About the Maximum Transfer of Power in Time-Varying Linear Circuits

2012 ◽  
Vol 629 ◽  
pp. 894-899
Author(s):  
M. de la Sen ◽  
S. Alonso-Quesada ◽  
A.J. Garrido ◽  
A. Ibeas

This paper discusses the mathematical conditions of achievement of maximum power transfer from source to load in electric circuits where their basic elements (resistance, inductance and capacitance) are eventually linear and time-varying but not necessarily everywhere time-differentiable. This last concern is seen to be relevant for the inductive part of the circuit whose time- derivative, where it exists, plays the role of a resistor while it has an impulsive characterization at time instants where such a time-derivative does not exist. The power transfer degradation through time is also characterized related to the initial values of the circuitry provided that the source remains unaltered through time.

2014 ◽  
Vol 9 (2) ◽  
pp. 213-232
Author(s):  
Anne E. Fernald

The taxicab operated as a crucial transitional mode of transport for bourgeois women, allowing them maximum power as spectators when it was still brave for a woman to be a pedestrian. The writings of Virginia Woolf, which so often depict bourgeois women coping with modernity, form the chief context in which to explore the role of the taxicab in liberating the modern woman. The taxi itself, clumsy and ungendered, encases a woman's body and protects her from the male gaze. At the same time, a woman in a taxi can look out upon the street or freely ignore it. As such, the taxi is a type of heterotopia: a real place but one which functions outside of and in a critical relation to, the norms of the rest of the community.


2019 ◽  
pp. 78-83
Author(s):  
Irene-Teodora Nica

The study is aimed at training and developing balance through Pilates programs. In order to improve the initial values, we have developed a set of corresponding exercises. The test was applied on a target group, the initial and final results being presented. The conclusion presents the interpretation of the results.


2021 ◽  
Vol 13 (9) ◽  
pp. 4898
Author(s):  
Andrzej Tucki ◽  
Korneliusz Pylak

Regional inequalities are a major concern for governments and policymakers. There is no doubt that tourism impacts the reduction of inequalities, but this impact is not entirely clear. We consider this ambiguity to be related to both the level of study and type of accommodation. In the present study, we examine the inequality level measured by the Gini coefficient in 108 municipalities of the peripheral region of northeastern Poland from 2009 to 2018. We employ a directional spillover index to measure the impact of two accommodation types on tax incomes per capita. The empirical results indicate that collective accommodation-based tourism only reduced inequality during the financial crisis, while individual accommodation-based tourism started to reduce inequality from 2014, when Russian sanctions hit local agriculture and businesses. These results indicate that the role of accommodation types is time-varying and evident in measuring economic distress during and after shocks.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Martin L. Pall

Abstract Millimeter wave (MM-wave) electromagnetic fields (EMFs) are predicted to not produce penetrating effects in the body. The electric but not magnetic part of MM-EMFs are almost completely absorbed within the outer 1 mm of the body. Rodents are reported to have penetrating MM-wave impacts on the brain, the myocardium, liver, kidney and bone marrow. MM-waves produce electromagnetic sensitivity-like changes in rodent, frog and skate tissues. In humans, MM-waves have penetrating effects including impacts on the brain, producing EEG changes and other neurological/neuropsychiatric changes, increases in apparent electromagnetic hypersensitivity and produce changes on ulcers and cardiac activity. This review focuses on several issues required to understand penetrating effects of MM-waves and microwaves: 1. Electronically generated EMFs are coherent, producing much higher electrical and magnetic forces then do natural incoherent EMFs. 2. The fixed relationship between electrical and magnetic fields found in EMFs in a vacuum or highly permeable medium such as air, predicted by Maxwell’s equations, breaks down in other materials. Specifically, MM-wave electrical fields are almost completely absorbed in the outer 1 mm of the body due to the high dielectric constant of biological aqueous phases. However, the magnetic fields are very highly penetrating. 3. Time-varying magnetic fields have central roles in producing highly penetrating effects. The primary mechanism of EMF action is voltage-gated calcium channel (VGCC) activation with the EMFs acting via their forces on the voltage sensor, rather than by depolarization of the plasma membrane. Two distinct mechanisms, an indirect and a direct mechanism, are consistent with and predicted by the physics, to explain penetrating MM-wave VGCC activation via the voltage sensor. Time-varying coherent magnetic fields, as predicted by the Maxwell–Faraday version of Faraday’s law of induction, can put forces on ions dissolved in aqueous phases deep within the body, regenerating coherent electric fields which activate the VGCC voltage sensor. In addition, time-varying magnetic fields can directly put forces on the 20 charges in the VGCC voltage sensor. There are three very important findings here which are rarely recognized in the EMF scientific literature: coherence of electronically generated EMFs; the key role of time-varying magnetic fields in generating highly penetrating effects; the key role of both modulating and pure EMF pulses in greatly increasing very short term high level time-variation of magnetic and electric fields. It is probable that genuine safety guidelines must keep nanosecond timescale-variation of coherent electric and magnetic fields below some maximum level in order to produce genuine safety. These findings have important implications with regard to 5G radiation.


2016 ◽  
Vol 8 (1) ◽  
pp. 57-82 ◽  
Author(s):  
Francesc Dilmé ◽  
Fei Li

We study the role of dropout risk in dynamic signaling. A seller privately knows the quality of an indivisible good and decides when to trade. In each period, he may draw a dropout shock that forces him to trade immediately. To avoid costly delay, the seller with a low-quality good voluntarily pools with early dropouts, implying that the expected quality of the good increases over time. We characterize the time-varying equilibrium trading dynamics. It is demonstrated that the maximum equilibrium delay of trade is decreasing in the initial belief that the good is of high quality. (JEL C73, D82, D83)


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