WorldWideScience

Sample records for microwave radiation emitted

  1. Measurements of nonionizing radiation emitted from microwave oven

    International Nuclear Information System (INIS)

    Elnour, Yassir Elnour Osman

    2014-05-01

    There is an increase in the usage of microwave oven which is used electromagnetic radiation in the microwave range, which believed to be harmful to human health. The measurements were taken at distance of range(0-100) cm from the microwave oven. The study concluded that the risk possibility of the radiation increases at high mode. We measured the power density, magnetic field and signal strength of microwave oven using the SPECTRAN high frequency (HF-6080) detector. The experimental results of power density were found to be (3.78-208000) nW/m 2 and magnetic field is (0.001-0.744) mA/m. These values are less than the exposure limits recommended. (author)

  2. Radiation emitting devices regulations

    International Nuclear Information System (INIS)

    1970-01-01

    The Radiation Emitting Devices Regulations are the regulations referred to in the Radiation Emitting Devices Act and relate to the operation of devices. They include standards of design and construction, standards of functioning, warning symbol specifications in addition to information relating to the seizure and detention of machines failing to comply with the regulations. The radiation emitting devices consist of the following: television receivers, extra-oral dental x-ray equipment, microwave ovens, baggage inspection x-ray devices, demonstration--type gas discharge devices, photofluorographic x-ray equipment, laser scanners, demonstration lasers, low energy electron microscopes, high intensity mercury vapour discharge lamps, sunlamps, diagnostic x-ray equipment, ultrasound therapy devices, x-ray diffraction equipment, cabinet x-ray equipment and therapeutic x-ray equipment

  3. Safety assessment of RF and microwave radiation emitted by the mobile telephone base station (MTBS) in Malaysia: experience and challenge

    International Nuclear Information System (INIS)

    Roha Tukimin; Rozaimah Abd Rahim; Mohamad Amirul Nizam; Mohd Yusof Mohd Ali

    2007-01-01

    Non-ionising radiation (NIR) is known to be hazardous if the amount received is excessive. It is a fact that NIR, including extremely low frequency (ELF) electromagnetic fields, radiofrequency (RF) and microwave radiation can be found almost everywhere generated by both natural and man-made source. This is due to increase in demand for telecommunication and wireless technology which is become very important and as part of our lives. However, the widespread of the relevant technology contributed more NIR man-made sources exposure to the human. Due to public concern their potential of causing such health hazard, members of public and companies approached and request NIR Group of Nuclear Malaysia to carry out surveys and safety assessments of radiofrequency and microwave radiation emitted by the mobile telephone base station (MTBS) erected near the residential area or installed on the rooftop of the commercial building. Objective of the survey was to assess the presence of radiofrequency and microwave radiation and to identify radiation level which may lead to significant personnel exposure. Findings of the survey was compared to the standard guidelines issued by Malaysian Communication and Multimedia Commission (MCMC) and International Committee on Non-Ionising Radiation Protection (ICNIRP). This paper highlights the works that had been carried out by NIR Group of Nuclear Malaysia from 1997 to 2007. We will share the experience and challenge in carried out the NIR safety assessment at mobile telephone base station. Results of the assessment work will be used to develop non-ionising radiation database for future reference in Malaysia. (Author)

  4. Assessment of radiofrequency/microwave radiation emitted by the antennas of rooftop-mounted mobile phone base stations

    International Nuclear Information System (INIS)

    Keow, M. A.; Radiman, S.

    2006-01-01

    Radiofrequency (RF) and microwave (MW) radiation exposures from the antennas of rooftop-mounted mobile telephone base stations have become a serious issue in recent years due to the rapidly evolving technologies in wireless telecommunication systems. In Malaysia, thousands of mobile telephone base stations have been erected all over the country, most of which are mounted on the rooftops. In view of public concerns, measurements of the RF/MW levels emitted by the base stations were carried out in this study. The values were compared with the exposure limits set by several organisations and countries. Measurements were performed at 200 sites around 47 mobile phone base stations. It was found that the RF/MW radiation from these base stations were well below the maximum exposure limits set by various agencies. (authors)

  5. Radiation emitting devices act

    International Nuclear Information System (INIS)

    1970-01-01

    This Act, entitled the Radiation Emitting Devices Act, is concerned with the sale and importation of radiation emitting devices. Laws relating to the sale, lease or import, labelling, advertising, packaging, safety standards and inspection of these devices are listed as well as penalties for any person who is convicted of breaking these laws

  6. Cosmic microwave background radiation

    International Nuclear Information System (INIS)

    Wilson, R.W.

    1979-01-01

    The 20-ft horn-reflector antenna at Bell Laboratories is discussed in detail with emphasis on the 7.35 cm radiometer. The circumstances leading to the detection of the cosmic microwave background radiation are explored

  7. Microwave discharge electrodeless lamps (MDEL). III. A novel tungsten-triggered MDEL device emitting VUV and UVC radiation for use in wastewater treatment.

    Science.gov (United States)

    Horikoshi, Satoshi; Miura, Takashi; Kajitani, Masatsugu; Serpone, Nick

    2008-03-01

    Exposure to low doses of the xenoestrogen bisphenol A (BPA) and to the hormonal 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide, an environmental endocrine disruptor, can have serious health consequences such as the induction of mammary gland ductal hyperplasias and carcinoma (LaChapelle et al., Reprod. Toxicol., 2007, 23, 20; Murray et al., Reprod. Toxicol., 2007, 23, 383). To the extent that these toxins are present in wastewaters (Donald et al., Sci. Total Environ. 1999, 231, 173; Brotons et al., Environ. Health Perspect. 1994, 103, 608; Olea et al., Environ. Health Perspect. 1996, 104, 298; Biles et al., J. Agric. Food Chem. 1997, 45, 3541; Markey et al., J. Steroid Biochem. Mol. Biol., 2003, 83, 235), we examined their oxidative destruction in aqueous media by a novel light source. A tungsten-triggered microwave discharge electrodeless lamp (W-MDEL) was fabricated for possible use in wastewater treatment using vacuum UV-transparent quartz in which a tungsten trigger, also embedded in quartz, was attached to the MDEL to aid in the self-ignition of the lamp on irradiation at low microwave power levels. The quantity of mercury gas in the W-MDEL was optimized by monitoring the continuous radiation and peak intensities of the emitted light in the vacuum UV (VUV) and UVC regions. The usefulness of the W-MDEL device was assessed through the degradation of 2,4-D and BPA in air-equilibrated aqueous media and in oxygen-saturated aqueous media. Enhanced degradation of these two xenoestrogenic toxins was achieved by increasing the number of W-MDEL devices while keeping constant the microwave radiation feeding each W-MDEL lamp. This novel lamp provides an additional light source in the photooxidation of environmental contaminants without the need for a metal-oxide photocatalyst. Under our conditions, process dynamics using the W-MDEL light source are greater than with the more conventional photochemical methods that employ low-pressure Hg arc electrode lamps in synthetic

  8. Tunable radiation emitting semiconductor device

    NARCIS (Netherlands)

    2009-01-01

    A tunable radiation emitting semiconductor device includes at least one elongated structure at least partially fabricated from one or more semiconductor materials exhibiting a bandgap characteristic including one or more energy transitions whose energies correspond to photon energies of light

  9. Non-Ionizing Radiation Used in Microwave Ovens

    Science.gov (United States)

    ... Non-Ionizing Radiation Used in Microwave Ovens Non-Ionizing Radiation Used in Microwave Ovens Explore the interactive, virtual ... can do Where to learn more About Non-Ionizing Radiation Used in Microwave Ovens Microwave Oven. Microwave ovens ...

  10. The cosmic microwave background radiation

    International Nuclear Information System (INIS)

    Wilson, R.W.

    1980-01-01

    The history is described of the discovery of microwave radiation of the cosmic background using the 20-foot horn antenna at the Bell Laboratories back in 1965. Ruby masers with travelling wave were used, featuring the lowest noise in the world. The measurement proceeded on 7 cm. In measuring microwave radiation from the regions outside the Milky Way continuous noise was discovered whose temperature exceeded the calculated contributions of the individual detection system elements by 3 K. A comparison with the theory showed that relict radiation from the Big Bang period was the source of the noise. The discovery was verified by measurements on the 20.1 cm wavelength and by other authors' measurements on 0.5 mm to 74 cm, and by optical measurements of the interstellar molecule spectrum. (Ha)

  11. Radiation Emitting Product Corrective Actions and Recalls

    Data.gov (United States)

    U.S. Department of Health & Human Services — This database provides descriptions of radiation-emitting products that have been recalled under an approved corrective action plan to remove defective and...

  12. Radiation-emitting Electronic Product Codes

    Data.gov (United States)

    U.S. Department of Health & Human Services — This database contains product names and associated information developed by the Center for all products, both medical and non-medical, which emit radiation. It...

  13. Biologic effects of electromagnetic radiation and microwave

    International Nuclear Information System (INIS)

    Deng Hua

    2002-01-01

    Electromagnetic radiation and microwave exist mankind's environment widely. People realize they disserve authors' health when authors make use of them. Electromagnetic radiation is one of the major physic factors which injure people's health. A review of the biologic mechanism about electromagnetic radiation and microwave, their harmful effects to human body, problems in authors' research and the prospect

  14. Measurement of microwave radiation from electron beam in the atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Ohta, I.S.; Akimune, H. [Faculty of Science and Engineering, Konan University, Kobe 658-8501 (Japan); Fukushima, M.; Ikeda, D. [Institute of Cosmic Ray Research, University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Inome, Y. [Faculty of Science and Engineering, Konan University, Kobe 658-8501 (Japan); Matthews, J.N. [University of Utah, Salt Lake City, UT 4112-0830 (United States); Ogio, S. [Graduate School of Science, Osaka City University, Osaka 558-8585 (Japan); Sagawa, H. [Institute of Cosmic Ray Research, University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Sako, T. [Solar-Terrestrial Environment Laboratory, Nagoya University, Nagoya 464-8601 (Japan); Shibata, T. [High Energy Accelerator Research Organization (KEK), Tsukuba 305-0801 (Japan); Yamamoto, T., E-mail: tokonatu@konan-u.ac.jp [Faculty of Science and Engineering, Konan University, Kobe 658-8501 (Japan)

    2016-02-21

    We report the use of an electron light source (ELS) located at the Telescope Array Observatory in Utah, USA, to measure the isotropic microwave radiation from air showers. To simulate extensive air showers, the ELS emits an electron beam into the atmosphere and a parabola antenna system for the satellite communication is used to measure the microwave radiation from the electron beam. Based on this measurement, an upper limit on the intensity of a 12.5 GHz microwave radiation at 0.5 m from a 10{sup 18} eV air shower was estimated to be 3.96×10{sup −16} W m{sup −2} Hz{sup −1} with a 95% confidence level.

  15. Early reionization by decaying particles and cosmic microwave background radiation

    International Nuclear Information System (INIS)

    Kasuya, S.; Kawasaki, M.

    2004-01-01

    We study the reionization scenario in which ionizing UV photons emitted from decaying particle, in addition to usual contributions from stars and quasars, ionize the universe. It is found that the scenario is consistent with both the first year data of the Wilkinson Microwave Anisotropy Probe and the fact that the universe is not fully ionized until z∼6 as observed by Sloan Digital Sky Survey. Likelihood analysis revealed that rather broad parameter space can be chosen. This scenario will be discriminated by future observations, especially by the EE polarization power spectrum of cosmic microwave background radiation

  16. Microwave radiation - Biological effects and exposure standards

    Energy Technology Data Exchange (ETDEWEB)

    Lindsay, I.R.

    1980-06-01

    The thermal and nonthermal effects of exposure to microwave radiation are discussed and current standards for microwave exposure are examined in light of the proposed use of microwave power transmission from solar power satellites. Effects considered include cataractogenesis at levels above 100 mW/sq cm, and possible reversible disturbances such as headaches, sleeplessness, irritability, fatigue, memory loss, cardiovascular changes and circadian rhythm disturbances at levels less than 10 mW/sq cm. It is pointed out that while the United States and western Europe have adopted exposure standards of 10 mW/sq cm, those adopted in other countries are up to three orders of magnitude more restrictive, as they are based on different principles applied in determining safe limits. Various aspects of the biological effects of microwave transmissions from space are considered in the areas of the protection of personnel working in the vicinity of the rectenna, interactions of the transmitted radiation with cardiac pacemakers, and effects on birds. It is concluded that thresholds for biological effects from short-term microwave radiation are well above the maximal power density of 1 mW/sq cm projected at or beyond the area of exclusion of a rectenna.

  17. Effects of Microwave Radiation on Oil Recovery

    Science.gov (United States)

    Esmaeili, Abdollah

    2011-12-01

    A variety of oil recovery methods have been developed and applied to mature and depleted reservoirs in order to improve the efficiency. Microwave radiation oil recovery method is a relatively new method and has been of great interest in the recent years. Crude oil is typically co-mingled with suspended solids and water. To increase oil recovery, it is necessary to remove these components. The separation of oil from water and solids using gravitational settling methods is typically incomplete. Oil-in-water and oil-water-solid emulsions can be demulsified and separated into their individual layers by microwave radiation. The data also show that microwave separation is faster than gravity separation and can be faster than conventional heating at many conditions. After separation of emulsion into water and oil layers, water can be discharged and oil is collected. High-frequency microwave recycling process can recover oil and gases from oil shale, residual oil, drill cuttings, tar sands oil, contaminated dredge/sediments, tires and plastics with significantly greater yields and lower costs than are available utilizing existing known technologies. This process is environmentally friendly, fuel-generating recycler to reduce waste, cut emissions, and save energy. This paper presents a critical review of Microwave radiation method for oil recovery.

  18. Microwave radiation mechanism in a pulse-laser-irradiated Cu foil target revisited

    International Nuclear Information System (INIS)

    Chen Ziyu; Li Jianfeng; Li Jun; Peng Qixian

    2011-01-01

    The microwave radiation mechanism in a Cu-based foil target irradiated by an intense laser pulse has been investigated. Microwave emission in the frequency range 0.5-4 GHz has been observed from a 200 ps laser pulse of intensity about 10 12 W cm -2 normally incident on the target surface. The total microwave power and energy emitted from the interaction were found to be about 0.4 W and 2 nJ, respectively, corresponding to an efficiency of coupling laser energy to microwave energy of 2x10 -8 . The result agrees well with quadrupole radiation calculated based on a circuit model of a laser plasma, which indicates that the radiative process can be explained by magnetic dipole or electric quadrupole radiation from the laser-produced symmetric poloidal current distribution at the plasma-target interface.

  19. Microwave radiation mechanism in a pulse-laser-irradiated Cu foil target revisited

    Energy Technology Data Exchange (ETDEWEB)

    Chen Ziyu; Li Jianfeng; Li Jun; Peng Qixian, E-mail: ziyuch@gmail.com [Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900 (China)

    2011-05-01

    The microwave radiation mechanism in a Cu-based foil target irradiated by an intense laser pulse has been investigated. Microwave emission in the frequency range 0.5-4 GHz has been observed from a 200 ps laser pulse of intensity about 10{sup 12} W cm{sup -2} normally incident on the target surface. The total microwave power and energy emitted from the interaction were found to be about 0.4 W and 2 nJ, respectively, corresponding to an efficiency of coupling laser energy to microwave energy of 2x10{sup -8}. The result agrees well with quadrupole radiation calculated based on a circuit model of a laser plasma, which indicates that the radiative process can be explained by magnetic dipole or electric quadrupole radiation from the laser-produced symmetric poloidal current distribution at the plasma-target interface.

  20. CASPER: Concordia Atmospheric SPectroscopy of Emitted Radiation

    Science.gov (United States)

    de Petris, M.; Catalano, A.; de Gregori, S.; Lamagna, L.; Lattanzi, V.; Luzzi, G.; Maoli, R.; Melchiorri, A.; Melchiorri, F.; Savini, G.; Vetrani, G. G.; Battistelli, E. S.; Valenziano, L.; Mandolesi, N.; Villa, F.; Cuttaia, F.; Ade, P. A. R.; Mauskopf, P.; Orlando, A.; Encrenaz, P.; Pardo, J. R.; Cernicharo, J.

    CASPER (Concordia Atmospheric SPectroscopy of Emitted Radiation) is a spectrometer proposed for installation at Dome C, devoted to measurements of atmospheric emission in the spectral region between 180 μm and 3 mm (3 55 cm-1). This instrument will be able to perform continuous spectral sampling at different altitudes at angular scales of 1°. From the recorded data it is possible to extract atmospheric transmittance within 1% in the whole wide operating band, together with water vapour content and O{2} and O{3} concentrations. CASPER will allow us to characterize the site for future FIR/mm telescopes. Atmospheric data recorded by CASPER will allow for correction of astrophysical and cosmological observations without the need for telescope-specific procedures and further loss of observation time with more precision in the observations themselves. Calibration of ground-based telescopes on known sky sources is strongly affected by atmospheric absorption. CASPER has this as its primary goal. The spectrometer is based on a Martin-Puplett interferometer. Two data sampling solutions will be performed: phase modulation & fast scan strategy. Sky radiation is collected towards the interferometer by an optical setup that allows the field of view, to explore the full 0° div 90° range of elevation angles. With a low spurious polarization instrument, monitoring of polarized atmospheric contribution will be possible.

  1. Applications of microwave radiation environmental remediation technologies

    International Nuclear Information System (INIS)

    Krause, T.R.; Helt, J.E.

    1993-01-01

    A growing number of environmental remediation technologies (e.g., drying, melting, or sintering) utilize microwave radiation as an integral part of the process. An increasing number of novel applications, such as sustaining low-temperature plasmas or enhancing chemical reactivity, are also being developed. An overview of such technologies being developed by the Department of Energy is presented. A specific example being developed at Argonne National Laboratory, microwave-induced plasma reactors for the destruction of volatile organic compounds, is discussed in more detail

  2. Cataracts induced by microwave and ionizing radiation

    International Nuclear Information System (INIS)

    Lipman, R.M.; Tripathi, B.J.; Tripathi, R.C.

    1988-01-01

    Microwaves most commonly cause anterior and/or posterior subcapsular lenticular opacities in experimental animals and, as shown in epidemiologic studies and case reports, in human subjects. The formation of cataracts seems to be related directly to the power of the microwave and the duration of exposure. The mechanism of cataractogenesis includes deformation of heat-labile enzymes, such as glutathione peroxide, that ordinarily protect lens cell proteins and membrane lipids from oxidative damage. Oxidation of protein sulfhydryl groups and the formation of high-molecular-weight aggregates cause local variations in the orderly structure of the lens cells. An alternative mechanism is thermoelastic expansion through which pressure waves in the aqueous humor cause direct physical damage to the lens cells. Cataracts induced by ionizing radiation (e.g., X-rays and gamma rays) usually are observed in the posterior region of the lens, often in the form of a posterior subcapsular cataract. Increasing the dose of ionizing radiation causes increasing opacification of the lens, which appears after a decreasing latency period. Like cataract formation by microwaves, cataractogenesis induced by ionizing radiation is associated with damage to the lens cell membrane. Another possible mechanism is damage to lens cell DNA, with decreases in the production of protective enzymes and in sulfur-sulfur bond formation, and with altered protein concentrations. Until further definitive conclusions about the mechanisms of microwaves and ionizing radiation induced cataracts are reached, and alternative protective measures are found, one can only recommend mechanical shielding from these radiations to minimize the possibility of development of radiation-induced cataracts. 74 references

  3. Risks of long-term effect of microwave radiation from mobile communication systems on human organism

    International Nuclear Information System (INIS)

    Chekhun, V.F.; Yakimenko, Yi.L.; Tsibulyin, O.S.; Sidorik, Je.P.; Chekhun, V.F.; Yakimenko, Yi.L.; Tsibulyin, O.S.; Sidorik, Je.P.

    2011-01-01

    It has been detected that commercial models of cell phones on the market of Ukraine sometimes emit microwaves in intensity by 1-2 orders of magnitude higher than the national safety limit for non-ionizing radiation. The survey of Ukrainian students has revealed an active usage of cell phones and a high percent of youth with the subjective feeling of physical discomfort and/or pain in head during cell phone talks. A significant time-dependent biological activity of the certain modes of low-intensity microwave radiation on the model of bird somitogenesis has been demonstrated.

  4. Can a tachyon emit light radiation in all directions

    Energy Technology Data Exchange (ETDEWEB)

    Ramanujam, G A [NGM Coll., Tamil Nadu (India). Dept. of Physics

    1976-03-01

    It is shown here that a critical analysis of the approaches employed by various authors to accommodate tachyons into special relativity leads one to the conclusion that a tachyon can emit light radiation only along its line of motion.

  5. SOR/72-43 Radiation Emitting Devices Regulations

    International Nuclear Information System (INIS)

    1972-01-01

    These Regulations of 10 February 1972, supplemented by SOR/77-895, lay down the classes of radiation emitting devices for the purposes of the Radiation Emitting Devices Act. They lay down their standards of design and construction and warning sign specifications and provide for the procedure to be followed by inspectors of such devices. The devices include inter alia extra-oral dental x-ray equipment, baggage inspection x-ray devices, laser scanners, television receivers. (NEA)

  6. Radiofrequency radiation leakage from microwave ovens

    International Nuclear Information System (INIS)

    Lahham, A.; Sharabati, A.

    2013-01-01

    This work presents data on the amount of radiation leakage from 117 microwave ovens in domestic and restaurant use in the West Bank, Palestine. The study of leakage is based on the measurements of radiation emissions from the oven in real-life conditions by using a frequency selective field strength measuring system. The power density from individual ovens was measured at a distance of 1 m and at the height of centre of door screen. The tested ovens were of different types, models with operating powers between 1000 and 1600 W and ages ranging from 1 month to >20 y, including 16 ovens with unknown ages. The amount of radiation leakage at a distance of 1 m was found to vary from 0.43 to 16.4 μW cm -1 with an average value equalling 3.64 μW cm -2 . Leakages from all tested microwave ovens except for seven ovens (∼6 % of the total) were below 10 μW cm -2 . The highest radiation leakage from any tested oven was ∼16.4 μW cm -2 , and found in two cases only. In no case did the leakage exceed the limit of 1 μWcm -1 recommended by the ICNIRP for 2.45-GHz radiofrequency. This study confirms a linear correlation between the amount of leakage and both oven age and operating power, with a stronger dependence of leakage on age. (authors)

  7. Interpretation of observed cosmic microwave background radiation

    International Nuclear Information System (INIS)

    Alfven, H.; Mendis, A.

    1977-01-01

    It is stated that the observed cosmic microwave background radiation, which closely fits a 2.7 K black body spectrum, is generally claimed to be the strongest piece of evidence in support of hot big bang cosmologies by its proponents. It is here stated that the observed radiation corresponds to the distribution of dust in galaxies or protogalaxies with a temperature approximately 110 K at the epoch corresponding to Z approximately 40, and not to a plasma of temperature > approximately 3000 K at an earlier epoch (Z > approximately 1000), as indicated by the canonical model of big bang cosmologies. The claim that the latter lends strong support to hot big bang cosmologies is stated to be without foundation. It is concluded that the microwave background radiation must be explained not in terms of a coupling between matter and radiation at the present epoch, but in terms of a coupling in a previous epoch within the framework of an evolutionary cosmology. (U.K.)

  8. BIOLOGICAL EFFECTS OF MICROWAVE RADIATION ON BRAIN TISSUE IN RATS

    Directory of Open Access Journals (Sweden)

    Boris Đinđić

    2003-04-01

    Full Text Available Exposure to microwave radiation induces multiple organ dysfunctions, especially in CNS.The aim of this work was investigation of biological effects of microwave radiation on rats' brain and determination of increased oxidative stress as a possible pathogenetic's mechanism.Wis tar rats 3 months old were divided in experimental (4 female and 4 male animal and control group (5 female and 4 male. This experimental group was constantly exposed to a magnetic field of 5 mG. We simulated using of mobile phones 30 min every day. The source of NIR emitted MF that was similar to mobile phones at 900 MHz. The rats were killed after 2 months. Biological effects were determined by observation of individual and collective behavior and body mass changes. Lipid per oxidation was determined by measuring quantity of malondialdehyde (MDA in brain homogenate.The animals in experimental group exposed to EMF showed les weight gain. The most important observations were changing of basic behavior models and expression of aggressive or panic behavior. The content of MDA in brain tissue is singificantly higher (1.42 times in rats exposed to electromagnetic fields (3,82±0.65 vs. control 2.69±0.42 nmol/mg proteins, p<0.01.Increased oxidative stress and lipid peroxidation after exposition in EM fields induced disorders of function and structure of brain.

  9. TRMM MICROWAVE IMAGER (TMI) WENTZ OCEAN PRODUCTS V3

    Data.gov (United States)

    National Aeronautics and Space Administration — The TRMM Microwave Imager (TMI) is a 5-channel, dual-polarized, passive microwave radiometer. Microwave radiation is emitted by the Earth's surface and by water...

  10. Cosmic thermalization and the microwave background radiation

    International Nuclear Information System (INIS)

    Rana, N.C.

    1981-01-01

    A different origin of the microwave background radiation (MBR) is suggested in view of some of the difficulties associated with the standard interpretation. Extensive stellar-type nucleosynthesis could provide radiation with the requisite energy density of the MBR and its spectral features are guaranteed by adequate thermalization of the above radiation by an ambient intergalactic dust medium. This thermalization must have occurred in quite recent epochs, say around epochs of redshift z = 7. The model emerges with consistent limits on the cosmic abundance of helium, the general luminosity evolution of the extragalactic objects, the baryonic matter density in the Universe (or, equivalently the deceleration parameter) and the degree of isotropy of MBR. The model makes definite predictions on issues like the properties of the intergalactic thermalizers, the degree of isotropy of MBR at submillimetre wavelengths and cluster emission in the far infrared. (author)

  11. Radiation-hardened microwave communications system

    International Nuclear Information System (INIS)

    Smith, S.F.; Crutcher, R.I.; Vandermolen, R.I.

    1990-01-01

    The consolidated fuel reprocessing program (CFRP) at the Oak Ridge National Laboratory (ORNL) has been developing signal transmission techniques and equipment to improve the efficiency of remote handling operations for nuclear applications. These efforts have been largely directed toward the goals of (a) remotely controlling bilateral force-reflecting servomanipulators for dexterous manipulation-based operations in remote maintenance tasks and (b) providing television viewing of the work site. In September 1987, developmental microwave transceiving hardware operating with dish antennas was demonstrated in the advanced integrated maintenance system (AIMS) facility at ORNL, successfully implementing both high-quality one-way television transmissions and simultaneous bidirectional digital control data transmissions with very low error rates. Initial test results based on digital transmission at a 1.0-Mbaud data rate indicated that the error rates of the microwave system were comparable to those of a hardwired system. During these test intervals, complex manipulator operations were performed, and the AIMS transporter was moved repeatedly without adverse effects on data integrity. Results of these tests have been factored into subsequent phases of the development program, with an ultimate goal of designing a fully radiation-hardened microwave signal transmission system for use in nuclear facilities

  12. An assessment of ultraviolet radiation components of light emitted ...

    African Journals Online (AJOL)

    An assessment of ultraviolet radiation components of light emitted from electric arc and their possible exposure risks. ... The study of Ultraviolet Radiation has of recent become interesting because of the health hazards it poses to human. Apart from its intensity reaching the earth from the sun, other man-made sources have ...

  13. Rapid and Decentralized Human Waste Treatment by Microwave Radiation.

    Science.gov (United States)

    Nguyen, Tu Anh; Babel, Sandhya; Boonyarattanakalin, Siwarutt; Koottatep, Thammarat

    2017-07-01

      This study evaluates the technical feasibility of using microwave radiation for the rapid treatment of human feces. Human feces of 1000 g were radiated with a commercially available household microwave oven (with rotation) at different exposure time lengths (30, 50, 60, 70, and 75 mins) and powers (600, 800, and 1000 W). Volume reduction over 90% occurred after 1000 W microwave radiation for 75 mins. Pathogen eradiation performances of six log units or more at a high range of microwave powers were achieved. Treatments with the same energy input of 1000 Wh, but at lower powers with prolonged exposure times, significantly enhanced moisture removal and volume reduction. Microwave radiation caused carbonization and resulted in a more stable end product. The energy content of the samples after microwave treatment at 1000 W and 75 mins is 3517 ± 8.85 calories/g of dried sample, and the product can also be used as compost.

  14. Biologic effects and health hazards of microwave radiation

    Energy Technology Data Exchange (ETDEWEB)

    Czerski, P; Ostrowski, K; Shore, M L; Silverman, C., Suess, M.J.; Waldeskog, B

    1974-01-01

    Proceedings of an international symposium held in Warsaw, 15--18 Oct. 1973, sponsored by the World Health Organization, the U.S. Department of Health, Education and Welfare, and the Polish Scientific Council to the Minister of Health and Social Welfare are presented. It covered numerous aspects of exposure to microwave radiation. The papers more specifically relating to occupational exposure to microwaves deal with: measurement of microwave radiations, clinical manifestations, neurological findings, health status of microwave workers, blood protein disorders, effects of electromagnetic fields in densely populated areas, microwave cataract and concomitant pathology, retinal changes, assessment of lens translucency in microwave workers. A list of participants at the symposium and an author and subject index are appended.

  15. Influence of 2. 45 GHz microwave radiation on enzyme activity

    Energy Technology Data Exchange (ETDEWEB)

    Galvin, M J; Parks, D L; McRee, D I

    1981-05-01

    The in vitro activity of acetylcholinesterase and creatine phosphokinase was determined during in vitro exposure to 2.45 GHz microwave radiation. The enzyme activities were examined during exposure to microwave radiation at specific absorption rates (SAR) of 1, 10, 50, and 100 mW/g. These specific absorption rates had no effect on the activity of either enzyme when the temperature of the control and exposed samples were similar. These data demonstrate that the activity of these two enzymes is not affected by microwave radiation at the SARs and frequency employed in this study.

  16. Environmental levels of microwave radiation around a satellite earth station

    International Nuclear Information System (INIS)

    Joyner, K.H.; Bangay, M.J.

    1986-01-01

    This paper discusses the background to claims of possible adverse health effects arising from exposure to environmental levels of microwave radiation around satellite earth stations. Results of a recent survey of the environmental levels of microwave radiation around two 32 metre diameter satellite communications antennas owned and operated by the Overseas Telecommunications Commission (OTC) of Australia are presented. From the measurements obtained in this survey it can be concluded that the environmental levels of microwave radiation around the OTC and similar satellite facilities do not pose a health risk to persons in the vicinity

  17. Noncommutative black-body radiation: Implications on cosmic microwave background

    International Nuclear Information System (INIS)

    Fatollahi, A.H.; Hajirahimi, M.

    2006-01-01

    Including loop corrections, black-body radiation in noncommutative space is anisotropic. A direct implication of possible space non-commutativity on the cosmic microwave background map is argued. (authors)

  18. Removal of Pseudomonas aeruginosa in hospital air using microwave radiation

    Directory of Open Access Journals (Sweden)

    firouz valipour

    2013-09-01

    Conclusion: Microwave radiation with high functionality can be used to remove bacterial air pollutions. They can help to control biological agents in hospitals and medical centers with good efficiency.

  19. Toxicologic study of electromagnetic radiation emitted by television and video display screens and cellular telephones on chickens and mice

    International Nuclear Information System (INIS)

    Bastide, M.; Youbicier-Simo, B.J.; Lebecq, J.C.; Giaimis, J.; Youbicier-Simo, B.J.

    2001-01-01

    The effects of continuous exposure of chick embryos and young chickens to the electromagnetic fields (EMFs) emitted by video display units (VDUs) and GSM cell phone radiation, either the whole spectrum emitted or attenuated by a copper gauze, were investigated. Permanent exposure to the EMFs radiated by a VDU was associated with significantly increased fetal loss (47-68%) and markedly depressed levels of circulating specific antibodies (lgG), corticosterone and melatonin. We have also shown that under chronic exposure conditions, GSM cell phone radiation was harmful to chick embryos, stressful for healthy mice and, in this species, synergistic with cancer insofar as it depleted stress hormones. The same pathological results were observed after substantial reduction of the microwaves radiated from the cell phone by attenuating them with a copper gauze. (author)

  20. Observation of microwave radiation using low-cost detectors at the ANKA storage ring*

    CERN Document Server

    Judin, V; Hofmann, A; Huttel, E; Kehrer, B; Klein, M; Marsching, S; Müller, A S; Nasse, M; Smale, N; Caspers, F; Peier, P

    2011-01-01

    Synchrotron light sources emit Coherent Synchrotron Radiation (CSR) for wavelengths longer than or equal to the bunch length. At most storage rings CSR cannot be observed, because the vacuum chamber cuts off radiation with long wavelengths. There are different approaches for shifting the CSR to shorter wavelengths that can propagate through the beam pipe, e.g.: the accelerator optics can be optimized for a low momentum compaction factor, thus reducing the bunch length. Alternatively, laser slicing can modulate substructures on long bunches [1]. Both techniques extend the CSR spectrum to shorter wavelengths, so that CSR is emitted at wavelengths below the waveguide shielding cut off. Usually fast detectors, like superconducting bolometer detector systems or Schottky barrier diodes, are used for observation of dynamic processes in accelerator physics. In this paper, we present observations of microwave radiation at ANKA using an alternative detector, a LNB (Low Noise Block) system. These devices are usually use...

  1. Microwave-assisted one-step synthesis of white light-emitting carbon dot suspensions

    Science.gov (United States)

    Vanessa, Hinterberger; Wenshuo, Wang; Cornelia, Damm; Simon, Wawra; Martin, Thoma; Wolfgang, Peukert

    2018-06-01

    In this contribution, we demonstrate that an aqueous solution with adjustable fluorescent color, including white light emission, can be achieved by a rapid one-step microwave synthesis method resulting in a mixture of blue-emitting carbon dots (CDs) and the yellow-emitting 2,3-diaminophenazine (DAP). Aqueous mixtures of o-phenylene-diamine (oPD) and citric acid (CA) are used as precursors. The resulting product structures are analyzed by FT-IR and NMR spectroscopy and the size of the resulting CDs is determined by atomic force microscopy to be 1.1 ± 0.3 nm. The synthesized solution exhibits two fluorescence emission peaks at 430 and 560 nm, which were found to originate from the CDs and DAP, respectively. The intensity ratio of both fluorescence peaks depends on pH, which is driven by the protonation state of DAP. In consequence, the fluorescence emission color of the CD solution can be tuned precisely and reproducibly from blue to white to yellow by careful control of the pH. Finally, at a pH level of 5.4, at which there is equal blue and yellow emission intensity, a white light emitting solution can be successfully produced in a very fast and simple synthesis procedure.

  2. Electromagnetic Radiofrequency Radiation Emitted from GSM Mobile Phones Decreases the Accuracy of Home Blood Glucose Monitors

    Science.gov (United States)

    Mortazavi, SMJ; Gholampour, M; Haghani, M; Mortazavi, G; Mortazavi, AR

    2014-01-01

    Mobile phones are two-way radios that emit electromagnetic radiation in microwave range. As the number of mobile phone users has reached 6 billion, the bioeffects of exposure to mobile phone radiation and mobile phone electromagnetic interference with electronic equipment have received more attention, globally. As self-monitoring of blood glucose can be a beneficial part of diabetes control, home blood glucose testing kits are very popular. The main goal of this study was to investigate if radiofrequency radiation emitted from a common GSM mobile phone can alter the accuracy of home blood glucose monitors. Forty five female nondiabetic students aged 17-20 years old participated in this study. For Control-EMF group (30 students), blood glucose concentration for each individual was measured in presence and absence of radiofrequency radiation emitted by a common GSM mobile phone (HTC touch, Diamond 2) while the phone was ringing. For Control- Repeat group (15 students), two repeated measurements were performed for each participant in the absence of electromagnetic fields. The magnitude of the changes between glucose levels in two repeated measurements (|ΔC|) in Control-Repeat group was 1.07 ± 0.88 mg/dl while this magnitude for Control-EMF group was 7.53 ± 4.76 mg/dl (P electromagnetic interference in home blood glucose monitors. It can be concluded that electromagnetic interference from mobile phones has an adverse effect on the accuracy of home blood glucose monitors. We suggest that mobile phones should be used at least 50 cm away from home blood glucose monitors. PMID:25505778

  3. Electromagnetic Radiofrequency Radiation Emitted from GSM Mobile Phones Decreases the Accuracy of Home Blood Glucose Monitors

    Directory of Open Access Journals (Sweden)

    SMJ Mortazavi

    2014-09-01

    Full Text Available Mobile phones are two-way radios that emit electromagnetic radiation in microwave range. As the number of mobile phone users has reached 6 billion, the bioeffects of exposure to mobile phone radiation and mobile phone electromagnetic interference with electronic equipment have received more attention, globally. As self-monitoring of blood glucose can be a beneficial part of diabetes control, home blood glucose testing kits are very popular. The main goal of this study was to investigate if radiofrequency radiation emitted from a common GSM mobile phone can alter the accuracy of home blood glucose monitors. Forty five female nondiabetic students aged 17-20 years old participated in this study. For Control-EMF group (30 students, blood glucose concentration for each individual was measured in presence and absence of radiofrequency radiation emitted by a common GSM mobile phone (HTC touch, Diamond 2 while the phone was ringing. For Control- Repeat group (15 students, two repeated measurements were performed for each participant in the absence of electromagnetic fields. The magnitude of the changes between glucose levels in two repeated measurements (ΔC in Control-Repeat group was 1.07 ± 0.88 mg/dl while this magnitude for Control-EMF group was 7.53 ± 4.76 mg/dl (P < 0.001, two-tailed test. To the best of our knowledge, this is the first study to assess the electromagnetic interference in home blood glucose monitors. It can be concluded that electromagnetic interference from mobile phones has an adverse effect on the accuracy of home blood glucose monitors. We suggest that mobile phones should be used at least 50 cm away from home blood glucose monitors.

  4. Microwave synthesis of homogeneous and highly luminescent BCNO nanoparticles for the light emitting polymer materials

    Energy Technology Data Exchange (ETDEWEB)

    Iwasaki, Hideharu [Battery Materials Laboratory, Kurashiki Research Center, Kuraray Co., Ltd., 2045-1, Sakazu, Kurashiki, Okayama 710-0801 (Japan); Department of Chemical Engineering, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi Hiroshima 739 8527 (Japan); Ogi, Takashi, E-mail: ogit@hiroshima-u.ac.jp [Department of Chemical Engineering, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi Hiroshima 739 8527 (Japan); Iskandar, Ferry [Department of Physics, Institute of Technology Bandung, Ganesha 10, Bandung 40132, West Java (Indonesia); Aishima, Kana; Okuyama, Kikuo [Department of Chemical Engineering, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi Hiroshima 739 8527 (Japan)

    2015-10-15

    Nano-sized boron carbon oxynitride (BCNO) phosphors around 50 nm containing no rare earth metal and free from color heterogeneity were synthesized from mixtures of boric acid, urea, and citric acid by microwave heating with substantially shorter reaction times and lower temperatures than in the conventional BCNO preparation method such as electric-furnace heating. The emission wavelength of the phosphors varied with the mixing ratio of raw materials and it was found that lowering the proportion of urea to boric acid or citric acid tended to increase the internal quantum yield and shorten the emission wavelength under excitation at 365 nm. It was also found for the first time that a light-emitting polymer could be synthesized from a mixture of the prepared BCNO nanoparticles and a polyvinyl alcohol. This polymer composite exhibited uniform dispersion and stabilization of the luminescence and had a high internal quantum yield of 54%, which was higher than that of the phosphor alone. - Highlights: • Nano-sized BCNO phosphor was synthesized via microwave heating. • BCNO nanophosphor has homogeneous and high luminescence. • Emission wavelength was tunable by changing the ratio of precursor components. • BCNO nanophosphor can be easily dispersed in a polyvinyl alcohol. • BCNO–polymer composite exhibited uniform high internal quantum yield.

  5. The influence of microwave radiation on the failure of rocks

    Directory of Open Access Journals (Sweden)

    Lovás Michal

    2000-09-01

    Full Text Available The heating and processing of materials using microwaves becomes increasingly popular for industrial applications. Compared to conventional heating, microwave processing can provide a rapid, the production of materials with unique properties, and reductions in manufacturing costs and processing times.The positive influence of the microwave radiation on the faulting of the individual rocks is described. At the heating of the heterogeneous ores, the microwaves have an selective effect for individual mineral components. Owing to the different degree of to heating and thermal dilatation the stress and destructive attendants arise, which increase the faulting of rocks. The rate of the faulting has been investigated on the basis of measurement of the elastic waves motion velocity by the impulse-dynamic method.On the basis of the measured values of elastic wave motion in the observed rocks before and after their microwave heating the coefficient of faulting was computed according to the relation (1. Subsequently, from these coefficients the rate of faulting was determined for individual rocks according to Jaeger (Table 1.Various rate of rocks faulting caused by the radiation depend on their ability to absorb microwave power. High rate of faulting was observed in rocks with strong absorption of microwave power unlike from substances which weakly absorb the radiation. Particularly, a high rate of faulting after microwave heating was observed at samples of limestone (Rožòava-Jovice and magnesite (Haèava. Low rate of faulting was obtained in the case of granodiorite (Podhradová, granite (Hnilec, sandstone (Horelica, marble (Koelga and andesite (Hubošovce.The influence of microwave energy on the rate of rocks faulting was confirmed. The new knowledge can be applied for the intensification of the rock disintegration processes.

  6. Plasma acceleration by means of microwave radiation pressure

    International Nuclear Information System (INIS)

    Fukumura, Takashi; Takamoto, Teruo

    1977-01-01

    In the electric discharge of gas with microwaves, intense reflection waves occur simultaneously with the discharge, so the plasma ionized and formed by the microwaves is accelerated due to large radiation pressure. The basic experiment made, aiming at plasma gun, is described. In the gas electric discharge, the plasma flow velocity proportional to the reflected power is obtained. For 550 W microwave input power, the plasma velocity of 1 x 10 4 m/s was obtained. The accelerated plasma is bunched; its front as mass travels, recombines and disappears. (Mori, K.)

  7. Radiative flux emitted by a burning PMMA slab

    International Nuclear Information System (INIS)

    Parent, G; Acem, Z; Collin, A; Berfroi, R; Boulet, P; Pizzo, Y; Mindykowski, P; Kaiss, A; Porterie, B

    2012-01-01

    The degradation of a PMMA sample has been studied based on experimental results obtained for the radiation emission by a burning slab. Observations of the infrared emission perpendicular to the plate, in the range where the optically thin flame is weakly emitting, indicate a plate temperature close to 680 K which is an indication on the surface temperature during the degradation process. Observations from the side allow a flame characterization without the plate emission superimposition. This is a promising way for evaluating data regarding the flame characteristics: temperature, gaz concentration and soot volumetric fraction.

  8. Effect of microwave radiation on coal flotation

    Energy Technology Data Exchange (ETDEWEB)

    Ozbayoglu, G.; Depci, T.; Ataman, N. [Middle East Technical University, Ankara (Turkey). Mining Engineering Department

    2009-07-01

    Most low-rank coals are high in moisture and acid functional groups, therefore showing poor floatability. Drying, which removes the water molecules trapped in the pores and adsorbed at the surface of coal, decreases the hydrophilic character and improves the floatability. Microwave heating, whose simplest application is drying, was applied at 0.9 kW power level for 60 sec exposure time in the experiments to decrease the moisture content of coal in order to enhance the hydrophobicity. The flotation tests of microwave-treated coal by using heptanol and octanol lead to a higher flotation yield and ash removal than original coal.

  9. Long-range correlation in cosmic microwave background radiation.

    Science.gov (United States)

    Movahed, M Sadegh; Ghasemi, F; Rahvar, Sohrab; Tabar, M Reza Rahimi

    2011-08-01

    We investigate the statistical anisotropy and gaussianity of temperature fluctuations of Cosmic Microwave Background (CMB) radiation data from the Wilkinson Microwave Anisotropy Probe survey, using the Multifractal Detrended Fluctuation Analysis, Rescaled Range, and Scaled Windowed Variance methods. Multifractal Detrended Fluctuation Analysis shows that CMB fluctuations has a long-range correlation function with a multifractal behavior. By comparing the shuffled and surrogate series of CMB data, we conclude that the multifractality nature of the temperature fluctuation of CMB radiation is mainly due to the long-range correlations, and the map is consistent with a gaussian distribution.

  10. Experimental facility for explosive energy conversion into coherent microwave radiation

    International Nuclear Information System (INIS)

    Vdovin, V.A.; Korzhenevskij, A.V.; Cherepenin, V.A.

    2003-01-01

    The explosive energy conversion into the microwave radiation energy is considered with application of the explosion magnetic generator, heavy-current electron accelerator and Cherenkov microwave range generator. The electron accelerator formed the beam of 33 cm in diameter and current of ∼ 25 kA. The electrodynamic system of the SHF-generator has the diameter of ∼ 35 cm and it is accomplished in the form of the periodical nonuniform dielectric. The proposed explosive energy conversion scheme makes it possible to obtain the radiation capacity of approximately 100 MW in the 3-cm wave range by the pulse duration of ∼ 800 ns [ru

  11. Null bactericidal effect of ultraviolet radiation emitted by LEDs.

    Directory of Open Access Journals (Sweden)

    Francisco Alcántara Muñoz

    2016-11-01

    Full Text Available This research has aimed to assess the bactericidal effect of ultraviolet light emitted by LEDS on the growth on Petri dishes of microorganisms whose legal limits in foods have been established. An electrically fed apparatus has been designed with precise timing and a camera to prevent light spillage, in which two ultraviolet radiation emission devices were connected by LED technology at different wavelengths: through an array of LEDS emitting at around 350nm, and a single specific emission LED at 280nm. 1000 cfu of E. Coli and S. aureus sown on PCA were used as prototypes of gram negative and positive bacteria, respectively, onto which ultraviolet light was radiated at different time intervals, by means of both devices, with the whole experiment being carried out in triplicate . In none of the three series of treatments at the two wavelengths were reductions in microbial growth observed. The series of sowings on PCA were done on unseeded plates in order to be able to discard the likelihood of subsequent recontamination.

  12. Microwave assisted transformation of N,N-diphenylamine as precursors of organic light emitting diodes (OLED)

    Energy Technology Data Exchange (ETDEWEB)

    Jefri,; Wahyuningrum, Deana, E-mail: deana@chem.itb.ac.id [Organic Chemistry Research Division, Department of Chemistry, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jalan Ganesha 10, Bandung 40132 (Indonesia)

    2015-09-30

    In this research, study on the transformation of N,N-diphenylamine (DPA) using iodine (I2) utilizing solid state Microwave Assisted Organic Synthesis (MAOS) method has been carried out. The reaction was performed by variations of three parameters namely the mole of reagents, the amount and type of solid support (alumina/Al2O3), and the reaction conditions. Experimental results showed that neutral-alumina was a better solid support than basic-alumina. The optimum temperature for the reaction was approximately at 125-133 °C with reaction time of 15 minutes and microwave reactor power at 500-600 W. The separation of the yellowish green product solution with preparative Thin Layer Chromatography (TLC) method using n-hexane:ethyl acetate = 4:1 (v/v) as eluent yielded two fractions (I and II) and both fractions can undergo fluorescence under 365 nm UV light. Based on the LC chromatogram with methanol:water = 95:5 (v/v) as eluent and its corresponding mass spectra (ESI+), fraction I contained three compounds, which were tetracarbazole A, triphenylamine, and impurities in the form of plasticizer such as bis(2-ethylhexyl) phthalate. Fraction II also contained three compounds, which were tetracarbazole C, tetraphenylhydrazine, and plasticizer such as bis(2-ethylhexyl) phthalate. Both FT-IR (KBr disks) and NMR (500 MHz, CDCl{sub 3}) spectra of fraction I and II confirmed the aromatic amine groups in those compounds. The observed fluorescence colors of fraction I and II were violet and violet-blue, respectively. Based on their structures and fluorescence characters, the compounds in fraction I and II have the potential to be used as Organic Light Emitting Diode (OLED) compound precursors.

  13. Hopping Conductivity Enhanced by Microwave Radiation

    International Nuclear Information System (INIS)

    Ovadyahu, Z

    2012-01-01

    Hopping conductivity is enhanced when exposed to microwave (MW) fields. Data taken on several Anderson-localized systems and granular-aluminium are presented to illustrate the generality of the phenomenon. It is suggested that the effect is due to a field-enhanced hopping, which is the ac version of a non-ohmic effect familiar from studies in the dc transport regime.

  14. Short-duration exposure to 2.45 GHz microwave radiation induces ...

    African Journals Online (AJOL)

    OBEMBE

    The genotoxic effects of 2.45 GHz microwave (MW) radiation on the testis and ovary of Sprague Dawley rats was ... Microwave (MW) radiation is a non-ionizing electromagnetic radiation ..... microwave field and not in any way related to indirect.

  15. Autonomous low-noise system for broadband measurements of the cosmic microwave background radiation

    Science.gov (United States)

    Dekoulis, George

    2009-05-01

    This paper describes the digital side implementation of a new suborbital experiment for the measurement of broadband radiation emissions of the Cosmic Microwave Background (CMB) anisotropy. The system has been used in campaign mode for initial mapping of the galactic radiation power received at a single frequency. The recorded galactic sky map images are subsequently being used to forecast the emitted radiation at neighboring frequencies. A planned second campaign will verify the prediction algorithms efficiency in an autonomous manner. The system has reached an advanced stage in terms of hardware and software combined operation and intelligence, where other Space Physics measurements are performed autonomously depending on the burst event under investigation. The system has been built in a modular manner to expedite hardware and software upgrades. Such an upgrade has recently occurred mainly to expand the frequency range of space observations.

  16. Radiation-hardened microwave communications system

    Science.gov (United States)

    Smith, S. F.; Bible, D. W.; Crutcher, R. I.; Hannah, J. H.; Moore, J. A.; Nowlin, C. H.; Vandermolen, R. I.; Chagnot, D.; Leroy, A.

    1993-03-01

    To develop a wireless communication system to meet the stringent requirements for a nuclear hot cell and similar environments, including control of advanced servomanipulators, a microwave signal transmission system development program was established to produce a demonstration prototype for the Consolidated Fuel Reprocessing Program at Oak Ridge National Laboratory (ORNL). Proof-of-principle tests in a partially metal lined enclosure at ORNL successfully demonstrated the feasibility of directed microwave signal transmission techniques for remote systems applications. The potential for much more severe radio-frequency (RF) multipath propagation conditions in fully metal lined cells led to a programmatic decision to conduct additional testing in more typical hot-cell environments at other sites. Again, the test results were excellent. Based on the designs of the earlier systems, an advanced microwave signal transmission system configuration was subsequently developed that, in highly reflective environments, will support both high-performance video channels and high baud-rate digital data links at total gamma dose tolerance levels exceeding 10(exp 7) rads and at elevated ambient temperatures.

  17. Radiation-hardened microwave communications system

    International Nuclear Information System (INIS)

    Smith, S.F.; Bible, D.W.; Crutcher, R.I.; Hannah, J.H.; Moore, J.A.; Nowlin, C.H.; Vandermolen, R.I.; Chagnot, D.; LeRoy, A.

    1993-01-01

    To develop a wireless communication system to meet the stringent requirements for a nuclear hot cell and similar environments, including control of advanced servomanipulators, a microwave signal transmission system development program was established to produce a demonstration prototype for the Consolidated Fuel Reprocessing Program at Oak Ridge National Laboratory (ORNL). Proof-of-principle tests in a partially metal lined enclosure at ORNL successfully demonstrated the feasibility of directed microwave signal transmission techniques for remote systems applications. The potential for much more severe radio-frequency (RF) multipath propagation conditions in fully metal lined cells led to a programmatic decision to conduct additional testing in more typical hot-cell environments at other sites. Again, the test results were excellent. Based on the designs of the earlier systems, an advanced microwave signal transmission system configuration was subsequently developed that, in highly reflective environments, will support both high-performance video channels and high baud-rate digital data links at total gamma dose tolerance levels exceeding 10 7 rads and at elevated ambient temperatures

  18. Angular anisotropy of the cosmic microwave background radiation

    International Nuclear Information System (INIS)

    Silk, J.

    1982-01-01

    The theory of fluctuations in the cosmic microwave background radiation is reviewed. Anisotropy on large-scale (dipole and quadrupole) and on small scales is discussed. The smoothing effects of secondary ionization (fractional ionization x) are found to be unimportant over an angular scale greater than approx.= 5(OMEGAx)sup(1/3) degrees. (author)

  19. Evaluation of stray radiofrequency radiation emitted by electrosurgical devices

    International Nuclear Information System (INIS)

    De Marco, M; Maggi, S

    2006-01-01

    Electrosurgery refers to the passage of a high-frequency, high-voltage electrical current through the body to achieve the desired surgical effects. At the same time, these procedures are accompanied by a general increase of the electromagnetic field in an operating room that may expose both patients and personnel to relatively high levels of radiofrequency radiation. In the first part of this study, we have taken into account the radiation emitted by different monopolar electrosurgical devices, evaluating the electromagnetic field strength delivered by an electrosurgical handle and straying from units and other electrosurgical accessories. As a summary, in the worst case a surgeon's hands are exposed to a continuous and pulsed RF wave whose magnetic field strength is 0.75 A m -1 (E-field 400 V m -1 ). Occasionally stray radiation may exceed ICNIRP's occupational exposure guidelines, especially close to the patient return plate. In the second part of this paper, we have analysed areas of particular concern to prevent electromagnetic interference with some life-support devices (ventilators and electrocardiographic devices), which have failed to operate correctly. Most clinically relevant interference occurred when an electrosurgery device was used within 0.3 m of medical equipment. In the appendix, we suggest some practical recommendations intended to minimize the potential for electromagnetic hazards due to therapeutic application of RF energy

  20. Quantum dot superluminescent light emitting diodes: Ideal blackbody radiators?

    Energy Technology Data Exchange (ETDEWEB)

    Blazek, Martin; Elsaesser, Wolfgang [Institute of Applied Physics, Darmstadt University of Technology (Germany); Hopkinson, Mark [Dept. E and E.E, University of Sheffield (United Kingdom); Krakowski, Michel [Alcatel Thales, III-V Lab. (France)

    2008-07-01

    Quantum dot (QD) superluminescent light emitting diodes (SLEDs) provide large optical bandwidths at desired wavelengths and are therefore promising devices for incoherent light application. The intensity noise behavior of QD SLEDs is of fundamental physical interest as it provides insight into the photon emission process. We performed high precision intensity noise measurements over several decades of optical output power. For low driving currents spontaneous emission leads to Shot Noise. For high currents we find excess noise behavior with Amplified Spontaneous Emission acting as the dominant source of noise. The QD SLEDs' noise can be described as blackbody radiation noise with a limited number of optical modes. It is therefore possible to identify the SLEDs' relevant intensity noise parameters.

  1. Topological magnetoelectric effects in microwave far-field radiation

    Energy Technology Data Exchange (ETDEWEB)

    Berezin, M.; Kamenetskii, E. O.; Shavit, R. [Microwave Magnetic Laboratory, Department of Electrical and Computer Engineering, Ben Gurion University of the Negev, Beer Sheva (Israel)

    2016-07-21

    Similar to electromagnetism, described by the Maxwell equations, the physics of magnetoelectric (ME) phenomena deals with the fundamental problem of the relationship between electric and magnetic fields. Despite a formal resemblance between the two notions, they concern effects of different natures. In general, ME-coupling effects manifest in numerous macroscopic phenomena in solids with space and time symmetry breakings. Recently, it was shown that the near fields in the proximity of a small ferrite particle with magnetic-dipolar-mode (MDM) oscillations have the space and time symmetry breakings and the topological properties of these fields are different from the topological properties of the free-space electromagnetic fields. Such MDM-originated fields—called magnetoelectric (ME) fields—carry both spin and orbital angular momenta. They are characterized by power-flow vortices and non-zero helicity. In this paper, we report on observation of the topological ME effects in far-field microwave radiation based on a small microwave antenna with a MDM ferrite resonator. We show that the microwave far-field radiation can be manifested with a torsion structure where an angle between the electric and magnetic field vectors varies. We discuss the question on observation of the regions of localized ME energy in far-field microwave radiation.

  2. Radiation protection in occupational exposure to microwave electrotherapy units

    International Nuclear Information System (INIS)

    Guardia, V.; Ferrer, S.; Alonso, O.; Almonacid, M.

    2012-01-01

    During the last years, electromagnetic emitters are more and more commonly used for therapeutic treatments in electrotherapy centers. This extended use has caused worries workers, who believe that microwave radiation radiation might have effects similar to those induced by radioactivity, even if the only effects recognised by international regulatory bodies concerning microwave exposure of humans are those of thermal origin. The present study aims to answer the existing concerns about electromagnetic exposure in electrotherapy facilities. After monitoring environmental values in an electrotherapy facility, we conclude that actions must be undertaken in order to reduce the exposure levels, as proposed by the current European guidelines, which should become legally binding for all EU state members within the current year. With the purpose of reducing potential risks of occupational overexposure, we are developing innovative fabrics for microwave shielding. These new materials are able to attenuate 85% of the microwave radiation. As these are light materials, they can be used in all kind of facilities, as wall covers, movable screens or even as personal protection, like lab clothes or gloves. (Author) 6 refs.

  3. Microwave radiative transfer intercomparison study for 3-D dichroic media

    International Nuclear Information System (INIS)

    Battaglia, A.; Davis, C.P.; Emde, C.; Simmer, C.

    2007-01-01

    Three different numerical methods capable of solving the radiative transfer of microwave radiation within 3-D dichroic media are compared. A case study, represented by an intense rain shaft populated by perfectly oriented oblate raindrops, is analysed in detail, including a discussion of the behaviour of all four Stokes components. Results demonstrate an acceptable agreement between all Monte Carlo methods. The method based on a discrete ordinates scheme agrees only qualitatively with the Monte Carlo outputs. Because of its lower computational cost the backward Monte Carlo technique based on importance sampling represents the most efficient way to face passive microwave radiative transfer problems related to optically thick 3-D structured clouds including non-spherical preferentially oriented hydrometeors

  4. A unique combination of infrared and microwave radiation accelerates wound healing.

    Science.gov (United States)

    Schramm, J Mark; Warner, Dave; Hardesty, Robert A; Oberg, Kerby C

    2003-01-01

    Light or electromagnetic radiation has been reported to enhance wound healing. The use of selected spectra, including infrared and microwave, has been described; however, no studies to date have examined the potential benefit of combining these spectra. In this study, a device that emits electromagnetic radiation across both the infrared and microwave ranges was used. To test the effects of this unique electromagnetic radiation spectrum on wound healing, two clinically relevant wound-healing models (i.e., tensile strength of simple incisions and survival of McFarlane flaps) were selected. After the creation of a simple full-thickness incision (n = 35 rats) or a caudally based McFarlane flap (n = 33 rats), animals were randomly assigned to one of three treatment groups: untreated control, infrared, or combined electromagnetic radiation. Treatment was administered for 30 minutes, twice daily for 18 days in animals with simple incisions, and 15 days in animals with McFarlane flaps. The wound area or flap was harvested and analyzed, blinded to the treatment regimens. A p value of less than 0.05 obtained by analysis of variance was considered to be statistically significant. Animals receiving combined electromagnetic radiation demonstrated increased tensile strength (2.62 N/mm2) compared with animals receiving infrared radiation (2.36 N/mm2) or untreated controls (1.73 N/mm2, p radiation had increased flap survival (78.0 percent) compared with animals receiving infrared radiation (69.7 percent) and untreated controls (63.1 percent, p radiation provided a distinct advantage in wound healing that might augment current treatment regimens.

  5. The Exposure Duration and Distance Effects of Microwave Radiation from Wireless Routers on Sperm Parameters of Wistar Rats

    Directory of Open Access Journals (Sweden)

    S Safari

    2015-12-01

    Full Text Available Background & aim: As a communication technology, Wi-Fi allows electronic devices such as laptops to exchange data or connect to a network resource such as the Internet via a wireless network access point  using 2.4 GHz microwave radiation. However, with the exponential development of wireless communication technology, the public concern regarding the safety of this technology has increased rapidly. The main goal of this study was to assess the bio effects of duration of exposure of an animal model to 2.4 GHz microwave radiation emitted from a common Wi-Fi router on sperm quality. Method: In the present experimental study, 84 male Wistar rats were used. The mice were randomly divided based on the duration of exposure to microwave radiation and distance to the modem into seven groups of 12. Group II rats were exposed to 2.4 GHz microwave radiation for 2 hours per day in term of 7 days at a distance of 30 cm from the router. The rats in this group were allowed to live for 53 days then sacrificed and semen samples analyzed. Rats in all the groups except group II, were sacrificed 30 min to 1 hr.After exposure. To analyze the results, The Mann-Whitney and Kruskal-Wallis tests were used. Result: The average sperm with normal morphology, testes weight and number of spermatogonial cells after exposure to microwave radiation decreased. With increasing exposure time and reduce the distance to the modem, testis weight and the number of spermatogonia cells significantly reduced. Conclusion: Beams of microwave radiation from Wi-Fi modems leads to sperm morphological changes and weight loss of testicular spermatogonia. With increasing exposure time and reduce the distance to the modem, testis weight and the number of spermatogonia cells significantly reduced.

  6. Continuum radiation emitted from transition metals under ion bombardment

    International Nuclear Information System (INIS)

    El Boujlaidi, A.; Kaddouri, A.; Ait El Fqih, M.; Hammoum, K.; Aouchiche, H.

    2012-01-01

    Optical emission of transition metals has been studied during 5 keV Kr + ions bombardment within and without oxygen atmosphere in the colliding chamber. The observed spectra consist of a series of discrete lines superimposed on a broad continuum. Generally, the emission intensity was influenced by the presence of oxygen giving rise to transient effects as well as to an increase in the line intensity. The behaviours of spectral lines were successfully explained in term of electron-transfer process between the excited sputtered atom and the solid surface. In this work, we have focused our study on the continuous radiation emitted during ion bombardment. The experimental results suggest that the continuum emission depends on the nature of metal and very probably related to its electronic structure. The collective deactivation of 3d-shell electrons appears to play a role in the emission of this radiation. The observed enhancement in the presence of oxygen is probably due to a significant contribution of the oxide molecules. (authors)

  7. On the cosmic microwave background radiation

    Directory of Open Access Journals (Sweden)

    José Maria Filardo Bassalo

    2017-12-01

    Full Text Available In this article we will try to give a pale idea to the reader of what could be the Cosmic Microwave Background (RCFM that, according to the traditional Big Bang model, was generated by a primordial explosion. With this purpose we find it very important to present a brief historical summary of how the Microcosm, based on the Standard Model of Elementary Particle Physics (MPPE, and the Macrocosm, based on the Standard Big Bang Model (MPBB, have evolved over time. In addition, in the final part of the article we will analyze the two physical processes presented in the literature that seek to explain the RCFM: Bariogenesis and Plasma Quark-Gluon.

  8. Cosmic microwave background radiation of black hole universe

    Science.gov (United States)

    Zhang, T. X.

    2010-11-01

    Modifying slightly the big bang theory, the author has recently developed a new cosmological model called black hole universe. This new cosmological model is consistent with the Mach principle, Einsteinian general theory of relativity, and observations of the universe. The origin, structure, evolution, and expansion of the black hole universe have been presented in the recent sequence of American Astronomical Society (AAS) meetings and published recently in a scientific journal: Progress in Physics. This paper explains the observed 2.725 K cosmic microwave background radiation of the black hole universe, which grew from a star-like black hole with several solar masses through a supermassive black hole with billions of solar masses to the present universe with hundred billion-trillions of solar masses. According to the black hole universe model, the observed cosmic microwave background radiation can be explained as the black body radiation of the black hole universe, which can be considered as an ideal black body. When a hot and dense star-like black hole accretes its ambient materials and merges with other black holes, it expands and cools down. A governing equation that expresses the possible thermal history of the black hole universe is derived from the Planck law of black body radiation and radiation energy conservation. The result obtained by solving the governing equation indicates that the radiation temperature of the present universe can be ˜2.725 K if the universe originated from a hot star-like black hole, and is therefore consistent with the observation of the cosmic microwave background radiation. A smaller or younger black hole universe usually cools down faster. The characteristics of the original star-like or supermassive black hole are not critical to the physical properties of the black hole universe at present, because matter and radiation are mainly from the outside space, i.e., the mother universe.

  9. Bill C-5, an act to amend the radiation emitting devices act

    International Nuclear Information System (INIS)

    1984-01-01

    This Act, entitled Bill C-5, allows for a series of amendments to the Radiation Emitting Devices Act. The amendments relate to regulations concerned with the sale, lease or import, labelling, advertising, packaging, safety standards and inspection of radiation emitting devices

  10. Microwave radiation safety assessment around mobile telephone base station (MTBS) in Peninsular Malaysia

    International Nuclear Information System (INIS)

    Mohd Yusof Mohd Ali; Rozaimah Abd Rahim; Roha Tukimin; Mohd Anuar Abd Majid; Mohamad Amirul Nizam Mohamad Thari; Ahmad Fazli Ahmad Sanusi; Roslan Md Dan; Sahirudden Mohd Nor

    2006-01-01

    Mobile telephone is one of the fastest popular consumer product introduced in the market. Since more people are using mobile telephone, the number of mobile telephone base station (MTBS) in Malaysia had also increased in order to provide a better coverage services to consumer. The antennas that are required for the mobile (or cellular) telephone network are located at MTBS. This antenna emits radio frequency (RF) and microwave (MW) radiation. Due to the concerns that has been raised by the people that are living or working nearby to MTBS about the possibility of adverse health effects that might occur due to the exposure of this radiation, a project of microwave radiation safety assessment around MTBS by MINT was carried out (September 2003 - January 2006). It was involved with 128 MTBS from three biggest service providers in Malaysia. This assessment is required to establish a baseline data in term of pattern and trend of the radiation emission from the facilities as well as to develop a public confident. In this paper, it will describe the fact that radiation is critical to the MTBS system and without the radiation, the MTBS system is functionless. It will also highlight the result of the assessment's work that has been carried out by MINT around MTBS mounted on the rooftops and towers. The average reading varies between the detection limit of the instrument 2 ( 2 (7.204 V/m). The highest average reading corresponds to about 2.0% of the Suruhanjaya Komunikasi dan Multimedia Malaysia (MCMC) exposure limit for public. The finding of this measurement confirms that the presence of RF and MW radiation in public accessible area around the base station was very low and comparable to the radiation levels in other places away from MTBS. There is also no evidence, from any laboratory or epidemiology studies that the exposure to RF energy levels recommended limits has any health significance for humans. (Author)

  11. Effects of microwave radiation on peripheral lymphocyte subpopulations in rats

    Directory of Open Access Journals (Sweden)

    Jin-ling YIN

    2011-10-01

    Full Text Available Objective To investigate the effects and mechanisms of microwave radiation on peripheral lymphocyte subpopulations in Wistar rats.Methods A total of 100 Wistar rats(180-220g were exposed to microwave with different average power densities of 5,10,30 and 60 mW/cm2,and sham exposure of 0mW/cm2 was performed in a control group at the same time.At day 1,7,14 and 28 after microwave irradiation,the changes in peripheral CD3+,CD4+,CD8+ T cells,ratio of CD4+/CD8+ and CD45RA+ B lymphocyte in rats were analyzed by flow cytometry(FCM.Results The CD3+ T cells decreased significantly in 10-30mW/cm2 groups at day 7 and in 5-30 mW/cm2 groups at day 14 after radiation as compared with control group(P < 0.05,and CD4+ T cells decreased significantly in 10mW/cm2 group at day 14 after radiation as compared with control group(P < 0.01.From day 1 to day 14 after radiation,CD8+ T cells showed a reduction in number in all irradiated groups when compared with the control,but statistical significance was only found in the 30mW/cm2 group(P < 0.05.The CD4+/CD8+ ratio increased in 5mW/cm2 group on day 1,while decreased significantly in 5-30mW/cm2 groups on day 14 after radiation as compared with control group(P < 0.05.After microwave exposure,however,CD45RA+ B cells in 30mW/cm2 group at day 1 and in 30-60mW/cm2 groups at day 14 after radiation increased significantly in a dose-dependent manner.Conclusion A definite dosage of microwave radiation,ranging from 5-60mW/cm2,may induce changes in subpopulations of peripheral lymphocytes and cause acute immune function impairment in rats.

  12. Could unstable relic particles distort the microwave background radiation?

    International Nuclear Information System (INIS)

    Dar, A.; Loeb, A.; Nussinov, S.

    1989-01-01

    Three general classes of possible scenarios for the recently reported distortion of the microwave background radiation (MBR) via decaying relic weakly interacting particles are analyzed. The analysis shows that such particles could not reheat the universe and cause the spectral distortion of the MBR. Gravitational processes such as the early formation of massive black holes may still be plausible energy sources for producing the reported spectral distortion of the MBR at an early cosmological epoch. 24 references

  13. Photolysis of low concentration H2S under UV/VUV irradiation emitted from microwave discharge electrodeless lamps.

    Science.gov (United States)

    Xia, Lan-Yan; Gu, Ding-Hong; Tan, Jing; Dong, Wen-Bo; Hou, Hui-Qi

    2008-04-01

    The photolysis of simulating low concentration of hydrogen sulfide malodorous gas was studied under UV irradiation emitted by self-made microwave discharge electrodeless lamps (i.e. microwave UV electrodeless mercury lamp (185/253.7 nm) and iodine lamp (178.3/180.1/183/184.4/187.6/206.2 nm)). Experiments results showed that the removal efficiency (eta H2S) of hydrogen sulfide was decreased with increasing initial H2S concentration and increased slightly with gas residence time; H2S removal efficiency was decreased dramatically with enlarged pipe diameter. Under the experimental conditions with pipe diameter of 36 mm, gas flow rate of 0.42 standard l s(-1), eta H2S was 52% with initial H2S concentration of 19.5 mg m(-3) by microwave mercury lamp, the absolute removal amount (ARA) was 4.30 microg s(-1), and energy yield (EY) was 77.3 mg kW h(-1); eta H2S was 56% with initial H2S concentration of 18.9 mg m(-3) by microwave iodine lamp, the ARA was 4.48 microg s(-1), and the EY was 80.5mg kW h(-1). The main photolysis product was confirmed to be SO4(2-) with IC.

  14. Cosmic microwave background radiation anisotropies in brane worlds.

    Science.gov (United States)

    Koyama, Kazuya

    2003-11-28

    We propose a new formulation to calculate the cosmic microwave background (CMB) spectrum in the Randall-Sundrum two-brane model based on recent progress in solving the bulk geometry using a low energy approximation. The evolution of the anisotropic stress imprinted on the brane by the 5D Weyl tensor is calculated. An impact of the dark radiation perturbation on the CMB spectrum is investigated in a simple model assuming an initially scale-invariant adiabatic perturbation. The dark radiation perturbation induces isocurvature perturbations, but the resultant spectrum can be quite different from the prediction of simple mixtures of adiabatic and isocurvature perturbations due to Weyl anisotropic stress.

  15. Measuring Radiofrequency and Microwave Radiation from Varying Signal Strengths

    Science.gov (United States)

    Davis, Bette; Gaul, W. C.

    2007-01-01

    This viewgraph presentation discusses the process of measuring radiofrequency and microwave radiation from various signal strengths. The topics include: 1) Limits and Guidelines; 2) Typical Variable Standard (IEEE) Frequency Dependent; 3) FCC Standard 47 CFR 1.1310; 4) Compliance Follows Unity Rule; 5) Multiple Sources Contribute; 6) Types of RF Signals; 7) Interfering Radiations; 8) Different Frequencies Different Powers; 9) Power Summing - Peak Power; 10) Contribution from Various Single Sources; 11) Total Power from Multiple Sources; 12) Are You Out of Compliance?; and 13) In Compliance.

  16. Effects upon health of occupational exposure to microwave radiation (radar)

    International Nuclear Information System (INIS)

    Robinette, C.D.; Silverman, C.; Jablon, S.

    1980-01-01

    The effects of occupational experience with microwave radiation (radar) on the health of US enlisted Naval personnel were studied in cohorts of approximately 20,000 men with maximum opportunity for exposure (electronic equipment repair) and 20,000 with minimum potential for exposure (equipment operation) who served during the Korean War period. Potential exposure was assessed in terms of occupational duties, length of time in occupation and power of equipment at the time of exposure. Actual exposure to members of each cohort could not be established. Mortality by cause of death, hospitalization during military service, later hospitalization in Veterans Administration (VA) facilities, and VA disability compensation were the health indexes studied, largely through the use of automated record systems. No adverse effects were detected in these indexes that could be attributed to potential microwave radiation exposures during the period 1950-1954. Functional and behavioral changes and ill-defined conditions, such as have been reported as microwave effects, could not be investigated in this study but subgroups of the living study population can be identified for expanded follow-up

  17. SMRT: A new, modular snow microwave radiative transfer model

    Science.gov (United States)

    Picard, Ghislain; Sandells, Melody; Löwe, Henning; Dumont, Marie; Essery, Richard; Floury, Nicolas; Kontu, Anna; Lemmetyinen, Juha; Maslanka, William; Mätzler, Christian; Morin, Samuel; Wiesmann, Andreas

    2017-04-01

    Forward models of radiative transfer processes are needed to interpret remote sensing data and derive measurements of snow properties such as snow mass. A key requirement and challenge for microwave emission and scattering models is an accurate description of the snow microstructure. The snow microwave radiative transfer model (SMRT) was designed to cater for potential future active and/or passive satellite missions and developed to improve understanding of how to parameterize snow microstructure. SMRT is implemented in Python and is modular to allow easy intercomparison of different theoretical approaches. Separate modules are included for the snow microstructure model, electromagnetic module, radiative transfer solver, substrate, interface reflectivities, atmosphere and permittivities. An object-oriented approach is used with carefully specified exchanges between modules to allow future extensibility i.e. without constraining the parameter list requirements. This presentation illustrates the capabilities of SMRT. At present, five different snow microstructure models have been implemented, and direct insertion of the autocorrelation function from microtomography data is also foreseen with SMRT. Three electromagnetic modules are currently available. While DMRT-QCA and Rayleigh models need specific microstructure models, the Improved Born Approximation may be used with any microstructure representation. A discrete ordinates approach with stream connection is used to solve the radiative transfer equations, although future inclusion of 6-flux and 2-flux solvers are envisioned. Wrappers have been included to allow existing microwave emission models (MEMLS, HUT, DMRT-QMS) to be run with the same inputs and minimal extra code (2 lines). Comparisons between theoretical approaches will be shown, and evaluation against field experiments in the frequency range 5-150 GHz. SMRT is simple and elegant to use whilst providing a framework for future development within the

  18. Generalized Chaplygin gas and cosmic microwave background radiation constraints

    International Nuclear Information System (INIS)

    Bento, M.C.; Bertolami, O.; Sen, A.A.

    2003-01-01

    We study the dependence of the location of the cosmic microwave background radiation peaks on the parameters of the generalized Chaplygin gas model, whose equation of state is given by p=-A/ρ α , where A is a positive constant and 0<α≤1. We find, in particular, that observational data arising from Archeops, BOOMERANG, supernova and high-redshift observations allow constraining significantly the parameter space of the model. Our analysis indicates that the emerging model is clearly distinguishable from the α=1 Chaplygin case and the ΛCDM model

  19. Engineering squeezed states of microwave radiation with circuit quantum electrodynamics

    International Nuclear Information System (INIS)

    Li Pengbo; Li Fuli

    2011-01-01

    We introduce a squeezed state source for microwave radiation with tunable parameters in circuit quantum electrodynamics. We show that when a superconducting artificial multilevel atom interacting with a transmission line resonator is suitably driven by external classical fields, two-mode squeezed states of the cavity modes can be engineered in a controllable fashion from the vacuum state via adiabatic following of the ground state of the system. This scheme appears to be robust against decoherence and is realizable with present techniques in circuit quantum electrodynamics.

  20. A passive and active microwave-vector radiative transfer (PAM-VRT) model

    International Nuclear Information System (INIS)

    Yang, Jun; Min, Qilong

    2015-01-01

    A passive and active microwave vector radiative transfer (PAM-VRT) package has been developed. This fast and accurate forward microwave model, with flexible and versatile input and output components, self-consistently and realistically simulates measurements/radiation of passive and active microwave sensors. The core PAM-VRT, microwave radiative transfer model, consists of five modules: gas absorption (two line-by-line databases and four fast models); hydrometeor property of water droplets and ice (spherical and nonspherical) particles; surface emissivity (from Community Radiative Transfer Model (CRTM)); vector radiative transfer of successive order of scattering (VSOS); and passive and active microwave simulation. The PAM-VRT package has been validated against other existing models, demonstrating good accuracy. The PAM-VRT not only can be used to simulate or assimilate measurements of existing microwave sensors, but also can be used to simulate observation results at some new microwave sensors. - Highlights: • A novel microwave vector radiative transfer model is developed. • It can simulate passive and active microwave radiative transfer simultaneously. • It can be applied to simulate measurements for different types of viewing geometry. • The accuracy of this model has been validated against other existing models

  1. Short-duration exposure to 2.45 GHz microwave radiation induces ...

    African Journals Online (AJOL)

    OBEMBE

    The genotoxic effects of 2.45 GHz microwave (MW) radiation on the testis ... electromagnetic radiation present in the environment and ..... intrinsic (quantum) energy is too low to dislodge an .... wave on brain enzymes of developing rat brain.

  2. The local contribution to the microwave background radiation

    International Nuclear Information System (INIS)

    Pecker, Jean-Claude; Narlikar, Jayant V.; Ochsenbein, Francois; Wickramasinghe, Chandra

    2015-01-01

    The observed microwave background radiation (MBR) is commonly interpreted as the relic of an early hot universe, and its observed features (spectrum and anisotropy) are explained in terms of properties of the early universe. Here we describe a complementary, even possibly alternative, interpretation of MBR, first proposed in the early 20 th century, and adapt it to modern observations. For example, the stellar Hipparcos data show that the energy density of starlight from the Milky Way, if suitably thermalized, yields a temperature of ∼2.81 K. This and other arguments given here strongly suggest that the origin of MBR may lie, at least in a very large part, in re-radiation of thermalized galactic starlight. The strengths and weaknesses of this alternative radical explanation are discussed. (paper)

  3. 21 CFR 179.30 - Radiofrequency radiation for the heating of food, including microwave frequencies.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Radiofrequency radiation for the heating of food... PRODUCTION, PROCESSING AND HANDLING OF FOOD Radiation and Radiation Sources § 179.30 Radiofrequency radiation for the heating of food, including microwave frequencies. Radiofrequency radiation, including...

  4. Estimating the Infrared Radiation Wavelength Emitted by a Remote Control Device Using a Digital Camera

    Science.gov (United States)

    Catelli, Francisco; Giovannini, Odilon; Bolzan, Vicente Dall Agnol

    2011-01-01

    The interference fringes produced by a diffraction grating illuminated with radiation from a TV remote control and a red laser beam are, simultaneously, captured by a digital camera. Based on an image with two interference patterns, an estimate of the infrared radiation wavelength emitted by a TV remote control is made. (Contains 4 figures.)

  5. The impact of microwave stray radiation to in-vessel diagnostic components

    Energy Technology Data Exchange (ETDEWEB)

    Hirsch, M.; Laqua, H. P.; Hathiramani, D.; Baldzuhn, J.; Biedermann, C.; Cardella, A.; Erckmann, V.; König, R.; Köppen, M.; Zhang, D. [Max-Planck-Institut für Plasmaphysik, Teilinstitut Greifswald, EURATOM Association, D-17489 Greifswald (Germany); Oosterbeek, J.; Brand, H. von der; Parquay, S. [Technische Universiteit Eindhoven, department Technische Natuurkunde, working group for Plasma Physics and Radiation Technology, Den Doelch 2, 5612 AZ Eindhoven (Netherlands); Jimenez, R. [Centro de Investigationes Energeticas, Medioambientales y Technológicas, Association EURATOM/CIEMAT, Avenida Complutense 22, Madrid 28040 (Spain); Collaboration: W7-X Teasm

    2014-08-21

    Microwave stray radiation resulting from unabsorbed multiple reflected ECRH / ECCD beams may cause severe heating of microwave absorbing in-vessel components such as gaskets, bellows, windows, ceramics and cable insulations. In view of long-pulse operation of WENDELSTEIN-7X the MIcrowave STray RAdiation Launch facility, MISTRAL, allows to test in-vessel components in the environment of isotropic 140 GHz microwave radiation at power load of up to 50 kW/m{sup 2} over 30 min. The results show that both, sufficient microwave shielding measures and cooling of all components are mandatory. If shielding/cooling measures of in-vessel diagnostic components are not efficient enough, the level of stray radiation may be (locally) reduced by dedicated absorbing ceramic coatings on cooled structures.

  6. Interaction of ultrahigh energy cosmic rays with microwave background radiation

    International Nuclear Information System (INIS)

    Aharonyan, F.A.; Kanevskij, B.L.; Vardanyan, V.V.

    1989-01-01

    The formation of the bump and black-body cutoff in the cosmic-ray (CR) spectrum arising from the π-meson photoproduction reaction in collisions of CR protons with the microwave background radiation (MBR) photons is studied. A kinetic equation which describes CR proton propagation in MBR with account of a catastrophic of the π-meson photoproduction process is derived. The equilibrium CR proton spectrum obtained from the solution of the stationary kinetic equation is in general agreement with spectrum obtained under assumption of continuous energy loss approximation. However spectra from local sources especially for the times of propagation t>10 9 years differ noticeably from those obtained in the continuous loss approximation. 24 refs.; 5 figs

  7. On the anisotropies of cosmic microwave background radiation

    International Nuclear Information System (INIS)

    Molnar, Z.

    1996-01-01

    The work gives a brief overview of the topic of cosmic microwave background radiation anisotropies. Then is deals with the so-called Rees-Sciama affect; i.e. with the anisotropies arising between the last scattering surface and us due to transparent huge irregularities. Using the formulas of Special Theory of Relativity it is proven that in the neighbourhood of expanding spherical body the Meszaros calculation (Meszaros 1994) are correct; the inaccuracy is maximally of order 10 -12 . Then the profile of the blue shift of expansion caused by an expanding sphere is calculated for the case, when the radius of this sphere is much smaller that the relevant Hubble radius. Hence the profiles of the shifts of light periods through a void and through a supercluster are given in the most general cases. These cases contain all the three Friedmannian models and both the synchronous and asynchronous clusters. Then the obtained profiles are explicitly decomposed into the sum of the multipole terms, and it is shown that the observed difference between the measured direction of the maximum of dipole anisotropy of cosmic microwave background radiation and the result of Lauer and Postman (1994) is not explainable by the Rees-Sciama effect. This means that no alternative exists to the two possibilities for the explanation of the data of Lauer and Postman; either the either the huge system of Abell clusters is streaming, or the Friedmannian model is queried. The third possibility is, of course, that the data of observations of Lauer and Postman are incorrect. However, any of these three possibilities seem to be strange enough; hence, the problems coming from data of Lauer and Postman further holds. This is the key result of paper. As a further technical result it is also shown that in principle there is no upper limit of Rees-Sciama effect. (author)

  8. Occupational exposure to microwave radiation in diathermia units

    International Nuclear Information System (INIS)

    Martinez, M.A.; Ubeda, A.; Tellez, M.; Santa Olalla, I.

    2006-01-01

    The present study summarizes preliminary data addressed to complete the present knowledge on the microwave (M.V.)-exposure doses and conditions in workers exposed chronically to relatively high, though nonthermal, levels of that non ionizing radiations (N.I.R.). The obtained data are of direct application to radiation protection in occupational media provided that: 1) help to detect and eradicate practices and situations that result in overexposure; 2) they constitute a basis for the design and development of strategies for exposure control and minimization, and 3) they represent a dosimetric support necessary to properly interpret past and future epidemiologic and experimental data on potential health effects of chronic exposures to M.W. radiation at work. The described results will be extended through additional dosimetric recordings in other hospitals. The dosimetric data will be compared to the results of questionnaires among the electro-therapists working at the units studied. The objective is to identify potential relationships between exposure doses and specific diseases or level of risk perception among the investigated professional group. (authors)

  9. Occupational exposure to microwave radiation in diathermia units

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, M.A.; Ubeda, A. [Hospital Ramon y Cajal, Servicio de Investigacion-BEM, Madrid (Spain); Tellez, M.; Santa Olalla, I. [Hospital La Paz, Servicio de Radiofisica y Radioproteccion, Madrid (Spain)

    2006-07-01

    The present study summarizes preliminary data addressed to complete the present knowledge on the microwave (M.V.)-exposure doses and conditions in workers exposed chronically to relatively high, though nonthermal, levels of that non ionizing radiations (N.I.R.). The obtained data are of direct application to radiation protection in occupational media provided that: 1) help to detect and eradicate practices and situations that result in overexposure; 2) they constitute a basis for the design and development of strategies for exposure control and minimization, and 3) they represent a dosimetric support necessary to properly interpret past and future epidemiologic and experimental data on potential health effects of chronic exposures to M.W. radiation at work. The described results will be extended through additional dosimetric recordings in other hospitals. The dosimetric data will be compared to the results of questionnaires among the electro-therapists working at the units studied. The objective is to identify potential relationships between exposure doses and specific diseases or level of risk perception among the investigated professional group. (authors)

  10. RADIOFREQUENCY AND MICROWAVE RADIATION HEALTH EFFECTS AND OCCUPATIONAL EXPOSURE

    Directory of Open Access Journals (Sweden)

    Ivana Damnjanović

    2011-12-01

    Full Text Available In the recent years, there have been considerable discussion and concern about the possible hazards of RF/MW radiation. More recently, the growth and development in personal mobile communications have focused attention on the frequencies associated with this technology. A number of studies have examined the health effects of RF/MW electromagnetic fields (EMFs, originating from occupational exposure, hobbies, or residence near the radio or television transmitters. Particularly controversial are the biophysical mechanisms by which these RF fields may affect biological systems. General health effects reviews explore possible carcinogenic, reproductive and neurological effects. Health effects by exposure source have been observed in radar traffic devices, wireless communications with cellular phones, radio transmission, and magnetic resonance imaging (MRI. Several epidemiological surveys have suggested associations with non-specific complaints such as headache, tiredness, sleep disturbance, loss of memory, and dizziness. These findings, which echo reports of illness associated with other types of radiofrequency (RF radiation, relate not only to the use of mobile phones, but also to residence near the mobile phone base stations and other settings involving occupational exposure. The biological effects suggest that some precautions are necessary, and preventive approaches are highly recommended. Further researches are required to give more information about the effects of microwave radiation on our health, especially in occupational setting and professionally exposed workers.

  11. The Local Contribution to the Microwave Background Radiation(MBR)

    Science.gov (United States)

    Narlikar, Jayant V.; Pecker, Jean-Claude; Wickramasinghe, N. Ch.

    2010-11-01

    In the early fifties, from the early theories of the big bang universe, Gamow, Alpher & Herman have predicted the existence of a "cosmological" microwave background radiation, corresponding to a black body of a few Kelvins. When, in 1964, Penzias & Wilson, observed a radiation at 2.7K, the scientific world concluded quickly it was a proof, a final proof, of the big bang type cosmologies. But it should be realized that, in the beginning of the XX-th century, several authors, from Guillaume to Eddington, have predicted the same thing in a static Universe. We have redone the calculations of Eddington, and based them on the recent and very accurate photometric results from the satellite Hipparcos. In the absence of any expansion, of any big bang type behaviour, we compute the local temperature induced by the reradiation by local matter of stellar radiation, and we found it to be in excellent agreement with the observations. This result, completed by a careful discussion, could lead to a dramatic revision of the classical cosmological concepts.

  12. an assessment of ultraviolet radiation components of light emitted ...

    African Journals Online (AJOL)

    Dr

    therefore high for exposure limits of 8 hours for UV-B and UV-C and the 16 minutes for UV-A. The investigation ... has become particularly interesting as the ozone layer ... THEORY. Ultraviolet (UV) light is an electromagnetic radiation with a ...

  13. Non-radiative recombination losses in polymer light-emitting diodes

    NARCIS (Netherlands)

    Kuik, M.; Koster, L. J. A.; Dijkstra, A. G.; Wetzelaer, G. A. H.; Blom, P. W. M.

    We present a quantitative analysis of the loss of electroluminescence in light-emitting diodes (LEDs) based on poly[2-methoxy-5-(2'-ethylhexyloxy)-p-phenylenevinylene] (MEH-PPV) due to the combination of non-radiative trap-assisted recombination and exciton quenching at the metallic cathode. It is

  14. Geometric radiation exchange factors for axial radiative transfer in an LWR core filled with absorbing-emitting gases

    International Nuclear Information System (INIS)

    Chan, S.H.; Cho, D.H.

    1984-01-01

    A reactor core filled with an emitting-absorbing mixture (like steam, hydrogen gas and fission gases) is considered. Analysis is provided to evaluate axial radiative heat exchange of a rod bundle with a nonuniform axial temperature distribution. The necessary radiation exchange shape factors (geometric mean absorptance, emittance and transmittance) between segments of the complex rod bundle arrangement are presented. They are applicable to arbitrary sizes of segments, well suited for numerical computations

  15. Rapid and controllable perforation of carbon nanotubes by microwave radiation

    Science.gov (United States)

    Ojaghi, Neda; Mokhtarifar, Maryam; Sabaghian, Zahra; Arab, Hamed; Maghrebi, Morteza; Baniadam, Majid

    2018-05-01

    This study presents a new controlled approach to deep perforation of millimeter-long carbon nanotube arrays (CNTAs) by fast oxidative cutting. The approach is based on decorating CNTAs with silver (Ag) nanoparticles, followed by heating Ag-decorated CNTAs with microwave radiation (2.48 GHz, 300 W). The perforation was evaluated using different techniques such as transmission electron microscopy, X-ray photoelectron spectroscopy, and Brunauer-Emmett-Teller method. The results of the oxidation of carbonaceous materials indicated that the relative amount of oxygen functional groups increased without total oxidation of carbon up to 60 s. After 60 s, the amount of functional groups decreased as the total oxidation started suddenly. Afterwards, at around 120 and 420 s, the oxidation of Ag-decorated CNTAs reached the point of total perforation and total cutting, respectively. Though carbon decomposition terminated at around 420 s, the total pore volume and surface area increased continuously. This was attributed to the steady growth of Ag nanoparticles located between CNTAs.

  16. Imprints of relic gravitational waves in cosmic microwave background radiation

    International Nuclear Information System (INIS)

    Baskaran, D.; Grishchuk, L. P.; Polnarev, A. G.

    2006-01-01

    A strong variable gravitational field of the very early Universe inevitably generates relic gravitational waves by amplifying their zero-point quantum oscillations. We begin our discussion by contrasting the concepts of relic gravitational waves and inflationary 'tensor modes'. We explain and summarize the properties of relic gravitational waves that are needed to derive their effects on cosmic microwave background (CMB) temperature and polarization anisotropies. The radiation field is characterized by four invariants I, V, E, B. We reduce the radiative transfer equations to a single integral equation of Voltairre type and solve it analytically and numerically. We formulate the correlation functions C l XX ' for X, X ' =T, E, B and derive their amplitudes, shapes and oscillatory features. Although all of our main conclusions are supported by exact numerical calculations, we obtain them, in effect, analytically by developing and using accurate approximations. We show that the TE correlation at lower l's must be negative (i.e. an anticorrelation), if it is caused by gravitational waves, and positive if it is caused by density perturbations. This difference in TE correlation may be a signature more valuable observationally than the lack or presence of the BB correlation, since the TE signal is about 100 times stronger than the expected BB signal. We discuss the detection by WMAP of the TE anticorrelation at l≅30 and show that such an anticorrelation is possible only in the presence of a significant amount of relic gravitational waves (within the framework of all other common assumptions). We propose models containing considerable amounts of relic gravitational waves that are consistent with the measured TT, TE and EE correlations

  17. Ground penetrating radar using a microwave radiated from laser-induced plasma

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, H; Tanaka, K A [Graduate School of Engineering and Institute of Laser Engineering, Suita, Osaka University (Japan); Yamaura, M; Shimada, Y; Fujita, M [Institute for Laser Technology, Suita, Osaka (Japan)], E-mail: nakajima-h@ile.osaka-u.ac.jp

    2008-05-01

    A plasma column radiates a microwave to surroundings when generated with laser irradiation. Using such a microwave, we are able to survey underground objects and architectures from a remote place. In this paper, the microwave radiated from a plasma column induced by an intense laser ({approx} 10{sup 9} W/cm{sup 2}) were measured. Additionally, a proof test of this method was performed by searching an underground aluminum disk (26 cm in diameter, 1 cm in depth, and 1 m apart from a receiving antenna). As the result, the characteristics of the radiated microwave were clarified, and strong echoes corresponding to the edges of an aluminum disk were found. Based on these results, the feasibility of a ground penetrating radar was verified.

  18. Optical radiation emitted by a silver surface bombarded by low-energy electrons

    International Nuclear Information System (INIS)

    Miserey, F.; Lebon, P.; Septier, A.; Trehin, F.; Beaugrand, C.

    1975-01-01

    Thick silver targets are obtained on flat glass discs by evaporation in a UHV cell (p -10 torr) and their optical coefficients measured by ellipsometry. A field-emission electron gun bombards a limited region of the target, corresponding to the entry pupil of a light spectrometer. Radiation emitted in the domain 250-600nm is analyzed for both normal and parallel polarizations. Spectral distributions of photons are obtained by using a very sensitive counting device including a multi channel analyzer. First experimental results concerning optical radiation generated by 6keV electrons are reported and compared to Transition Radiation and Bremsstrahlung theoretical spectra [fr

  19. [Level of microwave radiation from mobile phone base stations built in residential districts].

    Science.gov (United States)

    Hu, Ji; Lu, Yiyang; Zhang, Huacheng; Xie, Hebing; Yang, Xinwen

    2009-11-01

    To investigate the condition of microwave radiation pollution from mobile phone base station built in populated area. Random selected 18 residential districts where had base station and 10 residential districts where had no base stations. A TES-92 electromagnetic radiation monitor were used to measure the intensity of microwave radiation in external and internal living environment. The intensities of microwave radiation in the exposure residential districts were more higher than those of the control residential districts (p station, it would gradually weaken with the increase of the distance. The level of microwave radiation in antenna main lobe region is not certainly more higher than the side lobe direction, and the side lobe direction also is not more lower. At the same district, where there were two base stations, the electromagnetic field nestification would take place in someplace. The intensities of microwave radiation outside the exposure windows in the resident room not only changed with distance but also with the height of the floor. The intensities of microwave radiation inside the aluminum alloys security net were more lower than those of outside the aluminum alloys security net (p 0.05). Although all the measure dates on the ground around the base station could be below the primary standard in "environment electromagnetic wave hygienic standard" (GB9175-88), there were still a minorities of windows which exposed to the base station were higher, and the outside or inside of a few window was even higher beyond the primary safe level defined standard. The aluminum alloys security net can partly shield the microwave radiation from the mobile phone base station.

  20. Loads due to stray microwave radiation in ITER

    Energy Technology Data Exchange (ETDEWEB)

    Oosterbeek, Johan W. [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St. Paul Lez Durance Cedex (France); Eindhoven University of Technology, P.O. Box 513, 5600 AZ Eindhoven (Netherlands); Udintsev, Victor S.; Gandini, Franco [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St. Paul Lez Durance Cedex (France); Hirsch, Matthias; Laqua, Heinrich P. [Max-Planck-Institut für Plasmaphysik, EURATOM Association, Teilinstitut Greifswald, D-17489 Greifswald (Germany); Maassen, Nick [Eindhoven University of Technology, P.O. Box 513, 5600 AZ Eindhoven (Netherlands); Ma, Yunxing; Polevoi, Alexei; Sirinelli, Antoine; Vayakis, George; Walsh, Mike J. [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St. Paul Lez Durance Cedex (France)

    2015-10-15

    High-power microwaves generated by gyrotrons will be extensively used in ITER for a variety of purposes such as assisting plasma breakdown, plasma heating, current drive, tearing mode suppression and as a probing beam for the Collective Thomson Scattering diagnostic. In a number of these schemes absorption of the microwaves by the plasma will not be full and in some cases there could be no absorption at all. This may result in a directed beam with a high microwave power flux or – depending on location and plasma conditions – an approximately isotropic microwave power field. The contribution of electron cyclotron emission to these power densities is briefly discussed. Exposure to in-vessel components leads to absorption by metals and ceramics. In this paper microwave power densities are estimated and, following a brief review of absorption, thermal loads on in-vessel components are assessed. The paper is concluded by a discussion of the current approach to control such loads.

  1. On the radiative and thermodynamic properties of the cosmic radiations using COBE FIRAS instrument data: I. Cosmic microwave background radiation

    Science.gov (United States)

    Fisenko, Anatoliy I.; Lemberg, Vladimir

    2014-07-01

    Using the explicit form of the functions to describe the monopole and dipole spectra of the Cosmic Microwave Background (CMB) radiation, the exact expressions for the temperature dependences of the radiative and thermodynamic functions, such as the total radiation power per unit area, total energy density, number density of photons, Helmholtz free energy density, entropy density, heat capacity at constant volume, and pressure in the finite range of frequencies v 1≤ v≤ v 2 are obtained. Since the dependence of temperature upon the redshift z is known, the obtained expressions can be simply presented in z representation. Utilizing experimental data for the monopole and dipole spectra measured by the COBE FIRAS instrument in the 60-600 GHz frequency interval at the temperature T=2.72548 K, the values of the radiative and thermodynamic functions, as well as the radiation density constant a and the Stefan-Boltzmann constant σ are calculated. In the case of the dipole spectrum, the constants a and σ, and the radiative and thermodynamic properties of the CMB radiation are obtained using the mean amplitude T amp=3.358 mK. It is shown that the Doppler shift leads to a renormalization of the radiation density constant a, the Stefan-Boltzmann constant σ, and the corresponding constants for the thermodynamic functions. The expressions for new astrophysical parameters, such as the entropy density/Boltzmann constant, and number density of CMB photons are obtained. The radiative and thermodynamic properties of the Cosmic Microwave Background radiation for the monopole and dipole spectra at redshift z≈1089 are calculated.

  2. Optical emission spectroscopy for quantification of ultraviolet radiations and biocide active species in microwave argon plasma jet at atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Wattieaux, G., E-mail: gaetan.wattieaux@laplace.univ-tlse.fr; Yousfi, M.; Merbahi, N.

    2013-11-01

    This work deals with absorption and mainly emission spectrometry of a microwave induced surfatron plasma jet launched in ambient air and using an Argon flow carrier gas. The Ar flow rate varies between 1 and 3 L/min and the microwave power between 40 and 60 W. The analysis of the various spectra has led to the determination of the ozone and atomic oxygen concentrations, ultraviolet (UV) irradiance separating UVA, UVB and UVC, gas temperature, plasma electron density and excitation temperature. Most of these diagnostics are spatially resolved along the plasma jet axis. It is shown more particularly that rotational temperature obtained from OH(A-X) spectra ranges between 800 K to 1000 K while the apparent temperature of the plasma jet remains lower than about 325 K which is compatible with biocide treatment without significant thermal effect. The electron density reaches 1.2 × 10{sup 14} cm{sup −3}, the excitation temperature is about 4000 K, the UVC radiation represents only 5% of the UV radiations emitted by the device, the ozone concentration is found to reach 88 ± 27 ppm in the downstream part of the plasma jet at a distance of 30 mm away from the quartz tube outlet of the surfatron and the atomic oxygen concentration lies between 10 and 80 ppm up to a distance of 20 mm away from the quartz tube outlet. Ozone is identified as the main germicidal active species produced by the device since its concentration is in accordance with bacteria inactivation durations usually reported using such plasma devices. Human health hazard assessment is carried out all along this study since simple solutions are reminded to respect safety standards for exposures to ozone and microwave leakage. In this study, an air extraction unit is used and a Faraday cage is set around the quartz tube of the surfatron and the plasma jet. These solutions should be adopted by users of microwave induced plasma in open air conditions because according to the literature, this is not often the

  3. Optical emission spectroscopy for quantification of ultraviolet radiations and biocide active species in microwave argon plasma jet at atmospheric pressure

    International Nuclear Information System (INIS)

    Wattieaux, G.; Yousfi, M.; Merbahi, N.

    2013-01-01

    This work deals with absorption and mainly emission spectrometry of a microwave induced surfatron plasma jet launched in ambient air and using an Argon flow carrier gas. The Ar flow rate varies between 1 and 3 L/min and the microwave power between 40 and 60 W. The analysis of the various spectra has led to the determination of the ozone and atomic oxygen concentrations, ultraviolet (UV) irradiance separating UVA, UVB and UVC, gas temperature, plasma electron density and excitation temperature. Most of these diagnostics are spatially resolved along the plasma jet axis. It is shown more particularly that rotational temperature obtained from OH(A-X) spectra ranges between 800 K to 1000 K while the apparent temperature of the plasma jet remains lower than about 325 K which is compatible with biocide treatment without significant thermal effect. The electron density reaches 1.2 × 10 14 cm −3 , the excitation temperature is about 4000 K, the UVC radiation represents only 5% of the UV radiations emitted by the device, the ozone concentration is found to reach 88 ± 27 ppm in the downstream part of the plasma jet at a distance of 30 mm away from the quartz tube outlet of the surfatron and the atomic oxygen concentration lies between 10 and 80 ppm up to a distance of 20 mm away from the quartz tube outlet. Ozone is identified as the main germicidal active species produced by the device since its concentration is in accordance with bacteria inactivation durations usually reported using such plasma devices. Human health hazard assessment is carried out all along this study since simple solutions are reminded to respect safety standards for exposures to ozone and microwave leakage. In this study, an air extraction unit is used and a Faraday cage is set around the quartz tube of the surfatron and the plasma jet. These solutions should be adopted by users of microwave induced plasma in open air conditions because according to the literature, this is not often the case

  4. Medical preparation container comprising microwave powered sensor assembly

    DEFF Research Database (Denmark)

    2016-01-01

    The present invention relates to a medical preparation container which comprises a microwave powered sensor assembly. The microwave powered sensor assembly comprises a sensor configured to measure a physical property or chemical property of a medical preparation during its heating in a microwave ...... oven. The microwave powered sensor assembly is configured for harvesting energy from microwave radiation emitted by the microwave oven and energize the sensor by the harvested microwave energy.......The present invention relates to a medical preparation container which comprises a microwave powered sensor assembly. The microwave powered sensor assembly comprises a sensor configured to measure a physical property or chemical property of a medical preparation during its heating in a microwave...

  5. Assessment of DNA sensitivity in peripheral blood leukocytes after occupational exposure to microwave radiation: the alkaline comet assay and chromatid breakage assay

    International Nuclear Information System (INIS)

    Garaj-Vrhovac, V.; Kopjar, N.

    2002-01-01

    The people of industrialised societies are continuously exposed to increasing levels of electromagnetic fields (EMF) emitted by various electrical installations and telecommunication systems. In recent years there has been growing interest in the health effects of the electromagnetic radiation's designated extremely low frequency (ELF) and radiofrequency radiation (RFR). It is known that exposure to microwave radiation has different biological effects on eye, the nervous system and its function, circulatory and the reproductive system. Available data on cytogenetic consequences of microwave exposure on the induction of chromosome damage are sometimes contradictory, mostly because of different experimental conditions of in vitro and in vivo studies. However, in occupationally exposed persons elevated levels of DNA damage as expressed by means of cytogenetic endpoints were observed. Positive results in induction of micronuclei are also reported after in vitro exposure to microwave radiation on human lymphocytes. It has been suggested that exposure to radiofrequency radiation may have genetic effects which predispose to the development of cancer, particularly lymphoma and leukaemia, and also birth defects such as Down's syndrome

  6. Low intensity microwave radiation induced oxidative stress, inflammatory response and DNA damage in rat brain.

    Science.gov (United States)

    Megha, Kanu; Deshmukh, Pravin Suryakantrao; Banerjee, Basu Dev; Tripathi, Ashok Kumar; Ahmed, Rafat; Abegaonkar, Mahesh Pandurang

    2015-12-01

    Over the past decade people have been constantly exposed to microwave radiation mainly from wireless communication devices used in day to day life. Therefore, the concerns over potential adverse effects of microwave radiation on human health are increasing. Until now no study has been proposed to investigate the underlying causes of genotoxic effects induced by low intensity microwave exposure. Thus, the present study was undertaken to determine the influence of low intensity microwave radiation on oxidative stress, inflammatory response and DNA damage in rat brain. The study was carried out on 24 male Fischer 344 rats, randomly divided into four groups (n=6 in each group): group I consisted of sham exposed (control) rats, group II-IV consisted of rats exposed to microwave radiation at frequencies 900, 1800 and 2450 MHz, specific absorption rates (SARs) 0.59, 0.58 and 0.66 mW/kg, respectively in gigahertz transverse electromagnetic (GTEM) cell for 60 days (2h/day, 5 days/week). Rats were sacrificed and decapitated to isolate hippocampus at the end of the exposure duration. Low intensity microwave exposure resulted in a frequency dependent significant increase in oxidative stress markers viz. malondialdehyde (MDA), protein carbonyl (PCO) and catalase (CAT) in microwave exposed groups in comparison to sham exposed group (pmicrowave exposed groups (pmicrowave exposed animal (pmicrowave exposed groups as compared to their corresponding values in sham exposed group (pmicrowave radiation induces oxidative stress, inflammatory response and DNA damage in brain by exerting a frequency dependent effect. The study also indicates that increased oxidative stress and inflammatory response might be the factors involved in DNA damage following low intensity microwave exposure. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Neutron emission from 9Be nucleus under the action of β+ and γ radiation emitted in radioactive decay

    International Nuclear Information System (INIS)

    Vo Dak Bang; Gangrskij, Yu.P.; Miller, M.B.; Mikhajlov, L.V.; Fam Zui Khien; Kharisov, I.F.

    1980-01-01

    The neutron yield from the 9 Be nucleus under the action of beta and gamma-radiation emitted at the radiative decay of 11 C, 62 Cu, 66 Ga, 74 Br isotopes is measured. These isotopes differ essentially by the emitted radiation spectra. The contribution of various processes ((γ, n)-reactions, inelastic scattering and positron nonradiative annihilation) to the neutron yield observed is determined [ru

  8. A flat Universe from high-resolution maps of the cosmic microwave background radiation

    Science.gov (United States)

    de Bernardis P; Ade; Bock; Bond; Borrill; Boscaleri; Coble; Crill; De Gasperis G; Farese; Ferreira; Ganga; Giacometti; Hivon; Hristov; Iacoangeli; Jaffe; Lange; Martinis; Masi; Mason; Mauskopf; Melchiorri; Miglio; Montroy; Netterfield

    2000-04-27

    The blackbody radiation left over from the Big Bang has been transformed by the expansion of the Universe into the nearly isotropic 2.73 K cosmic microwave background. Tiny inhomogeneities in the early Universe left their imprint on the microwave background in the form of small anisotropies in its temperature. These anisotropies contain information about basic cosmological parameters, particularly the total energy density and curvature of the Universe. Here we report the first images of resolved structure in the microwave background anisotropies over a significant part of the sky. Maps at four frequencies clearly distinguish the microwave background from foreground emission. We compute the angular power spectrum of the microwave background, and find a peak at Legendre multipole Ipeak = (197 +/- 6), with an amplitude delta T200 = (69 +/- 8) microK. This is consistent with that expected for cold dark matter models in a flat (euclidean) Universe, as favoured by standard inflationary models.

  9. Microwave engineering

    CERN Document Server

    Pozar, David M

    2012-01-01

    The 4th edition of this classic text provides a thorough coverage of RF and microwave engineering concepts, starting from fundamental principles of electrical engineering, with applications to microwave circuits and devices of practical importance.  Coverage includes microwave network analysis, impedance matching, directional couplers and hybrids, microwave filters, ferrite devices, noise, nonlinear effects, and the design of microwave oscillators, amplifiers, and mixers. Material on microwave and RF systems includes wireless communications, radar, radiometry, and radiation hazards. A large

  10. Correlation of electromagnetic radiation emitted from coal or rock to supporting resistance

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Hui-lin; Wang, En-yuan; Song, Xiao-yan; Zhang, Hong-jie; Li, Zhong-hui [China University of Mining & Technology, Xuzhou (China). School of Safety Engineering

    2009-05-15

    More accurate forecasting of rock burst might be possible from observations of electromagnetic radiation emitted in the mine. We analyzed experimental observations and field data from the Muchengjian coal mine to study the relationship between electromagnetic radiation signal intensity and stress during the fracturing of coal, or rock, and samples under load. The results show that the signal intensity is positively correlated with stress. In addition, we investigated the change in the electromagnetic radiation intensity, the supporting resistance in a real coal mine environment, and the coal or rock stress in the mining area. The data analysis indicates that: (1) electromagnetic radiation intensity can accurately reflect the distribution of stress in the mining area; and, (2) there is a correlation between electromagnetic radiation intensity and supporting resistance. The research has some practical guiding significance for rock burst forecasting and for the prevention of accidents in coal mines. 9 refs., 6 figs.

  11. Detection of microwave radiation of cytochrome CYP102 A1 solution during the enzyme reaction

    Directory of Open Access Journals (Sweden)

    Yu.D. Ivanov

    2016-03-01

    Full Text Available Microwave radiation at 3.4–4.2 GHz frequency of the cytochrome P450 CYP102 A1 (BM3 solution was registered during the lauric acid hydroxylation reaction. The microwave radiation generation was shown to occur following the addition of electron donor NADPH to a system containing an enzyme and a substrate. The radiation occurs for the enzyme solutions with enzyme concentrations of 10−8 and 10−9 М. The microwave radiation effect elicited by the aqueous enzyme solution was observed for the first time. The results obtained can be used to elaborate a new approach to enzyme systems research, including studying of the mechanism of interaction of a functioning enzyme system with microenvironment.

  12. Effect of Gamma Radiation and Microwave Cooking on Aeromonas Hydrophila in Bolti Fish Fillet

    International Nuclear Information System (INIS)

    Mohamad, W.S.; Megahed, A.A.; El-Ghaiaty, H.A.; Hafez, T.A.

    2016-01-01

    The objective of this study is to determine the bactericidal effect of gamma and microwave radiation on Aeromonas hydrophila inoculated in fish fillets. The study revealed that treatment of fish fillets with a dose of 1 kGy gamma radiation reduced the population of A.hydrophila by 104 cfu/g, while the dose of 2 and 3 kGy completely eliminated the microorganism. Treatment of fish fillets with microwave cooking for 1 and 2 minutes completely eliminated the microorganism. The physical examination of fish after gamma radiation treatment revealed that the used doses had no significant changes on fish fillets. The changes in protein profile (amino acids %) depended on radiation dose and period of cooking in microwave alongside controls while the total protein content was not affected.

  13. Short-duration exposure to 2.45 GHz microwave radiation induces ...

    African Journals Online (AJOL)

    ... disorganization in the testis of exposed group with increasing SARs. These results suggest that MW radiation has the potential to affect both male and female fertility adversely. Keywords: 2.45 GHz microwave radiation, histopathology, DNA single strand break, ovary, testis. African Journal of Biotechnology Vol. 12(2), pp.

  14. A Robust Algorithm to Determine the Topology of Space from the Cosmic Microwave Background Radiation

    OpenAIRE

    Weeks, Jeffrey R.

    2001-01-01

    Satellite measurements of the cosmic microwave back-ground radiation will soon provide an opportunity to test whether the universe is multiply connected. This paper presents a new algorithm for deducing the topology of the universe from the microwave background data. Unlike an older algorithm, the new algorithm gives the curvature of space and the radius of the last scattering surface as outputs, rather than requiring them as inputs. The new algorithm is also more tolerant of erro...

  15. Origin of the low frequency radiation emitted by radiative polaritons excited by infrared radiation in planar La2O3 films.

    Science.gov (United States)

    Vincent-Johnson, Anita J; Schwab, Yosyp; Mann, Harkirat S; Francoeur, Mathieu; Hammonds, James S; Scarel, Giovanna

    2013-01-23

    Upon excitation in thin oxide films by infrared radiation, radiative polaritons are formed with complex angular frequency ω, according to the theory of Kliewer and Fuchs (1966 Phys. Rev. 150 573). We show that radiative polaritons leak radiation with frequency ω(i) to the space surrounding the oxide film. The frequency ω(i) is the imaginary part of ω. The effects of the presence of the radiation leaked out at frequency ω(i) are observed experimentally and numerically in the infrared spectra of La(2)O(3) films on silicon upon excitation by infrared radiation of the 0TH type radiative polariton. The frequency ω(i) is found in the microwave to far infrared region, and depends on the oxide film chemistry and thickness. The presented results might aid in the interpretation of fine structures in infrared and, possibly, optical spectra, and suggest the study of other similar potential sources of electromagnetic radiation in different physical scenarios.

  16. Enhanced polarization of the cosmic microwave background radiation from thermal gravitational waves.

    Science.gov (United States)

    Bhattacharya, Kaushik; Mohanty, Subhendra; Nautiyal, Akhilesh

    2006-12-22

    If inflation was preceded by a radiation era, then at the time of inflation there will exist a decoupled thermal distribution of gravitons. Gravitational waves generated during inflation will be amplified by the process of stimulated emission into the existing thermal distribution of gravitons. Consequently, the usual zero temperature scale invariant tensor spectrum is modified by a temperature dependent factor. This thermal correction factor amplifies the B-mode polarization of the cosmic microwave background radiation by an order of magnitude at large angles, which may now be in the range of observability of the Wilkinson Microwave Anisotropy Probe.

  17. Influence of microwave frequency electromagnetic radiation on terpene emission and content in aromatic plants.

    Science.gov (United States)

    Soran, Maria-Loredana; Stan, Manuela; Niinemets, Ülo; Copolovici, Lucian

    2014-09-15

    Influence of environmental stress factors on both crop and wild plants of nutritional value is an important research topic. The past research has focused on rising temperatures, drought, soil salinity and toxicity, but the potential effects of increased environmental contamination by human-generated electromagnetic radiation on plants have little been studied. Here we studied the influence of microwave irradiation at bands corresponding to wireless router (WLAN) and mobile devices (GSM) on leaf anatomy, essential oil content and volatile emissions in Petroselinum crispum, Apium graveolens and Anethum graveolens. Microwave irradiation resulted in thinner cell walls, smaller chloroplasts and mitochondria, and enhanced emissions of volatile compounds, in particular, monoterpenes and green leaf volatiles (GLV). These effects were stronger for WLAN-frequency microwaves. Essential oil content was enhanced by GSM-frequency microwaves, but the effect of WLAN-frequency microwaves was inhibitory. There was a direct relationship between microwave-induced structural and chemical modifications of the three plant species studied. These data collectively demonstrate that human-generated microwave pollution can potentially constitute a stress to the plants. Copyright © 2014 Elsevier GmbH. All rights reserved.

  18. Influence of microwave frequency electromagnetic radiation on terpene emission and content in aromatic plants

    Science.gov (United States)

    Soran, Maria-Loredana; Stan, Manuela; Niinemets, Ülo; Copolovici, Lucian

    2015-01-01

    Influence of environmental stress factors on both crop and wild plants of nutritional value is an important research topic. The past research has focused on rising temperatures, drought, soil salinity and toxicity, but the potential effects of increased environmental contamination by human-generated electromagnetic radiation on plants have little been studied. Here we studied the influence of microwave irradiation at bands corresponding to wireless router (WLAN) and mobile devices (GSM) on leaf anatomy, essential oil content and volatile emissions in Petroselinum crispum, Apium graveolens and Anethum graveolens. Microwave irradiation resulted in thinner cell walls, smaller chloroplasts and mitochondria, and enhanced emissions of volatile compounds, in particular, monoterpenes and green leaf volatiles. These effects were stronger for WLAN-frequency microwaves. Essential oil content was enhanced by GSM-frequency microwaves, but the effect of WLAN-frequency microwaves was inhibitory. There was a direct relationship between microwave-induced structural and chemical modifications of the three plant species studied. These data collectively demonstrate that human-generated microwave pollution can potentially constitute a stress to the plants. PMID:25050479

  19. Behavioral teratologic studies using microwave radiation: is there an increased risk from exposure to cellular phones and microwave ovens?

    Science.gov (United States)

    Jensh, R P

    1997-01-01

    The objective of the investigations presented in this review was to determine if there are adverse effects due to chronic prenatal microwave exposure in rats at term and/or alterations in neonatal and adult offspring psychophysiologic development and growth. Following the establishment of a nonhyperthermal power density level of microwave radiation, pregnant rats were exposed throughout pregnancy to continuous wave 915 MHz, 2450 MHz, or 6000 MHz radiation at power density levels of 10, 20, or 35 mW/cm2, respectively. Teratologic evaluation included the following parameters: maternal weight and weight gain; mean litter size; maternal organ weight and organ weight/body weight ratios; body weight ratios of brain, liver, kidneys, and ovaries; maternal peripheral blood parameters including hematocrit, hemoglobin, and white cell counts; number of resorptions and resorption rate; number of abnormalities and abnormality rate; mean term fetal weight. Mothers were rebred, and the second, nonexposed litters were evaluated for teratogenic effects. Exposed offspring were evaluated using the following perinatal and adult tests: eye opening, surface righting, negative geotaxis, auditory startle, air righting, open field, activity wheel, swimming, and forelimb hanging. Offspring were also monitored for weekly weight and weight gain. Animals exposed to 915 MHz did not exhibit any consistent significant alterations in any of the above parameters. Exposure to 2450 MHz resulted only in a significantly increased adult offspring activity level compared to nonexposed offspring. Offspring exposed to 6000 MHz radiation exhibited an initial slight, but significant, retardation in term weight, while mothers had a significantly reduced monocyte count. No changes in any of the other term parameters were observed. A few postnatal parameters were affected in offspring exposed to 6000 MHz. Weekly weights were lower in the exposed offspring, but they recovered by the fifth week. Eye opening was

  20. Estimation of Radiofrequency Power Leakage from Microwave Ovens for Dosimetric Assessment at Nonionizing Radiation Exposure Levels

    Directory of Open Access Journals (Sweden)

    Peio Lopez-Iturri

    2015-01-01

    Full Text Available The electromagnetic field leakage levels of nonionizing radiation from a microwave oven have been estimated within a complex indoor scenario. By employing a hybrid simulation technique, based on coupling full wave simulation with an in-house developed deterministic 3D ray launching code, estimations of the observed electric field values can be obtained for the complete indoor scenario. The microwave oven can be modeled as a time- and frequency-dependent radiating source, in which leakage, basically from the microwave oven door, is propagated along the complete indoor scenario interacting with all of the elements present in it. This method can be of aid in order to assess the impact of such devices on expected exposure levels, allowing adequate minimization strategies such as optimal location to be applied.

  1. Effects of radiation emitted from visual display terminals on the oral health status

    International Nuclear Information System (INIS)

    Kazem, H.H.

    2008-01-01

    This study was designed to investigate the effects of exposure to radiation emitted from visual display terminals (VDTs) on the oral health status; a cross sectional study was carried out on 100 participants both males and females with age ranging between 22- 40 years working in various places in Cairo. They were divided into two groups; the first consists of 50 subjects working in front of VDTs eight hours min. daily, min. 5 days/ week, 2 years or more, and the other group 50 subjects working away from any VDTs. Both groups were subjected to both oral and dental examinations, including soft tissues assessment by using gingival index (GI) and hard tissues assessment by using decayed, missed, filled (DMF) index. Saliva analysis was done including ph analysis by ph meter cyberscan 500 and trace elements analysis by ion chromatography and salivary immunoglobulin A (sIgA) analysis by ELISA, body temperature by using digital thermometer. The values were compared between both groups and also between before and after exposure in the exposed group. The results demonstrated that the difference in the mean values of either GI or DMF or ph or anions and cations or sIgA levels between exposed and non exposed groups or even between before and after exposure in the exposed group was found to be statistically insignificant. On the other hand there were significant changes in the mean values of body temperature between exposed and non-exposed group and also between before and after exposure in the exposed group. Accordingly, within the limits of this study we can conclude that radiation emitted from VDTs affects body temperature, but do not have any effect on oral health including; hard or soft tissues or salivary components. This might be explained by the radiation with very low energy emitted from VDTs

  2. Effects of radiation emitted from visual display terminals on the oral health status

    Energy Technology Data Exchange (ETDEWEB)

    Kazem, H H [National Center for Radiation Research and Technology, Atomic Energy Authority, Cairo (Egypt)

    2008-07-01

    This study was designed to investigate the effects of exposure to radiation emitted from visual display terminals (VDTs) on the oral health status; a cross sectional study was carried out on 100 participants both males and females with age ranging between 22- 40 years working in various places in Cairo. They were divided into two groups; the first consists of 50 subjects working in front of VDTs eight hours min. daily, min. 5 days/ week, 2 years or more, and the other group 50 subjects working away from any VDTs. Both groups were subjected to both oral and dental examinations, including soft tissues assessment by using gingival index (GI) and hard tissues assessment by using decayed, missed, filled (DMF) index. Saliva analysis was done including ph analysis by ph meter cyberscan 500 and trace elements analysis by ion chromatography and salivary immunoglobulin A (sIgA) analysis by ELISA, body temperature by using digital thermometer. The values were compared between both groups and also between before and after exposure in the exposed group. The results demonstrated that the difference in the mean values of either GI or DMF or ph or anions and cations or sIgA levels between exposed and non exposed groups or even between before and after exposure in the exposed group was found to be statistically insignificant. On the other hand there were significant changes in the mean values of body temperature between exposed and non-exposed group and also between before and after exposure in the exposed group. Accordingly, within the limits of this study we can conclude that radiation emitted from VDTs affects body temperature, but do not have any effect on oral health including; hard or soft tissues or salivary components. This might be explained by the radiation with very low energy emitted from VDTs.

  3. Soil moisture estimation using reflected solar and emitted thermal infrared radiation

    Science.gov (United States)

    Jackson, R. D.; Cihlar, J.; Estes, J. E.; Heilman, J. L.; Kahle, A.; Kanemasu, E. T.; Millard, J.; Price, J. C.; Wiegand, C. L.

    1978-01-01

    Classical methods of measuring soil moisture such as gravimetric sampling and the use of neutron moisture probes are useful for cases where a point measurement is sufficient to approximate the water content of a small surrounding area. However, there is an increasing need for rapid and repetitive estimations of soil moisture over large areas. Remote sensing techniques potentially have the capability of meeting this need. The use of reflected-solar and emitted thermal-infrared radiation, measured remotely, to estimate soil moisture is examined.

  4. Skull and cerebrospinal fluid effects on microwave radiation propagation in human brain

    Science.gov (United States)

    Ansari, M. A.; Zarei, M.; Akhlaghipour, N.; Niknam, A. R.

    2017-12-01

    The determination of microwave absorption distribution in the human brain is necessary for the detection of brain tumors using thermo-acoustic imaging and for removing them using hyperthermia treatment. In contrast to ionizing radiation, hyperthermia treatment can be applied to remove tumors inside the brain without the concern of including secondary malignancies, which typically form from the neuronal cells of the septum pellucidum. The aim of this study is to determine the microwave absorption distribution in an adult human brain and to study the effects of skull and cerebrospinal fluid on the propagation of microwave radiation inside the brain. To this end, we simulate the microwave absorption distribution in a realistic adult brain model (Colin 27) using the mesh-based Monte Carlo (MMC) method. This is because in spite of there being other numerical methods, the MMC does not require a large memory, even for complicated geometries, and its algorithm is simple and easy to implement with low computational cost. The brain model is constructed using high-resolution (1 mm isotropic voxel) and low noise magnetic resonance imaging (MRI) scans and its volume contains 181×217×181 voxels, covering the brain completely. Using the MMC method, the radiative transport equation is solved and the absorbed microwave energy distribution in different brain regions is obtained without any fracture or anomaly. The simulation results show that the skull and cerebrospinal fluid guide the microwave radiation and suppress its penetration through deep brain compartments as a shielding factor. These results reveal that the MMC can be used to predict the amount of required energy to increase the temperature inside the tumour during hyperthermia treatment. Our results also show why a deep tumour inside an adult human brain cannot be efficiently treated using hyperthermia treatment. Finally, the accuracy of the presented numerical method is verified using the signal flow graph technique.

  5. Examination of the effects of ionising radiation on microwave transmission

    International Nuclear Information System (INIS)

    Excell, P.S.; Rousseau, M.

    1981-05-01

    It is proposed to use microwave heating to dry glass fibre 'slugs' soaked with an aqueous solution of fission product compounds. The method has been tested using two geometries (normal and oblique incidence) in equipment built at AERE Harwell. Tests have so far only been conducted with simulated fission product mixtures (the same chemicals using non-radioactive isotopes). A number of problems have already arisen which could affect the feasibility of microwave heating in this application and the possibility of further problems is envisaged when radioactive mixtures are used. The object of the investigation reported here was to assess the likely overall feasibility of the proposed process, in particular to assess the possibility that highly radioactive material may lower the threshold for electrical breakdown, and to suggest improvements that will mitigate potential problems. The layout of the proposed process is shown. (author)

  6. Optimised polarimeter configurations for measuring the Stokes parameters of the Cosmic Microwave Background Radiation

    OpenAIRE

    Couchot, F.; Delabrouille, J.; Kaplan, J.; Revenu, B.

    1998-01-01

    We present configurations of polarimeters which measure the three linear Stokes parameters of the Cosmic Microwave Background Radiation with a nearly diagonal error matrix, independent of the global orientation of the polarimeters in the focal plane. These configurations also provide the smallest possible error box volume.

  7. Operating a Microwave Radiation Detection Monitor. Module 10. Vocational Education Training in Environmental Health Sciences.

    Science.gov (United States)

    Consumer Dynamics Inc., Rockville, MD.

    This module, one of 25 on vocational education training for careers in environmental health occupations, contains self-instructional materials on operating a microwave radiation detection monitor. Following guidelines for students and instructors and an introduction that explains what the student will learn are three lessons: (1) testing the…

  8. Erratum: Correction to: Rapid and controllable perforation of carbon nanotubes by microwave radiation

    Science.gov (United States)

    Ojaghi, Neda; Mokhtarifar, Maryam; Sabaghian, Zahra; Arab, Hamed; Maghrebi, Morteza; Baniadam, Majid

    2018-06-01

    This study presents a new controlled approach to deep perforation of millimeter-long carbon nanotube arrays (CNTAs) by fast oxidative cutting. The approach is based on decorating CNTAs with silver (Ag) nanoparticles, followed by heating Ag-decorated CNTAs with microwave radiation (2.48 GHz, 300 W).

  9. Superposition of Planckian spectra and the distortions of the cosmic microwave background radiation

    International Nuclear Information System (INIS)

    Alexanian, M.

    1982-01-01

    A fit of the spectrum of the cosmic microwave background radiation (CMB) by means of a positive linear superposition of Planckian spectra implies an upper bound to the photon spectrum. The observed spectrum of the CMB gives a weighting function with a normalization greater than unity

  10. Responses of the mouse to microwave radiation during estrous cycle and pregnancy

    International Nuclear Information System (INIS)

    Rugh, R.; Ginns, E.I.; Ho, H.S.; Leach, W.M.

    1975-01-01

    A new facility for microwave irradiation of mice that will provide reproducible dosimetry is described. The waveguide used provided the integral dose rate to experimental animals under stable and controlled environmental conditions of relative humidity and temperature, variables which have been found to be critical in microwave studies. In terms of average absorbed lethal dose, the female mouse was found to be more sensitive to microwave irradiation during estrus than during diestrus. Teratogenesis (e.g., exencephalies) after sublethal irradiation of pregnant mice at 8 gestation days resulted from absorbed doses within the range of 3 to 5 calories per gram of body weight, and was never an all-or-none response. The incidence and variety of effects produced (hemorrhage, resorption, stunting, and fetal death) indicate that the cause and effect relationships are neither linear nor well enough established and understood to permit prediction of the biological effects either in the mouse of other species. As the absorbed dose of radiant energy is increased to the 8-day pregnant mouse, the probability of it producing at least one exencephaly is likewise increased. Nevertheless, the determination of the absorbed dose of microwave energy in each mouse is one step closer to determining the precise absorbed-dose-effect relationship for microwave exposures. A total of 1096 mice were exposed to microwave radiation and separately monitored to gather the related data. (U.S.)

  11. The apoptotic effect and the plausible mechanism of microwave radiation on rat myocardial cells.

    Science.gov (United States)

    Zhu, Wenhe; Cui, Yan; Feng, Xianmin; Li, Yan; Zhang, Wei; Xu, Junjie; Wang, Huiyan; Lv, Shijie

    2016-08-01

    Microwaves may exert adverse biological effects on the cardiovascular system at the integrated system and cellular levels. However, the mechanism underlying such effects remains poorly understood. Here, we report a previously uncharacterized mechanism through which microwaves damage myocardial cells. Rats were treated with 2450 MHz microwave radiation at 50, 100, 150, or 200 mW/cm(2) for 6 min. Microwave treatment significantly enhanced the levels of various enzymes in serum. In addition, it increased the malondialdehyde content while decreasing the levels of antioxidative stress enzymes, activities of enzyme complexes I-IV, and ATP in myocardial tissues. Notably, irradiated myocardial cells exhibited structural damage and underwent apoptosis. Furthermore, Western blot analysis revealed significant changes in expression levels of proteins involved in oxidative stress regulation and apoptotic signaling pathways, indicating that microwave irradiation could induce myocardial cell apoptosis by interfering with oxidative stress and cardiac energy metabolism. Our findings provide useful insights into the mechanism of microwave-induced damage to the cardiovascular system.

  12. Microwave radiation is effective at disinfecting dental stone surfaces without changing their physical properties.

    Science.gov (United States)

    Bona, Ariel José; Amaral-Brito, Mauro Gustavo; Rodrigues, José Augusto; Peruzzo, Daiane Cristina; França, Fabiana Mantovani Gomes

    2017-01-01

    The aims of this study were to evaluate the effectiveness of different microwave radiation regimens for disinfection of type IV dental stone surfaces and to assess the influence of these regimens on surface roughness and dimensional change following disinfection. Three hundred cylindrical (20 × 2-mm) test specimens were made in type IV stone and divided into subgroups of 20 according to the microorganisms tested (Staphylococcus aureus, Escherichia coli, or Candida albicans) and the 900-W microwave radiation protocol (cycles of 3, 5, or 7 minutes; a positive control; or a negative control). To test physical changes, 80 test specimens were made with the same dimensions except that they had 2 parallel and symmetrical indentations measuring 8 × 4 mm. These specimens were divided into 4 subgroups of 20 each (a subgroup for each radiation time and a negative control). The mean dimensional change and roughness data were analyzed by mixed models for repeated measures and Tukey-Kramer tests. Disinfection was analyzed with descriptive statistics. For E coli and C albicans, all radiation times proved effective at sterilizing the test specimens. For S aureus, sterilization was achieved with 5 and 7 minutes of exposure; however, colonies were observed in 10 Petri dishes (50%) exposed to 3 minutes of microwave radiation. No statistically significant difference in dimensional change or surface roughness was observed for any radiation regimen (P > 0.05).

  13. Fabrication and characterization of UV-emitting nanoparticles as novel radiation sensitizers targeting hypoxic tumor cells

    Science.gov (United States)

    Squillante, Michael R.; Jüstel, Thomas; Anderson, R. Rox; Brecher, Charles; Chartier, Daniel; Christian, James F.; Cicchetti, Nicholas; Espinoza, Sara; McAdams, Daniel R.; Müller, Matthias; Tornifoglio, Brooke; Wang, Yimin; Purschke, Martin

    2018-06-01

    Radiation therapy is one of the primary therapeutic techniques for treating cancer, administered to nearly two-thirds of all cancer patients. Although largely effective in killing cancer cells, radiation therapy, like other forms of cancer treatment, has difficulty dealing with hypoxic regions within solid tumors. The incomplete killing of cancer cells can lead to recurrence and relapse. The research presented here is investigating the enhancement of the efficacy of radiation therapy by using scintillating nanoparticles that emit UV photons. UV photons, with wavelengths between 230 nm and 280 nm, are able to inactivate cells due to their direct interaction with DNA, causing a variety of forms of damage. UV-emitting nanoparticles will enhance the treatment in two ways: first by generating UV photons in the immediate vicinity of cancer cells, leading to direct and oxygen-independent DNA damage, and second by down-converting the applied higher energy X-rays into softer X-rays and particles that are more efficiently absorbed in the targeted tumor region. The end result will be nanoparticles with a higher efficacy in the treatment of hypoxic cells in the tumor, filling an important, unmet clinical need. Our preliminary experiments show an increase in cell death using scintillating LuPO4:Pr nanoparticles over that achieved by the primary radiation alone. This work describes the fabrication of the nanoparticles, their physical characterization, and the spectroscopic characterization of the UV emission. The work also presents in vitro results that demonstrate an enhanced efficacy of cell killing with x-rays and a low unspecific toxicity of the nanoparticles.

  14. Dark energy and the cosmic microwave background radiation

    Science.gov (United States)

    Dodelson, S.; Knox, L.

    2000-01-01

    We find that current cosmic microwave background anisotropy data strongly constrain the mean spatial curvature of the Universe to be near zero, or, equivalently, the total energy density to be near critical-as predicted by inflation. This result is robust to editing of data sets, and variation of other cosmological parameters (totaling seven, including a cosmological constant). Other lines of argument indicate that the energy density of nonrelativistic matter is much less than critical. Together, these results are evidence, independent of supernovae data, for dark energy in the Universe.

  15. Propagation of Polarized Cosmic Microwave Background Radiation in an Anisotropic Magnetized Plasma

    International Nuclear Information System (INIS)

    Moskaliuk, S. S.

    2010-01-01

    The polarization plane of the cosmic microwave background radiation (CMBR) can be rotated either in a space-time with metric of anisotropic type and in a magnetized plasma or in the presence of a quintessential background with pseudoscalar coupling to electromagnetism. A unified treatment of these three phenomena is presented for cold anisotropic plasma at the pre-recombination epoch. It is argued that the generalized expressions derived in the present study may be relevant for direct searches of a possible rotation of the cosmic microwave background polarization.

  16. Effects of fetal microwave radiation exposure on offspring behavior in mice

    International Nuclear Information System (INIS)

    Zhang Yanchun; Li Zhihui; Gao Yan; Zhang Chenggang

    2015-01-01

    The recent rapid development of electronic communication techniques is resulting in a marked increase in exposure of humans to electromagnetic fields (EMFs). This has raised public concerns about the health hazards of long-term environmental EMF exposure for fetuses and children. Some studies have suggested EMF exposure in children could induce nervous system disorders. However, gender-dependent effects of microwave radiation exposure on cognitive dysfunction have not previously been reported. Here we investigated whether in utero exposure to 9.417-GHz microwave throughout gestation (Days 3.5–18) affected behavior, using the open field test (OFT), elevated-plus maze (EPM), tail suspension test (TST), forced swimming test (FST) and Morris water maze (MWM). We found that mice showed less movement in the center of an open field (using the OFT) and in an open arm (using the EPM) after in utero exposure to 9.417-GHz radiation, which suggested that the mice had increased anxiety-related behavior. Mice demonstrated reduced immobility in TST and FST after in utero exposure to 9.417-GHz radiation, which suggested that the mice had decreased depression-related behavior. From the MWM test, we observed that male offspring demonstrated decreased learning and memory, while females were not affected in learning and memory, which suggested that microwaves had gender-dependent effects. In summary, we have provided the first experimental evidence of microwaves inducing gender-dependent effects. (author)

  17. Interpretation of the cosmic microwave background radiation anisotropy detected by the COBE Differential Microwave Radiometer

    Science.gov (United States)

    Wright, E. L.; Meyer, S. S.; Bennett, C. L.; Boggess, N. W.; Cheng, E. S.; Hauser, M. G.; Kogut, A.; Lineweaver, C.; Mather, J. C.; Smoot, G. F.

    1992-01-01

    The large-scale cosmic background anisotropy detected by the COBE Differential Microwave Radiometer (DMR) instrument is compared to the sensitive previous measurements on various angular scales, and to the predictions of a wide variety of models of structure formation driven by gravitational instability. The observed anisotropy is consistent with all previously measured upper limits and with a number of dynamical models of structure formation. For example, the data agree with an unbiased cold dark matter (CDM) model with H0 = 50 km/s Mpc and Delta-M/M = 1 in a 16 Mpc radius sphere. Other models, such as CDM plus massive neutrinos (hot dark matter (HDM)), or CDM with a nonzero cosmological constant are also consistent with the COBE detection and can provide the extra power seen on 5-10,000 km/s scales.

  18. Cytogenetic monitoring of personnel occupationally exposed to microwave radiation of GEM radar

    International Nuclear Information System (INIS)

    Garaj-Vrhovac, Vera; Gajski, Goran; Brumen, Vlatka

    2008-01-01

    In the present study we analyzed and followed-up on the DNA damaging effects of microwave radiation of GEM radar equipment within microwave field of 10 μW/cm 2 to 10 mW/cm 2 in personnel occupationally exposed to frequency range of 1.5 GHz to 10.9 GHz. The single cell gel electrophoresis (SCGE)/comet assay as a tool for the bio monitoring of individuals accidentally, environmentally or occupationally exposed to physical or chemical agents was used to evaluate possible genotoxic effect on peripheral human blood lymphocytes. The comet assay is a method that allows efficient determination of single strand breaks (SSB) and double-strand breaks (DSB), as well as alkali-labile sites in the DNA of single cells. The comet assay was carried out under alkaline conditions. We measured the baseline comet assay effect in whole blood samples. Parameter of the comet assay was studied in workers occupationally exposed to microwave radiation of GEM radar and in corresponding unexposed control subjects. It was found that in the subjects who were occupationally exposed to microwave radiation, the levels of DNA damage increased compare to control group and showed interindividual variations. As a measure of DNA damage tail length was used, calculated from the centre of the head and presented in micrometers (μm). Mean value of exposed group was 13.54±1.44 as opposed to control mean value that was 13.15±1.39. Differences between mean tail lengths were statistically significant (P<0.05, ANOVA). The results of this study indicate that individuals occupationally exposed to microwave frequency of GEM radar equipment may experience an increased genotoxic risk, emphasizing the importance of individual bio monitoring, limiting exposure and radiation safety programs. (author)

  19. Microwave-Assisted Synthesis of Red-Light Emitting Au Nanoclusters with the Use of Egg White

    Science.gov (United States)

    Tian, Jinghan; Yan, Lei; Sang, Aohua; Yuan, Hongyan; Zheng, Baozhan; Xiao, Dan

    2014-01-01

    We developed a simple, cost-effective, and eco-friendly method to synthesize gold nanoclusters (AuNCs) with red fluorescence. The experiment was performed using HAuCl[subscript 4], egg white, Na[subscript 2]CO[subscript 3] (known as soda ash or washing soda), and a microwave oven. In our experiment, fluorescent AuNCs were prepared within a…

  20. Selected properties of the potato snacks expanded in the microwave radiation

    Directory of Open Access Journals (Sweden)

    Mitrus Marcin

    2018-01-01

    Full Text Available The results of measurements of the selected properties of the extruded potato pellets and snacks expanded in the microwave field are presented in the paper. The potato pellets with the addition of the baking soda were prepared with a single screw extruder TS-45. The snacks were obtained by pellets expansion in a conventional microwave oven. The expansion index and the hardness of the pellets and the snacks, as well as, the texture properties of the snacks were evaluated during this study. The results showed that baking soda addition reduced the potato pellet expansion during their extrusion. This was an effect of a smaller thickness of the obtained pellets. The addition of baking soda had positive influence on potato snacks expansion in microwave radiation. The higher content of the soda additive resulted in lower hardness of pellets during cutting tests. The opposite effect was observed during texture measurements of the snacks. The addition of baking soda increased hardness of the expanded snacks. Soda addition lowers crispness and fragilityof the potato snacks expanded in the microwave radiation.

  1. Detection of On-Chip Generated Weak Microwave Radiation Using Superconducting Normal-Metal SET

    Directory of Open Access Journals (Sweden)

    Behdad Jalali-Jafari

    2016-01-01

    Full Text Available The present work addresses quantum interaction phenomena of microwave radiation with a single-electron tunneling system. For this study, an integrated circuit is implemented, combining on the same chip a Josephson junction (Al/AlO x /Al oscillator and a single-electron transistor (SET with the superconducting island (Al and normal-conducting leads (AuPd. The transistor is demonstrated to operate as a very sensitive photon detector, sensing down to a few tens of photons per second in the microwave frequency range around f ∼ 100 GHz. On the other hand, the Josephson oscillator, realized as a two-junction SQUID and coupled to the detector via a coplanar transmission line (Al, is shown to provide a tunable source of microwave radiation: controllable variations in power or in frequency were accompanied by significant changes in the detector output, when applying magnetic flux or adjusting the voltage across the SQUID, respectively. It was also shown that the effect of substrate-mediated phonons, generated by our microwave source, on the detector output was negligibly small.

  2. Volatiles emitted from flowers by gamma-radiated and nonradiated Jasminum polyanthum Franch. in situ

    International Nuclear Information System (INIS)

    Christensen, L.P.; Jakobsen, H.B.; Kristiansen, K.; Moller, J.

    1997-01-01

    Volatile compounds emitted from flowers of Jasminum polyanthum Pepita in situ were collected by dynamic headspace technique and analyzed by GC-FID and GC-MS. A total of 32 compounds were identified. The flower scent was dominated by benzyl acetate (57.8%), p-cresol (12.2%), (E)-isoeugenol (9.7%), eugenol (3.5%), 2-methoxy-p-cresol (3.1%), linalool (3.0%), phenethyl acetate (2.1%), and (Z)3-hexenyl butyrate (1.9%). The strong scent of Pepita reduces its production potentialities as a pot plant, thus the possibility to reduce or modify the emission of volatiles from Pepita by mutagenesis was investigated. The average total yields of volatiles in Pepita were approximately 2800 ng flower-1 h-1, and in one gamma-radiated clone a significantly lower yield of 1050 ng flower-1 h-1 was found. The volatile profiles of the gamma-radiated plants were made up of the same 32 compounds found in Pepita. Significant differences in the headspace composition between Pepita and gamma-radiated plants were found for some of the major volatiles

  3. Relative risk analysis in regulating the use of radiation-emitting medical devices. A preliminary application

    Energy Technology Data Exchange (ETDEWEB)

    Jones, E.D.; Banks, W.W.; Altenbach, T.J.; Fischer, L.E. [Lawrence Livermore National Lab., CA (United States)

    1995-09-01

    This report describes a preliminary application of an analysis approach for assessing relative risks in the use of radiation- emitting medical devices. Results are presented on human-initiated actions and failure modes that are most likely to occur in the use of the Gamma Knife, a gamma irradiation therapy device. This effort represents an initial step in a US Nuclear Regulatory Commission (NRC) plan to evaluate the potential role of risk analysis in regulating the use of nuclear medical devices. For this preliminary application of risk assessment, the focus was to develop a basic process using existing techniques for identifying the most likely risk contributors and their relative importance. The approach taken developed relative risk rankings and profiles that incorporated the type and quality of data available and could present results in an easily understood form. This work was performed by the Lawrence Livermore National Laboratory for the NRC.

  4. Relative risk analysis in regulating the use of radiation-emitting medical devices. A preliminary application

    International Nuclear Information System (INIS)

    Jones, E.D.; Banks, W.W.; Altenbach, T.J.; Fischer, L.E.

    1995-09-01

    This report describes a preliminary application of an analysis approach for assessing relative risks in the use of radiation- emitting medical devices. Results are presented on human-initiated actions and failure modes that are most likely to occur in the use of the Gamma Knife, a gamma irradiation therapy device. This effort represents an initial step in a US Nuclear Regulatory Commission (NRC) plan to evaluate the potential role of risk analysis in regulating the use of nuclear medical devices. For this preliminary application of risk assessment, the focus was to develop a basic process using existing techniques for identifying the most likely risk contributors and their relative importance. The approach taken developed relative risk rankings and profiles that incorporated the type and quality of data available and could present results in an easily understood form. This work was performed by the Lawrence Livermore National Laboratory for the NRC

  5. Resonance effects of transition radiation emitted from thin foil stacks using electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Awata, Takaaki; Yajima, Kazuaki; Tanaka, Takashi [Kyoto Univ. (Japan). Faculty of Engineering; and others

    1997-03-01

    Transition Radiation(TR) X rays are expected to be a high brilliant X-ray source because the interference among TR X rays emitted from many thin foils placed periodically in vacuum can increase their intensity and make them quasi-monochromatic. In order to study the interference (resonance) effects of TR, we measured the energy spectra of TR for several sets of thin-foil stacks at various emission angles. It was found that the resonance effects of TR are classified into intrafoil and interfoil resonances and the intensity of TR X rays increases nonlinearly with increasing foil number, attributing to the interfoil resonance. It became evident that the brilliance of TR is as high as that of SR. (author)

  6. Exploring the Large Scale Anisotropy in the Cosmic Microwave Background Radiation at 170 GHz

    Science.gov (United States)

    Ganga, Kenneth Matthew

    1994-01-01

    In this thesis, data from the Far Infra-Red Survey (FIRS), a balloon-borne experiment designed to measure the large scale anisotropy in the cosmic microwave background radiation, are analyzed. The FIRS operates in four frequency bands at 170, 280, 480, and 670 GHz, using an approximately Gaussian beam with a 3.8 deg full-width-at-half-maximum. A cross-correlation with the COBE/DMR first-year maps yields significant results, confirming the DMR detection of anisotropy in the cosmic microwave background radiation. Analysis of the FIRS data alone sets bounds on the amplitude of anisotropy under the assumption that the fluctuations are described by a Harrison-Peebles-Zel'dovich spectrum and further analysis sets limits on the index of the primordial density fluctuations for an Einstein-DeSitter universe. Galactic dust emission is discussed and limits are set on the magnitude of possible systematic errors in the measurement.

  7. Investigation of the Surface Filamentary Discharge in Focus of Microwave Radiation

    Science.gov (United States)

    2010-08-01

    microwave radiation 5a. CONTRACT NUMBER ISTC Registration No: 3784 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Dr. Kirill...NUMBER(S) ISTC 07-7011 12. DISTRIBUTION/AVAILABILITY STATEMENT Approved for public release; distribution is unlimited. (approval given by local...contract to the International Science and Technology Center ( ISTC ), Moscow Project ISTC # 3784p (077011) Investigation of the surface filamentary

  8. Dielectric and Radiative Properties of Sea Foam at Microwave Frequencies: Conceptual Understanding of Foam Emissivity

    OpenAIRE

    Peter W. Gaiser; Magdalena D. Anguelova

    2012-01-01

    Foam fraction can be retrieved from space-based microwave radiometric data at frequencies from 1 to 37 GHz. The retrievals require modeling of ocean surface emissivity fully covered with sea foam. To model foam emissivity well, knowledge of foam properties, both mechanical and dielectric, is necessary because these control the radiative processes in foam. We present a physical description of foam dielectric properties obtained from the foam dielectric constant including foam skin depth; foam ...

  9. Microwave radiation, in the absence of hyperthermia, has no detectable effect on synapsin I levels or phosphorylation

    International Nuclear Information System (INIS)

    Browning, M.D.; Haycock, J.W.

    1988-01-01

    Recent reports have indicated that microwave radiation can produce effects on a variety of cell types in vitro. To determine whether microwave radiation might be neurotoxic, the effects of microwave radiation on synapsin I have been examined. Synapsin I is a neuron-specific phosphoprotein that is present in all neurons, where it is localized to the presynaptic terminal and is associated with synaptic vesicles. O'Callaghan and Miller have demonstrated that studies of such neuron-specific proteins can provide reliable indices of neurotoxicity. We have used a radioimmunoassay for synapsin I to determine whether microwave irradiation has any effect on the levels of synapsin I. Neither acute nor chronic exposure to microwave irradiation had any detectable effect on synapsin I levels. We have also examined the calcium-dependent phosphorylation of synapsin I in synaptosomes isolated from rats that had been subjected to microwave radiation. The phosphorylation of synapsin I in synaptosomes reflects numerous components of the presynaptic aspect of neuronal transmission. At intensities below that required to produce mild hyperthermia, no effects of microwave irradiation were seen on synapsin I phosphorylation

  10. Microwave radiation (2.45 GHz)-induced oxidative stress: Whole-body exposure effect on histopathology of Wistar rats.

    Science.gov (United States)

    Chauhan, Parul; Verma, H N; Sisodia, Rashmi; Kesari, Kavindra Kumar

    2017-01-01

    Man-made microwave and radiofrequency (RF) radiation technologies have been steadily increasing with the growing demand of electronic appliances such as microwave oven and cell phones. These appliances affect biological systems by increasing free radicals, thus leading to oxidative damage. The aim of this study was to explore the effect of 2.45 GHz microwave radiation on histology and the level of lipid peroxide (LPO) in Wistar rats. Sixty-day-old male Wistar rats with 180 ± 10 g body weight were used for this study. Animals were divided into two groups: sham exposed (control) and microwave exposed. These animals were exposed for 2 h a day for 35 d to 2.45 GHz microwave radiation (power density, 0.2 mW/cm 2 ). The whole-body specific absorption rate (SAR) was estimated to be 0.14 W/kg. After completion of the exposure period, rats were sacrificed, and brain, liver, kidney, testis and spleen were stored/preserved for determination of LPO and histological parameters. Significantly high level of LPO was observed in the liver (p body microwave exposure, compared to the control group. Based on the results obtained in this study, we conclude that exposure to microwave radiation 2 h a day for 35 d can potentially cause histopathology and oxidative changes in Wistar rats. These results indicate possible implications of such exposure on human health.

  11. Exposure of cultured astroglial and microglial brain cells to 900 MHz microwave radiation.

    Science.gov (United States)

    Thorlin, Thorleif; Rouquette, Jean-Michel; Hamnerius, Yngve; Hansson, Elisabeth; Persson, Mikael; Björklund, Ulrika; Rosengren, Lars; Rönnbäck, Lars; Persson, Mikael

    2006-08-01

    The rapid rise in the use of mobile communications has raised concerns about health issues related to low-level microwave radiation. The head and brain are usually the most exposed targets in mobile phone users. In the brain, two types of glial cells, the astroglial and the microglial cells, are interesting in the context of biological effects from microwave exposure. These cells are widely distributed in the brain and are directly involved in the response to brain damage as well as in the development of brain cancer. The aim of the present study was to investigate whether 900 MHz radiation could affect these two different glial cell types in culture by studying markers for damage-related processes in the cells. Primary cultures enriched in astroglial cells were exposed to 900 MHz microwave radiation in a temperature-controlled exposure system at specific absorption rates (SARs) of 3 W/kg GSM modulated wave (mw) for 4, 8 and 24 h or 27 W/kg continuous wave (cw) for 24 h, and the release into the extracellular medium of the two pro-inflammatory cytokines interleukin 6 (Il6) and tumor necrosis factor-alpha (Tnfa) was analyzed. In addition, levels of the astroglial cell-specific reactive marker glial fibrillary acidic protein (Gfap), whose expression dynamics is different from that of cytokines, were measured in astroglial cultures and in astroglial cell-conditioned cell culture medium at SARs of 27 and 54 W/kg (cw) for 4 or 24 h. No significant differences could be detected for any of the parameters studied at any time and for any of the radiation characteristics. Total protein levels remained constant during the experiments. Microglial cell cultures were exposed to 900 MHz radiation at an SAR of 3 W/kg (mw) for 8 h, and I16, Tnfa, total protein and the microglial reactivity marker ED-1 (a macrophage activation antigen) were measured. No significant differences were found. The morphology of the cultured astroglial cells and microglia was studied and appeared to be

  12. Male reproductive health under threat: Short term exposure to radiofrequency radiations emitted by common mobile jammers

    Directory of Open Access Journals (Sweden)

    SMJ Mortazavi

    2013-01-01

    Full Text Available Background: Modern life prompted man to increasingly generate, transmit and use electricity that leads to exposure to different levels of electromagnetic fields (EMFs. Substantial evidence indicates that exposure to common sources of EMF such as mobile phones, laptops or wireless internet-connected laptops decreases human semen quality. In some countries, mobile jammers are occasionally used in offices, shrines, conference rooms and cinemas to block the signal. Aims: To the best of our knowledge, this is the first study to investigate the effect of short term exposure of human sperm samples to radiofrequency (RF radiations emitted by common mobile jammers. Subjects and Methods: Fresh semen samples were collected by masturbation from 30 healthy donors who had referred to Infertility Treatment Center at the Mother and Child Hospital with their wives. Female problem was diagnosed as the reason for infertility in these couples. Statistical Analysis: T-test and analysis of variance were used to show statistical significance. Results: The motility of sperm samples exposed to jammer RF radiation for 2 or 4 h were significantly lower than those of sham-exposed samples. These findings lead us to the conclusion that mobile jammers may significantly decrease sperm motility and the couples′ chances of conception. Conclusion: Based on these results, it can be suggested that in countries that have not banned mobile jammer use, legislations should be urgently passed to restrict the use of these signal blocking devices in public or private places.

  13. Male reproductive health under threat: Short term exposure to radiofrequency radiations emitted by common mobile jammers

    Science.gov (United States)

    Mortazavi, SMJ; Parsanezhad, ME; Kazempour, M; Ghahramani, P; Mortazavi, AR; Davari, M

    2013-01-01

    BACKGROUND: Modern life prompted man to increasingly generate, transmit and use electricity that leads to exposure to different levels of electromagnetic fields (EMFs). Substantial evidence indicates that exposure to common sources of EMF such as mobile phones, laptops or wireless internet-connected laptops decreases human semen quality. In some countries, mobile jammers are occasionally used in offices, shrines, conference rooms and cinemas to block the signal. AIMS: To the best of our knowledge, this is the first study to investigate the effect of short term exposure of human sperm samples to radiofrequency (RF) radiations emitted by common mobile jammers. SUBJECTS AND METHODS: Fresh semen samples were collected by masturbation from 30 healthy donors who had referred to Infertility Treatment Center at the Mother and Child Hospital with their wives. Female problem was diagnosed as the reason for infertility in these couples. STATISTICAL ANALYSIS: T-test and analysis of variance were used to show statistical significance. RESULTS: The motility of sperm samples exposed to jammer RF radiation for 2 or 4 h were significantly lower than those of sham-exposed samples. These findings lead us to the conclusion that mobile jammers may significantly decrease sperm motility and the couples’ chances of conception. CONCLUSION: Based on these results, it can be suggested that in countries that have not banned mobile jammer use, legislations should be urgently passed to restrict the use of these signal blocking devices in public or private places. PMID:24082653

  14. On the radiation emitted by a particle falling into a black hole in the semi-relativistic approximation

    International Nuclear Information System (INIS)

    Coretti, C.; Ferrari, V.

    1986-01-01

    In this paper the limits of applicability of the semi-relativistic approximation for estimating the radiation emitted in processes of capture of particles by black holes are discussed. It is shown that it gives reliable estimates in the case of spherically symmetric black holes, but it fails in the case of rotating black holes

  15. A Study of the interaction of radiation and semiconductor lasers: an analysis of transient and permanent effects induced on edge emitting and vertical cavity surface emitting laser diodes

    International Nuclear Information System (INIS)

    Pailharey, Eric

    2000-01-01

    The behavior of laser diodes under transient environment is presented in this work. The first section describes the basic phenomena of radiation interaction with matter. The radiative environments, the main characteristics of laser diodes and the research undertaken on the subject are presented and discussed. The tests on 1300 nm edge emitting laser diode are presented in the second section. The response to a transient ionizing excitation is explored using a 532 nm laser beam. The time of return to steady state after the perturbation is decomposed into several steps: decrease of the optical power during excitation, turn-on delay, relaxation oscillations and optical power offset. Their origins are analyzed using the device structure. To include all the phenomena in a numerical simulation of the device, an individual study of low conductivity materials used for the lateral confinement of the current density is undertaken. The effects of a single particle traversing the optical cavity and an analysis of permanent damages induced by neutrons are also determined. In the last section, 850 nm vertical cavity surface emitting laser diodes (VCSEL) are studied. The behavior of these devices which performances are in constant evolution, is investigated as a function of both temperature and polarization. Then VCSEL are submitted to transient ionizing irradiation and their responses are compared to those of edge emitting diodes. When proton implantation is used in the process, we observe the same behavior for both technologies. VCSEL were submitted to neutron fluence and we have studied the influence of the damages on threshold current, emission patterns and maximum of optical power. (author) [fr

  16. Modification in oxidative processes in muscle tissues exposed to laser- and light-emitting diode radiation.

    Science.gov (United States)

    Monich, Victor A; Bavrina, Anna P; Malinovskaya, Svetlana L

    2018-01-01

    Exposure of living tissues to high-intensity red or near-infrared light can produce the oxidative stress effects both in the target zone and adjacent ones. The protein oxidative modification (POM) products can be used as reliable and early markers of oxidative stress. The contents of modified proteins in the investigated specimens can be evaluated by the 2,4-dinitrophenylhydrazine assay (the DNPH assay). Low-intensity red light is able to decrease the activity of oxidative processes and the DNPH assay data about the POM products in the biological tissues could show both an oxidative stress level and an efficiency of physical agent protection against the oxidative processes. Two control groups of white rats were irradiated by laser light, the first control group by red light and the second one by near-infrared radiation (NIR).Two experimental groups were consequently treated with laser and red low-level light-emitting diode radiation (LED). One of them was exposed to red laser light + LED and the other to NIR + LED. The fifth group was intact. Each group included ten animals. The effect of laser light was studied by methods of protein oxidative modifications. We measured levels of both induced and spontaneous POM products by the DNPH assay. The dramatic increase in levels of POM products in the control group samples when compared with the intact group data as well as the sharp decrease in the POM products in the experimental groups treated with LED low-level light were statistically significant (p ≤ 0.05). Exposure of skeletal muscles to high-intensity red and near-infrared laser light causes oxidative stress that continues not less than 3 days. The method of measurement of POM product contents by the DNPH assay is a reliable test of an oxidative process rate. Red low-intensity LED radiation can provide rehabilitation of skeletal muscle tissues treated with high-intensity laser light.

  17. Composite materials for protection against electromagnetic microwave radiation

    International Nuclear Information System (INIS)

    Senyk, IV; Barsukov, VZ; Savchenko, BM; Shevchenko, KL; Plavan, VP; Shpak, Yu V; Kruykova, OA

    2016-01-01

    A fairly wide range of carbon-polymer composite materials was synthesized and studied in terms of their potential to protect people and electronic equipment from exposure to electromagnetic radiation (EMR). The materials studied included three main groups: (1) PVC polymer composites filled with various carbon-containing fillers (colloidal graphite, thermally expanded graphite, acetylene black, graphitized carbon black, carbon nanotubes, graphene) at concentrations ranging from 5 to 20%; (2) carbon cloth - commercial and modified with nanometal additives (e.g., nanoparticles of Cu, TiN, etc.); (3) highly-filled polymer-carbon composites in the form of paint. The transmission rate a of electromagnetic radiation was investigated for such materials in the frequency range of 10 GHz as well as their electrical conductivity. The results showed that the shielding ability of the materials of group (2) is significantly higher than that of the materials of group (1), which is probably due to the presence of strong internal skeleton of conductivity. Nevertheless, some highly-filled mixed polymer-carbon composites in the form of paint demonstrate even more shielding ability than carbon cloth and could be used for the defense against EMR. (paper)

  18. Analysis of the electromagnetic radiation generated by a multipactor discharge occurring within a microwave passive component

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, M; Quesada, F; Alvarez, A [Department of Information and Communication Technologies, Technical University of Cartagena, Cartagena (Murcia) (Spain); Gimeno, B [Departamento de Fisica Aplicada y Electromagnetismo-ICMUV, Universidad de Valencia, Valencia (Spain); Miquel-Espanya, C; Raboso, D [European Space Agency (ESA), European Space Research and Technology Center (ESTEC), Noordwijk (Netherlands); Anza, S; Vicente, C; Gil, J [Aurora Software and Testing S.L., Valencia, Valencia (Spain); Taroncher, M; Reglero, M; Boria, V E, E-mail: benito.gimeno@uv.e [Departamento de Comunicaciones-ITEAM, Universidad Politecnica de Valencia (Spain)

    2010-10-06

    Multipactoring is a non-linear phenomenon that appears in high-power microwave equipment operating under vacuum conditions and causes several undesirable effects. In this paper, a theoretical and experimental study of the RF spectrum radiated by a multipactor discharge, occurring within a realistic microwave component based on rectangular waveguides, is reported. The electromagnetic coupling of a multipactor current to the fundamental propagative mode of a uniform waveguide has been analysed in the context of the microwave network theory. The discharge produced under a single-carrier RF voltage regime has been approached as a shunt current source exciting such a mode in a transmission-line gap region. By means of a simple equivalent circuit, this model allows prediction of the harmonics generated by the discharge occurring in a realistic passive waveguide component. Power spectrum radiated by a third-order multipactor discharge has been measured in an E-plane silver-plated waveguide transformer, thus validating qualitatively the presented theory to simulate the noise generated by a single-carrier multipactor discharge.

  19. The study of thermal interaction and microstructure of sodium silicate/bentonite composite under microwave radiation

    Energy Technology Data Exchange (ETDEWEB)

    Subannajui, Kittitat, E-mail: kittitat.sub@mahidol.ac.th [Faculty of Science, Mahidol University, 272 Rama VI Road, Ratchathewi District, Bangkok 10400 (Thailand); Center of Nanoscience and Nanotechnology Research Unit, Mahidol University, 272 Rama VI Road, Ratchathewi District, Bangkok 10400 (Thailand)

    2016-12-01

    The commercial heating oven usually consumes the power around 2500–3000 Watt and the temperature inside the oven is still below 350 °C. If we need to increase a temperature above 500 °C, a special heating setup with a higher power furnace is required. However, in this work, we propose a composite material that interacts with 2.45 GHz 500 Watt microwave and rapidly redeems the thermal energy with the temperature around 600–900 °C. The composite amorphous material easily forms liquid ceramics phase with a high temperature output and responds to the microwave radiation better than that of the solid phase. During the heating process, phase transformation occurs. This method is very effective and can be used to drastically reduce the power consumption of any heating process. - Highlights: • Amorphous phase transforms to liquid phase by microwave radiation. • Pure sodium silicate and pure bentonite cannot show temperature overshoot. • Silicate-bentonite composite shows a high temperature overshoot above 700 °C. • A rapid heating crucible for the annealing application is fabricated.

  20. The Cosmic Microwave Background Radiation-A Unique Window on the Early Universe

    Science.gov (United States)

    Hinshaw, Gary

    2010-01-01

    The cosmic microwave background radiation is the remnant heat from the Big Bang. It provides us with a unique probe of conditions in the early universe, long before any organized structures had yet formed. The anisotropy in the radiation's brightness yields important clues about primordial structure and additionally provides a wealth of information about the physics of the early universe. Within the framework of inflationary dark matter models, observations of the anisotropy on sub-degree angular scales reveals the signatures of acoustic oscillations of the photon-baryon fluid at a redshift of 11 00. Data from the first seven years of operation of the Wilkinson Microwave Anisotropy Probe (WMAP) satellite provide detailed full-sky maps of the cosmic microwave background temperature and polarization anisotropy. Together, the data provide a wealth of cosmological information, including the age of the universe, the epoch when the first stars formed, and the overall composition of baryonic matter, dark matter, and dark energy. The results also provide constraints on the period of inflationary expansion in the very first moments of time. WMAP, part of NASA's Explorers program, was launched on June 30, 2001. The WMAP satellite was produced in a partnership between the Goddard Space Flight Center and Princeton University. The WMAP team also includes researchers at the Johns Hopkins University; the Canadian Institute of Theoretical Astrophysics; University of Texas; Oxford University; University of Chicago; Brown University; University of British Columbia; and University of California, Los Angeles.

  1. Microwave discharge electrodeless lamps (MDEL). V. Microwave-assisted photolytic disinfection of Bacillus subtilis in simulated electroplating wash wastewaters.

    Science.gov (United States)

    Horikoshi, Satoshi; Tsuchida, Akihiro; Abe, Masahiko; Ohba, Naoki; Uchida, Masayoshi; Serpone, Nick

    2010-01-01

    This short article examines the microwave-assisted photolytic disinfection of aqueous solutions contaminated by Bacillus subtilis microorganisms using UV and vacuum-UV radiation emitted from a microwave discharge electrodeless lamp (MDEL), a device containing a Hg/Ar gas-fill that was proposed recently for use in Advanced Oxidation Processes (AOPs). Results of the disinfection are compared with those obtained from UV radiation emitted by a low-pressure electrode Hg lamp and by an excimer lamp. Also examined is the disinfection of B. subtilis aqueous media that contained Au3+ or Ni2+ ions, species often found in the treatment of electroplating wash wastewaters.

  2. A New Microwave Shield Preparation for Super High Frequency Range: Occupational Approach to Radiation Protection.

    Science.gov (United States)

    Zaroushani, Vida; Khavanin, Ali; Jonidi Jafari, Ahmad; Mortazavi, Seyed Bagher

    2016-01-01

    Widespread use of X-band frequency (a part of the super high frequency microwave) in the various workplaces would contribute to occupational exposure with potential of adverse health effects.  According to limited study on microwave shielding for the workplace, this study tried to prepare a new microwave shielding for this purpose. We used EI-403 epoxy thermosetting resin as a matrix and nickel oxide nanoparticle with the diameter of 15-35 nm as filler. The Epoxy/ Nickel oxide composites with 5, 7, 9 and 11 wt% were made in three different thicknesses (2, 4 and 6 mm). According to transmission / reflection method, shielding effectiveness (SE) in the X-band frequency range (8-12.5 GHz) was measured by scattering parameters directly given by the 2-port Vector Network Analyzer. The fabricated composites characterized by X-ray Diffraction and Field Emission Scanning Electron Microscope. The best average of shielding effectiveness in each thickness of fabricated composites obtained by 11%-2 mm, 7%-4 mm and 7%-6 mm composites with SE values of 46.80%, 66.72% and 64.52%, respectively. In addition, the 11%-6 mm, 5%-6 mm and 11%-4 mm-fabricated composites were able to attenuate extremely the incident microwave energy at 8.01, 8.51 and 8.53 GHz by SE of 84.14%, 83.57 and 81.30%, respectively. The 7%-4mm composite could be introduced as a suitable alternative microwave shield in radiation protection topics in order to its proper SE and other preferable properties such as low cost and weight, resistance to corrosion etc. It is necessary to develop and investigate the efficacy of the fabricated composites in the fields by future studies.

  3. The Effect of Gamma radiation, microwave radiation, their interaction and storage on chemical composition, antinutritional factors and the activities of trypsin inhibitor and lipoxygenase of soybean seeds

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Rahim, E A; Abdel-Fatah, O M [Dept. of Biochem., Faculty of Agric., Cairo University. (Egypt); El-Adawy, M; Badea, M Y [Food Technol. Dept., National Center for Research and Radiation Technol., Atomic Energy Authority (Egypt)

    2000-07-01

    The effect of gamma radiation, microwave radiation, interaction between them; and storage of radiated soybean seeds were investigated to find out the best treatment which had to the maximum reduction of antinutrional factors (Trypsin inhibitor and lipoxygenase activities) without significant effect on the chemical constituents. The gamma rays was used at three doses of 2.5, 5.0 and 8.0 kGy, microwave radiation was at 70 level power for 2 and 4 min; and the storage of seeds was at temperature, R.H. 50-55% for six months. The data revealed that, effects of interaction treatments were more effective than the treatment with microwave or gamma radiation alone.

  4. The Effect of Gamma radiation, microwave radiation, their interaction and storage on chemical composition, antinutritional factors and the activities of trypsin inhibitor and lipoxygenase of soybean seeds

    International Nuclear Information System (INIS)

    Abdel-Rahim, E.A.; Abdel-Fatah, O.M.; El-Adawy, M.; Badea, M.Y.

    2000-01-01

    The effect of gamma radiation, microwave radiation, interaction between them; and storage of radiated soybean seeds were investigated to find out the best treatment which had to the maximum reduction of antinutrional factors (Trypsin inhibitor and lipoxygenase activities) without significant effect on the chemical constituents. The gamma rays was used at three doses of 2.5, 5.0 and 8.0 kGy, microwave radiation was at 70 level power for 2 and 4 min; and the storage of seeds was at temperature, R.H. 50-55% for six months. The data revealed that, effects of interaction treatments were more effective than the treatment with microwave or gamma radiation alone

  5. Infrared light-emitting diode radiation causes gravitropic and morphological effects in dark-grown oat seedlings

    Science.gov (United States)

    Johnson, C. F.; Brown, C. S.; Wheeler, R. M.; Sager, J. C.; Chapman, D. K.; Deitzer, G. F.

    1996-01-01

    Oat (Avena sativa cv Seger) seedlings were irradiated with IR light-emitting diode (LED) radiation passed through a visible-light-blocking filter. Infrared LED irradiated seedlings exhibited differences in growth and gravitropic response when compared to seedlings grown in darkness at the same temperature. Thus, the oat seedlings in this study were able to detect IR LED radiation. These findings call into question the use of IR LED as a safe-light for some photosensitive plant response experiments. These findings also expand the defined range of wavelengths involved in radiation-gravity (light-gravity) interactions to include wavelengths in the IR region of the spectrum.

  6. Microwave-radiation-induced molecular structural rearrangement of hen egg-white lysozyme

    Science.gov (United States)

    Singh, Anang K.; Burada, P. S.; Bhattacharya, Susmita; Bag, Sudipta; Bhattacharya, Amitabha; Dasgupta, Swagata; Roy, Anushree

    2018-05-01

    We have investigated the nonthermal effect of 10 GHz/22 dBm microwave radiation on hen egg-white lysozyme (HEWL) over different irradiation times, ranging from 2 min to 1 h. To ensure a control over the radiation parameters, a pair of microwave rectangular waveguides is used to irradiate the samples. Optical spectroscopic measurements, which include UV-visible absorption spectroscopy, Raman spectroscopy, and far UV CD spectroscopy, reveal the exposure of the buried tryptophan (Trp) residues of the native molecule between 15 and 30 min of radiation. The higher duration of the perturbation leads to a compact structure of the protein and Trp residues are buried again. Interestingly, we do not find any change in the secondary structure of the protein even for 1 h duration of radiation. The relaxation dynamics of the irradiated molecules also has been discussed. We have shown that the molecules relax to their native configuration in 7-8 h after the radiation field is turned off. The structural rearrangement over the above timescale has further been probed by a model calculation, based on a modified Langevin equation. Our coarse-grained simulation approach utilizes the mean of atomic positions and net atomic charge of each amino acid of native HEWL to mimic the initial conformation of the molecule. The modified positions of the residues are then calculated for the given force fields. The simulation results reveal the nonmonotonous change in overall size of the molecule, as observed experimentally. The radiation parameters used in our experiments are very similar to those of some of the electronic devices we often come across. Thus, we believe that the results of our studies on a simple protein structure may help us in understanding the effect of radiation on complex biological systems as well.

  7. Mobile phone base station-emitted radiation does not induce phosphorylation of Hsp27.

    Science.gov (United States)

    Hirose, H; Sakuma, N; Kaji, N; Nakayama, K; Inoue, K; Sekijima, M; Nojima, T; Miyakoshi, J

    2007-02-01

    An in vitro study focusing on the effects of low-level radiofrequency (RF) fields from mobile radio base stations employing the International Mobile Telecommunication 2000 (IMT-2000) cellular system was conducted to test the hypothesis that modulated RF fields act to induce phosphorylation and overexpression of heat shock protein hsp27. First, we evaluated the responses of human cells to microwave exposure at a specific absorption rate (SAR) of 80 mW/kg, which corresponds to the limit of the average whole-body SAR for general public exposure defined as a basic restriction in the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines. Second, we investigated whether continuous wave (CW) and Wideband Code Division Multiple Access (W-CDMA) modulated signal RF fields at 2.1425 GHz induced activation or gene expression of hsp27 and other heat shock proteins (hsps). Human glioblastoma A172 cells were exposed to W-CDMA radiation at SARs of 80 and 800 mW/kg for 2-48 h, and CW radiation at 80 mW/kg for 24 h. Human IMR-90 fibroblasts from fetal lungs were exposed to W-CDMA at 80 and 800 mW/kg for 2 or 28 h, and CW at 80 mW/kg for 28 h. Under the RF field exposure conditions described above, no significant differences in the expression levels of phosphorylated hsp27 at serine 82 (hsp27[pS82]) were observed between the test groups exposed to W-CDMA or CW signal and the sham-exposed negative controls, as evaluated immediately after the exposure periods by bead-based multiplex assays. Moreover, no noticeable differences in the gene expression of hsps were observed between the test groups and the negative controls by DNA Chip analysis. Our results confirm that exposure to low-level RF field up to 800 mW/kg does not induce phosphorylation of hsp27 or expression of hsp gene family.

  8. The effect of electromagnetic radiation emitted by display screens on cell oxygen metabolism - in vitro studies.

    Science.gov (United States)

    Lewicka, Małgorzata; Henrykowska, Gabriela A; Pacholski, Krzysztof; Śmigielski, Janusz; Rutkowski, Maciej; Dziedziczak-Buczyńska, Maria; Buczyński, Andrzej

    2015-12-10

    Research studies carried out for decades have not solved the problem of the effect of electromagnetic radiation of various frequency and strength on the human organism. Due to this fact, we decided to investigate the changes taking place in human blood platelets under the effect of electromagnetic radiation (EMR) emitted by LCD monitors. The changes of selected parameters of oxygen metabolism were measured, i.e. reactive oxygen species concentration, enzymatic activity of antioxidant defence proteins - superoxide dismutase (SOD-1) and catalase (CAT) - and malondialdehyde concentration (MDA). A suspension of human blood platelets was exposed to electromagnetic radiation of 1 kHz frequency and 150 V/m and 220 V/m intensity for 30 and 60 min. The level of changes of the selected parameters of oxidative stress was determined after the exposure and compared to the control samples (not exposed). The measurements revealed an increase of the concentration of reactive oxygen species. The largest increase of ROS concentration vs. the control sample was observed after exposure to EMF of 220 V/m intensity for 60 min (from x = 54.64 to x = 72.92). The measurement of MDA concentration demonstrated a statistically significant increase after 30-min exposure to an EMF of 220 V/m intensity in relation to the initial values (from x = 3.18 to x = 4.41). The enzymatic activity of SOD-1 decreased after exposure (the most prominent change was observed after 60-min and 220 V/m intensity from x = 3556.41 to x = 1084.83). The most significant change in activity of catalase was observed after 60 min and 220 v/m exposure (from x = 6.28 to x = 4.15). The findings indicate that exposure to electromagnetic radiation of 1 kHz frequency and 150 V/m and 220 V/m intensity may cause adverse effects within blood platelets' oxygen metabolism and thus may lead to physiological dysfunction of the organism.

  9. Features of interaction of fullerenes with microwave radiation

    International Nuclear Information System (INIS)

    Venger, E.F.; Konakova, R.V.; Kolyadina, E.Yu.; Matveeva, L.A.; Nelyuba, P.L.; Shinkarenko, V.V.

    2015-01-01

    Hetero systems with C 6 0 fullerenes were obtained by thermal sublimation method of microcrystalline C 6 0 powder from effusion tantalum cell in vacuum at a pressure of 10 -4 Pa onto non-heated silicon substrates. Composition, structural perfection and electronic properties, internal mechanical stresses in the films and the substrate at the interface, the influence on them of electromagnetic radiation (frequency of 2.45 GHz, power of 1.5 W/cm 2 ) were studied. Investigations were carried out by atomic force microscopy, Raman spectroscopy, electro reflectance modulation spectroscopy and hetero systems profilography to determine the sign and magnitude of mechanical stresses. There was the possibility of obtaining heterostructures with fullerenes without mechanical stress and the decomposition of the C 6 0 molecules in the film. Improvement of electronic properties of the films and the substrate was determined by the shift and value of transition energy Eg. This decreases the phenomenological broadening parameter Γ, increases the energy relaxation time of charge carriers τ and their mobility μ. For the first time determined the change of the fullerenes band gap depending on availability of internal mechanical stresses in the film: - 2.8×10 -10 eV/Pa and - 4.2×10 -10 eV/Pa for E0 and E0' transitions, respectively. (authors)

  10. The Effect of 2.45 GHz Microwave Radiation on Brain Cell Apoptosis in Sprague Dawley Rats

    International Nuclear Information System (INIS)

    Wan Saffiey Wan Abdullah; Rozaimah Abdul Rahim; Zulkifli Yusof

    2016-01-01

    Microwave radiation is a part of non-ionizing electromagnetic radiations present in the environment and is now being perceived as health risks. The study was performed to investigate the effect of 2.45 GHz microwave radiation on brain cell apoptosis in Sprague Dawley rat. In the research done, 32 Sprague Dawley rat were used and divided into four groups; control group, G1 (1 month exposure), G2 (2 months exposure) and G3 (3 months exposure). The presence of apoptotic activity in control group was compared molecularly with exposed group through DNA ladder test. Each exposed group were irradiated in GTEM cell at frequency of 2.45 GHz located at RF/ MW laboratory. There was presence of necrotic instead of apoptotic activity in brain cell and increase in weight of Sprague Dawley rat. Therefore the effect of 2.45GHz microwave radiation shown no presence of apoptosis and increase in weight of Sprague Dawley rat. (author)

  11. Searching for O-X-B mode-conversion window with monitoring of stray microwave radiation in LHD

    International Nuclear Information System (INIS)

    Igami, H.; Kubo, S.; Laqua, H. P.; Nagasaki, K.; Inagaki, S.; Notake, T.; Shimozuma, T.; Yoshimura, Y.; Mutoh, T.; LHD Experimental Group

    2006-01-01

    In the Large Helical Device, the stray microwave radiation is monitored by using so-called sniffer probes during electron cyclotron heating. In monitoring the stray radiation, we changed the microwave beam injection angle and search the O-X-B mode-conversion window to excite electron Bernstein waves (EBWs). When the microwave beam is injected toward the vicinity of the predicted O-X-B mode-conversion window, the electron temperature rises in the central part of overdense plasmas. In that case, the stray radiation level near the injection antenna becomes low. These results indicate that monitoring the stray radiation near the injection antenna is helpful in confirming the effectiveness of excitation of EBWs simply without precise analysis

  12. Effects of radiofrequency radiation emitted by cellular telephones on the cognitive functions of humans.

    Science.gov (United States)

    Eliyahu, Ilan; Luria, Roy; Hareuveny, Ronen; Margaliot, Menachem; Meiran, Nachshon; Shani, Gad

    2006-02-01

    The present study examined the effects of exposure to Electromagnetic Radiation emitted by a standard GSM phone at 890 MHz on human cognitive functions. This study attempted to establish a connection between the exposure of a specific area of the brain and the cognitive functions associated with that area. A total of 36 healthy right-handed male subjects performed four distinct cognitive tasks: spatial item recognition, verbal item recognition, and two spatial compatibility tasks. Tasks were chosen according to the brain side they are assumed to activate. All subjects performed the tasks under three exposure conditions: right side, left side, and sham exposure. The phones were controlled by a base station simulator and operated at their full power. We have recorded the reaction times (RTs) and accuracy of the responses. The experiments consisted of two sections, of 1 h each, with a 5 min break in between. The tasks and the exposure regimes were counterbalanced. The results indicated that the exposure of the left side of the brain slows down the left-hand response time, in the second-later-part of the experiment. This effect was apparent in three of the four tasks, and was highly significant in only one of the tests. The exposure intensity and its duration exceeded the common exposure of cellular phone users.

  13. The Usefulness Cytogenetic Biomarkers in Assessment of Occupational Exposure to Microwave Radiation

    International Nuclear Information System (INIS)

    Garaj-Vrhovac, V.; Kopjar, N.

    2003-01-01

    In recent years there has been growing interest in the health effects of the electromagnetic radiation's designated extremely low frequency (ELF) and radiofrequency radiation (RFR). Available data on cytogenetic consequences of microwave exposure on the induction of chromosome damage are contradictory, mostly because of different experimental conditions of in vitro and in vivo studies. It has been suggested that exposure to radiofrequency radiation may have genetic effects, which predispose to the development of cancer or birth defects. For the detection of early biological effects of DNA-damaging agents, well-established cytogenetic biomarkers are used. Comet assay was also successfully introduced detection of primary DNA damage and micronucleus assay for simultaneous detection of chromosome damage and spindle disfunction. The chromatid breakage assay, allowing selection of persons with a defect in DNA repair, is also an additional marker in human biomonitoring. Susceptibility to bleomycin-induced chromatid breaks in cultured peripheral blood lymphocytes may reflect the way a person deals with carcinogenic challenges. The objective of the present study the assessment of primary DNA damage, chromosome and spindle disfunctions as well as the mutagen sensitivity in peripheral blood leukocytes in radar-facility workers daily exposed to microwave radiation and corresponding control. As sensitive biomarkers three endpoints were chosen: the alkaline comet assay, micronucleus assay and chromatid breakage assay (bleomycin sensitivity test). A large number of experimental and epidemiological studies have been carried out to elucidate the possible health hazards associated with human exposure to ELF or RF electromagnetic fields. The results presented here indicate that the alkaline comet assay, as reliable biomarker of exposure, can be successfully applied in study of DNA damaging effects in microwave exposed subjects. The fact that the comet assay is a microdosimetric

  14. Effects of low power microwave radiation on biological activity of Collagenase enzyme and growth rate of S. Cerevisiae yeast

    Science.gov (United States)

    Alsuhaim, Hamad S.; Vojisavljevic, Vuk; Pirogova, E.

    2013-12-01

    Recently, microwave radiation, a type/subset of non-ionizing electromagnetic radiation (EMR) has been widely used in industry, medicine, as well as food technology and mobile communication. Use of mobile phones is rapidly growing. Four years from now, 5.1 billion people will be mobile phone users around the globe - almost 1 billion more mobile users than the 4.3 billion people worldwide using them now. Consequently, exposure to weak radiofrequency/microwave radiation generated by these devices is markedly increasing. Accordingly, public concern about potential hazards on human health is mounting [1]. Thermal effects of radiofrequency/microwave radiation are very well-known and extensively studied. Of particular interest are non-thermal effects of microwave exposures on biological systems. Nonthermal effects are described as changes in cellular metabolism caused by both resonance absorption and induced EMR and are often accompanied by a specific biological response. Non-thermal biological effects are measurable changes in biological systems that may or may not be associated with adverse health effects. In this study we studied non-thermal effects of low power microwave exposures on kinetics of L-lactate dehydrogenase enzyme and growth rate of yeast Saccharomyces Cerevisiae strains type II. The selected model systems were continuously exposed to microwave radiation at the frequency of 968MHz and power of 10dBm using the designed and constructed (custom made) Transverse Electro-Magnetic (TEM) cell [2]. The findings reveal that microwave radiation at 968MHz and power of 10dBm inhibits L-lactate dehydrogenase enzyme activity by 26% and increases significantly (15%) the proliferation rate of yeast cells.

  15. Biological effects of exposure to non-ionising electromagnetic fields and radiation: III radiofrequency and microwave radiation

    International Nuclear Information System (INIS)

    Saunders, R.D.; Kowalczuk, C.I.; Sienkiewicz, Z.J.

    1991-12-01

    The biological effects of experimental exposure to radiofrequency (RF) and microwave radiation above 100 kHz are reviewed with the intention of providing a summary of effects directly relevant to considerations of the health and safety of exposed people. The biological bases for restricting exposures are also briefly discussed. Studies of the possible effects of electromagnetic field exposure on human populations are described in a separate report. The majority of the biological effects of acute exposure to radiofrequency (RF) and microwave radiation are consistent with responses to induced heating, resulting either from frank rises in tissue or body temperature of about 1 0 C or more, or from responses involved in minimising the total heat load. Most responses have been reported at specific energy absorption rates (SARs) above about 1-2 W kg -1 in different animal species exposed under various environmental conditions. These animal, particularly primate, data indicate the sorts of responses that are likely to occur in humans subject to a sufficient heat load. In addition, most animal and cell culture data indicate that RF and microwave exposure is not mutagenic and so will not result in somatic mutation or in hereditary effects; such exposure is therefore unlikely to initiate cancers. With some exceptions that are described below, restrictions on the acute exposure of humans to RF or microwave radiation should be based on the acute responses to raised body temperature. It seems probable that healthy people can tolerate short-term (minute-hour) rises in body temperature of up to about 1 0 C. This rise is well below the maximum tolerable increase but nevertheless represents a significant thermal load. The evidence suggests that the exposure of resting humans in moderate environments at whole-body SARs of 1 W kg -1 , and up to 4 W kg -1 for short periods, will result in body temperature rises of less than 1 0 C. A restriction of whole-body SAR for healthy people to 0

  16. Occupational exposure to radio frequency/microwave radiation and the risk of brain tumors

    DEFF Research Database (Denmark)

    Berg, Gabriele; Spallek, Jacob; Schüz, Joachim

    2006-01-01

    It is still under debate whether occupational exposure to radio frequency/microwave electromagnetic fields (RF/MW-EMF) contributes to the development of brain tumors. This analysis examined the role of occupational RF/MW-EMF exposure in the risk of glioma and meningioma. A population-based, case....... "High" exposure was defined as an occupational exposure that may exceed the RF/MW-EMF exposure limits for the general public recommended by the International Commission on Non-Ionizing Radiation Protection. Multiple conditional logistic regressions were performed separately for glioma and meningioma...

  17. Fast microwave detection system for coherent synchrotron radiation study at KEK: Accelerator test facility

    International Nuclear Information System (INIS)

    Aryshev, A.; Araki, S.; Karataev, P.; Naito, T.; Terunuma, N.; Urakawa, J.

    2007-01-01

    A fast room temperature microwave detection system based on the Schottky Barrier-diode detector was created at the KEK ATF (Accelerator Test Facility). It was tested using Coherent Synchrotron Radiation (CSR) generated by the 1.28 GeV electron beam in the damping ring. The speed performance of the detection system was checked by observing the CSR from a multi-bunch (2.8 ns bunch separation time) beam. The theoretical estimations of CSR power yield from an edge of bending magnet as well as new injection tuning method are presented. A very high sensitivity of CSR power yield to the longitudinal electron distribution in a bunch is discussed

  18. Second dip as a signature of ultrahigh energy proton interactions with cosmic microwave background radiation.

    Science.gov (United States)

    Berezinsky, V; Gazizov, A; Kachelrieb, M

    2006-12-08

    We discuss as a new signature for the interaction of extragalactic ultrahigh energy protons with cosmic microwave background radiation a spectral feature located at E= 6.3 x 10(19) eV in the form of a narrow and shallow dip. It is produced by the interference of e+e(-)-pair and pion production. We show that this dip and, in particular, its position are almost model-independent. Its observation by future ultrahigh energy cosmic ray detectors may give the conclusive confirmation that an observed steepening of the spectrum is caused by the Greisen-Zatsepin-Kuzmin effect.

  19. Theoretical investigations of the anisotropy of the cosmic microwave background radiation

    International Nuclear Information System (INIS)

    Wilson, M.L.

    1981-01-01

    In this work, the anisotropy of the cosmic microwave background radiation is calculated within the context of the standard Big Bang cosmological model. The results of the calculations for different initial conditions are compared to the observational data available in order to try to learn more about conditions in the early universe. It is found that a model which has isothermal fluctuations superimposed on the standard model can explain all of the observations so far. In fact, a range of models with different initial densities can explain the observations. There is not enough information at present to choose among these models, but more data should be available in the near future

  20. Small-scale fluctuations in the microwave background radiation and multiple gravitational lensing

    International Nuclear Information System (INIS)

    Kashlinsky, A.

    1988-01-01

    It is shown that multiple gravitational lensing of the microwave background radiation (MBR) by static compact objects significantly attenuates small-scale fluctuations in the MBR. Gravitational lensing, by altering trajectories of MBR photons reaching an observer, leads to (phase) mixing of photons from regions with different initial fluctuations. As a result of this diffusion process the original fluctuations are damped on scales up to several arcmin. An equation that describes this process and its general solution are given. It is concluded that the present upper limits on the amplitude of the MBR fluctuations on small scales cannot constrain theories of galaxy formation. 25 references

  1. Constraining neutrino physics with big bang nucleosynthesis and cosmic microwave background radiation

    International Nuclear Information System (INIS)

    Hansen, S.H.; Melchiorri, A.; Mangano, G.; Miele, G.; Pisanti, O.

    2002-01-01

    We perform a likelihood analysis of the recent results on the anisotropy of cosmic microwave background radiation from the BOOMERanG and DASI experiments to show that they single out an effective number of neutrinos in good agreement with standard big bang nucleosynthesis. We also consider degenerate big bang nucleosynthesis to provide new bounds on effective relativistic degrees of freedom N ν and, in particular, on the neutrino chemical potential ξ α . When including supernova type Ia data we find, at 2σ, N ν ≤7 and -0.01≤ξ e ≤0.22, vertical bar ξ μ,τ vertical bar ≤2.6

  2. Can the anisotropy of microwave background radiation be discovered at present?

    International Nuclear Information System (INIS)

    Gurzadyan, V.G.; Kocharyan, A.A.

    1990-10-01

    An effect leading to a decrease of perturbations of Microwave Background Radiation after recombination epoch is investigated. Behaviour of correlation functions for null geodesics flow enables one to evaluate the role of this effect based purely on geometrical and topological properties of the Universe. Possible anisotropy of MwB in open Friedmannian Universe is shown to decrease due to this effect to a level far below present experimental accuracy. The fractal nature of the large scale structure of the Universe is also discussed. (author). 20 refs

  3. Ralph A. Alpher, Robert C. Herman, and the Cosmic Microwave Background Radiation

    Science.gov (United States)

    Alpher, Victor S.

    2012-09-01

    Much of the literature on the history of the prediction and discovery of the Cosmic Microwave Background Radiation (CMBR) is incorrect in some respects. I focus on the early history of the CMBR, from its prediction in 1948 to its measurement in 1964, basing my discussion on the published literature, the private papers of Ralph A. Alpher, and interviews with several of the major figures involved in the prediction and measurement of the CMBR. I show that the early prediction of the CMBR continues to be widely misunderstood.

  4. Development of radiation detectors based on KMgF3:Tb nano crystals synthesized by microwave

    International Nuclear Information System (INIS)

    Herrero C, R.; Villicana M, M.; Garcia S, L.; Custodio C, M. A.; Gonzalez M, P. R.; Mendoza A, D.

    2015-10-01

    The development of new thermoluminescent (Tl) materials of the size of KMgF 3 :Tb nano crystals by microwave technique is a new alternative for obtaining new radiation detectors (dosimeters) for environmental dosimetry, personal, clinical, research and industry. This technique requires the preparation of the precursors of magnesium trifluoro acetates Mg(CF 3 COO) 2 and potassium K(CF 3 COO), finally the synthesis of KMgF 3 :Tb is realized via microwave. The synthesis was carried out in a microwave reactor mono wave 300 Anton-Paar. Trifluoro acetates are introduced into the reactor at a ratio of 1:1 mmol under inert atmosphere. The product was collected for centrifugation, washed several times with ethanol and dried at 60 degrees C for 10 h. The KMgF 3 obtained without doping and doped with Tb +3 ions were subjected to heat treatment at high temperatures for different lengths of time for their sensitization, the samples treated at 700 degrees C were those showing better Tl signal to be irradiated with gammas of 60 Co. The characterization of the obtained materials was carried out by X-ray diffraction, scanning electron microscopy and thermogravimetric analysis. (Author)

  5. Microwave-signal generation in a planar Gunn diode with radiation exposure taken into account

    Energy Technology Data Exchange (ETDEWEB)

    Obolenskaya, E. S., E-mail: bess009@mail.ru, E-mail: obolensk@rf.unn.ru; Tarasova, E. A.; Churin, A. Yu.; Obolensky, S. V. [Lobachevsky State University of Nizhny Novgorod (NNSU) (Russian Federation); Kozlov, V. A. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation)

    2016-12-15

    Microwave-signal generation in planar Gunn diodes with a two-dimensional electron gas, in which we previously studied steady-state electron transport, is theoretically studied. The applicability of a control electrode similar to a field-effect transistor gate to control the parameters of the output diode microwave signal is considered. The results of physical-topological modeling of semiconductor structures with different diode active-region structures, i.e., without a quantum well, with one and two quantum wells separated by a potential barrier, are compared. The calculated results are compared with our previous experimental data on recording Gunn generation in a Schottky-gate field-effect transistor. It is theoretically and experimentally shown that the power of the signal generated by the planar Gunn diode with a quantum well and a control electrode is sufficient to implement monolithic integrated circuits of different functionalities. It is theoretically and experimentally shown that the use of a control electrode on account of the introduction of corrective feedback allows a significant increase in the radiation resistance of a microwave generator with Schottky-gate field-effect transistors.

  6. Microwave-signal generation in a planar Gunn diode with radiation exposure taken into account

    International Nuclear Information System (INIS)

    Obolenskaya, E. S.; Tarasova, E. A.; Churin, A. Yu.; Obolensky, S. V.; Kozlov, V. A.

    2016-01-01

    Microwave-signal generation in planar Gunn diodes with a two-dimensional electron gas, in which we previously studied steady-state electron transport, is theoretically studied. The applicability of a control electrode similar to a field-effect transistor gate to control the parameters of the output diode microwave signal is considered. The results of physical-topological modeling of semiconductor structures with different diode active-region structures, i.e., without a quantum well, with one and two quantum wells separated by a potential barrier, are compared. The calculated results are compared with our previous experimental data on recording Gunn generation in a Schottky-gate field-effect transistor. It is theoretically and experimentally shown that the power of the signal generated by the planar Gunn diode with a quantum well and a control electrode is sufficient to implement monolithic integrated circuits of different functionalities. It is theoretically and experimentally shown that the use of a control electrode on account of the introduction of corrective feedback allows a significant increase in the radiation resistance of a microwave generator with Schottky-gate field-effect transistors.

  7. Removal of ammonia nitrogen in wastewater by microwave radiation: A pilot-scale study

    International Nuclear Information System (INIS)

    Lin Li; Chen Jing; Xu Zuqun; Yuan Songhu; Cao Menghua; Liu Huangcheng; Lu Xiaohua

    2009-01-01

    A large removal of ammonia nitrogen in wastewater has been achieved by microwave (MW) radiation in our previous bench-scale study. This study developed a continuous pilot-scale MW system to remove ammonia nitrogen in real wastewater. A typical high concentration of ammonia nitrogen contaminated wastewater, the coke-plant wastewater from a Coke company, was treated. The output power of the microwave reactor was 4.8 kW and the handling capacity of the reactor was about 5 m 3 per day. The ammonia removal efficiencies under four operating conditions, including ambient temperature, wastewater flow rate, aeration conditions and initial concentration were evaluated in the pilot-scale experiments. The ammonia removal could reach about 80% for the real coke-plant wastewater with ammonia nitrogen concentrations of 2400-11000 mg/L. The running cost of the MW technique was a little lower than the conventional steam-stripping method. The continuous microwave system showed the potential as an effective method for ammonia nitrogen removal in coke-plant water treatment. It is proposed that this process is suitable for the treatment of toxic wastewater containing high concentrations of ammonia nitrogen.

  8. Decay Curves and Half-Lives of Gamma-Emitting States from a Study of Prompt Fission Gamma Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Albinsson, H [Chalmers Univ. of Technology, Goeteborg (SE)

    1971-04-15

    Measurements were made on the time distributions of the prompt gamma radiation emitted from fragments in the thermal-neutron induced fission of 235U. The gamma radiation emitted during different time intervals after the fission event was studied with the help of a collimator, the position of which was changed along the path of the fragments. In this way decay curves were obtained from which half-lives could be estimated. Time components with half-lives of 7.5, 18 and 60 ps were found and their relative intensities were calculated. Half-lives and associated intensities are in good agreement with earlier data from uranium and californium fission. Problems involved in this type of study are discussed. The collimator technique has proved to be effective for determination of half lives down to less than 10 ps

  9. Microwave hyperthermia as an adjuvant to radiation therapy. Summary experience of 256 multifraction treatment cases

    International Nuclear Information System (INIS)

    Bicher, H.I.

    1985-01-01

    Analysis is presented of a series of 256 human tumors treated under multifraction protocol regimes with standard controlled hyperthermia parameters and increasing doses of radiation therapy. Air cooled microwave applicators intracavitary and interstitial antennae operating at 915 or 300 MHz were used in various sites. Temperatures were measured by micro-thermocouples. Minimum tumor temperatures of 42 0 C were maintained at 1 hour, twice weekly. Treatment included a radiation dose of 1600-1700 rads. Tumor response was 94% with 60% or more total response. Frequency and duration of total responses depended mainly on the radiation dose. Skin tumors, melanomas, chest wall recurrences responded better than head and neck or intrapelvic recurrences. Side effects observed were minor burns; proctitis or oesophagitis with intracavitary devices; ulcerations or fistulae due to rapid tumor regression; 4 cases of pleuritis treating chest wall. Overall toxicity was less than 5%. In conclusion: 1) Combination heat-low dose radiation offers good palliation. 2) Response depends on radiation dose. 3) Combination of full dose radiation therapy plus hyperthermia proves to be well tolerated

  10. Numerically stable algorithm for discrete-ordinate-method radiative transfer in multiple scattering and emitting layered media

    Science.gov (United States)

    Stamnes, Knut; Tsay, S.-CHEE; Jayaweera, Kolf; Wiscombe, Warren

    1988-01-01

    The transfer of monochromatic radiation in a scattering, absorbing, and emitting plane-parallel medium with a specified bidirectional reflectivity at the lower boundary is considered. The equations and boundary conditions are summarized. The numerical implementation of the theory is discussed with attention given to the reliable and efficient computation of eigenvalues and eigenvectors. Ways of avoiding fatal overflows and ill-conditioning in the matrix inversion needed to determine the integration constants are also presented.

  11. Effect of 905 MHz microwave radiation on colony growth of the yeast Saccharomyces cerevisiae strains FF18733, FF1481 and D7

    International Nuclear Information System (INIS)

    Vrhovac, Ivana; Hrascan, Reno; Franekic, Jasna

    2010-01-01

    The aim of this study was to evaluate the effect of weak radiofrequency microwave (RF/MW) radiation emitted by mobile phones on colony growth of the yeast Saccharomyces cerevisiae. S. cerevisiae strains FF18733 (wild-type), FF1481 (rad1 mutant) and D7 (commonly used to detect reciprocal and nonreciprocal mitotic recombinations) were exposed to a 905 MHz electromagnetic field that closely matched the Global System for Mobile Communication (GSM) pulse modulation signals for mobile phones at a specific absorption rate (SAR) of 0.12 W/kg. Following 15-, 30- and 60-minutes exposure to RF/MW radiation, strain FF18733 did not show statistically significant changes in colony growth compared to the control sample. The irradiated strains FF1481 and D7 demonstrated statistically significant reduction of colony growth compared to non-irradiated strains after all exposure times. Furthermore, strain FF1481 was more sensitive to RF/MW radiation than strain D7. The findings indicate that pulsed RF/MW radiation at a low SAR level can affect the rate of colony growth of different S. cerevisiae strains

  12. Evaluation of scattered radiation emitted from X-ray security scanners on occupational dose to airport personnel

    International Nuclear Information System (INIS)

    Dalah, Entesar; Fakhry, Angham; Mukhtar, Asma; Al Salti, Farah; Bader, May; Khouri, Sara; Al-Zahmi, Reem

    2017-01-01

    Based on security issues and regulations airports are provided with luggage cargo scanners. These scanners utilize ionizing radiation that in principle present health risks toward humans. The study aims to investigate the amount of backscatter produced by passenger luggage and cargo toward airport personnel who are located at different distances from the scanners. To approach our investigation a Thermo Electron Radeye-G probe was used to quantify the backscattered radiation measured in terms of dose-rate emitted from airport scanners, Measurements were taken at the entrance and exit positions of the X-ray tunnel at three different distances (0, 50, and 100 cm) for two different scanners; both scanners include shielding curtains that reduce scattered radiation. Correlation was demonstrated using the Pearson coefficient test. Measurements confirmed an inverse relationship between dose rate and distance. An estimated occupational accumulative dose of 0.88 mSv/y, and 2.04 mSv/y were obtained for personnel working in inspection of carry-on, and cargo, respectively. Findings confirm that the projected dose of security and engineering staff are being well within dose limits. - Highlights: • Backscattered radiation emitted from the airport security scanners is estimated. • Inverse relation observed between backscattered radiation and scanners distance. • Occupational dose for personnel inspecting the scanners were up to 2.04 mSv/y. • The projected dose of security and engineering staff are well within dose limits.

  13. Improved carbon nanotube growth inside an anodic aluminum oxide template using microwave radiation

    Science.gov (United States)

    Dadras, Sedigheh; Faraji, Maryam

    2018-05-01

    In this study, we achieved superfast growth of carbon nanotubes (CNTs) in an anodic aluminum oxide (AAO) template by applying microwave (MW) radiation. This is a simple and direct approach for growing CNTs using a MW oven. The CNTs were synthesized using MW radiation at a frequency of 2.45 GHz and power was applied at various levels of 900, 600, and 450 W. We used graphite and ferrocene in equal portions as precursors. The optimum conditions for the growth of CNTs inside a MW oven were a time period of 5 s and power of 450 W. In order to grow uniform CNTs, an AAO template was applied with the CNTs synthesized under optimum conditions. The morphology of the synthesized CNTs was investigated by scanning electron microscopy analysis. The average diameters of the CNTs obtained without the template were 22-27 nm, whereas the diameters of the CNTs prepared inside the AAO template were about 4-6 nm.

  14. Synthesis of Graphite Oxide with Different Surface Oxygen Contents Assisted Microwave Radiation

    Directory of Open Access Journals (Sweden)

    Adriana Ibarra-Hernández

    2018-02-01

    Full Text Available Graphite oxide is synthesized via oxidation reaction using oxidant compounds that have lattice defects by the incorporation of unlike functional groups. Herein, we report the synthesis of the graphite oxide with diverse surface oxygen content through three (B, C, D different modified versions of the Hummers method assisted microwave radiation compared with the conventional graphite oxide sample obtained by Hummers method (A. These methods allow not only the production of graphite oxide but also reduced graphene oxide, without undergoing chemical, thermal, or mechanical reduction steps. The values obtained of C/O ratio were ~2, 3.4, and ~8.5 for methodologies C, B, and D, respectively, indicating the presence of graphite oxide and reduced graphene oxide, according to X-ray photoelectron spectroscopy. Raman spectroscopy of method D shows the fewest structural defects compared to the other methodologies. The results obtained suggest that the permanganate ion produces reducing species during graphite oxidation. The generation of these species is attributed to a reversible reaction between the permanganate ion with π electrons, ions, and radicals produced after treatment with microwave radiation.

  15. Observing the Cosmic Microwave Background Radiation: A Unique Window on the Early Universe

    Science.gov (United States)

    Hinshaw, Gary; Fisher, Richard R. (Technical Monitor)

    2001-01-01

    The cosmic microwave background radiation is the remnant heat from the Big Bang. It provides us with a unique probe of conditions in the early universe, long before any organized structures had yet formed. The anisotropy in the radiation's brightness yields important clues about primordial structure and additionally provides a wealth of information about the physics,of the early universe. Within the framework of inflationary dark matter models observations of the anisotropy on sub-degree angular scales will reveal the signatures of acoustic oscillations of the photon-baryon fluid at a redshift of approx. 1100. The validity of inflationary models will be tested and, if agreement is found, accurate values for most of the key cosmological parameters will result. If disagreement is found, we will need to rethink our basic ideas about the physics of the early universe. I will present an overview of the physical processes at work in forming the anisotropy and discuss what we have already learned from current observations. I will conclude with a brief overview of the recently launched Microwave Anisotropy Probe (MAP) mission which will observe the anisotropy over the full sky with 0.21 degree angular resolution. At the time of this meeting, MAP will have just arrived at the L2 Lagrange point, marking the start of its observing campaign. The MAP hardware is being produced by Goddard in partnership with Princeton University.

  16. The vertical pattern of microwave radiation around BTS (Base Transceiver Station) antennae in Hashtgerd township.

    Science.gov (United States)

    Nasseri, Simin; Monazzam, Mohammadreza; Beheshti, Meisam; Zare, Sajad; Mahvi, Amirhosein

    2013-12-20

    New environmental pollutants interfere with the environment and human life along with technology development. One of these pollutants is electromagnetic field. This study determines the vertical microwave radiation pattern of different types of Base Transceiver Station (BTS) antennae in the Hashtgerd city as the capital of Savojbolagh County, Alborz Province of Iran. The basic data including the geographical location of the BTS antennae in the city, brand, operator type, installation and its height was collected from radio communication office, and then the measurements were carried out according to IEEE STD 95. 1 by the SPECTRAN 4060. The statistical analyses were carried out by SPSS16 using Kolmogorov Smirnov test and multiple regression method. Results indicated that in both operators of Irancell and Hamrah-e-Aval (First Operator), the power density rose with an increase in measurement height or decrease in the vertical distance of broadcaster antenna. With mix model test, a significant statistical relationship was observed between measurement height and the average power density in both types of the operators. With increasing measuring height, power density increased in both operators. The study showed installing antennae in a crowded area needs more care because of higher radiation emission. More rigid surfaces and mobile users are two important factors in crowded area that can increase wave density and hence raise public microwave exposure.

  17. Estimation of soft X-ray and EUV transition radiation power emitted from the MIRRORCLE-type tabletop synchrotron.

    Science.gov (United States)

    Toyosugi, N; Yamada, H; Minkov, D; Morita, M; Yamaguchi, T; Imai, S

    2007-03-01

    The tabletop synchrotron light sources MIRRORCLE-6X and MIRRORCLE-20SX, operating at electron energies E(el) = 6 MeV and E(el) = 20 MeV, respectively, can emit powerful transition radiation (TR) in the extreme ultraviolet (EUV) and the soft X-ray regions. To clarify the applicability of these soft X-ray and EUV sources, the total TR power has been determined. A TR experiment was performed using a 385 nm-thick Al foil target in MIRRORCLE-6X. The angular distribution of the emitted power was measured using a detector assembly based on an NE102 scintillator, an optical bundle and a photomultiplier. The maximal measured total TR power for MIRRORCLE-6X is P(max) approximately equal 2.95 mW at full power operation. Introduction of an analytical expression for the lifetime of the electron beam allows calculation of the emitted TR power by a tabletop synchrotron light source. Using the above measurement result, and the theoretically determined ratio between the TR power for MIRRORCLE-6X and MIRRORCLE-20SX, the total TR power for MIRRORCLE-20SX can be obtained. The one-foil TR target thickness is optimized for the 20 MeV electron energy. P(max) approximately equal 810 mW for MIRRORCLE-20SX is obtained with a single foil of 240 nm-thick Be target. The emitted bremsstrahlung is negligible with respect to the emitted TR for optimized TR targets. From a theoretically known TR spectrum it is concluded that MIRRORCLE-20SX can emit 150 mW of photons with E > 500 eV, which makes it applicable as a source for performing X-ray lithography. The average wavelength, \\overline\\lambda = 13.6 nm, of the TR emission of MIRRORCLE-20SX, with a 200 nm Al target, could provide of the order of 1 W EUV.

  18. Assessment of radiation emitted by the colour video monitors using a silicon surface-barrier detection system

    International Nuclear Information System (INIS)

    Tykva, R.; Sabol, J.

    1998-01-01

    About 5% of the commonly used colour monitors tested showed radiation levels on the screen surface approaching the dose rate of 5 μGy/h. There is practically no difference between 'low radiation' monitors and other monitors. The level of radiation emitted to the sides is generally higher than that of X-ray photons emerging from the surface of the screen. Although the contribution to the effective dose of a person exposed to radiation from the monitors may be below the limit set for the general public, the skin and eye lens dose may reach significant levels, taking into account some factors such as a high density of monitors in small rooms, short distance, long exposure time, etc. (M.D.)

  19. Radioprotection of Wistar Rat Lymphocytes Against Microwave Radiation Mediated by Bee Venom

    International Nuclear Information System (INIS)

    Garaj-Vrhovac, V.; Gajski, G.

    2011-01-01

    Microwave radiation is a type of non-ionising electromagnetic radiation present in the environment, and is a potential threat to human health. Cytogenetic studies of microwave radiation conducted in vitro and in vivo, yielded contradictory and often intriguing experimental results. Some reports suggest that exposure of human cells to radiofrequency radiation does not result in increased cytogenetic damage. On the other hand, there is a range of studies showing that radiofrequency radiation can indeed induce genetic alteration after exposure to electric field. Bee venom is used in traditional medicine to treat variety of conditions, such as arthritis, rheumatism, back pain and skin disease. In recent years it has been reported that bee venom possesses antimutagenic, proinflammatory, anti-inflammatory, antinociceptive, and anticancer effects. In addition to the wide range of the bee venom's activities, it also possesses a radioprotective capacity that was noted against X-ray and gamma radiation in various test systems. The aim of the present study was assessment of the radioprotective effect of bee venom against 915 MHz microwave radiation-induced DNA damage in the Wistar rat's lymphocytes in vitro. The possible genotoxic effect of bee venom alone was also assessed on non-irradiated lymphocytes. The alkaline comet assay was used as a sensitive tool in The assessment of DNA damage was performed using the alkaline comet assay and the Fpg-modified comet assay that is more specific technique in detection of DNA strand breaks and oxidative stress. Whole blood was collected from adult male Wistar rats (11 weeks old, approximate body weight 350 g)by cardiac puncture under sterile conditions in heparinized vacutainer tubes. After collection, blood was divided into 1 ml aliquots and placed into 24-well culture plates according to the exposure conditions. Bee venom was added to lymphocyte cultures in final concentration of 1 μg/ml, 4 h prior to irradiation and immediately

  20. Optical spectroscopy and microscopy of radiation-induced light-emitting point defects in lithium fluoride crystals and films

    Science.gov (United States)

    Montereali, R. M.; Bonfigli, F.; Menchini, F.; Vincenti, M. A.

    2012-08-01

    Broad-band light-emitting radiation-induced F2 and F3+ electronic point defects, which are stable and laser-active at room temperature in lithium fluoride crystals and films, are used in dosimeters, tuneable color-center lasers, broad-band miniaturized light sources and novel radiation imaging detectors. A brief review of their photoemission properties is presented, and their behavior at liquid nitrogen temperatures is discussed. Some experimental data from optical spectroscopy and fluorescence microscopy of these radiation-induced point defects in LiF crystals and thin films are used to obtain information about the coloration curves, the efficiency of point defect formation, the effects of photo-bleaching processes, etc. Control of the local formation, stabilization, and transformation of radiation-induced light-emitting defect centers is crucial for the development of optically active micro-components and nanostructures. Some of the advantages of low temperature measurements for novel confocal laser scanning fluorescence microscopy techniques, widely used for spatial mapping of these point defects through the optical reading of their visible photoluminescence, are highlighted.

  1. Combined Natural Convection and Radiation Heat Transfer of Various Absorbing-Emitting-Scattering Media in a Square Cavity

    Directory of Open Access Journals (Sweden)

    Xianglong Liu

    2014-01-01

    Full Text Available A numerical model is developed to simulate combined natural convection and radiation heat transfer of various anisotropic absorbing-emitting-scattering media in a 2D square cavity based on the discrete ordinate (DO method and Boussinesq assumption. The effects of Rayleigh number, optical thickness, scattering ratio, scattering phase function, and aspect ratio of square cavity on the behaviors of heat transfer are studied. The results show that the heat transfer of absorbing-emitting-scattering media is the combined results of radiation and natural convection, which depends on the physical properties and the aspect ratio of the cavity. When the natural convection becomes significant, the convection heat transfer is enhanced, and the distributions of NuR and Nuc along the walls are obviously distorted. As the optical thickness increases, NuR along the hot wall decreases. As the scattering ratio decreases, the NuR along the walls decreases. At the higher aspect ratio, the more intensive thermal radiation and natural convection are formed, which increase the radiation and convection heat fluxes. This paper provides the theoretical research for the optimal thermal design and practical operation of the high temperature industrial equipments.

  2. Study of federal microwave standards

    Energy Technology Data Exchange (ETDEWEB)

    David, L.

    1980-08-01

    Present and future federal regulatory processes which may impact the permissible levels of microwave radiation emitted by the SPS Microwave Power Transmission (MPTS) were studied. An historical development of US occupational and public microwave standards includes an overview of Western and East European philosophies of environmental protection and neurophysiology which have led to the current widely differing maximum permissible exposure limits to microwaves. The possible convergence of microwave standards is characterized by a lowering of Western exposure levels while Eastern countries consider standard relaxation. A trend toward stricter controls on activities perceived as harmful to public health is under way as is interest in improving the federal regulatory process. Particularly relevant to SPS is the initiation of long-term, low-level microwave exposure programs. Coupled with new developments in instrumentation and dosimetry, the results from chronic exposure program and population exposure studies could be expected within the next five to ten years. Also discussed is the increasing public concern that rf energy is yet another hazardous environmental agent.

  3. Effect of microwave (24 GHz) radiation treatment on impurity photoluminescence of CdTe:Cl single crystals

    International Nuclear Information System (INIS)

    Red'ko, R.A.; Budzulyak, S.I.; Vakhnyak, N.D.; Demchina, L.A.; Korbutyak, D.V.; Konakova, R.V.; Lotsko, A.P.; Okhrimenko, O.B.; Berezovskaya, N.I.; Bykov, Yu.V.; Egorov, S.V.; Eremeev, A.G.

    2016-01-01

    Effect of microwave radiation (24 GHz) on transformation of impurity-defect complexes in CdTe:Cl single crystals within the spectral range 1.3–1.5 eV was studied using the low-temperature (T=2 K) photoluminescence (PL) technique. The shapes of donor–acceptor pairs (DAP) and Y PL bands were studied in detail. The Huang–Rhys factor was calculated for the DAP luminescence depending on microwave radiation treatment. The increase of the distance between the DAP components responsible for emission at 1.455 eV and the quenching of Y-band due to microwave irradiation were observed. The method to decrease the amount of extended defects in near-surface layers of CdTe:Cl single crystals has been proposed.

  4. X-ray Emitting GHz-Peaked Spectrum Galaxies: Testing a Dynamical-Radiative Model with Broad-Band Spectra

    International Nuclear Information System (INIS)

    Ostorero, L.; Moderski, R.; Stawarz, L.; Diaferio, A.; Kowalska, I.; Cheung, C.C.; Kataoka, J.; Begelman, M.C.; Wagner, S.J.

    2010-01-01

    In a dynamical-radiative model we recently developed to describe the physics of compact, GHz-Peaked-Spectrum (GPS) sources, the relativistic jets propagate across the inner, kpc-sized region of the host galaxy, while the electron population of the expanding lobes evolves and emits synchrotron and inverse-Compton (IC) radiation. Interstellar-medium gas clouds engulfed by the expanding lobes, and photoionized by the active nucleus, are responsible for the radio spectral turnover through free-free absorption (FFA) of the synchrotron photons. The model provides a description of the evolution of the GPS spectral energy distribution (SED) with the source expansion, predicting significant and complex high-energy emission, from the X-ray to the γ-ray frequency domain. Here, we test this model with the broad-band SEDs of a sample of eleven X-ray emitting GPS galaxies with Compact-Symmetric-Object (CSO) morphology, and show that: (i) the shape of the radio continuum at frequencies lower than the spectral turnover is indeed well accounted for by the FFA mechanism; (ii) the observed X-ray spectra can be interpreted as non-thermal radiation produced via IC scattering of the local radiation fields off the lobe particles, providing a viable alternative to the thermal, accretion-disk dominated scenario. We also show that the relation between the hydrogen column densities derived from the X-ray (N H ) and radio (N HI ) data of the sources is suggestive of a positive correlation, which, if confirmed by future observations, would provide further support to our scenario of high-energy emitting lobes.

  5. Microwave ablation devices for interventional oncology.

    Science.gov (United States)

    Ward, Robert C; Healey, Terrance T; Dupuy, Damian E

    2013-03-01

    Microwave ablation is one of the several options in the ablation armamentarium for the treatment of malignancy, offering several potential benefits when compared with other ablation, radiation, surgical and medical treatment modalities. The basic microwave system consists of the generator, power distribution system and antennas. Often under image (computed tomography or ultrasound) guidance, a needle-like antenna is inserted percutaneously into the tumor, where local microwave electromagnetic radiation is emitted from the probe's active tip, producing frictional tissue heating, capable of causing cell death by coagulation necrosis. Half of the microwave ablation systems use a 915 MHz generator and the other half use a 2450 MHz generator. To date, there are no completed clinical trials comparing microwave devices head-to-head. Prospective comparisons of microwave technology with other treatment alternatives, as well as head-to-head comparison with each microwave device, is needed if this promising field will garner more widespread support and use in the oncology community.

  6. Exposure to Radiofrequency Radiation Emitted from Common Mobile Phone Jammers Alters the Pattern of Muscle Contractions: an Animal Model Study

    Directory of Open Access Journals (Sweden)

    Rafati A.

    2015-09-01

    Full Text Available Introduction: The rapid growth of wireless communication technologies has caused public concerns regarding the biological effects of electromagnetic radiations on human health. Some early reports indicated a wide variety of non-thermal effects of electromagnetic radiation on amphibians such as the alterations of the pattern of muscle extractions. This study is aimed at investigating the effects of exposure to radiofrequency (RF radiation emitted from mobile phone jammers on the pulse height of contractions, the time interval between two subsequent contractions and the latency period of frog’s isolated gastrocnemius muscle after stimulation with single square pulses of 1V (1 Hz. Materials and Methods: Frogs were kept in plastic containers in a room. Animals in the jammer group were exposed to radiofrequency (RF radiation emitted from a common Jammer at a distance of 1m from the jammer’s antenna for 2 hours while the control frogs were only sham exposed. Then animals were sacrificed and isolated gastrocnemius muscles were exposed to on/off jammer radiation for 3 subsequent 10 minute intervals. Isolated gastrocnemius muscles were attached to the force transducer with a string. Using a PowerLab device (26-T, the pattern of muscular contractions was monitored after applying single square pulses of 1V (1 Hz as stimuli. Results: The findings of this study showed that the pulse height of muscle contractions could not be affected by the exposure to electromagnetic fields. However, the latency period was effectively altered in RF-exposed samples. However, none of the experiments could show an alteration in the time interval between two subsequent contractions after exposure to electromagnetic fields. Conclusion: These findings support early reports which indicated a wide variety of non-thermal effects of electromagnetic radiation on amphibians including the effects on the pattern of muscle extractions.

  7. Exposure to Radiofrequency Radiation Emitted from Common Mobile Phone Jammers Alters the Pattern of Muscle Contractions: an Animal Model Study.

    Science.gov (United States)

    Rafati, A; Rahimi, S; Talebi, A; Soleimani, A; Haghani, M; Mortazavi, S M J

    2015-09-01

    The rapid growth of wireless communication technologies has caused public concerns regarding the biological effects of electromagnetic radiations on human health. Some early reports indicated a wide variety of non-thermal effects of electromagnetic radiation on amphibians such as the alterations of the pattern of muscle extractions. This study is aimed at investigating the effects of exposure to radiofrequency (RF) radiation emitted from mobile phone jammers on the pulse height of contractions, the time interval between two subsequent contractions and the latency period of frog's isolated gastrocnemius muscle after stimulation with single square pulses of 1V (1 Hz). Frogs were kept in plastic containers in a room. Animals in the jammer group were exposed to radiofrequency (RF) radiation emitted from a common Jammer at a distance of 1m from the jammer's antenna for 2 hours while the control frogs were only sham exposed. Then animals were sacrificed and isolated gastrocnemius muscles were exposed to on/off jammer radiation for 3 subsequent 10 minute intervals. Isolated gastrocnemius muscles were attached to the force transducer with a string. Using a PowerLab device (26-T), the pattern of muscular contractions was monitored after applying single square pulses of 1V (1 Hz) as stimuli. The findings of this study showed that the pulse height of muscle contractions could not be affected by the exposure to electromagnetic fields. However, the latency period was effectively altered in RF-exposed samples. However, none of the experiments could show an alteration in the time interval between two subsequent contractions after exposure to electromagnetic fields. These findings support early reports which indicated a wide variety of non-thermal effects of electromagnetic radiation on amphibians including the effects on the pattern of muscle extractions.

  8. USE OF THE MICROWAVE RADIATION FOR UPGRADING OF A BIOMASS ALCOHOLIC FERMENTATION

    Directory of Open Access Journals (Sweden)

    Anna Nowicka

    2017-04-01

    Full Text Available Perform pretreatment is crucial particularly in the case of the use of hard-degradable biomass, the biochemical susceptibility to degradation, for example, alcoholic fermentation is limited. Biomass disintegration processes lead to the destruction of compact structures and release of the organic substance to the phase dissolved in a resultant increase in the concentration of dissolved easily degradable organic substances. Effective pretreatment should meet several criteria, including ensuring the separation of lignin from cellulose, to increase the share of amorphous cellulose, provide a higher porosity substrates, eliminate waste sugars limit formation of inhibitors, minimize energy costs. The aim of this paper is to show the possibilities of using electromagnetic microwave radiation for pre-treatment plant biomass before the fermentation process of alcohol and comparison of the effectiveness of the described method with other commonly used techniques of pre-treatment. The substrate subjected to microwave treatment has a fast rate of hydrolysis and a high content of glucose in the hydrolyzate, which increases the efficiency of the production of bioethanol.

  9. Large signal S-parameters: modeling and radiation effects in microwave power transistors

    International Nuclear Information System (INIS)

    Graham, E.D. Jr.; Chaffin, R.J.; Gwyn, C.W.

    1973-01-01

    Microwave power transistors are usually characterized by measuring the source and load impedances, efficiency, and power output at a specified frequency and bias condition in a tuned circuit. These measurements provide limited data for circuit design and yield essentially no information concerning broadbanding possibilities. Recently, a method using large signal S-parameters has been developed which provides a rapid and repeatable means for measuring microwave power transistor parameters. These large signal S-parameters have been successfully used to design rf power amplifiers. Attempts at modeling rf power transistors have in the past been restricted to a modified Ebers-Moll procedure with numerous adjustable model parameters. The modified Ebers-Moll model is further complicated by inclusion of package parasitics. In the present paper an exact one-dimensional device analysis code has been used to model the performance of the transistor chip. This code has been integrated into the SCEPTRE circuit analysis code such that chip, package and circuit performance can be coupled together in the analysis. Using []his computational tool, rf transistor performance has been examined with particular attention given to the theoretical validity of large-signal S-parameters and the effects of nuclear radiation on device parameters. (auth)

  10. Humoral immunity of Japanese quail subjected to microwave radiation during embryogeny

    International Nuclear Information System (INIS)

    Hamrick, P.E.; McRee, D.I.; Thaxton, P.; Parkhurst, C.R.

    1977-01-01

    Fertile Japanese quail eggs were exposed to continuous wave microwave radiation at an intensity of 5 mW/cm 2 (50 W/m 2 ) and a frequency of 2450 Mhz. The absorbed power density was determined to be 4.03 W/kg. The eggs were exposed throughout the first 12 days of the normal incubation period of 17.5 days. Non-exposed control eggs were incubated in a chamber identical to the exposure chamber. After hatching, exposed and control quail were reared in the conventional laboratory manner. Weekly body weight measurements were made to compare the growth patterns of exposed and control quail. The weights of the exposed male at the ages of 4 and 5 weeks were 12 and 7%, respectively, less than the control males. These differences approached statistical significance (P<=0.05). At 5 weeks of age the quail were challenged with sheep red blood cells (SRBC) and the levels of the anti-SRBC antibodies were determined. The levels of specific anti-SRBC antibodies, determined 4 days after antigen challenges, were of the same magnitude for both the exposed and control quail. Following this assessment of humoral immunity, the quail were sacrificed and the bursa of Fabricius and spleen were removed and a comparison was made of exposed and control birds. The weights of the bursa of Fabricius and spleen were not altered significantly by the microwave exposure. (author)

  11. Effect of Radiation Leakage of Microwave Oven on Rat Serum Testosterone at Pre and Post Pubertal Stage

    Directory of Open Access Journals (Sweden)

    Y Zare

    2008-01-01

    Full Text Available Introduction: Since discovery of high frequency waves, their biological effects have been in great attention. Increased male fertility problems proposed their possible relation to use of microwaves. Testes are of very active body tissues, which can be affected by these waves. Age of exposure may also be an important factor. Methods: This study was carried out to evaluated testosterone level in rats exposed to microwave radiation at pre and post puberty. For this study 18 adult (2 month old and 18 immature (1 month old male rats were selected and each group divided in two groups, control and test group. Test groups were exposed to 2450 MHZ microwaves produced by microwave oven (LG Brant, three times a day, 30 minute each time. Control groups were kept in laboratory at same temperature and light condition. After 60 days blood was collected by heart puncture and testosterone was measured in serum by RIA method. Mean testosterone levels were compared by T-test. Result: The results showed that in immature group testosterone has not changed significantly compare to control group; however in adult group this value was significantly decreased in test group in comparison with control (P<0.005. Conclusion: exposure to microwaves leakage of microwave oven decreased testosterone in adult male rats, which may be due to its direct effect on Leydig cells or indirectly through its effect on pituitary and hypothalamus.

  12. Glial reaction in visual centers upon whole-body combined irradiation with microwaves and x-radiation

    International Nuclear Information System (INIS)

    Logvinov, S.V.

    1989-01-01

    A single whole-body preirradiation with thermogenous microwaves modifies the dynamics of the glial reactions of visual centers of ginea pigs induced by median lethal X-radiation doses. A combination of the two factors products the synergistic effect, estimated by the degree of alteration of astrocytes and oligodendroglyocytes at early times after exposure, leads to early activation of microglia, and reduces radiation-induced alterations in glia at later times (25-60 days)

  13. High-energy coherent terahertz radiation emitted by wide-angle electron beams from a laser-wakefield accelerator

    Science.gov (United States)

    Yang, Xue; Brunetti, Enrico; Jaroszynski, Dino A.

    2018-04-01

    High-charge electron beams produced by laser-wakefield accelerators are potentially novel, scalable sources of high-power terahertz radiation suitable for applications requiring high-intensity fields. When an intense laser pulse propagates in underdense plasma, it can generate femtosecond duration, self-injected picocoulomb electron bunches that accelerate on-axis to energies from 10s of MeV to several GeV, depending on laser intensity and plasma density. The process leading to the formation of the accelerating structure also generates non-injected, sub-picosecond duration, 1–2 MeV nanocoulomb electron beams emitted obliquely into a hollow cone around the laser propagation axis. These wide-angle beams are stable and depend weakly on laser and plasma parameters. Here we perform simulations to characterise the coherent transition radiation emitted by these beams if passed through a thin metal foil, or directly at the plasma–vacuum interface, showing that coherent terahertz radiation with 10s μJ to mJ-level energy can be produced with an optical to terahertz conversion efficiency up to 10‑4–10‑3.

  14. Finite volume method for radiative heat transfer in an unstructured flow solver for emitting, absorbing and scattering media

    International Nuclear Information System (INIS)

    Gazdallah, Moncef; Feldheim, Véronique; Claramunt, Kilian; Hirsch, Charles

    2012-01-01

    This paper presents the implementation of the finite volume method to solve the radiative transfer equation in a commercial code. The particularity of this work is that the method applied on unstructured hexahedral meshes does not need a pre-processing step establishing a particular marching order to visit all the control volumes. The solver simply visits the faces of the control volumes as numbered in the hexahedral unstructured mesh. A cell centred mesh and a spatial differencing step scheme to relate facial radiative intensities to nodal intensities is used. The developed computer code based on FVM has been integrated in the CFD solver FINE/Open from NUMECA Int. Radiative heat transfer can be evaluated within systems containing uniform, grey, emitting, absorbing and/or isotropically or linear anisotropically scattering medium bounded by diffuse grey walls. This code has been validated for three test cases. The first one is a three dimensional rectangular enclosure filled with emitting, absorbing and anisotropically scattering media. The second is the differentially heated cubic cavity. The third one is the L-shaped enclosure. For these three test cases a good agreement has been observed when temperature and heat fluxes predictions are compared with references taken, from literature.

  15. The cosmic microwave background radiation and the dog in the night

    Science.gov (United States)

    Partridge, R. B.

    The spectrum and angular distribution of the cosmic microwave background radiation (CMBR) are characterized, summarizing the results of recent observations. The emphasis is on null experiments which have established upper limits on anisotropies and spectral distortion. The benefits and pitfalls of null experiments are recalled; the generally observed isotropy of the CMBR and the possible ways anisotropy could be introduced are discussed; and data from searches for anisotropy on arcmin, degree, and arcsec scales are presented in tables and graphs and analyzed in detail. The observed CMBR spectrum is shown to be generally consistent with a black body at temperature 2.75 + or - 0.04 K at wavelengths from 0.1 to 12 cm, although some recent data (Kogut et al., 1988) seem to confirm the presence of distortion due to the Suniaev-Zel'dovich effect at wavelength 3.0 cm.

  16. Magnetic tunnel structures: Transport properties controlled by bias, magnetic field, and microwave and optical radiation

    International Nuclear Information System (INIS)

    Volkov, N.V.; Eremin, E.V.; Tarasov, A.S.; Rautskii, M.V.; Varnakov, S.N.; Ovchinnikov, S.G.; Patrin, G.S.

    2012-01-01

    Different phenomena that give rise to a spin-polarized current in some systems with magnetic tunnel junctions are considered. In a manganite-based magnetic tunnel structure in CIP geometry, the effect of current-channel switching was observed, which causes bias-driven magnetoresistance, rf rectification, and the photoelectric effect. The second system under study, ferromagnetic/insulator/semiconductor, exhibits the features of the transport properties in CIP geometry that are also related to the current-channel switching effect. The described properties can be controlled by a bias, a magnetic field, and optical radiation. At last, the third system under consideration is a cooperative assembly of magnetic tunnel junctions. This system exhibits tunnel magnetoresistance and the magnetic-field-driven microwave detection effect.

  17. Anisotropy of the Cosmic Microwave Background Radiation on Large and Medium Angular Scales

    Science.gov (United States)

    Houghton, Anthony; Timbie, Peter

    1998-01-01

    This grant has supported work at Brown University on measurements of the 2.7 K Cosmic Microwave Background Radiation (CMB). The goal has been to characterize the spatial variations in the temperature of the CMB in order to understand the formation of large-scale structure in the universe. We have concurrently pursued two measurements using millimeter-wave telescopes carried aloft by scientific balloons. Both systems operate over a range of wavelengths, chosen to allow spectral removal of foreground sources such as the atmosphere, Galaxy, etc. The angular resolution of approx. 25 arcminutes is near the angular scale at which the most structure is predicted by current models to be visible in the CMB angular power spectrum. The main goal is to determine the angular scale of this structure; in turn we can infer the density parameter, Omega, for the universe as well as other cosmological parameters, such as the Hubble constant.

  18. Constraints on nonconformal couplings from the properties of the cosmic microwave background radiation.

    Science.gov (United States)

    van de Bruck, Carsten; Morrice, Jack; Vu, Susan

    2013-10-18

    Certain modified gravity theories predict the existence of an additional, nonconformally coupled scalar field. A disformal coupling of the field to the cosmic microwave background (CMB) is shown to affect the evolution of the energy density in the radiation fluid and produces a modification of the distribution function of the CMB, which vanishes if photons and baryons couple in the same way to the scalar. We find the constraints on the couplings to matter and photons coming from the measurement of the CMB temperature evolution and from current upper limits on the μ distortion of the CMB spectrum. We also point out that the measured equation of state of photons differs from w(γ)=1/3 in the presence of disformal couplings.

  19. Hot gas in clusters of galaxies, cosmic microwave background radiation and cosmology

    CERN Multimedia

    CERN. Geneva

    2018-01-01

    Presence of the hot (kTe ~ 3 - 10 KeV) rarefied gas in the clusters of galaxies (most massive gravitationally bound objects in the Universe) leads to the appearance of  "shadows"  in the angular distribution of the Cosmic Microwave Background (CMB) Radiation and permits to measure the peculiar velocities of these clusters relative to the unique coordinate frame where CMB is isotropic. I plan to describe the physics leading to these observational effects. Planck spacecraft, ground based South Pole and Atacama Cosmology Telescopes discovered recently more than two thousand of unknown before Clusters of Galaxies at high redshifts detecting these "shadows" and traces of kinematic effect, demonstrating the correlation of the hot gas velocities with mass concentrations on large scales. Giant ALMA interferometer in Atacama desert resolved recently strong shocks between merging clusters of galaxies. Newly discovered clusters of galaxies permit to study the rate of growth of the large scale structur...

  20. Athermal alterations in the structure in the canalicular membrane and ATPase activity induced by thermal levels of microwave radiation

    International Nuclear Information System (INIS)

    Phelan, A.M.; Neubauer, C.F.; Timm, R.; Neirenberg, J.; Lange, D.G.

    1994-01-01

    Sprague-Dawley rats (200-250 g) were exposed 30 min/day for 4 days to thermogenic levels (rectal temperature increase of 2.2 degrees C) of microwave radiation [2.45 GHz, 80 mW/cm 2 , continuous-wave mode (CW)] or to a radiant heat source resulting in an equivalent increase in body temperature of 2.2 degrees C. On the fifth day the animals were sacrificed and their livers removed. The canalicular membranes were isolated and evaluated for adenosinetriphosphatase (ATPase) activity, total fatty acid composition and membrane fluidity characteristics. Mg ++ -ATPase activity (V max ) decreased by 48.5% in the group exposed to microwave radiation, with no significant change in the group exposed to radiant heat. The decrease in Mg ++ -ATPase was partially compensated by a concomitant increase in Na + /K + -ATPase activity (170% increase in V max over control) in animals exposed to microwave radiation, while no change occurred in the group exposed to radiant heat. This alteration in ATPase activity in the group exposed to microwave radiation is associated with a large decrease in the ratio of saturated to unsaturated fatty acids. Conversely, the group exposed to radiant heat had an increase in the ratio of saturated to unsaturated fatty acids. The most dramatic changes were found in the levels of arachidonic acid. Finally, the electron paramagnetic resonance (EPR) spin label technique used to measure the fluidity of the canalicular membranes of the animals in the three groups (sham, microwave radiation and radiant heat) indicated that the results were different in the three groups, reflecting the changes found in their fatty acid composition. The physiological response to open-quotes equivalentclose quotes thermal loads in rats is expressed differently for different types of energy sources. Possible mechanisms producing these divergent thermogenic responses are discussed. 34 refs., 3 figs., 2 tabs

  1. Volatiles emitted from flowers of gamma-radiated and nonradiated Jasminum polyanthum Franch

    DEFF Research Database (Denmark)

    Christensen, Lars P; Jakobsen, Henrik B; Kristiansen, Kell

    1997-01-01

    Volatile compounds emitted from flowers of Jasminum polyanthum Pepita in situ were collected by dynamic headspace technique and analyzed by GC-FID and GC-MS. A total of 32 compounds were identified. The flower scent was dominated by benzyl acetate (57.8%), p-cresol (12.2%), (E)-isoeugenol (9.7%),...

  2. Microwave Radiometry and Radiometers for Ocean Applications

    DEFF Research Database (Denmark)

    Skou, Niels

    2008-01-01

    The microwave radiometer system measures, within its bandwidth, the naturally emitted radiation – the brightness temperature – of substances within its antenna’s field of view. Thus a radiometer is really a sensitive and calibrated microwave receiver. The radiometer can be a basic total power....../antenna size, and the problem: scanning antenna/space- craft stability. In many cases good compromises have been reached, as evident recalling the many successful missions throughout the recent 30 years. But in some cases the situation calls for special solutions, like the push-broom system or the synthetic...

  3. PRIMORDIAL GRAVITATIONAL WAVES AND RESCATTERED ELECTROMAGNETIC RADIATION IN THE COSMIC MICROWAVE BACKGROUND

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong-Hoon [Basic Science Research Institute, Ewha Womans University, Seoul 03760 (Korea, Republic of); Trippe, Sascha, E-mail: ki13130@gmail.com, E-mail: trippe@astro.snu.ac.kr [Department of Physics and Astronomy, Seoul National University, Seoul 08826 (Korea, Republic of)

    2016-10-20

    Understanding the interaction of primordial gravitational waves (GWs) with the Cosmic Microwave Background (CMB) plasma is important for observational cosmology. In this article, we provide an analysis of an apparently as-yet-overlooked effect. We consider a single free electric charge and suppose that it can be agitated by primordial GWs propagating through the CMB plasma, resulting in periodic, regular motion along particular directions. Light reflected by the charge will be partially polarized, and this will imprint a characteristic pattern on the CMB. We study this effect by considering a simple model in which anisotropic incident electromagnetic (EM) radiation is rescattered by a charge sitting in spacetime perturbed by GWs, and becomes polarized. As the charge is driven to move along particular directions, we calculate its dipole moment to determine the leading-order rescattered EM radiation. The Stokes parameters of the rescattered radiation exhibit a net linear polarization. We investigate how this polarization effect can be schematically represented out of the Stokes parameters. We work out the representations of gradient modes (E-modes) and curl modes (B-modes) to produce polarization maps. Although the polarization effect results from GWs, we find that its representations, the E- and B-modes, do not practically reflect the GW properties such as strain amplitude, frequency, and polarization states.

  4. Detection of hot gas in clusters of galaxies by observation of the microwave background radiation

    International Nuclear Information System (INIS)

    Gull, S.F.; Northover, K.J.E.

    1976-01-01

    It is stated that satellite observations have indicated that many rich clusters are powerful sources of x-rays. This has been interpreted as due to either thermal bremsstrahlung from very hot gas filling the clusters or as inverse Compton scattering of photons by relativistic electrons. Spectral evidence appears to favour a thermal origin for the radiation, implying the existence of large amounts of hot gas. This gas may be a major constituent of the Universe, and independent confirmation of its existence is very important. Observations are here reported of small diminutions in the cosmic microwave background radiation in the direction of several rich clusters of galaxies. This is considered to confirm the existence of large amounts of very hot gas in these clusters and to indicate that the x-radiation is thermal bremsstrahlung and not inverse Compton emission. The observations were made in 1975/1976 using the 25m. telescope at the SRC Appleton Laboratory at a frequency of 10.6 GH2, and details are given of the technique employed. (U.K.)

  5. Radiation protection in occupational exposure to microwave electrotherapy units; Proteccion radiologica en exposicion ocupacional a microondas en unidades de electroterapia

    Energy Technology Data Exchange (ETDEWEB)

    Guardia, V.; Ferrer, S.; Alonso, O.; Almonacid, M.

    2012-07-01

    During the last years, electromagnetic emitters are more and more commonly used for therapeutic treatments in electrotherapy centers. This extended use has caused worries workers, who believe that microwave radiation radiation might have effects similar to those induced by radioactivity, even if the only effects recognised by international regulatory bodies concerning microwave exposure of humans are those of thermal origin. The present study aims to answer the existing concerns about electromagnetic exposure in electrotherapy facilities. After monitoring environmental values in an electrotherapy facility, we conclude that actions must be undertaken in order to reduce the exposure levels, as proposed by the current European guidelines, which should become legally binding for all EU state members within the current year. With the purpose of reducing potential risks of occupational overexposure, we are developing innovative fabrics for microwave shielding. These new materials are able to attenuate 85% of the microwave radiation. As these are light materials, they can be used in all kind of facilities, as wall covers, movable screens or even as personal protection, like lab clothes or gloves. (Author) 6 refs.

  6. Preliminary results on soil-emitted gamma radiation and its relation with the local atmospheric electric field at Amieira (Portugal)

    International Nuclear Information System (INIS)

    Lopes, F; Barbosa, S M; Silva, H G; Bárias, S

    2015-01-01

    The atmospheric electric field near the Earth's surface is dominated by atmospheric pollutants and natural radioactivity, with the latter directly linked to radon ( 222 Rn) gas. For a better comprehension on the temporal variability of both the atmospheric electric field and the radon concentration and its relation with local atmospheric variables, simultaneous measurements of soil-emitted gamma radiation and potential gradient (defined from the vertical component of the atmospheric electric field) were taken every minute, along with local meteorological parameters (e.g., temperature, atmospheric pressure, relative humidity and daily solar radiation). The study region is Amieira, part of the Alqueva lake in Alentejo Portugal, where an interdisciplinary meteorological campaign, ALEX2014, took place from June to August 2014. Soil gamma radiation is more sensitive to small concentrations of radon as compared with alpha particles measurements, for that reason it is more suited for sites with low radon levels, as expected in this case. Preliminary results are presented here: statistical and spectral analysis show that i) the potential gradient has a stronger daily cycle as compared with the gamma radiation, ii) most of the energy of the gamma signal is concentrated in the low frequencies (close to 0), contrary to the potential gradient that has most of the energy in frequency 1 (daily cycle) and iii) a short-term relation between gamma radiation and the potential gradient has not been found. Future work and plans are also discussed. (paper)

  7. Effect of Leaked Radiation from Microwave Oven on Bone Marrow of Male Rats in Pre and Post Pubertal Stage

    Directory of Open Access Journals (Sweden)

    G Jelodar

    2011-01-01

    Full Text Available Introduction: Increasing hematological diseases along with increased use of microwaves in different systems proposed possible correlation between them. Age of exposure to wave is also an important factor. This study was conducted to evaluate the effect of radiation leakaged from microwave oven on hemopoitic bone marrow cells at pre and post pubertal. Methods: Fourteen male mature (2 months old and 14 male immature rats(one month old were randomly divided in to four groups (control and test. Test groups were exposed, three times a day each time 30 min for 60 days, to microwaves produced by microwave oven. After sixty days, animals were sacrified and bone marrow samples were collected from femural bones. Percent of variose cells type and their morphology were evaluated in 500 cells of each smear. Results: exposure to microwave did not exert visible morphological alteration. In the immature experimental group significant decrease in percent of basophilic rubricyte, polychromatic rubricyte, meta rubricyte and all the erythroid cell types observed(P<0.05, whereas, meta myelocyte, notrophilic band, total myeloid cell types and prolifrative cells, other cell types and the myeloid/erythroid ratio significantly increased(P<0.05. In the mature group, however, a significant decrease in percent of meta rubricyte and myelocyte cells observed(P<0.05, although prolifrative cells and all other cell types were significantly increasing in this group. Conclusion: In conclusion, the radiation leaked from microwave oven in the experimental conditions had no effect on the morphology of hemopoitic bone marrow cells, though the number of these cells was altered especially in immature group.

  8. Comparison of Commonly-Used Microwave Radiative Transfer Models for Snow Remote Sensing

    Science.gov (United States)

    Royer, Alain; Roy, Alexandre; Montpetit, Benoit; Saint-Jean-Rondeau, Olivier; Picard, Ghislain; Brucker, Ludovic; Langlois, Alexandre

    2017-01-01

    This paper reviews four commonly-used microwave radiative transfer models that take different electromagnetic approaches to simulate snow brightness temperature (T(sub B)): the Dense Media Radiative Transfer - Multi-Layer model (DMRT-ML), the Dense Media Radiative Transfer - Quasi-Crystalline Approximation Mie scattering of Sticky spheres (DMRT-QMS), the Helsinki University of Technology n-Layers model (HUT-nlayers) and the Microwave Emission Model of Layered Snowpacks (MEMLS). Using the same extensively measured physical snowpack properties, we compared the simulated T(sub B) at 11, 19 and 37 GHz from these four models. The analysis focuses on the impact of using different types of measured snow microstructure metrics in the simulations. In addition to density, snow microstructure is defined for each snow layer by grain optical diameter (Do) and stickiness for DMRT-ML and DMRT-QMS, mean grain geometrical maximum extent (D(sub max)) for HUT n-layers and the exponential correlation length for MEMLS. These metrics were derived from either in-situ measurements of snow specific surface area (SSA) or macrophotos of grain sizes (D(sub max)), assuming non-sticky spheres for the DMRT models. Simulated T(sub B) sensitivity analysis using the same inputs shows relatively consistent T(sub B) behavior as a function of Do and density variations for the vertical polarization (maximum deviation of 18 K and 27 K, respectively), while some divergences appear in simulated variations for the polarization ratio (PR). Comparisons with ground based radiometric measurements show that the simulations based on snow SSA measurements have to be scaled with a model-specific factor of Do in order to minimize the root mean square error (RMSE) between measured and simulated T(sub B). Results using in-situ grain size measurements (SSA or D(sub max), depending on the model) give a mean T(sub B) RMSE (19 and 37 GHz) of the order of 16-26 K, which is similar for all models when the snow

  9. Effect of the Great Attractor on the cosmic microwave background radiation

    Energy Technology Data Exchange (ETDEWEB)

    Bertschinger, E [Massachusetts Inst. of Tech., Cambridge, MA (USA). Dept. of Physics; Gorski, K M [Los Alamos National Lab., NM (USA); Dekel, A [Hebrew Univ., Jerusalem (Israel). Racah Inst. of Physics

    1990-06-07

    ANISOTROPY in the cosmic microwave background radiation (CMB) is expected as a result of fluctuations in gravitational potential caused by large-scale structure in the Universe. The background radiation is redshifted as it climbs out of gravitational wells. Here we present a map of the anisotropy in CMB temperature {Delta}T/T of our region of the Universe as viewed by a distant observer, predicted on the basis of the gravitational potential field. We calculate this field in the vicinity of the Local Group of galaxies from the observed peculiar (non-Hubble) velocities of galaxies, under the assumption that the peculiar motions are induced by gravity. If the cosmological density parameter {Omega} is 1, the gravitational potential field of the Great Attractor and surrounding regions produces a maximum Sachs-Wolfe anisotropy of {Delta}T/T=(1.7{plus minus}0.3) x 10{sup -5} on an angular scale of 1deg. Doppler and adiabatic contributions to this anisotropy are expected to be somewhat larger. If similar fluctuations in the gravitational potential are present elsewhere in the Universe, the anisotropy present when the CMB was last scattered should be visible from the Earth, and should be detectable in current experiments. A fundamental test of whether gravity is responsible for the generation of structure in the Universe can be made by looking for the imprint in the CMB of deep potential wells similar to those found in our neighbourhood, (author).

  10. Interstellar cyanogen and the temperature of the cosmic microwave background radiation

    Science.gov (United States)

    Roth, Katherine C.; Meyer, David M.; Hawkins, Isabel

    1993-01-01

    We present the results of a recently completed effort to determine the amount of CN rotational excitation in five diffuse interstellar clouds for the purpose of accurately measuring the temperature of the cosmic microwave background radiation (CMBR). In addition, we report a new detection of emission from the strongest hyperfine component of the 2.64 mm CN rotational transition (N = 1-0) in the direction toward HD 21483. We have used this result in combination with existing emission measurements toward our other stars to correct for local excitation effects within diffuse clouds which raise the measured CN rotational temperature above that of the CMBR. After making this correction, we find a weighted mean value of T(CMBR) = 2.729 (+0.023, -0.031) K. This temperature is in excellent agreement with the new COBE measurement of 2.726 +/- 0.010 K (Mather et al., 1993). Our result, which samples the CMBR far from the near-Earth environment, attests to the accuracy of the COBE measurement and reaffirms the cosmic nature of this background radiation. From the observed agreement between our CMBR temperature and the COBE result, we conclude that corrections for local CN excitation based on millimeter emission measurements provide an accurate adjustment to the measured rotational excitation.

  11. Self-healing properties of recycled asphalt mixtures containing metal waste: An approach through microwave radiation heating.

    Science.gov (United States)

    González, A; Norambuena-Contreras, J; Storey, L; Schlangen, E

    2018-05-15

    The concept of self-healing asphalt mixtures by bitumen temperature increase has been used by researchers to create an asphalt mixture with crack-healing properties by microwave or induction heating. Metals, normally steel wool fibers (SWF), are added to asphalt mixtures prepared with virgin materials to absorb and conduct thermal energy. Metal shavings, a waste material from the metal industry, could be used to replace SWF. In addition, reclaimed asphalt pavement (RAP) could be added to these mixtures to make a more sustainable road material. This research aimed to evaluate the effect of adding metal shavings and RAP on the properties of asphalt mixtures with crack-healing capabilities by microwave heating. The research indicates that metal shavings have an irregular shape with widths larger than typical SWF used with asphalt self-healing purposes. The general effect of adding metal shavings was an improvement in the crack-healing of asphalt mixtures, while adding RAP to mixtures with metal shavings reduced the healing. The average surface temperature of the asphalt samples after microwave heating was higher than temperatures obtained by induction heating, indicating that shavings are more efficient when mixtures are heated by microwave radiation. CT scan analysis showed that shavings uniformly distribute in the mixture, and the addition of metal shavings increases the air voids. Overall, it is concluded that asphalt mixtures with RAP and waste metal shavings have the potential of being crack-healed by microwave heating. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. The Effect of Microwave Radiation on Prickly Paddy Melon (Cucumis myriocarpus

    Directory of Open Access Journals (Sweden)

    Graham Brodie

    2012-01-01

    Full Text Available The growing list of herbicide-resistant biotypes and environmental concerns about chemical use has prompted interest in alternative methods of managing weeds. This study explored the effect of microwave energy on paddy melon (Cucumis myriocarpus plants, fruits, and seeds. Microwave treatment killed paddy melon plants and seeds. Stem rupture due to internal steam explosions often occurred after the first few seconds of microwave treatment when a small aperture antenna was used to apply the microwave energy. The half lethal microwave energy dose for plants was 145 J/cm2; however, a dose of at least 422 J/cm2 was needed to kill seeds. This study demonstrated that a strategic burst of intense microwave energy, focused onto the stem of the plant is as effective as applying microwave energy to the whole plant, but uses much less energy.

  13. Development of computational pregnant female and fetus models and assessment of radiation dose from positron-emitting tracers

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Tianwu [Geneva University Hospital, Division of Nuclear Medicine and Molecular Imaging, Geneva (Switzerland); Zaidi, Habib [Geneva University Hospital, Division of Nuclear Medicine and Molecular Imaging, Geneva (Switzerland); Geneva University, Geneva Neuroscience Center, Geneva (Switzerland); University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands); University of Southern Denmark, Department of Nuclear Medicine, Odense (Denmark)

    2016-12-15

    Molecular imaging using PET and hybrid (PET/CT and PET/MR) modalities nowadays plays a pivotal role in the clinical setting for diagnosis and staging, treatment response monitoring, and radiation therapy treatment planning of a wide range of oncologic malignancies. The developing embryo/fetus presents a high sensitivity to ionizing radiation. Therefore, estimation of the radiation dose delivered to the embryo/fetus and pregnant patients from PET examinations to assess potential radiation risks is highly praised. We constructed eight embryo/fetus models at various gestation periods with 25 identified tissues according to reference data recommended by the ICRP publication 89 representing the anatomy of the developing embryo/fetus. The developed embryo/fetus models were integrated into realistic anthropomorphic computational phantoms of the pregnant female and used for estimating, using Monte Carlo calculations, S-values of common positron-emitting radionuclides, organ absorbed dose, and effective dose of a number of positron-emitting labeled radiotracers. The absorbed dose is nonuniformly distributed in the fetus. The absorbed dose of the kidney and liver of the 8-week-old fetus are about 47.45 % and 44.76 % higher than the average absorbed dose of the fetal total body for all investigated radiotracers. For {sup 18}F-FDG, the fetal effective doses are 2.90E-02, 3.09E-02, 1.79E-02, 1.59E-02, 1.47E-02, 1.40E-02, 1.37E-02, and 1.27E-02 mSv/MBq at the 8th, 10th, 15th, 20th, 25th, 30th, 35th, and 38th weeks of gestation, respectively. The developed pregnant female/fetus models matching the ICRP reference data can be exploited by dedicated software packages for internal and external dose calculations. The generated S-values will be useful to produce new standardized dose estimates to pregnant patients and embryo/fetus from a variety of positron-emitting labeled radiotracers. (orig.)

  14. Influence of microwave radiation on the post harvest decay and quality of peach fruits in cold storage

    International Nuclear Information System (INIS)

    Azarpajoun, E.; Nikkhah, SH.

    2009-01-01

    This research has been carried out in Khorasan Agricultural and Natural Resources research center to study the effect of microwave radiation on storage time and control of peach fruit rot. Peach cultivars (Alberta, Red, White and Green of Mashad) were harvested in the first and second decades of June, July and September, sorted and stored at 4°C for 12 hours. Then fruits were treated with a Microwave with the Frequency at 2450 MHZ and two intensities, low (200 w) and high (800 w) for 30, 60 and 120 seconds, the treated and control fruits were laid on in plastic trays, packed in perforated polyethylene bags and stored in cold storage (0°C and 90-95% relative humidity) for 2 months. The qualitative tests including fruit rot, total soluble solids, titrable acidity, weight loss, firmness and color were assayed after 15, 30, 45 and 60 days. Sensory attributes were measured after 60 days storage. The experimental design was factorial in frame of completely randomized design. Multiple range test (Duncan) were used to compare the means. The results showed that treating the fruit with microwave decreased the fruit rot and increased pH, flesh firmness and total soluble solids of treated peach. Microwave radiation with the 800w for 60 seconds maintained the qualitative characteristics of fruits. Panel test confirmed these results. (author)

  15. The DMRT-ML Model: Numerical Simulations of the Microwave Emission of Snowpacks Based on the Dense Media Radiative Transfer Theory

    Science.gov (United States)

    Brucker, Ludovic; Picard, Ghislain; Roy, Alexandre; Dupont, Florent; Fily, Michel; Royer, Alain

    2014-01-01

    Microwave radiometer observations have been used to retrieve snow depth and snow water equivalent on both land and sea ice, snow accumulation on ice sheets, melt events, snow temperature, and snow grain size. Modeling the microwave emission from snow and ice physical properties is crucial to improve the quality of these retrievals. It also is crucial to improve our understanding of the radiative transfer processes within the snow cover, and the snow properties most relevant in microwave remote sensing. Our objective is to present a recent microwave emission model and its validation. The model is named DMRT-ML (DMRT Multi-Layer), and is available at http:lgge.osug.frpicarddmrtml.

  16. Influence of radiation-dose pattern from inhaled beta--gamma-emitting radionuclides on canine peripheral lymphocytes

    International Nuclear Information System (INIS)

    Jones, R.K.; Boecker, B.B.; Pickrell, J.A.; Hobbs, C.H.; McClellan, R.O.

    1976-01-01

    As part of studies assess the biological hazards associated with inhaled radionuclides, periodic hematologic evaluations were performed on beagle dogs given a single nose-only exposure to aerosols of beta--gamma-emitting isotopes. The physical form and specific radionuclides selected produced radiation-dose patterns representative of those which might be encountered in the event of human accidental exposures. Dogs received graded lung burdens of either 90 Y, 91 Y, 144 Ce, or 90 Sr, each in fused clay. Differences in the effective half-lives of these radionuclides resulted in a spectrum of cumulative radiation doses to lung delivered at a variety of dose rates. Since the form in which the radionuclides were inhaled was relatively insoluble, the lung and intrathoracic tissues represented the primary recipient of the dose. Regardless of the effective half-life of radionuclide retention, a dose-related depression of peripheral lymphocytes was observed at various times after inhalation exposure. The time at which maximum depression and subsequent recovery occurred, however, was most directly related to the effective half-life of the radionuclide. Of special interest was the persistence of lymphopenia through 2 1 / 2 years after exposure to 144 Ce and 90 Sr in fused clay where, other than tracheobronchial lymph nodes, the lymphoid tissue received very little radiation dose. The possible mechanisms responsible for lymphocyte depression from these various radiation-dose patterns are discussed

  17. HARD X-RAY AND MICROWAVE EMISSIONS FROM SOLAR FLARES WITH HARD SPECTRAL INDICES

    Energy Technology Data Exchange (ETDEWEB)

    Kawate, T. [Kwasan and Hida Observatory, Kitashirakawa-oiwakecho, Sakyo, Kyoto 606-8502 (Japan); Nishizuka, N. [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 229-8510 (Japan); Oi, A. [College of Science, Ibaraki University, Mito, Ibaraki 310-8512 (Japan); Ohyama, M. [Faculty of Education, Shiga University, 2-5-1 Hiratsu, Otsu, Shiga 1-1, Baba Hikone city, Siga 522-8522 (Japan); Nakajima, H., E-mail: kawate@kusastro.kyoto-u.ac.jp [Nobeyama Solar Radio Observatory, NAOJ, Nobeyama, Minamisaku, Nagano 384-1305 (Japan)

    2012-03-10

    We analyze 10 flare events that radiate intense hard X-ray (HXR) emission with significant photons over 300 keV to verify that the electrons that have a common origin of acceleration mechanism and energy power-law distribution with solar flares emit HXRs and microwaves. Most of these events have the following characteristics. HXRs emanate from the footpoints of flare loops, while microwaves emanate from the tops of flare loops. The time profiles of the microwave emission show delays of peak with respect to those of the corresponding HXR emission. The spectral indices of microwave emissions show gradual hardening in all events, while the spectral indices of the corresponding HXR emissions are roughly constant in most of the events, though rather rapid hardening is simultaneously observed in some for both indices during the onset time and the peak time. These characteristics suggest that the microwave emission emanates from the trapped electrons. Then, taking into account the role of the trapping of electrons for the microwave emission, we compare the observed microwave spectra with the model spectra calculated by a gyrosynchrotron code. As a result, we successfully reproduce the eight microwave spectra. From this result, we conclude that the electrons that have a common acceleration and a common energy distribution with solar flares emit both HXR and microwave emissions in the eight events, though microwave emission is contributed to by electrons with much higher energy than HXR emission.

  18. A measurement of the low frequency spectrum of the cosmic microwave background radiation

    International Nuclear Information System (INIS)

    Levin, S.M.

    1987-04-01

    As part of a larger effort to measure the spectrum of the Cosmic Background Radiation (CBR) at low frequencies, the intensity of the CBR has been measured at a frequency of 1.410 GHz. The measurement was made by comparing the power received from the sky with the power received from a specially designed cooled calibration target with known properties. Sources of radiation other than the CBR were then identified and subtracted to calculate the antenna temperature of the CBR at 1.410 GHz. The instrument used to measure the CBR was a total-power microwave radiometer with a 25 MHz bandwidth centered at 1.410 GHz. The radiometer had a noise temperature of 80 K, and sufficient data were taken that radiometer noise did not contribute significantly to the total measurement error. The sources of error were predominantly systematic in nature, and the largest error was due to uncertainty in the reflection characteristics of the cold-load calibrator. Identification and subtraction of signals from the Galaxy (0.7 K) and the Earth's atmosphere (0.8 K) were also significant parts of the data reduction and error analysis. The brightness temperature of the Cosmic Background Radiation at 1.410 GHz is 222. +- 0.55 Kelvin. The spectrum of the CBR, as determined by this measurement and other published results, is consistent with a blackbody spectrum of temperature 2.741 +- 0.016. Constraints on the amount by which the CBR spectrum deviates from Planck spectrum are used to place limits on energy releases early in the history of the universe. 55 refs., 25 figs., 8 tabs

  19. A map of the cosmic microwave background radiation from the Wilkinson Microwave Anisotropy Probe (WMAP), showing the large-scale fluctuations (the quadrupole and octopole) isolated by an analysis done partly by theorists at CERN.

    CERN Multimedia

    2004-01-01

    A recent analysis, in part by theorists working at CERN, suggests a new view of the cosmic microwave background radiation. It seems the solar system, rather than the universe, causes the radiation's large-scale fluctuations, similar to the bass in a song.

  20. Overview of a benefit/risk ratio optimized for a radiation emitting device used in non-destructive testing

    Energy Technology Data Exchange (ETDEWEB)

    Maharaj, H.P., E-mail: H_P_Maharaj@hc-sc.gc.ca [Health Canada, Dept. of Health, Consumer and Clinical Radiaton Protection Bureau, Ottawa, Ontario (Canada)

    2016-03-15

    This paper aims to provide an overview of an optimized benefit/risk ratio for a radiation emitting device. The device, which is portable, hand-held, and open-beam x-ray tube based, is utilized by a wide variety of industries for purposes of determining elemental or chemical analyses of materials in-situ based on fluorescent x-rays. These analyses do not cause damage or permanent alteration of the test materials and are considered a non-destructive test (NDT). Briefly, the key characteristics, principles of use and radiation hazards associated with the Hay device are presented and discussed. In view of the potential radiation risks, a long term strategy that incorporates risk factors and guiding principles intended to mitigate the radiation risks to the end user was considered and applied. Consequently, an operator certification program was developed on the basis of an International Standards Organization (ISO) standard (ISO 20807:2004) and in collaboration with various stake holders and was implemented by a federal national NDT certification body several years ago. It comprises a written radiation safety examination and hands-on training with the x-ray device. The operator certification program was recently revised and the changes appear beneficial. There is a fivefold increase in operator certification (Levels 1 a nd 2) to date compared with earlier years. Results are favorable and promising. An operational guidance document is available to help mitigate radiation risks. Operator certification in conjunction with the use of the operational guidance document is prudent, and is recommended for end users of the x-ray device. Manufacturers and owners of the x-ray devices will also benefit from the operational guidance document. (author)

  1. Overview of a benefit/risk ratio optimized for a radiation emitting device used in non-destructive testing

    International Nuclear Information System (INIS)

    Maharaj, H.P.

    2016-01-01

    This paper aims to provide an overview of an optimized benefit/risk ratio for a radiation emitting device. The device, which is portable, hand-held, and open-beam x-ray tube based, is utilized by a wide variety of industries for purposes of determining elemental or chemical analyses of materials in-situ based on fluorescent x-rays. These analyses do not cause damage or permanent alteration of the test materials and are considered a non-destructive test (NDT). Briefly, the key characteristics, principles of use and radiation hazards associated with the Hay device are presented and discussed. In view of the potential radiation risks, a long term strategy that incorporates risk factors and guiding principles intended to mitigate the radiation risks to the end user was considered and applied. Consequently, an operator certification program was developed on the basis of an International Standards Organization (ISO) standard (ISO 20807:2004) and in collaboration with various stake holders and was implemented by a federal national NDT certification body several years ago. It comprises a written radiation safety examination and hands-on training with the x-ray device. The operator certification program was recently revised and the changes appear beneficial. There is a fivefold increase in operator certification (Levels 1 a nd 2) to date compared with earlier years. Results are favorable and promising. An operational guidance document is available to help mitigate radiation risks. Operator certification in conjunction with the use of the operational guidance document is prudent, and is recommended for end users of the x-ray device. Manufacturers and owners of the x-ray devices will also benefit from the operational guidance document. (author)

  2. Plasma relativistic microwave electronics

    International Nuclear Information System (INIS)

    Kuzelev, M.V.; Loza, O.T.; Rukhadze, A.A.; Strelkov, P.S.; Shkvarunets, A.G.

    2001-01-01

    One formulated the principles of plasma relativistic microwave electronics based on the induced Cherenkov radiation of electromagnetic waves at interaction of a relativistic electron beam with plasma. One developed the theory of plasma relativistic generators and accelerators of microwave radiation, designed and studied the prototypes of such devices. One studied theoretically the mechanisms of radiation, calculated the efficiencies and the frequency spectra of plasma relativistic microwave generators and accelerators. The theory findings are proved by the experiment: intensity of the designed sources of microwave radiation is equal to 500 μW, the frequency of microwave radiation is increased by 7 times (from 4 up to 28 GHz), the width of radiation frequency band may vary from several up to 100%. The designed sources of microwave radiation are no else compared in the electronics [ru

  3. Comparison of 864 and 935 MHz microwave radiation effects on cell culture

    International Nuclear Information System (INIS)

    Pavicic, I.; Trosic, I.; Sarolic, A.

    2005-01-01

    The aim of our study was to evaluate and compare the effect of 864 and 935 MHz microwave radiation on proliferation, colony forming and viability of Chinese hamster lung cells, cell line V79. Cell cultures were exposed both to the 864 MHz microwave field in transversal electromagnetic mode cell (TEM-cell) and to the 935 MHz field in Gigahertz transversal electromagnetic mode cell (GTEM-cell) for 1, 2 and 3 hours. Philips PM 5508 generator connected with a signal amplifier generated the frequency of 864 MHz, whereas Hewlett Packard HP8657A signal generator was used to generate the frequency of 935 MHz. The average specific absorption rate (SAR) was 0.08 W/kg for 864 MHz and 0.12 W/kg for 935 MHz. To determine the cell growth, V79 cells were plated in the concentration of 1x10 4 cells per milliliter of nutrient medium. Cells were cultured in a humidified atmosphere at 37 degrees of C in 5% CO 2 . Cell proliferation was determined by cell counts for each hour of exposure during the five post-exposure days. To identify colony-forming ability, cells were cultivated in the concentration of 40 cells/mL of medium and incubated as described above. Colony-forming ability was assessed for each exposure time by colony count on post-exposure day 7. Trypan blue exclusion test was used to determine cell viability. On post-exposure day 3, the growth curve of 864 MHz irradiated cells showed a significant decrease (p less than 0.05) after 2 and 3 hours of exposure in comparison with control cells. Cells exposed to 935 MHz radiation showed a significant decrease (p less than 0.05) after 3 hours of exposure on post-exposure day 3. Both the colony-forming ability and viability of 864 MHz and 935 MHz exposed cells did not significantly differ from matched control cells. In conclusion, both applied RF/MW fields have shown similar effects on cell culture growth, colony forming and cell viability of the V79 cell line.(author)

  4. Generation of tunable narrow-band surface-emitted terahertz radiation in periodically poled lithium niobate.

    Science.gov (United States)

    Weiss, C; Torosyan, G; Avetisyan, Y; Beigang, R

    2001-04-15

    Generation of tunable narrow-band terahertz (THz) radiation perpendicular to the surface of periodically poled lithium niobate by optical rectification of femtosecond pulses is reported. The generated THz radiation can be tuned by use of different poling periods and different observation angles, limited only by the available bandwidth of the pump pulse. Typical bandwidths were 50-100 GHz, depending on the collection angle and the number of periods involved.

  5. The cosmic microwave background radiation power spectrum as a random bit generator for symmetric- and asymmetric-key cryptography.

    Science.gov (United States)

    Lee, Jeffrey S; Cleaver, Gerald B

    2017-10-01

    In this note, the Cosmic Microwave Background (CMB) Radiation is shown to be capable of functioning as a Random Bit Generator, and constitutes an effectively infinite supply of truly random one-time pad values of arbitrary length. It is further argued that the CMB power spectrum potentially conforms to the FIPS 140-2 standard. Additionally, its applicability to the generation of a (n × n) random key matrix for a Vernam cipher is established.

  6. Radiation characteristics of a coaxial waveguide with eccentric inner conductor for application in hyperthermia and microwave reflex therapy

    Directory of Open Access Journals (Sweden)

    R. Herschmann

    2007-06-01

    Full Text Available This paper examines the radiation characteristics of a contact emitter conceived for application in hyperthermia and microwave reflex therapy. It is important to analyse the distribution of power density in the near field area, as the radiator's therapeutic sphere of activity is localized here. The contact emitter is a coaxial radiator with an eccentric course of the inner conductor. According to Huygens principle, a theoretical view of the near field radiation characteristics is made by determining the equivalent current densities in the emitter aperture. It is shown that by an eccentric shift of the inner conductor, an almost isotropic near field radiation pattern and power density can be achieved. For this, the electromagnetic field in the emitter aperture is determined by using a Bipolar coordinate system. This calculation considers only the fundamental TEM mode of the contact emitter. Besides the theoretical results near and far fields are simulated using the programme system Ansoft HFSS.

  7. Monte Carlo simulation of radiative transfer in scattering, emitting, absorbing slab with gradient index

    International Nuclear Information System (INIS)

    Huang Yong; Liang Xingang; Xia Xinlin

    2005-01-01

    The Monte Carlo method is used to simulate the thermal emission of absorbing-emitting-scattering slab with gradient index. Three Monte Carlo ray-tracing strategies are considered. The first strategy is keeping the real distribution of the refractive index and to trace bundles in a curve route. The second strategy is discretizing the slab into sub-layers, each having constant refractive index. The bundle is traced in a straight route in each sub-layer and the reflection at the inner interface is taken into account. The third strategy is similar to the second one but only the total reflection at the inner interface is computed. Little difference is observed among the results of apparent thermal emission by these three different Monte Carlo ray tracing strategies. The results also show that the apparent hemispherical emissivity non-monotonously varies with increasing optical thickness of the slab with strong scattering gradient index. Many parameters can influence the apparent thermal emission greatly

  8. Reprint of 'Evaluation of Scattered Radiation Emitted From X-ray Security Scanners on Occupational Dose to Airport Personnel'

    Science.gov (United States)

    Dalah, Entesar; Fakhry, Angham; Mukhtar, Asma; Al Salti, Farah; Bader, May; Khouri, Sara; Al-Zahmi, Reem

    2017-11-01

    Based on security issues and regulations airports are provided with luggage cargo scanners. These scanners utilize ionizing radiation that in principle present health risks toward humans. The study aims to investigate the amount of backscatter produced by passenger luggage and cargo toward airport personnel who are located at different distances from the scanners. To approach our investigation a Thermo Electron Radeye-G probe was used to quantify the backscattered radiation measured in terms of dose-rate emitted from airport scanners, Measurements were taken at the entrance and exit positions of the X-ray tunnel at three different distances (0, 50, and 100 cm) for two different scanners; both scanners include shielding curtains that reduce scattered radiation. Correlation was demonstrated using the Pearson coefficient test. Measurements confirmed an inverse relationship between dose rate and distance. An estimated occupational accumulative dose of 0.88 mSv/y, and 2.04 mSv/y were obtained for personnel working in inspection of carry-on, and cargo, respectively. Findings confirm that the projected dose of security and engineering staff are being well within dose limits.

  9. Electromagnetic radiation emitted by a plasma produced in air by laser pulses with lambda = 10.6 μm

    International Nuclear Information System (INIS)

    Danilychev, V.A.; Zvorykin, V.D.; Kholin, I.V.; Chugunov, A.Y.

    1981-01-01

    The spectrum, brightness, and energy have been measured for the electromagnetic radiation emitted by a plasma produced in air near a solid surface by pulses from a high-power CO 2 laser. The air pressure was varied over the range p 0 = 0.1--760 torr, and the laser power density was varied over the range q = 5 x 10 6 --10 8 W/cm 2 . At p 0 > or approx. =2--5 torr the radiation properties of the plasma are determined by a laser-beam absorption wave which arises in the gas. The maximum brightness temperature, T/sub b/approx. =50 000 K (lambda = 400 +- 20 nm), is reached at p 0 = 25 torr. The emission spectrum is quite different from an equilibrium spectrum, consisting primarily of NII, OII, and NIII lines. The total energy radiation by the plasma in the wavelength interval 360--2600 nm into a solid angle of 4π sr reaches 2.3% of the laser pulse energy

  10. Palliative treatment with radiation-emitting metallic stents in unresectable Bismuth type III or IV hilar cholangiocarcinoma.

    Science.gov (United States)

    Lu, Jian; Guo, Jin-He; Zhu, Hai-Dong; Zhu, Guang-Yu; Wang, Yong; Zhang, Qi; Chen, Li; Wang, Chao; Pan, Tian-Fan; Teng, Gao-Jun

    2017-01-01

    The emerging data for stenting in combination with brachytherapy in unresectable hilar cholangiocarcinoma are encouraging. The aim of this study was to evaluate the efficacy and safety of radiation-emitting metallic stents (REMS) for unresectable Bismuth type III or IV hilar cholangiocarcinoma. Consecutive patients who underwent percutaneous placement with REMS or uncovered self-expandable metallic stent (SEMS) for unresectable Bismuth type III or IV hilar cholangiocarcinoma between September 2011 and April 2016 were identified into this retrospective study. Data on patient demographics and overall survival, functional success, stent patency and complications were collected at the authors' hospital. A total of 59 patients were included: 33 (55.9%) in the REMS group and 26 (44.1%) in the SEMS group. The median overall survival was 338 days in the REMS group and 141 days in the SEMS group (philar cholangiocarcinoma, and seems to prolong survival as well as patency of stent in these patients.

  11. Note: Real time optical sensing of alpha-radiation emitting radioactive aerosols based on solid state nuclear track detector

    International Nuclear Information System (INIS)

    Kulkarni, A.; Bak, M. S.; Ha, S.; Joshirao, P.; Manchanda, V.; Kim, T.

    2015-01-01

    A sensitive radioactive aerosols sensor has been designed and developed. Its design guidance is based on the need for a low operational cost and reliable measurements to provide daily aerosol monitoring. The exposure of diethylene-glycol bis (allylcarbonate) to radiation causes modification of its physico-chemical properties like surface roughness and reflectance. In the present study, optical sensor based on the reflectance measurement has been developed with an aim to monitor real time presence of alpha radioactive aerosols emitted from thorium nitrate hydrate. The results shows that the fabricated sensor can detect 0.0157 kBq to 0.1572 kBq of radio activity by radioactive aerosols generated from (Th(NO 3 ) 4 ⋅ 5H 2 O) at 0.1 ml/min flow rate. The proposed instrument will be helpful to monitor radioactive aerosols in/around a nuclear facility, building construction sites, mines, and granite polishing factories

  12. Note: Real time optical sensing of alpha-radiation emitting radioactive aerosols based on solid state nuclear track detector

    Science.gov (United States)

    Kulkarni, A.; Ha, S.; Joshirao, P.; Manchanda, V.; Bak, M. S.; Kim, T.

    2015-06-01

    A sensitive radioactive aerosols sensor has been designed and developed. Its design guidance is based on the need for a low operational cost and reliable measurements to provide daily aerosol monitoring. The exposure of diethylene-glycol bis (allylcarbonate) to radiation causes modification of its physico-chemical properties like surface roughness and reflectance. In the present study, optical sensor based on the reflectance measurement has been developed with an aim to monitor real time presence of alpha radioactive aerosols emitted from thorium nitrate hydrate. The results shows that the fabricated sensor can detect 0.0157 kBq to 0.1572 kBq of radio activity by radioactive aerosols generated from (Th(NO3)4 ṡ 5H2O) at 0.1 ml/min flow rate. The proposed instrument will be helpful to monitor radioactive aerosols in/around a nuclear facility, building construction sites, mines, and granite polishing factories.

  13. Note: Real time optical sensing of alpha-radiation emitting radioactive aerosols based on solid state nuclear track detector

    Energy Technology Data Exchange (ETDEWEB)

    Kulkarni, A.; Bak, M. S., E-mail: tkim@skku.edu, E-mail: moonsoo@skku.edu [School of Mechanical Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Ha, S. [SKKU Advanced Institute of Nano Technology (SAINT), Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Joshirao, P.; Manchanda, V. [Department of Energy Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Kim, T., E-mail: tkim@skku.edu, E-mail: moonsoo@skku.edu [School of Mechanical Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); SKKU Advanced Institute of Nano Technology (SAINT), Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2015-06-15

    A sensitive radioactive aerosols sensor has been designed and developed. Its design guidance is based on the need for a low operational cost and reliable measurements to provide daily aerosol monitoring. The exposure of diethylene-glycol bis (allylcarbonate) to radiation causes modification of its physico-chemical properties like surface roughness and reflectance. In the present study, optical sensor based on the reflectance measurement has been developed with an aim to monitor real time presence of alpha radioactive aerosols emitted from thorium nitrate hydrate. The results shows that the fabricated sensor can detect 0.0157 kBq to 0.1572 kBq of radio activity by radioactive aerosols generated from (Th(NO{sub 3}){sub 4} ⋅ 5H{sub 2}O) at 0.1 ml/min flow rate. The proposed instrument will be helpful to monitor radioactive aerosols in/around a nuclear facility, building construction sites, mines, and granite polishing factories.

  14. Biodegradable, pH-sensitive chitosan beads obtained under microwave radiation for advanced cell culture.

    Science.gov (United States)

    Piątkowski, Marek; Janus, Łukasz; Radwan-Pragłowska, Julia; Bogdał, Dariusz; Matysek, Dalibor

    2018-04-01

    A new type of promising chitosan beads with advanced properties were obtained under microwave radiation according to Green Chemistry principles. Biomaterials were prepared using chitosan as raw material and glutamic acid/1,5-pentanodiol mixture as crosslinking agents. Additionally beads were modified with Tilia platyphyllos extract to enhance their antioxidant properties. Beads were investigated over their chemical structure by FT-IR analysis. Also their morphology has been investigated by SEM method. Additionally swelling capacity of the obtained hydrogels was determined. Lack of cytotoxicity has been confirmed by MTT assay. Proliferation studies were carried out on L929 mouse fibroblasts. Advanced properties of the obtained beads were investigated by studying pH sensitivity and antioxidant properties by DPPH method. Also susceptibility to degradation and biodegradation by Sturm Test method was evaluated. Results shows that proposed chitosan beads and their eco-friendly synthesis method can be applied in cell therapy and tissue engineering. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. A measurement of the medium-scale anisotropy in the cosmic microwave background radiation

    Science.gov (United States)

    Cheng, E. S.; Cottingham, D. A.; Fixsen, D. J.; Inman, C. A.; Kowitt, M. S.; Meyer, S. S.; Page, L. A.; Puchalla, J. L.; Silverberg, R. F.

    1994-01-01

    Observations from the first flight of the Medium Scale Anisotropy Measurement (MSAM) are analyzed to place limits on Gaussian fluctuations in the cosmic microwave background radiation (CMBR). This instrument chops a 30 min beam in a three-position pattern with a throw of +/- 40 min; the resulting data is analyzed in statistically independent single- and double-difference sets. We observe in four spectral channels at 5.6, 9.0, 16.5, and 22.5/cm, allowing the separation of interstellar dust emission from CMBR fluctuations. The dust component is correlated with the IRAS 100 micron map. The CMBR component has two regions where the signature of an unresolved source is seen. Rejecting these two source regions, we obtain a detection of fluctuations which match CMBR in our spectral bands of 0.6 x 10(exp -5) is less than Delta (T)/T is less than 2.2 x 10(exp -5) (90% CL interval) for total rms Gaussian fluctuations with correlation angle 0.5 deg, using the single-difference demodulation. Fore the double difference demodulation, the result is 1.1 x 10(exp -5) is less than Delta(T)/T is less than 3.1 x 10(exp -5) (90% CL interval) at a correlation angle of 0.3 deg.

  16. An Analysis of Recent Measurements of the Temperature of the Cosmic Microwave Background Radiation

    Science.gov (United States)

    Smoot, G.; Levin, S. M.; Witebsky, C.; De Amici, G.; Rephaeli, Y.

    1987-07-01

    This paper presents an analysis of the results of recent temperature measurements of the cosmic microwave background radiation (CMBR). The observations for wavelengths longer than 0.1 cum are well fit by a blackbody spectrum at 2.74{+ or -}0.0w K; however, including the new data of Matsumoto et al. (1987) the result is no longer consistent with a Planckian spectrum. The data are described by a Thomson-distortion parameter u=0.021{+ or -}0.002 and temperature 2.823{+ or -}0.010 K at the 68% confidence level. Fitting the low-frequency data to a Bose-Einstein spectral distortion yields a 95% confidence level upper limit of 1.4 x 10{sup -2} on the chemical potential mu{sub 0}. These limits on spectral distortions place restrictions on a number of potentially interesting sources of energy release to the CMBR, including the hot intergalactic medium proposed as the source of the X-ray background.

  17. Optimal width of quasicrystalline slabs of dielectric cylinders to microwave radiation transmission contrast

    Energy Technology Data Exchange (ETDEWEB)

    Andueza, Ángel; Sevilla, Joaquín [Dpto. Ing. Eléctrica y Electrónica Universidad Pública de Navarra, 31006 Pamplona (Spain); Smart Cities Institute, Universidad Pública de Navarra, 31006 Pamplona (Spain); Wang, Kang [Laboratoire de Physique des Solides, UMR CNRS/Université Paris-Sud, Université Paris-Saclay, 91405 Orsay (France); Pérez-Conde, Jesús [Dpto. de Física Universidad Pública de Navarra, 31006 Pamplona (Spain)

    2016-08-28

    Light confinement induced by resonant states in aperiodic photonic structures is interesting for many applications. A particular case of these resonances can be found in 2D quasicrystalline arrangements of dielectric cylinders. These systems present a rather isotropic band gap as well as isolated in-gap photonic states (as a result of spatially localized resonances). These states are built by high symmetry polygonal clusters that can be regarded as photonic molecules. In this paper, we study the transmission properties of a slab of glass cylinders arranged in approximants of the decagonal quasicrystalline structure. In particular, we investigate the influence of the slab width in the transmission contrast between the states and the gap. The study is both experimental and numerical in the microwave regime. We find that the best transmission contrast is found for a width of around three times the radiation wavelength. The transmission in the band gap region is mediated by the resonances of the photonic molecules. If the samples are thin enough, they become transparent except around a resonance of the photonic molecule which reflects the incoming light.

  18. A limit of the anisotropy of the microwave background radiation on arc minute scales

    International Nuclear Information System (INIS)

    Readhead, A.C.S.; Lawrence, C.R.; Myers, S.T.; Sargent, W.L.W.; Hardebeck, H.E.

    1989-01-01

    After adjustment for observational parameters, various models predict an upper anisotropy limit of microwave background radiation of delta T/T less than 0.00017 at the 95 percent confidence level for uncorrelated patches of sky that are uniform on a 2-arcsec scale. This limit is more than a factor of 2 lower than previous limits on comparable angular scales. Results obtained assuming Gaussian fluctuations place useful constraints on models of galaxy formation based on adiabatic or isocurvature fluctuations in baryonic matter, provided that any reionization of the intergalactic medium occurred at z less than 40. Adiabatic models are ruled out with greater than 95 percent confidence, and isocurvature models with Omega less than 0.8 are inconsistent with the measured limits. Nonbaryonic models with early reionization predict anisotropy levels up to a factor of 3 below the present limit. The lowest predictions come from models with biased galaxy formation, nonbaryonic matter, and early reionization and are as much as a factor of 10 below the present sensitivity limit. The predictions of most popular contending theories of galaxy formation are within reach of the techniques used in this study. 112 refs

  19. The relationship between cellular adhesion and surface roughness in polystyrene modified by microwave plasma radiation

    Directory of Open Access Journals (Sweden)

    Biazar E

    2011-03-01

    Full Text Available Esmaeil Biazar1, Majid Heidari2, Azadeh Asefnezhad2, Naser Montazeri11Department of Chemistry, Islamic Azad University, Tonekabon Branch, Mazandaran; 2Department of Biomaterial Engineering, Faculty of Biomedical Engineering, Science and Research Branch, Islamic Azad University, Tehran, IranBackground: Surface modification of medical polymers can improve biocompatibility. Pure polystyrene is hydrophobic and cannot provide a suitable environment for cell cultures. The conventional method for surface modification of polystyrene is treatment with plasma. In this study, conventional polystyrene was exposed to microwave plasma treatment with oxygen and argon gases for 30, 60, and 180 seconds.Methods and results: Attenuated total reflection Fourier transform infrared spectra investigations of irradiated samples indicated clearly the presence of functional groups. Atomic force microscopic images of samples irradiated with inert and active gases indicated nanometric surface topography. Samples irradiated with oxygen plasma showed more roughness (31 nm compared with those irradiated with inert plasma (16 nm at 180 seconds. Surface roughness increased with increasing duration of exposure, which could be due to reduction of the contact angle of samples irradiated with oxygen plasma. Contact angle analysis showed reduction in samples irradiated with inert plasma. Samples irradiated with oxygen plasma showed a lower contact angle compared with those irradiated by argon plasma.Conclusion: Cellular investigations with unrestricted somatic stem cells showed better adhesion, cell growth, and proliferation for samples radiated by oxygen plasma with increasing duration of exposure than those of normal samples.Keywords: surface topography, polystyrene, plasma treatment, argon, oxygen

  20. Instrumentation measurement and testing complex for detection and identification of radioactive materials using the emitted radiation

    International Nuclear Information System (INIS)

    Samossadny, V.T.; Dmitrenko, V.V.; Kadlin, V.V.; Kolesnikov, S.V.; Ulin, S.E.; Grachev, V.M.; Vlasik, K.F.; Dedenko, G.L.; Novikov, D.V.; Uteshev, Z.M.

    2006-01-01

    Simultaneous measurement of neutron and gamma radiation is a very usefull method for effective nuclear materials identification and control. The gamma-ray-neutron complex described in the paper is based on two multi-layer 3 He neutrons detectors and two High Pressure Xenon gamma-ray spectrometers assembled in one unit. All these detectors were callibrated on neutron and gamma-ray sources. The main characteristics of the instrumentation , its testing results and gamma-ray and neutron radiation parameters, which have been measured are represented in the paper. The gamma-neutron sources and fissile materials reliable detection and identification capability was demonstrated

  1. A Numerical Simulation for Prediction of Infrared Radiation Emitted from Plain Surfaces with Different Geometries

    Directory of Open Access Journals (Sweden)

    Vakilabadi K.A.

    2017-08-01

    Full Text Available In this paper, infrared radiation exiting plain surfaces with different geometries is numerically simulated. Surfaces under consideration are assumed to have steady uniform heat generation inside. Moreover, the boundaries of the surfaces are considered to be at the surroundings temperature. Infrared radiation is calculated based on the temperature profile determined for the surface. The temperature profile of the surface is determined assuming the two dimensional heat conduction equations to govern the problem. The physical domain is transformed into the appropriate computational domain and the governing equation is mapped into the suitable forms in the new coordinate system of variables. After that the temperature profile of the surface is computed, the infrared radiation distribution of the surface is evaluated based on the equations given in the manuscript. The temperature profile as well as the IR images are given in the results section. It is concluded that the maximum value of infrared radiation of the surface occurs at the center. Moreover, it is concluded that among surfaces with equal areas, the one having the largest perimeter has the least value of IR at its center.

  2. Contribution to the theoretical study of a high power microwave radiation produced by a relativistic electron beam

    International Nuclear Information System (INIS)

    Sellem, F.

    1997-01-01

    This thesis is dedicated to the study of microwave radiation produced by relativistic electron beams. The vircator (virtual cathode oscillator) is a powerful microwave source based on this principle. This device is described but the complexity of the physical processes involved makes computer simulation necessary before proposing a simplified model. The existent M2V code has been useful to simulate the behaviour of a vircator but the representation of some phenomena such as hot points, the interaction of waves with particles lacks reliability. A new code CODEX has been written, it can solve Maxwell equations on a double mesh system by a finite difference method. The electric and magnetic fields are directly computed from the scalar and vectorial potentials. This new code has been satisfactorily tested on 3 configurations: the bursting of an electron beam in vacuum, the evolution of electromagnetic fields in diode and the propagation of waves in a wave tube. CODEX has been able to simulate the behaviour of a vircator, the frequency and power are well predicted and some contributions to the problem of origin of microwave production have been made. It seems that the virtual cathode is not directly involved in the microwave production. (A.C.)

  3. Highly biocompatible, nanocrystalline hydroxyapatite synthesized in a solvothermal process driven by high energy density microwave radiation

    Science.gov (United States)

    Smolen, Dariusz; Chudoba, Tadeusz; Malka, Iwona; Kedzierska, Aleksandra; Lojkowski, Witold; Swieszkowski, Wojciech; Kurzydlowski, Krzysztof Jan; Kolodziejczyk-Mierzynska, Małgorzata; Lewandowska-Szumiel, Małgorzata

    2013-01-01

    A microwave, solvothermal synthesis of highly biocompatible hydroxyapatite (HAp) nanopowder was developed. The process was conducted in a microwave radiation field having a high energy density of 5 W/mL and over a time less than 2 minutes. The sample measurements included: powder X-ray diffraction, density, specific surface area, and chemical composition. The morphology and structure were investigated by scanning electron microscopy as well as transmission electron microscopy (TEM). The thermal behavior analysis was conducted using a simultaneous thermal analysis technique coupled with quadruple mass spectrometry. Additionally, Fourier transform infrared spectroscopy tests of heated samples were performed. A degradation test and a biocompatibility study in vitro using human osteoblast cells were also conducted. The developed method enables the synthesis of pure, fully crystalline hexagonal HAp nanopowder with a specific surface area close to 240 m2/g and a Ca/P molar ratio equal to 1.57. TEM measurements showed that this method results in particles with an average grain size below 6 nm. A 28-day degradation test conducted according to the ISO standard indicated a 22% loss of initial weight and a calcium ion concentration at 200 μmol/dm3 in the tris(hydroxymethyl)aminomethane hydrochloride test solution. The cytocompatibility of the obtained material was confirmed in a culture of human bone derived cells, both in an indirect test using the material extract, and in direct contact. A quantitative analysis was based on the 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide. Viability assay as well as on DNA content measurements in the PicoGreen test. Indirect observations were performed at one point in time according to the ISO standard for in vitro cytotoxicity (ie, after 24 hours of cell exposure to the extracts). The direct contact tests were completed at three time points: after 24 hours, on day 7, and on day 14 of a culture in an osteogenic

  4. Highly biocompatible, nanocrystalline hydroxyapatite synthesized in a solvothermal process driven by high energy density microwave radiation

    Directory of Open Access Journals (Sweden)

    Smolen D

    2013-02-01

    Full Text Available Dariusz Smolen1, Tadeusz Chudoba1, Iwona Malka1, Aleksandra Kedzierska1, Witold Lojkowski1, Wojciech Swieszkowski2, Krzysztof Jan Kurzydlowski2, Malgorzata Kolodziejczyk-Mierzynska3, Malgorzata Lewandowska-Szumiel31Polish Academy of Science, Institute of High Pressure Physics, Warsaw, Poland; 2Faculty of Materials Engineering, Warsaw University of Technology, Warsaw, Poland; 3Department of Histology and Embryology, Center of Biostructure Research, Medical University of Warsaw, Warsaw, PolandAbstract: A microwave, solvothermal synthesis of highly biocompatible hydroxyapatite (HAp nanopowder was developed. The process was conducted in a microwave radiation field having a high energy density of 5 W/mL and over a time less than 2 minutes. The sample measurements included: powder X-ray diffraction, density, specific surface area, and chemical composition. The morphology and structure were investigated by scanning electron microscopy as well as transmission electron microscopy (TEM. The thermal behavior analysis was conducted using a simultaneous thermal analysis technique coupled with quadruple mass spectrometry. Additionally, Fourier transform infrared spectroscopy tests of heated samples were performed. A degradation test and a biocompatibility study in vitro using human osteoblast cells were also conducted. The developed method enables the synthesis of pure, fully crystalline hexagonal HAp nanopowder with a specific surface area close to 240 m2/g and a Ca/P molar ratio equal to 1.57. TEM measurements showed that this method results in particles with an average grain size below 6 nm. A 28-day degradation test conducted according to the ISO standard indicated a 22% loss of initial weight and a calcium ion concentration at 200 µmol/dm3 in the tris(hydroxymethylaminomethane hydrochloride test solution. The cytocompatibility of the obtained material was confirmed in a culture of human bone derived cells, both in an indirect test using the material

  5. SiC detectors to monitor ionizing radiations emitted from nuclear events and plasmas

    Science.gov (United States)

    Torrisi, L.; Cannavò, A.

    2016-09-01

    Silicon Carbide (SiC) semiconductor detectors are increasingly employed in Nuclear Physics for their advantages with respect to traditional silicon (Si). Such detectors show an energy resolution, charge mobility, response velocity and detection efficiency similar to Si detectors. However, the higher band gap (3.26 eV), the lower leakage current (∼10 pA) maintained also at room temperature, the higher radiation hardness and the higher density with respect to Si represent some indisputable advantages characterizing such detectors. The devices can be employed at high temperatures, at high absorbed doses and in the case of high visible light intensities, for example, in plasma, for limited exposition times without damage. Generally SiC Schottky diodes are employed in reverse polarization with an active region depth of the order of 100 µm, purity below 1014 cm-3 and an active area lower than 1 cm2. Measurements in the regime of proportionality with the radiation energy released in the active region and measurements in time-of-flight configuration are employed for nuclear emission events produced at both low and high fluences. Alpha spectra demonstrated an energy resolution of about 1.3% at 5.8 MeV. Radiation emission from laser-generated plasma can be monitored in terms of detected photons, electrons and ions, using the laser pulse as a start signal and the radiation detection as a stop signal, enabling to measure the ion velocity by knowing the target-detector flight distance. SiC spectra acquired in the Messina University laboratories using radioactive ion sources and at the PALS laboratory facility in Prague (Czech Republic) are presented. A preliminary study of the use of SiC detectors, embedded in a water equivalent polymer, as a dosimeter is presented and discussed.

  6. A multi-layer discrete-ordinate method for vector radiative transfer in a vertically-inhomogeneous, emitting and scattering atmosphere. I - Theory. II - Application

    Science.gov (United States)

    Weng, Fuzhong

    1992-01-01

    A theory is developed for discretizing the vector integro-differential radiative transfer equation including both solar and thermal radiation. A complete solution and boundary equations are obtained using the discrete-ordinate method. An efficient numerical procedure is presented for calculating the phase matrix and achieving computational stability. With natural light used as a beam source, the Stokes parameters from the model proposed here are compared with the analytical solutions of Chandrasekhar (1960) for a Rayleigh scattering atmosphere. The model is then applied to microwave frequencies with a thermal source, and the brightness temperatures are compared with those from Stamnes'(1988) radiative transfer model.

  7. Temperature-specific inhibition of human red cell (Na/sup +//K/sup +/) ATPase by 2450-MHz microwave radiation

    Energy Technology Data Exchange (ETDEWEB)

    Allis, J.W.; Sinha-Robinson, B.L.

    1987-01-01

    The ATPase activity in human red blood cell membranes was investigated in vitro as a function of temperature and exposure to 2450-MHz (CW) microwave radiation. Assays were conducted spectrophotometrically during microwave exposure with a custom-made spectrophotometer-waveguide apparatus. Temperature profiles of total ATPase and Ca+2 ATPase (ouabain-inhibited) activity between 17 and 31 C were graphed as an Arrhenius plot. Each data set was fitted to two straight lines which intersected between 23 and 24 C. The difference between the total and Ca+2 ATPase activities, which represented the Na+/K+ ATPase activity, was also plotted and treated similarly to yield an intersection near 25 C. Exposure of membrane suspensions to a 6 W/kg dose rate at 1 C intervals between 23 and 27 C, resulted in an activity change only for the Na+/K+ ATPase at 25 C. The activity decreased by approximately 35% compared to sham-irradiated samples. An hypothesis based on the interaction of microwave radiation with enzyme structure during a conformational rearrangement is proposed as an explanation for the effect.

  8. Temperature-specific inhibition of human red cell Na+/K+ ATPase by 2450-MHz microwave radiation

    Energy Technology Data Exchange (ETDEWEB)

    Allis, J.W.; Sinha-Robinson, B.L.

    1987-01-01

    The ATPase activity in human red blood cell membranes was investigated in vitro as a function of temperature and exposure to 2450-MHz continuous wave microwave radiation to confirm and extend a report of Na+ transport inhibition under certain conditions of temperature and exposure. Assays were conducted spectrophotometrically during microwave exposure with a custom-made spectrophotometer-waveguide apparatus. Temperature profiles of total ATPase and Ca+2 ATPase (ouabain-inhibited) activity between 17 and 31 degrees C were graphed as an Arrhenius plot. Each data set was fitted to two straight lines which intersect between 23 and 24 degrees C. The difference between the total and Ca+2 ATPase activities, which represented the Na+/K+ ATPase activity, was also plotted and treated similarly to yield an intersection near 25 degrees C. Exposure of membrane suspensions to electromagnetic radiation, at a dose rate of 6 W/kg and at five temperatures between 23 and 27 degrees C, resulted in an activity change only for the Na+/K+ ATPase at 25 degrees C. The activity decreased by approximately 35% compared to sham-irradiated samples. A possible explanation for the unusual temperature/microwave interaction is proposed.

  9. Cosmic Microwave Background Timeline

    Science.gov (United States)

    Cosmic Microwave Background Timeline 1934 : Richard Tolman shows that blackbody radiation in an will have a blackbody cosmic microwave background with temperature about 5 K 1955: Tigran Shmaonov anisotropy in the cosmic microwave background, this strongly supports the big bang model with gravitational

  10. INTERACTION OF LASER RADIATION WITH MATTER: Influence of a target on operation of a pulsed CO2 laser emitting microsecond pulses

    Science.gov (United States)

    Baranov, V. Yu; Dolgov, V. A.; Malyuta, D. D.; Mezhevov, V. S.; Semak, V. V.

    1987-12-01

    The profile of pulses emitted by a TEA CO2 laser with an unstable resonator changed as a result of interaction of laser radiation with the surface of a metal in the presence of a breakdown plasma. This influence of a target on laser operation and its possible applications in laser processing of materials are analyzed.

  11. Comparative study of the use of non-ionizing and ionizing radiation in the cure of epoxy resin: microwave versus electron electron

    Energy Technology Data Exchange (ETDEWEB)

    Kersting, Daniel, E-mail: daniel.kersting@usp.br [Centro Tecnologico da Marinha em Sao Paulo (CTMSP/USP), Sao Paulo, SP (Brazil); Wiebeck, Helio, E-mail: hwiebeck@usp.br [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Escola Politecnica. Dept. de Engenharia Metalurgica; Marinucci, Gerson; Silva, Leonardo G.A. e, E-mail: marinuci@ipen.br, E-mail: gasilva@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Several processes for curing epoxy resins were developed over the years. Two methods are discussed in this paper, in order to present the main advantages and disadvantages of using microwave radiation (non-ionizing radiation) and electron beam radiation (ionizing radiation). The microwave radiation is a non-ionizing radiation, with great power of penetration and transfer of heat in microwave absorbing materials, or materials with microwave absorbing fillers. The frequency usually used in research and development is 2.45 GHz, the same available in commercial equipment. The microwave effect provides increase on the collision velocity between the reactant which, combined with energy absorbed by the reaction system, accelerates the curing reaction. None modifications in the epoxy system are required to use microwave heating for the curing process.On the other hand, the electron beam is a form of ionizing radiation in which the high energy electrons have the ability to interact with the irradiated material and produce ions, free radicals, and molecules in excited state, which can be used to initiate and propagate a polymerization. Specific initiators are necessary for an effective cure of the resin. In this study, a DGEBA epoxy resin with initiators based on anhydride and amine was used under the same conditions indicated by the manufacturer. The curing of the catalyzed system was performed in a domestic microwave oven adapted for laboratory use. The degradation and glass transition temperatures were evaluated by thermal analysis techniques. For comparative purposes, it was used data available in the literature for electron beam irradiation. (author)

  12. Comparative study of the use of non-ionizing and ionizing radiation in the cure of epoxy resin: microwave versus electron electron

    International Nuclear Information System (INIS)

    Kersting, Daniel; Wiebeck, Helio

    2013-01-01

    Several processes for curing epoxy resins were developed over the years. Two methods are discussed in this paper, in order to present the main advantages and disadvantages of using microwave radiation (non-ionizing radiation) and electron beam radiation (ionizing radiation). The microwave radiation is a non-ionizing radiation, with great power of penetration and transfer of heat in microwave absorbing materials, or materials with microwave absorbing fillers. The frequency usually used in research and development is 2.45 GHz, the same available in commercial equipment. The microwave effect provides increase on the collision velocity between the reactant which, combined with energy absorbed by the reaction system, accelerates the curing reaction. None modifications in the epoxy system are required to use microwave heating for the curing process.On the other hand, the electron beam is a form of ionizing radiation in which the high energy electrons have the ability to interact with the irradiated material and produce ions, free radicals, and molecules in excited state, which can be used to initiate and propagate a polymerization. Specific initiators are necessary for an effective cure of the resin. In this study, a DGEBA epoxy resin with initiators based on anhydride and amine was used under the same conditions indicated by the manufacturer. The curing of the catalyzed system was performed in a domestic microwave oven adapted for laboratory use. The degradation and glass transition temperatures were evaluated by thermal analysis techniques. For comparative purposes, it was used data available in the literature for electron beam irradiation. (author)

  13. Modeling and parameterization of photoelectrons emitted in condensed matter by linearly polarized synchrotron radiation

    Science.gov (United States)

    Jablonski, A.

    2018-01-01

    Growing availability of synchrotron facilities stimulates an interest in quantitative applications of hard X-ray photoemission spectroscopy (HAXPES) using linearly polarized radiation. An advantage of this approach is the possibility of continuous variation of radiation energy that makes it possible to control the sampling depth for a measurement. Quantitative applications are based on accurate and reliable theory relating the measured spectral features to needed characteristics of the surface region of solids. A major complication in the case of polarized radiation is an involved structure of the photoemission cross-section for hard X-rays. In the present work, details of the relevant formalism are described and algorithms implementing this formalism for different experimental configurations are proposed. The photoelectron signal intensity may be considerably affected by variation in the positioning of the polarization vector with respect to the surface plane. This information is critical for any quantitative application of HAXPES by polarized X-rays. Different quantitative applications based on photoelectrons with energies up to 10 keV are considered here: (i) determination of surface composition, (ii) estimation of sampling depth, and (iii) measurements of an overlayer thickness. Parameters facilitating these applications (mean escape depths, information depths, effective attenuation lengths) were calculated for a number of photoelectron lines in four elemental solids (Si, Cu, Ag and Au) in different experimental configurations and locations of the polarization vector. One of the considered configurations, with polarization vector located in a plane perpendicular to the surface, was recommended for quantitative applications of HAXPES. In this configurations, it was found that the considered parameters vary weakly in the range of photoelectron emission angles from normal emission to about 50° with respect to the surface normal. The averaged values of the mean

  14. Blood-brain barrier permeation in the rat during exposure to low-power 1.7-GHz microwave radiation

    International Nuclear Information System (INIS)

    Ward, T.R.; Ali, J.S.

    1985-01-01

    The permeability of the blood-brain barrier to high-and low-molecular-weight compounds has been measured as a function of continuous-wave (CW) and pulsed-microwave radiation. Adult rats, anesthetized with pentobarbital and injected intravenously with a mixture of [ 14 C] sucrose and [ 3 H] inulin, were exposed for 30 min at a specific absorption rate of 0.1 W/kg to 1.7-GHz CW and pulsed (0.5-microseconds pulse width, 1,000 pps) microwaves. After exposure, the brain was perfused and sectioned into nine regions, and the radioactivity in each region was counted. During identical exposure conditions, temperatures of rats were measured in eight of the brain regions by a thermistor probe that did not perturb the field. No change in uptake of either tracer was found in any of the eight regions as compared with those of sham-exposed animals

  15. Effects of gamma rays, ultraviolet radiation, sunlight, microwaves and electromagnetic fields on gene expression mediated by human immunodeficiency virus promoter

    International Nuclear Information System (INIS)

    Libertin, C.R.; Woloschak, G.E.; Panozzo, J.; Groh, K.R.; Chang-Liu, Chin-Mei; Schreck, S.

    1994-01-01

    Previous work by our group and others has shown the modulation of human immunodeficiency virus (HIV) promoter or long terminal repeat (LTR) after exposure to neutrons and ultraviolet radiations. Using HeLa cells stably transfected with a construct containing the chloramphenicol acetyl transferase (CAT) gene, the transcription of which is mediated by the HIV-LTR, we designed experiments to examine the effects of exposure to different types of radiation (such as γ rays, ultraviolet and sunlight irradiations, electromagnetic fields and microwaves) in HIV-LTR-driven expression of CAT. These results demonstrated ultraviolet-light-induced transcription from the HIV promoter, as has been shown by others. Exposure to other DNA-damaging agents such as γ rays and sunlight (with limited exposures) had no significant effect on transcription mediated by HIV-LTR, suggesting that induction of HIV is not mediated by just any type of DNA damage but rather may require specific types of DNA damage. Microwaves did not cause cell killing when cells in culture were exposed in high volumes of medium, and the same cells showed no changes in expression. When microwave exposure was carried out in low volumes of medium (so that excessive heat was generated) induction of HIV-LTR transcription (as assayed by CAT activity) was evident. Electromagnetic field exposures had no effect on expression of HIV-LTR. These results demonstrate that not all types of radiation and not all DNA-damaging agents are capable of inducing HIV. We hypothesize that induction of HIV transcription may be mediated by several different signals exposure to radiation. 22 refs., 8 figs

  16. The relationship between cellular adhesion and surface roughness for polyurethane modified by microwave plasma radiation

    Directory of Open Access Journals (Sweden)

    Heidari S

    2011-04-01

    Full Text Available Saeed Heidari Keshel1, S Neda Kh Azhdadi2, Azadeh Asefnezhad2, Mohammad Sadraeian3, Mohamad Montazeri4, Esmaeil Biazar51Stem Cell Preparation Unit, Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences; 2Department of Biomaterial Engineering, Faculty of Biomedical Engineering, Science and Research Branch - Islamic Azad University; 3Young Researchers Club, Islamic Azad University, North Tehran Branch, Tehran; 4Faculty of Medical Sciences, Babol University of Medical Sciences, Babol; 5Department of Chemistry, Islamic Azad University, Tonekabon, IranAbstract: Surface modification of medical polymers is carried out to improve biocompatibility. In this study, conventional polyurethane was exposed to microwave plasma treatment with oxygen and argon gases for 30 seconds and 60 seconds. Attenuated total reflection Fourier transform infrared spectra investigations of irradiated samples indicated the presence of functional groups. Atomic force microscope images of samples irradiated with inert and active gases indicated the nanometric topography of the sample surfaces. Samples irradiated by oxygen plasma indicated high roughness compared with those irradiated by inert plasma for the different lengths of time. In addition, surface roughness increased with time, which can be due to a reduction of contact angle of samples irradiated by oxygen plasma. Contact angle analysis indicated a reduction in samples irradiated with both types of plasma. However, samples irradiated with oxygen plasma indicated lower contact angle compared with those irradiated by argon plasma. Cellular investigations with unrestricted somatic stem cells showed better adhesion, cell growth, and proliferation among samples radiated by oxygen plasma for longer than for normal samples.Keywords: surface topography, polyurethane, plasma treatment, cellular investigation

  17. Sensitivity to Antibiotics of Bacteria Exposed to Gamma Radiation Emitted from Hot Soils of the High Background Radiation Areas of Ramsar, Northern Iran.

    Science.gov (United States)

    Mortazavi, Seyed Mohammad Javad; Zarei, Samira; Taheri, Mohammad; Tajbakhsh, Saeed; Mortazavi, Seyed Alireza; Ranjbar, Sahar; Momeni, Fatemeh; Masoomi, Samaneh; Ansari, Leila; Movahedi, Mohammad Mehdi; Taeb, Shahram; Zarei, Sina; Haghani, Masood

    2017-04-01

    Over the past several years our laboratories have investigated different aspects of the challenging issue of the alterations in bacterial susceptibility to antibiotics induced by physical stresses. To explore the bacterial susceptibility to antibiotics in samples of Salmonella enterica subsp. enterica serovar Typhimurium ( S. typhimurium ), Staphylococcus aureus , and Klebsiella pneumoniae after exposure to gamma radiation emitted from the soil samples taken from the high background radiation areas of Ramsar, northern Iran. Standard Kirby-Bauer test, which evaluates the size of the zone of inhibition as an indicator of the susceptibility of different bacteria to antibiotics, was used in this study. The maximum alteration of the diameter of inhibition zone was found for K. pneumoniae when tested for ciprofloxacin. In this case, the mean diameter of no growth zone in non-irradiated control samples of K. pneumoniae was 20.3 (SD 0.6) mm; it was 14.7 (SD 0.6) mm in irradiated samples. On the other hand, the minimum changes in the diameter of inhibition zone were found for S. typhimurium and S. aureus when these bacteria were tested for nitrofurantoin and cephalexin, respectively. Gamma rays were capable of making significant alterations in bacterial susceptibility to antibiotics. It can be hypothesized that high levels of natural background radiation can induce adaptive phenomena that help microorganisms better cope with lethal effects of antibiotics.

  18. Sensitivity to Antibiotics of Bacteria Exposed to Gamma Radiation Emitted from Hot Soils of the High Background Radiation Areas of Ramsar, Northern Iran

    Directory of Open Access Journals (Sweden)

    Seyed Mohammad Javad Mortazavi

    2017-04-01

    Full Text Available Background: Over the past several years our laboratories have investigated different aspects of the challenging issue of the alterations in bacterial susceptibility to antibiotics induced by physical stresses. Objective: To explore the bacterial susceptibility to antibiotics in samples of Salmonella enterica subsp. enterica serovar Typhimurium (S. typhimurium, Staphylococcus aureus, and Klebsiella pneumoniae after exposure to gamma radiation emitted from the soil samples taken from the high background radiation areas of Ramsar, northern Iran. Methods: Standard Kirby-Bauer test, which evaluates the size of the zone of inhibition as an indicator of the susceptibility of different bacteria to antibiotics, was used in this study. Results: The maximum alteration of the diameter of inhibition zone was found for K. pneumoniae when tested for ciprofloxacin. In this case, the mean diameter of no growth zone in non-irradiated control samples of K. pneumoniae was 20.3 (SD 0.6 mm; it was 14.7 (SD 0.6 mm in irradiated samples. On the other hand, the minimum changes in the diameter of inhibition zone were found for S. typhimurium and S. aureus when these bacteria were tested for nitrofurantoin and cephalexin, respectively. Conclusion: Gamma rays were capable of making significant alterations in bacterial susceptibility to antibiotics. It can be hypothesized that high levels of natural background radiation can induce adaptive phenomena that help microorganisms better cope with lethal effects of antibiotics.

  19. Opto-microwave, Butler matrixes based front-end for a multi-beam large direct radiating array antenna

    Science.gov (United States)

    Piqueras, M. A.; Mengual, T.; Navasquillo, O.; Sotom, M.; Caille, G.

    2017-11-01

    The evolution of broadband communication satellites shows a clear trend towards beam forming and beamswitching systems with efficient multiple access schemes with wide bandwidths, for which to be economically viable, the communication price shall be as low as possible. In such applications, the most demanding antenna concept is the Direct Radiating Array (DRA) since its use allows a flexible power allocation between beams and may afford failures in their active chains with low impact on the antenna radiating pattern. Forming multiple antenna beams, as for `multimedia via satellite' missions, can be done mainly in three ways: in microwave domain, by digital or optical processors: - Microwave beam-formers are strongly constrained by the mass and volume of microwave devices and waveguides - the bandwidth of digital processors is limited due to power consumption and complexity constraints. - The microwave photonics is an enabling technology that can improve the antenna feeding network performances, overcoming the limitations of the traditional technology in the more demanding scenarios, and may overcome the conventional RF beam-former issues, to generate accurately the very numerous time delays or phase shifts required in a DRA with a large number of beams and of radiating elements. Integrated optics technology can play a crucial role as an alternative technology for implementing beam-forming structures for satellite applications thanks to the well known advantages of this technology such as low volume and weight, huge electrical bandwidth, electro-magnetic interference immunity, low consumption, remote delivery capability with low-attenuation (by carrying all microwave signals over optical fibres) and the robustness and precision that exhibits integrated optics. Under the ESA contract 4000105095/12/NL/RA the consortium formed by DAS Photonics, Thales Alenia Space and the Nanophotonic Technology Center of Valencia is developing a three-dimensional Optical Beamforming

  20. Manipulating ultracold polar molecules with microwave radiation: The influence of hyperfine structure

    International Nuclear Information System (INIS)

    Aldegunde, J.; Hutson, Jeremy M.; Ran Hong

    2009-01-01

    We calculate the microwave spectra of ultracold 40 K 87 Rb alkali-metal dimers, including hyperfine interactions and in the presence of electric and magnetic fields. We show that microwave transitions may be used to transfer molecules between different hyperfine states, but only because of the presence of nuclear quadrupole interactions. Hyperfine splittings may also complicate the use of ultracold molecules for quantum computing. The spectrum of molecules oriented in electric fields may be simplified dramatically by applying a simultaneous magnetic field.

  1. Radiation effects in light emitting diodes, laser diodes, photodiodes and optocouplers

    International Nuclear Information System (INIS)

    Lischka, H.; Henschel, H.; Koehn, O.; Lennartz, W.; Schmidt, H.U.

    1994-01-01

    A variety of commercially available LEDs, LDs, PDs, and optocouplers from two German manufacturers were irradiated at a flash X-ray source, a 60 Co gamma ray source, and a 14 MeV neutron generator. Light output and emission spectrum of the LEDs and LDs were measured before and after irradiation at the 60 Co source. With the PDs we measured the dark current and the photo current before and after 60 Co irradiation. Determination of the sensitivity against neutrons was made off-line. With PDs we measured the photo current induced by pulsed X-rays. The GaAs LED showed a maximum decrease of output power of 28 dB after a total gamma dose of 10 6 Gy and LDs a threshold current shift of 80% after neutron fluences of 4 - 10 14 cm -2 (1 MeV). Irradiations of PDs and APDs with 60 Co gammas up to a total dose of 10 6 Gy as well as irradiations with neutrons up to fluences of ≤ 4 - 10 14 cm -2 (1 MeV) led to significant changes of the device parameters. The main effect was a strong increase of the dark current. The consequence was a reduction of the minimum detectable light power. Optocouplers are very sensitive to ionizing radiation. Gammas as well as neutrons led to a decrease of the CTR and a change of the bandwidth up to a complete failure (after neutron irradiation). (author). 9 refs., 11 figs., 4 tabs

  2. Wideband analysis of railway catenary line radiation and new applications of its unintentional emitted signals

    Science.gov (United States)

    Heddebaut, Marc; Deniau, Virginie; Rioult, Jean

    2018-06-01

    Generally, in railway networks, dissipated energy—and its consequences in terms of noise, ballast attrition, electromagnetic interference, etc—is considered a nuisance generated by this means of transport. Therefore, most studies are carried out with the aim of reducing it. This paper takes the opposite view and considers the particular case of the irreducible electromagnetic interference generated along an electrified line, in order to propose new applications beneficial to railway operations. At a selected representative location, wideband (ranging from 10 kHz to 1 GHz) electromagnetic field measurements are performed successively during, and not during, high speed train passages. We deduce two potential applications of these unintentional signals. At low frequency, the first proposal considers energy harvesting using the received electromagnetic interference as the source. This received energy can be converted and used to DC feed low consumption sensors to be installed along the railway infrastructure. These sensors participate in monitoring infrastructure health and in making it more resilient to internal and external stresses. At higher frequencies, for the second proposal, radiation from the catenary line and train pantograph is specifically examined at a carefully selected sub-band. The results are also studied following a time–frequency analysis, to introduce a new nondestructive inspection method of the sliding contact between the catenary line and the train pantograph. Ultimately, this technique could offer a new means of monitoring the health of both the catenary line and the pantograph.

  3. Three-dimensional inhomogeneous rain fields: implications for the distribution of intensity and polarization of the microwave thermal radiation.

    Science.gov (United States)

    Ilyushin, Yaroslaw; Kutuza, Boris

    Observations and mapping of the upwelling thermal radiation of the Earth is the very promising remote sensing technique for the global monitoring of the weather and precipitations. For reliable interpretation of the observation data, numerical model of the microwave radiative transfer in the precipitating atmosphere is necessary. In the present work, numerical simulations of thermal microwave radiation in the rain have been performed at three wavelengths (3, 8 and 22 mm). Radiative properties of the rain have been simulated using public accessible T-matrix codes (Mishchenko, Moroz) for non-spherical particles of fixed orientation and realistic raindrop size distributions (Marshall-Palmer) within the range of rain intensity 1-100 mm/h. Thermal radiation of infinite flat slab medium and isolated rain cell of kilometer size has been simulated with finite difference scheme for the vectorial radiative transfer equation (VRTE) in dichroic scattering medium. Principal role of cell structure of the rain field in the formation of angular and spatial distribution of the intensity and polarization of the upwelling thermal radiation has been established. Possible approaches to interpretation of satellite data are also discussed. It is necessary that spatial resolution of microwave radiometers be less than rain cell size. At the present time the resolution is approximately 15 km. It can be considerably improved, for example by two-dimensional synthetic aperture millimeter-wave radiometric interferometer for measuring full-component Stokes vector of emission from hydrometeors. The estimates show that in millimeter band it is possible to develop such equipment with spatial resolution of the order of 1-2 km, which is significantly less than the size of rain cell, with sensitivity 0.3-0.5 K. Under this condition the second Stokes parameter may by successfully measured and may be used for investigation of precipitation regions. Y-shaped phased array antenna is the most promising to

  4. Industrial assessment of radiofrequency and microwave radiations: case study at electronic manufacturing industries in Penang

    International Nuclear Information System (INIS)

    Mohd Zaid Abdullah

    1996-01-01

    In electronic manufacturing industry, the applications of an equipment emitting radiofrequency radiation (RFR) are numerous and Increasing. It is known that exposure to RFR at sufficiently high intensity and duration can produce a variety of adverse health effects. This paper presents some results from an extensive studies in the RFR field measurements at frequency range from 100 MHz to 1 GHz. All measurements were performed inside factories located at the Penang Free Trade Zone. In this case, the factories chosen are those that manufacture the electronic components whereby the applications of RFR equipment are likely to be intensive compared to other type of industries. The measurement system used in this study are the portable spectrum-analyzer, the passive log-periodic antenna and a desktop computer for data analysis. Results from this study have indicated that the RFR exposure levels in most factories are in the range of 7.7 x 10 sup -4 - 4.31 x 10 sup -3 Wm sup -2 and 0.01 - 0. 741 Vm sup -1 for power density and electric strength measurement respectively. These ranges are at least 100 times lower compared to the RFR protection guidelines proposed by the American National Standard Institute (ANSI). However, the exposure levels inside the factory are consistently 10 sup -3 - 10 sup -4 higher than the levels caused by natural sources and is about 10 sup 2 - 10 sup 6 higher than the levels measured at a distance of 30 m from a low-power output mobile phone transmitter. In the case of the health effect assessment, no sufficient evidence has been found to indicate the potential consequences resulting from excessive RFR exposure. Nonetheless, many factories surveyed are unaware of the existence of the international guidelines and codes on the safe use of radiofrequency energy even though, some measures are being taken to protect their employees against RFR

  5. Fabrication of novel structures to enhance the performance of microwave, millimeter wave and optical radiators

    Science.gov (United States)

    Gbele, Kokou

    This dissertation has three parts which are distinctive from the perspective of their frequency regime of operation and from the nature of their contributions to the science and engineering communities. The first part describes work that was conducted on a vertical-external-cavity surface emitting-laser (VECSEL) in the optical frequency regime. We designed, fabricated, and tested a hybrid distributed Bragg reflector (DBR) mirror for a VECSEL sub-cavity operating at the laser emission wavelength of 1057 nm. The DBR mirror was terminated with a highly reflecting gold surface and integrated with an engineered pattern of titanium. This hybrid mirror achieved a reduction in half of the number of DBR layer pairs in comparison to a previously reported, successful VECSEL chip. Moreover, the output power of our VECSEL chip was measured to be beyond 4.0Wwith an optical-to-optical efficiency of 19.4%. Excellent power output stability was demonstrated; a steady 1.0 W output at 15.0 W pump power was measured for over an hour. The second part reports on an ultrafast in situ pump-probing of the nonequlibrium dynamics of the gain medium of a VECSEL under mode-locked conditions. We proposed and successfully tested a novel approach to measure the response of the inverted carriers in the active region of a VECSEL device while it was operating under passively mode-locked conditions. We employed the dual-frequency-comb spectroscopy (DFCS) technique using an asynchronous optical sampling (ASOPS) method based on modified time-domain spectroscopy (TDS) to measure the nonequilibrium dynamics of the gain medium of a phase-locked VECSEL that we designed and fabricated to operate at the 1030 nm emission wavelength. Our spectroscopic studies used a probe pulse of 100 fs and an in situ pump pulse of 13 ps. We probed the gain medium of the VECSEL and recorded a depletion time of 13 ps, a fast recovery period of 17 ps, and 110 ps for the slow recovery time. Our scans thus demonstrated a 140 ps

  6. Detailed spectra of high power broadband microwave radiation from interactions of relativistic electron beams with weakly magnetized plasmas

    International Nuclear Information System (INIS)

    Kato, K.G.; Benford, G.; Tzach, D.

    1983-01-01

    Prodigious quantities of microwave energy are observed uniformly across a wide frequency band when a relativistic electron beam (REB) penetrates a plasma. Measurement calculations are illustrated. A model of Compton-like boosting of ambient plasma waves by beam electrons, with collateral emission of high frequency photons, qualitatively explain the spectra. A transition in spectral behavior is observed from the weak to strong turbulence theories advocated for Type III solar burst radiation, and further into the regime the authors characterize as super-strong REB-plasma interactions

  7. The cosmic microwave background radiation power spectrum as a random bit generator for symmetric- and asymmetric-key cryptography

    Directory of Open Access Journals (Sweden)

    Jeffrey S. Lee

    2017-10-01

    Full Text Available In this note, the Cosmic Microwave Background (CMB Radiation is shown to be capable of functioning as a Random Bit Generator, and constitutes an effectively infinite supply of truly random one-time pad values of arbitrary length. It is further argued that the CMB power spectrum potentially conforms to the FIPS 140-2 standard. Additionally, its applicability to the generation of a (n × n random key matrix for a Vernam cipher is established. Keywords: Particle physics, Computer science, Mathematics, Astrophysics

  8. Automated Computer-Based Facility for Measurement of Near-Field Structure of Microwave Radiators and Scatterers

    DEFF Research Database (Denmark)

    Mishra, Shantnu R.;; Pavlasek, Tomas J. F.;; Muresan, Letitia V.

    1980-01-01

    An automatic facility for measuring the three-dimensional structure of the near fields of microwave radiators and scatterers is described. The amplitude and phase for different polarization components can be recorded in analog and digital form using a microprocessor-based system. The stored data...... are transferred to a large high-speed computer for bulk processing and for the production of isophot and equiphase contour maps or profiles. The performance of the system is demonstrated through results for a single conical horn, for interacting rectangular horns, for multiple cylindrical scatterers...

  9. The effect of electromagnetic radiation emitted by display screens on cell oxygen metabolism – in vitro studies

    Science.gov (United States)

    Henrykowska, Gabriela A.; Pacholski, Krzysztof; Śmigielski, Janusz; Rutkowski, Maciej; Dziedziczak-Buczyńska, Maria; Buczyński, Andrzej

    2015-01-01

    Introduction Research studies carried out for decades have not solved the problem of the effect of electromagnetic radiation of various frequency and strength on the human organism. Due to this fact, we decided to investigate the changes taking place in human blood platelets under the effect of electromagnetic radiation (EMR) emitted by LCD monitors. Material and methods The changes of selected parameters of oxygen metabolism were measured, i.e. reactive oxygen species concentration, enzymatic activity of antioxidant defence proteins – superoxide dismutase (SOD-1) and catalase (CAT) – and malondialdehyde concentration (MDA). A suspension of human blood platelets was exposed to electromagnetic radiation of 1 kHz frequency and 150 V/m and 220 V/m intensity for 30 and 60 min. The level of changes of the selected parameters of oxidative stress was determined after the exposure and compared to the control samples (not exposed). Results The measurements revealed an increase of the concentration of reactive oxygen species. The largest increase of ROS concentration vs. the control sample was observed after exposure to EMF of 220 V/m intensity for 60 min (from x = 54.64 to x = 72.92). The measurement of MDA concentration demonstrated a statistically significant increase after 30-min exposure to an EMF of 220 V/m intensity in relation to the initial values (from x = 3.18 to x = 4.41). The enzymatic activity of SOD-1 decreased after exposure (the most prominent change was observed after 60-min and 220 V/m intensity from x = 3556.41 to x = 1084.83). The most significant change in activity of catalase was observed after 60 min and 220 v/m exposure (from x = 6.28 to x = 4.15). Conclusions The findings indicate that exposure to electromagnetic radiation of 1 kHz frequency and 150 V/m and 220 V/m intensity may cause adverse effects within blood platelets’ oxygen metabolism and thus may lead to physiological dysfunction of the organism. PMID:26788099

  10. Development of Radiation-Resistant In-Water Wireless Transmission System Using Light Emitting Diodes and Photo Diodes

    Science.gov (United States)

    Takeuchi, T.; Shibata, H.; Otsuka, N.; Uehara, T.; Tsuchiya, K.; Shibagaki, T.; Komanome, H.

    2016-10-01

    Several kinds of commercially available light emitting diodes (LED) and photo diodes (PD) were irradiated with 60Co gamma ray up to 1 MGy for development of a radiation-resistant in-water wireless transmission system using visible light. The lens parts of the LEDs turned brown by the irradiation and their colors became dark with the absorbed dose. The total luminous fluxes decreased with the absorbed dose and the LED with shorter emission wavelength had the higher decrease rate. Meanwhile, the current-voltage characteristics hardly changed. These results indicate that the decreases of the total luminous flux of the LEDs were mainly caused not by the degradation of the semiconductor parts but by the coloring of the lens parts by the irradiation. On the other hand, the light sensitivities of the PDs decreased with the absorbed dose. The PDs with the window part which turned a darker color had the higher decrease rate. These results indicate that the decreases of light sensitivities of the PDs were also mainly caused by the coloring of the resin parts by the irradiation. If the wireless transmission is performed using the candidate LED and PD between 5 meters in water, using a few LEDs and PDs, the PD's output current generated by the emission light of the LED is estimated to be detectable even considering the effects of the absorption of the light in water and the increased dark current by the irradiation. Therefore, a radiation resistant in-water transmission system can be constructed using commercially available LEDs and PDs in principle.

  11. Efficient Computation of Coherent Synchrotron Radiation Taking into Account 6D Phase Space Distribution of Emitting Electrons

    International Nuclear Information System (INIS)

    Chubar, O.; Couprie, M.-E.

    2007-01-01

    CPU-efficient method for calculation of the frequency domain electric field of Coherent Synchrotron Radiation (CSR) taking into account 6D phase space distribution of electrons in a bunch is proposed. As an application example, calculation results of the CSR emitted by an electron bunch with small longitudinal and large transverse sizes are presented. Such situation can be realized in storage rings or ERLs by transverse deflection of the electron bunches in special crab-type RF cavities, i.e. using the technique proposed for the generation of femtosecond X-ray pulses (A. Zholents et. al., 1999). The computation, performed for the parameters of the SOLEIL storage ring, shows that if the transverse size of electron bunch is larger than the diffraction limit for single-electron SR at a given wavelength -- this affects the angular distribution of the CSR at this wavelength and reduces the coherent flux. Nevertheless, for transverse bunch dimensions up to several millimeters and a longitudinal bunch size smaller than hundred micrometers, the resulting CSR flux in the far infrared spectral range is still many orders of magnitude higher than the flux of incoherent SR, and therefore can be considered for practical use

  12. The AMY experiment: Microwave emission from air shower plasmas

    Directory of Open Access Journals (Sweden)

    Alvarez-Muñiz J.

    2016-01-01

    Full Text Available You The Air Microwave Yield (AMY experiment investigate the molecular bremsstrahlung radiation emitted in the GHz frequency range from an electron beam induced air-shower. The measurements have been performed at the Beam Test Facility (BTF of Frascati INFN National Laboratories with a 510 MeV electron beam in a wide frequency range between 1 and 20 GHz. We present the apparatus and the results of the tests performed.

  13. NEW Fe IX LINE IDENTIFICATIONS USING SOLAR AND HELIOSPHERIC OBSERVATORY/SOLAR ULTRAVIOLET MEASUREMENT OF EMITTED RADIATION AND HINODE/EIS JOINT OBSERVATIONS OF THE QUIET SUN

    International Nuclear Information System (INIS)

    Landi, E.; Young, P. R.

    2009-01-01

    In this work, we study joint observations of Hinode/EUV Imaging Spectrometer (EIS) and Solar and Heliospheric Observatory/Solar Ultraviolet Measurement of Emitted Radiation of Fe IX lines emitted by the same level of the high energy configuration 3s 2 3p 5 4p. The intensity ratios of these lines are dependent on atomic physics parameters only and not on the physical parameters of the emitting plasma, so that they are excellent tools to verify the relative intensity calibration of high-resolution spectrometers that work in the 170-200 A and 700-850 A wavelength ranges. We carry out extensive atomic physics calculations to improve the accuracy of the predicted intensity ratio, and compare the results with simultaneous EIS-SUMER observations of an off-disk quiet Sun region. We were able to identify two ultraviolet lines in the SUMER spectrum that are emitted by the same level that emits one bright line in the EIS wavelength range. Comparison between predicted and measured intensity ratios, wavelengths and energy separation of Fe IX levels confirms the identifications we make. Blending and calibration uncertainties are discussed. The results of this work are important for cross-calibrating EIS and SUMER, as well as future instrumentation.

  14. Microwave radiation hydrothermal synthesis and characterization of micro- and mesoporous composite molecular sieve Y/SBA-15

    Directory of Open Access Journals (Sweden)

    Wenyuan Wu

    2017-05-01

    Full Text Available A microwave radiation hydrothermal method to control synthesis of micro- and mesoporous Y/SBA-15 composite molecular sieves was reported. The synthesized SBA-15 and Y/SBA-15 were characterized by scanning electron microscopy (SEM and N2 adsorption–desorption. The three kinds of different concentrations of hydrochloric acid (0.75 M, 2 M and 3.25 M were used to investigate the effect on Y/SBA-15. The analysis results of the composite products indicated that the optimization synthesis condition employed zeolite type Y and TEOS as silicon sources under 0.75 M hydrochloric acid by the microwave radiation hydrothermal synthesis method. The N2 adsorption–desorption test results of micro–mesoporous composite molecular sieve type Y/SBA-15 in mesoporous extent indicated that SBET is 355.529 m2/g, D‾BET is 4.050 nm, and mesoporous aperture focuses on the distribution region of 5.3 nm. It was found that the received composite product has an appropriate proportion of smaller size, larger size pore structure and the thicker pore wall. In addition, its internal channels have a high degree of order and smooth flow in long-range channels.

  15. Extreme ultraviolet spectroscopy of low pressure helium microwave driven discharges

    Science.gov (United States)

    Espinho, Susana; Felizardo, Edgar; Tatarova, Elena; Alves, Luis Lemos

    2016-09-01

    Surface wave driven discharges are reliable plasma sources that can produce high levels of vacuum and extreme ultraviolet radiation (VUV and EUV). The richness of the emission spectrum makes this type of discharge a possible alternative source in EUV/VUV radiation assisted applications. However, due to challenging experimental requirements, publications concerning EUV radiation emitted by microwave plasmas are scarce and a deeper understanding of the main mechanisms governing the emission of radiation in this spectral range is required. To this end, the EUV radiation emitted by helium microwave driven plasmas operating at 2.45 GHz has been studied for low pressure conditions. Spectral lines from excited helium atoms and ions were detected via emission spectroscopy in the EUV/VUV regions. Novel data concerning the spectral lines observed in the 23 - 33 nm wavelength range and their intensity behaviour with variation of the discharge operational conditions are presented. The intensity of all the spectral emissions strongly increases with the microwave power delivered to the plasma up to 400 W. Furthermore, the intensity of all the ion spectral emissions in the EUV range decreases by nearly one order of magnitude as the pressure was raised from 0.2 to 0.5 mbar. Work funded by FCT - Fundacao para a Ciencia e a Tecnologia, under Project UID/FIS/50010/2013 and grant SFRH/BD/52412/2013 (PD-F APPLAuSE).

  16. Study of viability on the destruction of weed seeds in the soil by microwave radiation

    International Nuclear Information System (INIS)

    Velazquez-Marti, B.; Osca, J.M.; Jorda, C.; Marzal, A.

    2003-01-01

    This work has been carried out to study the thermic effects over weed seeds in typical orchard soil irradiated by its surface with microwave. A previous treatment was carried out in a domestic microwave oven, using 660-watt power. With this laboratory oven, we have investigated three kind of weed seeds: Lolium perenne, Sinopsis alba and Setaria sativa. These previous experiments showed a important decrease of germination with short irradiating times. After previous treatment, a microwave applicator, designed to achieve wide distribution of superficial irradiation energy, was evaluated. This applicator is powered by a 4-kilowatt magnetron through a slotted waveguide. With this oven, we have investigated two kind of weed seeds at several depths: Lolium perenne and Brassica napus var. oleifera. For a soil column, temperature increments reduce seeds germination to a maximum of 5 centimetres. Deeper, the increments of temperature are very low for short irradiating times, so it will be negligible for our purpose. This applicator lets approach better to real treatments focused into the development of a continuous microwave oven for disinfecting seedbed and greenhouse crop substratum. (author) [es

  17. Radiofrequency/Microwave Radiation Biological Effects and Safety Standards: A Review

    Science.gov (United States)

    1994-06-01

    reported that a 50 year old woman had developed cataracts after intermittent exposure to a 2.45 GHz microwave oven. The incident power density levels were...include: Survelance, Communications, Command and Control, Intelligence, Signal Processing, Computer Sience and Technology, Electrom Technology, Photoracs and laiity Saences. S* I l I

  18. Study of microwave emission from a dense plasma focus

    International Nuclear Information System (INIS)

    Gerdin, G.; Venneri, F.; Tanisi, M.

    1985-01-01

    Microwave emission was detected in a 12.5 kJ dense plasma focus, using microwave horns and detectors placed in various locations outside the device. The results show that the parallel plates connecting the focus to its capacitor banks act as antennas and transmission lines, rather than wave guides. Subsequent measurements were performed with a microwave detector (R-band) attached to the focus anode, directly looking into the coaxial gun region, allowing to restrict the microwave emitting region to the muzzle end of the focus. The microwave frequency spectrum, determined with a time of flight detection system, strongly suggests the lower hybrid instability as the driving mechanism of the emissions. Comparing the time sequence of the emissions with those of other observable phenomena in the focus, a model was developed, to explain the possible relationship between the generation of microwave radiation and turbulence induced resistivity in the focus pinch. According to the model, microwaves and enhanced resistivity are caused by current driven instabilities occurring in the current sheath produced at the outer boundary of the pinch during the initial compression phase. Comparisons of the model predictions with observed experimental results are presented, including time resolved measurements of the pinch resistivity

  19. GARLIC — A general purpose atmospheric radiative transfer line-by-line infrared-microwave code: Implementation and evaluation

    International Nuclear Information System (INIS)

    Schreier, Franz; Gimeno García, Sebastián; Hedelt, Pascal; Hess, Michael; Mendrok, Jana; Vasquez, Mayte; Xu, Jian

    2014-01-01

    A suite of programs for high resolution infrared-microwave atmospheric radiative transfer modeling has been developed with emphasis on efficient and reliable numerical algorithms and a modular approach appropriate for simulation and/or retrieval in a variety of applications. The Generic Atmospheric Radiation Line-by-line Infrared Code — GARLIC — is suitable for arbitrary observation geometry, instrumental field-of-view, and line shape. The core of GARLIC's subroutines constitutes the basis of forward models used to implement inversion codes to retrieve atmospheric state parameters from limb and nadir sounding instruments. This paper briefly introduces the physical and mathematical basics of GARLIC and its descendants and continues with an in-depth presentation of various implementation aspects: An optimized Voigt function algorithm combined with a two-grid approach is used to accelerate the line-by-line modeling of molecular cross sections; various quadrature methods are implemented to evaluate the Schwarzschild and Beer integrals; and Jacobians, i.e. derivatives with respect to the unknowns of the atmospheric inverse problem, are implemented by means of automatic differentiation. For an assessment of GARLIC's performance, a comparison of the quadrature methods for solution of the path integral is provided. Verification and validation are demonstrated using intercomparisons with other line-by-line codes and comparisons of synthetic spectra with spectra observed on Earth and from Venus. - Highlights: • High resolution infrared-microwave radiative transfer model. • Discussion of algorithmic and computational aspects. • Jacobians by automatic/algorithmic differentiation. • Performance evaluation by intercomparisons, verification, validation

  20. Propagation of microwave radiation through an inhomogeneous plasma layer in a magnetic field

    Science.gov (United States)

    Balakirev, B. A.; Bityurin, V. A.; Bocharov, A. N.; Brovkin, V. G.; Vedenin, P. V.; Mashek, I. Ch; Pashchina, A. S.; Pervov, A. Yu; Petrovskiy, V. P.; Ryazanskiy, N. M.; Shkatov, O. Yu

    2018-01-01

    The problem of reliable microwave communication through a plasma sheath has its origin from the beginning of space flights. During reentry of spacecraft, the plasma layer can interrupt the communication. At sufficiently high plasma density, the plasma layer either reflects or attenuates radio wave communications to and from the vehicle. In this work, we present a simple analytical one-dimensional algorithm to study the propagation of electromagnetic (EM) waves through a nonuniform plasma layer in a static nonuniform magnetic field. The experimental study of the EM wave transmission and reflection through plasma layer was carried out on the (i) microwave set and (ii) on the unit using a high-voltage pulsed discharge.

  1. Study of properties of chloroprene rubber devulcanizate by radiation in microwave

    Energy Technology Data Exchange (ETDEWEB)

    Scagliusi, Sandra R.; Araujo, Sumair G.; Landini, Liliane; Lugao, Ademar B., E-mail: scagliusi@usp.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    Among the vulcanized elastomers, the chloroprene rubber (DuPont Neoprene{sup R} - generic name) possesses a good performance, being one of the most used in the current days. However, this kind of polymer causes a serious environmental problem if it is not reprocessed or recycled. A worldwide method that has been used and that is an important tool in the rubber devulcanization is microwave irradiation at high temperature Elastomer waste may be devulcanized without depolymerization and allows a new vulcanization into a product having physical properties essentially equivalent to the original vulcanized. In this work, the chloroprene samples were irradiated in microwave generator equipment with 2,450 MHz (frequency) and 1,000 W to 3,000 W (power). The properties of samples (according to ASTM standards) were analyzed before and after irradiation. The degraded material after irradiation will be tested for re-use. (author)

  2. Study of properties of chloroprene rubber devulcanizate by radiation in microwave

    International Nuclear Information System (INIS)

    Scagliusi, Sandra R.; Araujo, Sumair G.; Landini, Liliane; Lugao, Ademar B.

    2009-01-01

    Among the vulcanized elastomers, the chloroprene rubber (DuPont Neoprene R - generic name) possesses a good performance, being one of the most used in the current days. However, this kind of polymer causes a serious environmental problem if it is not reprocessed or recycled. A worldwide method that has been used and that is an important tool in the rubber devulcanization is microwave irradiation at high temperature Elastomer waste may be devulcanized without depolymerization and allows a new vulcanization into a product having physical properties essentially equivalent to the original vulcanized. In this work, the chloroprene samples were irradiated in microwave generator equipment with 2,450 MHz (frequency) and 1,000 W to 3,000 W (power). The properties of samples (according to ASTM standards) were analyzed before and after irradiation. The degraded material after irradiation will be tested for re-use. (author)

  3. Biological effects of 2450 MHZ microwave radiation on Raji-Cell in vitro

    International Nuclear Information System (INIS)

    Tan Ming; Zhang Mengdan; Xu Hao.

    1988-01-01

    A water circulating microwave exposure system designed by the authors was used to investigate the thermal and nonthermal biological effects at different power density (1.0mw/cm 2 , 3.9mw/cm 2 , 6.2mw/cm 2 , 8.3mw/cm 2 , 10.5mw/cm 2 ). The results show that the growth of Raji-Cell is inhibited significantly by microwave exposure in 8.3 mw/cm 2 and 10.5 mw/cm 2 groups in temperature controlled test (below 37.0 deg C). It shows that while the growth curve goes down, the rate of inhibition and time of generation increase. The degree of inhibition would increase when the medium temperature was not controlled. And, the mechanisms of thermal and nonthermal biological effects were discussed

  4. Autoacceleration of electron beam and microwave radiation in the diaphragmed waveguide

    International Nuclear Information System (INIS)

    Kolomensky, A.A.; Meskhy, G.O.; Yablokov, B.N.

    1977-01-01

    The energy of a portion of beam electrons can be increased by means of the autoacceleration mechanism. In these experiments, an electron accelerator with parameters 0.5 to 1.0 MeV, 20 to 30 kA, 40 to 50 ns was used. A hollow beam was passed through a diaphragmed waveguide. At its output, the electron spectrum and microwave spectrum were measured simultaneously. About 10% of the electrons increase their energy as compared with the maximum input energy, whereby 3% increase their energy more than by a factor of two. The energy multiplication for the tail electrons turns out to be 3 to 4 times the initial value. About 10% of the beam input power is spent on the increase of electron energy. The pulse microwave power generated is in the range 2.7 to 2.9 GHz and its total measured power was approx. 0.4 GW, which corresponds to approx. 20% of the input beam power. Experiments show that effects of autoacceleration and microwave generation are interdependent and should be studied together

  5. Compton scattering of microwave background radiation by gas in galaxy clusters

    International Nuclear Information System (INIS)

    Gould, R.J.; Rephaeli, Y.

    1978-01-01

    Based on data on the X-ray spectrum of the Coma cluster, interpreted as thermal bremsstrahlung, the expected brightness depletion from Compton scattering of the microwave background in the direction of the cluster is computed. The calculated depletion is about one-third that recently observed by Gull and Northover, and the discrepancy is discussed. In comparing the observed microwave depletion in the direction of other clusters which are X-ray sources it is found that there is no correlation with the cluster X-ray luminosity, while a dependence proportional to L/sub x//sup 1/2/ is expected. Consequently, the microwave depletion observations cannot yet be taken as good evidence for a thermal bremsstrahlung origin for the X-ray emission. The perturbation from Compton scattering of photons on the high-frequency (Wien) tail of the blackbody distribution is computed and found to be much larger than predicted in previous calculations. In the Wien tail the effect is a relative increase in the blackbody intensity that is appreciably greater in magnitude than the depletion in the Rayleigh-Jeans domain

  6. Preliminary test Results for a 25K Sorption Cryocooler Designed for the UCSB Long Duration Balloon Cosmic Microwave Background Radiation Experiment

    Science.gov (United States)

    Wade, L. A.; Levy, A. R.

    1996-01-01

    A continuous operation, vibration-free, long-life 25K sorption cryocooler has been built and is now in final integration and performance testing. This cooler wil be flown on the University of California at Santa Barbara (UCSB) Long Duration Balloon (LDB) Cosmic Microwave Background Radiation Experiment.

  7. Analysis and evaluation of WRF microphysical schemes for deep moist convection over south-eastern South America (SESA) using microwave satellite observations and radiative transfer simulations

    Science.gov (United States)

    Sol Galligani, Victoria; Wang, Die; Alvarez Imaz, Milagros; Salio, Paola; Prigent, Catherine

    2017-10-01

    In the present study, three meteorological events of extreme deep moist convection, characteristic of south-eastern South America, are considered to conduct a systematic evaluation of the microphysical parameterizations available in the Weather Research and Forecasting (WRF) model by undertaking a direct comparison between satellite-based simulated and observed microwave radiances. A research radiative transfer model, the Atmospheric Radiative Transfer Simulator (ARTS), is coupled with the WRF model under three different microphysical parameterizations (WSM6, WDM6 and Thompson schemes). Microwave radiometry has shown a promising ability in the characterization of frozen hydrometeors. At high microwave frequencies, however, frozen hydrometeors significantly scatter radiation, and the relationship between radiation and hydrometeor populations becomes very complex. The main difficulty in microwave remote sensing of frozen hydrometeor characterization is correctly characterizing this scattering signal due to the complex and variable nature of the size, composition and shape of frozen hydrometeors. The present study further aims at improving the understanding of frozen hydrometeor optical properties characteristic of deep moist convection events in south-eastern South America. In the present study, bulk optical properties are computed by integrating the single-scattering properties of the Liu(2008) discrete dipole approximation (DDA) single-scattering database across the particle size distributions parameterized by the different WRF schemes in a consistent manner, introducing the equal mass approach. The equal mass approach consists of describing the optical properties of the WRF snow and graupel hydrometeors with the optical properties of habits in the DDA database whose dimensions might be different (Dmax') but whose mass is conserved. The performance of the radiative transfer simulations is evaluated by comparing the simulations with the available coincident

  8. Influence of a microwave radiation on dissolution kinetics of UO2, CeO2, and Co3O4 in nitric environment

    International Nuclear Information System (INIS)

    Joret, Laurent

    1995-01-01

    This research thesis addresses the issue of dissolution oxides present in spent nuclear fuels. As previous studies outlined important increases of oxide dissolution rate when submitted to microwaves, the issue is then to apply such a technique to PuO 2 which is the most difficult oxide to dissolve. As plutonium may be handled only in certified laboratories and under strict safety conditions, the author studied the influence of a microwave radiation on the dissolution kinetics of other and various metallic oxides in a nitric environment. The choice of this nitric environment is imposed by conditions met in the nuclear industry. Oxides are chosen according to two criteria: dissolution times ranging from few minutes to few days, various responses to electromagnetic radiation (different values for the real and imaginary parts of their dielectric permittivity). Three oxides are retained: UO 2 and CeO 2 (to model PuO 2 ) and Co 3 O 4 . After a recall of some theoretical aspects of the response of a dielectric material to an electromagnetic field, a comparison between conventional and microwave heating, the author presents the main results obtained by using microwaves in chemistry (organic synthesis, ceramic sintering, acid dissolution). He reports the experimental study of nitric dissolution of oxides by conventional heating, and the dielectric characterisation of the studied oxides. He presents the experimental microwave set-up, and reports and discusses experimental results obtained for the dissolution of UO 2 , CeO 2 and Co 3 O 4 in HNO 3 [fr

  9. The diagnosis of the gastric cancer using catheter-type semiconductor radiation detector. Comparison of diagnostic values of. beta. -emitting radionuclide label with. gamma. -emitting label

    Energy Technology Data Exchange (ETDEWEB)

    Sassa, R; Iwase, T [Asahi Life Foundation, Tokyo (Japan). Inst. for Adult Diseases; Sugita, T; Iio, M

    1975-06-01

    The diagnostic usefulness of /sup 32/P-phosphate for human gastric cancer, using a catheter-type semiconductor radiation detector (CASRAD) combined with gastrofiberscope technique, has already been reported by the authors. They have in addition used sup(99m)Tc-bleomycin, sup(99m)Tc-tetracycline in the diagnosis of experimental rabbit gastric cancer, too. In the present study, further refinement of the technique for the ..beta..-ray labeled substance (/sup 32/P-phosphate) for detection of the gastric cancer was compared with that of ..gamma..-ray labeled substance (sup(99m)Tc-tetracycline). A more correct diagnosis of the gastric cancer by in vivo measurement of beta activity could be obtained, when the collimater, made of stainless steel, was attached to the top of the detector. In this way contribution to the count from the adjacent tissues or organs could be eliminated. They were unable to produce an effective and useful collimater for ..gamma..-ray labeled substance which could to be used safely in vivo. Because of the unsatisfactory collimater, radioactivities of the adjacent organs caused on increase in the radioactivity of the background. Therefore inspite of the recent introduction of various sup(99m)Tc-tumor agents, these labels were not applicable to the CASRAD method. For such a small detector system, ..beta..-labels, represented by /sup 32/P-phosphate, was still prefererable to ..gamma..-labels.

  10. A bolometric millimeter-wave system for observations of anisotropy in the cosmic microwave background radiation on medium angular scales

    Science.gov (United States)

    Fischer, M. L.; Alsop, D. C.; Cheng, E. S.; Clapp, A. C.; Cottingham, D. A.; Gundersen, J. O.; Koch, T. C.; Kreysa, E.; Meinhold, P. R.; Lange, A. E.

    1992-01-01

    We report the performance of a bolometric system designed to measure the anisotropy of the cosmic microwave background (CMB) radiation on angular scales from 0 deg 3 min to 3 deg. The system represents a collaborative effort combining a low-background 1 m diameter balloon-borne telescope with new multimode feed optics, a beam modulation mechanism with high stability, and a four-channel bolometric receiver with passbands centered near frequencies of 3 (90), 6 (180), 9 (270), and 12 (360) cm(exp -1) (GHz). The telescope was flown three times with the bolometric receiver and has demonstrated detector noise limited performance capable of reaching sensitivity levels of Delta(T)/T(sub CMB) is approximately equal to 10(exp -5) with detectors operated at T = 0.3 K.

  11. The great wall in the CfA survey: Its origin and imprint on the microwave background radiation

    International Nuclear Information System (INIS)

    Atrio-Barandela, F.; Kashlinsky, A.

    1990-01-01

    The Great Wall (GW) found in the latest CfA survey has clearly started out as an aspherical overdense region. We model its evolution after recombination and the imprint its time-dependent gravitational potential leaves on the microwave background radiation (MBR). We approximate GW as an oblate ellipsoid and show that it started at recombination with an almost spherical shape, but with an initial density contrast, δ i , much smaller than it had to be in the spherical model in order to reach the observed GW density contrast of q∝5. The resultant δ i is compatible with the r.m.s. value of δρ/ρ on the GW scale at recombination for models with the n -6 -5 depending on Ω and q. Therefore, MBR observations in that direction can further constrain Ω and the bias factor of the light distribution. (orig.)

  12. GSM 900 MHz Microwave RadiationInduced Alterations of Insulin Level and Histopathological Changes of Liver and Pancreas in Rat

    Directory of Open Access Journals (Sweden)

    Mortazavi S. M. J.

    2016-12-01

    Full Text Available Background: The rapidly increasing use of mobile phones has led to public concerns about possible health effects of these popular communication devices. This study is an attempt to investigate the effects of radiofrequency (RF radiation produced by GSM mobile phones on the insulin release in rats. Methods: Forty two female adult Sprague Dawley rats were randomly divided into 4 groups. Group1 were exposed to RF radiation 6 hours per day for 7 days. Group 2 received sham exposure (6 hours per day for 7 days. Groups 3 and 4 received RF radiation 3 hours per day for 7 days and sham exposure (3 hours per day, respectively. The specific absorption rate (SAR of RF was 2.0W/kg. Results: Our results showed that RF radiations emitted from mobile phone could not alter insulin release in rats. However, mild to severe inflammatory changes in the portal spaces of the liver of rats as well as damage in the cells of islet of Langerhans were observed. These changes were linked with the duration of the exposures. Conclusion: RF exposure can induce inflammatory changes in the liver as well causing damage in the cells of islet of Langerhans.

  13. Long-term exposure to microwave radiation provokes cancer growth: evidences from radars and mobile communication systems.

    Science.gov (United States)

    Yakymenko, I; Sidorik, E; Kyrylenko, S; Chekhun, V

    2011-06-01

    In this review we discuss alarming epidemiological and experimental data on possible carcinogenic effects of long term exposure to low intensity microwave (MW) radiation. Recently, a number of reports revealed that under certain conditions the irradiation by low intensity MW can substantially induce cancer progression in humans and in animal models. The carcinogenic effect of MW irradiation is typically manifested after long term (up to 10 years and more) exposure. Nevertheless, even a year of operation of a powerful base transmitting station for mobile communication reportedly resulted in a dramatic increase of cancer incidence among population living nearby. In addition, model studies in rodents unveiled a significant increase in carcinogenesis after 17-24 months of MW exposure both in tumor-prone and intact animals. To that, such metabolic changes, as overproduction of reactive oxygen species, 8-hydroxi-2-deoxyguanosine formation, or ornithine decarboxylase activation under exposure to low intensity MW confirm a stress impact of this factor on living cells. We also address the issue of standards for assessment of biological effects of irradiation. It is now becoming increasingly evident that assessment of biological effects of non-ionizing radiation based on physical (thermal) approach used in recommendations of current regulatory bodies, including the International Commission on Non-Ionizing Radiation Protection (ICNIRP) Guidelines, requires urgent reevaluation. We conclude that recent data strongly point to the need for re-elaboration of the current safety limits for non-ionizing radiation using recently obtained knowledge. We also emphasize that the everyday exposure of both occupational and general public to MW radiation should be regulated based on a precautionary principles which imply maximum restriction of excessive exposure.

  14. Discrete curved ray-tracing method for radiative transfer in an absorbing-emitting semitransparent slab with variable spatial refractive index

    International Nuclear Information System (INIS)

    Liu, L.H.

    2004-01-01

    A discrete curved ray-tracing method is developed to analyze the radiative transfer in one-dimensional absorbing-emitting semitransparent slab with variable spatial refractive index. The curved ray trajectory is locally treated as straight line and the complicated and time-consuming computation of ray trajectory is cut down. A problem of radiative equilibrium with linear variable spatial refractive index is taken as an example to examine the accuracy of the proposed method. The temperature distributions are determined by the proposed method and compared with the data in references, which are obtained by other different methods. The results show that the discrete curved ray-tracing method has a good accuracy in solving the radiative transfer in one-dimensional semitransparent slab with variable spatial refractive index

  15. Microwave Breast Imaging Techniques

    DEFF Research Database (Denmark)

    Zhurbenko, Vitaliy; Rubæk, Tonny

    2010-01-01

    This paper outlines the applicability of microwave radiation for breast cancer detection. Microwave imaging systems are categorized based on their hardware architecture. The advantages and disadvantages of various imaging techniques are discussed. The fundamental tradeoffs are indicated between...... various requirements to be fulfilled in the design of an imaging system for breast cancer detection and some strategies to overcome these limitations....

  16. MICROWAVES IN ORGANIC SYNTHESIS

    Science.gov (United States)

    The effect of microwaves, a non-ionizing radiation, on organic reactions is described both in polar solvents and under solvent-free conditions. The special applications are highlighted in the context of solventless organic synthesis which involve microwave (MW) exposure of neat r...

  17. A microwave powered sensor assembly for microwave ovens

    DEFF Research Database (Denmark)

    2016-01-01

    The present invention relates to a microwave powered sensor assembly for micro- wave ovens. The microwave powered sensor assembly comprises a microwave antenna for generating an RF antenna signal in response to microwave radiation at a predetermined excitation frequency. A dc power supply circuit...... of the microwave powered sensor assembly is operatively coupled to the RF antenna signal for extracting energy from the RF antenna signal and produce a power supply voltage. A sensor is connected to the power supply voltage and configured to measure a physical or chemical property of a food item under heating...... in a microwave oven chamber....

  18. Radiation loss of planar surface plasmon polaritons transmission lines at microwave frequencies.

    Science.gov (United States)

    Xu, Zhixia; Li, Shunli; Yin, Xiaoxing; Zhao, Hongxin; Liu, Leilei

    2017-07-21

    Radiation loss of a typical spoof surface plasmon polaritons (SSPPs) transmission line (TL) is investigated in this paper. A 325 mm-long SSPPs TL is designed and fabricated. Simulated results show that radiation loss contributes more to transmission loss than dielectric loss and conductor loss from 2 GHz to 10 GHz. Radiation loss of the SSPPs TL could be divided into two parts, one is caused by the input mode converter, and the other is caused by the corrugated metallic strip. This paper explains mechanisms of radiation loss from different parts, designs a loaded SSPPs TL with a series of resistors to absorb electromagnetic energy on corrugated metallic strip, and then discriminates radiation loss from the input mode converter, proposes the concept of average radiation length (ARL) to evaluate radiation loss from SSPPs of finite length, and concludes that radiation loss is mainly caused by corrugated structure of finite length at low frequency band and by the input mode converter at high frequency band. To suppress radiation loss, a mixed slow wave TL based on the combination of coplanar waveguides (CPWs) and SSPPs is presented. The designed structure, sample fabrication and experimental verification are discussed.

  19. Response of exfoliated human buccal epithelium cells to combined gamma radiation, microwaves, and magnetic field exposure estimated by changes in chromatin condensation and cell membrane permeability

    Directory of Open Access Journals (Sweden)

    K. А. Kuznetsov

    2016-11-01

    Full Text Available Modulation of the biological effects produced by ionizing radiation (IR using microwave and magnetic fields has important theoretical and practical applications. Response of human buccal epithelium cells to different physical agents (single and combined exposure to 0.5–5 Gy γ-radiation (60Co; microwaves with the frequency of 36.64 GHz and power densities of 0.1 and 1 W/m2, and static magnetic field with the intensity of 25 mT has been investigated. The stress response of the cells was evaluated by counting heterochromatin granules quantity (HGQ in the cell nuclei stained with orcein. Membrane permeability was assessed by the percentage of cells stained with indigocarmine (cells with damaged membrane. The increase of heterochromatin granules quantity (HGQ, i.e. chromatin condensation was detected at the doses of 2 Gy and higher. Changes in the cell membrane permeability to indigocarmine expressed the threshold effect. Membrane permeability reached the threshold at the doses of 2–3 Gy for the cells of different donors and did not change with the increase of the dose of γ-radiation. Cells obtained from different donors revealed some individual peculiarities in their reaction to γ-radiation. The static magnetic field and microwaves applied before or after γ-radiation decreased its impact, as revealed by means of HGQ assessment.

  20. An explanation of efficiency droop in InGaN-based light emitting diodes: saturated radiative recombination rate at randomly distributed In-rich active areas

    International Nuclear Information System (INIS)

    Shim, Jong-In; Kim, Hyun-Sung; Shin, Dong-Soo; Yoo, Han-Youl

    2011-01-01

    We present a comprehensive model of the dependence of the internal quantum efficiency (IQE) on both the temperature and the carrier density in InGaN-based blue and green light emitting diodes (LEDs). In our model, carriers are dominantly located and recombine both radiatively and nonradiatively inside randomly distributed In-rich areas of the InGaN quantum wells (QWs). In those areas, the carrier density is very high even at a small current density. We propose that the saturated radiative recombination rate is a primary factor determining the IQE droop of InGaN based LEDs. In typical InGaN-based QWs, it is common for the total carrier recombination rate to be smaller than the carrier injection rate even at a small current density. This is mostly attributable to the saturation of the radiative recombination rate. The saturation of the radiative recombination rate increases carrier density in InGaN QWs, enlarges nonradiative carrier losses, and eventually gives rise to the large IQE droop with increasing current. We show how the radiative recombination rate saturates and the radiative recombination rate has influence on the IQE droop in InGaN-based QW LEDs.

  1. Design of a microwave calorimeter for the microwave tokamak experiment

    International Nuclear Information System (INIS)

    Marinak, M.

    1988-01-01

    The initial design of a microwave calorimeter for the Microwave Tokamak Experiment is presented. The design is optimized to measure the refraction and absorption of millimeter rf microwaves as they traverse the toroidal plasma of the Alcator C tokamak. Techniques utilized can be adapted for use in measuring high intensity pulsed output from a microwave device in an environment of ultra high vacuum, intense fields of ionizing and non-ionizing radiation and intense magnetic fields. 16 refs

  2. Impact of electromagnetic radiation emitted by monitors on changes in the cellular membrane structure and protective antioxidant effect of vitamin A - In vitro study.

    Science.gov (United States)

    Lewicka, Małgorzata; Henrykowska, Gabriela; Zawadzka, Magdalena; Rutkowski, Maciej; Pacholski, Krzysztof; Buczyński, Andrzej

    2017-07-14

    The increasing number of devices emitting electromagnetic radiation (EMR) in people's everyday life attracted the attention of researchers because of possible adverse effects of this factor on living organisms. One of the EMR effect may be peroxidation of lipid membranes formed as a result of free radical process. The article presents the results of in vitro studies aimed at identifying changes in malondialdehyde (MDA) concentration - a marker of lipid peroxidation and antioxidant role of vitamin A during the exposure of blood platelets to electromagnetic radiation generated by liquid-crystal-display (LCD) monitors. Electromagnetic radiation emitted by LCD monitors is characterized by parameters: 1 kHz frequency and 220 V/m intensity (15 cm from display screen). The time of exposure was 30 and 60 min. The study was conducted on porcine blood platelets. The samples were divided into 6 groups: unexposed to radiation, unexposed + vitamin A, exposed for 30 min, exposed for 30 min + vitamin A, exposed for 60 min, exposed for 60 min + vitamin A. The MDA concentration in blood platelets increases significantly as compared to control values after 60 min of exposure to EMR. A significant decrease in MDA concentration after the addition of vitamin A was noticed. In the blood samples exposed to EMR for 30 and 60 min the MDA concentration was significantly increased by addition of vitamin A. The results show the possibly negative effect of electromagnetic radiation on the cellular membrane structure manifested by changes in malondialdehyde concentration and indicate a possible protective role of vitamin A in this process. Int J Occup Med Environ Health 2017;30(5):695-703. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  3. GARLIC - A general purpose atmospheric radiative transfer line-by-line infrared-microwave code: Implementation and evaluation

    Science.gov (United States)

    Schreier, Franz; Gimeno García, Sebastián; Hedelt, Pascal; Hess, Michael; Mendrok, Jana; Vasquez, Mayte; Xu, Jian

    2014-04-01

    A suite of programs for high resolution infrared-microwave atmospheric radiative transfer modeling has been developed with emphasis on efficient and reliable numerical algorithms and a modular approach appropriate for simulation and/or retrieval in a variety of applications. The Generic Atmospheric Radiation Line-by-line Infrared Code - GARLIC - is suitable for arbitrary observation geometry, instrumental field-of-view, and line shape. The core of GARLIC's subroutines constitutes the basis of forward models used to implement inversion codes to retrieve atmospheric state parameters from limb and nadir sounding instruments. This paper briefly introduces the physical and mathematical basics of GARLIC and its descendants and continues with an in-depth presentation of various implementation aspects: An optimized Voigt function algorithm combined with a two-grid approach is used to accelerate the line-by-line modeling of molecular cross sections; various quadrature methods are implemented to evaluate the Schwarzschild and Beer integrals; and Jacobians, i.e. derivatives with respect to the unknowns of the atmospheric inverse problem, are implemented by means of automatic differentiation. For an assessment of GARLIC's performance, a comparison of the quadrature methods for solution of the path integral is provided. Verification and validation are demonstrated using intercomparisons with other line-by-line codes and comparisons of synthetic spectra with spectra observed on Earth and from Venus.

  4. Studies of the teratogenic potential of exposure of rats to 6000-MHz microwave radiation. II. Postnatal psychophysiologic evaluations

    International Nuclear Information System (INIS)

    Jensh, R.P.

    1984-01-01

    Wistar rats (36) were exposed daily throughout pregnancy to a power density level of 35 mW/cm 2 of 6000-MHz microwave radiation (11), sham irradiated (10), or used as control animals (15). Litters were culled to a maximum of eight F 1 /sub a/ offspring/litter (total = 124) on Postnatal Day 1 and subjected to a series of reflex tests beginning Day 3. Mothers were rebred 10 days after weaning. Teratologic evaluations were completed on 263 F 1 /sub b/ offspring. Weekly weights were recorded for 298 F 1 /sub a/ offspring. At 60 days, behavioral testing was initiated on 121 offspring. At 90 days, offspring were bred within/across groups. Teratologic evaluations were completed on 659 F 2 term fetuses. Organ weight analyses were completed on 17 mothers and 181 F 1 /sub a/ adult offspring, and blood analyses on 21 mothers and 131 offspring. Sex differences within groups were observed in four behavioral tests and in blood data. Significant differences between groups were observed for: F 1 /sub b/ term fetal weight; F 1 /sub a/ eye opening, postnatal growth to the fifth week, water T-maze and open field test results; and several organ/body weight ratios. These results indicate that exposure to 6000-MHz radiation at this power density level may result in subtle long-term neurophysiologic alterations not detectable at term using conventional morphologic teratologic procedures

  5. Studies of the teratogenic potential of exposure of rats to 6000-MHz microwave radiation. II. Postnatal phychophysiologic evaluations

    International Nuclear Information System (INIS)

    Jensh, R.P.

    1984-01-01

    Wistar rats (36) were exposed daily throughout pregnancy to a power density level of 35 mW/cm 2 of 6000-MHz microwave radiation (11), sham irradiated (10), or used as control animals (15). Litters were culled to a maximum of eight F 1 /sub a/ offspring/litter (total = 124) on Postnatal Day 1 and subjected to a series of reflex tests beginning Day 3. Mothers were rebred 10 days after weaning. Teratologic evaluations were completed on 263 F 1 /sub b/ offspring. Weekly weights were recorded for 298 F 1 /sub a/ offspring. At 60 days, behavioral testing was initiated on 121 offspring. At 90 days, offspring were bred within/across groups. Teratologic evaluations were completed on 659 F 2 term fetuses. Organ weight analyses were completed on 17 mothers and 181 F 1 /sub a/ adult offspring, and blood analyses on 21 mothers and 131 offspring. Sex differences within groups were observed in four behavioral tests and in blood data. Significant differences between groups were observed for: F 1 /sub b/ term fetal weight; F 1 /sub a/ eye opening, postnatal growth to the fifth week, water T-maze and open field test results; and several organ/body weight ratios. These results indicate that exposure to 6000-MHz radiation at this power density level may result in subtle long-term neurophysiologic alterations not detectable at term using conventional morphologic teratologic procedures

  6. Oscillator phenomena in the solar atmosphere and radiation modulation in microwaves

    International Nuclear Information System (INIS)

    Vaz, A.M.Z.

    1983-05-01

    An overview of the principal known descriptions of oscillations in the solar atmosphere at different ranges of periods was developed. Particular attention was given to oscillations with time scale of seconds, associated to active regions or bursts. 1.5 quasi-periodic oscillations were detected by the first time at more than one microwave frequency simultaneously (22 GHz and 44 GHz), with high sensitivity and high time resolution, superimposed on a burst on Dec. 15, 1980. An advance phase of 0,3s between the oscillations in the frequencies of 22 GHz and 44 GHz was discovered. The proposed mechanism to explain such oscillations is based on oscillations of the magnetic field at the source. These oscillations modulate the gyro-synchrotron emission from high energy electrons trapped in the magnetic structure. The phase difference is attributed to the influence of the optical thickness of the gyro-synchrotron emission at 22 GHz. (Author) [pt

  7. Sources of exposure to radiofrequency and microwave radiations in the UK

    CERN Document Server

    Allen, S G

    1983-01-01

    A comprehensive survey is presented of sources of radiofrequency and microwave fields in the United Kingdom that give rise to the exposure of both workers and the general public. The information is presented in the context of the existing guidelines for the restrictions of exposures to such fields and of proposed new guidelines based on restricting the rate of energy absorption averaged over the human body to 0.4 watts per kilogram or, at frequencies below 3 MHz, limiting field strengths to 600 volts per metre. It is concluded that unless account is taken of time averaging relaxations and possible modifying factors relating to energy absorption arising under near field and partial body exposure conditions, there may be difficulties in applying the proposed guidelines to the use of radio frequencies for industrial heating purposes and to some portable and mobile transmitters used for communications.

  8. Isotropic blackbody cosmic microwave background radiation as evidence for a homogeneous universe.

    Science.gov (United States)

    Clifton, Timothy; Clarkson, Chris; Bull, Philip

    2012-08-03

    The question of whether the Universe is spatially homogeneous and isotropic on the largest scales is of fundamental importance to cosmology but has not yet been answered decisively. Surprisingly, neither an isotropic primary cosmic microwave background (CMB) nor combined observations of luminosity distances and galaxy number counts are sufficient to establish such a result. The inclusion of the Sunyaev-Zel'dovich effect in CMB observations, however, dramatically improves this situation. We show that even a solitary observer who sees an isotropic blackbody CMB can conclude that the Universe is homogeneous and isotropic in their causal past when the Sunyaev-Zel'dovich effect is present. Critically, however, the CMB must either be viewed for an extended period of time, or CMB photons that have scattered more than once must be detected. This result provides a theoretical underpinning for testing the cosmological principle with observations of the CMB alone.

  9. Dielectric and magnetic losses of microwave electromagnetic radiation in granular structures with ferromagnetic nanoparticles

    CERN Document Server

    Lutsev, L V; Tchmutin, I A; Ryvkina, N G; Kalinin, Y E; Sitnikoff, A V

    2003-01-01

    We have studied dielectric and magnetic losses in granular structures constituted by ferromagnetic nanoparticles (Co, Fe, B) in an insulating amorphous a-SiO sub 2 matrix at microwave frequencies, in relation to metal concentration, substrate temperatures and gas content, in the plasma atmosphere in sputtering and annealing. The magnetic losses are due to fast spin relaxation of nanoparticles, which becomes more pronounced with decreasing metal content and occur via simultaneous changes in the granule spin direction and spin polarization of electrons on exchange-split localized states in the matrix (spin-polarized relaxation mechanism). The difference between the experimental values of the imaginary parts of magnetic permeability for granular structures prepared in Ar and Ar + O sub 2 atmospheres is determined by different electron structures of argon and oxygen impurities in the matrix. To account for large dielectric losses in granular structures, we have developed a model of cluster electron states (CESs)....

  10. Hospital waste sterilization: a technical and economic comparison between radiation and microwave treatments

    International Nuclear Information System (INIS)

    Tata, A.; Beone, F.

    1995-01-01

    Hospital waste (HW) disposal is becoming a problem of increasing importance in almost all industrially advanced countries. In Italy the yearly hospital waste production is about 250,000 tons and only 60,000 are treated by incineration at present time. As by a recent Italian law a meaningful percentage of HW (50 to 60%), corresponding to food residuals, plastic, paper, various organic materials, etc., could be landfilled as municipal refuses if preliminarily submitted to a suitable sterilization treatment. Under this perspective, sterilization/sanitation techniques represent now a technically and commercially viable alternative to HW thermal destruction that, besides more and more socially and politically less accepted. Electron Beam (EB) and Microwave (MW) treatments are two of the most interesting and emerging HW sterilization techniques, and, based on engineering real data, a technical and economic comparison is carried out, focusing vantages and limits of each process. (author)

  11. Degradation of Transformer Oil (PCB Compounds by Microwave Radiation, Ethanol Solvent, Hydrogen Peroxide and Dioxide Titanium for Reducing Environmental Hazards

    Directory of Open Access Journals (Sweden)

    Reza Tajik

    2013-02-01

    Full Text Available Background: Poly chlorinated biphenyls (PCBs are a class of chlorinated organic chemicals that do not easily degrade in the environment. This study was conducted to determine the effect of microwave rays, hydrogen peroxide, dioxide titanium and ethanol solvent on the degradation of PCBs. Methods: A 900w domestic MW oven with a fixed frequency of 2450 MHZ was used to provide MW irradiation. Ray powers were used in 540, 720, and 900w. A hole was made on the top portion of the oven and a Pyrex vessel reactor (250ml volume was connected to condensing system with a Pyrex tube connector. The PCBs were analyzed by GC-ECD. Results: The degradation of total PCBs was 54.62%, 79.71%, and 95.76% in terms of their ratio to solvent with transformer oil at 1:1, 2:1, and 3:1, respectively. The degradation of total PCBs was 84.27%, 89.18%, and 96.1% when using 540, 720, and 900W microwave radiation, respectively. The degradation of total PCBs was 70.72%, 93.02%, 94.16, 95.23% and 96.1% when not using H2O2/ Tio2 and using 20% H2O2 and 0.05, 0.1, 0.15, and 0.2g Tio2, respectively. Conclusion: In the present study, the optimum conditions to decompose PCBs efficiently included 50 ml volume of ratio to solvent with transformer oil (3:1, sodium hydroxide solution (0.2N 1 cc, use of 20% hydrogen peroxide of total volume of samples, dioxide titanium (0.2g, and irradiation for 9 minutes. Under these optimum conditions, efficiency of PCBs decomposition increased.

  12. Diminution of acute radiation reaction of mouse skin with low-intensity infrared laser/red diodes-emitted light

    International Nuclear Information System (INIS)

    Meshcherikova, V.V.; Klimakov, B.D.; Goldobenko, G.V.; Vajnson, A.A.

    2000-01-01

    Efficiency of the application of different regimes of laser treatment of radiation-induced skin reactions in mice feet is compared. Posterior limb feet of mice were exposed to acute X radiation at 30-36 Gy dose or fractionated radiation at 45 Gy dose. In the day of primary irradiation or different time later the feet were treated using magnetic infrared laser therapeutic MILTA-01 apparatus. Magnetic and light components of the MILTA-01 apparatus reduce the effect of radiation on mice skin corresponding two time decrease in X-radiation dose [ru

  13. Microwave radiation effects on the different stages of Sitophilus oryzae (Linne, 1763) (Coleoptera, Curculionidae) evolutive cycle in rice, focusing its control

    International Nuclear Information System (INIS)

    Franco, Jose G.; Franco, Suely S.H.; Franco, Caio H.; Arthur, Paula B.; Arthur, Valter

    2013-01-01

    As insects increase in radio tolerance as they develop and usually several developmental stages of pest may present in grain shipped commodity, it is important to know the microwave radiation susceptibility of stages of the target insect before the establishment of microwave radiation quarantine treatments. The current research had the aim to evaluate the microwave radiation effects on several phases of the rice weevil evolution cycle (S.oryzae), focusing its control. This specie is considered as on of the most serious worldwide pests for stored grains. The tests have been done in glass vials with 250 grams of whole grain (brown) rice and the irradiation was done in a 2,450 MHz commercial microwave oven, model Carousel II (potency of 800W). It was determined the exposure time needed to each phase control for the insect evolutive cycle, concluding that the immature phases (larvae and pupae), contained inside the rice, are more sensitive, requiring only 100 seconds to obtain 100% control while the egg phase requires a longer exposure (130 seconds). Referring to the grown phase, the time required to attain the lethal dose was 160 seconds. All the exposure time have been irradiated with a low potency (240 W). It also displayed that to greater quantities of rice (1.0 kg), with egg presence and forming a 2.0-centimeter layer on the microwave plate surface, it required an exposure time of 180 seconds. Therefore, in a more effective way, we can recommend these 180 seconds exposure time to the control of all phases concerning the insect evolutive cycle. (author)

  14. Microwave radiation effects on the different stages of Sitophilus oryzae (Linne, 1763) (Coleoptera, Curculionidae) evolutive cycle in rice, focusing its control

    Energy Technology Data Exchange (ETDEWEB)

    Franco, Jose G.; Franco, Suely S.H., E-mail: gilmita@uol.com.br, E-mail: zegilmar60@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Franco, Caio H.; Arthur, Paula B.; Arthur, Valter, E-mail: caiohaddadfranco@lnbio.cnpem.com.br, E-mail: arthur@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil). Lab. de Radiobiologia e Ambiente

    2013-07-01

    As insects increase in radio tolerance as they develop and usually several developmental stages of pest may present in grain shipped commodity, it is important to know the microwave radiation susceptibility of stages of the target insect before the establishment of microwave radiation quarantine treatments. The current research had the aim to evaluate the microwave radiation effects on several phases of the rice weevil evolution cycle (S.oryzae), focusing its control. This specie is considered as on of the most serious worldwide pests for stored grains. The tests have been done in glass vials with 250 grams of whole grain (brown) rice and the irradiation was done in a 2,450 MHz commercial microwave oven, model Carousel II (potency of 800W). It was determined the exposure time needed to each phase control for the insect evolutive cycle, concluding that the immature phases (larvae and pupae), contained inside the rice, are more sensitive, requiring only 100 seconds to obtain 100% control while the egg phase requires a longer exposure (130 seconds). Referring to the grown phase, the time required to attain the lethal dose was 160 seconds. All the exposure time have been irradiated with a low potency (240 W). It also displayed that to greater quantities of rice (1.0 kg), with egg presence and forming a 2.0-centimeter layer on the microwave plate surface, it required an exposure time of 180 seconds. Therefore, in a more effective way, we can recommend these 180 seconds exposure time to the control of all phases concerning the insect evolutive cycle. (author)

  15. Effect of Radiofrequency Radiation Emitted from 2G and 3G Cell Phone on Developing Liver of Chick Embryo - A Comparative Study.

    Science.gov (United States)

    D'Silva, Mary Hydrina; Swer, Rijied Thompson; Anbalagan, J; Rajesh, Bhargavan

    2017-07-01

    The increasing scientific evidence of various health hazards on exposure of Radiofrequency Radiation (RFR) emitted from both the cell phones and base stations have caused significant media attention and public discussion in recent years. The mechanism of interaction of RF fields with developing tissues of children and fetuses may be different from that of adults due to their smaller physical size and variation in tissue electromagnetic properties. The present study may provide an insight into the basic mechanisms by which RF fields interact with developing tissues in an embryo. To evaluate the possible tissue and DNA damage in developing liver of chick embryo following chronic exposure to Ultra-High Frequency/Radiofrequency Radiation (UHF/RFR) emitted from 2G and 3G cell phone. Fertilized chick embryos were incubated in four groups. Group A-experimental group exposed to 2G radiation (60 eggs), Group B- experimental group exposed to 3G radiation (60 eggs), Group C- sham exposed control group (60 eggs) and Group D- control group (48 eggs). On completion of scheduled duration, the embryos were collected and processed for routine histological studies to check structural changes in liver. The nuclear diameter and karyorrhexis changes of hepatocytes were analysed using oculometer and square reticule respectively. The liver procured from one batch of eggs from all the four groups was subjected to alkaline comet assay technique to assess DNA damage. The results were compared using one-way ANOVA test. In our study, the exposure of developing chick embryos to 2G and 3G cell phone radiations caused structural changes in liver in the form of dilated sinusoidal spaces with haemorrhage, increased vacuolations in cytoplasm, increased nuclear diameter and karyorrhexis and significantly increased DNA damage. The chronic exposure of chick embryo liver to RFR emitted from 2G and 3G cell phone resulted in various structural changes and DNA damage. The changes were more pronounced in 3

  16. Effect of Radiofrequency Radiation Emitted from 2G and 3G Cell Phone on Developing Liver of Chick Embryo – A Comparative Study

    Science.gov (United States)

    Swer, Rijied Thompson; Anbalagan, J.; Rajesh, Bhargavan

    2017-01-01

    Introduction The increasing scientific evidence of various health hazards on exposure of Radiofrequency Radiation (RFR) emitted from both the cell phones and base stations have caused significant media attention and public discussion in recent years. The mechanism of interaction of RF fields with developing tissues of children and fetuses may be different from that of adults due to their smaller physical size and variation in tissue electromagnetic properties. The present study may provide an insight into the basic mechanisms by which RF fields interact with developing tissues in an embryo. Aim To evaluate the possible tissue and DNA damage in developing liver of chick embryo following chronic exposure to Ultra-High Frequency/Radiofrequency Radiation (UHF/RFR) emitted from 2G and 3G cell phone. Materials and Methods Fertilized chick embryos were incubated in four groups. Group A-experimental group exposed to 2G radiation (60 eggs), Group B- experimental group exposed to 3G radiation (60 eggs), Group C- sham exposed control group (60 eggs) and Group D– control group (48 eggs). On completion of scheduled duration, the embryos were collected and processed for routine histological studies to check structural changes in liver. The nuclear diameter and karyorrhexis changes of hepatocytes were analysed using oculometer and square reticule respectively. The liver procured from one batch of eggs from all the four groups was subjected to alkaline comet assay technique to assess DNA damage. The results were compared using one-way ANOVA test. Results In our study, the exposure of developing chick embryos to 2G and 3G cell phone radiations caused structural changes in liver in the form of dilated sinusoidal spaces with haemorrhage, increased vacuolations in cytoplasm, increased nuclear diameter and karyorrhexis and significantly increased DNA damage. Conclusion The chronic exposure of chick embryo liver to RFR emitted from 2G and 3G cell phone resulted in various structural

  17. Integrated Advanced Microwave Sounding Unit-A (AMSU-A). Engineering Test Report: Radiated Emissions and SARR, SARP, DCS Receivers, Link Frequencies EMI Sensitive Band Test Results, AMSU-A1, S/N 108 2

    Science.gov (United States)

    Valdez, A.

    2000-01-01

    This is the Engineering Test Report, Radiated Emissions and SARR, SARP, DCS Receivers, Link Frequencies EMI Sensitive Band Test Results, AMSU-A1 SIN 108, for the Integrated Advanced Microwave Sounding Unit-A (AMSU-A).

  18. Integrated Advanced Microwave Sounding Unit-A (AMSU-A). Engineering Test Report: Radiated Emissions and SARR, SARP, DCS Receivers, Link Frequencies EMI Sensitive Band Test Results, AMSU-A1, S/N 109

    Science.gov (United States)

    Valdez, A.

    2000-01-01

    This is the Engineering Test Report, Radiated Emissions and SARR, SARP, DCS Receivers, Link Frequencies EMI Sensitive Band Test Results, AMSU-A1, S/N 109, for the Integrated Advanced Microwave Sounding Unit-A (AMSU-A).

  19. Integrated Advanced Microwave Sounding Unit-A (AMSU-A). Engineering Test Report: Radiated Emissions and SARR, SARP, DCS Receivers, Link Frequencies EMI Sensitive Band Test Results, AMSU-A2, S/N 108, 08

    Science.gov (United States)

    Valdez, A.

    2000-01-01

    This is the Engineering Test Report, Radiated Emissions and SARR, SARP, DCS Receivers, Link Frequencies EMI Sensitive Band Test Results, AMSU-A2, S/N 108, for the Integrated Advanced Microwave Sounding Unit-A (AMSU-A).

  20. Survey of the Effects of Exposure to 900 MHz Radiofrequency Radiation Emitted by a GSM Mobile Phone on the Pattern of Muscle Contractions in an Animal Model

    Directory of Open Access Journals (Sweden)

    Mortazavi S. M. J.

    2015-09-01

    Full Text Available Background: The rapid development of wireless telecommunication technologies over the past decades, has led to significant changes in the exposure of the general public to electromagnetic fields. Nowadays, people are continuously exposed to different sources of electromagnetic fields such as mobile phones, mobile base stations, cordless phones, Wi-Fi routers, and power lines. Therefore, the last decade witnessed a rapidly growing concern about the possible health effects of exposure to electromagnetic fields emitted by these sources. Materials and Methods: In this study that was aimed at investigating the effects of exposure to radiofrequency (RF radiation emitted by a GSM mobile phone on the pattern of contraction in frog’s isolated gastrocnemius muscle after stimulation with single square pulses of 1V (1 Hz, pulse height of contractions, the time interval between two subsequent contractions and the latency period were measured. Results: Our findings showed that the pulse height of contractions muscle could be affected by the exposure to electromagnetic fields. Especially, the latency period was effectively altered in RF-exposed samples. However, none of the experiments could show an alteration in the time interval between two subsequent contractions after exposure to electromagnetic fields. Conclusion: These findings support early reports which indicated a wide variety of non-thermal effects of electromagnetic radiation on amphibians including the effects on the pattern of muscle extractions

  1. Survey of the Effects of Exposure to 900 MHz Radiofrequency Radiation Emitted by a GSM Mobile Phone on the Pattern of Muscle Contractions in an Animal Model.

    Science.gov (United States)

    Mortazavi, S M J; Rahimi, S; Talebi, A; Soleimani, A; Rafati, A

    2015-09-01

    The rapid development of wireless telecommunication technologies over the past decades, has led to significant changes in the exposure of the general public to electromagnetic fields. Nowadays, people are continuously exposed to different sources of electromagnetic fields such as mobile phones, mobile base stations, cordless phones, Wi-Fi routers, and power lines. Therefore, the last decade witnessed a rapidly growing concern about the possible health effects of exposure to electromagnetic fields emitted by these sources. In this study that was aimed at investigating the effects of exposure to radiofrequency (RF) radiation emitted by a GSM mobile phone on the pattern of contraction in frog's isolated gastrocnemius muscle after stimulation with single square pulses of 1V (1 Hz), pulse height of contractions, the time interval between two subsequent contractions and the latency period were measured. Our findings showed that the pulse height of contractions muscle could be affected by the exposure to electromagnetic fields. Especially, the latency period was effectively altered in RF-exposed samples. However, none of the experiments could show an alteration in the time interval between two subsequent contractions after exposure to electromagnetic fields. These findings support early reports which indicated a wide variety of non-thermal effects of electromagnetic radiation on amphibians including the effects on the pattern of muscle extractions.

  2. Development of computational pregnant female and fetus models and assessment of radiation dose from positron-emitting tracers

    DEFF Research Database (Denmark)

    Xie, Tianwu; Zaidi, H.

    2016-01-01

    /fetus presents a high sensitivity to ionizing radiation. Therefore, estimation of the radiation dose delivered to the embryo/fetus and pregnant patients from PET examinations to assess potential radiation risks is highly praised. Methods: We constructed eight embryo/fetus models at various gestation periods......Purpose: Molecular imaging using PET and hybrid (PET/CT and PET/MR) modalities nowadays plays a pivotal role in the clinical setting for diagnosis and staging, treatment response monitoring, and radiation therapy treatment planning of a wide range of oncologic malignancies. The developing embryo...

  3. Genotoxicity and oxidative stress of microwave radiation role of ascorbic acid

    International Nuclear Information System (INIS)

    Desouky, O.S.; Abdel Karim, M.A.; Deiaa El Deen, D.A.; Nayal, N.A.

    2005-01-01

    Radiofrequency fields and especially microwaves are very important part of electromagnetic spectrum that can produce generations of reactive oxygen species, and thus can affect DNA and cause chromosomal aberrations. So this effect can be diminished by the supplement of an antioxidant such as ascorbic acid. In this study, the proposed protective role of ascorbic acid was tested against the EMF induced chromosomal aberrations and lipid peroxidation. The present study proved that EMF had a clastogenic effect on the bone marrow cells of mice, either with the exposure to EMF; 950 MHz or frequency EMF; 2450 MHz. This effect was evidenced by structural and numerical chromosomal aberrations. The study also proved that EMF had an effect on oxidative stress, evidenced by increase in the level of lipid peroxide, in a dose dependent manner. So, the mechanism of EMF induced chromosomal aberrations can be explained by this oxidative stress induced by EMF exposure. The present study showed that ascorbic acid had a protective effect against both EMF induced chromosomal aberrations and oxidative stress, when it is applied concomitantly with EMF exposure either at frequency of 950 MHz or 2450 MHz. this is evident by decreases in the level of lipid peroxide and decrease in chromosomal aberrations

  4. Flexible composite via rapid titania coating by microwave-assisted ...

    Indian Academy of Sciences (India)

    2017-06-09

    Jun 9, 2017 ... carbon fibre via microwave-assisted hydrothermal synthesis (MHS) ... Nanoparticles; titanium dioxide; microwave-assisted hydrothermal synthesis; carbon fibre. ..... study, the carbon fibre absorbs microwave radiation and con-.

  5. Features of transformation of impurity-defect complexes in СdTe:Сl under the influence of microwave radiation

    Directory of Open Access Journals (Sweden)

    Budzulyak S. I.

    2014-08-01

    Full Text Available High-resistance cadmium telluride single crystals are promising material for production of ionizing radiation detectors. To increase crystal resistance, they are doped with chlorine. The detector quality depends on uniformity of chlorine impurity distribution over crystal. It is known that low-dose microwave irradiation can homogenize impurity distribution in a specimen. In the present work, we made an attempt to improve the detector material quality by using such post-technological treatment, as well as to study state variation for impurity-defect complexes. To this end, the effect of microwave irradiation on transformation of impurity-defect complexes in CdTe:Cl single crystals was investigated using low-temperature photoluminescence. It is shown that activation of ClTe donor centers by microwave irradiation for 10 s and presence of VCd acceptor centers in the specimens under investigation effectively facilitate formation of (VNd–ClTe defect centers at which excitons are bound. Detailed investigations of the band form for donor-acceptor pairs (DAPs in CdTe:Cl single crystals made it possible to determine the Huang—Rhys factor (that characterizes electron-phonon interaction in CdTe:Cl DAPs as a function of microwave treatment duration. It is shown for single crystals with NCl = 5·1017 cm–3 and 5·1019 cm–3 that the Huang—Rhys factor grows with microwave irradiation dose. This is related to both homogenization of donor and acceptor centers distribution and increase of donor—acceptor spacing. It is shown that microwave irradiation of CdTe:Cl single crystals results in concentration reduction for separate cadmium vacancies VCd because of formation of (VNd—ClTe defect centers at which excitons are bound.

  6. The Effect of Solvent, Hydrogen Peroxide and Dioxide Titanium on Degradation of PCBs, Using Microwave Radiation in Order to Reduce Occupational Exposure

    Directory of Open Access Journals (Sweden)

    Tajik Reza

    2014-07-01

    Full Text Available Polychlorinated biphenyls (PCBs are one group of persistent organic pollutants (POPs that are of international concern because of global distribution, persistence, and toxicity. Removal of these compounds from the environment remains a very difficult challenge because the compounds are highly hydrophobic and have very low solubility in water. A 900 W domestic microwave oven, pyrex vessel reactor, pyrex tube connector and condensing system were used in this experiment. Radiation was discontinuous and ray powers were 540, 720 and 900 W. The PCBS were analyzed by GC-ECD. The application of microwave radiation and H2O2/TiO2 agents for the degradation of polychlorinated biphenyl contaminated oil was explored in this study. PCB – contaminated oil was treated in a pyrex reactor by microwave irradiation at 2450 MHz with the addition of H2O2/TiO2. A novel grain TiO2 (GT01 was used. The determination of PCB residues in oil by gas chromatography (GC revealed that rates of PCB decomposition were highly dependent on microwave power, exposure time, ratio to solvent with transformer oil in 3:1, the optimal amount of GT01 (0.2 g and 0.116 mol of H2O2 were used in the study. It was suggested that microwave irradiation with the assistance of H2O2/TiO2 might be a potential technology for the degradation of PCB – contaminated oil. The experiments show that MW irradiation, H2O2 oxidant and TiO2 catalyst lead to a degradation efficiency of PCBs only in the presence of ethanol. The results showed that the addition of ethanol significantly enhanced degradation efficiency of PCBs.

  7. Studies of the teratogenic potential of exposure of rats to 6000-MHz microwave radiation. I. Morphologic analysis at term

    International Nuclear Information System (INIS)

    Jensh, R.P.

    1984-01-01

    Thirty-six pregnant Wistar strain albino rats were exposed throughout pregnancy to 6000-MHz microwave radiation at a power density level of 35 mW/cm 2 or were used as controls. The irradiation did not cause a significant increase in maternal body temperature as measured by a rectal thermocouple. The rats were randomly assigned to one of four groups: home cage control (5), anechoic chamber control (10), sham-irradiated concurrent control (10), and irradiated (11). All animals were killed on the 22nd day of gestation, and maternal tissues were removed and weighed and maternal blood samples were taken. The 384 resultant fetuses and their placentas were individually weighed, fixed, and dissected to determine normality. Teratologic evaluation included the following parameters: maternal weight and weight gain; mean litter size; maternal organ weight and organ weight/body weight ratios; body weight ratios of brain, liver, kidneys, and ovaries; maternal peripheral blood parameters including hematocrit, hemoglobin, and white cell counts; number of resorptions and resorption rate; number of abnormalities and abnormality rate; mean term fetal weight. The irradiated fetuses exhibited slight but statistically significant growth retardation at term. Term maternal monocyte count was also significantly depressed. No other parameters differed between the control groups and the irradiated group

  8. Microwave Ovens

    Science.gov (United States)

    ... Products and Procedures Home, Business, and Entertainment Products Microwave Ovens Share Tweet Linkedin Pin it More sharing ... 1030.10 - Microwave Ovens Required Reports for the Microwave Oven Manufacturers or Industry Exemption from Certain Reporting ...

  9. Modeling of microwave heating of metallic powders

    International Nuclear Information System (INIS)

    Buchelnikov, V.D.; Louzguine-Luzgin, D.V.; Anzulevich, A.P.; Bychkov, I.V.; Yoshikawa, N.; Sato, M.; Inoue, A.

    2008-01-01

    As it is known from the experiment that bulk metallic samples reflect microwaves while powdered samples can absorb such a radiation and be heated efficiently. In the present paper we investigate theoretically the mechanisms of penetration of a layer of metallic powder by microwave radiation and microwave heating of such a system

  10. Radiation losses in the microwave Ku band in magneto-electric nanocomposites

    Directory of Open Access Journals (Sweden)

    Talwinder Kaur

    2015-08-01

    Full Text Available A study on radiation losses in conducting polymer nanocomposites, namely La–Co-substituted barium hexaferrite and polyaniline, is presented. The study was performed by means of a vector network analyser, X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, electron spin resonance spectroscopy and a vibrating sample magnetometer. It is found that the maximum loss occurs at 17.9 GHz (−23.10 dB, 99% loss which is due to the composition of a conducting polymer and a suitable magnetic material. A significant role of polyaniline has been observed in ESR. The influence of the magnetic properties on the radiation losses is explained. Further studies revealed that the prepared material is a nanocomposite. FTIR spectra show the presence of expected chemical structures such as C–H bonds in a ring system at 1512 cm−1.

  11. A comparison of radiative transfer models for predicting the microwave emission from soils

    Science.gov (United States)

    Schmugge, T. J.; Choudhury, B. J.

    1981-01-01

    Noncoherent and coherent numerical models for predicting emission from soils are compared. Coherent models use the boundary conditions on the electric fields across the layer boundaries to calculate the radiation intensity, and noncoherent models consider radiation intensities directly. Interference may cause different results in the two approaches when coupling between soil layers in coherent models causes greater soil moisture sampling depths. Calculations performed at frequencies of 1.4 and 19.4 GHz show little difference between the models at 19.4 GHz, although differences are apparent at the lower frequency. A definition for an effective emissivity is also given for when a nonuniform temperature profile is present, and measurements made from a tower show good agreement with calculations from the coherent model.

  12. Monochromic radiation through light-emitting diode (LED positively augments in vitro shoot regeneration in Orchid (Dendrobium sonia

    Directory of Open Access Journals (Sweden)

    Vandita Billore

    2017-07-01

    Full Text Available Monochromatic lights emitted by light-emitting diodes (LEDs have generated great interest for efficient and controlled growth in vitro, especially of plants which are endangered or require specific intensity and wavelength of light. In the present study, we have evaluated the effect of monochromatic LEDs on in vitro morphogenesis: growth, proliferation of shoot cultures, and rooting of Dendrobium sonia. Different light sources viz. white LEDs (W, blue LEDs (B, yellow LEDs (Y and red LEDs (R were tested under photoperiod of 16 h of exposure and 8 h of dark. The frequency of morphogenesis depended on the wavelength of the applied monochromatic light. Higher wavelength monochromatic light (yellow light was observed to induce higher shoot proliferation (98%, early PLB (protocorm-like bodies formation, differentiation into green buds and shoot initiation as compared to red, blue and white light treatments. Yellow light also yielded higher number of shoots per explants (29 shoots/explant than red, blue and white light treatments. The results suggest that the monochromatic light sources stimulate morphogenic effects on in vitro culture of Dendrobium sonia, and that yellow light treatment can be used to enhance the efficiency of micropropagation.

  13. Determination of the exposure speed of radiation emitted by the linear accelerator, using the code MCNP5 to evaluate the radiotherapy room shields of ABC Hospital

    International Nuclear Information System (INIS)

    Corral B, J. R.

    2015-01-01

    Humans should avoid exposure to radiation, because the consequences are harmful to health. Although there are different emission sources of radiation, generated by medical devices they are usually of great interest, since people who attend hospitals are exposed in one way or another to ionizing radiation. Therefore, is important to conduct studies on radioactive levels that are generated in hospitals, as a result of the use of medical equipment. To determine levels of exposure speed of a radioactive facility there are different methods, including the radiation detector and computational method. This thesis uses the computational method. With the program MCNP5 was determined the speed of the radiation exposure in the radiotherapy room of Cancer Center of ABC Hospital in Mexico City. In the application of computational method, first the thicknesses of the shields were calculated, using variables as: 1) distance from the shield to the source; 2) desired weekly equivalent dose; 3) weekly total dose equivalent emitted by the equipment; 4) occupation and use factors. Once obtained thicknesses, we proceeded to model the bunker using the mentioned program. The program uses the Monte Carlo code to probabilistic ally determine the phenomena of interaction of radiation with the shield, which will be held during the X-ray emission from the linear accelerator. The results of computational analysis were compared with those obtained experimentally with the detection method, for which was required the use of a Geiger-Muller counter and the linear accelerator was programmed with an energy of 19 MV with 500 units monitor positioning the detector in the corresponding boundary. (Author)

  14. Intercomparison of three microwave/infrared high resolution line-by-line radiative transfer codes

    Science.gov (United States)

    Schreier, Franz; Milz, Mathias; Buehler, Stefan A.; von Clarmann, Thomas

    2018-05-01

    An intercomparison of three line-by-line (lbl) codes developed independently for atmospheric radiative transfer and remote sensing - ARTS, GARLIC, and KOPRA - has been performed for a thermal infrared nadir sounding application assuming a HIRS-like (High resolution Infrared Radiation Sounder) setup. Radiances for the 19 HIRS infrared channels and a set of 42 atmospheric profiles from the "Garand dataset" have been computed. The mutual differences of the equivalent brightness temperatures are presented and possible causes of disagreement are discussed. In particular, the impact of path integration schemes and atmospheric layer discretization is assessed. When the continuum absorption contribution is ignored because of the different implementations, residuals are generally in the sub-Kelvin range and smaller than 0.1 K for some window channels (and all atmospheric models and lbl codes). None of the three codes turned out to be perfect for all channels and atmospheres. Remaining discrepancies are attributed to different lbl optimization techniques. Lbl codes seem to have reached a maturity in the implementation of radiative transfer that the choice of the underlying physical models (line shape models, continua etc) becomes increasingly relevant.

  15. Electron Microscopy Study of Stainless Steel Radiation Damage Due to Long-Term Irradation by Alpha Particles Emitted From Plutonium

    Energy Technology Data Exchange (ETDEWEB)

    Unlu, Kenan [Univ. of Texas, Austin, TX (United States); Rios-Martinez, Carlos [Univ. of Texas, Austin, TX (United States); Saglam, Mehmet [Univ. of Texas, Austin, TX (United States); Hart, Ron R. [Texas A & M Univ., College Station, TX (United States); Shipp, John D. [Texas A & M Univ., College Station, TX (United States); Rennie, John [Texas A & M Univ., College Station, TX (United States)

    1998-04-16

    Radiation damage and associated surface and microstructural changes produced in stainless steel encapsulation by high-fluence alpha particle irradiations from weapons-grade plutonium of 316-stainless steel are being investigated.

  16. Simple method for routine check of the constancy of radiation quality of bremsstrahlung emitted by therapeutic particle accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Rassow, J; Eipper, H H; Krause, K [Essen Univ. (Gesamthochschule) (Germany, F.R.). Abt. fuer Klinische Strahlenphysik; Staedtisches Krankenhaus Koeln-Merheim (Germany, F.R.). Roentgeninstitut und Strahlenklinik)

    1977-05-01

    The constancy of the radiation quality of therapeutically employed particle accelerators has to be checked at weekly intervals. Any change in radiation quality may have considerable therapeutic effects owing to its influence on dose distribution. It is recommended that measurements be made instead of, or in addition to, the axial reference-point measurement at 5 and 15 cm depth in the phantom, at 5 cm depth in the beam axis and at a reference-point about 1 cm within the geometric edge of the field, for checking the constancy of the radiation quality of bremsstrahlung. Only then, if routine checks carried out for the axial and the lateral reference-point dose ratios do not show any deviations greater than e.g. +-2 %, radiation quality is deemed to have remained sufficiently constant for radiotherapeutical applications.

  17. Features of Microwave Radiation and Magnetographic Characteristics of Solar Active Region NOAA 12242 Before the X1.8 Flare on December 20, 2014

    Science.gov (United States)

    Abramov-Maximov, V. E.; Borovik, V. N.; Opeikina, L. V.; Tlatov, A. G.; Yasnov, L. V.

    2017-12-01

    This paper continues the cycle of authors' works on the detection of precursors of large flares (M5 and higher classes) in active regions (ARs) of the Sun by their microwave radiation and magnetographic characteristics. Generalization of the detected precursors of strong flares can be used to develop methods for their prediction. This paper presents an analysis of the development of NOAA AR 12242, in which an X1.8 flare occurred on December 20, 2014. The analysis is based on regular multiazimuth and multiwavelength observations with the RATAN-600 radio telescope in the range 1.65-10 cm with intensity and circular polarization analysis and data from the Solar Dynamics Observatory (SDO). It was found that a new component appeared in the AR microwave radiation two days before the X-flare. It became dominant in the AR the day before the flare and significantly decreased after the flare. The use of multiazimuth observations from RATAN-600 and observations at 1.76 cm from the Nobeyama Radioheliograph made it possible to identify the radio source that appeared before the X-flare with the site of the closest convergence of opposite polarity fields near the neutral line in the AR. It was established that the X-flare occurred 20 h after the total gradient of the magnetic field of the entire region calculated from SDO/HMI data reached its maximum value. Analysis of the evolution of the microwave source that appeared before the X-flare in AR 12242 and comparison of its parameters with the parameters of other components of the AR microwave radiation showed that the new source can be classified as neutral line associated sources (NLSs), which were repeatedly detected by the RATAN-600 and other radio telescopes 1-3 days before the large flares.

  18. Interaction between the radiative flux emitted by a corium melt and aerosols from corium/concrete interaction

    Energy Technology Data Exchange (ETDEWEB)

    Zabiego, M.; Cognet, G. [CEA-DRN/DER/SERA - CE Cadarache, Saint-Paul-Lez-Durance (France); Henderson, D. [Univ. of Wisconsin, Madison, WI (United States)

    1995-09-01

    In this paper we present a one-dimensional numerical model that deals with radiative transfer in a medium where aerosols are present. This model is written with the aim of performing radiative transfer calculations in the framework of severe Pressurized Water Reactor accidents, especially during the last stage of such an accident Molten Core Concrete Interaction (MCCI) when aerosols are very numerous. We explain the theoretical basis of our model, writing the general radiative transfer equation, knowing that aerosol droplets participate in radiation transport. We then simplify this equation for a one-dimensional medium and we propose to solve it using the spherical harmonics approximation. This gives us the radiative intensity and we can then deduce the radiative flux. Aerosol optical properties (extinction and scattering coefficients) are also required in such a calculation. They are determined using Rayleigh or Mie theory, depending, depending on the aerosol size. In order to provide an example of results one can expect from such a calculation, we applied our model to a test problem with given aerosol size and concentration distributions. Our example does not model any experiment explicitly but the physical conditions used are very close to the L4 test from the Advanced Containment Experiment (ACE) program.

  19. Influence of the magnetic field in the time evolution of the solar explosion radiation in X-ray and microwaves

    International Nuclear Information System (INIS)

    Costa, J.E.R.

    1983-01-01

    It has been made a theoretical development, sel-consistent with recent models for the explosive source, applied to time delays of peak emission at different microwave frequencies, and between microwaves and hard X-ray emission. A working hipothesis has been assumed with the adoption of a growing magnetic field during the solar flare explosion, and therefore contributing to a growth in microwave emission, differential in frequency, producing delays of maximum emission towards lower microwave frequencies, and delays of microwave maximum emission with respect to hard X-rays. It has been found that these delays are consistent with a growth in the magnetic field of about 14% by assuming both thermal and non-thermal models. This variation in magnetic field has been associated to movements of thermal sources downwards in the solar atmosphere, and it has been found that the estimated velocities of displacement were consistent compared to characteristic velocities of anomalous conduction fronts of thermal models. (Author) [pt

  20. Southern Hemisphere Measurement of the Anisotropy in the CosmicMicrowave Background Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Smoot, George F.; Lubin, Phil M.

    1979-06-01

    A recent measurement of the anisotropy in the Cosmic Background Radiation from the southern hemisphere (Lima, Peru) is essentially in agreement with previous measurements from the northern hemisphere. The net anisotropy can be described as a first order spherical harmonic (Doppler) anisotropy of amplitude 3.1 {+-} 0.4 m{sup o}K with a quadrupole anisotropy of less than 1 m{sup o}K. In addition, measurements of the linear polarization yield an upper limit of 1 m{sup o}K, or one part in 3000, at 95% C.L. for the amplitudes of any spherical harmonic through third order.

  1. Magnetic field dependence of microwave radiation in intermediate-length Josephson junctions

    DEFF Research Database (Denmark)

    Sørensen, Mads Peter; Parmentier, R. D.; Christiansen, Peter Leth

    1984-01-01

    furnish the current and field dependence of the oscillation configuration, from which can be calculated average voltages, frequencies, and power spectra. Simulation and experimental results are in good agreement with regard to the lobe structure of the height of the first zero-field step and/or second...... Fiske step in magnetic field and the field dependence of the radiation frequency within the various lobes, including details such as hysteresis between lobes. The simulations predict an alternation of the dominant frequency component with increasing field that accounts well for the experimental...

  2. Automatic control by natural gamma radiation emitted by coal; Control Automatico mediante Radiometria Gamma Natural de la Cenizas de los Carbones

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    Due to the characteristics of its coal and orebody, Monsacro shaft was chosen to host the test. The ash percentage of the different coal seams was carried out by two different methods: Traditional analysis in laboratory. Analysis by means of natural gamma radiation emitted by coal. The following conclusions were obtained after the test: Neither during the mounting nor during the test, a problem was encountered in the working of the radioactive methods. The absolute error between the two methods was minimum. The radioactive analysis is total (this means that the whole coal is analysed) and it is carried out in short period of time. The traditional one is just partial, and could take a few hours to accomplish it. The radioactive one is done in the wagon or in the belt conveyor directly, meanwhile the traditional one needs sample takers permanently. The investment cost of the radioactivity method is amortized within two years. (Author)

  3. Canada: Living with radiation

    International Nuclear Information System (INIS)

    1995-01-01

    Canadians are exposed daily to a variety of naturally occurring radiation. Heat and light from the sun, are familiar examples. Radium and uranium are naturally occurring materials which have been found to emit radiation and so have been called radioactive. There are also various types of artificially produced forms of radiation that are employed routinely in modern living, such as radio and television waves and microwaves. X-rays, another common type of radiation, are widely used in medicine as are some man-made radioactive substances. These emit radiation just like naturally occurring radioactive materials. Surveys have shown that many people have a poor understanding of the risks associated with the activities of modern living. Exposure to ionizing radiation from radioactive materials is also considered by many persons to have a high risk, This booklet attempts to inform the readers about ionizing radiation, its uses and the risks associated with it, and to put these risks in perspective with the risks of other activities and practices. A range of topics from medical uses of radiation to emergency planning, from biological effects of radiation to nuclear power, each topic is explained to relate radiation to our everyday lives. 44 figs

  4. Canada: Living with radiation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    Canadians are exposed daily to a variety of naturally occurring radiation. Heat and light from the sun, are familiar examples. Radium and uranium are naturally occurring materials which have been found to emit radiation and so have been called radioactive. There are also various types of artificially produced forms of radiation that are employed routinely in modern living, such as radio and television waves and microwaves. X-rays, another common type of radiation, are widely used in medicine as are some man-made radioactive substances. These emit radiation just like naturally occurring radioactive materials. Surveys have shown that many people have a poor understanding of the risks associated with the activities of modern living. Exposure to ionizing radiation from radioactive materials is also considered by many persons to have a high risk, This booklet attempts to inform the readers about ionizing radiation, its uses and the risks associated with it, and to put these risks in perspective with the risks of other activities and practices. A range of topics from medical uses of radiation to emergency planning, from biological effects of radiation to nuclear power, each topic is explained to relate radiation to our everyday lives. 44 figs.

  5. The influence of radiation and microwave agents on some properties of haemopoietic stem cells

    International Nuclear Information System (INIS)

    Barakina, N.F.; Rakhmanina, O.N.

    1985-01-01

    Sublethal irradiation of donors leads to a change in some properties of bone marrow haemopoetic stem cells (HSC) during the exponential growth (days 1-8) of the syngeneic recipients in the spleen. They are: an increase in the rate of proliferation, a slight reduction in time of the population doubling, and a tendency toward an increase in the percentage of cells settled in the spleen after transplantation. Theses changes in the properties of HSC provide a more rapid repopulation thereof as compared to HSC of intact mice. In all appearance, a pretreatment of donors with AET and 2ADT does not influence the HSC changes induced by radiation, and, at the same time, retains the number of HSC at a high level

  6. Feasibility Study on S-Band Microwave Radiation and 3D-Thermal Infrared Imaging Sensor-Aided Recognition of Polymer Materials from End-of-Life Vehicles

    Directory of Open Access Journals (Sweden)

    Jiu Huang

    2018-04-01

    Full Text Available With the increase the worldwide consumption of vehicles, end-of-life vehicles (ELVs have kept rapidly increasing in the last two decades. Metallic parts and materials of ELVs can be easily reused and recycled, but the automobile shredder residues (ASRs, of which elastomer and plastic materials make up the vast majority, are difficult to recycle. ASRs are classified as hazardous materials in the main industrial countries, and are required to be materially recycled up to 85–95% by mass until 2020. However, there is neither sufficient theoretical nor practical experience for sorting ASR polymers. In this research, we provide a novel method by using S-Band microwave irradiation together with 3D scanning as well as infrared thermal imaging sensors for the recognition and sorting of typical plastics and elastomers from the ASR mixture. In this study, an industrial magnetron array with 2.45 GHz irradiation was utilized as the microwave source. Seven kinds of ELV polymer (PVC, ABS, PP, EPDM, NBR, CR, and SBR crushed scrap residues were tested. After specific power microwave irradiation for a certain time, the tested polymer materials were heated up to different extents corresponding to their respective sensitivities to microwave irradiation. Due to the variations in polymer chemical structure and additive agents, polymers have different sensitivities to microwave radiation, which leads to differences in temperature rises. The differences of temperature increase were obtained by a thermal infrared sensor, and the position and geometrical features of the tested scraps were acquired by a 3D imaging sensor. With this information, the scrap material could be recognized and then sorted. The results showed that this method was effective when the tested polymer materials were heated up to more than 30 °C. For full recognition of the tested polymer scraps, the minimum temperature variations of 5 °C and 10.5 °C for plastics and elastomers were needed

  7. Effects of 2450 MHz microwave radiation on meiosis and reproduction in male mice

    International Nuclear Information System (INIS)

    Manikowska-Czerska, E.; Czerski, P.; Leach, W.M.

    1988-01-01

    A series of studies to examine effects od continuous wave 2450 MHz radiation on meiosis and on chromosomes of germ cells in male CBA/CAY or ICR mice, by means of the spermatocyte (SCT), heritable translocation (HTT) and dominant lethal (DLT) tests is presented. Animals were exposed in an environmentally controlled waveguide system during two consecutive weeks, 30 minutes daily, six days a week. Specific absorption rates (SAR) were used in the range from 0.05 to 20 W/kg. With the SCT, it was demonstrated that chromosomal translocations can be induced by exposure during the first meiotic prophase, particularly during initial and early pachytene stages. The HTT results demonstrated that balanced translocations may be recovered among offspring of exposed males. The DLT provided confirmatory data on effects during prophase and indicated that chromosomal damage may be also induced by exposure of spermatids, during the maturation stage, and of spermatozoa. No changes were observed in spermatogonia. Thus, the effects of exposure were limited to one spermatogenic cycle. Genetically significant effects were induced at an SAR of 2 W/kg in the testes. For comparison, an SAR of 0.4 W/kg is used commonly as a basis for occupational exposure limits

  8. Microwave imaging

    CERN Document Server

    Pastorino, Matteo

    2010-01-01

    An introduction to the most relevant theoretical and algorithmic aspects of modern microwave imaging approaches Microwave imaging-a technique used in sensing a given scene by means of interrogating microwaves-has recently proven its usefulness in providing excellent diagnostic capabilities in several areas, including civil and industrial engineering, nondestructive testing and evaluation, geophysical prospecting, and biomedical engineering. Microwave Imaging offers comprehensive descriptions of the most important techniques so far proposed for short-range microwave imaging-in

  9. Effect of Electromagnetic Radiation Emitted from A Mobile Phone Station on Biochemical and Histological Structure of Some Rat Organs

    International Nuclear Information System (INIS)

    Lotfi, S.A.

    2011-01-01

    This study was carried out to investigate the effects of electromagnetic radiations (EMR), especially radio frequency (RF), which arises from mobile phone station on some parameter in serum and histological structure of some organs in male albino rats exposed to short (15 days) and long (30 days) periods. The long time exposure of the electromagnetic radiations can induce significant increase in the levels of testosterone, creatinine, urea and uric acid in the two exposure groups (15 and 30 days), while the serum total protein, albumin and globulin were decreased significantly after the long time of exposure as compared with control. The microscopic examination of liver, kidney and testes tissues revealed destruction and atrophy of cells in rats exposed to RF for 15 and 30 days. In conclusion, long term exposure of mobile phones station (EMR) induced harmful effects on blood parameter and histological structure of liver, kidney and testes tissues of rats.

  10. A Synthesizable Multicore Platform for Microwave Imaging

    DEFF Research Database (Denmark)

    Schleuniger, Pascal; Karlsson, Sven

    2014-01-01

    Active microwave imaging techniques such as radar and tomography are used in a wide range of medical, industrial, scientific, and military applications. Microwave imaging devices emit radio waves and process their reflections to reconstruct an image. However, data processing remains a challenge...

  11. Spectral and energetic study of the microwave level produced by various mobile telephone models in the user head

    International Nuclear Information System (INIS)

    Abu Kassem, I.

    2009-06-01

    The aim of this work is the investigation of real microwave (MW) emission level and propagation properties produced by samples of mobile phones taking as reference the guidelines recommended by the International Commission on Non Ionizing Radiation protection (ICNIRP). Measurements were performed using specified radiation meters for detecting microwaves. These measurements consisted the detecting of frequency spectrum and then the measurements of the strength of electric and magnetic fields as well as the power density. The instantaneous signal level was important for all studied mobile phones, and this level exceed the ICNIRP limits for large part of these phones. Taking into account the mean value, the major part of studies mobile phones respect the international limits. In fact, only 22% of studied mobile phones emit signals from the back side of the phone which exceed the ICNIRP limits. The emitted signal intensity decreases rapidly with distance; it becomes about 10 % of the maximum at 20 cm from the mobile phone. (author)

  12. The electronics in fluorescent bulbs and light emitting diodes (LED), rather than ultraviolet radiation, cause increased malignant melanoma incidence in indoor office workers and tanning bed users.

    Science.gov (United States)

    Milham, Samuel; Stetzer, Dave

    2018-07-01

    The epidemiology of cutaneous malignant melanoma (CMM) has a number of facets that do not fit with sunlight and ultraviolet light as the primary etiologic agents. Indoor workers have higher incidence and mortality rates of CMM than outdoor workers; CMM occurs in body locations never exposed to sunlight; CMM incidence is increasing in spite of use of UV blocking agents and small changes in solar radiation. Installation of two new fluorescent lights in the milking parlor holding area of a Minnesota dairy farm in 2015 caused an immediate drop in milk production. This lead to measurement of body amperage in humans exposed to modern non-incandescent lighting. People exposed to old and new fluorescent lights, light emitting diodes (LED) and compact fluorescent lights (CFL) had body amperage levels above those considered carcinogenic. We hypothesize that modern electric lighting is a significant health hazard, a carcinogen, and is causing increasing CMM incidence in indoor office workers and tanning bed users. These lights generate dirty electricity (high frequency voltage transients), radio frequency (RF) radiation, and increase body amperage, all of which have been shown to be carcinogenic. This could explain the failure of ultraviolet blockers to stem the malignant melanoma pandemic. Tanning beds and non-incandescent lighting could be made safe by incorporating a grounded Faraday cage which allows passage of ultraviolet and visible light frequencies and blocks other frequencies. Modern electric lighting should be fabricated to be electrically clean. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Shielding Efficiency of a Fabric Based on Amorphous Glass-Covered Magnetic Microwires to Radiation Emitted by a Mobile Phone in 2G and 3G Communication Technologies

    Directory of Open Access Journals (Sweden)

    Miclăuş Simona

    2017-12-01

    Full Text Available A dual band mobile phone model was used to check the shielding properties of an amorphous ferromagnetic textile against the radiation emitted by the handset. Two frequencies belonging to the 2nd and 3rd generation of mobile emission technologies were used, 897 MHz and 1950 MHz. The specific absorption rate (SAR of energy deposition in a human head phantom was measured in standardized conditions. The textile contained micrometric-diameter wires of a ferromagnetic mixture embedded in a thin glass coat and weaved in a specific way. A set of fabric orientations and configurations (layering were provided in the experiment in order to achieve a better shielding to the phone’s radiation. Compared with the non-shielded handset, SAR deposited in the head while using the fabric-covered phone could be decreased up to 30 % of its initial value – in case of 2G technology and up to 24 % – in case of 3G technology. This type of material shows one of the highest shielding efficiencies of the electric-field component in near-field exposure conditions reported until now. A cubic curve of SAR decrease in depth of the head was revealed in both uncovered and covered handset, the effect of shielding being larger at the higher frequency.

  14. Combined application of sub-toxic level of silver nanoparticles with low powers of 2450 MHz microwave radiation lead to kill Escherichia coli in a short time

    Directory of Open Access Journals (Sweden)

    Bardia Varastehmoradi

    2013-09-01

    Full Text Available   Objective(s: Electromagnetic radiations which have lethal effects on the living cells are currently also considered as a disinfective physical agent.   Materials and Methods: In this investigation, silver nanoparticles were applied to enhance the lethal action of low powers (100 and 180 W of 2450 MHZ electromagnetic radiation especially against Escherichia coli ATCC 8739. Silver nanoparticles were biologically prepared and used for next experiments. Sterile normal saline solution was prepared and supplemented by silver nanoparticles to reach the sub-inhibitory concentration (6.25 μg/mL. Such diluted silver colloid as well as free-silver nanoparticles solution was inoculated along with test microorganisms, particularly E. coli. These suspensions were separately treated by 2450 MHz electromagnetic radiation for different time intervals in a microwave oven operated at low powers (100 W and 180 W. The viable counts of bacteria before and after each radiation time were determined by colony-forming unit (CFU method. Results: Results showed that the addition of silver nanoparticles significantly decreased the required radiation time to kill vegetative forms of microorganisms. However, these nanoparticles had no combined effect with low power electromagnetic radiation when used against Bacillus subtilis spores. Conclusion: The cumulative effect of silver nanoparticles and low powers electromagnetic radiation may be useful in medical centers to reduce contamination in polluted derange and liquid wastes materials and some devices.

  15. Instrument development for atmospheric radiation measurement (ARM): Status of the Atmospheric Emitted Radiance Interferometer - extended Resolution (AERI-X), the Solar Radiance Transmission Interferometer (SORTI), and the Absolute Solar Transmission Inferometer (ASTI)

    Energy Technology Data Exchange (ETDEWEB)

    Murcray, F.; Stephen, T.; Kosters, J. [Univ. of Denver, CO (United States)

    1996-04-01

    This paper describes three instruments currently under developemnt for the Atmospheric Radiation Measurement (ARM) Program at the University of Denver: the AERI-X (Atmospheric Emitted Radiance Interferometer-Extended Resolution) and the SORTI (Solar R adiance Transmission Interferometer), and ASTI (Absolute Solar transmission Interferometer).

  16. [Occupational exposure of welders to ultraviolet and "blue light" radiation emitted during TIG and MMA welding based on field measurements].

    Science.gov (United States)

    Wolska, Agnieszka

    2013-01-01

    The aim of the study was to present the results of welders' occupational exposure to "blue light" and UV radiation carried out at industrial workstations during TIG and MMA welding. Measurements were performed at 13 workstations (TIG welding: 6; MMA welding: 7), at which different welding parameters and materials were used. The radiation level was measured using a wide-range radiometer and a set of detectors, whose spectral responses were adequately fit to particular hazard under study. The measurement points corresponded with the location of eye and hand. The highest values of eye irradiance were found for aluminum TIG welding. Effective irradiance of actinic UV was within the range E(s) = 7.79-37.6 W/m2; UVA total irradiance, E(UVA) = 18-53.1 W/m2 and effective blue-light irradiance E(B) = 35-67 W/m2. The maximum allowance time ranged from 1.7 to 75 s, which means that in some cases even unintentional very short eye exposure can exceed MPE. The influence of welded material and the type of electrode coating on the measured radiation level were evidenced. The exceeded value of MPE for photochemical hazard arising for the eyes and skin was found at all measured workstations. Welders should use appropriately the eye and face protective equipment and avoid direct staring at welding arc when starting an arc-welding operation. Besides, the lack of head and neck skin protection can induce acute and chronic harmful health effects. Therefore, an appropriate wear of personal protective equipment is essential for welders' health.

  17. Occupational exposure of welders to ultraviolet and "blue light" radiation emitted during TIG and MMA welding based on field measuremants

    Directory of Open Access Journals (Sweden)

    Agnieszka Wolska

    2013-02-01

    Full Text Available Background: The aim of the study was to present the results of welders' occupational exposure to "blue light" and UV radiation carried out at industrial workstations during TIG and MMA welding. Materials and methods: Measurements were performed at 13 workstations (TIG welding: 6; MMA welding: 7, at which different welding parameters and materials were used. The radiation level was measured using a wide-range radiometer and a set of detectors, whose spectral responses were adequately fit to particular hazard under study. The measurement points corresponded with the location of eye and hand. Results: The highest values of eye irradiance were found for aluminum TIG welding. Effective irradiance of actinic UV was within the range Es = 7.79-37.6 W/m2; UVA total irradiance, EUVA = 18-53.1 W/m2 and effective blue-light irradiance EB = 35-67 W/m2. The maximum allowance time ranged from 1.7 to 75 s, which means that in some cases even unintentional very short eye exposure can exceed MPE. Conclusions: The influence of welded material and the type of electrode coating on the measured radiation level were evidenced. The exceeded value of MPE for photochemical hazard arising for the eyes and skin was found at all measured workstations. Welders should use appropriately the eye and face protective equipment and avoid direct staring at welding arc when starting an arcwelding operation. Besides, the lack of head and neck skin protection can induce acute and chronic harmful health effects. Therefore, an appropriate wear of personal protective equipment is essential for welders' health. Med Pr 2013;64(1:69–82

  18. Microwave Heating of a Liquid Stably Flowing in a Circular Channel Under the Conditions of Nonstationary Radiative-Convective Heat Transfer

    Science.gov (United States)

    Salomatov, V. V.; Puzyrev, E. M.; Salomatov, A. V.

    2018-05-01

    A class of nonlinear problems of nonstationary radiative-convective heat transfer under the microwave action with a small penetration depth is considered in a stabilized coolant flow in a circular channel. The solutions to these problems are obtained, using asymptotic procedures at the stages of nonstationary and stationary convective heat transfer on the heat-radiating channel surface. The nonstationary and stationary stages of the solution are matched, using the "longitudinal coordinate-time" characteristic. The approximate solutions constructed on such principles correlate reliably with the exact ones at the limiting values of the operation parameters, as well as with numerical and experimental data of other researchers. An important advantage of these solutions is that they allow the determination of the main regularities of the microwave and thermal radiation influence on convective heat transfer in a channel even before performing cumbersome calculations. It is shown that, irrespective of the heat exchange regime (nonstationary or stationary), the Nusselt number decreases and the rate of the surface temperature change increases with increase in the intensity of thermal action.

  19. A stochastic model for density-dependent microwave Snow- and Graupel scattering coefficients of the NOAA JCSDA community radiative transfer model

    Science.gov (United States)

    Stegmann, Patrick G.; Tang, Guanglin; Yang, Ping; Johnson, Benjamin T.

    2018-05-01

    A structural model is developed for the single-scattering properties of snow and graupel particles with a strongly heterogeneous morphology and an arbitrary variable mass density. This effort is aimed to provide a mechanism to consider particle mass density variation in the microwave scattering coefficients implemented in the Community Radiative Transfer Model (CRTM). The stochastic model applies a bicontinuous random medium algorithm to a simple base shape and uses the Finite-Difference-Time-Domain (FDTD) method to compute the single-scattering properties of the resulting complex morphology.

  20. Generation and acceleration of high-current annular electron beam in linear induction accelerator and generation of the power microwave radiation from Cherenkov TWT

    International Nuclear Information System (INIS)

    Abubakirov, E.V.; Arkhipov, O.V.; Bobyleva, L.V.

    1990-01-01

    The section of linear induction accelerator (LIA) with a strong guiding magnetic field (up to 1.5 T), with output beam power up to 2 GW and beam pulse duration 60 ns is created and investigated by experiment. The beam energy gain is equal to 10 keV/sm with explosive emission is used; the large length of the beam propagation (1.5 m) without spolling of the beam with high beam energy gain has been established. The microwave radiation power about 30-100 MW has achieved from relativistic Cherenkov travelling wave tube with high exponential gain on the basis of LIA and high-current diode

  1. George Smoot, Blackbody, and Anisotropy of the Cosmic Microwave Background

    Science.gov (United States)

    the Cosmic Microwave Background Radiation Resources with Additional Information * Videos 'George Smoot anisotropy of the cosmic microwave background radiation." '1 Smoot previously won the Ernest Orlando . Smoot, blackbody, and anisotropy of the Cosmic Microwave Background (CMB) radiation is available in full

  2. Radiation sickness

    Science.gov (United States)

    ... exposure to ionizing radiation. There are two main types of radiation: nonionizing and ionizing. Nonionizing radiation comes in the form of light, radio waves, microwaves and radar. These forms usually don't cause tissue damage. ...

  3. Microwave Irradiation

    Indian Academy of Sciences (India)

    Way to Eco-friendly, Green Chemistry. Rashmi ... The rapid heating of food in the kitchen using microwave ovens ... analysis; application to waste treatment; polymer technology; ... of microwave heating in organic synthesis since the first contri-.

  4. The sensitivity of tropical convective precipitation to the direct radiative forcings of black carbon aerosols emitted from major regions

    Directory of Open Access Journals (Sweden)

    C. Wang

    2009-10-01

    Full Text Available Previous works have suggested that the direct radiative forcing (DRF of black carbon (BC aerosols are able to force a significant change in tropical convective precipitation ranging from the Pacific and Indian Ocean to the Atlantic Ocean. In this in-depth analysis, the sensitivity of this modeled effect of BC on tropical convective precipitation to the emissions of BC from 5 major regions of the world has been examined. In a zonal mean base, the effect of BC on tropical convective precipitation is a result of a displacement of ITCZ toward the forcing (warming hemisphere. However, a substantial difference exists in this effect associated with BC over different continents. The BC effect on convective precipitation over the tropical Pacific Ocean is found to be most sensitive to the emissions from Central and North America due to a persistent presence of BC aerosols from these two regions in the lowermost troposphere over the Eastern Pacific. The BC effect over the tropical Indian and Atlantic Ocean is most sensitive to the emissions from South as well as East Asia and Africa, respectively. Interestingly, the summation of these individual effects associated with emissions from various regions mostly exceeds their actual combined effect as shown in the model run driven by the global BC emissions, so that they must offset each other in certain locations and a nonlinearity of this type of effect is thus defined. It is known that anthropogenic aerosols contain many scattering-dominant constituents that might exert an effect opposite to that of absorbing BC. The combined aerosol forcing is thus likely differing from the BC-only one. Nevertheless, this study along with others of its kind that isolates the DRF of BC from other forcings provides an insight of the potentially important climate response to anthropogenic forcings particularly related to the unique particulate solar absorption.

  5. Engineering aspect of the microwave ionosphere nonlinear interaction experiment (MINIX) with a sounding rocket

    Science.gov (United States)

    Nagatomo, Makoto; Kaya, Nobuyuki; Matsumoto, Hiroshi

    The Microwave Ionosphere Nonlinear Interaction Experiment (MINIX) is a sounding rocket experiment to study possible effects of strong microwave fields in case it is used for energy transmission from the Solar Power Satellite (SPS) upon the Earth's atmosphere. Its secondary objective is to develop high power microwave technology for space use. Two rocket-borne magnetrons were used to emit 2.45 GHz microwave in order to make a simulated condition of power transmission from an SPS to a ground station. Sounding of the environment radiated by microwave was conducted by the diagnostic package onboard the daughter unit which was separated slowly from the mother unit. The main design drivers of this experiment were to build such high power equipments in a standard type of sounding rocket, to keep the cost within the budget and to perform a series of experiments without complete loss of the mission. The key technology for this experiment is a rocket-borne magnetron and high voltage converter. Location of position of the daughter unit relative to the mother unit was a difficult requirement for a spin-stabilized rocket. These problems were solved by application of such a low cost commercial products as a magnetron for microwave oven and a video tape recorder and camera.

  6. Microwave heating processes involving carbon materials

    Energy Technology Data Exchange (ETDEWEB)

    Menendez, J.A.; Arenillas, A.; Fidalgo, B.; Fernandez, Y.; Zubizarreta, L.; Calvo, E.G.; Bermudez, J.M. [Instituto Nacional del Carbon, CSIC, Apartado 73, 33080 Oviedo (Spain)

    2010-01-15

    Carbon materials are, in general, very good absorbents of microwaves, i.e., they are easily heated by microwave radiation. This characteristic allows them to be transformed by microwave heating, giving rise to new carbons with tailored properties, to be used as microwave receptors, in order to heat other materials indirectly, or to act as a catalyst and microwave receptor in different heterogeneous reactions. In recent years, the number of processes that combine the use of carbons and microwave heating instead of other methods based on conventional heating has increased. In this paper some of the microwave-assisted processes in which carbon materials are produced, transformed or used in thermal treatments (generally, as microwave absorbers and catalysts) are reviewed and the main achievements of this technique are compared with those obtained by means of conventional (non microwave-assisted) methods in similar conditions. (author)

  7. Microwave radiation improves biodiesel yields from waste cooking oil in the presence of modified coal fly ash

    Directory of Open Access Journals (Sweden)

    Yulin Xiang

    2017-11-01

    Full Text Available This paper studied the effects of using modified coal fly ash as a catalyst to convert waste cooking oil (WCO into biodiesel under microwave-strengthened action. Coal fly ash was modified with sodium sulphate and sodium hydroxide, and the obtained catalyst was characterized using FT-IR and X-ray diffraction (XRD. The experimental results showed that the modified coal fly ash catalyst improved biodiesel yields under the microwave-assisted system, and the maximum biodiesel yield from waste cooking oil reached 94.91% at a molar ratio of methanol to WCO of 9.67:1 with 3.99% wt% of modified coal fly ash catalyst (based on oil weight at a 66.20 °C reaction temperature. The reusability of the modified coal fly ash catalyst was excellent, and the conversion yield remained greater than 90% after the catalyst was reused 8 times. The produced biodiesel met the main parameters of the ASTM D-6751 and EN14214 standards. Keywords: Biodiesel, Modified coal fly ash, Microwave assisted system, Waste cooking oil

  8. X-radiation /E greater than 10 keV/, H-alpha and microwave emission during the impulsive phase of solar flares.

    Science.gov (United States)

    Vorpahl, J. A.

    1972-01-01

    A study has been made of the variation in hard (E greater than 10 keV) X-radiation, H-alpha and microwave emission during the impulsive phase of solar flares. Analysis shows that the rise-time in the 20-30-keV X-ray spike depends on the electron hardness. The impulsive phase is also marked by an abrupt, very intense increase in H-alpha emission in one or more knots of the flare. Properties of these H-alpha kernels include: (1) a luminosity several times greater than the surrounding flare, (2) an intensity rise starting about 20-30 sec before, peaking about 20-25 sec after, and lasting about twice as long as the hard spike, (3) a location lower in the chromosphere than the remaining flare, (4) essentially no expansion prior to the hard spike, and (5) a position within 6000 km of the boundary separating polarities, usually forming on both sides of the neutral line near both feet of the same tube of force. Correspondingly, impulsive microwave events are characterized by: (1) great similarity in burst structure with 20-32 keV X-rays but only above 5000 MHz, (2) typical low frequency burst cutoff between 1400-3800 MHz, and (3) maximum emission above 7500 MHz.

  9. Monte Carlo simulation of age-dependent radiation dose from alpha- and beta-emitting radionuclides to critical trabecular bone and bone marrow targets

    Science.gov (United States)

    Dant, James T.; Richardson, Richard B.; Nie, Linda H.

    2013-05-01

    Alpha (α) particles and low-energy beta (β) particles present minimal risk for external exposure. While these particles can induce leukemia and bone cancer due to internal exposure, they can also be beneficial for targeted radiation therapies. In this paper, a trabecular bone model is presented to investigate the radiation dose from bone- and marrow-seeking α and β emitters to different critical compartments (targets) of trabecular bone for different age groups. Two main issues are addressed with Monte Carlo simulations. The first is the absorption fractions (AFs) from bone and marrow to critical targets within the bone for different age groups. The other issue is the application of 223Ra for the radiotherapy treatment of bone metastases. Both a static model and a simulated bone remodeling process are established for trabecular bone. The results show significantly lower AFs from radionuclide sources in the bone volume to the peripheral marrow and the haematopoietic marrow for adults than for newborns and children. The AFs from sources on the bone surface and in the bone marrow to peripheral marrow and haematopoietic marrow also varies for adults and children depending on the energy of the particles. Regarding the use of 223Ra as a radionuclide for the radiotherapy of bone metastases, the simulations show a significantly higher dose from 223Ra and its progeny in forming bone to the target compartment of bone metastases than that from two other more commonly used β-emitting radiopharmaceuticals, 153Sm and 89Sr. There is also a slightly lower dose from 223Ra in forming bone to haematopoietic marrow than that from 153Sm and 89Sr. These results indicate a higher therapy efficiency and lower marrow toxicity from 223Ra and its progeny. In conclusion, age-related changes in bone dimension and cellularity seem to significantly affect the internal dose from α and β emitters in the bone and marrow to critical targets, and 223Ra may be a more efficient

  10. Organic Synthesis Using Microwaves and Supported Reagents

    Science.gov (United States)

    In the electromagnetic radiation region, microwaves (0.3GHz-300GHz) lie between radiowave (Rf) and infrared (IR) frequencies with relatively large wavelengths (1 mm-1 m). Microwaves, non-ionizing radiation incapable of breaking bonds, are a form of energy that manifest as heat t...

  11. Microwave undulator

    International Nuclear Information System (INIS)

    Batchelor, K.

    1986-03-01

    The theory of a microwave undulator utilizing a plane rectangular waveguide operating in the TE/sub 10n/ mode and other higher order modes is presented. Based on this, a possible undulator configuration is analyzed, leading to the conclusion that the microwave undulator represents a viable option for undulator wavelength down to about 1 cm where peak voltage and available microwave power considerations limit effectiveness. 4 refs., 4 figs

  12. Physical retrieval of precipitation water contents from Special Sensor Microwave/Imager (SSM/I) data. Part 1: A cloud ensemble/radiative parameterization for sensor response (report version)

    Science.gov (United States)

    Olson, William S.; Raymond, William H.

    1990-01-01

    The physical retrieval of geophysical parameters based upon remotely sensed data requires a sensor response model which relates the upwelling radiances that the sensor observes to the parameters to be retrieved. In the retrieval of precipitation water contents from satellite passive microwave observations, the sensor response model has two basic components. First, a description of the radiative transfer of microwaves through a precipitating atmosphere must be considered, because it is necessary to establish the physical relationship between precipitation water content and upwelling microwave brightness temperature. Also the spatial response of the satellite microwave sensor (or antenna pattern) must be included in the description of sensor response, since precipitation and the associated brightness temperature field can vary over a typical microwave sensor resolution footprint. A 'population' of convective cells, as well as stratiform clouds, are simulated using a computationally-efficient multi-cylinder cloud model. Ensembles of clouds selected at random from the population, distributed over a 25 km x 25 km model domain, serve as the basis for radiative transfer calculations of upwelling brightness temperatures at the SSM/I frequencies. Sensor spatial response is treated explicitly by convolving the upwelling brightness temperature by the domain-integrated SSM/I antenna patterns. The sensor response model is utilized in precipitation water content retrievals.

  13. Microwave Assisted Drug Delivery

    DEFF Research Database (Denmark)

    Jónasson, Sævar Þór; Zhurbenko, Vitaliy; Johansen, Tom Keinicke

    2014-01-01

    In this work, the microwave radiation is adopted for remote activation of pharmaceutical drug capsules inside the human body in order to release drugs at a pre-determined time and location. An array of controllable transmitting sources is used to produce a constructive interference at a certain...... focus point inside the body, where the drugs are then released from the specially designed capsules. An experimental setup for microwave activation has been developed and tested on a body phantom that emulates the human torso. A design of sensitive receiving structures for integration with a drug...

  14. Microwave Microscope

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Makes ultra-high-resolution field measurements. The Microwave Microscope (MWM) has been used in support of several NRL experimental programs involving sea...

  15. Microwave-assisted synthesis of Gd{sup 3+} doped PbI{sub 2} hierarchical nanostructures for optoelectronic and radiation detection applications

    Energy Technology Data Exchange (ETDEWEB)

    Shkir, Mohd, E-mail: shkirphysics@gmail.com; AlFaify, S.; Yahia, I.S.; Ganesh, V.; Shoukry, H.

    2017-03-01

    In this work, we report the simple, low temperature and rapid microwave-assisted synthesis of undoped and Gadolinium (III) doped lead iodide with different morphologies, i.e. nanorods of average diameter ~200 nm and hierarchical (flower-shaped) nanosheets of thicknesses less than 100 nm. Prepared nanostructures were typify in details using a variety of analytical techniques that reveal the well crystallinity with hexagonal structure. We found that by changing the concentrations of Gadolinium (III) one can tailor the size and shape of nanostructures of lead iodide. The presence of Gadolinium (III) doping was assessed by energy dispersive X-ray analysis. Optical band gap and Photoluminescence intensity are found to be enhanced due to Gadolinium (III) doping. The value of Gamma linear absorption coefficient is found to be enriched with doping, which suggests its application in radiation detection.

  16. Effect of lead salts on phase, morphologies and photoluminescence of nanocrystalline PbMoO4 and PbWO4 synthesized by microwave radiation

    Directory of Open Access Journals (Sweden)

    Phuruangrat Anukorn

    2016-09-01

    Full Text Available PbMoO4 and PbWO4 were successfully synthesized by microwave radiation using different lead salts (acetate, chloride, nitrate and sulfate and Na2MO4 (M = Mo, W in propylene glycol. The products were characterized by X-ray diffraction (XRD, scanning and transmission electron microscopy (SEM, TEM, Fourier transform infrared (FT-IR, Raman spectroscopy and photoluminescence (PL spectroscopy. In this research, morphologies, crystallization and photoluminescence of the products were influenced by the kinetics of anions, including the detection of M–O (M = Mo, W stretching modes in the (MO42− tetrahedrons. Photoluminescence of PbMoO4 synthesized from Pb(NO32 and of PbWO4 synthesized from PbCl2 showed the strongest blue emission due to the electronic diffusion in tetrahedrons at room temperature.

  17. Spectral investigation of hot-spot and cavity resonance effects on the terahertz radiation emitted from high-Tc superconducting Bi2Sr2CaCu2O8+δ single crystal mesa structures

    Science.gov (United States)

    Kadowaki, Kazuo; Watanabe, Chiharu; Minami, Hidetoshi; Yamamoto, Takashi; Kashiwagi, Takanari; Klemm, Richard

    2014-03-01

    Terahertz (THz) electromagnetic radiation emitted from high-Tc superconducting Bi2Sr2CaCu2O8+δ mesa structures in the case of single mesa and series-connected mesas is investigated by the FTIR spectroscopic technique while observing its temperature distribution simultaneously by a SiC photoluminescence technique. Changing the bias level, sudden jumps of the hot-spot position were clearly observed. Although the radiation intensity changes drastically associated with the jump of the hot spot position, the frequency is unaffected as long as the voltage per junction is kept constant. Since the frequency of the intense radiation satisfies the cavity resonance condition, we confirmed that the cavity resonance is of primarily importance for the synchronization of whole intrinsic Josephson junctions in the mesa for high power radiation. This work was supported in part by the Grant-in-Aid for challenging Exploratory Research, the Ministry of Education, Culture, Sports, Science & Technology (MEXT).

  18. Dynamic of microwave breakdown in the localized places of transmitting line driving by Cherenkov-type oscillator

    Science.gov (United States)

    Xie, Jialing; Chen, Changhua; Chang, Chao; Wu, Cheng; Shi, Yanchao; Cao, Yibing; Song, Zhimin; Zhang, Yuchuan

    2018-02-01

    A breakdown cavity is designed to study the breakdown phenomena of high-power microwaves in transmission waveguides. The maximum electric field within the cavity varies in amplitude from 400 kV/cm to 1.8 MV/cm and may surpass breakdown thresholds. The breakdown cavities were studied in particle-in-cell simulations and experiments, the results of which yielded waveforms that were consistent. The experimental results indicate that the microwave pulse does not shorten, and the amplitude of the electric field does not fall below 800 kV/cm. Moreover, large numbers of electrons are not emitted in microwaves below 670 kV/cm at 9.75 GHz frequency and 25-ns pulse width transmitted in stainless steel waveguides. The radiation waveforms of breakdown cavity with different materials are compared in experiments, with titanium material performing better.

  19. Ceramic matrix composites by microwave assisted CVI

    International Nuclear Information System (INIS)

    Currier, R.P.; Devlin, D.J.

    1993-01-01

    Chemical vapor infiltration (CVI) processes for producing continuously reinforced ceramic composites are reviewed. Potential advantages of microwave assisted CVI are noted and numerical studies of microwave assisted CVI are reviewed. The models predict inverted thermal gradients in fibrous ceramic preforms subjected to microwave radiation and suggest processing strategies for achieving uniformly dense composites. Comparisons are made to experimental results on silicon-based composite systems. The role played by the relative ability of fiber and matrix to dissipate microwave energy is noted. Results suggest that microwave induced inverted gradients can be exploited to promote inside-out densification. 10 refs., 2 figs

  20. Study of microwave components for an electron cyclotron resonance ...

    Indian Academy of Sciences (India)

    The working .... high voltage isolation, and low microwave radiation leakage to environment. ... material as air to see the real effects under actual environment. ..... chamber was in safe operation towards the permissible limit of microwave ...

  1. Microwave Powered Gravitationally Independent Medical Grade Water Generation, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — An innovative microwave system is proposed for the continuous production of medical grade water. This system will utilize direct absorption of microwave radiation to...

  2. Microwave warning device

    International Nuclear Information System (INIS)

    Shriner, W.

    1981-01-01

    A device for warning a person carrying or wearing it of the presence of dangerous microwave radiation is fully powered by the radiations being detected. A very low-wattage gas-discharge lamp is energized by a broadly or a sharply tuned receiver circuit including dipole antennas or one antenna and a ''grounding'' casing element. The casing may be largely and uniformly transparent or have different areas gradedly light-transmissive to indicate varying radiation intensities. The casing can be made in the shape of a pocket watch, fountain pen, bracelet or finger ring, etc

  3. The exemption from the requirement of registration and/or licensing of some sources. machines and devices emitting ionizing and /or on ionizing radiation: a proposed draft for Israeli regulations

    Energy Technology Data Exchange (ETDEWEB)

    Schlesinger, T; Margaliot, M [Israel Atomic Energy Commission, Yavne (Israel). Soreq Nuclear Research Center

    1997-11-16

    The licensing and authorization of the import, purchase, distribution, transportation and application of radioactive materials and devices emitting ionizing and/or non-ionizing radiation are carried out in Israel by the Ministries of the Environment and of Health. The legal basis for file authority of these Ministries in radiation protection matters is file {sup P}harmacists Regulation- Radioactive Elements and Products Thereof, 1981 (revision 1994) (PRREPT). Licenses are issued by the Chief Radiation Executive (CUE) appointed by the Minister of the Environment and the Minister of Health. The Regulations include a clause which enables the CUE to exempt certain amounts of radioactive materials from file requirements laid down in the PRREPT. The exemption clause is general and does not indicate the types and amounts of radioactive material may be exempted. The proposed draft Israeli regulations are related to exemption of some sources, machines and devices emitting ionizing and non-ionizing radiation, wife a suggestion to extend file above mentioned exemption clause to include some machines and devices and to provide an explicit and detailed list of materials, sources and devices to be exempted. Among these are the following: (authors)

  4. The exemption from the requirement of registration and/or licensing of some sources. machines and devices emitting ionizing and /or on ionizing radiation: a proposed draft for Israeli regulations

    International Nuclear Information System (INIS)

    Schlesinger, T.; Margaliot, M.

    1997-01-01

    The licensing and authorization of the import, purchase, distribution, transportation and application of radioactive materials and devices emitting ionizing and/or non-ionizing radiation are carried out in Israel by the Ministries of the Environment and of Health. The legal basis for file authority of these Ministries in radiation protection matters is file P harmacists Regulation- Radioactive Elements and Products Thereof, 1981 (revision 1994) (PRREPT). Licenses are issued by the Chief Radiation Executive (CUE) appointed by the Minister of the Environment and the Minister of Health. The Regulations include a clause which enables the CUE to exempt certain amounts of radioactive materials from file requirements laid down in the PRREPT. The exemption clause is general and does not indicate the types and amounts of radioactive material may be exempted. The proposed draft Israeli regulations are related to exemption of some sources, machines and devices emitting ionizing and non-ionizing radiation, wife a suggestion to extend file above mentioned exemption clause to include some machines and devices and to provide an explicit and detailed list of materials, sources and devices to be exempted. Among these are the following: (authors)

  5. Interaction of microwave radiation with the high mobility two-dimensional electron system in GaAs/AlGaAs heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Ramanayaka, A.N.; Ye, Tianyu; Liu, H.-C. [Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30303 (United States); Wegscheider, W. [Laboratorium fuer Festkoerperphysik, ETH Zurich, 8093 Zurich (Switzerland); Mani, R.G., E-mail: rmani@gsu.edu [Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30303 (United States)

    2014-11-15

    The influence of microwave excitation on the magnetotransport properties of the high mobility two-dimensional electron system (2DES) in the GaAs/AlGaAs heterostructure system is investigated by exploring (a) the dependence of the amplitude of the microwave-induced magnetoresistance-oscillations on the polarization direction of the linearly polarized microwaves and (b) the microwave reflection from the 2DES. The polarization study indicates that the amplitude of the magnetoresistance oscillations is remarkably responsive to the relative orientation between the linearly polarized microwaves and the current-axis in the specimen. At low microwave power, P, experiments indicate a strong sinusoidal variation in the diagonal resistance R{sub xx} vs. θ at the oscillatory extrema of the microwave-induced magnetoresistance oscillations. The reflection study indicates strong correlations between the microwave induced magnetoresistance oscillations and oscillatory features in the microwave reflection in a concurrent measurement of the magnetoresistance and the microwave magnetoreflection from the 2DES. The correlations are followed as a function of the microwave frequency and the microwave power, and the results are reported.

  6. Interaction of microwave radiation with the high mobility two-dimensional electron system in GaAs/AlGaAs heterostructures

    International Nuclear Information System (INIS)

    Ramanayaka, A.N.; Ye, Tianyu; Liu, H.-C.; Wegscheider, W.; Mani, R.G.

    2014-01-01

    The influence of microwave excitation on the magnetotransport properties of the high mobility two-dimensional electron system (2DES) in the GaAs/AlGaAs heterostructure system is investigated by exploring (a) the dependence of the amplitude of the microwave-induced magnetoresistance-oscillations on the polarization direction of the linearly polarized microwaves and (b) the microwave reflection from the 2DES. The polarization study indicates that the amplitude of the magnetoresistance oscillations is remarkably responsive to the relative orientation between the linearly polarized microwaves and the current-axis in the specimen. At low microwave power, P, experiments indicate a strong sinusoidal variation in the diagonal resistance R xx vs. θ at the oscillatory extrema of the microwave-induced magnetoresistance oscillations. The reflection study indicates strong correlations between the microwave induced magnetoresistance oscillations and oscillatory features in the microwave reflection in a concurrent measurement of the magnetoresistance and the microwave magnetoreflection from the 2DES. The correlations are followed as a function of the microwave frequency and the microwave power, and the results are reported

  7. Anomalous microwave emission from spinning nanodiamonds around stars

    Science.gov (United States)

    Greaves, J. S.; Scaife, A. M. M.; Frayer, D. T.; Green, D. A.; Mason, B. S.; Smith, A. M. S.

    2018-06-01

    Several interstellar environments produce anomalous microwave emission (AME), with brightness peaks at tens-of-gigahertz frequencies1. The emission's origins are uncertain; rapidly spinning nanoparticles could emit electric-dipole radiation2, but the polycyclic aromatic hydrocarbons that have been proposed as the carrier are now found not to correlate with Galactic AME signals3,4. The difficulty is in identifying co-spatial sources over long lines of sight. Here, we identify AME in three protoplanetary disks. These are the only known systems that host hydrogenated nanodiamonds5, in contrast with the very common detection of polycyclic aromatic hydrocarbons6. Using spectroscopy, the nanodiamonds are located close to the host stars, at physically well-constrained temperatures7. Developing disk models8, we reproduce the emission with diamonds 0.75-1.1 nm in radius, holding ≤1-2% of the carbon budget. Ratios of microwave emission to stellar luminosity are approximately constant, allowing nanodiamonds to be ubiquitous, but emitting below the detection threshold in many star systems. This result is compatible with the findings of similar-sized diamonds within Solar System meteorites9. As nanodiamond spectral absorption is seen in interstellar sightlines10, these particles are also a candidate for generating galaxy-scale3 AME.

  8. Fundamental characteristics of microwave explosion pretreatment of wood. I, Properties of temperature development

    Science.gov (United States)

    Xian-jun Li; Ke-yang Lu; Lan-ying Lin; Yong-dong Zhou; Zhi-yong Cai; Feng Fu

    2010-01-01

    In this study, the effects of microwave radiation intensity, radiation time and initial wood moisture content (MC) on the properties of temperature development in Eucalyptus urophylla wood samples during the microwave explosion pretreatment have been investigated using a new microwave pretreatment equipment. The results show that 1) with the increase of microwave...

  9. The research and test of microwave preventer web

    International Nuclear Information System (INIS)

    Tao Songlei; Li Weicai; Ye Jian; Hong Tao; Tao Junbing

    2003-01-01

    To deal with the microwave's harm to the organism, a division-layer composed of several kinds of materials is set between the source of microwave and the protected target. By the use of the division-layer, the power density of field intensity of microwave will come up to a safe amount. The article puts forward a new microwave preventer for mobile telephone. Experiments show that the radiation power density nearby human brain can be reduced to 5 μW/cm 2 and below by using mobile telephone microwave preventer, which is in compliance with the state health standard for microwave radiation from the mobile phone

  10. Microwave off-gas treatment apparatus and process

    Science.gov (United States)

    Schulz, Rebecca L.; Clark, David E.; Wicks, George G.

    2003-01-01

    The invention discloses a microwave off-gas system in which microwave energy is used to treat gaseous waste. A treatment chamber is used to remediate off-gases from an emission source by passing the off-gases through a susceptor matrix, the matrix being exposed to microwave radiation. The microwave radiation and elevated temperatures within the combustion chamber provide for significant reductions in the qualitative and quantitative emissions of the gas waste stream.

  11. Microwave oscillator with 'whispering gallery' resonator

    International Nuclear Information System (INIS)

    Kirichenko, A.Ya.; Prokopenko, Yu.V.; Filippov, Yu.F.; Lonin, Yu.F.; Papkovich, V.G.; Ponomarev, A.G.; Prokopenko, Yu.V.; Uvarov, V.T.

    2010-01-01

    It was presented researches of a generation of microwave radiation into system with azimuthally periodical relativistic electron beam current that excites a high-Q quasi-optical dielectric resonator. The Eigen parameters of cylindrical Teflon resonator were determined by numerical computation. Registration of the microwave radiation realizes by a crystal set of 8-mm wavelength range. Research projects of microwave oscillators with high-Q resonators, in which 'whispering gallery' oscillations are excited by an electron flow, are presented. Multiresonator oscillators ideology is based on principles of microwave generation in klystrons with both subcritical and supercritical electron beams currents.

  12. Consideration on the Mechanism of Microwave Emission Due to Rock Fracture

    Science.gov (United States)

    Takano, Tadashi; Sugita, Seiji; Yoshida, Shingo; Maeda, Takashi

    2010-05-01

    Microwave emission due to rock fracture was found at 300 MHz, 2 GHz, and 22 GHz, and its power was calibrated in laboratory for the first time in the world. The observed waveform is impulsive, and contains correspondent frequency component inside the envelope at each frequency band. At such high frequencies, the electro-magnetic signal power can be calibrated as a radiating wave with high accuracy. Accordingly, it was verified that a substantial power is emitted. The microwave emission phenomena were also observed on occasions of hypervelocity impact, and esteemed as phenomena generally associated with material destruction. Earthquakes and volcanic activities are association with rock fractures so that the microwave is expected to be emitted. Actually, the e emission was confirmed by the data analysis of the brightness temperature obtained by a remote sensing satellite, which flew over great earthquakes of Wuenchan and Sumatra, and great volcanic eruptions of Reventador and Chanten. It is important to show the microwave emission during rock fracture in natural phenomena. Therefore, the field test to detect the microwave due to the collapse of a crater cliff was planned and persecuted at the volcano of Miyake-jima about 100 km south of Tokyo. Volcanic activity may be more convenient than an earthquake because of the known location and time. As a result, they observed the microwave emission which was strongly correlated with the cliff collapses. Despite of the above-mentioned phenomenological fruits, the reason of the microwave emission is not fixed yet. We have investigated the mechanism of the emission in consideration of the obtained data in rock fracture experiments so far and the study results on material destruction by hypervelocity impact. This paper presents the proposal of the hypothesis and resultant discussions. The microwave sensors may be useful to monitor natural hazards such as an earthquake or a volcanic eruption, because the microwave due to rock

  13. Cosmic microwave background, where next?

    CERN Multimedia

    CERN. Geneva

    2009-01-01

    Ground-based, balloon-borne and space-based experiments will observe the Cosmic Microwave Background in greater details to address open questions about the origin and the evolution of the Universe. In particular, detailed observations the polarization pattern of the Cosmic Microwave Background radiation have the potential to directly probe physics at the GUT scale and illuminate aspects of the physics of the very early Universe.

  14. Single-crystalline Bi2Sr2CaCu2O8+x detectors for direct detection of microwave radiation

    International Nuclear Information System (INIS)

    Li, M.; Winkler, D.; Yurgens, A.

    2015-01-01

    We test radiation detectors made from single-crystalline Bi 2 Sr 2 CaCu 2 O 8+x flakes put on oxidized Si substrates. The 100-nm-thick flakes are lithographically patterned into 4×12 μm 2 large rectangles embedded in thin-film log-spiral antennas. The SiO 2 layer weakens the thermal link between the flakes and the bath. Two modes of radiation detection have been observed. For a bolometric type of sensors a responsivity of ∼300 V/W and a noise equivalent power of 30 nW/√(Hz) has been deduced at 70 K. Much more sensitive is the non-bolometric device showing characteristics similar to a Golay-type detector while being at least a thousand times faster. Making smaller (sub-μm) structures is expected to significantly improve the performance of these devices and makes them very competitive among other microwave and terahertz detectors

  15. Gauge invariant perturbation theory prediction of the sensitivity required for experimental measurement of quadrupole and higher moments of the cosmic microwave background radiation

    International Nuclear Information System (INIS)

    Wilson, K.E.

    1985-01-01

    The temperature variation of the cosmic microwave background radiation is computed in a spherical harmonic expansion for a 4 million term sum of perturbations. Each term has a different direction and a randomly chosen phase. The spherical harmonics are evaluated for values of the index l from 1 through 9. The computation was done by starting with the model for gauge invariant cosmological perturbations composed by James M. Bardeen (1980). This model does linear perturbation theory against a background Friedmann-Robertson-Walker general relativistic cosmological model. The Bardeen model was recomputed for a cosmological-time metric then solved for zero curvature and zero cosmological constant in the background for radiation and dust equations of state. Instantaneous decoupling was assumed. The model was solved for zero curvature, cosmological constant, and pressure in perturbation order. These solutions were used to compute the redshift equation, and then the temperature variation equation. The integral over the null geodesic (photon) path can be evaluated analytically under the zero curvature cosmological constant, and pressure assumption. Analytic equations are obtained for the temperature variation caused by an isothermal or adiabatic perturbation of a single mode (amplitude, wavelength, phase, and direction)

  16. Small-scale angular fluctuations in the microwave background radiation and the existence of isolated large-scale structures in the universe

    International Nuclear Information System (INIS)

    Goicoechea, L.J.; Sanz, J.L.

    1985-01-01

    The relative fluctuation of the present temperature associated with the microwave background radiation (MBR) on a small angular scale, (deltaT/T) 0 , can be related for a general inhomogeneous cosmological model to the kinematical quantities, their gradients, and the Weyl tensor through the geodesic deviation equation. We apply this result to calculate the induction of temperature fluctuations in the MBR by a spherically symmetric cluster (or void) of matter or radiation or both, considered as a perturbation in a flat Friedmann universe, with negligible pressure. For an isolated object (void or cluster) with radius roughly-equal10 3 h -1 Mpc and located outside our present horizon, we have found, taking into account recent data on the anisotropies of the MBR at an angular scale 6 0 , that the relative mass fluctuation is bounded by deltaVertical BarM/MVertical Bar 2 h -1 Mpc and distance from the observer to the center approx. =10h -1 Mpc), the observational angular fluctuations of the MBR imply that deltaVertical BarM/MVertical Bar< or approx. =10%

  17. The amplitude and spectral index of the large angular scale anisotropy in the cosmic microwave background radiation

    Science.gov (United States)

    Ganga, Ken; Page, Lyman; Cheng, Edward; Meyer, Stephan

    1994-01-01

    In many cosmological models, the large angular scale anisotropy in the cosmic microwave background is parameterized by a spectral index, n, and a quadrupolar amplitude, Q. For a Harrison-Peebles-Zel'dovich spectrum, n = 1. Using data from the Far Infrared Survey (FIRS) and a new statistical measure, a contour plot of the likelihood for cosmological models for which -1 less than n less than 3 and 0 equal to or less than Q equal to or less than 50 micro K is obtained. Depending upon the details of the analysis, the maximum likelihood occurs at n between 0.8 and 1.4 and Q between 18 and 21 micro K. Regardless of Q, the likelihood is always less than half its maximum for n less than -0.4 and for n greater than 2.2, as it is for Q less than 8 micro K and Q greater than 44 micro K.

  18. Cosmic 21 cm delensing of microwave background polarization and the minimum detectable energy scale of inflation.

    Science.gov (United States)

    Sigurdson, Kris; Cooray, Asantha

    2005-11-18

    We propose a new method for removing gravitational lensing from maps of cosmic microwave background (CMB) polarization anisotropies. Using observations of anisotropies or structures in the cosmic 21 cm radiation, emitted or absorbed by neutral hydrogen atoms at redshifts 10 to 200, the CMB can be delensed. We find this method could allow CMB experiments to have increased sensitivity to a background of inflationary gravitational waves (IGWs) compared to methods relying on the CMB alone and may constrain models of inflation which were heretofore considered to have undetectable IGW amplitudes.

  19. Cyclotron Line in Solar Microwave Radiation by Radio Telescope RATAN-600 Observations of the Solar Active Region NOAA 12182

    Science.gov (United States)

    Peterova, N. G.; Topchilo, N. A.

    2017-12-01

    This paper presents the results of observation of a rare phenomenon—a narrowband increase in the brightness of cyclotron radiation of one of the structural details of a radio source located in the solar corona above the solar active region NOAA 12182 in October 2014 at a frequency of 4.2 ± 0.1 GHz. The brightness of radiation in the maximum of the phenomenon has reached 10 MK; its duration was equal to 3 s. The exact location of the source of the narrowband cyclotron radiation is indicated: it is a corona above a fragmented (4-nuclear) sunspot, on which a small UV flare loop was closed.

  20. The study and the realization of radiation detectors made from polycrystalline diamond films grown by microwave plasma enhanced chemical vapour deposition technique

    International Nuclear Information System (INIS)

    Jany, Ch.

    1998-01-01

    The aim of this work was to develop radiation detectors made from polycrystalline diamond films grown by microwave plasma enhanced chemical vapour deposition technique. The influence of surface treatments, contact technology and diamond growth parameters on the diamond detectors characteristics was investigated in order to optimise the detector response to alpha particles. The first part of the study focused on the electrical behaviour of as-deposited diamond surface, showing a p type conduction and its influence on the leakage current of the device. A surface preparation process was established in order to reduce the leakage current of the device by surface dehydrogenation using an oxidising step. Several methods to form and treat electrical contacts were also investigated showing that the collection efficiency of the device decreases after contact annealing. In the second part, we reported the influence of the diamond deposition parameters on the characteristics of the detectors. The increase of the deposition temperature and/or methane concentration was shown to lead η to decrease. In contrast, η was found to increase with the micro-wave power. The evolution of the diamond detector characteristics results from the variation in sp 2 phases incorporation and in the crystallography quality of the films. These defects increase the leakage current and reduce the carrier mobility and lifetime. Measurements carried out on detectors with different thicknesses showed that the physical properties varies along the growth direction, improving with the film thickness. Finally, the addition of nitrogen (> 10 ppm) in the gas mixture during diamond deposition was found to strongly reduce the collection efficiency of the detectors. To conclude the study, we fabricated and characterised diamond devices which were used for thermal neutron detection and for the intensity and shape measurement of VUV and soft X-ray pulses. (author)

  1. Microwave Measurements

    CERN Document Server

    Skinner, A D

    2007-01-01

    The IET has organised training courses on microwave measurements since 1983, at which experts have lectured on modern developments. Their lecture notes were first published in book form in 1985 and then again in 1989, and they have proved popular for many years with a readership beyond those who attended the courses. The purpose of this third edition of the lecture notes is to bring the latest techniques in microwave measurements to this wider audience. The book begins with a survey of the theory of current microwave circuits and continues with a description of the techniques for the measureme

  2. Microwave photonics

    CERN Document Server

    Lee, Chi H

    2006-01-01

    Wireless, optical, and electronic networks continue to converge, prompting heavy research into the interface between microwave electronics, ultrafast optics, and photonic technologies. New developments arrive nearly as fast as the photons under investigation, and their commercial impact depends on the ability to stay abreast of new findings, techniques, and technologies. Presenting a broad yet in-depth survey, Microwave Photonics examines the major advances that are affecting new applications in this rapidly expanding field.This book reviews important achievements made in microwave photonics o

  3. Microwave superheaters for fusion

    International Nuclear Information System (INIS)

    Campbell, R.B.; Hoffman, M.A.; Logan, B.G.

    1987-01-01

    The microwave superheater uses the synchrotron radiation from a thermonuclear plasma to heat gas seeded with an alkali metal to temperatures far above the temperature of material walls. It can improve the efficiency of the Compact Fusion Advanced Rankine (CFAR) cycle described elsewhere in these proceedings. For a proof-of-principle experiment using helium, calculations show that a gas superheat ΔT of 2000 0 K is possible when the wall temperature is maintained at 1000 0 K. The concept can be scaled to reactor grade systems. Because of the need for synchrotron radiation, the microwave superheater is best suited for use with plasmas burning an advanced fuel such as D- 3 He. 5 refs

  4. Reduced growth of soybean seedlings after exposure to weak microwave radiation from GSM 900 mobile phone and base station.

    Science.gov (United States)

    Halgamuge, Malka N; Yak, See Kye; Eberhardt, Jacob L

    2015-02-01

    The aim of this work was to study possible effects of environmental radiation pollution on plants. The association between cellular telephone (short duration, higher amplitude) and base station (long duration, very low amplitude) radiation exposure and the growth rate of soybean (Glycine max) seedlings was investigated. Soybean seedlings, pre-grown for 4 days, were exposed in a gigahertz transverse electromagnetic cell for 2 h to global system for mobile communication (GSM) mobile phone pulsed radiation or continuous wave (CW) radiation at 900 MHz with amplitudes of 5.7 and 41 V m(-1) , and outgrowth was studied one week after exposure. The exposure to higher amplitude (41 V m(-1)) GSM radiation resulted in diminished outgrowth of the epicotyl. The exposure to lower amplitude (5.7 V m(-1)) GSM radiation did not influence outgrowth of epicotyl, hypocotyls, or roots. The exposure to higher amplitude CW radiation resulted in reduced outgrowth of the roots whereas lower CW exposure resulted in a reduced outgrowth of the hypocotyl. Soybean seedlings were also exposed for 5 days to an extremely low level of radiation (GSM 900 MHz, 0.56 V m(-1)) and outgrowth was studied 2 days later. Growth of epicotyl and hypocotyl was found to be reduced, whereas the outgrowth of roots was stimulated. Our findings indicate that the observed effects were significantly dependent on field strength as well as amplitude modulation of the applied field. © 2015 Wiley Periodicals, Inc.

  5. Report by the work-group on 'safety of medical devices emitting ionizing radiations'. Articulation of radiation protection requirements of the 97/43/Euratom directive and IAEA recommendations with the essential requirements of the 93/42/CEE directive related to medical devices used in external radiotherapy

    International Nuclear Information System (INIS)

    2010-01-01

    As some dysfunctions and events had been reported in 2007 and 2008 in field of radiotherapy, this report aims at clarifying the articulation between the different European regulations concerning medical devices emitting ionizing radiations and radiation protection. The authors report a survey with device manufacturers, and analyze the content of the different regulations and recommendations. Then, the authors recommend and propose a set of actions related to the IAEA requirements and recommendations, to CE marking requirements, and to new radiation protection and safety requirements present in the Euratom directive

  6. Detailed spectra of high-power broadband microwave radiation from interactions of relativistic electron beams with weakly magnetized plasmas

    International Nuclear Information System (INIS)

    Kato, K.G.; Benford, G.; Tzach, D.

    1983-01-01

    Prodigious quantities of microwave energy distributed uniformly across a wide frequency band are observed when a relativistic electron beam (REB) penetrates a plasma. Typical measured values are 20 MW total for Δνapprox. =40 GHz with preliminary observations of bandwidths as large as 100 GHz. An intense annular pulsed REB (Iapprox. =128 kA; rapprox. =3 cm; Δrapprox. =1 cm; 50 nsec FWHM; γapprox. =3) is sent through an unmagnetized or weakly magnetized plasma column (n/sub plasma/approx.10 13 cm -3 ). Beam-to-plasma densities of 0.01 >ω/sub p/ and weak harmonic structure is wholly unanticipated from Langmuir scattering or soliton collapse models. A model of Compton-like boosting of ambient plasma waves by the beam electrons, with collateral emission of high-frequency photons, qualitatively explains these spectra. Power emerges largely in an angle approx.1/γ, as required by Compton mechanisms. As n/sub b//n/sub p/ falls, ω/sub p/-2ω/sub p/ structure and harmonic power ratios consistent with soliton collapse theories appear. With further reduction of n/sub b//n/sub p/ only the ω/sub p/ line persists

  7. Microwave Backscatter-Based Wireless Temperature Sensor Fabricated by an Alumina-Backed Au Slot Radiation Patch.

    Science.gov (United States)

    Lu, Fei; Wang, Haixing; Guo, Yanjie; Tan, Qiulin; Zhang, Wendong; Xiong, Jijun

    2018-01-16

    A wireless and passive temperature sensor operating up to 800 °C is proposed. The sensor is based on microwave backscatter RFID (radio frequency identification) technology. A thin-film planar structure and simple working principle make the sensor easy to operate under high temperature. In this paper, the proposed high temperature sensor was designed, fabricated, and characterized. Here the 99% alumina ceramic with a dimension of 40 mm × 40 mm × 1 mm was prepared in micromechanics for fabrication of the sensor substrate. The metallization of the Au slot patch was realized in magnetron sputtering with a slot width of 2 mm and a slot length of 32 mm. The measured resonant frequency of the sensor at 25 °C is 2.31 GHz. It was concluded that the resonant frequency decreases with the increase in the temperature in range of 25-800 °C. It was shown that the average sensor sensitivity is 101.94 kHz/°C.

  8. Modification of bamboo-based activated carbon using microwave radiation and its effects on the adsorption of methylene blue

    Energy Technology Data Exchange (ETDEWEB)

    Liu Qingsong; Zheng Tong; Li Nan [State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090 (China); Wang Peng, E-mail: pwang73@vip.sina.com [State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090 (China); Abulikemu, Gulizhaer [State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090 (China)

    2010-03-01

    Modification of bamboo-based activated carbon was carried out in a microwave oven under N{sub 2} atmosphere. The virgin and modified activated carbons were characterized by means of low temperature N{sub 2} adsorption, acid-base titration, point of zero charge (pH{sub pzc}) measurement, FTIR and XPS spectra. A gradual decrease in the surface acidic groups was observed during the modification, while the surface basicity was enhanced to some extent, which gave rise to an increase in the pH{sub pzc} value. The species of the functional groups and relative content of various elements and groups were given further analysis using FTIR and XPS spectra. An increase in the micropores was found at the start, and the micropores were then extended into larger ones, resulting in an increase in the pore volume and average pore size. Adsorption studies showed enhanced adsorption of methylene blue on the modified activated carbons, caused mainly by the enlargement of the micropores. Adsorption isotherm fittings revealed that Langmuir and Freundlich models were applicable for the virgin and modified activated carbons, respectively. Kinetic studies exhibited faster adsorption rate of methylene blue on the modified activated carbons, and the pseudo-second-order model fitted well for all of the activated carbons.

  9. Modification of bamboo-based activated carbon using microwave radiation and its effects on the adsorption of methylene blue

    Science.gov (United States)

    Liu, Qing-Song; Zheng, Tong; Li, Nan; Wang, Peng; Abulikemu, Gulizhaer

    2010-03-01

    Modification of bamboo-based activated carbon was carried out in a microwave oven under N 2 atmosphere. The virgin and modified activated carbons were characterized by means of low temperature N 2 adsorption, acid-base titration, point of zero charge (pH pzc) measurement, FTIR and XPS spectra. A gradual decrease in the surface acidic groups was observed during the modification, while the surface basicity was enhanced to some extent, which gave rise to an increase in the pH pzc value. The species of the functional groups and relative content of various elements and groups were given further analysis using FTIR and XPS spectra. An increase in the micropores was found at the start, and the micropores were then extended into larger ones, resulting in an increase in the pore volume and average pore size. Adsorption studies showed enhanced adsorption of methylene blue on the modified activated carbons, caused mainly by the enlargement of the micropores. Adsorption isotherm fittings revealed that Langmuir and Freundlich models were applicable for the virgin and modified activated carbons, respectively. Kinetic studies exhibited faster adsorption rate of methylene blue on the modified activated carbons, and the pseudo-second-order model fitted well for all of the activated carbons.

  10. Ecologically safe regimes of generation and maintenance of artificial ionized regions in the stratosphere by microwave radiation

    Science.gov (United States)

    Matveyev, A. A.; Silakov, V. P.

    1996-10-01

    A mathematical model of the artificial ionized region created in the atmosphere in the intersection zone of two beams of powerful coherent TE microwaves is presented. The model is based on the solution of the nonstationary system of Maxwell equations and kinetic Boltzmann equation for electrons, as well as on a vast ramified kinetic scheme of plasma chemical processes in humid air. In the framework of such a model, it is possible to calculate, in a correct and self-consistent way, the electrodynamic and kinetic characteristics of the artificial ionized regions (AIR) created in air at various altitudes. The calculations conducted for the stratosphere had revealed the possibility of realization at great altitudes (~55 km) of the regimes of the AIR prolonged maintenance that simultaneously have the following advantages: they require the minimum energy expenditures, ensure good radio-reflecting properties of the plasma structure and do not lead even to local degradation of the ozone layer. Modeling of the kinetic and photochemical processes proceeding at the postdischarge stage had shown that the destructive action of the NOx molecules produced in the discharge on the stratospheric ozone is substantially limited by their diffusive transport beyond the AIR boundaries. Production of excess active hydrogen radicals HOx in the discharge does not exert any essential influence on ozone due to fast proceeding of the reactions of their mutual binding.

  11. Gyrotron: an application of the relativistic bunching of electrons to the generation of intense millimeter microwave radiation

    International Nuclear Information System (INIS)

    Caplan, M.

    1986-01-01

    The cyclotron maser or gyrotron is capable of generating high power microwaves at millimeter wave frequencies for applications in fusion heating, radar astronomy and communications. Analytic and numerical simulation models are developed that describe the behavior of these devices under realistic laboratory conditions including the effects of circuit geometry, beam thermal spread, and mode competition. In Chapter 2, a generalized linear theory for the gyrotron is presented in the form of an integro-differential equation that can be solved within various circuit geometries thus describing gyro-amplifiers, gyro-oscillatory and gyroklystrons. In Chapter 3 a complete description of a finite size electromagnetic particle simulation model is presented that describes gyrotrons operating in a TE/sub mn/ waveguide mode. In Chapter 4 simulations and theoretical analysis are made of gyrotron amplifiers operating in the TE/sub 01/ mode. In Chapter 5 the linear eigenmodes and eigenfrequencies of gyrotron oscillators are examined. In Chapter 6 the experimental development of a GHz gyrotron is presented. Theoretical and numerical predictions of oscillation thresholds and efficiencies compare favorably with experimental data

  12. Modification of bamboo-based activated carbon using microwave radiation and its effects on the adsorption of methylene blue

    International Nuclear Information System (INIS)

    Liu Qingsong; Zheng Tong; Li Nan; Wang Peng; Abulikemu, Gulizhaer

    2010-01-01

    Modification of bamboo-based activated carbon was carried out in a microwave oven under N 2 atmosphere. The virgin and modified activated carbons were characterized by means of low temperature N 2 adsorption, acid-base titration, point of zero charge (pH pzc ) measurement, FTIR and XPS spectra. A gradual decrease in the surface acidic groups was observed during the modification, while the surface basicity was enhanced to some extent, which gave rise to an increase in the pH pzc value. The species of the functional groups and relative content of various elements and groups were given further analysis using FTIR and XPS spectra. An increase in the micropores was found at the start, and the micropores were then extended into larger ones, resulting in an increase in the pore volume and average pore size. Adsorption studies showed enhanced adsorption of methylene blue on the modified activated carbons, caused mainly by the enlargement of the micropores. Adsorption isotherm fittings revealed that Langmuir and Freundlich models were applicable for the virgin and modified activated carbons, respectively. Kinetic studies exhibited faster adsorption rate of methylene blue on the modified activated carbons, and the pseudo-second-order model fitted well for all of the activated carbons.

  13. Radiation losses in microwave K_u region by conducting pyrrole/barium titanate and barium hexaferrite based nanocomposites

    International Nuclear Information System (INIS)

    Kaur, Talwinder; Kumar, Sachin; Narang, S.B.; Srivastava, A.K.

    2016-01-01

    Nanocomposites of substituted barium hexaferrite and barium titanate embedded in a polymer were synthesized via emulsion polymerization. The study was performed by using X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, electron spin resonance spectroscopy, a vibrating sample magnetometer and a vector network analyzer. It is found that maximum radiation loss occur at 16.09 GHz (−14.23 dB) frequency owing to the combined effect of conducting polymer, suitable dielectric and magnetic material. This suggests that prepared material is suitable for radiation losses. Micro structural study reveals the presence of all the phases of the compounds comprises composite. Benzene ring absorption band (at 1183 cm"−"1) in FT-IR spectra illustrates the presence of polymer. Surface morphology reveals the presence of array of particles encapsulated by the polymer. - Highlights: • Composites having polymer, barium titanate and hexaferrite have been successfully prepared. • Effective radiation absorption and losses have been achieved. • Magnetic properties have made an impact on shielding effectiveness.

  14. Radiation losses in microwave K{sub u} region by conducting pyrrole/barium titanate and barium hexaferrite based nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Talwinder [Department of Physics, Lovely Professional University, Phagwara 144411 (India); Kumar, Sachin [Department of Chemistry, Guru Nanak Dev University, Amritsar 143005 (India); Narang, S.B. [Department of Electronics Technology, Guru Nanak Dev University, Amritsar 143005 (India); Srivastava, A.K., E-mail: srivastava_phy@yahoo.co.in [Department of Physics, Lovely Professional University, Phagwara 144411 (India)

    2016-12-15

    Nanocomposites of substituted barium hexaferrite and barium titanate embedded in a polymer were synthesized via emulsion polymerization. The study was performed by using X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, electron spin resonance spectroscopy, a vibrating sample magnetometer and a vector network analyzer. It is found that maximum radiation loss occur at 16.09 GHz (−14.23 dB) frequency owing to the combined effect of conducting polymer, suitable dielectric and magnetic material. This suggests that prepared material is suitable for radiation losses. Micro structural study reveals the presence of all the phases of the compounds comprises composite. Benzene ring absorption band (at 1183 cm{sup −1}) in FT-IR spectra illustrates the presence of polymer. Surface morphology reveals the presence of array of particles encapsulated by the polymer. - Highlights: • Composites having polymer, barium titanate and hexaferrite have been successfully prepared. • Effective radiation absorption and losses have been achieved. • Magnetic properties have made an impact on shielding effectiveness.

  15. Study On The Effect Of Cooking Of Some Food Proteins By Short-Term Radiation (Microwave) On The Functions Of The Liver And Kidney In Albino Rats

    International Nuclear Information System (INIS)

    Al-Marzooq, M.A.

    2014-01-01

    Five groups of albino male rats, every group consist of seven rats, were used to study the effect of microwave proteins on liver, kidney functions and blood parameters. Control group was fed on 10% casein. The 2nd one was fed on 10% protein from microwave chicken. The 3rd one was fed on 10% protein from boiled chicken. The 4th one was fed on 10% protein from microwave kidney beans. The 5th one was fed on 10% protein from boiled kidney beans. The time of experiment was seven weeks. The biochemical parameters included (cholesterol, LDL, HDL, total lipids, triglyceride, SGOT, SGPT, ALP, creatinin, uric acid and amino acids). The group of rats fed on microwave chicken showed more increase in cholesterol level than the group fed on boiled chicken. The group fed on microwave kidney beans showed decrease in cholesterol level. The group fed on microwave chicken showed decrease in HDL and increase in LDL. The highest activity of SGOT was shown in group fed on microwave kidney beans followed by the group fed on microwave chicken. The groups fed on boiled kidney beans and boiled chicken proteins showed significant increase in SGPT activity. The group fed on boiled kidney beans have the highest activity of ALP enzyme; but the group fed on microwave chicken showed increase in the activity of ALP enzyme compared to the control group. The feeding of microwave chicken leads to increase in creatinine and uric acid levels in comparison to the control group. Microwave cooking leads to little increase in all amino acids in comparison to the control group

  16. Thermal microwave states acting on a superconducting qubit

    Energy Technology Data Exchange (ETDEWEB)

    Goetz, Jan; Mueting, Miriam; Haeberlein, Max; Wulschner, Friedrich; Fischer, Michael; Deppe, Frank; Fedorov, Kirill; Huebl, Hans [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, 85748 Garching (Germany); Physik-Department, TU Muenchen, 85748 Garching (Germany); Xie, Edwar; Eder, Peter; Deppe, Frank; Gross, Rudolf [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, 85748 Garching (Germany); Physik-Department, TU Muenchen, 85748 Garching (Germany); Nanosystems Initiative Munich (NIM), Schellingstrasse 4, 80799 Muenchen (Germany); Marx, Achim [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, 85748 Garching (Germany)

    2016-07-01

    We analyze the influence of broadband thermal states in the microwave regime on the coherence properties of a superconducting (transmon) qubit coupled to a transmission line resonator. We generate the thermal states inside the resonator by heating a 30 dB attenuator to emit blackbody radiation into a transmission line. In the absence of thermal fluctuations, the qubit coherence time is limited by relaxation. We find that the relaxation rate is almost unaffected by the presence of a thermal field inside the resonator. However, such states induce significant dephasing which increases quadratically with the number of thermal photons, whereas for a coherent population of the resonator, the increase shows a linear behavior. These results confirm the different photon statistics, being Poissonian for a coherent population and super-Poissonian for a thermal population of the resonator.

  17. Application of microwave to drying and blanching of tomatoes

    International Nuclear Information System (INIS)

    Ando, Y.; Orikasa, T.; Shiina, T.; Sotome, I.; Isobe, S.; Muramatsu, Y.; Tagawa, A.

    2010-01-01

    The applicability of microwave to the drying and blanching of tomatoes was examined. The changes of the drying rate and surface color were first measured and compared between drying by hot air (50degC) or microwave at three radiation powers. The drying rates using a microwave were higher than that using hot air. Both a constant-rate drying period and a falling-rate drying period were observed for each microwave radiation power. Compared to hot air drying, microwave drying resulted in an increase in lightness which is a preferable quality of tomatoes. Next, the changes in temperature, nutrients and surface color were measured and compared between blanching by microwave or boiling water. Microwave blanching required less time, resulted in higher retention of nutrients (ascorbic acid and lycopene) and caused less change in color in comparison with boiling water blanching. These results suggest that a microwave could be applied to drying and blanching tomatoes

  18. Cosmic microwave background at its twentieth anniversary

    International Nuclear Information System (INIS)

    Partridge, R.B.

    1986-01-01

    The role of cosmic microwave background radiation in cosmology is examined. The thermal spectrum, the large entropy in the universe, the large-scale isotropy of the radiation, and the small-scale isotropy or homogeneity of the radiation are analyzed in order to describe the properties of the universe. It is observed that the microwave background spectrum is thermal over a wide range, there is a significant detectable dipole anisotropy in the radiation, but no quadrupole anisotropy, and there is a high deree of radiation isotropy on angular scales between 1-5 degrees. 62 references

  19. Emitting recombination of BCl molecules with chlorine atoms, resulting from dissociation of boron trichloride molecules under action of pulse CO2-laser radiation

    International Nuclear Information System (INIS)

    Nikonorov, A.P.; Moskvitina, E.N.; Kuzyakov, Yu.Ya.; Stepanov, P.I.

    1983-01-01

    Luminescence in BCl 3 is investigated. The results of measurements of gas temperature, BCl molecules concentration, and luminescence absolute intensity at boron trichloride presure of 40 mm pH and density of laser pulse energy from 1.7 up to 4.0 J/cm 2 are obtained. Nature of uninterrupted spectrum is considered. It is established that luminescence appearing in the BCl 3 under action of pulse CO 2 -laser is caused by reaction of emitting recombination of BCl molecules with chlorine atoms. Rate constant of this reaction in the range of 2300-3100 K is determined

  20. Evaluation of the Effect of Radiofrequency Radiation Emitted From Wi-Fi Router and Mobile Phone Simulator on the Antibacterial Susceptibility of Pathogenic Bacteria Listeria monocytogenes and Escherichia coli.

    Science.gov (United States)

    Taheri, M; Mortazavi, S M J; Moradi, M; Mansouri, S; Hatam, G R; Nouri, F

    2017-01-01

    Mobile phones and Wi-Fi radiofrequency radiation are among the main sources of the exposure of the general population to radiofrequency electromagnetic fields (RF-EMF). Previous studies have shown that exposure of microorganisms to RF-EMFs can be associated with a wide spectrum of changes ranged from the modified bacterial growth to the alterations of the pattern of antibiotic resistance. Our laboratory at the nonionizing department of the Ionizing and Non-ionizing Radiation Protection Research Center has performed experiments on the health effects of exposure to animal models and humans to different sources of electromagnetic fields such as cellular phones, mobile base stations, mobile phone jammers, laptop computers, radars, dentistry cavitrons, magnetic resonance imaging, and Helmholtz coils. On the other hand, we have previously studied different aspects of the challenging issue of the ionizing or nonionizing radiation-induced alterations in the susceptibility of microorganisms to antibiotics. In this study, we assessed if the exposure to 900 MHz GSM mobile phone radiation and 2.4 GHz radiofrequency radiation emitted from common Wi-Fi routers alters the susceptibility of microorganisms to different antibiotics. The pure cultures of Listeria monocytogenes and Escherichia coli were exposed to RF-EMFs generated either by a GSM 900 MHz mobile phone simulator and a common 2.4 GHz Wi-Fi router. It is also shown that exposure to RF-EMFs within a narrow level of irradiation (an exposure window) makes microorganisms resistant to antibiotics. This adaptive phenomenon and its potential threats to human health should be further investigated in future experiments. Altogether, the findings of this study showed that exposure to Wi-Fi and RF simulator radiation can significantly alter the inhibition zone diameters and growth rate for L monocytogenes and E coli. These findings may have implications for the management of serious infectious diseases.

  1. XPS and FTIR spectroscopic study on microwave treated high phosphorus iron ore

    International Nuclear Information System (INIS)

    Omran, Mamdouh; Fabritius, Timo; Elmahdy, Ahmed M.; Abdel-Khalek, Nagui A.; El-Aref, Mortada; Elmanawi, Abd El-Hamid

    2015-01-01

    Highlights: • The effect of microwave radiation on structure and chemical state of high phosphorus iron ore was studied. • FTIR analyses showed that after microwave radiation the functional chemical groups of phosphorus bearing minerals (fluorapatite) dissociated. • High resolution XPS analyses of Fe 2p peaks showed that after microwave radiation a portion of Fe(+III) was reduced to Fe(+II). • Microwave radiation had a positive effect on the magnetic properties of iron oxide, through formation of ferromagnetic phases. - Abstract: A growing interest in microwave heating has emerged recently. Several potential microwave applications regarding minerals’ processing have been investigated. This paper investigates the effect of microwave radiation on Egyptian high phosphorus iron ore. Three different iron ore samples have varying Fe 2 O 3 and P 2 O 5 contents and mineralogical textures were studied. A comparative study has been carried out between untreated and microwave treated iron ore. XRD and FTIR analyses showed that after microwave radiation the crystallinity of iron bearing minerals (hematite) increased, while the functional chemical groups of phosphorus bearing minerals (fluorapatite) and other gangues dissociated. High resolution XPS analyses of Fe 2p peaks showed that after microwave radiation a portion of Fe(+III) was reduced to Fe(+II). This means that after microwave radiation iron oxide (hematite, Fe 3+ ) transformed into more magnetic phase. The results indicated that microwave radiation had a positive effect on the magnetic properties of iron oxide, through formation of ferromagnetic phases

  2. Errors and limits in the determination of plasma electron density by measuring the absolute values of the emitted continuum radiation intensity

    International Nuclear Information System (INIS)

    Bilbao, L.; Bruzzone, H.; Grondona, D.

    1994-01-01

    The reliable determination of a plasma electron structure requires a good knowledge of the errors affecting the employed technique. A technique based on the measurements of the absolute light intensity emitted by travelling plasma structures in plasma focus devices has been used, but it can be easily modified to other geometries and even to stationary plasma structures with time-varying plasma densities. The purpose of this work is to discuss in some detail the errors and limits of this technique. Three separate errors are shown: the minimum size of the density structure that can be resolved, an overall error in the measurements themselves, and an uncertainty in the shape of the density profile. (author)

  3. Global Warming and the Microwave Background

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2009-04-01

    Full Text Available In the work, the importance of assigning the microwave background to the Earth is ad- dressed while emphasizing the consequences for global climate change. Climate mod- els can only produce meaningful forecasts when they consider the real magnitude of all radiative processes. The oceans and continents both contribute to terrestrial emis- sions. However, the extent of oceanic radiation, particularly in the microwave region, raises concerns. This is not only since the globe is covered with water, but because the oceans themselves are likely to be weaker emitters than currently believed. Should the microwave background truly be generated by the oceans of the Earth, our planet would be a much less efficient emitter of radiation in this region of the electromagnetic spectrum. Furthermore, the oceans would appear unable to increase their emissions in the microwave in response to temperature elevation, as predicted by Stefan’s law. The results are significant relative to the modeling of global warming.

  4. Recent developments in white light emitting diodes

    Science.gov (United States)

    Lohe, P. P.; Nandanwar, D. V.; Belsare, P. D.; Moharil, S. V.

    2018-05-01

    because they can emit visible light strongly under blue light irradiation. These are chemically, thermally and mechanically stable materials with high efficiency to down convert blue radiation into green and red. Efficient white light can be generated by coating these phosphors on blue LED.CRI of white emitting LED lamp can be improved significantly if green and red emitting phosphors are coated on efficient blue emitting LED chips. In this approach CRI will be maintained if appropriate combination of red, green along with blue emission is used. This article reviews some recent developments in phosphors for white light emitting diodes.

  5. Microwave based method of monitoring crack formation

    International Nuclear Information System (INIS)

    Aman, Sergej; Aman, Alexander; Majcherek, Soeren; Hirsch, Soeren; Schmidt, Bertram

    2014-01-01

    The formation of cracks in glass particles was monitored by application of linearly polarized microwaves. The breakage behavior of glass spheres coated with a thin gold layer of about 50 nm, i.e. a thickness that is lower than the microwave penetration depth, was tested. In this way the investigation of fracture behavior of electronic circuits was simulated. A shielding current was induced in the gold layer by the application of microwaves. During the crack formation the distribution of this current changed abruptly and a scattered microwave signal appeared at the frequency of the incident microwaves. The time behavior of the scattered signal reflects the microscopic processes occurring during the fracture of the specimen. The duration of the increasing signal corresponds to the crack formation time in the tested specimen. This time was estimated as particle size divided by crack development speed in glass. An intense emission of electrons occurs during the formation of cracks. Due to this, coherent Thomson scattering of microwaves by emitted electrons becomes significant with a delay of a few microseconds after the initial phase of crack formation. In this time the intensity of the microwave signal increases. (paper)

  6. Advances in microwaves 8

    CERN Document Server

    Young, Leo

    2013-01-01

    Advances in Microwaves, Volume 8 covers the developments in the study of microwaves. The book discusses the circuit forms for microwave integrated circuits; the analysis of microstrip transmission lines; and the use of lumped elements in microwave integrated circuits. The text also describes the microwave properties of ferrimagnetic materials, as well as their interaction with electromagnetic waves propagating in bounded waveguiding structures. The integration techniques useful at high frequencies; material technology for microwave integrated circuits; specific requirements on technology for d

  7. Microwave power engineering applications

    CERN Document Server

    Okress, Ernest C

    2013-01-01

    Microwave Power Engineering, Volume 2: Applications introduces the electronics technology of microwave power and its applications. This technology emphasizes microwave electronics for direct power utilization and transmission purposes. This volume presents the accomplishments with respect to components, systems, and applications and their prevailing limitations in the light of knowledge of the microwave power technology. The applications discussed include the microwave heating and other processes of materials, which utilize the magnetron predominantly. Other applications include microwave ioni

  8. Development of radiation detectors based on KMgF{sub 3}:Tb nano crystals synthesized by microwave; Desarrollo de detectores de radiacion basados en nanocristales de KMgF{sub 3}:Tb sintetizados por microondas

    Energy Technology Data Exchange (ETDEWEB)

    Herrero C, R.; Villicana M, M.; Garcia S, L.; Custodio C, M. A. [Universidad Michoacana de San Nicolas de Hidalgo, Facultad de Ingenieria Quimica, Francisco J. Mujica s/n, Ciudad Universitaria, Col. Felicitas del Rio, 58030 Morelia, Michoacan (Mexico); Gonzalez M, P. R.; Mendoza A, D., E-mail: laura_garciasalinas@yahoo.com.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2015-10-15

    The development of new thermoluminescent (Tl) materials of the size of KMgF{sub 3}:Tb nano crystals by microwave technique is a new alternative for obtaining new radiation detectors (dosimeters) for environmental dosimetry, personal, clinical, research and industry. This technique requires the preparation of the precursors of magnesium trifluoro acetates Mg(CF{sub 3}COO){sub 2} and potassium K(CF{sub 3}COO), finally the synthesis of KMgF{sub 3}:Tb is realized via microwave. The synthesis was carried out in a microwave reactor mono wave 300 Anton-Paar. Trifluoro acetates are introduced into the reactor at a ratio of 1:1 mmol under inert atmosphere. The product was collected for centrifugation, washed several times with ethanol and dried at 60 degrees C for 10 h. The KMgF{sub 3} obtained without doping and doped with Tb{sup +3} ions were subjected to heat treatment at high temperatures for different lengths of time for their sensitization, the samples treated at 700 degrees C were those showing better Tl signal to be irradiated with gammas of {sup 60}Co. The characterization of the obtained materials was carried out by X-ray diffraction, scanning electron microscopy and thermogravimetric analysis. (Author)

  9. Nuclear-microwave-electric propulsion

    International Nuclear Information System (INIS)

    Nordley, G.D.; Brown, W.C.

    1986-01-01

    Electric propulsion can move more mass through space than chemical propulsion by virtue of the higher exhaust velocities achieved by electric propulsion devices. This performance is achieved at the expense of very heavy power sources or very long trip times, which in turn create technical and economic penalties of varying severity. These penalties include: higher operations costs, delayed availability of the payload, and increased exposure to Van Allen Belt radiation. It is proposed to reduce these penalties by physically separating the power source from the propulsion and use microwave energy beaming technology, recently explored and partially developed/tested for Solar Power Satellite concept studies, as an extension cord. This paper summarizes the state of the art of the technology needed for space based beam microwave power cost/performance trades involved with the use beamed microwave/electric propulsion for some typical orbit transfer missions and offers some suggestions for additional work

  10. Compact torus compression of microwaves

    International Nuclear Information System (INIS)

    Hewett, D.W.; Langdon, A.B.

    1985-01-01

    The possibility that a compact torus (CT) might be accelerated to large velocities has been suggested by Hartman and Hammer. If this is feasible one application of these moving CTs might be to compress microwaves. The proposed mechanism is that a coaxial vacuum region in front of a CT is prefilled with a number of normal electromagnetic modes on which the CT impinges. A crucial assumption of this proposal is that the CT excludes the microwaves and therefore compresses them. Should the microwaves penetrate the CT, compression efficiency is diminished and significant CT heating results. MFE applications in the same parameters regime have found electromagnetic radiation capable of penetrating, heating, and driving currents. We report here a cursory investigation of rf penetration using a 1-D version of a direct implicit PIC code

  11. Radiation-induced biologic bystander effect elicited in vitro by targeted radiopharmaceuticals labeled with alpha-, beta-, and auger electron-emitting radionuclides.

    Science.gov (United States)

    Boyd, Marie; Ross, Susan C; Dorrens, Jennifer; Fullerton, Natasha E; Tan, Ker Wei; Zalutsky, Michael R; Mairs, Robert J

    2006-06-01

    Recent studies have shown that indirect effects of ionizing radiation may contribute significantly to the effectiveness of radiotherapy by sterilizing malignant cells that are not directly hit by the radiation. However, there have been few investigations of the importance of indirect effects in targeted radionuclide treatment. Our purpose was to compare the induction of bystander effects by external beam gamma-radiation with those resultant from exposure to 3 radiohaloanalogs of metaiodobenzylguanidine (MIBG): (131)I-MIBG (low-linear-energy-transfer [LET] beta-emitter), (123)I-MIBG (potentially high-LET Auger electron emitter), and meta-(211)At-astatobenzylguanidine ((211)At-MABG) (high-LET alpha-emitter). Two human tumor cell lines-UVW (glioma) and EJ138 (transitional cell carcinoma of bladder)-were transfected with the noradrenaline transporter (NAT) gene to enable active uptake of MIBG. Medium from cells that accumulated the radiopharmaceuticals or were treated with external beam radiation was transferred to cells that had not been exposed to radioactivity, and clonogenic survival was determined in donor and recipient cultures. Over the dose range 0-9 Gy of external beam radiation of donor cells, 2 Gy caused 30%-40% clonogenic cell kill in recipient cultures. This potency was maintained but not increased by higher dosage. In contrast, no corresponding saturation of bystander cell kill was observed after treatment with a range of activity concentrations of (131)I-MIBG, which resulted in up to 97% death of donor cells. Cellular uptake of (123)I-MIBG and (211)At-MABG induced increasing recipient cell kill up to levels that resulted in direct kill of 35%-70% of clonogens. Thereafter, the administration of higher activity concentrations of these high-LET emitters was inversely related to the kill of recipient cells. Over the range of activity concentrations examined, neither direct nor indirect kill was observed in cultures of cells not expressing the NAT and, thus

  12. Radiation Segmentectomy versus TACE Combined with Microwave Ablation for Unresectable Solitary Hepatocellular Carcinoma Up to 3 cm: A Propensity Score Matching Study.

    Science.gov (United States)

    Biederman, Derek M; Titano, Joseph J; Bishay, Vivian L; Durrani, Raisa J; Dayan, Etan; Tabori, Nora; Patel, Rahul S; Nowakowski, Francis S; Fischman, Aaron M; Kim, Edward

    2017-06-01

    Purpose To compare the outcomes of radiation segmentectomy (RS) and transarterial chemoembolization (TACE) combined with microwave ablation (MWA) in the treatment of unresectable solitary hepatocellular carcinoma (HCC) up to 3 cm. Materials and Methods This retrospective study was approved by the institutional review board, and the requirement to obtain informed consent was waived. From January 2010 to June 2015, a total of 417 and 235 consecutive patients with HCC underwent RS and TACE MWA, respectively. A cohort of 121 patients who had not previously undergone local-regional therapy (RS, 41; TACE MWA, 80; mean age, 65.4 years; 84 men [69.4%]) and who had solitary HCC up to 3 cm without vascular invasion or metastasis was retrospectively identified. Outcomes analyzed included procedure-related complications, laboratory toxicity levels, imaging response, time to progression (TTP), 90-day mortality, and survival. Propensity score matching was conducted by using a nearest-neighbor algorithm (1:1) to account for pretreatment clinical, laboratory, and imaging covariates. Postmatching statistical analysis was performed with conditional logistic regression for binary outcomes and the stratified log-rank test for time-dependent outcomes. Results Before matching, the complication rate was 8.9% and 4.9% in the TACE MWA and RS groups, respectively (P = .46). The overall complete response (CR) rate was 82.9% for RS and 82.5% for TACE MWA (odds ratio, 1.0; 95% confidence interval [CI]: 0.4, 2.8; P = .95). There were 41 (RS, 11; TACE MWA, 30) instances of progression occurring after an initial CR, of which 10 (24%) were classified as target progression (RS, one; TACE MWA, nine). Median overall TTP was 11.1 months (95% CI: 8.8 months, 25.6 months) in the RS group and 12.1 months (95% CI: 7.7 months, 19.1 months) in the TACE MWA group (P > .99). After matching, the overall CR rate (P = .94), TTP (P = .83), and overall survival (P > .99) were not significantly different between

  13. Top emitting white OLEDs

    Energy Technology Data Exchange (ETDEWEB)

    Freitag, Patricia; Luessem, Bjoern; Leo, Karl [Technische Universitaet Dresden, Institut fuer Angewandte Photophysik, George-Baehr-Strasse 1, 01069 Dresden (Germany)

    2009-07-01

    Top emitting organic light emitting diodes (TOLEDs) provide a number of interesting opportunities for new applications, such as the opportunity to fabricate ITO-free devices by using opaque substrates. This makes it possible to manufacture low cost OLEDs for signage and lighting applications. A general top emitting device consists of highly reflecting metal contacts as anode and semitransparent cathode, the latter one for better outcouling reasons. In between several organic materials are deposited as charge transporting, blocking, and emission layers. Here, we show a top emitting white organic light emitting diode with silver electrodes arranged in a p-i-n structure with p- and n-doped charge transport layers. The centrical emission layer consists of two phosphorescent (red and green) and one fluorescent (blue) emitter systems separated by an ambipolar interlayer to avoid mutual exciton quenching. By adding an additional dielectric capping layer on top of the device stack, we achieve a reduction of the strong microcavity effects which appear due to the high reflection of both metal electrodes. Therefore, the outcoupled light shows broad and nearly angle-independent emission spectra, which is essential for white light emitting diodes.

  14. Cytogenetic Damages Induced by Chronic Exposure to Microwave Non-Ionizing Radiofrequency Fields

    Directory of Open Access Journals (Sweden)

    Boris Đinđić

    2013-12-01

    Full Text Available Non-ionizing radiation has a significant and positive impact on modern society through a number of uses. There is increasing public concern regarding the health risks of radio-frequency (RF radiation, particularly that produced by mobile phones. Concern regarding the potential risks of exposure to EMFs has led to many epidemiological investigations, but the effects of EMF exposure on human and other mammalian cells are still unclear. One of the most frequently asked questions about the effects of microwave radiation on biological systems is whether they produce genotoxic effects and could be there a possible link with oncogenic processes. It is most difficult to get accurate and reproducible results for the studies that tell us most about the effects of EMF on humans. Based on some “weak” evidence suggesting an association between exposure to radiofrequency fields (RF emitted from mobile phones and two types of brain cancer, glioma and acoustic neuroma, the International Agency for Research on Cancer has classified RF as ‘possibly carcinogenic to humans’ in group 2B. Literature results suggest that pulsed microwaves from working environment can be the cause of genetic and cell alterations. Taken together, the increased frequency of DNA damages, increased intensity of oxydative stress and production of reactive oxygen species as well as prolonged disruption in DNA repair mechanisms could be possible mechanisms for microwave induced cytogenetic damages even at low-level electromagnetic fields. Although there were contradictory results about harmful effects of electromagnetic fields we recommend that the mobile phone should be kept as far as possible from the body during conversations and also during usual daily activities to reduce the absorption of radiation by cells. In addition, the appropriate intake of antioxidant-rich food or drugs may be helpful for preventing the genotoxic effects that could be caused by mobile phone use.

  15. Microwave-assisted grinding of metallurgical coke

    International Nuclear Information System (INIS)

    Ruisanchez, E.; Juarez-Perez, E. J.; Arenillas, A.; Bermudez, J. M.; Menendez, J. A.

    2014-01-01

    Metallurgical cokes are composed of graphitic carbon (s2p2) and different inorganic compounds with very different capacities to absorb microwave radiation. Moreover, due to the electric conductivity shown by the metallurgical cokes, microwave radiation produces electric arcs or microplasmas, which gives rise to hot spots. Therefore, when these cokes are irradiated with microwaves some parts of the particle experiment a rapid heating, while some others do not heat at all. As a result of the different expansion and stress caused by thermal the shock, small cracks and micro-fissures are produced in the particle. The weakening of the coke particles, and therefore an improvement of its grind ability, is produced. This paper studies the microwave-assisted grinding of metallurgical coke and evaluates the grinding improvement and energy saving. (Author)

  16. Effects of UV and microwave radiation on biological material. A bibliographic survey on biochemical effects. Pt. 1. Der Einfluss von UV- und Mikrowellenstrahlung auf biologisches Material. Eine Literaturstudie ueber die biochemischen Wirkungen. T. 1

    Energy Technology Data Exchange (ETDEWEB)

    Fielitz, J; Boegl, W; Stockhausen, K; Kossel, F

    1977-01-01

    For the present study, ten publications on the effect of UV radiation were analyzed. In vitro tests were carried out with one biological substance and seven different human or animal organs and biocytocultures. In vivo, three bacterial strains were irradiated and four irradiation experiments were carried out on mice. As to the effect of microwave radiation, eleven publications were analyzed. In vitro tests were carried out with one biological substance and three animal organs. In vivo, one bacterial strain was irradiated and eight irradiation experiments were carried out on different types of animals. The study's aim was to obtain a survey on biochemical changes of the organisms. Phenomenological changes were given only when the corresponding articles contained further investigation results. Behavioral changes were not taken into account. The results published by the authors of the original papers were compiled in a kind of dictionary. All relevant data are listed in a defined order.

  17. Rapid degradation of azo dye Direct Black BN by magnetic MgFe{sub 2}O{sub 4}-SiC under microwave radiation

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Jia; Yang, Shaogui, E-mail: yangsg@nju.edu.cn; Li, Na; Meng, Lingjun; Wang, Fei; He, Huan; Sun, Cheng

    2016-08-30

    Highlights: • MgFe{sub 2}O{sub 4}-SiC was first successfully synthesized. • MgFe{sub 2}O{sub 4}-SiC attained the maximum absorbing value of 13.32 dB at 2.57 GHz, which reached extremely high RL value at low frequency range. • Fast decolorization and high TOC removal of azo dye Direct Black BN with complicated structure could occur with MgFe{sub 2}O{sub 4}-SiC under MW radiation. • MgFe{sub 2}O{sub 4}-SiC had better MW absorbing property and higher MW catalytic activity than MnFe{sub 2}O{sub 4}-SiC under the same condition. • MgFe{sub 2}O{sub 4}-SiC was of practical use in the wastewater treatment. - Abstract: A novel microwave (MW) catalyst, MgFe{sub 2}O{sub 4} loaded on SiC (MgFe{sub 2}O{sub 4}-SiC), was successfully synthesized by sol-gel method, and pure MgFe{sub 2}O{sub 4} was used as reference. The MgFe{sub 2}O{sub 4} and MgFe{sub 2}O{sub 4}-SiC catalysts were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), N{sub 2} adsorption analyzer (BET specific surface area), X-ray photoelectron spectroscopy (XPS). The electromagnetic parameters of the prepared catalysts were measured by vector network analyzer. The reflection loss (RL) based on the electromagnetic parameters calculated in Matlab showed MgFe{sub 2}O{sub 4}-SiC attained the maximum absorbing value of 13.32 dB at 2.57 GHz, which reached extremely high RL value at low frequency range, revealing the excellent MW absorption property of MgFe{sub 2}O{sub 4}-SiC. MW-induced degradation of Direct Black BN (DB BN) over as-synthesized MgFe{sub 2}O{sub 4}-SiC indicated that degradation efficiency of DB BN (20 mg L{sup −1}) in 5 min reached 96.5%, the corresponding TOC removal was 65%, and the toxicity of DB BN after degradation by MgFe{sub 2}O{sub 4}-SiC obviously decreased. The good stability and applicability of MgFe{sub 2}O{sub 4}-SiC on the degradation process were also discovered. Moreover, the ionic chromatogram during degradation

  18. Radiation

    International Nuclear Information System (INIS)

    2013-01-01

    The chapter one presents the composition of matter and atomic theory; matter structure; transitions; origin of radiation; radioactivity; nuclear radiation; interactions in decay processes; radiation produced by the interaction of radiation with matter

  19. Crystallization method employing microwave radiation

    Energy Technology Data Exchange (ETDEWEB)

    Chu, P; Dwyer, F G; Vartuli, J C

    1992-12-01

    This invention relates to a method of crystallizing materials from aqueous crystallization media. Zeolite materials, both natural and synthetic, have been demonstrated in the past to have catalytic properties for various types of hydrocarbon conversion. Certain zeolitic materials are ordered, porous crystalline metallosilicates having a definite crystalline structure as determined by X-ray diffraction within which there are a number of smaller cavities which may be interconnected by a number of still smaller channels or pores. These cavities and pores are uniform in size within a specific zeolite material. Since the dimensions of these pores are such as to accept for adsorption molecules of certain dimensions while rejecting those of large dimensions, these materials have come to be known as molecular sieves and are utilized in a variety of ways to take advantage of these properties. (author). 3 tabs.

  20. Crystallization method employing microwave radiation

    International Nuclear Information System (INIS)

    Chu, P.; Dwyer, F.G.; Vartuli, J.C.

    1992-01-01

    This invention relates to a method of crystallizing materials from aqueous crystallization media. Zeolite materials, both natural and synthetic, have been demonstrated in the past to have catalytic properties for various types of hydrocarbon conversion. Certain zeolitic materials are ordered, porous crystalline metallosilicates having a definite crystalline structure as determined by X-ray diffraction within which there are a number of smaller cavities which may be interconnected by a number of still smaller channels or pores. These cavities and pores are uniform in size within a specific zeolite material. Since the dimensions of these pores are such as to accept for adsorption molecules of certain dimensions while rejecting those of large dimensions, these materials have come to be known as molecular sieves and are utilized in a variety of ways to take advantage of these properties. (author). 3 tabs

  1. The Cosmic Microwave Background Anisotropy

    Science.gov (United States)

    Bennett, C. L.

    1994-12-01

    The properties of the cosmic microwave background radiation provide unique constraints on the history and evolution of the universe. The first detection of anisotropy of the microwave radiation was reported by the COBE Team in 1992, based on the first year of flight data. The latest analyses of the first two years of COBE data are reviewed in this talk, including the amplitude of the microwave anisotropy as a function of angular scale and the statistical nature of the fluctuations. The two-year results are generally consistent with the earlier first year results, but the additional data allow for a better determination of the key cosmological parameters. In this talk the COBE results are compared with other observational anisotropy results and directions for future cosmic microwave anisotropy observations will be discussed. The National Aeronautics and Space Administration/Goddard Space Flight Center (NASA/GSFC) is responsible for the design, development, and operation of the Cosmic Background Explorer (COBE). Scientific guidance is provided by the COBE Science Working Group.

  2. Microfabricated Microwave-Integrated Surface Ion Trap

    Science.gov (United States)

    Revelle, Melissa C.; Blain, Matthew G.; Haltli, Raymond A.; Hollowell, Andrew E.; Nordquist, Christopher D.; Maunz, Peter

    2017-04-01

    Quantum information processing holds the key to solving computational problems that are intractable with classical computers. Trapped ions are a physical realization of a quantum information system in which qubits are encoded in hyperfine energy states. Coupling the qubit states to ion motion, as needed for two-qubit gates, is typically accomplished using Raman laser beams. Alternatively, this coupling can be achieved with strong microwave gradient fields. While microwave radiation is easier to control than a laser, it is challenging to precisely engineer the radiated microwave field. Taking advantage of Sandia's microfabrication techniques, we created a surface ion trap with integrated microwave electrodes with sub-wavelength dimensions. This multi-layered device permits co-location of the microwave antennae and the ion trap electrodes to create localized microwave gradient fields and necessary trapping fields. Here, we characterize the trap design and present simulated microwave performance with progress towards experimental results. This research was funded, in part, by the Office of the Director of National Intelligence (ODNI), Intelligence Advanced Research Projects Activity (IARPA).

  3. A DSM-based “2.0” System for Human Intervention Planning and Scheduling in Facilities Emitting Ionizing Radiations

    CERN Document Server

    Baudin, M; De Jonghe, J

    2012-01-01

    To efficiently and safely plan, schedule and control its interventions in underground facilities, which are subject to ionizing radiations, CERN is currently developing a collaborative Web-based system. A similar project for maintenance management is also under way. On top of presenting their key requirements, this paper shows how the implementation of DSM can enhance a so-called Web 2.0 or collaborative dimension by bringing an intuitive and fair way of taking the dependencies between several activities into account. It is also discussed that the incoherencies brought in DSM by collaborative use (for instance regarding the time intervals) can be addressed by enlarging the binary DSM span of dependencies to ones of the Allen’s interval algebra or at least a subset of its dependencies.

  4. Aspects of microwave-heating uniformity

    International Nuclear Information System (INIS)

    Ginsberg, T.; Makowitz, H.

    1983-01-01

    Interest has been shown in the field of nuclear reactor safety in the use of microwave heating to simulate the nuclear heat source. The objective of the investigation reported here was to evaluate the usefulness of microwave dielectric heating as a simulator of the nuclear heat source in experiments which simulate the process of boiling of molten mixtures of nuclear fuel and steel. This paper summarizes the results of studies of several aspects of energy deposition in dielectric liquid samples which are exposed to microwave radiation

  5. General Purpose Fortran Program for Discrete-Ordinate-Method Radiative Transfer in Scattering and Emitting Layered Media: An Update of DISORT

    Science.gov (United States)

    Tsay, Si-Chee; Stamnes, Knut; Wiscombe, Warren; Laszlo, Istvan; Einaudi, Franco (Technical Monitor)

    2000-01-01

    This update reports a state-of-the-art discrete ordinate algorithm for monochromatic unpolarized radiative transfer in non-isothermal, vertically inhomogeneous, but horizontally homogeneous media. The physical processes included are Planckian thermal emission, scattering with arbitrary phase function, absorption, and surface bidirectional reflection. The system may be driven by parallel or isotropic diffuse radiation incident at the top boundary, as well as by internal thermal sources and thermal emission from the boundaries. Radiances, fluxes, and mean intensities are returned at user-specified angles and levels. DISORT has enjoyed considerable popularity in the atmospheric science and other communities since its introduction in 1988. Several new DISORT features are described in this update: intensity correction algorithms designed to compensate for the 8-M forward-peak scaling and obtain accurate intensities even in low orders of approximation; a more general surface bidirectional reflection option; and an exponential-linear approximation of the Planck function allowing more accurate solutions in the presence of large temperature gradients. DISORT has been designed to be an exemplar of good scientific software as well as a program of intrinsic utility. An extraordinary effort has been made to make it numerically well-conditioned, error-resistant, and user-friendly, and to take advantage of robust existing software tools. A thorough test suite is provided to verify the program both against published results, and for consistency where there are no published results. This careful attention to software design has been just as important in DISORT's popularity as its powerful algorithmic content.

  6. Isotherms clustering in cosmic microwave background

    International Nuclear Information System (INIS)

    Bershadskii, A.

    2006-01-01

    Isotherms clustering in cosmic microwave background (CMB) has been studied using the 3-year WMAP data on cosmic microwave background radiation. It is shown that the isotherms clustering could be produced by the baryon-photon fluid turbulence in the last scattering surface. The Taylor-microscale Reynolds number of the turbulence is estimated directly from the CMB data as Re λ ∼10 2

  7. Intense microwave pulse propagation through gas breakdown plasmas in a waveguide

    International Nuclear Information System (INIS)

    Byrne, D.P.

    1986-01-01

    High-power microwave pulse-compression techniques are used to generate 2.856 GHz pulses which are propagated in a TE 10 mode through a gas filled section of waveguide, where the pulses interact with self-generated gas-breakdown plasmas. Pulse envelopes transmitted through the plasmas, with duration varying from 2 ns to greater than 1 μs, and peak powers of a few kW to nearly 100 MW, are measured as a function of incident pulse and gas pressure for air, nitrogen, and helium. In addition, the spatial and temporal development of the optical radiation emitted by the breakdown plasmas are measured. For transmitted pulse durations ≥ 100 ns, good agreement is found with both theory and existing measurements. For transmitted pulse duration as short as 2 ns (less than 10 rf cycles), a two-dimensional model is used in which the electrons in the plasma are treated as a fluid whose interactions with the microwave pulse are governed by a self-consistent set of fluid equations and Maxwell's equations for the electromagnetic field. The predictions of this model for air are compared with the experimental results over a pressure range of 0.8 torr to 300 torr. Good agreement is obtained above about 1 torr pressure, demonstrating that microwave pulse propagation above the breakdown threshold can be accurately modeled on this time scale. 63 refs., 44 figs., 2 tabs

  8. Practical microwave electron devices

    CERN Document Server

    Meurant, Gerard

    2013-01-01

    Practical Microwave Electron Devices provides an understanding of microwave electron devices and their applications. All areas of microwave electron devices are covered. These include microwave solid-state devices, including popular microwave transistors and both passive and active diodes; quantum electron devices; thermionic devices (including relativistic thermionic devices); and ferrimagnetic electron devices. The design of each of these devices is discussed as well as their applications, including oscillation, amplification, switching, modulation, demodulation, and parametric interactions.

  9. Effects of lignocellulosic composition and microwave power level on the gaseous product of microwave pyrolysis

    International Nuclear Information System (INIS)

    Huang, Yu-Fong; Chiueh, Pei-Te; Kuan, Wen-Hui; Lo, Shang-Lien

    2015-01-01

    Agricultural residues are abundant resources to produce renewable energy and valuable chemicals. This study focused on the effects of lignocellulosic composition and microwave power level on the gaseous product of microwave pyrolysis of agricultural residues. When agricultural residues were under microwave radiation within 10 min, the maximum temperatures of approximately 320, 420, and 530 °C were achieved at the microwave power levels of 300, 400, and 500 W, respectively. Gas yield increased with increasing microwave power level, whereas solid and liquid yields decreased. Besides, gaseous products with higher H 2 content and higher calorific values can be obtained at higher microwave power levels. In addition to microwave power level, lignocellulosic composition was also an important factor. H 2 and CO 2 yields increased with increasing hemicellulose content, whereas CH 4 and CO yields increased with increasing cellulose content. Four empirical equations were derived to present the contributions of lignocellulosic materials to the yields of gaseous components. - Highlights: • About 530 °C was reached within 10 min at a microwave power level of 500 W. • Gas yield increased with increasing microwave power level. • A high correlation between hemicellulose content and either H 2 or CO 2 yield. • A high correlation between cellulose content and either CH 4 or CO yield. • Empirical equations depict contribution of lignocellulosic content to gas yield

  10. Low-cost microwave radiometry for remote sensing of soil moisture

    Science.gov (United States)

    Chikando, Eric Ndjoukwe

    2007-12-01

    Remote sensing is now widely regarded as a dominant means of studying the Earth and its surrounding atmosphere. This science is based on blackbody theory, which states that all objects emit broadband electromagnetic radiation proportional to their temperature. This thermal emission is detectable by radiometers---highly sensitive receivers capable of measuring extremely low power radiation across a continuum of frequencies. In the particular case of a soil surface, one important parameter affecting the emitted radiation is the amount of water content or, soil moisture. A high degree of precision is required when estimating soil moisture in order to yield accurate forecasting of precipitations and short-term climate variability such as storms and hurricanes. Rapid progress within the remote sensing community in tackling current limitations necessitates an awareness of the general public towards the benefits of the science. Information about remote sensing instrumentation and techniques remain inaccessible to many higher-education institutions due to the high cost of instrumentation and the current general inaccessibility of the science. In an effort to draw more talent within the field, more affordable and reliable scientific instrumentation are needed. This dissertation introduces the first low-cost handheld microwave instrumentation fully capable of surface soil moisture studies. The framework of this research is two-fold. First, the development of a low-cost handheld microwave radiometer using the well-known Dicke configuration is examined. The instrument features a super-heterodyne architecture and is designed following a microwave integrated circuit (MIC) system approach. Validation of the instrument is performed by applying it to various soil targets and comparing measurement results to gravimetric technique measured data; a proven scientific method for determining volumetric soil moisture content. Second, the development of a fully functional receiver RF front

  11. Application of high power microwave vacuum electron devices

    International Nuclear Information System (INIS)

    Ding Yaogen; Liu Pukun; Zhang Zhaochuan; Wang Yong; Shen Bin

    2011-01-01

    High power microwave vacuum electron devices can work at high frequency, high peak and average power. They have been widely used in military and civil microwave electron systems, such as radar, communication,countermeasure, TV broadcast, particle accelerators, plasma heating devices of fusion, microwave sensing and microwave heating. In scientific research, high power microwave vacuum electron devices are used mainly on high energy particle accelerator and fusion research. The devices include high peak power klystron, CW and long pulse high power klystron, multi-beam klystron,and high power gyrotron. In national economy, high power microwave vacuum electron devices are used mainly on weather and navigation radar, medical and radiation accelerator, TV broadcast and communication system. The devices include high power pulse and CW klystron, extended interaction klystron, traveling wave tube (TWT), magnetron and induced output tube (IOT). The state of art, common technology problems and trends of high power microwave vacuum electron devices are introduced in this paper. (authors)

  12. Microwave Frequency Multiplier

    Science.gov (United States)

    Velazco, J. E.

    2017-02-01

    High-power microwave radiation is used in the Deep Space Network (DSN) and Goldstone Solar System Radar (GSSR) for uplink communications with spacecraft and for monitoring asteroids and space debris, respectively. Intense X-band (7.1 to 8.6 GHz) microwave signals are produced for these applications via klystron and traveling-wave microwave vacuum tubes. In order to achieve higher data rate communications with spacecraft, the DSN is planning to gradually furnish several of its deep space stations with uplink systems that employ Ka-band (34-GHz) radiation. Also, the next generation of planetary radar, such as Ka-Band Objects Observation and Monitoring (KaBOOM), is considering frequencies in the Ka-band range (34 to 36 GHz) in order to achieve higher target resolution. Current commercial Ka-band sources are limited to power levels that range from hundreds of watts up to a kilowatt and, at the high-power end, tend to suffer from poor reliability. In either case, there is a clear need for stable Ka-band sources that can produce kilowatts of power with high reliability. In this article, we present a new concept for high-power, high-frequency generation (including Ka-band) that we refer to as the microwave frequency multiplier (MFM). The MFM is a two-cavity vacuum tube concept where low-frequency (2 to 8 GHz) power is fed into the input cavity to modulate and accelerate an electron beam. In the second cavity, the modulated electron beam excites and amplifies high-power microwaves at a frequency that is a multiple integer of the input cavity's frequency. Frequency multiplication factors in the 4 to 10 range are being considered for the current application, although higher multiplication factors are feasible. This novel beam-wave interaction allows the MFM to produce high-power, high-frequency radiation with high efficiency. A key feature of the MFM is that it uses significantly larger cavities than its klystron counterparts, thus greatly reducing power density and arcing

  13. STIR: Microwave Response of Carbon Nanotubes in Polymer Nanocomposite Welds

    Science.gov (United States)

    2016-01-28

    STIR: RDRL-ROE-M: Microwave Response of Carbon Nanotubes in Polymer Nanocomposite Welds Thrust 1 of the STIR project examines the heat response of...polymer composites loaded with carbon nanotubes (CNTs) to microwave irradiation. This involves (1) a study of how CNT loading affects dielectric...properties of polymer composites and (2) a study of how CNT loading affects the heating response to microwave radiation. Our hypothesis is that the

  14. Infrared Radiation and Blackbody Radiation

    OpenAIRE

    2005-01-01

    tut present graph Tutorial Presentation Graph Interactive Media Element This interactive tutorial covers the following: How infrared radiation was discovered., The regions of infrared radiation and their relations to temperature., The nature of blackbody radiation and Planck's radiation law., The relationship between temperature and the power emitted by radiation.The interactions in this tutorial include clicking to reveal new information, and questions that help students...

  15. Visible optical radiation generates bactericidal effect applicable for inactivation of health care associated germs demonstrated by inactivation of E. coli and B. subtilis using 405-nm and 460-nm light emitting diodes

    Science.gov (United States)

    Hönes, Katharina; Stangl, Felix; Sift, Michael; Hessling, Martin

    2015-07-01

    The Ulm University of Applied Sciences is investigating a technique using visible optical radiation (405 nm and 460 nm) to inactivate health-hazardous bacteria in water. A conceivable application could be point-of-use disinfection implementations in developing countries for safe drinking water supply. Another possible application field could be to provide sterile water in medical institutions like hospitals or dental surgeries where contaminated pipework or long-term disuse often results in higher germ concentrations. Optical radiation for disinfection is presently mostly used in UV wavelength ranges but the possibility of bacterial inactivation with visible light was so far generally disregarded. One of the advantages of visible light is, that instead of mercury arc lamps, light emitting diodes could be used, which are commercially available and therefore cost-efficient concerning the visible light spectrum. Furthermore they inherit a considerable longer life span than UV-C LEDs and are non-hazardous in contrast to mercury arc lamps. Above all there are specific germs, like Bacillus subtilis, which show an inactivation resistance to UV-C wavelengths. Due to the totally different deactivation mechanism even higher disinfection rates are reached, compared to Escherichia coli as a standard laboratory germ. By 460 nm a reduction of three log-levels appeared with Bacillus subtilis and a half log-level with Escherichia coli both at a dose of about 300 J/cm². By the more efficient wavelength of 405 nm four and a half log-levels are reached with Bacillus subtilis and one and a half log-level with Escherichia coli also both at a dose of about 300 J/cm². In addition the employed optical setup, which delivered a homogeneous illumination and skirts the need of a stirring technique to compensate irregularities, was an important improvement compared to previous published setups. Evaluated by optical simulation in ZEMAX® the designed optical element provided proven

  16. Radiation Hazards

    Science.gov (United States)

    1975-08-01

    persons having worked more than five years under conditions of low and medium microwave exposure. Three groups of leukocytot changes occur In persons...Medical Publis!Iers (0974) 189-195. 32. Baranski, S., P. Czer-,ki and S. Szinglgilski. Microwave effects on mitosis In vivo and in vitro. Genetica ...effect of 3-cm microwave radiation. Amer. J. Ph-ysiol. 20. (1961) 192- 194. 72. 0sipov2 Yu.A. The effect of VHF-HF under industrial conditions . Gig

  17. Microwave radiation absorption and Shubnikov-de Haas oscillations in semimetal InAs/GaSb/AlSb composite quantum wells

    Czech Academy of Sciences Publication Activity Database

    Mikhailova, M. P.; Veinger, A.I.; Kochman, I.V.; Semenikhin, P.V.; Kalinina, K.V.; Parfeniev, R.V.; Berezovets, V.A.; Safonchik, M.O.; Hospodková, Alice; Pangrác, Jiří; Zíková, Markéta; Hulicius, Eduard

    2016-01-01

    Roč. 10, č. 4 (2016), 1-8, č. článku 046013. ISSN 1934-2608 R&D Projects: GA ČR GA13-15286S; GA MŠk LO1603 Institutional support: RVO:68378271 Keywords : Shubnikov-de Haas oscillations * microwave absorption * electron-paramagnetic resonance * composite quantum wells * InAs/GaSb/AlSb * MOVPE Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.325, year: 2016

  18. Microwave antenna holography

    Science.gov (United States)

    Rochblatt, David J.; Seidel, Boris L.

    1992-01-01

    This microwave holography technique utilizes the Fourier transform relation between the complex far field radiation pattern of an antenna and the complex aperture field distribution. Resulting aperture phase and amplitude distribution data can be used to precisely characterize various crucial performance parameters, including panel alignment, panel shaping, subreflector position, antenna aperture illumination, directivity at various frequencies, and gravity deformation effects. The methodology of data processing presented here was successfully applied to the Deep Space Network (DSN) 34-m beam waveguide antennas. The antenna performance was improved at all operating frequencies by reducing the main reflector mechanical surface rms error to 0.43 mm. At Ka-band (32 GHz), the estimated improvement is 4.1 dB, resulting in an aperture efficiency of 52 percent. The performance improvement was verified by efficiency measurements and additional holographic measurements.

  19. Microwave heating type evaporator

    International Nuclear Information System (INIS)

    Taura, Masazumi; Nishi, Akio; Morimoto, Takashi; Izumi, Jun; Tamura, Kazuo; Morooka, Akihiko.

    1987-01-01

    Purpose: To prevent evaporization stills against corrosion due to radioactive liquid wastes. Constitution: Microwaves are supplied from a microwave generator by way of a wave guide tube and through a microwave permeation window to the inside of an evaporatization still. A matching device is attached to the wave guide tube for transmitting the microwaves in order to match the impedance. When the microwaves are supplied to the inside of the evaporization still, radioactive liquid wastes supplied from a liquid feed port by way of a spray tower to the inside of the evaporization still is heated and evaporated by the induction heating of the microwaves. (Seki, T.)

  20. Light-Emitting Pickles

    Science.gov (United States)

    Vollmer, M.; Mollmann, K-P.

    2015-01-01

    We present experiments giving new insights into the classical light-emitting pickle experiment. In particular, measurements of the spectra and temperatures, as well as high-speed recordings, reveal that light emission is connected to the polarity of the electrodes and the presence of hydrogen.

  1. Microwave sintering of ceramic materials

    Science.gov (United States)

    Karayannis, V. G.

    2016-11-01

    In the present study, the potential of microwave irradiation as an innovative energy- efficient alternative to conventional heating technologies in ceramic manufacturing is reviewed, addressing the advantages/disadvantages, while also commenting on future applications of possible commercial interest. Ceramic materials have been extensively studied and used due to several advantages they exhibit. Sintering ceramics using microwave radiation, a novel technology widely employed in various fields, can be an efficient, economic and environmentally-friendlier approach, to improve the consolidation efficiency and reduce the processing cycle-time, in order to attain substantial energy and cost savings. Microwave sintering provides efficient internal heating, as energy is supplied directly and penetrates the material. Since energy transfer occurs at a molecular level, heat is generated throughout the material, thus avoiding significant temperature gradients between the surface and the interior, which are frequently encountered at high heating rates upon conventional sintering. Thus, rapid, volumetric and uniform heating of various raw materials and secondary resources for ceramic production is possible, with limited grain coarsening, leading to accelerated densification, and uniform and fine-grained microstructures, with enhanced mechanical performance. This is particularly important for manufacturing large-size ceramic products of quality, and also for specialty ceramic materials such as bioceramics and electroceramics. Critical parameters for the process optimization, including the electromagnetic field distribution, microwave-material interaction, heat transfer mechanisms and material transformations, should be taken into consideration.

  2. Microwave-Based Water Decontamination System

    Science.gov (United States)

    Arndt, G. Dickey (Inventor); Byerly, Diane (Inventor); Sognier, Marguerite (Inventor); Dusl, John (Inventor)

    2016-01-01

    A system for decontaminating a medium. The system can include a medium having one or more contaminants disposed therein. The contaminants can be or include bacteria, fungi, parasites, viruses, and combinations thereof. A microwave energy radiation device can be positioned proximate the medium. The microwave energy radiation device can be adapted to generate a signal having a frequency from about 10 GHz to about 100 GHz. The signal can be adapted to kill one or more of the contaminants disposed within the medium while increasing a temperature of the medium by less than about 10 C.

  3. Chemical Modifications of Starch: Microwave Effect

    Directory of Open Access Journals (Sweden)

    Kamila Lewicka

    2015-01-01

    Full Text Available This paper presents basic methods of starch chemical modification, the effect of microwave radiation on the modification process, and the physicochemical properties of starch. It has been shown that the modifications contribute to improvement of the material performance and likewise to significant improvement of its mechanical properties. As a result, more and more extensive use of starch is possible in various industries. In addition, methods of oxidized starch and starch esters preparation are discussed. Properties of microwave radiation and its impact on starch (with particular regard to modifications described in literature are characterized.

  4. Quantum dynamics of crystals of molecular magnets inside microwave resonators

    Energy Technology Data Exchange (ETDEWEB)

    Amigo, R.; Tejada, J.; Chudnovsky, E.M.; Hernandez, J.M.; Garcia-Santiago, A. E-mail: antonio@ubxlab.comtoni@ubxlab.com

    2004-05-01

    It is shown that crystals of molecular nanomagnets exhibit enhanced magnetic relaxation when placed inside a resonant cavity. Strong dependence of the magnetization curve on the geometry of the cavity has been observed, providing evidence of the coherent microwave radiation by the crystals. These observations open the possibility of building a nanomagnetic microwave laser pumped by the magnetic field.

  5. Quantum dynamics of crystals of molecular magnets inside microwave resonators

    International Nuclear Information System (INIS)

    Amigo, R.; Tejada, J.; Chudnovsky, E.M.; Hernandez, J.M.; Garcia-Santiago, A.

    2004-01-01

    It is shown that crystals of molecular nanomagnets exhibit enhanced magnetic relaxation when placed inside a resonant cavity. Strong dependence of the magnetization curve on the geometry of the cavity has been observed, providing evidence of the coherent microwave radiation by the crystals. These observations open the possibility of building a nanomagnetic microwave laser pumped by the magnetic field

  6. Microwave-assisted extraction kinetics of terpenes from caraway seeds

    NARCIS (Netherlands)

    Chemat, S.; Ait-Amar, H.; Lagha, A.; Esveld, D.C.

    2005-01-01

    The process conditions during the extraction of carvone and limonene from caraway seed (Carum carvi L.) with microwave-assisted extraction have been studied with respect to microwave power, radiation dose and extraction time in order to obtain the secondary metabolites selectively. Using classical

  7. The microwave effects on the properties of alumina at high frequencies of microwave sintering

    Energy Technology Data Exchange (ETDEWEB)

    Sudiana, I. Nyoman, E-mail: sudiana75@yahoo.com; Ngkoimani, La Ode; Usman, Ida [Department of Physics, Faculty of Mathematic and Natural Science, Halu Oleo University, Kampus Bumi Tridharma Anduonohu, Kendari 93232 (Indonesia); Mitsudo, Seitaro; Sako, Katsuhide; Inagaki, Shunsuke [Research Center for Development of Far-Infrared Region, University of Fukui, 3-9-1 Bunkyo, Fukui-shi 910-8507 (Japan); Aripin, H. [Center for Material Processing and Renewable Energy, Faculty of Learning Teacher and Education Science, Siliwangi University, Jl. Siliwangi 24 Tasikmalaya 46115, West Java (Indonesia)

    2016-03-11

    Microwave sintering of materials has attracted much research interest because of its significant advantages (e.g. reduced sintering temperatures and soaking times) over the conventional heating. Most researchers compared processes that occurred during the microwave and conventional heating at the same temperature and time. The enhancements found in the former method are indicated as a 'non-thermal effect' which is usually used for explaining the phenomena in microwave processing. Numerous recent studies have been focused on the effect to elucidate the microwave interaction mechanism with materials. Moreover, recent progress on microwave sources such as gyrotrons has opened the possibility for processing materials by using a higher microwave frequency. Therefore, the technology is expected to exhibit a stronger non-thermal effect. This paper presents results from a series of experiments to study the non-thermal effect on microwave sintered alumina. Sintering by using a wide rage of microwave frequencies up to 300 GHz as well as a conventional furnace was carried out. The linear shrinkages of samples for each sintering method were measured. Pores and grains taken from scanning electron microstructure (SEM) images of cut surfaces were also examined. The results of a comparative study of the shrinkages and microstructure evolutions of the sintered samples under annealing in microwave heating systems and in an electric furnace were analyzed. A notably different behavior of the shrinkages and microstructures of alumina after being annealed was found. The results suggested that microwave radiations provided an additional force for mass transports. The results also indicated that the sintering process depended on microwave frequencies.

  8. The microwave effects on the properties of alumina at high frequencies of microwave sintering

    International Nuclear Information System (INIS)

    Sudiana, I. Nyoman; Ngkoimani, La Ode; Usman, Ida; Mitsudo, Seitaro; Sako, Katsuhide; Inagaki, Shunsuke; Aripin, H.

    2016-01-01

    Microwave sintering of materials has attracted much research interest because of its significant advantages (e.g. reduced sintering temperatures and soaking times) over the conventional heating. Most researchers compared processes that occurred during the microwave and conventional heating at the same temperature and time. The enhancements found in the former method are indicated as a 'non-thermal effect' which is usually used for explaining the phenomena in microwave processing. Numerous recent studies have been focused on the effect to elucidate the microwave interaction mechanism with materials. Moreover, recent progress on microwave sources such as gyrotrons has opened the possibility for processing materials by using a higher microwave frequency. Therefore, the technology is expected to exhibit a stronger non-thermal effect. This paper presents results from a series of experiments to study the non-thermal effect on microwave sintered alumina. Sintering by using a wide rage of microwave frequencies up to 300 GHz as well as a conventional furnace was carried out. The linear shrinkages of samples for each sintering method were measured. Pores and grains taken from scanning electron microstructure (SEM) images of cut surfaces were also examined. The results of a comparative study of the shrinkages and microstructure evolutions of the sintered samples under annealing in microwave heating systems and in an electric furnace were analyzed. A notably different behavior of the shrinkages and microstructures of alumina after being annealed was found. The results suggested that microwave radiations provided an additional force for mass transports. The results also indicated that the sintering process depended on microwave frequencies.

  9. Microwave energy transmission

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Hiroshi [Kyoto Univ. (Japan)

    1989-03-05

    Laying stress on the technological problems and effect on the environment of microwave energy transmission, recent scientific and engineering problems and related subjects are described. Because no fuel is required for the solar power generation, the power generation system can not be considered as an expensive one when the unit cost of energy is taken into consideration. Some of the important technological problems in the microwave energy transmission are accurate microwave beam control technology to receiving stations and improvement in the efficiency of transmission system. Microwave energy beam has effects on living bodies, communication, and plasma atmosphere of the earth. Microwave energy transmission using a space flyer unit is scheduled. Its objective is the development of microwave wireless transmission technology and the study of the correlation between high power microwave and ionosphere plasma. Experiments on such a small scale application as a microwave driven space ship to bring results seem also important. 12 refs., 13 figs.

  10. Safety of light emitting diodes in toys.

    Science.gov (United States)

    Higlett, M P; O'Hagan, J B; Khazova, M

    2012-03-01

    Light emitting diodes (LEDs) are increasingly being used in toys. An assessment methodology is described for determining the accessible emission limits for the optical radiation from the toys, which takes account of expected use and reasonably foreseeable misuse of toys. Where data are available, it may be possible to assess the toy from the data sheet alone. If this information is not available, a simple measurement protocol is proposed.

  11. Safety of light emitting diodes in toys

    International Nuclear Information System (INIS)

    Higlett, M P; O'Hagan, J B; Khazova, M

    2012-01-01

    Light emitting diodes (LEDs) are increasingly being used in toys. An assessment methodology is described for determining the accessible emission limits for the optical radiation from the toys, which takes account of expected use and reasonably foreseeable misuse of toys. Where data are available, it may be possible to assess the toy from the data sheet alone. If this information is not available, a simple measurement protocol is proposed.

  12. Advances in microwaves 7

    CERN Document Server

    Young, Leo

    2013-01-01

    Advances in Microwaves, Volume 7 covers the developments in the study of microwaves. The book discusses the effect of surface roughness on the propagation of the TEM mode, as well as the voltage breakdown of microwave antennas. The text also describes the theory and design considerations of single slotted-waveguide linear arrays and the techniques and theories that led to the achievement of wide bandwidths and ultralow noise temperatures for communication applications. The book will prove invaluable to microwave engineers.

  13. Microwave processing heats up

    Science.gov (United States)

    Microwaves are a common appliance in many households. In the United States microwave heating is the third most popular domestic heating method food foods. Microwave heating is also a commercial food processing technology that has been applied for cooking, drying, and tempering foods. It's use in ...

  14. Decomposition of Askarel Oil by Microwave Radiation and H202/TiO2 Agents in Order to Reduce Occupational Hazards

    Directory of Open Access Journals (Sweden)

    Reza Tajik

    2012-06-01

    Full Text Available Background: Poly chlorinated biphenyls (PCBS are the groups of organicchemical material and toxic, persistent, bio accumulate and pose a risk of causingadverse effects to human health and the environment. PCB compounds arecaused the different health effects in human depending of age, sex, route of entry,intensity and frequency exposure. This study was conducted to determine theeffect of microwave rays, hydrogen peroxide, TiO2 catalyst and ethanol on theDecomposition of PCBS.Methods: In this experiment used a MW oven, Pyrex vessel reactor (250mlvolume, Pyrex tube connector and condensing system. A 900w domestic MWoven with a fixed frequency of 2450 MHZ was used to provide MW irradiation. Raypowers used in 540، 720 and 900w. The PCBS were analyzed by GC-ECDResults: The degradation of total PCBS in terms of 540, 720 and 900W was85.03%, 90.32% and 96.87% respectively. The degradation of total PCBS in termsof ratio to solvent with transformer oil in 1:1، 2:1 and 3:1 was 53.97%، 78.98% and95.13% respectively. The degradation of total PCBs in terms of not using of H2O2/TiO2 and using 20% of H2O2 and 0.05, 0.1, 0.15 and 0.2 g TiO2 was 68.78%,93.97%, 95.13%, 96.18% and 96.87 % respectively.Conclusion: The Microwave thermal reaction was applied for the dechlorinationof PCBs and high efficiencies were obtained. Microwave power and amounts ofreactants added are important factors influencing dechlorination efficiency.

  15. Public Health Ministere stablish that all medical equipment records request who emit ionizing radiations providing health organizations, Public or privates, such as enterprise who trade medical products, have to be carry out between of the Public a Health Ministere Technology Department and DINATEN of the Industry energy and Mining Ministere

    International Nuclear Information System (INIS)

    2004-01-01

    The present decree stablish that the evaluation of all the applications of registration of medical teams that emit ionizing radiations, coming from the institutions of health, you publish or private, as well as companies that market medical products will be carried out among the Department of Technology it Prescribes of the Ministry of Health it Public and the DINATEN of the Ministry of Industry Energy and Mining

  16. Top-emitting organic light-emitting diodes.

    Science.gov (United States)

    Hofmann, Simone; Thomschke, Michael; Lüssem, Björn; Leo, Karl

    2011-11-07

    We review top-emitting organic light-emitting diodes (OLEDs), which are beneficial for lighting and display applications, where non-transparent substrates are used. The optical effects of the microcavity structure as well as the loss mechanisms are discussed. Outcoupling techniques and the work on white top-emitting OLEDs are summarized. We discuss the power dissipation spectra for a monochrome and a white top-emitting OLED and give quantitative reports on the loss channels. Furthermore, the development of inverted top-emitting OLEDs is described.

  17. Examples of Radiation-Emitting Products

    Science.gov (United States)

    ... Ultrasonography • Doppler ultrasound • Color doppler ultrasound • Hyperthermia • Diathermy/physical therapy • Bone healing • Lithotripsy • Phacoemulsifier • Needle guide • Bone density measuring • Geriatric bath (ultrasound) • Hearing aid • Many scientific uses • Nondestructive ...

  18. Ab initio investigation of barium-scandium-oxygen coatings on tungsten for electron emitting cathodes

    Science.gov (United States)

    Vlahos, Vasilios; Booske, John H.; Morgan, Dane

    2010-02-01

    Microwave, x-ray, and radio-frequency radiation sources require a cathode emitting electrons into vacuum. Thermionic B-type dispenser cathodes consist of BaxOz coatings on tungsten (W), where the surface coatings lower the W work function and enhance electron emission. The new and promising class of scandate cathodes modifies the B-type surface through inclusion of Sc, and their superior emissive properties are also believed to stem from the formation of a low work function surface alloy. In order to better understand these cathode systems, density-functional theory (DFT)-based ab initio modeling is used to explore the stability and work function of BaxScyOz on W(001) monolayer-type surface structures. It is demonstrated how surface depolarization effects can be calculated easily using ab initio calculations and fitted to an analytic depolarization equation. This approach enables the rapid extraction of the complete depolarization curve (work function versus coverage relation) from relatively few DFT calculations, useful for understanding and characterizing the emitting properties of novel cathode materials. It is generally believed that the B-type cathode has some concentration of Ba-O dimers on the W surface, although their structure is not known. Calculations suggest that tilted Ba-O dimers are the stable dimer surface configuration and can explain the observed work function reduction corresponding to various dimer coverages. Tilted Ba-O dimers represent a new surface coating structure not previously proposed for the activated B-type cathode. The thermodynamically stable phase of Ba and O on the W surface was identified to be the Ba0.25O configuration, possessing a significantly lower Φ value than any of the Ba-O dimer configurations investigated. The identification of a more stable Ba0.25O phase implies that if Ba-O dimers cover the surface of emitting B-type cathodes, then a nonequilibrium steady state must dominate the emitting surface. The identification of

  19. Radiation and the New Zealand community : a scientific overview

    International Nuclear Information System (INIS)

    1998-01-01

    This book is intended to give information and perspective on the risks associated with the widespread use of radiations of different types in modern society. Chapter 1 introduces the radiations that are discussed. It raises questions, which the book seeks to answer about risks and benefits of radiation applications, and discusses the meaning of the oft-quoted expression n uclear free . Chapter 2 briefly describes the nature of radioactivity and the types of radioactive decay processes and emitted radiations most commonly observed. Chapter 3 traces from the perspective of historical developments the use of x-rays and radioactive materials in medical practice. Chapter 4 outlines the wide range of applications of radioactive materials in x-ray equipment in industry with particular emphasis on applications in New Zealand. Chapter 5 is devoted to a description of food irradiation. Chapter 6 is devoted to non-ionizing radiation applications, with separate sections on ultraviolet radiation, visible radiation, lasers, infrared radiation, microwave and radiofrequency radiation ,with some particular reference to cellular phone systems, extremely low frequency electric and magnetic fields and ultrasound. Chapter 7 concludes with an outline of the system of controls on ionizing radiation sources in New Zealand. (author). 7 appendices

  20. Proceedings of microwave processing of materials 3

    International Nuclear Information System (INIS)

    Beatty, R.L.

    1992-01-01

    This book contains proceedings of the third MRS Symposium on Microwave Processing of Materials. Topics covered include: Microwave Processing Overviews, Numerical Modeling Techniques, Microwave Processing System Design, Microwave/Plasma Processing, Microwave/Materials Interactions, Microwave Processing of Ceramics, Microwave Processing of Polymers, Microwave Processing of Hazardous Wastes, Microwave NDE Techniques and Dielectric Properties and Measurements