Bubble formation and growth - Study of the boundary conditions at a liquid-vapor interface through irreversible thermodynamics Quarterly progress report, Mar. - May 1966

Nonequilibrium effect on vapor bubble growth determined in study of boundary conditions at liquid-vapor interfac

Editorial for special issue “Geochemistry and mineralogy of hydrothermal metallic mineral deposits”

The Special Issue of Minerals on Geochemistry and Mineralogy of Hydrothermal Metallic Mineral Deposits presents the results of diverse geochemical and mineralogical research from across the globe. It is aimed to demonstrate that geochemical and mineralogical variation, both within and among hydrothermal ore deposits can be applied to genetic models, to exploration and drilling programs, and more. The eight contributions reflect a wide range of deposits, as well as different types of geochemical and mineralogical research applied to them. While most of these studies are focused on gaining a better understanding of deposit genesis, the results have a far greater application, as highlighted below

Bubble formation and growth - Study of the boundary conditions at a liquid-vapor interface through irreversible thermodynamics Quarterly progress report, Jun. - Aug. 1966

Steady state mercury evaporation experiment to measure transport coefficient in liquid-vapor interface boundary condition stud

Copper isotope constraints on the genesis of the Keweenaw Peninsula Native Copper District, Michigan, USA

The Keweenaw Peninsula native copper district of Michigan, USA is the largest concentration of native copper in the world. The copper isotopic composition of native copper was measured from stratabound and vein deposits, hosted by multiple rift-filling basalt-dominated stratigraphic horizons over 110 km of strike length. The δ65Cu of the native copper has an overall mean of +0.28‰ and a range of −0.32‰ to +0.80‰ (excluding one anomalous value). The data appear to be normally distributed and unimodal with no substantial differences between the native copper isotopic composition from the wide spread of deposits studied here. This suggests a common regional and relatively uniform process of derivation and precipitation of the copper in these deposits. Several published studies indicate that the ore-forming hydrothermal fluids carried copper as Cu1+, which is reduced to Cu0 during the precipitation of native copper. The δ65Cu of copper in the ore-forming fluids is thereby constrained to +0.80‰ or higher in order to yield the measured native copper values by reductive precipitation. The currently accepted hypothesis for the genesis of native copper relies on the leaching of copper from the rift-filling basalt-dominated stratigraphic section at a depth below the deposits during burial metamorphism. Oxidative dissolution of copper from magmatic source rocks with magmatic δ65Cu of 0‰ ± 0.3‰ is needed to obtain the copper isotopic composition of the metamorphogenic ore-forming hydrothermal fluids. In order to accommodate oxidative dissolution of copper from the rift-filling basalt source rocks, the copper needs to have been sited in native copper. Magmatic native copper in basalt is likely stable when the magma is low in sulfur. Low sulfur is predicted by the lack of sulfide minerals in the ore deposits and in the rift-filling basalt-dominated section, which are source rocks, the same rocks through which the ore fluids moved upwards, and the host rocks for the native copper ores. When combined with geologic evidence and inferences, the copper isotopic composition of native copper helps to further constrain the genetic model for this unique mining district

Sources of Hydrothermal Fluids Inferred from Oxygen and Carbon Isotope Composition of Calcite, Keweenaw Peninsula Native Copper District, Michigan, USA

The Mesoproterozoic North American Midcontinent Rift hosts the world’s largest accu-mulation of native copper in Michigan’s Keweenaw Peninsula. During a regional metamorpho-genic‐hydrothermal event, native copper was deposited along with spatially zoned main‐stage minerals in a thermal high. This was followed by deposition of late‐stage minerals including minor copper sulfide. Inferences from the oxygen and carbon isotopic composition of main‐stage hydrothermal fluids, as calculated from 296 new and compiled isotopic measurements on calcite, are consistent with existing models that low‐sulfur saline native copper ore‐forming fluids were domi-nantly derived by burial metamorphic processes from the very low sulfur basalt‐dominated rift fill at depth below the native copper deposits. Co‐variation of oxygen and carbon isotopic compositions are consistent with mixing of metamorphic‐derived fluids with two additional isotopically different fluids. One of these is proposed to be evolved seawater that provided an outside source of salinity. This fluid mixed at depth and participated in the formation of a well‐mixed hybrid metamorphic-dominated ore‐forming fluid. Secondary Ion Mass Spectrometry in‐situ isotopic analyses of calcite demonstrate a high degree of variability within samples that is attributed to variable degrees of shallow mixing of the hybrid ore‐forming fluid with sulfur‐poor, reduced evolved meteoric water in the zone of precipitation. The oxygen and carbon isotopic compositions of 100 new and compiled measurements on late‐stage calcite are mostly isotopically different than the main‐stage hydrothermal fluids. The late‐stage hydrothermal fluids are interpreted as various proportions of mixing of evolved meteoric water, main‐stage hybrid ore‐forming fluid, and shallow, evolved seawater in the relatively shallow zone of precipitation

A fast and reliable method for monitoring genomic instability in the model organism Caenorhabditis elegans

The identification of genotoxic agents and their potential for genotoxic alterations in an organism is crucial for risk assessment and approval procedures of the chemical and pharmaceutical industry. Classically, testing strategies for DNA or chromosomal damage focus on in vitro and in vivo (mainly rodent) investigations. In cell culture systems, the alkaline unwinding (AU) assay is one of the well-established methods for detecting the percentage of double-stranded DNA (dsDNA). By establishing a reliable lysis protocol, and further optimization of the AU assay for the model organism Caenorhabditis elegans (C. elegans), we provided a new tool for genotoxicity testing in the niche between in vitro and rodent experiments. The method is intended to complement existing testing strategies by a multicellular organism, which allows higher predictability of genotoxic potential compared to in vitro cell line or bacterial investigations, before utilizing in vivo (rodent) investigations. This also allows working within the 3R concept (reduction, refinement, and replacement of animal experiments), by reducing and possibly replacing animal testing. Validation with known genotoxic agents (bleomycin (BLM) and tert-butyl hydroperoxide (tBOOH)) proved the method to be meaningful, reproducible, and feasible for high-throughput genotoxicity testing, and especially preliminary screening

Emission rates of CO2 from plume measurements.

Most of the CO2 that emanated from Mount St. Helens became part of the gas plume as it moved away from the volcano. An airborne technique was developed for continuous sampling and infrared analysis for CO2 in the plume. The CO2-emission rates were determined by measuring the area, the horizontal velocity, and the CO2 concentration anomaly in vertical cross sections of the plume The emission rate varied from 2100 t/day to about 22 000 t/day.-from Autho