Dynamics of Current, Charge and Mass

Electricity plays a special role in our lives and life. Equations of electron dynamics are nearly exact and apply from nuclear particles to stars. These Maxwell equations include a special term the displacement current (of vacuum). Displacement current allows electrical signals to propagate through space. Displacement current guarantees that current is exactly conserved from inside atoms to between stars, as long as current is defined as Maxwell did, as the entire source of the curl of the magnetic field. We show how the Bohm formulation of quantum mechanics allows easy definition of current. We show how conservation of current can be derived without mention of the polarization or dielectric properties of matter. Matter does not behave the way physicists of the 1800's thought it does with a single dielectric constant, a real positive number independent of everything. Charge moves in enormously complicated ways that cannot be described in that way, when studied on time scales important today for electronic technology and molecular biology. Life occurs in ionic solutions in which charge moves in response to forces not mentioned or described in the Maxwell equations, like convection and diffusion. Classical derivations of conservation of current involve classical treatments of dielectrics and polarization in nearly every textbook. Because real dielectrics do not behave in a classical way, classical derivations of conservation of current are often distrusted or even ignored. We show that current is conserved exactly in any material no matter how complex the dielectric, polarization or conduction currents are. We believe models, simulations, and computations should conserve current on all scales, as accurately as possible, because physics conserves current that way. We believe models will be much more successful if they conserve current at every level of resolution, the way physics does.Comment: Version 4 slight reformattin

Development of a sensor for the continuous measurement of oil concentration in a refrigeration system

Shortcomings in the present standard method of determining the circulating oil concentration in a refrigeration system have led to the current research, wherein a continuous, in-line method of measuring the flowing oil concentration is sought;A literature survey and preliminary property measurements examined properties of oil-refrigerant mixtures that could be measured to infer the oil concentration in the liquid line of a refrigeration system. Four measurement methods were selected for development into oil concentration sensors: a vibrating U-tube densimeter, a new type of in-line viscometer, a prototype acoustic velocity probe, and an optical fiber refractometer;A flow loop capable of simulating a wide variety of liquid-line conditions was constructed for the testing and calibration of the oil concentration sensors. Performance tests of the densimeter, viscometer, and acoustic velocity sensor were conducted over an oil concentration range of 0 to 30 weight-percent for 150 SUS naphthenic oil/R-12, 150 SUS naphthenic oil/R-22, and 150 SUS alkylbenzene oil/R-502 mixtures. The temperatures in the flow loop test section during the performance tests were varied from 70 to 120 F and the pressure was maintained to provide approximately 3 F subcooling. Performance testing of the refractometer was not completed because of severe probe temperature sensitivity and poor repeatability;The performance test results were statistically analyzed to determine the oil concentration measurement uncertainty. The three sensors tested were found to attain the desired ±1 weight-percent uncertainty under a variety of conditions. Application guidelines are presented for the use of the densimeter, viscometer, and acoustic velocity as oil concentration sensors

Design and Operation of a Microwave Flow Cytometer for Single Cell Detection and Identification

Microwave dielectric sensing has become a popular technique in biological cell sensing for its potential in online, label-free, and real-time sensing. At microwave frequencies probing signals are sensitive to intracellular properties since they are able to penetrate cell membranes, making microwave flow cytometry a promising technology for label-free biosensing. In this dissertation a microwave flow cytometer is designed and used to measure single biological cells and micro particles. A radio frequency (RF)/microwave interferometer serves as the measurement system for its high sensitivity and tunability and we show that a two-stage interferometer can achieve up to 20 times higher sensitivity than a single interferometer. A microstrip sensor with an etched microfluidic channel is used as the sensing structure for measuring single cells and particles in flow. The microwave flow cytometer was used to measure changes in complex permittivity, , of viable and nonviable Saccharomyces cerevisiae and Saccharomyces pastorianus yeast cells and changes in complex permittivity and impedance of two lifecycle stages of Trypanosoma brucei, a unicellular eukaryotic parasite found in sub-Saharan Africa, at multiple frequencies from 265 MHz to 7.65 GHz. Yeast cell measurements showed that there are frequency dependent permittivity differences between yeast species as well as viability states. Quadratic discriminate analysis (QDA) and k-nearest neighbors (KNN) were employed to validate the ability to classify yeast species and viability, with minimum cross-validation error of with cross validation errors of 19% and 15% at 2.38 GHz and 265 MHz, respectively. Measurements of changes in permittivity and impedance of single procyclic form (PCF) and bloodstream form (BSF) T. brucei parasites also showed frequency dependence. The two cell forms had a strong dependence on the imaginary part of permittivity at 2.38 GHz and below and a strong dependence on the real part of permittivity at 5.55 GHz and above. Three PCF cell lines were tested to verify that the differences between the two cell forms were independent of cell strain. QDA gave maximum cross-validation errors of 15.4% and 10% when using one and three PCF strains, respectively. Impedance measurements were used to improve cell classification in cases where the permittivity of a cell cannot be detected. Lastly, a microwave resistance temperature detector (RTD) is designed, and a model is developed to extract the temperature and complex permittivity of liquids in a microfluidic channel. The microwave RTD is capable of measuring temperature to within 0.1°C. The design can easily be modified to increase sensitivity be lengthening the sensing electrode or modified for smaller volumes of solute by shortening the electrode

High temperature supercapacitors

The scientific objective of this research program was to determine the feasibility of manufacturing an ionic liquid-based supercapacitor that could operate at temperatures up to 220 °C. A secondary objective was to determine the compatibility of ionic liquids with other cell components (e.g. current collectors) at high temperature and, if required, consider means of mitigating any problems. The industrial motivation for the present work was to develop a supercapacitor capable of working in the harsh environment of deep offshore boreholes. If successful, this technology would allow down-hole telemetry under conditions of mechanical vibration and high temperature. The obstacles, however, were many. All supercapacitor components had to be stable against thermal decomposition up to T ≥ 220 °C. Volatile components had to be eliminated. If possible, the finished device should be able to withstand voltages greater than 4 V, in order to maximise the amount of stored energy. The internal resistance should be as low as possible. Side reactions, particularly faradaic reactions, should be eliminated or suppressed. All liquid components should be gelled to minimise leakage in the event of cell damage. Finally, any emergent problems should be identified. [Continues.

Dynamics of Current, Charge and Mass

abstract: Electricity plays a special role in our lives and life. The dynamics of electrons allow light to flow through a vacuum. The equations of electron dynamics are nearly exact and apply from nuclear particles to stars. These Maxwell equations include a special term, the displacement current (of a vacuum). The displacement current allows electrical signals to propagate through space. Displacement current guarantees that current is exactly conserved from inside atoms to between stars, as long as current is defined as the entire source of the curl of the magnetic field, as Maxwell did.We show that the Bohm formulation of quantum mechanics allows the easy definition of the total current, and its conservation, without the dificulties implicit in the orthodox quantum theory. The orthodox theory neglects the reality of magnitudes, like the currents, during times that they are not being explicitly measured.We show how conservation of current can be derived without mention of the polarization or dielectric properties of matter. We point out that displacement current is handled correctly in electrical engineering by ‘stray capacitances’, although it is rarely discussed explicitly. Matter does not behave as physicists of the 1800’s thought it did. They could only measure on a time scale of seconds and tried to explain dielectric properties and polarization with a single dielectric constant, a real positive number independent of everything. Matter and thus charge moves in enormously complicated ways that cannot be described by a single dielectric constant,when studied on time scales important today for electronic technology and molecular biology. When classical theories could not explain complex charge movements, constants in equations were allowed to vary in solutions of those equations, in a way not justified by mathematics, with predictable consequences. Life occurs in ionic solutions where charge is moved by forces not mentioned or described in the Maxwell equations, like convection and diffusion. These movements and forces produce crucial currents that cannot be described as classical conduction or classical polarization. Derivations of conservation of current involve oversimplified treatments of dielectrics and polarization in nearly every textbook. Because real dielectrics do not behave in that simple way-not even approximately-classical derivations of conservation of current are often distrusted or even ignored. We show that current is conserved inside atoms. We show that current is conserved exactly in any material no matter how complex are the properties of dielectric, polarization, or conduction currents. Electricity has a special role because conservation of current is a universal law.Most models of chemical reactions do not conserve current and need to be changed to do so. On the macroscopic scale of life, conservation of current necessarily links far spread boundaries to each other, correlating inputs and outputs, and thereby creating devices.We suspect that correlations created by displacement current link all scales and allow atoms to control the machines and organisms of life. Conservation of current has a special role in our lives and life, as well as in physics. We believe models, simulations, and computations should conserve current on all scales, as accurately as possible, because physics conserves current that way. We believe models will be much more successful if they conserve current at every level of resolution, the way physics does.We surely need successful models as we try to control macroscopic functions by atomic interventions, in technology, life, and medicine. Maxwell’s displacement current lets us see stars. We hope it will help us see how atoms control life.View the article as published at https://www.degruyter.com/view/j/mlbmb.2017.5.issue-1/mlbmb-2017-0006/mlbmb-2017-0006.xm