Определение времени продольной релаксации текущей жидкости ядерно-магнитным спектрометром дифференциального типа

The necessity of simultaneous measurement of the longitudinal T1 and transverse T2 relaxation times for monitoring the state of the flowing liquid during the study in the range of flow rate q changes by at least two orders of magnitude has been substantiated. A new method for measuring T1 has been developed. For its implementation, the design of a differential nuclear magnetic spectrometer has been proposed, which makes it possible to measure T1 in the entire range of measurement of flow rate q. The results of experimental studies are presented.

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Особенности исследования состояния текущей среды методом ядерного магнитного резонанса

Письма в журнал технической физики ◽

10.21883/pjtf.2020.02.48943.18036 ◽

2020 ◽

Vol 46 (2) ◽

pp. 8

Author(s):

В.В. Давыдов ◽

Н.С. Мязин ◽

В.И. Дудкин ◽

Р.В. Давыдов

Keyword(s):

Nuclear Magnetic Resonance ◽

Magnetic Resonance ◽

Signal To Noise Ratio ◽

Relaxation Times ◽

The State ◽

T2 Relaxation ◽

Signal To Noise ◽

Flowing Liquid ◽

Registration System ◽

Nuclear Magnetic

The features of the state investigation of a flowing liquid by nuclear magnetic resonance was defined. The methodology for the state investigation of the flowing medium by changing the values of the longitudinal T1 and transverse T2 relaxation times is justified. For the parameters of the registration system of the signal of nuclear magnetic resonance and magnetic fields are established relations between them. The implementation of these ratios allows to obtain a signal to noise ratio of more than 5 for carrying out measurements of T1 and T2 values in real time with an error not exceeding 1%. The results of experimental research are presented.

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Новый метод измерения показателя преломления текущей жидкости

Оптика и спектроскопия ◽

10.21883/os.2021.07.51088.1660-21 ◽

2021 ◽

Vol 129 (7) ◽

pp. 954

Author(s):

В.В. Давыдов ◽

А.В. Мороз ◽

Д.И. Николаев

Keyword(s):

Refractive Index ◽

Laser Radiation ◽

Vertical Section ◽

Experimental Studies ◽

New Method ◽

Practical Implementation ◽

Multiple Reflections ◽

Optical Elements ◽

Flowing Liquid ◽

Flow Through

The necessity of developing a new method for measuring the refractive index of a liquid in a turbulent mode of its flow in a pipeline is substantiated. A new method for measuring the refractive index of a medium n is presented. For its practical implementation, a new design of a flow-through refractometer has been developed, which makes it possible to measure n in both laminar and turbulent fluid flow. A new design of the optical part of the refractometer is considered. A new way of placing it on the vertical section of the pipeline for measuring n is proposed. All this makes it possible to make insignificant the influence on the measurement result of n flowing liquid of errors associated with multiple reflections of laser radiation from optical elements, with the formation of voids or vortex flows in the pipeline and with temperature fluctuations. In the design of a refractometer with a new method for measuring n, there are no restrictions on determining the value of n of a flowing liquid, in contrast to the used industrial flow-through refractometers, the principle of which is based on the phenomenon of total internal reflection of laser radiation at the interface of two media. The results of experimental studies of various media are presented.

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Review of NMR Studies for Oilwell Cements and Their Importance

ChemEngineering ◽

10.3390/chemengineering5020018 ◽

2021 ◽

Vol 5 (2) ◽

pp. 18

Author(s):

Fatemeh K. Saleh ◽

Catalin Teodoriu ◽

Carl Sondergeld

Keyword(s):

Relaxation Times ◽

Experimental Studies ◽

Operating Characteristics ◽

T2 Relaxation ◽

Nmr Studies ◽

Cement Pastes ◽

Curing Conditions ◽

Work Related ◽

Data Comparison ◽

Water Response

This paper summarizes experimental studies using Nuclear Magnetic Resonance (NMR) to evaluate cement porosity, pore size distribution, and other characteristics such as Calcium Silicate Hydrate (CSH) gel structure and morphology. The first known paper on NMR experiments to investigate cement pastes was published in 1978. Two main NMR parameters, the so-called longitudinal T1 and transverse T2 relaxation times, are commonly measured and analyzed, representing the water response which is trapped in the cement. The hydration process reported in this paper was found to be monitored from as low as 10 min to longer than 365 days. Other studies conducted experiments by using NMR, especially during the 1980s. These studies employed variations in methodologies and frequencies, making data comparison difficult. Additionally, different spectrometers and NMR concepts, as well as operating characteristics, were used. Therefore, it is challenging to reconcile results from previous NMR studies on cement. Other significant hurdles are different cement types, water/cement ratio, and curing conditions. One notable observation is that there has not been any comprehensive laboratory work related to NMR on oilfield cement types, including porosity and hydration. Two recent studies have presented NMR measurements on class G and class H cements.

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On the need to control the state of the upper edge of the prism in a flow-through refractometer for measurements with an error less than 10−4

Journal of Physics Conference Series ◽

10.1088/1742-6596/2086/1/012145 ◽

2021 ◽

Vol 2086 (1) ◽

pp. 012145

Author(s):

F A Isakov ◽

V V Davydov ◽

V Yu Rud

Keyword(s):

Thin Film ◽

Refractive Index ◽

Measurement Error ◽

Technological Process ◽

Experimental Studies ◽

The State ◽

Flowing Liquid ◽

Upper Face ◽

Flow Through ◽

Negative Factors

Abstract The article substantiates the need to use a flow-through refractometer to control the state of a flowing liquid during scientific research, when automating a technological process, etc. The main negative factors that affect an increase in the measurement error of the refractive index n of a flowing liquid are determined. It was found that one of these factors is the formation of a thin film (plaque) on the upper face of the prism, which is in contact with the medium under study. The study of the influence of this film on the measurement error has been carried out. A method has been developed to eliminate plaque from the upper face of the prism during the operation of the refractometer. The results of experimental studies are presented.

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The new method for longitudinal relaxation time control of flowing liquid in the entire range of its expenditure measuring

Izmeritel`naya Tekhnika ◽

10.32446/0368-1025it.2020-5-36-42 ◽

2020 ◽

pp. 36-42

Author(s):

Vadim V. Davydov ◽

Nikita S. Myazin ◽

Sergey S. Makeev ◽

Valentin I. Dudkin

Keyword(s):

Nuclear Magnetic Resonance ◽

Relaxation Time ◽

Magnetic Resonance ◽

Entire Range ◽

New Method ◽

Longitudinal Relaxation Time ◽

Flowing Fluid ◽

Flowing Liquid ◽

Longitudinal Relaxation ◽

Nuclear Magnetic

The problems of the condition control of flowing liquid during its use in different industries, energy and agriculture are reviewed. The devices of the flowing liquid condition control whose operating principle is based on the phenomenon of nuclear magnetic resonance are presented. This devices do not have the disadvantages and limitations of use inherent in optical analyzers and flowing refractometers. At using controls based on the phenomenon of nuclear magnetic resonance the controlled parameters are the relaxation times of the flowing fluid, in particular, the greatest difficulties arise when measuring the longitudinal relaxation time. The method for control of longitudinal relaxation time T1 of flowing liquid in the entire range of measuring its expenditure is proposed. To implement a new method the design of nuclear magnetic flowmeter-relaxometer is developed. The obtained data are compared with the measurement results of values T1 for liquid media being in a stationary state are recived on industrial nuclear magnetic relaxometer and is determined them coincidence within the measurement error.

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Formation of the Traffic Flow Rate under the Influence of Traffic Flow Concentration in Time at Controlled Intersections in Tyumen, Russian Federation

Sustainability ◽

10.3390/su13158324 ◽

2021 ◽

Vol 13 (15) ◽

pp. 8324

Author(s):

Viacheslav Morozov ◽

Sergei Iarkov

Keyword(s):

Traffic Flow ◽

Flow Rate ◽

Traffic Congestion ◽

Traffic Management ◽

System Analysis ◽

Motor Vehicle ◽

Experimental Studies ◽

Transport Systems ◽

Experiment Planning ◽

Traffic Light

Present experience shows that it is impossible to solve the problem of traffic congestion without intelligent transport systems. Traffic management in many cities uses the data of detectors installed at controlled intersections. Further, to assess the traffic situation, the data on the traffic flow rate and its concentration are compared. Latest scientific studies propose a transition from spatial to temporal concentration. Therefore, the purpose of this work is to establish the regularities of the influence of traffic flow concentration in time on traffic flow rate at controlled city intersections. The methodological basis of this study was a systemic approach. Theoretical and experimental studies were based on the existing provisions of system analysis, traffic flow theory, experiment planning, impulses, probabilities, and mathematical statistics. Experimental data were obtained and processed using modern equipment and software: Traficam video detectors, SPECTR traffic light controller, Traficam Data Tool, SPECTR 2.0, AutoCad 2017, and STATISTICA 10. In the course of this study, the authors analyzed the dynamics of changes in the level of motorization, the structure of the motor vehicle fleet, and the dynamics of changes in the number of controlled intersections. As a result of theoretical studies, a hypothesis was put forward that the investigated process is described by a two-factor quadratic multiplicative model. Experimental studies determined the parameters of the developed model depending on the directions of traffic flow, and confirmed its adequacy according to Fisher’s criterion with a probability of at least 0.9. The results obtained can be used to control traffic flows at controlled city intersections.

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