Three classes of solar emanations, namely, photon radiation from solar flares, solar energetic particles, and inhomogeneities in the solar wind that drive magnetic storms, are examined, and their effects on humans and technological systems are discussed. Solar flares may disrupt radio communications in the HF and VLF ranges. Energetic particles pose a special hazard at low-earth orbit and above, where they can penetrate barriers such as spacesuits and aluminum and destroy cells and solid state electronics. Energetic solar particles also influence terrestrial radiowaves propagating through polar regions. Magnetic storms may disturb the operation of navigation instruments, power lines and pipelines, and satellites; they give rise to ionospheric storms which affect radio communication at all latitudes. There is also a growing body of evidence that changes in the geomagnetic field ...
This book presents the current knowledge about the effects of electromagnetic fields on living matter. The three-part format covers dielectric permittivity and electrical conductivity of biological materials; effects of direct current and low frequency fields; and effects of radio frequency (including microwave) fields. The parts are designed to be consulted independently or in sequence, depending upon the needs of the reader. Useful appendixes on measurement units and safety standards are also included.
The operation and proper handling of equipment for measuring EMR-300 electromagnetic waves are studied and apply that knowledge to determine which areas of the metropolitan area are mostly affected by exposure to the emission of radiation. This team is able to measure magnetic field strength, electric field strength and power density, also can measure the most important parameters in a simple manner. International standards provide maximum values for these parameters that limit human exposure to such radiation. These standards are based on epidemiological several and laboratory that have been carried out in order to determine in which circumstances a biological entity is exposed to a level of radiation that can cause harm to their health. It focuses on measuring the level of radiation in certain areas of interest, which were chosen because are areas with high population density and also in proximity to antennas that emit electromagnetic ...
An extension of the Hodgkin-Huxley mathematical model for the propagation of nerve signal which takes into account dynamical heat transfer in biological tissue is derived and fine tuned with existing experimental data. The medium is heated by Joule's effect associated with action potential propagation, leading to characteristic thermal patterns in association with spiral and scroll waves. The introduction of heat transfer-necessary on physical grounds-provides a novel way to directly observe the movement, regular or chaotic, of the tip of spiral waves in numerical simulations and possibly in experiments regarding different biological excitable media.
Josephson effect heterodyne mixers with external local oscillators are very promising low noise mm-wave receivers for applications such as radio astronomy. Experiments at 36 GHz have shown that both the noise and the conversion efficiency of mixers made using Nb point contacts are in quantitative agreement with values calculated from the resistively shunted junction (RSJ) model. Preliminary measurements at 140 GHz suggest that this agreement extends to higher frequencies. In this paper the theoretical limits to the sensitivity of such receivers are explored as a function of the signal frequency. (Auth.).
The possibility of radio galaxies being random sample of otherwise normal elliptical galaxies is tested. Starting with the observed optical luminosity functions for elliptical galaxies, it is shown that the probability of an elliptical forming a radio source is a continuous, increasing function of optical luminosity, precisely proportional to square of the optical luminosity of the galaxy. Once the probability function is fixed, the luminosity function of normal elliptical galaxies is used as input for Monte Carlo simulations that reproduce the distribution of radio galaxies in the radio-optical luminosity plane. Our results show that radio galaxies are luminosity biased, but otherwise random sample of elliptical galaxies. This unified view of radio and non-radio ellipticals also explains the well known difference of 0.5 mag in average ...
To identify radio-protective agent candidate among medicinal plants and to elucidate the mechanism of action of the candidate material by using modern biochemical and molecular biological methods, we screened radio-protective activity among 48 medicinal plants. Seven samples showed above 20% protective activities against oxidative cell damage: Euryale ferox, Glycyrrhiza uralensis, Salvia miltiorrhiza, Eucomia ulmoides, Paeonia suffruticosa, Spirodela polyrrhiza, and Nelumbo nucifera. We also screened for oxidative stress sensitizing activity among other 51 medicinal plants. Among those samples, 11 samples showed good sensitizing effect; Melia azedarach, Agastache rugosa, Catalpa ovata, Prunus persica, Sinomenium acutum, Pulsatilla koreana, Oldenlandia diffusa, Anthriscus sylvestris, Schizandra chinensis, Gleditsia sinensis, and Cridium officinale. We also reported the ...
... Microwaves, radiowaves, and low-frequency electromagnetic fields from high-voltage transmission lines . Non-Methane Hydrocarbon (NMHC): The sum of all hydrocarbon air ...
A method for conditioning electron beams is proposed, making use of the TM{sub 210} mode of microwave cavities, to reduce the axial velocity spread within the beam, in order to enhance gain in resonant electron beam devices, such as the free-electron laser (FEL). Effectively, a conditioner removes the restriction on beam emittance. The conditioner is analyzed using a simple model for beam transport and ideal RF cavities. Analysis of an FEL is employed to evaluate performance with reduced axial velocity spread. Examples of FELs are presented showing the distinct advantage of conditioning.
The wavelength of the free electron laser (FEL) in Osaka University can be continuously varied in the range of 5.0-20.0 #mu#m. The FEL has a double-pulse structure, consisting of a train of macropulses of pulse duration 12 #mu#s. Each macropulse contains a train of 330 micropulses of pulse duration 5 ps. The tunability and picosecond pulses afford new medical and biological applications. However, a macropulse of long pulse duration leads to undesirable secondary effects. Precise control of the macropulse duration is essential for the high-precision applications of the FEL. An FEL pulse control system using acousto-optic modulators has been developed to investigate mechanical (shock-wave) effects of the FEL on living tissues. With this system, we have controlled photoinduced shock waves and determine the mechanism of interaction during FEL-induced tissue ablation.
We discuss optimal detection of fast radio transients from astrophysical objects while taking into account the effects of propagation through intervening ionized media, including dispersion, scattering and scintillation.Our analysis applies to the giant-pulse phenomenon exhibited by some pulsars, for which we show examples, and to radio pulses from other astrophysical sources, such as prompt radio emission from gamma-ray burst sources and modulated signals from extra-terrestrial civilizations.
Understanding risks from exposures to carcinogens and other chemicals depends upon measurement of their dose to target tissues and their reactivity with critical macromolecules. The authors have used AMS detection of radio-isotopes to assess doses and reactivities at low, environmentally relevant doses. Several biomedical investigations show the effectiveness of quantification of biologically important events at extremely high sensitivity with AMS. Specifically, they have measured the addition of environmental carcinogens such as 2-amino-3,8-dimethylimidazo[4,5-f]-quinoaxaline (MelQx), a chemical found in cooked food, to DNA at concentrations relevant to human exposure. Other low level detection problems in biology, such as immunoassay assessment of small environmental chemicals, is being developed with attomole sensitivity. AMS also aids the assessment of genotoxic risks from chemicals by quantifying ...
We test the hypothesis that radio galaxies are a random subset of otherwise normal elliptical galaxies. Starting with the observed optical luminosity functions for elliptical galaxies, we show that the probability of an elliptical forming a radio source is a continuous, increasing function of optical luminosity, proportional to L squared. With this probability function and the luminosity function of normal elliptical galaxies as input to Monte Carlo simulations, we reproduce the observed distribution of radio galaxies in the radio-optical luminosity plane. Our results show that radio galaxies are a luminosity-biased but otherwise random sample of elliptical galaxies. This unified view of radio-loud and radio-quiet ellipticals also explains the well known difference of ~0.5 mag in average optical luminosity between FRI and FRII ...
This book gives an overview of the entire field of radiation protection with the subject areas radioactivity, X-rays, UV radiation, laser beams and high-frequency electromagnetic fields. It deals graphically with the most important physical notions, the incidence, origin, properties and biologicaleffects of types of radiation, administrative and practical protection measures and the code of rules governing them. Apart from fundamentals of radiation protection the emphasis on the following: natural radiation exposure, radiation exposure to radon, disaster relief plans in the environment of nuclear plant, the precautionary radiation protection system evolved after Chernobyl, radiation exposure through UV radiation devices, radio, RF communication, radar, microwave ovens and high-voltage transmission lines as well as computer work-places. (orig.).
...Explore - The Lab - Australian Broadcasting Corporation's Gateway to Science Radio TV Shop News Sport Local Children Science Environment more Topics help Science Home News in Science Features Explore TV & Radio Dr Karl Play Podcasts DNA - The discovery of the double helix structure of DNA completely changed biology and opened up the new field of genetics. The 'backbone of life' has given us the human genome, stem cell research, ...
Effects of 2450-MHz circularly polarized microwave irradiation on central nervous system functions were studied. Pulsed (microsecond, 500 pps) microwaves decreased high-affinity sodium-dependent choline uptake in the hippocampus and frontal cortex of the rat. The effect on hippocampal choline uptake was blocked by pretreatment with narcotic antagonists. Continuous-wave microwaves of the same power density decreased choline uptake in the frontal cortex only. Furthermore, it was found that the effects of pulsed microwaves on central cholinergic activity are classically conditionable to cues in the exposure environment. The hypothesis that some of the neurological effects of pulsed microwave irradiation are caused by its effect on the auditory system was investigated. Effects of pink noise and pulsed microwaves were compared.
We consider light waves propagating clockwise and other light waves propagating counterclockwise around a closed path in a plane (theoretically with the help of stationary mirrors). The time difference between the two light propagating path orientations constitutes the Sagnac effect. The general relativistic expression for the Sagnac effect is discussed. It is shown that a gravitational wave incident to the light beams at an arbitrary angle will not induce a Sagnac effect so long as the wave length of the weak gravitational wave is long on the length scale of the closed light beam paths. The gravitational wave induced Sagnac effect is thereby null.
Sodium-dependent high-affinity choline uptake was measured in the striatum, frontal cortex, hippocampus, and hypothalamus of rats after acute exposure (45 min) to pulsed (2 microseconds, 500 pps) or continuous-wave 2,450-MHz microwaves in cylindrical waveguides or miniature anechoic chambers. In all exposure conditions, the average whole-body specific absorption rate was at 0.6 W/kg. Decrease in choline uptake was observed in the frontal cortex after microwave exposure in all of the above irradiation conditions. Regardless of the exposure system used, hippocampal choline uptake was decreased after exposure to pulsed but not continuous-wave microwaves. Striatal choline uptake was decreased after exposure to either pulsed or continuous-wave microwaves in the miniature anechoic chamber. No significant change in hypothalamic choline uptake was observed under any of the exposure conditions studied. We conclude that depending on ...
Increase in power utility loads in industrialized countries, as well as developing countries, demands a higher level of transmission line voltage. Radio interference (RI) problems have been determined to be a limiting factor in selecting the size of transmission line conductors. Transmission line noise is primarily caused by corona discharges in the immediate vicinity of the conductor. It has been observed that discharges occur during both half-cycles of the applied voltage, but positive corona is usually predominant at AM radio frequencies range with practical high-voltage and extra high-voltage transmission lines. The corona radio noise effect is highly dependent upon the presence of particles on the surface of the conductor and the increase of the electrical gradient beyond the breakdown value of the air. Therefore, corona radio noise varies significantly with the weather and ...
Increase in power utility loads in industrialized countries, as well as developing countries, demands a higher level of transmission line voltage. Radio interference (RI) problems have been determined to be a limiting factor in selecting the size of transmission line conductors. Transmission line noise is primarily caused by corona discharges in the immediate vicinity of the conductor. It has been observed that discharges occur during both half-cycles of the applied voltage, but positive corona is usually predominant at AM radio frequencies range with practical high-voltage and extra high-voltage transmission lines. The corona radio noise effect is highly dependent upon the presence of particles on the surface of the conductor and the increase of the electrical gradient beyond the breakdown value of the air. Therefore, corona radio noise varies significantly with the weather and ...
Increase in power utility loads in industrialized countries, as well as developing countries, demands a higher level of transmission line voltage. Radio interference (RI) problems have been determined to be a limiting factor in selecting the size of transmission line conductors. Transmission line noise is primarily caused by corona discharges in the immediate vicinity of the conductor. It has been observed that discharges occur during both half-cycles of the applied voltage, but positive corona is usually predominant at AM radio frequencies range with practical high-voltage and extra high-voltage transmission lines. The corona radio noise effect is highly dependent upon the presence of particles on the surface of the conductor and the increase of the electrical gradient beyond the breakdown value of the air. Therefore, corona radio noise varies significantly with the weather and ...
The electromagnetic properties of a prototype gravitational wave detector, based on two coupled superconducting microwave cavities, were tested. The radio-frequency (rf) detection system was carefully analysed. With the use of piezoelectric crystals small harmonic displacements of the cavity walls were induced and the parametric conversion of the electromagnetic field inside the cavities explored. Experimental results of bandwidth and sensitivity of the parametric converter versus stored energy and voltage applied to the piezoelectric crystal are reported. A rf control loop, developed to stabilize phase changes on signal paths, gave a 125 dBc rejection of the drive mode on a time scale of 1 h.
Advances made in understanding the chemistry and dynamics of the atmosphere in the approximate altitude range of 50 to 90 km are addressed. Attention is given to mesospheric structure and seasonal variations, gravity waves and gravity wave saturation, the effects of gravity waves on thermal, momentum and constituent fluxes, and the effect of gravity waves on airglow emissions. A review of research on tides and planetary waves and their effects on the mesosphere are presented as well as discussions on ozone hydroxyl, water vapor, and noctilucent cloud research. 217 refs.
Electromagnetic fields have been reported to cause a variety of biologicaleffects. It has been hypothesized that many of these phenomena are mediated by a primary effect on the concentration of cytosolic free calcium ((Ca2+)i). We investigated the effects of exposure to electromagnetic fields on (Ca2+)i in HL-60 cells using the Ca2(+)-sensitive fluorescent indicator indo-1. Indo-1-loaded cell samples were exposed to a radiofrequency electromagnetic field, a static magnetic field, and a time-varying magnetic field, which were generated by a magnetic resonance imaging (MRI) unit. We found that a 23-min exposure to all three fields, in combination, induced a significant increase in (Ca2+)i of 31 +/- 8 (SE) nM (P less than 0.01, n = 13) from a basal level of 121 +/- 8 nM. Also, cells exposed to only the time-varying magnetic field had a mean (Ca2+)i that was 34 +/- 10 nM (P less than 0.01, n = 11) higher ...
In recent years, there has been a significant increase in concern over the health and safety aspects of high voltage transmission lines (HVTL). The majority of research has focused on effects directly or indirectly involved with the central nervous system, including physiological, ultrastructural, and biochemical alterations, changes in blood composition, behaviour, reproduction, and development. Several recent epidemiological reports have presented preliminary data suggesting an increase in the incidence of cancer among children and adults exposed to magnetic fields through living close to various types of electrical power lines or devices. With the increase in environmental concerns there has been a concomitant consideration of biologicaleffects and health implications related to presently existing HVTL and those planned in the future. It was concluded that the electric and magnetic field strengths and the electrical ...
Little clinical evidence has been provided to show the minimization of radiation resistance of tumors using high linear energy transfer radiation. We therefore investigated the radiobiological and molecular pathological aspects of carbon beam therapy. A total of 27 patients with squamous cell carcinoma (SCC) of the cervix were treated using a carbon beam and 50 control patients with SCC of the cervix using a photon beam. The expression of Ki-67, p53, and p27 proteins before radiotherapy and 5 and 15 days after therapy initiation were investigated using immunohistochemistry. Similar changes were observed in Ki-67 labeling index (LI) and p53 LI during carbon and photon beam therapies. However, for carbon beam therapy, the mean p27 LI significantly decreased from 25.2% before treatment to 18.6% on the 5th day after treatment initiation, followed by a significant increase to 36.1% on the 15th day. In contrast, for photon beam therapy, the p27 LI consistently decreased from the initial ...
Optimal neutron energy for boron neutron capture therapy (BNCT) has been studied. Epithermal neutron is superior to thermal neutrons in treating deep-seated tumors. Design of the epithermal neutron column for BNCT has been performed by using a two-dimensional transport calculation code. Aluminum and heavy water are used as moderation materials. A thermal neutron column is also designed using heavy water as thermalization material. The configuration of the facility for treatment and research of BNCT and also for basic radio-biological studies of neutrons has been presented.
Optimal neutron energy for boron neutron capture therapy (BNCT) has been studied. Epithermal neutron is superior to thermal neutrons in treating deep-seated tumors. Design of the epithermal neutron column for BNCT has been performed by using a two-dimensional transport calculation code. Aluminum and heavy water are used as moderation materials. A thermal neutron column is also designed using heavy water as thermalization material. The configuration of the facility for treatment and research of BNCT and also for basic radio-biological studies of neutrons has been presented. (author).
Daily exposures of adult beagle dogs to inhaled radon daughters and to uranium ore dust for 4-1/2 to 6 yr have produced respiratory tract carcinomas, at similar cumulative working level months (WLM) of exposures to those which induced carcinomas in uranium miners. Biological data from the beagle-dog experiments can therefore be used for prediction of carcinogenic risk under changing exposure conditions in future uranium miners.
Today, highly frequent radiowaves are regarded as undangerous to man. Diseases seen at radar-technicians during the 2nd World War, however, indicated that microwaves applied in radar systems were hazardous to health. The Russian work medicine has been knowing microwave-caused hazards in industry since the beginning of the thirties. Therefore in some East-European countries there are terms of protection and severe norms of safety for the staying of persons in the radiation sphere of microwaves.
The study of the scrape-off layer (SOL) during Alfven wave heating may lead to a better understanding of the antenna-plasma interaction. The scrape-off layer of the TCA tokamak has been widely investigated by means of Langmuir probes. The aim of this work is to present measurements on the influence of the Alfven wave spectrum on the scrape-off layer. These experiments have shown that the plasma boundary layer is strongly affected by the wave field, in particular the ion saturation current and the floating potential. In TCA, as the spectrum evolves due to a density rise, the passage of the Alfven continua and their associated eigenmodes, the Discrete Alfven Wave (DAW) induces a strong depletion in the edge density of up to 70% during the continuum part and a density increase during the crossing of an eigenmode. The floating potential becomes negative during the continua and even more negative crossing ...
The radio, optical, x-ray and gamma-ray nebulae that surround many pulsars are thought to arise from synchrotron and inverse Compton emission. The energy powering this emission as well as the magnetic fields and relativistic particles are supplied by a 'wind' driven by the central object. The inner parts of the wind can be described using the equations of MHD, but these break down in the outer parts, when the density of charge carriers drops below a critical value. This paper reviews the wave properties of the inner part (striped wind), and uses a relativistic two-fluid model (cold electrons and positrons) to re-examine the nonlinear electromagnetic modes that propagate in the outer parts. It is shown that in a radial wind, two solutions exist for circularly polarized electromagnetic modes. At large distances one of them turns into a freely expanding flow containing a vacuum wave, whereas the other decelerates, ...
The dielectrical properties of organosilicon sealants have been studied in the wide range of temperatures in the low and radio frequencies range. The effect of thermal treatment and #gamma#-irradiation on these properties is discussed.
We reported the radio-protective effect of DTT. The treatment of DTT increased cell survival after gamma-irradiation, decreased in the frequencies of micronucleus, and reduction in DNA fragmentation and apoptotic cells. Induction of apoptosis after UV-C irradiation was revealed by the changes in the relative cell death, increase in the relative amount of apoptotic cells, and the induction of DNA fragmentation. About 100 medicinal plants were purchased and methanol extract samples were prepared. Radio-protective and radio-sensitizing activities of these samples were screened. Seven samples showed above 20% radio-protective activities: Salvia miltiorrhiza, Areca catechu, Cornus officinalis, Alpiniae officinari rhizoma, Meliae fructus, Alpiniae katsumadaii semen, Betulae cortex. Acanthopanax sessiliflous showed the highest radio-sensitizing ...
Atomic L- and M-shell ionization cross sections by protons have been calculated in the plane-wave Born approximation for /sub 79/Au and /sub 92/U with incident energy from 0.1 to 3 MeV with use of relativistic and nonrelativistic Hartree-Slater wave functions. These results are compared with those from the screened hydrogenic model to study the effects of relativity and wave functions. The relativistic and wave-function effects are found to operate in opposite directions. For M/sub 1,2,3/-subshell cross sections, severe cancellations occur between these two factors.
The impact of the azimuthal wave refraction in the middle atmosphere on the distribution of gravity wave amplitudes, propagation azimuths, and other wave parameters is investigated using a numerical ray-tracing model of gravity wave propagation through a representative zonal mean reference model of geostrophic winds and temperature in the middle atmosphere. Simulations are first performed with only a single type of gravity wave to help explain some important effects which occur during the refraction process. Then, a multiray simulation is performed which traces a crude spectrum of waves from different altitudes through the atmosphere for every month of a climatological year. The simulated wave climatologies are compared with observations. 108 refs.
... biologicaleffects of electromagnetic fields (EMFs) produced by high-voltage transmission lines have come under intense scrutiny, mostly with respect ... biologicaleffects of electromagnetic fields (EMFs...
The effective population size (Ne) is an important parameter in ecology, evolutionary biology and conservation biology. It is, however, notoriously difficult to estimate,...Full Text Available
Electron spin resonance spectroscopy can provide a powerful approach to the study of radiation effects in biological materials. This memorandum gives an overview of current and future research. (author).
This study compared the effectiveness of collaborative group composition and instructional method on reasoning gains and achievement in college biology. Based on initial student reasoning ability (i.e.,...Full Text Available
The book examines current experimental and clinical knowledge concerning the biological and biophysical effects of electromagnetic radiation, particularly that in the microwave range. The biophysical bases of the interaction of electromagnetic radiation with matter are reviewed with emphasis on biological systems, and the effects of radiation on critical biological systems, including the nervous, reproductive, visual and blood-forming systems are compared. Data concerning the lethal effects of nonionizing radiation is presented and characteristics of the effects of electromagnetic radiation on the whole mammalian organisms are examined. Various reactions of the neuroendocrine system to electromagnetic radiation are described, with particular attention given to the adrenal system, and the combined effects of ionizing and ...
For many years, {beta} radioactivity has been used to label molecules and follow them in various biological processes. {beta} imaging is obtained by autoradiography. Classically made on films or on photographic emulsions, autoradiography is now supplanted by radio-imagers which are very performing. The phosphor-imager, {beta}-imager and {mu}-imager are the systems mainly used today and their operating principles and properties are compared. The great advantages of these imagers are: their rapidity to obtain results and their reliability for absolute quantification. All emitters ({beta}{sup -}, {beta}{sup -} -{gamma} and {beta}{sup +}) are detectable as well as the gamma emitters of nuclear medicine, by means of their low energy electrons ejected during y emission. Phosphor-imager is well suited to energetic tracers and large series of experiments. Real time radio-imagers ({beta}-imager and {mu}-imager) are preferred to ...
A first-order one-way wave system has been created based on characteristic analysis of the acoustic wave system and optimization of the dispersion relation. The authors demonstrate that this system is equivalent to a third-order scalar partial-differential equation which, for a homogeneous medium, reduces to a form similar to the 45{degree} paraxial wave equation. This system describes accurately waves propagating in a 2D heterogeneous medium at angles up to 75{degree}. The one-way wave system representing downgoing waves is used for a modified reverse time migration method. As a wavefield extrapolator in migration, the downgoing wave system propagates the reflection events backwards to their reflectors without scattering at the discontinuities in the velocity model. Hence, images with amplitudes proportional to reflectivity can be obtained ...
A recent study reported the results of an exploratory study of alterations of the quantitative sleep profile due to the effects of a digital mobile radio telephone. Rapid eye movement (REM) was suppressed, and the spectral power density in the 8--13 Hz frequency range during REM sleep was altered. The aim of the present study was to illuminate the influence of digital mobile radio telephone on the awake electroencephalogram (EEG) of healthy subjects. For this purpose, the authors investigated 34 male subjects in a single-blind cross-over design experiment by measuring spontaneous EEGs under closed-eyes condition from scalp positions C{sub 3} and C{sub 4} and comparing the effects of an active and an inactive digital mobile radio telephone (GSM) system. During exposure of nearly 3.5 min to the 900 MHz electromagnetic field pulsed at a frequency of 217 Hz and with a pulse width of 580 ...
The aim of our experiment was the testing of effects of common ammunition on usable and slightly accessible biological tissue thereby to create fundamental simple biological model for trials of wounded ballistic. Like objective tissue was elected biological material - pork and beef hind-limbs, pork head, pork bodily cavity. It was discovered that objective tissue is able to react to singles types of shots in all spectrum results namely simple smooth penetration wound as well as splintery fracture in dependence on kind of using ammunition. Pork hind-limb was evaluated like the most suitable biological material for given object. PMID:17172163
Initial design parameters and early operational results of a 50 MeV high brightness electron linear accelerator are described. The system utilizes a radio frequency electron gun operating at a frequency of 2.856 GHz and a nominal output energy of 4.5 MeV followed by two, 2#pi#/3 mode, disc loaded, traveling wave accelerating sections. The gun cathode is photo excited with short (6 psec) laser pulses giving design peak currents of a few hundred amperes. The system will be utilized to carry out infra-red FEL studies and investigation of new high gradient accelerating structures.
The historical back ground of free electron laser (FEL) and the present status of development and utilization research of FEL facilities in the world are explained. Eight facilities such as Stanford Univ., UCSB, Duke Univ., Vanderbilt Univ., LANL AFEL (USA), FOM FELIX (Netherlands), N-lands LURE CLIO (France) and FELI (Japan) can be used. The principle of FEL generation process is that free electrons move in a zigzag direction to generate radiowaves which interfere with each other to become monochromatic light and then free electron laser. The benefits of FEL, quality of electron beam, limit of wave length of FEL, problems and development of utilization technologies of FEL are explained. (S.Y.)
The purpose of this paper is to establish probabilistic models for still-water loads, based on design data, and the combined still-water and wave load effects for semi-probabilistic and probabilistic design of floating production, storage and offloading vessels (FPSO). A new still-water load model for FPSOs is proposed, based on a Poisson square-wave model, with a modified Weibull distribution for load intensity, which accounts for load control during operation. The long-term variation of wave-induced load effects is modelled by a Poisson square-wave process. A new solution for the combined effect is derived. A procedure for determining characteristic extreme values for individual and combined load effects, and load combination factors, is established. The methodology is used to illustrate...
A sample of 41 radio-galaxies with 13.0<=msub(corr)<=15.5 has been analyzed to test the angular redshift anisotropy discovered on Sc I galaxies by Rubin, Rubin and Ford (1973). The sample does not present their anisotropy but contains an even more curious distribution of radial velocities which suggests that the Rubin-Ford effect results from an anomalous redshift of light when it travels through clusters of galaxies. (Auth.).
AbstractThree biologic dressings [split-thickness allogeneic skin (STS)], allogeneic peritoneum (P), and xenogenic porcine small intestinal submucosa (PSIS)] were...Full Text Available
Discussions on a form of a frequency spectrum of wind-driven sea waves just above the spectral maximum continue during the last three decades. In 1958 Phillips made a conjecture that wave breaking is the main mechanism responsible for the spectrum formation. That leads to the spectrum decay $\\sim \\omega^{-5}$, where $\\omega$ is the frequency of the waves. There is a contradiction between the numerous experimental data and this spectrum. The experiments show decay $\\sim\\omega^{-4}$. There are two general ways of the explanation of this phenomenon. The first one (proposed by Banner (1990)) takes into account the Doppler effect due to surface circular currents generated by long waves in the Phillips model. The second approach ascends to the work by Zakharov and Filonenko (1968). It is based on four-wave interactions in the kinetic equation and gives good ...
Purpose: The aim of this study was to create, perfect and test a hyperthermia balloon catheter for local treatment of cholangiocarcinoma. The device should induce hyperthermia in tumor tissue by acting locally in the bile duct lumen in contact with the tumor-infiltrated duct wall. In addition, it should exert tissue compression to cause an appreciable reduction in tumor microvasculature flow, thus improving thermal performance. Methods: According to the design specifications, the working temperature range should allow the device to be used for hyperthermia therapy either in combination with radiation and/or chemotherapy(radio/chemo-sensitizing effect at 42-45 deg. C) or alone (induction of coagulation necrosis above 65 deg. C). The balloon serves as an anchoring system during treatment and as a functional element to induce tissue compression. In vitro mechanical evaluation of the pressure/volume relationship, with the balloon inside rigid ...
BackgroundMany difficult problems in evolutionary genomics are related to mutations that have weak effects on fitness, as the consequences of mutations with large effects are often...Full Text Available
Ketamine-anesthetized Sprague-Dawley rats were exposed in H orientation to far-field 9.3-GHz continuous-wave (CW) and pulsed (2 microseconds 500 pps) radiofrequency radiation (RFR) at average power densities of 30 and 60 mW/sq. cm (whole-body average specific absorption rates of 9.3 and 18.6 W/kg, respectively). Irradiation was conducted to cyclicly increase colonic temperature from 38.5 to 39.5 C. Colonic, tympanic, and subcutaneous temperatures, ECG, blood pressure, and respiratory rate were continuously recorded during experimentation. At both power densities, the subcutaneous and tympanic temperature increases significantly exceeded the colonic temperature increase. At both exposure levels, heart rate increased significantly during irradiation and returned to baseline when exposure was discontinued. Blood pressure and respiratory rate did not significantly change during irradiation. There were no significant differences between the effects ...
Radio frequency (RF) sheaths are suspected of limiting the performance of present-day ion cyclotron range of frequencies (ICRFs) antennas over long pulses and should be minimized in future fusion devices. Within the simplest models, RF-sheath effects are quantified by the integral VRF = ? E|| ? dl where the parallel RF field E|| is linked with the slow wave. On 'long open field lines' with large toroidal extension on both sides of the antenna it was shown that VRF is excited by parallel RF currents j|| flowing on the antenna structure. In this paper, the validity of this simple sheath theory is tested experimentally on the Tore Supra (TS) ITER-like antenna prototype (ILP), together with antenna simulation and post-processing codes developed to compute VRF. The predicted poloidal localization of high-|VRF| zones is confronted to that inferred from experimental data analysis. Surface temperature distribution on ILP front ...
We present a Hubble Space Telescope image of the FRII radio galaxy 3C 401, obtained at 1.6 microns with the NICMOS camera in which we identify the infrared counterpart of the brightest region of the radio jet. The jet has a complex radio structure and brightens where bending occurs, most likely as a result of relativistic beaming. We analyze archival data in the radio, optical and X-ray bands and we derive its spectral energy distribution. Differently from all of the previously known optical extragalactic jets, the jet in 3C401 is not detected in the X-rays even in a long 48ksec X-ray Chandra exposure and the infrared emission dominates the overall SED. We propose that the dominant radiation mechanism of this jet is synchrotron. The low X-ray emission is then caused by two different effects: i) the lack of any strong external photon field and ii) the shape of the electron ...
Radio, optical and X-rays telescopes are improving our knowledge of deep space. All these telescopes detect electromagnetic radiation at various frequencies. But a different kind of radiation is generated in the deeper space; it is the gravitational one. Gravitational waves change the space-time metric. As a consequence, GW telescopes should detect an extremely small strain (h < 10/sup -21/) of the geometry of a reference frame; if the frame has a reference dimension (L) of some kilometers, the deformation amplitude ( Delta L = h * L) is limited to 10/sup -16/ meters. Laser interferometers are the most suitable devices to make precise measurements of distances. Their resolution is limited by the laser wavelength ( lambda = 10/sup -6/ meters) and by the light wave-shift detection capability ( Delta Phi = 1 ppb). These theoretical limits are strongly degraded by different noise sources, which reduce the actual resolution ...
On the 8 and 9 May 2002 representatives of the National Radiological Protection Board (NRPB) performed a radiofrequency electromagnetic field survey in the Cookridge area of Leeds in order to assess exposure to radio signals from transmitters mounted on a water tower/a lattice tower and a radio station tower. Guidelines on limiting exposure to radio signals have been published by NRPB and the International Commission on Non-Ionizing Radiation Protection (ICNIRP). These guidelines are designed to prevent established adverse effects on human health. During this survey, the total exposures due to all radio signals from 30 MHz to 18000 MHz (18 GHz) were measured. This frequency range was chosen as it includes mobile phone base station transmissions, which are at around 900 and 1800 MHz and super high frequency (SHF) transmissions from most of the large microwave dish antennas mounted on ...
The Soldier Information Requirements Technology Demonstration (SIREQ TD) project is an experimentation program to identify technologies that significantly enhance the performance of our future soldiers. One of the study series involved a 2 x 2 factorial comparison of the benefits of digital maps over paper maps, and the use of radios vs. no radios. Thirty-two Canadian regular force infantry soldiers performed force-on-force tactical assault missions in wooded terrain, with each soldier participating in all four test conditions. The radios were configured to operate in 4 subnets: 1 channel for each of the 2 Assault Groups (4 soldiers on a channel); a Section Commander/2IC channel; and an all-users channel. Note that in the no-radio conditions soldiers still operated the press-to-talk switch to allow recording of communications, but the speaker volume was set to zero. All communications were date/time ...
The e/sup -/..-->..e/sup -/(..nu..nu-bar) process in the field of a circularly polarized plane wave is studied in the framework of the Glashow-Weinberg-Salam model. General expressions for the probability of creation of neutrino pairs are obtained, and the case of a low-intensity wave is studied in detail. The effects of asymmetry of emission of electron and muon neutrinos are estimated, and comparison with previous results is performed.
It is shown that the direct Fourier synthesization of light beams allows one to create polarity-asymmetric waves, which are able, in the process of nonlinear interaction with a medium, to break its inversion symmetry. As a result, these "polar" waves may show the effect of optical rectification in nonlinear centrosymmetric media by generating light-induced dc electric polarization. At the same time, the waves of this type, due to their unusual symmetry properties, can be used for detecting the direction and sign of a dc electric field applied to the medium. The prospects of application of polar waves to data recording and processing are discussed.
Recent developments in solid-state radio frequency (RF) power technologies allow for the practical consideration of RF heated plasmas for space propulsion. These technologies permit the use of any electrical power source, de-couple the power and propellant sources, and allow for the effcient use of both the propellant mass and power. Effcient use of the propellant is obtained by expelling the rocket exhaust at the highest possible velocity, which can be orders of magnitude higher than those achieved in chemical rockets. Handling the hot plasma exhaust requires the use of magnetic nozzles, and the basic physics of ion detachment from the magnetic eld is discussed. The plasma can be generated by RF using helicon waves to heat electrons. Further direct heating of the ions helps to reduce the line radiation losses, and the magnetic geometry is tailored to allow ion cyclotron resonance heating. RF eld and ion trajectory calculations are presented to ...
ITN Energy Systems is developing next-generation solar cells based on the concepts of an optical rectenna. ITN's optical rectenna consists of two key elements: (1) an optical antenna to efficiently absorb the incident solar radiation, and (2) a high-frequency metal-insulator-metal (MIM) tunneling diode that rectifies the AC field across the antenna, providing DC power to an external load. The combination of a rectifying diode at the feedpoints of a receiving antenna is often referred to as a rectenna. Rectennas were originally proposed in the 1960s for power transmission by radiowaves for remote powering of aircraft for surveillance or communications platforms. Conversion efficiencies greater than 85% have been demonstrated at radio frequencies (efficiency defined as DC power generated divided by RF power incident on the device). Later, concepts were proposed to extend the rectennas into the IR and optical region ...
Abstract Satellite measurements and numerical forecast model reanalysis data are used to compute an updated estimate of the cloud radiative effect on the global multi-annual mean radiative energy budget of the atmosphere and surface. The cloud radiative cooling effect through reflection of short wave radiation dominates over the long wave heating effect, resulting in a net cooling of the climate system of - 21 Wm-2. The short wave radiative effect of cloud is primarily manifest as a reduction in the solar radiation absorbed at the surface of - 53 Wm-2. Clouds impact long wave radiation by heating the moist tropical atmosphere (up to around 40 Wm-2 for global annual means) while enhancing the radiative cooling of the atmosphere over other regions, in particular higher latitudes and sub-trop...
In this review, we give a brief introduction to the application of the new technique of transformation acoustics, which draws on a correspondence between coordinate transformation and material properties. The technique is formulated for both acoustic waves and linear liquid surface waves. Some interesting conceptual devices can be designed for manipulating acoustic waves. For example, we can design acoustic cloaks that make an object invisible to acoustic waves, and the cloak can either encompass or lie outside the object to be concealed. Transformation acoustics, as an analog of transformation optics, can go beyond invisibility cloaking. As an illustration for manipulating linear liquid surface waves, we show that a liquid wave rotator can be designed and fabricated to rotate the wave front. The acoustic transformation media require ...
Atmospheric and ionospheric perturbations associated with the acoustic-gravity waves (AGW) with typical frequencies of a few hertz -millihertz are considered. These events may be caused by the influence from space and atmosphere as well as by oscillations of the Earth surface and other near-surface phenomena. The surface sources include long-period oscillations of the Earth's surface, earthquakes, explosions, thermal heating, seisches and tsunami waves. The wavelike phenomena manifest themself as travelling disturbances of air (in the atmosphere) and of electron density (in the ionosphere). Travelling ionospheric disturbances (TIDs) are well detected by radio physical methods. AGW generation by near-surface sources is modeled by the numerical solution of the equation of geophysical fluid dynamics for different sources in two-dimensional non-linear dissipative compressible atmosphere. The numerical calculations are based on ...
This paper focuses on potential effects of solar phenomena on communication systems used by the electric utility industry. It begins with a discussion of solar phenomena fundamentals and discussion of the interaction between solar emissions and the earth's ionosphere and magnetosphere. It continues with a discussion of the resulting impacts on communication systems including radio, satellite, wireline, fiber optic, and powerline systems and concludes with a discussion of mitigation techniques and a call for observers to report suspected solar impact experiencexperiences.
Some biologicaleffects of hypoglycin-A, a compound isolated from the fruit of Blighia sapida, have been investigated. Administration of this compound to animals caused drowsiness...Full Text Available
... abundance though an effect on escapement. The lobster aquaculture model continues to be updated as new biological ... become available. A monograph on the economics of aquaculture is near completion....
The results of radon concentration measurements inside of the Gabriel caves of Mexico, during three consecutive two-month periods covering almost three seasons, are reported in the present work. The radio-ecological importance of this site is related to the radon and its concentration-dynamic behavior in the cave. Further interest in radiation safety motivated this initiative since routine biological field work is done, with people spending long periods of time there. CR-39 passive nuclear track detector was chosen for this survey. Radon concentration levels decrease during the rainy season and show different values depending on the ventilation and geometeorological structure. Measured values range between 956 and 4931Bqm{sup -3}, an indication that radon doses may exceed the allowed values for workers. This project is part of a larger study of indoor radon alpha emitters in Mexican caves.
The results of radon concentration measurements inside of the Gabriel caves of Mexico, during three consecutive two-month periods covering almost three seasons, are reported in the present work. The radio-ecological importance of this site is related to the radon and its concentration-dynamic behavior in the cave. Further interest in radiation safety motivated this initiative since routine biological field work is done, with people spending long periods of time there. CR-39 passive nuclear track detector was chosen for this survey. Radon concentration levels decrease during the rainy season and show different values depending on the ventilation and geometeorological structure. Measured values range between 956 and 4931Bqm-3, an indication that radon doses may exceed the allowed values for workers. This project is part of a larger study of indoor radon alpha emitters in Mexican caves.
It was developed a new formulation of macro aggregates of Samarium 153 ({sup 153} Sm-MH) for the arthropaties treatment. The radio pharmaceutic was prepared by reaction of Samarium 153 chloride (SmCl{sub 3}) in aqueous environment with sodium boron hydride in NaOH 0.5 N. The microscopic analysis shown that the particles have an average size of 4% m (range 1-14 {mu} m). The velocity of sedimentation was 0.008 cm/min with high stability in vitro in human serum. The biological studies in healthy rabbits, shown that the complex is retained inside the articulation still eight days after of the administration of the radiopharmaceutical. Likewise, it is presented the data of absorbed dose in the different target organs, which was determined by thermoluminescent dosimetry (TLD) through the use of a REMCAL phantom (radiation equivalent manikin calibration). (Author)
Observations show the ubiquitous presence of propagating magnetohydrodynamic (MHD) kink waves in the solar atmosphere. Waves and flows are often observed simultaneously. Due to plasma inhomogeneity in the perpendicular direction to the magnetic field, kink waves are spatially damped by resonant absorption. The presence of flow may affect the wave spatial damping. Here, we investigate the effect of longitudinal background flow on the propagation and spatial damping of resonant kink waves in transversely nonuniform magnetic flux tubes. We combine approximate analytical theory with numerical investigation. The analytical theory uses the thin tube (TT) and thin boundary (TB) approximations to obtain expressions for the wavelength and the damping length. Numerically, we verify the previously obtained analytical expressions by means of the full solution of the ...
The modular and periodic antenna structure in TCA is shown to produce an extremely pure spectrum of excited waves. This purity, together with precise measurements of the antenna loading in different parts of the spectrum, has allowed us to demonstrate that it is essential to include both toroidal coupling and the Hall effect (#omega#/#omega#/sub c//sub i/not =0) in order to explain our results. We show that toroidicity produces coupling from the directly excited Vertical BarmVertical Bar = 1 wave to Vertical BarmVertical Bar = 0,2 waves. Discrete Alfven Waves are also seen for Vertical BarmVertical Bar = 0,2 in addition to the directly driven Vertical BarmVertical Bar = 1. The importance of the Hall effect is most visible when a travelling wave is excited, in which case the antenna loading depends on the direction of the ...
The effect of the wind on the sustain of extreme water waves is investigated experimentally and numerically. A series of experiments conducted in the Large Air-Sea Interactions Facility (LASIF) showed that a wind blowing over a strongly nonlinear short wave group due to the linear focusing of a modulated wave train may increase the life time of the extreme wave event. The expriments suggested that the air flow separation that occurs on the leeward side of the steep crests may sustain longer the maximum of modulation of the focusing-defocusing cycle. Based on a Boundary-Integral Equation Method and a pressure distribution over the steep crests given by the Jeffreys'sheltering theory, similar numerical simulations have confirmed the experimental results
The emission of the plerion G21.5-0.9 appears more extended in X rays than in radio. This is an unexpected result because it would imply that short-lived X-ray electrons may reach distances even larger than radio electrons. Applying an empirical relationship between dust scattering optical depth and photoelectric column density, the measured column density leads to a large optical depth at 1 keV, of about 1. Therefore we investigate the hypothesis that the detected halo be an effect of dust scattering, re-analyzing an Cal/PV XMM-Newton observation of G21.5-0.9 and critically examining it in terms of a dust scattering model. We also present a spectral analysis of a prominent extended feature in the northern sector of the halo.
The contents include: Detailed index for 1991; Data for November 1991--Solar-terrestrial environment, IUWDS alert periods (advance and worldwide), Solar activity indices, Solar flares, Solar radio emission, Stanford mean solar magnetic field; Data for October 1991--Solar active regions, Sudden ionospheric disturbances, Solar radio spectral observations, Cosmic ray measurements by neutron monitor, Geomagnetic indices; Late data--Cosmic ray measurements by neutron monitor (Climax February and May 1990, Deep River May-August 1991), Geomagnetic indices (Sudden commencements/Solar flare effects January-May 1991); Errata--August 1991 Geomagnetic activity indices.
Long before possible organic effects, exposure to ionizing radiations can provoke anxiety. In front of invisibility, the imagination quickly ignites. The terrorists have perfectly understood it. They are ready to use ionizing radiations as a weapon to remind traumatic images deeply rooted in people's memory. These images induce anxiety with all the clinical expressions connected to it. These symptoms require to be treated because of a possible anarchic development. For that purpose, plans have been elaborated to coordinate the different professional's actions. The coherence of medical management and communication aims to allow the most implicated people to find the way to face the events. When it is not possible, medico-psychological cells permit a specialized care. (author)
Apparent evolution of relativistic flows as traced by radio emission results from a combination of several factors related to propagation of relativistic blobs or shocks, velocity, density and pressure stratification of the underlying flow, plasma instability and (possibly also) phase and time travel effect. This combination can create an intricate and chaotic patterns of the observed morphological changes in radio emission, which complicates the analysis and interpretation of kinematic and physical properties of the jet plasma. Recent studies have indicated that slow and quasi-stationary patterns in jets are most likely formed by plasma instabilities while faster, superluminally moving patterns are related to highly relativistic plasma condensations produced by the nuclear flares. Some of the stationary patterns may also be related to recollimation shocks or locations where strong non-thermal continuum is produced in jets. ...
Measurement of redshifted 21-cm emission from neutral hydrogen promises to be the most effective method for studying the reionisation history of hydrogen and, indirectly, the first galaxies. These studies will be limited not by raw sensitivity to the signal, but rather, by bright foreground radiation from Galactic and extragalactic radio sources and the Galactic continuum. In addition, leakage due to gain errors and non-ideal feeds conspire to further contaminate low-frequency radio obsevations. This leakage leads to a portion of the complex linear polarisation signal finding its way into Stokes I, and inhibits the detection of the non-polarised cosmological signal from the epoch of reionisation. In this work, we show that rotation measure synthesis can be used to recover the signature of cosmic hydrogen reionisation in the presence of contamination by polarised foregrounds. To achieve this, we apply the rotation measure ...
Efforts during the past year by the US Department of Energy and the Electric Power Research Institute-funded laboratories to investigate the biologicaleffects from electric fields are described in resume form. Investigations generally have been summarized with objectives, accomplishments of the past year, and some indication of projected studies.
In this experiment, a beam incident from an oblique direction is reflected by a spherical lens toward the direction of incidence. When the surface of a matter is vibrated by elastic waves, the spherical lens comes into a translation motion that accompanies the vibration. It follows accordingly that the vibration on the surface of the matter may be detected by sensing the spherical lens travelling speed. Three components of the vibration may be determined if beams are focused at one spot from three directions. Detection of the S-wave component by LDV (laser Doppler vibrometer) discloses the complicated wave field in a heterogeneous material, and this physical model experiment may be utilized in various fields of study. For instance, information about problems that may surface in the field work may be collected beforehand in a physical model experiment for developing an S-wave-aided probing method. For ...
The advantages of radiofrequency and microwaves, such as volumetric heating, rapid and selective heating, compactness of equipment and ease of operation, offer sound economic alternative heating techniques. This article discusses dielectric loss, its quantification, and how it is put to effective use, including the use of applicators. Brief recommendations are presented for whether to select radio frequency or microwaves for a particular application. Uses of radiofrequency and microwaves in the industrial, domestic and medical sectors are described.
A new technique is described in this paper for a general active radio frequency (RF) filter trap that can be used for suppressing noise or interference on high voltage (HV) transmission lines. The technique exploits the Miller effect of an RF amplifier in conjunction with a special sensing circuit, and is potentially far more economical to implement than conventional techniques that use passive HV filter components.
An animated test is made for mice with malignant tumors irradiated by a self-made millimetre wave radiator for medical purpose. It is observed that S-180 sarcomas in mice after irradiation has been distinctly suppressed. And remarkable effects are shown through a lot of clinical practices on peptic ulcer, skin-deep ulcer, acute and chromic soft tissue injuries etc.
Acoustic waves propagation of in composite of water with embedded double-layered silicone resin/silver rods is considered. Approximate values of effective dynamical constitutive parameters are obtained. Frequency ranges of simultaneous negative constitutive parameters are found. Localized surface states on the interface between metamaterial and ``normal'' material are found. Doppler effect in metamaterial is considered. Presence of anomalous modes is shown.
Heat production in biological materials due to absorption of radiowaves and microwaves can be used in applications as diverse as cancer treatment and cooking. However, the hazards of overexposure range from hyperthermia to cataracts and internal burns. To maximize the clinical benefits and minimize potential hazards, the biologicaleffects of radiowaves and microwaves must be understood. Dielectric measurements can be used to determine the extent of such effects in various applications and at various levels of exposure. The values of maximum permissible exposure levels that are likely to be recommended aeat production in biological materials due to absorption of radiowaves and microwaves can be used in applications as diverse as cancer treatment and cooking. However, the hazards of overexposure range from hyperthermia to cataracts and internal burns. To maximize the clinical ...
Gravitational parity violation is a possibility motivated by particle physics, string theory and loop quantum gravity. One effect of it is amplitude birefringence of gravitational waves, whereby left and right circularly-polarized waves propagate at the same speed but with different amplitude evolution. Here we propose a test of this effect through coincident observations of gravitational waves and short gamma-ray bursts from binary mergers involving neutron stars. Such gravitational waves are highly left or right circularly-polarized due to the geometry of the merger. Using localization information from the gamma-ray burst, ground-based gravitational wave detectors can measure the distance to the source with reasonable accuracy. An electromagnetic determination of the redshift from an afterglow or host galaxy yields an independent measure ...
Project ZEUS was designed to characterize the effects of long-term gamma irradiation on free-ranging meadow voles, and to determine the lowest level of radiation at which biologicaleffects are discernible in the population. Behavioural tests are consider...
Abstracts of research projects are presented in the following areas: measurements and special facilities; cellular and subcellular studies; physiology; behavior; environmental effects; modeling, scaling and dosimetry; and high voltage direct current. (ACR)
Rats were exposed to aerosols of "2"3"3U and "2"3"2U nitrate in a study of the long-term biologicaleffects. Preliminary radiation dose estimates show lung > skeleton > kidney in each dose group.
3,4-Methylenedioxymethamphetamine (MDMA) is an amphetamine derivative that elicits complex biologicaleffects in humans. One plausible mechanism for this phenomenon is that racemic MDMA is composed...Full Text Available
PurposeTaxanes have effects on angiogenesis causing difficulties in separating biologiceffects of chemotherapy from those due to angiogenesis inhibitors. This randomized...Full Text Available
A previous paper introduced the use of wave digital filters as a basic building block for power system simulation, particularly suitable for real-time applications. This paper stresses the simulation of non-linear and switching elements, emphasizing the advantages of the wave filters implementation. The digital structure is maintained even when non-linear components change their characteristics or power electronic devices switch their states. As a very important by-product, the suppression of numerical oscillations related to the trapezoidal rule is achieved in a rather simple way, with no effects on simulation results.
The influence of motion of ions and electron temperature on nonlinear one-dimensional plasma waves with velocity close to the speed of light in vacuum investigated. It is shown that although the wavebreaking field weakly depends on mass of ions, the nonlinear relativistic wavelength essentially changes. The nonlinearity leads to the increase of the strong plasma wavelength, while the motion of ions leads to the decrease of the wavelength. Both hydrodynamic approach and kinetic one, based on Vlasov-Poisson equations, are used to investigate the relativistic strong plasma waves in a warm plasma. The existence of relativistic solitons in a thermal plasma is predicted.
Abstract in english We present a detailed derivation of the effective dielectric constant to be used in the dispersion relation for electrostatic waves in the case of a plasma immersed in a inhomogeneous magnetic field, with inhomogeneity perpendicular to the direction of the magnetic field.
Purpose: Previous data suggest that the PKC? catalytic V5 (PKC?-V5) heptapeptide (HEPT) (FEQFLDI) binds HSP27 and blocks HSP27-mediated radio- or chemoresistance. Here we investigated further the in vivo function of the PKC?-V5 HEPT. Methods and Materials: Labeling of HEPT with Cy5.5 or fluorescein isothiocyanate was performed to evaluate in vitro or in vivo distribution of HEPT. A clonogenic survival assay, flow cytometry, and Western blotting of cleaved caspase-3 were performed to determine in vitro sensitization effects of HEPT plus ionizing radiation (IR) versus IR alone or those of HEPT plus cisplatin(Cis) versus Cis alone. A nude mouse xenografting system was also applied to detect in vivo sensitizing effects of HEPT. Results: HEPT efficiently bound to HSP27 and showed sensitization after combined treatment with IR versus treatment with Cis alone in NCI-H1299 lung carcinoma cells, with higher HSP27 expression, which ...
Power extraction using a dielectric-loaded (DL) waveguide is a way to generate high-power radio frequency (RF) waves for future particle accelerators, especially for two-beam-acceleration. In a two-beam-acceleration scheme, a low-energy, high-current particle beam is passed through a deceleration section of waveguide (decelerator), where the power from the beam is partially transferred to trailing electromagnetic waves (wakefields); then with a properly designed RF output coupler, the power generated in the decelerator is extracted to an output waveguide, where finally the power can be transmitted and used to accelerate another usually high-energy low-current beam. The decelerator, together with the RF output coupler, is called a power extractor. At Argonne Wakefield Accelerator (AWA), we designed a 7.8GHz power extractor with a circular DL waveguide and tested it with single electron bunches and bunch trains. The output RF ...
Overhead, high power transmission lines have secured rights of way on agricultural lands in Minnesota. The economic impact of such utility crossings, including effects on land price, was investigated. Sale records and survey data were analyzed. Buyers, sellers, and brokers were interviewed concerning inconvenience, radio interference, appearance, and loss of irrigation possibilities due to the transmission lines. In nine affected sales, there was only one case in which less money was indicated for the farm because of the presence of a transmission line.
Overhead, high power transmission lines have secured rights of way on agricultural lands in Minnesota. The economic impact of such utility crossings, including effects on land price, was investigated. Sale records and survey data were analyzed. Buyers, sellers, and brokers were interviewed concerning inconvenience, radio interference, appearance, and loss of irrigation possibilities due to the transmission lines. In nine affected sales, there was only one case in which less money was indicated for the farm because of the presence of a transmission line.
Two-wave mixing in sillenite crystals such as bismuth silicon oxide (Bi12SiO20) and bismuth titanium oxide (Bi12TiO20) of (001)- and (221)-cuts for counterpropagating geometry was studied within the frame of slowly varying amplitude approximation. Electrooptic, photoelastic, piezoelectric, self-diffraction effects and optical activity were taken into account.
We report an observation of a delayed all-optical routing/switching phenomenon based on ultraslow group velocity of light via nondegenerate four-wave mixing processes in a defected solid medium. Unlike previous demonstrations of enhanced four-wave mixing processes using the slow light effects, the present observation demonstrates a direct retrieval of the resonant Raman-pulse excited spin coherence into photon coherence through coherence conversion processes.
The t<0 branch of pre-big bang cosmological scenarios is subject to a gravitational wave instability. The unstable behaviour of tensor perturbations is derived in a very simple way in Hwang's covariant and gauge-invariant formalism developed for extended theories of gravity. A simple interpretation of this instability as the effect of an ''antifriction'' is given, and it is argued that a universe must eventually enter the expanding phase. (orig.)
This report focuses on a better understanding of the physical phenomenon related to the enhancement of boiling and non-boiling heat transfer by applying ultrasonic waves. Experimental results obtained both in a pool of water and in a vertically upward water flow proved clearly that macroscopic acoustic steam induced by ultrasonics is a major contribution to heat transfer augmentation. (author).
This report focuses on a better understanding of the physical phenomenon related to the enhancement of boiling and non-boiling heat transfer by applying ultrasonic waves. Experimental results obtained both in a pool of water and in a vertically upward water flow proved clearly that macroscopic acoustic stream induced by ultrasonics is a major contribution to heat transfer augmentation. (author).
Calculations of the Compton profiles for the transition metals Ta and W are performed, using electron wave functions obtained from self-consistent augmented plane wave (APW) band structure calculations within the local density formalism of Hedin-Lundqvist. Relativistic effects are included except for the spin-orbit interaction. The observed structures of the Compton profiles in these metals are understood in terms of the topology of their Fermi surfaces. (author).
Fermi radii and velocities are determined by deconvoluting de Haas-van Alphen data. Comparison of these data with accurate augmented-plane-wave band-structure results establishes the reliability of the augmented-plane-wave calculations and allows a determination of the anisotropic many-body enhancement factor lambda(k). The Fermi-surface average of 1.33 suggests a large electron-electron contribution. Our anisotropic lambda(k) porvides a detailed test and guide for model calculations of many-body enhancement.
We present two applications of CR-39 to estimate biologicaleffects of heavy ion irradiation. The accurate measurement of fluence of ions using CR-39 is indispensable to calculate the action cross sections for biologicaleffects. Ions with 6 MeV/n at the Medium Energy Beam Course, HIMAC (NIRS) were extracted to the air, and degraded with the air. DNA and living cells were irradiated by ions with various specific energies at several air columns along with the Bragg curve. DNA strand breaks and cell killing were measured and the results were converted to the action cross sections using the fluence measured with CR-39 at the irradiation positions. Another example of the application of CR-39 is to identify whether the ions with a specific energy pass through the cell or stop within the cell. (author)
Most of all research reactors are immerged in the deep water pool to be a ultimate heat sink. At the neighbor of the reactor, some radio-active matters, such as Na-24, Ar-41, Mg-27, Al-28 and etc, may be generated by the neutron irradiation. Those radio-active isotopes may rise up to the pool water surface through the natural convection flow, which can make the radioactivity in the reactor hall rise high enough to concern about the health of people working in the reactor hall. When the irradiation test facilities are loaded or unloaded during a normal operation, the highly radio-activated primary coolant may flow out through the irradiation test holes on the top of the reactor. This also may be a main hazard source to make the working environment of the reactor hall bad. Making a hot water layer 1.5 ? 2.0 m thick at the top of reactor pool would be a good measure to resolve that problem. The hot water layer is formed by a ...
A mechanical model with local resonators is proposed as an acoustic metamaterial that exhibits an unusual frequency-dependent effective stiffness. If treated as an equivalent elastic solid, its effective Young's modulus can become unbounded or vanishingly small at two respective frequencies. Moreover, in a certain frequency range, the effective Young's modulus would become negative, resulting in a band gap that coincides with this frequency range. The wave attenuation behavior and mechanism are studied through numerical simulations on the acoustic metamaterial model. The capability of the metamaterial to selectively block or filter unwanted waves is demonstrated by a numerical simulation example.
This study evaluates the effect of gamma radiation on the viability of fungi and actinomycetes that contaminate medicinal plants. The relationship between the total lipids of some fungi and actinomycetes and their sensitivity to gamma radiation is also investigated. The data reveal that the viable counts of these florae decrease approximately exponentially with the radiation dose, the effective dose for the elimination of these microorganisms being about 5 kGy for all the medicinal plants under study. Response of pure cultures of fungi and actinomycetes isolated from medicinal plants to increasing absorbed doses of gamma radiation indicate that an increase in radioresistance is in the following order: Streptomyces rimosus, Fusarium solani, Nocardia kuroishii. F. oxysporum, A. fumigatus, A. flavus, A. parasiticus and A. ochraceus. The total lipid contents of molds and actinomycetes have been reported to be increased by increasing the ...
A fundamental Doppler-like but asymmetric waveeffect that shifts received signals in frequency in proportion to their respective source distances, was recently described as means for a whole new generation of communication technology using angle and distance, potentially replacing TDM, FDM or CDMA, for multiplexing. It is equivalent to wave packet compression by scaling of time at the receiver, converting path-dependent phase into distance-dependent shifts, and can multiply the capacity of physical channels. The effect was hitherto unsuspected in physics, appears to be responsible for both the cosmological acceleration and the Pioneer 10/11 anomaly, and is exhibited in audio data. This paper discusses how it may be exploited for instant, passive ranging of signal sources, for verification, rescue and navigation; incoherent aperture synthesis for smaller, yet more accurate radars; universal immunity to ...
We present the results of a study on the 1.4 GHz kpc-scale radio emission in the complete flux density limited MOJAVE sample, comprising 135 radio-loud AGNs. While extended emission is detected in the majority of the sources, about 7% of the sources exhibit only radio core emission. Many BL Lacs exhibit extended radio power and kpc-scale morphology typical of powerful FRII jets, while a substantial number of quasars possess radio powers intermediate between FRIs and FRIIs. This poses challenges to the simple radio-loud unified scheme, which links BL Lacs to FRIs and quasars to FRIIs. We find a significant correlation between extended radio emission and pc-scale jet speeds: the more radio powerful sources possess faster jets. This indicates that the 1.4 GHz (or low frequency) radio emission is indeed ...
The present work concerns the numeric modeling of the sea-wave instability under the effect of the logarithmic-wind profile at hurricane conditions. Non-linear effects, such as wave breaking, foam production, etc. Powell et al. (2003), Shtemler et al. (2010) are ignored. The central point of the study is the calculation of the wave growth rate, which is proportional to the fractional input energy from the wind to the wave exponentially varied with time. The present modeling demonstrates that the Miles-type model applying Charnock's formula for roughness to the hurricane-wind parameters underestimates the growth rate from 5 to 40 times as compared with the model employing the roughness and friction velocity adopted from experimental data for hurricane winds.1 This occurs due to Charnock's formula fails at large wind speeds. The stability characteristics found on ...
The present work concerns the numeric modeling of the sea-wave instability under the effect of the logarithmic wind at hurricane conditions (ignoring non-linear effects, such as wave breaking, foam production, etc. Powell et al. (2003)^1, Shtemler et al. (2003)^2. The central point of the study is the calculation of the growth rate, which is proportional to the fractional input energy from the wind to the wave exponentially varied with time. The present modeling demonstrates that the Miles-type model applying Charnock's formula Charnock (1955)^3 for roughness to the hurricane -wind parameters underestimates the growth rate of the wind waves 5-40 times as compared with the model employing the roughness and friction velocity adopted from experimental data for hurricane winds.^1 This occurs due to Charnock's formula fails at large wind speeds. The stability ...
In this report, I surveyed the cognitive radio technique in wireless networks. Researched several kinds of cognitive techniques about their advantages and disadvantages.
Current genome-wide association studies (GWAS) are moving towards the use of large cohorts of primary cell lines to study a disease of interest and to assign biological relevance to the genetic signals...Full Text Available
In recent years, the interest in the use of bacteria for biological control of plant-pathogenic fungi has increased. We studied the possible side effects of coating barley seeds with the antagonistic...Full Text Available
Oxidative stress contributes to the pathophysiology of exposure to heavy metals/metalloid. Beneficial renal effects of some medications, such as chelation therapy depend at least partially on the ability...Full Text Available
Organisms in the genus Mycobacterium cause a variety of human diseases. One member of the genus, M. ulcerans, causes a necrotizing skin disease called Buruli ulcer....Full Text Available
BackgroundModeling of a complex biological process can explain the results of experimental studies and help predict its characteristics. Among such processes is transcription in...Full Text Available
Exploring the possibility of enhancing the properties of baculoviruses as biological control agents of insect pests, we tested the effect of expressing an insect gene (jhe) encoding juvenile hormone...Full Text Available
ObjectiveTo evaluate the effect of different concomitant disease modifying antirheumatic drugs (DMARDs) on the persistence with antitumour necrosis factor (anti-TNF) therapies in...Full Text Available
Experimental techniques are presented that can be used to assay and correct for differential light scattering effects in circular dichroism spectra of biological macrostructures. The assay is based...Full Text Available
Loss of biological diversity because of extinction is one of the most pronounced changes to the global environment. For several decades, researchers have tried to understand how changes in biodiversity...Full Text Available
The liver plays a vital role in glucose homeostasis, the synthesis of bile acids and the detoxification of foreign substances. Liver culture systems are widely used to test adverse effects of drugs...Full Text Available
The biological and radiobiological peculiarities of seeds and seedlings of the Rumex confertus and Lupinus polycolor plants, which grown during several generations in plots with different level of radionuclide pollution of the Chernobyl exclusive zone have been investigated.
The negative consequences of baling hay before it is adequately dried are widely known to producers. Frequently, these problems are created by uncooperative weather conditions that prevent forages from drying (rapidly) to moisture levels that allow safe and stable storage of harvested forages. When ...
Biodegradation/solubilization of coal is described. The degradation of dibenzothiophene by two bacterial strains is reported. The effects of adding salicylate to the treatments was also investigated. 2 figs., 5 tabs. (CBS)
Radionuclides are distributed nonuniformly in tissue. The present work examined the impact of nonuniformities at the multicellular level on the lethal effects of 210Po. A three-dimensional...Full Text Available
Using a sample of 30,000 quasars from SDSS-DR7, we explore the range of properties exhibited by high-ionization, broad emission lines, such as CIV 1549. Specifically we investigate the anti-correlation between L_UV and emission line EQW (the Baldwin Effect) and the "blueshifting" of high-ionization emission lines. The blueshift of the CIV emission line is nearly ubiquitous, with a mean shift of 810 km/s for radio-quiet (RQ) quasars and 360 km/s for radio-loud (RL) quasars, and the Baldwin Effect is present in both RQ and RL samples. Composite spectra are constructed as a function of CIV emission line properties in attempt to reveal empirical relationships between different line species and the SED. Within a two-component disk+wind model of the broad emission line region (BELR), where the wind filters the continuum seen by the disk component, we find that RL quasars are consistent with being dominated by ...
A new type of radiation which occurs when particles are accelerated in the field of a longitudinal wave and in a transverse magnetic field is studied. The characteristics of such spontaneous radiation are obtained, and the influence of collective effects on the radiation is analyzed. The application of the findings to the theory of free electron lasers is discussed. 8 references.
This text-book (electronic book - multi-media CD-ROM) constitutes a course-book - author's collection of lectures. It consists of 13 lectures in which the reader acquaints with the basis of radiobiology: Introduction to radiobiology; Physical fundamentals of radiobiology; Radiation of cells; Modification of radiation damage of cells; Reparation of radiation damage of cells; Radiation syndromes and their modification; Radiation injury; Radiation damage of tissues; Effect of radiation on embryo and fetus; Biologicaleffects of incorporated radionuclides; Therapy of acute irradiation sickness; Delayed consequences of irradiation; Radiation oncology and radiotherapy. This course-book may be interesting for students, post-graduate students of chemistry, biology, physics, medicine as well as for teachers, scientific workers and physicians. (author)
In the present study, the authors examine the interactions of pentavalent technetium ions (TcO/sup 3+/) with the basic form of the lasalocid A in pure methanol solvent and in methanol-water mixtures. There are a number of reasons for such a study. First, the interactions of technetium ions with biologically important compounds are of considerable importance owing to the widespread use of /sup 99m/Tc in diagnostic radio-imaging. Second, lasalocid A is known to transport metal ions across phospholipid bilayer membranes and between the aqueous cores of phospholipid inverse micelles. Third, lasalocid A is known to bind and solubilize metal ions in bulk organic liquid phases. Fourth, the conformation adopted by lasalocid A on interaction with TcO/sup 3+/ appears to be different than those found in most other cases and circumstances. Fifth, it may also be possible to use the competition of TcO/sup 3+/ with other, physiologically relevant cations ...
WASAG DECON developed a concept for the biological in situ remediation of an TNT-contaminated former seepage pond. This pond is located on the site of an ammunition factory in Lower Saxony. Unit 1982 all the waste water from the production buildings was directed into this pond, including TNT-contaminated water from the flushing of shells. Due to this practice, the sediment of the pond, the underlying soil and the groundwater became contaminated with TNT. The area of the soil contamination adds to abut 2.000 m{sup 2}. The remediation concept includes three steps: 1. Excavation of the most highly contaminated soil with TNT-concentrations above 1000 mg/kg. 2. Reduction of the remaining contamination by a biological in situ treatment using organic and inorganic amendments and mechanical tillage. After about to years of treatment, remediation goals of 50 mg/kg are expected to be reached on most of the area. 3. Contaminations eventually remaining in ...
The temperature elevations in anatomically based human phantoms of an adult and a 3-year-old child were calculated for radio-frequency whole-body exposure. Thermoregulation in children, however, has not yet been clarified. In the present study, we developed a computational thermal model of a child that is reasonable for simulating body-core temperature elevation. Comparison of measured and simulated temperatures revealed thermoregulation in children to be similar to that of adults. Based on this finding, we calculated the body-core temperature elevation in a 3-year-old child and an adult for plane-wave exposure at the basic restriction in the international guidelines. The body-core temperature elevation in the 3-year-old child phantom was 0.03 deg. C at a whole-body-averaged specific absorption rate of 0.08 W kg{sup -1}, which was 35% smaller than in the adult female. This difference is attributed to the child's higher body surface ...
This article describes the nature of the electromagnetic waves, what they are and how do they affect us. Current concern is focused on exposure to low level power-frequency magnetic fields like microwave radiation from mobile phones and leaking microwave ovens; high power radiation from defence and airport radars; fields close to high voltage transmission lines; radio frequency fields from industrial welders and heaters and DC magnetic fields in aluminium smelters. These fields with frequency less than 300 GHz do not carry sufficient energy to break chemical bonds and it is assumed that they cannot damage cell DNA. The amount of radiation absorbed by a human exposed to far field electromagnetic radiation (EMR) depends on the orientation and size of the person. In the 30-300 MHz range it is possible to excite resonance in the whole or partial body such as the head. It is emphasised that since there are some evidence that electromagnetic fields ...
Gamma-Ray Bursts (GRBs) are thought to originate at cosmological distances from the most powerful explosions in the Universe. If GRBs are not beamed then the distribution of their number as a function of gamma-ray flux implies that they occur once per (0.3-40) million years per bright galaxy and that they deposit >10^{53} ergs into their surrounding interstellar medium. The blast wave generated by a GRB explosion would be washed out by interstellar turbulence only after tens of millions of years when it finally slows down to a velocity of 10 km/s. This rather long lifetime implies that there could be up to several tens of active GRB remnants in each galaxy at any given time. For many years, radio observations have revealed the enigmatic presence of expanding neutral-hydrogen (HI) supershells of kpc radius in the Milky Way and in other nearby galaxies. The properties of some supershells cannot be easily explained in terms of conventional ...
New fish cans were prepared in the Institute of Fish Industry, Burgas (BG), containing pectin and additives. A biological experimental study was conducted to investigate the decontaminating effect of the new products. The results demonstrated no decontaminating effect in relation to radiocesium and radiostrontium. A pronounced prophylactic effect was observed in case of external irradiation, judged by endogenous spleen colonies. (author).
The standing-wave free-electron laser (FEL) differs from a conventional linear-wiggler microwave FEL in using irises along the wiggler to form a series of standing-wave cavities and in reaccelerating the beam between cavities to maintain the average energy. The device has been proposed for use in a two-beam accelerator (TBA) because microwave power can be extracted more effectively than from a traveling-wave FEL. The standing-wave FEL is modeled in the continuum limit by a set of equations describing the coupling of a one-dimensional beam to a TE{sub 01} rectangular-waveguide mode. Analytic calculations and numerical simulations are used to determine the time variation of the reacceleration field and the prebunching required so that the final microwave energy is the same in all cavities. The microwave energy and phase are found to be insensitive to modest spreads in the beam energy ...
Formulation is introduced for discretizing a boundary integral equation into an indirect boundary element method for the solution of 3-dimensional topographic problems. Yokoi and Takenaka propose an analytical solution-capable reference solution (solution for the half space elastic body with flat free surface) to problems of topographic response to seismic motion in a 2-dimensional in-plane field. That is to say, they propose a boundary integral equation capable of effectively suppressing the non-physical waves that emerge in the result of computation in the wake of the truncation of the discretized ground surface making use of the wave field in a semi-infinite elastic body with flat free surface. They apply the proposed boundary integral equation discretized into the indirect boundary element method to solve some examples, and succeed in proving its validity. In this report, the equation is expanded to deal with ...
In May 1990 a group of scientists representing several federal agencies, the International Society of Regulatory Toxicology and Pharmacology, the private sector, and academia met to develop a strategy to encourage the study of the biologicaleffects of low level exposures (BELLE) to chemical agents and radioactivity. A workshop was held in 1991 with seven invited speakers focusing on the toxicological implications of biological adaptations. The selection of topics and speakers was designed to consider critically the concept of hormesis, not only in a broad, conceptual manner, but also at the molecular and biochemical levels. These presentations offered a complementary perspective on the diverse range of molecular mechanisms that can become activated at low levels of toxicant exposure. In addition to chemical toxicology research, an overview of current research on 'Effects of low-dose radiation on the ...
In its 1990 recommendations, the ICRP considered the radiation risks after exposure during prenatal development. This report is a critical review of new experimental animal data on biologicaleffects and evaluations of human studies after prenatal radiation published since the 1990 recommendations. Thus, the report discusses the effects after radiation exposure during pre-implantation, organogenesis, and fetogenesis. The aetiology of long-term effects on brain development is discussed, as well as evidence from studies in man on the effects of in-utero radiation exposure on neurological and mental processes. Animal studies of carcinogenic risk from in-utero radiation and the epidemiology of childhood cancer are discussed, and the carcinogenic risk to man from in-utero radiation is assessed. Open questions and needs for future research are elaborated. The report reiterates that the ...
The types of investigations undertaken to test for possible biologicaleffects of extremely low frequency electric fields have been numerous. However, neither animal and plant experimentation nor clinical studies nor experience with operating extremely high voltage transmission lines have to date provided convincing evidence of a harmful effect from exposure to electric fields associated with transmission lines in spite of numerous attempts to find such effects. Analysis of internal fields and currents supports these observations as the levels appear to be too low to affect mammalian cells. Thus, while one can never prove the negative (i.e. that there is no effect), the overwhelming body of evidence indicates that the electric fields associated with high-voltage lines have no deleterious biologicaleffects. (author).
Radio frequency (RF) plasma nitriding using different input plasma processing powers (250-600 W) improves the surface of titanium by forming hard phases of TiN, Ti{sub 2}N, and Ti (N) into the surface. The characteristics of the compound layer have been investigated by optical microscopy, microhardness measurements, and X-ray diffraction. The effect of plasma power on the sample temperature, electron temperature, and plasma density was studied using Langmuir double probe. The measured surface hardness value of the compound layer is 2190 HV 0.1 for treated sample at plasma power 500 W. The compound thickness continuously increases as the plasma power increases. The highest nitriding rate of 5.88 {mu}m{sup 2}/s was recorded when the input plasma power was adjusted at 550 W. This high nitriding rate of treated titanium samples is ascribed to the high concentration of active nitrogen species in the plasma atmosphere and the formed microcracks near ...
Radio frequency (RF) plasma nitriding using different input plasma processing powers (250-600 W) improves the surface of titanium by forming hard phases of TiN, Ti_2N, and Ti (N) into the surface. The characteristics of the compound layer have been investigated by optical microscopy, microhardness measurements, and X-ray diffraction. The effect of plasma power on the sample temperature, electron temperature, and plasma density was studied using Langmuir double probe. The measured surface hardness value of the compound layer is 2190 HV 0.1 for treated sample at plasma power 500 W. The compound thickness continuously increases as the plasma power increases. The highest nitriding rate of 5.88 #mu#m"2/s was recorded when the input plasma power was adjusted at 550 W. This high nitriding rate of treated titanium samples is ascribed to the high concentration of active nitrogen species in the plasma atmosphere and the formed microcracks near to the ...
The present study treats only the collective risk of ex-utero leukaemia associated with the routine releases of the nuclear industrial installations of the North Cotentin (0.0009 cases over the considered period) the uncertainty on the contribution to the collective risk of the incidents and the accidents of the nuclear installations (notably the drilling of the pipe of release in sea arisen in 1979-1980 and the fire of the waste silo on January 6. 1981, for the reprocessing plant of La Hague has not been considered. Only 45% of the risk are taken into account by the study. Every calculated value remains very inferior to the number of leukemia cases observed (4 cases observed for two expected cases) and to the risk of radioinduced leukemia any merged exposure sources, that is to say 0.84 cases. It appears thus not very probable that the nuclear installations of the North - Cotentin can explain the tendency to the excess of observed leukaemia. The limits of the study become attached for ...
The fertilizer contribution to radio uptake by tomato plants was assessed. Tomato and soil samples from four different plantations were analyzed: two using organic fertilizer and two using phosphate fertilizer. The Ra concentrations in eight of the most used tomato fertilizers were determined. The concentration values ranged from 14 to 221 Bq/kg of Ra-226 and from 25 to 176 Bq/kg of Ra-228. Owing to the low Ra concentration and to the used fertilizer quantities, the fertilizers would not increase significantly the Ra soil concentration. However, the highest soil to plant concentration ratios were found in the plantations using phosphate fertilizers. This outcome pointed out the higher Ra availability in the phosphate fertilizer plantations than in the organic fertilizer plantations, showing a possible positive influence of phosphate fertilizers for the tomato Ra uptake. Due to the phosphate fertilizer used, the dose could increase from 0,05 Sv/year to 0,24 Sv/year. ...
Radio interference and TV interference are being a problem in urban and rural areas. This interference is generated by high voltage transmission lines as well as distribution lines. The radio noise can be produced by polluted or damaged insulators, and by metal parts of the distribution lines. The corona effect on the surface of the dielectric material produces high frequency electromagnetic fields during the ionization and during the recombination period. Fields of different intensity are produced by positive voltage and negative voltage. The insulator flashover (leaking current) also produces electromagnetic fields. A new technique to measure these fields was developed. This technique measures the radiated fields on time domain and on frequency domain. This permits us to characterize the radiated field and thus identify the type of the source. Several measurements were done varying the type of the RF generator, i.e., new ...
Biological control agents can be more effective if their populations are genetically diverse, particularly when the target invasive plant comprises a range of genotypes with different susceptibilities and occurs across various microclimates. We report on the use of an efficient approach to find, in the native range, diverse isolates of a rust fungus for biological control. An outdoor trap garden containing various clones of invasive European blackberry (Rubus fruticosus agg.) collected in Australia, each with a different DNA phenotype, was established in France. Within 4?weeks of establishment, the leaf-rust fungus Phragmidium violaceum was recovered from all clones in the garden. Molecular analyses of eight recovered and purified isolates of the fungus from the garden revealed that they w...
Abstract Objectives- Cyclodextrins are useful solubilizing excipients that have gained currency in the formulator's armamentarium based on their ability to temporarily camouflage undesirable physicochemical properties. In this context cyclodextrins can increase oral bioavailability, stabilize compounds to chemical and enzymatic degradation and can affect permeability through biological membranes under certain circumstances. This latter property is examined herein as a function of the published literature as well as work completed in our laboratories. Key findings- Cyclodextrins can increase the uptake of drugs through biological barriers if the limiting barrier component is the unstirred water layer (UWL) that exists between the membrane and bulk water. This means that cyclodextrins are mo...
In this article we evaluate a US Forest Service plan to mitigate damages from an invasive insect on public, forested land. We develop a dynamic model of infestation and control to explicitly account for biological interactions, baseline conditions, and uncertainty, thus creating a more complete picture of policy impacts than a static cost benefit analysis could provide. We combine the results of the dynamic model with an empirical study of nonmarket forest benefits to create a bioeconomic model of ecosystem management. Estimating the empirical model in a Bayesian framework allows us to treat the economic coefficients of the dynamic model as random variables. We specify distributions for the biological parameters and examine the effects of both biological and economic uncertainty on the pre...
Radiotherapy with high-energy carbon ion beams can be more advantageous compared to photons because of better physical dose distribution and higher biological efficiency in tumour cell sterilization. Despite enhanced normal tissue sparing, damage incurred by normal cells at the beam entrance is unavoidable and may affect the progeny of surviving cells in the form of inheritable cytogenetic alterations. Furthermore, the quality of the beam along the Bragg curve is modified by nuclear fragmentation of projectile and target nuclei in the body. We present an experimental approach based on the use of a polymethylmethacrylate (PMMA) phantom that allows the simultaneous exposure to a particle beam of several biological samples positioned at various depths along the beam path. The device was used to measure the biologicaleffectiveness of a 60 MeV/amu carbon-ion beam at inducing chromosomal aberrations in G{sub ...
The relaxations of the Ti(0001) and Zr(0001) surfaces are studied using the plane-wave-basis pseudopotential method within the local-density approximation. We find that the first interlayer spacings of Ti(0001) and Zr(0001) are contracted with respect to the bulk spacings by 6.8% and 6.1%, respectively. Such large relaxations for the close-packed surfaces of Ti and Zr are in good agreement with recent linear-augmented-plane-wave calculations. In addition, we predict a weak vibrational effect on the surface relaxation of Zr(0001) by considering the free energy in the quasiharmonic approximation. This result can be attributed to a very strong bonding between the first- and second-layer Zr atoms as a consequence of the bond-order endash bond-length correlation. copyright 1997 The American Physical Society.
First-principles density functional theory (DFT) based calculations were performed to study the electronic and cohesive properties of all the intermediate ordered phases appearing in the transformation from bcc-based #beta# to hexagonal ordered #omega# phase in Zr_3Al alloy. Full-potential linear augmented plane wave (FPLAPW) method under the GGA was employed to establish the stability hierarchy and structure-property correlations. Further, effective pair potentials upto the fourth nearest neighbours were extracted, which, subsequently, were used for the thermodynamics analysis of the thermally-induced #beta##->##omega# transformation. The lattice collapse mechanism involving the concept of the onset of a displacement wave where the extent of collapse is viewed as an amplification of the displacement wave was employed for further analysis. (author)
A new semi-submersible floating structure is proposed on which three wind turbine towers are installed. This paper presents a basic characteristic of the wave-induced motion of this semi-submersible floating structure via. numerical computations and 1/150 scaled rigid model experiments in a wave tank. In the numerical computations, nonlinear damping effect due to drag forces modeled by the Morison's formula is considered in the equation of motion, where the linear hydrodynamic forces are obtained from the Green's function model. As a result, the response characteristics around the resonant frequency region were successfully improved. In addition to such basic examination, major results of feasibility studies, including the structural stability for severe wave conditions and the long-term fatigue limit state, are presented for a realistic situation.
We report on a hard X-ray phase imaging microscopy (a phase-difference microscopy) that consists of an objective and a transmission grating. The simple optical system provides a quantitative phase image, and does not need a wave field mostly coherent on the objective. Our method has a spatial resolution almost same as that of the absorption contrast microscope image obtained by removing the grating. We demonstrate how our approach provides a phase image from experimentally obtained images. Our approach is attractive for easily appending a quantitative phase-sensitive mode to normal X-ray microscopes, and has potentially broad applications in biology and material sciences.
Radiation damage is considered to be the major problem that still prevents imaging an individual biological molecule for structural analysis. So far, all known mapping techniques using sufficient short wave-length radiation, be it X-rays or high energy electrons, circumvent this problem by averaging over many molecules. Averaging, however, leaves conformational details uncovered. Even the anticipated use of ultra-short but extremely bright X-ray bursts of a Free Electron Laser shall afford averaging over 10^6 molecules to arrive at atomic resolution. Here we present direct experimental evidence for non-destructive imaging of individual DNA molecules. In fact, we show that DNA withstands coherent low energy electron radiation with deBroglie wavelength in the Angstrom regime despite a vast dose of 10^8 electrons/nm^2 accumulated over more than one hour.
Testing deviation of GR is one of the main goals of the proposed {\\emph{Laser Interferometer Space Antenna}}, a space-based gravitational-wave observatory. For the first time, we consistently compute the generation of gravitational waves from extreme-mass ratio inspirals (stellar compact objects into supermassive black holes) in a well-motivated alternative theory of gravity, that to date remains weakly constrained by double binary pulsar observations. The theory we concentrate on is Chern-Simons (CS) modified gravity, a 4-D, effective theory that is motivated both from string theory and loop-quantum gravity, and which enhances the Einstein-Hilbert action through the addition of a dynamical scalar field and the parity-violating Pontryagin density. We show that although point particles continue to follow geodesics in the modified theory, the background about which they inspiral is a modification to the Kerr metric, which ...
An assessment is made of the biologicaleffects and physical hazards of static and time-varying fields associated with the NMR devices that are being used for clinical imaging and in vivo spectroscopy. A summary is given of the current state of knowledge concerning the mechanisms of interaction and the bioeffects of these fields. Additional topics that are discussed include: (1) physical effects on pacemakers and metallic implants such as aneurysm clips, (2) human health studies related to the effects of exposure to nonionizing electromagnetic radiation, and (3) extant guidelines for limiting exposure of patients and medical personnel to the fields produced by NMR devices. On the basis of information available at the present time, it is concluded that the fields associated with the current generation of NMR devices do not pose a significant health risk in themselves. However, rigorous guidelines must be ...
A mixture of aminoacids was irradiated by a scattered proton beam, its energy varying from 4 to 6.6 MeV, by doses up to 5 x 10"1"1 proton/cm"2 for studying the potentiality of abiogenic synthesis of biologically important compounds in space. It was ascertained that increase in the radiation dose and reduction of proton energy involve increase in effectiveness both of destruction of the initial aminoacid (tryptophan, tyrosine, glycine) and synthesis of the relevant dipeptide. Essential influence of mineral substrate on abiogenic synthesis of natural nucleotides under the action of diverse energy sources was pointed out
A simplified approach has been proposed to model the drying of capillary-porous materials with small geometric parameters for practical purposes. Luikov`s theory of mass and heat transfer for capillary-porous bodies was applied to drying of biological materials and it was shown that the thermo diffusion effect can be neglected if the thermal gradient remains small during the whole period of drying. The resulting simplified equations can then be solved using available mathematical software. The simplified equations were applied to drying of wood and a peanut pod
Experimental investigation data are systematized of free radical states and processes in irradiated proteins. The investigation is performed by the radiospectral methods. Results are discussed in detail of the study of free radicals electronic structure of amino acids, peptides and proteins formed by the action of ionizing radiation. The specificity is stressed of the study of monocrystalls of these compounds by the method of electronic paramagnetic resonance. The nature is also studied of primary centres formed under the effect of radiation on biologically important compounds and their subsequent reactions in solid and liquid solutions. Ion-radical states of different functional groups of the protein molecule are studied. Prospects of the study and the role of anion-radicals in biological processes are discusses.
The effects of various approximations used in performing augmented-plane-wave calculations were studied for elements of the fifth and sixth columns of the Periodic Table, namely V, Nb, Ta, Cr, Mo, and W. Two kinds of approximations have been checked: (i) variation of the number of k points used to iterate to self-consistency, and (ii) approximations for the treatment of the core states. In addition a comparison between relativistic and nonrelativistic calculations is made, and an approximate method of calculating the spin-orbit splitting is given.
The effects of various approximations used in performing augmented-plane-wave calculations were studied for elements of the fifth and sixth columns of the Periodic Table, namely V, Nb, Ta, Cr, Mo, and W. Two kinds of approximations have been checked: (i) variation of the number of k points used to iterate to self-consistency, and (ii) approximations for the treatment of the core states. In addition a comparison between relativistic and nonrelativistic calculations is made, and an approximate method of calculating the spin-orbit splitting is given.
Reflection coefficients of electromagnetic waves in a nonuniform plasma layer with electrons, positive ions and negative ions, covering a metal surface are investigated by using the finite-difference-time-domain method. It is shown that the reflection coefficients are influenced greatly by the density gradient on the layer edge, layer thickness and electron proportion, i.e., the effect of the negative ions. It is also found that low reflection or high attenuation can be reached by properly choosing high electron proportion, thick plasma layer, and smooth density gradient in the low frequency regime, but sharp density gradient in the high frequency regime. (authors)
When polarized electrons traverse a region where the laser light is focused their polarization varies even if their energy and direction of motion are not changed. This effect is due to interference of the incoming electron wave and an electron wave scattered at zero angle. Equations are obtained which determine the variation of the electron-density matrix, and their solutions are given. The change in the electron polarization depends not only on the Compton cross section but on the real part of the forward Compton amplitude as well. It should be taken into account, for example, in simulations of the e{yields}{gamma} conversion for future {gamma}{gamma} colliders. (orig.). 16 refs.
When polarized electrons traverse a region where the laser light is focused their polarization varies even if their energy and direction of motion are not changed. This effect is due to interference of the incoming electron wave and an electron wave scattered at zero angle. Equations are obtained which determine the variation of the electron-density matrix, and their solutions are given. The change in the electron polarization depends not only on the Compton cross section but on the real part of the forward Compton amplitude as well. It should be taken into account, for example, in simulations of the e#->##gamma# conversion for future #gamma##gamma# colliders. (orig.).
Some results on mechanical property study of copper and titanium subjected to impact load and next to neutron irradiation are presented. It was shown that shock wave influence involves a substantial shape change of the stress-strain diagram and of respective mechanical characteristics. Yield- and ultimate strength were substantially increased, as well as hardness with a considerable drop of plasticity. Also a heat stability of copper and titanium specimens was studied after being treated with shock-waves and neutron radiation. Results are given of electron microscope study of titanium structure sfter explosion hardening, which caused decomposition of hydride segregations in titanium and increased dislocation density.
Alternative mechanisms of electron state excitation in diatomic molecules are examined with reference to CN and C2 molecules forming in chemical reactions behind strong shock wave fronts in a CO(CO2)-N2 gas mixture. The temperature range considered is 4000-8000 K. An effective excitation mechanism is proposed which involves rapid vibration-rotation excitation at all electron states and nonradiative transitions between perturbed electron states induced by collisions with the ambient gas particles.
Local-density-approximation calculations of the H-point phonon frequency of molybdenum were carried out using a new superlinearized augmented-plane-wave basis. The calculated frequency is in quite good agreement with experiment. This indicates that the effect of the many-body renormalization of the electronic states near the Fermi energy on this frequency is smaller than previously suggested. The superlinearized basis and its use to circumvent computational difficulties associated with extended semicore states such as the 4p state of molybdenum is described.
Los Alamos National Laboratory (LANL) is a unique facility covering over 43 square miles. The Emergency Management and Response Office (EM&R) is required to respond, provide Incident Command (IC), and coordination for all Laboratory emergencies. This requires IC`s and support staff to respond to the actual scene of the incident. Since the IC is under numerous constraints and stress, the office wanted the capability of locating the EM&R vehicles on an electronic map. An automated vehicle location (AVL) system was required for the additional safety of the emergency response personal. The requirements for the AVL system include total automatic tracking and low cost. After careful consideration, it was determined that the most efficient and cost effective system would be based on packet radio technology as the transmission media. The location is determined by the Department of Defense Global Positioning System (GPS). The system that was ...
Despite high local control rate in Ewing's sarcoma the exact indication of radiation therapy is still controversial as well as the choice of the target volume and the optimal dose of radiation. The importance of the quality of radiotherapy has been stressed in recently published data and has shown a significant impact on long term local control with adequate radiation therapy. The dramatic improvement of precision allowed by the conformal therapy and three dimensional dosimetry allow to expect a decrease of late effects expected for second malignancies. However, late sequelae and radio-induced osteosarcoma still remain the major side effects after radiotherapy. The authors discuss the results of the main trials on Ewing's sarcoma on the choice of dose and target volume. Surgery is still the preferred choice for small tumors if the foreseen outcome is identical. (authors). 28 refs.
During the early 1970s, controversy developed over the possible biologicaleffects of electric fields from new 500-kilovolt and 765-kilovolt transmission lines. This, along with growing interest in advancing transmission voltage into the ultrahigh-voltage range (1000 kilovolts and above), led to the initiation of numerous research projects. Several reviews of this research by scientists in the US and other countries indicate that transmission lines have not been proven to be a health hazard to people or animals. The issue remains controversial, however, because research has confirmed some subtle effects of electric fields, and because it is an inseparable part of the public opposition that often accompanies the siting of high-voltage transmission lines. In addition, there is renewed interest in magnetic fields, including a possible association between such fields and human cancers. 2 figures, 2 tables.
This paper presents a new method of extracting biologic particles from a mixture of particles. The method is based on the pumping effect in a p-shaped ultrasonic actuator, which has a gap between its two vibrating metal plates. An adhesive tape is placed at a proper position in the gap. Due to the pumping effect which is induced by the sound field in the gap, the particles with smaller mass and radius in the mixture can be pumped up to reach the adhesive tape; while the ones with larger mass cannot. Therefore, the particles with smaller mass and radius can be extracted from the mixture. A theoretical model which can well explain the operation principle and experimental phenomena is developed. By the experimental results and the theoretical analyses based on the model, the validity of the m...
Using the Sloan Digital Sky Survey (SDSS) and the FIRST (Faint Images of the Radio Sky at Twenty Centimeters) catalogs, we examined the optical environments around double-lobed radio sources. Previous studies have shown that multi-component radio sources exhibiting some degree of bending between components are likely to be found in galaxy clusters. Often this radio emission is associated with a cD-type galaxy at the center of a cluster. We cross-correlated the SDSS with the FIRST catalog and measured the richness of the cluster environments surrounding both bent and straight multi-component sources. This led to the discovery and classification of a large number of galaxy clusters out to a redshift of z ~ 0.5. We divided our sample into smaller subgroups based on their optical and radio properties. We find that FR I radio sources are more likely to be found in ...
We present results of a study of large-scale neutral hydrogen (HI) gas in nearby radio galaxies. We find that the early-type host galaxies of different types of radio sources (compact, FR-I and FR-II) appear to contain fundamentally different large-scale HI properties: enormous regular rotating disks and rings are present around the host galaxies of a significant fraction of low power compact radio sources, while no large-scale HI is detected in low power, edge-darkened FR-I radio galaxies. Preliminary results of a study of nearby powerful, edge-brightened FR-II radio galaxies show that these systems generally contain significant amounts of large-scale HI, often distributed in tail- or bridge-like structures, indicative of a recent galaxy merger or collision. Our results suggest that different types of radio galaxies may have a different formation history, which ...
This report details the status of the Biological Conversion of Synthesis Gas Project. The following tasks are described as being completed: (1) the test plan, (2) culture development, and (3) the mass transfer/kinetic studies. The bioreactor studies (Task 4) are underway. The continuous stirred tank reactor system for the conversion of H{sub 2}S to elemental sulfur using Chlorobium thiosulfatophilum has been studied for varying light intensities. The system was also modified to include both sulfur recovery and cell recycle using ceramic membranes. Studies were also performed to observe the effects of cell recycle using a polysulfone hollow filter membrane module. Work on Task 5, limiting conditions/scale-up, includes a scale-up study with three different size reactors to establish the optimum operating conditions for hydrogen production from synthesis gas by the biological water-gas shift reaction using the photosynthetic ...
Sodium-dependent high-affinity choline uptake was measured in various regions of the brains of rats irradiated for 45 min with either pulsed or continuous-wave low-level microwaves (2,450 MHz; power density, 1 mW/cm2; average whole-body specific absorption rate, 0.6 W/kg). Pulsed microwave irradiation (2-microseconds pulses, 500 pulses/s) decreased choline uptake in the hippocampus and frontal cortex but had no significant effect on the hypothalamus, striatum, and inferior colliculus. Pretreatment with a narcotic antagonist (naloxone or naltrexone; 1 mg/kg i.p.) blocked the effect of pulsed microwaves on hippocampal choline uptake but did not significantly alter the effect on the frontal cortex. Irradiation with continuous-wave microwaves did not significantly affect choline uptake in the hippocampus, striatum, and hypothalamus but decreased the uptake in the frontal cortex. The ...
This article discussed a project formed to develop innovative seismic imaging technologies. The Kaleidoscope project aims to accelerate the processing of seismic sound waves by several orders of magnitude using advanced computer-based techniques to reveal oil and gas deposits buried deep in the earth in a manner that is both cost-effective and efficient. It is expected that the technology will be used in deep water applications with massive untapped reserves. The seismic technology will be used to locate hydrocarbons and oil reserves buried 20,000 feet beneath the seabed. It is estimated that the Gulf of Mexico contains 56 billion barrels of oil equivalent worth nearly $6 trillion. However, the reserves are difficult to locate due to the interbedded salt bodies in the subsurface. The project is simultaneously working on both hardware and software applications, and are currently writing the first petascale set of seismic imaging applications. ...
In the development of high performance heat transfer surface on a compact heat exchanger, it was clarified that how reattachment point heat transfer and fluid flow are affected by channel width, at the same time, an evaluation of heat transfer performance and an investigation of optimum channel width were carried out. The channel system used in the experiment is as follows; (1) blow-off type with rectangular section channel, (2) span length of 200 mm, (3) wave length (pitch) of 80 mm, and (4) channel length of 12.5 wave length. The channel Reynolds number was set at about 10/sup 4/ which is relatively higher than the current studies. The results of the experiment were summarized as follows. (1) The channel width H has relevance to the phase difference between the fluid flow in cone portion of main stream and wave shape, the flow patterns are divided roughly into three types. These boundaries exist at P/H 3.0 and 1.5 (P: ...
Surface wave tomography method based on analysis of ambient noise is widely used during the last decade. It is assumed that correlated component of noise is composed of surface waves generated by sources distributed over the Earth's surface more or less uniformly. In such a case the cross-correlation function (CCF) at two stations may be considered as the Green's function of surface wave. This function should be symmetric relatively to zero time. However analysis of CCF at the stations located at the East-European Platform shows that as a rule CCF is characterized with a strong asymmetry. Since "purered noise cannot be extracted from seismic records due to superposition of earthquake signals, the method for calculation of CCF includes amplitude normalization for suppression of earthquakes that reduces signals from earthquakes to a noise level. The parts of records containing waves from earthquakes are ...
This thesis is devoted to studies which prepared the construction of an atom Mach-Zehnder interferometer. In such an interferometer, the propagating waves are spatially separated, and the internal state of the atom is not modified. The beam-splitters are diffraction gratings, consisting of standing optical waves near-resonant with an atomic transition. We use the Bloch functions to define the atom wave inside the standing wave grating and thus explain the diffraction process in different cases. We developed a nearly all-analytical model for the propagation of an atom wave inside a Mach-Zehnder interferometer. The contrast of the signal is studied for many cases: phase or amplitude gratings, effects of extra paths, effects of the main mismatches, monochromatic or lightly polychromatic sources. Finally, we discuss three interferometric ...
Due to biologicaleffects of magnetic fields of high voltage transmission lines and induced effects on has pipe line, telecommunication system and interference with sensitive electronic equipment, many effort have been done to reduce transmission lines magnetic fields and several ideas have been introduced. In this paper we review three methods: phase split, shielded and compacted line methods. With aid of a developed software programme these methods are then applied to transmission lines and the results are analyzed.
Medico-biological aspects of Chernobyl accident among suffered children and adult population in Ukraine are exposed. Health condition of children irradiated in postnatal period and born from irradiated parents are described. Results of the most important organs and systems monitoring in different categories of suffered adults and data about non-stochastic and stochastic effects are given. Special attention is given to neuropsychiatric and endocrinological effects, conditions of visceral systems
The physical principals of the interaction between microwaves and matter are considered along with the physical-chemical mechanisms for the absorption of microwave energy by biological tissue. Consideration is given to results of studies of the effects of microwaves on cells, subcellular structures, and membranes. Medical applications of microwaves are discussed along with the development of health standards for the use of microwaves. 122 references.
Late somatic and genetic radiation effects are imperfectly understood, particularly in the human species. However the available information is sufficient to draw reasonably precise risk estimates in man for many types of damage by means of scientifically justifiable procedures and with the necessary caution. This overall absolute risk of major somatic and genetic damage may be set at around 10"-"4/rad of chronic whole-body doses.
Effect of ultrasonic-wave irradiation on the Mn-Zn ferrite powder suspension prepared by solid-state reaction and alcoholic dehydration methods was investigated. Size, distribution, and morphology of the powders prepared at different temperatures were examined, as a function of irradiation time. It was observed that the powders were reduced in size by ultrasonic energy through distinct routes. 8 refs., 7 figs., 1 tab.
Solid state effects are taken into account in an internal conversion coefficients computation by using Wigner-Seitz boundary conditions. Both the bound and free electron wave functions are calculated from an atomic Dirac-Hartree-Fock-Slater self consistent potential. These internal conversion coefficients are compared with those obtained from the usual free atom boundary conditions.
Solid state effects are taken into account in an internal conversion coefficients computation by using Wigner-Seitz boundary conditions. Both the bound and free electron wave functions are calculated from an atomic Dirac-Hartree-Fock-Slater self consistent potential. These internal conversion coefficients are compared with those obtained from the usual free atom boundary conditions. (orig.).
The atomic explosions in Hiroshima and Nagasaki made the name radiation itself become a nightmare. Notwithstanding this, radiation continued to serve the mankind specially in diagnosis of several human diseases and in the treatment of intractable malignancies. With their latest research tools biologists have now shown a significant shift in the earlier paradigm; even the concept that radiation initiates cancer appears to be no longer tenable. On the contrary, selective radiation doses inhibit growth of cancer cells and radiation in combination with many chemotherapeutic drugs, radiosensitizing chemicals and/or hyperthermia, is emerging as a new modality for cancer treatment which offers high therapeutic advantages. In addition, the deleterious effects of radiation can now be strategically counter poised by the use of many drugs and chemicals. This has been possible by the newer insights gained in the mechanism of biological ...
The development of modern techniques for the cooling and the manipulation of atoms in recent years, and the possibility to create Bose-Einstein condensates and degenerate Fermi gases and to load them into regular optical lattices or disordered optical potentials, has evoked new interest for the disorder-induced localization of ultra-cold atoms. This work studies the transport properties of matter waves in disordered optical potentials, which are also known as speckle potentials. The effect of correlated disorder on localization is first studied numerically in the framework of the Anderson model. The relevant transport parameters in the configuration average over many different realizations of the speckle potential are then determined analytically, using self-consistent diagrammatic perturbation techniques. This allows to make predictions for a possible experimental observation of coherent transport phenomena for cold atoms in speckle ...
It is anticipated that early in the next century manned missions into outer space will occur, with a mission to Mars scheduled between 2015 and 2020. However, before such missions can be undertaken, a realistic estimation of the potential risks to the flight crews is required. One of the uncertainties remaining in this risk estimation is that posed by the effects of exposure to the radiation environment of outer space. Although the composition of this environment is fairly well understood, the biologicaleffects arising from exposure to it are not. The reasons for this are three-fold: (1) A small but highly significant component of the radiation spectrum in outer space consists of highly charged, high energy (HZE) particles which are not routinely experienced on earth, and for which there are insufficient data on biologicaleffects; (2) Most studies on the ...
Data from Monte Carlo transport codes are used to model radiobiological effects. We previously reported the Fourier analysis of ionization data generated by simulating a 500-keV proton traversing water. Here, we extend Fourier analysis to energy transfer data of another radiation type, a 14-MeV #alpha#-particle. A radiobiological model based on this frequency-domain analysis views cell as an information processing system . It lends itself naturally to traditional engineering analyses. One engineering principle-the output response of a linear system to random signal-is applied here to explain the fact that there is measurable difference in the magnitude of the biologicaleffectiveness when a given biological system is irradiated with two different radiation types of the same Linear Energy Transfer (LET).
A historical perspective is given of the current paradigm that does not explicitly protect the environment from radiation, but instead, relies on the concept that if dose limits are set to protect humans then the environment is automatically protected as well. We summarize recent international questioning of this paradigm and briefly present three different frameworks for protecting biota that are being considered by the U.S. DOE, the Canadian government and the International Commission on Radiological Protection. We emphasize that an enhanced collaboration is required between what has traditionally been separated disciplines of radiation biology and radiation ecology if we are going to properly address the current environmental radiation problems. We then summarize results generated from an EMSP grant that allowed us to develop a Low Dose Irradiation Facility that specifically addresses effects of low-level, chronic irradiation on multiple ...
For the purposes of energy forests, biological pest control should be interpreted as any method of using natural organisms or their products for the regulation of herbivores, below the economic threshold. The organisms include the energy forest crop species and natural enemies of pest herbivores. Examples are provided of three-trophic-level interactions, including some on willows and poplars. Bottom-up effects may be particularly strong in juvenile Salicaceae, which are used in energy forest production, because plants are growing vigorously, and many herbivores respond positively. Some major pests on willows and poplars appear to have weak top-down regulation, and they may be influenced most by bottom-up effects such as plant resistance through genetic variation, ontogenetic aging and physiological aging. Balancing the bottom-up and top-down forces in energy forests may be difficult in short-rotation crops, but harvesting ...
Purpose - The objective of this study is to examine the effects of pan-frying, boiling and cooking in a microwave on the amount of L-carnitine in meat and to look at its distribution in the surrounding fluid after food processing. Design/methodology/approach - Total carnitine, free carnitine and acylcarnitines were determined in meat samples from beef, pork and poultry (including ostrich) and in a liver sample from beef. The measurements were carried out before and after the specimens were subjected to different heat treatments. A radio-enzymatic assay was used for measurement of L-carnitine. Results are expressed per 100 gram dry matter and per 100 gram wet weight. Findings - Except for pan-frying, virtually no losses of carnitine occurred during the different procedures of heat treatment...
This paper describes an experiment which has been performed with a somewhat different philosophy in its approach as compared to previous work. (a) The trigger threshold energy was increased by more than a factor of ten on previous experiments reducing the dilution effect of many lower energy showers known not to produce tachyons. 1673 shower were recorded. (b) The exposure time was made longer than previous experiments in order to obtain a reasonably large statistical sample at the higher threshold. Observations were made between February 1979 and June 1980, the total live time being 9768 hours. (c) Records of the detector output amplitude for the 480#mu#s lead time were integrated point by point as is sometimes done in radio astronomy, this gives the integrated energy deposition within the detector.
Cellular telephones emit a radiofrequency electromagnetic field, part of which is absorbed in the user's head. Many studies have been conducted to look for their possible health hazard to human, at the experimental, epidemiological or clinical level. After a short recall on dosimetry, the author describes the state-of-the art about harmful and irreversible effects, up to now not confirmed, and about some benign symptoms which look absolutely actual. A causal relationship of the electromagnetic field on these benign symptoms is however not proven; other, studies are running to evaluate their possible long-term consequences. Interferences with cardiac pacemakers can easily be avoided by holding the telephone handset farther than 10 cm. (author)
We investigate opportunistic cooperation between unlicensed secondary users and legacy primary users in a cognitive radio network. Specifically, we consider a model of a cognitive network where a secondary user can cooperatively transmit with the primary user in order to improve the latter's effective transmission rate. In return, the secondary user gets more opportunities for transmitting its own data when the primary user is idle. This kind of interaction between the primary and secondary users is different from the traditional dynamic spectrum access model in which the secondary users try to avoid interfering with the primary users while seeking transmission opportunities on vacant primary channels. In our model, the secondary users need to balance the desire to cooperate more (to create more transmission opportunities) with the need for maintaining sufficient energy levels for their own transmissions. Such a model is applicable in the ...
By the department Radio-ecology of the Laboratory for Radiation Research, in the period 1981 up to 1989 inclusive, the transfer has been studied, from soil to plant, of a number of important activation and fission products, originating in the nuclear-power production in nuclear power plants. The purpose of this study was twofold: on the one side the quantification of this transfer for various agrarian systems and on the other side to find out in how far, after an accidental contamination, certain agriculture activities can influence essentially the transfer and subsequently the radiation burden for the population. Emphasis lay, the last years, in particular upon this second aspect. The results of this study form essential basic data for diffusion models for radioactive materials which, in turn, are important in estimating the effects of measures. (author). 6 refs.; 4 figs.
In this study structural and magnetic character of the expanded austenite phase (gN) layer formed on a medical grade CoCrMo alloy by a low-pressure Radio-Frequency plasma nitriding process was investigated. The formation of the expanded austenite phase is facilitated at a substrate temperature near 400^oC for 1, 2, 4, 6 and 20h under a gas mixture of 60% N2-40% H2. The magnetic state of the gN layers was determined by a surface sensitive technique, magneto-optic Kerr effect (MOKE), and with a scanning probe microscope in magnetic force mode (MFM). Strong evidence for the ferromagnetic nature of the gN-(Co,Cr,Mo) phase is provided by the observation of stripe domain structures and the hysteresis loops. The ferromagnetic state for the gN phase observed here is mainly linked to large lattice ...
Many modern military systems used for communications, command and control, navigation, and surveillance depend on reliable and relatively noise-free transmission of radiowave signals through the earth's ionosphere. Small-scale irregularities in the ionospheric density can cause severe distortion, known as radiowave scintillation, of both the amplitude and phase of these signals. The WBMOD computer program can be used to estimate these effects on a wide range of systems. The objective of this study is to investigate improvements to the WBMOD model based on extensive data sets covering both the equatorial and high-latitude regimes. This report summarizes the work completed during the second year, which include completion of the new models for the equatorial region and initial development of models for the high latitude (auroral and polar cap) region.
Lithium phosphorous oxynitride(Lipon) thin films as a lithium ion conductive electrolyte were prepared by radio frequency reactive sputtering in N2 plasma. The properties of the amorphous Lipon solid electrolyte were investigated as a function of N2 pressure during reactive sputtering. The ionic conductivity and the electrochemical stability of Lipon thin films improved drastically as the N2 pressure decreased. The ionic conductivity closed to 10?6 S cm?1 and obtained a stability window of 1.0?5.0 V with an N2 pressure of 5 mTorr, where the number of nitrogen bonds between the phosphate groups were more than those formed at higher pressure. It was possible to fabricate the Li//LiCoO2 complete thin film battery using this Lipon solid electrolyte, which exhibited excellent discharge characte...
Austenitic stainless steel AISI 304 has been nitrided by radio frequency (rf) plasma containing various nitrogen-hydrogen gas mixtures, in order to study the effect of hydrogen on structure and magnetic properties of the formed compound layer. The thermal temperature has been measured at the vicinity of the samples. The compound layer thus produced has been characterized using, X-ray diffractometer and vibration sample magnetometer. Providing the total pressure of nitrogen and hydrogen is held constant, the addition of hydrogen up to 50% gives new structural phases. The magnetization values of the plasma treated samples are strongly dependent on the percentage of H_2 in the gas phase. An excessive amount of hydrogen (#approx#75%) on the other hand, retards the nitriding process. The surface temperature of the sample and plasma condition is crucial factors for nitriding process.
The authors report on observations of plasma wave turbulence generated during electron beam injections, spacecraft potential variations, and neutral gas emissions of the CHARGE 2 sounding rocket experiment. The payload was flown in a mother/daughter configuration, with the two sub-payloads electrically connected by an insulated, conducting tether. While tethered, the two platforms were separated, drifting apart in a direction perpendicular to both the magnetic field and to the spacecraft velocity, reaching a maximum distance of 426 m at the end of the flight. The mother carried a high-voltage (HV) system (0-460 V), biasing the mother negative relative to the daughter. The operation of the HV bias system simulated the motional emf induced in larger orbiting space structures like the Tethered Satellite System 1 (TSS 1) space shuttle mission scheduled for the spring of 1992. In addition, the mother carried an electron beam accelerator (1 keV, 0-46 mA). The daughter ...
The stages of processes leading to radiation damage are studied, as well as, the direct and indirect mechanics of its production. The radiation effects on nucleic acid and protein macro moleculas are treated. The physical and chemical factors that modify radiosensibility are analysed, in particular the oxygen effects, the sensibilization by analogues of nitrogen bases, post-effects, chemical protection and inherent cell factors. Consideration is given to restoration processes by excision of injured fragments, the bloching of the excision restoration processes, the restoration of lesions caused by ionizing radiations and to the restoration by genetic recombination. Referring to somatic effects of radiation, the early ones and the acute syndrome of radiation are discussed. The difference of radiosensibility observed in mammalian cells and main observable alterations in tissues and organs are commented. ...
The electronic structure and optical properties in tetragonal ceramics PbTiO_3, are studied by using full-potential linearized augmented plane wave method in density functional theory with the generalized gradient approximation by WIEN2K package. The theoretical calculated optical properties and energy loss spectrum yield a static refractive index of 2.59 and a plasmon energy of 22.7eV for the tetragonal phase. The effective electron number at low energy saturates near 22-23eV with the value of 50 for the effective electron number. The results show a indirect band gap of 2.2eV at the I' point in the Brillouin zone. The :calculated band structure and density of states of PbTiO_3 agree with previous experimental and theoretical results.
Molecular cluster predictions for electronic energy levels, wave functions, momentum densities, and Compton profiles of VO and VO_2 are examined within the Hartree-Fock-Slater model. VO_6 clusters are treated in O/subh/, D_4/subh/, and D_2/subh/ symmetry to obtain quantitative relations between distortion parameters and level shifts and splittings. Effects of the crystal environment are taken into account by a potential field. Results for VO are consistent with the augmented plane-wave band calculation of Mattheiss and x-ray emission data; the VO_2 levels are in good agreement with x-ray photoelectron spectroscopy data. A sizable anisotropy is predicted for the Compton profile of VO and VO_2.
Many solutions of General Relativity appear to allow the possibility of time travel. This was initially a fascinating discovery, but geometries of this type violate causality, a basic physical law which is believed to be fundamental. Although string theory is a proposed fundamental theory of quantum gravity, geometries with closed timelike curves have resurfaced as solutions to its low energy equations of motion. In this paper, we will study the class of solutions to low energy effective supergravity theories related to the BMPV black hole and the rotating wave-D1-D5-brane system. Time travel appears to be possible in these geometries. We will attempt to build the causality violating regions and propose that stringy effects prohibit their construction. The proposed chronology protection agent for these geometries mirrors a mechanism string theory employs to resolve a class of naked singularities. (author)
BackgroundThe aim of this double-blind randomized study is to test the efficacy of a radio electric stimulator device using an auricular reflex therapy protocol for stress-related...Full Text Available
Presentation of electromagnetic sources constituted by various radio transmitters contributing to different radio communication services in the environment. Results of a measures campaign to assess the electromagnetic field in the close neighbourhood of various stations. Analysis by frequency domains. (author)
... small water or ice particles by impaction ... flight recording; principally the hydrometeor charge unit ... capability of directing aircraft movements by radio ...
Using the linearized augmented-plane-wave (LAPW) -calculated electron and positron charge densities for YBa_2Cu_3O_7, the Brillouin-zone-reduced electron-positron momentum density is computed and the zone-reduced two-dimensional angular correlation of annihilation radiation (2D ACAR) spectrum is produced. The calculations show that the relative weights of the Fermi-surface discontinuities are substantially altered due to the positron preferentially sampling the Cu-O chain region. In addition, the reduced 2D ACAR spectrum contains large k-dependent wave-function effects. The theoretical zone-reduced 2D ACAR spectrum is compared to the several existing experimental spectra. It is concluded that, at present, positron-annihilation experiments do not provide consistent and clear evidence for the existence and shapes of Fermi surfaces in YBa_2Cu_3O_7.
The Versatile Toroidal Facility (VTF) is a large laboratory plasma machine of 1 meter major radius used to carry out investigations of ionospheric plasma turbulence. Spectral analysis has been performed on plasmas produced by the electron emitters. Interest has focused on the low frequencies below the lower hybrid resonance where ion acoustic and current-convective modes have been observed. Microwaves injected from a 3,000 watt magnetron produce dramatic changes to the low frequency spectrum. First, the parametric decay instability intensifies the ion acoustic modes in the region of plasma heated by the microwaves. Second, the normally dominant current-convective modes are greatly suppressed in the heated region due to the oscillating electric field of the pump wave. When the authors probe beyond the heated region, these two pump waveeffects are no longer observed, presumably because the microwaves are denied access to ...
High-performance heat transfer augmentation methods applicable in the forced convection field of heat exchangers include a method which requires no external drive means, such as the insertion of a turbulence augmentation object into the flow passage and the use of a wave-shaped flow passage, but disturbs the main stream of flow to raise the heat transportation effect thereby to augment heat transfer in the flow passage. The heat transfer characteristics and thermal performance ratio achieved when sinusoidal-shape plates are inserted instead of augmentation objects, such as cylinders, with a high shape-induced resistance were studied. As a result, the relationship between the resistance coefficient, average Nusselt number, heat transfer coefficient, and pitch was clarified. It has been revealed that the use of eddies with a large gap flow and recirculation area should be considered in order to get a higher heat transfer coefficient and a higher ...
A case report of falsely elevated serum hormone values measured by radio-immunoassay (RIA) is described. The radio-immunoassays concerned have a first antibody raised in rabbits and mostly a separation technique based on a second antibody-solid phase system. The presence of heterophyle (anti-rabbit) antibodies in patients' serum is proved.
The prediction of faults on high voltage transmission lines requires the detection of incipient faults, which is implemented by detection of the radio noise due to contaminated insulators, insulation deterioration, and improver connections. It is shown that the radio noise due to incipient faults is separable and identifiable from normal transmission line radio noise, hence faults can be predicted.
This report is a summary of the contribution of nitrogen and phosphorus in the eutrophication process of inland and coastal waters. Special attention was paid to the mechanisms of these nutrients in regulating biological processes and to the methods available in estimating their effects in the eutrophication of water bodies. The report includes five chapters which are entitled: Introduction, which is a general background to the subject with special attention to the requirements of the Finnish Water Act. Phosphorus and nitrogen as factors regulating biological processes. The topics included are: definition of eutrophication, forms of phosphorus and nitrogen and their sources to inland and coastal waters, effects of these nutrients as growth factors of phytoplankton and macrophytes and consequences of eutrophication. Estimation of the effects of phosphorus and nitrogen. The topics ...
The aim of this paper is to provide a general view of wave energy resource assessment. First, a review of the origin of waves and the transformation they undergo as they propagate towards the coast through waters of decreasing depth is presented. Following this, the wave and wave-energy parameters and the statistics required for resource characterization are described. The various types of wave data and their usefulness for the present purposes are summarised. A common methodology for assessment of the wave energy resource is developed. Finally, a general description of the global open ocean resource is presented.
Effect of water injection/draining on elastic waves penetrating through cracks is examined by measuring elastic waves before, during, and after the injection/draining of water into/from cracks in presence in granite. Two blocks of rock, with their crack-containing surfaces in contact with each other, are placed in a vessel, and water injection/draining is done through a hole on a vessel bottom side so that water will penetrate into the cracks. When the blocks are dry, there is almost no contact between the cracks, and so no crack penetrating waves are observed. Crack penetrating waves are produced when water is injected, and the position of the receiver sensing the penetrating waves changes as the water level rises. When the water level is lowered from the high water level, the waveform changes again as the level changes. The change in waveform is not so ...
Hexane extract of licorice (Glycyrrhiza glabra L.) roots was obtained and investigated. Hydrocarbons, sterol ethers, triacylglycerides, free fatty acids, and free sterols were identified. The extract contains 70% neutral and 30% polar lipids. It is established that the lipid fraction of licorice roots is more effective than the analogous fraction of rosehip oil in stimulating the reparative regeneration of skin. In addition, this fraction also exhibits pronounced antiinflammatory and antiulcer effects, while being virtually nontoxic. Based on these results, the lipid fraction of licorice roots can be recommended as a parent substance for creating effective preparations in various medicinal forms.
With the increasing use of high voltage alternating current (HVAC) transmission lines there is a growing concern among the public about possible human health effects resulting from exposure to the electric fields associated with these lines. While there is no definitive evidence of such effects, mounting public fear and activism over hypothesized health risks is already causing delays in the licensing and constuction of major power transmission facilities, and is encouraging the formation of regulatory policy. This paper briefly reviews the concerns, biologicaleffects data and standards for HVAC transmission lines.
The evaluation of biological markers is recognized as necessary to the future of toxicology, epidemiology, and quantitative risk assessment. For biological markers to become widely accepted, their validity...Full Text Available
A number of biological agents are available or being investigated for the treatment of asthma and rhinitis. The safety profiles of these biologic agents, which may modify allergic and immunological...Full Text Available
Muonic-atom energy levels and wave functions are calculated. The results are corrected for nearly all important static effects, including finite nuclear size as produced by a user-specified nuclear charge distribution. Fourth-order Runge-Kutta integration of the radial Dirac equations, with the secant method determining the eigenvalues. Corrections are either included as potentials in the Dirac equations or computed as first-order perturbations. The code assumes spherical symmetry, so that effects of nuclear deformation may be treated only as static first-order perturbations. Dynamic muon-electron and muon-nuclear effects are neglected (the latter are calculated by RURP). (Auth.).
The subband structure and optical properties of a cylindrical quantum well wire under intense non-resonant laser field are investigated by taking into account the correct dressing effect for the confinement potential. The energy levels and wave functions are calculated within the effective mass- approximation using a finite element method. It is found that the absorption coefficient and the saturation intensity are strongly affected by the laser amplitude and frequency as well as by the incident light polarization. As a key result, a large anisotropy in the linear and nonlinear optical absorptions for very intense laser field is predicted. These effects can be useful for the design of polarization sensitive devices.
A nonneutral /sup 7/Li/sup +/ ion plasma is described in which ion Langmuir waves are observed for the first time. The properties of these waves near the Brillouin density limit are investigated.
A broad-based, multidisciplinary research program is being conducted to study biologicaleffects of electric and magnetic fields from high-voltage transmission lines. Assistance and technical support for this program are reported. (DLC)
The electrochemical oxidation as a method to destroy drug residues like Aspirin {sup trademark}, tetracycline or gentamicin in water was investigated with C-Anode (modified by manganese oxides) and Pt Anode. The mechanism of Aspirin {sup trademark} and tetracycline oxidation and the influence of the biocide effect was observed using GC-MS and three different microbiological tests. In general the biological availability increases with progressive oxidation of the antibiotics. (orig.)
A method for the chemical modification of the initial structure of humic acids by acylation with indole-3-acetic acid chloride was developed to increase the biological activity of preparations based on peat and lignite humic acids. The plant growth stimulating effect and the antibacterial activity of the synthesized humic preparations were studied.
This apper discusses whether health risks are associated with exposure to electromagnetic fields that exist beneath high-voltage transmission lines. This is a question receiving increasing attention as the electric utility industry prepares to supply its customers with increased amounts of electric power. 26 refs.
Cell death after irradiation occurs by apoptosis in certain cell populations in tissues. The phenomenon also occurs after high linear energy transfer (LET) irradiation, and the relative biologicaleffectiveness (RBE) is 3 to 4 (with respect to low-LET radiation and apoptosis in intestinal crypts) for neutrons with energies of 14 MeV and up to 600 MeV. It is thought that p53 plays a role in the phenomenon, as radiation-induced apoptosis is not observed in p53-null animals. (orig.).
The stable hydrogen (δ2H) and oxygen (δ18O) isotope ratios of organic and inorganic materials record biological and physical processes through the effects of substrate...Full Text Available
The seminal work of Stern and his coauthors on integrated control has had a profound and long-lasting effect on the development of IPM programs in western orchard systems. Management systems based solely on pesticides have proven to be unstable, and the success of IPM systems in western orchards has been driven by conservation of natural enemies to control secondary pests, combined with pesticides and mating disruption to suppress the key lepidopteran pests. However, the legislatively mandated changes in pesticide use patterns prompted by the Food Quality Protection Act of 1996 have resulted in an increased instability of pest populations in orchards because of natural enemy destruction. The management system changes have made it necessary to focus efforts on enhancing biological control n...
Dinarmus basalis Rondani (Hymenoptera: Pteromalidae), an ectoparasitoid of bruchid pests of stored cowpeas (Vigna unguiculata), is a potential biological control agent. We investigated whether grain protectants from Hyptis spicigera and H. suaveolens (Lamiaceae) disturb parasitism and post-embryonic growth of the parasitoid. When cowpeas containing bruchid larvae were treated before being placed in the presence of D. basalis females, the rate of parasitism decreased on average up to 24% and 47% in the presence of, respectively, leaf dry powder and essential oils from both plant species. The estimated larval mortality was higher on treated (9.55 to 28.6%) than on non-treated parasitized hosts (2.8%), depending on the plant species and the plant extract tested. Additional larval mortality wa...
The research project had the aim to develop a standard for measuring individual, inner stresses from polycyclic aromatic hydrocarbons (PAHs) at work. The employed method was by characterizing PAHs and metabolites of PAHs to be identified in urine with a view to developing a biological monitoring of professionally exposured persons. Using a number of PAHs relevant to work, the following questions were studied in cell culture systems and different animal-experimental models: Which metabolites are formed from the PAHs used in cell culture systems and the different animal-experimental models, and what are their ratios in percent? What percentage of a PAH is excreted by experimental animals in their urine and faeces on the first, second, and third day following different forms of application? What is the scale of the individual range of variation of PAH mass excretion? Are these results transferable to man? (orig.).
Papers are presented on the modeling, dispersion, formation, transformation, monitoring and biologicaleffects of atmospheric pollution. Specific topics include a prognostic mesoscale model for pollutant transport and diffusion, commuter exposure modeling, a Gaussian plume model for an urban area, carbon monoxide dispersion in an urbanized area, wind-tunnel modeling of flue gas dispersion, the regional-scale transport of fine aerosol components in eastern North America, and a Markov process for the generation of hourly average wind vectors. Attention is also given to photochemical aerosol formation in multicomponent systems, heterogeneous nitrogen oxide-particulate reactions, the generation and measurement of primary soot aerosols of size between 50 and 400 A, inertial particle size classification techniques, the design of air quality monitoring networks, visibilities in polluted and unpolluted areas, and monitoring air quality according to an ...
The electronic structure of the C15, or cubic-Laves-phase material, UAl/sub 2/ has been calculated using the linearized relativistic augmented-plane-wave method. The anomalous behavior of the electrical resistivity, specific heat, and magnetic susceptibility can be explained by the fine structure of the density of states near the Fermi energy alone, without the necessity of the introduction of drastic spin fluctuations or many-body effects.
The objectives of this project are to detect and characterize fractures in a naturally fractured tight gas reservoir, using surface seismic methods, borehole imaging logs, and in-situ stress field data. Further, the project aims to evaluate the various seismic methods as to their effectiveness in characterizing the fractures, and to formulate the optimum employment of the seismic methods as regards fracture characterization.
We discuss the use of active control to reduce mirror position fluctuations at the quantum level. We have shown in a recent experiment that it is possible to reduce the thermal noise of a mirror by measuring and controlling its motion with an optomechanical sensor based on a high-finesse optical cavity. This approach can be extended to lock the mirror motion at the quantum level, and to suppress the quantum effects of radiation pressure in interferometric measurements such as gravitational-wave detectors. The sensitivity improvement is furthermore independent of losses in the interferometer.
It is shown that account of nuclear effects in nucleon channel is of principle importance when analyzing hadron-nucleon process at high energies. This enables to make correct conclusions both about the contribution of multiquark systems - fluctons - to nuclear wave function and about quark distribution in them. Analysis of these distributions shows that color degrees of freedom in flucton are partially unfrozen and flucton contains with high probability one or two quarks.
Isospin-breaking effects in the baryonic sector are studied in the framework of a medium-modified Skyrme model. The neutron-proton mass difference in infinite, asymmetric nuclear matter is discussed. In order to describe the influence of the nuclear environment on the skyrmions, we include energy-dependent charged and neutral pion optical potentials in the s- and p-wave channels. The present approach predicts that the neutron-proton mass difference is mainly dictated by its strong part and that it strongly decreases in neutron matter. (orig.)
We construct the Generalized Monodromy matrix $\\mathcal{\\hat{M}}(\\omega)$ of two dimensional string effective action by introducing the T-duality group properties.The integrability conditions with general solutions depending on spectral parameter are given. This construction is investigated for the exactly solvable Wess, Zumino, Novikov and Witten (WZNW) model in pp-wave Limit when B=0.
Recent experiments have explored the use of a free-electron laser (FEL) as a buncher for a microwave two-beam accelerator, and the subsequent driving of a standing-wave rf output cavity. Here the authors present a deeper analysis of the longitudinal dynamics of the electron bunches as they are transported from the end of the FEL and through the output cavity. In particular, the authors examine the effect of the transport region and cavity aperture to filter the bunched portion of the beam.
A two-dimensional (2D) lattice model with anisotropic resonant microstructures is found to provide an anisotropic band gap structure. A 2D continuum with anisotropic effective mass density is introduced to represent this lattice system. Two methods are proposed to derive the equivalent continuum. In the first method, the effective mass density of the equivalent continuum is obtained by matching the dispersion relations for harmonic waves propagating in the principal directions. The second approach employs an approximate estimation of the effective mass density by volume-averaging an effective mass that represents the resonant microstructure. For both equivalent continuum models, the effective mass density is frequency-dependent and may become negative in certain frequency ranges. Subsequen...
We report de Haas--van Alphen measurements of the Fermi surface of lutetium at temperatures down to 0.3 K and in fields up to 150 kG in the (1010) and (1120) planes. Lutetium, having a filled 4f shell, serves as a nonmagnetic prototype of the structurally similar (hcp), trivalent, heavy rare-earth elements from Gd to Tm. The fact that no complete frequency branches were observed indicates that there are no closed pieces of the Fermi surface. We observed all but one orbit predicted by relativistic augmented-plane-wave calculations of Keeton and Loucks and by recent spin-orbit--linearized-augmented-plane-wave calculations of Tibbetts and Harmon. The data support a geometry similar to that of yttrium, and in good qualitative agreement with energy-band theory.
Studies technological safety of installing a water spray pressure vessel between electrostatic dedusters and coal sludge ducts. These sprays are in use elsewhere for steam generator ash removal. Dust ignition and explosion tests were carried out to examine flame and pressure wave propagation through the vessel into ducts. Water jet diameter, amount of water sprayed and coal dust removed were varied. Pressure waves exceeded 250 Pa. Test results show the vessel to be suitable for installation in briquetting plants due to its flame and explosion barrier effect and extermination of smoldering dust fires. The only disadvantage of the vessel is seen as its water and electric power consumption; about 8/sup 3//h of water and 1.5 kW/h of power per vessel serving dedusters of a 2,200 m/sup 2/ rotary brown coal dryer.
The authors study technological safety of installing a water spray pressure vessel between electrostatic deduster and coal sludge ducts. These sprays are in use elsewhere for steam generator ash removal. Dust ignition and explosion tests were carried out to examine flame and pressure wave propagation through the vessel into ducts. Water jet diameter, amount of water sprayed and coal dust removed were varied. Pressure waves exceeded 250 Pa. Test results show the vessel to be suitable for installation in briquetting plants due to its flame and explosion barrier effect and extermination of smoldering dust fires. The only disadvantage of the vessel is seen as its water and electric power consumption: about 8 m/sup 3//h of water and 1.5 kW/h of power per vessel serving dedusters of a 2,200 m/sup 2/ rotary brown coal dryer. (MOS).
Electron collisional data are required for population kinetics modeling and spectral predictions of highly ionized ions in high-temperature plasmas. Nickel-like ions are especially interesting for their potential use in soft X-ray laser schemes pumped by electron collisional excitation and recombination. For highly stripped ions of moderate to high Z, relativistic effects begin to play a role in the atomic-physics calculations. A relativistic multiconfigurational distored-wave model has been used for the calculation of electron excitation cross sections and rate coefficients between the 3s2 3p6 3d10 Ni-like Gd ground state and the singly excited states with an N-shell electron.
Effect of a planar texture quality and its thickness on lasing spectrums and thresholds in dye-doped cholesteric liquid crystal (CLC) of steroid type is explored. Transition from the qualitative planar texture to the poor texture quality is accompanied by change of characteristic mode structures and by shift of barycentre in the long-wave side and the considerable growth of the lasing threshold. It is found that in the CLC texture created by substrates with perpendicular directions of orientation the stable single-mode lasing takes place. The nature of oscillated modes in such texture is caused by phase jump. The gained results show that in steroid CLC, unlike induced one, lasing spectrums is possible to feature with the coupled wave model. Key words: steroidal cholesteric liquid crystal, distributed feedback lasing, oscillation thresholds, phase defect of periodical structure, transmission and lasing spectra
Maldives comprise some of the most characteristic and significant atoll systems, but the meiobenthic assemblages of these islands are still largely unknown. A study on meiofauna was conducted on three Maldivian sandy back-reef platforms differently exposed to stronger westerly monsoons. Clear high energy effects of the waves causing currents and erosions were observed at the completely exposed and isolated offshore reef of Thoddoo Island. Wave energy of medium intensity was confirmed at Rasdhoo by depositional structures (finolhu), while a medium to low energy level was recorded at Gulhi on the basis of the presence of a low sandy bar. The meiofaunal assemblage counted 17 major taxa. Copepods and nematodes were dominant, followed by platyhelminthes and polychaetes. The nematode assemblage ...
An investigation was made of the accumulation of laser damage to transparent polymers irradiated with nanosecond pulses from neodymium and ruby lasers. The damage was investigated by the method of scattering and luminescence in the visible and near ultraviolet parts of the spectrum. It was established that there were two stages in laser damage by repeated irradiation with pulses of intensity below the single-shot damage threshold. An absorbing defect evolved during the first stage in such a way as to create a thermal instability in the surrounding matrix. During the second stage this thermal instability caused spatial growth of laser damage because of propagation of an ionization-inducing absorption wave with a front traveling at the rate governed by the electron component of the thermal conductivity.
We report first-principles frozen-phonon calculations for the determination of the force-free geometry and the dynamical matrix of the five Raman-active A_1_g modes in YBa_2Cu_3O_7. To establish the shape of the phonon potentials atomic forces are calculated within the linearized-augmented-plane-wave method. Two different schemes emdash the local-density approximation (LDA) and a generalized gradient approximation (GGA)emdash are employed for the treatment of electronic exchange and correlation effects. We find that in the case of LDA the resulting phonon frequencies show a deviation from experimental values of approximately -10%. Invoking GGA the frequency values are significantly improved and also the eigenvectors are in very good agreement with experimental findings. copyright 1997 The American Physical Society.
Cavity ringdown spectroscopy (CRDS) with continuous-wave (cw) laser excitation has added high frequency resolution to the ability of CRDS being used for the absolute quantification of trace-level species present in many chemical processes. Cavity dithering technique has easily resolved the problem of resonant coupling of a cw laser light into a high-finesse cavity. The present study addresses the potential uncertainty involved in such cw-CRDS techniques incorporating the cavity mirror motion, i.e., the doppler frequency shift of a probe light inside the cavity. In the high-resolution spectroscopic work of megahertz-accuracy, even the influence of intracavity doppler effect may become significant.
The dynamics of state of the crystallite-containing magma is studied within the framework of the gas-dynamic model of bubble cavitation. The effect of crystallites on flow evolution is considered for two cases: where the crystallites are cavitation nuclei (homogeneous-heterogeneous nucleation model) and where large clusters of crystallites are formed in the magma in the period between eruptions. In the first case, decompression jumps are demonstrated to arise as early as in the wave precursor; the intensity of these jumps turns out to be sufficient to form a series of discrete zones of nucleation ahead of the front of the main decompression wave. Results of experimental modeling of an explosive eruption with ejection of crystallite clusters (magmatic ?bombs??) suggest that a cocurrent flow...
The Gamow-Teller #beta#-transition from the ground state 2"- of "8"8Rb to the 3"- level at 2.734 MeV of "8"8Sr is studied. The nuclear matrix element and the log ft value are calculated using complete nuclear wave functions for the initial and final states. It is shown that, contrary to the normal assumption, the component of the final state does give a very important contribution to due to the presence of strong cancellation effects. Although our calculations favour a wave function for the 3"- level "8"8Sr where neutron 1h-1p configurations are not included, there are still some facts which make that our results cannot be taken as conclusive. (orig.).
A theoretical study of electron and positron band structures of zinc-blende AlN and InN and their alloy Al_0_._5In_0_._5N is presented using the first-principles full-potential linearized augmented plane-wave method. Equilibrium lattices constants are determined from the total-energy minimization method. The results are compared with previous calculations and with experimental measurement. Electron and positron charge densities are computed as function of position in the unit cell. Detailed plots of distributions are along the direction. The ionicity factors are calculated by means of three different approaches. The calculated results of the positron charge density reflect the high insight for the annihilation effect.
In these lecture notes we derive a generic holographic string theory realization of a p-wave superconductor and superfluid. For this purpose we also review basic D-brane physics, gauge/gravity methods at finite temperature, key concepts of superconductivity and recent progress in distinct realizations of holographic superconductors and superfluids. Then we focus on a D3/D7-brane construction yielding a superconducting or superfluid vector-condensate. The corresponding gauge theory is 3+1-dimensional N=2 supersymmetric Yang-Mills theory with SU(N) color and SU(2) flavor symmetry. It shows a second order phase transition to a phase in which a U(1) subgroup of the SU(2) symmetry is spontaneously broken and typical superconductivity signatures emerge, such as a conductivity (pseudo-)gap and the Meissner-Ochsenfeld effect. Condensates of this nature are comparable to those recently found experimentally in p-wave superconductors ...
The electronic structures of BaSnO_3, BaSbO_3, and BaPbO_3, calculated using an extended general-potential linearized augmented-plane-wave method, are reported. The electronic structures of BaSnO_3 and its 6s analog BaPbO_3 are found to be very different, explaining the absence of superconductivity in the Ba(Sn,Sb)O_3 system. These differences are explained by a combination of the relativistic lowering of the 6s states and ion-size effects. Muffin-tin-approximation augmented-plane-wave calculations for BaSnO_3 are also reported and the utility of the muffin-tin approximation for this and similar materials is discussed in terms of the differences between the two sets of calculations.
The concept of the 'white-light cavity' has recently generated considerable research interest in the context of gravitational wave detection. Cavity designs are proposed using negative (or anomalous) dispersion in an intracavity medium to make the cavity resonate over a large range of frequencies and still maintain a high cavity build-up. This paper presents the first experimental attempt and demonstration of white-light effect in a meter long ring cavity using an intracavity atomic medium. The medium's negative dispersion is caused by bi-frequency Raman gain in an atomic vapor cell. Although the white light condition was not perfectly achieved and improvements in experimental control are still desirable, significantly broad cavity response over bandwidth greater than 20 MHz has been observed. These devices will have potential applications in new generation laser interferometer gravitational wave detectors.
In this Ph.D. thesis a model for graphene in presence of quantized electromagnetic interactions is introduced. The zero and low temperature properties of the model are studied using rigorous renormalization group methods and lattice Ward identities. In particular, it is shown that, at all orders in renormalized perturbation theory, the Schwinger functions and the response functions decay with interaction dependent anomalous exponents. Regarding the 2-point Schwinger function, the wave function renormalization diverges in the infrared limit, while the effective Fermi velocity flows to the speed of light. Concerning the response functions, those associated to a Kekul\\'e distortion of the honeycomb lattice and to a charge density wave instability are enhanced by the electromagnetic electron-electron interactions (their scaling in real space is depressed), while the lowest order correction to the scaling exponent of the ...
The annual report surveys the work of the Tata Institute of Fundamental Research (TIFR), Bombay, during the fiscal year 1988-89. Most of the research activities are organised and carried out in two schools of the Institute, namely, the School of Mathematics and the School of Physics. In the School of Mathematics, active research is carried out in almost every branch of pure mathematics. The School of Physics is engaged in research activities of both theoretical and experimental nature in high energy physics, astrophysics, cosmic rays, space physics, astronomy, nuclear and atomic physics, condensed matter physics, molecular biology, computer science and communication and microwave engineering. TIFR has a Basic Dental Research Unit which carries out intervention studies on oral cancer and precancerous lesions. Its Homi Bhabha Centre for Science Education (HBCSE) carries out programmes for improvement of science education at all levels in the country. TIFR outstation ...
Optogenetics, the ability to use light to activate and silence specific neuron types within neural networks in vivo and in vitro, is revolutionizing neuroscientists' capacity to understand how defined neural circuit elements contribute to normal and pathological brain functions. Typically, awake behaving experiments are conducted by inserting an optical fiber into the brain, tethered to a remote laser, or by utilizing an implanted light-emitting diode (LED), tethered to a remote power source. A fully wireless system would enable chronic or longitudinal experiments where long duration tethering is impractical, and would also support high-throughput experimentation. However, the high power requirements of light sources (LEDs, lasers), especially in the context of the extended illumination periods often desired in experiments, precludes battery-powered approaches from being widely applicable. We have developed a headborne device weighing 2 g capable of wirelessly receiving power using a ...
2009 has been an extraordinary year for gamma-ray pulsar astronomy and 2010 promises to be equally good. Not only have we registered an extraordinary increase in the number of pulsars detected in gamma rays, but we have also witnessed the birth of new sub-families: first of all, the radio-quiet gamma pulsars and later an ever growing number of millisecond pulsars, a real surprise. We started with a sample of 7 gamma-ray emitting neutron stars (6 radio pulsars and Geminga) and now the Fermi-LAT harvest encompasses 24 "Geminga-like" new gamma-ray pulsars, a dozen millisecond pulsars and about thirty radio pulsars. Moreover, radio searches targeted to LAT unidentified sources yielded 18 new radio millisecond pulsars, several of which have been already detected also in gamma rays. Thus, currently the family of gamma-ray emitting neutron stars seems to be evenly divided between classical ...
In May 1985, a National Pollutant Discharge Elimination System permit was issued for the Oak Ridge Y-12 Plant, a nuclear weapons components production facility located in Oak Ridge, Tennessee, and operated by Martin Marietta Energy Systems, Inc., for the US Department of Energy. As a condition of the permit, a Biological Monitoring and Abatement Program (BMAP) was developed to demonstrate that the effluent limitations established for the Oak Ridge Y-12 Plant protect the classified uses of the receiving stream (East Fork Poplar Creek), in particular, the growth and propagation of fish and aquatic life, as designated by the Tennessee Department of Health and Environment. A second purpose for the BMAP is to document the ecological effects resulting from implementation of a water pollution control program that will include construction of nine new wastewater treatment facilities over the next 4 years. Because of the complex nature of the effluent ...
Gas-insulated systems employing SF/sub 6/ are utilized in a variety of applications in power delivery systems. Because electric arcs, sparks or corona can decompose SF/sub 6/ into by-products having chemical properties different from SF/sub 6/, environmental concerns arise regarding inadvertent human exposures to electrically-decomposed SF/sub 6/. Biological assays in our laboratory using mammalian cell culture systems have revealed that SF/sub 6/, spark-decomposed under specific experimental conditions, can produce cell death. Chemical analysis of spark-decomposed SF/sub 6/ has identified the major decomposition pathways and by-products. Biological testing of individual by-products or by-product mixtures has indicated that these major decomposition products may not account for the majority of the cell killing effects seen in our assays. Further experiments have suggested that S/sub 2/F/sub 10/ may be produced and ...
The research project had the aim to develop a standard for measuring individual, inner stresses from polycyclic aromatic hydrocarbons (PAHs) at work. The employed method was by characterizing PAHs and metabolites of PAHs to be identified in urine with a view to developing a biological monitoring of professionally exposured persons. Using a number of PAHs relevant to work, the following questions were studied in cell culture systems and different animal-experimental models: Which metabolites are formed from the PAHs used in cell culture systems and the different animal-experimental models, and what are their ratios in percent What percentage of a PAH is excreted by experimental animals in their urine and faeces on the first, second, and third day following different forms of application What is the scale of the individual range of variation of PAH mass excretion Are these results transferable to man (orig.).
Large-scale field tracer experiments have been conducted on Ulchin and Wolsung nuclear sites for the purpose of validating FADAS and of analyzing the environmental characteristics around the nuclear site. The most influential factor in atmospheric dispersion is the meteorological condition. During the experiment, meteorological data were measured on the release point and the selected positions among sampling points. Once radioactive materials are released to the atmosphere, members of public may be exposed through the environmental media such as air, soil and foods. Therefore, to protect the public, adequate countermeasures should be taken at due time for those exposure pathways. Both processes of justification and optimization are applied to a countermeasure simultaneously for decision-making. The work scope of biological research for the radiation protection had contained the search of biological microanalytic methods for the assessment of ...
This study investigated the effectiveness of dealing with biological waste by composting. In particular, it examined the feasibility of recovering excess thermal energy produced in the process of composting biological waste in terms of mass and energy transport parameters required in the aerated compost bed. An experiment was performed in which a 100 dm{sup 3} adiabatic, leak-tight reactor equipped with a controlled aeration system was constructed to study the temperature and pressure distribution in the bed. Sensors were used to determine the amount and humidity of emitted gases under variable external physical conditions. The perforated bottom of the reactor allowed for bed aeration. As such, the humidity and heat were transported upwards, forced by the air pumped in and by natural convection. In terms of pressure distribution inside the composted and aerated bed, the study results showed that there were considerable ...
Ultra High Vacuum (UHV) test setup for electron gun testing has been developed. The development of next generation light sources and accelerators require development of klystron as a radio frequency power source, and in turn electron gun. This UHV electron gun test setup can be used to test the electron guns ranging from high average current, quasi-continuous wave to high peak current, single pulse etc. An electron gun has been designed, fabricated, assembled and tested for insulation up to 80 kV under the programme to develop high power klystron for future accelerators. Further testing includes the electron emission parameters characterization of the cathode, as it determines the development of a reliable and efficient electron gun with high electron emission current and high life time as well. This needs a clean ultra high vacuum to study these parameters particularly at high emission current. The cathode emission current, work function and ...
The Fast Wave Current Drive (FWCD) system at DIII-D has increased its available radio frequency (RF) power capabilities with the addition of two new high power transmitters along with their associated transmission line systems. A Sun Sparc-10 workstation, functioning as the FWCD operator console, is being used to control transmitter operating parameters and transmission line tuning parameters, along with acquiring data and making data available for integration into the DIII-D data acquisition system. Labview, a graphical user interface application, is used to manage and control the above processes. This paper will discuss the three primary branches of the FWCD computer control system: transmitter control, transmission line tuning control, and FWCD data acquisition. The main control program developed uses VXI, GPIB, CAMAC, Serial, and Ethernet protocols to blend the three branches together into one cohesive system. The control of the ...
Two-dimensional calculations are performed to obtain the conversion efficiency of traveling wave direct energy convertor adopted in a conceptual design of field reversed configuration D-"3He fusion reactor ARTEMIS. For fusion-born 14.67MeV protons, the efficiency obtained is very small compared with that from one-dimensional analysis. This is because the effective electric field for deceleration of the proton is smaller due to distortion of potentials near girds used to excite the traveling wave and because some fractions of the incident proton beams are inevitably lost to the grids with high energy. To increase the efficiency, the potentials may have to be increased. It seems from the two-dimensional analysis performed here that the conversion efficiency obtainable is less than about 60% with the maximum potential of about 6MV, while the corresponding values from the one-dimensional analysis are about 80% and 1.5MV, ...
A semirelativistic two-component extended linear augmented plane-wave k#centre dot#p method is described. In order to ensure a high accuracy of the k#centre dot#p method, it is necessary to include into the radial-basis set, which is used for the augmentation of the plane waves, functions that are neither solutions of the Schrodinger equation nor their energy derivatives. The usual scalar relativistic procedure, which is nonlinear in energy, is not applicable to such basis sets. As an alternative, we suggest an approximation to the Foldy-Wouthuysen Hamiltonian that produces an explicitly Hermitean matrix in the augmented plane wave representation. The technique is applied to the calculation of the full dielectric matrix and optical properties of palladium and platinum metals over the photon energy region up to 100 eV. Special attention is paid to the far ultraviolet absorption by the excitations of semicore Pd 4p and Pt 5p ...
We investigate strong nonlinear damping effects which occur during high amplitude oscillations of neutron stars, and the gravitational waves they produce. For this, we use a general relativistic nonlinear hydrodynamics code in conjunction with a fixed spacetime (Cowling approximation) and a polytropic equation of state (EOS). Gravitational waves are estimated using the quadrupole formula. Our main interest are $l=m=2$ $f$-modes subject to the CFS (Chandrasekhar, Friedman, Schutz) instability, but we also investigate axisymmetric and quasi-radial modes. We study various models to determine the influence of rotation rate and EOS. We find that axisymmetric oscillations at high amplitudes are predominantly damped by shock formation, while the non-axisymmetric $f$-modes are mainly damped by wave breaking and, for rapidly rotating models, coupling to non-axisymmetric inertial modes. From the observed ...
The projector augmented-wave (PAW) method was developed by Bloechl as a method to accurately and efficiently calculate the electronic structure of materials within the framework of density-functional theory. It contains the numerical advantages of pseudopotential calculations while retaining the physics of all-electron calculations, including the correct nodal behavior of the valence-electron wave functions and the ability to include upper core states in addition to valence states in the self-consistent iterations. It uses many of the same ideas developed by Vanderbilt in his open-quotes soft pseudopotentialclose quotes formalism and in earlier work by Bloechl in his open-quotes generalized separable potentials,close quotes and has been successfully demonstrated for several interesting materials. We have developed a version of the PAW formalism for general use in structural and dynamical studies of materials. In the present paper, we ...
A Task Group of the International Commission on Radiological Protection (ICRP) has finished a report BiologicalEffects after Prenatal Irradiation (Embryo and Fetus) which has been approved by the Main Commission and Will be Published. Some new important scientific data shall be discussed in this contribution. During the preimplantation period lethality of the mammalian embryo is the dominating radiation effect. However, in mouse strains with genetic predispositions it has been shown that also malformations can be caused. This effect is genetically determined and its mechanisms is different from the induction of malformations during major organogenesis. Radiation exposures during this prenatal period leads ato an increase of genomic instability of cells in the normal appearing fetuses. These radiation effects can be transmitted to the next generation. A renewed analysis of ...
The work scope of 'Biological Research for the Radiation Protection' had contained the research about ornithine decarboxylase and its controlling proteins, thioredoxin, peroxiredoxin, S-adenosymethionine decarboxylase, and glutamate decarboxylase 67KD effect on the cell death triggered ionizing radiation and H_2O_2(toxic agents). In this study, to elucidate the role of these proteins in the ionizing radiation (or H_2O_2)-induced apoptotic cell death, we utilized sensesed (or antisensed) cells, which overexpress (or down-regulate) RNAs associated with these proteins biosynthesis, and investigated the effects of these genes on the cytotoxicity caused by ionizing radiation and H_2O_2(or paraquat). We also investigated whether genisteine(or thiamine) may enhance the cytotoxic efficacy of tumor cells caused by ionizing radiation (may enhance the preventing effect radiation or paraquat-induced damage) because ...
Safety standards for exposure to radiofrequency radiation must be based upon biologic consequences of exposure to such environments. Behavioral-based measures are considered to be the most-sensitive indices of biologicaleffects. Current safety guidelines are based upon average power density and may not be relevant to the high-peak-power, short pulse width microwave radiation produced by newly developed high peak power microwave sources. The effects of exposure to high-peak-power radiation on reflexive responding and motor function in Fischer 344/N rats were assessed by measuring startle and general activity, and disruption of on-going performance of a rotarod task, respectively. The emitter used was the TEMPO repeat pulse axially extracted vircator. Exposure to single pulses resulted in significant startle responses. Exposure to 1 pps for 10 s produced significant alterations in baseline activity and ...
The development of colorimetry and spectroscopy in the nineteenth century is described. An account is given of the application of their techniques to biological chemistry during that period.
The offshore and inshore wave energy resource in Asturias (N Spain) is studied using wave buoy data and a hindcast dataset spanning 44 years (1958-2001). Offshore average wave power and annual wave energy values are found to exceed 30 kW/m and 250 MWh/m, respectively, at 7 of the 11 study sites. This substantial resource is characterised in terms of the sea states involved. Most of the energy is provided by IV quadrant waves with significant wave heights between 2 m and 5 m and energy periods between 11 s and 13 s. After analysing the offshore resource, numerical modelling is used to investigate the inshore wave patterns. A coastal wave model is validated with wave buoy data and applied to three case studies representative of storm, winter and summer conditions. Inshore wave ...
This paper describes nonlinear effect recognized in Vibroseis data. Harmonics is a wave of frequency in integer factors generated in association with basic sweep vibrated by Vibroseis. Harmonics is generated because vibration in the vicinity of seismic source contains nonlinear terms. Seismic exploration using the reflection method often discusses propagation of seismic waves hypothesized as a linear phenomenon. Vibroseis data analysis, however, requires evaluation of the effect of the harmonics on accuracy. Vibroseis investigation measures may be taken by eliminating n-order harmonics by using the phase control method, and generating seismic source sweep in which the phase is shifted by 180/(n-1) each time in order to leave the basic sweep. Methods to increase the sweep length include a method to expel strain to a location outside the range of the subject travel time. Up-sweep (a sweep changing from ...
A survey is presented of the consequences of the irradiation of the population with ionizing radiation. There is an increased incidence of leukemia in irradiated population groups. Among the inhabitants of Hiroshima and Nagasaki maximum death of leukemia was observed in the years 1951 to 1952. The results are summed up of the observation of carcinoma of the breast, lungs and bronchi, bones, and carcinoma of the thyroid. The effect of radiation on experimental animals is described. It was found that the scatter of the dependence of the incidence of various types of cancer on the dose equivalent apparently reflects differences in the biological mechanism of this incidence and that a proportional relationship cannot be expected between the primary damage of cells during irradiation and the actual manifestation of the disease. (E.S.).
Differences in the biological disposition and in the effects of the stable lithium isotopes, Li-6 and Li-7, in animals were characterized. A somewhat higher toxicity was associated with WLiCl compared to XLiCl with NLiCl intermediate. All lithium treatments increased water intake and resulted in weight gain. Peak plasma concentration was slightly high for 6Li than 7LiCl suppressed action potential amplitudes during tetanic stimulation more than NaCl when added to Renger solution bathing ganglia.
In the process of backward Raman amplification (BRA), the leading layers of the seed laser pulse can shadow the rear layers, thus weakening the effective seeding power and affecting parameters of output pulses in BRA. We study this effect numerically and also analytically by approximating the pumped pulse by the ''*-pulse'' manifold of self-similar solutions. We determine how the pumped pulse projection moves within the *-pulse manifold, and describe quantitatively the effective seeding power evolution. Our results extend the quantitative theory of BRA to regimes where the effective seeding power varies substantially during the amplification. These results might be of broader interest, since the basic equations, are general equations for resonant 3-wave interactions.
The present paper investigates the peristaltic transport of a couple stress fluid in an asymmetric channel with the effect of the induced magnetic field. The exact solutions of momentum and the magnetic field equations have been calculated under the assumptions of long wave length and low but finite Reynolds number. The expression for pressure rise has been computed numerically using mathematics software Mathematica. The graphical results have been presented to discuss the physical behavior of various physical parameters of interest. Finally, the trapping phenomena have been discussed for various physical parameters. (orig.)
The present paper investigates the peristaltic transport of a couple stress fluid in an asymmetric channel with the effect of the induced magnetic field. The exact solutions of momentum and the magnetic field equations have been calculated under the assumptions of long wave length and low but finite Reynolds number. The expression for pressure rise has been computed numerically using mathematics software Mathematica. The graphical results have been presented to discuss the physical behavior of various physical parameters of interest. Finally, the trapping phenomena have been discussed for various physical parameters.
Photoluminescence spectra for solutions containing Sm"3"+ isotope ions in heavy and normal water were studied in the wave length #lambda# = 500-700 nm and for absorption spectra and photoluminescence excitation spectra within the range of #lambda# = 260-600 nm. Differences in molar extinction coefficients for "1"4"4Sm"3"+ and "1"5"4Sm"3"+ were established both in the solutions with D_2O and by transition from the solutions with D_2O to the solutions with H_2O. New possible causes of the identified effects are discussed
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We use UV/optical and X-ray observations of 272 radio-quiet Type 1 AGNs and quasars to investigate the CIV Baldwin Effect (BEff). The UV/optical spectra are drawn from the Hubble Space Telescope, International Ultraviolet Explorer and Sloan Digital Sky Survey archives. The X-ray spectra are from the Chandra and XMM-Newton archives. We apply correlation and partial-correlation analyses to the equivalent widths, continuum monochromatic luminosities, and alpha_ox, which characterizes the relative X-ray to UV brightness. The equivalent width of the CIV 1549 emission line is correlated with both alpha_ox and luminosity. We find that by regressing l_UV with EW(CIV) and alpha_ox, we can obtain tighter correlations than by regressing l_UV with only EW(CIV). Both correlation and regression analyses imply that l_UV is not the only factor controlling the changes of EW(CIV); alpha_ox (or, equivalently, the soft X-ray emission) plays a fundamental role in ...
The Green-Chasman lattice, which is the basis for both NSLS storage rings, was conceived with insertion devices in mind. Long, field-free straight sections were provided in the design. The electron optics were chosen so that these sections had zero dispersion and the effects of new magnetic structures placed in these regions would have minimal effect on the emittance of the electron beam. This design concept has been followed by all high-brightness rings which were built subsequent to the NSLS. The X-Ray Ring straight sections also have a very small vertical {beta} function, in addition to the zero dispersion. This was done to optimize the brightness of wiggler sources. There is a further benefit however. The {beta} function determines the beam size and divergence at a particular point in the storage ring lattice. The size is proportional to {radical}{beta} and the divergence is proportional to 1/{radical}{beta}. Thus the electron beam is very ...
In attempting to detect and map out underground facilities, whether they be large-scale hardened deeply-buried targets (HDBT's) or small-scale tunnels for clandestine border or perimeter crossing, seismic imaging using reflections from the tunnel interface has been seen as one of the better ways to both detect and delineate tunnels from the surface. The large seismic impedance contrast at the tunnel/rock boundary should provide a strong, distinguishable seismic response, but in practice, such strong indicators are often lacking. One explanation for the lack of a good seismic reflection at such a strong contrast boundary is that the damage caused by the tunneling itself creates a zone of altered seismic properties that significantly changes the nature of this boundary. This report examines existing geomechanical data that define the extent of an excavation damage zone around underground tunnels, and the potential impact on rock properties such as P-wave and ...
Free-electron laser (FEL) amplifiers have demonstrated high efficiencies and high output power at microwave wavelengths. However, measurements and simulations have indicated that the present level of phase stability for these devices is not sufficient for driving linear accelerators. Fluctuations in the diode voltage, which is needed to accelerate the electron beam, are the largest cause of the shifts in the phase of the output power. Pulse-power technology cannot keep the voltage fluctuations less than 1/4%. However, we have found a scheme that will make the output phase much less sensitive to these fluctuations by exploiting the traveling wave nature of the FEL interaction. In this paper we study the phase stability issue by analyzing the dispersion relation for an axial FEL, in which the rf field is transversely wiggled and the electron trajectories are purely longitudinal. The advantage of using the axial FEL interaction instead of the common transverse FEL ...
To detect the gravitational-wave signal from binary neutron stars and extract information about the equation of state of matter at nuclear density, it is necessary to match the signal with a bank of accurate templates. We have performed the longest (to date) general-relativistic simulations of binary neutron stars with different compactnesses and used them to constrain a tidal extension of the effective-one-body model so that it reproduces the numerical waveforms accurately and essentially up to the merger. The typical errors in the phase over the $\\simeq 22$ gravitational-wave cycles are $\\Delta \\phi\\simeq \\pm 0.24$ rad, thus with relative phase errors $\\Delta \\phi/\\phi \\simeq 0.2%$. We also show that with a single choice of parameters, the effective-one-body approach is able to reproduce all of the numerically-computed phase evolutions, in contrast with what found when adopting a tidally ...
We report on the results of a simultaneous monitoring campaign employing eight Chandra X-ray (0.5-10 keV) and six VLA/EVLA (8.4 GHz) radio observations of NGC 4051 over seven months. Evidence for compact jets is observed in the 8.4 GHz radio band; This builds on mounting evidence that jet production may be prevalent even in radio-quiet Seyferts. Assuming comparatively negligible local diffuse emission in the nucleus, the results also demonstrate an inverse correlation of L_radio proportional to L_X-ray ^(-0.72+/-0.04) . Current research linking the mass of supermassive black holes and stellar-mass black holes in the "low/hard" state to X-ray luminosities and radio luminosities suggest a "fundamental plane of accretion onto black holes" that has a positive correlation of L_radio proportional to L_X-ray^(0.67+/-0.12) . Our simultaneous results differ from this ...
Based on the wave equation theory, the authors use finite difference method to derive wave-field extrapolation formula, by which both wavefield modeling and migration can be made. The migration program VSP MIG that was developed using P-wave equation may be used to migrate both surface seismic data and VSP data. Besides, it may be applied to the migrations of P-wave data and P-SV wave data, in which case the original velocity model should be modified properly. The migrated image times for P-wave and P-SV wave respectively are absolutely equal. The migrations of upgoing P-wave and upgoing P-SV wave which have been separated can offer migrated P-wave section and migrated S-wave section. Thus, one can get more information than from simultaneous migration of ...
Contents include: index for 1970-1980; January 1981 data -- alert periods, daily solar indices, solar flares, solar radio emission, coronal holes, inferred interplanetary magnetic field polarities, mean solar magnetic field, spacecraft observations, December 1980 data -- daily solar-activity centers, sudden ionospheric disturbances, spacecraft observations, solar radio emission, cosmic rays, geomagnetic indices, radio-propagation indices; late data -- solar radio emission November, December 1980, spacecraft observations November 1980, cosmic rays, Huancayo Oct 1980 -- climax, alert, Deep River Nov 1980.
Evolution in Space Radio Telescopes Reveal Youngest Stellar Corpse Gas Clouds in Whirlpool Galaxy Yield Important Clues Supporting Theory on Spiral Arms Starbust-driven Winds...
... of electronic systems (satellite terminals, radio and ... helps organizations investigate the stochastic nature of ... cycle time, maximum queue lengths, and ...
Development of Portable Normobaric Hypoxia and Pulsed Magnetic Field Firmware System for Enhancement of Radio- and Non-specific Resistance in Workers of Environmentally Hazardous Industries
Briefly, 48 MOS microparticle sensors (essentially the same as those flown on .... at the Naval Research Lab to interpret the polarization of the incoming radio .... Adapter Satellite, to be published in Journal of Spacecraft and Rockets, 1994. ...
tions, final noise-power spectral density measurements were made. These measurements of the noise-power spectral density were not the desired phase- noise ...
Measuring gene expression using microarrays is relevant to many areas of biology and medicine, such as follow up of developmental stages and diseases onset, and treatment study. Since there can be tens of thousands of distinct probes on an array, each micro array experiment can accomplish the equivalent number of genetic tests in parallel. Arrays have therefore dramatically accelerated many types of investigations. For example, microarrays can be used to identify stress response genes by comparing gene expression in challenged versus normal cells. In the Molecular and Cellular Biology lab (MCB), the micro array experiments are performed within the Genomic Platform, fully equipped to analyse either the behaviour of bacteria during long space flight, the effect of low dose ionising radiation on the developing organism in mice, or the human individual radiation sensitivity. For the low dose effect, two ...
Abstract: We tested the effects on the early-stage wound healing of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanofiber matrices cultured with hair follicular cells. PHBV only, PHBV/collagen, and PHBV/gelatin at a 7/3 weight ratio were produced by electrospinning, and their in vitro cell culture and in vivo wound healing as biological dressings were examined. In cell attachment and growth on matrices, dermal sheath (DS) cells attached to hydrophilic PHBV/collagen and PHBV/gelatin faster than hydrophobic PHBV at the early incubation stage (up to 6 h). From 6- to 24-h incubation, PHBV/collagen showed the best results in cell culture. Furthermore, PHBV/collagen cocultured for 3-5 days with DS and epithelial outer root sheath (ORS) cells expressed more extracellular materials, such a...
A semi-empirical relation which can be used to determine the total attenuation cross sections of samples containing H, C, N and O in the energy range 145-1332 keV has been derived based on the total attenuation cross sections of several sugars, amino acids and fatty acids. The cross sections have been measured by performing transmission experiments in a narrow beam good geometry set-up by employing a high-resolution hyperpure germanium detector at seven energies of biological importance such as 145.4 keV, 279.2 keV, 514 keV, 661.6 keV, 1115.5 keV, 1173.2 keV and 1332.1 keV. The semi-empirical relation can reproduce the experimental values within 1-2%. The total attenuation cross sections of five elements carbon, aluminium, titanium, copper and zirconium measured in the same experimental set-up at the energies mentioned above have been used in a new matrix method to evaluate the effective atomic numbers and the effective ...
In many parts of the United States, as well as other regions of the world, competing demands for fresh water or water suitable for desalination are outstripping sustainable supplies. In these areas, new water supplies are necessary to sustain economic development and agricultural uses, as well as support expanding populations, particularly in the Southwestern United States. Increasing the supply of water will more than likely come through desalinization of water reservoirs that are not suitable for present use. Surface-deployed seismic and electromagnetic (EM) methods have the potential for addressing these critical issues within large volumes of an aquifer at a lower cost than drilling and sampling. However, for detailed analysis of the water quality, some sampling utilizing boreholes would be required with geophysical methods being employed to extrapolate these sampled results to non-sampled regions of the aquifer. The research in this report addresses using seismic and EM methods in ...
Radioactive waste is generally classified on the basis of how much radiation and the type of radiation it emits as well as the length of time over which it will continue to emit radiation. Many activities dealing with radioactive materials produce nuclear wastes, including civilian nuclear power programs (nuclear Power plant operations and nuclear fuel-cycle activities), defense nuclear programs (nuclear weapons production, naval nuclear reactor programs, and related R and D), and industrial and institutional activities (scientific research, medical operations, and other industrial uses of Radioisotopic sources or Radio chemicals). To minimize the potential adverse health and environment impacts to people and other systems including of animals, plant and etc, during the entire lifetime of the radionuclides involved, nuclear waste must be carefully and properly managed. The scope of nuclear - waste management encompasses generation, processing (treatment and ...
A versatile, high brightness, volume type, low power RF source, capable of producing positive ion beams with intensities as high as 1 mA from gaseous feed materials and microamperes of negative ion beams has been characterized. The source can also be operated as a plasma sputter negative ion source to generate up to 1 mA of a selected species. The performance of the source in the positive and negative volume modes of operation can be greatly enhanced by addition of a removable, water cooled filament assembly in place of the negative sputter probe. For examine, the material utilization efficiencies of gaseous feed species can be more than doubled, total current intensities increased up to 40%, molecular dissociation fractions increased by 20% and minimum operating pressures reduced by a factor of four when operated in the volume mode. These added electrons also favorably effect, as a consequence of lower pressures, the emittance apparently through a reduction of ...
A novel technique is proposed for the growth of an InN film on a GaN/Al2O3(0001) template by radio-frequency plasma-excited molecular beam epitaxy (RF-MBE). The method involves 1) InN growth under an In-rich condition and 2) additional nitrogen radical irradiation after the InN growth under an In-rich condition. Excess In that appeared on the InN surface in the InN growth under an In-rich condition is transformed to InN by the additional nitrogen radical irradiation. The effective V/III ratio is easily controlled by monitoring the intensity in a reflection high-energy electron diffraction (RHEED) pattern. The growth of the InN film by repeating the InN growth under an In-rich condition and the additional nitrogen radical irradiation is also demonstrated. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)
Radiowave scintillation in the presence of ionospheric disturbances has the potential to disrupt numerous transionospheric radio and radar systems. This report describes development of a model characterizing the plasma density irregularities that produce scintillation in the naturally disturbed mid-latitude F layer. The model will be incorporated into Program WBMOD, which includes subroutines for computing both link geometry and scintillation indices, the latter by means of phase screen diffraction theory. Earlier versions of WBMOD, were based on extensive analysis of scintillation data collected in the auroral and equatorial zones in Wideband Satellite Mission. The model described herein is based on similarly extensive analysis of Wideband data from one mid latitude station and of data collected from HiLat satellite at another mid latitude station. The model describes irregularities at an effective height of 350 km that are isotropic across ...
There is increasing use of radiofrequency radiation (RFR) in industry for communications, welding, security, radio, medicine, navigation etc. It has been recognised for some years that RFR may interact with cardiac pacemakers and steps have been taken to prevent this interference. It is less well recognised that other metallic implants may also act as antennas in an RFR field and possibly cause adverse health effects by heating local tissues. There are a large and increasing number of implants having metal components which may be found in RFR workers. These implants include artificial joints, rods and plates used in orthopaedics, rings in heart valves, wires in sutures, bionic ears, subcutaneous infusion systems and (external) transdermal drug delivery patches"1. The physician concerned with job placement of such persons requires information on the likelihood of an implant interacting with RFR so as to impair health. The following outlines the ...
Liquid metal ion sources (LMISs) with Ga as ion species are widely used in focused ion beam (FIB) technology for micromachining and surface treatment on the sub-micron and nano-scale. Key features of a LMIS for investigating mechanical properties and 3D-microfabrication of materials are long life-time, high brightness, stable ion current and a highly effective milling ability for the material to be modified. In order to increase the material removal rate, heavier ions than Ga and their clusters should be applied. Bismuth (Bi) is the heaviest, non-radio-active element in the periodic table, is non-toxic and exhibits a low melting point. We have thus produced a long-life (about 1000 h) Bi LMIS with a good beam performance, applicable in any FIB system. Since Bi is the only element in this source, it is not necessary to separate it from other ions by a mass filter. Investigation of the sputtering rate of NiTi shape memory alloys using Ga and Bi ...
A single plasma process involving three consecutive steps has been developed for producing high gas flow catalytic nanostructures on the electrodes of proton exchange membrane (PEM) fuel cells (FC). Using a high density helicon radio frequency (13.56 MHz) plasma, nickel is sputtered onto a porous carbon support. Changing the background gas from argon to methane/hydrogen allowed 2 ?m long, 37 nm diameter carbon nanofibres (CNFs) to be grown by diffusion through the nickel clusters in a 'tip growth' mechanism at the relatively low temperature of 400 deg. C. The third step involves plasma sputtering of platinum onto the CNFs, resulting in nanoclusters (3-8 nm) being formed on the periphery of the CNFs. Four FC cathodes were synthesized on carbon paper and PTFE/carbon loaded cloth (known as gas diffusion layer, GDL), both with and without CNFs, with the Pt/CNFs nanostructures grown on PTFE/carbon loaded cloth having the best FC performances. Compared with conventional ...
45{number_sign} steel, which has good mechanical strength and is relatively cheap, is a common constituent in industrial components, such as precision gears, piston columns of oil pumps, and so on. However, since the working environment of these industrial parts is sometimes quite harsh and unforgiving, they are vulnerable to wear and corrosion. Replacing 45{number_sign} steel with stainless or alloy steel increases the cost significant, and a better alternative is to improve its surface properties and lifetime using plasma immersion ion implantation (PIII). The authors have devised a variety of treatment processes using PIII, including radio-frequency (RF) plasma nitriding, RF plasma nitriding and nitrogen PIII, Ti deposition in conjunction with nitrogen PIII (IBED), as well as Cr deposition followed by nitrogen PIII (IBED). To assess the efficacy of the processes, the microhardness and mass loss due to wear were measured for both the untreated and treated ...
Studies have been conducted to determine the feasibility of using collisional cooling for reducing emittances and energy spreads in negative-ion beams to levels commensurate with effective isobaric purification with conventional high-resolution electromagnetic isobar separators as required for use at the Holifield Radioactive Ion Beam Facility (HRIBF). We have designed a gas-filled radio frequency quadrupole ion cooler equipped with provisions for retarding energetic negative-ion beams to energies below thresholds for electron detachment at injection and for re-acceleration to initial energies after the cooling process. The device has been used to cool several ion beams with initial energy spreads, {delta}E>10 eV to final energy spreads, {delta}E{approx}2 eV FWHM, including O{sup -} and F{sup -}. Overall transmission efficiencies of {approx}14% for F{sup -} beams have been obtained. Experimental results show that electron detachment is ...
The potential of ultrasonic guided modes for use in global structural health monitoring of aging metallic aircraft can only be realized if the modes selected are able to propagate over a reasonable distance. This work studies the propagation of different modes through fuselage structure by means of mode analysis, finite element modeling and experimental measurement. Beginning with the case of a simple skin panel, the paper examines propagation across a set of structural features representing a typical monocoque fuselage and considers the effect of overlying sealant layers, bonded and sealed joints, paint layers and tapering skin. With the exception of the fundamental symmetric mode at very low frequency, no mode was found that could propagate across all features with an effective attenuation of less than 40 dB/m. This makes global monitoring of a fuselage structure using a sparse array of transducers very difficult. However, more local ...
A systematic study of the Bragg nuclear resonant reflectivity from periodic multilayers in the energy and time domains is presented. Using the kinematical approach of the general reflectivity theory we describe the basic features of the time evolution of the reflected wave after a pulsed excitation of resonant multilayers by synchrotron radiation. Effects of the collective excitation have been examined such as the shift of quantum beat phases, the interplay between electronic and nuclear subsystem excitations depending on their relative position in a multilayer, the energy and time evolution of standing waves inside a resonant multilayer, and their influence on the reflectivity spectra. The exact expression for the reflectivity by a thin resonant layer placed inside a multilayer structure has been derived. The observed shift of the delayed reflectivity Bragg peak relative to the prompt peak is explained by the developed ...
The advances in laser technology have made available very short and intense laser pulses which can be used to seed a high-gain single-pass free-electron laser (FEL) amplifier. With these seed pulses, a regime of the FEL interaction where the radiation evolution is simultaneously dominated by nonlinear effects (saturation) and time-dependent effects (slippage) can be explored. This regime is characterized by the propagation of a solitary wavelike pulse where the power of the optical wave grows quadratically with time, its pulse length decreases and the spectral bandwidth increases. We analyze the interplay between the field and particle dynamics of this propagation regime which was studied before and termed super-radiance. Furthermore we analyze the properties of the strong higher-order harmonic emission from this wave and its behavior when propagating in a cascade FEL. The super-radiant pulse is indeed ...
We present a fully relativistic formalism for describing neutrino-induced $\\Delta$-mediated single-pion production from nuclei. We assess the ambiguities stemming from the $\\Delta$ interactions. Variations in the cross sections of over 10% are observed, depending on whether or not magnetic-dipole dominance is assumed to extract the vector form factors. These uncertainties have a direct impact on the accuracy with which the axial-vector form factors can be extracted. Different predictions for $C_5^A(Q^2)$ induce up to 40-50% effects on the $\\Delta$-production cross sections. To describe the nucleus, we turn to a relativistic plane-wave impulse approximation (RPWIA) using realistic bound-state wave functions derived in the Hartree approximation to the $\\sigma$-$\\omega$ Walecka model. For neutrino energies larger than 1 GeV, we show that a relativistic Fermi-gas model with appropriate binding-energy correction produces ...
Local-density-functional calculations of the energy bands, equilibrium lattice constant, bulk modulus, and cohesive energy have been performed using a newly developed self-consistent full-potential linearized augmented-plane-wave (LAPW) program. Scalar-relativistic effects are included for the band states, and the core-level states are treated fully relativistically in a central-field approximation. Excellent agreement is obtained with the experimental lattice constant and bulk modulus. Generally good agreement is obtained with the scalar-relativistic pseudopotential results of Bylander and Kleinman. In this context, the impact of various approximations used in including the core states is assessed, and these findings are related to the frozen-core and pseudopotential approximations, especially with regard to the treatment of the somewhat overlapping 5p semicore states and their effect on ground-state properties. Comparison ...
A Real-Time Neutron Radiography (RTNR) system is used to determine two-phase flow parameters for a horizontal co-current two-phase flow channel with a CANDU-type 37 rod bundle. Image processing techniques are applied to visualize the two-phase flow, and to determine flow regime, cross-sectional averaged void fraction, time averaged void fraction, and void distribution. The experimentally determined flow regime map disagrees with existing flow regime models developed for the CANDU-type rod bundles. A new flow regime is observed and designated Large Amplitude Stratified Wavy flow. The results show that the LASW flow regime may be due to a combination of undeveloped flow phenomena, boundary conditions, and circumferential cross flow occurring in the bundle. The rods in the bundle may act as a dampener to the vertical flow and hinders the development of the wave into plug or slug flow by changing the momentum of the fluid in the circumferential direction. The ...
A real-time neutron radiography (RTNR) system is used to determine two-phase flow parameters for a horizontal co-current two-phase flow channel with a cylindrical 37 rod bundle. Image processing techniques are applied to visualize the two-phase flow, and to determine flow regime, cross-sectional averaged void fraction, time averaged void fraction, and void distribution. The experimentally determined flow regime map disagrees with existing flow regime models developed for the cylindrical rod bundles. A new flow regime is observed and designated large amplitude stratified wavy (LASW) flow. The results show that the LASW flow regime may be due to a combination of undeveloped flow phenomena, boundary conditions, and circumferential cross flow occuring in the bundle. The rods in the bundle may act as a dampener to the vertical flow component and hinders the development of the wave into plug or slug flow by changing the momentum of the fluid in the circumferential ...
A Real-Time Neutron Radiography (RTNR) system is used to determine two-phase flow parameters for a horizontal co-current two-phase flow channel with a CANDU-type 37 rod bundle. Image processing techniques are applied to visualize the two-phase flow, and to determine flow regime, cross-sectional averaged void fraction, time averaged void fraction, and void distribution. The experimentally determined flow regime map disagrees with existing flow regime models developed for the CANDU-type rod bundles. A new flow regime is observed and designated Large Amplitude Stratified Wavy flow. The results show that the LASW flow regime may be due to a combination of undeveloped flow phenomena, boundary conditions, and circumferential cross flow occurring in the bundle. The rods in the bundle may act as a dampener to the vertical flow and hinders the development of the wave into plug or slug flow by changing the momentum of the fluid in the circumferential direction. The ...
The bibliography contains selected abstracts of research reports covering studies dealing with water pollution from estuarine and coastal development, the effects of this pollution, and its control. The reports are general in nature so as to be of interest to any coastal area. The topics include pollution as related to urbanization, government actions, coastal planning, natural resource development, and sewage and solid waste disposal. Specific biological and oceanographic studies have been excluded. (This updated bibliography contains 112 citations, 42 of which are new entries to the previous edition.)
A nonlinear relationship between the time of accelerated aging of Lupine seeds and the indices of its survival as well as the single-strand DNA amount in cells from these seeds is established. The character of this relationship is essentially altered in chronically irradiated lupine seeds from the Chernobyl NPP exclusion zone and seems more complicated. The possible role of repair systems in these effects is discussed. The fact that chronic irradiation in low doses can modify the course of senescence in lupine seeds reflects its high biological efficiency comparing with acute irradiation.
The long term goal is to determine the ecological importance of specific toxic metals (copper and zinc) in harbors, through an understanding of their chemistry and biologicaleffects at the base of marine food chains. This work provides information on potential problems with Zn and Cu, which may help to foresee problems in the future. Anthropogenic inputs of both metals are increasing; they are derived from diverse sources and are a simple function of population growth in coastal regions.
This year was spent in perfecting details of the new design blood irradiator, i.e., having male fittings made for shunt insertion and in acquiring preliminary biological data on its effectiveness. Fabrication of units was slowed by an unanticipated reaction of the resin with the steel injection mold, by occasional thrombogenic flaws in the blood interface layer, by thrombus formation at the points of connection to the shunt and by nonavailability of a reactor for activating the "1"6"9Tm to "1"7"0Tm. The remaining unsolved problem is that of thrombus formation at the connectors.
DescriptionThe nematophagous fungus, Pochonia chlamydosporia is a facultative parasite that has been developed through collaborative research between Rothamsted and the Centro Nacional de Sanidad Agropecuaria, Havana, Cuba, as the biocontrol agent Klamic against root-knot nematodes in tropical soils. The abundance of this fungus in soil is not necessarily related to its effectiveness as a biological control agent and its parasitic activity against nematode eggs is related to its nutrition and physiological [continued...
An investigation of the intensity of electromagnetic radiation at a wavelength of 185nm emitted by a General Electric mercury discharge, germicidal lamp is described. From the measurement of the transmission of light as a function of wavelength from 185nm to 360nm, it was concluded that this type of germicidal lamp does not produce any biological or chemical effects through the 185nm line; the intensity of the 185nm line transmitted by the lamp was less than 0.1% of that for the 254nm line. Consequently, there was no discernable ozone production. (U.K.).
Abstract Adalimumab is a fully human monoclonal anti-tumor necrosis factor-a agent that is approved for the treatment of Crohn's disease. It has a good safety profile, injection site reactions being the most common adverse effect. We report a case of a 54-year-old woman with a 30-year history of Crohn's disease who developed achromic patches on the trunk and upper extremities after initiating treatment with adalimumab. Cutaneous biopsy confirmed diagnosis of vitiligo and laboratory testing ruled out thyroid disease. Concomitant occurrence of vitiligo and inflammatory bowel disease, although rare, has been described. A common autoimmune basis could explain this fact. Moreover, multiple cutaneous adverse effects have been described in the literature secondary to biologic treatments, includin...
Background Previous reports in adults have suggested that the effects experienced after cannabis use can be described in terms of positive and negative subtypes that are heritable and are associated with abuse and dependence. This study extends existing research by inclusion of adolescents and young adults in an offspring of twins design which makes it possible to take into account genetic and environmental risks for substance use disorder. Methods Data were collected from 725 twin members of the Vietnam Era Twin Registry, 839 of their 12-32 year old biological offspring and 427 mothers. Offspring who had ever used cannabis (n=464) were asked the degree to which they typically experienced 13 subjective effects shortly after using cannabis. Latent class analysis (LCA) was used to derive sub...
Probable risks for the occurrence of somatic effects due to diagnostic radiology and nuclear medicine are summarised. The biological background of radiation carcinogenesis and epidemiological results are discussed. At the Leiden University Medical Centre the average effective dose per examination due to diagnostic radiology and nuclear medicine amount to 0.95 and 4.4 mSv, respectively. These values correspond well with the average values of 0.82 and 3.0 mSv reported for The Netherlands as a whole. Since radiological examinations are performed at a much larger frequency than nuclear medicine the relative collective dose for the first type of examinations is higher than the latter. Risk for occurency of malignancies are at least one order of magnitude lower than the hypothetical risk due to the background radiation typical of The Netherlands.
The primary objective of this study was to evaluate the potential environmental effects (both adverse and beneficials) of aquifer thermal energy storage (ATES) technology pertaining to microbial communities indigenous to subsurface environments (i.e., aquifers) and the propagation, movement, and potential release of pathogenic microorganisms (specifically, Legionella) within ATES systems. Seasonal storage of thermal energy in aquifers shows great promise to reduce peak demand; reduce electric utility load problems; contribute to establishing favorable economics for district heating and cooling systems; and reduce pollution from extraction, refining, and combustion of fossil fuels. However, concerns that the widespread implementation of this technology may have adverse effects on biological systems indigeneous to aquifers, as well as help to propagate and release pathogenic organisms that enter thee environments need to be ...
An important aspect of ecosystem sustainability is the ability to withstand and recover from disturbance or stress. In this study, we investigated the effect of a heat-disturbance on soil microbial biomass, microbial activity in response to the addition of organic acid (malate), and microbial community structure in a laboratory experiment. The soils investigated were from a jarrah (Eucalyptus marginata) forest that had undergone rehabilitation following bauxite mining 12 years previously. Soils from a full factorial of two field treatments; contour ripping induced micro-topography (mound or furrow) and prior exposure to prescription fire (burnt or non-burnt), were sampled and found to exhibit treatment-dependent differences in soil biological and chemical properties. Exposure of soil micro...
Ionizing radiations that differ in number, size, and distribution of energy deposition events might be expected to cause different effects for the same absorbed dose. Furthermore, microdosimetry calculations suggest that large variations in biologicaleffectiveness might be expected for internally deposited alpha-emitting radionuclides for the same absorbed dose, depending upon the specific activity and spatial distribution of the sources in tissue. The study described in this article was designed to demonstrate these phenomena in vitro. Cultured Chinese hamster ovary (CHO-K1 BH4) cells were exposed in vitro to inert, insoluble ceramic microspheres in zirconium dioxide labeled with "2"3"9Pu. The average exit energy of the 5.15 MeV alpha particle was calculated to be 4.3 MeV. Exposure times varied from four to seven hours to achieve the desired dose level.
Many species of entomophagous arthropods have been introduced either intentionally (through the practice of biological control) or unintentionally to new regions. We examine interactions of these aliens with their new environments in the context of rapid global change linked to human activity. We consider effects of such interactions on establishment and spread of the alien species and effects on indigenous biota and ecosystems. Major elements of global change that affect alien-environment interactions include landscape modifications by humans (e.g., cultivation, habitat loss and fragmentation) and increases in atmospheric CO2 and other gases resulting in climate change and other effects (e.g., changes in food quality for herbivores that affect higher trophic levels as well). Alien arthrop...
We consider a holographic description of a system of strongly-coupled fermions in 2+1 dimensions based on a D7-brane probe in the background of D3-branes. The black hole embedding represents a Fermi-like liquid. We study the excitations of the Fermi liquid system. Above a critical density which depends on the temperature, the system becomes unstable towards an inhomogeneous modulated phase which is similar to a charge density and spin wave state. The essence of this instability can be effectively described by a Maxwell-axion theory with a background electric field. We also consider the fate of zero sound at non-zero temperature.
A new scheme to accurately retain kinetic electron effects in particle-in-cell (PIC) simulations for the case of electrostatic drift waves is presented. The splitting scheme, which is based on exact separation between adiabatic and on adiabatic electron responses, is shown to yield more accurate linear growth rates than the standard df scheme. The linear and nonlinear elliptic problems that arise in the splitting scheme are solved using a multi-grid solver. The multi-grid particle-in-cell approach offers an attractive path, both from the physics and numerical points of view, to simulate kinetic electron dynamics in global toroidal plasmas.
The magnetic structure of a tetragonal Ce(Ru_0_._9_6Pd_0_._0_4)_2Si_2 single crystal, determined by neutron diffraction measurements, is similar to that observed in Rh doped alloys. The magnetic moments are oriented and modulated along the c-axis. Here the wave vector is incommensurate: k=(0,0,0.38). At 1.5 K, the moment is estimated to about 0.3 #mu#_B. Magnetization, magnetoresistance and Hall effect measurements performed on this alloy are also reported. (orig.).
In the context of the shock-initiation problem, we study analytically the first effects of chemistry, treating a small chemical heat release as a perturbation on an inert flow. Specifically, we study the initial transient in plane-shock initiation in a dilute explosive, where the chemical energy is small relative to the mechanical-thermal energy. The vehicle for the study is the mathematical analog for reactive flow. The solution resembles a double refraction: to first order, the pressure or density is a superposition of two forward-going waves, both originating at the rear boundary, and carrying the same function, but running at different velocities. Surprisingly, this first-order solution is independent of the sensitivity of the reaction rate to the state, which appears only at second order.
Full text: The general population is daily exposed to chronic, low doses of ionizing radiation (IR) from both natural and artificial sources. The biological consequences of acute, high dose IR exposure can be readily determined; however, the nature and significance of low dose, low dose-rate IR effects are still the subject of debate. Confounding the issue, are the phenomena collectively referred to as the Radiation-induced Bystander Effect (RIBE). The RIBE describes a collection of in vitro observations that suggest the presence of a soluble, transmissible factor(s) released from irradiated cells that can induce a biological response in un-irradiated cells. The induction, nature and magnitude of the RIBE varies between cell culture systems, radiation sources and end-points measured. Efforts to confirm the presence of the RIBE in vivo have been confined to in vivo-like culture systems and limited work ...
Reduction of the metallic impurity concentration in the TCA plasma has enabled us to correlate the observed heating with the calculated position where the rf energy is deposited. In modelling the measured antenna loading due to the presence of Alfven resonance surfaces, and hence inferring the energy deposition profile, both ion cyclotron effects and the toroidal geometry must be considered. In particular, toroidicity couples energy to resonance surfaces that would not be excited in cylindrical geometry. The increase in electron density during a rf pulse changes the positions of these surfaces so that spectrum-related effects may be observed. The appearance of a new surface at the centre of the plasma is seen as a sharp discontinuity on many of the macroscopic parameters, accompanied by evidence of changes in the current density profile. These results, and the predictions of numerical codes, have imposed new constraints on the optimisation of ...
The authors obtain the critical load levels corresponding to the onset of spalling microdamage for Armco iron and steels St.3 and 12Kh18N10T in a broad temperature range (-196-800 degrees C. The results of the investigation of the effect of the temperature on spalling fracture are presented. The effect of the loading time on the strength of the investigated materials is also given. The authors assume that at -196 degrees C impact-wave strain-hardening may also be characterized by the value of H obtained for the center of the specimen since measurements on great thicknesses, including those reaching as far as the opposite surface, did not reveal any substantial change of microhardness.
Systems biology is a rapidly expanding field that integrates diverse areas of science such as physics, engineering, computer science, mathematics, and biology toward the goal of elucidating the underlying...Full Text Available
...and biological processes acting on recruitment and post-recruitment EU-Agrinet - Project sheet: Biological performance testing methodology to evaluate the durability of plywood as a quality indicator ... Project sheet: Biological performance testing methodology to evaluate the durability of plywood as a quali EU-Agrinet - Project sheet: Genetic evaluation of European ...
Hair is preserved for millennia in permafrost; it enshrines a record of biologic rhythms and offers a glimpse at chronobiology as it was in extinct animals. Here we compare biologic rhythms gleaned...Full Text Available
A human cholangiocarcinoma, Ch-1, serially transplanted to nude mice was used for experimental chemotherapy, radiotherapy, and conbination chemoradiotherapy. In the group of chemotherapy with single drug, Mitomycin C (MMC) revealed greater effectiveness than Adriamycin in terms of tumor regression, histological findings, and minor side effects. MMC and radiotherapy by Linac X-ray showed exponential linear dose response curve against tumor weight. Their effects were equivalent at doses of MMC 1 mg/kg and radiation 1,000 rads/mouse in the changes of tumor weight and of histological findings which were similar to each other. Combination chemoradiotherapy showed the synergistic action when the radiation (500 rads/mouse) was performed before MMC (0.5 mg/kg) administration, whereas only the additive effect was observed when the sequence was reversed. The cell kinetic analysis was performed by the impulse ...
Several systems have been developed to accomplish vehicle location. The systems consist of three types: Dead Reckoning, Satellite, and LORAN C. If the information is to be sent back to a central location, some type of radiocommunication system is needed. One can use the existing voice radio or add a radio system just for transmitting the data.
This report deals with the selection of a data communication system for a remote metering system. It covers the following three types of systems: fiber optic, telephone line, and radio packet. It provides a methodology for selecting a communication system for a given remote metering system and a method for comparing costs.
Characteristics of inertia gravity waves associated with convection are investigated in the lower stratosphere using high-resolution radiosonde data observed from 18 June to 15 July of 2005 and 2007 in Korea. Three-dimensional ray-tracing model and reanalysis data are used to investigate the propagation and the sources of the observed waves. The observed waves associated with convections are discriminated based on the existence of convections when and where the rays reach the average height range of convective clouds. Waves observed in 2005 and 2007 show similar spectral characteristics, but wave energy in 2007 is significantly larger than in 2005. The observed waves propagate from three source regions: the northeastern, southeastern, and western regions around Korea. They show preferential propagation directions based on their sources, and convections from the ...
Combinations of exposure concentrations, durations and frequencies were tested in four-week inhalation exposures followed by two weeks of recovery to define the interactive effects of these variables on biologic responses and to select the most-sensitive biologic response parameters for the subsequent subchronic studies. Response surface modeling was used for the experimental design and statistical analysis of the data. Results of preliminary testing suggested that exposure duration and frequency did not have major effects. Subsequently, male and female Sprague-Dawley rats were exposed in separate studies to RP/BR aerosols ranging from 0.40 to 1.20 mg/1 or to filtered air for 2.25 hr/day on four days/week for four weeks. Test-atmosphere monitoring data demonstrated that aerosol concentrations were consistently within 4% of the target values and mean particle size ranged from 0.44-0.64 ..mu..m with mean ...
We aim to obtain a consistent description of non-thermal emissions from Abell 2256 and to give a prediction for a gamma-ray emission from this galaxy cluster. Assuming that a radio relic illuminates a localization of an ongoing merger, and that both radio and non-thermal part of hard X-ray emission are due to electron component of cosmic rays filling the relic, we derived from radio and hard X-ray properties of the relic in A2256 the magnetic field strength and number densities for relativistic electrons and protons. Due to the interpretation of the radio relic as a structure formed just where a shock front is, we discuss a gamma-ray emission at the cluster periphery. The estimated strength of the magnetic field in the relic is equal to 0.05 \\muG, while the amplitude of the electron number density varies from 3 x 10^{-4} to 3 x 10^{-5} cm^{-3} (respectively for the relic thickness of 50 to 500 kpc). We ...
Results reported are for single dose exposures and refer to "6"0Co-#gamma#-irradiation. The RBE determined by V79 cell survival and based on the Do ratio was found to be 1.70#+-#0.4 ranging from 1.5 to 1.8. In the case of the regeneration of mouse jejunal crypts the RBE was calculated at ten cell curvival and was found to be 1.68. The maximum acute mouse skin reaction at a skin score of 2.0 was found to be 2.1 while the average skin reaction was 1.7. Growth retardation of Vicia faba bean roots measured at the level of 50% indicated an average RBE of 3.0 and a range of 2.7 to 3.7. The OER obtained for V79 cell survival was found to be 1.7 to 1.8. Comparison is made with the RBE and OER measurements for the neutron facilities at Clatterbridge, Fermilab and Louvain-la-Neuve which produce neutrons by the same nuclear reaction and whose physical specifications closely resemeble those of the Faure neutrons. This comparison indicates that the Faure beam shows no unusual ...
Microsecond pulse radiolysis of oxygenated aqueous solutions containing 0.02 mol dm"-"3 sodium formate and 2 mmol dm"-"3 phosphate buffer at pH 7 was used to generate superoxide anion radicals. The influence of some biologically important compounds upon the rate of O_2"."-"b"a"r decay as monitored spectrophotometrically in the range of 245-300 nm. Hematoporphyrin (HP), hemin C (HC), catalase (Cat), cobalt sulfophthalocyanine (CoTSPc) were studied. Among the investigated compounds only Cat was found to show a high catalytic efficiency towards the self-decay of O_2"."-"b"a"r. A red shift of 0_2"."-"b"a"r absorption band and slowing down of its decay were observed to take place by adding HP or CoTSPc to the solutions containing formate ions in excess. This effect is associated with the formation of a transient superoxo-complex. An appearance of an intermediate species with absorption maxima at 350 nm and half-life of about 2 s was observed to ...
Ballistics involves the study of the scientific properties of projectiles, their behavior and their terminal effects on biological tissues and other materials. Wound ballistics deals with the analysis of injuries caused by projectiles and the behavior of projectiles within human or other biological tissues. The nineteenth century witnessed the development of both of these areas with Kocher's hydrodynamic theory and the understanding of the significance of bullet deformation in causing tissue injury. The degree of traumatic disruption of tissues and organs was also related to direct energy transfer from projectiles. While subsequent research has concentrated on elucidating further mechanisms of injury, the exact cause of remote tissue damage from high energy projectiles is still the subject of ongoing research. Much of the contemporary literature regarding wound ballistics concentrates on the forensic aspects and their ...
Molecular imaging represents a modern research area that allows the in vivo study of molecular biological process kinetics using appropriate probes and visualization methods. This methodology may be defined- apart from the contrast media injection - as non-abrasive. In order to reach an in vivo molecular process imaging as accurate as possible the effects of the used probes on the biological should not be too large. The contrast media as important part of the molecular imaging can significantly contribute to the understanding of molecular processes and to the development of tailored diagnostics and therapy. Since more than 15 years PTB is developing optic imaging systems that may be used for fluorescence based visualization of tissue phantoms, small animal models and the localization of tumors and their predecessors, and for the early recognition of inflammatory processes in clinical trials. Cellular changes occur during ...
Increasingly, governments enact more stringent regulations governing nitrogen and phosphorus in the discharge effluent of wastewater treatment plants. Scientists know that nitrogen and phosphorus accelerates the eutrophication of lakes and reservoirs and stimulates algal growth. Ammonia has proven to be toxic to aquatic life forms, including fish. Engineers favour Biological Nutrient Removal (BNR) over chemical addition to wastewater treatment. Sequencing Batch Reactors (SBRs), a type of bioreactor requiring less land, provide the anaerobic, anoxic, and aerobic zones necessary for BNR. Methanol was used as an effective external source of carbon for denitrification but lacked research. The authors remedied this situation and some of the results were available. They indicated that the addition of methanol in the SBR increased solids production in the SBR, leading to increased sludge wasting to the aerobic digester. All aspects of the sludge ...
This publication provides a broad overview of the research programs and efforts being conducted, built, designed, and planned at Brookhaven National Laboratory. This work covers a broad range of scientific disciplines. Major facilities include the Alternating Gradient Synchrotron (AGS), with its newly completed booster, the National Synchrotron Light Source (NSLS), the High Flux Beam Reactor (HFBR), and the RHIC, which is under construction. Departments within the laboratory include the AGS department, accelerator development, physics, chemistry, biology, NSLS, medical, nuclear energy, and interdepartmental research efforts. Research ranges from the pure sciences, in nuclear physics and high energy physics as one example, to environmental work in applied science to study climatic effects, from efforts in biology which are a component of the human genome project to the study, production, and characterization of new ...
This publication provides a broad overview of the research programs and efforts being conducted, built, designed, and planned at Brookhaven National Laboratory. This work covers a broad range of scientific disciplines. Major facilities include the Alternating Gradient Synchrotron (AGS), with its newly completed booster, the National Synchrotron Light Source (NSLS), the High Flux Beam Reactor (HFBR), and the RHIC, which is under construction. Departments within the laboratory include the AGS department, accelerator development, physics, chemistry, biology, NSLS, medical, nuclear energy, and interdepartmental research efforts. Research ranges from the pure sciences, in nuclear physics and high energy physics as one example, to environmental work in applied science to study climatic effects, from efforts in biology which are a component of the human genome project to the study, production, and characterization of new ...
Following the publication (Stenhouse and Baxter, Nature; 267:828 (1977)) of the levels of bomb "1"4C and the residence times of carbon in the human body, excess radiation burdens from this radioisotope are evaluated under the assumption that no radiation dose, however small, can be regarded as entirely harmless biologically. The estimated annual absorbed dose attributable to "1"4C both natural and man-made for 1953-1973 and similar predicted figures for 1975-2025 are shown graphically. The cumulated doses to gonads (over 30 yr) and to bone marrow and bone-lining cells (over 60 yr) and also estimates of the biological damage to reproductive cells from "1"4C #beta#-irradiation (30 yr accumulated dose) are presented. It is concluded from both genetic and somatic considerations, that the potential human radiation burden due to artificially produced "1"4C calculated using the assumptions stated is certainly significant and, therefore, cannot be ...
In this paper, we investigate the dynamic behaviors of a two-prey two-predator system with impulsive effect concerning biological and chemical control strategy-periodic releasing natural enemies and spraying pesticide at different fixed time. By applying the Floquet theory of linear periodic impulsive equation and small amplitude perturbation method, we prove that there exists a globally asymptotically stable two-prey-eradication periodic solution when the impulsive period is less than some critical value. The conditions for the permanence of the system are given, and meanwhile the conditions for the extinction of one of the two prey species and permanence of the remaining three species are given. Our results suggest a new approach in pest control. The target pest population can be driven to extinction and the non-target pest can be permanent by choosing impulsive period. With the increasing of the predation rate for the super competitor and ...
Attention deficit hyperactivity disorder (ADHD) is one of the most common behavioral disorders in children. Symptoms of ADHD include hyperactivity, low frustration tolerance, impulsivity, and inattention. While the biological pathways leading to ADHD are not clearly delineated, a number of genetic and environmental risk factors for the disorder are recognized. In the early 1970s, research conducted by Dr. Benjamin Feingold found that when hyperactive children were given a diet free of artificial food additives and dyes, symptoms of hyperactivity were reduced. While some clinical studies supported these findings, more rigorous empirical studies conducted over the next 20 years were less positive. As a result, research on the role of food additives in contributing to ADHD waned. In recent years, however, interest in this area has revived. In response to more recent research and public petitions, in December 2009 the British government requested that food ...
The overall objective of this project has been to develop immunochemical methods to quantitate unique DNA base damages in order to facilitate studies on radiation-induced damage production and repair. Specifically, we have been using antibodies raised to damaged bases to quantitate unique lesions in model systems in order to evaluate their potential biological consequences. Our approach has been to synthesize modified nucleotides or nucleosides, conjugate them to protein carriers, and use the conjugates as immunogens in rabbits or to prepare monoclonal antibodies. We have been studying damages that are stable radiolysis products found in X-irradiated DNA and thus of potential biological consequence. Our aim is to build an in vitro and in vivo data base on the interactions between model DNA lesions and such cellular enzymes as DNA polymerases and repair endonucleases. Initial studies have focused on pyrimidine ring saturation products (thymine ...
The overall objective of this project has been to develop immunochemical methods to quantitate unique DNA base damages in order to facilitate studies on radiation-induced damage production and repair. Specifically, we have been using antibodies raised to damaged bases to quantitate unique lesions in model systems in order to evaluate their potential biological consequences. Our approach has been to synthesize modified nucleotides or nucleosides, conjugate them to protein carriers, and use the conjugates as immunogens in rabbits or to prepare monoclonal antibodies. We have been studying damages that are stable radiolysis products found in X-irradiated DNA and thus of potential biological consequence. Our aim is to build an in vitro and in vivo data base on the interactions between model DNA lesions and such cellular enzymes as DNA polymerases and repair endonucleases. Initial studies have focused on pyrimidine ring saturation products (thymine ...
The authors emphasize the importance of stability in biological standards and discuss the steps taken to ensure the stability of International Standards and the theoretical basis of the various stability...Full Text Available
... L. Sutton. 2000. Is the aquatic weed hygrophila, Hygrophila polysperma (Polemoniales: Acanthaceae), a suitable target for classical biological ... ...
The basic biology of the menstrual cycle is a complex, coordinated sequence of events involving the hypothalamus, anterior pituitary, ovary, and endometrium. The menstrual cycle with all its...Full Text Available
Models can be useful at many different levels when considering complex issues such as biological control of mosquitoes. At an early stage, exploratory models are valuable in exploring the characteristics...Full Text Available
The Liver Carcinogenesis Section uses the modern technologies of molecular biology, cell biology, protein chemistry and genetics to investigate the biochemical and genetic pathways involved in human liver cancer.
Aging is a biological process that affects most cells, organisms and species. Human aging is associated with increased susceptibility to a variety of chronic diseases, including cardiovascular disease,...Full Text Available
Genetics, Genomics, and Molecular Biology USGS scientists develop and integrate new genetic and molecular techniques into systematic analyses to describe individuals and populations of fish .....
This report is devoted to the investigation of the influence of electron collisions and radial non-uniformity of plasma density on phase characteristics, spatial attenuation and wave field structure of slow symmetric electromagnetic waves that propagate along cylindrical waveguide structure. It has been shown that collision rate and radial non-uniformity of plasma density for various parameters of waveguide structure and dielectric affect essentially on the wave characteristics and consequently, on the parameters of gas discharge that is sustained by this wave. The results obtained are of large importance for the construction of the theory of gas discharges that are sustained by the surface electromagnetic waves.
A concept of a traveling wave direct energy converter (TWDEC) is developed for 14.7-MeV fusion protons based on the principle of a backward wave oscillator. Separation of fusion protons from thermal ions is accomplished by using ExB ion drift. Energy conversion rate up to 0.87 is attained by applying three-stage modulation of the proton beam. A one-dimensional particle-circuit code is developed to examine self-excitation of the traveling wave and its stability under loading. Electrostatic wave with a fixed frequency is excited spontaneously, and stability of the wave is ensured under loading. (author).
Estimations on the somatic and genetic effects of small doses of ionizing radiations in Man have been proposed by the Advisory Committee on the BiologicalEffects of Ionizing Radiation, set up by the U.S. National Academy of Sciences. They have been published in an important report, issued in 1972, from which we briefly analyze here the Chapter dealing with the somatic effects. Small doses of raditions are expected to promote only carcinogenic effects. After a rapid survey of the human experience on which the estimations are based, as regards the latent period of cancers, the plateau region (period of high risk) and the absolute and relative risk expressed per rem, per 10"6 persons, per year, for leukaemia (having the highest risk) and for the ''other cancers''. These estimations were obtained by linear extrapolation to the 1 rem level from observations made after irradiation at ...
Low resolution visual polarimetric photographic imagery of the Galveston Bay oil spill from a tanker accident on July 28, 1990 was obtained and analyzed. The low resolution imagery (30 to 100 meters) was obtained concurrently with high resolution (1 meter), and is representative of what would be seen by a polarimetric satellite. Orthogonal red-green-blue (RGB) polarimetric images obtained with color photography were digitized by KODALUX on to a CD ROM. These polarimetric images were then used to calculate the percent polarization. The positive and negative percent polarized radiation scattered by each of the sea surface waves is seen individually in high resolution imagery. (Percent polarization is defined as positive when the dominant radiation is perpendicular to the plane of incidence and negative when it is parallel). The analysis of low resolution polarimetry is approached in a different manner than high resolution; in high resolution, individual ...
The electronic band structure, transport properties, and lattice dynamics in AuX_2 (X = Al, Ga and In) under high pressure have been extensively studied with full potential linearized augmented plane wave and pseudopotential plane wave methods. The theoretical results for the electronic band structure and Fermi surface reveal pressure-induced electronic topological transitions (ETTs) in AuGa_2 and AuIn_2, while they are absent in AuAl_2, in excellent agreement with the experimental observations. Moreover, calculations of the transport properties at different pressures reveal subtle changes in the band structure close to the Fermi surface of the three intermetallic compounds. It is clear that the anomalies in transport properties are due to ETTs. Interestingly, a pressure-induced soft transverse acoustic (TA) phonon mode is identified only in AuGa_2. The TA phonon instability at the Brillouin zone boundary L point might be responsible for the ...
The cold-worked Zr-2.5%Nb alloy is used as material for the pressure tubes in CANDU nuclear reactors. During the service life in reactor, diffusion of hydrogen and/or deuterium in the pressure tubes wall occur. Below a certain temperature, a stable hydride of zirconium is formed, as a brittle phase which can lead to catastrophic failures. For this reason, it is very important to be able to investigate the hydrogen effect on the micro structural properties of zirconium alloys. In the present paper a non-destructive testing technique is used, known as ultrasonic spectral analysis. When an ultrasonic signal traverses a medium, the frequency components associated with the input signal are altered. By frequency analysing the reflected signals, it is possible to study and compare the material properties. The two major parameters measured in ultrasonic spectroscopy are the attenuation and the velocity of the waves. Attenuation is determined by the ...
Several observational studies suggest that solar wind dynamic pressure fluctuations can drive magnetospheric ultra-low frequency (ULF) waves on the dayside. To investigate this causal relationship, we present results from Lyon-Fedder-Mobarry (LFM) global, three-dimensional magnetohydrodynamic (MHD) simulations of the solar wind-magnetosphere interaction. These simulations are driven with synthetic solar wind input conditions, where idealized ULF dynamic pressure fluctuations are embedded in the upstream solar wind. In three of the simulations, a monochromatic, sinusoidal ULF oscillation is introduced into the solar wind dynamic pressure time series. In the fourth simulation, a continuum of ULF fluctuations over the 0-50 mHz frequency band is introduced into the solar wind dynamic pressure time series. In this numerical experiment, the idealized solar wind input conditions allow us to study only the effect of a fluctuating solar wind dynamic ...
The standards mapping methods are limited by the lack of information between surface measures and wells profiles. The cross well seismic survey has proven being an effective high-resolution method for reservoirs characterization due its high frequency band. In this work, a 2-D finite differences algorithm for numerical cross well seismic simulation was developed, based in the approach of 2nd order for the time derivatives and 4th order for the space derivatives. In relation to the imaging techniques, it was introduced a reverse time migration method based in the solutions of the wave equation in time for cross well seismic data by the method of the finite differences exclusively. The results of reverse time migration has showed that layers with 90 cm thickness for P-waves could be visualized in migrated sections with excellent resolution. The high frequency cross well seismic data combined with reverse time migration have ...
In this work we study the structural and electronic properties of Be chalcogenides (BeS, BeSe and BeTe) using two different methods: the full-potential linear augmented-plane wave (FP-LAPW) and the plane-wave pseudopotential (PPsPW). The exchange-correlation effects are treated in the local-density approximation (LDA) and the generalized-gradient approximation (GGA). We have evaluated the ground-state quantities such as equilibrium volume, bulk modulus and its pressure derivative as well as the elastic constants. Various structural phase transitions were considered here in order to confirm the most stable structure and to predict the phase transition under hydrostatic pressure. In addition we have studied the band structure and the density of states, which show a wide indirect band gap for these compounds. These results were in favourable agreement with previous theoretical works and the existing experimental data. To ...
When quantum molecular dynamics (QMD) is applied to the nuclear reactions in theory of relativity region, a number of problems arise, and in order to solve them, the prescription of the extension of ordinary nonrelativistic QMD is introduced, and the analysis of proton incidence reaction by using it is shown. By introducing the interaction corresponding to Lorentz transformation, the problems were solved. QMD is the semiclassical simulation that treats the motion of nucleons represented by Gauss wave packet. The motion of wave packet center is expressed by Newton equations and two-nucleon collision. The introduction of the interaction corresponding to Lorentz transformation is explained. As the result of the introduction, through the relative distance of two particles, the interaction becomes to depend on momentum. The phase distribution function of one body corresponding to Lorentz transformation is used for calculating the final state Pauli ...
The marine reactor MRX, an integral typed PWR with 100 MWt adopts one-through steam generators with coiling tubes. The cold feed water enters the steam generator and the super heated steam flows out. To avoid occurrence of flow instability in the steam generator due to a density wave oscillation, it is necessary to increase of flow resistance at the feed water inlet. The magnitude of flow resistance to stabilize the flow is determined by a simple linear analysis using a D-division method, of which accuracy is clarified by comparison with SRI's experiment. The external force due to heaving, one of ship motions will affect the flow behavior. Analysis by a modified RELAP5 capable of simulating the ship motions reveals that the effect of heaving becomes especially greater when the state of flow approaches both the conditions of density wave oscillation occurrence and resonance of flow oscillation with heaving. (author)
The 1H NMR, electronic absorption, and luminescence spectra, as well as voltammograms of the reduction and oxidation of the complexes [Pd(C?N)(N?N)]ClO4 and [Pd(C?N)(?-OOCCH3)]2 [where (C?N)? is deprotonated 2-phenyl-4,5-dihydro-1,3-oxazole, and N?N is ethylenediamine or 2,2?-bipyridine (bpy)] were compared. Magnetic nonequivalence of protons in the dihydrooxazole ring and upfield shift of the corresponding signals were observed as a result of anisotropic effect of the ring current in palladated phenyl substituents in the [Pd(C?N)(?-OOCCH3)]2 complex having a C 2 symmetry. One-electron reduction wave of [Pd(C?N)bpy]+ was assigned to ligand-centered electron transfer to the ?* orbital of 2,2?-bipyridine, and two oxidation waves of [Pd(C?N)(?-OOCCH3)]2 were attributed to successive one-elect...
Over the last several years considerable concern has been expressed regarding the potential detrimental effects of radon and radon progeny on our health. The complex nature of the radon decay scheme, which involves the emission of a variety of radiations including several [alpha] particles, [beta] particles, and [gamma]-rays, does not lend itself to clear delineation of the biologicaleffects of the [alpha] particles alone. Polonium-210, the terminal radionuclide of the radon decay series, is useful for this purpose because it has a relatively long shelf-life ([tau][sub 1/2] = 138 d), and it only emits a single 5.3 MeV [alpha] particle in its decay to stable [sup 206]Pb. Accordingly, it has been used extensively in radiobiological studies with incorporated radionuclides. The radionuclide [sup 210]Po is produced in a reactor from [sup 209]Bi. (Author).
The authors summarize the significant dose-related effects on brain development which have emerged largely within the last six years of study of prenatally exposed A-bomb survivors. The results are described primarily in terms of the DS86 estimates and differences between these and the older T65DR dose estimates are discussed. The severe mental retardation sample was based on 1598 individuals taken from the PE-86 sample, and the intelligence test scores considered from the same sample involved 1673 children. The authors also discuss some of the recent neurobiological developments that appear relevant to an understanding of the biological bases of dose-related events observed, and suggest future research that may contribute either to further delineation of exposure consequences or to the explanation of the cellular and molecular origins of observed effects. (UK).
The biologicaleffects of ionizing radiation exposure are the result of a complex sequence of physical, chemical, biochemical, and physiological interactions. One way to begin a search for an understanding of health effects of radiation is through the development of phenomenological models of the response. Many models have been presented and tested in the slowly evolving process of characterizing cellular response. A range of models covering different endpoints and phenomena has developed in parallel. Many of these models employ similar assumptions about some underlying processes while differing about the nature of others. An attempt is made to organize many of the models into groups with similar features and to compare the consequences of those features with the actual experimental observations. It is assumed that by showing that some assumptions are inconsistent with experimental observations, the job of devising and ...
Summaries are included of research contracts which expired prior to Dec. 31, 1960. The contracts were concerned with investigations of: electrophysiological responses of biological systems in nerve cells to irradiation with small doses of ionizing radiations; the mode of the protective action of certain sulfhydryl compounds against radiation effects on the synthesis of deoxyribonucleic acid, using tritium-labeled thymidine; development of a bubble chamber method of monitoring and dosimetry for Low fast neutron fluxes; effects of incorporated radioisotopes on the stability of genetic materials; interrelation of root and leaf absorption of radioisotopes in herbaceous plants; uptake of radioactive wastes by lowland rice from soils contaminated by irrigation water, and decontamination of the rice; and comparison between mutation rates induced by acute and chronic gamma irradiations. (B.O.G.)
The role of adaptation in the divergence of lineages has long been a central question in evolutionary biology, and as multilocus sequence data sets have become available for a wide range of taxa, empirical estimates of levels of adaptive molecular evolution are increasingly common. Estimates vary widely among taxa, with high levels of adaptive evolution in Drosophila, bacteria, and viruses but very little evidence of widespread adaptive evolution in hominids. Although estimates in plants are more limited, some recent work has suggested that rates of adaptive evolution in a range of plant taxa are surprisingly low and that there is little association between adaptive evolution and effective population size in contrast to patterns seen in other taxa. Here, we analyze data from 35 loci for si...
According to biological and chemical control strategy for pest control, we investigate the dynamics of a predator-prey food chain with impulsive effect, periodic releasing natural enemies and spraying pesticide at different fixed times, by using impulsive differential equation. Choose pest birth rate r{sub 2} as control parameter, we show that there exists a stable pest-eradication periodic solution when r{sub 2} is less than some critical value r{sub 2}* and the system is permanence when r{sub 2} is larger than the critical value r{sub 2}*. By use of standard techniques of bifurcation theory, we prove that above this threshold there are periodic oscillations in prey, middle-predator and top predator. Furthermore, bifurcation diagrams have shown that there exists complexity for the pulsed system including periodic doubling cascade.
Wavy interface morphology is observed in Magnetic Pulse Welding (MPW) similarly to that of the Explosion Welding process (EXW). It is recognized that interfacial waves are formed in a periodic manner and have well defined wavelength and amplitude. The phenomenon of wave formation in EXW has been subjected to extensive investigations in which empirical and numerical models have been published. In the present study, a wave formation mechanism for MPW is presented. This wave-creation mechanism was studied by evaluating the influence of sample geometry on wave morphology using stereoscopic optical microscopy. It was found that interfacial waves are formed in a Kelvin-Helmholtz instability mechanism. Reflected shock waves interact with the welding collision point at the weld interface, where in...
We write a space-time Feynman Path Integral representation for scattered wave fields from a weakly/compact supported anisotropic non-homogeneity. (author)
AbstractWe propose a mechanism for the formation of membrane oscillations and traveling waves, which arise due to the coupling between the actin cytoskeleton and the calcium flux through...Full Text Available
An analysis is presented of the electron temperature in a linear device which includes the effect of thermal conduction, heat flux limit, radiation, and end plugs. It is found that the thermal conduction and the heat flux limit are dominant in the initial phase of cooling, while the later phase is almost completely controlled by radiation that spatially homogenizes the temperature distribution. In the case of bremsstrahlung, within the frame of the present model, the temperature decays to zero in a finite time. This process takes the form of a cooling wave that moves from the ends of the column to the center. Impurities cause a milder, exponential decay, which is still much faster than the algebraic conduction decay. The thermal effectiveness of the end plugs is described by a convective transfer coefficient h/sub p/. Its scaling law (in terms of the coupled plamsa-plug system) reveals that a very high plug-plasma density ...
We have investigated the effect of excimer laser annealing (ELA) on transient enhanced diffusion (TED) and activation of boron implanted in Si during subsequent rapid thermal annealing (RTA). It is observed that ELA with partial melting of the implanted region causes reduction of TED in the region that remains solid during ELA, where the diffusion length of boron is reduced by a factor of #approx#4 as compared to the as-implanted sample. This is attributed to several mechanisms such as liquid-state annealing of a fraction of the implantation induced defects, introduction of excess vacancies during ELA, and solid-state annealing of the defects beyond the maximum melting depth by the heat wave propagating into the Si wafer. The ELA pretreatment provides a substantially improved electrical activation of boron during subsequent RTA.
Hemolysis induced by long-wave ultraviolet radiation (UVA) and 8 different commercial tetracycline derivatives was studied in a model using human red blood cells. Demethylchlortetracycline and doxycycline were shown to have pronounced hemolytic properties causing 88% and 85% hemolysis, respectively, at a concentration of 50 micrograms/ml and 72 J/ cm2 of UVA. Tetracycline, oxytetracycline, and chlortetracycline caused maximally 18% hemolysis at 200 micrograms/ml and lymecycline only 7% at 100 micrograms/ml. Methacycline showed intermediate hemolytic effect of 36% at 200 micrograms/ml. Minocycline had no hemolytic effect whatsoever. These experimental data correlate very well with clinical reports and comparative phototoxicity trials in humans. Photohemolysis may thus be of value for predicting tetracycline phototoxicity.
An evolutionary model of dynamical processes in protostellar disks is described and illustrated with graphs of typical results. The effective transport mechanisms are discussed, including thermal convection, nonaxisymmetric gravitational instabilities in the outer regions of disks, and wave propagation. Consideration is then given to the stages of dynamical evolution, FU Ori outburst phenomena, unsteady accretion-disk flows, and nonlinear feedback as a mechanism to modulate mass transfer. The simulations show that mass redistribution is determined by angular-momentum transfer, which in turn is regulated by the effective viscosity generated by convectively driven turbulence. Significant mass transfer occurs as a result of mixing of infalling material with disk gas and is affected by the tidal torque associated with the growth of nonaxisymmetric disturbances in the outer disk. The time scale for disk evolution is found to be ...
This paper describes a nonlinear dynamic analysis of TVA high energy line pipe whip tests using the ABAQUS-EPGEN code. The analysis considers the effects of large deformation and strain rate on resisting moment and energy absorption capability. The numerical results of impact forces, impact velocities, pipe strains, and reaction forces at pipe supports are compared to the TVA test data. The calculated pipe whip impact time and forces are also compared with those predicted using current industry practice. The calculated pipe support reaction forces are found to be in good agreement with the TVA test data except for some peak values at the very beginning of the pipe break. These peaks are believed to be due to stress wave propagation which cannot be addressed by the ABAQUS code. Both elbow crushing and strain rate have been approximately simulated. The effects are found to be important for pipe whip impact evaluation.
The effects of thermal radiation and viscous dissipation on magneto-hydrodynamic (MHD) unsteady free-convection flow over a semi-infinite vertical porous plate are analysed. The fluid considered is non-gray (absorption coefficient dependent on wave length). The Network Simulation Method is used to solve the boundary-layer equations based on the finite-difference formulation; only discretization of the spatial co-ordinates is necessary, while time remains as a real continuous variable. This method provides a solution for both transient and steady-state problems at the same time, and programming does not require manipulation of the sophisticated mathematical software that is inherent in other numerical methods. The velocity, temperature, local skin-friction and local Nusselt number are studi...
We investigate two routes to obtain negative group velocity bands in two-dimensional phononic crystal structures. The negative dispersion originates from the resonances of sub-wavelength building blocks and as such, the system should be regarded as acoustic metamaterials. The first kind of acoustic metamaterial exhibits effectively negative bulk modulus and negative mass density simultaneously. Monopolar and dipolar Mie resonances are combined to achieve an effective medium with negative refractive index. In particular, we present a double negative metamaterial for airborne sonic waves. We then show that we can obtain negative group velocity from quadrupole resonances, and the result is explained using the quasi-static approximation. The negative dispersion in quadrupole bands cannot be de...
A detailed study has been performed for estimating the orbital energies, positions and shifts of the Lyman lines of C5+, Al12+ and Ar17+ under strongly coupled plasma with a view to understand such line positions and shifts obtained in laser produced plasma experiments. The effect of strongly coupled plasma has been treated within the Ion Sphere (IS) model. Both non-relativistic and relativistic methods have been used for estimating the spectral properties. Theoretical estimates with IS model of the plasma are in conformity with the results of laser plasma experiments on these highly stripped ions. The experimental data for the systems have also been compared with the theoretical estimates using Debye screening model of the plasma with spatial confinements which gives additional restrictions to the wave functions at finite boundaries.
Ultra-short-pulse reflectometry is studied by means of the numerical integration of a one-dimensional full-wave equation for ordinary modes propagating in a plasma. The numerical calculations illustrate the potential of using the reflection of ultra-short-pulse, microwaves as an effective probe of the density profile even in the presence of significant density fluctuations. The difference in time delays of differing frequency components of the microwaves can be used to deduce the density profile. The modification of the reflected pulses in the presence of density fluctuations is examined and can be understood based on considerations of Bragg resonance. A simple and effective profile-reconstruction algorithm using the zero-crossings of the reflected pulse and subsequent Abel inversion is demonstrated. The robustness of the profile reconstruction algorithm in the presence of a sufficiently small amplitude density perturbation ...
The number of reports concerning the chemical toxicology of metals which are released in the environment by natural as well as anthropogenic sources, have been increasing constantly. Lead, cadmium, and manganese have found a variety of uses in industry, craft, and agriculture owing to their physical and chemical properties. The environmental burden of heavy metals has been rising substantially by smelter emission in air and waste sewage in water. Further, organic compounds of lead and manganese used as antiknock substances in gasoline are emitted into the atmosphere by automobile exhaustion. Such environmental contamination of air, water, soil, and food is a serious threat to all living kinds. Although these metals are known to produce their toxic effects on a variety of body systems, much emphasis has been placed on their effects on the nervous system owing to apparent association of relatively low or ...
Background and Purpose: Total-body irradiation (TBI) is an important part of the conditioning regimen for hematopoietic stem cell transplantation (HSCT) in patients with hematologic malignancies. The results after treatment with various TBI regimes were compared, and dose-effect relationships for the endpoints relapse incidence, disease-free survival, treatment-related mortality, and overall survival were derived. The aim was to define requirements for an optimal treatment schedule with respect to leukemic cell kill and late normal-tissue morbidity. Material and Methods: A literature search was performed. Three randomized studies, four studies comparing results of two or three TBI regimens, and nine reports with results of one specific TBI regimen were identified. Biologicallyeffective doses (BEDs) were calculated. The results of the randomized studies and the studies comparing results of two or three TBI regimens were ...
Background and Purpose: Total-body irradiation (TBI) is an important part of the conditioning regimen for hematopoietic stem cell transplantation (HSCT) in patients with hematologic malignancies. The results after treatment with various TBI regimes were compared, and dose-effect relationships for the endpoints relapse incidence, disease-free survival, treatment-related mortality, and overall survival were derived. The aim was to define requirements for an optimal treatment schedule with respect to leukemic cell kill and late normal-tissue morbidity. Material and Methods: A literature search was performed. Three randomized studies, four studies comparing results of two or three TBI regimens, and nine reports with results of one specific TBI regimen were identified. Biologicallyeffective doses (BEDs) were calculated. The results of the randomized studies and the studies comparing results of two or three TBI regimens were ...
1. Contest rules The European Space Agency (ESA) is launching a public competition to find the most suitable names for its four Cluster II space weather satellites. The quartet, which are currently known as flight models 5, 6, 7 and 8, are scheduled for launch from Baikonur Space Centre in Kazakhstan in June and July 2000. Professor Roger Bonnet, ESA Director of Science Programme, announced the competition for the first time to the European Delegations on the occasion of the Science Programme Committee (SPC) meeting held in Paris on 21-22 February 2000. The competition is open to people of all the ESA member states (*). Each entry should include a set of FOUR names (places, people, or things from history, mythology, or fiction, but NOT living persons). Contestants should also describe in a few sentences why their chosen names would be appropriate for the four Cluster II satellites. The winners will be those which are considered most suitable and relevant for the Cluster II mission. ...
A large variety of microwave producing devices are used in contemporary naval communications and weapons systems. Public and scientific concern about potential biologicaleffects of microwave irradiation such as produced by these various devices requires documentations of such effects. Currently, the only well documented direct effect of microwaves is heating of the exposed organism. The present report is of a series of studies whose aim was to explore several microwave frequencies and their effect on performance and simultaneously to investigate the relationship to core heating in the exposed animals. Three difficult sized species of animals were used so that generalization to larger animals could be made. Rats, squirrel monkeys, and rhesus monkeys showed consistent effects of 60-minute exposures to microwaves when their body temperatures were increased at ...
The influence of low-level microwaves (2.45 GHz, CW, 2 and 5 mW.cm/sup -2/) was studied on various models of previsional animal psychopharmacology involving tests of motor activity, stereotypy, convulsions and hypothermia after a standard 30 min irradiation. The results obtained on 933 rodents allow to conclude that: (1) there is no interaction between microwaves and the studied convulsants and stimulants; (2) there is a possibility of potentialization of the behavioral effects of a tranquilizer; (3) there is a thermogenic effect of microwaves; (4) there is no change of the blood-brain barrier permeability. The demonstration of a thermal effect of microwaves during radiations lower than 10 mW.cm/sup -2/ the safety threshold admitted presently (a value below which the exposure duration comes under regulation) could explain the energetic nature of certain effects of microwaves up-to-now described as ...
This report is a survey of the English language literature of radiation biology between 1947 and 1987, for the purpose of compiling a literature base on the effects of radiation on animals, which have yielded results that can expand our knowledge about similar radiation effects on human beings. Articles were sought that reported exposure of adult mammals to external sources of ionizing radiation, having endpoints that included effects on the brain, the spinal cord, and behavior of the gastrointestinal, endocrine, and cardiovascular systems and the hematopoietic and immune systems. Effects of interest were those that occurred within the first 12 months after exposure. The survey does not include articles reporting chronic or long term delayed effects of radiation unless they provided insight into mechanisms of morphological and/or functional derangement. ...
The phenomena and effects of airblast, ground shock, thermal radiation, cratering and ejecta, and debris cloud and deposition from the eruption of Mt. St. Helens were compared to those that would result from a nuclear explosion to determine if phenomena or effects were analogous and thus might provide useful data for military nuclear weapon effects studies. It is concluded that the phenomena are not analogous. In particular, airblast destruction was caused by clouds of ash driven by subsonic winds, rather than by a supersonic shock wave that would be the damage mechanism of a nuclear explosion. Because of the lack of analogy between the eruption and nuclear explosion phenomena, it appears questionable that any of the effects are analogous; therefore, it is unlikely that anything more of military interest can be gained from studying the effects of the eruption. ...
High precision fundamental neutron physics experiments have been proposed for the intense pulsed spallation neutron beams at JSNS, LANSCE, and SNS to test the standard model and search for new physics. Certain systematic effects in some of these experiments have to be controlled at the few ppb level. The NPD Gamma experiment, a search for the small parity-violating {gamma}-ray asymmetry A{sub Y} in polarized cold neutron capture on parahydrogen, is one example. For the NPD Gamma experiment we developed a radio-frequency resonant spin rotator to reverse the neutron polarization in a 9.5 cm x 9.5 cm pulsed cold neutron beam with high efficiency over a broad cold neutron energy range. The effect of the spin reversal by the rotator on the neutron beam phase space is compared qualitatively to rf neutron spin flippers based on adiabatic fast passage. We discuss the design of the spin rotator and describe two types of ...
Radishes (Raphanus sativus L.) are members of the cruciferous vegetable family that contain many classes of biologically active phytochemicals. This study determined the phytochemical composition of the sprouts and mature taproots of 8 radish varieties. Radish sprouts contained significantly greater concentrations of glucosinolates (3.8-fold) and isothiocyanates (8.2-fold) than the mature radish taproot and also contained significantly greater concentrations of phenolics (on average 6.9-fold). The anthocyanin concentrations of the mature radish taproot were significantly greater than in the sprouts of red, pink, and purple varieties. The primary anthocyanidins present in the red and pink radish varieties were pelargonidin and delphinidin, while the primary anthocyanidin in the purple radish variety was cyanidin. Radish sprouts were between 9- and 59-fold more potent than the corresponding mature taproot at activating the antioxidant response element (ARE) in a ...
-Ecophysiological and floristic study of the lichen communities in .... Plasticity of the Lichen Catillaria corymbosa in Different Microhabitats of the ...
Volatile organic compounds (VOC) are an important group of pollutants with adverse effects on humans and the environment. Primary air pollution abatement measures aim at prevention or reduction of pollutant production in industrial production processes, e.g. by improved processes but also by other methods (closed cycle processes, different process materials, etc.). If these measures have been implemented and emissions are still too high, an off-air purification unit must be installed. Biological purification is the method of choice for low pollutant concentrations. Biological purification processes are based on the activity of microorganisms which are capable of biochemical oxidation of organic and some inorganic gaseous compounds into non-polluting or non-odorous compounds. These processes have the advantage that they work at ambient conditions and therefore remove relatively low pollutant concentrations at low investment ...
A rigorous solution for the spectrum of a quasioptical cylindrical cavity resonator with a randomly rough side boundary has been obtained. To accomplish this task, we have developed a method for the separation of variables in a wave equation, which enables one, in principle, to rigorously examine any limiting case-from negligibly weak to arbitrarily strong disorder at the resonator boundary. It is shown that the effect of disorder-induced scattering can be properly described in terms of two geometric potentials, specifically, the "amplitude" and the "gradient" potentials, which appear in wave equations in the course of conformal smoothing of the resonator boundaries. The scattering resulting from the gradient potential appears to be dominant, and its impact on the whole spectrum is governed by the unique sharpness parameter ?, the mean tangent of the asperity slope. As opposed to the resonator with bulk disorder, the ...
A numerical method for studying the flow field of an under-expanded axis-symmetric jet created by a converging-diverging nozzle and impinging on a flat plate is presented. The calculation domain of interest is a region that contains all the features of the jet that leaves the nozzle and impinges onto the plate. Axial symmetry of the domain allows a reduced 2-dimensional model to be used. FLUENT software is utilized to solve the continuity, momentum and energy equations using a coupled implicit scheme. The ideal-gas law is used to determine the gas density along with a k-#epsilon# turbulence model with a special modification to account for compressibility effects. In addition, the temperature dependency of viscosity has been taken into consideration. A number of different modeling techniques are investigated including different approximations to account for the flow inside the nozzle. Performance of non-equilibrium wall functions for near-wall turbulence treatment ...
The isostructural #gamma#-#alpha# phase transition of Ce which occurs at 8 kbar has been studied by means of fully self-consistent (non-muffin-tin potential) linearized-augmented-plane-wave energy band calculations carried out for five different values of the lattice constant. In contradiction to the 4f electron promotional model of the transition, the results yield essentially one 4f electron to be occupied in each phase but with the 4f wave function somewhat less localized, and therefore more bandlike, in the ''collapsed'' #alpha# phase. A singly occupied 4f state is shown to be consistent with the available experimental data. These results strongly support the picture of a 4f localized bold-arrow-left-right itinerant transition at the #gamma#-#alpha# transition and conflict with the promotional model in which some fraction of 4f electrons are transferred to the sd conduction bands. The weaker bonding of the 4f electrons, compared to that of ...
We apply our previously developed first-principles nonlocal pseudopotentials (obtained for all atoms of rows 1--5 in the Periodic Table) to study self-consistently the electronic structure of Si and Ge and the transition metals Mo and W. For Si and Ge we find that the first-principles pseudopotentials yield valence-band states in good agreement with the empirically adjusted pseudopotential and photoemission data, whereas the low conduction-band states appear to be consistently lower in energy due apparently to incomplete cancellation of the self-interaction effects. The calculated x-ray scattering factors (obtained by core orthogonalization of the pseudo-wave-functions) are in excellent agreement with experiment. The self-consistent valence charge density shows a distinct elongation of the covalent bond along the internuclear axis, in good agreement with the experimentally synthesized density. The systematic deviations of the empirical ...
The results of experiments with a short period (9.6 mm) wiggler sheet electron beam (1.0 mm x 2.0 cm) millimeter-wave free electron laser (FEL) amplifier are presented. This FEL amplifier utilized a strong wiggler field for sheet beam confinement in the narrow beam dimension and an offset-pole side-focusing technique for the wide dimension beam confinement. The beam analysis herein includes finite emittance and space-charge effects. High-current beam propagation was achieved as a result of extensive analytical studies and experimental optimization. A design optimization resulted in a low sensitivity to structure errors and beam velocity spread, as well as a low required beam energy. A maximum gain of 24 dB was achieved with a 1-kW injected signal power at 86 GHz, a 450-kV beam voltage, 17-A beam current, 3.8-kG wiggler magnetic field, and a 74-period wiggler length. The maximum gain with a one-watt injected millimeter-wave ...
Climates at regional scale are strongly dependent on the interaction between atmosphere and its lower boundary, the oceans and the land surface mosaic. Land surfaces influence climate through their albedo, and the aerodynamic roughness, the processes of the biosphere and many soil hydrological properties; all these factors vary considerably geographically. Land surfaces receive a certain portion of the solar irradiance depending on the cloudiness, atmospheric transparency and surface albedo. Short-wave solar irradiance is the source of the heat energy exchange at the earth`s surface and also regulates many biological processes, e.g. photosynthesis. Methods for estimating solar irradiance, atmospheric transparency and surface albedo were reviewed during the course of this project. The solar energy at earth`s surface is consumed for heating the soil and the lower atmosphere. Where moisture is available, evaporation is one of the key components of ...
We have performed self-consistent (SC) band structure calculations for the A15 compounds V_3X and Nb_3X, X = Al, Ga, Si, Ge, and Sn, using the augmented-plane-wave (APW) method. Relativistic effects (except the spin-orbit interaction) have been included in each SC cycle, along with corrections to the usual muffin-tin approximation. The latter apply the APW wave functions outside of the muffin-tin spheres to compute the interstitial charge densities and potentials. The resulting interstitial potential has full cubic symmetry (no spherical averaging), although a spherically averaged muffin-tin form is retained inside the spheres. The final SC potentials were used to generate energies and wave functions on a cubic mesh of 35 k points in 1/48th of the Brillouin zone. These results were interpolated onto a finer mesh of 969 k points using a symmetrized Fourier method; the densities of states (DOS), N (E), ...
We present a HST/STIS spectroscopic and optical/radio imaging study of the Seyfert NGC 2110 aiming to measure the dynamics and understand the nature of the nuclear outflow in the galaxy. Previous HST studies have revealed the presence of a linear structure in the Narrow-Line Region (NLR) aligned with the radio jet. We show that this structure is strongly accelerated, probably by the jet, but is unlikely to be entrained in the jet flow. The ionisation properties of this structure are consistent with photoionisation of dusty, dense gas by the active nucleus. We present a plausible geometrical model for the NLR, bringing together various components of the nuclear environment of the galaxy. We highlight the importance of the circum-nuclear disc in determining the appearance of the emission line gas and the morphology of the jet. From the dynamics of the emission line gas, we place constraints on the accelerating mechanism of the outflow and discuss ...
The Air Force`s Armstrong Laboratory at Tyndall Air Force Base, Florida, has supported the research and development of Radio Frequency Soil Decontamination. Radio frequency soil decontamination is essentially a heat-assisted soil vapor extraction process. Site S-1 at Kelly Air Force Base, San Antonio, Texas, was selected for the demonstration of two patented techniques. The site is a former sump that collected spills and surface run-off from a waste petroleum, oils, and lubricants and solvent storage and transfer area. In 1993, a technique developed by the IIT Research Institute using an array of electrodes placed in the soil was demonstrated. In 1994, a technique developed by KAI Technologies, Inc. using a single applicator placed in a vertical borehole was demonstrated. Approximately 120 tons of soil were heated during each demonstration to a temperature of about 150 degrees Celsius.
Over the past three decades, rising competition from television and other new media prompted the FCC to ease the responsibilities of radio stations to maintain extensive records of issues programming, while retaining the responsibility of stations to provide ready public access to records. This study investigated the availability of Issues-Programs Lists in nearly 100 Missouri radio station Public Files. One in five randomly sampled stations failed to produce access to Lists upon demand as required under federal law. Noncompliance themes include: Inability to access Public Files within 20 minutes of face-to-face requests; station personnel with limited or no knowledge of Files; denial of access to Files and Lists (i.e., verbal refusals, locked studio doors); and incomplete Files. The rate ...
We present evidence in favour of a link between the luminosity radiatively dissipated in the central engine of radio-loud Active Galactic Nuclei and the kinetic power in their jets. This piece of evidence is based on the relation we find between the luminosity in broad emission lines and the kinetic power in pc-scale radio jets, for a sample of radio-loud quasars for which suitable data are available in the literature. We find that the ionizing luminosity and the kinetic one are of the same order of magnitude, suggesting that the processes responsible for them are somehow related. A strong magnetic field in equipartition with the radiation field could be responsible for regulating both processes. BL Lac objects seem to follow a similar behaviour, but with comparatively fainter broad line emission.
This paper reports extensive new optical and radio observations of NGC 5728, emphasizing the central regions. Deep photographs revealing detail in the faint spiral arms are briefly discussed. Broad-band UBV CCD images obtained to examine the colors of the stellar populations that comprise the bar and central ring are presented. The velocity field and emission maps obtained from imaging spectroscopic measurements in the H-alpha emission line are discussed. Conventional long-slit spectra covering the ionized gas in the nuclear region are described. Detailed maps of the radio emission in the central regions of NGC 5728 are presented. These combined data provide considerable evidence for the inflow of gas into the nuclear region, in response to the nonaxisymmetric gravitational potential of the bar. The possible relation of this phenomenon to the Seyfert nature of NGC 5728 is also considered. 48 references.
Cyclic spectral analysis is a signal processing technique designed to deal with stochastic signals whose statistics vary periodically with time. Pulsar radio emission is a textbook example of this signal class, known as cyclostationary signals. In this paper, we discuss the application of cyclic spectral analysis methods to pulsar data, and compare the results with the traditional filterbank approaches used for almost all pulsar observations to date. In contrast to standard methods, the cyclic spectrum preserves phase information of the radio signal. This feature allows us to determine the impulse response of the interstellar medium and the intrinsic, unscattered pulse profile directly from a single observation. We illustrate these new analysis techniques using real data from an observation of the millisecond pulsar B1937+21.
In the positive column of a neon glow discharge, two different types of ionization waves occur simultaneously. The low-dimensional chaos arising from the nonlinear interaction between the two waves is controlled by a continuous feedback technique. The control strategy is derived from the time-delayed autosynchronization method. Two spatially displaced points of observation are used to obtain the control information, using the propagation characteristics of the chaotic wave.