Concentrations of chemical constituents of precipitation are frequently expressed in terms of the precipitation-weighted mean, which has several desirable properties. Unfortunately, the weighted mean has no analytical analog of the standard error of the arithmetic mean for use in characterizing its statistical uncertainty. Several approximate expressions have been used previously in the literat...

Near-equilibrium calcite dissolution in seawater contributes significantly to the regulation of atmospheric [Formula: see text] on 1,000-y timescales. Despite many studies on far-from-equilibrium dissolution, little is known about the detailed mechanisms responsible for calcite dissolution in seawater. In this paper, we dissolve 13C-labeled calcites in natural seawater. We show that the time-ev...

First posted September 16, 2022 For additional information, contact: Director, Fort Collins Science CenterU.S. Geological Survey2150 Centre Ave., Bldg. CFort Collins, CO 80526-8118 The Loch Vale Watershed Research and Monitoring Program collects long-term datasets of ecological biogeochemical parameters in Rocky Mountain National Park to support both (1) management this protected area (2) resea...

Highly aqueously dispersible (soluble) TiO2 nanoparticles are usually synthesized by a solution-based sol-gel (solvolysis/condensation) process, and no direct precipitation of titania has been reported. This paper proposes a new approach to synthesize stable TiO2 nanoparticles by a non-solvolytic method - direct liquid phase precipitation at room temperature. Ligand-capped TiO2 nanoparticles ar...

In this paper, the chemical Functionalization of Carboxylate multi-walled carbon nanotubes by methyl (triphenyl phosphoranylidene) acetate have been investigated. Phosphorus Ylides are important compound in organic chemistry. At first, methyl (triphenyl phosphoranylidene) acetate, synthesized from salt metod in two steps: the formation of the phosphonium salt and the deprotonation of the latter...

Tubular growth by chemical precipitation at the interface between two fluids, a jet and its surroundings, underlies the development of such important structures as chimneys at hydrothermal vents. This growth is associated with strong thermal and/or solute gradients localized at those interfaces, and these gradients, in turn, often produce radial compositional stratification of the resulting tub...

OBJECTIVES Immunoglobulin paraproteins can interfere with multiple chemistry assays. We want to investigate the mechanisms of immunoglobulin interference. DESIGN AND METHODS Serum samples containing paraproteins from the index patient and eight additional patients were used to investigate the interference with the creatinine and total protein assays on the Beckman Coulter AU5400/2700 analyzer...

Chironomids, diatoms and microcrustaceans that inhabit aquatic ecosystems of the Northern Neotropics are abundant and diverse. Some species are highly sensitive to changes in water chemical composition and trophic state. This study was undertaken as a first step in developing transfer functions to infer past environmental conditions in the Northern lowland Neotropics. Bioindicator species abund...

[1] A simple model of the CaCO3 saturation state of the ocean is presented. It can be solved analytically and is intended to identify the fundamental controls on ocean carbonate ion concentration. It should also attract researchers unfamiliar with complex biogeochemical models. Despite its limitations, the modelcalculated CaCO3 saturation state of today’s ocean agrees well with observations. In...

In January and February 2009, a series of water samples were collected from streams on Byers Peninsula. These samples were analysed for major elements and dO to determine the role of lithology and landscape position on stream geochemistry, and to understand better the hydrology (i.e. residence time of water) of these systems. Precipitation chemistry is enriched in Na, as are the streams located...