scholarly journals In-situ interactive modeling using a single-point laser rangefinder coupled with a new hybrid orientation tracker

2013 ◽  
Author(s):  
Christel Leonet ◽  
Gilles Simon ◽  
Marie-Odile Berger
Keyword(s):  
Single Point ◽  
Laser Rangefinder ◽  
Interactive Modeling

In-situ variable-temperature single-point NMR imaging study of coals

Fuel ◽  
2000 ◽  
Vol 79 (3-4) ◽  
pp. 405-416 ◽  
Author(s):  
K Saito ◽  
I Komaki ◽  
K.-I Hasegawa ◽  
H Tsuno
Keyword(s):  
Variable Temperature ◽  
Single Point ◽  
Imaging Study ◽  
Nmr Imaging

scholarly journals Multi-source SO<sub>2</sub> emissions retrievals and consistency of satellite and surface measurements with reported emissions

2017 ◽  
Author(s):  
Vitali Fioletov ◽  
Chris A. McLinden ◽  
Shailesh K. Kharol ◽  
Nickolay A. Krotkov ◽  
Can Li ◽  
...  
Keyword(s):  
Point Source ◽  
Single Point ◽  
Control Measures ◽  
Ozone Monitoring Instrument ◽  
So2 Emissions ◽  
Vertical Column ◽  
Wind Speeds ◽  
Surface Measurements ◽  
Best Fit

Abstract. Reported sulfur dioxide (SO2) emissions from U.S. and Canadian sources have declined dramatically since the 1990s as a result of emissions control measures. Observations from the Ozone Monitoring Instrument (OMI) on NASA's Aura satellite and ground-based in-situ measurements are examined to verify whether the observed changes from SO2 abundance measurements are quantitatively consistent with the reported changes in emissions. To make this connection, a new method to link SO2 emissions and satellite SO2 measurements was developed. The method is based on fitting satellite SO2 vertical column densities (VCDs) to a set of functions of OMI pixel coordinates and wind speeds, where each function represents a statistical model of a plume from a single point source. The concept is first demonstrated using sources in North America, and then applied to Europe. The correlation coefficient between OMI-measured VCDs (with a local bias removed) and SO2 VCDs derived here using reported emissions for 1° by 1° gridded data is 0.91 and the best-fit line has a slope near unity, confirming a very good agreement between observed SO2 VCDs and reported emissions. Having demonstrated their consistency, seasonal and annual mean SO2 VCD distributions are calculated, based on reported point-source emissions for the period 1980–2015, as would have been seen by OMI. This consistency is further substantiated as the emissions-derived VCDs also show a high correlation with annual mean SO2 surface concentrations at 50 regional monitoring stations.

scholarly journals An evaluation of the performance of Sea-Bird Scientific's SeaFET™ autonomous pH sensor: considerations for the broader oceanographic community

Ocean Science ◽  
2018 ◽  
Vol 14 (4) ◽  
pp. 751-768 ◽  
Author(s):  
Cale A. Miller ◽  
Katie Pocock ◽  
Wiley Evans ◽  
Amanda L. Kelley
Keyword(s):  
Spectral Analysis ◽  
Time Series Data ◽  
Single Point ◽  
Ph Sensor ◽  
Calibration Method ◽  
Series Data ◽  
South Central ◽  
Autonomous Sensor ◽  
Robust Measurements

Abstract. The commercially available Sea-Bird SeaFET™ provides an accessible way for a broad community of researchers to study ocean acidification and obtain robust measurements of seawater pH via the use of an in situ autonomous sensor. There are pitfalls, however, that have been detailed in previous best practices for sensor care, deployment, and data handling. Here, we took advantage of two distinctly different coastal settings to evaluate the Sea-Bird SeaFET™ and examine the multitude of scenarios in which problems may arise confounding the accuracy of measured pH. High-resolution temporal measurements of pH were obtained during 3- to 5-month field deployments in three separate locations (two in south-central Alaska, USA, and one in British Columbia, Canada) spanning a broad range of nearshore temperature and salinity conditions. Both the internal and external electrodes onboard the SeaFET™ were evaluated against robust benchtop measurements for accuracy using the factory calibration, an in situ single-point calibration, or an in situ multi-point calibration. In addition, two sensors deployed in parallel in Kasitsna Bay, Alaska, USA, were compared for inter-sensor variability in order to quantify other factors contributing to the sensor's intrinsic inaccuracies. Based on our results, the multi-point calibration method provided the highest accuracy (< 0.025 difference in pH) of pH when compared against benchtop measurements. Spectral analysis of time series data showed that during spring in Alaskan waters, a range of tidal frequencies dominated pH variability, while seasonal oceanographic conditions were the dominant driver in Canadian waters. Further, it is suggested that spectral analysis performed on initial deployments may be able to act as an a posteriori method to better identify appropriate calibration regimes. Based on this evaluation, we provide a comprehensive assessment of the potential sources of uncertainty associated with accuracy and precision of the SeaFET™ electrodes.

scholarly journals Multi-source SO<sub>2</sub> emission retrievals and consistency of satellite and surface measurements with reported emissions

2017 ◽  
Vol 17 (20) ◽  
pp. 12597-12616 ◽  
Author(s):  
Vitali Fioletov ◽  
Chris A. McLinden ◽  
Shailesh K. Kharol ◽  
Nickolay A. Krotkov ◽  
Can Li ◽  
...  
Keyword(s):  
Point Source ◽  
Single Point ◽  
Control Measures ◽  
Ozone Monitoring Instrument ◽  
So2 Emissions ◽  
Vertical Column ◽  
Wind Speeds ◽  
Surface Measurements ◽  
Best Fit

Abstract. Reported sulfur dioxide (SO2) emissions from US and Canadian sources have declined dramatically since the 1990s as a result of emission control measures. Observations from the Ozone Monitoring Instrument (OMI) on NASA's Aura satellite and ground-based in situ measurements are examined to verify whether the observed changes from SO2 abundance measurements are quantitatively consistent with the reported changes in emissions. To make this connection, a new method to link SO2 emissions and satellite SO2 measurements was developed. The method is based on fitting satellite SO2 vertical column densities (VCDs) to a set of functions of OMI pixel coordinates and wind speeds, where each function represents a statistical model of a plume from a single point source. The concept is first demonstrated using sources in North America and then applied to Europe. The correlation coefficient between OMI-measured VCDs (with a local bias removed) and SO2 VCDs derived here using reported emissions for 1° by 1° gridded data is 0.91 and the best-fit line has a slope near unity, confirming a very good agreement between observed SO2 VCDs and reported emissions. Having demonstrated their consistency, seasonal and annual mean SO2 VCD distributions are calculated, based on reported point-source emissions for the period 1980–2015, as would have been seen by OMI. This consistency is further substantiated as the emission-derived VCDs also show a high correlation with annual mean SO2 surface concentrations at 50 regional monitoring stations.

In Situ Models, Physico-Chemical Aspects

1994 ◽  
Vol 8 (2) ◽  
pp. 125-133 ◽  
Author(s):  
J.M. Ten Cate
Keyword(s):  
Single Point ◽  
Limiting Factor ◽  
Model Parameters ◽  
Laboratory Findings ◽  
Physiological Processes ◽  
Physico Chemical ◽  
Crystallite Surface ◽  
Mineral Loss

In situ (intra-oral) caries models are used for two purposes. First, they provide information about oral physiological processes. Such information helps to detail our knowledge of the oral ecosystem and to verify conclusions from in vitro experiments. Second, in situ models are utilized to test preventive agents in the phase between laboratory testing and clinical trials. Most investigations involving enamel inserts have been aimed at testing new dentifrices. The experimental designs of such studies usually do not allow one to draw conclusions on physico-chemical processes, e.g., because of single point measurements. Studies of model parameters (lesion type, lesion severity, and de/remineralization in time) constitute only a minority of the research reports. The most striking observation obtained with in situ models has been the significant differences in de/remineralization observed among individuals and, more importantly, within one individual during different time periods and between different sites in the same mouth (for review, see ten Cate et al., 1992). Regardless of this, some general findings can be inferred: During in situ demineralization, up to 62 vol%μm/day may be removed from enamel. For dentin specimens, this value may be as high as 89 vol%μm/day. For remineralization, during fluoride dentifrice treatment, a median deposition rate of 0.7%/day (for lesions with integrated mineral loss values between 2000 and 4000 vol%μm) is found. The rate of deposition seems to be correlated with the extent of the pre-formedlesion. This suggests that the number of sites (crystallite surface) available for calcium phosphate precipitation is an important parameter. However, the rate at which mineral ions are supplied (by saliva) could also be a limiting factor, as is shown in a theoretical analysis of mass-balance of enamel constituents. The few studies that have monitored caries development in time reveal that mineral loss (and also lesion progression in depth) from enamel in situ is linear in time. This is in contrast to results from laboratory findings.

scholarly journals Numerical Analysis for Predicting the Performance of Wave Observation Buoy: Dynamic Analysis under Regular Wave

2021 ◽  
Vol 8 (3) ◽  
pp. 127-139
Author(s):  
Insik Chun ◽  
In-Ki Min ◽  
Yongchim Min ◽  
Byungcheol Oh ◽  
Jaeseol Shim
Keyword(s):  
Single Point ◽  
Experimental Results ◽  
Mooring Line ◽  
Regular Wave ◽  
Experimental Conditions ◽  
Wave Observation ◽  
Exciting Forces ◽  
Set Up ◽  
Heave Motion

The prediction of the performance of a wave observation buoy is very important to acquire both in-situ security and good observation quality. In the present study, a numerical method was set up to analyze the dynamic interaction of a spherical buoy with its single point mooring line subject to regular wave conditions. The method was applied to the condition of an existing hydraulic experiment, producing results that are well compatible with experimental results within the limited accuracy of the available data. It was argued that some discrepancies between the numerical and experimental results might be due to the uncertainties of the wave exciting forces acting on the buoy and the experimental conditions of mooring line. The method was finally applied to demonstrate two practical issues related to in-situ wave height measurements; the effect of buoy size on resulting heave motion and the aspect of the numerical integration of heave acceleration to get wave profile.

scholarly journals In situ measurements of molecular iodine in the marine boundary layer: the link to macroalgae and the implications for O<sub>3</sub>, IO, OIO and NO<sub>x</sub>

2010 ◽  
Vol 10 (1) ◽  
pp. 361-390
Author(s):  
R.-J. Huang ◽  
K. Seitz ◽  
J. Buxmann ◽  
D. Poehler ◽  
K. E. Hornsby ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Marine Boundary Layer ◽  
Single Point ◽  
Molecular Iodine ◽  
In Situ Measurements ◽  
Gas Chromatography Mass Spectrometry ◽  
Optical Absorption Spectroscopy ◽  
Mixing Ratios ◽  
Concentration Levels

Abstract. "Single-point" in situ measurements of molecular iodine (I2) were carried out in the coastal marine boundary layer (MBL) using diffusion denuders in combination with a gas chromatography-mass spectrometry (GC-MS) method. Comparison measurements were taken at Mace Head and Mweenish Bay, on the West Coast of Ireland. The observed mixing ratios of I2 at Mweenish Bay are much higher than that at Mace Head, indicating the emissions of I2 are correlated with the local algal biomass density and algae species. The concentration levels of I2 were found to correlate inversely with tidal height and correlate positively with the concentration levels of O3 in the surrounding air. However, the released I2 can also lead to O3 destruction via the reaction of O3 with iodine atoms that are formed by the photolysis of I2 during the day and via the reaction of I2 with NOx at night. IO and OIO were measured by long-path differential optical absorption spectroscopy (LP-DOAS). The results show that the concentrations of both daytime and nighttime IO are correlated with the mixing ratios of I2. OIO was observed not only during the day but also, for the first time at both Mace Head and Mweenish Bay, at night. In addition, I2 was measured simultaneously by the LP-DOAS technique and compared with the "single-point" in situ measurement. The results suggest that the local algae sources dominate the inorganic iodine chemistry at Mace Head and Mweenish Bay.

Triple-point magnetic flux rope analysis for the 2020 April 19 CME observed in situ by Solar Orbiter, Bepi Colombo, and WIND

2021 ◽  
Author(s):  
Andreas J. Weiss ◽  
Christian Möstl ◽  
Emma Davies ◽  
Matthew J. Owens ◽  
Tanja Amerstorfer ◽  
...  
Keyword(s):  
Triple Point ◽  
Single Point ◽  
Flux Rope ◽  
Radial Distance ◽  
Field Measurements ◽  
Model Parameters ◽  
Magnetic Flux Rope ◽  
Point Analysis ◽  
Point Combination

&lt;p&gt;We present initial results for a triple-point analysis for the in situ magnetic field measurements of a CME observed at three independent locations. On the 19th of April 2020, Solar Orbiter observed a CME in situ at a radial distance of around&amp;#160;0.8 au. This CME was subsequently also detected by the Wind and Bepi Colombo satellites closer to Earth. This triple in situ measurement of a CME provides us the unique opportunity to test the consistency of the measurements with our own 3D Coronal Rope Ejection (3DCORE) model. A triple measurement allows for up to seven different data combinations to be analyzed (three single-point, three dual-point, and one single triple-point combination) which gives us&amp;#160;information on how our analysis pipeline responds to multi-point measurements and how the results change with measurements at differing radial and longitudinal distances. The goal of this study is to test whether all three in situ measurements can still be described by a slightly bent flux rope geometry and how adding additional&amp;#160;measurements can improve the accuracy of inferred model parameters.&lt;/p&gt;

In Situ Measurement and Compensation Turning Technique of Deep MgF2 Conformal Dome

2014 ◽  
Vol 1027 ◽  
pp. 136-139
Author(s):  
Deng Chao Zhu ◽  
Yi Fan Dai ◽  
Chao Liang Guan ◽  
Gui Lin Wang ◽  
Gui Peng Tie
Keyword(s):  
Measurement System ◽  
Single Point ◽  
Diamond Turning ◽  
Machining Process ◽  
Shape Error ◽  
Turning Process ◽  
Compensation Process ◽  
Surface Test ◽  
Machining Characteristics

The adoption of conformal optics system can evidently improve the synthetical performance of infrared missiles. Hot-pressing poly-crystal magnesium fluoride (MgF2) is an ideal material for conformal optics dome. But many problems about machining and surface test of deep aspheric surface have not been solved at present, and there is not much research about the machining characteristics of MgF2 material. In this paper, in-situ measurement system is designed, so positional errors that introduced by repeating installation can be avoided. Then, machining process of MgF2 material by single point diamond turning is studied, and optimized diamond turning process is proposed by experiments in order to obtain low surface roughness. Furthermore, surface accuracy is tested by on-machine measurement system. Based on the result, error compensation process of conformal dome is carried out. Finally, the shape error of the dome is less than 0.8μm PV.

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