scholarly journals An Advanced Method to Estimate Deep Currents from Profiling Floats

2005 ◽  
Vol 22 (8) ◽  
pp. 1294-1304 ◽  
Author(s):  
Jong Jin Park ◽  
Kuh Kim ◽  
Brian A. King ◽  
Stephen C. Riser
Keyword(s):  
Indian Ocean ◽  
Accurate Determination ◽  
New Method ◽  
Advanced Method ◽  
Subsurface Ocean ◽  
Least Squares Fit ◽  
Geostrophic Shear ◽  
The Mean ◽  
Better Than

Abstract Subsurface ocean currents can be estimated from the positions of drifting profiling floats that are being widely deployed for the international Argo program. The calculation of subsurface velocity depends on how the trajectory of the float while on the surface is treated. The following three aspects of the calculation of drift velocities are addressed: the accurate determination of surfacing and dive times, a new method for extrapolating surface and dive positions from the set of discrete Argos position fixes, and a discussion of the errors in the method. In the new method described herein, the mean drift velocity and the phase and amplitude of inertial motions are derived explicitly from a least squares fit to the set of Argos position fixes for each surface cycle separately. The new method differs from previous methods that include prior assumptions about the statistics of inertial motions. It is concluded that the endpoints of the subsurface trajectory can be estimated with accuracy better than 1.7 km (East Sea/Sea of Japan) and 0.8 km (Indian Ocean). All errors, combined with the error that results from geostrophic shear and extrapolation, should result in individual subsurface velocity estimates with uncertainty of the order of 0.2 cm s−1.

Dosage du Sr-90 dans l'eau des lacs et des rivières du Québec par précipitation avec l'oxine et comptage β

1988 ◽  
Vol 66 (1) ◽  
pp. 174-177 ◽  
Author(s):  
E. Haddad ◽  
L. Zikovsky
Keyword(s):  
Detection Limit ◽  
Surface Waters ◽  
New Method ◽  
The Mean ◽  
Better Than

A new method for the determination of Sr-90 dissolved in surface waters has been developed. It is based on the precipitation of Sr with 8-hydroxyquinoline at pH 11.3 and counting of β particles with energy above 150 keV. The detection limit obtained is 0.5 mBq/L and the mean yield is 28%. The decontamination factors from other β emitters achieved are better than 10 000. This method has been used to measure the Sr-90 in 5 lakes and 5 rivers in Québec and activities ranging from 3 to 15 mBq/L were obtained. This new method is as efficient and reliable as conventional techniques while being less tedious.

K, Ca, Mg, and Zn in platelets, as determined by atomic absorption spectrometry with use of a sealed decomposition bomb and discrete nebulization.

1985 ◽  
Vol 31 (4) ◽  
pp. 609-612 ◽  
Author(s):  
T Makino
Keyword(s):  
Metal Ions ◽  
Atomic Absorption Spectrometry ◽  
Atomic Absorption ◽  
Accurate Determination ◽  
Absorption Spectrometry ◽  
New Method ◽  
Differential Centrifugation ◽  
Individual Variations

Abstract In this new method for precise and accurate determination of K, Ca, Mg, and Zn in platelets, small amounts of platelets, prepared by differential centrifugation and cell washing, are decomposed in a homemade mini-vessel, a sealed Teflon bomb. The metal ions in the decomposed sample are measured by atomic absorption spectrometry with discrete nebulization. Overall, CVs ranged from 0.8 to 4.8%. We investigated sex-related differences (none were found) and intra-individual variations.

scholarly journals Sulfur dioxide layer height retrieval from Sentinel-5 Precursor/TROPOMI using FP_ILM

2019 ◽  
Vol 12 (10) ◽  
pp. 5503-5517 ◽  
Author(s):  
Pascal Hedelt ◽  
Dmitry S. Efremenko ◽  
Diego G. Loyola ◽  
Robert Spurr ◽  
Lieven Clarisse
Keyword(s):  
Sulfur Dioxide ◽  
Accurate Determination ◽  
Volcanic Eruptions ◽  
Critical Parameters ◽  
Layer Height ◽  
Learning Machine ◽  
The Impact ◽  
First Time ◽  
Better Than

Abstract. The accurate determination of the location, height, and loading of sulfur dioxide (SO2) plumes emitted by volcanic eruptions is essential for aviation safety. The SO2 layer height is also one of the most critical parameters with respect to determining the impact on the climate. Retrievals of SO2 plume height have been carried out using satellite UV backscatter measurements, but, until now, such algorithms are very time-consuming. We have developed an extremely fast yet accurate SO2 layer height retrieval using the Full-Physics Inverse Learning Machine (FP_ILM) algorithm. This is the first time the algorithm has been applied to measurements from the TROPOMI instrument onboard the Sentinel-5 Precursor platform. In this paper, we demonstrate the ability of the FP_ILM algorithm to retrieve SO2 plume layer heights in near-real-time applications with an accuracy of better than 2 km for SO2 total columns larger than 20 DU. We present SO2 layer height results for the volcanic eruptions of Sinabung in February 2018, Sierra Negra in June 2018, and Raikoke in June 2019, observed by TROPOMI.

Determination of Ibuprofen in Human Plasma and Urine by Gas Chromatography/Mass Spectrometry

2014 ◽  
Vol 97 (2) ◽  
pp. 415-420 ◽  
Author(s):  
Bilal Yilmaz ◽  
Ali Fuat Erdem
Keyword(s):  
Human Plasma ◽  
Internal Standard ◽  
Gas Chromatography Mass Spectrometry ◽  
Oral Tablet ◽  
Liquid Liquid Extraction ◽  
Human Plasma And Urine ◽  
The Mean ◽  
Interday Precision ◽  
Better Than

Abstract This paper describes a GC/MS method for the determination of ibuprofen in human plasma and urine. Ibuprofen and internal standard naproxen were extractedfrom plasma and urine by using a liquid–liquid extraction method. Derivatization was carried outusing N-methyl-N-(trimethylsilyl) trifluoroacetamide. Calibration curves were linear over the concentration range of 0.05–5.0 and 0.1–10.0 μg/mL for plasma and urine, respectively. Intraday and interday precision (RSD) values for ibuprofen in plasma and urine were less than 6.31%, and accuracy (relative error) was better than 12.00%. The mean recovery of ibuprofen was 89.53% for plasma and 93.73% for urine. TheLOD was 0.015 and 0.03 μg/mL and the LOQ was 0.05 and 0.1 μg/mL for plasma and urine, respectively. The method was successfully applied to blood samples from three healthy male volunteers who had been given an oral tablet of 600 mg ibuprofen.

Salt-affected land in the shire of Wongan-Ballidu, Western Australia

Soil Research ◽  
1981 ◽  
Vol 19 (1) ◽  
pp. 87 ◽  
Author(s):  
RA Nulsen
Keyword(s):  
Survey Methods ◽  
Accurate Determination ◽  
Test Area ◽  
Affected Area ◽  
The Road ◽  
Farm Survey ◽  
The Mean ◽  
Secondary Salinity ◽  
On Farm

A survey was conducted to measure the total area of salt affected land in the Wongan-Ballidu Shire. Initially two survey methods were used: an intense on-farm survey and a broadscale road traverse survey. In the test area there was no net difference in areas of salt land detected by the two survey methods. and the remainder of the shire was surveyed by the road traverse method. Difficulties in objective delineation of areas of primary and secondary salinity precluded accurate determination of each, and only the total salt-affected area could be measured. The total area was 51,975 ha. representing 15.4% of the shire area. Detailed surveys of three 2080 ha sites in the shire showed that in the 18 years between 1958 and 1976 the area of salt land increased by up to 237% with the mean area within sites increasing from 206 ha in 1958 to 541 ha in 1976.

scholarly journals Hipparcos, Three Years After Launch

1993 ◽  
Vol 156 ◽  
pp. 1-10
Author(s):  
J. Kovalevsky ◽  
M. Froeschlé
Keyword(s):  
Standard Error ◽  
Present Status ◽  
Double Star ◽  
New Method ◽  
Standard Errors ◽  
First Year ◽  
Mass Determination ◽  
Mission Duration ◽  
The Mean

In a first part, the present status of the HIPPARCOS mission is described. Despite the degradations and failures of gyroscopes, it is still hoped that a 4 1/2 mission duration will be reached. The first-year of data has been reduced by both FAST and NDAC consortia. For the best 46200 observed stars, the distribution of standard errors in positions has a maximum of 1.5 mas in latitude and 1.8 mas in longitude and the mean standard error for parallaxes is of the order of 3 mas. The comparison of results obtained by both consortia shows that the differences are small and quite consistent with the announced internal precisions. Magnitude measurements are precise to 0.02 magnitude for a 4 second observation. The precision to be expected for double star observations is also given. The main new result is that the magnitudes of the components are obtained with a few hundredths of a magnitude precision. This allows to devise a new method of mass determination based upon the parallax and a recalibrated mass-luminosity diagram. The parallax dependence of the results is much more favourable than in the case of the classical determination of masses using orbital motions.

scholarly journals On phenomena relating to the spectra of hydrogen and helium

1916 ◽  
Vol 93 (646) ◽  
pp. 27-28
Keyword(s):  
Accurate Determination ◽  
Principal Series ◽  
Black Body ◽  
Black Body Radiation ◽  
Balmer Series ◽  
Mean Values ◽  
Carbon Arc ◽  
The Mean ◽  
The Individual

In a previous paper the structure of broadened spectrum lines was investigated by a method involving the use of a neutral-tinted wedge as an accessory to the spectroscope. The present communication deals with a method for the accurate determination of the photographic intensities of spectrum lines and the reduction of such intensities to absolute values by comparison with the continuous black-body radiation of the carbon arc. These methods have been applied to a study of the relative intensity distribution in the spectra of helium and hydrogen under different conditions of excitation. It has been found that under certain specified conditions there is a transfer of energy from the longer to the shorter wave-lengths in any given series, and that, under such conditions, the associated series, and in particular the Diffuse series, are relatively enhanced at the expense of the Principal series. It has also been found that the distribution of intensity found in certain celestial spectra can be approximately reproduced in the laboratory. In any attempt to interpret the phenomena observed in connection with the Balmer series of hydrogen, it is necessary to know the particular type to which this series belongs. In order to decide this point a study has been made of the separations of the components of lines of the Balmer series of hydrogen, and the mean values of the separations of the doublets constituting the lines H a and H β have been found to be respectively 0.132 Å.U. and 0.033 Å.U. These values are consistent with the separations appropriate to a Principal series, and the first is in precise agreement with the value deduced by Buisson and Fabry. These results have been obtained by crossing a Lummer Gehrcke plate with the neutral wedge, and submitting the contours obtained to mathematical analysis, by means of which the distribution of intensity in the individual components, and the separation of the components, can be determined.

A Method for Calculating the Index of Refraction of Thin Films

1975 ◽  
Vol 53 (18) ◽  
pp. 1737-1742 ◽  
Author(s):  
J. H. Wohlgemuth ◽  
D. E. Brodie
Keyword(s):  
Thin Films ◽  
Spectral Range ◽  
Variational Approach ◽  
Accurate Determination ◽  
Normal Incidence ◽  
Index Of Refraction ◽  
New Method ◽  
Reflection And Transmission ◽  
Transmission Measurements

A new method for determining the index of refraction from normal incidence reflection and transmission measurements has been developed. Several other methods are reviewed to explain why a new method is needed. The author's method used a thickness variational approach. For an accurate determination of n and k, the method requires normal incidence reflection and transmission measurements over a fairly broad spectral range for at least two different film thicknesses. These requirements are unavoidable for normal incidence methods.

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