the streamflow record using a hydrologic system model framework, examination of the Quaternary and bedrock geology of the region, estimation of groundwater-surface water exchange rates within the channel using hyporheic zone temperature surveys and flux meter measurements, and analyses of the stable isotopes of oxygen and hydrogen in samples of stream water, groundwater, and rainfall. Analysis of baseflow recessions using the method of Brutsaert and Nieber (1977) indicates that only a small portion of the catchment, probably the riparian zone, contributes to baseflows. This result appears to be supported by the observation that the limestone/shale bedrock layer underlying the surficial aquifer has a non-zero permeability, and in a significant portion of the watershed the layer has been eroded away leaving the surficial aquifer ';bottomless' and highly susceptible to vertical (down) water loss

  9. Water Quality of Peralta and Courtland Creek Oakland, CA

    NASA Astrophysics Data System (ADS)

    Ahumada, A.; Zhen, K. L.; Ponce, X.; Johnson, A.; Varela, N.; Quintero, D.; Hernandez, G.; Oghogho, E.

    2014-12-01

    Authors: Allan Ahumada, Aminah Butler, Mellany Davis, Yarely Guzman, Micah Johnson, Xochitl Ponce, Kim Zhen Abstract: Beginning in the summer of 2012 and continuing to the present time our group has been assessing the water quality of Courtland Creek, which flows from Northeast to Southwest in East Oakland, California. During the summer of 2014 we began assessing the water quality at nearby Peralta Creek to compare the health of Courtland Creek with another one within the same watershed. In making our assessment we have analyzed samples collected from three different sites along both creeks for Nitrate, Phosphate, and Ammonia concentration levels. Additionally, we conducted benthic macroinvertebrate surveys at one site along each creek. Preliminary results indicate that nitrate levels in Courtland Creek waters are very high, which we believe is the result of human and animal waste entering into the creek. There were also unusually high levels of Phosphate and Ammonia detected in creek waters. Such high concentrations were noted in a past study and in an attempt to address this problem we initiated a native plant restoration project at one particular site located at the intersection of Courtland and Thompson avenues. This effort has resulted in a reduction in levels of Nitrate, Phosphate and Ammonia. The average levels of these compounds in waters collected near the restoration site were lower than those found in samples collected at other sites. However, they are still well above levels that are harmful to invertebrates and fish. Nitrate, Phosphate and Ammonia concentration levels in samples collected from Peralta Creek were significantly lower than those collected from Courtland Creek. For example, the maximum level of nitrate detected in Courtland Creek waters was 50 PPM while the maximum found in Peralta Creek waters was 15 PPM. We have concluded that the observed high levels of various compounds are the result of animal waste and human feces spilling directly

  10. Stratigraphy and depositional history of Coyote Creek-Miller Creek Trend, Lower Cretaceous Fall River formation, Powder River Basin, Wyoming

    SciTech Connect

    Ryer, T.A.; Gustason, E.R.

    1985-05-01

    The Coyote Creek-Miller Creek trend produces high-gravity, low-sulfur oil from a series of Fall River fields in an area generally characterized by west-southwestward monoclinal dip. The trend includes, from south to north, the Coyote Creek South, Coyote Creek, Donkey Creek, Kummerfeld, and Miller Creek fields. The Wood and West Moorcroft fields produce oil from very similar Fall River traps located several miles east and northeast, respectively, of Miller Creek. Only Donkey Creek includes structural closure; all of the other fields produce from purely stratigraphic traps. The reservoir sandstones are characterized by upward-fining sequences. These sequences locally replace and are generally easily distinguishable from two regionally correlative upward-coarsening sequences. Analyses of cores and nearby outcrops indicate that the upward-fining sequences accumulated on point bars of a meandering river; the upward-coarsening sequences were deposited on the fronts of northwestward-prograding deltas. Detailed mapping of the fluvial and delta-front facies demonstrates that the Coyote Creek-Miller Creek trend, together with the Wood and West Moorcroft fields, represents a meander-belt system that was contemporaneous with the younger of the two delta-front units. Each of the stratigraphic-type fields occurs at a convexity along the eastern edge of the irregularly shaped meander belt; each consists of numerous point bars. Clay plugs, which resulted from infilling of abandoned meander loops, were preferentially preserved along the margins of the meander belt, where they now serve as updip permeability barriers between the oil-bearing fluvial and water-wet delta-front sandstones.

  11. Geomorphic Response to Significant Sediment Loading Along Tahoma Creek on Mount Rainier, WA

    NASA Astrophysics Data System (ADS)

    Anderson, S.; Kennard, P.; Pitlick, J.

    2012-12-01

    Increased sediment loading in streams draining the flanks of Mt. Rainier has caused significant damage to National Park Service infrastructure and has prompted concern in downstream communities. The processes driving sedimentation and the controls on downstream response are explored in the 37 km2 Tahoma Creek basin, using repeat LiDAR surveys supplemented with additional topographic datasets. DEM differencing between 2003 and 2008 LiDAR datasets shows that over 2.2 million cubic meters of material was evacuated from the upper reaches of the basin, predominately in the form of debris flows. These debris flows were sourced in recently exposed lateral moraines, bulking through the broad collapse of unstable hillslopes. 40% of this material was deposited in the historic debris fan 4-6 km downstream of the terminus, while 55% completely exited the system at the downstream point of the surveys. Distinct zones of aggradation and incision of up to one meter are present along the lower channel and appear to be controlled by valley constrictions and inflections. However, the lower channel has shown remarkable long-term stability in the face of significant sediment loads. Alder ages suggest fluvial high stands in the late 70's and early 90's, immediately following periods of significant debris flow activity, yet the river quickly returned to pre-disturbance elevations. On longer time scales, the presence of old-growth forest on adjacent floodplain/terrace surfaces indicates broad stability on both vertical and horizontal planes. More than a passive indicator, these forested surfaces play a significant role in maintaining channel stability through increased overbank roughness and the formation of bank-armoring log jams. Sediment transport mechanics along this lower reach are explored using the TomSED sediment transport model, driven by data from an extensive sediment sampling and stream gaging effort. In its current state, the model is able to replicate the stability of the

  12. Hydrologic data from Roan Creek and Parachute Creek basins, northwestern Colorado

    USGS Publications Warehouse

    Adams, D.B.; Goddard, K.E.; Patt, R.O.; Galyean, K.C.

    1986-01-01

    Hydrologic data obtained from a comprehensive study of the Roan Creek and Parachute Creek basins are presented in this report. The purpose of this study was to inventory and appraise the predevelopment hydrologic conditions in these basins. The study was conducted from October 1975 through September 1981 and was one of several studies of oil-shale areas in the Western United States conducted by the U.S. Geological Survey. Data collected prior to October 1975 are presented, and references to other reports covering this area are given. Data collected include information from 58 wells, 286 springs, 14 streamflow-gaging stations and 24 miscellaneous surface water sites. Surface-water discharge, chemical-quality, and sediment data from streamflow-gaging stations in the basin are published in other reports listed in the references. (USGS)

  13. Comparative phylogenies and host specialization in the alder ectomycorrhizal fungi Alnicola, Alpova and Lactarius (Basidiomycota) in Europe

    PubMed Central

    2011-01-01

    Background Mycorrhizal fungi form intimate associations with their host plants that constitute their carbon resource and habitat. Alnus spp. (Betulaceae) are known to host an exceptional species-poor and specialized ectomycorrhizal (ECM) fungal community compared to other tree species, but the host-specificity pattern and its significance in terms of fungal diversification and speciation remain poorly documented. The degree of parallel speciation, host switching, and patterns of biogeography were explored in the historical associations between alders and three ECM taxa of Basidiomycetes: Alnicola (Agaricales), Alpova (Boletales), and Lactarius (Russulales). The aim was to develop an evolutionary framework on host specificity and diversification of Basidiomycetes in this highly specialized plant-fungus symbiosis. Results Sporocarps of Alnicola (220), Lactarius (61) and Alpova (29) were collected from stands of the four European alder species (A. alnobetula including the endemic subsp. suaveolens in Corsica, A. cordata, A. glutinosa, A. incana) in Western Europe (mainly in France and Austria), from 1995 to 2009. Specimens were morphologically identified to the species level. From these, 402 sequences of four DNA regions (ITS, rpb2, gpd, and the V9 domain of the mit-SSU rDNA) were successfully obtained and analyzed in addition with 89 sequences available in GenBank and UNITE databases. Phylogenetic analyses were conducted on all sequence data sets (individual and combined) using maximum likelihood reconstruction and Bayesian inference. Fungal phylogenies are compared and discussed in relation to the host, with a focus on species boundaries by associating taxonomic, systematic and molecular information. Conclusions Patterns of host specificity and phylogenies of Alnicola and Lactarius suggest coevolution as a basal factor of speciation in relation with the subgeneric diversification of Alnus, possibly due to the very selective pressure of the host. A second element of

  14. Stem Photosynthesis not Pressurized Ventilation is Responsible for Light-enhanced Oxygen Supply to Submerged Roots of Alder (Alnus glutinosa)

    PubMed Central

    ARMSTRONG, WILLIAM; ARMSTRONG, JEAN

    2005-01-01

    • Background and Aims Claims that submerged roots of alder and other wetland trees are aerated by pressurized gas flow generated in the stem by a light-induced thermo-osmosis have seemed inconsistent with root anatomy. Our aim was to seek a verification using physical root–stem models, stem segments with or without artificial roots, and rooted saplings. • Methods Radial O2 loss (ROL) from roots was monitored polarographically as the gas space system of the models, and stems were pressurized artificially. ROL and internal pressurization were also measured when stems were irradiated and the xylem stream was either CO2 enriched or not. Stem photosynthesis and respiration were measured polarographically. Stem and root anatomy were examined by light and fluorescence microscopy. • Key Results Pressurizing the models and stems to ≤10 kPa, values much higher than those reportedly generated by thermo-osmosis, created only a negligible density-induced increase in ROL, but ROL increased rapidly when ambient O2 concentrations were raised. Internal pressures rose by several kPa when shoots were exposed to high light flux and ROL increased substantially, but both were due to O2 accumulation from stem photosynthesis using internally sourced CO2. Increased stem pressures had little effect on O2 transport, which remained largely diffusive. Oxygen flux from stems in high light periods indicated a net C gain by stem photosynthesis. Chloroplasts were abundant in the secondary cortex and secondary phloem, and occurred throughout the secondary xylem rays and medulla of 3-year-old stems. Diurnal patterns of ROL, most marked when light reached submerged portions of the stem, were modified by minor variations in light flux and water level. Low root temperatures also helped improve root aeration. • Conclusions Pressurized gas flow to submerged roots does not occur to any significant degree in alder, but stem photosynthesis, using internally sourced CO2 from respiration and the

  15. +2 Valence Metal Concentrations in Lion Creek, Oakland, California

    NASA Astrophysics Data System (ADS)

    Vazquez, P.; Zedd, T.; Chagolla, R.; Dutton-Starbuck, M.; Negrete, A.; Jinham, M.; Lapota, M.

    2012-12-01

    Seven major creeks exist within the City of Oakland, California. These creeks all flow in the southwest direction from forested hills down through densely populated streets where they become susceptible to urban runoff. Lion Creek has been diverted to engineered channels and underground culverts and runs directly under our school (Roots International) before flowing into the San Leandro Bay. One branch of the creek begins near an abandoned sulfur mine. Previous studies have shown that extremely high levels of lead, arsenic and iron exist in this portion of the creek due to acid mine drainage. In this study +2 valence heavy metals concentration data was obtained from samples collected from a segment of the creek located approximately 2.8 miles downstream from the mine. Concentrations in samples collected at three different sites along this segment ranged between 50 ppb and 100 ppb. We hypothesize that these levels are related to the high concentration of +2 valence heavy metals at the mining site. To test this hypothesis, we have obtained samples from various locations along the roughly 3.75 miles of Lion Creek that are used to assess changes in heavy metals concentration levels from the mining site to the San Leandro Bay.

  16. Analytical results and sample locality maps of stream-sediment, heavy-mineral-concentrate, and rock samples from the Little Jacks Creek (ID-111-006), Big Jacks Creek (ID-111-007C), Duncan Creek (ID-111-0007B), and Upper Deep Creek (ID-111-044) Wilderness Study Areas, Owyhee County, Idaho

    SciTech Connect

    Erickson, M.S.; Gent, C.A.; Bradley, L.A.; King, H.D.

    1989-01-01

    A U.S. Geological Survey report detailing the analytical results and sample locality maps of stream-sediment, heavy-mineral-concentrate, and rock samples from the Little Jacks Creek, Big Jacks Creek, Duncan Creek, and Upper Deep Creek Wilderness Study Areas, Owyhee County, Idaho

  17. VALIDITY OF EFFLUENT AND AMBIENT TOXICITY TESTS FOR PREDICTING BIOLOGICAL IMPACT, SKELETON CREEK, ENID, OKLAHOMA

    EPA Science Inventory

    Skeleton Creek was studied in August, 1983 and was the fourth site study. A small creek, Boggy Creek receives discharges from both an oil refinery and a publicly owned treatment works (POTW) prior to its confluence with Skeleton Creek. A fertilizer processing plant discharge is l...

  18. 33 CFR 334.475 - Brickyard Creek and tributaries and the Broad River at Beaufort, SC.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... the MCAS to the intersection of Salt Creek with U.S. Highway 21, latitude 32.45047°, longitude 80.73153°, thence back down the southern creek edge of Salt and Albergottie Creeks, thence back to the... latitude 32.452376°, longitude 80.708263°. (5) That area contiguous to Salt Creek, situated within...

  19. 33 CFR 334.475 - Brickyard Creek and tributaries and the Broad River at Beaufort, SC.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... the MCAS to the intersection of Salt Creek with U.S. Highway 21, latitude 32.45047°, longitude 80.73153°, thence back down the southern creek edge of Salt and Albergottie Creeks, thence back to the... latitude 32.452376°, longitude 80.708263°. (5) That area contiguous to Salt Creek, situated within...

  20. 33 CFR 334.475 - Brickyard Creek and tributaries and the Broad River at Beaufort, SC.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... the MCAS to the intersection of Salt Creek with U.S. Highway 21, latitude 32.45047°, longitude 80.73153°, thence back down the southern creek edge of Salt and Albergottie Creeks, thence back to the... latitude 32.452376°, longitude 80.708263°. (5) That area contiguous to Salt Creek, situated within...