scholarly journals Interpreting and reporting 40Ar/39Ar geochronologic data

2020 ◽  
Author(s):  
Allen J. Schaen ◽  
Brian R. Jicha ◽  
Kip V. Hodges ◽  
Pieter Vermeesch ◽  
Mark E. Stelten ◽  
...  
Keyword(s):  
Noble Gas ◽  
Data Sets ◽  
Mass Spectrometers ◽  
Collateral Information ◽  
Wide Range ◽  
Bearing Materials ◽  
Broad Variety ◽  
Dating Method ◽  
Interpretive Strategies

The 40Ar/39Ar dating method is among the most versatile of geochronometers, having the potential to date a broad variety of K-bearing materials spanning from the time of Earth’s formation into the historical realm. Measurements using modern noble-gas mass spectrometers are now producing 40Ar/39Ar dates with analytical uncertainties of ∼0.1%, thereby providing precise time constraints for a wide range of geologic and extraterrestrial processes. Analyses of increasingly smaller subsamples have revealed age dispersion in many materials, including some minerals used as neutron fluence monitors. Accordingly, interpretive strategies are evolving to address observed dispersion in dates from a single sample. Moreover, inferring a geologically meaningful “age” from a measured “date” or set of dates is dependent on the geological problem being addressed and the salient assumptions associated with each set of data. We highlight requirements for collateral information that will better constrain the interpretation of 40Ar/39Ar data sets, including those associated with single-crystal fusion analyses, incremental heating experiments, and in situ analyses of microsampled domains. To ensure the utility and viability of published results, we emphasize previous recommendations for reporting 40Ar/39Ar data and the related essential metadata, with the amendment that data conform to evolving standards of being findable, accessible, interoperable, and reusable (FAIR) by both humans and computers. Our examples provide guidance for the presentation and interpretation of 40Ar/39Ar dates to maximize their interdisciplinary usage, reproducibility, and longevity.

scholarly journals In-situ microphysical characterization of low-level clouds in the Finnish sub-Arctic, extensive dataset

2021 ◽  
Author(s):  
Konstantinos Matthaios Doulgeris ◽  
Heikki Lihavainen ◽  
Anti-Pekka Hyvärinen ◽  
Veli-Matti Kerminen ◽  
David Brus
Keyword(s):  
Open Data ◽  
Arctic Region ◽  
Liquid Water Content ◽  
Dew Point ◽  
Data Repository ◽  
Effective Diameter ◽  
Data Sets ◽  
Low Level ◽  
Wide Range

Abstract. Continuous, semi-long-term, ground based in-situ cloud measurements were conducted during eight Pallas Cloud Experiments (PaCE) held in autumns between 2004 and 2019. Campaigns were carried out in the Finnish sub-Arctic region at the Sammaltunturi station (67°58′24′′ N, 24°06′58′′ E; 560 m MSL), the part of Pallas Atmosphere – Ecosystem Supersite and Global Atmosphere Watch (GAW) program. Two cloud spectrometer ground setups and a weather station were installed on the roof of the station to measure in-situ cloud properties and several meteorological variables. Thus, the obtained data sets include the size distribution of cloud droplets as a measured cloud parameter along with the temperature, dew point temperature, humidity, pressure, wind speed and direction, (global solar) sun radiation and visibility at the station. Additionally, the number concentration, effective diameter, median volume diameter and liquid water content from each instrument were derived. The presented data sets provide a great insight into microphysics of low-level clouds in sub-Arctic conditions over a wide range of temperatures (includes cloud cases with temperature from -25.8 to 8.8 °C). The data are available from the FMI open data repository for each campaign and each cloud spectrometer ground setup individually: https://doi.org/10.23728/FMI-B2SHARE.988739D21B824C709084E88ED6C6D54B (Doulgeris et al., 2021).

Preliminary results from interdisciplinary fault characterization in the Bedretto Underground Laboratory

2020 ◽  
Author(s):  
Alexis Shakas ◽  
Hannes Krietsch ◽  
Marian Hertrich ◽  
Nima Gholizadeh ◽  
Katrin Plenkers ◽  
...  
Keyword(s):  
Rock Mass ◽  
Fracture Zone ◽  
Geothermal Energy ◽  
Swiss Alps ◽  
Underground Laboratory ◽  
Data Sets ◽  
Remote Imaging ◽  
Wide Range

<p>Engineered Geothermal Systems (EGS) are gaining increasing popularity as a source of renewable energy without significant CO2 emissions. Fractured crystalline rock masses offer a promising environment for exploitation of geothermal energy. In such a setting, fractures and faults are the main conduits for fluid flow and heat transport. In-situ fracture permeabilities are usually too low at depths where rock mass temperatures are sufficiently high for geothermal energy production. Therefore, a suitable heat exchanger needs to be engineered by hydraulic stimulations. A proper in-situ characterization of the fracture geometry and hydro-mechanical properties is of primary importance for the design of the stimulation operations. This is often the most challenging task, since the majority of the fractures in the reservoir are usually inaccessible for direct characterization.</p><p> </p><p>The Bedretto Underground Laboratory for Geosciences (BULG) provides a novel and unique environment to study EGS-related processes, such as seismo-hydro-mechanical fault zone response during hydraulic stimulation and subsequent fluid circulation experiments. The laboratory is hosted in an access tunnel from the Bedretto Valley in the Southern Swiss Alps to a railway tunnel from the Matterhorn-Gotthard-Bahn. The overburden of more than 1000 m above the BULG provides conditions that are approaching those of realistic EGS systems. For the rock mass characterization, three boreholes were drilled perpendicular to tunnel axis with lengths ranging from 190 m to 300 m.</p><p> </p><p>We present first data sets from a variety of methodologies, ranging from hydrological tests to geophysical borehole- and remote-imaging. The complementary nature of these data sets allows us to construct a preliminary three dimensional geological model. Notably, the individual measurements yielded information over a multitude of scales, ranging from millimeter-scale core-log information to decameter scale low-frequency Ground Penetrating Radar measurements. Such a wide range of scales is critical for the characterization of EGS reservoirs. The most prominent feature found is a large-scale fracture zone that extends across the entire investigation volume. This fracture zone will be the target for upcoming stimulation experiments.</p>

The New Generation of Resonant Laser Ionization Mass Spectrometers: Becoming Competitive for Selective Atomic Ultra-Trace Determination?

2002 ◽  
Vol 8 (4) ◽  
pp. 273-285 ◽  
Author(s):  
Klaus D.A. Wendt
Keyword(s):  
Noble Gas ◽  
Ionization Mass ◽  
Trace Determination ◽  
Laser Ionization ◽  
Mass Spectrometers ◽  
Analytical Technique ◽  
Wide Range ◽  
Resonant Laser ◽  
Ultra Trace ◽  
Resonant Laser Ionization

A critical assessment of the present status of resonant laser ionization mass spectrometry (RIMS) as a specialized analytical technique for the field of atomic ultra-trace determination is attempted and a comparison with established mass spectrometric methods is made. Within the last years RIMS on atomic species has rapidly developed towards becoming a versatile experimental technique, in particular addressing those applications that require high selectivity in respect of isobaric or isotopic interferences. This progress is mainly based on the advent of easy-to-handle tunable solid-state laser systems for both pulsed and continuous operation, which are used in combination with modern compact mass spectrometers. The general basics, analytical potential and the wide range of applicability of these modern RIMS instruments are outlined and investigations on stable and radioactive ultra-trace isotopes are discussed as illustrative examples. These examples concern a variety of analytical applications in alkali, alkaline earth or noble gas elements as well as in lanthanides, actinides and technetium, covering fields of fundamental as well as applied research in environmental protection, geology and geochronology, biomedical and life sciences.

The HVEM-tandem user facility at Argonne National Laboratory

1988 ◽  
Vol 46 ◽  
pp. 806-807
Author(s):  
C. W. Allen ◽  
E. A. Ryan ◽  
S. T. Ockers
Keyword(s):  
Radiation Effects ◽  
Ion Irradiation ◽  
Noble Gas ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Western Hemisphere ◽  
Accelerator Facility ◽  
Wide Range ◽  
In Situ Experiments

Established in 1981, the High Voltage Electron Microscope-Tandem Ion Accelerator Facility (HVEM-Tandem) is a user-oriented resource for materials research. It is located at Argonne National Laboratory about 20 miles south of O'Hare International Airport near Chicago. The Facility consists of a modified Kratos/AEI HVEM with accelerating voltages ranging continuously from 0.1-1.2 MeV, interfaced to a 2 MV tandem and a 0.65 MV ion implanter-type accelerator. This combination of instruments offers capability, unique in the western hemisphere, for a wide range of in Situ experiments involving ion irradiation and ion implantation with simultaneous microscopy. During 1987 approximately 75% of microscope time was devoted to this type of experiment (Fig. 1) including studies of solid state phase transformations, such as amorphization, radiation damage and defect structures and the implantation of noble gas and metal ions.In situ experiments of various types account for nearly 90% of usage of the HVEM. In addition to the radiation effects studies, this includes experiments performed in the microscope involving deformation, annealing and environmental effects.

In-situ electrical-resistivity measurements in the high-voltage electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 68-69
Author(s):  
W. E. King
Keyword(s):  
Electrical Resistivity ◽  
Electron Microscope ◽  
High Voltage ◽  
Resistivity Measurements ◽  
Voltage Electron ◽  
High Voltage Electron Microscope ◽  
High Voltage Electron ◽  
Wide Range ◽  
Helium Gas

A side-entry type, helium-temperature specimen stage that has the capability of in-situ electrical-resistivity measurements has been designed and developed for use in the AEI-EM7 1200-kV electron microscope at Argonne National Laboratory. The electrical-resistivity measurements complement the high-voltage electron microscope (HVEM) to yield a unique opportunity to investigate defect production in metals by electron irradiation over a wide range of defect concentrations.A flow cryostat that uses helium gas as a coolant is employed to attain and maintain any specified temperature between 10 and 300 K. The helium gas coolant eliminates the vibrations that arise from boiling liquid helium and the temperature instabilities due to alternating heat-transfer mechanisms in the two-phase temperature regime (4.215 K). Figure 1 shows a schematic view of the liquid/gaseous helium transfer system. A liquid-gas mixture can be used for fast cooldown. The cold tip of the transfer tube is inserted coincident with the tilt axis of the specimen stage, and the end of the coolant flow tube is positioned without contact within the heat exchanger of the copper specimen block (Fig. 2).

Site specific agricultural soil management with the use of new technologies

2013 ◽  
Vol 16 (1) ◽  
pp. 59-67
Keyword(s):  
New Technologies ◽  
Digital Interface ◽  
Appropriate Treatment ◽  
Wide Range ◽  
Soil Variation ◽  
Soil Information ◽  
Remote Sensing Techniques ◽  
Agricultural Areas

<p>The Soil Science Institute of Thessaloniki produces new digitized Soil Maps that provide a useful electronic database for the spatial representation of the soil variation within a region, based on in situ soil sampling, laboratory analyses, GIS techniques and plant nutrition mathematical models, coupled with the local land cadastre. The novelty of these studies is that local agronomists have immediate access to a wide range of soil information by clicking on a field parcel shown in this digital interface and, therefore, can suggest an appropriate treatment (e.g. liming, manure incorporation, desalination, application of proper type and quantity of fertilizer) depending on the field conditions and cultivated crops. A specific case study is presented in the current work with regards to the construction of the digitized Soil Map of the regional unit of Kastoria. The potential of this map can easily be realized by the fact that the mapping of the physicochemical properties of the soils in this region provided delineation zones for differential fertilization management. An experiment was also conducted using remote sensing techniques for the enhancement of the fertilization advisory software database, which is a component of the digitized map, and the optimization of nitrogen management in agricultural areas.</p>

Development and Deployment of In-Situ Mass Spectrometers

2002 ◽  
Author(s):  
R. T. Short ◽  
Gottfried P. Kibelka ◽  
David P. Fries ◽  
Robert H. Byrne
Keyword(s):  
Mass Spectrometers

Development and Deployment of In-Situ Mass Spectrometers

2003 ◽  
Author(s):  
R. T. Short ◽  
David P. Fries ◽  
Robert H. Byrne
Keyword(s):  
Mass Spectrometers

Indium Bromide-catalyzed Unprecedented Hydrogenolysis: A Novel One-Pot Synthesis of Per-O-Acetylated β-carboxymethyl O and S-glycosides

2020 ◽  
Vol 24 (8) ◽  
pp. 900-908
Author(s):  
Ram Naresh Yadav ◽  
Amrendra K Singh ◽  
Bimal Banik
Keyword(s):  
Asymmetric Synthesis ◽  
Chiral Auxiliary ◽  
Bioactive Molecules ◽  
One Pot ◽  
Enantiomerically Pure ◽  
Stereoselective Glycosylation ◽  
One Pot Synthesis ◽  
Wide Range

Numerous O (oxa)- and S (thia)-glycosyl esters and their analogous glycosyl acids have been accomplished through stereoselective glycosylation of various peracetylated bromo sugar with benzyl glycolate using InBr3 as a glycosyl promotor followed by in situ hydrogenolysis of resulting glycosyl ester. A tandem glycosylating and hydrogenolytic activity of InBr3 has been successfully investigated in a one-pot procedure. The resulting synthetically valuable and virtually unexplored class of β-CMGL (glycosyl acids) could serve as an excellent potential chiral auxiliary in the asymmetric synthesis of a wide range of enantiomerically pure medicinally prevalent β-lactams and other bioactive molecules of diverse medicinal interest.

Interpretation In Qualitative Research: What, Why, How

2020 ◽  
pp. 955-982
Author(s):  
Allen Trent ◽  
Jeasik Cho
Keyword(s):  
Qualitative Research ◽  
Qualitative Inquiry ◽  
The Self ◽  
Validity Evidence ◽  
Wide Range ◽  
Interpretive Strategies

This chapter addresses a wide range of concepts related to interpretation in qualitative research, examines the meaning and importance of interpretation in qualitative inquiry, and explores the ways methodology, data, and the self/researcher as instrument interact and impact interpretive processes. Additionally, the chapter presents a series of strategies for qualitative researchers engaged in the process of interpretation and closes by presenting a framework for qualitative researchers designed to inform their interpretations. The framework includes attention to the key qualitative research concepts transparency, reflexivity, analysis, validity, evidence, and literature. Four questions frame the chapter: What is interpretation, and why are interpretive strategies important in qualitative research? How do methodology, data, and the researcher/self impact interpretation in qualitative research? How do qualitative researchers engage in the process of interpretation? And, in what ways can a framework for interpretation strategies support qualitative researchers across multiple methodologies and paradigms?

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