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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Electrodeless Discharge of Isopropyl Alcohol

Bryant, Franklin Delano 08 1900 (has links)
Gases at satisfactory pressures fluoresce in the presence of radio frequency radiation (6). Such fluorescent gases have been used to probe fields of radio frequency oscillation and their emission spectra have been recorded and studied. Ions with multiple charges also exist in these gases, (6). In 1941 Oliver (12) observed the fluorescence of an isobutane- isobutene gaseous mix flowing to a pump through a glass tube which was wrapped by a spiral antenna of a sevenmegacycle transmitter. A white deposit was noticed at a bend in the tubing on the pump side of the fluorescing section of the gas (12, p. 8). In 1957 Blacknall (3) studied the fluorescence and reaction products of propylene in the antenna region of sevenmega- cycle radiation, The oscillator employed by Blacknall was an ARC-5/T-22 military surplus transmitter of range 7.00 to 9.10 megacycles, which he operated at 7.00 megacycles. Blacknall observed a drop in pressure and the formation of a brown deposit in the region of the coil. Blacknall did not report an analysis of this product. In 1959 Armstrong (1) repeated Blacknall's experiments and modified Blacknall's apparatus into an improved design. He also performed an analysis on Blacknall's product. Blacknall used a vertical open-end mercurial manometer with which to measure pressure in his system and as a result introduced mercury vapor into his system. Armstrong tried to minimize the amount of mercury introduced by covering his manometric mercury with a layer of octyl sebacate, "octoil". Armstrong used a spiral-would antenna wrapped around his reaction vessel and reported the formation of spiral brown rings coincident with the copper wire of the antenna. There was a white product deposited in a spiral interlaced with the spiral of dark brown material. No definite identification was reported by Armstrong other than reporting, his solid material as isotactic polypropylene. Other work on electrodeless discharge of organic chemicals has been done in 1960 by Durward Smith and William Smith (13), in 1961 by Jimmie McCarty (10), and in 1963-64 by David Flinn (4).
2

Atmospheric effects on radio frequency (RF) wave propagation in a humid, near-surface environment

Mason, Sammuel P. January 2010 (has links) (PDF)
Thesis (M.S. in Meteorology)--Naval Postgraduate School, March 2010. / Thesis Advisor(s): Guest, Peter S. ; Goroch, Andreas K. "March 2010." Author(s) subject terms: Electromagnetic propagation, electromagnetic scattering, groundwave propagation, mathematical techniques, variance reduction. Includes bibliographical references (p. 67-68). Also available in print.
3

Spontaneous movements of hands in gradients of weak VHF electromagnetic fields

Huttunen, P. (Paavo) 21 February 2012 (has links)
Abstract The aims of the present study were to clarify the antenna function and radio frequency radiation (RFR) sensitivity of human subjects using theoretical calculations and field tests. The weak very high frequency (VHF) electromagnetic fields and spontaneous hand movements were recorded. Groups of university students, other volunteers and as a very interesting group, experienced well finders, were used as test subjects. The VHF field was studied using a spectrum analyser and tuneable narrow-band or broad-band meter with a dipole antenna. The hand movements were registered by potentiometric systems and electromyography (EMG). The test subjects (altogether n = 140) in different tests were walking, sitting in a cart being pulled slowly forward, or sitting in a moving car. The responses were observed and hand movements were recorded and analysed by personal computers. By visual inspection and using the Pearson's correlation, the results of different individuals have been compared with the measured intensity of far fields of a radio mast. Reaction spots and graphs defined by different individuals in the same experiment areas have been compared to each other. Hand movement correlated with the reactions of the forearm and shoulder muscles, e.g., pronator teres and trapezius, by EMG measurements. The reactions of some persons correlated with each other. Experiments in a slow moving wagon and in a moving car showed a correlation between the test subjects’ hand movements and the intensity of below 1 mV/m radio and TV signals measured in the vicinity of the test subject. In open field tests different persons usually reacted in widely different ways. The most evident results were recorded near the buildings, where the radio waves reflected from the wall and patterns of standing waves were clear. Many VHF frequency modulated (FM) broadcasting signals were summed at these places at the same time. It is concluded that the spontaneous hand movement reactions occurred as a response of the human body to the gradients of the VHF field intensity. The reaction generally occurred in interference patterns of multipath propagation or standing waves originating from the radiation of FM radio and TV broadcasting transmitters and radiation reflected from the walls of buildings or from other objects. This non-thermal reaction was clearly observable as spontaneous arm movements by 39 percent of the 85 tested students. / Tiivistelmä Tässä tutkimuksessa selvitettiin ihmisen herkkyyttä radiotaajuiselle säteilylle. Ihmisen toimimista radioaaltojen antennina tarkasteltiin teoreettisesti ja kenttäkokein. Heikkojen VHF-alueen radioaaltojen voimakkuutta ja tahattomia käsien liikkeitä rekisteröitiin valituilla koepoluilla. Koehenkilöinä on ollut yliopiston opiskelijoita ja muita vapaaehtoisten ryhmiä. Kiinnostavin ryhmä oli kokeneet kaivonkatsojat, joiden käsienliikereaktioihin radioaaltojen vaikutuksista löytyy viitteitä kirjallisuudesta. Radioaaltojen voimakkuuden vaihteluja mitattiin spektrianalysaattorilla ja laajakaistaisella VHF-alueen integroivalla mittarilla. Käsien liikkeitä rekisteröitiin potentiometriin perustuvilla liikeantureilla. Lihasten sähköimpulsseja rekisteröitiin elektromyografia- eli EMG-laitteella. Eri koesarjoissa koehenkilöt (yhteensä 140) kävelivät, istuivat hitaasti vedettävässä vaunussa tai istuivat liikkuvassa autossa. Reaktioita tarkkailtiin ja käsien liikkeet ja mitatut kentänvoimakkuudet rekisteröitiin ja analysoitiin tietokoneella. Eri koehenkilöiden tuloksia, reagointipaikkoja ja rekisteröityjä käyriä 5–35 km:n etäisyydellä mastoista tarkasteltiin silmämääräisesti. Pearsonin korrelaatiolaskentaa apuna käyttäen tuloksia verrattiin radiomastojen säteilyn voimakkuuteen. Eri ihmisten reagointikohtia ja käyriä samoilta koealueilta vertailtiin keskenään. Koeasetelmassa käsienliikkeiden todettiin korreloivan joidenkin kyynärvarren ja hartialihasten (mm. pronator teres ja trapezius) EMG-signaaleihin. Joidenkin koehenkilöiden tulokset korreloivat keskenään. Hitaasti vedettävässä vaunussa ja liikkuvassa autossa tehdyissä kokeissa tuli esille korrelaatio vartalon edessä olevien käsien loittonemis-lähestymis-liikkeiden ja koehenkilön välittömässä läheisyydessä mitattujen 1 mV/m -tasoisten radio- ja TV-signaalien voimakkuusvaihtelujen välillä. Avoimella kentällä henkilöt reagoivat hyvin eri tavoin. Parhaiten yhteys tuli esille rakennusten lähellä sijaitsevilla koealueilla, joissa radioaallot heijastuivat rakennuksen seinästä muodostaen selkeitä seisovan aallon kuvioita. Useat taajuusmoduloidut VHF-alueen radiosignaalit summautuivat näissä paikoissa samanaikaisesti. Johtopäätöksenä on, että tahattomat käsienliikkeet tapahtuvat kehon vasteena VHF-kentän voimakkuuden muutoksille. Reaktio tapahtui yleensä interferenssi-kuvioissa tai seisovissa aalloissa, jotka muodostuvat FM-radio- ja TV-lähetysten monitie-etenemisestä radioaaltojen heijastuessa rakennusten seinistä tai muista kohteista. Tämä ei-lämpövaikutustason reaktio oli selvästi havaittavissa olkapään tasalle koukistetun käden tahattomana ojennus-koukistus-liikkeenä 39 prosentilla testatuista 85 opiskelijasta.

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