N and O isotope (δ 15 Nα , δ 15 Nβ , δ 18 O, δ 17 O) analyses of dissolved NO3 − and NO2 − by the Cd-azide reduction method and N2 O laser spectrometry

2018 ◽  
Vol 32 (3) ◽  
pp. 184-194 ◽  
Author(s):  
Leonard I. Wassenaar ◽  
Cedric Douence ◽  
Mark A. Altabet ◽  
Pradeep K. Aggarwal
Keyword(s):  
Reduction Method ◽  
Laser Spectrometry ◽  
O Isotope

Effect of different soil textures and saturation levels on the equilibration time of oxygen isotopes using the direct liquid-vapor equilibration method

2021 ◽  
Author(s):  
Devakunjari Vadibeler ◽  
Michael Stockinger ◽  
Christine Stumpp
Keyword(s):  
Tap Water ◽  
Saturation Level ◽  
Equilibration Time ◽  
Sample Storage ◽  
Stable Water Isotopes ◽  
Laser Spectrometry ◽  
O Isotope ◽  
The Impact ◽  
Isotopic Measurements ◽  
Liquid Vapor

<p>Stable water isotopes of oxygen (d<sup>18</sup>O) are used as tracers to study soil pore water. One method to measure d<sup>18</sup>O of soil samples is the direct liquid-vapor equilibration (DLVE) method. In this method, test samples are stored in Ziploc bags and equilibrated for three days. After equilibration, the headspace gas is measured using laser spectrometry. The DLVE method requires minimum sample handling, enables direct isotopic measurements without the need of extracting the water, and is highly reliable and comparatively cheaper than other measurement methods. However, the influence of different soil textures and saturation levels on the δ<sup>18</sup>O isotope when using the DLVE method is not well understood yet. In this study, three different soil textures (sand, organic carbon rich silt and kaolinite) were oven-dried for three days at 105<sup>°</sup>C and saturated to different saturation levels (100%, 80%, 60% and 40%) in laboratory cylinders for a week. The samples were saturated using tap water of known isotopic value and stored in Ziploc bags for different amounts of time. The samples were analyzed after 1, 2, 3, 4 and 7 days using cavity ring down spectroscopy (CRDS), and the isotopic ratios recorded after storage were compared with the isotopic measurements obtained before the sample equilibration. The resulting isotopic deviations were less than the CRDS measurement precision after one day of sample storage for sandy soil regardless of their saturation levels. Likewise, one day was also adequate for 100%, 80% and 40% saturated kaolinite, with 100% saturation allowing for up to seven days of sample storage with only small isotopic deviations (±0.43‰). Contrary to this, for organic-silty soil the required equilibration time depended on the saturation level. The findings from this laboratory-based analysis enhance the understanding of the impact of soil texture and saturation level on the DLVE method.</p>

scholarly journals Measuring stable isotopes of hydrogen and oxygen in ice by means of laser spectrometry: the Bølling transition in the Dye-3 (south Greenland) ice core

2002 ◽  
Vol 35 ◽  
pp. 125-130 ◽  
Author(s):  
Radboud van Trigt ◽  
Harro A. J. Meijer ◽  
Arny E. Sveinbjörnsdóttir ◽  
Sigfús J. Johnsen ◽  
Erik R.Th. Kerstel
Keyword(s):  
Mass Spectrometry ◽  
Isotope Ratio ◽  
Ice Core ◽  
Isotope Ratio Mass Spectrometry ◽  
Direct Absorption ◽  
Deuterium Excess ◽  
Laser Spectrometry ◽  
O Isotope ◽  
A New Technique ◽  
Better Than

AbstractWe report on the first application of a new technique in ice-core research, based on direct absorption infrared laser spectrometry (LS), for measuring 2H, 17Oand 18O isotope ratios. the data are used to calculate the deuterium excess d (defined as δ2H– 8δ18O) for a section of the Dye-3 (south Greenland) deep ice core around the Bølling transition (14 500 BP). the precision of LS is slightly better than that of most traditional methods for deuterium, but not for the oxygen isotopes. the ability to measure δ17O is new and is used here to improve the precision of the δ18O determination. Still, the final precision for δ18O remains inferior to traditional isotope ratio mass spectrometry (IRMS). Therefore, deuterium excess was calculated from a combination of the LS and IRMS isotope determinations.

Type -Reduction Method on Fuzzy Critical Path

2019 ◽  
Vol 7 (1) ◽  
pp. 256-259
Author(s):  
P.Balasowandari ◽  
Dr. V.Anusuya
Keyword(s):  
Reduction Method ◽  
Critical Path ◽  
Type Reduction

Current Reduction Method for Dual Active Bridge Converter in Non-linear Dead-time Compensation Method

2020 ◽  
Vol 140 (3) ◽  
pp. 175-183
Author(s):  
Kengo Kawauchi ◽  
Hayato Higa ◽  
Hiroki Watanabe ◽  
Keisuke Kusaka ◽  
Jun-ichi Itoh
Keyword(s):  
Reduction Method ◽  
Dead Time ◽  
Compensation Method ◽  
Dual Active Bridge ◽  
Non Linear ◽  
Dead Time Compensation ◽  
Current Reduction

System Reduction Method Using Spectrum of Power Oscillation Waveform

2015 ◽  
Vol 135 (4) ◽  
pp. 241-250 ◽  
Author(s):  
Hideo Koseki ◽  
Masaki Nagata ◽  
Hideo Hosogoe ◽  
Hiroshi Takada ◽  
Takanori Shuto ◽  
...  
Keyword(s):  
Reduction Method ◽  
Power Oscillation ◽  
System Reduction
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