Simulated radiation effects in the superinsulating phase of titanium nitride films

Directory of Open Access Journals (Sweden)

Vujisić Miloš Lj.

2011-01-01

Full Text Available This paper investigates possible effects of alpha particle and ion beam irradiation on the properties of the superinsulating phase, recently observed in titanium nitride films, by using numerical simulation of particle transport. Unique physical properties of the superinsulating state are considered by relying on a two-dimensional Josephson junction array as a model of material structure. It is suggested that radiation-induced change of the Josephson junction charging energy would not affect the current-voltage characteristics of the superinsulating film significantly. However, it is theorized that a relapse to an insulating state with thermally activated resistance is possible, due to radiation-induced disruption of the fine-tuned granular structure. The breaking of Cooper pairs caused by incident and displaced ions may also destroy the conditions for a superinsulating phase to exist. Finally, even the energy loss to phonons can influence the superinsulating state, by increasing the effective temperature of the phonon thermostat, thereby reestablishing means for an energy exchange that can support Cooper pair tunneling.

Melting with convection and radiation in a participating phase change material

International Nuclear Information System (INIS)

Miranda Fuentes, Johann; Johannes, Kévyn; Kuznik, Frédéric; Cosnier, Matthieu; Virgone, Joseph

2013-01-01

Highlights: ► Modelling of the phase change with natural convection and radiation. ► Novel LBM MRT with phase change and energy equation. ► Diffuse radiation increases the heat transfer but not global behavior of phase change. - Abstract: This article presents a novel model to simulate melting of a phase change material, with natural convection and radiation. For the phase change problem, the enthalpy formulation is used. Energy equation is solved by finite differences, whereas fluid flow equations are solved by the lattice Boltzmann method. For radiation intensity, the radiative transfer equation is solved by the discrete ordinates method, and then radiation flux is added into the energy equation. The model is first validated with literature results. Then, a glass brick wall filled with a fatty acid is simulated to evaluate the heat transfer processes. The results show that (1) natural convection plays an important role in the transitional behaviour of the global heat transfer process and (2) the long wave radiation has few impacts on the melting process

Improved Metal-Polymeric Laminate Radiation Shielding, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — In this proposed Phase I program, a multifunctional lightweight radiation shield composite will be developed and fabricated. This structural radiation shielding will...

Radiation-induced phase transformation in ferromagnetic perovskite

Energy Technology Data Exchange (ETDEWEB)

Podsekin, A K; Dem' yanov, V V; Ivanova, V V; Venevtsev, Yu N [Nauchno-Issledovatel' skij Fiziko-Khimicheskij Inst., Moscow (USSR)

1976-12-01

An effect of neutron irradiation inducing a phase transition in ferromagnetic perovskite, Sr/sub 0.3/La/sub 0.7/MnO/sub 3/, has been discovered and studied. It is shown that a change in the Curie temperature is proportional to the dose of reactor irradiation. A decrease in the temperature of the phase transition with the concentration of radiation defects is accompanied by an increase in the electrical specific resistance and a change in the initial lattice parameters. It is shown that the radiation shift is due to at least two causes, viz. to an increase in the parameters of the elementary cell and the growth of the electrical specific resistance as a result of bounded electron states' forming on the radiation defects.

IPRT polarized radiative transfer model intercomparison project - Three-dimensional test cases (phase B)

Science.gov (United States)

Emde, Claudia; Barlakas, Vasileios; Cornet, Céline; Evans, Frank; Wang, Zhen; Labonotte, Laurent C.; Macke, Andreas; Mayer, Bernhard; Wendisch, Manfred

2018-04-01

Initially unpolarized solar radiation becomes polarized by scattering in the Earth's atmosphere. In particular molecular scattering (Rayleigh scattering) polarizes electromagnetic radiation, but also scattering of radiation at aerosols, cloud droplets (Mie scattering) and ice crystals polarizes. Each atmospheric constituent produces a characteristic polarization signal, thus spectro-polarimetric measurements are frequently employed for remote sensing of aerosol and cloud properties. Retrieval algorithms require efficient radiative transfer models. Usually, these apply the plane-parallel approximation (PPA), assuming that the atmosphere consists of horizontally homogeneous layers. This allows to solve the vector radiative transfer equation (VRTE) efficiently. For remote sensing applications, the radiance is considered constant over the instantaneous field-of-view of the instrument and each sensor element is treated independently in plane-parallel approximation, neglecting horizontal radiation transport between adjacent pixels (Independent Pixel Approximation, IPA). In order to estimate the errors due to the IPA approximation, three-dimensional (3D) vector radiative transfer models are required. So far, only a few such models exist. Therefore, the International Polarized Radiative Transfer (IPRT) working group of the International Radiation Commission (IRC) has initiated a model intercomparison project in order to provide benchmark results for polarized radiative transfer. The group has already performed an intercomparison for one-dimensional (1D) multi-layer test cases [phase A, 1]. This paper presents the continuation of the intercomparison project (phase B) for 2D and 3D test cases: a step cloud, a cubic cloud, and a more realistic scenario including a 3D cloud field generated by a Large Eddy Simulation (LES) model and typical background aerosols. The commonly established benchmark results for 3D polarized radiative transfer are available at the IPRT website (http

The clinical characteristics of the radiation pneumonia

International Nuclear Information System (INIS)

Zhang Fuzheng; Wang Mingzhi; Chen Jianjiang; Wang Zhongxiang; Mao Yongjie

2000-01-01

Objective: To analyse the clinical characteristics of the radiation pneumonia, sum the experience and the basis of the radiation pneumonia for its prevention and treatment. Method: Twenty three cases with radiation pneumonia from 1991 to 1998 were retrospectively analysed. Its clinical manifestation, chest X-ray, thoracic CT and blood routine were evaluated. Result: The acute manifestation was fever, cough, dyspnea, and the chronic manifestation was cough and insufficiency of pulmonary function. Conclusion: The prevention of radiation pneumonia is more important, high dose cortical steroids and antibiotics were prescribed during the acute stage and the chronic radiation pneumonia is irreversible

Ignition and combustion characteristics of metallized propellants, phase 2

Science.gov (United States)

Mueller, D. C.; Turns, S. R.

1994-01-01

Experimental and analytical investigations focusing on aluminum/hydrocarbon gel droplet secondary atomization and its effects on gel-fueled rocket engine performance are being conducted. A single laser sheet sizing/velocimetry diagnostic technique, which should eliminate sizing bias in the data collection process, has been designed and constructed to overcome limitations of the two-color forward-scatter technique used in previous work. Calibration of this system is in progress and the data acquisition/validation code is being written. Narrow-band measurements of radiant emission, discussed in previous reports, will be used to determine if aluminum ignition has occurred in a gel droplet. A one-dimensional model of a gel-fueled rocket combustion chamber, described in earlier reports, has been exercised in conjunction with a two-dimensional, two-phase nozzle code to predict the performance of an aluminum/hydrocarbon fueled engine. Estimated secondary atomization effects on propellant burnout distance, condensed particle radiation losses to the chamber walls, and nozzle two phase flow losses are also investigated. Calculations indicate that only modest secondary atomization is required to significantly reduce propellant burnout distances, aluminum oxide residual size, and radiation heat losses. Radiation losses equal to approximately 2-13 percent of the energy released during combustion were estimated, depending on secondary atomization intensity. A two-dimensional, two-phase nozzle code was employed to estimate radiation and nozzle two phase flow effects on overall engine performance. Radiation losses yielded a one percent decrease in engine Isp. Results also indicate that secondary atomization may have less effect on two-phase losses than it does on propellant burnout distance and no effect if oxide particle coagulation and shear induced droplet breakup govern oxide particle size. Engine Isp was found to decrease from 337.4 to 293.7 seconds as gel aluminum mass

Transverse phase space mapping of relativistic electron beams using optical transition radiation

Directory of Open Access Journals (Sweden)

G. P. Le Sage

1999-12-01

Full Text Available Optical transition radiation (OTR has proven to be a versatile and effective diagnostic for measuring the profile, divergence, and emittance of relativistic electron beams with a wide range of parameters. Diagnosis of the divergence of modern high brightness beams is especially well suited to OTR interference (OTRI techniques, where multiple dielectric or metal foils are used to generate a spatially coherent interference pattern. Theoretical analysis of measured OTR and OTRI patterns allows precise measurement of electron beam emittance characteristics. Here we describe an extension of this technique to allow mapping of divergence characteristics as a function of transverse coordinates within a measured beam. We present the first experimental analysis of the transverse phase space of an electron beam using all optical techniques. Comparing an optically masked portion of the beam to the entire beam, we measure different angular spread and average direction of the particles. Direct measurement of the phase-space ellipse tilt angle has been demonstrated using this optical masking technique.

Improved Metal-Polymeric Laminate Radiation Shielding, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — In this proposed Phase II program, builds on the phase I feaibility where a multifunctional lightweight radiation shield composite was developed and fabricated. This...

A comparative study on thermal, mechanical and dielectric characteristics of low density polyethylene crosslinked by radiation and chemical methods

International Nuclear Information System (INIS)

Kim, B.H.; Ling, D.Y.; Kim, J.S.

1976-01-01

A comparative study on thermal, static mechanical and dielectric characteristics were made over a temperature range of ca. 20 0 C to 320 0 C and a frequency range of KHZ band on low density polyethylene specimens crosslinked, respectively, by radiation and chemical method. The thermal property of both specimens shows that softening point appears to unchange by crosslinking however, melting and liquidizing temperatures attain rapid increase at the imitation of crosslinking. Mechanical properties show little difference to both specimens crosslinked by different method, further the behaviors were discussed in connection with the relaxation of molecular segments in amorphous phase. Dose dependent dielectric characteristics observed at ambient temperature under several fixed frequencies exhibit extremities at ca. 20 Mrad and the behaviors also were interpreted qualitatively by taking into consideration of dipole concentration change in amorphous phase together with the role of specimen geometry to the depth of oxidative layer. Observing frequency dependent dielectric characteristics, it was also proved that ionic conduction loss is appreciably greater in the specimen prepared by chemical method than that by radiation. (author)

Phase characteristics of rheograms. Original classification of phase-related changes of rheos

Directory of Open Access Journals (Sweden)

Mikhail Y. Rudenko

2014-05-01

Full Text Available The phase characteristics of a rheogram are described in literature in general only. The existing theory of impedance rheography is based on an analysis of the form of rheogram envelopes, but not on the phase-related processes and their interpretation according to the applicable laws of physics. The aim of the present paper is to describe the phase-related characteristics of a rheogram of the ascending aorta. The method of the heart cycle phase analysis has been used for this purpose. By synchronizing an ECG of the aorta and a rheogram, an analysis of specific changes in the aorta blood filling in each phase is provided. As a result, the phase changes of a rheogram associated with the ECG phase structure are described and tabulated for first time. The author hereof offers his own original classification of the phase-related changes of rheograms.

Drying characteristics of rough rice by far-infrared radiation heating

International Nuclear Information System (INIS)

Matsuoka, T.

1990-01-01

The relationship between the heat radiation characteristics of a far-infrared radiation heater and the drying characteristics of rough rice was investigated to determine the basic data required for utilization of far-infrared rays for drying rough rice. Results of investigations are discussed in detail

A Numerical Study on Effect of Gas-Phase Radiative Heat Loss on Extinction of Hydrogen Diffusion Flames

International Nuclear Information System (INIS)

Sohn, Chae Hoon

2007-01-01

Extinction characteristics of hydrogen-air diffusion flames are investigated numerically by adopting counterflow flame configuration. At various pressures, effect of radiative heat loss on flame extinction is examined. Only gas-phase radiation is considered here. Radiative heat loss depends on flame thickness, temperature, H 2 O concentration, and pressure. From flame structures at various pressures, flame thickness decreases with pressure, but its gradient decreases at high pressure. Flame temperature and mole fraction of H 2 O increase slightly with pressure. Accordingly, as pressure increases, radiative heat loss becomes dominant. When radiative heat loss is considered, radiation-induced extinction is observed at low strain rate in addition to transport-induced extinction. As pressure increases, flammable region shifts to the high-temperature region and then, shrunk to the point on the coordinate plane of flame temperature and strain rate

Radiation oncologists in 2000: demographic, professional, and practice characteristics

International Nuclear Information System (INIS)

Cypel, Yasmin; Sunshine, Jonathan H.; Schepps, Barbara

2002-01-01

Purpose: To describe the demographic, professional, and practice characteristics of radiation oncologists, emphasizing comparisons to data from a similar 1995 Survey. Methods and Materials: In spring 2000, we surveyed 603 randomly selected radiation oncologists by mail, using a one-page questionnaire - 455 responded. We weighted responses to make answers representative of all radiation oncologists in the United States. Results: Approximately 45% of post-training, professionally active, radiation oncologists were <45 years old and 22% were women. Forty-two percent of radiation oncologists in training were women. Thirty-three percent of radiation-oncology-only practices were solo practices. The greatest percentage of post-training, professionally active, radiation oncologists were in nonacademic private radiation oncology practices. Fifty-three percent of post-training, professionally active, radiation oncologists reported that their workload was about right. Eighteen percent of individuals 60-64 years old and approximately two-thirds of those ≥65 years old were not working (retired). The full-time equivalency of those aged 55-74 fell by 12 percentage points between 1995 and 2000. Conclusions: Most demographic, professional, and practice characteristics remained relatively constant between 1995 and 2000, with the exception of work status patterns. Radiation oncologists reported a more balanced workload than that reported by diagnostic radiologists. The surplus of radiation oncologists, which was predicted in the mid-1990s, was not demonstrated

Current-voltage characteristic of a resonant tunneling diode under electromagnetic radiation

Directory of Open Access Journals (Sweden)

N Hatefi Kargan

2013-09-01

Full Text Available  In this paper, current-voltage characteristic of a resonant tunneling diode under electromagnetic radiation has been calculated and compared with the results when there is no electromagnetic radiation. For calculating current -voltage characteristic, it is required to calculate the transmission coefficient of electrons from the well and barrier structures of this device. For calculating the transmission coefficient of electrons at the presence of electromagnetic radiation, Finite Difference Time Domain (FDTD method has been used and when there is no electromagnetic radiation Transfer Matrix Method (TMM and finite diffirence time domain method have been used. The results show that the presence of electromagnetic radiation causes resonant states other than principal resonant state (without presence of electromagnetic radiation to appear on the transmition coefficient curve where they are in distances from the principal peak and from each other. Also, the presence of electromagnetic radiation causes peaks other than principal peak to appear on the current-voltage characteristics of the device. Under electromagnetic radiation, the number of peaks on the current-voltage curve is smaller than the number of peaks on the current-voltage transmission coefficient. This is due to the fact that current-voltage curve is the result of integration on the energy of electrons, Thus, the sharper and low height peaks on the transmission coefficient do not appear on the current-voltage characteristic curve.

Stability of semiconductor memory characteristics in a radiation environment

OpenAIRE

Fetahović, I.; Vujisić, M.; Stanković, K.; Dolićanin, E.

2015-01-01

Radiation defects in electronic device can occur in a process of its fabrication or during use. Miniaturization trends in industry and increase in level of integration of electronic components have negative affect on component's behavior in a radiation environment. The aim of this paper is to analyze radiation effects in semiconductor memories and to establish how ionizing radiation influences characteristics and functionality of semiconductor memories. Both the experimental procedure and sim...

MECHANICAL CHARACTERISTICS OF THREE-PHASE INDUCTION MOTORS WITH SINGLE-PHASE POWER SUPPLY

Directory of Open Access Journals (Sweden)

V.S. Malyar

2016-06-01

Full Text Available Aim. Development of a method for calculating mechanical characteristics of three-phase induction motors with single-phase power supply. Methods. The developed algorithm is based on the high-adequacy mathematical model of motor and projection method for solving the boundary problem for equations of electrical circuits balance presented in the three-phase coordinate system. As a result of asymmetry of power supply to the stator windings, in steady state, flux-linkage and current change according to the periodic law. They are determined by solving the boundary problem. Results. The developed mathematical model allows determining periodic dependence of coordinates as a function of slip and, based on them, mechanical characteristics of motors. Academic novelty. The developed method relies on a completely new mathematical approach to calculation of stationary modes of nonlinear electromagnetic circuits, which allows obtaining periodic solution in a timeless domain. Practical value. Using the developed calculation algorithm, one can select capacitance required to start an induction motor with single-phase power supply and calculate static mechanical characteristics at a given capacitance.

Improving Climate Projections by Understanding How Cloud Phase affects Radiation

Science.gov (United States)

Cesana, Gregory; Storelvmo, Trude

2017-01-01

Whether a cloud is predominantly water or ice strongly influences interactions between clouds and radiation coming down from the Sun or up from the Earth. Being able to simulate cloud phase transitions accurately in climate models based on observational data sets is critical in order to improve confidence in climate projections, because this uncertainty contributes greatly to the overall uncertainty associated with cloud-climate feedbacks. Ultimately, it translates into uncertainties in Earth's sensitivity to higher CO2 levels. While a lot of effort has recently been made toward constraining cloud phase in climate models, more remains to be done to document the radiative properties of clouds according to their phase. Here we discuss the added value of a new satellite data set that advances the field by providing estimates of the cloud radiative effect as a function of cloud phase and the implications for climate projections.

Production and installation of equipments for radiation-induced graft polymerization in liquid phase and dipping techniques

International Nuclear Information System (INIS)

Seko, Noriaki; Kasai, Noboru; Tamada, Masao; Hasegawa, Shin; Katakai, Akio; Sugo, Takanobu

2005-01-01

Fibrous adsorbent which is synthesized by radiation induced graft polymerization on the trunk polymers such as polymer nonwoven fabrics and woven cloths exhibits an excellent selective adsorption against heavy metal ions and toxic gases at extremely low concentrations. Two equipments were installed to synthesize the metal-ion and gas adsorbents by means of the radiation-induced graft polymerization in the liquid phase and the dipping, respectively. In the reation chamber of the liquid phase reactor, the oxygen decreased to 100 ppm. The inside temperature was elevated at 80C. These characteristics satisfied the specification. The fabric transport can regulate the rate in the range from 1 to 10 m/min. The reactor for the dip grafting could reduce the inside oxygen to 100ppm and inside temperature could reach to 80C, also. The transport system is stable during the dip grafting reaction. The grafting of glycidyl methacrylate was carried out as a characteristic test. The degree of grafting was controlled in the range of 40-70%. The both equipments can graft the trunk polymer, 2000mm in maximum width and 1m in maximum diameter. This size is enough for confirmation practical scale synthesis. (author)

Origin, characteristics and detection of nuclear radiation

International Nuclear Information System (INIS)

Goettel, K.

1975-06-01

The report is an introduction into the physical principles of radiation protection. After a brief summary of the most significant experimental results and data on the atomic structure of the matter and after explaining the principles of atomic and nuclear structure, radioactive decay and its laws are dealt with. This is followed by a representation of the characteristics of nuclear radiation, its interaction with the matter as well as the biological effects. After a description of the measurement units for radioactivity and doses the most inportant methods for radiation detection and the principles of how detectors function are explained. (ORU/LN) [de

Miniature Active Space Radiation Dosimeter, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Space Micro will extend our Phase I R&D to develop a family of miniature, active space radiation dosimeters/particle counters, with a focus on biological/manned...

Temporal correlations between sensitivity to radiation-induced mitotic delay and the S phase of the sea urchin egg

International Nuclear Information System (INIS)

Rustad, R.C.; Viswanathan, G.; Antonellis, B.C.

1979-01-01

Separate samples of eggs from the sea urchin Arbacia punctulata were gamma irradiated (4kR) at different times after fertilisation and division delay measured. The results demonstrated a characteristic post-fertilisation pattern of a rise in sensitivity to radiation-induced mitotic delay, followed by a biphasic decrease in sensitivity to a refractory period. Measurements of the cumulative incorporation of 3 H-TdR showed that the first period of decreasing radiation sensitivity was closely associated with the bulk synthesis of DNA (S phase). (U.K.)

Two-phase flow characteristics in BWRs

International Nuclear Information System (INIS)

Katono, Kenichi; Aoyama, Goro; Nagayoshi, Takuji; Yasuda, Kenichi; Nishida, Koji

2014-01-01

Reliable prediction of two-phase flow characteristics is important for safety and economy improvements of BWR plants. We have been developing two-phase flow measurement tools and techniques for BWR thermal hydraulic conditions, such as a 3D time-averaged X-ray CT system, an ultrasonic liquid film sensor and a wire-mesh sensor. We applied the developed items in experiments using the multi-purpose steam-water test facility known as HUSTLE, which can simulate two-phase thermal-hydraulic conditions in a BWR reactor pressure vessel, and we constructed a detailed instrumentation database. We validated a 3D two-phase flow simulator using the database and developed the reactor internal two-phase flow analysis system. (author)

Application of Monte Carlo method in determination of secondary characteristic X radiation in XFA

International Nuclear Information System (INIS)

Roubicek, P.

1982-01-01

Secondary characteristic radiation is excited by primary radiation from the X-ray tube and by secondary radiation of other elements so that excitations of several orders result. The Monte Carlo method was used to consider all these possibilities and the resulting flux of characteristic radiation was simulated for samples of silicate raw materials. A comparison of the results of these computations with experiments allows to determine the effect of sample preparation on the characteristic radiation flux. (M.D.)

Some characteristics and effects of natural radiation

International Nuclear Information System (INIS)

Mc Laughlin, J.P.

2015-01-01

Since life first appeared on the Earth, it has, in all its subsequent evolved forms including human, been exposed to natural radiation in the environment both from terrestrial and extra-terrestrial sources. Being an environmental mutagen, ionising natural radiation may have played a role of some significance in the evolution of early life forms on Earth. It has been estimated by United Nations Scientific Committee on the Effects of Atomic Radiation that at the present time, exposure to natural radiation globally results in an annual average individual effective dose of about 2.4 mSv. This represents about 80 % of the total dose from all sources. The three most important components of natural radiation exposure are cosmic radiation, terrestrial radioactivity and indoor radon. Each of these components exhibits both geographical and temporal variabilities with indoor radon exposure being the most variable and also the largest contributor to dose for most people. In this account, an overview is given of the characteristics of the main components of the natural radiation environment and some of their effects on humans. In the case of cosmic radiation, these range from radiation doses to aircrew and astronauts to the controversial topic of its possible effect on climate change. In the case of terrestrial natural radiation, accounts are given of a number of human exposure scenarios. (author)

Acoustic radiation force control: Pulsating spherical carriers.

Science.gov (United States)

Rajabi, Majid; Mojahed, Alireza

2018-02-01

The interaction between harmonic plane progressive acoustic beams and a pulsating spherical radiator is studied. The acoustic radiation force function exerted on the spherical body is derived as a function of the incident wave pressure and the monopole vibration characteristics (i.e., amplitude and phase) of the body. Two distinct strategies are presented in order to alter the radiation force effects (i.e., pushing and pulling states) by changing its magnitude and direction. In the first strategy, an incident wave field with known amplitude and phase is considered. It is analytically shown that the zero- radiation force state (i.e., radiation force function cancellation) is achievable for specific pulsation characteristics belong to a frequency-dependent straight line equation in the plane of real-imaginary components (i.e., Nyquist Plane) of prescribed surface displacement. It is illustrated that these characteristic lines divide the mentioned displacement plane into two regions of positive (i.e., pushing) and negative (i.e., pulling) radiation forces. In the second strategy, the zero, negative and positive states of radiation force are obtained through adjusting the incident wave field characteristics (i.e., amplitude and phase) which insonifies the radiator with prescribed pulsation characteristics. It is proved that zero radiation force state occurs for incident wave pressure characteristics belong to specific frequency-dependent circles in Nyquist plane of incident wave pressure. These characteristic circles divide the Nyquist plane into two distinct regions corresponding to positive (out of circles) and negative (in the circles) values of radiation force function. It is analytically shown that the maximum amplitude of negative radiation force is exactly equal to the amplitude of the (positive) radiation force exerted upon the sphere in the passive state, by the same incident field. The developed concepts are much more deepened by considering the required

Phase-change radiative thermal diode

OpenAIRE

Ben-Abdallah, Philippe; Biehs, Svend-Age

2013-01-01

A thermal diode transports heat mainly in one preferential direction rather than in the opposite direction. This behavior is generally due to the non-linear dependence of certain physical properties with respect to the temperature. Here we introduce a radiative thermal diode which rectifies heat transport thanks to the phase transitions of materials. Rectification coefficients greater than 70% and up to 90% are shown, even for small temperature differences. This result could have important ap...

Principles of interaction of ionizing radiation with matter and basic radiation chemistry processes

International Nuclear Information System (INIS)

Santar, I.; Bednar, J.

1976-01-01

The basic principles are given of the interaction of ionizing radiation with matter and the main trends are pointed out in radiation chemistry. A brief characteristics is given of the basic radiation chemical processes in gases and in the condensed phase, namely in water and in organic substances. (B.S.)

Characteristics of withstanding radiation damage of InP crystals and devices

International Nuclear Information System (INIS)

Yamaguchi, Masafumi; Ando, Koshi

1988-01-01

Recently, the authors discovered that the characteristics of with standing radiation damage of InP crystals and devices (solar cells) are superior to those of Si and GaAs crystals and devices. Also the restoration phenomena at room temperature of radiation deterioration and the accelerated anneal phenomena by light irradiation and the injection of other minority, carriers in InP system devices were found. Such excellent characteristics suggested that InP devices are promising for the use in space. In this paper, taking an example of solar cells, the radiation resistance characteristics and their mechanism of InP crystals and devices are reported, based on the results of analysis by deep level transient spectroscopy and others. In InP solar cells, the high efficiency of photoelectric conversion was maintained even in the high dose irradiation of 1 MeV electron beam. As the carrier concentration in InP crystals is higher, they are stronger against radiation. With the increase of carrier concentration, the rate of anneal of radiation deterioration at room temperature increased. The accelerated anneal effect by minority carrier injection was remarkable in n + -p junction cells. The excellent characteristics of InP crystals are due to the formation of Frenkel defects of P and their instability. (K.I.)

Studies on the radiation absorption characteristics of various rocks

International Nuclear Information System (INIS)

Rahman, K.N.; Abdullah, S.A.; Gazzaz, M.A.

1984-05-01

Radiation absorption characteristics of nine different rocks, namely, ferrugenous quartz, metabasalt, larvikite, coarse grained diorite, coarse grained granite, coarse grained alkali granite, marble, quartz mica schist, and metamorphosed rock are studied. The rocks were collected from Jeddah, Makkah, Mina and Taif areas. Special attention was given on the availability, compactness, physical formation and uniform composition in selecting the rocks. The rocks were identified by optical method and their elemental composition determined by chemical analysis. The data were used to calculate the effective atomic numbers, half value layers mass and linear attenuation coefficients. The half value layers and the linear attenuation coefficientsof these rocks were determined experimentally using Am-241, Cs-137,and Co-60 sources. The results are compared with those obtained by theoretical calculations and agrre within 10%. Most of the rocks show much higher radiation attenuation characteristics than the standard concrete. Rocks containing higher percentage of Fe, Ca, Ti, and Mn show much higher radiation absorption characteristics than concrete. Only granites are found to be almost equivalent to concrete. 12 Ref

Determination of electron bunch shape using transition radiation and phase-energy measurements

International Nuclear Information System (INIS)

Crosson, E.R.; Berryman, K.W.; Richman, B.A.

1995-01-01

We present data comparing microbunch temporal information obtained from electron beam phase-energy measurements with that obtained from transition radiation auto-correlation measurements. The data was taken to resolve some of the ambiguities in previous transition radiation results. By measuring the energy spectrum of the electron beam as a function of its phase relative to the accelerating field, phase-energy information was extracted. This data was analyzed using tomographic techniques to reconstruct the phase-space distribution assuming an electron energy dependence of E(var-phi) = E o + E acc cos(var-phi), where E o is the energy of an electron entering the field, E acc is the peak energy gain, and var-phi is the phase between the crest of the RF wave and an electron. Temporal information about the beam was obtained from the phase space distribution by taking the one dimensional projection along the time axis. We discuss the use of this technique to verify other transition radiation analysis methods

Determination of electron bunch shape using transition radiation and phase-energy measurements

Energy Technology Data Exchange (ETDEWEB)

Crosson, E.R.; Berryman, K.W.; Richman, B.A. [Stanford Univ., CA (United States)] [and others

1995-12-31

We present data comparing microbunch temporal information obtained from electron beam phase-energy measurements with that obtained from transition radiation auto-correlation measurements. The data was taken to resolve some of the ambiguities in previous transition radiation results. By measuring the energy spectrum of the electron beam as a function of its phase relative to the accelerating field, phase-energy information was extracted. This data was analyzed using tomographic techniques to reconstruct the phase-space distribution assuming an electron energy dependence of E({var_phi}) = E{sub o} + E{sub acc}cos({var_phi}), where E{sub o} is the energy of an electron entering the field, E{sub acc} is the peak energy gain, and {var_phi} is the phase between the crest of the RF wave and an electron. Temporal information about the beam was obtained from the phase space distribution by taking the one dimensional projection along the time axis. We discuss the use of this technique to verify other transition radiation analysis methods.

Characteristics of radiation field in living environment, 2

International Nuclear Information System (INIS)

Nagaoka, Toshi; Sakamoto, Ryuichi; Tsutsumi, Masahiro; Saito, Kimiaki; Moriuchi, Shigeru

1990-01-01

A series of environmental radiation survey was carried out on train lines within Tokyo metropolitan area to clarify the characteristics of radiation field in living environment. Eleven JR, 18 private and 10 subway lines were surveyed, which cover 97% of whole train lines in Tokyo district in terms of annual number of passengers. The characteristics of environmental radiation field on train lines were discussed. The mean absorbed dose rate in air due to γ-rays on the subway lines was higher than those on the JR and private lines. It is due to the difference in the radioactivity concentration and the distribution of surrounding materials as the γ-ray sources. On the other hand, the mean dose rate due to cosmic-rays on the subway lines was lower than those on the JR and private lines. It is due to the shielding effect of the upper materials such as soil or building materials of tunnels. The mean dose rates for the JR, private and subway lines were calculated using these obtained data. Though the ratio of mean dose rate of γ-rays to that of cosmic-rays for the subway lines was different from those for the JR and private lines, the sum of γ- and cosmic-ray dose rates for the JR, private and subway lines were comparable, 40∼50 nGy/h for any of them. These data will be useful for a precise and realistic evaluation of collective dose, considering the life style of the public and the variation characteristics of environmental radiation. (author)

The baffle influence on sound radiation characteristics of a plate

Directory of Open Access Journals (Sweden)

Bao Liu

2017-01-01

Full Text Available The acoustic radiation characteristics of the baffle plates and unbaffle plates are calculated and compared by single-layer potential and double-layer potential. Based on the boundary integral equation, the sound pressure integral equation of the baffle and the baffle are deduced respectively. According to the boundary compatibility condition, the sound pressure and the vibration velocity of the plates are obtained. Further, the dynamic equation of the structure is substituted into the vibration equation in the form of the baffle plate and the baffle plate. The sound pressure difference and the displacement of a plate surface are in the form of the vibration mode superposition and the acoustic radiation impedance of the double integral form is obtained, which determines vibration mode coefficient and sound radiation parameters. The effect of the baffle on the acoustic radiation characteristics of the thin plate is analyzed by comparing the acoustic radiation parameters with the simple and simple rectangular plate in water.

X-ray elastography: Modification of x-ray phase contrast images using ultrasonic radiation pressure

International Nuclear Information System (INIS)

Hamilton, Theron J.; Bailat, Claude; Rose-Petruck, Christoph; Diebold, Gerald J.; Gehring, Stephan; Laperle, Christopher M.; Wands, Jack

2009-01-01

The high resolution characteristic of in-line x-ray phase contrast imaging can be used in conjunction with directed ultrasound to detect small displacements in soft tissue generated by differential acoustic radiation pressure. The imaging method is based on subtraction of two x-ray images, the first image taken with, and the second taken without the presence of ultrasound. The subtraction enhances phase contrast features and, to a large extent, removes absorption contrast so that differential movement of tissues with different acoustic impedances or relative ultrasonic absorption is highlighted in the image. Interfacial features of objects with differing densities are delineated in the image as a result of both the displacement introduced by the ultrasound and the inherent sensitivity of x-ray phase contrast imaging to density variations. Experiments with ex vivo murine tumors and human tumor phantoms point out a diagnostic capability of the method for identifying tumors.

Cooling Characteristic Analysis of Transformer's Radiator

International Nuclear Information System (INIS)

Kim, Hyun Jae; Yang, Si Won; Kim, Won Seok; Kweon, Ki Yeoung; Lee, Min Jea

2007-01-01

A transformer is a device that changes the current and voltage by electricity induced between coil and core steel, and it is composed of metals and insulating materials. In the core of the transformer, the thermal load is generated by electric loss and the high temperature can make the break of insulating. So we must cool down the temperature of transformer by external radiators. According to cooling fan's usage, there are two cooling types, OA(Oil Natural Air Natural) and FA(Oil Natural Air Forced). For this study , we used Fluent 6.2 and analyzed the cooling characteristic of radiator. we calculated 1-fin of detail modeling that is similar to honeycomb structure and multi-fin(18-fin) calculation for OA and FA types. For the sensitivity study, we have different positions(side, under) of cooling fans for forced convection of FA type. The calculation results were compared with the measurement data which obtained from 135.45/69kV ultra transformer flowrate and temperature test. The aim of the study is to assess the Fluent code prediction on the radiator calculation and to use the data for optimizing transformer radiator design

Phase characteristics of earthquake accelerogram and its application

International Nuclear Information System (INIS)

Ohsaki, Y.; Iwasaki, R.; Ohkawa, I.; Masao, T.

1979-01-01

As the input earthquake motion for seismic design of nuclear power plant structures and equipments, an artificial time history compatible with smoothed design response spectrum is frequently used. This paper deals with a wave generation technique based on phase characteristics in earthquake accelerograms as an alternate of envelope time function. The concept of 'phase differences' distribution' is defined to represent phase characteristics of earthquake motion. The procedure proposed in this paper consists of following steps; (1) Specify a design response spectrum and derive a corresponding initial modal amplitude. (2) Determine a phase differences' distribution corresponding to an envelope function, the shape of which is dependent on magnitude and epicentral distance of an earthquake. (3) Derive the phase angles at all modal frequencies from the phase differences' distribution. (4) Generate a time history by inverse Fourier transeform on the basis of the amplitudes and the phase angles thus determined. (5) Calculate the response spectrum. (6) Compare the specified and calculated response spectra, and correct the amplitude at each frequency so that the response spectrum will be consistent with the specified. (7) Repeat the steps 4 through 6, until the specified and calculated response spectra become consistent with sufficient accuracy. (orig.)

Sex Differences in Countermovement Jump Phase Characteristics

Directory of Open Access Journals (Sweden)

John J. McMahon

2017-01-01

Full Text Available The countermovement jump (CMJ is commonly used to explore sex differences in neuromuscular function, but previous studies have only reported gross CMJ measures or have partly examined CMJ phase characteristics. The purpose of this study was to explore differences in CMJ phase characteristics between male and female athletes by comparing the force-, power-, velocity-, and displacement-time curves throughout the entire CMJ, in addition to gross measures. Fourteen men and fourteen women performed three CMJs on a force platform from which a range of kinetic and kinematic variables were calculated via forward dynamics. Jump height (JH, reactive strength index modified, relative peak concentric power, and eccentric and concentric displacement, velocity, and relative impulse were all greater for men (g = 0.58–1.79. Relative force-time curves were similar between sexes, but relative power-, velocity-, and displacement-time curves were greater for men at 90%–95% (immediately before and after peak power, 47%–54% (start of eccentric phase and 85%–100% (latter half of concentric phase, and 65%–87% (bottom of countermovement and initial concentric phase of normalized jump time, respectively. The CMJ distinguished between sexes, with men demonstrating greater JH through applying a larger concentric impulse and, thus, achieving greater velocity throughout most of the concentric phase, including take-off.

Research on infrared radiation characteristics of Pyromark1200 high-temperature coating

Science.gov (United States)

Song, Xuyao; Huan, Kewei; Dong, Wei; Wang, Jinghui; Zang, Yanzhe; Shi, Xiaoguang

2014-11-01

Pyromark 1200 (Tempil Co, USA), which is a type of high-temperature high-emissivity coating, is silicon-based with good thermal radiation performance. Its stably working condition is at the temperature range 589~922 K thus a wide range of applications in industrial, scientific research, aviation, aerospace and other fields. Infrared emissivity is one of the most important factors in infrared radiation characteristics. Data on infrared spectral emissivity of Pyromark 1200 is in shortage, as well as the reports on its infrared radiation characteristics affected by its spray painting process, microstructure and thermal process. The results of this research show that: (1) The coating film critical thickness on the metal base is 10μm according to comparison among different types of spray painting process, coating film thickness, microstructure, which would influence the infrared radiation characteristics of Pyromark 1200 coating. The infrared spectral emissivity will attenuate when the coating film thickness is lower or much higher than that. (2) Through measurements, the normal infrared radiation characteristics is analyzed within the range at the temperature range 573~873 K under normal atmospheric conditions, and the total infrared spectral emissivity of Pyromark 1200 coating is higher than 0.93 in the 3~14 μm wavelength range. (3) The result of 72-hour aging test at the temperature 673 K which studied the effect of thermal processes on the infrared radiation characteristics of the coating shows that the infrared spectral emissivity variation range is approximately 0.01 indicating that Pyromark 1200 coating is with good stability. Compared with Nextel Velvet Coating (N-V-C) which is widely used in optics field, Pyromark 1200 high-temperature coating has a higher applicable temperature and is more suitable for spraying on the material surface which is in long-term operation under high temperature work conditions and requires high infrared spectral emissivity.

Brightness and coherence of radiation from undulators and high-gain free electron lasers

International Nuclear Information System (INIS)

Kim, Kwang-Je.

1987-03-01

The purpose of this paper is to review the radiation characteristics of undulators and high-gain free electron lasers (FELs). The topics covered are: a phase-space method in wave optics and synchrotron radiation, coherence from the phase-space point of view, discussions of undulator performances in next-generation synchrotron radiation facility and the characteristics of the high-gain FELs and their performances

Second law analysis of coupled conduction-radiation heat transfer with phase change

International Nuclear Information System (INIS)

Makhanlall, D.; Liu, L.H.

2010-01-01

This work considers an exergy-based analysis of two-dimensional solid-liquid phase change processes in a square cavity enclosure. The phase change material (PCM) concerns a semi-transparent absorbing, emitting and anisotropically scattering medium with constant thermodynamic properties. The enthalpy-based energy equation is solved numerically using computational fluid dynamics. Once the energy equation is solved, local exergy loss due to heat conduction and radiative heat transfer during the phase change process is calculated by post processing procedures. In this work, the radiation exergy loss in the medium and at the enclosure boundary is taken into consideration. It is found that radiation exergy loss is significant in the high-temperature phase change process. Parametric investigation is also carried out to study the effects of Stefan number, Biot number, Planck number, single scattering albedo and wall emissivity on exergy loss. The results show that the total exergy loss increases with Biot number, single scattering albedo and wall emissivity. The second law effects of the conduction-radiation coupling in the energy equation are also shown in this work. (authors)

Influence of radiative heat and mass transfer mechanism in system “water droplet-high-temperature gases” on integral characteristics of liquid evaporation

Directory of Open Access Journals (Sweden)

Glushkov Dmitrii O.

2015-01-01

Full Text Available Physical and mathematical (system of differential equations in private derivatives models of heat and mass transfer were developed to investigate the evaporation processes of water droplets and emulsions on its base moving in high-temperature (more than 1000 K gas flow. The model takes into account a conductive and radiative heat transfer in water droplet and also a convective, conductive and radiative heat exchange with high-temperature gas area. Water vapors characteristic temperature and concentration in small wall-adjacent area and trace of the droplet, numerical values of evaporation velocities at different surface temperature, the characteristic time of complete droplet evaporation were determined. Experiments for confidence estimation of calculated integral characteristics of processes under investigation - mass liquid evaporation velocities were conducted with use of cross-correlation recording video equipment. Their satisfactory fit (deviations of experimental and theoretical velocities were less than 15% was obtained. The influence of radiative heat and mass transfer mechanism on characteristics of endothermal phase transformations in a wide temperature variation range was established by comparison of obtained results of numerical simulation with known theoretical data for “diffusion” mechanisms of water droplets and other liquids evaporation in gas.

Radiational and energetic characteristics of diatomic molecules (data base)

International Nuclear Information System (INIS)

Kuznetsova, L.A.; Pazyuk, E.A.; Stolyarov, A.V.

1993-01-01

Data base on radiational and energetic characteristics of diatomic molecules was created. The base consists of two parts: reference system and recommended data system. The reference system contains the information about studies of radiational and energetic parameters of more than 1500 electronic states and 1700 electron transfers for ∼ 350 diatomic molecules and their ions. The base bibliography includes ∼ 3000 publications. 11 refs., 1 figs

Phase characteristics of solid-state amplifiers in sub-harmonic bunchers

International Nuclear Information System (INIS)

Liu Rong; Ma Xinpeng; Zhao Fengli; Wang Xiangjian; Wang Guangwei; Huang Yongqing; Zhang Donghui

2009-01-01

To study the phase characteristics of solid-state amplifiers(20 kW/142.8 MHz,10 kW/571.2 MHz) in sub-harmonic bunchers(SHBs) of the BEPC II linear accelerator, phase shift in pulse and phase stability are measured using a digital measurement method based on field programmable gate array(FPGA). The hardware of the measurement system includes the frequency synthesizer, digital signal processing board(FPGA) and PC, and the software includes an internal algorithm on FPGA, communication procedures and PC client interface procedures. The measurement results of phase characteristics are consistent with the actual situation, which is the basis for the further implement of phase compensation in SHBs. (authors)

Augmented Quadruple-Phase Contrast Media Administration and Triphasic Scan Protocol Increases Image Quality at Reduced Radiation Dose During Computed Tomography Urography.

Science.gov (United States)

Saade, Charbel; Mohamad, May; Kerek, Racha; Hamieh, Nadine; Alsheikh Deeb, Ibrahim; El-Achkar, Bassam; Tamim, Hani; Abdul Razzak, Farah; Haddad, Maurice; Abi-Ghanem, Alain S; El-Merhi, Fadi

The aim of this article was to investigate the opacification of the renal vasculature and the urogenital system during computed tomography urography by using a quadruple-phase contrast media in a triphasic scan protocol. A total of 200 patients with possible urinary tract abnormalities were equally divided between 2 protocols. Protocol A used the conventional single bolus and quadruple-phase scan protocol (pre, arterial, venous, and delayed), retrospectively. Protocol B included a quadruple-phase contrast media injection with a triphasic scan protocol (pre, arterial and combined venous, and delayed), prospectively. Each protocol used 100 mL contrast and saline at a flow rate of 4.5 mL. Attenuation profiles and contrast-to-noise ratio of the renal arteries, veins, and urogenital tract were measured. Effective radiation dose calculation, data analysis by independent sample t test, receiver operating characteristic, and visual grading characteristic analyses were performed. In arterial circulation, only the inferior interlobular arteries in both protocols showed a statistical significance (P contrast-to-noise ratio than protocol A (protocol B: 22.68 ± 13.72; protocol A: 14.75 ± 5.76; P contrast media and triphasic scan protocol usage increases the image quality at a reduced radiation dose.

Degradation characteristics of waste polyurethane by radiation

Energy Technology Data Exchange (ETDEWEB)

Park, Jong Seok; Ahn, Sung Jun; Gwon Hui Jeong; Jeong, Sung In; Nho, Young Chang; Lim, Youn Mook [Research Division for Industry and Environment, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

2017-06-15

Polyurethane (PU) is a very popular polymer that is used in a variety of applications due to its good mechanical, thermal, and chemical properties. However, waste PU recycling has received significant attention due to environmental issues. The aim of this work was to investigate the degradation characteristics of waste PU to recycle. Degradation of waste PU was carried out using a radiation techniques. Waste PUs were exposed to a gamma {sup 60}Co sources. To verify degradation, the irradiated PUs were characterized using FT-IR, gel permeation chromatography (GPC), and their thermal/mechanical properties are reported. When the radiation dose was 500 kGy, the molecular weight of the waste PU drastically decreased. Also, the mechanical properties of waste PU were approximately 4 times lower than those of non-irradiated PU. This study has confirmed the possibility of making fine particle of waste PU for recycling through radiation degradation techniques.

Characteristic aspects of pion-condensed phases

International Nuclear Information System (INIS)

Takatsuka, Tatsuyuki; Tamagaki, Ryozo; Tatsumi, Toshitaka.

1993-01-01

Characteristic aspects of pion-condensed phases are described in a simple model, for the system involving only nucleons and pions which interact through the π-N P-wave interaction. We consider one typical version in each of three kinds of pion condensation; the one of neutral pions (π 0 ), the one of charged pions (π C ) and the combined one in which both the π 0 and π C condensations are coexistent. Emphasis is put on the description to clarify the novel structures of the nucleon system which are realized in the pion-condensed phases. At first, it is shown that the π 0 condensation is equivalent to the particular nucleonic phase realized by a structure change of the nucleon system, where the attractive first-order effect of the one-pion-exchange (OPE) tensor force is brought about coherently. The aspects of this phase are characterized by the layered structure with a specific spin-isospin order with one-dimensional localization (named the ALS structure in short), which provides the source function for the condensed π 0 field. We utilize both descriptions with use of fields and potentials for the π 0 condensation. Next, the π C condensation realized in neutron-rich matter is described by adopting a version of the traveling condensed wave. In this phase, the nucleonic structure becomes the Fermi gas consisting of quasi-neutrons described by a superposition of neutron and proton. In this sense the structure change of the nucleon system for the π C condensation is moderate, and the field description is suitable. Finally, we describe a coexistent pion condensation, in which both the π 0 and π C condensations coexist without interference in such a manner that the π C condensation develops in the ALS structure. The model adopted here provides us with the characteristic aspects of the pion-condensed phases persisting in the realistic situation, where other ingredients affecting the pion condensation are taken into account. (author)

Ionizing radiation effect on physico-mechanical characteristics of thermoplastic polymer materials

International Nuclear Information System (INIS)

Stankevich, V.M.; Pleskachevsky, Yu.M.; Smirnov, V.V.

2001-01-01

Investigation results in the field of ionizing radiation effect on structure and physico-mechanical properties of novel polymer materials are presented. The materials under study are various grades of PETP, PA-6 and polyethylene concentrate of technical carbon (PECC) commercially produced and extensively used in Belarus and abroad. It has been proved using EPR, thermomechanical and gel analyses that a combined effect of ionizing radiation within 0 to 10 MGy of absorbed dose range under different concentrations of mineral fillers (TiO 2 , kaolin, carbon black, graphite) and intensive cross-linking processes in amorphous phase are able to considerably improve strength characteristics of the studied polymers and their compositions. Most informative parameter was found to be breaking strength at rapture (σ r ) which enables to estimate the character of ionizing effect on the targets. At 0.01-0.05 MGy absorbed dose the highest σ r was shown as compared to initial PETP by the following materials: PN grade - 9 times, D - two and a half. When absorbed dose of PETP reached 0.2 MGy, σ r of PN surpassed the initial material 7.8 times, that of D - by 30% and E - by 1,5%. This is the evidence of elevated resistance of named materials to ionizing radiation in contrast to non-filled PETP 215. Growth of σ r in PA-6 has been noticed at absorbed dose above 2 MGy in response to maximum gel-formation values. Abrupt reduction of the studied parameters of PP upon irradiation is attributed to its destruction. Domination of cross-linking processes has been observed in PEVP and PECC which reduces macromolecular mobility and elasticity of the material as a whole but promotes polymer strengthening. Drop of PEVP impact strength can be related to its embrittlement. Presence of the filler (carbon black) in PECC at the initial stage of exposure resulted in improvement of studied parameters. Their further impairment is the result of limited mobility of macromolecules owing to cross-linking in

Phase Aberration and Attenuation Effects on Acoustic Radiation Force-Based Shear Wave Generation.

Science.gov (United States)

Carrascal, Carolina Amador; Aristizabal, Sara; Greenleaf, James F; Urban, Matthew W

2016-02-01

Elasticity is measured by shear wave elasticity imaging (SWEI) methods using acoustic radiation force to create the shear waves. Phase aberration and tissue attenuation can hamper the generation of shear waves for in vivo applications. In this study, the effects of phase aberration and attenuation in ultrasound focusing for creating shear waves were explored. This includes the effects of phase shifts and amplitude attenuation on shear wave characteristics such as shear wave amplitude, shear wave speed, shear wave center frequency, and bandwidth. Two samples of swine belly tissue were used to create phase aberration and attenuation experimentally. To explore the phase aberration and attenuation effects individually, tissue experiments were complemented with ultrasound beam simulations using fast object-oriented C++ ultrasound simulator (FOCUS) and shear wave simulations using finite-element-model (FEM) analysis. The ultrasound frequency used to generate shear waves was varied from 3.0 to 4.5 MHz. Results: The measured acoustic pressure and resulting shear wave amplitude decreased approximately 40%-90% with the introduction of the tissue samples. Acoustic intensity and shear wave displacement were correlated for both tissue samples, and the resulting Pearson's correlation coefficients were 0.99 and 0.97. Analysis of shear wave generation with tissue samples (phase aberration and attenuation case), measured phase screen, (only phase aberration case), and FOCUS/FEM model (only attenuation case) showed that tissue attenuation affected the shear wave generation more than tissue aberration. Decreasing the ultrasound frequency helped maintain a focused beam for creation of shear waves in the presence of both phase aberration and attenuation.

Discrimination of radiation quality through second harmonic out-of-phase cw-ESR detection.

Science.gov (United States)

Marrale, Maurizio; Longo, Anna; Brai, Maria; Barbon, Antonio; Brustolon, Marina

2014-02-01

The ability to discriminate the quality of ionizing radiation is important because the biological effects produced in tissue strongly depends on both absorbed dose and linear energy transfer (LET) of ionizing particles. Here we present an experimental electron spin resonance (ESR) analysis aimed at discriminating the effective LETs of various radiation beams (e.g., 19.3 MeV protons, (60)Co photons and thermal neutrons). The measurement of the intensities of the continuous wave spectrometer signal channel first harmonic in-phase and the second harmonic out-of-phase components are used to distinguish the radiation quality. A computational analysis, was carried out to evaluate the dependence of the first harmonic in-phase and second harmonic out-of-phase components on microwave power, modulation amplitude and relaxation times, and highlights that these components could be used to point out differences in the relaxation times. On the basis of this numerical analysis the experimental results are discussed. The methodology described in this study has the potential to provide information on radiation quality.

The effect of radiation intensity on diode characteristics of silicon solar cells

International Nuclear Information System (INIS)

Asgerov, Sh.Q; Agayev, M.N; Hasanov, M.H; Pashayev, I.G

2008-01-01

In order to explore electro-physical properties of silicon solar cells, diode characteristics and ohmic properties of Al - Ni / (n+) - Si contact has been studied. Diode characteristics have been studied on a wide temperature range and on various radiation intensity, so this gives us the ability to observe the effect of the radiation and the temperature on electro-physical properties of under study solar cells. Volt-Ampere characteristics of the ohmic contacts of the silicon solar cells have been presented. As well as contact resistance and mechanism of current transmission has been identified.

Preliminary study on X-ray phase contrast imaging using synchrotron radiation facility

International Nuclear Information System (INIS)

Xiong Zhuang; Wang Jianhua; Yu Yongqiang; Jiang Shiping; Chen Yang; Tian Yulian

2006-01-01

Objective: To study the methodology of X-ray phase contrast imaging using synchrotron radiation, and evaluate the quality of phase contrast images. Methods: Several experiments to obtain phase contrast images and absorption contrast images of various biological samples were conducted in Beijing Synchrotron Radiation Facility (BSRF), and then these images were interpreted to find out the difference between the two kinds of imaging methods. Results: Satisfactory phase contrast images of these various samples were obtained, and the quality of these images was superior to that obtained with absorption contrast imaging. The phase contrast formation is based on the phenomenon of fresnel diffraction which transforms phase shifts into intensity variations upon a simple act of free-space propagation, so it requires highly coherent X-rays and appropriate distance between sample and detector. This method of imaging is very useful in imaging of low-absorption objects or objects with little absorption variation, and its resolution is far higher than that of the conventional X-ray imaging. The photographs obtained showed very fine inner microstructure of the biological samples, and the smallest microstructure to be distinguished is within 30-40 μm. There is no doubt that phase contrast imaging has a practical applicability in medicine. Moreover, it improves greatly the efficiency and the resolution of the existing X-ray diagnostic techniques. Conclusions: X-ray phase contrast imaging can be performed with synchrotron radiation source and has some advantages over the conventional absorption contrast imaging. (authors)

Dose fractionation in synchrotron radiation x-ray phase micro-tomography

International Nuclear Information System (INIS)

Frachon, Thibaut; Weber, Loriane; Hesse, Bernhard; Rit, Simon; Dong, Pei; Olivier, Cecile; Peyrin, Françoise; Langer, Max

2015-01-01

Phase sensitive x-ray imaging expands the applicability of standard attenuation based techniques by offering several orders of magnitude of increase in sensitivity. Due to the short wavelength, x-ray phase is not directly measurable, but has to be put in evidence by the use of phase contrast techniques. The phase can then be reconstructed from one or several phase contrast images. In this study, we consider synchrotron x-ray phase micro-computed tomography (μCT) based on free space propagation for heterogeneous and strongly absorbing objects. This technique generally relies on acquiring several scans of the sample at different detector distances. It is also generally believed that multi-distance phase μCT needs a higher dose input than single distance phase μCT. The purpose of this work is to study the impact of different means of dose fractionation on the reconstructed image quality. We define different acquistion schemes in multi-distance in-line phase μCT. Previously, the exposure time at each sample-to-detector distance was usually kept the same. Here, we let not only the number of distances vary but also the fraction of exposure time at each distance, the total exposure time being kept constant. Phase retrieval is performed with the mixed approach algorithm. The reconstructed μCT images are compared in terms of accuracy, precision and resolution. In addition, we also compare the result of dose fractionated multi distance phase μCT to single distance phase μCT using the same total radiation dose. In the multi-distance approach, we find that using different exposure times on each distance improves the image quality in the reconstructed image. Further, we show that, despite having the same total dose delivery, the multi distance imaging method gives better image quality than the single distance method, at the cost of an additional overhead from camera displacements and reference images. We show that by optimizing the acquistion parameters in terms of

Development of a single-phase thermosiphon for cold collection and storage of radiative cooling

Energy Technology Data Exchange (ETDEWEB)

Zhao, Dongliang; Martini, Christine Elizabeth; Jiang, Siyu; Ma, Yaoguang; Zhai, Yao; Tan, Gang; Yin, Xiaobo; Yang, Ronggui

2017-11-01

A single-phase thermosiphon is developed for cold collection and storage of radiative cooling. Compared to the conventional nocturnal radiative cooling systems that use an electric pump to drive the heat transfer fluid, the proposed single-phase thermosiphon uses the buoyancy force to drive heat transfer fluid. This solution does not require electricity, therefore improving the net gain of the radiative cooling system. A single-phase thermosiphon was built, which consists of a flat panel, a cold collection tank, a water return tube, and a water distribution tank. Considering that outdoor radiative cooling flux is constantly changing (i.e. uncontrollable), an indoor testing facility was developed to provide a controllable cooling flux (comparable to a radiative cooling flux of 100 W/m2) for the evaluation of thermosiphon performance. The testing apparatus is a chilled aluminum flat plate that has a controlled air gap separation relative to the flat panel surface of the thermosiphon to emulate radiative cooling. With an average of 105 W/m2 cooling flux, the 18 liters of water in the thermosiphon was cooled to an average temperature of 12.5 degrees C from an initial temperature of 22.2 degrees C in 2 h, with a cold collection efficiency of 96.8%. The results obtained have demonstrated the feasibility of using a single-phase thermosiphon for cold collection and storage of radiative cooling. Additionally, the effects of the thermosiphon operation conditions, such as tilt angle of the flat panel, initial water temperature, and cooling energy flux, on the performance have been experimentally investigated. Modular design of the single-phase thermosiphon gives flexibility for its scalability. A radiative cooling system with multiple thermosiphon modules is expected to play an important role in cooling buildings and power plant condensers.

Manipulating Liquids With Acoustic Radiation Pressure Phased Arrays

Science.gov (United States)

Oeftering, Richard C.

1999-01-01

High-intensity ultrasound waves can produce the effects of "Acoustic Radiation Pressure" (ARP) and "acoustic streaming." These effects can be used to propel liquid flows and to apply forces that can be used to move or manipulate floating objects or liquid surfaces. NASA's interest in ARP includes the remote-control agitation of liquids and the manipulation of bubbles and drops in liquid experiments and propellant systems. A high level of flexibility is attained by using a high-power acoustic phased array to generate, steer, and focus a beam of acoustic waves. This is called an Acoustic Radiation Pressure Phased Array, or ARPPA. In this approach, many acoustic transducer elements emit wavelets that converge into a single beam of sound waves. Electronically coordinating the timing, or "phase shift," of the acoustic waves makes it possible to form a beam with a predefined direction and focus. Therefore, a user can direct the ARP force at almost any desired point within a liquid volume. ARPPA lets experimenters manipulate objects anywhere in a test volume. This flexibility allow it to be used for multiple purposes, such as to agitate liquids, deploy and manipulate drops or bubbles, and even suppress sloshing in spacecraft propellant tanks.

On intermittent flow characteristics of gas–liquid two-phase flow

Energy Technology Data Exchange (ETDEWEB)

Thaker, Jignesh; Banerjee, Jyotirmay, E-mail: jbaner@gmail.com

2016-12-15

Highlights: • Unified correlations for intermittent flow characteristics are developed. • Influence of inflow conditions on intermittent flow characteristics is analysed. • Developed correlations can be used for effective design of piping components. - Abstract: Flow visualisation experiments are reported for intermittent regime of gas–liquid two-phase flow. Intermittent flow characteristics, which include plug/slug frequency, liquid plug/slug velocity, liquid plug/slug length, and plug/slug bubble length are determined by image processing of flow patterns captured at a rate of 1600 frames per second (FPS). Flow characteristics are established as a function of inlet superficial velocity of both the phases (in terms of Re{sub SL} and Re{sub SG}). The experimental results are first validated with the existing correlations for slug flow available in literature. It is observed that the correlations proposed in literature for slug flow do not accurately predict the flow characteristics in the plug flow regime. The differences are clearly highlighted in this paper. Based on the measured database for both plug and slug flow regime, modified correlations for the intermittent flow regime are proposed. The correlations reported in the present paper, which also include plug flow characteristics will aid immensely to the effective design and optimization of operating conditions for safer operation of two-phase flow piping systems.

Non-ionizing radiations : physical characteristics, biological effects and health hazard assessment

International Nuclear Information System (INIS)

Repacholi, M.H.

1988-01-01

The Workshop was a project of the International Non-Ionizing Radiation Committee of IRPA and comprised a series of educational lectures and demonstrations intended to give a comprehensive overview of non-ionizing electromagnetic radiation: physical characteristics, sources of concern, levels of exposure, mechanisms of interaction and reported effects of these fields and radiations with biological tissues, human studies, health risk assessment, national and international standards and guidelines, and protective measures

Anomalous phase change characteristics in Fe-Te materials

International Nuclear Information System (INIS)

Fu, X. T.; Song, W. D.; Ji, R.; Ho, H. W.; Wang, L.; Hong, M. H.

2012-01-01

Phase change materials have become significantly attractive due to its unique characteristics for its extensive applications. In this paper, a kind of phase change material, which consists of Fe and Te components, is developed. The crystallization temperature of the Fe-Te materials is 180 deg. C for Fe 1.19 Te and can be adjusted by the Fe/Te ratio. High-speed phase change in the Fe-Te materials has been demonstrated by nanosecond laser irradiation. Comparing to conventional phase change materials, the Fe-Te materials exhibit an anomalous optical property that has higher reflectivity at amorphous than crystalline state, which is useful for data storage design.

Simulation of Thermal, Neutronic and Radiation Characteristics in Spent Nuclear Fuel and Radwaste Facilities

International Nuclear Information System (INIS)

Poskas, P.; Bartkus, G.

1999-01-01

The overview of the activities in the Division of Thermo hydro-mechanics related with the assessment of thermal, neutronic and radiation characteristics in spent nuclear fuel and radwaste facilities are performed. Also some new data about radiation characteristics of the RBMK-1500 spent nuclear fuel are presented. (author)

Evaluation of gamma radiation effects on stationary phases using gas chromatografy

International Nuclear Information System (INIS)

Basso, M.A.; Collins, K.E.; Collins, C.H.

1988-01-01

The overall objetive of this project is a thorough study of the effect of gamma radiation on supported stationary phases used in packed-column gas chromatography. The phases studied were SP-2100 on Supelcoport and SE-30 on Chromsorb W. The fases were irradiated with cobalt-60 gamma rays to various doses and subsequently subjected to tests of extractability, termal stability and efficiency as a chromatographic column packing. Extraction tests indicate that low doses of radiation are sufficient to produce significant immobilization of these polymethylsilicones; that is, to produce chemical bonds between different polymer chains or between the stationary phase and the support. Thermal stability is also increased. The values calculated for the number of theoretical plates (n) and resolution (Rsub (s)) after analysis of four synthetic mixtures of organic compounds also increase, in most cases, indicating that the gamma irradiation has positively altered the behavior of these stationary phases. (author) [pt

Phases and phase transition in insoluble and adsorbed monolayers of amide amphiphiles: Specific characteristics of the condensed phases.

Science.gov (United States)

Vollhardt, D

2015-08-01

For understanding the role of amide containing amphiphiles in inherently complex biological processes, monolayers at the air-water interface are used as simple biomimetic model systems. The specific characteristics of the condensed phases and phase transition in insoluble and adsorbed monolayers of amide amphiphiles are surveyed to highlight the effect of the chemical structure of the amide amphiphiles on the interfacial interactions in model monolayers. The mesoscopic topography and/or two-dimensional lattice structures of selected amino acid amphiphiles, amphiphilic N-alkylaldonamide, amide amphiphiles with specific tailored headgroups, such as amide amphiphiles based on derivatized ethanolamine, e.g. acylethanolamines (NAEs) and N-,O-diacylethanolamines (DAEs) are presented. Special attention is devoted the dominance of N,O-diacylated ethanolamine in mixed amphiphilic acid amide monolayers. The evidence that a first order phase transition can occur in adsorption layers and that condensed phase domains of mesoscopic scale can be formed in adsorption layers was first obtained on the basis of the experimental characteristics of a tailored amide amphiphile. New thermodynamic and kinetic concepts for the theoretical description of the characteristics of amide amphiphile's monolayers were developed. In particular, the equation of state for Langmuir monolayers generalized for the case that one, two or more phase transitions occur, and the new theory for phase transition in adsorbed monolayers are experimentally confirmed at first by amide amphiphile monolayers. Despite the significant progress made towards the understanding the model systems, these model studies are still limited to transfer the gained knowledge to biological systems where the fundamental physical principles are operative in the same way. The study of biomimetic systems, as described in this review, is only a first step in this direction. Copyright © 2014 Elsevier B.V. All rights reserved.

Generation of phase-locked and tunable continuous-wave radiation in the terahertz regime.

Science.gov (United States)

Quraishi, Qudsia; Griebel, Martin; Kleine-Ostmann, Thomas; Bratschitsch, Rudolf

2005-12-01

Broadly tunable phase-stable single-frequency terahertz radiation is generated with an optical heterodyne photomixer. The photomixer is excited by two near-infrared CW diode lasers that are phase locked to the stabilized optical frequency comb of a femtosecond titanium:sapphire laser. The terahertz radiation emitted by the photomixer is downconverted into RF frequencies with a waveguide harmonic mixer and measurement-limited linewidths at the Hertz level are demonstrated.

Initial studies of synchrotron radiation phase-contrast imaging in the field of medicine

International Nuclear Information System (INIS)

Chen Shaoliang; Zhang Xi; Peng Yifeng; Li Beilei; Cheng Aiping; Zhu Peiping; Yuan Xiqing; Huang Wanxia

2010-01-01

Recently,research on using X-ray phase information in medicine has been growing remarkably fast. Phase-contrast imaging with synchrotron radiation can reveal inner soft tissues such as tendons, cartilage, ligaments, adipose tissue, vessels and nerves without a contrast agent. We have visualized the liver, bile duct, lung, kidney, stomach and intestine, heart, blood vessel, bone and arthrosis, and tumor tissues using 'in-line' phase contrast imaging and diffraction-enhanced imaging. It is seen that the synchrotron radiation graphs show much higher resolution. This method is especially suitable for studying soft tissue structure and blood vessels. (authors)

OBSERVATIONAL SIGNATURES OF SUB-PHOTOSPHERIC RADIATION-MEDIATED SHOCKS IN THE PROMPT PHASE OF GAMMA-RAY BURSTS

International Nuclear Information System (INIS)

Levinson, Amir

2012-01-01

A shock that forms below the photosphere of a gamma-ray burst (GRB) outflow is mediated by Compton scattering of radiation advected into the shock by the upstream fluid. The characteristic scale of such a shock, a few Thomson depths, is larger than any kinetic scale involved by several orders of magnitude. Hence, unlike collisionless shocks, radiation-mediated shocks cannot accelerate particles to nonthermal energies. The spectrum emitted by a shock that emerges from the photosphere of a GRB jet reflects the temperature profile downstream of the shock, with a possible contribution at the highest energies from the shock transition layer itself. We study the properties of radiation-mediated shocks that form during the prompt phase of GRBs and compute the time-integrated spectrum emitted by the shocked fluid following shock breakout. We show that the time-integrated emission from a single shock exhibits a prominent thermal peak, with the location of the peak depending on the shock velocity profile. We also point out that multiple shock emission can produce a spectrum that mimics a Band spectrum.

G2 phase arrest of cell cycle induced by ionizing radiation

International Nuclear Information System (INIS)

Liu Guangwei; Gong Shouliang

2002-01-01

The exposure of mammalian cells to X rays results in the prolongation of the cell cycle, including the delay or the arrest in G 1 , S and G 2 phase. The major function of G 1 arrest may be to eliminate the cells containing DNA damage and only occurs in the cells with wild type p53 function whereas G 2 arrest following ionizing radiation has been shown to be important in protecting the cells from death and occurs in all cells regardless of p53 status. So the study on G 2 phase arrest of the cell cycle induced by ionizing radiation has currently become a focus at radiobiological fields

A K/Ka band radiating element for Tx/Rx phased array

KAUST Repository

Sandhu, Ali Imran; Arnieri, E.; Amendola, G.; Boccia, L.; Meniconi, E.; Ziegler, V.

2017-01-01

The paper presents a K/Ka band radiating element for TX/RX phased arrays. Dual band operations is obtained using a single radiating surface: a novel radiator is adopted and placed in a configuration in which dual band and single band elements are interleaved. The array elements are optimized to scan the beam in excess of 50° in both bands. A subarray with 49 Rx elements and 105 Tx elements was built and measured confirming the results obtained in simulations.

A K/Ka band radiating element for Tx/Rx phased array

KAUST Repository

Sandhu, Ali Imran

2017-01-20

The paper presents a K/Ka band radiating element for TX/RX phased arrays. Dual band operations is obtained using a single radiating surface: a novel radiator is adopted and placed in a configuration in which dual band and single band elements are interleaved. The array elements are optimized to scan the beam in excess of 50° in both bands. A subarray with 49 Rx elements and 105 Tx elements was built and measured confirming the results obtained in simulations.

Titanium Loop Heat Pipes for Space Nuclear Radiators, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project will develop titanium Loop Heat Pipes (LHPs) that can be used in low-mass space nuclear radiators, such as...

Chaotic characteristic of electromagnetic radiation time series of coal or rock under different scales

Energy Technology Data Exchange (ETDEWEB)

Zhen-Tang Liu; En-Lai Zhao; En-Yuan Wang; Jing Wang [China University of Mining and Technology, Xuzhou (China). School of Safety Engineering

2009-02-15

Based on chaos theory, the chaotic characteristics of electromagnetic radiation time series of coal or rock under different loads was studied. The results show that the correlation of electromagnetic radiation time series of small-scale coal or rock and coal mine converges to a stable saturation value, which shows that these electromagnetic radiation time series have chaos characteristics. When there is danger of coal seam burst, the value of the saturation correlation dimension D{sub 2} of the electromagnetic radiation time series is bigger and it changes greatly; when there is no danger, its value is smaller and changes smoothly. The change of saturation correlation of electromagnetic radiation time series can be used to forecast coal or rock dynamic disasters. 11 refs., 4 figs.

Characteristics of the new phase in CDT

Energy Technology Data Exchange (ETDEWEB)

Ambjoern, J. [Copenhagen University, The Niels Bohr Institute, Copenhagen Oe (Denmark); Radboud University, Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), Nijmegen (Netherlands); Gizbert-Studnicki, J.; Jurkiewicz, J. [Jagiellonian University, Institute of Physics, Krakow (Poland); Goerlich, A. [Copenhagen University, The Niels Bohr Institute, Copenhagen Oe (Denmark); Jagiellonian University, Institute of Physics, Krakow (Poland); Klitgaard, N.; Loll, R. [Radboud University, Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), Nijmegen (Netherlands)

2017-03-15

The approach of Causal Dynamical Triangulations (CDT), a candidate theory of nonperturbative quantum gravity in 4D, turns out to have a rich phase structure. We investigate the recently discovered bifurcation phase C{sub b} and relate some of its characteristics to the presence of singular vertices of very high order. The transition lines separating this phase from the ''time-collapsed'' B-phase and the de Sitter phase C{sub dS} are of great interest when searching for physical scaling limits. The work presented here sheds light on the mechanisms behind these transitions. First, we study how the B-C{sub b} transition signal depends on the volume fixing implemented in the simulations, and find results compatible with the previously determined second-order character of the transition. The transition persists in a transfer matrix formulation, where the system's time extension is taken to be minimal. Second, we relate the new C{sub b}-C{sub dS} transition to the appearance of singular vertices, which leads to a direct physical interpretation in terms of a breaking of the homogeneity and isotropy observed in the de Sitter phase when crossing from C{sub dS} to the bifurcation phase C{sub b}. (orig.)

Effect of ionizing radiations on some organoleptic characteristics of edible mushroom

International Nuclear Information System (INIS)

Kovacs, E.; Vas, K.

1974-01-01

Organoleptic characteristics - colour, odour, flavour and texture - of edible mushrooms (Agaricus bisporus) in different stages of ripeness (half-ripe, ripe) were examined as a function of radiation dose, storage time as well as storage temperature, and humidity (3-5 0 C, 70-90% RH; 16 0 C, 65-75% RH). Immediately after irradiation the mushrooms assumed a slight brownish hue which, however, did not change on further storage. The brown discoloration of untreated mushroom progressed in the course of storage. The colour of the irradiated mushroom scarcely changed with storage time, tested on the 6th, 11th or 13th day. Other properties examined (odour, flavour, texture) were not affected by irradiation, either immediately upon treatment or during further storage. Ionizing radiation was found to exert favourable influence upon the organoleptic properties of picked mushrooms, and to delay the deterioration of these properties. Radiation treatment was found to preserve the characteristic mushroom odour and this is considered an advantage in canning. (F.J.)

Two-phase flow characteristics analysis code: MINCS

International Nuclear Information System (INIS)

Watanabe, Tadashi; Hirano, Masashi; Akimoto, Masayuki; Tanabe, Fumiya; Kohsaka, Atsuo.

1992-03-01

Two-phase flow characteristics analysis code: MINCS (Modularized and INtegrated Code System) has been developed to provide a computational tool for analyzing two-phase flow phenomena in one-dimensional ducts. In MINCS, nine types of two-phase flow models-from a basic two-fluid nonequilibrium (2V2T) model to a simple homogeneous equilibrium (1V1T) model-can be used under the same numerical solution method. The numerical technique is based on the implicit finite difference method to enhance the numerical stability. The code structure is highly modularized, so that new constitutive relations and correlations can be easily implemented into the code and hence evaluated. A flow pattern can be fixed regardless of flow conditions, and state equations or steam tables can be selected. It is, therefore, easy to calculate physical or numerical benchmark problems. (author)

Radiation-induced trioxane postpolymerization in the liquid phase

International Nuclear Information System (INIS)

Kapustina, I.B.; Starchenko, T.V.

1979-01-01

Radiation-induced trioxane postpolymerization in the presence of maleic anhydride and different solvents in the liquid phase has been studied. It has been found that addition of small quantities of different solvents inhibits the trioxane polymerization process both in the presence of maleic anhydride and in the absence of it. Trioxane postpolymerization in a solvent-nonsolvent mixture gives fibrous polyoxymethylene with high molecular mass and high yield

Radiation-stimulated phase in titanium dihydride TiH1.95

International Nuclear Information System (INIS)

Khidirov, I.; Mukhtarova, N.N.; Baktibaev, K.O.; Getmanskiy, V.V.

2001-01-01

In titanium dihydride TiH 1.95 γ-irradiation has been shown by X-ray and neutron-diffraction methods to stimulate the phase transition FCC→VCT at doses ≥3·10 10 R and irradiation temperature ≅100 d eg C. The space group of the formed phase is D 4h 17 -14/mmm, its lattice parameters a m =0.3161 nm, c m =0.4418 nm are related to parameters of the initial (FCC) phase by relations a m ≅a k /2 1/2 , c m ≅a k . It was established that the phase obtained is metastable, it relaxes at the temperatures ≥37 d eg C and transforms into the stable FCC phase that corresponds to the equilibrium phase diagram of Ti-H system. The temperature of the phase transition increases by influence of γ-quanta, the radiation-stimulated phase differs from thermostimulated one by a larger unit cell and a smaller degree of tetragonal distortion. (author)

Study on the immunity state of mouse exposed to mobile phone radiation during embryonic phase

International Nuclear Information System (INIS)

Pei Yinhui; Gao Hui

2008-01-01

Objective: To study the effect of mobile phone radiation on mouse which exposed to radiation during embryonic phase. Methods: Pregnant mice were exposed to mobile phone radiation. The mice's netrophile phage percentage and spleen lymphocyte transformation rate were detected respectively 2 months after birth. Results: The netrophile phage percentage of experimental mice was seemly the same as that of control group, and there was no significant difference (P>0.05), but the spleen transformation rate showed the diverse trend. Conclusion: The specific cellular immunity of mice, which ex- posed to mobile phone radiation during embryonic phase, was seen to be in a state of decreasement. (authors)

Research on Radiation Characteristic of Plasma Antenna through FDTD Method

Directory of Open Access Journals (Sweden)

Jianming Zhou

2014-01-01

Full Text Available The radiation characteristic of plasma antenna is investigated by using the finite-difference time-domain (FDTD approach in this paper. Through using FDTD method, we study the propagation of electromagnetic wave in free space in stretched coordinate. And the iterative equations of Maxwell equation are derived. In order to validate the correctness of this method, we simulate the process of electromagnetic wave propagating in free space. Results show that electromagnetic wave spreads out around the signal source and can be absorbed by the perfectly matched layer (PML. Otherwise, we study the propagation of electromagnetic wave in plasma by using the Boltzmann-Maxwell theory. In order to verify this theory, the whole process of electromagnetic wave propagating in plasma under one-dimension case is simulated. Results show that Boltzmann-Maxwell theory can be used to explain the phenomenon of electromagnetic wave propagating in plasma. Finally, the two-dimensional simulation model of plasma antenna is established under the cylindrical coordinate. And the near-field and far-field radiation pattern of plasma antenna are obtained. The experiments show that the variation of electron density can introduce the change of radiation characteristic.

Research on radiation characteristic of plasma antenna through FDTD method.

Science.gov (United States)

Zhou, Jianming; Fang, Jingjing; Lu, Qiuyuan; Liu, Fan

2014-01-01

The radiation characteristic of plasma antenna is investigated by using the finite-difference time-domain (FDTD) approach in this paper. Through using FDTD method, we study the propagation of electromagnetic wave in free space in stretched coordinate. And the iterative equations of Maxwell equation are derived. In order to validate the correctness of this method, we simulate the process of electromagnetic wave propagating in free space. Results show that electromagnetic wave spreads out around the signal source and can be absorbed by the perfectly matched layer (PML). Otherwise, we study the propagation of electromagnetic wave in plasma by using the Boltzmann-Maxwell theory. In order to verify this theory, the whole process of electromagnetic wave propagating in plasma under one-dimension case is simulated. Results show that Boltzmann-Maxwell theory can be used to explain the phenomenon of electromagnetic wave propagating in plasma. Finally, the two-dimensional simulation model of plasma antenna is established under the cylindrical coordinate. And the near-field and far-field radiation pattern of plasma antenna are obtained. The experiments show that the variation of electron density can introduce the change of radiation characteristic.

Radiation heredity: unusual structural-phase states and metallic crystals properties

International Nuclear Information System (INIS)

Melikhov, V.D.; Skakov, M.K.

1998-01-01

Some experimental results allowing to judge about possibilities of unusual structural phase states formation during use irradiation and high temperature treatment of metallic crystals are considered. During study of pure (99.99 %) and especially pure (99.999 %) aluminium it was established, that after heating of preliminary irradiated samples in reactor, and non-irradiated ones up to temperatures above melting point (660 deg C), but not higher than 820 deg C, and cooling an microstructure and substructure of both irradiated and non-irradiated metals have been essentially distinguished with each other. If first of them had typically polycrystal construction, that second one was monocrystal with good developed initial substructure. Radiation effects have been preserved even in liquid metal if it was not overheated higher critical point, which is determined by phase transition from quasi-liquid state to true liquid one. During study of irradiation and postradiation treatment of structure and properties of intermetallides Fe 3 Al it was revealed, that in initially irradiated regulated alloys the radiation effect is preserving at heating of above 0.85 T melt (that essentially exceed order-disorder transition temperature) (550 deg C) in non-irradiated alloys of prolonged exposure and hardening. At that, irradiated-hardened alloy distinguishing from not hardened one by lattice parameter (on 0.1 %), by configuration of nearest surrounding of iron atoms in elementary cell, by regulating extent of different kind of atoms in lattice knocks. It was revealed, that at fluence (5·10 24 n·m 2 ) an appearance of new phases, distinguishing from matrix by component content. It was shown, that irradiation and post-radiation treatment are methods for creation unusual structural-phase states and attach to metals and alloys new properties

Phase behavior and radiation effects in high level waste class

International Nuclear Information System (INIS)

Turcotte, R.P.; Roberts, F.P.

1977-02-01

Results are presented that demonstrate that detailed and reproducible data can be obtained for complex waste glasses. For the major glass composition examined, thermal treatment was shown to cause formation of several crystalline phases which contribute to an increased leachability. Although not discussed in detail here, Zn 2 SiO 4 formation results in microcracking due to a thermal expansion mismatch with the glass matrix, and SrMoO 4 has a higher leachability than the glass matrix. The temperature dependence describing equilibrium concentrations of these two phases and a qualitative understanding of ingrowth kinetics have been established, hence conditions necessary to eliminate their formation during processing and early storage, are known. Radiation damage effects, when extrapolated to long times, suggest energy storage of approximately 50 cal/gram and either positive or negative density changes occur (depending on the glass composition) in the 1 percent range. No radiation damage-related changes of serious concern have been found for homogeneous glasses by 244 Cm doping experiments now approaching a simulated damage time of approximately 10 3 years (for UO 2 fuel wastes). More work is needed concerning heterogeneous damage which will occur in devitrified glasses. As a final point, the complications with respect to understanding behavior of polyphase systems with respect to either radiation damage or leaching behavior, are self evident. Homogeneous glasses with improved leach resistance, and thermal and radiation stability are clear objectives for future glass development

Radiation-acoustic system for solid state research

International Nuclear Information System (INIS)

Zalyubovsky, I.I.; Kalinichenko, A.I.; Kresnin, Yu.; Popov, G.F.

1998-01-01

The radiation-acoustic system (RAS) is designed for comprehensive investigation of thermoelastic (TE), thermophysical (TP) and thermodynamic (TD) characteristics of structural materials. It operation is based on radiation-acoustic method, which includes probing of investigated materials by pulsed electron beam and registration the exited thermo acoustic stress. The hardware includes a CAMAC crate, an IBM PC computer, a set of sensors, a strobe analog-digital converter, a commutators of analog signals, and drivers of physical parameters. The system allows to process thermo acoustic signals generated in beam-target interaction and to extract information about phase state, TE-, TP-, and TD characteristics of the target materials. The system was used for simultaneous measuring of phase state, TE-, TP-, and TD characteristics and for investigation of kinetics of structural phase transitions in multifunctional materials such as materials with the shape memory effect (CuAlNi, TiNi, TiNiFe, TiNiCu), rare-earth metals (Dy, Gd), high-temperature superconductors YBaCuO, piezoelectric crystals (TiBa, ZrTiPb-ceramics), polymers (PMMA, PTFE, PE) etc

The improvement for fire retardant and radiation resistance characteristics of chloroprene rubber

Energy Technology Data Exchange (ETDEWEB)

Kim, K. Y.; Lee, C.; Kim, P. J.; Kim, J. H

2004-04-01

In the report, in order to improve the fire retardancy better Chloroprene Rubber (CR) after adding each fixed amount of inorganic metallic hydroxide, and then compared and assessed fire retardancy with electrical properties and mechanical properties we intended to choose the most excellent additives. Also according to Co{sup 60} {gamma}-ray irradiation, we compared electrical, echanical and fire retardant characteristics to analyse to have the additives of inorganic filler effect on CR's antirad characteristic. In result, CR containing inorganic additive, advanced considerably fire retardant characteristics, but seems to be tended to declined electrical and mechanical characteristics on the whole. In syntherically comparison, the specimen viewed the most excellent characteristics is CR containing Magnesium hydroxide. As to Co{sup 60} {gamma}-ray irradiated Chloroprene rubber containing inorganic additives, fire retardant characteristic are improved, but electrical and mechanical properties are deteriorated as a function of radiation dose. Comparing before irradiation and after irradiation, the best inorganic filler into CR consider Magnesium hydroxide. In this report, in case of adding 30 phr of inorganic filler to CR we observed fire retardancy and radiation resistance characteristics change in according to the kinds of additives, but the research for choosing the optimum amount of additives is considered to progress from now on as adjusting the amount of additives presented excellent characteristics.

Spectral Cauchy characteristic extraction of strain, news and gravitational radiation flux

International Nuclear Information System (INIS)

Handmer, Casey J; Szilágyi, Béla; Winicour, Jeffrey

2016-01-01

We present a new approach for the Cauchy-characteristic extraction (CCE) of gravitational radiation strain, news function, and the flux of the energy–momentum, supermomentum and angular momentum associated with the Bondi–Metzner–Sachs asymptotic symmetries. In CCE, a characteristic evolution code takes numerical data on an inner worldtube supplied by a Cauchy evolution code, and propagates it outwards to obtain the space–time metric in a neighborhood of null infinity. The metric is first determined in a scrambled form in terms of coordinates determined by the Cauchy formalism. In prior treatments, the waveform is first extracted from this metric and then transformed into an asymptotic inertial coordinate system. This procedure provides the physically proper description of the waveform and the radiated energy but it does not generalize to determine the flux of angular momentum or supermomentum. Here we formulate and implement a new approach which transforms the full metric into an asymptotic inertial frame and provides a uniform treatment of all the radiation fluxes associated with the asymptotic symmetries. Computations are performed and calibrated using the spectral Einstein code. (paper)

Theoretical analysis on radiation and reception characteristics of an oblate spheroidal antenna for electron plasma waves

International Nuclear Information System (INIS)

Ohnuki, S.; Adachi, S.; Ohnuma, T.

1978-01-01

The radiation and reception characteristics of the oblate spheroidal antenna for electron plasma waves are theoretically investigated. The analysis is carried out as a boundary-value problem. The formulas for the radiation and reception characteristics such as radiation impedance, electron charge distributions, radiated wave potential, directional properties, and receiving voltage of the oblate spheroidal antenna are analytically obtained. As a result, it is concluded that the radiation and reception characteristics of the antennas are not uniquely determined by k/sub p/a (k/sub p/ is the wave number of an electron plasma wave, and a is the radius of the circular-plate antenna), but are determined by two out of three factors, k/sub p/a, zeta (radius divided by Debye length), and ω/ω/sub p/ (angular signal frequency to angular plasma frequency). This conclusion is in marked contrast to the conventional theory in which the charge distribution on the antenna is assumed a priori as uniform and, thus, the antenna characteristics are uniquely determined by k/sub p/a. It is claimed that the experimental results obtained hitherto support the present new theory

Removal of radiation damage by subpopulations of plateau-phase Chinese hamster ovary cells

International Nuclear Information System (INIS)

Nelson, J.M.; Metting, N.F.; Braby, L.A.; Roesch, W.C.

1987-01-01

Specific cellular radiobiology studies are often required to test aspects of the mathematical models developed in the Radiation Dosimetry program. These studies are designed to determine whether specific mathematical expressions, which characterize the expected effect of biochemical mechanisms on observable biological responses, are consistent with the behavior of selected cell lines. Since these tests place stringent requirements on the cellular system, special techniques and culture conditions are required to minimize biological variability. The use of specialized cell populations is providing data on the extent of repair following low doses, and on the changes in the types of damage that can be repaired as the cell progresses toward mitosis. The stationary-phase Chinese hamster ovary (CHO) cells are composed primarily of G(1)-phase cells (83%), with the remainder comprising both G(2) and S phases. Removal of radiation damage by cells was studied in split-dose experiments. To date, we have observed no significant differences in cellular repair rate. This suggests, therefore, that each of the repair processes found in stationary-phase cells is cell-age independent. However, cellular radiation sensitivity does change rapidly and considerably as the cells progress from one phase to the next through the cell cycle. Since the rate of damage removal appears invariant, the change in survival must reflect the efficiency of producing that damage. The experimental data suggest that production of one or another sort of damage probably dominates during specific phases of the cell cycle, while the capacity for removal of all types of damage remains relatively constant

SIMULATION OF CHARACTERISTICS OF DUAL-CORE PHASE SHIFTING TRANSFORMER

Directory of Open Access Journals (Sweden)

Kalinin L.P.

2014-04-01

Full Text Available The role and importance of phase shifting transformers are increased as a result of the further development of integrated power systems. This gives the rise to new technical solutions which entails the necessity of comparison of new developments with existing. The article consider the technical characteristics of dual-core phase shifting transformer which later will be used as a basis for comparison with other competing options and assess of their technical efficiency.

An equivalent ground thermal test method for single-phase fluid loop space radiator

Directory of Open Access Journals (Sweden)

Xianwen Ning

2015-02-01

Full Text Available Thermal vacuum test is widely used for the ground validation of spacecraft thermal control system. However, the conduction and convection can be simulated in normal ground pressure environment completely. By the employment of pumped fluid loops’ thermal control technology on spacecraft, conduction and convection become the main heat transfer behavior between radiator and inside cabin. As long as the heat transfer behavior between radiator and outer space can be equivalently simulated in normal pressure, the thermal vacuum test can be substituted by the normal ground pressure thermal test. In this paper, an equivalent normal pressure thermal test method for the spacecraft single-phase fluid loop radiator is proposed. The heat radiation between radiator and outer space has been equivalently simulated by combination of a group of refrigerators and thermal electrical cooler (TEC array. By adjusting the heat rejection of each device, the relationship between heat flux and surface temperature of the radiator can be maintained. To verify this method, a validating system has been built up and the experiments have been carried out. The results indicate that the proposed equivalent ground thermal test method can simulate the heat rejection performance of radiator correctly and the temperature error between in-orbit theory value and experiment result of the radiator is less than 0.5 °C, except for the equipment startup period. This provides a potential method for the thermal test of space systems especially for extra-large spacecraft which employs single-phase fluid loop radiator as thermal control approach.

Calculating the radiation characteristics of accelerated electrons in laser-plasma interactions

International Nuclear Information System (INIS)

Li, X. F.; Yu, Q.; Qu, J. F.; Kong, Q.; Gu, Y. J.; Ma, Y. Y.; Kawata, S.

2016-01-01

In this paper, we studied the characteristics of radiation emitted by electrons accelerated in a laser–plasma interaction by using the Lienard–Wiechert field. In the interaction of a laser pulse with a underdense plasma, electrons are accelerated by two mechanisms: direct laser acceleration (DLA) and laser wakefield acceleration (LWFA). At the beginning of the process, the DLA electrons emit most of the radiation, and the DLA electrons emit a much higher peak photon energy than the LWFA electrons. As the laser–plasma interaction progresses, the LWFA electrons become the major radiation emitter; however, even at this stage, the contribution from DLA electrons is significant, especially to the peak photon energy.

Radiation and thermal characteristics of mouse lymphoma cells and their radiation-sensitive mutant

International Nuclear Information System (INIS)

Baba, Yuji; Yasunaga, Tadamasa; Uozumi, Hideaki; Takahashi, Mutsumasa; Sawada, Shozo.

1988-01-01

Radiation and thermal characteristics of L5178Y cells and their radiation-sensitive mutant M10 cells were studied by the colony-forming method and the dye-exclusion method using eosin-Y. Although M10 cells were remarkably radiation-sensitive compared with L5178Y cells, it was diffcult to cause interphase death of M10 after a large dose of irradiation. After heat treatments, L5178Y cells revealed more cell destruction and were stained well by eosin-Y, but it was relatively difficult to produce cell destruction of M10 cells, which showed poor staining by eosin-Y. When assayed by the colony-forming method, M10 cells were also heat-resistant compared to L5178Y. The dye-exclusion rate was closely correlated with cell survival after hyperthermia of L5178Y cells, suggesting that this is a simple method of detecting the thermosensitivity and thermotolerance of cancer cells. The difference in survival of L5178Y cells and M10 cells after combined treatment with gamma irradiation and hyperthermia was smaller than with gamma irradiation alone. It was also found that there was a relationship between radiation-induced interphase death and hyperthermia-induced interphase death, and that interphase death accounted for a major part of cell death caused by hyperthermia in mouse leukemia cells. (author)

Gamma radiation influence on technological characteristics of wheat flour

International Nuclear Information System (INIS)

Teixeira, Christian A.H.M.; Inamura, Patricia Y.; Uehara, Vanessa B.; Mastro, Nelida L.d.

2012-01-01

This study aimed at determining the influence of gamma radiation on technological characteristics of wheat (Triticum sativum) flour and physical properties of pan breads made with this flour. The bread formulation included wheat flour, water, milk, salt, sugar, yeast and butter. The α-amylase activity of wheat flour irradiated with 1, 3 and 9 kGy in a Gammacell 220 (AECL), one day, five days and one month after irradiation was evaluated. Deformation force, height and weight of breads prepared with the irradiated flour were also determined. The enzymatic activity increased—reduction of falling number time—as radiation dose increased, their values being 397 s (0 kGy), 388 s (1 kGy), 343 s (3 kGy) and 293 s (9 kGy) respectively, remaining almost constant over the period of one month. Pan breads prepared with irradiated wheat flour showed increased weight. Texture analysis showed that bread made of irradiated flour presented an increase in maximum deformation force. The results indicate that wheat flour ionizing radiation processing may confer increased enzymatic activity on bread making and depending on the irradiation dose, an increase in weight, height and deformation force parameters of pan breads made of it. - Highlights: ► We study the influence of gamma radiation on wheat flour and properties of breads. ► Falling number decreased with radiation remaining almost constant up to one month. ► Ionizing radiation may confer an increase in texture parameters, weight and height on the bread.

Preliminary study on radiation crosslinking of PE-NBR multiple phase system

International Nuclear Information System (INIS)

Wang Hong; Zhang Wanxi; Sun Jiazhen

1989-01-01

The effect of radiation crosslinking on the structure and properties of PE-NBR (polyethylene-acrylonitrile-butadiene rubber) multiple phase system was studied in this paper. The relationship of sol fraction and irradiated dose to multiplephase system was demonstrated

Radiation-hardened optically reconfigurable gate array exploiting holographic memory characteristics

Science.gov (United States)

Seto, Daisaku; Watanabe, Minoru

2015-09-01

In this paper, we present a proposal for a radiation-hardened optically reconfigurable gate array (ORGA). The ORGA is a type of field programmable gate array (FPGA). The ORGA configuration can be executed by the exploitation of holographic memory characteristics even if 20% of the configuration data are damaged. Moreover, the optoelectronic technology enables the high-speed reconfiguration of the programmable gate array. Such a high-speed reconfiguration can increase the radiation tolerance of its programmable gate array to 9.3 × 104 times higher than that of current FPGAs. Through experimentation, this study clarified the configuration dependability using the impulse-noise emulation and high-speed configuration capabilities of the ORGA with corrupt configuration contexts. Moreover, the radiation tolerance of the programmable gate array was confirmed theoretically through probabilistic calculation.

Some new characteristics of the strengthening phase in β-phase magnesium-lithium alloys containing aluminum and beryllium

International Nuclear Information System (INIS)

Song Guangsheng; Staiger, Mark; Kral, Milo

2004-01-01

Hardness, optical-microscopy and X-ray diffraction studies on the strengthening phase in β-phase magnesium-lithium alloys containing different content of aluminum were carried out to give some new characteristics of the strengthening phase affecting lattice distortion and α-Mg precipitation in the β-matrix. In the presence of the strengthening-phase precipitates, the matrix lattice undergoes substantial strain characterized by peak broadening. The peak width in the β-matrix phase pattern can provide an indication of lattice strain caused by the strengthening-phase precipitates. The origin of α-Mg precipitation resulting from the decomposition of the strengthening phase into stable AlLi compound is also explained in the present work

Structural-electrical coupling optimisation for radiating and scattering performances of active phased array antenna

Science.gov (United States)

Wang, Congsi; Wang, Yan; Wang, Zhihai; Wang, Meng; Yuan, Shuai; Wang, Weifeng

2018-04-01

It is well known that calculating and reducing of radar cross section (RCS) of the active phased array antenna (APAA) are both difficult and complicated. It remains unresolved to balance the performance of the radiating and scattering when the RCS is reduced. Therefore, this paper develops a structure and scattering array factor coupling model of APAA based on the phase errors of radiated elements generated by structural distortion and installation error of the array. To obtain the optimal radiating and scattering performance, an integrated optimisation model is built to optimise the installation height of all the radiated elements in normal direction of the array, in which the particle swarm optimisation method is adopted and the gain loss and scattering array factor are selected as the fitness function. The simulation indicates that the proposed coupling model and integrated optimisation method can effectively decrease the RCS and that the necessary radiating performance can be simultaneously guaranteed, which demonstrate an important application value in engineering design and structural evaluation of APAA.

Brightness and coherence of synchrotron radiation and high-gain free electron lasers

International Nuclear Information System (INIS)

Kim, K.J.

1986-10-01

The characteristics of synchrotron radiation are reviewed with particular attention to its phase-space properties and coherence. The transition of the simple undulator radiation to more intense, more coherent high-gain free electron lasers, is discussed

Study on electromagnetic radiation and mechanical characteristics of coal during an SHPB test

Science.gov (United States)

Chengwu, Li; Qifei, Wang; Pingyang, Lyu

2016-06-01

Dynamic loads provided by a Split Hopkinson pressure bar are applied in the impact failure experiment on coal with an impact velocity of 4.174-17.652 m s-1. The mechanical property characteristics of coal and an electromagnetic radiation signal can be detected and measured during the experiment. The variation of coal stress, strain, incident energy, dissipated energy and other mechanical parameters are analyzed by the unidimensional stress wave theory. It suggests that with an increase of the impact velocity, the mechanical parameters and electromagnetic radiation increased significantly and the dissipated energy of the coal sample has a high discrete growing trend during the failure process of coal impact. Combined with the received energy of the electromagnetic radiation signal, the relationship between these mechanical parameters and electromagnetic radiation during the failure process of coal burst could be analyzed by the grey correlation model. The results show that the descending order of the gray correlation degree between the mechanical characteristics and electromagnetic radiation energy are impact velocity, maximum stress, the average stress, incident energy, the average strain, maximum strain, the average strain rate and dissipation energy. Due to the correlation degree, the impact velocity and incident energy are relatively large, and the main factor affecting the electromagnetic radiation energy of coal is the energy magnitude. While the relationship between extreme stress and the radiation energy change trend is closed, the stress state of coal has a greater impact on electromagnetic radiation than the strain and destruction which can deepen the research of the coal-rock dynamic disaster electromagnetic monitoring technique.

Elementary analysis of massive samples at excitation of characteristic x-radiation by proton beams

International Nuclear Information System (INIS)

Altynov, V.A.; Blokhin, S.M.; Brazevich, Eh.; Brazevich, Ya.; Lyu Zaj Ik; Osetinskij, G.M.; Purehv, A.

1982-01-01

A simplified method is described for calculating the elementary composition in the massive samples in the case of the detection of the characteristic X-radiation emitted under the bombardment of the samples by a beam of protons. The method was experimentally verified by measuring the characteristic X-radiation from the elements with a known concentration entering the one-component and multi-component matrix. It was shown that within the experimental accuracy the discussed method gave results analogous to those obtained with the earlier used methods

Radiation Characteristics of the Cavity Backed Antenna in Conducting Cone

Institute of Scientific and Technical Information of China (English)

无

2002-01-01

A technique using finite element and boundary integral method (FE-BI) and reciprocity theorem is presented to analyze the radiation characteristics of cavity backed antenna mounted on a conducting cone. The electric fields inside the cavity and on the aperture are obtained using finite element and boundary integral method. The far-field characteristic of the antenna is computed using reciprocity theorem. The paper begins with a general description of the method. An application of this method is given and the numerical result is compared with the experimental result.

Optimization of 64-MDCT urography: effect of dual-phase imaging with furosemide on collecting system opacification and radiation dose.

Science.gov (United States)

Portnoy, Orith; Guranda, Larisa; Apter, Sara; Eiss, David; Amitai, Marianne Michal; Konen, Eli

2011-11-01

The purpose of this study was to compare opacification of the urinary collecting system and radiation dose associated with three-phase 64-MDCT urographic protocols and those associated with a split-bolus dual-phase protocol including furosemide. Images from 150 CT urographic examinations performed with three scanning protocols were retrospectively evaluated. Group A consisted of 50 sequentially registered patients who underwent a three-phase protocol with saline infusion. Group B consisted of 50 sequentially registered patients who underwent a reduced-radiation three-phase protocol with saline. Group C consisted of 50 sequentially registered patients who underwent a dual-phase split-bolus protocol that included a low-dose furosemide injection. Opacification of the urinary collecting system was evaluated with segmental binary scoring. Contrast artifacts were evaluated, and radiation doses were recorded. Results were compared by analysis of variance. A significant reduction in mean effective radiation dose was found between groups A and B (p < 0.001) and between groups B and C (p < 0.001), resulting in 65% reduction between groups A and C (p < 0.001). This reduction did not significantly affect opacification score in any of the 12 urinary segments (p = 0.079). In addition, dense contrast artifacts overlying the renal parenchyma observed with the three-phase protocols (groups A and B) were avoided with the dual-phase protocol (group C) (p < 0.001). A dual-phase protocol with furosemide injection is the preferable technique for CT urography. In comparison with commonly used three-phase protocols, the dual-phase protocol significantly reduces radiation exposure dose without reduction in image quality.

Approximate characteristics for one-dimensional two-phase flows

International Nuclear Information System (INIS)

Sarayloo, A.; Peddleson, J.

1985-01-01

An approximate method for determining the characteristics associated with one-dimensional particulate two-phase flow models is presented. The method is based on iteration and is valid for small particulate volume fractions. The method is applied to several special cases involving incompressible particles suspended in a gas. The influences of certain changes in the physical model are investigated

Heat transfer characteristics of building walls using phase change material

Science.gov (United States)

Irsyad, M.; Pasek, A. D.; Indartono, Y. S.; Pratomo, A. W.

2017-03-01

Minimizing energy consumption in air conditioning system can be done with reducing the cooling load in a room. Heat from solar radiation which passes through the wall increases the cooling load. Utilization of phase change material on walls is expected to decrease the heat rate by storing energy when the phase change process takes place. The stored energy is released when the ambient temperature is low. Temperature differences at noon and evening can be utilized as discharging and charging cycles. This study examines the characteristics of heat transfer in walls using phase change material (PCM) in the form of encapsulation and using the sleeve as well. Heat transfer of bricks containing encapsulated PCM, tested the storage and released the heat on the walls of the building models were evaluated in this study. Experiments of heat transfer on brick consist of time that is needed for heat transfer and thermal conductivity test as well. Experiments were conducted on a wall coated by PCM which was exposed on a day and night cycle to analyze the heat storage and heat release. PCM used in these experiments was coconut oil. The measured parameter is the temperature at some points in the brick, walls and ambient temperature as well. The results showed that the use of encapsulation on an empty brick can increase the time for thermal heat transfer. Thermal conductivity values of a brick containing encapsulated PCM was lower than hollow bricks, where each value was 1.3 W/m.K and 1.6 W/m.K. While the process of heat absorption takes place from 7:00 am to 06:00 pm, and the release of heat runs from 10:00 pm to 7:00 am. The use of this PCM layer can reduce the surface temperature of the walls of an average of 2°C and slows the heat into the room.

Radiation resistance characteristics of optical communication system for single mode

International Nuclear Information System (INIS)

Ohe, Masamoto; Chigusa, Yoshiki; Kyodo, Tomohisa; Tanaka, Gohtaro; Watanabe, Hajime; Okamoto, Shin-ichi; Yamamoto, Takao.

1988-01-01

Optical communication has been utilized also for nuclear power stations and fuel reporocessing plants. As the sufficient safety countermeasures are required there, the amount of information becomes enormous, therefore, optical communication, by which the required space is expected to be reduced, becomes more important. Also in the application to submarine cables, attention must be paid to the radiation resistance as there are the effects of potassium contained in large amount in seawater and uranium deposits in sea bottom. Therefore, the reliability of the components of optical communication systems against radiation becomes a problem. In this study, single mode optical fibers and transmission and receipt modules were selected, and high dose rate irradiation supposing the case of using in a cell and low dose rate, long time irradiation supposing the case of submarine cables were carried out to evaluate the radiation resistance characteristics. The fibers tested were SiO 2 core/F-SiO 2 clad type and GeO 2 -SiO 2 core/SiO 2 clad type. The characteristics of increasing loss in irradiation and restoration after irradiation of the former type were superior to those of the latter type. The output of a receipt module was normal during irradiation, and the output power of a transmission module decreases, but other problems did not arise. (K.I.)

Characteristics of low-mass-velocity vertical gas-liquid two-phase flow

International Nuclear Information System (INIS)

Adachi, Hiromichi; Abe, Yutaka; Kimura, Ko-ji

1995-01-01

In the present paper, characteristics of low mass velocity two-phase flow was analyzed based on a concept that pressure energy of two-phase flow is converted into acceleration work, gravitational work and frictional work, and the pressure energy consumption rate should be minimum at the stable two-phase flow condition. Experimental data for vertical upward air-water two-phase flow at atmospheric pressure was used to verify this concept and the turbulent model used in this method is optimized with the data. (author)

Fatigue characteristics of dual-phase steel sheets

Energy Technology Data Exchange (ETDEWEB)

Onn, Irwan Herman; Ahmad, Norhayati; Tamin, Mohd Nasir [Universiti Teknologi Malaysia, Skudai (Malaysia)

2015-01-15

Fatigue characteristics of dual-phase steel sheets, commonly used in automobile body construction were established. For this purpose, a series of fatigue tests, each at constant stress amplitude were conducted on 1.2 mm-thick, dual-phase DP600 steel sheet specimens with two different load ratios of minimum-to-maximum stress, R = 0.1 and -1. The resulting fatigue behavior is expressed in terms of fatigue strength-life (S-N) curves. Fatigue behavior of the steel sheets in the high-cycle fatigue region can be represented by Basquin's equation with coefficient and exponent value of 921.2 and 0.093, respectively. An endurance limit of 255 MPa is observed. In addition, fatigue strengths of the dual-phase steel sheets display lower magnitude than their bulk counterparts. Effect of mean stress on fatigue behavior of the steel sheets is well predicted by Walker's model. Exponential calibration factor is introduced to the models by SWT, Goodman and Morrow with comparable prediction to the Walker's model.

Radiation Characteristics Enhancement of Dielectric Resonator Antenna Using Solid/Discrete Dielectric Lenses

Directory of Open Access Journals (Sweden)

H. A. E. Malhat

2015-02-01

Full Text Available The radiation characteristics of the dielectric resonator antennas (DRA is enhanced using different types of solid and discrete dielectric lenses. One of these approaches is by loading the DRA with planar superstrate, spherical lens, or by discrete lens (transmitarray. The dimensions and dielectric constant of each lens are optimized to maximize the gain of the DRA. A comparison between the radiations characteristics of the DRA loaded with different lenses are introduced. The design of the dielectric transmitarray depends on optimizing the heights of the dielectric material of the unit cell. The optimized transmitarray achieves 7 dBi extra gain over the single DRA with preserving the circular polarization. The proposed antenna is suitable for various applications that need high gain and focused antenna beam.

Phase control effects in optical diffraction radiation from a slit

International Nuclear Information System (INIS)

Castellano, M.; Chiadroni, E.; Cianchi, A.

2010-01-01

Optical Diffraction Radiation (ODR) from a slit is becoming a real promising instrument for measuring the transverse beam size, or even the emittance of the very high brightness linacs driving SASE FELs or the future ILC which require non-intercepting diagnostic devices. But to correctly explain experimental data it is necessary to further develop the theory of this radiation emission. In this paper we discuss in particular the effects of a non-perfect coplanarity of the two halves of a slit, that introduces a phase difference in the field produced by the two half-planes. Such non-coplanarity can result from mechanical stress for instance.

Effect of insulin phase state in water on its radiation stability

Energy Technology Data Exchange (ETDEWEB)

Soboleva, N N; Ivanova, A I; Tal' roze, V L; Trofimov, V I; Fedotov, V P [Nauchno-Issledovatel' skij Inst. po Biologicheskim Ispytaniyam Khimicheskikh Soedinenij (USSR); AN SSSR, Moscow. Inst. Khimicheskoj Fiziki; Akademiya Meditsinskikh Nauk SSSR, Moscow. Inst. Ehksperimental' noj Ehndokrinologii i Khimii Gormonov)

1980-01-01

Radiation stability of the aqueous solution and the insulin suspension is investigated. The degree of radiation transformations is determined by means of chromatography on paper and with the method of cramp reaction in mice. ..gamma..-irradiation is carried out at room temperature, at dose rate of 0.75 M rad/h. The data obtained prove the earlier suggested hypothesis of a phase division of a biologically active compound, personally medicinal substance and water (for example, in the case of which permits to prolong the preservation of medicine in the case of irradiation.

High purity liquid phase epitaxial gallium arsenide nuclear radiation detector

International Nuclear Information System (INIS)

Alexiev, D.; Butcher, K.S.A.

1991-11-01

Surface barrier radiation detector made from high purity liquid phase epitaxial gallium arsenide wafers have been operated as X- and γ-ray detectors at various operating temperatures. Low energy isotopes are resolved including 241 Am at 40 deg C. and the higher gamma energies of 235 U at -80 deg C. 15 refs., 1 tab., 6 figs

A RADIATION TRANSFER SOLVER FOR ATHENA USING SHORT CHARACTERISTICS

International Nuclear Information System (INIS)

Davis, Shane W.; Stone, James M.; Jiang Yanfei

2012-01-01

We describe the implementation of a module for the Athena magnetohydrodynamics (MHD) code that solves the time-independent, multi-frequency radiative transfer (RT) equation on multidimensional Cartesian simulation domains, including scattering and non-local thermodynamic equilibrium (LTE) effects. The module is based on well known and well tested algorithms developed for modeling stellar atmospheres, including the method of short characteristics to solve the RT equation, accelerated Lambda iteration to handle scattering and non-LTE effects, and parallelization via domain decomposition. The module serves several purposes: it can be used to generate spectra and images, to compute a variable Eddington tensor (VET) for full radiation MHD simulations, and to calculate the heating and cooling source terms in the MHD equations in flows where radiation pressure is small compared with gas pressure. For the latter case, the module is combined with the standard MHD integrators using operator splitting: we describe this approach in detail, including a new constraint on the time step for stability due to radiation diffusion modes. Implementation of the VET method for radiation pressure dominated flows is described in a companion paper. We present results from a suite of test problems for both the RT solver itself and for dynamical problems that include radiative heating and cooling. These tests demonstrate that the radiative transfer solution is accurate and confirm that the operator split method is stable, convergent, and efficient for problems of interest. We demonstrate there is no need to adopt ad hoc assumptions of questionable accuracy to solve RT problems in concert with MHD: the computational cost for our general-purpose module for simple (e.g., LTE gray) problems can be comparable to or less than a single time step of Athena's MHD integrators, and only few times more expensive than that for more general (non-LTE) problems.

Fractal characteristics correlation between the solar total radiation and net radiation on the apple tree canopy

International Nuclear Information System (INIS)

Meng Ping; Zhang Jingsong

2005-01-01

The characteristics correlation between solar total radiations(Q) and net radiation(R n) on the apple tree canopy at mainly growth stage in the hilly of Taihang Mountain are analyzed with fractal theory based on regression analysis. The results showed that:1)Q and R n had good liner correlation. The regression function was as the following:R n=0.740 8Q-32.436, which coefficient r is 0.981 1(n=26 279), F cal= 343 665.2 F 0.01 36 277=6.63; 2)The fractal dimension curves of Q and R n both had two no s caling regions, which circumscription time value of the inflexion was 453 and 441 minutes respectively.In the first region, fractal dimensions of Q and R n was 1.112 6, 1.131 9 respectively,and 1.913 6@@@ 1.883 4 in the second region.Those information showed that fractal characteristics of Q and R n is similar. So R n can be calculated with Q on the apple tree canopy

Standard guide for evaluating performance characteristics of phased-Array ultrasonic testing instruments and systems

CERN Document Server

American Society for Testing and Materials. Philadelphia

2008-01-01

1.1 This guide describes procedures for evaluating some performance characteristics of phased-array ultrasonic examination instruments and systems. 1.2 Evaluation of these characteristics is intended to be used for comparing instruments and systems or, by periodic repetition, for detecting long-term changes in the characteristics of a given instrument or system that may be indicative of impending failure, and which, if beyond certain limits, will require corrective maintenance. Instrument characteristics measured in accordance with this guide are expressed in terms that relate to their potential usefulness for ultrasonic examinations. Other electronic instrument characteristics in phased-array units are similar to non-phased-array units and may be measured as described in E 1065 or E 1324. 1.3 Ultrasonic examination systems using pulsed-wave trains and A-scan presentation (rf or video) may be evaluated. 1.4 This guide establishes no performance limits for examination systems; if such acceptance criteria ar...

Radiative characteristics of CVL pumped dye laser

Energy Technology Data Exchange (ETDEWEB)

Kubo, Uichi; Ishiguro, Takahide

1987-09-01

This paper describes the radiative characteristics of CVL pumped dye laser. It is compared YAG-SH (530 nm) with CVL (511, 578 nm) and CVL (511 nm) for pumping source. Influence of solvent in dye laser power was examined. The present experimental results show that efficiency of CVL (511 nm) pumped dye laser was most high. When the dye solution is at a standstill, the efficiency of dye laser with water and Sodium Lauryl Sulfate (S.L.S., 2 %wt.) was most high among the four kinds of solvent. In the condition of dye solution flow, the water and S.L.S. or ethylene glycol was useful solvent for dye laser.

Radiation characteristics and effective optical properties of dumbbell-shaped cyanobacterium Synechocystis sp

International Nuclear Information System (INIS)

Heng, Ri-Liang; Pilon, Laurent

2016-01-01

This study presents experimental measurements of the radiation characteristics of unicellular freshwater cyanobacterium Synechocystis sp. during their exponential growth in F medium. Their scattering phase function at 633 nm average spectral absorption and scattering cross-sections between 400 and 750 nm were measured. In addition, an inverse method was used for retrieving the spectral effective complex index of refraction of overlapping or touching bispheres and quadspheres from their absorption and scattering cross-sections. The inverse method combines a genetic algorithm and a forward model based on Lorenz–Mie theory, treating bispheres and quadspheres as projected area and volume-equivalent coated spheres. The inverse method was successfully validated with numerically predicted average absorption and scattering cross-sections of suspensions consisting of bispheres and quadspheres, with realistic size distributions, using the T-matrix method. It was able to retrieve the monomers' complex index of refraction with size parameter up to 11, relative refraction index less than 1.3, and absorption index less than 0.1. Then, the inverse method was applied to retrieve the effective spectral complex index of refraction of Synechocystis sp. approximated as randomly oriented aggregates consisting of two overlapping homogeneous spheres. Both the measured absorption cross-section and the retrieved absorption index featured peaks at 435 and 676 nm corresponding to chlorophyll a, a peak at 625 nm corresponding to phycocyanin, and a shoulder around 485 nm corresponding to carotenoids. These results can be used to optimize and control light transfer in photobioreactors. The inverse method and the equivalent coated sphere model could be applied to other optically soft particles of similar morphologies. - Highlights: • Radiation characteristics of Synechocystis sp. were measured during exponential growth. • This unicellular freshwater cyanobacterium features an interesting

Relationship of scattering phase shifts to special radiation force conditions for spheres in axisymmetric wave-fields.

Science.gov (United States)

Marston, Philip L; Zhang, Likun

2017-05-01

When investigating the radiation forces on spheres in complicated wave-fields, the interpretation of analytical results can be simplified by retaining the s-function notation and associated phase shifts imported into acoustics from quantum scattering theory. For situations in which dissipation is negligible, as taken to be the case in the present investigation, there is an additional simplification in that partial-wave phase shifts become real numbers that vanish when the partial-wave index becomes large and when the wave-number-sphere-radius product vanishes. By restricting attention to monopole and dipole phase shifts, transitions in the axial radiation force for axisymmetric wave-fields are found to be related to wave-field parameters for traveling and standing Bessel wave-fields by considering the ratio of the phase shifts. For traveling waves, the special force conditions concern negative forces while for standing waves, the special force conditions concern vanishing radiation forces. An intermediate step involves considering the functional dependence on phase shifts. An appendix gives an approximation for zero-force plane standing wave conditions. Connections with early investigations of acoustic levitation are mentioned and some complications associated with viscosity are briefly noted.

The effect of ionizing radiation on analog characteristics of MOSFET

International Nuclear Information System (INIS)

Ren Diyuan; Yu Xuefeng; Lu Wu; Gao Wenyu; Fan Long; Zhang Guoqiang; Yan Rongliang

1994-01-01

The effects of 60 Co γ-ray on the linearity and output characteristics of MOSFETs were investigated. The relations of oxide-trapped charge and Si/SiO 2 interface state density to the decrease of mobility μ-bar and transconductance g m , and the shift of the output curves for both P-MOSFETs and N-MOSFETs were qualitatively described. It was shown that degradation of analog characteristics, for P-MOSFETs, resulted from both oxide-trapped charge and interface state, but the degradation for N-MOSFETs was mainly due to the increase of radiation induced Si-SiO 2 interface state density

Soft X-ray radiation power characteristics of tungsten wire arrays on Yang accelerator

International Nuclear Information System (INIS)

Zhang Siqun; Ouyang Kai; Huang Xianbin; Dan Jiakun; Zhou Rongguo; Yang Liang

2013-01-01

A series of experiments were carried out to research the X-ray radiation characteristics of tungsten wire arrays on Yang accelerator. In those experiments, we charged the Marx generator of 60 kV, and the load current of 0.85-1.00 MA, the rise time of 75-90 ns (10%-90%). A soft X-ray scintillator powermeter which responded flatly to 50-1800 eV X-rays was used to measure the power of soft X-ray emitted from implosion plasma. In this paper, we present the measuring results of time-resolved soft X-ray radiation power, and discuss the radiation characteristics of implosion plasma by analyzing the correlations of soft X-ray radiant power and the diameter, length, wire number of the tungsten wire arrays. The optimizing wire array configuration parameters on Yang are as follows: 8 mm array diameter, 15 mm wire length, and 24 wire number. We also present the radiant power difference in radial and axial directions of the wire arrays. (authors)

Study of the radiated energy loss during massive gas injection mitigated disruptions on EAST

Science.gov (United States)

Duan, Y. M.; Hao, Z. K.; Hu, L. Q.; Wang, L.; Xu, P.; Xu, L. Q.; Zhuang, H. D.; EAST Team

2015-08-01

The MGI mitigated disruption experiments were carried out on EAST with a new fast gas controlling valve in 2012. Different amounts of noble gas He or mixed gas of 99% He + 1% Ar are injected into plasma in current flat-top phase and current ramp-down phase separately. The initial results of MGI experiments are described. The MGI system and the radiation measurement system are briefly introduced. The characteristics of radiation distribution and radiation energy loss are analyzed. About 50% of the stored thermal energy Wdia is dissipated by radiation during the entire disruption process and the impurities of C and Li from the PFC play important roles to radiative energy loss. The amount of the gas can affect the pre-TQ phase. Strong poloidal asymmetry of radiation begins to appear in the CQ phase, which is possibly caused by the plasma configuration changes as a result of VDE. No toroidal radiation asymmetry is observed presently.

Inhibition of G1-phase arrest induced by ionizing radiation in hematopoietic cells by overexpression of genes involved in the G1/S-phase transition

International Nuclear Information System (INIS)

Epperly, M.; Berry, L.; Halloran, A.; Greenberger, J.S.

1995-01-01

D-type cyclins and cyclin-dependent kinase (cdk-4) are likely involved in regulating passage of cells through the G 1 phase of the cell cycle. A decrease in the proportion of cells in G 1 , a relatively radiation-sensitive phase of the cell cycle, should result in increased resistance to ionizing radiation; however, the effect of such overexpression on X-ray-induced G 1 -phase arrest is not known. Radiation survival curves were obtained at a dose rate of either 8 cGy/min or 1 Gy/min for subclones of the IL-3-dependent hematopoietic progenitor cell line 32D cl 3 expressing transgenes for either cyclin-D1, D2 or D3 or cdk-4. We compared the results to those with overexpression of the transgene for Bcl-2, whose expression enhances radiation survival and delays apoptosis. Cells overexpressing transgenes for each D-type cyclin or Bcl-2 had an increased number of cells in S phase compared to parent line 32D cl 3; however, overexpression of cdk-4 had no effect on cell cycle distribution. Cell death resulting from withdrawal of IL-3 was not affected by overexpression of D2, cdk-4 or Bcl-2. Flow cytometry 24 h after 5 Gy irradiation demonstrated that overexpression of each G 1 -phase regulatory transgene decreased the proportion of cells at the G 1 /S-phase border. Western analysis revealed induction of cyclin-D protein levels by irradiation, but no change in the D O , but a significant increase in the rvec n for cyclin-D or cdk-4 transgene-overexpressing clones at 1 Gy/min (P 1 /S-phase arrest. 31 refs., 4 figs., 4 tabs

A Local Condensation Analysis Representing Two-phase Annular Flow in Condenser/radiator Capillary Tubes

Science.gov (United States)

Karimi, Amir

1991-01-01

NASA's effort for the thermal environmental control of the Space Station Freedom is directed towards the design, analysis, and development of an Active Thermal Control System (ATCS). A two phase, flow through condenser/radiator concept was baselined, as a part of the ATCS, for the radiation of space station thermal load into space. The proposed condenser rejects heat through direct condensation of ATCS working fluid (ammonia) in the small diameter radiator tubes. Analysis of the condensation process and design of condenser tubes are based on the available two phase flow models for the prediction of flow regimes, heat transfer, and pressure drops. The prediction formulas use the existing empirical relationships of friction factor at gas-liquid interface. An attempt is made to study the stability of interfacial waves in two phase annular flow. The formulation is presented of a stability problem in cylindrical coordinates. The contribution of fluid viscosity, surface tension, and transverse radius of curvature to the interfacial surface is included. A solution is obtained for Kelvin-Helmholtz instability problem which can be used to determine the critical and most dangerous wavelengths for interfacial waves.

Theoretical investigation on radiation tolerance of {{\\boldsymbol{M}}}_{{\\boldsymbol{n}}+1}{{\\boldsymbol{AX}}}_{{\\boldsymbol{n}}} phases

Science.gov (United States)

Yin, Ke-Di; Zhang, Xi-Tong; Huang, Qing; Xue, Jian-Ming

2017-06-01

Ternary {M}n+1{{AX}}n phases with layered hexagonal structures, as candidate materials used for next-generation nuclear reactors, have shown great potential in tolerating radiation damage due to their unique combination of ceramic and metallic properties. However, {M}n+1{{AX}}n materials behave differently in amorphization when exposed to energetic neutron and ion irradiations in experiment. We first analyze the irradiation tolerances of different {M}n+1{{AX}}n (MAX) phases in terms of electronic structure, including the density of states (DOS) and charge density map. Then a new method based on the Bader analysis with the first-principle calculation is used to estimate the stabilities of MAX phases under irradiation. Our calculations show that the substitution of Cr/V/Ta/Nb by Ti and Si/Ge/Ga by Al can increase the ionicities of the bonds, thus strengthening the radiation tolerance. It is also shown that there is no obvious difference in radiation tolerance between {M}n+1A{{{C}}}n and {M}n+1A{{{N}}}n due to the similar charge transfer values of C and N atoms. In addition, the improved radiation tolerance from Ti3AlC2 to Ti2AlC (Ti3AlC2 and Ti2AlC have the same chemical elements), can be understood in terms of the increased Al/TiC layer ratio. Criteria based on the quantified charge transfer can be further used to explore other {M}n+1{{AX}}n phases with respect to their radiation tolerance, playing a critical role in choosing appropriate MAX phases before they are subjected to irradiation in experimental test for future nuclear reactors. Project supported by the National Natural Science Foundation of China (Grant Nos. 91226202 and 91426304).

Advanced Nongray Radiation Module in the LOCI Framework for Combustion CFD, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Radiative heat fluxes are important in the design of launch vehicles for Project Constellation. In this Phase II STTR, CFDRC and its partner Mississippi State...

Radiative characteristics of CVL pumped dye laser

International Nuclear Information System (INIS)

Kubo, Uichi; Ishiguro, Takahide.

1987-01-01

This paper describes the radiative characteristics of CVL pumped dye laser. It is compared YAG-SH (530 nm) with CVL (511, 578 nm) and CVL (511 nm) for pumping source. Influence of solvent in dye laser power was examined. The present experimental results show that efficiency of CVL (511 nm) pumped dye laser was most high. When the dye solution is at a standstill, the efficiency of dye laser with water and Sodium Lauryl Sulfate (S.L.S., 2 %wt.) was most high among the four kinds of solvent. In the condition of dye solution flow, the water and S.L.S. or Ethylene Glycol was useful solvent for dye laser. (author)

Phase Contrast Imaging

International Nuclear Information System (INIS)

Menk, Ralf Hendrik

2008-01-01

All standard (medical) x-ray imaging technologies, rely primarily on the amplitude properties of the incident radiation, and do not depend on its phase. This is unchanged since the discovery by Roentgen that the intensity of an x-ray beam, as measured by the exposure on a film, was related to the relative transmission properties of an object. However, recently various imaging techniques have emerged which depend on the phase of the x-rays as well as the amplitude. Phase becomes important when the beam is coherent and the imaging system is sensitive to interference phenomena. Significant new advances have been made in coherent optic theory and techniques, which now promise phase information in medical imaging. The development of perfect crystal optics and the increasing availability of synchrotron radiation facilities have contributed to a significant increase in the application of phase based imaging in materials and life sciences. Unique source characteristics such as high intensity, monochromaticity, coherence and high collimating provide an ideal source for advanced imaging. Phase contrast imaging has been applied in both projection and computed tomography modes, and recent applications have been made in the field of medical imaging. Due to the underlying principle of X-ray detection conventional image receptors register only intensities of wave fields and not their phases. During the last decade basically five different methods were developed that translate the phase information into intensity variations. These methods are based on measuring the phase shift φ directly (using interference phenomena), the gradient ∇ φ , or the Laplacian ∇ 2 φ. All three methods can be applied to polychromatic X-ray sources keeping in mind that the native source is synchrotron radiation, featuring monochromatic and reasonable coherent X-ray beams. Due to the vast difference in the coefficients that are driven absorption and phase effects (factor 1,000-10,000 in the energy

Gamma radiation influence on technological characteristics of wheat flour

Science.gov (United States)

Teixeira, Christian A. H. M.; Inamura, Patricia Y.; Uehara, Vanessa B.; Mastro, Nelida L. d.

2012-08-01

This study aimed at determining the influence of gamma radiation on technological characteristics of wheat (Triticum sativum) flour and physical properties of pan breads made with this flour. The bread formulation included wheat flour, water, milk, salt, sugar, yeast and butter. The α-amylase activity of wheat flour irradiated with 1, 3 and 9 kGy in a Gammacell 220 (AECL), one day, five days and one month after irradiation was evaluated. Deformation force, height and weight of breads prepared with the irradiated flour were also determined. The enzymatic activity increased—reduction of falling number time—as radiation dose increased, their values being 397 s (0 kGy), 388 s (1 kGy), 343 s (3 kGy) and 293 s (9 kGy) respectively, remaining almost constant over the period of one month. Pan breads prepared with irradiated wheat flour showed increased weight. Texture analysis showed that bread made of irradiated flour presented an increase in maximum deformation force. The results indicate that wheat flour ionizing radiation processing may confer increased enzymatic activity on bread making and depending on the irradiation dose, an increase in weight, height and deformation force parameters of pan breads made of it.

Prospects for coherently driven nuclear radiation by Coulomb excitation

International Nuclear Information System (INIS)

Karamyan, S.A.; Carroll, J.J.

2006-01-01

Possible experiments are discussed in which the Coulomb excitation of nuclear isomers would be followed by sequential energy release. The possibility of the coherent Coulomb excitation of nuclei ensconced in a crystal by channeled relativistic heavy projectiles is considered. The phase shift between neighbor-nuclei excitations can be identical to the photon phase shift for emission in forward direction. Thus, the elementary string of atoms can radiate coherently with emission of characteristic nuclear γ rays and the intensity of the radiation could be increased due to the summation of amplitudes. The Moessbauer conditions should be important for this new type of collective radiation that could be promising in the context of the γ-lasing problem

Proximity effect on patterning characteristics of hole patterns in synchrotron radiation lithography

International Nuclear Information System (INIS)

Somemura, Yoh; Deguchi, Kimiyoshi; Miyoshi, Kazunori

1994-01-01

This paper reports the results of analyzing the proximity effect on the patterning characteristics for plural neighboring hole patterns in synchrotron radiation lithography. Fresnel diffraction simulation was used and pattern replication experiments were performed with pattern pitch, proximity gap, and mask contrast as parameters. Even when the pattern pitch (hole:space) is 1:1, pattern sizes down to 0.2 μm can be replicated with a large dose margin under a large proximity gap condition up to 40 μm, irrespective of the mask contrast. A low-contrast (2.5) mask has an advantage over the conventional-contrast (7) mask in that it allows the use of a larger proximity gap when replicating hole patterns with a size of 0.1-0.2 μm. Moreover, the phase-shifting mask we previously proposed improves the exposure latitude and widens the proximity gap, so that it is possible to use a 20-μm gap to replicate 0.1-μm hole patterns for a pitch of 1:1 and to use a 30-μm gap for a pitch of 1:2. (author)

Liquid phase epitaxy of abrupt junctions in InAs and studies of injection radiative tunneling processes

International Nuclear Information System (INIS)

Bull, D.J.

1977-01-01

The p-n junction in a InAs crystal, by liquid phase epitaxy is obtained. The processes of injection and tunneling radiative recombination by emitted radiation from active region of p-n junction for low injection current are studied. (M.C.K.) [pt

Characteristics of radiated power for various TFTR [Tokamak Fusion Test Reactor] regimes

International Nuclear Information System (INIS)

Bush, C.E.; Schivell, J.; McNeill, D.H.

1988-04-01

Power loss studies were carried out to determine the impurity radiation and energy transport characteristics of various TFTR operation and confinement regimes including L-Mode, detached plasma, co-only neutral beam injection (energetic ion regime), and the enhanced confinement (''supershot'') regime. Combined bolometric, spectroscopic, and infrared photometry measurements provide a picture of impurity behavior and power accounting in TFTR. The purpose of this paper is to make a survey of the various regimes with the aim of determining the radiated power signatures of each. 10 refs., 6 figs., 1 tab

Deformation characteristics of {delta} phase in the delta-processed Inconel 718 alloy

Energy Technology Data Exchange (ETDEWEB)

Zhang, H.Y., E-mail: haiyanzhang@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Zhang, S.H., E-mail: shzhang@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Cheng, M. [Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Li, Z.X. [Beijing Institute of Aeronautica1 Materials, Beijing 100095 (China)

2010-01-15

The hot working characteristics of {delta} phase in the delta-processed Inconel 718 alloy during isothermal compression deformation at temperature of 950 deg. C and strain rate of 0.005 s{sup -1}, were studied by using optical microscope, scanning electron microscope and quantitative X-ray diffraction technique. The results showed that the dissolution of plate-like {delta} phase and the precipitation of spherical {delta} phase particles coexisted during the deformation, and the content of {delta} phase decreased from 7.05 wt.% to 5.14 wt.%. As a result of deformation breakage and dissolution breakage, the plate-like {delta} phase was spheroidized and transferred to spherical {delta} phase particles. In the center with largest strain, the plate-like {delta} phase disappeared and spherical {delta} phase appeared in the interior of grains and grain boundaries.

Association between lunar phase and sleep characteristics.

Science.gov (United States)

Turányi, Csilla Zita; Rónai, Katalin Zsuzsanna; Zoller, Rezső; Véber, Orsolya; Czira, Mária Eszter; Újszászi, Ákos; László, Gergely; Szentkirályi, András; Dunai, Andrea; Lindner, Anett; Szőcs, Julianna Luca; Becze, Ádám; Kelemen, Andrea; Lendvai, Zsófia; Molnar, Miklos Z; Mucsi, István; Novák, Márta

2014-11-01

Popular belief holds that the lunar cycle affects human physiology, behavior, and health, including sleep. To date, only a few and conflicting analyses have been published about the association between lunar phases and sleep. Our aim was to analyze the relationship between lunar phases and sleep characteristics. In this retrospective, cross-sectional analysis, data from 319 patients who had been referred for sleep study were included. Individuals with apnea-hypopnea index ≥ 15/h were excluded. Socio-demographic parameters were recorded. All participants underwent one-night standard polysomnography. Associations between lunar cycle (new moon, full moon and alternate moon) and sleep parameters were examined in unadjusted and adjusted models. Fifty-seven percent of patients were males. Mean age for men was 45 ± 14 years and 51 ± 12 years for women. In total, 224 persons had their sleep study done during alternate moon, 47 during full moon, and 48 during new moon. Full moon was associated with lower sleep efficiency [median (%) (IQR): new moon 82 (18), full moon 74 (19), alternate moon 82 (15); P < 0.001], less deep sleep [median (%) (IQR): new moon 9 (9), full moon 6 (4), alternate moon 11 (9); P < 0.001], and increased REM latency [median (min) (IQR): new moon 98 (74), full moon 137 (152), alternate moon 97 (76); P < 0.001], even after adjustment for several covariables. The results are consistent with a recent report and the widely held belief that sleep characteristics may be associated with the full moon. Copyright © 2014 Elsevier B.V. All rights reserved.

Effect of surface characteristics on diffuse reflection radiation at lambda=0. 40. mu. m

Energy Technology Data Exchange (ETDEWEB)

Takashima, T [Atmospheric Environment Service, Downsview, Ontario (Canada)

1976-08-01

The diffuse radiation in the upward direction at the top and at an internal level of an inhomogeneous atmosphere is computed at lambda=0.40 ..mu..m. The surface is assumed to reflect light in accordance with a hybrid mode of a diffuse and specular reflector. The objective is to estimate the effect of underlying surface characteristics in terms of the diffuse radiation field. By making use of these results, accuracy in monitoring the atmospheric aerosols would be increased for the use of remote sensing satellite techniques. Junge power law (..gamma..*=3) is adopted for the size distribution of aerosols (1963), while the data given by McClatchy et al. (1971) is used for the number density of aerosols with height distribution. It is noted from the computations that the diffuse reflection radiation is affected by the surface characteristics, even if the albedo of the surface is a fixed constant and very small.

Characteristics of the chrome-tanned sheep leather treated by radiation-induced graft of BA

International Nuclear Information System (INIS)

Zhou Dezhong; Deng Yongzhen; Li Ying

1986-01-01

The characteristics of the chrome-tanned sheep leather treated by radiation-induced graft of BA is presented. Using the method of radiation-induced graft of BA instead of the chrome-retanning, the leather has been obviously improved not only in the surface, such as the brightness, fullness, uniformity of the thickness but also in the physical characteristics such as retaining of tensile strength, decreasing of water absorption after being immersed in water for 2h, and 24h, enhancement of tearing strength and stitch tear strength. Although the air permeability and water vapor permeability are a bit worse than the control, however is still in the range of the standard issued by Light Industry Ministry of China

Development of a long-term post-closure radiation monitor: Phase 2, Topical report, March 1994--July 1995

International Nuclear Information System (INIS)

Reed, S.E.

1995-07-01

The long-term monitoring of a hazardous waste site for migration of radionuclides requires installation of radiation sensors at a large number of subsurface locations. The concept under development employs a passive in-ground measurement probe which contains a scintillator coupled to an optical lightguide. The overall goal of the Long-Term Post-Closure Radiation Monitor System (LPRMS) development program is to configure a long-term radiation monitor using commercially available, demonstrated components to the largest extent possible. The development program is planned as a three phase program spanning a total time of 53 months. The problems to be solved during Phase 1 were primarily those associated with selection of the most appropriate components (scintillator, coupling optics, optical fiber, and opto-electronics) to maximize the signal reaching the detectors and thereby minimizing the integration time required to obtain a reliable measure of radiation. Phase 2 (the current Phase) encompassed the fabrication and testing of the prototype LPRMS probe at a contaminated DOE site, the Fernald Environmental Management Project, in southwestern Ohio. Uranium isotopes are the primary contaminants of concern at this site. The single probe and opto-electronic device were used to made measurements in-situ at relatively shallow subsurface depths. The end objective of Phase 2 was the design of a full-scale prototype system which incorporates all the features expected to be necessary on a commercial system, including 50 meter depth of measurement, multiplexing of multiple probes, and remote transmission of data. This full-scale prototype will be fabricated and field tested for 12 months during Phase 3, and a commercial design will be developed based upon the data gathered and experience gained during the entire program

Statistical Modeling of Radiative Transfer and Transient Characteristics for Multilayer Biological Tissue

Directory of Open Access Journals (Sweden)

S. Yu. Makarov

2014-01-01

Full Text Available The Monte-Carlo method [1] already long ago proved itself as a powerful and universal tool for mathematical modelling in various areas of science and engineering. Researchers often choose this method when it is difficult to find a solution by other ways (or impossible at all, e.g. because of sophisticated analytical dependences, area of modelling or boundary conditions. Certainly, this necessarily statistical and flexible method requires significant computation time, but a continuously increasing computation capability makes it more and more attractive for a choice in specific situation.One of the promising areas to use the method of statistical modelling is description of light propagation in the turbid (scattering media. A high motivation for development of this approach is widely used lasers in biomedicine [3]. Besides, owing to its flexibility, the Monte-Carlo method is also of importance in theoretical researches, in particular, to estimate a degree of adequacy of the offered approximation methods for solving a radiative transfer equation [4].It is known that key parameters of turbid media are an absorption coefficient (characterizes absorption probability of a photon per unit of path length and a scattering coefficient (characterizes scattering probability of a photon per unit of path length. The ratio of each of the coefficients to their sum (extinction defines a probability of "death" or "survival" of a photon, respectively, in interaction with lenses. Generally, in the scattering medium there is a non-coherent radiation component, which in turbid media such as biological tissues, already at the insignificant depth becomes prevailing over the coherent one (residual of the incident laser beam [5].The author used the Monte-Carlo method to simulate optical radiation propagation in the multilayer biological tissues with their optical characteristics corresponding to the skin and subcutaneous tissues. Such a biological tissue is the absorbing

Reference neutron radiations. Part 1: Characteristics and methods of production

International Nuclear Information System (INIS)

2001-01-01

ISO 8529 consists of the following parts, under the general title Reference neutron radiations: Part 1: Characteristics and methods of production; Part 2: Calibration fundamentals of radiation protection devices related to the basic quantities characterizing the radiation field; Part 3: Calibration of area and personal dosimeters and determination of response as a function of energy and angle of incidence. This Part 1. of ISO 8529 specifies the reference neutron radiations, in the energy range from thermal up to 20 MeV, for calibrating neutron-measuring devices used for radiation protection purposes and for determining their response as a function of neutron energy. Reference radiations are given for neutron fluence rates of up to 1x10 9 m 2 s-1 , corresponding, at a neutron energy of 1 MeV, to dose-equivalent rates of up to 100 mSv h -1 . This part of ISO 8529 is concerned only with the methods of producing and characterizing the neutron reference radiations. The procedures for applying these radiations for calibrations are described in ISO 8529-2 and ISO 8529-3. The reference radiations specified are the following: neutrons from radionuclide sources, including neutrons from sources in a moderator; neutrons produced by nuclear reactions with charged particles from accelerators; neutrons from reactors. In view of the methods of production and use of them, these reference radiations are divided, for the purposes of this part of ISO 8529, into the following two separate sections. In clause 4, radionuclide neutron sources with wide spectra are specified for the calibration of neutron measuring devices. These sources should be used by laboratories engaged in the routine calibration of neutron-measuring devices, the particular design of which has already been type tested. In clause 5, accelerator-produced monoenergetic neutrons and reactor-produced neutrons with wide or quasi monoenergetic spectra are specified for determining the response of neutron-measuring devices

A new radiative transfer scattering phase function discretisation approach with inherent energy conservation

CSIR Research Space (South Africa)

Roos, TH

2014-06-01

Full Text Available large sphere scattering phase function distributions of interest for packed bed radiative heat transfer: the analytic distribution for a diffusely reflecting sphere (a backscattering test case) and the distribution for a transparent sphere (n = 1...

SAD phasing with in-house cu Ka radiation using barium as anomalous scatterer.

Science.gov (United States)

Dhanasekaran, V; Velmurugan, D

2011-12-01

Phasing of lysozyme crystals using co-crystallized barium ions was performed using single-wavelength anomalous diffraction (SAD) method using Cu Ka radiation with in-house source of data collection. As the ion binding sites vary with respect to the pH of the buffer during crystallization, the highly isomorphic forms of lysozyme crystals grown at acidic and alkaline pH were used for the study. Intrinsic sulphur anomalous signal was also utilized with anomalous signal from lower occupancy ions for phasing. The study showed that to solve the structure by SAD technique, 2.8-fold data redundancy was sufficient when barium was used as an anomalous marker in the in-house copper X-ray radiation source for data collection. Therefore, co-crystallization of proteins with barium containing salt can be a powerful tool for structure determination using lab source.

Combined conduction and radiation with phase change in teflon slabs

International Nuclear Information System (INIS)

Shih, T.M.; Hsu, I.C.; Cunnington, G.R. Jr.

1986-01-01

A new approach to investigate, numerically, an one-dimensional Stefan problem with combined radiation and conduction has been developed. This numerical scheme is a modified version of the heat flux method and the scheme tracks the moving phase changing interface by coordinate transformation. The physical problem involves the radiative heating on one side of a Teflon slab; causing the material to melt and sublime as the melt-solid interface recedes. The other side of the Teflon slab is insulated. The results of this numerical scheme has been compared with results reported in the literature; before attempting to use this scheme to predict the experimental data. Satisfactory agreement between numerical results and the results in the literature as well as the experimental data has been obtained in both comparisons

Radiation characteristics of input power from surface wave sustained plasma antenna

Energy Technology Data Exchange (ETDEWEB)

Naito, T., E-mail: Naito.Teruki@bc.MitsubishiElectric.co.jp [Advanced Technology R& D Center, Mitsubishi Electric Corporation, Amagasaki, Hyogo 661-8661 (Japan); Yamaura, S. [Information Technology R& D Center, Mitsubishi Electric Corporation, Kamakura, Kanagawa 247-8501 (Japan); Fukuma, Y. [Communication System Center, Mitsubishi Electric Corporation, Amagasaki, Hyogo 661-8661 (Japan); Sakai, O. [Department of Electronic System Engineering, The University of Shiga Prefecture, Hikone, Shiga 522-8533 (Japan)

2016-09-15

This paper reports radiation characteristics of input power from a surface wave sustained plasma antenna investigated theoretically and experimentally, especially focusing on the power consumption balance between the plasma generation and the radiation. The plasma antenna is a dielectric tube filled with argon and small amount of mercury, and the structure is a basic quarter wavelength monopole antenna at 2.45 GHz. Microwave power at 2.45 GHz is supplied to the plasma antenna. The input power is partially consumed to sustain the plasma, and the remaining part is radiated as a signal. The relationship between the antenna gain and the input power is obtained by an analytical derivation and numerical simulations. As a result, the antenna gain is kept at low values, and most of the input power is consumed to increase the plasma volume until the tube is filled with the plasma whose electron density is higher than the critical electron density required for sustaining the surface wave. On the other hand, the input power is consumed to increase the electron density after the tube is fully filled with the plasma, and the antenna gain increases with increasing the electron density. The dependence of the antenna gain on the electron density is the same as that of a plasma antenna sustained by a DC glow discharge. These results are confirmed by experimental results of the antenna gain and radiation patterns. The antenna gain of the plasma is a few dB smaller than that of the identical metal antenna. The antenna gain of the plasma antenna is sufficient for the wireless communication, although it is difficult to substitute the plasma antenna for metal antennas completely. The plasma antenna is suitable for applications having high affinity with the plasma characteristics such as low interference and dynamic controllability.

Radiation characteristics of input power from surface wave sustained plasma antenna

International Nuclear Information System (INIS)

Naito, T.; Yamaura, S.; Fukuma, Y.; Sakai, O.

2016-01-01

This paper reports radiation characteristics of input power from a surface wave sustained plasma antenna investigated theoretically and experimentally, especially focusing on the power consumption balance between the plasma generation and the radiation. The plasma antenna is a dielectric tube filled with argon and small amount of mercury, and the structure is a basic quarter wavelength monopole antenna at 2.45 GHz. Microwave power at 2.45 GHz is supplied to the plasma antenna. The input power is partially consumed to sustain the plasma, and the remaining part is radiated as a signal. The relationship between the antenna gain and the input power is obtained by an analytical derivation and numerical simulations. As a result, the antenna gain is kept at low values, and most of the input power is consumed to increase the plasma volume until the tube is filled with the plasma whose electron density is higher than the critical electron density required for sustaining the surface wave. On the other hand, the input power is consumed to increase the electron density after the tube is fully filled with the plasma, and the antenna gain increases with increasing the electron density. The dependence of the antenna gain on the electron density is the same as that of a plasma antenna sustained by a DC glow discharge. These results are confirmed by experimental results of the antenna gain and radiation patterns. The antenna gain of the plasma is a few dB smaller than that of the identical metal antenna. The antenna gain of the plasma antenna is sufficient for the wireless communication, although it is difficult to substitute the plasma antenna for metal antennas completely. The plasma antenna is suitable for applications having high affinity with the plasma characteristics such as low interference and dynamic controllability.

A phase I trial of tocoferol monoglucoside in patients undergoing hemi-body radiation

Directory of Open Access Journals (Sweden)

Huilgol N

2005-01-01

Full Text Available Purpose: To evaluate Tocoferol monoglucoside (TMG, a water soluble vit. E. in a phase I trial, as a radiation protector in those undergoing hemi-body radiation for disseminated disease. Materials and Methods: Patients scheduled to receive modified hemi-body radiation were accrued for the study. Patients not only had disseminated skeletal disease but, were heavily pretreated Seven patients were accrued for the study. Patients received 1 and 2 gms of TMG. 30-40 minutes before hemibody radiation. A dose of 600 cGy was delivered on telecobalt equipment at mid plane. Immediate Toxicities were evaluated as well as response to pain. Results: All the seven patients underwent radiation uneventfully. There was no drug related toxicity. Pain relief was adequate. Conclusion: Tocoferol monoglucoside an effective antioxidant with no significant acute toxicity, when administered in a dose of 1 or 2 gms per oral route. TMG being water-soluble can have global antioxidant and radio protective effects. This needs further clinical evaluation.

A Phase I Study of Short-Course Accelerated Whole Brain Radiation Therapy for Multiple Brain Metastases

Energy Technology Data Exchange (ETDEWEB)

Caravatta, Luciana; Deodato, Francesco; Ferro, Marica [Department of Radiation Oncology, Fondazione di Ricerca e Cura ' Giovanni Paolo II' , Universita Cattolica del S. Cuore, Campobasso (Italy); Macchia, Gabriella, E-mail: gmacchia@rm.unicatt.it [Department of Radiation Oncology, Fondazione di Ricerca e Cura ' Giovanni Paolo II' , Universita Cattolica del S. Cuore, Campobasso (Italy); Massaccesi, Mariangela [Department of Radiation Oncology, Fondazione di Ricerca e Cura ' Giovanni Paolo II' , Universita Cattolica del S. Cuore, Campobasso (Italy); Cilla, Savino [Medical Physics Unit, Fondazione di Ricerca e Cura ' Giovanni Paolo II,' Universita Cattolica del S. Cuore, Campobasso (Italy); Padula, Gilbert D.A. [Department of Radiation Oncology, The Lacks Cancer Center Saint Mary' s Health Care, Grand Rapids, Michigan (United States); Mignogna, Samantha; Tambaro, Rosa [Department of Palliative Therapies, Fondazione di Ricerca e Cura ' Giovanni Paolo II' , Universita Cattolica del S. Cuore, Campobasso (Italy); Carrozza, Francesco [Department of Oncology, A. Cardarelli Hospital, Campobasso (Italy); Flocco, Mariano [Madre Teresa di Calcutta Hospice, Larino (Italy); Cantore, Giampaolo [Department of Neurological Sciences, Istituto Neurologico Mediterraneo Neuromed, Istituto di Ricovero e Cura a Carattere Scientifico, Pozzilli (Italy); Scapati, Andrea [Department of Radiation Oncology, ' San Francesco' Hospital, Nuoro (Italy); Buwenge, Milly [Department of Radiotherapy, Mulago Hospital, Kampala (Uganda); and others

2012-11-15

Purpose: To define the maximum tolerated dose (MTD) of a SHort-course Accelerated whole brain RadiatiON therapy (SHARON) in the treatment of patients with multiple brain metastases. Methods and Materials: A phase 1 trial in 4 dose-escalation steps was designed: 12 Gy (3 Gy per fraction), 14 Gy (3.5 Gy per fraction), 16 Gy (4 Gy per fraction), and 18 Gy (4.5 Gy per fraction). Eligibility criteria included patients with unfavorable recursive partitioning analysis (RPA) class > or =2 with at least 3 brain metastases or metastatic disease in more than 3 organ systems, and Eastern Cooperative Oncology Group (ECOG) performance status {<=}3. Treatment was delivered in 2 days with twice-daily fractionation. Patients were treated in cohorts of 6-12 to define the MTD. The dose-limiting toxicity (DLT) was defined as any acute toxicity {>=}grade 3, according to the Radiation Therapy Oncology Group scale. Information on the status of the main neurologic symptoms and quality of life were recorded. Results: Characteristics of the 49 enrolled patients were as follows: male/female, 30/19; median age, 66 years (range, 23-83 years). ECOG performance status was <3 in 46 patients (94%). Fourteen patients (29%) were considered to be in recursive partitioning analysis (RPA) class 3. Grade 1-2 acute neurologic (26.4%) and skin (18.3%) toxicities were recorded. Only 1 patient experienced DLT (neurologic grade 3 acute toxicity). With a median follow-up time of 5 months (range, 1-23 months), no late toxicities have been observed. Three weeks after treatment, 16 of 21 symptomatic patients showed an improvement or resolution of presenting symptoms (overall symptom response rate, 76.2%; confidence interval 0.95: 60.3-95.9%). Conclusions: Short-course accelerated radiation therapy in twice-daily fractions for 2 consecutive days is tolerated up to a total dose of 18 Gy. A phase 2 study has been planned to evaluate the efficacy on overall survival, symptom control, and quality of life indices.

Wave Characteristics of Temperature Inversion Process of Nighttime Radiation,

Science.gov (United States)

1983-12-09

CHARACTERISTICS OF TEMPERATURE INVERSION PROCESS OF NIGHTTIME RADIATION By: Zhou Mingyu and Zhang ¥i English pages: 8 Source: Kexue Tongbao, 1982, pp. 156...lJournal of Meteorology], 39 (1981), 1:70-81. 3. Drazin, P. G., J. Fluid. Mech., 4 (1958), 214-224. 4. Zhou Mingyu et al., QIXIANG XUEBAO, 38 (1980), 3: 250...258. 5. Emnanuel, C. B., B-L. Meteor., 5(1973), N(1/2)8 19-27. 6. Zhou Mingyu et al., J. Acoust. Soc., A. m., 68 (1980), 1: 303-308. 8 I iI

Numerical research of dynamic characteristics in tower solar cavity receiver based on step-change radiation flux

Science.gov (United States)

Chen, Zhengwei; Wang, Yueshe; Hao, Yun; Wang, Qizhi

2013-07-01

The solar cavity receiver is an important light-energy to thermal-energy convector in the tower solar thermal power plant system. The heat flux in the inner surface of the cavity will show the characteristics of non-continuous step change especially in non-normal and transient weather conditions, which may result in a continuous dynamic variation of the characteristic parameters. Therefore, the research of dynamic characteristics of the receiver plays a very important role in the operation and the control safely in solar cavity receiver system. In this paper, based on the non-continuous step change of radiation flux, a non-linear dynamic model is put forward to obtain the effects of the non-continuous step change radiation flux and step change feed water flow on the receiver performance by sequential modular approach. The subject investigated in our study is a 1MW solar power station constructed in Yanqing County, Beijing. This study has obtained the dynamic responses of the characteristic parameters in the cavity receiver, such as drum pressure, drum water level, main steam flow and main steam enthalpy under step change radiation flux. And the influence law of step-change feed water flow to the dynamic characteristics in the receiver also has been analyzed. The results have a reference value for the safe operation and the control in solar cavity receiver system.

A dynamic phase microscopic study of optical characteristics of individual chloroplasts.

Science.gov (United States)

Tychinsky, V P; Kretushev, A V; Vyshenskaya, T V; Tikhonov, A N

2004-10-11

Dynamic phase microscopy (DPM) allows the monitoring of optical path difference (or phase height), h(x,y,t) approximately integraln(x,y,z,t)dz, an integral refractive index projection of the medium, n(x,y,z,t), in optically transparent biological specimens at high spatial and temporal resolutions. In this study, DPM was used for the analysis of fluctuations in the optical characteristics of individual bean chloroplasts in various metabolic states. A "phase image" of an individual chloroplast, which represents a three-dimensional plot of the "phase height", was obtained for the first time, and the frequency spectra of the fluctuations of h(x,y,t) were investigated. The fluctuation patterns, i.e., the intensity and the frequency spectra of phase height fluctuations in bean chloroplasts (Class B) were found to depend on their metabolic state. Under conditions of noncyclic (or pseudocyclic) electron transport, the fluctuations displayed characteristic frequencies in the range of 0.25-0.6 Hz and were space-time-correlated in the chloroplast domains with the cross sizes of approximately 2 microm. The fluctuation intensity decreased in the presence of uncouplers (nigericin and valinomycin, 20 microM). A stronger (in comparison with 20 microM valinomycin) effect of 20 microM nigericin suggests that the light-induced generation of the transmembrane pH difference (DeltapH) makes the main contribution to the increment of space-correlated fluctuations of h(x,y,t). Studies of chloroplasts incubated in media of various osmolarity (50-500 mM sucrose) have shown that structural changes in thylakoids are among other factors responsible for phase height fluctuations.

Characteristic and Wigner function for number difference and operational phase

International Nuclear Information System (INIS)

Fan Hongyi; Hu Haipeng

2004-01-01

We introduce the characteristic function in the sense of number difference-operational phase, and we employ the correlated-amplitude-number-difference state representation to calculate it. It results in the form of the corresponding Wigner function and Wigner operator. The marginal distributions of the generalized Wigner function are briefly discussed

Detailed Characteristics of Radiation Belt Electrons Revealed by CSSWE/REPTile Measurements

Science.gov (United States)

Zhang, K.; Li, X.; Schiller, Q.; Gerhardt, D. T.; Millan, R. M.

2016-12-01

The outer radiation belt electrons are highly dynamic. We study the detailed characteristics of the relativistic electrons in the outer belt using measurements from the Colorado Student Space Weather Experiment (CSSWE) mission, a low Earth orbit Cubesat, which transverses the radiation belt four times in one orbit ( 1.5 hr) and has the advantage of measuring the dynamic activities of the electrons including their rapid precipitations. Among the features of the relativistic electrons, we show the measured electron distribution as a function of geomagnetic activities and local magnetic field strength. Moreover, a specific precipitation band, which happened on 19 Jan 2013, is investigated based on the conjunctive measurement of CSSWE and the Balloon Array for Radiation belt Relativistic Electron Losses (BARREL). In this precipitation band event, the net loss of the 0.58 1.63 MeV electrons (L=3.5 6) is estimated to account for 6.84% of the total electron content.

Assimilation of spatio-temporal distribution of radionuclides in early phase of radiation accident

Czech Academy of Sciences Publication Activity Database

Hofman, Radek; Šmídl, Václav

2010-01-01

Roč. 18, 7/8 (2010), s. 226-228 ISSN 1210-7085 R&D Projects: GA MŠk(CZ) 1M0572; GA ČR(CZ) GA102/07/1596 Institutional research plan: CEZ:AV0Z10750506 Keywords : decision support * early phase * Gaussian model * radioactive pollution transport Subject RIV: DL - Nuclear Waste, Radioactive Pollution ; Quality http://library.utia.cas.cz/separaty/2010/AS/hofman-assimilation of spatio-temporal distribution of radionuclides in early phase of radiation accident .pdf

Dosimetric characteristics and radiation monitoring with CaSO4(Dy):NaCl pellets

International Nuclear Information System (INIS)

Kathuria, S.P.; Campos, L.L.; Gordon, A.M.P.L.

1981-06-01

CaSO 4 (Dy):NaCl Tl dosimeters, in the form of pellets, are used in the field for a period of one month. Before using these pellets for environmental and personnel radiation monitoring some of the important dosimetric characteristics like fading reusability and effect of ambient light are investigated and described. The pellets are used with plastic and lead filters for personnel and environmental radiation monitoring and the results obtained with the lead filters are in good agreement with those of the energy independent LiF dosimeters. A new combination of plastic, aluminium and lead filters is suggested for dose measurements in a mixed field of X, gamma and beta radiations. (Author) [pt

Characteristics of outage radiation fields around various reactor components

International Nuclear Information System (INIS)

Verzilov, Y.; Husain, A.; Corbin, G.

2008-01-01

Full text: Activity monitoring surveys, consisting of gamma spectroscopy and dose rate measurements, of various CANDU station components such as the reactor face, feeder cabinet, steam generators and moderator heat exchangers are often performed during shutdown in order to trend the transport of activity around the primary heat transport and moderator systems. Recently, the increased dose expenditure for work such as feeder inspection and replacement in the reactor vault has also spurred interest in improved characterization of the reactor face fields to facilitate better ALARA decision making and hence a reduction in future dose expenditures. At present, planning for reactor face work is hampered by insufficient understanding of the relative contribution of the various components to the overall dose. In addition to the increased dose expenditure for work at the reactor face, maintenance work associated with horizontal flux detectors and liquid injection systems has also resulted in elevated dose expenditures. For instance at Darlington, radiation fields in the vicinity of horizontal flux detectors (HFD) and Liquid Injection Shutdown System (LISS) nozzle bellows are trending upwards with present contact fields being in the range 16-70 rem/h and working distance fields being in the range 100-500 mrem/h. This paper presents findings based on work currently being funded by the CANDU Owners Group. Measurements were performed at Ontario Power Generation's Pickering and Darlington nuclear stations. Specifically, the following are addressed: Characteristics of Reactor Vault Fields; Characteristics of Steam Generator Fields; Characteristics of Moderator Heat Exchanger Fields. Measurements in the reactor vault were performed at the reactor face, along the length of end fittings, along the length of feeders, at the bleed condenser and at the HFD and LISS nozzle bellows. Steam generator fields were characterized at various elevations above the tube sheet, with and without the

A Study on the Response Characteristics of a Fiber-Optic Radiation Sensor Model Based on Cerenkov Principle

Energy Technology Data Exchange (ETDEWEB)

Han, Hwa Jeong; Kim, Beom Kyu; Park, Byung Gi [Soonchunhyang Univ., Asan (Korea, Republic of)

2016-10-15

In recent year, various fiber-optic radiation sensors using Cerenkov principle have been developed without employing any scintillators for measuring high-energy photon, electron, etc. The main advantages of the optical fibers are the remote transmission of the light signal and immunity to pressure and electromagnetic waves. Therefore, the sensors utilizing the optical fibers can be used in hazardous radiation environments, such as the high-level radiation areas of a nuclear facility. The study to be simulated a fiber-optic radiation sensor based on Cerenkov principle and to be analyzed the response characteristics of the sensor. For the aforementioned study, the GEANT simulation toolkit was used. It is able to take into all the optical properties of fibers and is found to be appropriate to realistically describe the response of fiber-optic radiation sensor. In the recently, the fiber-optic radiation sensor have been developed in nuclear industry. Because sensor can detect gamma ray in harsh nuclear environments. In this study, we analyzed response characteristics of the fiber-optic radiation sensor. We have simulated the Monte Carlo model, for detecting the Cerenkov radiation using the fiber-optic radiation sensor. And the y-axis distribution of Cerenkov photons was obtained using output file. Simulation is performed with reference to the method of the previous research, and then the simulation results exhibited a good agreement with the previous research.

A Study on the Response Characteristics of a Fiber-Optic Radiation Sensor Model Based on Cerenkov Principle

International Nuclear Information System (INIS)

Han, Hwa Jeong; Kim, Beom Kyu; Park, Byung Gi

2016-01-01

In recent year, various fiber-optic radiation sensors using Cerenkov principle have been developed without employing any scintillators for measuring high-energy photon, electron, etc. The main advantages of the optical fibers are the remote transmission of the light signal and immunity to pressure and electromagnetic waves. Therefore, the sensors utilizing the optical fibers can be used in hazardous radiation environments, such as the high-level radiation areas of a nuclear facility. The study to be simulated a fiber-optic radiation sensor based on Cerenkov principle and to be analyzed the response characteristics of the sensor. For the aforementioned study, the GEANT simulation toolkit was used. It is able to take into all the optical properties of fibers and is found to be appropriate to realistically describe the response of fiber-optic radiation sensor. In the recently, the fiber-optic radiation sensor have been developed in nuclear industry. Because sensor can detect gamma ray in harsh nuclear environments. In this study, we analyzed response characteristics of the fiber-optic radiation sensor. We have simulated the Monte Carlo model, for detecting the Cerenkov radiation using the fiber-optic radiation sensor. And the y-axis distribution of Cerenkov photons was obtained using output file. Simulation is performed with reference to the method of the previous research, and then the simulation results exhibited a good agreement with the previous research

The relationship of sick leave benefits, employment patterns, and individual characteristics to radiation therapy-related fatigue.

Science.gov (United States)

Poirier, Patricia

2006-05-03

To examine the relationship among sick leave benefits, employment patterns, individual characteristics, and fatigue in patients receiving radiation therapy. Prospective, longitudinal design. A community hospital radiation oncology department. 77 patients receiving radiation therapy to the breast, chest, head and neck, pelvis, or prostate. All were employed at the time of diagnosis. The Piper Integrated Fatigue Model guided the study. The Revised Piper Fatigue Scale (PFS), Brief Fatigue Inventory, and a single-item scale were used to measure five dimensions of subjective fatigue. Sick leave, employment, individual characteristics, and fatigue were measured at baseline, weekly during treatment, and at one month post-treatment. Employment patterns, availability of sick leave benefits, and fatigue. Mean total fatigue scores on the PFS ranged from 0-4.77 at baseline (mean = 0.46, SD = 0.93), 0-8.77 at the completion of treatment (mean = 2.84, SD = 2.40), and 0-4.82 at one month post-treatment (mean = 0.77, SD = 1.20). Side effects, education, living situation, age, treatment site, and work were associated with fatigue along the trajectory of radiation therapy. Study participants who were working at the end of radiation had lower fatigue scores than those who were not. Availability of sick leave benefits was associated with employment patterns during treatment. Work may have benefits during radiation therapy but may be affected by radiation therapy-related fatigue. Management of treatment side effects, including fatigue, may help patients remain in the workforce during radiation.

Gamma radiation for all phases of life cycle of cotton bollworm Helicoverpa armigera aiming at its control

International Nuclear Information System (INIS)

Haddad, Gianni Q.; Arthur, Valter

2017-01-01

Since the 1950s, scientists have used ionizing radiation to sterilize insects, which are released in nature to mate, but without any progeny. Known as the sterile insect technique (SIT), this insect control method traditionally uses ionizing radiations to sterilize insects, being a technique that does not generate residue, and can act in synergy with the other techniques within integrated pest management. For several years, Brazil has been fighting against the increase of pests, introducing new tactics and techniques within IPM programs, to overcome the resistance of chemical products, such as: reducing residues of pesticides. For some important crops of our country, we have a wide spectrum of pests occurring from beginning to end of the harvest, one of them is the cotton crop and among the key pests of this crop, we have some extremely important caterpillars among them Helicoverpa armigera. Due to this the objective this study was establishes doses of gamma radiation to sterilizing of the phases of : eggs, larvae, pupae and adults of H. armigera aiming their control. The experiment was carried out with application of gamma radiation from a Cobalt-60 source. The treatments consisted of doses of gamma radiation varying of according with the insect phase, being this variation of: 0 (control) to 400 Gy. The experiments with pupae and adult phases showed satisfactory results in the sterilization of H. armigera for use in autocide control programs. The sterilize dose to adult and pupae phase were 400 Gy and 100 Gy respectively, being the best doses for the application of the sterile insect technique to this pest in cotton. (author)

Gamma radiation for all phases of life cycle of cotton bollworm Helicoverpa armigera aiming at its control

Energy Technology Data Exchange (ETDEWEB)

Haddad, Gianni Q.; Arthur, Valter, E-mail: ghaddad2001@yahoo.com.br, E-mail: arthur@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil). Laboratório de Radiobiologia e Ambiente; Machi, André R., E-mail: rica_machi@hotmail.com [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

2017-07-01

Since the 1950s, scientists have used ionizing radiation to sterilize insects, which are released in nature to mate, but without any progeny. Known as the sterile insect technique (SIT), this insect control method traditionally uses ionizing radiations to sterilize insects, being a technique that does not generate residue, and can act in synergy with the other techniques within integrated pest management. For several years, Brazil has been fighting against the increase of pests, introducing new tactics and techniques within IPM programs, to overcome the resistance of chemical products, such as: reducing residues of pesticides. For some important crops of our country, we have a wide spectrum of pests occurring from beginning to end of the harvest, one of them is the cotton crop and among the key pests of this crop, we have some extremely important caterpillars among them Helicoverpa armigera. Due to this the objective this study was establishes doses of gamma radiation to sterilizing of the phases of : eggs, larvae, pupae and adults of H. armigera aiming their control. The experiment was carried out with application of gamma radiation from a Cobalt-60 source. The treatments consisted of doses of gamma radiation varying of according with the insect phase, being this variation of: 0 (control) to 400 Gy. The experiments with pupae and adult phases showed satisfactory results in the sterilization of H. armigera for use in autocide control programs. The sterilize dose to adult and pupae phase were 400 Gy and 100 Gy respectively, being the best doses for the application of the sterile insect technique to this pest in cotton. (author)

Mesenchymal Stem Cells Retain Their Defining Stem Cell Characteristics After Exposure to Ionizing Radiation

International Nuclear Information System (INIS)

Nicolay, Nils H.; Sommer, Eva; Lopez, Ramon; Wirkner, Ute; Trinh, Thuy; Sisombath, Sonevisay; Debus, Jürgen; Ho, Anthony D.; Saffrich, Rainer; Huber, Peter E.

2013-01-01

Purpose: Mesenchymal stem cells (MSCs) have the ability to migrate to lesion sites and undergo differentiation into functional tissues. Although this function may be important for tissue regeneration after radiation therapy, the influence of ionizing radiation (IR) on cellular survival and the functional aspects of differentiation and stem cell characteristics of MSCs have remained largely unknown. Methods and Materials: Radiation sensitivity of human primary MSCs from healthy volunteers and primary human fibroblast cells was examined, and cellular morphology, cell cycle effects, apoptosis, and differentiation potential after exposure to IR were assessed. Stem cell gene expression patterns after exposure to IR were studied using gene arrays. Results: MSCs were not more radiosensitive than human primary fibroblasts, whereas there were considerable differences regarding radiation sensitivity within individual MSCs. Cellular morphology, cytoskeletal architecture, and cell motility were not markedly altered by IR. Even after high radiation doses up to 10 Gy, MSCs maintained their differentiation potential. Compared to primary fibroblast cells, MSCs did not show an increase in irradiation-induced apoptosis. Gene expression analyses revealed an upregulation of various genes involved in DNA damage response and DNA repair, but expression of established MSC surface markers appeared only marginally influenced by IR. Conclusions: These data suggest that human MSCs are not more radiosensitive than differentiated primary fibroblasts. In addition, upon photon irradiation, MSCs were able to retain their defining stem cell characteristics both on a functional level and regarding stem cell marker expression

Dose and diagnostic performance comparison between phase-contrast mammography with synchrotron radiation and digital mammography: a clinical study report.

Science.gov (United States)

Fedon, Christian; Rigon, Luigi; Arfelli, Fulvia; Dreossi, Diego; Quai, Elisa; Tonutti, Maura; Tromba, Giuliana; Cova, Maria Assunta; Longo, Renata

2018-01-01

Two dosimetric quantities [mean glandular dose (MGD) and entrance surface air kerma (ESAK)] and the diagnostic performance of phase-contrast mammography with synchrotron radiation (MSR) are compared to conventional digital mammography (DM). Seventy-one patients (age range, 41 to 82 years) underwent MSR after a DM examination if questionable or suspicious breast abnormalities were not clarified by ultrasonography. The MGD and the ESAK delivered in both examinations were evaluated and compared. Two on-site radiologists rated the images in consensus according to the Breast Imaging Reporting and Data System assessment categories, which were then correlated with the final diagnoses by means of statistical generalized linear models (GLMs). Receiver operating characteristic curves were also used to assess the diagnostic performance by comparing the area under the curve (AUC). An important MGD and ESAK reduction was observed in MSR due to the monoenergetic beam. In particular, an average 43% reduction was observed for the MGD and a reduction of more than 50% for the ESAK. GLM showed higher diagnostic accuracy, especially in terms of specificity, for MSR, confirmed by AUC analysis ([Formula: see text]). The study design implied that the population was characterized by a high prevalence of disease and that the radiologists, who read the DM images before referring the patient to MSR, could have been influenced in their assessments. Within these limitations, the use of synchrotron radiation with the phase-contrast technique applied to mammography showed an important dose reduction and a higher diagnostic accuracy compared with DM. These results could further encourage research on the translation of x-ray phase-contrast imaging into the clinics.

Characteristics and stability analyses of transient one-dimensional two-phase flow equations and their finite difference approximations

International Nuclear Information System (INIS)

Lyczkowski, R.W.; Gidaspow, D.; Solbrig, C.W.; Hughes, E.D.

1975-01-01

Equation systems describing one-dimensional, transient, two-phase flow with separate continuity, momentum, and energy equations for each phase are classified by use of the method of characteristics. Little attempt is made to justify the physics of these equations. Many of the equation systems possess complex-valued characteristics and hence, according to well-known mathematical theorems, are not well-posed as initial-value problems (IVPs). Real-valued characteristics are necessary but not sufficient to insure well-posedness. In the absence of lower order source or sink terms (potential type flows), which can affect the well-posedness of IVPs, the complex characteristics associated with these two-phase flow equations imply unbounded exponential growth for disturbances of all wavelengths. Analytical and numerical examples show that the ill-posedness of IVPs for the two-phase flow partial differential equations which possess complex characteristics produce unstable numerical schemes. These unstable numerical schemes can produce apparently stable and even accurate results if the growth rate resulting from the complex characteristics remains small throughout the time span of the numerical experiment or if sufficient numerical damping is present for the increment size used. Other examples show that clearly nonphysical numerical instabilities resulting from the complex characteristics can be produced. These latter types of numerical instabilities are shown to be removed by the addition of physically motivated differential terms which eliminate the complex characteristics. (auth)

Improvement of radiation response characteristic on CdTe detectors using fast neutron irradiation

International Nuclear Information System (INIS)

Miyamaru, Hiroyuki; Takahashi, Akito; Iida, Toshiyuki

1999-01-01

The treatment of fast neutron pre-irradiation was applied to a CdTe radiation detector in order to improve radiation response characteristic. Electron transport property of the detector was changed by the irradiation effect to suppress pulse amplitude fluctuation in risetime. Spectroscopic performance of the pre-irradiated detector was compared with the original. Additionally, the pre-irradiated detector was employed with a detection system using electrical signal processing of risetime discrimination (RTD). Pulse height spectra of 241 Am, 133 Ba, and 137 Cs gamma rays were measured to examine the change of the detector performance. The experimental results indicated that response characteristic for high-energy photons was improved by the pre-irradiation. The combination of the pre-irradiated detector and the RTD processing was found to provide further enhancement of the energy resolution. Application of fast neutron irradiation effect to the CdTe detector was demonstrated. (author)

Synchrotron radiation: its characteristics and applications

International Nuclear Information System (INIS)

Blewett, J.P.; Chasman, R.; Green, G.K.

1977-01-01

It has been known for a century that charged particles radiate when accelerated and that relativistic electrons in the energy range between 100 MeV and several GeV and constrained to travel in circular orbits emit concentrated, intense beams with broad continuous spectra that can cover the electromagnetic spectrum from infrared through hard X-rays. Recently the possible applications of this radiation have been appreciated and electron synchrotrons and electron storage rings are now being used in many centers for studies of the properties of matter in the solid, liquid and gaseous states. A brief history is presented of ''synchrotron radiation'' as it is now called. The basic properties of this radiation are described and the world-wide distribution is indicated of facilities for its production. Particular attention is given to the proposed facility at Brookhaven which will be the first major installation to be dedicated only to the production and use of synchrotron radiation. Finally, typical examples are given of applications in the areas of radiation absorption studies, techniques based on scattering of radiation, and advances based on X-ray lithography

Centralizing and decentralizing the system for unifying measurements on ionizing-radiation characteristics (medium-energy photon and charged-particle radiometry and spectrometry)

International Nuclear Information System (INIS)

Bregadze, Yu.I.; Stepanov, E.K.

1993-01-01

Ionizing-radiation applications have gradually defined the physical quantities needed to describe radiation sources, radiation as such, and interactions with matter. The optimum unit system has not yet been defined, since new regularities appear during research on the interactions of radiation with matter, and new relationships are being discovered between the radiation characteristics and the observed effects. There are 13 state primary standards in the measurement of ionizing radiation. Several of the standards reproduce the same unit but for different forms of radiation, while special standards reproduce units under special conditions. The present article discusses the various approaches to centralizing and decentralizing systems of supporting unified measurements for various ionizing-radiation characteristics. The three basic physical quantities used to characterize radioactive sources -- radionuclide activity, external particle emission, and particle energy -- are addressed separately. 10 refs

Calculation and construction of radioisotopic radiation chemical installations. [Book (reference text); In Russian]. Raschet i konstruirovanie radioizotopnykh radiatsionno-khimicheskikh ustanovok

Energy Technology Data Exchange (ETDEWEB)

Kulisha, E E

1975-01-01

A discussion is given of the development of radiation sources and the uses of gamma sources. The chemical and radiation characteristics of the sources are considered, and the fabrication methods are described for different types of sources used for radiation-induced chemical processes in condensed phase and in two-phase systems. Technological dosimetry, industrial and radiation safety, and economic aspects of gamma sources are examined. The text serves as a reference for physicists, chemistry technologists, engineers, and other scientific workers.

Radiation and phase change of lithium fluoride in an annulus

Science.gov (United States)

Lund, Kurt O.

1993-01-01

A one-dimensional thermal model is developed to evaluate the effect of radiation on the phase change of lithium-fluoride (LiF) in an annular canister under gravitational and microgravitational conditions. Specified heat flux at the outer wall of the canister models focused solar flux; adiabatic and convective conditions are considered for the inner wall. A two-band radiation model is used for the combined-mode heat transfer within the canister, and LiF optical properties relate metal surface properties in vacuum to those in LiF. For axial gravitational conditions, the liquid LiF remains in contact with the two bounding walls, whereas a void gap is used at the outer wall to model possible microgravitational conditions. For the adiabatic cases, exact integrals are obtained for the time required for complete melting of the LiF. Melting was found to occur primarily from the outer wall in the 1-g model, whereas it occurred primarily from the inner wall in the mu-g model. For the convective cases, partially melted steady-state conditions and fully melted conditions are determined to depend on the source flux level, with radiation extending the melting times.

Preoperative Single-Fraction Partial Breast Radiation Therapy: A Novel Phase 1, Dose-Escalation Protocol With Radiation Response Biomarkers

Energy Technology Data Exchange (ETDEWEB)

Horton, Janet K., E-mail: janet.horton@duke.edu [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Blitzblau, Rachel C.; Yoo, Sua [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Geradts, Joseph [Department of Pathology, Duke University Medical Center, Durham, North Carolina (United States); Chang, Zheng [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Baker, Jay A. [Department of Radiology, Duke University Medical Center, Durham, North Carolina (United States); Georgiade, Gregory S. [Department of Surgery, Duke University Medical Center, Durham, North Carolina (United States); Chen, Wei [Department of Bioinformatics: Duke Cancer Institute, Duke University Medical Center, Durham, North Carolina (United States); Siamakpour-Reihani, Sharareh; Wang, Chunhao [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Broadwater, Gloria [Department of Biostatistics: Duke Cancer Institute, Duke University Medical Center, Durham, North Carolina (United States); Groth, Jeff [Department of Pathology, Duke University Medical Center, Durham, North Carolina (United States); Palta, Manisha; Dewhirst, Mark [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Barry, William T. [Department of Biostatistics and Bioinformatics, Duke University Medical Center, Durham, North Carolina (United States); Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, Massachusetts (United States); Duffy, Eileen A. [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); and others

2015-07-15

Purpose: Women with biologically favorable early-stage breast cancer are increasingly treated with accelerated partial breast radiation (PBI). However, treatment-related morbidities have been linked to the large postoperative treatment volumes required for external beam PBI. Relative to external beam delivery, alternative PBI techniques require equipment that is not universally available. To address these issues, we designed a phase 1 trial utilizing widely available technology to 1) evaluate the safety of a single radiation treatment delivered preoperatively to the small-volume, intact breast tumor and 2) identify imaging and genomic markers of radiation response. Methods and Materials: Women aged ≥55 years with clinically node-negative, estrogen receptor–positive, and/or progesterone receptor–positive HER2−, T1 invasive carcinomas, or low- to intermediate-grade in situ disease ≤2 cm were enrolled (n=32). Intensity modulated radiation therapy was used to deliver 15 Gy (n=8), 18 Gy (n=8), or 21 Gy (n=16) to the tumor with a 1.5-cm margin. Lumpectomy was performed within 10 days. Paired pre- and postradiation magnetic resonance images and patient tumor samples were analyzed. Results: No dose-limiting toxicity was observed. At a median follow-up of 23 months, there have been no recurrences. Physician-rated cosmetic outcomes were good/excellent, and chronic toxicities were grade 1 to 2 (fibrosis, hyperpigmentation) in patients receiving preoperative radiation only. Evidence of dose-dependent changes in vascular permeability, cell density, and expression of genes regulating immunity and cell death were seen in response to radiation. Conclusions: Preoperative single-dose radiation therapy to intact breast tumors is well tolerated. Radiation response is marked by early indicators of cell death in this biologically favorable patient cohort. This study represents a first step toward a novel partial breast radiation approach. Preoperative radiation should

Preoperative Single-Fraction Partial Breast Radiation Therapy: A Novel Phase 1, Dose-Escalation Protocol With Radiation Response Biomarkers

International Nuclear Information System (INIS)

Horton, Janet K.; Blitzblau, Rachel C.; Yoo, Sua; Geradts, Joseph; Chang, Zheng; Baker, Jay A.; Georgiade, Gregory S.; Chen, Wei; Siamakpour-Reihani, Sharareh; Wang, Chunhao; Broadwater, Gloria; Groth, Jeff; Palta, Manisha; Dewhirst, Mark; Barry, William T.; Duffy, Eileen A.

2015-01-01

Purpose: Women with biologically favorable early-stage breast cancer are increasingly treated with accelerated partial breast radiation (PBI). However, treatment-related morbidities have been linked to the large postoperative treatment volumes required for external beam PBI. Relative to external beam delivery, alternative PBI techniques require equipment that is not universally available. To address these issues, we designed a phase 1 trial utilizing widely available technology to 1) evaluate the safety of a single radiation treatment delivered preoperatively to the small-volume, intact breast tumor and 2) identify imaging and genomic markers of radiation response. Methods and Materials: Women aged ≥55 years with clinically node-negative, estrogen receptor–positive, and/or progesterone receptor–positive HER2−, T1 invasive carcinomas, or low- to intermediate-grade in situ disease ≤2 cm were enrolled (n=32). Intensity modulated radiation therapy was used to deliver 15 Gy (n=8), 18 Gy (n=8), or 21 Gy (n=16) to the tumor with a 1.5-cm margin. Lumpectomy was performed within 10 days. Paired pre- and postradiation magnetic resonance images and patient tumor samples were analyzed. Results: No dose-limiting toxicity was observed. At a median follow-up of 23 months, there have been no recurrences. Physician-rated cosmetic outcomes were good/excellent, and chronic toxicities were grade 1 to 2 (fibrosis, hyperpigmentation) in patients receiving preoperative radiation only. Evidence of dose-dependent changes in vascular permeability, cell density, and expression of genes regulating immunity and cell death were seen in response to radiation. Conclusions: Preoperative single-dose radiation therapy to intact breast tumors is well tolerated. Radiation response is marked by early indicators of cell death in this biologically favorable patient cohort. This study represents a first step toward a novel partial breast radiation approach. Preoperative radiation should

Effects of exogenous cyclic AMP on growth characteristics and radiation response of Reuber H35 hepatoma cells

International Nuclear Information System (INIS)

van Rijn, J.; van Den Berg, J.; van Meeteren, A.; van Wijk, R.

1983-01-01

Reuber H35 rat hepatoma cells, clone KRC, were used to study the effect of cyclic AMP on radiation-induced cell death. Treatment of logarithmically growing cultures with 0.5 mM cAMP for 17 hr prior to irradiation resulted in a decreased cell survival. Similar results were obtained with cultures irradiated after treatment with Bt 2 cAMP. Treatment of H35 cells with cAMP or Bt 2 cAMP caused inhibition of their proliferation and resulted in an accumulation of cells in early S phase and depletion of G2-phase cells. In synchronized cultures cells were relatively radioresistant during their S phase. In addition to single-dose treatment with X rays, the effect of Bt 2 cAMP on radiation-induced cell death was studied during fractionated irradiation wtih 2.5 Gy per day. This fractionated irradiation resulted in a dose-reduction factor of 1.6 at the 10% survival level and a 10-fold decrease in the surviving cell population due to the cooperative effects of Bt 2 cAMP on growth rate and radiation survival. The effect of cAMP on radiation-induced mitotic delay was also studied. It appeared that where cAMP had on effect on the progression of G2 cells into mitosis, it prevented cells from recovery from the X-ray mitotic delay in G2

Evaluation of the Effects of Prostate Radiation Therapy on Occludin Expression and Ultrasonography Characteristics of the Bladder

DEFF Research Database (Denmark)

Baradaran-Ghahfarokhi, Milad; Amouheidari, Alireza; Shahbazi-Gahrouei, Daryoush

2017-01-01

PURPOSE: To evaluate the effects of radiation dose in prostate radiation therapy (RT) on occludin expression and ultrasonography characteristics of the bladder. METHODS AND MATERIALS: Urine samples of 64 prostate RT patients were collected before, at regular intervals during, and 3 months after R...

Parallel Computing Characteristics of Two-Phase Thermal-Hydraulics code, CUPID

International Nuclear Information System (INIS)

Lee, Jae Ryong; Yoon, Han Young

2013-01-01

Parallelized CUPID code has proved to be able to reproduce multi-dimensional thermal hydraulic analysis by validating with various conceptual problems and experimental data. In this paper, the characteristics of the parallelized CUPID code were investigated. Both single- and two phase simulation are taken into account. Since the scalability of a parallel simulation is known to be better for fine mesh system, two types of mesh system are considered. In addition, the dependency of the preconditioner for matrix solver was also compared. The scalability for the single-phase flow is better than that for two-phase flow due to the less numbers of iterations for solving pressure matrix. The CUPID code was investigated the parallel performance in terms of scalability. The CUPID code was parallelized with domain decomposition method. The MPI library was adopted to communicate the information at the interface cells. As increasing the number of mesh, the scalability is improved. For a given mesh, single-phase flow simulation with diagonal preconditioner shows the best speedup. However, for the two-phase flow simulation, the ILU preconditioner is recommended since it reduces the overall simulation time

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

Directory of Open Access Journals (Sweden)

R. Herschmann

2007-06-01

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

Radiation-induced p53 protein response in the A549 cell line is culture growth-phase dependent

Energy Technology Data Exchange (ETDEWEB)

Johnson, N.F.; Gurule, D.M.; Carpenter, T.R.

1995-12-01

One role of the p53 tumor suppressor protein has been recently revealed. Kastan, M.B. reported that p53 protein accumulates in cells exposed to ionizing radiation. The accumulation of p53 protein is in response to DNA damage, most importantly double-strand breaks, that results from exposure to ionizing radiation. The rise in cellular p53 levels is necessary for an arrest in the G{sub 1} phase of the cell cycle to provide additional time for DNA repair. The p53 response has also been demonstrated to enhance PCNA-dependent repair. p53 is thus an important regulator of the cellular response to DNA-damaging radiation. From this data, it can be concluded that the magnitude of the p53 response is not dependent on the phase of culture growth.

Investigation of the propagation characteristics in turbulent dispersed two-phase flow

International Nuclear Information System (INIS)

Sami, S.M.

1980-01-01

The propagation characteristics of turbulent dispersed two-phase flows have been studied experimentally using the Pitot tube associated with a conical hot-film anemometer. It is found that the mixture velocity increases with decreasing volumetric mixing ratio of the air and water. The void fraction distribution shows homogeneity across the test section in the special case of fully developed boundary layer two-phase flow. An expression is obtained which relates the local mixture velocity to the local void fraction, gas and liquid densities, and volumetric gas-liquid ratio

Mixed phase clouds: observations and theoretical advances (overview)

Science.gov (United States)

Korolev, Alexei

2013-04-01

Mixed phase clouds play important role in precipitation formation and radiation budget of the Earth. The microphysical measurements in mixed phase clouds are notoriously difficult due to many technical challenges. The airborne instrumentation for characterization of the microstructure of mixed phase clouds is discussed. The results multiyear airborne observations and measurements of frequency of occurrence of mixed phase, characteristic spatial scales, humidity in mixed phase and ice clouds are presented. A theoretical framework describing the thermodynamics and phase transformation of a three phase component system consisting of ice particles, liquid droplets and water vapor is discussed. It is shown that the Wegener-Bergeron-Findeisen process plays different role in clouds with different dynamics. The problem of maintenance and longevity of mixed phase clouds is discussed.

Phase I/II trial of concurrent use of S-1 and radiation therapy for T2 glottic cancer

International Nuclear Information System (INIS)

Nakayama, Meijin; Hayakawa, Kazushige; Okamoto, Makito; Niibe, Yuzuru; Ishiyama, Hiromichi; Kotani, Shouko

2010-01-01

A Phase I/II study of S-1 combined radiation therapy was conducted in patients with Stage II (T2N0) glottic cancer. The purpose of the Phase I study was to identify the maximum tolerated dose, the recommended dose and the dose limiting toxicity. The objectives in the phase II study were to estimate the local control and the overall survival, and the incidence of adverse events. In Phase I, S-1 was administered orally in a split-course fashion as two doses of 40 mg/m 2 , for a total daily dose of 80 mg/m 2 . The course involved a 2-week rest after a 2-week administration (Level 1) and a 1-week rest after a 3-week administration (Level 2). Radiation therapy was administered in 2-Gy daily (total 60-Gy) standard fractionation. Seven patients were enrolled in the Phase I, and 19 in the Phase II study. Mucositis was the most common toxicity encountered. All 26 patients completed radiation therapy without delay. The overall response rate was 100% (26/26) with all patients showing a complete response. One patient developed a local recurrence 28 months after the treatment. The 3-year local control and overall survival rates were 94.7 and 85.4%, respectively (limited to 22 patients from Level 2). The use of S-1 at 80 mg/m 2 per day in a split-course with 1-week rest during the course of radiation therapy was safe and effective for Stage II glottic cancer. The treatment strategy employing orally available S-1 proved to be beneficial over the conventional injection of antitumor agents for maintaining the patients' quality of life. (author)

Radiation-induced chromosomal aberrations in the lymphocytes of various species of mammals and the influence of coffeine during the G-2 phase

International Nuclear Information System (INIS)

Rosenthal, M.

1983-01-01

The cellular kinetics and the G0-radiation sensitivity of human, chimpanzee, swine and rabbit lymphocytes were investigated using the lymphocytes test system (Ham's F-10 Medium, PHA). Due to the integration of BrdU in the DNA (S-phase), the author was able to distinguish between first, second and third mitoses (M1, M2, M3) in accordance with the differential colouring of the metaphase chromosomes which took place according to the labelling pattern. When checking the G0-radiation sensitivity of the lymphocytes, the rates of chromosomal aberrations in the metaphases of the first and second mitoses were evaluated separately. The different radiation sensitivities are thought to be due to interspecies differences in the repair capacity of the lymphocytes. In the metaphases of second mitoses, the rate of dicentric chromosomes is approximately half of that in M1-metaphases. Ring chromosomes were nearly as frequent in M2-metaphases as in M1-metaphases. In the second experimental phase, the effects of coffein on the aberration rates after radiation exposure of the lymphocytes in the G2 phase was investigated. Achromatic lesions, open chromatide breaks, and translocations were evaluated. Aberration rates were found to increase with the radiation dose and to decrease with the cultivation time after radiation exposure. There was no marked effect of coffein on the aberration rates. The progress of the G2 phase was measured in terms of the rate of radioactively labelled metaphases, which increased with the cultivation time. This labelling index was lower in the exposed cultures than in the control cultures, suggesting a radiation-induced delay of the G2 phase. The labelling indexes of all cultures were enhanced after coffein treatment, suggesting a coffein-induced acceleration of the G2 phase. (orig./MG) [de

Japanese contributions to IAEA INTOR workshop, phase IIA

International Nuclear Information System (INIS)

Fujisawa, Noboru; Sugihara, Masayoshi; Shimada, Michiya; Saito, Seiji.

1982-11-01

This report corresponds to Chapter VI of Japanese contribution report to IAEA INTOR workshop, Phase IIA. Special emphasis is placed on pumped limiter analysis for comparative studies between limiter and divertor concepts. Pumping characteristics of divertor/limiter and radiation cooling of diverted plasmas by impurities are also intensively studied. (author)

Changes in the Characteristics of Water-in-Oil-based High Internal ...

African Journals Online (AJOL)

Changes in the Characteristics of Water-in-Oil-based High Internal Phase Emulsion Containing Moringa Leaves Extract at Various Storage Conditions. ... Conclusion: Moringa HIPE showed stability and can be guided exclusively to protect skin against ultraviolet radiation-mediated oxidative damage. Keywords: Moringa ...

Improving microwave antenna gain and bandwidth with phase compensation metasurface

Directory of Open Access Journals (Sweden)

Ke Chen

2015-06-01

Full Text Available Metasurface, as a planar version of artificial metamaterial, provide an effective way to manipulate electromagnetic wave propagation. Here, we present a transparent metasurface for compensating the out-of-phase radiation from a microstrip patch antenna to improve its radiation gain and bandwidth. Based on the equivalence principle of Huygens’ surface, we propose metasurface composed of both inductive and capacitive resonant elements which could produce high transmission with variable phase characteristics. Such metasurface mounted on a patch antenna can transform the spherical-like phase profile generated from the patch into an in-phase planar one. A prototype antenna has been fabricated and validated the squeezed radiation pattern with suppressed sidelobes as well as enhanced impedance bandwidth due to strong near-field coupling. As operating at around 5.7 GHz, the proposed antenna may have potential application in wireless communication systems especially for point-to-point data transmission. It is believed that the design methodology could also be scaled to other frequency bands such as millimeter or terahertz wave.

The effect of cloud shape on radiative characteristics

International Nuclear Information System (INIS)

Welch, R.M.; Zdunkowski, W.G.

1981-01-01

Cumulus cloud radiative characteristics are calculated using Monte-Carlo codes as a function of solar zenith angle for clouds approximated by hemispherical, cylindrical and combination-type geometries. Values of cloud reflectivity, transmissivity and absorptivity are compared with values computed from assuming cubic and rectangular geometries, the basis for most previous finite cloud calculations. Poor agreement is obtained at large cloud sizes and only marginal agreement is obtained at small cloud sizes. Two approximations based upon various scalings of cloud optical depth (extinction parameters) are also constructed, but with limited success in reproducing the values produced by the convex shaped clouds. Reasonable agreement among the various approximations occurs at large solar zenith angles, but extremely poor agreement may occur at small angles. (orig./WB) [de

A study on the crack inspection signal characteristics for power plant components by phased array UT

International Nuclear Information System (INIS)

Cho, Yong Sang; Lim, Sang Gyu; Kil, Du Song

2001-01-01

Phased array ultrasonic testing system has become available for practical application in complicated geometry such as turbine blade root, tenon, disc in power industry. This research describes the characteristics of phased array UT signal for various type of blade roots in thermal Power Plant turbines. This application of Phased array ultrasonic testing system has been promoted mainly to save inspection time and labor cost of turbine inspection. The characteristic of phase array UT signal for power plant component is very simple to understand but to difficult for perform the inspection. Since our sophisticated inspection technique and systems are essential for the inspection of steam turbine blade roots that require high reliability, we intend to develop new technology and improve phased array technique based on the wide and much experience for the inspection of turbine components.

Stability characteristics of a single-phase free convection loop

Science.gov (United States)

Creveling, H. F.; De Paz, J. F.; Baladi, J. Y.; Schoenhals, R. J.

1975-01-01

Experiments investigating the stability characteristics of a single-phase free convection loop are reported. Results of the study confirm the contention made by previous workers that instabilities near the thermodynamic critical point can occur for ordinary fluids as well as those with unusual behavior in the near-critical region. Such a claim runs counter to traditional beliefs, but it is supported by the observation of such instabilities for water at atmospheric pressure and moderate temperatures in the present work.

Well-posedness and stability characteristics of multi-phase models

International Nuclear Information System (INIS)

Ransom, V.H.; Trapp, J.A.

1984-01-01

The ill-posed characteristic associated with the basic two-fluid model for multi-phase flow is a natural consequence of the idealized physical model and the mean flow modeling approach. Two approaches are discussed whereby including added physics of the flow results in a well-posed system of partial differential equations. These models offer the possibility of improved accuracy and numerical efficiency compared to the numerical models used in the existing light water reactor safety analysis codes

A facility for liquid-phase radiation experiments on heavy ion beams

Energy Technology Data Exchange (ETDEWEB)

Stuglik, Z; Zvara, I; Yakushev, A B; Timokhin, S N [Flerov Lab. of Nuclear Reactions, Dubna (Russian Federation). Joint Inst. for Nuclear Research

1994-05-01

The facility for liquid-phase radiation experiments installed on the beam line of the U-400 cyclotron in the Flerov Laboratory of Nuclear Reactions, JINR, Dubna, is described. The accelerator provides intermediate energy (some 10 MeV/nucleon) beams of ions ranging from Li to Xe. Preliminary results on the radiolysis of the Fricke solution and malachite green in ethanol by {sup 11}B, {sup 24}Mg and {sup 40}Ca ions are presented. (author).

Scintillation characteristics of phosphich-detector for detection of beta- and gamma-radiations

CERN Document Server

Ananenko, A A; Gavrilyuk, V

2002-01-01

The results of the study on the influence of individual peculiarities of the compound scintillation detector structure on the value and stability of the light yield by the gamma- and beta-radiation combined registration are presented. The phosphich detector is manufactured from the sodium iodide monocrystal, activated by thallium, and the scintillation plastic on the polystyrol basis. The comparison of the experimental results with the mathematical modeling data revealed certain regularities of the process of forming the phosphich detector light signal. The recommendations are worked out by means whereof the following characteristics of the scintillation unit: the light yield and its stability, amplitude resolution and the peak-to-valley ratio by the gamma- and beta-radiation registration were improved

Fabrication of radiation detector using PbI{sub 2} crystal

Energy Technology Data Exchange (ETDEWEB)

Shoji, T; Sakamoto, K; Ohba, K; Suehiro, T; Hiratate, Y [Tohoku Inst. of Tech., Sendai (Japan)

1996-07-01

In this paper, we will discuss the PbI{sub 2} radiation detector fabricated from a crystal grown by the zone melting method and by the vapor phase method, together with characteristics of the crystal obtained by a XPS analyzer. (J.P.N.)

A systematic methodology review of phase I radiation dose escalation trials

International Nuclear Information System (INIS)

Pijls-Johannesma, Madelon; Mastrigt, Ghislaine van; Hahn, Steve M.; De Ruysscher, Dirk; Baumert, Brigitta G.; Lammering, Guido; Buijsen, Jeroen; Bentzen, Soren M.; Lievens, Yolande; Kramar, Andrew; Lambin, Philippe

2010-01-01

Background and purpose: The purpose of this review is to evaluate the methodology used in published phase I radiotherapy (RT) dose escalation trials. A specific emphasis was placed on the frequency of reporting late complications as endpoint. Materials and methods: We performed a systematic literature review using a predefined search strategy to identify all phase I trials reporting on external radiotherapy dose escalation in cancer patients. Results: Fifty-three trials (phase I: n = 36, phase I-II: n = 17) fulfilled the inclusion criteria. Of these, 20 used a modified Fibonacci design for the RT dose escalation, but 32 did not specify a design. Late toxicity was variously defined as >3 months (n = 43) or > 6 months (n = 3) after RT, or not defined (n = 7). In only nine studies the maximum tolerated dose (MTD) was related to late toxicity, while only half the studies reported the minimum follow-up period for dose escalation (n = 26). Conclusion: In phase I RT trials, late complications are often not taken into account and there is currently no consensus on the methodology used for radiation dose escalation studies. We therefore propose a decision-tree algorithm which depends on the endpoint selected and whether a validated early surrogate endpoint is available, in order to choose the most appropriate study design.

Two-dimensional characteristic polynomials in the direct calculation of optical phase sum and difference

International Nuclear Information System (INIS)

Miranda, M; Dorrio, B V; Blanco, J; Diz-Bugarin, J; Ribas, F

2011-01-01

Two-stage phase shifting algorithms make possible to directly recover the sum or the difference of the encoded optical phase of two different fringe patterns. These algorithms can be constructed, for example, by combining known phase shifting algorithms in a non-linear way. In this work two-stage phase shifting algorithms are linked to a two-dimensional characteristic polynomial to qualitatively analyse their behaviour against the main systematic error sources in an analysis protocol like that used for phase shifting algorithms. This tool enables us to understand the propagation of properties from precursor phase shifting algorithms to new evaluation algorithms that can be built from them.

Spectral and directional radiation characteristics of thin-film coated isothermal semitransparent plates

Energy Technology Data Exchange (ETDEWEB)

Taylor, R P; Viskanta, R

1975-01-01

An analysis is presented for predicting the effective spectral directional radiation characteristics of an isothermal, semitransparent sheet surrounded on both sides by massive dielectrics. The sheet can be coated with an optically thin film and used as selective cover plates for solar collectors. Directional and polarization effects and the spectral transmittance and reflectance are considered. Sample results for candidate materials are presented.

Thermosetting materials of the radiation-modified polymer compositions. 3. Development of thermoplastic thermosetting materials from polymeric blends

International Nuclear Information System (INIS)

Kalkis, V.; Zicans, J.; Bocoka, T.; Ivanova, T.

2000-01-01

Experimental studies of blends consisting of chemically and radiation modified polyethylene and ethylene-propylene-diene copolymers have been carried out. Measurements of crystallinity, toughness, viscoelastic, adhesion and thermorelaxation properties as well as scanning electron-microscopic studies have shown that the blends chemically vulcanized by elastomer phase crosslinking system possess a typical double-phase structure within the whole composition range and characteristics specific for rubber, whereas, in radiation-vulcanized blends where crosslinking of both disperse phases takes part, formation of chemical bonds between these phases was observed. Consequently, the radiation treatment improves the properties of the blends, and materials formed by such a system can be successfully used, e.g., as elastic and adhesion active thermosetting materials if the polymer is previously oriented. (author)

Simulating the spectrum and the polarization characteristics of coherent radiation from ultrarelativistic electrons in a diamond crystal

International Nuclear Information System (INIS)

Truten', V.I.

2000-01-01

On the basis of a computer simulation, it is shown that, in the spectrum of radiation from ultrarelativistic electrons in oriented crystals, new maxima can appear in the low-frequency region in addition to ordinary coherent maxima. This effect is due to the influence of high-index planes on the radiation in question. The aforementioned new maxima manifest themselves not only in the spectrum but also in the polarization characteristics of the radiation

[Biological characteristics of the egg phase of citrus root weevils].

Science.gov (United States)

Guedes, Jerson V C; Parra, José R P

2007-01-01

The goal of this work was to study some characteristics of the egg phase of three species of citrus root weevils. The insects were collected from citrus plants in Itapetininga, SP, and brought to the Laboratório de Biologia de Insetos of ESALQ/USP, in Piracicaba, SP, where the species Naupactus cervinus (Boheman), Naupactus versatilis (Hustache) and Parapantomorus fluctuosus (Boheman) were kept. Duration and viability of the egg phase were evaluated, and the lower temperature threshold and thermal constant (K) were calculated for these species. The species of citrus root weevils showed different duration of egg phases. The egg phase ranged from 40.4 to 13.8 N. cervinus, from 38.7 to 20.0 days for N. versatilis, and from 35.0 to 13.8 days for P. fluctuosus, depending upon temperature. The temperature thresholds of this stage were 8.1, 8.3, and 9.9 masculineC at thermal constant was 385.7, 397.7 and 294.1 degree-days, for N. cervinus, N. versatilis and P. fluctuosus respectively. The duration of the egg phases of N. cervinus and N. versatilis were similar at the same temperatures and P. fluctuosus had a faster development than Naupactus spp. in all temperatures tested.

Thermal characteristics of shape-stabilized phase change material wallboard with periodical outside temperature waves

International Nuclear Information System (INIS)

Zhou, Guobing; Yang, Yongping; Wang, Xin; Cheng, Jinming

2010-01-01

Thermal characteristics of shape-stabilized phase change material (SSPCM) wallboard with sinusoidal temperature wave on the outer surface were investigated numerically and compared with traditional building materials such as brick, foam concrete and expanded polystyrene (EPS). One-dimensional enthalpy equation under convective boundary conditions was solved using fully implicit finite-difference scheme. The simulation results showed that the SSPCM wallboard presents distinct characteristics from other ordinary building materials. Phase transition keeping time of inner surface and decrement factor were applied to analyze the effects of PCM thermophysical properties (melting temperature, heat of fusion, phase transition zone and thermal conductivity), inner surface convective heat transfer coefficient and thickness of SSPCM wallboard. It was found that melting temperature is one important factor which influences both the phase transition keeping time and the decrement factor; for a certain outside temperature wave, there exist critical values of latent heat of fusion and thickness of SSPCM above which the phase transition keeping time or the decrement factor are scarcely influenced; thermal conductivity of PCM and inner surface convective coefficient have little effect on the phase transition keeping time but significantly influence the decrement factor; and the phase transition zone leads to small fluctuations of the original flat segment of inner surface temperature line. The results aim to be useful for the selection of SSPCMs and their applications in passive solar buildings.

A radiation analysis of lunar surface habitats

International Nuclear Information System (INIS)

De Angelis, G.; Wilson, J.W.; Tripathi, R.K.; Clowdsley, M.S.; Nealy, J.E.

2003-01-01

An analysis is performed on the radiation environment found on the surface of the Moon, and applied to different possible lunar base mission scenarios. An optimization technique has been used to minimize the astronaut radiation exposure and at the same time control the effect of shielding, in terms of mass addition and material choice, as a mission cost driver. The optimization process performs minimization of mass along all phases of a mission scenario, considered in terms of time frame, equipment, location, crew characteristics and performance required, radiation exposure annual and career limit constraints (those proposed in NCRP 132), and implementation of the ALARA principle. In the lunar environment manned habitats are to host future crews involved in the construction and/or in the utilization of moon based infrastructure. Three different kinds of lunar missions are considered in the analysis, Moon Base Construction Phase, during which astronauts are on the surface just to build an outpost for future resident crews, Moon Base Outpost Phase, during which astronaut crews are resident but continuing exploration and installation activities, and Moon Base Routine Phase, with shifting resident crews. In each scenario various kinds of habitats, from very simple shelters to more complex bases, are considered in detail (e.g. shape, thickness, materials, etc) with considerations of various shielding strategies. The results for all scenarios clearly showed that the direct exposure to the space environment like in transfers and EVAs phases gives the most of the dose, with the proposed shielded habitats and shelters giving quite a good protection from radiation. Operational constraints on hardware and scenarios have all been considered by the optimization techniques. Within the limits of this preliminary analysis, the three Moon Base related mission scenarios are perfectly feasible from the astronaut radiation safety point of view with the currently adopted and proposed

Dynamic phasing of multichannel cw laser radiation by means of a stochastic gradient algorithm

Energy Technology Data Exchange (ETDEWEB)

Volkov, V A; Volkov, M V; Garanin, S G; Dolgopolov, Yu V; Kopalkin, A V; Kulikov, S M; Starikov, F A; Sukharev, S A; Tyutin, S V; Khokhlov, S V; Chaparin, D A [Russian Federal Nuclear Center ' All-Russian Research Institute of Experimental Physics' , Sarov, Nizhnii Novgorod region (Russian Federation)

2013-09-30

The phasing of a multichannel laser beam by means of an iterative stochastic parallel gradient (SPG) algorithm has been numerically and experimentally investigated. The operation of the SPG algorithm is simulated, the acceptable range of amplitudes of probe phase shifts is found, and the algorithm parameters at which the desired Strehl number can be obtained with a minimum number of iterations are determined. An experimental bench with phase modulators based on lithium niobate, which are controlled by a multichannel electronic unit with a real-time microcontroller, has been designed. Phasing of 16 cw laser beams at a system response bandwidth of 3.7 kHz and phase thermal distortions in a frequency band of about 10 Hz is experimentally demonstrated. The experimental data are in complete agreement with the calculation results. (control of laser radiation parameters)

Radiating Elements for Shared Aperture Tx/Rx Phased Arrays at K/Ka Band

KAUST Repository

Sandhu, Ali Imran; Arnieri, E.; Amendola, Giandomenico; Boccia, L.; Meniconi, Erika; Ziegler, Volker

2016-01-01

A dual band, Tx/Rx, self-diplexing phased array is presented. The antenna has been designed to cover Tx/Rx satellite communications at K/Ka band with a frequency ratio 1.5:1. To obtain dual band operations with a single radiating surface, a novel dual band radiator is adopted and placed in a configuration in which dual band and single band elements are interleaved. The proposed configuration reduces the number of radiating elements required by other solutions while avoiding the insurgence of grating lobes. The tightly packed arrangement of the elements poses many integration issues, which are solved with a novel integration technique. The array elements are optimized to scan the beam in excess of ° in both bands. A subarray with 49 Rx elements and 105 Tx elements was built and measured confirming the results obtained in simulations.

Radiating Elements for Shared Aperture Tx/Rx Phased Arrays at K/Ka Band

KAUST Repository

Sandhu, Ali Imran

2016-04-11

A dual band, Tx/Rx, self-diplexing phased array is presented. The antenna has been designed to cover Tx/Rx satellite communications at K/Ka band with a frequency ratio 1.5:1. To obtain dual band operations with a single radiating surface, a novel dual band radiator is adopted and placed in a configuration in which dual band and single band elements are interleaved. The proposed configuration reduces the number of radiating elements required by other solutions while avoiding the insurgence of grating lobes. The tightly packed arrangement of the elements poses many integration issues, which are solved with a novel integration technique. The array elements are optimized to scan the beam in excess of ° in both bands. A subarray with 49 Rx elements and 105 Tx elements was built and measured confirming the results obtained in simulations.

Fiber-optic-coupled dosemeter for remote optical sensing of radiation

International Nuclear Information System (INIS)

Justus, B.L.; Huston, A.L.

1996-01-01

Remote sensing technologies for the detection and measurement of ionizing radiation exposure are of current interest for applications such as patient dose verification during radiotherapy and the monitoring of environmental contaminants. Fiberoptic-based sensing is attractive due to the advantages of small size, low cost, long life and freedom from electromagnetic interference. Several fiberoptic-based radiation sensing systems have been described that utilize radiation induced changes in the optical characteristics of the fiber such as reduced transmission as a result of darkening of the glass, optical phase shifts due to heating, or changes in the birefringence of a polarization-maintaining fiber. The measurement of radiation induced darkening is limited in both sensitivity and dynamic range and requires long fiber lengths. Phase shift measurements require the use of single-mode lasers, phase sensitive interferometric detection, long fiber lengths and complex signal processing techniques. Alternatively, thermoluminescent (TL) phosphor powders have been coated onto fiberoptic cables and remote dosimetry measurements performed using traditional laser heating techniques. The sensitivity is limited by the requirement for a very thin layer of phosphor material, due to problems associated with light scattering and efficient heating by thermal diffusion. In this paper we report the development of an all-optical, fiber-optic-coupled, thermoluminescence dosemeter for remote radiation sensing that offers significant advantages compared to previous technologies. We recently reported the development of an optically transparent, TL glass material having exceptionally good characteristics for traditional dosimetry applications. We also reported a modified TL glass incorporating a rare earth ion dopant in order to absorb light from a semiconductor laser and utilize the absorbed light energy to internally heat the glass and release the trapped electrons. (author)

In-Space technology experiments program. A high efficiency thermal interface (using condensation heat transfer) between a 2-phase fluid loop and heatpipe radiator: Experiment definition phase

Science.gov (United States)

Pohner, John A.; Dempsey, Brian P.; Herold, Leroy M.

1990-01-01

Space Station elements and advanced military spacecraft will require rejection of tens of kilowatts of waste heat. Large space radiators and two-phase heat transport loops will be required. To minimize radiator size and weight, it is critical to minimize the temperature drop between the heat source and sink. Under an Air Force contract, a unique, high-performance heat exchanger is developed for coupling the radiator to the transport loop. Since fluid flow through the heat exchanger is driven by capillary forces which are easily dominated by gravity forces in ground testing, it is necessary to perform microgravity thermal testing to verify the design. This contract consists of an experiment definition phase leading to a preliminary design and cost estimate for a shuttle-based flight experiment of this heat exchanger design. This program will utilize modified hardware from a ground test program for the heat exchanger.

Statistical parameter characteristics of gas-phase fluctuations for gas-liquid intermittent flow

Energy Technology Data Exchange (ETDEWEB)

Matsui, G.; Monji, H.; Takaguchi, M. [Univ. of Tsukuba (Japan)

1995-09-01

This study deals with theoretical analysis on the general behaviour of statistical parameters of gas-phase fluctuations and comparison of statistical parameter characteristics for the real void fraction fluctuations measured with those for the wave form modified the real fluctuations. In order to investigate the details of the relation between the behavior of the statistical parameters in real intermittent flow and analytical results obtained from information on the real flow, the distributions of statistical parameters for general fundamental wave form of gas-phase fluctuations are discussed in detail. By modifying the real gas-phase fluctuations to a trapezoidaly wave, the experimental results can be directly compared with the analytical results. The analytical results for intermittent flow show that the wave form parameter, and the total amplitude of void fraction fluctuations, affects strongly on the statistical parameter characteristics. The comparison with experiment using nitrogen gas-water intermittent flow suggests that the parameters of skewness and excess may be better as indicators of flow pattern. That is, the macroscopic nature of intermittent flow can be grasped by the skewness and the excess, and the detailed flow structure may be described by the mean and the standard deviation.

Statistical parameter characteristics of gas-phase fluctuations for gas-liquid intermittent flow

International Nuclear Information System (INIS)

Matsui, G.; Monji, H.; Takaguchi, M.

1995-01-01

This study deals with theoretical analysis on the general behaviour of statistical parameters of gas-phase fluctuations and comparison of statistical parameter characteristics for the real void fraction fluctuations measured with those for the wave form modified the real fluctuations. In order to investigate the details of the relation between the behavior of the statistical parameters in real intermittent flow and analytical results obtained from information on the real flow, the distributions of statistical parameters for general fundamental wave form of gas-phase fluctuations are discussed in detail. By modifying the real gas-phase fluctuations to a trapezoidaly wave, the experimental results can be directly compared with the analytical results. The analytical results for intermittent flow show that the wave form parameter, and the total amplitude of void fraction fluctuations, affects strongly on the statistical parameter characteristics. The comparison with experiment using nitrogen gas-water intermittent flow suggests that the parameters of skewness and excess may be better as indicators of flow pattern. That is, the macroscopic nature of intermittent flow can be grasped by the skewness and the excess, and the detailed flow structure may be described by the mean and the standard deviation

Determination of the onset nonlinearity hydrodynamic characteristics at two-phase flow in parallel vertical channels

International Nuclear Information System (INIS)

Jovic, V.; Afgan, N.; Jovic, L.; Spasojevic, D.

1993-01-01

The paper presents results of the experimental and theoretical analyses of linear and nonlinear characteristics of adiabatic two-phase water-air flow in vertical parallel channels. Regime character changes and linear to nonlinear dynamic characteristics transfer conditions were defined. (author)

Quantification of susceptibility change at high-concentrated SPIO-labeled target by characteristic phase gradient recognition.

Science.gov (United States)

Zhu, Haitao; Nie, Binbin; Liu, Hua; Guo, Hua; Demachi, Kazuyuki; Sekino, Masaki; Shan, Baoci

2016-05-01

Phase map cross-correlation detection and quantification may produce highlighted signal at superparamagnetic iron oxide nanoparticles, and distinguish them from other hypointensities. The method may quantify susceptibility change by performing least squares analysis between a theoretically generated magnetic field template and an experimentally scanned phase image. Because characteristic phase recognition requires the removal of phase wrap and phase background, additional steps of phase unwrapping and filtering may increase the chance of computing error and enlarge the inconsistence among algorithms. To solve problem, phase gradient cross-correlation and quantification method is developed by recognizing characteristic phase gradient pattern instead of phase image because phase gradient operation inherently includes unwrapping and filtering functions. However, few studies have mentioned the detectable limit of currently used phase gradient calculation algorithms. The limit may lead to an underestimation of large magnetic susceptibility change caused by high-concentrated iron accumulation. In this study, mathematical derivation points out the value of maximum detectable phase gradient calculated by differential chain algorithm in both spatial and Fourier domain. To break through the limit, a modified quantification method is proposed by using unwrapped forward differentiation for phase gradient generation. The method enlarges the detectable range of phase gradient measurement and avoids the underestimation of magnetic susceptibility. Simulation and phantom experiments were used to quantitatively compare different methods. In vivo application performs MRI scanning on nude mice implanted by iron-labeled human cancer cells. Results validate the limit of detectable phase gradient and the consequent susceptibility underestimation. Results also demonstrate the advantage of unwrapped forward differentiation compared with differential chain algorithms for susceptibility

Investigation of characteristics and radiation hardness of the Beetle 1.0 front-end chip

CERN Document Server

Van Bakel, N; Jans, E; Klous, S; Verkooijen, H

2001-01-01

Noise characteristics of the Beetle 1.0 front-end chip have been investigated as a function of input capacitance. Values for the equivalent noise charge and ballastic deficit have been extracted. Amplification and pulse shape have been studied by varying the bias settings over a wide range. Results are compared with simulations that include realistic impedances at the input and output. The chip has been subjected to 10 Mrad of radiation. Subsequently, its behaviour is measured again and compared to that preceeding the irradiation. Observed radiation damage effects are discussed.

Heat transfer characteristics of coconut oil as phase change material to room cooling application

Science.gov (United States)

Irsyad, M.; Harmen

2017-03-01

Thermal comfort in a room is one of human needs in the workplace and dwellings, so that the use of air conditioning system in tropical countries is inevitable. This equipment has an impact on the increase of energy consumption. One method of minimizing the energy use is by using the phase change material (PCM) as thermal energy storage. This material utilizes the temperature difference between day and night for the storage and release of thermal energy. PCM development on application as a material for air cooling inlet, partitioning and interior needs to be supported by the study of heat transfer characteristics when PCM absorbs heat from ambient temperature. This study was conducted to determine the heat transfer characteristics on coconut oil as a phase change material. There are three models of experiments performed in this research. Firstly, an experiment was conducted to analyze the time that was needed by material to phase change by varying the temperature. The second experiment analyzed the heat transfer characteristics of air to PCM naturally convection. The third experiment analyzed the forced convection heat transfer on the surface of the PCM container by varying the air velocity. The data of experimental showed that, increasing ambient air temperature resulted in shorter time for phase change. At temperatures of 30°C, the time for phase change of PCM with the thickness of 8 cm was 1700 min, and it was stable at temperatures of 27°C. Increasing air temperature accelerated the phase change in the material. While for the forced convection heat transfer, PCM could reduce the air temperature in the range of 30 to 35°C at about 1 to 2°C, with a velocity of 1-3 m/s.

The characteristics of corrosion, radiation degradation and dissolution of titanium alloys

International Nuclear Information System (INIS)

Sung, K. W.; Na, J. W.; Choi, B. S.; Lee, D. J.; Chang, M. H.

2001-12-01

In order to establish the technical bases of water chemistry design requirement related titanium alloys, we investigated the characteristics of corrosion, activation, radiation degradation, radiation hydrogen embrittlement of titanium alloys and dissolution of titanium dioxide. Titanium alloys generally have high corrosion resistance. Corrosion product release from PT-7M and PT-3V titanium alloy surface for 18 months of operation is negligible, and the corrosion penetration for about 30 years is about 1 μm, while the corrosion rates is not higher than one third of that of austenitic steel. Titanium only converts into Sc-46 with 85 day halflife after neutron irradiation, and its radioactivity is not higher than one thousandth of that produced from nickel. Therefore, under the condition without any neutron irradiation, the radiation damage of titanium alloys would have no problem. Titanium dioxide, that protects the metals from the corrosion, has retrograde solubility in neutral solutions. It does not form any complexes with ligands such as ammonia, but Ti(IV) gets more stable by complexing with water molecules. In conclusion, it is estimated that titanium alloys such as PT-7M would be applicable to steam generator materials

Numerical study on the influence of aluminum on infrared radiation signature of exhaust plume

Science.gov (United States)

Zhang, Wei; Ye, Qing-qing; Li, Shi-peng; Wang, Ning-fei

2013-09-01

The infrared radiation signature of exhaust plume from solid propellant rockets has been widely mentioned for its important realistic meaning. The content of aluminum powder in the propellants is a key factor that affects the infrared radiation signature of the plume. The related studies are mostly on the conical nozzles. In this paper, the influence of aluminum on the flow field of plume, temperature distribution, and the infrared radiation characteristics were numerically studied with an object of 3D quadrate nozzle. Firstly, the gas phase flow field and gas-solid multi phase flow filed of the exhaust plume were calculated using CFD method. The result indicates that the Al203 particles have significant effect on the flow field of plume. Secondly, the radiation transfer equation was solved by using a discrete coordinate method. The spectral radiation intensity from 1000-2400 cm-1 was obtained. To study the infrared radiation characteristics of exhaust plume, an exceptional quadrate nozzle was employed and much attention was paid to the influences of Al203 particles in solid propellants. The results could dedicate the design of the divert control motor in such hypervelocity interceptors or missiles, or be of certain meaning to the improvement of ingredients of solid propellants.

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

Science.gov (United States)

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

Effect of thermal radiation on magnetohydrodynamics nanofluid flow and heat transfer by means of two phase model

International Nuclear Information System (INIS)

Sheikholeslami, Mohsen; Domiri Ganji, Davood; Younus Javed, M.; Ellahi, R.

2015-01-01

In this study, effect of thermal radiation on magnetohydrodynamics nanofluid flow between two horizontal rotating plates is studied. The significant effects of Brownian motion and thermophoresis have been included in the model of nanofluid. By using the appropriate transformation for the velocity, temperature and concentration, the basic equations governing the flow, heat and mass transfer are reduced to a set of ordinary differential equations. These equations, subjected to the associated boundary conditions are solved numerically using the fourth-order Runge–Kutta method. The effects of Reynolds number, magnetic parameter, rotation parameter, Schmidt number, thermophoretic parameter, Brownian parameter and radiation parameter on heat and mass characteristics are examined. Results show that Nusselt number has direct relationship with radiation parameter and Reynolds number while it has reverse relationship with other active parameters. It can also be found that concentration boundary layer thickness decreases with the increase of radiation parameter. - Highlights: • This paper analyses thermal radiation on magnetohydrodynamic nanofluid. • Fourth-order Runge–Kutta method is used. • The effects of Reynolds number, magnetic parameter, rotation parameter, Schmidt number thermophoretic parameter, Brownian parameter and radiation parameter on heat and mass characteristics are examined. • Comparison is also made with the existing literature

Effect of the ionizing radiation in the sensorial characteristics of the pineapple

International Nuclear Information System (INIS)

Silva, Josenilda Maria da; Spoto, Marta Helena Fillet; Silva, Juliana Pizarro

2007-01-01

The post-harvest quality of the pineapple cultivar Smooth Cayenne was evaluated after the fruit was irradiated with doses of 100 and 150 Gy and stored for 10, 20 and 30 days at 12 deg C ( +-1) and relative humidity of 85% (+- 5). The controls were untreated fruits. Sensorial analyses were made for each storage period to obtain information about the effects of ionizing radiation on the quality of the fruit. The ionizing radiation dosage had little effect on the sensorial characteristics of the pineapple, although the best results were obtained with fruit irradiated with 100 Gy. The 20-day storage period resulted in the highest consumer acceptability, while the 30-day storage period impaired the fruit's external and internal appearance. (author)

Heat transfer characteristics of the two-phase closed thermosyphon (wickless heat pipe)

International Nuclear Information System (INIS)

Andros, F.E.; Florschuetz, L.W.

1982-01-01

Steady-state heat transfer characteristics and heat transfer limits (dry-out) for a vertical stainless steel tubular two-phase closed thermosyphon with Freon-113 working fluid are reported as a function of certain geometric parameters and liquid fill quantity. Condenser section heat transfer characteristics agreed reasonably well with existing laminar film condensation correlations and were found to be independent of the evaporator section, except for larger liquid fills. Evaporator characteristics were quite complex and appeared, under some conditions, to be coupled to condenser characteristics through effects of system pressure and/or surface wave as present on the descending condensate film. A laminar thin film evaporation model was found to give reasonable agreement with local evaporator temperature measurements in those regions of the evaporator where a continuous film apparently persisted. The measured heat transfer characteristics are interpreted relative to an earlier investigation by the authors in which flow characteristics in a similar device were visually and photographically observed. 10 references

Thermal Vacuum Test of Ice as a Phase Change Material Integrated with a Radiator

Science.gov (United States)

Lee, Steve A.; Leimkuehler, Thomas O.; Stephan, Ryan; Le, Hung V.

2010-01-01

Water may be used as radiation shielding for Solar Particle Events (SPE) to protect crewmembers in the Lunar Electric Rover (LER). Because the water is already present for radiation protection, it could also provide a mass efficient solution to the vehicle's thermal control system. This water can be frozen by heat rejection from a radiator and used as a Phase Change Material (PC1V1) for thermal storage. Use of this water as a PCM can eliminate the need for a pumped fluid loop thermal control system as well as reduce the required size of the radiator. This paper describes the testing and analysis performed for the Rover Engineering Development Unit (REDU), a scaled-down version of a water PCM heat sink for the LER. The REDU was tested in a thermal-vacuum chamber at environmental temperatures similar to those of a horizontal radiator panel on the lunar surface. Testing included complete freeze and melt cycles along with scaled transient heat load profiles simulating a 24-hour day for the rover.

Dynamic characteristics of far-field radiation of current modulated phase-locked diode laser arrays

Science.gov (United States)

Elliott, R. A.; Hartnett, K.

1987-01-01

A versatile and powerful streak camera/frame grabber system for studying the evolution of the near and far field radiation patterns of diode lasers was assembled and tested. Software needed to analyze and display the data acquired with the steak camera/frame grabber system was written and the total package used to record and perform preliminary analyses on the behavior of two types of laser, a ten emitter gain guided array and a flared waveguide Y-coupled array. Examples of the information which can be gathered with this system are presented.

Investigating the effect of K-characteristic radiation on the performance of nuclear medicine scintillators by Monte Carlo methods

International Nuclear Information System (INIS)

Liaparinos, Panagiotis; Kandarakis, Ioannis; Cavouras, Dionisis; Delis, Harry; Panayiotakis, George

2006-01-01

The aim of this study was to evaluate the effect of K-characteristic radiation on the performance of scintillator crystals incorporated in nuclear medicine detectors (LSO, BGO, GSO). K-characteristic radiation is produced within materials of at least one high atomic number element (e.g. Lu, Gd, Bi). This radiation may either be reabsorbed or it may escape the scintillator. In both cases the light emission efficiency of the scintillator may be affected resulting in either spatial or energy resolution degradation. A computational program, based on Monte Carlo methods, was developed in order to simulate the transport of K-characteristic radiation within the most commonly used scintillator materials. Crystal thickness was allowed to vary from 0.5 up to 15 mm. A monoenergetic pencil beam, with energy varying from 0.60 to 0.511 MeV was considered to fall on the center of the crystal surface. The dominant γ-ray interactions (elastic and inelastic scattering and photoelectric absorption) were taken into account in the simulation. Results showed that, depending on crystal thickness, incident photon energy and scintillator's intrinsic properties (L or K-fluorescence yield, effective atomic number and density), the scintillator's emission efficiency may be significantly reduced and affect spatial or energy resolution

Differences in inhibition by beta-arabinofuranosyladenine (araA) of radiation induced DNA damage repair in exponentially growing and plateau-phase CHO-cells

International Nuclear Information System (INIS)

Iliakis, G.; Seaner, R.

1988-01-01

The effect of beta-arabinofuranosyladenine (araA) on the repair of radiation induced DNA damage, as measured by the DNA unwinding technique, was studied in exponentially growing and plateau-phase CHO-cells after exposure to X-rays. Induction of DNA damage by radiation was found to be similar in exponentially growing and plateau-phase cells. In the absence of araA, repair of radiation induced DNA damage proceeded with similar kinetics in exponentially growing and plateau-phase cells. AraA at concentrations between 0-1500 μM inhibited DNA repair both in exponentially growing and in plateau-phase cells. However, the degree of inhibition was significantly higher (by a factor of 3) in plateau-phase cells. A similar degree of repair inhibition by araA was observed in plateau-phase cells treated in their conditioned medium, as well as in plateau-phase cells that were transferred in fresh growth medium just before treatment initiation. These results indicate the importance of biochemical parameters associated with alterations in the growth state of the cells for the inhibitory effect of araA and may help in the elucidation of the molecular mechanism(s) underlying repair inhibition by inhibitors of DNA replication. (orig.)

Characteristics for heavy ions and micro-dosimetry in radiation detectors

International Nuclear Information System (INIS)

Doke, Tadayoshi

1978-01-01

The characteristics of radiation detectors for heavy ions generally present more complex aspects as compared with those for electron beam and γ-ray. There is the ''Katz theory'' applying the target theory in radiobiology phenomenologically to radiation detectors. Here, first, the Katz theory for radiation detectors is explained, then its applications to nuclear plates, solid state track detectors, scintillation detectors and thermoluminescence dosimeters are described, respectively. The theory is used for the calibration of the nuclear charge of heavy ions in nuclear plates and recently is used to simulate the flight tracks of heavy ions or magnetic monopoles. In solid state track detectors, the threshold value of the energy given along the tracks of heavy ions is inherent to a detector, and the Katz theory is applicable as the measure of the threshold. The theory seems to be superior to the other methods. However, it has disadvantages that the calculation is not simple and is difficult for wide objects. In scintillation detectors, the scintillation efficiency is not a single function of dE/dx, but depends on the kinds of heavy ions, which Katz succeeded to describe quantitatively with his theory. Such result has also been produced that the dependence of thermoluminescence dosimeters such as LiF on LET by Katz theory agreed fairly well with experiments. (Wakatsuki, Y.)

Synchrotron radiation phase-contrast X-ray CT imaging of acupuncture points

Energy Technology Data Exchange (ETDEWEB)

Zhang, Dongming; Yan, Xiaohui; Zhang, Xinyi [Fudan University, Synchrotron Radiation Research Center, State Key Laboratory of Surface Physics and Department of Physics, Shanghai (China); Liu, Chenglin [Physics Department of Yancheng Teachers' College, Yancheng (China); Dang, Ruishan [The Second Military Medical University, Shanghai (China); Xiao, Tiqiao [Chinese Academy of Sciences, Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Shanghai (China); Zhu, Peiping [Chinese Academy of Sciences, Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Beijing (China)

2011-08-15

Three-dimensional (3D) topographic structures of acupuncture points were investigated by using synchrotron radiation in-line X-ray phase contrast computerized tomography. Two acupuncture points, named Zhongji (RN3) and Zusanli (ST36), were studied. We found an accumulation of microvessels at each acupuncture point region. Images of the tissues surrounding the acupuncture points do not show such kinds of structure. This is the first time that 3D images have revealed the specific structures of acupuncture points. (orig.)

Synchrotron radiation phase-contrast X-ray CT imaging of acupuncture points

International Nuclear Information System (INIS)

Zhang, Dongming; Yan, Xiaohui; Zhang, Xinyi; Liu, Chenglin; Dang, Ruishan; Xiao, Tiqiao; Zhu, Peiping

2011-01-01

Three-dimensional (3D) topographic structures of acupuncture points were investigated by using synchrotron radiation in-line X-ray phase contrast computerized tomography. Two acupuncture points, named Zhongji (RN3) and Zusanli (ST36), were studied. We found an accumulation of microvessels at each acupuncture point region. Images of the tissues surrounding the acupuncture points do not show such kinds of structure. This is the first time that 3D images have revealed the specific structures of acupuncture points. (orig.)

A case of radiation sigmoiditis diagnosed by a characteristic pathological finding

International Nuclear Information System (INIS)

Kamata, Noriko; Oshitani, Nobuhide; Oiso, Ryuta

2002-01-01

A 65-year-old woman was referred to our hospital because of an intractable sigmoid colon ulcer. She had undergone a right nephrectomy for kidney stones, at age 33, and a uterectomy at age 39, followed by radiation therapy. Lower abdominal pain and hematochezia developed suddenly, following a few days of constipation, in September 1999, when she was admitted to the previous hospital because of left hydronephrosis. A punched-out oval ulcer was found in the sigmoid colon, on colonoscopic examination. She was treated with total parenteral nutrition, prednisolone, and mesalazine administration. Although her hematochezia and abdominal pain disappeared, diarrhea and abdominal pain occurred after she began eating, and she was referred to our hospital for further examination. Although intestinal lavage solution was used for bowel preparation, stercoromas were found in the rectum, which had to be manually removed before colonoscopic examination, and a stercoral-ulcer was suspected. The sigmoid colonic ulcer was intractable. A biopsy specimen, taken from the bottom of the ulcer, revealed bizarre interstitial cells, each with a large oval nucleus, showing the so-called ''owl-eye-appearance.'' Although the diagnosis of radiation sigmoiditis is sometimes difficult, owl-eye-appearance'' is a useful pathological finding in the diagnosis of late-phase radiation-induced colitis. (author)

A case of radiation sigmoiditis diagnosed by a characteristic pathological finding

Energy Technology Data Exchange (ETDEWEB)

Kamata, Noriko; Oshitani, Nobuhide; Oiso, Ryuta [Osaka City Univ. (Japan). Graduate School of Medicine] (and others)

2002-05-01

A 65-year-old woman was referred to our hospital because of an intractable sigmoid colon ulcer. She had undergone a right nephrectomy for kidney stones, at age 33, and a uterectomy at age 39, followed by radiation therapy. Lower abdominal pain and hematochezia developed suddenly, following a few days of constipation, in September 1999, when she was admitted to the previous hospital because of left hydronephrosis. A punched-out oval ulcer was found in the sigmoid colon, on colonoscopic examination. She was treated with total parenteral nutrition, prednisolone, and mesalazine administration. Although her hematochezia and abdominal pain disappeared, diarrhea and abdominal pain occurred after she began eating, and she was referred to our hospital for further examination. Although intestinal lavage solution was used for bowel preparation, stercoromas were found in the rectum, which had to be manually removed before colonoscopic examination, and a stercoral-ulcer was suspected. The sigmoid colonic ulcer was intractable. A biopsy specimen, taken from the bottom of the ulcer, revealed bizarre interstitial cells, each with a large oval nucleus, showing the so-called ''owl-eye-appearance.'' Although the diagnosis of radiation sigmoiditis is sometimes difficult, owl-eye-appearance'' is a useful pathological finding in the diagnosis of late-phase radiation-induced colitis. (author)

Characteristics of rotating target neutron source and its use in radiation effects studies

International Nuclear Information System (INIS)

Van Konynenburg, R.A.; Barschall, H.H.; Booth, R.; Wong, C.

1975-07-01

The Rotating Target Neutron Source (RTNS) at Lawrence Livermore Laboratory is currently the most intense source of DT fusion neutrons available for the study of radiation effects in materials. This paper will present a brief description of the machine, outline the history of its development and discuss its performance characteristics and its application to CTR materials research. (U.S.)

Mechanical parameters and flight phase characteristics in aquatic plyometric jumping.

Science.gov (United States)

Louder, Talin J; Searle, Cade J; Bressel, Eadric

2016-09-01

Plyometric jumping is a commonly prescribed method of training focused on the development of reactive strength and high-velocity concentric power. Literature suggests that aquatic plyometric training may be a low-impact, effective supplement to land-based training. The purpose of the present study was to quantify acute, biomechanical characteristics of the take-off and flight phase for plyometric movements performed in the water. Kinetic force platform data from 12 young, male adults were collected for counter-movement jumps performed on land and in water at two different immersion depths. The specificity of jumps between environmental conditions was assessed using kinetic measures, temporal characteristics, and an assessment of the statistical relationship between take-off velocity and time in the air. Greater peak mechanical power was observed for jumps performed in the water, and was influenced by immersion depth. Additionally, the data suggest that, in the water, the statistical relationship between take-off velocity and time in air is quadratic. Results highlight the potential application of aquatic plyometric training as a cross-training tool for improving mechanical power and suggest that water immersion depth and fluid drag play key roles in the specificity of the take-off phase for jumping movements performed in the water.

Preparation and thermal conductivity enhancement of composite phase change materials for electronic thermal management

International Nuclear Information System (INIS)

Wu, Weixiong; Zhang, Guoqing; Ke, Xiufang; Yang, Xiaoqing; Wang, Ziyuan; Liu, Chenzhen

2015-01-01

Highlights: • A kind of composite phase change material board (PCMB) is prepared and tested. • PCMB presents a large thermal storage capacity and enhanced thermal conductivity. • PCMB displays much better cooling effect in comparison to natural air cooling. • PCMB presents different cooling characteristics in comparison to ribbed radiator. - Abstract: A kind of phase change material board (PCMB) was prepared for use in the thermal management of electronics, with paraffin and expanded graphite as the phase change material and matrix, respectively. The as-prepared PCMB presented a large thermal storage capacity of 141.74 J/g and enhanced thermal conductivity of 7.654 W/(m K). As a result, PCMB displayed much better cooling effect in comparison to natural air cooling, i.e., much lower heating rate and better uniformity of temperature distribution. On the other hand, compared with ribbed radiator technology, PCMB also presented different cooling characteristics, demonstrating that they were suitable for different practical application

Two-Phase Gas-Liquid Flow Structure Characteristics under Periodic Cross Forces Action

Directory of Open Access Journals (Sweden)

V. V. Perevezentsev

2015-01-01

Full Text Available The article presents a study of two-phase gas-liquid flow under the action of periodic cross forces. The work objective is to obtain experimental data for further analysis and have structure characteristics of the two-phase flow movement. For research, to obtain data without disturbing effect on the flow were used optic PIV (Particle Image Visualization methods because of their noninvasiveness. The cross forces influence was provided by an experimental stand design to change the angular amplitudes and the periods of channel movement cycle with two-phase flow. In the range of volume gas rates was shown a water flow rate versus the inclination angle of immovable riser section and the characteristic angular amplitudes and periods of riser section inclination cycle under periodic cross forces. Data on distribution of average water velocity in twophase flow in abovementioned cases were also obtained. These data allowed us to draw a conclusion that a velocity distribution depends on the angular amplitude and on the period of the riser section roll cycle. This article belongs to publications, which study two-phase flows with no disturbing effect on them. Obtained data give an insight into understanding a pattern of twophase gas-liquid flow under the action of periodic cross forces and can be used to verify the mathematical models of the CFD thermo-hydraulic codes. In the future, the work development expects taking measurements with more frequent interval in the ranges of angular amplitudes and periods of the channel movement cycle and create a mathematical model to show the action of periodic cross forces on two-phase gas-liquid flow.

Critical sizes and critical characteristics of nanoclusters, nanostructures and nanomaterials

International Nuclear Information System (INIS)

Suzdalev, I.P.

2005-01-01

Full text: Critical sizes and characteristics of nanoclusters and nanostructures are introduced as the parameters of nanosystems and nanomaterials. The next critical characteristics are considered: atomic and electronic 'magic number', critical size of cluster nucleation, critical size of melting-freezing of cluster, critical size of quantum (laser) radiation, critical sizes for the single electron conductivity, critical energy and magnetic field for the magnetic tunneling, critical cluster sizes for the giant magnetic resistance, critical size of the first order magnetic phase transition. The critical characteristics are estimated by thermodynamic approaches, by Moessbauer spectroscopy, AFM, heat capacity, SQUID magnetometry and other technique, The influence of cluster-cluster interactions, cluster-matrix interactions and cluster defects on cluster atomic dynamics, cluster melting, cluster critical sizes, Curie or Neel points and the character of magnetic phase transitions were investigated. The applications of critical size and critical characteristic parameters for the nanomaterial characterization are considered

Effects of ionizing radiation in the physico-chemical characteristics of red wine Cabernet Sauvignon

International Nuclear Information System (INIS)

Silva, Fellipe Souza da; Leiras, Anderson; Wagner, Walsan

2014-01-01

The oenology in the current days is increasingly aimed obtain improvements on wine quality produced without there the deterioration of characteristics of the same, using new technologies for such order. The objective of present work will be the application of the radiation ionizing in wines Cabernet Sauvignon, with the interest of analyzing its effects on physic-chemical characteristics of this wines, such as quality, aging and etc. Were analyzed the following strands: degree alcoholic; dry extract; density and absorbance with spectrometer (420, 520 and 620 nm). (author)

JCCRER Project 2.3 -- Deterministic effects of occupational exposure to radiation. Phase 1: Feasibility study; Final report

Energy Technology Data Exchange (ETDEWEB)

Okladnikova, N.; Pesternikova, V.; Sumina, M. [Inst. of Biophysics, Ozyorsk (Russian Federation)] [and others

1998-12-01

Phase 1 of Project 2.3, a short-term collaborative Feasibility Study, was funded for 12 months starting on 1 February 1996. The overall aim of the study was to determine the practical feasibility of using the dosimetric and clinical data on the MAYAK worker population to study the deterministic effects of exposure to external gamma radiation and to internal alpha radiation from inhaled plutonium. Phase 1 efforts were limited to the period of greatest worker exposure (1948--1954) and focused on collaboratively: assessing the comprehensiveness, availability, quality, and suitability of the Russian clinical and dosimetric data for the study of deterministic effects; creating an electronic data base containing complete clinical and dosimetric data on a small, representative sample of MAYAK workers; developing computer software for the testing of a currently used health risk model of hematopoietic effects; and familiarizing the US team with the Russian diagnostic criteria and techniques used in the identification of Chronic Radiation Sickness.

JCCRER Project 2.3 - Deterministic effects of occupational exposure to radiation. Phase 1: Feasibility study. Final report

International Nuclear Information System (INIS)

Okladnikova, N.; Pesternikova, V.; Sumina, M.

1998-01-01

Phase 1 of Project 2.3, a short-term collaborative Feasibility Study, was funded for 12 months starting on 1 February 1996. The overall aim of the study was to determine the practical feasibility of using the dosimetric and clinical data on the MAYAK worker population to study the deterministic effects of exposure to external gamma radiation and to internal alpha radiation from inhaled plutonium. Phase 1 efforts were limited to the period of greatest worker exposure (1948--1954) and focused on collaboratively: assessing the comprehensiveness, availability, quality, and suitability of the Russian clinical and dosimetric data for the study of deterministic effects; creating an electronic data base containing complete clinical and dosimetric data on a small, representative sample of MAYAK workers; developing computer software for the testing of a currently used health risk model of hematopoietic effects; and familiarizing the US team with the Russian diagnostic criteria and techniques used in the identification of Chronic Radiation Sickness

A simplified edge illumination set-up for quantitative phase contrast mammography with synchrotron radiation at clinical doses

International Nuclear Information System (INIS)

Longo, Mariaconcetta; Rigon, Luigi; Lopez, Frances C M; Longo, Renata; Chen, Rongchang; Dreossi, Diego; Zanconati, Fabrizio

2015-01-01

This work presents the first study of x-ray phase contrast imaging based on a simple implementation of the edge illumination method (EIXPCi) in the field of mammography with synchrotron radiation. A simplified EIXPCi set-up was utilized to study a possible application in mammography at clinical doses. Moreover, through a novel algorithm capable of separating and quantifying absorption and phase perturbations of images acquired in EIXPCi modality, it is possible to extract quantitative information on breast images, allowing an accurate tissue identification. The study was carried out at the SYRMEP beamline of Elettra synchrotron radiation facility (Trieste, Italy), where a mastectomy specimen was investigated with the EIXPCi technique. The sample was exposed at three different energies suitable for mammography with synchrotron radiation in order to test the validity of the novel algorithm in extracting values of linear attenuation coefficients integrated over the sample thickness. It is demonstrated that the quantitative data are in good agreement with the theoretical values of linear attenuation coefficients calculated on the hypothesis of the breast with a given composition. The results are promising and encourage the current efforts to apply the method in mammography with synchrotron radiation. (note)

Importance of thermal radiation from heat sink in cooling of three phase PWM inverter kept inside an evacuated chamber

Directory of Open Access Journals (Sweden)

Anjan Sarkar

2017-04-01

Full Text Available The paper describes a thermal analysis of a three-phase inverter operated under a Sinusoidal Pulse Width Modulation (SPWM technique which used three sine waves displaced in 120° phase difference as reference signals. The IGBT unit is assumed to be placed with a heat sink inside an evacuated chamber and the entire heat has to be transferred by conduction and radiation. The main heat sources present here are the set of IGBTs and diodes which generates heat on a pulse basing on their switching frequencies. Melcosim (a well-known tool developed by Mitsubishi Electric Corporation has been used to generate the power pulse from one set of IGBT and diode connected to a phase. A Scilab code is written to study the conduction and thermal radiation of heat sink and their combined effect on transient growth of the junction temperature of IGBT unit against complex switching pulses. The results mainly show that how thermal radiation from heat sink plays a crucial role in maintaining the junction temperature of IGBT within a threshold limit by adjusting various heat sink parameters. As the IGBT heat generation rate becomes higher, radiative heat transfer of the heat sink increases sharply which enhances overall cooling performance of the system.

Phase-transformation and subgrain-deformation characteristics in a cobalt-based superalloy

International Nuclear Information System (INIS)

Benson, M.L.; Reetz, B.; Liaw, P.K.; Reimers, W.; Choo, H.; Brown, D.W.; Saleh, T.A.; Klarstrom, D.L.

2011-01-01

Research highlights: → The mechanical behavior of a cobalt-based superalloy was investigated. → Two diffraction techniques were used to study deformation mechanisms of materials. → In-situ neutron diffraction provides the volume-averaged information. → The peak-profile analysis reveals the information on a subgrain level. → The material exhibited a transformation texture for the HCP phase under loading. - Abstract: A complimentary set of experiments, in situ neutron diffraction and ex situ synchrotron X-ray diffraction, were used to study the phase-transformation and subgrain-deformation characteristics of a cobalt-based superalloy. The neutron diffraction indicated a strain-induced phase transformation in the cobalt-based superalloy under uniaxial tension and compression. The synchrotron X-ray diffraction revealed stacking-fault accumulation and twinning under the same loading conditions. The extent of transformation was found to be greater under tension than under compression. Tensile plastic strains below 2% were accommodated by the stacking-fault creation, while those greater than 2% were accommodated by the phase transformation. Twinning was found to be more active under compressive loading than under tensile loading.

Radiation safety study for conventional facility and siting pre project phase of International Linear Collider

International Nuclear Information System (INIS)

Sanami, Toshiya; Ban, Syuichi; Sasaki, Shin-ichi

2015-01-01

The International Linear Collider (ILC) is a proposed high-energy collider consisting of two linear accelerators, two dumping rings, electron and positron sources, and a single colliding hall with two detectors. The total length and CMS energy of the ILC will be 31 km and 500 GeV, respectively (and 50 km and 1 TeV after future upgrade). The design of the ILC has entered the pre-project phase, which includes site-dependent design. Radiation safety design for the ILC is on-going as a part of conventional facility and siting activities of the pre-project phase. The thickness of a central wall of normal concrete is designed to be 3.5 m under a pessimistic assumption of beam loss. The beam loss scenario is under discussion. Experience and knowledge relating to shielding design and radiation control operational work at other laboratories are required. (authors)

Factors determining differences in biological effectiveness of ionizing radiations possessing different physical characteristics

International Nuclear Information System (INIS)

Korogodin, V.I.; Krasavin, E.A.

1982-01-01

Radiosensitivity of pro- and eukaryotes (D 0- 1 ) is considered with regard to the linear energy transfer (LET) of ionizing radiations. It was shown that radiosensitivity, as a function of LET, D 0- 1 (LET), is determined by not merely physical characteristics of radiations but also the ability of repair of DNA double strand breaks (DSB). The increase in the radiosensitivity of eukaryotes is connected with the decrease in the DSB repair when cells are exposed to densely ionizing particles. The decrease in DSB repair is apparently connected with the increment of straight DSB, comparing to enzymatic DSB, upon exposure to heavy ions. Potential mechanisms of D 0- 1 (LET) modifications for radiosensitive and superresistant mutants are discussed

Synthesis and reforming of high molecular-weigth compounds by the utilization of radiation

International Nuclear Information System (INIS)

Machi, Sueo

1976-01-01

Radiation effects on the synthesis are reforming of high molecular-weight compounds are reviewed. The report is divided into four main parts. The first part deals with the characteristics of the radiation processing. The reaction can be started in a wide range of temperature including very low temperature. Catalysts are unnecessary. The reaction velocity is fast, and the reaction in solid phase can be started uniformly. And the quality of products is well controllable. The second part deals with the synthesis of high molecular-weight compounds by radiation polymerization. Radical polymerization and ionizing polymerization, gas phase and liquid phase polymerization, the polymerization and copolymerization of fluorine-containing monomers, and solid phase polymerization and low temperature polymerization are included in this part. Attention is directed to the continuous production system for the radiation polymerization of ethylene developed by Japan Atomic Energy Research Institute. The third part deals with the reforming of high molecular-weight compounds by radiation graft polymerization. The combination of backbone polymers and monomers for reforming plastics and fibers, the membranes for reverse osmosis, porous membranes, and ion exchange membranes are included. The fourth part deals with the reforming of high molecular-weight compounds by the cross-linking. Polyethylene, PVC, ethyl acrylate copolymer and the like are included. (Iwakiri, K.)

Radiation resistant characteristics of optical fibers

International Nuclear Information System (INIS)

Nakasuji, Masaaki; Tanaka, Gotaro; Watanabe, Minoru; Kyodo, Tomohisa; Mukunashi, Hiroaki

1983-01-01

It is required to develop the optical fibers with good radiation resistivity because the fibers cause the increase of transmission loss due to glass colouring when they are used under the presence of radiation such as γ-ray. Generally, it is known that SI (step index) fibers are more resistive to radiation than GI (graded index) fibers. However, since a wide band can not be obtained with SI fibers, the development of radiation resistive GI optical fibers is desirable. In this report, the production for trial of the GI fibers of fluorine-doped silica core, the examination of radiation effect on their optical transmission loss by exposing them to γ-ray, thermal and fast neutron beams and also of mechanical strength are described. The GI fibers of fluorine-doped silica core show better radiation resistivity than Ge-doped ones. The B- and F-doped GI fibers show small increase of loss due to γ-ray, but large increase of loss due to thermal neutron beam. This is supposed to be caused by the far greater neutron absorption cross-section of boron than that of other elements. Significant increase of loss was not recognized when 14 MeV fast neutrons (8.6 x 10 4 n/cm 2 .s) were applied by 1.8 x 10 9 n/cm 2 . It was found that ETFE-covered fiber cores generated fluorine-containing gas due to γ irradiation, and the strength was remarkably lowered, but the lowering of strength can be prevented by adding titanium-white to the covering material. (Wakatsuki, Y.)

Characteristics of sound radiation from turbulent premixed flames

Science.gov (United States)

Rajaram, Rajesh

Turbulent combustion processes are inherently unsteady and, thus, a source of acoustic radiation, which occurs due to the unsteady expansion of reacting gases. While prior studies have extensively characterized the total sound power radiated by turbulent flames, their spectral characteristics are not well understood. The objective of this research work is to measure the flow and acoustic properties of an open turbulent premixed jet flame and explain the spectral trends of combustion noise. The flame dynamics were characterized using high speed chemiluminescence images of the flame. A model based on the solution of the wave equation with unsteady heat release as the source was developed and was used to relate the measured chemiluminescence fluctuations to its acoustic emission. Acoustic measurements were performed in an anechoic environment for several burner diameters, flow velocities, turbulence intensities, fuels, and equivalence ratios. The acoustic emissions are shown to be characterized by four parameters: peak frequency (Fpeak), low frequency slope (beta), high frequency slope (alpha) and Overall Sound Pressure Level (OASPL). The peak frequency (Fpeak) is characterized by a Strouhal number based on the mean velocity and a flame length. The transfer function between the acoustic spectrum and the spectrum of heat release fluctuations has an f2 dependence at low frequencies, while it converged to a constant value at high frequencies. Furthermore, the OASPL was found to be characterized by (Fpeak mfH)2, which resembles the source term in the wave equation.

Analyses of the radiation-caused characteristics change in SOI MOSFETs using field shield isolation

International Nuclear Information System (INIS)

Hirano, Yuuichi; Maeda, Shigeru; Fernandez, Warren; Iwamatsu, Toshiaki; Yamaguchi, Yasuo; Maegawa, Shigeto; Nishimura, Tadashi

1999-01-01

Reliability against radiation ia an important issue in silicon on insulator metal oxide semiconductor field effect transistors (SOI MOSFETs) used in satellites and nuclear power plants and so forth which are severely exposed to radiation. Radiation-caused characteristic change related to the isolation-edge in an irradiated environment was analyzed on SOI MOSFETs. Moreover short channel effects for an irradiated environment were investigated by simulations. It was revealed that the leakage current which was observed in local oxidation of silicon (LOCOS) isolated SOI MOSFETs was successfully suppressed by using field shield isolation. Simulated potential indicated that the potential rise at the LOCOS edge can not be seen in the case of field shield isolation edge which does not have physical isolation. Also it was found that the threshold voltage shift caused by radiation in short channel regime is severer than that in long regime channel. In transistors with a channel length of 0.18μm, a potential rise of the body region by radiation-induced trapped holes can be seen in comparison with that of 1.0μm. As a result, we must consider these effects for designing deep submicron devices used in an irradiated environment. (author)

Experimental research on the electromagnetic radiation (EMR) characteristics of cracked rock.

Science.gov (United States)

Song, Xiaoyan; Li, Xuelong; Li, Zhonghui; Cheng, Fuqi; Zhang, Zhibo; Niu, Yue

2018-03-01

Coal rock would emit the electromagnetic radiation (EMR) while deformation and fracture, and there exists structural body in the coal rock because of mining and geological structure. In this paper, we conducted an experimental test the EMR characteristics of cracked rock under loading. Results show that crack appears firstly in the prefabricated crack tip then grows stably parallel to the maximum principal stress, and the coal rock buckling failure is caused by the wing crack tension. Besides, the compressive strength significantly decreases because of the precrack, and the compressive strength increases with the crack angle. Intact rock EMR increases with the loading, and the cracked rock EMR shows stage and fluctuant characteristics. The bigger the angle, the more obvious the stage and fluctuant characteristics, that is EMR becomes richer. While the cracked angle is little, EMR is mainly caused by the electric charge rapid separates because of friction sliding. While the cracked angle is big, there is another significant contribution to EMR, which is caused by the electric dipole transient of crack expansion. Through this, we can know more clear about the crack extends route and the corresponding influence on the EMR characteristic and mechanism, which has important theoretical and practical significance to monitor the coal rock dynamical disasters.

Radiation Alert Immediate Disclosure, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Invocon's Radiation Alert Immediate Disclosure (RAID) system is a miniature, low-power, real-time, active radiation badge. It is designed for monitoring personnel,...

Three-phase Power Flow Calculation of Low Voltage Distribution Network Considering Characteristics of Residents Load

Science.gov (United States)

Wang, Yaping; Lin, Shunjiang; Yang, Zhibin

2017-05-01

In the traditional three-phase power flow calculation of the low voltage distribution network, the load model is described as constant power. Since this model cannot reflect the characteristics of actual loads, the result of the traditional calculation is always different from the actual situation. In this paper, the load model in which dynamic load represented by air conditioners parallel with static load represented by lighting loads is used to describe characteristics of residents load, and the three-phase power flow calculation model is proposed. The power flow calculation model includes the power balance equations of three-phase (A,B,C), the current balance equations of phase 0, and the torque balancing equations of induction motors in air conditioners. And then an alternating iterative algorithm of induction motor torque balance equations with each node balance equations is proposed to solve the three-phase power flow model. This method is applied to an actual low voltage distribution network of residents load, and by the calculation of three different operating states of air conditioners, the result demonstrates the effectiveness of the proposed model and the algorithm.

Change of nucleolus characteristic of fish embryo cells under the influence of low-level radiation

International Nuclear Information System (INIS)

Arkhipchuk, V.V.

1995-01-01

The nucleolus activity of fish embryo cells was stimulated by low-level radiation at a dose rate of 2-13 mGy/h. The size of nucleoli generally increased in embryos of Cyprinus carpio, whereas the number of nucleoli was greater in embryos of Carassius auratus gibelio. The higher the functional activity of nucleolus is, the more pronounced are changes in the characteristics. The size of single nucleolus at gastrulation is the most sensitive characteristic. 16 refs.; 1 tab

Thermoluminescent characteristics of diopside-teflon composites for radiation dosimetry

International Nuclear Information System (INIS)

Melo, A.P.; Caldas, L.V.E.

2006-01-01

Diopside - Teflon composites were been studied in relation to their dosimetric properties for high-dose dosimetry. Diopside from Minas Gerais, Brazil, CaMg(Si 2 O 6 ), was obtained in form of rude mineral with inclusions of quartz. The samples were prepared and only Diopside grains obtained. Pellets of Diopside-Teflon composites were prepared in the proportion of 2(Teflon): 1 (Diopside).The TL response repeatability presented a maximum coefficient of variation of 7.5%. The calibration curve is linear between 0.5 Gy and 1 kGy. TL emission spectra present three emissions of similar intensities at 570 nm, 590 nm and between 610-635 nm. The results suggest that the material presents good characteristics for use as high-dose radiation detectors. (Author)

Orbital radiation imaging with various physical principles

Energy Technology Data Exchange (ETDEWEB)

Takeda, Toru; Itai, Yuji [Tsukuba Univ., Ibaraki (Japan). Inst. of Clinical Medicine

2001-06-01

This paper describes the characteristics of orbital radiation and authors' investigations on the high spatial resolution X ray-CT, fluorescence X ray-CT and phase-type X ray imaging. Orbital radiation is an X ray generated by relativistic electron bended by magnet in the synchrotron and possesses the high photon density/unit area (>100,000 times higher than that of the ordinary X ray generated by the tube) and broad energy spectrum, which make it possible to select the X ray with appropriate energy for the target. The high spatial resolution X-CT has the resolution of 0.05 mm in contrast to 0.5 mm of the ordinary X-CT and is used for the hard structure like tooth and bone. The CT images of rat lumbar vertebrae and artificial bone are presented. Fluorescence X-CT is utilized for detection of trace elements. Images of the thyroid are presented on iodine detection. Concerning the phase-type X-imaging, the principle using the X ray interferometer is described and actual phase-images of blood vessels and 3-demensional ones of metastatic colon cancer in the liver are given. Imaging with the orbital radiation can be a useful technique in the near future. (K.H.)

Orbital radiation imaging with various physical principles

International Nuclear Information System (INIS)

Takeda, Toru; Itai, Yuji

2001-01-01

This paper describes the characteristics of orbital radiation and authors' investigations on the high spatial resolution X ray-CT, fluorescence X ray-CT and phase-type X ray imaging. Orbital radiation is an X ray generated by relativistic electron bended by magnet in the synchrotron and possesses the high photon density/unit area (>100,000 times higher than that of the ordinary X ray generated by the tube) and broad energy spectrum, which make it possible to select the X ray with appropriate energy for the target. The high spatial resolution X-CT has the resolution of 0.05 mm in contrast to 0.5 mm of the ordinary X-CT and is used for the hard structure like tooth and bone. The CT images of rat lumbar vertebrae and artificial bone are presented. Fluorescence X-CT is utilized for detection of trace elements. Images of the thyroid are presented on iodine detection. Concerning the phase-type X-imaging, the principle using the X ray interferometer is described and actual phase-images of blood vessels and 3-demensional ones of metastatic colon cancer in the liver are given. Imaging with the orbital radiation can be a useful technique in the near future. (K.H.)

Application of ionizing radiation processing in biomedical engineering and microelectronics

International Nuclear Information System (INIS)

Hongfej, H.; Jilan, W.

1988-01-01

The applied radiation chemistry has made great contributions to the development of polymeric industrial materials by the characteristics reaction means such as crosslinking, graft copolymerization and low-temperature or solid-phase polymerization, and become a important field on peaceful use of atomic energy. A brief review on the applications of ionizing radiation processing in biomedical engineering and microelectronics is presented. The examples of this technique were the studies on biocompatible and biofunctional polymers for medical use and on resists of lithography in microelectronics

Fluctuation characteristics of solar radiation in crop cultivation

International Nuclear Information System (INIS)

Hayashi, S.; Suzuki, H.

1996-01-01

The objective of this study was to clarify the fluctuation of solar radiation for long and short periods, which is very crucial for plant growth. Data obtained from a meteorological observatory were used to investigate solar radiation and sunshine duration for a long period. For a short period, observation of global solar radiation and sky solar radiation were conducted in a glass house and at an open field. (1) Yearly average percentage of solar radiation at Kagawa from 1973 to 1994 was 44.3%, and its coefficient of variation was 3.9%. The percentage of possible sunshine and the coefficient were larger than those of solar radiation, 47.3% and 56% respectively. (2) Percentage of possible solar radiation and percentage of possible sunshine showed seasonal variation. Those coefficients of variation both increased exponentially with cloud amount. (3) Variations of global solar radiation and direct solar radiation were more remarkable in the glass house than those in the open field, while variations of sky solar radiation were small in the house and at the open field. (4) The fluctuation of solar radiation observed every 5 minutes was presented as the difference of radiation, present value minus the preceding value. The difference was positive in the morning, negative in the afternoon at the open field. In the house both positive and negative values were obtained the whole day. (5) Diurnal variation of ratio of direct solar radiation to sky solar radiation showed a parabolic effect, whereas it had irregular and large fluctuations at the open field

AOI 1— COMPUTATIONAL ENERGY SCIENCES:MULTIPHASE FLOW RESEARCH High-fidelity multi-phase radiation module for modern coal combustion systems

Energy Technology Data Exchange (ETDEWEB)

Modest, Michael

2013-11-15

The effects of radiation in particle-laden flows were the object of the present research. The presence of particles increases optical thickness substantially, making the use of the “optically thin” approximation in most cases a very poor assumption. However, since radiation fluxes peak at intermediate optical thicknesses, overall radiative effects may not necessarily be stronger than in gas combustion. Also, the spectral behavior of particle radiation properties is much more benign, making spectral models simpler (and making the assumption of a gray radiator halfway acceptable, at least for fluidized beds when gas radiation is not large). On the other hand, particles scatter radiation, making the radiative transfer equation (RTE) much more di fficult to solve. The research carried out in this project encompassed three general areas: (i) assessment of relevant radiation properties of particle clouds encountered in fluidized bed and pulverized coal combustors, (ii) development of proper spectral models for gas–particulate mixtures for various types of two-phase combustion flows, and (iii) development of a Radiative Transfer Equation (RTE) solution module for such applications. The resulting models were validated against artificial cases since open literature experimental data were not available. The final models are in modular form tailored toward maximum portability, and were incorporated into two research codes: (i) the open-source CFD code OpenFOAM, which we have extensively used in our previous work, and (ii) the open-source multi-phase flow code MFIX, which is maintained by NETL.

Social, economic and political aspects of Chernobyl in Bulgaria - One characteristic feature of the development of the radiation situation

International Nuclear Information System (INIS)

Belokonski, I.I.; Bosevski, V.; Bontchev, Tz.; Marinov, V.

1997-01-01

It is shown a characteristic feature of the progress of radiation situation in Bulgaria after the failure in Chernobyl, as this was discussed untraditionally. The raised radiation risk for population during one year after the incident is interpreted as function from the inadequate radiation protection policy of the Government at that time. Preconditions for some social, economical and political results after the accident for Bulgarian country are described

Characteristics Of Dosimeter TL CaSO4:Dy Glass Capillaries For Environmental Radiation Dose Monitoring

International Nuclear Information System (INIS)

Sofyan Hasnel; Yulianti, Helfi; Ramain, Abubakar; Kusumawati, Dyah D.; Suyati

2000-01-01

research on the characteristic of dosimeter TL CaSO 4 : Dy glass capillaries for environmental dose radiation have been carried out. The results obtained are uniform response and reproducibility during three cycles consumption with average percentage standard deviation of 7.31 % and 5.45%. The response dose is linear and has a minimum detectable dose of 0.01 mGy, sunshine effect with non-penetrating light capsule of 4.65%, humidity effects is not significant by using non-penetrating light capsule. Radiation dose information during 30 days are fading 25%

Amplitude and Phase Characteristics of Signals at the Output of Spatially Separated Antennas for Paths with Scattering

Science.gov (United States)

Anikin, A. S.

2018-06-01

Conditional statistical characteristics of the phase difference are considered depending on the ratio of instantaneous output signal amplitudes of spatially separated weakly directional antennas for the normal field model for paths with radio-wave scattering. The dependences obtained are related to the physical processes on the radio-wave propagation path. The normal model parameters are established at which the statistical characteristics of the phase difference depend on the ratio of the instantaneous amplitudes and hence can be used to measure the phase difference. Using Shannon's formula, the amount of information on the phase difference of signals contained in the ratio of their amplitudes is calculated depending on the parameters of the normal field model. Approaches are suggested to reduce the shift of phase difference measured for paths with radio-wave scattering. A comparison with results of computer simulation by the Monte Carlo method is performed.

The far infrared radiation characteristics for Li2O.Al2O3.4SiO2(LAS) glass-ceramics and transition-metal oxide

International Nuclear Information System (INIS)

Huh, Nam Jung; Yang, Joong Sik

1991-01-01

The far infrared radiation characteristic for Li 2 O.Al 2 O 3 .4SiO 2 (LAS) glass, the LAS glass-ceramic and sintered transition metal oxides such as CuO, Fe 2 O 3 and Co 3 O 4 , were investigated. LAS glass and LAS glass-ceramic was higher than that of the LAS glass. Heat-treated CuO and Co 3 o 4 had radiation characteristic of high efficiency infrared radiant, and heat-treated Fe 2 O 3 had radiation characteristic that infrared emissivity decreased in higher was length above 15μm. (Author)

Phase locked multiple rings in the radiation pressure ion acceleration process

Science.gov (United States)

Wan, Y.; Hua, J. F.; Pai, C.-H.; Li, F.; Wu, Y. P.; Lu, W.; Zhang, C. J.; Xu, X. L.; Joshi, C.; Mori, W. B.

2018-04-01

Laser contrast plays a crucial role for obtaining high quality ion beams in the radiation pressure ion acceleration (RPA) process. Through one- and two-dimensional particle-in-cell (PIC) simulations, we show that a plasma with a bi-peak density profile can be produced from a thin foil on the effects of a picosecond prepulse, and it can then lead to distinctive modulations in the ion phase space (phase locked double rings) when the main pulse interacts with the target. These fascinating ion dynamics are mainly due to the trapping effect from the ponderomotive potential well of a formed moving standing wave (i.e. the interference between the incoming pulse and the pulse reflected by a slowly moving surface) at nodes, quite different from the standard RPA process. A theoretical model is derived to explain the underlying mechanism, and good agreements have been achieved with PIC simulations.

Multi-scale full-orbit analysis on phase-space behavior of runaway electrons in tokamak fields with synchrotron radiation

Energy Technology Data Exchange (ETDEWEB)

Wang, Yulei; Liu, Jian, E-mail: jliuphy@ustc.edu.cn [School of Nuclear Science and Technology and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Key Laboratory of Geospace Environment, CAS, Hefei, Anhui 230026 (China); Qin, Hong [School of Nuclear Science and Technology and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)

2016-06-15

In this paper, the secular full-orbit simulations of runaway electrons with synchrotron radiation in tokamak fields are carried out using a relativistic volume-preserving algorithm. Detailed phase-space behaviors of runaway electrons are investigated in different dynamical timescales spanning 11 orders. In the small timescale, i.e., the characteristic timescale imposed by Lorentz force, the severely deformed helical trajectory of energetic runaway electron is witnessed. A qualitative analysis of the neoclassical scattering, a kind of collisionless pitch-angle scattering phenomena, is provided when considering the coupling between the rotation of momentum vector and the background magnetic field. In large timescale up to 1 s, it is found that the initial condition of runaway electrons in phase space globally influences the pitch-angle scattering, the momentum evolution, and the loss-gain ratio of runaway energy evidently. However, the initial value has little impact on the synchrotron energy limit. It is also discovered that the parameters of tokamak device, such as the toroidal magnetic field, the loop voltage, the safety factor profile, and the major radius, can modify the synchrotron energy limit and the strength of neoclassical scattering. The maximum runaway energy is also proved to be lower than the synchrotron limit when the magnetic field ripple is considered.

Phase 2 Randomized Controlled Trial of Radiation Therapy Plus Concurrent Interferon-Alpha and Retinoic Acid Versus Cisplatin for Stage III Cervical Carcinoma

Energy Technology Data Exchange (ETDEWEB)

Basu, Partha, E-mail: BasuP@iarc.fr [Screening Group, Early Detection and Prevention Section, International Agency for Research on Cancer, Lyon (France); Jenson, Alfred Bennett [James Graham Brown Cancer Center, University of Louisville, Louisville, Kentucky (United States); Majhi, Tapas; Choudhury, Prabir [Department of Radiation Oncology, Chittaranjan National Cancer Institute, Kolkata (India); Mandal, Ranajit; Banerjee, Dipanwita [Department of Gynecological Oncology, Chittaranjan National Cancer Institute, Kolkata (India); Biswas, Jaydip [Department of Surgical Oncology, Chittaranjan National Cancer Institute, Kolkata (India); Pan, Jianmin; Rai, Shesh Nath; Ghim, Shin je; Miller, Donald [James Graham Brown Cancer Center, University of Louisville, Louisville, Kentucky (United States)

2016-01-01

Purpose: Because a combination of retinoic acid, interferon-alpha, and radiation therapy demonstrated synergistic action and effectiveness to treat advanced cervical cancers in earlier studies, we designed this randomized phase 2 open-label trial to assess efficacy and safety of interferon alpha-2b (IFN) and 13-cis-retinoic acid (RA) administered concomitantly with radiation therapy (IFN-RA-radiation) to treat stage III cervical cancer. Methods and Materials: Stage III cervical cancer patients were randomized to study and control groups in a 1:1 ratio. All patients were treated with radiation therapy; study arm patients received IFN (3 × 10{sup 6} IU subcutaneously) 3 times a week for 4 weeks and daily RA (40 mg orally) for 30 days starting on day 1 of radiation, whereas control arm patients received weekly cisplatinum (40 mg/m{sup 2}) for 5 weeks during radiation. Patients were followed for 3 years. The primary endpoint was overall survival at 3 years. Results: Patients in the study (n=104) and control (n=105) groups were comparable for clinicopathological characteristics, radiation therapy–related variables and treatment response. Proportions of disease-free patients in the study and control groups were 38.5% and 44.8%, respectively, after median follow-up of 29.2 months. Hazard ratios were 0.67 (95% confidence interval [CI]: 0.44-1.01) and 0.69 (95% CI: 0.44-1.06) for overall and disease-fee survival, respectively, comparing the study group to control, and demonstrated an inferior outcome with RA-IFN-radiation, although differences were statistically nonsignificant. Kaplan-Meier curves of disease-free and overall survival probabilities also showed inferior survival in the study group compared to those in the control. Acute toxicities of chemoradiation were significantly higher with 2 acute toxicity-related deaths. Conclusions: Treatment with RA-IFN-radiation did not demonstrate survival advantage over chemoradiation despite being less toxic. The

Characteristics of phase-change materials containing oxide nano-additives for thermal storage.

Science.gov (United States)

Teng, Tun-Ping; Yu, Chao-Chieh

2012-11-06

In this study, the authors report the production of nanocomposite-enhanced phase-change materials (NEPCMs) using the direct-synthesis method by mixing paraffin with alumina (Al2O3), titania (TiO2), silica (SiO2), and zinc oxide (ZnO) as the experimental samples. Al2O3, TiO2, SiO2, and ZnO were dispersed into three concentrations of 1.0, 2.0, and 3.0 wt.%. Through heat conduction and differential scanning calorimeter experiments to evaluate the effects of varying concentrations of the nano-additives on the heat conduction performance and thermal storage characteristics of NEPCMs, their feasibility for use in thermal storage was determined. The experimental results demonstrate that TiO2 is more effective than the other additives in enhancing both the heat conduction and thermal storage performance of paraffin for most of the experimental parameters. Furthermore, TiO2 reduces the melting onset temperature and increases the solidification onset temperature of paraffin. This allows the phase-change heat to be applicable to a wider temperature range, and the highest decreased ratio of phase-change heat is only 0.46%, compared to that of paraffin. Therefore, this study demonstrates that TiO2, added to paraffin to form NEPCMs, has significant potential for enhancing the thermal storage characteristics of paraffin.

Damping characteristic identification of non-linear soil-structural system interaction by phase resonance

International Nuclear Information System (INIS)

Poterasu, V.F.

1984-01-01

It is presented a method and the phase resonance for damping characteristic identification of non-linear soil-structural interaction. The algorithm can be applied in case of any, not necessarily, damping characteristic of the system examined. For the identification, the system is harmonically excited and are considered the super-harmonic amplitudes for odd and even powers of the x. The response of shear beam system for different levels of base excitation and for different locations of the load is considered. (Author) [pt

Experimental investigation of the ECRH stray radiation during the start-up phase in Wendelstein 7-X

Science.gov (United States)

Moseev, Dmitry; Laqua, Heinrich; Marsen, Stefan; Stange, Torsten; Braune, Harald; Erckmann, Volker; Gellert, Florian; Oosterbeek, Johann Wilhelm; Wenzel, Uwe

2017-07-01

Electron cyclotron resonance heating (ECRH) is the main heating mechanism in the Wendelstein 7-X stellarator (W7-X). W7-X is equipped with five absolutely calibrated sniffer probes that are installed in each of the five modules of the device. The sniffer probes monitor energy flux of unabsorbed ECRH radiation in the device and interlocks are fed with the sniffer probe signals. The stray radiation level in the device changes significantly during the start-up phase: plasma is a strong microwave absorber and during its formation the stray radiation level in sniffer probes reduces by more than 95%. In this paper, we discuss the influence of neutral gas pressure and gyrotron power on plasma breakdown processes.

Two-Phase Instability Characteristics of Printed Circuit Steam Generator for the Low Pressure Condition

International Nuclear Information System (INIS)

Kang, Han-Ok; Han, Hun Sik; Kim, Young-In; Kim, Keung Koo

2015-01-01

Reduction of installation space for steam generators can lead to much smaller reactor vessel with resultant decrease of overall manufacturing cost for the components. A PCHE(Printed Circuit Heat Exchanger) is one of the compact types of heat exchangers available as an alternative to conventional shell and tube heat exchangers. Its name is derived from the procedure used to manufacture the flat metal plates that form the core of the heat exchanger, which is done by chemical milling. These plates are then stacked and diffusion bonded, converting the plates into a solid metal block containing precisely engineered fluid flow passages. PCSG(Printed Circuit Steam Generator) is a potential candidate to be applied to the integral reactor with its compactness and mechanical robustness. For the introduction of new steam generator, design requirement for the two-phase flow instability should be considered. This paper describes two-phase flow instability characteristics of PCSG for the low pressure condition. PCSG is a potential candidate to be applied to the integral reactor with its compactness and mechanical robustness. Interconnecting flow path was developed to mitigate the two-phase flow instability in the cold side. The flow characteristics of two-phase flow instability at the PCSG is examined experimentally in this study

Applications of ionizing radiation processing in biomedical engineering and microelectronics

International Nuclear Information System (INIS)

Ha Hongfei; Wu Jilan

1987-01-01

The applied radiation chemistry has made great contributions to the development of polymeric industrial materials by the characteristic reaction means such as corsslinking, graft copolymerization and low-temperature or solid-phase polymerization, and become an important field on peaceful use of atomic energy. A brief review on the applications of ionizing radiation processing in biomedical engineering and microelectronics is presented. The examples of this techique were the studies on biocompatible and biofunctional polymers for medical use and on resists of lithography in microelectronics. (author)

Numerical investigation of refrigeration machine compressor operation considering single-phase electric motor dynamic characteristics

Science.gov (United States)

Baidak, Y.; Smyk, V.

2017-08-01

Using as the base the differential equations system which was presented in relative units for generalized electric motor of hermetic refrigeration compressor, mathematical model of the software for dynamic performance calculation of refrigeration machine compressors drive low-power asynchronous motors was developed. Performed on its ground calculations of the basic model of two-phase electric motor drive of hermetic compressor and the proposed newly developed model of the motor with single-phase stator winding, which is an alternative to the industrial motor winding, have confirmed the benefits of the motor with innovative stator winding over the base engine. Given calculations of the dynamic characteristics of compressor drive motor have permitted to determine the value of electromagnetic torque swinging for coordinating compressor and motor mechanical characteristics, and for taking them into consideration in choosing compressor elements construction materials. Developed and used in the process of investigation of refrigeration compressor drive asynchronous single-phase motor mathematical and software can be considered as an element of computer-aided design system for design of the aggregate of refrigeration compression unit refrigerating machine.

Ultra-Wideband Printed Slot Radiators with Controllable Frequency Characteristics

Directory of Open Access Journals (Sweden)

S. L. Chernyshev

2015-01-01

Full Text Available We have studied the possibility of creating ultra-wideband (UWB antennas with controlled frequency response of matching based on the printed slot antenna Vivaldi by introducing controlled resonators directly into the structure of the radiator. In the area of irregular slotline there are printed switched resonators with variable capacitance (varactor model, which allow tuning the frequency characteristics for each state of switching cavities, providing bandpass and band-barrage properties of the antenna. The investigation of reconfigurable printed resonators in the system of reconfigurable resonators of a bandpass filter is conducted. The paper considers filter to provide restructuring in the band (3-9 GHz. Electrodynamic simulation of the device was carried out in the time domain using a finite integration method. A bandstop reconfigurable filter is also investigated. The filter located on the substrate opposite the slit is based on tunable L-shaped resonator that has one end connected to the short-circuitor through the board metallization; the other end remains open and is brought into the region of interaction with the slotline. Such filter provides an effective narrow-band suppression and can be easily tuned to the desired frequency channel. The combination of these two types of filters allows you to create a controlled print Vivaldi slot antenna with combined properties. The paper investigates parameters of the scattering and radiation pattern of the antenna in different modes.

Unique proteomic signature for radiation sensitive patients; a comparative study between normo-sensitive and radiation sensitive breast cancer patients

Energy Technology Data Exchange (ETDEWEB)

Skiöld, Sara [Center for Radiation Protection Research, Department of Molecular Biosciences, The Wernner-Gren Institute, Stockholm University, Stockholm (Sweden); Azimzadeh, Omid [Institute of Radiation Biology, German Research Center for Environmental Health, Helmholtz Zentrum München (Germany); Merl-Pham, Juliane [Research Unit Protein Science, German Research Center for Environmental Health, Helmholtz Zentrum München, Neuherberg (Germany); Naslund, Ingemar; Wersall, Peter; Lidbrink, Elisabet [Division of Radiotherapy, Radiumhemmet, Karolinska University Hospital, Stockholm (Sweden); Tapio, Soile [Institute of Radiation Biology, German Research Center for Environmental Health, Helmholtz Zentrum München (Germany); Harms-Ringdahl, Mats [Center for Radiation Protection Research, Department of Molecular Biosciences, The Wernner-Gren Institute, Stockholm University, Stockholm (Sweden); Haghdoost, Siamak, E-mail: Siamak.Haghdoost@su.se [Center for Radiation Protection Research, Department of Molecular Biosciences, The Wernner-Gren Institute, Stockholm University, Stockholm (Sweden)

2015-06-15

Highlights: • The unique protein expression profiles were found that separate radiosensitive from normal sensitive breast cancer patients. • The oxidative stress response, coagulation properties and acute phase response suggested to be the hallmarks of radiation sensitivity. - Abstract: Radiation therapy is a cornerstone of modern cancer treatment. Understanding the mechanisms behind normal tissue sensitivity is essential in order to minimize adverse side effects and yet to prevent local cancer reoccurrence. The aim of this study was to identify biomarkers of radiation sensitivity to enable personalized cancer treatment. To investigate the mechanisms behind radiation sensitivity a pilot study was made where eight radiation-sensitive and nine normo-sensitive patients were selected from a cohort of 2914 breast cancer patients, based on acute tissue reactions after radiation therapy. Whole blood was sampled and irradiated in vitro with 0, 1, or 150 mGy followed by 3 h incubation at 37 °C. The leukocytes of the two groups were isolated, pooled and protein expression profiles were investigated using isotope-coded protein labeling method (ICPL). First, leukocytes from the in vitro irradiated whole blood from normo-sensitive and extremely sensitive patients were compared to the non-irradiated controls. To validate this first study a second ICPL analysis comparing only the non-irradiated samples was conducted. Both approaches showed unique proteomic signatures separating the two groups at the basal level and after doses of 1 and 150 mGy. Pathway analyses of both proteomic approaches suggest that oxidative stress response, coagulation properties and acute phase response are hallmarks of radiation sensitivity supporting our previous study on oxidative stress response. This investigation provides unique characteristics of radiation sensitivity essential for individualized radiation therapy.

Unique proteomic signature for radiation sensitive patients; a comparative study between normo-sensitive and radiation sensitive breast cancer patients

International Nuclear Information System (INIS)

Skiöld, Sara; Azimzadeh, Omid; Merl-Pham, Juliane; Naslund, Ingemar; Wersall, Peter; Lidbrink, Elisabet; Tapio, Soile; Harms-Ringdahl, Mats; Haghdoost, Siamak

2015-01-01

Highlights: • The unique protein expression profiles were found that separate radiosensitive from normal sensitive breast cancer patients. • The oxidative stress response, coagulation properties and acute phase response suggested to be the hallmarks of radiation sensitivity. - Abstract: Radiation therapy is a cornerstone of modern cancer treatment. Understanding the mechanisms behind normal tissue sensitivity is essential in order to minimize adverse side effects and yet to prevent local cancer reoccurrence. The aim of this study was to identify biomarkers of radiation sensitivity to enable personalized cancer treatment. To investigate the mechanisms behind radiation sensitivity a pilot study was made where eight radiation-sensitive and nine normo-sensitive patients were selected from a cohort of 2914 breast cancer patients, based on acute tissue reactions after radiation therapy. Whole blood was sampled and irradiated in vitro with 0, 1, or 150 mGy followed by 3 h incubation at 37 °C. The leukocytes of the two groups were isolated, pooled and protein expression profiles were investigated using isotope-coded protein labeling method (ICPL). First, leukocytes from the in vitro irradiated whole blood from normo-sensitive and extremely sensitive patients were compared to the non-irradiated controls. To validate this first study a second ICPL analysis comparing only the non-irradiated samples was conducted. Both approaches showed unique proteomic signatures separating the two groups at the basal level and after doses of 1 and 150 mGy. Pathway analyses of both proteomic approaches suggest that oxidative stress response, coagulation properties and acute phase response are hallmarks of radiation sensitivity supporting our previous study on oxidative stress response. This investigation provides unique characteristics of radiation sensitivity essential for individualized radiation therapy

Determining the magnetically nonlinear characteristics of a three phase core-type power transformer

International Nuclear Information System (INIS)

Dolinar, Matjaz; Stumberger, Gorazd; Polajzer, Bostjan; Dolinar, Drago

2006-01-01

This paper presents nonlinear iron core model of a three-phase, three-limb power transformer which is given by the current-dependant characteristics of flux linkages. The magnetically nonlinear characteristics are determined by controlled magnetic excitation of all three limbs which allows to take into account the variable magnetic-cross couplings between different coils placed on limbs, caused by saturation. The corresponding partial derivatives of measured flux linkage characteristics are used in the transformer circuit model as a magnetically nonlinear iron core model in order to analyze the behaviour of a nonsymmetrically excited transformer. Numerical results using transformer model with the determined iron core model agree very well with the measured results

Characteristics of porous polymer composite columns prepared by radiation cast-polymerization

International Nuclear Information System (INIS)

Kumakura, Minoru; Kaetsu, Isao; Asami, Kazuhiro; Suzuki, Shuichi

1989-01-01

Porous polymer composite columns having porous structure were prepared by radiation cast-polymerization of hydrophilic monomers at low temperature and their characteristics were studied. The porosity of the polymer increased with decreasing monomer concentration. The elution time of water in the polymer column increased with increasing monomer concentration and with decreasing irradiation temperature. The elution time was dependent on the degree of hydration of the polymer. The polymer with a degree of hydration of 0.2 to 0.4 gave the minimum elution time. The elution time decreased with the addition of porous inorganic substances. (author)

FEL gain optimisation and spontaneous radiation

Energy Technology Data Exchange (ETDEWEB)

Bali, L.M.; Srivastava, A.; Pandya, T.P. [Lucknow Univ. (India)] [and others

1995-12-31

Colson have evaluated FEL gains for small deviations from perfect electron beam injection, with radiation of the same polarisation as that of the wiggler fields. We find that for optimum gain the polarisation of the optical field should be the same as that of the spontaneous emission under these conditions. With a helical wiggler the axial oscillations resulting from small departures from perfect electron beam injection lead to injection dependent unequal amplitudes and phases of the spontaneous radiation in the two transverse directions. Viewed along the axis therefore the spontaneous emission is elliptically polarised. The azimuth of the ellipse varies with the difference of phase of the two transverse components of spontaneous emission but the eccentricity remains the same. With planar wigglers the spontaneous emission viewed in the axial direction is linearly polarised, again with an injection dependent azimuth. For optimum coherent gain of a radiation field its polarisation characteristics must be the same as those of the spontaneous radiation with both types of wiggler. Thus, with a helical wiggler and the data reported earlier, an increase of 10% in the FEL gain at the fundamental frequency and of 11% at the fifth harmonic has been calculated in the small gain per pass limit. Larger enhancements in gain may result from more favourable values of input parameters.

Dispersion characteristics of planar grating with arbitrary grooves for terahertz Smith-Purcell radiation

International Nuclear Information System (INIS)

Cao, Miaomiao; Li, Ke; Liu, Wenxin; Wang, Yong

2015-01-01

In this paper, a novel method of getting the dispersion relations in planar grating with arbitrary grooves for terahertz Smith-Purcell radiation is investigated analytically. The continuous profile of the groove is approximately replaced by a series of rectangular steps. By making use of field matches method and the continuity of transverse admittance, the universal dispersion equation for grating with arbitrarily shaped grooves is derived. By solving the dispersion equation in presence of electron beam, the growth rate is obtained directly and the dependence on beam parameters is analyzed. Comparisons of the dispersion characteristics among some special groove shapes have been made by numerical calculation. The results show that the rectangular-step approximation method provides a novel approach to obtain the universal dispersion relation for grating with arbitrary grooves for Smith-Purcell radiation

Shielding behavior of multi-transformation phase change materials (MTPCM) against nuclear radiations

International Nuclear Information System (INIS)

Kumar, Ravindra; Goplani, Deepak; Kumar, Rohitash; Das, Mrinal Kumar; Kumar, Pramod; Jodha, Ajay Singh; Misra, Manoj; Khatri, P.K.

2008-01-01

In nuclear hardened structures and AFV's, special shielding materials are being used to provide protection from radiations generated in nuclear blast. However, in blast an intense heat pulse is also generated along with radiation. Currently used shield does not take care of this heat pulse. Defence Laboratory, Jodhpur has developed multi transformation phase change materials (MTPCM) based cool panels for passive moderation of temperature in severe desert heat. The MTPCM contains light nuclei of hydrogen, carbon and oxygen, and thus can absorb good amount of neutrons. MTPCM can also absorb intense heat pulse along with heat generated by secondary fires during blast as its latent heat (160-170 J/g) without significant rise in temperature (melting point 36-38 deg. C). Thus MTPCM can provide protection against both radiation as well as heat pulse generated in a nuclear blast along with its designed regular function of passively moderating temperature below 40 deg C during severe desert summer. A study has been undertaken to explore multiple applications of MTPCM panel. Protection factor provided by standard MTPCM panels against neutron and gamma radiations (both initial and fall out) were measured and results compared with PF provided by special lining pad currently being used in AFV's and field structures for nuclear protection. It is observed that MTPCM provides good PF (2.17) against neutron which is better than currently used shield pads (PFP%1.8). Present paper discusses results of this study. (author)

Characteristics of x-ray radiation from a gas-puff z-pinch plasma

International Nuclear Information System (INIS)

Akiyama, N.; Takasugi, K.

2002-01-01

Characteristics of x-ray radiation from Ar gas-puff z-pinch plasma have been investigated by changing delay time of discharge from gas puffing. Intense cloud structure of x-ray image was observed at small delay time region, but the total x-ray signal was not so intense. The x-ray signal increased with increasing the delay time, and hot spots of x-ray image also became intense. Electron temperature was evaluated from x-ray spectroscopic data, and no significant difference in temperature was observed. (author)

Moon manned missions radiation safety analysis

Science.gov (United States)

Tripathi, R. K.; Wilson, J. W.; de Anlelis, G.; Badavi, F. F.

An analysis is performed on the radiation environment found on the surface of the Moon, and applied to different possible lunar base mission scenarios. An optimization technique has been used to obtain mission scenarios minimizing the astronaut radiation exposure and at the same time controlling the effect of shielding, in terms of mass addition and material choice, as a mission cost driver. The optimization process has been realized through minimization of mass along all phases of a mission scenario, in terms of time frame (dates, transfer time length and trajectory, radiation environment), equipment (vehicles, in terms of shape, volume, onboard material choice, size and structure), location (if in space, on the surface, inside or outside a certain habitats), crew characteristics (number, gender, age, tasks) and performance required (spacecraft and habitat volumes), radiation exposure annual and career limit constraint (from NCRP 132), and implementation of the ALARA principle (shelter from the occurrence of Solar Particle Events). On the lunar surface the most important contribution to radiation exposure is given by background Galactic Cosmic Rays (GCR) particles, mostly protons, alpha particles, and some heavy ions, and by locally induced particles, mostly neutrons, created by the interaction between GCR and surface material and emerging from below the surface due to backscattering processes. In this environment manned habitats are to host future crews involved in the construction and/or in the utilization of moon based infrastructure. Three different kinds of lunar missions are considered in the analysis, Moon Base Construction Phase, during which astronauts are on the surface just to build an outpost for future resident crews, Moon Base Outpost Phase, during which astronaut crews are resident but continuing exploration and installation activities, and Moon Base Routine Phase, with long-term shifting resident crews. In each scenario various kinds of habitats

Patterning characteristics of a chemically-amplified negative resist in synchrotron radiation lithography

International Nuclear Information System (INIS)

Deguchi, Kimiyoshi; Miyoshi, Kazunori; Ishii, Tetsuyoshi; Matsuda, Tadahito

1992-01-01

To explore the applicability of synchrotron radiation X-ray lithography for fabricating sub-quartermicron devices, we investigate the patterning characteristics of the chemically-amplified negative resist SAL601-ER7. Since these characteristics depend strongly on the conditions of the chemical amplification process, the effects of post-exposure baking and developing conditions on sensitivity and resolution are examined. The resolution-limiting factors are investigated, revealing that pattern collapse during the development process and fog caused by Fresnel diffraction, photo-electron scattering, and acid diffusion in the resist determine the resolution and the maximum aspect ratio of the lines and spaces pattern. Using the model of a swaying beam supported at one end, it is shown that pattern collapse depends on the resist pattern's flexural stiffness. Patterning stability, which depends on the delay time between exposure and baking, is also discussed. (author)

Transition radiation and diffraction radiation. Similarities and differences

International Nuclear Information System (INIS)

Potylitsyn, A.P.

1998-01-01

The characteristics of diffraction radiation (DR), i.e. radiation of the charged particle moving near conducting target have been considered for an ultrarelativistic case. The simple expressions for DR fields for the semi-infinite ideal conducting target have been derived. The close connection between transition radiation (TR) and DR has been shown. The effect of finite transversal sizes of target on TR characteristics has been evaluated. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

Heat transfer characteristics of liquid-gas Taylor flows incorporating microencapsulated phase change materials

International Nuclear Information System (INIS)

Howard, J A; Walsh, P A

2014-01-01

This paper presents an investigation on the heat transfer characteristics associated with liquid-gas Taylor flows in mini channels incorporating microencapsulated phase change materials (MPCM). Taylor flows have been shown to result in heat transfer enhancements due to the fluid recirculation experienced within liquid slugs which is attributable to the alternating liquid slug and gas bubble flow structure. Microencapsulated phase change materials (MPCM) also offer significant potential with increased thermal capacity due to the latent heat required to cause phase change. The primary aim of this work was to examine the overall heat transfer potential associated with combining these two novel liquid cooling technologies. By investigating the local heat transfer characteristics, the augmentation/degradation over single phase liquid cooling was quantified while examining the effects of dimensionless variables, including Reynolds number, liquid slug length and gas void fraction. An experimental test facility was developed which had a heated test section and allowed MPCM-air Taylor flows to be subjected to a constant heat flux boundary condition. Infrared thermography was used to record high resolution experimental wall temperature measurements and determine local heat transfer coefficients from the thermal entrance point. 30.2% mass particle concentration of the MPCM suspension fluid was examined as it provided the maximum latent heat for absorption. Results demonstrate a significant reduction in experimental wall temperatures associated with MPCM-air Taylor flows when compared with the Graetz solution for conventional single phase coolants. Total enhancement in the thermally developed region is observed to be a combination of the individual contributions due to recirculation within the liquid slugs and also absorption of latent heat. Overall, the study highlights the potential heat transfer enhancements that are attainable within heat exchange devices employing MPCM

Development of high voltage PEEK wire with radiation-resistance and cryogenic characteristics

International Nuclear Information System (INIS)

Fujita, T.; Hirata, T.; Araki, S.; Ohara, H.; Nishimura, H.

1989-01-01

High voltage electric wires insulated with highly-refined polyetheretherketone (PEEK) have been developed for the wiring in fusion reactors, where the wire is required to withstand high voltage under high vacuum up to 10 -5 Torr. The PEEK wires having the advantages of PEEK resin including superior radiation resistance and cryogenic characteristics are usable over a wide range of temperature and in radiation fields. The results of withstand voltage tests proved that the PEEK wires exceeding 0.8 mm in insulation thickness withstand such specified high voltage conditions as 24 kV for 1 minutes by 10 times and 6.6 kV for 110 hours. The results also revealed that the withstand voltage is improved by providing a jacket layer over the insulation and decreased by periodical voltage charge, by bending of the specimen and by water in the conductor. This paper deal with the withstand voltage test results under varied conditions of the PEEK wires. (author)

Sterilizing effects and lethal effects of gamma radiation on different phases of life cycle of the sitotroga cerealella (Olivier) in rice and maize

International Nuclear Information System (INIS)

Arthur, V.

1985-01-01

The objective of this research to verify the effects of the gamma radiation on different phases of the life cycle of the gamma radiation on different phases of the life cycle of the moth grain Angoumois, Sitotroga cerealella (Olivier, 1819). For all the treatment with gamma radiation a Cobalt-60 source type Gammabeam-650 was used and the activity was approximately 3.1 x 10 sup(14) Bq., with dose rate of 3.01 kGy per hour. The LD sub(100) of gamma radiation for eggs of insects reared in rice and maize were respectively 100 Gy and 125 Gy. The sterilizing doses in adults which were irradiated at immature phases (larvae and pupae) were 100 Gy and 200 Gy in rice and 150 Gy and 250 Gy in maize, respectively. The sterilizing doses for females and males in maize were respectively 350 Gy and 500 Gy. The LD sub(100) for adult females were 4500 Gy and 4750 Gy for males, both in rice. The LD sub(100), for adult reared on maize was 4750 Gy for both sexes. (author)

A novel detector based on dual-mode fiber polished half block's characteristics for sensitive monitorings of radiation and materials

International Nuclear Information System (INIS)

Saeed, Ghadirli

2005-01-01

Full text : The overlay index dependence characteristics of the power distribution between two modes of dual-mode fiber polished half blocks is studied. The heat dependence characteristics of a certain overlay index affects the modal power distributions at the input of interferometer sensors used for monitoring the sensitive heat radiation changes. The other fundamental applications such as material recognitions through the index dependence characteristics in the closed chambers is also suggested

Impact of phonon coupling on the radiative nuclear reaction characteristics

Directory of Open Access Journals (Sweden)

Achakovskiy Oleg

2016-01-01

Full Text Available The pygmy dipole resonance and photon strength functions (PSF in stable and unstable Ni and Sn isotopes are calculated within the microscopic self-consistent version of the extended theory of finite Fermi systems in the quasiparticle time blocking approximation. The approach includes phonon coupling (PC effects in addition to the standard QRPA approach. The Skyrme force SLy4 is used. A pygmy dipole resonance in 72Ni is predicted at the mean energy of 12.4 MeV exhausting 25.7% of the total energy-weighted sum rule. With our microscopic E1 PSFs in the EMPIRE 3.1 code, the following radiative nuclear reaction characteristics have been calculated for several stable and unstable even-even Sn and Ni isotopes: 1 neutron capture cross sections, 2 corresponding neutron capture gamma-spectra, 3 average radiative widths of neutron resonances. Here, three variants of the microscopic nuclear level density models have been used and a comparison with the phenomenological generalized superfluid model has been performed. In all the considered properties, including the recent experimental data for PSF in Sn isotopes, the PC contributions turned out to be significant, as compared with the QRPA one, and necessary to explain the available experimental data.

Worker protection, especially protection against radiation during repair work on nuclear power stations in the planning and licensing phases

International Nuclear Information System (INIS)

Berg, D.; Kirsch, H.; Knape, H.

1979-01-01

The Strahlenschutzverordnung (Regulation for Protection against Radiation) requires that the designers of a nuclear power plant take every possible step in regard to preventive measures for the protection against radiation, in order to keep the radiation exposure to maintenance personnel as low as possible. The guideline concerning preventive measures for radiation protection of maintenance personnel during the design phase of the plant, which has been released by BMI (Federal Ministry of the Interior) requires evidence from the applicant, which describe these preventive measures. These evidences will be presented commonly by the manufacturer and the operator. The operators of nuclear plants have the greatest interest in planning the prevantive measures for the protection against radiation during maintenance work to an optimum, besides the fulfillment of these evidences, due to the fact that they bear the responsibility for the effectiveness of these measures, and that an increased exposure of the personnel to radiation- and/or operational restrictions cannot be excluded at insufficient preventive measures. In order to fulfill above mentioned viewpoints, RWE has developed a strategy, which will be presented in this lecture. All activities which have to be performed during the design and construction phase will be specified. The preventive measures to be performed during the design and construction of nuclear power plants will be persecuted in three parallel and independently from each other proceeded settlement levels: Settlement of the licensing procedure, general settlement of orders, model settlement. (orig./RW) [de

Thermal radiation characteristics and direct evidence of tungsten cooling on the way to nanostructure formation on its surface

Energy Technology Data Exchange (ETDEWEB)

Takamura, S., E-mail: takamura@aitech.ac.jp [Faculty of Engineering, Aichi Institute of Technology, Yakusa-cho, Toyota 470-0392 (Japan); Miyamoto, T. [Faculty of Engineering, Aichi Institute of Technology, Yakusa-cho, Toyota 470-0392 (Japan); Ohno, N. [Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

2013-07-15

The physical properties of tungsten with nanostructure on its surface are investigated focusing on the thermal radiation and cooling characteristics. First, direct evidence of substantial W surface cooling has been clearly shown with use of a very thin thermocouple inserted into W target, which solves an uncertainty associated with a radiation thermometer. Second, the above measurements of W surface temperature make it possible to estimate quantitatively the total emissivity from which we may evaluate the radiative power through the Stefan–Boltzmann equation, which is very important for mitigation evaluation of a serious plasma heat load to the plasma-facing component.

Thermal radiation characteristics and direct evidence of tungsten cooling on the way to nanostructure formation on its surface

International Nuclear Information System (INIS)

Takamura, S.; Miyamoto, T.; Ohno, N.

2013-01-01

The physical properties of tungsten with nanostructure on its surface are investigated focusing on the thermal radiation and cooling characteristics. First, direct evidence of substantial W surface cooling has been clearly shown with use of a very thin thermocouple inserted into W target, which solves an uncertainty associated with a radiation thermometer. Second, the above measurements of W surface temperature make it possible to estimate quantitatively the total emissivity from which we may evaluate the radiative power through the Stefan–Boltzmann equation, which is very important for mitigation evaluation of a serious plasma heat load to the plasma-facing component

Misonidazole and unconventional radiation in advanced squamous cell carcinoma of the esophagus: a phase II study of the Radiation Therapy Oncology Group

International Nuclear Information System (INIS)

Ydrach, A.A.; Marcial, V.A.; Parsons, J.; Concannon, J.; Asbell, S.O.; George, F.

1982-01-01

This is a report on Radiation Therapy Oncology Group (RTOG) Protocol78-32, a Phase I/II prospective study aimed at determining tolerance, tumor response, and survival of squamous cell carcinoma of the esophagus treated with unorthodox fractionation radiotherapy combined with misonidazole. Misonidazole was administered by mouth 4 to 6 hr prior to radiation, at a dose of 1.0 to 1.25 Gm/.m 2 ; blood levels were measured at about 4 hr after intake of the drug and reported in micrograms/ml. Radiotherapy was administered at 4 to 6 hr post-misonidazole dose and given with 400 rad fractions, alternating 2 or 3 times/week, up to 4,800 rad. A total of 43 patients were entered; 26 are evaluated for survival at 1 year post accession. Thirty patients (88%) received the planned radiation course. Twenty-eight patients (78%) received the planned misonidazole dosage. Tumor response, evaluated in 18 patients, showed a complete regression (C.R.) in only 2 patients (11%); and partial response (P.R.) in 6 patients (33%). Eight patients (44%) showed no tumor response to planned therapy. Toxicity was acceptable and in 38 evaluated patients only 4 reported (11%) nausea and vomiting, 7 reported mild paresthesias (18%). The median survival was only five months. In 26 patients evaluated for 1 year survival determination, only 1 survived (3.8%) this period. In view of the poor tumor response and low survival observed, we do not recommend that this particular fractionation regimen with misonidazole be used in a Phase III randomized trial in squamous cell carcinoma of the esophagus

radiation and electric field induced effects on the order-disorder phase in lithium sodium sulphate crystals

Science.gov (United States)

Hamed, A. E.; Kassem, M. E.; El-Wahidy, E. F.; El-Abshehy, M. A.

1995-03-01

The temperature dependence of specific heat at constant pressure, Cp(T), has been measured for lithium sodium sulphate, LiNaSo4 crystals, at different ?-radiation doses and external bias electric field (Eb), in the temperature range 300-900 K. A nonlinear dependence of transition temperature, T1 and a remarkable change in the thermodynamic parameters, were obtained as the effect of both electric field and ?-radiation. The effect of ?-radiation doses on the phase transition in LiNaSO4 crystals was explained as due to an internal bias field, Eb, originating from the interaction of polar defects with the order parameter of the host lattice. The internal bias field effect on the behaviour of Cp(T) in LiNaSO4 crystals was similar to that of the external electric field (E).

Characteristic Assessments of the Phased Array UT System Developed by KHNP

Energy Technology Data Exchange (ETDEWEB)

Cho, Chan-Hee; Jee, Dong-Hyun; Lee, Tae-Hun; Yoo, Hyun-Ju [KHNP CRI, Daejeon (Korea, Republic of)

2016-10-15

The ultrasonic testing (UT) is an important one of the nondestructive examination methods which are used for the in-service inspection in the nuclear power plant. It is mainly used for the inspection of welds in piping and nozzle for many components. Technologies for the ultrasonic testing have been advanced for the reduction of inspection time and the increase of inspection reliability. In the manual ultrasonic testing system, it is not easy to compare the variation of inspection signals over time, because the data cannot be stored during the inspection. For the purpose of inspecting nuclear power components, the KHNP developed a phased array UT system including pulser-receiver, AD converter, beam-former, phased array probe, and scanner with 3-directional degree of freedom. Characteristics of the KHNP PA system and the results of acquired signals are described in detail in this paper.

Characteristic Assessments of the Phased Array UT System Developed by KHNP

International Nuclear Information System (INIS)

Cho, Chan-Hee; Jee, Dong-Hyun; Lee, Tae-Hun; Yoo, Hyun-Ju

2016-01-01

The ultrasonic testing (UT) is an important one of the nondestructive examination methods which are used for the in-service inspection in the nuclear power plant. It is mainly used for the inspection of welds in piping and nozzle for many components. Technologies for the ultrasonic testing have been advanced for the reduction of inspection time and the increase of inspection reliability. In the manual ultrasonic testing system, it is not easy to compare the variation of inspection signals over time, because the data cannot be stored during the inspection. For the purpose of inspecting nuclear power components, the KHNP developed a phased array UT system including pulser-receiver, AD converter, beam-former, phased array probe, and scanner with 3-directional degree of freedom. Characteristics of the KHNP PA system and the results of acquired signals are described in detail in this paper

Effects of radiation upon gastrointestinal motility

Institute of Scientific and Technical Information of China (English)

Mary F Otterson

2007-01-01

Whether due to therapeutic or belligerent exposure, the gastrointestinal effects of irradiation produce symptoms dreaded by a majority of the population. Nausea, vomiting, diarrhea and abdominal cramping are hallmarks of the prodromal phase of radiation sickness, occurring hours to days following radiation exposure. The prodromal phase is distinct from acute radiation sickness in that the absorptive, secretory and anatomic changes associated with radiation damage are not easily identifiable. It is during this phase of radiation sickness that gastrointestinal motility significantly changes. In addition, there is evidence that motor activity of the gut contributes to some of the acute and chronic effects of radiation.

Influence of crystal shapes on radiative fluxes in visible wavelength: ice crystals randomly oriented in space

Directory of Open Access Journals (Sweden)

P. Chervet

1996-08-01

Full Text Available Radiative properties of cirrus clouds are one of the major unsolved problems in climate studies and global radiation budget. These clouds are generally composed of various ice-crystal shapes, so we tried to evaluate effects of the ice-crystal shape on radiative fluxes. We calculated radiative fluxes of cirrus clouds with a constant geometrical depth, composed of ice crystals with different shapes (hexagonal columns, bullets, bullet-rosettes, sizes and various concentrations. We considered ice particles randomly oriented in space (3D case and their scattering phase functions were calculated by a ray-tracing method. We calculated radiative fluxes for cirrus layers for different microphysical characteristics by using a discrete-ordinate radiative code. Results showed that the foremost effect of the ice-crystal shape on radiative properties of cirrus clouds was that on the optical thickness, while the variation of the scattering phase function with the ice shape remained less than 3% for our computations. The ice-water content may be a better choice to parameterize the optical properties of cirrus, but the shape effect must be included.

ESTABLISHED MODES AND STATIC CHARACTERISTICS OF THREE-PHASE ASYNCHRONOUS MOTOR POWERED WITH SINGLE PHASE NETWORK

Directory of Open Access Journals (Sweden)

V. S. Malyar

2016-01-01

Full Text Available A mathematical model is developed to study the operation of three-phase asynchronous motor with squirrel-cage rotor when the stator winding is powered from a single phase network. To create a rotating magnetic field one of the phases is fed through the capacitor. Due to the asymmetry of power feed not only transients, but the steady-state regimes are dynamic, so they are described by differential equations in any coordinate system. Their study cannot be carried out with sufficient adequacy on the basis of known equivalent circuits and require the use of dynamic parameters. In the mathematical model the state equations of the circuits of the stator and rotor are composed in the stationary three phase coordinate system. Calculation of the established mode is performed by solving the boundary problem that makes it possible to obtain the coordinate dependences over the period, without calculation of the transient process. In order to perform it, the original nonlinear differential equations are algebraized by approximating the variables with the use of cubic splines. The resulting nonlinear system of algebraic equations is a discrete analogue of the initial system of differential equations. It is solved by parameter continuation method. To calculate the static characteristics as a function of a certain variable, the system is analytically differentiated, and then numerically integrated over this variable. In the process of integration, Newton's refinement is performed at each step or at every few steps, making it possible to implement the integration in just a few steps using Euler's method. Jacobi matrices in both cases are the same. To account for the current displacement in the rods of the squirrel-cage rotor, each of them, along with the squirrel-cage rings, is divided in height into several elements. This results in several squirrel-cage rotor windings which are represented by three-phase windings with magnetic coupling between them.

Inverse boundary design of a radiative smelting furnace with ablative phase change phenomena

International Nuclear Information System (INIS)

Farzan, H.; Hosseini Sarvari, S.M.; Mansouri, S.H.

2016-01-01

Highlights: • The ablation phenomenon in a reverberatory smelting furnace is simulated numerically. • The results are verified by comparing with exact analytic solution. • Inverse design problem is solved to construct the desired melting rate. • The conjugate gradient method is used to solve the inverse phase change problem. - Abstract: An inverse analysis is employed to control the time rate of heaters in a 2-D smelting furnace to provide the specified radiative heat flux across the design surface to establish a desired melting rate. The design surface in the smelting furnace is the melting surface of the metal concentrate bank, and the melting process is considered to occur as an ablation phenomenon. The net radiation method is used to determine the radiation exchange between the elements of the furnace surfaces and the melting surface. The conjugate gradient method is employed to minimize the objective function, which is the sum of square residuals between the estimated and the desired heat fluxes over the design surface. It is shown that the proposed inverse technique is reliable and accurate for predicting the heater power distribution.

A Novel Radiation Shielding Material, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — In order to safely explore space, humans must be protected from radiation. There are 2 predominant sources of extraterrestrial ionizing radiation, namely, Galactic...

Application of neural networks to prediction of phase transport characteristics in high-pressure two-phase turbulent bubbly flows

International Nuclear Information System (INIS)

Yang, A.-S.; Kuo, T.-C.; Ling, P.-H.

2003-01-01

The phase transport phenomenon of the high-pressure two-phase turbulent bubbly flow involves complicated interfacial interactions of the mass, momentum, and energy transfer processes between phases, revealing that an enormous effort is required in characterizing the liquid-gas flow behavior. Nonetheless, the instantaneous information of bubbly flow properties is often desired for many industrial applications. This investigation aims to demonstrate the successful use of neural networks in the real-time determination of two-phase flow properties at elevated pressures. Three back-propagation neural networks, trained with the simulation results of a comprehensive theoretical model, are established to predict the transport characteristics (specifically the distributions of void-fraction and axial liquid-gas velocities) of upward turbulent bubbly pipe flows at pressures covering 3.5-7.0 MPa. Comparisons of the predictions with the test target vectors indicate that the averaged root-mean-squared (RMS) error for each one of three back-propagation neural networks is within 4.59%. In addition, this study appraises the effects of different network parameters, including the number of hidden nodes, the type of transfer function, the number of training pairs, the learning rate-increasing ratio, the learning rate-decreasing ratio, and the momentum value, on the training quality of neural networks.

Experimental study on spray characteristics of alternate jet fuels using Phase Doppler Anemometry

Science.gov (United States)

Kannaiyan, Kumaran; Sadr, Reza

2013-11-01

Gas-to-Liquid (GTL) fuels have gained global attention due to their cleaner combustion characteristics. The chemical and physical properties of GTL jet fuels are different from conventional jet fuels owing to the difference in their production methodology. It is important to study the spray characteristics of GTL jet fuels as the change of physical properties can affect atomization, mixing, evaporation and combustion process, ultimately affecting emission process. In this work, spray characteristics of two GTL synthetic jet fuels are studied using a pressure-swirl nozzle at different injection pressures and atmospheric ambient condition. Phase Doppler Anemometry (PDA) measurements of droplet size and velocity are compared with those of regular Jet A-1 fuel at several axial and radial locations downstream of the nozzle exit. Experimental results show that although the GTL fuels have different physical properties such as viscosity, density, and surface tension, among each other the resultant change in the spray characteristics is insignificant. Furthermore, the presented results show that GTL fuel spray characteristics exhibit close similarity to those of Jet A-1 fuel. Funded by Qatar Science and Technology Park.

Spectrally resolved modal characteristics of leaky-wave-coupled quantum cascade phase-locked laser arrays

Science.gov (United States)

Sigler, Chris; Gibson, Ricky; Boyle, Colin; Kirch, Jeremy D.; Lindberg, Donald; Earles, Thomas; Botez, Dan; Mawst, Luke J.; Bedford, Robert

2018-01-01

The modal characteristics of nonresonant five-element phase-locked arrays of 4.7-μm emitting quantum cascade lasers (QCLs) have been studied using spectrally resolved near- and far-field measurements and correlated with results of device simulation. Devices are fabricated by a two-step metal-organic chemical vapor deposition process and operate predominantly in an in-phase array mode near threshold, although become multimode at higher drive levels. The wide spectral bandwidth of the QCL's core region is found to be a factor in promoting multispatial-mode operation at high drive levels above threshold. An optimized resonant-array design is identified to allow sole in-phase array-mode operation to high drive levels above threshold, and indicates that for phase-locked laser arrays full spatial coherence to high output powers does not require full temporal coherence.

Numerical Analysis of Flow and Heat Transfer Characteristics of CO2 at Vapour and Supercritical Phases in Micro-Channels

Directory of Open Access Journals (Sweden)

Rao N.T.

2016-01-01

Full Text Available Supercritical carbon dioxide (CO2 has special thermal properties with better heat transfer and flow characteristics. Due to this reason, supercritical CO2 is being used recently in air-condition and refrigeration systems to replace non environmental friendly refrigerants. Even though many researches have been done, there are not many literatures for heat transfer and flow characteristics of supercritical CO2. Therefore, the main purpose of this study is to develop flow and heat transfer CFD models on two different phases; vapour and supercritical of CO2 to investigate the heat transfer characteristics and pressure drop in micro-channels. CO2 is considered to be in different phases with different flow pressures but at same temperature. For the simulation, the CO2 flow was assumed to be turbulent, nonisothermal and Newtonian. The numerical results for both phases are compared. From the numerical analysis, for both vapour and supercritical phases, the heat energy from CO2 gas transferred to water to attain thermal equilibrium. The temperature of CO2 at vapour phase decreased 1.78% compared to supercritical phase, which decreased for 0.56% from the inlet temperature. There was a drastic increase of 72% for average Nu when the phase changed from vapour to supercritical. The average Nu decreased rapidly about 41% after total pressure of 9.0 MPa. Pressure drop (ΔP increased together with Reynolds number (Re for vapour and supercritical phases. When the phase changed from vapour to supercritical, ΔP was increased about 26%. The results obtained from this study can provide information for further investigations on supercritical CO2.

Active Radiation Shield, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — DEC-Shield technology offers the means to generate electric power from cosmic radiation sources and fuse dissimilar systems and functionality into a structural...

Effects of nuclear radiation on a high-reliability silicon power diode. 4: Analysis of reverse bias characteristics

Science.gov (United States)

Been, J. F.

1973-01-01

The effects of nuclear radiation on the reverse bias electrical characteristics of one hundred silicon power diodes were investigated. On a percentage basis, the changes in reverse currents were large but, due to very low initial values, this electrical characteristic was not the limiting factor in use of these diodes. These changes were interpreted in terms of decreasing minority carrier lifetimes as related to generation-recombination currents. The magnitudes of reverse voltage breakdown were unaffected by irradiation.

Intelligent Radiative Materials, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — An opportunity to boost energy efficiency in homes and buildings exists through the design of functional radiative properties in glass and other building materials....

Influence of radiation on photo-electric characteristics of silicon photo cells with optical coverings

International Nuclear Information System (INIS)

Madatov, R.S.; Safarov, N.A.; Gasymova, V.G.; Abdurragimov, A.A.; Allahverdiev, A.M.

2003-01-01

In the given work results of measurements volt-ampere and spectral characteristics of silicon photo cells with optical coverings ZnS+Nd 2 O 3 irradiated accelerated electrons with energy 4.5 MeV are carried out. Elements have been made by diffusion of phosphorus in p-silicon with specific resistance 2 Ω·cm. Under condition of illumination from source AMI the photocurrent of short circuit made 40 mA/cm 2 , and a photo voltage of idling 0.52 V, efficiency made 15 %. To receive low reflection in wide area of spectral sensitivity and by that as much as possible to increase efficiency of elements with the help of two-layer coverings. The irradiation of samples was made on linear accelerator EL4-6 at room temperature. It is received, that with increase in a dose of an irradiation the Photocurrent and photo voltage decreases, and speed reduction of a photo-current is stronger, than photo voltage. The critical integrated stream for these elements makes 4·10 12 el/cm 2 . In all researched samples radiating reduction of a voltage of idling in an interval of 10 10 -10 14 el/cm 2 makes 8-10 %. The analysis of spectral characteristics of the irradiated samples show, that reduction of a photocurrent in long-wave areas of a spectrum is connected by creation of radiating defects in a base part of an element. The increase in a critical stream in silicon solar elements with optical a covering in comparison with elements without a covering is connected with low concentration of defects in the base, created with electron. Thus, on the basis of complex research of influence on radiating stability silicon solar elements us it is established, that two-layer coverings not only increases efficiency of photo cells, but also considerably raise value of an integrated stream electrons, that is equivalent to increase in service life of the elements working in conditions of radiation

Assessment of the Radiation-Equivalent of Chemotherapy Contributions in 1-Phase Radio-chemotherapy Treatment of Muscle-Invasive Bladder Cancer

International Nuclear Information System (INIS)

Plataniotis, George A.; Dale, Roger G.

2014-01-01

Purpose: To estimate the radiation equivalent of the chemotherapy contribution to observed complete response rates in published results of 1-phase radio-chemotherapy of muscle-invasive bladder cancer. Methods and Materials: A standard logistic dose–response curve was fitted to data from radiation therapy-alone trials and then used as the platform from which to quantify the chemotherapy contribution in 1-phase radio-chemotherapy trials. Two possible mechanisms of chemotherapy effect were assumed (1) a fixed radiation-independent contribution to local control; or (2) a fixed degree of chemotherapy-induced radiosensitization. A combination of both mechanisms was also considered. Results: The respective best-fit values of the independent chemotherapy-induced complete response (CCR) and radiosensitization (s) coefficients were 0.40 (95% confidence interval −0.07 to 0.87) and 1.30 (95% confidence interval 0.86-1.70). Independent chemotherapy effect was slightly favored by the analysis, and the derived CCR value was consistent with reports of pathologic complete response rates seen in neoadjuvant chemotherapy-alone treatments of muscle-invasive bladder cancer. The radiation equivalent of the CCR was 36.3 Gy. Conclusion: Although the data points in the analyzed radio-chemotherapy studies are widely dispersed (largely on account of the diverse range of chemotherapy schedules used), it is nonetheless possible to fit plausible-looking response curves. The methodology used here is based on a standard technique for analyzing dose-response in radiation therapy-alone studies and is capable of application to other mixed-modality treatment combinations involving radiation therapy

Heterogeneity in cytokinetic, clonogenic, and radiation response induced by nutrient deprivation

International Nuclear Information System (INIS)

Grdina, D.J.; Williamson, K.D.; Johnson, T.S.; Sigdestad, C.P.

1986-01-01

A murine fibrosarcoma cell line (FSA 1233), with a capability to grow in vitro, was used to study biophysical heterogeneity induced by nutrient deprivation. Cell sub-populations were isolated by centrifuging cells through linear Renografin-density gradients. The effects of cell growth to late plateau phase on the cytokinetic, clonogenic, and radiation-survival characteristics were studied. It was observed that with increasing age of the cell culture, an increase in the proportion of relatively dense cells was associated with a decrease in plating efficiency. Cells collected at p=1.08 g/cm 3 have a plating efficiency of 0.2% compared with 0.01% for those isolated at p=1.16 g/cm 3 . Discrepancies were also seen between the tritiated thymidine labeling index (LI) and flow cytometry (FCM, % S phase) for cells collected throughout the gradient. The radiation sensitivities of selected cell populations isolated by density gradient centrifugation were determined and compared with data from a control plateau phase population. 15 refs., 4 figs., 1 tab

Scrutinization of thermal radiation, viscous dissipation and Joule heating effects on Marangoni convective two-phase flow of Casson fluid with fluid-particle suspension

Science.gov (United States)

Mahanthesh, B.; Gireesha, B. J.

2018-03-01

The impact of Marangoni convection on dusty Casson fluid boundary layer flow with Joule heating and viscous dissipation aspects is addressed. The surface tension is assumed to vary linearly with temperature. Physical aspects of magnetohydrodynamics and thermal radiation are also accounted. The governing problem is modelled under boundary layer approximations for fluid phase and dust particle phase and then Runge-Kutta-Fehlberg method based numeric solutions are established. The momentum and heat transport mechanisms are focused on the result of distinct governing parameters. The Nusselt number is also calculated. It is established that the rate of heat transfer can be enhanced by suspending dust particles in the base fluid. The temperature field of fluid phase and temperature of dust phase are quite reverse for thermal dust parameter. The radiative heat, viscous dissipation and Joule heating aspects are constructive for thermal fields of fluid and dust phases. The velocity of dusty Casson fluid dominates the velocity of dusty fluid while this trend is opposite in the case of temperature. Moreover qualitative behaviour of fluid phase and dust phase temperature/velocity are similar.

Physiological-phased kinetic characteristics of microalgae Chlorella vulgaris growth and lipid synthesis considering synergistic effects of light, carbon and nutrients.

Science.gov (United States)

Liao, Qiang; Chang, Hai-Xing; Fu, Qian; Huang, Yun; Xia, Ao; Zhu, Xun; Zhong, Nianbing

2018-02-01

To comprehensively understand kinetic characteristics of microalgae growth and lipid synthesis in different phases, a phase-feeding strategy was proposed to simultaneously regulate light, carbon and nutrients in adaption, growth and stationary phases of microalgae cultivation. Physiological-phased kinetic characteristics of microalgae Chlorella vulgaris growth and lipid synthesis under synergistic effects of light, carbon and nutrients were investigated, and supply-demand relationships of electrons and energy between light and dark reactions of photosynthesis process were discussed. Finally, the optimized cultivation strategy for microalgae in various phases were obtained, under which the lipid productivity was significantly improved from 130.11 mg/L/d to 163.42 mg/L/d. The study provided some important guidance for the large-scale production of biofuels from microalgae. Copyright © 2017 Elsevier Ltd. All rights reserved.

Some physico-chemical characteristics of a modified histone H2b on acute radiation affection

International Nuclear Information System (INIS)

Khrapunov, S.N.; Mel'nik, G.G.; Blyum, Ya.B.; Tsudzevich, B.A.; Kucherenko, N.E.

1980-01-01

A study was made of optical characteristics of histone H2b isolated from liver nuclei 12 h following irradiation in a dose of 0.21 C/kg. It was demonstrated that under similar conditions, the control and exposed histones H2b have different steric organization which correlates with radiation-induced modifications of lateral radicals in H2b histone molecules

Environmental Radiation Monitoring In The Chernobyl Exclusion Zone - History And Results 25 Years After

International Nuclear Information System (INIS)

Farfan, E.; Jannik, T.

2011-01-01

This article describes results of the radiation environmental monitoring performed in the Chernobyl Exclusion Zone (ChEZ) during the period following the 1986 Chernobyl Nuclear Power Plant accident. This article presents a brief overview of five comprehensive reports generated under Contract No. DE-AC09-96SR18500 (Washington Savannah River Company LLC, Subcontract No. AC55559N, SOW No. ON8778) and summarizes characteristics of the ChEZ and its post-accident status and the history of development of the radiation monitoring research in the ChEZ is described. This article addresses characteristics of the radiation monitoring in the ChEZ, its major goals and objectives, and changes of these goals and objectives in the course of time, depending on the tasks associated with the phase of mitigation of the ChNPP accident consequences. The results of the radiation monitoring in the ChEZ during the last 25 years are also provided.

ENVIRONMENTAL RADIATION MONITORING IN THE CHERNOBYL EXCLUSION ZONE - HISTORY AND RESULTS 25 YEARS AFTER

Energy Technology Data Exchange (ETDEWEB)

Farfan, E.; Jannik, T.

2011-10-01

This article describes results of the radiation environmental monitoring performed in the Chernobyl Exclusion Zone (ChEZ) during the period following the 1986 Chernobyl Nuclear Power Plant accident. This article presents a brief overview of five comprehensive reports generated under Contract No. DE-AC09-96SR18500 (Washington Savannah River Company LLC, Subcontract No. AC55559N, SOW No. ON8778) and summarizes characteristics of the ChEZ and its post-accident status and the history of development of the radiation monitoring research in the ChEZ is described. This article addresses characteristics of the radiation monitoring in the ChEZ, its major goals and objectives, and changes of these goals and objectives in the course of time, depending on the tasks associated with the phase of mitigation of the ChNPP accident consequences. The results of the radiation monitoring in the ChEZ during the last 25 years are also provided.

Foam radiators for transition radiation detectors

International Nuclear Information System (INIS)

Chernyatin, V.; Dolgoshein, B.; Gavrilenko, I.; Potekhin, M.; Romaniouk, A.; Sosnovtsev, V.

1993-01-01

A wide variety of foam radiators, potentially useful in the design of a transition radiation detector, the possible particle identification tool in collider experiments, have been tested in the beam. Various characteristics of these radiators are compared, and the conclusion is reached that certain brands of polyethylene foam are best suited for use in the detector. Comparison is made with a 'traditional' radiator, which is a periodic structure of plastic foils. (orig.)

X-ray diffraction characteristics of curved monochromators for sychrotron radiation

International Nuclear Information System (INIS)

Boeuf, A.; Rustichelli, F.; Mazkedian, S.; Puliti, P.; Melone, S.

1978-01-01

A theoretical study is presented concerning the diffraction characteristics of curved monochromators for X-ray synchrotron radiation used at the laboratories of Hamburg, Orsay and Stanford. The investigation was performed by extending to the X-ray case a simple model recently developed and fruitfully employed to describe the neutron diffraction properties of curved monochromators. Several diffraction patterns were obtained corresponding to different monochromator materials (Ge, Si) used by the different laboratories, for different reflecting planes (111), (220), asymmetry angles, X-ray wave-lengths (Mo Kα, Cu Kα, Cr Kα) and curvature radii. The results are discussed in physical terms and their implications on the design of curved monochromators for synchrotron radiation are presented. In particular, the study shows that all the monochromators used in the different laboratories should behave practically as perfect crystals and therefore should have a very low integrated reflectivity corresponding to an optimized wavelength passband Δlambda/lambda approximately 10 -4 . The gain that can be obtained by increasing the curvature, by introducing a gradient in the lattice spacing or by any other kind of imperfection is quite limited and much lower than the desirable value. The adopted model can help in obtaining a possible moderate gain in intensity by also taking into consideration other parameters, such as crystal material, reflecting plane, asymmetry of the reflection and X-ray wavelength. (Auth.)

Cell cycle phase dependent role of DNA polymerase beta in DNA repair and survival after ionizing radiation.

NARCIS (Netherlands)

Vermeulen, C.; Verwijs-Janssen, M.; Begg, A.C.; Vens, C.

2008-01-01

PURPOSE: The purpose of the present study was to determine the role of DNA polymerase beta in repair and response after ionizing radiation in different phases of the cell cycle. METHODS AND MATERIALS: Synchronized cells deficient and proficient in DNA polymerase beta were irradiated in different

Radiation effect on partially synchronized Yoshida sarcoma cells

International Nuclear Information System (INIS)

Bippus, P.H.; Heitz, J.; Ruehl, U.; Averdunk, R.

1982-01-01

Yoshida sarcoma cells, which have the same growth characteristics as ascites cells in the mouse and in cell suspension, were partially synchronized in vitro by means of excess thymidine (0.1 mM thymidine for 18 h). The growth of non-synchronized cultures was inhibited by irradiation, the degree depending on the dose of radiation. At the same time, a 50% inhibition in vivo (380 rad) and in vitro (480 rad) was determined. The incorporation of 3 H-thymidine into the DNA is inhibited by 10-32%, depending on the radiation dose. The mitotic index decreases 2 h after irradiation by a dose-dependent amount. A mitotic maximum develops later; the delay is dose-dependent. Partially synchronized cells were irradiated in the G 1 /S-, S-, G 2 -, and G 1 -phase. As compared to the 3 H-thymidine incorporation and the mitotic index there were no significant differences between the cultures which were irradiated in the individual phases of the non-synchronized control cultures. The cultures which were irradiated in the G 2 -phase, however, showed a significantly reduced growth in vivo after 48 h. If the cells were cultured for more than 72 h after irradiation, the differences between the cultures irradiated in the G 2 -phase and the other phases were reduced. (orig.)

Conceptualisation of the characteristics of advanced practitioners in the medical radiation professions

Energy Technology Data Exchange (ETDEWEB)

Smith, Tony [University of Newcastle Department of Rural Health, Taree, New South Wales (Australia); Harris, Jillian [Crown Princess Mary Cancer Centre, Westmead, Sydney, New South Wales (Australia); Woznitza, Nick [Homerton University Hospital and School of Allied Health Professions, Canterbury Christ Church University, Canterbury (Australia); Maresse, Sharon [Department of Imaging and Applied Physics, Curtin University, Perth, Western Australia (Australia); Sale, Charlotte [School of Medical Science, RMIT University, Melbourne, Victoria (Australia); University of Newcastle Department of Rural Health, Taree, New South Wales (Australia)

2015-09-15

Professions grapple with defining advanced practice and the characteristics of advanced practitioners. In nursing and allied health, advanced practice has been defined as ‘a state of professional maturity in which the individual demonstrates a level of integrated knowledge, skill and competence that challenges the accepted boundaries of practice and pioneers new developments in health care’. Evolution of advanced practice in Australia has been slower than in the United Kingdom, mainly due to differences in demography, the health system and industrial relations. This article describes a conceptual model of advanced practitioner characteristics in the medical radiation professions, taking into account experiences in other countries and professions. Using the CanMEDS framework, the model includes foundation characteristics of communication, collaboration and professionalism, which are fundamental to advanced clinical practice. Gateway characteristics are: clinical expertise, with high level competency in a particular area of clinical practice; scholarship and teaching, including a masters qualification and knowledge dissemination through educating others; and evidence-based practice, with judgements made on the basis of research findings, including research by the advanced practitioner. The pinnacle of advanced practice is clinical leadership, where the practitioner has a central role in the health care team, with the capacity to influence decision making and advocate for others, including patients. The proposed conceptual model is robust yet adaptable in defining generic characteristics of advanced practitioners, no matter their clinical specialty. The advanced practice roles that evolve to meet future health service demand must focus on the needs of patients, local populations and communities.

Conceptualisation of the characteristics of advanced practitioners in the medical radiation professions

International Nuclear Information System (INIS)

Smith, Tony; Harris, Jillian; Woznitza, Nick; Maresse, Sharon; Sale, Charlotte

2015-01-01

Professions grapple with defining advanced practice and the characteristics of advanced practitioners. In nursing and allied health, advanced practice has been defined as ‘a state of professional maturity in which the individual demonstrates a level of integrated knowledge, skill and competence that challenges the accepted boundaries of practice and pioneers new developments in health care’. Evolution of advanced practice in Australia has been slower than in the United Kingdom, mainly due to differences in demography, the health system and industrial relations. This article describes a conceptual model of advanced practitioner characteristics in the medical radiation professions, taking into account experiences in other countries and professions. Using the CanMEDS framework, the model includes foundation characteristics of communication, collaboration and professionalism, which are fundamental to advanced clinical practice. Gateway characteristics are: clinical expertise, with high level competency in a particular area of clinical practice; scholarship and teaching, including a masters qualification and knowledge dissemination through educating others; and evidence-based practice, with judgements made on the basis of research findings, including research by the advanced practitioner. The pinnacle of advanced practice is clinical leadership, where the practitioner has a central role in the health care team, with the capacity to influence decision making and advocate for others, including patients. The proposed conceptual model is robust yet adaptable in defining generic characteristics of advanced practitioners, no matter their clinical specialty. The advanced practice roles that evolve to meet future health service demand must focus on the needs of patients, local populations and communities

Optical properties of Pb-based aggregated phases in CsBr crystal

Energy Technology Data Exchange (ETDEWEB)

Voloshinovskii, A. [Ivan Franko National University of Lviv, 8 Kyryla i Mefodiya Str., 79005 Lviv (Ukraine); Myagkota, S. [Ivan Franko National University of Lviv, 8 Kyryla i Mefodiya Str., 79005 Lviv (Ukraine); Garapyn, I. [Ivan Franko National University of Lviv, 8 Kyryla i Mefodiya Str., 79005 Lviv (Ukraine); Stryganyuk, G. [Ivan Franko National University of Lviv, 8 Kyryla i Mefodiya Str., 79005 Lviv (Ukraine); Rodnyi, P. [St. Petersburg State Polytechnical University, 29 Polyteknicheskaya Str., 195251 St. Petersburg (Russian Federation); Eijk, C.W.E. van [Interfaculty Reactor Institute, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands)]. E-mail: vaneijk@iri.tudelft.nl

2005-01-01

The emission and excitation spectra as well as luminescence decay kinetics of a CsBr:Pb (1.0mol%) crystal have been measured under pulsed synchrotron radiation excitation. The heat-treated ({approx}200 deg. C) crystal shows evidence of single lead centres and aggregated phases such as CsPbBr3 nanocrystals. The latter have been identified from comparison of the spectral-kinetic characteristics of the CsPbBr3 aggregated phases and single crystals. The process of energy transfer from the host to the aggregates is considered.

Optical properties of Pb-based aggregated phases in CsBr crystal

International Nuclear Information System (INIS)

Voloshinovskii, A.; Myagkota, S.; Garapyn, I.; Stryganyuk, G.; Rodnyi, P.; Eijk, C.W.E. van

2005-01-01

The emission and excitation spectra as well as luminescence decay kinetics of a CsBr:Pb (1.0mol%) crystal have been measured under pulsed synchrotron radiation excitation. The heat-treated (∼200 deg. C) crystal shows evidence of single lead centres and aggregated phases such as CsPbBr3 nanocrystals. The latter have been identified from comparison of the spectral-kinetic characteristics of the CsPbBr3 aggregated phases and single crystals. The process of energy transfer from the host to the aggregates is considered

Characteristics of the radiation prevention metrology laboratory 'Cajavec' - Banjaluka

International Nuclear Information System (INIS)

Tomljenovic, I.; Ninkovic, M.; Kolonic, Dz.

2004-01-01

Radiation metrology laboratory built in the factory 'Cajavec' in Banja Luka, planed for gauge the detectors of ionization radiation. Laboratory as part of the large factory building , thus projected and formed according to positive radiation principles. Walls are constructed of basic concrete, main entrance of lead, approaching the radiation bench from the back side. Sound and light signal system connected with dosemeter for showing mini dose of radiation creating conditions for safe work of the dosemeterists. (author) [sr

Phase II Results of RTOG 0537: A Phase II/III Study Comparing Acupuncture-like Transcutaneous Electrical Nerve Stimulation Versus Pilocarpine in Treating Early Radiation-Induced Xerostomia

Science.gov (United States)

Wong, Raimond K. W.; James, Jennifer L.; Sagar, Stephen; Wyatt, Gwen; Nguyen-Tân, Phuc Felix; Singh, Anurag K.; Lukaszczyk, Barbara; Cardinale, Francis; Yeh, Alexander M.; Berk, Lawrence

2011-01-01

Purpose This phase II component of a multi-institutional phase II/III randomized trial assessed the feasibility and preliminary efficacy of acupuncture-like transcutaneous electrical nerve stimulation (ALTENS) in reducing radiation-induced xerostomia. Methods Head and neck cancer patients who were 3–24 months from completing radiotherapy ± chemotherapy (RT±C) and experiencing xerostomia symptoms with basal whole saliva production ≥0.1 ml/min and without recurrence were eligible. Patients received twice weekly ALTENS sessions (24 over 12 weeks) using a Codetron™ unit. The primary objective assessed the feasibility of ALTENS treatment. A patient was considered compliant if 19/24 ALTENS were delivered, with a targeted 85% compliance rate. Secondary objectives measured treatment-related toxicities and ALTENS effect on overall radiation-induced xerostomia burden using the University of Michigan Xerostomia-Related Quality of Life Scale (XeQOLS). Results Of 48 accrued patients, 47 were evaluable. Median age was 60 years; 84% were male, 70% completed RT±C for > 12 months and 21% had received prior pilocarpine. All ALTENS sessions were completed in 34 patients, but 9 and 1 completed 20–23 and 19 sessions respectively, representing a 94% total compliance rate. 6-month XeQOLS scores were available for 35 patients; 30 (86%) achieved a positive treatment response with a mean reduction of 35.9% (SD 36.1). Five patients developed grade 1–2 gastrointestinal toxicity and one had grade 1 pain event. Conclusions ALTENS treatment for radiation-induced xerostomia can be uniformly delivered in a cooperative multicenter setting and has possible beneficial treatment response. Given these results, the phase III component of this study was initiated. PMID:22252927

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

International Nuclear Information System (INIS)

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

An analysis of the radiation field characteristics for extremity dose assessment during maintenance periods at nuclear power plants in Korea

International Nuclear Information System (INIS)

Kim, H. G.; Kong, T. Y.

2012-01-01

Workers who maintain the water chambers of steam generators during maintenance periods in nuclear power plants (NPPs) have a higher likelihood of high radiation exposure, even if they are exposed for a short period of time. In particular, it is expected that the hands of workers would receive the highest radiation exposure as a consequence of hand contact with radioactive materials. In this study, a characteristic analysis of inhomogeneous radiation fields for contact operations was conducted using thermoluminescent dosemeters for the whole body and extremities during maintenance periods at Korean NPPs. It was observed that inhomogeneous radiation fields for contact operations at NPPs were dominated by high-energy photons. (authors)

Effect of physiological age on radiation resistance of some bacteria that are highly radiation resistant

International Nuclear Information System (INIS)

Keller, L.C.; Maxcy, R.B.

1984-01-01

Physiological age-dependent variation in radiation resistance was studied for three bacteria that are highly radiation resistant: Micrococcus radiodurans, Micrococcus sp. isolate C-3, and Moraxella sp. isolate 4. Stationary-phase cultures of M. radiodurans and isolate C-3 were much more resistant to gamma radiation than were log-phase cultures. This pattern of relative resistance was reversed for isolate 4. Resistance of isolate 4 to UV light was also greater during log phase, although heat resistance and NaCl tolerance after heat stresses were greater during stationary phase. Radiation-induced injury of isolate 4 compared with injury of Escherichia coli B suggested that the injury process, as well as the lethal process, was affected by growth phase. The hypothesis that growth rate affects radiation resistance was tested, and results were interpreted in light of the probable confounding effect of methods used to alter growth rates of bacteria. These results indicate that dose-response experiments should be designed to measure survival during the most resistant growth phase of the organism under study. The timing is particularly important when extrapolations of survival results might be made to potential irradiation processes for foods. 17 references

Hepatic arterial phase and portal venous phase computed tomography for dose calculation of stereotactic body radiation therapy plans in liver cancer: a dosimetric comparison study

International Nuclear Information System (INIS)

Xiao, Jianghong; Li, Yan; Jiang, Qingfeng; Sun, Lan; Henderson Jr, Fraser; Wang, Yongsheng; Jiang, Xiaoqin; Li, Guangjun; Chen, Nianyong

2013-01-01

To investigate the effect of computed tomography (CT) using hepatic arterial phase (HAP) and portal venous phase (PVP) contrast on dose calculation of stereotactic body radiation therapy (SBRT) for liver cancer. Twenty-one patients with liver cancer were studied. HAP, PVP and non-enhanced CTs were performed on subjects scanned in identical positions under active breathing control (ABC). SBRT plans were generated using seven-field three-dimensional conformal radiotherapy (7 F-3D-CRT), seven-field intensity-modulated radiotherapy (7 F-IMRT) and single-arc volumetric modulated arc therapy (VMAT) based on the PVP CT. Plans were copied to the HAP and non-enhanced CTs. Radiation doses calculated from the three phases of CTs were compared with respect to the planning target volume (PTV) and the organs at risk (OAR) using the Friedman test and the Wilcoxon signed ranks test. SBRT plans calculated from either PVP or HAP CT, including 3D-CRT, IMRT and VMAT plans, demonstrated significantly lower (p <0.05) minimum absorbed doses covering 98%, 95%, 50% and 2% of PTV (D98%, D95%, D50% and D2%) than those calculated from non-enhanced CT. The mean differences between PVP or HAP CT and non-enhanced CT were less than 2% and 1% respectively. All mean dose differences between the three phases of CTs for OARs were less than 2%. Our data indicate that though the differences in dose calculation between contrast phases are not clinically relevant, dose underestimation (IE, delivery of higher-than-intended doses) resulting from CT using PVP contrast is larger than that resulting from CT using HAP contrast when compared against doses based upon non-contrast CT in SBRT treatment of liver cancer using VMAT, IMRT or 3D-CRT

Radiation effects on the current-voltage and capacitance-voltage characteristics of advanced p-n junction diodes surrounded by shallow trench isolation

International Nuclear Information System (INIS)

Poyai, A.; Simoen, E.; Claeys, C.; Hayama, K.; Kobayashi, K.; Ohyama, H.

2002-01-01

This paper investigates the impact of 20 MeV proton irradiation on the current-voltage (I-V) and capacitance-voltage (C-V) characteristics of different geometry n + -p-well junction diodes surrounded by shallow trench isolation and processed in a 0.18 μm CMOS technology. From I-V characteristics, a higher current damage coefficient was found for the bulk than for the peripheral component. The radiation-induced boron de-activation resulted in a lowering of the p-well doping, which has been derived from high-frequency C-V measurements. This was confirmed by deep level transient spectroscopy (DLTS) analysis, revealing the presence of interstitial boron related radiation defects. As will be demonstrated for the bulk leakage-current damage coefficient, the electric field enhanced generation rate of charge carriers and the radiation-induced boron de-activation should be accounted for properly

Ionizing radiation

International Nuclear Information System (INIS)

Dennis, J.A.

1982-01-01

The subject is discussed under the headings: characteristics of ionizing radiations; biological effects; comparison of radiation and other industrial risks; principles of protection; cost-benefit analysis; dose limits; the control and monitoring of radiation; reference levels; emergency reference levels. (U.K.)

Deep Learning Identifies High-z Galaxies in a Central Blue Nugget Phase in a Characteristic Mass Range

Science.gov (United States)

Huertas-Company, M.; Primack, J. R.; Dekel, A.; Koo, D. C.; Lapiner, S.; Ceverino, D.; Simons, R. C.; Snyder, G. F.; Bernardi, M.; Chen, Z.; Domínguez-Sánchez, H.; Lee, C. T.; Margalef-Bentabol, B.; Tuccillo, D.

2018-05-01

We use machine learning to identify in color images of high-redshift galaxies an astrophysical phenomenon predicted by cosmological simulations. This phenomenon, called the blue nugget (BN) phase, is the compact star-forming phase in the central regions of many growing galaxies that follows an earlier phase of gas compaction and is followed by a central quenching phase. We train a convolutional neural network (CNN) with mock “observed” images of simulated galaxies at three phases of evolution— pre-BN, BN, and post-BN—and demonstrate that the CNN successfully retrieves the three phases in other simulated galaxies. We show that BNs are identified by the CNN within a time window of ∼0.15 Hubble times. When the trained CNN is applied to observed galaxies from the CANDELS survey at z = 1–3, it successfully identifies galaxies at the three phases. We find that the observed BNs are preferentially found in galaxies at a characteristic stellar mass range, 109.2–10.3 M ⊙ at all redshifts. This is consistent with the characteristic galaxy mass for BNs as detected in the simulations and is meaningful because it is revealed in the observations when the direct information concerning the total galaxy luminosity has been eliminated from the training set. This technique can be applied to the classification of other astrophysical phenomena for improved comparison of theory and observations in the era of large imaging surveys and cosmological simulations.

Radiative characteristics of the Chelyabinsk superbolide

Science.gov (United States)

Yanagisawa, Masahisa

2015-12-01

On Feb. 15, 2013, a meteoroid with a size of about 19 m plunged into the terrestrial atmosphere at 19 km s-1 and burst at an altitude of about 30 km over the city of Chelyabinsk, Russia. Here we present light curves for the bolide in the red, green, and blue color bands, derived from an analysis of a video that was recorded by a dashboard camera and released on the Internet. Our results demonstrate that the bolide was blue-green in color, which is inconsistent with the Planck spectrum before the meteoroid began to fragment. Fragmentation triggered a flare-up of the bolide and 90% of its radiation energy at optical wavelengths was released within a period of about 2 s after that. During the same period, the brightness ratios among the three bands became consistent with 4000 K blackbody radiation. Based on the peak luminosity, a surface area of several square kilometers would be required for a 4000 K blackbody. It is considered that the radiation source of the bolide was an elongated cloud of vapor and debris produced through severe fragmentation of the meteoroid.

Development of advanced, non-toxic, synthetic radiation shielding aggregate

Energy Technology Data Exchange (ETDEWEB)

Mudgal, Manish; Chouhan, Ramesh Kumar; Verma, Sarika; Amritphale, Sudhir Sitaram; Das, Satyabrata [CSIR-Advanced Materials and Processes Research Institute, Bhopal (India); Shrivastva, Arvind [Nuclear Power Corporation of India Ltd. (NPCIL), Mumbai (India)

2018-04-01

For the first time in the world, the capability of red mud waste has been explored for the development of advanced synthetic radiation shielding aggregate. Red mud, an aluminium industry waste consists of multi component, multi elemental characteristics. In this study, red mud from two different sources have been utilized. Chemical formulation and mineralogical designing of the red mud has been done by ceramic processing using appropriate reducing agent and additives. The chemical analysis, SEM microphotographs and XRD analysis confirms the presence of multi-component, multi shielding and multi-layered phases in both the different developed advance synthetic radiation shielding aggregate. The mechanical properties, namely aggregate impact value, aggregate crushing value and aggregate abrasion value have also been evaluated and was compared with hematite ore aggregate and found to be an excellent material useful for making advanced radiation shielding concrete for the construction of nuclear power plants and other radiation installations.

Phase 1 Trial of Neoadjuvant Radiation Therapy Before Prostatectomy for High-Risk Prostate Cancer

International Nuclear Information System (INIS)

Koontz, Bridget F.; Quaranta, Brian P.; Pura, John A.; Lee, W.R.; Vujaskovic, Zeljko; Gerber, Leah; Haake, Michael; Anscher, Mitchell S.; Robertson, Cary N.; Polascik, Thomas J.; Moul, Judd W.

2013-01-01

Purpose: To evaluate, in a phase 1 study, the safety of neoadjuvant whole-pelvis radiation therapy (RT) administered immediately before radical prostatectomy in men with high-risk prostate cancer. Methods and Materials: Twelve men enrolled and completed a phase 1 single-institution trial between 2006 and 2010. Eligibility required a previously untreated diagnosis of localized but high-risk prostate cancer. Median follow-up was 46 months (range, 14-74 months). Radiation therapy was dose-escalated in a 3 × 3 design with dose levels of 39.6, 45, 50.4, and 54 Gy. The pelvic lymph nodes were treated up to 45 Gy with any additional dose given to the prostate and seminal vesicles. Radical prostatectomy was performed 4-8 weeks after RT completion. Primary outcome measure was intraoperative and postoperative day-30 morbidity. Secondary measures included late morbidity and oncologic outcomes. Results: No intraoperative morbidity was seen. Chronic urinary grade 2+ toxicity occurred in 42%; 2 patients (17%) developed a symptomatic urethral stricture requiring dilation. Two-year actuarial biochemical recurrence-free survival was 67% (95% confidence interval 34%-86%). Patients with pT3 or positive surgical margin treated with neoadjuvant RT had a trend for improved biochemical recurrence-free survival compared with a historical cohort with similar adverse factors. Conclusions: Neoadjuvant RT is feasible with moderate urinary morbidity. However, oncologic outcomes do not seem to be substantially different from those with selective postoperative RT. If this multimodal approach is further evaluated in a phase 2 setting, 54 Gy should be used in combination with neoadjuvant androgen deprivation therapy to improve biochemical outcomes

Phase 1 Trial of Neoadjuvant Radiation Therapy Before Prostatectomy for High-Risk Prostate Cancer

Energy Technology Data Exchange (ETDEWEB)

Koontz, Bridget F., E-mail: Bridget.Koontz@duke.edu [Department of Radiation Oncology, Duke Cancer Institute, Durham, North Carolina (United States); Duke Prostate Center, Duke Cancer Institute, Durham, North Carolina (United States); Quaranta, Brian P. [21st Century Oncology, Asheville, North Carolina (United States); Pura, John A. [Division of Biostatistics, Duke Cancer Institute, Durham, North Carolina (United States); Lee, W.R.; Vujaskovic, Zeljko [Department of Radiation Oncology, Duke Cancer Institute, Durham, North Carolina (United States); Duke Prostate Center, Duke Cancer Institute, Durham, North Carolina (United States); Gerber, Leah [Duke Prostate Center, Duke Cancer Institute, Durham, North Carolina (United States); Haake, Michael [Southeast Radiation Oncology, Charlotte, North Carolina (United States); Anscher, Mitchell S. [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia (United States); Robertson, Cary N.; Polascik, Thomas J.; Moul, Judd W. [Department of Surgery, Duke Cancer Institute, Durham, North Carolina (United States); Duke Prostate Center, Duke Cancer Institute, Durham, North Carolina (United States)

2013-09-01

Purpose: To evaluate, in a phase 1 study, the safety of neoadjuvant whole-pelvis radiation therapy (RT) administered immediately before radical prostatectomy in men with high-risk prostate cancer. Methods and Materials: Twelve men enrolled and completed a phase 1 single-institution trial between 2006 and 2010. Eligibility required a previously untreated diagnosis of localized but high-risk prostate cancer. Median follow-up was 46 months (range, 14-74 months). Radiation therapy was dose-escalated in a 3 × 3 design with dose levels of 39.6, 45, 50.4, and 54 Gy. The pelvic lymph nodes were treated up to 45 Gy with any additional dose given to the prostate and seminal vesicles. Radical prostatectomy was performed 4-8 weeks after RT completion. Primary outcome measure was intraoperative and postoperative day-30 morbidity. Secondary measures included late morbidity and oncologic outcomes. Results: No intraoperative morbidity was seen. Chronic urinary grade 2+ toxicity occurred in 42%; 2 patients (17%) developed a symptomatic urethral stricture requiring dilation. Two-year actuarial biochemical recurrence-free survival was 67% (95% confidence interval 34%-86%). Patients with pT3 or positive surgical margin treated with neoadjuvant RT had a trend for improved biochemical recurrence-free survival compared with a historical cohort with similar adverse factors. Conclusions: Neoadjuvant RT is feasible with moderate urinary morbidity. However, oncologic outcomes do not seem to be substantially different from those with selective postoperative RT. If this multimodal approach is further evaluated in a phase 2 setting, 54 Gy should be used in combination with neoadjuvant androgen deprivation therapy to improve biochemical outcomes.

Gamma radiation effects on some nutritional and physico-chemical characteristics of stored beans (Phaseolus vulgaris L.)

International Nuclear Information System (INIS)

Mancini Filho, J.

1990-01-01

The radiation effects on physico-chemical and nutritional characteristics of three Brazilian varieties of beans (Phaseolus vulgaris, L.) - Catu, Rajado and Carioca -were studied. The analytical parameters were obtained by the determination of soaking and cooking times, biological value in rats, protein electrophoretic profile, reductors sugars, oligosaccharides, fiber and fatty acids content. Also, amyloglucosidase, phytohemagglutinins, α-amylase and tryptic inhibitors activities were analysed. It was observed the gamma radiation until determined doses promotes changes on those parameters subsequently reducing substantially the cooking time without modification of the biological value of the proteins. This alteration was particularly noticed in the hard-to-cook beans. (author)

Storm-time radiation belt electron dynamics: Repeatability in the outer radiation belt

Science.gov (United States)

Murphy, K. R.; Mann, I. R.; Rae, J.; Watt, C.; Boyd, A. J.; Turner, D. L.; Claudepierre, S. G.; Baker, D. N.; Spence, H. E.; Reeves, G. D.; Blake, J. B.; Fennell, J. F.

2017-12-01

During intervals of enhanced solar wind driving the outer radiation belt becomes extremely dynamic leading to geomagnetic storms. During these storms the flux of energetic electrons can vary by over 4 orders of magnitude. Despite recent advances in understanding the nature of competing storm-time electron loss and acceleration processes the dynamic behavior of the outer radiation belt remains poorly understood; the outer radiation belt can exhibit either no change, an enhancement, or depletion in radiation belt electrons. Using a new analysis of the total radiation belt electron content, calculated from the Van Allen probes phase space density (PSD), we statistically analyze the time-dependent and global response of the outer radiation belt during storms. We demonstrate that by removing adiabatic effects there is a clear and repeatable sequence of events in storm-time radiation belt electron dynamics. Namely, the relativistic (μ=1000 MeV/G) and ultra-relativistic (μ=4000 MeV/G) electron populations can be separated into two phases; an initial phase dominated by loss followed by a second phase dominated by acceleration. At lower energies, the radiation belt seed population of electrons (μ=150 MeV/G) shows no evidence of loss but rather a net enhancement during storms. Further, we investigate the dependence of electron dynamics as a function of the second adiabatic invariant, K. These results demonstrate a global coherency in the dynamics of the source, relativistic and ultra-relativistic electron populations as function of the second adiabatic invariant K. This analysis demonstrates two key aspects of storm-time radiation belt electron dynamics. First, the radiation belt responds repeatably to solar wind driving during geomagnetic storms. Second, the response of the radiation belt is energy dependent, relativistic electrons behaving differently than lower energy seed electrons. These results have important implications in radiation belt research. In particular

Resistive switching characteristics of interfacial phase-change memory at elevated temperature

Science.gov (United States)

Mitrofanov, Kirill V.; Saito, Yuta; Miyata, Noriyuki; Fons, Paul; Kolobov, Alexander V.; Tominaga, Junji

2018-04-01

Interfacial phase-change memory (iPCM) devices were fabricated using W and TiN for the bottom and top contacts, respectively, and the effect of operation temperature on the resistive switching was examined over the range between room temperature and 200 °C. It was found that the high-resistance (RESET) state in an iPCM device drops sharply at around 150 °C to a low-resistance (SET) state, which differs by ˜400 Ω from the SET state obtained by electric-field-induced switching. The iPCM device SET state resistance recovered during the cooling process and remained at nearly the same value for the RESET state. These resistance characteristics greatly differ from those of the conventional Ge-Sb-Te (GST) alloy phase-change memory device, underscoring the fundamentally different switching nature of iPCM devices. From the thermal stability measurements of iPCM devices, their optimal temperature operation was concluded to be less than 100 °C.

Synchrotron radiation losses in Engineering Test Reactors (ETRs)

International Nuclear Information System (INIS)

Uckan, N.A.

1987-11-01

In next-generation Engineering Test Reactors (ETRs), one major objective is envisioned to be a long-pulse or steady-state burn using noninductive current drive. At the high temperatures needed for efficient current drive, synchrotron radiation could represent a large power loss, especially if wall reflectivity (R) is very low. Many INTOR-class ETR designs [Fusion Engineering Reactor (FER), Next European Torus (NET), OTR, Tokamak Ignition/Burn Engineering Reactor (TIBER), etc.] call for carbon-covered surfaces for which wall reflectivity is uncertain. Global radiation losses are estimated for these devices using empirical expressions given by Trubnikov (and others). Various operating scenarios are evaluated under the assumption that the plasma performance is limited by either the density limit (typical of the ignition phase) or the beta limit (typical of the current drive phase). For a case with ≥90% wall reflectivity, synchrotron radiation is not a significant contribution to the overall energy balance (the ratio of synchrotron to alpha power is less than 10 to 20%, even at ∼ 30 keV) and thus should not adversely alter performance in these devices. In extreme cases with 0% wall reflectivity, the ratio of synchrotron radiation to alpha power may approach 30 to 60% (depending on the device and limiting operating scenario), adversely affecting the performance characteristics. 12 refs., 7 tabs

RTOG 0211: A Phase 1/2 Study of Radiation Therapy With Concurrent Gefitinib for Newly Diagnosed Glioblastoma Patients

International Nuclear Information System (INIS)

Chakravarti, Arnab; Wang, Meihua; Robins, H. Ian; Lautenschlaeger, Tim; Curran, Walter J.; Brachman, David G.; Schultz, Christopher J.; Choucair, Ali; Dolled-Filhart, Marisa; Christiansen, Jason; Gustavson, Mark; Molinaro, Annette; Mischel, Paul; Dicker, Adam P.

2013-01-01

Purpose: To determine the safety and efficacy of gefitinib, an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, in combination with radiation for newly diagnosed glioblastoma (GBM) patients. Methods and Materials: Between March 21, 2002, and May 3, 2004, Radiation Therapy Oncology Group (RTOG) 0211 enrolled 31 and 147 GBM patients in the phase 1 and 2 arms, respectively. Treatment consisted of daily oral gefinitnib started at the time of conventional cranial radiation therapy (RT) and continued post RT for 18 months or until progression. Tissue microarrays from 68 cases were analyzed for EGFR expression. Results: The maximum tolerated dose (MTD) of gefitinib was determined to be 500 mg in patients on non-enzyme-inducing anticonvulsant drugs (non-EIAEDs). All patients in the phase 2 component were treated at a gefitinib dose of 500 mg; patients receiving EIADSs could be escalated to 750 mg. The most common side effects of gefitinib in combination with radiation were dermatologic and gastrointestinal. Median survival was 11.5 months for patients treated per protocol. There was no overall survival benefit for patients treated with gefitinib + RT when compared with a historical cohort of patients treated with RT alone, matched by RTOG recursive partitioning analysis (RPA) class distribution. Younger age was significantly associated with better outcome. Per protocol stratification, EGFR expression was not found to be of prognostic value for gefitinib + RT-treated patients. Conclusions: The addition of gefitinib to RT is well tolerated. Median survival of RTOG 0211 patients treated with RT with concurrent and adjuvant gefitinib was similar to that in a historical control cohort treated with radiation alone

Extending the possibilities in phase space analysis of synchrotron radiation x-ray optics.

Science.gov (United States)

Ferrero, Claudio; Smilgies, Detlef-Matthias; Riekel, Christian; Gatta, Gilles; Daly, Peter

2008-08-01

A simple analytical approach to phase space analysis of the performance of x-ray optical setups (beamlines) combining several elements in position-angle-wavelength space is presented. The mathematical description of a large class of optical elements commonly used on synchrotron beamlines has been reviewed and extended with respect to the existing literature and is reported in a revised form. Novel features are introduced, in particular, the possibility to account for imperfections on mirror surfaces and to incorporate nanofocusing devices like refractive lenses in advanced beamline setups using the same analytical framework. Phase space analysis results of the simulation of an undulator beamline with focusing optics at the European Synchrotron Radiation Facility compare favorably with results obtained by geometric ray-tracing methods and, more importantly, with experimental measurements. This approach has been implemented into a simple and easy-to-use program toolkit for optical calculations based on the Mathematica software package.

Radiation damage of metal uranium

International Nuclear Information System (INIS)

Mihajlovic, A.

1965-01-01

This report is concerned with the role of dispersion second phase in uranium and burnup rate. The role of dispersion phases in radiation stability of metal uranium was studies by three methods: variation of electric conductivity dependent on the neutron flux and temperature of pure uranium for different states of dispersion second phase; influence of dispersion phase on the radiation creep; transmission electron microscopy of fresh and irradiated uranium

Experiment study about phase transition characteristics of CO{sub 2} in low-permeable porous media

Energy Technology Data Exchange (ETDEWEB)

Guo, P.; Wang, J.; Luo, Y. [State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu (China); Southwest Petroleum Univ., Chengdu (China); Fan, J.M. [PetroChina, Xian (China). Ultra-low Permeability Reservoir Research Inst.

2009-07-01

This paper described an experimental study conducted to characterize phase changes in carbon dioxide (CO{sub 2}) that occur during CO{sub 2} sequestration and enhanced oil recovery (EOR) processes. An ultrasonic testing method was used to determine the influence of pressure and temperature on core fluids. Phase transitions were characterized by collecting time series of ultrasonic signals in a data acquisition system and calculating the correlation dimension of the phase space. A correlation dimension analysis method was used with a fractal theory to develop correlation curves for the phase transition characteristics of CO{sub 2} in porous media. The study demonstrated that below a critical temperature, the existence of porous media can increase the phase transition point of CO{sub 2}. Above the critical temperature, the existence of porous media decreased the inflection point in the pressure-volume relationship curve for CO{sub 2}. Time difference changes were also more apparent above the critical temperature. 11 refs., 2 tabs., 11 figs.

Study of the spectral and energy characteristics of lasing in the green spectral region by lithium fluoride with radiation color centers

Energy Technology Data Exchange (ETDEWEB)

Voitovich, A.P.; Kalinov, V.S.; Mikhnov, S.A.; Ovseichuk, S.I.

1987-06-01

The spectral and energy characteristics of lasers utilizing lithium fluoride with F2 and F3(+) color centers in transverse and longitudinal pumping schemes are studied. The feasibility of obtaining stable narrow-band radiation in the 510-570 nm range using a selective resonator is demonstrated. Consideration is given to the effect of lithium-fluoride crystal processing by excimer laser radiation at a wavelength of 308 nm on the spectroscopic and lasing characteristics of the F3(+) color center. After this processing, the laser efficiency in the green spectral region increases by more than a factor of two (reaching an efficiency of 14 percent). 7 references.

Space Weather Action Plan Ionizing Radiation Benchmarks: Phase 1 update and plans for Phase 2

Science.gov (United States)

Talaat, E. R.; Kozyra, J.; Onsager, T. G.; Posner, A.; Allen, J. E., Jr.; Black, C.; Christian, E. R.; Copeland, K.; Fry, D. J.; Johnston, W. R.; Kanekal, S. G.; Mertens, C. J.; Minow, J. I.; Pierson, J.; Rutledge, R.; Semones, E.; Sibeck, D. G.; St Cyr, O. C.; Xapsos, M.

2017-12-01

Changes in the near-Earth radiation environment can affect satellite operations, astronauts in space, commercial space activities, and the radiation environment on aircraft at relevant latitudes or altitudes. Understanding the diverse effects of increased radiation is challenging, but producing ionizing radiation benchmarks will help address these effects. The following areas have been considered in addressing the near-Earth radiation environment: the Earth's trapped radiation belts, the galactic cosmic ray background, and solar energetic-particle events. The radiation benchmarks attempt to account for any change in the near-Earth radiation environment, which, under extreme cases, could present a significant risk to critical infrastructure operations or human health. The goal of these ionizing radiation benchmarks and associated confidence levels will define at least the radiation intensity as a function of time, particle type, and energy for an occurrence frequency of 1 in 100 years and an intensity level at the theoretical maximum for the event. In this paper, we present the benchmarks that address radiation levels at all applicable altitudes and latitudes in the near-Earth environment, the assumptions made and the associated uncertainties, and the next steps planned for updating the benchmarks.

A three-dimensional phase space dynamical model of the Earth's radiation belt

International Nuclear Information System (INIS)

Boscher, D. M.; Beutier, T.; Bourdarie, S.

1996-01-01

A three dimensional phase space model of the Earth's radiation belt is presented. We have taken into account the magnetic and electric radial diffusions, the pitch angle diffusions due to Coulomb interactions and interactions with the plasmaspheric hiss, and the Coulomb drag. First, a steady state of the belt is presented. Two main maxima are obtained, corresponding to the inner and outer parts of the belt. Then, we have modelled a simple injection at the external boundary. The particle transport seems like what was measured aboard satellites. A high energy particle loss is found, by comparing the model results and the measurements. It remains to be explained

Attenuation characteristics of materials used in radiation protection as radiation shielding

International Nuclear Information System (INIS)

Almeida Junior, Airton T.; Araujo, F.G.S.; Nogueira, M.S.; Santos, M.A.P.

2013-01-01

Crystal glass has been widely used as shielding material in gamma radiation sources as well as x-ray generating equipment to replace the plumbiferous glass, in order to minimize exposure to individuals. In this work, ten plates of crystal glass, with dimensions of 20cm x 20cm and range of thicknesses from 0.5 to 2.0 cm, and barite concrete were irradiated with potential constants of 60kV, 80kV, 110kV, 150kV and gamma radiation of 60 Co. The curves of attenuation and of transmission were obtained for crystal glass, barite plaster and barite concrete (mGy/mA.min) at 1 meter as a function of thickness.Crystal glass has been widely used as shielding material in gamma radiation sources as well as x-ray generating equipment to replace the plumbiferous glass, in order to minimize exposure to individuals. In this work, ten plates of crystal glass, with dimensions of 20cm x 20cm and range of thicknesses from 0.5 to 2.0 cm, and barite concrete were irradiated with potential constants of 60kV, 80kV, 110kV, 150kV and gamma radiation of 60 Co. The curves of attenuation and of transmission were obtained for crystal glass, barite plaster and barite concrete (mGy/mA.min) at 1 meter as a function of thickness. (author)

Three-dimensional, position-sensitive radiation detection

Science.gov (United States)

He, Zhong; Zhang, Feng

2010-04-06

Disclosed herein is a method of determining a characteristic of radiation detected by a radiation detector via a multiple-pixel event having a plurality of radiation interactions. The method includes determining a cathode-to-anode signal ratio for a selected interaction of the plurality of radiation interactions based on electron drift time data for the selected interaction, and determining the radiation characteristic for the multiple-pixel event based on both the cathode-to-anode signal ratio and the electron drift time data. In some embodiments, the method further includes determining a correction factor for the radiation characteristic based on an interaction depth of the plurality of radiation interactions, a lateral distance between the selected interaction and a further interaction of the plurality of radiation interactions, and the lateral positioning of the plurality of radiation interactions.

General relativistic radiative transfer code in rotating black hole space-time: ARTIST

Science.gov (United States)

Takahashi, Rohta; Umemura, Masayuki

2017-02-01

We present a general relativistic radiative transfer code, ARTIST (Authentic Radiative Transfer In Space-Time), that is a perfectly causal scheme to pursue the propagation of radiation with absorption and scattering around a Kerr black hole. The code explicitly solves the invariant radiation intensity along null geodesics in the Kerr-Schild coordinates, and therefore properly includes light bending, Doppler boosting, frame dragging, and gravitational redshifts. The notable aspect of ARTIST is that it conserves the radiative energy with high accuracy, and is not subject to the numerical diffusion, since the transfer is solved on long characteristics along null geodesics. We first solve the wavefront propagation around a Kerr black hole that was originally explored by Hanni. This demonstrates repeated wavefront collisions, light bending, and causal propagation of radiation with the speed of light. We show that the decay rate of the total energy of wavefronts near a black hole is determined solely by the black hole spin in late phases, in agreement with analytic expectations. As a result, the ARTIST turns out to correctly solve the general relativistic radiation fields until late phases as t ˜ 90 M. We also explore the effects of absorption and scattering, and apply this code for a photon wall problem and an orbiting hotspot problem. All the simulations in this study are performed in the equatorial plane around a Kerr black hole. The ARTIST is the first step to realize the general relativistic radiation hydrodynamics.

Selectivity of calixarene-bonded silica phases in HPLC: Description of special characteristics with a multiple term linear equation at different methanol concentrations.

Science.gov (United States)

Schneider, Christian; Jira, Thomas

2010-10-01

Retention and selectivity characteristics of different calixarene-, resorcinarene- and alkyl-bonded stationary phases are examined by analyzing a set of test solutes covering the main interactions (hydrophobic, steric, ionic, polar) that apply in HPLC. Therefore Dolan and Snyder's multiple term linear equation has been adapted to fit the properties of calixarene-bonded columns. The obtained parameters are used to describe retention and selectivity of the novel Caltrex(®) phases and to elucidate underlying mechanisms of retention. Here, differences of stationary phase characteristics at different methanol concentrations in the mobile phases are examined. Both selectivity and retention were found to depend on the methanol content. Differences of these dependencies were found for different stationary phases and interactions. The differences between common alkyl-bonded and novel calixarene-bonded phases increase with increasing methanol content.

Investigation of thermo-optical characteristics of the interaction processes of laser radiation with silver nanoparticles

International Nuclear Information System (INIS)

Pustovalov, V K; Astafyeva, L G

2013-01-01

Metallic nanoparticles have been actively investigated in recent years by different optical and laser methods with the purpose of their applications in optoelectronics and photonics, chemistry, laser nanobiomedicine, optical diagnostics, and other fields. A major role among metallic nanoparticles is played by nanoparticles from the noble metals (silver, gold, etc). These particles have unique plasmonic properties (resonances in the range of wavelength 400–540 nm), which can be used for the absorption, scattering and transformation of laser energy. Analysis of the thermo-optical characteristics of the interaction processes of laser radiation with silver nanoparticles is carried out, taking into account absorption, scattering and extinction of laser radiation by nanoparticles, as well as the thermo-optical and other properties of nanoparticles. Estimations are made of the influence of these nanoparticle properties on the possible results of laser radiation interaction with silver nanoparticles, including heating, heat exchange, possible melting and evaporation, and processes in the ambient media. These results can be used in laser processing of silver nanoparticles and their applications in laser nanomedicine. (paper)

Radiative Cooling: Principles, Progress, and Potentials

Science.gov (United States)

Hossain, Md. Muntasir

2016-01-01

The recent progress on radiative cooling reveals its potential for applications in highly efficient passive cooling. This approach utilizes the maximized emission of infrared thermal radiation through the atmospheric window for releasing heat and minimized absorption of incoming atmospheric radiation. These simultaneous processes can lead to a device temperature substantially below the ambient temperature. Although the application of radiative cooling for nighttime cooling was demonstrated a few decades ago, significant cooling under direct sunlight has been achieved only recently, indicating its potential as a practical passive cooler during the day. In this article, the basic principles of radiative cooling and its performance characteristics for nonradiative contributions, solar radiation, and atmospheric conditions are discussed. The recent advancements over the traditional approaches and their material and structural characteristics are outlined. The key characteristics of the thermal radiators and solar reflectors of the current state‐of‐the‐art radiative coolers are evaluated and their benchmarks are remarked for the peak cooling ability. The scopes for further improvements on radiative cooling efficiency for optimized device characteristics are also theoretically estimated. PMID:27812478

A NEW FAMILY OF MULTISTEP METHODS WITH IMPROVED PHASE-LAG CHARACTERISTICS FOR THE INTEGRATION OF ORBITAL PROBLEMS

International Nuclear Information System (INIS)

Vlachos, D. S.; Anastassi, Z. A.; Simos, T. E.

2009-01-01

In this paper, we introduce a new family of 10-step linear multistep methods for the integration of orbital problems. The new methods are constructed by adopting a new methodology which improves the phase-lag characteristics by vanishing both the phase-lag function and its first derivatives at a specific frequency. The efficiency of the new family of methods is proved via error analysis and numerical applications.

Estimates of radiation over clouds and dust aerosols: Optimized number of terms in phase function expansion

International Nuclear Information System (INIS)

Ding Shouguo; Xie Yu; Yang Ping; Weng Fuzhong; Liu Quanhua; Baum, Bryan; Hu Yongxiang

2009-01-01

The bulk-scattering properties of dust aerosols and clouds are computed for the community radiative transfer model (CRTM) that is a flagship effort of the Joint Center for Satellite Data Assimilation (JCSDA). The delta-fit method is employed to truncate the forward peaks of the scattering phase functions and to compute the Legendre expansion coefficients for re-constructing the truncated phase function. Use of more terms in the expansion gives more accurate re-construction of the phase function, but the issue remains as to how many terms are necessary for different applications. To explore this issue further, the bidirectional reflectances associated with dust aerosols, water clouds, and ice clouds are simulated with various numbers of Legendre expansion terms. To have relative numerical errors smaller than 5%, the present analyses indicate that, in the visible spectrum, 16 Legendre polynomials should be used for dust aerosols, while 32 Legendre expansion terms should be used for both water and ice clouds. In the infrared spectrum, the brightness temperatures at the top of the atmosphere are computed by using the scattering properties of dust aerosols, water clouds and ice clouds. Although small differences of brightness temperatures compared with the counterparts computed with 4, 8, 128 expansion terms are observed at large viewing angles for each layer, it is shown that 4 terms of Legendre polynomials are sufficient in the radiative transfer computation at infrared wavelengths for practical applications.

Thermoluminescence characteristics of different dimensions of Ge-doped optical fibers in radiation dosimetry

Energy Technology Data Exchange (ETDEWEB)

Begum, M.; Mizanur R, A. K. M.; Abdul R, H. A.; Yusoff, Z. [Multimedia University, Faculty of Engineering, 63100 Cyberjaya, Selangor Darul Ehsan (Malaysia); Begum, M. [Bangladesh Atomic Energy Commission, E-12/A, Agargaon, Sher-e-Blanga Nagar Dhaka-1207 (Bangladesh); Mat-Sharif, K. A. [Lingkaran Teknokrat Timur, Telekom Research and Development, 63000 Cyberjaya, Selangor Darul Ehsan (Malaysia); Amin, Y. M. [University of Malaya, Faculty of Science, Depatment of Physics, 50603 Kuala Lumpur (Malaysia); Bradley, D. A., E-mail: go2munmun@yahoo.com [University of Surrey, Department of Physics, Guildford GU2 7XH (United Kingdom)

2014-08-15

Important thermoluminescence (Tl) properties of five (5) different core sizes Ge doped optical fibers have been studied to develop new Tl material with better response. These are drawn from same preform applying different speed and tension during drawing phase. The results of the investigations are also compared with most commonly used standard TLD-100 chips (LiF:Mg,Ti) and commercial multimode Ge doped optical fiber (Yangtze Optical Fiber, China). Scanning Electron Microscope (Sem) and EDX analysis of the fibers are also performed to map Ge distribution across the deposited region. Standard Gamma radiation source in SSDL (Secondary Standard Dosimetry Lab) was used for irradiation covering dose range from 1 Gy to 10 Gy. The essential dosimetric parameters that have been studied are Tl linearity, reproducibility and fading. Prior to irradiation all samples ∼0.5 cm length are annealed at temperature of 400 grades C for 1 hour period to standardize their sensitivities and background. Standard TLD-100 chips are also annealed for 1 hour at 400 grades C and subsequently 2 hours at 100 grades C to yield the highest sensitivity. Tl responses of these fibers show linearity over a wide gamma radiation dose that is an important property for radiation dosimetry. Among all fibers used in this study, 100 μm core diameter fiber provides highest response that is 2.6 times than that of smallest core (20 μm core) optical fiber. These fiber-samples demonstrate better response than commercial multi-mode optical fiber and also provide low degree of fading about 20% over a period of fifteen days for gamma radiation. Effective atomic number (Z{sub eff}) is found in the range (13.25 to 13.69) that is higher than soft tissue (7.5) however within the range of human-bone (11.6-13.8). All the fibers can also be re-used several times as a detector after annealing. Tl properties of the Ge-doped optical fibers indicate promising applications in ionizing radiation dosimetry. (author)

Thermoluminescence characteristics of different dimensions of Ge-doped optical fibers in radiation dosimetry

International Nuclear Information System (INIS)

Begum, M.; Mizanur R, A. K. M.; Abdul R, H. A.; Yusoff, Z.; Begum, M.; Mat-Sharif, K. A.; Amin, Y. M.; Bradley, D. A.

2014-08-01

Important thermoluminescence (Tl) properties of five (5) different core sizes Ge doped optical fibers have been studied to develop new Tl material with better response. These are drawn from same preform applying different speed and tension during drawing phase. The results of the investigations are also compared with most commonly used standard TLD-100 chips (LiF:Mg,Ti) and commercial multimode Ge doped optical fiber (Yangtze Optical Fiber, China). Scanning Electron Microscope (Sem) and EDX analysis of the fibers are also performed to map Ge distribution across the deposited region. Standard Gamma radiation source in SSDL (Secondary Standard Dosimetry Lab) was used for irradiation covering dose range from 1 Gy to 10 Gy. The essential dosimetric parameters that have been studied are Tl linearity, reproducibility and fading. Prior to irradiation all samples ∼0.5 cm length are annealed at temperature of 400 grades C for 1 hour period to standardize their sensitivities and background. Standard TLD-100 chips are also annealed for 1 hour at 400 grades C and subsequently 2 hours at 100 grades C to yield the highest sensitivity. Tl responses of these fibers show linearity over a wide gamma radiation dose that is an important property for radiation dosimetry. Among all fibers used in this study, 100 μm core diameter fiber provides highest response that is 2.6 times than that of smallest core (20 μm core) optical fiber. These fiber-samples demonstrate better response than commercial multi-mode optical fiber and also provide low degree of fading about 20% over a period of fifteen days for gamma radiation. Effective atomic number (Z eff ) is found in the range (13.25 to 13.69) that is higher than soft tissue (7.5) however within the range of human-bone (11.6-13.8). All the fibers can also be re-used several times as a detector after annealing. Tl properties of the Ge-doped optical fibers indicate promising applications in ionizing radiation dosimetry. (author)

Flow characteristics of centrifugal gas-liquid separator. Investigation with air-water two-phase flow experiment

International Nuclear Information System (INIS)

Yoneda, Kimitoshi; Inada, Fumio

2004-01-01

Air-water two-phase flow experiment was conducted to examine the basic flow characteristics of a centrifugal gas-liquid separator. Vertical transparent test section, which is 4 m in height, was used to imitate the scale of a BWR separator. Flow rate conditions of gas and liquid were fixed at 0.1 m 3 /s and 0.033 m 3 /s, respectively. Radial distributions of two-phase flow characteristics, such as void fraction, gas velocity and bubble chord length, were measured by traversing dual optical void probes in the test section, horizontally. The flow in the standpipe reached to quasi-developed state within the height-to-diameter aspect ratio H/D=10, which in turn can mean the maximum value for an ideal height design of a standpipe. The liquid film in the barrel showed a maximum thickness at 0.5 to 1 m in height from the swirler exit, which was a common result for three different standpipe length conditions, qualitatively and quantitatively. The empirical database obtained in this study would contribute practically to the validation of numerical analyses for an actual separator in a plant, and would also be academically useful for further investigations of two-phase flow in large-diameter pipes. (author)

Radiation therapy for ocular choroidal neovascularization (phase I/II study)

International Nuclear Information System (INIS)

Sasai, Keisuke; Murata, Rumi; Mandai, Michiko; Takahashi, Masayo; Hiraoka, Masahiro

1996-01-01

Purpose/Objective: Choroidal neovascularization (CNV) is a major cause of severe loss of visual acuity in some ocular diseases such as age-related macular degeneration (ARMD) and angio-streaks. Laser photocoagulation has been used to treat patients with subfoveal neovascular lesions with well demarcated boundaries. However, the treatment method is usually associated with a large decrease in visual acuity. Therefore, indications for this treatment are very limited. Recently, some investigators reported the effect of low dose irradiation on the subretinal neovascular membranes in CNV. We conducted a phase I/II study to determine the toxicity and efficacy of external photon beam radiotherapy in patients with CNV. Materials and Methods: Between April 1994 and July 1995, 36 patients with choroidal neovascularization (34 with ARMD; 2 with angiostreaks) were treated with radiation therapy. Eligibility criteria for this study were as follows: the eyes had subretinal neovascular membranes in the avascular area of the fovea; the neovascular membranes had grown in size in the last 6 months; the best pretreatment corrected visual acuity was worse than (20(25)); there were no large subretinal hemorrhages causing decrease in visual acuity; patients were 50 years or older and had not received laser photocoagulation nor other treatment for this condition. Written informed consent was obtained from all patients. The patients underwent fluorescein angiographic evaluation and documentation of their neovascular disease prior to irradiation. Fluorescein angiography, measurement of the best corrected visual acuity, ophthalmoscopic and biomicroscopic examinations were performed at 1, 3, 6, and 12 months after treatment. Treatment planning was performed using a CT simulator which enables real-time treatment planning from multiple CT slices. The clinical target volume included the macula and optic disc, which received a dose of 10 Gy/5 fractions/1 week (first 18 eyes) or 20 Gy/10 fractions

Effect of radiation on microbiologic characteristics of M. tuberculosis

International Nuclear Information System (INIS)

Zack, M.B.; Stottmeier, K.; Berg, G.; Kazemi, H.

1974-01-01

The effect of irradiation on mutation (expressing itself as drug resistance) and on viability of Mycobacterium tuberculosis was studied in vitro. Forty-two identical cultures of H37-Rv (M. tuberculosis) were exposed to different levels of cobalt radiation (10, 100, 1,000, 2,500, 5,000, 10,000, and 20,000 rads) with six samples used for each of the seven radiation levels. Equivalent samples exposed to zero rads and samples handled and stored identically formed the controls. Coded cultures were read in a double-blind fashion to determine the number of surviving organisms and sensitivities to nine different antituberculosis drugs. Organism viability began to decrease at radiation levels of 1,000 rads and decreased linearly with higher levels of radiation. Three of the 42 radiated cultures developed drug-resistant organisms (one to INH, one to PAS, a third to SM). This drug resistance occurred at levels of clinical significance (greater than 1 percent control) as well as in amounts exceeding probability values for chance resistance mutation. High radiation levels such as occur in radiotherapeutic doses decrease the viability of M. tuberculosis. Radiation may also induce genetic mutation expressed as primary drug resistance. (U.S.)

A Phase I Study of the Combination of Sorafenib With Temozolomide and Radiation Therapy for the Treatment of Primary and Recurrent High-Grade Gliomas

International Nuclear Information System (INIS)

Den, Robert B.; Kamrava, Mitchell; Sheng, Zhi; Werner-Wasik, Maria; Dougherty, Erin; Marinucchi, Michelle; Lawrence, Yaacov R.; Hegarty, Sarah; Hyslop, Terry; Andrews, David W.; Glass, Jon; Friedman, David P.; Green, Michael R.; Camphausen, Kevin; Dicker, Adam P.

2013-01-01

Purpose: Despite recent advances in the management of high-grade and recurrent gliomas, survival remains poor. Antiangiogenic therapy has been shown to be efficacious in the treatment of high-grade gliomas both in preclinical models and in clinical trials. We sought to determine the safety and maximum tolerated dose of sorafenib when combined with both radiation and temozolomide in the primary setting or radiation alone in the recurrent setting. Methods and Materials: This was a preclinical study and an open-label phase I dose escalation trial. Multiple glioma cell lines were analyzed for viability after treatment with radiation, temozolomide, or sorafenib or combinations of them. For patients with primary disease, sorafenib was given concurrently with temozolomide (75 mg/m 2 ) and 60 Gy radiation, for 30 days after completion of radiation. For patients with recurrent disease, sorafenib was combined with a hypofractionated course of radiation (35 Gy in 10 fractions). Results: Cell viability was significantly reduced with the combination of radiation, temozolomide, and sorafenib or radiation and sorafenib. Eighteen patients (11 in the primary cohort, 7 in the recurrent cohort) were enrolled onto this trial approved by the institutional review board. All patients completed the planned course of radiation therapy. The most common toxicities were hematologic, fatigue, and rash. There were 18 grade 3 or higher toxicities. The median overall survival was 18 months for the entire population. Conclusions: Sorafenib can be safely combined with radiation and temozolomide in patients with high-grade glioma and with radiation alone in patients with recurrent glioma. The recommended phase II dose of sorafenib is 200 mg twice daily when combined with temozolomide and radiation and 400 mg with radiation alone. To our knowledge, this is the first publication of concurrent sorafenib with radiation monotherapy or combined with radiation and temozolomide.

Peracute radiation pneumonitis

Energy Technology Data Exchange (ETDEWEB)

Dvorak, E

1982-01-01

Progressive tendencies in curative radiation therapy approach in the treatment of bronchogenic carcinoma will generally prolong a treatment course and modify the manifestation of radiation pneumonitis. There will probably be a tendency for an earlier onset of its acute phase, especially if the irradiated lung was atelectatic with or without post-obstructive pneumonia or if there were changes of chronic pulmonary disease. A peracute of radiation pneumonitis after a tumor dose of 6400 cGy in 29 fractions over 48 days starting within one week after the completion of irradiation is documented and discussed. Literature dealing with clinical, pathological, pathophysiological, and radiographic manifestations of radiation pneumonitis is shortly reviewed. Usage of corticosteroid therapy in the acute phase of radiation pneumonitis is described and controversial reports on this subject are mentioned. Beneficial effect of dexamethasone in the presented case is demonstrated on sequential radiograms.

Apparatus for minimizing radiation exposure and improving resolution in radiation imaging devices

International Nuclear Information System (INIS)

Ashe, J.B.; Williams, G.H.; Sypal, K.L.

1978-01-01

A collimator is disclosed for minimizing radiation exposure and improving resolution in radiation imaging devices. The collimator provides a penetrating beam of radiation from a source thereof, which beam is substantially non-diverging in at least one direction. In the preferred embodiment, the collimator comprises an elongated sandwich assembly of a plurality of layers of material exhibiting relatively high radiation attenuation characteristics, which attenuating layers are spaced apart and separated from one another by interleaved layers of material exhibiting relatively low radiation attenuation characteristics. The sandwich assembly is adapted for lengthwise disposition and orientation between a radiation source and a target or receiver such that the attenuating layers are parallel to the desired direction of the beam with the interleaved spacing layers providing direct paths for the radiation

Precautions against radiations

International Nuclear Information System (INIS)

Osborn, S.B.

1986-01-01

In this chapter the characteristics of ionizing and non-ionizing radiations likely to cause hazards in a chemical laboratory are considered. Quantities and units of radiation are described. The general principles of radiation protection, precautions against radiation hazards, ICRP standards and recommendations and the legislation relating to the control of radiation hazards in the UK are discussed. (U.K.)

Modern new nuclear fuel characteristics and radiation protection aspects.

Science.gov (United States)

Terry, Ian R

2005-01-01

The glut of fissile material from reprocessing plants and from the conclusion of the cold war has provided the opportunity to design new fuel types to beneficially dispose of such stocks by generating useful power. Thus, in addition to the normal reactor core complement of enriched uranium fuel assemblies, two other types are available on the world market. These are the ERU (enriched recycled uranium) and the MOX (mixed oxide) fuel assemblies. Framatome ANP produces ERU fuel assemblies by taking feed material from reprocessing facilities and blending this with highly enriched uranium from other sources. MOX fuel assemblies contain plutonium isotopes, thus exploiting the higher neutron yield of the plutonium fission process. This paper describes and evaluates the gamma, spontaneous and alpha reaction neutron source terms of these non-irradiated fuel assembly types by defining their nuclear characteristics. The dose rates which arise from these terms are provided along with an overview of radiation protection aspects for consideration in transporting and delivering such fuel assemblies to power generating utilities.

The chemistry of two-component fluoride crystalline optical media for heavy, fast, radiation hard scintillators

International Nuclear Information System (INIS)

Sobolev, B.P.; Krivandina, E.A.; Fedorov, P.P.; Vasilchenko, V.G.

1994-01-01

Prospects for preparation of two-component dense optical materials for scintillators are shown, using data on phase diagrams of about 300 MF m - RF n (m, n ≤ 4) type systems, formed by metal fluorides. Primary characteristics (decay time and light output of luminescence, radiation hardness, etc.) of some multicomponent crystals are reported

Review on the characteristics of radiation detectors for dosimetry and imaging

International Nuclear Information System (INIS)

Seco, Joao; Clasie, Ben; Partridge, Mike

2014-01-01

The enormous advances in the understanding of human anatomy, physiology and pathology in recent decades have led to ever-improving methods of disease prevention, diagnosis and treatment. Many of these achievements have been enabled, at least in part, by advances in ionizing radiation detectors. Radiology has been transformed by the implementation of multi-slice CT and digital x-ray imaging systems, with silver halide films now largely obsolete for many applications. Nuclear medicine has benefited from more sensitive, faster and higher-resolution detectors delivering ever-higher SPECT and PET image quality. PET/MR systems have been enabled by the development of gamma ray detectors that can operate in high magnetic fields. These huge advances in imaging have enabled equally impressive steps forward in radiotherapy delivery accuracy, with 4DCT, PET and MRI routinely used in treatment planning and online image guidance provided by cone-beam CT. The challenge of ensuring safe, accurate and precise delivery of highly complex radiation fields has also both driven and benefited from advances in radiation detectors. Detector systems have been developed for the measurement of electron, intensity-modulated and modulated arc x-ray, proton and ion beams, and around brachytherapy sources based on a very wide range of technologies. The types of measurement performed are equally wide, encompassing commissioning and quality assurance, reference dosimetry, in vivo dosimetry and personal and environmental monitoring. In this article, we briefly introduce the general physical characteristics and properties that are commonly used to describe the behaviour and performance of both discrete and imaging detectors. The physical principles of operation of calorimeters; ionization and charge detectors; semiconductor, luminescent, scintillating and chemical detectors; and radiochromic and radiographic films are then reviewed and their principle applications discussed. Finally, a general

Characteristics of natural background external radiation and effective dose equivalent

International Nuclear Information System (INIS)

Fujimoto, Kenzo

1989-01-01

The two sources of natural radiation - cosmic rays and primordial radionuclides - are described. The factors affecting radiation doses received from natural radiation and the calculation of effective dose equivalent due to natural radiation are discussed. 10 figs., 3 tabs

A phase I/II study of neoadjuvant chemotherapy followed by radiation with boost chemotherapy for advanced T-stage nasopharyngeal carcinoma

International Nuclear Information System (INIS)

Johnson, Faye M.; Garden, Adam S.; Palmer, J. Lynn; Shin, Dong M.; Morrison, William; Papadimitrakopoulou, Vassiliki; Khuri, Fadlo; Clayman, Gary; Goepfert, Helmuth; Ang, K. Kian; Hong, Waun K.; Glisson, Bonnie S.

2005-01-01

Purpose: Local recurrence is the most common site of failure for locally advanced nasopharyngeal carcinoma (NPC) treated with neoadjuvant cisplatin/5-fluorouracil (PF) and definitive radiation at our center. Based on this, we studied the addition of chemotherapy during the boost phase of radiation after neoadjuvant PF for advanced T-stage (T3-T4) NPC. This strategy was based on theoretical radiosensitization with chemotherapy during accelerated repopulation of the tumor with relatively radioresistant clonogens. Methods and Materials: Three cycles of neoadjuvant PF was followed by conventionally fractionated radiation with additional PF during the boost portion of the radiation course. An initial Phase I study was done to establish the maximum tolerated dose of concurrent PF. Results: Forty-four patients were enrolled. Six patients in Phase I defined the MTD for concurrent PF as: cisplatin 10 mg/m 2 /day and PF 320 mg/m 2 /day, on Days 1-5 during Weeks 6 and 7 of radiation therapy based on dose-limiting toxicities of mucositis, neutropenia, and thrombocytopenia. Forty-one patients were treated with concurrent therapy per protocol: complete, partial, and minor responses were seen in 23, 16, and 2 patients, respectively. Progression-free and overall survival rates at 5 years were 55% (95% CI, 41-75%) and 66% (95% CI, 52-85%), respectively. Seven of 11 tumor-related deaths were due to local recurrence. Nine of 10 patients with local recurrence had T4-stage disease at presentation. Local control of T4 disease was achieved in 74% of patients overall, and in 25% (1/4) with World Health Organization (WHO) type 1, 76% (16/21) with WHO type 2, and 90% (9/10) with WHO type 3 histology. Common toxicities included mucositis, dermatitis, fatigue, vomiting, and weight loss. Conclusions: This regimen was feasible and associated with promising overall survival. Local recurrence remains the major reason for treatment failure in advanced T-stage NPC, especially WHO types 1 and 2

Characteristics of X ray calibration fields for performance test of radiation measuring instruments

International Nuclear Information System (INIS)

Shimizu, Shigeru; Takahashi, Fumiaki; Sawahata, Tadahiro; Tohnami, Kohichi; Kikuchi, Hiroshi; Murayama, Takashi

1999-02-01

Performance test and calibration of the radiation measuring instruments for low energy photons are made using the X ray calibration fields which are monochromatically characterized by filtration of continuous X ray spectrum. The X ray calibration field needs to be characterized by some quality conditions such as quality index and homogeneity coefficient. The present report describes quality conditions, spectrum and some characteristics of X ray irradiation fields in the Facility of Radiation Standard of the Japan Atomic Energy Research Institute (FRS-JAERI). Fifty nine X ray qualities with the quality index of 0.6, 0.7, 0.8 and 0.9 were set for the tube voltages between 10 kV and 350 kV. Estimation of X ray spectrum measured with a Ge detector was made in terms of exposure, ambient dose equivalent and fluence for all the obtained qualities. Practical irradiation field was determined as the dose distribution uniformity is within ±3%. The obtained results improve the quality of X ray calibration fields and calibration accuracy. (author)

Environmental gamma-ray dose measurements with thermoluminescence dosemeters (TLD) and environmental radiation characteristics

International Nuclear Information System (INIS)

Kanematsu, Seiko

1999-01-01

It is important to evaluate environmental gamma-ray exposure both at work and home in order to assess people's collective dosages. Environmental gamma radiation was measured for air-absorbed dose with a thermoluminescence dosemeter at various points in the workplace and Ningyotoge, and workplace radiation characteristics were analyzed. From the results, the public dose due to gamma rays generated artificially was assessed to be sufficiently lower than the annual limit. For indoor environments of the workplace, the maximum dosage rate among measured values was 97 nGy/h and the minimum value was 70 nGy/h, the average over one year was 83 nGy/h. The average annual outdoor dosage for a year was 82 nGy/ h. In Ningyotoge, the maximum was 103 nGy/h, minimum 60 nGy/h, and average 88 nGy/h. These values depend on the nature of the soil and weather factors, showing higher values in the summer than in the winter in the workplace. There was no significant difference in the dosage rate in houses and the workplace. (author)

Foundations of ionizing radiation dosimetry

International Nuclear Information System (INIS)

Denisenko, O.N.; Pereslegin, I.A.

1985-01-01

Foundations of dosimetry in application to radiotherapy are presented. General characteristics of ionizing radiations and main characteristics of ionizing radiation sources, mostly used in radiotherapy, are given. Values and units for measuring ionizing radiation (activity of a radioactive substance, absorbed dose, exposure dose, integral dose and dose equivalent are considered. Different methods and instruments for ionizing radiation dosimetry are discussed. The attention is paid to the foundations of clinical dosimetry (representation of anatomo-topographic information, choice of radiation conditions, realization of radiation methods, corrections for a configuration and inhomogeneity of a patient's body, account of biological factors of radiation effects, instruments of dose field formation, control of irradiation procedure chosen)

Evolution of phase microstructure during irradiation

International Nuclear Information System (INIS)

Wiedersich, H.

1985-11-01

The phase microstructure of alloys is frequently severely altered during irradiation. Sluggish precipitation reactions including precipitation coarsening are accelerated by irradiation-enhanced diffusion. Radiation-induced segregation redistributes existing precipitate phases within the microstructure, induces precipitation of nonequilibrium phases and affects the composition of phases in multicomponent alloys. The displacement process causes disordering of ordered alloys and frequently amorphization, especially in intermetallic compounds, at low temperature. Although a good qualitative understanding of the basic process involved, i.e., displacement mixing, radiation-enhanced diffusion and radiation-induced segregation exists, methods for detailed quantitative modeling of the evolution of the microstructure of alloys remain to be developed

A national environmental/energy workforce assessment. Post-secondary education profile: radiation. Final report on phase 2

International Nuclear Information System (INIS)

1978-12-01

This study is one of 16 volumes aggregating data on representative environmental education offerings in the United States at post-secondary education institutions and in the private sector of the economy. Structured around on-site interviews, the study describes the institutions' education programs--their program structure, representative course offerings, faculty structure, and program requirements. In addition, the study provides information on the employment history of graduates. Designed as Phase II of a three-phase program, the study presents the information on schools with emphasis on radiation. The study is an overview. It doesn't include all environmental programs in the United States, and it makes no attempt to evaluate the program offerings

Radiation therapy for ocular choroidal neovascularization (phase I/II study): preliminary report

International Nuclear Information System (INIS)

Sasai, Keisuke; Murata, Rumi; Mandai, Michiko; Takahashi, Masayo; Ogura, Yuichiro; Ngata, Yasushi; Nishimura, Yasumasa; Hiraoka, Masahiro

1997-01-01

Purpose/Objective: Choroidal neovascularization (CNV) is a major cause of severe loss of visual acuity in some ocular diseases such as age-related macular degeneration (ARMD) and angioid streaks. Laser photocoagulation has been used to treat patients with subfoveal neovascular lesions with well-demarcated boundaries. However, the treatment method is usually associated with a large decrease in visual acuity. Therefore, indications for this treatment are very limited. Recently, some investigators reported the effect of low dose irradiation on the sub retinal neovascular membranes in CNV. We conducted a Phase I/II study to determine the toxicity and efficacy of external photon beam radiotherapy in patients with CNV. Methods and Materials: Between April, 1994 and July, 1995, 36 patients with choroidal neovascularization (34 with ARMD and 2 with angioid streaks) were treated with radiation therapy. Treatment planning was performed using a CT simulator that enables real-time treatment planning from multiple CT slices. The clinical target volume that included the macula and optic disc received a dose of 10 Gy/5 fractions/1 week (first 18 eyes) or 20 Gy/10 fractions/2 weeks (last 18 eyes). All eyes were irradiated with a single lateral 6 MV photon beam, angled 10 degrees posteriorly to exclude the ipsilateral lens and the contralateral eye from the radiation field. The ipsilateral lens was irradiated with less than 10% of the total reference dose. The field size averaged 3.0 x 2.5 cm. Records of the 17 eyes with CNV referred to our hospital in 1993, which satisfied the eligibility criteria for this study, were retrospectively analyzed for comparison. Results: There was no significant acute morbidity. All patients were followed regularly by both ophthalmologists and radiation oncologists. Cataract formation after 1 year of the treatment was observed in one patient who had received a dose of 20 Gy. One patient who had received 20 Gy complained of transient dry-eye sensation

Compact Raman Lidar Measurement of Liquid and Vapor Phase Water Under the Influence of Ionizing Radiation

Directory of Open Access Journals (Sweden)

Shiina Tatsuo

2016-01-01

Full Text Available A compact Raman lidar has been developed for studying phase changes of water in the atmosphere under the influence of ionization radiation. The Raman lidar is operated at the wavelength of 349 nm and backscattered Raman signals of liquid and vapor phase water are detected at 396 and 400 nm, respectively. Alpha particles emitted from 241Am of 9 MBq ionize air molecules in a scattering chamber, and the resulting ions lead to the formation of liquid water droplets. From the analysis of Raman signal intensities, it has been found that the increase in the liquid water Raman channel is approximately 3 times as much as the decrease in the vapor phase water Raman channel, which is consistent with the theoretical prediction based on the Raman cross-sections. In addition, the radius of the water droplet is estimated to be 0.2 μm.

Characteristics of the SFCL by turn-ratio of three-phase transformer

Energy Technology Data Exchange (ETDEWEB)

Jeong, I. S.; Choi, H. S.; Jung, B. I. [Chosun University, GwangJu (Korea, Republic of)

2013-12-15

According to the increase of electric consumption nowadays, power system becomes complicated. Due to this, the size of single line-to-ground fault from power system also increases to have many problems. In order to resolve these problems effectively, an Superconducting Fault Current Limiter(SFCL) was proposed and continuous study has been done. In this paper, an SFCL was combined to the neutral line of a transformer. An superconductivity has the characteristics of zero resistance below critical temperature, because of this, SFCL has nearly zero resistance, so we connecting SFCL to neutral line will not only have any loss in the normal operation but also have the less burden of electric power because of only limiting the initial fault current. We analyzed the characteristics of current, voltage according to the changes of turn ratio of 3 phase system in case of combinations of an SFCL to the neutral line. It was confirmed that the limiting rate of initial fault current by the increase of turn ratio was reduced.

Nanocomposite for Radiation Shielding, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — NASA's Advanced Extravehicular Activity (EVA) program requires the need for materials that can protect astronauts and spacecrafts from ionizing radiations such as...

Study of core characteristics on fuel and coolant type. Results of F/S phase-I

International Nuclear Information System (INIS)

Ikegami, Tetsuo; Hayashi, Hideyuki; Sasaki, Makoto; Mizuno, Tomoyasu; Yamadate, Megumi; Takaki, Naoyuki; Kurosawa, Norifumi; Sakashita, Yoshiaki; Naganuma, Masayuki

2001-03-01

The phase-I of the Feasibility Study of Commercialized Fast Reactor Cycle Systems (F/S) were started from July, 1999 and terminated at the end of FY2000 in order to executed examination about technology alternatives of various commercialized fast reactor (FR) recycle concepts, in response to the JNC middle long term enterprise plan. In the phase-I of this F/S, a number of conceptual candidates have been selected from the following 5 viewpoints: a) ensuring safety, b) economic competitiveness to future LWRs, c) efficient utilization of resources, d) reduction of environmental burden, e) enhancement of nuclear non-proliferation. As for this study from the above viewpoints, core characteristics of many kinds of reactors have been investigated, analyzed and examined a core / a fuel characteristic in the combinations of fuel and coolant types and power output scales. Based on these results, R and D plans of the phase-II to be performed have been proposed, and a database to select candidate reactor concepts has been prepared. The conclusions have been obtained in the phase-I are as follows: (1) Evaluation of a fuel form in every each coolant was compared. A promising fuel form was extracted as follows: an oxide and a metal fuel for sodium coolant cores, a metal and a nitride fuel for heavy metal coolant cores, an oxide and a nitride fuel for carbon dioxide coolant cores and a nitride fuel for He gas coolant cores. (2) As the general idea that performance of a core nucleus can be compatible with re-criticality evasion in sodium coolant large-sized oxide fuel cores, a axial blanket particle elimination radial heterogeneous core is one influential candidate. (3) In case of Pb-Bi coolant nature circulation medium size core with an oxide fuel, it is difficult to simultaneously achieve higher discharged burn-up and higher breeding ratio according to the viewpoints of the phase-I. (4) Core characteristics of a carbon dioxide coolant core shows to be almost equivalent to that of

CHARACTERISTICS OF A 4-PHASE VALVE RELUCTANCE MOTOR WHEN POWERED BY UNCAPACITOR SWITCHBOARD

Directory of Open Access Journals (Sweden)

V.B. Finkelshtein

2016-06-01

Full Text Available Purpose. Nowadays more and more in a variety of machines and mechanisms applied switched reluctance motor. When designing these engines solve the problem selection switch. While the switch scheme comprises symmetrical bridge and eight transistors, eight diodes; Miller switch comprises six transistors and six diodes; in company Graseby Controls Ltd switch circuit but four transistors and four diodes includes two capacitors. The aim is to develop a mathematical model, calculation program, a numerical analysis of the characteristics and parameters of the WFD and the characteristics of their work. Methodology. It is assumed that the resistance in the open state transistors and diodes for direct current is zero and the resistance of the transistors in the closed state, and diode reverse voltage is infinity. When feeding a single-phase motor and power at the same time two adjacent phases determined by the flow through the tooth. Results. The motor powered by a switch on the circuit symmetrical bridge power, which provides a maximum permissible winding temperature is 1.665 kW. But at the same time the surge up to 38.8%, resulting in high levels of noise and vibration. Through the installation of switching angles, ensuring reduction of torque ripple and reduce engine power to a level below which there is a decrease in the value of torque ripple, received power of 1,066 kW and a torque ripple value of 21.18 %. For engines with improved vibration acoustic characteristics necessary to use a switch of four transistors and four diodes. Practical value. For motors with improved vibration acoustic characteristics appropriate to apply uncapacitor switch on four transistors and four diodes, which allows you to receive half the value of torque ripple than the lowest value of the motor torque ripple, eating from a switch on the circuit asymmetric bridge. The cost of reluctance motor with uncapacitor switch on the circuit with four transistors and four diodes is

Thermotropic Phase Transition of Benzodithiophene Copolymer Thin Films and Its Impact on Electrical and Photovoltaic Characteristics

KAUST Repository

Ko, Sangwon

2015-02-24

© 2015 American Chemical Society. We observed a thermotropic phase transition in poly[3,4-dihexyl thiophene-2,2′:5,6′-benzo[1,2-b:4,5-b′]dithiophene] (PDHBDT) thin films accompanied by a transition from a random orientation to an ordered lamellar phase via a nearly hexagonal lattice upon annealing. We demonstrate the effect of temperature-dependent molecular packing on charge carrier mobility (μ) in organic field-effect transistors (OFETs) and photovoltaic characteristics, such as exciton diffusion length (LD) and power conversion efficiency (PCE), in organic solar cells (OSCs) using PDHBDT. The μ was continuously improved with increasing annealing temperature and PDHBDT films annealed at 270 °C resulted in a maximum μ up to 0.46 cm2/(V s) (μavg = 0.22 cm2/(V s)), which is attributed to the well-ordered lamellar structure with a closer - stacking distance of 3.5 Å as shown by grazing incidence-angle X-ray diffraction (GIXD). On the other hand, PDHBDT films with a random molecular orientation are more effective in photovoltaic devices than films with an ordered hexagonal or lamellar phase based on current-voltage characteristics of PDHBDT/C60 bilayer solar cells. This observation corresponds to an enhanced dark current density (JD) and a decreased LD upon annealing. This study provides insight into the dependence of charge transport and photovoltaic characteristics on molecular packing in polymer semiconductors, which is crucial for the management of charge and energy transport in a range of organic optoelectronic devices.

Restoring in-phase emissions from non-planar radiating elements using a transformation optics based lens

International Nuclear Information System (INIS)

Yi, Jianjia; Burokur, Shah Nawaz; Lustrac, André de; Piau, Gérard-Pascal

2015-01-01

The broadband directive in-phase emission from an array of sources conformed cylindrically is numerically and experimentally reported. Such manipulation is achieved through the use of a lens designed by transformation optics concept. The all-dielectric lens prototype is realized through three-dimensional (3D) polyjet printing and presents a graded refractive index. A microstrip antenna array fabricated using standard lithography techniques and conformed on a cylindrical surface is used as TE-polarized wave launcher for the lens. To experimentally demonstrate the broadband focusing properties and in-phase directive emissions, both the far-field radiation patterns and the near-field distributions have been measured. Experimental measurements agreeing qualitatively with numerical simulations validate the proposed lens and open the way to inexpensive all-dielectric microwave lenses for beam forming and collimation

Restoring in-phase emissions from non-planar radiating elements using a transformation optics based lens

Energy Technology Data Exchange (ETDEWEB)

Yi, Jianjia [IEF, CNRS, UMR 8622, Université Paris-Sud, 91405 Orsay Cedex (France); Burokur, Shah Nawaz, E-mail: shah-nawaz.burokur@u-psud.fr; Lustrac, André de [IEF, CNRS, UMR 8622, Université Paris-Sud, 91405 Orsay Cedex (France); Université Paris-Ouest, 92410 Ville d' Avray (France); Piau, Gérard-Pascal [AIRBUS Group Innovations, 92150 Suresnes (France)

2015-07-13

The broadband directive in-phase emission from an array of sources conformed cylindrically is numerically and experimentally reported. Such manipulation is achieved through the use of a lens designed by transformation optics concept. The all-dielectric lens prototype is realized through three-dimensional (3D) polyjet printing and presents a graded refractive index. A microstrip antenna array fabricated using standard lithography techniques and conformed on a cylindrical surface is used as TE-polarized wave launcher for the lens. To experimentally demonstrate the broadband focusing properties and in-phase directive emissions, both the far-field radiation patterns and the near-field distributions have been measured. Experimental measurements agreeing qualitatively with numerical simulations validate the proposed lens and open the way to inexpensive all-dielectric microwave lenses for beam forming and collimation.

High Efficency Lightweight Radiators, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — XC Associates proposes to build on prior work to develop and characterize a very high efficiency, lightweight radiator constructed from high thermal conductivity...

Clinical neurological characteristics of ischemic stroke subtypes in acute phase

Directory of Open Access Journals (Sweden)

S. I. Shkrobot

2018-02-01

Full Text Available Objectives. The aim of the present study was to clarify clinical neurological characteristics and different ischemic stroke subtypes unfavorable course predictors in acute phase. Material and Methods. 482 patients with different ischemic stroke subtypes were observed. Among them there were 125 (25.9 % with cardioembolic infarct (CEI, 119 (24.7 % with large artery atherosclerosis (LAAS infarct, 122 (25.3 % with lacunar stroke (LAC, 116 (24.1 % with stroke of undetermined etiology (UDE. The comparative analysis of clinical picture was performed. The predictors of unfavorable course of acute phase were established. Results. We have found out that severe neurological deficit, high mortality and the worst functional outcome during the first 14 days were observed in patients with CEI and LAAS. The highest frequency of early neurological deterioration (END was detected at LAC (in 22.7 % of patients. There was a relationship between END and presence of transient ischemic attack (TIA in past medical history, the level of systolic blood pressure (SBP at the beginning of the disease and the degree of carotid arteries stenosis on the side of lesion. The patients with LAC had mild neurological deficit and better prognosis compared with other ischemic stroke subtypes. Among the clinical factors that have impact on the CEI, LAAS and UDE acute phase course were: the size of lesion, the level of consciousness on the 1st day, the baseline SBP, patient’s age. At LAAS, the presence of transient ischemic attack (TIA in past medical history and low SBP in the onset of the disease (less than140 mm Hg has an additional prognostic value for an unfavorable functional outcome. The severity of LAC in acute period depended on its localization and size. Localization of LAC in the internal capsule, thalamus and pons were characterized by the highest severity. Conclusions. Clinical neurological features of ischemic stroke depend on its subtype and have some prognostic value

Development of methods for measuring materials nuclear characteristics, Phases, I, II, II and IV

International Nuclear Information System (INIS)

Maglic, R.

1963-04-01

This report contains the following phases of the project 'measurement of nuclear characteristics of reactor materials': nuclear performances of the neutron chopper; method for measuring total effective cross sections by transmission method on the chopper; review of methods for measuring activation cross sections; measurement of neutron spectra of the RA reactor and measurement of total effective cross section of gold by using the chopper

Wireless radiation sensor

Science.gov (United States)

Lamberti, Vincent E.; Howell, Jr, Layton N.; Mee, David K.; Kress, Reid L.

2016-08-09

Disclosed is a sensor for detecting radiation. The sensor includes a ferromagnetic metal and a radiation sensitive material coupled to the ferromagnetic metal. The radiation sensitive material is operable to change a tensile stress of the ferromagnetic metal upon exposure to radiation. The radiation is detected based on changes in the magnetic switching characteristics of the ferromagnetic metal caused by the changes in the tensile stress.

Multifunctional BHL Radiation Shield, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Advances in radiation shielding technology remain an important challenge for NASA in order to protect their astronauts, particularly as NASA grows closer to manned...

Clinical observation of radiation urinary bladder disease

International Nuclear Information System (INIS)

Jin Yuke; Liu Libo; Zhang Haiying; Liang Shuo; Chen Dawei; Wu Zhenfeng; Dong Lihua; Lu Xuejun

2004-01-01

Objective: Clinical characteristic, diagnosis and treatment of radiation urinary bladder disease induced by radiation therapy for cancers in the pelvis were inquired into for providing diagnostic basis. Methods: Statistical analysis for the clinical cases was carried out. Results: The incidence of radiation bladder diseases induced by radiation therapy of cervix cancer are about 0.8%-2.96%, with an average of 2.14%. Radiation bladder disease is divided into acute radiation cystitis, chronic radiation cystitis and radiation vesical fistula. Chronic radiation cystitis is seen most often in the clinic and its main clinical symptom is painless macroscopic hematuria, which is again subdivided into slight and severe degrees. Diagnosis should include history of exposure to radiation, which dose exceed the dose threshold, and typical clinical characteristics. Conclusion: The characteristics, types and diagnostic basis of radiation urinary bladder disease analyzed in this study can provide the reference for drawing up diagnostic standard

Detection of microcalcifications by characteristic magnetic susceptibility effects using MR phase image cross-correlation analysis

Energy Technology Data Exchange (ETDEWEB)

Baheza, Richard A. [Department of Biomedical Engineering and Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee 37232-2310 (United States); Welch, E. Brian [Institute of Imaging Science and Departments of Radiology and Radiological Sciences and Biomedical Engineering, Vanderbilt University, Nashville, Tennessee 37232-2310 (United States); Gochberg, Daniel F. [Institute of Imaging Science and Departments of Radiology and Radiological Sciences, and Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37232-2310 (United States); Sanders, Melinda [Department of Pathology, Vanderbilt University, Nashville, Tennessee 37232-2310 (United States); Harvey, Sara [Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee 37232-2310 (United States); Gore, John C. [Institute of Imaging Science and Departments of Biomedical Engineering, Radiology and Radiological Sciences, Physics and Astronomy, and Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee 37232-2310 (United States); Yankeelov, Thomas E., E-mail: thomas.yankeelov@vanderbilt.edu [Institute of Imaging Science and Departments of Radiology and Radiological Sciences, Biomedical Engineering, Physics and Astronomy, and Cancer Biology, Vanderbilt University, Nashville, Tennessee 37232-2310 (United States)

2015-03-15

Purpose: To develop and evaluate a new method for detecting calcium deposits using their characteristic magnetic susceptibility effects on magnetic resonance (MR) images at high fields and demonstrate its potential in practice for detecting breast microcalcifications. Methods: Characteristic dipole signatures of calcium deposits were detected in magnetic resonance phase images by computing the cross-correlation between the acquired data and a library of templates containing simulated phase patterns of spherical deposits. The influence of signal-to-noise ratio and various other MR parameters on the results were assessed using simulations and validated experimentally. The method was tested experimentally for detection of calcium fragments within gel phantoms and calcium-like inhomogeneities within chicken tissue at 7 T with optimized MR acquisition parameters. The method was also evaluated for detection of simulated microcalcifications, modeled from biopsy samples of malignant breast cancer, inserted in silico into breast magnetic resonance imaging (MRIs) of healthy subjects at 7 T. For both assessments of calcium fragments in phantoms and biopsy-based simulated microcalcifications in breast MRIs, receiver operator characteristic curve analyses were performed to determine the cross-correlation index cutoff, for achieving optimal sensitivity and specificity, and the area under the curve (AUC), for measuring the method’s performance. Results: The method detected calcium fragments with sizes of 0.14–0.79 mm, 1 mm calcium-like deposits, and simulated microcalcifications with sizes of 0.4–1.0 mm in images with voxel sizes between (0.2 mm){sup 3} and (0.6 mm){sup 3}. In images acquired at 7 T with voxel sizes of (0.2 mm){sup 3}–(0.4 mm){sup 3}, calcium fragments (size 0.3–0.4 mm) were detected with a sensitivity, specificity, and AUC of 78%–90%, 51%–68%, and 0.77%–0.88%, respectively. In images acquired with a human 7 T scanner, acquisition times below 12

Characteristics of the stress-induced formation of R-phase in ultrafine-grained NiTi shape memory wire

International Nuclear Information System (INIS)

Olbricht, J.; Yawny, A.; Pelegrina, J.L.; Eggeler, G.; Yardley, V.A.

2013-01-01

Highlights: •We investigated the stress-induced formation of R-phase in NiTi shape memory wires. •The R-phase related strains were isolated from the overall stress-strain-behavior. •The stress–strain characteristics of R-phase suggest a homogeneous transformation. •Thermography confirms the homogeneous R-phase formation in ultrafine-grained NiTi. -- Abstract: The transformation between the cubic B2 and monoclinic B19′ phases in ultrafine-grained pseudoelastic NiTi can occur as a two-step process involving the intermediate rhombohedral R-phase. Experimental work using differential scanning calorimetry, electrical resistance measurements and transmission electron microscopy has demonstrated the formation of this intermediate phase during thermal cycling and during mechanical loading. In the present paper, complementary mechanical and thermographic results are presented which allow to further assess the character of the stress-induced R-phase formation. The transformation from B2 to R-phase is demonstrated to occur homogeneously within the gauge length rather than via advancing Lüders-type transition regions as it is the case in the localized transformation from B2 or R-phase to B19′

The phase-change kinetics of amorphous Ge2Sb2Te5 and device characteristics investigated by thin-film mechanics

International Nuclear Information System (INIS)

Cho, Ju-Young; Kim, Dohyung; Park, Yong-Jin; Yang, Tae-Youl; Lee, Yoo-Yong; Joo, Young-Chang

2015-01-01

For high switching speed and high reliability of phase-change random access memory (PcRAM), we need to identify materials that enable fast crystallization at elevated temperatures but are stable at and above room temperature. Achieving this goal requires a breakthrough in our understanding of the unique crystallization kinetics of amorphous phase change materials as a fragile glass, described as the non-Arrhenius behavior of atomic mobility. It is a highly rewarding task to unravel the unconventional crystallization kinetics and related properties, because these properties can be utilized to predict the device characteristics. This manuscript utilizes the thin-film mechanics to investigate the crystallization kinetics of amorphous Ge 2 Sb 2 Te 5 phase-change materials doped with Al, Bi, C and N, which is an effective method to analyze the structural changes in amorphous materials. Crystallization temperature, super-cooled liquid region, glass transition temperature and fragility are measured to describe the crystallization kinetics tuned by doping; characteristic fragile-to-strong transition is observed for C and N dopings due to their structural feature as an interstitial dopant. Consequently, doping effects on the phase stability and atomic mobility manifested by the crystallization temperature and the super-cooled liquid region (or 1/fragility) successfully correspond with PcRAM characteristics, i.e., reliability and switching speed, respectively

Ecological physiological characteristic of some species of natural vegetation in the Poles'e State Radiation Ecological Reservation

International Nuclear Information System (INIS)

Kravchenko, V.A.; Gaponenko, V.I.; Matsko, V.P.; Grushevskaya, O.M.; Bondar', Yu.I.; Evsievich, K.M.; Akadehmiya Navuk Belarusi, Minsk

1996-01-01

Influence of radiation on important ecological and physiological characteristics of Pinus silvestris L., Phleum pratense L. and Dactylis glomerata L. growing on territory of the Poles'e State Radiation Ecological Reservation has been investigated in 1992-1994. Significant changes in species and quantitative formation of natural vegetation growing on territory contaminated by the Chernobyl accident release were not observed. Positive correlation between the content of protein in needles of Pinus silvestris L., leaves of Agropyron repens L. and specific radioactivity of photosystem was established. Positive correlation between specific radioactivity of overground photosystem and quantity of nucleic acids (DNA+RNA) is leaves of Dactylis glomerata was found. 8 refs., 2 tabs., 2 figs

Radiation chemistry

Energy Technology Data Exchange (ETDEWEB)

None

1973-07-01

Research progress is reported on radiation chemistry of heavy elements that includes the following topics: radiation chemistry of plutonium in nitric acid solutions (spectrophotometric analysis and gamma radiolysis of Pu(IV) and Pu(VI) in nitric acid solution); EPR studies of intermediates formed in radiolytic reactions with aqueous medium; two-phase radiolysis and its effect on the distribution coefficient of plutonium; and radiation chemistry of nitric acid. (DHM)

Analysis of conduction–radiation heat transfer during phase change process of semitransparent materials using lattice Boltzmann method

International Nuclear Information System (INIS)

Maroufi, Arman; Aghanajafi, Cyrus

2013-01-01

This article deals with the analysis of solidification of a 2-D semitransparent material using the lattice Boltzmann method (LBM). Both conduction and radiation terms in governing energy equation were computed using the LBM. First, the LBM formulation regarding conduction component was validated and the results analyzed. Next, the results involving phase change or radiation term in the LBM were compared with the finite volume method (FVM). The results show good accuracy and less time consumption during LBM implementation. Finally, temperature distribution, the location of solid-liquid front, mushy zone thickness and the effects of heat transfer parameters were studied. -- Highlights: ► Solidification of 2-D semitransparent material is studied. ► Both conduction and radiation were computed using lattice Boltzmann method (LBM). ► LBM results validated by solving three benchmark problems. ► Effects of various parameters were studied on temperature distributions. ► Results show good accuracy and less time consumption during LBM implementation.

Effect of gamma radiation on the viable cell count and some other quality characteristics of dried onions

International Nuclear Information System (INIS)

Farkas, J.; El-Nawawy, A.S.

1973-01-01

The results of experiments carried out with onion powder and flakes of Egyptian origin show a radiation treatment of 0.1-0.2 Mrad sufficient to reduce the microbial contamination of dried onions by one order of magnitude. To achieve a 99% reduction, satisfactory from the practical point of view, treatment with 0.5-0.6 Mrad seems necessary. With increasing radiation doses the characteristic smell of dried onions diminished and a caramel-like off-odour appeared and the colour of the dried products darkened. These changes become significant only above treatment with 0.8 Mrad. The differences between radiation treated and untreated samples both packed in Cellothene pouches were either eliminated (odour) or diminished (colour) during 6 weeks storage following irradiation. The results obtained by the chemical oxygen demand method (COD) based on bichromate oxidation of water soluble volatile reducing substances, were not in accord with the organoleptically observable changes of odour. (F.J.)

Study on self-regulation characteristics of closed two-phase thermo-siphon for cold neutron source

International Nuclear Information System (INIS)

Shen Feng; Yuan Luzheng

2006-01-01

A self-regulation model and its characteristics of closed two-phase thermosiphon loop, which including buffer tank, were proposed, under the conditions of adiabatic and transient temperature balance for connect tube between buffer tank and condenser. The comparison between these models and the model from Kyoto University is conducted. Measures to improve the self-regulation are proposed. (authors)

The study of two-phase critical flow characteristics in nuclear reactor coolant system

International Nuclear Information System (INIS)

Chung, Moon Ki; Chang, Seok Kyu

1993-01-01

This report presents the physical characteristics of two-phase critical flow whcih can be occured in a light water nuclear power plant during LOCA and also reviews the critical flow models and their applications in detail. The existing experimental data base are reviewed and classified. The typical critical flow models which have been applied to the computer code for the accident are also reviewed. Some suggestions are presented for the development of advanced analytical models and the extension of useful experimental database. (Author)

Research on the electromagnetic radiation characteristics of the gas main switch of a capacitive intense electron-beam accelerator

Directory of Open Access Journals (Sweden)

Yongfeng Qiu

2017-11-01

Full Text Available Strong electromagnetic fields are radiated during the operation of the intense electron-beam accelerator (IEBA, which may lead to the nearby electronic devices out of order. In this paper, the research on the electromagnetic radiation characteristic of the gas main switch of a capacitive IEBA is carried out by the methods of theory analysis and experiment investigation. It is obtained that the gas main switch is the dominating radiation resource. In the absence of electromagnetic shielding for the gas main switch, when the pulse forming line of the IEBA is charged to 700 kV, the radiation field with amplitude of 3280 V/m, dominant frequency of 84 MHz and high frequency 100 MHz is obtained at a distance of 10 meters away from the gas main switch. The experimental results of the radiation field agree with the theoretical calculations. We analyze the achievements of several research groups and find that there is a relationship between the rise time (T of the transient current of the gas main switch and the dominant frequency (F of the radiation field, namely, F*T=1. Contrast experiment is carried out with a metal shield cover for the gas main switch. Experimental results show that for the shielded setup the radiation field reduces to 115 V/m, the dominant frequency increases to 86.5 MHz at a distance of 10 away meters from the gas main switch. These conclusions are beneficial for further research on the electromagnetic radiation and protection of the IEBA.

Remote Sensing and In-Situ Observations of Arctic Mixed-Phase and Cirrus Clouds Acquired During Mixed-Phase Arctic Cloud Experiment: Atmospheric Radiation Measurement Uninhabited Aerospace Vehicle Participation

International Nuclear Information System (INIS)

McFarquhar, G.M.; Freer, M.; Um, J.; McCoy, R.; Bolton, W.

2005-01-01

The Atmospheric Radiation Monitor (ARM) uninhabited aerospace vehicle (UAV) program aims to develop measurement techniques and instruments suitable for a new class of high altitude, long endurance UAVs while supporting the climate community with valuable data sets. Using the Scaled Composites Proteus aircraft, ARM UAV participated in Mixed-Phase Arctic Cloud Experiment (M-PACE), obtaining unique data to help understand the interaction of clouds with solar and infrared radiation. Many measurements obtained using the Proteus were coincident with in-situ observations made by the UND Citation. Data from M-PACE are needed to understand interactions between clouds, the atmosphere and ocean in the Arctic, critical interactions given large-scale models suggest enhanced warming compared to lower latitudes is occurring

INFLUENCE OF ULTRAVIOLET RADIATION ON MICROBIOLOGICAL AND SENSORY CHARACTERISTICS OF CERTAIN CATEGORIES OF VEGETABLES PRODUCTS AND THEIR PRESERVATION LIFE

Directory of Open Access Journals (Sweden)

Danilevici Constantin

2010-01-01

Full Text Available Research paper aims to highlight the scientific correlation between the influence of ultraviolet radiation (UV onsensory and microbiological characteristics of plant products in the category of leaves (lettuce and other types ofvegetables or fruit (bananas and their preservation’s duration, through their UV irradiation under certain conditions.The literature indicates a germicidal action of UV (medium UV on micro-organisms, optimal for λ = 254 nm. Theeffectiveness of radiation is influenced by duration of irradiation, the distance between the radiation source and thesample product and radiant power source.The action of microbial cell inactivation or destruction can be explained by changes in cellular structure andpermeability with changes at the level of mitochondria and the genetic material as a result of photochemical effects ofUV products. Research highlights the preservative effect of UV radiation (with λ = 254 nm and also their influence onsensory properties and positive to negative for leafy vegetables and fruits (bananas in our case.

Radiation Effects on Thermoluminescence Characteristics of HDPE Containing Additives

International Nuclear Information System (INIS)

Kim, Ki Yup; Lee, Chung; Ryu, Boo Hyung

2005-01-01

Polymeric materials are widely used for electrical insulation in a broad range of applications that cover the power supply industry to inner and outer space. However, the electrical performance of these materials could be compromised by their working environment and one of the most deleterious is that where a nuclear radiation is present. Radiation effects on polymers can be interpreted by two main reactions, a cross-linking reaction and degradation reactions or a main-chain scission process. There are no absolute rules for determining whether or not any given polymer will cross-link or degrade upon an irradiation. But, the polymers can be divided empirically into two groups; polymers which are crosslinked by radiation (especially by the incorporation of chemical cross-linking promoters) and polymers which degrade by radiation into a product of lower molecular weight due to random main-chain scission process. These polymers become very hard and brittle with a high dose of radiation. Most polymeric materials contain some stabilizers such as flame retardant and antioxidant to prevent combustion and oxidation. Because of these additives, degradation mechanism of the polymer became complicated. Many of the novel properties of the insulating materials used in nuclear power plants are important for radiation degradation. Therefore we have used the thermal methods such as thermoluminescence (TL) detection for irradiated high density polyethylene containing flame retardant and antioxidant

Environmental mobility of cobalt-Influence of solid phase characteristics and groundwater chemistry

International Nuclear Information System (INIS)

Payne, T.E.; Itakura, T.; Comarmond, M.J.; Harrison, J.J.

2009-01-01

The adsorption of cobalt on samples from a potential waste repository site in an arid region was investigated in batch experiments, as a function of various solution phase parameters including the pH and ionic strength. The samples were characterized using a range of techniques, including BET surface area measurements, total clay content and quantitative X-ray diffraction. The statistical relationships between the measured cobalt distribution coefficients (K d values) and the solid and liquid phase characteristics were assessed. The sorption of cobalt increased with the pH of the aqueous phase. In experiments with a fixed pH value, the measured K d values were strongly correlated to the BET surface area, but not to the amount of individual clay minerals (illite, kaolinite or smectite). A further set of sorption experiments was undertaken with two samples of distinctive mineralogy and surface area, and consequently different sorption properties. A simple surface complexation model (SCM) that conceptualized the surface sites as having equivalent sorption properties to amorphous Fe-oxide was moderately successful in explaining the pH dependence of the sorption data on these samples. Two different methods of quantifying the input parameters for the SCM were assessed. While a full SCM for cobalt sorption on these complex environmental substrates is not yet possible, the basic applicability and predictive capability of this type of modeling is demonstrated. A principal requirement to further develop the modeling approach is adequate models for cobalt sorption on component mineral phases of complex environmental sorbents.

Phase coherence among the Fourier modes and non-Gaussian characteristics in the Alfvén chaos system

Science.gov (United States)

Nariyuki, Yasuhiro; Sasaki, Makoto; Kasuya, Naohiro; Hada, Tohru; Yagi, Masatoshi

2017-03-01

Non-Gaussian characteristics in time series of the Alfvén chaos system are discussed. The phase coherence index, a measure defined by using the surrogate data method and the structure function, is used to evaluate the phase coherence among the Fourier modes. Through Monte Carlo significance testing, it is found that the phase coherence decays monotonically with increasing dissipative parameter and time scale. By applying the Mori projection operator method assuming the Markov process, a model equation for the time correlation function is derived from the generalized Langevin equation. As opposed to the result of the phase coherence analysis, it is concluded that the difference between the direct numerical simulation and the model equation becomes pronounced as the dissipative parameters are increased. This suggests that, even when the phase coherence index is not significant, the underlying physical system may be a non-Gaussian process.

DEVELOPMENT OF CONCEPT OF HARDWARE-SOFTWARE COMPLEX OF MODULAR DESIGN FOR DETERMINATION OF ANTENNA SYSTEMS׳ CHARACTERISTICS BASED ON MEASUREMENTS IN THE NEAR FIELD

Directory of Open Access Journals (Sweden)

A. G. Buday

2017-01-01

Full Text Available Measuring the amplitude-phase distribution of the radiation field of complex antenna systems on a certain surface close to the radiating aperture allows solving the problem of reconstructing the free-space diagram in the far field and also helps in determining the influence of various structural elements and defects of radiating surfaces on formation of directional diagram. The purpose of this work was to develop a universal hardware-software complex of a modular design aimed for determining the characteristics of wide range of antenna systems in respect of measurements of the amplitude-phase distribution of the radiation field in the near zone.The equations that connect the structure of radiation fields of the antenna system at various distances from it in planar, cylindrical and spherical coordinate systems as well as structural diagrams of the hardware part of measuring complexes have been analyzed.As a result, the concept of constructing a universal hardware-software complex for measuring the radiation field of various types of antenna systems with any type of measurement surface for solving a wide range of applied problems has been developed. A modular structure of hardware and software has been proposed; it allows reconfiguring the complex rapidly in order to measure the characteristics of any particular antenna system at all stages of product development and testing, and also makes the complex economically accessible even for small enterprises and organizations.

Temporal and spatial evolution characteristics of gas-liquid two-phase flow pattern based on image texture spectrum descriptor

Science.gov (United States)

Zhou, Xi-Guo; Jin, Ning-De; Wang, Zhen-Ya; Zhang, Wen-Yin

2009-11-01

The dynamic image information of typical gas-liquid two-phase flow patterns in vertical upward pipe is captured by a highspeed dynamic camera. The texture spectrum descriptor is used to describe the texture characteristics of the processed images whose content is represented in the form of texture spectrum histogram, and four time-varying characteristic parameter indexes which represent image texture structure of different flow patterns are extracted. The study results show that the amplitude fluctuation of texture characteristic parameter indexes of bubble flow is lowest and shows very random complex dynamic behavior; the amplitude fluctuation of slug flow is higher and shows intermittent motion behavior between gas slug and liquid slug, and the amplitude fluctuation of churn flow is the highest and shows better periodicity; the amplitude fluctuation of bubble-slug flow is from low to high and oscillating frequence is higher than that of slug flow, and includes the features of both slug flow and bubble flow; the slug-churn flow loses the periodicity of slug flow and churn flow, and the amplitude fluctuation is high. The results indicate that the image texture characteristic parameter indexes of different flow pattern can reflect the flow characteristics of gas-liquid two-phase flow, which provides a new approach to understand the temporal and spatial evolution of flow pattern dynamics.

Radiation metagenesis and inhibition of DNA synthesis

International Nuclear Information System (INIS)

Dubinina, L.G.; Sergievskaya, S.P.; Kurashova, Z.I.; Dubinin, N.P.

1983-01-01

The study of modification of radiation mutagenesis and inhibition of the DNA synthesis by means of 1-β-D arabinofuranosylcytosine (ara-C) is carried out. It is shown that ara-C-acting on chromosomes in the G 1 phase and G 2 phase does not cause mutations in the C capillaris cells. The modification by means of ara-C radiation effect in the G 1 phase and G 2 phase correlates with duration and time of administering ara-C before and after irradiation. A new form of ara-C DNA synthesis inhibitor interaction with mutation processes has been found out. Protective effect of the DNA synthesis inhibitor (ara-C) from mutageneous radiation effect is stressed. Sensibilization of the radiation mutagenesis during cell treafment by the DNA synthesis inhibitor (ara-C) is shown. It is pointed out that emergence of sensibilization or protective effect, i. e. antimutagenesis phenomenon depends on conditions under which the synthesis inhibitor acted in G 1 and G 2 phases

Pregnancy and ionizing radiation

International Nuclear Information System (INIS)

Plataniotis, Th.N.; Nikolaou, K.I.; Syrgiamiotis, G.V.; Dousi, M.; Panou, Th.; Georgiadis, K.; Bougias, C.

2008-01-01

Full text: In this report there will be presented the effects of ionizing radiation at the fetus and the necessary radioprotection. The biological results on the fetus, caused by the irradiation, depend on the dose of ionizing radiation that it receives and the phase of its evolution. The imminent effects of the irradiation can cause the fetus death, abnormalities and mental retardation, which are the result of overdose. The effects are carcinogenesis and leukemia, which are relative to the acceptable irradiating dose at the fetus and accounts about 0,015 % per 1 mSv. The effects of ionizing radiation depend on the phase of the fetus evolution: 1 st phase (1 st - 2 nd week): presence of low danger; 2 nd phase (3 rd - 8 th week): for doses >100 mSv there is the possibility of dysplasia; 3 rd phase (8 th week - birth): this phase concerns the results with a percentage 0,015 % per 1 mSv. We always must follow some rules of radioprotection and especially at Classical radiation use of necessary protocols (low dose), at Nuclear Medicine use of the right radioisotope and the relative field of irradiation for the protection of the adjacent healthy tissues and at Radiotherapy extreme caution is required regarding the dose and the treatment. In any case, it is forbidden to end a pregnancy when the pregnant undergoes medical exams, in which the uterus is in the beam of irradiation. The radiographer must always discuss the possibility of pregnancy. (author)

The effects of radiative heat transfer during the melting process of a high temperature phase change material confined in a spherical shell

International Nuclear Information System (INIS)

Archibold, Antonio Ramos; Rahman, Muhammad M.; Yogi Goswami, D.; Stefanakos, Elias K.

2015-01-01

Highlights: • Analyzed effects of radiation heat transfer during melting in spherical shell. • Performed analyses to ascertain the effects of optical thickness and the Planck, Grashof and Stefan numbers. • Present correlations for melt fraction and modified Nusselt number. - Abstract: The influence of radiation heat transfer during the phase change process of a storage material has been numerically analyzed in this study. Emphasis has been placed on the thermal characterization of a single constituent storage module rather than an entire storage system, in order to precisely capture the energy exchange contributions of all the fundamental heat transfer mechanisms during the melting of a phase change material (PCM) with tailored optical properties. The equations describing the conservation of mass, momentum and energy have been solved by using the control volume discretization approach, while the radiative transfer equation (RTE) was solved by the discrete ordinate method (DOM). The enthalpy–porosity method was used to track the PCM liquid/solid interface during the process. A parametric analysis has been performed in order to ascertain the effects of the optical thickness and the Planck, Grashof and Stefan numbers on the melting rate, as well as the total and radiative heat transfer rates at the inner surface of the shell. The results show that the presence of thermal radiation enhances the melting process. Correlations for the melt fraction and modified Nusselt number are developed for application in the design process of packed bed heat exchangers for latent heat thermal energy storage

THERMAL CHARACTERISTICS OF PHASE CHANGE MATERIAL USED AS THERMAL STORAGE SYSTEM BY USING SOLAR ENERGY

Directory of Open Access Journals (Sweden)

Kadhim F. Nasir

2018-01-01

Full Text Available In this paper, the melting processes of phase change material in a shell and tube heat exchanger by using solar thermal energy have been investigated numerically and experimentally. All experimental were outdoor tested at AL-Mussaib city-Babylon-Iraq (Lat 32.5 º North, and long 44.3 º East with N-S collector direction at tilt angle of 32.5 º with the horizontal. The phase change material used in this work is black color Iraqi origin pure Paraffin with amount of 12 kg. In the experimental setup evacuted tube solar collector is employed for melting phase change material in shell regime. Different volume flow rates for the water flow inside the inner tube of heat exchanger namely (200, 300, and 500 LPH for Reynolds number namely (15000, 23000, 38000 respectively were used for each season from August 2016 to January 2017. The numerical investigation involves a three dimension numerical solution of model by a commercial package ANSYS FLUENT 15.0. The boundary conditions of the model that solved by the numerical solution have been taken from the experimental tests. The experimental results indicated that the inner tube inlet and ambient temperatures has a significant effects on the melting process compared with the volume flow rates. Studying phase change material temperature distribution, it is exposed that a melting temperature of the phase change material in summer season needed time of (3-4 hours only, while it needed more time; (14-16 hours in winter season. Increasing solar radiation and ambient temperature reduces the melting time of phase change material. Increasing water temperature difference of inner tube increased the heat gained for phase change material. The results obtained from numerical solution presented the static temperature contours and showed that the temperature distribution of phase change material give good validations with experimental results with percentage deviation of 2.7%. The present experimental results have been

The technique on handling radiation

International Nuclear Information System (INIS)

1997-11-01

This book describes measurement of radiation and handling radiation. The first part deals with measurement of radiation. The contents of this part are characteristic on measurement technique of radiation, radiation detector, measurement of energy spectrum, measurement of radioactivity, measurement for a level of radiation and county's statistics on radiation. The second parts explains handling radiation with treating of sealed radioisotope, treating unsealed source and radiation shield.

Effect of phase formation on valence band photoemission and photoresonance study of Ti/Ni multilayers using synchrotron radiation

International Nuclear Information System (INIS)

Bhatt, Pramod; Chaudhari, S.M.

2006-01-01

This paper presents investigation of Ti-Ni alloy phase formation and its effect on valence band (VB) photoemission and photoresonance study of as-deposited as well as annealed Ti/Ni multilayers (MLs) up to 600 deg. C using synchrotron radiation. For this purpose [Ti (50 A)/Ni (50 A)]X 10 ML structures were deposited by using electron-beam evaporation technique under ultra-high vacuum (UHV) conditions. Formation of different phases of Ti-Ni alloy due to annealing treatment has been confirmed by the X-ray diffraction (XRD) technique. The XRD pattern corresponding as-deposited ML sample shows crystalline nature of both Ti and Ni deposited layers, whereas 300 deg. C annealed ML sample show solid-state reaction (SSR) leading to amorphization and subsequent recrystallisation at higher temperatures of annealing (≥400 deg. C) with the formation of TiNi, TiNi 3 and Ti 2 Ni alloy phases. The survey scans corresponding to 400, 500 and 600 deg. C annealed ML sample shows interdiffusion and intermixing of Ni atoms into Ti layers leading to chemical Ti-Ni alloys phase formation at interface. The corresponding recorded VB spectra using synchrotron radiation at 134 eV on as-deposited ML sample with successive sputtering shows alternately photoemission bands due to Ti 3d and Ni 3d, respectively, indicating there is no mixing of the consequent layers and any phase formation at the interface during deposition. However, ML samples annealed at higher temperatures of annealing, particularly at 400, 500 and 600 deg. C show a clear shift in Ni 3d band and its satellite peak position to higher BE side indicates Ti-Ni alloy phase formation. In addition to this, reduction of satellite peak intensity and Ni 3d density of states (DOS) near Fermi level is also observed due to Ti-Ni phase formation with higher annealing temperatures. The variable photon energy VB measurements on as-deposited and ML samples annealed at 400 deg. C confirms existence and BE position of observed Ni 3d satellite

Radiators in hydronic heating installations structure, selection and thermal characteristics

CERN Document Server

Muniak, Damian Piotr

2017-01-01

This book addresses key design and computational issues related to radiators in hydronic heating installations. A historical outline is included to highlight the evolution of radiators and heating technologies. Further, the book includes a chapter on thermal comfort, which is the decisive factor in selecting the ideal heating system and radiator type. The majority of the book is devoted to an extensive discussion of the types and kinds of radiators currently in use, and to identifying the reasons for the remarkable diversity of design solutions. The differences between the solutions are also addressed, both in terms of the effects of operation and of the thermal comfort that needs to be ensured. The book then compares the advantages and disadvantages of each solution, as well as its potential applications. A detailed discussion, supported by an extensive theoretical and mathematical analysis, is presented of the computational relations that are used in selecting the radiator type. The dynamics of radiator hea...

Investigation of physical image characteristics and phenomenon of edge enhancement by phase contrast using equipment typical for mammography

International Nuclear Information System (INIS)

Yamazaki, Asumi; Ichikawa, Katsuhiro; Kodera, Yoshie

2008-01-01

A technique called phase contrast mammography (PCM) has only recently been applied in clinical examination. In this application, PCM images are acquired at a 1.75x magnification using an x-ray tube for clinical use, and then reduced to the real size of the object by image processing. The images showed enhanced object edges; reportedly, this enhancement occurred because of the refraction of x rays through a cylindrical object. The authors measured the physical image characteristics of PCM to compare the image characteristics of PCM with those of conventional mammography. More specifically, they measured the object-edge-response characteristics and the noise characteristics in the spatial frequency domain. The results revealed that the edge-response characteristics of PCM outperformed those of conventional mammography. In addition, the characteristics changed with the object-placement conditions and the object shapes. The noise characteristics of PCM were better than those of conventional mammography. Subsequently, to verify why object edges were enhanced in PCM images, the authors simulated image profiles that would be obtained if the x rays were refracted and totally reflected by using not only a cylindrical substance but also a planar substance as the object. So, they confirmed that the object edges in PCM images were enhanced because x rays were refracted irrespective of the object shapes. Further, they found that the edge enhancements depended on the object shapes and positions. It was also proposed that the larger magnification than 1.75 in the commercialized system might be more suitable for PCM. Finally, the authors investigated phase-contrast effects to breast tissues by the simulation and demonstrated that PCM would be helpful in the diagnoses of mammography.