scholarly journals Characterization on Polyester Fibrous Panels and Their Homogeneity Assessment

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2098 ◽  
Author(s):  
Tao Yang ◽  
Ferina Saati ◽  
Jean-Philippe Groby ◽  
Xiaoman Xiong ◽  
Michal Petrů ◽  
...  
Keyword(s):  
Thermal Characteristic ◽  
Acoustic Parameters ◽  
Reconstruction Procedure ◽  
Direct Measurements ◽  
Homogeneity Assessment ◽  
The Mean ◽  
Panel Thickness ◽  
Relative Differences ◽  
Good Agreement ◽  
Do So

Nowadays, fibrous polyester materials are becoming one of the most important alternatives for controlling reverberation time by absorbing unwanted sound energy in the automobile and construction fields. Thus, it is worthy and meaningful to characterize their acoustic behavior. To do so, non-acoustic parameters, such as tortuosity, viscous and thermal characteristic lengths and thermal permeability, must be determined. Representative panels of polyester fibrous material manufactured by perpendicular laying technology are thus tested via the Bayesian reconstruction procedure. The estimated porosity and airflow resistivity are found in good agreement with those tested via direct measurements. In addition, the homogeneity of polyester fibrous panels was characterized by investigating the mean relative differences of inferred non-acoustic parameters from the direct and reverse orientation measurements. Some parameters, such as tortuosity, porosity and airflow resistivity, exhibit very low relative differences. It is found that most of the panels can be assumed homogeneous along with the panel thickness, the slight inhomogeneity mostly affecting the thermal characteristic length.

scholarly journals The Residual GEM Technique and Its Application to the Southwestern Japan/East Sea

2004 ◽  
Vol 21 (12) ◽  
pp. 1895-1909 ◽  
Author(s):  
D. A. Mitchell ◽  
M. Wimbush ◽  
D. R. Watts ◽  
W. J. Teague
Keyword(s):  
Pressure Gauge ◽  
East Sea ◽  
Ocean Data Assimilation ◽  
Direct Measurements ◽  
Integral Quantity ◽  
The Mean ◽  
Ocean Measurements ◽  
Seasonal Signal ◽  
Gravest Empirical Mode ◽  
Good Agreement

Abstract The standard gravest empirical mode (GEM) technique for utilizing hydrography in concert with integral ocean measurements performs poorly in the southwestern Japan/East Sea (JES) because of a spatially variable seasonal signal and a shallow thermocline. This paper presents a new method that combines the U.S. Navy's Modular Ocean Data Assimilation System (MODAS) static climatology (which implicitly contains the mean seasonal signal) with historical hydrography to construct a “residual GEM” from which profiles of such parameters as temperature (T) and specific volume anomaly (δ) can be estimated from measurements of an integral quantity such as geopotential height or acoustic echo time (τ). This is called the residual GEM technique. In a further refinement, sea surface temperature (SST) measurements are included in the profile determinations. In the southwestern JES, profiles determined by the standard GEM technique capture 70% of the T variance and 64% of the δ variance, while the residual GEM technique using SST captures 89% of the T variance and 84% of the δ variance. The residual GEM technique was applied to optimally interpolated τ measurements from a two-dimensional array of pressure-gauge-equipped inverted echo sounders moored from June 1999 to July 2001 in the southwestern JES, resulting in daily 3D estimated fields of T and δ throughout the region. These estimates are compared with those from direct measurements and good agreement is found between them.

scholarly journals Validation of ACE-FTS version 3.5 NO<sub><i>y</i></sub> species profiles using correlative satellite measurements

2016 ◽  
Vol 9 (12) ◽  
pp. 5781-5810 ◽  
Author(s):  
Patrick E. Sheese ◽  
Kaley A. Walker ◽  
Chris D. Boone ◽  
Chris A. McLinden ◽  
Peter F. Bernath ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Local Times ◽  
Satellite Measurements ◽  
The Mean ◽  
Mean Differences ◽  
Relative Differences ◽  
Chemistry Experiment ◽  
Recent Version ◽  
Better Than ◽  
Good Agreement

Abstract. The ACE-FTS (Atmospheric Chemistry Experiment – Fourier Transform Spectrometer) instrument on the Canadian SCISAT satellite, which has been in operation for over 12 years, has the capability of deriving stratospheric profiles of many of the NOy (N + NO + NO2+ NO3+ 2  ×  N2O5+ HNO3+ HNO4+ ClONO2+ BrONO2) species. Version 2.2 of ACE-FTS NO, NO2, HNO3, N2O5, and ClONO2 has previously been validated, and this study compares the most recent version (v3.5) of these five ACE-FTS products to spatially and temporally coincident measurements from other satellite instruments – GOMOS, HALOE, MAESTRO, MIPAS, MLS, OSIRIS, POAM III, SAGE III, SCIAMACHY, SMILES, and SMR. For each ACE-FTS measurement, a photochemical box model was used to simulate the diurnal variations of the NOy species and the ACE-FTS measurements were scaled to the local times of the coincident measurements. The comparisons for all five species show good agreement with correlative satellite measurements. For NO in the altitude range of 25–50 km, ACE-FTS typically agrees with correlative data to within −10 %. Instrument-averaged mean relative differences are approximately −10 % at 30–40 km for NO2, within ±7 % at 8–30 km for HNO3, better than −7 % at 21–34 km for local morning N2O5, and better than −8 % at 21–34 km for ClONO2. Where possible, the variations in the mean differences due to changes in the comparison local time and latitude are also discussed.

scholarly journals Validation of ACE-FTS version 3.5 NO<sub>y</sub> species profiles using correlative satellite measurements

2016 ◽  
Author(s):  
Patrick E. Sheese ◽  
Kaley A. Walker ◽  
Chris D. Boone ◽  
Chris A. McLinden ◽  
Peter F. Bernath ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Local Times ◽  
Satellite Measurements ◽  
The Mean ◽  
Mean Differences ◽  
Relative Differences ◽  
Chemistry Experiment ◽  
Recent Version ◽  
Better Than ◽  
Good Agreement

Abstract. The ACE-FTS (Atmospheric Chemistry Experiment – Fourier Transform Spectrometer) instrument on the Canadian SCISAT satellite, which has been in operation for over 12 years, has the capability of deriving stratospheric profiles of many of the NOy (NO + NO2 + NO3 + 2 × N2O5 + HNO3 + HNO4 + ClONO2 + BrONO2) species. Version 2.2 of ACE-FTS NO, NO2, HNO3, N2O5, and ClONO2 have previously been validated, and this study compares the most recent version (v3.5) of these five ACE-FTS products to spatially and temporally coincident measurements from other satellite instruments–GOMOS, HALOE, MAESTRO, MIPAS, MLS, OSIRIS, POAM III, SAGE III, SCIAMACHY, SMILES, and SMR. For each ACE-FTS measurement, a photochemical box model was used to simulate the diurnal variations of the NOy species and the ACE-FTS measurements were scaled to the local times of the coincident measurements. The comparisons for all five species show good agreement with correlative satellite measurements. For NO in the altitude range of 25–50 km, the instrument-averaged mean relative differences are on the order of 0 to −10 %. They are approximately −10 % at 30–40 km for NO2, they are within ±7 % at 8–30 km for HNO3, they are better than −7% at 21–34 km for local morning N2O5, and better than −8 % at 21–34 km for ClONO2. Where possible, the variations in the mean differences due to changes in the comparison local time and latitude are also discussed.

scholarly journals Assessment of Spectra of the Atmospheric Infrared Ultraspectral Sounder on GF-5 and Validation of Water Vapor Retrieval

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 325
Author(s):  
Xifeng Cao ◽  
Xiaoying Li ◽  
Shuanghui Liu ◽  
Xinyuan Zhang
Keyword(s):  
Reliable Data ◽  
Dynamic Monitoring ◽  
Vertical Resolution ◽  
Spectral Quality ◽  
Spectral Bands ◽  
The Mean ◽  
Relative Differences ◽  
Level 2 ◽  
Better Than ◽  
Good Agreement

Atmospheric Infrared Ultraspectral Sounder (AIUS) aboard the Chinese GaoFen-5 satellite was launched on 9 May 2018. It is the first hyperspectral occultation spectrometer in China. The spectral quality assessment of AIUS measurements at the full and representative spectral bands was presented by comparing the transmittance spectra of measurements with that of simulations. AIUS measurements agree well with simulations. Statistics show that more than 73% of the transmittance differences are within ±0.05 and more than 91% of the transmittance differences are within ±0.1. The spectral windows for O3, H2O, temperature, CO, CH4, and HCl were also analyzed. The comparison experiments indicate that AIUS data can provide reliable data for O3, H2O, temperature, CO, CH4, and HCl detection and dynamic monitoring. The H2O profiles were then retrieved from AIUS measurements, and the precision, resolution, and accuracy of the H2O profiles are discussed. The estimated precision is less than 1.3 ppmv (21%) below 57 km and about 0.9–2.4 ppmv (20–31%) at 60–90 km. The vertical resolution of H2O profiles is better than 5 km below 32 km and about 5–8 km at 35–85 km. Comparisons with MLS Level 2 products indicate that the mean H2O profiles of AIUS have a good agreement with those of MLS. The relative differences are mostly within ±10% at 16–75 km and about 10–15% at 16–20 km in 60∘–80∘ S. For 60∘–65 ∘ S in December, the relative differences are within ±5% between 22 km and 80 km. The H2O profiles retrieved from AIUS measurements are credible for scientific research.

scholarly journals Behavior Modeling for a Beacon-Based Indoor Location System

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4839
Author(s):  
Aritz Bilbao-Jayo ◽  
Aitor Almeida ◽  
Ilaria Sergi ◽  
Teodoro Montanaro ◽  
Luca Fasano ◽  
...  
Keyword(s):  
Behavior Modeling ◽  
Percentage Error ◽  
Location Prediction ◽  
Indoor Environments ◽  
Prediction System ◽  
Indoor Location ◽  
The Mean ◽  
Locating System ◽  
Monitoring Devices ◽  
Do So

In this work we performed a comparison between two different approaches to track a person in indoor environments using a locating system based on BLE technology with a smartphone and a smartwatch as monitoring devices. To do so, we provide the system architecture we designed and describe how the different elements of the proposed system interact with each other. Moreover, we have evaluated the system’s performance by computing the mean percentage error in the detection of the indoor position. Finally, we present a novel location prediction system based on neural embeddings, and a soft-attention mechanism, which is able to predict user’s next location with 67% accuracy.

scholarly journals MAX-DOAS observations of aerosols, formaldehyde and nitrogen dioxide in the Beijing area: comparison of two profile retrieval approaches

2015 ◽  
Vol 8 (2) ◽  
pp. 941-963 ◽  
Author(s):  
T. Vlemmix ◽  
F. Hendrick ◽  
G. Pinardi ◽  
I. De Smedt ◽  
C. Fayt ◽  
...  
Keyword(s):  
Standard Deviation ◽  
A Priori ◽  
Systematic Bias ◽  
Aerosol Extinction ◽  
Data Set ◽  
Near Surface ◽  
Beijing Area ◽  
Least Squares Fit ◽  
Relative Differences ◽  
Good Agreement

Abstract. A 4-year data set of MAX-DOAS observations in the Beijing area (2008–2012) is analysed with a focus on NO2, HCHO and aerosols. Two very different retrieval methods are applied. Method A describes the tropospheric profile with 13 layers and makes use of the optimal estimation method. Method B uses 2–4 parameters to describe the tropospheric profile and an inversion based on a least-squares fit. For each constituent (NO2, HCHO and aerosols) the retrieval outcomes are compared in terms of tropospheric column densities, surface concentrations and "characteristic profile heights" (i.e. the height below which 75% of the vertically integrated tropospheric column density resides). We find best agreement between the two methods for tropospheric NO2 column densities, with a standard deviation of relative differences below 10%, a correlation of 0.99 and a linear regression with a slope of 1.03. For tropospheric HCHO column densities we find a similar slope, but also a systematic bias of almost 10% which is likely related to differences in profile height. Aerosol optical depths (AODs) retrieved with method B are 20% high compared to method A. They are more in agreement with AERONET measurements, which are on average only 5% lower, however with considerable relative differences (standard deviation ~ 25%). With respect to near-surface volume mixing ratios and aerosol extinction we find considerably larger relative differences: 10 ± 30, −23 ± 28 and −8 ± 33% for aerosols, HCHO and NO2 respectively. The frequency distributions of these near-surface concentrations show however a quite good agreement, and this indicates that near-surface concentrations derived from MAX-DOAS are certainly useful in a climatological sense. A major difference between the two methods is the dynamic range of retrieved characteristic profile heights which is larger for method B than for method A. This effect is most pronounced for HCHO, where retrieved profile shapes with method A are very close to the a priori, and moderate for NO2 and aerosol extinction which on average show quite good agreement for characteristic profile heights below 1.5 km. One of the main advantages of method A is the stability, even under suboptimal conditions (e.g. in the presence of clouds). Method B is generally more unstable and this explains probably a substantial part of the quite large relative differences between the two methods. However, despite a relatively low precision for individual profile retrievals it appears as if seasonally averaged profile heights retrieved with method B are less biased towards a priori assumptions than those retrieved with method A. This gives confidence in the result obtained with method B, namely that aerosol extinction profiles tend on average to be higher than NO2 profiles in spring and summer, whereas they seem on average to be of the same height in winter, a result which is especially relevant in relation to the validation of satellite retrievals.

Computational Investigation of Different Turbulent Models When Predicting Airflow in an Enclosure

2008 ◽  
Author(s):  
Xi Wang ◽  
Hassan Naji ◽  
Ahmed Mezrhab
Keyword(s):  
Numerical Investigation ◽  
Turbulence Models ◽  
Turbulent Stress ◽  
Computational Investigation ◽  
Isothermal Case ◽  
The Mean ◽  
Turbulent Models ◽  
Rsm Model ◽  
Cold Case ◽  
Good Agreement

In the present study, a numerical investigation is carried out for an isothermal case, a hot case and a cold case with FLUENT code. Three turbulence models are considered: the k-ε realisable model, the RNG k-ε model and the RSM linear model. The obtained results are compared to experiments and show generally a good agreement for the mean velocities and temperatures, but less satisfactory for the turbulent stress. The performance of the RSM model is remarkable. Even if none of the models is able to give the exact experimental pattern on the map of turbulence, the RSM model seems able to predict such configuration.

Compartmental modeling of the hepatic transport of taurocholate in the rat in vivo

1989 ◽  
Vol 257 (2) ◽  
pp. G210-G220 ◽  
Author(s):  
X. Deroubaix ◽  
T. Coche ◽  
E. Depiereux ◽  
E. Feytmans
Keyword(s):  
Excretion Rate ◽  
Compartmental Analysis ◽  
Hepatic Transport ◽  
Lumped Model ◽  
Perfusion Model ◽  
Direct Measurements ◽  
Distribution In Blood ◽  
Variability Model ◽  
Good Agreement

Compartmental analysis was used to study the hepatobiliary transport of taurocholate (TC) in the rat in vivo. The available data are the following: [14C]TC kinetics in blood and bile, weighting factors associated with these data and computed from a theoretical variability model, and TC excretion rate in bile. The lumped model that best fits the data contains five compartments: three compartments for TC distribution in blood and two compartments for the liver. It includes a compartmental representation of the laminar flow of bile in the collecting catheter. This model overestimates TC concentration in blood. A perfusion model that includes a compartment representing explicitly the sinusoidal TC concentration gradient was developed. TC concentration in blood estimated by this model is in good agreement with direct measurements, showing that the perfused model has a better descriptive capacity than the lumped model. The amounts of TC estimated in the two hepatic compartments are similar to values previously published.

scholarly journals Inflationary cosmology in unimodular F(T) gravity

2017 ◽  
Vol 32 (21) ◽  
pp. 1750114 ◽  
Author(s):  
Kazuharu Bamba ◽  
Sergei D. Odintsov ◽  
Emmanuel N. Saridakis
Keyword(s):  
Spectral Index ◽  
Teleparallel Gravity ◽  
Specific Model ◽  
Inflationary Cosmology ◽  
Model Parameters ◽  
De Sitter ◽  
Reconstruction Procedure ◽  
Additional Advantage ◽  
Slow Roll ◽  
Good Agreement

We investigate the inflationary realization in the context of unimodular F(T) gravity, which is based on the F(T) modification of teleparallel gravity, in which one imposes the unimodular condition through the use of Lagrange multipliers. We develop the general reconstruction procedure of the F(T) form that can give rise to a given scale-factor evolution, and then we apply it in the inflationary regime. We extract the Hubble slow-roll parameters that allow us to calculate various inflation-related observables, such as the scalar spectral index and its running, the tensor-to-scalar ratio, and the tensor spectral index. Then, we examine the particular cases of de Sitter and power-law inflation, of Starobinsky inflation, as well as inflation in a specific model of unimodular F(T) gravity. As we show, in all cases the predictions of our scenarios are in a very good agreement with Planck observational data. Finally, inflation in unimodular F(T) gravity has the additional advantage that it always allows for a graceful exit for specific regions of the model parameters.

Respiratory Exchange and Body Size in the Aldabra Giant Tortoise

1971 ◽  
Vol 55 (3) ◽  
pp. 651-665 ◽  
Author(s):  
G. M. HUGHES ◽  
R. GAYMER ◽  
MARGARET MOORE ◽  
A. J. WOAKES
Keyword(s):  
Body Weight ◽  
Body Size ◽  
Metabolic Rate ◽  
Relative Proportion ◽  
The Body ◽  
O2 Consumption ◽  
Weight Range ◽  
Testudo Hermanni ◽  
The Mean ◽  
Good Agreement

1. The O2 consumption and CO2 release of nine giant tortoises Testudo gigantea (weight range 118 g-35·5 kg) were measured at a temperature of about 25·5°C. Four European tortoises Testudo hermanni (weight range 640 g-2·16 kg) were also used. The mean RQ values obtained were 1·01 for T. gigantea and 0·97 for T. hermanni. These values were not influenced by activity or size. 2. The data was analysed by plotting log/log regression lines relating body weight to O2 consumption. Both maximum and minimum metabolic rates recorded for each individual T. gigantea showed a negative correlation with body weight. For active rates the relation was O2 consumption = 140·8W0·97, whereas for inactive animals O2 consumption = 45·47W0·82. 3. The maximum rates were obtained from animals that were observed to be active in the respirometer and the minimum rates from animals that remained quiet throughout. The scope for activity increased with body size, being 82 ml/kg/h for animals of 100 g and 103 ml/kg/h for 100 kg animals. The corresponding ratio between maximum and minimum rates increases from about 2 to 6 for the same weight range. 4. Values for metabolic rate in T. hermanni seem to be rather lower than in T. gigantea. Analysis of the relative proportion of the shell and other organs indicates that the shell forms about 31% of the body weight in adult T. hermanni but only about 18% in T. gigantea of similar size. The shell is not appreciably heavier in adult T. gigantea (about 20%). 5. Data obtained for inactive animals is in good agreement with results of other workers using lizards and snakes. Previous evidence suggesting that chelonians show no reduction in metabolic rate with increasing size is not considered to conflict with data obtained in the present work.

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