Emission of Electromagnetic Radiation by the Impact of Positive Ions of Hydrogen on Metal Surfaces

1956 ◽  
Vol 104 (5) ◽  
pp. 1492-1493 ◽  
Author(s):  
Rafi M. Chaudhri ◽  
Mustafa Yar Khan ◽  
Abdul Latif Taseer
Keyword(s):  
Electromagnetic Radiation ◽  
Metal Surfaces ◽  
Positive Ions ◽  
The Impact

The theory of the extraction of electrons from metals by metastable atoms, II

1931 ◽  
Vol 27 (3) ◽  
pp. 460-468 ◽  
Author(s):  
H. S. W. Massey
Keyword(s):  
Hydrogen Atom ◽  
Velocity Distribution ◽  
Spherical Cavity ◽  
Metal Surfaces ◽  
Excited Atoms ◽  
Positive Ions ◽  
Order Of Magnitude ◽  
The Impact

In a previous paper the nature of the phenomena occurring when electrons are ejected from metal surfaces by the impact of metastable atoms and positive ions was discussed. It was shown that electrons may be ejected by excited atoms at considerable distances from the surface, and by considering the case of an excited hydrogen atom at the centre of a spherical cavity in the metal the order of magnitude of the effects to be expected and the velocity distribution of the ejected electrons was determined. In this paper the theory will be extended in two directions.

Emission of Soft Electromagnetic Radiation from Metals by the Impact of High-Energy Protons and Positive Ions

Nature ◽  
1961 ◽  
Vol 189 (4769) ◽  
pp. 996-997 ◽  
Author(s):  
RAFI MOHAMMED CHAUDHRI ◽  
MUSTAF YAR KHAN
Keyword(s):  
Electromagnetic Radiation ◽  
High Energy ◽  
Positive Ions ◽  
The Impact

The Effective Temperature of Dust Impact Plasmas — Olivine Dust on Tungsten Target

2021 ◽  
Author(s):  
Jiří Pavlů ◽  
Samuel Kočiščák ◽  
Åshild Fredriksen ◽  
Michael DeLuca ◽  
Zoltan Sternovsky
Keyword(s):  
Negative Charge ◽  
Negative Ions ◽  
Charge Carriers ◽  
Dust Particles ◽  
Applied Bias ◽  
Control Grid ◽  
Impact Speed ◽  
Positive Ions ◽  
Effective Temperatures ◽  
The Impact

<p>We experimentally observe both positive and negative charge carriers in impact plasma and estimate their effective temperatures. The measurements are carried on a dust accelerator using polypyrrole (PPy)-coated olivine dust particles impacting tungsten (W) target in the velocity range of 2–18 km/s. We measure the retained impact charge as a function of applied bias potential to the control grid. The temperatures are estimated from the data fit. The estimated effective temperatures of the positive ions are approximately 7 eV and seems to be independent of the impact speed. The negative charge carriers' temperatures vary from as low as 1 eV for the lowest speeds to almost ten times higher speeds. The presented values differ significantly from previous studies using Fe dust particles. Yet, the discrepancy can be attributed to a larger fraction of negative ions in the impact plasma that likely originates from the PPy coating.</p>

The characteristic spectral lines of target atoms in the impact of40Ar q+ ions on metal surfaces

2004 ◽  
Vol 47 (6) ◽  
pp. 729-736
Author(s):  
Xiao’an Zhang ◽  
Yongtao Zhao ◽  
Fuli Li ◽  
Zhihu Yang ◽  
Guoqing Xiao ◽  
...  
Keyword(s):  
Metal Surfaces ◽  
Spectral Lines ◽  
The Impact

scholarly journals Hygienic assessment of the impact of 5G/IMT-2020 communication networks on public health (literature review)

2021 ◽  
Vol 100 (9) ◽  
pp. 929-932
Author(s):  
Anna M. Egorova ◽  
Lydiya A. Lutsenko ◽  
Anna V. Sukhova ◽  
Vyacheslav V. Kolyuka ◽  
Rustam V. Turdyev
Keyword(s):  
Public Health ◽  
Radio Frequency ◽  
Electromagnetic Radiation ◽  
Communication Networks ◽  
Biological Effects ◽  
Three Dimensional ◽  
Cochrane Library ◽  
Pubmed Search ◽  
The Cochrane Library ◽  
The Impact

The program “Digital Economy of the Russian Federation” approved the Concept for the creation and development of 5G / IMT-2020 networks. The development of 5G communications will significantly impact the implementation of many innovative projects and initiatives: the Smart City project, Unmanned Transport, etc. Along with significant technical advantages compared to previous generations of communication (2G, 3G, 4G), 5G technology has completely different emitting characteristics: more emitting elements, signal modulation, three-dimensional beam, the ability to control the beam, SHF (ultra-high) and EHF (extremely high) radio frequency ranges and centimetre and millimetre wavelengths of electromagnetic radiation. Therefore, it is becoming an especially urgent problem to ensure exposure to the human body of non-ionizing electromagnetic fields of the radio frequency range (30 kHz-300 GHz). The authors searched the literature on the biological effects of 5G cellular communications and electromagnetic radiation in the centimetre and millimetre ranges using the appropriate keywords in PubMed search engines, Scopus, Web of Science, Medline, The Cochrane Library, EMBASE, Global Health, CyberLeninka, RSCI and others. There is currently tentative and conflicting evidence on the impact of 5G. The rapidly growing density of wireless devices and antennas (considering future 5G networks) increases the public health risk from exposure to RF EMFs as the penetration depth for 5G EHF radiation is only a few millimetres. At these wavelengths, resonance phenomena are possible at the cellular and molecular levels, particularly concerning stimulating SHF and EHF oxidative processes and damaging DNA. The influence of the millimetre range of RF-EMF is poorly understood; oncological and non-oncological (impact on the reproductive, immune systems, etc.) effects are possible. Using numerical simulation methods of EMF radiation resonances on insects, Thielens A et al., 2018, found a significant overall increase in the absorbed RF power at a frequency of 6 GHz and higher than a frequency below 6 GHz.

scholarly journals Electromagnetic Pollution as a Possible Explanation for the Decline of House Sparrows in Interaction with Other Factors

Birds ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 329-337
Author(s):  
Alfonso Balmori
Keyword(s):  
Electromagnetic Radiation ◽  
Thermal Effects ◽  
House Sparrow ◽  
Bird Species ◽  
Passer Domesticus ◽  
The Other ◽  
Rapid Decline ◽  
House Sparrows ◽  
Electromagnetic Pollution ◽  
The Impact

In recent decades, there has been a decline of the House Sparrow (Passer domesticus), mainly in European cities, and several hypotheses have been proposed that attempt to determine the causes of this rapid decline. Previous studies indicated that house sparrows were significantly negatively associated with increasing electromagnetic radiation and sparrows disappeared from areas most polluted. In addition, there are many studies on the impact of radiation on other bird and non-bird species, as well as numerous laboratory studies that demonstrated detrimental effects at electric field strength levels that can be found in cities today. Electromagnetic radiation is the most plausible factor for multiple reasons, including that this is the only one that affects the other hypotheses proposed so far. It is a type of pollution that affects productivity, fertility, decreases insects (chicken feed), causes loss of habitat, decreases immunity and can promote disease. Additionally, the recent sparrow decline matches the deployment of mobile telephony networks. Further, there are known mechanisms of action for non-thermal effects of electromagnetic radiation that may affect sparrows causing their decline. Thus, electromagnetic radiation must be seriously considered as a factor for house sparrows’ decline, probably in synergy with the other factors previously proposed.

scholarly journals Dynamic Mechanical Properties of Oxide Films Formed on Metallic Surfaces as Measured Using a Tribological Approach at High Temperature

2011 ◽  
Vol 2011 ◽  
pp. 1-12
Author(s):  
Yoshinori Isomoto Oka ◽  
Toshinori Tsumura
Keyword(s):  
High Temperature ◽  
Metal Surfaces ◽  
Oxide Films ◽  
Dynamic Mechanical Properties ◽  
Material Surface ◽  
Metallic Surfaces ◽  
Adhesive Properties ◽  
Mechanical Removal ◽  
Barrier Coating ◽  
The Impact

The surface degradation of metals in boiler tubes and turbines in high-temperature corrosive environments causes severe problems in fuel combustion power plant systems. High-temperature resistant materials have been recently developed using a thermal barrier coating (TBC) and high-chromium alloys. Oxide films or coatings formed on metal surfaces at high temperatures can sometimes decrease the corrosion rate. However, the damage to the material is often accelerated by the mechanical removal of corrosion products from the material surface. It is therefore very important to investigate the mechanical and adhesive properties of the oxide films or coatings on metal surfaces used in high-temperature environments. This paper introduces a tribological method that uses a single spherical projectile impact at high temperature to measure the mechanical and adhesive properties of oxide films formed on various metal surfaces. Impact tests were performed on the surfaces of oxide films after their growth in a high-temperature furnace, and the deformed or fractured surfaces were observed in order to measure the mechanical and adhesive properties. The mechanical and adhesive properties of an elastic modulus, fracture, and exfoliation stresses were measured using the impact method, and the results depended on the type of metal oxide films and on the high-temperature environment.

scholarly journals An investigation of the effects of electron collisions with platinum and with hydrogen, to ascertain whether the production of ionisation from platinum is due to occluded hydrogen

1920 ◽  
Vol 97 (681) ◽  
pp. 23-43 ◽  
Keyword(s):  
Metal Surface ◽  
Metal Surfaces ◽  
Direct Proof ◽  
Ionisation Potential ◽  
Electron Collisions ◽  
Electron Stream ◽  
Positive Ions ◽  
Minimum Velocity ◽  
Positively Charged ◽  
Made In

In the course of an investigation of the effects of electron collisions with helium atoms, it was found that positive ions were produced from a positively charged platinum gauze when this was bombarded by electrons with a minimum velocity of about 11 volts. The production of positive ions in this way does not appear to have been observed before for such small velocities of the impacting electrons, though their detection with primary rays of 30 volts speed is recorded by Campbell in the account of his experiments on ionisation by charged particles. In this paper Campbell gives an excellent summary of the work which has been done in connection with the bombardment of metal surfaces by slow cathode rays. The work of Lenard, Baeyer, Gehrts, Campbell, and others has established the facts that, when such rays fall on a negatively charged metal surface, electrons leave the surface, and that the number and the speed of these electrons depends on the velocity of impact of the primary stream. When the velocity of the incident rays is less than 11 volts, the electrons leaving the plate are those of the primary stream which have been reflected at the metal surface, the characteristic of these reflected rays being that most of them have a velocity comparable with that of the incident rays. When the velocity of impact reaches 11 volts, in addition to reflexion, an excitation of secondary rays begins and gradually increases in amount as the speed is further increased up to about 200 volts. On this account the curve showing the relation between the velocity of impact and the number of electrons leaving the plate takes an upward turn at 11 volts, but no other bend occurs until 200 volts is reached. It has therefore been concluded that the two processes mentioned above, viz., reflexion, and excitation of secondary rays beginning at 11 volts, are the only causes of electrons leaving the impacted surface. It was found by Baeyer that with a minimum velocity of impact of about 25 volts more electrons leave the plate than fall on it, and this result, combined with the fact that Campbell detected a positive current (presumably from a positively charged plate) when the bombarding electrons had a minimum velocity of 30 volts, has given rise to the view that the second process—that which is operative above 11 volts—is an ionisation at the metal surface, the material ionised being either the metal itself or gas attached to it. On this view it is concluded that the critical velocity of 11 volts is the “ionisation potential ” of the material ionised. This velocity was found to be the same for all the metal surfaces tested, and as it agreed with the usually accepted value of the “ionisation potential” for hydrogen, it has been suggested that the material ionised is hydrogen present in the surface of the metal. Some confirmation of this view has been obtained by Campbell from experiments with metal surfaces subjected to treatment designed to modify the amount of hydrogen present, but the evidence hitherto produced cannot be said to prove conclusively that the process which begins at 11 volts is a genuine ionisation by electron collisions. That ionisation occurs ultimately can hardly be doubted, for it has been observed that when the velocity of the electron stream is sufficiently increased, the number of electrons leaving a bombarded electrode is in some cases as much as twenty times as great as the number arriving at it, but the first direct proof that ionisation occurs at the metal surface when the impacting electrons have a velocity as small as 11 volts seems to be that given by the experiments made in the course of our investigation of the ionisation of helium. The present research is a fuller investigation of this effect, undertaken in order to ascertain whether the evidence of ionisation at 11 volts could be substantiated, and, if so, to determine whether it should be attributed to the metal itself or to hydrogen attached to the metal surface.

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