scholarly journals Physics for Surgeons - Part 4: Energy Devices in Surgery

2020 ◽  
Vol 9 (1) ◽  
pp. 122-131
Author(s):  
Darakhshan Qaiser ◽  
Piyush Ranjan ◽  
Kamal Kataria ◽  
Anita Dhar ◽  
Anurag Srivastava
Keyword(s):  
Electric Current ◽  
Hybrid Systems ◽  
Electric Energy ◽  
Laser Ultrasonic ◽  
Operation Theatre ◽  
Operation Room ◽  
Energy Devices ◽  
The Past ◽  
Argon Beam Coagulator ◽  
Physical Principles

Modern surgery has advanced astoundingly in the last century owing to the advent of number of energy devices in the operation room. Surgeon in the past were only using electric current –monopolar diathermy to burn and couterize the tissue, the present day surgeons are equiped with a number of more advanced energy devices e.g. LASER, ultrasonic vibrating shears, radiofrequency, shockwaves, argon beam coagulator and advanced bipolar electric energy with hybrid systems and light energy of different wavelengths. In the present paper, we have explained the physical principles involved in the commonly used energy devices in the operation theatre.

scholarly journals Hydrodynamic constraints on the energy efficiency of droplet electricity generators

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Antoine Riaud ◽  
Cui Wang ◽  
Jia Zhou ◽  
Wanghuai Xu ◽  
Zuankai Wang
Keyword(s):  
Energy Efficiency ◽  
Kinetic Energy ◽  
Total Energy ◽  
Viscous Dissipation ◽  
Shear Force ◽  
Mechanical Energy ◽  
Electric Energy ◽  
The Past ◽  
Viscous Shear ◽  
Impingement Velocity

AbstractElectric energy generation from falling droplets has seen a hundred-fold rise in efficiency over the past few years. However, even these newest devices can only extract a small portion of the droplet energy. In this paper, we theoretically investigate the contributions of hydrodynamic and electric losses in limiting the efficiency of droplet electricity generators (DEG). We restrict our analysis to cases where the droplet contacts the electrode at maximum spread, which was observed to maximize the DEG efficiency. Herein, the electro-mechanical energy conversion occurs during the recoil that immediately follows droplet impact. We then identify three limits on existing droplet electric generators: (i) the impingement velocity is limited in order to maintain the droplet integrity; (ii) much of droplet mechanical energy is squandered in overcoming viscous shear force with the substrate; (iii) insufficient electrical charge of the substrate. Of all these effects, we found that up to 83% of the total energy available was lost by viscous dissipation during spreading. Minimizing this loss by using cascaded DEG devices to reduce the droplet kinetic energy may increase future devices efficiency beyond 10%.

Biological Phase Separation and Biomolecular Condensates in Plants

2021 ◽  
Vol 72 (1) ◽  
Author(s):  
Ryan J. Emenecker ◽  
Alex S. Holehouse ◽  
Lucia C. Strader
Keyword(s):  
Phase Separation ◽  
Cell Biology ◽  
Condensed Matter ◽  
Annual Review ◽  
Publication Date ◽  
Nuclear Speckles ◽  
The Past ◽  
Shared Property ◽  
And Function ◽  
Physical Principles

A surge in research focused on understanding the physical principles governing the formation, properties, and function of membraneless compartments has occurred over the past decade. Compartments such as the nucleolus, stress granules, and nuclear speckles have been designated as biomolecular condensates to describe their shared property of spatially concentrating biomolecules. Although this research has historically been carried out in animal and fungal systems, recent work has begun to explore whether these same principles are relevant in plants. Effectively understanding and studying biomolecular condensates require interdisciplinary expertise that spans cell biology, biochemistry, and condensed matter physics and biophysics. As such, some involved concepts may be unfamiliar to any given individual. This review focuses on introducing concepts essential to the study of biomolecular condensates and phase separation for biologists seeking to carry out research in this area and further examines aspects of biomolecular condensates that are relevant to plant systems. Expected final online publication date for the Annual Review of Plant Biology, Volume 72 is May 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Part 2 Specific Issues of Arbitration in Brazil, 22 Electric Energy Arbitration

2020 ◽  
Author(s):  
Grion Renato Stephan
Keyword(s):  
Complex System ◽  
South America ◽  
Electric Energy ◽  
Electricity Sector ◽  
Generation System ◽  
Current Structure ◽  
Social Growth ◽  
Electric Sector ◽  
The Past ◽  
Different Levels

This concluding chapter examines electric energy arbitration in Brazil. An appropriately developed electric sector is a key element for any country's economic and social growth. It requires an adequate volume of investment, either domestic or foreign, in order to meet the regularly increasing needs of all stakeholders involved in such market, including the population. Brazil's electricity sector is the largest in South America and plays an important role in the country's economy. Moreover, Brazil has its own and well-functioning electricity generation system. To keep up with the development and needs of such a system, the Brazilian legal and regulatory framework has undergone through important changes over the past 25 years or so. A well-established and complex set of rules and regulations is now in place; in this context, arbitration has been steadily introduced as an alternative method to resolve the disputes arising in that sector. The chapter then provides an overview of the electric energy market in Brazil, with some historical milestones and details on the steps taken for its modernization, as well as its current structure. It also analyses how arbitration has now become an important part of this complex system, in which a variety of actors operate at different levels.

scholarly journals Review of Neural Networks in the EEG Signal Recognition

2020 ◽  
Author(s):  
Ildar Rakhmatulin
Keyword(s):  
Neural Networks ◽  
Signal Processing ◽  
Processing Technique ◽  
Eeg Signal ◽  
Signal Recognition ◽  
Signal Processing Technique ◽  
Comprehensive Overview ◽  
The Past ◽  
Eeg Signal Processing ◽  
Physical Principles

In the last decade, unprecedented progress in the development of neural networks influenced dozens of different industries, among which are signal processing for the electroencephalography process (EEG). Electroencephalography, even though it appeared in the first half of the 20th century, to this day didn’t change the physical principles of operation. But the signal processing technique due to the use of neural networks progressed significantly in this area. Evidence for this can serve that for the past 5 years more than 1000 publications on the topic of using machine learning have been published in popular libraries. Many different models of neural networks complicate the process of understanding the real situation in this area. In this manuscript, we provided the most comprehensive overview of research where were used neural networks for EEG signal processing.

scholarly journals Using Electric Current as a Weed Control Method

2017 ◽  
Vol 2 (6) ◽  
pp. 59
Author(s):  
Hasan Sahin ◽  
Mehmet Yalınkılıc
Keyword(s):  
Electric Current ◽  
Control Method ◽  
Electric Energy ◽  
Electric Circuit ◽  
The Body ◽  
Vital Activity ◽  
Negative Effects ◽  
Short Term ◽  
Chemical Methods ◽  
Important Place

Weed struggle has an important place in agricultural production. The widespread use of chemicals in this struggle is due to its easy applicability, its short-term results, and its economic efficiency. However, the negative effects of these chemicals on the environment and human health have been recognized, and the interest in non-chemical struggle methods has also increased. One of the non-chemical methods of struggle is using electric energy. In this work, which is carried out by passing the electric current through the plant, it is aimed that ended the vital activity of weed (cress), as a result of electric current flowing through it. The experimental setup prepared for use in operation consists of a voltage regulator with 1-300 V steps and copper conductors which will contact the plants. In the experiments, weed seeds germinated under suitable conditions were placed on the board to complete the electric circuit and the circuit was completed by passing current through the plants that the copper conductor tips contacted. As a result of the experiments, plants were observed to lose their vitality about 70% when 100 volts of electricity was applied over the body for 300, 420 and 540 seconds. On the other hand, when electric energy was applied as 200 volts and 300 volts for 300, 420, and 540 seconds, respectively, the vital activity of the plants close to 100% was ended.

scholarly journals Four Subjects in Solar Physics from the Point of View of the Electric Current Approach

2020 ◽  
pp. 33-45
Author(s):  
Syun-Ichi Akasofu
Keyword(s):  
Solar Wind ◽  
Electric Current ◽  
Solar Flares ◽  
Solar Physics ◽  
Current Approach ◽  
Point Of View ◽  
Coronal Temperature ◽  
The Past ◽  
Electromagnetic Processes ◽  
Difficult Subjects

Four major subjects in solar physics, the heating of the corona, the cause of the solar wind, the formation of sunspots and the cause of solar flares, are discussed on the basis of the electric current approach, a sequence of processes consisting of power supply(dynamo), transmission (currents/circuits) and dissipation(high coronal temperature, solar wind, sunspots and solar flares).This is because the four subjects have hardly been considered in terms of the electric current approach in the past, in spite of the fact that these subjects are various manifestations of electromagnetic processes. It is shown that this approach provides a new systematic way of considering each subject; (1) the long-standing issue of the coronal temperature, (2)the long-standing problem on the cause of the solar wind, (3)the presence of single spots(forgotten or dismissed in the past) and its relation to unipolar magnetic regions and (4) the crucial power/energy source and subsequent explosive processes of solar flares. The four subjects are obviously extremely complicated and difficult subjects, but it is hoped that the electric current approach might provide a new insight in considering the four subjects.

scholarly journals From amplitudes to contact cosmological correlators

2021 ◽  
Vol 2021 (10) ◽  
Author(s):  
James Bonifacio ◽  
Enrico Pajer ◽  
Dong-Gang Wang
Keyword(s):  
Commutative Algebra ◽  
Point Contact ◽  
De Sitter ◽  
Reconstruction Formula ◽  
The Past ◽  
Sitter Spacetime ◽  
General Scalar ◽  
General Physical ◽  
Lorentz Boosts ◽  
Physical Principles

Abstract Our understanding of quantum correlators in cosmological spacetimes, including those that we can observe in cosmological surveys, has improved qualitatively in the past few years. Now we know many constraints that these objects must satisfy as consequences of general physical principles, such as symmetries, unitarity and locality. Using this new understanding, we derive the most general scalar four-point correlator, i.e., the trispectrum, to all orders in derivatives for manifestly local contact interactions. To obtain this result we use techniques from commutative algebra to write down all possible scalar four-particle amplitudes without assuming invariance under Lorentz boosts. We then input these amplitudes into a contact reconstruction formula that generates a contact cosmological correlator in de Sitter spacetime from a contact scalar or graviton amplitude. We also show how the same procedure can be used to derive higher-point contact cosmological correlators. Our results further extend the reach of the boostless cosmological bootstrap and build a new connection between flat and curved spacetime physics.

Electrochemical neutralization energy: from concept to devices

2021 ◽  
Author(s):  
Yichun Ding ◽  
Pingwei Cai ◽  
Zhenhai Wen
Keyword(s):  
Energy Conversion ◽  
High Performance ◽  
Electric Energy ◽  
Chemical Energy ◽  
Energy Devices ◽  
Promising Strategy ◽  
Electrochemical Energy

Electrochemical neutralization energy establishes a bridge for facilitating energy conversion between some chemical energy and electric energy, shedding light on a promising strategy to develop high-performance aqueous electrochemical energy devices.

scholarly journals Nanocouplers for Infrared and Visible Light

2012 ◽  
Vol 2012 ◽  
pp. 1-17 ◽  
Author(s):  
A. Andryieuski ◽  
A. V. Lavrinenko
Keyword(s):  
Visible Light ◽  
Waveguide Section ◽  
Practical Applications ◽  
Essential Component ◽  
The Past ◽  
Plasmonic Structures ◽  
Tapered Waveguide ◽  
Physical Principles

An efficient and compact coupler—a device that matches a microwaveguide and a nanowaveguide—is an essential component for practical applications of nanophotonic systems. The number of coupling approaches has been rapidly increasing in the past ten years with the help of plasmonic structures and metamaterials. In this paper we overview recent as well as common solutions for nanocoupling. More specifically we consider the physical principles of operation of the devices based on a tapered waveguide section, a direct coupler, a lens, and a scatterer and support them with a number of examples.

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