scholarly journals Atmospheric CO<sub>2</sub>, CH<sub>4</sub>, and CO with the CRDS technique at the Izaña Global GAW station: instrumental tests, developments, and first measurement results

2019 ◽  
Vol 12 (4) ◽  
pp. 2043-2066 ◽  
Author(s):  
Angel J. Gomez-Pelaez ◽  
Ramon Ramos ◽  
Emilio Cuevas ◽  
Vanessa Gomez-Trueba ◽  
Enrique Reyes
Keyword(s):  
Flow Rate ◽  
Random Noise ◽  
Least Square ◽  
Spatial Inhomogeneity ◽  
Inlet Pressure ◽  
Processing Scheme ◽  
Linear Relationships ◽  
Least Square Fit

Abstract. At the end of 2015, a CO2/CH4/CO cavity ring-down spectrometer (CRDS) was installed at the Izaña Global Atmosphere Watch (GAW) station (Tenerife, Spain) to improve the Izaña Greenhouse Gases GAW Measurement Programme, and to guarantee the renewal of the instrumentation and the long-term maintenance of this program. We present the results of the CRDS acceptance tests, the raw data processing scheme applied, and the response functions used. Also, the calibration results, the implemented water vapor correction, the target gas injection statistics, the ambient measurements performed from December 2015 to July 2017, and their comparison with other continuous in situ measurements are described. The agreement with other in situ continuous measurements is good most of the time for CO2 and CH4, but for CO it is just outside the GAW 2 ppb objective. It seems the disagreement is not produced by significant drifts in the CRDS CO World Meteorological Organization (WMO) tertiary standards. The more relevant contributions of the present article are (1) determination of linear relationships between flow rate, CRDS inlet pressure, and CRDS outlet valve aperture; (2) determination of a slight CO2 correction that takes into account changes in the inlet pressure/flow rate (as well as its stability over the years), and attributing it to the existence of a small spatial inhomogeneity in the pressure field inside the CRDS cavity due to the gas dynamics; (3) drift rate determination for the pressure and temperature sensors located inside the CRDS cavity from the CO2 and CH4 response function drift trends; (4) the determination of the H2O correction for CO has been performed using raw spectral peak data instead of the raw CO provided by the CRDS and using a running mean to smooth random noise in a long water-droplet test (12 h) before performing the least square fit; and (5) the existence of a small H2O dependence in the CRDS flow and of a small spatial inhomogeneity in the temperature field inside the CRDS cavity are pointed out and their origin discussed.

Least-square refinement of structure parameters from CBED integrated intensities: application to determination of temperature factors in Y BA2CU3O7

1992 ◽  
Vol 50 (2) ◽  
pp. 1456-1457
Author(s):  
Kjersti Gjønnes ◽  
Jon Gjønnes
Keyword(s):  
Least Square ◽  
Measured Intensity ◽  
Structure Information ◽  
Accurate Temperature ◽  
Least Square Fit ◽  
Case Application ◽  
Integrated Intensities ◽  
Temperature Factors ◽  
Narrow Bands

Electron diffraction intensities can be obtained at large scattering angles (sinθ/λ ≥ 2.0), and thus structure information can be collected in regions of reciprocal space that are not accessable with other diffraction methods. LACBED intensities in this range can be utilized for determination of accurate temperature factors or for refinement of coordinates. Such high index reflections can usually be treated kinematically or as a pertubed two-beam case. Application to Y Ba2Cu3O7 shows that a least square refinememt based on integrated intensities can determine temperature factors or coordinates.LACBED patterns taken in the (00l) systematic row show an easily recognisable pattern of narrow bands from reflections in the range 15 < l < 40 (figure 1). Integrated intensities obtained from measured intensity profiles after subtraction of inelastic background (figure 2) were used in the least square fit for determination of temperature factors and refinement of z-coordinates for the Ba- and Cu-atoms.

scholarly journals Atmospheric CO2, CH4, and CO with CRDS technique at the Izaña Global GAW station: instrumental tests, developments and first measurement results

2017 ◽  
Author(s):  
Angel J. Gomez-Pelaez ◽  
Ramon Ramos ◽  
Emilio Cuevas ◽  
Vanessa Gomez-Trueba ◽  
Enrique Reyes
Keyword(s):  
Drift Rate ◽  
Inlet Pressure ◽  
Response Functions ◽  
Measurement Results ◽  
Ambient Measurements ◽  
Acceptance Tests ◽  
Term Maintenance

Abstract. At the end of 2015, a CO2/CH4/CO Cavity Ring-Down Spectrometer (CRDS) was installed at the Izaña Global Atmosphere Watch station (Tenerife, Spain) to improve the Izaña Greenhouse gases GAW measurement programme, and to guarantee the renewal of the instrumentation and the long-term maintenance of this programme. We present the results of the CRDS acceptance tests, the processing of raw data applied through novel numerical codes, and the response functions used. Also, the calibration results, the implemented water vapour correction, the target gas injection statistics, the ambient measurements performed from December 2015 to July 2017, and their comparison with other continuous in situ measurements are described. The agreement with other in situ continuous measurements is good most of the time for CO2 and CH4, but for CO is just outside the GAW 2-ppb objective. It seems the disagreement is not produced by significant drifts in the CRDS CO WMO tertiary standards. The main novelties are: 1) determination of a slight CO2 correction that takes into account changes in the inlet pressure/flow rate; 2) detailed justification of the use of virtual tanks to monitor the response function changes in time; 3) drift rate determination for the pressure and temperature sensors located inside the CRDS cavity; 4) novelties in the determination of the H2O correction for CO; and 5) determination and discussion of the origin of the CRDS-flow inlet pressure and H2O dependences.

scholarly journals The Mie representation for Mercury’s magnetic field

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
S. Toepfer ◽  
Y. Narita ◽  
K. -H. Glassmeier ◽  
D. Heyner ◽  
P. Kolhey ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Data ◽  
Least Square ◽  
Simulation Code ◽  
Magnetic Field Data ◽  
Least Square Fit ◽  
High Precision Determination ◽  
The Magnetic Field ◽  
Magnetospheric Field

AbstractThe parameterization of the magnetospheric field contribution, generated by currents flowing in the magnetosphere is of major importance for the analysis of Mercury’s internal magnetic field. Using a combination of the Gauss and the Mie representation (toroidal–poloidal decomposition) for the parameterization of the magnetic field enables the analysis of magnetic field data measured in current carrying regions in the vicinity of Mercury. In view of the BepiColombo mission, the magnetic field resulting from the plasma interaction of Mercury with the solar wind is simulated with a hybrid simulation code and the internal Gauss coefficients for the dipole, quadrupole and octupole field are reconstructed from the data, evaluated along the prospective trajectories of the Mercury Planetary Orbiter (MPO) using Capon’s method. Especially, it turns out that a high-precision determination of Mercury’s octupole field is expectable from the future analysis of the magnetic field data measured by the magnetometer on board MPO. Furthermore, magnetic field data of the MESSENGER mission are analyzed and the reconstructed internal Gauss coefficients are in reasonable agreement with the results from more conventional methods such as the least-square fit.

Brackish Water Desalination by Electrodialysis: CaCO3 Scaling Monitoring During Batch Recirculation Operation

2013 ◽  
Vol 11 (1) ◽  
pp. 517-525 ◽  
Author(s):  
Ilhem Ben Salah Sayadi ◽  
Philippe Sistat ◽  
Mohamed Ben Amor ◽  
Mohamed Tlili
Keyword(s):  
Water Quality ◽  
Flow Rate ◽  
Water Systems ◽  
Precise Determination ◽  
Water Desalination ◽  
Process Efficiency ◽  
Feed Water ◽  
Crystallization Onset

Abstract The composition of feed water used in electrodialysis (ED) desalination causes the risk of CaCO3 scale crystallization in ED equipments, which leads to the decrease of process efficiency. To control scaling in water systems, several scaling indices and tests, permitting to predict the scaling occurrence, have been devised. In this study, an accelerated scaling test allowing to follow CaCO3 formation in water desalination plant using ED process was proposed. Tests were performed using a pilot unit as a conventional ED in batch recirculation mode. By simple in situ measurements of pH and flow rate of the concentrate, the crystallization onset and growth of CaCO3 were followed during the pilot operation. This leads to precise determination of the number of concentrate recirculation times and therefore to the highest recovery rate without scaling risk as a function of the inlet water quality and the antiscale pretreatment.

On the Buckley-Leverett Equation With Constant-Pressure Boundary Conditions

SPE Journal ◽  
2016 ◽  
Vol 21 (06) ◽  
pp. 2301-2307 ◽  
Author(s):  
Thormod E. Johansen ◽  
Lesley A. James ◽  
Xiaolong Liu
Keyword(s):  
Analytical Solution ◽  
Flow Rate ◽  
Constant Pressure ◽  
Analytical Determination ◽  
Constant Flow Rate ◽  
Displacement Front ◽  
Constant Rate ◽  
Volumetric Flux

Summary The classical Buckley-Leverett theory applies to 1D linear flow of two immiscible phases under the fundamental assumption that the flow rate (or total volumetric flux) is constant as a function of time. One phase is injected into the medium at a constant rate, thereby displacing the other phase. If the displacing phase is instead injected at constant pressure and the outlet pressure is also constant, the problem is still well-defined; however, the classical Buckley-Leverett theory does not apply. This is because the injected phase and the in-situ phase have different properties such as viscosities. If the boundary pressures are kept constant, the flow rate will, therefore, vary over time. The main result of this paper is to show that the solution of the displacement problem can be obtained from the constant-rate solution through an analytical determination of the flow rate as a function of time, given constant-pressure boundaries. The theory developed in this paper also provides an analytical solution for the location of the displacement front at any given time, the time for frontal breakthrough at the outlet end, and the pressure distribution as a function of time inside the medium. It is demonstrated through computed examples that the constant-flow-rate solution, in general, cannot be used to approximate the corresponding solution for constant-pressure boundaries because the variation in the flow rate is very significant. A standard numerical method has also been applied and compared with the analytical solutions, demonstrating that fine numerical-simulation grids are required for acceptable comparison with the analytical solution.

LEAST SQUARES DETERMINATION OF THE VELOCITY FUNCTION V=V0+kz FOR ANY SET OF TIME DEPTH DATA

Geophysics ◽  
1943 ◽  
Vol 8 (4) ◽  
pp. 356-361 ◽  
Author(s):  
J. A. Legge ◽  
J. J. Rupnik
Keyword(s):  
Least Squares ◽  
Least Square ◽  
Actual Case ◽  
Velocity Function ◽  
Depth Data ◽  
Least Square Fit ◽  
Ray Path

A method is presented by means of which a least square fit of the circular ray path plotting function to time‐depth data is obtained. An example is worked out illustrating the application of the method to an actual case.

The Determination of In-Situ Film Hole Flow Rates Using a Transient Thermal Inertia Method

2003 ◽  
Author(s):  
Ronald S. Bunker ◽  
Sarah J. Osgood ◽  
Nirm V. Nirmalan
Keyword(s):  
Flow Rate ◽  
Internal Heat ◽  
Transient Behavior ◽  
Flow Area ◽  
Local Flow ◽  
Flow Rates ◽  
Discharge Coefficients ◽  
Thermal Transient

Film hole flow rates are conventionally characterized by a discharge coefficient relating the actual mass flow rate to the theoretical ideal flow rate based upon some measured effective hole diameter or flow area. These discharge coefficients are typically measured on controlled test plates that contain the particular size, shape, and fabrication method for an individual film hole type. Such discharge coefficients are then assumed to apply to all of the in-situ film holes of that type which are machined or formed in the as-fabricated cooled turbine component. The thermal-mechanical analysis of the component is then performed using these assumed values to calculate film hole flow rates. In practice however, every film hole in a cooled airfoil is different due to machine tool wear, surface curvatures, laser drift, coating variations, and local flow supply behavior. A new method has been developed and demonstrated which allows determination of the individual film hole flow rates in-situ for an as-fabricated component, thus avoiding the need for assumed discharge coefficients or highly detailed flow checks. This method uses the thermal transient characteristics of external surface points near an active film hole to determine the flow rate through the hole. An imaging Infrared system is used to record the component response to an induced thermal cooling transient in which the film hole internal heat transfer dominates the local thermal transient behavior. The characteristic of the non-dimensionalized thermal decay is related to the flow rate within each individual film hole using a limited calibration function. This method allows the rapid inspection and quantification of detailed film hole flows for actual parts, which data may then be used in the analysis and health monitoring of parts in operation.

Cylindrical probe with a variable heat flow rate: A new method for the determination of formation thermal conductivity

2013 ◽  
Vol 5 (4) ◽  
Author(s):  
Lev Eppelbaum ◽  
Izzy Kutasov
Keyword(s):  
Thermal Conductivity ◽  
Heat Flow ◽  
Flow Rate ◽  
Dry Density ◽  
Heat Flow Rate ◽  
Cylindrical Probe ◽  
Variable Heat ◽  
Variable Heat Flow

AbstractThe thermal conductivity of a geological formation is one of the important petrophysical parameters which are preferable to study in situ in geophysical well logs. A new technique for the determination of formation thermal conductivity has been developed. We assumed that formation dry density, porosity, and pore fluids saturations could be determined from core samples or cuttings. In this case the specific heat and density of a formation can be quantitatively estimated. It is also assumed that the instantaneous heat flow rate and time data are available for a cylindrical probe with a variable heat flow rate placed in a wellbore. A semi-theoretical equation describing the temperature of the probe’s wall is used to determine in situ the formation conductivity as a function of the temperature increase. The formation thermal diffusivity is also calculated. A field example is presented.

INDIREKTE PAPIERCHROMATOGRAPHISCHE METHODE ZUR BESTIMMUNG DER HARNOESTROGENE

1961 ◽  
Vol 38 (4) ◽  
pp. 545-562 ◽  
Author(s):  
L. Kecskés ◽  
F. Mutschler ◽  
I. Glós ◽  
E. Thán ◽  
I. Farkas ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Granulosa Cell ◽  
Iron Content ◽  
List Type ◽  
Granulosa Cell Tumour ◽  
Hydrolysis Of ◽  
Phenol Fraction ◽  
Qualitative Determination

ABSTRACT 1. An indirect paperchromatographic method is described for separating urinary oestrogens; this consists of the following steps: acidic hydrolysis, extraction with ether, dissociation of phenol-fractions with partition between the solvents. Previous purification of phenol fraction with the aid of paperchromatography. The elution of oestrogen containing fractions is followed by acetylation. Oestrogen acetate is isolated by re-chromatography. The chromatogram was developed after hydrolysis of the oestrogens 'in situ' on the paper. The quantity of oestrogens was determined indirectly, by means of an iron-reaction, after the elution of the iron content of the oestrogen spot, which was developed by the Jellinek-reaction. 2. The method described above is satisfactory for determining urinary oestrogen, 17β-oestradiol and oestriol, but could include 16-epioestriol and other oestrogenic metabolites. 3. The sensitivity of the method is 1.3–1.6 μg/24 hours. 4. The quantitative and qualitative determination of urinary oestrogens with the above mentioned method was performed in 50 pregnant and 9 non pregnant women, and also in 2 patients with granulosa cell tumour.

DETERMINATION OF THE LIMITING FLOW RATE IN LIQUID FILMS FOR HEAT TRAHSFER CRISIS CALCULATION

1978 ◽  
Author(s):  
V. M. Borishansky ◽  
A.A. Andreevsky ◽  
Mikhail Ya. Belenkiy ◽  
G.S Bykov ◽  
Mikhail Gotovskii ◽  
...  
Keyword(s):  
Flow Rate ◽  
Liquid Films
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