The developed chromatographic system described her e, can be used for measurements of he-. lium concentrat ion in gr oundwater. The obtained level of helium detection for groundwater. samples of ...

The helium analyser should have a range of ∼0–10% helium, a resolution of ≤0.01% helium over the entire range, and a 95% response time of <15 s to a 2% step change in helium concentration in the breathing circuit. …

1. The simplified helium method for measuring the FRC is described and results obtained in normal and emphysematous subjects are presented. 2. Minute-to-minute changes in helium concentration during the …

Abstract Rainbow schlieren deflectometry (RSD) is applied to acquire quantitative concentration measurements in a turbulent environment for the first time. RSD methodology is developed and validated using Rayleigh scattering data available in the literature. Experiments were performed in an initially laminar, momentum-driven …

Helium purification system configuration of HTR-PM and radiation monitoring channels for primary coolant. ... In this study, we focused on the design of the activation concentration measurement of gaseous fission products in the primary coolant of HTR-PM using an online gross γ monitoring instrument of nuclear safety class, which can …

Helium concentrations in W fuzz layers are measured at 1–4 at.%, which is lower than expected for the observed sub-surface voids to be filled with several GPa of helium pressure.

Touch Screen Helium Concentration Tester. LACO's LHCT03D Helium Concentration Tester is designed to measure helium concentration in production parts previously filled with helium gas. Working in …

A minimum helium concentration of 0.3 mol% is needed for the commercial separation of helium from marketable natural gas (National Research Council, 2010). However, helium concentrations as low as 0.04 mol% can be economic if gas is chilled and purified to meet specifications as liquefied natural gas (National Research …

Measurements of the 4 He/N 2 ratio in 46 high-pressure samples of archived old air using a new mass spectrometric technique 25 reveal an atmospheric build-up of 4 He of 0.042 ± 0.003‰ yr −1 ...

An approach is considered for organizing indirect measurements of nitrogen and helium in liquid fuel components based on creating an equilibrium distribution between vapor-gas and liquid phases, determination of temperature, pressure, and thermal conductivity of the equilibrium vapor phase, followed by calculation using Henry constants.

A helium content of 5.222 + or - 0.017 ppm by volume has been established by measurements during 1981 of the earth's lower atmosphere, using isotope dilution mass spectrometry. This compares well with the currently accepted value of 5.239 + or - 0.004 ppm determined by Gluekhauf (1946) on the basis of measurements conducted in the …

David R Baldwin a. Dr D R Baldwin. Abstract. BACKGROUND The two most commonly used methods for the measurement of lung volumes are helium dilution and body plethysmography. Two methods have been …

Combining earlier measurements of helium at lower dpa levels with knowledge of the 59 Ni behavior we can extrapolate to higher dpa levels since the helium concentration is an excellent retrospective dosimeter of the thermal fluence. Predictions of hydrogen are more difficult, however, due to helium-nucleated cavities storing both …

If the volume and concentration of helium in the gas mixture rebreathed are known, measurement of the final equilibrium concentration of helium permits calculation of the …

Helium also exists in concentrations as high as 8 percent in certain natural gases. Most U.S. helium-rich natural gas is located in the Hugoton-Panhandle field in Texas, Oklahoma, and Kansas; the LaBarge field in the Riley Ridge area of Wyoming; and the federal facility in the Cliffside field near Amarillo, Texas . Generally, natural gas ...

The concentration of helium in tungsten fuzz-like nanostructures has been measured by means of thermal desorption spectroscopy. Fuzz was formed on the W surface under intensive plasma irradiation at 1500 K. The helium content was measured first in the as-irradiated sample, and then in a similar sample with the fuzz mechanically …

Outputs from the SAW thermal sensor are the resonant frequency shifts that depend on the temperature coefficient of LiNbO 3.In Fig. 2, we show the model predictions of the frequency shifts after the sensor is exposed to air/helium mixtures for 10 s versus helium concentration at three flow rates. Based on the model predictions, the SAW …

These measurements provide crucial validation to space weather models, support predictions of peak number density ( ~ 1 cm −3) and the dependence of density …

CONCENTRATION METERS. To be used for helium concentrations measures from 1 to . Mainly for helium concentration measurement for the "Envelope method" tightness control. Thermal conductivity cell with no routine recalibratione; Built-in batteries supply, autonomy about 6H;

We measured the concentration of helium with a katharometer (Godart, response time 0.1 sec), at the expiration port of a Siemens-Elema-900 ventilator. ... An open-circuit helium method for measuring functional residual capacity and defective intrapulmonary gas mixing. J Clin Invest. 1954; 33: 1277-1286. View in Article Scopus (12) ...

The measurement is made by determining the amount of an indicator gas, expired in a large number of breaths. The quantity M of the indicator gas (in our case helium) expired in n breaths can be given by (1) M He = ∑ I = 1 n V 1 • F He (1) where F He (1) is the concentration of helium in the i-th breath and V 1 is the volume

@article{osti_1897986, title = {Dynamic measurement of the helium concentration of evolving tungsten nanostructures using Elastic Recoil Detection during plasma exposure}, author = {Woller, K. B. and Whyte, D. G. and Wright, G. M.}, abstractNote = {Helium (He) concentration depth profiles of evolving tungsten (W) …

This is accomplished by applying the quantitative rainbow schlieren deflectometry technique to optically measure the local helium mole percentage across the whole field. Data were acquired over downstream locations extending from tube exit to about 3.0d (d=31.8 or 19.1 mm is the jet tube inside diameter) at spatial resolution of 0.14 …

The method for measuring lung volumes is based on the equilibration of gas in the lung with a known volume of gas containing helium 31, 32. The test gas consists of air with added oxygen of 25–30%, but higher concentrations are acceptable. Helium is added to a concentration of ∼10% (full scale) 9.

The temperature measurements confirm the expected flame temperatures of approximately 1800, 1630, 1560, and 1530 K for the four pressures, respectively. The decreasing temperature results from an increasing concentration of helium in the air mixture of 0.510, 0.600, 0.635, and 0.650 at 2, 4, 6, and 8 atm, respectively.

The dilution principle – measurement of fluid compartment volume; Diffusing capacity; Compliance; Bohr equation; Alveolar ventilation equation; Alveolar gas equation; Helium …

As an illustration we are doing the simple following calculation: for a helium flow rate of 210 NL.min −1 a hydrogen flow rate of 218 NL.min −1 and the 4 mm injection diameter, the ratio of measured helium and hydrogen concentrations should induce a ratio of interface height of 1.09.

A new capability to not only measure the absolute helium concentration but also measure the 3 He/ 4 He isotopic ratio simultaneously with the H/D/T ratio was commissioned and taken into routine operation. The accuracy limit of the helium concentration can be as good as 0.1 %, but reduces to 0.5–1 % for 4 He in the presence

crustal rocks.1 The terrestrial atmosphere contains helium with a concentration of 5.24 ppm by volume.2 This is attributable to the balance between the supply from the solid Earth (mantle and crust) and escape from the top of the atmosphere into space.3 Since the residence time of helium in the atmosphere is

Measurement •The helium concentration is noted every 15 s and equilibration is considered to be complete –Change in helium concentration is < 0.02% for 30 s –Change in FRC is …