WorldWideScience

Sample records for surface buildup scenarios

  1. Mars base buildup scenarios

    International Nuclear Information System (INIS)

    Blacic, J.D.

    1985-01-01

    Two surface base build-up scenarios are presented in order to help visualize the mission and to serve as a basis for trade studies. In the first scenario, direct manned landings on the Martian surface occur early in the missions and scientific investigation is the main driver and rationale. In the second scenario, early development of an infrastructure to exploite the volatile resources of the Martian moons for economic purposes is emphasized. Scientific exploration of the surface is delayed at first, but once begun develops rapidly aided by the presence of a permanently manned orbital station

  2. Effect of surface treatments on radiation buildup in steam generators

    International Nuclear Information System (INIS)

    Asay, R.H.; Pick, M.E.; van Melsen, C.

    1991-11-01

    Test coupons of typical PWR materials of construction were prepared using a number of pretreatments to minimize radiation buildup. The coupons were then exposed to primary coolant at the Doel-2 PWR in Belgium. The exposure periods for the coupons ranged from one to three fuel cycles. After removal from the primary system, doserate and gamma spectroscopy measurements were made to determine the radioactivity levels on the coupons. Varying levels of success were achieved for the preconditioning techniques tested. Electropolishing alone provided some degree of resistance to radiation buildup on the treated surface and electropolishing plus passivation was shown to be even better. Radiation buildup resistance of the palladium-coated coupons was poor; radiation levels on these coupons were even higher than on the untreated reference coupons. The poor performance of the palladium-coated coupons was possibly due to the method used to apply the coating. In contrast to palladium coating, very encouraging results were achieved with chromium plating plus passivation. Preliminary results show that this technique can inhibit activity deposition by as much as a factor of ten. 4 refs., 64 figs., 26 tabs

  3. Characterizing polycyclic aromatic hydrocarbon build-up processes on urban road surfaces

    International Nuclear Information System (INIS)

    Liu, Liang; Liu, An; Li, Dunzhu; Zhang, Lixun; Guan, Yuntao

    2016-01-01

    Reliable prediction models are essential for modeling pollutant build-up processes on urban road surfaces. Based on successive samplings of road deposited sediments (RDS), this study presents empirical models for mathematical replication of the polycyclic aromatic hydrocarbon (PAH) build-up processes on urban road surfaces. The contaminant build-up behavior was modeled using saturation functions, which are commonly applied in US EPA's Stormwater Management Model (SWMM). Accurate fitting results were achieved in three typical urban land use types, and the applicability of the models was confirmed based on their acceptable relative prediction errors. The fitting results showed high variability in PAH saturation value and build-up rate among different land use types. Results of multivariate data and temporal-based analyses suggested that the quantity and property of RDS significantly influenced PAH build-up. Furthermore, pollution sources, traffic parameters, road surface conditions, and sweeping frequency could synthetically impact the RDS build-up and RDS property change processes. Thus, changes in these parameters could be the main reason for variations in PAH build-up in different urban land use types. - Highlights: • Sufficient robust prediction models were established for analysis of PAH build-up on urban road surfaces. • PAH build-up processes showed high variability among different land use types. • Pollution sources as well as the quantity and property of RDS mainly influenced PAH build-up. - Sufficient robust prediction models were established for analysis of PAH build-up on urban road surfaces. Pollution sources as well as the quantity and property of RDS mainly influenced PAH build-up.

  4. Characterizing heavy metal build-up on urban road surfaces: Implication for stormwater reuse

    International Nuclear Information System (INIS)

    Liu, An; Liu, Liang; Li, Dunzhu; Guan, Yuntao

    2015-01-01

    Stormwater reuse is increasingly popular in the worldwide. In terms of urban road stormwater, it commonly contains toxic pollutants such as heavy metals, which could undermine the reuse safety. The research study investigated heavy metal build-up characteristics on urban roads in a typical megacity of South China. The research outcomes show the high variability in heavy metal build-up loads among different urban road sites. The degree of traffic congestion and road surface roughness was found to exert a more significant influence on heavy metal build-up rather than traffic volume. Due to relatively higher heavy metal loads, stormwater from roads with more congested traffic conditions or rougher surfaces might be suitable for low-water-quality required activities while the stormwater from by-pass road sections could be appropriate for relatively high-water-quality required purposes since the stormwater could be relatively less polluted. Based on the research outcomes, a decision-making process for heavy metals based urban road stormwater reuse was proposed. The new finding highlights the importance to undertaking a “fit-for-purpose” road stormwater reuse strategy. Additionally, the research results can also contribute to enhancing stormwater reuse safety. - Highlights: • Heavy metal (HM) build-up varies with traffic and road surface conditions. • Traffic congestion and surface roughness exert a higher impact on HM build-up. • A “fit-for-purpose” strategy could suit urban road stormwater reuse

  5. Characterizing heavy metal build-up on urban road surfaces: Implication for stormwater reuse

    Energy Technology Data Exchange (ETDEWEB)

    Liu, An [Research Centre of Environmental Engineering and Management, Graduate School at Shenzhen, Tsinghua University, 518055 Shenzhen (China); Cooperative Research and Education Centre for Environmental Technology, Kyoto University–Tsinghua University, 518055 Shenzhen (China); Liu, Liang; Li, Dunzhu [Research Centre of Environmental Engineering and Management, Graduate School at Shenzhen, Tsinghua University, 518055 Shenzhen (China); Guan, Yuntao, E-mail: guanyt@tsinghua.edu.cn [Research Centre of Environmental Engineering and Management, Graduate School at Shenzhen, Tsinghua University, 518055 Shenzhen (China); School of Environment, Tsinghua University, Beijing 100084 (China)

    2015-05-15

    Stormwater reuse is increasingly popular in the worldwide. In terms of urban road stormwater, it commonly contains toxic pollutants such as heavy metals, which could undermine the reuse safety. The research study investigated heavy metal build-up characteristics on urban roads in a typical megacity of South China. The research outcomes show the high variability in heavy metal build-up loads among different urban road sites. The degree of traffic congestion and road surface roughness was found to exert a more significant influence on heavy metal build-up rather than traffic volume. Due to relatively higher heavy metal loads, stormwater from roads with more congested traffic conditions or rougher surfaces might be suitable for low-water-quality required activities while the stormwater from by-pass road sections could be appropriate for relatively high-water-quality required purposes since the stormwater could be relatively less polluted. Based on the research outcomes, a decision-making process for heavy metals based urban road stormwater reuse was proposed. The new finding highlights the importance to undertaking a “fit-for-purpose” road stormwater reuse strategy. Additionally, the research results can also contribute to enhancing stormwater reuse safety. - Highlights: • Heavy metal (HM) build-up varies with traffic and road surface conditions. • Traffic congestion and surface roughness exert a higher impact on HM build-up. • A “fit-for-purpose” strategy could suit urban road stormwater reuse.

  6. Modelling heavy metals build-up on urban road surfaces for effective stormwater reuse strategy implementation

    International Nuclear Information System (INIS)

    Hong, Nian; Zhu, Panfeng; Liu, An

    2017-01-01

    Urban road stormwater is an alternative water resource to mitigate water shortage issues in the worldwide. Heavy metals deposited (build-up) on urban road surface can enter road stormwater runoff, undermining stormwater reuse safety. As heavy metal build-up loads perform high variabilities in terms of spatial distribution and is strongly influenced by surrounding land uses, it is essential to develop an approach to identify hot-spots where stormwater runoff could include high heavy metal concentrations and hence cannot be reused if it is not properly treated. This study developed a robust modelling approach to estimating heavy metal build-up loads on urban roads using land use fractions (representing percentages of land uses within a given area) by an artificial neural network (ANN) model technique. Based on the modelling results, a series of heavy metal load spatial distribution maps and a comprehensive ecological risk map were generated. These maps provided a visualization platform to identify priority areas where the stormwater can be safely reused. Additionally, these maps can be utilized as an urban land use planning tool in the context of effective stormwater reuse strategy implementation. - Highlights: • A model was developed to simulate heavy metal build-up loads on urban roads. • This model is based on artificial neural networks. • Land use fractions was used to model build-up loads on different particle sizes. • The maps of heavy metal spatial distribution and ecological risk were generated. • This model can be used for effective stormwater reuse strategy implementation. - Development of a robust modelling approach to mapping heavy metals build-up and their ecological risks for stormwater reuse safety.

  7. Build-up dynamics of heavy metals deposited on impermeable urban surfaces.

    Science.gov (United States)

    Wicke, D; Cochrane, T A; O'Sullivan, A

    2012-12-30

    A method using thin boards (3 cm thick, 0.56 m(2)) comprising different paving materials typically used in urban environments (2 asphalt types and concrete) was employed to specifically investigate air-borne deposition dynamics of TSS, zinc, copper and lead. Boards were exposed at an urban car park near vehicular traffic to determine the rate of contaminant build-up over a 13-day dry period. Concentration profiles from simulated rainfall wash-off were used to determine contaminant yields at different antecedent dry days. Maximum contaminant yields after 13 days of exposure were 2.7 kg ha(-1) for TSS, 35 g ha(-1) zinc, 2.3 g ha(-1) copper and 0.4 g ha(-1) lead. Accumulation of all contaminants increased over the first week and levelled off thereafter, supporting theoretical assumptions that contaminant accumulation on impervious surfaces asymptotically approaches a maximum. Comparison of different surface types showed approximately four times higher zinc concentrations in runoff from asphalt surfaces and two times higher TSS concentrations in runoff from concrete, which is attributed to different physical and chemical compositions of the pavement types. Contaminant build-up and wash-off behaviours were modelled using exponential and saturation functions commonly applied in the US EPA's Stormwater Management Model (SWMM) showing good correlation between measured and modelled concentrations. Maximum build-up, half-saturation time, build-up rate constants and wash-off coefficients, necessary for stormwater contaminant modelling, were determined for the four contaminants studied. These parameters are required to model contaminant concentrations in urban runoff assisting in stormwater management decisions. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Change in surface SP caused by pressure buildup observed at the Nigorikawa geothermal area; Nigorikawa chiiki ni okeru atsuryoku buildup ji no shizen den`i henka

    Energy Technology Data Exchange (ETDEWEB)

    Yasukawa, K; Yano, Y; Matsushima, N; Ishido, T [Geological Survey of Japan, Tsukuba (Japan); Takahashi, M; Suzuki, I; Aoyama, K; Kuwano, T

    1996-10-01

    To examine the effect of change of subsurface flow system on the surface SP (self potential), SP measurements were carried out before and after the pressure buildup and drawdown during the periodic inspection at Nigorikawa area. Relation between the SP distribution and the observed data was also examined by 2-D numerical simulation. Tendency was found that the SP increased gradually with the production near the production well, decreased during the pressure buildup, and increased again during the drawdown. There were some points having the reverse tendency in the surrounding area. Behavior during the pressure buildup and drawdown was not clear. The resistivity near the ground surface was low ranging between 2 and 5 ohm/m within the Nigorikawa basin. The variation of SP was not so large when compared with the measuring error. The SP profiles on the secondary section passing in the center of caldera at the production stop and at one week after the production start were well corresponded with the profiles under natural conditions which were reproduces using the 2-D model. It was considered that the SP profile before the production stop was affected by the production. 12 refs., 6 figs., 1 tab.

  9. Modelling heavy metals build-up on urban road surfaces for effective stormwater reuse strategy implementation.

    Science.gov (United States)

    Hong, Nian; Zhu, Panfeng; Liu, An

    2017-12-01

    Urban road stormwater is an alternative water resource to mitigate water shortage issues in the worldwide. Heavy metals deposited (build-up) on urban road surface can enter road stormwater runoff, undermining stormwater reuse safety. As heavy metal build-up loads perform high variabilities in terms of spatial distribution and is strongly influenced by surrounding land uses, it is essential to develop an approach to identify hot-spots where stormwater runoff could include high heavy metal concentrations and hence cannot be reused if it is not properly treated. This study developed a robust modelling approach to estimating heavy metal build-up loads on urban roads using land use fractions (representing percentages of land uses within a given area) by an artificial neural network (ANN) model technique. Based on the modelling results, a series of heavy metal load spatial distribution maps and a comprehensive ecological risk map were generated. These maps provided a visualization platform to identify priority areas where the stormwater can be safely reused. Additionally, these maps can be utilized as an urban land use planning tool in the context of effective stormwater reuse strategy implementation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Role of urban surface roughness in road-deposited sediment build-up and wash-off

    Science.gov (United States)

    Zhao, Hongtao; Jiang, Qian; Xie, Wenxia; Li, Xuyong; Yin, Chengqing

    2018-05-01

    Urban road surface roughness is one of the most important factors in estimation of surface runoff loads caused by road-deposited sediment (RDS) wash-off and design of its control measures. However, because of a lack of experimental data to distinguish the role of surface roughness, the effects of surface roughness on RDS accumulation and release are not clear. In this study, paired asphalt and concrete road surfaces and rainfall simulation designs were used to distinguish the role of surface roughness in RDS build-up and wash-off. Our results showed that typical asphalt surfaces often have higher depression depths than typical concrete surfaces, indicating that asphalt surfaces are relatively rougher than concrete surface. Asphalt surfaces can retain a larger RDS amount, relative higher percentage of coarser particles, larger RDS wash-off loads, and lower wash-off percentage, than concrete surfaces. Surface roughness has different effects in RDS motilities with different particle sizes during rainfall runoff, and the settleable particles (44-149 μm) were notably influenced by it. Furthermore, the first flush phenomenon tended to be greater on relatively smooth surfaces than relatively rough surfaces. Overall, surface roughness plays an important role in influencing the complete process of RDS build-up and wash-off on different road characteristics.

  11. Evaluation of surface and build-up region dose for intensity-modulated radiation therapy in head and neck cancer

    International Nuclear Information System (INIS)

    Chung, Heeteak; Jin, Hosang; Dempsey, James F.; Liu, Chihray; Palta, Jatinder; Suh, Tae-Suk; Kim, Siyong

    2005-01-01

    Despite much development, there remains dosimetric uncertainty in the surface and build-up regions in intensity-modulated radiation therapy treatment plans for head and neck cancers. Experiments were performed to determine the dosimetric discrepancies in the surface and build-up region between the treatment planning system (TPS) prediction and experimental measurement using radiochromic film. A head and neck compression film phantom was constructed from two semicylindrical solid water slabs. Treatment plans were generated using two commercial TPSs (PINNACLE3 and CORVUS) for two cases, one with a shallow (∼0.5 cm depth) target and another with a deep (∼6 cm depth) target. The plans were evaluated for a 54 Gy prescribed dose. For each case, two pieces of radiochromic film were used for dose measurement. A small piece of film strip was placed on the surface and another was inserted within the phantom. Overall, both TPSs showed good agreement with the measurement. For the shallow target case, the dose differences were within ±300 cGy (5.6% with respect to the prescribed dose) for PINNACLE3 and ±240 cGy (4.4%) for CORVUS in 90% of the region of interest. For the deep target case, the dose differences were ±350 (6.5%) for PINNACLE3 and ±260 cGy (4.8%) for CORVUS in 90% of the region of interest. However, it was found that there were significant discrepancies from the surface to about 0.2 cm in depth for both the shallow and deep target cases. It was concluded that both TPSs overestimated the surface dose for both shallow and deep target cases. The amount of overestimation ranges from 400 to 1000 cGy (∼7.4% to 18.5% with respect to the prescribed dose, 5400 cGy)

  12. Effect of various physical parameters on surface and build-up dose for 15-MV X-rays

    International Nuclear Information System (INIS)

    Yadav, Girigesh; Yadav, R.S.; Kumar, Alok

    2010-01-01

    The purpose of this study was to find out the effect of various physical parameters on the skin and build-up doses of 15-MV photon beams. The effects of field dimensions, acrylic shadow tray, focus to-skin distance (FSD) on surface and buildup dose were determined for open, motorized 60 deg wedge (MW) and blocked fields. A 'Markus' plane parallel plate chamber was used for these measurements in an Elekta (6-15MV) linear accelerator. The surface dose for MW fields was lower than the dose for an open field, but the trend reversed for large fields and higher degree wedges. With the use of an acrylic shadow tray, the surface dose increased for all field sizes, but the increase was dominant for large fields. The surface dose for blocked fields was lower than the dose for open fields. The percentage depth dose of 10 x 10 cm 2 field at surface (PDD 0 ) for open beam were 13.89%, 11.71%, and 10.74% at 80 cm, 100 cm, and 120 cm FSD, respectively. The blocking tray increased PDD 0 of 10 x 10 cm 2 field to 26.29%, 14.01%, and 11.53%, while the motorized 60 deg wedge decreased PDD 0 to 11.32%, 9.7%, and 8.9 % at these FSDs. The maximum PDD difference seen at surface (i.e. skin) for 5x5 cm 2 , 15x15 cm 2 , and 30x30 cm 2 are 0.5%, 4.6%, and 5.6% for open field and 0.9%, 4.7%, and 7.2% for motorized 60 deg wedge field, when FSDs varied from 80 cm to 120 cm. The maximum PDD difference seen at surface for 5x5 cm 2 , 15x15 cm 2 , and 30x30 cm 2 fields are 5.6%, 22.8%, and 29.6%, respectively, for a 1.0-cm perspex-blocking tray as the FSD is changed. The maximum PDD difference was seen at the surface (i.e. skin) and this decreased with increasing depth. (author)

  13. Measurements of dose on build-up region, surface dose and outlet dose by a 10 MeV Linear accelerator

    International Nuclear Information System (INIS)

    Souza, C.N. de; Khoury, H.J.

    1987-01-01

    The dose on buildup region and the surface dose for a 10 MeV photon beam from a linear acelerator (Mevatrom-74, Siemens) is studied. The influence of the tray of polycarbonate on the surface dose is determined. (M.A.C.) [pt

  14. The computation of the build-up of long-lived radioisotopes on the surface of primary circuits and the ion exchange material of BWR

    International Nuclear Information System (INIS)

    Lundgren, K.

    1980-06-01

    The buildup of radionuclides on the surface of the primary circuits and in the ion exchange material is calculated. The computation is made by the computer code 'CRUD'. The buildup is interesting from the viewpoint of nuclear waste. Oskarshamn 2 is chosen as the reference plant. An extrapolation is made for 20 years of operation. Calculation are givin for Mn54, Fe55, Co60, Ni59, Ni63 and Zn65. The constants of deposition and disharge are determined by fitting the values. (G.B.)

  15. SU-E-J-239: Influence of RF Coil Materials On Surface and Buildup Dose From a 6MV Photon Beam

    Energy Technology Data Exchange (ETDEWEB)

    Ghila, A; Fallone, B; Rathee, S [Cross Cancer Institute, Edmonton, AB (United Kingdom)

    2015-06-15

    Purpose: In order to perform real time tumour tracking using an integrated Linac-MR, images have to be acquired during irradiation. MRI uses RF coils in close proximity to the imaged volume. Given current RF coil designs this means that the high energy photons will be passing through the coil before reaching the patient. This study experimentally investigates the dose modifications that occur due to the presence of various RF coil materials in the treatment beam. Methods: Polycarbonate, copper or aluminum tape, and Teflon were used to emulate the base, conductor and cover respectively of a surface RF coil. These materials were placed at various distances from the surface of polystyrene or solid water phantoms which were irradiated in the presence of no magnetic field, a transverse 0.2T magnetic field, and a parallel 0.2T magnetic field. Percent depth doses were measured using ion chambers. Results: A significant increase in surface and buildup dose is observed. The surface dose is seen to decrease with an increasing separation between the emulated coil and the phantom surface, when no magnetic field is present. When a transverse magnetic field is applied the surface dose decreases faster with increasing separation, as some of the electrons created in the coil are curved away from the phantom’s surface. When a parallel field is present the surface dose stays approximately constant for small separations, only slightly decreasing for separations greater than 5cm, since the magnetic field focuses the electrons produced in the coil materials not allowing them to scatter. Conclusion: Irradiating a patient through an RF coil leads to an increase in the surface and buildup doses. Mitigating this increase is important for the successful clinical use of either a transverse or a parallel configuration Linac-MR unit. This project is partially supported by an operating grant from the Canadian Institute of Health Research (CIHR MOP 93752)

  16. Analysis of the build-up of semi and non volatile organic compounds on urban roads.

    Science.gov (United States)

    Mahbub, Parvez; Ayoko, Godwin A; Goonetilleke, Ashantha; Egodawatta, Prasanna

    2011-04-01

    Vehicular traffic in urban areas may adversely affect urban water quality through the build-up of traffic generated semi and non volatile organic compounds (SVOCs and NVOCs) on road surfaces. The characterisation of the build-up processes is the key to developing mitigation measures for the removal of such pollutants from urban stormwater. An in-depth analysis of the build-up of SVOCs and NVOCs was undertaken in the Gold Coast region in Australia. Principal Component Analysis (PCA) and Multicriteria Decision tools such as PROMETHEE and GAIA were employed to understand the SVOC and NVOC build-up under combined traffic scenarios of low, moderate, and high traffic in different land uses. It was found that congestion in the commercial areas and use of lubricants and motor oils in the industrial areas were the main sources of SVOCs and NVOCs on urban roads, respectively. The contribution from residential areas to the build-up of such pollutants was hardly noticeable. It was also revealed through this investigation that the target SVOCs and NVOCs were mainly attached to particulate fractions of 75-300 μm whilst the redistribution of coarse fractions due to vehicle activity mainly occurred in the >300 μm size range. Lastly, under combined traffic scenario, moderate traffic with average daily traffic ranging from 2300 to 5900 and average congestion of 0.47 were found to dominate SVOC and NVOC build-up on roads. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Build-up and surface dose measurements on phantoms using micro-MOSFET in 6 and 10 MV x-ray beams and comparisons with Monte Carlo calculations

    International Nuclear Information System (INIS)

    Xiang, Hong F.; Song, Jun S.; Chin, David W. H.; Cormack, Robert A.; Tishler, Roy B.; Makrigiorgos, G. Mike; Court, Laurence E.; Chin, Lee M.

    2007-01-01

    This work is intended to investigate the application and accuracy of micro-MOSFET for superficial dose measurement under clinically used MV x-ray beams. Dose response of micro-MOSFET in the build-up region and on surface under MV x-ray beams were measured and compared to Monte Carlo calculations. First, percentage-depth-doses were measured with micro-MOSFET under 6 and 10 MV beams of normal incidence onto a flat solid water phantom. Micro-MOSFET data were compared with the measurements from a parallel plate ionization chamber and Monte Carlo dose calculation in the build-up region. Then, percentage-depth-doses were measured for oblique beams at 0 deg. - 80 deg. onto the flat solid water phantom with micro-MOSFET placed at depths of 2 cm, 1 cm, and 2 mm below the surface. Measurements were compared to Monte Carlo calculations under these settings. Finally, measurements were performed with micro-MOSFET embedded in the first 1 mm layer of bolus placed on a flat phantom and a curved phantom of semi-cylindrical shape. Results were compared to superficial dose calculated from Monte Carlo for a 2 mm thin layer that extends from the surface to a depth of 2 mm. Results were (1) Comparison of measurements with MC calculation in the build-up region showed that micro-MOSFET has a water-equivalence thickness (WET) of 0.87 mm for 6 MV beam and 0.99 mm for 10 MV beam from the flat side, and a WET of 0.72 mm for 6 MV beam and 0.76 mm for 10 MV beam from the epoxy side. (2) For normal beam incidences, percentage depth dose agree within 3%-5% among micro-MOSFET measurements, parallel-plate ionization chamber measurements, and MC calculations. (3) For oblique incidence on the flat phantom with micro-MOSFET placed at depths of 2 cm, 1 cm, and 2 mm, measurements were consistent with MC calculations within a typical uncertainty of 3%-5%. (4) For oblique incidence on the flat phantom and a curved-surface phantom, measurements with micro-MOSFET placed at 1.0 mm agrees with the MC

  18. Scenarios

    NARCIS (Netherlands)

    Pérez-Soba, Marta; Maas, Rob

    2015-01-01

    We cannot predict the future with certainty, but we know that it is influenced by our current actions, and that these in turn are influenced by our expectations. This is why future scenarios have existed from the dawn of civilization and have been used for developing military, political and economic

  19. In-situ buildup of cosmogenic isotopes at the earth`s surface: measurement of erosion rates and exposure times

    Energy Technology Data Exchange (ETDEWEB)

    Fifield, L K; Allan, G L; Stone, J O.H.; Evans, J M; Cresswell, R G; Ophel, T R [Australian National Univ., Canberra, ACT (Australia)

    1994-12-31

    Cosmic rays produce a number of nuclides in rocks that can be used to determine the geomorphic history of surfaces. The most useful are the radioactive isotopes {sup 10}Be (t{sub 1/2} = 1.5Ma), {sup 26}Al (0.7Ma) and {sup 36}Cl (0.3Ma). Within the top 2m of the surface, these are produced principally by fast neutrons. At greater depths, production is dominated by the capture of negative muons. Measurements of a single nuclide produced in situ can be used to determine total exposure times or erosion rates. The use of multiple nuclides with different half-lives makes it possible to determine more complex histories, such as exposures interrupted by periods of burial. At the ANU, all three of the isotopes above are being used to study a variety of problems in geomorphology and paleoclimatology, although to date, most of the work has concentrated on {sup 36}Cl. The accumulation of cosmogenic {sup 36}Cl in calcite (CaCO{sub 3}) provides a means of measuring erosion rates on limestone surfaces. Sensitivity is achieved over a wide range of erosion rates due to the high production rate of {sup 36}Cl in calcite (typically greater than 30 atoms/g/yr) and a detection limit of ca. 5000 atoms/g attainable with the ANU AMS system. The method is simplified by the predominance of Ca reactions (principally spallation) over other sources of {sup 36}Cl in calcite, and the ease of sample preparation. This presentation discuss the results of measurements of {sup 36}Cl in calcite from limestone samples from Australia and Papua New Guinea. Erosion rates derived from these measurements range from 3 microns per year (Australia) to over 200 microns per year in the New Guinea highlands. 3 refs.

  20. In-situ buildup of cosmogenic isotopes at the earth's surface: measurement of erosion rates and exposure times

    International Nuclear Information System (INIS)

    Fifield, L.K.; Allan, G.L.; Stone, J.O.H.; Evans, J.M.; Cresswell, R.G.; Ophel, T.R.

    1993-01-01

    Cosmic rays produce a number of nuclides in rocks that can be used to determine the geomorphic history of surfaces. The most useful are the radioactive isotopes 10 Be (t 1/2 = 1.5Ma), 26 Al (0.7Ma) and 36 Cl (0.3Ma). Within the top 2m of the surface, these are produced principally by fast neutrons. At greater depths, production is dominated by the capture of negative muons. Measurements of a single nuclide produced in situ can be used to determine total exposure times or erosion rates. The use of multiple nuclides with different half-lives makes it possible to determine more complex histories, such as exposures interrupted by periods of burial. At the ANU, all three of the isotopes above are being used to study a variety of problems in geomorphology and paleoclimatology, although to date, most of the work has concentrated on 36 Cl. The accumulation of cosmogenic 36 Cl in calcite (CaCO 3 ) provides a means of measuring erosion rates on limestone surfaces. Sensitivity is achieved over a wide range of erosion rates due to the high production rate of 36 Cl in calcite (typically greater than 30 atoms/g/yr) and a detection limit of ca. 5000 atoms/g attainable with the ANU AMS system. The method is simplified by the predominance of Ca reactions (principally spallation) over other sources of 36 Cl in calcite, and the ease of sample preparation. This presentation discuss the results of measurements of 36 Cl in calcite from limestone samples from Australia and Papua New Guinea. Erosion rates derived from these measurements range from 3 microns per year (Australia) to over 200 microns per year in the New Guinea highlands. 3 refs

  1. In-situ buildup of cosmogenic isotopes at the earth`s surface: measurement of erosion rates and exposure times

    Energy Technology Data Exchange (ETDEWEB)

    Fifield, L.K.; Allan, G.L.; Stone, J.O.H.; Evans, J.M.; Cresswell, R.G.; Ophel, T.R. [Australian National Univ., Canberra, ACT (Australia)

    1993-12-31

    Cosmic rays produce a number of nuclides in rocks that can be used to determine the geomorphic history of surfaces. The most useful are the radioactive isotopes {sup 10}Be (t{sub 1/2} = 1.5Ma), {sup 26}Al (0.7Ma) and {sup 36}Cl (0.3Ma). Within the top 2m of the surface, these are produced principally by fast neutrons. At greater depths, production is dominated by the capture of negative muons. Measurements of a single nuclide produced in situ can be used to determine total exposure times or erosion rates. The use of multiple nuclides with different half-lives makes it possible to determine more complex histories, such as exposures interrupted by periods of burial. At the ANU, all three of the isotopes above are being used to study a variety of problems in geomorphology and paleoclimatology, although to date, most of the work has concentrated on {sup 36}Cl. The accumulation of cosmogenic {sup 36}Cl in calcite (CaCO{sub 3}) provides a means of measuring erosion rates on limestone surfaces. Sensitivity is achieved over a wide range of erosion rates due to the high production rate of {sup 36}Cl in calcite (typically greater than 30 atoms/g/yr) and a detection limit of ca. 5000 atoms/g attainable with the ANU AMS system. The method is simplified by the predominance of Ca reactions (principally spallation) over other sources of {sup 36}Cl in calcite, and the ease of sample preparation. This presentation discuss the results of measurements of {sup 36}Cl in calcite from limestone samples from Australia and Papua New Guinea. Erosion rates derived from these measurements range from 3 microns per year (Australia) to over 200 microns per year in the New Guinea highlands. 3 refs.

  2. Plastics control paraffin buildup

    Energy Technology Data Exchange (ETDEWEB)

    1965-06-01

    Paraffin buildup in producing oil wells has been virtually eliminated by the use of plastic-coated sucker rods. The payout of the plasticing process is generally reached in less than a year, and the paraffin buildup may be inhibited for 10 yr or longer. Most of the plants applying plastic coatings to sucker rods are now fully automated, though a few still offer the hand-sprayed coating that some operators prefer. The several steps involved are described. The ideal plastic for the job is resistant to chemicals at high and low temperatures, flexible, has good adhesion, abrasion resistance, impact resistance, and a smooth glossy finish. The phenol aldehyde and epoxy resins presently offered by the industry fulfill these specifications very well; the multicoating and multibaking techniques improve their performance. Due to wide variations in the severity of the paraffin problem from one oil field to another, there is no general rule to estimate the possible savings from using plastic-coated sucker rods. The process, however, does appear to do a remarkable job in controlling paraffin buildup wherever it is a problem in producing oil by pump.

  3. Surface WAter Scenario Help (SWASH) version 5.3 : technical description

    NARCIS (Netherlands)

    Roller, te J.A.; Berg, van den F.; Adriaanse, P.I.; Jong, de A.; Beltman, W.H.J.

    2015-01-01

    The user-friendly shell SWASH, acronym for Surface WAter Scenarios Help, assists the user in calculating pesticide exposure concentrations in the EU FOCUS surface water scenarios. SWASH encompasses five separate tools and models: (i) FOCUS Drift Calculator, calculating pesticide entries through

  4. Surface relief gratings: experiments, physical scenarios, and photoinduced (anomalous) dynamics of functionalized polymer chains

    Science.gov (United States)

    Mitus, A. C.; Radosz, W.; Wysoczanski, T.; Pawlik, G.

    2017-10-01

    Surface Relief Gratings (SRG) were demonstrated experimentally more than 20 years ago. Despite many years of research efforts the underlying physical mechanisms remain unclear. In this paper we present a short overview of the main concepts related to SRG - photofluidization and its counterpart, the orientational approach - based on a seminal paper by Saphiannikova et al. Next, we summarize the derivation of the cos2 θ potential, following the lines of recent paper of this group. Those results validate the generic Monte Carlo model for the photoinduced build-up of the density and SRG gratings in a model polymer matrix functionalized with azo-dyes, presented in another part of the paper. The characterization of the photoinduced motion of polymer chains, based on our recent paper, is briefly discussed in the last part of the paper. This discussion offers a sound insight into the mechanisms responsible for inscription of SRG as well as for single functionalized nanoparticle studies.

  5. AAA and PBC calculation accuracy in the surface build-up region in tangential beam treatments. Phantom and breast case study with the Monte Carlo code PENELOPE

    International Nuclear Information System (INIS)

    Panettieri, Vanessa; Barsoum, Pierre; Westermark, Mathias; Brualla, Lorenzo; Lax, Ingmar

    2009-01-01

    Background and purpose: In tangential beam treatments accurate dose calculation of the absorbed dose in the build-up region is of major importance, in particular when the target has superficial extension close to the skin. In most analytical treatment planning systems (TPSs) calculations depend on the experimental measurements introduced by the user in which accuracy might be limited by the type of detector employed to perform them. To quantify the discrepancy between analytically calculated and delivered dose in the build-up region, near the skin of a patient, independent Monte Carlo (MC) simulations using the PENELOPE code were performed. Dose distributions obtained with MC simulations were compared with those given by the Pencil Beam Convolution (PBC) algorithm and the Analytical Anisotropic Algorithm (AAA) implemented in the commercial TPS Eclipse. Material and methods: A cylindrical phantom was used to approximate the breast contour of a patient for MC simulations and the TPS. Calculations of the absorbed doses were performed for 6 and 18 MV beams for four different angles of incidence: 15 deg., 30 deg., 45 deg. and 75 deg. and different field sizes: 3 x 3 cm 2 , 10 x 10 cm 2 and 40 x 40 cm 2 . Absorbed doses along the phantom central axis were obtained with both the PBC algorithm and the AAA and compared to those estimated by the MC simulations. Additionally, a breast patient case was calculated with two opposed 6 MV photon beams using all the aforementioned analytical and stochastic algorithms. Results: For the 6 MV photon beam in the phantom case, both the PBC algorithm and the AAA tend to underestimate the absorbed dose in the build-up region in comparison to MC results. These differences are clinically irrelevant and are included in a 1 mm range. This tendency is also confirmed in the breast patient case. For the 18 MV beam the PBC algorithm underestimates the absorbed dose with respect to the AAA. In comparison to MC simulations the PBC algorithm tends

  6. BWR radiation buildup control with ionic zinc

    International Nuclear Information System (INIS)

    Marble, W.J.; Wood, C.J.; Leighty, C.E.; Green, T.A.

    1986-01-01

    In 1983 a hypothesis was disclosed which suggested that the presence of ionic zinc in the reactor water of the BWR could reduce radiation buildup. This hypothesis was developed from correlations of plant data, and subsequently, from laboratory experiments which demonstrated clearly that ionic zinc inhibits the corrosion of stainless steel. The benefits of zinc addition have been measured at the Vallecitos Nuclear Center under and EPRI/GE project. Experimentation and analyses have been performed to evaluate the impact of intentional zinc addition on the IGSCC characteristics of primary system materials and on the performance of the nuclear fuel. It has been concluded that no negative effects are expected. The author conclude that the intentional addition of ionic zinc to the BWR reactor water at a concentration of approximately 10 ppb will provide major benefits in controlling the Co-60 buildup on primary system stainless steel surfaces. The intentional addition of zinc is now a qualified technique for use in BWRs

  7. Health burdens of surface ozone in the UK for a range of future scenarios

    OpenAIRE

    Heal, Mathew R.; Heaviside, Clare; Doherty, Ruth M.; Vieno, Massimo; Stevenson, David S.; Vardoulakis, Sotiris

    2013-01-01

    Exposure to surface ozone (O3), which is influenced by emissions of precursor chemical species, meteorology and population distribution, is associated with excess mortality and respiratory morbidity. In this study, the EMEP-WRF atmospheric chemistry transport model was used to simulate surface O3 concentrations at 5 km horizontal resolution over the British Isles for a baseline year of 2003, for three anthropogenic emissions scenarios for 2030, and for a + 5 °C increase in air temperature on ...

  8. Recent sea surface temperature trends and future scenarios for the Mediterranean Sea:

    Directory of Open Access Journals (Sweden)

    Mohamed Shaltout

    2014-06-01

    Full Text Available We analyse recent Mediterranean Sea surface temperatures (SSTs and their response to global change using 1/4-degree gridded advanced very-high-resolution radiometer (AVHRR daily SST data, 1982-2012. These data indicate significant annual warming (from 0.24°C decade-1 west of the Strait of Gibraltar to 0.51°C decade-1 over the Black Sea and significant spatial variation in annual average SST (from 15ºC over the Black Sea to 21°C over the Levantine sub-basin. Ensemble mean scenarios indicate that the study area SST may experience significant warming, peaking at 2.6°C century-1 in the Representative Concentration Pathways 85 (RCP85 scenario.

  9. Recent sea surface temperature trends and future scenarios for the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Mohamed Shaltout

    2014-06-01

    Full Text Available We analyse recent Mediterranean Sea surface temperatures (SSTs and their response to global change using 1/4-degree gridded advanced very-high-resolution radiometer (AVHRR daily SST data, 1982–2012. These data indicate significant annual warming (from 0.24 °C decade−1 west of the Strait of Gibraltar to 0.51 °C decade−1 over the Black Sea and significant spatial variation in annual average SST (from 15 °C over the Black Sea to 21 °C over the Levantine sub-basin. Ensemble mean scenarios indicate that the study area SST may experience significant warming, peaking at 2.6 °C century−1 in the Representative Concentration Pathways 85 (RCP85 scenario.

  10. Energy absorption build-up factors in teeth

    International Nuclear Information System (INIS)

    Manjunatha, H.C.; Rudraswamy, B.

    2012-01-01

    Geometric progression fitting method has been used to compute energy absorption build-up factor of teeth [enamel outer surface, enamel middle, enamel dentin junction towards enamel, enamel dentin junction towards dentin, dentin middle and dentin inner surface] for wide energy range (0.015-15 MeV) up to the penetration depth of 40 mean free path. The dependence of energy absorption build-up factor on incident photon energy, penetration depth, electron density and effective atomic number has also been studied. The energy absorption build-up factors increases with the penetration depth and electron density of teeth. So that the degree of violation of Lambert-Beer (I = I 0 e -μt ) law is less for least penetration depth and electron density. The energy absorption build-up factors for different regions of teeth are not same hence the energy absorbed by the different regions of teeth is not uniform which depends on the composition of the medium. The relative dose of gamma in different regions of teeth is also estimated. Dosimetric implication of energy absorption build-up factor in teeth has also been discussed. The estimated absorption build up factors in different regions of teeth may be useful in the electron spin resonance dosimetry. (author)

  11. SU-E-T-184: Feasibility of Superabsorbent Polymers as a Buildup Material

    Energy Technology Data Exchange (ETDEWEB)

    Tseng, T; Sheu, R; Lo, Y [Mount Sinai Medical Center, NY, NY (United States)

    2014-06-01

    Purpose: To investigate the feasibility of superabsorbent polymers as a buildup material for radiation therapy Methods: A standard bolus, a layered damp towel, and a superabsorbent polymer (SAP) phantom were created and scanned to compare the Hounsfield units of each buildup material. A single field plan was developed on Eclipse TPS with AAA dose calculation algorithm to examine dose buildup. Relative film dosimetery (EBT3) was performed to evaluate the surface dose with each buildup material. Each buildup material had an approximate thickness of 0.5 cm and 100 monitor units with 6MV were delivered with solid water placed underneath film to simulate backscatter and more realistic surface dose. Results: The average HU units of the bolus, wet towel, and SAP phantom were 75 (SD=3), -378 (SD=113), -198 (SD=45) respectively. AAA dose calculation demonstrated sufficient dose buildup in all three materials. The relative surfaces doses to film were 23.7% without buildup, 87.5% with 0.5 cm bolus, 92.4% for the SAP phantom, and 87.1% for the damp towel. Conclusion: We demonstrate that superabsorbent polymers can provide sufficient dose buildup. Furthermore, due to the form in which SAPs are traditionally manufactured, this material is less expensive conforms more easily to irregular surfaces than standard sheets of bolus. Also, as a substance which is designed to absorb and retain water efficiently, SAPs are much more comfortable and more consistent than damp towels.

  12. SU-E-T-184: Feasibility of Superabsorbent Polymers as a Buildup Material

    International Nuclear Information System (INIS)

    Tseng, T; Sheu, R; Lo, Y

    2014-01-01

    Purpose: To investigate the feasibility of superabsorbent polymers as a buildup material for radiation therapy Methods: A standard bolus, a layered damp towel, and a superabsorbent polymer (SAP) phantom were created and scanned to compare the Hounsfield units of each buildup material. A single field plan was developed on Eclipse TPS with AAA dose calculation algorithm to examine dose buildup. Relative film dosimetery (EBT3) was performed to evaluate the surface dose with each buildup material. Each buildup material had an approximate thickness of 0.5 cm and 100 monitor units with 6MV were delivered with solid water placed underneath film to simulate backscatter and more realistic surface dose. Results: The average HU units of the bolus, wet towel, and SAP phantom were 75 (SD=3), -378 (SD=113), -198 (SD=45) respectively. AAA dose calculation demonstrated sufficient dose buildup in all three materials. The relative surfaces doses to film were 23.7% without buildup, 87.5% with 0.5 cm bolus, 92.4% for the SAP phantom, and 87.1% for the damp towel. Conclusion: We demonstrate that superabsorbent polymers can provide sufficient dose buildup. Furthermore, due to the form in which SAPs are traditionally manufactured, this material is less expensive conforms more easily to irregular surfaces than standard sheets of bolus. Also, as a substance which is designed to absorb and retain water efficiently, SAPs are much more comfortable and more consistent than damp towels

  13. Deep reversible storage - proposition of an area of interest for an extended survey and of surface implantation scenarios

    International Nuclear Information System (INIS)

    2009-01-01

    This document first describes the approach taken for the selection of a site. It presents and discusses the implantation criteria with respect to geology and to long term safety, the technical criteria for a surface implantation (environmental and safety constraints, social and economical data, transport infrastructures). Then, it states the first propositions for different scenarios of surface and underground implantations. It gives an assessment of the dialog with local actors. It presents the ANDRA's proposition in terms of technical criteria, area of interest for an extended survey, and surface implantation scenarios to be investigated

  14. Study of 'inadvertent human intrusion or rare natural event scenarios' for sub-surface disposal of radioactive waste

    International Nuclear Information System (INIS)

    Nakatani, Takayoshi; Ishitoya, Kimihide; Funabashi, Hideyuki; Sugaya, Toshikatsu; Sone, Tomoyuki; Shimada, Hidemitsu; Nakai, Kunihiro

    2010-03-01

    Japan Atomic Energy Agency (JAEA) is making preparations for the sub-surface disposal of radioactive wastes, in an integrated fashion according to the properties of the waste material regardless of the generators or waste sources. In this study, 'Inadvertent Human Intrusion or Rare Natural Event Scenarios' of 'Three Types scenarios' was considered according to the standard of the Atomic Energy Society of Japan (AESJ) on the sub-surface disposal system that was based on 'Basic Policy for Safety Regulation Concerning Land Disposal of Low-Level Radioactive Waste (Interim Report)' by Nuclear Safety Commission of Japan (NSC). Selection of the assessed scenarios, development of the assessment tool and preliminary exposure dose assessment for general public were conducted. Among the assessed scenarios, the exposure dose of 'well water drinking scenario' was the highest under the very conservative assessment condition. This scenario assumed that the groundwater in Excavation Disturbed Zone (EDZ) was directly used as drinking water without any dilution. Although this was very conservative condition and the result exceeded 10 mSv/y, it stayed under the upper limit of standard dose value for 'Inadvertent Human Intrusion or Rare Natural Event Scenarios' (10 - 100 mSv/y). (author)

  15. From detached to attached buildup complexes

    DEFF Research Database (Denmark)

    Rafaelsen, B.; Elvebakk, G.; Andreassen, K.

    2008-01-01

    -like ridges and possibly areas with restricted circulation. Warm-water carbonate buildups, forming ridges and isolated mounds, occur in the Gipsdalen Group (latest Serpukhovian-mid-Sakmarian), where they initially grew in a detached platform setting. The carbonate buildups are several tens of kilometres long...... deposition and buildup growth bridged the detached platform with the attached platform. In the Bjarmeland Group (Lower Permian) 0.35-4.8 km wide, 1.5-27 km long and 60-420 m thick cool-water bryozoan-dominated straight, sinuous and continuous carbonate ridges or atoll-like ridges are located on top...

  16. PyECLOUD and build-up simulations at CERN

    International Nuclear Information System (INIS)

    Iadarola, G; Rumolo, G

    2013-01-01

    PyECLOUD is a newly developed code for the simulation of the electron cloud (EC) build-up in particle accelerators. Almost entirely written in Python, it is mostly based on the physical models already used in the ECLOUD code but, thanks to the implementation of new optimized algorithms, it exhibits a significantly improved performance in accuracy, speed, reliability and flexibility. Such new features of PyECLOUD have been already broadly exploited to study EC observations in the Large Hadron Collider (LHC) and its injector chain as well as for the extrapolation to high luminosity upgrade scenarios. (author)

  17. Hot ion buildup and lifetime in LITE. Final report

    International Nuclear Information System (INIS)

    1978-09-01

    An experimental investigation of hot ion buildup and lifetime in a small scale mirror device (LITE) is described. Hot ions were produced by 27 kV neutral beam injection into laser produced LiH plasmas and H plasmas produced by a washer gun. Hot H ion (12 kV) densities of approx. = 10 12 cm -3 were produced with the LiH target plasmas and densities an order of magnitude lower were produced with the washer gun target plasmas. Hot ion dominant plasmas were not achieved in LITE. The experimental measurements and subsequent analysis using numerical models of the plasma buildup indicate that in small, unshielded mirror plasmas, careful control must be maintained over the transient background gas density in the vicinity of the plasma surface. The hot ion lifetime in LITE was set by the transient cold neutral background resulting from the washer gun of reflux from the target plasma striking the adjacent surfaces

  18. Momentum management strategy during Space Station buildup

    Science.gov (United States)

    Bishop, Lynda; Malchow, Harvey; Hattis, Philip

    1988-01-01

    The use of momentum storage devices to control effectors for Space Station attitude control throughout the buildup sequence is discussed. Particular attention is given to the problem of providing satisfactory management of momentum storage effectors throughout buildup while experiencing variable torque loading. Continuous and discrete control strategies are compared and the effects of alternative control moment gyro strategies on peak momentum storage requirements and on commanded maneuver characteristics are described.

  19. Application of automation and robotics to lunar surface human exploration operations

    Science.gov (United States)

    Woodcock, Gordon R.; Sherwood, Brent; Buddington, Patricia A.; Bares, Leona C.; Folsom, Rolfe; Mah, Robert; Lousma, Jack

    1990-01-01

    Major results of a study applying automation and robotics to lunar surface base buildup and operations concepts are reported. The study developed a reference base scenario with specific goals, equipment concepts, robot concepts, activity schedules and buildup manifests. It examined crew roles, contingency cases and system reliability, and proposed a set of technologies appropriate and necessary for effective lunar operations. This paper refers readers to four companion papers for quantitative details where appropriate.

  20. Energy absorption and exposure build-up factors in teeth

    International Nuclear Information System (INIS)

    Manjunatha, H.C.; Rudraswamy, B.

    2010-01-01

    Full text: Gamma and X-radiation are widely used in medical imaging and radiation therapy. The user of radioisotopes must have knowledge about how radiation interacts with matter, especially with the human body, because when photons enter the medium/body, they degrade their energy and build up in the medium, giving rise to secondary radiation which can be estimated by a factor which is called the 'build-up factor'. It is essential to study the exposure build up factor in radiation dosimetry. G.P. fitting method has been used to compute energy absorption and exposure build-up factor of teeth (enamel outer surface (EOS), enamel middle (EM), enamel dentin junction towards enamel (EDJE), enamel dentin junction towards dentin (EDJD), dentin middle (DM) and dentin inner surface (DIS)) for wide energy range (0.015 MeV-15 MeV) up to the penetration depth of 40 mean free path. The dependence of energy absorption and exposure build up factor on incident photon energy, Penetration depth and effective atomic number has also been assessed. The relative dose distribution at a distance r from the point source is also estimated. The computed exposure and absorption build-up factors are useful to estimate the gamma and Bremsstrahlung radiation dose distribution teeth which is useful in clinical dosimetry

  1. Scenarios for global emissions from air traffic. The development of regional and gridded (5 degrees x 5 degrees) emissions scenarios for aircraft and for surface sources, based on CPB scenarios and existing emission inventories for aircraft and surface sources

    NARCIS (Netherlands)

    Olivier JGJ; LAE

    1995-01-01

    An estimate was made of present global emissions from air traffic using statistical information on fuel consumption, aircraft types and applying emission factors for various compounds. To generate scenarios for future emissions from air traffic, assumptions were used regarding the development of the

  2. Safety assessment on the human intrusion scenarios of near surface disposal facility for low and very low level radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Sung Wook; Park, Jin Baek [Korea Radioactive Waste Agency, Daejeon (Korea, Republic of); Park, Sang Ho [Chungnam National University, Daejeon (Korea, Republic of)

    2016-03-15

    The second-stage near surface disposal facility for low and very low level radioactive waste's permanent disposal is to be built. During the institutional control period, the inadvertent intrusion of the general public is limited. But after the institutional control period, the access to the general public is not restricted. Therefore human who has purpose of residence and resource exploration can intrude the disposal facility. In this case, radioactive effects to the intruder should be limited within regulatory dose limits. This study conducted the safety assessment of human intrusion on the second-stage surface disposal facility through drilling and post drilling scenario. Results of drilling and post drilling scenario were satisfied with regulatory dose limits. The result showed that post-drilling scenario was more significant than drilling scenario. According to the human intrusion time and behavior after the closure of the facility, dominant radionuclide contributing to the intruder was different. Sensitivity analyses on the parameters about the human behavior were also satisfied with regulatory dose limits. Especially, manual redistribution factor was the most sensitive parameter on exposure dose. A loading plan of spent filter waste and dry active waste was more effective than a loading plan of spent filter waste and other wastes for the radiological point of view. These results can be expected to provide both robustness and defense in depth for the development of safety case further.

  3. Definition of intrusion scenarios and example concentration ranges for the disposal of near-surface waste at the Hanford Site

    International Nuclear Information System (INIS)

    Aaberg, R.L.; Kennedy, W.E. Jr.

    1990-10-01

    The US Department of Energy (DOE) is in the process of conducting performance assessments of its radioactive waste sites and disposal systems to ensure that public health and safety are protected, the environment is preserved, and that no remedial actions after disposal are required. Hanford Site low-level waste performance assessments are technical evaluations of waste sites or disposal systems that provide a basis for making decisions using established criteria. The purpose of this document is to provide a family of scenarios to be considered when calculating radionuclide exposure to individuals who may inadvertently intrude into near-surface waste disposal sites. Specific performance assessments will use modifications of the general scenarios described here to include additional site/system details concerning the engineering design, waste form, inventory, and environmental setting. This document also describes and example application of the Hanford-specific scenarios in the development of example concentration ranges for the disposal of near-surface wastes. The overall goal of the example calculations is to illustrate the application of the scenarios in a performance assessment to assure that people in the future cannot receive a dose greater than an established limit. 24 refs., 2 figs., 5 tabs

  4. Am-241 buildup in nematode organisms

    International Nuclear Information System (INIS)

    Martyushov, V.Z.; Tarasov, O.V.

    1990-01-01

    The process of Am-241 intake into earthworm organisms from chernozem leached in their presence in soil contaminated with this radionuclide is studied. The data on Am-241 buildup values during long-time radionuclide intake into earthworm organisms from soil are given. It s shown that Am-241 buildup in earthworm organisms do not exceed its concentration in soil for the whole observation period (as Am-241 presents in soil in state unavailable for animals). Intensive extraction of the radionuclide from the organisms is observed when earthworm contacts with soil are stopped

  5. Determination of contamination-free build-up for 60Co

    International Nuclear Information System (INIS)

    Higgins, P.D.; Sibata, CH.; Paliwal, B.R.

    1985-01-01

    Experimental verification of the difference between absorbed dose in tissue and the collision fraction of kerma requires precise knowledge of the absorbed dose curve, particularly in the build-up and build-down regions. A simple method from direct measurement of contamination-free build-up for 60 Co, which should also be applicable for most of the photon energies commonly employed for treatment, is presented. It is shown that the contribution from air-scattered electrons to the surface dose may be removed by extrapolating measurements of build-up to zero field size. The remaining contribution to contamination from the collimators and other source-related hardware may be minimised by measuring these build-up curves sufficiently far from the source. These results were tested by measuring the build-up using a magnet to sweep scattered electrons from the primary photon beam and by measuring the surface dose in the limit of an evacuated beam path. The relative dose at zero depth in polystyrene was found to be approximately 8.9+-0.3% of the dose at the depth of maximum build-up. (author)

  6. Dose determination on buildup region using photodiodes

    International Nuclear Information System (INIS)

    Khoury, H.J.; Lopes, F.J.; Melo, F. de A.

    1989-01-01

    A clinical dosemeter using photodiode BPW-34 was developed, allowing the determination of dose on buildup region. The measures were made with X-rays beam of linear accelerator and with gamma radiation of cobalt 60. The results were compared with others made in a ionization chamber. (C.G.C.) [pt

  7. Photon buildup factors of some chemotherapy drugs.

    Science.gov (United States)

    Kavaz, Esra; Ahmadishadbad, Nader; Özdemir, Yüksel

    2015-02-01

    Everyday more and more people are diagnosed with some form of cancer. Some are treatable with chemotherapy alone, while others need radiotherapy and occasionally surgery. Recently, concurrent administration of chemotherapy and radiotherapy has been increasingly used in cancer treatment, leading to improvements in survival as well as quality of life. Accordingly, interaction of chemotherapy drugs with radiation will be meaningful to examine. In the present study, gamma ray energy absorption and exposure of buildup factors were computed using the five-parameter geometric progression (G-P) fitting formula for some chemotherapy drugs in the energy range 0.015-15 MeV, and for penetration depths up to 40 mean free path (mfp). The generated energy absorption (EABF) and exposure buildup factors (EBF) of chemotherapy drugs have been studied as a function of penetration depth and incident photon energy. The significant variations in EABF and EBF for chemotherapy drugs have been observed at the moderate energy region. It has been concluded that the buildup of photons is less in azathioprine and is more in vinblastine compared with other drugs. Buildup factors investigated in the present work could be useful in radiation dosimetry and therapy. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  8. Research on Land Surface Thermal-Hydrologic Exchange in Southern China under Future Climate and Land Cover Scenarios

    Directory of Open Access Journals (Sweden)

    Jianwu Yan

    2013-01-01

    Full Text Available Climate change inevitably leads to changes in hydrothermal circulation. However, thermal-hydrologic exchanging caused by land cover change has also undergone ineligible changes. Therefore, studying the comprehensive effects of climate and land cover changes on land surface water and heat exchanges enables us to well understand the formation mechanism of regional climate and predict climate change with fewer uncertainties. This study investigated the land surface thermal-hydrologic exchange across southern China for the next 40 years using a land surface model (ecosystem-atmosphere simulation scheme (EASS. Our findings are summarized as follows. (i Spatiotemporal variation patterns of sensible heat flux (H and evapotranspiration (ET under the land cover scenarios (A2a or B2a and climate change scenario (A1B are unanimous. (ii Both H and ET take on a single peak pattern, and the peak occurs in June or July. (iii Based on the regional interannual variability analysis, H displays a downward trend (10% and ET presents an increasing trend (15%. (iv The annual average H and ET would, respectively, increase and decrease by about 10% when woodland converts to the cultivated land. Through this study, we recognize that land surface water and heat exchanges are affected greatly by the future climate change as well as land cover change.

  9. Projected shifts in copepod surface communities in the Mediterranean Sea under several climate change scenarios

    Science.gov (United States)

    Benedetti, F.; Guilhaumon, F.; Adloff, F.; Irisson, J. O.; Ayata, S. D.

    2016-02-01

    Although future increases in water temperature and future changes in regional circulation are expected to have great impacts on the pelagic food-web, estimates focusing on community-level shifts are still lacking for the planktonic compartment. By combining statistical niche models (or species distribution models) with projections from a regional circulation model, the impact of climate change on copepod epipelagic communities is assessed for the Mediterranean Sea. Habitat suitability maps are generated for 106 of the most abundant copepod species to analyze emerging patterns of diversity at the community level. Using variance analysis, we also quantified the uncertainties associated to our modeling strategy (niche model choice, CO2 emission scenario, boundary forcings of the circulation model). Comparing present and future projections, changes in species richness (alpha diversity) and in community composition (beta diversity, decomposed into turnover and nestedness component) are calculated. Average projections show that copepod communities will mainly experience turn-over processes, with little changes in species richness. Species gains are mainly located in the Gulf of Lions, the Northern Adriatic and the Northern Aegean seas. However, projections are highly variable, especially in the Eastern Mediterranean basin. We show that such variability is mainly driven by the choice of the niche model, through interactions with the CO2 emission scenario or the boundary forcing of the circulation model can be locally important. Finally, the possible impact of the estimated community changes on zooplanktonic functional and phylogenetic diversity is also assessed. We encourage the enlargement of this type of study to other components of the pelagic food-web, and argue that niche models' outputs should always be given along with a measure of uncertainty, and explained in light of a strong theoretical background.

  10. Surface disinfection tests with Salmonella and a putative indicator bacterium, mimicking worst-case scenarios in poultry houses

    DEFF Research Database (Denmark)

    Gradel, K.O.; Sayers, A.R.; Davies, R.H.

    2004-01-01

    Surface disinfection studies mimicking worst-case scenarios in badly cleaned poultry houses were made with 3 bacterial isolates (Salmonella enteritidis, Salmonella senftenberg, and Enterococcus faecalis), and 3 1% disinfectant solutions, formaldehyde (F; 24.5% vol/vol), glutaraldehyde...... hard water, except when feed chain links with fats were disinfected using 30degreesC before and after disinfection, for which the peroxygen compound seemed more effective. Enterococcus faecalis was equally or less susceptible than S. enteritidis and S. senftenberg, indicating its suitability...... as an indicator bacterium. For the peroxygen compound, S. senftenberg was more susceptible than S. enteritidis in spite of higher minimum inhibitory concentrations to this disinfectant for the former....

  11. Electron-Cloud Build-Up: Summary

    International Nuclear Information System (INIS)

    Furman, M.A.

    2007-01-01

    I present a summary of topics relevant to the electron-cloud build-up and dissipation that were presented at the International Workshop on Electron-Cloud Effects 'ECLOUD 07' (Daegu, S. Korea, April 9-12, 2007). This summary is not meant to be a comprehensive review of the talks. Rather, I focus on those developments that I found, in my personal opinion, especially interesting. The contributions, all excellent, are posted in http://chep.knu.ac.kr/ecloud07/

  12. Surface ozone scenario at Pune and Delhi during the decade of 1990s

    Indian Academy of Sciences (India)

    and the climate change as one of the green house gases. It comes into direct .... Pune is one of the highly polluted cities in India. The pollution in this ... cities in India. The pollution in this city is caused mainly by numerous industrial and vehicular activities in and around the city area. 3. Data and methodology. Surface ozone ...

  13. The Dose Assessment in the Vault Test Case of Near-Surface Disposal Facility for Drinking Water Scenario

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Hyoung; Choi, Byung Seon; Moon, Jei Kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Park, Jae Woo [Jeju National University, Jeju (Korea, Republic of)

    2012-05-15

    It is generally accepted that the radionuclides contained in the radioactive wastes will be eventually released and these will be transported to the accessible environment (near-field, far-field, biosphere). Therefore, the long-term safety assessment of near-surface radioactive waste disposal should be required by modeling the expected release of radionuclides from the repository, far-field area, and biosphere. Finally, the effective dose rate should be estimated through the released radionuclides. In this study, the radiological dose was evaluated for the reference near-surface radioactive waste disposal facility in Vaalputs, South Africa, which has been selected as a part of IAEA coordinated research program on improvement of safety assessment methodologies(ISAM). The assessment of radiological dose was performed for drinking water scenario from a well. The release and transport of radionuclides in disposal system were simulated by GoldSim. This approach suggested the time variation of effective dose over long-term period. And the results from this approach were compared with another approach method for the same facility and scenario

  14. The Dose Assessment in the Vault Test Case of Near-Surface Disposal Facility for Drinking Water Scenario

    International Nuclear Information System (INIS)

    Kim, Tae Hyoung; Choi, Byung Seon; Moon, Jei Kwon; Park, Jae Woo

    2012-01-01

    It is generally accepted that the radionuclides contained in the radioactive wastes will be eventually released and these will be transported to the accessible environment (near-field, far-field, biosphere). Therefore, the long-term safety assessment of near-surface radioactive waste disposal should be required by modeling the expected release of radionuclides from the repository, far-field area, and biosphere. Finally, the effective dose rate should be estimated through the released radionuclides. In this study, the radiological dose was evaluated for the reference near-surface radioactive waste disposal facility in Vaalputs, South Africa, which has been selected as a part of IAEA coordinated research program on improvement of safety assessment methodologies(ISAM). The assessment of radiological dose was performed for drinking water scenario from a well. The release and transport of radionuclides in disposal system were simulated by GoldSim. This approach suggested the time variation of effective dose over long-term period. And the results from this approach were compared with another approach method for the same facility and scenario

  15. Efforts to control radiation build-up in Ringhals

    Energy Technology Data Exchange (ETDEWEB)

    Egner, K.; Aronsson, P.O.; Erixon, O. [Vattenfall AB, Vaeroebacka (Sweden)

    1995-03-01

    It is well known that good control of the primary chemistry in a PWR is essential in order to minimize material problems and fuel damages. It has also been well established that the water chemistry has a great influence on accumulation of corrosion products on the fuel and the radiation build-up on primary system surfaces. Ringhals was one of the pioneers to increase operating pH in order to reduce radiation build-up and has now been operating for ten years with pH at 7.4 or (in later years) 7.2. Our experience is favourable and includes low radiation levels in the new (1989) steam generators of Ringhals 2. Ringhals 4 has operated almost its whole life at pH 7.2 or higher and it remains one of the cleanest PWRs of its vintage. In addition to strict adherence to a stable operating chemistry, Ringhals is now working on a program with the aim to find optimum shut-down and start-up chemistry to reduce activity levels in the primary systems. A particular goal is to use the shut-down and start-up chemistry at the 1994 outage in Ringhals 3 in order to reduce doserates in preparation for the planned steam generator replacement in 1995. The paper summarizes the experience to date of the established operating chemistry, on-going tests with modified shut-down and start-up chemistry and other measures to limit or reduce the activity build-up.

  16. Efforts to control radiation build-up in Ringhals

    International Nuclear Information System (INIS)

    Egner, K.; Aronsson, P.O.; Erixon, O.

    1995-01-01

    It is well known that good control of the primary chemistry in a PWR is essential in order to minimize material problems and fuel damages. It has also been well established that the water chemistry has a great influence on accumulation of corrosion products on the fuel and the radiation build-up on primary system surfaces. Ringhals was one of the pioneers to increase operating pH in order to reduce radiation build-up and has now been operating for ten years with pH at 7.4 or (in later years) 7.2. Our experience is favourable and includes low radiation levels in the new (1989) steam generators of Ringhals 2. Ringhals 4 has operated almost its whole life at pH 7.2 or higher and it remains one of the cleanest PWRs of its vintage. In addition to strict adherence to a stable operating chemistry, Ringhals is now working on a program with the aim to find optimum shut-down and start-up chemistry to reduce activity levels in the primary systems. A particular goal is to use the shut-down and start-up chemistry at the 1994 outage in Ringhals 3 in order to reduce doserates in preparation for the planned steam generator replacement in 1995. The paper summarizes the experience to date of the established operating chemistry, on-going tests with modified shut-down and start-up chemistry and other measures to limit or reduce the activity build-up

  17. Pesticide exposure assessment for surface waters in the EU. Part 2: Determination of statistically based run-off and drainage scenarios for Germany.

    Science.gov (United States)

    Bach, Martin; Diesner, Mirjam; Großmann, Dietlinde; Guerniche, Djamal; Hommen, Udo; Klein, Michael; Kubiak, Roland; Müller, Alexandra; Preuss, Thomas G; Priegnitz, Jan; Reichenberger, Stefan; Thomas, Kai; Trapp, Matthias

    2017-05-01

    In order to assess surface water exposure to active substances of plant protection products (PPPs) in the European Union (EU), the FOCUS (FOrum for the Co-ordination of pesticide fate models and their USe) surface water workgroup introduced four run-off and six drainage scenarios for Step 3 of the tiered FOCUSsw approach. These scenarios may not necessarily represent realistic worst-case situations for the different Member States of the EU. Hence, the suitability of the scenarios for risk assessment in the national authorisation procedures is not known. Using Germany as an example, the paper illustrates how national soil-climate scenarios can be developed to model entries of active substances into surface waters from run-off and erosion (using the model PRZM) and from drainage (using the model MACRO). In the authorisation procedure for PPPs on Member State level, such soil-climate scenarios can be used to determine exposure endpoints with a defined overall percentile. The approach allows the development of national specific soil-climate scenarios and to calculate percentile-based exposure endpoints. The scenarios have been integrated into a software tool analogous to FOCUS-SWASH which can be used in the future to assess surface water exposure in authorisation procedures of PPPs in Germany. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

  18. Zinc injection helps reduce radiation field buildup in BWRs

    International Nuclear Information System (INIS)

    Wood, C.

    1991-01-01

    The injection of zinc into the reactor water of BWRs (Boiling Water Reactors) was a technique developed by General Electric (GE) and the Electric Power Research Institute (EPRI) to control the buildup of radiation fields from cobalt-60 on out-of-core piping. The presence of 5-10ppb zinc in the reactor water reduces the growth of oxide films on stainless steel surfaces, thereby reducing the number of sites available for the incorporation of cobalt; zinc also competes with cobalt for the sites. In September 1990, EPRI organized a workshop at the request of several US utilities to provide a forum to discuss experiences with zinc injection. The meeting focused on six main issues: the effect of zinc on radiation fields in normal water chemistry; the radiation buildup in hydrogen water chemistry, with and without zinc; the effects of zinc-65; the corrosion of fuel cladding and structural materials; the performance of zinc injection and monitoring equipment; and planning for zinc injection. (author)

  19. Build-up and management of transuranium

    International Nuclear Information System (INIS)

    Uematsu, Kunihiko

    1984-01-01

    About 17,000,000 kW is generated by nuclear power station at present and this figure correspond to 20 % of total power generation in Japan, and is expected to increase year after year. Following the increase of power generation, build-up of Transuraium from nuclear power station will increase as a matter of course. In 2,000 AD; the build-up of Pu and TPu is expected to reach up to 200 T(TPu = 24 T). Effective management of TPu build-up is now an urgent problem Recycling of Pu and TPu including LWR-Pu recycling, ATR-Pu recycling and FBR-Pu recycling were investigated. In LWR-Pu recycling, recycling quantities of Pu and TPu, and generation of power increase following the repetition of recycling. In ATR-Pu recycling, the increase of TPu following recycling is more remakable than that of LWR-Pu recycling. On the contrary, in FBR-Pu recycling, TPu decreases following the repetition of recycling. The decrease of TPu is thought to be caused by extinction effect in FBR. All of these recycling are suitable for the utilization of Pu, but FBR-Pu recycling is most effective for utilization of Pu and decrease of TPu. Accordingly, when LWR or ATR recycling is applied, Pu shall be transferred to FBR after 1 - 2 recycling. For long-term management of TPu, recycling is not sufficient and some positive method such as oxtinction by strong neutron source like proton linear accelerator is necessary. Fundamental researches on nuclear fuel cycle, nuclide separation method and extinction process of TPu must be carried out. (Ishimitsu, A.)

  20. Future Changes in Surface Runoff over Korea Projected by a Regional Climate Model under A1B Scenario

    Directory of Open Access Journals (Sweden)

    Ji-Woo Lee

    2014-01-01

    Full Text Available This study assesses future change of surface runoff due to climate change over Korea using a regional climate model (RCM, namely, the Global/Regional Integrated Model System (GRIMs, Regional Model Program (RMP. The RMP is forced by future climate scenario, namely, A1B of Intergovernmental Panel on Climate Change (IPCC Fourth Assessment Report (AR4. The RMP satisfactorily reproduces the observed seasonal mean and variation of surface runoff for the current climate simulation. The distribution of monsoonal precipitation-related runoff is adequately captured by the RMP. In the future (2040–2070 simulation, it is shown that the increasing trend of temperature has significant impacts on the intra-annual runoff variation. The variability of runoff is increased in summer; moreover, the strengthened possibility of extreme occurrence is detected in the future climate. This study indicates that future climate projection, including surface runoff and its variability over Korea, can be adequately addressed on the RMP testbed. Furthermore, this study reflects that global warming affects local hydrological cycle by changing major water budget components. This study adduces that the importance of runoff should not be overlooked in regional climate studies, and more elaborate presentation of fresh-water cycle is needed to close hydrological circulation in RCMs.

  1. Effects of Fallow Genealogical Cycles on the Build-up of Nutrients in ...

    African Journals Online (AJOL)

    The study examined the effect of fallow generational cycles on the buildup of nutrients in the soil. Fallow sequence of 1st, 2nd, 3rd, 4th and 5th generations were studied. The quadrat approach of sampling was employed to collect soil samples (surface and subsurface) from five plots of 10m x 10m across the five fallow ...

  2. Impacts of traffic and rainfall characteristics on heavy metals build-up and wash-off from urban roads.

    Science.gov (United States)

    Mahbub, Parvez; Ayoko, Godwin A; Goonetilleke, Ashantha; Egodawatta, Prasanna; Kokot, Serge

    2010-12-01

    An investigation into the effects of changes in urban traffic characteristics due to rapid urbanisation and the predicted changes in rainfall characteristics due to climate change on the build-up and wash-off of heavy metals was carried out in Gold Coast, Australia. The study sites encompassed three different urban land uses. Nine heavy metals commonly associated with traffic emissions were selected. The results were interpreted using multivariate data analysis and decision making tools, such as principal component analysis (PCA), fuzzy clustering (FC), PROMETHEE, and GAIA. Initial analyses established high, low, and moderate traffic scenarios as well as low, low to moderate, moderate, high, and extreme rainfall scenarios for build-up and wash-off investigations. GAIA analyses established that moderate to high traffic scenarios could affect the build-up, while moderate to high rainfall scenarios could affect the wash-off of heavy metals under changed conditions. However, in wash-off, metal concentrations in 1-75 μm fraction were found to be independent of the changes to rainfall characteristics. In build-up, high traffic activities in commercial and industrial areas influenced the accumulation of heavy metal concentrations in particulate size range from 75 - >300 μm, whereas metal concentrations in finer size range of 300 μm can be targeted for removal of Ni, Cu, Pb, Cd, Cr, and Zn from build-up, while organic matter from 300 μm can be targeted for removal of Cd, Cr, Pb, and Ni from wash-off. Cu and Zn need to be removed as free ions from most fractions in wash-off.

  3. Secondary side TSP deposit buildup: lab test investigation focused on electrokinetic considerations

    Energy Technology Data Exchange (ETDEWEB)

    Barale, M.; Guillodo, M.; Foucault, M., E-mail: Morgan.Barale@areva.com [AREVA NP SAS, Technical Centre, Le Creusot (France); Ryckelynck, N.; Clinard, M-H.; Chahma, F.; Brun, C. [AREVA NP SAS, Chemistry and Radiochemistry Group, Paris (France); Corredera, G. [Electricite de France, Centre d' Expertise et d' Inspection dans les domaines de la Realisation et de l' Exploitation, Saint-Denis (France)

    2010-07-01

    Deposit buildup which caused the clogging of the 'foils' of the upper tube-support-plates (TSP) inside a PWR steam generator of French NPPs in 2006 presents certain similarities with deposits observed in lab tests performed in secondary coolant chemistry at the Technical Centre of AREVA NP in 2002. The mechanism of TSP clogging seems not to present obvious phenomenological links with the fouling of the free span of SG since deposits buildup is quite uniform and is currently related to a surface boiling effect due to the surface heat flux. A specific mechanism could account for TSP clogging. In particular, electrokinetic effects were investigated by EDF-CEIDRE and AREVA NP SAS in the framework of a lab test program started in 2007. The electrokinetic approach is to consider that the coupling of local hydrodynamic and surface electrochemistry could lead to the formation of a very localized and heterogeneous deposit at the leading edge between both TSP and SG tubing material. Electrokinetic effects can lead to the oxidation and/or the precipitation of ferrous ions and to a variation of the electrokinetic potential which can produce strong attraction of iron oxide colloids. These electrokinetic effects are dependent of the T/H and local hydrodynamic conditions and surface electrochemistry explaining. The objective of this EDF-AREVA lab test program is to investigate the role of secondary chemistry coolant (pH, DH, N{sub 2}H{sub 4}, amine, redox) and of the nature of materials (SS, Ni base alloy) on deposit buildup. Properties of oxide surface and zeta potential of oxidized metallic materials have been also determined at temperature to understand their potential contribution on mechanism of TSP clogging in secondary side chemistry coolant. In this paper, a set of specific experiments carried out in this frame have been presented and discussed, paying particular attention to the effects of electrokinetic considerations and surface charges at oxide

  4. Secondary side TSP deposit buildup: lab test investigation focused on electrokinetic considerations

    International Nuclear Information System (INIS)

    Barale, M.; Guillodo, M.; Foucault, M.; Ryckelynck, N.; Clinard, M-H.; Chahma, F.; Brun, C.; Corredera, G.

    2010-01-01

    Deposit buildup which caused the clogging of the 'foils' of the upper tube-support-plates (TSP) inside a PWR steam generator of French NPPs in 2006 presents certain similarities with deposits observed in lab tests performed in secondary coolant chemistry at the Technical Centre of AREVA NP in 2002. The mechanism of TSP clogging seems not to present obvious phenomenological links with the fouling of the free span of SG since deposits buildup is quite uniform and is currently related to a surface boiling effect due to the surface heat flux. A specific mechanism could account for TSP clogging. In particular, electrokinetic effects were investigated by EDF-CEIDRE and AREVA NP SAS in the framework of a lab test program started in 2007. The electrokinetic approach is to consider that the coupling of local hydrodynamic and surface electrochemistry could lead to the formation of a very localized and heterogeneous deposit at the leading edge between both TSP and SG tubing material. Electrokinetic effects can lead to the oxidation and/or the precipitation of ferrous ions and to a variation of the electrokinetic potential which can produce strong attraction of iron oxide colloids. These electrokinetic effects are dependent of the T/H and local hydrodynamic conditions and surface electrochemistry explaining. The objective of this EDF-AREVA lab test program is to investigate the role of secondary chemistry coolant (pH, DH, N 2 H 4 , amine, redox) and of the nature of materials (SS, Ni base alloy) on deposit buildup. Properties of oxide surface and zeta potential of oxidized metallic materials have been also determined at temperature to understand their potential contribution on mechanism of TSP clogging in secondary side chemistry coolant. In this paper, a set of specific experiments carried out in this frame have been presented and discussed, paying particular attention to the effects of electrokinetic considerations and surface charges at oxide-solution interfaces

  5. CURRENT BUILDUP IN EMERGING SERPENTINE FLUX TUBES

    International Nuclear Information System (INIS)

    Pariat, E.; Masson, S.; Aulanier, G.

    2009-01-01

    The increase of magnetic flux in the solar atmosphere during active-region formation involves the transport of the magnetic field from the solar convection zone through the lowest layers of the solar atmosphere, through which the plasma β changes from >1 to <1 with altitude. The crossing of this magnetic transition zone requires the magnetic field to adopt a serpentine shape also known as the sea-serpent topology. In the frame of the resistive flux-emergence model, the rising of the magnetic flux is believed to be dynamically driven by a succession of magnetic reconnections which are commonly observed in emerging flux regions as Ellerman bombs. Using a data-driven, three-dimensional (3D) magnetohydrodynamic numerical simulation of flux emergence occurring in active region 10191 on 2002 November 16-17, we study the development of 3D electric current sheets. We show that these currents buildup along the 3D serpentine magnetic-field structure as a result of photospheric diverging horizontal line-tied motions that emulate the observed photospheric evolution. We observe that reconnection can not only develop following a pinching evolution of the serpentine field line, as usually assumed in two-dimensional geometry, but can also result from 3D shearing deformation of the magnetic structure. In addition, we report for the first time on the observation in the UV domain with the Transition Region and Coronal Explorer (TRACE) of extremely transient loop-like features, appearing within the emerging flux domain, which link several Ellermam bombs with one another. We argue that these loop transients can be explained as a consequence of the currents that build up along the serpentine magnetic field.

  6. An Empirical Model for Build-Up of Sodium and Calcium Ions in Small Scale Reverse Osmosis

    Directory of Open Access Journals (Sweden)

    Subriyer Nasir

    2011-05-01

    Full Text Available A simple models for predicting build-up of solute on membrane surface were formulated in this paper. The experiments were conducted with secondary effluent, groundwater and simulated feed water in small-scale of RO with capacity of 2000 L/d. Feed water used in the experiments contained varying concentrations of sodium, calcium, combined sodium and calcium. In order to study the effect of sodium and calcium ions on membrane performance, experiments with ground water and secondary effluent wastewater were also performed. Build-up of salts on the membrane surface was calculated by measuring concentrations of sodium and calcium ions in feed water permeate and reject streams using Atomic Absorption Spectrophotometer (AAS. Multiple linear regression of natural logarithmic transformation was used to develop the model based on four main parameters that affect the build-up of solute in a small scale of RO namely applied pressure, permeate flux, membrane resistance, and feed concentration. Experimental data obtained in a small scale RO unit were used to develop the empirical model. The predicted values of theoretical build-up of sodium and calcium on membrane surface were found in agreement with experimental data. The deviation in the prediction of build-up of sodium and calcium were found to be 1.4 to 10.47 % and 1.12 to 4.46%, respectively.

  7. Metal transfer and build-up in friction and cutting

    CERN Document Server

    Kuznetsov, V D

    1956-01-01

    Metal Transfer and Build-up in Friction and Cutting aims to systematize our knowledge of the metal build-up, to describe some of the investigations past and present carried out in SFTI (Tomsk), and to make an effort to explain a number of the phenomena in cutting, scratching, and sliding from the point of view of metal transfer theory. The book opens with a chapter on the temperature of the rubbing interface of two solids. This temperature is needed in order to elucidate the nature of the formation of a build-up in scratching, cutting, and sliding. Separate chapters follow on the seizure phen

  8. Dose discrepancies in the buildup region and their impact on dose calculations for IMRT fields

    International Nuclear Information System (INIS)

    Hsu, Shu-Hui; Moran, Jean M.; Chen Yu; Kulasekere, Ravi; Roberson, Peter L.

    2010-01-01

    Purpose: Dose accuracy in the buildup region for radiotherapy treatment planning suffers from challenges in both measurement and calculation. This study investigates the dosimetry in the buildup region at normal and oblique incidences for open and IMRT fields and assesses the quality of the treatment planning calculations. Methods: This study was divided into three parts. First, percent depth doses and profiles (for 5x5, 10x10, 20x20, and 30x30 cm 2 field sizes at 0 deg., 45 deg., and 70 deg. incidences) were measured in the buildup region in Solid Water using an Attix parallel plate chamber and Kodak XV film, respectively. Second, the parameters in the empirical contamination (EC) term of the convolution/superposition (CVSP) calculation algorithm were fitted based on open field measurements. Finally, seven segmental head-and-neck IMRT fields were measured on a flat phantom geometry and compared to calculations using γ and dose-gradient compensation (C) indices to evaluate the impact of residual discrepancies and to assess the adequacy of the contamination term for IMRT fields. Results: Local deviations between measurements and calculations for open fields were within 1% and 4% in the buildup region for normal and oblique incidences, respectively. The C index with 5%/1 mm criteria for IMRT fields ranged from 89% to 99% and from 96% to 98% at 2 mm and 10 cm depths, respectively. The quality of agreement in the buildup region for open and IMRT fields is comparable to that in nonbuildup regions. Conclusions: The added EC term in CVSP was determined to be adequate for both open and IMRT fields. Due to the dependence of calculation accuracy on (1) EC modeling, (2) internal convolution and density grid sizes, (3) implementation details in the algorithm, and (4) the accuracy of measurements used for treatment planning system commissioning, the authors recommend an evaluation of the accuracy of near-surface dose calculations as a part of treatment planning commissioning.

  9. Radiography simulation based on exposure buildup factors for multilayer structures

    International Nuclear Information System (INIS)

    Marinkovic, Predrag; Pesic, Milan

    2009-01-01

    Monte Carlo techniques were usually used to study the effect of scattered photons on a radiographic X-ray image. Such approach is accurate, but computer time consuming. On the other hand, the exposure buildup factors can be used as approximate and efficient assessment to account for the scattering of X-rays. This method uses the known radiography parameters to find the resulting detector exposure due to both scattered and un-collided photons. A model for radiography simulation, based on X-ray dose buildup factor, is proposed. This model includes non-uniform attenuation in voxelized object of imaging (patient body tissue). Composition of patient body is considered as a multi-layer structure. Various empirical formulas exist for multi-layer structure calculations and they all calculate multi-layer buildup factors by combining single-layer buildup factors. The proposed model is convenient in cases when more exact techniques (like Monte Carlo) are not economical. (author)

  10. Impact of regional climate change and future emission scenarios on surface O3 and PM2.5 over India

    Science.gov (United States)

    Pommier, Matthieu; Fagerli, Hilde; Gauss, Michael; Simpson, David; Sharma, Sumit; Sinha, Vinay; Ghude, Sachin D.; Landgren, Oskar; Nyiri, Agnes; Wind, Peter

    2018-01-01

    Eleven of the world's 20 most polluted cities are located in India and poor air quality is already a major public health issue. However, anthropogenic emissions are predicted to increase substantially in the short-term (2030) and medium-term (2050) futures in India, especially if no further policy efforts are made. In this study, the EMEP/MSC-W chemical transport model has been used to predict changes in surface ozone (O3) and fine particulate matter (PM2.5) for India in a world of changing emissions and climate. The reference scenario (for present-day) is evaluated against surface-based measurements, mainly at urban stations. The evaluation has also been extended to other data sets which are publicly available on the web but without quality assurance. The evaluation shows high temporal correlation for O3 (r = 0.9) and high spatial correlation for PM2.5 (r = 0.5 and r = 0.8 depending on the data set) between the model results and observations. While the overall bias in PM2.5 is small (lower than 6 %), the model overestimates O3 by 35 %. The underestimation in NOx titration is probably the main reason for the O3 overestimation in the model. However, the level of agreement can be considered satisfactory in this case of a regional model being evaluated against mainly urban measurements, and given the inevitable uncertainties in much of the input data.For the 2050s, the model predicts that climate change will have distinct effects in India in terms of O3 pollution, with a region in the north characterized by a statistically significant increase by up to 4 % (2 ppb) and one in the south by a decrease up to -3 % (-1.4 ppb). This variation in O3 is assumed to be partly related to changes in O3 deposition velocity caused by changes in soil moisture and, over a few areas, partly also by changes in biogenic non-methane volatile organic compounds.Our calculations suggest that PM2.5 will increase by up to 6.5 % over the Indo-Gangetic Plain by the 2050s. The increase over India

  11. Impact of regional climate change and future emission scenarios on surface O3 and PM2.5 over India

    Directory of Open Access Journals (Sweden)

    M. Pommier

    2018-01-01

    Full Text Available Eleven of the world's 20 most polluted cities are located in India and poor air quality is already a major public health issue. However, anthropogenic emissions are predicted to increase substantially in the short-term (2030 and medium-term (2050 futures in India, especially if no further policy efforts are made. In this study, the EMEP/MSC-W chemical transport model has been used to predict changes in surface ozone (O3 and fine particulate matter (PM2.5 for India in a world of changing emissions and climate. The reference scenario (for present-day is evaluated against surface-based measurements, mainly at urban stations. The evaluation has also been extended to other data sets which are publicly available on the web but without quality assurance. The evaluation shows high temporal correlation for O3 (r =  0.9 and high spatial correlation for PM2.5 (r =  0.5 and r =  0.8 depending on the data set between the model results and observations. While the overall bias in PM2.5 is small (lower than 6 %, the model overestimates O3 by 35 %. The underestimation in NOx titration is probably the main reason for the O3 overestimation in the model. However, the level of agreement can be considered satisfactory in this case of a regional model being evaluated against mainly urban measurements, and given the inevitable uncertainties in much of the input data.For the 2050s, the model predicts that climate change will have distinct effects in India in terms of O3 pollution, with a region in the north characterized by a statistically significant increase by up to 4 % (2 ppb and one in the south by a decrease up to −3 % (−1.4 ppb. This variation in O3 is assumed to be partly related to changes in O3 deposition velocity caused by changes in soil moisture and, over a few areas, partly also by changes in biogenic non-methane volatile organic compounds.Our calculations suggest that PM2.5 will increase by up to 6.5 % over the Indo

  12. Radiation buildup and control in BWR recirculation piping

    International Nuclear Information System (INIS)

    Meyer, W.; Wood, R.M.; Rao, T.V.; Vook, R.W.

    1987-01-01

    Boiling water nuclear reactors (BWRs) employ stainless steel (Types 304 or 316 NG) pipes in which high-purity water at temperatures of ∼ 275 0 C are circulated. Various components of the system, such as valves and bearings, often contain hard facing metal alloys such as Stellite-6. These components, along with the stainless steel tubing and feedwater, serve as sources of 59 Co. This cobalt, along with other soluble and insoluble impurities, is carried along with the circulating water to the reactor core where it is converted to radioactive 60 Co. After reentering the circulating water, the 60 Co can be incorporated into a complex corrosion layer in the form of CoCr 2 O 4 and/or CoFe 2 O 4 . The presence of even small amounts of 60 Co on the walls of BWR cooling systems is the dominant contributor to inplant radiation levels. Thus BWR owners and their agents are expending significant time and resources in efforts to reduce both the rate and amount of 60 Co buildup. The object of this research is twofold: (a) to form a thin diffusion barrier against the outward migration of cobalt from a cobalt-containing surface and (b) to prevent the growth of a 60 Co-containing corrosion film. The latter goal was the more important since most of the radioactive cobalt will originate from sources other than the stainless steel piping itself

  13. Optimum Water Chemistry in radiation field buildup control

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Chien, C. [Vallecitos Nuclear Center, Pleasanton, CA (United States)

    1995-03-01

    Nuclear utilities continue to face the challenGE of reducing exposure of plant maintenance personnel. GE Nuclear Energy has developed the concept of Optimum Water Chemistry (OWC) to reduce the radiation field buildup and minimize the radioactive waste production. It is believed that reduction of radioactive sources and improvement of the water chemistry quality should significantly reduce both the radiation exposure and radwaste production. The most important source of radioactivity is cobalt and replacement of cobalt containing alloy in the core region as well as in the entire primary system is considered the first priority to achieve the goal of low exposure and minimized waste production. A plant specific computerized cobalt transport model has been developed to evaluate various options in a BWR system under specific conditions. Reduction of iron input and maintaining low ionic impurities in the coolant have been identified as two major tasks for operators. Addition of depleted zinc is a proven technique to reduce Co-60 in reactor water and on out-of-core piping surfaces. The effect of HWC on Co-60 transport in the primary system will also be discussed.

  14. Mitigation scenario analysis: modelling the impacts of changes in agricultural management practices on surface water quality at the catchment scale

    Science.gov (United States)

    Taylor, Sam; He, Yi; Hiscock, Kevin

    2014-05-01

    Increasing human pressures on the natural environment through the demand for increased agricultural productivity have exacerbated and deteriorated water quality conditions within many environments due to an unbalancing of the nutrient cycle. As a consequence, increased agricultural diffuse water pollution has resulted in elevated concentrations of nutrients within surface water and groundwater bodies. This deterioration in water quality has direct consequences for the health of aquatic ecosystems and biodiversity, human health, and the use of water as a resource for public water supply and recreation. To mitigate these potential impacts and to meet commitments under the EU Drinking Water and Water Framework Directives, there is a need to improve our understanding of the impacts that agricultural land use and management practices have on water quality. Water quality models are one of the tools available which can be used to facilitate this aim. These simplified representations of the physical environment allow a variety of changes to be simulated within a catchment, including for example changes in agricultural land use and management practices, allowing for predictions of the impacts of those measures on water quality to be developed and an assessment to be made of their effectiveness in improving conditions. The aim of this research is to apply the water quality model SWAT (Soil and Water Assessment Tool) to the Wensum catchment (area 650 km2), situated in the East of England, to predict the impacts of potential changes in land use and land management practices on water quality as part of a process to select those measures that in combination will have the greatest potential to improve water quality. Model calibration and validation is conducted at three sites within the catchment against observations of river discharge and nitrate and total phosphorus loads at a monthly time-step using the optimisation algorithm SUFI-2 (Sequential Uncertainty Fitting Version 2

  15. Chemical composition dependence of exposure buildup factors for some polymers

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Tejbir [Department of Physics, S.D.D.I.E.T., Barwala, District Panchkula, Haryana 134 118 (India)], E-mail: tejbir.s@rediffmail.com; Kumar, Naresh [Department of Physics, Lovely Professional University, Phagwara 144 402 (India)], E-mail: naresh20dhiman@yahoo.com; Singh, Parjit S. [Department of Physics, Punjabi University, Patiala 147 002 (India)], E-mail: dr_parjit@hotmail.com

    2009-01-15

    Exposure buildup factors for some polymers such as poly-acrylo-nitrile (PAN), poly-methyl-acrylate (PMA), poly-vinyl-chloride (PVC), synthetic rubber (SR), tetra-fluro-ethylene (Teflon) have been computed using the G.P. fitting method in the energy range of 0.015-15.0 MeV, up to the penetration of 40 mean free paths (mfp). The variation of exposure buildup factors for all the selected polymers with incident photon energy at the fixed penetration depths has been studied, mainly emphasizing on chemical composition (equivalent atomic number) of the selected polymers. It has been observed that for the lower penetration depths (below 10 mfp), the exposure buildup factor decreases with the increase in equivalent atomic number of the selected polymers at all the incident photon energies. However, at the penetration depth of 10 mfp and incident photon energy above 3 MeV, the exposure buildup factor becomes almost independent of the equivalent atomic number of the selected polymers. Further, above the fixed penetration depth of 15 mfp of the selected polymers and above the incident photon energy of 3 MeV, reversal in the trend has been observed, i.e., the exposure buildup factor increases with the increase in equivalent atomic number.

  16. Chemical composition dependence of exposure buildup factors for some polymers

    International Nuclear Information System (INIS)

    Singh, Tejbir; Kumar, Naresh; Singh, Parjit S.

    2009-01-01

    Exposure buildup factors for some polymers such as poly-acrylo-nitrile (PAN), poly-methyl-acrylate (PMA), poly-vinyl-chloride (PVC), synthetic rubber (SR), tetra-fluro-ethylene (Teflon) have been computed using the G.P. fitting method in the energy range of 0.015-15.0 MeV, up to the penetration of 40 mean free paths (mfp). The variation of exposure buildup factors for all the selected polymers with incident photon energy at the fixed penetration depths has been studied, mainly emphasizing on chemical composition (equivalent atomic number) of the selected polymers. It has been observed that for the lower penetration depths (below 10 mfp), the exposure buildup factor decreases with the increase in equivalent atomic number of the selected polymers at all the incident photon energies. However, at the penetration depth of 10 mfp and incident photon energy above 3 MeV, the exposure buildup factor becomes almost independent of the equivalent atomic number of the selected polymers. Further, above the fixed penetration depth of 15 mfp of the selected polymers and above the incident photon energy of 3 MeV, reversal in the trend has been observed, i.e., the exposure buildup factor increases with the increase in equivalent atomic number

  17. Scenario planning.

    Science.gov (United States)

    Enzmann, Dieter R; Beauchamp, Norman J; Norbash, Alexander

    2011-03-01

    In facing future developments in health care, scenario planning offers a complementary approach to traditional strategic planning. Whereas traditional strategic planning typically consists of predicting the future at a single point on a chosen time horizon and mapping the preferred plans to address such a future, scenario planning creates stories about multiple likely potential futures on a given time horizon and maps the preferred plans to address the multiple described potential futures. Each scenario is purposefully different and specifically not a consensus worst-case, average, or best-case forecast; nor is scenario planning a process in probabilistic prediction. Scenario planning focuses on high-impact, uncertain driving forces that in the authors' example affect the field of radiology. Uncertainty is the key concept as these forces are mapped onto axes of uncertainty, the poles of which have opposed effects on radiology. One chosen axis was "market focus," with poles of centralized health care (government control) vs a decentralized private market. Another axis was "radiology's business model," with one pole being a unified, single specialty vs a splintered, disaggregated subspecialty. The third axis was "technology and science," with one pole representing technology enabling to radiology vs technology threatening to radiology. Selected poles of these axes were then combined to create 3 scenarios. One scenario, termed "entrepreneurialism," consisted of a decentralized private market, a disaggregated business model, and threatening technology and science. A second scenario, termed "socialized medicine," had a centralized market focus, a unified specialty business model, and enabling technology and science. A third scenario, termed "freefall," had a centralized market focus, a disaggregated business model, and threatening technology and science. These scenarios provide a range of futures that ultimately allow the identification of defined "signposts" that can

  18. Buildup of gamma ray photons in flyash concretes: A study

    International Nuclear Information System (INIS)

    Singh, Sukhpal; Ghumman, S.S.; Singh, Charanjeet; Thind, Kulwant Singh; Mudahar, Gurmel S.

    2010-01-01

    The gamma ray buildup factors of flyash concretes have been calculated by using Geometrical Progression formula in the energy region of 0.015-15 MeV as well as up to a penetration depth of 40 mean free paths, and have been studied as a function of incident photon energy. From the obtained results it is seen that for a fixed penetration depth the values of buildup factor are very large in the medium energy region and are small in the low and high energy regions. The results have been shown graphically.

  19. Defining context-specific scenarios to design vegetated buffer zones that limit pesticide transfer via surface runoff.

    Science.gov (United States)

    Carluer, N; Lauvernet, C; Noll, D; Munoz-Carpena, R

    2017-01-01

    When used in addition to environmentally friendly cultural practices, buffer zones can limit the water transfer of pollutants, in particular pesticides, towards water resources. The choice of the buffer zones' type and positioning, considering water pathways and flow components, is crucial. When this choice has been performed, buffer zones dimensions must still be optimized, according to the environment characteristics, which strongly influence their effectiveness. This article presents a method and its associated tools, including VFSMOD model, which aim at optimizing vegetative buffer zones (VFS) sizes, by simulating their transfer mitigation effectiveness. A first application of this methodology is illustrated on a small agricultural watershed in Brittany. A second application, based on the simulation of a large number of scenarios, leads to the elaboration of nomograms. They allow optimizing VFS size in a simpler way from the user's point of view. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Scenario? Guilty!

    DEFF Research Database (Denmark)

    Kyng, Morten

    1992-01-01

    Robert Campbell categorizes the word "scenario" as a buzzword, identifies four major uses within HCI and suggests that we adopt new terms differentiating these four uses of the word. My first reaction to reading the article was definitely positive, but rereading it gave me enough second thoughts...... to warrant a response. I should probably confess that I searched my latest paper for the word "scenario" and found eight occurrences, none of which fell in the categories described by Campbell....

  1. Understanding the build-up of SMBH and Galaxies

    Science.gov (United States)

    Carrera, Francisco; Georgakakis, Antonis; Ueda, Yoshihiro; Akylas, Thanassis; Lanzuisi, Giorgio; Castello, N.

    2015-09-01

    One of the main open questions in modern Astrophysics is understanding the coupled growth of supermassive black holes by accretion and their host galaxies via star formation, from their peak at redshifts z~ 1-4 to the present time. The generic scenario proposed involves an early phase of intense black hole growth that takes place behind large obscuring columns of inflowing dust and gas clouds. It is postulated that this is followed by a blow-out stage during which some form of AGN feedback controls the fate of the interstellar medium and hence, the evolution of the galaxy. X-rays are essential for testing this scenario as they uniquely probe AGN at both the early heavily obscured stage and the later blow-out phase. X-ray spectral analysis can identify the smoking gun evidence of heavily obscured black hole growth (e.g. intense iron Kalpha line). It therefore provides the most robust method for compiling clean samples of deeply shrouded AGN with well-defined selection functions and unbiased determinations of their intrinsic properties (accretion luminosity, obscuring column). X-rays are also the best window for studying in detail AGN feedback. This process ultimately originates in the innermost regions close to the supermassive black hole and is dominated, in terms of energy and mass flux, by highly ionised material that remains invisible at other wavelengths. The most important epoch for investigating the relation between AGN and galaxies is the redshift range z~1-4, when most black holes and stars we see in the present-day Universe were put in place. Unfortunately, exhaustive efforts with current high-energy telescopes only scrape the tip of the iceberg of the most obscured AGN population. Moreover, Xray studies of the incidence, nature and energetics of AGN feedback are limited to the local Universe. The Athena observatory will provide the technological leap required for a breakthrough in our understanding of AGN and galaxy evolution at the heyday of the Universe

  2. Damage buildup and edge dislocation mobility in equiatomic multicomponent alloys

    Energy Technology Data Exchange (ETDEWEB)

    Granberg, F., E-mail: fredric.granberg@helsinki.fi [Department of Physics, P.O. Box 43, FIN-00014 University of Helsinki (Finland); Djurabekova, F. [Department of Physics, P.O. Box 43, FIN-00014 University of Helsinki (Finland); Helsinki Institute of Physics, P.O. Box 43, FIN-00014 University of Helsinki (Finland); Levo, E.; Nordlund, K. [Department of Physics, P.O. Box 43, FIN-00014 University of Helsinki (Finland)

    2017-02-15

    Highlights: • We studied the damage buildup in equiatomic multicomponent alloys by MD simulations. • Edge dislocation mobility was lower in the studied alloys compared to elemental Ni. • Damage buildup in alloys saturated at lower levels than in elemental Ni. • Initial damage buildup is faster in alloys compared to elemental Ni. - Abstract: A new class of single phase metal alloys of equal atomic concentrations has shown very promising mechanical properties and good corrosion resistance. Moreover, a significant reduction in damage accumulation during prolonged irradiation has also been observed in these equiatomic multicomponent alloys. A comparison of elemental Ni with the two component NiFe- and the three component NiCoCr-alloy showed a substantial reduction in damage in both alloys, and an even larger difference was seen if only larger clusters were considered. One of the factors limiting the damage build-up in the alloys compared to the elemental material was seen to be dislocation mobility (Granberg et al., 2016). In this Article, we focus on a more thorough investigation of the mobility of edge dislocations in different cases of the Ni-, NiFe- and NiCoCr-samples. We find that even though the saturated amount of defects in the alloys is lower than in elemental Ni, the defect buildup in the early stages is faster in the alloys. We also find that the dislocation mobility in NiFe is lower than in Ni, at low stresses, and that the onset stress in NiFe is higher than in Ni. The same phenomenon was seen in comparison between NiFe and NiCoCr, since the three component alloy had lower dislocation mobility and higher onset stress. The dislocation velocity in elemental Ni plateaued out just under the forbidden velocity, whereas the alloys showed a more complex behaviour.

  3. Improved SVR Model for Multi-Layer Buildup Factor Calculation

    International Nuclear Information System (INIS)

    Trontl, K.; Pevec, D.; Smuc, T.

    2006-01-01

    The accuracy of point kernel method applied in gamma ray dose rate calculations in shielding design and radiation safety analysis is limited by the accuracy of buildup factors used in calculations. Although buildup factors for single-layer shields are well defined and understood, buildup factors for stratified shields represent a complex physical problem that is hard to express in mathematical terms. The traditional approach for expressing buildup factors of multi-layer shields is through semi-empirical formulas obtained by fitting the results of transport theory or Monte Carlo calculations. Such an approach requires an ad-hoc definition of the fitting function and often results with numerous and usually inadequately explained and defined correction factors added to the final empirical formula. Even more, finally obtained formulas are generally limited to a small number of predefined combinations of materials within relatively small range of gamma ray energies and shield thicknesses. Recently, a new approach has been suggested by the authors involving one of machine learning techniques called Support Vector Machines, i.e., Support Vector Regression (SVR). Preliminary investigations performed for double-layer shields revealed great potential of the method, but also pointed out some drawbacks of the developed model, mostly related to the selection of one of the parameters describing the problem (material atomic number), and the method in which the model was designed to evolve during the learning process. It is the aim of this paper to introduce a new parameter (single material buildup factor) that is to replace the existing material atomic number as an input parameter. The comparison of two models generated by different input parameters has been performed. The second goal is to improve the evolution process of learning, i.e., the experimental computational procedure that provides a framework for automated construction of complex regression models of predefined

  4. Current scenario

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Current scenario. India , like other parts of the world, is also facing the problem of increase in the incidence of drug resistance in tuberculosis. Multi-drug resistance (MDR, resistance to RIF & INH) and extensively drug resistant strains (X-DR, resistance to RIF, INH, FQs ...

  5. Impact of eccentricity build-up and graveyard disposal Strategies on MEO navigation constellations

    Science.gov (United States)

    Radtke, Jonas; Domínguez-González, Raúl; Flegel, Sven K.; Sánchez-Ortiz, Noelia; Merz, Klaus

    2015-12-01

    the second disposal strategy on all payloads from all MEO navigation constellations are investigated. Long-term simulations over 200 years of the overall space debris environment using the tool LUCA (Long-Term Utility for Collision Analysis) are performed. Furthermore, a reference scenario was implemented. This reference scenario mimics the disposal strategies used up to the current date by active constellations (GPS and GLONASS), and proposes similar approaches for the future constellations (Galileo and BeiDou). The results of these simulations are analysed with regard to flux and collision probabilities. To this end, intra-constellation impacts between disposed and active satellites are shown, as well as inter-constellation impacts between disposed satellites from other constellations and active payloads. Additionally, the impact of eccentricity build-up disposal on other orbital regimes such as LEO and GEO is analysed. For all performed analyses, a special focus is put on the Galileo constellation.

  6. Resistência à remoção por tração de coroas totais metálicas cimentadas em dentes com e sem reconstrução coronária Tensile strength of metal crowns cemented on dental and buildup surfaces

    Directory of Open Access Journals (Sweden)

    Eduardo Batista FRANCO

    1999-12-01

    C, 37°C and 55°C, and later subjected to tensile tests in a Universal Kratos testing machine. The results obtained were submitted to ANOVA, showing statistically significant differences (5% between the distinct conditions studied. Regarding the teeth without reconstruction, we verified improved results of Ketac-Cem when using polyacrylic acid. The teeth reconstructed with Vitremer did not show significant statistical difference between the two cementing agents. The reconstruction of teeth buildup surfaces did not hinder the retentiveness of the metal crowns.

  7. Quality of USMC Officers: Buildup Vs. Reduction in Forces

    Science.gov (United States)

    2016-03-01

    the system and difficult to remove. Bacolod (2007), analyzes the decline in teacher quality due to expanded access to professional jobs for women ...display diminishing returns or contributions to an officer’s quality , productivity, job performance, or output. The FITREP is designed for the RS to take...minus FY Average of RS Highs between the Buildup and Drawdown An alternative measure of officer quality based on their job performance is the difference

  8. Humidity Buildup in Electronic Enclosures Exposed to Constant Conditions

    DEFF Research Database (Denmark)

    Conseil, Helene; Staliulionis, Zygimantas; Jellesen, Morten Stendahl

    2017-01-01

    Electronic components and devices are exposed to a wide variety of climatic conditions, therefore the protection of electronic devices from humidity is becoming a critical factor in the system design. The ingress of moisture into typical electronic enclosures has been studied with defined paramet....... The moisture buildup inside the enclosure has been simulated using an equivalent RC circuit consisting of variables like controlled resistors and capacitors to describe the diffusivity, permeability, and storage in polymers....

  9. BUILDUP OF PROACTIVE INTERFERENCE IN JAPANESE KANJI LEARNING

    OpenAIRE

    FUJITA, Tadashi

    1995-01-01

    The discriminative assumption on buildup of proactive interference in short-term memory predicts that when intertrial similarity of items is high, the proactive interference is built up while interlist similarity of items is low, the proactive interference is not built up. To test the discriminative assumption in Japanese Kanji learning, intertrial similarity was changed by the acoustic, the radical (as one of the figurative properties), and the radical plus semantic properties in Kanji. For ...

  10. Uncertainty analysis of pollutant build-up modelling based on a Bayesian weighted least squares approach

    International Nuclear Information System (INIS)

    Haddad, Khaled; Egodawatta, Prasanna; Rahman, Ataur; Goonetilleke, Ashantha

    2013-01-01

    Reliable pollutant build-up prediction plays a critical role in the accuracy of urban stormwater quality modelling outcomes. However, water quality data collection is resource demanding compared to streamflow data monitoring, where a greater quantity of data is generally available. Consequently, available water quality datasets span only relatively short time scales unlike water quantity data. Therefore, the ability to take due consideration of the variability associated with pollutant processes and natural phenomena is constrained. This in turn gives rise to uncertainty in the modelling outcomes as research has shown that pollutant loadings on catchment surfaces and rainfall within an area can vary considerably over space and time scales. Therefore, the assessment of model uncertainty is an essential element of informed decision making in urban stormwater management. This paper presents the application of a range of regression approaches such as ordinary least squares regression, weighted least squares regression and Bayesian weighted least squares regression for the estimation of uncertainty associated with pollutant build-up prediction using limited datasets. The study outcomes confirmed that the use of ordinary least squares regression with fixed model inputs and limited observational data may not provide realistic estimates. The stochastic nature of the dependent and independent variables need to be taken into consideration in pollutant build-up prediction. It was found that the use of the Bayesian approach along with the Monte Carlo simulation technique provides a powerful tool, which attempts to make the best use of the available knowledge in prediction and thereby presents a practical solution to counteract the limitations which are otherwise imposed on water quality modelling. - Highlights: ► Water quality data spans short time scales leading to significant model uncertainty. ► Assessment of uncertainty essential for informed decision making in water

  11. Activities concerning a re-evaluation of gamma-ray buildup factors in Japan

    International Nuclear Information System (INIS)

    Hirayama, Hideo

    2000-01-01

    Research related to gamma-ray buildup factors in Japan are continuing to improve in accuracy and usefulness after the publication of new standard buildup factors as NUREG/CR-5740. Buildup factors for homogeneous materials were studied by three different calculation methods. Several improvements were made to calculate buildup factors up to 40 mfp for various materials for a wide energy range at each code. Systematic data production of buildup factors for multilayer materials were performed by using the EGS4 Monte Carlo code, and were used to improve the fitting formula. These research activities related to gamma-ray buildup factors performed in Japan are presented together with discussions concerning re-evaluation of buildup factors. (author)

  12. Cosmogonic scenario

    International Nuclear Information System (INIS)

    Alfven, H.; Arrhenius, G.

    1985-05-01

    A recent analysis demonstrates that the Saturnian C ring and essential features of the B and A rings agrees with the plasma cosmogony approach with an accuracy of about 1% or even better. This starts a transition of cosmogony from speculation to real science. Based on the monographs by Alfven and Arrhenius on the evolution of the solar system a cosmogonic scenario is tentatively proposed. This outlines the evolution of an interstellar cloud and the formation of stars surrounded by solar nebulae under the combined action of gravitational and electromagnetic forces. Further, matter falling in from the solar nebula towards the sun is processed by newly clarified electromagnetic processes and a plasma-planetesimal transition (PPT) occurs. Planetesimals accrete to planets and around some of them the same process in miniature leads to the formation of satellites. Also the origin of comets is discussed. (author)

  13. Buildup of 236U in the gaseous diffusion plant product

    International Nuclear Information System (INIS)

    Ford, J.S.

    1975-01-01

    A generalized projection of the average annual 236 U concentration that can be expected in future enriched uranium product from the US-ERDA gaseous diffusion plants when reprocessed fuels become available for cascade feeding is given. It is concluded that the buildup of 236 U is not an ever-increasing function, but approaches a limiting value. Projected concentrations result in only slight separative work losses and present no operational problem to ERDA in supplying light water reactor requirements. The use of recycle uranium from power reactor spent fuels will result in significant savings in natural uranium feed

  14. Energy buildup in sheared force-free magnetic fields

    Science.gov (United States)

    Wolfson, Richard; Low, Boon C.

    1992-01-01

    Photospheric displacement of the footpoints of solar magnetic field lines results in shearing and twisting of the field, and consequently in the buildup of electric currents and magnetic free energy in the corona. The sudden release of this free energy may be the origin of eruptive events like coronal mass ejections, prominence eruptions, and flares. An important question is whether such an energy release may be accompanied by the opening of magnetic field lines that were previously closed, for such open field lines can provide a route for matter frozen into the field to escape the sun altogether. This paper presents the results of numerical calculations showing that opening of the magnetic field is permitted energetically, in that it is possible to build up more free energy in a sheared, closed, force-free magnetic field than is in a related magnetic configuration having both closed and open field lines. Whether or not the closed force-free field attains enough energy to become partially open depends on the form of the shear profile; the results presented compare the energy buildup for different shear profiles. Implications for solar activity are discussed briefly.

  15. New buildup factor data for point kernel calculations

    International Nuclear Information System (INIS)

    Trubey, D.K.; Harima, Y.

    1986-01-01

    An American Nuclear Society Standards Committee Working Group, identified as ANS-6.4.3, is developing a set of evaluated gamma-ray isotropic point-source buildup factors and attenuation coefficients for a standard reference data base. As a first step, a largely unpublished set of buildup factors calculated with the moments method has been evaluated by recalculating key values with Monte Carlo, integral transport, and discrete ordinates methods. Attention is being given to frequently-neglected processes such as bremsstrahlung and the effect of introducing a tissue phantom behind the shield. The proposed standard contains data for a source energy range from 15 keV to 15 MeV and for approximately 19 elements and 3 mixtures (water, air, and concrete). The data will also be represented as coefficients for the G-P fitting function. The 1985 data base was released as part of the CCC-493B/QAD-CGGP code package available from the Radiation Shielding Information Center (RSIC)

  16. Scintiscanning of arthritis and analysis of build-up curves

    International Nuclear Information System (INIS)

    Yamagishi, Tsuneo; Omori, Shigeo; Miyawaki, Haruo; Maniwa, Masato; Yoshizaki, Kenichi

    1975-01-01

    In the present study 40 knee joints with rheumatoid arthritis, 23 knee joints with osteoarthrosis deformans, 3 knee joints with non-synovitis, one knee joint with pyogenic arthritis and 4 normal knee joints were scanned. By analysis of build-up curves obtained immediately after the intravenous injection of sup(99m)Tc-pertechnetate, the rate of accumulation of radioactivity (t 1/2) in the affected joints was simultaneously estimated in order to compare them with clinical findings. 1. Scintiscanning of arthritis, rheumatoid arthritis, osteoarthrosis deformans of the knee joint, non-specific synovitis, and pyogenic arthritis of the knee joint, yielded a positive scan for all of the joint diseases. 2. In the scintigram of healthy knee joints, there are no areas of RI accumulation or right to left difference. 3. In some instances abnormal uptake of RI was seen on scintigrams of arthritis even after normal clinical and laboratory findings had been achieved with therapy. 4. sup(99m)Tc-pertechnetate, a radionuclide with a short half-life, allows repeated scans and provides a useful radiologic means of evaluating therapeutic course and effectiveness. 5. Analysis of build-up curves revealed that the rate of accumulation of RI was faster in rheumatoid arthritis than in osteoarthrosis deformans. (auth.)

  17. A modified method of calculating the lateral build-up ratio for small electron fields

    International Nuclear Information System (INIS)

    Tyner, E; McCavana, P; McClean, B

    2006-01-01

    This note outlines an improved method of calculating dose per monitor unit values for small electron fields using Khan's lateral build-up ratio (LBR). This modified method obtains the LBR directly from the ratio of measured, surface normalized, electron beam percentage depth dose curves. The LBR calculated using this modified method more accurately accounts for the change in lateral scatter with decreasing field size. The LBR is used along with Khan's dose per monitor unit formula to calculate dose per monitor unit values for a set of small fields. These calculated dose per monitor unit values are compared to measured values to within 3.5% for all circular fields and electron energies examined. The modified method was further tested using a small triangular field. A maximum difference of 4.8% was found. (note)

  18. Buildup factor studies of HCO-materials as a function of weight fraction of constituent elements

    International Nuclear Information System (INIS)

    Brar, G.S.; Sidhu, G.S.; Singh, Parjit S.; Mudahar, Gurmel S.

    1999-01-01

    The effects of fractional abundance of constituent elements have been investigated on the energy absorption buildup factors of HCO-materials for some incident photon energies at a fixed penetration depth of 20 mfp. At low incident photon energies, a change in buildup factor is seen whereas buildup factor values of HCO-materials are independent of fractional abundances of H, C and O for high energies

  19. New concept of the buildup factor in bent ducts

    International Nuclear Information System (INIS)

    Faik Ouahab, Z.; Jehouani, A.; Groetz, J.-E.

    2011-01-01

    A major problem confronting the radiation shielding designer is the accurate determination of neutron streaming through various penetrations in walls, ducts and mazes. The previous studies on neutron transmission were performed through empty ducts. The aim of this work is to evaluate the neutron transmission probability through a filled bent duct and the proposition of a new concept of the buildup factor for neutrons in multilegged ducts. An angular biaising technique is used in the Monte Carlo simulations to accelerate the calculation convergence. Results are first compared with those obtained by the MCNPX code. For an empty bent duct, the neutron transmission is only due to the neutron reflection on the duct wall. For a filled duct, the major contribution is due to the scattering on the atoms filling the duct.

  20. Detection of hydrogen buildup in initially pure nonhydrogenous liquids

    International Nuclear Information System (INIS)

    McNeany, S.R.; Jenkins, J.D.

    1978-12-01

    A technique for monitoring hydrogen buildup in initially pure nonhydrogenous liquids is described in this report. The detection method is based upon the neutron-moderating properties of hydrogen. The analysis leading to the selection and design of a hydrogen-monitoring device is described. An experimental mockup of the device was then constructed and tested for hydrogen sensitivity. A hot cell was used for these tests. A device proved capable of measuring hydrogen concentrations in the range of 0 to 13.0 x 10 27 atoms/m 3 , with an accuracy of about 1.0 x 10 27 atoms/m 3 . A typical measurement can be made in 3 to 5 min. The experimental results confirmed the sensitivities predicted by the analysis and demonstrated that such a device would be practical for hydrogen concentration measurements for criticality control in an HTGR fuel refabrication plant

  1. Electron-Cloud Build-Up: Theory and Data

    International Nuclear Information System (INIS)

    Furman, M.A.

    2010-01-01

    We present a broad-brush survey of the phenomenology, history and importance of the electron-cloud effect (ECE). We briefly discuss the simulation techniques used to quantify the electron-cloud (EC) dynamics. Finally, we present in more detail an effective theory to describe the EC density build-up in terms of a few effective parameters. For further details, the reader is encouraged to refer to the proceedings of many prior workshops, either dedicated to EC or with significant EC contents, including the entire 'ECLOUD' series. In addition, the proceedings of the various flavors of Particle Accelerator Conferences contain a large number of EC-related publications. The ICFA Beam Dynamics Newsletter series contains one dedicated issue, and several occasional articles, on EC. An extensive reference database is the LHC website on EC.

  2. Buildup of radioxenon isotopes in MOX-assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Gniffke, Thomas; Kirchner, Gerald [Carl Friedrich von Weizsaecker-Centre for Science and Peace Research, Hamburg (Germany)

    2015-07-01

    Radioxenon is the main tracer for detection of nuclear tests conducted underground under the verification regime of the Comprehensive Nuclear Test Ban Treaty (CTBT). Since radioxenon is emitted by civilian sources too, like commercial nuclear reactors, source discrimination is still an important issue. Inventory calculations are necessary to predict which xenon isotopic ratios are built up in a reactor and how they differ from those generated by a nuclear explosion. The screening line actually used by the CTBT Organization for source discrimination is based on calculations for uranium fuel of various enrichments used in pressurized water reactors (PWRs). The usage of different fuel, especially mixed U/Pu oxide (MOX) assemblies with reprocessed plutonium, may alter the radioxenon signature of civilian reactors. In this talk, calculations of the radioxenon buildup in a MOX-assembly used in a commercial PWR are presented. Implications for the CTBT verification regimes are discussed and open questions are addressed.

  3. Investigating the build-up of precedence effect using reflection masking

    DEFF Research Database (Denmark)

    Hartcher-O'Brien, Jessica; Buchholz, Jörg

    2006-01-01

    signal processing, such an approach represents a bottom-up approach to the buildup of precedence. Three conditioner configurations measuring a possible buildup of reflection suppression were compared to the baseline RMT for four reflection delays ranging from 2.5–15 ms. No buildup of reflection...... suppression was observed for any of the conditioner configurations. Buildup of template (decrease in RMT for two of the conditioners), on the other hand, was found to be delay dependent. For five of six listeners, with reflection delay=2.5 and 15 ms, RMT decreased relative to the baseline. For 5- and 10-ms...

  4. Damage buildup and edge dislocation mobility in equiatomic multicomponent alloys

    Science.gov (United States)

    Granberg, F.; Djurabekova, F.; Levo, E.; Nordlund, K.

    2017-02-01

    A new class of single phase metal alloys of equal atomic concentrations has shown very promising mechanical properties and good corrosion resistance. Moreover, a significant reduction in damage accumulation during prolonged irradiation has also been observed in these equiatomic multicomponent alloys. A comparison of elemental Ni with the two component NiFe- and the three component NiCoCr-alloy showed a substantial reduction in damage in both alloys, and an even larger difference was seen if only larger clusters were considered. One of the factors limiting the damage build-up in the alloys compared to the elemental material was seen to be dislocation mobility (Granberg et al., 2016). In this Article, we focus on a more thorough investigation of the mobility of edge dislocations in different cases of the Ni-, NiFe- and NiCoCr-samples. We find that even though the saturated amount of defects in the alloys is lower than in elemental Ni, the defect buildup in the early stages is faster in the alloys. We also find that the dislocation mobility in NiFe is lower than in Ni, at low stresses, and that the onset stress in NiFe is higher than in Ni. The same phenomenon was seen in comparison between NiFe and NiCoCr, since the three component alloy had lower dislocation mobility and higher onset stress. The dislocation velocity in elemental Ni plateaued out just under the forbidden velocity, whereas the alloys showed a more complex behaviour.

  5. SU-E-T-104: An Examination of Dose in the Buildup and Build-Down Regions

    International Nuclear Information System (INIS)

    Tome, W; Kuo, H; Phillips, J

    2015-01-01

    Purpose: To examine dose in the buildup and build-down regions and compare measurements made with various models and dosimeters Methods: Dose was examined in a 30×30cm 2 phantom of water-equivalent plastic with 10cm of backscatter for various field sizes. Examination was performed with radiochromic film and optically-stimulated-luminescent-dosimeter (OSLD) chips, and compared against a plane-parallel chamber with a correction factor applied to approximate the response of an extrapolation chamber. For the build-down region, a correction factor to account for table absorption and chamber orientation in the posterior-anterior direction was applied. The measurement depths used for the film were halfway through their sensitive volumes, and a polynomial best fit curve was used to determine the dose to their surfaces. This chamber was also compared with the dose expected in a clinical kernel-based computer model, and a clinical Boltzmann-transport-equation-based (BTE) computer model. The two models were also compared against each other for cases with air gaps in the buildup region. Results: Within 3mm, all dosimeters and models agreed with the chamber within 10% for all field sizes. At the entrance surface, film differed in comparison with the chamber from +90% to +15%, the BTE-model by +140 to +3%, and the kernel-based model by +20% to −25%, decreasing with increasing field size. At the exit surface, film differed in comparison with the chamber from −10% to −15%, the BTE-model by −53% to −50%, the kernel-based model by −55% to −57%, mostly independent of field size. Conclusion: The largest differences compared with the chamber were found at the surface for all field sizes. Differences decreased with increasing field size and increasing depth in phantom. Air gaps in the buildup region cause dose buildup to occur again post-gap, but the effect decreases with increasing phantom thickness prior to the gap

  6. Recommendations on dose buildup factors used in models for calculating gamma doses for a plume

    International Nuclear Information System (INIS)

    Hedemann Jensen, P.; Thykier-Nielsen, S.

    1980-09-01

    Calculations of external γ-doses from radioactivity released to the atmosphere have been made using different dose buildup factor formulas. Some of the dose buildup factor formulas are used by the Nordic countries in their respective γ-dose models. A comparison of calculated γ-doses using these dose buildup factors shows that the γ-doses can be significantly dependent on the buildup factor formula used in the calculation. Increasing differences occur for increasing plume height, crosswind distance, and atmospheric stability and also for decreasing downwind distance. It is concluded that the most accurate γ-dose can be calculated by use of Capo's polynomial buildup factor formula. Capo-coefficients have been calculated and shown in this report for γ-energies below the original lower limit given by Capo. (author)

  7. VVER operational experience - effect of preconditioning and primary water chemistry on radioactivity build-up

    International Nuclear Information System (INIS)

    Zmitko, M.; Kysela, J.; Dudjakova, K.; Martykan, M.; Janesik, J.; Hanus, V.; Marcinsky, P.

    2004-01-01

    The primary coolant technology approaches currently used in VVER units are reviewed and compared with those used in PWR units. Standard and modified water chemistries differing in boron-potassium control are discussed. Preparation of the VVER Primary Water Chemistry Guidelines in the Czech Republic is noted. Operational experience of some VVER units, operated in the Czech Republic and Slovakia, in the field of the primary water chemistry, and radioactivity transport and build-up are presented. In Mochovce and Temelin units, a surface preconditioning (passivation) procedure has been applied during hot functional tests. The main principles of the controlled primary water chemistry applied during the hot functional tests are reviewed and importance of the water chemistry, technological and other relevant parameters is stressed regarding to the quality of the passive layer formed on the primary system surfaces. The first operational experience obtained in the course of beginning of these units operation is presented mainly with respect to the corrosion products coolant and surface activities. Effect of the initial passivation performed during hot functional tests and the primary water chemistry on corrosion products radioactivity level and radiation situation is discussed. (author)

  8. The Mechanism for Energy Buildup in the Solar Corona

    Science.gov (United States)

    Antiochos, Spiro; Knizhnik, Kalman; DeVore, Richard

    2017-10-01

    Magnetic reconnection and helicity conservation are two of the most important basic processes determining the structure and dynamics of laboratory and space plasmas. The most energetic dynamics in the solar system are the giant CMEs/flares that produce the most dangerous space weather at Earth, yet may also have been essential for the origin of life. The origin of these explosions is that the lowest-lying magnetic flux in the Sun's corona undergoes the continual buildup of stress and free energy that can be released only through explosive ejection. We perform MHD simulations of a coronal volume driven by quasi-random boundary flows designed to model the processes by which the solar interior drives the corona. Our simulations are uniquely accurate in preserving magnetic helicity. We show that even though small-scale stress is injected randomly throughout the corona, the net result of magnetic reconnection is a coherent stressing of the lowest-lying field lines. This highly counter-intuitive result - magnetic stress builds up locally rather than spreading out to a minimum energy state - is the fundamental mechanism responsible for the Sun's magnetic explosions. It is likely to be a mechanism that is ubiquitous throughout laboratory and space plasmas. This work was supported by the NASA LWS and SR Programs.

  9. Interpretation of the mitigation of runoff on the FOCUS Surface Water Scenarios as described in the FOCUS l&M report

    NARCIS (Netherlands)

    Horst, ter M.M.S.; Adriaanse, P.I.; Boesten, J.J.T.I.

    2009-01-01

    Our interpretation is that the reduced runoff fluxes (water and mass) of the 20 ha upstream are combined with the unchanged runoff water fluxes of the remaining 80 ha upstream catchment. This implies that the reduction factor on exposure concentrations in FOCUS streams of Step 4 FOCUS scenarios

  10. The effect of zinc injection into PWR primary coolant on the reduction of radiation buildup and corrosion control. The solubilities of zinc, nickel and cobalt spinel oxides

    International Nuclear Information System (INIS)

    Miyajima, Kaori; Hirano, Hideo

    1999-01-01

    The use of zinc injection into PWR primary coolant to reduce radiation buildup has been widely studied, and te reduction effect has been experimentally confirmed. However, some items, such as the optimal concentration of zinc required to reduce radiation buildup, the corrosion control effect of zinc injection, and the influence of zinc injection on the integrity of fuel cladding, have not been clarified yet. In particular, the corrosion suppression effect of zinc remains unconfirmed. Therefore, it is necessary to measure and calculate the solubilities of zinc and nickel spinel oxides, which are formed on the surface of Ni-based alloys in PWR primary systems. In this study, in order to assess the effectiveness of zinc injection in the reduction of radiation buildup and the corrosion control of Ni-based alloy, the potential-pH diagrams for Zn-Cr-H 2 O, Ni-Cr-H 2 O, and Co-Cr-H 2 O systems at 300degC were constructed and the solubilities of Zn-Cr, Ni-Cr, and Co-Cr spinel oxides were calculated. It is concluded that under pH conditions for which NiCr 2 O 4 is stable, zinc injection is effective in corrosion control as well as in reducing radiation buildup. (author)

  11. Erosion scenarios for Wellenberg

    International Nuclear Information System (INIS)

    Klemenz, W.

    1993-09-01

    The proposed Wellenberg site for a radioactive waste repository is located between Altzellen in the Engelberger valley and the Oberrickenbach valley, in a thick Valanginian marl series. The marl is generally overlaid with unconsolidated rocks but reaches to the surface in some places. In contrast to the situation in the Oberbauenstock region this marl complex is not protected by an overlying erosion resistant series and exhibits a marked relief. The question therefore arises with respect to the Wellenberg site, to what extent will the marl (i.e. the repository host rock formation) be removed by erosion processes during the 100,000 years interval under consideration and what overburden will remain at the end of this period. This report presents the results of an investigation of the longterm behaviour of the proposed site in respect of those processes of erosion and deposition which can lead to changes in the terrain surface and its location relative to the repository. A wide range of possible scenarios encompassing different developments of climatic conditions during the 100,000 year period of interest, was investigated. In addition to the continuation of the present climate and the occurrence of a new ice age on the scale of the Wuerm glaciation the consequences of altered climatic conditions on erosion removal of the repository overburden were considered. Within the 100,000 year period of interest none of the scenarios considered leads to the exposure of the repository. (author) figs., tabs, refs

  12. Total Ambient Dose Equivalent Buildup Factor Determination for Nbs04 Concrete.

    Science.gov (United States)

    Duckic, Paulina; Hayes, Robert B

    2018-06-01

    Buildup factors are dimensionless multiplicative factors required by the point kernel method to account for scattered radiation through a shielding material. The accuracy of the point kernel method is strongly affected by the correspondence of analyzed parameters to experimental configurations, which is attempted to be simplified here. The point kernel method has not been found to have widespread practical use for neutron shielding calculations due to the complex neutron transport behavior through shielding materials (i.e. the variety of interaction mechanisms that neutrons may undergo while traversing the shield) as well as non-linear neutron total cross section energy dependence. In this work, total ambient dose buildup factors for NBS04 concrete are calculated in terms of neutron and secondary gamma ray transmission factors. The neutron and secondary gamma ray transmission factors are calculated using MCNP6™ code with updated cross sections. Both transmission factors and buildup factors are given in a tabulated form. Practical use of neutron transmission and buildup factors warrants rigorously calculated results with all associated uncertainties. In this work, sensitivity analysis of neutron transmission factors and total buildup factors with varying water content has been conducted. The analysis showed significant impact of varying water content in concrete on both neutron transmission factors and total buildup factors. Finally, support vector regression, a machine learning technique, has been engaged to make a model based on the calculated data for calculation of the buildup factors. The developed model can predict most of the data with 20% relative error.

  13. A new approximating formula for calculating gamma-ray buildup factors in multilayer shields

    International Nuclear Information System (INIS)

    Assad, A.; Chiron, M.; Nimal, J.C.; Diop, C.M.; Ridoux, P.

    1999-01-01

    This study proposes a new approximating formula for calculating gamma-ray buildup factors in multilayer shields. The formula combines the buildup factors of single-layer shields with products and quotients. The feasibility of the formula for reproducing the buildup factors was tested by using point isotropic buildup factors calculated with the SN1D discrete ordinates code as reference data. The dose buildup factors of single-, double-, and multilayer shields composed of water, aluminum, iron, and lead were calculated for a spherical geometry in the energy range between 10 MeV and 40 keV and for total thicknesses of up to 30 mean free paths. The calculation of the buildup factors takes into account the bound electron effect of Compton scattering (incoherent scattering), the coherent scattering, the pair production, and the secondary sources of bremsstrahlung and fluorescence. The tests have shown that the approximating formula reproduces the reference data of double-layer shields very well for most cases. With the same parameters and with a new physical consideration that takes into account in a global way the degradation of the gamma-ray energy spectrum, the buildup factors of three- and five-layer shields were also very well reproduced

  14. MAGNETIC ENERGY BUILDUP FOR RELATIVISTIC MAGNETAR GIANT FLARES

    International Nuclear Information System (INIS)

    Yu Cong

    2011-01-01

    Motivated by coronal mass ejection studies, we construct general relativistic models of a magnetar magnetosphere endowed with strong magnetic fields. The equilibrium states of the stationary, axisymmetric magnetic fields in the magnetar magnetosphere are obtained as solutions of the Grad-Shafranov equation in a Schwarzschild spacetime. To understand the magnetic energy buildup in the magnetar magnetosphere, a generalized magnetic virial theorem in the Schwarzschild metric is newly derived. We carefully address the question whether the magnetar magnetospheric magnetic field can build up sufficient magnetic energy to account for the work required to open up the magnetic field during magnetar giant flares. We point out the importance of the Aly-Sturrock constraint, which has been widely studied in solar corona mass ejections, as a reference state in understanding magnetar energy storage processes. We examine how the magnetic field can possess enough energy to overcome the Aly-Sturrock energy constraint and open up. In particular, general relativistic (GR) effects on the Aly-Sturrock energy constraint in the Schwarzschild spacetime are carefully investigated. It is found that, for magnetar outbursts, the Aly-Sturrock constraint is more stringent, i.e., the Aly-Sturrock energy threshold is enhanced due to the GR effects. In addition, neutron stars with greater mass have a higher Aly-Sturrock energy threshold and are more difficult to erupt. This indicates that magnetars are probably not neutron stars with extreme mass. For a typical neutron star with mass of 1-2 M sun , we further explore the cross-field current effects, caused by the mass loading, on the possibility of stored magnetic field energy exceeding the Aly-Sturrock threshold.

  15. Effect of ultraviolet light irradiation period on bond strengths between fiber-reinforced composite post and core build-up composite resin.

    Science.gov (United States)

    Asakawa, Yuya; Takahashi, Hidekazu; Iwasaki, Naohiko; Kobayashi, Masahiro

    2014-01-01

    The aim of the present study was to characterize the effects of the ultraviolet light (UV) irradiation period on the bond strength of fiber-reinforced composite (FRC) posts to core build-up resin. Three types of FRC posts were prepared using polymethyl methacrylate, urethane dimethacrylate, and epoxy resin. The surfaces of these posts were treated using UV irradiation at a distance of 15 mm for 0 to 600 s. The pull-out bond strength was measured and analyzed with the Dunnett's comparison test (α=0.05). The bond strengths of the post surfaces without irradiation were 6.9 to 7.4 MPa; those after irradiation were 4.2 to 26.1 MPa. The bond strengths significantly increased after 15 to 120-s irradiation. UV irradiation on the FRC posts improved the bond strengths between the FRC posts and core build-up resin regardless of the type of matrix resin.

  16. Activity build-up on the circulation loops of boiling water reactors: Basics for modelling of transport and deposition processes

    International Nuclear Information System (INIS)

    Covelli, B.; Alder, H.P.

    1988-03-01

    In the past 20 years the radiation field of nuclear power plant loops outside the core zone was the object of investigations in many countries. In this context test loops were built and basic research done. At our Institute PSI the installation of a LWR-contamination loop is planned for this year. This experimental loop has the purpose to investigate the complex phenomena of activity deposition from the primary fluid of reactor plants and to formulate analytical models. From the literature the following conclusions can be drawn: The principal correlations of the activity build-up outside the core are known. The plant specific single phenomena as corrosion, crud-transport, activation and deposit of cobalt in the oxide layer are complex and only partially understood. The operational experience of particular plants with low contaminated loops (BWR-recirculation loops) show that in principle the problem is manageable. The reduction of the activity build-up in older plants necessitates a combination of measures to modify the crud balance in the primary circuit. In parallel to the experimental work several simulation models in the form of computer programs were developed. These models have the common feature that they are based on mass balances, in which the exchange of materials and the sedimentation processes are described by global empirical transport coefficients. These models yield satisfactory results and allow parameter studies; the application however is restricted to the particular installation. All programs lack models that describe the thermodynamic and hydrodynamic mechanisms on the surface of deposition layers. Analytical investigations on fouling of process equipment led to models that are also applicable to the activity build-up in reactor loops. Therefore it seems appropriate to combine the nuclear simulation models with the fundamental equations for deposition. 10 refs., 18 figs., 3 tabs

  17. Electron-cloud build-up in hadron machines

    International Nuclear Information System (INIS)

    Furman, M.A.

    2004-01-01

    ,17]. In this article we focus on the mechanisms of electron-cloud buildup and dissipation for hadronic beams, particularly those with very long, intense, bunches

  18. Opacity Build-up in Impulsive Relativistic Sources

    International Nuclear Information System (INIS)

    Granot, Jonathan; Cohen-Tanugi, Johann; Silva, Eduardo do Couto e

    2007-01-01

    Opacity effects in relativistic sources of high-energy gamma-rays, such as gamma-ray bursts (GRBs) or Blazars, can probe the Lorentz factor of the outflow as well as the distance of the emission site from the source, and thus help constrain the composition of the outflow (protons, pairs, magnetic field) and the emission mechanism. Most previous works consider the opacity in steady state. Here we study the effects of the time dependence of the opacity to pair production (γγ → e + e - ) in an impulsive relativistic source, which may be relevant for the prompt gamma-ray emission in GRBs or flares in Blazars. We present a simple, yet rich, semi-analytic model for the time and energy dependence of the optical depth, τγγ, in which a thin spherical shell expands ultra-relativistically and emits isotropically in its own rest frame over a finite range of radii, R 0 (le) R (le) R 0 +ΔR. This is particularly relevant for GRB internal shocks. We find that in an impulsive source (ΔR ∼ 0 ), while the instantaneous spectrum (which is typically hard to measure due to poor photon statistics) has an exponential cutoff above the photon energy (var e psilon)1(T) where tγγ((var e psilon)1) = 1, the time integrated spectrum (which is easier to measure) has a power-law high-energy tail above the photon energy (var e psilon)1* ∼ (var e psilon)1(ΔT) where ΔT is the duration of the emission episode. Furthermore, photons with energies (var e psilon) > (var e psilon)1* are expected to arrive mainly near the onset of the spike in the light curve or flare, which corresponds to the short emission episode. This arises since in such impulsive sources it takes time to build-up the (target) photon field, and thus the optical depth τγγ((var e psilon)) initially increases with time and (var e psilon)1(T) correspondingly decreases with time, so that photons of energy (var e psilon) > (var e psilon)1* are able to escape the source mainly very early on while (var e psilon)1(T) > (var

  19. History matching of transient pressure build-up in a simulation model using adjoint method

    Energy Technology Data Exchange (ETDEWEB)

    Ajala, I.; Haekal, Rachmat; Ganzer, L. [Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany); Almuallim, H. [Firmsoft Technologies, Inc., Calgary, AB (Canada); Schulze-Riegert, R. [SPT Group GmbH, Hamburg (Germany)

    2013-08-01

    The aim of this work is the efficient and computer-assisted history-matching of pressure build-up and pressure derivatives by small modification to reservoir rock properties on a grid by grid level. (orig.)

  20. The build-up and characterization of nuclear burn-up wave in a fast ...

    Indian Academy of Sciences (India)

    K V Anoop

    2018-02-07

    Feb 7, 2018 ... evaluating the quality of the wave by the researchers working in the field of nuclear burn-up wave build-up and propagation. Keywords. ... However, there are concerns relating to the nuclear safety, ... Simulation studies have.

  1. Development and buildup of a biomass by various yeasts on whey

    Energy Technology Data Exchange (ETDEWEB)

    Zalashka, L S; Samtsevich, S A; Bakunowicz, L

    1967-01-01

    Of the 113 strains of yeast grown on whey, 29 assimilated lactose by fermentation and 23 by direct souring. The most productive were Candida humicola and C. curvata. The buildup of biomass averaged 18 to 30 g./1. medium.

  2. The effect of electron collimator leaf shape on the build-up dose in narrow electron MLC fields

    International Nuclear Information System (INIS)

    Vatanen, T; Vaeaenaenen, A; Lahtinen, T; Traneus, E

    2009-01-01

    Previously, we have found that the build-up dose from abutting narrow electron beams formed with unfocussed electron multi-leaf collimator (eMLC) steal leaves was higher than with the respective open field. To investigate more closely the effect of leaf material and shape on dose in the build-up region, straight, round (radius 1.5 cm) and leaf ends with a different front face angle of α (leaf front face pointing towards the beam axis at an angle of 90 - α) made of steel, brass and tungsten were modelled using the BEAMnrc code. Based on a treatment head simulation of a Varian 2100 C/D linac, depth-dose curves and profiles in water were calculated for narrow 6, 12 and 20 MeV eMLC beams (width 1.0 cm, length 10 cm) at source-to-surface distances (SSD) of 102 and 105 cm. The effects of leaf material and front face angle were evaluated based on electron fluence, angle and energy spectra. With a leaf front face angle of 15 deg., the dose in the build-up region of the 6 MeV field varied between 91 and 100%, while for straight and round leaf shapes the dose varied between 89 and 100%. The variation was between 94 and 100% for 12 and 20 MeV. For abutting narrow 6 MeV fields with total field size 5 x 10 cm 2 , the build-up doses at 5 mm depth for the face angle 15 deg. and straight and round leaf shapes were 96% and 86% (SSD 102 cm) and 89% and 85% (SSD 105 cm). With higher energies, the effect of eMLC leaf shape on dose at 5 mm was slight (3-4% units with 12 MeV) and marginal with 20 MeV. The fluence, energy and angle spectra for total and leaf scattered electrons were practically the same for different leaf materials with 6 MeV. With high energies, the spectra for tungsten were more peaked due to lower leaf transmission. Compared with straight leaf ends, the face angle of 15 deg. and round leaf ends led to a 1 mm (for 6 MeV) and between 1 and 5 mm (12 and 20 MeV at a SSD of 105 cm) decrease of therapeutic range and increase of the field size, respectively. However

  3. Probabilistic Near and Far-Future Climate Scenarios of Precipitation and Surface Temperature for the North American Monsoon Region Under a Weighted CMIP5-GCM Ensemble Approach.

    Science.gov (United States)

    Montero-Martinez, M. J.; Colorado, G.; Diaz-Gutierrez, D. E.; Salinas-Prieto, J. A.

    2017-12-01

    It is well known the North American Monsoon (NAM) region is already a very dry region which is under a lot of stress due to the lack of water resources on multiple locations of the area. However, it is very interesting that even under those conditions, the Mexican part of the NAM region is certainly the most productive in Mexico from the agricultural point of view. Thus, it is very important to have realistic climate scenarios for climate variables such as temperature, precipitation, relative humidity, radiation, etc. This study tries to tackle that problem by generating probabilistic climate scenarios using a weighted CMIP5-GCM ensemble approach based on the Xu et al. (2010) technique which is on itself an improved method from the better known Reliability Ensemble Averaging algorithm of Giorgi and Mearns (2002). In addition, it is compared the 20-plus GCMs individual performances and the weighted ensemble versus observed data (CRU TS2.1) by using different metrics and Taylor diagrams. This study focuses on probabilistic results reaching a certain threshold given the fact that those types of products could be of potential use for agricultural applications.

  4. Prediction of wax buildup in 24 inch cold, deep sea oil loading line

    Energy Technology Data Exchange (ETDEWEB)

    Asperger, R.G.; Sattler, R.E.; Tolonen, W.J.; Pitchford, A.C.

    1981-10-01

    When designing pipelines for cold environments, it is important to know how to predict potential problems due to wax deposition on the pipeline's inner surface. The goal of this work was to determine the rate of wax buildup and the maximum, equlibrium wax thickness for a North Sea field loading line. The experimental techniques and results used to evaluate the waxing potential of the crude oil (B) are described. Also, the theoretic model which was used for predicting the maximum wax deposit thickness in the crude oil (B) loading pipeline at controlled temperatures of 40 F (4.4 C) and 100 F (38 C), is illustrated. Included is a recommendation of a procedure for using hot oil at the end of a tanker loading period in order to dewax the crude oil (B) line. This technique would give maximum heating of the pipeline and should be followed by shutting the hot oil into the pipeline at the end of the loading cycle which will provide a hot oil soaking to help soften existing wax. 14 references.

  5. Shielded button electrodes for time-resolved measurements of electron cloud buildup

    International Nuclear Information System (INIS)

    Crittenden, J.A.; Billing, M.G.; Li, Y.; Palmer, M.A.; Sikora, J.P.

    2014-01-01

    We report on the design, deployment and signal analysis for shielded button electrodes sensitive to electron cloud buildup at the Cornell Electron Storage Ring. These simple detectors, derived from a beam-position monitor electrode design, have provided detailed information on the physical processes underlying the local production and the lifetime of electron densities in the storage ring. Digitizing oscilloscopes are used to record electron fluxes incident on the vacuum chamber wall in 1024 time steps of 100 ps or more. The fine time steps provide a detailed characterization of the cloud, allowing the independent estimation of processes contributing on differing time scales and providing sensitivity to the characteristic kinetic energies of the electrons making up the cloud. By varying the spacing and population of electron and positron beam bunches, we map the time development of the various cloud production and re-absorption processes. The excellent reproducibility of the measurements also permits the measurement of long-term conditioning of vacuum chamber surfaces

  6. Clinical comparison of various esthetic restorative options for coronal build-up of primary anterior teeth

    Directory of Open Access Journals (Sweden)

    Himanshu Duhan

    2015-01-01

    Full Text Available Background: This study was designed to compare the clinical performance of composite, strip crowns, biological restoration, and composite with stainless steel band when used for the coronal build-up of anterior teeth. Materials and Methods: A total of 20 patients aged 3-6 years presenting with mutilated primary anterior teeth due to caries or trauma were selected for the study using randomized simple sampling. A total of 52 primary anterior teeth were randomly divided into four equal groups having 13 teeth in each group. Teeth in Group I were restored with composite, in Group II with strip crowns, in Group III with biologic restoration and with stainless steel band reinforced composite in group IV. The restorations were evaluated for color match, retention, surface texture, and anatomic form according to Ryge′s Direct (US Public Health Service evaluation criteria at baseline (immediate postoperative, after 48 h, 3, 6, and 9 months. The data obtained were statistically analyzed using Chi-square test, and level of significance, that is, P value was determined. Results: At baseline, none of the groups showed any color changes. Other than Group III all other groups showed highly significant changes (P 0.05. Deterioration in surface texture was exhibited maximum by restorations in Group IV followed by Group I at 3 months. Whereas, no surface changes were seen in Group II and III. Only Group I and IV showed discontinuity in anatomic form after 3 months. After 6 months, except in Group II, discontinuity in anatomic form was observed in all the groups. Discontinuity in anatomic form was seen in all the 4 groups after 9 months although the difference was not significant (P > 0.05. Conclusion: Biological restoration was found to be most satisfying esthetically owing to color compatibility with the patient′s tooth. Thus, it has a great potential to be used as esthetic restorative option in primary anteriors.

  7. TURVA-2012: Formulation of radionuclide release scenarios

    International Nuclear Information System (INIS)

    Marcos, Nuria; Hjerpe, Thomas; Snellman, Margit; Ikonen, Ari; Smith, Paul

    2014-01-01

    TURVA-2012 is Posiva's safety case in support of the Preliminary Safety Analysis Report (PSAR) and application for a construction licence for a repository for disposal of spent nuclear fuel at the Olkiluoto site in south-western Finland. This paper gives a summary of the scenarios and the methodology followed in formulating them as described in TURVA-2012: Formulation of Radionuclide Release Scenarios (Posiva, 2013). The scenarios are further analysed in TURVA-2012: Assessment of Radionuclide Release Scenarios for the Repository System and TURVA-2012: Biosphere Assessment (Posiva, 2012a, 2012b). The formulation of scenarios takes into account the safety functions of the main barriers of the repository system and the uncertainties in the features, events, and processes (FEP) that may affect the entire disposal system (i.e. repository system plus the surface environment) from the emplacement of the first canister until the far future. In the report TURVA-2012: Performance Assessment (2012d), the performance of the engineered and natural barriers has been assessed against the loads expected during the evolution of the repository system and the site. Uncertainties have been identified and these are taken into account in the formulation of radionuclide release scenarios. The uncertainties in the FEP and evolution of the surface environment are taken into account in formulating the surface environment scenarios used ultimately in estimating radiation exposure. Formulating radionuclide release scenarios for the repository system links the reports Performance Assessment and Assessment of Radionuclide Release Scenarios for the Repository System. The formulation of radionuclide release scenarios for the surface environment brings together biosphere description and the surface environment FEP and is the link to the assessment of the surface environment scenarios summarised in TURVA-2012: Biosphere Assessment. (authors)

  8. Modeling nitrate from land surface to wells' perforations under agricultural land: success, failure, and future scenarios in a Mediterranean case study

    Directory of Open Access Journals (Sweden)

    Y. Levy

    2017-07-01

    that the high concentrations in some wells cannot be explained by regular agricultural activity and are probably due to malfunctions in the well area. Prediction of the nitrate concentration 40 years in the future with three nitrogen-fertilization scenarios showed that (i under the business as usual fertilization scenario, the nitrate concentration (as NO3− will increase on average by 19 mg L−1; (ii under a scenario of 25 % reduction of nitrogen fertilization, the nitrate concentration in the aquifer will stabilize; (iii with a 50 % reduction of nitrogen fertilization, the nitrate concentration will decrease on average by 18 mg L−1.

  9. Modeling nitrate from land surface to wells' perforations under agricultural land: success, failure, and future scenarios in a Mediterranean case study

    Science.gov (United States)

    Levy, Yehuda; Shapira, Roi H.; Chefetz, Benny; Kurtzman, Daniel

    2017-07-01

    be explained by regular agricultural activity and are probably due to malfunctions in the well area. Prediction of the nitrate concentration 40 years in the future with three nitrogen-fertilization scenarios showed that (i) under the business as usual fertilization scenario, the nitrate concentration (as NO3-) will increase on average by 19 mg L-1; (ii) under a scenario of 25 % reduction of nitrogen fertilization, the nitrate concentration in the aquifer will stabilize; (iii) with a 50 % reduction of nitrogen fertilization, the nitrate concentration will decrease on average by 18 mg L-1.

  10. A KNOWLEDGE DISCOVERY STRATEGY FOR RELATING SEA SURFACE TEMPERATURES TO FREQUENCIES OF TROPICAL STORMS AND GENERATING PREDICTIONS OF HURRICANES UNDER 21ST-CENTURY GLOBAL WARMING SCENARIOS

    Data.gov (United States)

    National Aeronautics and Space Administration — A KNOWLEDGE DISCOVERY STRATEGY FOR RELATING SEA SURFACE TEMPERATURES TO FREQUENCIES OF TROPICAL STORMS AND GENERATING PREDICTIONS OF HURRICANES UNDER 21ST-CENTURY...

  11. Exposure scenarios for workers

    NARCIS (Netherlands)

    Marquart, H.; Northage, C.; Money, C.

    2007-01-01

    The new European chemicals legislation REACH (Registration, Evaluation, Authorisation and restriction of Chemicals) requires the development of Exposure Scenarios describing the conditions and risk management measures needed for the safe use of chemicals. Such Exposure Scenarios should integrate

  12. On the relative role of meridional convergence and downwelling motion during the heat buildup leading to El Niño events

    Science.gov (United States)

    Ballester, Joan; Bordoni, Simona; Petrova, Desislava; Rodó, Xavier

    2015-04-01

    Despite steady progress in the understanding of El Niño-Southern Oscillation (ENSO) in the past decades, questions remain on the exact mechanisms leading to the onset of El Niño (EN) events. Several authors have highlighted how the subsurface heat buildup in the western tropical Pacific and the recharged phase in equatorial heat content are intrinsic elements of ENSO variability, leading to those changes in zonal wind stress, sea surface temperature and thermocline tilt that characterize the growing and mature phases of EN. Here we use an ensemble of ocean and atmosphere assimilation products to identify the mechanisms contributing to the heat buildup that precedes EN events by about 18-24 months on average. Anomalous equatorward subsurface mass convergence due to meridional Sverdrup transport is found to be an important mechanism of thermocline deepening near and to the east of the dateline. In the warm pool, instead, surface horizontal convergence and downwelling motion have a leading role in subsurface warming, since equatorward mass convergence is weaker and counterbalanced by subsurface zonal divergence. The picture emerging from our results highlights the complexity of the three dimensional dynamic and thermodynamic structure of the tropical Pacific during the heat buildup leading to EN events.

  13. Interpreting energy scenarios

    Science.gov (United States)

    Iyer, Gokul; Edmonds, James

    2018-05-01

    Quantitative scenarios from energy-economic models inform decision-making about uncertain futures. Now, research shows the different ways these scenarios are subsequently used by users not involved in their initial development. In the absence of clear guidance from modellers, users may place too much or too little confidence in scenario assumptions and results.

  14. An Inverse Function Least Square Fitting Approach of the Buildup Factor for Radiation Shielding Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Park, Chang Je [Sejong Univ., Seoul (Korea, Republic of); Alkhatee, Sari; Roh, Gyuhong; Lee, Byungchul [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    Dose absorption and energy absorption buildup factors are widely used in the shielding analysis. The dose rate of the medium is main concern in the dose buildup factor, however energy absorption is an important parameter in the energy buildup factors. ANSI/ANS-6.4.3-1991 standard data is widely used based on interpolation and extrapolation by means of an approximation method. Recently, Yoshida's geometric progression (GP) formulae are also popular and it is already implemented in QAD code. In the QAD code, two buildup factors are notated as DOSE for standard air exposure response and ENG for the response of the energy absorbed in the material itself. In this paper, a new least square fitting method is suggested to obtain a reliable buildup factors proposed since 1991. Total 4 datasets of air exposure buildup factors are used for evaluation including ANSI/ANS-6.4.3-1991, Taylor, Berger, and GP data. The standard deviation of the fitted data are analyzed based on the results. A new reverse least square fitting method is proposed in this study in order to reduce the fitting uncertainties. It adapts an inverse function rather than the original function by the distribution slope of dataset. Some quantitative comparisons are provided for concrete and lead in this paper, too. This study is focused on the least square fitting of existing buildup factors to be utilized in the point-kernel code for radiation shielding analysis. The inverse least square fitting method is suggested to obtain more reliable results of concave shaped dataset such as concrete. In the concrete case, the variance and residue are decreased significantly, too. However, the convex shaped case of lead can be applied to the usual least square fitting method. In the future, more datasets will be tested by using the least square fitting. And the fitted data could be implemented to the existing point-kernel codes.

  15. Gamma-ray energy buildup factor calculations and shielding effects of some Jordanian building structures

    Science.gov (United States)

    Sharaf, J. M.; Saleh, H.

    2015-05-01

    The shielding properties of three different construction styles, and building materials, commonly used in Jordan, were evaluated using parameters such as attenuation coefficients, equivalent atomic number, penetration depth and energy buildup factor. Geometric progression (GP) method was used to calculate gamma-ray energy buildup factors of limestone, concrete, bricks, cement plaster and air for the energy range 0.05-3 MeV, and penetration depths up to 40 mfp. It has been observed that among the examined building materials, limestone offers highest value for equivalent atomic number and linear attenuation coefficient and the lowest values for penetration depth and energy buildup factor. The obtained buildup factors were used as basic data to establish the total equivalent energy buildup factors for three different multilayer construction styles using an iterative method. The three styles were then compared in terms of fractional transmission of photons at different incident photon energies. It is concluded that, in case of any nuclear accident, large multistory buildings with five layers exterior walls, style A, could effectively attenuate radiation more than small dwellings of any construction style.

  16. A model for the build-up of disordered material in ion bombarded Si

    International Nuclear Information System (INIS)

    Nelson, R.S.

    1977-01-01

    A new model based on experimental observation is developed for the build-up of disordered material in ion bombarded silicon. The model assumes that disordered zones are created in a background of migrating point defects, these zones then act as neutral sinks for such defects which interact with the zones and cause recrystallization. A simple steady state rate theory is developed to describe the build-up of disordered material with ion dose as a function of temperature. In general the theory predicts two distinct behaviour patterns depending on the temperature and the ion mass, namely a linear build-up with dose to complete disorder for heavy bombarding ions and a build-up to saturation at a relatively low level for light ions such as protons. However, in some special circumstances a transition region is predicted where the build-up of disorder approximately follows a (dose)sup(1/2) relationship before reverting to a linear behaviour at high dose. (author)

  17. Exposure Buildup Factors for Heavy Metal Oxide Glass: A Radiation Shield

    DEFF Research Database (Denmark)

    Manonara, S. R.; Hanagodimath, S. M.; Gerward, Leif

    2011-01-01

    Gamma ray exposure buildup factors for three Heavy Metal Oxide (HMO) glass systems, viz. PbO-Bi2O3-B2O3, PbO-B2O3, and Bi2O3-B2O3 glasses are presented. The computations were done by interpolation method using the Geometric Progression fitting formula and ANSI/ANS-6.4.3 library for the energy ran...... of graphs. Buildup factors of these HMO glasses cannot be found in any standard database, but they are useful for practical calculations in gamma ray shield designs, and they also, help to determine and control the thickness of the shielding material used.......Gamma ray exposure buildup factors for three Heavy Metal Oxide (HMO) glass systems, viz. PbO-Bi2O3-B2O3, PbO-B2O3, and Bi2O3-B2O3 glasses are presented. The computations were done by interpolation method using the Geometric Progression fitting formula and ANSI/ANS-6.4.3 library for the energy range...... from 0.015 to 15 MeV, up to penetration depths of 40 mfp (mean free path). The buildup factors have been studied as functions of incident photon energy and penetration depth. The variations in the buildup factor, for all the glass systems, in different energy regions; have been presented in the form...

  18. The world in scenarios

    International Nuclear Information System (INIS)

    De Jong, A.; Roodenburg, H.

    1992-01-01

    As an introduction to this special issue 'Worlds of difference: Scenarios's for the economy, energy and the environment 1990-2015', an outline is given of the future of the world and the Netherlands, based on four scenarios. These scenarios are published in 'Scanning the future' in May 1992 by the CPB, the Dutch Central Planning Bureau. The Global Shift (GS) scenario is characterized by a very dynamic technological development, the free market perspective, strong economic growth in the Asian economies, and a relative economic regression in Western Europe. In the European Renaissance (ER) scenario the technological development is less dynamic and more gradual than in the GS scenario. The Balanced Growth (BG) scenario is dominated by a sustainable economic development and a strong technological dynamic development. The Global Crisis (GC) scenario shows a downward spiral in many areas, stagnating developments and fragile economies as results of the trends in the eighties. The first three scenarios are elaborated for the Netherlands. Also attention is paid to the aims and meaning of long-term scenarios. 2 figs., 2 tabs., 3 refs

  19. Holocene beach buildup and coastal aeolian sand incursions off the Nile littoral cell

    Science.gov (United States)

    Roskin, Joel; Sivan, Dorit; Shtienberg, Gilad; Porat, Naomi; Bookman, Revital

    2017-04-01

    Israel's coastal plain is abundant with sand originating from the Nile littoral cell. The inland windblown loose sand has formed 3-6 km wide lobe-like sand and dune fields currently comprised of foredunes, linear and northeasterly facing transverse and parabolic dunes that are currently stabilized by vegetation. This study reviews the architecture and history of the these dune fields aiming to: (a) Date the timings of beach accretion, and sand and dune incursions. (b) Discriminate between natural and human-induced forcing factors of sand mobilization and stabilization in time and space. (c) Present a model of the dunescape development. (d) Assess scenarios of sand transport in the future charcaterized by intense human impact and climate change. Luminescence ages, radiocarbon dates and relative ages from previously published geological and archaeological reports, historical texts, together with new optically stimulated luminescence (OSL) ages and stratigraphic and sedimentological data are analyzed. The deposition, mobilizations and preservation of the sand bodies, initially induced by the decline in sea level rise at 6-4 ka, were later controlled by historic land-use intensity and modern land-use/negligence practices. At 6 ka, beach sand buildup rapidly started. Where aeolianite ridges bordered the coast, pulses of sand with biogenic carbonate grains unconformably draped the ridges and rapidly consolidated into a distinct sandy calcarenite unit. Further east, sand sheets and low dunes partly pedogenized following their incursion, but did not cement. The water retention capacities of the sand sheets enabled the establishment of a sand-stabilizing vegetation cover that probably became an attractive environment for fuel and grazing. The growing Hellenistic-Roman-Byzantine ( 2.4-1.3 ka) populations probably led to increased consumption and massive destruction of sand stabilizing vegetation, enabling sand erodibility and mobilization during winter storms. The sand

  20. Contour Crafting Simulation Plan for Lunar Settlement Infrastructure Build-Up

    Science.gov (United States)

    Khoshnevis, B.; Carlson, A.; Leach N.; Thangavelu, M.

    2016-01-01

    Economically viable and reliable building systems and tool sets are being sought, examined and tested for extraterrestrial infrastructure buildup. This project focused on a unique architecture weaving the robotic building construction technology with designs for assisting rapid buildup of initial operational capability Lunar and Martian bases. The project aimed to study new methodologies to construct certain crucial infrastructure elements in order to evaluate the merits, limitations and feasibility of adapting and using such technologies for extraterrestrial application. Current extraterrestrial settlement buildup philosophy holds that in order to minimize the materials needed to be flown in, at great transportation costs, strategies that maximize the use of locally available resources must be adopted. Tools and equipment flown as cargo from Earth are proposed to build required infrastructure to support future missions and settlements on the Moon and Mars.

  1. Build-up of actinides in irradiated fuel rods of the ET-RR-1 reactor

    Energy Technology Data Exchange (ETDEWEB)

    Adib, M.; Naguib, K.; Morcos, H.N

    2001-09-01

    The content concentrations of actinides are calculated as a function of operating reactor regime and cooling time at different percentage of fuel burn-up. The build-up transmutation equations of actinides content in an irradiated fuel are solved numerically .A computer code BAC was written to operate on a PC computer to provide the required calculations. The fuel element of 10% {sup 235}U enrichment of ET-RR-1 reactor was taken as an example for calculations using the BAC code. The results are compared with other calculations for the ET-RR-1 fuel rod. An estimation of fissile build-up content of a proposed new fuel of 20% {sup 235}U enrichment for ET-RR-1 reactor is given. The sensitivity coefficients of build-up plutonium concentrations as a function of cross-section data uncertainties are also calculated.

  2. Paleochannel and beach-bar palimpsest topography as initial substrate for coralligenous buildups offshore Venice, Italy.

    Science.gov (United States)

    Tosi, Luigi; Zecchin, Massimo; Franchi, Fulvio; Bergamasco, Andrea; Da Lio, Cristina; Baradello, Luca; Mazzoli, Claudio; Montagna, Paolo; Taviani, Marco; Tagliapietra, Davide; Carol, Eleonora; Franceschini, Gianluca; Giovanardi, Otello; Donnici, Sandra

    2017-05-02

    We provide a model for the genesis of Holocene coralligenous buildups occurring in the northwestern Adriatic Sea offshore Venice at 17-24 m depth. High-resolution geophysical surveys and underwater SCUBA diving reconnaissance revealed meandering shaped morphologies underneath bio-concretionned rocky buildups. These morphologies are inferred to have been inherited from Pleistocene fluvial systems reactivated as tidal channels during the post- Last Glacial Maximum transgression, when the study area was a lagoon protected by a sandy barrier. The lithification of the sandy fossil channel-levee systems is estimated to have occurred at ca. 7 cal. ka BP, likely due to the interaction between marine and less saline fluids related to onshore freshwater discharge at sea through a sealed water-table. The carbonate-cemented sandy layers served as nucleus for subsequent coralligenous buildups growth.

  3. Monte Carlo correction factors for a Farmer 0.6 cm3 ion chamber dose measurement in the build-up region of the 6 MV clinical beam

    International Nuclear Information System (INIS)

    Pena, J; Sanchez-Doblado, F; Capote, R; Terron, J A; Gomez, F

    2006-01-01

    Reference dosimetry of photon fields is a well-established subject and currently available protocols (such as the IAEA TRS-398 and AAPM TG-51) provide methods for converting the ionization chamber (IC) reading into dose to water, provided reference conditions of charged particle equilibrium (CPE) are fulfilled. But these protocols cannot deal with the build-up region, where the lack of CPE limits the applicability of the cavity theorems and so the chamber correction factors become depth dependent. By explicitly including the IC geometry in the Monte Carlo simulations, depth-dependent dose correction factors are calculated for a PTW 30001 0.6 cm 3 ion chamber in the build-up region of the 6 MV photon beam. The corrected percentage depth dose (PDD) agrees within 2% with that measured using the NACP 02 plane-parallel ion chamber in the build-up region at depths greater than 0.4 cm, where the Farmer chamber wall reaches the phantom surface

  4. Comparison of build-up region doses in oblique tangential 6 MV photon beams calculated by AAA and CCC algorithms in breast Rando phantom

    Science.gov (United States)

    Masunun, P.; Tangboonduangjit, P.; Dumrongkijudom, N.

    2016-03-01

    The purpose of this study is to compare the build-up region doses on breast Rando phantom surface with the bolus covered, the doses in breast Rando phantom and also the doses in a lung that is the heterogeneous region by two algorithms. The AAA in Eclipse TPS and the collapsed cone convolution algorithm in Pinnacle treatment planning system were used to plan in tangential field technique with 6 MV photon beam at 200 cGy total doses in Breast Rando phantom with bolus covered (5 mm and 10 mm). TLDs were calibrated with Cobalt-60 and used to measure the doses in irradiation process. The results in treatment planning show that the doses in build-up region and the doses in breast phantom were closely matched in both algorithms which are less than 2% differences. However, overestimate of doses in a lung (L2) were found in AAA with 13.78% and 6.06% differences at 5 mm and 10 mm bolus thickness, respectively when compared with CCC algorithm. The TLD measurements show the underestimate in buildup region and in breast phantom but the doses in a lung (L2) were overestimated when compared with the doses in the two plannings at both thicknesses of the bolus.

  5. A 4-year clinical evaluation of direct composite build-ups for space closure after orthodontic treatment.

    Science.gov (United States)

    Demirci, Mustafa; Tuncer, Safa; Öztaş, Evren; Tekçe, Neslihan; Uysal, Ömer

    2015-12-01

    To evaluate the medium-term clinical performance of direct composite build-ups for diastema closures and teeth recontouring using a nano and a nanohybrid composite in combination with three- or two-step etch-and-rinse adhesives following treatment with fixed orthodontic appliances. A total of 30 patients (mean age, 19.5 years) received 147 direct composite additions for teeth recontouring and diastema closures. A nano and a nanohybrid composite (Filtek Supreme XT and CeramX Duo) were bonded to tooth structure by using a three-step (Scotchbond Multipurpose) or a two-step (XP Bond) etch and rinse adhesive. Ten out of 147 composite build-ups (composite addition) constituted tooth recontouring cases, and the remaining 137 constituted diastema closure cases. The restorations were evaluated by two experienced, calibrated examiners according to modified Ryge criteria at the following time intervals: baseline, 1, 2, 3, and 4 years. The 4-year survival rates were 92.8 % for Filtek Supreme XT/Scotchbond Multi-Purpose Plus and 93 % for CeramX Duo/XP Bond. Only ten restorations failed (5 Filtek Supreme XT and 5 CeramX Duo). Statistical analysis revealed no significant differences between the two composite-adhesive combinations with respect to color match, marginal discoloration, wear/loss of anatomical form, caries formation, marginal adaptation, and surface texture on comparing the five time periods (baseline, 1, 2, 3, and 4 years) The 4-year survival rates in the present study were favorable. The restorations exhibited excellent scores with regard to color match, marginal adaptation, surface texture, marginal discoloration, wear/loss of anatomical form, and caries formation, after 4 years of clinical evaluation. Clinical relevance An alternative clinical approach for correcting discrepancies in tooth size and form, such as performing direct composite restorations following fixed orthodontic treatment, may be an excellent and minimally invasive treatment.

  6. Food scenarios 2025

    DEFF Research Database (Denmark)

    Sundbo, Jon

    2016-01-01

    This article presents the results of a future study of the food sector. Two scenarios have been developed using a combination of: 1) a summary of the relevant scientific knowledge, 2) systematic scenario writing, 3) an expert-based Delphi technique, and 4) an expert seminar assessment. The two...... scenarios present possible futures at global, national (Denmark) and regional (Zealand, Denmark) levels. The main scenario is called ‘Food for ordinary days and celebrations’ (a combination of ‘High-technological food production − The functional society’ and ‘High-gastronomic food − The experience society...

  7. The Effect of Sloshing on a Tank Pressure Build-up Unit

    OpenAIRE

    Banne, Håvard Bolstad

    2017-01-01

    This thesis work has aimed to identify how sloshing will affect a liquefied natural gas (LNG) fuel tank. The physical nature of LNG means it needs to be kept cooled and pressurized in order to remain in a liquid state. By implementing a pressure build-up unit (PBU) it is possible to pressurize the tank vaporizing the tank’s contents, for the vapour then to return to tank in a loop, building pressure in the process. A tank pressure build-up unit has been built in the laboratory ...

  8. A method of the sensitivity analysis of build-up and decay of actinides

    International Nuclear Information System (INIS)

    Mitani, Hiroshi; Koyama, Kinji; Kuroi, Hideo

    1977-07-01

    To make sensitivity analysis of build-up and decay of actinides, mathematical methods related to this problem have been investigated in detail. Application of time-dependent perturbation technique and Bateman method to sensitivity analysis is mainly studied. For the purpose, a basic equation and its adjoint equation for build-up and decay of actinides are systematically solved by introducing Laplace and modified Laplace transforms and their convolution theorems. Then, the mathematical method of sensitivity analyses is formulated by the above technique; its physical significance is also discussed. Finally, application of eigenvalue-method is investigated. Sensitivity coefficients can be directly calculated by this method. (auth.)

  9. Basic principle of constant q/sub a/ current build-up in tokamaks

    International Nuclear Information System (INIS)

    Kikuchi, M.

    1985-05-01

    An analytic expression is derived such that the current profile shape is kept constant during the current build-up phase in tokamaks. The required conductivity profile is parametrized by two externally controllable parameters, I/sub p/ and a/sub p/ in the case of the Gaussian current profile. It is shown that a Gaussian current profile can be maintained for a realistically broad conductivity profile by using the constant q/sub a/ current build-up method even under the condition of a high I/sub p/

  10. Pennsylvanian carbonate buildups, Paradox basin: Increasing reserves in heterogeneous, shallow-shelf reservoirs

    Science.gov (United States)

    Montgomery, S.L.; Chidsey, T.C.; Eby, D.E.; Lorenz, D.M.; Culham, W.E.

    1999-01-01

    Productive carbonate buildups of Pennsylvanian age in the southern Paradox basin, Utah, contain up to 200 million bbl remaining oil potentially recoverable by enhanced recovery methods. These buildups comprise over 100 satellite fields to the giant Greater Aneth field, where secondary recovery operations thus far have been concentrated. Several types of satellite buildups exist and produce oil from the Desert Creek zone of the Paradox Formation. Many of the relevant fields have undergone early abandonment; wells in Desert Creek carbonate mounds commonly produce at very high initial rates (>1000 bbl/day) and then suffer precipitous declines. An important new study focused on the detailed characterization of five separate reservoirs has resulted in significant information relevant to their future redevelopment. Completed assessment of Anasazi field suggests that phylloid algal mounds, the major productive buildup type in this area, consist of ten separate lithotypes and can be described in terms of a two-level reservoir system with an underlying high-permeability mound-core interval overlain by a lower permeability but volumetrically larger supramound (mound capping) interval. Reservoir simulations and related performance predictions indicate that CO2 flooding of these reservoirs should have considerable success in recovering remaining oil reserves.Productive carbonate buildups of Pennsylvanian age in the southern Paradox basin, Utah, contain up to 200 million bbl remaining oil potentially recoverable by enhanced recovery methods. These buildups comprise over 100 satellite fields to the giant Greater Aneth field, where secondary recovery operations thus far have been concentrated. Several types of satellite buildups exist and produce oil from the Desert Creek zone of the Paradox Formation. Many of the relevant fields have undergone early abandonment; wells in Desert Creek carbonate mounds commonly produce at very high initial rates (>1000 bbl/day) and then suffer

  11. Alternatives for contaminant control during MFTF plasma buildup

    International Nuclear Information System (INIS)

    Khan, J.M.; Valby, L.E.

    1979-01-01

    The MFTF mirror device considers all low-energy species to be contaminants, since their primary effect is to erode the plasma boundary by charge-exchange reactions. Confinement for other than hydrogen isotypes is far from complete and confinement time is hardly more than transit time from the source to the end wall. The brevity of the confinement time makes it all the more necessary to prevent any contamination which might further reduce it. At Livermore, the historical solution to contaminant control has been to evaporate titanium onto cold surfaces. An alternative to this approach and its implications are considered

  12. A Measurement and Analysis of Buildup Region Dose for Open Field Photon Beams (Cobalt-60 through 24 MV)

    International Nuclear Information System (INIS)

    McCullough, Edwin C.

    2015-01-01

    The central axis depth dose in the build-up region (surface to d_m_a_x) of single open field photon beams (cobalt-60 through 24 MV) has been measured utilizing parallel plate and extrapolation chamber methodology. These data were used to derive, for a prescription dose of 100 cGy, values of surface dose, the maximum value of dose along the central axis (D_m_a_x) and the depth (nearest the surface) at which 90% of the prescription dose occurs (d_9_0). For both single and parallel opposed pair (POP) open field configurations, data are presented at field sizes of 5 × 5, 15 × 15 and 25 × 25 cm"2 for prescription depths of 10, 15 and 20 cm (midplane for POP). For the treatment machines, field sizes, and prescription depths studied, it is possible to conclude that: for single open field irradiation, surface dose values (as a percentage of the prescription dose) can be either low (<10%) or comparable to the prescription dose itself; for POP open fields, surface dose values are relatively independent of photon energy and midplane depth, and range between 30% and 70% of prescription dose, being principally dependent on field size; the depth of the initial 90 cGy point for a prescription dose of 100 cGy, d_9_0, was larger for POP fields. For either single or POP open field treatments, d_9_0 was always less than 22 mm, while for 6 MV or less, values of d_9_0 were less than 4 mm; D_m_a_x values can be very large (e.g., above 300 cGy) for certain treatment situations and are reduced significantly for POP treatments; for open field POP treatments, the percent reduction in D_m_a_x with each increment in beam energy above 10 MV is reduced over that seen at 10 MV or less and, possibly, this further reduction may be clinically insignificant; for open field POP treatments, changes in surface dose, d_9_0 and D_m_a_x with beam energy above 10 MV do not suggest, with regard to these specific build-up curve parameters, any obvious advantage for treatment with beam energies greater

  13. From scenarios to components

    NARCIS (Netherlands)

    Fahland, D.

    2010-01-01

    Scenario-based modeling has evolved as an accepted paradigm for developing complex systems of various kinds. Its main purpose is to ensure that a system provides desired behavior to its users. A scenario is generally understood as a behavioral requirement, denoting a course of actions that shall

  14. Nuclear Security Futures Scenarios

    International Nuclear Information System (INIS)

    Keller, Elizabeth James Kistin; Warren, Drake Edward; Hayden, Nancy Kay; Passell, Howard D.; Malczynski, Leonard A.; Backus, George A.

    2017-01-01

    This report provides an overview of the scenarios used in strategic futures workshops conducted at Sandia on September 21 and 29, 2016. The workshops, designed and facilitated by analysts in Center 100, used scenarios to enable thought leaders to think collectively about the changing aspects of global nuclear security and the potential implications for the US Government and Sandia National Laboratories.

  15. Scenario-based strategizing

    DEFF Research Database (Denmark)

    Lehr, Thomas; Lorenz, Ullrich; Willert, Markus

    2017-01-01

    For over 40 years, scenarios have been promoted as a key technique for forming strategies in uncertain en- vironments. However, many challenges remain. In this article, we discuss a novel approach designed to increase the applicability of scenario-based strategizing in top management teams. Drawi...... Ministry) and a firm affected by disruptive change (Bosch, leading global supplier of technology and solutions)....

  16. Nuclear Security Futures Scenarios.

    Energy Technology Data Exchange (ETDEWEB)

    Keller, Elizabeth James Kistin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Warren, Drake Edward [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hayden, Nancy Kay [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Passell, Howard D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Malczynski, Leonard A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Backus, George A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-01-01

    This report provides an overview of the scenarios used in strategic futures workshops conducted at Sandia on September 21 and 29, 2016. The workshops, designed and facilitated by analysts in Center 100, used scenarios to enable thought leaders to think collectively about the changing aspects of global nuclear security and the potential implications for the US Government and Sandia National Laboratories.

  17. Understanding the build-up of supermassive black holes and galaxies

    Science.gov (United States)

    Carrera, Francisco; Ueda, Yoshihiro; Georgakakis, Antonis

    2016-07-01

    One of the main open questions in modern Astrophysics is understanding the coupled growth of supermassive black holes by accretion and their host galaxies via star formation, from their peak at redshifts z~ 1-4 to the present time. The generic scenario proposed involves an early phase of intense black hole growth that takes place behind large obscuring columns of inflowing dust and gas clouds. It is postulated that this is followed by a blow-out stage during which some form of AGN feedback controls the fate of the interstellar medium and hence, the evolution of the galaxy. X-rays are essential for testing this scenario as they uniquely probe AGN at both the early heavily obscured stage and the later blow-out phase. X-ray spectral analysis can identify the smoking gun evidence of heavily obscured black hole growth (e.g. intense iron Kalpha line). It therefore provides the most robust method for compiling clean samples of deeply shrouded AGN with well-defined selection functions and unbiased determinations of their intrinsic properties (accretion luminosity, obscuring column). X-rays are also the best window for studying in detail AGN feedback. This process ultimately originates in the innermost regions close to the supermassive black hole and is dominated, in terms of energy and mass flux, by highly ionisedmaterial that remains invisible at other wavelengths. The most important epoch for investigating the relation between AGN and galaxies is the redshift range z~1-4, when most black holes and stars we see in the present-day Universe were put in place. Unfortunately, exhaustive efforts with current high-energy telescopes only scrape the tip of the iceberg of the most obscured AGN population. Moreover, Xray studies of the incidence, nature and energetics of AGN feedback are limited to the local Universe. The Athena observatory will provide the technological leap required for a breakthrough in our understanding of AGN and galaxy evolution at the heyday of the Universe

  18. Integrative Scenario Development

    Directory of Open Access Journals (Sweden)

    Joerg A. Priess

    2014-03-01

    Full Text Available Scenarios are employed to address a large number of future environmental and socioeconomic challenges. We present a conceptual framework for the development of scenarios to integrate the objectives of different stakeholder groups. Based on the framework, land-use scenarios were developed to provide a common base for further research. At the same time, these scenarios assisted regional stakeholders to bring forward their concerns and arrive at a shared understanding of challenges between scientific and regional stakeholders, which allowed them to eventually support regional decision making. The focus on the integration of views and knowledge domains of different stakeholder groups, such as scientists and practitioners, required rigorous and repeated measures of quality control. The application of the integrative concept provided products for both stakeholder groups, and the process of scenario development facilitated cooperation and learning within both the scientist and practitioner groups as well as between the two groups.

  19. Future climate and surface mass balance of Svalbard glaciers in an RCP8.5 climate scenario: a study with the regional climate model MAR forced by MIROC5

    Science.gov (United States)

    Lang, C.; Fettweis, X.; Erpicum, M.

    2015-05-01

    We have performed a future projection of the climate and surface mass balance (SMB) of Svalbard with the MAR (Modèle Atmosphérique Régional) regional climate model forced by MIROC5 (Model for Interdisciplinary Research on Climate), following the RCP8.5 scenario at a spatial resolution of 10 km. MAR predicts a similar evolution of increasing surface melt everywhere in Svalbard followed by a sudden acceleration of melt around 2050, with a larger melt increase in the south compared to the north of the archipelago. This melt acceleration around 2050 is mainly driven by the albedo-melt feedback associated with the expansion of the ablation/bare ice zone. This effect is dampened in part as the solar radiation itself is projected to decrease due to a cloudiness increase. The near-surface temperature is projected to increase more in winter than in summer as the temperature is already close to 0 °C in summer. The model also projects a stronger winter west-to-east temperature gradient, related to the large decrease of sea ice cover around Svalbard. By 2085, SMB is projected to become negative over all of Svalbard's glaciated regions, leading to the rapid degradation of the firn layer.

  20. Effect of heat build-up on carbon emissions in chimato compost piles ...

    African Journals Online (AJOL)

    A study was conducted to determine impacts of heat build-up of chimato compost piles TD0, TD20, TD40, TD50, TD60, TD80 and TD100, made by blending maize stalks with 0, 20, 40, 50, 60, 80 and 100% Tithonia diversifolia, respectively, on carbon losses and emissions during composting. Compost piles temperatures ...

  1. "Testing during Study Insulates against the Buildup of Proactive Interference": Correction

    Science.gov (United States)

    Szpunar, Karl K.; McDermott, Kathleen B.; Roedigger, Henry L., III

    2009-01-01

    Reports an error in "Testing during study insulates against the buildup of proactive interference" by Karl K. Szpunar, Kathleen B. McDermott and Henry L. Roediger III ("Journal of Experimental Psychology: Learning, Memory, and Cognition," 2008[Nov], Vol 34[6], 1392-1399). Incorrect figures were printed due to an error in the…

  2. Energy absorption buildup factors for thermoluminescent dosimetric materials and their tissue equivalence

    DEFF Research Database (Denmark)

    Manohara, S.R.; Hanagodimath, S.M.; Gerward, Leif

    2010-01-01

    Gamma ray energy-absorption buildup factors were computed using the five-parameter geometric progression (G-P) fitting formula for seven thermoluminescent dosimetric (TLD) materials in the energy range 0.015-15 MeV, and for penetration depths up to 40 mfp (mean free path). The generated energy-absorption...

  3. Effect of finite sample dimensions and total scatter acceptance angle on the gamma ray buildup factor

    International Nuclear Information System (INIS)

    Singh, Sukhpal; Kumar, Ashok; Singh, Charanjeet; Thind, Kulwant Singh; Mudahar, Gurmel S.

    2008-01-01

    The simultaneous variation of gamma ray buildup factors with absorber thickness (up to 6.5 mfp) and total scatter acceptance angle (which is the sum of incidence and exit beam divergence) in the media of high volume flyash concrete and water was studied experimentally using a point isotropic 137 Cs source

  4. Monte Carlo simulation of photon buildup factors for shielding materials in diagnostic x-ray facilities

    International Nuclear Information System (INIS)

    Kharrati, Hedi; Agrebi, Amel; Karoui, Mohamed Karim

    2012-01-01

    Purpose: A simulation of buildup factors for ordinary concrete, steel, lead, plate glass, lead glass, and gypsum wallboard in broad beam geometry for photons energies from 10 keV to 150 keV at 5 keV intervals is presented. Methods: Monte Carlo N-particle radiation transport computer code has been used to determine the buildup factors for the studied shielding materials. Results: An example concretizing the use of the obtained buildup factors data in computing the broad beam transmission for tube potentials at 70, 100, 120, and 140 kVp is given. The half value layer, the tenth value layer, and the equilibrium tenth value layer are calculated from the broad beam transmission for these tube potentials. Conclusions: The obtained values compared with those calculated from the published data show the ability of these data to predict shielding transmission curves. Therefore, the buildup factors data can be combined with primary, scatter, and leakage x-ray spectra to provide a computationally based solution to broad beam transmission for barriers in shielding x-ray facilities.

  5. Monte Carlo simulation of photon buildup factors for shielding materials in diagnostic x-ray facilities.

    Science.gov (United States)

    Kharrati, Hedi; Agrebi, Amel; Karoui, Mohamed Karim

    2012-10-01

    A simulation of buildup factors for ordinary concrete, steel, lead, plate glass, lead glass, and gypsum wallboard in broad beam geometry for photons energies from 10 keV to 150 keV at 5 keV intervals is presented. Monte Carlo N-particle radiation transport computer code has been used to determine the buildup factors for the studied shielding materials. An example concretizing the use of the obtained buildup factors data in computing the broad beam transmission for tube potentials at 70, 100, 120, and 140 kVp is given. The half value layer, the tenth value layer, and the equilibrium tenth value layer are calculated from the broad beam transmission for these tube potentials. The obtained values compared with those calculated from the published data show the ability of these data to predict shielding transmission curves. Therefore, the buildup factors data can be combined with primary, scatter, and leakage x-ray spectra to provide a computationally based solution to broad beam transmission for barriers in shielding x-ray facilities.

  6. THE BUILDUP OF A SCALE-FREE PHOTOSPHERIC MAGNETIC NETWORK

    Energy Technology Data Exchange (ETDEWEB)

    Thibault, K.; Charbonneau, P. [Departement de Physique, Universite de Montreal, 2900 Edouard-Montpetit, Montreal, Quebec H3C 3J7 (Canada); Crouch, A. D., E-mail: kim@astro.umontreal.ca-a, E-mail: paulchar@astro.umontreal.ca-b, E-mail: ash@cora.nwra.com-c [CORA/NWRA, 3380 Mitchell Lane, Boulder, CO 80301 (United States)

    2012-10-01

    We use a global Monte Carlo simulation of the formation of the solar photospheric magnetic network to investigate the origin of the scale invariance characterizing magnetic flux concentrations visible on high-resolution magnetograms. The simulations include spatially and temporally homogeneous injection of small-scale magnetic elements over the whole photosphere, as well as localized episodic injection associated with the emergence and decay of active regions. Network elements form in response to cumulative pairwise aggregation or cancellation of magnetic elements, undergoing a random walk on the sphere and advected on large spatial scales by differential rotation and a poleward meridional flow. The resulting size distribution of simulated network elements is in very good agreement with observational inferences. We find that the fractal index and size distribution of network elements are determined primarily by these post-emergence surface mechanisms, and carry little or no memory of the scales at which magnetic flux is injected in the simulation. Implications for models of dynamo action in the Sun are briefly discussed.

  7. THE BUILDUP OF A SCALE-FREE PHOTOSPHERIC MAGNETIC NETWORK

    International Nuclear Information System (INIS)

    Thibault, K.; Charbonneau, P.; Crouch, A. D.

    2012-01-01

    We use a global Monte Carlo simulation of the formation of the solar photospheric magnetic network to investigate the origin of the scale invariance characterizing magnetic flux concentrations visible on high-resolution magnetograms. The simulations include spatially and temporally homogeneous injection of small-scale magnetic elements over the whole photosphere, as well as localized episodic injection associated with the emergence and decay of active regions. Network elements form in response to cumulative pairwise aggregation or cancellation of magnetic elements, undergoing a random walk on the sphere and advected on large spatial scales by differential rotation and a poleward meridional flow. The resulting size distribution of simulated network elements is in very good agreement with observational inferences. We find that the fractal index and size distribution of network elements are determined primarily by these post-emergence surface mechanisms, and carry little or no memory of the scales at which magnetic flux is injected in the simulation. Implications for models of dynamo action in the Sun are briefly discussed.

  8. The Buildup of a Scale-free Photospheric Magnetic Network

    Science.gov (United States)

    Thibault, K.; Charbonneau, P.; Crouch, A. D.

    2012-10-01

    We use a global Monte Carlo simulation of the formation of the solar photospheric magnetic network to investigate the origin of the scale invariance characterizing magnetic flux concentrations visible on high-resolution magnetograms. The simulations include spatially and temporally homogeneous injection of small-scale magnetic elements over the whole photosphere, as well as localized episodic injection associated with the emergence and decay of active regions. Network elements form in response to cumulative pairwise aggregation or cancellation of magnetic elements, undergoing a random walk on the sphere and advected on large spatial scales by differential rotation and a poleward meridional flow. The resulting size distribution of simulated network elements is in very good agreement with observational inferences. We find that the fractal index and size distribution of network elements are determined primarily by these post-emergence surface mechanisms, and carry little or no memory of the scales at which magnetic flux is injected in the simulation. Implications for models of dynamo action in the Sun are briefly discussed.

  9. Effects of internal and external scatter on the build-up characteristics of Monte Carlo calculated absorbed dose for electron irradiation

    International Nuclear Information System (INIS)

    Lin, H.; Wu, DS.; Wu, AD.

    2005-01-01

    The effects of internal and external scatter on surface, build-up and depth dose characteristics simulated by Monte Carlo code EGSnrc for varying field size and SSD for a 10 MeV monoenergetic electron beam with and without an accelerator model are extensively studied in this paper. In particular, sub-millimetre surface PDD was investigated. The percentage depth doses affected significantly by the external scatter show a larger build-up dose. A forward shifted Dmax depth and a sharper fall-off region compared to PDDs with only internal scatter considered. The surface dose with both internal and external scatter shows a marked decrease at 110 cm SSD, and then slight further changes with the increasing SSD since few external scattered particles from accelerator model can reach the phantom for large SSDs. The sharp PDD increase for the 5 cm x 5 cm field compared to other fields seen when only internal scatter is considered is significantly less when external scatter is also present. The effect of external scatter on surface PDD is more pronounced for large fields than small fields (5 cm x 5 cm field)

  10. A study of the energy absorption and exposure buildup factors of some anti-inflammatory drugs

    International Nuclear Information System (INIS)

    Ekinci, Neslihan; Kavaz, Esra; Özdemir, Yüksel

    2014-01-01

    Human radiation exposure is increasing due to radiation development in science and technology. The development of radioprotective agents is important for protecting patients from the side effects of radiotherapy and for protecting the public from unwanted irradiation. Radioprotective agents are used to reduce the damage caused by radiation in healthy tissues. There are several classes of radioprotective compounds that are under investigation. Analgesics and anti-inflammatory compounds are being considered for treating or preventing the effects of damage due to radiation exposure, or for increasing the chance of survival after exposure to a high dose of radiation. In this study, we investigated the radioprotective effects of some analgesic and anti-inflammatory compounds by evaluating buildup factors. The gamma ray energy absorption (EABF) and exposure buildup factors (EBF) were calculated to select compounds in a 0.015–15 MeV energy region up to a penetration depth of 40 mfp (mean free path). Variations of EABF and EBF with incident photon energy and penetration depth elements were also investigated. Significant variations in both EABF and EBF values were observed for several compounds at the moderate energy region. At energies below 0.15 MeV, EABF and EBF values increased with decreasing equivalent atomic number (Z eq ) of the samples. In addition, EABF and EBF were the largest for ibuprofen, aspirin, paracetamol, naproxen and ketoprofen at 0.05 and 0.06 MeV, respectively, and the EABF value was 0.1 MeV for aceclofenac. From these results, we concluded that the buildup of photons is less for aceclofenac compared to other materials. - Highlights: • Buildup factors of anti-inflammatory drugs have been calculated by a G-P fitting method. • Z eff of diclofenac was observed higher than other compounds. • It was found that buildup of photons is less for aceclofenac and diclofenac. • It would be appealing to use aceclofenac and diclofenac as radioprotective

  11. JAXA's Space Exploration Scenario

    Science.gov (United States)

    Sato, N. S.

    2018-04-01

    Japan Aerospace Exploration Agency (JAXA) has been studying space exploration scenario, including human exploration for Japan since 2015, which encompasses goals, knowledge gap assessment, and architecture. assessment, and technology roadmap.

  12. Learning Through Scenario Planning

    DEFF Research Database (Denmark)

    Balarezo, Jose

    level variables, this research corrects this void by investigating the dynamics of organizational learning through the lenses of a corporate scenario planning process. This enhances our scientific understanding of the role that scenario planning might play in the context of organizational learning......This project investigates the uses and effects of scenario planning in companies operating in highly uncertain and dynamic environments. Whereas previous research on scenario planning has fallen short of providing sufficient evidence of its mechanisms and effects on individual or organizational...... and strategic renewal. Empirical evidence of the various difficulties that learning flows has to overcome as it journeys through organizational and hierarchical levels are presented. Despite various cognitive and social psychological barriers identified along the way, the results show the novel...

  13. Integrated transportation scenario planning.

    Science.gov (United States)

    2010-07-01

    Regional land usetransportation scenario planning emerged as a planning technique in U.S. : metropolitan areas in the 1990s. Building on prior work by this research team, this study continues : to track the development and expansion of regional sc...

  14. Build-up and wash-off dynamics of atmospherically derived Cu, Pb, Zn and TSS in stormwater runoff as a function of meteorological characteristics.

    Science.gov (United States)

    Murphy, Louise U; Cochrane, Thomas A; O'Sullivan, Aisling

    2015-03-01

    Atmospheric pollutants deposited on impermeable surfaces can be an important source of pollutants to stormwater runoff; however, modelling atmospheric pollutant loads in runoff has rarely been done, because of the challenges and uncertainties in monitoring their contribution. To overcome this, impermeable concrete boards (≈ 1m(2)) were deployed for 11 months in different locations within an urban area (industrial, residential and airside) throughout Christchurch, New Zealand, to capture spatially distributed atmospheric deposition loads in runoff over varying meteorological conditions. Runoff was analysed for total and dissolved Cu, Zn, Pb, and total suspended solids (TSS). Mixed-effect regression models were developed to simulate atmospheric pollutant loads in stormwater runoff. In addition, the models were used to explain the influence of different meteorological characteristics (e.g. antecedent dry days and rain depth) on pollutant build-up and wash-off dynamics. The models predicted approximately 53% to 69% of the variation in pollutant loads and were successful in predicting pollutant-load trends over time which can be useful for general stormwater planning processes. Results from the models illustrated the importance of antecedent dry days on pollutant build-up. Furthermore, results indicated that peak rainfall intensity and rain duration had a significant relationship with TSS and total Pb, whereas, rain depth had a significant relationship with total Cu and total Zn. This suggested that the pollutant speciation phase plays an important role in surface wash-off. Rain intensity and duration had a greater influence when the pollutants were predominantly in their particulate phase. Conversely, rain depth exerted a greater influence when a high fraction of the pollutants were predominantly in their dissolved phase. For all pollutants, the models were represented by a log-arctan relationship for pollutant build-up and a log-log relationship for pollutant wash

  15. Scenarios and innovative systems

    International Nuclear Information System (INIS)

    2001-11-01

    The purpose of this workshop is to present to the GEDEON community the scenarios for the deployment of innovative nuclear solutions. Both steady state situations and possible transitions from the present to new reactors and fuel cycles are considered. Innovative systems that satisfy improved natural resource utilization and waste minimization criteria will be described as well as the R and D orientations of various partners. This document brings together the transparencies of 17 communications given at this workshop: general policy for transmutation and partitioning; Amster: a molten salt reactor (MSR) concept; MSR capabilities; potentials and capabilities of accelerator driven systems (ADS); ADS demonstrator interest as an experimental facility; innovative systems: gas coolant technologies; Pu management in EPR; scenarios with thorium fuel; scenarios at the equilibrium state; scenarios for transition; partitioning and specific conditioning; management of separated radio-toxic elements; European programs; DOE/AAA (Advanced Accelerator Applications) program; OECD scenario studies; CEA research programs and orientations; partitioning and transmutation: an industrial point of view. (J.S.)

  16. SCENARIO PLANNING AS LEARNING

    Directory of Open Access Journals (Sweden)

    Antonio Lourenço Junior

    2010-10-01

    Full Text Available Scenario Planning has been increasingly used, from its introduction to the decision process as effective tools to test decisions, and improve performance in a dynamic environment (Chermack, 2005. The purpose of this article is to demonstrate the potential of an experimental Scenario Planning Model to mobilize, encourage and add more content to the organization’s decision making process – mainly with respect to Strategic Plans of two governmental institutions, a pharmaceutical company and a technology education foundation.  This study describes the application stages of a hybrid scenario-planning model – herein referred to as Planning as Learning – via action-research, showing the scenarios resulting from the experiment and describes the main results of an assessment of such practice. In order to do that, two well-established Scenario Planning models (Prospective school and Shell’s model were analyzed. They were used as a reference for the proposition and application of an experimental model in the two study objects. A questionnaire was used to assess the technique impact. It was possible to obtain high levels of reliability. In-depth interviews were also conducted with the participants. At the end, the results confirmed the model efficiency as a basis for decision making in the competitive environment in which the two institutions are inserted, also to encourage the learning process as a group, as observed throughout the work.

  17. Scenarios for Gluino Coannihilation

    CERN Document Server

    Ellis, John; Luo, Feng; Olive, Keith A

    2016-01-01

    We study supersymmetric scenarios in which the gluino is the next-to-lightest supersymmetric particle (NLSP), with a mass sufficiently close to that of the lightest supersymmetric particle (LSP) that gluino coannihilation becomes important. One of these scenarios is the MSSM with soft supersymmetry-breaking squark and slepton masses that are universal at an input GUT renormalization scale, but with non-universal gaugino masses. The other scenario is an extension of the MSSM to include vector-like supermultiplets. In both scenarios, we identify the regions of parameter space where gluino coannihilation is important, and discuss their relations to other regions of parameter space where other mechanisms bring the dark matter density into the range allowed by cosmology. In the case of the non-universal MSSM scenario, we find that the allowed range of parameter space is constrained by the requirement of electroweak symmetry breaking, the avoidance of a charged LSP and the measured mass of the Higgs boson, in parti...

  18. Scenarios for gluino coannihilation

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, John [Theoretical Particle Physics and Cosmology Group, Department of Physics, King’s College London, London, WC2R 2LS United Kingdom (United Kingdom); Theory Division, CERN,Geneva 23, CH-1211 (Switzerland); Evans, Jason L. [School of Physics and Astronomy, University of Minnesota,Minneapolis, MN, 55455 (United States); William I. Fine Theoretical Physics Institute, School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, 55455 (United States); Luo, Feng [Theory Division, CERN,Geneva 23, CH-1211 (Switzerland); Olive, Keith A. [School of Physics and Astronomy, University of Minnesota,Minneapolis, MN, 55455 (United States); William I. Fine Theoretical Physics Institute, School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, 55455 (United States)

    2016-02-11

    We study supersymmetric scenarios in which the gluino is the next-to-lightest supersymmetric particle (NLSP), with a mass sufficiently close to that of the lightest supersymmetric particle (LSP) that gluino coannihilation becomes important. One of these scenarios is the MSSM with soft supersymmetry-breaking squark and slepton masses that are universal at an input GUT renormalization scale, but with non-universal gaugino masses. The other scenario is an extension of the MSSM to include vector-like supermultiplets. In both scenarios, we identify the regions of parameter space where gluino coannihilation is important, and discuss their relations to other regions of parameter space where other mechanisms bring the dark matter density into the range allowed by cosmology. In the case of the non-universal MSSM scenario, we find that the allowed range of parameter space is constrained by the requirement of electroweak symmetry breaking, the avoidance of a charged LSP and the measured mass of the Higgs boson, in particular, as well as the appearance of other dark matter (co)annihilation processes. Nevertheless, LSP masses m{sub χ}≲8 TeV with the correct dark matter density are quite possible. In the case of pure gravity mediation with additional vector-like supermultiplets, changes to the anomaly-mediated gluino mass and the threshold effects associated with these states can make the gluino almost degenerate with the LSP, and we find a similar upper bound.

  19. Regional climate change scenarios

    International Nuclear Information System (INIS)

    Somot, S.

    2005-01-01

    Because studies of the regional impact of climate change need higher spatial resolution than that obtained in standard global climate change scenarios, developing regional scenarios from models is a crucial goal for the climate modelling community. The zoom capacity of ARPEGE-Climat, the Meteo-France climate model, allows use of scenarios with a horizontal resolution of about 50 km over France and the Mediterranean basin. An IPCC-A2 scenario for the end of the 21. century in France shows higher temperatures in each season and more winter and less summer precipitation than now. Tuning the modelled statistical distributions to observed temperature and precipitation allows us to study changes in the frequency of extreme events between today's climate and that at the end of century. The frequency of very hot days in summer will increase. In particular, the frequency of days with a maximum temperature above 35 deg C will be multiplied by a factor of 10, on average. In our scenario, the Toulouse area and Provence might see one quarter of their summer days with a maximum temperature above 35 deg C. (author)

  20. Correlation between Co-60 and X-ray exposures on radiation-induced charge buildup in silicon-on-insulator buried oxides

    International Nuclear Information System (INIS)

    Schwank, James R.; Shaneyfelt, Marty R.; Loemker, Rhonda Ann; Draper, Bruce L.; Dodd, Paul E.; Witczak, StevenN C.; Riewe, Leonard Charles; Ferlet-Cavrois, V.; Paillet, P.; Leray, J.-L.; Fleetwood, D.M.

    2000-01-01

    Large differences in charge buildup in SOI buried oxides can result between x-ray and Co-60 irradiations. The effects of bias configuration and substrate type on charge buildup and hardness assurance issues are explored

  1. Exposure buildup factors for a cobalt-60 point isotropic source for single and two layer slabs

    International Nuclear Information System (INIS)

    Chakarova, R.

    1992-01-01

    Exposure buildup factors for point isotropic cobalt-60 sources are calculated by the Monte Carlo method with statistical errors ranging from 1.5 to 7% for 1-5 mean free paths (mfp) thick water and iron single slabs and for 1 and 2 mfp iron layers followed by water layers 1-5 mfp thick. The computations take into account Compton scattering. The Monte Carlo data for single slab geometries are approximated by Geometric Progression formula. Kalos's formula using the calculated single slab buildup factors may be applied to reproduce the data for two-layered slabs. The presented results and discussion may help when choosing the manner in which the radiation field gamma irradiation units will be described. (author)

  2. Calculation of point isotropic buildup factors of gamma rays for water and lead

    Directory of Open Access Journals (Sweden)

    A. S. H.

    2001-12-01

    Full Text Available   Exposure buildup factors for water and lead have been calculated by the Monte-Carlo method for an isotropic point source in an infinite homogeneous medium, using the latest cross secions available on the Internet. The types of interactions considered are ,photoelectric effect, incoherent (or bound-electron Compton. Scattering, coherent (or Rayleigh scattering and pair production. Fluorescence radiations have also been taken into acount for lead. For each material, calculations were made at 10 gamma ray energies in the 40 keV to 10 MeV range and up to penetration depths of 10 mean free paths at each energy point. The results presented in this paper can be considered as modified gamma ray exposure buildup factors and be used in radiation shielding designs.

  3. Energy buildup factor for ICRU 33 sphere surrounded by an air layer

    International Nuclear Information System (INIS)

    Ochiana, G.; Oncescu, M.

    1994-01-01

    The buildup factor due to the air surrounding an ICRU 33 sphere is a desirable quantity in the assessment of the air kerma rate for external exposure to gamma emitters distributed on the ground. A Monte Carlo algorithm has been developed to perform the photon transport calculation within the air layer around the sphere. The energy buildup factor due to the air layer has been calculated for an extended radioactive source - the contaminated ground. The transport of photons within the air layer surrounding a sphere -ICRU 33 phantom - is done by calculating separately the energies deposited by photons into the sphere when this one is in vacuum and when it is surrounded by the air, respectively. The results are given for an air layer of 100 m thickness and photon energy between 0.01 and 3.0 MeV. (Author) 1 Fig., 1 Tab., 9 Refs

  4. Gamma-ray energy absorption and exposure buildup factor studies in some human tissues with endometriosis

    Energy Technology Data Exchange (ETDEWEB)

    Kurudirek, Murat, E-mail: mkurudirek@gmail.co [Faculty of Science, Department of Physics, Ataturk University, 25240 Erzurum (Turkey); Dogan, Bekir [Faculty of Science, Department of Physics, Ataturk University, 25240 Erzurum (Turkey); Ingec, Metin [Faculty of Medicine, Department of Obstetrics and Gynecology, Ataturk University, 25240 Erzurum (Turkey); Ekinci, Neslihan; Ozdemir, Yueksel [Faculty of Science, Department of Physics, Ataturk University, 25240 Erzurum (Turkey)

    2011-02-15

    Human tissues with endometriosis have been analyzed in terms of energy absorption (EABF) and exposure (EBF) buildup factors using the five-parameter geometric progression (G-P) fitting formula in the energy region 0.015-15 MeV up to a penetration depth of 40 mfp (mean free path). Chemical compositions of the tissue samples were determined using a wavelength dispersive X-ray fluorescence spectrometer (WDXRFS). Possible conclusions were drawn due to significant variations in EABF and EBF for the selected tissues when photon energy, penetration depth and chemical composition changed. Buildup factors so obtained may be of use when the method of choice for treatment of endometriosis is radiotherapy.

  5. Effect of tungsten-187 in primary coolant on dose rate build-up in Vandellos 2

    International Nuclear Information System (INIS)

    Fernandez Lillo, E.; Llovet, R.; Boronat, M.

    1994-01-01

    The present work proposes a relationship between the Cobalt-60 piping deposited activity and the relatively high levels of Tungsten-187 in the coolant of Vandellos 2. The conclusions of this work can be applicable to other plants, since it proposes a tool to estimate and quantify the contribution of stellite to the generation of Cobalt-60 and the radiation dose build-up. (authors). 7 figs., 6 refs

  6. MIV Project: Mission scenario

    DEFF Research Database (Denmark)

    Ravazzotti, Mariolina T.; Jørgensen, John Leif; Thuesen, Gøsta

    1997-01-01

    Under the ESA contract #11453/95/NL/JG(SC), aiming at assessing the feasibility of Rendez-vous and docking of unmanned spacecrafts, a msiision scenario was defined. This report describes the secquence of manouvres and task allocations for such missions.......Under the ESA contract #11453/95/NL/JG(SC), aiming at assessing the feasibility of Rendez-vous and docking of unmanned spacecrafts, a msiision scenario was defined. This report describes the secquence of manouvres and task allocations for such missions....

  7. Scenario group summary

    International Nuclear Information System (INIS)

    Thorndike, A.

    1976-01-01

    A scenario is given for ISABELLE which provides a plausible sequence of events from FY 1980 to 1990. No doubt reality will be quite different. The scenario is based on the construction schedule of the 1976 proposal. Assembly and testing of the accelerator will occur until the end of FY 1983, and the next six years will provide pp interactions for the initial high energy physics research. By 1990 any temporary conditions associated with start-up of ISABELLE should be a thing of the past and all experimental capabilities fully utilized

  8. Scenario group summary

    International Nuclear Information System (INIS)

    Thorndike, A.

    1976-01-01

    The scenario is given which provides a plausible sequence of events for ISABELLE from FY 1980 to 1990. No doubt reality will be quite different. The scenario is based on the construction schedule of the 1976 proposal. Assembly and testing of the accelerator will occur until the end of FY 1983, and the next six years will provide pp interactions for the initial high energy physics research. By 1990 any temporary conditions associated with start-up of ISABELLE should be a thing of the past and all experimental capabilities fully utilized

  9. Neutron Buildup Factors Calculation for Support Vector Regression Application in Shielding Analysis

    International Nuclear Information System (INIS)

    Duckic, P.; Matijevic, M.; Grgic, D.

    2016-01-01

    In this paper initial set of data for neutron buildup factors determination using Support Vector Regression (SVR) method is prepared. The performance of SVR technique strongly depends on the quality of information used for model training. Thus it is very important to provide representable data to the SVR. SVR is a supervised type of learning so it demands data in the input/output form. In the case of neutron buildup factors estimation, the input parameters are the incident neutron energy, shielding thickness and shielding material and the output parameter is the neutron buildup factor value. So far the initial sets of data for different shielding configurations have been obtained using SCALE4.4 sequence SAS3. However, this results were obtained using group constants, thus the incident neutron energy was determined as the average value for each energy group. Obtained this way, the data provided to the SVR are fewer and therefore insufficient. More valuable information is obtained using SCALE6.2beta5 sequence MAVRIC which can perform calculations for the explicit incident neutron energy, which leads to greater maneuvering possibilities when active learning measures are employed, and consequently improves the quality of the developed SVR model.(author).

  10. Planar imaging quantification using 3D attenuation correction data and Monte Carlo simulated buildup factors

    International Nuclear Information System (INIS)

    Miller, C.; Filipow, L.; Jackson, S.; Riauka, T.

    1996-01-01

    A new method to correct for attenuation and the buildup of scatter in planar imaging quantification is presented. The method is based on the combined use of 3D density information provided by computed tomography to correct for attenuation and the application of Monte Carlo simulated buildup factors to correct for buildup in the projection pixels. CT and nuclear medicine images were obtained for a purpose-built nonhomogeneous phantom that models the human anatomy in the thoracic and abdominal regions. The CT transverse slices of the phantom were converted to a set of consecutive density maps. An algorithm was developed that projects the 3D information contained in the set of density maps to create opposing pairs of accurate 2D correction maps that were subsequently applied to planar images acquired from a dual-head gamma camera. A comparison of results obtained by the new method and the geometric mean approach based on published techniques is presented for some of the source arrangements used. Excellent results were obtained for various source - phantom configurations used to evaluate the method. Activity quantification of a line source at most locations in the nonhomogeneous phantom produced errors of less than 2%. Additionally, knowledge of the actual source depth is not required for accurate activity quantification. Quantification of volume sources placed in foam, Perspex and aluminium produced errors of less than 7% for the abdominal and thoracic configurations of the phantom. (author)

  11. Processing ultrasonic inspection data from multiple scan patterns for turbine rotor weld build-up evaluations

    Science.gov (United States)

    Guan, Xuefei; Rasselkorde, El Mahjoub; Abbasi, Waheed; Zhou, S. Kevin

    2015-03-01

    The study presents a data processing methodology for weld build-up using multiple scan patterns. To achieve an overall high probability of detection for flaws with different orientations, an inspection procedure with three different scan patterns is proposed. The three scan patterns are radial-tangential longitude wave pattern, axial-radial longitude wave pattern, and tangential shear wave pattern. Scientific fusion of the inspection data is implemented using volume reconstruction techniques. The idea is to perform spatial domain forward data mapping for all sampling points. A conservative scheme is employed to handle the case that multiple sampling points are mapped to one grid location. The scheme assigns the maximum value for the grid location to retain the largest equivalent reflector size for the location. The methodology is demonstrated and validated using a realistic ring of weld build-up. Tungsten balls and bars are embedded to the weld build-up during manufacturing process to represent natural flaws. Flat bottomed holes and side drilled holes are installed as artificial flaws. Automatic flaw identification and extraction are demonstrated. Results indicate the inspection procedure with multiple scan patterns can identify all the artificial and natural flaws.

  12. Emergency exercise scenario tools

    International Nuclear Information System (INIS)

    Sjoeblom, K.

    1998-03-01

    Nuclear power plant emergency exercises require a realistically presented accident situation which includes various aspects: plant process, radioactivity, radiation, weather and people. Experiences from nuclear power plant emergency exercises show that preparing accident scenarios even for relatively short exercises is tedious. In the future modern computer technology and past experience could be used for making exercise planning more effective. (au)

  13. Climate scenarios for California

    Science.gov (United States)

    Cayan, Daniel R.; Maurer, Ed; Dettinger, Mike; Tyree, Mary; Hayhoe, Katharine; Bonfils, Celine; Duffy, Phil; Santer, Ben

    2006-01-01

    Possible future climate changes in California are investigated from a varied set of climate change model simulations. These simulations, conducted by three state-of-the-art global climate models, provide trajectories from three greenhouse gas (GHG) emission scenarios. These scenarios and the resulting climate simulations are not “predictions,” but rather are a limited sample from among the many plausible pathways that may affect California’s climate. Future GHG concentrations are uncertain because they depend on future social, political, and technological pathways, and thus the IPCC has produced four “families” of emission scenarios. To explore some of these uncertainties, emissions scenarios A2 (a medium-high emissions) and B1 (low emissions) were selected from the current IPCC Fourth climate assessment, which provides several recent model simulations driven by A2 and B1 emissions. The global climate model simulations addressed here were from PCM1, the Parallel Climate Model from the National Center for Atmospheric Research (NCAR) and U.S. Department of Energy (DOE) group, and CM2.1 from the National Oceanic and Atmospheric Administration (NOAA) Geophysical Fluids Dynamics Laboratory (GFDL).

  14. HEALTH SCENARIO IN INDIA

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. HEALTH SCENARIO IN INDIA. Health Doctor / Hospital Infant expenditure 1000 beds / 1000 mortality / % GDP 1000. India 0.8 0.47 0.8 71. World 2.6 1.5 3.3 54. Developed 6.1 2.8 7.2 6 Countries.

  15. An economically reliable scenario

    International Nuclear Information System (INIS)

    Anon.

    1996-01-01

    Mister Benjamin Dessus, director of the Ecotech programme at the Cnrs and author of the Noe scenario, describes his propositions for energy prospective, supported by an economic analysis. He advocates the energy diversification and the use of renewable energies. (N.C.). 1 ref., 1 tab

  16. The SAFRR Tsunami Scenario

    Science.gov (United States)

    Porter, K.; Jones, Lucile M.; Ross, Stephanie L.; Borrero, J.; Bwarie, J.; Dykstra, D.; Geist, Eric L.; Johnson, L.; Kirby, Stephen H.; Long, K.; Lynett, P.; Miller, K.; Mortensen, Carl E.; Perry, S.; Plumlee, G.; Real, C.; Ritchie, L.; Scawthorn, C.; Thio, H.K.; Wein, Anne; Whitmore, P.; Wilson, R.; Wood, Nathan J.; Ostbo, Bruce I.; Oates, Don

    2013-01-01

    The U.S. Geological Survey and several partners operate a program called Science Application for Risk Reduction (SAFRR) that produces (among other things) emergency planning scenarios for natural disasters. The scenarios show how science can be used to enhance community resiliency. The SAFRR Tsunami Scenario describes potential impacts of a hypothetical, but realistic, tsunami affecting California (as well as the west coast of the United States, Alaska, and Hawaii) for the purpose of informing planning and mitigation decisions by a variety of stakeholders. The scenario begins with an Mw 9.1 earthquake off the Alaska Peninsula. With Pacific basin-wide modeling, we estimate up to 5m waves and 10 m/sec currents would strike California 5 hours later. In marinas and harbors, 13,000 small boats are damaged or sunk (1 in 3) at a cost of $350 million, causing navigation and environmental problems. Damage in the Ports of Los Angeles and Long Beach amount to $110 million, half of it water damage to vehicles and containerized cargo. Flooding of coastal communities affects 1800 city blocks, resulting in $640 million in damage. The tsunami damages 12 bridge abutments and 16 lane-miles of coastal roadway, costing $85 million to repair. Fire and business interruption losses will substantially add to direct losses. Flooding affects 170,000 residents and workers. A wide range of environmental impacts could occur. An extensive public education and outreach program is underway, as well as an evaluation of the overall effort.

  17. Prediction of moisture migration and pore pressure build-up in concrete at high temperatures

    International Nuclear Information System (INIS)

    Ichikawa, Y.; England, G.L.

    2004-01-01

    Prediction of moisture migration and pore pressure build-up in non-uniformly heated concrete is important for safe operation of concrete containment vessels in nuclear power reactors and for assessing the behaviour of fire-exposed concrete structures. (1) Changes in moisture content distribution in a concrete containment vessel during long-term operation should be investigated, since the durability and radiation shielding ability of concrete are strongly influenced by its moisture content. (2) The pressure build-up in a concrete containment vessel in a postulated accident should be evaluated in order to determine whether a venting system is necessary between liner and concrete to relieve the pore pressure. (3) When concrete is subjected to rapid heating during a fire, the concrete can suffer from spalling due to pressure build-up in the concrete pores. This paper presents a mathematical and computational model for predicting changes in temperature, moisture content and pore pressure in concrete at elevated temperatures. A pair of differential equations for one-dimensional heat and moisture transfer in concrete are derived from the conservation of energy and mass, and take into account the temperature-dependent release of gel water and chemically bound water due to dehydration. These equations are numerically solved by the finite difference method. In the numerical analysis, the pressure, density and dynamic viscosity of water in the concrete pores are calculated explicitly from a set of formulated equations. The numerical analysis results are compared with two different sets of experimental data: (a) long-term (531 days) moisture migration test under a steady-state temperature of 200 deg. C, and (b) short-term (114 min) pressure build-up test under transient heating. These experiments were performed to investigate the moisture migration and pressure build-up in the concrete wall of a reactor containment vessel at high temperatures. The former experiment simulated

  18. Layer-splitting technique for testing the recursive scheme for multilayer shields gamma ray buildup factors

    International Nuclear Information System (INIS)

    Alkhatib, Sari F.; Park, Chang Je; Jeong, Hae Yong; Lee, Yongdeok

    2016-01-01

    Highlights: • A simple formalism is suggested for the recursive approach and then it is used to produce buildup factors for certain multilayer shields. • The newly layer-splitting technique is implemented on the studied cases for testing the suggested formalism performance. • The buildup factors are generated using cubic polynomial fitting functions that are produced based on previous well-acknowledge data. - Abstract: This study illustrates the implementation of the newly suggested layer-splitting testing technique. This technique is introduced in order to be implemented in examining suggested formalisms for the recursive scheme (or iterative scheme). The recursive scheme is a concept used in treating and producing the gamma ray buildup factors in the case of multilayer shields. The layer-splitting technique simply enforces the scheme to treat a single layer of one material as two separated layers with similar characteristics. Thus it subjects the scheme to an abnormal definition of the multilayer shield that will test its performance in treating the successive layers. Thus, it will act as a method of verification for the approximations and assumptions taken in consideration. A simple formalism was suggested for the recursive scheme then the splitting technique was implemented on it. The results of implementing both the suggested formalism and the splitting technique are then illustrated and discussed. Throughout this study, cubic polynomial fitting functions were used to generate the data of buildup factors for the basic single-media that constitute the multilayer shields understudy. This study is limited to the cases of multiple shields consisting of repeated consecutive thin layers of lead–water and iron–water shields for 1 MeV gamma rays. The produced results of the buildup factor values through the implementation of the suggested formalism showed good consistency with the Monte Carlo simulation results of Lin and Jiang work. In the implementation of

  19. Variation of energy absorption buildup factors with incident photon energy and penetration depth for some commonly used solvents

    International Nuclear Information System (INIS)

    Singh, Parjit S.; Singh, Tejbir; Kaur, Paramjeet

    2008-01-01

    G.P. fitting method has been used to compute energy absorption buildup factor of some commonly used solvents such as acetonitrile (C 4 H 3 N), butanol (C 4 H 9 OH), chlorobenzene (C 6 H 5 Cl), diethyl ether (C 4 H 10 O), ethanol (C 2 H 5 OH), methanol (CH 3 OH), propanol (C 3 H 7 OH) and water (H 2 O) for the wide energy range (0.015-15.0 MeV) up to the penetration depth of 10 mean free path. The variation of energy absorption buildup factor with chemical composition as well as incident photon energy for the selected solvents has been studied. It has been observed that the maximum value of energy absorption buildup factors shifts to the slightly higher incident photon energy with the increase in equivalent atomic number of the solvent and the solvent with least equivalent atomic number possesses the maximum value of energy absorption buildup factor

  20. Document turn-over analysis to determine need of NPP construction in build-up structures of reinforced concrete

    International Nuclear Information System (INIS)

    Vojpe, D.K.; Lyubavin, V.K.

    1986-01-01

    Document turn-over to determine used of NPP construction in build-up structures of reinforced concrete is carried out. Ways of improving determination of needs of NPP construction board in the mentioned structures are pointed out

  1. Hanford groundwater scenario studies

    International Nuclear Information System (INIS)

    Arnett, R.C.; Gephart, R.E.; Deju, R.A.; Cole, C.R.; Ahlstrom, S.W.

    1977-05-01

    This report documents the results of two Hanford groundwater scenario studies. The first study examines the hydrologic impact of increased groundwater recharge resulting from agricultural development in the Cold Creek Valley located west of the Hanford Reservation. The second study involves recovering liquid radioactive waste which has leaked into the groundwater flow system from a hypothetical buried tank containing high-level radioactive waste. The predictive and control capacity of the onsite Hanford modeling technology is used to evaluate both scenarios. The results of the first study indicate that Cold Creek Valley irrigationis unlikely to cause significant changes in the water table underlying the high-level waste areas or in the movement of radionuclides already in the groundwater. The hypothetical tank leak study showed that an active response (in this case waste recovery) can be modeled and is a possible alternative to passive monitoring of radionuclide movement in the unlikely event that high-level waste is introduced into the groundwater

  2. The Scenario Planning Paradox

    DEFF Research Database (Denmark)

    Spaniol, Matthew Jon; Rowland, Nicholas James

    2017-01-01

    planning paradox. Contributing fresh theory supposedly attends to the “dismal” state of theory, while contributing new typologies purportedly helps bring order to methodological chaos. Repeated over time, the contribution strategy breaks down. Effort to resolve the theoretical and methodological issue......, foundational theoretical perspective in futures studies. Perceived chaos gives way to typologies, which, as they mount, contribute to the chaos they were meant to resolve. The end result, intended by no one, is that theory remains dismal and methods remain chaotic. This direction for the field is indefensible......For more than a decade, futures studies scholars have prefaced scholarly contributions by repeating the claim that there is insufficient theory to support chaotic scenario methodology. The strategy is formulaic, and the net effect is a curious one, which the authors refer to as the scenario...

  3. Ontario demand response scenarios

    International Nuclear Information System (INIS)

    Rowlands, I.H.

    2005-09-01

    Strategies for demand management in Ontario were examined via 2 scenarios for a commercial/institutional building with a normal summertime peak load of 300 kW between 14:00 and 18:00 during a period of high electricity demand and high electricity prices. The first scenario involved the deployment of a 150 kW on-site generator fuelled by either diesel or natural gas. The second scenario involved curtailing load by 60 kW during the same periods. Costs and benefits of both scenarios were evaluated for 3 groups: consumers, system operators and society. Benefits included electricity cost savings, deferred transmission capacity development, lower system prices for electricity, as well as environmental changes, economic development, and a greater sense of corporate social responsibility. It was noted that while significant benefits were observed for all 3 groups, they were not substantial enough to encourage action, as the savings arising from deferred generation capacity development do not accrue to individual players. The largest potential benefit was identified as lower prices, spread across all users of electricity in Ontario. It was recommended that representative bodies cooperate so that the system-wide benefits can be reaped. It was noted that if 10 municipal utilities were able to have 250 commercial or institutional customers engaged in distributed response, then a total peak demand reduction of 375 MW could be achieved, representing more than 25 per cent of Ontario's target for energy conservation. It was concluded that demand response often involves the investment of capital and new on-site procedures, which may affect reactions to various incentives. 78 refs., 10 tabs., 5 figs

  4. Demand scenarios, worldwide

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, A [Massachusetts Inst. of Technology, Center for Technology, Policy and Industrial Development and the MIT Joint Program on the Science and Policy of Global Change, Cambridge, MA (United States)

    1996-11-01

    Existing methods are inadequate for developing aggregate (regional and global) and long-term (several decades) passenger transport demand scenarios, since they are mainly based on simple extensions of current patterns rather than causal relationships that account for the competition among transport modes (aircraft, automobiles, buses and trains) to provide transport services. The demand scenario presented in this paper is based on two empirically proven invariances of human behavior. First, transport accounts for 10 to 15 percent of household total expenditures for those owning an automobile, and around 5 percent for non-motorized households on average (travel money budget). Second, the mean time spent traveling is approximately one hour per capita per day (travel time budget). These two budgets constraints determine the dynamics of the scenario: rising income increases per capita expenditure on travel which, in turn, increase demand for mobility. Limited travel time constraints travelers to shift to faster transport systems. The scenario is initiated with the first integrated historical data set on traffic volume in 11 world regions and the globe from 1960 to 1990 for all major modes of motorized transport. World average per capita traffic volume, which was 1,800 kilometers in 1960 and 4,2090 in 1990, is estimated to rise to 7,900 kilometers in 2020 - given a modest average increase in Gross World Product of 1.9% per year. Higher economic growth rates in Asian regions result in an increase in regional per capita traffic volume up to a factor of 5.3 from 1990 levels. Modal splits continue shifting to more flexible and faster modes of transport. At one point, passenger cars can no longer satisfy the increasing demand for speed (i.e. rising mobility within a fixed time budget). In North America it is estimated that the absolute traffic volume of automobiles will gradually decline starting in the 2010s. (author) 13 figs., 6 tabs., 35 refs.

  5. Investigation of the different scenarios occurring in a PWR in case of a TMLB accident

    International Nuclear Information System (INIS)

    Pochard, R.; Dufresne, J.; Autrusson, B.

    1988-10-01

    Severe accidents in light water reactors fall into one of two main categories, depending on whether or not core meltdown is accompanied by a pressure buildup in the primary system. The way in which the accident develops is, in fact, largely conditioned by this pressure aspect: temperature distribution in the core and primary system resulting from natural convection gas streams; fuel clad failure mode, etc... One major effect of pressure buildup on the accident scenario is primary system failure under the combined actions of pressure and temperature. The purpose of the present paper is to present, after a detailed thermalhydraulic study, an analysis of the timing and location of the system failures in case of a TMLB accident on CPY french type reactor

  6. Lepton contamination and photon scatter produced by open field 18 MV X-ray beams in the build-up region

    International Nuclear Information System (INIS)

    Butson, M.J.; Cheung Tsang; Yu, P.K.N.

    2002-01-01

    18 MV X-ray beams used in radiotherapy have skin sparing properties as they produce a dose build-up effect whereby a smaller dose is delivered to the skin compared to dose at depth. Experimental results have shown that variations in the build-up dose significantly contribute to lepton contamination produced outside of the patient or the phantom in question. Monte Carlo simulations of 18 MV X-ray beams show that the surface dose contribution from in-phantom scatter alone is approximately 6% of the maximum dose. The contribution to dose from lepton contamination is found by comparison of Monte Carlo phantom photon scatter dose only and experimental data. Results show that the percentage contributions to dose from lepton contamination are approximately, 65%, 90% of dose at 0.05 mm (basal cell layer), 52%, 79% at 1 mm depth (dermal layer) and 15%, 26% at 10 mm depth (subcutaneous tissue) for 10 cmx10 cm 2 and 40 cmx40 cm 2 fields, respectively

  7. Lepton contamination and photon scatter produced by open field 18 MV X-ray beams in the build-up region

    Energy Technology Data Exchange (ETDEWEB)

    Butson, M.J. E-mail: mbutson@guessmail.com; Cheung Tsang; Yu, P.K.N

    2002-04-01

    18 MV X-ray beams used in radiotherapy have skin sparing properties as they produce a dose build-up effect whereby a smaller dose is delivered to the skin compared to dose at depth. Experimental results have shown that variations in the build-up dose significantly contribute to lepton contamination produced outside of the patient or the phantom in question. Monte Carlo simulations of 18 MV X-ray beams show that the surface dose contribution from in-phantom scatter alone is approximately 6% of the maximum dose. The contribution to dose from lepton contamination is found by comparison of Monte Carlo phantom photon scatter dose only and experimental data. Results show that the percentage contributions to dose from lepton contamination are approximately, 65%, 90% of dose at 0.05 mm (basal cell layer), 52%, 79% at 1 mm depth (dermal layer) and 15%, 26% at 10 mm depth (subcutaneous tissue) for 10 cmx10 cm{sup 2} and 40 cmx40 cm{sup 2} fields, respectively.

  8. Pressurization Risk Assessment of CO2 Reservoirs Utilizing Design of Experiments and Response Surface Methods

    Science.gov (United States)

    Guyant, E.; Han, W. S.; Kim, K. Y.; Park, E.; Han, K.

    2015-12-01

    Monitoring of pressure buildup can provide explicit information on reservoir integrity and is an appealing tool, however pressure variation is dependent on a variety of factors causing high uncertainty in pressure predictions. This work evaluated pressurization of a reservoir system in the presence of leakage pathways as well as exploring the effects of compartmentalization of the reservoir utilizing design of experiments (Definitive Screening, Box Behnken, Central Composite, and Latin Hypercube designs) and response surface methods. Two models were developed, 1) an idealized injection scenario in order to evaluate the performance of multiple designs, and 2) a complex injection scenario implementing the best performing design to investigate pressurization of the reservoir system. A holistic evaluation of scenario 1, determined that the Central Composite design would be used for the complex injection scenario. The complex scenario evaluated 5 risk factors: reservoir, seal, leakage pathway and fault permeabilities, and horizontal position of the pathway. A total of 60 response surface models (RSM) were developed for the complex scenario with an average R2 of 0.95 and a NRMSE of 0.067. Sensitivity to the input factors was dynamic through space and time; at the earliest time (0.05 years) the reservoir permeability was dominant, and for later times (>0.5 years) the fault permeability became dominant for all locations. The RSM's were then used to conduct a Monte Carlo Analysis to further analyze pressurization risks, identifying the P10, P50, P90 values. This identified the in zone (lower) P90 values as 2.16, 1.77, and 1.53 MPa and above zone values of 1.35, 1.23, 1.09 MPa for monitoring locations 1, 2, and 3, respectively. In summary, the design of experiments and response surface methods allowed for an efficient sensitivity and uncertainty analysis to be conducted permitting a complete evaluation of the pressurization across the entire parameter space.

  9. Fusion-product ash buildup in tokamak with radial electric field

    International Nuclear Information System (INIS)

    Downum, W.B.; Choi, C.K.; Miley, G.H.

    1979-01-01

    The buildup of thermalized fusion products (ash) in a tokamak can seriously limit burn times. Prior studies have concentrated on deposition profile effects on alpha particle transport in tokamaks but have not considered the effect on ash of radial electric fields (either created internally, e.g. due to high-energy alpha leakage, or generated externally). The present study focuses on this issue since it appears that electric fields might offer one approach to control of the ash. Approximate field and source profiles are used, based on prior calculations

  10. Optimal Pile Arrangement for Minimizing Excess Pore Water Pressure Build-Up

    DEFF Research Database (Denmark)

    Barari, Amin; Saadati, Meysam; Ibsen, Lars Bo

    2013-01-01

    Numerical analysis of pile group in a liquefiable soil was considered to investigate the influence of pile spacing on excess pore pressure distribution and liquefaction potential. The analysis is conducted using a two-dimensional plain strain finite difference program considering a nonlinear...... constitutive model for sandy soil, strength and stiffness reduction, and pile-soil interaction. The Mohr-Coulomb constitutive model coupled with Byrne pore pressure build-up model have been employed in the analysis. Numerical analysis results show that pile groups have significant influence on the dynamic...... response of sandy soil as they reduce the amount of excess pore pressure development during seismic shaking and may even prevent liquefaction....

  11. The application of the LTSN method in the evaluation of the buildup factor

    International Nuclear Information System (INIS)

    Rodriguez, Barbara A.; Borges, Volnei; Zabadal, Jorge R.

    2005-01-01

    In this paper the LTS N method is used to solve the transport equation for photons in a heterogeneous medium, assuming the Klein-Nishina scattering kernel as the scattering differential cross section as well the multigroup model in the wavelength variable. The flux density of photons and the parameters of the medium are used for the calculation of the exposure buildup factor. We present numerical simulations and comparisons with available results in the literature for different compositions containing water, iron and lead. (author)

  12. Scenarios for the future

    International Nuclear Information System (INIS)

    Haegermark, H.; Bergmark, M.

    1995-06-01

    This project aims primarily to give a basis for the joint R and D program for the Swedish electric utility industry, in the form of pictures of the future up to 2020. The work was performed during four seminars in a group of managers and R and D planners. The four scenarios differ mainly in the assumptions of high or low economic growth and on market or political rule. Assumptions on essential uncertainties about the future have been combined in a consistent manner, e.g. on the structure of the utility industry, the role of nuclear power, the importance of the greenhouse gas issue, the influence of new technology developments and on changes of values in society. Certain other development appear in all scenarios, e.g. the impact of information technology throughout society, the internationalization of business in general and industrial production in particular, considerations for the environment and care for natural resources. The four scenarios are: 'Technology on the throne' (market rule/high growth); 'Intense competition' (market rule/low growth); 'Monopoly takes over' (political rule/high growth); and 'Green local society' (political rule/low growth). Some of the important factors pointed out by the study are: Increased customer mobility between regions and countries; The impact of information technology; Societal value changes; Sustainable development as an important driving force; Structure of the utility industry. Diversifying into new services. New players; Access to knowledge and competence; Ways for handling the greenhouse gas problem; Preparedness for nuclear power phase-out. 12 figs, 6 tabs

  13. Crisis and Crisis Scenarios

    DEFF Research Database (Denmark)

    Larsen, Øjvind

    2016-01-01

    This special issue of Nordicum-Mediterraneum contains select proceedings from the third meeting of the Nordic Summer University research circle called “Crisis and Crisis Scenarios: Normativity, Possibilities and Dilemmas”, held April 9th — 12th, 2015 at the Lysebu Conference Centre in Oslo, Norway....... The circle’s research program runs from 2014 to 2016 and is aimed at examining the concept of crisis as it is used today in academia and public discussion. In this collection of papers from the symposium we present some of the different ways in which the topic of the study group was addressed....

  14. Making use of scenarios : supporting scenario use in product design

    NARCIS (Netherlands)

    Anggreeni, Irene

    2010-01-01

    The discipline of Scenario-Based Product Design (SBPD) guides the use of scenarios in a product design process. As concrete narratives, scenarios could facilitate making explicit how users would use the designed product in their activities, allowing usability studies to be an integrated part of the

  15. ILC Operating Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Barklow, T.; Brau, J.; Fujii, K.; Gao, J.; List, J.; Walker, N.; Yokoya, K.; Collaboration: ILC Parameters Joint Working Group

    2015-06-15

    The ILC Technical Design Report documents the design for the construction of a linear collider which can be operated at energies up to 500 GeV. This report summarizes the outcome of a study of possible running scenarios, including a realistic estimate of the real time accumulation of integrated luminosity based on ramp-up and upgrade processes. The evolution of the physics outcomes is emphasized, including running initially at 500 GeV, then at 350 GeV and 250 GeV. The running scenarios have been chosen to optimize the Higgs precision measurements and top physics while searching for evidence for signals beyond the standard model, including dark matter. In addition to the certain precision physics on the Higgs and top that is the main focus of this study, there are scientific motivations that indicate the possibility for discoveries of new particles in the upcoming operations of the LHC or the early operation of the ILC. Follow-up studies of such discoveries could alter the plan for the centre-of-mass collision energy of the ILC and expand the scientific impact of the ILC physics program. It is envisioned that a decision on a possible energy upgrade would be taken near the end of the twenty year period considered in this report.

  16. Radiation Build-Up Of High Energy Gamma In Shielding Of High Atomic Number

    International Nuclear Information System (INIS)

    Yuliati, Helfi; Akhadi, Mukhlis

    2000-01-01

    Research to observe effect of radiation build-up factor (b) in iron (Fe) and lead (Pb) for high energy gamma shielding from exp.137 Cs (E gamma : 662 keV) and exp.60 Co (E gamma : 1332 keV) sources has been carried out. Research was conducted bt counting of radiation intensity behind shielding with its thickness vary from 1 to 5 times of half value thickness (HVT). NaI (TI) detector which connected to multi channel analyzer (MCA) was used for the counting. Calculation result show that all of b value are near to 1 (b∼1) both for Fe and Pb. Without inserting b in calculation, from the experiment it was obtained HVT value of Fe for high gamma radiation of 662 and 1332 keV were : (12,94 n 0,03) mm and (17,33 n 0,01) mm with their deviation standards were 0,2% and 0,06% respectively. Value of HVT for Pb with the same energy were : (6,31 n 0,03) mm and (11,86 n 0,03) mm with their deviation standars were : 0,48% and 0,25% respectively. HVL concept could be applied directly to estimate shielding thickness of high atomic number of high energy gamma radiation, without inserting correction of radiation build-up factor

  17. Radiation Build-Up In Shielding Of Low Activity High Energia Gamma Source

    International Nuclear Information System (INIS)

    Helfi-Yuliati; Mukhlis-Akhadi

    2003-01-01

    Research to observe radiation build-up factor (b) in aluminium (Al), iron (Fe) and lead (Pb) for shielding of gamma radiation of high energy from 137 cs (E γ : 662 keV) source and 60 Co (E γ : 1332 keV) of low activity sources has been carried out. Al with Z =13 represent metal of low atomic number, Fe with Z =26 represent metal of medium atomic number, and Pb with Z = 82 represent metal of high atomic number. Low activity source in this research is source which if its dose rate decrease to 3 % of its initial dose rate became safe for the workers. Research was conducted by counting of radiation intensity behind shielding with its thickness vary from 1 to 5 times of half value thickness (HVT). NaI(TI) detector which connected to multi channel analyzer (MCA) was used for the counting. Calculation result show that all of b value are close to 1 (b ∼ 1) for all kinds of metals. No radiation build-up factor is required in estimating the shielding thickness from several kinds of metals for low activity of high energy gamma source. (author)

  18. Buildup factors for multilayer shieldings in deterministic methods and their comparison with Monte Carlo

    International Nuclear Information System (INIS)

    Listjak, M.; Slavik, O.; Kubovcova, D.; Vermeersch, F.

    2008-01-01

    In general there are two ways how to calculate effective doses. The first way is by use of deterministic methods like point kernel method which is implemented in Visiplan or Microshield. These kind of calculations are very fast, but they are not very convenient for a complex geometry with shielding composed of more then one material in meaning of result precision. In spite of this that programs are sufficient for ALARA optimisation calculations. On other side there are Monte Carlo methods which can be used for calculations. This way of calculation is quite precise in comparison with reality but calculation time is usually very large. Deterministic method like programs have one disadvantage -usually there is option to choose buildup factor (BUF) only for one material in multilayer stratified slabs shielding calculation problems even if shielding is composed from different materials. In literature there are proposed different formulas for multilayer BUF approximation. Aim of this paper was to examine these different formulas and their comparison with MCNP calculations. At first ware compared results of Visiplan and Microshield. Simple geometry was modelled - point source behind single and double slab shielding. For Build-up calculations was chosen Geometric Progression method (feature of the newest version of Visiplan) because there are lower deviations in comparison with Taylor fitting. (authors)

  19. The future role of reforestation in reducing buildup of atmospheric CO2

    International Nuclear Information System (INIS)

    Marland, G.

    1993-01-01

    Among the options posed for mitigating the buildup of atmospheric CO 2 is planting new forest areas to sequester carbon from the atmosphere. Among the questions of interest in modeling the global carbon cycle is the extent to which reforestation is likely to succeed in providing physical removal of CO 2 from the atmosphere. There are many strategies for using forest land to mitigate the atmospheric buildup of CO 2 : decreasing the rate at which forests are cleared for other land uses, increasing the density of carbon storage in existing forests, improving the rate and efficiency at which forest products are used in the place of other energy intensive products, substitution of renewable wood fuels for fossil fuels, improved management of forests and agroforestry, and increasing the amount of land in standing forest. Because increasing the area of forests has social, political, and economic limitations; in addition to physical limitations; it is hard to envision a large increase in forest area except where there are associated economic benefits. The authors speculation is that, over the next several decades, the forest strategies most likely to be pursued for the express purpose of CO 2 mitigation are those which provide more or more-efficient substitution of forest products for energy or energy-intensive resources and that the physical accumulation of additional carbon in forests will be of lesser importance

  20. French experience to reduce radiation field build-up and improve nuclear fuel performance

    International Nuclear Information System (INIS)

    Thomazet, J.; Beslu, P.; Noe, M.; Stora, J.P.

    1983-01-01

    Over these last years, considerable information has been obtained on primary coolant chemistry, activity build-up and nuclear fuel behavior. As of December 1982, twenty three 900 MWe type reactors were in operation in France and about 1.3 millions of rods had been loaded in power reactors among which six regions of 17x17 fuel assemblies had completed successfully their third cycle of irradiation with a lead assembly burn-up of 37,000 MWd/MtU. Visual examination shows that crud deposited on fuel clads is mostly thin or inexistent. This result is due to the appropriate B/Li coolant concentration control which is currently applied in French reactors since several years. Correlatively, radiation field build-up is minimized and excessive external corrosion has never been observed. Nevertheless for higher coolant temperature plants, where occurrence of nucleate boiling could increase crud deposition, and for load follow and high burn-up operation, an extensive programme is performed jointly by Commissariat a l'Energie Atomique (CEA), Electricite de France, FRAMATOME and FRAGEMA to reduce even more the radiation field. This programme, described in the paper, includes: loop tests; on site chemical and radiochemical surveys; radiation field measurements; on site fuel examination crud-scrapping, crud analysis and oxide thickness measurements; hot cells examination. Some key results are presented and discussed in this paper. (author)

  1. Quantitative assessment of the effect of corrosion product buildup on occupational exposure

    International Nuclear Information System (INIS)

    Divine, J.R.

    1982-10-01

    The program was developed to provide a method for predicting occupational exposures caused by the deposition of radioactive corrosion products outside the core of the primary system of an operating power reactor. This predictive capability will be useful in forecasting total occupational doses during maintenance, inspection, decontamination, waste treatment, and disposal. In developing a reliable predictive model, a better understanding of the parameters important to corrosion product film formation, corrosion product transport, and corrosion product film removal will be developed. This understanding can lead to new concepts in reactor design to minimize the buildup and transport of radioactive corrosion products or to improve methods of operation. To achieve this goal, three objectives were established to provide: (1) criteria for acceptable coolant sampling procedures and sampling equipment that will provide data which will be used in the model development; (2) a quantitative assessment of the effect of corrosion product deposits on occupational exposure; and (3) a model which describes the influence of flow, temperature, coolant chemistry, construction materials, radiation, and other operating parameters on the transport and buildup of corrosion products

  2. Electron Cloud Buildup Characterization Using Shielded Pickup Measurements and Custom Modeling Code at CESRTA

    CERN Document Server

    Crittenden, James A

    2013-01-01

    The Cornell Electron Storage Ring Test Accelerator experimental program includes investigations into electron cloud buildup, applying various mitigation techniques in custom vacuum chambers. Among these are two 1.1-m-long sections located symmetrically in the east and west arc regions. These chambers are equipped with pickup detectors shielded against the direct beam-induced signal. They detect cloud electrons migrating through an 18-mm-diameter pattern of small holes in the top of the chamber. A digitizing oscilloscope is used to record the signals, providing time-resolved information on cloud development. Carbon-coated, TiN-coated and uncoated aluminum chambers have been tested. Electron and positron beams of 2.1, 4.0 and 5.3 GeV with a variety of bunch populations and spacings in steps of 4 and 14 ns have been used. Here we report on results from the ECLOUD modeling code which highlight the sensitivity of these measurements to the physical phenomena determining cloud buildup such as the photoelectron produ...

  3. The evaluation of nylon and polyethylene as build-up material in a neutron therapy beam

    International Nuclear Information System (INIS)

    Hough, J.H.; Binns, P.J.

    1995-01-01

    In high-energy neutron beams a substantial amount of build-up material is required to irradiate biological samples under conditions of charged particle equilibrium. Ideally A-150 tissue-equivalent plastic is used for this purpose. This material is however not always readily available and hence the need for a substitute compound. The selected hydrocarbon should satisfy two requirements: the quality of the radiation on the distal side needs to be the same as that measured for A-150 plastic and the absorbed dose should remain consistent. A tissue-equivalent proportional counter operating at reduced pressure not only measures the absorbed dose accurately but provides a means for assessing the nature of a radiation field in terms of a secondary charged particle spectrum. Using build-up caps manufactured from nylon (type 6) and polyethylene, it is shown that the former is an acceptable substitute for A-150 plastic. The data further demonstrate that both the absorbed dose and the spectral character of the measured single-event distribution are altered when polyethylene is used and that these discrepancies are attributable to the higher hydrogen content of polyethylene. (Author)

  4. Buildup factors for multilayer shieldings in deterministic methods and their comparison with Monte Carlo

    International Nuclear Information System (INIS)

    Listjak, M.; Slavik, O.; Kubovcova, D.; Vermeersch, F.

    2009-01-01

    In general there are two ways how to calculate effective doses. The first way is by use of deterministic methods like point kernel method which is implemented in Visiplan or Microshield. These kind of calculations are very fast, but they are not very convenient for a complex geometry with shielding composed of more then one material in meaning of result precision. In spite of this that programs are sufficient for ALARA optimisation calculations. On other side there are Monte Carlo methods which can be used for calculations. This way of calculation is quite precise in comparison with reality but calculation time is usually very large. Deterministic method like programs have one disadvantage -usually there is option to choose buildup factor (BUF) only for one material in multilayer stratified slabs shielding calculation problems even if shielding is composed from different materials. In literature there are proposed different formulas for multilayer BUF approximation. Aim of this paper was to examine these different formulas and their comparison with MCNP calculations. At first ware compared results of Visiplan and Microshield. Simple geometry was modelled - point source behind single and double slab shielding. For Build-up calculations was chosen Geometric Progression method (feature of the newest version of Visiplan) because there are lower deviations in comparison with Taylor fitting. (authors)

  5. 40 Years of Shell Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-02-15

    Shell has been using scenario planning for four decades. During that time these scenarios have helped the company and governments across the world to make better strategic choices. Scenarios provide lenses that help see future prospects more clearly, make richer judgments and be more sensitive to uncertainties. Discover how the Shell Scenarios team has helped guide decision makers at major moments in history and get a peek at the team future focus, including the intricate relationship between energy, water and food.

  6. The IIASA'83 scenario of energy development

    International Nuclear Information System (INIS)

    Rogner, H.H.

    1984-01-01

    The prospects for natural gas as a major source of energy supply are good. Spurred by the energy crises of the 'seventies, recent exploration for gas resources as well as technological advances in deep drilling have enhanced the picture of gas as a plentiful fossil resource. Technological improvements in transporting gas over large distances, as piped gas and as a liquid, suggest the strong possibility of gas as an important commodity in energy trade. In addition, gas is a high quality and relatively clean fuel, which is especially attractive in today's world of environmental concern for pollution emissions from energy combustion. Such developments led to the design of the IIASA'83 Scenario of Energy Development, which explored the techno-economic feasibility of the expanded use of gas in energy systems. The work drew on the findings of the IIASA global energy analysis, documented in 'Energy in a Finite World'. All countries of the world were covered in the quantitative analysis, grouped regionally by similarity in energy resources and economic structure and not necessarily on the basis of geographic proximity. The period studied was necessarily the next half century, from 1980 to 2030, in view of the inertia in technological and economic systems and this constraint on the development of energy infrastructures. Global primary energy consumption increases some twofold from 10 TW.a/a to 21.9 TW.a/a over the next 50 years, while economic output globally grows some threefold. The breakdown of global primary energy consumption indicates an absolute increase in the use of all primary energy sources over the study period, with fossil fuels continuing to supply the lion's share of primary energy. The buildup of non-fossil energy sources to global supply levels by 2030 is likely to be constrained by the high capital investments required at a period of modest economic growth and by the sociopolitical controversy surrounding the use of some of these technologies. (author)

  7. Engaging Personas and Narrative Scenarios

    DEFF Research Database (Denmark)

    Nielsen, Lene

    2004-01-01

    design ideas. The concept of engaging personas and narrative scenario explores personas in the light of what what it is to identify with and have empathy with a character. The concept of narrative scenarios views the narrative as aid for exploration of design ideas. Both concepts incorporate...... a distinktion between creating, writing and reading. Keywords: personas, scenarios, user-centered design, HCI...

  8. Biomass Scenario Model Scenario Library: Definitions, Construction, and Description

    Energy Technology Data Exchange (ETDEWEB)

    Inman, D.; Vimmerstedt, L.; Bush, B.; Peterson, S.

    2014-04-01

    Understanding the development of the biofuels industry in the United States is important to policymakers and industry. The Biomass Scenario Model (BSM) is a system dynamics model of the biomass-to-biofuels system that can be used to explore policy effects on biofuels development. Because of the complexity of the model, as well as the wide range of possible future conditions that affect biofuels industry development, we have not developed a single reference case but instead developed a set of specific scenarios that provide various contexts for our analyses. The purpose of this report is to describe the scenarios that comprise the BSM scenario library. At present, we have the following policy-focused scenarios in our library: minimal policies, ethanol-focused policies, equal access to policies, output-focused policies, technological diversity focused, and the point-of-production- focused. This report describes each scenario, its policy settings, and general insights gained through use of the scenarios in analytic studies.

  9. Support vector regression model for the estimation of γ-ray buildup factors for multi-layer shields

    International Nuclear Information System (INIS)

    Trontl, Kresimir; Smuc, Tomislav; Pevec, Dubravko

    2007-01-01

    The accuracy of the point-kernel method, which is a widely used practical tool for γ-ray shielding calculations, strongly depends on the quality and accuracy of buildup factors used in the calculations. Although, buildup factors for single-layer shields comprised of a single material are well known, calculation of buildup factors for stratified shields, each layer comprised of different material or a combination of materials, represent a complex physical problem. Recently, a new compact mathematical model for multi-layer shield buildup factor representation has been suggested for embedding into point-kernel codes thus replacing traditionally generated complex mathematical expressions. The new regression model is based on support vector machines learning technique, which is an extension of Statistical Learning Theory. The paper gives complete description of the novel methodology with results pertaining to realistic engineering multi-layer shielding geometries. The results based on support vector regression machine learning confirm that this approach provides a framework for general, accurate and computationally acceptable multi-layer buildup factor model

  10. Scenario development methodologies

    International Nuclear Information System (INIS)

    Eng, T.; Hudson, J.; Stephansson, O.

    1994-11-01

    In the period 1981-1994, SKB has studied several methodologies to systematize and visualize all the features, events and processes (FEPs) that can influence a repository for radioactive waste in the future. All the work performed is based on the terminology and basic findings in the joint SKI/SKB work on scenario development presented in the SKB Technical Report 89-35. The methodologies studied are a) Event tree analysis, b) Influence diagrams and c) Rock Engineering Systems (RES) matrices. Each one of the methodologies is explained in this report as well as examples of applications. One chapter is devoted to a comparison between the two most promising methodologies, namely: Influence diagrams and the RES methodology. In conclusion a combination of parts of the Influence diagram and the RES methodology is likely to be a promising approach. 26 refs

  11. Calculation of gamma ray dose buildup factors in water for isotropic point, plane mono directional and line sources using MCNP code

    International Nuclear Information System (INIS)

    Atak, H.; Celikten, O. S.; Tombakoglu, M.

    2009-01-01

    Gamma ray dose buildup factors in water for isotropic point, plane mono directional and infinite/finite line sources were calculated using the MCNP code. The buildup factors are determined for gamma ray energies of 1, 2, 3 and 4 Mev and for shield thicknesses of 1, 2, 4 and 7 mean free paths. The calculated buildup factors were then fitted in the Taylor and Berger forms. For the line sources a buildup factor table was also constructed using the Sievert function and the constants in Taylor form derived in this study to compare with the Monte Carlo results. All buildup factors were compared with the tabulated data given in literature. In order to reduce the statistical errors on buildup factors, 'forced collision' option was used in the MCNP calculations.

  12. The Build-Up to Eruptive Solar Events Viewed as the Development of Chiral Systems

    Science.gov (United States)

    Martin, S. F.; Panasenco, O.; Berger, M. A.; Engvold, O.; Lin, Y.; Pevtsov, A. A.; Srivastava, N.

    2012-12-01

    When we examine the chirality or observed handedness of the chromospheric and coronal structures involved in the long-term build-up to eruptive events, we find that they evolve in very specific ways to form two and only two sets of large-scale chiral systems. Each system contains spatially separated components with both signs of chirality, the upper portion having negative (positive) chirality and the lower part possessing positive (negative) chirality. The components within a system are a filament channel (represented partially by sets of chromospheric fibrils), a filament (if present), a filament cavity, sometimes a sigmoid, and always an overlying arcade of coronal loops. When we view these components as parts of large-scale chiral systems, we more clearly see that it is not the individual components of chiral systems that erupt but rather it is the approximate upper parts of an entire evolving chiral system that erupts. We illustrate the typical pattern of build-up to eruptive solar events first without and then including the chirality in each stage of the build-up. We argue that a complete chiral system has one sign of handedness above the filament spine and the opposite handedness in the barbs and filament channel below the filament spine. If the spine has handedness, the observations favor its having the handedness of the filament cavity and coronal loops above. As the separate components of a chiral system form, we show that the system appears to maintain a balance of right-handed and left-handed features, thus preserving an initial near-zero net helicity. We further argue that the chiral systems allow us to identify key sites of energy transformation and stored energy later dissipated in the form of concurrent CMEs, erupting filaments and solar flares. Each individual chiral system may produce many successive eruptive events above a single filament channel. Because major eruptive events apparently do not occur independent of, or outside of, these unique

  13. Scenario planning and nanotechnological futures

    International Nuclear Information System (INIS)

    Farber, Darryl; Lakhtakia, Akhlesh

    2009-01-01

    Scenario planning may assist us in harnessing the benefits of nanotechnology and managing the associated risks for the good of the society. Scenario planning is a way to describe the present state of the world and develop several hypotheses about the future of the world, thereby enabling discussions about how the world ought to be. Scenario planning thus is not only a tool for learning and foresight, but also for leadership. Informed decision making by experts and political leaders becomes possible, while simultaneously allaying the public's perception of the risks of new and emerging technologies such as nanotechnology. Two scenarios of the societal impact of nanotechnology are the mixed-signals scenario and the confluence scenario. Technoscientists have major roles to play in both scenarios.

  14. Strategic Scenario Construction Made Easy

    DEFF Research Database (Denmark)

    Duus, Henrik Johannsen

    2016-01-01

    insights from the area of strategic forecasting (of which scenario planning is a proper subset) and experiences gained from a recent course in that area to develop a simpler, more direct, hands-on method for scenario construction and to provide several ideas for scenario construction that can be used......Scenario planning is a well-known way to develop corporate strategy by creating multiple images of alternative futures. Yet although scenario planning grew from very hands-on strategy development efforts in the military and from operations research dedicated to solving practical problems, the use...... of scenarios in business has, in many cases, remained a cumbersome affair. Very often a large group of consultants, employees and staff is involved in the development of scenarios and strategies, thus making the whole process expensive in terms of time, money and human resources. In response, this article uses...

  15. Build-up Factor Calculation for Ordinary Concrete, Baryte Concrete and Blast-furnace Slugges Concrete as γ Radiation Shielding

    International Nuclear Information System (INIS)

    Isman MT; Elisabeth Supriatni; Tochrul Binowo

    2002-01-01

    Calculation of build up factor ordinary concrete, baryte concrete and blast-furnace sludge concrete have been carried out. The calculations have been carried out by dose rate measurement of Cs 137 source before and after passing through shielding. The investigated variables were concrete type, thickness of concrete and relative possession of concrete. Concrete type variables are ordinary concrete, baryte concrete and blast sludge furnace concrete. The thickness variables were 6, 12, 18, 24, 30 and 36 cm. The relative position variables were dose to the source and close to detector. The result showed that concrete type and position did not have significant effect to build-up factor value, while the concrete thickness (r) and the attenuation coefficient (μ) were influenced to the build-up factor. The higher μr value the higher build-up factor value. (author)

  16. Urban nonpoint source pollution buildup and washoff models for simulating storm runoff quality in the Los Angeles County.

    Science.gov (United States)

    Wang, Long; Wei, Jiahua; Huang, Yuefei; Wang, Guangqian; Maqsood, Imran

    2011-07-01

    Many urban nonpoint source pollution models utilize pollutant buildup and washoff functions to simulate storm runoff quality of urban catchments. In this paper, two urban pollutant washoff load models are derived using pollutant buildup and washoff functions. The first model assumes that there is no residual pollutant after a storm event while the second one assumes that there is always residual pollutant after each storm event. The developed models are calibrated and verified with observed data from an urban catchment in the Los Angeles County. The application results show that the developed model with consideration of residual pollutant is more capable of simulating nonpoint source pollution from urban storm runoff than that without consideration of residual pollutant. For the study area, residual pollutant should be considered in pollutant buildup and washoff functions for simulating urban nonpoint source pollution when the total runoff volume is less than 30 mm. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Buildup factor and mechanical properties of high-density cement mixed with crumb rubber and prompt gamma ray study

    Science.gov (United States)

    Aim-O, P.; Wongsawaeng, D.; Tancharakorn, S.; Sophon, M.

    2017-09-01

    High-density cement mixed with crumb rubber has been studied to be a gamma ray and neutron shielding material, especially for photonuclear reactions that may occur from accelerators where both types of radiation exist. The Buildup factors from gamma ray scattering, prompt and secondary gamma ray emissions from neutron capture and mechanical properties were evaluated. For buildup factor studies, two different geometries were used: narrow beam and broad beam. Prompt Gamma Neutron Activation Analysis (PGNAA) was carried out to determine the prompt and secondary gamma ray emissions. The compressive strength of samples was evaluated by using compression testing machine which was central point loading crushing test. The results revealed that addition of crumb rubber increased the buildup factor. Gamma ray spectra following PGNAA revealed no prompt or secondary gamma ray emission. Mechanical testing indicated that the compressive strength of the shielding material decreased with increasing volume percentage of crumb rubber.

  18. Energy absorption buildup factors of human organs and tissues at energies and penetration depths relevant for radiotherapy and diagnostics

    DEFF Research Database (Denmark)

    Manohara, S. R.; Hanagodimath, S. M.; Gerward, Leif

    2011-01-01

    Energy absorption geometric progression (GP) fitting parameters and the corresponding buildup factors have been computed for human organs and tissues, such as adipose tissue, blood (whole), cortical bone, brain (grey/white matter), breast tissue, eye lens, lung tissue, skeletal muscle, ovary......, testis, soft tissue, and soft tissue (4-component), for the photon energy range 0.015-15 MeV and for penetration depths up to 40 mfp (mean free path). The chemical composition of human organs and tissues is seen to influence the energy absorption buildup factors. It is also found that the buildup factor...... of human organs and tissues changes significantly with the change of incident photon energy and effective atomic number, Zeff. These changes are due to the dominance of different photon interaction processes in different energy regions and different chemical compositions of human organs and tissues...

  19. Aesthetic Closure of Maxillary and Mandibular Anterior Spaces Using Direct Composite Resin Build-Ups: A Case Report

    Directory of Open Access Journals (Sweden)

    Schick Simona-Georgiana

    2016-07-01

    Full Text Available The presence of multiple spaces in the anterior aesthetic zone can produce discomfort for patients and its treatment can be difficult for dental professionals. A variety of treatment options are available and these include orthodontic movement, prosthetic indirect restorations or direct composite resin build-ups. Among these, the closure of interdental spaces using composite build-ups combined with orthodontic treatment is considered to be most conservative. This type of treatment has several advantages like the maximum preservation of tooth substance (no tooth preparation, no need for anesthesia, no multiple time-consuming visits, no provisional restorations and also comparably low costs. Clinical Consideration: This case report describes the clinical restorative procedure of direct composite resin build-ups for the closure of multiple anterior spaces.

  20. The effect of plasma minor-radius expansion in the current build-up phase of a large tokamak

    International Nuclear Information System (INIS)

    Kobayashi, Tomofumi; Tazima, Teruhiko; Tani, Keiji; Tamura, Sanae

    1977-03-01

    A plasma simulation code has been developed to study the plasma current build-up process in JT-60. Plasma simulation is made with a model which represents well overall plasma behavior of the present-day tokamaks. The external electric circuit is taken into consideration in simulation calculation. An emphasis is placed on the simulation of minor-radius expansion of the plasma and behavior of neutral particles in the plasma during current build-up. A calculation with typical parameters of JT-60 shows a week skin distribution in the current density and the electron temperature, if the minor radius of the plasma expands with build-up of the plasma current. (auth.)

  1. The influence of modified water chemistries on metal oxide films, activity build-up and stress corrosion cracking of structural materials in nuclear power plants

    International Nuclear Information System (INIS)

    Maekelae, K.; Laitinen, T.; Bojinov, M.

    1999-03-01

    The primary coolant oxidises the surfaces of construction materials in nuclear power plants. The properties of the oxide films influence significantly the extent of incorporation of actuated corrosion products into the primary circuit surfaces, which may cause additional occupational doses for the maintenance personnel. The physical and chemical properties of the oxide films play also an important role in different forms of corrosion observed in power plants. This report gives a short overview of the factors influencing activity build-up and corrosion phenomena in nuclear power plants. Furthermore, the most recent modifications in the water chemistry to decrease these risks are discussed. A special focus is put on zinc water chemistry, and a preliminary discussion on the mechanism via which zinc influences activity build-up is presented. Even though the exact mechanisms by which zinc acts are not yet known, it is assumed that Zn may block the diffusion paths within the oxide film. This reduces ion transport through the oxide films leading to a reduced rate of oxide growth. Simultaneously the number of available adsorption sites for 60 Co is also reduced. The current models for stress corrosion cracking assume that the anodic and the respective cathodic reactions contributing to crack growth occur partly on or in the oxide films. The rates of these reactions may control the crack propagation rate and therefore, the properties of the oxide films play a crucial role in determining the susceptibility of the material to stress corrosion cracking. Finally, attention is paid also on the novel techniques which can be used to mitigate the susceptibility of construction materials to stress corrosion cracking. (orig.)

  2. The Influence Of Modified Water Chemistries On Metal Oxide Films, Activity Build-Up And Stress Corrosion Cracking Of Structural Materials In Nuclear Power Plants

    International Nuclear Information System (INIS)

    Maekelae, K.; Laitinen, T.; Bojinov, M.

    1998-07-01

    The primary coolant oxidises the surfaces of construction materials in nuclear power plants. The properties of the oxide films influence significantly the extent of incorporation of activated corrosion products into the primary circuit surfaces, which may cause additional occupational doses for the maintenance personnel. The physical and chemical properties of the oxide films play also an important role in different forms of corrosion observed in power plants. This report gives a short overview of the factors influencing activity build-up and corrosion phenomena in nuclear power plants. Furthermore, the most recent modifications in the water chemistry to decrease these risks are discussed. A special focus is put on zinc water chemistry, and a preliminary discussion on the mechanism via which zinc influences activity build-up is presented. Even though the exact mechanisms by which zinc acts are not yet known, it is assumed that Zn may block the diffusion paths within the oxide film. This reduces ion transport through the oxide films leading to a reduced rate of oxide growth. Simultaneously the number of available adsorption sites for 60 Co is also reduced. The current models for stress corrosion cracking assume that the anodic and the respective cathodic reactions contributing to crack growth occur partly on or in the oxide films. The rates of these reactions may control the crack propagation rate and therefore, the properties of the oxide films play a crucial role in determining the susceptibility of the material to stress corrosion cracking. Finally, attention is paid also on the novel techniques which can be used to mitigate the susceptibility of construction materials to stress corrosion cracking. (author)

  3. The influence of modified water chemistries on metal oxide films, activity build-up and stress corrosion cracking of structural materials in nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Maekelae, K.; Laitinen, T.; Bojinov, M. [VTT Manufacturing Technology, Espoo (Finland)

    1999-03-01

    The primary coolant oxidises the surfaces of construction materials in nuclear power plants. The properties of the oxide films influence significantly the extent of incorporation of actuated corrosion products into the primary circuit surfaces, which may cause additional occupational doses for the maintenance personnel. The physical and chemical properties of the oxide films play also an important role in different forms of corrosion observed in power plants. This report gives a short overview of the factors influencing activity build-up and corrosion phenomena in nuclear power plants. Furthermore, the most recent modifications in the water chemistry to decrease these risks are discussed. A special focus is put on zinc water chemistry, and a preliminary discussion on the mechanism via which zinc influences activity build-up is presented. Even though the exact mechanisms by which zinc acts are not yet known, it is assumed that Zn may block the diffusion paths within the oxide film. This reduces ion transport through the oxide films leading to a reduced rate of oxide growth. Simultaneously the number of available adsorption sites for {sup 60}Co is also reduced. The current models for stress corrosion cracking assume that the anodic and the respective cathodic reactions contributing to crack growth occur partly on or in the oxide films. The rates of these reactions may control the crack propagation rate and therefore, the properties of the oxide films play a crucial role in determining the susceptibility of the material to stress corrosion cracking. Finally, attention is paid also on the novel techniques which can be used to mitigate the susceptibility of construction materials to stress corrosion cracking. (orig.) 127 refs.

  4. Interpolation of Gamma-ray buildup Factors for Arbitrary Source Energies in the Vicinity of the K-edge

    International Nuclear Information System (INIS)

    Michieli, I.

    1998-01-01

    Recently, a new buildup factors approximation formula based on the expanded polynomial set (E-P function) was successfully introduced (Michieli 1994.) with the maximum approximation error below 4% throughout the standard data domain. Buildup factors interpolation in E-P function parameters for arbitrary source energies, near the K-edge in lead, was satisfactory. Maximum interpolation error, for lead, lays within 12% what appears to be acceptable for most Point Kernel application. 1991. Harima at. al., showed that, near the K-edge, fluctuation in energy of exposure rate attenuation factors i.e.: D(E)B(E, μ E r)exp(-μ E r), given as a function of penetration depth (r) in ordinary length units (not mfps.), is not nearly as great as that of buildup factors. That phenomenon leads to the recommendation (ANSI/ANS-6.4.3) that interpolations in that energy range should be made in the attenuation factors B(E, μ E r)exp(-μ E r) rather than in the buildup factors alone. In present article, such interpolation approach is investigated by applying it to the attenuation factors in lead, with E-P function representation of exposure buildup factors. Simple form of the E-P function leads to strait calculation of new function parameters for arbitrary source energy near the K-edge and thus allowing the same representation form of buildup factors as in the standard interpolation procedure. results of the interpolation are discussed and compared with those from standard approach. (author)

  5. Internal background build-up measurements in CaF2:Mn thermoluminescent dosimeters

    International Nuclear Information System (INIS)

    Balasybrahmanyam, V.; Measures, M.P.

    1977-01-01

    Some problems associated with the internal background build-up (IBB) of CaF 2 :Mn thermoluminescent dosimeters are reported. As a result of an investigation of batches of the EG and G model 15 dosimeter it is considered that measurements using this type of dosimeter are accurate and reproducible once the IBB has been determined. However, the use of the Manufacturer's claimed average of 0.064 mR/day can lead to erroneous results when determining environmental background dose rates. The authors therefore urge a rigid quality control program by the manufacturer and suggest that purchasers should be supplied with IBB information of each batch of dosimeters. Meanwhile each user should be aware of the IBB problem and be extremely cautious when using these dosimeters for environmental monitoring purposes. (U.K.)

  6. Resonant laser power build-up in ALPS. A 'light-shining-through-walls' experiment

    International Nuclear Information System (INIS)

    Ehret, Klaus; Ghazaryan, Samvel; Frede, Maik

    2009-05-01

    The ALPS collaboration runs a light-shining-through-walls (LSW) experiment to search for photon oscillations into weakly interacting sub-eV particles (WISPs) inside of a superconducting HERA dipole magnet at the site of DESY. In this paper we report on the first successful integration of a large-scale optical cavity to boost the available power for WISP production in this type of experiments. The key elements are a frequency tunable narrow line-width continuous wave laser acting as the primary light source and an electronic feed-back control loop to stabilize the power build-up. We describe and characterize our apparatus and demonstrate the data analysis procedures on the basis of a brief exemplary run. (orig.)

  7. Early-Time Solution of the Horizontal Unconfined Aquifer in the Buildup Phase

    Science.gov (United States)

    Gravanis, Elias; Akylas, Evangelos

    2017-10-01

    We derive the early-time solution of the Boussinesq equation for the horizontal unconfined aquifer in the buildup phase under constant recharge and zero inflow. The solution is expressed as a power series of a suitable similarity variable, which is constructed so that to satisfy the boundary conditions at both ends of the aquifer, that is, it is a polynomial approximation of the exact solution. The series turns out to be asymptotic and it is regularized by resummation techniques that are used to define divergent series. The outflow rate in this regime is linear in time, and the (dimensionless) coefficient is calculated to eight significant figures. The local error of the series is quantified by its deviation from satisfying the self-similar Boussinesq equation at every point. The local error turns out to be everywhere positive, hence, so is the integrated error, which in turn quantifies the degree of convergence of the series to the exact solution.

  8. Electron-Cloud Build-up in the FNAL Main Injector

    International Nuclear Information System (INIS)

    Furman, M.A.

    2007-01-01

    We present a summary on ongoing simulation results for the electron-cloud buildup in the context of the proposed FNAL Main Injector (MI) intensity upgrade [1] in a fieldfree region at the location of the RFA electron detector [2]. By combining our simulated results for the electron flux at the vacuum chamber wall with the corresponding measurements obtained with the RFA we infer that the peak secondary electron yield (SEY) (delta) max is ∼> 1.4, and the average electron density is n e ∼> 10 10 m -3 at transition energy for the specific fill pattern and beam intensities defined below. The sensitivity of our results to several variables remains to be explored in order to reach more definitive results. Effects from the electron cloud on the beam are being investigated separately [3

  9. Particle simulation of pedestal buildup and study of pedestal scaling law in a quiescent plasma edge

    International Nuclear Information System (INIS)

    Chang, C.S.; Ku, S.; Weitzner, H.; Groebner, R.; Osborne, T.

    2005-01-01

    A discrete guiding-center particle code XGC (X-point included Guiding Center code) is used to study pedestal buildup and sheared E r formation in a quiescent plasma edge of a diverted tokamak. A neoclassical pedestal scaling law has been deduced, which shows that the density pedestal width is proportional to T i 1/2 M 1/2 /B t where T i is the ion temperature, M is ion mass and B t is the toroidal magnetic field. Dependence on the pedestal density or the poloidal magnetic field is found to be much weaker. Ion temperature pedestal is not as well defined as the density pedestal. Neoclassical electron transport rate, including the collisional heat exchange rate with ions, is too slow to be considered in the time scale of simulation (∼ 10 ms). (author)

  10. Resonant laser power build-up in ALPS-A 'light shining through a wall' experiment

    International Nuclear Information System (INIS)

    Ehret, Klaus; Frede, Maik; Ghazaryan, Samvel; Hildebrandt, Matthias; Knabbe, Ernst-Axel; Kracht, Dietmar; Lindner, Axel; List, Jenny; Meier, Tobias; Meyer, Niels; Notz, Dieter; Redondo, Javier; Ringwald, Andreas; Wiedemann, Guenter; Willke, Benno

    2009-01-01

    The ALPS Collaboration runs a 'light shining through a wall' (LSW) experiment to search for photon oscillations into 'weakly interacting sub-eV particles' (WISPs) inside of a superconducting HERA dipole magnet at the site of DESY. In this paper we report on the first successful integration of a large-scale optical resonant cavity to boost the available power for WISP production in this type of experiments. The key elements are a frequency tunable narrow line-width continuous wave laser acting as the primary light source and an electronic feed-back control loop to stabilize the power build-up. We describe and characterize our apparatus and demonstrate the data analysis procedures on the basis of a brief exemplary run.

  11. Influence of fast alpha diffusion and thermal alpha buildup on tokamak reactor performance

    International Nuclear Information System (INIS)

    Uckan, N.A.; Tolliver, J.S.; Houlberg, W.A.; Attenberger, S.E.

    1988-01-01

    The effect of fast alpha diffusion and thermal alpha accumulation on the confinement capability of a candidate Engineering Test Reactor plasma (Tokamak Ignition/Burn Experimental Reactor) in achieving ignition and steady-state driven operation has been assessed using both global and 1-1/2-dimensional transport models. Estimates are made of the threshold for radial diffusion of fast alphas and thermal alpha buildup. It is shown that a relatively low level of radial transport, when combined with large gradients in the fast alpha density, leads to a significant radial flow with a deleterious effect on plasma performance. Similarly, modest levels of thermal alpha concentration significantly influence the ignition and steady-state burn capability

  12. Investigating Future Climate Scenarios

    Science.gov (United States)

    Dempsey, Chris; Bodzin, Alec; Anastasio, David; Sahagian, Dork; Cirucci, Lori

    2012-01-01

    One of the most alarming impacts of projected climate change is a significant rise in sea level. Sea level has varied by hundreds of meters over geologic time, yet these changes have generally been slow paced, allowing ecosystems to adjust to changing land surface and marine habitats. Since the Industrial Revolution, anthropogenic emissions have…

  13. The changing nutrition scenario.

    Science.gov (United States)

    Gopalan, C

    2013-09-01

    The past seven decades have seen remarkable shifts in the nutritional scenario in India. Even up to the 1950s severe forms of malnutrition such as kwashiorkar and pellagra were endemic. As nutritionists were finding home-grown and common-sense solutions for these widespread problems, the population was burgeoning and food was scarce. The threat of widespread household food insecurity and chronic undernutrition was very real. Then came the Green Revolution. Shortages of food grains disappeared within less than a decade and India became self-sufficient in food grain production. But more insidious problems arising from this revolution were looming, and cropping patterns giving low priority to coarse grains and pulses, and monocropping led to depletion of soil nutrients and 'Green Revolution fatigue'. With improved household food security and better access to health care, clinical manifestations of severe malnutrition virtually disappeared. But the decline in chronic undernutrition and "hidden hunger" from micronutrient deficiencies was slow. On the cusp of the new century, an added factor appeared on the nutritional scene in India. With steady urban migration, upward mobility out of poverty, and an increasingly sedentary lifestyle because of improvements in technology and transport, obesity rates began to increase, resulting in a dual burden. Measured in terms of its performance in meeting its Millennium Development Goals, India has fallen short. Despite its continuing high levels of poverty and illiteracy, India has a huge demographic potential in the form of a young population. This advantage must be leveraged by investing in nutrition education, household access to nutritious diets, sanitary environment and a health-promoting lifestyle. This requires co-operation from all the stakeholders, including governments, non government organizations, scientists and the people at large.

  14. The changing nutrition scenario

    Directory of Open Access Journals (Sweden)

    C Gopalan

    2013-01-01

    Full Text Available The past seven decades have seen remarkable shifts in the nutritional scenario in India. Even up to the 1950s severe forms of malnutrition such as kwashiorkar and pellagra were endemic. As nutritionists were finding home-grown and common-sense solutions for these widespread problems, the population was burgeoning and food was scarce. The threat of widespread household food insecurity and chronic undernutrition was very real. Then came the Green Revolution. Shortages of food grains disappeared within less than a decade and India became self-sufficient in food grain production. But more insidious problems arising from this revolution were looming, and cropping patterns giving low priority to coarse grains and pulses, and monocropping led to depletion of soil nutrients and ′Green Revolution fatigue′. With improved household food security and better access to health care, clinical manifestations of severe malnutrition virtually disappeared. But the decline in chronic undernutrition and "hidden hunger" from micronutrient deficiencies was slow. On the cusp of the new century, an added factor appeared on the nutritional scene in India. With steady urban migration, upward mobility out of poverty, and an increasingly sedentary lifestyle because of improvements in technology and transport, obesity rates began to increase, resulting in a dual burden. Measured in terms of its performance in meeting its Millennium Development Goals, India has fallen short. Despite its continuing high levels of poverty and illiteracy, India has a huge demographic potential in the form of a young population. This advantage must be leveraged by investing in nutrition education, household access to nutritious diets, sanitary environment and a health-promoting lifestyle. This requires co-operation from all the stakeholders, including governments, non government organizations, scientists and the people at large.

  15. Italian energy scenarios comparative evaluations

    International Nuclear Information System (INIS)

    Contaldi, Mario

    2005-01-01

    This paper reviews some representative scenarios of the evolution of the Italian primary energy consumption, updated recently. After an overview of the main macroeconomics assumptions the scenario results are cross checked at sectorial level, with a brief discussion of the underlining data and energy intensity trends. The emissions of CO 2 , SO 2 and NO x resulting from the considered scenarios are also reported and discussed [it

  16. Learning from global emissions scenarios

    International Nuclear Information System (INIS)

    O'Neill, Brian C; Nakicenovic, Nebojsa

    2008-01-01

    Scenarios of global greenhouse gas emissions have played a key role in climate change analysis for over twenty years. Currently, several research communities are organizing to undertake a new round of scenario development in the lead-up to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC). To help inform this process, we assess a number of past efforts to develop and learn from sets of global greenhouse gas emissions scenarios. We conclude that while emissions scenario exercises have likely had substantial benefits for participating modeling teams and produced insights from individual models, learning from the exercises taken as a whole has been more limited. Model comparison exercises have typically focused on the production of large numbers of scenarios while investing little in assessing the results or the production process, perhaps on the assumption that later assessment efforts could play this role. However, much of this assessment potential remains untapped. Efforts such as scenario-related chapters of IPCC reports have been most informative when they have gone to extra lengths to carry out more specific comparison exercises, but in general these assessments do not have the remit or resources to carry out the kind of detailed analysis of scenario results necessary for drawing the most useful conclusions. We recommend that scenario comparison exercises build-in time and resources for assessing scenario results in more detail at the time when they are produced, that these exercises focus on more specific questions to improve the prospects for learning, and that additional scenario assessments are carried out separately from production exercises. We also discuss the obstacles to better assessment that might exist, and how they might be overcome. Finally, we recommend that future work include much greater emphasis on understanding how scenarios are actually used, as a guide to improving scenario production.

  17. Energy scenarios for New Zealand

    Energy Technology Data Exchange (ETDEWEB)

    Harris, G. S.; Ellis, M. J.; Scott, G. C.; Wood, J. R.

    1977-10-15

    Three energy scenarios have been formulated for New Zealand. They concentrate on those aspects of society which have a direct bearing on energy, emphasizing three important issues: major shifts in society's values in relation to material wealth, pollution, and resources. The scenarios make assumptions that certain overall social conditions would prevail so that all decisions of government, the private sector, and individuals would be governed by the requirement to conform to the scenario theme in a way not possible under existing social and political conditions. The 3 scenarios are known as Continuation, Low New Zealand Pollution, and Limited Growth.

  18. Regional groundwater flow model for a glaciation scenario. Simpevarp subarea - version 1.2

    International Nuclear Information System (INIS)

    Jaquet, O.; Siegel, P.

    2006-10-01

    A groundwater flow model (glaciation model) was developed at a regional scale in order to study long term transient effects related to a glaciation scenario likely to occur in response to climatic changes. Conceptually the glaciation model was based on the regional model of Simpevarp and was then extended to a mega-regional scale (of several hundred kilometres) in order to account for the effects of the ice sheet. These effects were modelled using transient boundary conditions provided by a dynamic ice sheet model describing the phases of glacial build-up, glacial completeness and glacial retreat needed for the glaciation scenario. The results demonstrate the strong impact of the ice sheet on the flow field, in particular during the phases of the build-up and the retreat of the ice sheet. These phases last for several thousand years and may cause large amounts of melt water to reach the level of the repository and below. The highest fluxes of melt water are located in the vicinity of the ice margin. As the ice sheet approaches the repository location, the advective effects gain dominance over diffusive effects in the flow field. In particular, up-coning effects are likely to occur at the margin of the ice sheet leading to potential increases in salinity at repository level. For the base case, the entire salinity field of the model is almost completely flushed out at the end of the glaciation period. The flow patterns are strongly governed by the location of the conductive features in the subglacial layer. The influence of these glacial features is essential for the salinity distribution as is their impact on the flow trajectories and, therefore, on the resulting performance measures. Travel times and F-factor were calculated using the method of particle tracking. Glacial effects cause major consequences on the results. In particular, average travel times from the repository to the surface are below 10 a during phases of glacial build-up and retreat. In comparison

  19. Regional groundwater flow model for a glaciation scenario. Simpevarp subarea - version 1.2

    Energy Technology Data Exchange (ETDEWEB)

    Jaquet, O.; Siegel, P. [Colenco Power Engineering Ltd, Baden-Daettwil (Switzerland)

    2006-10-15

    A groundwater flow model (glaciation model) was developed at a regional scale in order to study long term transient effects related to a glaciation scenario likely to occur in response to climatic changes. Conceptually the glaciation model was based on the regional model of Simpevarp and was then extended to a mega-regional scale (of several hundred kilometres) in order to account for the effects of the ice sheet. These effects were modelled using transient boundary conditions provided by a dynamic ice sheet model describing the phases of glacial build-up, glacial completeness and glacial retreat needed for the glaciation scenario. The results demonstrate the strong impact of the ice sheet on the flow field, in particular during the phases of the build-up and the retreat of the ice sheet. These phases last for several thousand years and may cause large amounts of melt water to reach the level of the repository and below. The highest fluxes of melt water are located in the vicinity of the ice margin. As the ice sheet approaches the repository location, the advective effects gain dominance over diffusive effects in the flow field. In particular, up-coning effects are likely to occur at the margin of the ice sheet leading to potential increases in salinity at repository level. For the base case, the entire salinity field of the model is almost completely flushed out at the end of the glaciation period. The flow patterns are strongly governed by the location of the conductive features in the subglacial layer. The influence of these glacial features is essential for the salinity distribution as is their impact on the flow trajectories and, therefore, on the resulting performance measures. Travel times and F-factor were calculated using the method of particle tracking. Glacial effects cause major consequences on the results. In particular, average travel times from the repository to the surface are below 10 a during phases of glacial build-up and retreat. In comparison

  20. Variation of energy absorption buildup factors with incident photon energy and penetration depth for some commonly used solvents

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Parjit S. [Department of Physics, Punjabi University, Patiala 147 002 (India)], E-mail: dr_parjit@hotmail.com; Singh, Tejbir [Department of Physics, Lovely Professional University, Phagwara 144 402 (India); Kaur, Paramjeet [IAS and Allied Services Training Centre, Punjabi University, Patiala 147 002 (India)

    2008-06-15

    G.P. fitting method has been used to compute energy absorption buildup factor of some commonly used solvents such as acetonitrile (C{sub 4}H{sub 3}N), butanol (C{sub 4}H{sub 9}OH), chlorobenzene (C{sub 6}H{sub 5}Cl), diethyl ether (C{sub 4}H{sub 10}O), ethanol (C{sub 2}H{sub 5}OH), methanol (CH{sub 3}OH), propanol (C{sub 3}H{sub 7}OH) and water (H{sub 2}O) for the wide energy range (0.015-15.0 MeV) up to the penetration depth of 10 mean free path. The variation of energy absorption buildup factor with chemical composition as well as incident photon energy for the selected solvents has been studied. It has been observed that the maximum value of energy absorption buildup factors shifts to the slightly higher incident photon energy with the increase in equivalent atomic number of the solvent and the solvent with least equivalent atomic number possesses the maximum value of energy absorption buildup factor.

  1. Insect Venom Immunotherapy: Analysis of the Safety and Tolerance of 3 Buildup Protocols Frequently Used in Spain.

    Science.gov (United States)

    Gutiérrez Fernández, D; Moreno-Ancillo, A; Fernández Meléndez, S; Domínguez-Noche, C; Gálvez Ruiz, P; Alfaya Arias, T; Carballada González, F; Alonso Llamazares, A; Marques Amat, L; Vega Castro, A; Antolín Amérigo, D; Cruz Granados, S; Ruiz León, B; Sánchez Morillas, L; Fernández Sánchez, J; Soriano Gomis, V; Borja Segade, J; Dalmau Duch, G; Guspi Bori, R; Miranda Páez, A

    2016-01-01

    Hymenoptera venom immunotherapy (VIT) is an effective treatment but not one devoid of risk, as both local and systemic adverse reactions may occur, especially in the initial phases. We compared the tolerance to 3 VIT buildup protocols and analyzed risk factors associated with adverse reactions during this phase. We enrolled 165 patients divided into 3 groups based on the buildup protocol used (3, 4, and 9 weeks). The severity of systemic reactions was evaluated according to the World Allergy Organization model. Results were analyzed using exploratory descriptive statistics, and variables were compared using analysis of variance. Adverse reactions were recorded in 53 patients (32%) (43 local and 10 systemic). Local reactions were immediate in 27 patients (63%) and delayed in 16 (37%). The severity of the local reaction was slight/moderate in 15 patients and severe in 13. Systemic reactions were grade 1-2. No significant association was found between the treatment modality and the onset of local or systemic adverse reactions or the type of local reaction. We only found a statistically significant association between severity of the local reaction and female gender. As for the risk factors associated with systemic reactions during the buildup phase, we found no significant differences in values depending on the protocol used or the insect responsible. The buildup protocols compared proved to be safe and did not differ significantly from one another. In the population studied, patients undergoing the 9-week schedule presented no systemic reactions. Therefore, this protocol can be considered the safest approach.

  2. Extremely rare collapse and build-up of turbulence in stochastic models of transitional wall flows.

    Science.gov (United States)

    Rolland, Joran

    2018-02-01

    This paper presents a numerical and theoretical study of multistability in two stochastic models of transitional wall flows. An algorithm dedicated to the computation of rare events is adapted on these two stochastic models. The main focus is placed on a stochastic partial differential equation model proposed by Barkley. Three types of events are computed in a systematic and reproducible manner: (i) the collapse of isolated puffs and domains initially containing their steady turbulent fraction; (ii) the puff splitting; (iii) the build-up of turbulence from the laminar base flow under a noise perturbation of vanishing variance. For build-up events, an extreme realization of the vanishing variance noise pushes the state from the laminar base flow to the most probable germ of turbulence which in turn develops into a full blown puff. For collapse events, the Reynolds number and length ranges of the two regimes of collapse of laminar-turbulent pipes, independent collapse or global collapse of puffs, is determined. The mean first passage time before each event is then systematically computed as a function of the Reynolds number r and pipe length L in the laminar-turbulent coexistence range of Reynolds number. In the case of isolated puffs, the faster-than-linear growth with Reynolds number of the logarithm of mean first passage time T before collapse is separated in two. One finds that ln(T)=A_{p}r-B_{p}, with A_{p} and B_{p} positive. Moreover, A_{p} and B_{p} are affine in the spatial integral of turbulence intensity of the puff, with the same slope. In the case of pipes initially containing the steady turbulent fraction, the length L and Reynolds number r dependence of the mean first passage time T before collapse is also separated. The author finds that T≍exp[L(Ar-B)] with A and B positive. The length and Reynolds number dependence of T are then discussed in view of the large deviations theoretical approaches of the study of mean first passage times and

  3. Extremely rare collapse and build-up of turbulence in stochastic models of transitional wall flows

    Science.gov (United States)

    Rolland, Joran

    2018-02-01

    This paper presents a numerical and theoretical study of multistability in two stochastic models of transitional wall flows. An algorithm dedicated to the computation of rare events is adapted on these two stochastic models. The main focus is placed on a stochastic partial differential equation model proposed by Barkley. Three types of events are computed in a systematic and reproducible manner: (i) the collapse of isolated puffs and domains initially containing their steady turbulent fraction; (ii) the puff splitting; (iii) the build-up of turbulence from the laminar base flow under a noise perturbation of vanishing variance. For build-up events, an extreme realization of the vanishing variance noise pushes the state from the laminar base flow to the most probable germ of turbulence which in turn develops into a full blown puff. For collapse events, the Reynolds number and length ranges of the two regimes of collapse of laminar-turbulent pipes, independent collapse or global collapse of puffs, is determined. The mean first passage time before each event is then systematically computed as a function of the Reynolds number r and pipe length L in the laminar-turbulent coexistence range of Reynolds number. In the case of isolated puffs, the faster-than-linear growth with Reynolds number of the logarithm of mean first passage time T before collapse is separated in two. One finds that ln(T ) =Apr -Bp , with Ap and Bp positive. Moreover, Ap and Bp are affine in the spatial integral of turbulence intensity of the puff, with the same slope. In the case of pipes initially containing the steady turbulent fraction, the length L and Reynolds number r dependence of the mean first passage time T before collapse is also separated. The author finds that T ≍exp[L (A r -B )] with A and B positive. The length and Reynolds number dependence of T are then discussed in view of the large deviations theoretical approaches of the study of mean first passage times and multistability

  4. Automated Analysis of Infinite Scenarios

    DEFF Research Database (Denmark)

    Buchholtz, Mikael

    2005-01-01

    The security of a network protocol crucially relies on the scenario in which the protocol is deployed. This paper describes syntactic constructs for modelling network scenarios and presents an automated analysis tool, which can guarantee that security properties hold in all of the (infinitely many...

  5. Multiscale scenarios for nature futures

    NARCIS (Netherlands)

    Rosa, Isabel M.D.; Pereira, Henrique Miguel; Ferrier, Simon; Alkemade, J.R.M.; Acosta, Lilibeth A.; Resit Akcakaya, H.; Belder, den E.; Fazel, Asghar M.; Fujimori, Shinichiro; Harfoot, Mike; Harhash, Khaled A.; Harrison, Paula A.; Hauck, Jennifer; Hendriks, Rob J.J.; Hernández, Gladys; Jetz, Walter; Karlsson-Vinkhuyzen, S.I.S.E.; Kim, Hyejin; King, Nicholas; Kok, Marcel; Kolomytsev, Grygoriy O.; Lazarova, Tanya; Leadley, Paul; Lundquist, Carolyn J.; García Márquez, Jaime; Meyer, Carsten; Navarro, Laetitia M.; Nesshöver, Carsten; Ngo, Hien T.; Ninan, Karachepone N.; Palomo, Maria G.; Pereira, Laura; Peterson, G.D.; Pichs, Ramon; Popp, Alexander; Purvis, Andy; Ravera, Federica; Rondinini, Carlo; Sathyapalan, Jyothis; Schipper, Aafke; Seppelt, Ralf; Settele, Josef; Sitas, Nadia; Vuuren, van D.

    2017-01-01

    Targets for human development are increasingly connected with targets for nature, however, existing scenarios do not explicitly address this relationship. Here, we outline a strategy to generate scenarios centred on our relationship
    with nature to inform decision-making at multiple scales.

  6. Multiscale scenarios for nature futures

    NARCIS (Netherlands)

    Rosa, Isabel M.D.; Pereira, Henrique M.; Ferrier, Simon; Alkemade, Rob; Acosta, Lilibeth A.; Akcakaya, H. Resit; Den Belder, Eefje; Fazel, Asghar M.; Fujimori, Shinichiro; Harfoot, Mike; Harhash, Khaled A.; Harrison, Paula A.; Hauck, Jennifer; Hendriks, Rob J.J.; Hernández, Gladys; Jetz, Walter; Karlsson-Vinkhuyzen, Sylvia I.; Kim, Hyejin; King, Nicholas; Kok, Marcel T.J.; Kolomytsev, Grygoriy O.; Lazarova, Tanya; Leadley, Paul; Lundquist, Carolyn J.; García Márquez, Jaime; Meyer, Carsten; Navarro, Laetitia M.; Nesshöver, Carsten; Ngo, Hien T.; Ninan, Karachepone N.; Palomo, Maria G.; Pereira, Laura M.; Peterson, Garry D.; Pichs, Ramon; Popp, Alexander; Purvis, Andy; Ravera, Federica; Rondinini, Carlo; Sathyapalan, Jyothis; Schipper, Aafke M.; Seppelt, Ralf; Settele, Josef; Sitas, Nadia; Van Vuuren, Detlef|info:eu-repo/dai/nl/11522016X

    2017-01-01

    Targets for human development are increasingly connected with targets for nature, however, existing scenarios do not explicitly address this relationship. Here, we outline a strategy to generate scenarios centred on our relationship with nature to inform decision-making at multiple scales.

  7. Scenarios of land cover in China

    Science.gov (United States)

    Yue, Tian Xiang; Fan, Ze Meng; Liu, Ji Yuan

    2007-02-01

    A method for surface modeling of land cover change (SMLC) is developed on the basis of establishing transition probability matrixes between land cover types and HLZ types. SMLC is used to simulate land cover scenarios of China for the years 2039, 2069 and 2099, for which HLZ scenarios are first simulated in terms of HadCM3 climatic scenarios that are downscaled in zonal model of spatial climate change in China. This paper also analyzes spatial distribution of land cover types, area change and mean center shift of each land cover type, ecotope diversity, and patch connectivity under the land cover scenarios. The results show that cultivated land would decrease and woodland would expand greatly with climatic change, which coincides with consequences expected by implementation of Grain-for-Green policy. Nival area would shrink, and desertification area would expand at a comparatively slow rate in future 100 years. Climate change would generally cause less ecotope diversity and more patch connectivity. Ecosystems in China would have a pattern of beneficial cycle after efficient ecological conservation and restoration. However, if human activities would exceed regulation capacity of ecosystems themselves, the ecosystems in China might deteriorate more seriously.

  8. Energy scenarios: a prospective outlook

    International Nuclear Information System (INIS)

    Salomon, Thierry; Claustre, Raphael; Charru, Madeleine; Sukov, Stephane; Marignac, Yves; Fink, Meike; Bibas, Ruben; Le Saux, Gildas

    2011-01-01

    A set of articles discusses the use of energy scenarios: how useful they can be to describe a possible future and even to gather the involved actors, how they have been used in France in the past (for planning or prediction purposes, with sometimes some over-assessed or contradictory results, without considering any decline of nuclear energy, or by setting an impossible equation in the case of the Grenelle de l'Environnement), how the scenario framework impacts its content (depending on the approach type: standard, optimization, bottom-up, top-down, or hybrid). It also discusses the issue of choice of hypotheses on growth-based and de-growth-based scenarios, outlines how energy saving is a key for a sustainable evolution. Two German scenarios regarding electricity production (centralisation or decentralisation) and French regional scenarios for Nord-Pas-de-Calais are then briefly discussed

  9. Uji ketahanan galur padi terhadap wereng coklat biotipe 3 melalui population build-up

    Directory of Open Access Journals (Sweden)

    Baehaki Suherlan Effendi

    2015-09-01

    Full Text Available Screening of rice lines resistance to brown planthopper (BPH through mass screening, filtering line resistance and the population build-up are essential for the release of resistant rice varieties. In addition, the stages of the endurance are important in determining the stability of resistance, as well as the type of resistant. The research was carried out in the screen house at Indonesian Center for Rice Research in 2007. The BPH used in the research was the off spring of BPH biotype 3 that had been rearing on IR42 (bph2 variety since 1994. The result of this research showed that 22.2% of 18 lines/varieties were moderately resistant to BPH biotype 3ft namely BP4130-1f-13-3-2*B, BP4188-7f-1-2-2*B, BP2870-4e- Kn-22-2-1-5*B, and Pulut Lewok. On the population build-up test, the above lines/varieties were moderately resistant to BPH biotype 3pb. The low FPLI values were found in BP4130-1f-13-3-2*B and Pulut Lewok. The highest tolerance index was found on BP4130-1f- 13-3-2*B and Pulut Lewok followed by BP2870-4e-Kn-22-2-1-5*B and BP4188-7f-1-2-2*B. Pulut Lewok has the highest antibiosis index and is not significantly different to BP4130-1f-13-3-2*B, while BP4188-7f-1-2-2*B was lowest. Although Pulut Lewok has antibiosis defense mechanism, it is not tolerant to BPH biotype 3. The BP4130-1f-13-3-2*B line have both antibiosis and tolerant to BPH biotype 3. BP4188-7f-1-2-2*B line has tolerance character, but does not have character of antibiosis to BPH biotype 3.

  10. Comprehensive update on cancer scenario of Bangladesh

    Directory of Open Access Journals (Sweden)

    Syed Md Akram Hussain

    2013-01-01

    Full Text Available Bangladesh, at 142 million people, is the ninth most populous country in the world. There are 13 to 15 lakh cancer patients in Bangladesh, with about two lakh patients newly diagnosed with cancer each year. As an overview, lung cancer and mouth-oropharynx cancer rank as the top two prevalent cancers in males. Other types of cancers are esophagus cancer and stomach cancer. In women, cancer cervix uteri and breast cancer are most prevalent. Other cancer types, which affect women, are mouth and oropharynx cancer, lung cancer, and esophagus cancer. There are around 150 qualified clinical oncologists and 16 pediatric oncologists working in the different parts of the country. Regular cancer treatment is available in 19 hospitals and 465 hospital beds are attached as indoor or day care facilities for chemotherapy in the oncology/radiotherapy departments. There are about 15 linear accelerators, 12 Co-60 teletherapy and 12 brachytherapy units currently available. Approximately, 56 cancer chemotherapeutic agents are obtainable in Bangladesh. Research facilities are available at tertiary care centers and a few multi country collaborative research activities are ongoing. Bangladesh has a unique National Cancer Control Strategy and Plan of Action 2009-2015 formulated with the assistance of WHO with an objective to develop and implement continuum of cancer care through a comprehensive cancer control programe. Preventive measures taken to reduce the incidence of cancer include reduced tobacco smoking, change of dietary habit and reduced food adulteration, ensuring reproductive hygiene, increased physical activity, and reduced occupational hazard. Awareness buildup and media campaign are going on by organizing the general people, opinion leaders of the society, and boy and girl scout. Training of general physicians on cancer warning signs and setup of early cancer detection centers at each medical college and district levels are ongoing. Beside these, some

  11. Dying scenarios improve recall as much as survival scenarios.

    Science.gov (United States)

    Burns, Daniel J; Hart, Joshua; Kramer, Melanie E

    2014-01-01

    Merely contemplating one's death improves retention for entirely unrelated material learned subsequently. This "dying to remember" effect seems conceptually related to the survival processing effect, whereby processing items for their relevance to being stranded in the grasslands leads to recall superior to that of other deep processing control conditions. The present experiments directly compared survival processing scenarios with "death processing" scenarios. Results showed that when the survival and dying scenarios are closely matched on key dimensions, and possible congruency effects are controlled, the dying and survival scenarios produced equivalently high recall levels. We conclude that the available evidence (cf. Bell, Roer, & Buchner, 2013; Klein, 2012), while not definitive, is consistent with the possibility of overlapping mechanisms.

  12. Process and equipment for pressure build-up in nuclear reactor fuel rods

    International Nuclear Information System (INIS)

    Heer, W.F.; Carli, E.V. de.

    1976-01-01

    The equipment makes possible the build-up of inert gas pressure in a filled and closed fuel can, i.e. in a complete fuel rod. Handling is simple, it is suitable for mass production and only causes low processing costs. The quality, e.g. the degree of purity of the contents of the rod, remains unchangedin processing. The equipment consists of a vacuum-tight space, into which the equally vacuum tight fuel rod is introduced, and can be fixed so that its position can be reproduced unmistakeably. The vacuum space contains a connection for the inert gases and a laser arrangement. After inserting a fuel rod into the facility, this is evacuated and the fuel can has a hole bored in it by a laser beam. After fast equalisation of pressure, an inert gas at the required pressure is introduced into the chamber and the fuel rod. After the filling process is completed, the fuel can is closed again with the same laser beam. The quality of the seal obtained, i.e the leak-tightness of the fuel can, can be checked after reduction of the inert gas pressure and before taking out the fuel rod, by repeated evacuation of the chamber. Laser light energies between 13,000 and 110,000 Joule/sq cm are sufficient. Optimum results were obtained for a Zircaloy fuel can with about 52,000 Joule/sq cm. (TK) [de

  13. Comparative study of mechanical properties of direct core build-up materials

    Directory of Open Access Journals (Sweden)

    Girish Kumar

    2015-01-01

    Full Text Available Background and Objectives: The strength greatly influences the selection of core material because core must withstand forces due to mastication and para-function for many years. This study was conducted to evaluate certain mechanical properties of commonly used materials for direct core build-up, including visible light cured composite, polyacid modified composite, resin modified glass ionomer, high copper amalgam, and silver cermet cement. Materials and Methods: All the materials were manipulated according to the manufacturer′s recommendations and standard test specimens were prepared. A universal testing machine at different cross-head speed was used to determine all the four mechanical properties. Mean compressive strength, diametral tensile strength, flexural strength, and elastic modulus with standard deviations were calculated. Multiple comparisons of the materials were also done. Results: Considerable differences in compressive strength, diametral tensile strength, and flexural strength were observed. Visible light cured composite showed relatively high compressive strength, diametral tensile strength, and flexural strength compared with the other tested materials. Amalgam showed the highest value for elastic modulus. Silver cermet showed less value for all the properties except for elastic modulus. Conclusions: Strength is one of the most important criteria for selection of a core material. Stronger materials better resist deformation and fracture provide more equitable stress distribution, greater stability, and greater probability of clinical success.

  14. The Build-Up Course of Visuo-Motor and Audio-Motor Temporal Recalibration

    Directory of Open Access Journals (Sweden)

    Yoshimori Sugano

    2011-10-01

    Full Text Available The sensorimotor timing is recalibrated after a brief exposure to a delayed feedback of voluntary actions (temporal recalibration effect: TRE (Heron et al., 2009; Stetson et al., 2006; Sugano et al., 2010. We introduce a new paradigm, namely ‘synchronous tapping’ (ST which allows us to investigate how the TRE builds up during adaptation. In each experimental trial, participants were repeatedly exposed to a constant lag (∼150 ms between their voluntary action (pressing a mouse and a feedback stimulus (a visual flash / an auditory click 10 times. Immediately after that, they performed a ST task with the same stimulus as a pace signal (7 flashes / clicks. A subjective ‘no-delay condition’ (∼50 ms served as control. The TRE manifested itself as a change in the tap-stimulus asynchrony that compensated the exposed lag (eg, after lag adaptation, the tap preceded the stimulus more than in control and built up quickly (∼3–6 trials, ∼23–45 sec in both the visuo- and audio-motor domain. The audio-motor TRE was bigger and built-up faster than the visuo-motor one. To conclude, the TRE is comparable between visuo- and audio-motor domain, though they are slightly different in size and build-up rate.

  15. Kick-Off Point (KOP and End of Buildup (EOB Data Analysis in Trajectory Design

    Directory of Open Access Journals (Sweden)

    Novrianti Novrianti

    2017-06-01

    Full Text Available Well X is a development well which is directionally drilled. Directional drilling is choosen because the coordinate target of Well X is above the buffer zone. The directional track plan needs accurate survey calculation in order to make the righ track for directional drilling. There are many survey calculation in directional drilling such as tangential, underbalance, average angle, radius of curvature, and mercury method. Minimum curvature method is used in this directional track plan calculation. This method is used because it gives less error than other method.  Kick-Off Point (KOP and End of Buildup (EOB analysis is done at 200 ft, 400 ft, and 600 ft depth to determine the trajectory design and optimal inclination. The hole problem is also determined in this trajectory track design. Optimal trajectory design determined at 200 ft depth because the inclination below 35º and also already reach the target quite well at 1632.28 ft TVD and 408.16 AHD. The optimal inclination at 200 ft KOP depth because the maximum inclination is 18.87º which is below 35º. Hole problem will occur if the trajectory designed at 600 ft. The problems are stuck pipe and the casing or tubing will not able to bend.

  16. Correction of build-up factor one x-ray hvl measurement

    International Nuclear Information System (INIS)

    Yuliati, Helfi; Akhadi, Mukhlis

    2000-01-01

    Research to obtain the value build-up factor (b) on half value layers (HVL) measurement of diagnostic X-Rays using pocket dosimeter behind aluminium (AI) filter with its thickness vary from 1 to 4 mm. From the measurement it was obtained HVL value of 1.997, 2.596 and 2.718 mmAI for X-Rays of kVp : 80 Kv with 1, 2, 3 and 4 mm filter thickness respectively. HVL value significantly increase with increasing AI filter thickness. Increasing of HVL means increasing filter thickness. From the calculation it was obtained increasing b value relative to 1 mm AI filter of 18.26 and 46% for filter thickness of 2, 3 and 4 mm respectively. Experiment result shows the need of involving b value in HVL calculation of X-Rays if the filter is relatively thick. Calculation of HVL of X-Rays can be carried out with thin layers filter. Key words : x-rays, half value layer, build up factor

  17. Development of fitting methods using geometric progression formulae of gamma-ray buildup factors

    International Nuclear Information System (INIS)

    Yoshida, Yoshitaka

    2006-01-01

    The gamma ray buildup factors are represented by an approximation method to speed up calculation using the point attenuation kernel method. The fitting parameters obtained by the GP formula and Taylor's formula are compiled in ANSI/ANS 6.4.3, available without any limitation. The GP formula featured high accuracy but required a high-level fitting technique. Thus the GP formula was divided into a curved line and a part representing the base values and used to develop the a fitting method and X k fitting method. As a result, this methodology showed that (1) when the fitting ranges were identical, there was no change in standard deviation when the unit penetration depth was varied; (2) even with fitting up to 300 mfp, the average standard deviation of 26 materials was 2.9% and acceptable GP parameters were extracted; (3) when the same end points of the fitting were selected and the starting points of fitting were identical with the unit penetration depth, the deviation became smaller with increasing unit penetration depth; and (4) even with the deviation adjusted to the positive side from 0.5 mfp to 300 mfp, the average standard deviation of 26 materials was 5.6%, which was an acceptable value. However, the GP parameters obtained by this methodology cannot be used for direct interpolation using gamma ray energy or materials. (author)

  18. Scenario simulation based assessment of subsurface energy storage

    Science.gov (United States)

    Beyer, C.; Bauer, S.; Dahmke, A.

    2014-12-01

    Energy production from renewable sources such as solar or wind power is characterized by temporally varying power supply. The politically intended transition towards renewable energies in Germany („Energiewende") hence requires the installation of energy storage technologies to compensate for the fluctuating production. In this context, subsurface energy storage represents a viable option due to large potential storage capacities and the wide prevalence of suited geological formations. Technologies for subsurface energy storage comprise cavern or deep porous media storage of synthetic hydrogen or methane from electrolysis and methanization, or compressed air, as well as heat storage in shallow or moderately deep porous formations. Pressure build-up, fluid displacement or temperature changes induced by such operations may affect local and regional groundwater flow, geomechanical behavior, groundwater geochemistry and microbiology. Moreover, subsurface energy storage may interact and possibly be in conflict with other "uses" like drinking water abstraction or ecological goods and functions. An utilization of the subsurface for energy storage therefore requires an adequate system and process understanding for the evaluation and assessment of possible impacts of specific storage operations on other types of subsurface use, the affected environment and protected entities. This contribution presents the framework of the ANGUS+ project, in which tools and methods are developed for these types of assessments. Synthetic but still realistic scenarios of geological energy storage are derived and parameterized for representative North German storage sites by data acquisition and evaluation, and experimental work. Coupled numerical hydraulic, thermal, mechanical and reactive transport (THMC) simulation tools are developed and applied to simulate the energy storage and subsurface usage scenarios, which are analyzed for an assessment and generalization of the imposed THMC

  19. Scenario Planning as Organizational Intervention

    DEFF Research Database (Denmark)

    Balarezo, Jose; Nielsen, Bo Bernhard

    2017-01-01

    existing contributions on scenario planning within a new consolidating framework that includes antecedents, processes, and outcomes. The proposed framework allows for integration of the extant literature on scenario planning from a wide variety of fields, including strategic management, finance, human...... resource management, operations management, and psychology. Findings: This study contributes to research by offering a coherent and consistent framework for understanding scenario planning as a dynamic process. As such, it offers future researchers with a systematic way to ascertain where a particular......Purpose: This paper identifies four areas in need of future research to enhance our theoretical understanding of scenario planning, and sets the basis for future empirical examination of its effects on individual and organizational level outcomes. Design/methodology/approach: This paper organizes...

  20. Economic assessment of energetic scenarios

    International Nuclear Information System (INIS)

    Grandjean, Alain; Bureau, Dominique; Schubert, Katheline; Henriet, Fanny; Maggiar, Nicolas; Criqui, Patrick; Le Teno, Helene; Baumstark, Luc; Crassous, Renaud; Roques, Fabien

    2013-09-01

    This publication gathers contributions proposed by different members of the Economic Council for a Sustainable Development (CEDD) on the issue of energy transition, and more precisely on scenarios elaborated with respect to energy transition. A first set of contributions addresses models of energy transition (assessment of scenario costs to reach a factor 4; the issue of de-carbonation of energy consumption; study of ELECsim, a tool to highlight costs of scenarios of evolution of the electric power system). The second part addresses arbitrations and choice assessment (the importance of social and economic impacts of scenarios; challenges related to the joint definition of the discount rate and of the evolution of carbon value in time; the issue of assessment of the integration of renewable energies into the power system)

  1. Shipping container response to three severe railway accident scenarios

    International Nuclear Information System (INIS)

    Mok, G.C.; Fischer, L.E.; Murty, S.S.; Witte, M.C.

    1998-01-01

    The probability of damage and the potential resulting hazards are analyzed for a representative rail shipping container for three severe rail accident scenarios. The scenarios are: (1) the rupture of closure bolts and resulting opening of closure lid due to a severe impact, (2) the puncture of container by an impacting rail-car coupler, and (3) the yielding of container due to side impact on a rigid uneven surface. The analysis results indicate that scenario 2 is a physically unreasonable event while the probabilities of a significant loss of containment in scenarios 1 and 3 are extremely small. Before assessing the potential risk for the last two scenarios, the uncertainties in predicting complex phenomena for rare, high- consequence hazards needs to be addressed using a rigorous methodology

  2. Scenarios, targets, gaps, and costs

    Energy Technology Data Exchange (ETDEWEB)

    Edmonds, James A.; Joos, Fortunat; Nakicenovic, Nebojsa; Richels, Richard G.; Sarmiento, Jorge L.

    2005-03-30

    This paper explores the connection between human activities and the concentration of carbon dioxide in the atmosphere. t explores the implication of the wide range of emissions scenarios developed by the IPCC in the Special Report on Emissions Scenarios and concludes that a robust finding is that major changes will be required in the global energy system if the concentration of carbon dioxide is eventually to be stabilized.

  3. Italian energy scenarios: Markal model

    International Nuclear Information System (INIS)

    Gracceva, Francesco

    2005-01-01

    Energy scenarios carried out through formal models comply with scientific criteria such as internal coherence and transparency. Besides, Markal methodology allows a good understanding of the complex nature of the energy system. The business-as-usual scenario carried out through the Markal-Italy model shows that structural changes occurring in end-use sectors will continue to drive up energy consumption, in spite of the slow economic growth and the quite high energy prices [it

  4. Scenarios for remote gas production

    International Nuclear Information System (INIS)

    Tangen, Grethe; Molnvik, Mona J.

    2009-01-01

    The amount of natural gas resources accessible via proven production technology and existing infrastructure is declining. Therefore, smaller and less accessible gas fields are considered for commercial exploitation. The research project Enabling production of remote gas builds knowledge and technology aiming at developing competitive remote gas production based on floating LNG and chemical gas conversion. In this project, scenarios are used as basis for directing research related to topics that affect the overall design and operation of such plants. Selected research areas are safety, environment, power supply, operability and control. The paper summarises the scenario building process as a common effort among research institutes and industry. Further, it documents four scenarios for production of remote gas and outlines how the scenarios are applied to establish research strategies and adequate plans in a multidisciplinary project. To ensure relevance of the scenarios, it is important to adapt the building process to the current problem and the scenarios should be developed with extensive participation of key personnel.

  5. Internal filtration and external filter cake build-up in sandstones

    NARCIS (Netherlands)

    Al-Abduwani, F.A.H.

    2005-01-01

    Water injection is an integral constituent of most field development scenarios. This injection may take place for secondary recovery and pressure maintenance such as sea water injection. Alternatively, it may take place as a waste water disposal method as in the case of produced water re-injection.

  6. SU-E-T-59: Calculations of Collimator Scatter Factors (Sc) with and Without Custom-Made Build-Up Caps for CyberKnife

    Energy Technology Data Exchange (ETDEWEB)

    Wokoma, S; Yoon, J; Jung, J [East Carolina University, Greenville, NC (United States); Lee, S [Rhode Island Hospital / Warren Alpert Medical, Providence, RI (United States)

    2014-06-01

    Purpose: To investigate the impact of custom-made build-up caps for a diode detector in robotic radiosurgery radiation fields with variable collimator (IRIS) for collimator scatter factor (Sc) calculation. Methods: An acrylic cap was custom-made to fit our SFD (IBA Dosimetry, Germany) diode detector. The cap has thickness of 5 cm, corresponding to a depth beyond electron contamination. IAEA phase space data was used for beam modeling and DOSRZnrc code was used to model the detector. The detector was positioned at 80 cm source-to-detector distance. Calculations were performed with the SFD, with and without the build-up cap, for clinical IRIS settings ranging from 7.5 to 60 mm. Results: The collimator scatter factors were calculated with and without 5 cm build-up cap. They were agreed within 3% difference except 15 mm cone. The Sc factor for 15 mm cone without buildup was 13.2% lower than that with buildup. Conclusion: Sc data is a critical component in advanced algorithms for treatment planning in order to calculate the dose accurately. After incorporating build-up cap, we discovered differences of up to 13.2 % in Sc factors in the SFD detector, when compared against in-air measurements without build-up caps.

  7. Humidity Build-Up in a Typical Electronic Enclosure Exposed to Cycling Conditions and Effect on Corrosion Reliability

    DEFF Research Database (Denmark)

    Conseil, Helene; Gudla, Visweswara Chakravarthy; Jellesen, Morten Stendahl

    2016-01-01

    The design of electronic device enclosures plays a major role in determining the humidity build-up inside the device as a response to the varying external humidity. Therefore, the corrosion reliability of electronic devices has direct connection to the enclosure design. This paper describes......, thermal mass, and port/opening size. The effect of the internal humidity build-up on corrosion reliability has been evaluated by measuring the leakage current (LC) on interdigitated test comb patterns, which are precontaminated with sodium chloride and placed inside the enclosure. The results showed...... that the exposure to cycling temperature causes significant change of internal water vapor concentration. The maximum value of humidity reached was a function of the opening size and the presence of thermal mass inside the enclosure. A pumping effect was observed due to cycling temperature, and the increase...

  8. A study of energy and effective atomic number dependence of the exposure build-up factors in biological samples

    International Nuclear Information System (INIS)

    Sidhu, G.S.; Singh, P.S.; Mudahar, G.S.

    2000-01-01

    A theoretical method is presented to determine the gamma-radiation build-up factors in various biological materials. The gamma energy range is 0.015-15.0 MeV, with penetration depths up to 40 mean free paths considered. The dependence of the exposure build-up factor on incident photon energy and the effective atomic number (Z eff ) has also been assessed. In a practical analysis of dose burden to gamma-irradiated biological materials, the sophistication of Monte Carlo computer techniques would be applied, with associated detailed modelling. However, a feature of the theoretical method presented is its ability to make the consequences of the physics of the scattering process in biological materials more transparent. In addition, it can be quickly employed to give a first-pass dose estimate prior to a more detailed computer study. (author)

  9. SU-F-T-93: Breast Surface Dose Enhancement Using a Clinical Prone Breast Board

    International Nuclear Information System (INIS)

    Guerra, M; Jozsef, G

    2016-01-01

    Purpose: The use of specialized patient set-up devices in radiotherapy, such as prone breast boards, may have unwanted dosimetric effects. The goal of this study was to evaluate the effect of a clinically used prone breast board on skin dose due to buildup. Methods: GafChromic film (EBT3) was used for dose measurements on the surface of a solid water phantom shaped to mimic the curvature of the breast. We investigated two setup scenarios: the medial field border placed at the medial edge of the board and 1 cm contralaterally from that edge. A strip of film was taped to the medial surface of the phantom. Gantry angles varied from 10 to 30 degrees below the lateral gantry position, representing anterior oblique fields. The measurements were performed with and without the presence of the board; the ratio of their corresponding doses (dose enhancement) was evaluated. Results: For the cases where the field edge is at the edge of the board, the dose enhancement is negligible for all the tested angles. When the field edge is 1 cm inside the board, the maximum surface dose enhancement varies depending on the gantry angle between 2.2 for 30 degrees and 3.2 for 20 degrees. The length on the film at which the presence of the board is detectable (i.e. where there is dose enhancement) is longer for the shallower angles. Conclusion: Even the low-density, thin carbon fiber board with a thin soft foam pad on the top can produce significant dose enhancement on the skin in prone breast treatment due to loss of buildup. However, it happens only when the patient mid-sternum is over the board, i.e. the medial edge of the field traverses through the board and pad. Even then, the effect occurs only at the field edge, i.e. the penumbral region.

  10. A THEORETICAL STUDY OF THE BUILD-UP OF THE SUN’S POLAR MAGNETIC FIELD BY USING A 3D KINEMATIC DYNAMO MODEL

    Energy Technology Data Exchange (ETDEWEB)

    Hazra, Gopal; Choudhuri, Arnab Rai [Department of Physics, Indian Institute of Science, Bangalore, 560012 (India); Miesch, Mark S., E-mail: ghazra@physics.iisc.ernet.in, E-mail: arnab@physics.iisc.ernet.in, E-mail: miesch@ucar.edu [High Altitude Observatory, National Center for Atmospheric Research, Boulder, CO 80301 (United States)

    2017-01-20

    We develop a three-dimensional kinematic self-sustaining model of the solar dynamo in which the poloidal field generation is from tilted bipolar sunspot pairs placed on the solar surface above regions of strong toroidal field by using the SpotMaker algorithm, and then the transport of this poloidal field to the tachocline is primarily caused by turbulent diffusion. We obtain a dipolar solution within a certain range of parameters. We use this model to study the build-up of the polar magnetic field and show that some insights obtained from surface flux transport models have to be revised. We present results obtained by putting a single bipolar sunspot pair in a hemisphere and two symmetrical sunspot pairs in two hemispheres. We find that the polar fields produced by them disappear due to the upward advection of poloidal flux at low latitudes, which emerges as oppositely signed radial flux and which is then advected poleward by the meridional flow. We also study the effect that a large sunspot pair, violating Hale’s polarity law, would have on the polar field. We find that there would be some effect—especially if the anti-Hale pair appears at high latitudes in the mid-phase of the cycle—though the effect is not very dramatic.

  11. Measurement of exposure buildup factors: The influence of scattered photons on gamma-ray attenuation coefficients

    Science.gov (United States)

    Mann, Kulwinder Singh

    2018-01-01

    Scattered photon's influence on measured values of attenuation coefficients (μm, cm2g-1) for six low-Z (effective atomic number) building materials, at three photon energies has been estimated. Narrow-beam transmission geometry has been used for the measurements. Samples of commonly used engineering materials (Cements, Clay, Lime-Stone, Plaster of Paris) have been selected for the present study. Standard radioactive sources Cs137 and Co60 have been used for obtaining γ-ray energies 661.66, 1173.24 and 1332.50 keV. The optical thickness (OT) of 0.5 mfp (mean free path) has been found the optimum optical thickness (OOT) for μm-measurement in the selected energy range (661.66-1332.50 keV). The aim of this investigation is to provide neglected information regarding subsistence of scattered photons in narrow beam geometry measurements for low-Z materials. The measurements have been performed for a wide range of sample-thickness (2-26 cm) such that their OT varies between 0.2-3.5 mfp in selected energy range. A computer program (GRIC2-toolkit) has been used for various theoretical computations required in this investigation. It has been concluded that in selected energy-range, good accuracy in μm-measurement of low-Z materials can be achieved by keeping their sample's OT below 0.5 mfp. The exposure buildup factors have been measured with the help of mathematical-model developed in this investigation.

  12. Hydropower build-up and the timber floating in Northern Finland after the Second World War

    Energy Technology Data Exchange (ETDEWEB)

    Haenninen, N. (Univ. of Oulu, Thule Inst. (Finland)). email: niko.hanninen@oulu.fi

    2009-07-01

    During the Second World War, Finland lost a substantial amount of built and yet un-built hydropower capacity to Soviet Union due to loss of Karelia. The most significant energy user at the time was the forest industry, especially paper and pulp mills, which had to replace this loss and to secure uninterrupted supply of energy in the future; otherwise the industry could not realise their expansion plans. One solution was to harness the still untouched northern waters for the service of the industry and society in large. However, these rivers served already the forest industry in another way, as transport routes in floating of timber. Vast waterways had made the emergence of forest industry in Finland possible. Transportation of timber from distant forests, located more than hundreds of kilometres away from the mills, was possible using rivers and lakes. Especially in Northern Finland the industry had to rely on floating as the railway network was less extensive than in some other parts of the country. The objective of this paper is to study closer, how the emergence of vast hydropower dams in these northern rivers from late 1940's to 1970's changed the transportation of timber. Road transportation in particular could not compete with floating because of their higher costs and the lack of suitable trucks and roads, but this changed after the war. Despite the fact that expanding industries consumed more and more timber, the role of floating decreased. But how did these ratios change during this period? Did the build-up of hydropower plants contribute to this shift of timber transportations from waterways to the land? Salmon and logs did not fit on the same river, the fishermen had to yield in the end. Did the hydropower plants do the same to the floaters

  13. Reducing the rate of carbon dioxide buildup with biomass fuel under climate change

    International Nuclear Information System (INIS)

    Peart, R.; Curry, R.; Jones, J.; Boote, K.; Allen, L.

    1993-01-01

    The authors have been working for several years on estimating, through crop simulation and crop growth chamber experiments, the changes in yield and in irrigation demand which would be brought about by a doubling of atmospheric greenhouse gases, given the results of three General Circulation Models (GCM) that simulate the climate change that would be expected. They are now beginning to study the impact this might have in relation to biomass fuels. An important question is the effect of the changed climate on crop production, would the increased carbon dioxide concentration outweigh the negative climate change effects on crop yields? Results are quite variable due to different climate change effects at different locations and the differences in historical weather and in soils in different locations. However, on balance, climate change would result in reduced yields of the crops we studied, soybean, maize and peanut. However, US production of these crops could be maintained or increased by the use of irrigation on more acres. Irrigated crops, in general, would have increased yields under climate change because of the increased photosynthetic efficiency with higher carbon dioxide levels. Results on net remediation of carbon dioxide buildup by the use of biomass fuel rather than fossil fuel are not completed, but previous work has shown that Midwest non-irrigated maize production provides much more equivalent biomass energy than is required for its production. The studies with soybean show a ratio of equivalent energy output in the seed to energy used in producing the crop ranging from 4 to almost 9 under climate change

  14. Venom Immunotherapy in High-Risk Patients: The Advantage of the Rush Build-Up Protocol.

    Science.gov (United States)

    Rosman, Yossi; Confino-Cohen, Ronit; Goldberg, Arnon

    2017-01-01

    Venom immunotherapy (VIT) is considered to be the gold standard treatment for patients with hymenoptera venom allergy. This treatment induces systemic reactions (SR) in a significant number of patients. To evaluate the outcome of VIT in patients with known risk factors for VIT-induced SR and to compare rush VIT (RVIT) and conventional VIT (CVIT). All of the patients who received VIT and had at least one of the following risk factors were included: current cardiovascular disease, uncontrolled asthma, high basal serum tryptase, current treatment with β-blockers or angiotensin-converting enzyme inhibitors, and age >70 or bee venom. Thirty-five (54.7%) patients underwent RVIT and 29 CVIT. The incidence of patients who developed SR during the build-up phase was similar for RVIT and CVIT (25.7 and 27.5%, respectively; p = 1). However, the incidence of SR per injection was significantly higher in CVIT than in RVIT (5.6 and 2.75%, respectively; p = 0.01). Most reactions (79.1%) were mild, limited to the skin. Most of the patients (92.1%) reached the full maintenance dose of 100 μg. This dose was reached by a significantly larger number of patients receiving RVIT compared to CVIT (100 and 82.7%, respectively; p = 0.01). None of the patients experienced exacerbation of their concurrent chronic disease during VIT. VIT can be performed safely and efficiently in patients with risk factors for immunotherapy. In these patients RVIT appears to be safer and more efficient than CVIT. © 2017 S. Karger AG, Basel.

  15. Simulations of the electron cloud buildup and its influence on the microwave transmission measurement

    Energy Technology Data Exchange (ETDEWEB)

    Haas, Oliver Sebastian, E-mail: o.haas@gsi.de [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt (Germany); Boine-Frankenheim, Oliver [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt (Germany); Technische Universität Darmstadt, Institut für Theorie Elektromagnetischer Felder, Schlossgartenstraße 8, 64289 Darmstadt (Germany); Petrov, Fedor [Technische Universität Darmstadt, Institut für Theorie Elektromagnetischer Felder, Schlossgartenstraße 8, 64289 Darmstadt (Germany)

    2013-11-21

    An electron cloud density in an accelerator can be measured using the Microwave Transmission (MWT) method. The aim of our study is to evaluate the influence of a realistic, nonuniform electron cloud on the MWT. We conduct electron cloud buildup simulations for beam pipe geometries and bunch parameters resembling roughly the conditions in the CERN SPS. For different microwave waveguide modes the phase shift induced by a known electron cloud density is obtained from three different approaches: 3D Particle-In-Cell (PIC) simulation of the electron response, a 2D eigenvalue solver for waveguide modes assuming a dielectric response function for cold electrons, a perturbative method assuming a sufficiently smooth density profile. While several electron cloud parameters, such as temperature, result in minor errors in the determined density, the transversely inhomogeneous density can introduce a large error in the measured electron density. We show that the perturbative approach is sufficient to describe the phase shift under realistic electron cloud conditions. Depending on the geometry of the beam pipe, the external magnetic field configuration and the used waveguide mode, the electron cloud density can be concentrated at the beam pipe or near the beam pipe center, leading to a severe over- or underestimation of the electron density. -- Author-Highlights: •Electron cloud distributions are very inhomogeneous, especially in dipoles. •These inhomogeneities affect the microwave transmission measurement results. •Electron density might be over- or underestimated, depending on setup. •This can be quantified with several models, e.g. a perturbative approach.

  16. Effect of curing mode on the hardness of dual-cured composite resin core build-up materials

    Directory of Open Access Journals (Sweden)

    César Augusto Galvão Arrais

    2010-06-01

    Full Text Available This study evaluated the Knoop Hardness (KHN values of two dual-cured composite resin core build-up materials and one resin cement exposed to different curing conditions. Two dual-cured core build-up composite resins (LuxaCore®-Dual, DMG; and FluoroCore®2, Dentsply Caulk, and one dual-cured resin cement (Rely X ARC, 3M ESPE were used in the present study. The composite materials were placed into a cylindrical matrix (2 mm in height and 3 mm in diameter, and the specimens thus produced were either light-activated for 40 s (Optilux 501, Demetron Kerr or were allowed to self-cure for 10 min in the dark (n = 5. All specimens were then stored in humidity at 37°C for 24 h in the dark and were subjected to KHN analysis. The results were submitted to 2-way ANOVA and Tukey's post-hoc test at a pre-set alpha of 5%. All the light-activated groups exhibited higher KHN values than the self-cured ones (p = 0.00001, regardless of product. Among the self-cured groups, both composite resin core build-up materials showed higher KHN values than the dual-cured resin cement (p = 0.00001. LuxaCore®-Dual exhibited higher KHN values than FluoroCore®2 (p = 0.00001 when they were allowed to self-cure, while no significant differences in KHN values were observed among the light-activated products. The results suggest that dual-cured composite resin core build-up materials may be more reliable than dual-cured resin cements when curing light is not available.

  17. Full steady state LH scenarios in Tore Supra

    International Nuclear Information System (INIS)

    Kazarian-Vibert, F.; Litaudon, X.; Arslanbekov, R.; Hoang, G.T.; Moreau, D.; Peysson, Y.

    1995-01-01

    Lower Hybrid discharge have been realised in Tore Supra using feed-back control of the primary circuit voltage such that the loop voltage was maintained exactly to zero near the plasma surface. This new scenario allows the plasma current to float and quickly reach an equilibrium value determined by the current drive efficiency and Lower Hybrid power. Recent experimental results show that, with the new constant flux scenario the coupled plasma and primary currents reach a steady state in less than 10 s which is a good agreement with theoretical expectations. A complete analysis of this scenario is presented. (authors). 8 refs., 3 figs

  18. Source term evaluation model for high-level radioactive waste repository with decay chain build-up.

    Science.gov (United States)

    Chopra, Manish; Sunny, Faby; Oza, R B

    2016-09-18

    A source term model based on two-component leach flux concept is developed for a high-level radioactive waste repository. The long-lived radionuclides associated with high-level waste may give rise to the build-up of activity because of radioactive decay chains. The ingrowths of progeny are incorporated in the model using Bateman decay chain build-up equations. The model is applied to different radionuclides present in the high-level radioactive waste, which form a part of decay chains (4n to 4n + 3 series), and the activity of the parent and daughter radionuclides leaching out of the waste matrix is estimated. Two cases are considered: one when only parent is present initially in the waste and another where daughters are also initially present in the waste matrix. The incorporation of in situ production of daughter radionuclides in the source is important to carry out realistic estimates. It is shown that the inclusion of decay chain build-up is essential to avoid underestimation of the radiological impact assessment of the repository. The model can be a useful tool for evaluating the source term of the radionuclide transport models used for the radiological impact assessment of high-level radioactive waste repositories.

  19. Urban nonpoint source pollution buildup and washoff models for simulating storm runoff quality in the Los Angeles County

    International Nuclear Information System (INIS)

    Wang Long; Wei Jiahua; Huang Yuefei; Wang Guangqian; Maqsood, Imran

    2011-01-01

    Many urban nonpoint source pollution models utilize pollutant buildup and washoff functions to simulate storm runoff quality of urban catchments. In this paper, two urban pollutant washoff load models are derived using pollutant buildup and washoff functions. The first model assumes that there is no residual pollutant after a storm event while the second one assumes that there is always residual pollutant after each storm event. The developed models are calibrated and verified with observed data from an urban catchment in the Los Angeles County. The application results show that the developed model with consideration of residual pollutant is more capable of simulating nonpoint source pollution from urban storm runoff than that without consideration of residual pollutant. For the study area, residual pollutant should be considered in pollutant buildup and washoff functions for simulating urban nonpoint source pollution when the total runoff volume is less than 30 mm. - Highlights: → An improved urban NPS model was developed. → It performs well in areas where storm events have great temporal variation. → Threshold of total runoff volume for ignoring residual pollutant was determined. - An improved urban NPS model was developed. Threshold of total runoff volume for ignoring residual pollutant was determined.

  20. The effect of different initial densities of nematode (Meloidogyne javanica) on the build-up of Pasteuria penetrans population.

    Science.gov (United States)

    Darban, Daim Ali; Pathan, Mumtaz Ali; Bhatti, Abdul Ghaffar; Maitelo, Sultan Ahmed

    2005-02-01

    Pasteuria penetrans will build-up faster where there is a high initial nematode density and can suppress root-knot nematode populations in the roots of tomato plants. The effect of different initial densities of nematode (Meloidogyne javanica) (150, 750, 1500, 3000) and P. penetrans infected females (F1, F3) densities (F0=control and AC=absolute control without nematode or P. penetrans inoculum) on the build-up of Pasteuria population was investigated over four crop cycles. Two major points of interest were highlighted. First, that within a confined soil volume, densities of P. penetrans can increase >100 times within 2 or 3 crop cycles. Second, from a relatively small amount of spore inoculum, infection of the host is very high. There were more infected females in the higher P. penetrans doses. The root growth data confirms the greater number of females in the controls particularly at the higher inoculum densities in the third and fourth crops. P. penetrans generally caused the fresh root weights to be higher than those in the control. P. penetrans has shown greater reduction of egg masses per plant at most densities. The effects of different initial densities of M. javanica and P. penetrans on the development of the pest and parasite populations were monitored. And no attempt was made to return the P. penetrans spores to the pots after each crop so the build-up in actual numbers of infected females and spores under natural conditions may be underestimated.

  1. The Influence of Seal Properties on Pressure Buildup and Leakage of Carbon Dioxide from Sequestration Reservoirs (Invited)

    Science.gov (United States)

    Benson, S. M.; Chabora, E.

    2009-12-01

    The transport properties of seals, namely permeability, relative permeability, and capillary pressure control both migration of carbon dioxide and brine through the seal. Only recently has the the importance of brine migration emerged as key issue in the environmental performance of carbon dioxide sequestration projects. In this study we use numerical simulation to show that brine migration through the seal can be either advantageous or deleterious to the environmental performance of a carbon dioxide sequestration project. Brine migration through the seal can lower the pressure buildup in the storage reservoir, thereby reducing the risk of leakage or geomechanical stresses on the seal. On the other hand, if the seal is penetrated by a permeable fault it can lead to focused flow up a fault, which could lead to brine migration into drinking water aquifers. We also show that as the carbon dioxide plume grows, brine flow undergoes a complex evolution from upward flow to downward flows driven by countercurrent migration of carbon dioxide and brine in the seal and capillary pressure gradients at the base of the seal. Finally, we discuss desirable attributes seals, taking into account both carbon dioxide and brine migration through the seal. In particular, identifying seals that provide an effective capillary barrier to block the flow of carbon dioxide while allowing some brine migration through the seal can help to control pressure buildup and allow more efficient utilization of a sequestration reservoir. This could be particularly important in those settings that may be limited by the maximum allowable pressure buildup.

  2. Forced-air warming design: evaluation of intake filtration, internal microbial buildup, and airborne-contamination emissions.

    Science.gov (United States)

    Reed, Mike; Kimberger, Oliver; McGovern, Paul D; Albrecht, Mark C

    2013-08-01

    Forced-air warming devices are effective for the prevention of surgical hypothermia. However, these devices intake nonsterile floor-level air, and it is unknown whether they have adequate filtration measures to prevent the internal buildup or emission of microbial contaminants. We rated the intake filtration efficiency of a popular current-generation forced-air warming device (Bair Hugger model 750, Arizant Healthcare) using a monodisperse sodium chloride aerosol in the laboratory. We further sampled 23 forced-air warming devices (same model) in daily hospital use for internal microbial buildup and airborne-contamination emissions via swabbing and particle counting. Laboratory testing found the intake filter to be 63.8% efficient. Swabbing detected microorganisms within 100% of the forced-air warming blowers sampled, with isolates of coagulase-negative staphylococci, mold, and micrococci identified. Particle counting showed 96% of forced-air warming blowers to be emitting significant levels of internally generated airborne contaminants out of the hose end. These findings highlight the need for upgraded intake filtration, preferably high-efficiency particulate air filtration (99.97% efficient), on current-generation forced-air warming devices to reduce contamination buildup and emission risks.

  3. The effect of build-up cap materials on the response of an ionization chamber to 60Co gamma rays

    International Nuclear Information System (INIS)

    Rocha, M.P.O.; Almeida, C.E. de

    1993-01-01

    Knowledge of the effect of wall and build-up cap materials on ionization chamber response is necessary to determine absorbed dose in a medium using a calibration factor based on exposure or kerma in air. Attenuation and scattering effects of 60 Co gamma rays in the ionization chamber wall and build-up cap, as well as their non-equivalence to air, were studied with an OFS ionization chamber (Delrin wall) and a set of build-up caps specially built for this purpose. Results for a specific material were plotted as functions of wall and cap total thickness, extrapolated to zero wall thickness, then corrected for mean centre of electron production in the wall (= 0.136 g cm -2 ). Correction factors for a specific thickness were analysed in relation to cap material, and to relative responses compared with values calculated by using AAPM, SEFM and IAEA formalisms for cap effects. A Monte Carlo calculation was performed to compare the experimental and theoretical values. Calculations showed an agreement within 0.1% with experimental values and a wall effect of approximately 1.6%. (Author)

  4. A comprehensive study of the energy absorption and exposure buildup factors of different bricks for gamma-rays shielding

    Directory of Open Access Journals (Sweden)

    M.I. Sayyed

    Full Text Available The present investigation has been performed on different bricks for the purpose of gamma-ray shielding. The values of the mass attenuation coefficient (µ/ρ, energy absorption buildup factor (EABF and exposure buildup factor (EBF were determined and utilized to assess the shielding effectiveness of the bricks under investigation. The mass attenuation coefficients of the selected bricks were calculated theoretically using WinXcom program and compared with MCNPX code. Good agreement between WinXcom and MCNPX results was observed. Furthermore, the EABF and EBF have been discussed as functions of the incident photon energy and penetration depth. It has been found that the EABF and EBF values are very large in the intermediate energy region. The steel slag showed good shielding properties, consequently, this brick is eco-friendly and feasible compared with other types of bricks used for construction. The results in this work should be useful in the construction of effectual shielding against hazardous gamma-rays. Keywords: Brick, Mass attenuation coefficient, Buildup factor, G-P fitting, Radiation shielding

  5. Evaluation of Geometric Progression (GP Buildup Factors using MCNP Codes (MCNP6.1 and MCNP5-1.60

    Directory of Open Access Journals (Sweden)

    Kim Kyung-O

    2016-01-01

    Full Text Available The gamma-ray buildup factors of three-dimensional point kernel code (QAD-CGGP are re-evaluated by using MCNP codes (MCNP6.1 and MCNPX5-1.60 and ENDF/B-VI.8 photoatomic data, which cover an energy range of 0.015–15 MeV and an iron thickness of 0.5–40 Mean Free Path (MFP. These new data are fitted to the Geometric Progression (GP fitting function and are then compared with ANS standard data equipped with QAD-CGGP. In addition, a simple benchmark calculation was performed to compare the QAD-CGGP results applied with new and existing buildup factors based on the MCNP codes. In the case of the buildup factors of low-energy gamma-rays, new data are evaluated to be about 5% higher than the existing data. In other cases, these new data present a similar trend based on the specific penetration depth, while existing data continuously increase beyond that depth. In a simple benchmark, the calculations using the existing data were slightly underestimated compared to the reference data at a deep penetration depth. On the other hand, the calculations with new data were stabilized with an increasing penetration depth, despite a slight overestimation at a shallow penetration depth.

  6. A One-Dimensional Particle-in-Cell Model of Plasma Build-Up in Vacuum Arcs

    CERN Document Server

    Timko, H; Kovermann, J; Taborelli, M; Nordlund, K; Descoeudres, A; Schneider, R; Calatroni, S; Matyash, K; Wuensch, W; Hansen, A; Grudiev, A

    2011-01-01

    Understanding the mechanism of plasma build-up in vacuum arcs is essential in many fields of physics. A one-dimensional particle-in-cell computer simulation model is presented, which models the plasma developing from a field emitter tip under electrical breakdown conditions, taking into account the relevant physical phenomena. As a starting point, only an external electric field and an initial enhancement factor of the tip are assumed. General requirements for plasma formation have been identified and formulated in terms of the initial local field and a critical neutral density. The dependence of plasma build-up on tip melting current, the evaporation rate of neutrals and external circuit time constant has been investigated for copper and simulations imply that arcing involves melting currents around 0.5-1 A/mu m(2),evaporation of neutrals to electron field emission ratios in the regime 0.01 - 0.05, plasma build-up timescales in the order of similar to 1 - 10 ns and two different regimes depending on initial ...

  7. Calculation of Buildup Factor for Gamma-ray Exposure in Two Layered Shields Made of Water and Lead

    International Nuclear Information System (INIS)

    Al-Saadi, A.H.

    2012-01-01

    The buildup factor for gamma ray exposure is most useful in calculations for biological protective shields.The buildup factors for gamma ray exposure were calculated in tow layered shields consist of water-lead and lead-water up to optical Thickness 20 mean free path (mfp) at gamma ray energies 1, 2 and 6MeV by using kalos's formula.The program has been designed to work at any atomic number of the attenuating medium, photon energy, slab thickness and and the arrangement of materials.The results obtained in this search leading to the buildup factor for gamma ray exposure at energies (1and2MeV) in lead-water were higher than the reverse case,while at energy 6 MeV the effect was opposite.The calculated data were parameterized by an empirical formula as a function of optical thickness of tow materials.The results obtained were in reasonable agreement with a previous work

  8. Scenario development methods and practice

    International Nuclear Information System (INIS)

    2001-01-01

    The safe management of radioactive waste is an essential aspect of all nuclear power programmes. Although a general consensus has been reached in OECD countries on the use of geological repositories for the disposal of high-level radioactive waste, analysis of the long-term safety of these repositories, using performance assessment and other tools, is required prior to implementation. The initial stage in developing a repository safety assessment is the identification of all factors that may be relevant to the long-term safety of the repository and their combination to form scenarios. This must be done in a systematic and transparent way in order to assure the regulatory authorities that nothing important has been forgotten. Scenario development has become the general term used to describe the collection and organisation of the scientific and technical information necessary to assess the long-term performance or safety of radioactive waste disposal systems. This includes the identification of the relevant features, events and processes (FEPs), the synthesis of broad models of scientific understanding, and the selection of cases to be calculated. Scenario development provides the overall framework in which the cases and their calculated consequences can be discussed, including biases or shortcomings due to omissions or lack of knowledge. The NEA Workshop on Scenario Development was organised in Madrid, in May 1999, with the objective of reviewing developments in scenario methodologies and applications in safety assessments since 1992. The outcome of this workshop is the subject of this book. It is a review of developments in scenario methodologies based on a large body of practical experience in safety assessments. It will be of interest to radioactive waste management experts as well as to other specialists involved in the development of scenario methodologies. (author)

  9. Transportation-Driven Mars Surface Operations Supporting an Evolvable Mars Campaign

    Science.gov (United States)

    Toups, Larry; Brown, Kendall; Hoffman, Stephen J.

    2015-01-01

    This paper describes the results of a study evaluating options for supporting a series of human missions to a single Mars surface destination. In this scenario the infrastructure emplaced during previous visits to this site is leveraged in following missions. The goal of this single site approach to Mars surface infrastructure is to enable "Steady State" operations by at least 4 crew for up to 500 sols at this site. These characteristics, along with the transportation system used to deliver crew and equipment to and from Mars, are collectively known as the Evolvable Mars Campaign (EMC). Information in this paper is presented in the sequence in which it was accomplished. First, a logical buildup sequence of surface infrastructure was developed to achieve the desired "Steady State" operations on the Mars surface. This was based on a concept of operations that met objectives of the EMC. Second, infrastructure capabilities were identified to carry out this concept of operations. Third, systems (in the form of conceptual elements) were identified to provide these capabilities. This included top-level mass, power and volume estimates for these elements. Fourth, the results were then used in analyses to evaluate three options (18t, 27t, and 40t landed mass) of Mars Lander delivery capability to the surface. Finally, Mars arrival mass estimates were generated based upon the entry, descent, and landing requirements for inclusion in separate assessments of in-space transportation capabilities for the EMC.

  10. Social Foundation of Scenario Planning

    DEFF Research Database (Denmark)

    Rowland, Nicholas James; Spaniol, Matthew Jon

    2017-01-01

    In this article, the authors establish that models of scenario planning typically involve a series of phases, stages, or steps that imply a sequenced (i.e., linear or chronological) process. Recursive models, in contrast, allow phases to repeat, thus, incorporating iteration. The authors acknowle......In this article, the authors establish that models of scenario planning typically involve a series of phases, stages, or steps that imply a sequenced (i.e., linear or chronological) process. Recursive models, in contrast, allow phases to repeat, thus, incorporating iteration. The authors...... from science and technology studies (STS) on knowledge production, the authors explain transition from one phase to the next and iteration between and within phases based on social negotiation. To this end, the authors examine the interplay between the “scenario development” phase and the “scenario use......” phase of a planning process with a non-governmental organization in Denmark. The upshot for facilitators is practical insight into how transition between phases and phase iteration in scenario planning can be identified, leveraged, and, thus, managed. The upshot for scholars is a related insight...

  11. New reactors concepts and scenarios

    International Nuclear Information System (INIS)

    Gandini, A.

    2001-01-01

    In recent years an increasing interest is observed with respect to subcritical, accelerator driven systems (ADS), for their possible role in perspective future nuclear energy scenarios, as actinide (Pu and MA) incinerators, and/or claimed energy plants with potential enhanced safety characteristics. Important research programs are devoted to the various related fields of research. Extensive studies on the ADS behavior under incidental conditions are in particular made, for verifying their claimed advantage, under the safety point of view, with respect to the corresponding critical reactors. Corresponding medium and long range scenarios are being studied to cope with a number of concerns associated with the safety (power excursions. residual heat risk), as well as with the fuel flow (criticality accidents, fuel diversion, radiological risk, proliferation). In the present work we shall try to review current lines of research in this field, and comment on possible scenarios so far envisaged. (author)

  12. Scenarios of future energy intensities

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    In this chapter, the authors present scenarios of potential change in energy intensities in the OECD countries and in the Soviet Union. These scenarios are meant to illustrate how intensities might evolve over the next 20 years given different conditions with respect to energy prices, energy-efficiency policies, and other key factors. Changes in intensity will also be affected by the rates of growth and stock turnover in each sector. They have not tried to forecast how activity levels and structure will evolve. However, the OECD scenarios assume a world in which GDP averages growth in the 2-3%/year range, with some differences among countries. For the Soviet Union, the degree and pace of intensity decline will be highly dependent on the success of the transition to a market economy; each scenario explicitly envisions a different degree of success. They have not constructed comparable scenarios for the developing countries. The scenarios presented in this chapter do not predict what will happen in the future. They believe, however, that they illustrate a plausible set of outcomes if energy prices, policies, programs, and other factors evolve as described in each case. With higher energy prices and vigorous policies and programs, intensities in the OECD countries in 2010 could be nearly 50% less on average than the level where trends seem to be point. In the former Soviet Union, a combination of rapid, successful economic reform and extra effort to improve energy efficiency might result in average intensity being nearly 40% less than in a slow reform case. And in the LDCs, a mixture of sound policies, programs, and energy pricing reform could also lead to intensities being far lower than they would be otherwise. 8 refs., 10 figs., 1 tab

  13. NEC-2020 emission reduction scenarios

    DEFF Research Database (Denmark)

    Slentø, Erik; Nielsen, Ole-Kenneth; Hoffmann, Leif

    The upcoming NEC-2020 EU directive sets up emission ceilings for NOX, SO2, NH3, NMVOC and PM in order to meet the environmental exposure targets of the Thematic Strategy. This report contains an assessment of intermediary emission reduction scenarios for Denmark, computed by the GAINS model 2007,......, which serves as the basis for the pending negotiations in EU. The assessment is brought up to date by including a brief evaluation of the new reduction scenarios published in 2008, founding the European Commission NEC-2020 directive proposal....

  14. Investigation of human teeth with respect to the photon interaction, energy absorption and buildup factor

    Energy Technology Data Exchange (ETDEWEB)

    Kurudirek, Murat, E-mail: mkurudirek@gmail.co [Faculty of Science, Department of Physics, Ataturk University, 25240 Erzurum (Turkey); Topcuoglu, Sinan [Faculty of Dentistry, Department of Endodontic, Ataturk University, 25240 Erzurum (Turkey)

    2011-05-15

    The effective atomic numbers and electron densities of human teeth have been calculated for total photon interaction (Z{sub PI{sub e{sub f{sub f}}}},Ne{sub PI{sub e{sub f{sub f}}}}) and photon energy absorption (Z{sub PEA{sub e{sub f{sub f}}}},Z{sub RW{sub e{sub f{sub f}}}}Ne{sub PEA{sub e{sub f{sub f}}}}) in the energy region 1 keV-20 MeV. Besides, the energy absorption (EABF) and exposure (EBF) buildup factors have been calculated for these samples by using the geometric progression fitting approximation in the energy region 0.015-15 MeV up to 40 mfp (mean free path). Wherever possible the results were compared with experiment. Effective atomic numbers (Z{sub PI{sub e{sub f{sub f}}}}) of human teeth were calculated using different methods. Discrepancies were noted in Z{sub PI{sub e{sub f{sub f}}}} between the direct and interpolation methods in the low and high energy regions where absorption processes dominate while good agreement was observed in intermediate energy region where Compton scattering dominates. Significant variations up to 22% were observed between Z{sub PI{sub e{sub f{sub f}}}} and Z{sub PEA{sub e{sub f{sub f}}}} in the energy region 30-150 keV which is the used energy range in dental cone beam computed tomography (CBCT) X-ray machines. The Z{sub eff} values of human teeth were found to relatively vary within 1% if different laser treatments are applied. In this variation, the Er:YAG laser treated samples were found to be less effected than Nd:YAG laser treated ones when compared with control group. Relative differences between EABF and EBF were found to be significantly high in the energy region 60 keV-1 MeV even though they have similar variations with respect to the different parameters viz. photon energy, penetration depth.

  15. Influence of Pressure Build-Up Time of Compression Chamber on Improving the Operation Frequency of a Single-Piston Hydraulic Free-Piston Engine

    Directory of Open Access Journals (Sweden)

    Hai-bo Xie

    2013-01-01

    Full Text Available A single-piston hydraulic free-piston engine with a two-cylinder four-stroke diesel engine as its driver is introduced. It takes the free-piston assembly a certain time to move after the pressure in the compression chamber starts to increase. The time difference between the pressure increasing and the piston starting to move is defined as the pressure build-up time. The characteristics of the pressure build-up time and its influence on the performance of the free-piston engine are introduced and analyzed. Based on the basic law of dynamics of the free-piston assembly, the parameters which influence the pressure build-up time are analyzed. And then improvement and optimization are proposed to shorten the pressure build-up time.

  16. Aphanitic buildup from the onset of the Mulde Event (Homerian, middle Silurian at Whitman's Hill, Herefordshire, UK: ultrastructural insights into proposed microbial fabrics

    Directory of Open Access Journals (Sweden)

    Jan-Filip Päßler

    2014-12-01

    Full Text Available A microbial origin has been proposed for matrix-supported, low-diversity buildups reported from different palaeocontinents during the onset of the Mulde positive carbon isotope excursion. We have investigated a small aphanitic buildup from the Lower Quarried Limestone Member of the Much Wenlock Limestone Formation, exposed at Whitman's Hill (Herefordshire, corresponding to the central part of the Midland Platform (UK. Up to 50% of the rock volume in this buildup consists of mottled micrite. The SEM studies revealed that the micrite is largely detrital and does not show features characteristic of calcareous cyanobacteria or leiolites. The aphanitic character of the buildup is suggested to be controlled by the depositional rate, and the widespread occurrence of matrix-supported reefs in this interval to be driven by a mid-Homerian rapid eustatic transgression.

  17. Attributes Of Quality Scenarios/Scenario Sets Used In Software Requirements Elicitation

    National Research Council Canada - National Science Library

    Braun, Kimberly

    1997-01-01

    .... This thesis examines scenarios used in software requirements elicitation. Many different definitions, formats, and ideas exist on scenarios, but no thorough work has been done on what makes a good, quality scenario and scenario set...

  18. Program Analysis Scenarios in Rascal

    NARCIS (Netherlands)

    M.A. Hills (Mark); P. Klint (Paul); J.J. Vinju (Jurgen); F. Durán

    2012-01-01

    textabstractRascal is a meta programming language focused on the implementation of domain-specific languages and on the rapid construction of tools for software analysis and software transformation. In this paper we focus on the use of Rascal for software analysis. We illustrate a range of scenarios

  19. Scenario Based Network Infrastructure Planning

    DEFF Research Database (Denmark)

    Knudsen, Thomas Phillip; Pedersen, Jens Myrup; Madsen, Ole Brun

    2005-01-01

    The paper presents a method for IT infrastructure planning that take into account very long term developments in usages. The method creates a scenario for a final, time independent stage in the planning process. The method abstracts relevant modelling factors from available information...

  20. Multiscale scenarios for nature futures

    CSIR Research Space (South Africa)

    Rosa, IMD

    2017-09-01

    Full Text Available & Evolution, vol. 1: 1416-1419 Multiscale scenarios for nature futures Rosa IMD Pereira HM Ferrier S Alkemade R Acosta LA Akcakaya HR den Belder E Fazel AM Fujimori S Sitas NE ABSTRACT: Targets for human development are increasingly...

  1. Shell energy scenarios to 2050

    International Nuclear Information System (INIS)

    2008-01-01

    Shell developed two scenarios that describe alternative ways the energy future may develop. In the first scenario (Scramble) policymakers pay little attention to more efficient energy use until supplies are tight. Likewise, greenhouse gas emissions are not seriously addressed until there are major climate shocks. In the second scenario (Blueprints) growing local actions begin to address the challenges of economic development, energy security and environmental pollution. A price is applied to a critical mass of emissions giving a huge stimulus to the development of clean energy technologies, such as carbon dioxide capture and storage, and energy efficiency measures. The result is far lower carbon dioxide emissions. Both these scenarios can help Shell to test their strategy against a range of possible developments over the long-term. However, according to Shell, the Blueprints' outcomes offer the best hope for a sustainable future, whether or not they arise exactly in the way described. However, with the right combination of policy, technology and commitment from governments, industry and society globally, Shell believes it can be realized. But achieving the targets will not be easy, and time is short. Clear thinking, huge investment, and effective leadership are required

  2. Evaluation of pressure response in the Los Alamos controlled air incinerator during three incident scenarios

    International Nuclear Information System (INIS)

    Vavruska, J.S.; Elsberry, K.; Thompson, T.K.; Pendergrass, J.A.

    1996-01-01

    The Los Alamos Controlled Air Incinerator (CAI) is a system designed to accept radioactive mixed waste containing alpha-emitting radionuclides. A mathematical model was developed to predict the pressure response throughout the offgas treatment system of the CAI during three hypothetical incident scenarios. The scenarios examined included: (1) loss of burner flame and failure of the flame safeguard system with subsequent reignition of fuel gas in the primary chamber, (2) pyrolytic gas buildup from a waste package due to loss of induced draft and subsequent restoration of induced draft, and (3) accidental charging of propellant spray cans in a solid waste package to the primary chamber during a normal feed cycle. For each of the three scenarios, the finite element computer model was able to determine the transient pressure surge and decay response throughout the system. Of particular interest were the maximum absolute pressures attainable at critical points in the system as well as maximum differential pressures across the high efficiency particulate air (HEPA) filters. Modeling results indicated that all three of the scenarios resulted in maximum HEPA filter differential pressures well below the maximum allowable levels

  3. Does extreme precipitation intensity depend on the emissions scenario?

    Science.gov (United States)

    Pendergrass, Angeline; Lehner, Flavio; Sanderson, Benjamin; Xu, Yangyang

    2016-04-01

    The rate of increase of global-mean precipitation per degree surface temperature increase differs for greenhouse gas and aerosol forcings, and therefore depends on the change in composition of the emissions scenario used to drive climate model simulations for the remainder of the century. We investigate whether or not this is also the case for extreme precipitation simulated by a multi-model ensemble driven by four realistic emissions scenarios. In most models, the rate of increase of maximum annual daily rainfall per degree global warming in the multi-model ensemble is statistically indistinguishable across the four scenarios, whether this extreme precipitation is calculated globally, over all land, or over extra-tropical land. These results indicate that, in most models, extreme precipitation depends on the total amount of warming and does not depend on emissions scenario, in contrast to mean precipitation.

  4. Attack surfaces

    DEFF Research Database (Denmark)

    Gruschka, Nils; Jensen, Meiko

    2010-01-01

    The new paradigm of cloud computing poses severe security risks to its adopters. In order to cope with these risks, appropriate taxonomies and classification criteria for attacks on cloud computing are required. In this work-in-progress paper we present one such taxonomy based on the notion...... of attack surfaces of the cloud computing scenario participants....

  5. The Distinct Build-Up Of Dense And Normal Massive Passive Galaxies In Vipers

    Science.gov (United States)

    Gargiulo, Adriana; Vipers Team

    2017-06-01

    At fixed stellar mass, the population of passive galaxies has increased its mean effective radius by a factor 5 in the last 10 Gyr, decreasing its mean stellar mass density (S = Mstar/(2πRe 2 ) by a factor >> 10. Whether this increase in is mainly due to the size-growth of individual galaxies through dry mergers, or to the fact that newly quenched galaxies have a larger size, is still matter of debate. A promising approach to shed light on this issue is to investigate the evolution of the number density of passive galaxies as a function of their mass density. In this context, massive (Mstar >10^11 Msun) passive galaxies are the most intriguing systems to study, since, in a hierarchical scenario, they are expected to accrete their stellar mass mainly by mergers. The wide area (˜ 16 sq. deg) and high sampling rate (˜ 40%) of the spectroscopic survey VIPERS allowed us to collect a sample of ˜ 2000 passive massive galaxies over the redshift range 0.5 passive galaxies as function both of redshift and mass density. This information, combined with the evolution of the number density allowed us to put constraints on the mass accretion scenarios of passive galaxies. In this talk I will present our results and conclusions and how they depend on the environment in which the galaxies reside.

  6. Probing the Build-Up of Quiescent Galaxies at z>3

    Science.gov (United States)

    Finkelstein, Steven

    We propose to perform the most robust investigation to date into the evolution of massive quiescent and star-forming galaxies at z > 3, at a time when the universe was less than two billion years old. The build-up of quiescent galaxies in particular is poorly understood, primarily due to large Poisson and cosmic variance issues that have plagued previous studies that probed small volumes, leading to a disagreement on the quiescent fraction by a factor of >3 in the literature. Our proposed work is only now possible due to a new legacy survey led by our team: the Spitzer-HETDEX Exploratory Large Area Survey (SHELA), which is imaging a 23 deg^2 area of the sky at optical, and near, mid and far-infrared, and X-ray wavelengths. In particular, the wide area coverage of the Spitzer/IRAC data allows us to be sensitive to massive galaxies at very high redshifts, the Herschel data allows us to rule out lower-redshift counterparts, and the XMM-Newton data allows us to remove quasar contaminants from our sample. This survey covers a volume >14X that of the largest previous survey for quiescent galaxies at z=3.5, and ~6X larger than that of the largest previous survey for star-forming galaxies at z=4. All of these data exist in the region soon to be observed by the Hobby Eberly Telescope Dark Energy Experiment (HETDEX), which will provide high-precision measures of halo masses and local density at z~3. Using this exquisite multi-wavelength dataset, we will measure the abundance of massive quiescent galaxies at z ~ 3-5, and, combining with measures of the halo masses and environment, compare properties of quiescent galaxies to star-forming galaxies to investigate the physical cause behind the quenching. We will also investigate the onset of quenching in star-forming galaxies in two ways, first by studying the relation between star formation rate and stellar mass, to search for a break in the typically-linear relation at high masses, and second by constraining the feedback

  7. Simulation of Electron-Cloud Build-Up for the Cold Arcs of the LHC and Comparison with Measured Data

    CERN Document Server

    Maury Cuna, H; Rumolo, G; Tavian, L; Zimmermann, F

    2011-01-01

    The electron cloud generated by synchrotron radiation or residual gas ionization is a concern for LHC operation and performance. We report the results of simulations studies which examine the electron cloud build-up, at injection energy, 3.5 TeV for various operation parameters. In particular, we determine the value of the secondary emission yield corresponding to the multipacting threshold, and investigate the electron density, and heat as a function of bunch intensity for dipoles and field-free regions. We also include a comparison between simulations results and measured heat-load data from the LHC scrubbing runs in 2011.

  8. Component build-up method for engineering analysis of missiles at low-to-high angles of attack

    Science.gov (United States)

    Hemsch, Michael J.

    1992-01-01

    Methods are presented for estimating the component build-up terms, with the exception of zero-lift drag, for missile airframes in steady flow and at arbitrary angles of attack and bank. The underlying and unifying bases of all these efforts are slender-body theory and its nonlinear extensions through the equivalent angle-of-attack concept. Emphasis is placed on the forces and moments which act on each of the fins, so that control cross-coupling effects as well as longitudinal and lateral-directional effects can be determined.

  9. Base case and perturbation scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Edmunds, T

    1998-10-01

    This report describes fourteen energy factors that could affect electricity markets in the future (demand, process, source mix, etc.). These fourteen factors are believed to have the most influence on the State's energy environment. A base case, or most probable, characterization is given for each of these fourteen factors over a twenty year time horizon. The base case characterization is derived from quantitative and qualitative information provided by State of California government agencies, where possible. Federal government databases are nsed where needed to supplement the California data. It is envisioned that a initial selection of issue areas will be based upon an evaluation of them under base case conditions. For most of the fourteen factors, the report identities possible perturbations from base case values or assumptions that may be used to construct additional scenarios. Only those perturbations that are plausible and would have a significant effect on energy markets are included in the table. The fourteen factors and potential perturbations of the factors are listed in Table 1.1. These perturbations can be combined to generate internally consist.ent. combinations of perturbations relative to the base case. For example, a low natural gas price perturbation should be combined with a high natural gas demand perturbation. The factor perturbations are based upon alternative quantitative forecasts provided by other institutions (the Department of Energy - Energy Information Administration in some cases), changes in assumptions that drive the quantitative forecasts, or changes in assumptions about the structure of the California energy markets. The perturbations are intended to be used for a qualitative reexamination of issue areas after an initial evaluation under the base case. The perturbation information would be used as a "tiebreaker;" to make decisions regarding those issue areas that were marginally accepted or rejected under the base case. Hf a

  10. Comparing long term energy scenarios

    International Nuclear Information System (INIS)

    Cumo, M.; Simbolotti, G.

    2001-01-01

    Major projection studies by international organizations and senior analysts have been compared with reference to individual key parameters (population, energy demand/supply, resources, technology, emissions and global warming) to understand trends and implications of the different scenarios. Then, looking at the long term (i.e., 2050 and beyond), parameters and trends have been compared together to understand and quantify whether and when possible crisis or market turbulence might occur due to shortage of resources or environmental problems [it

  11. Global energy context: future scenarios

    International Nuclear Information System (INIS)

    Beretta, Gian Paolo

    2006-01-01

    After a brief analysis of the history of global energy consumption, this paper discusses a plausible scenario of energy needs and related carbon emissions for the rest of the century. The global outlook and the probable evolution of several factors that impact on energy policy considerations - even on the local scale - demonstrate the great complexity and planetary dimension of the problems, as well as the almost certain sterility of out-of-context domestic energy-policy measures [it

  12. Advanced scenarios for ITER operation

    Energy Technology Data Exchange (ETDEWEB)

    Sips, A.C.C. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany)

    2004-07-01

    In thermonuclear fusion research using magnetic confinement, the tokamak is the leading candidate for achieving conditions required for a reactor. An international experiment, ITER is proposed as the next essential and critical step on the path to demonstrating the scientific and technological feasibility of fusion energy. ITER is to produce and study plasmas dominated by self heating. This would give unique opportunities to explore, in reactor relevant conditions, the physics of {alpha}-particle heating, plasma turbulence and turbulent transport, stability limits to the plasma pressure and exhaust of power and particles. Important new results obtained in experiments, theory and modelling, enable an improved understanding of the physical processes occurring in tokamak plasmas and give enhanced confidence in ITER achieving its goals. In particular, progress has been made in research to raise the performance of tokamaks, aimed to extend the discharge pulse length towards steady-state operation (advanced scenarios). Standard tokamak discharges have a current density increasing monotonically towards the centre of the plasma. Advanced scenarios on the other hand use a modified current density profile. Different advanced scenarios range from (i) plasmas that sustain a central region with a flat current density profile (zero magnetic shear), capable of operating stationary at high plasma pressure, to (ii) discharges with an off axis maximum of the current density profile (reversed magnetic shear in the core), able to form internal transport barriers, to increase the confinement of the plasma. The physics of advanced tokamak discharges is described, together with an overview of recent results from different tokamak experiments. International collaboration between experiments aims to provide a better understanding, control and optimisation of these plasmas. The ability to explore advanced scenarios in ITER is very desirable, in order to verify the result obtained in

  13. Underground infrastructure damage for a Chicago scenario

    Energy Technology Data Exchange (ETDEWEB)

    Dey, Thomas N [Los Alamos National Laboratory; Bos, Rabdall J [Los Alamos National Laboratory

    2011-01-25

    Estimating effects due to an urban IND (improvised nuclear device) on underground structures and underground utilities is a challenging task. Nuclear effects tests performed at the Nevada Test Site (NTS) during the era of nuclear weapons testing provides much information on how underground military structures respond. Transferring this knowledge to answer questions about the urban civilian environment is needed to help plan responses to IND scenarios. Explosions just above the ground surface can only couple a small fraction of the blast energy into an underground shock. The various forms of nuclear radiation have limited penetration into the ground. While the shock transmitted into the ground carries only a small fraction of the blast energy, peak stresses are generally higher and peak ground displacement is lower than in the air blast. While underground military structures are often designed to resist stresses substantially higher than due to the overlying rocks and soils (overburden), civilian structures such as subways and tunnels would generally only need to resist overburden conditions with a suitable safety factor. Just as we expect the buildings themselves to channel and shield air blast above ground, basements and other underground openings as well as changes of geology will channel and shield the underground shock wave. While a weaker shock is expected in an urban environment, small displacements on very close-by faults, and more likely, soils being displaced past building foundations where utility lines enter could readily damaged or disable these services. Immediately near an explosion, the blast can 'liquefy' a saturated soil creating a quicksand-like condition for a period of time. We extrapolate the nuclear effects experience to a Chicago-based scenario. We consider the TARP (Tunnel and Reservoir Project) and subway system and the underground lifeline (electric, gas, water, etc) system and provide guidance for planning this scenario.

  14. Scenarios for the LHC Upgrade

    CERN Document Server

    Scandale, Walter

    2008-01-01

    The projected lifetime of the LHC low-beta quadrupoles, the evolution of the statistical error halving time, and the physics potential all call for an LHC luminosity upgrade by the middle of the coming decade. In the framework of the CARE-HHH network three principal scenarios have been developed for increasing the LHC peak luminosity by more than a factor of 10, to values above 1035 cm−2s−1. All scenarios imply a rebuilding of the high-luminosity interaction regions (IRs) in combination with a consistent change of beam parameters. However, their respective features, bunch structures, IR layouts, merits and challenges, and luminosity variation with β∗ differ substantially. In all scenarios luminosity leveling during a store would be advantageous for the physics experiments. An injector upgrade must complement the upgrade measures in the LHC proper in order to provide the beam intensity and brightness needed as well as to reduce the LHC turnaround time for higher integrated luminosity.

  15. Simulating geometrically complex blast scenarios

    Directory of Open Access Journals (Sweden)

    Ian G. Cullis

    2016-04-01

    Full Text Available The effects of blast waves generated by energetic and non-energetic sources are of continuing interest to the ballistics research community. Modern conflicts are increasingly characterised by asymmetric urban warfare, with improvised explosive devices (IEDs often playing a dominant role on the one hand and an armed forces requirement for minimal collateral effects from their weapons on the other. These problems are characterised by disparate length- and time-scales and may also be governed by complex physics. There is thus an increasing need to be able to rapidly assess and accurately predict the effects of energetic blast in topologically complex scenarios. To this end, this paper presents a new QinetiQ-developed advanced computational package called EAGLE-Blast, which is capable of accurately resolving the generation, propagation and interaction of blast waves around geometrically complex shapes such as vehicles and buildings. After a brief description of the numerical methodology, various blast scenario simulations are described and the results compared with experimental data to demonstrate the validation of the scheme and its ability to describe these complex scenarios accurately and efficiently. The paper concludes with a brief discussion on the use of the code in supporting the development of algorithms for fast running engineering models.

  16. Scenarios and Strategies for Africa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-11-15

    In 2011, IRENA will start developing scenarios and strategies for Africa. This is a pilot study for a project that will ultimately encompass the whole world. The selection of Africa first indicates the priority that the IRENA work programme places on the continent. In the framework of the 2011 IRENA work programme, the analysis of scenarios and strategies will feed into the renewables readiness assessment, which will assess policy priorities and best practices in renewable energy policy-making. This, in turn, will be the basis for financing investment and capacity building activities. Energy policy advice must consider issues, such as the structure of energy supply and demand, the past and future energy trends, renewable energy resources, energy economics and technology access. Scenarios and strategies are key tools for such an analysis. Regional and national differences must be considered and individual sectors and end-use categories further analysed. These include power generation, cooking, heating, industrial process heat, and transport. Urban and rural solutions will be dealt with separately, as well as centralised and decentralised solutions. The analysis will cover issues, such as potentials, technology, supply chains and investment needs.

  17. Study on Earth Radiation Budget mission scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Dlhopolsky, R; Hollmann, R; Mueller, J; Stuhlmann, R [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Atmosphaerenphysik

    1998-12-31

    The goal of this study is to study optimized satellite configurations for observation of the radiation balance of the earth. We present a literature survey of earth radiation budget missions and instruments. We develop a parametric tool to simulate realistic multiple satellite mission scenarios. This tool is a modular computer program which models satellite orbits and scanning operation. We use Meteosat data sampled at three hour intervals as a database to simulate atmospheric scenes. Input variables are satellite equatorial crossing time and instrument characteristics. Regional, zonal and global monthly averages of shortwave and longwave fluxes for an ideal observing system and several realistic satellite scenarios are produced. Comparisons show that the three satellite combinations which have equatorial crossing times at midmorning, noon and midafternoon provide the best shortwave monitoring. Crossing times near sunrise and sunset should be avoided for the shortwave. Longwave diurnal models are necessary over and surfaces and cloudy regions, if there are only two measurements made during daylight hours. We have found in the shortwave inversion comparison that at least 15% of the monthly regional errors can be attributed to the shortwave anisotropic models used. (orig.) 68 refs.

  18. Study on Earth Radiation Budget mission scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Dlhopolsky, R.; Hollmann, R.; Mueller, J.; Stuhlmann, R. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Atmosphaerenphysik

    1997-12-31

    The goal of this study is to study optimized satellite configurations for observation of the radiation balance of the earth. We present a literature survey of earth radiation budget missions and instruments. We develop a parametric tool to simulate realistic multiple satellite mission scenarios. This tool is a modular computer program which models satellite orbits and scanning operation. We use Meteosat data sampled at three hour intervals as a database to simulate atmospheric scenes. Input variables are satellite equatorial crossing time and instrument characteristics. Regional, zonal and global monthly averages of shortwave and longwave fluxes for an ideal observing system and several realistic satellite scenarios are produced. Comparisons show that the three satellite combinations which have equatorial crossing times at midmorning, noon and midafternoon provide the best shortwave monitoring. Crossing times near sunrise and sunset should be avoided for the shortwave. Longwave diurnal models are necessary over and surfaces and cloudy regions, if there are only two measurements made during daylight hours. We have found in the shortwave inversion comparison that at least 15% of the monthly regional errors can be attributed to the shortwave anisotropic models used. (orig.) 68 refs.

  19. Environmental impact of PV cell waste scenario.

    Science.gov (United States)

    Bogacka, M; Pikoń, K; Landrat, M

    2017-12-01

    Rapid growth of the volume of waste from PV cells is expected in the following years. The problem of its utilization seems to be the most important issue for future waste management systems. The environmental impacts of the PV recycling scenario are presented in the manuscript. The analysis is based on the LCA approach and the average data available in specialized databases for silicon standard PV cell is used. The functional unit includes parameters like: efficiency, composition, surface area. The discussion on the environmental impact change due to the location of the PV production and waste processing plants is presented in the manuscript. Additionally, the discussion on the environmental effect of substituting different energy resources with PV cells is presented in the manuscript. The analysis of the PV cell life cycle scenario presented in the article was performed using the SIMA PRO software and data from Ecoinvent 3.0 database together with additional data obtained from other sources. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. The HayWired Earthquake Scenario

    Science.gov (United States)

    Detweiler, Shane T.; Wein, Anne M.

    2017-04-24

    ForewordThe 1906 Great San Francisco earthquake (magnitude 7.8) and the 1989 Loma Prieta earthquake (magnitude 6.9) each motivated residents of the San Francisco Bay region to build countermeasures to earthquakes into the fabric of the region. Since Loma Prieta, bay-region communities, governments, and utilities have invested tens of billions of dollars in seismic upgrades and retrofits and replacements of older buildings and infrastructure. Innovation and state-of-the-art engineering, informed by science, including novel seismic-hazard assessments, have been applied to the challenge of increasing seismic resilience throughout the bay region. However, as long as people live and work in seismically vulnerable buildings or rely on seismically vulnerable transportation and utilities, more work remains to be done.With that in mind, the U.S. Geological Survey (USGS) and its partners developed the HayWired scenario as a tool to enable further actions that can change the outcome when the next major earthquake strikes. By illuminating the likely impacts to the present-day built environment, well-constructed scenarios can and have spurred officials and citizens to take steps that change the outcomes the scenario describes, whether used to guide more realistic response and recovery exercises or to launch mitigation measures that will reduce future risk.The HayWired scenario is the latest in a series of like-minded efforts to bring a special focus onto the impacts that could occur when the Hayward Fault again ruptures through the east side of the San Francisco Bay region as it last did in 1868. Cities in the east bay along the Richmond, Oakland, and Fremont corridor would be hit hardest by earthquake ground shaking, surface fault rupture, aftershocks, and fault afterslip, but the impacts would reach throughout the bay region and far beyond. The HayWired scenario name reflects our increased reliance on the Internet and telecommunications and also alludes to the

  1. Water chemistry and radiation buildup at the Commonwealth Edison Company LaSalle-1 BWR. Final report

    International Nuclear Information System (INIS)

    Earls, C.E.; Blok, J.

    1986-09-01

    This report presents the results of a comprehensive study of the water quality and radiation buildup at the LaSalle County Unit 2 boiling warer reactor (BWR). The purpose of the study was to determine the effect of corrosion product inputs from the forward pumped heater drains on overall water quality. Since the drains are pumped into the feedwater line without filtration or demineralization, corrosion products in these streams will directly add to the impurity levels of the final feedwater. At LaSalle, the forward pumped heater drains contributed less to the feedwater impurities, on average, than the effluent of the condensate demineralizer. The feedwater quality at LaSalle was generally in the ''acceptable'' range. Nevertheless, significant water chemistry improvements, especially in reducing the corrosion product spikes associated with power or flow transients, is highly desirable for this plant. Such improvements should begin with a more consistent quality of demineralizer operation. Quantitative gamma scans of the primary system piping at LaSalle 2 were carried out in the course of the water chemistry study. Although the cumulative operational exposure of the plant was relatively limited at the time this study was carried out, the radiation buildup rate did appear to be rapid (in fact, among the most rapid) compared to other similar BWRs

  2. Desorption of SVOCs from Heated Surfaces in the Form of Ultrafine Particles

    DEFF Research Database (Denmark)

    Wallace, Lance A.; Ott, Wayne R.; Weschler, Charles J.

    2017-01-01

    of the accumulation rate of SVOCs on surfaces were similar to those in studies of organic film buildup on indoor windows. Transfer of skin oils by touching the glass or foil surfaces, or after washing the glass surface with detergent and bare hands, was also observed, with measured particle production comparable...

  3. Occult hepatitis B infection: an evolutionary scenario

    Directory of Open Access Journals (Sweden)

    Lukashov Vladimir V

    2008-12-01

    Full Text Available Abstract Background Occult or latent hepatitis B virus (HBV infection is defined as infection with detectable HBV DNA and undetectable surface antigen (HBsAg in patients' blood. The cause of an overt HBV infection becoming an occult one is unknown. To gain insight into the mechanism of the development of occult infection, we compared the full-length HBV genome from a blood donor carrying an occult infection (d4 with global genotype D genomes. Results The phylogenetic analysis of polymerase, core and X protein sequences did not distinguish d4 from other genotype D strains. Yet, d4 surface protein formed the evolutionary outgroup relative to all other genotype D strains. Its evolutionary branch was the only one where accumulation of substitutions suggests positive selection (dN/dS = 1.3787. Many of these substitutiions accumulated specifically in regions encoding the core/surface protein interface, as revealed in a 3D-modeled protein complex. We identified a novel RNA splicing event (deleting nucleotides 2986-202 that abolishes surface protein gene expression without affecting polymerase, core and X-protein related functions. Genotype D strains differ in their ability to perform this 2986-202 splicing. Strains prone to 2986-202 splicing constitute a separate clade in a phylogenetic tree of genotype D HBVs. A single substitution (G173T that is associated with clade membership alters the local RNA secondary structure and is proposed to affect splicing efficiency at the 202 acceptor site. Conclusion We propose an evolutionary scenario for occult HBV infection, in which 2986-202 splicing generates intracellular virus particles devoid of surface protein, which subsequently accumulates mutations due to relaxation of coding constraints. Such viruses are deficient of autonomous propagation and cannot leave the host cell until it is lysed.

  4. Scenarios for the future; Framtidsscenarier

    Energy Technology Data Exchange (ETDEWEB)

    Haegermark, H; Bergmark, M

    1995-06-01

    This project aims primarily to give a basis for the joint R and D program for the Swedish electric utility industry, in the form of pictures of the future up to 2020. The work was performed during four seminars in a group of managers and R and D planners. The four scenarios differ mainly in the assumptions of high or low economic growth and on market or political rule. Assumptions on essential uncertainties about the future have been combined in a consistent manner, e.g. on the structure of the utility industry, the role of nuclear power, the importance of the greenhouse gas issue, the influence of new technology developments and on changes of values in society. Certain other development appear in all scenarios, e.g. the impact of information technology throughout society, the internationalization of business in general and industrial production in particular, considerations for the environment and care for natural resources. The four scenarios are: `Technology on the throne` (market rule/high growth); `Intense competition` (market rule/low growth); `Monopoly takes over` (political rule/high growth); and `Green local society` (political rule/low growth). Some of the important factors pointed out by the study are: Increased customer mobility between regions and countries; The impact of information technology; Societal value changes; Sustainable development as an important driving force; Structure of the utility industry. Diversifying into new services. New players; Access to knowledge and competence; Ways for handling the greenhouse gas problem; Preparedness for nuclear power phase-out. 12 figs, 6 tabs

  5. Spent fuel receipt scenarios study

    International Nuclear Information System (INIS)

    Ballou, L.B.; Montan, D.N.; Revelli, M.A.

    1990-09-01

    This study reports on the results of an assignment from the DOE Office of Civilian Radioactive Waste Management to evaluate of the effects of different scenarios for receipt of spent fuel on the potential performance of the waste packages in the proposed Yucca Mountain high-level waste repository. The initial evaluations were performed and an interim letter report was prepared during the fall of 1988. Subsequently, the scope of work was expanded and additional analyses were conducted in 1989. This report combines the results of the two phases of the activity. This study is a part of a broader effort to investigate the options available to the DOE and the nuclear utilities for selection of spent fuel for acceptance into the Federal Waste Management System for disposal. Each major element of the system has evaluated the effects of various options on its own operations, with the objective of providing the basis for performing system-wide trade-offs and determining an optimum acceptance scenario. Therefore, this study considers different scenarios for receipt of spent fuel by the repository only from the narrow perspective of their effect on the very-near-field temperatures in the repository following permanent closure. This report is organized into three main sections. The balance of this section is devoted to a statement of the study objective, a summary of the assumptions. The second section of the report contains a discussion of the major elements of the study. The third section summarizes the results of the study and draws some conclusions from them. The appendices include copies of the waste acceptance schedule and the existing and projected spent fuel inventory that were used in the study. 10 refs., 27 figs

  6. Comparing recent uranium supply scenarios

    International Nuclear Information System (INIS)

    Arnold, N.; Gufler, K.

    2014-01-01

    For more than one decade – even after the Fukushima accidents - an increase in global nuclear energy generation capacity is widely expected. At the same time a variety of uranium supply scenarios were published by industry, academics or international organizations, drawing different pictures of future uranium supply. They were created with the background of a uranium market facing several challenges. First an excursion in the uranium market price, in 2007, then reduced nuclear growth expectations after 2011, at least in non-Asian countries, also implying considerable changes to the supply side. For this publication a meta-study was carried out identifying, evaluating and comparing different recent scenarios on the availability of uranium. While there are some differences in the frame conditions (e.g. the expected uranium demand, the time fame, the considered mining projects,..), there are also notable similarities in these scenarios. This concerns long lead times for mine openings as well as the dependence on large mining projects (e.g. Olympic Dam, Cigar Lake). Generally, a decline in production in about 10 years is assumed, and thus the necessity of the timely development of mining projects is pointed out. In addition the omission of uranium from Russian nuclear weapons and the chances of keeping the changes in secondary supplies in balance with primary production have been widely discussed. Here, the production growth in Kazakhstan but also the role of the current market situation are central aspects. As another aspect the possible contribution from unconventional resources is of interest, particularly against the background of rising production costs for conventional resources. Finally, it shall be reflected how well older scenarios were able to map the reality and which trends could or could not be anticipated. It is relevant to identify which aspects in the development of mining capacities are essential for security of supply, and can therefore be regarded

  7. Determination of point isotropic buildup factors of gamma rays including incoherent and coherent scattering for aluminum, iron, lead, and water by discrete ordinates method

    International Nuclear Information System (INIS)

    Kitsos, S.; Assad, A.; Diop, C.M.; Nimal, J.C.

    1994-01-01

    Exposure and energy absorption buildup factors for aluminum, iron, lead, and water are calculated by the SNID discrete ordinates code for an isotropic point source in a homogeneous medium. The calculation of the buildup factors takes into account the effects of both bound-electron Compton (incoherent) and coherent (Rayleigh) scattering. A comparison with buildup factors from the literature shows that these two effects greatly increase the buildup factors for energies below a few hundred kilo-electron-volts, and thus the new results are improved relative to the experiment. This greater accuracy is due to the increase in the linear attenuation coefficient, which leads to the calculation of the buildup factors for a mean free path with a smaller shield thickness. On the other hand, for the same shield thickness, exposure increases when only incoherent scattering is included and decreases when only coherent scattering is included, so that the exposure finally decreases when both effects are included. Great care must also be taken when checking the approximations for gamma-ray deep-penetration transport calculations, as well as for the cross-section treatment and origin

  8. Scenario Development for Trgovska Gora Shallow Land Facility

    International Nuclear Information System (INIS)

    Skanata, D.; Medakovic, S.; Lokner, V.; Levanat, I.

    2002-01-01

    Safety assessments, either preliminary or final, consist of a qualitative and a quantitative part. The qualitative part of the assessment implies a selection of relevant scenarios to be analyzed, while the quantitative part of the assessment consists of their mathematical modeling. This work is dealing with the qualitative part of safety assessment concerning a specific radioactive waste disposal system, i.e., the shallow land facility situated on the macrolocation Trgovska gora. This article has as its purpose a brief presentation of the ISAM methodology application results (Improvement of Safety Assessment Methodologies for Near Surface Radioactive Waste Facilities;), a methodology developed within the framework of a project of the same name, organized by the IAEA. The above mentioned methodology is based on the development of the so-called FEP list (Features, Events, Process), on selection procedure of the FEP list, specifically regarding particular criteria defined in advance, and on application of systematic methods of selecting relevant scenarios (in this case the matrix of interactions method has been applied). The main aim and purpose of a methodology based on the analysis of FEPs (identification, classification, selection, construction of the matrix of interactions) consists of observing and documenting all the features, events and processes due to be taken into consideration while assessing safety of a particular radioactive waste disposal system. In this connection, by radioactive waste disposal system we mean a system consisting of radioactive waste and engineer features (barriers), geological environment within which the disposal site is located, surface-environment (soil, sediments, vegetation, etc.) and human population near the disposal site. The final step of the application of this methodology consists of generating the scenario using the matrix of interactions. So, for shallow land facility situated on the macrolocation Trgovska gora, applying

  9. Ion Composition and Energization in the Earth's Inner Magnetosphere and the Effects on Ring Current Buildup

    Science.gov (United States)

    Keika, K.; Kistler, L. M.; Brandt, P. C.

    2014-12-01

    In-situ observations and modeling work have confirmed that singly-charged oxygen ions, O+, which are of Earth's ionospheric origin, are heated/accelerated up to >100 keV in the magnetosphere. The energetic O+ population makes a significant contribution to the plasma pressure in the Earth's inner magnetosphere during magnetic storms, although under quiet conditions H+ dominates the plasma pressure. The pressure enhancements, which we term energization, are caused by adiabatic heating through earthward transport of source population in the plasma sheet, local acceleration in the inner magnetosphere and near-Earth plasma sheet, and enhanced ion supply from the topside ionosphere. The key issues regarding stronger O+ energization than H+ are non-adiabatic local acceleration, responsible for increase in O+ temperature, and more significant O+ supply than H+, responsible for increase in O+ density. Although several acceleration mechanisms and O+ supply processes have been proposed, it remains an open question what mechanism(s)/process(es) play the dominant role in stronger O+ energization. In this paper we summarize important spacecraft observations including those from Van Allen Probes, introduces the proposed mechanisms/processes that generate O+-rich energetic plasma population, and outlines possible scenarios of O+ pressure abundance in the Earth's inner magnetosphere.

  10. HIMMELI v1.0: HelsinkI Model of MEthane buiLd-up and emIssion for peatlands

    Science.gov (United States)

    Raivonen, Maarit; Smolander, Sampo; Backman, Leif; Susiluoto, Jouni; Aalto, Tuula; Markkanen, Tiina; Mäkelä, Jarmo; Rinne, Janne; Peltola, Olli; Aurela, Mika; Lohila, Annalea; Tomasic, Marin; Li, Xuefei; Larmola, Tuula; Juutinen, Sari; Tuittila, Eeva-Stiina; Heimann, Martin; Sevanto, Sanna; Kleinen, Thomas; Brovkin, Victor; Vesala, Timo

    2017-12-01

    Wetlands are one of the most significant natural sources of methane (CH4) to the atmosphere. They emit CH4 because decomposition of soil organic matter in waterlogged anoxic conditions produces CH4, in addition to carbon dioxide (CO2). Production of CH4 and how much of it escapes to the atmosphere depend on a multitude of environmental drivers. Models simulating the processes leading to CH4 emissions are thus needed for upscaling observations to estimate present CH4 emissions and for producing scenarios of future atmospheric CH4 concentrations. Aiming at a CH4 model that can be added to models describing peatland carbon cycling, we composed a model called HIMMELI that describes CH4 build-up in and emissions from peatland soils. It is not a full peatland carbon cycle model but it requires the rate of anoxic soil respiration as input. Driven by soil temperature, leaf area index (LAI) of aerenchymatous peatland vegetation, and water table depth (WTD), it simulates the concentrations and transport of CH4, CO2, and oxygen (O2) in a layered one-dimensional peat column. Here, we present the HIMMELI model structure and results of tests on the model sensitivity to the input data and to the description of the peat column (peat depth and layer thickness), and demonstrate that HIMMELI outputs realistic fluxes by comparing modeled and measured fluxes at two peatland sites. As HIMMELI describes only the CH4-related processes, not the full carbon cycle, our analysis revealed mechanisms and dependencies that may remain hidden when testing CH4 models connected to complete peatland carbon models, which is usually the case. Our results indicated that (1) the model is flexible and robust and thus suitable for different environments; (2) the simulated CH4 emissions largely depend on the prescribed rate of anoxic respiration; (3) the sensitivity of the total CH4 emission to other input variables is mainly mediated via the concentrations of dissolved gases, in particular, the O2

  11. HIMMELI v1.0: HelsinkI Model of MEthane buiLd-up and emIssion for peatlands

    Directory of Open Access Journals (Sweden)

    M. Raivonen

    2017-12-01

    Full Text Available Wetlands are one of the most significant natural sources of methane (CH4 to the atmosphere. They emit CH4 because decomposition of soil organic matter in waterlogged anoxic conditions produces CH4, in addition to carbon dioxide (CO2. Production of CH4 and how much of it escapes to the atmosphere depend on a multitude of environmental drivers. Models simulating the processes leading to CH4 emissions are thus needed for upscaling observations to estimate present CH4 emissions and for producing scenarios of future atmospheric CH4 concentrations. Aiming at a CH4 model that can be added to models describing peatland carbon cycling, we composed a model called HIMMELI that describes CH4 build-up in and emissions from peatland soils. It is not a full peatland carbon cycle model but it requires the rate of anoxic soil respiration as input. Driven by soil temperature, leaf area index (LAI of aerenchymatous peatland vegetation, and water table depth (WTD, it simulates the concentrations and transport of CH4, CO2, and oxygen (O2 in a layered one-dimensional peat column. Here, we present the HIMMELI model structure and results of tests on the model sensitivity to the input data and to the description of the peat column (peat depth and layer thickness, and demonstrate that HIMMELI outputs realistic fluxes by comparing modeled and measured fluxes at two peatland sites. As HIMMELI describes only the CH4-related processes, not the full carbon cycle, our analysis revealed mechanisms and dependencies that may remain hidden when testing CH4 models connected to complete peatland carbon models, which is usually the case. Our results indicated that (1 the model is flexible and robust and thus suitable for different environments; (2 the simulated CH4 emissions largely depend on the prescribed rate of anoxic respiration; (3 the sensitivity of the total CH4 emission to other input variables is mainly mediated via the concentrations of dissolved gases, in particular

  12. Monte Carlo simulation of x-ray buildup factors of lead and its applications in shielding of diagnostic x-ray facilities

    International Nuclear Information System (INIS)

    Kharrati, Hedi; Agrebi, Amel; Karaoui, Mohamed-Karim

    2007-01-01

    X-ray buildup factors of lead in broad beam geometry for energies from 15 to 150 keV are determined using the general purpose Monte Carlo N-particle radiation transport computer code (MCNP4C). The obtained buildup factors data are fitted to a modified three parameter Archer et al. model for ease in calculating the broad beam transmission with computer at any tube potentials/filters combinations in diagnostic energies range. An example for their use to compute the broad beam transmission at 70, 100, 120, and 140 kVp is given. The calculated broad beam transmission is compared to data derived from literature, presenting good agreement. Therefore, the combination of the buildup factors data as determined and a mathematical model to generate x-ray spectra provide a computationally based solution to broad beam transmission for lead barriers in shielding x-ray facilities

  13. SITE-94. The central scenario for SITE-94: A climate change scenario

    International Nuclear Information System (INIS)

    King-Clayton, L.M.; Chapman, N.A.; Kautsky, F.; Svensson, N.O.; Ledoux, E.

    1995-12-01

    The central scenario includes the following main components: a deterministic description of the most probable climatic state for Sweden (with special ref. to the Aespoe area) for the next c. 120,000 years, a description of the likely nature of the surface and geological environment in the area at each stage of the climate sequence selected, and quantitative information on how these changes might affect the disposal system. The climate models suggest glacial maxima at c. 5, 20, 60 and 100 thousand years from now. The Aespoe region is predicted to be significantly affected by the latter three glacial episodes, with the ice sheet reaching and covering the area during the latter two episodes (by up to c 2200m and 1200m thickness of ice, resp.). Permafrost thicknesses over the next 120,000 years have been calculated. Assumptions, estimates and alternatives to the prescribed climate evolution are discussed. Following definition of a realistic, albeit non-unique, climate sequence, the objective of scenario development is to provide an indicator of the physical, chemical and hydrogeological conditions at the front of and beneath the advancing and retreating ice sheets, with the aim of identifying critical aspects for Performance Assessment modelling. The effect of various factors, such as ice loading, development of permafrost, temperature changes and sea level changes are considered in terms of their impact on hydrogeology, groundwater chemistry, rock stress and surface environments. 183 refs

  14. SITE-94. The central scenario for SITE-94: A climate change scenario

    Energy Technology Data Exchange (ETDEWEB)

    King-Clayton, L M; Chapman, N A [QuantiSci Ltd, Melton Mowbray (United Kingdom); Kautsky, F [Swedish Nuclear Power Inspectorate, Stockholm (Sweden); Svensson, N O [Lund Univ. (Sweden). Dept. of Quaternary Geology; Marsily, G de [Univ. VI Paris (France); Ledoux, E [Ecole Nationale Superieure des Mines, 77 - Fontainebleau (France)

    1995-12-01

    The central scenario includes the following main components: a deterministic description of the most probable climatic state for Sweden (with special ref. to the Aespoe area) for the next c. 120,000 years, a description of the likely nature of the surface and geological environment in the area at each stage of the climate sequence selected, and quantitative information on how these changes might affect the disposal system. The climate models suggest glacial maxima at c. 5, 20, 60 and 100 thousand years from now. The Aespoe region is predicted to be significantly affected by the latter three glacial episodes, with the ice sheet reaching and covering the area during the latter two episodes (by up to c 2200m and 1200m thickness of ice, resp.). Permafrost thicknesses over the next 120,000 years have been calculated. Assumptions, estimates and alternatives to the prescribed climate evolution are discussed. Following definition of a realistic, albeit non-unique, climate sequence, the objective of scenario development is to provide an indicator of the physical, chemical and hydrogeological conditions at the front of and beneath the advancing and retreating ice sheets, with the aim of identifying critical aspects for Performance Assessment modelling. The effect of various factors, such as ice loading, development of permafrost, temperature changes and sea level changes are considered in terms of their impact on hydrogeology, groundwater chemistry, rock stress and surface environments. 183 refs.

  15. Biomass Scenario Model | Energy Analysis | NREL

    Science.gov (United States)

    Biomass Scenario Model Biomass Scenario Model The Biomass Scenario Model (BSM) is a unique range of lignocellulosic biomass feedstocks into biofuels. Over the past 25 years, the corn ethanol plant matter (lignocellulosic biomass) to fermentable sugars for the production of fuel ethanol

  16. Influence of light-exposure methods and depths of cavity on the microhardness of dual-cured core build-up resin composites

    Directory of Open Access Journals (Sweden)

    Keiichi YOSHIDA

    2014-01-01

    Full Text Available Objective: The purpose of this study was to evaluate the Knoop hardness number (KHN of dual-cured core build-up resin composites (DCBRCs at 6 depths of cavity after 3 post-irradiation times by 4 light-exposure methods. Material and Methods: Five specimens each of DCBRCs (Clearfil DC Core Plus [DCP] and Unifil Core EM [UCE] were filled in acrylic resin blocks with a semi-cylindrical cavity and light-cured using an LED light unit (power density: 1,000 mW/cm2at the top surface by irradiation for 20 seconds (20 s, 40 seconds (40 s, bonding agent plus 20 seconds (B+20 s, or 40 seconds plus light irradiation of both sides of each acrylic resin block for 40 seconds each (120 s. KHN was measured at depths of 0.5, 2.0, 4.0, 6.0, 8.0, and 10.0 mm at 0.5 hours, 24 hours, and 7 days post-irradiation. Statistical analysis was performed using repeated measures ANOVA and Tukey's compromise post-hoc test with a significance level of p0.05. In DCP, and not UCE, at 24 hours and 7 days post-irradiation, the B+20 s method showed significantly higher KHN at all depths of cavity, except the depth of 0.5 mm (p<0.05. Conclusion: KHN depends on the light-exposure method, use of bonding agent, depth of cavity, post-irradiation time, and material brand. Based on the microhardness behavior, DCBRCs are preferably prepared by the effective exposure method, when used for a greater depth of cavity.

  17. Inversion Build-Up and Cold-Air Outflow in a Small Alpine Sinkhole

    Science.gov (United States)

    Lehner, Manuela; Whiteman, C. David; Dorninger, Manfred

    2017-06-01

    Semi-idealized model simulations are made of the nocturnal cold-air pool development in the approximately 1-km wide and 100-200-m deep Grünloch basin, Austria. The simulations show qualitatively good agreement with vertical temperature and wind profiles and surface measurements collected during a meteorological field expedition. A two-layer stable atmosphere forms in the basin, with a very strong inversion in the lowest part, below the approximate height of the lowest gap in the surrounding orography. The upper part of the stable layer is less strongly stratified and extends to the approximate height of the second-lowest gap. The basin atmosphere cools most strongly during the first few hours of the night, after which temperatures decrease only slowly. An outflow of air forms through the lowest gap in the surrounding orography. The outflow connects with a weak inflow of air through a gap on the opposite sidewall, forming a vertically and horizontally confined jet over the basin. Basin cooling shows strong sensitivity to surface-layer characteristics, highlighting the large impact of variations in vegetation and soil cover on cold-air pool development, as well as the importance of surface-layer parametrization in numerical simulations of cold-air-pool development.

  18. Endodontic treatment and esthetic management of a primary double tooth with direct composite using silicone buildup guide

    Directory of Open Access Journals (Sweden)

    Vinaya Kumar Kulkarni

    2012-01-01

    Full Text Available Gemination and fusion are morphological dental anomalies, characterized by the formation of a clinically wide tooth. Gemination occurs when one tooth bud tries to divide, while fusion occurs if two buds unite. The terms double teeth, double formation, conjoined teeth, geminifusion, vicinifusion and dental twinning are often used to describe fusion and gemination. Double teeth are associated with clinical problems such as poor esthetics, spacing problems and caries susceptibility. Management of such cases requires a comprehensive knowledge of the clinical entity as well as the problems associated with it. This report presents a case of primary double tooth in a 6-year-old boy involving maxillary left central incisor. The anomalous tooth was carious and pulpally involved. This was treated conservatively by endodontic treatment and esthetic rehabilitation was done with direct composite restoration using a silicone buildup guide. The treated tooth was followed up until exfoliation.

  19. Modeling of gamma ray energy-absorption buildup factors for thermoluminescent dosimetric materials using multilayer perceptron neural network

    DEFF Research Database (Denmark)

    Kucuk, Nil; Manohara, S.R.; Hanagodimath, S.M.

    2013-01-01

    In this work, multilayered perceptron neural networks (MLPNNs) were presented for the computation of the gamma-ray energy absorption buildup factors (BA) of seven thermoluminescent dosimetric (TLD) materials [LiF, BeO, Na2B4O7, CaSO4, Li2B4O7, KMgF3, Ca3(PO4)2] in the energy region 0.015–15Me......V, and for penetration depths up to 10 mfp (mean-free-path). The MLPNNs have been trained by a Levenberg–Marquardt learning algorithm. The developed model is in 99% agreement with the ANSI/ANS-6.4.3 standard data set. Furthermore, the model is fast and does not require tremendous computational efforts. The estimated BA...

  20. Applications of Monte Carlo codes to a study of gamma-ray buildup factors, skyshine and duct streaming

    Energy Technology Data Exchange (ETDEWEB)

    Hirayama, H. [High Energy Accelerator Research Organization (KEK), Ibaraki (Japan)

    2001-07-01

    Many shielding calculations for gamma-rays have continued to rely on point-kernel methods incorporating buildup factor data. Line beam or conical beam response functions, which are calculated using a Monte Carlo code, for skyshine problems are useful to estimate the skyshine dose from various facilities. A simple calculation method for duct streaming was proposed using the parameters calculated by the Monte Carlo code. It is therefore important to study, improve and produce basic parameters related to old, but still important, problems in the fields of radiation shielding using the Monte Carlo code. In this paper, these studies performed by several groups in Japan as applications of the Monte Carlo method are discussed. (orig.)

  1. Resonant laser power build-up in ALPS-A 'light shining through a wall' experiment

    Energy Technology Data Exchange (ETDEWEB)

    Ehret, Klaus [Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, D-22607 Hamburg (Germany); Frede, Maik [Laser Zentrum Hannover e.V., Hollerithallee 8, D-30419 Hannover (Germany); Ghazaryan, Samvel [Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, D-22607 Hamburg (Germany); Hildebrandt, Matthias [Laser Zentrum Hannover e.V., Hollerithallee 8, D-30419 Hannover (Germany); Knabbe, Ernst-Axel [Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, D-22607 Hamburg (Germany); Kracht, Dietmar [Laser Zentrum Hannover e.V., Hollerithallee 8, D-30419 Hannover (Germany); Lindner, Axel, E-mail: axel.lindner@desy.d [Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, D-22607 Hamburg (Germany); List, Jenny [Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, D-22607 Hamburg (Germany); Meier, Tobias [Max-Planck-Institute for Gravitational Physics, Albert-Einstein-Institute, and Institut fuer Gravitationsphysik, Leibniz Universitaet, Hannover, Callinstrasse 38, D-30167 Hannover (Germany); Meyer, Niels; Notz, Dieter; Redondo, Javier; Ringwald, Andreas [Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, D-22607 Hamburg (Germany); Wiedemann, Guenter [Hamburger Sternwarte, Gojenbergsweg 112, D-21029 Hamburg (Germany); Willke, Benno [Max-Planck-Institute for Gravitational Physics, Albert-Einstein-Institute, and Institut fuer Gravitationsphysik, Leibniz Universitaet, Hannover, Callinstrasse 38, D-30167 Hannover (Germany)

    2009-12-21

    The ALPS Collaboration runs a 'light shining through a wall' (LSW) experiment to search for photon oscillations into 'weakly interacting sub-eV particles' (WISPs) inside of a superconducting HERA dipole magnet at the site of DESY. In this paper we report on the first successful integration of a large-scale optical resonant cavity to boost the available power for WISP production in this type of experiments. The key elements are a frequency tunable narrow line-width continuous wave laser acting as the primary light source and an electronic feed-back control loop to stabilize the power build-up. We describe and characterize our apparatus and demonstrate the data analysis procedures on the basis of a brief exemplary run.

  2. Evaluation of pollutant build-up and wash-off from selected land uses at the Port of Brisbane, Australia.

    Science.gov (United States)

    Goonetilleke, Ashantha; Egodawatta, Prasanna; Kitchen, Brad

    2009-02-01

    The quality of stormwater runoff from seaports can be an important source of pollution to the marine environment. Currently, little knowledge exists with regards to the pollutant generation capacity specific to seaports as they do not necessarily compare well with conventional urban land use. The research project focussed on the assessment of pollutant build-up and wash-off. The study was undertaken using rainfall simulation and small impervious plots for different port land uses with the results obtained compared to typical urban land uses. The study outcomes confirmed that the Port land uses exhibit comparatively lower pollutant concentrations. However, the pollutant characteristics varied across different land uses. Hence, the provision of stereotypical water quality improvement measures could be of limited value. Particle size < 150microm was predominant in suspended solids. Therefore, if suspended solids are targeted as the surrogate parameter for water quality improvement, this particle size range needs to be removed.

  3. Resonant laser power build-up in ALPS. A 'light-shining-through-walls' experiment

    Energy Technology Data Exchange (ETDEWEB)

    Ehret, Klaus; Ghazaryan, Samvel [Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany); Frede, Maik [Laser Zentrum Hannover e.V. (DE)] (and others)

    2009-05-15

    The ALPS collaboration runs a light-shining-through-walls (LSW) experiment to search for photon oscillations into weakly interacting sub-eV particles (WISPs) inside of a superconducting HERA dipole magnet at the site of DESY. In this paper we report on the first successful integration of a large-scale optical cavity to boost the available power for WISP production in this type of experiments. The key elements are a frequency tunable narrow line-width continuous wave laser acting as the primary light source and an electronic feed-back control loop to stabilize the power build-up. We describe and characterize our apparatus and demonstrate the data analysis procedures on the basis of a brief exemplary run. (orig.)

  4. Dynamic model for tritium build-up at NPP with RBMK type reactors and its enviromental beraviour

    International Nuclear Information System (INIS)

    Badyaev, V.V.; Egorov, Yu.A.; Ivanov, E.A.; Stegachev, G.F.; Tolstykh, V.D.

    1982-01-01

    A model of tritium production dynamics for a high power NPP with RBMK type reactors is proposed and investigated. The main ''skeleton'' model structure for forecasting tritium buildup at a NPP and its exchange with the environment has been singled out at a heuristic level. Decomposition and layout of the units have been performed by global functional relations of the investigated objects (NPP and environment). the model accounts for only oxidized tritium forms. Water exchange between the NPP subsystems and environment is the main mechanism for tritium migration. The model does not account for scheduled periodic maintenance work effects, presence of stagnant zones in the station circuits, fuel burn-up, etc. The parametric identification method applied in the model makes the model adaptable to particular situations and considered systems of the NPP and environment. Completing the model with necessary and sufficient experimental data one can pass to certain forecasting problems and to NPP control as a tritium source in the environment

  5. Development scenario for laser fusion

    International Nuclear Information System (INIS)

    Maniscalco, J.A.; Hovingh, J.; Buntzen, R.R.

    1976-01-01

    This scenario proposes establishment of test and engineering facilities to (1) investigate the technological problems associated with laser fusion, (2) demonstrate fissile fuel production, and (3) demonstrate competitive electrical power production. Such facilities would be major milestones along the road to a laser-fusion power economy. The relevant engineering and economic aspects of each of these research and development facilities are discussed. Pellet design and gain predictions corresponding to the most promising laser systems are presented for each plant. The results show that laser fusion has the potential to make a significant contribution to our energy needs. Beginning in the early 1990's, this new technology could be used to produce fissile fuel, and after the turn of the century it could be used to generate electrical power

  6. Initial surface deformations during impact on a liquid pool

    NARCIS (Netherlands)

    Bouwhuis, W.; Hendrix, M.H.W.; van der Meer, Roger M.; Snoeijer, Jacobus Hendrikus

    2015-01-01

    A tiny air bubble can be entrapped at the bottom of a solid sphere that impacts onto a liquid pool. The bubble forms due to the deformation of the liquid surface by a local pressure buildup inside the surrounding gas, as also observed during the impact of a liquid drop on a solid wall. Here, we

  7. Radiation Detection Computational Benchmark Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Shaver, Mark W.; Casella, Andrew M.; Wittman, Richard S.; McDonald, Ben S.

    2013-09-24

    Modeling forms an important component of radiation detection development, allowing for testing of new detector designs, evaluation of existing equipment against a wide variety of potential threat sources, and assessing operation performance of radiation detection systems. This can, however, result in large and complex scenarios which are time consuming to model. A variety of approaches to radiation transport modeling exist with complementary strengths and weaknesses for different problems. This variety of approaches, and the development of promising new tools (such as ORNL’s ADVANTG) which combine benefits of multiple approaches, illustrates the need for a means of evaluating or comparing different techniques for radiation detection problems. This report presents a set of 9 benchmark problems for comparing different types of radiation transport calculations, identifying appropriate tools for classes of problems, and testing and guiding the development of new methods. The benchmarks were drawn primarily from existing or previous calculations with a preference for scenarios which include experimental data, or otherwise have results with a high level of confidence, are non-sensitive, and represent problem sets of interest to NA-22. From a technical perspective, the benchmarks were chosen to span a range of difficulty and to include gamma transport, neutron transport, or both and represent different important physical processes and a range of sensitivity to angular or energy fidelity. Following benchmark identification, existing information about geometry, measurements, and previous calculations were assembled. Monte Carlo results (MCNP decks) were reviewed or created and re-run in order to attain accurate computational times and to verify agreement with experimental data, when present. Benchmark information was then conveyed to ORNL in order to guide testing and development of hybrid calculations. The results of those ADVANTG calculations were then sent to PNNL for

  8. The rudist buildup depositional model, reservoir architecture and development strategy of the cretaceous Sarvak formation of Southwest Iran

    Directory of Open Access Journals (Sweden)

    Yang Du

    2015-03-01

    Full Text Available This paper studies the lithofacies, sedimentary facies, depositional models and reservoir architecture of the rudist-bearing Sar-3 zone of Cretaceous Sarvak in the Southwest of Iran by utilizing coring, thin section, XRD data of five coring wells and 3D seismic data. Research results include the following: According to lithofacies features and their association, the rudist-mound and tidal flat are the main microfacies in the Sar-3 depositional time. By investigating the regional tectonic setting and seismic interpretation, a depositional model was built for the Sar-3 zone, which highlights four key points: 1 The distribution of the rudist-buildup is controlled by the paleo-high. 2 The build-up outside of the wide colonize stage but reached the wave-base level in a short time by regression and formation uplift, and was destroyed by the high energy current, then forming the moundy allochthonous deposition after being dispersed and redeposited. 3 The tidal flat develops widely in the upper Sar-3, and the deposition thickness depends on the paleo-structure. The tidal channel develops in the valley and fringe of the Paleo-structure. 4 The exposure within the leaching effect by the meteoric water of the top of Sar-3 is the main controlling factor of the reservoir vertical architecture. The Sar-3 zone featured as the dualistic architecture consists of two regions: the lower is the rudist reef limestone reservoir and the upper is the tidal condense limestone interlayer. The thickness of each is controlled by the paleo-structure. The Paleo-high zone is the preferential development zone. Based on reservoir characteristics of the different zones, a targeted development strategy has been proposed. Keeping the trajectory in the middle of the oil-layer in the paleo-high, and in the paleo-low, make the trajectory crossing the oil-zone and then keep it in the lower.

  9. A resin composite material containing an eugenol derivative for intracanal post cementation and core build-up restoration.

    Science.gov (United States)

    Almaroof, A; Rojo, L; Mannocci, F; Deb, S

    2016-02-01

    To formulate and evaluate new dual cured resin composite based on the inclusion of eugenyl methacrylate monomer (EgMA) with Bis-GMA/TEGDMA resin systems for intracanal post cementation and core build-up restoration of endodontically treated teeth. EgMA was synthesized and incorporated at 5% (BTEg5) or 10% (BTEg10) into dual-cure formulations. Curing properties, viscosity, Tg, radiopacity, static and dynamic mechanical properties of the composites were determined and compared with Clearfil™DC Core-Plus, a commercial dual-cure, two-component composite. Statistical analysis of the data was performed with ANOVA and the Tukey's post-hoc test. The experimental composites were successfully prepared, which exhibited excellent curing depths of 4.9, 4.7 and 4.2 mm for BTEg0, BTEg5 and BTEg10 respectively, which were significantly higher than Clearfil™DC. However, the inclusion of EgMA initially led to a lower degree of cure, which increased when measured at 24 h with values comparable to formulations without EgMA, indicating post-curing. The inclusion of EgMA also lowered the polymerization exotherm thereby reducing the potential of thermal damage to host tissue. Both thermal and viscoelastic analyses confirmed the ability of the monomer to reduce the stiffness of the composites by forming a branched network. The compressive strength of BTEg5 was significantly higher than the control whilst flexural strength increased significantly from 95.9 to 114.8 MPa (BTEg5) and 121.9 MPa (BTEg10). Radiopacity of the composites was equivalent to ∼3 mm Al allowing efficient diagnosis. The incorporation of EgMA within polymerizable formulations provides a novel approach to prepare reinforced resin composite material for intracanal post cementation and core build-up and the potential to impart antibacterial properties of eugenol to endodontic restorations. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  10. Stochastic Optimization for Nuclear Facility Deployment Scenarios

    Science.gov (United States)

    Hays, Ross Daniel

    to eventual disposal. By varying the specifications of the deployment scenario, the simulated annealing algorithm will seek to either minimize the value of a single objective function, or enumerate the trade-off surface between multiple competing objective functions. The available objective functions represent key stakeholder values, minimizing such important factors as high-level waste disposal burden, required uranium ore supply, relative proliferation potential, and economic cost and uncertainty. The optimization program itself is designed to be modular, allowing for continued expansion and exploration as research needs and curiosity indicate. The utility and functionality of this optimization program are demonstrated through its application to one potential fuel cycle scenario of interest. In this scenario, an existing legacy LWR fleet is assumed at the year 2000. The electric power demand grows exponentially at a rate of 1.8% per year through the year 2100. Initially, new demand is met by the construction of 1-GW(e) LWRs. However, beginning in the year 2040, 600-MW(e) sodium-cooled, fast-spectrum reactors operating in a transuranic burning regime with full recycling of spent fuel become available to meet demand. By varying the fraction of new capacity allocated to each reactor type, the optimization program is able to explicitly show the relationships that exist between uranium utilization, long-term heat for geologic disposal, and cost-of-electricity objective functions. The trends associated with these trade-off surfaces tend to confirm many common expectations about the use of nuclear power, namely that while overall it is quite insensitive to variations in the cost of uranium ore, it is quite sensitive to changes in the capital costs of facilities. The optimization algorithm has shown itself to be robust and extensible, with possible extensions to many further fuel cycle optimization problems of interest.

  11. Trust and the illusive force of scenarios

    DEFF Research Database (Denmark)

    Selin, Cynthia Lea

    2006-01-01

    formulation and decision-making. By definition, scenarios are possible versions of the future so judging and evaluating scenarios is thus not about revealing truthfulness, but rather demonstrating trust, reliability, credibility in the absence of truth and in the face of varied influences and possible...... becomes interesting is how scenarios convey authority and trustworthiness. How is it that scenarios attain and maintain power to compel people to action, change their worldview, or influence the directions of decisions or consensus? This piece examines the process, participation and products of scenario...

  12. Input parameters and scenarios, including economic inputs

    DEFF Research Database (Denmark)

    Boklund, Anette; Hisham Beshara Halasa, Tariq

    2012-01-01

    scenarios, we excluded hobby-type farms1 In the vaccination scenarios, herds within the vaccination zone were simulated to be vaccinated 14 days after detection of the first herd or when 10, 20, 30 or 50 herds were infected. All herds within the zones were simulated to be vaccinated. We used vaccination...... zones of either a 1, 2, 3 or 5 km. In some scenarios, hobby herds were not vaccinated. In one scenario, no sheep were vaccinated, and in another scenario no swine were vaccinated. from depopulation in zones. The resources for depopulation were estimated to 4,800 swine and 2,000 ruminants a day...

  13. Nuclear power prospects and potential: scenarios

    International Nuclear Information System (INIS)

    Rogner, Hans-Hogler; McDonald, Alan; )

    2002-01-01

    This paper outlines a range of scenarios describing what the world's energy system might look in the middle of the century, and what nuclear energy's most profitable role might be. The starting point is the 40 non-greenhouse-gas-mitigation scenarios in the Special Report on Emission Scenarios (SRES) of the Intergovernmental Panel on Climate Change (IPCC). Given their international authorship and comprehensive review by governments and scientific experts, the SRES scenarios are the state of the art in long-term energy scenarios

  14. Towards a user's guide to scenarios - a report on scenario types and scenario techniques

    Energy Technology Data Exchange (ETDEWEB)

    Boerjeson, Lena; Hoejer, Mattias; Dreborg, Karl-Henrik; Finnveden, Goeran [Royal Inst. of Technology, Stockholm (Sweden). Environmental Strategies Research - fms; Ekvall, Tomas [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Energy and Environment

    2005-11-01

    Futures studies consist of a vast variation of studies and approaches. The aim of this paper is to contribute to the understanding of for what purposes scenarios are useful and what methods and procedures are useful for furthering these purposes. We present a scenario typology with an aim to better suit the context in which the scenarios are used. The scenario typology is combined with a new way of looking at scenario techniques, i.e. practical methods and procedures for scenario development. Finally, we look at the usefulness of scenarios in the light of the scenario typology and the scenario techniques. As a start, we distinguish between three main categories of scenario studies. The classification is based on the principal questions we believe a user may want to pose about the future. The resolution is then increased by letting each category contain two different scenario types. These are distinguished by different angles of approach of the questions defining the categories. The first question, What will happen?, is responded to by Predictive scenarios. In fact, the response to a question like this will always be conditional, e.g. of a stable and peaceful world, or by a certain continuous development of some kind. We have utilized this fact when defining the two predictive scenario types, Forecasts and What-if scenarios. The second question, What can happen?, is responded to by Explorative scenarios. The scenarios are thus explorations of what might happen in the future, regardless of beliefs of what is likely to happen or opinions of what is desirable. This category is further divided into external and strategic scenarios. The final question, How can a specific target be reached?, is responded to by Normative scenarios. Such studies are explicitly normative, since they take a target as a starting point. They are often directed towards how the target could be reached. This category is divided into preserving and transforming scenarios. If the user wants to

  15. Scientific data and climate scenarios. Study report nr 2

    International Nuclear Information System (INIS)

    Alex, Bastien; Baillat, Alice; Francois Gemenne; Jean Jouzel

    2017-05-01

    The objective of this report is to present climate evolutions and their impacts according to two warming scenarios: a 2 degree increase of the average surface temperature by 2100 (i.e. the most optimistic IPCC scenario), and a 5 degree increase by 2100 (the most pessimistic scenario). As far as possible, physical, social and economic, and health impacts are assessed by 2030 and 2050. The authors notice that the differences between both scenarios are hardly discernible by 2030, but more obviously by 2050. After a brief recall on IPCC scenarios, a first part addresses the evolutions of the world climate by considering the atmosphere (temperature increase, modification of precipitation regimes), seas and oceans (temperature, currents and thermal circulation, ocean acidification, seal level rise), extreme climate events (observations and trends, main impacts on populations and infrastructures), and the cryo-sphere (observations and impacts). The second part discusses regional predictions in terms of trends and impacts for metropolitan France and its overseas territories, for Africa, and for the Asia-Pacific region. The last part briefly discusses the possibly necessary evolution of the typology chosen to determine sources of vulnerability and the level of exposure to different risks. Many appendices propose more detailed presentations on specific issues and examples. A summarised version of the report is also provided

  16. Variations in 6MV x-ray radiotherapy build-up dose with treatment distance

    International Nuclear Information System (INIS)

    Butson, M.J.; Illawarra Cancer Care Centre, Wollongong, NSW; Cheung, T.; Yu, P.K.N.

    2003-01-01

    Dose in the build up region for high energy x-rays produced by a medical linear accelerator is affected by the x-ray source to patient surface distance (SSD). The use of isocentric treatments whereby the tumour is positions 100cm from the source means that depending of the depth of the tumour and the size of the patient, the SSD can vary from distances of 80cm to 100cm. To achieve larger field sizes, the SSD can also be extended out to 120cm at times. Results have shown that open fields are not significantly affected by SSD changes with deviations in percentage dose being less than 4% of maximum dose for SSD's from 80cm to 120cm SSD. With the introduction of beam modifying devices such as Perspex blocking trays, the effects are significant with a deviation of up to 22% measured at 6MV energy with a 6mm Perspex tray for SSD's from 80cm to 120cm. These variations are largest at the skin surface and reduce with depth. The use of a multi leaf collimator for blocking removes extra skin dose caused by the Perspex block trays with decreasing SSD. Copyright (2003) Australasian College of Physical Scientists and Engineers in Medicine

  17. Radioactive well logging system with shale (boron) compensation by gamma ray build-up

    International Nuclear Information System (INIS)

    Peelman, H.E.; Arnold, D.M.; Pitts, R.W. Jr.

    1976-01-01

    Earth formations in the vicinity of a well borehole are repetitively bombarded with bursts of high energy neutrons. A radiation detector in a sonde in the borehole senses the gamma rays induced by the capture of thermal neutrons and sends signals representative thereof to the surface. At the surface, two single channel energy analyzers, such as from 1.30 to 2.92 MeV and from 3.43 to 10.0 MeV, sense the formation thermal neutron capture gamma ray response after each neutron burst. The counts of thermal neutron capture gamma rays in these analyzers are used to distinguish between the presence of salt water and hydrocarbons, which is logged. By controlling the repetition rate of the neutron source, measured counting rates in formations with relatively large thermal neutron lifetimes are emphasized, compensating for borehole effects which could otherwise give rise to erroneous results in shale formations, which have a high boron content. 11 claims, 5 figures

  18. Review of surface dose detectors in radiotherapy

    LENUS (Irish Health Repository)

    O'Shea, E.

    2006-11-20

    Several instruments have been used to measure absorbed radiation dose under non-electronic equilibrium conditions, such as in the build-up region or near the interface between two different media, including the surface. Many of these detectors are discussed in this paper. A common method of measuring the absorbed dose distribution and electron contamination in the build-up region of high-energy beams for radiation therapy is by means of parallel-plate ionisation chambers. Thermoluminescent dosimeters (TLDs), diodes and radiographic film have also been used to obtain surface dose measurements. The diamond detector was used recently by the author in an investigation on the effects of beam-modifying devices on skin dose and it is also described in this report

  19. Classifying Scenarios in a Product Design Process: a study to achieve automated scenario generation

    NARCIS (Netherlands)

    Anggreeni, Irene; van der Voort, Mascha C.; van Houten, F.J.A.M.; Miedema, J.; Lutters, D.

    2008-01-01

    This paper explains the possible uses of scenarios in product design. A scenario classification is proposed as a framework to create, use and reuse different types of scenarios in a product design process. Our aims are three-fold: (1) to obtain a better view on the extent to which scenarios can be

  20. Surfaces electrons at dielectric plasma walls

    International Nuclear Information System (INIS)

    Heinisch, Rafael Leslie

    2013-01-01

    The concept of the electron surface layer introduced in this thesis provides a framework for the description of the microphysics of the surplus electrons immediately at the wall and thereby complements the modelling of the plasma sheath. In this work we have considered from a surface physics perspective the distribution and build-up of an electron adsorbate on the wall as well as the effect of the negative charge on the scattering of light by a spherical particle immersed in a plasma. In our electron surface layer model we treat the wall-bound electrons as a wall-thermalised electron distribution minimising the grand canonical potential and satisfying Poisson's equation. The boundary between the electron surface layer and the plasma sheath is determined by a force balance between the attractive image potential and the repulsive sheath potential and lies in front of the crystallographic interface. Depending on the electron affinity χ, that is the offset of the conduction band minimum to the potential in front of the surface, two scenarios for the wall-bound electrons are realised. For χ 0 electrons penetrate into the conduction band where they form an extended space charge. These different scenarios are also reflected in the electron kinetics at the wall which control the sticking coefficient and the desorption time. If χ -3 . For χ>0 electron physisorption takes place in the conduction band. For this case sticking coefficients and desorption times have not been calculated yet but in view of the more efficient scattering with bulk phonons, responsible for electron energy relaxation in this case, we expect them to be larger than for the case of χ 0 the electrons in the bulk of the particle modify the refractive index through their bulk electrical conductivity. In both cases the conductivity is limited by scattering with surface or bulk phonons. Surplus electrons lead to an increase of absorption at low frequencies and, most notably, to a blue-shift of an

  1. Primary water chemistry monitoring from the point of view of radiation build-up

    International Nuclear Information System (INIS)

    Horvath, G.L.; Civin, V.; Pinter, T.

    1997-01-01

    Basic operational principles of a computer code system calculating the primary circuit corrosion product activities based on actual measured plant chemistry data are presented. The code system consists of two parts: FeSolub.prg: calculates the characteristic iron solubilities based on actual primary water chemistry (H 3 BO 3 KOH, ... etc.) and plant load (MW) data. A developed solubility calculation method has been applied fitted to magnetite solubility data of several authors; RADTRAN.exe: calculates primary circuit water and surface corrosion product activities based on results of FeSolub.prg or planned water chemistry data up to the next shutdown. The computer code system is going to be integrated into a general primary water chemistry monitoring and surveillance system. (author). 15 refs, 4 figs, 3 tabs

  2. Primary water chemistry monitoring from the point of view of radiation build-up

    Energy Technology Data Exchange (ETDEWEB)

    Horvath, G L [Institute for Electrical Power Research, Budapest (Hungary); Civin, V [Hungarian Electricity Generating Board, Budapest (Hungary); Pinter, T [Nuclear Power Plant PAKS, Budapest (Hungary)

    1997-02-01

    Basic operational principles of a computer code system calculating the primary circuit corrosion product activities based on actual measured plant chemistry data are presented. The code system consists of two parts: FeSolub.prg: calculates the characteristic iron solubilities based on actual primary water chemistry (H{sub 3}BO{sub 3}KOH, ... etc.) and plant load (MW) data. A developed solubility calculation method has been applied fitted to magnetite solubility data of several authors; RADTRAN.exe: calculates primary circuit water and surface corrosion product activities based on results of FeSolub.prg or planned water chemistry data up to the next shutdown. The computer code system is going to be integrated into a general primary water chemistry monitoring and surveillance system. (author). 15 refs, 4 figs, 3 tabs.

  3. ITER safety and operational scenario

    International Nuclear Information System (INIS)

    Shimomura, Y.; Saji, G.

    1998-01-01

    The safety and environmental characteristics of ITER and its operational scenario are described. Fusion has built-in safety characteristics without depending on layers of safety protection systems. Safety considerations are integrated in the design by making use of the intrinsic safety characteristics of fusion adequate to the moderate hazard inventories. In addition to this, a systematic nuclear safety approach has been applied to the design of ITER. The safety assessment of the design shows how ITER will safely accommodate uncertainties, flexibility of plasma operations, and experimental components, which is fundamental in ITER, the first experimental fusion reactor. The operation of ITER will progress step by step from hydrogen plasma operation with low plasma current, low magnetic field, short pulse and low duty factor without fusion power to deuterium-tritium plasma operation with full plasma current, full magnetic field, long pulse and high duty factor with full fusion power. In each step, characteristics of plasma and optimization of plasma operation will be studied which will significantly reduce uncertainties and frequency/severity of plasma transient events in the next step. This approach enhances reliability of ITER operation. (orig.)

  4. Project scenarios for bitumen upgrading

    International Nuclear Information System (INIS)

    Koppel, P.E.; Mazurek, W.L.; Harji, A.

    2002-01-01

    The established reserves of Alberta's heavy oil resources are 178 billion barrels, and potential recoverable reserves are 315 billion barrels. The challenge of production includes the logistics of recovery, upgrading and transportation to market. Utilization of the bitumen is not simple because bitumen is too viscous to transport by pipeline. In addition, it is not processable by most existing refineries unless it can be upgraded through dilution. This paper examined different factors regarding the economic viability of various upgrading methods of a wide range of bitumen feedstocks. The study also examined the sensitivity of refinery demand to the prices of these feedstocks, along with the competitiveness among bitumen-based feedstock and conventional crudes. Western Canada, Ontario and the PADD II district in the United States are the 3 major markets for western Canadian bitumen based feedstock, the demand for which depends on refinery configurations and asphalt demand. This paper described the following 4 generic scenarios that describe Alberta bitumen upgrading projects: (1) adjacent to open pit mines, (2) adjacent to steam assisted gravity drainage (SAGD) facilities, (3) remotely located from resource production at an existing refinery, and (4) pipeline bitumen. It was noted that producers should determine the best way to upgrade the bitumen to ensure there is an economic market for the product, but they should also be aware not to over process the bitumen so as not to leave existing refinery facilities under-utilized. 2 refs., 1 tab., 3 figs

  5. IPCC Special report on Emissions Scenarios (SRES)

    International Nuclear Information System (INIS)

    Anon

    2001-01-01

    This special report on emissions scenarios (SRES) is intended to reflect the most recent trends in driving forces of emissions; population projections economic development, and structural and technological change. It serves as an update to IS92 scenarios developed by IPCC in the early 1990s to illustrate a plausible range of future greenhouse gas emissions. This update is based on a review of the literature and the development of a database of over 400 global and regional scenarios; 190 of these extend from 1900 to 2100 and thus fed into the development of the narrative scenarios and storylines. Based on the literature review, a set of four alternative scenario families, having a total of 40 emission scenarios have been developed. Each scenario family includes a narrative storyline which describes a demographic, social. economic, technological, environmental and policy future. Characteristic features of each of the four families are summarized and a comparison is made between the IS92 and SRES. One of the main conclusions of this recent scenario construction effort is the realization that alternative combinations of main scenario driving forces can lead to similar levels of GHG emissions by the end of the 21st century, and that scenarios with different underlying assumptions can result in very similar climate change

  6. Generation of point isotropic source dose buildup factor data for the PFBR special concretes in a form compatible for usage in point kernel computer code QAD-CGGP

    International Nuclear Information System (INIS)

    Radhakrishnan, G.

    2003-01-01

    Full text: Around the PFBR (Prototype Fast Breeder Reactor) reactor assembly, in the peripheral shields special concretes of density 2.4 g/cm 3 and 3.6 g/cm 3 are to be used in complex geometrical shapes. Point-kernel computer code like QAD-CGGP, written for complex shield geometry comes in handy for the shield design optimization of peripheral shields. QAD-CGGP requires data base for the buildup factor data and it contains only ordinary concrete of density 2.3 g/cm 3 . In order to extend the data base for the PFBR special concretes, point isotropic source dose buildup factors have been generated by Monte Carlo method using the computer code MCNP-4A. For the above mentioned special concretes, buildup factor data have been generated in the energy range 0.5 MeV to 10.0 MeV with the thickness ranging from 1 mean free paths (mfp) to 40 mfp. Capo's formula fit of the buildup factor data compatible with QAD-CGGP has been attempted

  7. Development of an ash particle deposition model considering build-up and removal mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Strandstroem, Kjell; Mueller, Christian; Hupa, Mikko [Aabo Akademi Process Chemistry Centre, Biskopsgatan 8, FI-20500 Aabo (Finland)

    2007-12-15

    Slagging and fouling on heat exchanger surfaces in power boilers fired with fossil fuels and fuel mixtures has a significant influence on boiler efficiency and availability. Mathematical modelling is since long considered a suitable method to assist boiler operators to determine optimized operating conditions for an existing furnace. The ultimate goal in ash deposition prediction is hereby the determination of the total amount of material deposited and hence the determination of the total reduction in efficiency. Depending on the fuels fired the total deposited mass is a combination of ash particle deposition and ash particle erosion due to non-sticky particles. The novel ash particle deposition model presented in this work considers deposition of sticky ash particles, cleansing of deposit by non-sticky sand particles and sticking of sand due to contact with sticky ash. The steady-state modelling results for the total amount of ash deposited on the deposition probe of an entrained flow reactor presented in this work agree well with the experimental data. Only at very high fractions of sand added as non-sticky material, a significant influence of the sand on the overall mass deposited was found. Since the model considers sticking of non-sticking sand due to contact with sticky ash, the fraction of sand deposited on the probe was especially studied. Using a correction factor to consider the influence of operating time on the steady-state simulations led to good agreement between simulations and experimental data. (author)

  8. Development of an ash particle deposition model considering build-up and removal mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Kjell Strandstroem; Christian Muellera; Mikko Hupa [Abo Akademi Process Chemistry Centre, Abo (Finland)

    2007-12-15

    Slagging and fouling on heat exchanger surfaces in power boilers fired with fossil fuels and fuel mixtures has a significant influence on boiler efficiency and availability. Mathematical modelling has long been considered a suitable method to assist boiler operators to determine optimized operating conditions for an existing furnace. The ultimate goal in ash deposition prediction is hereby the determination of the total amount of material deposited and hence the determination of the total reduction in efficiency. Depending on the fuels fired the total deposited mass is a combination of ash particle deposition and ash particle erosion due to non-sticky particles. The novel ash particle deposition model presented in this work considers deposition of sticky ash particles, cleansing of deposit by non-sticky sand particles and sticking of sand due to contact with sticky ash. The steady-state modelling results for the total amount of ash deposited on the deposition probe of an entrained flow reactor presented in this work agree well with the experimental data. Only at very high fractions of sand added as non-sticky material, a significant influence of the sand on the overall mass deposited was found. Since the model considers sticking of non-sticking sand due to contact with sticky ash, the fraction of sand deposited on the probe was especially studied. Using a correction factor to consider the influence of operating time on the steady-state simulations led to good agreement between simulations and experimental data. 12 refs., 10 figs.

  9. A study of build-up effects in high-energy radiation fields using a TEPC

    Energy Technology Data Exchange (ETDEWEB)

    Hoefert, M; Stevenson, G R [CERN, European Laboratory for Particle Physics, Geneva (Switzerland); Aroua, A [IAR, Institute for Applied Radiophysics, Lausanne (Switzerland); Sannikov, A V [IHEP, Institute for High-Energy Physics, Protvino (Russian Federation)

    1995-09-04

    A dose of 2 mSv close to the body surface of a pregnant woman is considered by ICRP to assure a dose limit of 1 mSv to the foetus. Such an assumption depends on the energy spectrum and composition of the external radiation field and it was tested in radiation fields containing high-energy particles similar to those found around high-energy particle accelerators and in air-craft. Measurements of dose and dose equivalent were performed as a function of wall thickness using a tissue-equivalent proportional counter (TEPC) in radiation fields at the CERN-EU Reference Radiation Facility. Results are presented both with respect to integral quantities and event size spectra. The decrease in dose and dose equivalent at a depth equivalent to that of the foetus was typically 10% in a high-energy stray radiation field and in the case of PuBe source neutrons amounted to only 30%. It is concluded that it would be prudent under such exposure conditions to limit the dose of a pregnant woman to 1 mSv in order to assure that the dose to the foetus remains below the same limit. (author)

  10. A study of build-up effects in high-energy radiation fields using a TEPC

    International Nuclear Information System (INIS)

    Hoefert, M.; Stevenson, G.R.; Aroua, A.; Sannikov, A.V.

    1995-01-01

    A dose of 2 mSv close to the body surface of a pregnant woman is considered by ICRP to assure a dose limit of 1 mSv to the foetus. Such an assumption depends on the energy spectrum and composition of the external radiation field and it was tested in radiation fields containing high-energy particles similar to those found around high-energy particle accelerators and in air-craft. Measurements of dose and dose equivalent were performed as a function of wall thickness using a tissue-equivalent proportional counter (TEPC) in radiation fields at the CERN-EU Reference Radiation Facility. Results are presented both with respect to integral quantities and event size spectra. The decrease in dose and dose equivalent at a depth equivalent to that of the foetus was typically 10% in a high-energy stray radiation field and in the case of PuBe source neutrons amounted to only 30%. It is concluded that it would be prudent under such exposure conditions to limit the dose of a pregnant woman to 1 mSv in order to assure that the dose to the foetus remains below the same limit. (author)

  11. An investigation of build-up effects in high energy radiation fields using a Handi TEPC

    International Nuclear Information System (INIS)

    Aroua, A.; Sannikov, A.V.

    1995-01-01

    ICRP considers that a dose limit of 2 mSv close to the body surface of a pregnant woman will ensure a dose limit of 1 mSv to the foetus. This assumption depends on the energy spectrum and composition of the radiation fields, especially those containing high energy particles such as are found around particle accelerators or in aircraft. In this work the response of a tissue-equivalent proportional counter in radiation fields of different composition and energy was measured as a function of depth in cylindrical phantoms. The decrease in dose and dose equivalent at a phantom depth equivalent to that of a foetus was 10% in a typical high energy stray radiation field and 30% for neutrons from a Pu-Be source. It is concluded that it would be prudent in these cases to limit the exposure of a pregnant woman to 1 mSv in order to ensure that the dose to the foetus stays below the same limit. (Author)

  12. Scenario analysis for integrated water resources planning and management under uncertainty in the Zayandehrud river basin

    Science.gov (United States)

    Safavi, Hamid R.; Golmohammadi, Mohammad H.; Sandoval-Solis, Samuel

    2016-08-01

    The goal of this study is to develop and analyze three scenarios in the Zayandehrud river basin in Iran using a model already built and calibrated by Safavi et al. (2015) that has results for the baseline scenario. Results from the baseline scenario show that water demands will be supplied at the cost of depletion of surface and ground water resources, making this scenario undesirable and unsustainable. Supply Management, Demand Management, and Meta (supply and demand management) scenarios are the selected scenarios in this study. They are to be developed and declared into the Zayandehrud model to assess and evaluate the imminent status of the basin. Certain strategies will be employed for this purpose to improve and rectify the current management policies. The five performance criteria of time-based and volumetric reliability, resilience, vulnerability, and maximum deficit will be employed in the process of scenario analysis and evaluation. The results obtained from the performance criteria will be summed up into a so-called 'Water Resources Sustainability Index' to facilitate comparison among the likely trade-offs. Uncertainties arising from historical data, management policies, rainfall-runoff model, demand priorities, and performance criteria are considered in the proposed conceptual framework and modeled by appropriate approaches. Results show that the Supply Management scenario can be used to improve upon the demand supply but that it has no tangible effects on the improvement of the resources in the study region. In this regard, the Demand Management scenario is found to be more effective than the water supply one although it still remains unacceptable. Results of the Meta scenario indicate that both the supply and demand management scenarios must be applied if the water resources are to be safeguarded against degradation and depletion. In other words, the supply management scenario is necessary but not adequate; rather, it must be coupled to the demand

  13. CIEMAT analyses of transition fuel cycle scenarios

    International Nuclear Information System (INIS)

    Alvarez-Velarde, F.; Gonzalez-Romero, E.M.

    2010-01-01

    The efficient design of strategies for the long-term sustainability of nuclear energy or the phase-out of this technology is possible after the study of transition scenarios from the current fuel cycle to a future one with advanced technologies and concepts. CIEMAT has participated in numerous fuel cycle scenarios studies for more than a decade and, from some years ago, special attention has been put in the study of transition scenarios. In this paper, the main characteristics of each studied transition scenario are described. The main results and partial conclusions of each scenario are also analyzed. As general conclusions of transition studies, we highlight that the advantages of advanced technologies in transition scenarios can be obtained by countries or regions with sufficiently large nuclear parks, with a long-term implementation of the strategy. For small countries, these advantages are also accessible with an affordable cost, by means of the regional collaboration during several decades. (authors)

  14. MIOSAT Mission Scenario and Design

    Science.gov (United States)

    Agostara, C.; Dionisio, C.; Sgroi, G.; di Salvo, A.

    2008-08-01

    MIOSAT ("Mssione Ottica su microSATellite") is a low-cost technological / scientific microsatellite mission for Earth Observation, funded by Italian Space Agency (ASI) and managed by a Group Agreement between Rheinmetall Italia - B.U. Spazio - Contraves as leader and Carlo Gavazzi Space as satellite manufacturer. Several others Italians Companies, SME and Universities are involved in the development team with crucial roles. MIOSAT is a microsatellite weighting around 120 kg and placed in a 525 km altitude sun-synchronuos circular LEO orbit. The microsatellite embarks three innovative optical payloads: Sagnac multi spectral radiometer (IFAC-CNR), Mach Zehender spectrometer (IMM-CNR), high resolution pancromatic camera (Selex Galileo). In addition three technological experiments will be tested in-flight. The first one is an heat pipe based on Marangoni effect with high efficiency. The second is a high accuracy Sun Sensor using COTS components and the last is a GNSS SW receiver that utilizes a Leon2 processor. Finally a new generation of 28% efficiency solar cells will be adopted for the power generation. The platform is highly agile and can tilt along and cross flight direction. The pointing accuracy is in the order of 0,1° for each axe. The pointing determination during images acquisition is <0,02° for the axis normal to the boresight and 0,04° for the boresight. This paper deals with MIOSAT mission scenario and definition, highlighting trade-offs for mission implementation. MIOSAT mission design has been constrained from challenging requirements in terms of satellite mass, mission lifetime, instrument performance, that have implied the utilization of satellite agility capability to improve instruments performance in terms of S/N and resolution. The instruments provide complementary measurements that can be combined in effective ways to exploit new applications in the fields of atmosphere composition analysis, Earth emissions, antropic phenomena, etc. The Mission

  15. COMPETITIVE INTELLIGENCE ANALYSIS - SCENARIOS METHOD

    Directory of Open Access Journals (Sweden)

    Ivan Valeriu

    2014-07-01

    Full Text Available Keeping a company in the top performing players in the relevant market depends not only on its ability to develop continually, sustainably and balanced, to the standards set by the customer and competition, but also on the ability to protect its strategic information and to know in advance the strategic information of the competition. In addition, given that economic markets, regardless of their profile, enable interconnection not only among domestic companies, but also between domestic companies and foreign companies, the issue of economic competition moves from the national economies to the field of interest of regional and international economic organizations. The stakes for each economic player is to keep ahead of the competition and to be always prepared to face market challenges. Therefore, it needs to know as early as possible, how to react to others’ strategy in terms of research, production and sales. If a competitor is planning to produce more and cheaper, then it must be prepared to counteract quickly this movement. Competitive intelligence helps to evaluate the capabilities of competitors in the market, legally and ethically, and to develop response strategies. One of the main goals of the competitive intelligence is to acknowledge the role of early warning and prevention of surprises that could have a major impact on the market share, reputation, turnover and profitability in the medium and long term of a company. This paper presents some aspects of competitive intelligence, mainly in terms of information analysis and intelligence generation. Presentation is theoretical and addresses a structured method of information analysis - scenarios method – in a version that combines several types of analysis in order to reveal some interconnecting aspects of the factors governing the activity of a company.

  16. Acetone as biomarker for ketosis buildup capability--a study in healthy individuals under combined high fat and starvation diets.

    Science.gov (United States)

    Prabhakar, Amlendu; Quach, Ashley; Zhang, Haojiong; Terrera, Mirna; Jackemeyer, David; Xian, Xiaojun; Tsow, Francis; Tao, Nongjian; Forzani, Erica S

    2015-04-22

    Ketogenic diets are high fat and low carbohydrate or very low carbohydrate diets, which render high production of ketones upon consumption known as nutritional ketosis (NK). Ketosis is also produced during fasting periods, which is known as fasting ketosis (FK). Recently, the combinations of NK and FK, as well as NK alone, have been used as resources for weight loss management and treatment of epilepsy. A crossover study design was applied to 11 healthy individuals, who maintained moderately sedentary lifestyle, and consumed three types of diet randomly assigned over a three-week period. All participants completed the diets in a randomized and counterbalanced fashion. Each weekly diet protocol included three phases: Phase 1 - A mixed diet with ratio of fat: (carbohydrate + protein) by mass of 0.18 or the equivalence of 29% energy from fat from Day 1 to Day 5. Phase 2- A mixed or a high-fat diet with ratio of fat: (carbohydrate + protein) by mass of approximately 0.18, 1.63, or 3.80 on Day 6 or the equivalence of 29%, 79%, or 90% energy from fat, respectively. Phase 3 - A fasting diet with no calorie intake on Day 7. Caloric intake from diets on Day 1 to Day 6 was equal to each individual's energy expenditure. On Day 7, ketone buildup from FK was measured. A statistically significant effect of Phase 2 (Day 6) diet was found on FK of Day 7, as indicated by repeated analysis of variance (ANOVA), F(2,20) = 6.73, p fat content and 90% fat content vs. 29% fat content (with p = 0.00159**, and 0.04435**, respectively), with no significant difference between diets with 79% fat content and 90% fat content. In addition, independent of the diet, a significantly higher ketone buildup capability of subjects with higher resting energy expenditure (R(2) = 0.92), and lower body mass index (R(2) = 0.71) was observed during FK.

  17. Action research Toolkit II: The Scenario Workshop

    DEFF Research Database (Denmark)

    Rasmussen, Lauge Baungaard

    2003-01-01

    The article describes the scenario workshop within the action research paradigm. In addtion, the maina phases and the functions of the facilitator and the participants are outlined. Finally,it describes and analyses the experiences of using the scenario workshop in practice.......The article describes the scenario workshop within the action research paradigm. In addtion, the maina phases and the functions of the facilitator and the participants are outlined. Finally,it describes and analyses the experiences of using the scenario workshop in practice....

  18. Comparison of future energy scenarios for Denmark

    DEFF Research Database (Denmark)

    Kwon, Pil Seok; Østergaard, Poul Alberg

    2012-01-01

    Scenario-making is becoming an important tool in energy policy making and energy systems analyses. This article probes into the making of scenarios for Denmark by presenting a comparison of three future scenarios which narrate 100% renewable energy system for Denmark in 2050; IDA 2050, Climate...... Commission 2050, and CEESA (Coherent Energy and Environmental System Analysis). Generally, although with minor differences, the scenarios suggest the same technological solutions for the future such as expansion of biomass usage and wind power capacity, integration of transport sector into the other energy...

  19. Visualizing Risks: Icons for Information Attack Scenarios

    National Research Council Canada - National Science Library

    Hosmer, Hilary

    2000-01-01

    .... Visual attack scenarios help defenders see system ambiguities, imprecision, vulnerabilities and omissions, thus speeding up risk analysis, requirements gathering, safeguard selection, cryptographic...

  20. Energy scenarios for Colombia: process and content

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Ricardo A. [National Univ. of Colombia, Escuela de Geosciencias y Medio Ambiente, Medellin (Colombia); Vesga, Daniel R.A. [Unidad de Planeacion Minero Energetica, Bogota (Colombia); Cadena, Angela I. [Los Andes Univ., School of Engineering, Bogota (Colombia); Boman, Ulf [Kairos Future AB, Stockholm (Sweden); Larsen, Erik [Cass Business School, London (United Kingdom); Dyner, Isaac [Universidad Nacional de Colombia, Energy Inst., Medellin (Colombia)

    2005-02-01

    This paper presents the approach undertaken, and the four energy scenarios that have been developed, to support long term energy policy in Colombia. The scenarios were constructed with emphasis on maximum interaction between stakeholders in the Colombian energy sector. The process directly involved over 120 people. The scenarios were developed as strategic support tools for the Energy and Mining Planning Unit (UPME), which is the Colombian institution in charge of developing the country's energy strategies and National Energy Policy. The methodology employed is presented, followed by a detailed description of each of the four scenarios. (Author)

  1. Injection heating scenarios for TNS

    International Nuclear Information System (INIS)

    Rome, J.A.; Peng, Y.K.M.; Holmes, J.A.

    1977-07-01

    Neutral beam injection heating is a prime contender for heating TNS. However, injection into a full bore high density plasma during start-up will not give adequate beam penetration even with deuteron energies up to 300 keV and Z/sub eff/ < 1.5. But low density start-up may be feasible with deuteron energies of approximately 150 keV if advantage is taken of the α-heating and flux surface shifts which occur when β is increased

  2. Climate mitigation scenarios of drained peat soils

    Science.gov (United States)

    Kasimir Klemedtsson, Åsa; Coria, Jessica; He, Hongxing; Liu, Xiangping; Nordén, Anna

    2014-05-01

    The national inventory reports (NIR) submitted to the UNFCCC show Sweden - which as many other countries has wetlands where parts have been drained for agriculture and forestry purposes, - to annually emit 12 million tonnes carbon dioxide equivalents, which is more GHG'es than industrial energy use release in Sweden. Similar conditions can be found in other northern countries, having cool and wet conditions, naturally promoting peat accumulation, and where land use management over the last centuries have promoted draining activities. These drained peatland, though covering only 2% of the land area, have emissions corresponding to 20% of the total reported NIR emissions. This substantial emission contribution, however, is hidden within the Land Use Land Use Change and Forestry sector (LULUCF) where the forest Carbon uptake is even larger, which causes the peat soil emissions become invisible. The only drained soil emission accounted in the Swedish Kyoto reporting is the N2O emission from agricultural drained organic soils of the size 0.5 million tonnes CO2e yr-1. This lack of visibility has made incentives for land use change and management neither implemented nor suggested, however with large potential. Rewetting has the potential to decrease soil mineralization, why CO2 and N2O emissions are mitigated. However if the soil becomes very wet CH4 emission will increase together with hampered plant growth. By ecological modeling, using the CoupModel the climate change mitigation potential have been estimated for four different land use scenarios; 1, Drained peat soil with Spruce (business as usual scenario), 2, raised ground water level to 20 cm depth and Willow plantation, 3, raised ground water level to 10 cm depth and Reed Canary Grass, and 4, rewetting to an average water level in the soil surface with recolonizing wetland plants and mosses. We calculate the volume of biomass production per year, peat decomposition, N2O emission together with nitrate and DOC

  3. Build-up of the silicon micro-strip detector array in ETF of HIRFL-CSR

    International Nuclear Information System (INIS)

    Wang Pengfei; Li Zhankui; Li Haixia

    2014-01-01

    Silicon micro-strip detectors have been widely used in the world-famous nuclear physics laboratories due to their better position resolution and energy resolution. Double-sided silicon micro-strip detectors with a position resolution of 0.5 mm × 0.5 mm, have been fabricated in the IMP (Institute of Modern Physics, CAS) by using microelectronics technology. These detectors have been used in the ETF (External Target Facility) of HIRFL-CSR, as ΔE detectors of the ΔE-E telescope system and the track detectors. With the help of flexibility printed circuit board (FPCB) and the integrated ASIC chips, a compact multi-channel front-end electronic board has been designed to fulfill the acquisition of the energy and position information of the Silicon micro-strip detectors. It is described in this paper that the build-up of the Silicon micro-strip detector array in ETF of HIRFL-CSR, the determination of the energy resolution of the detector units, and the energy resolution of approximately 1% obtained for 5∼9 MeV α particles in vacuum. (authors)

  4. Determination of neutron buildup factor using analytical solution of one-dimensional neutron diffusion equation in cylindrical geometry

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Julio Cesar L.; Vilhena, Marco Tullio, E-mail: julio.lombaldo@ufrgs.b, E-mail: vilhena@pq.cnpq.b [Universidade Federal do Rio Grande do Sul (DMPA/UFRGS), Porto Alegre, RS (Brazil). Dept. de Matematica Pura e Aplicada. Programa de Pos Graduacao em Matematica Aplicada; Borges, Volnei; Bodmann, Bardo Ernest, E-mail: bardo.bodmann@ufrgs.b, E-mail: borges@ufrgs.b [Universidade Federal do Rio Grande do Sul (PROMEC/UFRGS), Porto Alegre, RS (Brazil). Programa de Pos-Graduacao em Engenharia Mecanica

    2011-07-01

    The principal idea of this work, consist on formulate an analytical method to solved problems for diffusion of neutrons with isotropic scattering in one-dimensional cylindrical geometry. In this area were develop many works that study the same problem in different system of coordinates as well as cartesian system, nevertheless using numerical methods to solve the shielding problem. In view of good results in this works, we starting with the idea that we can represent a source in the origin of the cylindrical system by a Delta Dirac distribution, we describe the physical modeling and solved the neutron diffusion equation inside of cylinder of radius R. For the case of transport equation, the formulation of discrete ordinates S{sub N} consists in discretize the angular variables in N directions and in using a quadrature angular set for approximate the sources of scattering, where the Diffusion equation consist on S{sub 2} approximated transport equation in discrete ordinates. We solved the neutron diffusion equation with an analytical form by the finite Hankel transform. Was presented also the build-up factor for the case that we have neutron flux inside the cylinder. (author)

  5. Post and core build-ups in crown and bridge abutments: Bio-mechanical advantages and disadvantages.

    Science.gov (United States)

    Mamoun, John

    2017-06-01

    Dentists often place post and core buildups on endodontically treated abutments for crown and bridge restorations. This article analyzes the bio-mechanical purposes, advantages and disadvantages of placing a core or a post and core in an endodontically treated tooth and reviews literature on post and core biomechanics. The author assesses the scientific rationale of the claim that the main purpose of a post is to retain a core, or the claim that posts weaken teeth. More likely, the main function of a post is to help prevent the abutment, on which a crown is cemented, from fracturing such that the abutment separates from the tooth root, at a fracture plane that is located approximately and theoretically at the level of the crown (or ferrule) margin. A post essentially improves the ferrule effect that is provided by the partial fixed denture prosthesis. This paper also explores the difference between bio-mechanical failures of crowns caused by lack of retention or excess taper, versus failures due to a sub-optimal ferrule effect in crown and bridge prostheses.

  6. DC Model Cable under Polarity Inversion and Thermal Gradient: Build-Up of Design-Related Space Charge

    Directory of Open Access Journals (Sweden)

    Nugroho Adi

    2017-07-01

    Full Text Available In the field of energy transport, High-Voltage DC (HVDC technologies are booming at present due to the more flexible power converter solutions along with needs to bring electrical energy from distributed production areas to consumption sites and to strengthen large-scale energy networks. These developments go with challenges in qualifying insulating materials embedded in those systems and in the design of insulations relying on stress distribution. Our purpose in this communication is to illustrate how far the field distribution in DC insulation systems can be anticipated based on conductivity data gathered as a function of temperature and electric field. Transient currents and conductivity estimates as a function of temperature and field were recorded on miniaturized HVDC power cables with construction of 1.5 mm thick crosslinked polyethylene (XLPE insulation. Outputs of the conductivity model are compared to measured field distributions using space charge measurements techniques. It is shown that some features of the field distribution on model cables put under thermal gradient can be anticipated based on conductivity data. However, space charge build-up can induce substantial electric field strengthening when materials are not well controlled.

  7. Determination of neutron buildup factor using analytical solution of one-dimensional neutron diffusion equation in cylindrical geometry

    International Nuclear Information System (INIS)

    Fernandes, Julio Cesar L.; Vilhena, Marco Tullio; Borges, Volnei; Bodmann, Bardo Ernest

    2011-01-01

    The principal idea of this work, consist on formulate an analytical method to solved problems for diffusion of neutrons with isotropic scattering in one-dimensional cylindrical geometry. In this area were develop many works that study the same problem in different system of coordinates as well as cartesian system, nevertheless using numerical methods to solve the shielding problem. In view of good results in this works, we starting with the idea that we can represent a source in the origin of the cylindrical system by a Delta Dirac distribution, we describe the physical modeling and solved the neutron diffusion equation inside of cylinder of radius R. For the case of transport equation, the formulation of discrete ordinates S N consists in discretize the angular variables in N directions and in using a quadrature angular set for approximate the sources of scattering, where the Diffusion equation consist on S 2 approximated transport equation in discrete ordinates. We solved the neutron diffusion equation with an analytical form by the finite Hankel transform. Was presented also the build-up factor for the case that we have neutron flux inside the cylinder. (author)

  8. Decomposition of litter and soil organic matter - Can we distinguish a mechanism for soil organic matter buildup ?

    International Nuclear Information System (INIS)

    Berg, B.; Johansson, M.B.; McClaugherty, C.; Virzo de Santo, A.; Ekbohm, G.

    1995-01-01

    This synthesis paper presents a model for estimating the buildup of soil organic matter in various types of coniferous forests. The knowledge used was obtained from a well-studied forest with good litterfall data, decomposition information and validation measurements of the soil organic matter layer. By constructing a simple model for litterfall, and the information on maximum decomposition levels for litter, we could estimate the annual increase in soil organic matter and extend this to encompass stand age. The validation measurement and the estimated amount of soil organic matter differed by about 8 or 26% over a 120-yr period, depending on the litterfall model. The estimated increased storage of soil organic matter as a consequence of climate change was found to be drastic. We thus found that the soil organic matter layer would grow about four times as fast as a result of the needle component only. This estimate was based on a comparison between latitudes with a difference of 17 degrees. 35 refs, 7 figs, 3 tabs

  9. Evaluating the Hydrologic Performance of Low Impact Development Scenarios in a Micro Urban Catchment

    Science.gov (United States)

    Li, Chunlin; Liu, Miao; Hu, Yuanman; Han, Rongqing; Shi, Tuo; Qu, Xiuqi; Wu, Yilin

    2018-01-01

    As urbanization progresses, increasingly impervious surfaces have changed the hydrological processes in cities and resulted in a major challenge for urban stormwater control. This study uses the urban stormwater model to evaluate the performance and costs of low impact development (LID) scenarios in a micro urban catchment. Rainfall-runoff data of three rainfall events were used for model calibration and validation. The pre-developed (PreDev) scenario, post-developed (PostDev) scenario, and three LID scenarios were used to evaluate the hydrologic performance of LID measures. Using reduction in annual runoff as the goal, the best solutions for each LID scenario were selected using cost-effectiveness curves. The simulation results indicated that the three designed LID scenarios could effectively reduce annual runoff volumes and pollutant loads compared with the PostDev scenario. The most effective scenario (MaxPerf) reduced annual runoff by 53.4%, followed by the sponge city (SpoPerf, 51.5%) and economy scenarios (EcoPerf, 43.1%). The runoff control efficiency of the MaxPerf and SpoPerf scenarios increased by 23.9% and 19.5%, respectively, when compared with the EcoPerf scenario; however, the costs increased by 104% and 83.6%. The reduction rates of four pollutants (TSS, TN, TP, and COD) under the MaxPerf scenario were 59.8–61.1%, followed by SpoPerf (53.9–58.3%) and EcoPerf (42.3–45.4%), and the costs of the three scenarios were 3.74, 3.47 and 1.83 million yuan, respectively. These results can provide guidance to urban stormwater managers in future urban planning to improve urban water security. PMID:29401747

  10. Two graphical user interfaces for managing and analyzing MODFLOW groundwater-model scenarios

    Science.gov (United States)

    Banta, Edward R.

    2014-01-01

    Scenario Manager and Scenario Analyzer are graphical user interfaces that facilitate the use of calibrated, MODFLOW-based groundwater models for investigating possible responses to proposed stresses on a groundwater system. Scenario Manager allows a user, starting with a calibrated model, to design and run model scenarios by adding or modifying stresses simulated by the model. Scenario Analyzer facilitates the process of extracting data from model output and preparing such display elements as maps, charts, and tables. Both programs are designed for users who are familiar with the science on which groundwater modeling is based but who may not have a groundwater modeler’s expertise in building and calibrating a groundwater model from start to finish. With Scenario Manager, the user can manipulate model input to simulate withdrawal or injection wells, time-variant specified hydraulic heads, recharge, and such surface-water features as rivers and canals. Input for stresses to be simulated comes from user-provided geographic information system files and time-series data files. A Scenario Manager project can contain multiple scenarios and is self-documenting. Scenario Analyzer can be used to analyze output from any MODFLOW-based model; it is not limited to use with scenarios generated by Scenario Manager. Model-simulated values of hydraulic head, drawdown, solute concentration, and cell-by-cell flow rates can be presented in display elements. Map data can be represented as lines of equal value (contours) or as a gradated color fill. Charts and tables display time-series data obtained from output generated by a transient-state model run or from user-provided text files of time-series data. A display element can be based entirely on output of a single model run, or, to facilitate comparison of results of multiple scenarios, an element can be based on output from multiple model runs. Scenario Analyzer can export display elements and supporting metadata as a Portable

  11. Toward Managing & Automating CyberCIEGE Scenario Definition File Creation

    National Research Council Canada - National Science Library

    Johns, Kenneth

    2004-01-01

    .... These scenarios are written CyberCIEGE Scenarios Definition Language. Unfortunately, the trade-off for flexibility, extendibility and fully customizable Scenarios is syntax complexity in the Scenarios definition language...

  12. Evaluation Framework for Dependable Mobile Learning Scenarios

    Science.gov (United States)

    Bensassi, Manel; Laroussi, Mona

    2014-01-01

    The goal of the dependability analysis is to predict inconsistencies and to reveal ambiguities and incompleteness in the designed learning scenario. Evaluation, in traditional learning design, is generally planned after the execution of the scenario. In mobile learning, this stage becomes too difficult and expensive to apply due to the complexity…

  13. Elaborating SRES scenarios for nuclear energy

    International Nuclear Information System (INIS)

    McDonald, Alan; Riahi, Keywan; Rogner, Hans-Holger

    2003-01-01

    The objective of this paper is identifying mid-century economic targets for nuclear energy. The first step is to describe what the mid-century energy market might look like: the major competitors for nuclear energy, what products are in demand, how much of each, where is growth greatest, and so forth. The mechanism for systematically describing the future market is scenario building. The starting point is the scenarios in the Special Report on Emissions Scenarios (SRES) of the Intergovernmental Panel on Climate Change. SRES developed four narrative story lines, each representing a different coherent set of demographic, social, economic, technological, and environmental developments. For each story line several different scenarios were developed by six international modelling teams, resulting in 40 scenarios grouped in the 4 story lines. For three of the story lines this paper uses a single marker scenario representative of central tendencies within the scenario family. For the fourth story line the authors chose the scenario that assumes that advances in non-fossil technologies - renewable, nuclear, and high-efficiency conservation technologies - make them most cost-competitive. (BA)

  14. Some issues in the ghost condensation scenario

    International Nuclear Information System (INIS)

    Anisimov, A.

    2004-01-01

    In the recently proposed 'ghost condensation' scenario a model of consistent infrared modification of gravity was suggested. We first review the basic ideas of this scenario. We discuss various phenomenological aspects of the ghost condensation, such as stability of the condensate, bounds on the UV cut-off scale of the corresponding effective field theory and other issues. (author)

  15. Molecular Diagnostic Analysis of Outbreak Scenarios

    Science.gov (United States)

    Morsink, M. C.; Dekter, H. E.; Dirks-Mulder, A.; van Leeuwen, W. B.

    2012-01-01

    In the current laboratory assignment, technical aspects of the polymerase chain reaction (PCR) are integrated in the context of six different bacterial outbreak scenarios. The "Enterobacterial Repetitive Intergenic Consensus Sequence" (ERIC) PCR was used to analyze different outbreak scenarios. First, groups of 2-4 students determined optimal…

  16. The Narrative Aspect of Scenario Building

    DEFF Research Database (Denmark)

    Rasmussen, Lauge Baungaard

    2008-01-01

    The application of narrative scenarios in engineering or socio-technical systems provides an important link between general ideas and specification of technical system requirements. The chapter explores how the narrative approach can enrich the scenario 'skeleton. In addition, criteria are sugges...

  17. Accident scenario diagnostics with neural networks

    International Nuclear Information System (INIS)

    Guo, Z.

    1992-01-01

    Nuclear power plants are very complex systems. The diagnoses of transients or accident conditions is very difficult because a large amount of information, which is often noisy, or intermittent, or even incomplete, need to be processed in real time. To demonstrate their potential application to nuclear power plants, neural networks axe used to monitor the accident scenarios simulated by the training simulator of TVA's Watts Bar Nuclear Power Plant. A self-organization network is used to compress original data to reduce the total number of training patterns. Different accident scenarios are closely related to different key parameters which distinguish one accident scenario from another. Therefore, the accident scenarios can be monitored by a set of small size neural networks, called modular networks, each one of which monitors only one assigned accident scenario, to obtain fast training and recall. Sensitivity analysis is applied to select proper input variables for modular networks

  18. Scenario research: The food industry in 2010

    DEFF Research Database (Denmark)

    Stacey, Julia; Sonne, Anne-Mette; Jensen, Birger Boutrup

    2001-01-01

    What kind of foods will the consumers choose to buy in 2010? Will they be buying organic foods, functional foods or go for the cheapest products? Nobody can predict the future. However, by using scenario techniques qualified indications on future developments can be put together. Researchers...... at MAPP and the Department of Manufacturing Engineering and Management, The Technical University of Denmark have constructed three scenarios about the Danish food industry in 2010. The aim has been to identify the demands the food industry can expect to meet in the future plus which research areas...... the public research should prioritise in order to support the development of competences within the food industry. The scenarios are isolated developments. In practise, the future is likely to be a combination of the different tendencies within the scenarios. The first scenario 'Naturalness' has focus...

  19. Scenarios for Ecosystem Services: An Overview

    Directory of Open Access Journals (Sweden)

    Stephen R. Carpenter

    2006-06-01

    Full Text Available The Millennium Ecosystem Assessment (MA scenarios address changes in ecosystem services and their implications for human well-being. Ecological changes pose special challenges for long-term thinking, because of the possibility of regime shifts that occur rapidly yet alter the availability of ecosystem services for generations. Moreover, ecological feedbacks can intensify human modification of ecosystems, creating a spiral of poverty and ecosystem degradation. Such complex dynamics were evaluated by a mixture of qualitative and quantitative analyses in the MA scenarios. Collectively, the scenarios explore problems such as the connections of poverty reduction and ecosystem services, and trade-offs among ecosystem services. Several promising approaches are considered by the scenarios, including uses of biodiversity to build resilience of ecosystem services, actively adaptive management, and green technology. Although the scenarios do not prescribe an optimal path, they illuminate the consequences of different policies toward ecosystem services.

  20. The Greenpeace 2013 scenario for energy transition

    International Nuclear Information System (INIS)

    Cormier, Cyrille; Teske, Sven

    2013-01-01

    After a synthesis of the Greenpeace scenario for energy transition, this report presents the French current energy landscape: structure of the energy system, greenhouse gas emissions and nuclear risks, main social and economic challenges, and search for a political ambition (from the Grenelle de l'Environnement to the current debate on energy). Then, after having outlined that energy transition must be decided now, the report presents the scenario hypotheses: studies used to develop the scenario, macro-economic and technical-economic hypotheses. The scenario is then presented in terms of possible trajectory, of energy demand (global evolution per sector), of energy production (electricity, heat, mobility), and of CO 2 assessment and nuclear wastes. Scenarios are compared in social and economic terms, more particularly in terms of investments in electricity and heat production systems, of electricity production costs and electricity bill, of energy independence, and of jobs in the electricity and heat sectors

  1. Energy scenarios for Colombia - Environmental Aspects

    International Nuclear Information System (INIS)

    Smith, Ricardo A; Vesga A, Daniel R; Boman, Ulf

    2000-01-01

    The planning unit of the Colombian ministry of energy -UPME -has done an energy scenario project for Colombia with a 20-year horizon (vision year 2020) in this project the scenario methodology was used in a systemic way involving a great number of local and international energy experts. As a result four energy scenarios were designed and in all of them the possible evolution of all energy was analyzed. In this article a description of the used methodology is presented with the developed scenarios. Also a discussion of the long-range future environmental considerations in the energy sector, taking into account the developed scenarios, is presented. Finally some conclusions and recommendations are presented

  2. A new scenario framework for Climate Change Research: scenario matrix architecture

    NARCIS (Netherlands)

    van Vuuren, D.P.|info:eu-repo/dai/nl/11522016X; Kriegler, E.; O'Neill, B.C.; Ebi, K.L.; Riahi, K.; Carter, T.R.; Edmonds, J.; Hallegatte, S.; Kram, T.; Mathur, R.; Winkler, H.

    2014-01-01

    This paper describes the scenario matrix architecture that underlies a framework for developing new scenarios for climate change research. The matrix architecture facilitates addressing key questions related to current climate research and policy-making: identifying the effectiveness of different

  3. Scenario forecasting changes in the water balance components of the Olenek and Iindigirka river basins due to possible climate change

    Directory of Open Access Journals (Sweden)

    Ye. M. Gusev

    2015-06-01

    Full Text Available Scenario projections of the dynamics of meteorological characteristics for the basins of the Olenek and Indigirka rivers (the Republic of Sakha in the XXI century have been obtained for four IPCC global climate change scenarios of SRES family which correspond to specified scenarios of economic, technological, political, and demographic development of human civilization. The projections have been used to calculate scenarios of possible changes in water balance components for the basins under consideration up to the year of 2063. The calculation procedure involves a physically-based model for heat and mass exchange between the land surface and the atmosphere SWAP and climate scenario generator MAGICC/SCENGEN.

  4. Scenario Development for Water Resources Planning and Management

    Science.gov (United States)

    Stewart, S.; Mahmoud, M.; Liu, Y.; Hartman, H.; Wagener, T.; Gupta, H.

    2006-12-01

    The main objective of scenario development for water resources is to inform policy-makers about the implications of various policies to inform decision-making. Although there have been a number of studies conducted in the relatively-new and recent field of scenario analysis and development, very few of those have been explicitly applied to water resource issues. More evident is the absence of an established formal approach to develop and apply scenarios. Scenario development is a process that evaluates possible future states of the world by examining several feasible scenarios. A scenario is a projection of various physical and socioeconomic conditions that describe change from the current state to a future state. In this paper, a general framework for scenario development with special emphasis on applications to water resources is considered. The process comprises several progressive and reiterative phases: scenario definition, scenario construction, scenario analysis, scenario assessment, and risk management. Several characteristics of scenarios that are important in describing scenarios are also taken into account; these include scenario types, scenario themes, scenario likelihoods and scenario categories. A hindrance to the adoption of a unified framework for scenario development is inconsistency in the terminology used by scenario developers. To address this problem, we propose a consistent terminology of basic and frequent terms. Outreach for this formal approach is partially maintained through an interactive community website that seeks to educate potential scenario developers about the scenario development process, share and exchange information and resources on scenarios to foster a multidisciplinary community of scenario developers, and establish a unified framework for scenario development with regards to terminology and guidelines. The website provides information on scenario development, current scenario-related activities, key water resources scenario

  5. Scenario Archetypes: Converging Rather than Diverging Themes

    Directory of Open Access Journals (Sweden)

    Jon P. Sadler

    2012-04-01

    Full Text Available Future scenarios provide challenging, plausible and relevant stories about how the future could unfold. Urban Futures (UF research has identified a substantial set (>450 of seemingly disparate scenarios published over the period 1997–2011 and within this research, a sub-set of >160 scenarios has been identified (and categorized based on their narratives according to the structure first proposed by the Global Scenario Group (GSG in 1997; three world types (Business as Usual, Barbarization, and Great Transitions and six scenarios, two for each world type (Policy Reform—PR, Market Forces—MF, Breakdown—B, Fortress World—FW, Eco-Communalism—EC and New Sustainability Paradigm—NSP. It is suggested that four of these scenario archetypes (MF, PR, NSP and FW are sufficiently distinct to facilitate active stakeholder engagement in futures thinking. Moreover they are accompanied by a well-established, internally consistent set of narratives that provide a deeper understanding of the key fundamental drivers (e.g., STEEP—Social, Technological, Economic, Environmental and Political that could bring about realistic world changes through a push or a pull effect. This is testament to the original concept of the GSG scenarios and their development and refinement over a 16 year period.

  6. A closed-form formulation for the build-up factor and absorbed energy for photons and electrons in the Compton energy range in Cartesian geometry

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Volnei; Vilhena, Marco Tullio, E-mail: borges@ufrgs.b, E-mail: vilhena@pq.cnpq.b [Universidade Federal do Rio Grande do Sul (PROMEC/UFRGS), Porto Alegre, RS (Brazil). Programa de Pos-Graduacao em Engenharia Mecanica; Fernandes, Julio Cesar Lombaldo, E-mail: julio.lombaldo@ufrgs.b [Universidade Federal do Rio Grande do Sul (DMPA/UFRGS), Porto Alegre, RS (Brazil). Dept. de Matematica Pura e Aplicada. Programa de Pos Graduacao em Matematica Aplicada

    2011-07-01

    In this work, we report on a closed-form formulation for the build-up factor and absorbed energy, in one and two dimensional Cartesian geometry for photons and electrons, in the Compton energy range. For the one-dimensional case we use the LTS{sub N} method, assuming the Klein-Nishina scattering kernel for the determination of the angular radiation intensity for photons. We apply the two-dimensional LTS{sub N} nodal solution for the averaged angular radiation evaluation for the two-dimensional case, using the Klein-Nishina kernel for photons and the Compton kernel for electrons. From the angular radiation intensity we construct a closed-form solution for the build-up factor and evaluate the absorbed energy. We present numerical simulations and comparisons against results from the literature. (author)

  7. A closed-form formulation for the build-up factor and absorbed energy for photons and electrons in the Compton energy range in Cartesian geometry

    International Nuclear Information System (INIS)

    Borges, Volnei; Vilhena, Marco Tullio; Fernandes, Julio Cesar Lombaldo

    2011-01-01

    In this work, we report on a closed-form formulation for the build-up factor and absorbed energy, in one and two dimensional Cartesian geometry for photons and electrons, in the Compton energy range. For the one-dimensional case we use the LTS N method, assuming the Klein-Nishina scattering kernel for the determination of the angular radiation intensity for photons. We apply the two-dimensional LTS N nodal solution for the averaged angular radiation evaluation for the two-dimensional case, using the Klein-Nishina kernel for photons and the Compton kernel for electrons. From the angular radiation intensity we construct a closed-form solution for the build-up factor and evaluate the absorbed energy. We present numerical simulations and comparisons against results from the literature. (author)

  8. Alfven Spectroscopy for Advanced Scenarios on JET

    Energy Technology Data Exchange (ETDEWEB)

    Sharapov, S. E.

    2007-07-01

    Advanced tokamak scenarios on JET exhibit outstanding quality fusion-grade plasmas, with internal transport barriers (ITBs) capable of supporting gradients {nabla} T{sub i}{approx_equal} 150 keV/m (with T{sub i}(0){approx_equal} 40 keV), and with q(r)-profiles ranging from monotonic to deep shear reversal, including the limiting case of toroidal current holes. It was found experimentally, that in reversed shear JET discharges the ITB start from so-called ITB triggering events, which are seen as increases in electron temperature within, e.g. r/a {<=} 0.4 by {delta} T{sub e}/T{sub e}{approx} 10-30%. If main heating power is applied at this time, an ITB is formed easily. Without an extra-heating power the improved confinement effect is lost in about 100 msec. Here, we investigate the magnetic field topology at the time of the ITB triggering events in JET plasmas. Alfven spectroscopy based on discrete spectrum of Alfven eigenmodes (AEs) excited by ICRH-accelerated and/or NBI-produced energetic ions is used for determining the evolution of the q(r)- profiles. Recently developed interferometry diagnostics of AEs significantly extended time resolution and sensitivity of Alfven spectroscopy on JET and made it possible to perform the ITB triggering event studies with a high accuracy. The ITB triggering events are found to occur when q{sub min} (t) passes values q{sub min} integer (majority of the cases), q{sub min}= half-integer, and when q(r=0)--infinity (current hole is triggered). This experimental data is compared to the density of rational surfaces transport theory. (Author)

  9. Alfven Spectroscopy for Advanced Scenarios on JET

    International Nuclear Information System (INIS)

    Sharapov, S. E.

    2007-01-01

    Advanced tokamak scenarios on JET exhibit outstanding quality fusion-grade plasmas, with internal transport barriers (ITBs) capable of supporting gradients ∇ T i ≅ 150 keV/m (with T i (0)≅ 40 keV), and with ) q(r) -profiles ranging from monotonic to deep shear reversal, including the limiting case of toroidal current holes. It was found experimentally, that in reversed shear JET discharges the ITB start from so-called ITB triggering events, which are seen as increases in electron temperature within, e.g. r/a ≤ 0.4 by Δ T e /T e ∼ 10-30%. If main heating power is applied at this time, an ITB is formed easily. Without an extra-heating power the improved confinement effect is lost in about 100 msec. Here, we investigate the magnetic field topology at the time of the ITB triggering events in JET plasmas. Alfven spectroscopy based on discrete spectrum of Alfven eigenmodes (AEs) excited by ICRH-accelerated and/or NBI-produced energetic ions is used for determining the evolution of the q(r)- profiles. Recently developed interferometry diagnostics of AEs significantly extended time resolution and sensitivity of Alfven spectroscopy on JET and made it possible to perform the ITB triggering event studies with a high accuracy. The ITB triggering events are found to occur when q m in (t) passes values q m ininteger (majority of the cases), q m in= half-integer, and when q(r=0)--∞ (current hole is triggered). This experimental data is compared to the idensity of rational surfaces transport theory. (Author)

  10. Quantitative scenario analysis of low and intermediate level radioactive repository

    International Nuclear Information System (INIS)

    Lee, Keon Jae; Lee, Sang Yoon; Park, Keon Baek; Song, Min Cheon; Lee, Ho Jin

    1998-03-01

    Derivation of hypothetical radioactive waste disposal facility os conducted through sub-component characteristic analysis and conceptual modeling. It is studied that quantitative analysis of constructed scenario in terms of annual effective dose equivalent. This study is sequentially conducted according to performance assessment of radioactive waste disposal facility such as : ground water flow analysis, source term analysis, ground water transport, surface water transport, dose and pathways. The routine program module such as VAM2D-PAGAN-GENII is used for quantitative scenario analysis. Detailed data used in this module are come from experimental data of Korean territory and default data given within this module. Is case of blank data for code execution, it is estimated through reasonable engineering sense

  11. Baseline scenarios of global environmental change

    International Nuclear Information System (INIS)

    Alcamo, J.; Kreileman, G.J.J.; Bollen, J.C.; Born, G.J. van den; Krol, M.S.; Toet, A.M.C.; Vries, H.J.M. de; Gerlagh, R.

    1996-01-01

    This paper presents three baseline scenarios of no policy action computed by the IMAGE2 model. These scenarios cover a wide range of coupled global change indicators, including: energy demand and consumption; food demand, consumption, and production; changes in land cover including changes in extent of agricultural land and forest; emissions of greenhouse gases and ozone precursors; and climate change and its impacts on sea level rise, crop productivity and natural vegetation. Scenario information is available for the entire world with regional and grid scale detail, and covers from 1970 to 2100. (author)

  12. Catheter for Cleaning Surgical Optics During Surgical Procedures: A Possible Solution for Residue Buildup and Fogging in Video Surgery.

    Science.gov (United States)

    de Abreu, Igor Renato Louro Bruno; Abrão, Fernando Conrado; Silva, Alessandra Rodrigues; Corrêa, Larissa Teresa Cirera; Younes, Riad Nain

    2015-05-01

    Currently, there is a tendency to perform surgical procedures via laparoscopic or thoracoscopic access. However, even with the impressive technological advancement in surgical materials, such as improvement in quality of monitors, light sources, and optical fibers, surgeons have to face simple problems that can greatly hinder surgery by video. One is the formation of "fog" or residue buildup on the lens, causing decreased visibility. Intracavitary techniques for cleaning surgical optics and preventing fog formation have been described; however, some of these techniques employ the use of expensive and complex devices designed solely for this purpose. Moreover, these techniques allow the cleaning of surgical optics when they becomes dirty, which does not prevent the accumulation of residue in the optics. To solve this problem we have designed a device that allows cleaning the optics with no surgical stops and prevents the fogging and residue accumulation. The objective of this study is to evaluate through experimental testing the effectiveness of a simple device that prevents the accumulation of residue and fogging of optics used in surgical procedures performed through thoracoscopic or laparoscopic access. Ex-vivo experiments were performed simulating the conditions of residue presence in surgical optics during a video surgery. The experiment consists in immersing the optics and catheter set connected to the IV line with crystalloid solution in three types of materials: blood, blood plus fat solution, and 200 mL of distilled water and 1 vial of methylene blue. The optics coupled to the device were immersed in 200 mL of each type of residue, repeating each immersion 10 times for each distinct residue for both thirty and zero degrees optics, totaling 420 experiments. A success rate of 98.1% was observed after the experiments, in these cases the device was able to clean and prevent the residue accumulation in the optics.

  13. THE XMM CLUSTER SURVEY: THE BUILD-UP OF STELLAR MASS IN BRIGHTEST CLUSTER GALAXIES AT HIGH REDSHIFT

    International Nuclear Information System (INIS)

    Stott, J. P.; Collins, C. A.; Hilton, M.; Capozzi, D.; Sahlen, M.; Lloyd-Davies, E.; Hosmer, M.; Liddle, A. R.; Mehrtens, N.; Romer, A. K.; Miller, C. J.; Stanford, S. A.; Viana, P. T. P.; Davidson, M.; Hoyle, B.; Kay, S. T.; Nichol, R. C.

    2010-01-01

    We present deep J- and K s -band photometry of 20 high redshift galaxy clusters between z = 0.8 and1.5, 19 of which are observed with the MOIRCS instrument on the Subaru telescope. By using near-infrared light as a proxy for stellar mass we find the surprising result that the average stellar mass of Brightest Cluster Galaxies (BCGs) has remained constant at ∼9 x 10 11 M sun since z ∼ 1.5. We investigate the effect on this result of differing star formation histories generated by three well-known and independent stellar population codes and find it to be robust for reasonable, physically motivated choices of age and metallicity. By performing Monte Carlo simulations we find that the result is unaffected by any correlation between BCG mass and cluster mass in either the observed or model clusters. The large stellar masses imply that the assemblage of these galaxies took place at the same time as the initial burst of star formation. This result leads us to conclude that dry merging has had little effect on the average stellar mass of BCGs over the last 9-10 Gyr in stark contrast to the predictions of semi-analytic models, based on the hierarchical merging of dark matter halos, which predict a more protracted mass build-up over a Hubble time. However, we discuss that there is potential for reconciliation between observation and theory if there is a significant growth of material in the intracluster light over the same period.

  14. A polynomial–based function approach to point isotropic gamma-ray buildup factor data in double layered spherical shield of water and lead

    Directory of Open Access Journals (Sweden)

    M. H. Alamatsaz

    2014-03-01

    Full Text Available As the input of MCNP code (Monte Carlo N - Particle code system, a monoenergetic and isotropic point source with the energy rangeg from 0.3 to 10 MeV was placed at the center of a spherical material surrounded by another one. The first shielding material was water and the second one was lead. The total thickness of the shield varied between 2 to 10 mfp. Then, using the output of MCNCP, exposure build up factor was calculated. The MCNP computed data were analyzed by plotting the buildup factor as a function of each independent variable (energy, first material thickness and second material thickness and observing the trends. Based on the trends, we examined many different expressions with different number of constants. By MINUIT the FORTRAN program, the constants were calculated, which gave the best agreement between the MCNP-computed exposure buildup factors and those obtained by the formula. At last, we developed a polynomial formula with 11 constants that reproduced exposure buildup factor with a relative error below 2% (in comparison with the MCNP result.

  15. Measurement of air kerma rates for 6- to 7-MeV high-energy gamma-ray field by ionisation chamber and build-up plate.

    Science.gov (United States)

    Kowatari, Munehiko; Tanimura, Yoshihiko; Tsutsumi, Masahiro

    2014-12-01

    The 6- to 7-MeV high-energy gamma-ray calibration field by the (19)F(p, αγ)(16)O reaction is to be served at the Japan Atomic Energy Agency. For the determination of air kerma rates using an ionisation chamber in the 6- to 7-MeV high-energy gamma-ray field, the establishment of the charged particle equilibrium must be achieved during measurement. In addition to measurement of air kerma rates by the ionisation chamber with a thick build-up cap, measurement using the ionisation chamber and a build-up plate (BUP) was attempted, in order to directly determine air kerma rates under the condition of regular calibration for ordinary survey meters and personal dosemeters. Before measurements, Monte Carlo calculations were made to find the optimum arrangement of BUP in front of the ionisation chamber so that the charged particle equilibrium could be well established. Measured results imply that air kerma rates for the 6- to 7-MeV high-energy gamma-ray field could be directly determined under the appropriate condition using an ionisation chamber coupled with build-up materials. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Coordinated Development and Deployment of Scenarios for Sustained Assessment

    Science.gov (United States)

    Lipschultz, F.; Weaver, C. P.; Leidner, A. K.; Delgado, A.; Grambsch, A.

    2017-12-01

    There has been a clear need for a more coordinated Federal government approach for authoritative, climate-relevant scenarios to support growing demands by decision-makers, to meet stakeholder needs for consistent approaches and guidance, and to better address the needs of the impacts, adaptation and vulnerability community. To begin to satisfy these decision-support needs, in early 2015 the U.S. Global Change Research Program (USGCRP) began coordinated production of scenario information for use across a suite of USGCRP activities. These have been implemented in the 4th National Climate Assessment (NCA4), the Climate Science Special Report and the Climate Resilience Toolkit (CRT), all of which are intended to help better organize, summarize, and communicate science to decision-makers as they think about our future. First, USGCRP introduced and implemented an explicit risk-framing approach across the entire scenario enterprise to encourage exploration of tail risks. A suite of scenario products was developed framed around three simplified storylines: `Lower', `Higher', and `Upper Bound' departures from current baselines. Second, USGCRP developed future climate information for the U.S. using Representative Concentration Pathway (RCP) 8.5 and RCP 4.5, including a weighted mean of Global Climate Models and adoption of an improved statistical downscaling approach across USGCRP products. Additional variables were derived from the downscaled parameters for use across USGCRP reports and in the CRT's Climate Explorer tool. Third, and given the need to address other tightly-coupled global changes in a more integrated way, a set of population, housing density, and impervious surface projections were developed based on global scenarios. In addition, USGCRP and the National Ocean Council developed scenarios of future sea-level rise and coastal-flood hazard for the U.S. and integrated them into existing Federal capabilities to support preparedness planning. To better convey these

  17. Experts dismiss doomsday scenarios for RHIC

    CERN Multimedia

    Levi, B G

    2000-01-01

    A panel of particle physicists examining the possibility that operation of RHIC could generate blackholes or 'strangelets' which would consume ordinary matter, have declared that such scenarios are 'firmly excluded' (1 p).

  18. Group 1: Scenario design and development issues

    Science.gov (United States)

    Sherwin, P.

    1981-01-01

    All LOFT scenarios and flight segments should be designed on the basis of a detailed statement of specific objectives. These objectives must state what kind of situation is to be addressed and why. The origin, routing, and destination of a particular scenario should be dictated by the specific objectives for that scenario or leg. Other factors to be considered are the desired weather, climate, etc. Simulator visual system, as well as other capabilities and limitations must be considered at a very early stage of scenario design. The simulator navigation area must be apropriate and must coincide with current Jeppeson charts. Much of the realism of LOFT is destroyed if the crew is unable to use current manuals and other materials.

  19. Model Performance Evaluation and Scenario Analysis (MPESA)

    Science.gov (United States)

    Model Performance Evaluation and Scenario Analysis (MPESA) assesses the performance with which models predict time series data. The tool was developed Hydrological Simulation Program-Fortran (HSPF) and the Stormwater Management Model (SWMM)

  20. Environmental evaluation of plastic waste management scenarios

    DEFF Research Database (Denmark)

    Rigamonti, L.; Grosso, M.; Møller, Jacob

    2014-01-01

    The management of the plastic fraction is one of the most debated issues in the discussion on integrated municipal solid waste systems. Both material and energy recovery can be performed on such a waste stream, and different separate collection schemes can be implemented. The aim of the paper....... The study confirmed the difficulty to clearly identify an optimal strategy for plastic waste management. In fact none of the examined scenarios emerged univocally as the best option for all impact categories. When moving from the P0 treatment strategy to the other scenarios, substantial improvements can...... is to contribute to the debate, based on the analysis of different plastic waste recovery routes. Five scenarios were defined and modelled with a life cycle assessment approach using the EASEWASTE model. In the baseline scenario (P0) the plastic is treated as residual waste and routed partly to incineration...

  1. Scenarios for the food industry in 2010

    DEFF Research Database (Denmark)

    Harmsen, Hanne; Jensen, Birger Boutrup; Sonne, Anne-Mette

    2001-01-01

    visions of the future of the food industry and to assess their implications for competence requirements. Given the uncertain nature of the environment, food companies cannot rely on today's competencies being sufficient to fulfil the demands of tomorrow's markets. However, predicting the determinants......Predicting the future is impossible; corporate decision-makers have, however, to decide which competencies to develop precisely on this basis. This article presents the results of a research project on scenario analyses in the Danish food industry. The aim of the study is to look at alternative...... of success in the food industry 10 years hence is a daunting task. Scenario techniques can be very useful in this respect (von Reibnitz, 1988). The contribution of the article is the methodological approach to scenario building, which combines academic and industry input and translates the scenarios...

  2. Using Service Scenarios to Model Business Services

    DEFF Research Database (Denmark)

    Bækgaard, Lars

    The purpose of the paper is to present and evaluate the notion of service scenarios. A service is work done by a service executor in interaction with a service consumer. A service scenario is a model of a service system and the roles that are played by the actors participating and interacting...... during the execution of a service. The model represents the roles and the interactions between the participants. Service scenarios can be used to model specific services and roles played by human beings and IT systems in the execution of services. The use of service scenarios is demonstrated by means...... of a case study in a public library. The case study indicates that service systems should be understood as socio-technical systems in which service executors and service consumers co-create value in mutual interaction with each other and with a set of shared resources....

  3. ANCRE scenarios for energy transition. Report 2013

    International Nuclear Information System (INIS)

    Alazard-Toux, Nathalie; Des Courtils, Nicolas; Hache, Emmanuel; Liegeard, Alban; Lorne, Daphne; Duplan, Jean-Luc; Kalaydjian, Francois; Heintze, Eric; Tilagone, Richard; Henriot, Stephane; Forti, Laurent; Barthelemy, Pascal; Merlen, Elisabeth; Criqui, Patrick; Mathy, Sandrine; Menanteau, Philippe; Devezeaux De Lavergne, Jean-Guy; Avril, Sophie; Cavata, Christian; Le Duigou, Alain; Le Net, Elisabeth; Marcucci-Demeure, Jeanne; Safa, Henri; Topper, Benjamin; Touboul, Francoise; Carre, Franck; Joly, Jean-Pierre; Charbit, Francoise; Mermilliod, Nicole; Mermilliod, Nicole; Le Net, Elisabeth; Teissier, Olivier; Charrue, Herve; Colonna, Paul; Legrand, Jack; Vidal, Olivier; Goffe, Bruno; Mueller, Alex; Flamant, Gilles; Allard, Francis; Most, Jean-Michel; Matarasso, Pierre; Brault, Pascal; Lemoine, Lionel; Achard, Jean-Luc; Uster, Guillaume; Delsey, Jean; Lucchese, Paul; Tadrist, Lounes; Hadjsaid, Nouredine

    2014-01-01

    This report first gives an overview of the energy system by presenting the determining factors of energy demand and of CO 2 emissions per sector (housing and office building, transport, industry, agriculture, forestry and biomass), by analysing energy systems and CO 2 emissions (energy sources, energy vectors, networks and storage, energy and CO 2 assessment for France), and by describing the guidelines of the scenarios proposed by ANCRE. The three main scenarios are characterized by a stronger sobriety, an electricity-based de-carbonation (with a variant based on nuclear and renewable energies), and diversified vectors. They are notably compared to a trend-based reference scenario. Results are discussed in terms of energy consumption (primary and final energy, consumption by the different sectors), of energy production and CO 2 emissions. Scenarios are assessed in terms of economic, environmental and societal, political and strategic criteria. Some consequences for research topics and funding are identified

  4. Scenario research: The food industry in 2010

    OpenAIRE

    Stacey, Julia; Sonne, Anne-Mette; Jensen, Birger Boutrup

    2001-01-01

    What kind of foods will the consumers choose to buy in 2010? Will they be buying organic foods, functional foods or go for the cheapest products? Nobody can predict the future. However, by using scenario techniques qualified indications on future developments can be put together. Researchers at MAPP and the Department of Manufacturing Engineering and Management, The Technical University of Denmark have constructed three scenarios about the Danish food industry in 2010. The aim has been to ide...

  5. FAST Plasma Scenarios and Equilibrium Configurations

    International Nuclear Information System (INIS)

    Calabro, G.; Crisanti, F.; Ramogida, G.; Cardinali, A.; Cucchiaro, A.; Maddaluno, G.; Pizzuto, A.; Pericoli Ridolfini, V.; Tuccillo, A.A.; Zonca, F.; Albanese, R.; Granucci, G.; Nowak, S.

    2008-01-01

    In this paper we present the Fusion Advanced Studies Torus (FAST) plasma scenarios and equilibrium configurations, designed to reproduce the ITER ones (with scaled plasma current) and suitable to fulfil plasma conditions for integrated studies of burning plasma physics, Plasma Wall interaction, ITER relevant operation problems and Steady State scenarios. The attention is focused on FAST flexibility in terms of both performance and physics that can be investigated: operations are foreseen at a wide range of parameters from high performance H-Mode (toroidal field, B T , up to 8.5 T; plasma current, I P , up to 8 MA) to advanced tokamak (AT) operation (I P =3 MA) as well as full non inductive current scenario (I P =2 MA). The coupled heating power is provided with 30MW delivered by an Ion Cyclotron Resonance Heating (ICRH) system (30-90MHz), 6 MW by a Lower Hybrid (LH) system (3.7 or 5 GHz) for the long pulse AT scenario, 4 MW by an Electron Cyclotron Resonant Heating (ECRH) system (170 GHz-B T =6T) for MHD and electron heating localized control and, eventually, with 10 MW by a Negative Ion Beam (NNBI), which the ports are designed to accommodate. In the reference H-mode scenario FAST preserves (with respect to ITER) fast ions induced as well as turbulence fluctuation spectra, thus, addressing the cross-scale couplings issue of micro- to meso-scale physics. The noninductive scenario at I P =2MA is obtained with 60-70 % of bootstrap and the remaining by LHCD. Predictive simulations of the H-mode scenarios described above have been performed by means of JETTO code, using a semi-empirical mixed Bohm/gyro-Bohm transport model. Plasma position and Shape Control studies are also presented for the reference scenario

  6. Intrusion scenarios in fusion waste disposal sites

    International Nuclear Information System (INIS)

    Zucchetti, M.; Zucchetti, M.; Rocco, P.

    1998-01-01

    Results of analyses on human intrusions into repositories of fusion radioactive waste are presented. The main topics are: duration of the institutional control, occurrence of intrusion, intrusion scenarios, acceptable risk limits and probabilistic data. Application to fusion waste repositories is implemented with a computational model: wells drilling is considered as the possible scenario. Doses and risks to intruder for different SEAFP-2 cases turn out to be very small. No intervention to reduce the hazard is necessary. (authors)

  7. Intrusion scenarios in fusion waste disposal sites

    Energy Technology Data Exchange (ETDEWEB)

    Zucchetti, M. [European Commission, JRC, Institute for Advanced Material, Ispra, Vatican City State, Holy See (Italy); Zucchetti, M.; Rocco, P. [Energetics Dept., Polytechnic of Turin (Italy)

    1998-07-01

    Results of analyses on human intrusions into repositories of fusion radioactive waste are presented. The main topics are: duration of the institutional control, occurrence of intrusion, intrusion scenarios, acceptable risk limits and probabilistic data. Application to fusion waste repositories is implemented with a computational model: wells drilling is considered as the possible scenario. Doses and risks to intruder for different SEAFP-2 cases turn out to be very small. No intervention to reduce the hazard is necessary. (authors)

  8. Quantifying scenarios to check statistical procedures

    International Nuclear Information System (INIS)

    Beetle, T.M.

    1976-01-01

    Ways of diverting nuclear material are presented in a form that reflects the effects of the diversions on a select set of statistical accounting procedures. Twelve statistics are examined for changes in mean values under sixty diversion scenarios. Several questions about the statistics are answered using a table of quantification results. Findings include a smallest, proper subset of the set of statistics which has one or more changed mean values under each of the diversion scenarios

  9. The negaWatt 2011 scenario

    International Nuclear Information System (INIS)

    2016-03-01

    This article presents the approach adopted for the negaWatt scenario and its obtained results. It is based on sobriety (energy savings), on energy efficiency, and on the use of renewable energies. After having outlined the different reasons for an energy transition (increasing energy consumption, critics and risks related to nuclear energy, and high potential of renewable energies), the scenario is presented with its main principles. The scenario identifies possibilities ranging from half to two thirds of energy saving in the different energy consuming sectors. The building sector is presented as a major issue. The transport is described as a sector to be addressed on the long term. The necessary change of the industry sector is highlighted. The agriculture sector is presented as being at the heart of transition. Energy usages are to become sober, efficient and renewable. The scenario is based on a high rate development of renewable energies, while fossil energies are to become marginal, nuclear is to be progressively and reasonably given up, and networks are to become compatible to ensure the scenario success. Thus, the scenario demonstrates the feasibility of a 100 pc sustainable assessment for primary energy, complies with stakes and objectives by 2050. The cost of energy transition is briefly discussed

  10. Future nuclear energy scenarios for Europe

    International Nuclear Information System (INIS)

    Roelofs, F.; Van Heek, A.

    2010-01-01

    Nuclear energy is back on the agenda worldwide. In order to prepare for the next decades and to set priorities in nuclear R and D and investment, market share scenarios are evaluated. This allows to identify the triggers which influence the market penetration of future nuclear reactor technologies. To this purpose, scenarios for a future nuclear reactor park in Europe have been analysed applying an integrated dynamic process modelling technique. Various market share scenarios for nuclear energy are derived including sub-variants with regard to the intra-nuclear options taken, e.g. introduction date of Gen-III (i.e. EPR) and Gen-IV (i.e. SCWR, HTR, FR) reactors, level of reprocessing, and so forth. The assessment was undertaken using the DANESS code which allows to provide a complete picture of mass-flow and economics of the various nuclear energy system scenarios. The analyses show that the future European nuclear park will exist of combinations of Gen-III and Gen-IV reactors. This mix will always consist of a set of reactor types each having its specific strengths. Furthermore, the analyses highlight the triggers influencing the choice between different nuclear energy deployment scenarios. In addition, a dynamic assessment is made with regard to manpower requirements for the construction of a future nuclear fleet in the different scenarios. (authors)

  11. Constellation Architecture Team-Lunar Scenario 12.0 Habitation Overview

    Science.gov (United States)

    Kennedy, Kriss J.; Toups, Larry D.; Rudisill, Marianne

    2010-01-01

    This paper will describe an overview of the Constellation Architecture Team Lunar Scenario 12.0 (LS-12) surface habitation approach and concept performed during the study definition. The Lunar Scenario 12 architecture study focused on two primary habitation approaches: a horizontally-oriented habitation module (LS-12.0) and a vertically-oriented habitation module (LS-12.1). This paper will provide an overview of the 12.0 lunar surface campaign, the associated outpost architecture, habitation functionality, concept description, system integration strategy, mass and power resource estimates. The Scenario 12 architecture resulted from combining three previous scenario attributes from Scenario 4 "Optimized Exploration", Scenario 5 "Fission Surface Power System" and Scenario 8 "Initial Extensive Mobility" into Scenario 12 along with an added emphasis on defining the excursion ConOps while the crew is away from the outpost location. This paper will describe an overview of the CxAT-Lunar Scenario 12.0 habitation concepts and their functionality. The Crew Operations area includes basic crew accommodations such as sleeping, eating, hygiene and stowage. The EVA Operations area includes additional EVA capability beyond the suitlock function such as suit maintenance, spares stowage, and suit stowage. The Logistics Operations area includes the enhanced accommodations for 180 days such as enhanced life support systems hardware, consumable stowage, spares stowage, interconnection to the other habitation elements, a common interface mechanism for future growth, and mating to a pressurized rover or Pressurized Logistics Module (PLM). The Mission & Science Operations area includes enhanced outpost autonomy such as an IVA glove box, life support, medical operations, and exercise equipment.

  12. Mississippian carbonate buildups and development of cool-waterlike carbonate platforms in the Illinois Basin, Midcontinent U.S.A.

    Science.gov (United States)

    Lasemi, Z.; Norby, R.D.; Utgaard, J.E.; Ferry, W.R.; Cuffey, R.J.; Dever, G.R.

    2005-01-01

    Numerous biohermal buildups occur in Mississippian (Lower Carboniferous) strata in the Illinois Basin and adjacent regions. They developed as mud mounds, biodetrital calcisiltite mounds, and bryozoan frame thickets (fenestrate-frame coquina or rudstone) during the Kinderhookian and early Meramecian (Tournaisian and early Visean), and as microbial mud mounds, microbial- serpulidbryozoanboundstones, and solenoporoid (red algal) boundstones during the Chesterian (late Visean and Serpukhovian). True Waulsortian mounds did not develop in the Illinois Basin, but echinoderm (primarily crinoids)-bryozoan carbonate banks and bryozoan frame thickets generally occupied the same niche during the Kinderhookian-early Meramecian. Nutrient availability and the resulting increase in the productivity of echinoderms and bryozoans were apparently detrimental to Waulsortian mound development. Deposition of crinoidal-bryozoan carbonates during the Kinderhookian-Osagean initially occurred on a ramp setting that later evolved into a platform with a relatively steep margin through sediment aggradation and progradation. By mid-Osagean-early Meramecian, two such platforms, namely the Burlington Shelf and the Ullin Platform, developed adjacent to a deep, initially starved basin. Sedimentologic and petrographic characteristics of the Kinderhookian-earliest Meramecian carbonates resemble the modern cool-water Heterozoan Association. This is in contrast with post-earliest Meramecian carbonates, which are typically oolitic and peloidal with common peri tidal facies. The post-earliest Meramecian carbonates, therefore, resemble those of the warm-water Photozoan Association. The prevalence of Heterozoan carbonates in the Illinois Basin correlates with a rapid increase in the rate of subsidence and a major second-order eustatic sea-level rise that resulted in deep-water starved basins at this time. In the starved Illinois Basin, deposition was initially limited to a thin phosphatic shale that was

  13. Assessment of environmental impacts following alternative agricultural policy scenarios.

    Science.gov (United States)

    Bárlund, I; Lehtonen, H; Tattari, S

    2005-01-01

    Abstract Finnish agriculture is likely to undergo major changes in the near and intermediate future. The ifuture policy context can be examined at a general level by strategic scenario building. Computer-based modelling in combination with agricultural policy scenarios can in turn create a basis for the assessments of changes in environmental quality following possible changes in Finnish agriculture. The analysis of economic consequences is based on the DREMFIA model, which is applied to study effects of various agricultural policies on land use, animal production, and farmers' income. The model is suitable for an impact analysis covering an extended time span--here up to the year 2015. The changes in land use, obtained with the DREMFIA model assuming rational economic behaviour, form the basis when evaluating environmental impacts of different agricultural policies. The environmental impact assessment is performed using the field scale nutrient transport model ICECREAM. The modelled variables are nitrogen and phosphorus losses in surface runoff and percolation. In this paper the modelling strategy will be presented and highlighted using two case study catchments with varying environmental conditions and land use as an example. In addition, the paper identifies issues arising when connecting policy scenarios with impact modelling.

  14. Carbon-constrained scenarios. Final report

    International Nuclear Information System (INIS)

    2009-05-01

    This report provides the results of the study entitled 'Carbon-Constrained Scenarios' that was funded by FONDDRI from 2004 to 2008. The study was achieved in four steps: (i) Investigating the stakes of a strong carbon constraint for the industries participating in the study, not only looking at the internal decarbonization potential of each industry but also exploring the potential shifts of the demand for industrial products. (ii) Developing an hybrid modelling platform based on a tight dialog between the sectoral energy model POLES and the macro-economic model IMACLIM-R, in order to achieve a consistent assessment of the consequences of an economy-wide carbon constraint on energy-intensive industrial sectors, while taking into account technical constraints, barriers to the deployment of new technologies and general economic equilibrium effects. (iii) Producing several scenarios up to 2050 with different sets of hypotheses concerning the driving factors for emissions - in particular the development styles. (iv) Establishing an iterative dialog between researchers and industry representatives on the results of the scenarios so as to improve them, but also to facilitate the understanding and the appropriate use of these results by the industrial partners. This report provides the results of the different scenarios computed in the course of the project. It is a partial synthesis of the work that has been accomplished and of the numerous exchanges that this study has induced between modellers and stakeholders. The first part was written in April 2007 and describes the first reference scenario and the first mitigation scenario designed to achieve stabilization at 450 ppm CO 2 at the end of the 21. century. This scenario has been called 'mimetic' because it has been build on the assumption that the ambitious climate policy would coexist with a progressive convergence of development paths toward the current paradigm of industrialized countries: urban sprawl, general

  15. EDITORIAL: Where next with global environmental scenarios? Where next with global environmental scenarios?

    Science.gov (United States)

    O'Neill, Brian; Pulver, Simone; Van Deveer, Stacy; Garb, Yaakov

    2008-12-01

    Scenarios have become a standard tool in the portfolio of techniques that scientists and policy-makers use to envision and plan for the future. Defined as plausible, challenging and relevant stories about how the future might unfold that integrate quantitative models with qualitative assessments of social and political trends, scenarios are a central component in assessment processes for a range of global issues, including climate change, biodiversity, agriculture, and energy. Yet, despite their prevalence, systematic analysis of scenarios is in its beginning stages. Fundamental questions remain about both the epistemology and scientific credibility of scenarios and their roles in policymaking and social change. Answers to these questions have the potential to determine the future of scenario analyses. Is scenario analysis moving in the direction of earth system governance informed by global scenarios generated through increasingly complex and comprehensive models integrating socio-economic and earth systems? Or will global environmental scenario analyses lose favour compared to more focused, policy-driven, regionally specific modelling? These questions come at an important time for the climate change issue, given that the scenario community, catalyzed by the Intergovernmental Panel on Climate Change (IPCC), is currently preparing to embark on a new round of scenario development processes aimed at coordinating research and assessment, and informing policy, over the next five to ten years. These and related questions about where next to go with global environmental scenarios animated a workshop held at Brown University (Note1) that brought together leading practitioners and scholars of global environmental change scenarios from research, policy-making, advocacy, and business settings. The workshop aimed to provide an overview of current practices/best practices in scenario production and scenario use across a range of global environmental change arenas. Participants

  16. Water use implications of biofuel scenarios

    Science.gov (United States)

    Teter, J.; Mishra, G. S.; Yeh, S.

    2012-12-01

    Existing studies rely upon attributional lifecycle analysis (LCA) approaches to estimate water intensity of biofuels in liters of irrigated/evapotranspiration water consumed for biofuel production. Such approaches can be misleading. From a policy perspective, a better approach is to compare differential water impacts among scenarios on a landscape scale. We address the shortcomings of existing studies by using consequential LCA, and incorporate direct and indirect land use (changes) of biofuel scenarios, marginal vs. average biofuel water use estimates, future climate, and geographic heterogeneity. We use the outputs of a partial equilibrium economic model, climate and soil data, and a process-based crop-soil-climate-water model to estimate differences in green water (GW - directly from precipitation to soil) and blue water (BW - supplied by irrigation) use among three scenarios: (1) business-as-usual (BAU), (2) Renewable Fuels Standard (RFS) mandates, and (3) a national Low Carbon Fuel Standard (LCFS) plus the RFS scenario. We use spatial statistical methods to interpolate key climatic variables using daily climate observations for the contiguous USA. Finally, we use FAO's crop model AquaCrop to estimate the domestic GW and BW impacts of biofuel policies from 2007-2035. We assess the differences among scenarios along the following metrics: (1) crop area expansion at the county level, including prime and marginal lands, (2) crop-specific and overall annual/seasonal water balances including (a) water inflows (irrigation & precipitation), (b) crop-atmosphere interactions: (evaporation & transpiration) and (d) soil-water flows (runoff & soil infiltration), in mm 3 /acre over the relevant time period. The functional unit of analysis is the BW and GW requirements of biofuels (mm3 per Btu biofuel) at the county level. Differential water use impacts among scenarios are a primarily a function of (1) land use conversion, in particular that of formerly uncropped land classes

  17. Arctic shipping emissions inventories and future scenarios

    Directory of Open Access Journals (Sweden)

    J. J. Corbett

    2010-10-01

    Full Text Available This paper presents 5 km×5 km Arctic emissions inventories of important greenhouse gases, black carbon and other pollutants under existing and future (2050 scenarios that account for growth of shipping in the region, potential diversion traffic through emerging routes, and possible emissions control measures. These high-resolution, geospatial emissions inventories for shipping can be used to evaluate Arctic climate sensitivity to black carbon (a short-lived climate forcing pollutant especially effective in accelerating the melting of ice and snow, aerosols, and gaseous emissions including carbon dioxide. We quantify ship emissions scenarios which are expected to increase as declining sea ice coverage due to climate change allows for increased shipping activity in the Arctic. A first-order calculation of global warming potential due to 2030 emissions in the high-growth scenario suggests that short-lived forcing of ~4.5 gigagrams of black carbon from Arctic shipping may increase global warming potential due to Arctic ships' CO2 emissions (~42 000 gigagrams by some 17% to 78%. The paper also presents maximum feasible reduction scenarios for black carbon in particular. These emissions reduction scenarios will enable scientists and policymakers to evaluate the efficacy and benefits of technological controls for black carbon, and other pollutants from ships.

  18. Analysis of JT-60SA operational scenarios

    Science.gov (United States)

    Garzotti, L.; Barbato, E.; Garcia, J.; Hayashi, N.; Voitsekhovitch, I.; Giruzzi, G.; Maget, P.; Romanelli, M.; Saarelma, S.; Stankiewitz, R.; Yoshida, M.; Zagórski, R.

    2018-02-01

    Reference scenarios for the JT-60SA tokamak have been simulated with one-dimensional transport codes to assess the stationary state of the flat-top phase and provide a profile database for further physics studies (e.g. MHD stability, gyrokinetic analysis) and diagnostics design. The types of scenario considered vary from pulsed standard H-mode to advanced non-inductive steady-state plasmas. In this paper we present the results obtained with the ASTRA, CRONOS, JINTRAC and TOPICS codes equipped with the Bohm/gyro-Bohm, CDBM and GLF23 transport models. The scenarios analysed here are: a standard ELMy H-mode, a hybrid scenario and a non-inductive steady state plasma, with operational parameters from the JT-60SA research plan. Several simulations of the scenarios under consideration have been performed with the above mentioned codes and transport models. The results from the different codes are in broad agreement and the main plasma parameters generally agree well with the zero dimensional estimates reported previously. The sensitivity of the results to different transport models and, in some cases, to the ELM/pedestal model has been investigated.

  19. Scenario research: Can the future be predicted?

    DEFF Research Database (Denmark)

    Stacey, Julia; Sonne, Anne-Mette

    2000-01-01

    Mr. Jensen sits at the computer in his office wondering what to cook for dinner. He browses through the web site of his usual supermarket. Today's menu is fish. He skims the recipe that also informs him when, where and how the fish was caught. The fish is quite expensive but it has a story to tel...... and supplemented at workshops - one for each of the four sectors. Experts from industry, trade organisations, retailing, authorities and other interested parties participated....... of the project has been to develop scenarios for four sectors of the Danish food industry - meat, dairy, fish and fruit and vegetables - for 2010. The scenarios are put together with the purpose of making the food industry and food research reflect on which demands their competencies will be met with in various...... possible futures. In the process of creating the scenarios, researchers at MAPP and the Danish Technical University formulated mini scenarios based on their research. The scenarios were used as inspiration in discussions with experts from industry, trade organisations, authorities etc. and later discussed...

  20. Energy scenarios for the 21. century

    International Nuclear Information System (INIS)

    Lauerman, V.

    2002-01-01

    The Canadian Energy Research Institute (CERI) has adopted a scenario approach in developing its energy outlook to 2025. These scenarios can be used in developing strategies to optimize opportunities and avoid the dangers that often accompany the more deterministic approach to forecasting. The scenarios are not predictions, but are instead feasible outcomes for the future. They encompass 5 major areas of uncertainty for the world energy market through 2025 that impact energy demand and fuel mix. These include the economy, technology, energy policy, resource availability, and market structure. The drivers for the energy scenarios are the environment, demography, economics, culture geopolitics and technology. The paper referred to the world energy market, the OECD energy markets, the non-OECD energy markets and the FSU energy markets under 3 energy scenarios including: (1) the material world in which the new economy drives the global economy, (2) a very dark Orwellian world in which there is a rise in terrorism and a breakdown in international cooperation, and (3) a utopia in which the major powers become increasingly serious about achieving sustainable development. 22 refs., 48 figs

  1. Forestry: Prospective Scenarios for Generating Eletricity

    Directory of Open Access Journals (Sweden)

    Henrique Dias Blois

    2017-05-01

    Full Text Available Forestry generates in all production segments a lot of waste which is a potential power source and an opportunity for electricity generation by the use of this material. Therefore, this study represents the construction of future scenarios for the power generation sector from alternative and renewable sources in the region of Vale do Taquari and Alto da Serra do Botucaraí, in the Northern-Central region of the Stat of Rio Grande do Sul, aiming for the application of waste and by-products from forestry present in a intensive and tendentious way in economic activities within the region. By way of prospective scenarios, one will be able to observe which events are impactful on the viability of an environmental project for recovery of forestry waste to generate electricity in the region. Thereby, we used the method described by Grumbach (2000, a methodology that prospects scenarios from the participation of experts, who collaborated analyzing and proposing events that impact as strengths and weaknesses, opportunities and threats and their interrelationships. Also, it was evident the degree of influence and dependence between the events, which create a matrix of cross impacts. Moreover, possible future scenarios have been constructed and analyzed for demonstrating that the study area has potential events that could serve as alternatives to the sector. However, no ideal scenario has been identified for the next five years, a fact that is due to the large amount of adverse events in six out of the ten final events.

  2. Determination of Realistic Fire Scenarios in Spacecraft

    Science.gov (United States)

    Dietrich, Daniel L.; Ruff, Gary A.; Urban, David

    2013-01-01

    This paper expands on previous work that examined how large a fire a crew member could successfully survive and extinguish in the confines of a spacecraft. The hazards to the crew and equipment during an accidental fire include excessive pressure rise resulting in a catastrophic rupture of the vehicle skin, excessive temperatures that burn or incapacitate the crew (due to hyperthermia), carbon dioxide build-up or accumulation of other combustion products (e.g. carbon monoxide). The previous work introduced a simplified model that treated the fire primarily as a source of heat and combustion products and sink for oxygen prescribed (input to the model) based on terrestrial standards. The model further treated the spacecraft as a closed system with no capability to vent to the vacuum of space. The model in the present work extends this analysis to more realistically treat the pressure relief system(s) of the spacecraft, include more combustion products (e.g. HF) in the analysis and attempt to predict the fire spread and limiting fire size (based on knowledge of terrestrial fires and the known characteristics of microgravity fires) rather than prescribe them in the analysis. Including the characteristics of vehicle pressure relief systems has a dramatic mitigating effect by eliminating vehicle overpressure for all but very large fires and reducing average gas-phase temperatures.

  3. Possible climate change over Eurasia under different emission scenarios

    Science.gov (United States)

    Sokolov, A. P.; Monier, E.; Gao, X.

    2012-12-01

    In an attempt to evaluate possible climate change over EURASIA, we analyze results of six AMIP type simulations with CAM version 3 (CAM3) at 2x2.5 degree resolution. CAM3 is driven by time series of sea surface temperatures (SSTs) and sea ice obtained by running the MIT IGSM2.3, which consists of a 3D ocean GCM coupled to a zonally-averaged atmospheric climate-chemistry model. In addition to changes in SSTs, CAM3 is forced by changes in greenhouse gases and ozone concentrations, sulfate aerosol forcing and black carbon loading calculated by the IGSM2.3. An essential feature of the IGSM is the possibility to vary its climate sensitivity (using a cloud adjustment technique) and the strength of the aerosol forcing. For consistency, new modules were developed in CAM3 to modify its climate sensitivity and aerosol forcing to match those used in the simulations with the IGSM2.3. The simulations presented in this paper were carried out for two emission scenarios, a "Business as usual" scenario and a 660 ppm of CO2-EQ stabilization, which are similar to the RCP8.5 and RCP4.5 scenarios, respectively. Values of climate sensitivity used in the simulations within the IGSM-CAM framework are median and the bounds of the 90% probability interval of the probability distribution obtained by comparing the 20th century climate simulated by different versions of the IGSM with observations. The associated strength of the aerosol forcing was chosen to ensure a good agreement with the observed climate change over the 20th century. Because the concentration of sulfate aerosol significantly decreases over the 21st century in both emissions scenarios, climate changes obtained in these simulations provide a good approximation for the median, and the 5th and 95th percentiles of the probability distribution of 21st century climate change.

  4. RESGen: Renewable Energy Scenario Generation Platform

    DEFF Research Database (Denmark)

    Iversen, Jan Emil Banning; Pinson, Pierre

    2016-01-01

    studies remains. Consequently, our aim here is to propose an open-source platform for space-time probabilistic forecasting of renewable energy generation (wind and solar power). This document covers both methodological and implementation aspects, to be seen as a companion document for the open......-source scenario generation platform. It can generate predictive densities, trajectories and space-time interdependencies for renewable energy generation. The underlying model works as a post-processing of point forecasts. For illustration, two setups are considered: the case of day-ahead forecasts to be issued......Space-time scenarios of renewable power generation are increasingly used as input to decision-making in operational problems. They may also be used in planning studies to account for the inherent uncertainty in operations. Similarly using scenarios to derive chance-constraints or robust...

  5. Nuclear Futures Analysis and Scenario Building

    International Nuclear Information System (INIS)

    Arthur, E.D.; Beller, D.; Canavan, G.H.; Krakowski, R.A.; Peterson, P.; Wagner, R.L.

    1999-01-01

    This LDRD project created and used advanced analysis capabilities to postulate scenarios and identify issues, externalities, and technologies associated with future ''things nuclear''. ''Things nuclear'' include areas pertaining to nuclear weapons, nuclear materials, and nuclear energy, examined in the context of future domestic and international environments. Analysis tools development included adaptation and expansion of energy, environmental, and economics (E3) models to incorporate a robust description of the nuclear fuel cycle (both current and future technology pathways), creation of a beginning proliferation risk model (coupled to the (E3) model), and extension of traditional first strike stability models to conditions expected to exist in the future (smaller force sizes, multipolar engagement environments, inclusion of actual and latent nuclear weapons (capability)). Accomplishments include scenario development for regional and global nuclear energy, the creation of a beginning nuclear architecture designed to improve the proliferation resistance and environmental performance of the nuclear fuel cycle, and numerous results for future nuclear weapons scenarios

  6. KTM Tokamak operation scenarios software infrastructure

    Energy Technology Data Exchange (ETDEWEB)

    Pavlov, V.; Baystrukov, K.; Golobkov, YU.; Ovchinnikov, A.; Meaentsev, A.; Merkulov, S.; Lee, A. [National Research Tomsk Polytechnic University, Tomsk (Russian Federation); Tazhibayeva, I.; Shapovalov, G. [National Nuclear Center (NNC), Kurchatov (Kazakhstan)

    2014-10-15

    One of the largest problems for tokamak devices such as Kazakhstan Tokamak for Material Testing (KTM) is the operation scenarios' development and execution. Operation scenarios may be varied often, so a convenient hardware and software solution is required for scenario management and execution. Dozens of diagnostic and control subsystems with numerous configuration settings may be used in an experiment, so it is required to automate the subsystem configuration process to coordinate changes of the related settings and to prevent errors. Most of the diagnostic and control subsystems software at KTM was unified using an extra software layer, describing the hardware abstraction interface. The experiment sequence was described using a command language. The whole infrastructure was brought together by a universal communication protocol supporting various media, including Ethernet and serial links. The operation sequence execution infrastructure was used at KTM to carry out plasma experiments.

  7. xLPR Scenario Analysis Report.

    Energy Technology Data Exchange (ETDEWEB)

    Eckert-Gallup, Aubrey Celia [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lewis, John R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Brooks, Dusty Marie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Martin, Nevin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hund, Lauren [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Clark, Andrew Jordan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Mariner, Paul [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-03-01

    This report describes the methods, results, and conclusions of the analysis of 11 scenarios defined to exercise various options available in the xLPR (Extremely Low Probability of Rupture) Version 2 .0 code. The scope of the scenario analysis is three - fold: (i) exercise the various options and components comprising xLPR v2.0 and defining each scenario; (ii) develop and exercise methods for analyzing and interpreting xLPR v2.0 outputs ; and (iii) exercise the various sampling options available in xLPR v2.0. The simulation workflow template developed during the course of this effort helps to form a basis for the application of the xLPR code to problems with similar inputs and probabilistic requirements and address in a systematic manner the three points covered by the scope.

  8. Energy scenarios for hydrogen production in Mexico

    International Nuclear Information System (INIS)

    Ortega V, E.; Francois L, J. L.

    2009-10-01

    The hydrogen is a clean and very efficient fuel, its combustion does not produce gases of greenhouse effect, ozone precursors and residual acids. Also the hydrogen produced by friendly energy sources with the environment like nuclear energy could help to solve the global problems that it confronts the energy at present time. Presently work fuel cycles of hydrogen production technologies in Mexico are judged, by means of a structured methodology in the concept of sustainable development in its social, economic and environmental dimensions. The methodology is divided in three scenarios: base, Outlook 2030 and capture of CO 2 . The first scenario makes reference to cycles analysis in a current context for Mexico, the second taking in account the demand projections reported by the IAEA in its report Outlook and the third scenario, capture of CO 2 , the technologies are analyzed supposing a reduction in capture costs of 75%. Each scenario also has four cases (base, social, environmental and economic) by means of which the cycles are analyzed in the dimensions of sustainable development. For scenarios base and capture, results show that combination nuclear energy- reformed of gas it is the best alternative for cases base and economic. For social case, the evaluated better technology is the hydraulics, and for environmental case, the best option is represented by the regenerative thermochemistry cycles. The scenario Outlook 2030 show a favorable tendency of growth of renewable sources, being the aeolian energy the best technology evaluated in the cases base and environmental, the hydraulics technology in the social case and in the economic case the reformed of natural gas that uses nuclear heat. (Author)

  9. Atmospheric circulation and hydroclimate impacts of alternative warming scenarios for the Eocene

    Science.gov (United States)

    Carlson, Henrik; Caballero, Rodrigo

    2017-08-01

    Recent work in modelling the warm climates of the early Eocene shows that it is possible to obtain a reasonable global match between model surface temperature and proxy reconstructions, but only by using extremely high atmospheric CO2 concentrations or more modest CO2 levels complemented by a reduction in global cloud albedo. Understanding the mix of radiative forcing that gave rise to Eocene warmth has important implications for constraining Earth's climate sensitivity, but progress in this direction is hampered by the lack of direct proxy constraints on cloud properties. Here, we explore the potential for distinguishing among different radiative forcing scenarios via their impact on regional climate changes. We do this by comparing climate model simulations of two end-member scenarios: one in which the climate is warmed entirely by CO2 (which we refer to as the greenhouse gas (GHG) scenario) and another in which it is warmed entirely by reduced cloud albedo (which we refer to as the low CO2-thin clouds or LCTC scenario) . The two simulations have an almost identical global-mean surface temperature and equator-to-pole temperature difference, but the LCTC scenario has ˜ 11 % greater global-mean precipitation than the GHG scenario. The LCTC scenario also has cooler midlatitude continents and warmer oceans than the GHG scenario and a tropical climate which is significantly more El Niño-like. Extremely high warm-season temperatures in the subtropics are mitigated in the LCTC scenario, while cool-season temperatures are lower at all latitudes. These changes appear large enough to motivate further, more detailed study using other climate models and a more realistic set of modelling assumptions.

  10. Atmospheric circulation and hydroclimate impacts of alternative warming scenarios for the Eocene

    Directory of Open Access Journals (Sweden)

    H. Carlson

    2017-08-01

    Full Text Available Recent work in modelling the warm climates of the early Eocene shows that it is possible to obtain a reasonable global match between model surface temperature and proxy reconstructions, but only by using extremely high atmospheric CO2 concentrations or more modest CO2 levels complemented by a reduction in global cloud albedo. Understanding the mix of radiative forcing that gave rise to Eocene warmth has important implications for constraining Earth's climate sensitivity, but progress in this direction is hampered by the lack of direct proxy constraints on cloud properties. Here, we explore the potential for distinguishing among different radiative forcing scenarios via their impact on regional climate changes. We do this by comparing climate model simulations of two end-member scenarios: one in which the climate is warmed entirely by CO2 (which we refer to as the greenhouse gas (GHG scenario and another in which it is warmed entirely by reduced cloud albedo (which we refer to as the low CO2–thin clouds or LCTC scenario . The two simulations have an almost identical global-mean surface temperature and equator-to-pole temperature difference, but the LCTC scenario has  ∼  11 % greater global-mean precipitation than the GHG scenario. The LCTC scenario also has cooler midlatitude continents and warmer oceans than the GHG scenario and a tropical climate which is significantly more El Niño-like. Extremely high warm-season temperatures in the subtropics are mitigated in the LCTC scenario, while cool-season temperatures are lower at all latitudes. These changes appear large enough to motivate further, more detailed study using other climate models and a more realistic set of modelling assumptions.

  11. Removal of arsenate by ferrihydrite via surface complexation and surface precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Xiuli [Department of Environment Engineering, College of the Environment and Ecology, and The Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, Xiamen University, Xiamen (China); Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, and The Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen (China); Peng, Changjun; Fu, Dun; Chen, Zheng [Department of Environment Engineering, College of the Environment and Ecology, and The Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, Xiamen University, Xiamen (China); Shen, Liang [Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, and The Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen (China); Li, Qingbiao [Department of Environment Engineering, College of the Environment and Ecology, and The Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, Xiamen University, Xiamen (China); Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, and The Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen (China); Ouyang, Tong, E-mail: yz3t@xmu.edu.cn [Department of Environment Engineering, College of the Environment and Ecology, and The Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, Xiamen University, Xiamen (China); Wang, Yuanpeng, E-mail: wypp@xmu.edu.cn [Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, and The Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen (China)

    2015-10-30

    Graphical abstract: - Highlights: • Surface complexation and surface precipitation of As on ferrihydrite happen at pH 3–6. • The formation of surface precipitation enhanced As(V) adsorption. • The dissolved Fe{sup 3+} had a good linear relationship with the amount of arsenate re-adsorption. - Abstract: In this study, macroscopic and spectroscopic experimental methods accurately modeled the sorption process of arsenate on ferrihydrite. EXAFS, X-ray diffraction and infrared (IR) spectroscopy indicated that the behavior of As(V) adsorption onto ferrihydrite took place mainly via surface complexation and surface precipitation at acidic pH (3.0–6.0), while the surface precipitation was dominated at longer time intervals and higher Fe{sup 3+} concentration. The macroscopic competitive adsorption experiment between arsenate with phosphate indicated two types of adsorption sites existing on the surface of ferrihydrite, i.e., non-exchangeable sites, which are responsible for a rapid surface complex formation; and exchangeable sites for a slow build-up of surface precipitates. In the slow build-up precipitates, the As(V) surface coverage (mmol/g) exhibited a good linear relationship (R{sup 2} = 0.952) with the amount of dissolved Fe{sup 3+}. Three steps are involved during the process of surface precipitation, i.e., (1) an initial uptake of As(V) via surface complexation; (2) re-adsorption of Fe{sup 3+} leaching from ferrihydrite on the surface complex; and (3) As(V) adsorption via surface complexation again and finally forming the surface precipitate.

  12. The Impact of Gamification - Recommending Education Scenarios

    Directory of Open Access Journals (Sweden)

    Kai Erenli

    2013-01-01

    Full Text Available Many students play (computer games in their leisure time, thus acquiring skills which can easily be utilized when it comes to teaching more sophisticated knowledge. Nevertheless many educators today are wasting this opportunity. Some have evaluated gaming scenarios and methods for teaching students and have created the term “gamification”. This paper describes the history of this new term and explains the possible impact on teaching. It will take well-researched facts into consideration to discuss the potential of games. Moreover, scenarios will be illustrated and evaluated for educators to adopt and use on their own.

  13. The other radios: Alternative scenario in Peru

    Directory of Open Access Journals (Sweden)

    Carlos Rivadeneyra-Olcese

    2009-10-01

    Full Text Available Peruvian radio shows a huge diversity in direct proportion to its multiculturality, the same which shows a process full of different influences of social actor which have produced a complex and extremely rich scenario, that is also filled with opportunities and challenges. Beyond the great capital commercial radio are the other radios, small companies, provincial, from church or the mayor or small business owners sons of folkloric melomania, different actors with a passion to establish a new media. The multiple motivations produce a scenario with many types of radio that we wishes to start knowing.

  14. Scenarios of Expansion to Electric Generation Capacity

    Directory of Open Access Journals (Sweden)

    José Somoza-Cabrera

    2017-06-01

    Full Text Available We show the building scenarios of expansion to electric generation capacity enough to supply the demand to 2050. We were using the LEAP facility (Long-range Energy Alternatives Planning System, to simulate dispatch of electricity at minimum cost. Finally, we show the cost-benefice analysis of the technologies availability, included externality and CO2 emission limited. However that we included the externals cost in this analysis, it results insufficient to closed gap between fossil and renewable technologies of electric generation. Nevertheless, in some opportunities the renewable options had very important participations in the minimal cost scenario of expansion.

  15. Modeling and Understanding Time-Evolving Scenarios

    Directory of Open Access Journals (Sweden)

    Riccardo Melen

    2015-08-01

    Full Text Available In this paper, we consider the problem of modeling application scenarios characterized by variability over time and involving heterogeneous kinds of knowledge. The evolution of distributed technologies creates new and challenging possibilities of integrating different kinds of problem solving methods, obtaining many benefits from the user point of view. In particular, we propose here a multilayer modeling system and adopt the Knowledge Artifact concept to tie together statistical and Artificial Intelligence rule-based methods to tackle problems in ubiquitous and distributed scenarios.

  16. Negatep: A Scenario for Combating Global Warming; Le scenario Negatep. Un scenario de lutte contre le rechauffement climatique

    Energy Technology Data Exchange (ETDEWEB)

    Acket, C.; Bacher, P. [Sauvons Le Climat, 92 - Boulogne Billancourt (France)

    2011-07-15

    There have been an increasing number of foresight exercises in the field of energy and global warming in recent years, as we have seen from the articles devoted to these questions by Futuribles in 2011 (both in this special issue and in the April number). It is certainly the case that the goals for greenhouse-gas emission reduction are rather ambitious, particularly in France, it being the aim of the 2005 French framework law on energy to reduce carbon gas discharges by a factor of four. Among these scenarios, the Negatep scenario developed by Claude Acket and Pierre Bacher from the 'Sauvons le climat' [Let's save the climate] Association proposes to achieve this ('factor 4') goal in France by 2050 by reducing fossil fuel use by 75% and replacing this as quickly as possible with electricity produced from non-carbon-gas-emitting sources - chiefly, nuclear power and renewables. The authors lay out their goals here, backed up by figures, comparing these with the reference scenario. They also show the path that must be followed to arrive at these goals, particularly in the residential and tertiary sectors, and in transport and industry (through control of needs and recourse to alternative energy sources). They close by comparing the Negatep scenario with two other more recent scenarios aimed also at reducing greenhouse gas emissions, on the one hand in Europe, and on the other in Germany. The comparison confirms that they were right to rely on electricity as a substitute for oil, but gives them cause for concern in respect of the consequences (formidable in their view) that the replacement of nuclear power and coal energy by intermittent renewable energies might have in Europe, both with regard to costs and to the effects on the power network. (authors)

  17. Maximising the Effectiveness of a Scenario Planning Process: Tips for Scenario Planners in Higher Education

    Science.gov (United States)

    Sayers, Nicola

    2011-01-01

    Scenario planning is a tool which can help organisations and people to think about, and plan for, the long-term future. In basic terms, it involves creating a number of in-depth scenarios (stories), each of which tells of a different possible future for an organisation or issue, and considering how each different future might influence…

  18. Biosphere scenario development. An interim report of an SKI, SSI, SKB working group

    International Nuclear Information System (INIS)

    1989-11-01

    The Swedish Nuclear Power Inspectorate and the Swedish Nuclear Fuel and Waste Management Co have initiated a project for the development of scenarios for the behaviour of radionuclides in high level waste following deep geological disposal. The main objective is to develop a general consensus of scenarios and conceptual models. Within the project a biosphere scenarios working group was initiated to consider specific questions of the biosphere. This report describes the results of the group's deliberations up to the end of July 1989. A methodology is presented for the development of biosphere scenarios which may be considered alongside scenarios for radionuclide behaviour in the near field and geosphere. Two major biosphere elements affecting processes in the surface environment have been recognised, climate and development. Alternative states for climate and level of development are suggested and each combination can be considered with one or more of a range of biosphere receptors, such as a river or a lake. The features, events and processes relevant to each receptor are presented. Consideration is then given to biosphere assumptions for both gradual and direct releases from the geosphere, as well as biosphere effects on the repository near field or geosphere. The amount of screening which can be done at this stage to limit the number of biosphere scenarios is small. However, considerable potential exists once more details are available for geosphere release scenarios. It may be appropriate to further develop biosphere scenarios, specific to each geosphere release scenario. It may also be appropriate to consider scenarios specifically in relation to the individual radionuclides which dominate geosphere releases. Both these possibilities could result in considerably reduced requirements for calculations

  19. Fracture Resistance of Endodontically Treated Teeth Restored with 2 Different Fiber-reinforced Composite and 2 Conventional Composite Resin Core Buildup Materials: An In Vitro Study.

    Science.gov (United States)

    Eapen, Ashly Mary; Amirtharaj, L Vijay; Sanjeev, Kavitha; Mahalaxmi, Sekar

    2017-09-01

    The purpose of this in vitro study was to comparatively evaluate the fracture resistance of endodontically treated teeth restored with 2 fiber-reinforced composite resins and 2 conventional composite resin core buildup materials. Sixty noncarious unrestored human maxillary premolars were collected, endodontically treated (except group 1, negative control), and randomly divided into 5 groups (n = 10). Group 2 was the positive control. The remaining 40 prepared teeth were restored with various direct core buildup materials as follows: group 3 teeth were restored with dual-cure composite resin, group 4 with posterior composite resin, group 5 with fiber-reinforced composite resin, and group 6 with short fiber-reinforced composite resin. Fracture strength testing was performed using a universal testing machine. The results were statistically analyzed by 1-way analysis of variance and the post hoc Tukey test. Fracture patterns for each sample were also examined under a light microscope to determine the level of fractures. The mean fracture resistance values (in newtons) were obtained as group 1 > group 6 > group 4 > group 3 > group 5 > group 2. Group 6 showed the highest mean fracture resistance value, which was significantly higher than the other experimental groups, and all the fractures occurred at the level of enamel. Within the limitations of this study, a short fiber-reinforced composite can be used as a direct core buildup material that can effectively resist heavy occlusal forces against fracture and may reinforce the remaining tooth structure in endodontically treated teeth. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  20. Scenario-based roadmapping assessing nuclear technology development paths for future nuclear energy system scenarios

    International Nuclear Information System (INIS)

    Van Den Durpel, Luc; Roelofs, Ferry; Yacout, Abdellatif

    2009-01-01

    Nuclear energy may play a significant role in a future sustainable energy mix. The transition from today's nuclear energy system towards a future more sustainable nuclear energy system will be dictated by technology availability, energy market competitiveness and capability to achieve sustainability through the nuclear fuel cycle. Various scenarios have been investigated worldwide each with a diverse set of assumptions on the timing and characteristics of new nuclear energy systems. Scenario-based roadmapping combines the dynamic scenario-analysis of nuclear energy systems' futures with the technology roadmap information published and analysed in various technology assessment reports though integrated within the nuclear technology roadmap Nuclear-Roadmap.net. The advantages of this combination is to allow mutual improvement of scenario analysis and nuclear technology roadmapping providing a higher degree of confidence in the assessment of nuclear energy system futures. This paper provides a description of scenario-based roadmapping based on DANESS and Nuclear-Roadmap.net. (author)

  1. Optimizing Decision Preparedness by Adapting Scenario Complexity and Automating Scenario Generation

    Science.gov (United States)

    Dunne, Rob; Schatz, Sae; Flore, Stephen M.; Nicholson, Denise

    2011-01-01

    Klein's recognition-primed decision (RPD) framework proposes that experts make decisions by recognizing similarities between current decision situations and previous decision experiences. Unfortunately, military personnel arQ often presented with situations that they have not experienced before. Scenario-based training (S8T) can help mitigate this gap. However, SBT remains a challenging and inefficient training approach. To address these limitations, the authors present an innovative formulation of scenario complexity that contributes to the larger research goal of developing an automated scenario generation system. This system will enable trainees to effectively advance through a variety of increasingly complex decision situations and experiences. By adapting scenario complexities and automating generation, trainees will be provided with a greater variety of appropriately calibrated training events, thus broadening their repositories of experience. Preliminary results from empirical testing (N=24) of the proof-of-concept formula are presented, and future avenues of scenario complexity research are also discussed.

  2. Wetting of the diamond surface

    International Nuclear Information System (INIS)

    Hansen, J.O.

    1987-01-01

    The surface conditions which lead to a wide variation in the wettability of diamond surfaces have been investigated using macroscopic surfaces to allow for the crystal anisotropy. A wetting balance method of calculating adhesion tension and hence contact angle has been used for diamonds having major faces near the [111] and [110] lattice planes. Three classes of behaviour have been identified. Surface analyses by Rutherford Backscattering of helium ions, X-ray Photoelectron Spectroscopy and Low Energy Electron Diffraction (LEED) have been used to define the role of the oxygen coverage of the surface in the transition I → O → H. Ferric ion has a hydrophilizing effect on the diamond surface, thought to be the consequence of attachment to the hydroxyl groups at the surface by a ligand mechanism. Other transition metal ions did not show this effect. The phenomenon of hydration of the surface, i.e. progressively more hydrophilic behaviour on prolonged exposure to liquid water, has been quantified. Imbibition or water penetration at microcracks are thought unlikely, and a water cluster build-up at hydrophilic sites is thought to be the best explanation. Dynamic studies indicate little dependence of the advancing contact angle on velocity for velocities up to 10 -4 m/s, and slight dependence of the receding contact angle. Hence advancing angles by this technique are similar to equilibrated contact angles found by optical techniques, but the receding angles are lower than found by other non-dynamic measurements

  3. Scenario-based table top simulations

    DEFF Research Database (Denmark)

    Broberg, Ole; Edwards, Kasper; Nielsen, J.

    2012-01-01

    This study developed and tested a scenario-based table top simulation method in a user-driven innovation setting. A team of researchers worked together with a user group of five medical staff members from the existing clinic. Table top simulations of a new clinic were carried out in a simple model...

  4. Transport Technologies and Policy Scenarios to 2050

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-10-15

    As part of the major WEC study on Scenarios to 2050, a specific investigation was undertaken on measures required in the transport sector to secure sustainable energy and sustainable mobility in the future. This report outlines the results conducted by a study group of international WEC transport experts and gives concrete policy recommendations to develop sustainable transport systems.

  5. SO2 emission scenarios of eastern China

    International Nuclear Information System (INIS)

    Qi, L.; Hao, J.; Lu, M.

    1995-01-01

    Under the National Key Project in Eighth Five-year Plan, a study was carried out on forecasting SO 2 emission from coal combustion in China, with a special emphasis on the eastern area. 3 scenarios, i.e. 'Optimistic', 'Pessimistic' and 'Business as Usual' scenarios were developed trying to cover changing scale of coal consumption and SO 2 emission from 1990 to 2020. A 'Top-down' approach was employed, and coal consumption elasticity was defined to project future economic growth and coal consumption. SO 2 emission scenarios were outlined, based on coal consumption, estimated sulfur content level and prospective SO 2 control situation. Emission level for each 1 degree longitude x 1 degree latitude grid cell within eastern China was also estimated to show geographical distribution of SO 2 sources. The results show that SO 2 emission in China will increase rapidly, if the current situation for energy saving and SO 2 control is maintained without improvement; measures enhanced reasonably with economic growth could stop further increase of emission by 2010. Realization of more encouraging objective to keep emission at even below 1990 level needs, however, more stringent options. The share of eastern China in the country's total emission would increase until 2000, while the general changing tendency would principally follow the scenarios of the whole country. 4 refs., 5 figs., 1 tab

  6. NIDI scenario. Strong population decline in China

    NARCIS (Netherlands)

    de Beer, J.A.A.

    2016-01-01

    United Nations projections assume that by the end of this century one third of the world population will live in India, China or Nigeria. While population growth in India will slow down and the population size of China will decline, population growth in Nigeria will accelerate. A new NIDI scenario

  7. NIDI scenario. Strong population decline in China

    OpenAIRE

    de Beer, J.A.A.

    2016-01-01

    United Nations projections assume that by the end of this century one third of the world population will live in India, China or Nigeria. While population growth in India will slow down and the population size of China will decline, population growth in Nigeria will accelerate. A new NIDI scenario projects less population growth in Nigeria and sharp population decline in China.

  8. Flooding Capability for River-based Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Curtis L. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Prescott, Steven [Idaho National Lab. (INL), Idaho Falls, ID (United States); Ryan, Emerald [Idaho State Univ., Pocatello, ID (United States); Calhoun, Donna [Boise State Univ., ID (United States); Sampath, Ramprasad [Centroid Labs., Los Angeles, CA (United States); Anderson, S. Danielle [Idaho National Lab. (INL), Idaho Falls, ID (United States); Casteneda, Cody [Boise State Univ., ID (United States)

    2015-10-01

    This report describes the initial investigation into modeling and simulation tools for application of riverine flooding representation as part of the Risk-Informed Safety Margin Characterization (RISMC) Pathway external hazards evaluations. The report provides examples of different flooding conditions and scenarios that could impact river and watershed systems. Both 2D and 3D modeling approaches are described.

  9. Probabilistic results for a mobile service scenario

    DEFF Research Database (Denmark)

    Møller, Jesper; Yiu, Man Lung

    We consider the following stochastic model for a mobile service scenario. Consider a stationary Poisson process in Rd, with its points radially ordered with respect to the origin (the anchor); if d = 2, the points may correspond to locations of e.g. restaurants. A user, with a location different...

  10. Use of simplifier scenarios for CRM training

    Science.gov (United States)

    Weatherly, D.

    1984-01-01

    Cockpit resource management (CRM) at Metro Airlines is discussed. The process by which the program of CRM training was initiated is mentioned. Management aspects of various flying scenarios are considered. The transfer of training from the classroom to the field is assessed.

  11. Biomass round bales infield aggregation logistic scenarios

    Science.gov (United States)

    Biomass bales often need to be aggregated (collected into groups and transported) to a field-edge stack for temporary storage for feedlots or processing facilities. Aggregating the bales with the least total distance involved is a goal of producers and bale handlers. Several logistics scenarios for ...

  12. Forlic deliverable 5.1: Persona scenarios

    NARCIS (Netherlands)

    Gijsbers, Govert; Leendertse, Matthijs; Leis, Miriam; Kirschner, Paul A.; Hoogveld, Bert; Stoyanov, Slavi; Weber, Mark

    2015-01-01

    This document describes nine persona scenarios. The outcomes of a group concept mapping (GCM) exercise were used as input to create nine personas. The basic data for each persona contains demographic information, its position in a three by three persona matrix, and an overview of the relevant

  13. National FCEV and Hydrogen Fueling Station Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Bush, Brian; Melaina, Marc

    2016-06-09

    This presentation provides a summary of the FY16 activities and accomplishments for NREL's national fuel cell electric vehicle (FCEV) and hydrogen fueling station scenarios project. It was presented at the U.S. Department of Energy Hydrogen and Fuel Cells Program 2016 Annual Merit Review and Peer Evaluation Meeting on June 9, 2016, in Washington, D.C.

  14. European Water Footprint Scenarios for 2050

    Directory of Open Access Journals (Sweden)

    A. Ertug Ercin

    2016-05-01

    Full Text Available This study develops water footprint scenarios for Europe for 2050, at the country level, based on projections regarding population and economic growth, production and trade patterns, consumption patterns (diets and bioenergy use and technological development. The objective is to estimate possible future changes in the green, blue and grey water footprint (WF of production and consumption, to analyze the main drivers of projected changes and to assess Europe’s future dependence on water resources elsewhere in the world. We develop four scenarios, considering globalization versus regional self-sufficiency, and development driven by economic objectives versus development driven by social and environmental objectives. The study shows that the most critical driver of change affecting Europe’s future WF is the consumption pattern. The WFs of both production and consumption in Western Europe increase under scenarios with high meat consumption and decrease with low-meat scenarios. Besides, additional water demands from increasing biofuel needs will put further pressure on European water resources. The European countries with a large ratio of external to total WF of consumption in 2000 decrease their dependencies on foreign water resources in 2050.

  15. Scenario study on the FBR deployment

    International Nuclear Information System (INIS)

    Ono, Kiyoshi; Kofuji, Hirohide; Otaki, Akira; Yonezawa, Shigeaki; Shinoda, Yoshihiko; Hirao, Kazunori; Ikegami, Tetsuo

    2000-12-01

    This study on success scenarios for the Fast Breeder Reactor (FBR) deployment was performed taking account of future situation of fossil, renewable and nuclear energies in Japan as well as the world from the viewpoints of the following four items; economics, environment, energy security and restriction of natural uranium resources. In the economics scenario, if carbon tax is added to generating cost of LNG, coal and oil and the economics of FBR cycle is competitive with LWR cycle in the future, FBR cycle will be expected to introduce as the middle and base load power plant. In the environment scenario, there is also any possibility that FBR cycle which can burn and transmute minor actinide and fission product elements will be introduced in order to reduce the burden of deposit facility and the toxicity of high-level waste. In the uranium resources restriction scenario, FBR cycle needs to be deployed at the latest in the middle of 21st century from the viewpoint of the restriction of natural uranium resources. This study was carried out in a part of JNC's feasibility study on commercialized FBR cycle system. (author)

  16. Integration of software for scenario exploration

    International Nuclear Information System (INIS)

    Oyamada, Kiyoshi; Ikeda, Takao

    1999-03-01

    The scenario exploration methodology using shadow models is a variation of the environmental simulation method. Key aspect of the scenario exploration is the use of shadow models which are not corresponding to any specific assumptions on physical processes and, instead, abstract their general features relevant to the effects on nuclide transport in a general manner so that benefit of using simulation approach can be maximized. In developing the shadow models, all the modelling options that have not yet been denied by the experts are kept and parametrized in a very general framework. This, in turn, enables one to treat various types of the uncertainty in performance assessment, i.e., scenario uncertainty, conceptual model uncertainty, mathematical model uncertainty and parameter uncertainty, in a common framework of uncertainty / sensitivity analysis. Objective of the current study is to review / modify the tools which have been developed separately and, thence, not fully consistent from one to the other and to integrate them into a unified methodology and software. Tasks for this are; 1. modification / integration of tools for scenario exploration of nuclide transport in the EBS and the near-field host rock, 2. verification of the software modified and integrated, 3. installation of the software at JNC. (author)

  17. Risk assessment of complex accident scenarios

    International Nuclear Information System (INIS)

    Kluegel, Jens-Uwe

    2012-01-01

    The use of methods of risk assessment in accidents in nuclear plants is based on an old tradition. The first consistent systematic study is considered to be the Rasmussen Study of the U.S. Nuclear Regulatory Commission, NRC, WASH-1400. Above and beyond the realm of nuclear technology, there is an extensive range of accident, risk and reliability research into technical-administrative systems. In the past, it has been this area of research which has led to the development of concepts of safety precautions of the type also introduced into nuclear technology (barrier concept, defense in depth, single-failure criterion), where they are now taken for granted as trivial concepts. Also for risk analysis, nuclear technology made use of methods (such as event and fault tree analyses) whose origins were outside the nuclear field. One area in which the use of traditional methods of probabilistic safety analysis is encountering practical problems is risk assessment of complex accident scenarios in nuclear technology. A definition is offered of the term 'complex accident scenarios' in nuclear technology. A number of problems are addressed which arise in the use of traditional PSA procedures in risk assessment of complex accident scenarios. Cases of complex accident scenarios are presented to demonstrate methods of risk assessment which allow robust results to be obtained even when traditional techniques of risk analysis are maintained as a matter of principle. These methods are based on the use of conditional risk metrics. (orig.)

  18. Future Scenarios for Mobile Science Learning

    Science.gov (United States)

    Burden, Kevin; Kearney, Matthew

    2016-01-01

    This paper adopts scenario planning as a methodological approach and tool to help science educators reconceptualise their use of mobile technologies across various different futures. These "futures" are set out neither as predictions nor prognoses but rather as stimuli to encourage greater discussion and reflection around the use of…

  19. International scenarios of the Venezuelan oil industry

    International Nuclear Information System (INIS)

    Reinoso, Felipe; Irsay, Jorge E.

    1999-01-01

    The times of stability of the energy business, which characterized the 50s and the 60s came to their end in the 70s. From that moment on, new times have become times of quick changes and high uncertainty. In order to minimize the impact of the surprises that the future may bring, and so decrease the managers' decision making risk, many companies use the scenario planning process. The end purpose of scenario planning is the creation of an organization that will adapted to changes, a learning organization, that is able to identify the business environment un knows and to use this knowledge as one of its advantages. The present article shows the scenarios generated for the Venezuelan oil industry's strategic planning exercise for the 1999-2015 period. Theses scenarios are Consensus and Harmony, Regions and Environment, Conflicts and Decadence and Pragmatic Community. It is concluded from them that oil business success would be supported by differentiation as a secure, trusted and low cost producer; early oil and gas opportunities identification; Hemispherical integration and/or bilateral commercial agreements; oil and gas business portfolio diversification; and diversification to state-of-the-art technologies for renewable forms of energy

  20. Scenario evaluation of open pond microalgae production

    NARCIS (Netherlands)

    Slegers, P.M.; Lösing, M.B.; Wijffels, R.H.; Straten, van G.; Boxtel, van A.J.B.

    2013-01-01

    To evaluate microalgae production in large scale open ponds under different climatologic conditions, a model-based framework is used to study the effect of light conditions, water temperature and reactor design on trends in algae productivity. Scenario analyses have been done for two algae species