Accuracy of Wind Observations from Open-Ocean Buoys: Correction for Flow Distortion

AbstractThe comparison of equivalent neutral winds obtained from (i) four WHOI buoys in the subtropics and (ii) scatterometer estimates at those locations reveals a root-mean-square (RMS) difference of 0.56–0.76 m s−1. To investigate this RMS difference, different buoy wind error sources were examined. These buoys are particularly well suited to examine two important sources of buoy wind errors because 1) redundant anemometers and a comparison with numerical flow simulations allow us to quantitatively assess flow distortion errors, and 2) 1-min sampling at the buoys allows us to examine the sensitivity of buoy temporal sampling/averaging in the buoy–scatterometer comparisons. The interanemometer difference varies as a function of wind direction relative to the buoy wind vane and is consistent with the effects of flow distortion expected based on numerical flow simulations. Comparison between the anemometers and scatterometer winds supports the interpretation that the interanemometer disagreement, which can be up to 5% of the wind speed, is due to flow distortion. These insights motivate an empirical correction to the individual anemometer records and subsequent comparison with scatterometer estimates show good agreement.

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Tropospheric NO<sub>2</sub> column densities deduced from zenith-sky DOAS measurements in Shanghai, China, and their application to satellite validation

Atmospheric Chemistry and Physics ◽

10.5194/acp-9-3641-2009 ◽

2009 ◽

Vol 9 (11) ◽

pp. 3641-3662 ◽

Cited By ~ 51

Author(s):

D. Chen ◽

B. Zhou ◽

S. Beirle ◽

L. M. Chen ◽

T. Wagner

Keyword(s):

Satellite Data ◽

Urban Site ◽

Optical Absorption Spectroscopy ◽

Vertical Column ◽

Error Sources ◽

Satellite Validation ◽

Tropospheric No2 ◽

Realistic Information ◽

Good Agreement

Abstract. Zenith-sky scattered sunlight observations using differential optical absorption spectroscopy (DOAS) technique were carried out in Shanghai, China (31.3° N, 121.5° E) since December 2006. At this polluted urban site, the measurements provided NO2 total columns in the daytime. Here, we present a new method to extract time series of tropospheric vertical column densities (VCDs) of NO2 from these observations. The derived tropospheric NO2 VCDs are important quantities for the estimation of emissions and for the validation of satellite observations. Our method makes use of assumptions on the relative NO2 height profiles and the diurnal variation of stratospheric NO2 VCDs. The main error sources arise from the uncertainties in the estimated stratospheric slant column densities (SCDs) and the determination of tropospheric NO2 air mass factor (AMF). For a polluted site like Shanghai, the accuracy of our method is conservatively estimated to be <25% for solar zenith angle (SZA) lower than 70°. From simultaneously performed long-path DOAS measurements, the NO2 surface concentrations at the same site were observed and the corresponding tropospheric NO2 VCDs were estimated using the assumed seasonal NO2 profiles in the planetary boundary layer (PBL). By making a comparison between the tropospheric NO2 VCDs from zenith-sky and long-path DOAS measurements, it is found that the former provides more realistic information about total tropospheric pollution than the latter, so it's more suitable for satellite data validation. A comparison between the tropospheric NO2 VCDs from ground-based zenith-sky measurements and SCIAMACHY was also made. Satellite validation for a strongly polluted area is highly needed, but exhibits also a great challenge. Our comparison shows good agreement, considering in particular the different spatial resolutions between the two measurements. Remaining systematic deviations are most probably related to the uncertainties of satellite data caused by the assumptions on aerosol properties as well as the layer heights of aerosols and NO2.

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Expressions for the effective diffusivity in materials with interphase boundaries

MRS Proceedings ◽

10.1557/proc-819-n3.14 ◽

2004 ◽

Vol 819 ◽

Author(s):

Irina V. Belova ◽

Graeme E. Murch

Keyword(s):

Polycrystalline Material ◽

Effective Diffusivity ◽

Poor Agreement ◽

Two Phase ◽

Interphase Boundaries ◽

Long Time ◽

Simulation Results ◽

The Individual ◽

Individual Grains ◽

Good Agreement

AbstractWe address the problem of calculating the long-time-limit effective diffusivity in stable two- phase polycrystalline material. A phenomenological model is used where the high diffusivity interphase boundaries are treated as connected “coatings” of the individual grains. Derivation of expressions for the effective diffusivity with segregation is made along Maxwell lines. Monte Carlo simulation using lattice-based random walks is used to test the validity of the expressions. It is shown that for the case analysed the derived expressions for the effective diffusivity are in very good agreement with simulation results. The equivalent of the Hart equation is also derived. It is shown to be in poor agreement with simulation results.

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Error Analysis of a Mobile Terrestrial LiDAR System

GEOMATICA ◽

10.5623/cig2014-303 ◽

2014 ◽

Vol 68 (3) ◽

pp. 183-194 ◽

Cited By ~ 3

Author(s):

M. Leslar ◽

B. Hu ◽

J.G. Wang

Keyword(s):

Point Cloud ◽

Point Clouds ◽

Sensitivity Study ◽

Error Sources ◽

Terrestrial Lidar ◽

Lever Arm ◽

Ideal Situation ◽

Individual Variables ◽

The Individual ◽

Source Of Error

The understanding of the effects of error on Mobile Terrestrial LiDAR (MTL) point clouds has not increased with their popularity. In this study, comprehensive error analyses based on error propagation theory and global sensitivity study were carried out to quantitatively describe the effects of various error sources in a MTL system on the point cloud. Two scenarios were envisioned; the first using the uncertainties for measurement and calibration variables that are normally expected for MTL systems as they exist today, and the second using an ideal situation where measurement and calibration values have been well adjusted. It was found that the highest proportion of error in the point cloud can be attributed to the boresight and lever arm parameters for MTL systems calibrated using non-rigours methods. In particular, under a loosely controlled error condition, the LiDAR to INS Z lever arm and the LiDAR to INS roll angle contributed more error in the output point cloud than any other parameter, including the INS position. Under tightly controlled error conditions, the INS position became the dominant source of error in the point cloud. In addition, conditional variance analysis has shown that the majority of the error in a point cloud can be attributed to the individual variables. Errors caused by the interactions between the diverse variables are minimal and can be regarded as insignificant.

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ANALYSIS OF THE MAIN DETERMINANTS OF THE RUSSIAN CONSUMERS’ CURRENT MOOD

Vestnik Universiteta ◽

10.26425/1816-4277-2020-2-172-178 ◽

2020 ◽

pp. 172-178

Author(s):

I. Yu. Aleksandrova

Keyword(s):

Economic Status ◽

Implicit Theory ◽

Semantic Structure ◽

Semantic Field ◽

Socio Economic Status ◽

Current Mood ◽

Main Determinants ◽

The Individual ◽

Real Purchasing ◽

Subsequent Comparison

The socio-psychological phenomenon “consumer mood”, which is interpreted as an emotional and evaluative summary of the subjective understanding of the individual of various information elements that form the semantic structure of his implicit theory of consumption, has been investigated. A hypothesis has been put forward that the formation of the semantic field of the implicit theory of consumption of an individual is based on two system-forming factors: 1) the real purchasing power of the consumer, 2) the dynamics of his socio-economic status. In the event that both factors have negative actual indicators, the mood of consumer will be characterized by a negative emotional tone and high stability over time. The proposed hypothesis is confirmed by the revealing and analysis of the main determinants of the current mood of Russian consumers, and their subsequent comparison with the consumer sentiment index, identificated empirically.

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A Radiomics nomogram for preoperative predicting recurrence of low grade gliomas based on multiparametric MRI

10.21203/rs.3.rs-345383/v1 ◽

2021 ◽

Author(s):

Zhenhua Wang ◽

Xinlan Xiao ◽

Zhaotao Zhang ◽

Keng He ◽

Peipei Pang ◽

...

Keyword(s):

Multivariate Logistic Regression Analysis ◽

Low Grade ◽

Training Set ◽

Decision Curve Analysis ◽

Logistic Analysis ◽

Contrast Enhanced ◽

Fluid Attenuated Inversion Recovery ◽

Validation Set ◽

The Individual ◽

Good Agreement

Abstract Objective To develop a radiomics nomogram to predict the recurrence of Low grade glioma(LGG) after their first surgery; Methods A retrospective analysis of pathological, clinical and Magnetic resonance image(MRI) of LGG patients who underwent surgery and had a recurrence between 2017 and 2020 in our hospital was performed. After a rigorous selection,64 patients were eligible and enrolled in the study(22 cases were with recurrent gliomas),which was randomly assigned in a 7:3 ratio to either the training set and validation set; T1WI,T2WI fluid-attenuated-inversion-recovery(T2WI-FLAIR) and contrast-enhanced T1-weighted(T1CE) sequences, 396 radiomics features were extracted from each image sequence, minimum-redundancy maximum-relevancy(mRMR) alone or combining with univariate logistic analysis were used for features screening, the screened features were performed by multivariate logistic regression analysis and developed a predictive model both in training set and validation set; Receiver operating characteristic(ROC) curve, calibration curve, and decision curve analysis(DCA) were used to assess the performance of each model. Results The radiomics nomogram derived from three MRI sequence yielded an ideal performance than the individual ones, the AUC in the training set and validation set were 0.966 and 0.93 respectively, 95% confidence interval(95%CI) were 0.949-0.99 and 0.905-0.973 respectively; the calibration curves indicated good agreement between the predictive and the actual probability. The DCA demonstrated that a combination of three sequences had more favorable clinical predictive value than single sequence imaging. Conclusion Our multiparametric radiomics nomogram could be an efficient and accurate tool for predicting the recurrence of LGG after its first resection.

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Optical Interference Filters By Sol-Gel Processing

MRS Proceedings ◽

10.1557/proc-180-383 ◽

1990 ◽

Vol 180 ◽

Cited By ~ 2

Author(s):

J.L. Keddie ◽

E.P. Giannelis

Keyword(s):

Refractive Index ◽

Rutherford Backscattering Spectrometry ◽

Incident Light ◽

Sol Gel ◽

Theoretical Modeling ◽

Optical Interference ◽

Interference Filters ◽

The Individual ◽

Gel Processing ◽

Good Agreement

ABSTRACTOptical interference filters have been synthesized by sol-gel. The selected filter is a multilayer of alternating TiO2 and SiO2 films. In transmission, the filter edge depends on the angle of incident light, which can be tailored through control of thickness and refractive index of the individual films. Theoretical modeling of the filter with film thicknesses obtained by Rutherford backscattering spectrometry is in good agreement with the experimental optical response.

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Optimization of Fenton Technology for Recalcitrant Compounds and Bacteria Inactivation

Catalysts ◽

10.3390/catal10121483 ◽

2020 ◽

Vol 10 (12) ◽

pp. 1483

Author(s):

Pablo Salgado ◽

José Luis Frontela ◽

Gladys Vidal

Keyword(s):

Regression Coefficient ◽

Interactive Effects ◽

Molar Ratio ◽

Main Process ◽

Optimum Conditions ◽

Box Behnken Design ◽

E Coli ◽

Bacteria Inactivation ◽

The Individual ◽

Good Agreement

In this work, the Fenton technology was applied to decolorize methylene blue (MB) and to inactivate Escherichia coli K12, used as recalcitrant compound and bacteria models respectively, in order to provide an approach into single and combinative effects of the main process variables influencing the Fenton technology. First, Box–Behnken design (BBD) was applied to evaluate and optimize the individual and interactive effects of three process parameters, namely Fe2+ concentration (6.0 × 10−4, 8.0 × 10−4 and 1.0 × 10−3 mol/L), molar ratio between H2O2 and Fe2+ (1:1, 2:1 and 3:1) and pH (3.0, 4.0 and 5.0) for Fenton technology. The responses studied in these models were the degree of MB decolorization (D%MB), rate constant of MB decolorization (kappMB) and E. coli K12 inactivation in uLog units (IuLogEC). According to the results of analysis of variances all of the proposed models were adequate with a high regression coefficient (R2 from 0.9911 to 0.9994). BBD results suggest that [H2O2]/[Fe2+] values had a significant effect only on D%MB response, [Fe2+] had a significant effect on all the responses, whereas pH had a significant effect on D%MB and IuLogEC. The optimum conditions obtained from response surface methodology for D%MB ([H2O2]/[Fe2+] = 2.9, [Fe2+] = 1.0 × 10−3 mol/L and pH = 3.2), kappMB ([H2O2]/[Fe2+] = 1.7, [Fe2+] = 1.0 × 10−3 mol/L and PH = 3.7) and IuLogEC ([H2O2]/[Fe2+] = 2.9, [Fe2+] = 7.6 × 10−4 mol/L and pH= 3.2) were in good agreement with the values predicted by the model.

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Ligand Redistribution Equilibria in Aqueous Fluoroberyllate Solutions

Zeitschrift für Naturforschung B ◽

10.1515/znb-1998-1110 ◽

1998 ◽

Vol 53 (11) ◽

pp. 1294-1300 ◽

Cited By ~ 11

Author(s):

Michael Schmidt ◽

Hubert Schmidbaur

Keyword(s):

Experimental Data ◽

Ligand Exchange ◽

Room Temperature ◽

Chemical Shifts ◽

Equilibrium Constants ◽

Individual Species ◽

Ph Values ◽

Exchange Processes ◽

The Individual ◽

Good Agreement

The composition of aqueous fluoroberyllate solutions has been studied by 9Be and 19F NMR spectroscopy for various ratios of the beryllium and fluorine concentrations, and at different pH values. The equilibrium constants have been determined for the ligand exchange processes, which involve the species [Be(OH2)4]2+, [BeF(OH2)3]+, [BeF2(OH2)2], [BeF3(OH2)]- , and [BeF4]2-. These equilibria are shifted towards [BeF4]2- at high pH. No polynuclear fluoroberyllates have been detected. The fluoride exchange between the individual species is slow on the NMR time scale at room temperature, and separate sharp signals with the expected multiplicity are therefore recorded. Calculated 9Be chemical shifts are in good agreement with experimental data.

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Traffic Flow on Gradient Highway and its Stability

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.97-98.877 ◽

2011 ◽

Vol 97-98 ◽

pp. 877-882 ◽

Cited By ~ 1

Author(s):

Wen Xing Zhu ◽

Rui Ling Yu ◽

Zhi Ping Jia

Keyword(s):

Traffic Flow ◽

Flow Model ◽

Linear Stability Theory ◽

Stability Conditions ◽

Traffic Flow Model ◽

Flow Simulations ◽

Numerical Result ◽

The Stability ◽

Real Traffic ◽

Good Agreement

In this paper we investigated the stability of the traffic flow on a single lane gradient (uphill/downhill) highway. The linear stability theory was used to analyze the model and get the stability conditions. The theoretical result shows that the slope of the gradient has an influence on the stability of traffic flow. Simulations are carried out to check the slope effect of the traffic flow model. Numerical result is in good agreement with the real traffic situations.

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Insight into neutron focusing: the out-of-focus condition

Journal of Applied Crystallography ◽

10.1107/s0021889813018633 ◽

2013 ◽

Vol 46 (5) ◽

pp. 1361-1371 ◽

Cited By ~ 1

Author(s):

B. Hammouda ◽

D. F. R. Mildner ◽

A. Brûlet ◽

S. Desert

Keyword(s):

Standard Deviation ◽

Neutron Scattering ◽

Small Angle ◽

Small Angle Neutron Scattering ◽

Neutron Wavelength ◽

Focus Condition ◽

The Mean ◽

The Individual ◽

Multiple Holes ◽

Good Agreement

Neutron focusing leads to significant gains in flux-on-sample in small-angle neutron scattering and very small angle neutron scattering instruments. Understanding the out-of-focus condition is necessary for less than optimal conditions such as for short instruments and low neutron wavelengths. Neutron focusing is investigated using a three-pronged approach. The three methods are analytical calculations, resolution measurements and computer simulations. A source aperture containing a single small-size hole and a sample aperture containing multiple holes are used to produce multiple spots on the high-resolution neutron detector. Lens focusing elongates off-axis spots in the radial direction. The standard deviation for the size of each spot is estimated using these three approaches. Varying parameters include the neutron wavelength, the number of focusing lenses and the location of holes on the sample aperture. Enough agreement for the standard deviation of the individual neutron beams was found between the calculations and the measurements to give confidence in this approach. Good agreement was found between the standard deviations obtained from calculations and simulations as well. Excellent agreement was found for the mean location of these individual spots.

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