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Sample records for radiated noise due

  1. Stochastic memory: Memory enhancement due to noise

    Stotland, Alexander; di Ventra, Massimiliano

    2012-01-01

    There are certain classes of resistors, capacitors, and inductors that, when subject to a periodic input of appropriate frequency, develop hysteresis loops in their characteristic response. Here we show that the hysteresis of such memory elements can also be induced by white noise of appropriate intensity even at very low frequencies of the external driving field. We illustrate this phenomenon using a physical model of memory resistor realized by TiO2 thin films sandwiched between metallic electrodes and discuss under which conditions this effect can be observed experimentally. We also discuss its implications on existing memory systems described in the literature and the role of colored noise.

  2. Loading Effect on Tire Noise Radiation

    Cao, Rui; Bolton, J Stuart

    2016-01-01

    Noise radiated by tires is a prominent noise pollution source and it is affected by many different parameters. Here, the effect of static load on tire noise radiation in a laboratory environment was investigated. The measurement was conducted by using the Tire Pavement Testing Apparatus (TPTA), on which a loaded tire can be run at speeds up to 50 km/hr; the tire noise was measured using a nearfield microphone method. The tire loading was varied from 500 to 900 pounds, and several different co...

  3. Artificial noise due to DC electric trains

    Senanayake, W.E.

    1987-08-01

    The current distribution in a DC railway and the resulting magnetic effects have been modelled using the parameters of the DC railway networks in Italy. The results show that the magnetic perturbations are substantially high in the vicinity of electrified railway lines. The order of magnitude of the induced field can be as significant as ∼ 40nT at a distance of ≅ 2km from the railway line indicating that geophysical techniques that employ natural magnetic anomalies can be badly effected, within this range. The magnetic effects rapidly decay with increasing distance, but the noise level could be significant even at a range of ∼ 10km. Also, these induced anomalies vary significantly with the conductivity of the ground. When the conductivity is high it is possible that the railway currents dispersed through the ground interact with those induced in the earth, causing a severe disruption to the telluric measurements. (author). 11 refs, 10 figs, 1 tab

  4. A new approach to modelling radiation noise in CCD's

    Chugg, A.; Hopkinson, G.

    1998-01-01

    The energy depositions reported by Monte Carlo electron-photon irradiation transport codes are subject to a random error due to the finite number of particle histories used to generate the results. These statistical variations, normally a nuisance, may also be identified with the real radiation noise effects experienced by CCD pixels in persistent radiation environments. This paper explores the practicability of such radiation noise modelling by applying the ACCEPT code from the ITS suite to the case of a shielded CCD exposed to an electron flux. The results are compared with those obtained in a subsequent electron irradiation of the CCD by a Van de Graaff accelerator

  5. Active microphonic noise cancellation in radiation detectors

    Zimmermann, Sergio

    2013-01-01

    A new adaptive filtering technique to reduce microphonic noise in radiation detectors is presented. The technique is based on system identification that actively cancels the microphonic noise. A sensor is used to measures mechanical disturbances that cause vibration on the detector assembly, and the digital adaptive filtering estimates the impact of these disturbances on the microphonic noise. The noise then can be subtracted from the actual detector measurement. In this paper the technique is presented and simulations are used to support this approach. -- Highlights: •A sensor is used to measures mechanical disturbances that cause vibration on the detector assembly. •Digital adaptive filtering estimates the impact of these disturbances on the microphonic noise. •The noise is then subtracted from the actual detector measurement. •We use simulations to demonstrate the performance of this approach. •After cancellation, we recover most of the original energy resolution

  6. Conducted and radiated noise in detection devices

    Moisa, D.

    2001-01-01

    Conducted and radiated noise is an external noise which affects the quality of the signals of the detectors. An external noise can be reduced, usually, by shielding. This was the situation with 'older fashion' devices which uses boxes and coaxial cables. As the devices becomes more complex, the shielding of the detectors is more and more difficult and the transmission lines evolves from coaxial cables to twisted pair cables which are no more shielded. In such situation, the conducted and radiated noise (C and R noise) becomes important. Due to complexity of a real detector, the main work is based on experiments with components and simulations of some specific problems, associated with CDC detector. The first experiment was done to understand how the C and R noise is propagated. The emission device was a set of coils (between 3 and 5 turns with diameter from 10 to 50 mm) feed by an 74S140 driver. A pulse of about 8 ns width was generated. A coil of reception of about the same physical characteristics was used to see the emitted pulse. When the two coils are separated by about 80 cm, the receiver generated no signal. But, if along the two coils, a conductive material is introduced (a wire for instance), the receiver senses a signal. This signal is not changed too much if the wire is or not connected to ground. The explanation is simple: the pulse in the emitting coil produces an EM pulse which spreads in space. If a conductive material is around, the EM energy is received by that conductor and it is propagated at tens of meters with small attenuation. When this energy reaches the end of the conductor, it is radiated in space. If some other conductors are around, the energy is received and propagated by that conductors. This experiment was done for about 20 kinds of conductors (different coax cables, twisted-pair ribbons, power cables, metallic bars) and with many coils (different diameters and numbers of turns). It was measured the pk-to-pk level, decay constant and

  7. Secondary osteoporosis due to radiation

    Hamada, Katsuyuki; Kihana, Toshimasa; Inoue, Yasuhiro; Takeda, Yasunari; Matsuura, Shumpei; Kataoka, Masaaki; Hamamoto, Ken (Ehime Univ., Shigenobu (Japan). School of Medicine)

    1991-09-01

    Bone mineral density (BMD) of the 3rd lumber vertebra (L3) and the 5th lumber vertebra (L5) were measured by quantitative computed tomography (QCT). BMD of L3 and L5 in 139 normal control cases decreased linearly with age (L3: Y= 317.32 - 3.283X, L5: Y= 314.35 - 2.9056X). Ratio of the BMD of L5 to L3 (L5/L3 ratio, %) was constant in the value of 106.03{+-}12.84% before 50 years old and increased linearly after 50 years old (Y= 21.624 + 1.7187X). In 30 radiated cases, BMD of the radiated L5 ws decreased after 20 Gy of radiation and reached 47.44{+-}18.74% of the preradiated value after 50 Gy of radiation. L5/L3 ratio was also decreased after 20 Gy of radiation and reached 48.34{+-}19.33% of pre-radiated value after 50 Gy radiation. BMD of L5 and L5/L3 ratio after 50 Gy of radiation were decreased linearly with age (L5: Y= 107.44 - 0.9686X, L5/L3 ratio: Y= 106.98 - 0.9472X). Quality of life (performance status: PS, lumbago score) after radiation correlated significantly with age, body weight, BMD of L3 before radiation, BMD of L5 after radiation. PS and lumbago score were increased significantly in cases of more than 75 years old, less than 50 kg, less than 100 mg/cm{sup 3} of BMD of L3 before radiation and less than 40 mg/cm{sup 3} of BMD of L5 after radiation. Quality of life after radiation was improved by treatment of alfacalcidol (PS: 3.0{+-}0.61 to 1.2{+-}0.47, lumbago score: 15.4{+-}4.08 to 4.2{+-}1.17). In conclusion, it should be said that pelvic radiation for gynecologic malignancy may disturb the bone metabolism and quality of life in the early phase after radiation, especially in the aged patients and that quality of life could be improved by treatment of alfacalcidol. (author).

  8. Aplastic anemia due to radiation

    Sakai, Kunio; Saito, Akira

    1978-01-01

    The relationship between radiation exposure and aplastic anemia, clarified previously, is discussed. When persons such as radiological technicians receive whole-body irradiation in rather large doses, it is possible that aplastic anemia will result later on. However, this is difficult to determine because the irradiated region is limited despite large doses of radiation. (Bell, E.)

  9. Characterising risk - aggregated metrics: radiation and noise

    Passchier, W.

    1998-01-01

    The characterisation of risk is an important phase in the risk assessment - risk management process. From the multitude of risk attributes a few have to be selected to obtain a risk characteristic or profile that is useful for risk management decisions and implementation of protective measures. One way to reduce the number of attributes is aggregation. In the field of radiation protection such an aggregated metric is firmly established: effective dose. For protection against environmental noise the Health Council of the Netherlands recently proposed a set of aggregated metrics for noise annoyance and sleep disturbance. The presentation will discuss similarities and differences between these two metrics and practical limitations. The effective dose has proven its usefulness in designing radiation protection measures, which are related to the level of risk associated with the radiation practice in question, given that implicit judgements on radiation induced health effects are accepted. However, as the metric does not take into account the nature of radiation practice, it is less useful in policy discussions on the benefits and harm of radiation practices. With respect to the noise exposure metric, only one effect is targeted (annoyance), and the differences between sources are explicitly taken into account. This should make the metric useful in policy discussions with respect to physical planning and siting problems. The metric proposed has only significance on a population level, and can not be used as a predictor for individual risk. (author)

  10. Does noise from wind turbines change due to age?

    Andersen, B.; Jakobsen, J.

    1995-06-01

    It has been discussed whether the noise from a wind turbine increases due to wear of the mechanical parts or to pollution of the rotor blades. If this is so it should be taken into consideration at the design stage. The noise from wind turbines that had been measured several years before was measured again, and results were compared. A number of modifications of the same wind turbine was made throughout a period of two years during which noise was measured several times. No evidence that noise increases in accordance with the age of the windmill was found. A 75 kW wind turbine seems to have an unchanged A-weighted source strength L WA after a period of 6 years. The level of the tones in the noise from the large generator engaged had increased slightly. The noise from operation of the small generator showed a pronounced increase of one tone (approximately 10 dB), while two other tones were largely unchanged. In the case of periodic measurements of the noise from a 300 kW wind turbine, the gearbox tone noise was found to change markedly, without any obvious pattern. The large, apparently random, fluctuations mask any tendency towards changes of the tone level with time. Repeated measurements of four identical 100 kW wind turbines, show a general tendency towards an increase of the A-weighted source strength (L WA ). The increase of L WA between 1 and 2.7 dB, was found mainly in the frequency range 800 Hz to 3 kHz. The level of the third octave band, which includes a weak gearbox tone (315 Hz), seemed unchanged. Other measurements indicate a constant level of noise during the first three years of operation. (AB)

  11. Plasmaspheric noise radiation during geomagnetic storms

    Larkina, V.I.; Likhter, Ya.I.

    1981-01-01

    Variations of plasmospheric background radiations during geomagnetic storms of different intensity are investigated. Used are results of ELF and VLF radiation measurements as well as electron fluxes of energies Esub(e)>40 keV carried out by Intercosmos 3 and Intercosmos 5 satellites. Dependences of radiation amplitude variations at 1.6 and 25 kHz frequencies on L shell for various geomagnetic activity in the day-time as well as data on variations of quasicaptured electron fluxes at Esub(e)>40 keV, are given. It is shown that experimental data agree with the existing theories of plasmospheric noise excitation. It is concluded that the plasmospheric noise excitation area Lsub(max) is always in the region of gap between radiation belts and inner slope of external radiation belt during magnetic storms. During magnetic storms Lsub(max) area moves simultaneously with the area, where particle flux of the external radiation belt is the most intensive [ru

  12. Objective and subjective rating of tonal noise radiated from UK wind farms

    1996-01-01

    The radiation of noise to the environment is currently a major issue with regard to U.K. wind farm developments. The reason for this concern is not that wind turbines are unduly noisy, but rather because wind farms are often located in rural areas where background noise levels can fall very low. The fact that background noise levels fall so low in these areas means that the permissible noise radiation from wind farms must also be kept similarly low if nuisance to local residents is to be avoided. However, ensuring that the overall noise level of the wind farm does not exceed the pre-existing background noise level by more than a set amount is not the whole story. Noise radiated from wind turbines can exhibit characteristics that set it apart from the natural background noises typically found in quiet rural areas, where ''natural'' background noises might include the sound of the wind blowing through trees, or the sound of running water. One of the acoustic characteristics that can be attributed to some wind turbines is the radiation of tonal noise from mechanical plant located in the nacelles. It is well accepted that tonal components in otherwise broad band, or ''characterless'', noise, can increase the subjective perception of that noise. Account for increased annoyance due to tones is found in both of the British Standards which relate to environmental noise; BS4142 and BS7445. (UK)

  13. Decoherence in qubits due to low-frequency noise

    Bergli, J; Galperin, Y M; Altshuler, B L

    2009-01-01

    The efficiency of the future devices for quantum information processing will be limited mostly by the finite decoherence rates of the qubits. Recently, substantial progress was achieved in enhancing the time within which a solid-state qubit demonstrates coherent dynamics. This progress is based mostly on a successful isolation of the qubits from external decoherence sources. Under these conditions, the material-inherent sources of noise start to play a crucial role. In most cases, the noise that the quantum device demonstrates has a 1/f spectrum. This suggests that the environment that destroys the phase coherence of the qubit can be thought of as a system of two-state fluctuators, which experience random hops between their states. In this short review, the current state of the theory of the decoherence due to the qubit interaction with the fluctuators is discussed. The effect of such an environment on two different protocols of the qubit manipulations, free induction and echo signal, is described. It turns out that in many important cases the noise produced by the fluctuators is non-Gaussian. Consequently, the results of the interaction of the qubit with the fluctuators are not determined by the pair correlation function alone. We describe the effect of the fluctuators using the so-called spin-fluctuator model. Being quite realistic, this model allows one to exactly evaluate the qubit dynamics in the presence of one fluctuator. This solution is found, and its features, including non-Gaussian effects, are analyzed in detail. We extend this consideration to systems of large numbers of fluctuators, which interact with the qubit and lead to the 1/f noise. We discuss existing experiments on the Josephson qubit manipulation and try to identify non-Gaussian behavior.

  14. Self-reported sleep disturbances due to railway noise: exposure-response relationships for nighttime equivalent and maximum noise levels.

    Aasvang, Gunn Marit; Moum, Torbjorn; Engdahl, Bo

    2008-07-01

    The objective of the present survey was to study self-reported sleep disturbances due to railway noise with respect to nighttime equivalent noise level (L(p,A,eq,night)) and maximum noise level (L(p,A,max)). A sample of 1349 people in and around Oslo in Norway exposed to railway noise was studied in a cross-sectional survey to obtain data on sleep disturbances, sleep problems due to noise, and personal characteristics including noise sensitivity. Individual noise exposure levels were determined outside of the bedroom facade, the most-exposed facade, and inside the respondents' bedrooms. The exposure-response relationships were analyzed by using logistic regression models, controlling for possible modifying factors including the number of noise events (train pass-by frequency). L(p,A,eq,night) and L(p,A,max) were significantly correlated, and the proportion of reported noise-induced sleep problems increased as both L(p,A,eq,night) and L(p,A,max) increased. Noise sensitivity, type of bedroom window, and pass-by frequency were significant factors affecting noise-induced sleep disturbances, in addition to the noise exposure level. Because about half of the study population did not use a bedroom at the most-exposed side of the house, the exposure-response curve obtained by using noise levels for the most-exposed facade underestimated noise-induced sleep disturbance for those who actually have their bedroom at the most-exposed facade.

  15. Numerical study of jet noise radiated by turbulent coherent structures

    Bastin, F.

    1995-08-01

    a numerical approach of jet mixing noise prediction is presented, based on the assumption that the radiated sound field is essentially due to large-scale coherent turbulent structures. A semi-deterministic turbulence modelling is used to obtain the flow coherent fluctuations. This model is derived from the k-{epsilon} model and validated on the 2-D compressible shear layer case. Three plane jets at Mach 0.5, 1.33 and 2 are calculated. The semi-deterministic modelling yields a realistic unsteady representation of plane jets but not appropriate for axisymmetric jet computations. Lighthill`s analogy is used to estimate the noise radiated by the flow. Three integral formulations of the theory are compared and the most suitable one is expressed in space-time Fourier space. This formulation is associated to a geometrical interpretation of acoustic computations in (k, {omega}) plane. The only contribution of coherent structures cannot account for the high-frequency radiation of a subsonic jet and thus, the initial assumption is not verified in the subsonic range. The interpretation of Lighthill`s analogy in (k, {omega}) plane allows to conclude that the missing high-frequency components are due to the inner structure of the coherent motion. For supersonic jets, full acoustic spectra are obtained, at least in the forward arc where the dominant radiation is emitted. For the fastest jet (M = 2), no Mach waves are observed, which may be explained by a ratio of the structures convection velocity to the jet exit velocity lower in plane than in circular jets. This point is confirmed by instability theory calculations. Large eddy simulations (LES) were performed for subsonic jets. Data obtained in the plane jet case show that this technique allows only a slight improvement of acoustic results. To obtain a satisfactory high-frequency radiation, very fine grids should be considered, and the 2-D approximation could not be justified anymore. (Abstract Truncated)

  16. CONTROLLING RISK DUE TO NOISE ON FERRY BOAT

    Aleksandar Nikolic

    2013-07-01

    Full Text Available Environmental and occupational noise is common nuisance that affects the health of employees. Performed health checks of employees engaged by Company “Pomorski Saobraćaj” showed that 5% of examined sailors had hearing loss. The results were a trigger for starting experiment on noise risk assessment with objective to discover possibilities of noise pollution presence, precise significant noise sources and describe solutions for eliminating negative effects. Several measurements on five positions were performed on ferry boat “KAMENARI”, according to EC Physical Agents Directive and Merchant Shipping and Fishing Vessels Regulations 2007. Noise on selected positions exceeded the limit for about 1-5dB. Noise exposure level was 84.5dB. Diesel engine, exhaust system and structural noise were main sources of excessive noise. Experiment shows noise presence as nuisance that affects sailors. Noise presents a serious threat for sailor’s health. It interferes with crew communication and jeopardizes navigation safety. Technical measures, crew health checks and noise monitoring could prevent all negative effects.

  17. Radiation risk due to occupational exposure

    Kargbo, A.A

    2012-04-01

    Exposure to ionizing radiation occurs in many occupations. Workers can be exposed to both natural and artificial sources of radiation. Any exposure to ionizing radiation incurs some risk, either to the individual or to the individual's progeny. This dissertation investigated the radiation risk due to occupational exposure in industrial radiography. Analysis of the reported risk estimates to occupational exposure contained in the UNSCEAR report of 2008 in industrial radiography practice was done. The causes of accidents in industrial radiography include: Lack of or inadequate regulatory control, inadequate training, failure to follow operational procedures, human error, equipment malfunction or defect, inadequate maintenance and wilful violation have been identified as primary causes of accidents. To minimise radiation risks in industrial radiography exposure devices and facilities should be designed such that there is intrinsic safety and operational safety ensured by establishing a quality assurance programme, safety culture fostered and maintained among all workers, industrial radiography is performed in compliance with approved local rules, workers engaged have appropriate qualifications and training, available safe operational procedures are followed, a means is provided for detecting incidents and accidents and an analysis of the causes and lessons learned. (author)

  18. Pollutant emission and noise radiation from open and impinging inverse diffusion flames

    Choy, Y.S.; Zhen, H.S.; Leung, C.W.; Li, H.B.

    2012-01-01

    Highlights: ► The effect of burner geometry (d air and S) on inverse diffusion flames is studied. ► With fixed air/fuel supplies, a smaller d air curtails NO x emission but augments noise radiation. ► With fixed air/fuel supplies, a larger S reduces NO x emission but increases noise radiation. ► Both NO x emission and noise radiation are maximum under stoichiometric combustion. ► Impinging flames are nosier than corresponding open flames due to the mirror effect of the plate. -- Abstract: This paper reports an experimental investigation of the pollutant emission and noise radiation characteristics of both open and impinging inverse diffusion flames (IDFs), produced by five burners of different air port diameter (d air = 5, 6 and 6.84 mm) and air-to-fuel spacing (S = 8, 11.5 and 15 mm). The effects of d air , S, overall equivalence ratio φ and nozzle-to-plate spacing H on the pollutant emissions of CO and NO x and the noise radiation are examined. The results show that at fixed air flow rate, a smaller d air curtails NO x emission but augments noise radiation, indicative of a role played by turbulence, which tends to decrease pollutant emission and increase noise radiation. A larger S reduces NO x emission but increases noise radiation, indicating that different flame zones may be responsible for pollutant emission and noise radiation. When the IDF is under stoichiometric φ = 1.6, both the NO x emission and noise radiation are highest, as a result of maximum heat release rate. A comparison of EINO x for the open and impinging IDFs shows that the impinging IDFs emit more NO x probably due to the absence of NO reburning. The impinging IDFs have higher noise radiation than the corresponding open IDFs. A higher level of noise radiation from the impinging IDFs is observed as the target plate is brought closer to the burner.

  19. Sleep disturbance due to noise: Current issues and future research

    Ken Hume

    2010-01-01

    Full Text Available There is growing interest in carrying out further research to understand and reduce the impact of aircraft noise on airport neighborhood in anticipation of the projected substantial increase in global aviation. Soundscapes provide new analytical methods and a broader, more comprehensive appreciation of the aural environment, which may have a useful role in understanding noise-induced sleep disturbance and annoyance. Current noise metrics like Leq do not provide a common language to report noise environment to residents, which is a key obstacle to effective noise management and acceptance. Non-auditory effects complicate the production of consistent dose-response functions for aircraft noise affecting sleep and annoyance. There are various end-points that can be chosen to assess the degree of sleep disturbance, which has detracted from the clarity of results that has been communicated to wider audiences. The World Health Organization (WHO-Europe has produced Night Noise Guidelines for Europe, which act as a clear guide for airports and planners to work towards. Methodological inadequacies and the need for simpler techniques to record sleep will be considered with the exciting potential to greatly increase cost-effective field data acquisition, which is needed for large scale epidemiological studies

  20. Propeller rotation noise due to torque and thrust

    Deming, Arthur F

    1940-01-01

    Sound pressure of the first four harmonics of rotation from a full-scale two-blade propeller were measured and are compared with values calculated from theory. The comparison is made (1) for the space distribution with constant tip speed and (2) for fixed space angles with variable tip speed. A relation for rotation noise from an element of radius developed by Gutin is given showing the effect of number of blades on the rotation noise.

  1. External exposure due to natural radiation (KINKI)

    1978-01-01

    A field survey of exposure rates due to natural radiation has been conducted throughout the Kinki district of Japan during both September and October 1973. In each location, measurements of exposures at one to fifteen sites, one of where contained 5 stations at least, were made. A total of 143 sites were measured. Observations were made using a spherical ionization chamber and several scintillation surveymeters. The spherical plastic ionization chamber of which inner diameter and wall thickness are 200 mm and 3 mm (acrylate) respectively has adequate sensitivity for field survey. The chamber was used as a standard of apparatus, but it is difficult to use the apparatus in all locations only by the apparatus, so that a surveymeter with a NaI(Tl) 1''phi x 1'' scintillator was used for regular measurements. Two types of surveymeters, the one with a 2''phi x 2'' NaI(Tl) scintillator and the other with a 3''phi x 3'' NaI(Tl) scintillator, were used as auxiliary devices. Both the chamber and the surveymeter were used in 20 sites and their readings were compared for drawing a relationship between them. Practically the direct reading of the surveymeter were reduced into the corresponding value of the plastic chamber through the relationship of linear proportion. Systematic error at calibration ( 60 Co) and reading error (rodoh) of the plastic chamber were within +-6% (maximum over all error) and within +-3.5% (standard error for 6μ R/hr) respectively. Reading error of the surveymeter is about +-3% (standard error for 6μ R/hr). Measurements in open bare field were made at one meter above the ground and outdoor gamma-rays exposure rates (μ R/hr) were due to cosmic rays as well as terrestrial radiation, as it may be considered that the contribution of fallout due to artificial origin was very small. (J.P.N.)

  2. Selective modulation of nociceptive processing due to noise distraction.

    Boyle, Yvonne; El-Deredy, Wael; Martínez Montes, Eduardo; Bentley, Deborah E; Jones, Anthony K P

    2008-09-15

    This study investigates the effects of noise distraction on the different components and sources of laser-evoked potentials (LEPs) whilst attending to either the spatial component (localisation performance task) or the affective component (unpleasantness rating task) of pain. LEPs elicited by CO2 laser stimulation of the right forearm were recorded from 64 electrodes in 18 consenting healthy volunteers. Subjects reported either pain location or unpleasantness, in the presence and absence of distraction by continuous 85 dBa white noise. Distributed sources of the LEP peaks were identified using Low Resolution Electromagnetic Tomography (LORETA). Pain unpleasantness ratings and P2 (430 ms) peak amplitude were significantly reduced by distraction during the unpleasantness task, whereas the localisation ability and the corresponding N1/N2 (310 ms) peak amplitude remained unchanged. Noise distraction (at 310 ms) reduced activation in the anterior cingulate cortex (ACC) and precuneus during attention to localisation and unpleasantness, respectively. This suggests a complimentary role for these two areas in the control of attention to pain. In contrast, activation of the occipital pole and SII were enhanced by noise during the localisation and unpleasantness task, respectively, suggesting that the presence of noise was associated with increased spatial attentional load. This study has shown selective modulation of affective pain processing by noise distraction, indicated by a reduction in the unpleasantness ratings and P2 peak amplitude and associated activity within the medial pain system. These results show that processing of the affective component of pain can be differentially modulated by top-down processes, providing a potential mechanism for therapeutic intervention.

  3. Passive noise control by enhancing aeroacoustic interference due to structural discontinuities in close proximity

    Leung, R. C. K.; So, R. M. C.; Tang, S. K.; Wang, X. Q.

    2011-07-01

    In-duct devices are commonly installed in flow ducts for various flow management purposes. The structural construction of these devices indispensably creates disruption to smooth flow through duct passages so they exist as structural discontinuities in duct flow. The presence of these discontinuities provides additional possibility of noise generation. In real practice, in-duct devices do not exist alone in any duct system. Even though each in-duct device would generate its own noise, it might be possible that these devices could be properly arranged so as to strengthen the interference between individual noise; thus giving rise to an overall reduction of noise radiation in the in-duct far field. This concept of passive noise control is investigated by considering different configurations of two structural discontinuities of simple form (i.e., a cavity) in tandem in an unconfined flow and in opposing setting within a flow duct. It is known that noise generated by a cavity in unconfined domain (unconfined cavity) is strongly dependent on flow-resonant behavior within the cavity so the interference it produces is merely aeroacoustic. The objective of the present study is to verify the concept of passive noise reduction through enhancement of aeroacoustic interference due to two cavities by considering laminar flow only. A two-dimensional approach is adopted for the direct aeroacoustic calculations using a direct numerical simulation (DNS) technique. The position and geometries of the cavities and the Mach number are varied; the resultant aeroacoustic behavior and acoustic power are calculated. The numerical results are compared with a single cavity case to highlight the effect of introducing additional cavities to the aeroacoustic problem. Resonant flow oscillations occur when two unconfined cavities are very close and the associated acoustic field is very intense with no noise reduction possible. However, for duct aeroacoustics, it is found that a 7.9 db reduction

  4. Sound quality prediction for engine-radiated noise

    Liu, Hai; Zhang, Junhong; Guo, Peng; Bi, Fengrong; Yu, Hanzhengnan; Ni, Guangjian

    2015-05-01

    Diesel engine-radiated noise quality prediction is an important topic because engine noise has a significant impact on the overall vehicle noise. Sound quality prediction is based on subjective and objective evaluation of engine noise. The integrated satisfaction index (ISI) is proposed as a criterion for differentiate noise quality in the subjective evaluation, and five psychoacoustic parameters are selected for characterizing and analyzing the noise quality of the diesel engine objectively. The combination of support vector machines (SVM) and genetic algorithm (GA) is proposed in order to establish a model for predicting the diesel engine-radiated noise quality for all operation conditions. The performance of the GA-SVM model is compared with the BP neural network model, and the results show that the mean relative error of the GA-SVM model is smaller than the BP neural network model. The importance rank of the sound quality metrics to the ISI is indicated by the non-parametric correlation analysis. This study suggests that the GA-SVM model is very useful for accurately predicting the diesel engine-radiated noise quality.

  5. Noise Radiation Of A Strongly Pulsating Tailpipe Exhaust

    Peizi, Li; Genhua, Dai; Zhichi, Zhu

    1993-11-01

    The method of characteristics is used to solve the problem of the propagation of a strongly pulsating flow in an exhaust system tailpipe. For a strongly pulsating exhaust, the flow may shock at the pipe's open end at some point in a pulsating where the flow pressure exceeds its critical value. The method fails if one insists on setting the flow pressure equal to the atmospheric pressure as the pipe end boundary condition. To solve the problem, we set the Mach number equal to 1 as the boundary condition when the flow pressure exceeds its critical value. For a strongly pulsating flow, the fluctuations of flow variables may be much higher than their respective time averages. Therefore, the acoustic radiation method would fail in the computation of the noise radiation from the pipe's open end. We simulate the exhaust flow out of the open end as a simple sound source to compute the noise radiation, which has been successfully applied in reference [1]. The simple sound source strength is proportional to the volume acceleration of exhaust gas. Also computed is the noise radiation from the turbulence of the exhaust flow, as was done in reference [1]. Noise from a reciprocating valve simulator has been treated in detail. The radiation efficiency is very low for the pressure range considered and is about 10 -5. The radiation efficiency coefficient increases with the square of the frequency. Computation of the pipe length dependence of the noise radiation and mass flux allows us to design a suitable length for an aerodynamic noise generator or a reciprocating internal combustion engine. For the former, powerful noise radiation is preferable. For the latter, maximum mass flux is desired because a freer exhaust is preferable.

  6. Radiation exposure due to nuclear power

    This information brochure contains 12 earlier papers of leading experts on the radiation hazard the population incurs during normal operation of nuclear facilities and the radiation-biological fundamentals of the effects of ionizing radio humans. (HP) [de

  7. Electromagnetic radiation due to spacetime oscillations

    Chitre, D.M.; Price, R.H.; Sandberg, V.D.

    1975-01-01

    Wave equations are derived in the Newman-Penrose formalism for mixed electromagnetic and gravitational perturbations on both a flat spacetime background and a slightly charged (Q 2 very-much-less-than GM 2 ) Reissner-Nordstroem background. The physical meaning of these equations is discussed and analytical results are derived for nonrelativistic sources and for ultrarelativistic particle motions. The relationship between even-parity (TM) electromagnetic radiation multipoles in the long-wavelength approximation and static multipoles is shown to be the same as for classical radiation, suggesting a simple picture for electromagnetic radiation induced by gravitational perturbations

  8. Decoherence of coupled Josephson charge qubits due to partially correlated low-frequency noise

    Hu, Yong; Zhou, Zheng-Wei; Cai, Jian-Ming; Guo, Guang-Can

    2007-01-01

    Josephson charge qubits are promising candidates for scalable quantum computing. However, their performances are strongly degraded by decoherence due to low-frequency background noise, typically with a 1/f spectrum. In this paper, we investigate the decoherence process of two Cooper pair boxes (CPBs) coupled via a capacitor. Going beyond the common and uncorrelated noise models and the Bloch-Redfield formalism of previous works, we study the coupled system's quadratic dephasing under the condition of partially correlated noise sources. Based on reported experiments and generally accepted noise mechanisms, we introduce a reasonable assumption for the noise correlation, with which the calculation of multiqubit decoherence can be simplified to a problem on the single-qubit level. For the conventional Gaussian 1/f noise case, our results demonstrate that the quadratic dephasing rates are not very sensitive to the spatial correlation of the noises. Furthermore, we discuss the feasibility and efficiency of dynamical decoupling in the coupled CPBs

  9. An Experimental Study of the Noise Due to Traffic in a Congested Urban Area

    Sangeetha, M.; Sankar, P.

    2016-03-01

    Noise pollution in an urban environment is an issue of serious concern in the major cities of India. There are various factors that contribute to the increase of noise levels in urban areas. The intensity of traffic is one of the factors which contributes to a drastic increase in environmental noise. The management of noise pollution has to be considered in the decision making process. In this paper, an attempt is made to study the existing noise level due to the traffic in Velachery which is declared as a sensitive area by the Ministry of Environment and Forestry (MoEF). The noise level data is collected using the MS6710 digital sound meter. The Custic simulation software version 3.2 is used for finding the propagation of noise. The spatial patterns of measurement were also calculated, in the sub-urban area of Velachery, Chennai, Tamilnadu, India. A means of transmitting this data to vehicles moving in the area, through a wireless medium is simulated using NCTUns 6.0 (network simulator), to enable drivers to understand the environmental conditions. A hardware was also designed which can be used to transmit and receive the noise data using the Zigbee module. A noise transmitting station is placed at a junction, so that it can transmit this noise data to the receivers which are fitted inside the vehicles.

  10. Analytic approximate radiation effects due to Bremsstrahlung

    Ben-Zvi I.

    2012-02-01

    The purpose of this note is to provide analytic approximate expressions that can provide quick estimates of the various effects of the Bremsstrahlung radiation produced relatively low energy electrons, such as the dumping of the beam into the beam stop at the ERL or field emission in superconducting cavities. The purpose of this work is not to replace a dependable calculation or, better yet, a measurement under real conditions, but to provide a quick but approximate estimate for guidance purposes only. These effects include dose to personnel, ozone generation in the air volume exposed to the radiation, hydrogen generation in the beam dump water cooling system and radiation damage to near-by magnets. These expressions can be used for other purposes, but one should note that the electron beam energy range is limited. In these calculations the good range is from about 0.5 MeV to 10 MeV. To help in the application of this note, calculations are presented as a worked out example for the beam dump of the R&D Energy Recovery Linac.

  11. Radiation exposures due to fossil fuel combustion

    Beck, Harold L.

    The current consensus regarding the potential radiation exposures resulting from the combustion of fossil fuels is examined. Sources, releases and potential doses to humans are discussed, both for power plants and waste materials. It is concluded that the radiation exposure to most individuals from any pathway is probably insignificant, i.e. only a tiny fraction of the dose received from natural sources in soil and building materials. Any small dose that may result from power-plant emissions will most likely be from inhalation of the small insoluble ash particles from the more poorly controlled plants burning higher than average activity fuel, rather than from direct or indirect ingestion of food grown on contaminated soil. One potentially significant pathway for exposure to humans that requires further evaluation is the effect on indoor external γ-radiation levels resulting from the use of flyash in building materials. The combustion of natural gas in private dwellings is also discussed, and the radiological consequences are concluded to be generally insignificant, except under certain extraordinary circumstances.

  12. Analytic approximate radiation effects due to Bremsstrahlung

    Ben-Zvi, I.

    2012-01-01

    The purpose of this note is to provide analytic approximate expressions that can provide quick estimates of the various effects of the Bremsstrahlung radiation produced relatively low energy electrons, such as the dumping of the beam into the beam stop at the ERL or field emission in superconducting cavities. The purpose of this work is not to replace a dependable calculation or, better yet, a measurement under real conditions, but to provide a quick but approximate estimate for guidance purposes only. These effects include dose to personnel, ozone generation in the air volume exposed to the radiation, hydrogen generation in the beam dump water cooling system and radiation damage to near-by magnets. These expressions can be used for other purposes, but one should note that the electron beam energy range is limited. In these calculations the good range is from about 0.5 MeV to 10 MeV. To help in the application of this note, calculations are presented as a worked out example for the beam dump of the R and D Energy Recovery Linac.

  13. Flicker Noise in GNSS Station Position Time Series: How much is due to Crustal Loading Deformations?

    Rebischung, P.; Chanard, K.; Metivier, L.; Altamimi, Z.

    2017-12-01

    The presence of colored noise in GNSS station position time series was detected 20 years ago. It has been shown since then that the background spectrum of non-linear GNSS station position residuals closely follows a power-law process (known as flicker noise, 1/f noise or pink noise), with some white noise taking over at the highest frequencies. However, the origin of the flicker noise present in GNSS station position time series is still unclear. Flicker noise is often described as intrinsic to the GNSS system, i.e. due to errors in the GNSS observations or in their modeling, but no such error source has been identified so far that could explain the level of observed flicker noise, nor its spatial correlation.We investigate another possible contributor to the observed flicker noise, namely real crustal displacements driven by surface mass transports, i.e. non-tidal loading deformations. This study is motivated by the presence of power-law noise in the time series of low-degree (≤ 40) and low-order (≤ 12) Stokes coefficients observed by GRACE - power-law noise might also exist at higher degrees and orders, but obscured by GRACE observational noise. By comparing GNSS station position time series with loading deformation time series derived from GRACE gravity fields, both with their periodic components removed, we therefore assess whether GNSS and GRACE both plausibly observe the same flicker behavior of surface mass transports / loading deformations. Taking into account GRACE observability limitations, we also quantify the amount of flicker noise in GNSS station position time series that could be explained by such flicker loading deformations.

  14. Damping in accelerators due to classical radiation

    Mills, F.E.

    1962-01-01

    The rates of change of the magnitudes of the adiabatic invariants is calculated in the case of a Hamiltonian system subjected to generalized non conservative forces. These results are applied to the case of the classical radiation of electrons in an accelerator or storage ring. The resulting expressions for the damping rates of three independent oscillation modes suggest structures which are damping in all three modes, while at the same time allowing 'strong focussing' and the attendant strong momentum compaction. (author)

  15. Exterior Noise Due to Interaction of Tire-Thermoplastic Transverse Rumble Strips

    Haron Zaiton

    2017-01-01

    Full Text Available Transverse rumble strips (TRS are a common choice to reduce vehicle speed and increase driver alertness on roadways. However, there is a potential trade-off using them on rural roadway due to the noise problem created when vehicles go over the strips. The present study investigated the noise level, spectral analysis and the possible noise generation mechanism when the TRS hit by a vehicle. Ten-raised-rumbler (RR and three-layer-overlapped (TLO were selected in this study as they have received complaints from the public. Results showed that RR generated relatively higher noise and impulse at low speed, and increased sound level in each octave band. Based on these results, RR may irritate human ears even when the vehicle travels at low speed. It was found that RR increased all noise generation mechanism of tire-pavement interaction whilst for the TLO increased structural resonance, sidewall and surface texture vibration.

  16. Effects on Performance and Work Quality due to Low Frequency Ventilation Noise

    Persson Waye, K.; Rylander, R.; Benton, S.; Leventhall, H. G.

    1997-08-01

    A pilot study was carried out to assess method evaluating effects of low frequency noise on performance. Of special interest was to study objective and subjective effects over time. Two ventilation noises were used, one of a predominantly mid frequency character and the other of a predominantly low frequency character. Both had an NC value of 35. For the study, 50 students were recruited and 30 selected on the basis of subjective reports of pressure on the eardrum after exposure to a low frequency noise. Of these, 14 randomly selected subjects aged 21 and 34 took part. The subjects performed three computerized cognitive tests in the mid frequency or the low frequency noise condition alternatively. Tests I and II were performed together with a secondary task.Questionnaires were used to evaluate subjective symptoms, effects on mood and estimated interference with the test results due to temperature, light and noise. The results showed that the subjective estimations of noise interference with performance were higher for the low frequency noise (psocial orientation (pstudied. The results further indicate that the NC curves do not fully assess the negative effects of low frequency noise on work performance.

  17. The deterioration of signal to noise ratio due to baseline restoration

    Henein, K.L.

    1976-02-01

    The deterioration of signal to noise ratio due to baseline restoration is theoretically studied. This study brings to the conclusion that a restorer has negligible influence on the signal to noise ratio when its time constant is ten times greater than that of the main amplifier filter, and that the rapid restorers prevail over the slow ones when the time constant of the filter is increased by at least 50% of its optimal value [fr

  18. Annoyance due to noise and air pollution to the residents of heavily frequented streets

    Wanner, H. U.; Wehrli, B.; Nemecek, J.; Turrian, V.

    1980-01-01

    The residents of different streets with varying traffic density and building density were questioned about annoyance due to traffic noise and air pollution. Results show that annoyance felt is dependent not only on the measured noise levels and/or air pollution concentrations, but that there do exist interactions between the residential quarters and annoyance. These interactions should be considered when fixing the limits and standards.

  19. Partial and Total Annoyance Due to Road Traffic Noise Combined with Aircraft or Railway Noise: Structural Equation Analysis

    Gille, Laure-Anne; Marquis-Favre, Catherine; Lam, Kin-Che

    2017-01-01

    Structural equation modeling was used to analyze partial and total in situ annoyance in combined transportation noise situations. A psychophysical total annoyance model and a perceptual total annoyance model were proposed. Results show a high contribution of Noise exposure and Noise sensitivity to Noise annoyance, as well as a causal relationship between noise annoyance and lower Dwelling satisfaction. Moreover, the Visibility of noise source may increase noise annoyance, even when the visibl...

  20. Myocardial Infarction Risk Due to Aircraft, Road, and Rail Traffic Noise.

    Seidler, Andreas; Wagner, Mandy; Schubert, Melanie; Dröge, Patrik; Pons-Kühnemann, Jörn; Swart, Enno; Zeeb, Hajo; Hegewald, Janice

    2016-06-17

    Traffic noise can induce stress reactions that have effects on the cardiovascular system. The exposure-risk relationship between aircraft, road, and rail traffic noise and myocardial infarction is currently unknown. 19 632 patients from the Rhine-Main region of Germany who were diagnosed with myocardial infarction in the years 2006-2010 were compared with 834 734 control subjects. The assignment of persons to groups was performed on the basis of billing and prescription data from three statutory health insurance carriers. The exposure of all insurees to aircraft, road, and rail traffic noise in 2005 was determined from their residence addresses. As estimators of risk, odds ratios (OR) were calculated by logistic regression analysis, with adjustment for age, sex, regional social status variables, and individual social status (if available). The evaluation was performed on the basis of the continuous 24-hour noise level and the categorized noise level (in 5 decibel classes). The linear model revealed a statistically significant risk increase due to road noise (2.8% per 10 dB rise, 95% confidence interval [1.2; 4.5]) and railroad noise (2.3% per 10 dB rise [0.5; 4.2]), but not airplane noise. Airplane noise levels of 60 dB and above were associated with a higher risk of myocardial infarction (OR 1.42 [0.62; 3.25]). This higher risk is statistically significant if the analysis is restricted to patients who had died of myocardial infarction by 2014/2015 (OR 2.70 [1.08; 6.74]. In this subgroup, the risk estimators for all three types of traffic noise were of comparable magnitude (3.2% to 3.9% per 10 dB rise in noise level). In this study, a substantial proportion of the population was exposed to traffic noise levels that were associated with an albeit small increase in the risk of myocardial infarction. These findings underscore the importance of effective traffic noise prevention.

  1. Objective and subjective rating of tonal noise radiated from UK wind farms: Pt. 2

    1996-01-01

    This final report provides data on the assessment of tonal noise radiation from wind turbines in the United Kingdom. Both objective and subjective assessments of the noise pollution from various wind farms are incorporated in the study. Previous subjective tests are verified here using a larger subject and sample size compared to the initial study. The study also aims to produce an objective automatic tonal assessment procedure which identifies tones and broad band masking noise in wind farm radiated noise spectra. (UK)

  2. Emittance growth due to noise and its suppression with the Feedback system in large hadron colliders

    Lebedev, V.; Parkhomchuk, V.; Shiltsev, V.; Stupakov, G.

    1993-03-01

    The problem of emittance growth due to random fluctuation of the magnetic field in hadron colliders is considered. Based on a simple one-dimensional linear model, a formula for an emittance growth rate as a function of the noise spectrum is derived. Different sources of the noise are analyzed and their role is estimated for the Superconducting Super Collider (SSC). A theory of feedback suppression of the emittance growth is developed which predicts the residual growth of the emittance in the accelerator with a feedback system

  3. Radiation dose distributions due to sudden ejection of cobalt device.

    Abdelhady, Amr

    2016-09-01

    The evaluation of the radiation dose during accident in a nuclear reactor is of great concern from the viewpoint of safety. One of important accident must be analyzed and may be occurred in open pool type reactor is the rejection of cobalt device. The study is evaluating the dose rate levels resulting from upset withdrawal of co device especially the radiation dose received by the operator in the control room. Study of indirect radiation exposure to the environment due to skyshine effect is also taken into consideration in order to evaluate the radiation dose levels around the reactor during the ejection trip. Microshield, SHLDUTIL, and MCSky codes were used in this study to calculate the radiation dose profiles during cobalt device ejection trip inside and outside the reactor building. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Locating scatterers while drilling using seismic noise due to tunnel boring machine

    Harmankaya, U.; Kaslilar, A.; Wapenaar, K.; Draganov, D.

    2018-05-01

    Unexpected geological structures can cause safety and economic risks during underground excavation. Therefore, predicting possible geological threats while drilling a tunnel is important for operational safety and for preventing expensive standstills. Subsurface information for tunneling is provided by exploratory wells and by surface geological and geophysical investigations, which are limited by location and resolution, respectively. For detailed information about the structures ahead of the tunnel face, geophysical methods are applied during the tunnel-drilling activity. We present a method inspired by seismic interferometry and ambient-noise correlation that can be used for detecting scatterers, such as boulders and cavities, ahead of a tunnel while drilling. A similar method has been proposed for active-source seismic data and validated using laboratory and field data. Here, we propose to utilize the seismic noise generated by a Tunnel Boring Machine (TBM), and recorded at the surface. We explain our method at the hand of data from finite-difference modelling of noise-source wave propagation in a medium where scatterers are present. Using the modelled noise records, we apply cross-correlation to obtain correlation gathers. After isolating the scattered arrivals in these gathers, we cross-correlate again and invert for the correlated traveltime to locate scatterers. We show the potential of the method for locating the scatterers while drilling using noise records due to TBM.

  5. Plastic scintillation dosimetry for radiation therapy: minimizing capture of Cerenkov radiation noise

    Beddar, A Sam; Suchowerska, Natalka; Law, Susan H

    2004-01-01

    Over the last decade, there has been an increased interest in scintillation dosimetry using small water-equivalent plastic scintillators, because of their favourable characteristics when compared with other more commonly used detector systems. Although plastic scintillators have been shown to have many desirable dosimetric properties, as yet there is no successful commercial detector system of this type available for routine clinical use in radiation oncology. The main factor preventing this new technology from realizing its full potential in commercial applications is the maximization of signal coupling efficiency and the minimization of noise capture. A principal constituent of noise is Cerenkov radiation. This study reports the calculated capture of Cerenkov radiation by an optical fibre in the special case where the radiation is generated by a relativistic particle on the fibre axis and the fibre axis is parallel to the Cerenkov cone. The fraction of radiation captured is calculated as a function of the fibre core refractive index and the refractive index difference between the core and the cladding of the fibre for relativistic particles. This is then used to deduce the relative intensity captured for a range of fibre core refractive indices and fibre core-cladding refractive index differences. It is shown that the core refractive index has little effect on the amount of radiation captured compared to the refractive index difference. The implications of this result for the design of radiation therapy plastic scintillation dosimeters are considered

  6. Large Civil Tiltrotor (LCTR2) Interior Noise Predictions due to Turbulent Boundary Layer Excitation

    Grosveld, Ferdinand W.

    2013-01-01

    The Large Civil Tiltrotor (LCTR2) is a conceptual vehicle that has a design goal to transport 90 passengers over a distance of 1800 km at a speed of 556 km/hr. In this study noise predictions were made in the notional LCTR2 cabin due to Cockburn/Robertson and Efimtsov turbulent boundary layer (TBL) excitation models. A narrowband hybrid Finite Element (FE) analysis was performed for the low frequencies (6-141 Hz) and a Statistical Energy Analysis (SEA) was conducted for the high frequency one-third octave bands (125- 8000 Hz). It is shown that the interior sound pressure level distribution in the low frequencies is governed by interactions between individual structural and acoustic modes. The spatially averaged predicted interior sound pressure levels for the low frequency hybrid FE and the high frequency SEA analyses, due to the Efimtsov turbulent boundary layer excitation, were within 1 dB in the common 125 Hz one-third octave band. The averaged interior noise levels for the LCTR2 cabin were predicted lower than the levels in a comparable Bombardier Q400 aircraft cabin during cruise flight due to the higher cruise altitude and lower Mach number of the LCTR2. LCTR2 cabin noise due to TBL excitation during cruise flight was found not unacceptable for crew or passengers when predictions were compared to an acoustic survey on a Q400 aircraft.

  7. Noise characteristics of U. S. synchrotron radiation sources

    Powers, L.

    1986-01-01

    Noise characteristics of the U. S. x-ray synchrotron sources are compared in the 0--2.5-kHz region. In general, little difference is found in the characteristic frequencies of the noise on focused and unfocused beamlines of a particular source, but the magnitude and white-noise levels differ. The National Synchrotron Light Source shows the least characteristic noise and the noise that is observed is small in magnitude (2--3 times the white-noise level)

  8. Noise Attenuation Loss Due to Wearing APEL Eye Protection with Ear-Muff Style Headset Systems

    2012-02-14

    USAARL Report No. 2012-09 Noise Attenuation Loss Due to Wearing APEL Eye Protection with Ear-Muff Style Headset Systems By Efrem Reeves Elmaree...Cameron Station, Alexandria, Virginia 22314. Orders will be expedited if placed through the librarian or other person designated to request...not be construed as an official Department of the Army position, policy, or decision, unless so designated by other official documentation. Citation

  9. Reduction in thermal conductivity of ceramics due to radiation damage

    Klemens, P.G.; Hurley, G.F.; Clinard, F.W. Jr.

    1976-01-01

    Ceramics are required for a number of applications in fusion reactors. In several of these applications, the thermal conductivity is an important design parameter as it affects the level of temperature and thermal stress in service. Ceramic insulators are known to suffer substantial reduction in thermal conductivity due to neutron irradiation damage. The present study estimates the reduction in thermal conductivity at high temperature due to radiation induced defects. Point, extended, and extended partly transparent defects are considered

  10. RAMs: the problem of transient errors due to alpha radiation

    Goujon, Pierre.

    1980-01-01

    Errors that remained unexplained for a long time have occurred with dynamic random access memories. It has been known since 1978 that they are due to stray alpha radiation. A good understanding of this phenomenon enables its effects to be neutralized and the reliability of the products to be guarantied [fr

  11. Radiation from nitrogen molecule due to electron impact

    Khare, S P; Kumar, A

    1977-01-01

    A review is presented of the experimental results of the collisional cross sections of the nitrogen molecules due to electron impact which give rise to radiations in the 3,000 Angstrom to 10,500 Angstron wavelength region. Calculations of the fluorescence efficiencies are described and are compared with experimental data. (GHT)

  12. Radiation and noise exposures elicit biological and behavioural effects in the rat

    Trivedi, A.; Michaud, D.S.; Ferrarotto, C.; Keith, S.E.; Miller, S.M.; Bowers, W.J.; Kumarathsan, P.

    2003-01-01

    The presence of radiation and noise is ubiquitous in a living environment. Therefore, the effect of these sources alone and together on the body has the potential for public health consequences. We have examined the physiological and behavioural effects of separate and combined exposures to radiation and noise in adult male Sprague-Dawley rats. For three weeks animals were exposed to the following conditions: 1) daily exposure to x-rays (cumulative whole body dose = 5Gy); 2) random intermittent noise band-limited between 400Hz-20 kHz; 2 h/day 90 dB lin and 3) combined exposures. Control animals were housed under ambient noise conditions (∼ 55-60 dBA) and sham-exposed to x-rays. The mean body weight gain (initial avg. ∼ 250g) appeared to be affected by the treatments; control (88g); noise (76g); radiation (60g) and noise/radiation (43g). Compared to control and noise only animals, plasma levels of 8-hydroxy-2'-deoxyguanosine increased significantly in animals exposed to both radiation alone and radiation with noise, while big-endothelin-1 was significantly reduced in both groups exposed to radiation. There were no noticeable changes in the levels of adrenocorticotrophic hormone and the variability in plasma norepinephrine and epinephrine precluded conclusions with respect to changes in sympathetic activity. No groups showed any consistent changes in plasma levels of interleukin-1, corticotrophin releasing hormone or urocortin. Plasma corticosterone increased in animals exposed to only noise, but this hormone was significantly reduced in animals exposed to only radiation. Behavioural endpoints revealed that startle amplitude (105dB) was highest in animals exposed to only noise and lowest in animals exposed to both noise and radiation, compared to the control animals. These results suggest that radiation exposure might alter systems activated by stressor exposure and/or act independently to influence health outcomes

  13. Nonlinear radiation of waves at combination frequencies due to radiation-surface wave interaction in plasmas

    El Naggar, I.A.; Hussein, A.M.; Khalil, Sh.M.

    1992-09-01

    Electromagnetic waves radiated with combination frequencies from a semi-bounded plasma due to nonlinear interaction of radiation with surface wave (both of P-polarization) has been investigated. Waves are radiated both into vacuum and plasma are found to be P-polarized. We take into consideration the continuity at the plasma boundary of the tangential components of the electric field of the waves. The case of normal incidence of radiation and rarefield plasma layer is also studied. (author). 7 refs

  14. Nutritional and metabolic changes due the abdominal radiation: experimental study

    Mucerino, Donato R.; Waitzberg, Dan L.; Campos, Fabio G. de; Melo Auricchio, Maria T. de; Gama-Rodrigues, Joaquim J.; Lima-Goncalves, Ernesto L.

    1995-01-01

    In this study the effects on nutritional status and energetic metabolism due the abdominal irradiation were analysed. Adult male wistar rats (48), were divided in two groups Control (C) and radiated (R). The rats were maintained all time in metabolic cages. the study was done in two periods: period 1 begun at 0 day, were rats adapted to cages and oral diet, had food and water ad libitum. At the day four indirect calorimetric measurements were performed (calorimetry 1). At period 2, group R rats abdominal radiation at a 300 c Gy/day rate, for 5 consecutive days, and group C started a pair-feeding process linked individually to R rats and suffered application to simulated-irradiation. Two other calorimetric measurements (II,III) were performing during period 2. After radiation the last calorimetry was performed (IV). At sacrifice (day 14) blood was collected for determination of hemoglobin, hematocrit, albumin and transferrin. There were no statistical differences among groups C and R during period 1 (p < 0.05). Great reduction in food intake and weight variation were found in period 2, but weight loss was significantly higher in R rats. Nitrogen balance decrease in period 2, but without difference among the groups (p < 0.05). Serum albumin was significantly lower in R rats. Respiratory quotient decreased in both groups during period 2, but rats kept it lower (p < 0.05). The energy expenditure level decreased after radiation in group R. During period 2 total substrate oxidation decreased in R rats. Radiation decrease glucose and protein oxidation. In conclusion, in this study's conditions, radiation produced malnutrition by reducing food intake by bringing weight loss, hypoalbuminemia and decrease nitrogen balance. Radiation was also responsible for a reduction of metabolism, by promoting the fall of energy expenditure. These changes are not only due the anorexia, undoubtful a main factor. (author)

  15. Dynamic analysis of the Nova Target Chamber to assess alignment errors due to ambient noise

    McCallen, D.B.; Murray, R.C.

    1984-01-01

    We performed a study to determine the dynamic behavior of the Nova Target Chamber. We conducted a free vibration analysis to determine the natural frequencies of vibration and the corresponding modeshapes of the target chamber. Utilizing the free vibration results, we performed forced vibration analysis to predict the displacements of the chamber due to ambient vibration. The input support motion for the forced vibration analysis was defined by a white noise acceleration spectrum which was based on previous measurements of ground noise near the Nova site. A special purpose computer program was prepared to process the results of the forced vibration analysis. The program yields distances by which the lines of sight of the various laser beams miss the target as a result of ambient vibrations. We also performed additional estimates of miss distance to provide bounds on the results. A description of the finite element model of the chamber, the input spectrum, and the results of the analyses are included

  16. Radiation dose distributions due to sudden ejection of cobalt device

    Abdelhady, Amr

    2016-01-01

    The evaluation of the radiation dose during accident in a nuclear reactor is of great concern from the viewpoint of safety. One of important accident must be analyzed and may be occurred in open pool type reactor is the rejection of cobalt device. The study is evaluating the dose rate levels resulting from upset withdrawal of co device especially the radiation dose received by the operator in the control room. Study of indirect radiation exposure to the environment due to skyshine effect is also taken into consideration in order to evaluate the radiation dose levels around the reactor during the ejection trip. Microshield, SHLDUTIL, and MCSky codes were used in this study to calculate the radiation dose profiles during cobalt device ejection trip inside and outside the reactor building. - Highlights: • This study aims to calculate the dose rate profiles after cobalt device ejection from open-pool-type reactor core. • MicroShield code was used to evaluate the dose rates inside the reactor control room. • McSKY code was used to evaluate the dose rates outside the reactor building. • The calculated dose rates for workers are higher than the permissible limits after 18 s from device ejection.

  17. Active noise canceling system for mechanically cooled germanium radiation detectors

    Nelson, Karl Einar; Burks, Morgan T

    2014-04-22

    A microphonics noise cancellation system and method for improving the energy resolution for mechanically cooled high-purity Germanium (HPGe) detector systems. A classical adaptive noise canceling digital processing system using an adaptive predictor is used in an MCA to attenuate the microphonics noise source making the system more deployable.

  18. Computer simulation of the emittance growth due to noise in large hadron colliders

    Lebedev, V.

    1993-03-01

    The problem of emittance growth due to random fluctuations of the magnetic field in a hadron collider is considered. The results of computer simulations are compared with the analytical theory developed earlier. A good agreement was found between the analytical theory predictions and the computer simulations for the collider tunes located far enough from high order betatron resonances. The dependencies of the emittance growth rate on noise spectral density, beam separation at the Interaction Point (IP) and value of beam separation at long range collisions are studied. The results are applicable to the Superconducting Super Collider (SSC)

  19. Development of a noise filter for radiation thickness gagemeter

    Jee, C. W.; Kim, Y. T.; Lee, H. H.

    1995-01-01

    The objective of this study is to develop a filter which attenuates sensor noises of radiation thickness gagemeters of the fifth stand of TCM No. 1 in Pohang steel works. The thickness control loop for the fifth stand is modelled as a system for filter design, where the system input is the speed control input and the system output is the gagemeter output. In the design of a filter, the system is described by an ARMAX(AutoRegressive Moving-Average with auXiliary input) model. The parameters of this model are then estimated by using a recursive least square method. Secondly, the ARMAX model, the estimated system, is transformed into an observer canonical state space form. Thirdly, Kalman filtering is applied to obtain optimal estimates of the state and hence those of thickness measurements of steel strips. In addition, a separate low pass filter is designed, which is directly applicable to the gagemeter outputs. Finally, the designed filter algorithms are implemented and tested on a VMEbus board computer under VxWorks real-time operating system. (author)

  20. Noise Radiation From a Leading-Edge Slat

    Lockard, David P.; Choudhari, Meelan M.

    2009-01-01

    This paper extends our previous computations of unsteady flow within the slat cove region of a multi-element high-lift airfoil configuration, which showed that both statistical and structural aspects of the experimentally observed unsteady flow behavior can be captured via 3D simulations over a computational domain of narrow spanwise extent. Although such narrow domain simulation can account for the spanwise decorrelation of the slat cove fluctuations, the resulting database cannot be applied towards acoustic predictions of the slat without invoking additional approximations to synthesize the fluctuation field over the rest of the span. This deficiency is partially alleviated in the present work by increasing the spanwise extent of the computational domain from 37.3% of the slat chord to nearly 226% (i.e., 15% of the model span). The simulation database is used to verify consistency with previous computational results and, then, to develop predictions of the far-field noise radiation in conjunction with a frequency-domain Ffowcs-Williams Hawkings solver.

  1. Radiation exposure due to agricultural uses of phosphate fertilizers

    Khater, Ashraf E.M.; AL-Sewaidan, H.A.

    2008-01-01

    Radiological impacts of phosphate rocks mining and manufacture could be significant due to the elevated radioactivity contents of the naturally occurring radioactive materials (NORM), such as 238 U series, 232 Th series and 40 K, in some phosphate deposits. Over the last decades, the land reclamation and agriculture activities in Saudi Arabia and other countries have been widely expanded. Therefore, the usage of chemical fertilizers is increased. Selected phosphate fertilizers samples were collected and the specific activities of NORM were measured using a gamma ray spectrometer based on a hyper pure germanium detector and alpha spectrometer based on surface barrier detector. The obtained results show remarkable wide variations in the radioactivity contents of the different phosphate fertilizer samples. The mean (ranges) of specific activities for 226 Ra, 210 Po, 232 Th and 40 K, and radium equivalent activity are 75 (3-283), 25 (0.5-110), 23 (2-74), 2818 (9-6501) Bq/kg and 283 (7-589) Bq/kg, respectively. Based on dose calculations, the increment of the public radiation exposure due to the regular agricultural usage of phosphate fertilizers is negligible. Its average value 1 m above the ground is about 0.12 nGy/h where the world average value due to the NORM in soil is 51 nGy/h. Direct radiation exposures of the farmers due to phosphate fertilizers application was not considered in our study

  2. Experimental Characterization of Radiation Forcing due to Atmospheric Aerosols

    Sreenivas, K. R.; Singh, D. K.; Ponnulakshmi, V. K.; Subramanian, G.

    2011-11-01

    Micro-meteorological processes in the nocturnal atmospheric boundary layer (NBL) including the formation of radiation-fog and the development of inversion layers are controlled by heat transfer and the vertical temperature distribution close to the ground. In a recent study, it has been shown that the temperature profile close to the ground in stably-stratified, NBL is controlled by the radiative forcing due to suspended aerosols. Estimating aerosol forcing is also important in geo-engineering applications to evaluate the use of aerosols to mitigate greenhouse effects. Modeling capability in the above scenarios is limited by our knowledge of this forcing. Here, the design of an experimental setup is presented which can be used for evaluating the IR-radiation forcing on aerosols under either Rayleigh-Benard condition or under conditions corresponding to the NBL. We present results indicating the effect of surface emissivities of the top and bottom boundaries and the aerosol concentration on the temperature profiles. In order to understand the observed enhancement of the convection-threshold, we have determined the conduction-radiation time constant of an aerosol laden air layer. Our results help to explain observed temperature profiles in the NBL, the apparent stability of such profiles and indicate the need to account for the effect of aerosols in climatic/weather models.

  3. Intrinsic speckle noise in in-line particle holography due to polydisperse and continuous particle sizes

    Edwards, Philip J.; Hobson, Peter R.; Rodgers, G. J.

    2000-08-01

    In-line particle holography is subject to image deterioration due to intrinsic speckle noise. The resulting reduction in the signal to noise ratio (SNR) of the replayed image can become critical for applications such as holographic particle velocimetry (HPV) and 3D visualisation of marine plankton. Work has been done to extend the mono-disperse model relevant to HPV to include poly-disperse particle fields appropriate for the visualisation of marine plankton. Continuous and discrete particle fields are both considered. It is found that random walk statistics still apply for the poly-disperse case. The speckle field is simply the summation of the individual speckle patters due to each scatter size. Therefor the characteristic speckle parameter (which encompasses particle diameter, concentration and sample depth) is alos just the summation of the individual speckle parameters. This reduces the SNR calculation to the same form as for the mono-disperse case. For the continuous situation three distributions, power, exponential and Gaussian are discussed with the resulting SNR calcuated. The work presented here was performed as part of the Holomar project to produce a working underwater holographic camera for recording plankton.

  4. Resistance to antitumor chemotherapy due to bounded-noise-induced transitions

    D'Onofrio, Alberto; Gandolfi, Alberto

    2010-12-01

    Tumor angiogenesis is a landmark of solid tumor development, but it is also directly relevant to chemotherapy. Indeed, the density and quality of neovessels may influence the effectiveness of therapies based on blood-born agents. In this paper, first we define a deterministic model of antiproliferative chemotherapy in which the drug efficacy is a unimodal function of vessel density, and then we show that under constant continuous infusion therapy the tumor-vessel system may be multistable. However, the actual drug concentration profiles are affected by bounded even if possibly large fluctuations. Through numerical simulations, we show that the tumor volume may undergo transitions to the higher equilibrium value induced by the bounded noise. In case of periodically delivered boli-based chemotherapy, we model the fluctuations due to time variability of both the drug clearance rate and the distribution volume, as well as those due to irregularities in drug delivery. We observed noise-induced transitions also in case of periodic delivering. By applying a time dense scheduling with constant average delivered drug (metronomic scheduling), we observed an easier suppression of the transitions. Finally, we propose to interpret the above phenomena as an unexpected non-genetic kind of resistance to chemotherapy.

  5. The Effects of Ambient Conditions on Helicopter Harmonic Noise Radiation: Theory and Experiment

    Greenwood, Eric; Sim, Ben W.; Boyd, D. Douglas, Jr.

    2016-01-01

    The effects of ambient atmospheric conditions, air temperature and density, on rotor harmonic noise radiation are characterized using theoretical models and experimental measurements of helicopter noise collected at three different test sites at elevations ranging from sea level to 7000 ft above sea level. Significant changes in the thickness, loading, and blade-vortex interaction noise levels and radiation directions are observed across the different test sites for an AS350 helicopter flying at the same indicated airspeed and gross weight. However, the radiated noise is shown to scale with ambient pressure when the flight condition of the helicopter is defined in nondimensional terms. Although the effective tip Mach number is identified as the primary governing parameter for thickness noise, the nondimensional weight coefficient also impacts lower harmonic loading noise levels, which contribute strongly to low frequency harmonic noise radiation both in and out of the plane of the horizon. Strategies for maintaining the same nondimensional rotor operating condition under different ambient conditions are developed using an analytical model of single main rotor helicopter trim and confirmed using a CAMRAD II model of the AS350 helicopter. The ability of the Fundamental Rotorcraft Acoustics Modeling from Experiments (FRAME) technique to generalize noise measurements made under one set of ambient conditions to make accurate noise predictions under other ambient conditions is also validated.

  6. Lageos orbit decay due to infrared radiation from earth

    Rubincam, David Parry

    1987-01-01

    Infrared radiation from the earth may be the principal reason for the decay of Lageos' orbit. The radiation heats up the laser retroreflectors embedded in Lageos' aluminum surface. This creates a north-south temperature gradient on the satellite. The gradient in turn causes a force to be exerted on Lageos because of recoil from photons leaving its surface. The delayed heating of the retroreflectors due to their thermal inertia gives the force a net along-track component which always acts like drag. A simple thermal model for the retroreflectors indicates that this thermal drag accounts for about half the observed average along-track acceleration of -3.3 x 10 to the -10th power m/sec squared. The contribution from the aluminum surface to this effect is negligible. The infrared effect cannot explain the large observed fluctuations in drag which occur mainly when the orbit intersects the earth's shadow.

  7. Radiation sensitivity of noise in monolithic JFET circuits exposed to 60Co γ - rays

    Cesura, G.; Re, V.; Tomasini, A.

    1993-01-01

    The spectral density of channel current noise in JFET's is governed in the low-frequency region by Lorentzian terms. Ordinarily, their influence on the equivalent noise charge of preamplifiers for radiation detectors is negligible, as these terms vanish as soon as the frequency exceeds a few Hz. Exposure of JFET's to γ - rays has proved, however, that these noise contributions are enhanced by the absorbed radiation and may invade a much broader frequency range, thereby degrading the equivalent noise charge even at comparatively short processing times. The extent to which the noise behaviour of JFET's is affected by radiation-enhanced Lorentzian terms is analysed in this paper. Results of measurements, carried out after exposure to 60 Co γ - rays of JFET parts and monolithic circuits realised in two different technologies, are discussed and compared with the theoretical predictions. (orig.)

  8. The assessment of personal dose due to external radiation

    Boas, J.F.; Young, J.G.

    1990-01-01

    The fundamental basis of thermoluminescent dosimetry (TLD) is discussed and a number of considerations in the measurement of thermoluminescence described, with particular reference to CaSO 4 :Dy. The steps taken to convert a thermoluminescence measurement to an exposure and then an absorbed dose are outlined. The calculation of effective dose equivalents due to external exposure to γ-radiation in a number of situations commonly encountered in a uranium mine is discussed. Factors which may affect the accuracy of external dose assessments are described

  9. Diurnally varying annoyance due to railway and road traffic noise; Laermbelaestigung durch Strassen- und Schienenverkehr zu unterschiedlichen Tageszeiten

    Schreckenberg, D. [Zentrum fuer Angewandte Psychologie, Umwelt- und Sozialforschung (ZEUS GmbH), Bochum (Germany); Guski, R. [Ruhr-Univ. Bochum, Fakultaet fuer Psychologie, Bochum (Germany)

    2005-07-01

    One of the most prominent non-auditory effects of noise influencing the life quality of human beings is the disturbance of activities (i.e. communicating, relaxing, working, sleeping). The disturbance of activities results in noise annoyance, and in the long run may lead to further health effects. Due to the fact that activities vary diurnally it is plausible to assume that peoples'' responses to noise differ depending on the times of day. The aim of the study, which is part of the German research network ''Quiet Traffic'' is to provide empirical data of dose-response relationships for different times of day (excluding the night). 1110 residents from four areas with dominant road traffic noise (683 subjects) and from two areas with dominant railway noise (427 subjects) have been asked in a face-to-face interview for contentment with house and living environment and noise reactions. 131 persons of the total sample took part in an additional study (experience-sampling study) in which the hourly noise annoyance was measured for three consecutive days using a handheld computer. For each subject individual source-specific immission noise level for each hour of the day has been calculated. There is higher annoyance due to road traffic noise in the late afternoon/evening from 4 pm to 7 pm. For railway noise higher annoyance is reported in the evening from 6 pm to 10 am. The reported differences in noise annoyance depending on the times of day are higher with increasing noise level. (orig.)

  10. Noise

    Noise is all around you, from televisions and radios to lawn mowers and washing machines. Normally, you ... sensitive structures of the inner ear and cause noise-induced hearing loss. More than 30 million Americans ...

  11. Collective studies on carcinogenesis due to exposure to radiation

    Yamashita, Hisao

    1980-01-01

    Carcinogenesis was found in 150 of 25,692 patients who had received radiotherapy for benign diseases. Of primary diseases subjected to radiotherapy, skin diseases were the most. Carcinogenesis was found in 26 of 7,230 patients with skin diseases (0.36%) and 18 in 2286 patients with tuberculous cervical lymphadenitis (0.79%). The sites of carcinogenesis was the skin in 51 patients, the hypopharynx in 43, and the larynx in 18. Carcinogenesis was also found in 140 of 220,361 patients who had received radiotherapy for malignant tumors. As primary cancer, cancer of the cervix uteri was found in 59 of 48,662 patients, and breast cancer was found in 20 of 27,967 patients. As radiation-induced cancer, leukemia was found in 18 patients, soft tissue sarcoma in 18, skin cancer in 10, osteosarcoma in 6, cancer of the hypopharynx in 6, and cancer of the cervical esophagus in 6. It is necessary to differentiate cancer due to exposure to radiation from delayed recurrent cancer and double cancer. Irradiation fields should be restricted as small as possible in order to reduce carcinogenesis. As leukemia and carcinoma were found in a-bomb survivors exposed to very small dose of a-bomb radiation, carcinogenic mechanisms by chromosome aberrations, carcinogenic rates from a viewpoint of epidemiology, and other factors which influenced carcinogenesis are being investigated. (Tsunoda, M.)

  12. A study for reduction of radiation pressure noise in gravitational wave detectors

    Sakata, S; Sugamoto, A [Graduate School of Humanities and Sciences, Ochanomizu University, 2-1-1 Otsuka, Bunkyo-ku, Tokyo, 112-8610 (Japan); Leonhardt, V; Kawamura, S; Sato, S; Yamazaki, T; Fukushima, M [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Numata, K [NASA Goddard Space Flight Center, CRESST, Code 663, Greenbelt, MD 20771 (United States); Miyakawa, O [LIGO Laboratory 18-34, California Institute of Technology, Pasadena, CA 91125 (United States); Nishizawa, A [Graduate School of Human and Environmental Studies, Kyoto University, Kyoto 606-8501 (Japan); Furusawa, A [Department of Applied Physics, School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)], E-mail: shihori.sakata@nao.ac.jp

    2008-07-15

    We describe an experimental conceptual design for observation and reduction of radiation pressure noise. The radiation pressure noise is increased in a high finesse cavity with a small mass mirror. In our experiment a Fabry-Perot Michelson interferometer with a homodyne detection scheme will be built with Fabry-Perot cavities of finesse of 10000 containing suspended mirrors of 23 mg. To observe the radiation pressure noise, the goal sensitivity is set to 1x10{sup -17} [m/ {radical}Hz] at 1 kHz. Then the radiation pressure noise is reduced by adjusting the homodyne phase. To achieve the sensitivity, the other noise sources such as thermal noises, seismic noise and laser frequency noise should be suppressed below 1x10{sup -18} [m/{radical} Hz] at 1kHz. The whole interferometer is suspended as a double pendulum on double-layer stacks. As a preliminary setup, a Fabry-Perot cavity of finesse of 800 with a suspended mirror of 100 mg was locked. The current best sensitivity is 1x10{sup -15} [m/ {radical}Hz] at 1 kHz.

  13. Lévy noise improves the electrical activity in a neuron under electromagnetic radiation.

    Wu, Juan; Xu, Yong; Ma, Jun

    2017-01-01

    As the fluctuations of the internal bioelectricity of nervous system is various and complex, the external electromagnetic radiation induced by magnet flux on membrane can be described by the non-Gaussian type distribution of Lévy noise. Thus, the electrical activities in an improved Hindmarsh-Rose model excited by the external electromagnetic radiation of Lévy noise are investigated and some interesting modes of the electrical activities are exhibited. The external electromagnetic radiation of Lévy noise leads to the mode transition of the electrical activities and spatial phase, such as from the rest state to the firing state, from the spiking state to the spiking state with more spikes, and from the spiking state to the bursting state. Then the time points of the firing state versus Lévy noise intensity are depicted. The increasing of Lévy noise intensity heightens the neuron firing. Also the stationary probability distribution functions of the membrane potential of the neuron induced by the external electromagnetic radiation of Lévy noise with different intensity, stability index and skewness papremeters are analyzed. Moreover, through the positive largest Lyapunov exponent, the parameter regions of chaotic electrical mode of the neuron induced by the external electromagnetic radiation of Lévy noise distribution are detected.

  14. Lévy noise improves the electrical activity in a neuron under electromagnetic radiation.

    Juan Wu

    Full Text Available As the fluctuations of the internal bioelectricity of nervous system is various and complex, the external electromagnetic radiation induced by magnet flux on membrane can be described by the non-Gaussian type distribution of Lévy noise. Thus, the electrical activities in an improved Hindmarsh-Rose model excited by the external electromagnetic radiation of Lévy noise are investigated and some interesting modes of the electrical activities are exhibited. The external electromagnetic radiation of Lévy noise leads to the mode transition of the electrical activities and spatial phase, such as from the rest state to the firing state, from the spiking state to the spiking state with more spikes, and from the spiking state to the bursting state. Then the time points of the firing state versus Lévy noise intensity are depicted. The increasing of Lévy noise intensity heightens the neuron firing. Also the stationary probability distribution functions of the membrane potential of the neuron induced by the external electromagnetic radiation of Lévy noise with different intensity, stability index and skewness papremeters are analyzed. Moreover, through the positive largest Lyapunov exponent, the parameter regions of chaotic electrical mode of the neuron induced by the external electromagnetic radiation of Lévy noise distribution are detected.

  15. Investigation of reactivity change and neutron noise due to random absorber vibrations. 2

    Barthel, R.

    1984-01-01

    Perturbations of the neutron flux due to stochastically excited vibrations of absorbers have been investigated using a one-dimensional core model with N pointlike absorbers. Taking into account the flux depressions near the absorbers, pronounced peaks in the spectral power densities of the flux fluctuations have been found at multiples of the resonance frequencies in addition to the direct imaging of the resonances of absorber vibrations. Investigation of the space dependence of the corresponding transfer functions has shown that a localization is possible by means of the double frequency effect and that the dispersion of absorber vibrations can be determined by using the triple frequency effect. The conclusions of the paper are qualitatively compared with results of noise measurements at a pressurized water reactor. (author)

  16. Experimental study of combustion noise radiation during transient turbocharged diesel engine operation

    Giakoumis, Evangelos G.; Dimaratos, Athanasios M.; Rakopoulos, Constantine D.

    2011-01-01

    Diesel engine noise radiation has drawn increased attention in recent years since it is associated with the passengers' and pedestrians' discomfort, a fact that has been acknowledged by the manufacturers and the legislation in many countries. In the current study, experimental tests were conducted on a truck, turbocharged diesel engine in order to investigate the mechanism of combustion noise emission under various transient schedules experienced during daily driving conditions, namely acceleration and load increase. To this aim, a fully instrumented test bed was set up in order to capture the development of key engine and turbocharger variables during the transient events. Analytical diagrams are provided to explain the behavior of combustion noise radiation in conjunction with cylinder pressure (spectrum), turbocharger and governor/fuel pump response. Turbocharger lag was found to be the main cause for the noise spikes during all test cases examined, with the engine injection timing calibration and the slow adjustment of cylinder wall temperature to the new fueling conditions playing a vital role. The analysis was extended with a quasi-steady approximation of transient combustion noise using steady-state maps, in order to better highlight the effect of dynamic engine operation on combustion noise emissions. -- Highlights: → Studying the effects of acceleration and load increase on the combustion noise radiation from a turbocharged diesel engine. → Turbocharger lag was the most notable contributor for the behavior of combustion noise radiation. → Turbocharged diesel engine behaves noisier at acceleration compared with the steady-state operation. → Fuel limiter, governing and engine injection timing calibration play a decisive role on the emission of combustion noise. → Transient noise radiation was smoothed the slower the acceleration and the smaller the demanded speed increase.

  17. Ionizing radiation dose due to the use of agricultural fertilizers

    Umisedo, Nancy Kuniko

    2007-01-01

    Among several agents that exist in the environment which can expose to different risks and effects, there is the ionizing radiation whose knowledge of dose is of importance to the effective control and prevention of possible damages to human beings and to the environment. The transfer of radionuclides from fertilizers to/and soils to the foodstuffs can result as an increment in the internal dose when they are consumed by the human beings. This work evaluates the contribution of fertilizers to the ionizing radiation dose in the environment and in the human being. Samples of fertilizers, soils and vegetables produced in fertilized soils were analysed through gamma spectrometry with the use of a hyper pure germanium detector. Measurements of ambient dose with thermoluminescent dosimeters were also performed. In the fertilized soil samples values of specific activities from 36 to 342 Bq/kg for K-40, from 42 to 142 Bq/kg for U-238 and from 36 to 107 Bq/kg for Th-232 were obtained. In the vegetables the values varied from 21 to 118 Bq/kg for K-40 and for the elements of uranium and thorium series the values were less than 2 Bq/kg. In fertilizers the maximum value of 5800 Bq/kg was obtained for K-40, 430 Bq/kg for U-238 and 230 Bq/kg for Th-232. The average values of soil to plant transfer factor were not significantly different among the types of vegetables. The annual committed effective dose of 0.882 μSv due to the ingestion of K-40 from the analysed vegetables is very small if compared to the reference value of 170 μv given by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR, 2000). The thermoluminescent dosimetry provided the annual ambient dose equivalent from 1.5 to 1.8 mSv without differences between cultivated and non cultivated fields. Through the results obtained, it was not observed a significant transfer of radionuclides from fertilizers to soils and to foodstuffs in the conditions adopted in this work and consequently there

  18. Effects on vegetable seeds due to non ionizing radiation

    Acri, G.; Oliva, A.; Falcone, G. [Universita della Calabria, Dipt. di Fisica, Cosenza (Italy); Acri, G.; Testagrossa, B.; Vermiglio, G.; Tripepi, M.G. [Universita della Calabria, Dipt. di Ecologia, Cosenza (Italy); Bitonti, M.B.; Chiappetta, A. [Universita di Messina, Dipt. di Protezionistica Ambientale, Sanitaria, Sociale ed Industriale, Messina (Italy)

    2006-07-01

    Based on the tightly relationship between light and plants growth and development, the present work aims to obtain some further insight into the effects of non ionizing radiation the photo-autotrophic organisms, due to the relevant implications for both scientific knowledge and economical and social effects. In this context, a set of experiments was conducted to investigate the influence of a long-lasting exposition to both RF at 1850 MHz and polarized light source on roots elongation of corn kernels. The radical apparatus was chosen as a sensible parameter and the elongation of the roots was monitored as a function of time. Mitotic index and length of meta-xylem cells were estimated in root apex as an index of cell proliferation and cell expansion activity, respectively. (N.C.)

  19. Effects on vegetable seeds due to non ionizing radiation

    Acri, G.; Oliva, A.; Falcone, G.; Acri, G.; Testagrossa, B.; Vermiglio, G.; Tripepi, M.G.; Bitonti, M.B.; Chiappetta, A.

    2006-01-01

    Based on the tightly relationship between light and plants growth and development, the present work aims to obtain some further insight into the effects of non ionizing radiation the photo-autotrophic organisms, due to the relevant implications for both scientific knowledge and economical and social effects. In this context, a set of experiments was conducted to investigate the influence of a long-lasting exposition to both RF at 1850 MHz and polarized light source on roots elongation of corn kernels. The radical apparatus was chosen as a sensible parameter and the elongation of the roots was monitored as a function of time. Mitotic index and length of meta-xylem cells were estimated in root apex as an index of cell proliferation and cell expansion activity, respectively. (N.C.)

  20. Ionizing Radiation Dose Due to the Use of Agricultural Fertilizers

    Umisedo, Nancy K.; Okuno, Emico; Medina, Nilberto H.; Colacioppo, Sergio; Hiodo, Francisco Y.

    2008-01-01

    The transference of radionuclides from the fertilizers to/and from soils to the foodstuffs can represent an increment in the internal dose when the vegetables are consumed by the human beings. This work evaluates the contribution of fertilizers to the increase of radiation level in the environment and of dose to the people. Samples of fertilizers, soils and vegetables produced in farms located in the neighbourhood of Sao Paulo city in the State of Sao Paulo, Brazil were analysed through gamma spectroscopy. The values of specific activity of 40 K, 238 U and 232 Th show that there is no significant transference of natural radionuclides from fertilizers to the final product of the food chain. The annual committed effective dose due to the ingestion of 40 K contained in the group of consumed vegetables analysed in this work resulted in the very low value of 0.882 μSv

  1. Radiation exposure on residents due to semipalatinsk nuclear tests

    Takada, J.; Hoshi, M.; Nagatomo, T.

    2000-01-01

    Accumulated external radiation doses for residents near Semipalatinsk nuclear test site of the former USSR are presented as a results of the first study by thermoluminescence technique for bricks sampled at several settlements between 1995 and 1997. The external doses which we evaluated from brick dose were up to ∼100 cGy for resident. The external doses at several points in the center of Semipalatinsk city were ∼60 cGy that was remarkably high comparing with the previously reported value based on the military data. A total of 459 nuclear explosions were conducted by the former Union of Soviet Socialist Republics (USSR) from 1949 to 1989 at the Semipalatinsk nuclear test site (SNTS) Kazakhstan, including 87 atmospheric, 26 on the ground, and 364 underground explosions. Total energy release of about 18 Mt equivalent of trinitrotoluene is eleven hundreds times of Hiroshima atomic bomb. However previous reports concerning the effects of radiation on residents near the SNTS based on data provided by the Defense Department of the former USSR do not have direct experimental data concerning effective equivalent dose. They just measured some doses for particular settlements after some nuclear explosions. These do not indicate integrated dose for the residents due to the whole explosions. The technique of thermoluminescence dosimetry (TLD) which had been successfully applied to the dosimetry on Hiroshima and Nagasaki atomic bombs, enabled us to evaluate accumulated external gamma ray doses at specific places due to whole nuclear explosions in the Semipalatinsk test site. TLD technique is well-established one for not only instantaneous exposure like in A-bombs (Hiroshima and Nagasaki) but also prolonged exposure like in dating. Moreover this technique was applicable for dosimetry study of radioactive fallout as shown in studies of Chernobyl accident. The way of external dose estimation from TLD doses for brick will be discussed in case of radioactive fallout. We will

  2. Radiation doses due to the natural radioactivity in Pakistan marble

    Tufail, M.; Iqbal, M.; Mirza, S.M.

    2000-01-01

    In view of its high potential for containing large amounts of radioactive materials and due to its wide-spread use as construction and facing material worldwide, radiation doses received from the marble used in dwellings have been determined. As a first step, specific activity measurements were made using a NaI(TI) gamma ray spectrometer using the spectrum stripping technique. For the samples studied, the average values of specific activities for 226 Ra, 232 Th and 40 K have been found to be 27, 26 and 58 Bg kg -1 respectively. The mesh-adaptive, volume-integral method based code INGRE (Mirza et al. 1991) gave calculated values of the dose equivalent rates inside the standard room (Tufail et al.,1994) due to 226 Ra, 232 Th and 40 K; these were found to lie between 5-77,12-52 and 1-11 nGy h -1 respectively. The values of whole body dose equivalent rates have been found to lie in the 27-108 nGy h -1 range. As these values are below internationally accepted maximum permissible values, therefore marble available in Pakistan can safely be used in dwellings as a construction material. (author)

  3. The nuisance due to the noise of automobile traffic: An investigation in the neighborhoods of freeways

    Lamure, C.; Bacelon, M.

    1980-01-01

    An inquiry was held among 400 people living near freeways in an attempt to determine the characteristics of traffic noise nuisance. A nuisance index was compiled, based on the answers to a questionnaire. Nuisance expressed in these terms was then compared with the noise level measured on the most exposed side of each building. Correlation between the nuisance indexes and the average noise levels is quite good for dwellings with facades parallel to the freeway. At equal noise levels on the most exposed side, the nuisance given for these latter dwellings is lower than for others.

  4. Synchronization of two Hodgkin-Huxley neurons due to internal noise

    Casado, Jose Manuel

    2003-01-01

    It is well known that a strong coupling can synchronize a population of nonlinear oscillators. This fact has deep implications for the current understanding of information processing by the brain. The focus of this Letter is on the role of conductance noise on a system of two coupled Hodgkin-Huxley neurons in the so-called excitable region, where both neurons are at rest in the absence of noise. It is shown that, in this region, conductance noise allows the neurons to achieve both frequency and phase synchronization. This suggests that internal noise could play a role in the emergence of synchronous neural activity in populations of weakly coupled neurons

  5. The effect of floating deck structures on underwater radiated noise

    Bosschaart, C.; Jansen, H.W.; Jong, C.A.F. de; Basten, T.

    2017-01-01

    A concept for underwater machinery noise mitigation of future civil and military ships is the application of a common deck structure, supporting multiple machines, which is installed on resilient mounts on the ship's foundation structure. TNO is addressing the availability and testing of tools to be

  6. Modeling gamma radiation dose in dwellings due to building materials.

    de Jong, Peter; van Dijk, Willem

    2008-01-01

    A model is presented that calculates the absorbed dose rate in air of gamma radiation emitted by building materials in a rectangular body construction. The basis for these calculations is formed by a fixed set of specific absorbed dose rates (the dose rate per Bq kg(-1) 238U, 232Th, and 40K), as determined for a standard geometry with the dimensions 4 x 5 x 2.8 m3. Using the computer codes Marmer and MicroShield, correction factors are assessed that quantify the influence of several room and material related parameters on the specific absorbed dose rates. The investigated parameters are the position in the construction; the thickness, density, and dimensions of the construction parts; the contribution from the outer leave; the presence of doors and windows; the attenuation by internal partition walls; the contribution from building materials present in adjacent rooms; and the effect of non-equilibrium due to 222Rn exhalation. To verify the precision, the proposed method is applied to three Dutch reference dwellings, i.e., a row house, a coupled house, and a gallery apartment. The averaged difference with MCNP calculations is found to be 4%.

  7. Prediction of interior noise due to random acoustic or turbulent boundary layer excitation using statistical energy analysis

    Grosveld, Ferdinand W.

    1990-01-01

    The feasibility of predicting interior noise due to random acoustic or turbulent boundary layer excitation was investigated in experiments in which a statistical energy analysis model (VAPEPS) was used to analyze measurements of the acceleration response and sound transmission of flat aluminum, lucite, and graphite/epoxy plates exposed to random acoustic or turbulent boundary layer excitation. The noise reduction of the plate, when backed by a shallow cavity and excited by a turbulent boundary layer, was predicted using a simplified theory based on the assumption of adiabatic compression of the fluid in the cavity. The predicted plate acceleration response was used as input in the noise reduction prediction. Reasonable agreement was found between the predictions and the measured noise reduction in the frequency range 315-1000 Hz.

  8. Improvement of road noise by reduction of acoustic radiation from body panels; Panel no hoshaon teigen ni yoru road noise no kaizen

    Kamura, T; Utsunomiya, A; Sugihara, T; Tobita, K [Mazda Motor Corp., Hiroshima (Japan)

    1997-10-01

    This paper describes road noise reduction methods accomplished by reducing acoustic power radiated from body panels. Fundamental study of acoustic and dynamic characteristics with rectangular panels revealed following results: (1) The lower stiffness panel had lower radiation efficiency and made damping materials work more effective to reduce the acoustic power. (2) The acoustic power was also reduced by designing the panel so that it can generate the vibration of (2, 2) mode, which has the lowest radiation efficiency, in road noise frequency region. By applying these methods to a vehicle floor, we confirmed the improvement of road noise performance. 3 refs., 12 figs.

  9. Thyroid cancer due to biological effects of ionizing radiation

    Galvão, T.; Castro, N.; Teixeira, D.; Matuo, R.

    2017-01-01

    Thyroid cancer is considered the most common in the region of the head and neck. It can be caused by spontaneous mutations, but also by ionizing radiation. The effect of ionizing radiation on the thyroid has been studied for several decades. The exact cause of the cancer is not known, but people with certain risk factors are more vulnerable, such as exposure to radiation, family history and age over 40 years. The thyroid is susceptible to the effects of radiation and is involved in the field of diagnostic or therapeutic irradiation, and may present functional and structural changes. Radiation can act in different ways, such as inhibiting or activating specific functions of the follicular epithelium, reducing the number of functioning follicles, altering vascularization or vascular permeability and inducing immune reactions. These morphological and histological changes may be related to the development of thyroid cancer

  10. Measurement of the noise components in the medical x-ray intensity pattern due to overlaying nonrecognizable structures

    Tischenko, Oleg; Hoeschen, Christoph; Effenberger, Olaf; Reissberg, Steffen; Buhr, Egbert; Doehring, Wilfried

    2003-06-01

    There are many aspects that influence and deteriorate the detection of pathologies in X-ray images. Some of those are due to effects taking place in the stage of forming the X-ray intensity pattern in front of the x-ray detector. These can be described as motion blurring, depth blurring, anatomical background, scatter noise and structural noise. Structural noise results from an overlapping of fine irrelevant anatomical structures. A method for measuring the combined effect of structural noise and scatter noise was developed and will be presented in this paper. This method is based on the consideration that within a pair of projections created after rotation of the object with a small angle (which is within the typical uncertainty in positioning the patient) both images would show the same relevant structures whereas the projection of the fine overlapping structures will appear quite differently in the two images. To demonstrate the method two X-ray radiographs of a lung phantom were produced. The second radiograph was achieved after rotating the lung by an angle of about 3. Dyadic wavelet representations of both images were regarded. For each value of the wavelet scale parameter the corresponding pair of approximations was matched using the cross correlation matching technique. The homologous regions of approximations were extracted. The image containing only those structures that appear in both images simultaneously was then reconstructed from the wavelet coefficients corresponding to the homologous regions. The difference between one of the original images and the noise-reduced image contains the structural noise and the scatter noise.

  11. The law concerning prevention from radiation hazards due to radioisotopes

    1984-01-01

    The law regulates uses, sales and disposal of radioisotopes, uses of radiation generating apparatuses, disposal of materials contaminated with radioisotopes, and so on, in accordance with the Atomic Energy Fundamental Act, for public safety. Covered are the following: permission for and notification of the uses and permission for businesses selling and disposing of radioisotopes, and approval of designs concerning radiation hazard prevention mechanisms, obligations of the users and business enterprises selling and disposing of radioisotopes, the licensed engineers of radiation, organs, etc. for confirmation of the mechanisms, punitive provisions, and so on. (Mori, K.)

  12. Image noise reduction technology reduces radiation in a radial-first cardiac catheterization laboratory

    Gunja, Ateka; Pandey, Yagya [Department of Veterans Affairs, Jesse Brown VA Medical Center, Chicago, IL (United States); Division of Cardiology, Department of Medicine, University of Illinois at Chicago, Chicago, IL (United States); Xie, Hui [Division of Epidemiology and Biostatistics, University of Illinois at Chicago, Chicago, IL (United States); Faculty of Health Sciences, Simon Fraser University, Burnaby, BC (Canada); Wolska, Beata M. [Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL (United States); Shroff, Adhir R.; Ardati, Amer K. [Department of Veterans Affairs, Jesse Brown VA Medical Center, Chicago, IL (United States); Division of Cardiology, Department of Medicine, University of Illinois at Chicago, Chicago, IL (United States); Vidovich, Mladen I., E-mail: miv@uic.edu [Department of Veterans Affairs, Jesse Brown VA Medical Center, Chicago, IL (United States); Division of Cardiology, Department of Medicine, University of Illinois at Chicago, Chicago, IL (United States)

    2017-04-15

    Background: Transradial coronary angiography (TRA) has been associated with increased radiation doses. We hypothesized that contemporary image noise reduction technology would reduce radiation doses in the cardiac catheterization laboratory in a typical clinical setting. Methods and results: We performed a single-center, retrospective analysis of 400 consecutive patients who underwent diagnostic and interventional cardiac catheterizations in a predominantly TRA laboratory with traditional fluoroscopy (N = 200) and a new image noise reduction fluoroscopy system (N = 200). The primary endpoint was radiation dose (mGy cm{sup 2}). Secondary endpoints were contrast dose, fluoroscopy times, number of cineangiograms, and radiation dose by operator between the two study periods. Radiation was reduced by 44.7% between the old and new cardiac catheterization laboratory (75.8 mGy cm{sup 2} ± 74.0 vs. 41.9 mGy cm{sup 2} ± 40.7, p < 0.0001). Radiation was reduced for both diagnostic procedures (45.9%, p < 0.0001) and interventional procedures (37.7%, p < 0.0001). There was no statistically significant difference in radiation dose between individual operators (p = 0.84). In multivariate analysis, radiation dose remained significantly decreased with the use of the new system (p < 0.0001) and was associated with weight (p < 0.0001), previous coronary artery bypass grafting (p < 0.0007) and greater than 3 stents used (p < 0.0004). TRA was used in 90% of all cases in both periods. Compared with a transfemoral approach (TFA), TRA was not associated with higher radiation doses (p = 0.20). Conclusions: Image noise reduction technology significantly reduces radiation dose in a contemporary radial-first cardiac catheterization clinical practice. - Highlights: • Radial arterial access has been associated with higher doses compared to femoral access. • In a radial-first cardiac catheterization laboratory (90% radial) we examined radiation doses reduction with a contemporary image-noise

  13. Image noise reduction technology reduces radiation in a radial-first cardiac catheterization laboratory

    Gunja, Ateka; Pandey, Yagya; Xie, Hui; Wolska, Beata M.; Shroff, Adhir R.; Ardati, Amer K.; Vidovich, Mladen I.

    2017-01-01

    Background: Transradial coronary angiography (TRA) has been associated with increased radiation doses. We hypothesized that contemporary image noise reduction technology would reduce radiation doses in the cardiac catheterization laboratory in a typical clinical setting. Methods and results: We performed a single-center, retrospective analysis of 400 consecutive patients who underwent diagnostic and interventional cardiac catheterizations in a predominantly TRA laboratory with traditional fluoroscopy (N = 200) and a new image noise reduction fluoroscopy system (N = 200). The primary endpoint was radiation dose (mGy cm"2). Secondary endpoints were contrast dose, fluoroscopy times, number of cineangiograms, and radiation dose by operator between the two study periods. Radiation was reduced by 44.7% between the old and new cardiac catheterization laboratory (75.8 mGy cm"2 ± 74.0 vs. 41.9 mGy cm"2 ± 40.7, p < 0.0001). Radiation was reduced for both diagnostic procedures (45.9%, p < 0.0001) and interventional procedures (37.7%, p < 0.0001). There was no statistically significant difference in radiation dose between individual operators (p = 0.84). In multivariate analysis, radiation dose remained significantly decreased with the use of the new system (p < 0.0001) and was associated with weight (p < 0.0001), previous coronary artery bypass grafting (p < 0.0007) and greater than 3 stents used (p < 0.0004). TRA was used in 90% of all cases in both periods. Compared with a transfemoral approach (TFA), TRA was not associated with higher radiation doses (p = 0.20). Conclusions: Image noise reduction technology significantly reduces radiation dose in a contemporary radial-first cardiac catheterization clinical practice. - Highlights: • Radial arterial access has been associated with higher doses compared to femoral access. • In a radial-first cardiac catheterization laboratory (90% radial) we examined radiation doses reduction with a contemporary image-noise compared to

  14. Spiral waves in excitable media due to noise and periodic forcing

    Yuan Guoyong, E-mail: g-y-yuan@sohu.com [Department of Physics, Hebei Normal University, Shijiazhuang 050016 (China); Hebei Advanced Thin Films Laboratory, Shijiazhuang 050016 (China); Xu Lin [Department of Physics, Hebei Normal University, Shijiazhuang 050016 (China); Xu Aiguo; Wang Guangrui [Institute of Applied Physics and Computational Mathematics, P.O. Box 8009, Beijing 100088 (China); Yang Shiping [Department of Physics, Hebei Normal University, Shijiazhuang 050016 (China); Hebei Advanced Thin Films Laboratory, Shijiazhuang 050016 (China)

    2011-09-15

    Highlights: > Excitable media jointly driven by periodic forcing and Gaussian white noise. > The joint driving leads to many unique tip motions. > New type of spiral wave breakup occurs between entrainment bands with 1:1 and 2:1. > Arnold tongues for different noise intensities exhibit stochastic resonance. > Fourier spectrum analysis can interpret tip motions and formation of entrainments. - Abstract: We investigate the jointly driven effects of external periodic forcing and Gaussian white noise on meandering spiral waves in excitable media with FitzHugh-Nagumo local dynamics. Interesting phenomena resulted from various forcing periods are found, for example, piece-wise line drift, intermittent straight-line drift and so on. We also observe new type of breakup of spiral wave between entrainment bands with 1:1 and 2:1. It is believed that the occurrence of the new type is relevant to the appearance of local bidirectional propagation window. There exist optimized noise intensities which can induce the broadest entrainments and Arnold tongues. Such a phenomenon is referred to as stochastic resonance. It is also observed that the noise makes significant effects on the spiral wave with straight-line drift. Via the tip Fourier spectrum, the varying of tip motion with external periods on the resonance band is interpreted.

  15. Investigation on Flow-Induced Noise due to Backflow in Low Specific Speed Centrifugal Pumps

    Qiaorui Si

    2013-01-01

    Full Text Available Flow-induced noise causes disturbances during the operation of centrifugal pumps and also affects their performance. The pumps often work at off-design conditions, mainly at part-load conditions, because of frequent changes in the pump device system. Consequently numerous unstable phenomena occur. In low specific speed centrifugal pumps the main disturbance is the inlet backflow, which is considered as one of the most important factors of flow-induced noise and vibration. In this study, a test rig of the flow-induced noise and vibration of the centrifugal pump was built to collect signals under various operating conditions. The three-dimensional unsteady flow of centrifugal pumps was calculated based on the Reynolds-averaged equations that resemble the shear stress transport (SST k-ω turbulence model. The results show that the blade passing frequency and shaft frequency are dominant in the spectrum of flow-induced noise, whereas the shaft component, amplitude value at shaft frequency, and peak frequencies around the shaft increase with decreasing flow. Through flow field analysis, the inlet backflow of the impeller occurs under 0.7 times the design flow. The pressure pulsation spectrum with backflow conditions validates the flow-induced noise findings. The velocity characteristics of the backflow zone at the inlet pipe were analyzed, and the dynamic characteristics of the backflow eddy during one impeller rotating period were simultaneously obtained by employing the backflow conditions. A flow visualization experiment was performed to confirm the numerical calculations.

  16. Epidemiology of cancer due to radiations and development of guidelines

    Okuno, Emico

    2009-01-01

    This review article describes the ionizing and non-ionizing radiation protection commissions and the development processes of the guidelines for limiting exposure to these radiations. We briefly describe the history of these commissions and the types of epidemiological studies from which the risk factors are evaluated. Some recent results obtained from epidemiological studies of atomic bomb survivors in Japan and the inherent difficulties will be presented. At last the current international recommendations will be presented. (author)

  17. The law concerning prevention from radiation hazards due to radioisotopes

    1977-01-01

    Based on the gist of the Atomic Energy Basic Law (Law No. 186, 1955), this Law regulates the use, sale, disposal and other handling of radioactive isotopes, use of radiation-generating apparatuses, disposal and other handling of matters contaminated by radioactive isotopes, thereby aims at the prevention of radiation injuries and securing the safety of the public. The radioactive isotopes referred to in this Law are the isotopes emitting radiation such as phosphorus-32 and cobalt-60, their compounds, and those containing such isotopes and compounds. The radiation-generating apparatuses referred to in this Law are the apparatuses generating radiation by accelerating charged particles such as cyclotron and synchrotron. Those who want to use the radioactive isotopes and radiation-generating apparatuses must file applications and obtain approval of the Director of the Science and Technology Agency. Those who want to use sealed radioactive isotopes of the amount less than that stipulated by the Cabinet Order, those who want to sell and those who want to dispose of radioactive isotopes or matters contaiminated thereby as occupation should file notices and obtain approval of the Director of the Science and Technology Agency. Said Director should not approve such notices unless they meet the required specification, and when he approves such notices, he issues licenses. (Rikitake, Y.)

  18. Variability of the contrail radiative forcing due to crystal shape

    Markowicz, K. M.; Witek, M. L.

    2011-12-01

    The aim of this study is to examine the influence of particles' shape and particles' optical properties on the contrail radiative forcing. Contrail optical properties in the shortwave and longwave range are derived using a ray-tracing geometric method and the discrete dipole approximation method, respectively. Both methods present good correspondence of the single scattering albedo and the asymmetry parameter in a transition range (3-7μm). We compare optical properties defined following simple 10 crystals habits randomly oriented: hexagonal plates, hexagonal columns with different aspect ratio, and spherical. There are substantial differences in single scattering properties between ten crystal models investigated here (e.g. hexagonal columns and plates with different aspect ratios, spherical particles). The single scattering albedo and the asymmetry parameter both vary up to 0.1 between various crystal shapes. Radiative forcing calculations were performed using a model which includes an interface between the state-of-the-art radiative transfer model Fu-Liou and databases containing optical properties of the atmosphere and surface reflectance and emissivity. This interface allows to determine radiative fluxes in the atmosphere and to estimate the contrail radiative forcing for clear- and all-sky (including natural clouds) conditions for various crystal shapes. The Fu-Liou code is fast and therefore it is suitable for computing radiative forcing on a global scale. At the same time it has sufficiently good accuracy for such global applications. A noticeable weakness of the Fu-Liou code is that it does not take into account the 3D radiative effects, e.g. cloud shading and horizontal. Radiative transfer model calculations were performed at horizontal resolution of 5x5 degree and time resolution of 20 min during day and 3 h during night. In order to calculate a geographic distribution of the global and annual mean contrail radiative forcing, the contrail cover must be

  19. [FEDERAL CLINICAL RECOMMENDATIONS IN DIAGNOSIS, TREATMENT AND PREVENTION OF HEARING LOSS DUE TO NOISE].

    Adeninskaya, E E; Bukhtiarov, I V; Bushmanov, A Iu; Dayhes, N A; Denisov, E I; Izmerov, N F; Mazitova, N N; Pankova, V B; Preobrazhenskaya, E A; Prokopenko, L V; Simonova, N I; Tavartkiladze, G A; Fedina, I N

    2016-01-01

    Noise induced hearing loss is a slowly developing hearing impairment, caused by occupational exposure to excessive noise levels, constitutes a lesion of the auditory analyzer and clinically manifested as chronic bilateral sensorineural hearing loss. Currently, there is not a treatment that provide a cure of sensorineural hearing loss. Regular, individually tailored treatment should be directed to the pathogenic mechanisms and specific clinical symptoms of hearing loss, as well as the prevention of complications. We recommend using non-drug therapies that can improve blood flow in labyrinth, tissue and cellular metabolism.

  20. Signal and noise analysis of a-Si:H radiation detector-amplifier system

    Cho, Gyuseong.

    1992-03-01

    Hydrogenated amorphous silicon (a-Si:H) has potential advantages in making radiation detectors for many applications because of its deposition capability on a large-area substrate and its high radiation resistance. Position-sensitive radiation detectors can be made out of a 1d strip or a 2-d pixel array of a Si:H pin diodes. In addition, signal processing electronics can be made by thin-film transistors on the same substrate. The calculated radiation signal, based on a simple charge collection model agreed well with results from various wave length light sources and 1 MeV beta particles on sample diodes. The total noise of the detection system was analyzed into (a) shot noise and (b) 1/f noise from a detector diode, and (c) thermal noise and (d) 1/f noise from the frontend TFT of a charge-sensitive preamplifier. the effective noise charge calculated by convoluting these noise power spectra with the transfer function of a CR-RC shaping amplifier showed a good agreement with the direct measurements of noise charge. The derived equations of signal and noise charge can be used to design an a-Si:H pixel detector amplifier system optimally. Signals from a pixel can be readout using switching TFTs, or diodes. Prototype tests of a double-diode readout scheme showed that the storage time and the readout time are limited by the resistances of the reverse-biased pixel diode and the forward biased switching diodes respectively. A prototype charge-sensitive amplifier was made using poly-Si TFTs to test the feasibility of making pixel-level amplifiers which would be required in small-signal detection. The measured overall gain-bandwidth product was ∼400 MHz and the noise charge ∼1000 electrons at a 1 μsec shaping time. When the amplifier is connected to a pixel detector of capacitance 0.2 pF, it would give a charge-to-voltage gain of ∼0.02 mV/electron with a pulse rise time less than 100 nsec and a dynamic range of 48 dB

  1. Signal and noise analysis of a-Si:H radiation detector-amplifier system

    Cho, Gyuseong [Univ. of California, Berkeley, CA (United States)

    1992-03-01

    Hydrogenated amorphous silicon (a-Si:H) has potential advantages in making radiation detectors for many applications because of its deposition capability on a large-area substrate and its high radiation resistance. Position-sensitive radiation detectors can be made out of a 1d strip or a 2-d pixel array of a Si:H pin diodes. In addition, signal processing electronics can be made by thin-film transistors on the same substrate. The calculated radiation signal, based on a simple charge collection model agreed well with results from various wave length light sources and 1 MeV beta particles on sample diodes. The total noise of the detection system was analyzed into (a) shot noise and (b) 1/f noise from a detector diode, and (c) thermal noise and (d) 1/f noise from the frontend TFT of a charge-sensitive preamplifier. the effective noise charge calculated by convoluting these noise power spectra with the transfer function of a CR-RC shaping amplifier showed a good agreement with the direct measurements of noise charge. The derived equations of signal and noise charge can be used to design an a-Si:H pixel detector amplifier system optimally. Signals from a pixel can be readout using switching TFTs, or diodes. Prototype tests of a double-diode readout scheme showed that the storage time and the readout time are limited by the resistances of the reverse-biased pixel diode and the forward biased switching diodes respectively. A prototype charge-sensitive amplifier was made using poly-Si TFTs to test the feasibility of making pixel-level amplifiers which would be required in small-signal detection. The measured overall gain-bandwidth product was ~400 MHz and the noise charge ~1000 electrons at a 1 μsec shaping time. When the amplifier is connected to a pixel detector of capacitance 0.2 pF, it would give a charge-to-voltage gain of ~0.02 mV/electron with a pulse rise time less than 100 nsec and a dynamic range of 48 dB.

  2. Signal and noise analysis of a-Si:H radiation detector-amplifier system

    Cho, Gyuseong.

    1992-03-01

    Hydrogenated amorphous silicon (a-Si:H) has potential advantages in making radiation detectors for many applications because of its deposition capability on a large-area substrate and its high radiation resistance. Position-sensitive radiation detectors can be made out of a 1d strip or a 2-d pixel array of a Si:H pin diodes. In addition, signal processing electronics can be made by thin-film transistors on the same substrate. The calculated radiation signal, based on a simple charge collection model agreed well with results from various wave length light sources and 1 MeV beta particles on sample diodes. The total noise of the detection system was analyzed into (a) shot noise and (b) 1/f noise from a detector diode, and (c) thermal noise and (d) 1/f noise from the frontend TFT of a charge-sensitive preamplifier. the effective noise charge calculated by convoluting these noise power spectra with the transfer function of a CR-RC shaping amplifier showed a good agreement with the direct measurements of noise charge. The derived equations of signal and noise charge can be used to design an a-Si:H pixel detector amplifier system optimally. Signals from a pixel can be readout using switching TFTs, or diodes. Prototype tests of a double-diode readout scheme showed that the storage time and the readout time are limited by the resistances of the reverse-biased pixel diode and the forward biased switching diodes respectively. A prototype charge-sensitive amplifier was made using poly-Si TFTs to test the feasibility of making pixel-level amplifiers which would be required in small-signal detection. The measured overall gain-bandwidth product was {approximately}400 MHz and the noise charge {approximately}1000 electrons at a 1 {mu}sec shaping time. When the amplifier is connected to a pixel detector of capacitance 0.2 pF, it would give a charge-to-voltage gain of {approximately}0.02 mV/electron with a pulse rise time less than 100 nsec and a dynamic range of 48 dB.

  3. Active control of noise radiation from vibrating structures

    Mørkholt, Jakob

    developed, based on the theory of radiation filters for estimating the sound radiation from multimodal vibrations. This model has then been used in simulations of optimal feedback control, with special emphasis of the stability margins of the optimal control scheme. Two different methods of designing...... optimal and robust discrete-time feedback controllers for active vibration control of multimodal structures have been compared. They have been showed to yield controllers with identical frequency response characteristics, even though they employ completely different methods of numerical solutions...... and result in different representations of the controllers. The Internal Model Control structure combined with optimal filtering is suggested as an alternative to state space optimal control techniques for designing robust optimal controllers for audio frequency vibration control of resonant structures....

  4. RF fields due to Schottky noise in a coasting particle beam

    Faltin, L

    1977-01-01

    The RF fields inside a rectangular chamber excited by the Schottky noise current inherently present in a coasting particle beam are calculated, using a simple beam model. Vertical betatron oscillations are assumed. The power flow accompanying the beam is given as well as the resulting characteristic impedance. Numerical results are presented.

  5. Radiation exposure of the population due to medical procedures

    Frischauf, H.

    1976-01-01

    The question of individual benefit-risk ratio in X-ray exposures is considered. The growth rate of the number of radiological examinations in New Zealand, Sweden, UK and USA is stated to be between 2 and 6 per cent per annum. The risks of internal radioisotope tests are emphasised and reductions of exposure are reported when 99Tc isotopes are used, counterbalanced by the increasing number of exposures made; the question of radiation-induced leukemia is raised in this respect. The problems of analysing delayed radiation effects are discussed, and the possibility of animal tests is suggested. (G.M.E.)

  6. Osteonecrosis due to radiation given for uterus cervical cancer

    Morimoto, Kazuo; Ugai, Kazuhiro; Hasegawa, Kazuo; Hirota, Saeko [Hyogo Medical Center for Adults, Akashi (Japan)

    1992-04-01

    During a period 1984-1991, 18 patients were diagnosed as developing osteonecrosis after radiation therapy for uterine cervical cancer. The patients had Stage I-III. Acute pain occurred in the lumbar spine, pelvis, and/or limbs. There was no correlation between osteonecrosis and either clinical staging or the associated surgery. The most common site of osteonecrosis was lumbar spine (n=13), followed by sacroiliacal joint and head and neck of femur (5 each) and pubic bone (3). The duration from radiation therapy to occurrence of osteonecrosis varied from one to 8 years: the latency period tended to be longer for younger patients. There was correlation between radiation doses and site of osteonecrosis: 60 Gy caused more extensive osteonecrosis, involving the pelvis and head of femur, although 40 Gy confined it to the lumbo-sacral region. Osteonecrosis was sometimes difficult to diagnose: needle biopsy, in addition to imaging modalities, was necessary in 4 patients. It is recommended that patients with uterus cervical cancer treated with radiation be followed up carefully. (N.K.).

  7. Analytical investigation of adaptive control of radiated inlet noise from turbofan engines

    Risi, John D.; Burdisso, Ricardo A.

    1994-01-01

    An analytical model has been developed to predict the resulting far field radiation from a turbofan engine inlet. A feedforward control algorithm was simulated to predict the controlled far field radiation from the destructive combination of fan noise and secondary control sources. Numerical results were developed for two system configurations, with the resulting controlled far field radiation patterns showing varying degrees of attenuation and spillover. With one axial station of twelve control sources and error sensors with equal relative angular positions, nearly global attenuation is achieved. Shifting the angular position of one error sensor resulted in an increase of spillover to the extreme sidelines. The complex control inputs for each configuration was investigated to identify the structure of the wave pattern created by the control sources, giving an indication of performance of the system configuration. It is deduced that the locations of the error sensors and the control source configuration are equally critical to the operation of the active noise control system.

  8. Effective dose equivalents from external radiation due to Chernobyl accident

    Erkin, V.G.; Debedev, O.V.; Balonov, M.I.; Parkhomenko, V.I.

    1992-01-01

    Summarized data on measurements of individual dose of external γ-sources in 1987-1990 of population of western areas of Bryansk region were presented. Type of distribution of effective dose equivalent, its significance for various professional and social groups of population depending on the type of the house was discussed. Dependences connecting surface soil activity in the populated locality with average dose of external radiation sources were presented. Tendency of dose variation in 1987-1990 was shown

  9. Radiation exposure of patients due to medical measures

    Schwarz, E.R.; Tsavachidis, C.; Hinz, G.; Eigelsreiter, H.

    1987-01-01

    The main objective of this research project supported by the Federal Ministry of the Interior was to collect the data required as a basis for an up-to-date assessment of the radiation exposure of the population as a result of medical measures. Apart from the fact that this had to be done in order to fulfill a commitment required by the EURATOM principles, the report in hand also presents a useful survey of the improvements achieved over the last years in terms of radiation hygiene in the field of imaging technology applied for medical diagnostics. The data obtained from four hospital centers (2 university hospitals, 1 city hospital, and one county hospital) and from three medical practices (radiologist, internal specialist, orthopedics), the changes experienced in the selection of imaging methods for diagnostic purposes in the period 1976 to 1983 or 1985 are illustrated, and analyses show the developmental trends. The results show that there is reason to assume the radiation exposure of the population to be receding. (orig./MG) [de

  10. Changes in bacterial radiation sensitivity due to deuterium substitution

    Strauss, A.; Weiss, H.

    1985-01-01

    The influence of deuterium substitution for hydrogen on radiation sensitivity was measured under various conditions for E. coli B/r irradiated by 450 kev electrons in single intense pulses. Cells were grown in a nutrient medium made from a deuterium oxide based solution. They were suspended in a D/sub 2/O based buffered saline and plated in thin aqueous layers on membrane filters and irradiated in 100% N/sub 2/ or 100% O/sub 2/. Comparisons were made to cells similarly plated and irradiated but grown instead in a water based nutrient medium and suspended in either a water based or a D/sub 2/O based buffered saline. For the conventionally grown cells, D/sub 2/O increased the radiation sensitivity in both gases by about 10%. For cells grown and suspended with D/sub 2/O based media, a 50% reduction of radiation sensitivity was found with both gas and an increased extrapolation number was observed. In this latter method, deuterium is more fully substituted for hydrogen in the molecular substrate of the cell. These cells were also irradiated over a temperature range of 2 0 C to 43 0 C after being suspended in deuterated ethanol. Speculations for the changes induced by the substitution are presented

  11. Resonance-Based Time-Frequency Manifold for Feature Extraction of Ship-Radiated Noise

    Yan, Jiaquan; Sun, Haixin; Chen, Hailan; Junejo, Naveed Ur Rehman; Cheng, En

    2018-01-01

    In this paper, a novel time-frequency signature using resonance-based sparse signal decomposition (RSSD), phase space reconstruction (PSR), time-frequency distribution (TFD) and manifold learning is proposed for feature extraction of ship-radiated noise, which is called resonance-based time-frequency manifold (RTFM). This is suitable for analyzing signals with oscillatory, non-stationary and non-linear characteristics in a situation of serious noise pollution. Unlike the traditional methods which are sensitive to noise and just consider one side of oscillatory, non-stationary and non-linear characteristics, the proposed RTFM can provide the intact feature signature of all these characteristics in the form of a time-frequency signature by the following steps: first, RSSD is employed on the raw signal to extract the high-oscillatory component and abandon the low-oscillatory component. Second, PSR is performed on the high-oscillatory component to map the one-dimensional signal to the high-dimensional phase space. Third, TFD is employed to reveal non-stationary information in the phase space. Finally, manifold learning is applied to the TFDs to fetch the intrinsic non-linear manifold. A proportional addition of the top two RTFMs is adopted to produce the improved RTFM signature. All of the case studies are validated on real audio recordings of ship-radiated noise. Case studies of ship-radiated noise on different datasets and various degrees of noise pollution manifest the effectiveness and robustness of the proposed method. PMID:29565288

  12. Observation of Synchrotron Radiation Using Low Noise Block (LNB) at ANKA

    Judin, V; Hofmann, A; Huttel, E; Kehrer, B; Klein, M; Marsching, S; Muller, A-S; Smale, N; Caspers, F

    2011-01-01

    Generally Coherent Synchrotron Radiation (CSR) is emitted for wavelengths longer than or equal the bunch length, so for CSR in the THz-range short bunches are required. There are two types of detectors in this range of the spectrum: slow detectors like a golay cell or pyrometric detectors (used for e.g. imaging, spectroscopy) and fast detectors like superconducting bolometer detector systems and Schottky Barrier diodes (used for e.g. the investigation of dynamic processes in accelerator physics). The hot electron bolometer (HEB) detector system is a member of second group. It is very fast and has broad spectral characteristics, but unfortunately very expensive and have to be cooled using liquid helium. If the broad spectral response is not important, it will be suitably to use a Schottky Barrier diode instead. These detectors are massively cheaper but also slower. As an alternative to a Schottky diode a LNB (Low Noise Block) can be also used. It is usually used in standard TV-SAT-receivers. Due to mass produc...

  13. An Experimental Study on the Radiation Noise Characteristics of a Centrifugal Pump with Various Working Conditions

    Chang Guo

    2017-12-01

    Full Text Available To investigate the radiation noise characteristics of a centrifugal pump under various working conditions, a noise measurement system is established; afterwards, the distribution of different points and intervals, as well as the overall level of noise, are studied. The total sound pressure level distribution for different points manifests the dipole and asymmetric directivity characteristics. Additionally, the acoustic energy is introduced to compare the noise of different intervals to reveal the asymmetric characteristics, and it is found that variation in working conditions has little impact on the acoustic energy distribution, and the ratio of the acoustic energy in the direction facing the tongue, as well as that in the direction against the tongue, to total acoustic energy fluctuate around 0.410 and 0.160, respectively, under various working conditions. Also, the A-weighted average sound pressure level (LpA is applied to describe the overall level of noise, and LpA increases gradually with the growth of rotational speed, but the growth slope decreases. While in the operation of throttling regulation, LpA shows the trend that first increases, then remains stable, and increases again with the growth of flow rate. This study could provide guidance for optimizing the operating conditions and noise control of centrifugal pumps.

  14. Detriment due to radiation exposure: concept and assessment

    Inaba, Jiro

    1999-01-01

    The International Commission on Radiological Protection has used a term risk' to denote the probability of a clinically observable deleterious effect such as fatal cancers and severe hereditary effects. In their 1990 recommendations ICRP developed a new term 'detriment' which contains a complex concept combining the probability, severity and time of expression of deleterious effects. Nominal probability coefficients for fatal cancer, one of the most important components of the detriment, are assessed to be 5% and 4% per Sv for the whole population and workers, respectively, for radiation protection. These values were derived from the data on mortality from the Life-Span Study of the atomic-bomb survivors up to 1985 assuming several components consist of dose-response relationship, life-span risk projection model, dose and dose rate effectiveness factor, national population and transfer model and so on. The risk estimates and each of these components include uncertainties which should be clarified for the better understanding and use of the risk estimates. However, it is not likely that near-future data from Life-Span Study will significantly change these uncertainties, which should in no way be interpreted as a denial of the essential importance of fundamental research into the mechanism of cancer induction. In these situation the National Institute of Radiological Sciences have performed a 5-year research project 'Experimental Studies on Detriments of Radiation Exposure'. The project consists of researches on a) Radiation carcinogenesis, b) Effects on embryo and fetus, c) Biological effect of plutonium. The project was successful to provide useful information on these subjects. (author)

  15. Constraining the cosmic radiation density due to lepton number

    Mangano, Gianpiero; Miele, Gennaro; Pastor, Sergio; Pisanti, Ofelia; Sarikas, Srdjan

    2013-01-01

    The cosmic energy density in the form of radiation before and during Big Bang Nucleosynthesis is typically parameterized in terms of the effective number of neutrinos N eff , and it is a key parameters in cosmological models slightly more general than the successful minimal ΛCDM scenario. This quantity, in case of no extra degrees of freedom, depends upon the chemical potential and the temperature characterizing the three active neutrino distributions, as well as by their possible non-thermal features. We summarize here the results of a recent analysis to determine the BBN bound on N eff from primordial neutrino–antineutrino asymmetries, with a careful treatment of the dynamics of neutrino oscillations, and considering quite a wide range for the total lepton number in the neutrino sector, η ν =η ν e +η ν μ +η ν τ and the initial electron neutrino asymmetry η ν e in . Comparing these results with the forthcoming measurement of N eff by the Planck satellite will give insight on the nature of the radiation content of the universe

  16. Noise analysis due to strip resistance in the ATLAS SCT silicon strip module

    Kipnis, I.

    1996-08-01

    The module is made out of four 6 cm x 6 cm single sided Si microstrip detectors. Two detectors are butt glued to form a 12 cm long mechanical unit and strips of the two detectors are electrically connected to form 12 cm long strips. The butt gluing is followed by a back to back attachment. The module in this note is the Rφ module where the electronics is oriented parallel to the strip direction and bonded directly to the strips. This module concept provides the maximum signal-to-noise ratio, particularly when the front-end electronics is placed near the middle rather than at the end. From the noise analysis, it is concluded that the worst-case ΔENC (far-end injection) between end- and center-tapped modules will be 120 to 210 el. rms (9 to 15%) for a non-irradiated detector and 75 to 130 el. rms (5 to 9%) for an irradiated detector, for a metal strip resistance of 10 to 20 Ω/cm

  17. Radiation hazard due to radon in indoor air

    Keller, G.

    1987-01-01

    Inhalation of the noble gas radon and its short-lived daughter products present in normal room air causes a considerable increase of the mean natural radiation exposure of the population. As there is an uncontested relationship between lung dose and cancer risk, measures should be taken to guarantee that the radon concentrations in room air do at least not reach maxima. The most simple measure is frequent, brief, good ventilation. Very high radon concentrations are measured in houses where radon pentrates direct from the soil into buildings. For this case, radon-tight insulation of the building from the soil is recommended. A forced ventilation system with heat recovery, installed by experts, has shown to be very successful in radon reduction in 'problematic' houses. (orig.) [de

  18. Occupational radiation exposure of the personnel due to interventional radiology

    Wucherer, M.; Schmidt, T.; Loose, R.

    2000-01-01

    Applications of interventional radiology continue to be on an upward trend, some countries reporting a 100% increase within 2-4 years, so that the resulting radiation exposure of both patients and personnel is an issue of increasing importance. Whereas those applications in general are of advantage for the patients, they mean just a further health hazard for the medical personnel. It is therefore necessary to exploit all available means to reduce the occupational doses. Modern interventional radiology systems offer a range of measures for this purpose, as e.g. last-image-hold, or pulsed modes. Special attention has to be given to the exposure of hand and head. Particularly the hand is closest to the useful beam, and it should be a mandatory requirement to wear film rings. (orig./CB) [de

  19. Years of life lost due to external radiation exposure

    Raicevic, J.J.; Merkle, J.M.; Ehrhardt, J.; Ninkovic, M.M.

    2002-01-01

    A new approach for calculation of the years of life lost per excess death (YLL) due to stochastic health effects is applied to external exposure pathways. The short-term external exposures are due to the passage of radioactive cloud (CL) and due to the skin and clothes contamination (SK). The long-term external exposure is the one from the radioactive material deposited on ground (GR). Three nuclides, 131 I , 137 Cs and 239 Pu with extremely wide range of the half-life are considered to examine its possible influence on the calculated YLL values. For each of these nuclides, the YLL is found as a decreasing function of the age at exposure and presented graphically in this paper. Another negative correlation is established between the fully averaged YLL and the duration of the nuclide's half-life has been found for protracted exposure (GR). On the other hand, the YLL for the short-term external exposures (CL and SK) practically does not depend on the nuclide's half-life. In addition, a weak YLL dependence of the dose was commented. (author)

  20. Years of life lost due to external radiation exposure

    Raičević Jagoš J.

    2004-01-01

    Full Text Available In this paper a new approach for calculation of the years of life lost per excess death due to stochastic health effects is applied to external exposure pathways. The short-term external exposures are due to the passage of radioactive cloud and due to the skin and clothes contamination. The long-term external exposure is the one from the radioactive material deposited on the ground (groundshine. Three nuclides, 131I, 137Cs, and 239Pu, and with the extremely wide range of half-life are considered in order to examine their possible influence on the calculated values of years of life lost. For each of these nuclides, the number of years of life lost has been found as a decreasing function of the age at the expo sure and presented graphically in this paper. For protracted exposures, the fully averaged number of years of life lost is negative correlated with the nuclide’s half-life. On the other hand, the short-term external exposures do not depend on the nuclide’s half-life. In addition, a weak years of life lost dependence of the dose has been commented.

  1. Transition to turbulence and noise radiation in heated coaxial jet flows

    Gloor, Michael, E-mail: gloor@ifd.mavt.ethz.ch; Bühler, Stefan; Kleiser, Leonhard [Institute of Fluid Dynamics, ETH Zurich, 8092 Zurich (Switzerland)

    2016-04-15

    Laminar-turbulent transition and noise radiation of a parametrized set of subsonic coaxial jet flows with a hot primary (core) stream are investigated numerically by Large-Eddy Simulation (LES) and direct noise computation. This study extends our previous research on local linear stability of heated coaxial jet flows by analyzing the nonlinear evolution of initially laminar flows disturbed by a superposition of small-amplitude unstable eigenmodes. First, a baseline configuration is studied to shed light on the flow dynamics of coaxial jet flows. Subsequently, LESs are performed for a range of Mach and Reynolds numbers to systematically analyze the influences of the temperature and the velocity ratios between the primary and the secondary (bypass) stream. The results provide a basis for a detailed analysis of fundamental flow-acoustic phenomena in the considered heated coaxial jet flows. Increasing the primary-jet temperature leads to an increase of fluctuation levels and to an amplification of far-field noise, especially at low frequencies. Strong mixing between the cold bypass stream and the hot primary stream as well as the intermittent character of the flow field at the end of the potential core lead to a pronounced noise radiation at an aft angle of approximately 35{sup ∘}. The velocity ratio strongly affects the shear-layer development and therefore also the noise generation mechanisms. Increasing the secondary-stream velocity amplifies the dominance of outer shear-layer perturbations while the disturbance growth rates in the inner shear layer decrease. Already for r{sub mic} > 40R{sub 1}, where r{sub mic} is the distance from the end of the potential core and R{sub 1} is the core-jet radius, a perfect 1/r{sub mic} decay of the sound pressure amplitudes is observed. The potential-core length increases for higher secondary-stream velocities which leads to a shift of the center of the dominant acoustic radiation in the downstream direction.

  2. Errors due to random noise in velocity measurement using incoherent-scatter radar

    P. J. S. Williams

    1996-12-01

    Full Text Available The random-noise errors involved in measuring the Doppler shift of an 'incoherent-scatter' spectrum are predicted theoretically for all values of Te/Ti from 1.0 to 3.0. After correction has been made for the effects of convolution during transmission and reception and the additional errors introduced by subtracting the average of the background gates, the rms errors can be expressed by a simple semi-empirical formula. The observed errors are determined from a comparison of simultaneous EISCAT measurements using an identical pulse code on several adjacent frequencies. The plot of observed versus predicted error has a slope of 0.991 and a correlation coefficient of 99.3%. The prediction also agrees well with the mean of the error distribution reported by the standard EISCAT analysis programme.

  3. Environmental induced renormalization effects in quantum Hall edge states due to 1/f noise and dissipation

    Braggio, A; Ferraro, D; Sassetti, M; Carrega, M; Magnoli, N

    2012-01-01

    We propose a general mechanism for the renormalization of the tunnelling exponents in edge states of the fractional quantum Hall effect. Mutual effects of the coupling with out-of-equilibrium 1/f noise and dissipation are considered for both the Laughlin sequence and the composite co- and counter-propagating edge states with Abelian or non-Abelian statistics. For states with counter-propagating modes, we demonstrate the robustness of the proposed mechanism in the so-called disorder-dominated phase. Prototypes of these states, such as ν = 2/3 and ν = 5/2, are discussed in detail, and the rich phenomenology induced by the presence of a noisy environment is presented. The proposed mechanism could help justify the strong renormalizations reported in many experimental observations carried out at low temperatures. We show how environmental effects could affect the relevance of the tunnelling excitations, leading to important implications, in particular for the ν = 5/2 case. (paper)

  4. Measurement and Analysis of the Noise Radiated by Low Mach Number Centrifugal Blowers.

    Yeager, David Marvin

    An investigation was performed of the broad band, aerodynamically generated noise in low tip-speed Mach number, centrifugal air moving devices. An interdisciplinary experimental approach was taken which involved investigation of the aerodynamic and acoustic fields, and their mutual relationship. The noise generation process was studied using two experimental vehicles: (1) a scale model of a homologous family of centrifugal blowers typical of those used to cool computer and business equipment, and (2) a single blade from a centrifugal blower impeller placed in a known, controllable flow field. The radiation characteristics of the model blower were investigated by measuring the acoustic intensity distribution near the blower inlet and comparing it with the intensity near the inlet to an axial flow fan. Results showed that the centrifugal blower is a distributed, random noise source, unlike an axial fan which exhibited the effects of a coherent, interacting source distribution. Aerodynamic studies of the flow field in the inlet and at the discharge to the rotating impeller were used to assess the mean flow distribution through the impeller blade channels and to identify regions of excessive turbulence near the rotating blade row. Both circumferential and spanwise mean flow nonuniformities were identified along with a region of increased turbulence just downstream of the scroll cutoff. The fluid incidence angle, normally taken as an indicator of blower performance, was estimated from mean flow data as deviating considerably from an ideal impeller design. An investigation of the noise radiated from the single, isolated airfoil was performed using modern correlation and spectral analysis techniques. Radiation from the single blade in flow was characterized using newly developed expressions for the correlation area and the dipole source strength per unit area, and from the relationship between the blade surface pressure and the incident turbulent flow field. Results

  5. Measurement and analysis of the noise radiated by low Mach numbers centrifugal blowers

    Yeager, D. M.; Lauchle, G. C.

    1987-11-01

    The broad band, aerodynamically generated noise in low tip-speed Mach number, centrifugal air moving devices is investigated. An interdisciplinary approach was taken which involved investigation of the aerodynamic and acoustic fields, and their mutual relationship. The noise generation process was studied using two experimental vehicles: (1) a scale model of a homologous family of centrifugal blowers typical of those used to cool computer and business equipment, and (2) a single blade from a centrifugal blower impeller which was placed in a known, controllable flow field. The radiation characteristics of the model blower were investigated by measuring the acoustic intensity distribution near the blower inlet and comparing it with the intensity near the inlet to an axial flow fan. Aerodynamic studies of the flow field in the inlet and at the discharge to the rotating impeller were used to assess the mean flow distribution through the impeller blade channels and to identify regions of excessive turbulence near the rotating blade row. New frequency-domain expressions for the correlation area and dipole source strength per unit area on a surface immersed in turbulence were developed which can be used to characterize the noise generation process over a rigid surface immersed in turbulence. An investigation of the noise radiated from the single, isolated airfoil (impeller blade) was performed using modern correlation and spectral analysis techniques.

  6. The philosophy and assumptions underlying exposure limits for ionising radiation, inorganic lead, asbestos and noise

    Akber, R.

    1996-01-01

    Full text: A review of the literature relating to exposure to, and exposure limits for, ionising radiation, inorganic lead, asbestos and noise was undertaken. The four hazards were chosen because they were insidious and ubiquitous, were potential hazards in both occupational and environmental settings and had early and late effects depending on dose and dose rate. For all four hazards, the effect of the hazard was enhanced by other exposures such as smoking or organic solvents. In the cases of inorganic lead and noise, there were documented health effects which affected a significant percentage of the exposed populations at or below the [effective] exposure limits. This was not the case for ionising radiation and asbestos. None of the exposure limits considered exposure to multiple mutagens/carcinogens in the calculation of risk. Ionising radiation was the only one of the hazards to have a model of all likely exposures, occupational, environmental and medical, as the basis for the exposure limits. The other three considered occupational exposure in isolation from environmental exposure. Inorganic lead and noise had economic considerations underlying the exposure limits and the exposure limits for asbestos were based on the current limit of detection. All four hazards had many variables associated with exposure, including idiosyncratic factors, that made modelling the risk very complex. The scientific idea of a time weighted average based on an eight hour day, and forty hour week on which the exposure limits for lead, asbestos and noise were based was underpinned by neither empirical evidence or scientific hypothesis. The methodology of the ACGIH in the setting of limits later brought into law, may have been unduly influenced by the industries most closely affected by those limits. Measuring exposure over part of an eight hour day and extrapolating to model exposure over the longer term is not the most effective way to model exposure. The statistical techniques used

  7. Circumvention of radiation-induced noise in CCD and CID imagers

    Yates, G.J.; Turko, B.T.

    1989-01-01

    Measurements of radiation sensitivity for interline transfer charge-injection devices (CIDs) from irradiation with high-energy photons ( 60 Co gammas and 3- to 5-MeV end-point Bremsstrahlung) and 14 MeV neutrons are presented to establish imager susceptibility in such environments. Results from electronic clearing techniques designed for quick (∼300μs for the CCDs and ∼10μs for CIDs) removal (or dumping) of radiation-induced charge from prompt sources are discussed. Application of the techniques coupled with long (microsecond to millisecond) persistence radiation-to-light converters for image retention are described. Typical data illustrating the effectiveness of charge clearing in removal of radiation noise are included for nanosecond duration pulsed x-ray/γ-ray doses (50 millirad to 5-rad range) and microsecond duration neutron fluences approaching 10 8 n/cm 2

  8. On the contribution of a stochastic background of gravitational radiation to the timing noise of pulsars

    Mashhoon, B.

    1982-01-01

    The influence of a stochastic and isotropic background of gravitational radiation on timing measurements of pulsars is investigated, and it is shown that pulsar timing noise may be used to establish a significant upper limit of about 10 to the -10th on the total energy density of very long-wavelength stochastic gravitational waves. This places restriction on the strength of very long wavelength gravitational waves in the Friedmann model, and such a background is expected to have no significant effect on the approximately 3 K electromagnetic background radiation or on the dynamics of a cluster of galaxies.

  9. 210Po radiation dose due to cigarette smoking

    Godwin, Wesley S.; Subha, Vincila R.; Feroz, Khan M.

    2010-01-01

    The level of 210 Po in eight brands of cigarettes and four brands of bidis popular in and around Nagercoil town was determined to evaluate the annual effective dose. The 210 Po activity in a full cigarette ranged from 32.8±3.6 to 68.4±5.9 mBq and from 34.3±3.5 to 62.9±5.8 mBq in a bidi. In tobacco, the highest 210 Po content was recorded in the brand C4 (23.0±1.2 mBq) whereas for bidis it was the highest in the brand B2 (21.1±1.1 mBq). The activity in mainstream varied from 15.2±0.75 to 36.8±2.1 mBq in a cigarette and from 20.7±3.1 to 39.8±4.0 mBq in a bidi. With regard to 210 Po activity concentration, not much specificity was noted with respect to the tobacco brand. The data showed a relatively wide range of activity concentration of 210 Po in the different cigarette/bidi brands and even within the same brand. The bidis showed a higher activity when compared to cigarettes. The popular brands concentrated more activity than the fine brands. Smokers who smoke one pack (10 cigarettes/bidis) per day may inhale about 100-300 mBq d -1 (0.1-0.3 Bq d -1 ) of 210 Po. In this study, radiation dose values in the range of 153.5-372.9 μSv Y - '1 from cigarettes and from 209.2 to 402.7 μSvY -1 from bidis was estimated for the whole body. (author)

  10. Some properties of Cerenkov radiation due to the finite thickness of the radiator

    Kobzev, A.P.; Frank, I.M.

    1981-01-01

    The properties of Cerenkov radiation are analyzed for a small radiator thickness. It is shown that the directionality of the radiation, its threshold properties, and also the dependence on the electron energy and radiator thickness differ substantially from the well known characteristics of Cerenkov radiation corresponding to the case of an unlimited particle trajectory in an extended medium. We have experimentally studied the directionality and energy characteristics of radiation excited by electrons in a mica target of thickness 12 400 A at wavelength 4000 A. The experimental results are in good agreement with the calculations

  11. Radionuclides in food and the radiation exposure due to ingestion

    Michel, Rolf

    2015-01-01

    As a consequence of the reactor accidents in Fukushima Daiichi high amounts of radioactive iodine and cesium isotopes were released into the terrestrial and marine Japanese environment. The largest release occurred on March 15, 2011 as a consequence of the containment failure of unit 2. Due to the meteorological conditions large area fallout occurred in the district of Fukushima. Other prefectures in the north of Japan were also contaminated. As a consequence of the high surface contamination the dose limits for drinking water, milk and milky products and food were increased to 200 Bq/kg.It turned out that the contamination of rice was marginal, the contamination of predatory fish higher than that of non-predatory fish. A systematic investigation of food samples could allow a better estimation of ingestion induced exposure.

  12. Determination of the radiation dose to the body due to external radiation

    Drexler, G.; Eckerl, H.

    1985-01-01

    Section 63 of the Radiation Protection Ordinance defines the basic requirement, determination of radiation dose to the body. The determination of dose equivalents for the body is the basic step in practical monitoring of dose equivalents or dose limits with regard to individuals or population groups, both for constant or varying conditions of exposure. The main field of monitoring activities is the protection of persons occupationally exposed to ionizing radiation. Conversion factors between body doses and radiation quantities are explained. (DG) [de

  13. Risks and radiation doses due to residential radon in Germany

    Beck, T.R.

    2017-01-01

    The population-averaged risk rate and the annual average effective dose due to residential radon in Germany were calculated. The calculations were based on an epidemiological approach taking into account the age- and gender-specific lung cancer incidence rates for the German population and the excess relative risk of 0.16 per 100 Bq.m"-"3 for residential radon. In addition, the risk estimates adjusted for the smoking habits were determined. The population-averaged risk rate for the whole population was estimated with 4.1.10"-"5 y"-"1 (95% confidence interval (CI) 1.4.10"-"5 - 7.6.10"-"5 y"-"1). Residential radon causes a detriment per year of 3.3.10"-"5 y"-"1 (95% CI 1.1.10"-"5 - 6.0.10"-"5 y"-"1), which corresponds to an annual average effective dose of 0.6 mSv (95% CI 0.2-1.1 mSv). Annually, ∼3400 lung cancer incidences are attributed to residential radon. The results from the epidemiological approach exercised in this study are considerably lower than the effective dose, which would be obtained from the dose conversion coefficient calculated using biokinetic and dosimetric models. (author)

  14. Reducing Radiation Dose in Coronary Angiography and Angioplasty Using Image Noise Reduction Technology.

    Kastrati, Mirlind; Langenbrink, Lukas; Piatkowski, Michal; Michaelsen, Jochen; Reimann, Doris; Hoffmann, Rainer

    2016-08-01

    This study sought to quantitatively evaluate the reduction of radiation dose in coronary angiography and angioplasty with the use of image noise reduction technology in a routine clinical setting. Radiation dose data from consecutive 605 coronary procedures (397 consecutive coronary angiograms and 208 consecutive coronary interventions) performed from October 2014 to April 2015 on a coronary angiography system with noise reduction technology (Allura Clarity IQ) were collected. For comparison, radiation dose data from consecutive 695 coronary procedures (435 coronary angiograms and 260 coronary interventions) performed on a conventional coronary angiography system from October 2013 to April 2014 were evaluated. Patient radiation dosage was evaluated based on the cumulative dose area product. Operators and operator practice did not change between the 2 evaluated periods. Patient characteristics were collected to evaluate similarity of patient groups. Image quality was evaluated on a 5-grade scale in 30 patients of each group. There were no significant differences between the 2 evaluated groups in gender, age, weight, and fluoroscopy time (6.8 ± 6.1 vs 6.9 ± 6.3 minutes, not significant). The dose area product was reduced from 3195 ± 2359 to 983 ± 972 cGycm(2) (65%, p technology. Image quality was graded as similar between the evaluated systems (4.0 ± 0.7 vs 4.2 ± 0.6, not significant). In conclusion, a new x-ray technology with image noise reduction algorithm provides a substantial reduction in radiation exposure without the need to prolong the procedure or fluoroscopy time. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Effects induced by γ-radiation on the noise in junction field-effect transistors belonging to monolithic processes

    Manfredi, P.F.; Re, V.; Manfredi, P.F.; Speziali, V.; Re, V.; Manfredi, P.F.; Speziali, V.

    1999-01-01

    The effects of γ-rays on the noise characteristics of junction field-effect transistors belonging to three monolithic technologies have been investigated. A substantially different behavior of the radiation-induced noise in N and P -channel JFETs was observed. This may result in interesting design considerations. (authors)

  16. Effective Dose Equivalent To The Cypriot Population Due To Natural Radiation

    Christofides, S [Medical Physics Department, Nicosia General Hospital (Cyprus)

    1994-12-31

    A study was initiated by the Biomedical Research Foundation, two years ago, to estimate the various natural radiation components that contribute to the Effective Dose Equivalent (EDE) to the Cypriot population. The present study has shown that the contribution due to cosmic radiation is estimated to be less than 270 microSiverts per annum, while that due to airborne Rn-222 concentration in Cypriot houses is estimated to be less then 330 microSieverts per annum. The contribution due to terrestrial gamma radiations, which is currently under investigation, is so far estimated to be around 108 microSieverts per annum. Therefore the EDE to the Cypriot population due to natural radiation is likely to be around 700 microSieverts per annum, not taking into account the internal exposure due to other naturally occuring radionuclides. (author). 7 refs, 4 figs, 4 tabs.

  17. Thermal noise due to surface-charge effects within the Debye layer of endogenous structures in dendrites.

    Poznanski, Roman R

    2010-02-01

    An assumption commonly used in cable theory is revised by taking into account electrical amplification due to intracellular capacitive effects in passive dendritic cables. A generalized cable equation for a cylindrical volume representation of a dendritic segment is derived from Maxwell's equations under assumptions: (i) the electric-field polarization is restricted longitudinally along the cable length; (ii) extracellular isopotentiality; (iii) quasielectrostatic conditions; and (iv) homogeneous medium with constant conductivity and permittivity. The generalized cable equation is identical to Barenblatt's equation arising in the theory of infiltration in fissured strata with a known analytical solution expressed in terms of a definite integral involving a modified Bessel function and the solution to a linear one-dimensional classical cable equation. Its solution is used to determine the impact of thermal noise on voltage attenuation with distance at any particular time. A regular perturbation expansion for the membrane potential about the linear one-dimensional classical cable equation solution is derived in terms of a Green's function in order to describe the dynamics of free charge within the Debye layer of endogenous structures in passive dendritic cables. The asymptotic value of the first perturbative term is explicitly evaluated for small values of time to predict how the slowly fluctuating (in submillisecond range) electric field attributed to intracellular capacitive effects alters the amplitude of the membrane potential. It was found that capacitive effects are almost negligible for cables with electrotonic lengths L>0.5 , contributes up to 10% of the signal for cables with electrotonic lengths in the range between 0.25noise due to

  18. Noise radiated by low-Reynolds number flows past a hemisphere at Ma = 0.3

    Yao, Hua-Dong; Davidson, Lars; Eriksson, Lars-Erik

    2017-07-01

    Flows past a hemisphere and their noise generation are investigated at the Reynolds numbers (Re) of 1000 and 5000. The Mach number is 0.3. The computational method of the flows is large eddy simulation. The noise is computed using the Ffowcs Williams and Hawkings Formulation 1C (F1C). An integral surface with an open end is defined for the F1C. The end surface is removed to reduce the numerical contamination that is introduced by vortices passing this surface. However, the contamination cannot be completely reduced since a discontinuity of the flow quantities still exists at the open surface boundary. This problem is solved using a surface correction method, in which a buffer zone is set up at the end of the integral surface. The transformation of flow structures due to Re is explored. Large coherent structures are observable at low Re, whereas they diminish at high Re. A large amount of small-scale turbulent vortices occur in the latter case. It is found that these characteristics of the flows have an important influence on the noise generation in regard to the noise spectra. In the flows studied in this work, the fluctuating pressure on the walls is a negligible noise contributor as compared with the wake.

  19. The regulations for enforcing the law concerning prevention from radiation hazards due to radioisotopes

    1978-01-01

    These provisions are established on the basis of and to enforce the ''Law for the prevention of radiation hazards due to radioisotopes'' and the Enforcement Order for the ''Law concerning the prevention of radiation hazards due to radioisotopes''. The Regulation includes the definitions of terms, applications for the permission of the use of radioisotopes, standards on usage, obligation of measurement, persons in charge of radiation, etc. Terms are explained, such as persons engaging in radiation works, persons who enter at any time the control areas, radiation facilities, maximum permissible exposure dose, cumulative dose, maximum permissible cumulative dose, maximum permissible concentration in the air, maximum permissible concentration in water and maximum permissible surface density. The applications for permission in written forms are required for the use, sale and abandonment of radioisotopes. Radioisotopes or the apparatuses for generating radiation shall be used in the using facilities. The measurement of radiation dose rate, particle flux density and contamination due to radioisotopes shall be made with radiation-measuring instruments. At least one person shall be chosen as the chief radiation-handling person in each factory, establishment, selling office or abandoning establishment by a user, a trademan or a person engaged in abandonment of radioisotopes. The forms for the application for permission, etc. are attached. (Okada, K.)

  20. Calculation of stochastic broadening due to noise and field errors in the simple map in action-angle coordinates

    Hinton, Courtney; Punjabi, Alkesh; Ali, Halima

    2008-11-01

    The simple map is the simplest map that has topology of divertor tokamaks [1]. Recently, the action-angle coordinates for simple map are analytically calculated, and simple map is constructed in action-angle coordinates [2]. Action-angle coordinates for simple map can not be inverted to real space coordinates (R,Z). Because there is logarithmic singularity on the ideal separatrix, trajectories can not cross separatrix [2]. Simple map in action-angle coordinates is applied to calculate stochastic broadening due to magnetic noise and field errors. Mode numbers for noise + field errors from the DIII-D tokamak are used. Mode numbers are (m,n)=(3,1), (4,1), (6,2), (7,2), (8,2), (9,3), (10,3), (11,3), (12,3) [3]. The common amplitude δ is varied from 0.8X10-5 to 2.0X10-5. For this noise and field errors, the width of stochastic layer in simple map is calculated. This work is supported by US Department of Energy grants DE-FG02-07ER54937, DE-FG02-01ER54624 and DE-FG02-04ER54793 1. A. Punjabi, H. Ali, T. Evans, and A. Boozer, Phys. Let. A 364, 140--145 (2007). 2. O. Kerwin, A. Punjabi, and H. Ali, to appear in Physics of Plasmas. 3. A. Punjabi and H. Ali, P1.012, 35^th EPS Conference on Plasma Physics, June 9-13, 2008, Hersonissos, Crete, Greece.

  1. Study of physio-psychological effects on traffic wardens due to traffic noise pollution; exposure-effect relation.

    Tabraiz, Shamas; Ahmad, Saeed; Shehzadi, Iffat; Asif, Muhammad Bilal

    2015-01-01

    Noise pollution has increased to alarming extent in most of the urban areas in Pakistan. It is assumed even more perilous than air and water pollution due to its direct acute and chronic physio-psychological effects. The objective of this study is to analyze and evaluate the psychological and physiological effects caused by traffic noise on traffic wardens and to find relation type between exposure time and effect. Three wardens check posts near roads were selected for survey in Taxila and Islamabad cities of Pakistan. Survey conducted included noise measurements at aforementioned check posts for one month and Performa based interviews of traffic wardens. Analysis of results showed that noise levels varied between 85-106 dB hence violating OSHA regulations. Major psychological effects found in wardens were aggravated depression 58%, stress 65%, public conflict 71%, irritation and annoyance 54%, behavioral affects 59% and speech interference 56%. Physiological effects found were hypertension 87%, muscle tension 64%, exhaustion 48%, low performance levels 55%, concentration loss 93%, hearing impairment 69%, headache 74% and cardiovascular issue 71%. Relation between exposure time and effects were evaluated by using simple regression test in excel. Percentage of psychological and physiological effects in wardens varied with the exposure time; aggravated depression (R(2) = 0.946, P = 0.133), stress suffering (R(2) = 0.014, P = 0.173), public conflict (R(2) = 0.946, P = 0.133), irritation and annoyance (R(2) = 0.371, P = 0.137), behavioral affects (R(2) = 0.596, P = 0.0616) and speech interference (R(2) = 0.355, P = 0.445), hypertension (R(2) = 0.96, P = 0.00095) and cardiovascular issue (R(2) = 0.775, P = 0.044).

  2. Viscoelastic property tuning for reducing noise radiated by switched-reluctance machines

    Millithaler, Pierre; Dupont, Jean-Baptiste; Ouisse, Morvan; Sadoulet-Reboul, Émeline; Bouhaddi, Noureddine

    2017-10-01

    Switched-reluctance motors (SRM) present major acoustic drawbacks that hinder their use for electric vehicles in spite of widely-acknowledged robustness and low manufacturing costs. Unlike other types of electric machines, a SRM stator is completely encapsulated/potted with a viscoelastic resin. By taking advantage of the high damping capacity that a viscoelastic material has in certain temperature and frequency ranges, this article proposes a tuning methodology for reducing the noise emitted by a SRM in operation. After introducing the aspects the tuning process will focus on, the article details a concrete application consisting in computing representative electromagnetic excitations and then the structural response of the stator including equivalent radiated power levels. An optimised viscoelastic material is determined, with which the peak radiated levels are reduced up to 10 dB in comparison to the initial state. This methodology is implementable for concrete industrial applications as it only relies on common commercial finite-element solvers.

  3. Response of Electrical Activity in an Improved Neuron Model under Electromagnetic Radiation and Noise.

    Zhan, Feibiao; Liu, Shenquan

    2017-01-01

    Electrical activities are ubiquitous neuronal bioelectric phenomena, which have many different modes to encode the expression of biological information, and constitute the whole process of signal propagation between neurons. Therefore, we focus on the electrical activities of neurons, which is also causing widespread concern among neuroscientists. In this paper, we mainly investigate the electrical activities of the Morris-Lecar (M-L) model with electromagnetic radiation or Gaussian white noise, which can restore the authenticity of neurons in realistic neural network. First, we explore dynamical response of the whole system with electromagnetic induction (EMI) and Gaussian white noise. We find that there are slight differences in the discharge behaviors via comparing the response of original system with that of improved system, and electromagnetic induction can transform bursting or spiking state to quiescent state and vice versa. Furthermore, we research bursting transition mode and the corresponding periodic solution mechanism for the isolated neuron model with electromagnetic induction by using one-parameter and bi-parameters bifurcation analysis. Finally, we analyze the effects of Gaussian white noise on the original system and coupled system, which is conducive to understand the actual discharge properties of realistic neurons.

  4. Response of Electrical Activity in an Improved Neuron Model under Electromagnetic Radiation and Noise

    Feibiao Zhan

    2017-11-01

    Full Text Available Electrical activities are ubiquitous neuronal bioelectric phenomena, which have many different modes to encode the expression of biological information, and constitute the whole process of signal propagation between neurons. Therefore, we focus on the electrical activities of neurons, which is also causing widespread concern among neuroscientists. In this paper, we mainly investigate the electrical activities of the Morris-Lecar (M-L model with electromagnetic radiation or Gaussian white noise, which can restore the authenticity of neurons in realistic neural network. First, we explore dynamical response of the whole system with electromagnetic induction (EMI and Gaussian white noise. We find that there are slight differences in the discharge behaviors via comparing the response of original system with that of improved system, and electromagnetic induction can transform bursting or spiking state to quiescent state and vice versa. Furthermore, we research bursting transition mode and the corresponding periodic solution mechanism for the isolated neuron model with electromagnetic induction by using one-parameter and bi-parameters bifurcation analysis. Finally, we analyze the effects of Gaussian white noise on the original system and coupled system, which is conducive to understand the actual discharge properties of realistic neurons.

  5. Optimizing CT technique to reduce radiation dose: effect of changes in kVp, iterative reconstruction, and noise index on dose and noise in a human cadaver.

    Chang, Kevin J; Collins, Scott; Li, Baojun; Mayo-Smith, William W

    2017-06-01

    For assessment of the effect of varying the peak kilovoltage (kVp), the adaptive statistical iterative reconstruction technique (ASiR), and automatic dose modulation on radiation dose and image noise in a human cadaver, a cadaver torso underwent CT scanning at 80, 100, 120 and 140 kVp, each at ASiR settings of 0, 30 and 50 %, and noise indices (NIs) of 5.5, 11 and 22. The volume CT dose index (CTDI vol ), image noise, and attenuation values of liver and fat were analyzed for 20 data sets. Size-specific dose estimates (SSDEs) and liver-to-fat contrast-to-noise ratios (CNRs) were calculated. Values for different combinations of kVp, ASiR, and NI were compared. The CTDI vol varied by a power of 2 with kVp values between 80 and 140 without ASiR. Increasing ASiR levels allowed a larger decrease in CTDI vol and SSDE at higher kVp than at lower kVp while image noise was held constant. In addition, CTDI vol and SSDE decreased with increasing NI at each kVp, but the decrease was greater at higher kVp than at lower kVp. Image noise increased with decreasing kVp despite a fixed NI; however, this noise could be offset with the use of ASiR. The CT number of the liver remained unchanged whereas that of fat decreased as the kVp decreased. Image noise and dose vary in a complicated manner when the kVp, ASiR, and NI are varied in a human cadaver. Optimization of CT protocols will require balancing of the effects of each of these parameters to maximize image quality while minimizing dose.

  6. Radiation Dose for Self-Disposal due to the Quantity of Radioactive Waste

    Koo, Daeseo; Sung, Hyun-Hee; Kim, Seung-Soo; Kim, Gye-Nam; Choi, Jong-Won [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    In this study, we evaluated resident radiation dose due to cover depth on contaminated zone such as uranium contaminated soil and concrete wastes under radiation dose limit using RESRAD Version 7.0. The uranium concentration of contaminated zone due to the cover depth are also analyzed. Possibility for self-disposal of uranium contaminated soil and concrete wastes is evaluated from these calculating data. There are several radioactive material disposal methods such as regulation exemption, decontamination and long term storage. To acquire radiation dose under self-disposal from them, the study on decontamination of some uranium contaminated soil and concrete wastes was performed using electrokinectic-electrodialytic. We evaluated radiation dose due to cover depth on contaminated zone such as uranium contaminated soil and concrete wastes under radiation dose limit using RESRAD Version 7.0. As cover depth increases, the tolerable uranium concentration increases up to cover depth (1.5 m) and then it showed saturated uranium concentration above cover depth (1.5 m). Therefore, to carry out self-disposal on the quantity (1000 drums≒300,000 kg) of radioactive waste is easier than to carry out on the quantity (2000 drums≒600,000 kg) of radioactive waste owing to the large tolerable uranium concentration for self-disposal of radioactive waste. As cover depth increases, the individual radiation dose rate decreased up to cover depth (1.5 m) and then it showed saturated individual radiation dose rate above cover depth (1.5 m)

  7. Radiation Dose for Self-Disposal due to the Quantity of Radioactive Waste

    Koo, Daeseo; Sung, Hyun-Hee; Kim, Seung-Soo; Kim, Gye-Nam; Choi, Jong-Won

    2016-01-01

    In this study, we evaluated resident radiation dose due to cover depth on contaminated zone such as uranium contaminated soil and concrete wastes under radiation dose limit using RESRAD Version 7.0. The uranium concentration of contaminated zone due to the cover depth are also analyzed. Possibility for self-disposal of uranium contaminated soil and concrete wastes is evaluated from these calculating data. There are several radioactive material disposal methods such as regulation exemption, decontamination and long term storage. To acquire radiation dose under self-disposal from them, the study on decontamination of some uranium contaminated soil and concrete wastes was performed using electrokinectic-electrodialytic. We evaluated radiation dose due to cover depth on contaminated zone such as uranium contaminated soil and concrete wastes under radiation dose limit using RESRAD Version 7.0. As cover depth increases, the tolerable uranium concentration increases up to cover depth (1.5 m) and then it showed saturated uranium concentration above cover depth (1.5 m). Therefore, to carry out self-disposal on the quantity (1000 drums≒300,000 kg) of radioactive waste is easier than to carry out on the quantity (2000 drums≒600,000 kg) of radioactive waste owing to the large tolerable uranium concentration for self-disposal of radioactive waste. As cover depth increases, the individual radiation dose rate decreased up to cover depth (1.5 m) and then it showed saturated individual radiation dose rate above cover depth (1.5 m)

  8. Assessment of occupational exposure due to external sources of radiation. Safety guide

    2000-01-01

    Occupational exposure to ionizing radiation can occur in a range of industries, medical institutions, educational and research establishments and nuclear fuel cycle facilities. Adequate radiation protection of workers is essential for the safe and acceptable use of radiation, radioactive materials and nuclear energy. The three Safety Guides on occupational radiation protection are jointly sponsored by the IAEA and the International Labour Office. The Agency gratefully acknowledges the contribution of the European Commission to the development of the present Safety Guide. The present Safety Guide addresses the assessment of exposure due to external sources of radiation in the workplace. Such exposure can result from a number of sources within a workplace, and the monitoring of workers and the workplace in such situations is an integral part of any occupational radiation protection programme. The assessment of exposure due to external radiation sources depends critically upon knowledge of the radiation type and energy and the conditions of exposure. The present Safety Guide reflects the major changes over the past decade in international practice in external dose assessment

  9. Assessment of occupational exposure due to external sources of radiation. Safety guide

    2004-01-01

    Occupational exposure to ionizing radiation can occur in a range of industries, medical institutions, educational and research establishments and nuclear fuel cycle facilities. Adequate radiation protection of workers is essential for the safe and acceptable use of radiation, radioactive materials and nuclear energy. The three Safety Guides on occupational radiation protection are jointly sponsored by the IAEA and the International Labour Office. The Agency gratefully acknowledges the contribution of the European Commission to the development of the present Safety Guide. The present Safety Guide addresses the assessment of exposure due to external sources of radiation in the workplace. Such exposure can result from a number of sources within a workplace, and the monitoring of workers and the workplace in such situations is an integral part of any occupational radiation protection programme. The assessment of exposure due to external radiation sources depends critically upon knowledge of the radiation type and energy and the conditions of exposure. The present Safety Guide reflects the major changes over the past decade in international practice in external dose assessment

  10. Assessment of occupational exposure due to external sources of radiation. Safety guide

    1999-01-01

    Occupational exposure to ionizing radiation can occur in a range of industries, medical institutions, educational and research establishments and nuclear fuel cycle facilities. Adequate radiation protection of workers is essential for the safe and acceptable use of radiation, radioactive materials and nuclear energy. The three Safety Guides on occupational radiation protection are jointly sponsored by the IAEA and the International Labour Office. The Agency gratefully acknowledges the contribution of the European Commission to the development of the present Safety Guide. The present Safety Guide addresses the assessment of exposure due to external sources of radiation in the workplace. Such exposure can result from a number of sources within a workplace, and the monitoring of workers and the workplace in such situations is an integral part of any occupational radiation protection programme. The assessment of exposure due to external radiation sources depends critically upon knowledge of the radiation type and energy and the conditions of exposure. The present Safety Guide reflects the major changes over the past decade in international practice in external dose assessment

  11. Investigation of noise radiation from a swirl stabilized diffusion flame with an array of microphones

    Singh, A.V.; Yu, M.; Gupta, A.K.; Bryden, K.M.

    2013-01-01

    Highlights: • Acoustic spectral characteristics independent of equivalence ratio and flow velocity. • Combustion noise dependent on global equivalence ratio and flow velocity. • Increased global equivalence ratio decreased the frequency of peak. • Decay and growth coefficients largely independent of different flow conditions. • Acoustic radiation coherent up to 1.5 kHz for spatially separated microphones. - Abstract: Next generation of combustors are expected to provide significant improvement on efficiency and reduced pollutants emission. In such combustors, the challenges of local flow, pressure, chemical composition and thermal signatures as well as their interactions will require detailed investigation for seeking optimum performance. Sensor networks with a large number of sensors will be employed in future smart combustors, which will allow one to obtain fast and comprehensive information on the various ongoing processes within the system. In this paper sensor networks with specific focus on an array of homogeneous microphones are used examine the spectral characteristics of combustion noise from a non-premixed combustor. A non-premixed double concentric swirl-flame burner was used. Noise spectra were determined experimentally for the non-premixed swirl flame at various fuel–air ratios using an array of homogeneous condenser microphones. Multiple microphones positioned at discrete locations around the turbulent diffusion flame, provided an understanding of the total sound power and their spectral characteristics. The growth and decay coefficients of total sound power were investigated at different test conditions. The signal coherence between different microphone pairs was also carried out to determine the acoustic behavior of a swirl stabilized turbulent diffusion flame. The localization of acoustic sources from the multiple microphones was examined using the noise spectra. The results revealed that integration of multiple sensors in combustors

  12. Noise suppression in duct

    Ahmed, A.; Barfeh, M.A.G.

    2001-01-01

    In air-conditioning system the noise generated by supply fan is carried by conditioned air through the ductwork. The noise created in ductwork run may be transmission, regenerative and ductborne. Transmission noise is fan noise, regenerative noise is due to turbulence in flow and ductborne noise is the noise radiating from duct to surroundings. Some noise is attenuated in ducts also but if noise level is high then it needs to be attenuated. A simple mitre bend can attenuate-noise. This principle is extended to V and M-shape ducts with inside lining of fibreglass, which gave maximum attenuation of 77 dB and 62 dB respectively corresponding to 8 kHz frequency as compared to mitre, bend giving maximum 18 dB attenuation. Sound level meter measured sound levels with octave band filter and tests were conducted in anechoic room. A V-shape attenuator can be used at fan outlet and high frequency noise can be minimized greatly. (author)

  13. Isotropization of the cosmic background radiation due to galactic gravitational screening

    Tomita, Kenji.

    1988-04-01

    The primordial objects with the masses of galaxies or their clusters formed at early stages such as z > 10 can play a powerful role of gravitational lenses and their random multiple scattering brings an effective screening for the cosmic background radiation. In a cold-dark-matter dominant model with the white-noise spectrum of initial density perturbations, it is shown that, if the primordial objects with the masses 10 12 h -1 (solar mass) are in the nonlinear stage at the epochs 1 + z = 10 ∼ 20, the objects with 6 x 10 14 h -1 (solar mass) are in the nonlinear stage at 1 + z = 6.3 ∼ 14, and accordingly the small-scale anisotropy of the radiation may be smoothed-out within 13 ∼ 28 minutes by this gravitational screening, where the Hubble constant H o = 100 h km s -1 Mpc -1 . (author)

  14. A case of ileo-cutaneou fistula due to radiation enteritis

    Oyama, Tsukasa; Oguchi, Yoshiro; Nakaba, Hiroyuki [Kure National Hospital, Hiroshima (Japan); and others

    1992-07-01

    Radiation enteritis can cause late complications including stenosis, perforation, fistulization, and bleeding, which sometimes necessitate surgical treatment, but a complication of ileocutaneous fistula is rarely reported. In this paper, an excellent result of an operation for ileocutaneous fistula due to radiation enteritis is described. A 68-year-old woman had undergone extended total histerectomy and radiation therapy on uterine cervical cancer. After the operation and the radiation therapy, frequent abdominal pain bothered her and then the intestinal fistula ensued resulted in the fistulization. The fistula was located between two stenotic lesions of the intestine caused by radiation enteritis. Resection of ileum including the two stenotic lesion and the fistula and end-to-end anastomosis relieved the symptoms and the treatment course has been satisfactory. The two stenotic lesions were resected because it was suggested that the two stenotic lesions directly led the fistulization. She is now followed asymptomatically. (author).

  15. The influence of acoustical and non-acoustical factors on short-term annoyance due to aircraft noise in the field - The COSMA study.

    Bartels, Susanne; Márki, Ferenc; Müller, Uwe

    2015-12-15

    Air traffic has increased for the past decades and is forecasted to continue to grow. Noise due to current airport operations can impair the physical and psychological well-being of airport residents. The field study investigated aircraft noise-induced short-term (i.e., within hourly intervals) annoyance in local residents near a busy airport. We aimed at examining the contribution of acoustical and non-acoustical factors to the annoyance rating. Across four days from getting up till going to bed, 55 residents near Cologne/Bonn Airport (M=46years, SD=14years, 34 female) rated their annoyance due to aircraft noise at hourly intervals. For each participant and each hour, 26 noise metrics from outdoor measurements and further 6 individualized metrics that took into account the sound attenuation due to each person's whereabouts in and around their homes were obtained. Non-acoustical variables were differentiated into situational factors (time of day, performed activity during past hour, day of the week) and personal factors (e.g., sensitivity to noise, attitudes, domestic noise insulation). Generalized Estimation Equations were applied for the development of a prediction model for annoyance. Acoustical factors explained only a small proportion (13.7%) of the variance in the annoyance ratings. The number of fly-overs predicted annoyance better than did equivalent and maximum sound pressure levels. The proportion of explained variance in annoyance rose considerably (to 27.6%) when individualized noise metrics as well as situational and personal variables were included in the prediction model. Consideration of noise metrics related to the number of fly-overs and individual adjustment of noise metrics can improve the prediction of short-term annoyance compared to models using equivalent outdoor levels only. Non-acoustical factors have remarkable impact not only on long-term annoyance as shown before but also on short-term annoyance judged in the home environment. Copyright

  16. New image-processing and noise-reduction software reduces radiation dose during complex endovascular procedures.

    Kirkwood, Melissa L; Guild, Jeffrey B; Arbique, Gary M; Tsai, Shirling; Modrall, J Gregory; Anderson, Jon A; Rectenwald, John; Timaran, Carlos

    2016-11-01

    A new proprietary image-processing system known as AlluraClarity, developed by Philips Healthcare (Best, The Netherlands) for radiation-based interventional procedures, claims to lower radiation dose while preserving image quality using noise-reduction algorithms. This study determined whether the surgeon and patient radiation dose during complex endovascular procedures (CEPs) is decreased after the implementation of this new operating system. Radiation dose to operators, procedure type, reference air kerma, kerma area product, and patient body mass index were recorded during CEPs on two Philips Allura FD 20 fluoroscopy systems with and without Clarity. Operator dose during CEPs was measured using optically stimulable, luminescent nanoDot (Landauer Inc, Glenwood, Ill) detectors placed outside the lead apron at the left upper chest position. nanoDots were read using a microStar ii (Landauer Inc) medical dosimetry system. For the CEPs in the Clarity group, the radiation dose to surgeons was also measured by the DoseAware (Philips Healthcare) personal dosimetry system. Side-by-side measurements of DoseAware and nanoDots allowed for cross-calibration between systems. Operator effective dose was determined using a modified Niklason algorithm. To control for patient size and case complexity, the average fluoroscopy dose rate and the dose per radiographic frame were adjusted for body mass index differences and then compared between the groups with and without Clarity by procedure. Additional factors, for example, physician practice patterns, that may have affected operator dose were inferred by comparing the ratio of the operator dose to procedural kerma area product with and without Clarity. A one-sided Wilcoxon rank sum test was used to compare groups for radiation doses, reference air kermas, and operating practices for each procedure type. The analysis included 234 CEPs; 95 performed without Clarity and 139 with Clarity. Practice patterns of operators during

  17. Perinatal radiation exposure due to nuclear medical use of radioactive compounds

    Gloebel, B.

    1982-01-01

    When the pregnancy is yet undetected, radiation doses were only relevant when given within therapeutic application. Only Hg 203-chloromerodrine and J 131-iodide are relevant for newborns as they cause radiation doses of 40-70 rad. in the organ concerned. As a result of nuclear medicine and the application of radio nuclides not only patients but also ''occupationally exposed'' persons and parts of the population are exposed to radiation. Pregnant women are not admitted in control areas but can only be forbidden to enter when the pregnancy has been established. This is the case after six weeks. The occupational perinatal exposure is therefore about 11% of the annual dose. Evaluation of the figures for exposure to radiation can be done by either comparing them with natural exposure or by estimating the risks. The somatic radiation risk per rad is of the 5th order, the genetic risk of the 4th to 6th order as compared with a spontaneous genetic risk of the 2nd order. According to surveys of STIEVE (1976) the risk involved in various diagnostic and therapeutic measures of complications not due to radiation exposure is of 2nd to fifth order. On an average, the risks of diagnostic measures in nuclear medicine are small in comparison to the radiation risk. A comparison with the range of natural radiation exposure also indicated that only exposures which exceed natural exposure of 0.4 rad have to be considered. (orig.) [de

  18. Investment strategy due to the minimization of portfolio noise level by observations of coarse-grained entropy

    Urbanowicz, Krzysztof; Hołyst, Janusz A.

    2004-12-01

    Using a recently developed method of noise level estimation that makes use of properties of the coarse-grained entropy, we have analyzed the noise level for the Dow Jones index and a few stocks from the New York Stock Exchange. We have found that the noise level ranges from 40% to 80% of the signal variance. The condition of a minimal noise level has been applied to construct optimal portfolios from selected shares. We show that the implementation of a corresponding threshold investment strategy leads to positive returns for historical data.

  19. Effect of external pressure environment on the internal noise level due to a source inside a cylindrical tank

    Clevenson, S. A.; Roussos, L. A.

    1984-01-01

    A small cylindrical tank was used to study the effect on the noise environment within a tank of conditions of atmospheric (sea level) pressure or vacuum environments on the exterior. Experimentally determined absorption coefficients were used to calculate transmission loss, transmissibility coefficients and the sound pressure (noise) level differences in the interior. The noise level differences were also measured directly for the two exterior environments and compared to various analytical approximations with limited agreement. Trend study curves indicated that if the tank transmission loss is above 25 dB, the difference in interior noise level between the vacuum and ambient pressure conditions are less than 2 dB.

  20. Investment strategy due to the minimization of portfolio noise level by observations of coarse-grained entropy

    Krzysztof Urbanowicz; Janusz A. Holyst

    2004-01-01

    Using a recently developed method of noise level estimation that makes use of properties of the coarse grained-entropy we have analyzed the noise level for the Dow Jones index and a few stocks from the New York Stock Exchange. We have found that the noise level ranges from 40 to 80 percent of the signal variance. The condition of a minimal noise level has been applied to construct optimal portfolios from selected shares. We show that implementation of a corresponding threshold investment stra...

  1. Measurements and simulations of the radiation exposure to aircraft crew workplaces due to cosmic radiation in the atmosphere

    Beck, P.; Latocha, M.; Dorman, L.; Pelliccioni, M.; Rollet, S.

    2007-01-01

    As required by the European Directive 96/29/Euratom, radiation exposure due to natural ionizing radiation has to be taken into account at workplaces if the effective dose could become more than 1 mSv per year. An example of workers concerned by this directive is aircraft crew due to cosmic radiation exposure in the atmosphere. Extensive measurement campaigns on board aircraft have been carried out to assess ambient dose equivalent. A consortium of European dosimetry institutes within EURADOS WG5 summarized experimental data and results of calculations, together with detailed descriptions of the methods for measurements and calculations. The radiation protection quantity of interest is the effective dose, E (ISO). The comparison of results by measurements and calculations is done in terms of the operational quantity ambient dose equivalent, H*(10). This paper gives an overview of the EURADOS Aircraft Crew In-Flight Database and it presents a new empirical model describing fitting functions for this data. Furthermore, it describes numerical simulations performed with the Monte Carlo code FLUKA-2005 using an updated version of the cosmic radiation primary spectra. The ratio between ambient dose equivalent and effective dose at commercial flight altitudes, calculated with FLUKA-2005, is discussed. Finally, it presents the aviation dosimetry model AVIDOS based on FLUKA-2005 simulations for routine dose assessment. The code has been developed by Austrian Research Centers (ARC) for the public usage (http://avidos.healthphysics.at. (authors)

  2. Analysis of noise radiation mechanisms in hot subsonic jet from a validated large eddy simulation solution

    Lorteau, Mathieu, E-mail: mathieu.lorteau@onera.fr; Cléro, Franck, E-mail: franck.clero@onera.fr; Vuillot, François, E-mail: francois.vuillot@onera.fr [Onera–The French Aerospace Lab, F-92322 Châtillon (France)

    2015-07-15

    In the framework of jet noise computation, a numerical simulation of a subsonic turbulent hot jet is performed using large-eddy simulation. A geometrical tripping is used in order to trigger the turbulence at the nozzle exit. In a first part, the validity of the simulation is assessed by comparison with experimental measurements. The mean and rms velocity fields show good agreement, so do the azimuthal composition of the near pressure field and the far field spectra. Discrepancies remain close to the nozzle exit which lead to a limited overestimation of the pressure levels in both near and far fields, especially near the 90{sup ∘} angular sector. Two point correlation analyses are then applied to the data obtained from the simulation. These enable to link the downstream acoustic radiation, which is the main direction of radiation, to pressure waves developing in the shear layer and propagating toward the potential core end. The intermittency of the downstream acoustic radiation is evidenced and related to the coherent structures developing in the shear layer.

  3. Characterization of Flap Edge Noise Radiation from a High-Fidelity Airframe Model

    Humphreys, William M., Jr.; Khorrami, Mehdi R.; Lockard, David P.; Neuhart, Dan H.; Bahr, Christopher J.

    2015-01-01

    The results of an experimental study of the noise generated by a baseline high-fidelity airframe model are presented. The test campaign was conducted in the open-jet test section of the NASA Langley 14- by 22-foot Subsonic Tunnel on an 18%-scale, semi-span Gulfstream airframe model incorporating a trailing edge flap and main landing gear. Unsteady surface pressure measurements were obtained from a series of sensors positioned along the two flap edges, and far field acoustic measurements were obtained using a 97-microphone phased array that viewed the pressure side of the airframe. The DAMAS array deconvolution method was employed to determine the locations and strengths of relevant noise sources in the vicinity of the flap edges and the landing gear. A Coherent Output Power (COP) spectral method was used to couple the unsteady surface pressures measured along the flap edges with the phased array output. The results indicate that outboard flap edge noise is dominated by the flap bulb seal cavity with very strong COP coherence over an approximate model-scale frequency range of 1 to 5 kHz observed between the array output and those unsteady pressure sensors nearest the aft end of the cavity. An examination of experimental COP spectra for the inboard flap proved inconclusive, most likely due to a combination of coherence loss caused by decorrelation of acoustic waves propagating through the thick wind tunnel shear layer and contamination of the spectra by tunnel background noise at lower frequencies. Directivity measurements obtained from integration of DAMAS pressure-squared values over defined geometric zones around the model show that the baseline flap and landing gear are only moderately directional as a function of polar emission angle.

  4. Research on Ship-Radiated Noise Denoising Using Secondary Variational Mode Decomposition and Correlation Coefficient.

    Li, Yuxing; Li, Yaan; Chen, Xiao; Yu, Jing

    2017-12-26

    As the sound signal of ships obtained by sensors contains other many significant characteristics of ships and called ship-radiated noise (SN), research into a denoising algorithm and its application has obtained great significance. Using the advantage of variational mode decomposition (VMD) combined with the correlation coefficient for denoising, a hybrid secondary denoising algorithm is proposed using secondary VMD combined with a correlation coefficient (CC). First, different kinds of simulation signals are decomposed into several bandwidth-limited intrinsic mode functions (IMFs) using VMD, where the decomposition number by VMD is equal to the number by empirical mode decomposition (EMD); then, the CCs between the IMFs and the simulation signal are calculated respectively. The noise IMFs are identified by the CC threshold and the rest of the IMFs are reconstructed in order to realize the first denoising process. Finally, secondary denoising of the simulation signal can be accomplished by repeating the above steps of decomposition, screening and reconstruction. The final denoising result is determined according to the CC threshold. The denoising effect is compared under the different signal-to-noise ratio and the time of decomposition by VMD. Experimental results show the validity of the proposed denoising algorithm using secondary VMD (2VMD) combined with CC compared to EMD denoising, ensemble EMD (EEMD) denoising, VMD denoising and cubic VMD (3VMD) denoising, as well as two denoising algorithms presented recently. The proposed denoising algorithm is applied to feature extraction and classification for SN signals, which can effectively improve the recognition rate of different kinds of ships.

  5. Research on Ship-Radiated Noise Denoising Using Secondary Variational Mode Decomposition and Correlation Coefficient

    Yuxing Li

    2017-12-01

    Full Text Available As the sound signal of ships obtained by sensors contains other many significant characteristics of ships and called ship-radiated noise (SN, research into a denoising algorithm and its application has obtained great significance. Using the advantage of variational mode decomposition (VMD combined with the correlation coefficient for denoising, a hybrid secondary denoising algorithm is proposed using secondary VMD combined with a correlation coefficient (CC. First, different kinds of simulation signals are decomposed into several bandwidth-limited intrinsic mode functions (IMFs using VMD, where the decomposition number by VMD is equal to the number by empirical mode decomposition (EMD; then, the CCs between the IMFs and the simulation signal are calculated respectively. The noise IMFs are identified by the CC threshold and the rest of the IMFs are reconstructed in order to realize the first denoising process. Finally, secondary denoising of the simulation signal can be accomplished by repeating the above steps of decomposition, screening and reconstruction. The final denoising result is determined according to the CC threshold. The denoising effect is compared under the different signal-to-noise ratio and the time of decomposition by VMD. Experimental results show the validity of the proposed denoising algorithm using secondary VMD (2VMD combined with CC compared to EMD denoising, ensemble EMD (EEMD denoising, VMD denoising and cubic VMD (3VMD denoising, as well as two denoising algorithms presented recently. The proposed denoising algorithm is applied to feature extraction and classification for SN signals, which can effectively improve the recognition rate of different kinds of ships.

  6. Three cases of lumbo-sacral neuropathy due to radiation for uterine cancer

    Maruyama, Yoshikazu; Hokezu, Yoichi; Kanehisa, Yoshihide; Nagamatsu, Keiji; Onishi, Akio

    1985-01-01

    Case 1: The 61-year-old woman developed uterine cancer at age 50. Radiation therapy was initiated to the pelvic lumen from both anterior and posterior sides with a total dose of 21,000 rads. Radiation ulcerative enterocolitis and dermatitis revealed at the end of the therapy. At age 52 (2 years after radiation), she noticed muscle weakness and dysesthesia of the lower legs. These symptoms progressed and amyotrophy of the legs appeared. At age 54 (4 years after radiation), she became unable to walk. Case 2: The 51-year-old woman developed uterine cancer at age 40. Postoperative radiation was initiated by the same dose and the same way as in Case 1 and she suffered from radiation dermatitis. At age 49 (9 years after radiation), she noticed dysesthesia of the right toe, which gradually spread to another side. Ten years after radiation, she began to note weakness in dorsiflexion of feet. Case 3: The 69-year-old woman developed uterine cancer at age 67. Radiation (Linac 4,000 rads, Ralstron 2,000 rads) was performed for 3 months into the pelvic lumen. Two years later, she noted dysesthesia and weakness of her legs. These symptoms progressed gradually. In these 3 cases, EMG showed neurogenic changes, suggesting peripheral nerve lesions. Nerve conduction velocities were decreased. Nerve and muscle biopsies revealed neurogenic changes. No abnormal findings were detected by spinal X-rays and myelography. The neurological findings of these patients were compatible with the lumbo-sacrol plexus injuries apparently due to late radiation effect. (J.P.N.).

  7. Increasing of Urban Radiation due to Climate Change and Reduction Strategy using Vegetation

    Park, C.; Lee, D.; Heo, H. K.; Ahn, S.

    2017-12-01

    Urban Heat Island (UHI) which means urban air temperature is higher than suburban area is one of the most important environmental issues in Urban. High density of buildings and high ratio of impervious surfaces increases the radiation fluxes in urban canopy. Furthermore, climate change is expected to make UHI even more seriously in the future. Increased irradiation and air temperature cause high amount of short wave and long wave radiation, respectively. This increases net radiation negatively affects heat condition of pedestrian. UHI threatens citizen's health by increasing violence and heat related diseases. For this reason, understanding how much urban radiation will increase in the future, and exploring radiation reduction strategies is important for reducing UHI. In this research, we aim to reveal how the radiation flux in the urban canyon will change as the climate change and determine how much of urban vegetation will be needed to cover this degradation. The study area is a commercial district in Seoul where highly populated area. Due to the high density of buildings and lack of urban vegetation, this area has a poor thermal condition in summer. In this research, we simulate the radiation flux on the ground using multi-layer urban canopy model. Unlike conventionally used urban canopy model to simulate radiation transfer using vertically single layer, the multi-layer model we used here, enables to consider the vertical heterogeneous of buildings and urban vegetation. As a result, net radiation of urban ground will be increase 2.1 W/m² in the 2050s and 2.7 W/m² in the 2100s. And to prevent the increase of radiation, it is revealed that the urban vegetation should by increased by 10%. This research will be valuable in establishing greening planning as a strategy to reduce UHI effect.

  8. Three cases of lumbo-sacral neuropathy due to radiation for uterine cancer

    Maruyama, Yoshikazu; Hokezu, Yoichi; Kanehisa, Yoshihide; Nagamatsu, Keiji; Onishi, Akio.

    1985-01-01

    Case 1: The 61-year-old woman developed uterine cancer at age 50. Radiation therapy was initiated to the pelvic lumen from both anterior and posterior sides with a total dose of 21,000 rads. Radiation ulcerative neterocolitis and dermatitis revealed at the end of the therapy. At age 52 (2 years after radiation), she noticed muscle weakness and dysesthesia of the lower legs. These symptoms progressed and amyotrophy of the legs appeared. At age 54 (4 years after radiation), she became unable to walk. Case 2: The 51-year-old woman developed uterine cancer at age 40. Postoperative radiation was initiated by the same dose and the same way as in Case 1 and she suffered from radiation dermatitis. At age 49 (9 years after radiation), she noticed dysesthesia of the right toe, which gradually spread to another side. Ten years after radiation, she began to note weakness in dorsiflexion of feet. Case 3: The 69-year-old woman developed uterine cancer at age 67. Radiation (Linac 4,000 rads, Ralstron 2,000 rads) was performed for 3 months into the pelvic lumen. Two years later, she noted dysesthesia and weakness of her legs. These symptoms progressed gradually. In these 3 cases, EMG showed neurogenic changes, suggesting peripheral nerve lesions. Nerve conduction velocities were decreased. Nerve and muscle biopsies revealed neurogenic changes. No abnormal findings were detected by spinal X-rays and myelography. The neurological findings of these patients were compatible with the lumbo-sacrol plexus injuries apparently due to late radiation effect. (J.P.N.)

  9. Calculation of heat generation due to nuclear radiation in nuclear reactors

    Torres, L.M.R.; Gomes, I.C.; Maiorino, J.R.

    1986-01-01

    The study is performed for caculating nuclear heating due to the interaction of neutrons and gamma-rays with matter. Modifications were implemented in the ANISN code, that solves the one-dimensional transport equation using the discrete ordinate method, to include nuclear heating calculations. Tests of the implemented modifications were performed in problems of nuclear heating due to radiation energy deposition in a fusion reactor. (Author) [pt

  10. Computation of Aerodynamic Noise Radiated from Ducted Tail Rotor Using Boundary Element Method

    Yunpeng Ma

    2017-01-01

    Full Text Available A detailed aerodynamic performance of a ducted tail rotor in hover has been numerically studied using CFD technique. The general governing equations of turbulent flow around ducted tail rotor are given and directly solved by using finite volume discretization and Runge-Kutta time integration. The calculations of the lift characteristics of the ducted tail rotor can be obtained. In order to predict the aerodynamic noise, a hybrid method combining computational aeroacoustic with boundary element method (BEM has been proposed. The computational steps include the following: firstly, the unsteady flow around rotor is calculated using the CFD method to get the noise source information; secondly, the radiate sound pressure is calculated using the acoustic analogy Curle equation in the frequency domain; lastly, the scattering effect of the duct wall on the propagation of the sound wave is presented using an acoustic thin-body BEM. The aerodynamic results and the calculated sound pressure levels are compared with the known technique for validation. The sound pressure directivity and scattering effect are shown to demonstrate the validity and applicability of the method.

  11. Forecasting noise and radiation hardness of CMOS front-end electronics beyond the 100 nm frontier

    Re, V.; Gaioni, L.; Manghisoni, M.; Ratti, L.; Traversi, G.

    2010-01-01

    The progress of industrial microelectronic technologies has already overtaken the 130 nm CMOS generation that is currently the focus of IC designers for new front-end chips in LHC upgrades and other detector applications. In a broader time span, sub-100 nm CMOS processes may become appealing for the design of very compact front-end systems with advanced integrated functionalities. This is especially true in the case of pixel detectors, both for monolithic devices (MAPS) and for hybrid implementations where a high resistivity sensor is connected to a CMOS readout chip. Technologies beyond the 100 nm frontier have peculiar features, such as the evolution of the device gate material to reduce tunneling currents through the thin dielectric. These new physical device parameters may impact on functional properties such as noise and radiation hardness. On the basis of experimental data relevant to commercial devices, this work studies potential advantages and challenges associated to the design of low-noise and rad-hard analog circuits in these aggressively scaled technologies.

  12. Dose rate effect on material aging due to radiation. [Gamma radiation

    Okamoto, Shin-ichi (Radiation Center of Osaka Prefecture, Sakai (Japan)); Hayakawa, Chikara; Takeya, Chikashi

    1982-12-01

    Although many reports have been presented on the radiation aging of the organic materials for electric cables, those have been based on the experiments carried out at high dose rate near 1 x 10/sup 6/ rad/h, assuming that aging effect depends on only radiation dose. Therefore, to investigate the aging behaviour in low dose rate range is an important subject to predict their practical life time. In this report, the results of having investigated the aging behaviour of six types of materials are described, (polyethylene for general insulation purpose, chemically cross-linked polyethylene, fire-retardant chemically cross-linked polyethylene, fire-retardant ethylene-propylene rubber, fire-retardant chloro-sulfonated polyethylene for sheaths, and fire-retardant, low hydrochloric acid, special heat-resistant vinyl for insulation purpose or chloroclean). They were irradiated with /sup 60/Co ..gamma..-ray at the dose from 5 x 10/sup 3/ to 1 x 10/sup 6/ rad/h, and their deterioration was tested for the items of elongation, tensile strength, resistivity, dielectric tangent and gel fraction. The aging mechanism and dose rate effect were also considered. The dose rate effect appeared or did not appear depending on the types of materials and also their properties. The materials that showed the dose rate effect included the typical ones whose characteristics degraded with the decreasing dose rate, and the peculiar ones whose deterioration of characteristics did not appear constantly. Aging mechanism may vary in the case of high dose rate and low dose rate. Also, if the life time at respective dose rate in relatively higher dose rate region is clarified, the life time in low dose rate region may possibly be predicted.

  13. Radiation dose to the lungs due to inhalation of alpha emitters

    Haque, A.K.M.M.; Al-Affan, I.A.M.

    1987-01-01

    The radiation dose to the lungs due to inhalation of radon daughters has been computed with improved data on lung models, aerosol parameters, deposition and clearance mechanisms. The dose corresponds to mean radon concentration of 23 Bq/m 3 indoors (recent NRPB Survey) for different living conditions. The dose rate to basal cells in gen. 5 is 12 mGy/WLM. (author)

  14. Some observations of the variations in natural gamma radiation due to rainfall

    Minato, S.

    1980-01-01

    Results of observations of variations in natural gamma-radiation flux densities due to rainfall are presented and discussed in relation to rate of rainfall. Variations of fluences with amounts of rainfall are also described. It is concluded that the frequency distribution of the ratio of the fluence to the amount of rainfall has a trend to be lognormal

  15. Ionizing Radiation Effects on the Noise of 65 nm CMOS Transistors for Pixel Sensor Readout at Extreme Total Dose Levels

    Re, V.; Manghisoni, M.; Riceputi, E.; Traversi, G.; Ratti, L.

    2018-01-01

    This paper is focused on the study of the noise performance of 65 nm CMOS transistors at extremely high total ionizing dose (TID) levels of the order of several hundreds of Mrad(SiO2). Noise measurements are reported and discussed, analyzing radiation effects on 1/ f noise and channel thermal noise. In nMOSFETs, up to 10 Mrad(SiO2), the experimental behavior is consistent with a damage mechanism mainly associ- ated with lateral isolation oxides, and can be modeled by parasitic transistors turning on after irradiation and contributing to the total noise of the device. At very high dose, these parasitic transistors tend to be turned off by negative charge accumulating in interface states and compensating radiation-induced positive charge building up inside thick isolation oxides. Effects associated with ionization and hydrogen transport in spacer oxides may become dominant at 600 Mrad(SiO2) and may explain the observed noise behavior at extremely high TID. The results of this analysis provide an understanding o...

  16. Direct radiative effect due to brownness in organic carbon aerosols generated from biomass combustion

    Rathod, T.D.; Sahu, S.K.; Tiwari, M.; Pandit, G.G.

    2016-01-01

    We report the enhancement in the direct radiative effect due the presence of Brown carbon (BrC) as a part of organic carbon aerosols. The optical properties of organic carbon aerosols generated from pyrolytic combustion of mango tree wood (Magnifera Indica) and dung cake at different temperatures were considered. Mie codes were used to calculate absorption and scattering coefficients coupled with experimentally derived imaginary complex refractive index. The direct radiative effect (DRE) for sampled organic carbon aerosols was estimated using a wavelength dependent radiative transfer equation. The BrC DRE was estimated taking virtually non absorbing organic aerosols as reference. The BrC DRE from wood and dung cake was compared at different combustion temperatures and conditions. The BrC contributed positively to the direct top of the atmosphere radiative effect. Dung cake generated BrC aerosols were found to be strongly light absorbing as compared to BrC from wood combustion. It was noted that radiative effects of BrC from wood depended on its generation temperature and conditions. For BrC aerosols from dung cake such strong dependence was not observed. The average BrC aerosol DRE values were 1.53±0.76 W g"−"1 and 17.84±6.45 W g"−"1 for wood and dung cake respectively. The DRE contribution of BrC aerosols came mainly (67–90%) from visible light absorption though they exhibited strong absorption in shorter wavelengths of the UV–visible spectrum. - Highlights: • Biomass fuels (wood and dung cake) were studied for brown carbon direct radiative effects. • Model calculations predicted positive contribution of Brown carbon aerosols to organic carbon direct radiative effect. • Average direct radiative values for brown carbon from dung cake were higher compare to wood. • The visible light absorption played major role in brown carbon contribution (67–90 %) to total direct radiative effect.

  17. Noise-based tube current reduction method with iterative reconstruction for reduction of radiation exposure in coronary CT angiography

    Shen, Junlin; Du, Xiangying; Guo, Daode; Cao, Lizhen; Gao, Yan; Bai, Mei; Li, Pengyu; Liu, Jiabin; Li, Kuncheng

    2013-01-01

    Purpose: To investigate the potential of noise-based tube current reduction method with iterative reconstruction to reduce radiation exposure while achieving consistent image quality in coronary CT angiography (CCTA). Materials and methods: 294 patients underwent CCTA on a 64-detector row CT equipped with iterative reconstruction. 102 patients with fixed tube current were assigned to Group 1, which was used to establish noise-based tube current modulation formulas, where tube current was modulated by the noise of test bolus image. 192 patients with noise-based tube current were randomly assigned to Group 2 and Group 3. Filtered back projection was applied for Group 2 and iterative reconstruction for Group 3. Qualitative image quality was assessed with a 5 point score. Image noise, signal intensity, volume CT dose index, and dose-length product were measured. Results: The noise-based tube current modulation formulas were established through regression analysis using image noise measurements in Group 1. Image noise was precisely maintained at the target value of 35.00 HU with small interquartile ranges for Group 2 (34.17–35.08 HU) and Group 3 (34.34–35.03 HU), while it was from 28.41 to 36.49 HU for Group 1. All images in the three groups were acceptable for diagnosis. A relative 14% and 41% reduction in effective dose for Group 2 and Group 3 were observed compared with Group 1. Conclusion: Adequate image quality could be maintained at a desired and consistent noise level with overall 14% dose reduction using noise-based tube current reduction method. The use of iterative reconstruction further achieved approximately 40% reduction in effective dose

  18. Low noise monolithic Si JFETs for operation in the 90-300K Range and in high radiation environments

    Radeka, V.; Citterio, M.; Rescia, S.; Manfredi, P.F.; Speziali, V.

    1994-12-01

    Development of low noise preamplifters for large ionization chambers with liquid argon (LAr) and liquid krypton (LKr) used in high energy physics experiments for measurement of energy of charged particles and photons requires die choice of a technology able to withstand the environment: a temperature of 90 K -120 K; an ionizing radiation dose of 1-2 Mrad; a neutron fluence of 0.5 -1.10 14 n/cm 2 . Silicon JFETs by virtue of their reliable noise behavior and their intrinsic radiation hardness appear to be very suitable devices for applications both at room and cryogenic temperatures. We describe the noise properties of JFET devices and a monolithic preamplifier suitable for amplification of charge and current signals

  19. Revise of the law concerning prevention from radiation hazards due to radioisotopes, etc

    Sakamoto, Yoshiaki; Sendo, Muneaki

    2004-01-01

    The Law Concerning Prevention from Radiation Hazards due to Radioisotopes, etc. was revised in 2004. The regulation about disposal of RI waste was fixed at this revise of the law. Regulation of an application about the disposal of the RI waste was added to former radioactive waste control business. And regulation of confirmation of waste disposal by a regulation body was added. By this law revision, a necessary system for the RI waste disposal is ready. Furthermore, the Basic Safety Standard (BSS) and the following rationalization of related to regulation were introduced into the Law Concerning Prevention from Radiation Hazards due to Radioisotopes, etc. by this law revision. The regulation for a handling of radionuclides will be changed a lot due to the introduction of the BSS. (author)

  20. Corrosion by photochemical reaction due to synchrotron radiation in TRISTAN vacuum system

    Momose, Takashi; Ishimaru, Hajime

    1989-01-01

    In the electron-positron collision ring (TMR) in the National Laboratory for High Energy Physics, the operation at the beam energy of 30 GeV is carried out. The critical energy of synchrotron radiation corresponding to this energy is 243 keV which is the highest in the world. Consequently, the radiation damage of various substances due to this radiation has become the problem. From the viewpoint that the TMR is the vacuum system totally made of aluminum alloy for the first time in the world, the problem peculiar to aluminum alloy and the related problem of material damage and the countermeasures are discussed. Beam energy and attenuation length, the radiation dose in the TMR tunnel, the beam current-time product of TMR, the examples of radiation damage such as the atmosphere in TAR, the atmosphere in TMR, the aluminum bellows, aluminum chamber and lead radiation shield in TMR, the aluminum beam line in the atmosphere of TAR, the heat-insulating kapton film with vacuum deposited aluminum films, Teflon and polystyrene insulators, the stainless steel terminals and cables for position monitors, the O-rings for gate valves, polyvinyl chloride and so on are reported. (K.I.)

  1. Mechanism of Cuticle Hole Development in Human Hair Due to UV-Radiation Exposure

    Kazuhisa Maeda

    2018-03-01

    Full Text Available Hair is easily damaged by ultraviolet (UV radiation, bleaching agents or permanent wave treatments, and as damage progresses, hair loses its gloss, develops split ends and breaks. However, the causes of hair damage due to UV radiation have not yet been clarified. We discovered that in one mechanism facilitating damage to wet hair by UV radiation, the unsaturated fatty acids in wet hair produce hydroxy radicals upon exposure to UV radiation, and these radicals produce cuticle holes between the cuticle layers. In wet hair exposed to UV radiation, cuticle holes were produced only between the cuticle layers, whereas when human hair was immersed in a solution containing hydroxy radicals produced by Fenton’s reaction, a random production of cuticle holes was noted. It is thought that hydroxy radicals are produced only between the cuticle layers by exposure to UV radiation, and cuticle holes are formed only in this region because one of the polyunsaturated fatty acids, linoleic acid, with a bis-allyl hydrogen, is found between the cuticle layers.

  2. Suppression of the Rayleigh-Taylor instability due to self-radiation in a multiablation target

    Fujioka, Shinsuke; Sunahara, Atsushi; Nishihara, Katsunobu; Johzaki, Tomoyuki; Shiraga, Hiroyuki; Shigemori, Keisuke; Nakai, Mitsuo; Ikegawa, Tadashi; Murakami, Masakatsu; Nagai, Keiji; Norimatsu, Takayoshi; Azechi, Hiroshi; Yamanaka, Tatsuhiko; Ohnishi, Naofumi

    2004-01-01

    A scheme to suppress the Rayleigh-Taylor instability has been investigated for a direct-drive inertial fusion target. In a high-Z doped-plastic target, two ablation surfaces are formed separately--one driven by thermal radiation and the other driven by electron conduction. The growth of the Rayleigh-Taylor instability is significantly suppressed on the radiation-driven ablation surface inside the target due to the large ablation velocity and long density scale length. A significant reduction of the growth rate was observed in simulations and experiments using a brominated plastic target. A new direct-drive pellet was designed using this scheme

  3. Generation of interior cavity noise due to window vibration excited by turbulent flows past a generic side-view mirror

    Yao, Hua-Dong; Davidson, Lars

    2018-03-01

    We investigate the interior noise caused by turbulent flows past a generic side-view mirror. A rectangular glass window is placed downstream of the mirror. The window vibration is excited by the surface pressure fluctuations and emits the interior noise in a cuboid cavity. The turbulent flows are simulated using a compressible large eddy simulation method. The window vibration and interior noise are predicted with a finite element method. The wavenumber-frequency spectra of the surface pressure fluctuations are analyzed. The spectra are identified with some new features that cannot be explained by the Chase model for turbulent boundary layers. The spectra contain a minor hydrodynamic domain in addition to the hydrodynamic domain caused by the main convection of the turbulent boundary layer. The minor domain results from the local convection of the recirculating flow. These domains are formed in bent elliptic shapes. The spanwise expansion of the wake is found causing the bending. Based on the wavenumber-frequency relationships in the spectra, the surface pressure fluctuations are decomposed into hydrodynamic and acoustic components. The acoustic component is more efficient in the generation of the interior noise than the hydrodynamic component. However, the hydrodynamic component is still dominant at low frequencies below approximately 250 Hz since it has low transmission losses near the hydrodynamic critical frequency of the window. The structural modes of the window determine the low-frequency interior tonal noise. The combination of the mode shapes of the window and cavity greatly affects the magnitude distribution of the interior noise.

  4. Active Control of Fan Noise-Feasibility Study. Volume 2: Canceling Noise Source-Design of an Acoustic Plate Radiator Using Piezoceramic Actuators

    Pla, F. G.; Rajiyah, H.

    1995-01-01

    The feasibility of using acoustic plate radiators powered by piezoceramic thin sheets as canceling sources for active control of aircraft engine fan noise is demonstrated. Analytical and numerical models of actuated beams and plates are developed and validated. An optimization study is performed to identify the optimum combination of design parameters that maximizes the plate volume velocity for a given resonance frequency. Fifteen plates with various plate and actuator sizes, thicknesses, and bonding layers were fabricated and tested using results from the optimization study. A maximum equivalent piston displacement of 0.39 mm was achieved with the optimized plate samples tested with only one actuator powered, corresponding to a plate deflection at the center of over 1 millimeter. This is very close to the deflection required for a full size engine application and represents a 160-fold improvement over previous work. Experimental results further show that performance is limited by the critical stress of the piezoceramic actuator and bonding layer rather than by the maximum moment available from the actuator. Design enhancements are described in detail that will lead to a flight-worthy acoustic plate radiator by minimizing actuator tensile stresses and reducing nonlinear effects. Finally, several adaptive tuning methods designed to increase the bandwidth of acoustic plate radiators are analyzed including passive, active, and semi-active approaches. The back chamber pressurization and volume variation methods are investigated experimentally and shown to be simple and effective ways to obtain substantial control over the resonance frequency of a plate radiator. This study shows that piezoceramic-based plate radiators can be a viable acoustic source for active control of aircraft engine fan noise.

  5. Increase of solar radiation due to climate change and its impact on solar energy use

    Kuhnke, K.; Rahme, A.; Harling, J.; Arensmann, R.

    2008-01-01

    Full text: There is a significant change in solar radiation in Central Europe coinciding with the IPCC climate change model calculations. The increase of yearly solar radiation on the horizontal surface is about 0.38 percent/year. On the other hand, photovoltaic solar modules show an ageing effect of the same order of magnitude, i.e. a reduction of yearly energy yield between 0.3 and 0.5 percent/year. This reduction is normally taken into account in economic calculations such as payback time and internal rate of interest. As the two trends of increase in radiation and ageing of solar modules are in opposite direction to each other, they will - with their uncertainties - neutralize one another to zero. Thus, the energy production of photovoltaic systems can be calculated without any deductions due to ageing in the future. (authors)

  6. Radiation dose estimates due to air particulate emissions from selected phosphate industry operations

    Partridge, J.E.; Horton, T.R.; Sensintaffar, E.L.; Boysen, G.A.

    1978-06-01

    The EPA Office of Radiation Programs has conducted a series of studies to determine the radiological impact of the phosphate mining and milling industry. This report describes the efforts to estimate the radiation doses due to airborne emissions of particulates from selected phosphate milling operations in Florida. Two wet process phosphoric acid plants and one ore drying facility were selected for this study. The 1976 Annual Operations/Emissions Report, submitted by each facility to the Florida Department of Environmental Regulation, and a field survey trip by EPA personnel to each facility were used to develop data for dose calculations. The field survey trip included sampling for stack emissions and ambient air samples collected in the general vicinity of each plant. Population and individual radiation dose estimates are made based on these sources of data

  7. Simulating threshold voltage shift of MOS devices due to radiation in the low-dose range

    Wan Xin Heng; Gao Wen Yu; Huang Ru; Wang Yang Yuan

    2002-01-01

    An analytical MOSFET threshold voltage shift model due to radiation in the low-dose range has been developed for circuit simulations. Experimental data in the literature shows that the model predictions are in good agreement. It is simple in functional form and hence computationally efficient. It can be used as a basic circuit simulation tool for analysing MOSFET exposed to a nuclear environment up to about 1 Mrad(Si). In accordance with common believe, radiation induced absolute change of threshold voltage was found to be larger in irradiated PMOS devices. However, if the radiation sensitivity is defined in the way authors did it, the results indicated NMOS rather than PMOS devices are more sensitive, specially at low doses. This is important from the standpoint of their possible application in dosimetry

  8. Comparison of risks due to bisphenol A and radiation with trad-MCN assay

    Shin, H. S.; Lee, J. H.; Kim, J. K.; Chon, K. J.; Lee, B. H.

    2001-01-01

    Many kinds of synthetic chemicals have been being used for various purposes. Some of them are called 'environmental hormones' because they can disturb the endocrine system of organisms. Presently no technique is established for the quantitative assessment of biological risk of the environmental hormones. The pollen mother cells (PMC) of Tradescantia are very sensitive to chemical toxicants or ionizing radiation, and thus can be used as a biological end-point assessing their effect. Micronucleus frequencies in PMC showed a good dose- and concentration-response relationship for radiation and bisphenol A. From the dose-response relationship, it is possible to estimate the equivalent bisphenol A concentration, or vice versa. One μM/ml of bisphenol A is equivalent to 1.8 cGy of radiation in the induction of micronuclei. It is known from the result that Trad-MCN assay can be an excellent tool for detection of biological risk due to environmental toxicants or synthetic chemicals

  9. Deep-water measurements of container ship radiated noise signatures and directionality.

    Gassmann, Martin; Wiggins, Sean M; Hildebrand, John A

    2017-09-01

    Underwater radiated noise from merchant ships was measured opportunistically from multiple spatial aspects to estimate signature source levels and directionality. Transiting ships were tracked via the Automatic Identification System in a shipping lane while acoustic pressure was measured at the ships' keel and beam aspects. Port and starboard beam aspects were 15°, 30°, and 45° in compliance with ship noise measurements standards [ANSI/ASA S12.64 (2009) and ISO 17208-1 (2016)]. Additional recordings were made at a 10° starboard aspect. Source levels were derived with a spherical propagation (surface-affected) or a modified Lloyd's mirror model to account for interference from surface reflections (surface-corrected). Ship source depths were estimated from spectral differences between measurements at different beam aspects. Results were exemplified with a 4870 and a 10 036 twenty-foot equivalent unit container ship at 40%-56% and 87% of service speeds, respectively. For the larger ship, opportunistic ANSI/ISO broadband levels were 195 (surface-affected) and 209 (surface-corrected) dB re 1 μPa 2 1 m. Directionality at a propeller blade rate of 8 Hz exhibited asymmetries in stern-bow (<6 dB) and port-starboard (<9 dB) direction. Previously reported broadband levels at 10° aspect from McKenna, Ross, Wiggins, and Hildebrand [(2012b). J. Acoust. Soc. Am. 131, 92-103] may be ∼12 dB lower than respective surface-affected ANSI/ISO standard derived levels.

  10. Interim report on the special research project 'exposure to environmental radiation due to nuclear facilities'

    1981-03-01

    This special research project was started in 1978 as five-year plan. The purposes are to clarify the aspect of radiation exposure in human bodies due to the radioactive substances brought into the environment regarding the utilization of atomic energy, its mechanism and various factors affecting it, and to contribute to the evaluation of exposure dose, the reduction of radiation exposure, the conditions of locating nuclear facilities and the improvement of the method of disposing radioactive wastes. In addition to the fields treated in the previous special research project, the experimental research concerning the metabolism of environmental radioactive nuclides in bodies, namely the problem of the peculiarity of radioactive nuclide kinetics in infants and fetuses different from adults and the possibility of causing the changes in the intake and metabolism of nuclides in foods by the difference in their states of existence, was newly included. Also the research concerning the method of evaluating the absorbed dose in human organs at the time of irradiation outside and inside bodies in a new subject. Accordingly, this special research project is composed of (1) the research concerning the radionuclide kinetics in the environment, (2) the research concerning the radionuclide kinetics in bodies, (3) the research concerning the measurement and evaluation of dose absorbed in internal organs due to environmental radiation, and (4) the research concerning the monitoring of low level environmental radiation. The results obtained so far are reported. (Kako, I.)

  11. The order for enforcing the law concerning prevention from radiation hazards due to radioisotopes

    1977-01-01

    The radioactive isotopes stipulated in Item 2, Article 2 of the Law Concerning Prevention from Radiation Hazards due to Radisotopes (hereinafter referred to as the Law) are the isotopes emitting radiation, their compounds, and those containing these isotopes or compounds. The radiation-generating apparatuses in Item 3, Article 2 of the Law are cyclotron, synchrotron, synchrocyclotron, linear accelerator, betatron, Van de Graaff accelerator, Cockcroft Walton accelerator, the apparatuses generating radiation by accelerating charged particles, which are designated by the Director of the Science and Technology Agency as necessary for preventing radiation injuries. Those who want to use, sell or dispose of radioactive isotopes should file applications for approval or notices with required documents. The approval should be obtained for each factory or place of business. The amount of completely sealed radioactive isotopes specified by the cabinet order stipulated in Item 1, Article 3-2 of the Law is 100 m curie per factory or place of business. Those who are going to change the approved items of the use, sale or disposal of radioactive isotopes should file applications. The amount of radioactive isotopes specified by the cabinet order stipulated in Item 5, Article 10 of the Law is 10 curies. Controlled areas, facilities for using, refilling, and storing isotopes, refilling and disposing wastes should meet the stipulated standards. (Rikitake, Y.)

  12. Radiation induced leakage due to stochastic charge trapping in isolation layers of nanoscale MOSFETs

    Zebrev, G. I.; Gorbunov, M. S.; Pershenkov, V. S.

    2008-03-01

    The sensitivity of sub-100 nm devices to microdose effects, which can be considered as intermediate case between cumulative total dose and single event errors, is investigated. A detailed study of radiation-induced leakage due to stochastic charge trapping in irradiated planar and nonplanar devices is developed. The influence of High-K insulators on nanoscale ICs reliability is discussed. Low critical values of trapped charge demonstrate a high sensitivity to single event effect.

  13. An intractable case of lower gastrointestinal hemorrhage due to radiation colitis. Usefulness of transcatheter arterial embolization

    Inoue, Koichi; Koyama, Tukasa [Yoka Hospital, Hyogo (Japan); Sugamura, Kenji; Ogawa, Toshihide [Tottori Univ., Yonago (Japan). Faculty of Medicine

    2003-05-01

    We tried transcatheter arterial embolization for lower gastrointestinal hemorrhage due to radiation colitis. In this case, colostomy and endoscopic therapy were not effective. We succeeded in arresting the hemorrhage without any complications. Transcatheter embolization is a low-invasive and safe method of treatment. For prevention of inflammation and iatrogenic abscess formation, we repeated this therapy and we tried arterial injection of antibiotics and steroid. And so, this therapy is one of the effective methods. (author)

  14. Paraplegia due to extramedullary hematopoiesis in thalassemia treated successfully with radiation therapy.

    Malik, Monica; Pillai, Lakshmi S; Gogia, Nidhi; Puri, Tarun; Mahapatra, M; Sharma, Daya Nand; Kumar, Rajat

    2007-03-01

    Spinal cord compression due to extramedullary hematopoiesis (EMH) is a rare complication of thalassemia and generally presents as paraparesis with sensory impairment. Complete paraplegia is extremely rare in EMH due to thalassemia although it is known to occur in polycythemia vera and sickle cell anemia. Treatment options mostly include surgery and/or radiotherapy. Whereas cases presenting with paraparesis have been treated with either surgery or radiotherapy with equal frequency and efficacy, almost all reported cases with paraplegia have been treated with surgery with or without radiation therapy. We hereby report a case of thalassemia intermedia with paraplegia treated successfully with radiotherapy.

  15. Methods for decreasing population doses due to medical use of ionizing radiations

    Marej, A.N.

    1984-01-01

    The problem of radiation safety of population as regard to irradiation of a great contingents of people due to diagnosis procedures, carried out using X-ray and radiological methods of examination, is considered. It is shown, that prevention from excessive irradiation of population due to X-ray radiodiagnostic procedures is possible by realization the complex of activities, including legislative, organizational, technical and other measures. Human exposure doses in diagnosis most not exceed permissible ones, established on the basis of cost-benefit criterion. The necessity of the maximum limitation of exposure of pregnant women and children is emphasized

  16. Turbulent boundary layer noise : direct radiation at Mach number 0.5

    Gloerfelt , Xavier; Berland , Julien

    2013-01-01

    International audience; Boundary layers constitute a fundamental source of aerodynamic noise. A turbulent boundary layer over a plane wall can provide an indirect contribution to the noise by exciting the structure, and a direct noise contribution. The latter part can play a significant role even if its intensity is very low, explaining why it is hardly measured unambiguously. In the present study, the aerodynamic noise generated by a spatially developing turbulent boundary layer is computed ...

  17. Medical Implications of Space Radiation Exposure Due to Low-Altitude Polar Orbits.

    Chancellor, Jeffery C; Auñon-Chancellor, Serena M; Charles, John

    2018-01-01

    Space radiation research has progressed rapidly in recent years, but there remain large uncertainties in predicting and extrapolating biological responses to humans. Exposure to cosmic radiation and solar particle events (SPEs) may pose a critical health risk to future spaceflight crews and can have a serious impact on all biomedical aspects of space exploration. The relatively minimal shielding of the cancelled 1960s Manned Orbiting Laboratory (MOL) program's space vehicle and the high inclination polar orbits would have left the crew susceptible to high exposures of cosmic radiation and high dose-rate SPEs that are mostly unpredictable in frequency and intensity. In this study, we have modeled the nominal and off-nominal radiation environment that a MOL-like spacecraft vehicle would be exposed to during a 30-d mission using high performance, multicore computers. Projected doses from a historically large SPE (e.g., the August 1972 solar event) have been analyzed in the context of the MOL orbit profile, providing an opportunity to study its impact to crew health and subsequent contingencies. It is reasonable to presume that future commercial, government, and military spaceflight missions in low-Earth orbit (LEO) will have vehicles with similar shielding and orbital profiles. Studying the impact of cosmic radiation to the mission's operational integrity and the health of MOL crewmembers provides an excellent surrogate and case-study for future commercial and military spaceflight missions.Chancellor JC, Auñon-Chancellor SM, Charles J. Medical implications of space radiation exposure due to low-altitude polar orbits. Aerosp Med Hum Perform. 2018; 89(1):3-8.

  18. The regulations for enforcing the law concerning prevention from radiation hazards due to radioisotopes

    1979-01-01

    The regulations are wholly revised under the law concerning prevention from radiation hazards due to radioisotopes and the provisions of the order for enforcing the law. Basic concepts and terms are defined, such as: employee engaged in radiation work; person regularly entering into the controlled area; the maximum permissible exposure dose; accumulative dose; the maximum permissible accumulative dose; the maximum permissible concentration in the air; the maximum permissible concentration under water; the maximum permissible surface density. The application for permission of the uses shall be made according to the form attached and include as appendix following documents: copy of register of the applicant legal person; plane drawings of the works or the enterprise and their surroundings in reduced scales and with directions, centering on facilities in use, of storage and disposal, etc. The report of the uses shall list name and address of the user, object and method of the uses, and include as annex copy of register of the user legal person and papers explaining the expected date of beginning and the period of the uses, etc. Standards of the uses, refilling, storage, transport and disposal are in detail stipulated. Specified measures shall be taken for measurement, prevention of radiation hazards, finding out of persons injured by radiation and others. (Okada, K.)

  19. Radiation exposure of population due to medical diagnostic procedures in the USSR

    Vorob'ev, E.I.; Stavitskij, R.V.; Knizhnikov, V.A.; Barkhudarov, R.M.; Korsunskij, V.N.; Popov, V.I.; Tarasenko, Yu.I.; Postnikov, V.A.; Frolov, N.V.; Sidorin, V.P.

    1984-01-01

    The evaluation of radiation doses to population in the ussr on the basis of the data on frequency of 12 main forms of X-ray examinations and the results of measuring absorbed doses on tissue-kquivalent main's phantom are given. The evaluation of radiation exposure due to radiopharmaceutical preparations is based on consumption of 26 types of compounds in 320 national laboratories and i is performed by the methods developed in the framework of the mird committee (usa). In thhe active bone marrow, lungs mammary, glands thyroid and other organs (stomach, liver, spleen, etc.) the equivalent doses are determined and on their base the effective equivalent doses (eed). The average eed from x ray diagnostic examinations is 1.4 mSv per year (140 mrem per year) of which 55.4% falls on X-ray examination, 26.9% on radiography, 17.7% on mass miniature radiography (fluorography). Radionuclide diagnostics contribution is 3.2x10 -2 mSv per year (3.8 mrem per year). Medicinal radiation exposure approximately doubles the natural background, it is comparable with exposure in premises and essentially exceeds the radiation doses to population from other sources

  20. H(10) due to radiation scattered in a 6 MV Linac for tomotherapy

    Vega C, H. R.; Esparza H, A.; Garcia R, M. G.; Reyes R, E.; Hernandez A, L.; Rivera, T.

    2017-10-01

    In order to determine the environmental equivalent dose (H(10)), due to the radiation that is dispersed over the body of a patient, 100 thermoluminescent dosimeters (TLD) around 6 MV TomoLINAC were used. The characteristics of the tomotherapy have the disadvantage that the shielding of the bunker increases considerably and for its design validated parameters are used for the conventional Linacs. In order to determine H(10) due to scattered radiation, measurements were made in the vicinity of the isocenter, while the 6 MeV photon beam was applied on a phantom. Also, TLDs were placed on the walls of the bunker that remained for 7 days, where approximately 50 patients were treated per day. At points close to the isocenter, the H(10) has an angular distribution caused by the phantom shape. In the bunker walls the highest H(10) was observed in the primary barriers. In the labyrinth, the impact of the scattered radiation was observed when measuring a greater value of the environmental equivalent dose in the wall furthest from the isocenter compared to the point located closest to it. (Author)

  1. Effect of Attitudinal, Situational and Demographic Factors on Annoyance Due to Environmental Vibration and Noise from Construction of a Light Rapid Transit System

    Daniel Wong-McSweeney

    2016-12-01

    Full Text Available The aim of this paper is to determine what non-exposure factors influence the relationship between vibration and noise exposure from the construction of a Light Rapid Transit (LRT system and the annoyance of nearby residents. Noise and vibration from construction sites are known to annoy residents, with annoyance increasing as a function of the magnitude of the vibration and noise. There is not a strong correlation between exposure and levels of annoyance suggesting that factors not directly related to the exposure may have an influence. A range of attitudinal, situational and demographic factors are investigated with the aim of understanding the wide variation in annoyance for a given vibration exposure. A face-to-face survey of residents (n = 350 near three sites of LRT construction was conducted, and responses were compared to semi-empirical estimates of the internal vibration within the buildings. It was found that annoyance responses due to vibration were strongly influenced by two attitudinal variables, concern about property damage and sensitivity to vibration. Age, ownership of the property and the visibility of the construction site were also important factors. Gender, time at home and expectation of future levels of vibration had much less influence. Due to the measurement methods used, it was not possible to separate out the effects of noise and vibration on annoyance; as such, this paper focusses on annoyance due to vibration exposure. This work concludes that for the most cost-effective reduction of the impact of construction vibration and noise on the annoyance felt by a community, policies should consider attitudinal factors.

  2. Modelling of the indirect radiation effect due to background aerosols in Austria

    Neubauer, D.

    2009-01-01

    by gases and particles. Built-in types of surface albedo as well as other values can be chosen. The radiative properties of the cloud depend on the single scattering properties of the cloud droplets, which in turn depend on the composition of the cloud droplets. In this study the cloud droplets are assumed to consist of water and black carbon. Different mixing types of black carbon in the cloud droplets are used for the calculations. The absorption of solar radiation of a cloud droplet can be significantly increased by black carbon. Sensitivity analysis showed that the radiative forcing due to the indirect effect depends strongly on the geometrical cloud thickness, shortwave surface albedo and on the rate of ascent. For 100 m cloud thickness, 0.35 m/s rate of ascent and a shortwave surface albedo of 0.35 (ice) the radiative forcing is -0.57 W/m 2 and -0.15 W/m 2 for a shortwave surface albedo of 0.9 (fresh snow), on average for the whole measurement campaign. Black carbon causes a positive forcing of 0.02 W/m 2 . (author) [de

  3. Risk estimates of stochastic effects due to exposure to radiation - a stochastic harm index

    Gonen, Y.G.

    1980-01-01

    The effects of exposure to low level radiation on the survival probability and life expectancy were investigated. The 1977 vital statistics of Jewish males in Israel were used as a baseline, mainly the data on normalized survival probability and life expectation as functions of age. Assumed effects of exposure were superposed on these data and the net differences calculated. It was found that the realistic rate effects of exposure to radiation are generally less than calculated by multiplying the collective dose by the risk factor. The effects are strongly age-dependent, decreasing sharply with age at exposure. The assumed harm due to exposure can be more than offset by improvements in medical care and safety. (H.K.)

  4. Validation of modelling the radiation exposure due to solar particle events at aircraft altitudes

    Beck, P.; Bartlett, D. T.; Bilski, P.; Dyer, C.; Flueckiger, E.; Fuller, N.; Lantos, P.; Reitz, G.; Ruehm, W.; Spurny, F.; Taylor, G.; Trompier, F.; Wissmann, F.

    2008-01-01

    Dose assessment procedures for cosmic radiation exposure of aircraft crew have been introduced in most European countries in accordance with the corresponding European directive and national regulations. However, the radiation exposure due to solar particle events is still a matter of scientific research. Here we describe the European research project CONRAD, WP6, Subgroup-B, about the current status of available solar storm measurements and existing models for dose estimation at flight altitudes during solar particle events leading to ground level enhancement (GLE). Three models for the numerical dose estimation during GLEs are discussed. Some of the models agree with limited experimental data reasonably well. Analysis of GLEs during geomagnetically disturbed conditions is still complex and time consuming. Currently available solar particle event models can disagree with each other by an order of magnitude. Further research and verification by on-board measurements is still needed. (authors)

  5. The burden of occupationally-related cutaneous malignant melanoma in Britain due to solar radiation.

    Rushton, Lesley; J Hutchings, Sally

    2017-02-14

    Increasing evidence highlights the association of occupational exposure and cutaneous malignant melanoma (CMM). We estimated the burden of CMM and total skin cancer burden in Britain due to occupational solar radiation exposure. Attributable fractions (AF) and numbers were estimated for CMM mortality and incidence using risk estimates from the published literature and national data sources for proportions exposed. We extended existing methods to account for the exposed population age structure. The estimated total AF for CMM is 2.0% (95% CI: 1.4-2.7%), giving 48 (95% CI: 33-64) deaths in (2012) and 241 (95% CI: 168-325) registrations (in 2011) attributable to occupational exposure to solar radiation. Higher exposure and larger numbers exposed led to much higher numbers for men than women. Industries of concern are construction, agriculture, public administration and defence, and land transport. These results emphasise the urgent need to develop appropriate strategies to reduce this burden.

  6. The state of enforcement of the Law Concerning Prevention from Radiation Hazards Due to Radioisotopes, etc

    1978-01-01

    In recent years, the uses of radioisotopes and radiation generators have advanced remarkably in Japan. The establishments utilizing them are on rapid increase in industries, medicine, research and education. Furthermore, since the types of usage are more diversified, the kinds of radioisotopes and their quantities are also increasing. In this connection, The Law Concerning Prevention from Radiation Hazards Due to Radioisotopes, etc. has been in force for about twenty years. Under the current situation in this field, importance of the administration concerning enforcement of The Law is ever rising. In the Science and Technology Agency, in view of the occurrence of accidents in certain enterprises, starting in fiscal 1974, various measures have been taken. As the state of enforcement of The Law, the following matters are presented; the establishments using, selling and disposing of radioisotopes, etc. up to fiscal 1977 (in tables); and variety of governmental measures taken by the Agency. (Mori, K.)

  7. Age-dependent radiation dose due to intake of uranium through drinking water in India

    Sahoo, S.K.; Mohapatra, S.; Chakrabarty, A.; Sumesh, C.G.; Tripathi, R.M.; Puranik, V.D.

    2009-01-01

    In the present study, an attempt has been made to estimate the content of uranium in drinking water in various states of India by laser fluorimetry. Depending upon the rate of water intake for the different age groups, the associated radiation dose was calculated. The concentration of uranium varied between 0.1 ± 0.01 and 19.6 ± 1.8 ppb which is much lower than the drinking water guideline value of 60 ppb. The total radiation dose due to ingestion of uranium through drinking water for various age groups is found to vary from 0.14 μSv/y to 48 μSv/y. (author)

  8. Changes in developmental stages of the egyptian lizard chalcides ocellatus due to different radiation exposures

    Roushdy, H.M.; Mazhar, Fatma M.; Ashry, Madiha A.; Refaat, Sanaa M.

    1979-01-01

    Adult male and female Chalcides Ocellatus lizards of approximately the same age and size were irradiated at doses of 1000, 1500, 2000 and 4000 rads from a Cobalt-60 Gamma cell at a dose rate of 100 rads/sec. Examinations were carried out at 2 days, 1, 3 and 4 weeks post-irradiation and indicated the following: The LD 50 /30 was found to be 1250 rads. Radiation exposure had no significant effect on lizard's body length measurements along the whole experimentation period. Radiation exposure caused a progressive decrease in body weights of lizards which was often obscured by interfering fluctuations in body weights due to pregnancy development, embryo retention or abortion cases

  9. Remanent radiation fields around medical linear accelerators due to the induced radionuclides

    Sabol, J.; Khalifa, O.; Berka, Z.; Stankus, P.; Frencl, L.

    1998-01-01

    Radiation fields around two linear accelerators, Saturn 43 and a Saturn 2 Plus, installed at radiotherapy department is Prague, were measured and interpreted. The measurements included the determination of the dose equivalent rate resulting from photons emitted by induced radionuclides produced in reactions of high-energy photons with certain elements present in air and accelerator components as well as in the shielding and building materials in the treatment rooms, which are irradiated by high-energy X-rays, and due to radionuclides formed by capture of photoneutrons. While scattered photons and photoneutrons are only present during the accelerator operation, residual radioactivity creates a remanent radiation field persisting for some time after the instrument shutdown. The activity induced in the accessories is also an important source of exposure. (P.A.)

  10. A case of perforative peritonitis due to radiation enteritis 33 years after radiotherapy

    Takaya, Yoshihiro; Yasaka, Takahiro; Fujiwara, Shinsuke [Kamigotou Hospital, Nagasaki (Japan)

    2001-11-01

    We report a case of perforative peritonitis due to radiation enteritis. An 88-year-old woman who had undergone pelvic irradiation for a gynecological malignancy was referred to our hospital due to hematomesis and epigastralgia with fever. We determined that she had perforative peritonitis, based on intraabdominal extrabowel gases in abdominal computed tomography. We conducted emergency operation to resect the damaged bowel, such as necrotic intestine combound with a damaged bladder in ''frozen pelvis'' and reconstruct jejuno-ascending colostomy. Pathological findings for resected specimens were compatible with radiation enteritis, such as excessive collagen deposition within the bowel wall, vasculitis, and intramural edema. The woman had a jejuno-subcutaneous fistula and suffered recurrent urinary infection or jaundice due to chronic hepatitis C after the surgical procedure. But eight months later, recovery enabled a successful second laparotomy to reconstruct the residual intestine. Even long after irradiation for malignant disease, radioactive damage to the body as a whole should always be considered. (author)

  11. Indoor noise annoyance due to 3-5 megawatt wind turbines-An exposure-response relationship.

    Hongisto, Valtteri; Oliva, David; Keränen, Jukka

    2017-10-01

    The existing exposure-response relationships describing the association between wind turbine sound level and noise annoyance concern turbine sizes of 0.15-3.0 MW. The main purpose of this study was to determine a relationship concerning turbines with nominal power of 3-5 MW. A cross-sectional survey was conducted around three wind power areas in Finland. The survey involved all households within a 2 km distance from the nearest turbine. Altogether, 429 households out of 753 participated. The households were exposed to wind turbine noise having sound levels within 26.7-44.2 dB L Aeq . Standard prediction methods were applied to determine the sound level, L Aeq , in each participant's yard. The measured sound level agreed well with the predicted sound level. The exposure-response relationship was derived between L Aeq outdoors and the indoor noise annoyance. The relationship was in rather good agreement with two previous studies involving much smaller turbines (0.15-1.5 MW) under 40 dB L Aeq . The Community Tolerance Level (CTL), CTL 20  = 50 dB, was 3 dB lower than for two previous studies. Above 40 dB, a small number of participants prevented a reliable comparison to previous studies.

  12. Additional radiation dose to population due to X-ray diagnostic procedures

    Chougule, A.

    2006-01-01

    entrance skin dose (mGy) received by the patient during the radiological procedure will be presented in the paper. From the population of the region, the frequency of radiological procedures/person/year is estimated and in the present study it worked out to be 10,500-procedures/ year/100,000 population. From the data collected, estimation of additional contribution of radiation dose to population due to X ray diagnostic procedures was done. In present st udy it was found that the contribution of radiation dose due to radiological procedure to population is 0.22 mSv/year/person. The UNSCEAR (2000) reported the 1.2 mSv as mean effective dose per capita due to medical X ray examinations in developed countries where frequency of x ray procedure is much higher as compared to India. The results in detail are discussed in this communication. (author)

  13. Study of the effects of radiation on prevention of gynaecomastia due to oestrogen therapy

    Waterfall, N B; Glaser, M G [Charing Cross Group of Hospitals, London (UK)

    1979-09-01

    A study of the effects of irradiation in prevention of gynaecomastia due to oestrogen therapy for carcinoma is reported. Twenty patients were treated with oestrogens without radiotherapy, of these 17 developed gynaecomastia. Twenty-seven patients were treated with radiotherapy prior to oestrogens, of these only 3 developed gynaecomastia. Previous studies have shown similar results but have used larger doses of irradiation and recommended a delay of 1 month between radiotherapy and treatment. In this study a low dose of radiation was used and oestrogens were started immediately after radiotherapy.

  14. Comparison of noise power spectrum methodologies in measurements by using various electronic portal imaging devices in radiation therapy

    Son, Soon Yong [Dept. of Radiological Technology, Wonkwang Health Science University, Iksan (Korea, Republic of); Choi, Kwan Woo [Dept. of Radiology, Asan Medical Center, Seoul (Korea, Republic of); Jeong, Hoi Woun [Dept. of Radiological Technology, Baekseok Culture University College, Cheonan (Korea, Republic of); Kwon, Kyung Tae [Dep. of Radiological Technology, Dongnam Health University, Suwon (Korea, Republic of); Kim, Ki Won [Dept. of Radiology, Kyung Hee University Hospital at Gang-dong, Seoul (Korea, Republic of); Lee, Young Ah; Son, Jin Hyun; Min, Jung Whan [Shingu University College, Sungnam (Korea, Republic of)

    2016-03-15

    The noise power spectrum (NPS) is one of the most general methods for measuring the noise amplitude and the quality of an image acquired from a uniform radiation field. The purpose of this study was to compare different NPS methodologies by using megavoltage X-ray energies. The NPS evaluation methods in diagnostic radiation were applied to therapy using the International Electro-technical Commission standard (IEC 62220-1). Various radiation therapy (RT) devices such as TrueBeamTM(Varian), BEAMVIEWPLUS(Siemens), iViewGT(Elekta) and ClinacR iX (Varian) were used. In order to measure the region of interest (ROI) of the NPS, we used the following four factors: the overlapping impact, the non-overlapping impact, the flatness and penumbra. As for NPS results, iViewGT(Elekta) had the higher amplitude of noise, compared to BEAMVIEWPLUS (Siemens), TrueBeamTM(Varian) flattening filter, ClinacRiXaS1000(Varian) and TrueBeamTM(Varian) flattening filter free. The present study revealed that various factors could be employed to produce megavoltage imaging (MVI) of the NPS and as a baseline standard for NPS methodologies control in MVI.

  15. Report on the project research 'exposure to environmental radiation due to nuclear facilities'

    1984-03-01

    This special research was carried out for five years from fiscal 1978 to fiscal 1982, and its constitution was as follows: the investigation research on the behavior of radioactive substances in ocean and land environments, the investigation research on the metabolism of radioactive substances within bodies, the measurement of the dose absorbed in organs due to environmental radiation and the evaluation, and the investigation research on low level environmental radiation monitoring. As the sources of environmental radiation exposure, not only the release into the atmosphere and sea from nuclear power stations, nuclear fuel reprocessing plants and other facilities, but also the disposal of radioactive wastes on land and into ocean were considered. As the method of research, the experiment using living things and others, the analysis of the fallout nuclides existing in environment and living things, the analysis of the results of quantitative determination of stable elements and others were used. The detailed results of the above described researches are reported. By having executed this special research, the accumulation of new knowledge was obtained on the behavior of radioactive nuclides in environment and living things. (Kako, I.)

  16. Pediatric CT: implementation of ASIR for substantial radiation dose reduction while maintaining pre-ASIR image noise.

    Brady, Samuel L; Moore, Bria M; Yee, Brian S; Kaufman, Robert A

    2014-01-01

    To determine a comprehensive method for the implementation of adaptive statistical iterative reconstruction (ASIR) for maximal radiation dose reduction in pediatric computed tomography (CT) without changing the magnitude of noise in the reconstructed image or the contrast-to-noise ratio (CNR) in the patient. The institutional review board waived the need to obtain informed consent for this HIPAA-compliant quality analysis. Chest and abdominopelvic CT images obtained before ASIR implementation (183 patient examinations; mean patient age, 8.8 years ± 6.2 [standard deviation]; range, 1 month to 27 years) were analyzed for image noise and CNR. These measurements were used in conjunction with noise models derived from anthropomorphic phantoms to establish new beam current-modulated CT parameters to implement 40% ASIR at 120 and 100 kVp without changing noise texture or magnitude. Image noise was assessed in images obtained after ASIR implementation (492 patient examinations; mean patient age, 7.6 years ± 5.4; range, 2 months to 28 years) the same way it was assessed in the pre-ASIR analysis. Dose reduction was determined by comparing size-specific dose estimates in the pre- and post-ASIR patient cohorts. Data were analyzed with paired t tests. With 40% ASIR implementation, the average relative dose reduction for chest CT was 39% (2.7/4.4 mGy), with a maximum reduction of 72% (5.3/18.8 mGy). The average relative dose reduction for abdominopelvic CT was 29% (4.8/6.8 mGy), with a maximum reduction of 64% (7.6/20.9 mGy). Beam current modulation was unnecessary for patients weighing 40 kg or less. The difference between 0% and 40% ASIR noise magnitude was less than 1 HU, with statistically nonsignificant increases in patient CNR at 100 kVp of 8% (15.3/14.2; P = .41) for chest CT and 13% (7.8/6.8; P = .40) for abdominopelvic CT. Radiation dose reduction at pediatric CT was achieved when 40% ASIR was implemented as a dose reduction tool only; no net change to the magnitude

  17. Pediatric cT: Implementation of ASIR for Substantial Radiation Dose Reduction While Maintaining Pre-ASIR Image Noise1

    Brady, Samuel L.; Moore, Bria M.; Yee, Brian S.; Kaufman, Robert A.

    2015-01-01

    Purpose To determine a comprehensive method for the implementation of adaptive statistical iterative reconstruction (ASIR) for maximal radiation dose reduction in pediatric computed tomography (CT) without changing the magnitude of noise in the reconstructed image or the contrast-to-noise ratio (CNR) in the patient. Materials and Methods The institutional review board waived the need to obtain informed consent for this HIPAA-compliant quality analysis. Chest and abdominopelvic CT images obtained before ASIR implementation (183 patient examinations; mean patient age, 8.8 years ± 6.2 [standard deviation]; range, 1 month to 27 years) were analyzed for image noise and CNR. These measurements were used in conjunction with noise models derived from anthropomorphic phantoms to establish new beam current–modulated CT parameters to implement 40% ASIR at 120 and 100 kVp without changing noise texture or magnitude. Image noise was assessed in images obtained after ASIR implementation (492 patient examinations; mean patient age, 7.6 years ± 5.4; range, 2 months to 28 years) the same way it was assessed in the pre-ASIR analysis. Dose reduction was determined by comparing size-specific dose estimates in the pre- and post-ASIR patient cohorts. Data were analyzed with paired t tests. Results With 40% ASIR implementation, the average relative dose reduction for chest CT was 39% (2.7/4.4 mGy), with a maximum reduction of 72% (5.3/18.8 mGy). The average relative dose reduction for abdominopelvic CT was 29% (4.8/6.8 mGy), with a maximum reduction of 64% (7.6/20.9 mGy). Beam current modulation was unnecessary for patients weighing 40 kg or less. The difference between 0% and 40% ASIR noise magnitude was less than 1 HU, with statistically nonsignificant increases in patient CNR at 100 kVp of 8% (15.3/14.2; P = .41) for chest CT and 13% (7.8/6.8; P = .40) for abdominopelvic CT. Conclusion Radiation dose reduction at pediatric CT was achieved when 40% ASIR was implemented as a dose

  18. Shielding effect of snow cover on indoor exposure due to terrestrial gamma radiation

    Fujimoto, Kenzo; Kobayashi, Sadayoshi

    1988-01-01

    Many people in the world live in high latitude region where it snows frequently in winter. When snow covers the ground, it considerably reduces the external exposure from the radiation sources in the ground. Therefore, the evaluation of snow effect on exposure due to terrestrial gamma radiation is necessary to obtain the population dose as well as the absorbed dose in air in snowy regions. Especially the shielding effect on indoor exposure is essentially important in the assessment of population dose since most individuals spend a large portion of their time indoors. The snow effect, however, has been rather neglected or assumed to be the same both indoors and outdoors in the population dose calculation. Snow has been recognized only as a cause of temporal variation of outdoor exposure rate due firstly to radon daughters deposition with snow fall and secondly to the shielding effect of snow cover. This paper describes an approach to the evaluation of shielding effect of snow cover on exposure and introduces population dose calculation as numerical example for the people who live in wooden houses in Japan

  19. Public radiation exposure due to radon transport from a uranium mine

    Akber, R.A.; Johnston, A.; Pfitzner, J.

    1992-01-01

    Radon and radon daughter concentrations at locations several kilometres away from a uranium mine are due both to the background sources and the mine-related sources. The contribution of these two types of sources should be distinguished because the authorised limits on public radiation dose apply only to the mine-related sources. Such a distinction can be achieved by measuring radon and radon daughter concentration in the wind sectors containing only the background sources and those in the wind sectors containing both the background and the mine-related sources. This approach has been used to make estimates of public radiation dose due to radon transport from the Ranger Uranium Mine in Australia. The residential town of Jabiru, the non-residential working town of Jabiru East, and the aboriginal camp sites in the vicinity of the mine were considered. The results indicate that, for the groups of population considered, the annual mine-related dose varies between 0.04 and 0.2 mSv. (author)

  20. Momentum accumulation due to solar radiation torque, and reaction wheel sizing, with configuration optimization

    Hablani, Hari B.

    1993-01-01

    This paper has a two-fold objective: determination of yearly momentum accumulation due to solar radiation pressure, and optimum reaction wheel sizing. The first objective is confronted while determining propellant consumption by the attitude control system over a spacecraft's lifetime. This, however, cannot be obtained from the daily momentum accumulation and treating that constant throughout the year, because the orientation of the solar arrays relative to the spacecraft changes over a wide range in a year, particularly if the spacecraft has two arrays, one normal and the other off-normal to different extent at different times to the sun rays. The paper first develops commands for the arrays for tracking the sun, the arrays articulated to earth-pointing spacecraft with two rotational degrees of freedom, and spacecraft in an arbitrary circular orbit. After developing expressions for solar radiation torque due to one or both arrays, arranged symmetrically or asymmetrically relative to the spacecraft bus, momentum accumulation over an orbit and then over a year are determined. The remainder of the paper is concerned with designing reaction wheel configurations. Four-, six-, and three-wheel configurations are considered, and for given torque and momentum requirements, their cant angles with the roll/yaw plane are optimized for minimum power consumption. Finally, their momentum and torque capacities are determined for one-wheel failure scenario, and six configurations are compared and contrasted.

  1. ENHANCEMENT OF NOISE LEVEL IN URBAN ENVIRONMENT DUE TOURIST ACTIVITIES: A CASE STUDY IN THE CITY OF CAMPOS DO JORDÃO

    Luiz Antonio Brito

    2014-12-01

    Full Text Available The excess of noise in large cities is a recurrent situation which creates irritability, loss of efficiency at work and loss of life quality, in such way that the silence and the tranquility of smaller cities end up being a touristic appeal. But, at the same time, the touristic activities have great potential of generating noise energy, which leads to a conflicting situation. The city of Campos de Jordão, nationally known for its cool climate, European architecture and sophisticated gastronomy, is popular among people who seek both tranquility and entertainment. The objective of this assignment is to evaluate the urban impact created by the increase of noise energy due to touristic activities in the city of Campos do Jordão. Thus, measurement of sound pressure levels were carried out on holidays and working days in 15 chosen spots. The results showed a considerable elevation of noise levels, even in areas away from touristic zones. This condition tends to move hotels and inns away from the touristic zone of the city, which demands investments in infrastructure, burdening the local government.

  2. Oxidative stress due to radiation in CD34+ hematopoietic progenitor cells. Protection by IGF-1

    Floratou, K.; Karakantza, M.; Giannopoulou, E.; Antonacopoulou, A.; Adonakis, G.; Kardamakis, D.; Matsouka, P.

    2012-01-01

    Radiation exerts direct as well as indirect effects on DNA through the generation of reactive oxygen species (ROS). Irradiated hematopoietic progenitor cells (HPCs) experience DNA strand breaks, favoring genetic instability, due to ROS generation. Our aim was to study the effect of a range of radiation doses in HPCs and the possible protective mechanisms activated by insulin-like growth factor-1 (IGF-1). ROS generation was evaluated, in the presence or absence of IGF-1 in liquid cultures of human HPCs-CD34 + irradiated with 1-, 2- and 5-Gy X-rays, using a flow cytometry assay. Manganese superoxide dismutase (MnSOD) expression was studied by western blot analysis and visualized by an immunofluorescence assay. Apoptosis was estimated using the following assays: Annexin-V assay, DNA degradation assay, BCL-2/BAX mRNA and protein levels and caspase-9 protein immunofluorescence visualization. Viability and clonogenic potential were studied in irradiated HPCs. The generation of superoxide anion radicals at an early and a late time point was increased, while the hydrogen peroxide generation at a late time point was stable. IGF-1 presence further enhanced the radiation-induced increase of MnSOD at 24 h post irradiation. IGF-1 inhibited the mitochondria-mediated pathway of apoptosis by regulating the m-RNA and protein expression of BAX, BCL-2 and the BCL-2/BAX ratio and by decreasing caspase-9 protein expression. IGF-1 presence in culture media of irradiated cells restored the clonogenic capacity and the viability of HPCs as well. In conclusion, IGF-1 protects HPCs-CD34 + from radiation effects, by eliminating the oxidative microenvironment through the enhancement of MnSOD activation and by regulating the mitochondria-mediated pathway of apoptosis. (author)

  3. All-theoretical prediction of cabin noise due to impingement of propeller vortices on a wing structure

    Martinez, R.; Cole, J. E., III; Martini, K.; Westagard, A.

    1987-01-01

    Reported calculations of structure-borne cabin noise for a small twin engine aircraft powered by tractor propellers rely on the following three-stage methodological breakup of the problem: (1) the unsteady-aerodynamic prediction of wing lift harmonics caused by the whipping action of the vortex system trailed from each propeller; (2) the associated wing/fuselage structural response; (3) the cabin noise field for the computed wall vibration. The first part--the estimate of airloads--skirts a full-fledged aeroelastic situation by assuming the wing to be fixed in space while cancelling the downwash field of the cutting vortices. The model is based on an approximate high-frequency lifting-surface theory justified by the blade rate and flight Mach number of application. Its results drive a finite-element representation of the wing accounting for upper and lower skin surfaces, spars, ribs, and the presence of fuel. The fuselage, modeled as a frame-stiffened cylindrical shell, is bolted to the wing.

  4. Status of radiation dose and radioactive contamination due to the Fukushima accident

    Baba, Mamoru

    2016-01-01

    The accident at Fukushima Daiichi Nuclear Power Plant (NPP), March 2011, caused serious radioactive contamination over wide area in east Japan. Therefore, it is important to know the effect of the accident and the status of NPP. This paper provides a review on the status of radiation dose and radioactive contamination caused by the accident on the basis of publicized information. Monitoring of radiation dose and exposure dose of residents has been conducted extensively by the governments and various organizations. The effective dose of general residents due to the accident proved to be less than a mSv both for external and internal dose. The equivalent committed dose of thyroid was evaluated to be a few mSv in mean value and less than 50 mSv even for children. Monitoring of radioactivity concentration has been carried out on food ingredients, milk and tap water, and actual meal. These studies indicated the percentage of foods above the regulation standard was over 10% in 2011 but decreasing steadily with time. The internal dose due to foods proved to be tens of μSv and much less than that due to natural 40 K even in the Fukushima area and decreasing steadily, although high level concentration is still observed in wild plants, wild mushrooms, animals and some kind of fishes. According to extensive studies, not only the effect of the accident but also the pathway and countermeasures against radioactive contamination have been revealed, and they are applied very effectively for restoration of environment and reconstruction of the area

  5. Status of radiation dose and radioactive contamination due to the Fukushima accident

    Baba, Mamoru [Tohoku Univeristy, Sendai (Japan)

    2016-06-15

    The accident at Fukushima Daiichi Nuclear Power Plant (NPP), March 2011, caused serious radioactive contamination over wide area in east Japan. Therefore, it is important to know the effect of the accident and the status of NPP. This paper provides a review on the status of radiation dose and radioactive contamination caused by the accident on the basis of publicized information. Monitoring of radiation dose and exposure dose of residents has been conducted extensively by the governments and various organizations. The effective dose of general residents due to the accident proved to be less than a mSv both for external and internal dose. The equivalent committed dose of thyroid was evaluated to be a few mSv in mean value and less than 50 mSv even for children. Monitoring of radioactivity concentration has been carried out on food ingredients, milk and tap water, and actual meal. These studies indicated the percentage of foods above the regulation standard was over 10% in 2011 but decreasing steadily with time. The internal dose due to foods proved to be tens of μSv and much less than that due to natural {sup 40}K even in the Fukushima area and decreasing steadily, although high level concentration is still observed in wild plants, wild mushrooms, animals and some kind of fishes. According to extensive studies, not only the effect of the accident but also the pathway and countermeasures against radioactive contamination have been revealed, and they are applied very effectively for restoration of environment and reconstruction of the area.

  6. Radiation dose in critical organs due to non-coplanar irradiation of the pituitary gland

    Schulte, R.W.M.; Rittmann, K.L.; Meinass, H.J.; Rennicke, P.

    1996-01-01

    In order to estimate the somatic and genetic risk associated with a non-coplanar linac-based radiation technique of the pituitary gland, systematic secondary-dose measurements in a phantom and sample measurements of the dose near critical organs of patients were performed. For measurements of the dose outside the primary radiation field an acrylic-PVC phantom was used which was irradiated with a single field (4x4 cm 2 ). Eight patients with pituitary tumors were treated isocentrically with a combination of sagittal and transverse rotational arcs. To measure the dose in critical organs, LiF thermoluminescence dosimeters (TLD) in chip form were placed onto 1 eyelid, the skin over the thyroid, and the patient's clothes covering the region of breasts and ovaries of female patients and the testicles of male patients. Measurements were performed for all patients during 1 sagittal irradiation and for the majority of patients during 1 transverse irradiation. The phantom measurements demonstrated that the secondary dose measured on the patients surface can be considered as a good approximation for the dose in adjacent organs. The median dose in critical organs for sagittal irradiation was in the range of 25.8 mGy (eyes) to 1.9 mGy (testicles), and for transverse irradiation in the range of 23.3 mGy (eyes) to 1.3 mGy (testicles). The ratio of median organ doses for sagittal and transverse irradiation was 2.1 for the thyroid gland, 1.1 for the eyes, and 1.5 for the other organs. The dose in critical organs due to non-coplanar irradiation of the pituitary gland is only a small fraction of the dose delivered to the reference point of the planning target volume. The risk of a radiation-induced tumor and a genetic consequence associated with these small doses is generally less than 1% and 0.1%, respectively. (orig./MG) [de

  7. Radiation Risk due to the Presence of Cs-137 in Fertilizers

    Shweikani, R.; Hushari, M.

    2003-01-01

    In this work radiation doses arising from using fertilizers containing Cs-137 with activity concentration equal to the exempted level set by IAEA (BSS-115) were studied. It was assumed that the amount of fertilizers are added yearly, for 50 sequence years, to soil is about 16 kg/1000m 2 and this amount is mixed with the top 15cm of the soil. Al-Gab area was considered for this study (area 900km 2 and about 600000 inhabitant). RESRAD a computer code, which was developed by the American Agency for Environmental Protection (EPA) to calculate individual radiation dose from contaminated sites, was used. The concerned population was divided into subgroups for better assessment for individual dose. The results showed that the maximum yearly dose could be received by individual how lives and eat from the products of his land dose not exceed 11 μSv/y after 50 years of consecutive additions, and will reach a maximum value of about 16 μSv/y for 250 years. More than 90% of this dose is due to external gamma exposure

  8. A case of generalized peritonitis due to a rupture of the bladder caused by radiation cystitis

    Fujitake, Shin-ichi; Nozaki, Hideki; Shimizu, Minoru; Maeda, Yoshiyuki; Kataoka, Susumu

    1999-01-01

    An 83-year-old woman was admitted to the department of gastroenterology in our hospital with a diagnosis of adhesive ileus following operation for a uterine cancer on July 22, 1997. Conservative therapy was started, but three days later, peritoneal signs appeared and white blood cell count and CRP level increased. An emergency operation was performed. Upon laparotomy, there were a large volume of ascites and a rupture of the bladder of which wall had become fragile. It was thought that the cause of rupture might result from radiation cystitis because she received irradiation after operation for the uterine cancer. Ruptured site of the bladder was sutured. Possible causes of the ileus were thought to be intestinal paralysis due to generalized peritonitis and a narrowing of the ileum where inflammatory change was remarkable. For this, an excision of the ileum with ileostomy was performed. Thereafter a closure of the ileostomy and ileocolostomy were carried out. The patient had difficulty in management of evacuation for a while, but she was discharged on March 2, 1998. Spontaneous rupture of the bladder is rare. This paper presents such a rare case caused by radiation cystitis, together with 14 cases reported in Japan. It is thought that surgeons who manage acute abdomen may encounter the disease. (author)

  9. Radiation risk due to the presence of Cs-137 in fertilizers

    Shweikani, R

    2003-01-01

    In this work radiation doses arising from using fertilizers containing Cs-137 with activity concentration equal to the exempted level set by IAEA (BSS-115) were studied. It was assumed that the amount of fertilizers are added yearly, for 50 sequence years and continues adding for unlimited years, to soil is about 16 kg/1000m sup 2 and this amount is mixed with the top 15 cm of the soil. Al-Gab area was considered for this study (area 900km sup 2 and about 600000 inhabitant). RESRAD a computer code, which was developed by the American Agency for Environmental Protection (EPA) to calculate individual radiation dose from contaminated sites, was used. The concerned population was divided into subgroups for better assessment for individual dose. The results showed that the maximum yearly dose could be received by individual who lives and eats from the products of his land does not exceed 11 mu Sv/y after 50 years of consecutive additions and 16 mu Sv/y after 250 years, and more than 90% of this dose is due to exte...

  10. Radiation risk in Finland due to the nuclear power plant at Sosnovyj Bor

    Ilvonen, M.; Rossi, J.; Salonoja, M.

    1994-06-01

    The present study is an application of the long range transport and dose model TRADOS developed jointly by the Finnish Meteorological Institute and Technical Research Centre of Finland. The aim of the study is to assess the radiation risk in Finland due to the nuclear power plant at Sosnovyj Bor near St. Petersburg in Russia. Probabilities of reaching different parts of the country, transport time and time spent over Finland by the trajectories are presented. Also breadth of the radioactive cloud and incidence of rain are estimated. The calculated radiation doses are based on one single hypothetical release, in which all noble gases are released, together with 10 % of easily vaporizing elements and 1 % of others. All results are based on the assumption that the probability of the release is 100 %. The dose pathways calculated are cloud gamma, fallout gamma, inhalation, and ingestion of milk, meat, green vegetables, grain and roots. External dose rates have been calculated. The necessity of countermeasures and the ratio of the avertable dose to the costs are also assessed. (13 refs., 156 figs., 12 tabs.)

  11. A case of generalized peritonitis due to a rupture of the bladder caused by radiation cystitis

    Fujitake, Shin-ichi; Nozaki, Hideki; Shimizu, Minoru; Maeda, Yoshiyuki; Kataoka, Susumu [Meitetsu Hospital, Nagoya (Japan)

    1999-03-01

    An 83-year-old woman was admitted to the department of gastroenterology in our hospital with a diagnosis of adhesive ileus following operation for a uterine cancer on July 22, 1997. Conservative therapy was started, but three days later, peritoneal signs appeared and white blood cell count and CRP level increased. An emergency operation was performed. Upon laparotomy, there were a large volume of ascites and a rupture of the bladder of which wall had become fragile. It was thought that the cause of rupture might result from radiation cystitis because she received irradiation after operation for the uterine cancer. Ruptured site of the bladder was sutured. Possible causes of the ileus were thought to be intestinal paralysis due to generalized peritonitis and a narrowing of the ileum where inflammatory change was remarkable. For this, an excision of the ileum with ileostomy was performed. Thereafter a closure of the ileostomy and ileocolostomy were carried out. The patient had difficulty in management of evacuation for a while, but she was discharged on March 2, 1998. Spontaneous rupture of the bladder is rare. This paper presents such a rare case caused by radiation cystitis, together with 14 cases reported in Japan. It is thought that surgeons who manage acute abdomen may encounter the disease. (author)

  12. Overexposure of patients due to malfunctions or defects in radiation equipment

    Gill, J.R.

    1992-01-01

    Some 38 incidents involving patient overexposure due to malfunctions or defects in radiation equipment were notified to HSE between 1986 and 1990. Of these cases, 30 involved diagnostic X ray equipment, while the remainder involved nuclear medicine or radiotherapy equipment. Those cases involving X ray equipment are examined in detail and grouped into six categories. The numbers of patients affected varied. In one case an estimated 350 patients were affected: in another, 240; while 13 cases affected only a single patient. A very rough estimate of the collective effective dose equivalent in the 30 cases comes to 5 man sieverts. It is concluded that improvements are needed in fault finding procedures, and guidance is needed on consistent methods of dose estimation and reporting. Improvements for the longer term include the selection of reliable components during manufacture; application of HSE guidance in software design for programmable electronic systems; and equipment design to incorporate fault detection and inhibition of operation to prevent excessive exposures

  13. Acoustic radiation due to gust-airfoil and blade-vortex interactions

    Agarwal, R.K. [Wichita State Univ., KS (United States). National Inst. for Aviation Research

    2001-07-01

    An accurate and efficient method for computing acoustic radiation due to gust-airfoil and blade-vortex interactions is developed. In these types of problems, sound is generated as a result of interaction between the unsteadiness in the flow and the body. The acoustic governing equations are derived by linearizing the compressible unsteady Euler equations about the steady mean flow. From these equations, the frequency domain acoustic equations are obtained assuming a single frequency disturbance. The equations are solved by employing a multi-stage Runge-Kutta finite-volume time-stepping scheme with a fourth-order compact spatial discretization. In the farfield, both the Giles' nonreflecting boundary condition and the perfectly matched layer (PML) absorbing boundary conditions are employed. This report describes the technical approach and shows the results calculated for the interactions. (orig.)

  14. Enhancement of natural radiation and population exposures due to the activity of large steelworks

    Niewiadomski, T; Godek, J; Jasinska, M; Wasiolek, P [Institute of Nuclear Physics, Krakow (Poland)

    1984-09-01

    Radionuclide releases and resulting population exposures from large industrial plants have recently become a subject of some public concern. Methods for assessing these effects were developed and, as an example, a complex of large steelworks located in the vicinity of the city of Krakow was investigated. The following critical pathways were considered: atmospheric release, and use of fly ash for production of building materials. For assessing annual average radionuclide concentrations in air and in soil around the works, a computer program was developed while other mathematical methods were applied to the assessment of maximum individual effective dose equivalent commitments (EDEC) due to inhalation, ingestion, and external gamma radiation. In order to acquire data for calculations many samples of raw materials, coal, ash, and dust were analysed as to their radionuclide concentration. The total individual EDEC at the place of maximum immission was estimated to be about 100 ..mu..Sv a/sup -1/ (i.e., about 6% of the natural exposure in this region), this being mainly due to ingestion (ca. 65 ..mu..Sv a/sup -1/) and to gamma radiation (ca. 30 ..mu..Sv a/sup -1/). The enhancement of dose rates over the ponds and of radioactivity concentration of liquid discharges from the ponds was found to be negligible. Dose rates in houses built entirely of fly ash were estimated to be higher than those in red-brick houses by not more than 0.2 ..mu..Sv a/sup -1/. The collective EDEC from the operational discharge of the steelworks is less than 11 man Sv a/sup -1/ and that of use of fly-ash prefabricated elements will be in the future less than 45 man Sv a/sup -1/.

  15. Relaxation of Si-SiO2 interfacial stress in bipolar screen oxides due to ionizing radiation

    Witczak, S.C.; Galloway, K.F.; Schrimpf, R.D.; Suehle, J.S.

    1995-01-01

    Current gain degradation due to ionizing radiation in complementary single-crystalline emitter bipolar transistors was found to grow progressively worse upon subjecting the transistors to repeated cycles of radiation exposure and high-temperature anneal. The increase in radiation sensitivity is independent of the emitter polarity or geometry and is most dramatic between the first and second radiation and anneal cycles. In parallel with the current gain measurements, samples from a monitor wafer simulating the screen oxide region above the extrinsic base in the npn transistors were measured for mechanical stress while undergoing similar cycles of irradiation and anneal. The oxide on the monitor wafer consisted of a 45 nm thermal layer and a 640 nm deposited layer. The results indicate that ionizing radiation helped relieve compressive stress at the Si surface. The magnitude of the stress change due to radiation is smaller than the stress induced by the emitter contact metallization followed by a post-metallization anneal. Correlation of radiation sensitivity in the bipolar transistors and mechanical stress in the monitor wafer suggests that mechanical stress may be influential in determining the radiation hardness of bipolar transistors and lends validation to previously reported observations that Si-SiO 2 interfaces are increasingly more susceptible to radiation damage with decreasing Si compressive stress. Possible mechanisms for the observed changes in stress and their effect on the radiation sensitivity of the bipolar transistors are discussed

  16. A methodology to establish the appearance of cancer cases due to radiation dose in compressed breast

    Feital, Joao Carlos Da Silva; Delgado, Jose Ubiratan; Peixoto, Jose Guilherme P.; Fonseca, Hugo Geraldo Da

    2013-01-01

    It is known that more than 20% of the world's population will contract some type of cancer. In Brazil, with the exception of skin cancer (non melanoma) the breast cancer ranks first among the higher frequency of tumours among women and in general, although the methods of detection are advancing in the year 2010 took place about 13 thousand deaths in about 50,000 cases, probably due to late detection of these neoplasm. New cases of breast cancer in a given population can be proven from absorbed dose quantity, calculated for the compressed breast, due to the risk by means of exposure to x rays in this radiodiagnostic practices. Methodology: Exposures were held in an ionization chamber and the other quantities required were obtained to the screen-film equipment of mammography. Results: Also experimental results were of compressed breast an equivalent dose of ( 1.82 mSv ± 0.2%) or (3.64 mSv ± 0.2%) for both projections, i.e. medium lateral oblique and cranio caudal. The experimental value obtained here is consistent with the calculated results and published in the literature for analog and CR equipment. Conclusion: From the result of dose equivalent in the breast, one can say that there will be effectively attesting as to the appearance of new cases of cancer if approximately 80 million women are exposed to radiation emitted by mammographers. (author)

  17. Dust grain dynamics due to nonuniform and nonstationary high-frequency radiations in cold magnetoplasmas

    A. K. Nekrasov

    2006-03-01

    Full Text Available A general nonlinear theory for low-frequency electromagnetic field generation due to high-frequency nonuniform and nonstationary electromagnetic radiations in cold, uniform, multicomponent, dusty magnetoplasmas is developed. This theory permits us to consider the nonlinear action of all waves that can exist in such plasmas. The equations are derived for the dust grain velocities in the low-frequency nonlinear electric fields arising due to the presence of electromagnetic cyclotron waves travelling along the background magnetic field. The dust grains are considered to be magnetized as well as unmagnetized. Different regimes for the dust particle dynamics, depending on the spatio-temporal change of the wave amplitudes and plasma parameters, are discussed. It is shown that induced nonlinear electric fields can have both an electrostatic and electromagnetic nature. Conditions for maximum dust acceleration are found. The results obtained may be useful for understanding the possible mechanisms of dust grain dynamics in astrophysical, cosmic and laboratory plasmas under the action of nonuniform and nonstationary electromagnetic waves.

  18. Long-term follow-up observation of patients with chronic radiation sickness due to external irradiation treated with thymopeptide

    Gao Shenyong; Sun Wenji; Zhang Aizhen; Ye Anfang

    1998-01-01

    Objective: To provide the clinical data and prognosis judgement, the authors observed the results and progression of 11 cases of chronic radiation sickness due to external irradiation treated with thymopeptide. Methods: The clinical symptoms, hematopoiesis, T lymphocyte percentage and chromosome aberration rate were used as the judgement indexes for recovery from the chronic radiation sickness. Results: Thymopeptide treatment greatly improved the neurasthenic syndrome and increased the T lymphocyte percentage (P 0.05), and improvement of neurasthenic syndrome occurred 3.5 years after they left radiation work or diminished the exposure level. 5 to 8 years after, bone marrow hematopoiesis also restored to the normal level. However, the chromosome aberration rate restored to the normal level 10 years after. Conclusion: According to the judgement criteria, the chronic radiation sickness due to external radiation exposure can recover and thymopeptide is a helpful and simple means to treat it

  19. Constraining the cosmic radiation density due to lepton number with Big Bang Nucleosynthesis

    Mangano, Gianpiero; Miele, Gennaro; Pisanti, Ofelia; Sarikas, Srdjan; Pastor, Sergio

    2011-01-01

    The cosmic energy density in the form of radiation before and during Big Bang Nucleosynthesis (BBN) is typically parameterized in terms of the effective number of neutrinos N eff . This quantity, in case of no extra degrees of freedom, depends upon the chemical potential and the temperature characterizing the three active neutrino distributions, as well as by their possible non-thermal features. In the present analysis we determine the upper bounds that BBN places on N eff from primordial neutrino-antineutrino asymmetries, with a careful treatment of the dynamics of neutrino oscillations. We consider quite a wide range for the total lepton number in the neutrino sector, η ν = η ν e +η ν μ +η ν τ and the initial electron neutrino asymmetry η ν e in , solving the corresponding kinetic equations which rule the dynamics of neutrino (antineutrino) distributions in phase space due to collisions, pair processes and flavor oscillations. New bounds on both the total lepton number in the neutrino sector and the ν e −ν-bar e asymmetry at the onset of BBN are obtained fully exploiting the time evolution of neutrino distributions, as well as the most recent determinations of primordial 2 H/H density ratio and 4 He mass fraction. Note that taking the baryon fraction as measured by WMAP, the 2 H/H abundance plays a relevant role in constraining the allowed regions in the η ν −η ν e in plane. These bounds fix the maximum contribution of neutrinos with primordial asymmetries to N eff as a function of the mixing parameter θ 13 , and point out the upper bound N eff ∼ eff by the Planck satellite will likely provide insight on the nature of the radiation content of the universe

  20. Constraining the cosmic radiation density due to lepton number with Big Bang Nucleosynthesis

    Mangano, Gianpiero; Miele, Gennaro; Pastor, Sergio; Pisanti, Ofelia; Sarikas, Srdjan

    2011-03-01

    The cosmic energy density in the form of radiation before and during Big Bang Nucleosynthesis (BBN) is typically parameterized in terms of the effective number of neutrinos Neff. This quantity, in case of no extra degrees of freedom, depends upon the chemical potential and the temperature characterizing the three active neutrino distributions, as well as by their possible non-thermal features. In the present analysis we determine the upper bounds that BBN places on Neff from primordial neutrino-antineutrino asymmetries, with a careful treatment of the dynamics of neutrino oscillations. We consider quite a wide range for the total lepton number in the neutrino sector, ην = ηνe+ηνμ+ηντ and the initial electron neutrino asymmetry ηνein, solving the corresponding kinetic equations which rule the dynamics of neutrino (antineutrino) distributions in phase space due to collisions, pair processes and flavor oscillations. New bounds on both the total lepton number in the neutrino sector and the νe-bar nue asymmetry at the onset of BBN are obtained fully exploiting the time evolution of neutrino distributions, as well as the most recent determinations of primordial 2H/H density ratio and 4He mass fraction. Note that taking the baryon fraction as measured by WMAP, the 2H/H abundance plays a relevant role in constraining the allowed regions in the ην-ηνein plane. These bounds fix the maximum contribution of neutrinos with primordial asymmetries to Neff as a function of the mixing parameter θ13, and point out the upper bound Nefflesssim3.4. Comparing these results with the forthcoming measurement of Neff by the Planck satellite will likely provide insight on the nature of the radiation content of the universe.

  1. Surface erosion of fusion reactor components due to radiation blistering and neutron sputtering

    Das, S.K.; Kaminsky, M.

    1975-01-01

    Radiation blistering and neutron sputtering can lead to the surface erosion of fusion reactor components exposed to plasma radiations. Recent studies of methods to reduce the surface erosion caused by these processes are discussed

  2. Comparison of horizontal and vertical noise power spectrum in measurements by using various electronic portal imaging devices in radiation therapy

    Kim, Ki Won [Dept. of Radiology, Kyung Hee University Hospital at Gang-dong, Seoul (Korea, Republic of); Choi, Kwan Woo [Dept. of Radiology, Asan Medical Center, Seoul (Korea, Republic of); Jeong, Hoi Woun [Dept. of Radiological Technology, Baekseok Culture University, Cheonan (Korea, Republic of); Jang, Seo Goo [Dept. of Medical Science, Soonchunhyang University, Asan (Korea, Republic of); Kwon, Kyung Tae [Dept. of Radiological Technology, Dongnam Health University, Suwon (Korea, Republic of); Son, Soon Yong [Dept. of Radiological Technology, Wonkwang Health Science University, Iksan (Korea, Republic of); Son, Jin Hyun; Min, Jung Whan [Dept. of Radiological Technology, Shingu University, Sungnam (Korea, Republic of)

    2016-06-15

    The quality assurance (QA) is very important for diagnostic field and radiation therapy field to evaluate the characteristic of devices. The purpose of this study was to compare different NPS methodologies results which are measuring NPS with regard to horizontal and vertical directions by using megavoltage X-ray energies. The NPS evaluation methods were applied to the International Electro-technical Commission standard (IEC 62220-1). The electronic portal imaging devices (EPID) devices such as Siemens BEAMVIEWPLUS, Elekta iViewGT and Varian ClinacR iX aS1000 were used. NPS data were expressed by corresponding each frequency about average of noise value corresponding the each frequency, and NPS were evaluated quantitatively by totaling up the noise values of average frequency which are on horizontal and vertical directions. In NPS results for Elekta iViewGT, NPS of horizontal and vertical by using 4 methods were indicated the difference of 3-5% between horizontal and vertical direction. In the results of Siemens BEAMVIEWPLUS and Varian ClinacR iX aS1000, the NPS of horizontal and vertical direction were indicated the difference of 15% when averaging the whole values. This study were evaluated the NPS of each devices by totaling up the noise values of average frequency which are on horizontal and vertical directions suggesting the quantitative evaluation method using the data.

  3. A Study of Direct and Cloud-Mediated Radiative Forcing of Climate Due to Aerosols

    Yu, Shao-Cai

    1999-01-01

    The Intergovernmental Panel on Climate Change (IPCC) has reported that in the southeastern US and eastern China, the general greenhouse warming due to anthropogenic gaseous emissions is dominated by the cooling effect of anthropogenic aerosols. To verify this model prediction in eastern China and southeastern US, we analyzed regional patterns of climate changes at 72 stations in eastern China during 1951- 94 (44 years), and at 52 stations in the southeastern US during 1949-94 (46 years) to detect the fingerprint of aerosol radiative forcing. It was found that the mean rates of change of annual mean daily, maximum, minimum temperatures and diurnal temperature range (DTR) in eastern China were 0.8, -0.2, 1.8, and -2.0 C/100 years respectively, while the mean rates of change of annual mean daily, maximum, minimum temperatures and DTR in the southeastern US were -0.2, -0.6, 0.2, and -0.8 C/100 years, respectively. This indicates that the high rate of increase in annual mean minimum temperature in eastern China results in a slightly warming trend of daily temperature, while the high rate of decrease in annual mean maximum temperature and low rate of increase in annual mean minimum temperature lead to the cooling trend of daily temperature in the southeastern US. We found that the warming from the longwave forcing due to both greenhouse gases and aerosols was completely counteracted by the shortwave aerosol forcing in the southeastern US in the past 46 years. A slightly overall warming trend in eastern China is evident; winters have become milder. This finding is explained by hypothesizing that increasing energy usage during the past 44 years has resulted in more coal and biomass burning, thus increasing the emission of absorbing soot and organic aerosols in eastern China. Such emissions, in addition to well-known Asia dust and greenhouse gases, may be responsible for the winter warming trend in eastern China that we have reported here. The sensitivity of aerosol

  4. A modeling study of effective radiative forcing and climate response due to increased methane concentration

    Bing Xie

    2016-12-01

    Full Text Available An atmospheric general circulation model BCC_AGCM2.0 and observation data from ARIS were used to calculate the effective radiative forcing (ERF due to increased methane concentration since pre-industrial times and its impacts on climate. The ERF of methane from 1750 to 2011 was 0.46 W m−2 by taking it as a well-mixed greenhouse gas, and the inhomogeneity of methane increased its ERF by about 0.02 W m−2. The change of methane concentration since pre-industrial led to an increase of 0.31 °C in global mean surface air temperature and 0.02 mm d−1 in global mean precipitation. The warming was prominent over the middle and high latitudes of the Northern Hemisphere (with a maximum increase exceeding 1.4 °C. The precipitation notably increased (maximum increase of 1.8 mm d−1 over the ocean between 10°N and 20°N and significantly decreased (maximum decrease >–0.6 mm d−1 between 10°S and 10°N. These changes caused a northward movement of precipitation cell in the Intertropical Convergence Zone (ITCZ. Cloud cover significantly increased (by approximately 4% in the high latitudes in both hemispheres, and sharply decreased (by approximately 3% in tropical areas.

  5. Radiation doses due to long-range transport of airborne radionuclides

    Nordlund, G.; Valkama, I.; Rossi, J.; Savolainen, I.

    1985-12-01

    Within the framework of this study a model for estimating the long range transport of radioactive material and for calculating the resultant doses is developed. In the model initially the dispersion paths, i.e. trajectories, of the radioactive matter are calculated from the assumed source areas as well as the dispersion conditions along the trajectories. The trajectories are calculated at three-hour intervals in a two-dimensional grid using numerically analysed winds at a constant pressure level of 850 mb. The dispersion condition parameters applied are: the stability of the atmospheric boundary layer, the so-called mixing height, occurrence of precipitation and the character of the terrain. For each trajectory a type-index value is computed, describing the severity of the possible effects of radioactivity transported by the particular trajectory. The dispersion model uses the information on dispersion conditions provided by the trajectory model to compute the remaining radioactivity in the cloud, the deposition, as well as the doses due to different dose pathways. The pathways used are the external radiation from the cloud and from the activity deposited on the ground, inhalation of radioactive material and ingestion of contaminated food products (milk, meat, green vegetables, grain and roots). In addition to the effects of individual transport incidents, the cumulative probability distributions of the effects of accidental releases of radioactive matter can also be calculated using trajectory statistics and the trajectory type index

  6. Radiation annealing in Ag and Au due to energetic displacement cascades

    Averback, R.S.; Merkle, K.L.

    1975-01-01

    Radiation annealing due to energetic displacement cascades has been studied in Ag and Au. Thin film specimens, 2500 A, were doped to various concentrations of Frenkel pair defects by irradiating with 150 keV protons at temperatures below 10 K. Subsequently, the specimens were irradiated below 10 K with energetic, approximately 540 keV, self-ions. Electrical resistivity measurements were used to monitor the concentration of defects as a function of dose. In Au, approximately 5 percent of the doped-in Frenkel pairs, annealed during the 540 keV Au irradiation. The annealing volume associated with individual cascades was found to be 2.1 x 10 -16 cm 3 . In Ag approximately 5 percent of the doped-in defects annealed during a 500 keV Ag irradiation and the annealing volume of the cascade was found to be 5 x 10 -16 cm 3 . In addition, the effects of doping concentration and specimen temperature during doping were investigated

  7. Aspects of radiation effects due to visual display units at work

    Vana, N.

    1988-01-01

    The introduction and acceptance of video display units at work have led to a huge flood of information, rumours, and half-truths about those units. As the population became increasingly sensitized to 'radioactive radiation', there was, and in part still is, a tendency to consider particularly effects of unclear origin, first of all ionizing radiation and later on also non-ionizing radiation, as the main threat from video display units at work. Such important issuses as ergonomics, stress load, visual stress load, and social hygiene are often effaced by the question for 'the radiation load from visual display units'. The paper is an attempt to deal with aspects of radiation effects of visual display units at work. The discussion also extends to hazards, respectively the 'radiation environment', at the site of the visual display unit. (orig./DG) [de

  8. Sensitivity of APSIM/ORYZA model due to estimation errors in solar radiation

    Alexandre Bryan Heinemann

    2012-01-01

    Full Text Available Crop models are ideally suited to quantify existing climatic risks. However, they require historic climate data as input. While daily temperature and rainfall data are often available, the lack of observed solar radiation (Rs data severely limits site-specific crop modelling. The objective of this study was to estimate Rs based on air temperature solar radiation models and to quantify the propagation of errors in simulated radiation on several APSIM/ORYZA crop model seasonal outputs, yield, biomass, leaf area (LAI and total accumulated solar radiation (SRA during the crop cycle. The accuracy of the 5 models for estimated daily solar radiation was similar, and it was not substantially different among sites. For water limited environments (no irrigation, crop model outputs yield, biomass and LAI was not sensitive for the uncertainties in radiation models studied here.

  9. Potential health risks due to telecommunications radiofrequency radiation exposures in Lagos State Nigeria.

    Aweda, M A; Ajekigbe, A T; Ibitoye, A Z; Evwhierhurhoma, B O; Eletu, O B

    2009-01-01

    The global system mobile telecommunications system (GSM) which was recently introduced in Nigeria is now being used by over 40 million people in Nigeria. The use of GSM is accompanied with exposure of the users to radiofrequency radiation (RFR), which if significant, may produce health hazards. This is the reason why many relevant national and international organizations recommended exposure limits to RFR and why it is made compulsory for GSM handsets to indicate the maximum power output as a guide to potential consumers. This study was conducted to measure the RFR output power densities (S) from the most commonly used GSM handsets used in Lagos State and compare with the limit recommended for safety assessment. Over 1100 most commonly used handsets of different makes and models as well as wireless phones were sampled and studied in all over the local government areas of the State. An RFR meter, Electrosmog from LESSEMF USA was used for the measurements. The handsets were assessed for health risks using the reference value of 9 Wm(-2) as recommended by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). The range of the S-values obtained varied from a minimum of 1.294 0.101 Wm(-2) with Siemens model R228 to a maximum of 16.813 +/- 0.094 Wm(-2) with Samsung model C140*. The results from wireless telephones showed very low S-values ranging from a minimum of 0.024 +/- 0.001 Wm(-2) with HUAWEI and ST CDMA 1 to a maximum of 0.093 +/- 0.002 Wm(-2) with HISENSE. The results showed that the population in Lagos State may be at risk due to significant RFR exposures resulting principally from the use of GSM. Quite a number of handsets emit power above the ICNIRP recommended value. Measured RFR power close to Radio and Television masts and transmitters are within tolerable limits in most cases, only that the public should not reside or work close to RFR installations. Phone calls with GSM should be restricted to essential ones while youths and children

  10. Constraining the cosmic radiation density due to lepton number with Big Bang Nucleosynthesis

    Mangano, Gianpiero; Miele, Gennaro; Pisanti, Ofelia; Sarikas, Srdjan [Istituto Nazionale di Fisica Nucleare – Sezione di Napoli, Complesso Universitario di Monte S. Angelo, I-80126 Napoli (Italy); Pastor, Sergio, E-mail: mangano@na.infn.it, E-mail: miele@na.infn.it, E-mail: pastor@ific.uv.es, E-mail: pisanti@na.infn.it, E-mail: sarikas@na.infn.it [Instituto de Física Corpuscular (CSIC-Universitat de València), Ed. Institutos de Investigación, Apdo. correos 22085, E-46071 Valencia (Spain)

    2011-03-01

    The cosmic energy density in the form of radiation before and during Big Bang Nucleosynthesis (BBN) is typically parameterized in terms of the effective number of neutrinos N{sub eff}. This quantity, in case of no extra degrees of freedom, depends upon the chemical potential and the temperature characterizing the three active neutrino distributions, as well as by their possible non-thermal features. In the present analysis we determine the upper bounds that BBN places on N{sub eff} from primordial neutrino-antineutrino asymmetries, with a careful treatment of the dynamics of neutrino oscillations. We consider quite a wide range for the total lepton number in the neutrino sector, η{sub ν} = η{sub ν{sub e}}+η{sub ν{sub μ}}+η{sub ν{sub τ}} and the initial electron neutrino asymmetry η{sub ν{sub e}{sup in}}, solving the corresponding kinetic equations which rule the dynamics of neutrino (antineutrino) distributions in phase space due to collisions, pair processes and flavor oscillations. New bounds on both the total lepton number in the neutrino sector and the ν{sub e}−ν-bar {sub e} asymmetry at the onset of BBN are obtained fully exploiting the time evolution of neutrino distributions, as well as the most recent determinations of primordial {sup 2}H/H density ratio and {sup 4}He mass fraction. Note that taking the baryon fraction as measured by WMAP, the {sup 2}H/H abundance plays a relevant role in constraining the allowed regions in the η{sub ν}−η{sub ν{sub e}{sup in}} plane. These bounds fix the maximum contribution of neutrinos with primordial asymmetries to N{sub eff} as a function of the mixing parameter θ{sub 13}, and point out the upper bound N{sub eff}∼<3.4. Comparing these results with the forthcoming measurement of N{sub eff} by the Planck satellite will likely provide insight on the nature of the radiation content of the universe.

  11. Sensitivity of APSIM/ORYZA model due to estimation errors in solar radiation

    Alexandre Bryan Heinemann; Pepijn A.J. van Oort; Diogo Simões Fernandes; Aline de Holanda Nunes Maia

    2012-01-01

    Crop models are ideally suited to quantify existing climatic risks. However, they require historic climate data as input. While daily temperature and rainfall data are often available, the lack of observed solar radiation (Rs) data severely limits site-specific crop modelling. The objective of this study was to estimate Rs based on air temperature solar radiation models and to quantify the propagation of errors in simulated radiation on several APSIM/ORYZA crop model seasonal outputs, yield, ...

  12. Measurement and Analysis of the Noise Radiated by Low Mach Numbers Centrifugal Blowers

    1987-11-01

    Lang, V Manager of the IBM Poughkeepsie Acoustics Laboratory, for his understanding and support. I would also like to express my gratitude to the IBM...ficl.l. Knowlede p of these quantities provides important information on the relative strength of thL :cro- a dynamic noise sources on the blade... manageability . The model blower design was thus determined by scaling all of the linear dimensions of the reference device by 2.0 and by maintaining • all of

  13. Aspect-dependent radiated noise analysis of an underway autonomous underwater vehicle.

    Gebbie, John; Siderius, Martin; Allen, John S

    2012-11-01

    This paper presents an analysis of the acoustic emissions emitted by an underway REMUS-100 autonomous underwater vehicle (AUV) that were obtained near Honolulu Harbor, HI using a fixed, bottom-mounted horizontal line array (HLA). Spectral analysis, beamforming, and cross-correlation facilitate identification of independent sources of noise originating from the AUV. Fusion of navigational records from the AUV with acoustic data from the HLA allows for an aspect-dependent presentation of calculated source levels of the strongest propulsion tone.

  14. Reducing radiation dose in liver enhanced CT scan by setting mAs according to plain scan noise

    Yang Shangwen; He Jian; Yang Xianfeng; Zhou Kefeng; Xin Xiaoyan; Hu Anning; Zhu Bin

    2013-01-01

    Objective: To investigate the feasibility of setting mAs in liver enhanced CT scan according to plain scan noise with fixed mA CT scanner, in order to reduce the radiation dose. Methods: One hundred continuous patients underwent liver enhanced CT scan (group A) prospectively. Two hundred and fifty mAs was used in plain and enhanced CT scans. Noises of plain and venous phase CT images were measured, and the image quality was evaluated. The equation between mAs of enhanced scan and noise of plain scan image was derived. Another 100 continuous patients underwent liver enhanced CT scan (group B). Enhanced scan mAs was calculated from noise on plain scan by using the equation above. Noises on venous phase images were measured and the image quality was measured. Based on body mass index (BMI), patients in groups A and B were divided into three subgroups respectively: BMI < 18.5 kg/m 2 , 18.5 kg/m 2 ≤ BMI < 25.0 kg/m 2 and BMI ≥ 25.0 kg/m 2 . Image quality score was compared with nonparametric rank sum test, CT dose index (CTDI) and effective dose (ED) were measured and compared between each subgroup with 2 independent samples t or t' test. Results: The equation between enhanced scan mAs (mAsX) and plain scan noise (SDp) was as follows: mAsX = mAs1 × [(0.989 × SDp + 1.06) /SDx] 2 , mAs1 = 250 mAs, SDx = 13. In patients with BMI < 18.5 kg/m 2 , ED of group A [(6.86 ± 0.38) mSv, n = 12] was significantly higher than group B [(2.66 ± 0.46) mSv, n = 10)] (t = 18.52, P < 0.01). In patients with 18.5 kg/m 2 ≤ BMI < 25.0 kg/m 2 , ED of group A [(7.08 ± 0.91) mSv, n = 66] was significantly higher than group B [(4.50 ± 1.41) mSv, n = 73] (t' = 10.57, P < 0.01). In patients with BMI ≥ 25.0 kg/m 2 , there was no significant difference between EDs of group A (7.54 ± 0.62 mSv, n = 22) and group B [(8.19 ± 3.16) mSv, n = 17] (t' = 0.89, P = 0.39). Image quality of 5 patients in group A and none in group B did not meet the diagnostic requirement

  15. Potential exposure to natural radiation inside dwellings, due to phosphogypsum use in the building industry

    Rosa, Roosevelt

    1997-01-01

    The interest of building industry to improve the standardization of building processes result in a increasing tendency of using the gypsum as boards, and as a projected gypsum mortars. On the other hand, the need of reuse industrial wastes to avoid environmental impact resulting of their deposition and to reduce the management costs, indicates the building industry as an important user of large quantities of industrial wastes, mainly that generated in the ore milling The industry of phosphate fertilizers is a typical example of this interaction. The phosphate rock milling through the wet process, reacting phosphate rock with sulfuric acid, produces substantial quantities of calcium sulfate as a by-product known as phosphogypsum, that are stored in stockpiles. The phosphate rock contains radionuclides of the U and Th decay series. During the chemical attack these radionuclides are distributed in different proportions between the phosphoric acid and the phosphogypsum. This work presents the radiological characterization phosphogypsum, produced by two national fertilizers industries. A methodology to quantify the radiation exposure, in a reference dwelling , due the use of phosphogypsum considering different scenarios, was established. The external irradiation and the inhalation of radon and thoron and their decay products in indoor air were considered. The values of individual effective dose equivalent ranged from 0.12 to 1.95 mSv.a 1 , depending on the phosphogypsum origin and the scenario considered. About 80% of the dose rises from the inhalation of thoron and its decay products. The results show the importance of Th series radioactive disequilibrium in the assessment. Depending on the phosphogypsum origin and scenario of use, the dose values justify the control of this practice. The general conclusion is that this practice have to be considered case by case and the proposed methodology is suitable to assess the dose and the radioactive disequilibrium consequences

  16. Correction method of nonlinearity due to logarithm operation for X-ray CT projection data with noise in photon-starved state

    Iwamoto, Shin-ichiro; Shiozaki, Akira

    2007-01-01

    In the acquisition of projection data of X-ray CT, logarithm operation is indispensable. But noise distribution is nonlinearly projected by the logarithm operation, and this deteriorates the precision of CT number. This influence becomes particularly remarkable when only a few photons are caught with a detector. It generates a strong streak artifact (SA) in a reconstructed image. Previously we have clarified the influence of the nonlinearity by statistical analysis and proposed a correction method for such nonlinearity. However, there is a problem that the compensation for clamp processing cannot be performed and that the suppression of SA is not enough in photon shortage state. In this paper, we propose a new technique for correcting the nonlinearity due to logarithm operation for noisy data by combining the previously presented method and an adaptive filtering method. The technique performs an adaptive filtering only when the number of captured photons is very few. Moreover we quantitatively evaluate the influence of noise on the reconstructed image in the proposed method by the experiment using numerical phantoms. The experimental results show that there is less influence on spatial resolution despite suppressing SA effectively and that CT number are hardly dependent on the number of the incident photons. (author)

  17. Simultaneos determination of absorbed doses due to beta and gamma radiations with CaSO4: Dy produced at Ipen

    Campos, L.L.; Rosa, L.A.R. da.

    1988-07-01

    Due to the Goiania radiological accident, it was necessary to develop urgently a dosimeter in order to evaluate, simultaneously, beta and gamma absorbed doses, due to 137 Cs radiations. Therefore, the Dosimetric Material Production Laboratory of IPEN developed a simple, practical, light and low cost badge using small thickness (0,20mm) thermoluminescent CaSO 4 : Dy pellets produced by the same laboratory. This pellets are adequate for beta radiation detection. These dosimeters were worn by some IPEN technicians who worked in Goiania city, and were used to evaluate the external and internal contaminations presented by the accident victims interned at the Hospital Naval Marcilio Dias. (author) [pt

  18. The efficacy of sucralfate suspension in the prevention of oral mucositis due to radiation therapy

    Epstein, J.B.; Wong, F.L.W.

    1994-01-01

    The purpose of this study was to assess the value of sucralfate suspension in prevention of oral mucositis and for reduction of oral pain in patients who develop mucositis during radiation therapy. The study was a double-blind, placebo-controlled, randomized prospective trial of a sucralfate suspension in the prevention and management of oral mucositis during radiation therapy. Oral mucositis was assessed using a quantitative scale and symptoms were assessed using visual analogue scales. The statistical model was developed to detect a 40% reduction in mucositis. No statistically significant reduction in mucositis was seen. Early during radiation therapy less oral pain was reported in the sucralfate group, but as treatment progressed all patients experienced pain. Patients in the sucralfate group were prescribed topical and systemic analgesics later in the course of radiation therapy. Prophylactic oral rinsing with sucralfate did not prevent oral ulcerative mucositis. Sucralfate may reduce the experience of pain during radiation therapy. 32 refs., 3 tabs

  19. The efficacy of sucralfate suspension in the prevention of oral mucositis due to radiation therapy

    Epstein, J.B.; Wong, F.L.W. (British Columbia Cancer Agency, Vancouver (Canada))

    1994-02-01

    The purpose of this study was to assess the value of sucralfate suspension in prevention of oral mucositis and for reduction of oral pain in patients who develop mucositis during radiation therapy. The study was a double-blind, placebo-controlled, randomized prospective trial of a sucralfate suspension in the prevention and management of oral mucositis during radiation therapy. Oral mucositis was assessed using a quantitative scale and symptoms were assessed using visual analogue scales. The statistical model was developed to detect a 40% reduction in mucositis. No statistically significant reduction in mucositis was seen. Early during radiation therapy less oral pain was reported in the sucralfate group, but as treatment progressed all patients experienced pain. Patients in the sucralfate group were prescribed topical and systemic analgesics later in the course of radiation therapy. Prophylactic oral rinsing with sucralfate did not prevent oral ulcerative mucositis. Sucralfate may reduce the experience of pain during radiation therapy. 32 refs., 3 tabs.

  20. Monitoring and assessment of individual doses of occupationally exposed workers due to external radiation

    Kitaw, S. T.

    2015-05-01

    Exposure to external radiation occurs in many occupations. Any exposure to ionizing radiation has the tendency to change the biochemical make-up of the human body which may result in biological health effects of ionizing radiation. This study reviews the monitoring and assessment of external radiation doses in industrial radiography using thermoluminescence and direct reading dosimeters. Poor handling procedures such as inadequate engineering control of equipment, safety culture, management, and inadequate assessment and monitoring of doses are the causes of most of the reported cases of exposure to external radiation in industrial radiography. Occupational exposure data in industrial radiography from UNSCEAR report 2008 was discussed and recommendations were made to regulatory authorities, operating organizations and radiographers. (au)

  1. SCC, Bowen's disease and BCC arising on chronic radiation dermatitis due to radiation therapy for tinea pedis

    Aoki, Eri; Aoki, Mikako; Ikemura, Akiko; Igarashi, Tsukasa; Suzuki, Kayano; Kawana, Seiji

    2000-01-01

    We reported a case who developed three different types of skin cancers: SCC, BCC, and Bowen's disease, on the chronic radiation dermatitis. He had been treated for his tinea pedis et palmaris with radiotherapy in 1940's. It is very ratre that three different types of skin cancers arise in the same patient. This is a second case reported in Japan. (author)

  2. Comparative Study on Radiological Impact Due To Direct Exposure to a Radiological Dispersal Device Using A Sealed Radiation Source

    Margeanu, C.A.

    2011-01-01

    Nowadays, one of the most serious terrorist threats implies radiological dispersal devices (RDDs), the so-called dirty bombs, that combine a conventional explosive surrounded by an inflammatory material (like thermit) with radioactive material. The paper objective is to evaluate the radiological impact due to direct exposure to a RDD using a sealed radiation source (used for medical and industrial applications) as radioactive material. The simulations were performed for 60Co, 137Cs and 192Ir radiation sources. In order to model the contamination potential level and radiation exposure due to radioactive material spreading from RDD, Lawrence Livermore National Laboratory's HOTSPOT 2.07 computer code was used. The worst case scenario has been considered, calculations being performed for two radioactive material dispersion models, namely General radioactive Plume and General Explosion. Following parameters evolution with distance from the radiation source was investigated: total effective dose equivalent, time-integrated air concentration, ground surface deposition and ground shine dose rates. Comparisons between considered radiation sources and radioactive material dispersion models have been performed. The most drastic effects on population and the environment characterize 60Co sealed radiation source use in RDD.

  3. Emittance growth due to static and radiative space charge forces in an electron bunch compressor

    Talman, Richard; Malitsky, Nikolay; Stulle, Frank

    2009-01-01

    -21, MOCOS05, available at http://www.JACoW.org], a code with similar capabilities. For this comparison an appropriately new, 50 MeV, “standard chicane” is introduced. Unlike CSRTrack (which neglects vertical forces) the present simulation shows substantial growth of vertical emittance. But “turning off” vertical forces in the UAL code (to match the CSRTrack treatment) brings the two codes into excellent agreement. (iii) Results are also obtained for 5 GeV electrons passing through a previously introduced “standard chicane” [Coherent Synchrotron Radiation, CSR Workshop, Berlin 2002, http://www.desy.de/csr] [of the sort needed for linear colliders and free electron lasers (FEL’s) currently under design or construction]. Relatively little emittance growth is predicted for typical bunch parameters at such high electron energy. Results are obtained for both round beams and ribbon beams (like those actually needed in practice). Little or no excess emittance growth is found for ribbon bunches compared to round bunches of the same charge and bunch width. The UAL string space charge formulation (like TraFic4 and CSRTrack) avoids the regularization step (subtracting the free-space space charge force) which is required (to remove divergence) in some methods. Also, by avoiding the need to calculate a retarded-time, four-dimensional field history, the computation time needed for realistic bunch evolution calculations is modest. Some theories of bunch dilution, because they ascribe emittance growth entirely to CSR, break down at low energy. In the present treatment, as well as CSR, all free-space Coulomb and magnetic space charge forces (but not image forces), and also the centrifugal space charge force (CSCF) are included. Charge-dependent beam steering due to CSCF, as observed recently by Beutner et al. [B. Beutner , in Proceedings of FEL Conference, BESSY, Berlin, Germany, 2006, MOPPH009], is also investigated.

  4. Electromagnetic noise inhibits radiofrequency radiation-induced DNA damage and reactive oxygen species increase in human lens epithelial cells

    Wu, Wei; Wang, KaiJun; Ni, Shuang; Ye, PanPan; Yu, YiBo; Ye, Juan; Sun, LiXia

    2008-01-01

    Purpose The goal of this study was to investigate whether superposing of electromagnetic noise could block or attenuate DNA damage and intracellular reactive oxygen species (ROS) increase of cultured human lens epithelial cells (HLECs) induced by acute exposure to 1.8 GHz radiofrequency field (RF) of the Global System for Mobile Communications (GSM). Methods An sXc-1800 RF exposure system was used to produce a GSM signal at 1.8 GHz (217 Hz amplitude-modulated) with the specific absorption rate (SAR) of 1, 2, 3, and 4 W/kg. After 2 h of intermittent exposure, the ROS level was assessed by the fluorescent probe, 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA). DNA damage to HLECs was examined by alkaline comet assay and the phosphorylated form of histone variant H2AX (γH2AX) foci formation assay. Results After exposure to 1.8 GHz RF for 2 h, HLECs exhibited significant intracellular ROS increase in the 2, 3, and 4 W/kg groups. RF radiation at the SAR of 3 W/kg and 4 W/kg could induce significant DNA damage, examined by alkaline comet assay, which was used to detect mainly single strand breaks (SSBs), while no statistical difference in double strand breaks (DSBs), evaluated by γH2AX foci, was found between RF exposure (SAR: 3 and 4 W/kg) and sham exposure groups. When RF was superposed with 2 μT electromagnetic noise could block RF-induced ROS increase and DNA damage. Conclusions DNA damage induced by 1.8 GHz radiofrequency field for 2 h, which was mainly SSBs, may be associated with the increased ROS production. Electromagnetic noise could block RF-induced ROS formation and DNA damage. PMID:18509546

  5. The regulations for enforcing the law concerning prevention from radiation hazards due to radioisotopes

    1977-01-01

    Those who want to use, sell or dispose of radioactive isotopes as occupation should file applications for approval attached with the required documents. Those who want to change the approved items of use, sale or disposal of radioactive isotopes should file applications for approval. The number of documents for the application of approval are one original and four duplicates. The use, refilling, storage, transportation and disposal of radioactive isotopes should be carried out in accordance with the specified standards, respectively. Radiation dose rate, density of particle fluxes, and the state of contamination caused by radioactive isotopes should be measured in the specified places at the specified frequency, and the records of such measurements should be kept. Prevention of radiation injuries including the measures for finding those who suffer from radiation injuries and the measures for those who underwent or might undergo radiation injuries should be carried out in accordance with the respective specifications. (Rikitake, Y.)

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

    Dekoulis, George

    2009-05-01

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

  7. Repair of radiation damage of Micrococcus radioproteolyticus due to gamma and UV irradiation

    Ryznar, L.; Drasil, V.

    1982-01-01

    Cells were irradiated in dry state with gamma radiation and UV radiation. The post-irradiation warming of freeze dried cells (2 hours to 60deg or to 80deg) influenced the ability to repair sublethal damage. Heating to 80deg caused a mild reduction in survival. The repair of irradiated and heated cells required more time than that of cells which had only been irradiated. (M.D.)

  8. Explanation for Cancer in Rats, Mice and Humans due to Cell Phone Radiofrequency Radiation

    Feldman, Bernard J.

    2016-01-01

    Very recently, the National Toxicology Program reported a correlation between exposure to whole body 900 MHz radiofrequency radiation and cancer in the brains and hearts of Sprague Dawley male rats. This paper proposes the following explanation for these results. The neurons around the rat's brain and heart form closed electrical circuits and, following Faraday's Law, 900 MHz radiofrequency radiation induces 900 MHz electrical currents in these neural circuits. In turn, these 900 MHz currents...

  9. Study on serum metabonomics of rats exposed to low-dose ionizing radiation, carbon monoxide, benzene and noise

    Qing-rong WANG

    2015-07-01

    Full Text Available Objective To investigate the combined effects of low-dose ionizing radiation, carbon monoxide, benzene and noise on serum metabolites and the mechanism of injury induced by these complex environmental factors in rats. Methods  Sixteen adult SD rats were randomly divided into control group and exposed group (8 each. The exposed group received the combined effect every day for 7 days. At the end of experiment, sera were collected from the abdominal aorta of rats. The metabolic fingerprint of serum was obtained by 1H nuclear magnetic resonance (1H NMR spectroscopy and determined with pattern recognition techniques of principal component analysis (PCA and orthogonal signal correction-partial least squares (OSC-PLS. The similarities and differences in metabolic profiles between two groups were visualized by SIMCA-P software. Results The rat serum 1H NMR spectra revealed different metabolic spectra between the control group and exposed group. The OSC-PLS plots of the serum samples presented respectively marked clustering between the two groups. Compared with the control group, the contents of lipid, high density lipoprotein, glycine/glucose, N-acetyl glycoprotein 1, N-acetyl glycoprotein 2, phosphatidyl choline and unsaturated fatty acid increased, while those of lactic acid, threonine/lipid, alanine, creatine, glycerylphosphorylcholine/ trimethylamine oxide, low density lipoprotein/high density lipoprotein, low density lipoprotein, very low density lipoprotein/ low density lipoprotein, very low density lipoprotein and saturated fatty acid decreased. Conclusions Combination of low-dose ionizing radiation, carbon monoxide, benzene and noise could induce changes of serum metabolites in rats, involving in immune function, renal function and energy metabolism. The NMR-based-metabonomics method has potential of application in research on combined biological effects of the complex environmental factors. DOI: 10.11855/j.issn.0577-7402.2015.07.09

  10. Underwater noise due to precipitation

    Crum, Lawrence A.; Pumphrey, Hugh C.; Prosperetti, Andrea

    1989-01-01

    In 1959, G. Franz published a thorough investigation of the underwater sound produced by liquid drop impacts [G. Franz, J. Acoust. Soc. Am. 31, 1080 (1959)]. He discovered that, under certain conditions, a gas bubble was entrained by the impacting droplet, and the subsequent oscillation of this b...

  11. Noise reduction technology reduces radiation dose in chronic total occlusions percutaneous coronary intervention: a propensity score-matched analysis.

    Maccagni, Davide; Benincasa, Susanna; Bellini, Barbara; Candilio, Luciano; Poletti, Enrico; Carlino, Mauro; Colombo, Antonio; Azzalini, Lorenzo

    2018-03-23

    Chronic total occlusions (CTO) percutaneous coronary intervention (PCI) is associated with high radiation dose. Our study aim was to evaluate the impact of the implementation of a noise reduction technology (NRT) on patient radiation dose during CTO PCI. A total of 187 CTO PCIs performed between February 2016 and May 2017 were analyzed according to the angiographic systems utilized: Standard (n = 60) versus NRT (n = 127). Propensity score matching (PSM) was performed to control for differences in baseline characteristics. Primary endpoints were Cumulative Air Kerma at Interventional Reference Point (AK at IRP), which correlates with patient's tissue reactions; and Kerma Area Product (KAP), a surrogate measure of patient's risk of stochastic radiation effects. An Efficiency Index (defined as fluoroscopy time/AK at IRP) was calculated for each procedure. Image quality was evaluated using a 5-grade Likert-like scale. After PSM, n = 55 pairs were identified. Baseline and angiographic characteristics were well matched between groups. Compared to the Standard system, NRT was associated with lower AK at IRP [2.38 (1.80-3.66) vs. 3.24 (2.04-5.09) Gy, p = 0.035], a trend towards reduction for KAP [161 (93-244) vs. 203 (136-363) Gycm 2 , p = 0.069], and a better Efficiency Index [16.75 (12.73-26.27) vs. 13.58 (9.92-17.63) min/Gy, p = 0.003]. Image quality was similar between the two groups (4.39 ± 0.53 Standard vs. 4.34 ± 0.47 NRT, p = 0.571). In conclusion, compared with a Standard system, the use of NRT in CTO PCI is associated with lower patient radiation dose and similar image quality.

  12. Radiation dose to workers due to the inhalation of dust during granite fabrication

    Zwack, L M; Stewart, J H; McCarthy, J F; Allen, J G; McCarthy, W B

    2014-01-01

    There has been very little research conducted to determine internal radiation doses resulting from worker exposure to ionising radiation in granite fabrication shops. To address this issue, we estimated the effective radiation dose of granite workers in US fabrication shops who were exposed to the maximum respirable dust and silica concentrations allowed under current US regulations, and also to concentrations reported in the literature. Radiation doses were calculated using standard methods developed by the International Commission on Radiological Protection. The calculated internal doses were very low, and below both US occupational standards (50 mSv yr −1 ) and limits applicable to the general public (1 mSv yr −1 ). Workers exposed to respirable granite dust concentrations at the US Occupational Safety and Health Administration (OSHA) respirable dust permissible exposure limit (PEL) of 5 mg m −3 over a full year had an estimated radiation dose of 0.062 mSv yr −1 . Workers exposed to respirable granite dust concentrations at the OSHA silica PEL and at the American Conference of Governmental Industrial Hygienists Threshold Limit Value for a full year had expected radiation doses of 0.007 mSv yr −1 and 0.002 mSv yr −1 , respectively. Using data from studies of respirable granite dust and silica concentrations measured in granite fabrication shops, we calculated median expected radiation doses that ranged from <0.001 to 0.101 mSv yr −1 . (paper)

  13. Perceptual consequences of different signal changes due to binaural noise reduction: do hearing loss and working memory capacity play a role?

    Neher, Tobias; Grimm, Giso; Hohmann, Volker

    2014-01-01

    In a previous study, ) investigated whether pure-tone average (PTA) hearing loss and working memory capacity (WMC) modulate benefit from different binaural noise reduction (NR) settings. Results showed that listeners with smaller WMC preferred strong over moderate NR even at the expense of poorer speech recognition due to greater speech distortion (SD), whereas listeners with larger WMC did not. To enable a better understanding of these findings, the main aims of the present study were (1) to explore the perceptual consequences of changes to the signal mixture, target speech, and background noise caused by binaural NR, and (2) to determine whether response to these changes varies with WMC and PTA. As in the previous study, four age-matched groups of elderly listeners (with N = 10 per group) characterized by either mild or moderate PTAs and either better or worse performance on a visual measure of WMC participated. Five processing conditions were tested, which were based on the previously used (binaural coherence-based) NR scheme designed to attenuate diffuse signal components at mid to high frequencies. The five conditions differed in terms of the type of processing that was applied (no NR, strong NR, or strong NR with restoration of the long-term stimulus spectrum) and in terms of whether the target speech and background noise were processed in the same manner or whether one signal was left unprocessed while the other signal was processed with the gains computed for the signal mixture. Comparison across these conditions allowed assessing the effects of changes in high-frequency audibility (HFA), SD, and noise attenuation and distortion (NAD). Outcome measures included a dual-task paradigm combining speech recognition with a visual reaction time (VRT) task as well as ratings of perceived effort and overall preference. All measurements were carried out using headphone simulations of a frontal target speaker in a busy cafeteria. Relative to no NR, strong NR was found

  14. Improved simulation of Antarctic sea ice due to the radiative effects of falling snow

    Li, J.-L. F.; Richardson, Mark; Hong, Yulan; Lee, Wei-Liang; Wang, Yi-Hui; Yu, Jia-Yuh; Fetzer, Eric; Stephens, Graeme; Liu, Yinghui

    2017-08-01

    Southern Ocean sea-ice cover exerts critical control on local albedo and Antarctic precipitation, but simulated Antarctic sea-ice concentration commonly disagrees with observations. Here we show that the radiative effects of precipitating ice (falling snow) contribute substantially to this discrepancy. Many models exclude these radiative effects, so they underestimate both shortwave albedo and downward longwave radiation. Using two simulations with the climate model CESM1, we show that including falling-snow radiative effects improves the simulations relative to cloud properties from CloudSat-CALIPSO, radiation from CERES-EBAF and sea-ice concentration from passive microwave sensors. From 50-70°S, the simulated sea-ice-area bias is reduced by 2.12 × 106 km2 (55%) in winter and by 1.17 × 106 km2 (39%) in summer, mainly because increased wintertime longwave heating restricts sea-ice growth and so reduces summer albedo. Improved Antarctic sea-ice simulations will increase confidence in projected Antarctic sea level contributions and changes in global warming driven by long-term changes in Southern Ocean feedbacks.

  15. The Generation, Radiation and Prediction of Supersonic Jet Noise. Volume 1

    1978-10-01

    supersonic Jet noise, the U. S. Air Force and the U. S. Department of Transportation Jointly Initiated a series of research contracts directed toward this need...ofMeasurdUAiDigPNOLE Specta an PreictiosDBaedLo 9ih0eqec LiEDICTIEquation Solutos eimTmeaueJt TP 80.Mthd1 *7 60 .........em131 1 (a 6300 I dB 100 90j 80...C3 - -21 Vjm 2Ao/a, a 2 de C4 - 21 Z- Ao, C5 - - 2IH 2VIMM6, and C6 - iVAob/. The form of j, for r >r m may be found by substituting Equation (3-107

  16. Disorders of the endocrine system due to radiation and cytotoxic chemotherapy

    Shalet, S.M.

    1983-01-01

    Panhypopituitarism, infertility, gynaecomastia, impaired growth leading to short stature, failure to undergo normal pubertal development, hyperparathyroidism, hypothyroidism and thyroid tumours may complicate the treatment of malignant disease. The complexity of modern anti-cancer treatment has made it more difficult to delineate the exact aetiological role of radiotherapy and cytotoxic chemotherapy as many patients receive both modalities of therapy. In addition, combination chemotherapy has largely replaced treatment with a single cytotoxic drug, which means that it is often impossible to estimate the contribution of any one single drug to the adverse side effects of chemotherapy. The biological effect of a given radiation treatment regime depends not only on the total radiation dose received but also the method of irradiation, number of fractions, fraction size and duration of irradiation. Only a limited amount of information is available on dose-time relationships for radiation-induced damage to endocrine glands. (author)

  17. Analysis of the contended health risks due to digitally modulated mobile phone radiation

    Liesenkoetter, B.

    2002-01-01

    In the public discussion regarding the health risks of mobile phone system radiation, it is emphasized that the pulse slope of digital modulation, as defined in the GSM-Standard, will cause biological effects. In contrast, the high field strength of broadcasting and television radiation is not considered to be relevant. This paper compares quantitatively the slope of the digital GSM pulses with that of the synchronizing pulse of the television signal. The result shows clearly that the pulse spectrum of the television signal contains that of the GSM signal; in addition, the synchronizing impulse of television exhibits a much steeper slope. Considering the countrywide normal radiation intensities of television and mobile phone systems, it can be stated that the worldwide exposure to the common television signals over more than 50 years can disprove the contention of adverse biological health effects of the pulse slope of digitally modulated radiofrequency. (orig.) [de

  18. Disorders of the endocrine system due to radiation and cytotoxic chemotherapy

    Shalet, S M [Christie Hospital and Holt Radium Inst., Manchester (UK)

    1983-11-01

    Panhypopituitarism, infertility, gynaecomastia, impaired growth leading to short stature, failure to undergo normal pubertal development, hyperparathyroidism, hypothyroidism and thyroid tumours may complicate the treatment of malignant disease. The complexity of modern anti-cancer treatment has made it more difficult to delineate the exact aetiological role of radiotherapy and cytotoxic chemotherapy as many patients receive both modalities of therapy. In addition, combination chemotherapy has largely replaced treatment with a single cytotoxic drug, which means that it is often impossible to estimate the contribution of any one single drug to the adverse side effects of chemotherapy. The biological effect of a given radiation treatment regime depends not only on the total radiation dose received but also the method of irradiation, number of fractions, fraction size and duration of irradiation. Only a limited amount of information is available on dose-time relationships for radiation-induced damage to endocrine glands.

  19. Low power radiofrequency electromagnetic radiation for the treatment of pain due to osteoarthritis of the knee

    U. Santosuosso

    2011-09-01

    Full Text Available Different techniques have been used in some rheumatic diseases to induce a therapeutic effect by heating deep tissues. These techniques are commonly known as ‘thermotherapy’ (1-4. It should be observed that adequate heating of deep tissues cannot be obtained by conduction or convection of heat because the skin and subcutaneous fat are good thermal insulators and because heating is reduced by blood flow in superficial vessels. Heating of deep tissues can instead be obtained by conversion of other forms of energy into heat. Conversion heat is generated by different types of radiations absorbed by deep tissues: when radiation interacts with tissues, some energy is converted into heat. High power radiofrequency electromagnetic radiation (RF, which produces strong thermal energy, has been widely applied in medicine for ablative procedures (5-7.

  20. Changes in tumor cell response due to prolonged dose delivery times in fractionated radiation therapy

    Paganetti, Harald

    2005-01-01

    Purpose: Dynamic radiation therapy, such as intensity-modulated radiation therapy, delivers more complex treatment fields than conventional techniques. The increased complexity causes longer dose delivery times for each fraction. The cellular damage after a full treatment may depend on the dose rate, because sublethal radiation damage can be repaired more efficiently during prolonged dose delivery. The goal of this study was to investigate the significance of this effect in fractionated radiation therapy. Methods and Materials: The lethal/potentially lethal model was used to calculate lesion induction rates for repairable and nonrepairable lesions. Dose rate effects were analyzed for 9 different cell lines (8 human tumor xenografts and a C3H10T1/2 cell line). The effects of single-fraction as well as fractionated irradiation for different dose rates were studied. Results: Significant differences can be seen for dose rates lower than about 0.1 Gy/min for all cell lines considered. For 60 Gy delivered in 30 fractions, the equivalent dose is reduced by between 1.3% and 12% comparing 2 Gy delivery over 30 min per fraction with 2 Gy delivery over 1 min per fraction. The effect is higher for higher doses per fraction. Furthermore, the results show that dose rate effects do not show a simple correlation with the α/β ratio for ratios between 3 Gy and 31 Gy. Conclusions: If the total dose delivery time for a treatment fraction in radiation therapy increases to about 20 min, a correction for dose rate effects may have to be considered in treatment planning. Adjustments in effective dose may be necessary when comparing intensity-modulated radiation therapy with conventional treatment plans

  1. Radiation hazards due to activated corrosion and neutron sputtering products in fusion reactor coolant and tritium breeding fluids

    Klein, A.C.; Vogelsang, W.F.

    1985-01-01

    The accumulation of radioactive corrosion and neutron sputtering products on the surfaces of components in fusion reactor coolant and tritium breeding systems can cause significant personnel access problems. Remote maintenance techniques or special treatment may be required to limit the amount of radiation exposure to plant operational and maintenance personnel. A computer code, RAPTOR, has been developed to estimate the transport of this activated material throughout a fusion heat transfer and/or tritium breeding material loop. A method is devised which treats the components of the loop individually and determines the source rates, deposition and erosion rates, decay rates, and purification rates of these radioactive materials. RAPTOR has been applied to the MARS and Starfire conceptual reactor designs to determine the degree of the possible radiation hazard due to these products. Due to the very high corrosion release rate by HT-9 when exposed to LiPb in the MARS reactor design, the radiation fields surrounding the primary system will preclude direct contact maintenance even after shutdown. Even the removal of the radioactive LiPb from the system will not decrease the radiation fields to reasonable levels. The Starfire primary system will exhibit radiation fields similar to those found in present pressurized water reactors. (orig.)

  2. Findings of thyroid ultrasonography in patients with hypothyroidism exposed to ionizing radiation due to Chernobyl accident

    Grid'ko, O.M.

    1997-01-01

    Comparative analysis of the findings of clinical and ultrasound study of the thyroid gland in 403 participants of the accident clean-up irradiated in the 'iodine' period and 57 patients with hypothyroidism (of them, 46 were exposed to radiation in the 'iodine' period and 11 in 'non-iodine' one) was carried out. The disease dynamics was investigated in 81 patients with acute radiation sickness. The structural changes suggest different ways of hypothyroidism development in the exposed persons and manifest themselves in two main clinical forms of the disease, atrophic and hypertrophic ones

  3. Growth, physiological, biochemical and productive changes in peas due to gamma radiation effect

    Stajkov, G.; Ivanov, K.; Antonov, M.

    1985-01-01

    Investigations concerning the mechanism of the stimulating effect of low doses of gamma radiation on peas were made in 1971-1983. Results showed that: a) gamma radiation with 1000 R enhanced the level and activity of indolyl auxines gibberellins and in the seeds, causing specific changes in catalase and peroxidase activity; b) the content of crude protein and essential aminoacids was raised; c) grain yield increased by 16% as compared to the control; d) the dose 1000 R proved to be the optimal one

  4. DNA damage in human lymphocytes due to synergistic interaction between ionizing radiation and pesticide

    Kim, J. K.; Lee, K. H.; Lee, B. H.; Chun, K. J.

    2001-01-01

    Biological risks may arise from the possibility of the synergistic interaction between harmful factors such as ionizing radiation and pesticide. The effect of pesticide on radiation-induced DNA damage in human in human blood lymphocytes was evaluated by the single cell gel electrophoresis (SCGE) assay. The lymphocytes, with or without pretreatment of the pesticide, were exposed to 2.0 Gy of gamma ray. Significantly increased tail moment, which was a marker of DNA strand breaks in SCGE assay, showed an excellent dose-response relationship. The present study confirms that the pesticide has the cytotoxic effect on lymphocytes and that it interacts synergistically with ionizing radiationon DNA damage, as well

  5. State of enforcement of the law concerning prevention from radiation hazards due to radio-isotopes

    1977-01-01

    In view of the recent advance of radiation utilization in many fields, the situation as of the end of fiscal 1976 under the law is described. The statistics on the number of enterprises concerning radioisotope usage, sales and waste-treatment are first given. Then, the measures taken by the Science and Technology Agency to improve radiation hazard prevention are explained, and cooperation with other governmental offices, efforts by the enterprises, steps taken for the enterprises of nondestructive testing, hospitals, universities, etc., and restudy on the law are described. (Mori, K.)

  6. Direct radiative forcing due to aerosols in Asia during March 2002.

    Park, Soon-Ung; Jeong, Jaein I

    2008-12-15

    The Asian dust aerosol model (ADAM) and the aerosol dynamic model including the gas-aerosol interaction processes together with the Column Radiation Model (CRM) of Community Climate Model 3 and the output of the fifth generation of meso-scale model (MM5) in a grid 60 x 60 km2 in the Asian domain (70-150E, Equator-50N) have been employed to estimate direct radiative forcing of the Asian dust and the anthropogenic aerosols including the BC, OC, secondary inorganic aerosol (SIA), mixed type aerosol (dust+BC+OC+SIA) and sea salt aerosols at the surface, the top of atmosphere (TOA) and in the atmosphere for the period of 1-31 March 2002 during which a severe Asian dust event has been occurred in the model domain. The results indicate that the ADAM model and the aerosol dynamic model simulate quite well the spatial and temporal distributions of the mass concentration of aerosols with the R2 value of more than 0.7. The estimated mean total column aerosol mass in the analysis domain for the whole period is found to be about 78 mg m(-2), of which 66% and 34% are, respectively, contributed by the Asian dust aerosol and all the other anthropogenic aerosols. However, the direct radiative forcing contributed by the Asian dust aerosol is about 22% of the mean radiative forcing at the surface (-6.8 W m(-2)), about 31% at the top of atmosphere (-2.9 W m(-2)) and about 13% in the atmosphere (3.8 W m(-2)), suggesting relatively inefficient contribution of the Asian dust aerosol on the direct radiative forcing compared to the anthropogenic aerosols. The aerosol direct radiative forcing at the surface is mainly contributed by the mixed type aerosol (30%) and the SIA aerosol (25%) while at the top of atmosphere it is mainly contributed by the SIA aerosol (43%) and the Asian dust aerosol (31%) with positively (warming) contributed by BC and mixed type aerosols. The atmosphere is warmed mainly by the mixed type aerosol (55%) and the BC aerosol (26%). However, the largest radiative

  7. Validation of modelling the radiation exposure due to solar particle events at aircraft altitudes

    Beck, P.; Bartlett, D. T.; Bilski, P.; Dyer, C.; Fluckiger, E.; Fuller, N.; Lantos, P.; Reitz, G.; Ruhm, W.; Spurný, František; Taylor, G.; Trompier, F.; Wissmann, F.

    2008-01-01

    Roč. 131, č. 1 (2008), s. 51-58 ISSN 0144-8420. [Annual Meeting of the European-Radiation-Dosimetry-Group (EURADOS). Paris, 21.01.2008-25.01.2008] R&D Projects: GA MŠk 1P05OC032 Grant - others:Evropské společenství(XE) ILSRA - 2004 - 248 Institutional research plan: CEZ:AV0Z10480505 Keywords : on-board airplanes * cosmic radiation * simulations Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.951, year: 2008

  8. Possible Explanation for Cancer in Rats due to Cell Phone Radio Frequency Radiation

    Feldman, Bernard J.

    Very recently, the National Toxicology Program reported a correlation between exposure to whole body 900 MHz radio frequency radiation and cancer in the brains and hearts of Sprague Dawley male rats. Assuming that the National Toxicology Program is statistically significant, I propose the following explanation for these results. The neurons around the brain and heart form closed electrical circuits and, following Faraday's Law, 900 MHz radio frequency radiation induces 900 MHz electrical currents in these neural circuits. In turn, these 900 MHz currents in the neural circuits generate sufficient localized heat in the neural cells to shift the equilibrium concentration of carcinogenic radicals to higher levels and thus, to higher incidences of cancer.

  9. Direct radiative forcing due to aerosols in Asia during March 2002

    Park, Soon-Ung; Jeong, Jaein I.

    2008-01-01

    The Asian dust aerosol model (ADAM) and the aerosol dynamic model including the gas-aerosol interaction processes together with the Column Radiation Model (CRM) of Community Climate Model 3 and the output of the fifth generation of meso-scale model (MM5) in a grid 60 x 60 km 2 in the Asian domain (70-150E, Equator-50N) have been employed to estimate direct radiative forcing of the Asian dust and the anthropogenic aerosols including the BC, OC, secondary inorganic aerosol (SIA), mixed type aerosol (dust + BC + OC + SIA) and sea salt aerosols at the surface, the top of atmosphere (TOA) and in the atmosphere for the period of 1-31 March 2002 during which a severe Asian dust event has been occurred in the model domain. The results indicate that the ADAM model and the aerosol dynamic model simulate quite well the spatial and temporal distributions of the mass concentration of aerosols with the R 2 value of more than 0.7. The estimated mean total column aerosol mass in the analysis domain for the whole period is found to be about 78 mg m -2 , of which 66% and 34% are, respectively, contributed by the Asian dust aerosol and all the other anthropogenic aerosols. However, the direct radiative forcing contributed by the Asian dust aerosol is about 22% of the mean radiative forcing at the surface (- 6.8 W m -2 ), about 31% at the top of atmosphere (- 2.9 W m -2 ) and about 13% in the atmosphere (3.8 W m -2 ), suggesting relatively inefficient contribution of the Asian dust aerosol on the direct radiative forcing compared to the anthropogenic aerosols. The aerosol direct radiative forcing at the surface is mainly contributed by the mixed type aerosol (30%) and the SIA aerosol (25%) while at the top of atmosphere it is mainly contributed by the SIA aerosol (43%) and the Asian dust aerosol (31%) with positively (warming) contributed by BC and mixed type aerosols. The atmosphere is warmed mainly by the mixed type aerosol (55%) and the BC aerosol (26%). However, the largest

  10. Micro-discharge noise and radiation damage of silicon microstrip sensors

    Ohsugi, T.; Iwata, Y.; Ohyama, H.; Ohmoto, T.; Yoshikawa, M.; Handa, T.; Kurino, K.; Fujita, K.; Kitabayashi, H.; Tamura, N.; Hatakenaka, T.; Maeohmichi, M.; Takahata, M.; Nakao, M.; Iwasaki, H.; Kohriki, T.; Terada, S.; Unno, Y.; Takashima, R.; Yamamoto, K.; Yamamura, K.

    1996-01-01

    We have examined experimentally some existing ideas for improving the radiation hardness of silicon microstrip sensors. We confirm that the extended electrode and the deep implant-strip proposed on the basis of simulation studies works effectively to suppress micro-discharge as well as junction breakdown of the bias or guard ring. For an integrated coupling capacitor a double layer structure of SiO 2 and Si 3 N 4 provides better radiation hardness than that of single SiO 2 coupling in our design conditions. The onset voltage of the micro-discharge on the bias/guard ring has been studied for an extended electrode and a floating guard ring. (orig.)

  11. Emittance growth due to static and radiative space charge forces in an electron bunch compressor

    Richard Talman

    2009-01-01

    2004 FEL Conference, pp. 18–21, MOCOS05, available at http://www.JACoW.org], a code with similar capabilities. For this comparison an appropriately new, 50 MeV, “standard chicane” is introduced. Unlike CSRTrack (which neglects vertical forces the present simulation shows substantial growth of vertical emittance. But “turning off” vertical forces in the UAL code (to match the CSRTrack treatment brings the two codes into excellent agreement. (iii Results are also obtained for 5 GeV electrons passing through a previously introduced “standard chicane” [Coherent Synchrotron Radiation, CSR Workshop, Berlin 2002, http://www.desy.de/csr] [of the sort needed for linear colliders and free electron lasers (FEL’s currently under design or construction]. Relatively little emittance growth is predicted for typical bunch parameters at such high electron energy. Results are obtained for both round beams and ribbon beams (like those actually needed in practice. Little or no excess emittance growth is found for ribbon bunches compared to round bunches of the same charge and bunch width. The UAL string space charge formulation (like TraFic4 and CSRTrack avoids the regularization step (subtracting the free-space space charge force which is required (to remove divergence in some methods. Also, by avoiding the need to calculate a retarded-time, four-dimensional field history, the computation time needed for realistic bunch evolution calculations is modest. Some theories of bunch dilution, because they ascribe emittance growth entirely to CSR, break down at low energy. In the present treatment, as well as CSR, all free-space Coulomb and magnetic space charge forces (but not image forces, and also the centrifugal space charge force (CSCF are included. Charge-dependent beam steering due to CSCF, as observed recently by Beutner et al. [B. Beutner et al., in Proceedings of FEL Conference, BESSY, Berlin, Germany, 2006, MOPPH009], is also investigated.

  12. Study on the evaluation of radiation doses in dental radiography. Doses and risks due to dental full mouth examination

    Sugimoto, K [Kanagawa Dental Coll., Yokosuka (Japan)

    1980-09-01

    Radiation doses and possible biological risks due to dental full mouth examination (adult: 10-film technique, child: 6-film technique) were evaluated based on preliminary experiments and statistical surveillance of patients' records. Dosimetrical studies were performed by using head and neck phantoms and a dental x-ray tube. Radiation doses were measured by x-ray films and thermoluminescence dosimeters. For the obtained doses of skin, eyes, thyroid gland and bone marrow, the biological risk of leukemia and thyroid cancer was discussed on the statistical basis of patients at Kanagawa Dental College Hospital. The major findings were as follows: The total number of patients who recieved full mouth x-ray examination at Kanagawa Dental College Hospital in 1978 was 1,099. The number of male patients was 382 (3,804 films) and that of female patients was 717 (7,138 films). In both sexes, the number of patients was the greatest in the group of 8 - 14 years of age. The collective doses of bone marrow due to full mouth 10-film examination performed at Kanagawa Dental College Hospital in 1978 were approximately 6.0 rad, which could induce leukemia with a probability of 1/8,000. The collective doses of thyroid gland were approximately 13 rad, which could induce lethal thyroid cancer with a probability of 1/15,000. The radiation dose due to the dental radiography for examination at Kanagawa Dental College Hospital was proved to be apparently below the level that could actually induce radiation injuries. But the collective radiation doses due to dental examination in Japan as a whole were approximately 8,000 times greater than that in Kanagawa Dental College Hospital.

  13. The order for enforcing the law concerning prevention from radiation hazards due to radioisotopes

    1981-01-01

    This rule is established under the provisions of the law on the prevention of radiation injuries by radioisotopes, and the former ordinance No. 14, 1958, is hereby totally amended. Radioisotopes under the law are the isotopes which emit radiation, and of which the concentration exceeds the levels defined by the Director General of the Science and Technology Agency, their compounds or the substances containing these compounds, excluding those defined in the atomic energy act and other particular laws. The apparatuses fitted with radioisotopes under the law are electron capture detectors for gas chromatography. The radiation emitting installations under the law are cyclotron, synchrotron, synchro-cyclotron, linear accelerator, betatron, Van de Graaff accelerator, Cockcroft-Walton's accelerator, etc. The permission of usage under the law shall be obtained for each works or enterprise. Persons who intend to get the permission shall file the application for them attaching the documents describing expected period of usage and other papers specified by the Director General. The total quantity of radioisotopes sealed tightly for each works or enterprise under the law shall be 100 milli-curie. The design of apparatus for the prevention of radiation injuries, the capacities of storage facilities regularly inspected, the period of regular inspection, the confirmation of transport and disposal and fees to be paid, etc. are defined, respectively. (Okada, K.)

  14. Dose factors to calculate the radiation exposure due to radioactive waste air from nuclear facilities

    Brenk, H.D.; Vogt, K.J.

    1977-01-01

    An evaluation of the environmental impact of nuclear plants according to paragraph 45 of the Radiation Protection Directive of the Federal Republic of Germany requires the calculation of dose conversion factors indicating the correlation between the contaminated medium and individual radiation exposure. The present study is to be conceived as a contribution to discussion on this subject. For the determination of radiation exposure caused by the waste air of nuclear plants, models are being specified for computing the dose conversion factors for the external exposure pathways of β-submersion, γ-submersion and γ-radiation from contaminated ground as well as the internal exposure pathways of inhalation and ingestion, which further elaborate and improve the models previously applied, especially as far as the ingestion pathway is concerned, which distinguishes between 6 major food categories. The computer models are applied to those radionuclides which are significan for nuclear emitters, in particular nuclear light-water power stations. The results obtained for the individual exposure pathways and affected organs are specified in the form of tables. For this purpose, calculations were first of all carried out for the so-called 'reference man'. The results can be transferred to population groups with different consumption habits (e.g. vegetarians) by the application of correction factors. The models are capable of being extended with a view to covering other age groups. (orig.) [de

  15. EEG Changes Due to Experimentally Induced 3G Mobile Phone Radiation.

    Roggeveen, Suzanne; van Os, Jim; Viechtbauer, Wolfgang; Lousberg, Richel

    2015-01-01

    The aim of this study was to investigate whether a 15-minute placement of a 3G dialing mobile phone causes direct changes in EEG activity compared to the placement of a sham phone. Furthermore, it was investigated whether placement of the mobile phone on the ear or the heart would result in different outcomes. Thirty-one healthy females participated. All subjects were measured twice: on one of the two days the mobile phone was attached to the ear, the other day to the chest. In this single-blind, cross-over design, assessments in the sham phone condition were conducted directly preceding and following the mobile phone exposure. During each assessment, EEG activity and radiofrequency radiation were recorded jointly. Delta, theta, alpha, slowbeta, fastbeta, and gamma activity was computed. The association between radiation exposure and the EEG was tested using multilevel random regression analyses with radiation as predictor of main interest. Significant radiation effects were found for the alpha, slowbeta, fastbeta, and gamma bands. When analyzed separately, ear location of the phone was associated with significant results, while chest placement was not. The results support the notion that EEG alterations are associated with mobile phone usage and that the effect is dependent on site of placement. Further studies are required to demonstrate the physiological relevance of these findings.

  16. BACTERIAL MORTALITY DUE TO SOLAR RADIATION, COMPARING EXPERIMENTAL AND STATISTICAL EVIDENCE

    Many researchers report that sunlight is a primary stressor of beach indicator bacteria. Some water quality models include code that quantifies the effect of radiation on bacterial decay. For example, the EPA Visual Plumes model includes two coliform and one enterococcus submodel...

  17. Radiation exposure and dosimetry in transplant patients due to Nuclear Medicine studies

    El-Maghraby, T. A. F.; Cairo Univ., Cairo; Camps, J. A. J.; Geleyns, J.; Pauwels, E. K. J.

    2000-01-01

    Organ transplantation is now an accepted method of therapy for treating patients with end stage failure of kidneys, liver, heart or lung. Nuclear Medicine may provide functional data and semi-quantitative parameters. However, one serious factor that hampers the use of nuclear medicine procedures in transplant patients is the general clinical concern about radiation exposure to the patient. This lead the researcher to discuss the effective doses and radiation dosimetry associated with radionuclide procedures used in the management and follow-up of transplant patients. A simple way to place the risk associated with Nuclear Medicine studies in an appropriate context is to compare the dose with that received from more familiar source of exposure such as from a diagnostic X-ray procedure. The radiation dose for the different radiopharmaceuticals used to study transplant organ function ranges between 0.1 and 5.3 mSv which is comparable to X-ray procedures with the exception of 201 Tl and 111 In-antimyosin. Thus Nuclear Medicine studies do not bear a higher radiation risk than the often used X-ray studies in transplant patients

  18. Sensitivity of APSIM/ORYZA model due to estimation errors in solar radiation

    Heinemann, A.B.; Oort, van P.A.J.; Simoes Fernandes, D.; Maia, A.H.N.

    2012-01-01

    Crop models are ideally suited to quantify existing climatic risks. However, they require historic climate data as input. While daily temperature and rainfall data are often available, the lack of observed solar radiation (Rs) data severely limits site-specific crop modelling. The objective of this

  19. Assessment of radiation exposure to miners due to radon and radon daughters

    Przyborowski, S.

    1979-01-01

    An overview is given of the basic considerations regarding the establishment of lung limits for miners exposed to radon and radon daughters. Problems associated with the practical conduct of radiation protection monitoring are also dealt with, for example, the implications of temporal and local variations in activity levels to the mode of sampling and the interpretation of results. (author)

  20. Systematic medical control of the personnel concerning damage due to ionizing radiation

    Djukic, Z.

    1961-01-01

    The department for medical monitoring of the staff employed at the Institute has performed 21395 medical check-ups of the personnel employed in the Institute and individuals who applied for different posts. Some new methods for laboratory analyses specific for personnel exposed to radiation were introduced. The activities of the department were fulfilled according to the plan

  1. Determination of radiation exposure of humans due to dermal contact with radionuclides

    Pratzel, H.G.

    1992-01-01

    It is the aim of this research project to determine the distribution of radioactive substances in the skin and organism, in order to be able to predict from these data the radiation exposure to be expected following contamination of the skin with radionuclides. Further investigations are to be carried out into the suitability of measures of prevention and decontamination. In view of the fact that only small amounts of those compounds are absorbed by the skin, the determination of the parameters chosen was carried out in radionuclide studies in young pigs. With the exception of the skin of the palms and soles, the radiation effects in man could easily be extrapolated from the results of these experiments. The findings revealed permit the following conclusions to be drawn: The incorporation of radioactive substances after dermal contamination is quite unavoidable, even if this is immediately followed by decontamination measures. The degree of incorporation and resulting radiation dose are only minor and remain several orders of magnitude below the dermal radiation dose. If the skin is contaminated with radioactive liquids, the extent of incorporation and accumulation is proportionate to the activity concentration of those liquids. The incorporated radiation dose is in direct proportion to the contaminated skin area and also shows a relationship to the duration of contamination, if the skin is wet. The uptake by the organism may be somewhat reduced, if decontamination is initiated immediately. Dermal protectives may help to reduce skin permeability and, thus, the uptake of radioactivity into the corneal layer and follicles. (orig./MG) [de

  2. The Effect of External Radiation Therapy in management of malignant obstructive Jaundice due to Porta Hepatis metastasis from Stomach Cancer

    Yang, Kwang Mo; Kim, Joon Hee; Kim, Chul Soo; Suh, Hyun Suk; Kim, Re Hwe

    1995-01-01

    Purpose : Since 1983, authors have conducted a study to evaluate the effect of external radiation therapy an to determine affected factors in management of the patients with malignant obstructive jaundice due to porta hepatis metastasis from stomach cancer. Materials and methods : Thirty two patients with malignant obstructive jaundice due to porta hepatis metastasis from gastric cancer were presented. We have analysed 23 patients who were treated with external radiation therapy of more than 3000 cGy. The radiation dose, disease extent at development of jaundice, total bilirubin levels before radiation therapy, differentiation of histology, combined treatment, intent of primary surgery, initial stage of gastric cancer were analyzed to determine affected factors in radiation therapy. External radiation therapy was delivered with a daily dose of 180-300 cGy. 5 times a week fractionation using 4 MeV linear accelerator. The radiation field included the porta hepatis with tumor mass by the abdominal ultrasonography or CT scan. In twenty three patients received more than 3000 cGy, total irradiation dose was ranged from 3000 cGy to 5480 cGy, median 3770 cGy. Among 23 patients, 13 patients were delivered more than equivalent dose of TDF 65(4140 cGy/23fx). Results : Among 23 patients, complete, partial and no response were observed in 13, 5, 5 patients, respectively. The median survival for all patients was 5 months. He significant prolongation of median survival was observed in complete responders(11 months) as compared to partial and no responders(5 months, 5 months, respectively). Out of 13 patients with complete response, 6 patients lived more than a year. Among 13 patients received more than 4140 cGy equivalent dose, complete, partial and no response were observed in 10, 2 and 1 patients, respectively. The median survival for all these patients was 9.5 months. The median survival for complete responders(10/13) was 11.5 months. Among 10 patients receiving less than 4140

  3. Noise suppression by noise

    Vilar, J. M. G. (José M. G.), 1972-; Rubí Capaceti, José Miguel

    2001-01-01

    We have analyzed the interplay between an externally added noise and the intrinsic noise of systems that relax fast towards a stationary state, and found that increasing the intensity of the external noise can reduce the total noise of the system. We have established a general criterion for the appearance of this phenomenon and discussed two examples in detail.

  4. Natural radiation dose due to 210Po and associated risk to certain fishes of Kudankulam Waters, Gulf of Mannar

    Praveen Pole, R.P.; Godwin Wesley, S.; Vijayakumar, B.

    2014-01-01

    With increasing emphasis on environmental protection, concern has switched over from the earlier target human being to non-human species regarding possible radiation risk. Alpha-emitter 210 Po (t 1/2 = 138.4 d) is the most important radionuclide, considering it as a potential natural source of internal radiation dose to marine organisms. Fishes are known to accumulate 210 Po to a large extent through food chains and certain marine fishes are potential bioindicators as they bioaccumulate the target radionuclide from surrounding waters. Hence it is imperative to assess the level of 210 Po and the radiological risk (risk quotient) due to the radiation dose received by different fish species collected from the coastal areas around the nuclear installation at Kudankulam

  5. Morphological Changes of Yeast Cells due to Oxidative Stress by Mercury and Radiation

    Kim, Su Hyoun; Ryu, Tae Ho; Kim, Jin Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2009-05-15

    The yeast Saccharomyces cerevisiae is one of the most important microorganisms employed in industry. Growth rate, mutation, and environmental conditions affect yeast size and shape distributions but, in general, the influence of spatial variations in large-scale bioreactors is not considered. Ionizing radiation induces DNA double strand breaks in the nucleus, In addition, it causes lipid peroxidation, ceramide generation, and protein oxidation in the membrane, cytoplasm, and nucleus. Metal ions are essential to life. However, some metals such as mercury are harmful, even when present at trace amounts. Toxicity of mercury arises mainly from its oxidizing properties. As a metal ion, it induces an oxidative stress or predisposes cells to an oxidative stress, with considerable damage to proteins, lipids and DNA. In this work, we investigated to effect of ionizing radiation (IR) and mercury chloride (II) on cell morphology.

  6. Acoustic radiation force due to arbitrary incident fields on spherical particles in soft tissue

    Treweek, Benjamin C., E-mail: btreweek@utexas.edu; Ilinskii, Yurii A.; Zabolotskaya, Evgenia A.; Hamilton, Mark F. [Applied Research Laboratories, The University of Texas at Austin, P.O. Box 8029, Austin, TX 78713-8029 (United States)

    2015-10-28

    Acoustic radiation force is of interest in a wide variety of biomedical applications ranging from tissue characterization (e.g. elastography) to tissue treatment (e.g. high intensity focused ultrasound, kidney stone fragment removal). As tissue mechanical properties are reliable indicators of tissue health, the former is the focus of the present contribution. This is accomplished through an investigation of the acoustic radiation force on a spherical scatterer embedded in tissue. Properties of both the scatterer and the surrounding tissue are important in determining the magnitude and the direction of the force. As these properties vary, the force computation shows changes in magnitude and direction, which may enable more accurate noninvasive determination of tissue properties.

  7. Polyploidization of rat hepatocytes due to cell fusion under the effect of radiation of different let

    Gil'yano, N.Ya.; Malinovskij, O.V.; Khair, M.B.; Baldychev, A.S.; Smolin, V.A.

    1988-01-01

    The method of flow cytometry was used to study polyploidization of hepatocytes following X-, γ-, and neutron-irradiation. Ionizing radiation was shown to induce cell polyploidization by two different ways: (1) cells and nuclei fusion, and (2) restriction of mitosis after DNA replication. RBE of 14 MeV neutrons with respect to fusion was about 5x10 3 . With neutron irradiation, the densitivity of cells by fusion was not lower than that by chromosome mutations

  8. Polyploidization of rat hepatocytes due to cell fusion under the effect of radiation of different LET

    Khair, M.; Gil'yano, N.Ya.; Malinovskij, O.V.; Smolin, V.A.

    1991-01-01

    The method of flow cytometry was used to study polyploidization of hepatocytes following X-, γ-, and neutron-irradiation. Ionizing radiation was shown to induce cell polyploidization by two different ways: (1) cells and nuclei fusion, and (2) restriction of mitosis after DNA replication. RBE of 14 MeV neutrons with respect to fusion was about 5x10 3 . With neutron irradiation, the sensitivity of cells by fusion was not lower than that by chromosome mutations. (author). 6 refs., 6 figs

  9. Optical vortices and singularities due to interference in atomic radiation near a mirror.

    Li, Xin; Shu, Jie; Arnoldus, Henk F

    2009-11-15

    We consider radiation emitted by an electric dipole close to a mirror. We have studied the field lines of the Poynting vector, representing the flow lines of the electromagnetic energy, and we show that numerous singularities and subwavelength optical vortices appear in this energy flow pattern. We also show that the field line pattern in the plane of the mirror contains a singular circle across which the field lines change direction.

  10. Studies of the ionizing radiation effects on the effluents acute toxicity due to anionic surfactants

    Moraes, Maria Cristina Franco de

    2004-01-01

    Several studies have shown the negative effects of surfactants, as detergents active substance, when discharged on biological sewage wastewater treatment plants. High toxicity may represent a lower efficiency for biological treatment. When surfactants are in aquatic environment they may induce a loss of grease revetment on birds (feather). Depending on the surfactant concentration, several damages to all biotic systems can happen. Looking for an alternative technology for wastewater treatment, efficient for surfactant removal, the present work applied ionizing radiation as an advanced oxidation process for affluents and effluents from Suzano Treatment Station. Such wastewater samples were submitted to radiation using an electron beam from a Dynamic Electron Beam Accelerator from Instituto de Pesquisas Energeticas e Nucleares. In order to assess this proposed treatment efficacy, it was performed acute toxicity evaluation with two test-organisms, the crustacean Daphnia similis and the luminescent bacteria Vibrio fischeri. The studied effluents were: one from a chemical industry (IND), three from sewage plant (affluents - GG, GM and Guaio) and the last biologically treated secondary effluent (EfF), discharged at Tiete river. The applied radiation doses varied from 3 kGy to 50 kGy, being 50 kGy enough for surfactant degradation contained at industrial effluent. For GG, GM and Guaio samples, doses of 6 kGy and 10 kGy were efficient for surfactant and toxicity reduction, representing an average removal that varied from 71.80% to 82.76% and toxicity from 30% to 91% for most the effluents. The final effluent was less toxic than the others and the radiation induced an average 11% removal for anionic surfactant. The industrial effluents were also submitted to an aeration process in order to quantify the contribution of surfactant to the whole sample toxicity, once it was partially removed as foam and several fractions were evaluated for toxicity. (author)

  11. Changes in Handset Performance Measures due to Spherical Radiation Pattern Measurement Uncertainty

    Nielsen, Jesper Ødum; Pedersen, Gert Frølund

    An important characteristic of a mobile handset is its ability to receive and transmit power. One way to characterize the performance of a handset in this respect is to use measurements of the spherical radiation pattern from which the total radiated power (TRP), total isotropic sensitivity (TIS)...... with respect to the environment. Standard deviations up to about 0.5dB and a maximum deviation of about 1.6dB were found....... in the performance measures are investigated for both the GSM-900 and the GSM-1800 band. Despite the deliberately large deviations from the reference position, the changes in TRP and TIS are generally within ±0.5dB with a maximum of about 1.4dB. For the MEG values the results depend on the orientation of the handset...... system that may introduce errors in standardized performance measurements. Radiation patterns of six handsets have been measured while they were mounted at various offsets from the reference position defined by the Cellular Telecommunications & Internet Association (CTIA) certification. The change...

  12. Extra lethal damage due to residual incompletely repaired sublethal damage in hyperfractionated and continuous radiation treatment

    Chen, J.; van de Geijn, J.; Goffman, T. (ROB, DCT, NCI, NIH, Bethesda, Maryland 20892 (US))

    1991-05-01

    In the conventional linear--quadratic model of single-dose response, the {alpha} and {beta} terms reflect lethal damage created {ital during} the delivery of a dose, from two different presumed molecular processes, one linear with dose, the other quadratic. With the conventional one-fraction-per-day (or less) regimens, the sublethal damage (SLD), presumably repairing exponentially over time, is essentially completely fixed by the time of the next dose of radiation. If this assumption is true, the effects of subsequent fractions of radiation should be independent, that is, there should be little, if any, reversible damage left from previous fractions, at the time of the next dose. For multiple daily fractions, or for the limiting case, continuous radiation, this simplification may overlook damaged cells that have had insufficient time for repair. A generalized method is presented for accounting for extra lethal damage (ELD) arising from such residual SLD for hyperfractionation and continuous irradiation schemes. It may help to predict differences in toxicity and tumor control, if any, obtained with unconventional'' treatment regimens. A key element in the present model is the finite size and the dynamic character of the pool of sublethal damage. Besides creating the usual linear and quadratic components of lethal damage, each new fraction converts a certain fraction of the existing SLD into ELD, and creates some new SLD.

  13. Extra lethal damage due to residual incompletely repaired sublethal damage in hyperfractionated and continuous radiation treatment

    Chen, J.; van de Geijn, J.; Goffman, T.

    1991-01-01

    In the conventional linear--quadratic model of single-dose response, the α and β terms reflect lethal damage created during the delivery of a dose, from two different presumed molecular processes, one linear with dose, the other quadratic. With the conventional one-fraction-per-day (or less) regimens, the sublethal damage (SLD), presumably repairing exponentially over time, is essentially completely fixed by the time of the next dose of radiation. If this assumption is true, the effects of subsequent fractions of radiation should be independent, that is, there should be little, if any, reversible damage left from previous fractions, at the time of the next dose. For multiple daily fractions, or for the limiting case, continuous radiation, this simplification may overlook damaged cells that have had insufficient time for repair. A generalized method is presented for accounting for extra lethal damage (ELD) arising from such residual SLD for hyperfractionation and continuous irradiation schemes. It may help to predict differences in toxicity and tumor control, if any, obtained with ''unconventional'' treatment regimens. A key element in the present model is the finite size and the dynamic character of the pool of sublethal damage. Besides creating the usual linear and quadratic components of lethal damage, each new fraction converts a certain fraction of the existing SLD into ELD, and creates some new SLD

  14. On the theory of improved confinement due to stationary multifaceted asymmetric radiation from the edge

    Herrera, J.J.E.

    2002-01-01

    Multifaceted asymmetric radiation from the edge (MARFE's) are toroidally symmetric and poloidally asymmetric radiation bands that occur in tokamaks as a result of a thermal instability, originated by radiation losses. It was observed in TFTR and TEXTOR that they formed as density was increased, and impurities concentrated on the edge. Under certain circumstances, they could evolve into weakly poloidal symmetric structures that cooled the edge of the plasma to a few tens of eV, thus leading to detachment from the limiter. Although non-stationary MARFE's are often precursors of disruptions, the use of a stochastic divertor in TORE-SUPRA, and of feedback controlled gas-puff in HT-7 have proved the existence of stationary MARFE's. Their appearance has been found to depend strongly on the impurity content of the plasma. They trigger internal transport barriers, observed in the electron temperature profiles. The purpose of this work is: to take into account the edge control in order to understand the sustainment of stationary MARFE's, and to propose non-local mechanisms that can explain the formation of internal transport barriers. (author)

  15. On the theory of improved confinement due to stationary multifaceted asymmetric radiation from the edge

    Herrera, J.J.E.; Martinell, J.J.; Morozov, D.Kh.

    2003-01-01

    Multifaceted asymmetric radiation from the edge (MARFE's) are toroidally symmetric and poloidally asymmetric radiation bands that occur in tokamaks as a result of a thermal instability, originated by radiation losses. It was observed in TFfR and TEXTOR that they formed as density was increased, and impurities concentrated on the edge. Under certain circumstances, they could evolve into weakly poloidal symmetric structures that cooled the edge of the plasma to a few tens of eV, thus leading to detachment from the limiter. Although non-stationary MARFE's are often precursors of disruptions, the use of a stochastic divertor in TORESUPRA, and of feedback controlled gas-puff in HT- 7 have proved the existence of stationary MARFE' s. Their appearance has been found to depend strongly on the impurity content of the plasma. They trigger internal transport barriers, observed in the electron temperature profiles. The purpose of this work is to review the evidence of the existence of stationary MARFEs, and whether they can actually lead to improved confinement regimes, through non-local mechanisms. (author)

  16. Radiation doses due to natural radon gas releases from the final disposal facility of spent fuel

    Vesterbacka, K.; Arvela, H.

    1998-03-01

    Building an underground repository for the spent nuclear fuel increases releases of natural radon gas. In the report the radon releases, the resulting doses as well as the radon concentration in the repository air are investigated. There are four optional building locations for the underground repository and three different strategies of construction. Optional sites are Olkiluoto of Eurajoki, Romuvaara of Kuhmo, Haestholmen of Loviisa and Kivetty of Aeaenekoski. The most significant radon sources in the underground repository are the rockwalls and the groundwater leaking to the repository. High groundwater radon concentrations can increase significantly radon concentration in the repository air despite the groundwater leak rate is low. The radon source strength from the rockwalls, groundwater and macadam spreaded on the floor of the repository is estimated in this report. Using these results the radon concentration in the repository is calculated for several air exchange rates. Data from petrological studies performed at the optional building sites as well as the measurement data of the Radiation and Nuclear Safety Authority has been utilized. Rough approximations were needed when estimating the radon source strength. The estimated total radon source strength varies between 1 - 600 MBq/h depending on the repository construction strategy. Repository indoor air radon concentration with no air exchange varies between 0,7 - 120 kBq/m 3 . Using the most probable estimates on radon source strength, the allowed indoor radon concentration of 400 Bq/m 3 at workplaces is achieved by using the air exchange rate of 0,5 l/h in every optional repository. Repository exhaust air and the pile of macadam increases the radon levels in the environment. The radiation dose to the critical person depends on the open volume of the repository. The annual radiation dose calculated from the most probable radon source strength at the distance of 500 metres is below 0,005 mSv at all sites

  17. Disruption to radiation therapy sessions due to anxiety among patients receiving radiation therapy to the head and neck area can be predicted using patient self-report measures.

    Clover, Kerrie; Oultram, Sharon; Adams, Catherine; Cross, Laraine; Findlay, Naomi; Ponman, Leah

    2011-12-01

    This analysis sought to determine whether patient self-report measures were associated with disruption to radiation therapy sessions due to anxiety among cancer patients undergoing radiation therapy to the head and neck region. A cohort of patients undergoing radiation therapy to the head and neck region at a major regional radiation oncology treatment centre (ROTC) in Australia completed self-report measures of anxiety, history of panic and fears relevant to use of an immobilising mask. The treating Radiation Therapist (RT) rated the level of session disruption due to patient anxiety during the Computerised Tomography/Simulation (CT/Sim) (baseline) session and first treatment session. Complete data were obtained for 90 patients. RTs rated 11 and 24% of patients as having some level of session disruption session due to anxiety at baseline and Treatment 1, respectively. Five factors were significantly associated with session disruption at baseline in bivariate analyses: currently taking psycho-active medication (p=0.008); fear of enclosed spaces (p=0.006); fear of face being covered up (p=0.006); fear of movement restriction (p=0.041) and ever had an anxiety attack (p=0.034). Sensitivity ranged from 0.57 to 0.75 and specificity ranged from 0.68 to 0.90. Only session disruption at baseline predicted disruption at Treatment 1 (pdisruption and patient self-report measures which might be used to flag patients for prophylactic treatment. Further development and replication in a larger sample is warranted before introduction of these measures into routine practice. Copyright © 2010 John Wiley & Sons, Ltd.

  18. Radiation from a Relativistic Electron Beam in a Molecular Medium due to Parametric Pumping by a Strong Electromagnetic Wave,

    1981-02-01

    UNIVERSITY OF MARYLAND DEPARTMENT OF PHYSICS 4WJD ASTRONOMY COLLG PAM A 2 3i 81 4 30) 235. RADIATION FROM A .ELATIVISTIC_§LECTRON BEAM IN AZOLECULAR...A MOLECULAR MEDIUM DUE TO PARAMETRIC PUMPING BY A STRONG ELECTROMAGNETIC WAVE L. Stenflo Department of Plasma Physics Umel University S-90187 Umel...GUteborg, Sweden and Laboratory for Plasma and Fusion Energy Studies University of Maryland College Park, Maryland 20742 Physics Publication Number 81

  19. Nonlinear real index of refraction variations of a gas medium due to a monochromatic radiation near resonance

    Vasconcellos, J.I.C.

    1982-01-01

    The nonlinear real index of refraction variations of a gas medium due to a strong monochromatic radiation causing saturation effects is calculated. The gas is supposed to be composed of two-level molecules with which the external field is nearly resonant. It is assumed homogeneous (hard collisions, spontaneous decay) and inhomogeneous (Doppler effect) broadening mechanisms acting on the real index of refraction of the medium. The nonlinear dispersion of the medium is studied as a function of the detuning frequencies, saturation conditions and for various ratios between the homogeneous and inhomogeneous linewidths. In particular, the modification of the index of refraction due to saturation effects are emphasized. (Author) [pt

  20. Derangement of cellular plasma membranes due to non-lethal radiation doses

    Koeteles, G.J.; Kubasova, T.; Somosy, Z.; Horvath, L.

    1983-01-01

    Earlier observations in the laboratory on fibroblasts and various blood cells of animal and human origins pointed to alteration of concanavalin A binding sites of plasma membranes as well as to concomitant morphological changes and scanning electron microscopic appearance of cell surfaces following sub-lethal doses of X-, fission neutron and beta irradiations. The effects appeared early and existed temporarily; their intensities and the restitution of membrane function depended on radiation doses, types and conditions of cells. In the present paper further aspects of structural and functional derangements of plasma membranes are introduced which were provoked by X- and tritium beta irradiation in the dose range up to 2.5 Gy and in the concentration range from 3.7 kBq/mL, respectively. The state of membrane structure was followed by bindings of various ligands of different receptor requirements, concanavalin A, cationized ferritin and polio virus. In the case of X-irradiation the binding conditions suggest the shift of overall negative surface charges to less negative ones. It was also found that radiation-induced phenomena appear on the cell surface unevenly. Long- and short-term treatments of cells with 3 H-thymidine and 3 H-water also perturb the plasma membrane; beta irradiation affects it directly. Membrane structure and function are suggested to offer good biological models to study correlation of energy deposition and biological effects, both restricted to domains of nanometre range. The data give evidence for radiation-induced membrane alterations in the sub-lethal or non-lethal ranges which might have consequences in the development of stochastic and non-stochastic effects. (author)

  1. Estimation of radiation exposures due to the exemption of beta-contaminated radioactive materials

    Beltz, D.; Botsch, W.; Huettig, M.; Boerchers, F.

    2005-01-01

    The authors have checked the individual clearance levels of pure beta-emitters (Sr 89, Sr 90+) according to Anlage III, Table 1, column 8 and 10 StrlSchV for the clearance of buildings. According to Monte-Carlo simulations the direct exposure coming from contaminated parts of a building can exceed the range of trivial doses significantly, although the clearance levels are met. Furthermore, the high radiation level outside a barrel of beta-emitting waste showed that even the mass-specific clearance levels for the disposal of beta-contaminated waste need to be reviewed. (orig.)

  2. Estimation of health effects due to elevated radiation exposure levels in structures

    Marks, S.; Cross, F.T.; Denham, D.H.; Kennedy, W.E. Jr.

    1985-02-01

    Uranium mill tailings were used as landfill for many years in the United States before the health risk associated with such use was recognized. Occupants of buildings erected on or adjacent to contaminated landfills may experience radiation exposures sufficient to warrant remedial action. Estimates of the cost-effectiveness of the remedial measures may be provided using a combination of occupancy data, appropriate risk coefficients and projected costs. This effort is in support of decisions by the US Department of Energy (DOE) to conduct remedial action at such locations. The methods used in this project, with examples of their application, will be presented in this paper

  3. Doppler Broadening of In-Flight Positron Annihilation Radiation due to Electron Momentum

    Hunt, A. W.; Cassidy, D. B.; Sterne, P. A.; Cowan, T. E.; Howell, R. H.; Lynn, K. G.; Golevchenko, J. A.

    2001-01-01

    We report the first observation of electron momentum contributions to the Doppler broadening of radiation produced by in-flight two-photon annihilation in solids. In these experiments an approximately 2.5 MeV positron beam impinged on thin polyethylene, aluminum, and gold targets. Since energetic positrons easily penetrate the nuclear Coulomb potential and do not cause a strong charge polarization, the experimental annihilation line shapes agree well with calculations based on a simple independent-particle model. Moreover, annihilations with the deepest core electrons are greatly enhanced

  4. Hydroacoustic measurements of the radiated noise from Wave Energy Converters in the Lysekil project and project WESA

    Haikonen, Kalle; Sundberg, Jan; Leijon, Mats

    2013-01-01

    Field measurements of the hydroacoustic noise from Wave Energy Converters (WECs) in the Lysekil project at Uppsala University and the Project WESA (joint effort between Uppsala University (Lead Partner), Ålands Teknikkluster r.f. and University of Turku) are presented. Anthropogenic noise is increasing in the oceans world wide and wave energy conversion may contribute to this noise, but to what extent? The main objective in this study is to examine the noise from full scale operating WECs in ...

  5. Noise from cooling towers of power parks

    Zakaria, J.; Moore, F.K.

    1975-01-01

    A study is presented of the noise pollution problem for large power parks proposed for the future. Such parks might have an area of about 75 sq. miles, and a generating capacity up to 48000 MW. A comparative analysis has been done for natural and mechanical-draft wet towers as the major sources of acoustic power. Noise radiation from single isolated towers as well as from a dispersed array of towers has been considered for both types of cooling systems. Major noise attenuation effects considered are due to the atmospheric absorption and A-weighting. Conditions of 60F and 70 percent relative humidity in a still atmosphere have been assumed

  6. Direct radiative feedback due to biogenic secondary organic aerosol estimated from boreal forest site observations

    Lihavainen, Heikki; Asmi, Eija; Aaltonen, Veijo; Makkonen, Ulla; Kerminen, Veli-Matti

    2015-01-01

    We used more than five years of continuous aerosol measurements to estimate the direct radiative feedback parameter associated with the formation of biogenic secondary organic aerosol (BSOA) at a remote continental site at the edge of the boreal forest zone in Northern Finland. Our upper-limit estimate for this feedback parameter during the summer period (ambient temperatures above 10 °C) was −97 ± 66 mW m −2 K −1 (mean ± STD) when using measurements of the aerosol optical depth (f AOD ) and −63 ± 40 mW m −2 K −1 when using measurements of the ‘dry’ aerosol scattering coefficient at the ground level (f σ ). Here STD represents the variability in f caused by the observed variability in the quantities used to derive the value of f. Compared with our measurement site, the magnitude of the direct radiative feedback associated with BSOA is expected to be larger in warmer continental regions with more abundant biogenic emissions, and even larger in regions where biogenic emissions are mixed with anthropogenic pollution. (letter)

  7. Comet assay optimization for assessment of DNA damage due to radiation exposure

    Dwi Ramadhani; Devita Tetriana; Viria Agesti Suvifan

    2016-01-01

    Comet assay can be used to measure the deoxyribonucleic acid (DNA) damage level caused by ionizing radiation exposure in peripheral blood lymphocytes. The principle of the comet assay is based on the amount of denatured DNA fragments that migrated out of the cell nucleus during electrophoresis. There are several aspects that must be concerned when doing the comet assay. For example the agarose concentration, duration of alkaline incubation, electrophoresis conditions (time, temperature, and voltage gradient), and the measurement parameters that used in analyze the comet. Percentage of DNA in the comet tail (% tail DNA) is strongly recommended as a parameter when analyze the comet because it can be converted to lesions per 106 base pairs (bp) using calibration curve that show relationship between the dose of ionizing radiation and % tail DNA. To obtain an accurate result, the calibration curve must be made and comet should be analyzing using image processing analysis software since it can be increase the precision and reduce the subjectivity of the measurement process. (author)

  8. Assessment of natural radioactivity levels and radiation hazards due to cement industry

    El-Taher, A.; Abdel Halim, A.S.

    2010-01-01

    The cement industry is considered as one of the basic industries that plays an important role in the national economy of developing countries. Activity concentrations of 226 Ra, 232 Th and 40 K in Assiut cement and other local cement types from different Egyptian factories has been measured by using γ-ray spectrometry. From the measured γ-ray spectra, specific activities were determined. The measured activity concentrations for these natural radionuclides were compared with the reported data for other countries. The average values obtained for 226 Ra, 232 Th and 40 K activity concentration in different types of cement are lower than the corresponding global values reported in UNSCEAR publications. The obtained results show that the averages of radiation hazard parameters for Assiut cement factory are lower than the acceptable level of 370 Bq kg -1 for radium equivalent Ra eq , 1 for level index Iγr, the external hazard index Hex ≤1 and 59 (nGy h -1 ) for absorbed dose rate. The manufacturing operation reduces the radiation hazard parameters. Cement does not pose a significant radiological hazard when used for construction of buildings.

  9. Determination of internal radiation dose due to intake of polonium 210 and lead 210 via smoking

    Al-Masri, M. S.; Kharita, M.H.; Nashawati, A.; Amin, Y.; Al-Akel, B.

    2004-12-01

    In this study, 18 kind of cigarettes and five kinds of molasses consumed by Syrians were collected and analyzed for radioactivity in order to estimate the internal radiation dose caused by 210 Po and 210 Pb intake. Polonium 210 and lead 210 concentrations varied between 4 and 16.4 m Bq/cigarette, while 210 Po distribution ratios in different parts of consumed cigarette were %12, %73, %1.6 in ash, smoke and filter, respectively. In addition, annual intake of 210 Po by a main smoker was varied between 4.4 and 18 Bq/year assuming that the main smoker breathes about 15% of the total 210 Po present in tobacco. Using the values of the annual intake, annual equivalent radiation dose caused by smoking has reached 178 μSv/year. Moreover, mean concentration of 210 Po in nonsmokers and smokers bloods has reached 130 and 97 mBq/l, respectively, while the mean value of 210 Po concentration was relatively higher and reached 176 and 155 mBq/l in smokers and non smoker bloods, respectively (Authors)

  10. On the problem of radiation damage due to diagnostic radiology of the chest

    Angerstein, W.

    1979-01-01

    The factors of risk for radiation-induced cancer given by UNSCEAR and ICRP are discussed. Under the uncertain assumption of the validity of these factors for diagnostic radiology the number of lung and breast cancers as well as of leukemias induced by mass chest radiography was estimated. It was found that for 30 chest X-rays per capita in the course of life there would be 180 lung cancers, 5 breast cancers and 27 leukemias in the GDR each year. These figures have been compared with the number of cases of lung tuberculosis and lung cancer detected annually ley mass chest radiography. However, no correlation could be found between diagnostic irradiations and detected cases of cancer. (author)

  11. The accidents due to ionizing radiations - the situation on a half century

    2007-02-01

    This report takes stock updated in 2006, serious accidents occurred in the four sectors in civil, industrial, medical and military. Its goal is to provide an explanatory and critical review of the most representative accident that caused serious harm to victims. The report analyses for each accident, and whenever reliable data exist, the reasons for its occurrence, consequences for victims and possibly to the environment, remedial actions that have been made and medical treatments when they were innovative. Using a combination of accidents with common features, the report offers key lessons to be learned from these tragic events. This report is intended for practitioners of radiation protection in general and does not target particular experts in any technical or medical specialty. (N.C.)

  12. Radiation load of population due to treatment of children neuroblastoma by 131I-MIBG

    Hermanska, J.; Zimak, J.; Kavan, P.; Dosel, P.

    1998-01-01

    This paper describes radiation protection aspects of 131 I-MIBG treatment of children neuroblastoma. It presents and discusses dose equivalents found for two population groups: (1) family members taking care of the child treated; (2) ambulance drivers transporting children to oxygenotherapy and the staff of the Institute Aviation Medicine where the hyperbaric chamber used for oxygenotherapy resides. The time needed for single trip is about 10 minutes. The minimum dose equivalents per transportation (two ways) was 0.1 μSv, the maximum 11.4 μSv. The total value in the year 1997 was 20.8 μSv. The presented results indicate that no danger of exceeding limits of dose equivalents in sense of (1) occurs under normal conditions. The shortest recommended time interval between two therapies is 6 months

  13. Real time monitoring automation of dose rate absorbed in air due to environmental gamma radiation

    Dominguez Ley, Orlando; Capote Ferrera, Eduardo; Carrazana Gonzalez, Jorge A.; Manzano de Armas, Jose F.; Alonso Abad, Dolores; Prendes Alonso, Miguel; Tomas Zerquera, Juan; Caveda Ramos, Celia A.; Kalber, Olof; Fabelo Bonet, Orlando; Montalvan Estrada, Adelmo; Cartas Aguila, Hector; Leyva Fernandez, Julio C.

    2005-01-01

    The Center of Radiation Protection and Hygiene (CPHR) as the head institution of the National Radiological Environmental Surveillance Network (RNVRA) has strengthened its detection and response capacity for a radiological emergency situation. The measurements of gamma dose rate at the main point of the RNVRA are obtained in real time and the CPHR receives the data coming from those points in a short time. To achieve the operability of the RNVRA it was necessary to complete the existent monitoring facilities using 4 automatic gamma probes, implementing in this way a real time measurement system. The software, GenitronProbe for obtaining the data automatically from the probe, Data Mail , for sending the data via e-mail, and Gamma Red , for receiving and processing the data in the head institution ,were developed

  14. Is there an increase in radiation exposure to the population due to diagnostic dental radiography. 2

    Spens, E.

    1983-01-01

    Orthodontic cases were examined to assess the superficial and genetically significant gonadal doses accumulated by the patients. During the period of examination, the radiodiagnostic services showed a retrograde tendency. At an average number of 6 radiographs per patient and terminated case the mean superficial dosis in the maxillofacial region amounted to 0.039 Sv, and the mean genetically significant gonadal dosis to 0.0063 mSv. Consequently, the stochastic-somatic radiation risk was greater than the genetic one. From the relatively low frequency of teleradiographs (2.3%) and on the basis of statistical data indications for the need for teleradiological working places in the ambulatory orthodontic care in the GDR are deduced. According to a trend analysis of the yearly frequency distribution of radiographic techniques used for the visualization of the tooth system an increased utilization of orthopantomography in orthodontics, is necessary

  15. Gamma radiation exposure of accompanying persons due to Lu-177 patients

    Kovan Bilal

    2015-01-01

    Full Text Available Neuroendocrine tumours (NET are cancers usually observed and arisen in the stomach, intestine, pancreas and breathing system. Recently, radionuclide therapy applications with Lu-177 peptide compound are rapidly growing; especially effective clinical results are obtained in the treatment of well-differentiated and metastatic NET. In this treatment, Lu-177-DOTA, a beta emitter radioisotope in the radiopharmaceutical form, is given to the patient by intravenous way. Lu-177 has also gamma rays apart from beta rays. Gamma rays have 175 keV average energy and these gamma rays should be under the control in terms of radiation protection. In this study, we measured the exposure dose from the Lu-177 patient.

  16. Energy-level splitting of multicharged ions due to interaction with own radiation field

    Gajnutdinov, R.Kh.; Kalashnikov, K.K.

    1991-01-01

    The overlapping of the energy levels of He-like uranium states with identical principal quantum numbers is investigated. Results are presented of a numerical calculation of the states produced as a result of mixing of the 2s 1/2 8p 1/2 and 2p 1/2 8p 1/2 states and of the respective spectral lines. It is shown that the interaction between the ion and its own radiation field splits each of the overlapping energy levels into several sublevels. The sublevels are isolated from each to other such an extent that interference effects become insignificant. The shapes of the spectral lines differ pronouncedly from the Lorentz shape and many of the line are anomaously narrow

  17. Patient radiation exposure dose evaluation of whole spine scanography due to exposure direction

    Kim, Jung Su; Seo, Deok Nam [Dept. of Bio-convergence Engineering, Graduate School of Korea University, Seoul (Korea, Republic of); Kwon, Soon Mu [Dept. of Radiologic Technology, Daegu Health College, Daegu (Korea, Republic of); Kim, Jung Min [Dept. of Radiological Science, Korea University, Seoul (Korea, Republic of)

    2015-04-15

    Whole spine scanography (WSS) is a radiological examination that exposes the whole body of the individual being examined to x-ray radiation. WSS is often repeated during the treatment period, which results in a much greater radiation exposure than that in routine x-ray examinations. The aims of the current study were to evaluate the patient dose of WSS using computer simulation, image magnification and angulation of phantom image using different patient position. We evaluated the effective dose(ED) of 23 consecutive patients (M : F = 13:10) who underwent WSS, based on the automatic image pasting method for multiple exposure digital radiography. The Anterior-Posterior position(AP) and Posterior-Anterior position( PA) projection EDs were evaluated based on the PC based Monte Carlo simulation. We measured spine transverse process distance and angulation using DICOM measurement. For all patient, the average ED was 0.069 mSv for AP position and 0.0361 mSv for PA position. AP position calculated double exposure then PA position. For male patient, the average ED was 0.089 mSv(AP) and 0.050 mSv(PA). For female patient, the average ED was 0.0431 mSv(AP) and 0.026 mSv(PA). The transverse process of PA spine image measured 5% higher than AP but angulation of transverse process was no significant differences. In clinical practice, just by change the patient position was conformed to reduce the ED of patient. Therefore we need to redefine of protocol for digital radiography such as WSS, whole spine scanography, effective dose, patient exposure dose, exposure direction, protocol optimization.

  18. The Thirty Years’ Results of Radiation Hygienic Monitoring of Tula Region territories contaminated due to the Chernobyl NPP accident

    V. V. Boldyreva

    2016-01-01

    Full Text Available Over 50% of Tula Region areas were contaminated after the Chernobyl NPP accident. The article provides the thirty years’ results of radiation hygienic monitoring of the Chernobyl accidental fallout - affected areas in Tula Region. The radiation situation is assessed at the initial accidental period and at the current stage. The initial levels of gamma - radiation dose intensity (up to 35 mcSv/hr are identified for the period of the “iodine” hazard along with the tabular data on the dose intensity relative stabilization by the beginning of August 1986 due to iodine-131 decay. The information is presented regarding iodine-131 tentative maximum permissible level exceedance in the dairy products of the two most contaminated regional areas - Plavskoye and Arsenievskoye. The article also provides the laboratory data on the total beta - activity in the foodstuffs in 1986-1987 and cesium-137 maximum permissible level exceedence in 1986. The radionuclide maximum permissible level exceedances in foodstuffs were registered only in 1986 due to the plants surface contamination whereas in the forest mushrooms those exceedances were repeatedly found until 2004. The black earths and grey forest soils had a benign impact upon the intensity of the radionuclide transfer into plants which resulted in the formation of internal radiation doses.At the current stage, the content of cesium-137 and strontium- 90 in the foodstuffs can only be quantified by a radiochemical method. The table covers all the districts within the boundaries of radiation contaminated zones. The radiochemical studies indicate the main dose - forming products. The article contains the table of internal and external radiation doses of the population in Plavsk town over 1986-1990 and displays the factors impacting population’s internal and external exposure. The Chernobyl - affected exposure dose of the population is mostly attributed to the external radiation and, for over twenty years, it

  19. Simulation studies to determine the gamma radiation dose due to natural radioactivity in construction materials in dwellings

    Shetty, P.G.; Chougaonkar, M.P.; Mayya, Y.S.; Puranik, V.D.

    2008-01-01

    Gamma radiation dose is imparted to the living due to the natural radionuclides present in the environmental materials, including the building materials used for construction of dwellings. The radionuclides responsible for natural radiation dose are the primordial radionuclides of 232 Th, 238 U series and the 40 K. These nuclides together with their daughters give rise to external gamma ray dose as well as the inhalation doses arising from the short-lived radon/thoron gases and their progenies that are exhaled from the walls of the construction materials. The radioactivity inside a room and the radiation dose caused by it mainly depends on the concentration of the above mentioned radionuclides in the building materials and type/properties like thickness, density etc. of the material used for construction. A computational model for a standard house (without windows and door) has been designed using Monte Carlo N-particle code (MCNP). The code works on probability theory. The present paper discusses the individual contribution of doses from 40 K, uranium and thorium series. Further variation in the gamma doses due to different building materials and densities are also discussed. (author)

  20. Assessment of radiation doses due to normal operation, incidents and accidents of the final disposal facility

    Rossi, J.; Raiko, H.; Suolanen, V.; Ilvonen, M.

    1999-03-01

    Radiation doses for workers of the encapsulation and disposal facility and for inhabitants in the environment caused by the facility during its operation were considered. The study covers both the normal operation of the plant and some hypothetical incidents and accidents. Occupational radiation doses inside the plant during normal operation are based on the design basis, assuming that highest permitted dose levels are prevailing in control rooms during fuel transfer and encapsulation processes. Release through the ventilation stack is assumed to be filtered both in normal operation and in hypothetical incident and accident cases. Calculation of the offsite doses from normal operation is based on the hypothesis that one fuel pin per 100 fuel bundles for all batches of spent fuel transported to the encapsulation facility is leaking. The release magnitude in incidents and accidents is based on the event chains, which lead to loss of fuel pin tightness followed by a discharge of radionuclides into the handling chamber and to some degree through the ventilation stack into atmosphere. The weather data measured at the Olkiluoto meteorological mast was employed for calculating of offsite doses. Therefore doses could be calculated in a large amount of different dispersion conditions, the statistical frequencies of which have, been measured. Finally doses were combined into cumulative distributions, from which a dose value representing the 99.5 % confidence level, is presented. The dose values represent the exposure of a critical group, which is assumed to live at the distance of 200 meters from the encapsulation and disposal plant and thus it will receive the largest doses in most dispersion conditions. Exposure pathways considered were: cloudsnine, inhalation, groundshine and nutrition (milk of cow, meat of cow, green vegetables, grain and root vegetables). Nordic seasonal variation is included in ingestion dose models. The results obtained indicate that offsite doses

  1. Atlas based brain volumetry: How to distinguish regional volume changes due to biological or physiological effects from inherent noise of the methodology.

    Opfer, Roland; Suppa, Per; Kepp, Timo; Spies, Lothar; Schippling, Sven; Huppertz, Hans-Jürgen

    2016-05-01

    Fully-automated regional brain volumetry based on structural magnetic resonance imaging (MRI) plays an important role in quantitative neuroimaging. In clinical trials as well as in clinical routine multiple MRIs of individual patients at different time points need to be assessed longitudinally. Measures of inter- and intrascanner variability are crucial to understand the intrinsic variability of the method and to distinguish volume changes due to biological or physiological effects from inherent noise of the methodology. To measure regional brain volumes an atlas based volumetry (ABV) approach was deployed using a highly elastic registration framework and an anatomical atlas in a well-defined template space. We assessed inter- and intrascanner variability of the method in 51 cognitively normal subjects and 27 Alzheimer dementia (AD) patients from the Alzheimer's Disease Neuroimaging Initiative by studying volumetric results of repeated scans for 17 compartments and brain regions. Median percentage volume differences of scan-rescans from the same scanner ranged from 0.24% (whole brain parenchyma in healthy subjects) to 1.73% (occipital lobe white matter in AD), with generally higher differences in AD patients as compared to normal subjects (e.g., 1.01% vs. 0.78% for the hippocampus). Minimum percentage volume differences detectable with an error probability of 5% were in the one-digit percentage range for almost all structures investigated, with most of them being below 5%. Intrascanner variability was independent of magnetic field strength. The median interscanner variability was up to ten times higher than the intrascanner variability. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Cancer mortality risk of nuclear power workers due to the exposure of ionising radiation in Germany

    Fehringer, F.; Seitz, G.; Hammer, G.P.; Blettner, M.

    2006-01-01

    A cohort study of German nuclear power workers was set up to investigate overall and cancer mortality risk related to a chronic exposure to ionising radiation of low-level dose. The German study was performed as a part of an international study carried out by the International Agency for Research on Cancer (IARC), Lyon. First results of the international study have been published recently [1]. German data are not yet included in this analysis. The German cohort consists of 4844 employees from 10 nuclear power plants. All persons who worked in these nuclear power plants in 1991 or started employment between 1991 und 1997 are included (except for employees of one plant, whose observation period started in 1992). These persons accumulated about 31,000 person years. Overall, 68 deaths were observed in the observation period between 1.1.1991-31.12.1997. Standardized mortality ratios (SMR) were computed for all causes of death, all cancers, cardiovascular diseases, external causes, and all other causes. Overall, a strong healthy worker effect was observed (SMR=0.52 [95% CI: 0.41;0.67]). No increase in total cancer mortality was seen (SMR=0.85 [95% CI: 0.53;1.30]). However, numbers are too small for stable risk estimates and further effort is under way to complete the cohort in terms of power plants and to extend the follow-up until 2005. (authors)

  3. Exacerbation of radiation induced meningioma due to hemorrhage after cerebral angiography. A case report

    Yamaguchi, Shinya; Matsuo, Yoshihiro; Uesaka, Toshio; Matsukado, Koichiro; Suzuki, Satoshi O.; Iwaki, Toru

    2011-01-01

    We report the case of a 34-year-old woman who exhibited acute deterioration in her condition after cerebral angiography for evaluation of a large meningioma. She had undergone surgery and irradiation for a glioma in the right occipital lobe 23 years before this episode. She experienced incapacity at work. On CT and MRI, a large meningioma was detected on the left frontal convexity; this tumor was thought to be radiation-induced. Cerebral angiography was performed to assess the vascularization of the tumor. Her condition began to deteriorate 2.5 h after the cerebral angiography. CT revealed an increase in the mass of the tumor, and a high density area in the tumor. We immediately removed the tumor. Histopathological examinationrevealed the tumor to be a meningothelial meningioma. New hemorrhagic foci were identified in the tumor. In addition, macrophages containing hemosiderin were detected, and some of the tumor vessels exhibited hyaline degeneration. We suspected that angiography triggered bleeding in the meningioma, which was already predisposed to hemorrhage. (author)

  4. Cancer mortality risk of nuclear power workers due to the exposure of ionising radiation in Germany

    Fehringer, F.; Seitz, G. [Berufsgenossenschaft der Feinmechanik und Elektrotechnik, Koln (Germany); Hammer, G.P.; Blettner, M. [Johannes Gutenberg-Universitat Mainz, Institut fur Medizinische Biometrie, Epidemiologie und Informatik des Klinikums (Germany)

    2006-07-01

    A cohort study of German nuclear power workers was set up to investigate overall and cancer mortality risk related to a chronic exposure to ionising radiation of low-level dose. The German study was performed as a part of an international study carried out by the International Agency for Research on Cancer (IARC), Lyon. First results of the international study have been published recently [1]. German data are not yet included in this analysis. The German cohort consists of 4844 employees from 10 nuclear power plants. All persons who worked in these nuclear power plants in 1991 or started employment between 1991 und 1997 are included (except for employees of one plant, whose observation period started in 1992). These persons accumulated about 31,000 person years. Overall, 68 deaths were observed in the observation period between 1.1.1991-31.12.1997. Standardized mortality ratios (SMR) were computed for all causes of death, all cancers, cardiovascular diseases, external causes, and all other causes. Overall, a strong healthy worker effect was observed (SMR=0.52 [95% CI: 0.41;0.67]). No increase in total cancer mortality was seen (SMR=0.85 [95% CI: 0.53;1.30]). However, numbers are too small for stable risk estimates and further effort is under way to complete the cohort in terms of power plants and to extend the follow-up until 2005. (authors)

  5. Most cancer in firefighters is due to radio-frequency radiation exposure not inhaled carcinogens.

    Milham, S

    2009-11-01

    Recent reviews and reports of cancer incidence and mortality in firefighters conclude that they are at an increased risk of a number of cancers. These include leukemia, multiple myeloma, non-Hodgkin's lymphoma, male breast cancer, malignant melanoma, and cancers of the brain, stomach, colon, rectum, prostate, urinary bladder, testes, and thyroid. Firefighters are exposed to a long list of recognized or probable carcinogens in combustion products and the presumed route of exposure to these carcinogens is by inhalation. Curiously, respiratory system cancers and diseases are usually not increased in firefighters as they are in workers exposed to known inhaled carcinogens. The list of cancers with increased risk in firefighters strongly overlaps the list of cancers at increased risk in workers exposed to electromagnetic fields (EMF) and radiofrequency radiation (RFR). Firefighters have increased exposure to RFR in the course of their work, from the mobile two-way radio communications devices which they routinely use while fighting fires, and at times from firehouse and fire vehicle radio transmitters. I suggest that some of the increased cancer risk in firefighters is caused by RFR exposure, and is therefore preventable. The precautionary principle should be applied to reduce the risk of cancer in firefighters, and workman's compensation rules will necessarily need to be modified.

  6. Nonlinear radiated MHD flow of nanoliquids due to a rotating disk with irregular heat source and heat flux condition

    Mahanthesh, B.; Gireesha, B. J.; Shehzad, S. A.; Rauf, A.; Kumar, P. B. Sampath

    2018-05-01

    This research is made to visualize the nonlinear radiated flow of hydromagnetic nano-fluid induced due to rotation of the disk. The considered nano-fluid is a mixture of water and Ti6Al4V or AA7072 nano-particles. The various shapes of nanoparticles like lamina, column, sphere, tetrahedron and hexahedron are chosen in the analysis. The irregular heat source and nonlinear radiative terms are accounted in the law of energy. We used the heat flux condition instead of constant surface temperature condition. Heat flux condition is more relativistic and according to physical nature of the problem. The problem is made dimensionless with the help of suitable similarity constraints. The Runge-Kutta-Fehlberg scheme is adopted to find the numerical solutions of governing nonlinear ordinary differential systems. The solutions are plotted by considering the various values of emerging physical constraints. The effects of various shapes of nanoparticles are drawn and discussed.

  7. Thermophoretic diffusion and nonlinear radiative heat transfer due to a contracting cylinder in a nanofluid with generalized slip condition

    Z. Abbas

    Full Text Available An analysis is carried out to study the generalized slip condition and MHD flow of a nanofluid due to a contracting cylinder in the presence of non-linear radiative heat transfer using Buongiorno’s model. The Navier-Stokes along with energy and nanoparticle concentration equations is transformed to highly nonlinear ordinary differential equations using similarity transformations. These similar differential equations are then solved numerically by employing a shooting technique with Runge–Kutta–Fehlberg method. Dual solutions exist for a particular range of the unsteadiness parameter. The physical influence of the several important fluid parameters on the flow velocity, temperature and nanoparticle volume fraction is discussed and shown through graphs and table in detail. The present study indicates that as increase of Brownian motion parameter and slip velocity is to decrease the nanoparticle volume fraction. Keywords: Nanofluid, Contracting cylinder, Nonlinear thermal radiation, Generalized slip condition, Numerical solution

  8. Change of the natural radiation exposure due to agriculture and industrial activities in a high natural radioactivity area from Brazil

    Silva Amaral, E.C. da.

    1992-01-01

    The Pocos de Caldas Plateau, Minas Gerais State one of the biggest alkaline intrusions in the world. This study has shown the expected value for the mean annual radiation exposure due to the agricultural activities ranges from 6 up to 14 mSv/a depending on the age and living habits of the population group. The inhalation exposure of radon, thoron and their progenies represents the largest radiological health hazard (70-90%); this is followed by the external gamma irradiation from soil (10-25%). Ingestion of natural radionuclides with local food is only of minor radiological consequence. It was found that the lethal cancer risk might increase by 4% for a person born at the plateau, living and working there for the rest of her life. For the remote population the consumption the consumption of food products exported from the plateau leads to an expected value for the collective dose of 19 man Sv/a. This corresponding nominally to the small calculated number of 1 additional case of cancer per year. Therefore the main radiation impact of the agricultural activities are not the increased concentrations of natural radionuclides in food products but the fact that they are produced there with human labor and thus increasing the radiation exposure to a large number of farm workers and their families that move for occupational reasons to that region. The radiation exposure due to the mining and milling activities is, in spite of the significant increase of radionuclide activity concentrations in river waters, only of the order of 0.3 mSv/a. However as a recognized industrial source the ICRP dose limitation system has to be applied. Under this aspect the exposure calculated here, 0.3 mSv/a, should be considered as acceptable. (author). 93 refs, 16 figs, 58 tabs

  9. SU-E-T-279: Dose Enhancement Effect Due to Cerium Oxide Nanoparticles Employed as Radiation Protectants

    Ouyang, Z; Altundal, Y; Sajo, E [Univ Massachusetts Lowell, Lowell, MA (United States); Ngwa, W [Univ Massachusetts Lowell, Lowell, MA (United States); Brigham and Women’s Hospital, Dana Farber Cancer Institute, Harvard Medical, Boston, MA (United States)

    2015-06-15

    Purpose: The goal of radiotherapy is to maximize radiation dose to diseased cells while minimizing radiation damage to normal tissues. In order to minimize damage to normal tissues, cerium oxide nanoparticles (nanoceria) are currently considered as a radioprotectant. However, some studies have reported concerns that nanoceria can also lead to radiotherapy dose enhancement due to the high atomic number of cerium, especially when used in conjunction with kV energy and brachytherapy sources. In this study, this concern is investigated to determine if the concentrations of nanoceria employed in in-vivo studies to confer radioprotection can engender a significant dose enhancement. Methods: Radiation with energies ranging from 50kVp to 140kVp is investigated in this work along with brachytherapy sources Pd-103 and I-125. A previously established theoretical model is used to calculate the dose enhancement factor (DEF). In this model, each cell is assumed to be a voxel of size (10 µm, 10 µm, 10 µm) with nanoceria homogeneously distributed among them. Electron energy loss formula of Cole is used to calculate energy (and hence dose) deposited by photoelectrons and Auger electrons in each tissue voxel due to irradiation of nanoceria. The DEF is defined as the ratio of the dose with and without nanoparticles. Results: DEF calculation results are smaller than 1.02 with dosages of nanoceria smaller than 0.645 mg/g, which is shown to be sufficiently protective by some previous in-vitro and in-vivo experiments. The brachytherapy sources show higher DEF’s than kVp radiations. DEF peaks are consistent with K shell and L shell energies of cerium, 40 keV and 6 keV, respectively. Conclusion: The results show that for sufficiently radioprotective concentrations of nanoceria, there will be minimal DEF when used in conjunction with clinically applicable kV energy radiotherapy sources or brachytherapy sources.

  10. Development of a Method to Assess the Radiation Dose due to Internal Exposure to Short-lived Radioactive Materials

    Benmaman, D.; Koch, J.; Ribak, J.

    2014-01-01

    Work with radioactive materials requires monitoring of the employees' exposure to ionizing radiation. Employees may be exposed to radiation from internal and/or external exposure. Control of external exposure is mostly conducted through personal radiation dosimeters provided to employees. Control of internal exposure can be performed by measuring the concentration of radioactive substances excreted in urine or through whole-body counting in which the entire body or target organs are scanned with a sensitive detector system (1). According to the regulations in Israel an employee that may be internally exposed must undergo an exposure control at least once every three months. The idea lying behind the control of internal exposure by urine testing is that if radioactive material has penetrated into the employee body, it can be detected even if the test is performed once every three months. A model was fitted for each element describing its dispersion in the body and its excretion therefrom (2). By means of this model, one can estimate the activity that entered the body and calculate the resulting radiation dose to which the worker was exposed. There is a problem to implement this method when it comes to short-lived radioactive materials, for which it is very likely that the material that penetrated into the body has decayed and cannot be detected by testing once every three months. As a result, workers with short-lived radioactive materials are presently not monitored for internal exposure, in contradiction to the requirements of the Safety at Work Regulations. The purpose of the study is to develop an alternative method to assess the amount of radioactive material absorbed in the body and the resulting radiation dose due to internal exposure of workers to short-lived radioactive materials

  11. Study of time variation of terrestrial gamma radiation due to depth distribution of soil moisture content

    Yoshioka, Katsuhiro

    1994-01-01

    An empirical equation was deduced from studies of time variations of terrestrial gamma exposure rate and soil moisture content with depth distribution in the surface layer. It was definitely suggested that the variation of terrestrial gamma exposure rate is most strongly influenced by the change of soil moisture content at 5 cm depth. The seasonal variation with a relative maximum in early autumn and a relative minimum in early spring was clearly obtained in the consequence of long time measurements of terrestrial gamma exposure rate and degree of soil dryness. The diurnal change and phase difference due to the effect of depth were also obtained in the dynamic characteristics of soil moisture content at 3 different depths. From the comparison between measured terrestrial gamma exposure rate and that evaluated from soil moisture content using the empirical equation, it was seen that seasonal variations of the both agreed fairly well as a whole. (author)

  12. High efficiency detection technique on quantum action due to radiation excitation

    Yamazaki, Tetsuo; Kobayashi, Naoto; Sakamoto, Isao; Hayashi, Nobuyuki; Okubo, Masataka

    1999-01-01

    For a key point to obtain high energy resolution, three items such as long life of quasi particle, short tunneling time, and low leakage current can be shown. Then, in order to establish high energy resolution by filling these three items, a research on Nb/Al/AlO x /Al/Nb superconducting tunnel junction was proceeded. In 1997 fiscal year, elucidation on phonon relaxation phenomenon in Nb crystal grain boundary was conducted. On energy resolution, by realizing increase of quasi particle life and upgrading if junction quality, 70 to 90 eV which is higher than that of semiconductor detector could be established. After then, to remove the phonon relaxation at crystal grain boundary, it was necessary to practise high qualification of absorber such as improvement of Nb film micro structure and single crystallization, and enforcement of quasi particle trapping due to superconductor except Nb/Al. (G.K.)

  13. A case of radiation enteritis with intestinal obstruction due to incarceration of foreign body

    Tajima, Hidehiro; Isobe, Tsugumasa; Sakuma, Hiroshi; Imahori, Tsutomu; Naka, Fumihiko; Ueda, Hiroshi; Ida, Masahiro; Matsubara, Fujitsugu [Tatsunokuchi Houju Memorial Hospital, Kanazawa (Japan)

    1996-08-01

    A 66-year-old woman was seen at the hospital because of an abdominal pain and vomiting. There were previous histories of undergoing ileocecal resection 30 years and total hysterectomy with irradiation for uterine cancer 29 years earlier. Abdominal CT showed a shadow of foreign body, and barium enema revealed a filling defect in the ileum and stenosis at the anastomosis. In addition to these findings the patient deposed that she had ingested a seed of `ume` (Japanese apricot). The patient was diagnosed as intestinal obstruction due to the foreign body and underwent an operation. The postoperative course is good, however, this patient has many other disorders probable resulting from irradiation, such as stenosis of ureter, cutaneous pigmentation and tumor, adenoma of the rectum. Long term and periodic follow-up is important for the patient entertaining possible occurrence of other disorders and second cancer. (author)

  14. A case of radiation enteritis with intestinal obstruction due to incarceration of foreign body

    Tajima, Hidehiro; Isobe, Tsugumasa; Sakuma, Hiroshi; Imahori, Tsutomu; Naka, Fumihiko; Ueda, Hiroshi; Ida, Masahiro; Matsubara, Fujitsugu

    1996-01-01

    A 66-year-old woman was seen at the hospital because of an abdominal pain and vomiting. There were previous histories of undergoing ileocecal resection 30 years and total hysterectomy with irradiation for uterine cancer 29 years earlier. Abdominal CT showed a shadow of foreign body, and barium enema revealed a filling defect in the ileum and stenosis at the anastomosis. In addition to these findings the patient deposed that she had ingested a seed of 'ume' (Japanese apricot). The patient was diagnosed as intestinal obstruction due to the foreign body and underwent an operation. The postoperative course is good, however, this patient has many other disorders probable resulting from irradiation, such as stenosis of ureter, cutaneous pigmentation and tumor, adenoma of the rectum. Long term and periodic follow-up is important for the patient entertaining possible occurrence of other disorders and second cancer. (author)

  15. Calculation of the annual radiation dose to the population in the vicinity of nuclear installations due to liquid effluents

    Gans, I.

    1991-01-01

    Since 1974, assessments of radiation exposure due to the emission of radioactive substances with liquid effluents have been done by the Institut fuer Wasser-, Boden- und Lufhygiene of the Federal Health Office and data have bee published in the annual reports in the series 'Umweltradioaktivitaet und Strahlenbelastung'. The paper explaines the radioecological models of ABG and AVV as far as they relate to the wastewater pathway, as well as the required modifications. Individual aspects of computation are explained referring to the dose calculations for 1989. (orig./DG) [de

  16. Dosimetric evaluation of scattered and attenuated radiation due to dental restorations in head and neck radiotherapy

    Mona Azizi

    2018-01-01

    Full Text Available In radiotherapy of head and neck cancer, the presence of high density materials modifies photon dose distribution near these high density materials during treatment. The aim of this study is to calculate the backscatter and attenuation effects of a healthy tooth, Amalgam, Ni-Cr alloy and Ceramco on the normal tissues before and after these materials irradiated by 6 and 15 MV photon beams, respectively. All measurements were carried out in a water phantom with dimension of 50 × 50 × 50 cm3with an ionization chamber detector. Two points before and four points after the dental sample were considered to score the photon dose. The depth dose on the central beam axis was explored in a water phantom for source to surface distance (SSD of 100 cm in a 10 × 10 cm2 field size. The percentage dose change was obtained relative to the dose in water versus depth of water, tooth, Amalgam, Ni-Cr alloy and Ceramco for the photon beams. The absolute dose (cGy was measured by prescription of 100 cGy dose in the water phantom at depth of 2.0 and 3.1 cm for 6 and 15 MV photons, respectively. At depth of 0.6 cm, the maximum percentage dose increase was observed with values of 6.99% and 9.43%for Ni-Cr and lowest percentage dose increase of 1.49% and 2.63% are related to the healthy tooth in 6 and 15 MV photon beams, respectively. The maximum absolute dose of 95.58 cGy and 93.64 cGy were observed at depth of 0.6 cm in presence of Ni-Cr alloy for 6 and 15 MV photon beams, respectively. The presence of dental restorations can cause backscattering dose during head and neck radiation therapy. Introduction of compositions and electron density of high density materials can improve the accuracy of dosimetric calculations in treatment planning systems to deliver the relevant dose to target organ and reduce the backscattering dose in healthy tissues in the surrounding of tooth.

  17. Study of degradation on polypropylene accessories used in radiotherapy services due to interaction with gamma radiation

    Neto, Antonio R.; Azevedo, Elaine C.; Soboll, Danyel S.

    2013-01-01

    Polypropylene is a polymer used in radiotherapy services as immobilization parts and masks due to their thermoplastic properties that allow specific formats of construction and has a low cost production. However this material can present degradation over time and may hinder basic procedures as cleaning between uses of this accessory. In this study, samples of PP (polypropylene) were evaluated before and after irradiation with doses from 5 kGy to 25 kGy by infrared absorption spectrometry and contact angle analysis. The infrared spectrum showed material degradation by analyzing the peaks corresponding to the chemical bonds C-H, C-H2 and C-H3 which increased absorption to all doses when compared with the non-irradiated spectrum. The contact angle demonstrated that on the PP surface the contact angle decreased in all comparisons among samples irradiated and non-irradiated, showing a hydrophilic behavior. However, starting at 20 kGy it was observed less variation of angles when compared with lower doses. Irradiated at 25 kGy the material presented a contact angle almost identical to the non-irradiated material. (author)

  18. Radiation exposure of the Italian population due to medical diagnostic examinations in 1975

    Benassai, S.; Curatolo, M.; Dobici, F.; Indovina, P.L.; Pugliani, L.; Salvadori, P.

    1977-01-01

    The genetically significant dose received by the Italian population in 1975 due to the diagnostic X-ray examinations and radiopharmaceuticals was investigated and the results are presented. Concerning the diagnostic X-ray examinations the data were obtained by a representative sample and extrapolated over the whole population with reference to the over-all X-ray film consumption. From the reported data it can be concluded that about 50% of population was subjected to X-ray examinations and the genetically significant dose amounts to about 30 mrem. With reference to diagnostic use of radiopharmaceuticals the number of collected data was so large to be considered as representative of the situation. From the collected data it can be concluded that about 10% of population was subjected to these examinations and that the genetically significant dose is less than 2 mrem. Both for diagnostic X-ray examinations and use of radiopharmaceuticals results are here presented for the distribution of different uses and examinations. The genetically significant dose to which the Italian population was exposed in 1975 can be said to be of the order of 30 mrem. In view of lowering this dose some indications are presented with reference both to the legislative and technical measures

  19. A case of entero-cutaneous and vesico-enteral fistula due to radiation for uterine cervical carcinoma

    Iwakawa, Kazuhide; Kadota, Takeshi; Kobayashi, Nobuaki; Ohnishi, Goro.

    1994-01-01

    Late-phase complications of the intestinal and the urinary tracts due to radiation therapy are very difficult to manage, and ensuing fistulation sometimes necessitates surgrey. We report excellent surgical results for a fistula incuded by radiation therapy in a 61-years-old woman. There were previous histories of receiving combined surgical and radiation (up to 10,000 rad) therapy for a uterine cervical carcinoma at another hospital in 1990, and undergoing several surgical treatments for the consequenct vesico-enteral and vesico-colic fistulas. In January, 1993, the patient was admitted to the department of urology of this hospital because of an abdominal pain, and was transferred to the department under a diagnosis of entero-cutaneous and vesico-enteral fistulas. After local sump suction and skin care, resection of the fistula and involved small intestine conserving the urinary tract was performed, and the omentum was transferred to the resected space. Cholecystectomy was carried out for cholelithiasis. Histological studies revealed atrophy in the mucosal layer and edema in the submucosal layer. Her postoperative course has been satisfactory without any signs of fistulation as of one year after the operation. (author)

  20. A case of entero-cutaneous and vesico-enteral fistula due to radiation for uterine cervical carcinoma

    Iwakawa, Kazuhide; Kadota, Takeshi; Kobayashi, Nobuaki [Ehime Univ., Shigenobu (Japan). School of Medicine; Ohnishi, Goro

    1994-11-01

    Late-phase complications of the intestinal and the urinary tracts due to radiation therapy are very difficult to manage, and ensuing fistulation sometimes necessitates surgrey. We report excellent surgical results for a fistula incuded by radiation therapy in a 61-years-old woman. There were previous histories of receiving combined surgical and radiation (up to 10,000 rad) therapy for a uterine cervical carcinoma at another hospital in 1990, and undergoing several surgical treatments for the consequenct vesico-enteral and vesico-colic fistulas. In January, 1993, the patient was admitted to the department of urology of this hospital because of an abdominal pain, and was transferred to the department under a diagnosis of entero-cutaneous and vesico-enteral fistulas. After local sump suction and skin care, resection of the fistula and involved small intestine conserving the urinary tract was performed, and the omentum was transferred to the resected space. Cholecystectomy was carried out for cholelithiasis. Histological studies revealed atrophy in the mucosal layer and edema in the submucosal layer. Her postoperative course has been satisfactory without any signs of fistulation as of one year after the operation. (author).

  1. Radiation dose estimation from foods due to the accident of TEPCO Fukushima Daiichi Nuclear Power Station

    Yamaguchi, Ichiro

    2012-01-01

    Explained are the purpose of dose assessment, its methods, actual radionuclide levels in food, amounts of food intake, dose estimated hitherto, dose in the future, dose estimated by total food studies, and problems of assessing the dose from food, all of which Tokyo Electric Power Company (TEPCO) Power Station Accident has raised. Dose derived from food can be estimated by the radioactivity measured in each food material and in its combined amounts or in actually cooked food. Amounts of radioactive materials ingested in the body can be measured externally or by bioassay. Japan MHLW published levels of radioactivity in vegetables', fruits, marine products and meats from Mar. 2011, of which time course pattern has been found different each other within and between month(s). Dose due to early exposure in the Accident can be estimated by the radioactivity levels above and data concerning the amounts of food intake summarized by National Institute of Health and Nutrition in 2010 and other institutions. For instance, the thyroid tissue equivalent dose by I-131 in a 1 year old child is estimated to be 1.1-5 mSv depending on the assumed data for calculation, in the first month after the Accident when ICRP tissue equivalent dose coefficient 3.7 x 10-6 Sv/Bq is used. In the future (later than Apr. 2012), new standard limits of radiocesium levels in milk/its products and foods for infant and in other general foods are to be defined 50 and 100 Bq/kg, respectively. The distribution of committed effective doses by radiocesium (mSv/y food intake) are presented as an instance, where it is estimated by 1 million stochastic simulations using 2 covariates of Cs-134, -137 levels (as representative nuclides under regulation) in food and of daily food intake. In dose prediction, conjecturing the behavior of environmental radionuclides and the time of resume of primary industries would be necessary. (T.T.)

  2. Sensitivity/uncertainty analysis for free-in-air tissue kerma due to initial radiation at Hiroshima and Nagasaki

    Lillie, R.A.; Broadhead, B.L.; Pace, J.V. III

    1988-01-01

    Uncertainty estimates and cross correlations by range/survivor have been calculated for the Hiroshima and Nagasaki free-in-air (FIA) tissue kerma obtained from two-dimensional air/ground transport calculations. The uncertainties due to modeling parameter and basic nuclear transport data uncertainties were calculated for 700-, 1000-, and 1500-m ground ranges. Only the FIA tissue kerma due to initial radiation was treated in the analysis; the uncertainties associated with terrain and building shielding and phantom attenuation were not considered in this study. Uncertainties of --20% were obtained for the prompt neutron and secondary gamma kerma and 30% for the prompt gamma kerma at both cities. The uncertainties on the total prompt kerma at Hiroshima and Nagasaki are --18 and 15%, respectively. The estimated uncertainties vary only slightly by ground range and are fairly highly correlated. The total prompt kerma uncertainties are dominated by the secondary gamma uncertainties, which in turn are dominated by the modeling parameter uncertainties, particularly those associated with the weapon yield and radiation sources

  3. Characterization of Nafion ionomer and its change due to X radiation

    Almeida, Selma Helena de

    1996-01-01

    In this study, first the characterization of Nafion-117 membranes in the acid form (Nafion-H) and in the salt forms (Na + , K + , Rb + and Cs + ) was performed. In another step, the X-ray effects on membranes (Nafion-H and Nafion-Na) were investigated. The samples were irradiated with X-ray, at 160 kGy/h, with 80-1280 kGy dosages. The characterization of samples (irradiated and unirradiated samples) was performed by X-ray diffractometry, vibrational spectroscopy (photoacoustic in infrared region and Raman scattering), electronic absorption spectroscopy (UV/Vis), electronic paramagnetic resonance spectroscopy (EPR) and thermal analysis (TG and DCS). The studies showed that the membranes submitted to high temperature or to hydration structural changes, as evidence by IR and UV/Vis spectra and DSC curves. This behavior can be assigned to the reorganization of the clusters, resulting in redistribution of the ions and reorientation of the polymers. UV/Vis spectra and DSC curves indicates that the conformational changes induced by temperature and hydration effect continue to occur slowly in the membrane due to relaxation of the polymer. TG analysis indicated that the thermal decomposition mechanism by Nafion-H is different from the mechanism by Nafion-Na. Nafion-H membranes degraded in at least three stages, while Nafion-Na membranes, which showed higher thermal stability than Nafion-H, degraded in only one stage. For irradiation dose higher than 320 kGy, the samples became brittle, which enhanced with increasing doses. This behavior indicates that the predominant effect was the chain scission. The results obtained by different technique showed that the main effects of X-rays on Nafion membranes are the following: decrease in the mechanical properties, peroxy radical production, formation of unsaturated species (C=C and C=O), scissions in the C-O and C-S bonds and SO 2 production. The Nafion-Na membrane showed higher thermal stability and higher resistance to X

  4. internal radiation dose assessment due to ionizing radio contaminants in some local foodstuffs

    AbdElKader, F.M.

    1996-01-01

    Over the last 30 years, radioactivity has been monitored in foodstuffs in Egypt. The present work deals with the radioactivity monitored during two years (1990 - 1992) at eight major Egyptian governorates. Sampled food items were selected to cover most foodstuffs eaten by egyptian population according to their habits. The daily food consumption by egyptian population and the constituents of such consumption were estimated according to published international data and knowledge of the different feeding habits of the egyptians. About 1200 samples were collected from the markets of the main city of each governorate and prepared for counting according to the egyptian kitchen habits. The counting systems used in determination and indentification of radionuclides were : a 3 inch HPGe detector attached to 800 channel MCA and PC and a 3 inch phoswich detector attached to an anticoincidence circuit for low beta / gamma counting. The gamma spectroscopy system was calibrated using isotopic solution mixture while the low beta counting system was calibrated using H CI. Counting time for the first system was 20 - 72 hours and for the second system was half to one hour. The main radionuclides identified in foodstuffs were Cs - 137 and K - 40 . The radioactivity concentration of Cs - 137 was found to be in the range between 1.0 Bq / Kg for macaroni and 3.5 Bq / Kg for nile beans. The K - 40 concentration range between 19 Bq / Kg for macaroni to 363 Bq / Kg for nile beans. The population weighted values in case of Cs - 137 was found as 3.56 Bq /d and for K - 40 was 188 Bq /d. The resulted effective dose due to food intake was found be 16 . 4 U Sv /a for Cs-137 and 354 μSv / a for K -40 . This value for Cs - 137 is found in the exemption limit while that of K -40 is twice the published value. This may depend on the egyptian feeding habit which depends mainly on wheat (bread) and nile beans which are very rich in potassium.The resulted collective dose was found to be : 21323 person

  5. Reduction of the performance of a noise screen due to screen-induced wind-speed gradients: numerical computations and wind-tunnel experiments

    Salomons, E.M.

    1999-01-01

    Downwind sound propagation over a noise screen is investigated by numerical computations and scale model experiments in a wind tunnel. For the computations, the parabolic equation method is used, with a range-dependent sound-speed profile based on wind-speed profiles measured in the wind tunnel and

  6. Chemical and climatic drivers of radiative forcing due to changes in stratospheric and tropospheric ozone over the 21st century

    Banerjee, Antara; Maycock, Amanda C.; Pyle, John A.

    2018-02-01

    The ozone radiative forcings (RFs) resulting from projected changes in climate, ozone-depleting substances (ODSs), non-methane ozone precursor emissions and methane between the years 2000 and 2100 are calculated using simulations from the UM-UKCA chemistry-climate model (UK Met Office's Unified Model containing the United Kingdom Chemistry and Aerosols sub-model). Projected measures to improve air-quality through reductions in non-methane tropospheric ozone precursor emissions present a co-benefit for climate, with a net global mean ozone RF of -0.09 W m-2. This is opposed by a positive ozone RF of 0.05 W m-2 due to future decreases in ODSs, which is driven by an increase in tropospheric ozone through stratosphere-to-troposphere transport of air containing higher ozone amounts. An increase in methane abundance by more than a factor of 2 (as projected by the RCP8.5 scenario) is found to drive an ozone RF of 0.18 W m-2, which would greatly outweigh the climate benefits of non-methane tropospheric ozone precursor reductions. A small fraction (˜ 15 %) of the ozone RF due to the projected increase in methane results from increases in stratospheric ozone. The sign of the ozone RF due to future changes in climate (including the radiative effects of greenhouse gases, sea surface temperatures and sea ice changes) is shown to be dependent on the greenhouse gas emissions pathway, with a positive RF (0.05 W m-2) for RCP4.5 and a negative RF (-0.07 W m-2) for the RCP8.5 scenario. This dependence arises mainly from differences in the contribution to RF from stratospheric ozone changes. Considering the increases in tropopause height under climate change causes only small differences (≤ |0.02| W m-2) for the stratospheric, tropospheric and whole-atmosphere RFs.

  7. Study of turbocharged diesel engine operation, pollutant emissions and combustion noise radiation during starting with bio-diesel or n-butanol diesel fuel blends

    Rakopoulos, C.D.; Dimaratos, A.M.; Giakoumis, E.G.; Rakopoulos, D.C.

    2011-01-01

    Highlights: → Turbocharged diesel engine emissions during starting with bio-diesel or n-butanol diesel blends. → Peak pollutant emissions due to turbo-lag. → Significant bio-diesel effects on combustion behavior and stability. → Negative effects on NO emissions for both blends. → Positive effects on smoke emissions only for n-butanol blend. -- Abstract: The control of transient emissions from turbocharged diesel engines is an important objective for automotive manufacturers, as stringent criteria for exhaust emissions must be met. Starting, in particular, is a process of significant importance owing to its major contribution to the overall emissions during a transient test cycle. On the other hand, bio-fuels are getting impetus today as renewable substitutes for conventional fuels, especially in the transport sector. In the present work, experimental tests were conducted at the authors' laboratory on a bus/truck, turbocharged diesel engine in order to investigate the formation mechanisms of nitric oxide (NO), smoke, and combustion noise radiation during hot starting for various alternative fuel blends. To this aim, a fully instrumented test bed was set up, using ultra-fast response analyzers capable of capturing the instantaneous development of emissions as well as various other key engine and turbocharger parameters. The experimental test matrix included three different fuels, namely neat diesel fuel and two blends of diesel fuel with either bio-diesel (30% by vol.) or n-butanol (25% by vol.). With reference to the neat diesel fuel case during the starting event, the bio-diesel blend resulted in deterioration of both pollutant emissions as well as increased combustion instability, while the n-butanol (normal butanol) blend decreased significantly exhaust gas opacity but increased notably NO emission.

  8. NOy production, ozone loss and changes in net radiative heating due to energetic particle precipitation in 2002-2010

    Sinnhuber, Miriam; Berger, Uwe; Funke, Bernd; Nieder, Holger; Reddmann, Thomas; Stiller, Gabriele; Versick, Stefan; von Clarmann, Thomas; Maik Wissing, Jan

    2018-01-01

    We analyze the impact of energetic particle precipitation on the stratospheric nitrogen budget, ozone abundances and net radiative heating using results from three global chemistry-climate models considering solar protons and geomagnetic forcing due to auroral or radiation belt electrons. Two of the models cover the atmosphere up to the lower thermosphere, the source region of auroral NO production. Geomagnetic forcing in these models is included by prescribed ionization rates. One model reaches up to about 80 km, and geomagnetic forcing is included by applying an upper boundary condition of auroral NO mixing ratios parameterized as a function of geomagnetic activity. Despite the differences in the implementation of the particle effect, the resulting modeled NOy in the upper mesosphere agrees well between all three models, demonstrating that geomagnetic forcing is represented in a consistent way either by prescribing ionization rates or by prescribing NOy at the model top.Compared with observations of stratospheric and mesospheric NOy from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) instrument for the years 2002-2010, the model simulations reproduce the spatial pattern and temporal evolution well. However, after strong sudden stratospheric warmings, particle-induced NOy is underestimated by both high-top models, and after the solar proton event in October 2003, NOy is overestimated by all three models. Model results indicate that the large solar proton event in October 2003 contributed about 1-2 Gmol (109 mol) NOy per hemisphere to the stratospheric NOy budget, while downwelling of auroral NOx from the upper mesosphere and lower thermosphere contributes up to 4 Gmol NOy. Accumulation over time leads to a constant particle-induced background of about 0.5-1 Gmol per hemisphere during solar minimum, and up to 2 Gmol per hemisphere during solar maximum. Related negative anomalies of ozone are predicted by the models in nearly every polar

  9. Dependence of regular background noise of VLF radiation and thunder-storm activity on solar wind proton density

    Sobolev, A.V.; Kozlov, V.I.

    1997-01-01

    Correlation of the intensity of slowly changing regular background noise within 9.7 kHz frequency in Yakutsk (L = 3) and of the solar wind density protons was determined. This result explains the reverse dependence of the intensity of the regular background noise on the solar activity, 27-day frequency, increase before and following geomagnetic storms, absence of relation with K p index of geomagnetic activity. Conclusion is made that growth of density of the solar wind protons results in increase of the regular background noise and thunderstorm activity

  10. External radiation in Dolon village due to local fallout from the first USSR atomic bomb test in 1949.

    Imanaka, Tetsuji; Fukutani, Satoshi; Yamamoto, Masayoshi; Sakaguchi, Aya; Hoshi, Masaharu

    2006-02-01

    Dolon village, located about 60 km from the border of the Semipalatinsk Nuclear Test Site, is known to be heavily contaminated by local fallout from the first USSR atomic bomb test in 1949. External radiation in Dolon was evaluated based on recent 137Cs data in soil and calculation of temporal change in the fission product composition. After fitting a log-normal distribution to the soil data, a 137Cs deposition of 32 kBq m-2, which corresponds to the 90th-percentile of the distribution, was tentatively chosen as a value to evaluate the radiation situation in 1949. Our calculation indicated that more than 95% of the cumulative dose for 50 y had been delivered within 1 y after the deposition. The resulting cumulative dose for 1 y after the deposition, normalized to the initial contamination containing 1 kBq m-2 of 137Cs, was 15.6 mGy, assuming a fallout arrival time of 3 h and a medium level of fractionation. Finally, 0.50 Gy of absorbed dose in air was derived as our tentative estimate for 1-year cumulative external dose in Dolon due to local fallout from the first USSR test in 1949.

  11. A case of rectovagino-vesical fistula due to radiation therapy for uterine cancer treated with covered expandable metallic stent

    Ohtsukasa, Shunroh; Okabe, Satoshi; Tanami, Hideaki [Tokyo Medical and Dental Univ. (Japan). School of Medicine] (and others)

    2002-04-01

    A 65-year-old woman had received a panhysterectomy and radiation therapy for a uterine cancer in 1974 and underwent a drainage operation for a peritonitis due to rupture of the bladder associated with radiation cystitis in 1983. A rectovesical fistula was revealed and partial resection of the bladder and rectum was performed in 1996. In 1998, rectovesical fistula recurred and symptom of fecaluria and contact-type dermatitis at perineal region subsequently worsened. In February, 2000, colonoscopy and gastrograffin-enema revealed a giant recto-vagino-vesical fistula. Although we recommended ileostomy, the patient refused our offer. She gave informed consent to our proposal about the insertion of a covered expandable metallic stent (EMS) into the rectum to treat for fecaluria. After insertion of a covered EMS, fecaluria and contact-type dermatitis at perineal region subsequently improved. Three months later, fecaluria appeared again. Finally, seven months later, severe inflammation occurred at perineal and pubic region because of migration of the covered EMS into the bladder, then we removed the covered EMS and performed ileostomy. It is difficult to use the covered EMS treatment for benign rectovesical or rectovaginal fistula for a long term. (author)

  12. Estimation of thorium intake due to consumption of vegetables by inhabitants of high background radiation area by INAA

    Sathyapriya, R.S.; Suma Nair; Prabhath, R.K.; Madhu Nair; Rao, D.D.

    2012-01-01

    A study was conducted to estimate the thorium concentration in locally grown vegetables in high background radiation area (HBRA) of southern coastal regions of India. Locally grown vegetables were collected from HBRA of southern coastal regions of India. Thorium concentration was quantified using instrumental neutron activation analysis. The samples were irradiated at CIRUS reactor and counted using a 40% relative efficiency HPGe detector coupled to MCA. The annual intake of thorium was evaluated using the consumption data provided by National Nutrition Monitoring Board. The daily intake of 232 Th from the four food categories (green leafy vegetables, others vegetables, roots and tubers, and fruits) ranged between 0.27 and 5.352 mBq d -1 . The annual internal dose due to ingestion of thorium from these food categories was 46.8 x 10 -8 for female and 58.6 x 10 -8 Sv y -1 for male. (author)

  13. Evapotranspiration estimates and consequences due to errors in the determination of the net radiation and advective effects

    Oliveira, G.M. de; Leitao, M. de M.V.B.R.

    2000-01-01

    The objective of this study was to analyze the consequences in the evapotranspiration estimates (ET) during the growing cycle of a peanut crop due to the errors committed in the determination of the radiation balance (Rn), as well as those caused by the advective effects. This research was conducted at the Experimental Station of CODEVASF in an irrigated perimeter located in the city of Rodelas, BA, during the period of September to December of 1996. The results showed that errors of the order of 2.2 MJ m -2 d -1 in the calculation of Rn, and consequently in the estimate of ET, can occur depending on the time considered for the daily total of Rn. It was verified that the surrounding areas of the experimental field, as well as the areas of exposed soil within the field, contributed significantly to the generation of local advection of sensible heat, which resulted in the increase of the evapotranspiration [pt

  14. On the evaluation of the sensitivity of SRAM-Based FPGA to errors due to natural radiation environment

    Bocquillon, Alexandre

    2009-01-01

    This work aims at designing a test methodology to analyze the effect of natural radiation on FPGA SRAM-based chip-sets. Study of likely errors due to single or multiple events occurring in the configuration memory will be based on fault-injection experiments performed with laser devices. It relies on both a description of scientific background and a description of complex architecture of FPGA SRAM-Based and usual testing apparatus. Fault injection experiments with laser are conducted on several classes of components in order to perform static tests of the configuration memory and identify the links with the application. It shows the organization and sensitivity of SRAM configuration cells. Criticality criteria for configuration bits have been specified following dynamic tests in protons accelerator, in regard to their impact on the application. From this classification was developed a predicting tool for critical error rate estimation. (author) [fr

  15. Mirror Symmetry Breaking and Restoration: The Role of Noise and Chiral Bias

    Hochberg, David

    2009-01-01

    The nonequilibrium effective potential is computed for the Frank model of spontaneous mirror symmetry breaking (SMSB) in chemistry in which external noise is introduced to account for random environmental effects. When these fluctuations exceed a critical magnitude, mirror symmetry is restored. The competition between ambient noise and the chiral bias due to physical fields and polarized radiation can be explored with this potential.

  16. Natural and man-made terrestrial electromagnetic noise: an outlook

    A. Meloni

    2007-06-01

    Full Text Available The terrestrial environment is continuously exposed to electromagnetic radiations which set up a «background» electromagnetic noise. Within the Non Ionizing Radiation band (NIR, i.e. for frequencies lower than 300 GHz, this background can have a natural or an artificial origin. Natural origins of electromagnetic radiations are generally atmospheric or cosmic while artificial origins are technological applications, power transmission, communications, etc. This paper briefly describes the natural and man-made electromagnetic noise in the NIR band. Natural noise comes from a large variety of sources involving different physical phenomena and covering a wide range of frequencies and showing various propagation characteristics with an extremely broad range of power levels. Due to technological growth man-made electromagnetic noise is nowadays superimposed on natural noise almost everywhere on Earth. In the last decades man-made noise has increased dramatically over and above the natural noise in residential and business areas. This increase has led some scientists to consider possible negative effects of electromagnetic waves on human life and living systems in general. Accurate measurements of natural and man-made electromagnetic noise are necessary to understand the relative power levels in the different bands and their influence on life.

  17. Chemical and climatic drivers of radiative forcing due to changes in stratospheric and tropospheric ozone over the 21st century

    A. Banerjee

    2018-02-01

    Full Text Available The ozone radiative forcings (RFs resulting from projected changes in climate, ozone-depleting substances (ODSs, non-methane ozone precursor emissions and methane between the years 2000 and 2100 are calculated using simulations from the UM-UKCA chemistry–climate model (UK Met Office's Unified Model containing the United Kingdom Chemistry and Aerosols sub-model. Projected measures to improve air-quality through reductions in non-methane tropospheric ozone precursor emissions present a co-benefit for climate, with a net global mean ozone RF of −0.09 W m−2. This is opposed by a positive ozone RF of 0.05 W m−2 due to future decreases in ODSs, which is driven by an increase in tropospheric ozone through stratosphere-to-troposphere transport of air containing higher ozone amounts. An increase in methane abundance by more than a factor of 2 (as projected by the RCP8.5 scenario is found to drive an ozone RF of 0.18 W m−2, which would greatly outweigh the climate benefits of non-methane tropospheric ozone precursor reductions. A small fraction (∼ 15 % of the ozone RF due to the projected increase in methane results from increases in stratospheric ozone. The sign of the ozone RF due to future changes in climate (including the radiative effects of greenhouse gases, sea surface temperatures and sea ice changes is shown to be dependent on the greenhouse gas emissions pathway, with a positive RF (0.05 W m−2 for RCP4.5 and a negative RF (−0.07 W m−2 for the RCP8.5 scenario. This dependence arises mainly from differences in the contribution to RF from stratospheric ozone changes. Considering the increases in tropopause height under climate change causes only small differences (≤ |0.02| W m−2 for the stratospheric, tropospheric and whole-atmosphere RFs.

  18. NOy production, ozone loss and changes in net radiative heating due to energetic particle precipitation in 2002–2010

    M. Sinnhuber

    2018-01-01

    Full Text Available We analyze the impact of energetic particle precipitation on the stratospheric nitrogen budget, ozone abundances and net radiative heating using results from three global chemistry-climate models considering solar protons and geomagnetic forcing due to auroral or radiation belt electrons. Two of the models cover the atmosphere up to the lower thermosphere, the source region of auroral NO production. Geomagnetic forcing in these models is included by prescribed ionization rates. One model reaches up to about 80 km, and geomagnetic forcing is included by applying an upper boundary condition of auroral NO mixing ratios parameterized as a function of geomagnetic activity. Despite the differences in the implementation of the particle effect, the resulting modeled NOy in the upper mesosphere agrees well between all three models, demonstrating that geomagnetic forcing is represented in a consistent way either by prescribing ionization rates or by prescribing NOy at the model top.Compared with observations of stratospheric and mesospheric NOy from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS instrument for the years 2002–2010, the model simulations reproduce the spatial pattern and temporal evolution well. However, after strong sudden stratospheric warmings, particle-induced NOy is underestimated by both high-top models, and after the solar proton event in October 2003, NOy is overestimated by all three models. Model results indicate that the large solar proton event in October 2003 contributed about 1–2 Gmol (109 mol NOy per hemisphere to the stratospheric NOy budget, while downwelling of auroral NOx from the upper mesosphere and lower thermosphere contributes up to 4 Gmol NOy. Accumulation over time leads to a constant particle-induced background of about 0.5–1 Gmol per hemisphere during solar minimum, and up to 2 Gmol per hemisphere during solar maximum. Related negative anomalies of ozone are predicted by

  19. Estimation of tumour dose enhancement due to gold nanoparticles during typical radiation treatments: a preliminary Monte Carlo study

    Cho, S H

    2005-01-01

    A recent mice study demonstrated that gold nanoparticles could be safely administered and used to enhance the tumour dose during radiation therapy. The use of gold nanoparticles seems more promising than earlier methods because of the high atomic number of gold and because nanoparticles can more easily penetrate the tumour vasculature. However, to date, possible dose enhancement due to the use of gold nanoparticles has not been well quantified, especially for common radiation treatment situations. Therefore, the current preliminary study estimated this dose enhancement by Monte Carlo calculations for several phantom test cases representing radiation treatments with the following modalities: 140 kVp x-rays, 4 and 6 MV photon beams, and 192 Ir gamma rays. The current study considered three levels of gold concentration within the tumour, two of which are based on the aforementioned mice study, and assumed either no gold or a single gold concentration level outside the tumour. The dose enhancement over the tumour volume considered for the 140 kVp x-ray case can be at least a factor of 2 at an achievable gold concentration of 7 mg Au/g tumour assuming no gold outside the tumour. The tumour dose enhancement for the cases involving the 4 and 6 MV photon beams based on the same assumption ranged from about 1% to 7%, depending on the amount of gold within the tumour and photon beam qualities. For the 192 Ir cases, the dose enhancement within the tumour region ranged from 5% to 31%, depending on radial distance and gold concentration level within the tumour. For the 7 mg Au/g tumour cases, the loading of gold into surrounding normal tissue at 2 mg Au/g resulted in an increase in the normal tissue dose, up to 30%, negligible, and about 2% for the 140 kVp x-rays, 6 MV photon beam, and 192 Ir gamma rays, respectively, while the magnitude of dose enhancement within the tumour was essentially unchanged. (note)

  20. ALDO: A radiation-tolerant, low-noise, adjustable low drop-out linear regulator in 0.35 μm CMOS technology

    Carniti, P.; Cassina, L.; Gotti, C.; Maino, M.; Pessina, G.

    2016-01-01

    In this work we present ALDO, an adjustable low drop-out linear regulator designed in AMS 0.35 μm CMOS technology. It is specifically tailored for use in the upgraded LHCb RICH detector in order to improve the power supply noise for the front end readout chip (CLARO). ALDO is designed with radiation-tolerant solutions such as an all-MOS band-gap voltage reference and layout techniques aiming to make it able to operate in harsh environments like High Energy Physics accelerators. It is capable of driving up to 200 mA while keeping an adequate power supply filtering capability in a very wide frequency range from 10 Hz up to 100 MHz. This property allows us to suppress the noise and high frequency spikes that could be generated by a DC/DC regulator, for example. ALDO also shows a very low noise of 11.6 μV RMS in the same frequency range. Its output is protected with over-current and short detection circuits for a safe integration in tightly packed environments. Design solutions and measurements of the first prototype are presented.

  1. ALDO: A radiation-tolerant, low-noise, adjustable low drop-out linear regulator in 0.35 μm CMOS technology

    Carniti, P., E-mail: paolo.carniti@mib.infn.it [INFN, Sezione di Milano Bicocca, I-20126 Milano (Italy); Dipartimento di Fisica, Università di Milano Bicocca, I-20126 Milano (Italy); Cassina, L.; Gotti, C.; Maino, M.; Pessina, G. [INFN, Sezione di Milano Bicocca, I-20126 Milano (Italy); Dipartimento di Fisica, Università di Milano Bicocca, I-20126 Milano (Italy)

    2016-07-11

    In this work we present ALDO, an adjustable low drop-out linear regulator designed in AMS 0.35 μm CMOS technology. It is specifically tailored for use in the upgraded LHCb RICH detector in order to improve the power supply noise for the front end readout chip (CLARO). ALDO is designed with radiation-tolerant solutions such as an all-MOS band-gap voltage reference and layout techniques aiming to make it able to operate in harsh environments like High Energy Physics accelerators. It is capable of driving up to 200 mA while keeping an adequate power supply filtering capability in a very wide frequency range from 10 Hz up to 100 MHz. This property allows us to suppress the noise and high frequency spikes that could be generated by a DC/DC regulator, for example. ALDO also shows a very low noise of 11.6 μV RMS in the same frequency range. Its output is protected with over-current and short detection circuits for a safe integration in tightly packed environments. Design solutions and measurements of the first prototype are presented.

  2. ALDO: A radiation-tolerant, low-noise, adjustable low drop-out linear regulator in 0.35 μm CMOS technology

    Carniti, P.; Cassina, L.; Gotti, C.; Maino, M.; Pessina, G.

    2016-07-01

    In this work we present ALDO, an adjustable low drop-out linear regulator designed in AMS 0.35 μm CMOS technology. It is specifically tailored for use in the upgraded LHCb RICH detector in order to improve the power supply noise for the front end readout chip (CLARO). ALDO is designed with radiation-tolerant solutions such as an all-MOS band-gap voltage reference and layout techniques aiming to make it able to operate in harsh environments like High Energy Physics accelerators. It is capable of driving up to 200 mA while keeping an adequate power supply filtering capability in a very wide frequency range from 10 Hz up to 100 MHz. This property allows us to suppress the noise and high frequency spikes that could be generated by a DC/DC regulator, for example. ALDO also shows a very low noise of 11.6 μV RMS in the same frequency range. Its output is protected with over-current and short detection circuits for a safe integration in tightly packed environments. Design solutions and measurements of the first prototype are presented.

  3. Greenhouse impact due to the use of combustible fuels: life cycle viewpoint and relative radiative forcing commitment.

    Kirkinen, Johanna; Palosuo, Taru; Holmgren, Kristina; Savolainen, Ilkka

    2008-09-01

    Extensive information on the greenhouse impacts of various human actions is important in developing effective climate change mitigation strategies. The greenhouse impacts of combustible fuels consist not only of combustion emissions but also of emissions from the fuel production chain and possible effects on the ecosystem carbon storages. It is important to be able to assess the combined, total effect of these different emissions and to express the results in a comprehensive way. In this study, a new concept called relative radiative forcing commitment (RRFC) is presented and applied to depict the greenhouse impact of some combustible fuels currently used in Finland. RRFC is a ratio that accounts for the energy absorbed in the Earth system due to changes in greenhouse gas concentrations (production and combustion of fuel) compared to the energy released in the combustion of fuel. RRFC can also be expressed as a function of time in order to give a dynamic cumulative picture on the caused effect. Varying time horizons can be studied separately, as is the case when studying the effects of different climate policies on varying time scales. The RRFC for coal for 100 years is about 170, which means that in 100 years 170 times more energy is absorbed in the atmosphere due to the emissions of coal combustion activity than is released in combustion itself. RRFC values of the other studied fuel production chains varied from about 30 (forest residues fuel) to 190 (peat fuel) for the 100-year study period. The length of the studied time horizon had an impact on the RRFC values and, to some extent, on the relative positions of various fuels.

  4. Germany (Federal Republic). Ministry of the Interior. Order on protection against damage due to ionising radiation. Radiation Protectin Order. StrlSchV 20 Oct. 1976

    1977-02-01

    The order is arranged in parts, entitled: introductory provisions; control provisions (handling radioactive matter, the carriage of radioactive matter, the import and export of radioactive matter, the construction and operation of installation for generating ionising radiation, employees and other persons working under supervision, design approval); safety regulations (general regulations, protection of the population and the environment against the hazards of ionising radiation, occupational exposure to radiation, radiation protection areas, physical protection and control, medical supervision, instruments for measuring radiation, other safety regulations); fines; and final provisions. (U.K.)

  5. Internal radiation dose to the public from polonium-210 due to consumption of seafood from Bombay-harbour bay

    Bangera, V.S.; Rudran, Kamala

    1995-01-01

    Marine organisms such as fishes, molluscs and crustaceans are known to accumulate 210 Po. Distribution of 210 Po in coastal marine organisms mainly fishes and shell fishes is studied. Concentration of 210 Po obtained in muscle of common fishes (edible portion) varied from 2.10 ± 0.11 to 21.90 ± 5.00 Bq kg -1 dry muscle (for fishes like Pampus argenteus (Pomfret), Cynoglossus elongatus (sole), Rastrelliger kanagurta (mackerel), Harpodon nehereus (Bombay duck) etc. Concentration factors for 210 Po in edible portion of fish from sea water works out to 10 3 to 10 4 . Radiation dose to the public has been evaluated on the basis of daily intake of 40 g of fish (15 kg y -1 ). Committed effective dose (CED) to 210 Po due to consumption of sea food is calculated, CED varied from 2.05 x 10 -3 to 4 x 10 -2 mSv y -1 . (author). 7 refs., 3 figs., 3 tabs

  6. Evaluation of stress distribution due to shearing in non-oriented electrical steel by using synchrotron radiation

    Yoshiaki Zaizen

    2016-05-01

    Full Text Available The influence of the shearing process on the iron loss of non-oriented electrical steels with grain sizes of 10 μm-150 μm was investigated. The deterioration ratio of iron loss was clearly smaller in sample with small grain sizes. The droop height, reflecting the amount of plastic deformation, displayed a good relationship with the deterioration of iron loss under the effect of the material grain size. To clarify the strain distribution around the sheared edge, the elastic strain in a sheet sample with the thickness of 0.30 mm and grain size of 10 μm was evaluated by using synchrotron radiation. The width of the region of elastic strain due to shearing was two or three times of the material thickness. The results of the plastic strain distribution obtained by the measurements were then used to estimate the iron loss deterioration rate in 5 mm width sheared samples. The estimated loss deteriotation coincided with the actual measured iron loss.

  7. Evaluation of stress distribution due to shearing in non-oriented electrical steel by using synchrotron radiation

    Zaizen, Yoshiaki, E-mail: y-zaizen@jfe-steel.co.jp; Omura, Takeshi; Senda, Kunihiro [Steel Research Laboratory, JFE Steel Corporation, Kawasakidori 1,Mizushima, Kurashiki,712-8511 (Japan); Fukumura, Masaru [Steel Research Laboratory, JFE Steel Corporation, Kawasaki, Kanagawa 210-0855 (Japan); Toda, Hiroaki [Steel Business Planning Dept, JFE Steel Corporation, Tokyo 100-0011 (Japan)

    2016-05-15

    The influence of the shearing process on the iron loss of non-oriented electrical steels with grain sizes of 10 μm-150 μm was investigated. The deterioration ratio of iron loss was clearly smaller in sample with small grain sizes. The droop height, reflecting the amount of plastic deformation, displayed a good relationship with the deterioration of iron loss under the effect of the material grain size. To clarify the strain distribution around the sheared edge, the elastic strain in a sheet sample with the thickness of 0.30 mm and grain size of 10 μm was evaluated by using synchrotron radiation. The width of the region of elastic strain due to shearing was two or three times of the material thickness. The results of the plastic strain distribution obtained by the measurements were then used to estimate the iron loss deterioration rate in 5 mm width sheared samples. The estimated loss deteriotation coincided with the actual measured iron loss.

  8. Radiation and Background Levels in a CLIC Detector due to Beam-Beam Effects Optimisation of Detector Geometries and Technologies

    Sailer, André; Lohse, Thomas

    2013-01-10

    The high charge density---due to small beam sizes---and the high energy of the proposed CLIC concept for a linear electron--positron collider with a centre-of-mass energy of up to 3~TeV lead to the production of a large number of particles through beam-beam interactions at the interaction point during every bunch crossing (BX). A large fraction of these particles safely leaves the detector. A still significant amount of energy will be deposited in the forward region nonetheless, which will produce secondary particles able to cause background in the detector. Furthermore, some particles will be created with large polar angles and directly cause background in the tracking detectors and calorimeters. The main sources of background in the detector, either directly or indirectly, are the incoherent $mathrm{e}^{+}mathrm{e}^{-}$ pairs and the particles from $gammagamma ightarrow$ hadron events. The background and radiation levels in the detector have to be estimated, to study if a detector is feasible, that can han...

  9. Do perceived job insecurity and annoyance due to air and noise pollution predict incident self-rated poor health? A prospective analysis of independent and joint associations using a German national representative cohort study.

    Riedel, Natalie; Loerbroks, Adrian; Bolte, Gabriele; Li, Jian

    2017-01-23

    Current economic and social change has contributed to increasing job insecurity and traffic-related pollution in residential areas. Both job insecurity and exposure to noise and air pollution are known determinants of population health and can concur in peoples' lives. This may hold true particularly for socially disadvantaged subpopulations. Nevertheless, the potential independent and joint links of those exposures to health have been rarely examined so far. We aimed to contribute to the scarce body of evidence. Information on perceived job insecurity and exposures to noise and air pollution as expressed by annoyance as well as on self-rated health were gathered from 2 waves of the population-based German Socio-Economic Panel (2009 and 2011, N=6544). We performed multivariable Poisson regression to examine the independent and joint risk of poor health in 2011 by perceived job insecurity and annoyance due to noise and air pollution in 2009. After the 2-year follow-up in 2011, 571 (8.7%) participants rated their health as poor. The risk of reporting incident poor health was increased by roughly 40% in employees reporting high versus low perceived job insecurity and annoyance due to noise and air pollution, respectively. This risk increased when both exposures were present at higher levels (risk ratio=1.95 (1.49 to 2.55)). Work-related and environmental exposures may accumulate and have a joint health impact. Elaboration on the link between occupational and residential exposures is warranted in the light of their concurrence and their implications for health inequities. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  10. Minimising radiation exposure due to source assembly-related deficiencies in industrial gamma radiography exposure devices (IGREDs)

    Sivaraman, G.; Kannan, R.; Nandakumar, A.N.; Subrahmanya, M.J.; Murthy, B.K.S.

    2000-01-01

    Industrial radiographers receive higher doses as compared to radiation workers in medicine, agriculture, research, etc. Hence, it is essential that industrial gamma radiography exposure device (IGRED) be provided with efficient and effective safety systems in their design and operation to ensure smooth operation and minimise radiation exposures to the operators and public. Even though all these exposure devices have undergone stringent tests for radiographic exposure devices under international or national standards, certain deficiencies were noticed when scientists of Radiological Physics and Advisory Division (RPAD), carried out radiography equipment inspection of IGREDs. Some examples are briefly described here. The use of depleted Uranium pencil in some models led to the source pencil getting jammed due to formation of Uranium Oxide and bulging of the pencil. The solution was to replace the uranium pencil with high quality tungsten pencils or stainless steel clad pencils. In one type of pencils the source assembly would flare up after some use obstructing the smooth movement of the source assembly. The suggestion to subject the source assemblies to heat treatment solved the problem. In another type, the source pencil was getting corroded in high humid condition and affected the source movement. When the composition of the source pencil was changed it could withstand high humid condition. Another model had a hook type coupling between source assembly and drive cable. This often resulted in disengagement of the source assembly from the drive cable. Suggestions were made to change the coupling to ball and socket coupling for smooth functioning and for 'fail-safe' operation. During early days of the use of remote operated IGRED, in one particular model of the IGRED, the Iridium source wafers were directly loaded in a single encapsulation. Once the welding gave way and the source wafers got strewn. Subsequently, the source pellets/wafers were doubly encapsulated

  11. Noise from wind turbines

    Fegeant, Olivier [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Building Sciences

    2002-02-01

    A rapid growth of installed wind power capacity is expected in the next few years. However, the siting of wind turbines on a large scale raises concerns about their environmental impact, notably with respect to noise. To this end, variable speed wind turbines offer a promising solution for applications in densely populated areas like the European countries, as this design would enable an efficient utilisation of the masking effect due to ambient noise. In rural and recreational areas where wind turbines are sited, the ambient noise originates from the action of wind on the vegetation and about the listener's ear (pseudo-noise). It shows a wind speed dependence similar to that of the noise from a variable speed wind turbine and can therefore mask the latter for a wide range of conditions. However, a problem inherent to the design of these machines is their proclivity to pure tone generation, because of the enhanced difficulty of avoiding structural resonances in the mechanical parts. Pure tones are deemed highly annoying and are severely regulated by most noise policies. In relation to this problem, the vibration transmission of structure-borne sound to the tower of the turbine is investigated, in particular when the tower is stiffened at its upper end. Furthermore, since noise annoyance due to wind turbine is mostly a masking issue, the wind-related sources of ambient noise are studied and their masking potentials assessed. With this aim, prediction models for wind-induced vegetation noise and pseudo-noise have been developed. Finally, closely related to the effect of masking, is the difficulty, regularly encountered by local authorities and wind farm developers, to measure noise immission from wind turbines. A new measurement technique has thus been developed in the course of this work. Through improving the signal-to-noise ratio between wind turbine noise and ambient noise, the new technique yields more accurate measurement results.

  12. The role of Urbis' noise and noise effects maps in local policy

    Borst, H.C.

    2001-01-01

    An important aspect of the EU noise policy is mapping of noise and noise effects and the formulation of noise action plans. In the Netherlands, due to the new policy on noise (MIG), the municipalities will be responsible for the formulation of a local noise policy. An instrument for the assessment

  13. Classifying and assembling two-dimensional X-ray laser diffraction patterns of a single particle to reconstruct the three-dimensional diffraction intensity function: resolution limit due to the quantum noise.

    Tokuhisa, Atsushi; Taka, Junichiro; Kono, Hidetoshi; Go, Nobuhiro

    2012-05-01

    A new two-step algorithm is developed for reconstructing the three-dimensional diffraction intensity of a globular biological macromolecule from many experimentally measured quantum-noise-limited two-dimensional X-ray laser diffraction patterns, each for an unknown orientation. The first step is classification of the two-dimensional patterns into groups according to the similarity of direction of the incident X-rays with respect to the molecule and an averaging within each group to reduce the noise. The second step is detection of common intersecting circles between the signal-enhanced two-dimensional patterns to identify their mutual location in the three-dimensional wavenumber space. The newly developed algorithm enables one to detect a signal for classification in noisy experimental photon-count data with as low as ~0.1 photons per effective pixel. The wavenumber of such a limiting pixel determines the attainable structural resolution. From this fact, the resolution limit due to the quantum noise attainable by this new method of analysis as well as two important experimental parameters, the number of two-dimensional patterns to be measured (the load for the detector) and the number of pairs of two-dimensional patterns to be analysed (the load for the computer), are derived as a function of the incident X-ray intensity and quantities characterizing the target molecule. © 2012 International Union of Crystallography

  14. Study of noise sources of image for optimization of radiation doses in skull computerized tomography; Estudo das fontes de ruido da imagem para fins de otimizacao das doses na tomografia computadorizada de cranio

    Medeiros, R.B.; Garos, K.A.C. [UNIFESP - Universidade Federal de Sao Paulo, SP (Brazil)]. E-mail: rbitelli@cfrh.epm.br

    2001-07-01

    Our goal was to evaluate the exposure factors that can change the image noise of head CT in different slices thicknesses. We have evaluated the images noise at several mAs varying from 50 to 800 mAs for 100, 120 and 140 kVp as tension values. The images uniformity were determined for all technical exposure conditions. We did not observed any important noise reduction for values up 200 mAs which can justify the increase of radiation doses through the increase of mAs. (author)

  15. Frequency shift due to blackbody radiation in a cesium atomic fountain and improvement of the clock performances

    Zhang, S.

    2004-07-01

    FO1 was the first caesium fountain primary frequency standard in the world. The most recent evaluation in 2002 before improvement reached an accuracy of 1*10 -15 when operated with optical molasses. Working as an extremely precise and stable instrument, FO1 has contributed to fundamental physics and technical measurements: - Frequency comparison between Cs and Rb fountains over an interval of 5 years sets an upper limit for a possible variation of the fine structure constant as |alpha/alpha| -15 /y. The resolution is about 5 times better than the previous test in our laboratory. The projected accuracy of the space clock PHARAO is 1*10 -16 . We confirmed its Ramsey cavity performance by testing the phase difference between the two interaction zones in FO1. The measured temperature T dependent frequency shift of the Cs clock induced by the blackbody radiation field is given as nu(T)=154(6)*10 -6 *(T/300) 4 [1+ε(T/300) 2 ] Hz with the theoretical value ε = 0,014. The obtained accuracy represents a 3 times improvement over the previous measurement by the PTB group. Some improvements have been carried out on FO1. The new FO1 version works directly with optical molasses loaded by a laser slowed atomic beam. The application of the adiabatic passage method to perform the state selection allows us to determine the atom number dependent frequency shifts due to the cold collision and cavity pulling effects at a level of of 10 -16 . Recently, the obtained frequency stability is 2,8*10 -14 *τ -1/2 for about 4*10 6 detected atoms. The accuracy is currently under evaluation, the expected value is a few times 10 -16 . (author)

  16. Assessment of ocular beta radiation dose distribution due to 106Ru/106Rh brachytherapy applicators using MCNPX Monte Carlo code

    Nilseia Aparecida Barbosa

    2014-08-01

    heterogeneous eye model, indicating that the homogeneous water eye model is a reasonable one. The determined isodose curves give a good visualization of dose distributions inside the eye structures, pointing out their most exposed volume....................................................Cite this article as:Barbosa NA, da Rosa LAR, de Menezes AF, Reis JP, Facure A, Braz D. Assessment of ocular beta radiation dose distribution due to 106Ru/106Rh brachytherapy applicators using MCNPX Monte Carlo code. Int J Cancer Ther Oncol 2014; 2(3:02038. DOI: 10.14319/ijcto.0203.8

  17. Dosimetry problems when evaluating radiation effects on the personnel, restoration work participants, and human population due to the Chernobyl accident

    Abramov, Yu.V.; Osanov, D.P.; Gimadova, T.I.; Gus'kov, V.M.; Kruchkov, V.P.; Pavlov, D.A.; Shaks, A.I.

    1993-01-01

    System of radiation monitoring operations of the Chernobyl NPP personnel is described for the period from the date of accident up to present time as well as of persons worked in the Chernobyl NPP 30 km zone, servicemen, and human population. Unsatisfactory organization of radiation on monitoring is marked and causes of this fact are considered. 8 refs.; 3 figs

  18. The modification of equipotential surfaces in the binary systems due to the pressure of the radiation of its components

    Zorec, Juan; Niemela, Virpi

    1980-01-01

    The modification of the equipotential surfaces of a binary system is studied when the radiation pressure of both components must be taken into account. For suitable values of the radiation parameters, new forms of mass transfer or mass loss may arise [fr

  19. Classifying and assembling two-dimensional X-ray laser diffraction patterns of a single particle to reconstruct the three-dimensional diffraction intensity function: resolution limit due to the quantum noise

    Tokuhisa, Atsushi; Taka, Junichiro; Kono, Hidetoshi; Go, Nobuhiro

    2012-01-01

    A new algorithm is developed for reconstructing the high-resolution three-dimensional diffraction intensity function of a globular biological macromolecule from many quantum-noise-limited two-dimensional X-ray laser diffraction patterns, each for an unknown orientation. The structural resolution is expressed as a function of the incident X-ray intensity and quantities characterizing the target molecule. A new two-step algorithm is developed for reconstructing the three-dimensional diffraction intensity of a globular biological macromolecule from many experimentally measured quantum-noise-limited two-dimensional X-ray laser diffraction patterns, each for an unknown orientation. The first step is classification of the two-dimensional patterns into groups according to the similarity of direction of the incident X-rays with respect to the molecule and an averaging within each group to reduce the noise. The second step is detection of common intersecting circles between the signal-enhanced two-dimensional patterns to identify their mutual location in the three-dimensional wavenumber space. The newly developed algorithm enables one to detect a signal for classification in noisy experimental photon-count data with as low as ∼0.1 photons per effective pixel. The wavenumber of such a limiting pixel determines the attainable structural resolution. From this fact, the resolution limit due to the quantum noise attainable by this new method of analysis as well as two important experimental parameters, the number of two-dimensional patterns to be measured (the load for the detector) and the number of pairs of two-dimensional patterns to be analysed (the load for the computer), are derived as a function of the incident X-ray intensity and quantities characterizing the target molecule

  20. Radiation

    Winther, J.F.; Ulbak, K.; Dreyer, L.; Pukkala, E.; Oesterlind, A.

    1997-01-01

    Exposure to solar and ionizing radiation increases the risk for cancer in humans. Some 5% of solar radiation is within the ultraviolet spectrum and may cause both malignant melanoma and non-melanocytic skin cancer; the latter is regarded as a benign disease and is accordingly not included in our estimation of avoidable cancers. Under the assumption that the rate of occurrence of malignant melanoma of the buttocks of both men and women and of the scalp of women would apply to all parts of the body in people completely unexposed to solar radiation, it was estimated that approximately 95% of all malignant melanomas arising in the Nordic populations around the year 2000 will be due to exposure to natural ultraviolet radiation, equivalent to an annual number of about 4700 cases, with 2100 in men and 2600 in women, or some 4% of all cancers notified. Exposure to ionizing radiation in the Nordic countries occurs at an average effective dose per capita per year of about 3 mSv (Iceland, 1.1 mSv) from natural sources, and about 1 mSv from man-made sources. While the natural sources are primarily radon in indoor air, natural radionuclides in food, cosmic radiation and gamma radiation from soil and building materials, the man-made sources are dominated by the diagnostic and therapeutic use of ionizing radiation. On the basis of measured levels of radon in Nordic dwellings and associated risk estimates for lung cancer derived from well-conducted epidemiological studies, we estimated that about 180 cases of lung cancer (1% of all lung cancer cases) per year could be avoided in the Nordic countries around the year 2000 if indoor exposure to radon were eliminated, and that an additional 720 cases (6%) could be avoided annually if either radon or tobacco smoking were eliminated. Similarly, it was estimated that the exposure of the Nordic populations to natural sources of ionizing radiation other than radon and to medical sources will each give rise to an annual total of 2120

  1. A study on optimal scan conditions of big bore multi-slice computed tomography based on radiation dose and image noise

    Lee, J. S.; Ye, S. J.; Kim, E. H.

    2011-01-01

    The newly introduced Big Bore computed tomography (CT) has a possibility to increase the tube current product scan time (mA s) for compensation of image degradation due to larger gentry opening without sound guideline. The objective of this paper is to derive optimal scan conditions for Big Bore CT scanner, mainly relating to the dose of diagnostic CT. The weighted CT dose index (CTDI w ) was estimated at five typical protocols, such as head and neck, brain, paediatric, chest and abdomen. Noises were analysed in a circle of 1 or 2 cm of diameter in CT image slice. The results showed that measured CTDI w values generally follow the theoretical rule at all scanning conditions of every protocol. Although image noises decrease with increment of mA s, analysed image noises do follow the theoretical rule, but only in specific protocols. This phenomenon is presumed to result from the photon energy spectra arriving at the detection system of the Big Bore scanner. (authors)

  2. Study of the impact of board orientation on radiated emissions due to common-mode currents on attached cables

    Sørensen, Morten; Hubing, Todd H.; Jensen, Kim

    2016-01-01

    Common-mode current on attached cables is a typical source for radiated emission. Several models have been made for conversion of the intended differential signal to unwanted common-mode current on cables. In this paper we refine a method for identifying the radiation sources arising from a long...... microstrip. This method is used to show that the radiated emission from a PCB with attached cable(s) caused by a long trace depends on whether the trace is facing up or down with different result for voltage and current sources....

  3. Radiative forcing over the conterminous United States due to contemporary land cover land use change and sensitivity to snow and interannual albedo variability

    Barnes, Christopher A.; Roy, David P.

    2010-01-01

    Satellite-derived land cover land use (LCLU), snow and albedo data, and incoming surface solar radiation reanalysis data were used to study the impact of LCLU change from 1973 to 2000 on surface albedo and radiative forcing for 58 ecoregions covering 69% of the conterminous United States. A net positive surface radiative forcing (i.e., warming) of 0.029 Wm−2 due to LCLU albedo change from 1973 to 2000 was estimated. The forcings for individual ecoregions were similar in magnitude to current global forcing estimates, with the most negative forcing (as low as −0.367 Wm−2) due to the transition to forest and the most positive forcing (up to 0.337 Wm−2) due to the conversion to grass/shrub. Snow exacerbated both negative and positive forcing for LCLU transitions between snow-hiding and snow-revealing LCLU classes. The surface radiative forcing estimates were highly sensitive to snow-free interannual albedo variability that had a percent average monthly variation from 1.6% to 4.3% across the ecoregions. The results described in this paper enhance our understanding of contemporary LCLU change on surface radiative forcing and suggest that future forcing estimates should model snow and interannual albedo variation.

  4. Electron Microscopy Study of Stainless Steel Radiation Damage Due to Long-Term Irradation by Alpha Particles Emitted From Plutonium

    Unlu, Kenan [Univ. of Texas, Austin, TX (United States); Rios-Martinez, Carlos [Univ. of Texas, Austin, TX (United States); Saglam, Mehmet [Univ. of Texas, Austin, TX (United States); Hart, Ron R. [Texas A & M Univ., College Station, TX (United States); Shipp, John D. [Texas A & M Univ., College Station, TX (United States); Rennie, John [Texas A & M Univ., College Station, TX (United States)

    1998-04-16

    Radiation damage and associated surface and microstructural changes produced in stainless steel encapsulation by high-fluence alpha particle irradiations from weapons-grade plutonium of 316-stainless steel are being investigated.

  5. A comparison between the performance degradation of 3T APS due to radiation exposure and the expected internal damage via Monte-Carlo Simulation

    Kim, Gi Yoon; Kim, Myung Soo; Lim, Kyung Taek; Lee, Eun Jung; Kim, Chan Kyu [Dept. of Nuclear and Quantum Engineering, KAIST, Daejeon (Korea, Republic of); Park, Jong Hwan [Luvantix ADM , Daejeon (Korea, Republic of)

    2015-02-15

    The trend of x-ray image sensor has been evolved from an amorphous silicon sensor to a crystal silicon sensor. A crystal silicon X-ray sensor, meaning a X-ray CIS (CMOS image sensor), is consisted of three transistors (Trs), i.e., a Reset Transistor, a Source Follower and a Select Transistor, and a photodiode. They are highly sensitive to radiation exposure. As the frequency of exposure to radiation increases, the quality of the imaging device dramatically decreases. The most well known effects of a X-ray CIS due to the radiation damage are increments in the reset voltage and dark currents. In this study, a pixel array of a X-ray CIS was made of 20×20 pixels and this pixel array was exposed to a high radiation dose. The radiation source was Co-60 and the total radiation dose was increased from 1 to 9 kGy with a step of 1 kGy. We irradiated the small pixel array to get the increments data of the reset voltage and the dark currents. Also, we simulated the radiation effects of the pixel by MCNP (Monte Carlo N-Particle) simulation. From the comparison of actual data and simulation data, the most affected location could be determined and the cause of the increments of the reset voltage and dark current could be found.

  6. Phylogenetic signal detection from an ancient rapid radiation: Effects of noise reduction, long-branch attraction, and model selection in crown clade Apocynaceae.

    Straub, Shannon C K; Moore, Michael J; Soltis, Pamela S; Soltis, Douglas E; Liston, Aaron; Livshultz, Tatyana

    2014-11-01

    Crown clade Apocynaceae comprise seven primary lineages of lianas, shrubs, and herbs with a diversity of pollen aggregation morphologies including monads, tetrads, and pollinia, making them an ideal group for investigating the evolution and function of pollen packaging. Traditional molecular systematic approaches utilizing small amounts of sequence data have failed to resolve relationships along the spine of the crown clade, a likely ancient rapid radiation. The previous best estimate of the phylogeny was a five-way polytomy, leaving ambiguous the homology of aggregated pollen in two major lineages, the Periplocoideae, which possess pollen tetrads, and the milkweeds (Secamonoideae plus Asclepiadoideae), which possess pollinia. To assess whether greatly increased character sampling would resolve these relationships, a plastome sequence data matrix was assembled for 13 taxa of Apocynaceae, including nine newly generated complete plastomes, one partial new plastome, and three previously reported plastomes, collectively representing all primary crown clade lineages and outgroups. The effects of phylogenetic noise, long-branch attraction, and model selection (linked versus unlinked branch lengths among data partitions) were evaluated in a hypothesis-testing framework based on Shimodaira-Hasegawa tests. Discrimination among alternative crown clade resolutions was affected by all three factors. Exclusion of the noisiest alignment positions and topologies influenced by long-branch attraction resulted in a trichotomy along the spine of the crown clade consisting of Rhabdadenia+the Asian clade, Baisseeae+milkweeds, and Periplocoideae+the New World clade. Parsimony reconstruction on all optimal topologies after noise exclusion unambiguously supports parallel evolution of aggregated pollen in Periplocoideae (tetrads) and milkweeds (pollinia). Our phylogenomic approach has greatly advanced the resolution of one of the most perplexing radiations in Apocynaceae, providing the

  7. Reconstructive dosimetry and radiation doses evaluation of members of the public due to radiological accident in industrial radiography

    Lima, Camila Moreira Araujo de

    2016-01-01

    Radiological accidents have occurred mainly in the practices recognized as high risk radiological and classified by the IAEA as Categories 1 and 2, and highlighted the radiotherapy, industrial irradiators and industrial radiography. In Brazil, since there were five major cases in industrial radiography, which involved 7 radiation workers and 19 members of the public, causing localized radiation lesions on the hands and fingers. One of these accidents will be the focus of this work. In this accident, a "1"9"2Ir radioactive source was exposed for more than 8 hours in the workplace inside a company, exposing radiation workers, individuals of the public and people from the surrounding facilities, including children of a school. The radioactive source was also handled by a security worker causing severe radiation injuries in the hand and fingers. In this paper, the most relevant and used techniques of reconstructive dosimetry internationally are presented. To estimate the radiation doses received by exposed individuals in various scenarios of radiological accident in focus, the following computer codes were used: Visual Monte Carlo Dose Calculation (VMC), Virtual Environment for Radiological and Nuclear Accidents Simulation (AVSAR) and RADPRO Calculator. Through these codes some radiation doses were estimated, such as, 33.90 Gy in security worker's finger, 4.47 mSv in children in the school and 55 to 160 mSv for workers in the company during the whole day work. It is intended that this work will contribute to the improvement of dose reconstruction methodology for radiological accidents, having then more realist radiation doses. (author)

  8. The Effect of Thermal Radiation on Entropy Generation Due to Micro-Polar Fluid Flow Along a Wavy Surface

    Kuei-Hao Chang

    2011-09-01

    Full Text Available In this study, the effect of thermal radiation on micro-polar fluid flow over a wavy surface is studied. The optically thick limit approximation for the radiation flux is assumed. Prandtl’s transposition theorem is used to stretch the ordinary coordinate system in certain directions. The wavy surface can be transferred into a calculable plane coordinate system. The governing equations of micro-polar fluid along a wavy surface are derived from the complete Navier-Stokes equations. A simple transformation is proposed to transform the governing equations into boundary layer equations so they can be solved numerically by the cubic spline collocation method. A modified form for the entropy generation equation is derived. Effects of thermal radiation on the temperature and the vortex viscosity parameter and the effects of the wavy surface on the velocity are all included in the modified entropy generation equation.

  9. Evaluating noise abatement measures using strategic noise maps

    Borst, H.C.; Miedema, H.M.E.; Laan, W.P.N. van der; Lohman, W.J.A.

    2006-01-01

    Noise annoyance due to transportation is widespread in industrialized countries and in urban areas in the developing countries. The European Noise Directive (END) requires an assessment of the noise situation as well as the formulation of action plans for the reduction of the number of people

  10. Radiation

    2013-01-01

    The chapter one presents the composition of matter and atomic theory; matter structure; transitions; origin of radiation; radioactivity; nuclear radiation; interactions in decay processes; radiation produced by the interaction of radiation with matter

  11. Nutritional and metabolic changes due the abdominal radiation: experimental study; Alteracoes nutricionais e do metabolismo energetico na irradiacao abdominal: estudo experimental

    Mucerino, Donato R; Waitzberg, Dan L; Campos, Fabio G. de; Melo Auricchio, Maria T. de; Gama-Rodrigues, Joaquim J; Lima-Goncalves, Ernesto L [Sao Paulo Univ., SP (Brazil). Hospital das Clinicas. Div. de Clinica Cirurgica II

    1995-01-01

    In this study the effects on nutritional status and energetic metabolism due the abdominal irradiation were analysed. Adult male wistar rats (48), were divided in two groups Control (C) and radiated (R). The rats were maintained all time in metabolic cages. the study was done in two periods: period 1 begun at 0 day, were rats adapted to cages and oral diet, had food and water ad libitum. At the day four indirect calorimetric measurements were performed (calorimetry 1). At period 2, group R rats abdominal radiation at a 300 c Gy/day rate, for 5 consecutive days, and group C started a pair-feeding process linked individually to R rats and suffered application to simulated-irradiation. Two other calorimetric measurements (II,III) were performing during period 2. After radiation the last calorimetry was performed (IV). At sacrifice (day 14) blood was collected for determination of hemoglobin, hematocrit, albumin and transferrin. There were no statistical differences among groups C and R during period 1 (p < 0.05). Great reduction in food intake and weight variation were found in period 2, but weight loss was significantly higher in R rats. Nitrogen balance decrease in period 2, but without difference among the groups (p < 0.05). Serum albumin was significantly lower in R rats. Respiratory quotient decreased in both groups during period 2, but rats kept it lower (p < 0.05). The energy expenditure level decreased after radiation in group R. During period 2 total substrate oxidation decreased in R rats. Radiation decrease glucose and protein oxidation. In conclusion, in this study`s conditions, radiation produced malnutrition by reducing food intake by bringing weight loss, hypoalbuminemia and decrease nitrogen balance. Radiation was also responsible for a reduction of metabolism, by promoting the fall of energy expenditure. These changes are not only due the anorexia, undoubtful a main factor. (author). 60 refs., 3 figs., 4 tabs.

  12. Estimation of dose enhancement to soft tissue due to backscatter radiation near metal interfaces during head and neck radiothearpy - A phantom dosimetric study with radiochromic film

    Rajesh Ashok Kinhikar

    2014-01-01

    Full Text Available The objective of this study was to investigate the dose enhancement to soft tissue due to backscatter radiation near metal interfaces during head and neck radiotherapy. The influence of titanium-mandibular plate with the screws on radiation dose was tested on four real bones from mandible with the metal and screws fixed. Radiochromic films were used for dosimetry. The bone and metal were inserted through the film at the center symmetrically. This was then placed in a small jig (7 cm × 7 cm × 10 cm to hold the film vertically straight. The polymer granules (tissue-equivalent were placed around the film for homogeneous scatter medium. The film was irradiated with 6 MV X-rays for 200 monitor units in Trilogy linear accelerator for 10 cm × 10 cm field size with source to axis distance of 100 cm at 5 cm. A single film was also irradiated without any bone and metal interface for reference data. The absolute dose and the vertical dose profile were measured from the film. There was 10% dose enhancement due to the backscatter radiation just adjacent to the metal-bone interface for all the materials. The extent of the backscatter effect was up to 4 mm. There is significant higher dose enhancement in the soft tissue/skin due to the backscatter radiation from the metallic components in the treatment region.

  13. Quantum Noise

    Beenakker, C W J

    2005-01-01

    Quantum Noise is advertised as a handbook, and this is indeed how it functions for me these days: it is a book that I keep within hand's reach, ready to be consulted on the proper use of quantum stochastic methods in the course of my research on quantum dots. I should point out that quantum optics, the target field for this book, is not my field by training. So I have much to learn, and find this handbook to be a reliable and helpful guide. Crispin Gardiner previously wrote the Handbook of Stochastic Methods (also published by Springer), which provides an overview of methods in classical statistical physics. Quantum Noise, written jointly with Peter Zoller, is the counterpart for quantum statistical physics, and indeed the two books rely on each other by frequent cross referencing. The fundamental problem addressed by Quantum Noise is how the quantum dynamics of an open system can be described statistically by treating the environment as a source of noise. This is a general problem in condensed matter physics (in particular in the context of Josephson junctions) and in quantum optics. The emphasis in this book in on the optical applications (for condensed matter applications one could consult Quantum Dissipative Systems by Ulrich Weiss, published by World Scientific). The optical applications centre around the interaction of light with atoms, where the atoms represent the open system and the light is the noisy environment. A complete description of the production and detection of non-classical states of radiation (such as squeezed states) can be obtained using one of the equivalent quantum stochastic formulations: the quantum Langevin equation for the field operators (in either the Ito or the Stratonovich form), the Master equation for the density matrix, or the stochastic Schroedinger equation for the wave functions. Each formulation is fully developed here (as one would expect from a handbook), with detailed instructions on how to go from one to the other. The

  14. Radiative forcing due to greenhouse gas emission and sink histories in Finland and its future control potential

    Savolainen, I; Sinisalo, J; Pipatti, R [VTT Energy, Espoo (Finland)

    1996-12-31

    The effective atmospheric lifetimes of the greenhouse gases like carbon dioxide (CO{sub 2}),nitrous oxide (N{sub 2}O) and many of the CFCs are of the order of 100 years. Human activities, as an example GDP, very often change at rates of a few per cents per year,corresponding time constants of some tens of years. Also the forest ecosystems have time constants of this order. Even the human population of the globe is increasing by about two percent per year. Because so many natural and human-linked processes, which are relevant to global warming, have slow change rates of about same order, a time-dependent consideration of the greenhouse warming and its control can give useful information for the understanding of the problem. The objective of the work is to study the anthropogenic greenhouse gas emissions and sinks in Finland and their greenhouse impact as a function of time. The greenhouse impact is expressed in terms of radiative forcing which describes the perturbation in the Earth`s radiation budget. Radiative forcing allows a comparison of the impact of various greenhouse gases and their possible control options as a function of time. The idea behind the calculations is that Finland should in some way steer its share of the global radiative forcing and greenhouse effect. This presentation describes the calculation model REFUGE and the projects in which it has been used

  15. Radiative forcing due to greenhouse gas emission and sink histories in Finland and its future control potential

    Savolainen, I.; Sinisalo, J.; Pipatti, R. [VTT Energy, Espoo (Finland)

    1995-12-31

    The effective atmospheric lifetimes of the greenhouse gases like carbon dioxide (CO{sub 2}),nitrous oxide (N{sub 2}O) and many of the CFCs are of the order of 100 years. Human activities, as an example GDP, very often change at rates of a few per cents per year,corresponding time constants of some tens of years. Also the forest ecosystems have time constants of this order. Even the human population of the globe is increasing by about two percent per year. Because so many natural and human-linked processes, which are relevant to global warming, have slow change rates of about same order, a time-dependent consideration of the greenhouse warming and its control can give useful information for the understanding of the problem. The objective of the work is to study the anthropogenic greenhouse gas emissions and sinks in Finland and their greenhouse impact as a function of time. The greenhouse impact is expressed in terms of radiative forcing which describes the perturbation in the Earth`s radiation budget. Radiative forcing allows a comparison of the impact of various greenhouse gases and their possible control options as a function of time. The idea behind the calculations is that Finland should in some way steer its share of the global radiative forcing and greenhouse effect. This presentation describes the calculation model REFUGE and the projects in which it has been used

  16. Evaluation of the signal-to-noise ratio (SNR) in a CR system and establishment of RQR-M and RQA-M IEC reference radiations in mammography

    Rosado, Paulo H.G.; Nogueira, Maria S.; Dantas, Marcelino V.A.; Santana, Priscila do C.

    2009-01-01

    In this work, the radiation condition RQR-M e RQA-M of IEC were established in the Siemens Mammomat 3000 mammography equipment. The standard radiation condition are described in terms of: emitting target of molybdenum, percentage ripple not more that 4%, total filtration of 0,032 ± 0,002 mm of molybdenum and specific values of first half-value layer. The results show that the values of parameters were in the range that the IEC recommends. Only the RQAM-3 the value of CSR was not in agreement of the value recommend, and was necessary a additions of 0,1 mm Al in the x-ray tube. After this, the signal noise ratio (SNR) of de Computer radiography (CR) system was evaluated in the reference qualities of RQR-M e RQA-M. For SNR the RQR-M mode of exposure was done with both the 20 mAs and automatic one. To RQA-M the exposure was done with 100 mAs. The variations of the values of SNR were approximated 4%. The tests were done with CR model CR850 made from Kodak and 40 mm of PMMA. (author)

  17. Radiation induced ion currents in vacuum due to residual He and H, and their expected effect on insulating surfaces

    Hodgson, E.R.; Morono, A.; Gonzalez de Vicente, S.M.

    2006-01-01

    Ceramic insulators and windows in ITER will be subjected to bombardment by energetic hydrogen isotopes and helium as a consequence of ionization of the residual gas by gamma radiation and acceleration of the ions by the local electric fields. Most of the energy carried by these particles will be deposited at or very near the surface giving rise to possible electrical and optical degradation. Severe surface electrical degradation has recently been observed when oxide materials are implanted to low doses (10 15 ions/cm 2 ) with protons and alpha particles at temperatures between 50 and 450 o C. In order to estimate the relevance to fusion applications and hence the lifetime of ceramic insulators in ITER it is necessary to quantify possible ion currents generated in the residual gas by measuring radiation induced electrical conductivity for hydrogen isotopes and helium gases at low pressures and then perform experiments in which ceramic candidate materials are subjected to ion bombardment at representative currents and energies. To determine the magnitude of radiation generated ion currents, experiments have been carried out in a special gas chamber mounted in the beam line of a 2 MeV Van de Graaff electron accelerator, with the gases being irradiated through an 0.05 x 10 -3 m thick aluminium window with 1.8 MeV electrons. A guarded volume was defined between two parallel square copper plate electrodes separated by 1.5 x 10 -2 m. The experimental set-up permitted an electric field to be applied to the irradiated volume of gas, and the electric current flowing through the ionized gas to be measured. For these experiments the radiation beam was perpendicular to the electric field direction. In this way radiation induced conductivity for helium and hydrogen has been measured at pressures between about 1000 and 10 -3 mbar (10 -5 to 10 -1 Pa), radiation dose rates of 30 Gy/s and applied voltages up to 1500 volts. The radiation induced electrical currents for low pressure

  18. WE-AB-202-03: Quantifying Ventilation Change Due to Radiation Therapy Using 4DCT Jacobian Calculations

    Patton, T; Du, K; Bayouth, J; Christensen, G; Reinhardt, J

    2016-01-01

    Purpose: Four-dimensional computed tomography (4DCT) and image registration can be used to determine regional lung ventilation changes after radiation therapy (RT). This study aimed to determine if lung ventilation change following radiation therapy was affected by the pre-RT ventilation of the lung. Methods: 13 subjects had three 4DCT scans: two repeat scans acquired before RT and one three months after RT. Regional ventilation was computed using Jacobian determinant calculations on the registered 4DCT images. The post-RT ventilation map was divided by the pre-RT ventilation map to get a voxel-by-voxel Jacobian ratio map depicting ventilation change over the course of RT. Jacobian ratio change was compared over the range of delivered doses. The first pre-RT ventilation image was divided by the second to establish a control for Jacobian ratio change without radiation delivered. The functional change between scans was assessed using histograms of the Jacobian ratios. Results: There were significantly (p 10% expansion) showed a greater response (1.2% reduction/10 Gy). Contiguous high function regions > 1 liter occurred in 11 of 13 subjects. Conclusion: There is a significant change in regional ventilation following a course of radiation therapy. The change in Jacobian following RT is dependent both on the delivered dose and the initial ventilation of the lung tissue: high functioning lung has greater ventilation loss for equivalent radiation doses. Substantial regions of high function lung tissue are prevalent. Research support from NIH grants CA166119 and CA166703, a gift from Roger Koch, and a Pilot Grant from University of Iowa Carver College of Medicine

  19. Noise Pollution

    ... Regulated by EPA EPA or a designated Federal agency regulates noise sources, such as rail and motor carriers, low noise emission products, construction equipment, transport equipment, trucks, motorcycles, and the labeling of hearing ...

  20. Community noise

    Bragdon, C. R.

    Airport and community land use planning as they relate to airport noise reduction are discussed. Legislation, community relations, and the physiological effect of airport noise are considered. Noise at the Logan, Los Angeles, and Minneapolis/St. Paul airports is discussed.

  1. Overview of en route noise prediction using a integrated noise model

    2010-04-20

    En route aircraft noise is often ignored in aircraft noise modeling because large amounts of noise attenuation due to long propagation distances between the aircraft and the receivers on the ground, reduced power in cruise flight compared to takeoff ...

  2. Implementation of a Low Frame-Rate Protocol and Noise-Reduction Technology to Minimize Radiation Dose in Transcatheter Aortic Valve Replacement.

    Maccagni, Davide; Candilio, Luciano; Latib, Azeem; Godino, Cosmo; Chieffo, Alaide; Montorfano, Matteo; Colombo, Antonio; Azzalini, Lorenzo

    2018-05-01

    Limiting radiation exposure is necessary in radiological procedures. This study evaluates the impact of a radiological low frame-rate protocol in a standard angiographic system and the implementation of a noise-reduction technology (NRT) on patient radiation exposure during transcatheter aortic valve replacement (TAVR). Transfemoral TAVR procedures performed between February 2016 and February 2017 were analyzed according to two angiographic systems, Standard and NRT, and further divided in four subgroups: (1) Standard 15 frames per second (fps) with 15 fps for both fluoroscopy and cine acquisitions; (2) Standard 7.5 fps with 7.5 fps for both fluoroscopy and cine acquisitions; (3) NRT 15 fps with 15 fps for both fluoroscopy and cine acquisitions; and (4) NRT 7.5 fps with 15 fps for fluoroscopy and 7.5 fps for cine acquisitions. Study endpoints were kerma area product (KAP) and cumulative air kerma at interventional reference point (AK at IRP). Significant differences were found in KAP (153 Gy·cm² [IQR, 95-234 Gy·cm²] vs 78.3 Gy·cm² [IQR, 54.4-103.5 Gy·cm²]; Pfps and Standard 7.5 fps groups (184 Gy·cm² [IQR, 128-262 Gy·cm²] vs 106.8 Gy·cm² [IQR, 76.87-181 Gy·cm²] [P<.01] and 0.973 Gy [IQR, 0.642-1.786 Gy] vs 0.64 Gy [IQR, 0.489-0.933 Gy] [P<.01], respectively). The present study suggests that the low frame-rate protocol in Standard system and NRT implementation allows a marked reduction of patient radiation exposure in TAVR procedures.

  3. Investigation of the present management status of calibration source based on the law concerning prevention of radiation hazards due to radioisotopes

    Takahashi, Yasuyuki; Igarashi, Hiroshi; Hirano, Kunihiro; Kawaharada, Yasuhiro; Igarashi, Hitoshi; Murase, Ken-ya; Mochizuki, Teruhito

    2007-01-01

    An amendment concerning the enforcement of the law on the prevention of radiation hazards due to radioisotopes, etc., and the medical service law enforcement regulations were promulgated on June 1, 2005. This amendment concerned international basic safety standards and the sealing of radiation sources. Sealed radiation sources ≤3.7 MBq, which had been excluded from regulation, were newly included as an object of regulation. Investigation of the single photon emission computed tomography (SPECT) system instituted in hospitals indicated that almost all institutions adhere to the new amendment, and the calibration source, the checking source, etc., corresponding to this amendment were maintained appropriately. Any institutions planning to return sealed radioisotopes should refer to this report. (author)

  4. Radiation hygiene survey on human and cattle in Fukushima prefecture no health hazards due to low doses

    Takada, Jun

    2012-01-01

    Radiation hygiene survey has been conducted about Fukushima Dai-Ichi nuclear power station disaster caused by tsunami in the East Japan earthquake area on March 11 th 2011. Our surveys reveal that a public annual dose is 10 mSv following low-dose and health hazards shall not be concluded by the methods of in situ dose evaluation. This study has been focused on internal dosimetries of iodine-131 in thyroid and of cesium-134, 137 in whole body. Especially we continuously have been studing radiation hygiene on cattle livestock in Namie town within 20 km zone around the Fukushima Daiichi nuclear power station, and found no problem for the recovery. (author)

  5. Changes in lipids and in the sensoric properties of foods due to combined preservation (thermosterilization + ionizing radiation)

    Rajniakova, A.; Sorman, L.; Hozova, B.; Salkova, Z.

    1989-01-01

    Chemical changes in lipids were examined in ''Beef with Cauliflower'' model samples prepared by combined preservation, consisting in thermosterilization at 121 degC for 30 min and exposure to ionizing radiation doses of 3 to 5 kGy immediately after preparation and during storage (115 days at 20±2 degC). The acid, peroxide and carbonyl values increased with increasing radiation dose. The sensoric characteristics of the samples were examined as well, and no changes were observed in the 115 days of storage. Various preservation modes were tested, and the combination of steady sterilization at 121 degC for 30 min with subsequent exposure to a 5 kGy dose emerged as optimal; the nutrition value of the beef was higher and energy demands lower than in the application of conventional thermosterilization. (author). 6 figs., 3 tabs., 10 refs

  6. Prospective study of total cholesterol amount in the blood of the persons exposed to ionizing radiation due to Chernobyl accident

    Chobot'ko, G.M.

    1998-01-01

    The blood of the men aged 20-59 residing in Kyiv after the accident and that of the participants of the accident clean-up aged 25-55 has been studying for 10 years. The nature of the observed changes in blood cholesterol amount is atherogenic, which should be taken into account when taking preventive and therapeutic measures in the persons exposed to different dosed of ionizing radiation

  7. Individual radiation doses due to atmospheric diffusion of cesium-137 in connection with land transport of radioactive material

    Wilkens, A.-B.

    1979-02-01

    The radiological consequences of a discharge of Cs-137 into the air in connection with the tranportation on land of radioactive material. The accident is supposed to take place during the vegetation period. Possible exposure ways are mapped out and radiation doses are calculated for acute and chromic phases, respectively. The highest doses were obtained by the consumption of food which has been produced on contaminated areas during the year of discharge. (E.R.)

  8. Radiation-enhanced short channel effects due to multi-dimensional influence from charge at trench isolation oxides

    Youk, G.U.; Khare, P.S.; Schrimpf, R.D.; Massengill, L.W.; Galloway, K.F.

    1999-01-01

    Radiation enhanced drain induced barrier lowering (DIBL) was experimentally observed and verified by 3-D simulations for submicron devices with trench isolation oxides. Submicron MOSFETs with shallow trench isolation were exposed to total-ionizing-dose radiation. Prior to irradiation, the devices exhibited near-ideal current-voltage characteristics, with no significant short-channel effects for as-drawn gate lengths of 0.4 microm. Following irradiation, the off-state leakage current increased significantly for total doses above about 650 krad(SiO 2 ). In addition, the irradiated devices exhibited DIBL that increased the drain current by 5--10x for a gate length of 0.4 microm (the nominal minimum gate length for this process) and much more for slightly shorter devices (0.35 microm). The increase in the off-state leakage current and the accompanying DIBL are shown to be associated with a parasitic field-effect transistor that is present at the edge of the shallow trench. Three-dimensional simulations are used to illustrate the effect. Simulations show that trapped charge at the trench sidewalls enhance the DIBL by depleting the edges of the channel. Radiation-induced charge may decrease the effectiveness of short-channel engineering

  9. Radiation dermatitis due to catheter ablation used in the treatment of arrhythmia. A report of two cases

    Nagano, Tohru; Kosaka, Hiroshi; Shimoura, Shinichi; Tsuru, Kenta; Yamagami, Nao; Ikeda, Tetsuya; Nishigori, Chikako; Yoshida, Akihiro

    2004-01-01

    We report 2 cases of radiation dermatitis caused by catheter ablation for treatment of atrial fibrillation resisitant to conventional therapies. Case 1, 50-year-old male underwent pulmonary veins ablation for treatment of atrial fibrillation. Cumulative fluoroscopic imaging time of 370 min was required. Case 2, 74-year-old female also underwent pulmonary veins ablation for treatment of atrial fibrillation. Cumulative fluoroscopic imaging time of 550 min was required. Since dose rate used for imaging is 20∼80 mGy/min, accumulated skin doses were estimated as 7.4∼29.6 Gy and 5.6∼22.4 Gy, respectively. Two weeks after their last ablation, brown, painful macule and plaque appeared on the outer side of their right upper arms. To our knowledge, the risk of overexposure to X-ray in cases of PTCA (percutaneous transluminal coronary angioplasty) for ischemic heart diseases has been well known, but little is known about the risk of catheter ablation. The location of radiation dermatitis caused by catheter ablation (CA) is rather different from that of PTCA. It is critical for cardiologists and dermatologists to observe and find the symptoms of acute radiation dermatitis in order to avoid repeated overexposure to X-ray. (author)

  10. WE-AB-202-03: Quantifying Ventilation Change Due to Radiation Therapy Using 4DCT Jacobian Calculations

    Patton, T; Du, K; Bayouth, J [University of Wisconsin, Madison, WI (United States); Christensen, G; Reinhardt, J [University of Iowa, Iowa City, IA (United States)

    2016-06-15

    Purpose: Four-dimensional computed tomography (4DCT) and image registration can be used to determine regional lung ventilation changes after radiation therapy (RT). This study aimed to determine if lung ventilation change following radiation therapy was affected by the pre-RT ventilation of the lung. Methods: 13 subjects had three 4DCT scans: two repeat scans acquired before RT and one three months after RT. Regional ventilation was computed using Jacobian determinant calculations on the registered 4DCT images. The post-RT ventilation map was divided by the pre-RT ventilation map to get a voxel-by-voxel Jacobian ratio map depicting ventilation change over the course of RT. Jacobian ratio change was compared over the range of delivered doses. The first pre-RT ventilation image was divided by the second to establish a control for Jacobian ratio change without radiation delivered. The functional change between scans was assessed using histograms of the Jacobian ratios. Results: There were significantly (p < 0.05) more voxels that had a large decrease in Jacobian ratio in the post-RT divided by pre-RT map (15.6%) than the control (13.2%). There were also significantly (p < .01) more voxels that had a large increase in Jacobian ratio (16.2%) when compared to control (13.3%). Lung regions with low function (<10% expansion by Jacobian) showed a slight linear reduction in expansion (0.2%/10 Gy delivered), while high function regions (>10% expansion) showed a greater response (1.2% reduction/10 Gy). Contiguous high function regions > 1 liter occurred in 11 of 13 subjects. Conclusion: There is a significant change in regional ventilation following a course of radiation therapy. The change in Jacobian following RT is dependent both on the delivered dose and the initial ventilation of the lung tissue: high functioning lung has greater ventilation loss for equivalent radiation doses. Substantial regions of high function lung tissue are prevalent. Research support from NIH

  11. Control of persistent vesical bleeding due to radiation cytitis by intravesical application of 15(s) 15-methyl prostaglandin F2-alpha

    Hemal, A.K.; Praveen, B.V.; Sankaranarayanan, A.; Vaidyanathan, S.

    1989-01-01

    A 45 year old female who received radiotherapy for stage II-B uterine cervical cancer four and half years ago, presented with persistent hematuria due to radiation cystitis. 15(S) 15-methyl prostaglandin F 2 -alpha (1 mg in 100 ml of normal saline) was instilled into the bladder daily for two days. The severity of bleeding decreased considerably. However, significant hematuria recurred 19 days later which continued despite bladder irrigation with normal saline, 1 mg of 15(S) 15-Me PGF 2 alpha mixed with hydroxyethyl cellulose gel to a volume of 10 ml was then instilled into the urinary bladder daily for three days and macroscopic hematuria ceased. Urinary frequency and urgency were the side effects which lasted for ten days. There has been no recurrence of macroscopic hematuria during the five months followup. In conclusion, 15(S) 15-Me PGF 2 - alpha may be administered intravesically to control moderate hematuria due to radiation cystitis. (author). 5 refs

  12. Fast calculator for X-ray emission due to Radiative Recombination and Radiative Electron Capture in relativistic heavy-ion atom collisions

    Herdrich, M. O.; Weber, G.; Gumberidze, A.; Wu, Z. W.; Stöhlker, Th.

    2017-10-01

    In experiments with highly charged, fast heavy ions the Radiative Recombination (RR) and Radiative Electron Capture (REC) processes have significant cross sections in an energy range of up to a few GeV / u . They are some of the most important charge changing processes in collisions of heavy ions with atoms and electrons, leading to the emission of a photon along with the formation of the ground and excited atomic states. Hence, for the understanding and planning of experiments, in particular for X-ray spectroscopy studies, at accelerator ring facilities, such as FAIR, it is crucial to have a good knowledge of these cross sections and the associated radiation characteristics. In the frame of this work a fast calculator, named RECAL, for the RR and REC process is presented and its capabilities are demonstrated with the analysis of a recently conducted experiment at the Experimental Storage Ring (ESR) at the GSI Helmholtz Center for Heavy Ion Research in Darmstadt, Germany. A method is presented to determine unknown X-ray emission cross sections via normalization of the recorded spectra to REC cross sections calculated by RECAL.

  13. The efficiency of tyrosine kinase inhibitor therapy in patients with chronic myeloid leukemia exposed to ionizing radiation due to the Chornobyl nuclear power plant accident

    Dmitrenko, Yi.V.; Fedorenko, V.G.; Shlyakhtichenko, T.Yu.; And Others

    2014-01-01

    Additional chromosomal abnormalities as well as special pattern of BCR/ABL transcripts were not revealed in CML patients exposed to ionizing radiation. Complete cytogenetic response (CCR) was shown in 50 and 48.5 % of patients from study and comparison group, respectively. Major molecular response (MMR) was achieved in 20 % of patients with radiation exposure in anamnesis and in 27.6 % of patients from comparison group. The vast majority of CCR and MMR was reached in patients with the pretreatment term up to 6 months, when imatinib was used as a first line therapy. There were less cases of primary imatinib resistance in the same group of patients. In CML patients who had a history of radiation exposure, secondary resistance developed more frequently than in the comparison group and was 25 %. Laboratory monitoring based on the registration of CCR and MMR demonstrated high efficiency of TKI in the CML treatment of patients, exposed due to Chornobyl accident. Extension of pretreatment term leads to the loss of TKI therapy efficiency and increases the likelihood of primary resistance. CML patients exposed to ionizing radiation develop secondary resistance more often than CML patients without radiation exposure in anamnesis

  14. Noise pollution from wind turbine gears loudness of structural noise sources related to gears

    Crone, A.

    1995-04-01

    The purpose of the project has been to develop a method for determination of the structure-borne noise source strength of the gearbox in a typical modern Danish wind turbine construction, with special reference to the tonal noise emission form the turbines. Through study and evaluation of eight potential methods, a simple method has ben formulated. The method is based on measurements of the free vibration velocity level on the gearbox in a load test bed. The relation between this source strength measure and the gearbox related noise from wind turbines has been documented by measurements made during the project together with earlier measurements. The method is intended as a tool for the wind turbine manufacturer, for control of the gearbox related noise from the wind turbines, due to structure-borne noise from the gearbox. It may be used for preparation of specifications to the gearbox manufacturer on test procedure and acceptable source strength levels. Also, it may be used for evaluation of the transmission and radiation of gearbox related noise, for example in order to uncover weaknesses in a prototype turbine. Suggestions for adaptation and evolution of the method has been given, thereby improving the strength of the method for the individual wind turbine manufacturer. (au) 19 refs

  15. Multi-Model Simulations of Aerosol and Ozone Radiative Forcing Due to Anthropogenic Emission Changes During the Period 1990-2015

    Myhre, Gunnar; Aas, Wenche; Ribu, Cherian; Collins, William; Faluvegi, Gregory S.; Flanner, Mark; Forster, Piers; Hodnebrog, Oivind; Klimont, Zbigniew; Lund, Marianne T.

    2017-01-01

    Over the past few decades, the geographical distribution of emissions of substances that alter the atmospheric energy balance has changed due to economic growth and air pollution regulations. Here, we show the resulting changes to aerosol and ozone abundances and their radiative forcing using recently updated emission data for the period 1990-2015, as simulated by seven global atmospheric composition models. The models broadly reproduce large-scale changes in surface aerosol and ozone based on observations (e.g. 1 to 3 percent per year in aerosols over the USA and Europe). The global mean radiative forcing due to ozone and aerosol changes over the 1990-2015 period increased by 0.17 plus or minus 0.08 watts per square meter, with approximately one-third due to ozone. This increase is more strongly positive than that reported in IPCC AR5 (Intergovernmental Panel on Climate Change Fifth Assessment Report). The main reasons for the increased positive radiative forcing of aerosols over this period are the substantial reduction of global mean SO2 emissions, which is stronger in the new emission inventory compared to that used in the IPCC analysis, and higher black carbon emissions.

  16. Attenuation of radiation-induced DNA damage due to paracrine interactions between normal human epithelial and stromal cells

    Saenko, V.A.; Nakazawa, Yu.; Rogounovitch, T.I.; Suzuki, K.; Mitsutake, N.; Matsuse, M.; Yamashita, S.

    2007-01-01

    Complete text of publication follows. Objective: Developmentally, every tissue accommodates different types of cells, such as epitheliocytes and stromal cells in parenchymal organs. To better understand the complexity of radiation response, it is necessary to evaluate possible cross-talk between different tissue components. This work was set out to investigate reciprocal influence of normal human epithelial cells and fibroblasts on the extent of radiation-induced DNA damage. Methods: Model cultures of primary human thyrocytes (PT), normal diploid fibroblasts (BJ), PT/BJ cell co-culture and conditioned medium transfer were used to examine DNA damage in terms of γ-H2AX foci number per cell or by Comet assay after exposure to different doses of γ-rays. Results: In co-cultures, the kinetics of γ-H2AX foci number change was dose-dependent and similar to that in individual PT and BJ cultures. The number of γ-H2AX foci in co-cultures was significantly lower (∼25%) in both types of cells comparing to individual cultures. Reciprocal conditioned medium transfer to individual counterpart cells prior to irradiation resulted in approximately 35% reduction in the number γ-H2AX foci at 1 Gy and lower doses in both PT and BJ demonstrating the role of paracrine soluble factors. Comet assay corroborated the results of γ-H2AX foci counting in conditioned medium transfer experiments. In contrast to medium conditioned on PT cells, conditioned medium collected from several human thyroid cancer cell lines failed to establish DNA-protected state in BJ fibroblasts. In its turn, medium conditioned on BJ cells did not change the extent of radiation-induced DNA damage in cancer cell lines tested. Conclusion: The results imply the existence of a network of soluble factor-mediated paracrine interactions between normal epithelial and stromal cells that could be a part of natural mechanism by which cells protect DNA from genotoxic stress.

  17. Two-stream cyclotron radiative instabilities due to the marginally mirror-trapped fraction for fustion alphas in tokamaks

    Arunasalam, V.

    1995-07-01

    It is shown here that the marginally mirror-trapped fraction of the newly-born fusion alpha particles in the deuterium-tritium (DT) reaction dominated tokamak plasmas can induce a two-stream cyclotron radiative instability for the fast Alfven waves propagating near the harmonics of the alpha particle cyclotron frequency {omega}{sub c{alpha}}. This can explain both the experimentally observed time behavior and the spatially localized origin of the fusion product ion cyclotron emission (ICE) in TFTR at frequencies {omega} {approx} m{omega}{sub c{alpha}}.

  18. Dose contributions due to radiation scattered by air (skyshine) in the case of X-ray machines

    Sahre, P.; Kaden, M. [Verein fuer Kernverfahrenstechnik und Analytik Rossendorf e.V. (VKTA), Dresden (Germany). Nuclear Engineering and Analytics Rossendorf; Schoenmuth, T.; Naumann, B. [Hochschule fuer Technik, Wirtschaft und Sozialwesen Zittau/Goerlitz, Zittau (Germany); Pawelke, J. [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany); Technische Univ. Dresden (Germany); OncoRay, Dresden (Germany); Reichelt, U. [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany)

    2012-06-15

    Radiation transport simulations had to be done in preparation of operation of the X-ray tube ISOVOLT 320 kV/13mA in a special laboratory. At first simulation was done without shielding the roof of the laboratory, showing a dose rate maximum of more than 100 mSv/h. This dose rate results in a skyshine dose rate of at most 2 {mu}Sv/h in the surrounding of the building without shielding the roof. For similar geometries the skyshine is negligible for dose rates at the unshielded roof of less than 3 mSv/h (exclusion area). (orig.)

  19. Monitoring the radiation consequences due to the disaster at the Chernobyl nuclear facility from April 28 to June 12, 1986

    Andrasi, A.; Beleznay, E.; Deme, S.

    1986-07-01

    Environmental radiation measurements were carried out by the Health Physics Department of the Central Research Institute for Physics in cooperation with the Hungarian Civil Defence Organization in the title period in Hungary. The following data were measured: activity concentration of radioaerosols and radioactive iodine in air, fallout activity, in situ gamma spectroscopy to estimate ground surface contamination, gamma dose rate, activity concentration in milk, incorporated radionuclides, activities of 131 I in thyroid gland and of 103 Ru in lung, whole-body activities of 137 Cs and 134 Cs. (R.P.)

  20. Measurement of the environmental radiation dose due to the accident at the Fukushima Daiichi Nuclear Power Plant

    Yamamoto, Tomoaki; Muroi, Kenzo; Maruyama, Sumito; Koike, Takahisa; Matsuda, Marina; Katsumata, Kenichiro

    2013-01-01

    On March 11, 2011, an undersea megathrust earthquake caused a tsunami that inflicted serious damage to the Fukushima Daiichi Nuclear Power Plant (FDNPP). On March 12, 2011, we began measuring environmental radiation doses and identifying fission product radionuclides at the International University of Health and Welfare (IUHW). The purpose of this investigation is to estimate the external exposure dose of fission products from FDNPP. Measurements were performed between March 12 and August 31, 2011. A NaI(Tl) scintillation survey meter was used to measure the environmental radiation dose, and air dust samplers and a NaI(Tl) scintillation spectrum analyzer were used to identify radionuclides in the atmosphere and soil. For estimating external doses, three lifestyle groups were considered viz. students or office workers, business persons, and farmers or construction workers. Increasing doses were detected on March 15 around noon, and the doses peaked on March 16. Post-peak, the doses decreased exponentially and became stable after two months. Immediately after the accident, some fission product radionuclides were detected in the atmosphere and in the soil samples. Almost no radionuclides were detected in the atmosphere approximately one month after the first analysis; although the radiation was decaying, radionuclides were detected in the soil and were isolated. The external dose varied with the supposed lifestyle; assuming that the abundance ratio of Cs-134 to Cs-137 was 1:1, the annual external doses for the considered lifestyles were 1.069 mSv for students or office workers, 1.672 mSv for business persons, and 2.044 mSv for farmers or construction workers. These doses are sufficiently small so that most residents including children, living near IUHW, would not be affected. Further investigation of the internal exposure is necessary for a better estimate of the effective doses. External exposure to fission product radionuclides is within safe levels, and while

  1. Two-stream cyclotron radiative instabilities due to the marginally mirror-trapped fraction for fustion alphas in tokamaks

    Arunasalam, V.

    1995-07-01

    It is shown here that the marginally mirror-trapped fraction of the newly-born fusion alpha particles in the deuterium-tritium (DT) reaction dominated tokamak plasmas can induce a two-stream cyclotron radiative instability for the fast Alfven waves propagating near the harmonics of the alpha particle cyclotron frequency ω cα . This can explain both the experimentally observed time behavior and the spatially localized origin of the fusion product ion cyclotron emission (ICE) in TFTR at frequencies ω ∼ mω cα

  2. A simple method to compute the change in earth-atmosphere radiative balance due to a stratospheric aerosol layer

    Lenoble, J.; Tanre, D.; Deschamps, P. Y.; Herman, M.

    1982-01-01

    A computer code was developed in terms of a three-layer model for the earth-atmosphere system, using a two-stream approximation for the troposphere and stratosphere. The analysis was limited to variable atmosphere loading by solar radiation over an unperturbed section of the atmosphere. The scattering atmosphere above a Lambertian ground layer was considered in order to derive the planar albedo and the spherical albedo. Attention was given to the influence of the aerosol optical thickness in the stratosphere, the single scattering albedo and asymmetry factor, and the sublayer albedo. Calculations were performed of the zonal albedo and the planetary radiation balance, taking into account a stratospheric aerosol layer containing H2SO4 droplets and volcanic ash. The resulting ground temperature disturbance was computed using a Budyko (1969) climate model. Local decreases in the albedo in the summer were observed in high latitudes, implying a heating effect of the aerosol. An accompanying energy loss of 23-27 W/sq m was projected, which translates to surface temperature decreases of either 1.1 and 0.45 C, respectively, for background and volcanic aerosols.

  3. Behavior of the physician in the case of fetal exposition to ionising radiations due to medical indication

    Leppin, W.

    1982-01-01

    The 3-tier Concept presented here should contribute to the formation of a consensus of opinion concerning the hazards of radiation dose to pregnant women. It is applicable in the first instance to those directly involved, namely radiologists, gynaecologists and pregnant women. The physician-in-charge should be be responsible for all treatment up to the dose of 20 Cy, which is in one opinion a harmless level of in-utero exposure. Even if errors in dose estimation are taken into account, there exist sufficient safety reserves for the protection of the fetus. Omission of enquiry would mean that the feelings of insecurity, fear and anxiety in pregnant women would no longer arise. This procedure could also make a positive and objective contribution towards the lessening of fear of radiation in other areas. In addition it is our view that, given this sole responsibility, physicians would become more aware of and concerned with the problems of radiological protection. In no way should this concept make light of clearly present hazards. (orig.) [de

  4. C → T mutagenesis and γ-radiation sensitivity due to deficiency in the Smug1 and Ung DNA glycosylases

    An, Qian; Robins, Peter; Lindahl, Tomas; Barnes, Deborah E

    2005-01-01

    The most common genetic change in aerobic organisms is a C:G to T:A mutation. C → T transitions can arise through spontaneous hydrolytic deamination of cytosine to give a miscoding uracil residue. This is also a frequent DNA lesion induced by oxidative damage, through exposure to agents such as ionizing radiation, or from endogenous sources that are implicated in the aetiology of degenerative diseases, ageing and cancer. The Ung and Smug1 enzymes excise uracil from DNA to effect repair in mammalian cells, and gene-targeted Ung−/− mice exhibit a moderate increase in genome-wide spontaneous mutagenesis. Here, we report that stable siRNA-mediated silencing of Smug1 in mouse embryo fibroblasts also generates a mutator phenotype. However, an additive 10-fold increase in spontaneous C:G to T:A transitions in cells deficient in both Smug1 and Ung demonstrates that these enzymes have distinct and nonredundant roles in suppressing C → T mutability at non-CpG sites. Such cells are also hypersensitive to ionizing radiation, and reveal a role of Smug1 in the repair of lesions generated by oxidation of cytosine. PMID:15902269

  5. Contribution to the G0 experiment about parity violation: calculation and simulation of radiative corrections, study of the background noise

    Guler, H.

    2003-12-01

    In the framework of quantum chromodynamics, the nucleon is made of three valence quarks surrounded by a sea of gluons and quark-antiquark pairs. Only the only lightest quarks (u, d and s) contribute significantly to the nucleon properties. In G 0 we use the property of weak interaction to violate parity symmetry, in order to determine separately the contributions of the three types of quarks to nucleon form factors. The experiment, which takes place at Thomas Jefferson laboratory (USA), aims at measuring parity violation asymmetry in electron-proton scattering. By doing several measurements at different momentum squared of the exchanged photons and for different kinematics (forward angle when the proton is detected and backward angle it will be the electron) will permit to determine separately strange quarks electric and magnetic contributions to nucleon form factors. To extract an asymmetry with small errors, it is necessary to correct all the beam parameters, and to have high enough counting rates in detectors. A special electronics was developed to treat information coming from 16 scintillator pairs for each of the 8 sectors of the G 0 spectrometer. A complete calculation of radiative corrections has been done and Monte Carlo simulations with the GEANT program has permitted to determine the shape of the experimental spectra including inelastic background. This work will allow to do a comparison between experimental data and theoretical calculations based on the Standard Model. (author)

  6. Far-field self-focusing and -defocusing radiation behaviors of the electroluminescent light sources due to negative refraction.

    Yin, Yu-Feng; Lin, Yen-Chen; Tsai, Tsung-Han; Shen, Yi-Chun; Huang, Jianjang

    2013-01-15

    In recent years, researchers have demonstrated negative refraction theoretically and experimentally by pumping optical power into photonic crystal (PhC) or waveguide structures. The concept of negative refraction can be used to create a perfect lens that focuses an object smaller than the wavelength. By inserting two-dimensional PhCs into the peripheral of a semiconductor light emitting structure, this study presents an electroluminescent device with negative refraction in the visible wavelength range. This approach produces polarization dependent collimation behavior in far-field radiation patterns. The modal dispersion of negative refraction results in strong group velocity modulation, and self-focusing and -defocusing behaviors are apparent from light extraction. This study further verifies experimental results by using theoretic calculations based on equifrequency contours.

  7. Assessment of radiation dose due to fluoroscopic procedures in patients at some selected facilities in the Greater Accra Region, Ghana

    Gyasi, E.

    2013-07-01

    Radiation doses to 182 adults patients who underwent barium enema, barium meal, barium swallow, myelogram, hysterosalpingography and urethrogram examination collectively at facilities A and B were investigated. Radiation dose was measured using kerma-area-product (KAP) meter. From the KAP readings, patient's data and other relevant information from the control console, effective dose and selective organ doses were estimated using Monte Carlo program software (PCXMC version 1.5). Quality control tests performed on the two fluoroscopy machines were found to be within the acceptance criteria. Mean effective doses were found to be 8.45 ± 0.38mSv, 7.628 ± 0.42 mSv, 1.46 ± 0.13 mSv, 2.02 ± 0.16 mSv, 0.32 ± 0.03 mSv for barium enema, barium meal, barium swallow, myelogram and urethrogram examinations respectively at Facility A. At Facility B the mean effective dose were found to be 4.12 ± 0.15 mSv, 1.83 ± 0.10 mSv, 0.81 ± 0.04 mSv, 0.53 ± 0.036 mSv and 0.27 ± 0.01 mSv for barium enema, barium meal, barium swallow, myelogram, hysterosalpingography and urethrogram examination respectively. Thymus received the highest organ dose of 29.19± 2.07mGy during barium meal studies at Facility A of all the procedures in the two hospitals. Magnitude of organ doses was observed to to be in relation with the closeness to or in the direction of the primary beam of radiation. Organ and effective doses from Facility A were relatively higher than those from Facility B in comparison by a factor of a about 2 with the exception of the barium meal examination at Facility A which was by a factor of about 4. The measured KAP readings fro the two facilities were below the international accepted reference levels with the exception of barium meal examination at Facility A which recorded a higher value of 25.96 ± 1.83 Gy.cm 2 as compared to ICRP (2001) reference value of 25 Gy.cm 2 . Longer radiation beam on time, high number of radiographs taken per patient, wide exposure beam area on

  8. H(10) due to radiation scattered in a 6 MV Linac for tomotherapy; H*(10) debida a la radiacion dispersada en un LINAC de 6 MV para tomoterapia

    Vega C, H. R.; Esparza H, A. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98060 Zacatecas, Zac. (Mexico); Garcia R, M. G. [Instituto Tecnologico y de Estudios Superiores de Monterrey, Campus Zacatecas, Calz. Pedro Coronel 16, Dependencias Federales, 98600 Guadalupe, Zacatecas (Mexico); Reyes R, E. [Universidad de Guanajuato, Campus Leon, Division de Ciencias e Ingenierias, Loma del Bosque 103, Col. Lomas del Campestre, 37150 Leon, Guanajuato (Mexico); Hernandez A, L. [Consejo Nacional de Ciencia y Tecnologia, CIBNOR, Mar Bermejo 195, Col. Playa Palo de Santa Rita, 23090 La Paz, Baja California Sur (Mexico); Rivera, T., E-mail: fermineutron@yahoo.com [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Calz. Legaria 694, Col. Irrigacion, 11500 Ciudad de Mexico (Mexico)

    2017-10-15

    In order to determine the environmental equivalent dose (H(10)), due to the radiation that is dispersed over the body of a patient, 100 thermoluminescent dosimeters (TLD) around 6 MV TomoLINAC were used. The characteristics of the tomotherapy have the disadvantage that the shielding of the bunker increases considerably and for its design validated parameters are used for the conventional Linacs. In order to determine H(10) due to scattered radiation, measurements were made in the vicinity of the isocenter, while the 6 MeV photon beam was applied on a phantom. Also, TLDs were placed on the walls of the bunker that remained for 7 days, where approximately 50 patients were treated per day. At points close to the isocenter, the H(10) has an angular distribution caused by the phantom shape. In the bunker walls the highest H(10) was observed in the primary barriers. In the labyrinth, the impact of the scattered radiation was observed when measuring a greater value of the environmental equivalent dose in the wall furthest from the isocenter compared to the point located closest to it. (Author)

  9. Radiation dose to the thyroid due to incorporation of iodine isotopes: Age dependence and reliability of dose factors

    Henrichs, K.; Mueller-Brunecker, G.; Paretzke, H.G.

    1983-08-01

    This is the first time that dose factors are published in the literature, together with an assessment of their reliability with regard to the quantification of the dose received by the population in the Federal Republic of Germany due to incorporation if iodine isotopes, taking into account the given age distribution among the population. The calculation of dose factors is based on the latest dosimetric and metabolic models issued by the ICRP (ICRP-30), and the impact of the various parameters and their variability on the accuracy of dose factor determination is assessed. The procedure followed to calculate the dose due to incorporation on the basis of metabolic models (ICRP 1978 and ICRP 1979) is explained. The main data (such as half life, mean frequency per decay, mean energy in keV) are given for I-123, I-125, I-129, I-131, I-132, I-133, I-134, and I-135 (ICRP-30) and listed in tables. (orig./HP) [de

  10. Radiation-induced heart disease due to intrathonacic tumor radiotherapy of a single dose to the rabbits' heart

    Zhou Weibing; Feng Yan; Chen Jiayi; Luo Quanyong

    2007-01-01

    Objective: To observe the changes of radiation-induced heart disease (RIHD) in the rabbits irradiated in clinical related dose, and to evaluate the apoptosis and hypoxia in the irradiated heart by the new scintigraphic agents of 99 Tc m -HL91 and 99 Tc m -Annexin V of heart SPECT. Methods: Tenty-four New Zealand white rabbits 4-month old and 2-3 kg by weight were divided into two groups. Group 1 (clinical related dose group): 16 irradiated by a single close from 0 to 18 Gy. Group 2 (high dose group): 8 irradiated dose from 22 to 80 Gy. The serum cTnI/CKMB, ECG, and heart SPECT(using 99 Tc m -MIBI, 99 Tc m -HL91 and 99 Tc m -Annexin V as agents) were detected before and after irradiation. The animals were followed for 5 months. Then biopsy of rabbit heart was performed and pathologic examination was made by H.E. stain. Results: In the 16 rabbits of clinical related dose group, none died of RIHD. Whereas 2 rabbits died of RIHD in the high dose group. One died of myocardial infarction and the other of congestive heart failure. According to the Stewart introduced heart lesion grading system, of the clinical close ann, there were moderate in 1 rabbit, minimal in 14; and of the high dose ann, it was severe in 2, marked in 1, moderate in 5. The parallel relation was observed between the ECG results and the pathological changes (χ 2 =0.08, P=0.771). Serum value of cTnI, was elevated at the 12th hour after irradiation reaching the peak and maintained for 4 months. However, it came down in the 5th month. The difference of serum cTnI value before and after radiation was statistically significant. Myocardial perfusion scintigraphy tested by heart SPECT ( 99 Tc m -MIBI) showed defects was present in all irradiated rabbits. The relationship between the defects and radiation dose or between the defects and the real RIHD was uncertain. The SPECT images displayed that 99 Tc m -HL91 and 99m Tc-Annexin V did not accumulate in the irradiated heart. Conclusions: No serious damage is

  11. Radiation Dose Estimates in Indian Adults in Normal and Pathological Conditions due to 99Tcm-Labelled Radiopharmaceuticals

    Tyagi, K.; Jain, S.C.; Jain, P.C.

    2001-01-01

    ICRP Publications 53, 62 and 80 give organ dose coefficients and effective doses to ICRP Reference Man and Child from established nuclear medicine procedures. However, an average Indian adult differs significantly from the ICRP Reference Man as regards anatomical, physiological and metabolic characteristics, and is also considered to have different tissue weighting factors (called here risk factors). The masses of total body and most organs are significantly lower for the Indian adult than for his ICRP counterpart (e.g. body mass 52 and 70 kg respectively). Similarly, the risk factors are lower by 20-30% for 8 out of the 13 organs and 30-60% higher for 3 organs. In the present study, available anatomical data of Indians and their risk factors have been utilised to estimate the radiation doses from administration of commonly used 99 Tc m -labelled radiopharmaceuticals under normal and certain pathological conditions. The following pathological conditions have been considered for phosphates/phosphonates - high bone uptake and severely impaired kidney function; IDA - parenchymal liver disease, occlusion of cystic duct, and occlusion of bile duct; DTPA - abnormal renal function; large colloids - early to intermediate diffuse parenchymal liver disease, intermediate to advanced parenchymal liver disease; small colloids - early to intermediate parenchymal liver disease, intermediate to advanced parenchymal liver disease; and MAG3 - abnormal renal function, acute unilateral renal blockage. The estimated 'effective doses' to Indian adults are 14-21% greater than the ICRP value from administration of the same activity of radiopharmaceutical under normal physiological conditions based on anatomical considerations alone, because of the smaller organ masses for the Indian; for some pathological conditions the effective doses are 11-22% more. When tissue risk factors are considered in addition to anatomical considerations, the estimated effective doses are still found to be

  12. Organ-specific radiation-induced cancer risk estimates due to radiotherapy for benign pigmented villonodular synovitis

    Mazonakis, Michalis; Tzedakis, Antonis; Lyraraki, Efrossyni; Damilakis, John

    2016-09-01

    Pigmented villonodular synovitis (PVNS) is a benign disease affecting synovial membranes of young and middle-aged adults. The aggressive treatment of this disorder often involves external-beam irradiation. This study was motivated by the lack of data relating to the radiation exposure of healthy tissues and radiotherapy-induced cancer risk. Monte Carlo methodology was employed to simulate a patient’s irradiation for PVNS in the knee and hip joints with a 6 MV photon beam. The average radiation dose received by twenty-two out-of-field critical organs of the human body was calculated. These calculations were combined with the appropriate organ-, age- and gender-specific risk coefficients of the BEIR-VII model to estimate the lifetime probability of cancer development. The risk for carcinogenesis to colon, which was partly included in the treatment fields used for hip irradiation, was determined with a non-linear mechanistic model and differential dose-volume histograms obtained by CT-based 3D radiotherapy planning. Risk assessments were compared with the nominal lifetime intrinsic risk (LIR) values. Knee irradiation to 36 Gy resulted in out-of-field organ doses of 0.2-24.6 mGy. The corresponding range from hip radiotherapy was 1.2-455.1 mGy whereas the organ equivalent dose for the colon was up to 654.9 mGy. The organ-specific cancer risks from knee irradiation for PVNS were found to be inconsequential since they were at least 161.5 times lower than the LIRs irrespective of the patient’s age and gender. The bladder and colon cancer risk from radiotherapy in the hip joint was up to 3.2 and 6.6 times smaller than the LIR, respectively. These cancer risks may slightly elevate the nominal incidence rates and they should not be ignored during the patient’s treatment planning and follow-up. The probabilities for developing any other solid tumor were more than 20 times lower than the LIRs and, therefore, they may be considered as small.

  13. New aspects on the contribution of primary defects in silicon due to long-time degradation of detectors operating in high fields of radiation

    Lazanu, Sorina; Lazanu, Ionel

    2006-01-01

    Full text: Silicon detectors will represent an important option for the next generation of experiments in high energy physics, for astroparticle and nuclear experiments, where the requirements to operate long time in high radiation environments will represent a major problem. After the long-time operation in high radiation fields, the bulk displacement damage produces the following effects at the device level: increase of the leakage current, decrease of the satisfactory Signal/Noise ratio, increase of the effective carrier concentration, and thus of the depletion voltage, decrease of the charge collection efficiency up to unacceptable levels. In this contribution we investigate the new perspective in understanding the fundamental phenomena in silicon and implications for the degradation of the characteristics of detectors given by the consideration of the existence of the new primary defect: fourfold coordinated defect, Si FFCD , with a lower value of the formation energy by comparison with the 'classically' known vacancies and interstitials. Predicted by Goedecker and co-workers, its characteristics were indirectly determined by Lazanu and Lazanu. The correlation between the rate of generation of primary defects, material composition and observable effects is investigated considering different growth technologies and resistivities (up to tens of kΩcm) as time and fluence dependencies. This allows to estimate the expected behaviour of the materials and detectors in concrete environments at the next generations of high energy physics experiments as SLHC or VLHC for example. This new defect could represent the elementary block for new extended defects and in principle it could generate local amorphization of the semiconductor. Its existence and characteristics in other semiconductors is also investigated. (author)

  14. Measurements techniques for transportation noise

    Brambilla, G.

    2001-01-01

    The noise from transport systems (roads, railways and aircraft) are increasing more and more both in space and in time and, therefore, they are still the major factor responsible for environmental noise pollution. The population exposed to transport noise is also increasing, and the corresponding health effects on people (i.e. annoyance and sleep disturbance) become more severe. Due to this current situation international and national legislation has been issued and implemented to reduce the harmful effects of such noise. This paper describes the techniques prescribed by recent Italian legislation to measure road, railway and aircraft noise. (author)

  15. Strategy for the assessment of the radiation exposure at workplaces due to radon and radon decay products

    Czarwinski, R.; Lehmann, R.

    1996-01-01

    According to the future EU basic standards the exposures to radon decay products have to be taken into consideration. Therefore it is necessary to investigate: * which working operation could be connected with an increased exposure to radon decay products, * which workplaces have to be considered, * how many employees could be afflicted, * which methods should be applied for the investigation and - as for as necessary - for supervision. On the basis of the current radiation protection legislation in the new Federal Lands working operations which are connected with radon exposures have already been monitored. For instance, in 1994 3095 persons were supervised, 2422 of them were engaged in clean-up operations at wismut facilities (including underground work) and 673 at non-uranium mines and facilities (conventional mining), water treatment plants, show caves and spas. The extension of the monitoring to similar workplaces in the old Federal Lands is going to discussed in implementation of the EU standards. Beyond it further workplaces affected by radon and radon decay products exist. Therefore it is helpful to get an overview about the kinds of workplaces and the number of afflicted employees. (author)

  16. Occurrence of Antibiotic resistance in some bacterial strains due to gamma radiation, heavy metals or food preservatives

    Mattar, Z.A.; Bashandy, A.S.

    2006-01-01

    The susceptibility of bacterial strains (B. cereus, Staph. aureus, Escherichia coli and Salmonella) against 10 different antibiotics that are commonly used against food borne pathogens was studied. All the tested strains were observed to tolerate up to 100 mg/l copper sulphate or lead acetate, and there was a positive correlations between the tolerance to high levels of Cu or Pb and multiple antibiotic resistance was investigated. When the food preservatives (potassium sorbate or sodium benzoate) were added to the growth medium at different concentrations, the bacterial strains were able to tolerate up to 1000 ppm potassium sorbate or sodium benzoate (MIC). The antibiotic resistance of these strains was increased when grown on media supplemented with the MIC of sodium sorbate or potassium benzoate. When these bacterial strains were irradiated at dose levels of 1 or 3 or 5 KGy and examined for antibiotic sensitivity, a correlation was observed between the increases of radiation dose up to 5 KGy and the antibiotic resistance in all the studied strains

  17. Application of RESRAD Model to Assess Radiation Doses due to TENORM Accumulation in Evaporation Pond during Petroleum Production

    Othman, M.H.; Hassan, H.B.

    2013-01-01

    TE- Naturally Occurring Radioactive Materials (TE- NORM) is the potential radiation source in the petroleum industry which needs to be identified and controlled to maintain safe working conditions and protection of the environment. In this study radioactive contamination of produced water by NORM has been modeled by using RESRAD (version 6.5) computer code to evaluate potential radiological doses and health risks to workers at several oil field locations. The presence of NORM in produced water unlikely to cause external exposures which may be exceeded dose limits for workers. In this assessment the exposure source parameters were adjusted a period of 100 years and area of evaporation pond was 1300 m 2 and 10 m depth. The predicted maximum total effective doses equivalent received by workers from produced water in evaporation pond are (1.5×10 -5 mSv/yr) and for soil (categories I, II and III) are (0.732, 0.244 and 0.150 mSv/yr). Also its annual total cancer risk for produced water is (1.25×10 -9 ) and for soil (categories I, II and III) are (6.0×x10 -5 , 2.0 x10 -5 , 1.25 x10 -5 ) respectively.

  18. Analysis and estimation on composition and property change in atomic level due to radiation damage of materials

    Furuya, Kazuo; Son Menhi; Mitsuishi Kazuki; Yashihara, Kazuhiro; Sito, Tetsuya

    1999-01-01

    Porous silicon was analyzed by an analytical high-resolution ultra high voltage transmission electron microscope, which could in situ observation under electron beam radiation and the microanalysis. This study was carried out as the fundamental investigation of the relation between the local chemical bonding state and the optical transition. When p-type silicon wafer was obtained by the anodic oxidation, PL intensity increased with increasing the current of anodic oxidation and the lifetime increased a little with the current. The porous silicon layer constructed a tree structure. The more the current was large, the more fine the structure became. The fact showed the fine tree structure was of advantage to light emission. SiO 2 coexisted in the porous silicon and the amount of them was proportional to the emission intensity. These facts indicated that PL process was strongly related to the defects in the SiO 2 or the boundary between SiO 2 and Si crystal. (S.Y.)

  19. Potentiality of Melatonin as a Radiation Protector against Hemoglobin Damage in the Experimental Animals Due to Gamma Irradiation

    Farag, H.; Hassan, R. A.; Mohamed, Sh.

    2013-01-01

    Ionizing radiation causes serious damage in biological system. Some drugs and antioxidants are used to prevent such damage. In the present study two doses of melatonin (10 mg⁄kg and 30 mg⁄kg) were selected to be used for such purpose. The radioprotective effects of melatonin on hemoglobin of red blood cells from female mice was studied through UV absorption spectrum, ESR spectroscopy, dielectric measurements and relative viscosity .The results of Hemoglobin absorption indicate that a pronounced increase in the average value of peak position and width at half maximum W hmax followed by a decrease in the absorbance of sort band, decrease in absorption ratio A 578 / A 540 in addition to disappearance of globin band at 275 nm. The free radicals which are expected to be formed after exposing to γ-irradiation are detected by electron spin resonance spectroscopy (ESR). The results indicate that the intensity of ESR signal for hemoglobin extracted from animals exposed to γ- irradiation is greater as compared with normal hemoglobin. Dielectric measurements indicate that there is an increase in dielectric permittivity (ε‵), the dielectric loss (ε‶) and the a.c conductivity (σ ac ) while some decrease is noticed in the viscosity measurements after exposing to irradiation. The data obtained from the whole studied parameters after treating animals with melatonin become closer to those for unirradiated samples.

  20. Automation of the monitoring in real time of the absorbed dose rate in air due to the environmental gamma radiation in Cuba

    Dominguez L, O.; Capote F, E.; Carrazana G, J.A.; Manzano de Armas, J.F.; Alonso A, D.; Prendes A, M.; Zerquera, J.T.; Caveda R, C.A.; Kalberg, O.; Fabelo B, O.; Montalvan E, A.; Cartas A, H.; Leyva F, J.C.

    2006-01-01

    The Center of Protection and Hygiene of the Radiations (CPHR) like center rector of the National Net of Environmental Radiological Surveillance (RNVRA), it has strengthened their detection capacity and of answer before a situation of radiological emergency. The measurements of the absorbed dose rate in air due to the environmental gamma radiation in the main stations of the Net are obtained in real time and the CPHR receives the data coming from these posts at one time relatively short. To improve the operability of the RNVRA it was necessary to complete the facilities of existent monitoring using 4 automatic measurement stations with probes of gamma detection, implementing in this way a measurement system on real time. On the other hand the software were developed: GenironProbeFech, to obtain the data of the probes, DataMail for the shipment of the same ones by electronic mail and GammaRed that receives and processes the data in the rector center. (Author)

  1. A low cost network of spectrometer radiation detectors based on the ArduSiPM a compact transportable Software/Hardware Data Acquisition system with Arduino DUE

    Bocci, Valerio; Chiodi, Giacomo; Iacoangeli, Francesco; Nuccetelli, Massimo; Recchia, Luigi

    2015-01-01

    The necessity to use Photo Multipliers (PM) as light detector limited in the past the use of crystals in radiation handled device preferring the Geiger approach. The Silicon Photomultipliers (SiPMs) are very small and cheap, solid photon detectors with good dynamic range and single photon detection capability, they are usable to supersede cumbersome and difficult to use Photo Multipliers (PM). A SiPM can be coupled with a scintillator crystal to build efficient, small and solid radiation detector. A cost effective and easily replicable Hardware software module for SiPM detector readout is made using the ArduSiPM solution. The ArduSiPM is an easily battery operable handled device using an Arduino DUE (an open Software/Hardware board) as processor board and a piggy-back custom designed board (ArduSiPM Shield), the Shield contains all the blocks features to monitor, set and acquire the SiPM using internet network. (authors)

  2. A low cost network of spectrometer radiation detectors based on the ArduSiPM a compact transportable Software/Hardware Data Acquisition system with Arduino DUE

    Bocci, Valerio; Chiodi, Giacomo; Iacoangeli, Francesco; Nuccetelli, Massimo; Recchia, Luigi [INFN Sezione di Roma, P.le Aldo moro 2, Rome, I-00185 (Italy)

    2015-07-01

    The necessity to use Photo Multipliers (PM) as light detector limited in the past the use of crystals in radiation handled device preferring the Geiger approach. The Silicon Photomultipliers (SiPMs) are very small and cheap, solid photon detectors with good dynamic range and single photon detection capability, they are usable to supersede cumbersome and difficult to use Photo Multipliers (PM). A SiPM can be coupled with a scintillator crystal to build efficient, small and solid radiation detector. A cost effective and easily replicable Hardware software module for SiPM detector readout is made using the ArduSiPM solution. The ArduSiPM is an easily battery operable handled device using an Arduino DUE (an open Software/Hardware board) as processor board and a piggy-back custom designed board (ArduSiPM Shield), the Shield contains all the blocks features to monitor, set and acquire the SiPM using internet network. (authors)

  3. Estimation of annual effective dose from 226Ra 228Ra due to consumption of foodstuffs by inhabitants of high level natural radiation of Ramsar, Iran

    Fathivand, A.A.; Asefi, M.; Amidi, A.

    2005-01-01

    Full text: A knowledge of natural radioactivity in man and his environment is important since naturally occurring radionuclides are the major source of radiation exposure to man. Radioactive nuclides present in the natural environment enter the human body mainly through food and water.Besides, measurement of naturally occurring radionuclides in the environment can be used not only as a reference when routine releases from nuclear installation or accidental radiation exposures are assessed, but also as a baseline to evaluate the impact caused by non-nuclear activities. In Iran, measurement of natural and artificial radionuclides in environmental samples in normal and high-background radiation areas have been performed by some investigators but no information has been available on 226 Ra and 228 Ra in foodstuffs. Therefore we have started measurements of 226 Ra and 228 Ra in foodstuffs of Ramsar which is a coastal city in the north part of Iran and has been known as one of the world's high level natural radiation areas, using low level gamma spectrometry measurement system .The results from our measurements and food consumption rates for inhabitants of Ramsar city have been used for the estimation of annual effective dose due to consumption of foodstuffs by inhabitants of Ramsar city. A total of 33 samples from 11 different foodstuffs including root vegetables (beetroot), leafy vegetables (lettuce, parsley and spinach) and tea, meat,chicken, pea,broad bean, rice, and cheese were purchased from markets and were analyzed for their 226 Ra and 228 Ra concentrations. The highest concentrations of 226 Ra and 228 Ra were determined in tea samples with 1570 and 1140 mBq kg -1 respectively and the maximum estimated annual effective dose from 226 Ra and Ra due to consumption foodstuffs were determined to be 19.22 and 0.71 μSv from rice and meat samples respectively

  4. Comparison of measured and predicted airfoil self-noise with application to wind turbine noise reduction

    Dassen, T.; Parchen, R.; Guidati, G.; Wagner, S.; Kang, S.; Khodak, A.E.

    1998-01-01

    In the ongoing JOULE-III project 'Development of Design Tools for Reduced Aerodynamic Noise Wind Turbines (DRAW)', prediction codes for inflow-turbulence (IT) noise and turbulent boundary layer trailing-edge (TE) noise, are developed and validated. It is shown that the differences in IT noise radiation between airfoils having a different shape, are correctly predicted. The first, preliminary comparison made between predicted and measured TE noise spectra yields satisfactory results. 17 refs

  5. Assessment of external and internal doses due to farming in high background radiation areas in old tin mining localities in Jos-plateau, Nigeria

    Jibiri, N.N.; Farai, I.P.; Alausa, S.K.

    2009-01-01

    Farming on soils situated in high background radiation areas can result to enhanced radiation exposure scenarios and pathways to humans. To assess the likely levels of exposures, farm soil samples were collected from different farmlands in three old tin mining localities (Bitsichi, Bukuru and Ropp) in Jos Plateau Nigeria, known for high radiations. The soil samples were analyzed for the activity concentrations of 226 Ra, 232 Th and 40 K, using gamma-ray spectroscopy. The outdoor annual effective dose rates were calculated using the activity concentrations of the radionuclides and were found to vary from 0.07 mSv to 2.02 mSv across the three localities. Considering dust generation from soil tillage and inadvertent ingestion of soil particles, the likely internal radiation hazards were estimated using conservative dust and soil loading factors. The total average annual effective dose rates due to 226 Ra and 232 Th that could result from dust inhalation and ingestion of soil particles were 16.9 μSv, 8.1 μSv and 8.8 μSv, respectively for Bitsichi, Bukuru and Ropp. Though these values are about 5% the outdoor exposures to the farmers in those farms and greater than 1 μSv y-1, from the point of view of radiation protection and risk, they are significant. It suffices to say, therefore, that the results of this study will create the possibility of the importance to evaluate the health risk among the farming population and workplace environments which often is not covered by regulations concerning health protection. (author)

  6. Assessment of radiological risk parameters associated with some selected rivers around oil mineral producing sites in Abia State, Nigeria due to gross alpha and beta radiations

    Enyinna, Paschal Ikenna; Uzochukwu, Francis C.

    2016-01-01

    The study of gross alpha and beta radiation in environmental components and water bodies in particular is very crucial to the environmental, radiation and medical Physicist as this helps to promote good water quality and environmental hygiene. This research work understudied the radiological risk parameters due to gross alpha and beta radiations associated with three selected rivers around crude oil production sites in Abia State, Nigeria. Gross alpha and beta activities were computed for the three rivers based on analytical measurements carried out using a well-calibrated IN-20 model gas-flow proportional counter. Radiological risk parameters were computed from the activity concentrations which included; annual effective dose equivalent of radiation from ingested water (AEDE), annual gonadal dose equivalent (AGDE), and excess lifetime cancer risk (ELCR). The mean of the total AEDE due to the sum of alpha and beta radiations for the three rivers are 0.868 ± 0.221 mSv/y, 1.008 ± 0.156 mSv/y, and 0.917 ± 0.214 mSv/y; and are above the World Health Organization (WHO) permissible limit of 0.1 mSv/y. The mean of the total AGDE are 4.048 ± 1.063 mSv/y, 4.756 ± 0.739 mSv/y, and 4.295 ± 1.026 mSv/y; and are above the world average limit of 0.3 mSv/y. The mean of the total ELCR are (3.038 ± 0.774) X 10"-"3, (3.529 ± 0.547) X 10"-"3, and (3.210 ± 0.748) X 10"-"3; and are above the world average limit of 0.29 X 10"-"3. Most values of ELCR computed in this work are >6.0 X 10"-"4 estimated to be the risk of fatal and weighted nonfatal health conditions over a lifetime (70 years) derived from the radiation dose of 0.1 mSv/y (WHO permissible limit for drinking water). Drinking water from these surveyed sources could impact negatively on the end users. (author)

  7. Ion cyclotron emission due to the newly-born fusion products induced fast Alfven wave radiative instabilities in tokamaks

    Arunasalam, V.

    1995-08-01

    The velocity distribution functions of the newly born (t = 0) charged fusion products of tokamak discharges can be approximated by a monoenergetic ring distribution with a finite v parallel such that v perpendicular ∼ v parallel ∼ v j where (M j V j 2 /2) = E j , the directed birth energy of the charged fusion product species j of mass M j . As the time t progresses these distribution functions will evolve into a Gaussian in velocity with thermal spreadings given by the perpendicular and parallel temperatures T perpendicularj (t) = T parallelj (t) with T j (t) increasing as t increases and finally reaches an isotropic saturation value of T perpendicularj (t ∼ τ j ) = T parallelj (t ∼ τ j ) = T j (t ∼ τ j ) ∼ [M j T d E j /(M j + M)] 1/2 , where T d is the temperature of the background deuterium plasma ions, M is the mass of a triton or a neutron for j = protons and alpha particles, respectively, and τ j ∼ τ sj /4 is the thermalization time of the fusion product species j in the background deuterium plasma and τ sj is the slowing-down time. For times t of the order of τ j their distributions can be approximated by a Gaussian in their total energy. Then for times t ≥ τ sj the velocity distributions of these fusion products will relax towards their appropriate slowing-down distributions. Here the authors will examine the radiative stability of all these distributions. The ion cyclotron emission from energetic ion produced by fusion reactions or neutral beam injection promises to be a useful diagnostic tool

  8. Comparison between beta radiation dose distribution due to LDR and HDR ocular brachytherapy applicators using GATE Monte Carlo platform.

    Mostafa, Laoues; Rachid, Khelifi; Ahmed, Sidi Moussa

    2016-08-01

    Eye applicators with 90Sr/90Y and 106Ru/106Rh beta-ray sources are generally used in brachytherapy for the treatment of eye diseases as uveal melanoma. Whenever, radiation is used in treatment, dosimetry is essential. However, knowledge of the exact dose distribution is a critical decision-making to the outcome of the treatment. The Monte Carlo technique provides a powerful tool for calculation of the dose and dose distributions which helps to predict and determine the doses from different shapes of various types of eye applicators more accurately. The aim of this work consisted in using the Monte Carlo GATE platform to calculate the 3D dose distribution on a mathematical model of the human eye according to international recommendations. Mathematical models were developed for four ophthalmic applicators, two HDR 90Sr applicators SIA.20 and SIA.6, and two LDR 106Ru applicators, a concave CCB model and a flat CCB model. In present work, considering a heterogeneous eye phantom and the chosen tumor, obtained results with the use of GATE for mean doses distributions in a phantom and according to international recommendations show a discrepancy with respect to those specified by the manufacturers. The QC of dosimetric parameters shows that contrarily to the other applicators, the SIA.20 applicator is consistent with recommendations. The GATE platform show that the SIA.20 applicator present better results, namely the dose delivered to critical structures were lower compared to those obtained for the other applicators, and the SIA.6 applicator, simulated with MCNPX generates higher lens doses than those generated by GATE. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  9. Single-photoelectron noise reduction in scintillation detectors

    Marvin, T.P.

    1995-10-01

    The 1994--95 search at SLAC for mulicharged particles used four 21 x 21 x 130-cm 3 Bicron 408 scintillation counters to detect a signal at the single-photoelectron level. The competing noise requiring minimization was due to a combination of PM tube (8-inch Thorne EMI 9353KA) afterpulsing and ambient radiation-induced scintillator luminescence. A very slow decay (> 30 μs) component was observed and received particular attention. Efforts to reduce the SPE noise included photomultiplier tube base modifications, detector shielding and cooling, signal amplification, and veto procedures

  10. Inhibitory noise

    Alain Destexhe

    2010-03-01

    Full Text Available Cortical neurons in vivo may operate in high-conductance states, in which the major part of the neuron's input conductance is due to synaptic activity, sometimes several-fold larger than the resting conductance. We examine here the contribution of inhibition in such high-conductance states. At the level of the absolute conductance values, several studies have shown that cortical neurons in vivo are characterized by strong inhibitory conductances. However, conductances are balanced and spiking activity is mostly determined by fluctuations, but not much is known about excitatory and inhibitory contributions to these fluctuations. Models and dynamic-clamp experiments show that, during high-conductance states, spikes are mainly determined by fluctuations of inhibition, or by inhibitory noise. This stands in contrast to low-conductance states, in which excitatory conductances determine spiking activity. To determine these contributions from experimental data, maximum likelihood methods can be designed and applied to intracellular recordings in vivo. Such methods indicate that action potentials are indeed mostly correlated with inhibitory fluctuations in awake animals. These results argue for a determinant role for inhibitory fluctuations in evoking spikes, and do not support feed-forward modes of processing, for which opposite patterns are predicted.

  11. Noise estimation for remote sensing image data analysis

    Du, Qian

    2004-01-01

    Noise estimation does not receive much attention in remote sensing society. It may be because normally noise is not large enough to impair image analysis result. Noise estimation is also very challenging due to the randomness nature of the noise (for random noise) and the difficulty of separating the noise component from the signal in each specific location. We review and propose seven different types of methods to estimate noise variance and noise covariance matrix in a remotely sensed image. In the experiment, it is demonstrated that a good noise estimate can improve the performance of an algorithm via noise whitening if this algorithm assumes white noise.

  12. Thermal noise in mid-infrared broadband upconversion detectors

    Barh, Ajanta; Tidemand-Lichtenberg, Peter; Pedersen, Christian

    2018-01-01

    Low noise detection with state-of-the-art mid-infrared (MIR) detectors (e.g., PbS, PbSe, InSb, HgCdTe) is a primary challenge owing to the intrinsic thermal background radiation of the low bandgap detector material itself. However, researchers have employed frequency upconversion based detectors...... of the noise-equivalent power of an UCD system. In this article, we rigorously analyze the optical power generated by frequency upconversion of the intrinsic black-body radiation in the nonlinear material itself due to the crystals residual emissivity, i.e. absorption. The thermal radiation is particularly...... prominent at the optical absorption edge of the nonlinear material even at room temperature. We consider a conventional periodically poled lithium niobate (PPLN) based MIR-UCD for the investigation. The UCD is designed to cover a broad spectral range, overlapping with the entire absorption edge of the PPLN...

  13. Water concentration/activity and loss of vitamins B1 and E in pork due to gamma radiation

    Fox, J.B. Jr.; Lakritz, L.; Kohout, K.M.; Thayer, D.W.

    1994-01-01

    When irradiated, increasing the water content of pork by partial rehydration of freeze-dried L. dorsi muscle resulted in increasing rate of thiamin loss from zero in dry tissue to ca 6%/kGy of irradiation in tissue with 70% water. Conversely, the rate of loss of alpha-tocopherol decreased from 44%/kGy at 0% to 32%/kGy at 70% water. Decreasing water activity in buffers or in ground or freeze-dried pork by salt or sucrose had no effect on rate of loss of either vitamin following irradiation. Salt decreased the loss of both vitamins in pork due to competition for the hydroxyl radical by chloride ions

  14. Studies on radiation dose due to radioactive elements present in ground water and soil samples around Mysore city, India.

    Chandrashekara, M S; Veda, S M; Paramesh, L

    2012-04-01

    A systematic study of the ground water and soil samples collected from different locations around Mysore city (12(°)N and 76(°)E) has been carried out. (226)Ra activity concentration in water samples varies from 0.28 to 189 mBq l(-1) with a geometric mean (GM) of 4.75 mBq l(-1) and (222)Rn concentration in ground water varies from 4.25 to 435 Bq l(-1) with a GM of 25.9 Bq l(-1). The GM of inhalation and ingestion doses due to (222)Rn in water is 65.2 and 5.43, µSv y(-1), respectively. The measured GM gamma dose rate in air is 85.4 nGy h(-1) and absorbed dose rate estimated from the measured activity of radionuclides is 92.6 nGy h(-1).

  15. The Semipalatinsk nuclear test site: a first analysis of solid cancer incidence (selected sites) due to test-related radiation.

    Gusev, B I; Rosenson, R I; Abylkassimova, Z N

    1998-10-01

    Since 1956, cancer incidences have been analysed in several rayons of the Semipalatinsk oblast, with cross-sectional analyses being conducted every 5 years. Data on different tumor localizations were recorded within a heavily contaminated so-called main area of nine villages (estimated average effective equivalent dose about 2000 mSv) and a so-called control area (estimated average effective equivalent dose about 70 mSv), each including approximately 10000 persons. Up to 1970, the excess cancer incidence in the exposed villages was observed to have increased; after 1970, a decrease was noted, followed by a second increase in the late 1980s. The main sites of excess cancer included the esophagus, stomach, and liver. Up to 1970, the esophagus cancer incidence was predominant, but it decreased thereafter, while the incidence of stomach and liver cancers increased. The second peak of excess cancer rates was mainly due to lung, breast, and thyroid carcinomas.

  16. Radionuclides in food and the radiation exposure due to ingestion; Radionuklide in Lebensmitteln und die Strahlenexposition durch Ingestion

    Michel, Rolf

    2015-06-01

    As a consequence of the reactor accidents in Fukushima Daiichi high amounts of radioactive iodine and cesium isotopes were released into the terrestrial and marine Japanese environment. The largest release occurred on March 15, 2011 as a consequence of the containment failure of unit 2. Due to the meteorological conditions large area fallout occurred in the district of Fukushima. Other prefectures in the north of Japan were also contaminated. As a consequence of the high surface contamination the dose limits for drinking water, milk and milky products and food were increased to 200 Bq/kg.It turned out that the contamination of rice was marginal, the contamination of predatory fish higher than that of non-predatory fish. A systematic investigation of food samples could allow a better estimation of ingestion induced exposure.

  17. Practical Ranges of Loudness Levels of Various Types of Environmental Noise, Including Traffic Noise, Aircraft Noise, and Industrial Noise

    Sabine A. Janssen

    2011-05-01

    Full Text Available In environmental noise control one commonly employs the A-weighted sound level as an approximate measure of the effect of noise on people. A measure that is more closely related to direct human perception of noise is the loudness level. At constant A-weighted sound level, the loudness level of a noise signal varies considerably with the shape of the frequency spectrum of the noise signal. In particular the bandwidth of the spectrum has a large effect on the loudness level, due to the effect of critical bands in the human hearing system. The low-frequency content of the spectrum also has an effect on the loudness level. In this note the relation between loudness level and A-weighted sound level is analyzed for various environmental noise spectra, including spectra of traffic noise, aircraft noise, and industrial noise. From loudness levels calculated for these environmental noise spectra, diagrams are constructed that show the relation between loudness level, A‑weighted sound level, and shape of the spectrum. The diagrams show that the upper limits of the loudness level for broadband environmental noise spectra are about 20 to 40 phon higher than the lower limits for narrowband spectra, which correspond to the loudness levels of pure tones. The diagrams are useful for assessing limitations and potential improvements of environmental noise control methods and policy based on A-weighted sound levels.

  18. Collaboration of local government and experts responding to increase in environmental radiation level due to the nuclear disaster: focusing on their activities and latest radiological discussion

    Iimoto, T.; Nunokawa, J.; Fujii, H.; Takashima, R.; Hashimoto, M.; Fukuhara, T.; Yajima, T.; Matsuzawa, H.; Kurosawa, K.; Yanagawa, Y.; Someya, S.

    2015-01-01

    Activities were introduced in Kashiwa city in the Tokyo metropolitan area to correspond to the elevated environmental radiation level after the disaster of the Fukushima Daiichi nuclear power plant. These were based on a strong cooperation between local governments and experts. Ambient dose rate and radioactivity of foodstuff produced inside of the city have been monitored. Representative ambient dose rates around living environments have almost already become their original levels of the pre-accident because of the decontamination activity, natural washout and effective half-lives of radioactivity. The internal annual dose due to radioactive cesium under the policy of 'Local Production for Local Consumption' is estimated as extremely low comparing the variation range due to natural radioactivity. Systematic survey around a retention basin has been started. All of these latest monitoring data would be one of the core information for the policy making as well as a cost-benefit discussion and risk communication. (authors)

  19. Road traffic noise: self-reported noise annoyance versus GIS modelled road traffic noise exposure.

    Birk, Matthias; Ivina, Olga; von Klot, Stephanie; Babisch, Wolfgang; Heinrich, Joachim

    2011-11-01

    self-reported road traffic noise annoyance is commonly used in epidemiological studies for assessment of potential health effects. Alternatively, some studies have used geographic information system (GIS) modelled exposure to road traffic noise as an objective parameter. The aim of this study was to analyse the association between noise exposure due to neighbouring road traffic and the noise annoyance of adults, taking other determinants into consideration. parents of 951 Munich children from the two German birth cohorts GINIplus and LISAplus reported their annoyance due to road traffic noise at home. GIS modelled road traffic noise exposure (L(den), maximum within a 50 m buffer) from the noise map of the city of Munich was available for all families. GIS-based calculated distance to the closest major road (≥10,000 vehicles per day) and questionnaire based-information about family income, parental education and the type of the street of residence were explored for their potential influence. An ordered logit regression model was applied. The noise levels (L(den)) and the reported noise annoyance were compared with an established exposure-response function. the correlation between noise annoyance and noise exposure (L(den)) was fair (Spearman correlation r(s) = 0.37). The distance to a major road and the type of street were strong predictors for the noise annoyance. The annoyance modelled by the established exposure-response function and that estimated by the ordered logit model were moderately associated (Pearson's correlation r(p) = 0.50). road traffic noise annoyance was associated with GIS modelled neighbouring road traffic noise exposure (L(den)). The distance to a major road and the type of street were additional explanatory factors of the noise annoyance appraisal.

  20. Aerodynamic noise prediction of a Horizontal Axis Wind Turbine using Improved Delayed Detached Eddy Simulation and acoustic analogy

    Ghasemian, Masoud; Nejat, Amir

    2015-01-01

    Highlights: • The noise predictions are performed by Ffowcs Williams and Hawkings method. • There is a direct relation between the radiated noise and the wind speed. • The tonal peaks in the sound spectra match with the blade passing frequency. • The quadrupole noises have negligible effect on the low frequency noises. - Abstract: This paper presents the results of the aerodynamic and aero-acoustic prediction of the flow field around the National Renewable Energy Laboratory Phase VI wind turbine. The Improved Delayed Detached Eddy Simulation turbulence model is applied to obtain the instantaneous turbulent flow field. The noise prediction is carried out using the Ffowcs Williams and Hawkings acoustic analogy. Simulations are performed for three different inflow conditions, U = 7, 10, 15 m/s. The capability of the Improved Delayed Detached Eddy Simulation turbulence model in massive separation is verified with available experimental data for pressure coefficient. The broadband noises of the turbulent boundary layers and the tonal noises due to the blade passing frequency are predicted via flow field noise simulation. The contribution of the thickness, loading and quadrupole noises are investigated, separately. The results indicated that there is a direct relation between the strength of the radiated noise and the wind speed. Furthermore, the effect of the receiver location on the Overall Sound Pressure Level is investigated

  1. Non-relativistic Free–Free Emission due to the n -distribution of Electrons—Radiative Cooling and Thermally Averaged and Total Gaunt Factors

    De Avillez, Miguel A. [Department of Mathematics, University of Évora, R. Romão Ramalho 59, 7000 Évora (Portugal); Breitschwerdt, Dieter, E-mail: mavillez@galaxy.lca.uevora.pt [Zentrum für Astronomie und Astrophysik, Technische Universität Berlin, Hardenbergstrasse 36, D-10623 Berlin (Germany)

    2017-09-01

    Tracking the thermal evolution of plasmas, characterized by an n -distribution, using numerical simulations, requires the determination of the emission spectra and of the radiative losses due to free–free emission from the corresponding temperature-averaged and total Gaunt factors. Detailed calculations of the latter are presented and associated with n -distributed electrons with the parameter n ranging from 1 (corresponding to the Maxwell–Boltzmann distribution) to 100. The temperature-averaged and total Gaunt factors with decreasing n tend toward those obtained with the Maxwell–Boltzmann distribution. Radiative losses due to free–free emission in a plasma evolving under collisional ionization equilibrium conditions and composed by H, He, C, N, O, Ne, Mg, Si, S, and Fe ions, are presented. These losses decrease with a decrease in the parameter n , reaching a minimum when n  = 1, and thus converge with the loss of thermal plasma. Tables of the thermal-averaged and total Gaunt factors calculated for n -distributions, and a wide range of electron and photon energies, are presented.

  2. Non-relativistic Free–Free Emission due to the n -distribution of Electrons—Radiative Cooling and Thermally Averaged and Total Gaunt Factors

    De Avillez, Miguel A.; Breitschwerdt, Dieter

    2017-01-01

    Tracking the thermal evolution of plasmas, characterized by an n -distribution, using numerical simulations, requires the determination of the emission spectra and of the radiative losses due to free–free emission from the corresponding temperature-averaged and total Gaunt factors. Detailed calculations of the latter are presented and associated with n -distributed electrons with the parameter n ranging from 1 (corresponding to the Maxwell–Boltzmann distribution) to 100. The temperature-averaged and total Gaunt factors with decreasing n tend toward those obtained with the Maxwell–Boltzmann distribution. Radiative losses due to free–free emission in a plasma evolving under collisional ionization equilibrium conditions and composed by H, He, C, N, O, Ne, Mg, Si, S, and Fe ions, are presented. These losses decrease with a decrease in the parameter n , reaching a minimum when n  = 1, and thus converge with the loss of thermal plasma. Tables of the thermal-averaged and total Gaunt factors calculated for n -distributions, and a wide range of electron and photon energies, are presented.

  3. Simulation of equivalent dose due to accidental electron beam loss in Indus-1 and Indus-2 synchrotron radiation sources using FLUKA code

    Sahani, P.K.; Dev, Vipin; Singh, Gurnam; Haridas, G.; Thakkar, K.K.; Sarkar, P.K.; Sharma, D.N.

    2008-01-01

    Indus-1 and Indus-2 are two Synchrotron radiation sources at Raja Ramanna Centre for Advanced Technology (RRCAT), India. Stored electron energy in Indus-1 and Indus-2 are 450MeV and 2.5GeV respectively. During operation of storage ring, accidental electron beam loss may occur in addition to normal beam losses. The Bremsstrahlung radiation produced due to the beam losses creates a major radiation hazard in these high energy electron accelerators. FLUKA, the Monte Carlo radiation transport code is used to simulate the accidental beam loss. The simulation was carried out to estimate the equivalent dose likely to be received by a trapped person closer to the storage ring. Depth dose profile in water phantom for 450MeV and 2.5GeV electron beam is generated, from which percentage energy absorbed in 30cm water phantom (analogous to human body) is calculated. The simulation showed the percentage energy deposition in the phantom is about 19% for 450MeV electron and 4.3% for 2.5GeV electron. The dose build up factor in 30cm water phantom for 450MeV and 2.5GeV electron beam are found to be 1.85 and 2.94 respectively. Based on the depth dose profile, dose equivalent index of 0.026Sv and 1.08Sv are likely to be received by the trapped person near the storage ring in Indus-1 and Indus-2 respectively. (author)

  4. Spin noise spectroscopy of ZnO

    Horn, H.; Berski, F.; Balocchi, A.; Marie, X.; Mansur-Al-Suleiman, M.; Bakin, A.; Waag, A.; Hübner, J.; Oestreich, M.

    2013-12-01

    We investigate the thermal equilibrium dynamics of electron spins bound to donors in nanoporous ZnO by optical spin noise spectroscopy. The spin noise spectra reveal two noise contributions: A weak spin noise signal from undisturbed localized donor electrons with a dephasing time of 24 ns due to hyperfine interaction and a strong spin noise signal with a spin dephasing time of 5 ns which we attribute to localized donor electrons which interact with lattice defects.

  5. Spin noise spectroscopy of ZnO

    Horn, H.; Berski, F.; Hübner, J.; Oestreich, M. [Institute for Solid State Physics, Leibniz Universität Hannover, Appelstr. 2, 30167 Hannover (Germany); Balocchi, A.; Marie, X. [INSA-CNRS-UPS, LPCNO, Université de Toulouse, 135 Av. de Rangueil, 31077 Toulouse (France); Mansur-Al-Suleiman, M.; Bakin, A.; Waag, A. [Institute of Semiconductor Technology, Technische Universität Braunschweig, Hans-Sommer-Straße 66, 38106 Braunschweig (Germany)

    2013-12-04

    We investigate the thermal equilibrium dynamics of electron spins bound to donors in nanoporous ZnO by optical spin noise spectroscopy. The spin noise spectra reveal two noise contributions: A weak spin noise signal from undisturbed localized donor electrons with a dephasing time of 24 ns due to hyperfine interaction and a strong spin noise signal with a spin dephasing time of 5 ns which we attribute to localized donor electrons which interact with lattice defects.

  6. Inhalation exposures due to radon and thoron ((222)Rn and (220)Rn): Do they differ in high and normal background radiation areas in India?

    Mishra, Rosaline; Sapra, B K; Prajith, R; Rout, R P; Jalaluddin, S; Mayya, Y S

    2015-09-01

    In India, High Background Radiation Areas (HBRAs) due to enhanced levels of naturally occurring radionuclides in soil (thorium and, to a lesser extent, uranium), are located along some parts of the coastal tracts viz. the coastal belt of Kerala, Tamilnadu and Odisha. It is conjectured that these deposits will result in higher emissions of radon isotopes ((222)Rn and (220)Rn) and their daughter products as compared to Normal Background Radiation Areas (NBRAs). While the annual external dose rates contributed by gamma radiations in these areas are about 5-10 times higher, the extent of increase in the inhalation dose rates attributable to (222)Rn and (220)Rn and their decay products is not well quantified. Towards this, systematic indoor surveys were conducted wherein simultaneous measurements of time integrated (222)Rn and (220)Rn gas and their decay product concentrations was carried out in around 800 houses in the HBRAs of Kerala and Odisha to estimate the inhalation doses. All gas measurements were carried out using pin-hole cup dosimeters while the progeny measurements were with samplers and systems based on the Direct radon/thoron Progeny sensors (DRPS/DTPS). To corroborate these passive measurements of decay products concentrations, active sampling was also carried out in a few houses. The results of the surveys provide a strong evidence to conclude that the inhalation doses due to (222)Rn and (220)Rn gas and their decay products in these HBRAs are in the same range as observed in the NBRAs in India. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Noise analysis of a digital radiography system

    Arnold, B.A.; Scheibe, P.O.

    1984-01-01

    The sources of noise in a digital video subtraction angiography system were identified and analyzed. Signal-to-noise ratios of digital radiography systems were measured using the digital image data recorded in the computer. The major sources of noise include quantum noise, TV camera electronic noise, quantization noise from the analog-to-digital converter, time jitter, structure noise in the image intensifier, and video recorder electronic noise. A new noise source was identified, which results from the interplay of fixed pattern noise and the lack of image registration. This type of noise may result from image-intensifier structure noise in combination with TV camera time jitter or recorder time jitter. A similar noise source is generated from the interplay of patient absorption inhomogeneities and patient motion or image re-registration. Signal-to-noise ratios were measured for a variety of experimental conditions using subtracted digital images. Image-intensifier structure noise was shown to be a dominant noise source in unsubtracted images at medium to high radiation exposure levels. A total-system signal-to-noise ratio (SNR) of 750:1 was measured for an input exposure of 1 mR/frame at the image intensifier input. The effect of scattered radiation on subtracted image SNR was found to be greater than previously reported. The detail SNR was found to vary approximately as one plus the scatter degradation factor. Quantization error noise with 8-bit image processors (signal-to-noise ratio of 890:1) was shown to be of increased importance after recent improvements in TV cameras. The results of the analysis are useful both in the design of future digital radiography systems and the selection of optimum clinical techniques

  8. Radiation dose reduction using 100-kVp and a sinogram-affirmed iterative reconstruction algorithm in adolescent head CT: Impact on grey-white matter contrast and image noise

    Nagayama, Yasunori [Kumamoto City Hospital, Department of Radiology, Kumamoto (Japan); Kumamoto University, Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto (Japan); Nakaura, Takeshi; Yuki, Hideaki; Hirarta, Kenichiro; Kidoh, Masafumi; Oda, Seitaro; Utsunomiya, Daisuke; Yamashita, Yasuyuki [Kumamoto University, Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto (Japan); Tsuji, Akinori; Urata, Joji; Furusawa, Mitsuhiro [Kumamoto City Hospital, Department of Radiology, Kumamoto (Japan)

    2017-07-15

    To retrospectively evaluate the image quality and radiation dose of 100-kVp scans with sinogram-affirmed iterative reconstruction (IR) for unenhanced head CT in adolescents. Sixty-nine patients aged 12-17 years underwent head CT under 120- (n = 34) or 100-kVp (n = 35) protocols. The 120-kVp images were reconstructed with filtered back-projection (FBP), 100-kVp images with FBP (100-kVp-F) and sinogram-affirmed IR (100-kVp-S). We compared the effective dose (ED), grey-white matter (GM-WM) contrast, image noise, and contrast-to-noise ratio (CNR) between protocols in supratentorial (ST) and posterior fossa (PS). We also assessed GM-WM contrast, image noise, sharpness, artifacts, and overall image quality on a four-point scale. ED was 46% lower with 100- than 120-kVp (p < 0.001). GM-WM contrast was higher, and image noise was lower, on 100-kVp-S than 120-kVp at ST (p < 0.001). CNR of 100-kVp-S was higher than of 120-kVp (p < 0.001). GM-WM contrast of 100-kVp-S was subjectively rated as better than of 120-kVp (p < 0.001). There were no significant differences in the other criteria between 100-kVp-S and 120-kVp (p = 0.072-0.966). The 100-kVp with sinogram-affirmed IR facilitated dramatic radiation reduction and better GM-WM contrast without increasing image noise in adolescent head CT. (orig.)

  9. Gamma noise in CCDs

    Autio, G.W.; Bafico, M.A.

    1975-01-01

    The overall results indicated that charge coupled devices (CCD) used to read out detector signals or as signal processing electronics in future space sensors can operate real time in a high ionising radiation environment. Future work should be directed towards hardening the CCDs during the fabrication processes in order that they may survive total radiation doses up to 1 x 10 6 Rad (Si) and toward investigating ionising radiation effects in CCDs that are coupled with i.r. detectors. CCD devices employed to read out detector signals can be made capable of handling radiation induced excess noise and high false alarm rates generated in the detector elements. Ionising radiation effects induced in the detectors are expected to dominate those generated directly in the CCD readout structure; how much depends on the relative size of the detector. The low frequency γ induced excess noise measured in the CCD/MOSFET structure could cause problems for space sensors required to operate in real time only at the very high γ flux levels. Discrimination and circumvention techniques at the CCD ERO output are possible. γ pulses measured at the CCD ERO output were distributed in amplitude and exhibited variable pulse widths (some were many times a clock period). (author)

  10. Effect of contrast material on image noise and radiation dose in adult chest computed tomography using automatic exposure control: A comparative study between 16-, 64- and 128-slice CT

    Paul, Jijo, E-mail: jijopaul1980@gmail.com [Clinic of the Goethe University, Department of Diagnostic and Interventional Radiology, Haus 23C UG, Theodor-Stern-Kai 7, 60590 Frankfurt am Main (Germany); Goethe University, Department of Biophysics, Max von Laue-Strasse 1, 60438 Frankfurt am Main (Germany); Schell, Boris, E-mail: boris.schell@googlemail.com [Clinic of the Goethe University, Department of Diagnostic and Interventional Radiology, Haus 23C UG, Theodor-Stern-Kai 7, 60590 Frankfurt am Main (Germany); Kerl, J. Matthias, E-mail: matthias.kerl@gmai.com [Clinic of the Goethe University, Department of Diagnostic and Interventional Radiology, Haus 23C UG, Theodor-Stern-Kai 7, 60590 Frankfurt am Main (Germany); Maentele, Werner, E-mail: maentele@biophysik.uni-frankfurt.de [Goethe University, Department of Biophysics, Max von Laue-Strasse 1, 60438 Frankfurt am Main (Germany); Vogl, Thomas J., E-mail: t.vogl@em.uni-frankfurt.de [Clinic of the Goethe University, Department of Diagnostic and Interventional Radiology, Haus 23C UG, Theodor-Stern-Kai 7, 60590 Frankfurt am Main (Germany); Bauer, Ralf W., E-mail: ralfwbauer@aol.com [Clinic of the Goethe University, Department of Diagnostic and Interventional Radiology, Haus 23C UG, Theodor-Stern-Kai 7, 60590 Frankfurt am Main (Germany)

    2011-08-15

    Purpose: To determine the difference in radiation dose between non-enhanced (NECT) and contrast-enhanced (CECT) chest CT examinations contributed by contrast material with different scanner generations with automatic exposure control (AEC). Methods and materials: Each 42 adult patients received a NECT and CECT of the chest in one session on a 16-, 64- or 128-slice CT scanner with the same scan protocol settings. However, AEC technology (Care Dose 4D, Siemens) underwent upgrades in each of the three scanner generations. DLP, CTDIvol and image noise were compared. Results: Although absolute differences in image noise were very small and ranged between 10 and 13 HU for NECT and CECT in median, the differences in image noise and dose (DLP: 16-slice:+2.8%; 64-slice:+3.9%; 128-slice:+5.6%) between NECT and CECT were statistically significant in all groups. Image noise and dose parameters were significantly lower in the most recent 128-slice CT generation for both NECT and CECT (DLP: 16-slice:+35.5-39.2%; 64-slice:+6.8-8.5%). Conclusion: The presence of contrast material lead to an increase in dose for chest examinations in three CT generations with AEC. Although image noise values were significantly higher for CECT, the absolute differences were in a range of 3 HU. This can be regarded as negligible, thus indicating that AEC is able to fulfill its purpose of maintaining image quality. However, technological developments lead to a significant reduction of dose and image noise with the latest CT generation.

  11. Radiation dose reduction using 100-kVp and a sinogram-affirmed iterative reconstruction algorithm in adolescent head CT: Impact on grey-white matter contrast and image noise.

    Nagayama, Yasunori; Nakaura, Takeshi; Tsuji, Akinori; Urata, Joji; Furusawa, Mitsuhiro; Yuki, Hideaki; Hirarta, Kenichiro; Kidoh, Masafumi; Oda, Seitaro; Utsunomiya, Daisuke; Yamashita, Yasuyuki

    2017-07-01

    To retrospectively evaluate the image quality and radiation dose of 100-kVp scans with sinogram-affirmed iterative reconstruction (IR) for unenhanced head CT in adolescents. Sixty-nine patients aged 12-17 years underwent head CT under 120- (n = 34) or 100-kVp (n = 35) protocols. The 120-kVp images were reconstructed with filtered back-projection (FBP), 100-kVp images with FBP (100-kVp-F) and sinogram-affirmed IR (100-kVp-S). We compared the effective dose (ED), grey-white matter (GM-WM) contrast, image noise, and contrast-to-noise ratio (CNR) between protocols in supratentorial (ST) and posterior fossa (PS). We also assessed GM-WM contrast, image noise, sharpness, artifacts, and overall image quality on a four-point scale. ED was 46% lower with 100- than 120-kVp (p < 0.001). GM-WM contrast was higher, and image noise was lower, on 100-kVp-S than 120-kVp at ST (p < 0.001). CNR of 100-kVp-S was higher than of 120-kVp (p < 0.001). GM-WM contrast of 100-kVp-S was subjectively rated as better than of 120-kVp (p < 0.001). There were no significant differences in the other criteria between 100-kVp-S and 120-kVp (p = 0.072-0.966). The 100-kVp with sinogram-affirmed IR facilitated dramatic radiation reduction and better GM-WM contrast without increasing image noise in adolescent head CT. • 100-kVp head CT provides 46% radiation dose reduction compared with 120-kVp. • 100-kVp scanning improves subjective and objective GM-WM contrast. • Sinogram-affirmed IR decreases head CT image noise, especially in supratentorial region. • 100-kVp protocol with sinogram-affirmed IR is suited for adolescent head CT.

  12. Jet Noise Reduction by Microjets - A Parametric Study

    Zaman, K. B. M. Q.

    2010-01-01

    The effect of injecting tiny secondary jets (microjets ) on the radiated noise from a subsonic primary jet is studied experimentally. The microjets are injected on to the primary jet near the nozzle exit with variable port geometry, working fluid and driving pressure. A clear noise reduction is observed that improves with increasing jet pressure. It is found that smaller diameter ports with higher driving pressure, but involving less thrust and mass fraction, can produce better noise reduction. A collection of data from the present as well as past experiments is examined in an attempt to correlate the noise reduction with the operating parameters. The results indicate that turbulent mixing noise reduction, as monitored by OASPL at a shallow angle, correlates with the ratio of jet to primary jet driving pressures normalized by the ratio of corresponding diameters (p d /pjD). With gaseous injection, the spectral amplitudes decrease at lower frequencies while an increase is noted at higher frequencies. It is apparent that this amplitude crossover is at least partly due to shock-associated noise from the underexpanded jets themselves. Such crossover is not seen with water injection since the flow in that case is incompressible and there is no shock-associated noise. Centerline velocity data show that larger noise reduction is accompanied by faster jet decay as well as significant reduction in turbulence intensities. While a physical understanding of the dependence of noise reduction on p d /pjD remains unclear, given this correlation, an analysis explains the observed dependence of the effect on various other parameters.

  13. Dose modulated retrospective ECG-gated versus non-gated 64-row CT angiography of the aorta at the same radiation dose: Comparison of motion artifacts, diagnostic confidence and signal-to-noise-ratios

    Schernthaner, Ruediger E.; Stadler, Alfred; Beitzke, Dietrich; Homolka, Peter; Weber, Michael; Lammer, Johannes; Czerny, Martin; Loewe, Christian

    2012-01-01

    Purpose: To compare ECG-gated and non-gated CT angiography of the aorta at the same radiation dose, with regard to motion artifacts (MA), diagnostic confidence (DC) and signal-to-noise-ratios (SNRs). Materials and methods: Sixty consecutive patients prospectively randomized into two groups underwent 64-row CT angiography, with or without dose-modulated ECG-gating, of the entire aorta, due to several pathologies of the ascending aorta. MA and DC were both assessed using a four-point scale. SNRs were calculated by dividing the mean enhancement by the standard deviation. The dose-length-product (DLP) of each examination was recorded and the effective dose was estimated. Results: Dose-modulated ECG-gating showed statistically significant advantages over non-gated CT angiography, with regard to MA (p < 0.001) and DC (p < 0.001), at the aortic valve, at the origin of the coronary arteries, and at the dissection membrane, with a significant correlation (p < 0.001) between MA and DC. At the aortic wall, however, ECG-gated CT angiography showed statistically significant fewer MA (p < 0.001), but not a statistically significant higher DC (p = 0.137) compared to non-gated CT angiography. At the supra-aortic vessels and the descending aorta, the ECG-triggering showed no statistically significant differences with regard to MA (p = 0.861 and 0.526, respectively) and DC (p = 1.88 and 0.728, respectively). The effective dose of ECG-gated CT angiography (23.24 mSv; range, 18.43–25.94 mSv) did not differ significantly (p = 0.051) from that of non-gated CT angiography (24.28 mSv; range, 19.37–29.27 mSv). Conclusion: ECG-gated CT angiography of the entire aorta reduces MA and results in a higher DC with the same SNR, compared to non-gated CT angiography at the same radiation dose.

  14. Research on noise and vibration reduction at DB to improve the environmental friendliness of railway traffic

    Schulte-Werning, B.; Beier, M.; Degen, K. G.; Stiebel, D.

    2006-06-01

    One of the most prominent keywords relating to the environmental friendliness of railway traffic is noise reduction. Thus, the research and development programme "Low Noise Railway" of Deutsche Bahn (DB) is under way to treat the noise of the vehicles and infrastructure. The noise reduction of the trains and the rail/wheel system are being tackled within several projects. The direct noise experienced by railway-lineside residents due to train movements on the track can be reduced by minimising the sound radiation directly at the source. This is the first-choice solution, as it proves to be the most effective countermeasure regarding a cost-benefit relation. The limit values for the noise emission as specified in the technical specification for interoperability are an essential criterion to be confirmed during the procurement process of railway vehicles. A recently developed acoustical quality management scheme establishes systematic noise management to complete the vehicle procurement process in the phases of concept, design, construction and manufacturing. In freight traffic quiet railway wheels for block brake operation will play an important role in the future to meet the goal of a low-noise railway system. A first attempt to realise successfully the low-noise potential of such optimised wheels was performed, even if with mixed results. To show ways of reducing the noise of the cooling ventilation in locomotives, DB is a partner in a development project led by Siemens. A notable 8 dB(A) noise reduction was measured. Concerning bridge noise, a project was started based on an effective and cost-efficient combination of experiments and simulations in order to develop specifications for the construction of generic low-noise bridges.

  15. Drone noise

    Tinney, Charles; Sirohi, Jayant; University of Texas at Austin Team

    2017-11-01

    A basic understanding of the noise produced by single and multirotor drones operating at static thrust conditions is presented. This work acts as an extension to previous efforts conducted at The University of Texas at Austin (Tinney et al. 2017, AHS Forum 73). Propeller diameters ranging from 8 inch to 12 inch are examined for configurations comprising an isolated rotor, a quadcopter configuration and a hexacopter configuration, and with a constant drone pitch of 2.25. An azimuthal array of half-inch microphones, placed between 2 and 3 hub-center diameters from the drone center, are used to assess the acoustic near-field. Thrust levels, acquired using a six degree-of-freedom load cell, are then used to correlate acoustic noise levels to aerodynamic performance for each drone configuration. The findings reveal a nearly logarithmic increase in noise with increasing thrust. However, for the same thrust condition, considerable noise reduction is achieved by increasing the number of propeller blades thereby reducing the blade passage frequency and both the thickness and loading noise sources that accompany it.

  16. Variation Process of Radiation Belt Electron Fluxes due to Interaction With Chorus and EMIC Rising-tone Emissions Localized in Longitude

    Kubota, Y.; Omura, Y.

    2017-12-01

    Using results of test particle simulations of a large number of electrons interacting with a pair of chorus emissions, we create Green's functions to model the electron distribution function after all of the possible interactions with the waves [Omura et al., 2015]. Assuming that the waves are generated in a localized range of longitudes in the dawn side, we repeat taking the convolution integral of the Green's function with the distribution function of the electrons injected into the generation region of the localized waves. From numerical and theoretical analyses, we find that electron acceleration process only takes place efficiently below 4 MeV. Because extremely relativistic electrons go through the wave generation region rapidly due to grad-B0 and curvature drift, they don't have enough interaction time to be accelerated. In setting up the electrons after all interaction with chorus emissions as initial electron distribution function, we also compute the loss process of radiation belt electron fluxes due to interaction with EMIC rising-tone emissions generated in a localized range of longitudes in the dusk side [Kubota and Omura,2017]. References: (1) Omura, Y., Y. Miyashita, M. Yoshikawa, D. Summers, M. Hikishima, Y. Ebihara, and Y. Kubota (2015), Formation process of relativistic electron flux through interaction with chorus emissions in the Earth's inner magnetosphere, J. Geophys. Res. Space Physics, 120, 9545-9562, doi:10.1002/2015JA021563. (2) Kubota, Y., and Y. Omura (2017), Rapid precipitation of radiation belt electrons induced by EMIC rising tone emissions localized in longitude inside and outside the plasmapause, J. Geophys. Res. Space Physics, 122, 293-309, doi:10.1002/2016JA023267.

  17. [Measures against Radiation Exposure Due to Large-Scale Nuclear Accident in Distant Place--Radioactive Materials in Nagasaki from Fukushima Daiichi Nuclear Power Plant].

    Yuan, Jun; Sera, Koichiro; Takatsuji, Toshihiro

    2015-01-01

    To investigate human health effects of radiation exposure due to possible future nuclear accidents in distant places and other various findings of analysis of the radioactive materials contaminating the atmosphere of Nagasaki due to the Fukushima Daiichi Nuclear Power Plant accident. The concentrations of radioactive materials in aerosols in the atmosphere of Nagasaki were measured using a germanium semiconductor detector from March 2011 to March 2013. Internal exposure dose was calculated in accordance with ICRP Publ. 72. Air trajectories were analyzed using NOAA and METEX web-based systems. (134)Cs and (137)Cs were repeatedly detected. The air trajectory analysis showed that (134)Cs and (137)Cs flew directly from the Fukushima Daiichi Nuclear Power Plant from March to April 2011. However, the direct air trajectories were rarely detected after this period even when (134)Cs and (137)Cs were detected after this period. The activity ratios ((134)Cs/(137)Cs) of almost all the samples converted to those in March 2011 were about unity. This strongly suggests that the (134)Cs and (137)Cs detected mainly originated from the Fukushima Daiichi Nuclear Power Plant accident in March 2011. Although the (134)Cs and (137)Cs concentrations per air volume were very low and the human health effects of internal exposure via inhalation is expected to be negligible, the specific activities (concentrations per aerosol mass) were relatively high. It was found that possible future nuclear accidents may cause severe radioactive contaminations, which may require radiation exposure control of farm goods to more than 1000 km from places of nuclear accidents.

  18. Noise emission from wind turbines in wake. Project report

    Dam Madsen, K.; Plovsing, B. (DELTA, Hoersholm (Denmark)); Soerensen, Thomas (EMD International A/S, Aalborg (Denmark)); Aagaard Madsen, H.; Bertagnolio, F. (Technical Univ. of Denmark, Risoe National Lab. for Sustainable Energy, Roskilde (Denmark))

    2011-03-15

    When installing wind turbines in clusters or wind farms the inflow conditions to the wind turbines can be disturbed due to wake effects from other wind turbines. The effect of wake on noise generation from wind turbines are described in this report. The work is based on measurements carried out on a M80 2 MW wind turbine. To investigate the relationship between the far field noise levels and the surface pressure and inflow angles measured by sensors on an instrumented wind turbine blade, a parabolic measurement system (PMMS) was designed and tested as part of this project. Based on the measurement results obtained with surface pressure sensors and results from the far field measurements using the PMMS it is concluded that: The variance of surface pressure at the trailing edge (TE) agrees with the theory with regard to variation of pressure spectra with varying inflow angle (AoA) to the blade. Low frequency TE surface pressure increases with increased AoA and high frequency surface pressure decreases with increased AoA. It seems that the TE surface pressure remains almost unaltered during wake operation. Results from the surface transducers at the leading edge (LE) and the inflow angles determined from the pitot tube indicates that the inflow at LE is more turbulent in wake for the same AoA and with a low frequency characteristic, thereby giving rise to more low frequency noise generated during wake operation. The far field measurements supports that on one hand there will be produced relative more low frequency noise due to a turbulent inflow to the blade and on the other hand there will be produced less noise in the broader frequency range/high frequency range due to a lower inflow angle caused by the wind deficit in the wake. The net effect of wake on the total noise level is unresolved. As a secondary result it is seen that noise observed from a position on the ground is related to directional effects of the noise radiated from the wind turbine blade. For an

  19. The associations between noise sensitivity, reported physical and mental health, perceived environmental quality, and noise annoyance

    Dirk Schreckenberg

    2010-01-01

    Full Text Available One hundred and ninety residents around Frankfurt Airport (46% female; 17-80 years were interviewed concerning noise annoyance due to transportation noise (aircraft, road traffic, perceived mental and physical health, perceived environmental quality, and noise sensitivity. The aim of the analyses was to test whether noise sensitivity reflects partly general environmental sensitivity and is associated with an elevated susceptibility for the perception of mental and physical health. In this study, the reported physical and mental health variables were not associated with noise exposure but with noise annoyance, and were interpreted to reflect nonspecific codeterminants of annoyance rather than noise effects. Noise sensitivity was found to influence total noise annoyance and aircraft noise annoyance but to a lesser degree annoyance due to road traffic noise. Noise sensitivity was associated with reported physical health, but not with reported mental health. Noise-sensitive persons reported poorer environmental quality in their residential area than less sensitive persons in particular with regard to air traffic (including the facets noise, pollution, and contaminations and quietness. Other aspects of the perceived quality of the environment were scarcely associated with noise sensitivity. This indicates that noise sensitivity is more specific and a reliable predictor of responses to noise from the dominant source (in this case air traffic rather than a predictor of the individual perception of the environmental quality in general.

  20. STUDY OF RADIATION EXPOSURE DUE TO RADON, THORON AND THEIR PROGENY IN THE INDOOR ENVIRONMENT OF RAJPUR REGION OF UTTARAKHAND HIMALAYA.

    Kandari, Tushar; Aswal, Sunita; Prasad, Mukesh; Pant, Preeti; Bourai, A A; Ramola, R C

    2016-10-01

    In the present study, the measurements of indoor radon, thoron and their progeny concentrations have been carried out in the Rajpur region of Uttarakhand, Himalaya, India by using LR-115 solid-state nuclear track detector-based time-integrated techniques. The gas concentrations have been measured by single-entry pin-hole dosemeter technique, while for the progeny concentrations, deposition-based Direct Thoron and Radon Progeny Sensor technique has been used. The radiation doses due to the inhalation of radon, thoron and progeny have also been determined by using obtained concentrations of radon, thoron and their progeny in the study area. The average radon concentration varies from 75 to 123 Bq m -3 with an overall average of 89 Bq m -3 The average thoron concentration varies from 29 to 55 Bq m -3 with an overall average of 38 Bq m -3 The total annual effective dose received due to radon, thoron and their progeny varies from 2.4 to 4.1 mSv y -1 with an average of 2.9 mSv y -1 While the average equilibrium factor for radon and its progeny was found to be 0.39, for thoron and its progeny, it was 0.06. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.