scholarly journals MONITORING OF THE FERMENTATION PROCESS IN VARIOUS TYPES OF WINE

Russian vine ◽  
2021 ◽  
Vol 18 ◽  
pp. 48-58
Author(s):  
R.G. Timofeev Timofeev ◽  
Keyword(s):  
Refractive Index ◽  
Volume Fraction ◽  
Sugar Content ◽  
Liquid Media ◽  
Express Method ◽  
Standard Equipment ◽  
Grape Must ◽  
Technical Specifications ◽  
Non Destructive ◽  
Simultaneous Measuring

A classical approach to monitoring the fer-mentation of grape must based on the use of the areometric method is considered. Based on the processing of the data of measuring the refractive index and density of grape must, as well as data on the physicochemical composi-tion of grape must during fermentation, meth-odological approaches have been developed to create methods for monitoring the composi-tion of the fermenting must using refractomet-ric and refractodensimetric methods of analy-sis. The results of the work can become the basis for the development of a non-destructive express method for determining the volume fraction of ethyl alcohol and the mass concentration of sugars in fermenting must based on the standard equipment of the laboratory of wine-making enterprises, and for the improvement of technical specifications for the manufacture of a portable device for determining the concentration of alcohol and sugar content, based on the simultaneous measuring the refractive index and density of liquid media.

scholarly journals Development of a refractodensimetric method for determining the content of ethyl alcohol and total wine extract by a computer

2020 ◽  
Vol 10 (4) ◽  
pp. 3-11
Author(s):  
R. G. Timofeev
Keyword(s):  
Mathematical Model ◽  
Refractive Index ◽  
Ethyl Alcohol ◽  
Mass Concentration ◽  
Volume Fraction ◽  
Metrological Certification ◽  
Total Extract ◽  
Standard Equipment ◽  
Technical Specifications ◽  
Non Destructive

The work is devoted to the improvement of the methodological foundations of the refractodensimetric method of analysis as applied to liquid alcohol-containing products of grape winemaking. The regularities of changes in density and specific refraction of ethyl alcohol and substances of the extract of grapes and wine depending on their concentration based on the processing of the data of measuring the refractive index and density of various alcohol-containing products of winemaking and model solutions based on them, as well as based on the analysis of data from official densimetric and refractometric tables to determine the concentration of aqueous solutions of ethyl alcohol and total extract of the must, has been determined. The improved mathematical model of an alcoholic drink is proposed, which adequately describes the dependence of the refractive index and density of the drink on the content of ethyl alcohol and extract, based on the use of the additivity property of the specific refraction and the mass of the components of its constituents. On the basis of the proposed mathematical model of the drink, an algorithm has been developed for determining the volume fraction of ethyl alcohol and the mass concentration of the total extract for winemaking products, based on measuring the density and refractive index as the basis for the method for determining the volume fraction of ethyl alcohol and the mass concentration of the total extract. Preliminary metrological certification of the method for determining the mass concentration of the total extract and the volume fraction of ethyl alcohol in alcohol-containing products of grape winemaking has been carried out. The results of the work can be the basis for the development of a non-destructive express method for determining the volume fraction of ethyl alcohol and the mass concentration of the total extract based on the standard equipment of the laboratory of wineries, as well as the development of technical specifications for the manufacture of a portable device for determining the concentration of alcohol and extract based on the simultaneous measurement of the refractive index and density of liquid media.

Solid–liquid–liquid phase envelopes from temperature-scanned refractive index data

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Alcides J. Sitoe ◽  
Franco Pretorius ◽  
Walter W. Focke ◽  
René Androsch ◽  
Elizabeth L. du Toit
Keyword(s):  
Refractive Index ◽  
Liquid Phase ◽  
Volume Fraction ◽  
Solution Temperature ◽  
Linear Behavior ◽  
Upper Critical Solution Temperature ◽  
Novel Method ◽  
Using Data ◽  
Solid Liquid ◽  
Liquid Liquid Phase Separation

Abstract A novel method for estimating the upper critical solution temperature (UCST) of N,N-diethyl-m-toluamide (DEET)-polyethylene systems was developed. It was validated using data for the dimethylacetamide (DMA)-alkane systems which showed that refractive index mixing rules, linear in volume fraction, can accurately predict mixture composition for amide-alkane systems. Furthermore, rescaling the composition descriptor with a single adjustable parameter proved adequate to address any asymmetry when modeling the DMA-alkane phase envelopes. This allowed the translation of measured refractive index cooling trajectories of DEET-alkane systems into phase diagrams and facilitated the estimation of the UCST values by fitting the data with an adjusted composition descriptor model. For both the DEET- and DMA-alkane systems, linear behavior of UCST values in either the Flory–Huggins critical interaction parameter, or the alkane critical temperature, with increasing alkane molar mass is evident. The UCST values for polymer diluent systems were estimated by extrapolation using these two complimentary approaches. For the DEET-polyethylene system, values of 183.4 and 180.1 °C respectively were obtained. Both estimates are significantly higher than the melting temperature range of polyethylene. Initial liquid–liquid phase separation is therefore likely to be responsible for the previously reported microporous microstructure of materials formed from this binary system.

NMR Technique for Multiphase Fluid Study Involving Melting Phenomena

1999 ◽  
Author(s):  
Q. Ni ◽  
J. D. King ◽  
Y.-X. Tao
Keyword(s):  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Melting Rate ◽  
Analysis Method ◽  
Image Analysis Method ◽  
Equilibrium Conditions ◽  
Multiphase Fluid ◽  
Physical Phenomena ◽  
Non Destructive ◽  
Good Agreement

Abstract Nuclear magnetic resonance (NMR) sensors are used to determine the time variation of solid mass for a packed ice bed in an experiment of convective melting under non-thermal equilibrium conditions. The paper describes the basic experimental technique for NAFTM apparatus and feasibility for determining the solid volume fraction and ultimately the melting rate. The NMR technique provides an effective, non-destructive method for multiphase fluid study where phase change is one of the important physical phenomena. The results show a good agreement of data obtained by the NMR method with those from image-analysis method.

Nondestructive Extraction of Parameters of Multilayered Media Using Terahertz Pulse Technique

Frequenz ◽  
2019 ◽  
Vol 73 (1-2) ◽  
pp. 63-70
Author(s):  
Surya Prakash Singh ◽  
Nilesh K. Tiwari ◽  
M. Jaleel Akhtar
Keyword(s):  
Refractive Index ◽  
Complex Refractive Index ◽  
Multilayered Structure ◽  
Terahertz Pulse ◽  
Destructive Testing ◽  
Multilayered Media ◽  
Pulse Technique ◽  
Non Invasive ◽  
Full Wave ◽  
Non Destructive

Abstract In this work, an efficient non-invasive terahertz pulse technique is proposed and investigated to determine the thickness and refractive index of each layer in an optically thick stratified media. A closed form formulations are derived for simultaneous extraction of the thickness and complex refractive index of each layer with the help of primary reflected signals from the multilayered structure. The proposed technique is numerically tested using a full wave electromagnetic simulator and is experimental verified in the millimeter wave frequency range by utilizing the power peaks corresponding to the primary reflected signals. The numerical and measured results of multilayered samples under test are in good agreement with the reference data. The proposed terahertz pulse technique can be used for non-destructive testing of the multilayered system existing in various industries.

scholarly journals Automatic Characterization of the Refractive Index Profile of Fibers by Interferometry

2002 ◽  
Vol os-11 (1) ◽  
pp. 1558925002OS-01
Author(s):  
Han Seong Kim ◽  
Behnam Pourdeyhimi
Keyword(s):  
Refractive Index ◽  
Interference Fringe ◽  
Axial Direction ◽  
Refractive Index Profile ◽  
Path Difference ◽  
Fringe Field ◽  
Index Profile ◽  
Degree Of Orientation ◽  
Non Destructive

Interferometry provides a non-destructive method for examining the refractive index profile or the radial birefringence distribution within fibers. The key step in the interference data reduction involves the extraction of the refractive index profile along the axial direction of the fiber. The profile is due to the path difference between the fiber and the immersion liquid when a fiber is oriented perpendicular to the fringe field in an interference microscope. The refractive index provides a measure of the degree of optical anisotropy and is indicative of the degree of orientation of the structure. This is of particular interest to nonwovens because in thermally bonded nonwovens, the orientation plays a major role in how well the fibers are bonded and the ultimate properties of the fabric. Despite its long history, however, the interpretation of the interference fringe shift is not precisely defined. Consequently, the data are not reproducible from one laboratory to the next. We outline below an objective and quantitative method for precisely measuring a fiber's refractive index profile from a digitized image of the interference fringe. This new algorithm uses the Fast Fourier Transform (FFT) to remove the inherent noise present in the fiber interferogram and to aid in extracting the profile.

scholarly journals Method of Multi-Angle Transmission Radiowave Tomography of Dielectric Objects

2020 ◽  
Vol 10 (9) ◽  
pp. 3270
Author(s):  
Dmitry Sukhanov ◽  
Kseniya Zavyalova
Keyword(s):  
Refractive Index ◽  
Time Delay ◽  
Homogeneous Medium ◽  
Projection Algorithm ◽  
Propagation Time ◽  
Destructive Testing ◽  
Internal Structures ◽  
Diffraction Effects ◽  
Dielectric Objects ◽  
Non Destructive

A method for solving the inverse problem for reconstructing the spatial distribution of dielectric permittivity from the results of multi-angle transmission broadband radiosounding is proposed. The method is based on inverse wave propagation. The average refractive index of the medium along the wave trajectory is calculated by comparing the results of the calculation of the time delay of the inverse signal in the entire sounding region and the forward propagation time in a homogeneous medium. This method takes into account diffraction effects in solving a direct problem, which allows one to obtain a resolution in the order of a wavelength. The combination of time delays obtained at different probing angles allows the restoration of the distribution of the refractive index in the medium. The paper presents the results of the numerical simulation of this method. The novelty of the proposed approach compared to the conventional back-projection algorithm is that ray approximation is not applied. Instead of the absorption coefficient (used in X-ray tomography), a time delay is considered, which is restored in the entire probed region. The developed method can be widely used in radiowave tomography or microwave tomography for remote non-destructive testing, diagnostics for the internal structures of inhomogeneous media and the restoration of the shapes of opaque objects based on multisensor sensing.

scholarly journals Instrumentation for Simultaneous Non-Destructive Profiling of Refractive Index and Rare-Earth-Ion Distributions in Optical Fiber Preforms

Instruments ◽  
2018 ◽  
Vol 2 (4) ◽  
pp. 23 ◽  
Author(s):  
Marilena Vivona ◽  
Michalis Zervas
Keyword(s):  
Refractive Index ◽  
Rare Earth ◽  
Optical Fiber ◽  
Communication Systems ◽  
Optical Tomography ◽  
Dopant Distribution ◽  
Fiber Preform ◽  
Rare Earth Ion ◽  
Non Destructive ◽  
Fiber Preforms

We present a non-destructive technique for a combined evaluation of refractive index and active-dopant distribution in the same position along a rare-earth-doped optical fiber preform. The method relies on luminescence measurements, analyzed through an optical tomography technique, to define the active dopant distribution and ray-deflection measurements to calculate the refractive index profile. The concurrent evaluation of both the preform refractive index and the active dopant profiles allows for an accurate establishment of the dopant distribution within the optical core region. This combined information is important for the optimization and development of a range of advanced fibers, used, for example, in a high-power fiber lasers and modern spatial-division-multiplexing optical communication systems. In addition, the non-destructive nature allows the technique to be used to identify the most appropriate preform segment, thus increasing fiber yield and reducing development cycles. We demonstrate the technique on an Yb3+-doped aluminosilicate fiber preform and compare it with independent refractive index and active-dopant measurements. This technique will be useful for quality evaluation and optimization of optical fiber preforms and lends itself to advanced instrumentation.

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