WorldWideScience

Sample records for onkalo tunnel olkiluoto

  1. ONKALO 3D tunnel seismic investigations, Olkiluoto 2013

    Energy Technology Data Exchange (ETDEWEB)

    Enescu, N.; Cosma, C.; Crawford, J. [Vibrometric Oy Cosma, Perttula (Finland)

    2014-10-15

    POSIVA Oy conducts bedrock investigations at the spent nuclear fuel final disposal site at Olkiluoto, in western Finland. The purpose of these efforts, which include a significant R and D component, is to ensure compliance with the requirements set forth for the long-term safety of final disposal. The excavation of the access tunnel to the repository hosts the ONKALO underground rock characterization facility. The investigations carried out in ONKALO focus on the bedrock and groundwater conditions prevailing on the final disposal site and how construction work affects them. Deformation zones and hydraulically conductive zones can limit the areas which are suitable for a deposition hole to be placed. The main objective of the tunnel seismic investigations presented here is to develop a seismic investigation technique for deposition area characterization. The field work consisted of 3 receiver lines using 3-component geophones and sources locations using the Vibsist-500 for 6 profiles, the Vibsist-20 for 1 profile (sparse), and a mechanical borehole hammer, MH-70, for 5 profiles for a total of 12 profiles. This investigation took place in the ONKALO demonstration area. Design of the seismic field work is based on previous tunnel seismic works in ONKALO (Cosma et al. 2008 and 2011) and pre-survey numerical modeling for field data and processing (Heinonen et al. 2013). The fieldwork was carried out in June 2013. Tomographic inversion of P-wave first arrival times was done on combined data sets, containing data from several shot-receiver configurations along tunnels and boreholes. The velocity distributions derived by tomographic inversion were verified by comparison with the forward modeled profiles. The Image Point (IP) migration method is characterized by is its ability to accumulate reflection events measured in the time distance data sets into points in the IP domain, which permits the enhancement of coherent backscattered events. The result of the 3D IP migration

  2. Core drilling of drillholes ONK-PVA9 and ONK-PVA10 in ONKALO at Olkiluoto 2011

    Energy Technology Data Exchange (ETDEWEB)

    Toropainen, V. [Suomen Malmi Oy, Espoo (Finland)

    2011-10-15

    Suomen Malmi Oy (Smoy) core drilled two drillholes for groundwater monitoring stations in ONKALO at Eurajoki, Olkiluoto in 2011. The groundwater monitoring stations are used for monitoring changes in groundwater conditions. The drillhole ONK-PVA9 was drilled in March 2011 and the drillhole ONK-PVA10 in June 2011. The lengths of the drillholes are 15.95 and 20.10 m respectively. The drillholes are 75.7 mm by diameter. The drillhole ONK-PVA9 was drilled in a niche of the access tunnel at chainage 4366 and the ONK-PVA10 in the access tunnel wall at chainage 3851. The hydraulic DE 130 drilling rig was used. The drilling water was taken from the ONKALO drilling water pipeline and premixed sodium fluorescein was used as a label agent in the drilling water. The drillholes were measured with EMS deviation survey tool. In addition to drilling the drillcores were logged and reported by geologist. Geological logging included the following parameters: lithology, foliation, fracture parameters, fractured zones, core loss, weathering, fracture frequency, RQD and rock quality. The main rock types in the drillholes are veined gneiss and pegmatitic granite. The average fracture frequencies in drill cores are 2.9 pcs/m (ONK-PVA9) and 2.3 pcs/m (ONK-PVA10) and the average RQD values 81.6 % and 96.2 % respectively. (orig.)

  3. Core drilling of hydco drillholes ONK-PP262 and ONK-PP274 in ONKALO at Olkiluoto 2010

    Energy Technology Data Exchange (ETDEWEB)

    Toropainen, V. [Suomen Malmi Oy, Espoo (Finland)

    2011-10-15

    Suomen Malmi Oy (Smoy) core drilled two drillholes for HYDCO-program in ONKALO at Eurajoki, Olkiluoto in 2010. The drillhole ONK-PP262 was drilled in May 2010 and the drillhole ONK-PP274 in December 2010. The lengths of the drillholes are 25.02 and 23.88 m respectively. The drillholes are 75.7 mm by diameter. The drillholes were drilled in the investigation niche 4 at the access tunnel chainage 3747. The hydraulic DE 130 drilling rig was used. The drilling water was taken from the ONKALO drilling water pipeline and premixed sodium fluorescein was used as a label agent in the drilling water. The drillholes were measured with EMS deviation survey tool. In addition to drilling the drillcores were logged and reported by geologist. Geological logging included the following parameters: lithology, foliation, fracture parameters, fractured zones, core loss, weathering, fracture frequency, RQD and rock quality. The main rock types in the drillholes are veined gneiss and pegmatitic granite. The average fracture frequencies in both drill cores are 1.4 pcs/m. The average RQD values in the drillcores are 97.2 % (ONK-PP262) and 98.6 % (ONK-PP274). (orig.)

  4. In-situ experiments to investigate rock matrix retention properties in ONKALO, Olkiluoto, Finland

    Energy Technology Data Exchange (ETDEWEB)

    Voutilainen, Mikko; Helariutta, Kerttuli [Helsinki Univ. (Finland). Dept. of Chemistry; Poteri, Antti [Technical Research Centre of Finland VTT (Finland); and others

    2015-07-01

    Spent nuclear fuel from nuclear power plants, owned by TVO (Teollisuuden Voima Oy) and Fortum, is planned to be disposed to a repository at a depth of more than 400 meters in the bedrock of Olkiluoto (Eurajoki, Finland). The repository system of multiple release barriers consists of both manmade and natural barriers. The surrounding rock acts as the last barrier if other barriers fail during passage of the millennia. Therefore, safe disposal of spent nuclear fuel requires information on the radionuclide transport and retention properties within the porous and water-containing rock matrix along the water conducting flow paths. To this end, various types of experiments are being performed and planned within ONKALO, the underground rock characterization facility in Olkiluoto, as part of the project @''rock matrix REtention PROperties'' (REPRO). The research site is located at a depth of 420 meters close to the repository site. The aim is to study the diffusion and sorption properties of nuclear compounds in the rock matrix under real in-situ conditions. The first in-situ experiment was performed during 2012 using HTO, Na-22, Cl-36 and I-125 as tracer nuclides. Breakthrough curves show retention and asymptotic behavior that are in-line with those caused by matrix diffusion and sorption were observed in their breakthrough curves. Weak sorption was also observed in the breakthrough curves of Na-22 and I-125.

  5. Core drilling of REPRO drillholes in ONKALO at Olkiluoto 2010-2011

    Energy Technology Data Exchange (ETDEWEB)

    Toropainen, V. [Suomen Malmi Oy, Espoo (Finland)

    2012-05-15

    Suomen Malmi Oy (Smoy) core drilled ten drillholes for the Posiva's Experiments to investigate Rock Matrix Retention Properties (REPRO) in ONKALO at Eurajoki, 2010 - 2011. The drillholes are used for geological characterization, hydrological and geophysical studies and instrumenting in research for retention of radionuclides to rock matrix. The drillhole ONK-PP240 was drilled in March 2010 and the drillholes ONKPP318... 324 and ONK-PP326...327 in October - December 2011. The lengths of the drillholes range from 4.90 to 21.65 metres. The drillholes are 56.5 mm by diameter. The drillhole ONK-PP240 was drilled for pretesting in the investigation niche 4 at access tunnel chainage 3747 and the rest of the drillholes in the investigation niche 5 at access tunnel chainage 4219. The hydraulic DE 130 drilling rig was used. The starting directions of the close spaced drillholes were controlled with an aligner assembly to be as parallel as possible. The drilling water was taken from the ONKALO drilling water pipeline and premixed sodium fluorescein was used as a label agent in the drilling water. The drillholes were measured with EMS deviation survey tool. In addition to drilling the drillcores were logged and reported by geologist. Geological logging included the following parameters: lithology, foliation, fracture parameters, fractured zones, core loss, weathering, fracture frequency, RQD and rock quality. The main rock types in the drillholes are veined gneiss, pegmatitic granite and quartz gneiss (skarn rock). The average fracture frequency in drill cores is 1.2 pcs/m and the average RQD value 98.6 %. (orig.)

  6. Geological 3D model of the investigation niche in ONKALO, Olkiluoto, southwestern Finland

    Energy Technology Data Exchange (ETDEWEB)

    Koittola, N.

    2014-07-15

    The main goal of this Master of Science Thesis was to create a geological 3D-model of the investigation niche 3 and its surroundings. The model were created for the needs of the rock mechanical back analysis. This study is a part of Posiva's regional studies for characterization of the bedrock. Totally 4 models were created: lithological model, foliation model, fracture model, and physical rock property model. Besides the modeling, there was also made a study of the migmatite structures in the niche. Used geological and geophysical methods were drill core loggings, tunnel mapping, ground penetration radar, mise-a-la-masse and drill hole geophysics. Four rock types exist at the niche area: veined gneiss, pegmatite granite, diatexitic gneiss and quartz gneiss. The lithological units were modeled primary with the drill core loggings, tunnel mapping and ground penetrating radar. The major lithological units followed the main foliation direction (south dipping). So the continuations were fairly easy to model in the walls and roof, where the data was lacking. Foliation and fractures were modeled as discs, with mid-points at the measurement points of the structure. There were two main foliation directions 164/46 and 62/39. Fractures were more scattered but three fracture sets can be separated: 156/34, 270/85 and 342/83. The first set is mainly from the drill core loggings, second and third from tunnel mapping. Used methods in foliation model were drill core loggings, tunnel mapping and drill hole geophysics. In fracture model used data was from drill core loggings, tunnel mapping, mise-a-la-masse measurements and drill core geophysic. Four anomalous zones were detected with the drill hole geophysics. Three of these zones were associated with intensely fractured zones and one was connected to exceptionally high mica content in the gneiss. Rocks of Olkiluoto are divided into gneisses and magmatic rocks in the geological mapping. Actually almost all Olkiluoto

  7. Geometrical and mechanical properties of the fractures and brittle deformation zones based on the ONKALO tunnel mapping, 2400 - 4390 m tunnel chainage

    Energy Technology Data Exchange (ETDEWEB)

    Moenkkoenen, H.; Rantanen, T.; Kuula, H. [WSP Finland Oy, Helsinki (Finland)

    2012-05-15

    In this report, the rock mechanics parameters of fractures and brittle deformation zones have been estimated in the vicinity of the ONKALO area at the Olkiluoto site, western Finland. This report is an extension of the previously published report: Geometrical and Mechanical properties if the fractures and brittle deformation zones based on ONKALO tunnel mapping, 0-2400 m tunnel chainage (Kuula 2010). In this updated report, mapping data are from 2400-4390 m tunnel chainage. Defined rock mechanics parameters of the fractures are associated with the rock engineering classification quality index, Q', which incorporates the RQD, Jn, Jr and Ja values. The friction angle of the fracture surfaces is estimated from the Jr and Ja numbers. There are no new data from laboratory joint shear and normal tests. The fracture wall compressive strength (JCS) data are available from the chainage range 1280-2400 m. Estimation of the mechanics properties of the 24 brittle deformation zones (BDZ) is based on the mapped Q' value, which is transformed to the GSI value in order to estimate strength and deformability properties. A component of the mapped Q' values is from the ONKALO and another component is from the drill cores. In this study, 24 BDZs have been parameterized. The location and size of the brittle deformation are based on the latest interpretation. New data for intact rock strength of the brittle deformation zones are not available. (orig.)

  8. Comparable investigation of the molecular size distribution and the amount of humic substances isolated from ONKALO, Olkiluoto, 2011

    Energy Technology Data Exchange (ETDEWEB)

    Luste, S.; Maekelae, J.; Manninen, P. [Ramboll Finland Oy, Espoo (Finland)

    2012-06-15

    The humic substances (HS) at groundwater from ONKALO, Olkiluoto were studied in order to determine the apparent molecular size distribution and the amount of humic substances. Humic substances were isolated from the water sample using DAX-8 resin and eluted with 0.1 M NaOH. The molecular size distribution was defined using high performance size exclusion chromatography (HPSEC) and ultraviolet (UV) and refractive index (RI) detector. In the SEC calibration (polystyrene sulfonate) sodium salts (PSS) were employed. Different eluents (NaNO{sub 3}, Na-acetate and asetonitrile) with phosphate buffer and distinct ionic strengths were studied in order to optimize the determination method. The amount of humic substances was determined using total organic carbon (TOC) measurements. The results were compared with the previous ones in order to find out the variation of different methods (HPSEC) and to follow up the HS quantity (TOC). The method developed during the study is considered to be suitable for the HS molecular size distribution follow up, although the method development is suggested to be continued. (orig.)

  9. Core drilling of boreholes ONK-KR1, ONK-KR2, ONK-KR3, ONK-KR4 and ONK-PVA1 in ONKALO at Olkiluoto 2005

    Energy Technology Data Exchange (ETDEWEB)

    Rautio, T. [Suomen Malmi Oy, Espoo (Finland)

    2005-11-15

    Posiva Oy submitted am application for the Decision in Principle (the final disposal facility for spent nuclear fuel at Olkiluoto, Eurajoki) to the Finnish Government in May 1999. A positive decision was made at the end of 2000 by the Government The Finnish Parliament ratified the Decision in Principle in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, ONKALO, will be constructed. The investigation programme on the influence of grouting in ground-water chemistry will be started by Posiva. The programme consists of long-term and short-term effects of grouting and the influence of grouting at different distances from the tunnel on groundwater conditions. As a part of this Suomen Malmi oy (Smoy) core drilled four boreholes in ONKALO. The identification numbers of thee boreholes are ONK-KR1, ONK-KR2, ONK-KR3 and ONK-KR4. An additional borehole ONK-PVA1 was core drilled for long-term monitoring purposes in a place where no grouting is planned to be done.The diameter of the borehole sis 75.7 mm A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. The volume of the drilling water and the returning water were recorded as well as the pressure of the drilling water. The objective of these measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The volume of the used drilling water was about 16 m{sup 3} and the measured volume of the returning water was about 11 dm{sup 3} in boreholes. The deviation of the boreholes was measured with the deviation measuring instrument EMS. The main rock types are migmatitic mica gneiss and granite. Filled fractures are most common type of fractures. The average fracture frequency of the boreholes varies from 0.6 to 3.1 pcs/m. The average RQD

  10. Analysis of hydrogeological flow responses in Olkiluoto

    Energy Technology Data Exchange (ETDEWEB)

    Ahokas, H.; Rouhiainen, P.; Komulainen, J.; Poellaenen, J. [Poeyry Finland Oy, Vantaa (Finland)

    2014-04-15

    As part of the programme for the final disposal of spent nuclear fuel, an analysis of the flow responses caused by ONKALO leakages or other activities on the site has been compiled. Leakages into ONKALO or other activities, such as pumping in connection with groundwater sampling, cause changes in flow conditions in adjacent drillholes. Flows in open drillholes have been measured with the PFL-tool (PFL-DIFF), several times in some holes, as part of Olkiluoto Monitoring Programme (OMO) or in conjunction of interference test campaigns carried out in Olkiluoto. The main objective of the study is to analyse differences detected between flow measurements without pumping. PFL-measurements were started in 1997 and all the holes have been measured. In total, measurements have been repeated in 32 holes, which enables a study of possible changes. The development of interpretation methods to detect and quantify flow changes was an important part of this work. The determination of the exact flow response is a challenging task. Changes are caused in flow also by seasonal effects, which complicate an unambiguous analysis of the observed parameters. Overlapping activities (sinks) behind flow changes make the analysis difficult. In addition, the role of other open holes close to the observation hole can be significant. They may cause flow responses, which would not have been detected without their existence. Nevertheless, unambiguous flow responses caused by the pumping of a drillhole or leaking tunnels have been detected in scales from ca. 10 m to over 1 km. (orig.)

  11. Results of monitoring at Olkiluoto in 2013, rock mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, E. (ed.) [Saanio and Riekkola Oy, Helsinki (Finland)

    2014-10-15

    The rock mechanics monitoring at Olkiluoto concentrates on the assessment of potential tectonic movements and stability of the bedrock. The rock mechanics monitoring programme 2013 consisted of seismic measurements, GPS measurements, surface levelling measurements and temperature measurements at Olkiluoto and vicinity and displacement measurements, temperature measurements and visual tunnel observations made in the ONKALO. The Posiva's microseismic network consists of 17 seismic stations and 21 triaxial sensors. Five stations are in the ONKALO. In spite of few breaks the network operated continuously and well during 2013. The number of located events (436) was slightly more than in 2012, but much less than in 2011. Nearly half of the observed explosions (237) in 2013 occurred inside the seismic semi-regional area and especially inside the seismic ONKALO block (137). One small induced earthquake (M{sub L} = -1.8) was detected at the depth of 429 m and was probably associated with smaller branches of the brittle fracture zone (OL-BFZ045). According to the seismic monitoring the rock mass has been stable in 2013. The local GPS network consists of 18 stations. Six new stations were set up for permanent tracking during 2013 and in total 12 permanent stations are now operating continuously. Manual measurements were carried out twice in 2013. Most of the inner network baselines showed very small motions as in the previous years: 75% of change rates were smaller than 0.10 mm/y. Roughly one third of the change rates are statistically significant. The surface levelling network currently consists of 87 fixed measuring points. During 2013 all the measuring loops were measured. The results indicated local subsidence area in the ONKALO loop and the rising area in the VLJ loop. Mean deformation rate has been +0.05 mm/y. Only elevation of one benchmark in the GPS station loop has changed more than one millimetre. The continuous displacement measurements in the technical rooms

  12. Analysis of ONKALO water leakage mapping results

    Energy Technology Data Exchange (ETDEWEB)

    Ahokas, H.; Nummela, J; Turku, J. [Poeyry Finland Oy, Vantaa (Finland)

    2014-04-15

    As part of the programme for the final disposal of spent nuclear fuel, an analysis has been compiled of water leakage mapping performed in ONKALO. Leakage mapping is part of the Olkiluoto Monitoring Programme (OMO) and the field work has been carried out by Posiva Oy. The main objective of the study is to analyse differences detected between mapping campaigns carried out typically twice a year in 2005-2012. Differences were estimated to be caused by the differences in groundwater conditions caused by seasonal effects or by differences between the years. The effect of technical changes like shotcreting, postgrouting, ventilation etc. on the results was also studied. The development of the visualisation of mapping results was also an objective of this work. Leakage mapping results have been reported yearly in the monitoring reports of Hydrology with some brief comments on the detected differences. In this study, the development of the total area and the number of different leakages as well as the correlation of changes with shotcreting and grouting operations were studied. In addition, traces of fractures on tunnel surfaces, and the location of rock bolts and drain pipes were illustrated together with leakage mapping. In water leakage mapping, the tunnel surfaces are visually mapped to five categories: dry, damp, wet, dripping and flowing. Major changes were detected in the total area of damp leakages. It is likely that the increase has been caused by the condensation of warm ventilation air on the tunnel surfaces and the corresponding decrease by the evaporation of moisture into the dry ventilation air. Shotcreting deep in ONKALO may also have decreased the total area of damp leakages. Changes in the total area and number of wet leakages correlate at least near the surface with differences in yearly precipitation. It is possible that strong rains have also caused a temporary increase in wet leakages. Dripping and wet leakages have been observed on average more

  13. Results of Monitoring at Olkiluoto in 2010. Rock Mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Lahti, M. (ed.); Siren, T.

    2011-12-15

    The rock mechanical monitoring at Olkiluoto concentrates on the assessment of potential tectonic movements and stability of the bedrock. The construction of ONKALO is not expected to induce large-scale movements of the rock blocks or affect the rate of isostatic uplift but the evaluation of any tectonic events is important for the safety assessment. The monitoring consists of seismic measurements, GPS measurements and precise levelling campaigns at Olkiluoto and vicinity and extensometer and convergence measurements carried out in ONKALO. Posiva established a local seismic network of six stations on the island of Olkiluoto in 2002. After that the number of seismic stations has increased gradually. In 2010 the permanent seismic network consists of 15 seismic stations and 20 triaxial sensors. The purpose of the microearthquake measurements at Olkiluoto is to improve understanding of the structure, behaviour and long term stability of the bedrock. The investigation area includes two target areas. The larger target area, called seismic semiregional area, covers the Olkiluoto Island and its surroundings. The purpose is to monitor explosions and tectonic earthquakes in regional scale inside that area. The smaller target area is called the seismic ONKALO block, which is a 2 km *2 km *2 km cube surrounding the ONKALO. It is assumed that all the expected excavation induced events occur within this volume. At the moment the seismic ONKALO block includes ten seismic stations. An additional task of monitoring is related to safeguarding of the ONKALO. This report gives the results of microseismic monitoring during 2010.

  14. Results of monitoring at Olkiluoto in 2009. Rock mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Lahti, M. (ed.) (Posiva Oy, Helsinki (Finland)); Hakala, M. (KMS Hakala Oy, Nokia (Finland))

    2010-09-15

    The rock mechanical monitoring at Olkiluoto concentrates on the assessment of potential tectonic movements and stability of the bedrock. The construction of ONKALO is not expected to induce large-scale movements of the rock blocks or affect the rate of isostatic uplift but the evaluation of any tectonic events is important for the safety assessment. The monitoring consists of seismic measurements, GPS measurements and precise levelling campaigns at Olkiluoto and vicinity and additionally extensometer and convergence measurements carried out in ONKALO. Posiva established a local seismic network of six stations on the island of Olkiluoto in 2002. The number of seismic stations has increased gradually being in 2009 altogether 14. The purpose of the microearthquake measurements at Olkiluoto is to improve understanding of the structure, behaviour and long term stability of the bedrock. The investigation area includes two target areas. The larger target area, called seismic semi-regional area, covers the Olkiluoto Island and its surroundings. The purpose is to monitor explosions and tectonic earthquakes in regional scale. The smaller target area is s called the seismic ONKALO block, which is a 2 km 2 km 2 km cube surrounding the ONKALO. All the expected excavation induced events assumingly occur within this volume. At the moment the seismic ONKALO block includes 10 seismic stations. An additional task of monitoring is related to safeguarding of the ONKALO. The seismic network has operated continuously in 2009 and during the year altogether 1256 events have been located in the Olkiluoto area. Most of them (1161) are explosions that occurred inside the seismic semi-regional area and especially inside the seismic ONKALO block (1135 events)

  15. In-situ failure test in the research tunnel at Olkiluoto

    Energy Technology Data Exchange (ETDEWEB)

    Autio, J.; Johansson, E.; Kirkkomaeki, T. [Saanio and Riekkola Consulting Engineers, Helsinki (Finland); Hakala, M. [Gridpoint Finland Oy (Finland); Heikkilae, E. [Helsinki Univ. of Technology, Otaniemi (Finland). Lab. of Rock Engineering

    2000-05-01

    A failure test suitable for execution in the Research Tunnel at Olkiluoto has been planned to study the failure of rock in-situ. The objectives of the in-situ failure test is to assess the applicability of numerical modelling codes and methods to the study of rock failure and associated crack propagation and to develop a novel technique to be used to determine the strength of rock in-situ. The objective of this study was to make a preliminary design of the failure test, assess the technical feasibility of the test and to give input information for further numerical modelling of the test. The design of the failure test is reported and results of preliminary modelling are given. The input information for future modelling includes a study of rock properties, fracture propagation in rock, in-situ stresses and the development of techniques for using the expanding agent to produce artificial stress field. The study showed that mechanical properties such as strength of gneissic tonalite, the main rock type in the Research Tunnel, depends highly on the orientation of schistocity. The in-situ failure test was shown to be technically feasible and a state of stress high enough to cause failure can be created artificially by using a proper expansive agent and design. (orig.)

  16. Correlation of transmissive fractures in pilot holes ONK-PH8 - PH12 and fracture traces mapped in ONKALO

    Energy Technology Data Exchange (ETDEWEB)

    Palmen, J.; Nummela, J.; Ahokas, H. [Poeyry Finland Oy, Vantaa (Finland)

    2014-05-15

    In a preceding study Posiva flow logging (PFL) with a 0.5 m test interval and 0.1 m steps has been used together with optical drillhole images and core logging fracture data for the exact determination of the depth of hydraulically conductive fractures in pilot holes. The fracture traces have been mapped from the ONKALO tunnel walls as a part of the systematic mapping. The mapping results has been digitized to a 3D tunnel layout in Surpac programme. The data integrity and fracture trace uniqueness has been verified by Datactica Oy and further collected to a database (RakokantaDatacticaPosiva20100607.mdb). Fractures mapped with leakage attribute have been defined as flowing, dripping, wet, or damp where the attribute is recorded. The fractures with no leakage attribute value appear to be non leaking. The water leaking surfaces on the ONKALO tunnel walls have been mapped sequentially and conclusively (once or twice a year) as a part of the Olkiluoto monitoring program (OMO) using an equal five step measure as used with fracture traces in systematic mapping. The PFL results correlated with core logging fracture data from the pilot holes ONK-PH8 - ONK-PH12 were in this work further correlated with the fractures mapped from the ONKALO tunnel walls. Each hydraulically conductive fracture of ONK-PH8 - ONK-PH12 was investigated and linked to ONKALO fracture of a coherent orientation and matching location, where such fracture trace was available. Also tunnel crosscutting fracture (TCF) data was used in combining, since the systematic mapping data was not yet available for the pilot holes ONK-PH11 and ONK-PH12 at the time of the evaluation. The main objective of the work was to identify the ONKALO fractures which correspond to the flow from fracture(s) identified with the PFL method in pilot holes and to collect basic information about the occurrence, frequency and orientation of water bearing fractures along the ONKALO tunnel. The correlated hydraulically conductive

  17. ONKALO rock mechanics model (RMM). Version 2.3

    Energy Technology Data Exchange (ETDEWEB)

    Haekkinen, T.; Merjama, S.; Moenkkoenen, H. [WSP Finland, Helsinki (Finland)

    2014-07-15

    The Rock Mechanics Model of the ONKALO rock volume includes the most important rock mechanics features and parameters at the Olkiluoto site. The main objective of the model is to be a tool to predict rock properties, rock quality and hence provide an estimate for the rock stability of the potential repository at Olkiluoto. The model includes a database of rock mechanics raw data and a block model in which the rock mechanics parameters are estimated through block volumes based on spatial rock mechanics raw data. In this version 2.3, special emphasis was placed on refining the estimation of the block model. The model was divided into rock mechanics domains which were used as constraints during the block model estimation. During the modelling process, a display profile and toolbar were developed for the GEOVIA Surpac software to improve visualisation and access to the rock mechanics data for the Olkiluoto area. (orig.)

  18. Analysis of temperature data at the Olkiluoto

    Energy Technology Data Exchange (ETDEWEB)

    Sedighi, M.; Bennett, D.; Masum, S.; Thomas, H. [Cardiff Univ. (United Kingdom); Johansson, E. [Saanio and Riekkola Oy, Helsinki (Finland)

    2014-03-15

    As part of the rock mechanics monitoring programme 2012 at Olkiluoto, temperature data have been recorded. Temperature data have been measured, collected and monitored at the Olkiluoto site and in ONKALO in various locations, by different methods and in conjunction with other investigations carried out at the site. This report provides a detailed description of the investigation and analysis carried out on temperature datasets. This report aims to provide a better understanding of the in-situ temperature of the rock and soil at the site. Three categories of datasets have been analysed and studied from the Posiva thermal monitoring programme. These consist of: (i) data collected from the various drillholes during geophysical logging and Posiva Flow Log (PFL) measurements, (ii) measurements in the ONKALO ramp, the investigation niche located at elevation -140 m and a technical room located at 437 m below the surface, and (iii) surface temperature measurements from four weather stations and four measurement ditches. Time-series data obtained from the groundwater temperature measurements during the 'Posiva Flow Log' (PFL) tests in drillholes OL-KR1 to KR55 at different depths and years have been analysed. Temperature at a depth of 400 m was found to be in the range of 10 to 11 deg C. The geothermal gradient obtained from the PFL data without pumping was found to be approximately 1.4 deg C/100m with relatively uniform temporal and spatial patterns at the repository depth, i.e. at 400 m.The geothermal gradient obtained from the results of the PFL measurements and geophysical loggings indicate similar temperature values at the repository depths, i.e. 400 m. The characteristics of the time series data related to the ONKALO measurements, have been obtained through a series of Non-uniform Discrete Fourier Transform analysis Datasets related to the various chainages and investigation niche at ONKALO have been studied. The largest variation in the temperature

  19. Results of monitoring at Olkiluoto in 2012. Environment

    Energy Technology Data Exchange (ETDEWEB)

    Haapanen, A. (ed.) [Haapanen Forest Consulting, Vanhakylae (Finland)

    2014-04-15

    In 2003, Posiva Oy presented a programme for monitoring at Olkiluoto during construction and operation of ONKALO. In 2012 the monitoring programme was updated to concern the years 2012-2018. Part of the monitoring is performed by the company running the nuclear power plants on the island, Teollisuuden Voima Oy (TVO). This Working Report presents the main results of Posiva's environmental monitoring programme on Olkiluoto Island in 2012. Results are presented under five topics: 1. Evolution of geosphere, 2. Biosphere modelling input data, 3. Interaction between surface environment and groundwater in bedrock, 4. Environmental impact and 5. Baseline of monitoring of radioactive releases. Concerning the evolution of geosphere, LIDAR-scannings were done in the Olkiluoto area in 2012. The acquired data can be used for elevation and other modelling purposes. The soil solution quality in 2012 was quite comparable to that in earlier years. Proximity of the sea and the young age of soils are seen in soil solution results. Biosphere modelling input data in 2012 included e.g. continuous tree litterfall and transpiration data, as well as updated game statistics and population estimates of fauna, a fishery survey from the River Eurajoki (2011) and basic monitoring data from Olkiluoto offshore properties. Interaction between surface environment and groundwater in bedrock includes e.g. weather and surface water monitoring data. Environmental impact analyses included e.g. monitoring of noise, air quality, effluent waters and private drilled wells. Noise monitoring in the vicinity of ONKALO showed that in the case of raised noise levels the sources are mainly the traffic on Olkiluodontie road, the air conditioning of ONKALO and occasional sources such as springtime bird sounds. Construction activities in the area were seen in increased amount of NO{sub 3}-N in the bulk deposition, and Al and Fe accumulating on needle surfaces in areas close to the rock piling and crushing area

  20. Geological discrete fracture network model for the Olkiluoto site, Eurajoki, Finland. Version 2.0

    Energy Technology Data Exchange (ETDEWEB)

    Fox, A.; Forchhammer, K.; Pettersson, A. [Golder Associates AB, Stockholm (Sweden); La Pointe, P.; Lim, D-H. [Golder Associates Inc. (Finland)

    2012-06-15

    This report describes the methods, analyses, and conclusions of the modeling team in the production of the 2010 revision to the geological discrete fracture network (DFN) model for the Olkiluoto Site in Finland. The geological DFN is a statistical model for stochastically simulating rock fractures and minor faults at a scale ranging from approximately 0.05 m to approximately 565m; deformation zones are expressly excluded from the DFN model. The DFN model is presented as a series of tables summarizing probability distributions for several parameters necessary for fracture modeling: fracture orientation, fracture size, fracture intensity, and associated spatial constraints. The geological DFN is built from data collected during site characterization (SC) activities at Olkiluoto, which is selected to function as a final deep geological repository for spent fuel and nuclear waste from the Finnish nuclear power program. Data used in the DFN analyses include fracture maps from surface outcrops and trenches, geological and structural data from cored drillholes, and fracture information collected during the construction of the main tunnels and shafts at the ONKALO laboratory. Unlike the initial geological DFN, which was focused on the vicinity of the ONKALO tunnel, the 2010 revisions present a model parameterization for the entire island. Fracture domains are based on the tectonic subdivisions at the site (northern, central, and southern tectonic units) presented in the Geological Site Model (GSM), and are further subdivided along the intersection of major brittle-ductile zones. The rock volume at Olkiluoto is dominated by three distinct fracture sets: subhorizontally-dipping fractures striking north-northeast and dipping to the east that is subparallel to the mean bedrock foliation direction, a subvertically-dipping fracture set striking roughly north-south, and a subvertically-dipping fracture set striking approximately east-west. The subhorizontally-dipping fractures

  1. GPS operations at Olkiluoto in 2011

    Energy Technology Data Exchange (ETDEWEB)

    Koivula, H.; Kallio, U.; Nyberg, S.; Jokela, J.; Poutanen, M. [Finnish Geodetic Institute, Masala (Finland)

    2012-06-15

    The Finnish Geodetic Institute has studied crustal deformations at Olkiluoto, Kivetty and Romuvaara in co-operation with Posiva Oy since 1995. At Olkiluoto a total of 32 GPS campaigns have been carried out at inner network since 1995 and 17 campaigns at outer network since 2003. Kivetty and Romuvaara were not measured in 2011. In the Olkiluoto inner network 80 percent of the estimated change rates are smaller than 0.10 mm/a. One third of the change rates are statistically significant. They are mainly related to the Olkiluoto permanent station (GPS1) and to the pillars GPS6 and GPS13. The change rates related to GPS6 are not realistic due to the site-specific changes affecting the time series. The maximum change rate (-0.20 mm/a {+-} 0.05 mm/a) is related to GPS13. The time series of GPS13 is half the length of other pillars and therefore, the change rates are more uncertain. In the Olkiluoto outer network the maximum and statistically significant change rate is between GPS1-GPS11 (0.39 mm/a {+-} 0.06 mm/a). Pillar GPS12 was not observed this year. The change rates of baselines GPS1-GPS14 and GPS1-GPS15 are first time statistically significant. The change rates indicate a small movement of the GPS1 pillar. The baseline GPS1-GPS11 crosses an old fracture zone locating in the direction of the Eurajoensalmi, which might be a reason for the deformation. On the other hand, the Onkalo excavations in the vicinity of the Olkiluoto permanent station (GPS1) may cause some movement. Electronic distance measurements have been performed at Olkiluoto at the baseline GPS7-GPS8 using the Mekometer since 2002. The measurements have been carried out simultaneously with GPS campaigns. Based on 19 measurements in 10 years, the trends of the two time series seems to be similar. Due to unmodelled or dismodelled geometrical offsets and the scale difference between GPS measurements and EDM there is about 0.3 mm difference between distances GPS7-GPS8 derived from GPS measurements and EDM

  2. geological mapping of the Onkalo open cut

    Energy Technology Data Exchange (ETDEWEB)

    Talikka, M. [Geological Survey of Finland, Espoo (Finland)

    2005-11-15

    Posiva Oy and Geological Survey of Finland carried out geological mapping of the ONKALO open cut in the latter half of the year 2004. The study area is located on the Olkiluoto Island in Eurajoki, SW Finland. The study included geological mapping, stereo-photography, and interpretation of 3D images. Fieldwork was carried out during the construction work. The main rock types are vein migmatite and grey gneiss with variation to granitic grey gneiss. The contacts of the rock types are gradual. The vein migmatite consists of fine- to medium-grained mica gneiss paleosome and granite or granite pegmatite neosome. The proportion of the neosome material varies between 15 and 35 percent and the neosome occurs as veins and bands up to ten centimetres in thickness. The granite I granite pegmatite is medium- to coarse-grained and not orientated. Main minerals in the mica gneiss are plagioclase, biotite, quartz, and in the granite / granite pegmatite potassium feldspar, plagioclase, and quartz. The grey gneiss is medium grained and fairly homogenous comprising mainly plagioclase, biotite, and quartz. The granitic grey gneiss contains also potassium feldspar crystals up to five cm in length. The rocks within the study area are generally well preserved. There is, however, a zone of strongly weathered rocks east of the ONKALO open cut. The main structural feature in the study area is S{sub 2} foliation, which is seen in the orientation of biotite grains. The degree of the foliation is weak to medium in the vein migmatite and weak to non-existence in the grey gneiss. The foliation (S{sub 2}) dips 20-70 deg to southeast with an average direction of 150/45 deg. The migmatisation took place during the second deformation phase and possibly proceeded along the lithologic layers. The neosome veins bend irregularly and folding is present in places. The fold axis of the small scale, isoclinal folds dip 50-70 deg to northeast. In fracture mapping a total of 231 fractures were measured

  3. ONKALO POSE experiment. Phase 1 and 2: execution and monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, E. [Saanio and Riekkola Oy, Helsinki (Finland); Siren, T. [Posiva Oy, Helsinki (Finland); Hakala, M. [KMS-Hakala Oy, Nokia (Finland); Kantia, P. [Geofcon Oy, Rovaniemi (Finland)

    2014-02-15

    Posiva has conducted in the ONKALO rock characterisation facility during 2010 - 2011 an in situ experiment named POSE (Posiva's Olkiluoto Spalling Experiment). The POSE experiment had three objectives: to establish the in situ spalling/damage strength of Olkiluoto migmatitic gneiss, to establish the state of in situ stress at the -345 m depth level, and to act as a Prediction-Outcome (P-O) exercise. The POSE experiment consisted of drilling with full-face boring machine two near fullscale deposition holes, diameter 1.52 m (compared to 1.75 m for the actual deposition holes), to a depth of 7.2 m, leaving a 0.9 m pillar between the holes. The holes were planned to be located in such way that maximum excavation-induced stresses could act in the pillar and damage could then take place. Boring of the two holes in 2010 was called Phase 1 (Pillar test). This was followed in 2011 by Phase 2 (Pillar heating test) where four heaters with a length of 7.5 m heated the test area to increase the stresses around the experimental holes. In the heating phase the other hole was back-filled with sand. The test was extensively monitored during the execution using temperature monitoring, strain gauge monitoring, video monitoring, microseismic monitoring and pressure monitoring. In addition, the holes were after the test measured using ground penetration radar (GPR) and 3D photogrammetry for detailed modelling. The outcomes from the test showed that no damage, except for three opened/sheared fractures, was noticed during the boring of the holes (Phase 1). Surface damage was, though, induced by heating (Phase 2). The damage was well localized around the holes and controlled by the foliation (mica rich layers) and rock type contacts which were known to be relatively weak. Surface type failures were not observed in the gneiss, but it was noticed in limited areas in the pegmatite-granite. The depths of the damaged areas due to heating were less than 100 mm. The depths and sizes of the

  4. Local seismic network at the Olkiluoto site. Annual report for 2011

    Energy Technology Data Exchange (ETDEWEB)

    Saari, J.; Malm, M. [AF-Consult Oy, Espoo (Finland)

    2012-06-15

    This report gives the results of microseismic monitoring during 2011. Excavation of the underground characterisation facility called ONKALO started in 2004. Before that, in February 2002, Posiva Oy established a local seismic network of six stations on the island of Olkiluoto. After that the number of seismic stations has increased gradually. In 2011 Posiva's permanent seismic network consists of 15 seismic stations and 20 triaxial sensors. The purpose of the microearthquake measurements at Olkiluoto is to improve understanding of the structure, behaviour and long term stability of the bedrock. The investigation area includes two target areas. The larger target area, called seismic semiregional area, covers the Olkiluoto Island and its surroundings. The purpose is to monitor explosions and tectonic earthquakes in regional scale inside that area. The smaller target area is called the seismic ONKALO block, which is a 2 km x 2 km x 2 km cube surrounding ONKALO. It is assumed that all the expected excavation induced events occur within this volume. At the moment the seismic ONKALO block includes ten seismic stations. An additional task of monitoring is related to safeguarding of the construction of ONKALO. The configuration of the seismic network as well as the software packages applied in data processing and analyses have remained during the previous year. The design model of ONKALO and the brittle fault zone model of the Olkiluoto of the seismic visualization package Jdi were upgraded in 2011. The network has operated nearly continuously. There was a 14 minutes and 30 second long operation failure in December 2011. That was the first network operation failure in five years. Altogether 1223 events have been located in the Olkiluoto area, in the reported time period. Most of them (1098) are explosions that occurred inside the seismic semiregional area and especially inside the seismic ONKALO block (1064 events). The magnitudes of the observed explosions inside the

  5. Local seismic network at the Olkiluoto site. Annual report 2002-2004

    Energy Technology Data Exchange (ETDEWEB)

    Saari, J. [Enprima Oy, Vantaa (Finland)

    2005-09-15

    In Olkiluoto, Posiva Oy has operated a local seismic network since February 2002. In the beginning, the network consisted of six seismic stations. Later, in June 2004, the seismic network was expanded with two new seismic stations. At that time started the excavation of the underground characterisation facility (the ONKALO) and the basic operation procedure was changed more suitable for the demands of the new situation. The purpose of the microearthquake measurements at Olkiluoto is to improve understanding of the structure, behaviour and long term stability of the bedrock. The studies include both tectonic and excavation-induced microearthquakes. An additional task of monitoring is related to safeguarding of the ONKALO. This report gives the results of microseismic monitoring during the years 2002 - 2004. Also the changes in the structure and the operation procedure of the network are described. The network has operated nearly continuously. The longest interruption occurred 16.-17.6.2004, when two new seismic stations were installed in the network and the operation procedure was changed. Altogether 757 events have been located in the Olkiluoto area. The magnitudes of the observed events range from ML = -3.5 to ML = 1.2. All of them are explosions or other artificial events. So far, none of the 757 observed events can be classified as microearthquakes. Five of the events have characteristics that make the origin of the recorded signal uncertain. They are quite unlikely microearthquakes, but they are not typical examples of artificial seismic signals either. When the experience and the data set of the Olkiluoto microearthquakes increase the identification of events will be more definite. Evidence of activity that would has influence on the safety of the ONKALO, have not found. (orig.)

  6. Modelling of the in situ stress state at Olkiluoto Site, Western Finland

    Energy Technology Data Exchange (ETDEWEB)

    Valli, J.; Kuula, H. [WSP Finland Oy, Helsinki (Finland); Hakala, M. [KMS Hakala Oy, Nokia (Finland)

    2011-06-15

    In order to determine the interaction of in situ stress and geological features at Olkiluoto with the ONKALO area under more specific focus, stress modelling work was launched in 2009. This entailed updating a previously used model geometry to suit current needs whilst also updating interpreted brittle deformation zones according to the data provided by Posiva in the beginning of 2010. The previous model geometry was originally used for seismic and glacial load simulations. Brittle deformation zones were updated in the model according to a new selection criterion which added a number of brittle deformation zones. Changes in the geometry of certain brittle deformation zones were also necessary to better fit the early 2010 interpretations from Posiva. Modelling goals were to clarify the effect of joint parameters on stress magnitude and orientation and which of the major brittle deformation zones detected in the ONKALO region could have potential effects on local in situ stress states. Additional goals included modelling the effect of several optional thrust boundary conditions and an ice-age. Compression from the northwest-southeast was used as the default approach whilst north-south, east-west and northeast-southwest were optional conditions. A simplified glaciation cycle was also simulated. Results were clear in demonstrating the critical effect of joint cohesion and joint friction angle, i.e. shear strength, on stress-geology interaction, essentially in this order of importance. The case that utilised both drillhole core-logging and ONKALO tunnel mapping results did not exhibit much if any stress-geology interactions as BFZ strength parameters were too high in order to allow any interactions to occur. The geometry and orientation of brittle deformation zones was found to be of significant importance; deformation zones with a shallow dip roughly in the direction of applied compression were optimal for causing stress rotations and the increase of stress magnitude

  7. Olkiluoto site description 2011

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-12-15

    This fourth version of the Olkiluoto Site Report, produced by the OMTF (Olkiluoto Modelling Task Force), updates the Olkiluoto Site Report 2008 with the data and knowledge obtained up to December 2010. A descriptive model of the site (the Site Descriptive Model, SDM), i.e. a model describing the geological and hydrogeological structure of the site, properties of the bedrock and the groundwater and its flow, and the associated interacting processes and mechanisms. The SDM is divided into six parts: surface system, geology, rock mechanics, hydrogeology, hydrogeochemistry and transport properties.

  8. Results of monitoring at Olkiluoto in 2013. Hydrology and hydrogeology

    Energy Technology Data Exchange (ETDEWEB)

    Vaittinen, T.; Ahokas, H.; Komulainen, J.; Nummela, J.; Pentti, E.; Turku, J. [Poeyry Finland Oy, Vantaa (Finland); Karvonen, T. [WaterHope, Helsinki (Finland); Aro, S.

    2014-12-15

    The impact of the construction of ONKALO is monitored by measuring and observing numerous different parameters related to hydrology, geochemistry, environment, rock mechanics and foreign materials. The Hydrological Monitoring Programme consists of the following parameters: groundwater level, hydraulic head, flow conditions in open drillholes, transverse flow, hydraulic conductivity, groundwater salinity (in situ EC), precipitation (including snow), sea-water level, surface flow (runoff), infiltration, ground frost, leakages in tunnels, and water balance in the tunnel system and in Korvensuo Reservoir. This Report focuses on hydrogeological parameters. Other parameters, like precipitation, ground frost etc. will be reported in the Monitoring Report of Environment. Updated monitoring program was introduced in the beginning of 2012. The updated program will be used for the period before repository operation. Only minor changes were implemented. Monitoring has been carried out according to plan. This Report presents the results for the year 2013. Excavation of the access tunnel was completed in 2012. Demonstration tunnels 3 and 4 were excavated and central tunnel 1 was continued from chainage 4366-22 m to chainage 4366-60 m in 2013. Total inflow into ONKALO down to chainage 4580 m including shaft ONK-KU2 down to level -437 m was on average 35 l/min in 2013. The mapping of water leakages and moisture conditions on the tunnel walls and the ceiling has been continued. The general pattern of leakages has remained similar during the construction of ONKALO. Most significant differences are caused by seasonal effects like condensation of warm ventilation air on tunnel walls and ceiling. The changes observed in the groundwater level in observation tubes in the overburden and in shallow drillholes in the bedrock are not necessarily caused by the construction of ONKALO. However, weak indications of a local decrease in groundwater level have been observed. Effects on the head

  9. Results of Monitoring at Olkiluoto in 2011. Environment

    Energy Technology Data Exchange (ETDEWEB)

    Haapanen, A. (ed.) [Haapanen Forest Consulting, Vanhakylae (Finland)

    2012-11-15

    This Working Report presents the main results of Posiva Oy's environmental monitoring programme on Olkiluoto Island in 2011. These summary reports have been published since 2005. The environmental monitoring system supervised by Posiva Oy produces input for biosphere modelling for long-term safety purposes as well as for monitoring the state of the environment during the construction (and later operation) of ONKALO underground rock characterization facility. Part of the monitoring is performed by the company running the nuclear power plants on the island, Teollisuuden Voima Oy (TVO). Monitoring has been carried out for varying periods of time depending on the sector: some monitoring activities performed by TVO originate from the 1970s and the repository-related environmental monitoring of Olkiluoto from the early 2000s. The monitoring programme evolves according to experiences gained from the modelling work and increased understanding of the site. Monitoring activities in 2011 proceeded according to the plans. The land-use of the island continues to change due to the construction work of OL3, ONKALO and related infrastructure, but the remaining natural environment resembles other coastal locations. The amount of nitrogen in the bulk deposition increased in 2011, whereas that of sulphur decreased. Some litterfall fractions showed higher Al and Fe values than earlier, likely caused by soil dust. Proximity of the sea is seen in wet deposition and soil solution results. Soil solution also reflects the young age of soils. Undestorey vegetation has shown no essential changes during the monitoring period. Mammalian fauna on the island is typical of coastal areas in Southwestern Finland. Game catches vary according to hunting pressure and natural variation in populations. The condition of the nearby sea is affected by the continuous land uplift, the shallowness of the area, the weather conditions, the general condition of the Bothnian Sea, the nutrient and sediment

  10. Refraction seismic surveys in the investigation trench TK3 area in Olkiluoto, Eurajoki 2004

    Energy Technology Data Exchange (ETDEWEB)

    Ihalainen, M. [Suomen Malmi Oy, Espoo (Finland)

    2005-03-15

    Posiva Oy submitted an application for the Decision in Principle to the Finnish Government in May 1999. A positive decision was made at the end of 2000 by the Government. The Finnish Parliament ratified the Decision in Principle on the final disposal facility for spent nuclear fuel at Olkiluoto, Eurajoki in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, the ONKALO, will be constructed. As a part of the investigations Suomen Malmi Oy (Smoy) conducted refraction seismic surveys at Olkiluoto site in Eurajoki. The work was ordered by Posiva Oy. The field work was carried out during May and June 2004. On five profiles S70-S74 totally 1002.5 m was surveyed. The purpose of the work was to determine the overburden thickness and to study bedrock properties, e.g. eventual fractured zones. The work consisted of staking, levelling, seismic measurements, interpretation and reporting. Fieldwork and interpretation were concluded by May and June 2004. Previously in 2000 and 2002 Smoy has carried out 33.0 km of seismic surveys in the area. (orig.)

  11. Sampling and characterisation of groundwater colloids in ONKALO at Olkiluoto, Finland, 2011

    Energy Technology Data Exchange (ETDEWEB)

    Takala, M.; Ojala, S.; Jarvinen, E.; Manninen, P. [Ramboll Finland Oy, Espoo (Finland)

    2012-11-15

    The purpose of this study was to estimate the concentration of colloids and composition of the colloid phase on the basis of the water chemistry results of filtered and unfiltered water samples and to compare the results with the previous ones. The water samples were collected from groundwater stations ONK-PVA1 and ONK-PVA3 in October 2011. The colloid concentrations were determined from scanning electron microscopy (SEM) micrographs taken from the filters. The change in the water chemistry due to filtration was also analysed. The decrease of element concentrations due to filtration would possibly reflect the composition of the colloid phase. Because the concentration of the colloids is very low, two parallel water samples were analysed five times with an Inductively Coupled Plasma - Mass Spectrometry (ICP-MS) analyser so that the chemical differences between the filtered and unfiltered water could be evaluated. The colloid concentration in ONK-PVA1, determined by the single particle analysis of SEM micrographs, was 6 {mu}g/l while the colloid concentration in ONK-PVA3 was 7 {mu}g/l. The colloid phase composition could not be reliably determined due to the low colloid concentration. (orig.)

  12. Sampling and characterisation of groundwater colloids in ONKALO at Olkiluoto, Finland, 2013

    Energy Technology Data Exchange (ETDEWEB)

    Luste, S.; Takala, M.; Manninen, P. [Ramboll Finland Oy, Espoo (Finland)

    2014-06-15

    The purpose of this study was to estimate the concentration of groundwater colloids and to compare the results with the previous ones. The water samples were collected from groundwater stations ONK-PVA1, ONK-PVA5 and ONK-PVA10 in August 2013. The colloid concentrations were determined from scanning electron microscopy (SEM) micrographs taken from the filters in which the groundwater was run through. The particle calculations were performed with computer software ImageJ 1.47. In addition, field flow fractionation (FFF) measurements were performed from the unfiltered water samples. The colloid concentration (diameter 0 - 1 μm) determined by the single particle analysis of SEM micrographs in ONK-PVA1 was 300 μg/l while the colloid concentration in ONK-PVA5 was 30 μg/l and ONK-PVA10 40 μg/l. FFF measurements supported the results of single particle analyses with a difference that an extra peak was found from ONK-PVA1 sample. The peak, which showed no evidence in single particle analyses, was suspected to contain humic substances. (orig.)

  13. Results of monitoring at Olkiluoto in 2009. Environment

    Energy Technology Data Exchange (ETDEWEB)

    Haapanen, A. (ed.) (Haapanen Forest Consulting, Vanhakylae (Finland))

    2010-10-15

    This Working Report presents the main results of Posiva Oy's environmental monitoring programme on Olkiluoto Island in 2009. These summary reports have been published since 2005. The environmental monitoring system supervised by Posiva Oy produces input for biosphere modelling for long-term safety purposes as well as for monitoring the state of the environment during the construction (and later operation) of ONKALO underground characterization facility. Part of the monitoring is performed by the company running the nuclear power plants on the island, Teollisuuden Voima Oy (TVO). Monitoring has been carried out for varying periods of time depending on the sector: some monitoring activities performed by TVO originate from the 1970s and the repository-related environmental monitoring of Olkiluoto from the early 2000s. The monitoring programme evolves according to the experiences gained from the modelling work and an increased understanding of the site. Augmentations in 2009 include e.g. establishment of a new forest intensive monitoring plot (FIP14), continuation of studies on fine roots and on the species composition and abundances of small mammals. Line transect samplings of ants, terrestrial snails and earthworms were carried out and a systematic monitoring of island birds was started. In addition, a project was started where the sediment load and factors affecting the sediment transportation into Eurajoensalmi bay is examined. Dust produced during construction of the third nuclear power unit (OL3), ONKALO and related infrastructure can be seen in the soil solution and deposition results. Furthermore, the construction works and road traffic have a raising effect on the noise levels of the immediate surroundings. The land-use continues to change, but the remaining natural environment resembles other coastal locations. The young age of the soils and the closeness of the sea are reflected in the soil properties. Mammalian fauna on the island is typical of coastal

  14. ONKALO rock mechanics model (RMM) - Version 2.0

    Energy Technology Data Exchange (ETDEWEB)

    Moenkkoenen, H. [WSP Finland Oy, Helsinki (Finland); Hakala, M. [KMS Hakala Oy, Nokia (Finland); Paananen, M.; Laine, E. [Geological Survey of Finland, Espoo (Finland)

    2012-02-15

    The Rock Mechanics Model of the ONKALO rock volume is a description of the significant features and parameters related to rock mechanics. The main objective is to develop a tool to predict the rock properties, quality and hence the potential for stress failure which can then be used for continuing design of the ONKALO and the repository. This is the second implementation of the Rock Mechanics Model and it includes sub-models of the intact rock strength, in situ stress, thermal properties, rock mass quality and properties of the brittle deformation zones. Because of the varying quantities of available data for the different parameters, the types of presentations also vary: some data sets can be presented in the style of a 3D block model but, in other cases, a single distribution represents the whole rock volume hosting the ONKALO. (orig.)

  15. Site scale groundwater flow in Olkiluoto

    Energy Technology Data Exchange (ETDEWEB)

    Loefman, J. [VTT Energy, Espoo (Finland)

    1999-03-01

    Groundwater flow modelling on the site scale has been an essential part of site investigation work carried out at different locations since 1986. The objective of the modelling has been to provide results that characterise the groundwater flow conditions deep in the bedrock. The main result quantities can be used for evaluation of the investigation sites and of the preconditions for safe final disposal of spent nuclear fuel. This study represents the latest modelling effort at Olkiluoto (Finland), and it comprises the transient flow analysis taking into account the effects of density variations and the repository as well as the post-glacial land uplift. The analysis is performed by means of numerical finite element simulation of coupled and transient groundwater flow and solute transport carried out up to 10000 years into the future. This work provides also the results for the site-specific data needs for the block scale groundwater flow modelling at Olkiluoto. Conceptually the fractured bedrock is divided into hydraulic units: the planar fracture zones and the remaining part of the bedrock. The equivalent-continuum (EC) model is applied so that each hydraulic unit is treated as a homogeneous and isotropic continuum with representative average characteristics. All the fracture zones are modelled explicitly and represented by two-dimensional finite elements. A site-specific simulation model for groundwater flow and solute transport is developed on the basis of the latest hydrogeological and hydrogeochemical field investigations at Olkiluoto. The present groundwater table and topography together with a mathematical model describing the land uplift at the Olkiluoto area are employed as a boundary condition at the surface of the model. The overall flow pattern is mostly controlled by the local variations in the topography. Below the island of Olkiluoto the flow direction is mostly downwards, while near the shoreline and below the sea water flows horizontally and

  16. Results of monitoring at Olkiluoto in 2010. Hydrology

    Energy Technology Data Exchange (ETDEWEB)

    Vaittinen, T.; Ahokas, H.; Klockars, J.; Nummela, J.; Pentti, E.; Penttinen, T.; Poellaenen, J. [Poeyry Finland Oy, Espoo (Finland); Karvonen, T. [WaterHope, Helsinki (Finland); Lindgren, S.

    2012-03-15

    The impact of the construction of ONKALO is monitored by measuring and observing numerous different parameters related to hydrology, geochemistry, environment, rock mechanics and foreign materials. The Hydrological Monitoring Programme consists of the following parameters: groundwater level, hydraulic head, flow conditions in open boreholes, cross drillhole flow, hydraulic conductivity, groundwater salinity (in situ EC), precipitation (including snow), sea-water level, surface flow (runoff), infiltration, ground frost, leakages in tunnels, and water balance in the tunnel system and in Korvensuo Reservoir. This Report focuses on hydrogeological parameters. Other parameters, like precipitation, ground frost etc. will be reported in the Monitoring Report of Environment. Monitoring has primarily been carried out according to plan. This Report presents the results for the year 2010. A significant change took place in the Monitoring Programme when most of the open drillholes were packed-off before the excavation of the ONKALO access tunnel through the hydrogeological HZ20 zones began in June 2008. Prior to packing-off, open drillholes connected the main hydrogeological features, the HZ19 and HZ20 systems, to each other. Due to the packing-off of open drillholes, the number of flow logging and hydraulic testing (HTU) measurements has decreased considerably. The mapping of water leakages and moisture conditions in tunnel walls and roof has been continued. Some changes have been observed in the pattern of moisture content. The changes have probably been caused by shotcreting, postgrouting and possibly also by seasonal effects. The changes have so far not been analysed. The changes observed in the groundwater level in shallow observation tubes in the overburden and in shallow drillholes in the bedrock are not necessarily caused by the construction of ONKALO. However, weak indications of a decrease in groundwater level have been observed. Effects on the head deeper in the

  17. Characterization of the excavation disturbance caused by boring of the experimental full scale deposition holes in the Research Tunnel of Olkiluoto

    Energy Technology Data Exchange (ETDEWEB)

    Autio, J. [Saanio and Riekkola Oy, Helsinki (Finland)

    1997-09-01

    Three holes, the size of deposition holes, were bored in the Research Tunnel using a novel full-face boring technique. During the boring test, procedures were carried out in order to determine the effect of changes in operating parameters on the performance of the boring machine and the quality of the hole. Evaluation of the quality of the hole included studies of the geometry of the holes, measurements of surface roughness using a laser profilometer, rock mechanical determinations and study of excavation disturbances in the zone adjacent to the surface of the holes using two novel methods, the He-gas method and the {sup 14}C-polymethylmethacrylate ({sup 14}C-PMMA) method. It was found that there is a distinct disturbed zone adjacent to the surface of the full scale deposition holes which can be divided into three different zones. The zones are as follows: a crushed zone penetrating to a depth of about 3 mm from the surface, a fractured zone extending to a depth of 6 - 10 mm from the crushed zone and a micro fractured zone extending to a depth of 15 - 31 mm from the fractured zone. The porosity of the rock in the disturbed zone measured using the {sup 14}C-PMMA method was clearly greater than the porosity of undisturbed rock to a depth of about 11 mm. The values of permeability and effective diffusion coefficient in the disturbed zone measured in a direction perpendicular to the disturbed surface were found to be approximately one order of magnitude larger than those of undisturbed rock. The degree of disturbance was found to be greater where higher levels of thrust had been employed during the boring process. The results obtained also suggest that the disturbance caused by using 4- and 5-row cutters in the cutter head is more pronounced than the disturbance caused when using 5- and 6-row cutters 31 refs, 118 figs, 15 tabs

  18. Disposal of spent fuel in Olkiluoto bedrock. Programme for research, development and technical design for the pre-construction phase

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-12-01

    assessment will be the cornerstone of the long-term safety case, but the argumentation for safety will also be based on broader technical and scientific evidence. A substantial part of the programme activities will be staged according to the progress of the planned underground rock characterisation facility, ONKALO, at Olkiluoto. The plan is to start the construction of ONKALO in 2003-2004. Before that Posiva will complete the documentation concerning the: baseline description of the Olkiluoto site; technical design description of the planned underground rock characterisation facility; plan for underground investigations and review of the rock characteristics that are important for the long-term safety of disposal together with an assessment of how the ONKALO project would affect these. Later, at the end of 2005, Posiva will publish an interim progress report of the disposal programme. The report will also contain a more detailed description of the activities planned for the latter half of the programme period. (orig.)

  19. GPS operations at Olkiluoto in 2009

    Energy Technology Data Exchange (ETDEWEB)

    Kallio, U.; Nyberg, S.; Koivula, H.; Jokela, J.; Poutanen, M.; Ahola, J. (Finnish Geodetic Institute, Masala (Finland))

    2010-06-15

    The GPS based deformation studies have been made at the investigation areas of Posiva since 1995, when the network of ten GPS pillars was established at Olkiluoto. One pillar in the investigation area belongs to the Finnish permanent GPS network, FinnRef. 28 GPS measurement campaigns have been carried out at Olkiluoto since 1995. According to the time series of the GPS results 1/3 of the baselines at Olkiluoto have statistically significant change rates. However, the observed movements are smaller than +-0.20 mm/a. There are five pillars, which have statistically significant horizontal velocities at Olkiluoto. These local velocity components are small but taking into account the standard deviations the largest velocity components seems to be reliably determined. At Olkiluoto a baseline for electronic distance measurements (EDM) was built in 2002. The baseline has been measured using EDM instruments in connection to the GPS observations. Changes in he difference between the GPS and EDM results indicate the systematic change in GPS results. No corrections based on only one baseline were not applied to GPS vectors. The GPS network at Olkiluoto was extended in 2003. The new pillars were built close to Kuivalahti village and on a small island of Iso Pyrekari. According to the geological evidence it is expected that a fracture zone is located between the new stations, thus enabling the determination of possible deformations along the fracture zone. The new pillars have been observed since 2003 and now we have computed the first deformation analysis from the six years data. Four new permanent stations will be established in summer 2010 at Olkiluoto. We have automated the processing of the campaign data by using the Bernese processing engine (BPE) together with our own Perl scripts. The local crustal deformations have been studied in GeoSatakunta project, too. This GPS network is located in Cities of Pori and Rauma and their neighbouring municipalities. Two new pillars

  20. EDZ09 project and related EDZ studies in ONKALO 2008-2010

    Energy Technology Data Exchange (ETDEWEB)

    Mellanen, S. [Genpro Solutions Oy, Helsinki (Finland); Lehtimaeki, T. [Svensk Kaernbraenslehantering AB, Stockholm (Sweden); Heikkinen, E. [Poeyry Finland Oy, Espoo (Finland) Water and Environment; Mustonen, S.; Norokallio, J.

    2010-12-15

    The EDZ (Excavation Damaged Zone) is one of the issues in the evaluation of the long term safety concerning the underground rock surfaces of the final disposal facility. There have been various research and development tasks relating to the EDZ (among other items the EDZ300 Project) completed both before starting the excavation of the ONKALO underground facility and during the construction work. The EDZ09 Project was established to improve the drill and blast excavation method to control the EDZ and to verify the feasibility of Ground Penetrating Radar as a characterisation tool for the EDZ. The project was divided into two parts: Work Package (WP1), which managed the control of the excavation; and Work Package 2 (WP2), which concentrated on the geophysical tests. Long term safety issues were not included into EDZ09 Project. The project work was undertaken in a specific EDZ niche (Tutkimustila 3, ONK-TKU- 3620) with Work Package 1 being concerned with the research niche excavation and Work Package 2 with activities conducted in the niche. In Work Package 2 (WP2), a series of investigations under controlled conditions for EDZ assessment was conducted before and after the excavation. These measurements were performed in drillholes and on the tunnel surface. The investigations carried out before excavation of the EDZ-tunnel define the undisturbed, baseline conditions in the surrounding rock (behind the planned tunnel wall); and the investigations carried out after excavation of EDZ-tunnel define the conditions when the EDZ already exists. The induced change in the conditions before and after excavation indicate the EDZ. The results of measurements from tunnel surfaces and from drillholes were reviewed with petrophysical sample data taken and analysed from the same location. Baseline investigations included: (1) a reflection seismic single-hole survey in a drillhole parallel to the planned tunnel outside the tunnel contour; (2) seismic tomography between two drillholes

  1. ONKALO POSE experiment. Phase 3: execution and monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Valli, J. [Poeyry Finland Oy, Vantaa (Finland); Hakala, M. [KMS-Hakala Oy, Nokia (Finland); Wanne, T. [Saanio and Riekkola Oy, Helsinki (Finland); Kantia, P. [Geofcon Oy, Rovaniemi (Finland); Siren, T.

    2014-01-15

    In-depth knowledge of the in situ stress state at the Olkiluoto site is critical for stability assessment both prior to and after deposition of spent nuclear fuel in order to understand and avoid potential damage to the rock at the site. Posiva's Olkiluoto Spalling Experiment (POSE) was designed specifically for this purpose with three primary goals: establish the in situ spalling/damage strength of Olkiluoto migmatitic gneiss, establish the state of in situ stress at the -345 m depth level and act as a Prediction-Outcome (P-O) exercise. Phases 1 and 2 of POSE are outlined in WR 2012-60. The objectives of the third phase of the POSE experiment are the same as the original objectives outlined above. This report outlines the execution and results of the third phase of the POSE experiment. The third phase of the experiment involved internally heating the third experimental hole (ONK-EH3) of the POSE niche in order to cause a symmetrical thermal stress increase around the hole due to the thermal expansion of rock. This thermomechanically induced stress increase, coupled with the estimated existing in situ stress state, should cause the maximum principal stress around the hole to exceed the predicted spalling strength of the rock around the hole. ONK-EH3 is located almost completely in pegmatitic granite. Four fractures near the top of the hole were mapped after boring ONK-EH3, and a tensile failure located at the contact between mica-rich gneiss and pegmatitic granite was observed 18 months after boring, prior to the experiment. Based on predictive calculations and the estimated in situ state of stress, the maximum principal stress magnitude should reach ca. 100 MPa when the temperature was just below 100 deg C after 12 weeks of heating. There were problems with the heater control unit at the beginning of the experiment, after which heating proceeded according to plan. The crack damage threshold of pegmatitic granite has been determined to be 85 ±17 MPa at

  2. Core drilling of deep borehole OL-KR43 at Olkiluoto in Eurajoki 2006

    Energy Technology Data Exchange (ETDEWEB)

    Niinimaeki, R. [Suomen Malmi Oy, Espoo (Finland)

    2006-12-15

    Posiva Oy submitted an application to the Finnish Government in May 1999 for the Decision in Principle to choose Olkiluoto in the municipality of Eurajoki as the site of the final disposal facility for spent nuclear fuel. A positive decision was made at the end of 2000 by the Government. The Finnish Parliament ratified the decision in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, ONKALO, will be constructed. As a part of the investigations Suomen Malmi Oy (Smoy) core drilled 1000.26 m and 45.01 m deep boreholes with a diameter of 75.7 mm at Olkiluoto in July - October 2006. The identification numbers of the boreholes are OL-KR43 and OL-KR43B, respectively. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the drilling water and the returning water were recorded. The drill rig was computer controlled and during drilling the computer recorded drilling parameters. The objective of all these measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The total volumes of the used drilling and flushing water were 1103 m{sup 3} and 16 m{sup 3} in boreholes OL-KR43 and OL-KR43B, respectively. Measured volumes of the returning water were 916m{sup 3} in borehole OL-KR43 and 13m{sup 3} in borehole OL-KR43B. The deviation of the boreholes was measured with the deviation measuring instruments EMS and Maxibor. Uniaxial compressive strength, Young's Modulus and Poisson's ratio were measured from the core samples. The average uniaxial compressive strength is about 131 MPa, the average Young's Modulus is 37 GPa and the average Poisson's ratio is 0.19. The main rock types are veined gneiss, diatexitic gneiss

  3. Core drilling of deep borehole OL-KR3B at Olkiluoto in Eurajoki 2005

    Energy Technology Data Exchange (ETDEWEB)

    Rautio, T. [Suomen Malmi Oy, Espoo (Finland)

    2005-10-15

    Posiva Oy submitted an application for the Decision in Principle to the Finnish Government in May 1999. A positive decision was made at the end of 2000 by the Government. The Finnish Parliament ratified the Decision in Principle on the final disposal facility for spent nuclear fuel at Olkiluoto, Eurajoki in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, ONKALO, will be constructed. As a part of the investigations Suomen Malmi Oy (Smoy) core drilled 530.60 m deep borehole with a diameter of 75.7 mm at Olkiluoto in summer 2005. This borehole was aimed to get additional information of the quality of bedrock in the area, where a new shaft with a diameter of 3 m is planned to be located. The identification number of the borehole is OL-KR38. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the drilling water and the returning water were recorded. The drill rig was computer controlled and during drilling the computer recorded information about drilling parameters. The objective of these measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The volume of the used drilling water was about 473m{sup 3} and the measured volume of the returning water was about 38m{sup 3} in borehole OL-KR38. The deviation of the borehole was measured with the deviation measuring instruments EMS and Devitool Peewee. The results of the EMS measurements indicate that borehole OL-KR38 deviates 1.02 m south and 0.58 m west from the target point at the borehole depth of 525 m. Uniaxial compressive strength, Young's Modulus and Poisson's ratio were measured from the core samples. The average uniaxial compressive strength is about 106

  4. Core drilling of deep borehole OL-KR37 at Olkiluoto in Eurajoki 2005

    Energy Technology Data Exchange (ETDEWEB)

    Niinimaeki, R. [Suomen Malmi Oy, Espoo (Finland)

    2005-11-15

    Posiva Oy submitted an application to the Finnish Government in May 1999 for the Decision in Principle to choose Olkiluoto in the municipality of Eurajoki as the site of the final disposal facility for spent nuclear fuel. A positive decision was made at the end of 2000 by the Government. The Finnish Parliament ratified the decision in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, ONKALO, will be constructed. As a part of the investigations Suomen Malmi Oy (Smoy) core drilled 350.00 m and 45.10 m deep boreholes with a diameter of 75.7 mm at Olkiluoto in June- August 2005. The identification numbers of the boreholes are OL-KR37 and OL-KR37B, respectively. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the drilling water and the returning water were recorded. The drill rig was computer controlled and during drilling the computer recorded information about drilling parameters. The objective of all these measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The total volumes of the used drilling and flushing water were 273 m{sup 3} and 21m{sup 3} and the measured volumes of the returning water were 221m{sup 3} and 16m{sup 3} in boreholes OL-KR37 and OL-KR37B, respectively. The deviation of the borehole was measured with the deviation measuring instruments EMS and Maxibor. Uniaxial compressive strength, Young's Modulus and Poisson' s ratio were measured from the core samples. The average uniaxial compressive strength is about 106 MPa, the average Young's modulus is 40 GPa and the average Poisson's ratio is 0.20. The main rock types are migmatitic mica gneiss, granite and tonalite. Filled

  5. Core drilling of deep borehole OL-KR39 at Olkiluoto in Eurajoki 2005

    Energy Technology Data Exchange (ETDEWEB)

    Niinimaeki, R. [Suomen Malmi Oy, Espoo (Finland)

    2005-11-15

    Posiva Oy submitted an application to the Finnish Government in May 1999 for the Decision in Principle to choose Olkiluoto in the municipality of Eurajoki as the site of the final disposal facility for spent nuclear fuel. A positive decision was made at the end of 2000 by the Government. The Finnish Parliament ratified the decision in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, ONKALO, will be constructed. As a part of the investigations Suomen Malmi Oy (Smoy) core drilled 502.97 m and 45.11 m deep boreholes with a diameter of 75.7 mm at Olkiluoto in August- October 2005. The identification numbers of the boreholes are OL-KR39 and OL-KR39B, respectively. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the drilling water and the returning water were recorded. The drill rig was computer controlled and during drilling the computer recorded drilling parameters. The objective of all these measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The total volumes of the used drilling and flushing water were 415m{sup 3} and 25 m{sup 3} and the measured volumes of the returning water were 175 m{sup 3} and 7 m{sup 3} in boreholes OLKR39 and OL-KR39B, respectively. The deviation of the borehole was measured with the deviation measuring instruments EMS and Maxibor. Uniaxial compressive strength, Young's Modulus and Poisson' s ratio were measured from the core samples. The average uniaxial compressive strength is about 110 MPa, the average Young's Modulus is 49 GP a and the average Poisson' s ratio is 0.25. The main rock types are migmatitic mica gneiss and granite. Filled fracture is the most common

  6. Core drilling of deep borehole OL-KR36 at Olkiluoto in Eurajoki 2005

    Energy Technology Data Exchange (ETDEWEB)

    Niinimaeki, R.; Rautio, T. [Suomen Malmi Oy, Espoo (Finland)

    2005-07-15

    Posiva Oy submitted an application for the Decision in Principle to the Finnish Government in May 1999. A positive decision was made at the end of 2000 by the Government. The Finnish Parliament ratified the Decision in Principle on the final disposal facility for spent nuclear fuel at Olkiluoto, Eurajoki in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, ONKALO, will be constructed. As a part of the investigations Suomen Malmi Oy (Smoy) core drilled 205.17 m deep borehole with a diameter of 75.7 mm at Olkiluoto in May 2005. This borehole was aimed to get additional information of the quality of bedrock and the anomalous part of the bedrock and quality and the location of the fractured zones R19A and R19B. The identification number of the borehole is OL-KR36. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the drilling water and the returning water were recorded. The drill rig was computer controlled and during drilling the computer recorded information about drilling measurements. The objective of all these measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The volume of the used drilling water was about 117 m{sup 3} and the measured volume of the returning water was about 51m{sup 3} in borehole OL-KR36. The deviation of the borehole was measured with the deviation measuring instruments EMS and Maxibor. The results of the Maxibor measurements indicate that borehole OL-KR36 deviates 10.34 m left and 7.11 m up at the borehole depth of 204 m. Uniaxial compressive strength, Young's Modulus and Poisson' s ratio were measured from the core samples. The average uniaxial compressive strength is about 126

  7. Core drilling of deep borehole OL-KR34 at Olkiluoto in Eurajoki 2005

    Energy Technology Data Exchange (ETDEWEB)

    Rautio, T. [Suomen Malmi Oy, Espoo (Finland)

    2005-07-15

    Posiva Oy submitted an application for the Decision in Principle to the Finnish Government in May 1999. A positive decision was made at the end of 2000 by the Government. The Finnish Parliament ratified the Decision in Principle on the final disposal facility for spent nuclear fuel at Olkiluoto, Eurajoki in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, ONKALO, will be constructed. As a part of the investigations Suomen Malmi Oy (Smoy) core drilled 100.07 m deep borehole with a diameter of 75.7 mm at Olkiluoto in April 2005. This borehole was aimed to get additional information of the quality of bedrock and the anomalous part of the bedrock and quality and the location of the fractured zones R19A and R19B. The identification number of the borehole is OL-KR34. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the drilling water and the returning water were recorded. The drill rig was computer controlled and during drilling the computer recorded information about drilling parameters. The objective of all measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The volume of the used drilling water was about 37m{sup 3} and the measured volume of the returning water was about 18m{sup 3} in borehole OL-KR34. The deviation of the borehole was measured with the deviation measuring instruments EMS and Maxibor. The results of the Maxibor measurements indicate that borehole OLKR34 deviates 0.84 m right and 0.15 m up at the borehole depth of 99 m. Uniaxial compressive strength, Young's Modulus and Poisson' s ratio were measured from the core samples. The average uniaxial compressive strength is about 142 MPa, the

  8. Core drilling of deep borehole OL-KR35 at Olkiluoto in Eurajoki 2005

    Energy Technology Data Exchange (ETDEWEB)

    Rautio, T. [Suomen Malmi Oy, Espoo (Finland)

    2005-07-15

    Posiva Oy submitted an application for the Decision in Principle to the Finnish Government in May 1999. A positive decision was made at the end of 2000 by the Government. The Finnish Parliament ratified the Decision in Principle on the final disposal facility for spent nuclear fuel at Olkiluoto, Eurajoki in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, ONKALO, will be constructed. As a part of the investigations Suomen Malmi Oy (Smoy) core drilled 100.87 m deep borehole with a diameter of 75.7 mm at Olkiluoto in May 2005. This borehole was aimed to get additional information of the quality of bedrock and the anomalous part of the bedrock and quality and the location of the fractured zones R19A and R19B. The identification number of the borehole is OL-KR35. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the drilling water and the returning water were recorded. The drill rig was computer controlled and during drilling the computer recorded information about drilling parameters. The objective of all measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The volume of the used drilling water was about 53 m{sup 3} and the measured volume of the returning water was about 25 m{sup 3} in borehole OL-KR35. The deviation of the borehole was measured with the deviation measuring instruments EMS and Maxibor. The results of the Maxibor measurements indicate that borehole OL-KR35 deviates 0.49 m right and 0.30 m up at the borehole depth of 99 m. Uniaxial compressive strength, Young's Modulus and Poisson' s ratio were measured from the core samples. The average uniaxial compressive strength is about 90 MPa, the

  9. Ecosystem characterization strategy at a repository site - Olkiluoto as a case study

    Energy Technology Data Exchange (ETDEWEB)

    Pere, Tuomas [Posiva Oy, Olkiluoto, 27160 Eurajoki (Finland); Kangasniemi, Ville [Environmental Research and Assessment EnviroCase, Ltd., Hallituskatu 1 D 4, 28100 Pori (Finland); Lahdenperae, Anne-Maj [Saanio and Riekkola Oy, Laulukuja 4, 00420 Helsinki (Finland); Aro, Lasse [Finnish Forest Research Institute, Kaironiementie 15, 39700 Parkano (Finland)

    2014-07-01

    Posiva Oy is constructing an underground research facility ONKALO in Olkiluoto, located in the municipality of Eurajoki, Finland. This is part of the plan for final disposal of spent nuclear fuel produced by Posiva's owners: Teollisuuden Voima Oyj and Fortum Power and Heat Oyj. Posiva has applied for construction license for an underground repository, which is planned to start its operation around the year 2020. The final disposal of high-level radioactive waste poses questions of long-term safety and possible processes of radionuclide release in the EBS (Engineered Barrier System) and the geosphere are also modelled as well as possible transport routes in the bedrock. Posiva has also established a monitoring program for the environment and is also conducting modelling of the surface environment and biosphere in Olkiluoto and the surrounding reference area. These serve the purpose of both, site description and modelling of the transport and accumulation of possible radionuclide releases in the surface environment and biosphere. The process of modelling used by Posiva requires the division of the surface environment and biosphere into several categories. In Posiva's classification, ecosystems are divided to two categories: terrestrial and aquatic with terrestrial divided to forests and agricultural areas. These categories are further divided to ecosystem types which include: lake, river, forest, cropland and sea (with coastal sea as a separate type). These types are even further divided to 14 ecosystem sub-types and behind these sub-types, a total of 24 biotopes exist. Soil and sediment types are also classified to 7 classes. The methodology behind the selection of these biotopes and their connection to the modelling of radionuclide transport in the surface environment is further described in the text. Some of the ecosystem types and biotopes are absent in present-day Olkiluoto area, which necessitates the use of reference targets, such as lakes, rivers

  10. Fracture toughness properties of rocks in Olkiluoto: Laboratory measurements 2008-2009

    Energy Technology Data Exchange (ETDEWEB)

    Siren, T.

    2012-05-15

    In Olkiluoto an underground rock characterization facility (ONKALO) for the final disposal site of spent nuclear fuel has been under thorough research many years, but further knowledge is needed on fracture toughness parameters. Fracture toughness parameters are important for example in fracture mechanics prediction for Posiva's Olkiluoto Spalling Experiment (POSE). This working report describes a laboratory campaign that was done between 2008 and 2009. The campaign aimed at determining the fracture mechanics parameters as well as density and ultrasonic velocities for Olkiluoto rocks. The specimens delivered were selected by Posiva; the core showed no damage and the quality of the delivered cores was good with varying sample diameter. Most of the test samples (9 out of 12) are gneissic rock. The Mode I fracture toughness was determined using two different methods to account for two different fracturing directions. The methods are the Chevron Bend (CB) test as proposed in the ISRM Suggested Method and a method based on the Brazilian Disk (BD) experiment. The Mode II fracture toughness was determined using the Punch-Through Shear with Confining Pressure experiment on the remaining pieces from the CB testing. The scatter in the results is very large, even within one piece of core sample. Usually the scatter of results is less than 5 %. The high scatter in the data at hand is believed to be due to the very inhomogeneous nature of the rock material. The magnitude of the determined Mode I fracture toughness compares well with available reported data for medium to coarse grained granitoide rocks. However the scatter of the mode II fracture toughness values is higher than experienced on other rock types, but the variability is reasonable for the inhomogeneous rock type. Distinguishing the fracture toughness values for different anisotropy directions would require more thorough testing with quality samples at different anisotropy directions. However since fracture

  11. Rock mechanics stability at Olkiluoto, Haestholmen, Kivetty and Romuvaara

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, E.; Rautakorpi, J. [Saanio and Riekkola Oy, Helsinki (Finland)

    2000-02-01

    Posiva Oy is studying the suitability of the Finnish bedrock for the geological disposal of spent nuclear fuel at four sites, Olkiluoto in Eurajoki, Haestholmen in Loviisa, Kivetty in Aeaenekoski and Romuvaara in Kuhmo. To enable the rock properties to be specified in great detail, the site-selection research programme has included rock mechanics investigations such as the measurement of in-situ rock stress and laboratory tests on rock samples. This report presents the results of the rock mechanics analyses performed on the main rock types at the Olkiluoto, Romuvaara, Kivetty and Haestholmen sites. The objective of this study was to assess the near-field stability of the final disposal tunnels and deposition holes at each of the investigation sites. Two empirical methods and a numerical method based on three-dimensional element code (3DEC) were used the analysis tools. A statistical approach was used to select the necessary input data and to specify the cases being analysed. The stability of the KBS-3 and MLH (Medium Long Hole) repository concepts during the pre-closure and post-closure phases was analysed. The repository depths investigated lay between 300 m and 700 m. The empirical methods are based on the study of the ratios between rock strength and the in-situ stress which could result in possible fracturing of the rock mass. Interpretation of the numerical analyses is based on the assumption of an elastic distribution of stress around the disposal tunnel and the deposition hole and the brittle rock strength criterion. The results obtained in this study indicate that in general, the rock mechanics conditions during the pre-closure and post-closure phases at each of the investigated sites remain good and stable between the studied depth levels, especially when the deposition rooms are oriented in a direction parallel to the major in-situ stress. If the disposal tunnels are orientated in a direction perpendicular to the major in-situ stress, the resultant

  12. Evolution of the Olkiluoto site. Palaeohydrogeochemical considerations

    Energy Technology Data Exchange (ETDEWEB)

    Smellie, J. (ed.) [Conterra AB, Stockholm (Sweden); Pitkaenen, P.; Koskinen, L.; and others

    2014-05-15

    Over the past 20 years a considerable amount of work has been carried out to establish a palaeohydrogeological understanding of the Olkiluoto site and surrounding area, and to integrate this knowledge into the hydrogeochemical and hydrogeological descriptive and modelling programmes. This has involved not only a wide range of well established disciplines such as geology, hydrogeology and hydrochemistry, but also the extraction and determination of rock matrix porewaters by out-diffusion, a relatively new approach in crystalline rock. This required a sophisticated laboratory based input, not only to extract and analyse the porewaters, but also to take into consideration any effects associated to, for example, connected physical porosity and/or geochemical porosity in the rock matrix. In general, there is a good integrated understanding of the Olkiluoto site in terms of the geology, mineralogy, hydrology, hydrochemistry and the overall palaeohydrogeochemical model. The Olkiluoto site has had a complex geological and environmental history from Precambrian to the Quaternary as shown by fluid inclusions in quartz grains and fracture calcites. The Quaternary time period has been dominated by a large climatic variation of cold glacial cycles with temperate interglacials and sea-level changes, all of which have contributed to the hydrogeochemical evolution at the Olkiluoto site. All data indicate that infiltration of aerobic water has systematically been limited to few metres depth in the bedrock at Olkiluoto. Today at about the -300 m elevation level, there exists a distinct change in groundwater chemistry and mean residence time including a redox divide supported by a significant reduction in both the intensity and transmissivity of the water connected fracture networks. These indicate that long term stability (over the time span of glacial cycles) and sufficient buffering capacity of the water-rock system against aerobic infiltration, has dominated continuously until

  13. Core Drilling of shallow drillholes OL-PP72...OL-PP89 at Olkiluoto, Eurajoki 2011

    Energy Technology Data Exchange (ETDEWEB)

    Toropainen, V. [Suomen Malmi Oy, Espoo (Finland)

    2012-05-15

    Suomen Malmi Oy (Smoy) core drilled eighteen drillholes to survey the ground and bedrock conditions in the encapsulation plant building site at Olkiluoto, Eurajoki 2011. Soil quality, bedrock depth and quality of near surface bedrock were investigated in this project. The drillholes were drilled between 19th of October and 8th of November 2011. The lengths of the drillholes are mostly between 7 to 9 metres, except for the drillhole OL-PP79, which is 15 metres by length. The drillholes are 76 mm by diameter, and the core diameter is 60.2 mm. The lightweight GM75 drilling rig with rubber tracks was used. The drilling water was taken from the ONKALO area research building freshwater pipeline and sodium fluorescein was added as a label agent in the drilling water. The drillholes were not left open. In addition to drilling the drillcores were logged and reported by geologist. Geological logging included the following parameters: lithology, foliation, fracture parameters, fractured zones, core loss, weathering, fracture frequency, RQD and rock quality. The average natural fracture frequencies of the drillcores range from 2.5 pc/m (OL-PP77) to 11.8 pc/m (OL-PP86). The average RQD ranges from 55.1 % (OL-PP86) to 96.4 % (OL-PP77). The penetrated soils are mostly ground fill (blast rock), but some clays and sands are lying below the fill layer. (orig.)

  14. ONKALO POSE experiment. Phase 3: acoustic and ultrasonic monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Reyes-Montes, J.; Flynn, W.; Huang, J. [Applied Seismology Consultants, Shrewsbury (United Kingdom)

    2014-01-15

    The objectives of the third phase of the POSE experiment are to determine the in situ state of stress at Olkiluoto and the spalling strength of Olkiluoto rock, by internal heating of the experimental hole (ONK-EH3) using 8 vertically installed heaters. This report presents the results from the Acoustic and ultrasonic monitoring carried out around the third experimental hole of the POSE niche between November 2012 and May 2013. The experiment was monitored using an array of 24 transducers installed along 4 monitoring drillholes and data was automatically acquired and processed using the system installed at the niche by Applied Seismology Consultants in May 2012. Daily ultrasonic surveys were carried out between 14{sup th} November 2012 and 21{sup st} May 2013, monitoring the changes in transmission velocities of P and S-waves with an estimated error of ±2 m x s{sup -1} (ASC, 2013). Changes in transmission velocities closely follow the evolution of the temperature profile in the hole wall. An increase in both P-and S-wave transmission velocities is observed at all depth levels and surveyed raypaths during the heating phase, with the highest changes observed in raypaths skimming the hole surface and depths between 2.33 m and 3.7 m. This observation indicates the closure of in situ and excavation-induced microcracks due to thermal stress. After the heaters were switched off, P-wave velocities show a marked decrease, in all raypaths reaching values below those measured at the start of the monitoring approximately 4 weeks after the heaters were switched off. The highest decrease was observed along raypaths surveying the region skimming the hole wall. This decrease below original background values indicates the induction of rock degradation as microcracking induced through the heating-cooling cycle. Changes in P- and S-wave transmission velocity were used to calculate changes in Young's modulus and Poisson's ratio along the different raypaths and depth levels

  15. Simulations of permafrost evolution at Olkiluoto

    Energy Technology Data Exchange (ETDEWEB)

    Hartikainen, J. [Aalto Univ., Espoo (Finland)

    2013-07-15

    This report provides numerical estimations of the evolution of permafrost and perennially frozen ground at Olkiluoto on time-scales of 60,000 and 125,000 years using Olkiluoto's site-specific information on time histories of ground level temperatures, ice sheet thickness, basal conditions, shoreline migration, soil and vegetation cover as well as heat generation from the spent fuel at a depth of 420 metres. When considering environmental conditions akin to the last glacial cycle for a 125,000 years long period, the maximum permafrost depth over the repository area can exceed the depth of 300 m and the maximum depth of perennially frozen ground the depth of 270 m. If Olkiluoto, after a 50,000 years long temperate phase of boreal climate, was subjected to a 10,000 years long periglacial period with air temperature decreased between -5 deg C and -10 deg C, the maximum permafrost depth would range between 60 and 240 m and the maximum depth of perennially frozen ground between 50 and 220 m. Furthermore, permafrost would reach the repository depth in 10,000 years, if the air temperature was lowered down to -15 deg C and the ground surface had a very thin vegetation and snow cover. Alternatively, if Olkiluoto experienced a 125,000 years long glacial cycle with a very long periglacial periods of low air temperatures and thin vegetation and snow cover and without any ice sheet development, permafrost would reach the depth of 400 m in 98,000 years and perennially frozen ground in 101,000 years. The areal distribution of permafrost and perennially frozen ground are broadly affected by the snow cover, lakes and the peat areas, especially when an extensive peat growth occurs. The lack of snow cover can enhance the evolution of the maximum depth of permafrost and perennially frozen ground by over 50 %. In addition, ground thermal conditions and the heat generation from the spent fuel modify the spatial and temporal development of permafrost and perennially frozen ground. A

  16. GPS operations at Olkiluoto, Kivetty and Romuvaara in 2010

    Energy Technology Data Exchange (ETDEWEB)

    Kallio, U.; Nyberg, S.; Koivula, H.; Jokela, J.; Poutanen, M. [Finnish Geodetic Institute, Masala (Finland)

    2011-11-15

    The Finnish Geodetic Institute (FGI) has studied crustal deformations in co-operation with the Posiva Oy since 1994, when a network of ten pillars for GPS observations was established at Olkiluoto. In 2010 the local GPS network at Olkiluoto consisted of 14 concrete pillars. The whole network has been measured twice a year in the static GPS campaigns with 24 h sessions. The four new pillars were established in 2010 and the permanent measurements on them will start in 2011. The network of seven GPS pillars was built at Kivetty and Romuvaara during the year 1996. One pillar in each investigation area belongs to the Finnish permanent GPS network, FinnRef. A total of 28 GPS measurement campaigns have been carried out at Olkiluoto since 1995, and 18 campaigns at Kivetty and Romuvaara. At Olkiluoto a baseline for electronic distance measurements (EDM) was built in 2002. The baseline has been measured in connection to the GPS observations using the EDM instrument Kern ME5000 Mekometer. The GPS operations in 2010 included the two GPS campaigns at Olkiluoto, GPS campaigns at Kivetty and Romuvaara, EDM baseline measurements at Olkiluoto, and the control marker measurements with the tachymeter at Olkiluoto. All GPS data history was reprocessed with Bernese GPS software using the new processing strategy tested in 2009. The results were analysed by computing the change rates of the baselines and estimating horizontal velocities for the pillars using the barycenter of the velocities as a reference. In the Olkiluoto inner network 80 percent of the change rates were smaller than 0.10 mm/a. Roughly one fourth of the change rates could be considered as statistically significant (change rate larger than 3 {sigma}. The statistically significant change rates were mainly related to the Olkiluoto permanent station (GPS1) and to the pillar GPS5, which had also the maximum change rate (0.21 {+-} 0.03 mm/a). In Olkiluoto outer network the maximum and statistically significant change rates

  17. Safety case for the disposal of spent nuclear fuel at Olkiluoto. Description of the disposal system 2012

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-12-15

    Description of the Disposal System sits within Posiva Oy's Safety Case 'TURVA-2012' report portfolio and has the objective presenting the initial state of the disposal system for the safety case for the disposal of spent nuclear fuel at Olkiluoto, Finland. Disposal system is an entity composed of a repository system and surface environment. The repository system includes the spent nuclear fuel, canister, buffer, backfill, and closure components as well as the host rock. The repository system components have assigned safety functions (except for the spent nuclear fuel) and are subject to requirements. The initial state is presented for each component, and references to the main supporting reports are given to guide the reader for more details. Conditions for each component vary in time and space, due to the time of emplacement and due to the tolerances set for the compositions, geometries and other properties depending on the component. The disposal operation is foreseen to commence {approx} 2020. At the beginning of the postclosure period, around 2120, all the engineered components have been installed and the operation is finalised. The system evolution during the operational phase is discussed in detail in Performance Assessment. The initial state for the host rock is defined to be essentially equal to the baseline conditions prior to starting the construction of the underground characterisation facility ONKALO. For the surface environment, the initial state is the present conditions prevailing. For any other component of the disposal system, the initial state is defined as the state it has when the direct control over that specific part of the system ceases and only limited information can be made available on the subsequent development of conditions in that part of the system or its near field. (orig.)

  18. Chemistry and dissolved gases of matrix pore water and fluid inclusions in Olkiluoto bedrock from drillhole ONK-PH9

    Energy Technology Data Exchange (ETDEWEB)

    Eichinger, F.; Haemmerli, J.; Waber, H.N.; Diamond, L.W. [Univ. of Bern (Switzerland). Inst. of Geological Sciences; Smellie, J.A.T. [Conterra AB, Stockholm (Sweden)

    2013-05-15

    Matrix pore water and gas dissolved in matrix pore water in drillcore samples from drillhole ONK-PH9 have been successfully characterised for their chemical and isotopic composition. Based on the comparison of natural tracers in matrix pore water and adjacent fracture groundwater, conclusions about the palaeohydrogeological history of the encountered system are drawn. The investigations are based on naturally saturated core samples from the subhorizontal drillhole ONK-PH9 which was drilled from the ONKALO access tunnel at a vertical depth of 306 m into the bedrock intersecting the water-conducting hydrogeological zone HZ20B. Pore water samples were taken from this highly transmissive water-conducting zone and the adjacent low transmissive bedrock along a continuous eleven metre long profile. Additional samples have been collected at intervals between five and ten metres until 100 m drillhole length (DHL)

  19. Safety case for the disposal of spent nuclear fuel at Olkiluoto. Features, events and processes 2012

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-12-15

    Features, Events and Processes sits within Posiva Oy's Safety Case 'TURVA-2012' portfolio and has the objective of presenting the main features, events and processes (FEPs) that are considered to be potentially significant for the long-term safety of the planned KBS-3V repository for spent nuclear fuel at Olkiluoto. The primary purpose of this report is to support Performance Assessment, Formulation of Radionuclide Release Scenarios, Assessment of the Radionuclide Release Scenarios for the Repository System and Biosphere Assessment by ensuring that the scenarios are comprehensive and take account of all significant FEPs. The main FEPs potentially affecting the disposal system are described for each relevant subsystem component or barrier (i.e. the spent nuclear fuel, the canister, the buffer and tunnel backfill, the auxiliary components, the geosphere and the surface environment). In addition, a small number of external FEPs that may potentially influence the evolution of the disposal system are described. The conceptual understanding and operation of each FEP is described, together with the main features (variables) of the disposal system that may affect its occurrence or significance. Olkiluoto-specific issues are considered when relevant. The main uncertainties (conceptual and parameter/data) associated with each FEP that may affect understanding are also documented. Indicative parameter values are provided, in some cases, to illustrate the magnitude or rate of a process, but it is not the intention of this report to provide the complete set of numerical values that are used in the quantitative safety assessment calculations. Many of the FEPs are interdependent and, therefore, the descriptions also identify the most important direct couplings between the FEPs. This information is used in the formulation of scenarios to ensure the conceptual models and calculational cases are both comprehensive and representative. (orig.)

  20. Analysis results of PAVE sampling of groundwaters from open boreholes OL-KR2, OL-KR7, OL-KR13 and OL-KR15 at Olkiluoto, Eurajoki, in 2004

    Energy Technology Data Exchange (ETDEWEB)

    Hirvonen, H. [Teollisuuden Voima Oyj, Eurajoki (Finland); Hatanpaa, E. [lnsinoeoeritoimisto Paavo Ristola Oy, Hollola (Finland)

    2005-12-15

    Four groundwater samples were collected at Olkiluoto from open boreholes OL-KR2, OL-KR7, OL-KR13 and OL-KR15 with pressurised water sampling equipment (PAVE) between summer 2004 and the beginning of 2005. The aim of the ground water sampling was to get information for the basis of the monitoring program during ONKALO construction. Sampling sections were mainly chosen so that the results of the chemical analyses from earlier studies could be used for comparison. This study is a part of Olkiluoto's monitoring programme (OMO). This study presents the sampling methods and the results of the laboratory analyses of groundwater samples from the open boreholes OL-KR2/328.5-330.5 m, OL-KR7/275.5- 289.5 m, OL-KR13/362-365 m and OL-KR15/241-245 m. The analytical results of the groundwater samplings are compared to earlier analytical results. According to Davis and De Wiest's ( 1967) classification, all ground water samples represent the borehole water type Na-Cl. All ground water samples were brackish ( 1000 mg/L < TDS < 1 0000 mg/L) according to Davis's ( 1964) TDS classification. Comparison of analytical results of the samples to earlier results shows that some changes have occurred between samplings. Other parameters, with couple of particular exceptions, have a downward trend, but bicarbonate concentration has increased in all boreholes. Concentrations of main parameters have changed most in OL-KR7 and OL-KR13 waters. Gas analyses results have not changed significantly, but increased carbon dioxide concentration is noticed in gas analysis results also. (orig.)

  1. Groundwater salinity at Olkiluoto and its effects on a spent fuel repository

    Energy Technology Data Exchange (ETDEWEB)

    Vieno, T. [VTT Energy, Espoo (Finland)

    2000-06-01

    The Olkiluoto island rose from the Baltic Sea 2500 to 3000 years ago. The layered sequence of groundwaters can be related to climatic and shoreline changes from modern tune through former Baltic stages to the deglaciation phase about 10 000 years ago and even to preglacial times. Fresh groundwater is found to the depth of about 150 metres, brackish between 100 and 400 metres, deeper groundwaters are saline. At the depth of 500 meters, the content of Total Dissolved Solids (TDS) varies between 10 and 25 g/l. The most saline waters at depths greater than 800 metres have TDS values between 30 and 75 g/l. These deep saline waters seem to have been undisturbed during the most recent glaciation and even much longer in the past. Today fresh water infiltrating at the surface gradually displaces brackish and saline groundwater in the bedrock. Due to the still ongoing postglacial land uplift, Olkiluoto is likely to become an inland site with brackish or fresh groundwater at the depth of 500 metres within the next 10 000 years. During the construction and operation phases groundwater will be drawn into the repository from the surrounding bedrock. As a consequence, more saline groundwaters, presently laying 100 to 200 metres below the repository level, may rise to the disposal level. After the closing of the repository the salinity distribution will gradually return towards the natural state. During the glacial cycle groundwater salinity may increase, for example, during freezing of groundwater into permafrost, when dissolved solids concentrate in the remaining water phase, and in a situation where deep saline groundwaters from under the centre of the glacier are pushed to the upper parts of the bedrock at the periphery of the glacier. The most significant open issue related to saline groundwater is the performance of the tunnel backfill which in the BS-3 concept has been planned to consist of a mixture of crushed rock and 10-30% of bentonite. Saline groundwater may

  2. Final disposal of spent nuclear fuel in Finnish bedrock. Olkiluoto site report

    Energy Technology Data Exchange (ETDEWEB)

    Anttila, P. [Fortum Engineering Oy, Vantaa (Finland); Ahokas, H. [Fintact Oy, Helsinki (Finland); Front, K. [VTT Communication and Infrastructure, Espoo (Finland)] [and others

    1999-06-01

    postglacial history of the island of Olkiluoto, which rose from the Baltic Sea some 2 500 - 3 000 years ago. The groundwater varies from modern fresh water near the surface to saline water at greater depths. Above 150 m current meteoric recharge and Baltic Sea water dominates. Below this a mixture of Litorina Sea water and glacial meltwater is dominant. Deeper below 500 m subglacial and older saline groundwater predominates. The maximum values for Total Dissolved Solids (TDS) and chloride content are 69.13 g/l and the 43 g/l, respectively. Reducing conditions are expected to exist at depth, which are favourable in terms of low radionuclide solubility and slow canister corrosion. Potentially suitable bedrock blocks have been identified at the site for locating a repository for spent fuel in the depth range of 400 - 700 m. No significant geotechnical, hydrogeological and hydrogeochemical constraints have been found to its construction, although it is recommended that certain fracture zones should be avoided when locating the deposition tunnels and disposal holes. In addition, the salinity of the groundwater will probably limit to some extent the types of constructional materials that can be used. (orig.) 323 refs.

  3. Engineering rock mass classification of the Olkiluoto investigation site

    Energy Technology Data Exchange (ETDEWEB)

    Aeikaes, K. [ed.; Hagros, A.; Johansson, E. [Saanio and Riekkola Consulting Engineers, Helsinki (Finland)] [and others

    2000-06-01

    Olkiluoto in Eurajoki is being investigated as a possible site for the final disposal of spent nuclear fuel from the Finnish nuclear power plants. The selection of the depth, placement and layout of the repository is affected by the constructability of the bedrock. The constructability, in turn, is influenced by several properties of the host rock, such as its Ethology, the extent of fracturing, its hydrogeological properties and rock engineering characteristics and also by the magnitude and orientation of the in situ stresses and the chemistry of the groundwater. The constructability can be evaluated by the application of a rock classification system in which the properties of the host rock are assessed against common rock engineering judgements associated with underground construction. These judgements are based partly on measurements of in situ stresses and the properties of the bedrock determined from rock samples, but an important aspect is also the practical experience which has been gained during underground excavation in similar conditions and rock types. The aim of the engineering rock mass classification was to determine suitable bedrock volumes for the construction of the repository and has used data from the site characterisation programme carried out at Olkiluoto, which consisted of both surface studies and borehole investigations. The classification specifies three categories of constructability - normal, demanding and very demanding. In addition, rock mass quality has also been classified according to the empirical Q-system to enable a comparison to be made. The rock mass parameters that determine the constructability of the bedrock at Olkiluoto depend primarily on the depth and the Ethology, as well as on whether construction takes place in intact or in fractured rock. The differences in the characteristics of intact rock within a single rock type have been shown to be small. The major lithological unit at Olkiluoto, the mica gneiss, lies in the

  4. KBS-3H layout adaptation 2007 for the Olkiluoto site

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, Erik; Hagros, Annika; Autio, Jorma; Kirkkomaeki, Timo (Saanio and Riekkola Oy, Helsinki (Finland))

    2008-05-15

    As part of the KBS-3H design an Olkiluoto-specific layout of a KBS-3H repository has been produced based on the latest Olkiluoto data and the bedrock model. One of the main goals of this work was to support the evaluation of the feasibility of the one layer KBS-3H concept and to compare the layouts based on the KBS-3H and KBS-3V disposal concepts. The layout presented in this work can be considered only preliminary and involves a number of uncertainties. The percentage of unusable host rock was assumed to be 25% in this work but can change due to the further design of the different components of the KBS-3H disposal system and further development of the host rock criteria. The layout is also significantly affected by the layout-determining fracture zones. In this work 11 major (highly transmissive) fracture zones interpreted to intersect the -420 m level were considered deterministically. The KBS-3H layout requires a larger area than the KBS-3V repository and takes up most of the available area between the major fracture zones HZ20 and HZ21. This is mainly due to the long drift sections occupied by the compartment plugs (30 m) and the bentonite blocks in the blank zones (10 m), which reduces the usability of the host rock and results in larger canister spacings than in the KBS-3V concept, where the positioning of the deposition holes is very flexible and narrow zones with a moderate transmissivity usually have only a minor effect on the locations of the canisters. According to the results, there is enough bedrock in the current investigation area at central Olkiluoto for KBS-3H layout in one layer. However the layout takes up nearly all of the potential bedrock resource and therefore the result is quite sensitive to possible changes in the design bases

  5. Environmental Impact Assessment for Olkiluoto 4 Nuclear Power Plant Unit in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Dersten, Riitta; Gahmberg, Sini; Takala, Jenni [Teollisuuden Voima Oyj, Olkiluoto, FI-27160 Eurajoki (Finland)

    2008-07-01

    In order to improve its readiness for constructing additional production capacity, Teollisuuden Voima Oyj (TVO) initiated in spring 2007 the environmental impact assessment procedure (EIA procedure) concerning a new nuclear power plant unit that would possibly be located at Olkiluoto. When assessing the environmental impacts of the Olkiluoto nuclear power plant extension project, the present state of the environment was first examined, and after that, the changes caused by the projects as well as their significance were assessed, taking into account the combined impacts of the operations at Olkiluoto. The environmental impact assessment for the planned nuclear power plant unit covers the entire life cycle of the plant unit. (authors)

  6. Discrete fracture network modelling of a KBS-3H repository at Olkiluoto

    Energy Technology Data Exchange (ETDEWEB)

    Lanyon, G.W. (Fracture Systems Ltd, St Ives (United Kingdom)); Marschall, P. (Nagra, Wettingen (Switzerland))

    2008-06-15

    This report presents Discrete Fracture Network (DFN) models of groundwater flow around a KBS-3H repository situated at Olkiluoto. The study was performed in support of the Safety Case for the KBS-3H Concept, being jointly studied by SKB and Posiva. As part of the preliminary assessment of long term safety of a KBS-3H repository, a Process Report and an Evolution Report (evolution of the disposal system from the emplacement of the first canister to the long term) are being produced. In the course of the task definition the project team identified the need for complementary modelling studies aimed at increasing insight into the hydrodynamic evolution of the disposal system after waste emplacement. In particular, the following issues were identified as requiring input from hydrodynamic models: Probability of high inflow points which may cause buffer erosion. Time transients of inflows after construction of deposition drifts. Interference between deposition drifts and transport tunnels. The DFN models represent the fault and fracture system in the planned repository volume at Olkiluoto. In particular, they represent the hydro geologically significant features. The types of hydrogeological features included in the models are: Major Fracture Zones (MFZs). Local Fracture Zones (LFZs) and associated water conducting features (LFZ-WCFs). Water Conducting Features in the background rock (BR-WCFs). These feature types are derived from the current geological and hydrogeological interpretations developed by Posiva. Several model variants were developed during the study and these variants were used for geometric simulations of the WCF network around the deposition drifts. A simple layout adaptation scheme has been applied to the network models to derive statistics for performance measures relating to the deposition drifts, compartments, plugs and super-containers. A single fracture transient flow model was developed to provide insight to transient flow behaviour around

  7. Migmatites and migmatite-like rocks of Olkiluoto

    Energy Technology Data Exchange (ETDEWEB)

    Kaerki, A. [Kivitieto Oy, Oulu (Finland)

    2015-02-15

    Bedrock of the Olkiluoto Island in the western end of the Palaeoproterozoic Svecofennian Accretionary Arc Complex, SW Finland is composed of high-grade metamorphic pelites, arenites and intermediate, arc type metavolcanic rocks intruded by granodioritic to tonalitic plutonic rocks. Regional metamorphism culminated with voluminous migmatization in the temperature of 660 - 700 deg C and relatively low pressure of about 3.5 - 4 kbar. The end result of polyphase metamorphism and deformation is a metamorphic rock succession composed of diverse migmatite rocks, metatexites and diatexites. Metatexites are migmatites in which several, discrete components can be detected, and in which the paleosome with some pre-partial-melting textures is identifiable. Diatexites are more advanced migmatites in which the pre-migmatization structures are often totally destroyed and the rock is dominated by different neosome components meaning leucosome, melanosome or mesosome. Based on the migmatite structures the metatexites of Olkiluoto have been classified into six subgroups. Dike-structured metatexites are composed of well preserved paleosome intruded by one single set of narrow, subparallel leucosome dikes which cover ca. 5 - 10 % of the whole rock volume. Net-structure is composed of a network of narrow leucosome dikes which show a reticulated structure in a plane section and cover less than 30 % of the whole rock volume. Breccia-structure is composed of angular or rounded paleosome blocks surrounded by moderate amount of leucosome. Patch-structure is composed of irregular leucosome patches which intruded the well preserved paleosome and compose typically 20 - 70 % of the rock volume. Layer-structure is characterized by more or less regular leucosome dikes sub-parallel to the foliation of the well preserved paleosome. Vein-structured metatexites and also diatexites include a set of pipe-like, longish leucosome veins most probably generated by synchronous melting and deformation

  8. Bentonite as a colloid source in groundwaters at Olkiluoto

    Energy Technology Data Exchange (ETDEWEB)

    Vuorinen, U. [VTT Processes, Espoo (Finland); Hirvonen, H.

    2005-02-15

    In this work bentonite was studied as a potential source of colloids in Olkiluoto groundwaters. Samples were collected at two groundwater stations, PVA1 at 37.5 m dept and PVA3 at 95.6 m depth, in the VLJ-tunnel. The deeper groundwater at PVA3 was more saline (2.6g/L of Cl-) than the shallow at PVA1 (0.8g/L of Cl-). A bentonite source had been assembled at each groundwater station so that two sample lines were available for water samples; one for collecting a sample before and the other for collecting a sample after interaction with bentonite. Before starting the actual colloid sampling groundwaters from both sample lines at both stations were analysed. Only minor alterations, mostly within the uncertainty limits of the analysis methods, were brought about in the water chemistries after interaction with the bentonite sources. The only clear changes were seen in the concentration of iron which decreased after interaction with bentonite in the groundwaters at both stations. After groundwater sampling the actual colloid sampling was performed. The water samples were collected and treated inside a movable nitrogen filled glove-box. The samples could be collected from each sampling line directly in the glove-box via two quick-couplings that had been assembled on the front face of the box. The sample lines had been assembled with 0.45 {mu}m filters before entering the glove-box, because only colloids smaller than 0.45 {mu}m were of interest, as they are not prone to sedimentation in slow groundwater flows and therefore could act as potential radionuclide carriers. Colloid samples were collected and treated similarly from both sampling lines at both groundwater stations. For estimating the colloid content the groundwater samples were filtered with centrifugal ultrafiltration tubes of different cut-off values (0.3 {mu}m, 300kD and 10kD). The ultrafiltrations produced the colloid-containing concentrate fractions and the soluble substances-containing filtrate fractions. In

  9. Characterization of Olkiluoto bacterial and archaeal communities by 454 pyrosequencing

    Energy Technology Data Exchange (ETDEWEB)

    Bomberg, M.; Nyyssoenen, M.; Itaevaara, M. [VTT Technical Research Centre of Finland, Espoo (Finland)

    2012-06-15

    Recent advancement in sequencing technologies, 'Next Generation Sequencing', such as FLX 454 pyrosequencing has made it possible to obtain large amounts of sequence data where previously only few sequences could be obtained. This technique is especially useful for the study of community composition of uncultured microbial populations in environmental samples. In this project, the FLX 454 pyrosequencing technique was used to obtain up to 20 000 16S rRNA sequences or 10 000 mRNA sequences from each sample for identification of the microbial species composition as well as for comparison of the microbial communities between different samples. This project focused on the characterization of active microbial communities in the groundwater at the final disposal site of high radioactive wastes in Olkiluoto by FLX 454 pyrosequencing of the bacterial and archaeal ribosomal RNA as well as of the mRNA transcripts of the dsrB gene and mcrA gene of sulphate reducing bacteria and methanogenic archaea, respectively. Specific emphasis was put on studying the relationship of active and latent sulphate reducers and methanogens by qPCR due to their important roles in deep geobiochemical processes connected to copper corrosion. Seven packered boreholes were sampled anaerobically in Olkiluoto during 2009-2010. Groundwater was pumped from specific depths and the microbial cells werecollected by filtration on a membrane. Active microbial communities were studied based on RNA extracted from the membranes and translated to copy DNA, followed by sequencing by 454 Tag pyrosequencing. A total of 27 different bacterial and 17 archaeal taxonomic groups were detected.

  10. Summary report - development of laboratory tests and the stress- strain behaviour of Olkiluoto mica gneiss

    Energy Technology Data Exchange (ETDEWEB)

    Hakala, M.; Heikkilae, E. [Helsinki Univ. of Technology, Espoo (Finland). Lab. of Rock Engineering

    1997-05-01

    This work summarizes the project aimed at developing and qualifying a suitable combination of laboratory tests to establish a statistically reliable stress-strain behaviour of the main rock types at Posiva Oy`s detailed investigation sites for disposal of spent nuclear fuel. The work includes literature study of stress-strain behaviour of brittle rock, development and qualification of laboratory tests, suggested test procedures and interpretation methods and finally testing of Olkiluoto mica gneiss. The Olkiluoto study includes over 130 loading tests. Besides the commonly used laboratory tests, direct tensile tests, damage controlled tests and acoustic emission measurements were also carried out. (orig.) (54 refs.).

  11. Models of bedrock surface and overburden thickness over Olkiluoto island and nearby sea area

    Energy Technology Data Exchange (ETDEWEB)

    Moenkkoenen, H. [WSP Finland Oy, Helsinki (Finland)

    2012-04-15

    In this report, a model of bedrock surface and a model of overburden thickness over the Olkiluoto Island and the nearby sea area are presented. Also in purpose to produce material for biosphere and radionuclide transport modelling, stratigraphy models of different sediment layers were created at two priority areas north and south of the Olkiluoto Island. The work concentrated on the collection and description of available data of bedrock surface and overburden thickness. Because the information on the bedrock surface and overburden is collected from different sources and is based on a number of types of data the quality and applicability of data sets varies. Consequently also the reliability in different parts of the models varies. Input data for the bedrock surface and overburden thickness models include 2928 single points and additional outcrops observations (611 polygons) in the modelled area. In addition, the input data include 173 seismic refraction lines (6534 points) and acousticseismic sounding lines (26655 points from which 13721 points are located in model area) in the Olkiluoto offshore area. The average elevation of bedrock surface in area is 2.1 metres above the sea level. The average thickness of overburden is 2.5 metres varying typically between 2 - 4 metres. Thickest overburden covers (approximately 16 metres) of terrestrial area are located at the western end of the Olkiluoto Island and in sea basin south of the island. (orig.)

  12. Studies on the aquatic environment at Olkiluoto and reference area. 1: Olkiluoto, reference lakes and Eurajoki and Lapijoki rivers in 2009-2010

    Energy Technology Data Exchange (ETDEWEB)

    Kangasniemi, V. [Environmental Research and Assessment EnviroCase Ltd., Pori (Finland); Helin, J.

    2014-03-15

    This working report presents the first results of a sampling campaign at Olkiluoto and reference lakes and rivers selected to resemble the aquatic systems expected to form at the site in the future with the post-glacial crustal rebound (land uplift). In 2009-2010, the aim of the studies was to improve the knowledge of the aquatic systems and to produce input data to the safety case for the spent nuclear fuel repository at Olkiluoto. The first main objective was to estimate the areal biomass distribution and measure the dimensions of characteristic aquatic plants and animals. Another objective was to estimate the transfer of different elements from water to the aquatic organisms paying special attention on key elements (Ag, Cl, I, Mo, Nb and Se) in the dose assessment within the safety case. Surface water, sediment, macrophyte, fish and macrobenthos samples were collected from the Olkiluoto coastal area and from the reference lakes for biomass and dimension measurements and analysis of element concentration. Water-to-biota concentration ratios were estimated for the coastal area and for the reference lakes. From rivers, only water samples were collected at this stage. In 2009-2010, sampling procedures and pre-treatment methods were developed and analytical methods were optimised. Thus, the results reported here are indicative by their nature. After 2010, the studies have been continued with better established methods, and the more recent results will be reported later. (orig.)

  13. Seafloor mapping at Olkiluoto western coast of Finland

    Energy Technology Data Exchange (ETDEWEB)

    Ilmarinen, K.; Leinikki, J.; Oulasvirta, P. (Alleco Oy, Helsinki (Finland))

    2009-02-15

    The objective of the study was to investigate the seafloor of shallow areas around Olkiluoto island, western Finland. The surveys were carried out by Alleco Ltd. Posiva will use the data for modeling purposes. The investigations included bathymetric surveys, sediment sampling and assessment of benthic macrophytes and macrozoobenthos in the underwater parts of six pre-defined survey transects extending from land to the sea. Sediment sampling and the assessment of benthic organisms were done by SCUBA diving. The study area showed a great variation in environmental conditions. Olkiluoto stands between almost open sea and extremely sheltered river mouth area of Lapinjoki. Two of the transects were more than 7 meters deep and included both hard and soft sand bottom. Whereas rest of the transects were shallow with mostly soft clay, mud and silt bottom. Altogether 27 species of algae including five species of stoneworts (Charophyta), one species of water moss (Bryophyta) and 16 species of vascular plants (Tracheophyta) were found. The most abundant group was vascular plants, between the other groups of macroalgae big differences in the abundance were not seen. Furthermore altogether 43 species of macrozoobenthos (Invertebrata) were found, of which six species were sessile bottom fauna (permanently attached fauna). The most abundant groups in the bottom samples were bivalves (Lamellibranchiata) (996 individuals per m2), snails (Gastropoda) (739 individuals per m2) and polychaetes (Polychaeta) (542 individuals per m2). The total abundance of macrozoobenthos on all transects was 2 899 individuals per m2. The biggest groups by biomass were bivalves (fresh weight 87 054 mg per m2) and polychaetes (fresh weight 12 983 mg per m2). Transect 1 was the richest in number of species of the deep and exposed transects 1 and 2. The transect 5 had the highest diversity of all the shallow soft bottom transects 3, 4, 5 and 5a. The high diversity of the transect 1 and 5 may be explained by

  14. Site scale groundwater flow in Olkiluoto - complementary simulations

    Energy Technology Data Exchange (ETDEWEB)

    Loefman, J. [VTT Energy, Espoo (Finland)

    2000-06-01

    This work comprises of the complementary simulations to the previous groundwater flow analysis at the Olkiluoto site. The objective is to study the effects of flow porosity, conceptual model for solute transport, fracture zones, land uplift and initial conditions on the results. The numerical simulations are carried out up to 10000 years into the future employing the same modelling approach and site-specific flow and transport model as in the previous work except for the differences in the case descriptions. The result quantities considered are the salinity and the driving force in the vicinity of the repository. The salinity field and the driving force are sensitive to the flow porosity and the conceptual model for solute transport. Ten-fold flow porosity and the dual-porosity approach retard the transport of solutes in the bedrock resulting in brackish groundwater conditions at the repository at 10000 years A.P. (in the previous work the groundwater in the repository turned into fresh). The higher driving forces can be attributed to the higher concentration gradients resulting from the opposite effects of the land uplift, which pushes fresh water deeper and deeper into the bedrock, and the higher flow porosity and the dual-porosity model, which retard the transport of solutes. The cases computed (unrealistically) without fracture zones and postglacial land uplift show that they both have effect on the results and can not be ignored in the coupled and transient groundwater flow analyses. The salinity field and the driving force are also sensitive to the initial salinity field especially at the beginning during the first 500 years A.P. The sensitivity will, however, diminish as soon as fresh water dilutes brackish and saline water and decreases the concentration gradients. Fresh water conditions result in also a steady state for the driving force in the repository area. (orig.)

  15. Climate scenarios for Olkiluoto on a time-scale of 120,000 years

    Energy Technology Data Exchange (ETDEWEB)

    Pimenoff, N.; Venaelaeinen, A.; Jaervinen, H. [Finnish Meteorological Institute, Helsinki (Finland)

    2011-12-15

    Posiva Oy is planning to dispose of spent nuclear fuel in a repository, to be constructed at a depth of 400 m in the crystalline bedrock at Olkiluoto, Finland. Planning the storage requires careful consideration of many aspects, including an assessment of long-term repository safety. For estimating possible climate states at Olkiluoto on a time-scale of 120,000 years, we analyze climate simulations of an Earth System Model of Intermediate Complexity (CLIMBER-2) coupled with an ice sheet model (SICOPOLIS). The simulations into the future clearly show that the onset of the next glaciation is strongly dependent on the Earth's orbital variations and the atmospheric CO{sub 2} concentration. It is evident that due to global warming, the climate of the next centuries will be warmer and wetter than at present. Most likely, due to global warming and low variations in the Earth's orbit around the sun, the present interglacial will last for at least the next 30,000 years. Further, the future simulations showed that the insolation minima on the Northern Hemisphere 50,000-60,000 and 90,000-100,000 years after the present hold a potential for the onset of the next glaciation. Hence, on a time-scale of 120,000 years, one must take into account climate periods lasting several thousand years having the following features: an interglacial climate, a periglacial climate, a climate with an ice sheet margin near Olkiluoto, a glacial climate with an ice sheet covering Olkiluoto, and a climate with Olkiluoto being depressed below sea level after glaciation due to isostatic depression. Due to the uncertainties related to the evolution of the future climate, it is recommended the simulations into the far future to be used only qualitatively. Quantitative information about glacial climate is achieved from the reconstructions and simulations of the past climate. (orig.)

  16. Fracture calcites at Olkiluoto. Evidence from quaternary infills for palaeohydrogeology

    Energy Technology Data Exchange (ETDEWEB)

    Gehoer, S.; Kaerki, A.; Taikina-aho, O. [Kivitieto Oy (Finland); Karhu, J. [Helsinki Univ. (Finland); Loefman, J. [VTT Processes, Espoo (Finland); Pitkaenen, P. [VTT Building and Transport, Espoo (Finland); Ruotsalainen, P. [TUKES, Helsinki (Finland)

    2002-02-01

    Recently formed secondary minerals, predominantly calcite, occur in varying amounts as fracture infills, and the calcite types, their chemical compositions and isotope ratios reflect the compositions and physicochemical factors of the groundwater system in which they were formed. Fluid inclusions trapped in calcites give direct evidence of trapping temperatures and past salinities and of the chemical compositions of the palaeo fluids. A wide range of mineralogical and geochemical examinations were carried out within the EQUIP project to examine features of this kind. The fracture calcites at the Olkiluoto site are of various origins and represent several textural types. The exact number of calcite-producing events is unknown, but the duration of the period that was appropriate for the precipitation of low temperature calcite is estimated to have exceeded 1000 Ma. Thus the number of genetically related calcite units is assumed to be considerable. This study was focused on the petrogenesis of calcites crystallized in fractures of high water conductivity during the latest stages of geological evolution. The majority of these late stage calcites form physically homogeneous, scaly layers, and in a few cases thin layers composed of idiomorphic crystals. Chemically these are almost stoichiometric calcites (CaCO{sub 3}). The MnO content may exceed 1%, while the amounts of other elements present are minor, although the trace element concentrations, particularly those of large ionic trace elements, can be used as distinguishing features for the recognition of individual precipitates representing different calcite generations. Evidence from fluid inclusions, or more correctly from the absence of these in the late stage calcites, can be interpreted as an indication of slow rates of crystallization under cool conditions. Many chemical variables, e.g. oxygen isotope ratios, demonstrate an equilibrium between the latest calcites and water similar to the present groundwater. Older

  17. Estimated quantities of residual materials in a KBS-3H repository at Olkiluoto

    Energy Technology Data Exchange (ETDEWEB)

    Hagros, Annika (Sannio and Riekkola OY (Finland))

    2008-12-15

    The quantities of residual materials in a KBS-3H type repository have been estimated in this report. The repository is assumed to be constructed at Olkiluoto in Eurajoki, Western Finland. Both the total quantities of the materials introduced into the repository and the quantities of materials that remain in the repository after closure have been calculated. The calculations are largely based on a similar work regarding the material quantities in the Finnish KBS-3V repository and the main goal has been to identify the differences between the KBS-3H and KBS-3V repositories with respect to the type and quantities of residual materials. As the design of the KBS-3H repository is not final yet, the results are only preliminary. Several alternative designs were assumed in the calculations, resulting in different total quantities of materials. The design alternatives that had the greatest effect on the total material quantities were the two different tunnel backfill options, bentonite-crushed rock and Friedland clay. If Friedland clay is used instead of a bentonite-crushed rock mixture, the total quantity of pyrite remaining in the repository is 20 times larger and the quantities of organic materials and gypsum are also increased significantly. The other design alternatives did not have a substantial effect on the total material quantities. The remaining quantity of cement can be reduced by some 20% by selecting the silica grouting alternative in the sealing of the rock mass and low-pH cement in the shotcreting of the repository, instead of using the ordinary cement alternatives. If the total quantity of steel should be minimised, the use of the DAWE design alternative would be better than the Basic Design, although the total reduction would be less than 10%. The main difference between the different drift end plug alternatives is related to the total remaining quantity of silica, which is some 80% smaller if the rock plug is used instead of the LHHP (Low Heat High

  18. Evaluation of the radioactive waste characterisation at the Olkiluoto nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Kekki, T.; Titta, A. [VTT Chemical Technology, Espoo (Finland)

    2000-03-01

    The aim of this study is to evaluate the physical, chemical and radiological characterisation, handling and documentation of the radioactive waste packages to be disposed of in the VLJ-repository at the Olkiluoto NPP. A comparison with the current practices in Europe, based on information from Sweden, Spain and Czech Republic, is made. The report presents recommendations for STUK to harmonise the LILW waste management practises in Finland with those in Europe. (orig.)

  19. Concentration ratios to great cormorant (Phalacrocorax carbo) at Olkiluoto repository site

    Energy Technology Data Exchange (ETDEWEB)

    Kangasniemi, Ville; Ikonen, Ari T.K. [Environmental Research and Assessment EnviroCase, Ltd., Hallituskatu 1 D 4, 28100 Pori (Finland); Haavisto, Fiia [FM Meri and Erae Oy, Seijaistentie 133a, 21230 Lemu (Finland); Salmi, Juhani A. [Finnish Game and Fisheries Research Institute, Itaeinen Pitkaekatu 3, 20520 Turku (Finland)

    2014-07-01

    Olkiluoto Island on the western coast of Finland has been selected as a repository site for spent nuclear fuel disposal. The great cormorant was a common species in the Finnish coastal area and possibly also a resource for human uses before the decline of the cormorant population in the 18. century. During the last decade, the great cormorant has become again a relevant part of food web in the Bothnian Sea coastal area. Due to the regulatory requirements, the biosphere assessment demonstrating the long-term safety of the repository is developed into more and more site specific. As the adequate literature data on common waterfowl is sparse or in some cases lacking, samples of adult cormorants, eggs and guano together with water and fish samples were collected from the Olkiluoto coastal area. This contribution will present concentration ratios of stable element based on these samples with focus on the elements of a high relevance to the biosphere assessment of the Olkiluoto spent fuel repository together with discussion on the role of food (fish) versus the application of the water-to-bird concentration ratio. (authors)

  20. Geomicrobial investigations of groundwaters from Olkiluoto, Haestholmen, Kivetty and Romuvaara, Finland

    Energy Technology Data Exchange (ETDEWEB)

    Haveman, S.A.; Pedersen, K. [Goeteborg Univ. (Sweden); Ruotsalainen, P. [Fintact Oy, Helsinki (Finland)

    1998-08-01

    Groundwater from four deep hard rock sites being considered for nuclear waste disposal in Finland (Olkiluoto, Haestholmen, Kivetty and Romuvaara) were investigated for microbial populations. Bacteria will be present in a waste disposal vault, so it is important to understand the microbiology of any potential site. Groundwater samples were collected from 200 to 950 m depth and included fresh, brackish and saline waters. Samples were collected with a pressurized groundwater sampler, PAVE, which is an excellent tool for microbiological sampling. Total cell numbers were typical for deep groundwater, 105 to 106 cells/ml. Growth media designed using groundwater chemistry data were used for enumeration of methanogens, acetogens, sulfate reducing bacteria (SRB) and iron reducing bacteria (IRB). Microbial populations varied between sites. Iron sulfide fracture minerals are common in the brackish high sulfate groundwaters of Olkiluoto, where SRB predominated. Haestholmen groundwater has high dissolved iron, iron hydroxide fracture minerals and IRB were the main microbial population. Kivetty and Romuvaara had mixed populations. It has been proposed that deep subsurface ecosystems are based on hydrogen and carbon dioxide which provide energy and carbon to support the food chain. Signs of such an ecosystem were seen in Olkiluoto. More study is needed to understand the basis for deep subsurface life. From a microbiological point of view, all sites investigated are equally suitable for nuclear waste disposal. (orig.) 66 refs.

  1. Comparison of Olkiluoto (Finland) and Forsmark (Sweden) candidate sites for radioactive-waste disposal

    Science.gov (United States)

    Geier, J. E.; Bath, A.; Stephansson, O.; Luukkonen, A.

    2012-12-01

    Site characterizations for deep radioactive-waste repositories consider rock properties, groundwater conditions, and the influences of regional settings and site-specific evolution. We present a comparison of these aspects for two candidate repository sites that have similar rocks and coastal settings, but are 200 km apart on opposite sides of the Gulf of Bothnia. The Olkiluoto site in Finland and the Forsmark site in Sweden are both in hard crystalline rock (migmatite gneiss and metagranite, respectively) with groundwater flow mainly via fractures. Both sites are undergoing licensing for a high-level radioactive-waste repository. The licensing is stepwise in Finland, and operation in both countries will be strictly regulated, but all responsibility lies with the implementers until accepted closure. The comparison reveals many expected similarities but also unexplained differences, which illustrate the complexities of site characterization in fractured crystalline rock. Both sites underwent a similar sequence of hydrologic conditions over the Weichselian and earlier glacial cycles. Hydrogeologically, Forsmark has more conductive upper bedrock, contributing to a very flat water table. Deep bedrock at Olkiluoto is more fractured in the horizontal plane. At repository depth and below, Forsmark likely contains larger volumes of low-conductivity rock. At both sites, the local model is connected to regional-scale boundaries via submarine deformation zones which (especially at Olkiluoto) are poorly characterized. Stress measurements at the two sites have shown that vertical stress is in agreement with the weight of overburden while horizontal stresses differ in magnitude and orientation. Interpreted overcoring stress measurements from Forsmark are almost twice the magnitudes estimated from hydraulic methods. Rock mechanical differences include the possibility that Olkiluoto bedrock is more prone to spalling than Forsmark. Olkiluoto bedrock is more anisotropic in terms of

  2. Site-to-canister scale flow and transport in Haestholmen, Kivetty, Olkiluoto and Romuvaara

    Energy Technology Data Exchange (ETDEWEB)

    Poteri, A.; Laitinen, M. [VTT Energy, Espoo (Finland)

    1999-05-01

    Radioactive waste is originating from production of electricity in nuclear power plants. Most of the waste has only low or intermediate levels of radioactivity. However, the spent nuclear fuel is highly radioactive and it has to be isolated from the biosphere. The current nuclear waste management plan in Finland is based on direct disposal of the spent nuclear fuel deep underground. The only feasible mechanism for the radionuclides to escape from an underground repository is to be carried by the groundwater flow after the failure of waste containers. The scope of this study is to examine the groundwater flow situation and transport properties in the vicinity of the disposal canister and along the potential release paths from the repository into the biosphere. The results of this study are further applied in the site specific safety analysis of a spent fuel repository. Synthesis is made of the porous medium estimates of the groundwater flow in the regional and site scales and the detailed fracture network analysis of the flow in the canister scale. This synthesis includes estimation of the transport properties from the canister into the biosphere and flow rates around the deposition holes of the waste canisters. The modelling has been carried out for four different sites: Hastholmen, Kivetty, Olkiluoto and Romavaara. According to the simulations groundwater flow rate around the deposition holes is less than about 1 litre/a for about 75 % of the deposition holes. For about 5 % of the deposition holes the flow rates are a few litres per year or higher. The highest flow rates resulted at Hastholmen, in fresh water conditions 10 000 years after present, and at Kivetty. The transport resistances were calculated for the `worst` flow paths that might have impact on the safety of the repository. The total transport resistances from the repository into the biosphere along those flow paths varied between about 40 000 a/m and 5-10{sup 6} a/m. Most of the total transport

  3. ONKALO pose experiment. Geophysical logging and imaging of drillholes ONK-PP223, ONK-PP226, ONK-PP254 and ONK-PP259...261

    Energy Technology Data Exchange (ETDEWEB)

    Tarvainen, A.-M. (Suomen Malmi Oy, Espoo (Finland))

    2011-08-15

    Suomen Malmi Oy conducted geophysical drillhole logging as well as optical and acoustic imaging of shallow drillholes ONK-PP223, ONK-PP226, ONK-PP254, ONKPP259, ONK-PP260 and ONK-PP261 at ONKALO in the investigation niche ONKTKU- 3 (POSE) between December 2009 and June 2010. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The assignment included the field work and data processing. The report describes field operation, equipment as well as processing procedures and shows the obtained results and an analysis of their quality in the appendices. The raw and processed data are delivered digitally in WellCAD, PDF and Excel format. (orig.)

  4. Safety case for the disposal of spent nuclear fuel at Olkiluoto. Complementary considerations 2012

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-12-15

    Complementary Considerations sits within Posiva Oy's Safety Case 'TURVA-2012' report portfolio and has the objective of enhancing confidence in the outcomes of the safety assessment for a spent nuclear fuel repository to be constructed at Olkiluoto, Finland. The main emphasis in this report is on the evidence and understanding that can be gained from observations at the site, including its regional geological environment, and from natural and anthropogenic analogues for the repository, its components and the processes that affect safety. In particular, the report addresses diverse and less quantifiable types of evidence and arguments that are enclosed to enhance confidence in the outcome of the safety assessment. These complementary considerations have been described as evaluations, evidence and qualitative supporting arguments that lie outside the scope of the other reports of the quantitative safety assessment. The experience with natural analogues for the long-term durability of the materials involved and the extent of processes provides high confidence in our understanding of the disposal system and its evolution. For each engineered barrier and key process, there is increasing analogue evidence to support the conceptual models and parameters. Regarding the suitability of the Olkiluoto site to host a spent fuel repository, a number of factors have been identified that indicate the suitability of crystalline host rock in general, and that of the Olkiluoto site in particular. The report also provides radiation background information for the use of complementary indicators, which aid in putting the results of the safety analysis presented in Assessment of Radionuclide Release Scenarios for the Repository System and Biosphere Assessment in a broader perspective to show that the radiation originating from a spent nuclear fuel repository remains in most cases much below natural background radiation or that caused by non-nuclear industries. (orig.)

  5. Regional distribution of microbes in groundwater from Haestholmen, Kivetty, Olkiluoto and Romuvaara, Finland

    Energy Technology Data Exchange (ETDEWEB)

    Haveman, S.A.; Nilsson, E.L.; Pedersen, K. [Goeteborg University (Sweden)

    2000-06-01

    Groundwater was sampled with the PAVE groundwater sampling system from eight boreholes at Haestholmen, Kivetty, Olkiluoto and Romuvaara, Finland, in 1998 and 1999, for investigation of microbial populations. The groundwater samples had a wide range of salinity and chemistry and contained 104-105 cells per ml, which is typical for subsurface groundwater. In preparing culture media, two approaches were used and compared. Natural, groundwater-based media were prepared from groundwater from the same section of each borehole tested, and synthetic media were prepared based on groundwater chemistry data. No significant difference was observed between the two types of media for brackish and saline groundwater. The groundwater to a depth of 750 m contained mainly sulphate-reducing bacteria (SRB), ironreducing bacteria (IRB) and heterotrophic acetogenic (HA) bacteria. Autotrophic acetogenic (AA) bacteria and methanogenic archaea were found in some samples. Iron-reducing and HA bacteria predominated in brackish groundwater from Haestholmen, with SRB present in smaller numbers. A different microbial population was found in deep saline groundwater from Haestholmen and Olkiluoto that consists of a large proportion of a saline or brine end member. No SRB or AA bacteria were cultured; instead, the microbial population consisted of HA bacteria and either IRB or methanogens. In Olkiluoto, SRB predominated in the brackish and saline groundwater at depths to about 500 m, while methanogens were found in deeper saline groundwater. Stable isotope data (C-13) indicated that the methanogens are part of an autotrophic population consuming dissolved inorganic carbon (DIC) and hydrogen and producing methane and organic carbon. This deep ecosystem may be independent of surface life processes. A high-level radioactive waste (HLW) repository at 500 m depth in the Fennoscandian Shield will be inhabited by SRB, IRB and acetogens. Methanogens may also be present. These anaerobic micro

  6. Safety case for the disposal of spent nuclear fuel at Olkiluoto - Synthesis 2012

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-12-15

    TURVA-2012 is Posiva's safety case in support of the Preliminary Safety Analysis Report (PSAR 2012) and application for a construction licence for a spent nuclear fuel repository. Consistent with the Government Decisions-in- Principle, this foresees a repository developed in bedrock at the Olkiluoto site according to the KBS-3 method, designed to accept spent nuclear fuel from the lifetime operations of the Olkiluoto and Loviisa reactors. Synthesis 2012 presents a synthesis of Posiva Oy's Safety Case 'TURVA-2012' portfolio. It summarises the design basis for the repository at the Olkiluoto site, the assessment methodology and key results of performance and safety assessments. It brings together all the lines of argument for safety, evaluation of compliance with the regulatory requirements, and statement of confidence in long-term safety and Posiva's safety analyses. The TURVA-2012 safety case demonstrates that the proposed repository design provides a safe solution for the disposal of spent nuclear fuel, and that the performance and safety assessments are fully consistent with all the legal and regulatory requirements related to long-term safety as set out in Government Decree 736/2008 and in guidance from the nuclear regulator - the STUK. Moreover, Posiva considers that the level of confidence in the demonstration of safety is appropriate and sufficient to submit the construction licence application to the authorities. The assessment of long-term safety includes uncertainties, but these do not affect the basic conclusions on the long-term safety of the repository. (orig.)

  7. Nuclear power plant Olkiluoto 3. Containment leakage test under extreme conditions

    Energy Technology Data Exchange (ETDEWEB)

    Fleckenstein, Tobias [TUEV SUED Industrie Service GmbH, Munich (Germany). Measaruement Technology Dept.

    2015-01-15

    Modern nuclear power plants place high demands on the design and execution of safety checks. TUEV SUED supported the containment leakage test for the largest- capacity third generation nuclear power plant in the world - Olkiluoto 3 in Finland. The experts successfully met the challenges presented by exceptional parameters of the project. The containment of Olkiluoto 3 is unique in that the vessel's volume is 80,000 m{sup 3} while measurements were carried out over a period of ten days. To execute the test, 75 temperature and 15 humidity sensors had to be installed and correctly interlinked by more than ten kilometres of cable. These instruments also needed to withstand an absolute pressure of 6 bar, ambient temperatures of 30 C and high levels of humidity. These conditions required comprehensive preparation and a high amount of qualification tests. Parts of the qualifications were carried out at the autoclave system of the Technical University in Munich, Germany, where the project test conditions could be simulated. The software required to determine the tests was developed by TUEV SUED and verified by German's national accreditation body DAkkS under ISO 17025. TUEV SUED enabled the test schedule to continue without delay by analysing all recorded data continuously on site, including pressure, temperature, humidity and leakage mass flow curves. With the comprehensive preparation, data acquisition system recording measurements continuously and the on-time result calculation, all components of the leak-tightness assessment were successfully completed in accordance with requirements.

  8. On detonation dynamics in hydrogen-air-steam mixtures: Theory and application to Olkiluoto reactor building

    Energy Technology Data Exchange (ETDEWEB)

    Silde, A.; Lindholm, I. [VTT Energy, Espoo (Finland)

    2000-02-01

    This report consists of the literature study of detonation dynamics in hydrogen-air-steam mixtures, and the assessment of shock pressure loads in Olkiluoto 1 and 2 reactor building under detonation conditions using the computer program DETO developed during this work at VTT. The program uses a simple 1-D approach based on the strong explosion theory, and accounts for the effects of both the primary or incident shock and the first (oblique or normal) reflected shock from a wall structure. The code results are also assessed against a Balloon experiment performed at Germany, and the classical Chapman-Jouguet detonation theory. The whole work was carried out as a part of Nordic SOS-2.3 project, dealing with severe accident analysis. The initial conditions and gas distribution of the detonation calculations are based on previous severe accident analyses by MELCOR and FLUENT codes. According to DETO calculations, the maximum peak pressure in a structure of Olkiluoto reactor building room B60-80 after normal shock reflection was about 38.7 MPa if a total of 3.15 kg hydrogen was assumed to burned in a distance of 2.0 m from the wall structure. The corresponding pressure impulse was about 9.4 kPa-s. The results were sensitive to the distance used. Comparison of the results to classical C-J theory and the Balloon experiments suggested that DETO code represented a conservative estimation for the first pressure spike under the shock reflection from a wall in Olkiluoto reactor building. Complicated 3-D phenomena of shock wave reflections and focusing, nor the propagation of combustion front behind the shock wave under detonation conditions are not modeled in the DETO code. More detailed 3-D analyses with a specific detonation code are, therefore, recommended. In spite of the code simplifications, DETO was found to be a beneficial tool for simple first-order assessments of the structure pressure loads under the first reflection of detonation shock waves. The work on assessment

  9. Eurajoki Olkiluoto study on species of ground beetles and ants 2008

    Energy Technology Data Exchange (ETDEWEB)

    Santaharju, J.; Helminen, S.-L.; Yrjoelae, R. (Environmental Research Yrjoelae Ltd, Helsinki (Finland))

    2009-02-15

    The species of ants and Ground beetles at Olkiluoto in Eurajoki were studied in the summer of 2008 during two trapping periods: in June and August. The research goal was to clarify the species on Olkiluoto island of the earlier mentioned groups, at least at the family level, and to collect samples for further examination by Posiva. The trapping areas were selected at Olkiluoto in Posiva test monitoring sectors, a part of the trapping areas was the same as the earlier study. Species of ants, depending on their particular species, are a very dominating group of insects. The ants are the most important predators, scavengers and soil movers in Finnish forests. It looks as if the biomass of ants may be more than 10% of the biomass of all animals in certain areas of Finnish forests. In Finland there are about 60 species of ants that have been observed. They have been divided into four sub-groups, which are Myrmicinae, Formicinae, Ponerinae and Dolichoderinae. In Finland there are close to 300 species of ground beetles (Carabidae), which are divided into dozens of different families. The species, to a great extent, consist mostly of predatory insects that prey on microbes in field layers, but a part of them are specialized in feeding on flora. Ground beetles are usually divided into three groups according to their choice of habitat: Species that favour open biotopes, species that favour forests, and generalist species that can thrive in a variety of environments. Ground beetles also reflect changes in their living environment, and possibly they can be significant as socalled bio-indicators. Pitfall traps were used as the method of research. The preservative fluid used was ethanol (50%) with dishwashing liquid to remove surface tension. The points were located in various different biotopes in fields, meadows and forests. The data collected was defined as a minimum for the family level of Ground beetles and for ants to the species or species pairs. The species of Ground

  10. Stable isotope signatures of gases liberated from fluid inclusions in bedrock at Olkiluoto

    Energy Technology Data Exchange (ETDEWEB)

    Eichinger, F. (Hydroisotop GmbH, Schweitenkirchen (DE)); Meier, D.; Haemmerli, J.; Diamond, L. (Bern Univ. (CH), RWI, Institute of Geological Sciences)

    2010-12-15

    Fluid inclusions in quartzes of the Olkiluoto bedrock contain gaseous N{sub 2}, CO{sub 2}, H{sub 2}, CH{sub 4}, and higher hydrocarbons in varying proportions. Stable carbon and hydrogen isotope signatures of the gas phases give valuable information on their origin and the formation conditions. In previous studies, a method to liberate and quantify the gases trapped in fluid inclusions was developed. It allowed determining the carbon isotope signatures of liberated CO{sub 2}, CH{sub 4} and higher hydrocarbons (HHC), but no hydrogen isotope data were acquired. The method was advanced and, in this study, also stable hydrogen isotopes of CH{sub 4} and H{sub 2} liberated from fluid inclusions could be analysed. The stable carbon signatures of methane and higher hydrocarbons, as well as the hydrogen isotope signatures of methane indicate a predominant thermogenic provenance for those gases. (orig.)

  11. Core drilling of deep drillhole OL-KR56 at Olkiluoto in Eurajoki 2011 - 2012

    Energy Technology Data Exchange (ETDEWEB)

    Toropainen, V. [Suomen Malmi Oy, Espoo (Finland)

    2012-07-15

    As a part of the confirming site investigations at Olkiluoto, Suomen Malmi Oy (Smoy) core drilled a 1201.65 m deep drillhole with a diameter of 75.7 mm at Olkiluoto in October 2011 - January 2012. The identification number of the drillhole is OL-KR56. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the returning and drilling water were recorded. The drill rig was computer controlled and the computer recorded drilling parameters during drilling. The objective of the measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The total volume of the used drilling, washing and flushing water was 1628 m{sup 3}. The measured volume of the returning water in the drillhole was 1142 m{sup 3}. The deviation of the drillhole was measured with the deviation measuring instruments Reflex EMS and Reflex Gyro. The main rock types are veined and diatexitic gneisses, pegmatitic granite and mica gneiss. The average fracture frequency is 2.4 pcs/m and the average RQD value is 96.2 %. Fifty fractured zones were penetrated by the drillhole. Uniaxial compressive strength, Young's Modulus and Poisson's ratio were measured from the core samples. The average uniaxial compressive strength was 120.0 MPa, the average Young's Modulus was 38.3 GPa and the average Poisson's ratio was 0.22. (orig.)

  12. GPS monitoring of bedrock stability at Olkiluoto nuclear waste disposal site in Finland from 1996 to 2012

    Science.gov (United States)

    Nyberg, S.; Kallio, U.; Koivula, H.

    2013-09-01

    The Finnish Geodetic Institute has studied crustal deformations at Olkiluoto nuclear waste disposal site since mid-90's. Biannual GPS measurement has been carried out in two local GPS networks. This paper analyses the GPS data processing effects on the coordinate solutions and presents the results of GPS monitoring from 1996 to 2012. The GPS data was processed using Bernese GPS Software 5.0. The GPS data processing and baseline analysis showed a 1.0 mm (max RMS) level agreement of observation and high bedrock stability in the area. Most of the horizontal trends were smaller than 0.1 mm/a. The troposphere estimation strategy had a clear effect on the horizontal trends at some sites. The strain rates were all very small, but we could detect motions near the Olkiluoto permanent station.

  13. Forest soil survey and mapping of the nutrient status of the vegetation on Olkiluoto island. Results from the first inventory on the FEH plots

    Energy Technology Data Exchange (ETDEWEB)

    Tamminen, P.; Aro, A.; Salemaa, M. (Finnish Forest Research Institute, Helsinki (Finland))

    2007-09-15

    The aim of the inventory was to determine the status of the forest soils and to map the current nutrient status of forest vegetation on Olkiluoto Island in order to create a basis for monitoring future changes in the forests and to provide data for a biospheric description of the island. The study was carried out on 94 FEH plots, which were selected from the forest extensive monitoring network (FET plots) on the basis of the forest site type distribution and tree stand characteristics measured on the island during 2002 - 2004. Forest soils on Olkiluoto are very young and typical of soils along the Finnish coast, i.e. stony or shallow soils overlying bedrock, but with more nutrients than the forest soils inland. In addition to nutrients, the heavy metal concentrations are clearly higher on Olkiluoto than the average values for Finnish forest soils. The soil in the alder stands growing along the seashore is different from the other soils on Olkiluoto and the control soils inland. These soils are less acidic and have large reserves of sodium, magnesium and nitrogen. Macronutrient concentrations in vascular plant species were relatively similar to those reported for Southern Finland. However, it is obvious that the accumulation of particulate material on the vegetation, especially on forest floor bryophytes, has increased due to emissions derived from the construction of roads, drilling and rock crushing, as well as the other industrial activities on Olkiluoto Island. Leaf and needle analysis indicated that the tree stands had, in the main, a good nutrient status on Olkiluoto Island. The surveying methods used on Olkiluoto are better suited to detect systematic changes over a larger area or within a group of sample plots than the changes on individual plots. (orig.)

  14. Geochemical modelling of groundwater evolution and residence time at the Olkiluoto site

    Energy Technology Data Exchange (ETDEWEB)

    Pitkaenen, P.; Luukkonen, A. [VTT Communities and Infrastructure, Espoo (Finland); Ruotsalainen, P. [Fintact Oy (Finland); Leino-Forsman, H.; Vuorinen, U. [VTT Chemical Technology, Espoo (Finland)

    1999-05-01

    An understanding of the geochemical evolution of groundwater is an essential part of the performance assessment and safety analysis of the final disposal of radioactive waste into the bedrock. The performance of technical barriers and migration of possibly released radionuclides depend on chemical conditions. A prerequisite for understanding these factors is the ability to specify the water-rock interactions which control chemical conditions in groundwater. The objective of this study is to interpret the processes and factors which control the hydrogeochemistry, such as pH and redox conditions. A model of the hydrogeochemical progress in different parts of the crystalline bedrock at Olkiluoto has been created and the significance of chemical reactions and groundwater mixing along different flowpaths calculated. Long term hydrodynamics have also been evaluated. The interpretation and modelling are based on water samples (63 altogether) obtained from precipitation, Baltic Sea, soil layer, shallow wells in the bedrock, and eight deep boreholes in the bedrock for which a comprehensive data set on dissolved chemical species and isotopes was available. Some analyses of dissolved gases and fracture calcite and their isotopic measurements were also utilised. The data covers the bedrock at Olkiluoto to a depth of 1000 m. The results from groundwater chemistry, isotopes, petrography, hydrogeology of the site, geomicrobial studies, and PCA and speciation calculations were used in the evaluation of evolutionary processes at the site. The geochemical interpretation of water-rock interaction, isotope-chemical evolution and mixing of palaeo water types were approached by mass-balance calculations (NETPATH). Reaction-path calculations (EQ3/6) were used to verify the thermodynamic feasibility of the reaction models obtained. The interpretation and calculation of hydrochemical data from Olkiluoto reveals the complex nature of hydrogeochemical evolution at the site. Changes in

  15. Safety assessment for a KBS-3H spent nuclear fuel repository at Olkiluoto. Summary report

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Paul; Neall, Fiona; Snellman, Margit; Pastina, Barbara; Nordman, Henrik; Johnson, Lawrence; Hjerpe, Thomas

    2008-03-15

    The KBS-3 method, based on multiple barriers, is the proposed spent fuel disposal method both in Sweden and Finland. KBS-3H and KBS-3V are the two design alternatives of the KBS-3 spent fuel disposal method. Posiva and SKB have conducted a joint research, demonstration and development (RDandD) programme in 2002-2007 with the overall aim of establishing whether KBS-3H represents a feasible alternative to the reference alternative KBS-3V. The overall objectives of the present phase covering the period 2004-2007 have been to demonstrate that the horizontal deposition alternative is technically feasible and to demonstrate that it fulfils the same long-term safety requirements as KBS-3V. The safety studies conducted as part of this programme include a safety assessment of a preliminary design of a KBS-3H repository for spent nuclear fuel located about 400 m underground at the Olkiluoto site, which is the proposed site for a spent fuel repository in Finland. This safety assessment is summarised in the present report. The scientific basis of the safety assessment includes around 30 years of scientific RandD and technical development in the Swedish and Finnish KBS-3V programmes. Much of this scientific basis is directly applicable to KBS-3H. This has allowed the KBS-3H safety studies to focus on those issues that are unique to this design alternative, identified in a systematic 'difference analysis' of KBS-3H and KBS-3V. This difference analysis has shown that the key differences in the evolution and performance of KBS-3H and KBS-3V relate mainly to the engineered barrier system and to the impact of local variations in the rate of groundwater inflow on buffer saturation along the KBS-3H deposition drifts. No features or processes specific to KBS-3H have been identified that could lead to a loss or substantial degradation of the safety functions of the engineered barriers over a million year time frame. Radionuclide release from the repository near field in the

  16. Core drilling of deep drillhole OL-KR57 at Olkiluoto in Eurajoki 2011-2012

    Energy Technology Data Exchange (ETDEWEB)

    Toropainen, V. [Suomen Malmi Oy, Espoo (Finland)

    2012-07-15

    As a part of the confirming site investigations at Olkiluoto, Suomen Malmi Oy (Smoy) core drilled 401.71 m and 45.01 m deep drillholes, OL-KR57 and OL-KR57B, at Olkiluoto in September 2011 - January 2012. The diameter of the drillholes is 75.7 mm. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the returning and drilling water were recorded. The drill rig was computer controlled and the computer recorded drilling parameters during drilling. The objective of the measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The total volumes of the used drilling, flushing and washing water were 350 m3 and 30 m3 in the drillholes OL-KR57 and OL-KR57B, respectively. The measured volumes of the returning water in the drillholes were 328 m{sup 3} and 16.8 m{sup 3}, respectively. The deviations of the drillholes were measured with the deviation measuring instruments EMS and Gyro. Uniaxial compressive strength, Young's Modulus and Poisson's ratio were measured from the core samples. The average uniaxial compressive strength was 123.9 MPa, the average Young's Modulus was 42.6 GPa and the average Poisson's ratio was 0.23. The main rock types are veined and diatexitic gneisses, mica gneiss and tonaliticgranodioritic- granitic gneiss. The average fracture frequency is 2.5 pcs/m in drillhole OL-KR57 and 3.3 pcs/m in the drillhole OL-KR57B. The average RQD values are 95.0 % and 93.0 %. Seven separate fractured zones were interpreted from OL-KR57 and three fractured zones from OL-KR57B. (orig.)

  17. Comparison of site descriptive models for Olkiluoto, Finland and Forsmark, Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Geier, J.; Bath, A.; Stephansson, O.; Luukkonen, A.

    2012-08-15

    The proposed high-level radioactive waste repository sites at Olkiluoto and Forsmark share broadly similar geologic histories and regional settings. Despite differences in lithology, rock strength and patterns of brittle deformation, the sites show similarities in terms of hydrogeochemistry and hydrogeology. These similarities reflect a dominating influence of saline and brackish water intrusion during inundation by the postglacial Littorina Sea and Baltic Sea, followed by exposure to meteoric waters following postglacial uplift and transition to a Baltic coastal setting. Both sites also contain deep bedrock saline groundwater, though this is more evident at Olkiluoto than at Forsmark. A comparative study of site descriptive models for the two sites identifies the following key differences that could potentially impact safety of a repository: (1) Redox controls, buffering and biogeochemistry at proposed repository depths; (2) Salinity gradients at and below proposed repository depths; (3) Methane concentrations at and below proposed repository depths; (4) Depths to which glacial water and Littorina water penetrated; (5) Cation hydrogeochemistry and water-rock reaction; (6) Pore water compositions in rock matrix; (7) Rock fabric, secondary minerals and alteration with respect to radionuclide retention; (8) Brittle deformation fabric differences on multiple scales that affect vertical hydraulic conductivity; (9) Differences in apparent frequency of encountering water-conducting networks at proposed repository depths; (10) Shallow bedrock hydraulic properties; (11) Unique intrusive or dissolution features; (12) Connectivity of site-scale models to regional-scale features; (13) Mesoproterozoic rocks in vicinity and possibilities for human-intrusion scenarios; (14) Rock stresses and bedrock strength and deformability at proposed repository depths; (15) Thermal anisotropy. These differences are all potentially significant to safety functions, but none are so severe that

  18. Safety assessment of spent fuel disposal in Haestholmen, Kivetty, Olkiluoto and Romuvaara - TILA-99

    Energy Technology Data Exchange (ETDEWEB)

    Vieno, T.; Nordman, H. [VTT Energy (Finland)

    1999-03-01

    The spent fuel from the Finnish nuclear power plants is planned to be disposed of in copper-iron canisters emplaced in a KBS-3 type repository constructed at a depth of about 500 metres at one of the four candidate sites investigated. The disposal concept aims at long-term isolation of the spent fuel assemblies from the biosphere and even from the geosphere. The evaluation of the normal evolution of the disposal system accords with the conclusions of the previous Finnish, Swedish and Canadian safety assessments of similar disposal concepts. Subject to the influence of the expected, normal evolution of the repository, initially intact copper-iron canisters will most likely preserve their integrity for more than one million years at any of the candidate sites. Consequently, the best-estimate assessment is that there never will be any significant releases of radionuclides from the repository into the geosphere. Consequences of potential canister failures have been evaluated using conservative assumptions, models and data. The results show that at any of the sites a large number of canisters could be assumed to be initially defective or to `disappear` simultaneously after some time without that the proposed constraints for release rates into the biosphere or dose rates were exceeded. In most cases this conclusion is valid for all canisters failing simultaneously, even if rather pessimistic flow and transport data is used. In the sensitivity and `what if` analyses where very high flow rates of saline groundwater are assumed, highest release and dose rates are caused by weakly-sorbing cations Sr-90 and Ra-226. The most important differences between the sites are related to the coastal location and brackish/saline groundwater of Haestholmen and Olkiluoto, and on the other hand to the inland location and fresh groundwater of Kivetty and Romuvaara. Because of the ongoing postglacial land uplift at the coast of the Baltic Sea, Olkiluoto and Haestholmen, too, may become

  19. Distribution coefficients of different soil types at Olkiluoto repository site and its surroundings, southwestern Finland

    Energy Technology Data Exchange (ETDEWEB)

    Lahdenperae, Anne-Maj [Saanio and Riekkola Oy, Laulukuja 4, FI-00420 Helsinki (Finland); Ikonen, Ari T.K. [Environmental Research and Assessment EnviroCase, Ltd., Hallituskatu 1 D 4, 28100 Pori (Finland)

    2014-07-01

    In Finland, the Olkiluoto Island on the western coast has been selected as a repository site for the spent nuclear fuel. Due to shallow sea areas around the island, the post-glacial crustal rebound (around 6 mm/y) is changing the landscape significantly; during the next thousands of years new soil types are emerging, the present bays will narrow and form future lakes and mires assumedly similar to those farther inland at present. The effects of terrain development are important in long-term safety assessments for the repository, especially in the biosphere assessments addressing radiation exposure of people and biota in scenarios of radionuclide releases. 'In situ' distribution coefficients, K{sub d} values are used to indicate the relevant mobility of radionuclides of concern from nuclear waste. These radionuclides have very long half-lives and long interaction times with soils, ranging from centuries to millennia. By measuring the desorption K{sub d} values of the indigenous stable elements (Ag, Cl, Cs, I, Mo, Nb, Ni, Se and Sr) from field moist samples are a valid description of slow retention processes. The 'in situ' K{sub d} desorption values are calculated for humus, peat and different mineral soil samples taken from the Olkiluoto Island and the Reference Area used as an analogue of the future terrain. The solids are extracted alternatively by HNO{sub 3}-HF and NH{sub 4}Ac (pH 4.5). The K{sub d} values are highly dependent on environmental factors, including but not limited to pH, soil type, soil horizon, soil body, texture, element chemical form, organic matter, carbon content and biological activity. This is discussed in the contribution; e.g., for several elements pH and K{sub d} values correlate - the finer the soil or sediment, the higher the K{sub d} values - and humus and peat samples have a clear correlation with the organic matter and carbon contents. The contribution also compares the 'in situ' K{sub d} values to

  20. Active Microbial Communities Inhabit Sulphate-Methane Interphase in Deep Bedrock Fracture Fluids in Olkiluoto, Finland

    Directory of Open Access Journals (Sweden)

    Malin Bomberg

    2015-01-01

    Full Text Available Active microbial communities of deep crystalline bedrock fracture water were investigated from seven different boreholes in Olkiluoto (Western Finland using bacterial and archaeal 16S rRNA, dsrB, and mcrA gene transcript targeted 454 pyrosequencing. Over a depth range of 296–798 m below ground surface the microbial communities changed according to depth, salinity gradient, and sulphate and methane concentrations. The highest bacterial diversity was observed in the sulphate-methane mixing zone (SMMZ at 250–350 m depth, whereas archaeal diversity was highest in the lowest boundaries of the SMMZ. Sulphide-oxidizing ε-proteobacteria (Sulfurimonas sp. dominated in the SMMZ and γ-proteobacteria (Pseudomonas spp. below the SMMZ. The active archaeal communities consisted mostly of ANME-2D and Thermoplasmatales groups, although Methermicoccaceae, Methanobacteriaceae, and Thermoplasmatales (SAGMEG, TMG were more common at 415–559 m depth. Typical indicator microorganisms for sulphate-methane transition zones in marine sediments, such as ANME-1 archaea, α-, β- and δ-proteobacteria, JS1, Actinomycetes, Planctomycetes, Chloroflexi, and MBGB Crenarchaeota were detected at specific depths. DsrB genes were most numerous and most actively transcribed in the SMMZ while the mcrA gene concentration was highest in the deep methane rich groundwater. Our results demonstrate that active and highly diverse but sparse and stratified microbial communities inhabit the Fennoscandian deep bedrock ecosystems.

  1. Summary of overburden studies at Olkiluoto with an emphasis on geosphere-biosphere interface

    Energy Technology Data Exchange (ETDEWEB)

    Lahdenpera, A.-M.; Palmen, J.; Hella, P. [JP-Fintact Oy, Vantaa (Finland)

    2005-03-15

    The aim of this work is to synthesize the existing geotechnical, geochemical, mineralogical and hydraulic data from the overburden at the Olkiluoto site. The data has been collected in different studies as a part of the characterisation program for the disposal of spent nuclear fuel mainly during 1998-2004. Soil and peat samples from open test pits at various depths have been taken and analysed. The extent of the analyses programme has varied between the sampling. Quaternary deposits in the study area were studied in 13 soils test pits dug by excavator and four peat test cores. Standard procedures were applied in logging physical properties. Two extractions were used to emulate different environmental conditions in soils. Following determinations and chemical analyses were carried out: pH, water content, organic matter, anions (Cl, F, NO{sub 3} and SO{sub 4}) and metals (Al, Ca, Cs, Fe, K, Mg, Na, U and Sr). In addition, Summary tables most of the available physicochemical data from soil and peat samples were prepared. The hydraulic conductivity in overburden has been measured in the groundwater observation tubes (PVP-holes). The measurements were conducted by using the so called slug-test technique. The fluctuation of water table, dry top layer vs. ground surface elevation and dry top layer thickness vs. overburden thickness in shallow boreholes and uppermost levels of multi level piezometers (EP-holes) are also presented. (orig.)

  2. Distribution coefficients of caesium, chlorine, iodine, niobium, selenium and technetium on Olkiluoto soils

    Energy Technology Data Exchange (ETDEWEB)

    Soederlund, M.; Lusa, M.; Virtanen, S.; Vaelimaa, I.; Hakanen, M.; Lehto, J. [Univ. of Helsinki, Lab. of Radiochemistry (Finland); Lahdenperae, A.-M. [Saanio and Riekkola Oy, Helsinki (Finland)

    2014-02-15

    Retention of caesium, chlorine, iodine, niobium, selenium and technetium was investigated on soil samples from Olkiluoto using laboratory batch sorption experiments. Distribution coefficients were measured for both dried and sieved and untreated (wet, not sieved) mineral soil and humus in aerobic and anaerobic conditions. Mineralogical composition of the samples was determined by XRD-analysis. Caesium was sorbed efficiently on mineral soil samples and less efficiently on humus. Sorption decreased with decreasing cation exchange capacity and clay fraction content. The effect of competing cations decreased in the order Cs{sup +}>NH{sub 4}{sup +}>K{sup +}>Ca{sup 2+}>Na{sup +}. Chlorine was not retained by mineral soil samples, and the sorption was weak on humus. The sorption of iodine was the strongest on humus and the weakest on the untreated mineral soil samples in the anaerobic conditions. In the mineral soil samples, the sorption decreased with decreasing organic matter content and increasing pH. The retention of niobium on soil samples was the most efficient among the studied elements. The retention was high regardless of the aeration conditions. Sorption on humus was smaller. Selenium was retained efficiently on humus. Sorption on mineral soil samples was stronger in aerobic conditions. Sorption increased with time. Technetium was sorbed well on humus and anaerobic, untreated mineral soil samples. Sorption increased with increasing organic matter content and decreasing redox potential. The results from the sorption experiments are used in the site specific radionuclide migration modelling. (orig.)

  3. Active Microbial Communities Inhabit Sulphate-Methane Interphase in Deep Bedrock Fracture Fluids in Olkiluoto, Finland

    Science.gov (United States)

    Bomberg, Malin; Nyyssönen, Mari; Pitkänen, Petteri; Lehtinen, Anne; Itävaara, Merja

    2015-01-01

    Active microbial communities of deep crystalline bedrock fracture water were investigated from seven different boreholes in Olkiluoto (Western Finland) using bacterial and archaeal 16S rRNA, dsrB, and mcrA gene transcript targeted 454 pyrosequencing. Over a depth range of 296–798 m below ground surface the microbial communities changed according to depth, salinity gradient, and sulphate and methane concentrations. The highest bacterial diversity was observed in the sulphate-methane mixing zone (SMMZ) at 250–350 m depth, whereas archaeal diversity was highest in the lowest boundaries of the SMMZ. Sulphide-oxidizing ε-proteobacteria (Sulfurimonas sp.) dominated in the SMMZ and γ-proteobacteria (Pseudomonas spp.) below the SMMZ. The active archaeal communities consisted mostly of ANME-2D and Thermoplasmatales groups, although Methermicoccaceae, Methanobacteriaceae, and Thermoplasmatales (SAGMEG, TMG) were more common at 415–559 m depth. Typical indicator microorganisms for sulphate-methane transition zones in marine sediments, such as ANME-1 archaea, α-, β- and δ-proteobacteria, JS1, Actinomycetes, Planctomycetes, Chloroflexi, and MBGB Crenarchaeota were detected at specific depths. DsrB genes were most numerous and most actively transcribed in the SMMZ while the mcrA gene concentration was highest in the deep methane rich groundwater. Our results demonstrate that active and highly diverse but sparse and stratified microbial communities inhabit the Fennoscandian deep bedrock ecosystems. PMID:26425566

  4. Characterisation of matrix pore water at the Olkiluoto investigation site, Finland

    Energy Technology Data Exchange (ETDEWEB)

    Eichinger, F.L.

    2006-12-15

    Pore water that resides in the interconnected pore space between minerals and along grain boundaries in crystalline rocks of low permeability has been extracted successfully by tested laboratory out-diffusion methods using drillcore samples from borehole KR 39 located in the Olkiluoto subarea. The obtained experiment solutions have been characterised chemically and isotopically and related to the in situ pore water composition of the rock. In addition, the method of extraction, together with interfaced measurements of interconnected porosity, provided the opportunity to derive diffusion coefficient values of potential use in predicting future rates of solute transport. Because of the very small volumes of pore water extracted, and the possibility of rock stress release occurring during drilling which might: (a) lead to contamination by drilling fluid, (b) affect the derivation of rock porosity values, and (c) result in input of fluids from ruptured fluid inclusions, great care was taken to avoid such problems or, at least further understand the repercussions. Interpretations of the extracted pore waters are supported by investigations of the rock mineralogy, mineral chemistry, whole-rock chemistry, mineral fluid inclusions, and crush-leach experiments. (orig.)

  5. Game statistics for the Island of Olkiluoto in 2011-2012

    Energy Technology Data Exchange (ETDEWEB)

    Niemi, M.; Nieminen, M. [Faunatica Oy, Espoo (Finland); Jussila, I. [Turku Univ. (Finland)

    2012-11-15

    The game statistics for the island of Olkiluoto were updated in the summer 2012 and compared with earlier statistics. Population size estimates are based on interviews of the local hunters. No moose or deer inventories were made in the winter 2011-2012. The moose population has been decreasing slightly during the past ten years. The increasing lynx population has decreasing effect on small ungulate (white-tailed deer and roe deer) populations. The number of hunted mountain hares and European brown hares decreased when comparing the previous year. In addition, the number of hunted raccoon dogs was about 50 per cent lower than in the year 2010. Altogether 27 waterfowls were hunted in 2011. The population of mountain hare is abundant, despite that there were lynx living on the eastern part of island during the winter 2011. Based on track observations, there are pine martens living on the area as well. In addition, there were some observations of wolves visiting on the area. The winter 2011-2012 was milder than the previous one, and it seemed that young swans wintering on the area survived better that in the previous winter. (orig.)

  6. Geophysical logging and imaging of shallow drillholes ONK-PP262 and ONK-274 at Olkiluoto in 2010

    Energy Technology Data Exchange (ETDEWEB)

    Tarvainen, A.-M. [Suomen Malmi Oy, Espoo (Finland)

    2011-11-15

    Suomen Malmi Oy conducted geophysical drillhole logging as well as optical and acoustic imaging of shallow drillholes ONK-PP262 and ONK-PP274 at ONKALO in the investigation niche ONK-TKU-4 (Hydco) in May and in December 2010. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The assignment included the field work and data processing. The report describes field operation, equipment as well as processing procedures and shows the obtained results and an analysis of their quality in the appendices. The raw and processed data are delivered digitally in WellCAD, PDF and Excel format. (orig.)

  7. The estimation of future surface water bodies at Olkiluoto area based on statistical terrain and land uplift models

    Energy Technology Data Exchange (ETDEWEB)

    Pohjola, J.; Turunen, J.; Lipping, T. [Tampere Univ. of Technology (Finland); Ikonen, A.

    2014-03-15

    In this working report the modelling effort of future landscape development and surface water body formation at the modelling area in the vicinity of the Olkiluoto Island is presented. Estimation of the features of future surface water bodies is based on probabilistic terrain and land uplift models presented in previous working reports. The estimation is done using a GIS-based toolbox called UNTAMO. The future surface water bodies are estimated in 10 000 years' time span with 1000 years' intervals for the safety assessment of disposal of spent nuclear fuel at the Olkiluoto site. In the report a brief overview on the techniques used for probabilistic terrain modelling, land uplift modelling and hydrological modelling are presented first. The latter part of the report describes the results of the modelling effort. The main features of the future landscape - the four lakes forming in the vicinity of the Olkiluoto Island - are identified and the probabilistic model of the shoreline displacement is presented. The area and volume of the four lakes is modelled in a probabilistic manner. All the simulations have been performed for three scenarios two of which are based on 10 realizations of the probabilistic digital terrain model (DTM) and 10 realizations of the probabilistic land uplift model. These two scenarios differ from each other by the eustatic curve used in the land uplift model. The third scenario employs 50 realizations of the probabilistic DTM while a deterministic land uplift model, derived solely from the current land uplift rate, is used. The results indicate that the two scenarios based on the probabilistic land uplift model behave in a similar manner while the third model overestimates past and future land uplift rates. The main features of the landscape are nevertheless similar also for the third scenario. Prediction results for the volumes of the future lakes indicate that a couple of highly probably lake formation scenarios can be identified

  8. Geophysical borehole logging of the boreholes KR23 extension, KR29 and KR29b at Olkiluoto 2004

    Energy Technology Data Exchange (ETDEWEB)

    Lahti, M. [Suomen Malmi Oy, Espoo (Finland); Heikkinen, E. [JP-Fintact Oy, Vantaa (Finland)

    2005-04-15

    Suomen Malmi Oy conducted geophysical borehole logging of the boreholes KR23 extension, KR25b, KR29 and KR29b at the Olkiluoto site in Eurajoki during October 2004. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The assignment included the field work and processing of the acoustic data. The report describes the field operation, equipment as well as processing procedures and shows the obtained results and their quality in the appendices. The raw and processed data are delivered digitally in WellCAD and Excel format. (orig.)

  9. Studies of quaternary deposits in Olkiluoto in 2004; Maaperaetutkimukset tutkimuskaivannoissa TKB ja TK9 Olkiluodossa 2004

    Energy Technology Data Exchange (ETDEWEB)

    Huhta, P. [Geological Survey of Finland, Espoo (Finland)

    2005-04-15

    The study sections (trenches) TK 8 and TK 9 in Olkiluoto were studied according to the contract in autumn 2004. The investigations were carried out in three phases as the excavation progressed. Samples for grain size determinations were taken from vertical profiles, placed 25 m apart along the trench, with the profiles extending from the soil surface down to bedrock or, if the bedrock was covered with water, to the water table. Between 6 and 7 kg of sediment was taken in a bucket with a shovel and placed in plastic bags for transport to the laboratory. The samples were first dried in the laboratory after which they were sieved. In addition, grain size distribution of the < 63 {mu}m fraction was analyzed with the Micromeritics 5000 ET Sedigraph. Sedimentological observations of the sampling profiles were documented in field by drawing (on a field observation form) and the profiles were photographed using a digital camera. In addition, the excavated sections were photographed along their whole length. The length of the TK 8 trench is approximately 730 m and 30 profiles were sampled from it. The height of the profiles varied from 6 m to 0.8 m with an average of 2.6 m. The till in the trench TK 8 is classified as having a normal amount of cobbles and boulders with the size of the larger clasts varying from 6 to 60 cm. The clasts are normally rounded or sub-angular. Both the size and number of cobbles increases with depth, as does their angularity. In places the till is overlain by postglacial clays/silts and littoral sands. With the exception of one sample, all samples from the TK 8 section can be classified as sandy tills based on the d50 grain size. According to the guidelines for mapping of Quatemary deposits one third of the samples is classified as fine-grained tills. This is because of the high percentages of silt and clay size particles that affect the frost heaving properties of the tills as well as their suitability for construction. A till is considered fine

  10. Isotopic Evidence for Microbial Activity in Crystalline Bedrock Fractures - a Case Study from Olkiluoto, SW Finland

    Science.gov (United States)

    Sahlstedt, E. K.; Karhu, J.; Pitkänen, P.

    2015-12-01

    Changes in the geochemical environment in crystalline bedrock fractures were investigated using the stable isotopes of C, O and S in fracture filling minerals as tracers. Of special interest were the possible changes which may occur in the subsurface at low temperatures. Especially, the influence of microbial activity was recognized as a catalyst for inducing changes in the geochemical environment. The study site is the Olkiluoto island located on the western coast of Finland, planned to host a geological repository for nuclear waste. Fracture surfaces were investigated to recognize the latest mineralizations at the site. These fillings were comprised of thin plates or small euhedral crystals of calcite and pyrite. The carbon and sulfur isotope compositions of calcite and pyrite were measured from bulk material by conventional IRMS, and in situ by secondary ion mass spectrometry. A notable feature of the late-stage fillings was high variabilities in the δ13C values of calcite and the δ34S values of pyrite, which ranged from -53.8 ‰ to +31.6 ‰ and from -50.4 ‰ to +77.7 ‰, respectively. Based on the isotopic compositions of the fillings, several features in the past hydrogeochemical environment could be recognized. The isotopic composition of the fracture fillings indicate an environment which was stratified with respect to depth. Characteristic features include bacterial sulfate reduction (BSR) occurring at depths 50 m. It appears that methanic conditions were replaced by sulfate reduction at depths >50 m likely due to infiltration of SO42--rich brackish waters. Sulfate reducing bacteria used mainly surface derived organic carbon as electron donors. Some indication of minor methanotrophic activity was recognized in anomalously low δ13C values of calcite, down to -53.8 ‰, at the depth range of 34-54 m. This methanotrophic activity may have been related to bacteria using CH4 as an electron donor in BSR.

  11. Game statistics for the island of Olkiluoto in 2013-2014

    Energy Technology Data Exchange (ETDEWEB)

    Niemi, M.; Nieminen, M. [Faunatica Oy, Espoo (Finland)

    2015-05-15

    The game statistics for the island of Olkiluoto were updated in the summer 2014 and compared with earlier statistics. In addition, the estimated biomass of hunted animals was calculated. The reported game bag and population size estimates are based on the annual action report of local hunting club (Olkiluodon Metsaestysseura ry) and interviews of hunting club's secretary. No moose or deer inventories were made in the winter 2013-2014. The moose population has been a slightly increasing when comparing the previous year; there were 4-6 individuals on the island after hunting season. The number of moose varies because they tend to move between the island and mainland. Winter 2013-2014 was relatively easy for white-tailed deer and roe deer but the predation caused by lynxes inhibits the increase of populations. However, the current amount of lynxes on the island is unknown because the lack of snow in the winter 2013-2014. In the summer of 2014, there were several lynx observations. The number of hunted raccoon dogs was almost four times as large as in the previous year; altogether 26 individuals were killed. There were no noticeable changes in the number of other hunted small or medium-sized predators. American minks were not killed at all. The total number of hunted hares decreased from eleven to seven. Once again, mallard was the most common hunted bird species followed by hooded crow. Other bird species hunted were wood pigeon, herring gull, hazel grouse, wigeon, teal and common pochard. The total biomass hunted was approximately 1 225 kilos (1 170 for mammals and 55 for birds) which was 305 kilos more than in the previous year. The biomass destined to human consumption (i.e. game meat) was approximately 415 kilos (400 kilos for mammals, 15 for birds). (orig.)

  12. Mineralogical study on quaternary soils of the Olkiluoto investigation trench OL-TK19

    Energy Technology Data Exchange (ETDEWEB)

    Lukkari, S.; Marmo, J. [Geological Survey of Finland, Espoo (Finland)

    2014-07-15

    Six till samples representing three vertical profiles in a research trench OL TK19 from Olkiluoto were studied for their mineralogy. The client, Posiva Oy, was interested especially in carbonates and sulphides. The study is based on size and density classified subsamples. Mineral distributions were determined by a Scanning Electron Microscope (SEM) equipped with an energy dispersive X-ray spectrometer (EDS), using the INCA FEATURE phase detection and classification software. Lithologies within the cobble fraction are also measured. The study revealed unhomogeneity in the sample material. Sample TK 19/2 POH is rich in calcareous sedimentary rocks and older till compared to the other samples. Three main carbonate-bearing sedimentary rock types are: limestone, carbonate cemented quartz feldspar rock, and quartz graywacke, containing clasts of the carbonate cemented quartz feldspar rock. The contents of heavy minerals (0.1-1.2%) and semi heavy minerals (1.3-3.3%) are low in every sample. Carbonate concentrates of the semi heavy mineral separates are low (0.04-0.57 %). Sulfide is predominately pyrite (1.3-8.6%). Pyrite grains have commonly goethite crusts, which are ubiquitous in the surface samples. Both sulphide and carbonate occurs as liberated grains and as fine grained matrix, enveloping other mineral grains. Phosphorites and phosphorous rock fragments are also common in the till samples. The mode of occurrence of phosphate resembles that of carbonate and sulphides that makes the quantification of these buffer minerals impossible. Sedimentary rocks are interpreted to have been derived from the sedimentary rock pile preserved under the Gulf of Bothnia. (orig.)

  13. Revealing the unexplored fungal communities in deep groundwater of crystalline bedrock fracture zones in Olkiluoto, Finland.

    Science.gov (United States)

    Sohlberg, Elina; Bomberg, Malin; Miettinen, Hanna; Nyyssönen, Mari; Salavirta, Heikki; Vikman, Minna; Itävaara, Merja

    2015-01-01

    The diversity and functional role of fungi, one of the ecologically most important groups of eukaryotic microorganisms, remains largely unknown in deep biosphere environments. In this study we investigated fungal communities in packer-isolated bedrock fractures in Olkiluoto, Finland at depths ranging from 296 to 798 m below surface level. DNA- and cDNA-based high-throughput amplicon sequencing analysis of the fungal internal transcribed spacer (ITS) gene markers was used to examine the total fungal diversity and to identify the active members in deep fracture zones at different depths. Results showed that fungi were present in fracture zones at all depths and fungal diversity was higher than expected. Most of the observed fungal sequences belonged to the phylum Ascomycota. Phyla Basidiomycota and Chytridiomycota were only represented as a minor part of the fungal community. Dominating fungal classes in the deep bedrock aquifers were Sordariomycetes, Eurotiomycetes, and Dothideomycetes from the Ascomycota phylum and classes Microbotryomycetes and Tremellomycetes from the Basidiomycota phylum, which are the most frequently detected fungal taxa reported also from deep sea environments. In addition some fungal sequences represented potentially novel fungal species. Active fungi were detected in most of the fracture zones, which proves that fungi are able to maintain cellular activity in these oligotrophic conditions. Possible roles of fungi and their origin in deep bedrock groundwater can only be speculated in the light of current knowledge but some species may be specifically adapted to deep subsurface environment and may play important roles in the utilization and recycling of nutrients and thus sustaining the deep subsurface microbial community.

  14. Revealing the unexplored fungal communities in deep groundwater of crystalline bedrock fracture zones in Olkiluoto, Finland

    Directory of Open Access Journals (Sweden)

    Elina eSohlberg

    2015-06-01

    Full Text Available The diversity and functional role of fungi, one of the ecologically most important groups of eukaryotic microorganisms, remains largely unknown in deep biosphere environments. In this study we investigated fungal communities in packer-isolated bedrock fractures in Olkiluoto, Finland at depths ranging from 296 m to 798 m below surface level. DNA- and cDNA-based high-throughput amplicon sequencing analysis of the fungal internal transcribed spacer (ITS gene markers was used to examine the total fungal diversity and to identify the active members in deep fracture zones at different depths. Results showed that fungi were present in fracture zones at all depths and fungal diversity was higher than expected. Most of the observed fungal sequences belonged to the phylum Ascomycota. Phyla Basidiomycota and Chytridiomycota were only represented as a minor part of the fungal community. Dominating fungal classes in the deep bedrock aquifers were Sordariomycetes, Eurotiomycetes and Dothideomycetes from the Ascomycota phylum and classes Microbotryomycetes and Tremellomycetes from the Basidiomycota phylum, which are the most frequently detected fungal taxa reported also from deep sea environments. In addition some fungal sequences represented potentially novel fungal species. Active fungi were detected in most of the fracture zones, which proves that fungi are able to maintain cellular activity in these oligotrophic conditions. Possible roles of fungi and their origin in deep bedrock groundwater can only be speculated in the light of current knowledge but some species may be specifically adapted to deep subsurface environment and may play important roles in the utilization and recycling of nutrients and thus sustaining the deep subsurface microbial community.

  15. Revealing the unexplored fungal communities in deep groundwater of crystalline bedrock fracture zones in Olkiluoto, Finland

    Science.gov (United States)

    Sohlberg, Elina; Bomberg, Malin; Miettinen, Hanna; Nyyssönen, Mari; Salavirta, Heikki; Vikman, Minna; Itävaara, Merja

    2015-01-01

    The diversity and functional role of fungi, one of the ecologically most important groups of eukaryotic microorganisms, remains largely unknown in deep biosphere environments. In this study we investigated fungal communities in packer-isolated bedrock fractures in Olkiluoto, Finland at depths ranging from 296 to 798 m below surface level. DNA- and cDNA-based high-throughput amplicon sequencing analysis of the fungal internal transcribed spacer (ITS) gene markers was used to examine the total fungal diversity and to identify the active members in deep fracture zones at different depths. Results showed that fungi were present in fracture zones at all depths and fungal diversity was higher than expected. Most of the observed fungal sequences belonged to the phylum Ascomycota. Phyla Basidiomycota and Chytridiomycota were only represented as a minor part of the fungal community. Dominating fungal classes in the deep bedrock aquifers were Sordariomycetes, Eurotiomycetes, and Dothideomycetes from the Ascomycota phylum and classes Microbotryomycetes and Tremellomycetes from the Basidiomycota phylum, which are the most frequently detected fungal taxa reported also from deep sea environments. In addition some fungal sequences represented potentially novel fungal species. Active fungi were detected in most of the fracture zones, which proves that fungi are able to maintain cellular activity in these oligotrophic conditions. Possible roles of fungi and their origin in deep bedrock groundwater can only be speculated in the light of current knowledge but some species may be specifically adapted to deep subsurface environment and may play important roles in the utilization and recycling of nutrients and thus sustaining the deep subsurface microbial community. PMID:26106376

  16. Short tunnels.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1965-01-01

    Before dealing with the question of lighting short tunnels, it is necessary define what is meant by a tunnel and when it should be called 'short'. Confined to motorized road traffic the following is the most apt definition of a tunnel: every form of roofing-over a road section, irrespective of it le

  17. The Site Selected. The Local Decision-Making Regarding the Siting of the Spent Nuclear Fuel Repository in Olkiluoto

    Energy Technology Data Exchange (ETDEWEB)

    Kojo, Matti [Univ. of Tampere (Finland). Dept. of Political Science and International Relations

    2006-09-15

    In May 1999 Posiva, the company responsible for the final disposal of spent nuclear fuel in Finland, suggested that the Finnish Government considers only Olkiluoto in Eurajoki in its application of a decision in principle to be a final disposal site. In January 2000 the municipal council of Eurajoki made a positive statement on the decision in principle. The Government made the decision in principle in Dec 2000, and the Parliament ratified the decision in May 2001. The paper is focused on the decision making of Eurajoki municipality regarding the siting of the spent nuclear fuel repository. The paper shows how the interaction between the representatives of the candidate municipality and the nuclear energy industry was the crucial factor in the decision-making. Eurajoki serves as an example, in where the parties reached an agreement of the compensations for the final disposal repository. The negotiations between the Eurajoki municipality and the nuclear energy industry in reaching a positive decision are analysed from the beginning of the 1980s. The main emphasis is however on the years 1996-99, when the nuclear energy industry negotiated with the municipality on the compensation for the final disposal repository. The loss of income was an important reason why some of the councillors of Eurajoki were interested in having the final disposal repository in Olkiluoto. The industry's problem on the other hand was to safeguard the final disposal site. From the TVO's angle Olkiluoto was a potential final disposal site for example for its limited need for transport and for the existing infrastructure. The company used the financial benefits of the project as its trump card. The attitude of Eurajoki municipality to the final disposal of spent nuclear fuel turned positive with the Olkiluoto vision in December 1998, when still five years earlier the municipal council was prepared to act and prevent the final disposal. The future image presented by the municipality

  18. Seismic monitoring experiment of raise boring in 2014

    Energy Technology Data Exchange (ETDEWEB)

    Saari, J.; Malm, M. [AaF-Consult Oy, Espoo (Finland)

    2015-01-15

    In Olkiluoto, Posiva Oy has operated a local seismic network since February 2002. The purpose of the microearthquake measurements at Olkiluoto is to improve understanding of the structure, behaviour and long term stability of the bedrock. The studies include both tectonic and excavation-induced microearthquakes. An additional task of monitoring is related to safeguarding of ONKALO. The possibility to excavate an illegal access to ONKALO has been concerned when the safeguards are discussed. Therefore all recorded explosions in the Olkiluoto area and in ONKALO are located. If a concentration of explosions is observed, the origin of that is found out. Also a concept of hidden illegal explosions, detonated at the same time as the real excavation blasts, has been examined. According to the experience gained in Olkiluoto, it can be concluded that, as long the seismic network is in operation and the results are analysed by a skilled person, it is practically impossible to do illegal undetected excavation by blasting within the Olkiluoto seismic network area. In this report a possibility of seismic monitoring of undeclared excavation done by tunnel boring machine (TBM) has been investigated. In the earlier investigations the instruments were at the ground surface and the sensors were triaxial short period (1 Hz) geophones or broadband geophones. The characteristics (frequency content, polarity and amplitude) of the continuous seismic vibration generated by TMB were studied. The onset time of the seismic signal were not distinguished. Altogether 16 new 10 kHz accelerometers were installed in boreholes inside ONKALO March 2012. The sensors comprised a new subnetwork that monitored the raise boring of two shafts done 2014, from the level -455 m to the level -290 m. The aim was to record the seismic signal generated when the drill bit hits the rock at the moment the tunnel boring begins. Altogether 113 seismic signals generated by the drill bit were located during the

  19. Operational safety analysis of the Olkiluoto encapsulation plant and disposal facility; Olkiluodon kapselointi- ja loppusijoituslaitoksen kaeyttoeturvallisuusanalyysi

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, J.; Suolanen, V. [VTT Technical Research Centre of Finland, Espoo (Finland)

    2012-11-15

    Radiation doses for workers of the facility, for inhabitants in the environment and for terrestrial ecosystem possibly caused by the encapsulation and disposal facilities to be built at Olkiluoto during its operation were considered in the study. The study covers both the normal operation of the plant and some hypothetical incidents and accidents. Release through the ventilation stack is assumed to be filtered both in normal operation and in hypothetical abnormal fault and accident cases. In addition the results for unfiltered releases are also presented. This research is limited to the deterministic analysis. During about 30 operation years of our four nuclear power plant units there have been found 58 broken fuel pins. Roughly estimating there has been one fuel leakage per year in a facility (includes two units). Based on this and adopting a conservative approach, it is estimated that one fuel pin per year could leak in normal operation during encapsulation process. The release magnitude in incidents and accidents is based on the event chains, which lead to loss of fuel pin tightness followed by a discharge of radionuclides into the handling space and to some degree to the atmosphere through the ventilation stack equipped with redundant filters. The most exposed group of inhabitants is conservatively assumed to live at the distance of 200 meters from the encapsulation and disposal plant and it will receive the largest doses in most dispersion conditions. The dose value to a member of the most exposed group was calculated on the basis of the weather data in such a way that greater dose than obtained here is caused only in 0.5 percent of dispersion conditions. The results obtained indicate that during normal operation the doses to workers remain small and the dose to the member of the most exposed group is less than 0.001 mSv per year. In the case of hypothetical fault and accident releases the offsite doses do not exceed either the limit values set by the safety

  20. Geophysical borehole logging and optical imaging of the boreholes KR34, KR35 and KR36, at Olkiluoto 2005

    Energy Technology Data Exchange (ETDEWEB)

    Majapuro, J. [Suomen Malmi Oy, Espoo (Finland)

    2005-09-15

    Suomen Malmi Oy conducted geophysical borehole logging and optical imaging surveys of the boreholes KR34, KR35 and KR36 at the Olkiluoto site in Eurajoki during May - June 2005. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The methods applied are magnetic susceptibility, natural gamma radiation, gamma-gamma density, single point resistance, Wenner-resistivity, borehole radar, full waveform sonic and optical imaging. The assignment included the field work of all surveys, interpretation and processing of the acoustic and borehole radar data. The report describes the field operation, equipment as well as processing procedures and shows the obtained results and their quality in the appendices. The raw and processed data are delivered digitally in WellCAD and Excel format. (orig.)

  1. Impact of corrosion-derived iron on the bentonite buffer within the KBS-3H disposal concept. The Olkiluoto site as case study

    Energy Technology Data Exchange (ETDEWEB)

    Wersin, Paul (National Cooperative for the Disposal of Radioactive Waste, Nagra, Wettingen (Switzerland)); Birgersson, Martin; Olsson, Siv; Karnland, Ola (Clay Technology AB, Lund (Sweden)); Snellman, Margit (Saanio and Riekkola Oy, Helsinki (Finland))

    2008-05-15

    montmorillonite transformation or cementation processes. A preliminary study yielded ambiguous results. The data suggested that an increase in hydraulic conductivity but no effect on swelling properties had occurred, which might be due to some cementation process. It is important to note that, at least to our knowledge, natural analogue examples displaying typical cementation features under anoxic conditions are lacking. This is contrary to examples from oxic conditions where iron oxides frequently form cementation products. The extent of iron-bentonite interaction in a KBS-3H repository was assessed by means of (1) a mass balance estimate and (2) reactive transport modelling. The mass balance results indicated that a maximum of 10-30% of the montmorillonite in the buffer could be converted to a non-swelling Fe(II)-rich clay if all the iron from the supercontainer steel shell reacted with the clay. In the reactive transport model, site-specific geochemical data from Olkiluoto, corrosion data, Fe(II) sorption data and thermodynamic and kinetic clay data were included in a 1D diffusion model. A number of limiting test cases was run to explore the sensitivity of the results towards uncertainties in data and model assumptions. The general conclusion from the preliminary modelling study is that the extent of the zone transformed to non-swelling material is likely to remain spatially limited (a few centimetres) for very long times. Given the proximity of the physically affected area around the supercontainer steel shell to the tunnel boundary, however the potential impacts of an altered zone consisting of corrosion products and transformed clay material need to be considered in performance assessment calculations. In order to decrease the uncertainty of the effect of the supercontainer steel shell on the buffer's stability, careful experimental studies on Fe-bentonite interaction under anoxic conditions and including measurements of physical properties should be carried out. The

  2. Impact of corrosion-derived iron on the bentonite buffer within the KBS-3H disposal concept. The Olkiluoto site as case study

    Energy Technology Data Exchange (ETDEWEB)

    Wersin, Paul (National Cooperative for the Disposal of Radioactive Waste, Nagra, Wettingen (Switzerland)); Birgersson, Martin; Olsson, Siv; Karnland, Ola (Clay Technology AB, Lund (Sweden)); Snellman, Margit (Saanio and Riekkola Oy, Helsinki (Finland))

    2008-05-15

    montmorillonite transformation or cementation processes. A preliminary study yielded ambiguous results. The data suggested that an increase in hydraulic conductivity but no effect on swelling properties had occurred, which might be due to some cementation process. It is important to note that, at least to our knowledge, natural analogue examples displaying typical cementation features under anoxic conditions are lacking. This is contrary to examples from oxic conditions where iron oxides frequently form cementation products. The extent of iron-bentonite interaction in a KBS-3H repository was assessed by means of (1) a mass balance estimate and (2) reactive transport modelling. The mass balance results indicated that a maximum of 10-30% of the montmorillonite in the buffer could be converted to a non-swelling Fe(II)-rich clay if all the iron from the supercontainer steel shell reacted with the clay. In the reactive transport model, site-specific geochemical data from Olkiluoto, corrosion data, Fe(II) sorption data and thermodynamic and kinetic clay data were included in a 1D diffusion model. A number of limiting test cases was run to explore the sensitivity of the results towards uncertainties in data and model assumptions. The general conclusion from the preliminary modelling study is that the extent of the zone transformed to non-swelling material is likely to remain spatially limited (a few centimetres) for very long times. Given the proximity of the physically affected area around the supercontainer steel shell to the tunnel boundary, however the potential impacts of an altered zone consisting of corrosion products and transformed clay material need to be considered in performance assessment calculations. In order to decrease the uncertainty of the effect of the supercontainer steel shell on the buffer's stability, careful experimental studies on Fe-bentonite interaction under anoxic conditions and including measurements of physical properties should be carried out. The

  3. Results of sampling and analysis of groundwater from multi-packered boreholes OL-KR1, OL-KR3, OL-KR5, OL-KR9, OL-KR11 and OL-KR12 at Olkiluoto, Eurajoki, in 2004

    Energy Technology Data Exchange (ETDEWEB)

    Hirvonen, H. [Teollisuuden Voima Oyj, Eurajoki (Finland); Hatanpaeae, E. [lnsinoeoeritoimisto Paavo Ristola Oy, Hollola (Finland)

    2005-12-15

    Nine groundwater samples were collected at Olkiluoto from deep multi-packered boreholes OL-KR1, OL-KR3, OL-KR5, OL-KR9, OL-KR11 and OL-KR12 between spring 2004 and the beginning of 2005. The aim of the ground water sampling was to get information for the basis of the monitoring program (OMO) during ONKALO construction. Sampling sections were mainly chosen so that the results of the chemical analyses from earlier studies could be used for comparison. This study presents the sampling methods and the results of the laboratory analyses of groundwater samples from the deep multi-packered boreholes OL-KR1 (151.2-156.8 m, 311.2-336.8 m and 524.4-528.4 m), OL-KR3 (242.6-253.2 m), OL-KR5 (277.2-284.6 m and 457.2-476.2 m), OL-KR9 (468.2-482.2 m), OL-KR11 (597.5-628.1 m) and OLKR12 (363-368 m). The analytical results of the groundwater samplings are compared to earlier analytical results. According to Davis and De Wiest's (1967) classification, the collected groundwater samples represent either the borehole water type Na-Cl (OL-KR1/T/151.2-156.8 m, OLK-R1/ T/311.2-336.8 m, OL-KR3/T/242.6-253.2 m, OL-KR5/T/277.2-284.6 m, OL-KR11/ T/597.5-628.1 m and OL-KR12/T/363-368 m) or Na-Ca-Cl (OL-KR1/T/524.4- 528.4 m, OL-KR5/T/457.2-476.2 m and OL-KR9/T/468.2-482.2 m). The groundwater samples from OL-KR1/T/151.2-156.8 m, OL-KR3/T/242.6- 253.2 m, OL-KR3/T/242.6-253.2 m, OL-KR5/T/277.2-284.2 m, OL-KR11/T/597.5-628.1 m and OL-KR12/T/363-368 m were brackish (1000 mg/L < TDS < 10000 mg/L) according to Davis's (1964) TDS classification. Other samples (OL-KR1/T/524.4-528.4 m, OL-KR5/ T/457.2-476.2 m and OL-KR9/T/468.2-482.2 m), were saline (TDS> 10000 mg/L). Comparison of analytical results of the samples to earlier results shows that some changes were seen between samplings done at the different times. Only the groundwater sampled from OL-KR1/T/311.2-336.8 m had significant changes in its chemical composition during the reference period, but also in OL-KR1/T/524.4-528.4 m, OL-KR5/ T

  4. Safety assessment for a KBS-3H spent nuclear fuel repository at Olkiluoto. Complementary evaluations of safety

    Energy Technology Data Exchange (ETDEWEB)

    Neall, Fiona; Pastina, Barbara; Snellman, Margit; Smith, Paul; Gribi, P.; Johnson, Lawrence

    2008-12-15

    The KBS-3H design is a variant of the more general KBS-3 method for the geological disposal of spent nuclear fuel in Finland and Sweden. In the KBS-3H design, multiple assemblies containing spent fuel are emplaced horizontally in parallel, approximately 300 m long, slightly inclined deposition drifts. The copper canisters, each with a surrounding layer of bentonite clay, are placed in perforated steel shells prior to deposition in the drifts; the assembly is called the 'supercontainer'. The other KBS-3 variant is the KBS-3V design, in which the copper canisters are emplaced vertically in individual deposition holes surrounded by bentonite clay but without steel supercontainer shells. SKB and Posiva have conducted a Research, Development and Demonstration programme over the period 2002-2007 with the overall aim of establishing whether KBS-3H represents a feasible alternative to KBS-3V. As part of this programme, the long-term safety of a KBS-3H repository has been assessed in the KBS-3H safety studies. In order to focus the safety studies, the Olkiluoto site in the municipality of Eurajoki, which is the proposed site for a spent fuel repository in Finland, was used as a hypothetical site for a KBS-3H repository. The present report is part of a portfolio of reports discussing the long-term safety of the KBS-3H repository. The overall outcome of the KBS-3H safety studies is documented in the summary report, 'Safety assessment for a KBS-3H repository for spent nuclear fuel at Olkiluoto'. The purpose and scope of the KBS-3H complementary evaluations of safety report is provided in Posiva's Safety Case Plan, which is based on Regulatory Guide YVL 8.4 and on international guidelines on complementary lines of argument to long-term safety that are considered an important element of a post-closure safety case for geological repositories. Complementary evaluations of safety require the use of evaluations, evidence and qualitative supporting arguments

  5. Safety assessment for a KBS-3H spent nuclear fuel repository at Olkiluoto. Process report

    Energy Technology Data Exchange (ETDEWEB)

    Gribi, Peter; Johnson, Lawrence; Suter, Daniel; Smith, Paul; Pastina, Barbara; Snellman, Margit

    2008-01-15

    The KBS-3 method, based on multiple barriers, is the proposed spent fuel disposal method both in Sweden and Finland. KBS-3H and KBS-3V are the two design alternatives of the KBS-3 spent fuel disposal method. Posiva and SKB have conducted a joint research, demonstration and development (RDandD) programme in 2002-2007 with the overall aim of establishing whether KBS-3H represents a feasible alternative to the reference alternative KBS-3V. The overall objectives of the present phase covering the period 2004-2007 have been to demonstrate that the horizontal deposition alternative is technically feasible and to demonstrate that it fulfils the same long-term safety requirements as KBS-3V. The safety studies conducted as part of this programme include a safety assessment of a preliminary design of a KBS-3H repository for spent nuclear fuel located about 400 m underground at the Olkiluoto site, which is the proposed site for a spent fuel repository in Finland. In the KBS-3H design alternative, each canister, with a surrounding layer of bentonite clay, is placed in a perforated steel cylinder prior to emplacement; the entire assembly is called the supercontainer. Several supercontainers are positioned along parallel, 100-300 m long deposition drifts, which are sealed following waste emplacement using drift end plugs. Bentonite distance blocks separate the supercontainers, one from another, along the drift. Steel compartment plugs can be used to seal off drift sections with higher inflow, thus isolating the different compartments within the drift. The present report describes the main processes potentially affecting the long-term safety of the system, covering radiation-related, thermal, hydraulic, mechanical, chemical (including microbiological) and radionuclide transport-related processes. The process descriptions deal sequentially with the main sub-systems: fuel/cavity in canister, cast iron insert and copper canister, buffer and other bentonite components, supercontainer

  6. Safety assessment for a KBS-3H spent nuclear fuel repository at Olkiluoto. Evolution report

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Paul; Johnson, Lawrence; Snellman, Margit; Pastina, Barbara; Gribi, Peter

    2008-01-15

    The KBS-3 method, based on multiple barriers, is the proposed spent fuel disposal method both in Sweden and Finland. KBS-3H and KBS-3V are the two design alternatives of the KBS-3 method. Posiva and SKB have conducted a joint research, demonstration and development (RDandD) programme in 2002-2007 with the overall aim of establishing whether KBS-3H represents a feasible alternative to the reference alternative KBS-3V. The overall objectives of the present phase covering the period 2004-2007, have been to demonstrate that the horizontal deposition alternative is technically feasible and to demonstrate that it fulfils the same long-term safety requirements as KBS-3V. The safety studies conducted as part of this programme include a safety assessment of a preliminary design of a KBS-3H repository for spent nuclear fuel located about 400 m underground at the Olkiluoto site, which is the proposed site for a spent fuel repository in Finland. In the KBS-3H design alternative, each canister, with a surrounding layer of bentonite clay, is pre-packaged in a perforated steel cylinder prior to emplacement in the deposition drift; the entire assembly is called the supercontainer. Several supercontainers are positioned along parallel, 100-300 m long deposition drifts, which are sealed following waste emplacement using drift end plugs. Bentonite distance blocks separate the supercontainers, one from another, along the drift. Steel compartment plugs can be used to seal off drift sections with higher inflow, thus isolating the different compartments within the drift. The present report describes the repository evolution in successive time frames, including key uncertainties. The description of evolution starts with the initial conditions at the time of emplacement of the first canisters. The repository evolves through an early, transient phase to a state where evolution is far slower. Particular attention is given to describing the transient phase, since this is where most of the

  7. Safety assessment for a KBS-3H spent nuclear fuel repository at Olkiluoto. Evolution report

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Paul; Johnson, Lawrence; Snellman, Margit; Pastina, Barbara; Gribi, Peter

    2008-01-15

    The KBS-3 method, based on multiple barriers, is the proposed spent fuel disposal method both in Sweden and Finland. KBS-3H and KBS-3V are the two design alternatives of the KBS-3 method. Posiva and SKB have conducted a joint research, demonstration and development (RDandD) programme in 2002-2007 with the overall aim of establishing whether KBS-3H represents a feasible alternative to the reference alternative KBS-3V. The overall objectives of the present phase covering the period 2004-2007, have been to demonstrate that the horizontal deposition alternative is technically feasible and to demonstrate that it fulfils the same long-term safety requirements as KBS-3V. The safety studies conducted as part of this programme include a safety assessment of a preliminary design of a KBS-3H repository for spent nuclear fuel located about 400 m underground at the Olkiluoto site, which is the proposed site for a spent fuel repository in Finland. In the KBS-3H design alternative, each canister, with a surrounding layer of bentonite clay, is pre-packaged in a perforated steel cylinder prior to emplacement in the deposition drift; the entire assembly is called the supercontainer. Several supercontainers are positioned along parallel, 100-300 m long deposition drifts, which are sealed following waste emplacement using drift end plugs. Bentonite distance blocks separate the supercontainers, one from another, along the drift. Steel compartment plugs can be used to seal off drift sections with higher inflow, thus isolating the different compartments within the drift. The present report describes the repository evolution in successive time frames, including key uncertainties. The description of evolution starts with the initial conditions at the time of emplacement of the first canisters. The repository evolves through an early, transient phase to a state where evolution is far slower. Particular attention is given to describing the transient phase, since this is where most of the

  8. Safety assessment for a KBS-3H spent nuclear fuel repository at Olkiluoto. Process report

    Energy Technology Data Exchange (ETDEWEB)

    Gribi, Peter; Johnson, Lawrence; Suter, Daniel; Smith, Paul; Pastina, Barbara; Snellman, Margit

    2008-01-15

    The KBS-3 method, based on multiple barriers, is the proposed spent fuel disposal method both in Sweden and Finland. KBS-3H and KBS-3V are the two design alternatives of the KBS-3 spent fuel disposal method. Posiva and SKB have conducted a joint research, demonstration and development (RDandD) programme in 2002-2007 with the overall aim of establishing whether KBS-3H represents a feasible alternative to the reference alternative KBS-3V. The overall objectives of the present phase covering the period 2004-2007 have been to demonstrate that the horizontal deposition alternative is technically feasible and to demonstrate that it fulfils the same long-term safety requirements as KBS-3V. The safety studies conducted as part of this programme include a safety assessment of a preliminary design of a KBS-3H repository for spent nuclear fuel located about 400 m underground at the Olkiluoto site, which is the proposed site for a spent fuel repository in Finland. In the KBS-3H design alternative, each canister, with a surrounding layer of bentonite clay, is placed in a perforated steel cylinder prior to emplacement; the entire assembly is called the supercontainer. Several supercontainers are positioned along parallel, 100-300 m long deposition drifts, which are sealed following waste emplacement using drift end plugs. Bentonite distance blocks separate the supercontainers, one from another, along the drift. Steel compartment plugs can be used to seal off drift sections with higher inflow, thus isolating the different compartments within the drift. The present report describes the main processes potentially affecting the long-term safety of the system, covering radiation-related, thermal, hydraulic, mechanical, chemical (including microbiological) and radionuclide transport-related processes. The process descriptions deal sequentially with the main sub-systems: fuel/cavity in canister, cast iron insert and copper canister, buffer and other bentonite components, supercontainer

  9. Submarine Holocene sedimentary disturbances in the Olkiluoto area of the Gulf of Bothnia, Baltic Sea: a case of postglacial palaeoseismicity

    Science.gov (United States)

    Kotilainen, Aarno; Hutri, Kaisa-Leena

    2004-05-01

    High-resolution echo soundings were used to study the fault activity in the Olkiluoto area of the Gulf of Bothnia, southwestern Finland. Echo-sounding profiles in Holocene submarine sediments show normal faults, structures related to gas or groundwater seepage, submarine slides and slumps, and debris-flow type structures. The faults and other 'disturbance structures' occur along two bedrock lineaments. All faults occur at the same stratigraphical level, whose age is estimated at ˜10,700 calendar years BP (˜9500 radiocarbon years BP). It is suggested that their movement has been triggered by palaeoseismic event(s) when the Late Weichselian ice sheet was retreating from the site and bedrock stresses were released through lineaments and fracture zones. These are the first observations of postglacial fault movements in Quaternary sediments from southern Finland, but, the timing of these movements is contemporaneous with the incidence of postglacial bedrock faulting (˜9000-10,000 radiocarbon years BP) in northern Fennoscandia. The origin of the gas/groundwater seepages remains unclear. Their reflections in the echo-sounding profiles imply that part of the gas is derived from the organic-bearing Litorina and recent gyttja clays. However, at least some part of the gas is derived from the bedrock (deep gas).

  10. Greenland Analogue Project - Hydraulic properties of deformation zones and fracture domains at Forsmark, Laxemar and Olkiluoto for usage together with Geomodel version 1

    Energy Technology Data Exchange (ETDEWEB)

    Follin, Sven (SF GeoLogic AB (Sweden)); Stigsson, Martin (Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)); Rhen, Ingvar (Sweco Environment AB (Sweden)); Engstroem, Jon (Geologian tutkimuskeskus (Finland)); Klint, Knut Erik (De Nationale Geologiske Undersoegelser for Danmark og Groenland (Denmark))

    2011-05-15

    The database of the GAP site is under development. In order to meet the data needs of the different modelling teams working with groundwater flow modelling it has been decided to compile trial data sets comprising structural-hydraulic properties suitable for flow modelling on different scales. The properties provided in this report are based on data and groundwater flow modelling studies conducted for three sites located in the Fennoscandian Shield, two of which are studied by SKB, Forsmark and Laxemar, and one by Posiva, Olkiluoto. The provided hydraulic properties provided here are simplified to facilitate a readily usage together with the GAP Geomodel version 1.

  11. Geophysical borehole logging and optical imaging of the pilot hole ONK-PH2

    Energy Technology Data Exchange (ETDEWEB)

    Lahti, M. [Suomen Malmi Oy, Espoo (Finland); Heikkinen, E. [JP-Fintact Oy, Vantaa (Finland)

    2005-01-15

    Suomen Malmi Oy conducted geophysical borehole logging and optical imaging surveys of pilot hole ONK-PH2 in ONKALO tunnel at the Olkiluoto site in December 2004. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The methods applied are magnetic susceptibility, natural gamma radiation, gamma-gamma density, single point resistance, Wenner-resistivity, borehole radar, full waveform sonic and optical imaging. The assignment included the field work of all the surveys, integration of the data as well as interpretation of the acoustic and borehole radar data. The report describes the field operation, equipment, processing procedures, interpretation results and shows the obtained geophysical and image data. The data as well as the interpretation results are delivered digitally in WellCAD and Excel format. (orig.)

  12. Review of the GPS deformation monitoring studies commissioned by Posiva Oy on the Olkiluoto, Kivetty and Romuvaara sites, 1994-2000

    Energy Technology Data Exchange (ETDEWEB)

    Vermeer, M

    2002-05-01

    This report reviews the work done by scientists from the Finnish Geodetic Institute at the three sites Olkiluoto, Kivetty and Romuvaara over the years 1994-2000, with a view to detecting and measuring possible local crustal movements by means of geodetic GPS. The work, which consisted of measurements, computations and analysis, was reported in seven technical reports of Posiva Oy. Reviewed was also the work related to the three permanent stations established in these three sites, which have operated as part of the twelve-station national FinnRef network. The conclusion was that on the whole, the work has been performed professionally using state of the art equipment, measurement and analysis techniques by competent and experienced personnel. A number of suggestions for improvement and future work are given, mainly concerning the way the modelling of atmospheric propagation effects was done and how that affects the scale of the network computation, a proposal for monitoring the absolute scale, as well as remarks concerning the regular re-measurement of reserve marker ties, and the importance of continuing monitoring for a full solar activity cycle. The importance of interdisciplinarity is stressed. This review report is an outcome of the Bedrock Movements Investigations Group which supports STUKs regulatory activities related to confirming site investigations at Olkiluoto. (orig.)

  13. Carpal Tunnel Syndrome

    Science.gov (United States)

    ... arm. Just a passing cramp? It could be carpal tunnel syndrome. The carpal tunnel is a narrow passageway of ligament and ... difficult. Often, the cause is having a smaller carpal tunnel than other people do. Other causes include ...

  14. The Evaluation of Material Properties of Low-pH Cement Grout for the Application of Cementitious Materials to Deep Radioactive Waste Repository Tunnels

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Seop; Kwon, S. K.; Cho, W. J.; Kim, G. W

    2009-12-15

    Considering the current construction technology and research status of deep repository tunnels for radioactive waste disposal, it is inevitable to use cementitious materials in spite of serious concern about their long-term environmental stability. Thus, it is an emerging task to develop low pH cementitious materials. This study reviews the state of the technology on low pH cements developed in Sweden, Switzerland, France, and Japan as well as in Finland which is constructing a real deep repository site for high-level radioactive waste disposal. Considering the physical and chemical stability of bentonite which acts as a buffer material, a low pH cement limits to pH {<=}11 and pozzolan-type admixtures are used to lower the pH of cement. To attain this pH requirement, silica fume, which is one of the most promising admixtures, should occupy at least 40 wt% of total dry materials in cement and the Ca/Si ratio should be maintained below 0.8 in cement. Additionally, selective super-plasticizer needs to be used because a high amount of water is demanded from the use of a large amount of silica fume. In this report, the state of the technology on application of cementitious materials to deep repository tunnels for radioactive waste disposal was analysed. And the material properties of low-pH and high-pH cement grouts were evaluated base on the grout recipes of ONKALO in Finlan.

  15. Electron tunnel sensor technology

    Science.gov (United States)

    Waltman, S. B.; Kaiser, W. J.

    1989-01-01

    The recent development of Scanning Tunneling Microscopy technology allows the application of electron tunneling to position detectors for the first time. The vacuum tunnel junction is one of the most sensitive position detection mechanisms available. It is also compact, simple, and requires little power. A prototype accelerometer based on electron tunneling, and other sensor applications of this promising new technology are described.

  16. Geophysical drillhole logging and imaging of drillholes OL-KR54, OL-KR55 and OL-KR55B at Olkiluoto in 2010 and 2011

    Energy Technology Data Exchange (ETDEWEB)

    Tarvainen, A.-M. (Suomen Malmi Oy, Espoo (Finland)); Heikkinen, E. (Poeyry Finland Oy, Vantaa (Finland))

    2011-08-15

    Suomen Malmi Oy conducted geophysical drillhole logging as well as optical and acoustic imaging of the drillholes OL-KR54, OL-KR55 and OL-KR55B at the Olkiluoto site in Eurajoki between August 2010 and January 2011. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The assignment included the field work and data processing. The report describes field operation, equipment as well as processing procedures and shows the obtained results and an analysis of their quality in the appendices. New focused resistivity, susceptibility, natural gamma and density probes were tested and compared with old probes. This report describes the major features of new probes and the comparison with old probes. The raw and processed data are delivered digitally in WellCAD, PDF and Excel format. (orig.)

  17. Geophysical borehole logging of the boreholes KR30, KR31, KR31b, KR32, KR33, KR33b and KR24 Upper Part, at Olkiluoto 2005

    Energy Technology Data Exchange (ETDEWEB)

    Majapuro, J. [Suomen Malmi Oy, Espoo (Finland)

    2005-12-15

    Suomen Malmi Oy conducted geophysical borehole logging of the boreholes KR30, KR31, KR31B, KR32, KR33, KR33B and KR24 upper part at the Olkiluoto site in Eurajoki during December 2004, January, February and September 2005. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The assignment included the field work and processing of the acoustic data. The report describes the field operation, equipment as well as processing procedures and shows the obtained results and their quality in the appendices. The raw and processed data are delivered digitally in WellCAD and Excel format. (orig.)

  18. Hypersonic Tunnel Facility (HTF)

    Data.gov (United States)

    Federal Laboratory Consortium — The Hypersonic Tunnel Facility (HTF) is a blow-down, non-vitiated (clean air) free-jet wind tunnel capable of testing large-scale, propulsion systems at Mach 5, 6,...

  19. Transonic Dynamics Tunnel (TDT)

    Data.gov (United States)

    Federal Laboratory Consortium — The Transonic Dynamics Tunnel (TDT) is a continuous flow wind-tunnel facility capable of speeds up to Mach 1.2 at stagnation pressures up to one atmosphere. The TDT...

  20. Road and Railroad Tunnels

    Data.gov (United States)

    Department of Homeland Security — Tunnels in the United States According to the HSIP Tiger Team Report, a tunnel is defined as a linear underground passageway open at both ends. This dataset is based...

  1. Quantum theory of tunneling

    CERN Document Server

    Razavy, Mohsen

    2014-01-01

    In this revised and expanded edition, in addition to a comprehensible introduction to the theoretical foundations of quantum tunneling based on different methods of formulating and solving tunneling problems, different semiclassical approximations for multidimensional systems are presented. Particular attention is given to the tunneling of composite systems, with examples taken from molecular tunneling and also from nuclear reactions. The interesting and puzzling features of tunneling times are given extensive coverage, and the possibility of measurement of these times with quantum clocks are critically examined. In addition by considering the analogy between evanescent waves in waveguides and in quantum tunneling, the times related to electromagnetic wave propagation have been used to explain certain aspects of quantum tunneling times. These topics are treated in both non-relativistic as well as relativistic regimes. Finally, a large number of examples of tunneling in atomic, molecular, condensed matter and ...

  2. Hypersonic Tunnel Facility (HTF)

    Data.gov (United States)

    Federal Laboratory Consortium — The Hypersonic Tunnel Facility (HTF) is a blow-down, non-vitiated (clean air) free-jet wind tunnel capable of testing large-scale, propulsion systems at Mach 5, 6,...

  3. The Tunnels of Samos

    Science.gov (United States)

    Apostol, Tom M. (Editor)

    1995-01-01

    This 'Project Mathematics' series video from CalTech presents the tunnel of Samos, a famous underground aquaduct tunnel located near the capital of Pithagorion (named after the famed Greek mathematician, Pythagoras, who lived there), on one of the Greek islands. This tunnel was constructed around 600 BC by King Samos and was built under a nearby mountain. Through film footage and computer animation, the mathematical principles and concepts of why and how this aquaduct tunnel was built are explained.

  4. Magnetic tunnel junctions (MTJs)

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    We review the giant tunnel magnetoresistance (TMR) in ferromagnetic-insulator-ferromagnetic junctions discovered in recent years, which is the magnetoresistance (MR) associated with the spin-dependent tunneling between two ferromagnetic metal films separated by an insulating thin tunnel barrier. The theoretical and experimental results including junction conductance, magnetoresistance and their temperature and bias dependences are described.

  5. Safety case for the disposal of spent nuclear fuel at Olkiluoto. Surface and near-surface hydrological modelling in the biosphere assessment BSA-2012

    Energy Technology Data Exchange (ETDEWEB)

    Karvonen, T. [WaterHope, Helsinki (Finland)

    2013-05-15

    The Finnish nuclear waste disposal company, Posiva Oy, is planning an underground repository for spent nuclear fuel to be constructed on the island of Olkiluoto on the south-west coast of Finland. This study is part of the biosphere assessment (BSA-2012) within the safety case for the repository. The surface hydrological modelling described in this report is aimed at providing link between radionuclide transport in the geosphere and in the biosphere systems. The SVAT-model and Olkiluoto site scale surface hydrological model were calibrated and validated in the present day conditions using the input data provided by the Olkiluoto Monitoring Programme (OMO). During the next 10 000 years the terrain and ecosystem development is to a large extent driven by the postglacial crustal uplift. UNTAMO is a GIS toolbox developed for simulating land-uplift driven or other changes in the biosphere. All the spatial and temporal input data (excluding meteorological data) needed in the surface hydrological modelling were provided by the UNTAMO toolbox. The specific outputs given by UNTAMO toolbox are time-dependent evolution of the biosphere objects. They are continuous and sufficiently homogeneous sub-areas of the modelled area that could potentially receive radionuclides released from the repository. Possible ecosystem types for biosphere objects are coast, lake, river, forest, cropland, pasture and wetland. The primary goal of this study was to compute vertical and horizontal water fluxes in the biosphere objects. These data will be used in the biosphere radionuclide transport calculations. The method adopted here is based on calculating average vertical and horizontal fluxes for biosphere objects from the results of the full 3D-model. It was not necessary to develop any simplified hydrological model for the biosphere objects. This report includes modelling results from for the Reference Case (present day climate) and Terr{sub M}axAgri Case (maximum extent of agricultural areas

  6. Proton tunneling in solids

    Energy Technology Data Exchange (ETDEWEB)

    Kondo, J.

    1998-10-01

    The tunneling rate of the proton and its isotopes between interstitial sites in solids is studied theoretically. The phonons and/or the electrons in the solid have two effects on the tunneling phenomenon. First, they suppress the transfer integral between two neighbouring states. Second, they give rise to a finite lifetime of the proton state. Usually the second effect is large and the tunneling probability per unit time (tunneling rate) can be defined. In some cases, however, a coherent tunneling is expected and actually observed. (author)

  7. Geochemical and physical properties, distribution coefficients of soils and sediments at the Olkiluoto Island and in the reference area in 2010-2011

    Energy Technology Data Exchange (ETDEWEB)

    Lahdenperae, A.-M. [Saanio and Riekkola Oy, Helsinki (Finland)

    2014-04-15

    The report summarises the chemical, physical and mineralogical data and the calculated 'in situ' distribution coefficients (K{sub d}) values of the indigenous elements from the different types of soil and sediment samples at the Olkiluoto Island and in the Reference area that were taken in 2010-2011. The data has been collected in order to extend the understanding of the site evolution and for radionuclide transport analyses and modelling. 'In situ' distribution coefficients, K{sub d} values are used to indicate the relevant mobility of elements and radionuclides. This report is part of the entirety of soil and sediment data from different soil types, soil layers and environmental conditions collected earlier for the biosphere site description and development. Soil and sediment samples were taken at various depths of humus, peat, gyttja, sandy/fine sandy till and cropland soils. The analyses procedure varied to some extent between the samples. In all samples were analysed pH, LOI, C, N, and the total concentrations of the elements using HNO{sub 3}-HF extraction. The 'in situ' K{sub d} values were calculated using the formula by Sheppard et al.. For selected samples the easily leachable fraction was analysed by NH{sub 4}Ac (pH 4.5). Bulk density and mineralogy was determined for a few samples. Grain size distribution was measured only from till samples. The results are discussed and the physical-chemical data and distribution coefficients of the results are presented. The cation exchange capacity and base saturation are calculated for the sandy/fine sandy till samples from Olkiluoto. The K{sub d} values of the important indigenous elements Ag, Cl, Cs, I, Mo, Ni, Se and Sr are of main interest in biosphere development due to the longest half-lives of the associated radionuclides, thus having long interaction times. The K{sub d} data are inherently extremely variable due to nature of practical quantity in question, aggregating a number of

  8. Geophysical logging and imaging of drillholes OL-KR45, OL-KR49, OL-KR50 and OL-KR50B at Olkiluoto in 2009

    Energy Technology Data Exchange (ETDEWEB)

    Tarvainen, A.-M. (Suomen Malmi Oy, Espoo (Finland))

    2010-04-15

    Suomen Malmi Oy conducted geophysical drillhole logging, acoustic imaging and optical imaging of the drillholes OL-KR45 (re-measurements), OL-KR49, OL-KR50 and OL-KR50B at the Olkiluoto site in Eurajoki during January-November 2009. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The assignment included the field work and data processing. The report describes field operation, equipment as well as processing procedures and shows the obtained results and an analysis of their quality in the appendices. The raw and processed data are delivered digitally in WellCAD, PDF and Excel format. The missing density logging of drillhole OL-KR45 was carried out successfully. Dynamic rock mechanical parameters and natural gamma data were re-processed and this report includes updated WellCAD and Excel files. Acoustic imaging was also carried out in OL-KR45 after 700 meters depth. Acoustic imaging was used instead of optical imaging after 350 meters in OL-KR49 and 700 meters in OL-KR50. (orig.)

  9. Hydraulic Conductivity Measurements with HTU at Eurajoki, Olkiluoto, Borehole OL-KR15 and OL-KR15B, Year 2004

    Energy Technology Data Exchange (ETDEWEB)

    Haemaelaeinen, H.

    2005-07-01

    As a part of the site investigations for the disposal of spent nuclear fuel, hydraulic conductivity measurements were carried out in borehole OL-KR15 at Eurajoki, Olkiluoto. The objective was to investigate the distribution of the hydraulic conductivity in the surrounding bedrock volume. Measurements were carried out during 2003-2004 in two phases. The total length of the borehole OL-KR15 is 518,85 m and 158 45,14 m. Of the 471 ,5 m + 44,5 m total measurable length 414 m was covered with 237 standard tests with 2 m packer separation as specified in the research plan, partly with 1 m overlaps. 259 tests were initiated, but some of them ended to hardware or software errors or unsuitable parameter values. Double-packer constant-head method was used throughout with nominal 200 kPa overpressure. Injection stage lasted normally 20 minutes and fall-off stage 10 minutes. The tests were often shortened if there were clear indications that the hydraulic conductivity is below the measuring range of the system. The pressure in the test section was let to stabilise at least 5 min before injection. In some test sections the stabilisation or injection stage lasted several hours. Two transient (Horner and 1/Q) interpretations and one stationary-state (Moye) interpretation were made in-situ immediately after the test. The Hydraulic Testing Unit (HTU-system) is owned by Posiva Oy and it was operated by Geopros Oy. (orig.)

  10. Resonance Enhanced Tunneling

    CERN Document Server

    Matsumoto, S; Matsumoto, Sh.

    2000-01-01

    Time evolution of tunneling in thermal medium is examined using the real-time semiclassical formalism previously developed. Effect of anharmonic terms in the potential well is shown to give a new mechanism of resonance enhanced tunneling. If the friction from environment is small enough, this mechanism may give a very large enhancement for the tunneling rate. The case of the asymmetric wine bottle potential is worked out in detail.

  11. Tunnelling in Dante's Inferno

    Science.gov (United States)

    Furuuchi, Kazuyuki; Sperling, Marcus

    2017-05-01

    We study quantum tunnelling in Dante's Inferno model of large field inflation. Such a tunnelling process, which will terminate inflation, becomes problematic if the tunnelling rate is rapid compared to the Hubble time scale at the time of inflation. Consequently, we constrain the parameter space of Dante's Inferno model by demanding a suppressed tunnelling rate during inflation. The constraints are derived and explicit numerical bounds are provided for representative examples. Our considerations are at the level of an effective field theory; hence, the presented constraints have to hold regardless of any UV completion.

  12. Microsystem Aeromechanics Wind Tunnel

    Data.gov (United States)

    Federal Laboratory Consortium — The Microsystem Aeromechanics Wind Tunnel advances the study of fundamental flow physics relevant to micro air vehicle (MAV) flight and assesses vehicle performance...

  13. Ulnar tunnel syndrome.

    Science.gov (United States)

    Bachoura, Abdo; Jacoby, Sidney M

    2012-10-01

    Ulnar tunnel syndrome could be broadly defined as a compressive neuropathy of the ulnar nerve at the level of the wrist. The ulnar tunnel, or Guyon's canal, has a complex and variable anatomy. Various factors may precipitate the onset of ulnar tunnel syndrome. Patient presentation depends on the anatomic zone of ulnar nerve compression: zone I compression, motor and sensory signs and symptoms; zone II compression, isolated motor deficits; and zone III compression; purely sensory deficits. Conservative treatment such as activity modification may be helpful, but often, surgical exploration of the ulnar tunnel with subsequent ulnar nerve decompression is indicated.

  14. Virtual photons in macroscopic tunneling

    CERN Document Server

    Aichmann, Horst; Bruney, Paul

    2015-01-01

    Tunnelling processes are thought to proceed via virtual waves due to observed superluminal (faster than light) signal speeds. Some assume such speeds must violate causality. These assumptions contradict, for instance, superluminally tunnelled music and optical tunnelling couplers applied in fiber communication. Recently tunnelling barriers were conjectured to be cavities, wherein the tunnelled output signal is not causally related with the input. The tests described here resolve that tunnelling waves are virtual, propagations are superluminal, and causality is preserved.

  15. Tunnel fire dynamics

    CERN Document Server

    Ingason, Haukur; Lönnermark, Anders

    2015-01-01

    This book covers a wide range of issues in fire safety engineering in tunnels, describes the phenomena related to tunnel fire dynamics, presents state-of-the-art research, and gives detailed solutions to these major issues. Examples for calculations are provided. The aim is to significantly improve the understanding of fire safety engineering in tunnels. Chapters on fuel and ventilation control, combustion products, gas temperatures, heat fluxes, smoke stratification, visibility, tenability, design fire curves, heat release, fire suppression and detection, CFD modeling, and scaling techniques all equip readers to create their own fire safety plans for tunnels. This book should be purchased by any engineer or public official with responsibility for tunnels. It would also be of interest to many fire protection engineers as an application of evolving technical principles of fire safety.

  16. Installation of groundwater observation tubes OL-PVP36-38 and drilling of shallow drillholes OL-PP70-71 at Olkiluoto in Eurajoki 2011

    Energy Technology Data Exchange (ETDEWEB)

    Toropainen, V. [Suomen Malmi Oy, Espoo (Finland)

    2012-05-15

    In order to widen the groundwater monitoring network at Olkiluoto, Posiva Oy contracted Suomen Malmi Oy (Smoy) to install new groundwater observation tubes to three locations and to drill two shallow drillholes with standpipes. The identification numbers of the groundwater observation tubes are OL-PVP36, OL-PVP37A, 37B, 37C, OL-PVP38A, 38B, 38C and 38D, and the shallow drillholes are named OL-PP70 and OL-PP71. The observation tubes were installed and the shallow holes drilled between September 22nd and October 12th in 2011. The drilling rig used in the installation work was a GM-200 rig. Drilling equipment consisted of casing tubes (90/77 mm) with drilling bit, 55 mm geo rods and 64 mm drilling bits and T76-equipment for drilling the shallow holes. Monitoring pipes (PVC, 60/52 mm) were lowered into the holes inside the casings. The monitoring pipes consist of a lower section of riser pipe, a middle section of screen pipe and an upper section of riser pipe. The screen pipe slot size is 0.3 mm and the length of the screen section is two metres. Protective stainless steel covers with lock-up caps were installed around the monitoring tubes and the shallow drillholes. In addition to the installation of the tubes, the work included water level measurements after installation. The core samples of the shallow drillholes were logged and reported by geologist. Geological logging included the following parameters: lithology, foliation, fracture parameters, fractured zones, core loss, weathering, fracture frequency, RQD and rock quality. (orig.)

  17. Hydraulic Conductivity Measurements with HTU at Eurajoki, Olkiluoto, Boreholes OL-KR16, 16B, 17, 17B, 18 and 18B, Year 2004

    Energy Technology Data Exchange (ETDEWEB)

    Haemaelaeinen, H.

    2005-07-01

    As a part of the site investigations for the disposal of spent nuclear fuel, hydraulic con- ductivity measurements were carried out in boreholes OL-KR16, 16B, 17, 17 B, 18 and 18B at Eurajoki, Olkiluoto. The objective was to investigate the distribution of the hydraulic conductivity in the surrounding bedrock volume. Measurements were carried out during spring-summer 2004. The total lengths of the boreholes are: OL-KR16 170,20 m, OL-KR17 157,13 m and OL-KR18 125,49 m. Corresponding B-holes are around 45 m deep, parallel and adjacent to their 'parent' holes so representing the cased sections of them. The conbined measurable length of the holes is about 453,57 m, of which 429,15 m was covered with 217 standard tests at 2 m packer separation as specified in the research plan. 246 tests were initiated, but some had to be cancelled due to errors or unsuitable control parameters. Double-packer constant-head method was used throughout with nominal 200 kPa overpressure. Injection stage lasted normally 20 minutes and fall-off stage 10 minutes. The tests were often shortened if there were clear indications that the hydraulic conductivity is below the measuring range of the system. The pressure in the test section was let to stabilise at least 5 min before injection. In some test sections the stabilisation, injection or fall-off stage lasted several hours. Two transient (Horner and 1/Q) interpretations and one stationary-state (Moye) interpretation were made in-situ immediately after the test. The Hydraulic Testing Unit (HTU-system) is owned by Posiva Oy and it was operated by Geopros Oy. (orig.)

  18. Hydraulic conductivity measurements with HTU at Eurajoki, Olkiluoto, drillholes OL-KR52 and OL-KR47 in 2013 and 2014

    Energy Technology Data Exchange (ETDEWEB)

    Hurmerinta, E. [Poeyry Finland Oy, Vantaa (Finland)

    2014-09-15

    As a part of the site investigations for the disposal of spent nuclear fuel, hydraulic conductivity measurements were carried out with the HTU-equipment in drillholes OL KR52 and OL KR47 on the Olkiluoto investigation site. The objective was to investigate the distribution of the hydraulic conductivity in the surrounding bedrock volume. In OL-KR52 measurements were carried out between February 2013 and April 2013 and in OL-KR47 between October 2013 and February 2014. The total length of the drillhole OL-KR52 is 427.35 m, 376.00 m of which was covered by 188 standard tests with 2 m packer separation as specified in the measurement plan. Respectively, OL-KR47 is 1008.76 m long and 312 similar tests were conducted in it covering 624.00 m of the drillhole. These numbers include one equipment test measurement near the surface in OL-KR47. Double-packer constant-head method was used throughout with nominal 200 kPa overpressure. Injection stage lasted normally 20 minutes and fall-off stage 10 minutes. The tests were often shortened if there were clear indications that the hydraulic conductivity is below the measuring range of the system. The pressure in the test section was let to stabilise at least 5 min before injection. In some test sections the test stage times were extended if longer times were needed to obtain correct results or when suited to the working schedule. Two transient (Horner and 1/Q) interpretations and one stationary-state (Moye) interpretation were made in-situ immediately after the test. The Hydraulic Testing Unit (HTU-system) is owned by Posiva Oy and it was operated by Poeyry Finland Oy in co-operation with Geopros Oy. (orig.)

  19. Hydraulic conductivity measurements with HTU at Eurajoki, Olkiluoto, drillholes OL-KR19, OL-KR45 and OL-KR46 in 2009 and 2010

    Energy Technology Data Exchange (ETDEWEB)

    Haemaelaeinen, H. [Geopros Oy, Helsinki (Finland)

    2011-10-15

    As a part of the site investigations for the disposal of spent nuclear fuel, hydraulic conductivity measurements were carried out with HTU-equipment in drillholes OL-KR19, OL-KR45 and OL-KR46 at Eurajoki, Olkiluoto. The objective was to investigate the distribution of the hydraulic conductivity in the surrounding bedrock volume. Measurements were carried out during 2009 and 2010. The total length of the borehole OL-KR19 is 544,34 m, 241,80 m of which was covered by 121 standard tests with 2 m packer separation as specified in the measurement plan. Respectively, OL-KR45 is 1023,30 m long and 63 similar tests were made in it covering 126,00 m of the hole and OL-KR46 600,10 m long, 151 tests made covering 301,35 m. The measured sections are around the depths of the planned repository. Double-packer constant-head method was used throughout with nominal 200 kPa overpressure. Injection stage lasted normally 20 minutes and fall-off stage 10 minutes. The tests were often shortened if there were clear indications that the hydraulic conductivity is below the measuring range of the system. The pressure in the test section was let to stabilise at least 5 min before injection. In some test sections the test stage times were extended. Two transient (Horner and 1/Q) interpretations and one stationary- state (Moye) interpretation were made in-situ immediately after the test. The Hydraulic Testing Unit (HTU-system) is owned by Posiva Oy and it was operated by Geopros Oy. (orig.)

  20. Comparison of different extractions of the soil samples OL-FEH914254, OL-FEH917258 and OL-FIP10, Olkiluoto, SW Finland

    Energy Technology Data Exchange (ETDEWEB)

    Lahdenperae, A.-M. [Saanio and Riekkola Oy, Helsinki (Finland)

    2014-04-15

    The seven different extractions are used to evaluate and compare the element concentrations and solubility both dried/sieved and fresh mineral soil samples OLFEH914254, OL-FEH917258, OL-FIP10 and OL-FIP10 and humus sample OL-FIP10 taken from the Olkiluoto Island in 2010. The study focuses on the key elements assigned top priority in the biosphere assessments: Cl, Cs, I, Mo, Nb, Ni, Se and Sr. The priority grouping of radionuclides is based on their expected relevance for long-term safety using a simple screening evaluation applied on the calculations cases analysed in the biosphere analyses in the safety case studies and the cases to be analysed from the radionuclide transport model. The extractions included: total, aqua regia, NH{sub 4}Ac (pH 4.5) and water leach extractions. The sequential extractions consisted of: exchangeable, acid-soluble/bound to carbonates, bound to Fe-Mn oxides, bound to organic matter and residual fractions, in addition, separate aqua regia extraction was included. Molybdenum, niobium and selenium concentrations were higher in aqua regia extraction than in the total extraction. Aqua regia extractions were analysed by using different methods in two different laboratories, and thus the results are not completely comparable for the most of the elements. In addition, dry and organic matter, pH, cation exchange capacity and grain size distribution were measured. The pH values measured in the deionised water were on average 0.5 units higher than pH values extracted by 0.01 M CaCl{sub 2}. The CEC was significantly higher in the humus sample than in the mineral soil samples. In modelling migration of elements in ecosystems, especially radionuclides, it is used distribution coefficients (K{sub d} values) and concentration ratios (CR), both including a component of concentration in the solids. Solubility of different solid elements varies widely depending the used methods and extracts. (orig.)

  1. Ultrafast scanning tunneling microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Botkin, D.A. [California Univ., Berkeley, CA (United States). Dept. of Physics]|[Lawrence Berkeley Lab., CA (United States)

    1995-09-01

    I have developed an ultrafast scanning tunneling microscope (USTM) based on uniting stroboscopic methods of ultrafast optics and scanned probe microscopy to obtain nanometer spatial resolution and sub-picosecond temporal resolution. USTM increases the achievable time resolution of a STM by more than 6 orders of magnitude; this should enable exploration of mesoscopic and nanometer size systems on time scales corresponding to the period or decay of fundamental excitations. USTM consists of a photoconductive switch with subpicosecond response time in series with the tip of a STM. An optical pulse from a modelocked laser activates the switch to create a gate for the tunneling current, while a second laser pulse on the sample initiates a dynamic process which affects the tunneling current. By sending a large sequence of identical pulse pairs and measuring the average tunnel current as a function of the relative time delay between the pulses in each pair, one can map the time evolution of the surface process. USTM was used to measure the broadband response of the STM`s atomic size tunnel barrier in frequencies from tens to hundreds of GHz. The USTM signal amplitude decays linearly with the tunnel junction conductance, so the spatial resolution of the time-resolved signal is comparable to that of a conventional STM. Geometrical capacitance of the junction does not appear to play an important role in the measurement, but a capacitive effect intimately related to tunneling contributes to the measured signals and may limit the ultimate resolution of the USTM.

  2. Virtual photons in macroscopic tunneling

    OpenAIRE

    Aichmann, Horst; Nimtz, Guenter; Bruney, Paul

    2015-01-01

    Tunnelling processes are thought to proceed via virtual waves due to observed superluminal (faster than light) signal speeds. Some assume such speeds must violate causality. These assumptions contradict, for instance, superluminally tunnelled music and optical tunnelling couplers applied in fiber communication. Recently tunnelling barriers were conjectured to be cavities, wherein the tunnelled output signal is not causally related with the input. The tests described here resolve that tunnelli...

  3. Wind Tunnel Testing Facilities

    Data.gov (United States)

    Federal Laboratory Consortium — NASA Ames Research Center is pleased to offer the services of our premier wind tunnel facilities that have a broad range of proven testing capabilities to customers...

  4. INCAS TRISONIC WIND TUNNEL

    Directory of Open Access Journals (Sweden)

    Florin MUNTEANU

    2009-09-01

    Full Text Available The 1.2 m x 1.2 m Trisonic Blowdown Wind Tunnel is the largest of the experimental facilities at the National Institute for Aerospace Research - I.N.C.A.S. "Elie Carafoli", Bucharest, Romania. The tunnel has been designed by the Canadian company DSMA (now AIOLOS and since its commissioning in 1978 has performed high speed aerodynamic tests for more than 120 projects of aircraft, missiles and other objects among which the twin jet fighter IAR-93, the jet trainer IAR-99, the MIG-21 Lancer, the Polish jet fighter YRYDA and others. In the last years the wind tunnel has been used mostly for experimental research in European projects such as UFAST. The high flow quality parameters and the wide range of testing capabilities ensure the competitivity of the tunnel at an international level.

  5. Quantum tunneling with friction

    Science.gov (United States)

    Tokieda, M.; Hagino, K.

    2017-05-01

    Using the phenomenological quantum friction models introduced by P. Caldirola [Nuovo Cimento 18, 393 (1941), 10.1007/BF02960144] and E. Kanai [Prog. Theor. Phys. 3, 440 (1948), 10.1143/ptp/3.4.440], M. D. Kostin [J. Chem. Phys. 57, 3589 (1972), 10.1063/1.1678812], and K. Albrecht [Phys. Lett. B 56, 127 (1975), 10.1016/0370-2693(75)90283-X], we study quantum tunneling of a one-dimensional potential in the presence of energy dissipation. To this end, we calculate the tunneling probability using a time-dependent wave-packet method. The friction reduces the tunneling probability. We show that the three models provide similar penetrabilities to each other, among which the Caldirola-Kanai model requires the least numerical effort. We also discuss the effect of energy dissipation on quantum tunneling in terms of barrier distributions.

  6. Water Tunnel Facility

    Data.gov (United States)

    Federal Laboratory Consortium — NETL’s High-Pressure Water Tunnel Facility in Pittsburgh, PA, re-creates the conditions found 3,000 meters beneath the ocean’s surface, allowing scientists to study...

  7. Wind Tunnel Facility

    Data.gov (United States)

    Federal Laboratory Consortium — This ARDEC facility consists of subsonic, transonic, and supersonic wind tunnels to acquire aerodynamic data. Full-scale and sub-scale models of munitions are fitted...

  8. Gravity Tunnel Drag

    CERN Document Server

    Concannon, Thomas

    2016-01-01

    The time it takes to fall down a tunnel through the center of the Earth to the other side takes approximately 42 minutes, but only when given several simplifying assumptions: a uniform density Earth; a gravitational field that varies linearly with radial position; a non-rotating Earth; a tunnel evacuated of air; and zero friction along the sides of the tunnel. Though several papers have singularly relaxed the first three assumptions, in this paper we relax the final two assumptions and analyze the motion of a body experiencing these types of drag forces in the tunnel. Under such drag forces, we calculate the motion of a transport vehicle through a tunnel of the Earth under uniform density, under constant gravitational acceleration, and finally under the more realistic Preliminary Reference Earth Model (PREM) density data. We find the density profile corresponding to a constant gravitational acceleration better models the motion through the tunnel compared to the PREM density profile, and the uniform density m...

  9. Suppression of tunneling rate fluctuations in tunnel field-effect transistors by enhancing tunneling probability

    Science.gov (United States)

    Mori, Takahiro; Migita, Shinji; Fukuda, Koichi; Asai, Hidehiro; Morita, Yukinori; Mizubayashi, Wataru; Liu, Yongxun; O’uchi, Shin-ichi; Fuketa, Hiroshi; Otsuka, Shintaro; Yasuda, Tetsuji; Masahara, Meishoku; Ota, Hiroyuki; Matsukawa, Takashi

    2017-04-01

    This paper discusses the impact of the tunneling probability on the variability of tunnel field-effect transistors (TFETs). Isoelectronic trap (IET) technology, which enhances the tunneling current in TFETs, is used to suppress the variability of the ON current and threshold voltage. The simulation results show that suppressing the tunneling rate fluctuations results in suppression of the variability. In addition, a formula describing the relationship between the tunneling rate fluctuations and the electric field strength is derived based on Kane’s band-to-band tunneling model. This formula indicates that the magnitude of the tunneling rate fluctuations is proportional to the magnitude of the fluctuations in the electric field strength and a higher tunneling probability results in a lower variability. The derived relationship is universally valid for any technologies that exploit enhancement of the tunneling probability, including IET technology, channel material engineering, heterojunctions, strain engineering, etc.

  10. Early times in tunneling

    CERN Document Server

    García-Calderón, G; Garcia-Calderon, Gaston; Villavicencio, Jorge

    2000-01-01

    Exact analytical solutions of the time-dependent Schr\\"odinger equation with the initial condition of an incident cutoff wave are used to investigate the traversal time for tunneling. The probability density starts from a vanishing value along the tunneling and transmitted regions of the potential. At the barrier width it exhibits, at early times, a distribution of traversal times that typically has a peak $\\tau_p$ and a width $\\Delta \\tau$. Numerical results for other tunneling times, as the phase-delay time, fall within $\\Delta \\tau$. The B\\"uttiker traversal time is the closest to $\\tau_p$. Our results resemble calculations based on Feynman paths if its noisy behaviour is ignored.

  11. Tunneling Through Black Rings

    Institute of Scientific and Technical Information of China (English)

    ZHAO Liu

    2007-01-01

    Hawking radiation of black ring solutions to 5-dimensional Einstein-Maxwell-dilaton theory is analyzed by use of the Parikh-Wilczek tunneling method. To get the correct tunneling amplitude and emission rate, we adopt and develop the Angheben-Nadalini-Vanzo-Zerbini covariant approach to cover the effects of rotation and electronic discharge all at once, and the effect of back reaction is also taken into account. This constitutes a unified approach to the tunneling problem. Provided the first law of thermodynamics for black rings holds, the emission rate is proportional to the exponential of the change of Bekenstein-Hawking entropy. Explicit calculation for black ring temperatures agrees exactly with the results obtained via the classical surface gravity method and the quasi-local formalism.

  12. Femtosecond scanning tunneling microscope

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, A.J.; Donati, G.P.; Rodriguez, G.; Gosnell, T.R.; Trugman, S.A.; Some, D.I.

    1998-11-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). By combining scanning tunneling microscopy with ultrafast optical techniques we have developed a novel tool to probe phenomena on atomic time and length scales. We have built and characterized an ultrafast scanning tunneling microscope in terms of temporal resolution, sensitivity and dynamic range. Using a novel photoconductive low-temperature-grown GaAs tip, we have achieved a temporal resolution of 1.5 picoseconds and a spatial resolution of 10 nanometers. This scanning tunneling microscope has both cryogenic and ultra-high vacuum capabilities, enabling the study of a wide range of important scientific problems.

  13. Tunneling in Axion Monodromy

    CERN Document Server

    Brown, Jon; Shiu, Gary; Soler, Pablo

    2016-01-01

    The Coleman formula for vacuum decay and bubble nucleation has been used to estimate the tunneling rate in models of axion monodromy in recent literature. However, several of Coleman's original assumptions do not hold for such models. Here we derive a new estimate with this in mind using a similar Euclidean procedure. We find that there are significant regions of parameter space for which the tunneling rate in axion monodromy is not well approximated by the Coleman formula. However, there is also a regime relevant to large field inflation in which both estimates parametrically agree. We also briefly comment on the applications of our results to the relaxion scenario.

  14. Tunneling in axion monodromy

    Science.gov (United States)

    Brown, Jon; Cottrell, William; Shiu, Gary; Soler, Pablo

    2016-10-01

    The Coleman formula for vacuum decay and bubble nucleation has been used to estimate the tunneling rate in models of axion monodromy in recent literature. However, several of Coleman's original assumptions do not hold for such models. Here we derive a new estimate with this in mind using a similar Euclidean procedure. We find that there are significant regions of parameter space for which the tunneling rate in axion monodromy is not well approximated by the Coleman formula. However, there is also a regime relevant to large field inflation in which both estimates parametrically agree. We also briefly comment on the applications of our results to the relaxion scenario.

  15. Long distance tunneling

    CERN Document Server

    Ivlev, B I

    2005-01-01

    Quantum tunneling between two potential wells in a magnetic field can be strongly increased when the potential barrier varies in the direction perpendicular to the line connecting the two wells and remains constant along this line. A periodic structure of the wave function is formed in the direction joining the wells. The resulting motion can be coherent like motion in a conventional narrow band periodic structure. A particle penetrates the barrier over a long distance which strongly contrasts to WKB-like tunneling. The whole problem is stationary. The coherent process can be influenced by dissipation.

  16. Breaking through the tranfer tunnel

    CERN Multimedia

    Laurent Guiraud

    2001-01-01

    This image shows the tunnel boring machine breaking through the transfer tunnel into the LHC tunnel. Proton beams will be transferred from the SPS pre-accelerator to the LHC at 450 GeV through two specially constructed transfer tunnels. From left to right: LHC Project Director, Lyn Evans; CERN Director-General (at the time), Luciano Maiani, and Director for Accelerators, Kurt Hubner.

  17. Geophysical drillhole logging and imaging of drillholes OL-KR51, OL-KR52, OL-KR52B, OL-KR53 and OL-KR53B at Olkiluoto in 2009 and 2010

    Energy Technology Data Exchange (ETDEWEB)

    Tarvainen, A.-M. (Suomen Malmi Oy, Espoo (Finland))

    2010-10-15

    Suomen Malmi Oy conducted geophysical drillhole logging and optical imaging of the drillholes OL-KR51, OL-KR52, OL-KR52B, OL-KR53 and OL-KR53B at the Olkiluoto site in Eurajoki between November 2009 and February 2010. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The assignment included the field work and data processing. The report describes field operation, equipment as well as processing procedures and shows the obtained results and an analysis of their quality in the appendices. The raw and processed data are delivered digitally in WellCAD, PDF and Excel format. (orig.)

  18. Tunnelling with wormhole creation

    Energy Technology Data Exchange (ETDEWEB)

    Ansoldi, S. [National Institute of Nuclear Physics (INFN) (Italy); Tanaka, T., E-mail: tanaka@yukawa.kyoto-u.ac.jp [Kyoto University, Department of Physics (Japan)

    2015-03-15

    The description of quantum tunnelling in the presence of gravity shows subtleties in some cases. We discuss wormhole production in the context of the spherically symmetric thin-shell approximation. By presenting a fully consistent treatment based on canonical quantization, we solve a controversy present in the literature.

  19. INCAS SUBSONIC WIND TUNNEL

    Directory of Open Access Journals (Sweden)

    Corneliu STOICA

    2009-09-01

    Full Text Available The INCAS Subsonic Wind Tunnel is a closed circuit, continuous, atmospheric pressure facility with a maximum speed of 110 m/s. The test section is octagonal ,of 2.5 m wide, 2.0 m high and 4 m long. The tunnel is powered by a 1200 kW, air cooled variable speed DC motor which drives a 12 blade, 3.5 m diameter fan and is equipped with a six component pyramidal type external mechanical balance with a 700 Kgf maximum lift capacity.The angle of attack range is between -45º and +45º while the yaw angle range is between -140º and +216º .The data acquisition system has been modified recently to allow the recording of all test data on a PC - type computer using LABVIEW and a PXI – type chassis containing specialized data acquisition modules.The tunnel is equipped with a variable frequency electrical supply system for powered models and a 10 bar compressed air supply for pneumatic flow control applications.In the recent years the subsonic wind tunnel has been intensively used for tests within several European projects (AVERT, CESAR and others.

  20. Classical trajectories and quantum tunneling

    CERN Document Server

    Ivlev, B I

    2003-01-01

    The problem of inter-band tunneling in a semiconductor (Zener breakdown) in a nonstationary and homogeneous electric field is solved exactly. Using the exact analytical solution, the approximation based on classical trajectories is studied. A new mechanism of enhanced tunneling through static non-one-dimensional barriers is proposed in addition to well known normal tunneling solely described by a trajectory in imaginary time. Under certain conditions on the barrier shape and the particle energy, the probability of enhanced tunneling is not exponentially small even for non-transparent barriers, in contrast to the case of normal tunneling.

  1. Educational Wind Tunnel

    Directory of Open Access Journals (Sweden)

    Juozas Bielskus

    2012-12-01

    Full Text Available The paper analyzes an educational wind tunnel produced by the Department of Building Energetics (DBE of Vilnius Gediminas Technical University. The equipment could be used for performing laboratory works and simple research. The article presents the projection of inflow and outlet velocity in the working chamber of DBE wind tunnel and carries out actual noise level measurement. The received data are compared with information on the level of noise generated by the fan considering instructions provided by the manufacturer. In order to assess the reliability of the computer program, simulation applying PHOENICS software has been conducted. The aim of modeling is to simulate a pilot model and to compare the obtained results with those of an analogous test presented in scientific articles.Article in Lithuanian

  2. "Phantom" carpal tunnel syndrome.

    Science.gov (United States)

    Braverman, D L; Root, B C

    1997-10-01

    Phantom sensation is ubiquitous among persons who have had amputation; however, if it develops into phantom pain, a thorough clinical investigation must ensue. We illustrate this with the case of a 49-year-old woman, 14 years after traumatic amputation of her left 2nd through 5th fingers, and 10 years after traumatic left transfemoral amputation. She had had phantom sensation in her absent fingers for years and developed progressive pain in her phantom fingers 3 months before presentation. Nerve conduction study revealed a high-normal distal motor latency of the left median nerve and a positive Bactrian test (sensitivity 87%). She was diagnosed with "phantom" carpal tunnel syndrome and treated with a resting wrist splint, decreased weight bearing on the left upper limb, and two corticosteroid carpal tunnel injections with marked improvement. Clinicians should recognize that phantom pain may be referred from a more proximal region and may be amenable to conservative management.

  3. Carpal tunnel syndrome treatment

    Directory of Open Access Journals (Sweden)

    Emilio Filippucci

    2011-09-01

    Full Text Available Carpal tunnel syndrome, the most common peripheral neuropathy, results from compression of the median nerve at the wrist, and is a cause of pain, numbness and tingling in the upper extremities and an increasingly recognized cause of work disability. If carpal tunnel syndrome seems likely, conservative management with splinting should be initiated. Moreover, it has suggested that patients reduce activities at home and work that exacerbate symptoms. Pyridoxine and diuretics, since are largely utilised, are no more effective than placebo in relieving the symptoms. Non steroidal anti-inflammatory drugs and orally administered corticosteroids can be effective for short-term management (two to four weeks, but local corticosteroid injection may improve symptoms for a longer period. Injection is especially effective if there is no loss of sensibility or thenar-muscle atrophy and weakness, and if symptoms are intermittent rather than constant. If symptoms are refractory to conservative measures, the option of surgical therapy may be considered.

  4. [Carpal tunnel syndrome treatment].

    Science.gov (United States)

    De Angelis, Rossella; Salaffi, Fausto; Filippucci, Emilio; Grassi, Walter

    2006-01-01

    Carpal tunnel syndrome, the most common peripheral neuropathy, results from compression of the median nerve at the wrist, and is a cause of pain, numbness and tingling in the upper extremities and an increasingly recognized cause of work disability. If carpal tunnel syndrome seems likely, conservative management with splinting should be initiated. Moreover, it has suggested that patients reduce activities at home and work that exacerbate symptoms. Pyridoxine and diuretics, since are largely utilised, are no more effective than placebo in relieving the symptoms. Non steroidal anti-inflammatory drugs and orally administered corticosteroids can be effective for short-term management (two to four weeks), but local corticosteroid injection may improve symptoms for a longer period. Injection is especially effective if there is no loss of sensibility or thenar-muscle atrophy and weakness, and if symptoms are intermittent rather than constant. If symptoms are refractory to conservative measures, the option of surgical therapy may be considered.

  5. Programmable ferroelectric tunnel memristor

    Directory of Open Access Journals (Sweden)

    Andy eQuindeau

    2014-02-01

    Full Text Available We report an analogously programmable memristor based on genuine electronic resistive switching combining ferroelectric switching and electron tunneling. The tunnel current through an 8 unit cell thick epitaxial Pb(Zr[0.2]Ti[0.8]O[3] film sandwiched between La[0.7]Sr[0.3]MnO[3] and cobalt electrodes obeys the Kolmogorov-Avrami-Ishibashi model for bidimensional growth with a characteristic switching time in the order of 10^-7 seconds. The analytical description of switching kinetics allows us to develop a characteristic transfer function that has only one parameter viz. the characteristic switching time and fully predicts the resistive states of this type of memristor.

  6. The beam dump tunnels

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    In these images workers are digging the tunnels that will be used to dump the counter-circulating beams. Travelling just a fraction under the speed of light, the beams at the LHC will each carry the energy of an aircraft carrier travelling at 12 knots. In order to dispose of these beams safely, a beam dump is used to extract the beam and diffuse it before it collides with a radiation shielded graphite target.

  7. Carpal tunnel release

    DEFF Research Database (Denmark)

    Larsen, Morten Bo; Sørensen, A I; Crone, K L;

    2013-01-01

    A single-blind, randomized, controlled trial was done to compare the results of carpal tunnel release using classic incision, short incision, or endoscopic technique. In total, 90 consecutive cases were included. Follow-up was 24 weeks. We found a significantly shorter sick leave in the endoscopi...... incision could be found. There were no serious complications in either group. The results indicate that the endoscopic procedure is safe and has the benefit of faster rehabilitation and return to work....

  8. Inelastic tunneling in superconducting junctions

    Energy Technology Data Exchange (ETDEWEB)

    Hlobil, Patrik Christian

    2016-06-10

    In this dissertation a theoretical formalism of elastic and inelastic tunneling spectroscopy is developed for superconductors. The underlying physical processes behind the different two tunneling channels and their implications for the interpretation of experimental tunneling data are investigated in detail, which can explain the background conductance seen in the cuprate and iron-based superconductors. Further, the properties of the emitted light from a superconducting LED are investigated.

  9. Gap anisotropy and tunneling currents. [MPS3

    DEFF Research Database (Denmark)

    Lazarides, N.; Sørensen, Mads Peter

    1996-01-01

    The tunneling Hamiltonian formalism is applied to calculate the tunnelingcurrents through a small superconducting tunnel junction. The formalism isextended to nonconstant tunneling matrix elements. The electrodes of thejunction are assumed to...

  10. Engineers win award for Swiss tunnel

    CERN Multimedia

    2003-01-01

    A Derby engineering consultancy has won the Tunnelling Industry Award 2003 for Excellence in Tunnel Design, offered by the British Tunnelling Society, for its work on the LHC in Geneva, Switzerland (1/2 page).

  11. Scanning Tunneling Microscopy

    Science.gov (United States)

    1992-03-17

    and c. M. Bertoni, J, Phys. C10, 1911 (1977); J, D. Joannoroulos and M.-r. Cohen, Phys. Rev. B10 , 5075 (1974); E. J, Mele and J. D. JOannopoulos...igh ’""f! nif ~<:ation.l’rc~mn.•hiy a pn.ltruJing ’-·luster or tJtnlp o{ a1onh at tb .. c:nd of ihis fint!t:r ad~ ~1s the tunnelling ti;". N ano

  12. A virtual detector approach to tunnel ionization and tunneling times

    CERN Document Server

    Teeny, Nicolas; Bauke, Heiko

    2016-01-01

    Tunneling times in atomic ionization is studied theoretically by a virtual detector approach. A virtual detector is a hypothetical device that allows to monitor the wave-function's density with spatial and temporal resolution during the ionization process. With this theoretical approach, it becomes possible to define unique moments when the electron enters and leaves with highest probability the classically forbidden region from first principles and a tunneling time can be specified unambiguously. It is shown that neither the moment when the electron enters the tunneling barrier nor when it leaves the tunneling barrier coincide with the moment when the external electric field reaches its maximum. Under the tunneling barrier as well as at the exit the electron has a nonzero velocity in electric field direction. This nonzero exit velocity has to be incorporated when the free motion of the electron is modeled by classical equations of motion.

  13. Tunnel face stability and ground settlement in pressurized shield tunnelling

    Institute of Scientific and Technical Information of China (English)

    苏艺; 汪国锋; 周庆宏

    2014-01-01

    An analysis of the stability of large-diameter circular tunnels and ground settlement during tunnelling by a pressurized shield was presented. An innovative three-dimensional translational multi-block failure mechanism was proposed to determine the face support pressure of large-shield tunnelling. Compared with the currently available mechanisms, the proposed mechanism has two unique features: (1) the supporting pressure applied to the tunnel face is assumed to have a non-uniform rather than uniform distribution, and (2) the method takes into account the entire circular excavation face instead of merely an inscribed ellipse. Based on the discrete element method, a numerical simulation of the Shanghai Yangtze River Tunnel was carried out using the Particle Flow Code in two dimensions. The immediate ground movement during excavation, as well as the behaviour of the excavation face, the shield movement, and the excavated area, was considered before modelling the excavation process.

  14. Magnetic tunnel junctions with monolayer hexagonal boron nitride tunnel barriers

    Energy Technology Data Exchange (ETDEWEB)

    Piquemal-Banci, M.; Galceran, R.; Bouzehouane, K.; Anane, A.; Petroff, F.; Fert, A.; Dlubak, B.; Seneor, P. [Unité Mixte de Physique, CNRS, Thales, Univ. Paris-Sud, Université Paris-Saclay, Palaiseau 91767 (France); Caneva, S.; Martin, M.-B.; Weatherup, R. S.; Kidambi, P. R.; Robertson, J.; Hofmann, S. [Department of Engineering, University of Cambridge, Cambridge CB21PZ (United Kingdom); Xavier, S. [Thales Research and Technology, 1 avenue Augustin Fresnel, Palaiseau 91767 (France)

    2016-03-07

    We report on the integration of atomically thin 2D insulating hexagonal boron nitride (h-BN) tunnel barriers into Co/h-BN/Fe magnetic tunnel junctions (MTJs). The h-BN monolayer is directly grown by chemical vapor deposition on Fe. The Conductive Tip Atomic Force Microscopy (CT-AFM) measurements reveal the homogeneity of the tunnel behavior of our h-BN layers. As expected for tunneling, the resistance depends exponentially on the number of h-BN layers. The h-BN monolayer properties are also characterized through integration into complete MTJ devices. A Tunnel Magnetoresistance of up to 6% is observed for a MTJ based on a single atomically thin h-BN layer.

  15. Current Status of the Nuclear Waste Management Programme in Finland - 13441

    Energy Technology Data Exchange (ETDEWEB)

    Lehto, Kimmo; Vuorio, Petteri [Posiva Oy, Olkiluoto, FI-27160 Eurajoki (Finland)

    2013-07-01

    Pursuant to the Decision-in-Principle of 2001 the Finnish programme for geologic disposal of spent fuel has now moved to the phase of applying for construction licence to build up the encapsulation plant and underground repository. The main objective of former programme phase, underground characterisation phase, was to confirm - or refute - the suitability of the Olkiluoto site by investigations conducted underground at the actual depth of the repository. The construction work of the access tunnel to the rock characterisation facility (ONKALO) started in the late summer of 2004. The site research and investigations work aimed at the maturity needed for submission of the application for construction license of the actual repository in end of 2012. This requires, however, that also the technology has reached the maturity needed. The design and technical plans form the necessary platform for the development of the safety case for spent fuel disposal. A plan, 'road map', has been produced for the portfolio of reports that demonstrates the safety of disposal as required by the criteria set by the government and further detailed by the safety authority, STUK. (authors)

  16. Tunneling Ionization of Diatomic Molecules

    DEFF Research Database (Denmark)

    Svensmark, Jens Søren Sieg

    2016-01-01

    barriers, an ability classical particles do not possess. Tunnelling is a fundamental quantum mechanical process, a process that is distinctly non-classical, so solving this tunnelling problem is not only relevant for molecular physics, but also for quantum theory in general. In this dissertation the theory...

  17. Tunneling magnetic force microscopy

    Science.gov (United States)

    Burke, Edward R.; Gomez, Romel D.; Adly, Amr A.; Mayergoyz, Isaak D.

    1993-01-01

    We have developed a powerful new tool for studying the magnetic patterns on magnetic recording media. This was accomplished by modifying a conventional scanning tunneling microscope. The fine-wire probe that is used to image surface topography was replaced with a flexible magnetic probe. Images obtained with these probes reveal both the surface topography and the magnetic structure. We have made a thorough theoretical analysis of the interaction between the probe and the magnetic fields emanating from a typical recorded surface. Quantitative data about the constituent magnetic fields can then be obtained. We have employed these techniques in studies of two of the most important issues of magnetic record: data overwrite and maximizing data-density. These studies have shown: (1) overwritten data can be retrieved under certain conditions; and (2) improvements in data-density will require new magnetic materials. In the course of these studies we have developed new techniques to analyze magnetic fields of recorded media. These studies are both theoretical and experimental and combined with the use of our magnetic force scanning tunneling microscope should lead to further breakthroughs in the field of magnetic recording.

  18. Carpal tunnel syndrome and acromegaly.

    Science.gov (United States)

    Baum, H; Lüdecke, D K; Herrmann, H D

    1986-01-01

    50 patients with acromegaly and carpal tunnel syndrome have been examined electrophysiologically before and after transnasal operation of the pituitary adenoma. 32 of the 50 patients (64%) had symptoms of carpal tunnel syndrome. 13 of them had neurological deficits. 28 of the examined patients had pathological neurographical findings only. About 1 week post-operatively DL was decreased in 43%; in 10 out of 13 patients with neurological deficits DL decreased. GH was normalized in 80% and reduced to 5-10 micrograms/l in a further 10%. The investigation did not show whether the carpal tunnel syndrome only depended on a GH increase or on other factors also such as e.g., on the duration of symptoms or tissue changes. None of the patients had the transversal carpal ligament operated on. The coincidence between acromegaly and carpal tunnel syndrome was 64%. In 3 cases the carpal tunnel syndrome was the leading sign to the diagnosis of acromegaly.

  19. Tunnel electroresistance through organic ferroelectrics

    Science.gov (United States)

    Tian, B. B.; Wang, J. L.; Fusil, S.; Liu, Y.; Zhao, X. L.; Sun, S.; Shen, H.; Lin, T.; Sun, J. L.; Duan, C. G.; Bibes, M.; Barthélémy, A.; Dkhil, B.; Garcia, V.; Meng, X. J.; Chu, J. H.

    2016-05-01

    Organic electronics is emerging for large-area applications such as photovoltaic cells, rollable displays or electronic paper. Its future development and integration will require a simple, low-power organic memory, that can be written, erased and readout electrically. Here we demonstrate a non-volatile memory in which the ferroelectric polarisation state of an organic tunnel barrier encodes the stored information and sets the readout tunnel current. We use high-sensitivity piezoresponse force microscopy to show that films as thin as one or two layers of ferroelectric poly(vinylidene fluoride) remain switchable with low voltages. Submicron junctions based on these films display tunnel electroresistance reaching 1,000% at room temperature that is driven by ferroelectric switching and explained by electrostatic effects in a direct tunnelling regime. Our findings provide a path to develop low-cost, large-scale arrays of organic ferroelectric tunnel junctions on silicon or flexible substrates.

  20. High-resolution tunnel fluctuoscopy

    Energy Technology Data Exchange (ETDEWEB)

    Glatz, A.; Varlamov, A. A.; Vinokur, V. M.

    2014-08-01

    Electron tunneling spectroscopy pioneered by Esaki and Giaever offered a powerful tool for studying electronic spectra and density of states (DOS) in superconductors. This led to important discoveries that revealed, in particular, the pseudogap in the tunneling spectrum of superconductors above their critical temperatures. However, the phenomenological approach of Giaever and Megerle does not resolve the fine structure of low-bias behavior carrying significant information about electron scattering, interactions, and decoherence effects. Here we construct a complete microscopic theory of electron tunneling into a superconductor in the fluctuation regime. We reveal a non-trivial low-energy anomaly in tunneling conductivity due to Andreev-like reflections of injected electrons from superconducting fluctuations. Our findings enable real-time observation of fluctuating Cooper pairs dynamics by time-resolved scanning tunneling microscopy measurements and open new horizons for quantitative analysis of the fluctuation electronic spectra of superconductors.

  1. Frequency driven inversion of tunnel magnetoimpedance and observation of positive tunnel magnetocapacitance in magnetic tunnel junctions

    Science.gov (United States)

    Parui, Subir; Ribeiro, Mário; Atxabal, Ainhoa; Bedoya-Pinto, Amilcar; Sun, Xiangnan; Llopis, Roger; Casanova, Fèlix; Hueso, Luis E.

    2016-08-01

    The relevance for modern computation of non-volatile high-frequency memories makes ac-transport measurements of magnetic tunnel junctions (MTJs) crucial for exploring this regime. Here, we demonstrate a frequency-mediated effect in which the tunnel magnetoimpedance reverses its sign in a classical Co/Al2O3/NiFe MTJ, whereas we only observe a gradual decrease in the tunnel magnetophase. Such effects are explained by the capacitive coupling of a parallel resistor and capacitor in the equivalent circuit model of the MTJ. Furthermore, we report a positive tunnel magnetocapacitance effect, suggesting the presence of a spin-capacitance at the two ferromagnet/tunnel-barrier interfaces. Our results are important for understanding spin transport phenomena at the high frequency regime in which the spin-polarized charge accumulation due to spin-dependent penetration depth at the two interfaces plays a crucial role.

  2. Frequency driven inversion of tunnel magnetoimpedance and observation of positive tunnel magnetocapacitance in magnetic tunnel junctions

    Energy Technology Data Exchange (ETDEWEB)

    Parui, Subir, E-mail: s.parui@nanogune.eu, E-mail: l.hueso@nanogune.eu; Ribeiro, Mário; Atxabal, Ainhoa; Llopis, Roger [CIC nanoGUNE, 20018 Donostia-San Sebastian (Spain); Bedoya-Pinto, Amilcar [CIC nanoGUNE, 20018 Donostia-San Sebastian (Spain); Max Planck Institute of Microstructure Physics, D-06120 Halle (Germany); Sun, Xiangnan [CIC nanoGUNE, 20018 Donostia-San Sebastian (Spain); National Center for Nanoscience and Technology, 100190 Beijing (China); Casanova, Fèlix; Hueso, Luis E., E-mail: s.parui@nanogune.eu, E-mail: l.hueso@nanogune.eu [CIC nanoGUNE, 20018 Donostia-San Sebastian (Spain); IKERBASQUE, Basque Foundation for Science, 48011 Bilbao (Spain)

    2016-08-01

    The relevance for modern computation of non-volatile high-frequency memories makes ac-transport measurements of magnetic tunnel junctions (MTJs) crucial for exploring this regime. Here, we demonstrate a frequency-mediated effect in which the tunnel magnetoimpedance reverses its sign in a classical Co/Al{sub 2}O{sub 3}/NiFe MTJ, whereas we only observe a gradual decrease in the tunnel magnetophase. Such effects are explained by the capacitive coupling of a parallel resistor and capacitor in the equivalent circuit model of the MTJ. Furthermore, we report a positive tunnel magnetocapacitance effect, suggesting the presence of a spin-capacitance at the two ferromagnet/tunnel-barrier interfaces. Our results are important for understanding spin transport phenomena at the high frequency regime in which the spin-polarized charge accumulation due to spin-dependent penetration depth at the two interfaces plays a crucial role.

  3. Difference flow and electrical conductivity measurements at the Olkiluoto site in Eurajoki, drillholes OL-KR54, OL-KR55, OL-KR55B and OL-KR47B

    Energy Technology Data Exchange (ETDEWEB)

    Komulainen, J.; Poellaenen, J.; Hurmerinta, E.; Ripatti, K. [Poeyry Finland Oy, Espoo (Finland)

    2012-04-15

    The Posiva Flow Log, Difference flow method (PFL DIFF) uses a flowmeter that incorporates a flow guide and can be used for relatively quick determinations of hydraulic conductivity and hydraulic head of fractures/fractured zones in drillholes. This report presents the principles of the method and the results of measurements carried out in drillholes OL-KR54, OL-KR55, OL-KR55B and OL-KR47B at the Olkiluoto investigation site between January 2011 and September 2011. The measuring programme employed was the same in all drillholes. The applied section lengths of the flow guide were either 2 m and 0.5 m. Flow into the drillhole or from the drillhole to the bedrock was measured within the section length. The measurements were carried out in both pumped and natural (i.e. un-pumped) conditions. The transmissivity and hydraulic head of zones were calculated from the flow and pressure results. The device used includes a sensor for single point resistance (SPR). SPR was measured in connection with the flow measurements. The electrical conductivity (EC) of fracture-specific water was measured in chosen fractures. Fractures were selected on the basis of the measured flow from fractures into the drillhole. The drillhole flow (flow along the drillhole) was measured in conjunction with drillhole EC measurements. (orig.)

  4. Simulations in quantum tunneling

    Science.gov (United States)

    Smith, Kevin; Blaylock, Guy

    2017-10-01

    We study the timing effects of nonrelativistic wave packet tunneling through a barrier using a numerical simulation readily accessible to an undergraduate audience. We demonstrate that the peak of the transmitted packet can sometimes emerge from the barrier ahead of the peak of an undisturbed wave packet that does not encounter a barrier. Under the right circumstances, this effect can give the appearance that transmission through the barrier occurs at superluminal speeds. We demonstrate that this seemingly paradoxical effect is not all that puzzling. Rather, components from the front of the incoming wave packet are preferentially transmitted, forming a transmitted packet ahead of the average of the incoming wave packet but not ahead of the leading edge of that packet. Our studies also show how the timing depends on barrier height and width, consistent with expectations based on the different energy components of the wave packet.

  5. Tunneling of atoms, nuclei and molecules

    CERN Document Server

    Bertulani, C A

    2015-01-01

    This is a brief review of few relevant topics on tunneling of composite particles and how the coupling to intrinsic and external degrees of freedom affects tunneling probabilities. I discuss the phenomena of resonant tunneling, different barriers seen by subsystems, damping of resonant tunneling by level bunching and continuum effects due to particle dissociation.

  6. Tunnel fire testing and modeling the Morgex North tunnel experiment

    CERN Document Server

    Borghetti, Fabio; Gandini, Paolo; Frassoldati, Alessio; Tavelli, Silvia

    2017-01-01

    This book aims to cast light on all aspects of tunnel fires, based on experimental activities and theoretical and computational fluid dynamics (CFD) analyses. In particular, the authors describe a transient full-scale fire test (~15 MW), explaining how they designed and performed the experimental activity inside the Morgex North tunnel in Italy. The entire organization of the experiment is described, from preliminary evaluations to the solutions found for management of operational difficulties and safety issues. This fire test allowed the collection of different measurements (temperature, air velocity, smoke composition, pollutant species) useful for validating and improving CFD codes and for testing the real behavior of the tunnel and its safety systems during a diesel oil fire with a significant heat release rate. Finally, the fire dynamics are compared with empirical correlations, CFD simulations, and literature measurements obtained in other similar tunnel fire tests. This book will be of interest to all ...

  7. Tunnel Cost-Estimating Methods.

    Science.gov (United States)

    1981-10-01

    8 ae1e 066 c LINING CALCULATES THE LINING COSTS AND THE FORMWORK COST FOR A 982928 ees C TUNNEL OR SHAFT SEGMENT 682636 0066...AD-AIO . 890 ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURGETC F/B 13/13 TUNNEL COST-ESTIMATING METNDS(U) OCT 81 R D BENNETT UNCLASSIFIED WES...TR/L-81-101-3lEEEEEE EIIIl-IIIIIIIu IIIIEIIIEIIIIE llllEEEEllEEEI EEEEEEEEEIIII C EllTE-CHNICAL RGPORT GL-81-10 LI10 TUNNEL COST-ESTIMATING METHODS by

  8. Quantum Tunneling and Complex Trajectories

    Science.gov (United States)

    Meynig, Max; Haggard, Hal

    2017-01-01

    In general, the semiclassical approximation of quantum mechanical tunneling fails to treat tunneling through barriers if real initial conditions and trajectories are used. By analytically continuing classical dynamics to the complex plane the problems encountered in the approximation can be resolved. While, the complex methods discussed here have been previously explored, no one has exhibited an analytically solvable case. The essential features of the complex method will be discussed in the context of a novel, analytically solvable problem. These methods could be useful in quantum gravity, with applications to the tunneling of spacetime geometries.

  9. Tunneling Ionization of Diatomic Molecules

    DEFF Research Database (Denmark)

    Svensmark, Jens Søren Sieg

    2016-01-01

    When a molecule is subject to a strong laser field, there is a probability that an electron can escape, even though the electrons are bound by a large potential barrier. This is possible because electrons are quantum mechanical in nature, and they are therefore able to tunnel through potential...... of tunneling ionizaion of molecules is presented and the results of numerical calculations are shown. One perhaps surprising result is, that the frequently used Born-Oppenheimer approximation breaks down for weak fields when describing tunneling ionization. An analytic theory applicable in the weak-field limit...

  10. Dynamical tunneling theory and experiment

    CERN Document Server

    Keshavamurthy, Srihari

    2011-01-01

    A prominent aspect of quantum theory, tunneling arises in a variety of contexts across several fields of study, including nuclear, atomic, molecular, and optical physics and has led to technologically relevant applications in mesoscopic science. Exploring mechanisms and consequences, Dynamical Tunneling: Theory and Experiment presents the work of international experts who discuss the considerable progress that has been achieved in this arena in the past two decades.Highlights in this volume include:A historical introduction and overview of dynamical tunneling, with case histories ranging from

  11. Free Surface Water Tunnel (FSWT)

    Data.gov (United States)

    Federal Laboratory Consortium — Description: The Free Surface Water Tunnel consists of the intake plenum, the test section and the exit plenum. The intake plenum starts with a perforated pipe that...

  12. Flatback airfoil wind tunnel experiment.

    Energy Technology Data Exchange (ETDEWEB)

    Mayda, Edward A. (University of California, Davis, CA); van Dam, C.P. (University of California, Davis, CA); Chao, David D. (University of California, Davis, CA); Berg, Dale E.

    2008-04-01

    A computational fluid dynamics study of thick wind turbine section shapes in the test section of the UC Davis wind tunnel at a chord Reynolds number of one million is presented. The goals of this study are to validate standard wind tunnel wall corrections for high solid blockage conditions and to reaffirm the favorable effect of a blunt trailing edge or flatback on the performance characteristics of a representative thick airfoil shape prior to building the wind tunnel models and conducting the experiment. The numerical simulations prove the standard wind tunnel corrections to be largely valid for the proposed test of 40% maximum thickness to chord ratio airfoils at a solid blockage ratio of 10%. Comparison of the computed lift characteristics of a sharp trailing edge baseline airfoil and derived flatback airfoils reaffirms the earlier observed trend of reduced sensitivity to surface contamination with increasing trailing edge thickness.

  13. Self-Organizing Tunnel Peers

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Tunneling is an important approach in IPv6 transition techniques. The tunnel broker model provides a way to build virtual IPv6 networks without manual configuration.However, neither it adapts performance variation on the IPv4 infrastructure,nor it is a scalable solution for a wide-area IPv6 networking environment. In this paper, a self-organizing tunnel peer (SOTP)model is presented. Tunnel peers are clustered in the SOTP system so that optimization is scalable. Four primitive operations related to cluster construction - arrest,release,division and death - endow the system with the nature of self-organization.Occurrence and behavior of the operations are decided by criteria on the IPv4 end-to-end performance; hence measurement is an indispensable component of the system. The metabolism of cluster relaxes the requirement to accuracy of measurement and optimization.

  14. The Statistics of Chaotic Tunnelling

    CERN Document Server

    Creagh, S C; Creagh, Stephen C.; Whelan, Niall D.

    2000-01-01

    We discuss the statistics of tunnelling rates in the presence of chaotic classical dynamics. This applies to resonance widths in chaotic metastable wells and to tunnelling splittings in chaotic symmetric double wells. The theory is based on using the properties of a semiclassical tunnelling operator together with random matrix theory arguments about wave function overlaps. The resulting distribution depends on the stability of a specific tunnelling orbit and is therefore not universal. However it does reduce to the universal Porter-Thomas form as the orbit becomes very unstable. For some choices of system parameters there are systematic deviations which we explain in terms of scarring of certain real periodic orbits. The theory is tested in a model symmetric double well problem and possible experimental realisations are discussed.

  15. 5-foot Vertical Wind Tunnel

    Science.gov (United States)

    1932-01-01

    The researcher is sitting above the exit cone of the 5-foot Vertical Wind Tunnel and is examining the new 6-component spinning balance. This balance was developed between 1930 and 1933. It was an important advance in the technology of rotating or rolling balances. As M.J. Bamber and C.H. Zimmerman wrote in NACA TR 456: 'Data upon the aerodynamic characteristics of a spinning airplane may be obtained in several ways; namely, flight tests with full-scale airplanes, flight tests with balanced models, strip-method analysis of wind-tunnel force and moment tests, and wind-tunnel tests of rotating models.' Further, they note: 'Rolling-balance data have been of limited value because it has not been possible to measure all six force and moment components or to reproduce a true spinning condition. The spinning balance used in this investigation is a 6-component rotating balance from which it is possible to obtain wind-tunnel data for any of a wide range of possible spinning conditions.' Bamber and Zimmerman described the balance as follows: 'The spinning balance consists of a balance head that supports the model and contains the force-measuring units, a horizontal turntable supported by streamline struts in the center of the jet and, outside the tunnel, a direct-current driving motor, a liquid tachometer, an air compressor, a mercury manometer, a pair of indicating lamps, and the necessary controls. The balance head is mounted on the turntable and it may be set to give any radius of spin between 0 and 8 inches.' In an earlier report, NACA TR 387, Carl Wenzinger and Thomas Harris supply this description of the tunnel: 'The vertical open-throat wind tunnel of the National Advisory Committee for Aeronautics ... was built mainly for studying the spinning characteristics of airplane models, but may be used as well for the usual types of wind-tunnel tests. A special spinning balance is being developed to measure the desired forces and moments with the model simulating the actual

  16. Submucosal tunneling techniques: current perspectives

    Directory of Open Access Journals (Sweden)

    Kobara H

    2014-04-01

    Full Text Available Hideki Kobara,1 Hirohito Mori,1 Kazi Rafiq,2 Shintaro Fujihara,1 Noriko Nishiyama,1 Maki Ayaki,1 Tatsuo Yachida,1 Tae Matsunaga,1 Johji Tani,1 Hisaaki Miyoshi,1 Hirohito Yoneyama,1 Asahiro Morishita,1 Makoto Oryu,1 Hisakazu Iwama,3 Tsutomu Masaki1 1Department of Gastroenterology and Neurology, 2Department of Pharmacology, 3Life Science Research Center, Faculty of Medicine, Kagawa University, Miki-cho, Kita-Gun, Kagawa, Japan Abstract: Advances in endoscopic submucosal dissection include a submucosal tunneling technique, involving the introduction of tunnels into the submucosa. These tunnels permit safer offset entry into the peritoneal cavity for natural orifice transluminal endoscopic surgery. Technical advantages include the visual identification of the layers of the gut, blood vessels, and subepithelial tumors. The creation of a mucosal flap that minimizes air and fluid leakage into the extraluminal cavity can enhance the safety and efficacy of surgery. This submucosal tunneling technique was adapted for esophageal myotomy, culminating in its application to patients with achalasia. This method, known as per oral endoscopic myotomy, has opened up the new discipline of submucosal endoscopic surgery. Other clinical applications of the submucosal tunneling technique include its use in the removal of gastrointestinal subepithelial tumors and endomicroscopy for the diagnosis of functional and motility disorders. This review suggests that the submucosal tunneling technique, involving a mucosal safety flap, can have potential values for future endoscopic developments. Keywords: submucosal endoscopy, submucosal tunneling method, natural orifice transluminal endoscopic surgery, peroral endoscopic myotomy, gastrointestinal subepithelial tumor, functional and motility disorders

  17. Current noise in tunnel junctions

    Energy Technology Data Exchange (ETDEWEB)

    Frey, Moritz; Grabert, Hermann [Physikalisches Institut, Universitaet Freiburg, Hermann-Herder-Strasse 3, 79104, Freiburg (Germany)

    2017-06-15

    We study current fluctuations in tunnel junctions driven by a voltage source. The voltage is applied to the tunneling element via an impedance providing an electromagnetic environment of the junction. We use circuit theory to relate the fluctuations of the current flowing in the leads of the junction with the voltage fluctuations generated by the environmental impedance and the fluctuations of the tunneling current. The spectrum of current fluctuations is found to consist of three parts: a term arising from the environmental Johnson-Nyquist noise, a term due to the shot noise of the tunneling current and a third term describing the cross-correlation between these two noise sources. Our phenomenological theory reproduces previous results based on the Hamiltonian model for the dynamical Coulomb blockade and provides a simple understanding of the current fluctuation spectrum in terms of circuit theory and properties of the average current. Specific results are given for a tunnel junction driven through a resonator. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. TunnelVision: LHC Tunnel Photogrammetry System for Structural Monitoring

    CERN Document Server

    Fallas, William

    2014-01-01

    In this document an algorithm to detect deformations in the LHC Tunnel of CERN is presented. It is based on two images, one represents the ideal state of the tunnel and the other one the actual state. To find the differences between both, the algorithm is divided in three steps. First, an image enhancement is applied to make easier the detection. Second, two different approaches to reduce noise are applied to one or both images. And third, it is defined a group of characteristics about the type of deformation desired to detect. Finally, the conclusions show the effectiveness of the algorithm in the experimental results.

  19. Design of tunneling injection quantum dot lasers

    Institute of Scientific and Technical Information of China (English)

    JIA Guo-zhi; YAO Jiang-hong; SHU Yong-chun; WANG Zhan-guo

    2007-01-01

    To implement high quality tunneling injection quantum dot lasers,effects of primary factors on performance of the tunneling injection quantum dot lasers were investigated. The considered factors were tunneling probability,tunneling time and carriers thermal escape time from the quantum well. The calculation results show that with increasing of the ground-state energy level in quantum well,the tunneling probability increases and the tunneling time decreases,while the thermal escape time decreases because the ground-state energy levelis shallower. Longitudinal optical phonon-assisted tunneling can be an effective method to solve the problem that both the tunneling time and the thermal escape time decrease simultaneously with the ground-state energy level increasing in quantum well.

  20. Tunneling field effect transistor technology

    CERN Document Server

    Chan, Mansun

    2016-01-01

    This book provides a single-source reference to the state-of-the art in tunneling field effect transistors (TFETs). Readers will learn the TFETs physics from advanced atomistic simulations, the TFETs fabrication process and the important roles that TFETs will play in enabling integrated circuit designs for power efficiency. · Provides comprehensive reference to tunneling field effect transistors (TFETs); · Covers all aspects of TFETs, from device process to modeling and applications; · Enables design of power-efficient integrated circuits, with low power consumption TFETs.

  1. Quantum Cosmology for Tunneling Universes

    CERN Document Server

    Kim, Sang Pyo

    2004-01-01

    In a quantum cosmological model consisting of a Euclidean region and a Lorentzian region, Hartle-Hawking's no-bounary wave function, and Linde's wave function and Vilenkin's tunneling wave function are briefly described and compared with each other. We put a particular emphasis on semiclassical gravity from quantum cosmology and compare it with the conventional quantum field theory in curved spacetimes. Finally, we discuss the recent debate on catastrophic particle production in the tunneling universe between Rubakov and Vilenkin within the semiclassical gravity.

  2. Spin tunnelling in mesoscopic systems

    Indian Academy of Sciences (India)

    Anupam Garg

    2001-02-01

    We study spin tunnelling in molecular magnets as an instance of a mesoscopic phenomenon, with special emphasis on the molecule Fe8. We show that the tunnel splitting between various pairs of Zeeman levels in this molecule oscillates as a function of applied magnetic field, vanishing completely at special points in the space of magnetic fields, known as diabolical points. This phenomena is explained in terms of two approaches, one based on spin-coherent-state path integrals, and the other on a generalization of the phase integral (or WKB) method to difference equations. Explicit formulas for the diabolical points are obtained for a model Hamiltonian.

  3. Tunneling in high-K isomeric decays

    CERN Document Server

    Shizuma, T; Shimizu, Y R

    2002-01-01

    We have systematically investigated highly-K-forbidden transitions observed in the Hf, W and Os region, using the gamma-tunneling model in which low-K and high-k states interact through a process of quantum tunneling. The measured hindrance factors are compared with the values calculated using the gamma-tunneling model. Isotope dependences of gamma-tunneling probabilities particularly for neutron-rich nuclei and the relation to stimulated decays of isomers are discussed. (author)

  4. Drill and blast tunnelling; Konvensjonell drift av tunneler

    Energy Technology Data Exchange (ETDEWEB)

    Roenn, Paal-Egil

    1997-12-31

    This thesis treats drill and blast tunnelling. The rapid technological advance necessitates revised and updated design criteria, quality requirements and quality control. In situ blast experiments were carried out in order to test new methods and improve the basis for calculation and design. The main topics of the experiments were (1) longer rounds and increased drillhole diameter, (2) emulsion slurry as explosives in tunnelling, and (3) electronic detonators in contour blasting. The experiments show that it is technically feasible to blast rounds of up to 8.6 m length. Using current technology, the economical optimum round length is substantially shorter. Dust, low visibility, noise and toxic fumes are occupational environmental strains for the tunnel workers. Several of the environmental factors are strongly influenced by the type of explosives used. For example, emulsion slurry resulted in 4 to 5 times better visibility than Anolit and the concentration of respirable dust and total dust was reduced by 30-50 %. Electronic detonators were tested and found to give a higher percentage of remaining drillholes in the contour than Nonel detonators. The thesis includes a chapter on economic design of hydropower tunnels. 42 refs., 83 figs., 45 tabs.

  5. Fiber coupled ultrafast scanning tunneling microscope

    DEFF Research Database (Denmark)

    Keil, Ulrich Dieter Felix; Jensen, Jacob Riis; Hvam, Jørn Märcher

    1997-01-01

    We report on a scanning tunneling microscope with a photoconductive gate in the tunneling current circuit. The tunneling tip is attached to a coplanar transmission line with an integrated photoconductive switch. The switch is illuminated through a fiber which is rigidly attached to the switch...

  6. Tunnel Face Stability & New CPT Applications

    NARCIS (Netherlands)

    Broere, W.

    2001-01-01

    Nearly all tunnels bored in soft soils have encountered problems with the stability of the tunnel face. In several cases these problems led to an extended stand-still of the boring process. A better understanding of the face stability, and of the soil conditions around the tunnel boring machine, can

  7. A Wind Tunnel Captive Aircraft Testing Technique

    Science.gov (United States)

    1976-04-01

    Flight/Wind Tunnel Correlation of Aircraft Longitudinal Motion ....................................... 14 10. Fright/Wind Tunnel Correlation of...I 2 3 4 5 6 T IME, s e c Figure 9. Flight/wind tunnel correla- tion of aircraft longitudinal motion. ’ D A n ~ v i i i | ~ 0 0 - 4 0

  8. Femtosecond tunneling response of surface plasmon polaritons

    DEFF Research Database (Denmark)

    Keil, Ulrich Dieter Felix; Ha, Taekjip; Jensen, Jacob Riis

    1998-01-01

    We obtain femtosecond (200 fs) time resolution using a scanning tunneling microscope on surface plasmon polaritons (SPPs) generated by two 100 fs laser beams in total internal reflection geometry. The tunneling gap dependence of the signal clearly indicates the tunneling origin of the signal...

  9. The road safety of motorway tunnels.

    NARCIS (Netherlands)

    2009-01-01

    This fact sheet discusses the safety of motorway tunnels in the Netherlands. Broadly speaking, it is not certain whether crashes in the Netherlands are relatively more frequent in tunnels than on open road stretches. However, there are certain factors that increase the risk in tunnels, such as the p

  10. Time tunnels meet warped passages

    CERN Multimedia

    Kushner, David

    2006-01-01

    "Just in time for its 40th anniversary, the classic sci-fi television show "The time tunnel" is out on DVD. The conceit is something every engineer can relate to: a pulled plug. Scientists in an underground lab are working on a secret government experiment in time travel. (1 page)

  11. Tunnel lighting in Europe (abridged).

    NARCIS (Netherlands)

    Schreuder, D.A.

    1972-01-01

    A set of principles embodied in 1971 recommendations of the cie (commission internationale de l'eclairage - international commission on lighting) is beginning to be generally accepted throughout europe, so that it is now possible to speak of a european system of tunnel lighting." the recommendations

  12. The recurrent carpal tunnel syndrome.

    Science.gov (United States)

    Kern, B C; Brock, M; Rudolph, K H; Logemann, H

    1993-01-01

    Sixteen out of 720 patients with carpal tunnel syndrome who had undergone surgery since 1979 were reoperated for a "recurrence" (2.2%). Twelve of these patients had been originally operated on in our department. Thus, our own recurrence rate is 1.7%. Three patients deteriorated following surgery, 6 had an unsatisfactory improvement, and in 7 the symptoms recurred after initial improvement. Eight of the reoperated patients had a predisposing disease (terminal renal insufficiency, insulin-dependent diabetes mellitus, acromegaly). In 10 of the 16 cases the initial operation had been carried out by surgeons in the first three years of training. Reoperation revealed incomplete splitting of the transverse carpal ligament in 10 cases, compression of the median nerve by the scar in 4, injury of the muscular branch in 1, and an anatomical variant as cause of incomplete decompression in 1 patient. "Recurrences" after carpal tunnel surgery are predominantly due to inadequacies of the first procedure. A remarkable number of patients (50%) has predisposing diseases. Interfascicular or epineural neurolysis and complete exposure and neurolysis of the median nerve and its branches is necessary only in cases of recurrence. Their omission at the first surgery does not result in an increased recurrence rate. Our observations indicate that the number of operations for recurrent carpal tunnel syndrome can probably be reduced when the first operation is performed with care and experience. Patients with carpal tunnel syndrome secondary to a systemic disease are particularly at risk.

  13. Introduction to scanning tunneling microscopy

    CERN Document Server

    Chen, C Julian

    2008-01-01

    The scanning tunneling and the atomic force microscope, both capable of imaging individual atoms, were crowned with the Physics Nobel Prize in 1986, and are the cornerstones of nanotechnology today. This is a thoroughly updated version of this 'bible' in the field.

  14. A Seamless Ubiquitous Telehealthcare Tunnel

    Directory of Open Access Journals (Sweden)

    Sao-Jie Chen

    2013-08-01

    Full Text Available Mobile handheld devices are rapidly using to implement healthcare services around the World. Fundamentally, these services utilize telemedicine technologies. A disconnection of a mobile telemedicine system usually results in an interruption, which is embarrassing, and reconnection is necessary during the communication session. In this study, the Stream Control Transmission Protocol (SCTP is adopted to build a stable session tunnel to guarantee seamless switching among heterogeneous wireless communication standards, such as Wi-Fi and 3G. This arrangement means that the telemedicine devices will not be limited by a fixed wireless connection and can switch to a better wireless channel if necessary. The tunnel can transmit plain text, binary data, and video streams. According to the evaluation of the proposed software-based SCTP-Tunnel middleware shown, the performance is lower than anticipated and is slightly slower than a fixed connection. However, the transmission throughput is still acceptable for healthcare professionals in a healthcare enterprise or home care site. It is necessary to build more heterogeneous wireless protocols into the proposed tunnel-switching scheme to support all possible communication protocols. In addition, SCTP is another good choice for promoting communication in telemedicine and healthcare fields.

  15. Tunneling in the SIS Structure

    Science.gov (United States)

    Shukrinov, Yu.; Kohandel, M.

    2000-09-01

    We discuss the effects caused by the layered structure of high temperature superconductors (HTS). We use the layered S-N model to obtain the tunneling current of the SIS structure. The current-voltage characteristic is calculated in the limit cases when dI/dV is proportional to the state density of HTS.

  16. Installation in the SPS tunnel

    CERN Multimedia

    1974-01-01

    The SPS tunnel is 6910 m in circumference and has a cross section of 4 m inner diameter. It is situated at an elevation of 400 m above sea level at a depth below the surface varying between 23 and 65 m. Its walls are lined with a concrete shell of about 30 cm thickness. See also 7410043X

  17. Travelling inside the SPS tunnel

    CERN Multimedia

    1974-01-01

    The golf cart proved to be a very useful form of transport around the 7 km circumference of the machine. It could carry four passengers and pull light equipment in its trailer. Here Peter Zettwoch is the driver along a mock-up tunnel for installation tests. (see photo 7401011X and Photo Archive 7401018)

  18. Earth Pressure on Tunnel Crown

    DEFF Research Database (Denmark)

    Andersen, Lars

    Two different analyses have been carried out in order to find the vertical earth pressure, or overburden pressure, at the crown of a tunnel going through a dike. Firstly, a hand calculation is performed using a simple dispersion of the stresses over depth. Secondly, the finite‐element program...

  19. Earth Pressure on Tunnel Crown

    DEFF Research Database (Denmark)

    Andersen, Lars

    Two different analyses have been carried out in order to find the vertical earth pressure, or overburden pressure, at the crown of a tunnel going through a dike. Firstly, a hand calculation is performed using a simple dispersion of the stresses over depth. Secondly, the finite‐element program...

  20. Josephson tunnel junction microwave attenuator

    DEFF Research Database (Denmark)

    Koshelets, V. P.; Shitov, S. V.; Shchukin, A. V.

    1993-01-01

    A new element for superconducting electronic circuitry-a variable attenuator-has been proposed, designed, and successfully tested. The principle of operation is based on the change in the microwave impedance of a superconductor-insulator-superconductor (SIS) Josephson tunnel junction when dc bias...

  1. Inelastic scattering in resonant tunneling

    DEFF Research Database (Denmark)

    Wingreen, Ned S.; Jacobsen, Karsten Wedel; Wilkins, John W.

    1989-01-01

    The exact resonant-tunneling transmission probability for an electron interacting with phonons is presented in the limit that the elastic coupling to the leads is independent of energy. The phonons produce transmission sidebands but do not affect the integrated transmission probability or the esc...

  2. Towards implementation of spent nuclear fuel management in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Eero, Patrakka

    2007-07-01

    The final disposal of spent fuel from the Finnish nuclear power plants will be implemented by Posiva Oy, a company owned jointly by the two nuclear power producers Fortum Oyj and Teollisuuden Voima Oy. Preparations for nuclear waste management were started already in the 1970s. Potential sites for the disposal of spent fuel were screened in the 1980s, followed by detailed site investigations in the 1990s. In May 2001, the Finnish Parliament ratified the Decision-in-Principle that was a prerequisite for the selection of Olkiluoto as the site of the final disposal facility. The disposal project has progressed to the next stage -- constructing an underground characterization facility, known as ONKALO, at Olkiluoto, which has also been designed to serve as an access route to the repository when constructed. Work on the entire final disposal project is progressing so that disposal can commence in 2020. ONKALO will be used to obtain further information for the repository design, and it will also enable final disposal technology to be tested under actual conditions. Once ONKALO has been completed, work will start on building the encapsulation plant and final disposal repository in the 2010s. (auth)

  3. Tunnel widening in anterior cruciate ligament reconstruction

    DEFF Research Database (Denmark)

    Clatworthy, M G; Annear, P; Bulow, J U

    1999-01-01

    .1% in the patella tendon group (P = film measurements. Tunnel widening did not correlate with the clinical findings, knee scores, KT-1000 or isokinetic muscle strength. Tunnel widening is marked in the hamstring group. Tunnel widening does not correlate with instability......We report a prospective series evaluating the incidence and degree of tunnel widening in a well-matched series of patients receiving a hamstring or patella tendon graft for anterior cruciate ligament (ACL) deficiency. We correlated tunnel widening with clinical factors, knee scores, KT-1000...

  4. An Entropic Formulation of Tunneling Time

    CERN Document Server

    Demir, Durmus A

    2015-01-01

    Quantum tunneling governs numerous phenomena in biology, chemistry, physics and technology. Tunneling time, formulated in various different forms due to the absence of a time operator in quantum theory, has been measured recently in experiments based on the attoclock in ultrafast laser ionization of Helium atoms [A.~Landsman {\\it et al.}, Optica {\\bf 1}, 343 (2014)]. The experiment performs a refined measurement with which no tunneling time formula in the literature exhibits adequate congruence. Here we show that, entropic considerations lead to a real tunneling time which shows remarkable agreement with the experimental data and stays always subluminal. Indeed, with phase space volume setting the number of microstates for a single evanescing particle in a state of definite momentum consistent with energy conservation, one is naturally led to a statistical description for quantum tunneling in which thermal energy sets the tunneling time. This entropic tunneling time is rather general and might also be extende...

  5. Tunneling Flight Time, Chemistry, and Special Relativity.

    Science.gov (United States)

    Petersen, Jakob; Pollak, Eli

    2017-08-15

    Attosecond ionization experiments have not resolved the question "What is the tunneling time?". Different definitions of tunneling time lead to different results. Second, a zero tunneling time for a material particle suggests that the nonrelativistic theory includes speeds greater than the speed of light. Chemical reactions, occurring via tunneling, should then not be considered in terms of a nonrelativistic quantum theory calling into question quantum dynamics computations on tunneling reactions. To answer these questions, we define a new experimentally measurable paradigm, the tunneling flight time, and show that it vanishes for scattering through an Eckart or a square barrier, irrespective of barrier length or height, generalizing the Hartman effect. We explain why this result does not lead to experimental measurement of speeds greater than the speed of light. We show that this tunneling is an incoherent process by comparing a classical Wigner theory with exact quantum mechanical computations.

  6. MANAGEMENT OF TUNNELS ON THE ZAGREB – MACELJ MOTORWAY IN THE COURSE OF TUNNELS EXPLOITATION

    Directory of Open Access Journals (Sweden)

    Zvonimir Deković

    2012-12-01

    Full Text Available he paper focuses on the features of management of tunnels on the Zagreb-Macelj motorway. Management of tunnels is represented trough public-private partnership model that is applied on the Zagreb-Macelj motorway. In the course of tunnel operation and maintenance in the first five years of tunnels exploitation, the emphasis is put on the maintenance of the tunnel equipment systems. Tunnels as part of the motorway alignment are the most demanding facilities for maintaining appropriate safety and operational level in order to rich continuous availability providing safe and quality of service to the motorway users. The goal of the tunnel operation and maintenance is to ensure undisturbed and safe traffic flow through the tunnels by keeping the tunnel at the normal functional conditions.

  7. In-Tunnel Blast Pressure Empirical Formulas for Detonations External, Internal and at the Tunnel Entrance

    Institute of Scientific and Technical Information of China (English)

    LI Xiudi; ZHENG Yingren

    2006-01-01

    In order to define the loading on protective doors of an underground tunnel,the exact knowledge of the blast propagation through tunnels is needed.Thirty-three scale high-explosive tests are conducted to obtain in-tunnel blast pressure for detonations external,internal and at the tunnel entrance.The cross section of the concrete model tunnel is 0.67 m2.Explosive charges of TNT,ranging in mass from 400 g to 4 600 g,are detonated at various positions along the central axis of the model tunnel.Blast gages are flush-installed in the interior surface of the tunnel to record side-on blast pressure as it propagates down the tunnel.The engineering empirical formulas for predicting blast peak pressure are evaluated,and are found to be reasonably accurate for in-tunnel pressure prediction.

  8. Resonant tunnel magnetoresistance in a double magnetic tunnel junction

    KAUST Repository

    Useinov, Arthur

    2011-08-09

    We present quasi-classical approach to calculate a spin-dependent current and tunnel magnetoresistance (TMR) in double magnetic tunnel junctions (DMTJ) FML/I/FMW/I/FMR, where the magnetization of the middle ferromagnetic metal layer FMW can be aligned parallel or antiparallel with respect to the fixed magnetizations of the left FML and right FMR ferromagnetic electrodes. The transmission coefficients for components of the spin-dependent current, and TMR are calculated as a function of the applied voltage. As a result, we found a high resonant TMR. Thus, DMTJ can serve as highly effective magnetic nanosensor for biological applications, or as magnetic memory cells by switching the magnetization of the inner ferromagnetic layer FMW.© Springer Science+Business Media, LLC 2011.

  9. Wildlife Tunnel Enhances Population Viability

    Directory of Open Access Journals (Sweden)

    Rodney van der Ree

    2009-12-01

    Full Text Available Roads and traffic are pervasive components of landscapes throughout the world: they cause wildlife mortality, disrupt animal movements, and increase the risk of extinction. Expensive engineering solutions, such as overpasses and tunnels, are increasingly being adopted to mitigate these effects. Although some species readily use such structures, their success in preventing population extinction remains unknown. Here, we use population viability modeling to assess the effectiveness of tunnels for the endangered Mountain Pygmy-possum (Burramys parvus in Australia. The underpasses reduced, but did not completely remove, the negative effects of a road. The expected minimum population size of a "reconnected" population remained 15% lower than that of a comparable "undivided" population. We propose that the extent to which the risk of extinction decreases should be adopted as a measure of effectiveness of mitigation measures and that the use of population modeling become routine in these evaluations.

  10. Seismic scanning tunneling macroscope - Theory

    KAUST Repository

    Schuster, Gerard T.

    2012-09-01

    We propose a seismic scanning tunneling macroscope (SSTM) that can detect the presence of sub-wavelength scatterers in the near-field of either the source or the receivers. Analytic formulas for the time reverse mirror (TRM) profile associated with a single scatterer model show that the spatial resolution limit to be, unlike the Abbe limit of λ/2, independent of wavelength and linearly proportional to the source-scatterer separation as long as the point scatterer is in the near-field region; if the sub-wavelength scatterer is a spherical impedance discontinuity then the resolution will also be limited by the radius of the sphere. Therefore, superresolution imaging can be achieved as the scatterer approaches the source. This is analogous to an optical scanning tunneling microscope that has sub-wavelength resolution. Scaled to seismic frequencies, it is theoretically possible to extract 100 Hz information from 20 Hz data by imaging of near-field seismic energy.

  11. Single-contact tunneling thermometry

    Energy Technology Data Exchange (ETDEWEB)

    Maksymovych, Petro

    2016-02-23

    A single-contact tunneling thermometry circuit includes a tunnel junction formed between two objects. Junction temperature gradient information is determined based on a mathematical relationship between a target alternating voltage applied across the junction and the junction temperature gradient. Total voltage measured across the junction indicates the magnitude of the target alternating voltage. A thermal gradient is induced across the junction. A reference thermovoltage is measured when zero alternating voltage is applied across the junction. An increasing alternating voltage is applied while measuring a thermovoltage component and a DC rectification voltage component created by the applied alternating voltage. The target alternating voltage is reached when the thermovoltage is nullified or doubled by the DC rectification voltage depending on the sign of the reference thermovoltage. Thermoelectric current and current measurements may be utilized in place of the thermovoltage and voltage measurements. The system may be automated with a feedback loop.

  12. Tunneling magnetoresistance in Si nanowires

    Science.gov (United States)

    Montes, E.; Rungger, I.; Sanvito, S.; Schwingenschlögl, U.

    2016-11-01

    We investigate the tunneling magnetoresistance of small diameter semiconducting Si nanowires attached to ferromagnetic Fe electrodes, using first principles density functional theory combined with the non-equilibrium Green’s functions method for quantum transport. Silicon nanowires represent an interesting platform for spin devices. They are compatible with mature silicon technology and their intrinsic electronic properties can be controlled by modifying the diameter and length. Here we systematically study the spin transport properties for neutral nanowires and both n and p doping conditions. We find a substantial low bias magnetoresistance for the neutral case, which halves for an applied voltage of about 0.35 V and persists up to 1 V. Doping in general decreases the magnetoresistance, as soon as the conductance is no longer dominated by tunneling.

  13. Tunneling magnetoresistance in Si nanowires

    KAUST Repository

    Montes Muñoz, Enrique

    2016-11-09

    We investigate the tunneling magnetoresistance of small diameter semiconducting Si nanowires attached to ferromagnetic Fe electrodes, using first principles density functional theory combined with the non-equilibrium Green\\'s functions method for quantum transport. Silicon nanowires represent an interesting platform for spin devices. They are compatible with mature silicon technology and their intrinsic electronic properties can be controlled by modifying the diameter and length. Here we systematically study the spin transport properties for neutral nanowires and both n and p doping conditions. We find a substantial low bias magnetoresistance for the neutral case, which halves for an applied voltage of about 0.35 V and persists up to 1 V. Doping in general decreases the magnetoresistance, as soon as the conductance is no longer dominated by tunneling.

  14. Dissipative Effect and Tunneling Time

    Directory of Open Access Journals (Sweden)

    Samyadeb Bhattacharya

    2011-01-01

    Full Text Available The quantum Langevin equation has been studied for dissipative system using the approach of Ford et al. Here, we have considered the inverted harmonic oscillator potential and calculated the effect of dissipation on tunneling time, group delay, and the self-interference term. A critical value of the friction coefficient has been determined for which the self-interference term vanishes. This approach sheds new light on understanding the ion transport at nanoscale.

  15. AUTONOMOUS ROBOTIC INSPECTION IN TUNNELS

    OpenAIRE

    E. Protopapadakis; Stentoumis, C.; Doulamis, N.; A. Doulamis; Loupos, K.; Makantasis, K.; Kopsiaftis, G.; Amditis, A.

    2016-01-01

    In this paper, an automatic robotic inspector for tunnel assessment is presented. The proposed platform is able to autonomously navigate within the civil infrastructures, grab stereo images and process/analyse them, in order to identify defect types. At first, there is the crack detection via deep learning approaches. Then, a detailed 3D model of the cracked area is created, utilizing photogrammetric methods. Finally, a laser profiling of the tunnel’s lining, for a narrow region clos...

  16. Variable density turbulence tunnel facility

    Science.gov (United States)

    Bodenschatz, E.; Bewley, G. P.; Nobach, H.; Sinhuber, M.; Xu, H.

    2014-09-01

    The Variable Density Turbulence Tunnel at the Max Planck Institute for Dynamics and Self-Organization in Göttingen, Germany, produces very high turbulence levels at moderate flow velocities, low power consumption, and adjustable kinematic viscosity between 10-4 m2/s and 10-7 m2/s. The Reynolds number can be varied by changing the pressure or flow rate of the gas or by using different non-flammable gases including air. The highest kinematic viscosities, and hence lowest Reynolds numbers, are reached with air or nitrogen at 0.1 bar. To reach the highest Reynolds numbers the tunnel is pressurized to 15 bars with the dense gas sulfur hexafluoride (SF6). Turbulence is generated at the upstream ends of two measurement sections with grids, and the evolution of this turbulence is observed as it moves down the length of the sections. We describe the instrumentation presently in operation, which consists of the tunnel itself, classical grid turbulence generators, and state-of-the-art nano-fabricated hot-wire anemometers provided by Princeton University [M. Vallikivi, M. Hultmark, S. C. C. Bailey, and A. J. Smits, Exp. Fluids 51, 1521 (2011)]. We report measurements of the characteristic scales of the flow and of turbulent spectra up to Taylor Reynolds number Rλ ≈ 1600, higher than any other grid-turbulence experiment. We also describe instrumentation under development, which includes an active grid and a Lagrangian particle tracking system that moves down the length of the tunnel with the mean flow. In this configuration, the properties of the turbulence are adjustable and its structure is resolvable up to Rλ ≈ 8000.

  17. Apparent tunneling in chemical reactions

    DEFF Research Database (Denmark)

    Henriksen, Niels Engholm; Hansen, Flemming Yssing; Billing, G. D.

    2000-01-01

    A necessary condition for tunneling in a chemical reaction is that the probability of crossing a barrier is non-zero, when the energy of the reactants is below the potential energy of the barrier. Due to the non-classical nature (i.e, momentum uncertainty) of vibrational states this is, however, ...... to the high momentum tail of the initial vibrational state of nitrogen, allowing for amplitude to cross over the barrier. (C) 2000 Elsevier Science B.V. All rights reserved....

  18. Electrodiagnosis of carpal tunnel syndrome.

    Science.gov (United States)

    Wang, Leilei

    2013-02-01

    This article discusses the historical aspects related to the understanding of carpal tunnel syndrome (CTS) and its diagnosis, highlighting observations about this disease that have yet to be challenged. This is followed by a discussion regarding the use of electrodiagnostic testing as a diagnostic tool for CTS, as well as the author's approach to making the diagnosis of CTS. Finally, conclusions about future directions in the diagnosis and treatment of this disorder are presented.

  19. Digging the CNGS decay tunnel

    CERN Multimedia

    Patrice Loiez

    2002-01-01

    Products of the collision between a proton beam and a graphite target will pass through a horn containing an electric field that will produce a focused beam. These particles will decay into muon neutrinos within the tunnel that is being constructed in these images. The neutrinos will then travel 730 km to Gran Sasso in Italy where huge detectors will observe the beam to study a process called neutrino oscillation.

  20. Autonomous Robotic Inspection in Tunnels

    Science.gov (United States)

    Protopapadakis, E.; Stentoumis, C.; Doulamis, N.; Doulamis, A.; Loupos, K.; Makantasis, K.; Kopsiaftis, G.; Amditis, A.

    2016-06-01

    In this paper, an automatic robotic inspector for tunnel assessment is presented. The proposed platform is able to autonomously navigate within the civil infrastructures, grab stereo images and process/analyse them, in order to identify defect types. At first, there is the crack detection via deep learning approaches. Then, a detailed 3D model of the cracked area is created, utilizing photogrammetric methods. Finally, a laser profiling of the tunnel's lining, for a narrow region close to detected crack is performed; allowing for the deduction of potential deformations. The robotic platform consists of an autonomous mobile vehicle; a crane arm, guided by the computer vision-based crack detector, carrying ultrasound sensors, the stereo cameras and the laser scanner. Visual inspection is based on convolutional neural networks, which support the creation of high-level discriminative features for complex non-linear pattern classification. Then, real-time 3D information is accurately calculated and the crack position and orientation is passed to the robotic platform. The entire system has been evaluated in railway and road tunnels, i.e. in Egnatia Highway and London underground infrastructure.

  1. Quantum Tunneling Affects Engine Performance.

    Science.gov (United States)

    Som, Sibendu; Liu, Wei; Zhou, Dingyu D Y; Magnotti, Gina M; Sivaramakrishnan, Raghu; Longman, Douglas E; Skodje, Rex T; Davis, Michael J

    2013-06-20

    We study the role of individual reaction rates on engine performance, with an emphasis on the contribution of quantum tunneling. It is demonstrated that the effect of quantum tunneling corrections for the reaction HO2 + HO2 = H2O2 + O2 can have a noticeable impact on the performance of a high-fidelity model of a compression-ignition (e.g., diesel) engine, and that an accurate prediction of ignition delay time for the engine model requires an accurate estimation of the tunneling correction for this reaction. The three-dimensional model includes detailed descriptions of the chemistry of a surrogate for a biodiesel fuel, as well as all the features of the engine, such as the liquid fuel spray and turbulence. This study is part of a larger investigation of how the features of the dynamics and potential energy surfaces of key reactions, as well as their reaction rate uncertainties, affect engine performance, and results in these directions are also presented here.

  2. Pharmacotherapy of carpal tunnel syndrome.

    Science.gov (United States)

    de Pablo, Paola; Katz, Jeffrey N

    2003-06-01

    Carpal tunnel syndrome (CTS) is the most common peripheral nerve entrapment syndrome. CTS is a compression neuropathy caused by elevated pressure in the carpal tunnel. CTS has the potential to substantially limit performance of activities of daily living for some individuals. The goal of therapy for CTS is to improve symptoms and reduce signs of the disease, as well as prevent progression and loss of hand function. There are several treatment alternatives to relieve the pressure on the median nerve, both surgical and conservative. The most common measures employed in the initial treatment of CTS are NSAIDs, local and systemic corticosteroids, diuretics and pyridoxine. However, CTS treatment usually includes a combination of pharmacotherapy with other strategies such as splinting and activity modification. Injections of corticosteroids into the carpal tunnel are often employed for cases not responding to conservative treatment. Surgery is superior to conservative therapies for most persistently symptomatic patients. The aim of this paper is to review the pharmacological agents used for relieving the symptoms of CTS.

  3. Confocal Annular Josephson Tunnel Junctions

    Science.gov (United States)

    Monaco, Roberto

    2016-09-01

    The physics of Josephson tunnel junctions drastically depends on their geometrical configurations and here we show that also tiny geometrical details play a determinant role. More specifically, we develop the theory of short and long annular Josephson tunnel junctions delimited by two confocal ellipses. The behavior of a circular annular Josephson tunnel junction is then seen to be simply a special case of the above result. For junctions having a normalized perimeter less than one, the threshold curves in the presence of an in-plane magnetic field of arbitrary orientations are derived and computed even in the case with trapped Josephson vortices. For longer junctions, a numerical analysis is carried out after the derivation of the appropriate motion equation for the Josephson phase. We found that the system is modeled by a modified and perturbed sine-Gordon equation with a space-dependent effective Josephson penetration length inversely proportional to the local junction width. Both the fluxon statics and dynamics are deeply affected by the non-uniform annulus width. Static zero-field multiple-fluxon solutions exist even in the presence of a large bias current. The tangential velocity of a traveling fluxon is not determined by the balance between the driving and drag forces due to the dissipative losses. Furthermore, the fluxon motion is characterized by a strong radial inward acceleration which causes electromagnetic radiation concentrated at the ellipse equatorial points.

  4. Variable Density Turbulence Tunnel Facility

    CERN Document Server

    Bewley, Gregory P; Sinhuber, Michael; Xu, Haitao; Bodenschatz, Eberhard

    2014-01-01

    The Variable Density Turbulence Tunnel (VDTT) at the Max Planck Institute for Dynamics and Self-Organization in G\\"ottingen, Germany produces very high turbulence levels at moderate flow velocities, low power consumption and adjustable kinematic viscosity. To reach the highest Reynolds number, the tunnel can be filled and pressurized up to 15 bar with the dense gas sulfur hexafluoride (SF$_6$). The Reynolds number can be varied by changing the pressure or flow rate of the gas or by using different non-flammable gases including air. Turbulence is generated at the upstream ends of two measurement sections with grids, and the evolution of this turbulence is observed as it moves down the length of the sections. We describe the instrumentation presently in operation, which consists of the tunnel itself, classical grid turbulence generators, and state-of-the-art nano-fabricated hot-wire anemometers provided by Princeton University [Vallikivi et al. (2011) Exp. Fluids 51, 1521]. We report measurements of the charact...

  5. Tunneling Dynamics Between Atomic Bright Solitons

    CERN Document Server

    Zhao, Li-Chen; Yang, Zhan-Ying; Yang, Wen-Li

    2016-01-01

    We investigate tunneling behavior between two bright solitons in a Bose-Einstein condensate with attractive contact interactions between atoms. The explicit tunneling properties including tunneling particles and oscillation period are described analytically, which indicates that the periodic tunneling form is a nonlinear Josephson type oscillation. The results suggest that the breathing behavior of solitons comes from the tunneling mechanism in an effective double-well potential, which is quite different from the modulational instability mechanism for Akhmediev breather and K-M breather. Furthermore, we obtain a phase diagram for two soliton interaction which admits tunneling property, particle-like property, interference property, and a resonant interaction case. The explicit conditions for them are clarified based on the defined critical distance $d_c$ and spatial interference period $D$.

  6. Investigation into scanning tunnelling luminescence microscopy

    CERN Document Server

    Manson-Smith, S K

    2001-01-01

    This work reports on the development of a scanning tunnelling luminescence (STL) microscope and its application to the study of Ill-nitride semiconductor materials used in the production of light emitting devices. STL microscopy is a technique which uses the high resolution topographic imaging capabilities of the scanning tunnelling microscope (STM) to generate high resolution luminescence images. The STM tunnelling current acts as a highly localised source of electrons (or holes) which generates luminescence in certain materials. Light generated at the STM tunnelling junction is collected concurrently with the height variation of the tunnelling probe as it is scanned across a sample surface, producing simultaneous topographic and luminescence images. Due to the very localised excitation source, high resolution luminescence images can be obtained. Spectroscopic resolution can be obtained by using filters. Additionally, the variation of luminescence intensity with tunnel current and with bias voltage can provi...

  7. Tunnel design considering stress release effect

    Institute of Scientific and Technical Information of China (English)

    Van-hung DAO

    2009-01-01

    In tunnel design,the determination of installation time and the stiffness of supporting structures is very important to the tunnel stability.This study used the convergence-confinement method to determine the stress and displacement of the tunnel while considering the counter-pressure curve of the ground base,the stress release effect,and the interaction between the tunnel lining and the rock surrounding the tunnel chamber.The results allowed for the determination of the installation time,distribution and strength of supporting structures.This method was applied to the intake tunnel in the Ban Ve Hydroelectric Power Plant,in Nghe An Province,Vietnam.The results show that when a suitable displacement u0 ranging from 0.0865 m to 0.0919 m occurrs,we can install supporting structures that satisfy the stability and economical requirements.

  8. Geophysical drillhole logging and optical imaging of the drillholes OL-KR43, OL-KR44, OL-KR44B, OL-KR45, OL-KR45B, OL-KR46, OL-KR46B, OL-KR47, OL-KR47B and OL-KR48, at Olkiluoto 2007 and 2008

    Energy Technology Data Exchange (ETDEWEB)

    Tarvainen, A.-M. (Suomen Malmi OY, Espoo (Finland)); Heikkinen, E. (Poeyry Environment Oy (Finland))

    2008-09-15

    Suomen Malmi Oy conducted geophysical drillhole logging and optical imaging of the drillholes OL-KR43, OL-KR44, OL-KR44B, OL-KR45, OL-KR45B, OL-KR46, OL-KR46B, OL-KR47, OL-KR47B and OL-KR48 at the Olkiluoto site in Eurajoki during December 2007, May 2008. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The assignment included the field work and data processing. The report describes field operation, equipment as well as processing procedures and shows the obtained results and an analysis of their quality in the appendices. The raw and processed data are delivered digitally in WellCAD, PDF and Excel format. (orig.)

  9. RITD – Wind tunnel testing

    Science.gov (United States)

    Haukka, Harri; Harri, Ari-Matti; Aleksashkin, Sergei; Koryanov, Valeri; Schmidt, Walter; Heilimo, Jyri; Finchenko, Valeri; Martynov, Maxim; Ponomarenko, Andrey; Kazakovtsev, Victor; Arruego, Ignazio

    2015-04-01

    An atmospheric re-entry and descent and landing system (EDLS) concept based on inflatable hypersonic decelerator techniques is highly promising for the Earth re-entry missions. We developed such EDLS for the Earth re-entry utilizing a concept that was originally developed for Mars. This EU-funded project is called RITD - Re-entry: Inflatable Technology Development - and it was to assess the bene¬fits of this technology when deploying small payloads from low Earth orbits to the surface of the Earth with modest costs. The principal goal was to assess and develope a preliminary EDLS design for the entire relevant range of aerodynamic regimes expected to be encountered in Earth's atmosphere during entry, descent and landing. The RITD entry and descent system utilizes an inflatable hypersonic decelerator. Development of such system requires a combination of wind tunnel tests and numerical simulations. This included wind tunnel tests both in transsonic and subsonic regimes. The principal aim of the wind tunnel tests was the determination of the RITD damping factors in the Earth atmosphere and recalculation of the results for the case of the vehicle descent in the Mars atmosphere. The RITD mock-up model used in the tests was in scale of 1:15 of the real-size vehicle as the dimensions were (midsection) diameter of 74.2 mm and length of 42 mm. For wind tunnel testing purposes the frontal part of the mock-up model body was manufactured by using a PolyJet 3D printing technology based on the light curing of liquid resin. The tail part of the mock-up model body was manufactured of M1 grade copper. The structure of the mock-up model placed th center of gravity in the same position as that of the real-size RITD. The wind tunnel test program included the defining of the damping factor at seven values of Mach numbers 0.85; 0.95; 1.10; 1.20; 1.25; 1.30 and 1.55 with the angle of attack ranging from 0 degree to 40 degrees with the step of 5 degrees. The damping characteristics of

  10. COMPARISON TRADITIONAL SYSTEMS OF TUNNEL FORMWORK SYSTEM

    OpenAIRE

    ERKAN, İbrahim Hakkı; Yılmaz, Ülkü Sultan; Türken, Hakan

    2011-01-01

    Tunnel formwork systems became the most widespread construction technology preferred in recent years in Turkey due to rapidity and economy. In this study, before all else, a brief information was given about the types and construction techniques of tunnel formwork systems. Then a reinforced concrete building sample was firstly modeled as it was constructed with the tunnel formwork system and secondly modeled as it was formed by a frame system with shear walls constructed by the traditional re...

  11. Quantum tunneling and field electron emission theories

    CERN Document Server

    Liang, Shi-Dong

    2013-01-01

    Quantum tunneling is an essential issue in quantum physics. Especially, the rapid development of nanotechnology in recent years promises a lot of applications in condensed matter physics, surface science and nanodevices, which are growing interests in fundamental issues, computational techniques and potential applications of quantum tunneling. The book involves two relevant topics. One is quantum tunneling theory in condensed matter physics, including the basic concepts and methods, especially for recent developments in mesoscopic physics and computational formulation. The second part is the f

  12. Electromyographic diagnosis of the carpal tunnel syndrome

    Directory of Open Access Journals (Sweden)

    K. Toyonaga

    1978-06-01

    Full Text Available Sensory conduction velocities of the median nerVe were studied from digit to palm and from palm to wrist in normal subjects and in patients with the carpal tunnel syndrome. Definite slowing was noted in the palm to wrist segment, even in the early carpal tunnel syndrome. It was noted that 37% of normal women over 40 years of age had electrophysiological evidence of the carpal tunnel syndrome.

  13. Low-Frequency Electromagnetic Backscattering from Tunnels

    Energy Technology Data Exchange (ETDEWEB)

    Casey, K; Pao, H

    2007-01-16

    Low-frequency electromagnetic scattering from one or more tunnels in a lossy dielectric half-space is considered. The tunnel radii are assumed small compared to the wavelength of the electromagnetic field in the surrounding medium; a tunnel can thus be modeled as a thin scatterer, described by an equivalent impedance per unit length. We examine the normalized backscattering width for cases in which the air-ground interface is either smooth or rough.

  14. Raynaud's syndrome and carpal tunnel syndrome.

    OpenAIRE

    Waller, D G; Dathan, J R

    1985-01-01

    We report three cases of Raynaud's syndrome with digital ischaemic ulceration, in association with carpal tunnel syndrome. In all cases, the aetiology of the Raynaud's syndrome was probably unrelated to the nerve compression. However, symptoms were worse on the side of the median nerve lesion in two patients and worse on the side with the most severe nerve dysfunction in the third; symptoms were relieved by carpal tunnel decompression in two patients. We suggest that carpal tunnel syndrome ma...

  15. Predictive modelling of ferroelectric tunnel junctions

    Science.gov (United States)

    Velev, Julian P.; Burton, John D.; Zhuravlev, Mikhail Ye; Tsymbal, Evgeny Y.

    2016-05-01

    Ferroelectric tunnel junctions combine the phenomena of quantum-mechanical tunnelling and switchable spontaneous polarisation of a nanometre-thick ferroelectric film into novel device functionality. Switching the ferroelectric barrier polarisation direction produces a sizable change in resistance of the junction—a phenomenon known as the tunnelling electroresistance effect. From a fundamental perspective, ferroelectric tunnel junctions and their version with ferromagnetic electrodes, i.e., multiferroic tunnel junctions, are testbeds for studying the underlying mechanisms of tunnelling electroresistance as well as the interplay between electric and magnetic degrees of freedom and their effect on transport. From a practical perspective, ferroelectric tunnel junctions hold promise for disruptive device applications. In a very short time, they have traversed the path from basic model predictions to prototypes for novel non-volatile ferroelectric random access memories with non-destructive readout. This remarkable progress is to a large extent driven by a productive cycle of predictive modelling and innovative experimental effort. In this review article, we outline the development of the ferroelectric tunnel junction concept and the role of theoretical modelling in guiding experimental work. We discuss a wide range of physical phenomena that control the functional properties of ferroelectric tunnel junctions and summarise the state-of-the-art achievements in the field.

  16. Fire safety assessment of tunnel structures

    DEFF Research Database (Denmark)

    Gkoumas, Konstantinos; Giuliani, Luisa; Petrini, Francesco

    2011-01-01

    durability provisions, commitment to environmental aspects, issues of sustainability and safety assurance, for their whole lifecycle. The design for safety of tunnel infrastructures is a multifaceted process, since there are many aspects that need to be accounted for, regarding different aspects (e...... for upgrading fire safety provisions and tunnel management are also important for existing tunnels. In this study, following a brief introduction of issues regarding the above mentioned aspects, the structural performance of a steel rib for a tunnel infrastructure subject to fire is assessed by means...

  17. Surgical efficacy of carpal tunnel release for carpal tunnel syndrome in acromegaly: report of four patients.

    Science.gov (United States)

    Iwasaki, N; Masuko, T; Ishikawa, J; Minami, A

    2005-12-01

    Although carpal tunnel syndrome is frequent in acromegaly, few acromegalics will be encountered by most hand surgeons. This paper considers the treatment of four cases of acromegaly in whom carpal tunnel syndrome arose, to discuss aspects of management of carpal tunnel syndrome in this patient group.

  18. Tunneling electroresistance of MgZnO-based tunnel junctions

    Science.gov (United States)

    Belmoubarik, Mohamed; Al-Mahdawi, Muftah; Obata, Masao; Yoshikawa, Daiki; Sato, Hideyuki; Nozaki, Tomohiro; Oda, Tatsuki; Sahashi, Masashi

    2016-10-01

    We investigated the tunneling electroresistance (TER) in metal/wurtzite-MgZnO/metal junctions for applications in nonvolatile random-access memories. A resistive switching was detected utilizing an electric-field cooling at ±1 V and exhibited a TER ratio of 360%-490% at 2 K. The extracted change in the average barrier height between the two resistance states gave an estimation of the MgZnO electric polarization at 2.5 μC/cm2 for the low-temperature limit. In addition, the temperature-dependent TER ratio and the shift of the localized states energies at the barrier interface supported the ferroelectric behavior of the MgZnO tunnel-barrier. From the first-principles calculations, we found a similar effect of the barrier height change coming from the reversal of ZnO electric polarization. The possibility of using metal electrodes and lower growth temperatures, in addition to the ferroelectric property, make the ZnO-based memory devices suitable for CMOS integration.

  19. More about tunnelling times and superluminal tunnelling (Hartmann effect)

    Energy Technology Data Exchange (ETDEWEB)

    Olkhovsky, V.S. [Ukrainian Akademy of Sciences, Kiev (Ukraine). Inst. for Nuclear Research]|[INFN-Sezione di Catania (Italy); Recami, E. [Bergamo Univ. (Italy). Facolta` di Ingegneria]|[State Univ. at Campinas, Campinas (Brazil); Raciti, F. [Catania Univ. (Italy); Zaichenko, A. [Ukrainian Akademy of Sciences, Kiev (Ukraine). Inst. for Nuclear Reserch

    1995-05-01

    Aims of the present paper are: (i) presenting and analysing the results of various numerical calculations on the penetration and return times <{tau}{sub Pen}>, <{tau}{sub Ret}>, during tunnelling inside a rectangular potential barrier, for various penetration depths x{sub f}; (ii) putting forth and discussing suitable definitions, besides of the mean values, also of the variances (or dispersions) D{sub {tau}T} and D{sub {tau}R} for the time durations of transmission and reflection processes; (iii) mentioning, moreover, that our definition <{tau}{sub T}> for the average transmission time results to constitute an improvement of the ordinary dwell- time formula; (iv) commenting, at last, on the basis of the new numerical results, upon some recent criticism by C.R. Leavens. The paper stresses that numerical evaluations confirm that the approach implied, and implies, the existence of the Hartmann effect: an effect that in these days (due to the theoretical connections between tunnelling and evanescent-wave propagation) is receiving - at Cologne, Berkeley, Florence and Vienna - indirect, but quite interesting, experimental verification.

  20. Tunneling without barriers with gravity

    CERN Document Server

    Kanno, Sugumi; Soda, Jiro

    2012-01-01

    We consider the vacuum decay of the flat Minkowski space to an anti-de Sitter space. We find a one-parameter family of potentials that allow exact, analytical instanton solutions describing tunneling without barriers in the presence of gravity. In the absence of gravity such instantons were found and discussed by Lee and Weinberg more than a quarter of a century ago. The bounce action is also analytically computed. We discuss possible implications of these new instantons to cosmology in the context of the string theory landscape.

  1. Quantum tunnelling in condensed media

    CERN Document Server

    Kagan, Yu

    1992-01-01

    The essays in this book deal with of the problem of quantum tunnelling and related behavior of a microscopic or macroscopic system, which interacts strongly with an ""environment"" - this being some form of condensed matter. The ""system"" in question need not be physically distinct from its environment, but could, for example, be one particular degree of freedom on which attention is focussed, as in the case of the Josephson junction studied in several of the papers. This general problem has been studied in many hundreds, if not thousands, of articles in the literature, in contexts as diverse

  2. Dynamical tunneling in optical cavities

    CERN Document Server

    Hackenbroich, G; Hackenbroich, Gregor; Noeckel, Jens U.

    1998-01-01

    The lifetime of whispering gallery modes in a dielectric cavity with a metallic inclusion is shown to fluctuate by orders of magnitude when size and location of the inclusion are varied. We ascribe these fluctuations to tunneling transitions between resonances quantized in different regions of phase space. This interpretation is confirmed by a comparison of the classical phase space structure with the Husimi distribution of the resonant modes. A model Hamiltonian is introduced that describes the phenomenon and shows that it can be expected in a more general class of systems.

  3. Full-Scale Tunnel (FST)

    Science.gov (United States)

    1929-01-01

    Modified propeller and spinner in Full-Scale Tunnel (FST) model. On June 26, 1929, Elton W. Miller wrote to George W. Lewis proposing the construction of a model of the full-scale tunnel. 'The excellent energy ratio obtained in the new wind tunnel of the California Institute of Technology suggests that before proceeding with our full scale tunnel design, we ought to investigate the effect on energy ratio of such factors as: 1. small included angle for the exit cone; 2. carefully designed return passages of circular section as far as possible, without sudden changes in cross sections; 3. tightness of walls. It is believed that much useful information can be obtained by building a model of about 1/16 scale, that is, having a closed throat of 2 ft. by 4 ft. The outside dimensions would be about 12 ft. by 25 ft. in plan and the height 4 ft. Two propellers will be required about 28 in. in diameter, each to be driven by direct current motor at a maximum speed of 4500 R.P.M. Provision can be made for altering the length of certain portions, particularly the exit cone, and possibly for the application of boundary layer control in order to effect satisfactory air flow. This model can be constructed in a comparatively short time, using 2 by 4 framing with matched sheathing inside, and where circular sections are desired they can be obtained by nailing sheet metal to wooden ribs, which can be cut on the band saw. It is estimated that three months will be required for the construction and testing of such a model and that the cost will be approximately three thousand dollars, one thousand dollars of which will be for the motors. No suitable location appears to exist in any of our present buildings, and it may be necessary to build it outside and cover it with a roof.' George Lewis responded immediately (June 27) granting the authority to proceed. He urged Langley to expedite construction and to employ extra carpenters if necessary. Funds for the model came from the FST project

  4. Metal-Vacuum-Metal Tunneling

    Science.gov (United States)

    1990-11-01

    the unexposed areas was removed with wet etchants. The Al lines formed in this way were 1000 A in width. The field emission mode was also used by...positioned close to the substrate within tunneling range. Whey they ramped the tip voltage to 10-20 volts they formed patterns on the substrate that were...associated with the light induced decomposition of III-V compounds. It is based on well-known work on photo- oxidation and the anisotropic etching of III-V

  5. Computational Wind Tunnel: A Design Tool for Rotorcraft Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Rotorcraft engineers traditionally use the wind tunnel to evaluate and finalize designs. Insufficient correlation between wind tunnel results and flight tests, have...

  6. Transport of dangerous goods through road tunnels

    DEFF Research Database (Denmark)

    Jørgensen, N O; Lacroix, Didier; Amundsen, F.H.;

    1999-01-01

    A paper which describes the work of an OECD research group. The group has suggested a grouping of dangerous materials, a quantitative risk assessment model and a decision support model which should allow tunnel operators to determine if a given material should be allowed throug a given tunnel...

  7. Virtual Processes and Quantum Tunnelling as Fictions

    Science.gov (United States)

    Arthur, Richard T. W.

    2012-01-01

    In this paper it is argued that virtual processes are dispensable fictions. The argument proceeds by a comparison with the phenomenon of quantum tunnelling. Building on an analysis of Levy-Leblond and Balibar, it is argued that, although the phenomenon known as quantum tunnelling certainly occurs and is at the basis of many paradigmatic quantum…

  8. Superconducting Super Collider Laboratory : tunnel boring

    CERN Multimedia

    SSC Media Production

    1999-01-01

    This film will take you down into the tunnel, show you the technology involved in boring the tunnel, and show what the SSC fmeans to the U.S. in terms of scientific discovery, innovative collaborations with industry and stimulating the job base nation-wide.

  9. 78 FR 46117 - National Tunnel Inspection Standards

    Science.gov (United States)

    2013-07-30

    ... September of 2009, and is another activity that FHWA conducted in partnership with AASHTO and NCHRP to... on this measure was a little over 24 months (2.05 years). \\11\\ The definition of a highway tunnel..., including tribally and federally owned tunnels. 650.505 Definitions At-grade Roadway. A definition for at...

  10. A Supermagnetic Tunnel Full of Subatomic Action

    CERN Multimedia

    2008-01-01

    Last year, before the gigantic hadron supercollider at CERN research facility was installed underground, a photographer captured this picture of a 1,950 metric ton tunnel containing giant magnets that will be placed in a tunnel and kept at near-zero temperatures.

  11. Ultrasonographic assessment of carpal tunnel biomechanics

    NARCIS (Netherlands)

    van Doesburg, M.H.M.

    2012-01-01

    In this thesis, we searched for a way to assess flexor tendon and median nerve biomechanics, as well as subsynovial connective tissue thickness (SSCT) in the carpal tunnel with ultrasound, and tried to see if these patterns would give a clue towards understanding the etiology of carpal tunnel syndro

  12. Prediction of swelling rocks strain in tunneling

    Science.gov (United States)

    Parsapour, D.; Fahimifar, A.

    2016-05-01

    Swelling deformations leading to convergence of tunnels may result in significant difficulties during the construction, in particular for long term use of tunnels. By extracting an experimental based explicit analytical solution for formulating swelling strains as a function of time and stress, swelling strains are predicted from the beginning of excavation and during the service life of tunnel. Results obtained from the analytical model show a proper agreement with experimental results. This closed-form solution has been implemented within a numerical program using the finite element method for predicting time-dependent swelling strain around tunnels. Evaluating effects of swelling parameters on time-dependent strains and tunnel shape on swelling behavior around the tunnel according to this analytical solution is considered. The ground-support interaction and consequent swelling effect on the induced forces in tunnel lining is considered too. Effect of delay in lining installation on swelling pressure which acting on the lining and its structural integrity, is also evaluated. A MATLAB code of " SRAP" is prepared and applied to calculate all swelling analysis around tunnels based on analytical solution.

  13. Energy saving in tunnel entrance lighting.

    NARCIS (Netherlands)

    Schreuder, D.A. & Swart, L.

    1993-01-01

    Tunnel entrances may present themselves during the day as a "black hole" in which no details can be perceived. In order to ensure safe and comfortable driving at high speeds, the entrance zone must be lit to a high luminance level. Modern tunnel lighting technology is focused on two aspects: (1

  14. Colloquium: Time-resolved scanning tunneling microscopy

    NARCIS (Netherlands)

    Houselt, van Arie; Zandvliet, Harold J.W.

    2010-01-01

    Scanning tunneling microscopy has revolutionized our ability to image, study, and manipulate solid surfaces on the size scale of atoms. One important limitation of the scanning tunneling microscope (STM) is, however, its poor time resolution. Recording a standard image with a STM typically takes abo

  15. Flow-based detection of DNS tunnels

    NARCIS (Netherlands)

    Ellens, W.; Zuraniewski, P.W.; Sperotto, A.; Schotanus, H.A.; Mandjes, M.; Meeuwissen, H.B.

    2013-01-01

    DNS tunnels allow circumventing access and security policies in firewalled networks. Such a security breach can be misused for activities like free web browsing, but also for command & control traffic or cyber espionage, thus motivating the search for effective automated DNS tunnel detection techniq

  16. Flow-Based Detection of DNS Tunnels

    NARCIS (Netherlands)

    Ellens, W.; Żuraniewski, P.; Sperotto, A.; Schotanus, H.; Mandjes, M.; Meeuwissen, E.

    2013-01-01

    DNS tunnels allow circumventing access and security policies in firewalled networks. Such a security breach can be misused for activities like free web browsing, but also for command & control traffic or cyber espionage, thus motivating the search for effective automated DNS tunnel detection techniq

  17. Spin-valley filter and tunnel magnetoresistance in asymmetrical silicene magnetic tunnel junctions

    Science.gov (United States)

    Wang, Dali; Huang, Zeyuan; Zhang, Yongyou; Jin, Guojun

    2016-05-01

    The spin and valley transports and tunnel magnetoresistance are studied in a silicene-based asymmetrical magnetic tunnel junction consisting of a ferromagnetic tunnel barrier, sandwiched between a ferromagnetic electrode and a normal electrode. For such an asymmetrical silicene junction, a general formulism is established. The numerical results show that the spin-valley resolved conductances strongly depend on the magnetization orientation of the ferromagnetic tunnel barrier, and the fully spin-valley polarized current can be realized by tuning a perpendicularly applied electric field. We also find that the tunnel magnetoresistance in this case can be effectively modified by the external electric field when the conductance is fully spin-valley polarized. In particular, the exchange field in the ferromagnetic electrode can further substantially enhance the tunnel magnetoresistance of the system. Our work provides a practical method for electric and magnetic manipulation of valley/spin polarization and tunnel magnetoresistance.

  18. [Carpal tunnel syndrome. Current approaches].

    Science.gov (United States)

    Kouyoumdjian, J A

    1999-06-01

    A clinical, epidemiological and nerve conduction studies report on carpal tunnel syndrome was done after electrophysiological author's experience on 668 cases and literature review. The median nerve underwent focal (nodal) or segmental demyelination after compression on carpal tunnel, 3-4 distal to wrist fold. The symptomatic complex includes nocturnal hands numbness and paraesthesia, mostly bilateral and between 40-60 years old. Familial cases are described and the gene could encode thick transverse carpal ligament. Anthropomorphic findings could also bring about an additional risk, but with low significance. Magnetic resonance could be a useful tool for selected atypical cases. Conservative treatment and controversies on surgery timing are discussed. Classical conduction studies on median nerve reveal a prolonged distal segmental sensory latency and also on distal motor latency. Increasing sensitivity may be reach using additional methods such as, median mixed mid-palm latency, comparative mid-palm latency median/ulnar, comparative sensory latency median/radial and median/ulnar, inching method from wrist to palm recording on index/middle finger and comparative motor median/ulnar recording on lumbrical/interosseous muscle.

  19. Temporary closure of the tunnel

    CERN Document Server

    Relations with the Host States Service

    2005-01-01

    Owing to major maintenance work, the tunnel linking the various parts of the CERN site will be closed from Monday 4 July to Sunday 24 July 2005 The Host State authorities have given authorisation for persons employed by CERN or the Institutes to travel and for goods belonging to these entities to be transported between the various parts of the site via Gate E (Charles de Gaulle) while this work is being carried out, subject to strict compliance with the Rules for the Use of the Tunnel (see http://dsu.web.cern.ch/dsu/dsum/hsr/DOCUMENTS/8200980415.pdf). Gate E will thus be open between 7.00 a.m. and 7.00 p.m. from Monday to Friday during the period concerned. The rules governing the use of Gate E to enter the Meyrin site between 7.30 a.m. and 9.00 a.m. or to leave the site between 5.00 p.m. and 6.30 p.m. (see http://dsu.web.cern.ch/dsu/dsum/hsr/DOCUMENTS/12222_041027.pdf)) will remain unaffected by this temporary authorisation. Relations with the Host States Service and TS-FM Group

  20. CARPAL TUNNEL SYNDROME IN CYCLISTS

    Science.gov (United States)

    Sousa, Daniel; Sassul, Nicolás

    2017-01-01

    Objectives: About a group of cyclists, professionals / amateurs, Mountain bike, road and triathlon; achieve a good diagnosis of the disease, with a good clinical examination and sectorized according EGM injury evoked potentials. Methods: Clinical examination and accurate test with different signs of pathology. EGM with evocative potential and conduction velocity. Results: After 25 track cyclists, 18 professionals, 22 male and 3 female; for 24 months. Through good clinical examination and EMG. We got that 70% had direct compression injuries Carpal tunnel for poor support on the handlebars. The rest were cervical praxis, by poor body position on the bike, taking cervico very steep angles / dorsal, during competitions or training for more than 2 hrs. Conclusion: A good prevention work with our teacher / cyclist in the position of deposrtista in ciclo simulador. Work in the gym, on tone and elongation of the upper limb. A good EGM, made with a specialist physiatrist. It leads to the correct diagnosis, leads to a good final treatment; which agreed that:* Cervical praxis, had good results with treatment Conservative / FST / vit.B12.* The Carpal tunnel own injuries, treatment was quirúrg. (Open surgery) with subsequent FST / vit..B12 with satisfactory return in time to sporting activity.

  1. IPv6 Tunneling Over IPV4

    Directory of Open Access Journals (Sweden)

    A.Sankara Narayanan

    2012-03-01

    Full Text Available Due to the huge growth of the internet users, mobile users using internet connection makes development and implementation of IPv6 as an alternate solution. IPv6 is a long anticipated upgrade to the internets main communication protocol, which is called IPv4. The current address space provided by IPv4, with only4, 294, 967, 296 addresses. Nowadays IPv6 tunneling over IPv4 are widely used to form the global IPv6 Internet. The IPv6 128-bit address scheme it should provide enough addresses for everyones computer. Tunneling provides a path to use an existing IPv4 to IPv6. This paper describes typical IPv6 tunneling and tunnel brokers deployment in real IP networks. In the deployment of IPv6, it is a well adopted practice that IPv6 networks are interconnected via IPv6 over IPv4 (IPv6/IPv4 tunnels.

  2. Characterization of magnetic tunnel junction test pads

    DEFF Research Database (Denmark)

    Østerberg, Frederik Westergaard; Kjær, Daniel; Nielsen, Peter Folmer

    2015-01-01

    We show experimentally as well as theoretically that patterned magnetic tunnel junctions can be characterized using the current-in-plane tunneling (CIPT) method, and the key parameters, the resistance-area product (RA) and the tunnel magnetoresistance (TMR), can be determined. The CIPT method...... on square tunnel junction pads with varying sizes and analyze the measured data using both the original and the modified CIPT model. Thus, we determine in which sample size range the modified CIPT model is needed to ensure validity of the extracted sample parameters, RA and TMR. In addition, measurements...... as a function of position on a square tunnel junction pad are used to investigate the sensitivity of the measurement results to probe misalignment....

  3. Concept development for HLW disposal research tunnel

    Energy Technology Data Exchange (ETDEWEB)

    Queon, S. K.; Kim, K. S.; Park, J. H.; Jeo, W. J.; Han, P. S. [KAERI, Taejon (Korea, Republic of)

    2003-10-01

    In order to dispose high-level radioactive waste in a geological formation, it is necessary to assess the safety of a disposal concept by excavating a research tunnel in the same geological formation as the host rock mass. The design concept of a research tunnel depends on the actual disposal concept, repository geometry, experiments to be carried at the tunnel, and geological conditions. In this study, analysis of the characteristics of the disposal research tunnel, which is planned to be constructed at KAERI site, calculation of the influence of basting impact on neighbor facilities, and computer simuation for mechanical stability analysis using a three-dimensional code, FLAC3D, had been carried out to develop the design concept of the research tunnel.

  4. Control of tunneling by adapted signals

    CERN Document Server

    Ivlev, B I

    2000-01-01

    Process of quantum tunneling of particles in various physical systems can be effectively controlled even by a weak and slow varying in time electromagnetic signal if to adapt specially its shape to a particular system. During an under-barrier motion of a particle such signal provides a "coherent" assistance of tunneling by the multi-quanta absorption resulting in a strong enhancement of the tunneling probability. The semiclassical approach based on trajectories in the complex time is developed for tunneling in a non-stationary field. Enhancement of tunneling occurs when a singularity of the signal coincides in position at the complex time plane with a singularity of the classical Newtonian trajectory of the particle. The developed theory is also applicable to the over-barrier reflection of particles and to reflection of classical waves (electromagnetic, hydrodynamic, etc.) from a spatially-smooth medium.

  5. Experimental evidence for Wigner's tunneling time

    CERN Document Server

    Camus, Nicolas; Fechner, Lutz; Klaiber, Michael; Laux, Martin; Mi, Yonghao; Hatsagortsyan, Karen Z; Pfeifer, Thomas; Keitel, Christoph H; Moshammer, Robert

    2016-01-01

    Tunneling of a particle through a potential barrier remains one of the most remarkable quantum phenomena. Owing to advances in laser technology, electric fields comparable to those electrons experience in atoms are readily generated and open opportunities to dynamically investigate the process of electron tunneling through the potential barrier formed by the superposition of both laser and atomic fields. Attosecond-time and angstrom-space resolution of the strong laser-field technique allow to address fundamental questions related to tunneling, which are still open and debated: Which time is spent under the barrier and what momentum is picked up by the particle in the meantime? In this combined experimental and theoretical study we demonstrate that for strong-field ionization the leading quantum mechanical Wigner treatment for the time resolved description of tunneling is valid. We achieve a high sensitivity on the tunneling barrier and unambiguously isolate its effects by performing a differential study of t...

  6. Detecting DNS Tunnels Using Character Frequency Analysis

    CERN Document Server

    Born, Kenton

    2010-01-01

    High-bandwidth covert channels pose significant risks to sensitive and proprietary information inside company networks. Domain Name System (DNS) tunnels provide a means to covertly infiltrate and exfiltrate large amounts of information passed network boundaries. This paper explores the possibility of detecting DNS tunnels by analyzing the unigram, bigram, and trigram character frequencies of domains in DNS queries and responses. It is empirically shown how domains follow Zipf's law in a similar pattern to natural languages, whereas tunneled traffic has more evenly distributed character frequencies. This approach allows tunnels to be detected across multiple domains, whereas previous methods typically concentrate on monitoring point to point systems. Anomalies are quickly discovered when tunneled traffic is compared to the character frequency fingerprint of legitimate domain traffic.

  7. Snow and ice blocking of tunnels

    Energy Technology Data Exchange (ETDEWEB)

    Lia, Leif

    1998-12-31

    Hydroelectric power development in cold regions causes much concern about operational reliability and dam safety. This thesis studies the temperature distribution in tunnels by means of air temperature measurements in six tunnel spillways and five diversion tunnels. The measurements lasted for two consecutive winters. The air through flow tunnel is used as it causes cooling of both rock and water. In open spillway tunnels, frost reaches the entire tunnel. In spillway tunnels with walls, the frost zones reach about 100 m from the downstream end. In mildly-inclined diversion tunnels, a frost free zone is located in the middle of the tunnel and snow and ice problems were only observed in the inlet and outlet. Severe aufeis is accumulation is observed in the frost zones. The heat transfer from rock to air, water and ice is calculated and used in a prediction model for the calculation of aufeis build-up together with local field observation data. The water penetration of snow plugs is also calculated, based on the heat balance. It takes 20 to 50 days for water to enter the blocked tunnel. The empirical values are 30 to 60 days, but only 1 day if the temperature of the snow pack is 0{sup o}C. Sensitivity analyses are carried out for temperature variations in rock, snow, water and ice. Systematic field observation shows that it is important for hydropower companies to know about the effects of snow and ice blocking in an area. A risk analysis of dam safety is presented for a real case. Finally, the thesis proposes solutions which can reduce the snow and ice problems. 79 refs., 63 figs., 11 tabs.

  8. Analysis of Blast Wave Propagation Inside Tunnel

    Institute of Scientific and Technical Information of China (English)

    LIU Jingbo; YAN Qiushi; WU Jun

    2008-01-01

    The explosion inside tunnel would generate blast wave which transmits through the longi tudinal tunnel.Because of the close-in effects of the tunnel and the reflection by the confining tunnel structure,blast wave propagation inside tunnel is distinguished from that in air.When the explosion happens inside tunnel,the overpressure peak is higher than that of explosion happening in air.The continuance time of the biast wave also becomes longer.With the help of the numerical simu lation finite element software LS-DYNA.a three-dimensional nonlinear dynamic simulation analysis for an explosion experiment inside tunnel was carried out.LS-DYNA is a fully integrated analysis program specifically designed for nonlinear dynamics and large strain problems.Compared with the experimental results.the simulation results have made the material parameters of numerical simulation model available.By using the model and the same material parameters,many results were adopted by calculating the model under different TNT explosion dynamites.Then the method of dimensional analysis was Used for the Simulation resufts.AS Overpressures of the explosion biast wave are the governing factor in fhe tunnel responses.a formula for the explosion biast wave overpressure at a certain distance from the detonation center point inside the tunnel was de rived by using the dimensional analysis theory.By cornparing the results computed by the fromula with experimental results which were obtained before.the formula was proved to be very applicable at some instance.The research may be helpful to estimate rapidly the effect of internal explosion of tunnel on the structure.

  9. Quantitative risk assessment modeling for nonhomogeneous urban road tunnels.

    Science.gov (United States)

    Meng, Qiang; Qu, Xiaobo; Wang, Xinchang; Yuanita, Vivi; Wong, Siew Chee

    2011-03-01

    Urban road tunnels provide an increasingly cost-effective engineering solution, especially in compact cities like Singapore. For some urban road tunnels, tunnel characteristics such as tunnel configurations, geometries, provisions of tunnel electrical and mechanical systems, traffic volumes, etc. may vary from one section to another. These urban road tunnels that have characterized nonuniform parameters are referred to as nonhomogeneous urban road tunnels. In this study, a novel quantitative risk assessment (QRA) model is proposed for nonhomogeneous urban road tunnels because the existing QRA models for road tunnels are inapplicable to assess the risks in these road tunnels. This model uses a tunnel segmentation principle whereby a nonhomogeneous urban road tunnel is divided into various homogenous sections. Individual risk for road tunnel sections as well as the integrated risk indices for the entire road tunnel is defined. The article then proceeds to develop a new QRA model for each of the homogeneous sections. Compared to the existing QRA models for road tunnels, this section-based model incorporates one additional top event-toxic gases due to traffic congestion-and employs the Poisson regression method to estimate the vehicle accident frequencies of tunnel sections. This article further illustrates an aggregated QRA model for nonhomogeneous urban tunnels by integrating the section-based QRA models. Finally, a case study in Singapore is carried out.

  10. Area and shape changes of the carpal tunnel in response to tunnel pressure.

    Science.gov (United States)

    Li, Zong-Ming; Masters, Tamara L; Mondello, Tracy A

    2011-12-01

    Carpal tunnel mechanics is relevant to our understanding of median nerve compression in the tunnel. The compliant characteristics of the tunnel strongly influence its mechanical environment. We investigated the distensibility of the carpal tunnel in response to tunnel pressure. A custom balloon device was designed to apply controlled pressure. Tunnel cross sections were obtained using magnetic resonance imaging to derive the relationship between carpal tunnel pressure and morphological parameters at the hook of hamate. The results showed that the cross-sectional area (CSA) at the level of the hook of hamate increased, on average, by 9.2% and 14.8% at 100 and 200 mmHg, respectively. The increased CSA was attained by a shape change of the cross section, displaying increased circularity. The increase in CSA was mainly attributable to the increase of area in the carpal arch region formed by the transverse carpal ligament. The narrowing of the carpal arch width was associated with an increase in the carpal arch. We concluded that the carpal tunnel is compliant to accommodate physiological variations of the carpal tunnel pressure, and that the increase in tunnel CSA is achieved by increasing the circularity of the cross section.

  11. Direct Approach to Quantum Tunneling

    Science.gov (United States)

    Andreassen, Anders; Farhi, David; Frost, William; Schwartz, Matthew D.

    2016-12-01

    The decay rates of quasistable states in quantum field theories are usually calculated using instanton methods. Standard derivations of these methods rely in a crucial way upon deformations and analytic continuations of the physical potential and on the saddle-point approximation. While the resulting procedure can be checked against other semiclassical approaches in some one-dimensional cases, it is challenging to trace the role of the relevant physical scales, and any intuitive handle on the precision of the approximations involved is at best obscure. In this Letter, we use a physical definition of the tunneling probability to derive a formula for the decay rate in both quantum mechanics and quantum field theory directly from the Minkowski path integral, without reference to unphysical deformations of the potential. There are numerous benefits to this approach, from nonperturbative applications to precision calculations and aesthetic simplicity.

  12. Tunnel effect wave energy detection

    Science.gov (United States)

    Kaiser, William J. (Inventor); Waltman, Steven B. (Inventor); Kenny, Thomas W. (Inventor)

    1995-01-01

    Methods and apparatus for measuring gravitational and inertial forces, magnetic fields, or wave or radiant energy acting on an object or fluid in space provide an electric tunneling current through a gap between an electrode and that object or fluid in space and vary that gap with any selected one of such forces, magnetic fields, or wave or radiant energy acting on that object or fluid. These methods and apparatus sense a corresponding variation in an electric property of that gap and determine the latter force, magnetic fields, or wave or radiant energy in response to that corresponding variation, and thereby sense or measure such parameters as acceleration, position, particle mass, velocity, magnetic field strength, presence or direction, or wave or radiant energy intensity, presence or direction.

  13. Tunneling magnetoresistance of silicon chains

    Science.gov (United States)

    Matsuura, Yukihito

    2016-05-01

    The tunneling magnetoresistance (TMR) of a silicon chain sandwiched between nickel electrodes was examined by using first-principles density functional theory. The relative orientation of the magnetization in a parallel-alignment (PA) configuration of two nickel electrodes enhanced the current with a bias less than 0.4 V compared with that in an antiparallel-alignment configuration. Consequently, the silicon chain-nickel electrodes yielded good TMR characteristics. In addition, there was polarized spin current in the PA configuration. The spin polarization of sulfur atoms functioning as a linking bridge between the chain and nickel electrode played an important role in the magnetic effects of the electric current. Moreover, the hybridization of the sulfur 3p orbital and σ-conjugated silicon 3p orbital contributed to increasing the total current.

  14. Hawking Radiation and Classical Tunneling

    CERN Document Server

    Tracy, Eugene R

    2015-01-01

    Acoustic waves in fluids undergoing the transition from sub- to supersonic flow satisfy governing equations similar to those for light waves in the immediate vicinity of a black hole event horizon. This acoustic analogy has been used by Unruh and others as a conceptual model for `Hawking radiation.' Here we use variational methods, originally introduced by Brizard for the study of linearized MHD, and ray phase space methods, to analyze linearized acoustics in the presence of background flows. The variational formulation endows the evolution equations with natural Hermitian and symplectic structures that prove useful for later analysis. We derive a $2\\times 2$ normal form governing the wave evolution in the vicinity of the `event horizon.' This shows that the acoustic model can be reduced locally (in ray phase space) to a standard (scalar) tunneling process weakly coupled to a unidirectional non-dispersive wave (the `incoming wave'). Given the normal form, the Hawking `thermal spectrum' can be derived by invok...

  15. Theory of dissociative tunneling ionization

    CERN Document Server

    Svensmark, Jens; Madsen, Lars Bojer

    2016-01-01

    We present a theoretical study of the dissociative tunneling ionization process. Analytic expressions for the nuclear kinetic energy distribution of the ionization rates are derived. A particularly simple expression for the spectrum is found by using the Born-Oppenheimer (BO) approximation in conjunction with the reflection principle. These spectra are compared to exact non-BO ab initio spectra obtained through model calculations with a quantum mechanical treatment of both the electronic and nuclear degrees freedom. In the regime where the BO approximation is applicable imaging of the BO nuclear wave function is demonstrated to be possible through reverse use of the reflection principle, when accounting appropriately for the electronic ionization rate. A qualitative difference between the exact and BO wave functions in the asymptotic region of large electronic distances is shown. Additionally the behavior of the wave function across the turning line is seen to be reminiscent of light refraction. For weak fiel...

  16. Homoepitaxial graphene tunnel barriers for spin transport

    Directory of Open Access Journals (Sweden)

    Adam L. Friedman

    2016-05-01

    Full Text Available Tunnel barriers are key elements for both charge-and spin-based electronics, offering devices with reduced power consumption and new paradigms for information processing. Such devices require mating dissimilar materials, raising issues of heteroepitaxy, interface stability, and electronic states that severely complicate fabrication and compromise performance. Graphene is the perfect tunnel barrier. It is an insulator out-of-plane, possesses a defect-free, linear habit, and is impervious to interdiffusion. Nonetheless, true tunneling between two stacked graphene layers is not possible in environmental conditions usable for electronics applications. However, two stacked graphene layers can be decoupled using chemical functionalization. Here, we demonstrate that hydrogenation or fluorination of graphene can be used to create a tunnel barrier. We demonstrate successful tunneling by measuring non-linear IV curves and a weakly temperature dependent zero-bias resistance. We demonstrate lateral transport of spin currents in non-local spin-valve structures, and determine spin lifetimes with the non-local Hanle effect. We compare the results for hydrogenated and fluorinated tunnel and we discuss the possibility that ferromagnetic moments in the hydrogenated graphene tunnel barrier affect the spin transport of our devices.

  17. Rudolf Hermann, wind tunnels and aerodynamics

    Science.gov (United States)

    Lundquist, Charles A.; Coleman, Anne M.

    2008-04-01

    Rudolf Hermann was born on December 15, 1904 in Leipzig, Germany. He studied at the University of Leipzig and at the Aachen Institute of Technology. His involvement with wind tunnels began in 1934 when Professor Carl Wieselsberger engaged him to work at Aachen on the development of a supersonic wind tunnel. On January 6, 1936, Dr. Wernher von Braun visited Dr. Hermann to arrange for use of the Aachen supersonic wind tunnel for Army problems. On April 1, 1937, Dr. Hermann became Director of the Supersonic Wind Tunnel at the Army installation at Peenemunde. Results from the Aachen and Peenemunde wind tunnels were crucial in achieving aerodynamic stability for the A-4 rocket, later designated as the V-2. Plans to build a Mach 10 'hypersonic' wind tunnel facility at Kochel were accelerated after the Allied air raid on Peenemunde on August 17, 1943. Dr. Hermann was director of the new facility. Ignoring destruction orders from Hitler as WWII approached an end in Europe, Dr. Hermann and his associates hid documents and preserved wind tunnel components that were acquired by the advancing American forces. Dr. Hermann became a consultant to the Air Force at its Wright Field in November 1945. In 1951, he was named professor of Aeronautical Engineering at the University of Minnesota. In 1962, Dr. Hermann became the first Director of the Research Institute at the University of Alabama in Huntsville (UAH), a position he held until he retired in 1970.

  18. Pair Tunneling through Single Molecules

    Science.gov (United States)

    Raikh, Mikhail

    2007-03-01

    Coupling to molecular vibrations induces a polaronic shift, and can lead to a negative charging energy, U. For negative U, the occupation of the ground state of the molecule is even. In this situation, virtual pair transitions between the molecule and the leads can dominate electron transport. At low temperature, T, these transitions give rise to the charge-Kondo effect [1]. We developed the electron transport theory through the negative-U molecule [2] at relatively high T, when the Kondo correlations are suppressed. Two physical ingredients distinguish our theory from the transport through a superconducting grain coupled to the normal leads [3]: (i) in parallel with sequential pair-tunneling processes, single-particle cotunneling processes take place; (ii) the electron pair on the molecule can be created (or annihilated) by two electrons tunneling in from (or out to) opposite leads. We found that, even within the rate-equation description, the behavior of differential conductance through the negative-U molecule as function of the gate voltage is quite peculiar: the height of the peak near the degeneracy point is independent of temperature, while its width is proportional to T. This is in contrast to the ordinary Coulomb-blockade conductance peak, whose integral strength is T-independent. At finite source-drain bias, V>>T, the width of the conductance peak is ˜V, whereas the conventional Coulomb-blockade peak at finite V splits into two sharp peaks at detunings V/2, and -V/2. Possible applications to the gate-controlled current rectification and switching will be discussed. [1] A. Taraphder and P. Coleman, Phys. Rev. Lett. 66, 2814 (1991). [2] J. Koch, M. E. Raikh, and F. von Oppen, Phys. Rev. Lett. 96, 056803 (2006). [3] F. W. J. Hekking, L. I. Glazman, K. A. Matveev, and R. I. Shekhter, Phys. Rev. Lett. 70, 4138 (1993).

  19. Extraskeletal chondroma casuing carpal tunnel syndrome: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ok Hwa; Kim, Yeon Hee [Haeundae Paik Hospital, Inje University College of Medicine, Busan (Korea, Republic of)

    2014-03-15

    Carpal tunnel syndrome caused by extraskeletal chondroma has been scarcely reported in the literature. Authors report a case of carpal tunnel syndrome as a result of an extraskeletal chondroma arising within the carpal tunnel, and describe the radiological and pathological findings of the mass. We also discuss the differential diagnosis of the calcified space, occupying lesions that may occur in carpal tunnel.

  20. Pressure-morphology relationship of a released carpal tunnel.

    Science.gov (United States)

    Kim, Dong Hee; Marquardt, Tamara L; Gabra, Joseph N; Shen, Zhilei Liu; Evans, Peter J; Seitz, William H; Li, Zong-Ming

    2013-04-01

    We investigated morphological changes of a released carpal tunnel in response to variations of carpal tunnel pressure. Pressure within the carpal tunnel is known to be elevated in patients with carpal tunnel syndrome and dependent on wrist posture. Previously, increased carpal tunnel pressure was shown to affect the morphology of the carpal tunnel with an intact transverse carpal ligament (TCL). However, the pressure-morphology relationship of the carpal tunnel after release of the TCL has not been investigated. Carpal tunnel release (CTR) was performed endoscopically on cadaveric hands and the carpal tunnel pressure was dynamically increased from 10 to 120 mmHg. Simultaneously, carpal tunnel cross-sectional images were captured by an ultrasound system, and pressure measurements were recorded by a pressure transducer. Carpal tunnel pressure significantly affected carpal arch area (p 62 mm(2) at 120 mmHg. Carpal arch height, length, and width also significantly changed with carpal tunnel pressure (p carpal tunnel pressure increased, carpal arch height and length increased, but the carpal arch width decreased. Analyses of the pressure-morphology relationship for a released carpal tunnel revealed a nine times greater compliance than that previously reported for a carpal tunnel with an intact TCL. This change of structural properties as a result of transecting the TCL helps explain the reduction of carpal tunnel pressure and relief of symptoms for patients after CTR surgery.

  1. Band-to-Band Tunneling Transistors: Scalability and Circuit Performance

    Science.gov (United States)

    2013-05-01

    To better understand and evaluate tunnel field effect transistors (TFETs), a new TCAD analysis tool with dynamic nonlocal tunneling path...better understand and evaluate tunnel field effect transistors (TFETs), a new TCAD analysis tool with dynamic nonlocal tunneling path determination is...me complete my research with the best of practices. As a perennial procrastinator , my dissertation committee, Prof. Paul Wright, Prof. Sayeef

  2. The Thames Tideway Tunnel (3/3)

    CERN Document Server

    CERN. Geneva

    2012-01-01

    Lecture 3: Insight into a pioneering project at the cutting edge of engineering: the upgrade to London’s failing sewerage system. With a growing population and heavier rainfall, the River Thames is regularly polluted in breach of European Directive requirements. Two new storage and transfer tunnels will run up to 85m deep under the river and will intercept and divert sewer overflows to a treatment facility in east London. The challenges faced by constructing a tunnel project of this size under the river and through London’s historic urban environment will set a new UK record for this type of tunnelling.

  3. HYDRAULIC RESEARCH OF AERATORS ON TUNNEL SPILLWAYS

    Institute of Scientific and Technical Information of China (English)

    RUAN Shi-ping; WU Jian-hua; WU Wei-wei; XI Ru-ze

    2007-01-01

    The selection of the configuration and size of an aerator was of importance for a tunnel spillway under the conditions of high speed flows. Experimental investigations were conducted on the effects of entrained air on the tunnel spillway in the Goupitan Project, based on the criterion of gravity similarity and the condition of aerated flow velocity of over 6 m/s, with physical models. The configurations of the aerators were presented of a larger bottom air concentration, to protect the tunnel spillway from cavitation as well as to see no water fills in the grooves.

  4. Application of Important Factors in Tunnel Projects

    Directory of Open Access Journals (Sweden)

    Siamak Bagherian

    2013-06-01

    Full Text Available The objective of this thesis is to improve the quality of the basis for making decisions about tender prices and budgets for tunnel projects by developing a model for the estimation of construction time and cost. The planning and constructing of extensions to existing road and railway networks is an ongoing mission of transport infrastructure development. For functional, aesthetic or environmental reasons, a large number of these extensions are planned as tunnels. In the planning and procurement phases of tunnel projects, numerous decisions have to be made in relation to the tender price and project budget.

  5. Carpal tunnel syndrome - anatomical and clinical correlations.

    Science.gov (United States)

    Iskra, Tomasz; Mizia, Ewa; Musial, Agata; Matuszyk, Aleksandra; Tomaszewski, Krzysztof A

    2013-01-01

    Carpal tunnel syndrome (CTS) is the most common and widely known of the entrapment neuropathies in which the body's peripheral nerves are compressed. Common symptoms of CTS involve the hand and result from compression of the median nerve within the carpal tunnel. In general, CTS develops when the tissues around the median nerve irritate or compress on the nerve along its course through the carpal tunnel, however often it is very difficult to determine cause of CTS. Proper treatment (conservative or surgical) usually can relieve the symptoms and restore normal use of the wrist and hand.

  6. Tunneling time, exit time and exit momentum in strong field tunnel ionization

    Energy Technology Data Exchange (ETDEWEB)

    Teeny, Nicolas

    2016-10-18

    Tunnel ionization belongs to the fundamental processes of atomic physics. It is still an open question when does the electron tunnel ionize and how long is the duration of tunneling. In this work we solve the time-dependent Schroedinger equation in one and two dimensions and use ab initio quantum calculations in order to answer these questions. Additionally, we determine the exit momentum of the tunnel ionized electron from first principles. We find out results that are different from the assumptions of the commonly employed two-step model, which assumes that the electron ionizes at the instant of electric field maximum with a zero momentum. After determining the quantum final momentum distribution of tunnel ionized electrons we show that the two-step model fails to predict the correct final momentum. Accordingly we suggest how to correct the two-step model. Furthermore, we determine the instant at which tunnel ionization starts, which turns out to be different from the instant usually assumed. From determining the instant at which it is most probable for the electron to enter the tunneling barrier and the instant at which it exits we determine the most probable time spent under the barrier. Moreover, we apply a quantum clock approach in order to determine the duration of tunnel ionization. From the quantum clock we determine an average tunneling time which is different in magnitude and origin with respect to the most probable tunneling time. By defining a probability distribution of tunneling times using virtual detectors we relate both methods and explain the apparent discrepancy. The results found have in general an effect on the interpretation of experiments that measure the spectra of tunnel ionized electrons, and specifically on the calibration of the so called attoclock experiments, because models with imprecise assumptions are usually employed in order to interpret experimental results.

  7. Tunnel Waterproofing with Membranes Waterproofing at Senoko Cabele Tunnel in comparison with International Standards

    Institute of Scientific and Technical Information of China (English)

    Stefan Hotz

    2004-01-01

    Waterproofing of tunnels is and has always been a challenge, worldwide: Changing Geology with hardly predictable water inflow, limited space underground and only very little intervention opportunities once the tunnel is completed. This paper elaborates such challenges and focuses on the waterproofing solutions of mined tunnels with membranes. Different standards and approaches for the waterproofing system. In Singapore, a membrane waterproofing system is used for the shafts and adits at Senoko Cable Tunnel. The paper project specific waterproofing challenges and emphasizes on solution for them.

  8. Tunneling into quantum wires: Regularization of the tunneling Hamiltonian and consistency between free and bosonized fermions

    Science.gov (United States)

    Filippone, Michele; Brouwer, Piet W.

    2016-12-01

    Tunneling between a point contact and a one-dimensional wire is usually described with the help of a tunneling Hamiltonian that contains a δ function in position space. Whereas the leading-order contribution to the tunneling current is independent of the way this δ function is regularized, higher-order corrections with respect to the tunneling amplitude are known to depend on the regularization. Instead of regularizing the δ function in the tunneling Hamiltonian, one may also obtain a finite tunneling current by invoking the ultraviolet cutoffs in a field-theoretic description of the electrons in the one-dimensional conductor, a procedure that is often used in the literature. For the latter case, we show that standard ultraviolet cutoffs lead to different results for the tunneling current in fermionic and bosonized formulations of the theory, when going beyond leading order in the tunneling amplitude. We show how to recover the standard fermionic result using the formalism of functional bosonization and revisit the tunneling current to leading order in the interacting case.

  9. Construction of Foundation for 15-Foot Spin Tunnel

    Science.gov (United States)

    1934-01-01

    Completed foundation for the outer housing for the 15-Foot Spin Tunnel. Charles Zimmerman was given the assignment to design and build a larger spin tunnel that would supplant the 5-foot Vertical Wind Tunnel. Authorization to build the tunnel using funds from the Federal Public Works Administration (PWA) came in June 1933. Construction started in late winter 1934 and the tunnel was operational in April 1935. The initial construction costs were $64,000.

  10. Survey Of Wind Tunnels At Langley Research Center

    Science.gov (United States)

    Bower, Robert E.

    1989-01-01

    Report presented at AIAA 14th Aerodynamic Testing Conference on current capabilities and planned improvements at NASA Langley Research Center's major wind tunnels. Focuses on 14 major tunnels, 8 unique in world, 3 unique in country. Covers Langley Spin Tunnel. Includes new National Transonic Facility (NTF). Also surveys Langley Unitary Plan Wind Tunnel (UPWT). Addresses resurgence of inexpensive simple-to-operate research tunnels. Predicts no shortage of tools for aerospace researcher and engineer in next decade or two.

  11. Survey Of Wind Tunnels At Langley Research Center

    Science.gov (United States)

    Bower, Robert E.

    1989-01-01

    Report presented at AIAA 14th Aerodynamic Testing Conference on current capabilities and planned improvements at NASA Langley Research Center's major wind tunnels. Focuses on 14 major tunnels, 8 unique in world, 3 unique in country. Covers Langley Spin Tunnel. Includes new National Transonic Facility (NTF). Also surveys Langley Unitary Plan Wind Tunnel (UPWT). Addresses resurgence of inexpensive simple-to-operate research tunnels. Predicts no shortage of tools for aerospace researcher and engineer in next decade or two.

  12. Dielectric Sensors Based on Electromagnetic Energy Tunneling

    Directory of Open Access Journals (Sweden)

    Omar Siddiqui

    2015-03-01

    Full Text Available We show that metallic wires embedded in narrow waveguide bends and channels demonstrate resonance behavior at specific frequencies. The electromagnetic energy at these resonances tunnels through the narrow waveguide channels with almost no propagation losses. Under the tunneling behavior, high-intensity electromagnetic fields are produced in the vicinity of the metallic wires. These intense field resonances can be exploited to build highly sensitive dielectric sensors. The sensor operation is explained with the help of full-wave simulations. A practical setup consisting of a 3D waveguide bend is presented to experimentally observe the tunneling phenomenon. The tunneling frequency is predicted by determining the input impedance minima through a variational formula based on the Green function of a probe-excited parallel plate waveguide.

  13. Hi-tech Tunnel Sets World Record

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A sport utility vehicle takes the new direct route from Xi’an, capital city of northwest China’s Shaanxi Province, to Zhashui County through the Zhongnanshan Tunnel, which opened on January 21.With a total investment of nearly 3.2 billion yuan, the four-lane highway is the world’s longest double-tube tunnel, stretching 18.02 km.As a major part of the province’s expressway network, the tunnel connects Xi’an with southwest Shaanxi through the Qinling Mountains, shortening the previous three-hour trip to 40 minutes.The highway tunnel is also planned as part of a national highway linking north China’s Inner Mongolia Autonomous Region and south China’s Guangxi Zhuang Autonomous Region.

  14. Control over Rectification in Supramolecular Tunneling Junctions

    NARCIS (Netherlands)

    Wimbush, K.S.; Wimbush, Kim S.; Reus, William F.; van der Wiel, Wilfred Gerard; Reinhoudt, David; Whitesides, George M.; Nijhuis, C.A.; Velders, Aldrik

    2010-01-01

    In complete control: The magnitude of current rectification in well-defined supramolecular tunneling junctions can be controlled by changing the terminal functionality (red spheres) of dendrimers (gray spheres) immobilized on a supramolecular platform (see picture). Junctions containing biferrocene

  15. Low Speed Wind Tunnel Facility (LSWTF)

    Data.gov (United States)

    Federal Laboratory Consortium — Description: This facility consists of a large-scale, low-speed open-loop induction wind tunnel which has been modified to house a linear turbine cascade. A 125-hp...

  16. Unknotting tunnels in hyperbolic 3-manifolds

    CERN Document Server

    Adams, Colin

    2012-01-01

    An unknotting tunnel in a 3-manifold with boundary is a properly embedded arc, the complement of an open neighborhood of which is a handlebody. A geodesic with endpoints on the cusp boundary of a hyperbolic 3-manifold and perpendicular to the cusp boundary is called a vertical geodesic. Given a vertical geodesic in a hyperbolic 3-manifold M, we find sufficient conditions for it to be an unknotting tunnel. In particular, if the vertical geodesic corresponds to a 4-bracelet, 5-bracelet or 6-bracelet in the universal cover and has short enough length, it must be an unknotting tunnel. Furthermore, we consider a vertical geodesic that satisfies the elder sibling property, which means that in the universal cover, every horoball except the one centered at infinity is connected to a larger horoball by a lift of the vertical geodesic. Such a vertical geodesic with length less than ln(2) is then shown to be an unknotting tunnel.

  17. Proton tunnelling in intermolecular hydrogen bonds

    Energy Technology Data Exchange (ETDEWEB)

    Horsewill, A.J. [Nottingham Univ. (United Kingdom); Johnson, M.R. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France); Trommsdorff, H.P. [Grenoble-1 Univ., 38 (France)

    1997-04-01

    The wavefunctions of particles extend beyond the classically accessible regions of potential energy-surfaces (PES). A manifestation of this partial delocalization is the quantum-mechanical tunneling effect which enables a particle to escape from a metastable potential-well. Tunnelling is most important for the lightest atoms, so that the determination of its contribution to proton transfer, one of the most fundamental chemical reactions, is an important issue. QENS and NMR techniques have been employed to study the motion of protons in the hydrogen bond of benzoic-acid crystals, a system which has emerged as a particularly suitable model since proton transfer occurs in a near symmetric double-well potential. The influence of quantum tunnelling was revealed and investigated in these experiments. This work provides an experimental benchmark for theoretical descriptions of translational proton-tunnelling. (author). 7 refs.

  18. A century of wind tunnels since Eiffel

    Science.gov (United States)

    Chanetz, Bruno

    2017-08-01

    Fly higher, faster, preserve the life of test pilots and passengers, many challenges faced by man since the dawn of the twentieth century, with aviation pioneers. Contemporary of the first aerial exploits, wind tunnels, artificially recreating conditions encountered during the flight, have powerfully contributed to the progress of aeronautics. But the use of wind tunnels is not limited to aviation. The research for better performance, coupled with concern for energy saving, encourages manufacturers of ground vehicles to perform aerodynamic tests. Buildings and bridge structures are also concerned. This article deals principally with the wind tunnels built at ONERA during the last century. Somme wind tunnels outside ONERA, even outside France, are also evocated when their characteristics do not exist at ONERA.

  19. Modeling direct interband tunneling. I. Bulk semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Andrew, E-mail: pandrew@ucla.edu [Department of Electrical Engineering, University of California, Los Angeles, Los Angeles, California 90095 (United States); Chui, Chi On [Department of Electrical Engineering, University of California, Los Angeles, Los Angeles, California 90095 (United States); California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095 (United States)

    2014-08-07

    Interband tunneling is frequently studied using the semiclassical Kane model, despite uncertainty about its validity. Revisiting the physical basis of this formula, we find that it neglects coupling to other bands and underestimates transverse tunneling. As a result, significant errors can arise at low and high fields for small and large gap materials, respectively. We derive a simple multiband tunneling model to correct these defects analytically without arbitrary parameters. Through extensive comparison with band structure and quantum transport calculations for bulk InGaAs, InAs, and InSb, we probe the accuracy of the Kane and multiband formulas and establish the superiority of the latter. We also show that the nonlocal average electric field should be used when applying either of these models to nonuniform potentials. Our findings are important for efficient analysis and simulation of bulk semiconductor devices involving tunneling.

  20. Computer graphic of LHC in the tunnel

    CERN Multimedia

    1996-01-01

    A computer-generated image of the LHC particle accelerator at CERN in the tunnel originally built for the LEP accelerator that was closed in 2000. The cross-section of an LHC superconducting dipole magnet is also seen.

  1. La maquette digitale du tunnel du LEP

    CERN Document Server

    Brouns, G

    2000-01-01

    Pour l'installation du LHC et son équipement périphérique (ligne cryogénique, câbles, tuyauterie, etc.) dans le tunnel du LEP, une maquette digitale CAO doit être faite. Après un rappel de la définition théorique du tunnel du LEP, cette LHC project Note décrit comment sont utilisées et intégrées d'anciennes et de nouvelles mesures du tunnel pour arriver à un ensemble de données qui permettent de construire la maquette digitale (CAO) du tunnel du LHC. Ensuite, les résultats sont comparés à leur valeur théorique d'une part, et aux anciennes valeurs disponibles d'autre part.

  2. Many-electron tunneling in atoms

    CERN Document Server

    Zon, B A

    1999-01-01

    A theoretical derivation is given for the formula describing N-electron ionization of atom by a dc field and laser radiation in tunneling regime. Numerical examples are presented for noble gases atoms.

  3. Teelt van vruchtgewassen in lage tunnels

    NARCIS (Netherlands)

    Wijk, van C.A.P.; Geven, C.G.M.

    1994-01-01

    Een aantal warmteminnende vruchtgewassen zijn beproefd in lage tunnels en vergeleken met onbedekte teelt en met kasteelt. Het betrof aubergine, paprika, peper en diverse typen meloen. Daar is courgette als vergelijkend gewas aan toegevoegd

  4. Decoherence and tunneling of an interacting gas

    Science.gov (United States)

    Anglin, James; Rico-Perez, Luis; Wohlfarth, Daniel

    2015-05-01

    In quasi-steady escape of a confined interacting gas by quantum tunneling, collisional decoherence can reduce the escape rate through a many-body version of the Caldeira-Leggett effect. This explains why classical fluids fail to tunnel, even though they are composed of particles small enough to be quantum mechanical. We compute this effect in the Maxwell-Boltzmann regime by deriving a quantum generalization of the Boltzmann equation. We show that decoherence effectively makes tunneling of an interacting gas into an irreversible process: a uniquely quantum mechanical form of throttling. The rate of entropy production in tunneling is related in the semi-classical limit to the imaginary part of the single-particle action.

  5. A small cable tunnel inspection robot design

    Science.gov (United States)

    Zhou, Xiaolong; Guo, Xiaoxue; Huang, Jiangcheng; Xiao, Jie

    2017-04-01

    Modern city mainly rely on internal electricity cable tunnel, this can reduce the influence of high voltage over-head lines of urban city appearance and function. In order to reduce the dangers of cable tunnel artificial inspection and high labor intensity, we design a small caterpillar chassis in combination with two degrees of freedom robot with two degrees of freedom camera pan and tilt, used in the cable tunnel inspection work. Caterpillar chassis adopts simple return roller, damping structure. Mechanical arm with three parallel shafts, finish the up and down and rotated action. Two degrees of freedom camera pan and tilt are used to monitor cable tunnel with 360 °no dead angle. It looks simple, practical and efficient.

  6. 7 x 10 Foot Wind Tunnel

    Data.gov (United States)

    Federal Laboratory Consortium — This wind tunnel is used for basic and applied research in aeromechanics on advanced and unique technology rotorcraft. It supports research on advanced concepts and...

  7. Dynamical quenching of tunneling in molecular magnets

    Energy Technology Data Exchange (ETDEWEB)

    José Santander, María, E-mail: maria.jose.noemi@gmail.com [Recursos Educativos Quántica, Santiago (Chile); Departamento de Física, Universidad de Santiago de Chile and CEDENNA, Avda. Ecuador 3493, Santiago (Chile); Nunez, Alvaro S., E-mail: alnunez@dfi.uchile.cl [Departamento de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Casilla 487-3, Santiago (Chile); Roldán-Molina, A. [Instituto de Física, Pontificia Universidad Católica de Valparaíso, Avenida Universidad 330, Curauma, Valparaíso (Chile); Troncoso, Roberto E., E-mail: r.troncoso.c@gmail.com [Centro para el Desarrollo de la Nanociencia y la Nanotecnología, CEDENNA, Avda. Ecuador 3493, Santiago 9170124 (Chile); Departamento de Física, Universidad Técnica Federico Santa María, Avenida España 1680, Valparaíso (Chile)

    2015-12-15

    It is shown that a single molecular magnet placed in a rapidly oscillating magnetic field displays the phenomenon of quenching of tunneling processes. The results open a way to manipulate the quantum states of molecular magnets by means of radiation in the terahertz range. Our analysis separates the time evolution into slow and fast components thereby obtaining an effective theory for the slow dynamics. This effective theory presents quenching of the tunnel effect, in particular, stands out its difference with the so-called coherent destruction of tunneling. We support our prediction with numerical evidence based on an exact solution of Schrödinger's equation. - Highlights: • Single molecular magnets under rapidly oscillating magnetic fields is studied. • It is shown that this system displays the quenching of tunneling processes. • Our findings provide a control of quantum molecular magnets via terahertz radiation.

  8. LEP sees the end of the tunnel

    CERN Document Server

    2002-01-01

    After 14 months, which have seen the removal of 30,000 tonnes of material from the tunnel, the LEP dismantling operation has now been completed. LHC installation, which will be subject to new safety rules, can go ahead.

  9. Tertiary interactions within the ribosomal exit tunnel.

    Science.gov (United States)

    Kosolapov, Andrey; Deutsch, Carol

    2009-04-01

    Although tertiary folding of whole protein domains is prohibited by the cramped dimensions of the ribosomal tunnel, dynamic tertiary interactions may permit folding of small elementary units within the tunnel. To probe this possibility, we used a beta-hairpin and an alpha-helical hairpin from the cytosolic N terminus of a voltage-gated potassium channel and determined a probability of folding for each at defined locations inside and outside the tunnel. Minimalist tertiary structures can form near the exit port of the tunnel, a region that provides an entropic window for initial exploration of local peptide conformations. Tertiary subdomains of the nascent peptide fold sequentially, but not independently, during translation. These studies offer an approach for diagnosing the molecular basis for folding defects that lead to protein malfunction and provide insight into the role of the ribosome during early potassium channel biogenesis.

  10. Observing Quantum Tunneling in Perturbation Series

    CERN Document Server

    Suzuki, H; Suzuki, Hiroshi; Yasuta, Hirofumi

    1996-01-01

    We apply Borel resummation method to the conventional perturbation series of ground state energy in a metastable potential, $V(x)=x^2/2-gx^4/4$. We observe numerically that the discontinuity of Borel transform reproduces the imaginary part of energy eigenvalue, i.e., total decay width due to the quantum tunneling. The agreement with the exact numerical value is remarkable in the whole tunneling regime $0

  11. Low Power Band to Band Tunnel Transistors

    Science.gov (United States)

    2010-12-15

    the E-field and tunneling at the source- pocket junction you form a parasitic NPN + transistor and the injection mechanism of carriers into the...hypothesis that the 1000 ° C, 5s anneal split lead to a very wide pocket and the accidental formation of a NPN + transistor , while the 1000 ° C, 1s anneal...Low Power Band to Band Tunnel Transistors Anupama Bowonder Electrical Engineering and Computer Sciences University of California at Berkeley

  12. Geology of Pletovarje motorway tunnel (Slovenia

    Directory of Open Access Journals (Sweden)

    Magda Čarman

    2009-06-01

    Full Text Available Styrian motorway crosses the Pletovarje ridge through the tunnel having the same name. It intersects the mosteastern extension of the Southern Karavanke tectonic unit. Considering geological conditions, the tunnel couldbe divided into three sections: the inner Donat / Dona~ka fault zone composed of tectonic lenses of differentlithostratigraphic units (of paleozoic, triassic and tertiary age, massive dolomite (lower triassic and Smrekovecseries of oligocene age. Main faults have east – west direction and are subvertical.

  13. Numerical modeling of tunneling-induced seismicity

    Science.gov (United States)

    Rinaldi, Antonio Pio; Urpi, Luca

    2017-04-01

    Removal of rock mass in mining environment has been associated since long-time with seismic event of magnitude 3 and above, with the potential to cause damage to the infrastructures or even loss of human life. Although with similarities with mining, relatively unknown up to now are seismic events induced by tunneling. However with modern mechanized tunneling techniques, making possible to digging deeper and longer underground infrastructure, the risk is not negligible. As an example, the excavation of the 57km long Gotthard Base Tunnel has been associated more than hundred seismic events, with the largest one having magnitude of ML 2.4, damaging the tunnel infrastructures. For future scenario of deep geological storage of nuclear waste, tunneling will constitute the primary activity during site construction. Hence, it will be crucial to understand the risk associated with the underground construction operation that can reactivate seismogenic features nearby the future location of emplacement tunnels. Here we present numerical simulation aimed at understanding the potential for inducing seismicity during tunnel construction. The stress changes and their evolution during the excavation are evaluated with a finite element solver (FLAC3d). A strain-softening friction model is then used to simulate the occurrence of a sudden slip on a fault zone (if critical conditions for reactivation are reached). We also present a sensitivity analysis of the potential for inducing different seismic events by different tunnel sizes at varying distance from a nearby failure plane, with the final purpose of evaluating safety of a potential nuclear repository site on the short- and long-term.

  14. Aeroelastic instability stoppers for wind tunnel models

    Science.gov (United States)

    Doggett, R. V., Jr.; Ricketts, R. H. (Inventor)

    1981-01-01

    A mechanism for constraining models or sections thereof, was wind tunnel tested, deployed at the onset of aeroelastic instability, to forestall destructive vibrations in the model is described. The mechanism includes a pair of arms pivoted to the tunnel wall and straddling the model. Rollers on the ends of the arms contact the model, and are pulled together against the model by a spring stretched between the arms. An actuator mechanism swings the arms into place and back as desired.

  15. Radio-frequency scanning tunnelling microscopy.

    Science.gov (United States)

    Kemiktarak, U; Ndukum, T; Schwab, K C; Ekinci, K L

    2007-11-01

    The scanning tunnelling microscope (STM) relies on localized electron tunnelling between a sharp probe tip and a conducting sample to attain atomic-scale spatial resolution. In the 25-year period since its invention, the STM has helped uncover a wealth of phenomena in diverse physical systems--ranging from semiconductors to superconductors to atomic and molecular nanosystems. A severe limitation in scanning tunnelling microscopy is the low temporal resolution, originating from the diminished high-frequency response of the tunnel current readout circuitry. Here we overcome this limitation by measuring the reflection from a resonant inductor-capacitor circuit in which the tunnel junction is embedded, and demonstrate electronic bandwidths as high as 10 MHz. This approximately 100-fold bandwidth improvement on the state of the art translates into fast surface topography as well as delicate measurements in mesoscopic electronics and mechanics. Broadband noise measurements across the tunnel junction using this radio-frequency STM have allowed us to perform thermometry at the nanometre scale. Furthermore, we have detected high-frequency mechanical motion with a sensitivity approaching approximately 15 fm Hz(-1/2). This sensitivity is on par with the highest available from nanoscale optical and electrical displacement detection techniques, and the radio-frequency STM is expected to be capable of quantum-limited position measurements.

  16. Radiometric dating of the Siloam Tunnel, Jerusalem.

    Science.gov (United States)

    Frumkin, Amos; Shimron, Aryeh; Rosenbaum, Jeff

    2003-09-11

    The historical credibility of texts from the Bible is often debated when compared with Iron Age archaeological finds (refs. 1, 2 and references therein). Modern scientific methods may, in principle, be used to independently date structures that seem to be mentioned in the biblical text, to evaluate its historical authenticity. In reality, however, this approach is extremely difficult because of poor archaeological preservation, uncertainty in identification, scarcity of datable materials, and restricted scientific access into well-identified worship sites. Because of these problems, no well-identified Biblical structure has been radiometrically dated until now. Here we report radiocarbon and U-Th dating of the Siloam Tunnel, proving its Iron Age II date; we conclude that the Biblical text presents an accurate historic record of the Siloam Tunnel's construction. Being one of the longest ancient water tunnels lacking intermediate shafts, dating the Siloam Tunnel is a key to determining where and when this technological breakthrough took place. Siloam Tunnel dating also refutes a claim that the tunnel was constructed in the second century bc.

  17. Some Caves in tunnels in Dinaric karst of Croatia

    Science.gov (United States)

    Garasic, Mladen; Garasic, Davor

    2016-04-01

    In the last 50 years during the construction of almost all the tunnels in the Croatian Dinaric Karst thousands of caves have been encountered that represented the major problems during the construction works. Geological features (fissures, folding, faults, etc.) are described in this contribution, together with the hydrogeological conditions (rapid changes in groundwater levels). Special engineering geological exploration and survey of each cave, together with the stabilization of the tunnel ceiling, and groundwater protection actions according to basic engineering geological parameters are also presented. In karst tunneling in Croatia over 150 caves longer than 500 m have been investigated. Several caves are over 300 m deep (St. Ilija tunnel in Biokovo Mt), and 10 are longer than 1000 m (St.Rok tunnel, HE Senj and HE Velebit tunnels in Velebit Mt, Ucka tunnel in Ucka Mt, Mala kapela tunnel in Kapela Mt, caverns in HE Plat tunnel etc). Different solutions were chosen to cross the caves depending on the size and purpose of the tunnels (road, rail, pedestrian tunnel, or hydrotechnical tunnels). This is presentations of interesting examples of ceiling stabilization in big cave chambers, construction of bridges inside tunnels, deviations of tunnels, filling caves, grouting, etc. A complex type of karstification has been found in the cavern at the contact between the Palaeozoic clastic impervious formations and the Mesozoic complex of dolomitic limestones in the Vrata Tunnel and at the contact with flysch in the Učka Tunnel. However, karstification advancing in all directions at a similar rate is quite rare. The need to have the roadway and/or tunnel above water from a spring is the biggest possible engineering-geological, hydrogeological and civil engineering challenge. Significant examples are those above the Jadro spring (Mravinci tunnel) in flysch materials or above the Zvir spring in Rijeka (Katarina tunnel), and in fractured Mesozoic carbonates. Today in Croatian

  18. Study on calculation of rock pressure for ultra-shallow tunnel in poor surrounding rock and its tunneling procedure

    Institute of Scientific and Technical Information of China (English)

    Xiaojun Zhou; Jinghe Wang; Bentao Lin

    2014-01-01

    A computational method of rock pressure applied to an ultra-shallow tunnel is presented by key block theory, and its mathematical formula is proposed according to a mechanical tunnel model with super-shallow depth. Theoretical analysis shows that the tunnel is subject to asymmetric rock pressure due to oblique topography. The rock pressure applied to the tunnel crown and sidewall is closely related to the surrounding rock bulk density, tunnel size, depth and angle of oblique ground slope. The rock pressure applied to the tunnel crown is much greater than that to the sidewalls, and the load applied to the left side-wall is also greater than that to the right sidewall. Mean-while, the safety of the lining for an ultra-shallow tunnel in strata with inclined surface is affected by rock pressure and tunnel support parameters. Steel pipe grouting from ground surface is used to consolidate the unfavorable surrounding rock before tunnel excavation, and the reinforcing scope is proposed according to the analysis of the asymmetric load induced by tunnel excavation in weak rock with inclined ground surface. The tunneling procedure of bench cut method with pipe roof protection is still discussed and carried out in this paper according to the special geological condition. The method and tunneling procedure have been successfully utilized to design and drive a real expressway tunnel. The practice in building the super-shallow tunnel has proved the feasibility of the calculation method and tunneling procedure presented in this paper.

  19. Tunneling and Transport in Nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Goldman, Allen M. [Univ. of Minnesota, Minneapolis, MN (United States)

    2016-08-16

    The goal of this program was to study new physical phenomena that might be relevant to the performance of conductive devices and circuits of the smallest realizable feature sizes possible using physical rather than biological techniques. Although the initial scientific work supported involved the use of scanning tunneling microscopy and spectroscopy to ascertain the statistics of the energy level distribution of randomly sized and randomly shaped quantum dots, or nano-crystals, the main focus was on the investigation of selected properties, including superconductivity, of conducting and superconducting nanowires prepared using electron-beam-lithography. We discovered a magnetic-field-restoration of superconductivity in out-of-equilibrium nanowires driven resistive by current. This phenomenon was explained by the existence of a state in which dissipation coexisted with nonvanishing superconducting order. We also produced ultra-small superconducting loops to study a predicted anomalous fluxoid quantization, but instead, found a magnetic-field-dependent, high-resistance state, rather than superconductivity. Finally, we developed a simple and controllable nanowire in an induced charged layer near the surface of a masked single-crystal insulator, SrTiO3. The layer was induced using an electric double layer transistor employing an ionic liquid (IL). The transport properties of the induced nanowire resembled those of collective electronic transport through an array of quantum dots.

  20. Organic tunnel field effect transistors

    KAUST Repository

    Tietze, Max Lutz

    2017-06-29

    Various examples are provided for organic tunnel field effect transistors (OTFET), and methods thereof. In one example, an OTFET includes a first intrinsic layer (i-layer) of organic semiconductor material disposed over a gate insulating layer; source (or drain) contact stacks disposed on portions of the first i-layer; a second i-layer of organic semiconductor material disposed on the first i-layer surrounding the source (or drain) contact stacks; an n-doped organic semiconductor layer disposed on the second i-layer; and a drain (or source) contact layer disposed on the n-doped organic semiconductor layer. The source (or drain) contact stacks can include a p-doped injection layer, a source (or drain) contact layer, and a contact insulating layer. In another example, a method includes disposing a first i-layer over a gate insulating layer; forming source or drain contact stacks; and disposing a second i-layer, an n-doped organic semiconductor layer, and a drain or source contact.

  1. Tunneling and Transport in Nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Goldman, Allen M. [Univ. of Minnesota, Minneapolis, MN (United States)

    2016-08-16

    The goal of this program was to study new physical phenomena that might be relevant to the performance of conductive devices and circuits of the smallest realizable feature sizes possible using physical rather than biological techniques. Although the initial scientific work supported involved the use of scanning tunneling microscopy and spectroscopy to ascertain the statistics of the energy level distribution of randomly sized and randomly shaped quantum dots, or nano-crystals, the main focus was on the investigation of selected properties, including superconductivity, of conducting and superconducting nanowires prepared using electron-beam-lithography. We discovered a magnetic-field-restoration of superconductivity in out-of-equilibrium nanowires driven resistive by current. This phenomenon was explained by the existence of a state in which dissipation coexisted with nonvanishing superconducting order. We also produced ultra-small superconducting loops to study a predicted anomalous fluxoid quantization, but instead, found a magnetic-field-dependent, high-resistance state, rather than superconductivity. Finally, we developed a simple and controllable nanowire in an induced charged layer near the surface of a masked single-crystal insulator, SrTiO3. The layer was induced using an electric double layer transistor employing an ionic liquid (IL). The transport properties of the induced nanowire resembled those of collective electronic transport through an array of quantum dots.

  2. Le LHC, un tunnel cosmique

    CERN Document Server

    CERN. Geneva

    2009-01-01

    Et si la lumière au bout du tunnel du LHC était cosmique ? En d’autres termes, qu’est-ce que le LHC peut nous apporter dans la connaissance de l’Univers ? Car la montée en énergie des accélérateurs de particules nous permet de mieux appréhender l’univers primordial, chaud et dense. Mais dans quel sens dit-on que le LHC reproduit des conditions proches du Big bang ? Quelles informations nous apporte-t-il sur le contenu de l’Univers ? La matière noire est-elle détectable au LHC ? L’énergie noire ? Pourquoi l’antimatière accumulée au CERN est-elle si rare dans l’Univers ? Et si le CERN a bâti sa réputation sur l’exploration des forces faibles et fortes qui opèrent au sein des atomes et de leurs noyaux, est-ce que le LHC peut nous apporter des informations sur la force gravitationnelle qui gouverne l’évolution cosmique ? Depuis une trentaine d’années, notre compréhension de l’univers dans ses plus grandes dimensions et l’appréhension de son comportement aux plus peti...

  3. Validation of a Compact Isokinetic Total Water Content Probe for Wind Tunnel Characterization at NASA Glenn Icing Research Tunnel and at NRC Ice Crystal Tunnel

    Science.gov (United States)

    Davison, Craig R.; Landreville, Charles; Ratvasky, Thomas P.

    2017-01-01

    A new compact isokinetic probe to measure total water content in a wind tunnel environment has been developed. The probe has been previously tested under altitude conditions. This paper presents a comprehensive validation of the probe under a range of liquid water conditions at sea level in the NASA Glenn Icing Research Tunnel and with ice crystals at sea level at the NRC wind tunnel. The compact isokinetic probe is compared to tunnel calibrations and other probes.

  4. European Tunnelling Review Quality, Environment and Safety Focus

    Institute of Scientific and Technical Information of China (English)

    Bill Weburn

    2004-01-01

    This paper provides an overview of tunnelling projects with some of the themes covered by the Chengdu Tunnelling Conference.(a) Environmental issues and tunnels under high groundwater pressure (Hallandsis Rail Tunnel, Sweden)(b) Fire -fighting and tunnel safety on long highway tunnels (Socatop Tunnel, West Paris)(c) Mechanised tunnelling below the world's largest airport (Heathrow T5) of a quality that avoids disruption to its operation.Each of these overviews show an enhanced performance in regard to project specific events or objectives. Particularly in tunnelling, project owners expect more than just a facility delivered on time for their money: they expect an all round performance respecting deadlines, budget, environmental protection, safety, quality and community harmony. Funding agencies do not always have the same agenda as project owners, acknowledging peripheral selection criteria but often demanding that the lowest bidder be awarded work. All round performance requires all round project selection criteria.

  5. Development of the tunneling junction simulation environment for scanning tunneling microscope evaluation

    Science.gov (United States)

    Gajewski, Krzysztof; Piasecki, Tomasz; Kopiec, Daniel; Gotszalk, Teodor

    2017-03-01

    Proper configuration of scanning tunneling microscope electronics plays an important role in the atomic scale resolution surface imaging. Device evaluation in the tunneling contact between scanning tip and sample may be prone to the surface quality or mechanical disturbances. Thus the use of tunneling junction simulator makes electronics testing more reliable and increases its repeatability. Here, we present the theoretical background enabling the proper selection of electronic components circuitry used as a tunneling junction simulator. We also show how to simulate mechanics related to the piezoelectric scanner, which is applied in real experiments. Practical use of the proposed simulator and its application in metrological characterization of the developed scanning tunneling microscope is also shown.

  6. Determination of the effectiveness of concentrating mine-tunneling operations

    Energy Technology Data Exchange (ETDEWEB)

    Domanov, P.I.

    1979-02-01

    Experimental operations were conducted in 163 tunneling faces equipped with loading machines and mounted drilling machines and in 110 faces equipped with the pneumatic drilling machines 1PNB-2E in order to determine the optimal specific population of tunnellers in a working face. Following computerized processing of the obtained data, mathematical formulas were derived to compute the optimal rate of tunneling drifts with respect to productivity. Relationships were given for the productivity of drift miners and the rate of tunneling drifts, and between the complete cost of tunneling a drift and the velocity of tunneling. 3 figures.

  7. Performance Analysis of VOIP over GRE Tunnel

    Directory of Open Access Journals (Sweden)

    Aria. Asadi Eskandar

    2015-11-01

    Full Text Available Voice over IP (VoIP is commonly known as phone service over the Internet. Any service using public IP network requires certain extent of security. Demand for security in VOIP technology is increasing. VPN is one of the commonly used methods to secure VOIP traffic. In this paper we simulated behavior of a VOIP communication while running over a GRE VPN Tunnel using OPNET Modeler 17.5. During the simulation, such performance parameters as: choice of voice signaling protocol, voice Codec, parameters arising from network QoS (in this study, homogenous vs. heterogeneous network environment and type of VPN tunneling protocol, were examined. We evaluated performance of VOIP communications in homogenous and heterogeneous network environments, configured based on two different signaling protocols, namely H.323 and SIP. Also, G.711 and G.723 were configured and tested as the choice for voice Codecs. GRE was implemented as the tunneling protocol. Result analysis of this study indicated that GRE Tunnel didn't show a significant increase in such call quality of service (QoS performance factors as: end-to-end delay, call setup time, or a decrease in call MOS value. Even though in a non-ideal (heterogeneous network environment, call quality of service (QoS performance factors shoed poor results; however, there was no significant evidence to suggest that GRE Tunnel is the root cause for such poor results.

  8. Tunnel Field-Effect Transistor with Epitaxially Grown Tunnel Junction Fabricated by Source/Drain-First and Tunnel-Junction-Last Processes

    Science.gov (United States)

    Morita, Yukinori; Mori, Takahiro; Migita, Shinji; Mizubayashi, Wataru; Tanabe, Akihito; Fukuda, Koichi; Masahara, Meishoku; Ota, Hiroyuki

    2013-04-01

    We fabricate p- and n-channel Si tunnel field-effect transistors (TFETs) with an epitaxially grown tunnel junction. In a novel source/drain-first and tunnel-junction-last fabrication process, a thin epitaxial undoped Si channel (epichannel) is deposited on a preferentially fabricated p- or n-type source area. The epichannel sandwiched by a gate insulator and a highly doped source well acts as a parallel-plate tunnel capacitor, which effectively multiplies drain current with an enlarged tunnel area. On the basis of its simple structure and easy fabrication, symmetric n- and p-transistor and complementary metal oxide semiconductor inverter operations were successfully demonstrated.

  9. Drillhole gamma-ray spectrum logging in drillholes OL-KR11, OL-KR44, OL-KR44B, OL-KR45B, OL-KR46, OL-KR47, OL-KR47B, OL-KR48 and ground survey at Olkiluoto in Eurajoki, 2007 and 2008

    Energy Technology Data Exchange (ETDEWEB)

    Julkunen, A.; Kallio, L.; Kuusisto, M. (Astrock Oy, Sodankylae (Finland))

    2009-09-15

    The aim of the detailed drillhole surveys is to increase the knowledge of the bedrock on the study area and to supplement the investigations made earlier. As a part of the detailed investigations Astrock Oy carried out drillhole spectrometer logging in drillholes OL-KR11, OL-KR44, OL-KR44B, OL-KR45B, OL-KR46, OL-KR47, OL-KR47B, OL-KR48 and ground survey at Olkiluoto site in Eurajoki during 2007 and 2008. This report describes the logging, data processing and the results. For the first time the results contains moving standard deviation calculations of Th/K ratio, because the variability of Th/K ratio is a reasonably good indicator of alteration zones. This report includes also moving standard deviation calculations of Th/K ratio from earlier measured and reported drillholes OL-KR40-43 and OL-KR40B-43B. (orig.)

  10. Overview of traffic safety aspects and design in road tunnels

    Directory of Open Access Journals (Sweden)

    Shy Bassan

    2016-07-01

    Drivers in road tunnels generally reduce their speed and increase their lateral position from the right tunnel wall while driving. In shorter tunnels, with reduced driving speed, driver vigilance may be more robust without being hindered by dull driving, which is more common in longer tunnels. Still, in spite of driver alertness, crash rates in tunnels occur due to the tunnel's unusual driving environment. Crash rates are lower in the tunnel inner zone due to driver alertness, especially after passing the transition zone and acclimating to the tunnel environment. The number of crashes, however, is higher along zone 4 (tunnel inner zone, which is the principal zone, as it covers longer driving distance. According to most studies, short tunnels were found to exhibit higher crash rates than long tunnels because the entrance zones incorporate higher crash rates, compared with the midzones; nonetheless, longer unidirectional (freeway and multilane tunnels with higher design speed, entail lower driver alertness and diminished concentration due to relatively monotonous driving in spite of a tunnel's closed environment.

  11. Particle and chemical control using tunnel flow

    Energy Technology Data Exchange (ETDEWEB)

    Chilese, Frank; Delgado, Gildardo R.; Wack, Daniel; Torczynski, John R.

    2017-09-12

    An apparatus for contaminant control, having: a first optical assembly including: a first light homogenizer tunnel with: a first end connected to an extreme ultra-violet light source, a second end in communication with a destination chamber, a first enclosed space, and, a first gas input arranged to introduce a first gas such that the first gas flows in a first direction toward the first end and in a second direction toward the second end. The apparatus alternately having: a second optical assembly including: a second light homogenizer tunnel with: a third end connected to an extreme ultra-violet light source, a fourth end in communication with a destination chamber, a second enclosed space, a diffusion barrier tube including: a fifth end facing the fourth end and a sixth end in communication with a destination chamber, and a second gas input between the second light homogenizer tunnel and the diffusion tube.

  12. Quantum tunneling from paths in complex time

    CERN Document Server

    Bramberger, Sebastian F; Lehners, Jean-Luc

    2016-01-01

    We study quantum mechanical tunneling using complex solutions of the classical field equations. Simple visualization techniques allow us to unify and generalize previous treatments, and straightforwardly show the connection to the standard approach using Euclidean instanton solutions. We demonstrate that the negative modes of solutions along various contours in the complex time plane reveal which paths contribute to tunneling and which do not, and we provide a criterion for identifying the negative modes. Central to our approach is the solution of the background and perturbation equations not only along a single path, but over an extended region of the complex time plane. Our approach allows for a fully continuous and coherent treatment of classical evolution interspersed by quantum tunneling events, and is applicable in situations where singularities are present and also where Euclidean solutions might not exist.

  13. Multidimensional Quantum Tunneling in the Schwinger Effect

    CERN Document Server

    Dumlu, Cesim K

    2015-01-01

    We study the Schwinger effect, in which the external field having a spatio-temporal profile creates electron-positron pairs via multidimensional quantum tunneling. Our treatment is based on Gutzwiller's trace formula for the QED effective action, whose imaginary part is represented by a sum over complex wordlines. The worldlines are multi-periodic, and the periods of motion collectively depend on the strength of spatial and temporal inhomogeneity. We argue that Hamilton's characteristic function that leads to the correct tunneling amplitude must explicitly depend on both periods, and is represented by an average over the internal cycles of motion. We use this averaging method to calculate the pair production rate in an exponentially damped sinusoidal field, where we find that the initial conditions for each family of periodic trajectories lie on a curve in the momentum plane. The ratio of the periods, which may also be referred as the topological index, stays uniform on each curve. Calculation of tunneling am...

  14. Phonon tunneling through a double barrier system

    Energy Technology Data Exchange (ETDEWEB)

    Villegas, Diosdado [Departamento de Física, Universidad Central “Marta Abreu” de Las Villas, CP 54830, Santa Clara, Villa Clara (Cuba); Instituto de Física, Universidad Autónoma de Puebla, 18 Sur y San Claudio, Edif. 110A, Ciudad Universitaria, 72570 Puebla (Mexico); León-Pérez, Fernando de [Centro Universitario de la Defensa de Zaragoza, Ctra. de Huesca s/n, E-50090 Zaragoza (Spain); Pérez-Álvarez, R. [Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, CP 62209 Cuernavaca (Mexico); Arriaga, J., E-mail: arriaga@ifuap.buap.mx [Instituto de Física, Universidad Autónoma de Puebla, 18 Sur y San Claudio, Edif. 110A, Ciudad Universitaria, 72570 Puebla (Mexico)

    2015-04-15

    The tunneling of optical and acoustic phonons at normal incidence on a double-barrier is studied in this paper. Transmission coefficients and resonance conditions are derived theoretically under the assumption that the long-wavelength approximation is valid. It is shown that the behavior of the transmission coefficients for the symmetric double barrier has a Lorentzian form close to resonant frequencies and that Breit–Wigner's formula have a general validity in one-dimensional phonon tunneling. Authors also study the so-called generalized Hartman effect in the tunneling of long-wavelength phonons and show that this effect is a numerical artifact resulting from taking the opaque limit before exploring the variation with a finite barrier width. This study could be useful for the design of acoustic devices.

  15. Isotope effects of hydrogen and atom tunnelling

    Science.gov (United States)

    Buchachenko, A. L.; Pliss, E. M.

    2016-06-01

    The abnormally high mass-dependent isotope effects in liquid-phase hydrogen (deuterium) atom transfer reactions, which are customarily regarded as quantum effects, are actually the products of two classical effects, namely, kinetic and thermodynamic ones. The former is determined by the rate constants for atom transfer and the latter is caused by nonbonded (or noncovalent) isotope effects in the solvation of protiated and deuterated reacting molecules. This product can mimic the large isotope effects that are usually attributed to tunnelling. In enzymatic reactions, tunnelling is of particular interest; its existence characterizes an enzyme as a rigid molecular machine in which the residence time of reactants on the reaction coordinate exceeds the waiting time for the tunnelling event. The magnitude of isotope effect becomes a characteristic parameter of the internal dynamics of the enzyme catalytic site. The bibliography includes 61 references.

  16. Electronic thermometry in tunable tunnel junction

    Energy Technology Data Exchange (ETDEWEB)

    Maksymovych, Petro

    2016-03-15

    A tunable tunnel junction thermometry circuit includes a variable width tunnel junction between a test object and a probe. The junction width is varied and a change in thermovoltage across the junction with respect to the change in distance across the junction is determined. Also, a change in biased current with respect to a change in distance across the junction is determined. A temperature gradient across the junction is determined based on a mathematical relationship between the temperature gradient, the change in thermovoltage with respect to distance and the change in biased current with respect to distance. Thermovoltage may be measured by nullifying a thermoelectric tunneling current with an applied voltage supply level. A piezoelectric actuator may modulate the probe, and thus the junction width, to vary thermovoltage and biased current across the junction. Lock-in amplifiers measure the derivatives of the thermovoltage and biased current modulated by varying junction width.

  17. Vibration Compensation for Scanning Tunneling Microscope

    Institute of Scientific and Technical Information of China (English)

    LI Meng-chao; FU Xing; WEI Xiao-lei; HU Xiao-tang

    2003-01-01

    The influence of vibration is already one of main obstacles for improving the nano measuring accuracy.The techniques of anti-vibration,vibration isolation and vibration compensation become an important branch in nano measuring field.Starting with the research of sensitivity to vibration of scanning tunneling microscope(STM),the theory,techniques and realization methods of nano vibration sensor based on tunnel effect are initially investigated,followed by developing the experimental devices.The experiments of the vibration detection and vibration compensation are carried out.The experimental results show that vibration sensor based on tunnel effect is characterized by high sensitivity,good frequency characteristic and the same vibratory response characteristic consistent with STM.

  18. Scanning Tunneling Spectroscope Use in Electrocatalysis Testing

    Science.gov (United States)

    Knutsen, Turid

    2010-01-01

    The relationship between the electrocatalytic properties of an electrode and its ability to transfer electrons between the electrode and a metallic tip in a scanning tunneling microscope (STM) is investigated. The alkaline oxygen evolution reaction (OER) was used as a test reaction with four different metallic glasses, Ni78Si8B14, Ni70Mo20Si5B5, Ni58Co20Si10B12, and Ni25Co50Si15B10, as electrodes. The electrocatalytic properties of the electrodes were determined. The electrode surfaces were then investigated with an STM. A clear relationship between the catalytic activity of an electrode toward the OER and its tunneling characteristics was found. The use of a scanning tunneling spectroscope (STS) in electrocatalytic testing may increase the efficiency of the optimization of electrochemical processes.

  19. Scanning Tunneling Spectroscope Use in Electrocatalysis Testing

    Directory of Open Access Journals (Sweden)

    Turid Knutsen

    2010-06-01

    Full Text Available The relationship between the electrocatalytic properties of an electrode and its ability to transfer electrons between the electrode and a metallic tip in a scanning tunneling microscope (STM is investigated. The alkaline oxygen evolution reaction (OER was used as a test reaction with four different metallic glasses, Ni78Si8B14, Ni70Mo20Si5B5, Ni58Co20Si10B12, and Ni25Co50Si15B10, as electrodes. The electrocatalytic properties of the electrodes were determined. The electrode surfaces were then investigated with an STM. A clear relationship between the catalytic activity of an electrode toward the OER and its tunneling characteristics was found. The use of a scanning tunneling spectroscope (STS in electrocatalytic testing may increase the efficiency of the optimization of electrochemical processes.

  20. Coupling quantum tunneling with cavity photons.

    Science.gov (United States)

    Cristofolini, Peter; Christmann, Gabriel; Tsintzos, Simeon I; Deligeorgis, George; Konstantinidis, George; Hatzopoulos, Zacharias; Savvidis, Pavlos G; Baumberg, Jeremy J

    2012-05-11

    Tunneling of electrons through a potential barrier is fundamental to chemical reactions, electronic transport in semiconductors and superconductors, magnetism, and devices such as terahertz oscillators. Whereas tunneling is typically controlled by electric fields, a completely different approach is to bind electrons into bosonic quasiparticles with a photonic component. Quasiparticles made of such light-matter microcavity polaritons have recently been demonstrated to Bose-condense into superfluids, whereas spatially separated Coulomb-bound electrons and holes possess strong dipole interactions. We use tunneling polaritons to connect these two realms, producing bosonic quasiparticles with static dipole moments. Our resulting three-state system yields dark polaritons analogous to those in atomic systems or optical waveguides, thereby offering new possibilities for electromagnetically induced transparency, room-temperature condensation, and adiabatic photon-to-electron transfer.

  1. Positioning systems for underground tunnel environments

    CERN Document Server

    Leite Pereira, Fernando; Theis, Christian

    In the last years the world has witnessed a remarkable change in the computing concept by entering the mobile era. Incredibly powerful smartphones have proliferated at stunning pace and tablet computers are capable of running demanding applications and meet new business requirements. Being wireless, localization has become crucial not only to serve individuals but also help companies in industrial and safety processes. In the context of the Radiation Protection group at CERN, automatic localization, besides allowing to find people, would help improving the radiation surveys performed regularly along the accelerator tunnels. The research presented in this thesis attempts to answer questions relatively to the viability of localization in a harsh conditions tunnel: “Is localization in a very long tunnel possible, meeting its restrictions and without incurring prohibitive costs and infrastructure?”, “Can one achieve meter-level accuracy with GSM deployed over leaky-feeder?”, “Is it possible to prototype...

  2. Electrodiagnostic approach to carpal tunnel syndrome

    Directory of Open Access Journals (Sweden)

    Cherian Ajith

    2006-01-01

    Full Text Available An algorithm for an electrophysiological approach to carpal tunnel syndrome is proposed. This technical note takes into account the standard tests, comparison tests and needle electromyography. If the standard tests are negative, a comparison study can be done to identify cases of minimal or very mild carpal tunnel syndrome (CTS. If comparison studies are negative, CTS can be ruled out and a search for other causes have to be made. If the standard tests are positive, carpal tunnel syndrome can be divided into extreme, severe,moderate and mild cases. Motor comparison study is useful in extreme CTS cases. Needle electromyography is a must in all cases where the standard tests are positive. This streamlined approach allows accurate diagnosis with minimum essential tests.

  3. The use of geological data from pilot holes for predicting FPI (full perimeter intersection) fractures

    Energy Technology Data Exchange (ETDEWEB)

    Joutsen, A.

    2012-02-15

    Posiva Oy is responsible for preparation of final disposal of spent nuclear fuel in Olkiluoto. The knowledge about existing network of fractures is important for the safety and feasibility of the final repository. The bedrock properties essential for safety case are analyzed in investigations of Rock Suitability Criteria (RSC). One subtask in RSC is avoidance of large (long) fractures adjacent to disposal holes. The long fractures have been defined in tunnel mapping to indicate tunnel cross-cutting fractures (TCF) or full perimeter intersections (FPI). The purpose for this study was to evaluate the possibility of recognizing FPIs from drill cores by their geological properties. The study was carried out by correlating FPIs mapped from the ONKALO tunnel to the pilot holes logging data with a view of finding out which fracture in the pilot hole corresponds to the FPI in the tunnel. It was also estimated what kind of geological properties does FPIs commonly have in the tunnel and how does these properties differ from the FPI correlated pilot hole fractures. The data sources for this study are the pilot holes from ONK-PH8 to ONK-PH14 and the systematic geological mapping data. The FPIs used in this study usually follow the general trends of the fracturing in the Olkiluoto bedrock. The fracture surface profiles are principally undulating and a striation can be often seen on the fracture surfaces. The FPIs are frequently moderately to intensely altered with diverse filling mineralogy and thick fracture fillings in comparison to the regular fractures. The FPI correlated pilot hole fractures have slightly different properties in comparison to the FPIs. These fractures have wider range of different fracture surface profiles and are slightly less altered than the FPIs. Filling mineralogy follows the trends of the FPIs but filling thicknesses are thinner. These differences probably occur because of the variable uncertainties related to the correlation and to the fact that the

  4. Quantum tunneling from high dimensional G\\"odel black hole

    CERN Document Server

    Li, Hui-Ling; Zu, Xiao-Tao

    2014-01-01

    Considering quantum gravity effect, we investigate the quantum tunneling from high dimensional Kerr-G\\"odel black hole using generalized Dirac equation. As a result, revised tunneling probability is obtained, and the corrected Hawking temperature is also presented.

  5. Carpal tunnel syndrome after 22 years of Colle's fracture

    Directory of Open Access Journals (Sweden)

    Goyal V

    2003-01-01

    Full Text Available Delayed carpal tunnel syndrome is rare. We describe the electrophysiological findings in a patient with Colle's fracture, who developed carpal tunnel syndrome 22 years after a wrist injury.

  6. Carpal tunnel syndrome: an unusual presentation of brachial hypertrophy.

    OpenAIRE

    Shenoy, K. T.; Saha, P. K.; Ravindran, M

    1980-01-01

    A patient with carpal tunnel syndrome in association with congenital hypertrophy of right upper limb is described. The median nerve also showed hypertrophy. The symptoms were relieved by decompression of the carpal tunnel.

  7. A Top Pilot Tunnel Preconditioning Method for the Prevention of Extremely Intense Rockbursts in Deep Tunnels Excavated by TBMs

    Science.gov (United States)

    Zhang, Chuanqing; Feng, Xiating; Zhou, Hui; Qiu, Shili; Wu, Wenping

    2012-05-01

    The headrace tunnels at the Jinping II Hydropower Station cross the Jinping Mountain with a maximum overburden depth of 2,525 m, where 80% of the strata along the tunnels consist of marble. A number of extremely intense rockbursts occurred during the excavation of the auxiliary tunnels and the drainage tunnel. In particular, a tunnel boring machine (TBM) was destroyed by an extremely intense rockburst in a 7.2-m-diameter drainage tunnel. Two of the four subsequent 12.4-m-diameter headrace tunnels will be excavated with larger size TBMs, where a high risk of extremely intense rockbursts exists. Herein, a top pilot tunnel preconditioning method is proposed to minimize this risk, in which a drilling and blasting method is first recommended for the top pilot tunnel excavation and support, and then the TBM excavation of the main tunnel is conducted. In order to evaluate the mechanical effectiveness of this method, numerical simulation analyses using the failure approaching index, energy release rate, and excess shear stress indices are carried out. Its construction feasibility is discussed as well. Moreover, a microseismic monitoring technique is used in the experimental tunnel section for the real-time monitoring of the microseismic activities of the rock mass in TBM excavation and for assessing the effect of the top pilot tunnel excavation in reducing the risk of rockbursts. This method is applied to two tunnel sections prone to extremely intense rockbursts and leads to a reduction in the risk of rockbursts in TBM excavation.

  8. Gauge-independence of tunneling rates

    CERN Document Server

    Plascencia, Alexis D

    2016-01-01

    It is shown that tunneling rates can be defined in terms of a false-vacuum effective action whose reality and convexity properties differ from those of the corresponding groundstate functional. The tunneling rate is directly related to the false-vacuum effective action evaluated at an extremal "quantum bounce". The Nielsen identities of the false-vacuum functional ensure that the rate remains independent of the choice of gauge-fixing. Our results are nonperturbative and clarify issues related with convexity and radiative corrections.

  9. Vibration measurement and modal analysis for tunneller

    Institute of Scientific and Technical Information of China (English)

    HUANG Min; WU Miao; WEI Ren-zhi

    2001-01-01

    In this paper, the method of vibration measurement and modal analysis for AM~50 Tunneller machine is presented. When the machine was used for cutting man-made coal bed and real coal bed, the vibration of the machine was measured and the results of signal analysis show that the vibration characteristics under the two kinds of working situations are similar. The modal model of the machine is established, and then, the intrinsic vibration characteristics of AM50 tunneller are investigated by means of the method of experimental modal analysis. The vibration response simulation under a set of loading spectra measured is carried out by force response simulation software.

  10. Resonant tunneling in graphene pseudomagnetic quantum dots.

    Science.gov (United States)

    Qi, Zenan; Bahamon, D A; Pereira, Vitor M; Park, Harold S; Campbell, D K; Neto, A H Castro

    2013-06-12

    Realistic relaxed configurations of triaxially strained graphene quantum dots are obtained from unbiased atomistic mechanical simulations. The local electronic structure and quantum transport characteristics of y-junctions based on such dots are studied, revealing that the quasi-uniform pseudomagnetic field induced by strain restricts transport to Landau level- and edge state-assisted resonant tunneling. Valley degeneracy is broken in the presence of an external field, allowing the selective filtering of the valley and chirality of the states assisting in the resonant tunneling. Asymmetric strain conditions can be explored to select the exit channel of the y-junction.

  11. Fire Resistant Panels for the Tunnel Linings

    Directory of Open Access Journals (Sweden)

    Gravit Marina

    2016-01-01

    Full Text Available Presents the results of studies of innovative materials in the field of experimental and theoretical research fire resistance fireproof panels Pyro-Safe Aestuver T. Owing to the assembly simplicity, materials cheapness, high ecological standard, recycling, reuse potential, are benefit. Research work is running to improve the knowledge about fireproof panels Pyro-Safe Aestuver T for tunnel lining, its basic performance, its long term behavior and in particular also its fire proof for example when used for the lining of road tunnels.

  12. Microscopic tunneling theory of long Josephson junctions

    DEFF Research Database (Denmark)

    Grønbech-Jensen, N.; Hattel, Søren A.; Samuelsen, Mogens Rugholm

    1992-01-01

    We present a numerical scheme for solving a nonlinear partial integro-differential equation with nonlocal time dependence. The equation describes the dynamics in a long Josephson junction modeled by use of the microscopic theory for tunneling between superconductors. We demonstrate that the detai......We present a numerical scheme for solving a nonlinear partial integro-differential equation with nonlocal time dependence. The equation describes the dynamics in a long Josephson junction modeled by use of the microscopic theory for tunneling between superconductors. We demonstrate...

  13. Polaronic Tunnelling in Organic Triblock Copolymers

    Institute of Scientific and Technical Information of China (English)

    LIU De-Sheng; ZHANG Da-Cheng; XIE Shi-Jie; MEI Liang-Mo

    2005-01-01

    @@ Polaron tunnelling is studied in xPA/nPPP/xPA (PA for polyacetylene and PPP poly (p-phenylene)) triblock copolymer, which has a well-barrier-well structure. An extended tight-binding Hamiltonian including external electric field is adopted. Without electric field, the injected electrons would not extend over the whole copolymer chain but instead be confined in the segments of PA. This is different from the behaviour of the traditional semiconductors. It is found that the polaron can transfer to the potential barrier-PPP segment when the applied electric field reaches a certain value. The critical polaron tunnelling electric fields depend upon the lengths of PPP segments.

  14. Traceable long range scanning tunneling microscopy

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Dimensionally correct and directly traceable measurement is not feasible with conventional scanning tunneling microscopy (STMs) due to severe hysteresis and non-linearity of the commonly applied piezo tube scanners and the very short range.By integrating a custom made probing system based on tunneling current measurement into a commercially available and laser-interferometrically position controlled positioning system, an STM with a principal measuring range of 25 mm×25 mm×5 mm and traceable position measurement has been set-up and tested.

  15. A study for the KAERI research tunnel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.; Hwang, Y. S.; Park, H. S.; Park, S. K.; Park, B. Y.; Bang, K. S.; Kuh, J. H.; Kang, K. H

    1997-12-01

    Major goal of the R and D on the KAERI Research Tunnel in 1997 are 1) concept development of the KAERI research tunnel and its major units 2) computer simulation of facilities 3) study on thermo-hydro mechanical coupling in the vicinity of a waste repository 4) effect of excavated distrubed zone. In addition supplementary site investigation to understand the distribution of stresses in the site was done along with long term monitoring of the water table. (author). 44 refs., 16 tabs., 36 figs

  16. Wind Tunnel Measurements at LM Wind Power

    DEFF Research Database (Denmark)

    Bertagnolio, Franck

    2012-01-01

    This section presents the results obtained during the experimental campaign that was conducted in the wind tunnel at LM Wind Power in Lunderskov from August 16th to 26th, 2010. The goal of this study is to validate the so-called TNO trailing edge noise model through measurements of the boundary...... layer turbulence characteristics and the far-field noise generated by the acoustic scattering of the turbulent boundary layer vorticies as they convect past the trailing edge. This campaign was conducted with a NACA0015 airfoil section that was placed in the wind tunnel section. It is equipped with high...

  17. Prevalence of carpal tunnel syndrome in motorcyclists.

    Science.gov (United States)

    Manes, Harvey R

    2012-05-01

    Carpal tunnel syndrome is prevalent in patients who have a repetitive motion, vibration, or pressure exerted on the wrist joint for an extended period of time. The prevalence of this condition in the general population is approximately 5%. Motorcyclists subject themselves to high levels of vibration from the road and use their wrists to control the motorcycle's brakes, gas intake, and gears via the handlebars. Under these conditions, the author hypothesized that an increased prevalence of carpal tunnel syndrome would be observed in this population.

  18. Treatment of repetitive use carpal tunnel syndrome

    Science.gov (United States)

    Smith, Chadwick F.; Vangsness, C. Thomas; Anderson, Thomas; Good, Wayne

    1995-05-01

    In 1990, a randomized, double-blind study was initiated to evaluate the use of an eight-point conservative treatment program in carpal tunnel syndrome. A total of 160 patients were delineated with symptoms of carpal tunnel syndrome. These patients were then divided into two groups. Both groups were subjected to an ergonomically correct eight-point work modification program. A counterfeit low level laser therapy unit was utilized in Group A, while an actual low level laser therapy unit was utilized in Group B. The difference between Groups A and B was statistically significant in terms of return to work, conduction study improvement, and certain range of motion and strength studies.

  19. Dephasing of quantum tunnelling in molecular nanomagnets

    Institute of Scientific and Technical Information of China (English)

    Zhang Shu-Qun; Chen Zhi-De

    2008-01-01

    Dephasing mechanism of quantum tunnelling in molecular magnets has been studied by means of the spin-coherentstate path integral in a mean field approximation. It is found that the fluctuating uncompensated transverse field from the dipolar-dipolar interaction between molecular magnets contributes a random phase to the quantum interference phase. The resulting transition rate is determined by the average tunnel splitting over the random phase. Such a dephasing process leads to the suppression of quenching due to the quantum phase interference, and to the steps due to odd resonances in hysteresis loop survived, which is in good agreement with experimental observations in molecular nanomagnets Fee and Mn12.

  20. Doka formwork system SL-1 for tunneling. Example: Šentvid tunnel

    OpenAIRE

    Pogačar, Boris

    2006-01-01

    The present work focuses on formwork system SL-1, which was developed by the company Doka - die Schalungstechniker for forming of tunnels and special structures. Formwork in general is presented, along with the methods of tunneling, which are in use today. Doka formwork system SL-1 and its typical parts are described in detail. The use of this formwork system is represented on the example of a cavern in Šentvid tunnel. Discussed are two possible shapes of the cavern: the form of three resembl...

  1. Bias dependent inversion of tunneling magnetoresistance in Fe/GaAs/Fe tunnel junctions

    OpenAIRE

    Moser, J.; Zenger, M.; Gerl, C.; Schuh, D.; Meier, R.; Chen, P.; Bayreuther, G.; Wegscheider, W.; Weiss, D; Lai, C. -H.; Huang, R. -T.; Kosuth, M.; Ebert, H.

    2006-01-01

    We investigated spin dependent transport through Fe/GaAs/Fe tunnel junctions. The tunneling magnetoresistance effect (TMR) was probed for different types of Fe/GaAs interfaces. For interfaces cleaned by hydrogen plasma the TMR effect is increased and observable at room temperature. If an epitaxial Fe/GaAs(001) interface is involved, the tunnel junction exhibits a bias dependent inversion of the TMR effect. This is a first experimental signature for band structure effects at a Fe/GaAs interfac...

  2. Quantum dot resonant tunneling diode single photon detector with aluminum oxide aperture defined tunneling area

    DEFF Research Database (Denmark)

    Li, H.W.; Kardynal, Beata; Ellis, D.J.P.

    2008-01-01

    Quantum dot resonant tunneling diode single photon detector with independently defined absorption and sensing areas is demonstrated. The device, in which the tunneling is constricted to an aperture in an insulating layer in the emitter, shows electrical characteristics typical of high quality...... resonant tunneling diodes. A single photon detection efficiency of 2.1%+/- 0.1% at 685 nm was measured corresponding to an internal quantum efficiency of 14%. The devices are simple to fabricate, robust, and show promise for large absorption area single photon detectors based on quantum dot structures....

  3. Fabrication of magnetic tunnel junctions with epitaxial and textured ferromagnetic layers

    Science.gov (United States)

    Chang, Y. Austin; Yang, Jianhua Joshua

    2008-11-11

    This invention relates to magnetic tunnel junctions and methods for making the magnetic tunnel junctions. The magnetic tunnel junctions include a tunnel barrier oxide layer sandwiched between two ferromagnetic layers both of which are epitaxial or textured with respect to the underlying substrate upon which the magnetic tunnel junctions are grown. The magnetic tunnel junctions provide improved magnetic properties, sharper interfaces and few defects.

  4. Large tunneling magnetoresistance in octahedral Fe3O4 nanoparticles

    OpenAIRE

    Arijit Mitra; Barun Barick; Jeotikanta Mohapatra; Sharma, H.; Meena, S. S.; ASLAM, M.

    2016-01-01

    We have observed large tunneling Magnetoresistance (TMR) in amine functionalized octahedral nanoparticle assemblies. Amine monolayer on the surface of nanoparticles acts as an insulating barrier between the semimetal Fe3O4 nanoparticles and provides multiple tunnel junctions where inter-granular tunneling is plausible. The tunneling magnetoresistance recorded at room temperature is 38% which increases to 69% at 180 K. When the temperature drops below 150 K, coulomb staircase is observed in th...

  5. Dynamic Instability of Tunnel in Blocky Rock Mass

    Institute of Scientific and Technical Information of China (English)

    QI Chengzhi; CHEN Canshou; QIAN Qihu; LUO Jian

    2008-01-01

    The displacements and geometry of the rock blocks and the properties of the rock structure play an important role in the stability of tunnels.Based on the key block model, the dynamic instability analysis of underground tunnel subjected to intensive short-time compressional wave was conducted.The instability of the tunnel caused by the spallation and the inertial effect was distinguished.And the influence of the roof contour curvature of tunnel was also determined.

  6. Numerical analysis of surface subsidence in asymmetric parallel highway tunnels

    Directory of Open Access Journals (Sweden)

    Ratan Das

    2017-02-01

    Full Text Available Tunnelling related hazards are very common in the Himalayan terrain and a number of such instances have been reported. Several twin tunnels are being planned for transportation purposes which will require good understanding for prediction of tunnel deformation and surface settlement during the engineering life of the structure. The deformational behaviour, design of sequential excavation and support of any jointed rock mass are challenging during underground construction. We have raised several commonly assumed issues while performing stability analysis of underground opening at shallow depth. For this purpose, Kainchi-mod Nerchowck twin tunnels (Himachal Pradesh, India are taken for in-depth analysis of the stability of two asymmetric tunnels to address the influence of topography, twin tunnel dimension and geometry. The host rock encountered during excavation is composed mainly of moderately to highly jointed grey sandstone, maroon sandstone and siltstones. In contrast to equidimensional tunnels where the maximum subsidence is observed vertically above the centreline of the tunnel, the result from the present study shows shifting of the maximum subsidence away from the tunnel centreline. The maximum subsidence of 0.99 mm is observed at 4.54 m left to the escape tunnel centreline whereas the maximum subsidence of 3.14 mm is observed at 8.89 m right to the main tunnel centreline. This shifting clearly indicates the influence of undulating topography and in-equidimensional noncircular tunnel.

  7. Consideration of rotational tunneling in rare gas cluster ions

    Science.gov (United States)

    Albertoni, C. R.; Ferguson, A. W. Castleman E. E., Jr.

    1989-04-01

    Tunneling transmission coefficients through rotational barriers are investigated as a function of argon cluster ion size using the WKB approximation. The results indicate that tunneling coefficients corresponding to transmissions of a few percent, extend over time windows of ten orders of magnitude. Hence, a very broad distribution of metastable lifetimes is expected for decay of cluster ions by tunneling through rotational barriers.

  8. Construction Technique of Long-Span Shallow-Buried Tunnel Considering the Optimal Sequence of Pilot-Tunnel Excavation

    OpenAIRE

    Bao Jin; Yang Liu; Changxi Yang; Zhicheng Tan; Jianyang Zhang

    2015-01-01

    Construction technique considering the optimal sequence of pilot-tunnel excavation was investigated in order to ensure the safety of construction process of long-span shallow-buried tunnel. Firstly, optimal comparisons of the effect of different sequence of pilot-tunnel excavation on the ground settlement were implemented by the numerical analysis. Secondly, an optimal construction method was determined and applied to the construction of a practical tunnel. Some key issues and procedure of th...

  9. Alendronate reduced peri-tunnel bone loss and enhanced tendon graft to bone tunnel healing in anterior cruciate ligament reconstruction

    Directory of Open Access Journals (Sweden)

    PPY Lui

    2013-01-01

    Full Text Available Peri-tunnel bone loss after anterior cruciate ligament (ACL reconstruction is commonly observed, both clinically and experimentally. We aimed to study the effect and mechanisms of different doses of alendronate in the reduction of peri-tunnel bone loss and promotion of graft-bone tunnel healing in ACL reconstruction. Eighty-four ACL-reconstructed rats were divided into 4 groups. Alendronate at different dosages, or saline, were injected subcutaneously weekly, for 2 or 6 weeks post-reconstruction, for vivaCT (computed tomography imaging, biomechanical tests, histology and immunohistochemistry. Alendronate significantly increased bone mass and density of tissue inside bone tunnels except at the epiphyseal region of tibial tunnel. The femoral tunnel diameter decreased significantly in the mid-dose and high-dose alendronate groups compared to that in the saline group at week 6. Alendronate significantly increased the peri-tunnel bone mass and density along all tunnel regions at week 6. Better graft-bone tunnel integration and intra-tunnel graft integrity were observed in the alendronate groups. The ultimate load was significantly higher in the mid-dose and high-dose alendronate groups at week 2, but not at week 6. There was a reduction in matrix metalloprotein (MMP1, MMP13 and CD68-positive cells at the peri-tunnel region and graft-bone interface in the alendronate-treated group compared to the saline group. Alendronate reduced peri-tunnel bone resorption, increased mineralised tissue inside bone tunnel as well as histologically and biomechanically promoted graft-bone tunnel healing, probably by reducing the expression of MMP1, MMP13 and CD68-positive cells. Alendronate might be used for reducing peri-tunnel bone loss and promoting graft-bone tunnel healing at early stage post-ACL reconstruction.

  10. High non-anatomic tunnel position rates in ACL reconstruction failure using both transtibial and anteromedial tunnel drilling techniques.

    Science.gov (United States)

    Jaecker, Vera; Zapf, Tabea; Naendrup, Jan-Hendrik; Pfeiffer, Thomas; Kanakamedala, Ajay C; Wafaisade, Arasch; Shafizadeh, Sven

    2017-07-18

    Although it is well known from cadaveric and biomechanical studies that transtibial femoral tunnel (TT) positioning techniques are associated with non-anatomic tunnel positions, controversial data exist as so far no clinical differences could have been found, comparing transtibial with anteromedial techniques (AM). The purpose of the study was to analyze if graft failure following TT ACL reconstruction was more commonly associated with non-anatomic tunnel position in comparison with the AM technique. We hypothesized that, compared to AM techniques, non-anatomic tunnel positions correlate with TT tunnel positioning techniques. A total of 147 cases of ACL revision surgery were analyzed retrospectively. Primary ACL reconstructions were analyzed regarding the femoral tunnel drilling technique. Femoral and tibial tunnel positions were determined on CT scans using validated radiographic measurement methods. Correlation analysis was performed to determine differences between TT and AM techniques. A total of 101 cases were included, of whom 64 (63.4%) underwent the TT technique and 37 (36.6%) the AM technique for primary ACL reconstruction. Non-anatomic femoral tunnel positions were found in 77.2% and non-anatomical tibial tunnel positions in 40.1%. No correlations were found comparing tunnel positions in TT and AM techniques, revealing non-anatomic femoral tunnel positions in 79.7 and 73% and non-anatomic tibial tunnel positions in 43.7 and 35.1%, respectively (p > 0.05). Considerable rates of non-anatomic femoral and tibial tunnel positions were found in ACL revisions with both transtibial and anteromedial femoral drilling techniques. Despite the potential of placing tunnels more anatomically using an additional AM portal, this technique does not ensure anatomic tunnel positioning. Consequently, the data highlight the importance of anatomic tunnel positioning in primary ACL reconstruction, regardless of the applied drilling technique.

  11. Colloquium on mine shaft, roadway and tunnel. Proceedings; Kolloquium Schacht, Strecke und Tunnel 2005. Tagungsband

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    The conference intended to outline the economic mechanisms of the coal sector and to show the importance of mining and tunneling and the competence in problem solving acquired in this area. Efficient and sustainable use of domestic reserves may help to ensure long-term supply and keep prices stable. Most of the required infrastructure will be located underground in this highly populated country. Technologies of tunneling and horizontal drilling are described and illustrated by the example of a new Cologne underground railway project. Mining and tunnelling have much in common, e.g. drilling and shotfiring, overburden removal, rock strength, supports, protection against liquid and gas leakage, ventilation and air conditioning. Projects like the new Austrian high-speed railway track or the 'Loetschbergbasistunnel' project in Switzerland are examples of tunneling project which are clearly comparable with the construction of a new coal mine.

  12. Tunneling methods used at the railway tunnels construction in Slovak republic

    Directory of Open Access Journals (Sweden)

    Jozef Čížik

    2007-10-01

    Full Text Available Rail transport is an energy-efficient and capital-intensive means of mechanized land transport. Methods of tunneling vary with the nature of the material to be cut through. When soft earth is encountered, the excavation is timbered for support as the work advances; the timbers are sometimes left as a permanent lining for the tunnel. Another method is to cut two parallel excavations in which the side walls are constructed first. Arches connecting them are then built as the material between them is extracted. Portions of the unexcavated center, left temporarily for support, may be removed later. A tunnel cut through rock frequently requires no lining. Often, to speed construction, work is started at both ends. This poses no problem with the cut-and-cover method, but when the tunnel is bored from within, it must be assured that the tubes will actually meet in the center. Modern methods accomplish this with high precision.

  13. Asymmetric voltage behavior of the tunnel magnetoresistance in double barrier magnetic tunnel junctions

    KAUST Repository

    Useinov, Arthur

    2012-06-01

    In this paper, we study the value of the tunnel magnetoresistance (TMR) as a function of the applied voltage in double barrier magnetic tunnel junctions (DMTJs) with the left and right ferromagnetic (FM) layers being pinned and numerically estimate the possible difference of the TMR curves for negative and positive voltages in the homojunctions (equal barriers and electrodes). DMTJs are modeled as two single barrier junctions connected in series with consecutive tunneling (CST). We investigated the asymmetric voltage behavior of the TMR for the CST in the range of a general theoretical model. Significant asymmetries of the experimental curves, which arise due to different annealing regimes, are mostly explained by different heights of the tunnel barriers and asymmetries of spin polarizations in magnetic layers. © (2012) Trans Tech Publications.

  14. Anomalous Tunnel Magnetoresistance and Spin Transfer Torque in Magnetic Tunnel Junctions with Embedded Nanoparticles

    Science.gov (United States)

    Useinov, Arthur; Ye, Lin-Xiu; Useinov, Niazbeck; Wu, Te-Ho; Lai, Chih-Huang

    2015-12-01

    The tunnel magnetoresistance (TMR) in the magnetic tunnel junction (MTJ) with embedded nanoparticles (NPs) was calculated in range of the quantum-ballistic model. The simulation was performed for electron tunneling through the insulating layer with embedded magnetic and non-magnetic NPs within the approach of the double barrier subsystem connected in parallel to the single barrier one. This model can be applied for both MTJs with in-plane magnetization and perpendicular one. We also calculated the in-plane component of the spin transfer torque (STT) versus the applied voltage in MTJs with magnetic NPs and determined that its value can be much larger than in single barrier system (SBS) for the same tunneling thickness. The reported simulation reproduces experimental data of the TMR suppression and peak-like TMR anomalies at low voltages available in leterature.

  15. Resonant tunnel magnetoresistance in double-barrier planar magnetic tunnel junctions

    KAUST Repository

    Useinov, A. N.

    2011-08-24

    We present a theoretical approach to calculate the spin-dependent current and tunnel magnetoresistance (TMR) in a double-barrier magnetic tunnel junction (DMTJ), in which the magnetization of the middle ferromagnetic metal layer can be aligned parallel or antiparallel in relation to the fixed magnetizations of the left and right ferromagnetic electrodes. The electron transport through the DMTJ is considered as a three-dimensional problem, taking into account all transmitting electron trajectories as well as the spin-dependent momentum conservation law. The dependence of the transmission coefficient and spin-polarized currents on the applied voltage is derived as an exact solution to the quantum-mechanical problem for the spin-polarized transport. In the range of the developed physical model, the resonant tunneling, nonresonant tunneling, and enhanced spin filtering can be explained; the simulation results are in good agreement with experimental data.

  16. The overshoot problem in inflation after tunneling

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, Koushik; Vaudrevange, Pascal M.; Westphal, Alexander

    2011-09-15

    We show the absence of the usual parametrically large overshoot problem of small-field inflation if initiated by a Coleman-De Luccia (CDL) tunneling transition from an earlier vacuum in the limit of small inflationary scale compared to the tunneling scale. For low-power monomial exit potentials V({phi}){proportional_to} {phi}{sup n}; n<4, we derive an expression for the amount of overshoot. This is bounded from above by the width of the steep barrier traversed after emerging from tunneling and before reaching a slow-roll region of the potential. For n{>=}4 we show that overshooting is entirely absent. We extend this result through binomials to a general potential written as a series expansion, and to the case of arbitrary finite initial speed of the inflaton. This places the phase space of initial conditions for small-field and large-field inflation on the same footing in a landscape of string theory vacua populated via CDL tunneling. (orig.)

  17. Cooling of suspended nanostructures with tunnel junctions

    OpenAIRE

    Koppinen, P. J.; Maasilta, I. J.

    2009-01-01

    We have investigated electronic cooling of suspended nanowires with SINIS tunnel junction coolers. The suspended samples consist of a free standing nanowire suspended by four narrow ($\\sim$ 200 nm) bridges. We have compared two different cooler designs for cooling the suspended nanowire. We demonstrate that cooling of the nanowire is possible with a proper SINIS cooler design.

  18. Dissipative tunneling of deuterons in Palladium Deuterides

    Science.gov (United States)

    Sinha, K. P.; Hagelstein, Peter

    2001-03-01

    Decisive experimental evidence exists(B.N.Ganguly,Phys.Rev. B14), 3848(1976). for optical phonons being involved in charged particle-phonon interaction in PdD. We consider the tunneling of charged defects (D^+ or D^-) in a two-state system(K.P.Sinha,Mod.Phys.Lett. B1), 805 (1998)^, (P.L.Hagelstein,To be published.)^,(U.Weiss, \\underline Quantum) \\underline Dissipative \\underline Systems (World Scientific, Singapore, 1999).. The two minima of the potential energy are taken to be asymetrical to reflect the real situation occurring in the solid matrix with defects. A pseudospin formalism is used in which the charged particle interacts with conduction electrons as well as optical phonons. The renormalization effects of the tunneling matrix elements due to interaction with electrons and optical phonons are taken into account. The tunneling rate is derived for both coherent and incoherent situations at finite temperatures. The expressions contain factors which show the emission(absorption) of phonons depending on the direction of the tunneling process. Thus the moving deuteron flux stimulates the generation of optical phonons.

  19. A Student-Built Scanning Tunneling Microscope

    Science.gov (United States)

    Ekkens, Tom

    2015-01-01

    Many introductory and nanotechnology textbooks discuss the operation of various microscopes including atomic force (AFM), scanning tunneling (STM), and scanning electron microscopes (SEM). In a nanotechnology laboratory class, students frequently utilize microscopes to obtain data without a thought about the detailed operation of the tool itself.…

  20. 3D numerical design of tunnel hood

    CERN Document Server

    Uystepruyst, David; Monnoyer, François

    2015-01-01

    This paper relates to the parametric study of tunnel hoods in order to reduce the shape, i.e the temporal gradient, of the pressure wave generated by the entry of a High speed train in tunnel. This is achieved by using an in-house three-dimensional numerical solver which solves the Eulerian equations on a Cartesian and unstructured mesh. The efficiency of the numerical methodology is demonstrated through comparisons with both experimental data and empirical formula. For the tunnel hood design, three parameters, that can influence the wave shape, are considered: the shape, the section and the length of the hood. The numerical results show, (i) that a constant section hood is the most efficient shape when compared to progressive (elliptic or conical) section hoods, (ii) an optimal ratio between hood's section and tunnel section where the temporal gradient of the pressure wave can be reduced by half, (iii) a significant efficiency of the hood's length in the range of 2 to 8 times the length of the train nose. Fi...

  1. Tunnel Diode Discriminator with Fixed Dead Time

    DEFF Research Database (Denmark)

    Diamond, J. M.

    1965-01-01

    A solid state discriminator for the range 0.4 to 10 V is described. Tunnel diodes are used for the discriminator element and in a special fixed dead time circuit. An analysis of temperature stability is presented. The regulated power supplies are described, including a special negative resistance...

  2. Bilateral carpal tunnel syndrome in Graves' disease.

    Science.gov (United States)

    Manganelli, P; Pavesi, G; Salaffi, F

    1987-01-01

    Carpal tunnel syndrome (CTS) may be associated with endocrinopathies, such as hypothyroidism and acromegaly. A direct relationship between CTS and hyperthyroidism has recently been suggested. We now report a case in which bilateral CTS developed after treatment of Graves' disease, thus, questioning the possibility of a relationship between these two disease processes.

  3. SCANNING TUNNELING MICROSCOPY STUDIES ON OPTICAL DISC

    Institute of Scientific and Technical Information of China (English)

    徐磊; 顾冬红; 等

    1994-01-01

    Scanning tunneling microscope(STM) is used to investigate the optical dise.The areas with and without data stampers are all observedcarefully.Three-dimensional images of the disc surface clearly demonstrate the period.depth of the grooves and the shape of data stampers.Some phenomena of STM imaging are also discussed.

  4. Single electron tunneling based arithmetic computation

    NARCIS (Netherlands)

    Lageweg, C.R.

    2004-01-01

    In this dissertation we investigate the implementation of computer arithmetic operations with Single Electron Tunneling (SET) technology based circuits. In our research we focus on the effective utilization of the SET technologys specific characteristic, i.e., the ability to control the transport of

  5. Towards high-speed scanning tunneling microscopy

    NARCIS (Netherlands)

    Tabak, Femke Chantal

    2013-01-01

    In this thesis, two routes towards high-speed scanning tunneling microscopy (STM) are described. The first possibility for high-speed scanning that is discussed is the use of MEMS (Micro-Electro Mechanical Systems) devices as high-speed add-ons in STM microscopes. The functionality of these devices

  6. Enhanced Tunnelling Models for Child Universe Formation

    CERN Document Server

    Ansoldi, S; Shilon, I

    2015-01-01

    Starting from a recently proposed model that allows for an enhanced rate of child universe production under generic conditions, we elaborate on refinements that may allow for non-singular initial configurations. A possibility to treat both, the initial state and the tunnelling beyond the semiclassical level will also be introduced.

  7. A Student-Built Scanning Tunneling Microscope

    Science.gov (United States)

    Ekkens, Tom

    2015-01-01

    Many introductory and nanotechnology textbooks discuss the operation of various microscopes including atomic force (AFM), scanning tunneling (STM), and scanning electron microscopes (SEM). In a nanotechnology laboratory class, students frequently utilize microscopes to obtain data without a thought about the detailed operation of the tool itself.…

  8. Radiologic placement of tunneled central venous catheter

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, Seong Tae; Yang, Po Song; Yang, Dong Hunn; Kim, Ki Tae; Kim, Choon Yul; Shinn, Kyung Sub [The Catholic Univ. College of Medicine, Seoul (Korea, Republic of); Yun, Eun Joo [Korea Veterans Hospital, Seoul (Korea, Republic of)

    1996-01-01

    To evaluate the efficacy and safety of fluoroscopy-guided, radiologic placement of a tunneled central venous catheter into the superior vena cava (SVC). Thirty five patients underwent tunneled central venous catheter placement to facilitate long-term chemotherapy. They included 33 leukemic patients, one colon cancer patient, and one multiple myeloma patient. After confirming central venous patency with a injection of contrast media via the peripheral cephalic or basilic vein in the wrist joint, the subclavian vein was punctured under fluoroscopic guidance. A 7F double lumen TPN catheter was placed into the SVC through a subcutaneous tunnel in the anterior chest wall. Catheter placements were successful in all patients. The mean procedure time was 17.2minutes, mean fluooscopy time was 1.3minutes, mean number of punctures was 1.4, and mean volume of injhected contrast media was 43.5cc. Only two of all leukemic patients developed mild hematomas at the puncture site, but these soon resolved themselves. None of the patients developed pneumothorax or hemothorax. But late complications included local infection in two patients (6%) and thrombotic occlusion of the catheter in one (3%). The occluded catheter was successfully recanalized with Urokinase infusion. Fluoroscopy-guided, radiologic placement of a tunneled central venous catheter is an easy and safe method, and useful for patients requiring long-term venous access.

  9. Fire safety assessment of tunnel structures

    DEFF Research Database (Denmark)

    Gkoumas, Konstantinos; Giuliani, Luisa; Petrini, Francesco

    2011-01-01

    .g. structural and non structural, organizational, human behavior). This is even more truth for the fire safety design of such structures. Fire safety in tunnels is challenging because of the particular environment, bearing in mind also that a fire can occur in different phases of the tunnel’s lifecycle. Plans...... of nonlinear analyses for different fire exposures....

  10. Integrated tunneling sensor for nanoelectromechanical systems

    DEFF Research Database (Denmark)

    Sadewasser, S.; Abadal, G.; Barniol, N.

    2006-01-01

    distances, attractive van der Waals and capillary forces become sizable, possibly resulting in snap-in of the electrodes. The authors present a comprehensive analysis and evaluation of the interplay between the involved forces and identify requirements for the design of tunneling sensors. Based...

  11. Tunneling spectra of graphene on copper unraveled

    DEFF Research Database (Denmark)

    Zhang, Xin; Stradi, Daniele; Liu, Lei

    2016-01-01

    mechanisms, etc. The interpretation of the spectra can be complicated, however. Specifically for graphene grown on copper, there have been conflicting reports of tunneling spectra. A clear understanding of the mechanisms behind the variability is desired. In this work, we have revealed that the root cause...

  12. Planar Tunneling Spectroscopy of Graphene Nanodevices

    Science.gov (United States)

    Wang, Joel I.-Jan; Bretheau, Landry; Pisoni, Riccardo; Watanabe, Kenji; Taniguchi, Takashi; Jarillo-Herrero, Pablo

    2-D Van-der-Waals mesoscopic physics have seen a rapid development in the last 10 years, with new materials each year added to the toolbox. Stacking them like Lego enables the combination of their individual electronic properties. In particular, hexagonal boron nitride, which is an insulator, gives the possibility to perform planar (2-D to 2-D) tunneling spectroscopy within this type of heterostructures. Unlike standard transport measurements, tunneling spectroscopy enables to probe the electronic properties in the energy domain. Moreover, since planar tunneling probes a large area of the system, global quantum features such as quantum Hall effect, superconducting proximity effect or quantum confinement can be investigated. In this talk, we will present implementation of heterostructures consisting of graphene, hexagonal boron nitride, and graphite, fabricated for planar tunneling spectroscopy. In order to reveal the intrinsic properties of materials, the fabrication scheme aims at preserving the pristine nature of the 2-DEGS as well as minimizing the doping introduced by external probes. As a demonstration, measurements of these devices in normal states, high magnetic field environment, and induced superconducting state will be presented.

  13. Carpal Tunnel Syndrome in ARL Libraries.

    Science.gov (United States)

    Thornton, Joyce K.

    1997-01-01

    A survey of 72 member libraries in the Association of Research Libraries revealed the incidence of carpal tunnel syndrome (CTS) and the measures taken to cope with it. Recommends implementing proactive ergonomics programs; soliciting staff input for solutions; providing report guidelines; using external help; stressing preventive measures and…

  14. Employees' Knowledge of Carpal Tunnel Syndrome.

    Science.gov (United States)

    Gandy-Goldston, Terrie M.

    A study examined employees' knowledge of the causes of carpal tunnel syndrome (CTS), its prevention, and their legal rights after being diagnosed with CTS. A 24-item questionnaire was administered to a random sample of 30 Chicago-area employees who had been afflicted with CTS. Of those surveyed, 99% considered their CTS injury related to their…

  15. An Optimization Model of Tunnel Support Parameters

    Directory of Open Access Journals (Sweden)

    Su Lijuan

    2015-05-01

    Full Text Available An optimization model was developed to obtain the ideal values of the primary support parameters of tunnels, which are wide-ranging in high-speed railway design codes when the surrounding rocks are at the III, IV, and V levels. First, several sets of experiments were designed and simulated using the FLAC3D software under an orthogonal experimental design. Six factors, namely, level of surrounding rock, buried depth of tunnel, lateral pressure coefficient, anchor spacing, anchor length, and shotcrete thickness, were considered. Second, a regression equation was generated by conducting a multiple linear regression analysis following the analysis of the simulation results. Finally, the optimization model of support parameters was obtained by solving the regression equation using the least squares method. In practical projects, the optimized values of support parameters could be obtained by integrating known parameters into the proposed model. In this work, the proposed model was verified on the basis of the Liuyang River Tunnel Project. Results show that the optimization model significantly reduces related costs. The proposed model can also be used as a reliable reference for other high-speed railway tunnels.

  16. Prismatic Blade Measuring on a Wind Tunnel

    Directory of Open Access Journals (Sweden)

    Stech J.

    2013-04-01

    Full Text Available The results from measurement on the straight blade cascade are presented in the paper. The cascade is placed at the outlet of wind tunnel in ŠKODA POWER experimental base. The results in the form of velocity and loss fields behind blade cascade as well as the distribution of the loss coefficient in selected cross-section are evaluated.

  17. Theoretical Analysis of Reinforcement Tunnel Lining Corrosion

    Directory of Open Access Journals (Sweden)

    ZhiQiang Zhangand

    2013-05-01

    Full Text Available The main cause of ageing damage in reinforced concrete structures is reinforcement corrosion. Damage can be detected visually as coincident cracks along the reinforcement bar, which are significant of both reduction of the re-bar, cross-section and loss of bond strength for reinforced concrete. The reinforced concrete is one of the most widely used engineering materials as final lining of tunnels. The corrosion is common durability problems that have significant effect on the tunnel performance. This study intends to analysis reinforcement concrete corrosion at the tunnel lining by applying temperature expansion theory on steel through numerical simulation process, with expansive force effect. The thickness of concrete cover and the diameter of steel bar have an impact on the stress for reinforcement concrete during propagation of corrosion process. The corrosion cracks appear at the corner of a tunnel lining then in invert and vault because the maximum stress will be in the corner then in invert and vault. The internal force in the concrete lining changes differently when the corrosion rate change.

  18. Hemodialysis Tunneled Catheter-Related Infections

    Science.gov (United States)

    Miller, Lisa M.; Clark, Edward; Dipchand, Christine; Hiremath, Swapnil; Kappel, Joanne; Kiaii, Mercedeh; Lok, Charmaine; Luscombe, Rick; Moist, Louise; Oliver, Matthew; MacRae, Jennifer

    2016-01-01

    Catheter-related bloodstream infections, exit-site infections, and tunnel infections are common complications related to hemodialysis central venous catheter use. The various definitions of catheter-related infections are reviewed, and various preventive strategies are discussed. Treatment options, for both empiric and definitive infections, including antibiotic locks and systemic antibiotics, are reviewed.

  19. Decompression of magma into repository tunnels

    NARCIS (Netherlands)

    Bokhove, Onno; Woods, A.W.

    2002-01-01

    It is nontrivial to find and design safe repository sites for nuclear waste. It appears common sense to drill tunnels as repository sites in a mountain in remote and relatively dry regions. However, erosion of the waste canisters by naturally abundant chemicals in the mountains water cycle remains a

  20. ENGINEERING GEOLOGY PROPERTIES OF 'KONJSKO' TUNNEL

    Directory of Open Access Journals (Sweden)

    Ivan Grabovac

    2004-12-01

    Full Text Available Investigation works for the design of the Konjsko Tunnel with two pipes, part of the Split-Zagreb Motorway, provided relevant data on rock mass and soil properties for construction of the prognose engineering-geological longitudinal sections. West tunnel portals are situated in tectonically deformed and partly dynamically metamorphosed Eocene flysch marls, while east ones are located in Senonian limestones. There is an overthrust contact between flysch marls and limestones. With the beginning of the excavations, rock mass characteristics were regularly registered after each blasting and actual longitudinal engineering-geological cross-sections were constructed as well as cross-sections of the excavation face. There were some differences between prognosticated and registered sections since it was infeasible to accurately determine the dip of the overthrust plane that was at shallow depth below the tunnel grade line and also due to the occurrence of transversal faults that intersected the overthrust. Data collected before and during the tunnel construction complemented the knowledge on geological structure of the surroundings and physical-mechanical characteristics of strata (the paper is published in Croatian.

  1. Explosion risks and consequences for tunnels

    NARCIS (Netherlands)

    Weerheijm, J.; Berg, A.C. van den

    2014-01-01

    Tunnel accidents with transports of dangerous goods may lead to explosions. Risk assessment for these accidents is complicated because of the low probability and the unknown, but disastrous effects expected. Especially the lack of knowledge on the strength of the explosion and the consequences for t

  2. PRACTICAL DETERMINATION OF TUNNEL ENTRANCE LIGHTING NEEDS

    NARCIS (Netherlands)

    SCHREUDER, DA

    1991-01-01

    The determination of the field factor that relates the visibility conditions in the laboratory to the visibility conditions for a car driver approaching the entrance of a long tunnel is discussed. Experimental results are given from research in the netherlands. Suggestions are given for incorporatio

  3. B-Target Room Tunnel Redesigned

    Energy Technology Data Exchange (ETDEWEB)

    Esfandiari, Reza; /San Jose State U. /SLAC

    2010-08-25

    Several groups at SLAC National Accelerator Laboratory are currently working on a RF Modulator prototype for a future linear collider known as the International Linear Collider (ILC). The ILC runs using about a 1000 Klystrons which create high power carrier waves for the particle acceleration. Klystrons receive their electrical input power from modulators. In order to move beyond the prototype phase, the laboratory might expand its ground base further down a tunnel located at the End Station B (ESB) in order to house four new Klystron Modulator Test Stations. This area is known as the B-Target Room Tunnel, and the task was to redesign the tunnel layout for the upcoming changes. The project first began by collecting substantial amount of information about the prototyped project, the tunnel and the researchers feedback of what they would like to see in the upcoming design. Subsequent to numerous planning and presentations, one particular design was. Calculations for this design were then performed for the most complex aspects of the project. Based on the results of the calculations, specific sample beams, welds, bolts and materials were chosen for the possible future construction.

  4. High-Performance Single Nanowire Tunnel Diodes

    DEFF Research Database (Denmark)

    Wallentin, Jesper; Persson, Johan Mikael; Wagner, Jakob Birkedal

    2010-01-01

    We demonstrate single nanowire tunnel diodes with room temperature peak current densities of up to 329 A/cm(2). Despite the large surface to volume ratio of the type-II InP-GaAs axial heterostructure nanowires, we measure peak to valley current ratios (PVCR) of up to 8.2 at room temperature and 2...

  5. Resonant tunneling in a pulsed phonon field

    DEFF Research Database (Denmark)

    Kral, P.; Jauho, Antti-Pekka

    1999-01-01

    , The nonequilibrium spectral function for the resonance displays the formation and decay of the phonon sidebands on ultrashort time scales. The time-dependent tunneling current through the individual phonon satellites reflects this quasiparticle formation by oscillations, whose time scale is set by the frequency...

  6. Electric field modulation of tunneling anisotropic magnetoresistance in tunnel junctions with antiferromagnetic electrodes

    Science.gov (United States)

    Goto, Minori; Nawaoka, Kohei; Miwa, Shinji; Hatanaka, Shohei; Mizuochi, Norikazu; Suzuki, Yoshishige

    2016-08-01

    We present electric field modulation of tunneling anisotropic magnetoresistance (TAMR) in MnIr|MgO|Ta tunnel junctions. TAMR enables direct observation of the antiferromagnetic spin direction at the MnIr|MgO interface. We found that the shape of magnetoresistance (MR) curve can be modulated by an electric field, which can be explained by electric field modulation of the interfacial magnetic anisotropy at MnIr|MgO.

  7. The Time and Cost Prediction of Tunnel Boring Machine in Tunnelling

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Making use of microsoft visual studio. net platform, the assistant decision-making system of tunnel boring machine in tunnelling has been built to predict the time and cost. Computation methods of the performance parameters have been discussed. New time and cost prediction models have been depicted. The multivariate linear regression has been used to make the parameters more precise, which are the key factor to affect the prediction near to the reality.

  8. Highly doped layer for tunnel junctions in solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Fetzer, Christopher M.

    2017-08-01

    A highly doped layer for interconnecting tunnel junctions in multijunction solar cells is presented. The highly doped layer is a delta doped layer in one or both layers of a tunnel diode junction used to connect two or more p-on-n or n-on-p solar cells in a multijunction solar cell. A delta doped layer is made by interrupting the epitaxial growth of one of the layers of the tunnel diode, depositing a delta dopant at a concentration substantially greater than the concentration used in growing the layer of the tunnel diode, and then continuing to epitaxially grow the remaining tunnel diode.

  9. Mutual seismic interaction between tunnels and the surrounding granular soil

    Directory of Open Access Journals (Sweden)

    Mohamed Ahmed Abdel-Motaal

    2014-12-01

    Study results show that the maximum exerted straining actions in tunnel lining are directly proportional to the relative stiffness between tunnel and surrounding soil (lining thickness and soil shear modulus. Moreover, it is highly affected by the peak ground acceleration and the tunnel location (embedment depth. A comprehensive study is performed to show the effect of tunnel thickness and tunnel diameter on both the induced bending moment and lining deformation. In general, it is concluded that seismic analysis should be considered in regions subjected to peak ground acceleration greater than 0.15g.

  10. Engineering geology and geomechanics in dam and tunnel construction

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, L. (ed.)

    1981-01-01

    Papers presented at this conference included planning of road tunnels, geological and geotechnical exploration for tunnels, determination of rock mass strength of sedimentary rocks, geomechanical assessment and foundation problems of dams, excavation of mine roadways, movement and stress phenomena in rock strata resulting from hard coal mining, effects of rock bolts and thin linings as tunnel supports, system bolting in deep underground rock excavations, highly stressed areas in tunnels and damage in tunnelling. Papers are either in German or in English. Two papers have been previously abstracted.

  11. Pathogenesis and electrodiagnosis of cubital tunnel syndrome

    Institute of Scientific and Technical Information of China (English)

    贾志荣; 石昕; 孙相如

    2004-01-01

    Background Cubital tunnel syndrome is a well-recognized clinical condition and is the second most common peripheral compression neuropathy. This study was designed to investigate the causes of cubital tunnel syndrome by surgical means and to assess the clinical value of the neurophysiological diagnosis of cubital tunnel syndrome. Methods Twenty-one patients (involving a total of 22 limbs from 16 men and 5 women, aged 22 to 63, with a mean age of 49 years) with clinical symptoms and signs indicating a problem with their ulnar nerve underwent motor conduction velocity examinations at different sites along the ulnar nerve and examinations of sensory conduction velocity in the hand, before undergoing anterior transposition of the ulnar nerve.Results Electromyographic abnormalities were seen in 21 of 22 limbs [motor nerve conduction velocity (MCV) range (15.9-47.5) m/s, mean 32.7 m/s] who underwent motor conduction velocity examinations across the elbow segment of the ulnar nerve. Reduced velocity was observed in 13 of 22 limbs [MCV (15.7-59.6) m/s, mean 40.4 m/s] undergoing MCV tests in the forearms. An absent or abnormal sensory nerve action potential following stimulation was detected in the little finger of 14 of 22 limbs. The factors responsible for ulnar compression based on observations made during surgery were as follows: 15 cases involved compression by arcuate ligaments, muscle tendons, or bone hyperplasia; 2 involved fibrous adhesion; 3 involved compression by the venous plexus or a concurrent thick vein; 2 involved compression by cysts. Conclusions Factors inducing cubital tunnel syndrome include both common factors that have been reported and rare factors, involving the venous plexus, thick veins, and cysts. Tests of motor conduction velocity at different sites along the ulnar nerve should be helpful in diagnosis cubital tunnel syndrome, especially MCV tests indicating decreased velocity across the elbow segment of the ulnar nerve.

  12. Outcome of radiologically placed tunneled haemodialysis catheters.

    Science.gov (United States)

    Sayani, Raza; Anwar, Muhammad; Tanveer-ul-Haq; Al-Qamari, Nauman; Bilal, Muhammad Asif

    2013-12-01

    To study the outcome of radiologically placed double lumen tunneled haemodialysis catheters for the management of renal failure. Case series. Interventional Suite of Radiology Department at the Aga Khan University Hospital, Karachi, from April 2010 to June 2011. All consecutive patients who were referred to the department of radiology by the nephrologists for double lumen tunneled haemodialysis catheter (Permacath) placement during the study period were included. Patients with septicemia, those for whom follow-up was not available, those coming for catheter exchange or who died due to a noncatheter related condition were excluded. A radio-opaque, soft silicone double lumen catheter was inserted through a subcutaneous tunnel created over the anterior chest wall. The catheter tip was placed in the right atrium via the internal jugular vein. Ultrasound guidance was used for initial venous puncture. The rest of the procedure was carried out under fluoroscopic guidance. Technical success, catheter related bacteremia rates, adequacy of dialysis, patency, and adverse events were analyzed. Overall 88 tunneled haemodialysis catheters were placed in 87 patients. Patients were followed-up for duration of 1 - 307 days with mean follow-up period of 4 months. Immediate technical success was 100%. The procedural complication rate was 5.6% (5 catheters). Eight patients died during the study period, seven from causes unrelated to the procedure. One patient died due to septicemia secondary to catheter related infection. Of the remaining 69 patients, 50 (72.4%) predominantly had uneventful course during the study period. Twelve patients developed infection (17.3%); two were successfully treated conservatively while in 10 patients catheter had to be removed. Seven catheters (10.1%) failed due to mechanical problems. In 3 patients the internal jugular veins got partially thrombosed. One catheter was accidentally damaged in the ward and had to be removed. Radiological guided tunneled

  13. Thermal creation of a spin current by Seebeck spin tunneling

    Science.gov (United States)

    Jansen, R.; Le Breton, J. C.; Deac, A. M.; Saito, H.; Yuasa, S.

    2013-09-01

    The thermoelectric analog of spin-polarized tunneling, namely Seebeck spin tunneling, is a recently discovered phenomenon that arises from the spin-dependent Seebeck coefficient of a magnetic tunnel contact. In a tunnel junction with one ferromagnetic electrode and one non-magnetic electrode, a temperature difference between the two electrodes creates a spin current across the contact. Here, the basic principle and the observation of Seebeck spin tunneling are described. It is shown how it can be used to create a spin accumulation in silicon driven by a heat flow across a magnetic tunnel contact, without a charge tunnel current. The sign of the spin current depends on the direction of the heat flow, whereas its magnitude is anisotropic, i.e., dependent on the absolute orientation of the magnetization of the ferromagnet. The connection between Seebeck spin tunneling and the tunnel magneto-Seebeck effect, observed in metal magnetic tunnel junctions, is also clarified. Seebeck spin tunneling may be used to convert waste heat into useful thermal spin currents that aid or replace electrical spin current, and thereby improve the energy efficiency of spintronic devices and technologies.

  14. Monitoring of Deformation in Ground Before and After Tunnel Excavation

    Science.gov (United States)

    Eren, Mehmet; Hilmi Erkoç, Muharrem

    2017-04-01

    As population increase in metropolitan city, we need transportation and transmission tunnel. In this context, the engineers and administors attach impotance to building and planning underground-tunnel. Moreover, we must at regular intervals monitoring to deformation in underground-tunnel for quality and safety. Firstly, a deformation monitoring network is designed as perpendicular to the tunnel main axis. Secondly, the prescribed number of deformation measurements must be made. Finally, the deformation analysis is evaluated and its results is interpreted. This study investigates how deformation in monitoring network during and after tunnel excavate change.For this purpose, a deformation monitoring network of 18 object point and 4 reference point was established. Object points networks was designed steeply to the tunnel main axis as 3 cross section. Each cross section consisted of 3 point left, 2 point right and 1 point at the flowing line. Initial conditional measurement was made before tunnel excavation. Then the deformation measurement was made 5 period (1 period measured after tunnel excavate). All data sets were adjusted according to free adjustment method. The results from the investigation considering the tunnel line, a symmetrical subsidence was observed. The following day of tunnel excavation, we were observed %68 per of the total deformation. At the end of the last period measurements, %99 per of the total deformation was detected. Keywords: Tunnel, Deformation, Subsidence, Excavation

  15. Use of 3D Printing for Custom Wind Tunnel Fabrication

    Science.gov (United States)

    Gagorik, Paul; Bates, Zachary; Issakhanian, Emin

    2016-11-01

    Small-scale wind tunnels for the most part are fairly simple to produce with standard building equipment. However, the intricate bell housing and inlet shape of an Eiffel type wind tunnel, as well as the transition from diffuser to fan in a rectangular tunnel can present design and construction obstacles. With the help of 3D printing, these shapes can be custom designed in CAD models and printed in the lab at very low cost. The undergraduate team at Loyola Marymount University has built a custom benchtop tunnel for gas turbine film cooling experiments. 3D printing is combined with conventional construction methods to build the tunnel. 3D printing is also used to build the custom tunnel floor and interchangeable experimental pieces for various experimental shapes. This simple and low-cost tunnel is a custom solution for specific engineering experiments for gas turbine technology research.

  16. Tunneling Time in Ultrafast Science is Real and Probabilistic

    CERN Document Server

    Landsman, Alexandra; Maurer, Jochen; Boge, Robert; Ludwig, André; Heuser, Sebastian; Cirelli, Claudio; Gallmann, Lukas; Keller, Ursula

    2013-01-01

    We compare the main competing theories of tunneling time against experimental measurements using the attoclock in strong laser field ionization of helium atoms. Refined attoclock measurements reveal a real and not instantaneous tunneling delay time over a large intensity regime, using two different experimental apparatus. Only two of the theoretical predictions are compatible within our experimental error: the Larmor time, and the probability distribution of tunneling times constructed using a Feynman Path Integral (FPI) formulation. The latter better matches the observed qualitative change in tunneling time over a wide intensity range, and predicts a broad tunneling time distribution with a long tail. The implication of such a probability distribution of tunneling times, as opposed to a distinct tunneling time, challenges how valence electron dynamics are currently reconstructed in attosecond science. It means that one must account for a significant uncertainty as to when the hole dynamics begin to evolve.

  17. Inelastic scanning tunneling microscopy in conventional and unconventional superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Hlobil, Patrik; Schmalian, Joerg; Wulfhekel, Wulf; Jandke, Jasmin [Karlsruhe Institute of Technologie (Germany)

    2015-07-01

    Electron tunneling spectroscopy has been used extremely successful in order to verify the microscopic phonon pairing mechanism in conventional BCS superconductors using the Eliashberg theory. Nevertheless, earlier theories and experiments focused mainly on elastic tunneling processes. We present, motivated by recent experiments, a theoretical description of inelastic tunneling in STM in which an electrons tunnels from the tip into a BCS superconductor and coherently excites a phonon during the tunneling process. This additional channel enhances the measured conductivity and we show that if the superconductor is in the normal state, within some limitations, the derivative dσ/dV will be proportional to the Eliashberg function α2F. Additionally, the influence of the inelastic contributions on the tunneling spectrum in the superconducting state will be discussed. Finally, we generalize the theory to other bosonic excitations and focus on the question if inelastic tunneling could be used to unveil the electronic pairing mechanism in the iron pnictides.

  18. Videogrammetric Model Deformation Measurement Technique for Wind Tunnel Applications

    Science.gov (United States)

    Barrows, Danny A.

    2006-01-01

    Videogrammetric measurement technique developments at NASA Langley were driven largely by the need to quantify model deformation at the National Transonic Facility (NTF). This paper summarizes recent wind tunnel applications and issues at the NTF and other NASA Langley facilities including the Transonic Dynamics Tunnel, 31-Inch Mach 10 Tunnel, 8-Ft high Temperature Tunnel, and the 20-Ft Vertical Spin Tunnel. In addition, several adaptations of wind tunnel techniques to non-wind tunnel applications are summarized. These applications include wing deformation measurements on vehicles in flight, determining aerodynamic loads based on optical elastic deformation measurements, measurements on ultra-lightweight and inflatable space structures, and the use of an object-to-image plane scaling technique to support NASA s Space Exploration program.

  19. Superpoissonian shot noise in organic magnetic tunnel junctions

    Energy Technology Data Exchange (ETDEWEB)

    Cascales, Juan Pedro; Martinez, Isidoro; Aliev, Farkhad G., E-mail: farkhad.aliev@uam.es [Dpto. Fisica Materia Condensada C3, Instituto Nicolas Cabrera (INC), Condensed Matter Physics Institute (IFIMAC), Universidad Autonoma de Madrid, Madrid 28049 (Spain); Hong, Jhen-Yong; Lin, Minn-Tsong, E-mail: mtlin@phys.ntu.edu.tw [Department of Physics, National Taiwan University, Taipei 10617, Taiwan and Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan (China); Szczepański, Tomasz; Dugaev, Vitalii K. [Department of Physics, Rzeszów University of Technology, al. Powstańców Warszawy 6, 35-959 Rzeszów (Poland); Barnaś, Józef [Faculty of Physics, Adam Mickiewicz University, ul. Umultowska 85, 61-614 Poznań, Poland and Institute of Molecular Physics, Polish Academy of Sciences, ul. Smoluchowskiego 17, 60-179 Poznań (Poland)

    2014-12-08

    Organic molecules have recently revolutionized ways to create new spintronic devices. Despite intense studies, the statistics of tunneling electrons through organic barriers remains unclear. Here, we investigate conductance and shot noise in magnetic tunnel junctions with 3,4,9,10-perylene-teracarboxylic dianhydride (PTCDA) barriers a few nm thick. For junctions in the electron tunneling regime, with magnetoresistance ratios between 10% and 40%, we observe superpoissonian shot noise. The Fano factor exceeds in 1.5–2 times the maximum values reported for magnetic tunnel junctions with inorganic barriers, indicating spin dependent bunching in tunneling. We explain our main findings in terms of a model which includes tunneling through a two level (or multilevel) system, originated from interfacial bonds of the PTCDA molecules. Our results suggest that interfaces play an important role in the control of shot noise when electrons tunnel through organic barriers.

  20. Scanning tunneling microscope assembly, reactor, and system

    Science.gov (United States)

    Tao, Feng; Salmeron, Miquel; Somorjai, Gabor A

    2014-11-18

    An embodiment of a scanning tunneling microscope (STM) reactor includes a pressure vessel, an STM assembly, and three spring coupling objects. The pressure vessel includes a sealable port, an interior, and an exterior. An embodiment of an STM system includes a vacuum chamber, an STM reactor, and three springs. The three springs couple the STM reactor to the vacuum chamber and are operable to suspend the scanning tunneling microscope reactor within the interior of the vacuum chamber during operation of the STM reactor. An embodiment of an STM assembly includes a coarse displacement arrangement, a piezoelectric fine displacement scanning tube coupled to the coarse displacement arrangement, and a receiver. The piezoelectric fine displacement scanning tube is coupled to the coarse displacement arrangement. The receiver is coupled to the piezoelectric scanning tube and is operable to receive a tip holder, and the tip holder is operable to receive a tip.

  1. Subclinical carpal tunnel syndrome in acromegaly.

    Science.gov (United States)

    Kameyama, S; Tanaka, R; Hasegawa, A; Tamura, T; Kuroki, M

    1993-08-01

    Median nerve conduction was studied in 16 acromegalic patients with asymptomatic carpal tunnel syndrome (CTS) to examine the incidence of subclinical CTS. Thirteen patients (81%) and 23 hands (72%) demonstrated subclinical CTS, 10 bilaterally and three unilaterally in the dominant hand. The incidence reflects the greater sensitivity of the inching method for detecting focal conduction abnormalities. Two of three patients without subclinical CTS showed normal plasma somatomedin-C concentration despite growth hormone hypersecretion. Following adenomectomy, nerve conduction normalized in only six hands (26%). The postoperative persistence of the conduction delay implies that irreversible narrowing of the carpal tunnel rather than reversible soft tissue edema is the principal cause of CTS associated with acromegaly.

  2. Construction of tunnel Bôrik

    Directory of Open Access Journals (Sweden)

    Jozef Čížik

    2009-09-01

    Full Text Available When tunneling engineers talk on NATM, they often mean different things because some of them define it as a special technique,but others as a sort of philosophy. Recently the scene has been complicated by new terms and even alternative names, when discussingcertain aspects of NATM.The NATM integrates the principles of the behaviour of rock masses under load and monitoring the performance of undergroundconstruction during construction. The NATM is not a set of specific excavation and support techniques. Based on the computationof the optimal cross section, just a thin shotcrete protection is necessary. Additionally, geotechnical instruments are installed to measurethe later deformation of excavation. Therefore a monitoring of the stress distribution within the rock is possible. This monitoring makesthe method very flexible, even at surprising changes of the geomechanical rock consistency during the tunneling work.

  3. Multiorbital tunneling ionization of the CO molecule

    CERN Document Server

    Wu, J; Kunitski, M; Meckel, M; Voss, S; Sann, H; Kim, H; Jahnke, T; Czasch, A; Dörner, R

    2012-01-01

    We coincidently measure the molecular frame photoelectron angular distribution and the ion sum-momentum distribution of single and double ionization of CO molecules by using circularly and elliptically polarized femtosecond laser pulses, respectively. The orientation dependent ionization rates for various kinetic energy releases allow us to individually identify the ionizations of multiple orbitals, ranging from the highest occupied to the next two lower-lying molecular orbitals for various channels observed in our experiments. Not only the emission of a single electron, but also the sequential tunneling dynamics of two electrons from multiple orbitals are traced step by step. Our results confirm that the shape of the ionizing orbitals determine the strong laser field tunneling ionization in the CO molecule, whereas the linear Stark effect plays a minor role.

  4. Fully magnetic manganite spin filter tunnel junctions

    Science.gov (United States)

    Prasad, Bhagwati; Blamire, Mark G.

    2016-09-01

    In this paper we demonstrate spintronic devices which combine magnetic tunnel junctions with a spin-filtering tunnel barrier. These consist of an ultrathin ferromagnetic insulating barrier, Sm0.75Sr0.25MnO3, sandwiched between two ferromagnetic half-metallic manganite electrodes, La0.7Sr0.3MnO3 and La0.7Ca0.3MnO3, in a nanopillar structure. Depending on the relative magnetic configurations of barrier and electrode layers, three resistance states are well defined, which therefore represent a potential three-state memory concept. These results open the way for the development of spintronic devices by exploiting the many degrees of freedom of perovskite manganite heterostructure systems.

  5. Gravitinos Tunneling From Traversable Lorentzian Wormholes

    CERN Document Server

    Sakalli, I

    2015-01-01

    Recent research shows that Hawking radiation (HR) is also possible around the trapping horizon of a wormhole. In this article, we show that the HR of gravitino (spin-$3/2$) particles from the traversable Lorentzian wormholes (TLWH) reveals a negative Hawking temperature (HT). We first introduce the TLWH in the past outer trapping horizon geometry (POTHG). Next, we derive the Rarita-Schwinger equations (RSEs) for that geometry. Then, using both the Hamilton-Jacobi (HJ) ans\\"{a}tz and the WKB approximation in the quantum tunneling method, we obtain the probabilities of the emission/absorption modes. Finally, we derive the tunneling rate of the emitted gravitino particles, and succeed to read the HT of the TLWH.

  6. Seismic Response of Submerged Floating Tunnel Tether

    Institute of Scientific and Technical Information of China (English)

    SU Zhi-bin; SUN Sheng-nan

    2013-01-01

    A mathematical equation for vibration of submerged floating tunnel tether under the effects of earthquake and parametric excitation is presented.Multi-step Galerkin method is used to simplify this equation and the fourth-order Runge-Kuta integration method is used for numerical analysis.Finally,vibration response of submerged floating tunnel tether subjected to earthquake and parametric excitation is analyzed in a few numerical examples.The results show that the vibration response of tether varies with the seismic wave type; the steady maximum mid-span displacement of tether subjected to seismic wave keeps constant when parametric resonance takes place; the transient maximum mid-span displacement of tether is related to the peak value of input seismic wave acceleration.

  7. Structural and tunneling properties of Si nanowires

    KAUST Repository

    Montes Muñoz, Enrique

    2013-12-06

    We investigate the electronic structure and electron transport properties of Si nanowires attached to Au electrodes from first principles using density functional theory and the nonequilibrium Green\\'s function method. We systematically study the dependence of the transport properties on the diameter of the nanowires, on the growth direction, and on the length. At the equilibrium Au-nanowire distance we find strong electronic coupling between the electrodes and nanowires, which results in a low contact resistance. With increasing nanowire length we study the transition from metallic to tunneling conductance for small applied bias. For the tunneling regime we investigate the decay of the conductance with the nanowire length and rationalize the results using the complex band structure of the pristine nanowires. The conductance is found to depend strongly on the growth direction, with nanowires grown along the ⟨110⟩ direction showing the smallest decay with length and the largest conductance and current.

  8. Interpreting Attoclock Measurements of Tunnelling Times

    CERN Document Server

    Torlina, Lisa; Kaushal, Jivesh; Muller, Harm Geert; Ivanov, Igor; Kheifets, Anatoli; Zielinski, Alejandro; Scrinzi, Armin; Ivanov, Misha; Smirnova, Olga

    2014-01-01

    We discuss measurements of time-delays during strong-field ionization of atoms using few-cycle circularly polarized laser pulses -- the attoclock setup. We perform numerical experiments for the benchmark system of the hydrogen atom and analyze them using fully quantum analytical theory with no ad-hoc assumptions or adjustable parameters. Excellent quantitative agreement between theory and ab initio simulations allows us to characterize time-delays measured by the attoclock, demonstrate that these delays are not related to tunnelling delays and are induced entirely by the interaction of the liberated electron with the long-range Coulomb potential of the ionic core. Our analysis gives access to 'ionization times' -- the times when an electron exits the tunnelling barrier created by the combination of the laser field and the core potential, showing that some of the key assumptions used in the semiclassical interpretation of the attoclock experiments do not always agree with the fully quantum analysis.

  9. Tunnel backfill erosion by dilute water

    Energy Technology Data Exchange (ETDEWEB)

    Olin, M. [VTT Technical Research Centre of Finland, Espoo (Finland)

    2014-03-15

    The goal was to estimate smectite release from tunnel backfill due to dilute groundwater pulse during post glacial conditions. The plan was to apply VTT's two different implementations (BESW{sub D} and BESW{sub S}) of well-known model of Neretnieks et al. (2009). It appeared difficult to produce repeatable results using this model in COMSOL 4.2 environment, therefore a semi-analytical approximate approach was applied, which enabled to take into account both different geometry and smectite content in tunnel backfill as compared to buffer case. The results are quite similar to buffer results due to the decreasing effect of smaller smectite content and the increasing effect of larger radius. (orig.)

  10. Tunnelling matrix elements with Gutzwiller wave functions

    Energy Technology Data Exchange (ETDEWEB)

    Di Ciolo, Andrea; Tocchio, Luca F.; Gros, Claudius [Institut fuer Theoretische Physik, Goethe Universitaet Frankfurt, Frankfurt Am Main (Germany)

    2011-07-01

    We use a generalized Gutzwiller approach, in order to study projected particle (hole) excitations for superconducting systems and systems with antiferromagnetic (AFM) order. As in the standard Gutzwiller scheme the effects of the strong electronic correlations are given via the suppression of the site double occupancy; for our computations it is helpful to consider a lattice with a reservoir site unaffected by this suppression of the double occupancy. In this approach we obtain the probabilities for the tunnelling of a particle (hole) into the projected state. Our results are due only to the physical properties of the trial state and not to the choice of a specifical Hamiltonian: in this sense, they are model-independent but not universal, because they rely on the features of the chosen Gutzwiller wave function (projected Fermi Sea, BCS superconductor, AFM..) The accuracy and the reliability of our analytical approximation is tested using the Variational Monte Carlo. Possible comparisons with tunnelling experiments are discussed.

  11. Control of Smoke Flow in a Tunnel

    Directory of Open Access Journals (Sweden)

    K Brahim

    2013-01-01

    Full Text Available This study focuses on fires in road tunnels in order to increase the level of security for users. This paper proposed numerical investigations carried out on a small scale tunnel model to study the fire-induced smoke control by longitudinal and longitudinal-natural ventilation systems. We studied the effect of two ventilation systems on the temperature distribution and stratification of the pollutant to estimate the effectiveness of ventilation systems. The flow is characterized by the temperature fields, temperature profiles and the Froude number. The numerical tool used is FDS (version 4.0. This numerical study requires validation with experiment and numerical results and comparison with the model developed by Kunsch J.P. to evaluate the critical velocity. However, good agreement with experimental results, it confirms the possibility of using this code in the problem.

  12. Small Numbers From Tunneling Between Brane Throats

    Energy Technology Data Exchange (ETDEWEB)

    Kachru, Shamit

    2001-07-25

    Generic classes of string compactifications include ''brane throats'' emanating from the compact dimensions and separated by effective potential barriers raised by the background gravitational fields. The interaction of observers inside different throats occurs via tunneling and is consequently weak. This provides a new mechanism for generating small numbers in Nature. We apply it to the hierarchy problem, where supersymmetry breaking near the unification scale causes TeV sparticle masses inside the standard model throat. We also design naturally long-lived cold dark matter which decays within a Hubble time to the approximate conformal matter of a long throat. This may soften structure formation at galactic scales and raises the possibility that much of the dark matter of the universe is conformal matter. Finally, the tunneling rate shows that the coupling between throats, mediated by bulk modes, is stronger than a naive application of holography suggests.

  13. View of the LHC tunnel with worker.

    CERN Document Server

    Maximilien Brice

    2006-01-01

    The 616th dipole out of 1232, on its way to its final position in the tunnel of the LHC. Technicians and engineers continue to work day and night carefully installing 20 magnets a week. Each of the dipoles weighs 34 tonnes and is 15 m long. Once they have been lowered down the specially constructed shaft on the Meyrin site, they begin a slow progression to their final destinations in the LHC tunnel, taking about 10 hours to arrive at Point 6, the furthest point on the LHC ring. Upon arrival, each of the dipoles is aligned and interconnected to the magnets that are already installed.Bigger files available (39Mpx)

  14. Alternative diagnostic technique for carpal tunnel syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Hayakawa, Katsuhiko; Nakane, Takashi [Aiko Orthopaedic Hospital, Nagoya (Japan); Kobayashi, Shigeru; Shibata, Kunio [Fujita Health Univ., Toyoake, Aichi (Japan). School of Medicine

    2002-10-01

    Compressive and entrapment neuropathies are common clinical syndromes characterized by neurologic deficits due to mechanical or dynamic compression of peripheral nerves. However, the definitive diagnosis based on clinical symptoms alone is difficult in many cases, and the electrophysiological diagnostic method is solely used as a supplementary diagnostic method at present. As a new diagnostic method for entrapment neuropathy, the present study investigated the usefulness of gadolinium-enhanced MRI in carpal tunnel syndrome. On enhanced MRI of idiopathic carpal tunnel syndrome, contrast-enhancement in the median nerve was found in 30 of 34 hands (88.2%). Enhanced MRI allows to visualize intraneural edema in the nerve easily on the naked eye. Therefore, this technique supplied useful information for making definitive diagnosis and is promising as a non-invasive diagnostic method for entrapment neuropathy. (author)

  15. Wind tunnel measurements of windscreen performance

    Science.gov (United States)

    Maniet, Edward R.

    2002-05-01

    Microphone windscreens are routinely used in outdoor acoustic measurements to reduce wind noise pickup. Characterization of windscreen performance outdoors with real wind has several drawbacks notably that the test conditions cannot be controlled. Test methodology has been developed that provides controlled, repeatable measurements of microphone windscreen performance in a laboratory setting. Wind noise measurements are performed using a high-speed/laminar-flow, low-noise wind tunnel that incorporates a large anechoic chamber. The wind tunnel is modified to produce a turbulent flow into which the microphone and windscreen under evaluation are placed. The turbulent velocity spectrum is measured using multi-axis hot-wire anemometers and compared to outdoor data to locate the best position in the turbulent flow to place the test article. Comparative performance measurements of several windscreen designs are presented.

  16. Tunneling of trapped-atom Bose condensates

    Indian Academy of Sciences (India)

    Subodh R Shenoy

    2002-02-01

    We obtain the dynamics in number and phase difference, for Bose condensates that tunnel between two wells of a double-well atomic trap, using the (nonlinear) Gross–Pitaevskii equation. The dynamical equations are of the canonical form for the two conjugate variables, and the Hamiltonian corresponds to that of a momentum-shortened pendulum, supporting a richer set of tunneling oscillation modes than for a superconductor Josephson junction, that has a fixed-length pendulum as a mechanical model. Novel modes include ‘inverted pendulum’ oscillations with an average angle of ; and oscillations about a self-maintained population imbalance that we term ‘macroscopic quantum self-trapping’. Other systems with this phase-number nonlinear dynamics include two-component (interconverting) condensates in a single harmonic trap, and He3B superfluids in two containers connected by micropores.

  17. Fire safety case study of a railway tunnel: Smoke evacuation

    Directory of Open Access Journals (Sweden)

    van Maele Karim

    2007-01-01

    Full Text Available When a fire occurs in a tunnel, it is of great importance to assure the safety of the occupants of the tunnel. This is achieved by creating smoke-free spaces in the tunnel through control of the smoke gases. In this paper, results are presented of a study concerning the fire safety in a real scale railway tunnel test case. Numerical simulations are performed in order to examine the possibility of natural ventilation of smoke in inclined tunnels. Several aspects are taken into account: the length of the simulated tunnel section, the slope of the tunnel and the possible effects of external wind at one portal of the tunnel. The Fire Dynamics Simulator of the National Institute of Standards and Technology, USA, is applied to perform the simulations. The simulations show that for the local behavior of the smoke during the early stages of the fire, the slope of the tunnel is of little importance. Secondly, the results show that external wind and/or pressure conditions have a large effect on the smoke gases inside the tunnel. Finally, some idea for the value of the critical ventilation velocity is given. The study also shows that computational fluid dynamics calculations are a valuable tool for large scale, real life complex fire cases. .

  18. Tunnels: different construction methods and its use for pipelines installation

    Energy Technology Data Exchange (ETDEWEB)

    Mattos, Tales; Soares, Ana Cecilia; Assis, Slow de; Bolsonaro, Ralfo; Sanandres, Simon [Petroleo do Brasil S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil)

    2009-07-01

    In a continental dimensions country like Brazil, the pipeline modal faces the challenge of opening ROW's in the most different kind of soils with the most different geomorphology. To safely fulfill the pipeline construction demand, the ROW opening uses all techniques in earthworks and route definition and, where is necessary, no digging techniques like horizontal directional drilling, micro tunneling and also full size tunnels design for pipelines installation in high topography terrains to avoid geotechnical risks. PETROBRAS has already used the tunnel technique to cross higher terrains with great construction difficult, and mainly to make it pipeline maintenance and operation easier. For the GASBOL Project, in Aparados da Serra region and in GASYRG, in Bolivia, two tunnels were opened with approximately 700 meters and 2,000 meters each one. The GASBOL Project had the particularity of being a gallery with only one excavation face, finishing under the hill and from this point was drilled a vertical shaft was drilled until the top to install the pipeline section, while in GASYRG Project the tunnel had two excavation faces. Currently, two projects are under development with tunnels, one of then is the Caraguatatuba-Taubate gas pipeline (GASTAU), with a 5 km tunnel, with the same concepts of the GASBOL tunnel, with a gallery to be opened with the use of a TBM (Tunneling Boring Machine), and a shaft to the surface, and the gas pipeline Cabiunas-Reduc III (GASDUC III) project is under construction with a 3.7 km tunnel, like the GASYRG tunnel with two faces. This paper presents the main excavation tunneling methods, conventional and mechanized, presenting the most relevant characteristics from both and, in particular, the use of tunnels for pipelines installation. (author)

  19. Tunnel magnetoresistance in magnetic tunnel junctions with ZnS barrier

    Energy Technology Data Exchange (ETDEWEB)

    Guth, M.; Da Costa, V.; Schmerber, G.; Dinia, A.; van den Berg, H. A. M.

    2001-06-01

    A first experimental evidence of a significant tunneling magnetoresistance signal of about 5% at 300 K for a magnetic tunnel junction consisting of hard and soft magnetic layers separated by a 2 nm ZnS semiconducting barrier is reported. The samples have been grown by sputtering on Si(111) substrate at room temperature and have the following structure: Fe{sub 6nm}Cu{sub 30nm}CoFe{sub 1.8nm}Ru{sub 0.8nm}CoFe{sub 3nm}ZnS{sub x}CoFe{sub 1nm}Fe{sub 4nm}Cu{sub 10nm}Ru{sub 3nm}. The hard magnetic bottom electrode consists of the artificial antiferromagnetic structure in which the rigidity is ensured by the antiferromagnetic exchange coupling between two FeCo layers through a Ru spacer layer. Barrier impedance scanning microscope (BISM) measurements reveal a good homogeneity of the barrier thickness. Electric transport measurements over square tunnel elements with lateral sizes between 3 and 100 {mu}m, exhibit a typical tunnel current{endash}voltage variations and tunnel resistance of 2{endash}3 k{Omega}{mu}m2 with small variations which never exceed a factor of 2, which is in good agreement with the BISM results. This good reproducibility of the junctions is very promising for MRAMs and transistors applications. {copyright} 2001 American Institute of Physics.

  20. Observing Quantum Tunneling in Perturbation Series

    CERN Document Server

    Suzuki, H; Suzuki, Hiroshi; Yasuta, Hirofumi

    1997-01-01

    It is well-known that the quantum tunneling makes conventional perturbation series non-Borel summable. We use this fact reversely and attempt to extract the decay width of the false-vacuum from the actual perturbation series of the vacuum energy density (vacuum bubble diagrams). It is confirmed that, at least in quantum mechanical examples, our proposal provides a complimentary approach to the the conventional instanton calculus in the strong coupling region.

  1. The Femarnbelt Tunnel: Regional Development Perspectives

    DEFF Research Database (Denmark)

    Matthiessen, Christian Wichmann; Lundhus, Peter

    2011-01-01

    The Fehmarnbelt Link between Denmark and Germany, for which in September 2008 a bilateral government treaty was signed, is the last of the three links uniting transportation networks in Northern Europe. The three links (the Great Belt and the Øresund Link being the other two) are impressive mega...... it was decided that an immersed tunnel should form the basis for the continuous planning of the project, including the environmental impact studies. Completion of the link is scheduled for 2020...

  2. Seebeck Effect in Magnetic Tunnel Junctions

    OpenAIRE

    Walter, Marvin; Walowski, Jakob; Zbarsky, Vladyslav; Münzenberg, Markus; Schäfers, Markus; Ebke, Daniel; Reiss, Günter; Thomas, Andy; Peretzki, Patrick; Seibt, Michael; Moodera, Jagadeesh S.; Czerner, Michael; Bachmann, Michael; Heiliger, Christian

    2011-01-01

    Creating temperature gradients in magnetic nanostructures has resulted in a new research direction, i.e., the combination of magneto- and thermoelectric effects. Here, we demonstrate the observation of one important effect of this class: the magneto-Seebeck effect. It is observed when a magnetic configuration changes the charge based Seebeck coefficient. In particular, the Seebeck coefficient changes during the transition from a parallel to an antiparallel magnetic configuration in a tunnel j...

  3. Aeronautical Wind Tunnels, Europe and Asia

    Science.gov (United States)

    2006-02-01

    closed-circuit wind tunnel, 8-kW motor. Operates at sub-freezing temperatures. Built of wood and epoxy-fiberglass composite. Internally insulated with...airplane models. Also used to test wind loads on buildings, bridges, radar antennas, and television towers, and aerodynamic performance of windmills ...flow. This facility has a mahogany six- bladed fan powered by a 2000-hp, 750-V DC motor. At full speed this facility can run at 1.5 MVA. Data

  4. Python Engine Installed in Altitude Wind Tunnel

    Science.gov (United States)

    1949-01-01

    An engine mechanic checks instrumentation prior to an investigation of engine operating characteristics and thrust control of a large turboprop engine with counter-rotating propellers under high-altitude flight conditions in the 20-foot-dianieter test section of the Altitude Wind Tunnel at the Lewis Flight Propulsion Laboratory of the National Advisory Committee for Aeronautics, Cleveland, Ohio, now known as the John H. Glenn Research Center at Lewis Field.

  5. Tunneling of electrons through semiconductor superlattices

    Indian Academy of Sciences (India)

    C L Roy

    2002-11-01

    The purpose of the present paper is to report a study of tunneling of electrons through semiconductor superlattices (SSL); specially, we have analysed diverse features of transmission coefficient of SSL. The SSL we have considered is Ga0.7Al0.3As–GaAs which has been drawing considerable attention during the recent past on account of some typical features of its band structure. We have indicated how our results would help fabrication of ultra high speed devices.

  6. Trophic ulcers in the carpal tunnel syndrome

    Directory of Open Access Journals (Sweden)

    Abelardo Q.-C. Araújo

    1993-09-01

    Full Text Available A patient with carpal tunnel syndrome (CTS and trophic ulcers is described. Despite the healing of the ulcers after surgery for CTS, the severe sensory deficit and the electrophysiological tests have not shown any significant improvement. We think these findings argue against the hypothesis of the sensory deficit being responsible for the trophic ulcers. We favor a major role for the sympathetic disturbances as the main cause for those lesions.

  7. Phase control of resonant tunneling in nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Kaminski, Jerzy Z.; Saczuk, Ewa; Velez, Felipe Cajiao [Institute of Theoretical Physics, Faculty of Physics, University of Warsaw, Hoza, 69, 00-681, Warszawa (Poland)

    2013-02-15

    Resonant tunneling of electrons through a multiple potential barrier in a semiconductor heterostructure in the presence of both an oscillating in time and constant external electric fields is considered. In order to solve the problem numerically the concept of the scattering matrix is developed and a stable numerical algorithm is presented. Using this algorithm computations for different amplitudes and different spatial configurations of the fields are performed. (copyright 2012 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Brownian refrigeration by hybrid tunnel junctions

    OpenAIRE

    Peltonen, J. T.; Helle, M.; Timofeev, A. V.; Solinas, P.; Hekking, F. W. J.; Pekola, Jukka P.

    2011-01-01

    Voltage fluctuations generated in a hot resistor can cause extraction of heat from a colder normal metal electrode of a hybrid tunnel junction between a normal metal and a superconductor. We extend the analysis presented in Phys. Rev. Lett. 98, 210604 (2007) of this heat rectifying system, bearing resemblance to a Maxwell’s demon. Explicit analytic calculations show that the entropy of the total system is always increasing. We then consider a single-electron transistor configuration with two ...

  9. O(3)-invariant tunneling in general relativity

    Energy Technology Data Exchange (ETDEWEB)

    Berezin, V.A.; Tkachev, I.I.; Kuzmin, V.A.

    1988-06-30

    We derived a general formula for the action for any O(3)-invariant tunneling processes in false vacuum decay in general relativity. The general classification of the bubble euclidean trajectories is elaborated and explicit expressions for bounces for some processes like the vacuum creation of a double bubble in particular in the vicinity of a black hole, the subbarrier creation of the Einstein-Rosen bridge, creation from nothing of two Minkowski worlds connected by a shell, etc., are given.

  10. Interfacial capacitance effects in magnetic tunneling junctions

    CERN Document Server

    Landry, G; Du, J; Xiao, J Q

    2001-01-01

    We have investigated the AC transport properties of magnetic tunnel junctions (MTJ) in order to characterize interfacial properties. One such property is interfacial charge accumulation, which leads to a voltage drop in the electrodes of the MTJ and the measured capacitance differing from the geometrical capacitance. Through measurement of capacitance spectra, we have extracted an interfacial capacitance of 16 mu F/cm sup 2 per interface and a screening length of 0.55 A for FeNi electrodes.

  11. Sulphate reduction in the Aespoe HRL tunnel

    Energy Technology Data Exchange (ETDEWEB)

    Gustafson, G. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Geology; Laaksoharju, M. [ed.; Skaarman, C. [GeoPoint AB, Sollentuna (Sweden); Pedersen, K. [Goeteborg Univ. (Sweden). Dept. of Genetics, Microbiology and Molecular Biology; Rhen, I. [VBB Viak (Sweden); Tullborg, E.L. [Terralogica AB (Sweden); Wallin, B. [Geokema AB (Sweden); Wikberg, P. [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    1995-12-01

    Evidence and indications of sulphate reduction based on geological, hydrogeological, groundwater, isotope and microbial data gathered in and around the Aespoe Hard Rock Laboratory tunnel have been evaluated. This integrated investigation showed that sulphate reduction had taken place in the past but is most likely also an ongoing process. Anaerobic sulphate-reducing bacteria can live in marine sediments, in the tunnel sections under the sea and in deep groundwaters, since there is no access to oxygen. The sulphate-reducing bacteria seem to thrive when the Cl{sup -} concentration of the groundwater is 4000-6000 mg/l. Sulphate reduction is an in situ process but the resulting hydrogen-sulphide rich water can be transported to other locations. A more vigorous sulphate reduction takes place when the organic content in the groundwater is high (>10 mg/l DOC) which is the case in the sediments and in the groundwaters under the sea. Some bacteria use hydrogen as an electron donor instead of organic carbon and can therefore live in deep environments where access to organic material is limited. The sulphate-reducing bacteria seem to adapt to changing flow situations caused by the tunnel construction relatively fast. Sulphate reduction seems to have occurred and will probably occur where conditions are favourable for the sulphate-reducing bacteria such as anaerobic brackish groundwater with dissolved sulphate and organic carbon or hydrogen. 59 refs, 37 figs, 6 tabs.

  12. Sensitivity of resonant tunneling diode photodetectors

    Science.gov (United States)

    Pfenning, Andreas; Hartmann, Fabian; Langer, Fabian; Kamp, Martin; Höfling, Sven; Worschech, Lukas

    2016-09-01

    We have studied the sensitivity of AlGaAs/GaAs double barrier resonant tunneling diode photodetectors with an integrated GaInNAs absorption layer for light sensing at the telecommunication wavelength of λ = 1.3 μm for illumination powers from pico- to microwatts. The sensitivity decreases nonlinearly with power. An illumination power increase of seven orders of magnitude leads to a reduction of the photocurrent sensitivity from S I = 5.82 × 103 A W-1 to 3.2 A W-1. We attribute the nonlinear sensitivity-power dependence to an altered local electrostatic potential due to hole-accumulation that on the one hand tunes the tunneling current, but on the other hand affects the lifetime of photogenerated holes. In particular, the lifetime decreases exponentially with increasing hole population. The lifetime reduction results from an enhanced electrical field, a rise of the quasi-Fermi level, and an increased energy splitting within the triangular potential well. The non-constant sensitivity is a direct result of the non-constant lifetime. Based on these findings, we provide an expression that allows us to calculate the sensitivity as a function of illumination power and bias voltage, show a way to model the time-resolved photocurrent, and determine the critical power up to which the resonant tunneling diode photodetector sensitivity can be assumed constant.

  13. Charge Transport in Resonant Tunneling Double - Diodes

    Science.gov (United States)

    Diff, Karim

    With the advent of semiconductor devices with typical lengths of the order of a few nanometers and response times of a few picoseconds, the conventional methods used in device modeling have reached their limits of validity. Modern devices based on heterostructures fabricated by Molecular Beam Epitaxy (MBE) require more fundamental approaches based entirely on quantum mechanics. These generally necessitate numerical solutions and are computationally intensive. This dissertation focuses on Resonant Tunneling Double-Barrier (RTDB) diodes as the prototype of "quantum devices". A one-electron model and the effective mass approximation are used. By solving numerically the time-dependent Schrodinger equation for Gaussian wavepackets, the various time characteristics of resonant tunneling are probed. These characteristics are usually overlooked in other treatments based on the time-independent Schrodinger equation. The transit time, the build-up time and the exponential decay time are studied. The difference between these various time scales and their relative importance are discussed. A new method that takes into account the finite extent of the electron wavefunction, is proposed to compute the I-V characteristics of such devices. Results indicate a possible explanation for the discrepancy observed between experimental results and previous analyses. The effect of high frequency fields on resonant tunneling is also studied, and a method to determine the intrinsic cut-off frequency is suggested. The role of the effective mass in the determination of the characteristics of RTDB diodes is emphasized throughout this work.

  14. Sulphate reduction in the Aespoe HRL tunnel

    Energy Technology Data Exchange (ETDEWEB)

    Gustafson, G. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Geology; Laaksoharju, M. [ed.; Skaarman, C. [GeoPoint AB, Sollentuna (Sweden); Pedersen, K. [Goeteborg Univ. (Sweden). Dept. of Genetics, Microbiology and Molecular Biology; Rhen, I. [VBB Viak (Sweden); Tullborg, E.L. [Terralogica AB (Sweden); Wallin, B. [Geokema AB (Sweden); Wikberg, P. [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    1995-12-01

    Evidence and indications of sulphate reduction based on geological, hydrogeological, groundwater, isotope and microbial data gathered in and around the Aespoe Hard Rock Laboratory tunnel have been evaluated. This integrated investigation showed that sulphate reduction had taken place in the past but is most likely also an ongoing process. Anaerobic sulphate-reducing bacteria can live in marine sediments, in the tunnel sections under the sea and in deep groundwaters, since there is no access to oxygen. The sulphate-reducing bacteria seem to thrive when the Cl{sup -} concentration of the groundwater is 4000-6000 mg/l. Sulphate reduction is an in situ process but the resulting hydrogen-sulphide rich water can be transported to other locations. A more vigorous sulphate reduction takes place when the organic content in the groundwater is high (>10 mg/l DOC) which is the case in the sediments and in the groundwaters under the sea. Some bacteria use hydrogen as an electron donor instead of organic carbon and can therefore live in deep environments where access to organic material is limited. The sulphate-reducing bacteria seem to adapt to changing flow situations caused by the tunnel construction relatively fast. Sulphate reduction seems to have occurred and will probably occur where conditions are favourable for the sulphate-reducing bacteria such as anaerobic brackish groundwater with dissolved sulphate and organic carbon or hydrogen. 59 refs, 37 figs, 6 tabs.

  15. Tunneling ionization of vibrationally excited nitrogen molecules

    Science.gov (United States)

    Kornev, Aleksei S.; Zon, Boris A.

    2015-09-01

    Ionization of molecular nitrogen plays an important role in the process of light-filament formation in air. In the present paper we theoretically investigated tunneling ionization of the valence 3 σg and 1 πu shells in a N2 molecule using a strong near-infrared laser field. This research is based on our previously proposed theory of anti-Stokes-enhanced tunneling ionization with quantum accounting for the vibrationally excited states of the molecules [A. S. Kornev and B. A. Zon, Phys. Rev. A 86, 043401 (2012), 10.1103/PhysRevA.86.043401]. We demonstrated that if the N2 molecule is ionized from the ground vibrational state, then the contribution of the 1 πu orbital is 0.5%. In contrast, for vibrationally excited states with a certain angle between the light polarization vector and the molecule axis, both shells can compete and even reverse their contributions due to the anti-Stokes mechanism. The structure constants of molecular orbitals are extracted from numerical solutions to the Hartree-Fock equations. This approach correctly takes into account the exchange interaction. Quantum consideration of vibrational motion results in the occurrence of the critical vibrational state, the tunneling ionization from which has the maximum rate. The numbers of the critical vibrational states are different for different valence shells. In addition, quantum description of vibrations changes the rate of ionization from the ground vibrational state by 20%-40% in comparison with the quasiclassical results.

  16. Energy Optimization of Road Tunnel Lighting Systems

    Directory of Open Access Journals (Sweden)

    Ferdinando Salata

    2015-07-01

    Full Text Available A road tunnel is an enclosed and covered infrastructure for the vehicular traffic. Its lighting system provides 24 h of artificial sources only, with a higher amount of electric power used during the day. Due to safety reasons, when there is natural lighting outside the tunnel, the lighting levels in the stretches right after the entrance and before the exit must be high, in order to guide the driver’s eye towards the middle of the tunnel where the luminance must guarantee safe driving, avoid any over-dimensioning of the lighting systems, and produce energy savings. Such effects can be reached not only through the technological advances in the field of artificial lighting sources with high luminous efficiency, but also through new materials for road paving characterized by a higher reflection coefficient than other ordinary asphalts. This case study examines different technical scenarios, analyzing and comparing possible energy and economic savings. Traditional solutions are thus compared with scenarios suggesting the solutions previously mentioned. Special asphalts are interesting from an economic point of view, whereas the high costs of LED sources nowadays represent an obstacle for their implementation.

  17. Tunneling spectra of graphene on copper unraveled.

    Science.gov (United States)

    Zhang, Xin; Stradi, Daniele; Liu, Lei; Luo, Hong; Brandbyge, Mads; Gu, Gong

    2016-06-22

    Scanning tunneling spectroscopy is often employed to study two-dimensional (2D) materials on conductive growth substrates, in order to gain information on the electronic structures of the 2D material-substrate systems, which can lead to insight into 2D material-substrate interactions, growth mechanisms, etc. The interpretation of the spectra can be complicated, however. Specifically for graphene grown on copper, there have been conflicting reports of tunneling spectra. A clear understanding of the mechanisms behind the variability is desired. In this work, we have revealed that the root cause of the variability in tunneling spectra is the variation in graphene-substrate coupling under various experimental conditions, providing a salutary perspective on the important role of 2D material-substrate interactions. The conclusions are drawn from measured data and theoretical calculations for monolayer, AB-stacked bilayer, and twisted bilayer graphene coexisting on the same substrates in areas with and without intercalated oxygen, demonstrating a high degree of consistency. The Van Hove singularities of the twisted graphene unambiguously indicate the Dirac energy between them, lending strong evidence to our assignment of the spectral features. In addition, we have discovered an O-Cu superstructure that has never been observed before.

  18. An air cleaner for road tunnels

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    an air cleaner employing pulse induced plasma chemical process to remove dust and carbon monoxide (CO) in road tunnels is presented, which is composed of mainly a precipitator, a reactor, a flow control system, a power supply and a measurement system. Its performances are studied in simulated air conditions. It is found that the rate of dust removal is dependent on the voltage of the pulse power, the distance between the two dust collecting plates of the electrostatic precipitator,the effective length of the precipitator and the air flow rate in the precipitator, and that of CO removal is affected by the voltage and frequency of the super pulse power, the air flow rate in the reactor and the relative humidity of air. Applying such an cleaner of a proper design to the treatment of polluted air at a flow rate of 7 m/s can achieve the rate of dust removal up to 93 % and that of CO removal up to 72.6 %, which efficiently controls the concentrations of CO and dust under allowable limits. It is implied that the proposed air cleaner is a potential solution to air control in road tunnels, and is prominent for its performances and saving the huge cost of longitudinal ventilation tunnel or vertical vent and ventilation facilities.

  19. Gamma Radiation Tolerance of Magnetic Tunnel Junctions

    Science.gov (United States)

    Ren, Fanghui; Jander, Albrecht; Dhagat, Pallavi; Nordman, Cathy

    2011-10-01

    Determining the radiation tolerance of magnetic tunnel junctions (MTJ), which are the storage elements of non-volatile magnetoresistive random access memories (MRAM), is important for investigating their potential application in space. In this effort, the effect of gamma radiation on MTJs with MgO tunnel barriers was studied. Experimental and control groups of samples were characterized by ex situ measurements of the magnetoresistive hysteresis loops and I-V curves. The experimental group was exposed to gamma rays from a ^60Co source. The samples initially received a dose of 5.9 Mrad (Si) after which they were again characterized electrically and magnetically. Irradiation was then continued for a cumulative dose of 10 Mrad and the devices re-measured. The result shows no change in magnetic properties such as coercivity or exchange coupling due to irradiation. After correcting for differences in temperature at the time of testing, the tunneling magnetoresistance was also found to be unchanged. Thus, it has been determined that MgO-based MTJs are highly tolerant of gamma radiation, particularly in comparison to silicon field-effect transistors which have been shown to degrade with gamma ray exposure even as low as 100 Krad [Zhiyuan Hu. et al., IEEE trans. on Nucl. Sci., vol. 58, 2011].

  20. Chloride Transport in Undersea Concrete Tunnel

    Directory of Open Access Journals (Sweden)

    Yuanzhu Zhang

    2016-01-01

    Full Text Available Based on water penetration in unsaturated concrete of underwater tunnel, a diffusion-advection theoretical model of chloride in undersea concrete tunnel was proposed. The basic parameters including porosity, saturated hydraulic conductivity, chloride diffusion coefficient, initial water saturation, and moisture retention function of concrete specimens with two water-binder ratios were determined through lab-scale experiments. The variation of chloride concentration with pressuring time, location, solution concentration, initial saturation, hydraulic pressure, and water-binder ratio was investigated through chloride transport tests under external water pressure. In addition, the change and distribution of chloride concentration of isothermal horizontal flow were numerically analyzed using TOUGH2 software. The results show that chloride transport in unsaturated concrete under external water pressure is a combined effect of diffusion and advection instead of diffusion. Chloride concentration increased with increasing solution concentration for diffusion and increased with an increase in water pressure and a decrease in initial saturation for advection. The dominant driving force converted with time and saturation. When predicting the service life of undersea concrete tunnel, it is suggested that advection is taken into consideration; otherwise the durability tends to be unsafe.