Two Reliable Calibration Methods for accurate in-situ U-Pb dating of Scheelite

2022 ◽  
Author(s):  
Yanwen Tang ◽  
Junjie Han ◽  
Tingguang Lan ◽  
Jianfeng Gao ◽  
Liang Liu ◽  
...  
Keyword(s):  
Hydrothermal Deposits ◽  
Calibration Methods

Scheelite is an important metal mineral in W-related hydrothermal deposits and can be utilized as a reliable geochronometer to directly date the timing of mineralization. Up to now, two previous...

Calibration Methods to Circumvent Unknown Component Spectra for Quantitative in situ Raman Monitoring of Co-Polymerisation Reaction

2021 ◽  
Author(s):  
Wendy Rusli ◽  
Pavan Kumar Naraharisetti ◽  
Wee Chew
Keyword(s):  
Raman Spectroscopy ◽  
Reaction Monitoring ◽  
The Past ◽  
In Situ Raman ◽  
Calibration Methods ◽  
Unknown Component

The use of Raman spectroscopy for reaction monitoring has been successfully applied over the past few decades. One complication in such usage is the applicability for quantitative reaction studies. This...

Uncertainties of spectral in situ measurements in wastewater using different calibration approaches

2006 ◽  
Vol 53 (12) ◽  
pp. 187-197 ◽  
Author(s):  
L. Rieger ◽  
G. Langergraber ◽  
H. Siegrist
Keyword(s):  
Suspended Solids ◽  
Wastewater Treatment Plants ◽  
Total Suspended Solids ◽  
Data Sets ◽  
Global Calibration ◽  
Nitrite Nitrogen ◽  
Calibration Methods ◽  
Using Data ◽  
Nitrate And Nitrite

Three calibration methods were applied to UV/VIS spectra recorded in the influent of six wastewater treatment plants (WWTPs) to measure total COD (CODtot), filtered COD (CODfil), nitrate and nitrite nitrogen (NOx-N) and total suspended solids (TSS). It could be shown that a calibration of the sensor using data sets from four Swiss WWTPs leads to an improvement of the precision in comparison to the global calibration provided by the manufacturer. A calibration to the specific wastewater matrix always improves the results and gives the highest accuracy. For CODtot a mean coefficient of variation CVx of 12.5% could be reached, whereas for NOx-N only weak results were achieved (average CVx=36%).

scholarly journals Methods for Calibration of Specimen Temperature During In Situ Transmission Electron Microscopy Experiments

2020 ◽  
Vol 26 (1) ◽  
pp. 3-17 ◽  
Author(s):  
Fabrizio Gaulandris ◽  
Søren B. Simonsen ◽  
Jakob B. Wagner ◽  
Kristian Mølhave ◽  
Shun Muto ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Temperature Calibration ◽  
Transmission Electron ◽  
Calibration Methods ◽  
Scanning Transmission ◽  
Stem Temperature ◽  
Temperature Ranges ◽  
Technological Improvements

AbstractOne of the biggest challenges for in situ heating transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) is the ability to measure the local temperature of the specimen accurately. Despite technological improvements in the construction of TEM/STEM heating holders, the problem of being able to measure the real sample temperature is still the subject of considerable discussion. In this study, we review the present literature on methodologies for temperature calibration. We analyze calibration methods that require the use of a thermometric material in addition to the specimen under study, as well as methods that can be performed directly on the specimen of interest without the need for a previous calibration. Finally, an overview of the most important characteristics of all the treated techniques, including temperature ranges and uncertainties, is provided in order to provide an accessory database to consult before an in situ TEM/STEM temperature calibration experiment.

Developing Best Practices for Observing Global Surface Shortwave and Longwave Radiation across the Land and Ocean

2020 ◽  
Author(s):  
Robert Weller ◽  
Christian Lanconelli ◽  
Martin Wild ◽  
Joerg Trenmann
Keyword(s):  
Climate Models ◽  
Global Climate ◽  
Surface Radiation ◽  
Global Ocean ◽  
Radiation Balance ◽  
Radiative Fluxes ◽  
Temporal Sampling ◽  
The Earth ◽  
Calibration Methods

<p>In-situ shortwave or solar radiation and longwave or thermal radiation are observed at the earth’s surface on both the land and the ocean.  In addition, satellites are used to develop fields of surface radiation balance.  Planning for the Global Ocean Observing System (GOOS) and the Global Climate Observing System (GCOS) has identified surface heat flux, including the radiative fluxes, as an Essential Ocean Variable (EOV) and Essential Climate Variable (ECV), respectively.  The GOOS and GCOS requirements for surface radiative fluxes (spatial and temporal sampling, accuracies) are summarized here.  Surface radiation sites will continue to be sparse in the future, especially in the ocean; and satellite-derived products developed in concert with in-situ observing system will be important.  To make better progress towards meeting those requirements, we propose the goal of establishing dialog across the different methods of in-situ observing surface radiation and with the remote sensing community.  Objectives of the effort would include sharing knowledge and experience of how to make the observations, documentation of calibration methods, and assessment of the uncertainties to be associated with the different observing methods.  The resulting metadata and quantitative understanding of the different approaches would support improved combination of surface radiation observations across land and sea into homogeneous products at global scale.  At the same time, improved in-situ sampling would help assess and validate climate models and contribute to our understanding of the earth’s energy balance.  We review here the different observing methods now in use on land and at sea and discuss the challenges faced in making the observations.  We also propose future field inter-comparison and standardization of calibration methods to better establish the accuracy and comparability of surface radiation observations on land and at sea.</p>

scholarly journals Design and applications of a neural networks assisted portable liquid surface tensiometer

Chemija ◽  
2021 ◽  
Vol 32 (3-4) ◽  
Author(s):  
Tomas Drevinskas ◽  
Jūratė Balevičiūtė ◽  
Kristina Bimbiraitė-Survilienė ◽  
Gediminas Dūda ◽  
Mantas Stankevičius ◽  
...  
Keyword(s):  
Neural Network ◽  
Surface Tension ◽  
Surfactant Concentration ◽  
Liquid Surface ◽  
Coefficient Of Determination ◽  
Portable Instrument ◽  
The Neural Network ◽  
Calibration Methods ◽  
Retraction Force

In this paper, a portable instrument for surface tension measurements, characterization and applications is described. The instrumentation is operated wirelessly, and samples can be measured in situ. The instrument has changeable different size probes; therefore, it is possible to measure samples from 1 ml up to 10 ml. The response of the measured retraction force and the concentrations of measured surfactant is complex. Therefore, two calibration methods were proposed: (i) the conditional calibration using polynomial and logarithmic fitting and (ii) the neural network trained model prediction of the surfactant concentration in samples. Calibrating the instrument, the neural network trained model showed a superior coefficient of determination (0.999), comparing it to the conditional calibration using polynomial (0.992) and logarithmic (0.991) fit equations.

scholarly journals Improving In-Situ Estimation of Soil Profile Properties Using a Multi-Sensor Probe

Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1011 ◽  
Author(s):  
Xiaoshuai Pei ◽  
Kenneth Sudduth ◽  
Kristen Veum ◽  
Minzan Li
Keyword(s):  
Soil Properties ◽  
Soil Profile ◽  
Near Infrared ◽  
Diffuse Reflectance Spectroscopy ◽  
Chemical Properties ◽  
Estimation Accuracy ◽  
Soil Core ◽  
Least Squares Regression ◽  
Calibration Methods

Optical diffuse reflectance spectroscopy (DRS) has been used for estimating soil physical and chemical properties in the laboratory. In-situ DRS measurements offer the potential for rapid, reliable, non-destructive, and low cost measurement of soil properties in the field. In this study, conducted on two central Missouri fields in 2016, a commercial soil profile instrument, the Veris P4000, acquired visible and near-infrared (VNIR) spectra (343–2222 nm), apparent electrical conductivity (ECa), cone index (CI) penetrometer readings, and depth data, simultaneously to a 1 m depth using a vertical probe. Simultaneously, soil core samples were obtained and soil properties were measured in the laboratory. Soil properties were estimated using VNIR spectra alone and in combination with depth, ECa, and CI (DECS). Estimated soil properties included soil organic carbon (SOC), total nitrogen (TN), moisture, soil texture (clay, silt, and sand), cation exchange capacity (CEC), calcium (Ca), magnesium (Mg), potassium (K), and pH. Multiple preprocessing techniques and calibration methods were applied to the spectral data and evaluated. Calibration methods included partial least squares regression (PLSR), neural networks, regression trees, and random forests. For most soil properties, the best model performance was obtained with the combination of preprocessing with a Gaussian smoothing filter and analysis by PLSR. In addition, DECS improved estimation of silt, sand, CEC, Ca, and Mg over VNIR spectra alone; however, the improvement was more than 5% only for Ca. Finally, differences in estimation accuracy were observed between the two fields despite them having similar soils, with one field demonstrating better results for all soil properties except silt. Overall, this study demonstrates the potential for in-situ estimation of profile soil properties using a multi-sensor approach, and provides suggestions regarding the best combination of sensors, preprocessing, and modeling techniques for in-situ estimation of profile soil properties.

An Investigation Into Acoustic Dipole Source Calibration Methods for Turbomachinery Sound Radiation in Reverberant Fields

2016 ◽  
Author(s):  
Michael L. Jonson ◽  
Steven D. Young
Keyword(s):  
Near Field ◽  
Dipole Source ◽  
Acoustic Source ◽  
In Situ Calibration ◽  
Calibration Methods ◽  
Penn State ◽  
Radiated Sound ◽  
Reverberant Field ◽  
Dipole Sources

In-situ calibration methods using a single spherical-shaped transmitting hydrophone (idealized as a monopole acoustic source) have traditionally been used for radiated sound measurements of turbomachinery performed in the Garfield Thomas 1.22-m diameter water tunnel located at The Pennsylvania State University’s Applied Research Laboratory (ARL Penn State). In this reverberant field, the monopole source containing known transmitting characteristics was used to calibrate acoustic sensors that were either near or far from the source. This method typically works well when the type of source is monopole in nature; however, many acoustics sources can be dipole or quadrupole in nature. In this study we investigated the applicability of using dipole sources in a space such as a well-characterized reverberant tank, and we found through a virtual dipole method that the radiation still appears monopole in the reverberant field. The method was extended for the vibration of a panel (a known dipole source) and once again the monopole assumption for the in-situ calibration for a near-field hydrophone and conventional reverberant hydrophones remained consistent.

In situ Pb-Pb isotopic dating of sulfides from hydrothermal deposits: a case study of the Lala Fe-Cu deposit, SW China

2018 ◽  
Vol 54 (5) ◽  
pp. 671-682 ◽  
Author(s):  
Wei Terry Chen ◽  
Mei-Fu Zhou ◽  
Xiaochun Li ◽  
Jian-Feng Gao ◽  
Zhian Bao ◽  
...  
Keyword(s):  
Isotopic Dating ◽  
Sw China ◽  
Hydrothermal Deposits

Infra-AUV project: Metrology for low-frequency sound and vibration

2021 ◽  
Author(s):  
Lars Ceranna ◽  
Thomas Bruns ◽  
Christian Koch ◽  
Dominique Rodrigues ◽  
Stephen Robinson ◽  
...  
Keyword(s):  
Low Frequency ◽  
Monitoring Networks ◽  
Vibration Data ◽  
In Situ Calibration ◽  
Laboratory Calibration ◽  
Calibration Methods ◽  
National Measurement ◽  
Eu Project

<p>Infra-AUV is a new EU project that will establish primary measurements standards for low frequency phenomena across the fields of airborne and underwater acoustics and vibration (seismology). Combining expertise from the national measurement institutes and geophysical monitoring station operators, it will develop both high-precision laboratory-based methods of calibration and methods suitable for field use. Infra-AUV will also address requirements for reference sensors that link laboratory calibration capabilities to field requirements for measurement traceability.</p><p>To establish standards in the three technical areas, a variety of calibration principles will be employed, including extension of existing techniques such as reciprocity and optical interferometry, and development of new methods. There will also be an investigation of the potential for in-situ calibration methods, including use of both artificially generated and naturally occurring stimuli such as microseisms and microbaroms. The influence of calibration uncertainties on the determination of the measurands required by the monitoring networks will also be studied.</p><p>The project was strongly motivated by the CTBTO strategy to drive new metrology capability to underpin IMS data. The intention is to maintain interaction with stakeholders, not only in connection with the IMS, but with the broad range of users of low frequency acoustic and vibration data. </p>

scholarly journals Six-Axis Force Torque Sensor Model-Based In Situ Calibration Method and Its Impact in Floating-Based Robot Dynamic Performance

Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5521
Author(s):  
Francisco Javier Andrade Chavez ◽  
Silvio Traversaro ◽  
Daniele Pucci
Keyword(s):  
Dynamic Performance ◽  
Calibration Method ◽  
Full Description ◽  
Temperature Drift ◽  
Model Based ◽  
Floating Base ◽  
In Situ Calibration ◽  
Calibration Methods ◽  
The Impact

A crucial part of dynamic motions is the interaction with other objects or the environment. Floating base robots have yet to perform these motions repeatably and reliably. Force torque sensors are able to provide the full description of a contact. Despite that, their use beyond a simple threshold logic is not widespread in floating base robots. Force torque sensors might change performance when mounted, which is why in situ calibration methods can improve the performance of robots by ensuring better force torque measurements. The Model-Based in situ calibration method with temperature compensation has shown promising results in improving FT sensor measurements. There are two main goals for this paper. The first is to facilitate the use and understanding of the method by providing guidelines that show their usefulness through experimental results. Then the impact of having better FT measurements with no temperature drift are demonstrated by proving that the offset estimated with this method is still useful days and even a month from the time of estimation. The effect of this is showcased by comparing the sensor response with different offsets simultaneously during real robot experiments. Furthermore, quantitative results of the improvement in dynamic behaviors due to the in situ calibration are shown. Finally, we show how using better FT measurements as feedback in low and high level controllers can impact the performance of floating base robots during dynamic motions. Experiments were performed on the floating base robot iCub.

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