scholarly journals VISCOMETRY OF NANODISPERSE MAGNETIC LIQUIDS AND LUBRICATING OILS. 2. METROLOGICAL ANALYSIS OF A DEVICE FOR RHEOLOGICAL STUDIES OF MAGNETIC NANODISPERSE LIQUID MEDIA

2021 ◽  
pp. 56-64
Author(s):  
Александр Николаевич Болотов ◽  
Ольга Олеговна Новикова ◽  
Владимир Валентинович Мешков
Keyword(s):  
Measurement Error ◽  
Systematic Error ◽  
Metrological Analysis ◽  
Improve Design ◽  
Measuring Cylinder ◽  
Methodological Errors ◽  
Magnetic Liquids ◽  
Total Measurement Error ◽  
Experimental Values ◽  
Rotary Viscometer

Проведен анализ основных источников методических погрешностей магнитного ротационного вискозиметра, позволивший усовершенствовать конструкцию и исключить критические режимы исследований. Теоретическая оценка систематической погрешности прибора показала, что значение относительной ошибки измерений можно довести до значения менее 1%. Наибольший вклад в систематическую погрешность прибора вносит нестабильность температурного режима исследуемой наножидкости и неточность определения высоты слоя жидкости, контактирующего с измерительным цилиндром. Измерение вязкости эталонных жидкостей на магнитном вискозиметре показало, что экспериментальные значения незначительно, примерно на 0,9% завышены. Тарировка прибора на различных эталонных жидкостях позволила снизить суммарную ошибку измерений до десятых долей процента. Магнитный ротационный вискозиметр может найти применение при нестандартных научных исследованиях структуры и реологических характеристик наножидкостей, для оперативного контроля процессов синтеза магнитных жидкостей и аттестации магнитных наножидкостей, предназначенных для технического применения. An analysis is carried out of the main sources of methodological errors of the magnetic rotary viscometer. The analysis allowed to improve design and to eliminate critical modes of the research. Theoretical evaluations of the systematic error of the device showed that the value of the relative measurement error can be brought to a value of less than 1%. The greatest contribution to the systematic error of the device is made by the instability of the temperature regime of the nanofluid under study and by the inaccuracy of determining the height of the liquid layer in contact with the measuring cylinder. The measurement of the viscosity of the reference liquids on the magnetic viscometer showed that experimental values are slightly, by about 0.9% overestimated. Calibration of the device on various reference liquids allowed reducing the total measurement error down to tenths of a percent. The magnetic rotary viscometer can be used in non-standard scientific studies of the structure and rheological characteristics of nanofluids, for operational control of the processes of synthesis of magnetic liquids and certification of magnetic nanofluids intended for technical use.

scholarly journals Tilt error in cryospheric surface radiation measurements at high latitudes: a model study

2016 ◽  
Vol 10 (2) ◽  
pp. 613-622 ◽  
Author(s):  
Wiley Steven Bogren ◽  
John Faulkner Burkhart ◽  
Arve Kylling
Keyword(s):  
Measurement Error ◽  
Total Error ◽  
Surface Radiation ◽  
Cloud Optical Depth ◽  
Model Study ◽  
Tilt Error ◽  
Total Measurement Error ◽  
Spectral Ranges ◽  
Radiation Measurements

Abstract. We have evaluated the magnitude and makeup of error in cryospheric radiation observations due to small sensor misalignment in in situ measurements of solar irradiance. This error is examined through simulation of diffuse and direct irradiance arriving at a detector with a cosine-response fore optic. Emphasis is placed on assessing total error over the solar shortwave spectrum from 250 to 4500 nm, as well as supporting investigation over other relevant shortwave spectral ranges. The total measurement error introduced by sensor tilt is dominated by the direct component. For a typical high-latitude albedo measurement with a solar zenith angle of 60°, a sensor tilted by 1, 3, and 5° can, respectively introduce up to 2.7, 8.1, and 13.5 % error into the measured irradiance and similar errors in the derived albedo. Depending on the daily range of solar azimuth and zenith angles, significant measurement error can persist also in integrated daily irradiance and albedo. Simulations including a cloud layer demonstrate decreasing tilt error with increasing cloud optical depth.

scholarly journals An Improved STEM/EDX Quantitative Method for Dopant Profiling at the Nanoscale

2020 ◽  
Vol 26 (1) ◽  
pp. 76-85
Author(s):  
Raghda Makarem ◽  
Filadelfo Cristiano ◽  
Dominique Muller ◽  
Pier Francesco Fazzini
Keyword(s):  
Measurement Error ◽  
Mass Density ◽  
Estimation Procedure ◽  
Observation Time ◽  
Test Structure ◽  
Profile Measurement ◽  
Rutherford Back Scattering ◽  
Dopant Profiling ◽  
Absorption Correction ◽  
Total Measurement Error

AbstractIn this paper, an improved quantification technique for STEM/EDX measurements of 1D dopant profiles based on the Cliff-Lorimer equation is presented. The technique uses an iterative absorption correction procedure based on density models correlating the local mass density and composition of the specimen. Moreover, a calibration and error estimation procedure based on linear regression and error propagation is proposed in order to estimate the total measurement error in the dopant density. The proposed approach is applied to the measurement of the As profile in a nanodevice test structure. For the calibration, two crystalline Si specimens implanted with different As doses have been used, and the calibration of the Cliff-Lorimer coefficients has been carried out using Rutherford Back Scattering measurements. The As profile measurement has been carried out on an FinFET test structure, showing that quantitative results can be obtained in the nanometer scale and for dopant atomic densities lower than 1%. Using the proposed approach, the measurement error and detection limit for our experimental setup are calculated and the possibility to improve this limit by increasing the observation time is discussed.

On the Source of the Systematic Error of the Pressure Measurement Film Applied to Wheel–Rail Normal Contact Measurements

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Jagoba Lekue ◽  
Florian Dörner ◽  
Christian Schindler
Keyword(s):  
Finite Element ◽  
Measurement Error ◽  
Systematic Error ◽  
Pressure Measurement ◽  
Element Model ◽  
Normal Contact ◽  
Failure Pressure ◽  
Research Activities ◽  
Element Failure ◽  
Simulation Results

This paper presents research activities regarding the systematic error of the pressure measurement film when measuring the area of the wheel–rail contact. In particular, an explanation for the different error values shown by the different film types was sought. A finite element model was created based on the assumption that not only the film, but also the microcapsules on top of it alter the results. The performance of the existing film models was enhanced by defining microcapsules with element failure and deletion behaviors. The new model was capable of reproducing the trend shown by the systematic error in the experiments. The simulation results confirmed that the measurement error of a certain film type is not only caused by the film itself, but also depends on the failure pressure and especially the diameter of the capsules.

scholarly journals Application of an automated complex resistance and phase difference measuring method for rheographic studies of human cardiovascular system

2021 ◽  
Vol 2086 (1) ◽  
pp. 012113
Author(s):  
A I Levin ◽  
E A Pecherskaya ◽  
Yu A Varenik ◽  
V V Antipenko ◽  
D V Artamonov ◽  
...  
Keyword(s):  
Measurement Error ◽  
Cardiovascular System ◽  
Phase Difference ◽  
Measurement Errors ◽  
Measurement Accuracy ◽  
Measuring Method ◽  
Automated System ◽  
Metrological Analysis ◽  
Basic Measurement ◽  
Human Cardiovascular System

Abstract The structure of an automated system for measuring the complex resistance of the human body and the phase difference is proposed. It is used in the rheographic method for diagnosing human cardiovascular system diseases using a multilevel microcontroller structure. The metrological analysis of the automated system made it possible to achieve an increase in the measurement accuracy both by reducing the methodological and instrumental components of measurement errors. The relative basic measurement error does not exceed ± 0.5%.

scholarly journals Tilt error in cryospheric surface radiation measurements at high latitudes: a model study

2015 ◽  
Vol 9 (4) ◽  
pp. 4355-4376 ◽  
Author(s):  
W. S. Bogren ◽  
J. F. Burkhart ◽  
A. Kylling
Keyword(s):  
Measurement Error ◽  
Solar Zenith Angle ◽  
Total Error ◽  
Surface Radiation ◽  
Model Study ◽  
Tilt Error ◽  
Total Measurement Error ◽  
Spectral Ranges ◽  
Radiation Measurements

Abstract. We have evaluated the magnitude and makeup of error in cryospheric radiation observations due to small sensor misalignment in in-situ measurements of solar irradiance. This error is examined through simulation of diffuse and direct irradiance arriving at a detector with a cosine-response foreoptic. Emphasis is placed on assessing total error over the solar shortwave spectrum from 250 to 4500 nm, as well as supporting investigation over other relevant shortwave spectral ranges. The total measurement error introduced by sensor tilt is dominated by the direct component. For a typical high latitude albedo measurement with a solar zenith angle of 60°, a sensor tilted by 1, 3, and 5° can respectively introduce up to 2.6, 7.7, and 12.8 % error into the measured irradiance and similar errors in the derived albedo. Depending on the daily range of solar azimuth and zenith angles, significant measurement error can persist also in integrated daily irradiance and albedo.

scholarly journals Components of Total Measurement Error for Hemoglobin A1c Determination

2001 ◽  
Vol 47 (10) ◽  
pp. 1851-1853 ◽  
Author(s):  
George Phillipov ◽  
Patrick J Phillips
Keyword(s):  
Measurement Error ◽  
Hemoglobin A1c ◽  
Total Measurement Error

scholarly journals Quasi - 3D and Full - 3D Approaches for Numerical Simulation in Axial Flow Hydraulic Turbine

2009 ◽  
Vol 4 ◽  
pp. 42-48
Author(s):  
Vishnu Prasad ◽  
K. S. Sayann ◽  
P Krishnamachar
Keyword(s):  
Viscous Flow ◽  
Flow Behavior ◽  
Flow Analysis ◽  
Axial Flow ◽  
Flow Simulation ◽  
Hydraulic Turbine ◽  
Energy And Environment ◽  
Improve Design ◽  
Numerical Flow Simulation ◽  
Experimental Values

Water passes through the rows of stationary and rotating blades in the turbine space and thus the flow becomes complex. The application of computational fluid dynamics (CFD) is steadily increasing to improve design of hydraulic turbines. The numerical flow simulation in the hydraulic turbine space can either be based on potential or viscous flow theory. In both the approaches, detailed flow behavior in complete turbine space is obtained. The quasi- 3D potential flow approach is quick and simple as compared to full-3D viscous flow methods of analysis but do not take into account the friction losses, which need to be computed separately. The direct flow analysis has been carried out in an experimentally tested model of axial flow hydraulic turbine using the two approaches and the comparison of flow pattern and computed parameters in runner is made in present paper. The computed efficiencies and other performance parameters have also been compared with experimental values at some critical points for validation.Hydro Nepal: Journal of Water, Energy and Environment Issue No. 4, January, 2009 Page 42-48

scholarly journals Excessive Additive Effect On Engine Oil Viscosity

2014 ◽  
Vol 62 (5) ◽  
pp. 1015-1020 ◽  
Author(s):  
Vojtěch Kumbár ◽  
Jiří Votava
Keyword(s):  
Mathematical Models ◽  
Dynamic Viscosity ◽  
Engine Oil ◽  
Coefficient Of Determination ◽  
Oil Viscosity ◽  
Automotive Engine ◽  
Used Engine Oil ◽  
Experimental Values ◽  
Rotary Viscometer ◽  
Exponential Fit

The main goal of this paper is excessive additive (for oil filling) effect on engine oil dynamic viscosity. Research is focused to commercially distribute automotive engine oil with viscosity class 15W–40 designed for vans. There were prepared blends of new and used engine oil without and with oil additive in specific ratio according manufacturer’s recommendations. Dynamic viscosity of blends with additive was compared with pure new and pure used engine oil. The temperature dependence dynamic viscosity of samples was evaluated by using rotary viscometer with standard spindle. Concern was that the oil additive can moves engine oil of several viscosity grades up. It is able to lead to failure in the engine. Mathematical models were used for fitting experimental values of dynamic viscosity. Exponential fit function was selected, which was very accurate because the coefficient of determination R2 achieved high values (0.98–0.99). These models are able to predict viscosity behaviour blends of engine oil and additive.

scholarly journals Oil additive and its effect

2013 ◽  
Vol 61 (3) ◽  
pp. 691-697 ◽  
Author(s):  
Vojtěch Kumbár ◽  
Petr Dostál
Keyword(s):  
Mathematical Model ◽  
Chemical Elements ◽  
Viscosity Index ◽  
Engine Oil ◽  
Engine Oils ◽  
Experimental Approaches ◽  
Experimental Values ◽  
Rotary Viscometer ◽  
Oil Particles

The aim of this paper are experimental approaches, selected for analysis of the engine oils and described above, are surely sufficient for the needs of presented research. The spectrometry was used for determination of presence of selected chemical elements and especially metals in oil. Particles monitoring was employed in order to describe the amount, type, and size of friction particles. The temperature dependence of dynamic viscosity was evaluated by use of rotary viscometer. In case of all three approaches it is advantageous to compare the measured values with the results received for unused engine oil of the same marking and viscosity index. If the degradation of oil is classified as low or medium, it is possible to increase its service life for several thousands of kilometers. Mathematical model (polynomial 6thdegree) it was used for fitting experimental values.

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