The Neutral Beam Test Facility (NBTF) to be realized in Padoa will test the Neutral Beam Injection (NBI), one of the Heating and Current Drive Systems foreseen for ITER. The NBI is based on the acceleration of hydrogen or deuterium negative ions up to 1 MeV. This work has been aimed at assessing the tritium release from the NBTF in order to provide data for the safety analysis. In particular, the diffusion of the tritium through the neutral beam target material (the CuCrZr alloy calorimeter panels) has been assessed by using literature data of the diffusion coefficient. The tritium generated inside the calorimeter panels moves into both the vacuum and water side: the tritium diffusion flux has been evaluated during the beam-on (200 deg. C) and the beam-off (20 deg. C) phases of the NBTF experiments consisting of an interim campaign and a final test. The penetration depth of the ...
The Neutral Beam Test Facility (NBTF) to be realized in Padoa will test the Neutral Beam Injection (NBI), one of the Heating and Current Drive Systems foreseen for ITER. The NBI is based on the acceleration of hydrogen or deuterium negative ions up to 1 MeV. This work has been aimed at assessing the tritium release from the NBTF in order to provide data for the safety analysis. In particular, the diffusion of the tritium through the neutral beam target material (the CuCrZr alloy calorimeter panels) has been assessed by using literature data of the diffusion coefficient. The tritium generated inside the calorimeter panels moves into both the vacuum and water side: the tritium diffusion flux has been evaluated during the beam-on (200 deg. C) and the beam-off (20 deg. C) phases of the NBTF experiments consisting of an interim campaign and a final test. The penetration depth of the ...
One of the design targets for the ITER Tokamak Exhaust Processing system is not to lose more than 10{sup -5} g h{sup -1} into the Normal Vent Detritiation System of the Tritium Plant. The plasma exhaust gas, therefore, needs to be processed in a way that an overall tritium removal efficiency of about 10{sup 8} is reached. Such a high decontamination factor can only be achieved by multistage processes. The third step of the three step CAPER process developed at the TLK is based on a so-called permeator catalyst (PERMCAT) reactor, a direct combination of a Pd/Ag permeation membrane and a catalyst bed. The PERMCAT principle is based on isotopic swamping in a counter current mode. Previous tritium experiments employing laboratory scale PERMCAT reactors have revealed decontamination factors as high as 10{sup 5} for the third CAPER step. First tritium tests with a technical scale PERMCAT ...
One of the design targets for the ITER Tokamak Exhaust Processing system is not to lose more than 10"-"5 g h"-"1 into the Normal Vent Detritiation System of the Tritium Plant. The plasma exhaust gas, therefore, needs to be processed in a way that an overall tritium removal efficiency of about 10"8 is reached. Such a high decontamination factor can only be achieved by multistage processes. The third step of the three step CAPER process developed at the TLK is based on a so-called permeator catalyst (PERMCAT) reactor, a direct combination of a Pd/Ag permeation membrane and a catalyst bed. The PERMCAT principle is based on isotopic swamping in a counter current mode. Previous tritium experiments employing laboratory scale PERMCAT reactors have revealed decontamination factors as high as 10"5 for the third CAPER step. First tritium tests with a technical scale PERMCAT reactor led to ...
The vacuum polarization splitting of the M-shell states in muonic hydrogen can have a profound influence on the muonit de-excitation cascade in deuterium and tritiumtargets. The cascade also shows sensitive dependence on the precise rate of transfer processes between certain excited muonic deuterium and tritium atoms. Recent experimental data, where a much greater population of the (d..mu..) qs state (1/sub 1//sub //sub s/) was found than previously predicted, can be explained if the transfer rates from the (d..mu..) M-shell are assumed to be strongly suppressed.
Design improvements are being incorporated into the heavy water management systems at Wolsong 2,3 and 4 to reduce the load on the vapour recovery driers and upgraders and the heavy water losses via the stack. There will also be improvements to monitor heavy water and tritium releases. This paper describes the improvements, gives background on heavy water balance mechanism, the historical trends for heavy water recovery/losses and estimated dose to the member of the public critical group resulting from the airborne and waterborne releases. The measured tritium activity levels in the heat transport system (HTS) and moderator system at Wolsong 1 are given. Using these activity levels and heavy water loss data, tritium losses from the dried and ventilated areas are estimated. A qualitative assessment of expected heavy water and tritium releases has been performed for Wolsong 2, 3 and 4. CANDU 6 plants ...
Single pellets (of approximately 70 g each) of irradiated lithium aluminate target from N-Reactor test PT-57 were used in a series of experiments to determine the extent to which the product tritium can be recovered by (a) vacuum outgassing of the target (thermal extraction-TX) and (b) in-vacuo chemical dissolution of the target in molten sodium tetraborate (flux extraction-FX). Five TX runs and seven FX runs were made. Thirty-five percent of the tritium was recovered in a form non-condensable at -196"0C. The remainder was recovered in a condensable form (as T_2O, HTO, etc.). Post-extraction analysis of the melt from the seven flux extractions showed that a maximum of 2 percent of the original amount of tritium remained and that target dissolution was essentially complete in 12 hours. Flux extraction of two pellets which had been subjected ...
... Targeted fields of research Continuation of ongoing research - Finalising detailed design work on the ITER project; getting JET operational at full power; Improvement of the basic concepts of fusion devices - Fusion plasmas; theoretical studies; technology watch on research into inertial confinement; new experimental concepts and systems; etc.; Long-term technology - Preparations for building a demonstration reactor (development of tritium breeding blankets; prospective ...
33 patients with advanced malignant melanoma were studied after intravenous administration of 131I-labeled Fab fragments specific for p97, an oncofetal glycoprotein of human melanoma. In all, 47 gamma...Full Text Available
LLNL is developing the nuclear fusion based Laser Inertial Fusion Energy (LIFE) power plant concept. The baseline design uses a depleted uranium (DU) fission fuel blanket with a flowing molten salt coolant (flibe) that also breeds the tritium needed to sustain the fusion energy source. Indirect drive targets, similar to those that will be demonstrated on the National Ignition Facility (NIF), are ignited at 13Hz providing a 500MW fusion source. The DU is in the form of a uranium oxycarbide kernel in modified TRISO-like fuel particles distributed in a carbon matrix forming 2-cm-diameter pebbles. The thermal power is held at 2000MW by continuously varying the 6Li enrichment in the coolants. There are many options to be considered in the engine design including target yield, U-to-C ratio in th...
A calorimetric sensor with several novel design features has been developed. These sensors will provide an accurate sampling of thermal power density and energy deposition from proton beams incident on target components of accelerator-based systems, such as the Accelerator Production of Tritium Project (APT) and the Spallation Neutron Source (SNS). A small, solid slug (volume = 0.347 cc) of target material is suspended by kevlar fibers and surrounded by an adiabatic enclosure in an insulating vacuum canister of stainless steel construction. The slug is in thermal contact with a low-mass, calibrated, 100-k{Omega} thermistor. Power deposition caused by the passage of radiation through the slug is calculated from the rate of temperature rise of the slug. The authors have chosen slugs composed of Pb, Al, and LiAl.
In case of operating both Wolsung Nuclear Units 1 and 2 without operating tritium removal facilities, it is estimated that tritium in 2013 would be accumulated up to about 30 million Ci that would result in about 2,300 man-rem of tritium exposure to opera...
Apparatus and method for selective measurement of tritium oxide in an environment which may include other radioactive components and gamma radiation, the measurement including the selective separation of tritium oxide from a sample gas through a membrane into a counting gas, the generation of electrical pulses individually representative by rise times of tritium oxide and other radioactivity in the counting gas, separation of the pulses by rise times, and counting of those pulses representative of tritium oxide. The invention further includes the separate measurement of any tritium in the sample gas by oxidizing the tritium to tritium oxide and carrying out a second separation and analysis procedure as described above.
The market potential for the fan atomized burner (FAB) in water and space heating applications was examined. The major findings of the study are as follows. (1). The FAB`s low-input capability allows development of oil-fired room heaters and wall furnaces, a new market area for oil heat. (2). Among conventional oil-fired products, furnaces will benefit most from the burner`s low input capability due to (1) their quick delivery of heat and (2) their more prevalent use in warmer climates and smaller homes. (3). The greatest potential for increased product sales or oil sales exists in the use of the burner with new products (i.e., room heaters). Sales of boilers and direct-fired water heaters are not likely to increase with the use of the burner. (4). Acceptance of the burner will be dependent on proof of reliability. Proof of better reliability than conventional burners would accelerate acceptance.
The agglutination of human platelets by ristocetin and von Willebrand factor was inhibited by aggregated immunoglobulin (Ig)G and by Fc fragments of IgG, but not by Fab, F(ab′)2 or...Full Text Available
Building on the concepts of MIRD methods described by Webber, Watson and others at this Symposium on the Dosimetry of Administered Radionuclides, we will now consider how to apply these principles to several experimentally based open-quote macroclose quotes and multicellular models. Specifically, methods to calculate absorbed dose using different types of particulate emission (alpha, beta) with a variety of antibody carriers (IgG, F(ab')_2, Fab) for radioimmunotherapy (RIT) will be reviewed. Additionally, a discussion of direct measurement methods at the multicellular level will reveal the problems of tumor absorbed dose heterogeneity when applied to animal and clinical studies.
The induced radioactivity in the construction materials of a Cockcroft-- Walton type neutron generator was measured. Major activation products (/sup 24/ Na, /sup 28/Al, /sup 56/Mn, /sup 64/Cu, /sup 65/Ni, /sup 69m/Zn, /sup 88/Rb /sup 91/Sr /sup 101/Mo, /sup 187/W/ and resulting doses are tabulated. Results show that the highest gamma activities would be observed in the fluorescent bulbs, copper pipe, aluminum lattice rod, and the aluminum pipe clamp. Thermoluminescent dosimeter readings yield the highest doses for the copper pipe tee, copper pipe, and aluminum lattice rod. Results of measuremerts of the neutron and gamma dose profiles of the facility are shown. However the indication is clearly that the tritiumtarget, compared to other components, is the major source of radiation both during and after shutdown. (UK)
In order to decrease tritium exposure to workers, the ratio of which is up to 40% of total exposure, tritium removal facility is getting to be one of the considerable parameters in Korea, due to the next CANDUs to be operated at Wolsung NPP. For investiga...
While tritium exposure to the site-workers in Wolsung NPP is up to about 40% of the total personnel exposure, Ministry of Science and Technology has asked tritium removal facility for requirement of post heavy-water reactor construction. For the purpose o...
At Wolsung NPP, three more CANDU reactors will be operated soon, and the tritium accumulation in the moderator and coolant systems was estimated to be greatly increased. In order to reduce tritium exposure for nuclear safety at Wolsung, a study was carrie...
The BEATRIX-II irradiation experiment is an in-situ tritium release experiment being carried out in the Fast Flux Test Facility (FFTF) reactor to evaluate the tritium release characteristics of fusion solid breeder materials. A sophisticated tritium gas handling system has been developed to continuously monitor the tritium recovery from the specimens and facilitate tritium removal from the experiment's sweep gas flow stream. The in-situ recovery experiment accommodates two different in-reactor specimen canisters with individual gas streams and temperature monitoring/control. Ionization chambers have been specifically designed to respond to the rapid changes in the tritium release rate at the anticipated tritium concentrations. Two ceramic electrolysis cells have proved effective in reducing the moisture in the gas streams to ...
In this paper uptake of tritium by market foods from tritiated water vapor in the air is investigated using cereals and beans purchased in Deep River, Canada. The concentrations of tissue free water tritium (TFWT) and organically bound tritium (OBT) range from 12 to 79% and from 10 to 38% respectively, of that estimated for atmospheric water vapor of the sampling month. The specific activity ratios of OBT to TFWT were constant for cereals, but variable for beans. The elevated OBT was shown to be the result of isotopic exchange of labile hydrogen by the fact that washing the foods with tritium free-water reduced their tritium contents to levels characteristic of their production sites.
A critical issues study of a symmetric illumination, direct drive laser fusion reactor called SIRIUS has been conducted. In particular, the uniformity requirements for direct drive targets have been assessed and it is shown that respectable gains (more than 60) could be obtained at modest (2MJ) KrF laser energies. Previous ICF cavity designs have been examined for use in a symmetric illumination geometry and features from several designs have been combined into a dry wall cavity design with a radius of 8 meters. Neutronic and photonic analysis shows that the present SIRIUS cavity design can breed sufficient tritium (breeding ratio = 1.17) even with 32 laser ports penetrating the cavity. However, it was found that there are a few critical issues that remain to be solved before a self-consistent reactor design could be initiated. Radiation damage to final optics, thermal performance of SiC tiles on the SIRIUS cavity wall, and performance of ...
LLNL is developing the nuclear fusion based Laser Inertial Fusion Energy (LIFE) power plant concept. The baseline design uses a depleted uranium (DU) fission fuel blanket with a flowing molten salt coolant (flibe) that also breeds the tritium needed to sustain the fusion energy source. Indirect drive targets, similar to those that will be demonstrated on the National Ignition Facility (NIF), are ignited at #approx#13 Hz providing a 500 MW fusion source. The DU is in the form of a uranium oxycarbide kernel in modified TRISO-like fuel particles distributed in a carbon matrix forming 2-cm-diameter pebbles. The thermal power is held at 2000 MW by continuously varying the "6Li enrichment in the coolants. There are many options to be considered in the engine design including target yield, U-to-C ratio in the fuel, fission blanket thickness, etc. Here we report results of design variations and compare them in terms of various ...
During the water detritiation process most of the tritium inventory is transferred from water into the gaseous phase, then it is further enriched and finally extracted and safely stored. The control of tritium inventory is an acute issue from several points of view: - Financially - tritium is an expensive material; - Safeguard - tritium is considered as nuclear material of strategic importance; - Safety - tritium is a radioactive material: requirements for documented safety analysis report (to ensure strict limits on the total tritium allowed) and for evaluation of accident consequences associated with that inventory. Large amounts of tritium can be stored, in a very safely manner, as metal tritides. A bench-scale experiment of a tritium storage bed with integrated system for in-situ tritium ...
The tri-n-butyl phosphate(TBP) extraction behavior of tritium was studied to support the evaluation of tritium confinement in the Purex process. The tritium distribution ratio in the system of U - 30% TBP/n-dodecane(nDD) - HNO[sub 3] [minus]H[sub 2]O was measured in batch-wise experiments. The tritium decontamination factor in a tritium scrubbing step was measured in chemical flow sheet experiments using a 6 stage mixer-settler having an internal recycle system of aqueous solution in each stage. Tritium was mainly extracted in the forms of water and nitric acid in the system. Less than 1% of the amount of tritium in the organic phase was fixed in the degradation products of the solvent. A tritium decontamination factor of about 500 in the tritium scrubbing step was obtained under the conditions of ...
A fusion reactor (such as NET/ITER) which breeds its own tritium fuel requires tritium recovery, purification and separation from the other isotopes. Cyclic adsorption processes are strong candidates for several of the processes involved: amongst other advantages, they promise a low tritium inventory. A good adsorbent for such processes must have high adsorption capacity, high selectivity and very low tritium retention after each cycle. Pure zeolite powder is shown to have an excellent combination of these three properties. However, in practice problems can arise from tritium which is not removed by reactivation. In this paper we show that tritium retention in zeolites can be caused either by water retained in the zeolite structure, which can be removed by ore rigorous activation, or by water tapped on binders in commercial pellets. (orig.).
An experimental verification for long-term performance of a Pd-Ag permeation in ITER tritium fusion cleanup units (FCU) is needed. In addition, information is required on the influence of tritium and {sup 3}He decay on the physical and chemical properties of Pd-Ag alloys (V-1). The results of the investigations of alloys (V-1) (mechanical properties and microstructure) after long-term usage exposition in tritium are given in this report. The experimental conditions (temperature, pressure, clearance, {sup 3}He concentrations) and the previous conclusions on the V-1 alloy performance are presented. (orig.).
This report is the first revision to a series of reports on radionuclides inn the SRS environment. Tritium was chosen as the first radionuclide in the series because the calculations used to assess the dose to the offsite population from SRS releases indicate that the dose due to tritium, through of small consequence, is one of the most important the radionuclides. This was recognized early in the site operation, and extensive measurements of tritium in the atmosphere, surface water, and ground water exist due to the effort of the Environmental Monitoring Section. In addition, research into the transport and fate of tritium in the environment has been supported at the SRS by both the local Department of Energy (DOE) Office and DOE`s Office of Health and Environmental Research.
The "1"3"1I-labelled monoclonal antibodies 791T/36 and 79IT/36 Fab fragments have been evaluated in the imaging of patients with colorectal cancer, with benign colorectal tumours, and with malignant tumours of other parts of the gastrointestinal tract. The results of clinical imaging have been carefully correlated with clinical findings and direct measurement of the preferential uptake of antibody by the tumours. (UK).
Fatty acid biosynthesis is crucial for all living cells. In contrast to higher organisms, bacteria use a type II fatty acid synthase (FAS II) composed of a series of individual proteins, making...Full Text Available
This report provides the results of a JASON review of the technical feasibility of using the Department of Energy`s (DOE`s) Fast Flux Test Facility (FFTF) to generate tritium needed for the enduring United States nuclear weapons stockpile.
Concentrations of tritium in environmental waters (precipitation, rivers, lakes, tap water) have been determined using electrolytic enrichment and liquid scintillation counting. In waters of big rivers (the Vistula and the Odra rivers), lakes and tap water the annual average concentrations were similar to each other being from 1.4 to 1.9 Bq x dm"-"3. These concentrations were similar to those in the precipitation in which they ranged from 1.7 to 2.2 Bq x dm"-"3. The lowest tritium concentrations were found in waters of the Seashore Region rivers (average for 1994-1999 was 1.1 Bq x dm"-"3). The tritium concentrations in surface waters and in precipitation are still higher than that of natural level. The data obtained show that tritium concentration in the water of rivers might depend on the size of drainage area. The observed seasonal variations of tritium concentration in the ...
In an attempt to obtain basic data for evaluation of exposure doses in Niigata Prefecture, the concentrations of tritium in atmospheric water, precipitation, river water, and tap water were measured. Samples of atmospheric water, river water, and tap water were collected once for 2 weeks; and precipitation collected for one week was used as sample. The concentration of atmospheric tritium depended on the concentration of tritium in moisture and the content of water in atmosphere. Tritium levels were high in May, November and March, and low in September. Regarding tritium concentrations, there was a good correlation between atmospheric water and precipitation. Tritium concentrations in both of them varied from sample to sample. The concentrations of tritium in river and tap water tended to be high during spring and low during summer and ...
Liquid Phase Catalytic Exchange (LPCE)- Cryogenic Distillation(CD) process was studied which could be available for an optimal tritium removal process of pressurized heavy water reactor system at Wolsung nuclear power plant in the near future. Based upon ...
Tritium removal from tritiated heavy water in a PHWR is the most effective way in reducing workers` internal dose and radioactivity emissions from Wolsong NPP. The optimum design of the Wolsung TRF(Tritium Removal Facility) was carried out using an approximate short-cut method with an assumption that the TRF, designed to extract 8 MCi per year of elemental tritium from a heavy water feedstream, uses Liquid Phase Catalytic Exchange (LPCE) front-end process and Cryogenic Distillation (CD) process. 19 refs., 6 figs., 2 tabs. (author).
Tritium removal from tritiated heavy water in a PHWR is the most effective way in reducing workers' internal dose and radioactivity emissions from Wolsong NPP. The optimum design of the Wolsung TRF(Tritium Removal Facility) was carried out using an approximate short-cut method with an assumption that the TRF, designed to extract 8 MCi per year of elemental tritium from a heavy water feedstream, uses Liquid Phase Catalytic Exchange (LPCE) front-end process and Cryogenic Distillation (CD) process. 19 refs., 6 figs., 2 tabs. (author).
It has been reported by the present authors that behavior of tritium release from solid breeder grain is consisted of diffusion in grain, tritium transfer at surface layer and surface reactions on grain surface such as adsorption or isotope exchange reactions. Tritium release curves estimated using the tritium release model gave good agreement with observed tritium release curves from Li{sub 4}SiO{sub 4}, Li{sub 2}ZrO{sub 3} or LiAlO{sub 2}. Tritium release behavior from Li{sub 2}TiO{sub 3} under humid purge gas, dry purge gas and dry purge gas with hydrogen conditions is discussed in this study, tritium release curves using the release model that we proposed previously give a good agreements with experimental tritium release curves. Tritium effective diffusivity in the crystal grain of Li{sub ...
It has been reported by the present authors that behavior of tritium release from solid breeder grain is consisted of diffusion in grain, tritium transfer at surface layer and surface reactions on grain surface such as adsorption or isotope exchange reactions. Tritium release curves estimated using the tritium release model gave good agreement with observed tritium release curves from Li_4SiO_4, Li_2ZrO_3 or LiAlO_2. Tritium release behavior from Li_2TiO_3 under humid purge gas, dry purge gas and dry purge gas with hydrogen conditions is discussed in this study, tritium release curves using the release model that we proposed previously give a good agreements with experimental tritium release curves. Tritium effective diffusivity in the crystal grain of Li_2TiO_3 is also estimated in this study using ...
The present report concerns a research for the tritium and for the carbon 14 in lichens in a spirit of bio-indication: the first results appear in Daillant and al (2004 ) and additional results were presented to the congress B.I.O.M.A.P. in Slovenia, organized collectively by the institute Josef Stefan from Ljubljana and the international atomic energy agency from Vienna (Daillant and al 2003). (N.C.)
Tritium is produced in large quantities at heavy water nuclear power reactors via the neutron activation reaction "2H(n,#gamma#)"3H. At Wolsung nuclear power plant which has a CANDU reactor, the tritium concentrations in coolant and in moderator systems are 1.5 Ci/Kg-D_2O and 35 Ci/kg-D_2O, respectively, after 12 years of operation. The airborne tritium concentration in main access area is normally less than 5 MPCa except short-term peaks. The average tritium concentrations in main access controlled areas are normally less than 100 MPCa. Tritium is mainly present in the air of workplace of CANDU reactors as a tritiated water vapour. Airborne tritiated water vapour enters the workers body via inhalation and absorption through skin and can result in a significant dose. The occupational doses from tritium at Wolsung NPP have been maintained below 1 man-Sv per year ...
Tritium occurs in nature in trace amounts, but its concentration is changing due to natural and artificial sources. Studies focusing on natural tritium have to take into account the effect of artificial sources. Also, the impact of tritium is an important issue in environmental protection, e.g. in connection with the emissions from nuclear power plants. The present work focuses on the rain washout of tritium emitted from the Paks nuclear power plant in Hungary. Rainwater collectors were placed around the plant and after a period of precipitation, rainwater was collected and analysed for tritium content. Samples were analysed using low-level liquid scintillation counting, with some also subject to the more accurate "3He ingrowth method. The results clearly show the trace of the tritium plume emitted from the plant; however, values are only about one order of ...
An estimate of the tritium dose to the public in the vicinity of the heavy water research reactor facility at AECL-Chalk River Laboratories, Ontario, Canada, has largely been accomplished from analyses on regularly-collected samples of air, precipitation, drinking water and foodstuffs (pasture, fruit, vegetables and milk) and environmental dose models. To increase the confidence with which public doses are calculated, tritium doses were estimated directly from the ratio of tritiated species in urine samples from members of the general public. Single cumulative 24 h urine samples from a few adults living in the vicinity of the heavy-water research reactor facility at Chalk River Laboratories, Canada were collected and analysed for tritiated water and organically bound tritium. The participants were from Ottawa (200 km east), Deep River (10 km west) and Chalk River Laboratories. Tritiated water concentrations in urine ranged ...
A meeting was held on October 15, 16, 17, 1990 to discuss the state of tritium safety and environmental effects. The meeting was organized with the help of the International Energy Agency planning committee consisting of K. Steinmetz, Y. Seki, G. Nardella, and G. Vivian. Representative of tritium production facilities and heavy water reactor power production were also involved. The meeting was organized to address seven topics in tritium safety that were thought to require further work. The topics were: (1) materials science, (2) environmental models, (3) environmental model validation, (4) tritiated organic compounds, (5) human dosimetry, (6) tritium sampling and measurement, and (7) long-term environmental databases.
Tarapur Atomic Power Station unit-4 is first 540 MWe pressurized heavy water reactor. Heavy water is used as the coolant and moderator. With reactor operation tritium is formed by absorption of neutron by Deuterium atoms. Experience in the 220 MWe indicates that tritium is main contributor to the internal dose of radiation workers. Study on Tritium build up in Primary Heat Transport (PHT) and Moderator (MOD) system was carried out at the initial stage of the operation of the unit-3 and 4. This paper brings out tritium activity buildup in the PHT and MOD systems and its comparison with 220 MWe reactors. This paper helps in estimation of the internal dose contribution to the radiation workers at TAPS 3 and 4. (author)
Tarapur Atomic Power Station unit-4 is first 540 MWe pressurized heavy water reactor. Heavy water is used as the coolant and moderator. With reactor operation tritium is formed by absorption of neutron by deuterium atoms. Experience in the 220 MWe indicates that tritium is main contributor to the internal dose of radiation workers. Study on tritium build up in Primary Heat Transport (PHT) and Moderator (MOD) system was carried out at the initial stage of the operation of the unit-4. This paper brings out tritium activity buildup in the PHT and MOD systems and its comparison with 220 MWe reactors. This paper helps in estimation of the internal dose contribution to the radiation workers at TAPS 3 and 4. (author)
Full text: In heavy-water-moderated power reactors, tritium is primarily produced by neutron capture in deuterium nuclei in the moderator and coolant. For CANDU 6 reactors, the estimated steady-state values are #approx# 3 TBq#centre dot#kg"-"1 D_2O in the moderator and #approx# 74 GBq#centre dot#kg"-"1 D_2O in the coolant. Tritium removal is one option available to reactor operators for use in their heavy water and tritium management strategies. The WTRF is designed to remove tritium from tritiated heavy water in each of the four CANDU units at the Wolsung Site, to immobilize the tritium and to store it on site. The detritiation process is based on three steps: the first one (front-end) involves the transfer of tritium from heavy water to deuterium gas; the second one (enrichment) concentrates the tritium in a cryogenic distillation system ...
This paper proposes a model to explain tritium release behavior of an irradiated Li_4SiO_4 sample made by Forschungszentrum Karlsruhe. The release curves were obtained in a series of experiments carried out using out-pile temperature programmed desorption techniques in the Kyoto University Reactor (KUR). Tritium release curves obtained for different purge gas compositions (N_2, N_2 + H_2, N_2 + H_2O) were compared for selection of suitable conditions to determine the apparent diffusivity of tritium in a crystal grain of Li_4SiO_4.In the model formation, some mass transfer steps in the bulk of the crystal grain and those on the surface of the grain were taken into account, which were diffusion of tritium in the grain, adsorption and desorption of water on the surface of the grain, two types of isotope exchange reactions, and water formation reaction by the addition of hydrogen to the purge ...
For the inventory of water tritium concentration in the Manche department, it is the complementarity that animated the work opened during year 2001. To answer to a commune sensitivity such water quality, particularly drinking water at tap, the A.C.R.O. laboratory brought its know how to make and its technical means in the area of tritium analysis and the general council brought its know how to make and its logistics means in matter of sanitary control. This collaboration has allowed to supply an indication on the tritium content of the distribution waters of thirty of the most important cities of the department. Then, it allowed to inform on the radiological situation (in relation with the tritium presence) of coast waters and principal rivers waters. More than 160 controls have been realised between the months of march 2001 and february 2002. Only the tritium under the shape of ...
The distribution of environmental tritium and the correlation coefficients between tritium concentrations in several environmental samples and the emissions of tritiated water vapor from Wolsong NPP 1 were studied. The annual mean concentrations of atmospheric HTO were in the range 1#centre dot#31-29#centre dot#2 Bq m"-"3 and the long-term atmospheric dilution factors were in the range 10"-"7-10"-"6 s m"-"3. Annual mean concentrations of tritium in ground water were in the range 19#centre dot#2-27#centre dot#9 Bq l"-"1 at N-1 and 64#centre dot#1-189 Bq l"-"1 at S-2, and were generally less than 0#centre dot#2% of MPC_w (222 kBq l"-"1). The concentrations of tritium in precipitation decreased exponentially with distance from Wolsong NPP 1, falling to current global levels at about 25 km off-site. The highest concentration of tritium in soil moisture was observed in May and June, when ...
Several materials, lenses, dry bearings and cables were exposed to a tritiated moisture environment to study the behavior of tritium contamination on candidate materials for ITER remote handling equipment. To optimize the tritium removal procedure, decontamination experiments using a gas purge with three different moisture concentrations were also performed. The surface tritium concentrations of CeO{sub 2} containing alkaline barium glass (NB), CeO{sub 2} containing lead glass (LX) and synthetic quartz (Quartz) after the exposure experiments were 7.80, 10.94 and 0.67 Bq/cm{sup 2}, respectively. It was found that the tritium concentration was influenced by the compositions of the materials. The concentrations of tritium on type 831 (solid lubrication material: graphite) and type 237 (solid lubrication material: tungsten disulfate) dry bearings after the exposure experiments were ...
Several materials, lenses, dry bearings and cables were exposed to a tritiated moisture environment to study the behavior of tritium contamination on candidate materials for ITER remote handling equipment. To optimize the tritium removal procedure, decontamination experiments using a gas purge with three different moisture concentrations were also performed. The surface tritium concentrations of CeO_2 containing alkaline barium glass (NB), CeO_2 containing lead glass (LX) and synthetic quartz (Quartz) after the exposure experiments were 7.80, 10.94 and 0.67 Bq/cm"2, respectively. It was found that the tritium concentration was influenced by the compositions of the materials. The concentrations of tritium on type 831 (solid lubrication material: graphite) and type 237 (solid lubrication material: tungsten disulfate) dry bearings after the exposure experiments were 89.80 and 31.78 ...
12 kind of environmental samples such as soil, underground water, seawater, etc. around the Nuclear Power Plants(NPP) and surface seawater around the Korea peninsula were sampled, For the samples of rain, pine-needle, air, seawater, underground water, chinese cabbage, grain of rice and milk sampled around NPP, and surface seawater and rain sampled all around country, tritium concentration was measured, The tritium concentration in the tap water and the gamma activity in the domestic and imported beef that were sampled at ward in the large city in Korea(Seoul, Pusan, Taegu, Taejun, Inchun, Kwangju) were analyzed for the meat and drinking waters. As the results of analyzing, tritium concentration in rain and tap water were very low all around country, but a little higher around the NPP than general surrounding. At the Wolsung NPP, tritium concentration was descend according to distance from the stack. ...
For the estimation of the dispersion trend of tritium discharged from the Wolsung nuclear power plant, the present level of tritium in environmental samples in the vicinity of the Wolsong site has been studied. On the basis of tritium concentrations in environmental samples, the effective dose due to tritium has been estimated for an individual and population within a 16 km radius from the Wolsong site. The annual effective dose of tritium to an inhabitant around the Wolsong site ranged from 0.15 microSv y-1 to 1.3 microSv y-1. The dose level was negligible and much lower than some applicable standards, i.e. the limit on exposure from nuclear fuel cycle to the general public as recommended by ICRP (1 mSv y-1) or US EPA's limit (0.25 mSv y-1). The collective dose to the total population within a 16 km radius from the site, 1.2 x 10(-2) man.Sv y-1 was much lower than 1 man.Sv y-1, an ...
Tritium dose management is an important aspect of the radiation protection program at CANDU type reactor sites. This paper describes the bioassay and dosimetry of tritium at CANDU reactor sites, especially for Wolsung Nuclear Power Plant. It presents a compilation of information drawn from published papers, technical reports, international and national guidelines as well as practical experience both in Korean and Canadian CANDU Nuclear Power Plants. The implementation of this program would provide a technical basis for calculations and records should be of acceptable quality and should meet overall radiation protection program objectives.
A procedure for high level tritium labelling at the C2-H position of adenosine 5`-triphosphate ([2-{sup 3}H]-ATP, 1), based on the tritiodehalogenation reaction of 2-bromoadenosine 5`-triphosphate (2) has been elaborated. This precursor was prepared in a six-step synthesis from guanosine. The tritiodehalogenation of (2) for three hours over palladium oxide in phosphate buffer yielded tritium labelled ATP with high specific activity, in good chemical yield. (author).
As part of the start up of Los Alamos National Laboratory's new tritium-handling facility, the efficiency of a catalytic oxidation tritium decontamination system was investigated using deuterated methane. The tests were performed during the start up of the facility to confirm the operability of the system before introducing tritium and to provide a baseline for comparison. Techniques and instruments normally used for atmospheric tracer experiments using deuterated methane were applied virtually without modification. The sensitivity of this method allowed preliminary checks at the sub-ppm (v/v) level.
This is the monthly progress report for the Savannah River Technology Center, which covers the following areas of interest, Tritium, Separation processes, Environmental Issues, and Waste Management.
This document details monthly activities at the Savannah River Laboratory. Topics addressed are reactor operation; tritium facilities and production; separation operations; environmental concerns; and waste management. (FI)
This document details monthly activities at the Savannah River Laboratory. Topics addressed are reactor operation; tritium facilities and production; separation operations; environmental concerns; and waste management. (FI)
The U.S. Department of Energy Order 435.1, Radioactive Waste Management, requires a disposal authorization statement authorizing operation (or continued operation) for low-level waste disposal facilities. In fulfillment of these requirements, a disposal authorization statement was issued on October 25, 1999, authorizing the Hanford Site to transfer, receive, possess, and dispose of low-level radioactive waste at the 200 East Area burial grounds and the 200 West Area burial grounds. One of the conditions is that monitoring plans for the 200 East Area and 200 West Area low-level burial grounds be written and approved by the Richland Operations Office. As a result of a record of decision for the Hanford Site Solid Waste Program and acceptance of the Hanford Site Solid Waste Environmental Impact Statement, the use of the low-level burial ground (LLBG) as a disposal facility for low-level and mixed low-level wastes has been restricted to lined trenches and the Navy reactor-compartment ...
The philosophy of containing tritium and activated products very close to the source and of operating by remote techniques is justified by a comparison with other concepts on protection and availability points of view. Several design options are studied according to the optimization protection methodology of ICRP. Provided that an important technological development is accomplished, the utilization of robotics and the limitation of containment volumes should be generalized.
The tritium in transpired water of plant leaves from four locations within site area (2=0.92) with that of measured values indicating that at Tarapur, the contribution to TFWT of plant is only from air activity and pick up through soil route is negligible during the period of study. (author)
A Lagrangian atmospheric dispersion model(K-LADM) combining a three dimensional sea-land breeze model has been developed and applied to the estimation of the quaterly and the annual averaged air tritium concentration around Wolsung NPP site. The estimated concentrations were compared with the observed concentration data. The results showed that the present Lagrangian Atmospheric dispersion model(K-LADM) provided very good agreement with the observations.
The Full Aperture Backscatter System (FABS) provides a measure of the spectral power, and integrated energy scattered by stimulated Brillouin (348-354 nm) and Raman (400 - 700 nm) scattering into the final focusing lens of the first four beams of the NIF laser. The system was designed to provide measurements at the highest expected fluences with: (1) spectral and temporal resolution, (2) beam aperture averaging, and (3) near-field imaging. This is accomplished with a strongly attenuating diffusive fiber coupler and streaked spectrometer and separate calibrated time integrated spectrometers, and imaging cameras. Measurement of the wavelength dependent sensitivity of the complete system is accomplished with a calibrated Xe lamp. Data from the calibration system is combined with experimental data to produce the power and energy measurements. Examples of measurements will be discussed.
A 2-stage cold (non-tritium) PMR system was tested with the ITER mix in61 days of continuous operation. No decrease in performance was observed over the duration of the test. Decontamination factor (DF) was found to increase with decreasing inlet rate. Decontamination factors in excess of 1.4 {times} 10{sup 5} were obtained, but the exact value of the highest DF could not be determined because of analysis limitations. Results of the 61-day test were used to design a 2-stage PMR system for use in tritium testing. The PMR system was scaled up by a factor of 6 and built into a glovebox in the Tritium Systems Test Assembly (TSTA) of the Los Alamos National Laboratory. This system is approximately 1/5th of the expected full ITER scale. The ITER mix was injected into the PMR system for 31 hours, during which 4.5 g of tritium were processed. The 1st stage had DF = 200 and the 2nd stage had DF = 2.9 {times} ...
A 2-stage cold (non-tritium) PMR system was tested with the ITER mix in 61 days of continuous operation. No decrease in performance was observed over the duration of the test. Decontamination factor (DF) was found to increase with decreasing inlet rate. Decontamination factors in excess of 1.4x10"5 were obtained, but the exact value of the highest DF could not be determined because of analysis limitations. Results of the 61-day test were used to design a 2-stage PMR system for use in tritium testing. The PMR system was scaled up by a factor of 6 and built into a glovebox in the Tritium Systems Test Assembly (TSTA) of the Los Alamos National Laboratory. This system is approximately 1/5"t"h of the expected full ITER scale. The ITER mix was injected into the PMR system for 31 hours, during which 4.5 g of tritium were processed. The 1"s"t stage had DF =200 and the 2"n"d stage had DF=2.9x10"6. The overall ...
SiC has been considered as a primary candidate material for a first wall component in future fusion reactor because it has been claimed that SiC has excellent high-temperature properties, good chemical stability and low activation. However, the behavior of tritium on SiC has not been discussed yet. In this study, tritium trapping capacity on the surface of SiC was experimentally obtained at the temperature range of 25-800 deg. C in consideration of tritium trapping to the experimental system. The capacity, which was independent of the water vapor pressure in the gas phase and the temperature, was determined as about 10{sup 6} Bq/cm{sup 2}. The isotope exchange reaction rate between tritiated water in a gas phase and hydrogen on the surface was quantified at the temperature of 25, 500 and 700 deg. C in consideration of the behavior of tritium trapping at change of experimental condition by the numerical ...
SiC has been considered as a primary candidate material for a first wall component in future fusion reactor because it has been claimed that SiC has excellent high-temperature properties, good chemical stability and low activation. However, the behavior of tritium on SiC has not been discussed yet. In this study, tritium trapping capacity on the surface of SiC was experimentally obtained at the temperature range of 25-800 deg. C in consideration of tritium trapping to the experimental system. The capacity, which was independent of the water vapor pressure in the gas phase and the temperature, was determined as about 10"6 Bq/cm"2. The isotope exchange reaction rate between tritiated water in a gas phase and hydrogen on the surface was quantified at the temperature of 25, 500 and 700 deg. C in consideration of the behavior of tritium trapping at change of experimental condition by the numerical curve ...
Tritium, a beta emitting gas at room temperature causes a biological hazard in the locations where it is present beyond acceptable limits. The hazard can be due to inhalation, and absorption by skin. Hence is the necessity of Tritium monitoring instruments/systems for ensuring safety in the PHWRs and the nuclear research plants and laboratories. It is desirable that the instruments address satisfactorily to certain factors like the following: (i) Wide range of Tritium concentrations - 1 to 104 DAC ( Derived Air Concentration) (ii) On-line monitoring features (iii) Small response time (On-spot instantaneous measurements) (iv) Portability (v) Mitigation of memory effects. This paper presents an overview of the Online Tritium in Air Monitoring Systems manufactured by ECIL for Pressurised Heavy Water Reactors at Tarapur, Kaiga, and Rawatbhata. Significant aspects of design, function, testing, limitations of ...
The ELEX process for isotopic enrichment and separation of tritium from aqueous reprocessing effluents is described. After the development of an appropriate hydrophobic catalyst and the study of the separate constituent steps of the ELEX process, an integrated bench-scale installation with a detritiation capacity of 10 mol water per hour was constructed. It comprises essentially a 1.5 kW electrolyser and two 2 cm diameter by 3 m high exchange columns. In this mini-pilot the ELEX process was successfully demonstrated by detritiating more than 1000 dm"3 water containing up to 100 mCi tritium per dm"3, which is the feed concentration expected for application of the process in a reprocessing plant. The process decontamination factor was always larger than 100 and the overall tritium balance could be kept within the experimental errors of the various measurements. Depending on the duration of the runs, the volume reduction ...
This report for the month of June 1995 presents information on the typical topics of tritium processing, environmental studies, waste management issues, and miscellaneous projects. The document consists many small reports by individuals or small groups.
Nuclear energy provides a third of Europe's electricity with nearly no greenhouse-gas emissions. Sustained efforts are now being conducted to harmonize regulations all over Europe through WENRA and to converge on technical nuclear safety practices within the TSO network ETSON (European Technical Safety Organizations Network). In CANDU type NPP the tritiated water occurs by the neutron bombardment of deuterium. The tritiated water vapors imply health hazard (in the critical organs of the body the water presents a 10 day average biological half-life) and the early detection in nuclear plants of tritium emissions is important because the tritiated water vapors have the same characteristics as of atmospheric water vapors. By detecting tritiated vapors, the monitoring system ensures the following objectives: (a) indicates levels of tritium generally due to heavy water leakage, (b) reduces the possibility of health hazard. In order to attain this ...
During second quarter 1992, tritium, trichloroethylene, tetrachloroethylene, chloroethene, antimony, 1,1-dichloroethylene, lead, nonvolatile beta, radium-228, thorium-228, or total alpha-emitting radium (radium-226 and radium-228) exceeded the US Environmental Protection Agency Primary Drinking Water Standards (PDWS) in groundwater samples from monitoring wells at the Mixed Waste Management Facility (MWMF) and adjacent facilities. Tritium and trichloroethylene were the most widespread constituents; 55 (48%) of the 115 monitored wells contained elevated tritium activities, and 23 (20%) wells exhibited elevated trichloroethylene concentrations. Sixty-three downgradient wells screened in Aquifer Zone IIB2 (Water Table), Aquifer Zone IIB[sub 2] (Barnwell/McBean), and Aquifer Unit IIA (Congaree) contained concentrations of tritium, trichloroethylene, tetrachloroethylene, chloroethene, antimony, ...
Quantities and compositions of non-tritium radioactive waste are estimated for some current conceptual fusion reactor designs, and disposal of large amounts of radioactive waste appears necessary. Although the initial radioactivity of fusion reactor and f...
It was previously reported that the tritium tracer method is useful for the quantitative consideration of hydrogen behavior in coal during coal liquefaction reaction. Tetralin is excellent hydrogen donating solvent, and is considered as one of the model compounds of coal. In this study, effects of H2S and H2O on the hydrogen exchange reaction between tetralin and gaseous hydrogen labeled by tritium were investigated. It was suggested that the conversion of tetralin and the hydrogen exchange reaction between gaseous hydrogen and tetralin proceed through the radical reaction mechanism with a tetralyl radical as an intermediate product. When H2S existed in this reaction, the hydrogen exchange yield increased drastically without changing the conversion yield. This suggested that the hydrogen exchange reaction proceeds even in the reaction where radical does not give any effect. In the case of H2O addition, the conversion yield and hydrogen exchange ...
Volume VII of the documentation for the Phase I Data Analysis Task performed in support of the current Regional Flow Model, Transport Model, and Risk Assessment for the Nevada Test Site Underground Test Area Subproject contains the tritium transport model documentation. Because of the size and complexity of the model area, a considerable quantity of data was collected and analyzed in support of the modeling efforts. The data analysis task was consequently broken into eight subtasks, and descriptions of each subtask's activities are contained in one of the eight volumes that comprise the Phase I Data Analysis Documentation.
The Fuels Material Examination Facility/Fuel Assembly Area is proposed to be used for fabrication of mixed oxide fuel to support the Fast Flux Test Facility (FFTF) tritium/medical isotope mission. The plutonium isotope mix for the new mission is different than that analyzed in the FMEF safety analysis report. A reanalysis was performed of three representative accidents for the revised plutonium mix to determine the impact on the safety analysis. Current versions computer codes and meterology data files were used for the analysis. The revised accidents were a criticality, an explosion in a glovebox, and a tornado. The analysis concluded that risk guidelines were met with the revised plutonium mix.
Full text of publication follows: Slightly over-stoichiometric lithium orthosilicate pebbles have been selected as one optional breeder material for the European Helium Cooled Pebble Bed (HCPB) blanket. This material has been developed in collaboration of Research Center Karlsruhe and the Schott Glass, Mainz. The lithium orthosilicate pebbles are fabricated from lithium hydroxide and silica by a melting and spraying method in a semi-industrial scale facility. Lithium hydroxide was selected as the precursor since enriched lithium hydroxide is commercially available. The lithium orthosilicate pebbles produced by the process contains oxide phases besides orthosilicate, but it was also found that the oxide phases can be decomposed by annealing at high temperatures. The lithium orthosilicate pebbles produced in this way possesses satisfactory pebble characteristics. Therefore, the authors performed out-of-pile annealing tests using the lithium orthosilicate pebbles irradiated in a research ...
The chemical fixation of tritium in stearic acid followed by embedding the tritiated stearic acid into an epoxy resin proved to be a good method for permanent waste disposal of tritium gas. Tc-126 and Tc-136 hardener were used for this purpose. The polymerization temperature of the polymer products was found to be highly decreased by adding stearic acid and slightly decreased by adding stearic acid or by raising the temperature of the leachant medium and slightly decreased by irradiation. On the other hand, small improvement in the compressive strength of the polymer products was achieved by adding silica powder. The polymer product showed high flame points above 573 K although it contains stearic acid. DTA and TG analysis indicate that the thermal stability of polymer products containing stearic acid and silica powder is better than samples containing only stearic acid. Stearic acid was found to possess good resistance to irradiation and the ...
This study of the hydrogeology of Chicken Creek Canyon wasconducted by the Environmental Restoration Program (ERP) at LawrenceBerkeley National Laboratory (LBNL). This canyon extends downhill fromBuilding 31 at LBNL to Centennial Road below. The leading edge of agroundwater tritium plume at LBNL is located at the top of the canyon.Tritium activities measured in this portion of the plume during thisstudy were approximately 3,000 picocuries/liter (pCi/L), which issignificantly less than the maximum contaminant level (MCL) for drinkingwaterof 20,000 pCi/L established by the Environmental ProtectionAgency.There are three main pathways for tritium migration beyond theLaboratory s boundary: air, surface water and groundwater flow. Thepurpose of this report is to evaluate the groundwater pathway.Hydrogeologic investigation commenced with review of historicalgeotechnical reports including 35 bore logs and 27 test pit/trench logsas ...
While tritium exposure to the site-workers in Wolsung NPP is up to about 40% of the total personnel exposure, Ministry of Science and Technology has asked tritium removal facility for requirement of post heavy-water reactor construction. For the purpose of essential removal of tritium from the Wolsung heavy-water reactor system, a preliminary study on the cryogenic Ar-N{sub 2} and H{sub 2}-D{sub 2} distillation process for development of liquid-phase catalytic exchange cryogenic hydrogen distillation process technology. The Ar-N{sub 2} distillation column showed good performance with approximately 97% of final Ar concentration, and a computer simulation code was modified using these data. A simulation code developed for cryogenic hydrogen isotopes (H{sub 2}, HD, D{sub 2}, HT, DT, T{sub 2}) distillation column showed good performance after comparison with the result of a JAERI code, and a H{sub 2}-D{sub 2} distillation ...
All microRNA (miRNA) target—finder algorithms return lists of candidate target genes. How valid is that output in a biological setting? Transcriptome analysis has proven to be a useful approach...Full Text Available
Novel complexes of the type (Pt(DACH)(N-R-iminodiacetate)), wherein DACH represents (R,S)- and (R,R)-1,2 diaminocyclohexane and R represents /minus/Me, /minus/EtOH, and /minus/CH/sub 2/Ph groups, have been prepared, purified, and characterized by spectroscopic techniques (/sup 1/H, /sup 13/C, and /sup 195/Pt NMR;MS(FAB);IR) and by the measurement of selected physical properties (pH, pK/sub a/, conductivity, and molecular weights). The data are consistent with the formation of two diastereomeric complexes in unequal proportions in which the N-R-iminodiacetate ligand appears to be bonded as a pseudofacial tridentate chelate. One are of the ligand forms a stable five-membered-ring O,N-chelate while the other arm appears to be involved in ion-pair formation (zwitterion-like) involving the carboxylate anion and the formally positive Pt(II) central metal atom. It has been demonstrated indirectly that an active impurity was present in predictably inactive bulk complexes ...
A new monolithic semi-insulating (SI) GaAs sensor design for X-ray imaging applications between 10-100keV has been proposed. Monolithic pixel detectors offer a number of advantages over hybrid bump-bonded detectors, such as high device yield, low costs and are easier to produce large scale arrays. In this thesis, an investigation is made of the use of a SI GaAs wafer as both a detector element and substrate for the epitaxially grown High Electron Mobility Transistors (HEMTs). The design of the HEMT transistors, optimised for this application, were produced with the aid of the Silvaco 'Virtual Wafer Fab' simulation package. It was determined that the device characteristics would consist of a small positive threshold voltage, a low off-state drain current and high transconductance. The final HEMT transistor design, that would be integrated to a pixel detector, had a threshold voltage of 0.17V, an off-state leakage current of approx 1nA and a transconductance of ...
Two sup(99m)Tc complexes of (N-piperidinylethyl) hexamethyl diaminodithiol (NEP-DADT) have shown high brain uptake in rodents and lower primates. One of these sup(99m)Tc complexes has given positive images of the brain in man which are qualitatively related to regional brain blood flow (rCBF). In order to determine the structure of these sup(99m)Tc products, the corresponding /sup 99/Tc(NEP-DADT) complexes were prepared and characterized by HPLC, TLC, fast-atom-bombardment mass spectrometry (FAB MS) and other analytical techniques. These results indicate that the two /sup 99/Tc (NEP-DADT) complexes are syn and anti isomers (i.e. one isomer has the N-piperdinylethyl side chain located syn to the technetium oxo core while the other has this side chain located anti to the technetium oxo core).
Two sup(99m)Tc complexes of (N-piperidinylethyl) hexamethyl diaminodithiol (NEP-DADT) have shown high brain uptake in rodents and lower primates. One of these sup(99m)Tc complexes has given positive images of the brain in man which are qualitatively related to regional brain blood flow (rCBF). In order to determine the structure of these sup(99m)Tc products, the corresponding "9"9Tc(NEP-DADT) complexes were prepared and characterized by HPLC, TLC, fast-atom-bombardment mass spectrometry (FAB MS) and other analytical techniques. These results indicate that the two "9"9Tc (NEP-DADT) complexes are syn and anti isomers (i.e. one isomer has the N-piperdinylethyl side chain located syn to the technetium oxo core while the other has this side chain located anti to the technetium oxo core). (author).
In August 1982, a 44-year-old man was diagnosed as having rectal cancer, histologically diagnosed as well differentiated adenocarcinoma, and abdominoperineal resection and colostomy were performed. Postoperatively, he received chemotherapy with mitomycin C up to a total dose of 100 mg. In September 1986, lung metastasis occurred and he was treated with a combination chemotherapy consisting of cisplatin, pirarubicin and 5-fluorouracil. In the following year, radiation treatment (total: 6900 rad) was given for a recurrent pelvic lesion. Peripheral blood on April 30, 1988, showed anemia, thrombocytopenia and appearance of myeloblasts, and a diagnosis of acute myelogenous leukemia (FAB: M1) was made. Combination chemotherapy (including aclarubicin, vincristine, behenoyl ara-C, daunorubicin, 6-mercaptopurine, cytarabine, etoposide and prednisolone) failed to induce remission and the patient died in June 1988. This case was thought to be one of secondary leukemia ...
In most conceptual fusion power reactor designs, it is proposed to use beryllium as a neutron multiplier in the blanket. Detailed chemical composition of beryllium is necessary for evaluation of the tritium breeding ratio, and estimating the activation and transmutation of beryllium in the fusion reactor. In the present report, special attention was paid to a detailed analysis of impurities in beryllium, relevant to the tritium breeding ratio evaluation. Two different methods were used for the study of impurities: an analysis of the local sample by the ICP-MS method, and an integral analysis of the beryllium assembly, using the pulsed neutron method. The latter method was proposed as the most effective way of analyzing the integral effect to impurities in beryllium on production of the tritium on the lithium-6. The evaluation of the integral effect was based on time behaviour observations of the thermal neutron flux, ...
A clean benchmark experiment on beryllium was performed with D-T neutrons at the FNS facility of the Japan Atomic Energy Agency. The main objective was to verify the integral data related to the tritium production on lithium isotopes. Tritium production rates, as well as activation reaction rates were measured inside the beryllium assembly that was shaped as a pseudo-cylindrical slab with an area-equivalent diameter of 628 mm and a thickness of 355 mm. Experimental results were analyzed with a three-dimensional Monte Carlo transport code MCNP-4C and FENDL/MC-2.0, JENDL-3.2/3.3 neutron transport libraries. Evaluation of reaction rates was based on the cross section data taken from the JENDL Dosimetry File and ENDF B-VI data libraries. Analysis shows that all calculation combinations (transport and activation cross section libraries) used for evaluation of reaction rates give data that is agreeable with measured values within 10%.
This project was supported through ERDA to demonstrate that the temporal distribution of tritium can be documented by the analysis of bound hydrogen in annual tree-ring samples. The project focuses on two sample locations at the Savannah River Site (SRS), a nuclear material production facility located in Aiken, SC. The SRS provided samples of cross-sections from a single tree that were to be pooled together for analysis. Annual tree-rings were identified in each cross-section sample and separated for the period 1954 to 1993. These annual samples were ground and chemically treated to separate the hollocellulose fraction of the wood, then subsequently combusted and the resulting water counting using low-level liquid scintillation counting equipment. Additionally, the ground annual tree-rings were gamma-counted to determine any temporal variation in radionuclide activity and analyzed with x-ray fluorescence to find any temporal variation in trace-element ...
A conceptual fusion synfuel production system has been developed with the unique features of: (1) a fusion blanket producing high-temperature (1250"0C) process heat, and (2) the GA sulfur-iodine thermochemical cycle. The system incorporates a two-zone blanket which achieves a tritium breeding ratio of 1.1 while delivering a high fraction (30%) of the fusion heat at high temperatures (1250"0C). The multiple barriers to tritium permeation in the blanket design permit the hydrogen product to meet 10CFR20 regulatory requirements without stringent requirements on the tritium recovery systems. A ceramic heat exchanger, incorporating SiC tubes and headers to contain the process stream and a cooled, Inconel 718 pressure shell to contain the helium, was designed for transferring the heat from the high-temperature coolant to the process. A good heat-line match of the blanket heatsource temperature distribution to the requirements of ...
This paper introduces the radioactive effluent monitoring systems, measurement and quality control methods used in Daya Bay Nuclear Power Station from its commercial operation in 1994. The main work and experiences for the management of effluent release are discussed and analyzed. The radwaste data appear declining trend and are far blow the annual limit approved by the national Environmental Protection Bureau since 1995. The normalized release (unit GBq/GWa) of 9 years is as follows: liquid nuclides (except tritium) 11.1, liquid tritium 1.91 x 10"4, noble gas 2.03 x 10"4, halogen 0.13, aerosol 7.57 x 10"-"3. For "1"1"0"mAg, the average release from 1998 to 2002 has been reduced to 1/7 of the quantity in 1997
Author.The geochemical and isotopic study, based on the analysis of twenty water samples from well in the coastal plain of Sarafand (South-Lebanon), permit to eliminate the hypothesis of marine intrusion in this aquifer. The increase of salinity observed in certain wells is due to the contamination of cretaceous aquifer water by the quaternary formations. The two poles of mixing are respectively characterized: by weak tritium contents (between 2 and 3 UT) and a value of stable isotopes (-5,9<0,18<-5,5) corresponding to the appearance of cretaceous formation area; by the high tritium contents and enrichment relative to heavy isotope in the mineralized water of superficial formations. On the other hand, the isotope contents permit the set a rapid renewal of the cretaceous aquifer water due to quick circulation in the Karstic system
The irradiation behavior of Li{sub 2}TiO{sub 3} under a fusion reactor environment was simulated by simultaneous irradiation of Li{sub 2}TiO{sub 3} by the triple ion beams and the respective single ion beams of O{sup 2+}, He{sup +} and H{sup +}. The microstructural changes in Li{sub 2}TiO{sub 3} caused by the irradiation were measured by Raman spectroscopy and FT-IR photoacoustic spectroscopy. The results suggest that the formation of TiO{sub 2} due to displacements by irradiation occurs, and the irradiation defects generated by irradiation trap hydrogen and increase the amount of hydroxyl near the surface. Such phenomena are believed to significantly affect the chemical form of the released tritium and the tritium inventory in the breeding materials of a fusion reactor.
The irradiation behavior of Li_2TiO_3 under a fusion reactor environment was simulated by simultaneous irradiation of Li_2TiO_3 by the triple ion beams and the respective single ion beams of O"2"+, He"+ and H"+. The microstructural changes in Li_2TiO_3 caused by the irradiation were measured by Raman spectroscopy and FT-IR photoacoustic spectroscopy. The results suggest that the formation of TiO_2 due to displacements by irradiation occurs, and the irradiation defects generated by irradiation trap hydrogen and increase the amount of hydroxyl near the surface. Such phenomena are believed to significantly affect the chemical form of the released tritium and the tritium inventory in the breeding materials of a fusion reactor.
Lichens were collected in France in the surroundings of a military nuclear facility in Burgundy, near the la Hague reprocessing plant and in an area away from any direct source of contamination. Organically bound tritium (OBT) has been analysed on 18 samples and radiocarbon on 11. It appeared that on the most contaminated spots, the OBT activity in lichens was higher than the background by a factor of 1000 and was still a factor 10-100 at a distance of 20 km from the source. Radiocarbon from la Hague could be traced by lichens. The slow metabolism of lichens makes them suitable for the follow-up of {sup 3}H and {sup 14}C, which have been incorporated by photosynthesis.
In Tarapur Atomic Power Station unit-3 and 4, which is 540 MWe pressurized heavy water reactor, tritium is produced in primary heat transport system and moderator system. Tritium is a major contributor to the internal dose. Internal dose contributes about 30% of the collective dose. Internal dose monitoring and its control are important to control the collective dose. Estimation of internal dose is done by analysis of bioassay samples of radiation workers. In a month, about 7000 bioassay samples are analysed for the internal dose assessment during normal operation, and about 12000 during the biennial shut down of the reactor. To enhance the sample preparation and counting performance, minimize the entry errors and reduce the processing time, barcode based label generation system was developed for the internal dose monitoring. This paper discusses about the use of barcode system in the internal dose monitoring at TAPS 3 and 4. (author)
Human antibodies targeting prostate cancer cell surface epitopes may be useful for imaging and therapy. The objective of this study was to evaluate the tumor targeting of an internalizing human...Full Text Available
Computational prediction of microRNA targets remains a challenging problem. The existing rule-based, data-driven and expression profiling approaches to target prediction are mostly approached from the...Full Text Available
In order to identify novel high value antibacterial targets it is desirable to delineate whether the inactivation of the target enzyme will lead to bacterial death or stasis. This knowledge is particularly...Full Text Available
Computational fluid dynamics(CFD) code FLUENT was used to simulate the thermal hydraulic processes occurring in conceptual design of the accelerator-driven subcritical reactor(ADSR) liquid lead target. The purpose of the analysis is to investigate the thermal hydraulic characteristics of liquid lead as ADSR target material with various target geometries and injection locations of proton beam. In the calculation analysis, the local temperature of the liquid lead target rises to the boiling temperature very rapidly. When the proton beam is injected from the bottom of the target system, the duration time to reach the boiling temperature is longer and the temperature distribution is flatter than other cases.
Experimental and computational investigations were performed in order to better understand the mechanical response of rigid targets with various geometries to the detonation of shallow buried explosives. The motion of the targets was measured by use of high-speed digital video photography. This work involved flat targets, targets that were downwardly convex, and targets that were downwardly concave with explosive charges located at various positions beneath the targets. It was observed that, in general, angled hulls - whether downwardly concave or convex - tended to reduce the amount of momentum imparted to the center of mass of the targets. Computations were performed by use of an arbitrary Langrangian-Eulerian treatment in a nonlinear finite element code. A model based on quasi-static te...
In an effort to develop octahedral metal complexes as chemotherapeutic and diagnostic agents targeted to DNA, it is critical to optimize the properties of their cellular uptake. Appending d-octaarginine...Full Text Available
The design of the absorber blocks for internal and external dumping of the SPS proton beam is discussed. In addition, the external target stations for slow and fast extracted proton beams are described.
... L. Sutton. 2000. Is the aquatic weed hygrophila, Hygrophila polysperma (Polemoniales: Acanthaceae), a suitable target for classical biological ... ...
Nato SCI-12 on Camouflage Evaluation Workshop on Search and Target Acquisition The Netherlands, June 1999. Image Discrimination Models for Object Detection ...
By W. Wayne Scott. Langley Research Center. SUMMARY. Thin- and thick-target bremsstrahlung spectra are presented for electron energies up to 7.0 MeV. ...
The effective half-life based on urine bioassay results of Wolsung NPP's worker was calculated. The effective half-life for tritiated water vapour obtained was 5 {approx} 9 days. In comparison to 10 days reported for ICRP-30, it is lower than the corresponding half-life for Reference Man. Also, the half-life was calculated based on intake amount of daily water. According to this result, the metabolism was reviewed.
Possible causes of forest damage are discussed. Mapping of affected areas by various workers resulted in dissimilar pictures. Release of radioactive rare gases, aerosols, tritium and carbon-14 seems unlikely to have a significant influence on forest damage. Influence of radioactive fallout, ozone formation by high-voltage transmission lines and synergistic effects is also found to be negligible.
This paper reviews the effects of neutron irradiation on thermal and mechanical properties and bulk tritium retention of armour materials (beryllium, tungsten and carbon). For each material, the main properties affected by neutron irradiation are described and the specific tests of neutron irradiated armour materials under thermal shock and disruption conditions are summarized. Based on current knowledge, the expected thermal and structural performance of neutron irradiated armour materials in the ITER plasma facing components are analysed.
... This is true because a shorter residence time means that ground water moves 'faster.' Thus, contamination will get to the drinking well from the recharge area (point of entry) faster if the ground water is younger. However, it has been difficult to measure the exact age of young ground water. The conventional indicator has been tritium, a radioactive form of hydrogen, but its ...
An attempt is made to estimate the lithium reserve (the economically recoverable lithium) for the tritium breeding in D-T fusion reactors and other uses. Similar development patterns for fusion energy and fission energy are assumed to estimate the future lithium requirements. These requirements are grouped into three categories; the commercial uses, the lithium batteries for electric cars, and the fusion reactor uses. 5 refs.
The alkylation products formed by in vitro treatment of DNA with tritium-labeled 1,3-bis(2-chloroethyl)-1-nitrosourea (3H-BCNU) were identified and quantified. Twelve adducts were resolved...Full Text Available
Hydrology and hydrogeochemical are auxiliary techniques to valid conceptual hydrogeology an recharge models. Stable isotopes from water trace sources and path flow and Tritium indicates age. This paper is about the use of D 18, D2H y 3H to study the aquifer system on Bajo Cauca antioqueno.
It is planned to use the tritium dose model, DCART (Doses from Chronic Atmospheric Releases of Tritium), to reconstruct dose to the hypothetical maximally exposed individual from annual routine releases of tritiated water (HTO) and tritiated hydrogen gas (HT) from all Lawrence Livermore National Laboratory (LLNL) facilities and from the Sandia National (SNL) Laboratory's Tritium Research Laboratory over the last fifty years. DCART has been described in Part 1 of ''Historical Doses From Tritiated Water And Tritiated Hydrogen Gas Released To The Atmosphere from Lawrence Livermore National Laboratory (LLNL)'' (UCRL-TR-205083). This report (Part 2) summarizes information about annual routine releases of tritium from LLNL (and SNL) since 1953. Historical records were used to derive facility-specific annual data (e.g., source terms, dilution factors, ambient air ...
While tritium exposure to the site-workers in Wolsung NPP is upto about 40 % of the total personnel exposure, Korea Institute of Nuclear Safety has asked tritium removal facility, as one of the requirements for post reactor construction, after operation of four CANDU reactors in Wolsung site. For the purpose of essential removal of tritium from the heavy water system of the heavy water reactors, an experiment of Ar-N{sub 2} cryogenic distillation tower was carried out as a preliminary study for development of liquid-phase catalytic exchange - cryogenic hydrogen distillation process. The steady-state reached after 50 minutes under 90 K in the Ar-N{sub 2} distillation column (inner diameter 20 mm, height 500 mm) packed with Dixon ring ({phi} 3 mm x H 3 mm), and the ratios of Ar-concentration at the top and at the bottom measured by gas chromatography within {+-}1 % relative error was approximately 93 : 3. This value was ...
In a cold fusion method by electrolysis, a hydrogen occluding material mainly comprising vanadium is used as a material for a negative electrode, and lithium isotopes are incorporated in the material by more than 93%. That is, the ratio of lithium 7 ("7Li) isotope is increased to higher than the natural existent ratio, so that tritium ("3H) concentration in the hydrogen occluding material can be increased, to attain energy at high efficiency. (T.M.).
This Pollution Prevention Design Assessment (PPDA) provides data for cost-benefit analysis of the potential environmental impact of the APT, is an integral part of pollution prevention/waste minimization, and is required by DOE for any activity generating radioactive, hazardous, and mixed wastes. It will also better position the APT to meet future requirements, since it is anticipated that regulatory and other requirements will continue to become more restrictive and demanding.
The National Ignition Facility (NIF) is a proposed Department of Energy facility which will contribute to the resolution of important Defense Program and inertial fusion energy issues for energy production in the future. The NIF will consist of a laser system with 192 independent beamlets transported to a target chamber. The target chamber is a multi-purpose structure that provides the interface between the target and the laser optics. The chamber must be capable of achieving moderate vacuum levels in reasonable times; it must remain dimensionally stable within micron tolerances, provide support for the optics, diagnostics, and target positioner; it must minimize the debris from the x-ray and laser light environments; and it must be capable of supporting external neutron shielding. The chamber must also be fabricated from a low neutron activation material. The fusion reaction in the ...
We proposed a solid and a mercury target concepts through the preliminary conceptual design. To feasible these concepts, analysis and experimental works are being carried out. This paper introduces an outline of present status of target R and D such as heat transfer augmentation experiments for the solid target, mercury flow tests with a loop of maximum flow rate of 15L/min, flow pattern measurements for a cold source moderator etc. as well as preliminary conceptual design works. (author)
In the CERN approach to the design of a neutrino factory, the repetition frequency of the proton beam is high enough to consider stationary solid targets as a viable solution for multi-MW beams. The target consists of high density tantalum spheres of 2 mm diameter which can efficiently be cooled by passing a high mass flow He-gas stream through the voids between the Ta-granules. Very small thermal shocks and stresses will arise in this fine grained structure due to the relatively long burst of 3.3 ms from the SPL-proton linac. In a quadruple target system where each target receives only one quarter of the total beam power of 4 MW, conservative temperature levels and adequate lifetimes of the target are estimated in its very high radiation environment. A conceptual design of the integration of the target into the magnetic horn-pion-collector is presented.
Two children with cutaneous lymphoma and leukemia who were treated with total skin electron beam therapy (TSEB) are described here. Patient 1. A 7-year-old boy was admitted because of a mass over the bilateral parotis and anemia. The white blood cell count on admission was 5,000/ul. Bone marrow examination revealed 70 per cent monoblasts (M5a type by FAB classification). Complete remission was obtained following the regimen of daunomycin, cytosine arabinoside, 6-mercaptopurine and prednisolone. He was again admitted because of a skin nodule on the left thigh 19 months after initial diagnosis. A biopsy of the skin nodule demonstrated monoblastic infiltration. He received 20 Grays (Gy) to the left thigh and this led to resolution of the skin nodule. At that time, other skin nodules appeared on the right upper and lower extremities. He was treated with TSEB. Daily doses of 1 Gy were given twice a week with a 4 MeV electron beam and a total dose of 10 Gy was ...
The authors have shown previously that the domain recognizing receptors on activated human platelets is located on the human fibrinogen {gamma} chain between residues 400 and 411. To study the correlation between the structure of this segment of the {gamma} chain and its reactivity toward receptors on ADP-activated human platelets, they designed a series of analogues containing replacements at 9 out of 12 positions. A double substitution of the normal His{sup 400}-His{sup 401} sequence by Ala-Ala reduced the inhibitory potency of the dodecapeptide 3-fold. When Lys{sup 406} was replaced by Arg, the inhibitory potency of the dodecapeptide decreased 15 times. On the other hand, substitution of Ala{sup 408} with Arg increased the inhibitory potency of the dodecapeptide 6-fold. A drastic decrease in the reactivity of the dodecapeptide toward platelet receptors was observed when Val{sup 411} was replaced by leucine or cysteine or tyrosine. A 3-fold decrease in reactivity was noted when ...
Anti-carcinoembryonic antigen monclonal antibody (MAb) CEA 102 was produced by immunization with purified CEA and the specific accumulation of radiolabeled CEA 102 in colorectal cancers was investigated by autoradiography of sugical specimens using Fuji Computed Radiography (FCR). Five patients with colorectal cancer were injected intravenously with "1"3"1I-labeled intact CEA 102 or its F(ab')_2. Primary tumor and liver metastases were successfully detected by external scanning with a gamma camera in 4 cases. Autoradiographic study of the surgical specimens using FCR showed predominant localization of "1"3"1I-labeled CEA 102 in primary tumors and liver metastases in all cases. Even a small liver metastasis (0.5 cm) was clearly visualized in the autoradiogram by FCR. The pixel distribution curves of the density of the respective tissues in the autoradiograms by FCR showed the heterogeneity of the distribution of administreted radiolabeled MAb in individual tumors, ...
The fusion materials program has little irradiation effects data at temperatures from 100 to 350 degree C. Near-term machines such as the International Thermonuclear Engineering Reactor (ITER) will expose materials to neutron doses of 38 to 50 dpa at 150 degree C or less. The data base for structural materials must be extended into this range. Also, lower temperatures are needed to investigate the lower bound for tritium release from solid breeder materials. A low temperature test vehicle is proposed for the Fast Flux Test Facility (FFTF), which will provide test temperatures of 100 to 350 degree C. An 8.5-cm dia. by 100-cm test volume will be instrumented to collect temperature data and provide feedback for control. The spectrum and flux will provide accelerated damage accumulation for structural materials testing and the best available approximation of fusion reactor conditions for solid breeder materials testing. Breeder samples can be equipped with sweep gas ...
Due to severe drought conditions in Pakistan over the past several years, most of the areas are facing extinction of its potable water reserves and inadequate replenishment of groundwater aquifers. Due to over exploitation, the groundwater flow dynamics is changing and water quality is degrading due to induced infiltration from polluted surface sources. Isotope hydrology is relatively a new discipline having great potential for studying various water-related problems. RIAD, PINSTECH has established analytical facilities for commonly used environmental isotopes and applied to investigate various hydrological problems. This paper briefly describes practical examples on recharge mechanism and dating of groundwater in Lahore and Ziarat areas using isotopes like deuterium (/sup 2/H), Oxygen-18 (/sup 18/O), Tritium (/sup 3/H) and CFCs in water. In Lahore, the areas having different contribution of the river Ravi in groundwater recharge have been marked and on the basis ...
The FFTF Standby Plan, Revision 0, provides changes to the major elements and project baselines to maintain the FFTF plant in a standby condition and to continue washing sodium from irradiated reactor fuel. The Plan is consistent with the Memorandum of Decision approved by the Secretary of Energy on January 17, 1997, which directed that FFTF be maintained in a standby condition to permit the Department to make a decision on whether the facility should play a future role in the Department of Energy`s dual track tritium production strategy. This decision would be made in parallel with the intended December 1998 decision on the selection of the primary, long- term source of tritium. This also allows the Department to review the economic and technical feasibility of using the FFTF to produce isotopes for the medical community. Formal direction has been received from DOE-RL and Fluor 2020 Daniel Hanford to implement the FFTF standby decision. The ...
To estimate of the dispersion trend of 3H and 14C discharged from the Wolsung Nuclear Power Plants, the present level of 3H and 14C in environmental samples in the vicinity of the Wolsong site was studied. Tree-ring cellulose analyses were carried out for retrospective evaluation of 3H and 14C in the environment around the Wolsong Nuclear Power Plants. 3H released from the Wolsong Nuclear Power Plants has affected an area up to a 25-km radius from the site, while almost all 14C was deposited within a 2-km radius, reaching to a natural level over 2 km. Organically bound tritium concentrations in tree rings were strongly correlated with the gaseous tritium discharge rate, while delta14C (excess) in tree rings ranged from 204 per thousand to 460 per thousand, which did not significantly vary with year. PMID:10832930
The newly developed techniques by the Hot Laboratory (JMTR HL) have provided for us the key information on behavior of specimens due to mechanical / physical / chemical / synergistic effects of radiation, stress and water for fission and fusion reactor environment. These techniques are focused on several topics as follows; (1) miniaturized specimen test for the development of fusion reactor materials, (2) slow strain rate tensile testing (SSRT) and crack propagation measuring tests for the study of Irradiation Assisted Stress Corrosion Cracking (IASCC) of core internals of LWR, (3) handling technique on specimens including tritium for the research and development of tritium breeders and neutron multiplier as fusion blanket materials, (4) joining method using the Tungsten Inert Gas (TIG) welding technique for re-assembling of capsule and re-fabrication of specimen and (5) nondestructive evaluation using ultrasonic wave and infrared thermography ...
ESH-19 personnel collected soil and single-stage water samples around the perimeter of Area G at Los Alamos National Laboratory (LANL) during FY 95 to characterize possible radionuclide movement out of Area G through surface water and entrained sediment runoff. Soil samples were analyzed for tritium, total uranium, isotopic plutonium, americium-241, and cesium-137. The single-stage water samples were analyzed for tritium and plutonium isotopes. All radiochemical data was compared with analogous samples collected during FY 93 and 94 and reported in LA-12986 and LA-13165-PR. Six surface soils were also submitted for metal analyses. These data were included with similar data generated for soil samples collected during FY 94 and compared with metals in background samples collected at the Area G expansion area.
Lithium carbonate pellets are frequently used for estimation of tritium production rate in irradiated samples in fusion blanket neutronics experiment and the activity is measured by liquid scintillation counting technique. In this measurement, it is essential to solve the lithium carbonate pellet as much as possible and to mix the pellet solution into scintillation cocktail homogeneously at stable condition. For this purpose, a novel binary-acid method has been developed to solve lithium carbonate and to mix the pellet solution into scintillation cocktail. High solubility is attained by adopting two acids, HNO_3 and CH_3COOH, and a good compatibility of the pellet solution with scintillator is obtained by emulsion cocktail resulting in high counting efficiency. Defining a product of dissolved mass and counting efficiency as a Figure of Merit (FOM), the present method has higher FOM value than the conventional method and is extremely simple in a sample preparation ...
The thermonuclear reactivity of deuterium(D) - tritium(T) fusion plasma with spin-polarized fuel has been studied. Two mechanisms of depolarization, collisions and waves, in the high temperature fusion plasma have been considered. The binary collisions have been found not to change the nuclear spin states. The waves with a frequency of a few GHz, however, changes the spin states appreciably, when {delta}B/B{sub 0} (the ratio of the amplitude of the fluctuating magnetic field to the external field) becomes larger than 10{sup -5}. (author)
A prototype hydride storage bed, using LaNi{sub 4.25}Al{sub 0.75} as the storage material, was fitted with strain gages to measure strains occurring in the stainless steel bed vessel caused by expansion of the storage powder upon uptake of hydrogen. The strain remained low in the bed as hydrogen was added, up to a bed loading of about 0.5 hydrogen to metal atom ratio (H/M). The strain then increased with increasing hydrogen loading ({approximately} 0.8 H/M). Different locations exhibited greatly different levels of maximum strain. In no case was the design stress of the vessel exceeded.
Within the APROS simulation environment we have built a thermo-hydraulic model of a conceptual fusion power plant which is water cooled and uses lithium-lead for tritium breeding. For the safety assessment of this design we have studied an accident sequence which starts from a loss or coolant flow then leads to first wall breach and pressurisation of the vacuum vessel. Simulations have revealed strong pressure transients which can be alleviated by design changes. One goal is to verify the adequacy of the containment design: it remains intact at least 14 h without any mitigating efforts. Estimates for radioactive releases are obtained. (author)
The Joint European Torus (JET) fusion machine is the only device capable of operation with tritium (as fuel) and Be (as plasma facing component), what makes it best suited to study ITER relevant issues. A large variety of activities are performed within the JET Fusion Technology Task Force. In this paper, some topics such as erosion/deposition and material transport, flakes characterization and detritiation techniques are highlighted. Recent results obtained using a pumping cryo-panel and on plasma facing component characterisation are given. Finally, issues that will be addressed in the forthcoming JET work-programme are presented, such as a beryllium main wall for JET and in-situ laser detritiation. (authors)
In this paper the diffusion of tritiated water vapor into concrete walls is studied to evaluate tritiated water retention capacity of a fusion reactor concrete building. Using a model of the tritiated water diffusion determined form experimental results, depth profiles of tritiated water in concrete are calculated in the case of being exposed to air containing tritiated water vapor during the normal operational condition of a fusion reactor. A 0.5-m-thick concrete is sufficient for reactor hall walls from a viewpoint of the tritium containment.
In this paper the diffusion of tritiated water vapor into concrete walls is studied to evaluate tritiated water retention capacity of a fusion reactor concrete building. Using a model of the tritiated water diffusion determined form experimental results, depth profiles of tritiated water in concrete are calculated in the case of being exposed to air containing tritiated water vapor during the normal operational condition of a fusion reactor. A 0.5-m-thick concrete is sufficient for reactor hall walls from a viewpoint of the tritium containment.
The dual-media approach to contaminant transport modeling has emerged over the years as a clear improvement over the conventional Fickian advection-dispersion, or single-medium model, in an increasing number of settings. Recent application to the MADE-2 tracer test at Columbus Air Force Base has extended interest to field-scale plume migration in unconsolidated sediments. Subsequent application to tritium migration from the SRS F- and H-area seepage basins within this study also demonstrated improved transport predictions.
This paper describes the results of a model intercomparision exercise for predicting tritium transport through foodchains. Modellers were asked to assume that farmland was exposed for one hour to an average concentration in air of 10{sup 4} MBq tritium m{sup -3}. They were given the initial soil moisture content and 30 days of hourly averaged historical weather and asked to predict HTO and OBT concentrations in foods at selected times up to 30 days later when crops were assumed to be harvested. Two fumigations were postulated, one at 10.00 h (i.e., in day-light), and the other at 24.00 h (i.e., in darkness).Predicted environmental media concentrations after the daytime exposure agreed within an order of magnitude in most cases. Important sources of differences were variations in choices of numerical values for transport parameters. The different depths of soil layers used in the models appeared to make important contributions to differences in ...
PurposeWe conducted a comparative study of Clinical Target Volume (CTV) definition of pelvic lymph nodes by multiple GU radiation oncologists looking at the levels...Full Text Available
To capitalize on the response of tumor cells to ionizing radiation, we developed a controlled-release nanoparticle drug delivery system using a targeting peptide that recognizes a radiation-induced...Full Text Available
The role of IGF-I in the negative regulation of GH expression and release is demonstrated by in vitro and in vivo models; however, the targets and mechanisms of IGF-I...Full Text Available
The technology of gene targeting through homologous recombination has been extremely useful for elucidating gene functions in mice. The application of this technology was thought impossible in the large...Full Text Available
The goal of ultrasonic molecular imaging is the detection of targeted contrast agents bound to receptors on endothelial cells. We propose imaging methods that can distinguish adherent microbubbles...Full Text Available
... detected (and reported) as a by-product of MRM screening (MS/MS) targeted by Law or Rule ... detected (and reported) as a by-product of MRM screening (MS/MS) targeted by Law or Rule ...
The phenomenon of antibiotic resistance has created a need for the development of novel antibiotic classes with non-classical cellular targets. Unfortunately, target-based drug discovery against...Full Text Available
Many genetic processes depend on proteins interacting with specific sequences on DNA. Despite the large excess of nonspecific DNA in the cell, proteins can locate their targets rapidly. After initial...Full Text Available
Peroxisomes, glyoxysomes, glycosomes, and hydrogenosomes have each been classified as microbodies, i.e., subcellular organelles with an electron-dense matrix that is bound by a single membrane. We investigated...Full Text Available
Considering accessibility of the 3′UTR is believed to increase the precision of microRNA target predictions. We show that, contrary to common belief, ranking by the hybridization energy or by...Full Text Available
Histone Arg methylation and Lys acetylation have been found to cooperatively regulate the expression of p53 target genes. Peptidylarginine deiminase 4 (PAD4) is an enzyme that citrullinates...Full Text Available
Operant conditioning techniques were applied to the study of how target fixations are controlled by the probability of signal occurrence. In a standard vigilance setting, gaze at three illuminable...Full Text Available
Cytokinesis in animal and fungal cells utilizes a contractile actomyosin ring (AMR). However, how myosin II is targeted to the division site and promotes AMR assembly, and how the AMR coordinates with...Full Text Available
Purposes1. To determine the optimal pelvic nodal clinical target volume for post-operative treatment of endometrial cancer. 2. To compare the DVH of different treatment planning...Full Text Available
... they assisted in the 2000 attack on the USS Cole? ... List the types of targets that ETA has attacked. ... was at least partially responsible for the attack. ...
... Tanzania, and the attack on the USS COLE. ... vis another has no bearing on the legality of the attack. If the person attacked is a combatant, the use of ...
The production of polarized negative ion beams by collisional pumping is described. Collisional pumping utilizes repeated charge changing collisions in a thick electron-spin-polarized gas or vapor target to form a polarized fast atom beam. The polarized fast atom beam is then partially converted into a polarized negative ion beam in a vapor target. Analysis is presented for a hydrogen beam passing through either a thick polarized H atom target or a thick polarized alkali target. Large polarizations and large currents may be possible.
The production of polarized negative ion beams by ''collisional pumping'' is described. Collisional pumping utilizes repeated charge changing collisions in a thick electron-spin-polarized gas or vapor target to form a polarized fast atom beam. The polarized fast atom beam is then partially converted into a polarized negative ion beam in a vapor target. Analysis is presented for a hydrogen beam passing through either a thick polarized H atom target or a thick polarized alkali target. Large polarizations and large currents may be possible.
While there is growing interest in Real Time Pricing as a competitive tool, its adoption to date has been constrained by wariness on the part of many utilities and many of their customers. That wariness is not misplaced, for Real Time Pricing is not for everyone. In order for both utilities and their customers to benefit, the pricing system must be properly tailored for, and offered to, the appropriate audience. This paper discusses needs for identifying targets, implications of targeting of Real Time Pricing to various types of customers, and implications for design and marketing of such pricing systems. Examples from utility experiences are provided, and recommendations are offered for development of improved targeting of Real Time Pricing.
This paper present the results of a series of calculations made to determine the "2"3"8Pu production potential of several advanced target assembly designs in the Fast Flux Test Facility (FFTF). These calculations show that by using advanced target designs the intimately mix the "2"3"7Np target material with an yttrium hydride moderator, the FFTF has the potential of producing up to 30 kg of high-quality "2"3"8Pu per year.
We apply the framework developed in Target space duality I: general theory. We show that both nonabelian duality and Poisson-Lie duality are examples of the general theory. We propose how the formalism leads to a systematic study of duality by studying few scenarios that lead to open questions in the theory of Lie algebras. We present evidence that there are probably new examples of irreducible target space duality.
The gastrin releasing peptide (GRP) receptor is becoming an increasingly attractive target for development of new radiolabeled peptides with diagnostic and therapeutic potential. The attractiveness of the GRP receptor as a target is based upon the functional expression of GRP receptors in several tumors of neuroendocrine origin including prostate, breast, and small cell lung cancer. This concise review outlines some of the efforts currently underway to develop new GRP receptor specific radiopharmaceuticals by employing a variety of radiometal chelation systems.
This paper illustrates how the techniques developed by the authors for capital cost targeting of mass exchange networks can be applied to determination of capital investment targets for reduction in effluent for existing systems involving mass exchange. The results is an impact diagram which shows the relationship between effluent reduction and capital investment, indicating a region of limiting return on investment as well as the maximum possible reduction in effluent. (au)
In order to facilitate observations of low energy nuclear reactions, a new type recoil mass-separator together with a new gas-jet target system is being developed at the tandem accelerator facility in Kyushu University. The expected mass-resolving power of the separator is 220 for a solid angle of 10 msr and the practical thickness of the gas-jet target will exceed 0.1 atm#centre dot#cm for the light elements of H and He. (author).
A portable fiber optic detector that senses the presence of specific target chemicals by electrostatically attracting the target chemical to an aromatic compound coating on an optical fiber. Attaching the target chemical to the coated fiber reduces the fluorescence so that a photon sensing detector records the reduced light level and activates an appropriate alarm or indicator.
A 16 l liquid parahydrogen target has been developed for a measurement of the parity-violating {gamma}-asymmetry in the capture of polarized cold neutrons on protons in the {rvec n} + p {yields} d + {gamma} reaction by the NPDGamma collaboration. The target system was carefully designed to meet the stringent requirements on systematic effects for the experiment and also to satisfy hydrogen safety requirements. The target was designed to preserve the neutron polarization during neutron scattering on liquid hydrogen (LH{sub 2}), optimize the statistical sensitivity to the {rvec n} + p {yields} d + {gamma} reaction, minimize backgrounds coming from neutron interaction with the beam windows of the target cryostat, minimize LH{sub 2} density fluctuations which can introduce extra noise in the gamma asymmetry signal, and control systematic effects. The target incorporates two mechanical ...
...2010-10-01 2010-10-01 false Energy Policy Act target group certification...Acquisition Regulations System DEPARTMENT OF ENERGY CLAUSES AND FORMS SOLICITATION...Provisions and Clauses 952.226-73 Energy Policy Act target group...
Target materials for inertial fusion energy (IFE) power plant designs might be selected for a wide variety of reasons including wall absorption of driver energy, material opacity, cost and ease of fabrication. While each of these issues are of great importance, target materials should also be selected based upon their safety and environmental (S and E) characteristics. The present work focuses on the recycling, waste management and accident dose characteristics of potential target materials. If target materials are recycled so that the quantity is small, isotopic separation may be economically viable. Therefore, calculations have been completed for all stable isotopes for all elements from lithium to polonium. The results of these calculations are used to identify specific isotopes and elements that are most likely to be offensive as well as those most likely to be acceptable in terms of their S and E ...
Certain allelochemicals of the marine dinoflagellate Alexandrium tamarense cause lysis of a broad spectrum of target protist cells but the lytic mechanism is poorly defined. We first hypothesized that membrane sterols serve as molecular targets of these lytic compounds, and that differences in sterol composition among donor and target cells may cause insensitivity of Alexandrium and sensitivity of targets to lytic compounds. We investigated Ca^2^+ influx after application of lytic fractions to a model cell line PC12 derived from a pheochromocytoma of the rat adrenal medulla to establish how the lytic compounds affect ion flux associated with lysis of target membranes. The lytic compounds increased permeability of the cell membrane for Ca^2^+ ions even during blockade of Ca^2^+ channels wit...
A simple electromagnetic transport system was constructed to identify very rare positrons produced in a powerful laser beam interaction with a target. Testing experiments were carried out with CO[sub 2]-laser (10[sup 12] W/cm[sup 2]) beam pulses ([tau] = 50 ns, f = 0.01 Hz) focused on the copper target, as well as with a 96 MeV alpha-particle beam irradiated carbon target. The results showed that the developed system could be effectively used for positron identification and evaluation of their energy by means of a time-of-flight method. The computerized system to deal with this problem, together with others related to the power laser beam interaction with targets, has been constructed. (orig.).
The modeling methods used to compute the neutron-induced activation of target and near-target materials in the NIF facility are presented. A detailed space and energy description of the neutron environment in the different materials is provided. A new capability has been developed to treat in a general way the activation of debris produced in an operational regime of yield and no-yield experiments. First calculations are addressed to analyze the activity of the debris into the target chamber. The contribution of the different components to activity, interior dose rates, and waste disposal rating (WDR) is determined. The importance of the activation coming from primary irradiation in the target, and from secondary irradiation in debris deposited onto the first wall is assessed. Finally, waste hazards of the activated debris when removed out of the chamber and stored are analyzed. (authors)
Using static Michelson interferometer to get the spectrum information of measurement targets for spectrum identification, under the condition that the interference length is constant, the system can be optimized by BP neural network algorithm for the mixed spectral separation process. Thereby it can realize improving the recognition probability of camouflage target. Collecting the spectrum information in field of view (FOV) by the interferometer and linear array CCD detector, composing the set of mixed spectrum data, with known absorption spectrum of the material as a hidden layer of rules, it used BP neural network to separate the mixed spectrum data. Experiment with different distances, different combinations of mixed background spectrum as the initial data, using steel target (size: 1.5 m x 1.5 m) made of four kinds, the recognition probability of non-camouflage target is about 90% by BP neural ...
In the Fourth Dutch National Environmental Outlook (NMP, abbreviated in Dutch) of the National Institute of Public Health and the Environment (VROM), published in July 1997, possible future developments in the traffic and transport sector in the Netherlands are described for the period 1995-2020 and also evaluates present Dutch policies. NMP-4 also offers possible solutions for expected environmental problems. This report serves as a background document for the traffic and transport sector. With a view to present Dutch policies, the main conclusions drawn from the Outlook are that: (1) the policy targets for car and lorry use for 2010 will not be met, (2) the target for CO2 emissions from road transport for 2010 will not be met, (3) the NOx emission target for 2010 will be met for cars, but not for trucks, (4) the VOC emission target for 2010 will be met for cars, but not for trucks, and (5) the noise ...
The design of solid breeder blankets is strongly affected by the low values of thermal conductivity and density of ceramic breeder pebble beds. A significant rise of both quantities would enhance the thermal performance and lead to an increased tritium breeding ratio. In order to improve these quantities pretreated lithium orthosilicate pebble material was dry pressed and subsequently sintered. The thermal conductivity of cylindrical pellets was determined by the heat pulse method using a laser flash device. A pebble bed characteristic sample was also investigated in order to check the measurement accuracy in comparison with previous results. Furthermore, two samples of low density cellular ceramics were also prepared by infiltration of polymer foams with a ceramic slurry. The thermal cond...
Test Blanket Modules (TBM) will be tested in ITER to verify the capability of tritium breeding and recovery and the extraction of thermal energy suitable for the production of electricity. A Helium Cooled Solid Breeder (HCSB) TBM has been developed in Korea to accomplish these goals. Reduced Activation Ferritic/Martensitic (RAFM) steel has been chosen as the primary candidate structural material for Korean TBM. Due to the complexity of the First wall (FW) and Side wall (SW), it is necessary to develop various joining technologies, such as Hot Isostatic Pressing (HIP), Electron Beam Welding (EBW) and Tungsten Inert Gas (TIG) welding, for the successful fabrication of TBM. In this study, the mechanical properties of TIG welded RAFM steel were investigated. Various mechanical tests of TIG-welded RAFM steel were performed to obtain the optimized TIG welding process for RAFM steel
We find dosage of gamma emitters radionuclides of samples collected in the environment of the Chinon nuclear power plant for 2002 and 2003, these results are presented in two tables: concentrations in gamma emitter radionuclides of samples collected in the terrestrial environment (soils) and aquatic environment (sediments) of the site of Chinon in june 2002 in the frame of the annual surveillance, the second table concerns the concentrations in gamma emitter radionuclides of samples collected in the terrestrial environment (soils and lichens) of the site of Chinon in may 2003 in the frame of the annual surveillance. We find also the dosage of free tritium in the water of the Loire river for 2002 and 2003, upstream and downstream to the power plant of Chinon. (N.C.)
The prospects for the low-aspect-ratio (A) tokamak to fulfill the requirements of viable fusion power plants are considered relative to the present status in data and modeling. Desirable physics and design features for an attractive Blanket Test Facility and power reactors are estimated for low-A tokamaks based on calculations improved with the latest data from small pioneering experiments. While these experiments have confirmed some of the recent predictions for low-A, they also identify the remaining issues that require verification before reliable projections can be made for these deuterium-tritium applications. The results show that the low-A regime of small size, modest field, and high current offers a path complementary to the standard and high A tokamaks in developing the full potential of fusion power.
The PERMCAT is a membrane reactor proposed for processing fusion reactor plasma exhaust gas: tritium removal is obtained by isotopic swamping operating in counter-current mode. In this work, a membrane reactor using a permeator tube of length about 500 mm produced via diffusion welding of Pd-Ag thin foils is described. An appropriate mechanical design of the membrane module has been developed in order to avoid any significant compressive and bending stresses on the very long and thin wall permeator tube: two expanded bellows have been applied to the Pd-Ag tube, so that it has been pre-tensioned before operating. The elongation of the metal permeator under hydrogenation has been theoretically estimated and experimentally verified for properly designing the membrane reactor.
The aim of this thesis is the design of a faults diagnosis-aiding system in a nuclear facility of the Cea. Actually the existing system allows the optimization of the production processes in regular operating conditions. Meanwhile during accidental events, the alarms, managed by threshold, are bringing no relevant information. To increase the reliability and the safety, the human operator needs a faults diagnosis-aiding system. The developed system, SECAPI, combines problem solving techniques and automatic learning techniques, that allow the diagnosis and the the simulation of various faults happening on nuclear facilities. Its reasoning principle uses case-based and rules-based techniques. SECAPI owns a learning module which reads out knowledge connected with faults. It can then simulate various faults, using the inductive logical computing. SECAPI has been applied on a radioactive tritium treatment operating channel, at the Cea with good results. (A.L.B.)
Summaries are included of research contracts which expired prior to Dec. 31, 1960. The contracts were concerned with investigations of: electrophysiological responses of biological systems in nerve cells to irradiation with small doses of ionizing radiations; the mode of the protective action of certain sulfhydryl compounds against radiation effects on the synthesis of deoxyribonucleic acid, using tritium-labeled thymidine; development of a bubble chamber method of monitoring and dosimetry for Low fast neutron fluxes; effects of incorporated radioisotopes on the stability of genetic materials; interrelation of root and leaf absorption of radioisotopes in herbaceous plants; uptake of radioactive wastes by lowland rice from soils contaminated by irrigation water, and decontamination of the rice; and comparison between mutation rates induced by acute and chronic gamma irradiations. (B.O.G.)
Brookhaven National Laboratory is involved in a conceptual design study of a commercial nuclear power system which utilizes high-temperature electrolysis to produce synthetic fuels. The system is called HYFIRE. It includes a tokamak fusion power reactor supplying electrical and thermal energy to an array of electrolytes. The electrolytes produce hydrogen which can be used either directly as a fuel or in the production of hydrocarbons. The purpose of the study is to provide a mechanism for DOE to further assess the commercial potential of fusion using a tokamak reactor to produce synthetic fuel. The HYFIRE design is based on the tokamak commercial power reactor, STARFIRE. STARFIRE uses the deuterium/tritium/lithium fuel cycle. The HYFIRE study assumes the plasma shape and characteristics of STARFIRE study but uses a different blanket design. This study is particularly interested in the possibility of using the STARFIRE tokamak in the production of synthetic fuels.
The nuclear complex in Tarapur, Maharashtra is a multi facility nuclear site comprising of power reactors and research facilities. Each facility has independent liquid effluent discharge line to Arabian Sea. Experimental studies were conducted to evaluate dilution factors in the aquatic environment using liquid effluent releases as tracer from one of the facilities. 3H and 137Cs radioisotopes present in the routine releases were used as simulated tracer nuclides. The dilution factors(D.F) observed for tritium were in the range of 20-20000 in a distance range of 10 m to 1500 m respectively and for 137Cs the D.F. were in the range of 50 to 900 over a distance range of 10-200 m. The paper describes the analytical methodology and sampling scenarios and the results of dilution factors obtained for Tarapur aquatic environment. (author)
Tests on a sample of trench water from the Maxey Flats burial ground effectively demonstrated the new Reverse Osmosis Pilot Plant. The effluent from the 50% salt-rejection membrane was decontaminated well enough with the exception of tritium to be discharged to the environment. The performance of the 97% salt-rejection membrane was superior to that of the 50% membrane. A breakthrough and capacity experiment was conducted with Durasil 10 on a simulated Three Mile Island solution. The maximum decontamination factor was extrapolated to be 10/sup 6/, which would reduce the cesium level of TMI water to below the discard limit. Capacity (1/DF = 0.5) was reached at 1260 column volumes. Several adsorbents were tested in the engineering columns for decontamination of cesium-bearing solutions. Under the conditions of the experiment, these adsorbents were ineffective in removing cesium from the solution.
It is planned to bulk-heat a unit cell of a fusion reactor solid-breeder blanket in a fission reactor to study thermo-mechanical and thermal-hydraulic properties of fusion blankets. This study investigates the neutronic feasibility of using the Power Burst Facility (PBF) for this purpose. Heating rates were calculated for a Li/sub 2/O experiment placed in the PBF test space. The ANISN code and a 56-group coupled neutron-gamma library based on FLUNG and VITAMIN C were used to compute the heating rates. The results show that an average heating rate level of 1-3 W/cc can be produced in PBF with a local power profile that should be typical of a fusion blanket unit cell.
ARIES-AT is a 1000MWe conceptual fusion power plant design with a very low projected cost of electricity. The design contains many innovative features to improve both the physics and engineering performance of the system. From the safety and environmental perspective, there is greater depth to the overall analysis than in past ARIES studies. For ARIES-AT, the overall spectrum of off-normal events to be examined has been broadened. They include conventional loss of coolant and loss of flow events, an ex-vessel loss of coolant, and in-vessel off-normal events that mobilize in-vessel inventories (e.g., tritium and tokamak dust) and bypass primary confinement such as a loss of vacuum and an in-vessel loss of coolant with bypass. This broader examination of accidents improves the robustness of ...
Purpose: Various published reports involving intensity-modulated radiotherapy (IMRT) plans developed using automated optimization (inverse planning) have demonstrated highly conformal plans. These reported conformal IMRT plans involve significant target dose inhomogeneity, including both overdosage and underdosage within the target volume. In this study, we demonstrate the development of optimized beamlet IMRT plans that satisfy rigorous dose homogeneity requirements for all target volumes (e.g., #+-#5%), while also sparing the parotids and other normal structures. Methods and Materials: The treatment plans of 15 patients with oropharyngeal cancer who were previously treated with forward-planned multisegmental IMRT were planned again using an automated optimization system developed in-house. The optimization system allows for variable sized beamlets computed using a three-dimensional convolution/superposition dose ...
The production methods for seven radioisotopes, Ga-67, Sr-85, Pd-103, In-111, Tu-167, Hg-197 and Pb-203, by using a classical 1.5m cyclotron in the Institute of Physics and Power Engineering, Obninsk, USSR, are described. At present, more than 50 cyclotrons in different countries are used for the production of radioisotopes applied to medicine. Radioisotopes are produced with the cyclotron in the I.Ph.P.E. in the form of irradiated targets, which are delivered to Moscow radiopharmaceutical factory, where radiopharmaceuticals are produced on the base of these targets. The cyclotron is operated in two regimes providing the acceleration of protons, deuterons and alpha -particles. Two types of target assemblies are used for irradiation, the one is intended for the internal beam, and the other is for the external beam. The reactions used for the production of seven radioisotopes described above, the types of ...
The production methods for seven radioisotopes, Ga-67, Sr-85, Pd-103, In-111, Tm-167, Hg-197 and Pb-203, by using a classical 1.5m cyclotron in the Institute of Physics and Power Engineering, Obninsk, USSR, are described. At present, more than 50 cyclotrons in different countries are used for the production of radioisotopes applied to medicine. Radioisotopes are produced with the cyclotron in the I.Ph.P.E. in the form of irradiated targets, which are delivered to Moscow radiopharmaceutical factory, where radiopharmaceuticals are produced on the base of these targets. The cyclotron is operated in two regimes providing the acceleration of protons, deuterons and alpha -particles. Two types of target assemblies are used for irradiation, the one is intended for the internal beam, and the other is for the external beam. The reactions used for the production of seven radioisotopes described above, the types of ...
This paper proposes a new pattern recognition system employing optical joint transform correlation (JTC) technique which offers a great number of advantages over similar digital techniques, including very fast operation, simple architecture and capability of updating the reference image in real time. The proposed JTC technique incorporates a synthetic discriminant function (SDF) of the target image estimated from different training images to make the pattern recognition performance invariant to noise and distortion. It then involves four different phase-shifted versions of the same target SDF reference image, which are individually joint transform correlated with the given input scene. When the correlation signals are combined, it produces a single cross-correlation peak corresponding to each potential target present in the given input scene. The proposed technique also includes a fringe-adjusted filter to generate a ...
Laser optical pumping can be used to produce polarized alkali atom beams or polarized alkali vapor targets. Polarized alkali atom beams can be converted into polarized alkali ion beams, and polarized alkali vapor targets can be used to produce polarized H/sup -/ or /sup 3/He/sup -/ ion beams. In this paper the authors discuss how the polarized alkali atom beams and polarized alkali vapor targets are used to produce polarized ion beams with emphasis on the production of polarized negative ion beams.
The HARP experiment at CERN is performing extensive measurements of hadron production cross sections and secondary particle yields, in the momentum range 1.5-15 GeV/c, over the full solid angle and using a large set of cryogenic and solid targets. First measurements of hadron production cross-sections in the forward region are reported using an aluminium target 5% of an interaction length thick and a proton beam of 12.9 GeV/c. A preliminary analysis in the large angle region of elastic scattering events produced with the cryogenic hydrogen target at 3 GeV/c beam momentum is also presented.
Carrier-free radionuclides of tungsten and tantalum, "1"7"6","1"7"7W and "1"7"6","1"7"7Ta have been produced by heavy ion activation of holmium target with 97 MeV "1"6O"5"+ beam. Radiochemical separation scheme has been developed to isolate tungsten and tantalum radionuclides from the holmium target matrix. (author)
Carrier-free radioisotopes of tungsten, "1"7"6","1"7"7W, and their corresponding daughter radionuclides "1"7"6","1"7"7Ta, have been produced in holmium target by heavy ion activation with "1"6O"5"+ beam. An attempt has been made to separate these carrier-free radionuclides from bulk holmium target through LLX using cation exchanger HDEHP. (author)
A simple highly efficient procedure has been developed for recovery of thallium radioisotopes from lead and bismuth targets irradiated by 1-GeV protons. The procedure is based on the use of extraction chromatography. The cross-sections have been determined for formation of {sup 200}Pb, {sup 201}Pb, {sup 202m}Pb, and {sup 203}Pb radioisotopes in targets from lead with natural isotopic composition, irradiated by 1-GeV protons.
A simple highly efficient procedure has been developed for recovery of thallium radioisotopes from lead and bismuth targets irradiated by 1-GeV protons. The procedure is based on the use of extraction chromatography. The cross-sections have been determined for formation of "2"0"0Pb, "2"0"1Pb, "2"0"2"mPb, and "2"0"3Pb radioisotopes in targets from lead with natural isotopic composition, irradiated by 1-GeV protons.
The paper presents results of experimental research on the interaction of a pulsed plasma-ion stream with a tungsten (W) target. The pulsed hydrogen plasma was produced within the RPI-IBIS (Multi-Rod Plasma Injector) facility at IPJ in Swierk. Measurements were carried out by means of optical spectroscopy and corpuscular diagnostic techniques. For experiments with the W-target the operational conditions (so-called PID mode) were chosen when a clean hydrogen plasma stream was generated. Attention was paid to the identification of WI and WII spectral lines.
A modified variable structure interacting multiple model (M-VSIMM) estimator for complex hybrid maneuver target tracking is presented. The M-VSIMM could potentially be applied to fire control systems (FCS) used on warships. Target model groups were designed using 3D dimensional dynamic target models. Optimal model group selection logic was proposed, contrary to the activation and termination logic in the original VSIMM. The system will respond faster with optimal model group selection logic. After performing simulations, the tracking performances of the Kalman, ?-?(-?), VDIE, IMM and M-VSIMM filters were compared under various maneuvering conditions.
Preliminary experiments have been performed to investigate the effects of radiative cooling on plasma jets. Thin (3 um - 5 um) conical shells were irradiated with an intense laser, driving jets with velocities > 100 km/s. Through use of different target materials - aluminium, copper and gold - the degree of radiative losses was altered, and their importance for jet collimation investigated. A number of temporally resoved optical diagnostics was used, providing information about the jet evolution. Gold jets were seen to be narrower than those from copper targets, while aluminium targets produced the least collimated flows.
The velocity distribution of electrons ejected close to the forward direction by 0.8-2 MeV/A ions traversing various solid targets, including a Au monocrystal, is measured in coincidence with emerging charge-selected ions. The velocity spectrum is observed to be independent of outgoing projectile velocity and charge state for polycrystalline targets. Measurements on the Au crystal under channeling conditions show dependences on final charge state, and are tentatively explained by assuming that the main contribution to the production yield comes from the non-channeled fraction of the ions. A simple model for the creation of the forward-ejected electrons is proposed, which accounts for most of the experimental findings.
A computer-assisted rotation and stationary conformation radiotherapy system with overrunning multileaf collimators has been developed. This system can produce any shape of target volume, including a number of target areas outside the axis of the rotation, regardless of the location of the axis at 360"0 rotation irradiation. In addition, by changing the dose rate and deleting a partial region within a field, multiple stationary irradiation can produce more homogeneous target volumes - thus avoiding excessive irradiation to critical organs - than the rotation technique. (orig.).
The centroid and envelope dynamics of a high-intensity charged particle beam are investigated as a beam smoothing technique to achieve uniform illumination over a suitably chosen region of the target for applications to ion-beam-driven high energy density physics and heavy ion fusion. The motion of the beam centroid projected onto the target follows a smooth pattern to achieve the desired illumination, for improved stability properties during the beam-target interaction. The centroid dynamics is controlled by an oscillating "wobbler", a set of electrically-biased plates driven by RF voltage. __________________________________________________
Understanding the physical characteristics of the local microenvironment in which Mycobacterium tuberculosis resides is an important goal that may allow the targeting of metabolic processes...Full Text Available
Several different aspects of the influence of the target backing on in-beam electron spectra following compound nuclear reactions induced by accelerated ions at tandem energies irradiating backed targets are discussed in detail. This discussion is illustrated by a few typical examples, such as "1"2C"5"+ and "3"1P"1"0"+ beams at 4 MeV/u bombarding Sn(+Be), Sn(+Au), Pb(+C) backed targets. Moreover, the relative influence of electron backscattering, electron Doppler shift and Doppler broadening as well as #delta#-electron emission on the low energy electron spectra (E_e#<=#100 keV) obtained under such conditions are investigated in the frame of the available experimental data. (orig.).
Using the complex Kohn method, we have calculated variational values of phase shifts and the annihilation parameter, Z_{eff}, for the elastic scattering of positrons by molecular hydrogen. Our results are sensitive to small changes in the accuracy of the wave function representing the target hydrogen molecule. We have developed a systematic approach to demonstrate that, at low positron energies, there are particular forms of the Kohn trial wave function for which the results of variational calculations are not reliable, even when the target wave function accounts for as much as 96.8% of the correlation energy of H_{2}. We find that reliable results can be recovered if our calculations are extended to admit more sophisticated target wave functions accounting for 99.7% of the correlation energy. Remaining discrepancies between theory and experiment are briefly discussed.
Axon outgrowth and guidance to the proper target requires the coordination of filamentous (F)-actin and microtubules (MTs), the dynamic cytoskeletal polymers that promote shape change and locomotion....Full Text Available
We develop a systematic framework for studying target space duality at the classical level. We show that target space duality between manifolds M and M-tilde arises because of the existence of a very special symplectic manifold. This manifold locally looks like MxM-tilde and admits a double fibration. We analyze the local geometric requirements necessary for target space duality and prove that both manifolds must admit flat orthogonal connections. We show how abelian duality, nonabelian duality and Poisson-Lie duality are all special cases of a more general framework. As an example we exhibit new (nonlinear) dualities in the case M=M-tilde=R{sup n}.
This report discusses the experimental setup of experiment 814 at Brookhaven AGS. This experiment involves the collision of silicon ions with target nuclei. The detector systems are discussed primarily. (LSP)
The oviduct is an exquisitely designed organ that functions in picking-up ovulated oocytes, transporting gametes in opposite directions to the site of fertilization, providing a suitable environment...Full Text Available
Motivation: Automatic recognition of cell identities is critical for quantitative measurement, targeting and manipulation of cells of model animals at single-cell resolution. It has been...Full Text Available
The success of monoclonal antibodies in clinical practice is dependent on good design. Finding a suitable target is the most important part as other properties of the antibody can be altered by genetic...Full Text Available
Many existing agents for diabetes therapy are unable to restore or maintain normal glucose homeostasis or prevent the eventual emergence of hyperglycemia-related complication. Therefore, agents based on novel mechanisms are sought to complement and extend the current therapeutic approaches. Based on the initial paper research, we focused on active STAT3 as an attractive pharmacological target for type 2 diabetes. The subsequent text mining with a unique query to identify suppressors but not activators of STAT3 revealed the ERK2/STAT3 pathway as a novel diabetes target. The description of ERK2 inhibitors as diabetes target had not been found in our text mining research at present. The mechanism-based peptide inhibitor for ERK2 was identified using the knowledge of the KIM sequence, which ha...
Nov 21, 2003... for the European Space Agency's Automated Transport Vehicle, a new, uncrewed station cargo vehicle targeted for launch late next year. ...
Congestive heart failure (CHF) is a leading cause of morbidity and mortality. CHF is marked by atrial and ventricular enlargement and reduced cardiac contractility, as well as an association...Full Text Available
PurposeClinical trials have commenced to evaluate the feasibility of targeting malignant gliomas with genetically engineered cytolytic T-cells (CTLs) delivered directly...Full Text Available
Chaperones (stress proteins) are essential proteins to help the formation and maintenance of the proper conformation of other proteins and to promote cell survival after a large variety of environmental...Full Text Available
In animal models, single-gene mutations in genes involved in insulin/IGF and target of rapamycin signalling pathways extend lifespan to a considerable extent. The genetic, genomic and epigenetic influences...Full Text Available
The eye is an easily accessible, highly compartmentalised and immune-privileged organ that offers unique advantages as a gene therapy target. Significant advancements have been made in understanding...Full Text Available
An application that provides a flexible and easy to use interface to the GAMMA spectral simulation package is described that is targeted at investigations using in vivo MR spectroscopic methods....Full Text Available
The potential of radiolabelled phenylpiperazines as agents for the detection and therapy of tumours of neural crest origin was evaluated by in vitro pharmacological studies with human neuroblastoma...Full Text Available
This letter reports a study designed to measure the benefits of voicing in the recognition of concurrent syllables. The target and distracter syllables were either voiced or whispered, producing...Full Text Available
Dynamic clamp is a powerful method that allows the introduction of artificial electrical components into target cells to simulate ionic conductances and synaptic inputs. This method is based...Full Text Available
... defense's weapons are Space-based kinetic-kill vehicles ... I ti I obtained by dividing the weapons as ... of the optimal weapon-arge assigntments and ...
... In the Proceedings of INTC 2003, we studied charging effects on target coverage during electrospinning (16). ... of Fibers from Electrospinning of ...
The biosynthesis of insect juvenile hormone (JH) and its neuroendocrine control are attractive targets for chemical control of insect pests and vectors of disease. To facilitate the molecular...Full Text Available
The pleiotropic actions of neuromodulators on pre- and postsynaptic targets present challenges to disentangling the mechanisms underlying regulation of synaptic transmission. Within the striatum,...Full Text Available
BackgroundThe metagenomic analysis of microbial communities holds the potential to improve our understanding of the role of microbes in clinical conditions. Recent, dramatic improvements...Full Text Available
The immune system plays a crucial role in maintaining health; however, accumulating evidence indicates that this system can be the target for immunotoxic effects caused by a variety of chemicals including...Full Text Available
BackgroundAmino-terminal signal peptides (SPs) are short regions that guide the targeting of secretory proteins to the correct subcellular compartments in the cell. They are cleaved...Full Text Available
An effective procedure for removing _3H, Xe and Kr from irradiated fuels was demonstrated using Shippingport UO"2 fuel. The release characteristics of _3H, Kr, Xe, and I from irradiated nuclear fuel have been determined as a function of temperature and gaseous environment. Vacuum outgassing and a flowing gas stream have been used to vary the gaseous environment. Vacuum outgassing released about 99% of the _3H and 20% of both Kr and Xe within a 3 h at 1500_0C. Similar results were obtained using a carrier gas of He containing 6% H"2. However, a carrier gas containing only He resulted in the release of approximately 80% of the _3H and 99% of both Kr and Xe. These results indicate that the release of these volatile fission products from irradiated nuclear fuel is a function of the chemical composition of the gaseous environment. The rate of tritium release increased with increasing temperature (1100 to 1500_0C) and with the addition of hydrogen to the gas stream. ...
Incorporation of tritium into body constituent molecules from tritiated water and its in vivo behaviors were studies using rats. In single administration of HTO, "3H behaviors were studied in lipids that are rich in hydrogen. Incorporation of "3H into the lipid fraction from HTO and its release differed by each organ and by the type of lipid components. Of routes of administration, the oral and parenteral routes showed same results, and no prominent difference was noted by inhalation. By consecutive administration, the urine "3H concentration showed no difference according to the route, but increased as the concentration of administered HTO increased. When administration was discontinued after the urine "3H concentration reached a plateau, the biological half-life was about 4.5 days, almost in agreement with the value by single administration. In relation to water intake, increase in the urine volume and accompanying promotion of urine "3H excretion in approximate ...
During Phase 2 of our study of the CIXS conceptual design we have tackled additional important issues that are unique to the ITER environment. These include the thermal control of the crystal and detector enclosures located in an environment with a 100-250 C ambient temperature, tritium containment, and the range of crystal and detector movement based on the need for spectral adjustments and the desire to make measurements of colder plasmas. In addressing these issues we have selected a ''Dewar''-type enclosure for the crystals and detectors. Applying realistic view factors for radiant heat and making allowance for conduction we have made engineering studies of this enclosure and showed that the cooling requirements can be solved and the temperature can be kept sufficiently constant without compromising the specification parameters of the CIXS. We have chosen a minimum 3 mm combined thickness of the six beryllium windows needed in a Dewar-type enclosure and showed ...
Copper coatings deposited on Al-6061 substrates by radio frequency magnetron sputtering, to prevent the retention and permeation of energetically implanted tritium in Al-6061, were evaluated by a variety of characterization techniques. The coatings, weighing in the 0.03 to 0.088 kg/m{sup 2} range, were smooth and had a fine grain structure. They contained the intermetallic phases Cu{sub 9}Al{sub 4} and CuAl{sub 2} as well as copper. The fractions of Al and Cu in any coating increased and decreased, respectively, with increasing depth below the surface. Furthermore, the fractions of Al and Cu on the coating surface decreased and increased, respectively, with increasing coating weight. There was no texture or preferred orientation in the Cu phase of the coatings. A significant amount of oxygen was also detected at the original substrate surface. Residual stress measurements revealed that, in both Cu and CuAl{sub 2}, the stresses in the coating plane were compressive, ...
Carbon fibre composite (CFC) was irradiated by hot plasma streams at plasma gun facility MK-200UG. The CFC targets were tested by plasma loads relevant to Edge Localized Modes (ELM) and mitigated disruptions in ITER. Onset condition of CFC evaporation and properties of evaporated carbon were studied by use of infrared pyrometry and visible spectroscopy.
RNA interference (RNAi) is an effective tool for studying gene function in oocytes, but no studies have targeted somatic cells of primary cultured cumulus cell-oocyte complexes (COCs). This...Full Text Available
Targeted genome capture combined with next-generation sequencing was used to analyze 2.9 Mb of the DFNB79 interval on chromosome 9q34.3, which includes 108 candidate genes. Genomic...Full Text Available
We review the physics of structure functions at low Q{sup 2}, focusing on the phenomenon of quark-hadron duality and the resonance-scaling transition, both phenomenologically and in the context of quark models. We also present a new implementation of target mass corrections to nucleon structure functions which, unlike existing treatments, has the correct kinematic threshold behavior at finite Q{sup 2} in the x -> 1 limit.
Production of lead-203 by proton irradiation of bismuth metal has been investigated as a replacement method for commercially available lead-203. Targets of bismuth metal (0.1 cm thick) were irradiated for periods of 1-3 hours with 90 MeV protons. After processing of the target, the estimated yield of lead-2-3 was 30 millicuries/microamp.
The NREL Sensitized Solar Cell (SSC) Core Program supports the Solar America Initiative by: (1) targeting new devices and processes for commercialization by 2015 that are less expensive, more efficient, highly reliable, and environmentally benign; (2) collaborating with DOE OS/BES to conduct basic research targeting breakthroughs in key areas, such as ultra-high efficiency and/or ultra-low cost materials and devices.
We have developed a set of modeled nuclear reaction cross sections for use in radiochemical diagnostics. Systematics for the input parameters required by the Hauser-Feshbach statistical model were developed and used to calculate neutron induced nuclear reaction cross sections for targets ranging from osmium (Z = 76) to gold (Z = 79). Of particular interest are the cross sections on Ir and Au including reactions on isomeric targets.
LEW anti-DA kidney and DA anti-LEW kidney sera were assayed using an indirect 125I anti-immunoglobulin-binding assay with kidney homogenate as target. This allowed the full spectrum of antibodies to...Full Text Available
The herbicide atrazine is a known immunotoxicant and an inhibitor of human natural killer (NK) cell lytic function. The precise changes in NK cell lytic function following atrazine exposure have not been fully elucidated. The current study identifies the point at which atrazine exerts its affect on the stepwise process of human NK cell-mediated lyses of the K562 target cell line. Using intracellular staining of human peripheral blood lymphocytes, it was determined that a 24-h in vitro exposure to atrazine did not decrease the level of NK cell lytic proteins granzyme A, granzyme B or perforin. Thus, it was hypothesized that atrazine exposure was inhibiting the ability of the NK cells to bind to the target cell and subsequently inhibit the release of lytic protein from the NK cell. To test this hypothesis, flow cytometry and fluorescent microscopy were employed to analyze NK cell-target cell co-cultures following atrazine ...
Gene silencing is a useful technique for elucidating biological function of genes by knocking down their expression. A recently developed artificial microRNAs (amiRNAs) exploits an endogenous...Full Text Available
An electron accelerator unit is described for electron beam therapy, comprising: a source of an electron beam; means for finally directing at least a portion of the beam to a therapy site, the directing means being mechanically independent of, and electrically isolated from, the source, and having a target area; and means for aligning the source with the directing means, the aligning means comprising means for projecting at least one beam of light from the source toward the target area.
An electron accelerator unit is described for electron beam therapy, comprising: a source of an electron beam; means for finally directing at least a portion of the beam to a therapy site, the directing means being mechanically independent of, and electrically isolated from, the source, and having a target area; and means for aligning the source with the directing means, the aligning means comprising means for projecting at least one beam of light from the source toward the target area.
Measurements of the double-electron-capture process in which a positive ion of iodine becomes a negative ion in a single collision with a magnesium atom are reported between 20 and 90 keV. The cross section is comparable to that for the rare gases and not as large as might be expected from a two-valence-electron atom. This process is probably insignificant in the production of negative ion beams using a magnesium-vapor target.
PNNL, with cofunding from the Bonneville Power Administration (BPA) and Building Technologies Program, conducted a research and development activity targeted at addressing the energy efficiency goals targeted in the BPA roadmap. PNNL investigated an integrated heating, ventilation and air conditioning (HVAC) system option referred to as the low-lift cooling system that potentially offers an increase in HVAC energy performance relative to ASHRAE Standard 90.1-2004.
A new proprietary de novo peptide design technique generated ten 15-residue peptides targeting and containing the leading nontransmembrane hydrophobic autocorrelation wavelengths, “modes”,...Full Text Available
BACKGROUND:Despite an increasing body of evidence on the benefit of lowering elevated levels of low-density lipoprotein cholesterol (LDL-C), there is still considerable concern that...Full Text Available
MicroRNAs are short (∼22 nucleotides) noncoding RNAs that regulate the stability and translation of mRNA targets. A number of computational algorithms have been developed to help predict which...Full Text Available
The in situ assembly states of the glucose transport carrier protein in the plasma membrane and in the intracellular (microsomal) storage pool of rat adipocytes were assessed by studying radiation-induced inactivation of the D-glucose-sensitive cytochalasin B binding activities. High energy radiation inactivated the glucose-sensitive cytochalasin B binding of each of these membrane preparations by reducing the total number of the binding sites without affecting the dissociation constant. The reduction in total number of binding sites was analyzed as a function of radiation dose based on target theory, from which a radiation-sensitive mass (target size) was calculated. When the plasma membranes of insulin-treated adipocytes were used, a target size of approximately 58,000 daltons was obtained. For adipocyte microsomal membranes, we obtained target sizes of approximately 112,000 and 109,000 daltons prior ...
The ratio of the proton's electric to magnetic form factor, G{sub E}/G{sub M}, can be extracted in elastic electron-proton scattering by measuring cross sections, beam-target asymmetry, or recoil polarization. Separate determinations of G{sub E}/G{sub M} by cross sections and recoil polarization observables disagree for Q{sup 2}>1 (GeV/c){sup 2}. Measurement by a third technique might uncover an unknown systematic error in either of the previous measurements. The beam-target asymmetry has been measured for elastic electron-proton scattering at Q{sup 2} = 1.51 (GeV/c){sup 2} for target spin orientation aligned perpendicular to the beam momentum direction. This is the largest Q{sup 2} at which G{sub E}/G{sub M} has been determined by a beam-target asymmetry experiment. The result, {mu}G{sub E}/G{sub M}=0.884{+-}0.027{+-}0.029, is compared to previous world data.
Target recognition requires the ability to distinguish targets from non-targets, a capability called one-class generalization. To function as a one-class classifier, a neural network must have three types of generalization: within-class, between-class, and out-of-class. We discuss these three types of generalization and identify neural network architectures that meet these requirements. We have applied our one-class classifier ideas to the problem of automatic target recognition in synthetic aperture radar. We have compared three neural network algorithms: Carpenter and Grossberg`s algorithmic version of the Adaptive Resonance Theory (ART-2A), Kohonen`s Learning Vector Quantization (LVQ), and Reilly and Cooper`s Restricted Columb Energy network (RCE). The ART 2-A neural network has given the best results, with 100% within-class, and out-of-class generalization. Experiments show that the network`s ...
Target recognition requires the ability to distinguish targets from non-targets, a capability called one-class generalization. Many neural network pattern classifiers fail as one-class classifiers because they use open decision boundaries. To function as one-class classifier, a neural network must have three types of generalization: within-class, between-class, and out-of-class. We discuss these three types of generalization and identify neural network architectures that meet these requirements. We have applied our one-class classifier ideas to the problem of automatic target recognition in synthetic aperture radar. We have compared three neural network algorithms: Carpenter and Grossberg`s algorithmic version of the Adaptive Resonance Theory (ART-2A), Kohonen`s Learning Vector Quantization (LVQ), and Reilly and Cooper`s Restricted Coulomb Energy network (RCE). The ART 2-A neural network gives the best ...
Obtained experimental data on integral cross sections (ICS) of inelastic scattering of 50.5 MeV #alpha# particles with the excitation of "6","7Li, "9Be, "1"2","1"3C, "1"4C, "1"4N, "2"0Ne, "2"4Mg, "2"8Si nucleus low-lying energy levels are discussed. Regularities, detected in the behaviour of ICS forward scattering for 20-90 deg angles and backscattering for 90-160 deg angles for the target-nucleus under investigation are considered. Effect of reaction open channel number on #alpha#-particle scattering ICS where n,p,d- and #alpha#-channels were considered as the main channels for all the target-nuclei, is discussed. Dependence of #alpha#-particle scattering ICS on the target-nucleus level excitation energy and dependences of reaction open channel number on the channel spin, calculated for 50.5 MeV #alpha# particles and different target nuclei are shown in the diagrams. It is noted that the observed ...
Background: the authors report on the conception and first clinical application of a donut-shaped high-dose configuration for proton therapy (PT). This approach allows one to intensify target volume dose coverage for targets encompassing a critical, dose-limiting structure - like here, the cauda equina -, whilst delivering minimal dose to other healthy structures surrounding the target, thereby reducing the integral dose. Methods and results: intensity-modulated PT methods (IMPT) for spot scanning were applied to create and deliver a donut-shaped high-dose configuration with protons, allowing treating > 75% of the target with at least 95% of the prescribed dose of 72.8 CGE, whilst restricting dose to the cauda equina to 60-65 CGE. Integral dose was lower by a factor of 3.3 as compared to intensity-modulated radiotherapy with photons (IMXT). Conclusion: IMPT and spot scanning technology allow a ...
Background: the authors report on the conception and first clinical application of a donut-shaped high-dose configuration for proton therapy (PT). This approach allows one to intensify target volume dose coverage for targets encompassing a critical, dose-limiting structure - like here, the cauda equina -, whilst delivering minimal dose to other healthy structures surrounding the target, thereby reducing the integral dose. Methods and results: intensity-modulated PT methods (IMPT) for spot scanning were applied to create and deliver a donut-shaped high-dose configuration with protons, allowing treating > 75% of the target with at least 95% of the prescribed dose of 72.8 CGE, whilst restricting dose to the cauda equina to 60-65 CGE. Integral dose was lower by a factor of 3.3 as compared to intensity-modulated radiotherapy with photons (IMXT). Conclusion: IMPT and spot scanning technology allow a ...
The transport and partitioning of {sup 129}I has been examined for a shallow groundwater flow system at Sturgeon Falls in northeastern Ontario. Recharge into a sandy surficial postglacial deltaic aquifer occurs in the vicinity of a seasonally-wet boreal forest. Concentrations of stable iodine, {sup 129}I, tritium, radiocarbon, stable isotopes and major ions were measured on samples of groundwater and precipitation. The present-day tritium profile delineates the position of the early 1960's above-ground nuclear weapons pulse at a depth of approximately 12 m. The concentrations of stable iodine for groundwaters above, near and below the above-ground nuclear weapons pulse range from 0.07 to 1.7 ppb. Over that same interval {sup 129}I concentrations decreased from 1.9 x 10{sup 6} atoms/L at 9 m, to approximately 1.9 x 10{sup 5} atoms/L in tritium-depleted waters at 35 m, below the present-day depth of the recharging ...
Full text: During JET operations, tritium contaminated waste is generated principally but not exclusively from 'intervention' work and from removing or replacing redundant items. It is essential for JET and for any future fusion plant to have available a route for managing each waste stream however large or small, both during operation and decommissioning of the plant. The long term outcome is to have for each tritiated waste stream from JET a route for its management leading to its eventual disposal or recycling (and thus to be available for similar waste streams which will be produced by ITER operations). Since several years SCK#centre dot#CEN has been developing techniques for the treatment of tritiated waste. Amongst them, technologies for water detritiation, for the treatment of tritiated organic liquids and for the decontamination of several types of solid tritiated waste. Our R and D focuses on the development of a system to decontaminate surface ...
Measurements using radioactive targets are important for the determination of key reaction path ways associated with the synthesis of the elements in nuclear astrophysics (sprocess), advanced fuel cycle initiative (transmutation of radioactive waste), and stockpile stewardship. High precision capture cross-section measurements are needed to interpret observations, predict elemental or isotopical ratios, and unobserved abundances. There are two new detector systems that are presently being commissioned at Los Alamos National Laboratory for very precise measurements of (n,{gamma}) and (n,f) cross-sections using small quantities of radioactive samples. DANCE (Detector for Advanced Neutron-Capture Experiments), a 4 {pi} gamma array made up of 160 BaF{sub 2} detectors, is designed to measure neutron capture cross-sections of unstable nuclei in the low-energy range (thermal to {approx}500 keV). The high granularity and high detection efficiency of DANCE, combined with ...
With the aim of preparing carrier-free "2"8Mg and "4"7Ca simultaneously, Ti, V and Fe targets were examined by irradiating with high-energy ions of "1"2C, "1"4N and "1"6O accelerated by the RIKEN ring cyclotron. Among the targets, V gave the highest cross section for the formation of both "2"8Mg and "4"7Ca irrespective of the kind of beams. The cross section for the formation of "2"8Mg by the reactions of Ti, V and Fe targets with ion beams increased in the order of "1"2C<"1"6O<"1"4N. On the other hand, the three beams exhibited almost the same cross sections for the formation of "4"7Ca by the reaction of a given target. Titanium and V were selected as prospective targets and "1"4N as a suitable beam for the production of "2"8Mg and "4"7Ca. Chemical separation procedures of the radiotracers in carrier- and salt-free states have been established by using cation exchange resins. ...
To improve mirrors coating, we have modeled sputtering of binary oxide targets using TRIM code. First, we have proposed a method to calculate TRIM input parameters using on the one hand thermodynamic cycle and on the other hand Malherbe`s results. Secondly, an iterative processing has provided for oxide steady targets caused by ionic bombardment. Thirdly, we have exposed a model to get experimental sputtering yields. Fourthly, for (Ar - SiO{sub 2}) pair, we have determined that steady target is a silica one. A good agreement between simulated and experimental yields versus ion incident angle has been found. For (Ar - Ta{sub 2} O{sub 5}) pair, we have to introduce preferential sputtering concept to explain discrepancy between simulation and experiment. In this case, steady target is tantalum monoxide. For (Ar - Ta+O{sub 2}) pair, tantalum sputtered by argon ions in reactive oxygen atmosphere, we have to ...
Full text: Measurement of K_#beta# to K_#alpha# x-ray intensity ratios are important not only in the field of atomic physics, radiation physics and medical physics, but also to test the validity of assumptions made in the theoretical prediction. The intensity ratios can also give information on the effect of physical and chemical environment of the element in the compound. Many investigators have adopted a single and double reflection geometries to measure the K_#beta# to K_#alpha# x ray intensity ratios to understand the effect of physical and chemical environment on x-ray fluorescence. The targets are excited by a radioactive source of having activity of the order 100 MBq. in order to carry out accurate measurement K_#beta# to K_#alpha# x-ray intensity ratios, we have develop 2#pi# geometrical configuration method : placing a target right on the surface of the detector facing the target to measure the K shell fluorescence ...
Neutron and gamma ray energy spectra were measured using an NE-213 scintillator at depths of 7.2, 15.2, and 22.2 cm in a tissue-equivalent phantom which was uniformly irradiated on one face by deuterium--tritium (DT) neutrons. Coupled neutron--gamma ray multigroup discrete-ordinates calculations were performed using semi-infinite slab geometry. These calculations were used to supplement the measured spectra below 1 MeV. Similar calculations were performed to study the perturbation in the phantom due to the detector. The measured and calculated spectra were used to determine the kerma distributions for neutrons and gamma rays at each location. The gamma radiation was determined to contribute more than 10% of the total dose at each depth. The calculated kerma also reveals that a knowledge of the gamma ray spectra below 1 MeV is desirable. Key words: neutron--gamma spectra, spectrometry, kerma distributions, coupled multigroup calculations
Neutron and gamma ray energy spectra were measured using an NE-213 scintillator at depths of 7.2, 15.2, and 22.2 cm in a tissue-equivalent phantom which was uniformly irradiated on one face by deuterium--tritium (DT) neutrons. Coupled neutron--gamma ray multigroup discrete-ordinates calculations were performed using semi-infinite slab geometry. These calculations were used to supplement the measured spectra below 1 MeV. Similar calculations were performed to study the perturbation in the phantom due to the detector. The measured and calculated spectra were used to determine the kerma distributions for neutrons and gamma rays at each location. The gamma radiation was determined to contribute more than 10% of the total dose at each depth. The calculated kerma also reveals that a knowledge of the gamma ray spectra below 1 MeV is desirable. Key words: neutron--gamma spectra, spectrometry, kerma distributions, coupled multigroup calculations.
To understand the environmental dispersion trend of "3H and "1"4C discharged from the Wolsung nuclear power plant, the present levels of "3H and "1"4C in environmental samples in the vicinity of the Wolsong site were studied. During 1992 through 2002, the annual means of HTO and "1"4C concentrations in air collected at three sampling stations around Wolsong nuclear power plant were in the range of 1.13 #approx# 29.2 Bq m"-"3 and 0.33 #approx# 0.40 Bq g-C"-"1 respectively, decreasing with distance from the site. The annual mean of TFWT concentrations in pine needle was in the range of 104 #approx# 790 Bq L"-"1 at N-1 and 62.8 #approx# 298 Bq L"-"1 at S"-"2, while the annual mean of "1"4C concentration was in the range of 0.335 #approx# 0.897 g-C"-"1 at N-1 and 0.254 #approx# 0.332 Bq g-C"-"1 #approx# at S"-"2, showing elevated value than a 0.25 Bq g-C"-"1 of background level. (author)
The design of solid breeder blankets is strongly affected by the low values of thermal conductivity and density of ceramic breeder pebble beds. A significant rise of both quantities would enhance the thermal performance and lead to an increased tritium breeding ratio. In order to improve these quantities pretreated lithium orthosilicate pebble material was dry pressed and subsequently sintered. The thermal conductivity of cylindrical pellets was determined by the heat pulse method using a laser flash device. A pebble bed characteristic sample was also investigated in order to check the measurement accuracy in comparison with previous results. Furthermore, two samples of low density cellular ceramics were also prepared by infiltration of polymer foams with a ceramic slurry. The thermal conductivity results show that the values are affected both by the particle size and the sample density. Thermal conductivity values of higher than 2 W/m K were obtained using large ...
The authors investigated the effect of T-2 toxin on rat liver mitochondrial protein synthesis. Isolated rat liver mitochondria were supplemented with an S-100 supernatant from rat liver and an external ATP-generating system. An in-vitro assay employing cycloheximide, and inhibitor of cytoplasmic protein synthesis, and chloramphenicol, and inhibitor of mitochondrial protein synthesis, to distinguish mitochondrial protein synthesis from the cytoplasmic process. Amino acid incorporation into mitochondria was dependent on the concentration of mitochondria and was inhibited by chloramphenicol. The rate of uptake of tritium leucine into mitochondrial protein was unaffected by the addition of T-2 toxin and was not a rate-limiting step in incorporation. However, 0.02 micrograms/ml of T-2 toxin decreased the rate of protein synthesis inhibition correlated with the amount of T-2 toxin taken up by the mitochondria. While T-2 toxin is known to inhibit eukaryotic protein ...
We study the sensitivity to neutrino masses of a Galactic supernova neutrino signal as could be measured with the detectors presently in operation and with future large volume water \\v{C}erencov and scintillator detectors. The analysis uses the full statistics of neutrino events. The method proposed uses the principles of Bayesian inference reasoning and has shown a remarkably independence of astrophysical assumptions. We show that, after accounting for the uncertainties in the detailed astrophysical description of the neutrino signal and taking into account the effects of neutrino oscillations in the supernova mantle, detectors presently in operation can have enough sensitivity to reveal a neutrino mass (or to set upper limits) at the level of 1 eV. This is sensibly better than present results from tritium $\\beta$-decay experiments, competitive with the most conservative limits from neutrinoless double $\\beta$-decay and less precise but remarkably less ...
Lithium isotopes are used as the raw material of tritium which is the fuel for fusion power generation and the material for fusion reactors, accordingly those are indispensable for future nuclear fusion power generation. As for boron isotopes, the neutron absorption corss section is very large, therefore, they are used for shielding neutrons and controlling fast neutron reactors. In order to further develop the utilization of nuclear power, it is important to develop the technology for separating and refining light element isotopes in large amount. In fiscal year 1995, the relation of the ion sieve characteristics of inorganic ion exchanger and the behavior of lithium isotope separation was examined. The behavior of forming boron complex of polyol amine was examined by B-11 NMR. These experiments and the results are reported. It was shown to be feasible that lithium is adsorbed from seawater, and isotopes are concentrated. Titanium phosphate and its heat treated ...
The use of deuterium-tritium fuel in the Compact Ignition Tokamak will require applying remote handling technology for ex-vessel maintenance and replacement of machine components. Highly activated and contaminated components of the fusion devices auxiliary systems, such as diagnostics and RF heating, must be replaced using remotely operated maintenance equipment in the test cell. In-vessel remote maintenance included replacement of divertor and first wall hardware, faraday shields, and for an in-vessel inspection system. Provision for remote replacement of a vacuum vessel sector, toroidal field coil or poloidal field ring coil was not included in the project baseline. As a result of recent coil failures experienced at a number of facilities, the CIT project decided to reconsider the question of remote recovery from a coil failure and, in January of 1990, initiated a coil replacement study. This study focused on the technical requirements and impact on fusion ...
Examination of a chloroform extract of Dracaena loureiri Gagnep (Agavaceae), a Thia medicinal plant possessing antibacterial activity, has led to the isolation of fifteen flavenoids. The biogenic relationships among these flavenoids isolated were briefly discussed. Definition of the skeleton and the unambiguous assignment of all of the protons of the isolates was achieved through extensive 2D-homonuclear chemical shift correlation, nuclear Overhauser effect (NOE) difference spectroscopy and 2D-NOE experiments. The {sup 1}H and {sup 13}C NMR spectra of staurosporine, a potent biologically active agent from Streptomyces staurosporeus, were unambiguously assigned by using 2D homonuclear chemical shift correlation, NOE, {sup 1}H-detected heteronuclear multiple-quantum coherence via direct coupling and via multiple-bond coupling for resonance assignments of protonated and nonprotonated carbons, respectively. S. Staurosporeus was found to utilize endogenous and exogenous D- and L-isomers of ...
A technique has been developed for high resolution alpha particle spectroscopy from track length determination in CR-39 plastic. On individual tracks an energy resolution deltaE close to the range straggling limit is obtainable. For 6 MeV alpha-particle deltaE is proportional 35 keV on individual particles and for groups of particles deltaE proportional 20 keV can be achieved using certain data selection criteria. At 100 keV on individual particles deltaE is proportional 20 keV. The analysis requires 1) a knowledge of the track-etch rate (Vsub(T))-range relationship and 2) a theoretical understanding of alpha-particle track structure in CR-39 as a function of particle energy, dip angle and degree of etching. The structure of alpha-particle etched tracks in CR-39 is described and two methods of analysis discussed. Examples are given of the resolution attainable on tracks of alpha-particles as natural decay energy and from alpha-particles generated in laser driven deuterium and ...
Environmental characteristics of conceptual fusion-reactor systems based on magnetic confinement are examined quantitatively, and some comparisons with fission systems are made. Fusion, like all other energy sources, will not be completely free of environmental liabilities, but the most obvious of these-- tritium leakage and activation of structural materials by neutron bombardment-- are susceptible to significant reduction by ingenuity in choice of materials and design. Large fusion reactors can probably be designed so that worst-case releases of radioactivity owing to accident or sabotage would produce no prompt fatalities in the public. A world energy economy relying heavily on fusion could make heavy demands on scarce nonfuel materials, a topic deserving further attention. Fusion's potential environmental advantages are not entirely ''automatic'', converting them into practical reality will ...
The PERMCAT process chosen for the final clean-up stage of the Tokamak Exhaust Processing system of the ITER tritium plant combines in a single component a catalytic reactor and a permeator using Pd/Ag membranes. This study covers the mechanical behaviour of a Pd/Ag membrane under different operating conditions. The consequences of hydrogen uptake by the membrane during nominal operation but also during off-normal events are presented. Depending on the operating conditions, expansions around 2% and significant deformations are observed. Different mechanical designs of PERMCAT reactors are then discussed. The first generation comprises finger-type membranes and two new mechanical designs use either additional edge welded bellows or a special corrugated Pd/Ag membrane. These upgraded designs improve the robustness and simplify the geometry of the component. The experimental validation of these new units has been carried out based on the measurements of the processing ...
The PERMCAT process chosen for the final clean-up stage of the Tokamak Exhaust Processing system of the ITER tritium plant combines in a single component a catalytic reactor and a permeator using Pd/Ag membranes. This study covers the mechanical behaviour of a Pd/Ag membrane under different operating conditions. The consequences of hydrogen uptake by the membrane during nominal operation but also during off-normal events are presented. Depending on the operating conditions, expansions around 2% and significant deformations are observed. Different mechanical designs of PERMCAT reactors are then discussed. The first generation comprises finger-type membranes and two new mechanical designs use either additional edge welded bellows or a special corrugated Pd/Ag membrane. These upgraded designs improve the robustness and simplify the geometry of the component. The experimental validation of these new units has been carried out based on the measurements of the processing ...
ACRO, a NGO equipped with a laboratory to measure radioactivity, runs the Citizen Watchdog of Radioactivity in the Environment. Involving many volunteers, it monitors regularly the French coast of the Channel and many rivers of the North half of France. It also makes investigations in other places. Such an action is aimed to supplement the official monitoring, not to replace it, in order to answer to the worries of the population. This monitoring shows that some radioelements, such as iodine 129, cobalt 60, tritium, etc. released in the environment by nuclear facilities can be detected on very large areas. Carbon 14 was detected up to almost 4 times the background in vegetables around the reprocessing plant of La Hague. ACRO also sits in many official committees to transmit the point of view of the populations exposed to the radioactive pollution. It is lobbying for a decrease of the release authorization, especially for the elements that are discharged in large ...
The irradiation behavior of Li{sub 2}TiO{sub 3} under a fusion reactor environment was simulated by simultaneous irradiation of Li{sub 2}TiO{sub 3} by the triple ion beams and the respective single ion beams of O{sup 2+}, He{sup +} and H{sup +}. The microstructural changes in Li{sub 2}TiO{sub 3} caused by the irradiation were measured by FT-IR photoacoustic spectroscopy. The results suggest that the amount of TiO{sub 2} formed is proportional to the dpa and that the method of irradiation does not affect the dependence of formation of TiO{sub 2}. On the other hand, the amount of defects and/or radiolytic products generated by irradiation, which is considered to trap hydrogen near the surface, is found to be affected by the method of irradiation. Such phenomena are believed to affect the tritium release behavior from Li{sub 2}TiO{sub 3}, and durability of Li{sub 2}TiO{sub 3} and compatibility of Li{sub 2}TiO{sub 3} with other components of the breeder blanket such as ...
The irradiation behavior of Li_2TiO_3 under a fusion reactor environment was simulated by simultaneous irradiation of Li_2TiO_3 by the triple ion beams and the respective single ion beams of O"2"+, He"+ and H"+. The microstructural changes in Li_2TiO_3 caused by the irradiation were measured by FT-IR photoacoustic spectroscopy. The results suggest that the amount of TiO_2 formed is proportional to the dpa and that the method of irradiation does not affect the dependence of formation of TiO_2. On the other hand, the amount of defects and/or radiolytic products generated by irradiation, which is considered to trap hydrogen near the surface, is found to be affected by the method of irradiation. Such phenomena are believed to affect the tritium release behavior from Li_2TiO_3, and durability of Li_2TiO_3 and compatibility of Li_2TiO_3 with other components of the breeder blanket such as structural materials in the fusion reactor system under operation.
Fusion energy has been studied in many countries such as U.S., France, Japan, Korea etc. Because it would provide much more energy for a given weight of fuel than any technology currently in use, and the fuel itself (primarily deuterium) exists abundantly in the Earth's ocean. Nuclear fusion reactor uses tritium and deuterium as fuel while nuclear fission reactor uses uranium and plutonium as fuel. Besides, inherent design characteristics and driving condition of nuclear fusion reactor is different from those of nuclear fission reactor. Therefore, we cannot apply the regulation rules of nuclear fission reactor to nuclear fusion reactor without change and thus it is needed to development of the safety regulation concept which reflects the characteristics of nuclear fusion reactor. Safety regulation of nuclear fusion reactor employs deterministic approach until sufficient data are secured. However, regulation methodology of nuclear fusion reactor should be based on ...
Changes in contents of the two kinds of neuropeptides have been measured in the brains of postnatal G57BL/6J strain mice that received accumulative doses of 0, 0.05, 0.10 or 0.30 Gy respectively in utero from tritium #beta#-irradiation during the mother mice's pregnancy from the 12.5th day of gestation to the day of delivery. Dose response relationship for alteration in somatostatin content due to exposure to 0.10 Gy or above was observed, and it was also noted that 0.30 Gy could cause decrease in arginine vasopressin in hypothalamus. These results were consistent with findings in research on brain development and reflex behavior in the literature. 0.10 Gy exposure may represent a threshold for exposure to tritiated water within the range from day 12.5 of gestation to the day of delivery using change in content of somatostatin in hypophysis as a parameter.
ESH-19 personnel collected soil and single-stage water samples around the perimeter of Area G at Los Alamos National Laboratory during FY94 to characterize possible contaminant movement out of Area G through surface-water and sediment runoff. These samples were analyzed for tritium, total uranium, isotopic plutonium, americium-241, and cesium-137. Ten metals were also analyzed on selected soils using analytical laboratory techniques. All radiochemical data are compared with analogous samples collected during FY 93 and reported in LA-12986. Baseline concentrations for future disposal operations were established for metals and radionuclides by a sampling program in the proposed Area G Expansion Area. Considering the amount of radioactive waste that has been disposed at Area G, there is evidence of only low concentrations of radionuclides on perimeter surface soils. Consequently, little radioactivity is leaving the confines of Area G via the surface water runoff ...
The general development of variational methods for fusion reactor blanket studies is given. Important quantities such as tritium breeding ratio and total nuclear heating are linear functionals of the solutions to the Boltzmann transport equation. To estimate a neutronic quantity by variational methods is, in general, to carry out the scalar product formulation of the Roussopoulos variational principle, or the Schwinger variational principle, with the help of the associated adjoint transport equation where the appropriate response function for the estimate is taken as the source. A multipoint interpolation method based on the above variational principles has been developed and compared to other variational approaches. The method of variational interpolation removes the need to compute both forward and adjoint solutions while the error has the characteristic of cancellation of errors between interpolation reference points. Finally, the practical computational ...
A generic reactor model is used to examine the economic viability of electricity generation by magnetic fusion. The simple model uses components which are representative of those used in previous reactor studies of deuterium-tritium burning tokamaks, stellarators, bumpy tori, reverse field pinches and tandem mirrors. Conservative costing assumptions are made. The generic reactor is not a tokamak but rather it is intended to emphasize what is common to all magnetic fusion reactors. The reactor uses a superconducting toroidal coil set to produce the dominant magnetic field. To this extent it is a less good approximation to systems, such as the reversed field pinch in which the main field is produced by a plasma current. The main output of the study is the cost of electricity as a function of the weight and size of the fusion core - blanket, shield, structure and coils. The model shows that a 1200 MW/sub e/ power plant with a fusion core weight of about 10,000 tonnes ...
ARIES-AT is a 1000 MWe conceptual fusion power plant design with a very low projected cost of electricity. The design contains many innovative features to improve both the physics and engineering performance of the system. From the safety and environmental perspective, there is greater depth to the overall analysis than in past ARIES studies. For ARIES-AT, the overall spectrum of off-normal events to be examined has been broadened. They include conventional loss of coolant and loss of flow events, an ex-vessel loss of coolant, and in-vessel off-normal events that mobilize in-vessel inventories (e.g., tritium and tokamak dust) and bypass primary confinement such as a loss of vacuum and an in-vessel loss of coolant with bypass. This broader examination of accidents improves the robustness of the design from the safety perspective and gives additional confidence that the facility can meet the no-evacuation requirement under average weather conditions. We also provide ...
ARIES-AT is a 1000 MWe conceptual fusion power plant design with a very low projected cost of electricity. The design contains many innovative features to improve both the physics and engineering performance of the system. From the safety and environmental perspective, there is greater depth to the overall analysis than in past ARIES studies. For ARIES-AT, the overall spectrum of off-normal events to be examined has been broadened. They include conventional loss of coolant and loss of flow events, an ex-vessel loss of coolant, and in-vessel off-normal events that mobilize in-vessel inventories (e.g., tritium and tokamak dust) and bypass primary confinement such as a loss of vacuum and an in-vessel loss of coolant with bypass. This broader examination of accidents improves the robustness of the design from the safety perspective and gives additional confidence that the facility can meet the no-evacuation requirement under average weather conditions. We also provide ...
This report is a compilation of the groundwater sampling results from the Area 5 Radioactive Waste Management Site (RWMS) including calendar year 2008 results. Each of the three Pilot Wells was sampled on March 11, 2008, and September 10, 2008. These wells were sampled for the following indicators of contamination: pH, specific conductance, total organic carbon, total organic halides, and tritium. Indicators of general water chemistry (cations and anions) were also monitored. Results from all samples collected in 2008 were within the limits established by agreement with the Nevada Division of Environmental Protection for each analyte. These data indicate that there has been no measurable impact to the uppermost aquifer from the Area 5 RWMS. There were no significant changes in measured groundwater parameters compared to previous years. Other information in the report includes an updated Cumulative Chronology for the Area 5 RWMS Groundwater Monitoring Program and ...
This report is a compilation of the groundwater sampling results from the Area 5 Radioactive Waste Management Site (RWMS) for calendar year 2006. Pilot wells UE5PW-1, UE5PW-2, and UE5PW-3 were sampled in April and October 2006 for the following indicators of contamination: pH, specific conductance, total organic carbon, total organic halides, and tritium. Indicators of general water chemistry (cations and anions) were also monitored. Results from all samples collected in 2006 were within the limits established by agreement with the Nevada Division of Environmental Protection for each analyte. These data indicate that there has been no measurable impact to the uppermost aquifer from the Area 5 RWMS. There were no significant changes in measured groundwater parameters compared to previous years. Other information in the report includes an updated Cumulative Chronology for the Area 5 RWMS Groundwater Monitoring Program and a brief description of the site hydrogeology.
Environmental monitoring data were collected at and around the Area 3 and Area 5 Radioactive Waste Management Sites (RWMSs) at the Nevada Test Site. These data are associated with radiation exposure, air, groundwater, meteorology, vadose zone, subsidence, and biota. This report summarizes the 2006 environmental data to provide an overall evaluation of RWMS performance and to support environmental compliance and performance assessment (PA) activities. Some of these data (e.g., radiation exposure, air, and groundwater) are presented in other reports (U.S. Department of Energy, 2006; Warren and Grossman, 2007; National Security Technologies, LLC, 2007). Direct radiation monitoring data indicate that exposure levels around the RWMSs are at or below background levels. Air monitoring data at the Area 3 and Area 5 RWMSs indicate that tritium concentrations are slightly above background levels. There is no detectable man-made radioactivity by gamma spectroscopy, and ...
Full text of publication follows: Li{sub 2}TiO{sub 3} is regarded as one of the most suitable candidates for the solid tritium breeder material of D-T fusion reactors. It is known that, in an operating fusion reactor, the radiation damage in Li{sub 2}TiO{sub 3} will be caused by fast neutrons, energetic tritons and helium ions generated in {sup 6}Li(n,{alpha}){sup 3}H reaction. The irradiation damage caused by such radiation may result in the microstructural changes, and the changes may affect the characteristics of Li{sub 2}TiO{sub 3} such as tritium release behavior. Thus the study of irradiation defects and microstructural changes caused by irradiation in Li{sub 2}TiO{sub 3} is essential to evaluate its irradiation performance. Simulation of the fusion reactor environment and hence the study of a synergistic effect of atomic displacement damage in Li{sub 2}TiO{sub 3} are approached by a simultaneous irradiation with ...
We demonstrate the use of a variational method to determine a quantitative lower bound on the rate of convergence of Markov Chain Monte Carlo (MCMC) algorithms as a function of the target density and proposal density. The bound relies on approximating the second largest eigenvalue in the spectrum of the MCMC operator using a variational principle and the approach is applicable to problems with continuous state spaces. We apply the method to one dimensional examples with Gaussian and quartic target densities, and we contrast the performance of the basic Metropolis-Hastings algorithms with a ``smart'' variant that incorporates gradient information into the trial moves. We find that the variational method agrees quite closely with numerical simulations. We also see that the smart MCMC algorithm often fails to converge geometrically in the tails of the target density except in the simplest case we examine, and even then care ...
Transmission nuclear resonance fluorescence measurements were made on targets consisting of Pb and depleted U with total areal densities near 86g/cm"2. The "2"3"8U content in the targets varied from 0% to 8.5% (atom fraction). The experiment demonstrates the capability of using transmission measurements as a non-destructive technique to identify and quantify the presence of an isotope in samples with thicknesses comparable to the average thickness of a nuclear fuel assembly. The experimental data also appear to demonstrate the process of notch refilling with a predictable intensity. Comparison of measured spectra to previous backscatter "2"3"8U measurements indicates general agreement in observed excited states. Evidence of two new "2"3"8U excited states and possibly a third state have also been observed.
The introduction of oxygen in the vicinity of a metallic target surface, bombarded with positive argon ions of twenty kiloelectron-volts, increases the number of sputtered atoms in the excited state. This phenomenon of exaltation, very sensitive in the case of nickel and aluminium, is much less marked in the case of molybdenum. Moreover, the emission of excited particles coming from the beam's ions is not modified. A quantum-mechanical model of a kinetic emission process, which permits the interpretation of the clean metallic target's emission phenomena, seems insufficient to explain all of the results obtained in the presence of oxygen. In this last case one can therfore use a thermodynamic model in which excited metallic particles can be formed directly by chemical surface reactions of neutralization or reduction. (orig.).
A promising drug target currently under investigation to improve cognitive deficits in neuropsychiatric and neurological disorders is the neuronal nicotinic alpha7 acetylcholine receptor (a7nAChR). Improving cognitive impairments in diseases such as Alzheimer's (AD) and schizophrenia remains a large unmet medical need, and the a7nAChR has many properties that make it an attractive therapeutic target. The a7nAChR is a ligand gated ion channel that has particularly high permeability to Ca^2^+ and is expressed in key brain regions involved in cognitive processes (e.g., hippocampus). The a7nAChRs are localized both pre-synaptically, where they can regulate neurotransmitter release, and post-synaptically where they can activate intracellular signaling cascades and influence downstream processes...
The main goal of local drug delivery is to increase the concentration of a specific therapeutic agent in a target tissue with minimal nontarget distribution. Compared to systemic therapy, local drug delivery provides a high level of therapeutic efficacy with minimal systemic effects. The current primary imaging modality for drug delivery has been x-ray angiography, but it has major limitations including anatomical ambiguity and inability to visualize the targeted tissues. Due to these inherent problems, MR guidance has been explored as an alternative imaging modality for guiding and monitoring of drug therapy. Recently, interventional MR (XMR) systems have been implemented that have both dual x-ray and MRI capabilities in a single suite and allow for real-time interventional procedures to ...
A new procedure of fuel layering for the Fast Ignition Realization Experiment (FIREX) target is proposed. A conical laser guide heating technique was experimentally demonstrated in principle as the followings. It employed the target consisting of a polystyrene (PS) shell, a fill tube and a conical laser guide. At first, liquid fuel was fed into the shell and existed around the conical laser guide because the surface tension of the fuel must cause it. Then, it was solidified. The laser light provided a heat source to the conical laser guide so that the solid fuel was moved to the other interior of the shell. This process resulted in missing solid fuel around the conical laser guide. To fill the vacant space, liquid fuel was added as temperature was raised to the melting point. After the liquid fuel addition, temperature was lowered to the solidification point again. During this process, most of the solid fuel could survive.
Targets for heterogeneous transmutation of americium are composed of a support material, the inert matrix and of an americium oxide compound: AmO{sub 2-x} or Am{sub 2}O{sub 3}. In parallel to the studies using americium, simulated compounds of americium oxide, chosen amongst lanthanide oxides, are used. The selection of these compounds is based on theoretical, physical and crystallochemical considerations. In order to assess the influence of impurities composed of lanthanide oxides, resulting from the separation process, on the physical and chemical properties of such a target, synthesis of oxide powders containing impurities associated with the simulated americium oxide, characterizations, crystallographic studies and sodium compatibility tests have been performed. (author)
We have studied L x-rays from 64 MeV iodine projectile in collision with various gas targets, Z_2 #18, do not arise from selective M subshell vacancy population, has been conclusively established by the observations by Datz et al (1971) and by Saha et al (1996) that the measured intensity ratio of the Ll and L#alpha# lines, which arise because of transitions from different M subshells into the same L, subshell, does not show any periodic behaviour with Z, but stays rather constant. Differences in the measured L#beta#_1/L#alpha# intensity ratio of iodine with 7"+ and 24"+ charge states impinging on Kr target established the minor role of the electrons in the N shell of the projectile in the x-ray production mechanism. (author)
Pulsed atomic beams produced in vacuum by laser induced ablation from a lithium target are analyzed by laser induced fluorescence (LIF). The 1-mixing processes induced in the n = 9, 10 Li Rydberg states by collisions with CO_2 molecules illustrate the application of the method. Resolution is limited by the 1 mm diameter of the probe laser beam. Combining LIF and absorption measurements gives n_L_i as a function of time at various distances from the target surface. The investigation of the Li-C0_2 1-mixing process in a heat pipe oven proved impossible due to the high reactivity of Li with C0_2. This problem was solved by renewing the Li atoms at each laser shot. Values obtained for n = 9, n = 10 are k = 17 x 10"-"8 and 15 x 10"-"8 cc/sec, respectively.
Heavy ion irradiation on tantalum metal target with 57 MeV {sup 11}B{sup 4+} leads to the production of no-carrier-added radioisotopes of platinum, {sup 187,188}Pt and iridium, {sup 187,188}Ir in the matrix, which have been effectively separated from the bulk target and from each other with suitable anion exchangers employing liquid-liquid extraction (LLX). Also {sup 188,189}Pt and {sup 188,189}Ir radionuclides have been produced, from their short-lived precursors {sup 188,189}Au, in {sup 12}C{sup 6+} irradiated tantalum matrix. Gamma-spectroscopy has been utilised to determine the production, extent of separation and purity of the radiotracers at different stages of the experiment. (orig.)
TiH{sub 2} and TiD{sub 2} thick targets were bombarded with 100 to 200 keV protons. Evidence for nuclear reactions was obtained by means of a surface barrier particle detector. Proton irradiation of TiD{sub 2} produced the following observations: {alpha} particle emission identified as (p, {alpha}) reactions from {sup 11}B and {sup 7}Li impurities in the target at ppm concentrations; and {approx}3 MeV proton and {approx}1 MeV triton emission from secondary D-D reactions caused by elastic scattering of the primary proton with a target deuteron. A 3.9 MeV {alpha} particle peak measured by others was not observed. (author)
Linearly polarized laser radiation accelerates electrons to very high velocities and these electron form a sheath layer on the rear side of thin targets where preferentially protons are accelerated. When mass-limited targets are used, the lateral transport of the absorbed laser energy is reduced and the accelerating field is enhanced. For targets consisting of two ion species, heavier ions facilitate formation of quasi-monoenergetic bunch of lighter ions. For circularly polarized light, fast electron production is suppressed by the absence of the oscillatory component of the ponderomotive force. Ions are accelerated on the front side by the separation field and very thin foil can be accelerated as one massive quasi-neutral block. As all ion species acquire the same velocity, this acceleration mechanism is preferred for heavier ions.
The present work summarizes efforts on the simulation of natural convection cooling within the IFMIF target and test cell. The simulations have been performed with the STAR-CD code using the k-#omega# high-Reynolds number turbulence model. A dedicated thermohydraulic model has been devised including Lithium loop components. Nuclear heat production has been calculated by the Monte-Carlo code McDeLicious for different parts of the target and test cell walls and was used as input for the STAR-CD simulations. Helium atmospheres at several pressures from 0.1 to 10"-"5 MPa have been investigated. In order to limit the maximum temperature of the concrete walls to 80 deg. C it was necessary to add thermal insulation layers to the hot Lithium loop surfaces and a conceptual system of two cooling layers in different depths of the concrete walls.
The penumbra of the profile function describing the nuclear collisions of relativistic heavy ions is related to the cross section for their producing a specific target-nucleus #gamma#-ray, sigmasub(#gamma#). The analysis assumes that the diffuse-edge diffraction model suffices to calculate the inelastic cross sections to the particle-stable states of the target nucleus. When the deformation lengths, deltasub(L) = #beta#sub(L)R, characterizing all important excitations are available from other experiments and the #gamma#-branching of these states is also known, the only unknown quantity determining sigmasub(#gamma#) is found to be the ratio of the diffuseness parameter of the profile function, d, to its radius, R. The most reliably determined values of d/R, for the target "4"0Ca, imply a rather wide penumbra, consistent with microscopic calculations. (orig.).
This paper presents a study involving prediction of a complicated maneuvering target, with the aim of improving the tracking performance of a fire control system (FCS). In this study, we predict the position of a complicated maneuvering target 5 s in advance using the information up to the current time. Because of the large error caused by the complicated maneuvers and the long prediction time interval, the mechanical system of the fire control system will take a heavy load. In order to cope with this problem, several approaches to decreasing the prediction error have been proposed including the prediction algorithms based on the multiple model(MM) filter, interacting multiple model (IMM) filter, and variable dimension with input estimation (VDIE) filter. Finally, comparative simulation re...
The launch of the first spaceborne hyperspectral instrument, Hyperion, in 2000 has provoked further research into its capabilities with regard to mineral exploration. Our study in the remote, mountainous region of Pulang, China employed a two-step progressive approach, first to locate target areas characterized by hydrothermal mineral alteration, using the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), and secondly, to attempt detailed mineral mapping using Hyperion. The preliminary target detection involved principal components and broad-band spectral analysis and led to the detection of two target areas characterized by argillic alteration, iron-oxide- and sulphate-bearing minerals. A focused hyperspectral study followed using Spectral Angle Mapper (SAM) and Mixt...
In simulations with high radiated power fractions, it is possible to produce the drop in ion current to the divertor targets typical of detached plasmas. Despite the fact that these experiments are performed on beryllium target tiles, radiation from deuterium and beryllium cannot account for the measured power losses. The neutral deuterium levels in the SOL in these plasmas are higher than the model predicts. This may be due to leakage from the divertor or to additional wall sources related to the non-steady nature of these plasmas. In contrast, a surprisingly high level of carbon is present in these discharges; higher even than would be predicted are the divertor target tiles pure carbon. This level may well be large enough to produce the measured radiation. (authors). 6 refs., 2 figs., 1 tab.
Comparisons of calculated neutron yield distributions from #alpha#-particle induced reactions on thick targets are made with measured data to analyze the initial reaction process in the framework of the exciton (hybrid) model code ALICE91 (M. Blann, Lawrence Livermore National Laboratory Report UCID 19614, 1982). We have considered two reaction mechanisms: dissolution of the #alpha# in the nuclear field, and preequilibrium processes initiated by #alpha#-nucleon collisions. Both these processes seem to contribute to the emitted neutron spectra in varying proportions depending on the incident #alpha# energy and possibly on the target nucleus. Contributions from other processes appear to be non-negligible.
A combined numerical and theoretical study is conducted herein on the penetration of semi-infinite targets by jacketed rods with different r"j"0/r"c"0 ratios where r"j"0 and r"c"0 are the radii of the jacket and the core, respectively. The numerical results show that for smaller r"j"0/r"c"0 ratios the u-v relationship changes only a little compared to that of unitary long rod penetrator of the same core material, hence, the u-v relationship of unitary (homogeneous) long rod penetration is also applicable for jacketed rod penetration. Model for cratering in semi-infinite targets by jacketed rods is then suggested by using the laws of conversation of mass, momentum and energy, together with the u-v relationship of unitary (homogeneous) long rod penetration and an analytical model for predict...
AbstractThe optimal definition of the size, shape and location of gross tumour volume is one of the most important steps in the planning of radiation therapy, and necessitates a proper...Full Text Available
Effector proteins expressed in the esophageal gland cells of cyst nematodes are delivered into plant cells through a hollow, protrusible stylet. Although evidence indicates that effector proteins function...Full Text Available
The substantia nigra pars reticulata (SNR) represents an endogenous seizure suppressing system, which may be targeted to develop treatments for generalized or multifocal epilepsies. This review summarizes...Full Text Available
Three-dimensional dynamics of a compact toroid (CT) plasmoid, which is injected into a magnetized target plasma region is investigated by using magnetohydrodynamic (MHD) numerical simulations. It is found that the process of the CT penetration into this region is much more complicated than what has been analyzed so far by using a conducting sphere (CS) model. The injected CT suffers from a tilting instability, which grows with the similar time scale as the CT penetration. The instability is accompanied by magnetic reconnection between the CT magnetic field and the target magnetic field, which disrupts the magnetic configuration of the CT. Magnetic reconnection plays a role to supply the high density plasma initially confined in the CT magnetic field into the target region. Also, the penetration depth of the CT high density plasma is examined. It is shown to be shorter than that estimated from the CS model. The CT high ...
BackgroundPCR amplification for the detection of pathogens in biological material is generally considered a rapid and informative diagnostic technique. Invasive Salmonella...Full Text Available
Hypoxia inducible factor-1 (HIF-1) promotes tumor cell adaptation to microenvironmental stress. HIF-1 is up-regulated in irradiated tumors and serves as a promising target for radiosensitization....Full Text Available
Lists of reportable conditions and case definitions are important tools for epidemiologic surveillance. As part of an initiative to encourage occupational disease surveillance systems linked to intervention...Full Text Available
None of the materials presently in common use for polarized proton targets has a pure carbon nuclear background. The alcohols and diols contain some oxygen, and the ammonia and amine-based materials contain nitrogen and/or other noncarbon species. In the latter cases the noncarbon nuclei are measurably polarized as a concomitant of the process used to polarize the hydrogen nuclei. The relative simplicity of a pure carbon background would be advantageous for most types of scattering experiments and perhaps crucial for some. In addition to simplifying the kinematics of background events, pure carbon is relatively easy to prepare as a dummy'' target for background subtraction. Also, in such a target material, [sup 13]C-enrichment would yield a clean polarized [sup 13]C material. In this note I explore the possibilities for such materials, touching upon only what I consider to be the ...
The target of rapamycin (TOR) pathway regulates cell growth and aging in various organisms. In Saccharomyces cerevisiae, silent information regulator 2 (Sir2) modulates cellular senescence. Moreover,...Full Text Available
BackgroundPersonal health records (PHRs) provide patients with access to personal health information (PHI) and targeted education. The use of PHRs has the potential to improve a...Full Text Available
Monogenic autoinflammatory diseases encompass a distinct and growing clinical entity of multisystem inflammatory diseases with known genetic defects in the innate immune system. The diseases...Full Text Available
p53 plays a critical role in tumor suppression. As a transcription factor, in response to stress signals, p53 regulates its target genes and initiates stress responses, including cell cycle arrest,...Full Text Available
EOS Technologies has been commissioned to design and build a unique 2.4m astronomical telescope for the Magdalena Ridge Observatory. This telescope utilizes a high quality primary mirror and cell from a now decommissioned military application. This paper describes the project and gives an overview of the telescope design. The Magdalena Ridge Observatory (MRO) 2.4 meter telescope will be primarily utilized to observe, track, and characterize solar system astronomical targets, Earth satellites, space vehicles, and terrestrial military targets. The telescope's rapid tracking (slew rates are 10o/sec) will allow it to move to any target and acquire data within one minute of receipt of notice. In this way, the telescope will be used to capitalize on targets of opportunity that occur in asteroid studies (e.g., Near Earth Objects) and in astrophysics, such as gamma ray bursts and other transient phenomena. ...
BackgroundCharacterizing infectious disease burden in Africa is important for prioritizing and targeting limited resources for curative and preventive services and monitoring the...Full Text Available
The p53 tumour suppressor plays a pivotal role in the prevention of oncogenic transformation. Cancers frequently evade the potent antitumour surveillance mechanisms of p53 through mutation of the TP53...Full Text Available
Syndrome X is a combination or co-occurrence of several known cardiovascular risk factors (including central obesity, dyslipidemias, fatty liver disease, hyperinsulinemia, insulin resistance,...Full Text Available
The development of new methods for gene addition to mammalian genomes is necessary to overcome the limitations of conventional genetic engineering strategies. Although a variety of DNA-modifying enzymes...Full Text Available
We investigate a method for gene delivery to vascular smooth muscle cells using ultrasound triggered delivery of plasmid DNA from electrostatically coupled cationic microbubbles. Microbubbles...Full Text Available
Immunotoxicity encompasses both reduced and heightened immune function. Diverse chemicals can impair functioning of the immune system. Both monographs and books have been devoted to detailed descriptions...Full Text Available
Systematics of neutron capture radiative width were studied in the target element range from Th to Cm. Reduced radiative widths were analyzed with a simple radiative width formula based on E1 transition. Average radiative width is presented with the standard deviation of 15%. (author)
Atg4 cysteine proteases (autophagins) play crucial roles in autophagy by proteolytic activation of Atg8 paralogs for targeting to autophagic vesicles by lipid conjugation, as well as in subsequent deconjugation...Full Text Available
We have synthesized a novel stable precursor, saligenin phosphorotrichloridate, which, on reaction with N-monobiotinyldiamines, generates a series of biotinylated covalent inhibitors of serine esterases....Full Text Available
SUMMARYThe cytolytic activity of natural killer (NK) cells is regulated by inhibitory receptors that detect the absence of self molecules on target cells. Structural studies of...Full Text Available
Purpose: This paper reviews and reassesses the internationally accepted niches or ‘targets’ in bone marrow that are sensitive to the induction of leukaemia and primary...Full Text Available
MicroRNAs (miRNAs) are short non-coding RNAs that play a central role in regulation of gene expression by binding to target genes. Many miRNAs were associated with the function of the central nervous...Full Text Available
PrefaceCardiovascular effects of epoxyeicosatrienoic acids (EETs) include vasodilation, vascular smooth muscle cell anti-migratory actions, and anti-inflammatory actions. These...Full Text Available
SummarySoluble epoxide hydrolase (sEH) is a key enzyme in the metabolic conversion and degradation of P450 eicosanoids called epoxyeicosatrienoic acids (EETs). Genetic variations...Full Text Available
The intracellular bioavailability of lead (Pb) at low dosage levels in major target organs such as the kidney and brain appears to be largely determined by complexation with a group of low molecular...Full Text Available
A vast amount of circumstantial evidence implicates oxygen-derived free radicals (especially, superoxide and hydroxyl radical) and high-energy oxidants [such as peroxynitrite (OONO−)]...Full Text Available
Convection-enhanced delivery (CED) has emerged as a promising method of targeted drug-delivery for treating central nervous system (CNS) disorders, but the influence of brain structure on infusate...Full Text Available
URA5 genes encode orotidine-5′-monophosphate pyrophosphorylase (OMPpase), an enzyme involved in pyrimidine biosynthesis. We cloned the Histoplasma capsulatum URA5...Full Text Available
The polymerase chain reaction (PCR) was investigated as a means of diagnosing Mycoplasma pneumoniae infections. The target DNA sequence was a 375-bp segment of the P1 virulence protein. This DNA segment...Full Text Available
Target of rapamycin (TOR) kinases control cell growth through two functionally distinct multiprotein complexes. TOR complex 1 (TORC1) controls temporal cell growth and is sensitive to rapamycin, whereas...Full Text Available
The Gordon Research Conference (GRC) on ROCK DEFORMATION was held at II Ciocco from 5/19/02 thru 5/24/02. Emphasis was placed on current unpublished research and discussion of the future target areas in this field.
Some of most used indicators in marine ecology are nucleic acid-derived indices. They can be divided by target levels in three groups: 1) at the organism level as ecophysiologic indicators, indicators...Full Text Available
Breast cancer is a progressive and potentially fatal disease that affects women of all ages. Like all progressive diseases, early and reliable diagnosis is the key for successful treatment and annihilation....Full Text Available
Thiobenzamide (TB) is a potent hepatotoxin in rats, causing dose-dependent hyperbilirubinemia, steatosis, and centrolobular necrosis. These effects arise subsequent to and appear to result from...Full Text Available
It has been sixty years since the Millers first described the covalent binding of carcinogens to tissue proteins. Protein covalent binding was gradually overshadowed by the emergence of DNA...Full Text Available
The parathyroid hormone receptor (PTHR) is a class B G protein-coupled receptor that plays critical roles in bone and mineral ion metabolism. Ligand binding to the PTHR involves interactions to both...Full Text Available
The "6"2Zn-"6"2Cu generator system is one of the few which yield a pure positron emitting daughter. The authors have developed a method for the preparation of this generator system following 32 MeV #alpha# particle bombardment of nickel targets. The chemical processing involves two stages: first a hydrous zirconium oxide column is used at pH 4-5 to separate the zinc and copper activities produced in the target nickel, and secondly, a conventional anion exchange column is used to retain the "6"2Zn and remove all copper activities in 2M HCl. This column serves as the "6"2Cu generator which will yield pure "6"2Cu repeatedly, free from "6"2Zn and other impurities, in a mixture of HCl and NaCl. A method is outlined also to obtain a solution of "6"2Zn using the hydrous zirconium oxide (HZO) column. "6"1Cu can be prepared as a by-product in the above procedure, but a method for the preparation of "6"1Cu alone using an 18 MeV #alpha# particle beam on a ...
Epidermal growth factor receptor (EGFR) related therapies – mainly tyrosine kinase inhibitors (TKIs) such as erlotinib and gefitinib, but also monoclonal antibodies targeting EGFR, for example,...Full Text Available
Rapamycin inhibits the mTOR (target of rapamycin) pathway and extends lifespan in multiple species. The tuberous sclerosis complex (TSC) protein is a negative regulator of mTOR. In humans, loss of the...Full Text Available
Previous studies in several different trigeminal nerve injury/inflammation models indicated that the hyperexcitability of primary afferent neurons contributes to the pain pathway underlying mechanical...Full Text Available
The A(..pi../sup +/,/sup 3/He)B reaction near threshold is studied in a model where the pion is absorbed by an /sup 4/He constituent of the target nucleus. The predictions of this model using harmonic oscillator cluster wave functions agree semi-quantitatively with the experimental data on the inverse reaction.
Idiopathic pulmonary fibrosis (IPF) is a progressive disease with poor survival. The identification of therapeutic targets is essential to improving outcomes. Previous studies found that expression...Full Text Available
Patients with pancreatic cancer normally present with advanced disease that is lethal and notoriously difficult to treat. Survival has not improved dramatically, despite routine use of chemotherapy...Full Text Available
BackgroundThe genus Vibrio is a diverse group of Gram-negative bacteria comprised of 74 species. Furthermore, the genus has and is expected to continue expanding...Full Text Available
In order to optimize the production of "2"0"1Tl and "6"7Ga using the (p, xn) reactions on enriched "2"0"3Tl and "6"8Zn targets we established a new set of cross section curves for the most relevant reactions. Target stacks made of up to 15 thin (50 #mu#m) natural Tl or Zn foils interleaved with brass degradation foils were irradiated with incident proton energies from 42 to 10 MeV in overlapping experiments. Yields for "2"0"0","2"0"1","2"0"2"m","2"0"3","2"0"4"mPB and "6"6","6"7","6"8Ga were computed from measured #gamma# emission rates. Where possible, cross section curves for the nuclear reactions involved were computed. Thick target yields and contamination ratios for enriched targets were derived and show good agreement with results from actual production runs. (orig.).
Hypothyroidism and thyrotoxicosis are each associated with an increased risk of fracture. Although thyroxine (T4) is the predominant circulating thyroid hormone, target cell responses are determined...Full Text Available
BackgroundStem cell characteristics are an important feature of human cancer cells and play a major role in the therapy resistance of tumours. Strategies to target cancer stem cells...Full Text Available
Numerous transmethylation reactions are required for normal plant growth and development. S-adenosylhomocysteine hydrolase (SAHH) and adenosine kinase (ADK) act coordinately to recycle the by-product of these reactions, S-adenosylhomocysteine (SAH) that would otherwise competitively inhibit methyltransferase (MT) activities. Here, we report on investigations to understand how the SAH produced in the nucleus is metabolized by SAHH and ADK. Localization analyses using green fluorescent fusion proteins demonstrated that both enzymes are capable of localizing to the cytoplasm and the nucleus, although no obvious nuclear localization signal was found in their sequences. Deletion analysis revealed that a 41-amino-acid segment of SAHH (Gly(150)-Lys(190)) is required for nuclear targeting of this enzyme. This segment is surface exposed, shows unique sequence conservation patterns in plant SAHHs, and possesses additional features of protein-protein interaction motifs. ADK ...
Nicotine is the main psychoactive ingredient in tobacco and its rewarding effects are considered primarily responsible for persistent tobacco smoking and relapse. Although dopamine has been extensively...Full Text Available
Treating brain tumors using inhibitors of angiogenesis is extensively researched and tested in clinical trials. Although anti-angiogenic treatment holds a great potential for treating primary and secondary...Full Text Available
The 37/67-kd laminin receptor, LAMR, is a multifunctional protein that associates with the 40S ribosomal subunit and also localizes to the cell membrane to interact with the extracellular matrix. LAMR...Full Text Available
BackgroundIntrafractional motion results in local over- and under-dosage in particle therapy with a scanned beam. Scanned beam delivery offers the possibility to compensate target...Full Text Available
The sequence-dependent structural variability and conformational dynamics of DNA play pivotal roles in many biological milieus, such as in the site-specific binding of transcription factors to target...Full Text Available
MicroRNAs (miRNAs) are endogenously encoded small noncoding RNAs, derived by processing of short RNA hairpins, that can inhibit the translation of mRNAs bearing partially complementary target sequences....Full Text Available
BackgroundCD26 (dipeptidyl peptidase IV, DPPIV) is a 110 kDa surface glycoprotein expressed in most normal tissues, and is a potential novel therapeutic target for selected cancers....Full Text Available
The National Spallation Neutron Source (NSNS), in which neutrons are generated by bombarding a liquid mercury target with 1 GeV protons, will place extraordinary demands on materials performance. The target structural material will operate in an aggressive environment, subject to intense fluxes of high energy protons, neutrons, and other particles, while exposed to liquid mercury and to water. Components that require special consideration include the Hg liquid target container and protective shroud, beam windows, support structures, moderator containers, and beam tubes. In response to these demands a materials R and D program has been developed for the NSNS that includes: selection of materials; calculations of radiation damage; irradiations, post irradiation testing, and characterization; compatibility testing and characterization; design and implementation of a plan for monitoring of materials performance in service; and ...
64Cu (T1/2=12.7h, ?- decay: 40%, ?+ decay: 19%, E.C. decay: 41%) is one of the most useful radioisotope in the nuclear medicine due to its multiple decay mode and the intermediate half-life. Several nuclear reaction, i.e., 64Ni(p,n)64Cu, 68Zn(p,?n)64Cu and 64Ni(d,2n)64Cu have been investigated for production. The highest could be obtained with proton irradiation on the enriched 64Ni target. For mass and routine production, the 64Ni target fabrication using electroplating, the reliable chemical separation of 64Cu from the irradiated 64Ni target and the effective recovery process for the recycling of very expensive enriched material ($20,000/g) and so forth are absolutely necessary to be established. In this work, we report our mass production method of 64Cu with 64Ni and Cyclone-30 accelerator
Inducible gene expression appears to be an essential event that couples light to entrainment of the master mammalian circadian clock located in the suprachiasmatic nucleus (SCN) of the hypothalamus....Full Text Available
BackgroundGene expression profiling and the analysis of protein-protein interaction (PPI) networks may support the identification of disease bio-markers and potential drug targets....Full Text Available
Epithelial-mesenchymal transition (EMT), a switch of polarized epithelial cells to a migratory, fibroblastoid phenotype, is considered a key process driving tumor cell invasiveness and metastasis....Full Text Available
We have characterized the kinetic response of gene targets throughout the murine genome to transcriptional modulation by the glucocorticoid receptor (GR). In contrast to a model in which multiple genes...Full Text Available
Given the high prevalence of overweight and low levels of physical activity among children, a better understanding of physical activity behaviour is an important step in intervention planning. This...Full Text Available
Gastrin-releasing peptide receptor (GRPR), a member of the G protein-coupled receptor superfamily, has been utilized for receptor-mediated targeting of imaging and therapeutic agents; here we extend...Full Text Available
As the result of genetic alterations and tumor hypoxia, many cancer cells avidly take up glucose and generate lactate through lactate dehydrogenase A (LDHA), which is encoded by a target gene of c-Myc...Full Text Available
Myosin phosphatase target subunit 1 (MYPT1) is the regulatory subunit of myosin light chain phosphatase (MLCP). It plays a critical role in vasodilatation induced by cGMP-elevating agents such as nitric...Full Text Available
To define the import pathway for apoiso-1-cytochrome c in vivo, the coding region for bacterial chloramphenicol acetyltransferase (CAT) or yeast copper metallothionein (CuMT) was fused to the carboxy...Full Text Available
A detailed molecular characterization of nuclear mRNA export will require an in vitro system, allowing a biochemical reconstitution of transport. To this end, an mRNA export assay has...Full Text Available
An immunoglobulin Mk monoclonal (F8IVE9) antibody raised against oat (Avena sativa cv Garry) root homogenate has been produced and characterized. The predominant target...Full Text Available
Neuropilin-1 (NRP1) acts as a co-receptor for class 3 semaphorins and vascular endothelial growth factor and is an attractive angiogenesis target for cancer therapy. In addition to the transmembrane...Full Text Available
BackgroundASCL1 role in pancreatic endocrine tumourigenesis has not been established. Recently it was suggested that ASCL1 negatively controls expression of the...Full Text Available
BackgroundIn chordates, retinoid metabolism is an important target of short-chain dehydrogenases/reductases (SDRs). It is not known whether SDRs play a role in retinoid...Full Text Available
... 154. By way of comparison, the aquatic weed Hygrophila polysperma (Roxb.) T. Anderson, a potential target for biological ... L. Sutton. 2000. Is the aquatic weed hygrophila, Hygrophila polysperma (Polemon...
SUMMARYDendritic cells (DCs) in mucosal surfaces are early targets for human immunodeficiency virus-1 (HIV-1). DCs mount rapid and robust immune responses upon pathogen encounter....Full Text Available
BackgroundPolyadenylation of RNA has a decisive influence on RNA stability. Depending on the organisms or subcellular compartment, it either enhances transcript stability or targets...Full Text Available
Individuals from families recruited for the Long Life Family Study (LLFS) (n= 4559) were examined and compared to individuals from other cohorts to determine whether the recruitment targeting longevity...Full Text Available
BackgroundCalcium homeostasis is a known target of several environmental toxicants including lead and mercury.ObjectiveOur goal was to determine...Full Text Available
Chemical genetics is an emerging approach to investigate the biology of host-pathogen interactions. We screened several inhibitors of ATP-dependent DNA motors and detected the gyrase B inhibitor coumermycin...Full Text Available
Jan 20, 1995 ... Jenn-Air dowedraft cooktop, staintess steel, coil. $75; telephone ans mach, $25. Eric, x31917. $295; President & First Lady premier plus ...
Recently, we demonstrated that the central ghrelin signalling system, involving the ghrelin receptor (GHS-R1A), is important for alcohol reinforcement. Ghrelin targets a key mesolimbic circuit involved...Full Text Available
SummaryBlastomycosis is a serious and potentially fatal infection by the thermally dimorphic fungus Blastomyces dermatitidis. PCR assays targeting the BAD-1 virulence...Full Text Available
Optimal sample handling techniques for tissue preparation and storage, RNA extraction and quantification, and target gene detection are crucial for reliable gene expression analysis. Methods...Full Text Available
The cancer preventive action of (−)-epigallocatechin gallate (EGCG), found in green tea, is strongly supported by epidemiology and laboratory research data. However, the mechanism by...Full Text Available
Amphibian population declines and sudden species' extinctions began to be noted at the beginning of the 1980s. Understanding the causes of the losses is hampered by our poor knowledge of the amphibian...Full Text Available
In recent years, the food and beverage industry in the US has viewed children and adolescents as a major market force. As a result, children and adolescents are now the target of intense and specialized...Full Text Available
The heterogeneity of metastatic breast cancer mandates the need to select therapies taking into account tumor and patient characteristics. Chemotherapy is indicated in the palliative setting especially...Full Text Available
There is an increasing interest in using radioisotopes of rare earth elements for internal radiotherapy and for imaging in nuclear medicine. {sup 177}Lu is one of the promising radionuclides. This article reports on the first measurements of the excitation function for the production of {sup 177}Lu with proton-beam energies up to 17 MeV on natural hafnium targets. The experimental cross sections for the reaction {sup nat}Hf(p,x){sup 177}Lu were obtained by the activation of a stacked-foil target and subsequent gamma spectrometry. Theoretical cross sections were calculated up to 35 MeV with the EMPIRE nuclear reaction model code. The measured and calculated cross sections were used for deriving the thick-target yields and for estimating the production of other nuclides than {sup 177}Lu. Measured production cross sections of {sup 175,176,177,178}Ta on the same target are also presented.
There is an increasing interest in using radioisotopes of rare earth elements for internal radiotherapy and for imaging in nuclear medicine. "1"7"7Lu is one of the promising radionuclides. This article reports on the first measurements of the excitation function for the production of "1"7"7Lu with proton-beam energies up to 17 MeV on natural hafnium targets. The experimental cross sections for the reaction "n"a"tHf(p,x)"1"7"7Lu were obtained by the activation of a stacked-foil target and subsequent gamma spectrometry. Theoretical cross sections were calculated up to 35 MeV with the EMPIRE nuclear reaction model code. The measured and calculated cross sections were used for deriving the thick-target yields and for estimating the production of other nuclides than "1"7"7Lu. Measured production cross sections of "1"7"5","1"7"6","1"7"7","1"7"8Ta on the same target are also presented.
Phonological density refers to the number of words that can be generated by replacing a phoneme in a target word with another phoneme in the same position. Although the precise nature of the...Full Text Available
Abstract in english A long-standing debate in the literature is whether attention can form two or more independent spatial foci in addition to the well-known unique spatial focus. There is evidence that voluntary visual attention divides in space. The possibility that this also occurs for automatic visual attention was investigated here. Thirty-six female volunteers were tested. In each trial, a prime stimulus was presented in the left or right visual hemifield. This stimulus was characteriz (more) ed by the blinking of a superior, middle or inferior ring, the blinking of all these rings, or the blinking of the superior and inferior rings. A target stimulus to which the volunteer should respond with the same side hand or a target stimulus to which she should not respond was presented 100 ms later in a primed location, a location between two primed locations or a location in the contralateral hemifield. Reaction time to the positive ...
TSH receptor (TSHR) plays a central role in regulating thyroid function and is targeted by IgGs in Graves’ disease (GD-IgG). Whether TSHR is involved in the pathogenesis of thyroid associated...Full Text Available
The technology of minor actinide recycling in fast reactors has been discussed. In CEA, the feasibility study on Am once-through recycling in Phenix core with the moderated target subassemblies (S/As) has been performed. In this report, the evaluation of the heterogeneity effect on the moderated target S/As is described. It was evaluated by the calculation with the continuous energy Monte-Carlo code, MVP, because the accuracy of the deterministic method for the moderated target S/As is unknown. The reaction rates of four isotopes (Am-241, Am-242, Am242m and Am-243) calculated with the heterogeneous model and the homogeneous one were compared. These four isotopes play the important role in Am incineration. It is seen that the homogeneous model overestimates the reaction rates of Am-241 and Am-243 by 4 - 13%, and underestimates those of Am-242 and Am-242m by 13 - 23%. Further investigation made it clear that the ...
BackgroundAntigen sparing and cross-protective immunity are regarded as crucial in pandemic influenza vaccine development. Both targets can be achieved by adjuvantation strategy...Full Text Available
Tantalum and tantalum-based thin films have gained precedence as the diffusion barrier for copper interconnects used in the latest generation of integrated circuits (ICs). The paper presents insight and observations on the covariance of texture and grain size of wrought tantalum sputtering targets and their influence on sputtering performance. Previous studies involving deposition trials of tantalum targets of varying metallurgical character had demonstrated that both grain size and textural homogeneity is critical for assuring reliable sputtering performance of tantalum. Subsequently, a model had been proposed to prescribe how localized texture bands and orientation clusters in tantalum are effectively resistant to sputter erosion. In this paper, results of atomic force microscopy (AFM) and orientation imaging microscopy (OIM{sup TM}) analyses on the eroded surface of a tantalum sputtering target are presented. Initial ...
Short-hairpin RNA (shRNA)–mediated gene knockdown is a powerful tool for targeted gene silencing and an emerging novel therapeutic strategy. Recent publications, however, reported unexpected...Full Text Available
The Tetrahymena thermophila origin recognition complex (ORC) contains an integral RNA subunit, 26T RNA, which confers specificity to the amplified ribosomal DNA (rDNA) origin by base...Full Text Available
The p21-activated kinases (PAKs), immediate downstream effectors of the small G-proteins of the Rac/cdc42 family, are critical mediators of signaling pathways regulating cellular behaviors and...Full Text Available
This R and D project is planed to supply domestic demands of Mo-99 through fission route, and consequently this project will be expected to rise up utilization of HANARO and KAERI's capability for marketing extension into domestic and oversea radiopharmaceutical market. HEU and LEU target types are decided and designed for fission Mo-99 production in domestic. Experimental study of target fabrication technology was performed and developed processing equipments. And conceptual design of target loading/unloading in/from HANARO device are performed. Tracer test of Mo-99 separation and purification process was performed, test results reach to Mo-99 recovery yield above 80% and decontamination factor above 1600. Combined Mo-99 separation and purification process was decided for hot test scheduled from next year, and performance test was performed. Conceptual design for modification of existing hot cell for fission Mo-99 ...
Several Bartonella species have now been implicated as human pathogens. The recovery of these fastidious organisms in the clinical microbiology laboratory remains difficult, and current...Full Text Available
The identification of the protein targets for dengue virus-specific T lymphocytes may be useful for planning the development of subunit vaccines against dengue. We studied the recognition by murine...Full Text Available
We calculate mass spectrum of CHS model deformed by an exactly marginal operator, and find that there are tachyons which are not localized in the target space. Similar deformation is discussed in another CFT which corresponds to separated NS5-branes. A condensation of the tachyons is briefly argued.
The syntheses and applications of two metallointercalators, Rh(bpy)2(chrysi)3+ and Rh(bpy)2(phzi)3+, that target single base mismatches in DNA are...Full Text Available
Determine the degree to which different precautionary themes are dominant in various target populations and how these themes are acquired. Assess cultural signals of potential danger: are there different kinds of potential danger in different cultures. Do...
ObjectiveFish consumption advisories are issued to warn the public of possible toxicological threats from consuming certain fish species. Although developing fetuses and children...Full Text Available
After emergence, adult flies and other insects select a suitable perch and expand their wings. Wing expansion is governed by the hormone bursicon and can be delayed under adverse environmental...Full Text Available
Cytokinins are distributed through the vascular system and trigger responses of target cells via receptor-mediated signal transduction. Perception and transduction of the signal can occur at the plasma...Full Text Available
BackgroundAs the first pathway-specific enzyme in carotenoid biosynthesis, phytoene synthase (PSY) is a prime regulatory target. This includes a number of biotechnological approaches...Full Text Available
The antitumor agent camptothecin targets DNA topoisomerase I by reversibly stabilizing a covalent enzyme-DNA intermediate. The subsequent collision of DNA replication forks with these drug-enzyme-DNA...Full Text Available
A simple beam-forming system is described for the electrostatic accelerator of the Scientific-Research Institute of Nuclear Physics of Moscow State University. The system allows the beam to be focused on targets at various distances for a conductor potential of from 1 to 4 MV and beam currents of up to 35 #mu# A.
This study used a PCR-based approach targeting 16S rRNA gene fragments to determine the occurrence and association of the three bovine digital dermatitis (BDD) treponeme phylogroups within lesions found...Full Text Available
A goal of our research is to identify biochemical factors that underlie the susceptibility of bone marrow cell populations to benzene metabolites so as to develop a mechanistically based chemoprotective...Full Text Available
BackgroundFormation of site specific genomic double strand breaks (DSBs), induced by the expression of a pair of engineered zinc-finger nucleases (ZFNs), dramatically increases the...Full Text Available
ObjectiveThis study sought to determine whether differential treatment effects in the targeted mechanisms of change and eating disorder (ED) symptoms are associated...Full Text Available
BackgroundMale infertility is a common cause of reproductive failure in humans. In mice, targeted deletions of the genes coding for FKBP6 or FKBP52, members of the FK506 binding...Full Text Available
Essential in mitosis, the human Kinesin-5 protein is a target for >80 classes of allosteric compounds that bind to a surface-exposed site formed by the L5 loop. Not established is why there...Full Text Available
Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors belonging to the nuclear hormone receptor superfamily. Their discovery in the 1990s provided insights...Full Text Available
SUMMARYATG12, an ubiquitin-like modifier required for macroautophagy, has a single known conjugation target, another autophagy regulator called ATG5. Here, we identify ATG3 as...Full Text Available
As part of the Nondestructive Evaluation Reliability Program sponsored by the US Nuclear Regulatory Commission, the Pacific Northwest Laboratory is developing a method that uses risk-based approaches to establish in-service inspection plans for nuclear power plant components. This method uses probabilistic risk assessment (PRA) results and Failure Modes and Effects Analysis (FEMA) techniques to identify and prioritize the most risk-important systems and components for inspection. The Surry Nuclear Power Station Unit 1 was selected for pilot applications of this method. The specific systems addressed in this report are the reactor pressure vessel, the reactor coolant, the low-pressure injection, and the auxiliary feedwater. The results provide a risk-based ranking of components within these systems and relate the target risk to target failure probability values for individual components. These results will be used to guide the development of ...
A duplex TaqMan real-time RT-PCR assay was developed for the detection of California (CAL) serogroup viruses and Cache Valley virus (CVV), for use in human surveillance. The targets selected...Full Text Available
PurposeTaxanes have effects on angiogenesis causing difficulties in separating biologic effects of chemotherapy from those due to angiogenesis inhibitors. This randomized...Full Text Available
Autophagic adapters including p62/SQSTM1 recognize polyubiquitinated autophagic targets such as toxic protein aggregates. Recently reporting in Molecular Cell, Filimonenko et al. provide evidence...Full Text Available
A Bragg curve counter equipped with an internal production target was developed for the measurements of double-differential cross-sections of fragment production induced by neutrons at energies of tens of MeV. The internal target permitted a large detection solid angle and thus the registration of processes at low production rates. In this specific geometry, the detection solid angle depends on the emission angle and the range of the particle. Therefore the energy, atomic number, and angle of trajectory of the particle have to be taken into account for the determination of the solid angle. For the selection of events with tracks confined within a defined cylindrical volume around the detector axis, a segmented anode was applied. The double-differential cross-sections for neutron-induced production of lithium, beryllium, and boron fragments from a carbon target were measured at 0 deg. for 65 MeV neutrons. The results are in ...
From autumn this year, the FRJ-2 of the Research Center Juelich will be supplying molybdenum targets to the Institut National des Radioelements in Fleurus, Belgium - which deals in medical radio-isotopes worldwide - thus helping to meet the need for technetium-99, which is used in the medical profession for diagnostic purposes because of its favourable radiological characteristics. Technetium-99 is formed as a result of the radioactive decay of molybdenum-99. For many years now, molybdenum has been produced by the irradiation of uranium in research reactors, so that the initiation of molybdenum production in the FRJ-2 is not especially new. What is unusual, however, are the particular peripheral conditions which result from the combination of the irradiation requirements, a predetermined target design and the technical characteristics of the reactor and which necessitated special solutions. This applies especially to the handling of the ...
The chemical separation of carrier-free "2"0"3Pb following deuterium bombardment of a "2"0"3Tl target is described. Coprecipitation from strontium sulphate was used to separate the "2"0"3Pb from a solution of the thallium target in sulphuric acid. The SrSO_4 precipitate was filtered, washed and dissolved in hydrochloric acid, from which "2"0"3Pb was again separated by precipitation on sodium chloride from a strongly acid solution. Advantages of the system are discussed and optimum conditions given. (U.K.).
NIF target diagnostics are being developed to observe and measure the extreme physics of targets irradiated by the 192-beam laser. The response time of target materials can be on the order of 100ps--the time it takes light to travel 3 cm--temperatures more than 100 times hotter than the surface of the sun, and pressures that exceed 109 atmospheres. Optical and x-ray diagnostics were developed and fielded to observe and record the results of the first 4-beam experiments at NIF. Hard and soft x-ray spectra were measured, and time-integrated and gated x-ray images of hydrodynamics experiments were recorded. Optical diagnostics recorded backscatter from the target, and VISAR laser velocimetry measurements were taken of laser-shocked target surfaces. Additional diagnostics are being developed and commissioned to observe and diagnose ignition implosions, including various neutron and ...
High power and particle deposition on target materials are encountered in many applications including magnetic and inertial fusion devices, nuclear and high energy physics applications, and laser and discharge produced plasma devices. Surface and structural damage to plasma-facing components due to the frequent loss of plasma confinement remains a serious problem for the Tokamak reactor concept. The deposited plasma energy causes significant surface erosion, possible structural failure, and frequent plasma contamination.
A simple and rapid procedure was developed for the purification of cyclotron-produced {sup 203}Pb via the {sup 203}Tl(d,2n) {sup 203}Pb reaction. A Pb(II) selective ion-exchange resin, with commercial name Pb Resin from Eichrom Technologies, Inc., was used to purify {sup 203}Pb from the cyclotron-irradiated Tl target with excellent recovery of the enriched Tl target material. The purified {sup 203}Pb was used to radiolabel the monoclonal antibody Herceptin. The in vitro and in vivo properties of the {sup 203}Pb radioimmunoconjugate were evaluated.
Special beam extraction channel is used at INR linac for isotope production. It starts from 160 MeV measuring and matching area of accelerator. This choice of beam extraction enables to direct to the target of isotope complex a proton beam of wide energy range up to 160 MeV. It is important for production of different types of nuclides. The measuring results of proton beam behavior in this region are presented. Required beam forming in 160 MeV measuring and matching area of accelerator and in beam extraction channel is discussed.
The chemical separation of carrier-free /sup 203/Pb following deuterium bombardment of a /sup 203/Tl target is described. Coprecipitation from strontium sulphate was used to separate the /sup 203/Pb from a solution of the thallium target in sulphuric acid. The SrSO/sub 4/ precipitate was filtered, washed and dissolved in hydrochloric acid, from which /sup 203/Pb was again separated by precipitation on sodium chloride from a strongly acid solution. Advantages of the system are discussed and optimum conditions given.
The NuMI proton beam at Fermilab currently delivers 120 GeV protons to the neutrino production target with design beam power capability to 400 kW. Upgrade capability to 700 kW is being prepared, with planning toward delivering 2.3 MW beam provided by the Project X accelerator upgrade plan. We report on the system of beam diagnostics and control used in operation of the NuMI beam. Also considered are the steps to provide a robust system for transport and targeting beam of 2 MW and beyond.
Time delay neural networks trained with the backpropagation algorithm are derived for the gun fire control system to correct the miss distance between a target and the projectiles from the gun. Its performance is compared to optimum linear filter based on minimum mean square error [R.E. Kalman, A new approach to linear filtering and prediction problems, J. Basic Eng. 82D (1960) 35-44.]. The structure of the proposed neural controller is described and performance results are shown.
The first measurement of the pn{yields}d{omega} total cross-section has been achieved at mean excess energies Q{approx}28 and 57 MeV by using a deuterium cluster-jet target. The momentum of the fast deuteron was measured in the ANKE spectrometer at COSY-Juelich and that of the slow ''spectator'' proton (p{sub sp}) from the pd{yields}p{sub sp}d{omega} reaction in a silicon telescope placed close to the target. The cross-sections lie above those measured for pp{yields}pp{omega} but seem to be below theoretical predictions. (orig.)
The uranium target of a gas jet transport system for fission products has been modified by the addition of an aluminum cover foil. The new modification allows fission fragments of low mass to enter a continuous chemistry system while heavier fragments are stopped in the aluminum. The elimination of the heavier homologues allows development of simpler and faster chemical separation procedures. In addition, since the lighter fragments are slowed down by the cover foil a smaller target chamber can be used. This leads to a reduction in system holdup time.
The uranium target of a gas jet transport system for fission products has been modified by the addition of an aluminum cover foil. The new modification allows fission fragments of low mass to enter a continuous chemistry system while heavier fragments are stopped in the aluminum. The elimination of the heavier homologues allows development of simpler and faster chemical separation procedures. In addition, since the lighter fragments are slowed down by the cover foil a smaller target chamber can be used. This leads to a reduction in system holdup time. (orig.).
Experimentally it is shown that a movable grounded metallic plate placed inside a multi-dipole magnetic cage can vary the diffused plasma parameters such as density, plasma potential and electron temperature. Plasma is solely produced in the source section of a double plasma device by a dc hot filament discharge and a low-density plasma is produced in the target section by local ionization of neutral gas by the high energetic electrons coming from the source section. A grounded movable stainless steel plate is inserted in the target section of the device. The floating potential of the plate also changes depending on the position of the plate inside the magnetic cage.
Locked nucleic acid (LNA) is a nucleic acid analogue containing one or more LNA nucleotide monomers with a bicyclic furanose unit locked in an RNA mimicking sugar conformation. This conformational restriction results in unprecedented hybridization affinity towards complementary single stranded RNA and thus, makes LNA uniquely suited for mimicking RNA structures and sequence specific targeting of RNA in vitro or in vivo. The focus of this paper is on LNAantisense, LNA-modified siRNA (siLNA), and detection and analysis of microRNAs by LNA-modified oligonucleotide probes.
Studies of destruction of very-high-n (100targets HF and NH_3 are reported. Analysis of the data using the essentially-free-electron model suggests that, for ultralow electron energies (#approx#80 #mu#eV--1.4 meV), the cross section #sigma#(var-epsilon) for rotationally inelastic scattering of electrons by a polar target varies approximately as 1/var-epsilon, where var-epsilon is the electron energy.
The hot uniform aluminium plasma was produced by irradiating thin aluminium dotted foil smoothly with the 9th 0.53 ?m laser on Shenguang II laser facility. The emitted spectrum was measured from the front and tangential direction of the target with two crystal spectrometers, and the quantitative spectrum from the front of the target was obtained. The state of laser- produced plasma was simulated with the radiation hydrodynamics code MULTI-1D, and the emitted spectrum was calculated with the spectrum code of Collision-Radiation model under the simulated plasma state. The experimental spectrum accords with the simulated one. (authors)
The paper presents experimental investigations of main features of plasma surface interaction and energy transfer to the material surface in dependence on plasma heat loads. The experiments were performed with QSPA repetitive plasma pulses of the duration of 0.25 ms and the energy density up to 2.5 MJ/m2. Surface morphology of the targets exposed to QSPA plasma screams is analyzed. Relative contribution of the Lorentz force and plasma pressure gradient to the resulting surface profile is discussed. development of cracking on the tungsten surface and swelling of the surface are found to be in strong dependence on initial temperature of the target.
Electron beam therapy has often been used for radiation therapy of carcinomas of the buccal mucosa, though side effects, including stomatitis and dermatitis, are known to exist. We experimented using the additional back scatter and transit with the phantom under a lead plate within the irradiation field, in order to better focus the dose on the target volume moreover, we fabricated a mouthpiece fitted with a lead plate shaped to the target volume, and with respect to the influence of the mouthpiece on stomatitis and dermatitis, obtained good clinical results. (author).
Electron beam therapy has often been used for radiation therapy of carcinomas of the buccal mucosa, though side effects, including stomatitis and dermatitis, are known to exist. We experimented using the additional back scatter and transit with the phantom under a lead plate within the irradiation field, in order to better focus the dose on the target volume moreover, we fabricated a mouthpiece fitted with a lead plate shaped to the target volume, and with respect to the influence of the mouthpiece on stomatitis and dermatitis, obtained good clinical results. (author).
In the quest to understand the ultimate nature of WIMPs, we propose the use of a hybrid detection technique: cylinders filled with liquefied noble gasses, acting as targets, are immersed inside a tank of Gd-doped ultra-pure water that provides an active and efficient veto against neutrons. The evaluation of the background rejection capabilities and physics potential of this instrument have been carried out through a full GEANT4 simulation, assuming the detector will be located at the Canfranc underground laboratory (in the Spanish Pyrenees). Our results compare very favourably with existing or planned experiments in the field. This technique is scalable and will allow to reach target masses of few tonnes in the next future.
A new aiming point guidance (APG) law in 3-dimensional space is derived analytically. The guidance law is capable of guiding the missile (interceptor) to a straight collision course with respect to the target. The missile turning rate command proportional to the error angle between the current missile heading and the predicted aim point is calculated based on the predicted target position. Performance of the APG law is numerically evaluated and compared with the proportional navigation guidance (PNG) law. The result of numerical simulation shows that the APG law is superior to the PNG law in terms of miss distance, time of interception and final stage missile turning rate demand.
Conformal radiation therapy represents a considerable and attractive challenge in oncology. Its aim is mainly to improve local control by increasing the dose with an acceptable rate of complications. This work overviews the world literature on this subject. The technical and theoretical requirements are highlighted. These requirements include a precise definition of the target volume by digital imaging (essentially CT scan), but also clear view of the target volume and the organs at risk, a specific collimation of the beam, 3-D dose calculations, optimization procedures, and a rigid immobilization of the patient with verification of his position. Moreover, the clinical applications of conformal radiation therapy are reviewed and discussed. (authors). 80 refs., 1 tab.