Evolution of Bioreactor Technologies for High-Concentration Contaminant Mixes in Groundwater     

John Horst  Jon Forbort  Mark Klemmer  Jen Kao  Robert J. Stuetzle  Rick Wenzel 《Ground Water Monitoring & Remediation》2019,39(3):12-22

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Bioremediation of 1,4-Dioxane: Successful Demonstration of In Situ and Ex Situ Approaches     

John F. Horst  Caitlin H. Bell  Andrew Lorenz  Monica Heintz  Yu Miao  Jackie Saling  David Favero  Shaily Mahendra 《Ground Water Monitoring & Remediation》2019,39(4):15-24

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On Frequency Response Corrections for Eddy Covariance Flux Measurements   总被引：6，自引：5，他引：1  

T. W. Horst 《Boundary-Layer Meteorology》2000,94(3):517-520

Several potentially significant errors are noted in published frequency-response corrections for eddy-covariance flux measurements.  相似文献   

Crystallographic and magnetic preferred orientation of hematite in banded iron ores     

Heinrich Siemes  Helmut Schaeben  Carlos A. Rosire  Horst Quade 《Journal of Structural Geology》2000,22(11-12)

The crystallographic preferred orientation of hematite in banded iron ores and the orientation of both the measured and the calculated principal susceptibility axes are strongly related. The maximum susceptibility is aligned with the lineation and the pole of the foliation coincides with the minimum susceptibility, although there are often distinct differences between the measured and calculated values of the susceptibilities. A wide variety of configurations of c-axis pole figures modeled by varying the parameters of the Bingham distribution and Bingham–Mardia-distribution reveal that quite different c-axis patterns of hematite ores may have the same anisotropy of the magnetic susceptibility (AMS) parameters. Large deviations between calculated and experimental AMS-data should initiate further investigations to resolve a probably unnoticed heterogeneity of the fabric. The present investigations show that the structural analysis of the preferred orientation of hematite ores by means of the rather inexpensive and fast magnetic method must be accompanied by the more expensive but unambiguous determination of preferred orientation by x-ray and neutron diffraction experiments in order to accomplish a complete and sound interpretation.  相似文献   

Calibration facility for airborne imaging spectrometers     

Peter Gege  Jochen Fries  Peter Haschberger  Paul Schtz  Horst Schwarzer  Peter Strobl  Birgit Suhr  Gerd Ulbrich  Willem Jan Vreeling 《ISPRS Journal of Photogrammetry and Remote Sensing》2009,64(4):387-397

A new facility designed to perform calibration measurements of airborne imaging spectrometers was established at the German Aerospace Center (DLR) in Oberpfaffenhofen. This Calibration Home Base (CHB) is optimized to characterize radiometrically, spectrally, and geometrically the APEX (Airborne Prism Experiment) imaging spectrometer, which is currently being developed under the authority of the European Space Agency (ESA). It however can be used for other optical sensors as well. Computer control of major laboratory equipment allows automation of time consuming measurements. In APEX configuration (wavelength range: 380 to 2500 nm, instantaneous field of view: 0.48 mrad, field of view: ±14) spectral measurements can be performed to a wavelength uncertainty of ±0.15 nm, geometric measurements at increments of 0.0017 mrad across track and 0.0076 mrad along track, and radiometric measurements to an uncertainty of ±3% relative to national standard. The CHB can be adapted to similar sensors (including those with thermal infrared detectors) by exchanging the monochromator’s lamp, the gratings and the filters, and by adjusting the distance between the sensor and folding mirror.  相似文献   

Transitioning Per- and Polyfluoroalkyl Substance Containing Fire Fighting Foams to New Alternatives: Evolving Methods and Best Practices to Protect the Environment     

John Horst  Joseph Quinnan  Jeffrey McDonough  Johnsie Lang  Peter Storch  Jeffrey Burdick  Corey Theriault 《Ground Water Monitoring & Remediation》2021,41(2):19-26

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Mass Flux Strategies 20 Years On—Getting the Sand Out of the Gears     

John Horst  Matthew Schnobrich  Craig Divine  Patrick Curry  Shawn Sager  Allan Horneman 《Ground Water Monitoring & Remediation》2021,41(4):13-21

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The origin of salinity and sulphate contamination of groundwater in the Colima State, Mexico, constrained by stable isotopes     

Axel Horst  Jürgen Mahlknecht  Miguel Angel López-Zavala  Bernhard Mayer 《Environmental Earth Sciences》2011,64(7):1931-1941

Chemical compositions and stable isotope ratios of water and sulphate were used to characterise sources and processes responsible for elevated concentrations of sulphate and other constituents in groundwater from aquifers at Colima State along Mexico’s Pacific Coast. The δ¹⁸O and δ²H values of the groundwater were similar to those of precipitation indicating a meteoric origin, and recharge processes are relatively uniform in large parts of the study area with only slight local evaporation effects. δ³⁴S_sulphate and δ¹⁸O_sulphate analyses indicated that high sulphate concentrations of up to 1,480 mg/l are mainly due to dissolution of evaporites and volcanic exhalations. Chloride is largely related to sources other than seawater. The Marabasco sub basin is affected by anthropogenic contamination through manganese and iron ore mining activities. The obtained knowledge regarding sources and areas of contamination will be essential for the development and design of a water quality monitoring program in the study area.  相似文献   

Reply to Comment by C. Gaucher et al. on "Chemostratigraphic constraints on early Ediacaran carbonate ramp dynamics,Río de la Plata craton,Uruguay" by Aubet et al. Gondwana Research (2012), Volume 22, Issues 3-4, November 2012, Pages 1073-1090     

Natalie R. Aubet  Ernesto Pecoits  Andrey Bekker  Murray K. Gingras  Horst Zwingmann  Gerardo Veroslavsky  Héctor de Santa Ana  Kurt O. Konhauser 《Gondwana Research》2013,23(3):1186-1188

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An experimental study of the Fe oxidation states in garnet and clinopyroxene as a function of temperature in the system CaO–FeO–Fe2O3–MgO–Al2O3–SiO2: implications for garnet–clinopyroxene geothermometry     

Horst Purwin  Stefan Lauterbach  Gerhard P. Brey  Alan B. Woodland  Hans-Joachim Kleebe 《Contributions to Mineralogy and Petrology》2013,165(4):623-639

Samples with eclogitic composition in the system CaO–FeO–Fe₂O₃–MgO–Al₂O₃–SiO₂ were produced from various kinds of starting materials held in graphite-lined Pt capsules at a pressure of 2.5–3.0 GPa and temperatures of 800–1,300 °C using a piston-cylinder or Belt apparatus. Garnets and clinopyroxenes were characterized by analytical transmission electron microscopy and electron probe micro-analysis (EPMA). Fe³⁺/ΣFe ratios determined by electron energy-loss spectroscopy (EELS) decrease in clinopyroxene from 22.2 ± 3.4 % at 800 °C to 13.3 ± 5.4 % at 1,300 °C, while in garnet, they vary between 10.8 ± 1.5 and 15.4 ± 4.7 %, respectively. Temperature estimates according to Krogh (Contrib Mineral Petrol 99:44–48, 1988) reproduce the experimental temperature to ±60 °C without systematic deviations if total iron is used in the calculation. If only the Fe²⁺ content is used, which was obtained by combining EPMA and EELS results, the experimental temperature is underestimated by 33 °C on average at 800–1,200 °C and overestimated by 77 °C on average at 1,300 °C. These systematic deviations can be explained by the temperature-dependent ratio of Fe²⁺/ΣFe in garnet divided by that in clinopyroxene. Since the difference between the calculated and experimental temperature is relatively small, a Fe²⁺-based recalibration of the thermometer appears not to be necessary for the investigated system in the range of pressure, temperature and composition covered by the experiments of this study.  相似文献