Phenomenon of Turbulent Macro-Instabilities in Agitated Systems

1995 ◽  
Vol 60 (1) ◽  
pp. 85-94 ◽  
Author(s):  
Oldřich Brůha ◽  
Ivan Fořt ◽  
Pavel Smolka
Keyword(s):  
Physical Parameters ◽  
Measuring Device ◽  
Newtonian Liquids ◽  
Electronic Recorder

Turbulent macro-instabilities in the process of mixing in cylindrical baffled vessel provided with pitched blade impeller were studied. Rules of macro-instability occurrence were investigated in their dependence on physical parameters of three Newtonian liquids mixed and on the regime of mixing. The observations were realized partly visually, partly by means of a specially designed mechanical measuring device connected with an electronic recorder indicating the manifestations of instability in the liquid.

scholarly journals Predicting Compression Pressure of Knitted Fabric Using a Modified Laplace’s Law

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4461
Author(s):  
Yetanawork Teyeme ◽  
Benny Malengier ◽  
Tamrat Tesfaye ◽  
Simona Vasile ◽  
Wolelaw Endalew ◽  
...  
Keyword(s):  
Physical Parameters ◽  
Interface Pressure ◽  
Compression Pressure ◽  
Engineering Strain ◽  
Measuring Device ◽  
Laplace’S Law ◽  
The Difference ◽  
Experimental Pressure ◽  
Laplace's Law

The aim of this study is to develop a mathematical model for the prediction of compression pressure based on fabric parameters, such as engineering stress, engineering strain and engineering modulus of elasticity. Four knitted compression fabrics with different fibrous compositions and knit structures were used. Rectangular-cut strips were employed for the force–elongation characterization of the fabrics. The experimental pressure values between the fabric and rigid cylinder were assessed using a Picopress pressure measuring device. The mechanical and physical parameters of the fabric that influence the interface pressure, such as strain, elasticity modulus/stress and thickness, were determined and integrated into Laplace’s law. A good correlation was observed between the experimental and calculated pressure values for all combinations of fabrics, mounted with variable tension on the cylinder. Over the considered range of pressures, the difference between the two datasets was generally less than 0.5 mmHg. The effect of washing after five, ten and fifteen washing cycles on the fabric–cylinder interface pressure was found to be significant.

scholarly journals Sistem Alat Ukur Kekeruhan Berbasis Mikrokontroler ATMega16A-PU

2019 ◽  
Vol 1 (1) ◽  
pp. 112
Author(s):  
Muhammad Mispu Ariadi ◽  
Iwan Sugriwan ◽  
Arfan Eko Fahrudin
Keyword(s):  
Personal Computer ◽  
Small Error ◽  
Measuring System ◽  
Physical Parameters ◽  
Measuring Device ◽  
Data Measurement ◽  
Quality Of Water ◽  
Sensor Module ◽  
Voltage Signal

The fabrication of the ATMega16A-PU microcontroller-based the system turbidity sensor consists of sensor module Turbidity SKU:SEN0189 including with the signal conditioning, power supply unit, the ATMega16A-PU microcontroller  module, LCD 16 x 2 character, and personal computer (PC). The measuring system is used to measure the quality of water on theriverMartapura South Kalimantan, Indonesia. The physical parameters that measured is the of water. The measuring of turbidity detected by the sensor through the light that traverse the suspended particles in water. The output signal from the sensor in from of the voltage signal is connectedwith ATMega16A-PU microcontroller viaport A0. The voltage signal output is inversely proportional to the turbidity. Theequation of sensor characteristic is obtained by comparing the measuring device with HACH DR 890 Colorimeter turbid meter gauge. The characteristic equation obtained is counted into five equations to get a small error value, where v1 = -0.0036k1 + 4.0834, v2 = -0.0024k2 + 3.9351, v3 = -0.003k3 + 4.1777, v4 = -0.0033k4 + 4.3355, v5 = -0.0034k5 + 4.4315, the five equations have different measurement ranges. The result of data measurement are displayed on the LCD 16 x 2 character and the personal computer (PC) with the Delphi.7 interface program. The advantages of personal computer (PC) interface are the data measurement result could monitor and stroge in excel and database format. The results of the measuring instrument show a difference of 1 NTU to 15 NTU with the largest deviation is ± 28.7 and a standard deviation of ± 4.57 in the range of 31 NTU to 510 NTU

scholarly journals Broadband Spectral Induced Polarization for the detection of Permafrost and an approach to ice content estimation – A Case study from Yakutia, Russia

2021 ◽  
Author(s):  
Jan Mudler ◽  
Andreas Hördt ◽  
Dennis Kreith ◽  
Kirill Bazhin ◽  
Lyudmila Lebedeva ◽  
...  
Keyword(s):  
Induced Polarization ◽  
Parameter Distribution ◽  
Physical Parameters ◽  
Frequency Range ◽  
Field Scale ◽  
Frequency Dependent ◽  
Multidimensional Distribution ◽  
Measuring Device ◽  
Spectral Induced Polarization ◽  
Ice Content

Abstract. The reliable detection of subsurface ice using non-destructive geophysical methods is an important objective in permafrost research. Furthermore, the ice content of the frozen ground is an essential parameter for further interpretation, for example in terms of risk analysis, e.g. for the description of permafrost carbon feedback by thawing processes. The High-Frequency Induced Polarization method (HFIP) enables the measurement of the frequency dependent electrical signal of the subsurface. In contrast to the well-established Electrical Resistivity Tomography (ERT), the usage of the full spectral information provides additional physical parameters of the ground. As the electrical properties of ice exhibit a strong characteristic behaviour in the frequency range between 100 Hz and 100 kHz, HFIP is in principle suitable to estimate ice content. Here, we present methodological advancements of the HFIP method and suggest an explicit procedure for ice content estimation. A new measuring device, the Chameleon-II (Radic Research), was used for the first time. It was designed for the application of Spectral Induced Polarization over a wide frequency range and is usable under challenging conditions, for example in field sites under periglacial influence and the presence of permafrost. Amongst other improvements, compared to a previous generation, the new system is equipped with longer cables and larger power, such that we can now achieve larger penetration depths up to 10 m. Moreover, it is equipped with technology to reduce electromagnetic coupling effects which can distort the desired subsurface signal. The second development is a method to estimate ice content quantitatively from five Cole-Cole parameters obtained from spectral two-dimensional inversion results. The method is based on a description of the subsurface as a mixture of two components (matrix and ice) and uses a previously suggested relationship between frequency-dependent electrical permittivity and ice content. Measurements on a permafrost site near Yakutsk, Russia, were carried out to test the entire procedure under real conditions at the field scale. We demonstrate that the spectral signal of ice can clearly be identified even in the raw data, and show that the spectral 2-D inversion algorithm is suitable to obtain the multidimensional distribution of electrical parameters. The parameter distribution and the estimated ice content agree reasonably well with previous knowledge of the field site from borehole and geophysical investigations. We conclude that the method is able to provide quantitative ice content estimates, and that relationships that have been tested in the laboratory may be applied at the field scale.

Weak Measurements in Nano-optics

2020 ◽  
Vol 5 (3) ◽  
pp. 191-213
Author(s):  
Niladri Modak ◽  
Ankit K. Singh ◽  
Shyamal Guchhait ◽  
Athira BS ◽  
Mandira Pal ◽  
...  
Keyword(s):  
High Precision ◽  
Spectral Response ◽  
Weak Measurement ◽  
Optical Systems ◽  
Physical Parameters ◽  
Weak Measurements ◽  
Temporal Shift ◽  
Measuring Device ◽  
Weak Value ◽  
Weak Value Amplification

Background: Weak measurement involves weak coupling between the system and the measuring device (pointer) enables large amplification and high precision measurement of small physical parameters. The outcome of this special measurement procedure involving nearly mutually orthogonal pre- and post-selection of states in such weakly interacting systems leads to weak value that can become exceedingly large and lie outside the eigenvalue spectrum of the measured observable. This unprecedented ability of weak value amplification of small physical parameters has been successfully exploited for various metrological applications in the optical domain and beyond. Even though it is a quantum mechanical concept, it can be understood using the classical electromagnetic theory of light and thus can be realized in classical optics. Objective: Here, we briefly review the basic concepts of weak measurement and weak value amplification, provide illustrative examples of its implementation in various optical domains. The applications involve measuring ultra-sensitive beam deflections, high precision measurements of angular rotation, phase shift, temporal shift, frequency shift and so forth, and expand this extraordinary concept in the domain of nano-optics and plasmonics. Methods: In order to perform weak value amplification, we have used Gaussian beam and spectral response as the pointer subsequently. The polarization state associated with the pointer is used as pre and post-selection device. Results: We reveal the weak value amplification of sub-wavelength optical effects namely the Goos-Hänchen shift and the spin hall shift. Further, we demonstrate weak measurements using spectral line shape of resonance as a natural pointer, enabling weak value amplification beyond the conventional limit, demonstrating natural weak value amplification in plasmonic Fano resonances and so forth. The discussed concepts could have useful implications in various nano-optical systems to amplify tiny signals or effects. Conclusion: The emerging prospects of weak value amplification towards the development of novel optical weak measurement devices for metrological applications are extensively discussed.

scholarly journals Parametric Study of Injection Rates With Solenoid Injectors in an Injection Quantity and Rate Measuring Device

2014 ◽  
Author(s):  
Stephen Busch ◽  
Paul C. Miles
Keyword(s):  
Single Injection ◽  
Injection Rate ◽  
Physical Parameters ◽  
Fuel Injector ◽  
Mixture Formation ◽  
Measuring Device ◽  
Multiple Injections ◽  
Injection Quantity ◽  
Main Injection ◽  
Injection Rates

The rate at which fuel is injected into the cylinder of a direct injection Diesel engine has significant implications for the ensuing mixture formation and combustion processes. Advances in fuel injector technology enable a variety of advanced injection strategies, particularly very closely coupled injection events. In this work, a Moehwald HDA injection quantity and rate measuring unit is used to investigate the injection rates obtained with a pre-production solenoid injector with a fast acting, pressure-balanced control valve using a blend of n-hexadecane and heptamethylnonane (DPRF58). The effects of digital signal filtering on the rate shape and injected mass are investigated for a single injection. Additionally, the effects of physical parameters such as fuel and measurement chamber temperature, axial clamping force on the injector, high pressure line length, and solenoid current pull up time on the rate shape are investigated. The primary purpose of these simple parameter variations is to establish whether or not they have an impact on the measured injection rate traces and/or total measured injected masses. At each dwell time, the rates of injection are compared between the three injectors tested. These results show that these pre-production injectors can operate with very short dwell times while the injection rate curves indicate distinct pilot and main injection events and an influence of dwell on the rate shape of the main injection. Testing with PRF, a blend of n-heptane and isooctane, shows that while rates of injection are comparable to those obtained with the DPRF for a single injection, they are dramatically different for multiple injections. This has significant implications for the optical diagnostic techniques that may be employed to study the effects of multiple injections on the mixture formation process.

Some Results of the Spectroscopic Study of Four Close Binary Systems of Early Spectral Types

1965 ◽  
Vol 5 ◽  
pp. 120-130
Author(s):  
T. S. Galkina
Keyword(s):  
Spectroscopic Study ◽  
Spectral Type ◽  
Spectroscopic Investigation ◽  
Binary Systems ◽  
Quantitative Information ◽  
Close Binary ◽  
Physical Parameters ◽  
Absorption And Emission ◽  
Close Binary Systems ◽  
Quantitative Estimates

It is necessary to have quantitative estimates of the intensity of lines (both absorption and emission) to obtain the physical parameters of the atmosphere of components.Some years ago at the Crimean observatory we began the spectroscopic investigation of close binary systems of the early spectral type with components WR, Of, O, B to try and obtain more quantitative information from the study of the spectra of the components.

A theory of contamination in electron microscopes by surface diffusion

1978 ◽  
Vol 36 (1) ◽  
pp. 116-117
Author(s):  
J.T. Fourie
Keyword(s):  
Electron Beam ◽  
Surface Diffusion ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Physical Parameters ◽  
Carbon Compounds ◽  
Hydrocarbon Molecules ◽  
Electron Microscopes ◽  
Primary Electrons ◽  
Long Chain

Contamination in electron microscopes can be a serious problem in STEM or in situations where a number of high resolution micrographs are required of the same area in TEM. In modern instruments the environment around the specimen can be made free of the hydrocarbon molecules, which are responsible for contamination, by means of either ultra-high vacuum or cryo-pumping techniques. However, these techniques are not effective against hydrocarbon molecules adsorbed on the specimen surface before or during its introduction into the microscope. The present paper is concerned with a theory of how certain physical parameters can influence the surface diffusion of these adsorbed molecules into the electron beam where they are deposited in the form of long chain carbon compounds by interaction with the primary electrons.

Electron Microscopy in the Study of Natural Phytoplankton Assemblages

1985 ◽  
Vol 43 ◽  
pp. 620-623
Author(s):  
Linda Sicko-Goad
Keyword(s):  
Electron Microscopy ◽  
Aquatic Environment ◽  
Size Range ◽  
Physical Parameters ◽  
Specific Information ◽  
Phytoplankton Assemblages ◽  
Phytoplankton Productivity ◽  
Ecosystem Effects ◽  
Time Of Year ◽  
Species Specific

Although the use of electron microscopy and its varied methodologies is not usually associated with ecological studies, the types of species specific information that can be generated by these techniques are often quite useful in predicting long-term ecosystem effects. The utility of these techniques is especially apparent when one considers both the size range of particles found in the aquatic environment and the complexity of the phytoplankton assemblages.The size range and character of organisms found in the aquatic environment are dependent upon a variety of physical parameters that include sampling depth, location, and time of year. In the winter months, all the Laurentian Great Lakes are uniformly mixed and homothermous in the range of 1.1 to 1.7°C. During this time phytoplankton productivity is quite low.

A New Numerical Model for Electron-Probe Analysis at High Depth Resolution

1996 ◽  
Vol 54 ◽  
pp. 490-491
Author(s):  
P.-F. Staub ◽  
C. Bonnelle ◽  
F. Vergand ◽  
P. Jonnard
Keyword(s):  
Electron Probe ◽  
Surface Segregation ◽  
Depth Distribution ◽  
Computing Time ◽  
Depth Resolution ◽  
Physical Parameters ◽  
Electron Probe Analysis ◽  
Interface Phases ◽  
Excitation Conditions ◽  
High Depth

Characterizing dimensionally and chemically nanometric structures such as surface segregation or interface phases can be performed efficiently using electron probe (EP) techniques at very low excitation conditions, i.e. using small incident energies (0.5<E0<5 keV) and low incident overvoltages (1<U0<1.7). In such extreme conditions, classical analytical EP models are generally pushed to their validity limits in terms of accuracy and physical consistency, and Monte-Carlo simulations are not convenient solutions as routine tools, because of their cost in computing time. In this context, we have developed an intermediate procedure, called IntriX, in which the ionization depth distributions Φ(ρz) are numerically reconstructed by integration of basic macroscopic physical parameters describing the electron beam/matter interaction, all of them being available under pre-established analytical forms. IntriX’s procedure consists in dividing the ionization depth distribution into three separate contributions:

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