An improved extraction chromatographic purification of tungsten from a silicate matrix for high precision isotopic measurements using MC-ICPMS

2018 ◽  
Vol 33 (4) ◽  
pp. 569-577 ◽  
Author(s):  
Qing-Feng Mei ◽  
Jin-Hui Yang ◽  
Yue-Heng Yang
Keyword(s):  
High Precision ◽  
Chemical Method ◽  
Silicate Matrix ◽  
Chromatographic Purification ◽  
Isotopic Compositions ◽  
Isotopic Measurements ◽  
Better Than

An improved chemical method is developed to accurately measure the W isotopic compositions of silicate samples with a precision of better than ±0.05ε on ε182W.

Laser-assisted hatching of embryos is better than the chemical method for enhancing the pregnancy rate in women with advanced age

2002 ◽  
Vol 78 (1) ◽  
pp. 179-182 ◽  
Author(s):  
Yao-Yuan Hsieh ◽  
Chun-Chia Huang ◽  
Tzu-Chun Cheng ◽  
Chi-Chen Chang ◽  
Horng-Der Tsai ◽  
...  
Keyword(s):  
Pregnancy Rate ◽  
Chemical Method ◽  
Advanced Age ◽  
Assisted Hatching ◽  
Better Than

High-precision Ru isotopic measurements by multi-collector ICP-MS

The Analyst ◽  
2002 ◽  
Vol 127 (6) ◽  
pp. 775-780 ◽  
Author(s):  
Harry Becker ◽  
Claude Dalpe ◽  
Richard J. Walker
Keyword(s):  
High Precision ◽  
Icp Ms ◽  
Isotopic Measurements

scholarly journals High-precision 41K/39K measurements by MC-ICP-MS indicate terrestrial variability of δ41K

2018 ◽  
Vol 33 (2) ◽  
pp. 175-186 ◽  
Author(s):  
Leah E. Morgan ◽  
Danielle P. Santiago Ramos ◽  
Brett Davidheiser-Kroll ◽  
John Faithfull ◽  
Nicholas S. Lloyd ◽  
...  
Keyword(s):  
High Resolution ◽  
High Precision ◽  
Cold Plasma ◽  
Isotopic Compositions ◽  
Icp Ms

Potassium isotopic compositions measured by MC-ICP-MS in cold-plasma, high-resolution mode indicate terrestrial variability in 41K/39K ratios.

scholarly journals HIPPI-2: A versatile high-precision polarimeter

2020 ◽  
Vol 37 ◽  
Author(s):  
Jeremy Bailey ◽  
Daniel V. Cotton ◽  
Lucyna Kedziora-Chudczer ◽  
Ain De Horta ◽  
Darren Maybour
Keyword(s):  
High Precision ◽  
New South ◽  
New South Wales ◽  
South Wales ◽  
The University ◽  
Better Than

Abstract We describe the High-Precision Polarimetric Instrument-2 (HIPPI-2) a highly versatile stellar polarimeter developed at the University of New South Wales. Two copies of HIPPI-2 have been built and used on the 60-cm telescope at Western Sydney University’s (WSU) Penrith Observatory, the 8.1-m Gemini North Telescope at Mauna Kea and extensively on the 3.9-m Anglo-Australian Telescope (AAT). The precision of polarimetry, measured from repeat observations of bright stars in the SDSS g′band, is better than 3.5 ppm (parts per million) on the 3.9-m AAT and better than 11 ppm on the 60-cm WSU telescope. The precision is better at redder wavelengths and poorer in the blue. On the Gemini North 8-m telescope, the performance is limited by a very large and strongly wavelength-dependent TP that reached 1000’s of ppm at blue wavelengths and is much larger than we have seen on any other telescope.

An optimized protocol for high precision measurement of Hg isotopic compositions in samples with low concentrations of Hg using MC-ICP-MS

2018 ◽  
Vol 33 (11) ◽  
pp. 1932-1940 ◽  
Author(s):  
Hongyan Geng ◽  
Runsheng Yin ◽  
Xiangdong Li
Keyword(s):  
High Precision ◽  
Precision Measurement ◽  
Direct Determination ◽  
Gas Flows ◽  
High Precision Measurement ◽  
Isotopic Compositions ◽  
Low Concentrations ◽  
Optimized Protocol ◽  
Icp Ms

Optimized gas flows achieved the direct determination of Hg isotopic compositions of 0.1 ng mL−1 solutions.

scholarly journals Multiplicity of Galactic Cepheids from long-baseline interferometry

2019 ◽  
Vol 622 ◽  
pp. A164 ◽  
Author(s):  
A. Gallenne ◽  
P. Kervella ◽  
S. Borgniet ◽  
A. Mérand ◽  
G. Pietrzyński ◽  
...  
Keyword(s):  
High Precision ◽  
Radial Velocities ◽  
Single Line ◽  
Radial Pulsation ◽  
Mass Measurements ◽  
Long Baseline ◽  
Car T ◽  
Term Objective ◽  
Better Than

Aims. We aim at detecting and characterizing the main-sequence companions of a sample of known and suspected Galactic binary Cepheids. The long-term objective is to accurately and independently measure the Cepheid masses and distances. Methods. We used the multi-telescope interferometric combiners CHARA/MIRC and VLTI/PIONIER to detect and measure the astrometric positions of the high-contrast companions orbiting 16 bright Galactic Cepheids. We made use of the CANDID algorithm to search for the companions and set detection limits from interferometric observations. We also present new high-precision radial velocity measurements which were used to fit radial pulsation and orbital velocities. Results. We report the detection of the companions orbiting the Cepheids U Aql, BP Cir, and S Mus, possible detections for FF Aql, Y Car, BG Cru, X Sgr, V350 Sgr, and V636 Sco, while no component is detected around U Car, YZ Car, T Mon, R Mus, S Nor, W Sgr, and AH Vel. For U Aql and S Mus, we performed a preliminary orbital fit combining their astrometric measurements with newly obtained high-precision single-line radial velocities, providing the full set of orbital elements and pulsation parameters. Assuming the distance from a period-luminosity (P-L) relation for both Cepheids, we estimated preliminary masses of MU Aql = 4.97 ± 0.62 M⊙ and MS Mus = 4.63 ± 0.99 M⊙. For YZ Car, W Sgr, V350 Sgr, and V636 Sco, we revised the spectroscopic orbits using new high-precision radial velocities, while we updated the pulsation parameters for BP Cir, BG Cru, S Nor, and AH Vel. Our interferometric observations also provide measurements of the angular diameters, which can be used in a Baade-Wesselink type analysis. Conclusions. We now have several astrometric detections of Cepheid companions. When radial velocities of the companions are available, such systems will provide accurate and independent masses and distances. Orbital parallaxes with an accuracy better than 5% will be particularly useful for a better calibration of the P-L relation. The final Gaia parallaxes will also be particularly helpful for single-line spectroscopic systems, where mass and distance are degenerate. Mass measurements are necessary for a better understanding of the age and evolution of Cepheids.

scholarly journals A Multi-Counter System for High Precision Carbon-14 Measurements

Radiocarbon ◽  
1980 ◽  
Vol 22 (2) ◽  
pp. 442-447 ◽  
Author(s):  
Hildegard Schoch ◽  
Michael Bruns ◽  
Karl Otto Münnich ◽  
Marianne Münnich
Keyword(s):  
Data Acquisition ◽  
High Precision ◽  
Counting Rate ◽  
Standard Samples ◽  
Carbon 14 ◽  
Laboratory Techniques ◽  
Counting Time ◽  
Precision Level ◽  
Recent Developments ◽  
Better Than

A new 14C detector system containing nine, independently working, CO2 proportional counters is described. The system is designed for a sufficient measuring capacity at a precision level better than σ = ± 2‰, which requires a counting time of about one week per sample. The size of the installation requires a simple and economic design of counters and electronics. A single anticoincidence shield for all counters consists of five newly developed flat counters. The modern counting rate (52cpm) is sensitively checked by running Heidelberg sodium carbonate standard samples wth a counting rate of about 10 times modern. A microcomputer (DEC PDP-11 /03) is used for data acquisition. Recent developments in laboratory techniques (preparation and gaschromatographic purification of samples) are also reported.

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