scholarly journals Maxwell Equations for Material Systems, Version 1

2020 ◽  
Author(s):  
Robert Eisenberg
Keyword(s):  
Maxwell Equations ◽  
Lorentz Invariance ◽  
Spatial Filter ◽  
Great Accuracy ◽  
Conservation Equation ◽  
Total Current ◽  
Equations Of Electrodynamics ◽  
Material Systems ◽  
Low Pass ◽  
The Right

The Maxwell equations of electrodynamics describe electrical and magnetic forces with great accuracy in the vacuum of space. But the equations of electrodynamics applied to material systems are usually written in a way that obscures their accuracy. The usual formulation of the Maxwell equations includes a dielectric constant as a single real number that grossly over-approximates the actual properties of matter, particularly liquid matter so important in applications of electrodynamics to biology and chemistry. We rewrite two Maxwell equations here to make clear the precision of the Maxwell equations in the presence or absence of matter. We discuss and derive two well known corollaries that are as universal and precise as the Maxwell equations themselves: (1) a continuity equation that relates charge and flux and (2) a conservation equation in which total current never accumulates at all. The total current is the right hand side of the Ampere-Maxwell law. Total current is perfectly incompressible. It is conserved exactly, everywhere and at every time, independent of the microphysics of charge conduction. The total current combines the flux of charges and the ethereal current. The ethereal current \varepsilon_{o\ }\sfrac{\partial\mathbf{E}}{\partial t}\ exists everywhere, including the interior of atoms, because it is a property of space, not matter. The ethereal current exists, and thus flows, in a vacuum devoid of mass. The ethereal current is a consequence of the relativistic (Lorentz) invariance of charge. Charge does not change even if it moves at speeds approaching the velocity of light. Total current has properties quite distinct from flux of mass because of the ethereal current. Most strikingly, in the one dimensional unbranched systems of electronic circuits and biological ion channels, the total current is independent of location, even if the flux of charges varies a great deal. Indeed, the Maxwell equations—and thus conservation of total current—act as a perfect low pass spatial filter, converting the infinite variation of (the Brownian model of) thermal motion of charges to the zero variation of the total current.

scholarly journals Maxwell Equations for Material Systems, Version 2

2020 ◽  
Author(s):  
Robert Eisenberg
Keyword(s):  
Maxwell Equations ◽  
Lorentz Invariance ◽  
Spatial Filter ◽  
Great Accuracy ◽  
Conservation Equation ◽  
Total Current ◽  
Equations Of Electrodynamics ◽  
Material Systems ◽  
Low Pass ◽  
The Right

The Maxwell equations of electrodynamics describe electrical and magnetic forces with great accuracy in the vacuum of space. But the equations of electrodynamics applied to material systems are usually written in a way that obscures their accuracy. The usual formulation of the Maxwell equations includes a dielectric constant as a single real number that grossly over-approximates the actual properties of matter, particularly liquid matter so important in applications of electrodynamics to biology and chemistry. We rewrite two Maxwell equations here to make clear the precision of the Maxwell equations in the presence or absence of matter. We discuss and derive two well known corollaries that are as universal and precise as the Maxwell equations themselves: (1) a continuity equation that relates charge and flux and (2) a conservation equation in which total current never accumulates at all. The total current is the right hand side of the Ampere-Maxwell law. Total current is perfectly incompressible. It is conserved exactly, everywhere and at every time, independent of the microphysics of charge conduction. The total current combines the flux of charges and the ethereal current. The ethereal current \varepsilon_{o\ }\sfrac{\partial\mathbf{E}}{\partial t}\ exists everywhere, including the interior of atoms, because it is a property of space, not matter. The ethereal current exists, and thus flows, in a vacuum devoid of mass. The ethereal current is a consequence of the relativistic (Lorentz) invariance of charge. Charge does not change even if it moves at speeds approaching the velocity of light. Total current has properties quite distinct from flux of mass because of the ethereal current. Most strikingly, in the one dimensional unbranched systems of electronic circuits and biological ion channels, the total current is independent of location, even if the flux of charges varies a great deal. Indeed, the Maxwell equations—and thus conservation of total current—act as a perfect low pass spatial filter, converting the infinite variation of (the Brownian model of) thermal motion of charges to the zero variation of the total current.

scholarly journals Thermostatics vs. Electrodynamics

2020 ◽  
Author(s):  
Robert S. Eisenberg
Keyword(s):  
Dielectric Constant ◽  
Boundary Conditions ◽  
Maxwell Equations ◽  
Displacement Current ◽  
Total Current ◽  
Thermal Dynamics ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Classical Formulation ◽  
Low Pass

Thermodynamics has been the foundation of many models of biological and technological systems. But thermodynamics is static and is misnamed. A more suitable name is thermostatics. Thermostatics does not include time as a variable and so has no velocity, flow or friction. Indeed, as usually formulated, thermostatics does not include boundary conditions. Devices require boundary conditions to define their input and output. They usually involve flow and friction. Thermostatics is an unsuitable foundation for understanding technological and biological devices. A time dependent generalization of thermostatics that might be called thermal dynamics is being developed by Chun Liu and collaborators to avoid these limitations. Electrodynamics is not restricted like thermostatics, but in its classical formulation involves drastic assumptions about polarization and an over-approximated dielectric constant. Once the Maxwell equations are rewritten without a dielectric constant, they are universal and exact. Conservation of total current, including displacement current, is a restatement of the Maxwell equations that leads to dramatic simplifications in the understanding of one dimensional systems, particularly those without branches, like the ion channel proteins of biological membranes and the two terminal devices of electronic systems. The Brownian fluctuations of concentrations and fluxes of ions become the spatially independent total current, because the displacement current acts as an unavoidable low pass filter, a consequence of the Maxwell equations for any material polarization. Electrodynamics and thermal dynamics together form a suitable foundation for models of technological and biological systems.

Predictors of risk in serious sex offenders

1997 ◽  
Vol 170 (S32) ◽  
pp. 17-21 ◽  
Author(s):  
Don Grubin
Keyword(s):  
Risk Assessment ◽  
Sex Offenders ◽  
Great Accuracy ◽  
High Rate ◽  
Common Belief ◽  
Sex Offending ◽  
Clinical Method ◽  
The Right

With the exception of a very few prolific offenders, sex offending is not a high rate activity. Even recidivist offenders will commit only a small number of offences in their careers, and these may be separated by intervals of years. Because of this, anyone setting out to predict reoffending by sex offenders will do best if they simply assume that none will reoffend, in which case they will be right more often than not. But such an approach, of course, would be criticised for being oversimplistic. Sex offenders have a history, and there is a common belief that if we know enough about an individual's past we should be able to predict his future with great accuracy. This has led some workers to claim that if the right variables can be discovered and plugged into a risk assessment algorithm, then the resulting desktop prediction of risk will outperform any competing clinical method.

Step-exchange strategy for balance control of a walking biped under a lateral impact

2014 ◽  
Vol 41 (5) ◽  
pp. 456-464
Author(s):  
Yeoun-Jae Kim ◽  
Joon-Yong Lee ◽  
Ju-Jang Lee
Keyword(s):  
External Force ◽  
Balance Control ◽  
Biped Robot ◽  
Conservation Equation ◽  
Hill Climbing ◽  
Lateral Impact ◽  
Content Type ◽  
Double Support ◽  
The Right ◽  
The Impact

Purpose – This paper aims to present a step-exchange strategy for balance control of a walking biped robot when a lateral impact acts suddenly. A step-out strategy has been recently proposed for balance control when an unknown lateral force acts to a biped robot during walking. This step-out strategy causes a robot to absorb the impact kinetic energy and efficiently maintain balance without falling down. Nevertheless, it was found that the previous strategies have drawbacks that the two foots should always be on the ground (double-support mode) after being balanced and the authors think it is difficult to continue walking after being balanced. Unlike the existing balance strategies, the proposed step-exchange strategy is to not only maintain balance but also to lift one leg in the air (single-support mode) after being balanced so that it is easy for a biped robot to keep walking after being balanced. Design/methodology/approach – In the proposed step-exchange strategy, forward Newton–Euler equation, angular momentum and energy conservation equation were derived. Hill-climbing algorithm is utilized for numerically finding a solution. To verify the proposed strategy, a biped robot by Open Dynamics Engine was stimulated, and experiments with a real biped robot (LRH-1) were also conducted. Findings – The proposed step-exchange strategy enables a walking biped robot under a lateral impact to keep balance and to keep a single-support mode after exchanging a leg. It is helpful for a biped robot to continue walking without any stop. It is found that the proposed step-exchange strategy can be applicable for maintaining balance even if a biped robot is moving. Even though this proposal seems immature yet, it is the first attempt to exchange the supporting foot itself. This strategy is very straightforward and intuitive because humans are also likely to exchange their supporting foot onto the opposite side when an unexpected force is acting. Research limitations/implications – The proposed step-exchange strategy described in this paper can be applicable in the situation when the external force is applied in the +Y direction, the left leg is the swing leg and the right leg is the stance leg, or it can also be applicable in the situation when the external force is applied in −Y direction, the right leg is the swing leg and the left leg is the stance leg (Figure 2 for ±Y force direction). If an impact force acts to the side of the swing leg, the other step-exchange strategy is needed. The authors are studying this issue as a future work. Originality/value – The authors have originated the proposed step-exchange strategy for balance control of a walking biped robot under lateral impact. The strategy is genuine and superior in comparison with the state-of-the-art strategy because not only can a biped robot be balanced but it can also easily continue walking by using the step-exchange strategy.

Time dependent backward piping erosion 2D modeling with laminar flow transport equations

2020 ◽  
Author(s):  
Juan Pablo Aguilar-Lopez ◽  
Manuel Wewer ◽  
Thom Bogaard ◽  
Matthijs Kok
Keyword(s):  
Sediment Transport ◽  
Coupled Model ◽  
Mass Conservation ◽  
Element Model ◽  
Great Accuracy ◽  
Conservation Equation ◽  
Empirical Formulas ◽  
Important Conclusion ◽  
Scale Experiment ◽  
Piping Erosion

<p>Backward piping erosion (BEP) is a highly complex erosive process which occurs on granular soils when large head differences are exerted. This process represents a significant threat to dams and levees stability and therefore a large part of the design and reliability assessment of these water retaining structures is devoted to this single process. Several authors have achieved great accuracy in predicting the critical head difference that triggers the process but not so much has been studied regarding the time of occurrence and the duration of the erosive process.  In the present study we propose a 2D finite element model for which not only the critical head difference can be predicted but also the development of the erosive process in time. This was achieved by coupling the 2D Darcy partial differential equation with Exner’s 1D sediment transport mass conservation equation. Different laminar sediment transport rate empirical models were tested and used as inputs in the coupled model. To test the performance of the proposed model, the IJkdijk real scale experiment for piping erosion was simulated. The results show that the model is capable of predicting not only the critical head and its progression in time but also specific events of the process such as the instants of start of the erosion and the  complete seepage length development . An important conclusion of the study is that from several transport empirical formulas tested, the model from Yalin which is widely recognized by the sediment transport community performs the best.</p>

Exact solutions of the Einstein–Maxwell equations with linear equation of state

2012 ◽  
Vol 90 (12) ◽  
pp. 1179-1183 ◽  
Author(s):  
Tooba Feroze
Keyword(s):  
Equation Of State ◽  
Linear Equation ◽  
Maxwell Equations ◽  
Momentum Conservation ◽  
Conservation Equation ◽  
Fluid Distribution ◽  
Spherically Symmetric ◽  
Field Equations ◽  
General Linear Equation ◽  
Energy Momentum Conservation

Two new classes of solutions of the Einstein–Maxwell field equations are obtained by substituting a general linear equation of state into the energy–momentum conservation equation. We have considered static, anisotropic, and spherically symmetric charged perfect fluid distribution of matter with a particular form of gravitational potential. Expressions for the mass–radius ratio, the surface, and the central red shift horizons are given for these solutions.

FIRST-ORDER FILTERS GENERALIZED TO THE FRACTIONAL DOMAIN

2008 ◽  
Vol 17 (01) ◽  
pp. 55-66 ◽  
Author(s):  
A. G. RADWAN ◽  
A. M. SOLIMAN ◽  
A. S. ELWAKIL
Keyword(s):  
Fractional Order ◽  
Pass Band ◽  
Integer Order ◽  
Continuous Time Filters ◽  
Passive Filters ◽  
Low Pass ◽  
Band Pass ◽  
Half Power ◽  
The Right ◽  
High Pass

Traditional continuous-time filters are of integer order. However, using fractional calculus, filters may also be represented by the more general fractional-order differential equations in which case integer-order filters are only a tight subset of fractional-order filters. In this work, we show that low-pass, high-pass, band-pass, and all-pass filters can be realized with circuits incorporating a single fractance device. We derive expressions for the pole frequencies, the quality factor, the right-phase frequencies, and the half-power frequencies. Examples of fractional passive filters supported by numerical and PSpice simulations are given.

scholarly journals Ketepatan Pemorsian Sayur Terhadap Standar Porsi Makanan Biasa

2019 ◽  
Vol 4 (2) ◽  
pp. 97
Author(s):  
Sabrina Apriliyani ◽  
Luh Suranadi ◽  
Susilo Wirawan ◽  
AASP Chandradewi
Keyword(s):  
Observational Study ◽  
Sampling Method ◽  
Fruits And Vegetables ◽  
Research Result ◽  
Fruit Body ◽  
Great Accuracy ◽  
Advantages And Disadvantages ◽  
Optimal Health ◽  
The Right ◽  
Hospital Research

Background. Consumption of vegetables and fruit body needs for vitamins, minerals and fiber in achieving a healthy diet as recommended by guidelines of balanced nutrition for optimal health. Most vitamins and minerals found in fruits and vegetables has a function as an antioxidant that may reduce the incidence of non-communicable diseases related to nutrition, as a result of the excess or deficiency. Large portions often becomes very important when serving food, especially in the food pemortion advantages and disadvantages still occur because no portion of the right size in pemortion food. Pemortion these foods should be according to the standard portion that has been set by the installation of a hospital nutrition. Huge portions, will directly influence the nutrients contained in a food. Purpose Knowing picture vegetable pemortion accuracy of the standards usual food servings at lunch in Tabanan Hospital. Research Methods. This research is an observational study. The study was conducted on 22 to 30 March 2019 in BRSUD Tabanan. The data were taken using accidental sampling method. Samples taken care third grade. Research Result. Large servings of vegetables at lunch for ordinary food in hospitals Tabanan as follows: vegetable tamarind 160.7 grams, vegetable nodes 175 grams, vegetable ointment 170.4 grams, vegetable bobor 131.8 grams, vegetables, tamarind 177 grams, vegetable soup 104.5 grams, vegetable lodeh 102.6 grams and 71.4 grams of vegetable ointment. Power pemortion obtained are four power pemortion with vocational education and universities. Conclusion. Great accuracy servings of vegetables served by 4 workers pemortion average is not appropriate because more than a standard portion

scholarly journals Low-pass spatial filter based on 3D metamaterial rasorber with wideband absorption at high frequency

AIP Advances ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 055018
Author(s):  
X. Q. Jia ◽  
Q. Chen ◽  
Q. An ◽  
Y. J. Zheng ◽  
Y. Q. Fu
Keyword(s):  
High Frequency ◽  
Spatial Filter ◽  
Low Pass

Extraction of Blood Vessels in Retina

2018 ◽  
Vol 11 (4) ◽  
pp. 122-136
Author(s):  
Thamer Mitib Al Sariera ◽  
Lalitha Rangarajan
Keyword(s):  
Blood Vessels ◽  
Spatial Filter ◽  
Vascular Tree ◽  
Retinal Blood Vessels ◽  
Tracking Process ◽  
Low Pass ◽  
Novel Method ◽  
Local Window ◽  
Spatial Locations ◽  
Optimum Direction

This article presents a novel method to extract retinal vascular tree automatically. The proposed method consists of four steps; smoothing image using low pass spatial filter to reduce spurious noise in the image; extracting candidate borders of the vessels based on a local window property; tracking process, starting with a candidate pixel and following in the optimum direction with monitoring the connectivity of the vessel twin border; constructing the whole tree of retinal blood vessels by connecting the vessel segments based on their spatial locations, widths and directions. The algorithm was trained with 20 images from the DRIVE dataset, and tested using the remaining 20 images.

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