scholarly journals Investigating the Relation between Absorption and Gas Concentration in Gas Detection Using a Diffuse Integrating Cavity

2018 ◽  
Vol 8 (9) ◽  
pp. 1630 ◽  
Author(s):  
Xue Zhou ◽  
Jia Yu ◽  
Lin Wang ◽  
Zhiguo Zhang
Keyword(s):  
Transition Point ◽  
Light Transmission ◽  
Tunable Diode Laser ◽  
Gas Cell ◽  
Weak Absorption ◽  
Gas Concentration ◽  
Non Linear ◽  
The Relationship ◽  
Absorption Condition ◽  
Oxygen Concentrations

The relationship between absorption and gas concentration was studied using a diffuse integrating cavity as a gas cell. The light transmission process in an arbitrary diffuse cavity was theoretically derived based on a beam reflection analysis. It was found that a weak absorption condition must be satisfied to ensure a linear relationship between absorbance and gas concentration. When the weak absorption condition is not satisfied, a non-linear relation will be observed. A 35 × 35 × 35 cm diffuse integrating cavity was used in the experiment. Different oxygen concentrations were measured by detecting the P9 absorption line at 763.8 nm, based on tunable diode laser absorption spectroscopy. The relationship between the absorption signals and oxygen concentration was linear at low oxygen concentrations and became non-linear when oxygen concentrations were higher than 21%. The absorbance value of this transition point was 0.17, which was considered as the weak absorption condition for this system. This work studied the theoretical reason for the non-linear phenomenon and provided an experimental method to determine the transition point when using a diffuse integrating cavity as a gas cell.

Polarized microbeam FT-IR analysis of single fibers

1996 ◽  
Vol 54 ◽  
pp. 206-207
Author(s):  
Liling Cho ◽  
David L. Wetzel
Keyword(s):  
Molecular Orientation ◽  
Transition Point ◽  
Polymer Fibers ◽  
Single Fiber ◽  
Wire Grid ◽  
Polyester Fibers ◽  
Ft Ir ◽  
Ir Analysis ◽  
The Relationship ◽  
Wire Grid Polarizer

Polarized infrared microscopy has been used for forensic purposes to differentiate among polymer fibers. Dichroism can be used to compare and discriminate between different polyester fibers, including those composed of polyethylene terephthalate that are frequently encountered during criminal casework. In the fiber manufacturering process, fibers are drawn to develop molecular orientation and crystallinity. Macromolecular chains are oriented with respect to the long axis of the fiber. It is desirable to determine the relationship between the molecular orientation and stretching properties. This is particularly useful on a single fiber basis. Polarized spectroscopic differences observed from a single fiber are proposed to reveal the extent of molecular orientation within that single fiber. In the work presented, we compared the dichroic ratio between unstretched and stretched polyester fibers, and the transition point between the two forms of the same fiber. These techniques were applied to different polyester fibers. A fiber stretching device was fabricated for use on the instrument (IRμs, Spectra-Tech) stage. Tension was applied with a micrometer screw until a “neck” was produced in the stretched fiber. Spectra were obtained from an area of 24×48 μm. A wire-grid polarizer was used between the source and the sample.

Analysis of Maximum Expiratory Flow Volume Curves Using Canonical Correlation Analysis

1985 ◽  
Vol 24 (02) ◽  
pp. 91-100 ◽  
Author(s):  
W. van Pelt ◽  
Ph. H. Quanjer ◽  
M. E. Wise ◽  
E. van der Burg ◽  
R. van der Lende
Keyword(s):  
Correlation Analysis ◽  
Canonical Correlation Analysis ◽  
Canonical Correlation ◽  
Flow Volume ◽  
Non Linear ◽  
Maximum Expiratory Flow ◽  
Expiratory Flow ◽  
Relationship Of ◽  
The Relationship ◽  
Age And Sex

SummaryAs part of a population study on chronic lung disease in the Netherlands, an investigation is made of the relationship of both age and sex with indices describing the maximum expiratory flow-volume (MEFV) curve. To determine the relationship, non-linear canonical correlation was used as realized in the computer program CANALS, a combination of ordinary canonical correlation analysis (CCA) and non-linear transformations of the variables. This method enhances the generality of the relationship to be found and has the advantage of showing the relative importance of categories or ranges within a variable with respect to that relationship. The above is exemplified by describing the relationship of age and sex with variables concerning respiratory symptoms and smoking habits. The analysis of age and sex with MEFV curve indices shows that non-linear canonical correlation analysis is an efficient tool in analysing size and shape of the MEFV curve and can be used to derive parameters concerning the whole curve.

scholarly journals $$ T\overline{T} $$-like flows in non-linear electrodynamic theories and S-duality

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
H. Babaei-Aghbolagh ◽  
Komeil Babaei Velni ◽  
Davood Mahdavian Yekta ◽  
H. Mohammadzadeh
Keyword(s):  
Type Theory ◽  
Free Action ◽  
Momentum Tensor ◽  
Flow Equation ◽  
Supersymmetric Model ◽  
Deformation Problem ◽  
Dimensional Spacetime ◽  
Non Linear ◽  
The Relationship ◽  
Simple Integration

Abstract We investigate the $$ T\overline{T} $$ T T ¯ -like flows for non-linear electrodynamic theories in D(=2n)-dimensional spacetime. Our analysis is restricted to the deformation problem of the classical free action by employing the proposed $$ T\overline{T} $$ T T ¯ operator from a simple integration technique. We show that this flow equation is compatible with $$ T\overline{T} $$ T T ¯ deformation of a scalar field theory in D = 2 and of a non-linear Born-Infeld type theory in D = 4 dimensions. However, our computation discloses that this kind of $$ T\overline{T} $$ T T ¯ flow in higher dimensions is essentially different from deformation that has been derived from the AdS/CFT interpretations. Indeed, the gravity that may be exist as a holographic dual theory of this kind of effective Born-Infeld action is not necessarily an AdS space. As an illustrative investigation in D = 4, we shall also show that our construction for the $$ T\overline{T} $$ T T ¯ operator preserves the original SL(2, ℝ) symmetry of a non-supersymmetric Born-Infeld theory, as well as $$ \mathcal{N} $$ N = 2 supersymmetric model. It is shown that the corresponding SL(2, ℝ) invariant action fixes the relationship between the $$ T\overline{T} $$ T T ¯ operator and quadratic form of the energy-momentum tensor in D = 4.

Chloride Accumulation as a Homeostatic System: Negative Feedback Signals for Concentration and Turgor Maintenance Differ in a Glycophyte and a Halophyte

1980 ◽  
Vol 7 (3) ◽  
pp. 237 ◽  
Author(s):  
WJ Cram
Keyword(s):  
Negative Feedback ◽  
Turgor Maintenance ◽  
Non Linear ◽  
Steady Level ◽  
Homeostatic System ◽  
Chloride Accumulation ◽  
Relationship Of ◽  
The Relationship ◽  
Uptake Of Nutrients

Carrot tissue is taken as a representative glycophilic tissue. It accumulates K+, Cl- and total osmotica to a steady level after 10-15 days. This level of Cl- is nearly constant and is independent of external KCl concentration and of turgor. Cl- influx is also independent of turgor. It therefore appears that the Cl- accumulating system in carrot (and possibly in other glycophytes) can, under artificial conditions, act as a homeostat for intracellular C- concentration, and is not the basis of turgor maintenance. It is suggested that turgor might be maintained by controlled accumulation of K+ carboxylates in glycophytes. Beet tissue is taken as a representative halophilic tissue. It accumulates K+, Cl-, and total osmotica to a steady level after about 4 days. At this stage turgor is constant, due to differences in the levels of KCl accumulated. Cl- influx is stimulated by reducing turgor after a lag of 3-5 h. The relationship of Cl- influx to turgor is non-linear. It therefore appears that in beet (and possibly in other halophytes) turgor maintenance is based on the turgor-sensitive accumulation of Cl- salts. Cl- influx in beet is also affected by changes in intracellular Cl- concentration, as in carrot. It is suggested that this feedback relationship may primarily be part of a system for the controlled uptake of nutrients rather than of Cl- in both tissues.

A Fire Warning Method Using Tunable Diode Laser Absorption Spectroscopy

2021 ◽  
Vol 16 (2) ◽  
pp. 222-229
Author(s):  
Lin Feng ◽  
Jian Wang ◽  
Chao Ding
Keyword(s):  
Diode Laser ◽  
Absorption Spectroscopy ◽  
Gas Absorption ◽  
Tunable Diode Laser ◽  
Laser Absorption Spectroscopy ◽  
Gas Concentration ◽  
Laser Absorption ◽  
Output Wavelength ◽  
Light Beams ◽  
Diode Laser Absorption

Tunable diode laser absorption spectroscopy (TDLAS) technology is adopted herein to detect fire gas produced in the early stage of the fire. Based on this technology, a fire warning detection system with multiple lasers and detectors is proposed. Multiple drivers input laser’s temperature and injected current data, making its output wavelength consistent with the measured gas’ absorption peak wavelengths in absorption spectroscopy. Multiple light beams are coupled to the same optical fiber. After the light beams pass through the long optical path absorption cell filled with fire gas, the beams are separated by a converter. The signals are demodulated by different detectors and further analyzed for fire warnings. After the fire warning system’s design, the system’s various hardware modules are designed, including the light source module, TDLAS controller, gas chamber module, photoelectric detector, and data collection. When the temperature remains unchanged, the output wavelength is linearly related to the injected current. When the injected current remains unchanged, the output wavelength is linearly related to the operating temperature. With a semiconductor laser’s injected current of 40 mA, the initial temperature of 38.6 °C, and the output wavelength of 1578.16 nm, the output wavelength increases continuously as the temperature increases. The harmonic signal amplitude after gas absorption is positively correlated with the measured gas concentration, indicating that the second harmonic signals can estimate the fire gas concentration.

THU0504 The Relationship Between Weight Loss and Reduced Cartilage Loss in the Medial Knee Joint is Non-Linear in Obese People

2013 ◽  
Vol 72 (Suppl 3) ◽  
pp. A334.1-A334
Author(s):  
A. Wluka ◽  
A. Teichtahl ◽  
S. Tanamas ◽  
Y. Wang ◽  
B. Strauss ◽  
...  
Keyword(s):  
Weight Loss ◽  
Knee Joint ◽  
Cartilage Loss ◽  
Obese People ◽  
Medial Knee ◽  
Non Linear ◽  
The Relationship

scholarly journals Pendulum with aerodynamic and viscous damping

2020 ◽  
Vol 3 (2) ◽  
pp. 43-47
Author(s):  
Herlin Soraya
Keyword(s):  
Differential Equations ◽  
Stable State ◽  
The State ◽  
Linear Differential Equations ◽  
Viscous Damping ◽  
Viscous Damper ◽  
Aerodynamic Damping ◽  
Non Linear ◽  
Linear Differential ◽  
The Relationship

In this paper we discuss about how the relationship between non-linear differential equations on aerodynamic damping with linearly viscous damping equations. And it turns out after analyzing that the changes that occur pendulum that changes from the start of the maximum state to a stable state takes time so that changes that occur until the state is stable, this change can be reduced with the use of viscous damper

scholarly journals Relationship Between Creatinine and Body Weight Ratio and Diabetes Mellitus in a Chinese Cohort Study

2021 ◽  
Author(s):  
Xinyu Wang ◽  
Zhuangsen Chen ◽  
Fan Yang ◽  
Xiaohan Ding ◽  
Changchun Cao ◽  
...  
Keyword(s):  
Body Weight ◽  
Missing Values ◽  
Proportional Hazards ◽  
Cox Regression ◽  
Weight Ratio ◽  
Cox Proportional Hazards ◽  
Additive Models ◽  
Cox Regression Analysis ◽  
Non Linear ◽  
The Relationship

Abstract Background: Research on the relationship between Creatinine to Body Weight Ratios (Cre/BW ratios) and the prevalence of diabetes is still lacking. The aim of this study was to investigate the potential association between Cre/BW ratios and incident of diabetes in Chinese adults.Methods: This retrospective study was conducted in 199,526 patients from Rich Healthcare Group in China from 2010 to 2016. The participants were divided into quartiles of the Cre/BW ratios. Multivariate multiple imputation and dummy variables were used to handle missing values. Cox proportional-hazards regression was used to investigate the association of Cre/BW and diabetes. Generalized additive models(GAM) were used to identify non-linear relationships.Results: Of all participants,after handling missing values and adjustment for potential confounders, the multivariate Cox regression analysis results showed that Cre/BW ratios was inversely associated with diabetes risk( HR: 0.268; 95% CI:0.229 to 0.314, P < 0.00001).For men, the hazard ratios(HRs) of incident diabetes was 0.255(95%CI: 0.212-0.307);and for women HR= 0.297 (95%CI: 0.218-0.406).Moreover, sensitivity analysis confirmed the stability of the results. Furthermore, GAM revealed a saturation effect on the independent association between Cre/BW and incident of diabetes.Conclusions: This study demonstrated that increased Cre/BW is negatively correlated with incident of diabetes in Chinese for the first time. And we found that the relationship between Cre/BW and incident of diabetes was non-linear.

scholarly journals Weather Prediction using Advanced Machine Learning Techniques

2021 ◽  
Vol 2089 (1) ◽  
pp. 012059
Author(s):  
G. Hemalatha ◽  
K. Srinivasa Rao ◽  
D. Arun Kumar
Keyword(s):  
Linear Relationship ◽  
Weather Prediction ◽  
Weather Condition ◽  
Weather Conditions ◽  
Machine Learning Techniques ◽  
Weather Data ◽  
Learning Techniques ◽  
Proposed Model ◽  
Non Linear ◽  
The Relationship

Abstract Prediction of weather condition is important to take efficient decisions. In general, the relationship between the input weather parameters and the output weather condition is non linear and predicting the weather conditions in non linear relationship posses challenging task. The traditional methods of weather prediction sometimes deviate in predicting the weather conditions due to non linear relationship between the input features and output condition. Motivated with this factor, we propose a neural networks based model for weather prediction. The superiority of the proposed model is tested with the weather data collected from Indian metrological Department (IMD). The performance of model is tested with various metrics..

scholarly journals Government Size and Corruption: A Non-linear Analysis in the Case of EMCCA

2021 ◽  
Vol 12 (4) ◽  
pp. 17
Author(s):  
Assoumou Ondo ◽  
Beau Jency Owono Ondo
Keyword(s):  
Linear Relationship ◽  
Central Government ◽  
Central Africa ◽  
Linear Analysis ◽  
Government Size ◽  
Economic Community ◽  
Non Linear ◽  
The Government ◽  
The Impact ◽  
The Relationship

This article analyzes the relationship between Government size and corruption. Unlike the works in the way which suppose a linear relationship between the two variables, we estimate a panel with change of the modes to characterize the impact of the size of the Central Government on corruption, in the countries of the economic community and monetary of Central Africa (EMCCA). The results show that there is a non-linear relationship between these two variables. Indeed, a strong involvement of the Government in economic activity results in a significant increase in corruption when the Government exceeds a size of 13.5508% of the GDP.

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