Load-deflection characteristics of small bore insulated pipe clamps

International Nuclear Information System (INIS)

Severud, L.K.; Clark, G.L.

1982-01-01

High temperature LMFBR piping is subject to rapid temperature changes during transient events. Typically, this pipe is supported by specially designed insulated pipe clamps to prevent excessive thermal stress from developing during these transients. The special insulated clamps used on both FFTF and CRBR piping utilize a Belleville spring arrangement to compensate for pipe thermal expansion. Analysis indicates that this produces a non-linear, directionally sensitive clamp spring rate. Since these spring rates influence the seismic response of a supported piping system, it was deemed necessary to evaluate them further by test. This has been accomplished for the FFTF clamps. A more standard insulated pipe clamp, which does not incorporate Belleville springs to accommodate thermal expansion, was also tested. This type clamp is simple in design, and economically attractive. It may have wide application prospects for use in LMFBR small bore auxiliary piping operating at temperatures below 427 0 C. Load deflection tests were conducted on 2.54 CM and 7.62 CM diameter samples of these commercial clamps

Downhole dehydration - status report and implementation study; Downhole Dehydration - Statusbericht und Umsetzungsstudie

Energy Technology Data Exchange (ETDEWEB)

Jacobs, D.; Schmidt, D. [BEB Erdgas und Erdoel GmbH, Hannover (Germany)

1998-12-31

Downhole dehydration, i.e. in-situ separation of water and oil, is an interesting new technology. The contribution describes the technology and the results of a field experiment. (orig.) [Deutsch] Die Tail-End Foerderphase in der deutschen Erdoelproduktion, welche durch hohe Wasserhebekosten gekennzeichnet ist, erfordert zur Aufrechterhaltung der Wirtschaftlichkeit neue Gedankenansaetze. Ein aus wirtschaftlicher und technischer Sicht reizvoller Optimierungsgedanke ist die untertaegige Wasser/Oel Separation, auch Downhole Dehydration genannt. Unter Downhole Dehydration (DHD) versteht man also die untertaegige (teilweise) Separation des Lagerstaettenwassers vom Nassoel, kurz nachdem das Gemisch untertaegig in das Bohrloch eingetreten ist. Dabei wird das abgetrennte Lagerstaettenwasser untertage in einen geeigneten Horizont unmittelbar wieder injiziert und das Oel (wie bei der konventionellen Foerderung) zutage gepumpt, mit dem Ziel der Nutzung der daraus resultierenden Kosten- und Investitionsersparnis. Ziel dieses Vortrages ist es, einen kurzen Einblick in die erstmalig in Europa angewandte Technik zu geben und von den Erfahrungen des praktizierten Feldversuches zu berichten. (orig.)

Structural consideration for hot and cold pipe clamps in LMFBR applications

International Nuclear Information System (INIS)

Anderson, M.J.; Huang, S.N.; Kappauf, H.; Wagner, S.E.; Wirtz, K.H.

1983-01-01

A series of analytical studies are described which evaluate stress levels induced in a 600 mm high temperature, thin-wall sodium pipeline by two alternate clamp designs. The first design consists of a band mounted directly on the pipe and is called the hot clamp. The second design consists of a band mounted using insulation standoffs and is called the cold clamp. Pipe stress levels induced by transient thermal dead weight and seismic loads are discussed. Pipe stress levels and system dynamic spring rates are presented. Procedures utilized to combine clamp induced pipe stress with other short and long term pipe system stresses are detailed. Recommendations for practical application in LMFBR pipe systems are made

Structural considerations for hot and cold pipe clamps in LMFBR applications

International Nuclear Information System (INIS)

Anderson, M.J.; Huang, S.N.; Wagner, S.E.; Kappauf, H.; Wirtz, K.H.

1983-01-01

A series of analytical studies are described which evaluate stress levels induced in a 600 mm high temperature, thin-wall sodium pipeline by two alternate clamp designs. The first design consists of a band mounted directly on the pipe and is called the hot clamp. The second design consists of a band mounted using insulation standoffs and is called the cold clamp. Pipe stress levels induced by transient thermal dead weight and seismic loads are discussed. Pipe stress levels and system dynamic spring rates are presented. Procedures utilized to combine clamp induced pipe stress with other short and long term pipe system stresses are detailed. Recommendations for practical application in LMFBR pipe systems are made

Downhole Fluid Analyzer Development

Energy Technology Data Exchange (ETDEWEB)

Bill Turner

2006-11-28

A novel fiber optic downhole fluid analyzer has been developed for operation in production wells. This device will allow real-time determination of the oil, gas and water fractions of fluids from different zones in a multizone or multilateral completion environment. The device uses near infrared spectroscopy and induced fluorescence measurement to unambiguously determine the oil, water and gas concentrations at all but the highest water cuts. The only downhole components of the system are the fiber optic cable and windows. All of the active components--light sources, sensors, detection electronics and software--will be located at the surface, and will be able to operate multiple downhole probes. Laboratory testing has demonstrated that the sensor can accurately determine oil, water and gas fractions with a less than 5 percent standard error. Once installed in an intelligent completion, this sensor will give the operating company timely information about the fluids arising from various zones or multilaterals in a complex completion pattern, allowing informed decisions to be made on controlling production. The research and development tasks are discussed along with a market analysis.

Geological controls on the occurrence of gas hydrate from core, downhole log, and seismic data in the Shenhu area, South China Sea

Science.gov (United States)

Xiujuan Wang,; ,; Collett, Timothy S.; Lee, Myung W.; Yang, Shengxiong; Guo, Yiqun; Wu, Shiguo

2014-01-01

Multi-channel seismic reflection data, well logs, and recovered sediment cores have been used in this study to characterize the geologic controls on the occurrence of gas hydrate in the Shenhu area of the South China Sea. The concept of the "gas hydrate petroleum system" has allowed for the systematic analysis of the impact of gas source, geologic controls on gas migration, and the role of the host sediment in the formation and stability of gas hydrates as encountered during the 2007 Guangzhou Marine Geological Survey Gas Hydrate Expedition (GMGS-1) in the Shenhu area. Analysis of seismic and bathymetric data identified seventeen sub-linear, near-parallel submarine canyons in this area. These canyons, formed in the Miocene, migrated in a northeasterly direction, and resulted in the burial and abandonment of canyons partially filled by coarse-grained sediments. Downhole wireline log (DWL) data were acquired from eight drill sites and sediment coring was conducted at five of these sites, which revealed the presence of suitable reservoirs for the occurrence of concentrated gas hydrate accumulations. Gas hydrate-bearing sediment layers were identified from well log and core data at three sites mainly within silt and silt clay sediments. Gas hydrate was also discovered in a sand reservoir at one site as inferred from the analysis of the DWL data. Seismic anomalies attributed to the presence of gas below the base of gas hydrate stability zone, provided direct evidence for the migration of gas into the overlying gas hydrate-bearing sedimentary sections. Geochemical analyses of gas samples collected from cores confirmed that the occurrence of gas hydrate in the Shenhu area is controlled by the presence thermogenic methane gas that has migrated into the gas hydrate stability zone from a more deeply buried source.

Characterizing Micro- and Macro-Scale Seismicity from Bayou Corne, Louisiana

Science.gov (United States)

Baig, A. M.; Urbancic, T.; Karimi, S.

2013-12-01

The initiation of felt seismicity in Bayou Corne, Louisiana, coupled with other phenomena detected by residents on the nearby housing development, prompted a call to install a broadband seismic network to monitor subsurface deformation. The initial deployment was in place to characterize the deformation contemporaneous with the formation of a sinkhole located in close proximity to a salt dome. Seismic events generated during this period followed a swarm-like behaviour with moment magnitudes culminating around Mw2.5. However, the seismic data recorded during this sequence suffer from poor signal to noise, onsets that are very difficult to pick, and the presence of a significant amount of energy arriving later in the waveforms. Efforts to understand the complexity in these waveforms are ongoing, and involve invoking the complexities inherent in recording in a highly attenuating swamp overlying a complex three-dimensional structure with the strong material property contrast of the salt dome. In order to understand the event character, as well as to locally lower the completeness threshold of the sequence, a downhole array of 15 Hz sensors was deployed in a newly drilled well around the salt dome. Although the deployment lasted a little over a month in duration, over 1000 events were detected down to moment magnitude -Mw3. Waveform quality tended to be excellent, with very distinct P and S wave arrivals observable across the array for most events. The highest magnitude events were seen as well on the surface network and allowed for the opportunity to observe the complexities introduced by the site effects, while overcoming the saturation effects on the higher-frequency downhole geophones. This hybrid downhole and surface array illustrates how a full picture of subsurface deformation is only made possible by combining the high-frequency downhole instrumentation to see the microseismicity complemented with a broadband array to accurately characterize the source

Downhole pressure sensor

Science.gov (United States)

Berdahl, C. M.

1980-01-01

Sensor remains accurate in spite of varying temperatures. Very accurate, sensitive, and stable downhole pressure measurements are needed for vaiety of reservoir engineering applications, such as deep petroleum reservoirs, especially gas reservoirs, and in areas of high geothermal gradient.

Processing Approaches for DAS-Enabled Continuous Seismic Monitoring

Science.gov (United States)

Dou, S.; Wood, T.; Freifeld, B. M.; Robertson, M.; McDonald, S.; Pevzner, R.; Lindsey, N.; Gelvin, A.; Saari, S.; Morales, A.; Ekblaw, I.; Wagner, A. M.; Ulrich, C.; Daley, T. M.; Ajo Franklin, J. B.

2017-12-01

Distributed Acoustic Sensing (DAS) is creating a "field as laboratory" capability for seismic monitoring of subsurface changes. By providing unprecedented spatial and temporal sampling at a relatively low cost, DAS enables field-scale seismic monitoring to have durations and temporal resolutions that are comparable to those of laboratory experiments. Here we report on seismic processing approaches developed during data analyses of three case studies all using DAS-enabled seismic monitoring with applications ranging from shallow permafrost to deep reservoirs: (1) 10-hour downhole monitoring of cement curing at Otway, Australia; (2) 2-month surface monitoring of controlled permafrost thaw at Fairbanks, Alaska; (3) multi-month downhole and surface monitoring of carbon sequestration at Decatur, Illinois. We emphasize the data management and processing components relevant to DAS-based seismic monitoring, which include scalable approaches to data management, pre-processing, denoising, filtering, and wavefield decomposition. DAS has dramatically increased the data volume to the extent that terabyte-per-day data loads are now typical, straining conventional approaches to data storage and processing. To achieve more efficient use of disk space and network bandwidth, we explore improved file structures and data compression schemes. Because noise floor of DAS measurements is higher than that of conventional sensors, optimal processing workflow involving advanced denoising, deconvolution (of the source signatures), and stacking approaches are being established to maximize signal content of DAS data. The resulting workflow of data management and processing could accelerate the broader adaption of DAS for continuous monitoring of critical processes.

Seismic restraint means for radiation detector

International Nuclear Information System (INIS)

Underwood, R.H.; Todt, W.H.

1983-01-01

Seismic restraint means are provided for mounting an elongated, generally cylindrical nuclear radiation detector within a tubular thimble in a nuclear reactor monitor system. The restraint means permits longitudinal movement of the radiation detector into and out of the thimble. Each restraint means comprises a split clamp ring and a plurality of symmetrically spaced support arms pivotally mounted on the clamp ring. Each support arm has spring bias means and thimble contact means eg insulating rollers whereby the contact means engage the thimble with a constant predetermined force which minimizes seismic vibration action on the radiation detector. (author)

Interpretation of Seismic Cone Penetration Testing in Silty Soil

DEFF Research Database (Denmark)

Holmsgaard, Rikke; Ibsen, Lars Bo; Nielsen, Benjaminn Nordahl

2016-01-01

Five Seismic Cone Penetration Tests (SCPT) were conducted at a test site in northern Denmark where the subsoil consists primarily of sandy silt with clay bands. A portion of the test data were collected every 0.5 m to compare the efficacy of closely-spaced down-hole data collection on the computa...

Imaging Fracking Zones by Microseismic Reverse Time Migration for Downhole Microseismic Monitoring

Science.gov (United States)

Lin, Y.; Zhang, H.

2015-12-01

Hydraulic fracturing is an engineering tool to create fractures in order to better recover oil and gas from low permeability reservoirs. Because microseismic events are generally associated with fracturing development, microseismic monitoring has been used to evaluate the fracking process. Microseismic monitoring generally relies on locating microseismic events to understand the spatial distribution of fractures. For the multi-stage fracturing treatment, fractures created in former stages are strong scatterers in the medium and can induce strong scattering waves on the waveforms for microseismic events induced during later stages. In this study, we propose to take advantage of microseismic scattering waves to image fracking zones by using seismic reverse time migration method. For downhole microseismic monitoring that involves installing a string of seismic sensors in a borehole near the injection well, the observation geometry is actually similar to the VSP (vertical seismic profile) system. For this reason, we adapt the VSP migration method for the common shot gather to the common event gather. Microseismic reverse-time migration method involves solving wave equation both forward and backward in time for each microseismic event. At current stage, the microseismic RTM is based on 2D acoustic wave equation (Zhang and Sun, 2008), solved by the finite-difference method with PML absorbing boundary condition applied to suppress the reflections of artificial boundaries. Additionally, we use local wavefield decomposition instead of cross-correlation imaging condition to suppress the imaging noise. For testing the method, we create a synthetic dataset for a downhole microseismic monitoring system with multiple fracking stages. It shows that microseismic migration using individual event is able to clearly reveal the fracture zone. The shorter distance between fractures and the microseismic event the clearer the migration image is. By summing migration images for many

Clamping characteristics study on different types of clamping unit

Energy Technology Data Exchange (ETDEWEB)

Jiao, Zhiwei; Liu, Haichao; Xie, Pengcheng [College of Mechanical and Electrical Engineering, Beijing University of Chemical Technology, Beijing China 100029 (China); Yang, Weimin [College of Mechanical and Electrical Engineering, Beijing University of Chemical Technology, Beijing China 100029 (China); State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing China 100029 (China)

2015-05-22

Plastic products are becoming more and more widely used in aerospace, IT, digital electronics and many other fields. With the development of technology, the requirement of product precision is getting higher and higher. However, type and working performance of clamping unit play a decisive role in product precision. Clamping characteristics of different types of clamping unit are discussed in this article, which use finite element numerical analysis method through the software ABAQUS to study the clamping uniformity, and detect the clamping force repeatability precision. The result shows that compared with toggled three-platen clamping unit, clamping characteristics of internal circulation two-platen clamping unit are better, for instance, its mold cavity deformation and force that bars and mold parting surface suffered are more uniform, and its clamping uniformity and repeatability precision is also better.

Geotechnical investigation for seismic issues for K-reactor area at Savannah River Site

International Nuclear Information System (INIS)

Castro, G.; Reeves, C.Q.

1991-01-01

A geotechnical investigation has been completed at Savannah River Site to characterize the foundation conditions in K-Reactor Area and confirm soil design properties for use in seismic qualification of structures. The scope of field work included ten soil borings to a 200-foot depth with split-spoon and undisturbed sampling. Additionally, 42 cone penetrometer tests were performed with seismic down-hole measurements. Three cross-hole shear wave velocity tests were also completed to confirm the assumed dynamic properties which had been used in preliminary seismic analysis

DOWNHOLE POWER GENERATION AND WIRELESS COMMUNICATIONS FOR INTELLIGENT COMPLETIONS APPLICATIONS

Energy Technology Data Exchange (ETDEWEB)

Paul Tubel

2004-02-01

The development work during this quarter was focused in the assembly of the downhole power generator hardware and its electronics module. The quarter was also spent in the development of the surface system electronics and software to extract the acoustic data transmitted from downhole to the surface from the noise generated by hydrocarbon flow in wells and to amplify very small acoustic signals to increase the distance between the downhole tool and the surface receiver. The tasks accomplished during this report period were: (1) Assembly of the downhole power generator mandrel for generation of electrical power due to flow in the wellbore. (2) Test the piezoelectric wafers to assure that they are performing properly prior to integrating them to the mechanical power generator mandrel. (3) Coat the power generator wafers to prevent water from shorting the power generator wafers. (4) Test of the power generator using a water tower and an electric pump to create a water flow loop. (5) Test the power harvesting electronics module. (6) Upgrade the signal condition and amplification from downhole into the surface system. (7) Upgrade the surface processing system capability to process data faster. (8) Create a new filtering technique to extract the signal from noise after the data from downhole is received at the surface system.

Topology Optimization of an Actively Cooled Electronics Section for Downhole Tools

DEFF Research Database (Denmark)

Soprani, Stefano; Klaas Haertel, Jan Hendrik; Lazarov, Boyan Stefanov

2015-01-01

Active cooling systems represent a possible solution to the electronics overheating that occurs in wireline downhole tools operating in high temperature oil and gas wells. A Peltier cooler was chosen to maintain the downhole electronics to a tolerable temperature, but its integration into the dow......Active cooling systems represent a possible solution to the electronics overheating that occurs in wireline downhole tools operating in high temperature oil and gas wells. A Peltier cooler was chosen to maintain the downhole electronics to a tolerable temperature, but its integration......, according to the topology optimization results and assembly constraints, and compared to the optimized cases....

Is early cord clamping, delayed cord clamping or cord milking best?

Science.gov (United States)

Vatansever, Binay; Demirel, Gamze; Ciler Eren, Elif; Erel, Ozcan; Neselioglu, Salim; Karavar, Hande Nur; Gundogdu, Semra; Ulfer, Gozde; Bahadir, Selcen; Tastekin, Ayhan

2018-04-01

To compare the antioxidant status of three cord clamping procedures (early clamping, delayed clamping and milking) by analyzing the thiol-disulfide balance. This randomized controlled study enrolled 189 term infants who were divided into three groups according to the cord clamping procedure: early clamping, delayed clamping and milking. Blood samples were collected from the umbilical arteries immediately after clamping, and the thiol/disulfide homeostasis was analyzed. The native and total thiol levels were significantly (p total thiol ratio was significantly (p = .026) lower in the delayed cord clamping and milking groups compared with the early clamping groups. Early cord clamping causes the production of more disulfide bonds and lower thiol levels, indicating that oxidation reactions are increased in the early cord clamping procedure compared with the delayed cord clamping and milking procedures. The oxidant capacity is greater with early cord clamping than with delayed clamping or cord milking. Delayed cord clamping or milking are beneficial in neonatal care, and we suggest that they be performed routinely in all deliveries.

Passive thermal management system for downhole electronics in harsh thermal environments

International Nuclear Information System (INIS)

Shang, Bofeng; Ma, Yupu; Hu, Run; Yuan, Chao; Hu, Jinyan; Luo, Xiaobing

2017-01-01

Highlights: • A passive thermal management system is proposed for downhole electronics. • Electronics temperature can be maintained within 125 °C for six-hour operating time. • The result shows potential application for the logging tool in oil and gas industry. - Abstract: The performance and reliability of downhole electronics will degrade in high temperature environments. Various active cooling techniques have been proposed for thermal management of such systems. However, these techniques require additional power input, cooling liquids and other moving components which complicate the system. This study presents a passive Thermal Management System (TMS) for downhole electronics. The TMS includes a vacuum flask, Phase Change Material (PCM) and heat pipes. The thermal characteristics of the TMS is evaluated experimentally. The results show that the system maintains equipment temperatures below 125 °C for a six-hour operating period in a 200 °C downhole environment, which will effectively protect the downhole electronics.

Seismic Readings from the Deepest Borehole in the New Madrid Seismic Zone

Energy Technology Data Exchange (ETDEWEB)

Woolery, Edward W [KY Geological Survey, Univ of KY; Wang, Zhenming [KY Geological Survey, Univ of KY; Sturchio, Neil C [Dept of earth and Env. Sciences, Univ of Ill at Chicago

2006-03-01

Since the 1980s, the research associated with the UK network has been primarily strong-motion seismology of engineering interest. Currently the University of Kentucky operates a strong-motion network of nine stations in the New Madrid Seismic Zone. A unique feature of the network is the inclusions of vertical strong-motion arrays, each with one or two downhole accelerometers. The deepest borehole array is 260 m below the surfaces at station VASA in Fulton County, Kentucky. A preliminary surface seismic refraction survey was conducted at the site before drilling the hole at VSAS (Woolery and Wang, 2002). The depth to the Paleozoic bedrock at the site was estimated to be approximately 595 m, and the depth to the first very stiff layer (i.e. Porters Creek Clay) was found to be about 260 m. These depths and stratigraphic interpretation correlated well with a proprietary seismic reflection line and the Ken-Ten Oil Exploration No. 1 Sanger hole (Schwalb, 1969), as well as our experience in the area (Street et al., 1995; Woolery et al., 1999).

Gas hydrate identified in sand-rich inferred sedimentary section using downhole logging and seismic data in Shenhu area, South China Sea

Science.gov (United States)

Wang, Xiujuan; Lee, Myung W.; Collett, Timothy S.; Yang, Shengxiong; Guo, Yiqun; Wu, Shiguo

2014-01-01

Downhole wireline log (DWL) data was acquired from eight drill sites during China's first gas hydrate drilling expedition (GMGS-1) in 2007. Initial analyses of the acquired well log data suggested that there were no significant gas hydrate occurrences at Site SH4. However, the re-examination of the DWL data from Site SH4 indicated that there are two intervals of high resistivity, which could be indicative of gas hydrate. One interval of high resistivity at depth of 171–175 m below seafloor (mbsf) is associated with a high compressional- wave (P-wave) velocities and low gamma ray log values, which suggests the presence of gas hydrate in a potentially sand-rich (low clay content) sedimentary section. The second high resistivity interval at depth of 175–180 mbsf is associated with low P-wave velocities and low gamma values, which suggests the presence of free gas in a potentially sand-rich (low clay content) sedimentary section. Because the occurrence of free gas is much shallower than the expected from the regional depth of the bottom simulating reflector (BSR), the free gas could be from the dissociation of gas hydrate during drilling or there may be a local anomaly in the depth to the base of the gas hydrate stability zone. In order to determine whether the low P-wave velocity with high resistivity is caused by in-situ free gas or dissociated free gas from the gas hydrate, the surface seismic data were also used in this analysis. The log analysis incorporating the surface seismic data through the construction of synthetic seismograms using various models indicated the presence of free gas directly in contact with an overlying gas hydrate-bearing section. The occurrence of the anomalous base of gas hydrate stability at Site SH4 could be caused by a local heat flow conditions. This paper documents the first observation of gas hydrate in what is believed to be a sand-rich sediment in Shenhu area of the South China Sea.

Early Detection and Localization of Downhole Incidents in Managed Pressure Drilling

DEFF Research Database (Denmark)

Willersrud, Anders; Imsland, Lars; Blanke, Mogens

2015-01-01

Downhole incidents such as kick, lost circulation, pack-off, and hole cleaning issues are important contributors to downtime in drilling. In managed pressure drilling (MPD), operations margins are typically narrower, implying more frequent incidents and more severe consequences. Detection...... and handling of symptoms of downhole drilling contingencies at an early stage are therefore crucial for the reliability and safety of MPD operations. In this paper we describe a method for early detection and localization of such incidents, based on a fit for purpose model of the downhole pressure hydraulics...... successfully been tested on experimental data from a medium-scale horizontal flow loop in Sta- vanger, Norway. The flow loop represents a 700 m borehole with emulation of the following downhole contingencies: drillstring washout, drill bit nozzle plugging, gas influx and fluid loss. In the tests...

The planning of a passive seismic experiment: the Ketzin case

Science.gov (United States)

Rossi, G.; Petronio, L.

2009-04-01

In the last years, it has been recognized the importance of using microseismic activity data to gain information on the state and dynamics of a reservoir, notwithstanding the difficulties of recording, localizing the events, interpret them correctly, in terms of developing fractures, or thermal effects. The increasing number of CO2 storage experiments, with the necessity of providing efficient, economic, and long-term monitoring methods, both in the injection and post-injection phases, further encourage the development and improvement of recording and processing techniques. Microseismic signals are typically recorded with downhole sensors. Monitoring with surface sensors is problematic due to increased noise levels and signal attenuation particularly in the near surface. The actual detection distance depends on background noise conditions, seismic attenuation and the microseismic source strength. In the frame of the European project Co2ReMoVe and of the European Network of Excellence Co2GeoNet, a passive seismic experiment was planned in the Ketzin site for geological storage of CO2, a former gas store near Potsdam, object of the CO2SINK European project and inserted also in the European project Co2ReMoVe. Aim of the survey is to complement the CO2-SINK active seismic downhole experiments, adding precious information on the microseismicity induced by stress field changes at the reservoir level and in the overburden, due to the CO2 injection. The baseline survey was done in May 2008 by the Istituto Nazionale di Oceanografia e di Geofisica Sperimentale-OGS (Italy), with the support of the Deutsches GeoForschungsZentrum-GFZ (Germany) and the collaboration of the Institut für Geowissenschaftliche Gemeinschaftsaufgaben-GGA (Germany), shortly before the starting of the CO2 injection (June 30th 2008). A continuous monitoring (about 5 days) was performed by 2 downhole 3C geophones, and 3 surface 3C geophones located around the wells. This paper, based on the analysis of

Amplification Factors for Spectral Acceleration Using Borehole Seismic Array in Taiwan

Science.gov (United States)

Lai, T. S.; Yih-Min, W.; Chao, W. A.; Chang, C. H.

2017-12-01

In order to reduce the noise from surface to get the high-quality seismic recordings, there are 54 borehole seismic arrays have been installed in Taiwan deployed by Central Weather Bureau (CWB) until the end of 2016. Each array includes two force balance accelerometers, one at the surface and other inside the borehole, as well as one broadband seismometer inside the borehole. The downhole instruments are placed at a depth between 120 and 400 m. The background noise level are lower at the borehole stations, but the amplitudes recorded by borehole stations are smaller than surface stations for the same earthquake due to the different geology conditions. Therefore, the earthquake magnitude estimated by borehole station is smaller than surface station. So far, CWB only use the surface stations in the magnitude determination due to this situation. In this study, we investigate the site effects between surface and downhole for borehole seismic arrays. Using the spectral ratio derived by the two-station spectral method as the transfer function, simulated the waveform recorded by borehole stations to the surface stations. In the future, through the transfer function, the borehole stations will be included in the estimation of earthquake magnitude and the results of amplification factors can provide the information of near-surface site effects for the ground motion simulation applications.

Photovoltaic panel clamp

Science.gov (United States)

Mittan, Margaret Birmingham [Oakland, CA; Miros, Robert H. J. [Fairfax, CA; Brown, Malcolm P [San Francisco, CA; Stancel, Robert [Loss Altos Hills, CA

2012-06-05

A photovoltaic panel clamp includes an upper and lower section. The interface between the assembled clamp halves and the module edge is filled by a flexible gasket material, such as EPDM rubber. The gasket preferably has small, finger like protrusions that allow for easy insertion onto the module edge while being reversed makes it more difficult to remove them from the module once installed. The clamp includes mounting posts or an integral axle to engage a bracket. The clamp also may include a locking tongue to secure the clamp to a bracket.

Selective Arterial Clamping Versus Hilar Clamping for Minimally Invasive Partial Nephrectomy.

Science.gov (United States)

Yezdani, Mona; Yu, Sue-Jean; Lee, David I

2016-05-01

Partial nephrectomy has become an accepted treatment of cT1 renal masses as it provides improved long-term renal function compared to radical nephrectomy (Campbell et al. J Urol. 182:1271-9, 2009). Hilar clamping is utilized to help reduce bleeding and improve visibility during tumor resection. However, concern over risk of kidney injury with hilar clamping has led to new techniques to reduce length of warm ischemia time (WIT) during partial nephrectomy. These techniques have progressed over the years starting with early hilar unclamping, controlled hypotension during tumor resection, selective arterial clamping, minimal margin techniques, and off-clamp procedures. Selective arterial clamping has progressed significantly over the years. The main question is what are the exact short- and long-term renal effects from increasing clamp time. Moreover, does it make sense to perform these more time-consuming or more complex procedures if there is no long-term preservation of kidney function? More recent studies have shown no difference in renal function 6 months from surgery when selective arterial clamping or even hilar clamping is employed, although there is short-term improved decline in estimated glomerular filtration rate (eGFR) with selective clamping and off-clamp techniques (Komninos et al. BJU Int. 115:921-8, 2015; Shah et al. 117:293-9, 2015; Kallingal et al. BJU Int. doi: 10.1111/bju.13192, 2015). This paper reviews the progression of total hilar clamping to selective arterial clamping (SAC) and the possible difference its use makes on long-term renal function. SAC may be attempted based on surgeon's decision-making, but may be best used for more complex, larger, more central or hilar tumors and in patients who have renal insufficiency at baseline or a solitary kidney.

Controlled-source seismic interferometry with one way wave fields

Science.gov (United States)

van der Neut, J.; Wapenaar, K.; Thorbecke, J. W.

2008-12-01

In Seismic Interferometry we generally cross-correlate registrations at two receiver locations and sum over an array of sources to retrieve a Green's function as if one of the receiver locations hosts a (virtual) source and the other receiver location hosts an actual receiver. One application of this concept is to redatum an area of surface sources to a downhole receiver location, without requiring information about the medium between the sources and receivers, thus providing an effective tool for imaging below complex overburden, which is also known as the Virtual Source method. We demonstrate how elastic wavefield decomposition can be effectively combined with controlled-source Seismic Interferometry to generate virtual sources in a downhole receiver array that radiate only down- or upgoing P- or S-waves with receivers sensing only down- or upgoing P- or S- waves. For this purpose we derive exact Green's matrix representations from a reciprocity theorem for decomposed wavefields. Required is the deployment of multi-component sources at the surface and multi- component receivers in a horizontal borehole. The theory is supported with a synthetic elastic model, where redatumed traces are compared with those of a directly modeled reflection response, generated by placing active sources at the virtual source locations and applying elastic wavefield decomposition on both source and receiver side.

Design of a Novel Electro-hydraulic Drive Downhole Tractor

Science.gov (United States)

Fang, Delei; Shang, Jianzhong; Yang, Junhong; Wang, Zhuo; Wu, Wei

2018-02-01

In order to improve the traction ability and the work efficiency of downhole tractor in oil field, a novel electro-hydraulic drive downhole tractor was designed. The tractor’s supporting mechanism and moving mechanism were analyzed based on the tractor mechanical structure. Through the introduction of hydraulic system, the hydraulic drive mechanism and the implementation process were researched. Based on software, analysis of tractor hydraulic drive characteristic and movement performance were simulated, which provide theoretical basis for the development of tractor prototype.

Battery switch for downhole tools

Science.gov (United States)

Boling, Brian E.

2010-02-23

An electrical circuit for a downhole tool may include a battery, a load electrically connected to the battery, and at least one switch electrically connected in series with the battery and to the load. The at least one switch may be configured to close when a tool temperature exceeds a selected temperature.

Extreme loads seismic testing of conduit systems

International Nuclear Information System (INIS)

Howard, G.E.; Ibanez, P.; Harrison, S.; Shi, Z.T.

1991-01-01

Rigid steel conduit (thin-wall tubes with threaded connections) containing electrical cabling are a common feature in nuclear power plants. Conduit systems are in many cases classified in U.S.A. practice as Seismic Category I structures. this paper summarizes results and others aspects of a dynamic test program conducted to investigate conduit systems seismic performance under three-axis excitation for designs representative at a nuclear power plant sited near Ft. Worth, Texas (a moderate seismic zone), with a Safe Shutdown Earthquake (SSE) of 0.12 g. Test specimens where subjected to postulated seismic events, including excitation well in excess of Safe Shutdown Earthquake events typical for U.S.A. nuclear power stations. A total of 18 conduit systems of 9-meter nominal lengths were shake table mounted and subjected to a variety of tests. None of the specimens suffered loss of load capacity when subjected to a site-enveloping Safe Shutdown Earthquake (SSE). Clamp/attachment hardware failures only began to occur when earthquake input motion was scaled upward to minimum values of 2.3-4.6 times site enveloping SSE response spectra. Tensile and/or shear failure of clamp attachment bolts or studs was the failure mode in all case in which failure was induced. (author)

Horizontal Acoustic Barriers for Protection from Seismic Waves

Directory of Open Access Journals (Sweden)

Sergey V. Kuznetsov

2011-01-01

Full Text Available The basic idea of a seismic barrier is to protect an area occupied by a building or a group of buildings from seismic waves. Depending on nature of seismic waves that are most probable in a specific region, different kinds of seismic barriers can be suggested. Herein, we consider a kind of a seismic barrier that represents a relatively thin surface layer that prevents surface seismic waves from propagating. The ideas for these barriers are based on one Chadwick's result concerning nonpropagation condition for Rayleigh waves in a clamped half-space, and Love's theorem that describes condition of nonexistence for Love waves. The numerical simulations reveal that to be effective the length of the horizontal barriers should be comparable to the typical wavelength.

Gamma-ray spectrometry applied to down-hole logging

International Nuclear Information System (INIS)

Dumesnil, P.; Umiastowsky, K.

1983-11-01

Gamma-ray spectrometry permits to improve the accuracy of natural gamma, gamma-gamma and neutron-gamma geophysical measurements. The probe developed at Centre d'Etudes Nucleaires de Saclay allows down-hole gamma-ray spectrometry. Among others, this probe can be applied to the uranium content determination by selective natural gamma method, down-hole determination of the ash content in the coal by gamma-gamma selective method and elemental analysis by neutron-gamma method. For the calibration and an exact interpretation of the measurements it is important to know the gamma-ray and neutron characteristics of the different kinds of rocks considered as probabilistic variables

Air distribution system with the discharge action in the working cavity of downhole air hammer drills

Science.gov (United States)

Timonin, VV; Alekseev, SE; Kokoulin, DI; Kubanychbek, B.

2018-03-01

It is proposed to carry out pre-mine methane drainage using underground degassing holes made by downhole air hammer drills. The features of downhole air drills are described. The downhole air drill layout with the simple-shape striking part is presented with its pluses and minuses. The researchers point at available options to eliminate the shortcomings. The improved layout of the downhole air hammer drill is suggested. The paper ends with the test data on the prototype air hammer drill, its characteristics and trial drilling results.

Tuning Fork Oscillators as Downhole Viscometers in Oilfield Applications

Science.gov (United States)

Gonzalez, Miguel; Bernero, Greg; Alvarez, Oliverio; Ham, Gregory; Max, Deffenbaugh; Sensors Development Team

2015-03-01

The commerciality of oil wells is greatly influenced by the physical properties of the fluids being produced. A key parameter in determining how producible the hydrocarbons are is their viscosity. Pressure and temperature changes in recovering a downhole sample to the surface can alter viscosity while accurate downhole measurement of this critical property remains a rudimentary effort in the industry. In this presentation we describe the challenges of measuring and quantifying the viscosity of reservoir fluids in situ at downhole conditions, as well as present an overview of some of the different measurement techniques currently used. Additionally, we show our characterization of a piezoelectric tuning fork oscillator used as a viscosity sensor. In an attempt to recreate the environment found in oil wells, its mechanical and electrical properties were studied while the device was immersed in different fluids and, separately, under different conditions of pressure and temperature. This device is a first step toward the development of an inexpensive, integrated, and miniaturized sensing platform for the in situ characterization of reservoir fluids.

Deghosting, Demultiple, and Deblurring in Controlled-Source Seismic Interferometry

Directory of Open Access Journals (Sweden)

Joost van der Neut

2011-01-01

Full Text Available With controlled-source seismic interferometry we aim to redatum sources to downhole receiver locations without requiring a velocity model. Interferometry is generally based on a source integral over cross-correlation (CC pairs of full, perturbed (time-gated, or decomposed wavefields. We provide an overview of ghosts, multiples, and spatial blurring effects that can occur for different types of interferometry. We show that replacing cross-correlation by multidimensional deconvolution (MDD can deghost, demultiple, and deblur retrieved data. We derive and analyze MDD for perturbed and decomposed wavefields. An interferometric point spread function (PSF is introduced that can be obtained directly from downhole data. Ghosts, multiples, and blurring effects that may populate the retrieved gathers can be locally diagnosed with the PSF. MDD of perturbed fields can remove ghosts and deblur retrieved data, but it leaves particular multiples in place. To remove all overburden-related effects, MDD of decomposed fields should be applied.

Seismic analysis of piping with nonlinear supports

International Nuclear Information System (INIS)

Barta, D.A.; Huang, S.N.; Severud, L.K.

1980-01-01

The modeling and results of nonlinear time-history seismic analyses for three sizes of pipelines restrained by mechanical snubbes are presented. Numerous parametric analyses were conducted to obtain sensitivity information which identifies relative importance of the model and analysis ingredients. Special considerations for modeling the pipe clamps and the mechanical snubbers based on experimental characterization data are discussed. Comparisions are also given of seismic responses, loads and pipe stresses predicted by standard response spectra methods and the nonlinear time-history methods

Downhole transmission system comprising a coaxial capacitor

Science.gov (United States)

Hall, David R [Provo, UT; Pixton, David S [Lehi, UT; Johnson, Monte L [Orem, UT; Bartholomew, David B [Springville, UT; Hall, Jr., H. Tracy; Rawle, Michael [Springville, UT

2011-05-24

A transmission system in a downhole component comprises a plurality of data transmission elements. A coaxial cable having an inner conductor and an outer conductor is disposed within a passage in the downhole component such that at least one capacitor is disposed in the passage and having a first terminal coupled to the inner conductor and a second terminal coupled to the outer conductor. Preferably the transmission element comprises an electrically conducting coil. Preferably, within the passage a connector is adapted to electrically connect the inner conductor of the coaxial cable and the lead wire. The coaxial capacitor may be disposed between and in electrically communication with the connector and the passage. In another embodiment a connector is adapted to electrical connect a first and a second portion of the inner conductor of the coaxial cable and a coaxial capacitor is in electrical communication with the connector and the passage.

Advanced Seismic While Drilling System

Energy Technology Data Exchange (ETDEWEB)

Robert Radtke; John Fontenot; David Glowka; Robert Stokes; Jeffery Sutherland; Ron Evans; Jim Musser

2008-06-30

. An APS Turbine Alternator powered the SeismicPULSER{trademark} to produce two Hz frequency peak signals repeated every 20 seconds. Since the ION Geophysical, Inc. (ION) seismic survey surface recording system was designed to detect a minimum downhole signal of three Hz, successful performance was confirmed with a 5.3 Hz recording with the pumps running. The two Hz signal generated by the sparker was modulated with the 3.3 Hz signal produced by the mud pumps to create an intense 5.3 Hz peak frequency signal. The low frequency sparker source is ultimately capable of generating selectable peak frequencies of 1 to 40 Hz with high-frequency spectra content to 10 kHz. The lower frequencies and, perhaps, low-frequency sweeps, are needed to achieve sufficient range and resolution for realtime imaging in deep (15,000 ft+), high-temperature (150 C) wells for (a) geosteering, (b) accurate seismic hole depth, (c) accurate pore pressure determinations ahead of the bit, (d) near wellbore diagnostics with a downhole receiver and wired drill pipe, and (e) reservoir model verification. Furthermore, the pressure of the sparker bubble will disintegrate rock resulting in an increased overall rates of penetration. Other applications for the SeismicPULSER{trademark} technology are to deploy a low-frequency source for greater range on a wireline for Reverse Vertical Seismic Profiling (RVSP) and Cross-Well Tomography. Commercialization of the technology is being undertaken by first contacting stakeholders to define the value proposition for rig site services utilizing SeismicPULSER{trademark} technologies. Stakeholders include national oil companies, independent oil companies, independents, service companies, and commercial investors. Service companies will introduce a new Drill Bit SWD service for deep HTHP wells. Collaboration will be encouraged between stakeholders in the form of joint industry projects to develop prototype tools and initial field trials. No barriers have been identified

Use of the Satinsky clamp for hilar clamping during robotic partial nephrectomy: indications, technique, and multi-center outcomes.

Science.gov (United States)

Abdullah, Newaj; Rahbar, Haider; Barod, Ravi; Dalela, Deepansh; Larson, Jeff; Johnson, Michael; Mass, Alon; Zargar, Homayoun; Kaouk, Jihad; Allaf, Mohamad; Bhayani, Sam; Stifelman, Michael; Rogers, Craig

2017-03-01

A Satinsky clamp may be a backup option for hilar clamping during robotic partial nephrectomy (RPN) if there are challenges with application of bulldog clamps, but there are potential safety concerns. We evaluate outcomes of RPN using Satinsky vs. bulldog clamps, and provide tips for safe use of the Satinsky as a backup option. Using a multi-center database, we identified 1073 patients who underwent RPN between 2006 and 2013, and had information available about method of hilar clamping (bulldog clamp vs. Satinsky clamp). Patient baseline characteristics, tumor features, and perioperative outcomes were compared between the Satinsky and bulldog clamp groups. A Satinsky clamp was used for hilar clamping in 94 (8.8 %) RPN cases, and bulldog clamps were used in 979 (91.2 %) cases. The use of a Satinsky clamp was associated with greater operative time (198 vs. 175 min, p hilar clamping during challenging RPN cases, but requires careful technique, and was rarely necessary.

Study on Dynamic Response of Downhole Tools under Perforation Impact Load

Directory of Open Access Journals (Sweden)

Liu Jun

2017-01-01

Full Text Available A model of a multibody system is established to investigate the dynamic response of an oil tube-shock absorber-perforating gun system in downhole perforation-test joint operation. In the model, the oil tube and perforating gun are modeled as elastic rods and the shock absorber is modeled as single particle system with damping and a spring. Two force continuity conditions are used to simulate the interactions among the three components. The perforation impact load is determined by an experiment of underwater explosion of perforating bullets. Using the model, the effects of charge quantity of perforating bullet, the number of shock absorbers, and the length of oil tube on the dynamic response of oil tube and packer are investigated. On this basis, a basic principle of the combination design of shock absorber and oil tube is proposed to improve the mechanical state of downhole tools. The study results can provide theoretical support for the design of downhole perforation-test joint operation.

Radial wedge flange clamp

Science.gov (United States)

Smith, Karl H.

2002-01-01

A radial wedge flange clamp comprising a pair of flanges each comprising a plurality of peripheral flat wedge facets having flat wedge surfaces and opposed and mating flat surfaces attached to or otherwise engaged with two elements to be joined and including a series of generally U-shaped wedge clamps each having flat wedge interior surfaces and engaging one pair of said peripheral flat wedge facets. Each of said generally U-shaped wedge clamps has in its opposing extremities apertures for the tangential insertion of bolts to apply uniform radial force to said wedge clamps when assembled about said wedge segments.

Wind seismic noise introduced by external infrastructure: field data and transfer mechanism

Science.gov (United States)

Martysevich, Pavel; Starovoyt, Yuri

2017-04-01

Background seismic noise generated by wind was analyzed at six co-located seismic and infrasound arrays with the use of the wind speed data. The main factors affecting the noise level were identified as (a) external structures as antenna towers for intrasite communication, vegetation and heavy solar panels fixtures, (b) borehole casing and (c) local lithology. The wind-induced seismic noise peaks in the spectra can be predicted by combination of inverted pendulum model for antenna towers and structures used to support solar panels, free- or clamped-tube resonance of the borehole casing and is dependent on the type of sedimentary upper layer. Observed resonance frequencies are in agreement with calculated clamped / free tube modes for towers and borehole casings. Improvement of the seismic data quality can be achieved by minimizing the impact of surrounding structures close to seismic boreholes. The need and the advantage of the borehole installation may vanish and appear to be even not necessary at locations with non-consolidated sediments because the impact of surrounding structures on seismic background may significantly deteriorate the installation quality and therefore the detection capability of the array. Several IMS arrays where the radio telemetry antennas are used for data delivery to the central site may benefit from the redesign of the intrasite communication system by its substitute with the fiber-optic net as less harmful engineering solution.

The plastic instability of clamped-clamped conical thin-walled pipe reducers

International Nuclear Information System (INIS)

Awad, Ibrahim; Saleh, Ch.A.R.; Ragab, A.R.

2016-01-01

The analytical study for plastic deformation of clamped–clamped conical reducer pipe under internal pressure does not deduce a closed form expression for the pressure at plastic instability. The presented study employs finite element analysis (FEA) to estimate the internal pressure at instability for conical reducers made of different materials and having different dimensional configurations. Forty dimensional configurations, classified as medium type, and five types of materials have been included in the analysis using ABAQUS package. A correlation expression is derived by nonlinear regression to predict the instability pressure. The proposed expression is verified for other dimensional configurations out of the above used forty models and for other materials. Experiments have been conducted by pressurizing conical clamped-clamped reducers until bursting in order to verify the finite element models. Comparison of instability pressures, strains and deflections at specific points along the conical surface shows satisfactory agreement between analysis and experiments. - Highlights: • This study offers a parametric study of the plastic instability pressure of clamped-clamped conical reducers. • A closed form analytical expression for the instability pressure is derived by using nonlinear regression. • The finite element analysis is validated by conducting bursting tests.

Downhole adjustable bent assemblies

International Nuclear Information System (INIS)

Askew, W.E.

1992-01-01

This patent describes downhole adjustable apparatus for creating a bend angle in order to affect the inclination of a drilled borehole. It comprises an upper tubular member having an upper portion and a lower portion; lower tubular member having an upper portion and a lower portion; one of the portions being received within the other for relative rotational movement about an axis that is inclined with respect to the the longitudinal axes of the members, whereby in a first rotational position the longitudinal axes have one geometrical relationship, and in a second rotational position the longitudinal axes have a second, different geometrical relationship

Seismic study of soil dynamics at Garner Valley, California

International Nuclear Information System (INIS)

Archuleta, R.J.; Seale, S.H.

1990-01-01

The Garner Valley downhole array (GVDA) of force-balanced accelerometers was designed to determine the effect that near-surface soil layers have on surface ground motion by measuring in situ seismic waves at various depths. Although there are many laboratory, theoretical and numerical studies that are used to predict the effects that local site geology might have on seismic waves, there are very few direct measurements that can be used to confirm the predictions made by these methods. The effects of local site geology on seismic ground motions are critical for estimating the base motion of structures. The variations in site amplifications at particular periods can range over a factor of 20 or more in comparing amplitude spectra from rock and soil sites, e.g., Mexico City (1985) or San Francisco (1989). The basic phenomenon of nonlinear soil response, and by inference severe attenuation of seismic waves, has rarely been measured although it is commonly observed in laboratory experiments. The basic question is whether or not the local site geology amplifies are attenuates the seismic ground motion. Because the answer depends on the interaction between the local site geology and the amplitude as well as the frequency content of the incoming seismic waves, the in situ measurements must sample the depth variations of the local structure as well as record seismic waves over as wide a range as possible in amplitude and frequency

Insulated pipe clamp design

International Nuclear Information System (INIS)

Anderson, M.J.; Hyde, L.L.; Wagner, S.E.; Severud, L.K.

1980-01-01

Thin wall large diameter piping for breeder reactor plants can be subjected to significant thermal shocks during reactor scrams and other upset events. On the Fast Flux Test Facility, the addition of thick clamps directly on the piping was undesired because the differential metal temperatures between the pipe wall and the clamp could have significantly reduced the pipe thermal fatigue life cycle capabilities. Accordingly, an insulated pipe clamp design concept was developed. 5 refs

Theoretical and experimental nonlinear dynamics of a clamped-clamped beam MEMS resonator

NARCIS (Netherlands)

Mestrom, R.M.C.; Fey, R.H.B.; Nijmeijer, H.

2008-01-01

Microelectromechanical resonators feature nonlineardynamic responses. A first-principles based modeling approach is proposed for a clamped-clamped beam resonator. Starting from the partial differential equation for the beam including geometric and electrostatic nonlinear effects, a reduced-order

Is it cement to be? Downhole cement that uses zeolite additive may offer lightweight alternative

Energy Technology Data Exchange (ETDEWEB)

Mahoney, J.

2001-05-01

C2C Zeolite Corporation produces zeolites from a large deposit near Cache Creek, British Columbia, and processes them for use as an additive in downhole cement well casings. Early research indicates that zeolites can significantly improve the way downhole cement is made in the oil industry. Zeolites are made up mostly of silicates of aluminum and calcium. They have a great ability to absorb water, resulting in a lighter and more fluid cement than is currently available. C2C claims that zeolites will reduce cement weight, column pressure and operator costs. The cost benefits of using lighter cement downhole includes easier moving, processing and handling of the mix. Initial research suggests that zeolites might prove to be viable alternatives to other cement lighteners such as silica fumes or flyash. Zeolite-based cement also performed reasonably well in freeze-thaw tests and showed good adhesion and no evidence of shrinkage in downhole tests. 3 figs.

Summary: High Temperature Downhole Motor

Energy Technology Data Exchange (ETDEWEB)

Raymond, David W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-10-01

Directional drilling can be used to enable multi-lateral completions from a single well pad to improve well productivity and decrease environmental impact. Downhole rotation is typically developed with a motor in the Bottom Hole Assembly (BHA) that develops drilling power (speed and torque) necessary to drive rock reduction mechanisms (i.e., the bit) apart from the rotation developed by the surface rig. Historically, wellbore deviation has been introduced by a “bent-sub,” located in the BHA, that introduces a small angular deviation, typically less than 3 degrees, to allow the bit to drill off-axis with orientation of the BHA controlled at the surface. The development of a high temperature downhole motor would allow reliable use of bent subs for geothermal directional drilling. Sandia National Laboratories is pursuing the development of a high temperature motor that will operate on either drilling fluid (water-based mud) or compressed air to enable drilling high temperature, high strength, fractured rock. The project consists of designing a power section based upon geothermal drilling requirements; modeling and analysis of potential solutions; and design, development and testing of prototype hardware to validate the concept. Drilling costs contribute substantially to geothermal electricity production costs. The present development will result in more reliable access to deep, hot geothermal resources and allow preferential wellbore trajectories to be achieved. This will enable development of geothermal wells with multi-lateral completions resulting in improved geothermal resource recovery, decreased environmental impact and enhanced well construction economics.

Subsurface multidisciplinary research results at ICTJA-CSIC downhole lab and test site

Science.gov (United States)

Jurado, Maria Jose; Crespo, Jose; Salvany, Josep Maria; Teixidó, Teresa

2017-04-01

Two scientific boreholes, Almera-1 and Almera-2 were drilled in the Barcelona University campus area in 2011. The main purpose for this drilling was to create a new geophysical logging and downhole monitoring research facility and infrastructure. We present results obtained in the frame of multidisciplinary studies and experiments carried out since 2011 at the ICTJA "Borehole Geophysical Logging Lab - Scientific Boreholes Almera" downhole lab facilities. First results obtained from the scientific drilling, coring and logging allowed us to characterize the urban subsurface geology and hydrology adjacent to the Institute of Earth Sciences Jaume Almera (ICTJA-CSIC) in Barcelona. The subsurface geology and structural picture has been completed with recent geophysical studies and monitoring results. The upper section of Almera-1 214m deep hole was cased with PVC after drilling and after the logging operations. An open hole interval was left from 112m to TD (Paleozoic section). Almera-2 drilling reached 46m and was cased also with PVC to 44m. Since completion of the drilling in 2011, both Almera-1 and Almera-2 have been extensively used for research purposes, tests, training, hydrological and geophysical monitoring. A complete set of geophysical logging measurements and borehole oriented images were acquired in open hole mode of the entire Almera-1 section. Open hole measurements included acoustic and optical imaging, spectral natural gamma ray, full wave acoustic logging, magnetic susceptibility, hydrochemical-temperature logs and fluid sampling. Through casing (PVC casing) measurements included spectral gamma ray logging, full wave sonic and acoustic televiewer. A Quaternary to Paleozoic section was characterized based on the geophysical logging and borehole images interpretation and also on the complete set of (wireline) cores of the entire section. Sample availability was intended for geological macro and micro-facies detailed characterization, mineralogical and

Geophysical Monitoring at the CO2SINK Site: Combining Seismic and Geoelectric Data

Science.gov (United States)

Giese, R.; Lüth, S.; Cosma, C.; Juhlin, C.; Kiessling, D.; Schütt, H.; Schöbel, B.; Schmidt-Hattenberger, C.; Schilling, F.; Co2SINK Group

2009-04-01

The CO2SINK project at the German town of Ketzin (near Berlin), is aimed at a pilot storage of CO2, and at developing and testing efficient integrated monitoring procedures (physical, chemical, and biological observations) for assessing the processes triggered within the reservoir by a long term injection operation. In particular, geophysical methods as seismic and geoelectric measurements have delivered the structural framework, and they enable to observe the reaction of the reservoir and the caprock to CO2 propagation at locations which are not accessible for direct observations. We report on the seismic monitoring program of the CO2SINK project which comprises baseline and repeat observations at different scales in time and space, combined with comprehensive geoelectrical monitoring performed in the Ketzin wells and on the surface. The main objectives of the 3D seismic survey (carried out in spring 2005) were to provide the structural model around the location of the Ketzin wells, to verify earlier geologic interpretations of structure based on vintage 2D seismic and borehole data, as well as providing a baseline for future seismic surveys. The uppermost 1000 m are well imaged and show an anticlinal structure with an east-west striking central graben on its top. The 3D baseline survey was extended by VSP (vertical seismic profiling), MSP (moving source profiling) on 7 profiles, and crosshole tomographic measurements. 2D "star" measurements were carried out on the 7 MSP profiles in order to tie-in the down-hole surveys with the 3D baseline survey. These measurements provide enhanced resolution in time (faster and more cost effective than a full 3D survey) and space (higher source and receiver frequencies). Three crosshole measurements were performed, one baseline survey in May 2008, and two repeats in July and August 2008, respectively. A third crosshole repeat is planned for a later stage in the project when a steady state situation has been reached in the

Loading dynamics of a sliding DNA clamp.

KAUST Repository

Cho, Won-Ki

2014-05-22

Sliding DNA clamps are loaded at a ss/dsDNA junction by a clamp loader that depends on ATP binding for clamp opening. Sequential ATP hydrolysis results in closure of the clamp so that it completely encircles and diffuses on dsDNA. We followed events during loading of an E. coli β clamp in real time by using single-molecule FRET (smFRET). Three successive FRET states were retained for 0.3 s, 0.7 s, and 9 min: Hydrolysis of the first ATP molecule by the γ clamp loader resulted in closure of the clamp in 0.3 s, and after 0.7 s in the closed conformation, the clamp was released to diffuse on the dsDNA for at least 9 min. An additional single-molecule polarization study revealed that the interfacial domain of the clamp rotated in plane by approximately 8° during clamp closure. The single-molecule polarization and FRET studies thus revealed the real-time dynamics of the ATP-hydrolysis-dependent 3D conformational change of the β clamp during loading at a ss/dsDNA junction.

Feasibility of using electrical downhole heaters in Faja heavy oil reservoirs

Energy Technology Data Exchange (ETDEWEB)

Rodriguez, R.; Bashbush, J.L.; Rincon, A. [Society of Petroleum Engineers, Richardson, TX (United States)]|[Schlumberger, Sugar Land, TX (United States)

2008-10-15

Numerical models were used to examine the effect of downhole heaters in enhanced oil recovery (EOR) processes in Venezuela's Orinoco reservoir. The downhole heaters were equipped with mineral-insulated cables that allowed alternating currents to flow between 2 conductors packed in a resistive core composed of polymers and graphite. The heaters were used in conjunction with steam assisted gravity drainage (SAGD) processes and also used in horizontal wells for limited amounts of time in order to accelerate production and pressure declines. The models incorporated the petrophysical and fluid characteristics of the Ayacucho area in the Faja del Orinoco. A compositional-thermal simulator was used to describe heat and fluid flow within the reservoir. A total of 8 scenarios were used to examine the electrical heaters with horizontal and vertical wells with heaters of various capacities. Results of the study were then used in an economic analysis of capitalized and operating costs. Results of the study showed that downhole heaters are an economically feasible EOR option for both vertical and horizontal wells. Use of the heaters prior to SAGD processes accelerated production and achieved higher operational efficiencies. 5 refs., 9 tabs., 15 figs.

Seismic response and damping tests of small bore LMFBR piping and supports

International Nuclear Information System (INIS)

Barta, D.A.; Anderson, M.J.; Severud, L.K.; Lindquist, M.R.

1984-01-01

Seismic testing and analysis of a prototypical Liquid Metal Fast Breeder Reactor (LMFBR) small bore piping system is described. Measured responses to simulated seismic excitations are compared with analytical predictions based on NRC Regulatory Guide 1.61 and measured system damping values. The test specimen was representative of a typical LMFBR insulated small bore piping system, and it was supported from a rigid test frame by prototypic dead weight supports, mechanical snubbers and pipe clamps

Delay Pressure Detection Method to Eliminate Pump Pressure Interference on the Downhole Mud Pressure Signals

Directory of Open Access Journals (Sweden)

Yue Shen

2013-01-01

Full Text Available The feasibility of applying delay pressure detection method to eliminate mud pump pressure interference on the downhole mud pressure signals is studied. Two pressure sensors mounted on the mud pipe in some distance apart are provided to detect the downhole mud continuous pressure wave signals on the surface according to the delayed time produced by mud pressure wave transmitting between the two sensors. A mathematical model of delay pressure detection is built by analysis of transmission path between mud pump pressure interference and downhole mud pressure signals. Considering pressure signal transmission characteristics of the mud pipe, a mathematical model of ideal low-pass filter for limited frequency band signal is introduced to study the pole frequency impact on the signal reconstruction and the constraints of pressure sensor distance are obtained by pole frequencies analysis. Theoretical calculation and numerical simulation show that the method can effectively eliminate mud pump pressure interference and the downhole mud continuous pressure wave signals can be reconstructed successfully with a significant improvement in signal-to-noise ratio (SNR in the condition of satisfying the constraints of pressure sensor distance.

Report covering examination of parts from downhole steam generators. [Combustor head and sleeve parts

Energy Technology Data Exchange (ETDEWEB)

Pettit, F. S.; Meier, G. H.

1983-08-01

Combustor head and sleeve parts were examined by using optical and scanning electron metallography after use in oxygen/diesel and air/diesel downhole steam generators. The degradation of the different alloy components is described in terms of reactions with oxygen, sulfur and carbon in the presence of cyclic stresses, all generated by the combustion process. Recommendations are presented for component materials (alloys and coatings) to extend component lives in the downhole steam generators. 9 references, 22 figures, 3 tables.

Pipe clamp effects on thin-walled pipe design

International Nuclear Information System (INIS)

Lindquist, M.R.

1980-01-01

Clamp induced stresses in FFTF piping are sufficiently large to require structural assessment. The basic principles and procedures used in analyzing FFTF piping at clamp support locations for compliance with ASME Code rules are given. Typical results from a three-dimensional shell finite element pipe model with clamp loads applied over the clamp/pipe contact area are shown. Analyses performed to categorize clamp induced piping loads as primary or secondary in nature are described. The ELCLAMP Computer Code, which performs analyses at clamp locations combining clamp induced stresses with stresses from overall piping system loads, is discussed. Grouping and enveloping methods to reduce the number of individual clamp locations requiring analysis are described

Multifrequency Excitation of a Clamped-Clamped Microbeam

KAUST Repository

Jaber, Nizar R.

2016-01-20

We present analytical and experimental investigation of an electrically actuated clamped-clamped microbeam under a twosource harmonic excitation. The first frequency is swept around the first mode of vibration where the second one is fixed. These microbeams are fabricated using polyimide as structural layer coated with nickel form top and chromium and gold layers from bottom. We demonstrate the excitation of additive and subtractive type resonance. We show that by properly tuning the frequency and the amplitude of the excitation force, the frequency bandwidth of the resonator is increased. Theoretically, we solved the eigenvalue problem for different axial forces to find the natural frequencies ratio that match the experimental values. Using Galerkin method, a reduced order model is derived to simulate the static and dynamic response of the device where using three symmetric mode shapes provided a good agreement with experimental data. © Copyright 2015 by ASME.

An improved fiber optic pressure and temperature sensor for downhole application

International Nuclear Information System (INIS)

Aref, S H; Zibaii, M I; Latifi, H

2009-01-01

We report on the fabrication of a high pressure extrinsic Fabry–Perot interferometric (EFPI) fiber optic sensor for downhole applications by using a mechanical transducer. The mechanical transducer has been used for increasing the pressure sensitivity and the possibility of installation of the sensor downhole. The pressure–temperature cross-sensitivity (PTCS) problem has been solved by replacing the reflecting fiber with a metal microwire in the EFPI sensor. In this way the PTCS coefficient of the sensor was decreased from 47.25 psi °C −1 to 7 psi °C −1 . By using a new EFPI design, a temperature sensor was fabricated. Further improvement in the pressure and temperature sensor has been done by developing fabrication technique and signal processing

Numerical Study of Water Control with Downhole Oil-Water Separation Technology

Directory of Open Access Journals (Sweden)

Yin Khor Yin

2014-07-01

Full Text Available The maturing oil fields with increasing water production can pose a challenging produced water handling and disposal issues. This paper presents a numerical study of a motorless hydrocyclone to enhance understanding of the downhole oil-water separation. The turbulence of fluid flow is obtained using K-ε Realizable Turbulence model for complex swirl dominated flow, while the interface between hydrocarbon and water is described using the Discrete Phase model. In this approach, factors which contribute to the hydrocyclone separation instability were discussed. Discussion is then extended to the relationship of residence time with pressure difference between overflow and underflow. These pressure differences are able to relate to pressure condition for high water cut well which require downhole separation.

Seismic VSP Investigations at Olkiluoto, 2005

Energy Technology Data Exchange (ETDEWEB)

Enescu, N.; Cosma, C.; Balu, L. (Vibrometric, Vantaa (Finland))

2007-08-15

Posiva Oy carries out R and D related tasks for spent nuclear fuel disposal in Finland. The site characterization has been conducted since 1987 in Olkiluoto in western Finland. The ONKALO underground characterization facility has been under construction since 2004. Vibrometric Oy has been contracted to carry out seismic VSP survey in four drillholes in the immediate vicinity of ONKALO, for the characterization of the seismically responsive structures. Four drillholes, KR8, KR27, KR29 and KR38 were included to the project. Seven seismic source locations on ground surface were used for each drillhole. The source locations were optimized with respect to the drillhole and ONKALO and were configured as linear arrays to produce optimum imaging focused on the ONKALO volume. A mechanical Vibsist source, using a hydraulic rock breaker mounted on a 22 t excavator, was used as source of seismic signal. The signal was recorded with downhole 3-component geophones. The recording array was 8-level long, with 5 m spacing between levels. Acquisition was run throughout the drillholes. Processing of the VSP profiles consisted of time decoding of the impact sequences, filtering and image point (IP) transform. The interpretation was carried out interactively, seeking for best match of orientation of each reflection according to different borehole profiles where the features were seen. The interpretations were built as an add-on to a previous seismic model of the site. The most distinct reflectors were interpreted, compiled to as a part of a terrain model composed of 3D surfaces, and transferred digitally together with other results (3D elements of reflector locations) into Posiva's 3D modeling system. Some of the reflectors have already received direct confirmation from ONKALO observations. (orig.)

Seismic VSP Investigations at Olkiluoto, 2005

International Nuclear Information System (INIS)

Enescu, N.; Cosma, C.; Balu, L.

2007-08-01

Posiva Oy carries out R and D related tasks for spent nuclear fuel disposal in Finland. The site characterization has been conducted since 1987 in Olkiluoto in western Finland. The ONKALO underground characterization facility has been under construction since 2004. Vibrometric Oy has been contracted to carry out seismic VSP survey in four drillholes in the immediate vicinity of ONKALO, for the characterization of the seismically responsive structures. Four drillholes, KR8, KR27, KR29 and KR38 were included to the project. Seven seismic source locations on ground surface were used for each drillhole. The source locations were optimized with respect to the drillhole and ONKALO and were configured as linear arrays to produce optimum imaging focused on the ONKALO volume. A mechanical Vibsist source, using a hydraulic rock breaker mounted on a 22 t excavator, was used as source of seismic signal. The signal was recorded with downhole 3-component geophones. The recording array was 8-level long, with 5 m spacing between levels. Acquisition was run throughout the drillholes. Processing of the VSP profiles consisted of time decoding of the impact sequences, filtering and image point (IP) transform. The interpretation was carried out interactively, seeking for best match of orientation of each reflection according to different borehole profiles where the features were seen. The interpretations were built as an add-on to a previous seismic model of the site. The most distinct reflectors were interpreted, compiled to as a part of a terrain model composed of 3D surfaces, and transferred digitally together with other results (3D elements of reflector locations) into Posiva's 3D modeling system. Some of the reflectors have already received direct confirmation from ONKALO observations. (orig.)

Downhole multiphase metering in wells by means of soft-sensing

NARCIS (Netherlands)

Leskens, M.; Kruif, B. de; Belfroid, S.P.C.; Smeulers, J.P.M.; Gryzlov, A.

2008-01-01

Multiphase flow meters are indispensable tools for achieving optimal operation and control of wells as these meters deliver real-time information about their performance. For example, multiphase flow meters located downhole can improve the production of multilateral and multizone wells by timely

Active cooling for downhole instrumentation: Preliminary analysis and system selection

Energy Technology Data Exchange (ETDEWEB)

Bennett, G.A.

1988-03-01

A feasibility study and a series of preliminary designs and analyses were done to identify candidate processes or cycles for use in active cooling systems for downhole electronic instruments. A matrix of energy types and their possible combinations was developed and the energy conversion process for each pari was identified. The feasibility study revealed conventional as well as unconventional processes and possible refrigerants and identified parameters needing further clarifications. A conceptual design or series od oesigns for each system was formulated and a preliminary analysis of each design was completed. The resulting coefficient of performance for each system was compared with the Carnot COP and all systems were ranked by decreasing COP. The system showing the best combination of COP, exchangeability to other operating conditions, failure mode, and system serviceability is chosen for use as a downhole refrigerator. 85 refs., 48 figs., 33 tabs.

Research on Overflow Monitoring Mechanism Based on Downhole Microflow Detection

Directory of Open Access Journals (Sweden)

Liang Ge

2014-01-01

Full Text Available The flow rate variation of the drilling fluid and micro-overflow loss is difficult to analyze. The purpose to prevent the occurrence of kick, lost circulation, and other complex conditions is not easy to be achieved. Therefore, the microflow-induced annulus multiphase flow rate and annulus pressure field model were studied, and a downhole microflow measurement system has been developed. A differential pressure type flow measurement was used in the system, and real-time downhole information was obtained to achieve deep, narrow windows and other safety-density complex formation security. This paper introduced a new bottom-hole flow meter which can measure the annular flux while drilling and monitor overflow and circulation loss. The accuracy and reliability of the MPD (managed pressure drilling system can be improved obviously by applying the device; as a result, the safety of drilling is enhanced and the cost is reduced.

Mechanical Design of Downhole Tractor Based on Two-Way Self-locking Mechanism

Science.gov (United States)

Fang, Delei; Shang, Jianzhong; Luo, Zirong; Wu, Guoheng; Liu, Yiying

2018-03-01

Based on the technology of horizontal well tractor, a kind of downhole tractor was developed which can realize Two-Way self-locking function. Aiming at the needs of horizontal well logging to realize the target of small size, high traction and high reliability, the tractor selects unique heart-shaped CAM as the locking mechanism. The motion principle of telescopic downhole tractor, the design of mechanical structure and locking principle of the locking mechanism are all analyzed. The mathematical expressions of traction are obtained by mechanical analysis of parallel support rod in the locking mechanism. The force analysis and contour design of the heart-shaped CAM are performed, which can lay the foundation for the development of tractor prototype.

Analysis list: Clamp [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available Clamp Cell line + dm3 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/Clamp.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/Clam...p.5.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/Clam...p.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/colo/Clamp.Cell_line.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/colo/Cell_line.gml ...

A Monte Carlo approach to constraining uncertainties in modelled downhole gravity gradiometry applications

Science.gov (United States)

Matthews, Samuel J.; O'Neill, Craig; Lackie, Mark A.

2017-06-01

Gravity gradiometry has a long legacy, with airborne/marine applications as well as surface applications receiving renewed recent interest. Recent instrumental advances has led to the emergence of downhole gravity gradiometry applications that have the potential for greater resolving power than borehole gravity alone. This has promise in both the petroleum and geosequestration industries; however, the effect of inherent uncertainties in the ability of downhole gravity gradiometry to resolve a subsurface signal is unknown. Here, we utilise the open source modelling package, Fatiando a Terra, to model both the gravity and gravity gradiometry responses of a subsurface body. We use a Monte Carlo approach to vary the geological structure and reference densities of the model within preset distributions. We then perform 100 000 simulations to constrain the mean response of the buried body as well as uncertainties in these results. We varied our modelled borehole to be either centred on the anomaly, adjacent to the anomaly (in the x-direction), and 2500 m distant to the anomaly (also in the x-direction). We demonstrate that gravity gradiometry is able to resolve a reservoir-scale modelled subsurface density variation up to 2500 m away, and that certain gravity gradient components (Gzz, Gxz, and Gxx) are particularly sensitive to this variation in gravity/gradiometry above the level of uncertainty in the model. The responses provided by downhole gravity gradiometry modelling clearly demonstrate a technique that can be utilised in determining a buried density contrast, which will be of particular use in the emerging industry of CO2 geosequestration. The results also provide a strong benchmark for the development of newly emerging prototype downhole gravity gradiometers.

An Overview of Downhole Imaging Tools

Science.gov (United States)

Luthi, S. M.

In this presentation we give an overview of downhole imaging tools that can be used to image the borehole wall and its vicinity with a variety of physical methods. Among these are ultrasonic scans with a rotating transducer that performs a pulse-echo mea- surement in rapid succession. This gives a transit time and a reflected amplitude image of the borehole wall. Electrical imaging is done with a whole family of measurements that operate mostly in the low AC range. All of them feature a number of electrodes that is inversely proportional to the desired resolution and depth of investigation. They image layering, fracturing and other heterogeneities in the rocks traversed by the bore- hole. Some of these images can be recorded and transmitted to the surface in real-time while the well is being drilled. Imaging using nuclear methods is also possible, for ex- ample for the natural radioactivity, density, or neutron porosity of the rock. However, these devices have generally low spatial resolutions. Finally, optical imaging is pos- sible in translucent and slightly opaque muds with a downhole video camera. Recent developments have resulted in a device that can withstand high pressures and temper- atures and that transmits live video images to the surface in real-time. This method has the highest resolution but is of limited applicability in the oil industry where gener- ally opaque muds are used. These images can be successfully used to determined the structural and intrinsic properties of rock traversed by a borehole.

Cell-Detection Technique for Automated Patch Clamping

Science.gov (United States)

McDowell, Mark; Gray, Elizabeth

2008-01-01

A unique and customizable machinevision and image-data-processing technique has been developed for use in automated identification of cells that are optimal for patch clamping. [Patch clamping (in which patch electrodes are pressed against cell membranes) is an electrophysiological technique widely applied for the study of ion channels, and of membrane proteins that regulate the flow of ions across the membranes. Patch clamping is used in many biological research fields such as neurobiology, pharmacology, and molecular biology.] While there exist several hardware techniques for automated patch clamping of cells, very few of those techniques incorporate machine vision for locating cells that are ideal subjects for patch clamping. In contrast, the present technique is embodied in a machine-vision algorithm that, in practical application, enables the user to identify good and bad cells for patch clamping in an image captured by a charge-coupled-device (CCD) camera attached to a microscope, within a processing time of one second. Hence, the present technique can save time, thereby increasing efficiency and reducing cost. The present technique involves the utilization of cell-feature metrics to accurately make decisions on the degree to which individual cells are "good" or "bad" candidates for patch clamping. These metrics include position coordinates (x,y) in the image plane, major-axis length, minor-axis length, area, elongation, roundness, smoothness, angle of orientation, and degree of inclusion in the field of view. The present technique does not require any special hardware beyond commercially available, off-the-shelf patch-clamping hardware: A standard patchclamping microscope system with an attached CCD camera, a personal computer with an imagedata- processing board, and some experience in utilizing imagedata- processing software are all that are needed. A cell image is first captured by the microscope CCD camera and image-data-processing board, then the image

High power laser downhole cutting tools and systems

Science.gov (United States)

Zediker, Mark S; Rinzler, Charles C; Faircloth, Brian O; Koblick, Yeshaya; Moxley, Joel F

2015-01-20

Downhole cutting systems, devices and methods for utilizing 10 kW or more laser energy transmitted deep into the earth with the suppression of associated nonlinear phenomena. Systems and devices for the laser cutting operations within a borehole in the earth. These systems and devices can deliver high power laser energy down a deep borehole, while maintaining the high power to perform cutting operations in such boreholes deep within the earth.

Multilevel-clamped multilevel converters (MLC²)

DEFF Research Database (Denmark)

Rodriguez, Pedro; Bellar, Maria Dias; Muñoz-Aguliar, Raúl Santiago

2012-01-01

clamping scheme is the ML clamping cell, which is composed of a pair of dc sources associated with one single-pole/triple-throw type of switch arrangement. The number of series-connected ML-clamping cells will set the number of levels of the synthesized waveform. By depending on the MCU arrangements......, different converter configurations can be derived, namely, the common clamping and the modular types. Both approaches can be accomplished by employing classical three-level neutral-point-clamped (NPC) technology. Thus, the overall structure of the resultant converter is kept simple, wherein the number...

Investigation of permanent magnet machines for downhole applications: Design, prototype and testing of a flux-switching permanent magnet machine

Energy Technology Data Exchange (ETDEWEB)

Chen, Anyuan

2011-01-15

The current standard electrical downhole machine is the induction machine which is relatively inefficient. Permanent magnet (PM) machines, having higher efficiencies, higher torque densities and smaller volumes, have widely employed in industrial applications to replace conventional machines, but few have been developed for downhole applications due to the high ambient temperatures in deep wells and the low temperature stability of PM materials over time. Today, with the development of variable speed drives and the applications of high temperature magnet materials, it is increasingly interesting for oil and gas industries to develop PM machines for downhole applications. Recently, some PM machines applications have been presented for downhole applications, which are normally addressed on certain specific downhole case. In this thesis the focus has been put on the performance investigation of different PM machines for general downhole cases, in which the machine outer diameter is limited to be small by well size, while the machine axial length may be relatively long. The machine reliability is the most critical requirement while high torque density and high efficiency are also desirable. The purpose is to understand how the special constraints in downhole condition affect the performances of different machines. First of all, three basic machine concepts, which are the radial, axial and transverse flux machines, are studied in details by analytical method. Their torque density, efficiency, power factor and power capability are investigated with respect to the machine axial length and pole number. The presented critical performance comparisons of the machines provide an indication of machines best suitable with respect to performance and size for downhole applications. Conventional radial flux permanent magnet (RFPM) machines with the PMs on the rotor can provide high torque density and high efficiency. This type of machine has been suggested for several different

Cavola experiment site: geophysical investigations and deployment of a dense seismic array on a landslide

Directory of Open Access Journals (Sweden)

L. Martelli

2007-06-01

Full Text Available Geophysical site investigations have been performed in association with deployment of a dense array of 95 3-component seismometers on the Cavola landslide in the Northern Apennines. The aim of the array is to study propagation of seismic waves in the heterogeneous medium through comparison of observation and modelling. The small-aperture array (130 m×56 m operated continuously for three months in 2004. Cavola landslide consists of a clay body sliding over mudstone-shale basement, and has a record of historical activity, including destruction of a small village in 1960. The site investigations include down-hole logging of P- and S-wave travel times at a new borehole drilled within the array, two seismic refraction lines with both P-wave profiling and surface-wave analyses, geo-electrical profiles and seismic noise measurements. From the different approaches a consistent picture of the depths and seismic velocities for the landslide has emerged. Their estimates agree with resonance frequencies of seismic noise, and also with the logged depths to basement of 25 m at a new borehole and of 44 m at a pre-existing borehole. Velocities for S waves increase with depth, from 230 m/s at the surface to 625 m/s in basement immediately below the landslide.

Development of a novel vortex flow meter for downhole use

NARCIS (Netherlands)

Schiferli, W.; Cheng, L.K.

2008-01-01

Due to the increasing complexity of oil and gas wells, the demand for instrumentation to measure conditions inside well tubing below the surface is growing rapidly. A robust meter was designed to measure liquid flows at downhole conditions. The meter is based on a specially-designed bluff body to

Analysis of the Pallet Clamping Conditions in Work Positioning

Directory of Open Access Journals (Sweden)

L. A. Kolesnikov

2016-01-01

Full Text Available Pallets of automatic transfer lines serve as the technological and work-transfer equipment. However, their design is based on the general principles of designing machine accessories. Calculation of the basic design parameters of work based on their functioning features is fairly relevant.In pallet transfer movement over work positioning there is a mismatch between axes of the basic bushing of a pallet and the clamping locks of positioning. The paper identifies the factors influencing it, and defines the conditions to ensure the trouble-free clamping lock. The circular and rhombic clamping of pallet is simultaneous. Further, a clamping load is calculated from the pallet mass (together with the work-piece and the geometric parameters of the pallet clamping.The paper reveals three movement stages of the clamping lock in a vertical plane when setting the pallet in work positioning:- a clamping lock free play till it encounters with the location bushing;- a clamping lock play length when the lead-in chamfer contacts the bushing chamfer;- a clamping lock play length over the circular surface of bushing.The study of this process has allowed us to calculate the time of pallet clamping and dynamic loads acting on the clamping lock. These calculations made it possible to calculate the required diameter of the clamping lock. The presented calculations allow a reasonable assigning the main design parameters of work positioning for the pallet automatic lines.

Real-time seismic monitoring of the integrated cape girardeau bridge array and recorded earthquake response

Science.gov (United States)

Celebi, M.

2006-01-01

This paper introduces the state of the art, real-time and broad-band seismic monitoring network implemented for the 1206 m [3956 ft] long, cable-stayed Bill Emerson Memorial Bridge in Cape Girardeau (MO), a new Mississippi River crossing, approximately 80 km from the epicentral region of the 1811-1812 New Madrid earthquakes. The bridge was designed for a strong earthquake (magnitude 7.5 or greater) during the design life of the bridge. The monitoring network comprises a total of 84 channels of accelerometers deployed on the superstructure, pier foundations and at surface and downhole free-field arrays of the bridge. The paper also presents the high quality response data obtained from the network. Such data is aimed to be used by the owner, researchers and engineers to assess the performance of the bridge, to check design parameters, including the comparison of dynamic characteristics with actual response, and to better design future similar bridges. Preliminary analyses of ambient and low amplitude small earthquake data reveal specific response characteristics of the bridge and the free-field. There is evidence of coherent tower, cable, deck interaction that sometimes results in amplified ambient motions. Motions at the lowest tri-axial downhole accelerometers on both MO and IL sides are practically free from any feedback from the bridge. Motions at the mid-level and surface downhole accelerometers are influenced significantly by feedback due to amplified ambient motions of the bridge. Copyright ASCE 2006.

Field test of two high-pressure, direct-contact downhole steam generators. Volume I. Air/diesel system

Energy Technology Data Exchange (ETDEWEB)

Marshall, B.W.

1983-05-01

As a part of the Project DEEP STEAM to develop technology to more efficiently utilize steam for the recovery of heavy oil from deep reservoirs, a field test of a downhole steam generator (DSG) was performed. The DSG burned No. 2 diesel fuel in air and was a direct-contact, high pressure device which mixed the steam with the combustion products and injected the resulting mixture directly into the oil reservoir. The objectives of the test program included demonstration of long-term operation of a DSG, development of operational methods, assessment of the effects of the steam/combustion gases on the reservoir and comparison of this air/diesel DSG with an adjacent oxygen/diesel direct contact generator. Downhole operation of the air/diesel DSG was started in June 1981 and was terminated in late February 1982. During this period two units were placed downhole with the first operating for about 20 days. It was removed, the support systems were slightly modified, and the second one was operated for 106 days. During this latter interval the generator operated for 70% of the time with surface air compressor problems the primary source of the down time. Thermal contact, as evidenced by a temperature increase in the production well casing gases, and an oil production increase were measured in one of the four wells in the air/diesel pattern. Reservoir scrubbing of carbon monoxide was observed, but no conclusive data on scrubbing of SO/sub x/ and NO/sub x/ were obtained. Corrosion of the DSG combustor walls and some other parts of the downhole package were noted. Metallurgical studies have been completed and recommendations made for other materials that are expected to better withstand the downhole combustion environment. 39 figures, 8 tables.

Ventilation onset prior to umbilical cord clamping (physiological-based cord clamping improves systemic and cerebral oxygenation in preterm lambs.

Directory of Open Access Journals (Sweden)

Graeme R Polglase

Full Text Available As measurement of arterial oxygen saturation (SpO2 is common in the delivery room, target SpO2 ranges allow clinicians to titrate oxygen therapy for preterm infants in order to achieve saturation levels similar to those seen in normal term infants in the first minutes of life. However, the influence of the onset of ventilation and the timing of cord clamping on systemic and cerebral oxygenation is not known.We investigated whether the initiation of ventilation, prior to, or after umbilical cord clamping, altered systemic and cerebral oxygenation in preterm lambs.Systemic and cerebral blood-flows, pressures and peripheral SpO2 and regional cerebral tissue oxygenation (SctO2 were measured continuously in apnoeic preterm lambs (126±1 day gestation. Positive pressure ventilation was initiated either 1 prior to umbilical cord clamping, or 2 after umbilical cord clamping. Lambs were monitored intensively prior to intervention, and for 10 minutes following umbilical cord clamping.Clamping the umbilical cord prior to ventilation resulted in a rapid decrease in SpO2 and SctO2, and an increase in arterial pressure, cerebral blood flow and cerebral oxygen extraction. Ventilation restored oxygenation and haemodynamics by 5-6 minutes. No such disturbances in peripheral or cerebral oxygenation and haemodynamics were observed when ventilation was initiated prior to cord clamping.The establishment of ventilation prior to umbilical cord clamping facilitated a smooth transition to systemic and cerebral oxygenation following birth. SpO2 nomograms may need to be re-evaluated to reflect physiological management of preterm infants in the delivery room.

Piezoresistive cantilever force-clamp system

Energy Technology Data Exchange (ETDEWEB)

Park, Sung-Jin; Petzold, Bryan C.; Pruitt, Beth L. [Department of Mechanical Engineering, Stanford University, Stanford, California 94305 (United States); Goodman, Miriam B. [Department of Molecular and Cellular Physiology, Stanford University, Stanford, California 94305 (United States)

2011-04-15

We present a microelectromechanical device-based tool, namely, a force-clamp system that sets or ''clamps'' the scaled force and can apply designed loading profiles (e.g., constant, sinusoidal) of a desired magnitude. The system implements a piezoresistive cantilever as a force sensor and the built-in capacitive sensor of a piezoelectric actuator as a displacement sensor, such that sample indentation depth can be directly calculated from the force and displacement signals. A programmable real-time controller operating at 100 kHz feedback calculates the driving voltage of the actuator. The system has two distinct modes: a force-clamp mode that controls the force applied to a sample and a displacement-clamp mode that controls the moving distance of the actuator. We demonstrate that the system has a large dynamic range (sub-nN up to tens of {mu}N force and nm up to tens of {mu}m displacement) in both air and water, and excellent dynamic response (fast response time, <2 ms and large bandwidth, 1 Hz up to 1 kHz). In addition, the system has been specifically designed to be integrated with other instruments such as a microscope with patch-clamp electronics. We demonstrate the capabilities of the system by using it to calibrate the stiffness and sensitivity of an electrostatic actuator and to measure the mechanics of a living, freely moving Caenorhabditis elegans nematode.

The cardiovascular effects of aortic clamping and unclamping

African Journals Online (AJOL)

aortic clamping is that afterload and blood pressure increase, and ... individually, albeit they interact with each other. The degree of ... position of the aortic clamp, the greater the increase ... the increase in preload in response to aortic clamping.

Geology of the Waste Treatment Plant Seismic Boreholes

Energy Technology Data Exchange (ETDEWEB)

Barnett, D. Brent; Fecht, Karl R.; Reidel, Stephen P.; Bjornstad, Bruce N.; Lanigan, David C.; Rust, Colleen F.

2007-05-11

In 2006, the U.S. Department of Energy initiated the Seismic Boreholes Project (SBP) to emplace boreholes at the Waste Treatment Plant (WTP) site in order to obtain direct shear wave velocity (Vs) measurements and other physical property measurements in Columbia River basalt and interbedded sediments of the Ellensburg Formation. The goal was to reduce the uncertainty in the response spectra and seismic design basis, and potentially recover design margin for the WTP. The characterization effort within the deep boreholes included 1) downhole measurements of the velocity properties of the suprabasalt, basalt, and sedimentary interbed sequences, 2) downhole measurements of the density of the subsurface basalt and sediments, and 3) geologic studies to confirm the geometry of the contact between the various basalt and interbedded sediments through examination of retrieved core from the core hole and data collected through geophysical logging of each borehole. This report describes the results of the geologic studies from three mud-rotary boreholes and one cored borehole at the WTP. All four boreholes penetrated the entire Saddle Mountains Basalt and the upper part of the Wanapum Basalt where thick sedimentary interbeds occur between the lava flows. The basalt flows penetrated in Saddle Mountains Basalt included the Umatilla Member, Esquatzel Member, Pomona Member, and the Elephant Mountain Member. The underlying Priest Rapids Member of the Wanapum Basalt also was penetrated. The Ellensburg Formation sediments consist of the Mabton Interbed, the Cold Creek Interbed, the Selah Interbed, and the Rattlesnake Ridge Interbed; the Byron Interbed occurs between two flows of the Priest Rapids Member. The Mabton Interbed marks the contact between the Wanapum and Saddle Mountains Basalts. The thicknesses of the basalts and interbedded sediments were within expected limits. However, a small reverse fault was found in the Pomona Member flow top. This fault has three periods of

Geology of the Waste Treatment Plant Seismic Boreholes

Energy Technology Data Exchange (ETDEWEB)

Barnett, D. BRENT; Bjornstad, Bruce N.; Fecht, Karl R.; Lanigan, David C.; Reidel, Steve; Rust, Colleen F.

2007-02-28

In 2006, DOE-ORP initiated the Seismic Boreholes Project (SBP) to emplace boreholes at the Waste Treatment Plant (WTP) site in order to obtain direct Vs measurements and other physical property measurements in Columbia River basalt and interbedded sediments of the Ellensburg Formation. The goal was to reduce the uncertainty in the response spectra and seismic design basis, and potentially recover design margin for the WTP. The characterization effort within the deep boreholes included 1) downhole measurements of the velocity properties of the suprabasalt, basalt, and sedimentary interbed sequences, 2) downhole measurements of the density of the subsurface basalt and sediments, and 3) confirmation of the geometry of the contact between the various basalt and interbedded sediments through examination of retrieved core from the corehole and data collected through geophysical logging of each borehole. This report describes the results of the geologic studies from three mud-rotary boreholes and one cored borehole at the WTP. All four boreholes penetrated the entire Saddle Mountains Basalt and the upper part of the Wanapum Basalt where thick sedimentary interbeds occur between the lava flows. The basalt flows penetrated in Saddle Mountains Basalt included the Umatilla Member, Esquatzel Member, Pomona Member and the Elephant Mountain Member. The underlying Priest Rapids Member of the Wanapum Basalt was also penetrated. The Ellensburg Formation sediments consist of the Mabton Interbed, the Cold Creek Interbed, the Selah Interbed and the Rattlesnake Ridge Interbed; the Byron Interbed occurs between two flows of the Priest Rapids Member. The Mabton Interbed marks the contact between the Wanapum and Saddle Mountains Basalts. The thicknesses of the basalts and interbedded sediments were within expected limits. However, a small reverse fault was found in the Pomona Member flow top. This fault has three periods of movement and less than 15 feet of repeated section. Most of the

Accessing SAFOD data products: Downhole measurements, physical samples and long-term monitoring

Science.gov (United States)

Weiland, C.; Zoback, M.; Hickman, S. H.; Ellsworth, W. L.

2005-12-01

Many different types of data were collected during SAFOD Phases 1 and 2 (2004-2005) as part of the National Science Foundation's EarthScope program as well as from the SAFOD Pilot Hole, drilled in 2002 and funded by the International Continental Drilling Program (ICDP). Both SAFOD and the SAFOD Pilot Hole are being conducted as a close collaboration between NSF, the U.S. Geological Survey and the ICDP. SAFOD data products include cuttings, core and fluid samples; borehole geophysical measurements; and strain, tilt, and seismic recordings from the multilevel SAFOD borehole monitoring instruments. As with all elements of EarthScope, these data (and samples) are openly available to members of the scientific and educational communities. This paper presents the acquisition, storage and distribution plan for SAFOD data products. Washed and unwashed drill cuttings and mud samples were collected during Phases 1 and 2, along with three spot cores at depths of 1.5, 2.5, and 3.1 km. A total of 52 side-wall cores were also collected in the open-hole interval between 2.5 and 3.1 km depth. The primary coring effort will occur during Phase 3 (2007), when we will continuously core up to four, 250-m-long multilaterals directly within and adjacent to the San Andreas Fault Zone. Drill cuttings, core, and fluid samples from all three Phases of SAFOD drilling are being curated under carefully controlled conditions at the Integrated Ocean Drilling Program (IODP) Gulf Coast Repository in College Station, Texas. Photos of all physical samples and a downloadable sample request form are available on the ICDP website (http://www.icdp-online.de/sites/sanandreas/index/index.html). A suite of downhole geophysical measurements was conducted during the first two Phases of SAFOD drilling, as well as during drilling of the SAFOD Pilot Hole. These data include density, resistivity, porosity, seismic and borehole image logs and are also available via the ICDP website. The SAFOD monitoring program

Development and Test of a 1,000 Level 3C Fiber Optic Borehole Seismic Receiver Array Applied to Carbon Sequestration

Energy Technology Data Exchange (ETDEWEB)

Paulsson, Bjorn N.P. [Paulsson, Inc., Van Nuys, CA (United States)

2015-02-28

To address the critical site characterization and monitoring needs for CCS programs, US Department of Energy (DOE) awarded Paulsson, Inc. in 2010 a contract to design, build and test a fiber optic based ultra-large bandwidth clamped borehole seismic vector array capable of deploying up to one thousand 3C sensor pods suitable for deployment into high temperature and high pressure boreholes. Paulsson, Inc. has completed a design or a unique borehole seismic system consisting of a novel drill pipe based deployment system that includes a hydraulic clamping mechanism for the sensor pods, a new sensor pod design and most important – a unique fiber optic seismic vector sensor with technical specifications and capabilities that far exceed the state of the art seismic sensor technologies. These novel technologies were all applied to the new borehole seismic system. In combination these technologies will allow for the deployment of up to 1,000 3C sensor pods in vertical, deviated or horizontal wells. Laboratory tests of the fiber optic seismic vector sensors developed during this project have shown that the new borehole seismic sensor technology is capable of generating outstanding high vector fidelity data with extremely large bandwidth: 0.01 – 6,000 Hz. Field tests have shown that the system can record events at magnitudes much smaller than M-2.3 at frequencies up to 2,000 Hz. The sensors have also proved to be about 100 times more sensitive than the regular coil geophones that are used in borehole seismic systems today. The fiber optic seismic sensors have furthermore been qualified to operate at temperatures over 300°C (572°F). The fibers used for the seismic sensors in the system are used to record Distributed Temperature Sensor (DTS) data allowing additional value added data to be recorded simultaneously with the seismic vector sensor data.

Design Enhancement and Performance Examination of External Rotor Switched Flux Permanent Magnet Machine for Downhole Application

Science.gov (United States)

Kumar, R.; Sulaiman, E.; Soomro, H. A.; Jusoh, L. I.; Bahrim, F. S.; Omar, M. F.

2017-08-01

The recent change in innovation and employments of high-temperature magnets, permanent magnet flux switching machine (PMFSM) has turned out to be one of the suitable contenders for seaward boring, however, less intended for downhole because of high atmospheric temperature. Subsequently, this extensive review manages the design enhancement and performance examination of external rotor PMFSM for the downhole application. Preparatory, the essential design parameters required for machine configuration are computed numerically. At that point, the design enhancement strategy is actualized through deterministic technique. At last, preliminary and refined execution of the machine is contrasted and as a consequence, the yield torque is raised from 16.39Nm to 33.57Nm while depreciating the cogging torque and PM weight up to 1.77Nm and 0.79kg, individually. In this manner, it is inferred that purposed enhanced design of 12slot-22pole with external rotor is convenient for the downhole application.

SEISMIC BEHAVIOR OF THE TOKYO BAY AREA DURING THE 2011 OFF THE PACIFIC COAST OF TOHOKU EARTHQUAKE USING DOWNHOLE ARRAY RECORDS

Science.gov (United States)

Ikeda, Takaaki; Konagai, Kazuo; Katagiri, Toshihiko

Underground motions within a hard diluvial stratum were obtained in the March 11th 2011 Great East Japan Earthquake at a downhole in the Tokyo Bay area, which has suffered serious sand-liquefaction over its long 42km2 stretch. The motions in the diluvial sand deposit are characterized by their (1) long dura-tion times with 6 to 8s components surpassing others, (2) moderate amplitude of 51.1 cm/s2 in PGA, which is estimated to have resulted in moderate average strains of 8 to 9 × 10-4 and 5 to 7 × 10-4 over shal-low -2 to -30m and deep -30 to -77m soil deposits, respectively. The peak strain reached in the interior of soil was estimated to be about 1.3 × 10-3.

21 CFR 882.4460 - Neurosurgical head holder (skull clamp).

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Neurosurgical head holder (skull clamp). 882.4460... holder (skull clamp). (a) Identification. A neurosurgical head holder (skull clamp) is a device used to clamp the patient's skull to hold head and neck in a particular position during surgical procedures. (b...

Integrated hydraulic booster/tool string technology for unfreezing of stuck downhole strings in horizontal wells

Science.gov (United States)

Tian, Q. Z.

2017-12-01

It is common to use a jarring tool to unfreeze stuck downhole string. However, in a horizontal well, influenced by the friction caused by the deviated section, jarring effect is poor; on the other hand, the forcing point can be located in the horizontal section by a hydraulic booster and the friction can be reduced, but it is time-consuming and easy to break downhole string using a large-tonnage and constant pull force. A hydraulic booster - jar tool string has been developed for unfreezing operation in horizontal wells. The technical solution involves three elements: a two-stage parallel spring cylinder structure for increasing the energy storage capacity of spring accelerators; multiple groups of spring accelerators connected in series to increase the working stroke; a hydraulic booster intensifying jarring force. The integrated unfreezing tool string based on these three elements can effectively overcome the friction caused by a deviated borehole, and thus unfreeze a stuck string with the interaction of the hydraulic booster and the mechanical jar which form an alternatively dynamic load. Experimental results show that the jarring performance parameters of the hydraulic booster-jar unfreezing tool string for the horizontal wells are in accordance with original design requirements. Then field technical parameters were developed based on numerical simulation and experimental data. Field application shows that the hydraulic booster-jar unfreezing tool string is effective to free stuck downhole tools in a horizontal well, and it reduces hook load by 80% and lessens the requirement of workover equipment. This provides a new technology to unfreeze stuck downhole string in a horizontal well.

ANZA Seismic Network- From Monitoring to Science

Science.gov (United States)

Vernon, F.; Eakin, J.; Martynov, V.; Newman, R.; Offield, G.; Hindley, A.; Astiz, L.

2007-05-01

The ANZA Seismic Network (http:eqinfo.ucsd.edu) utilizes broadband and strong motion sensors with 24-bit dataloggers combined with real-time telemetry to monitor local and regional seismicity in southernmost California. The ANZA network provides real-time data to the IRIS DMC, California Integrated Seismic Network (CISN), other regional networks, and the Advanced National Seismic System (ANSS), in addition to providing near real-time information and monitoring to the greater San Diego community. Twelve high dynamic range broadband and strong motion sensors adjacent to the San Jacinto Fault zone contribute data for earthquake source studies and continue the monitoring of the seismic activity of the San Jacinto fault initiated 24 years ago. Five additional stations are located in the San Diego region with one more station on San Clemente Island. The ANZA network uses the advance wireless networking capabilities of the NSF High Performance Wireless Research and Education Network (http:hpwren.ucsd.edu) to provide the communication infrastructure for the real-time telemetry of Anza seismic stations. The ANZA network uses the Antelope data acquisition software. The combination of high quality hardware, communications, and software allow for an annual network uptime in excess of 99.5% with a median annual station real-time data return rate of 99.3%. Approximately 90,000 events, dominantly local sources but including regional and teleseismic events, comprise the ANZA network waveform database. All waveform data and event data are managed using the Datascope relational database. The ANZA network data has been used in a variety of scientific research including detailed structure of the San Jacinto Fault Zone, earthquake source physics, spatial and temporal studies of aftershocks, array studies of teleseismic body waves, and array studies on the source of microseisms. To augment the location, detection, and high frequency observations of the seismic source spectrum from local

Mechanics of wafer bonding: Effect of clamping

Science.gov (United States)

Turner, K. T.; Thouless, M. D.; Spearing, S. M.

2004-01-01

A mechanics-based model is developed to examine the effects of clamping during wafer bonding processes. The model provides closed-form expressions that relate the initial geometry and elastic properties of the wafers to the final shape of the bonded pair and the strain energy release rate at the interface for two different clamping configurations. The results demonstrate that the curvature of bonded pairs may be controlled through the use of specific clamping arrangements during the bonding process. Furthermore, it is demonstrated that the strain energy release rate depends on the clamping configuration and that using applied loads usually leads to an undesirable increase in the strain energy release rate. The results are discussed in detail and implications for process development and bonding tool design are highlighted.

Development and Application of the Downhole Drilling String Shock-Absorption and Hydraulic Supercharging Device

Directory of Open Access Journals (Sweden)

Yongwang Liu

2016-01-01

Full Text Available It is a hot topic for deep/ultradeep wells to improve rock-breaking efficiency and drilling speed by available downhole energy. Based on different downhole energies and working conditions, specialized plunger pump is proposed to convert longitudinal vibration of drilling string into rock-breaking energy. Technical design is developed to generate high-pressure water jet. And then a simulation model is built to verify feasibility of the technical design. Through simulation, the influence law of key factors is obtained. On this basis, this device is tested in several wells. The result indicates this device can increase drilling speed as much as 136%. Meanwhile the harmful vibration can be absorbed. The energy from drilling string vibration is of high frequency and increases as well depth and formation anisotropy increase. By reducing adverse vibration, this device is able to increase the drilling speed and the service life also meets the demand of field application. The longest working time lasts for more than 130 hours. The performance of this device demonstrates great application prospect in deep/ultradeep resources exploration. To provide more equipment support for deep/ultradeep wells, more effort should be put into fundamental study on downhole drill string vibration and related equipment.

Validation of seismic soil-structure interaction analysis methods: EPRI [Electric Power Research Institute]/NRC [Nuclear Regulatory Commission] cooperation in Lotung, Taiwan, experiments

International Nuclear Information System (INIS)

Kot, C.A.; Srinivasan, M.G.; Hsieh, B.J.; Tang, Y.K.; Kassawara, R.P.

1986-01-01

The cooperative program between NRC/ANL and EPRI on the validation of soil-structure interaction analysis methods with actual seismic response data is described. A large scale-model of a containment building has been built by EPRI/Taipower in a highly seismic region of Taiwan. Vibration tests were performed, first on the basemat before the superstructure was built and then on the completed structure. Since its completion, the structure has experienced many earthquakes. The site and structural response to these earthquakes have been recorded with field (surface and downhole) and structural instrumentation. The validation program involves blind predictions of site and structural response during vibration tests and a selected seismic event, and subsequent comparison between the predictions and measurements. The predictive calculations are in progress. The results of the correlation are expected to lead to the evaluation of the methods as to their conservatisms and sensitivities

Seismic reflections associated with submarine gas hydrates

Energy Technology Data Exchange (ETDEWEB)

Andreassen, K

1996-12-31

Gas hydrates are often suggested as a future energy resource. This doctoral thesis improves the understanding of the concentration and distribution of natural submarine gas hydrates. The presence of these hydrates are commonly inferred from strong bottom simulating reflection (BSR). To investigate the nature of BSR, this work uses seismic studies of hydrate-related BSRs at two different locations, one where gas hydrates are accepted to exist and interpreted to be very extensive (in the Beaufort Sea), the other with good velocity data and downhole logs available (offshore Oregon). To ascertain the presence of free gas under the BSR, prestack offset data must supplement near-vertical incidence seismic data. A tentative model for physical properties of sediments partially saturated with gas hydrate and free gas is presented. This model, together with drilling information and seismic data containing the BSR beneath the Oregon margin and the Beaufort Sea, made it possible to better understand when to apply the amplitude-versus-offset (AVO) method to constrain BSR gas hydrate and gas models. Distribution of natural gas hydrates offshore Norway and Svalbard is discussed and interpreted as reflections from the base of gas hydrate-bearing sediments, overlying sediments containing free gas. Gas hydrates inferred to exist at the Norwegian-Svalbard continental margin correlate well with Cenozoic depocenters, and the associated gas is assumed to be mainly biogenic. Parts of that margin have a high potential for natural gas hydrates of both biogenic and thermogenic origin. 235 refs., 86 figs., 4 tabs.

Seismic reflections associated with submarine gas hydrates

Energy Technology Data Exchange (ETDEWEB)

Andreassen, K.

1995-12-31

Gas hydrates are often suggested as a future energy resource. This doctoral thesis improves the understanding of the concentration and distribution of natural submarine gas hydrates. The presence of these hydrates are commonly inferred from strong bottom simulating reflection (BSR). To investigate the nature of BSR, this work uses seismic studies of hydrate-related BSRs at two different locations, one where gas hydrates are accepted to exist and interpreted to be very extensive (in the Beaufort Sea), the other with good velocity data and downhole logs available (offshore Oregon). To ascertain the presence of free gas under the BSR, prestack offset data must supplement near-vertical incidence seismic data. A tentative model for physical properties of sediments partially saturated with gas hydrate and free gas is presented. This model, together with drilling information and seismic data containing the BSR beneath the Oregon margin and the Beaufort Sea, made it possible to better understand when to apply the amplitude-versus-offset (AVO) method to constrain BSR gas hydrate and gas models. Distribution of natural gas hydrates offshore Norway and Svalbard is discussed and interpreted as reflections from the base of gas hydrate-bearing sediments, overlying sediments containing free gas. Gas hydrates inferred to exist at the Norwegian-Svalbard continental margin correlate well with Cenozoic depocenters, and the associated gas is assumed to be mainly biogenic. Parts of that margin have a high potential for natural gas hydrates of both biogenic and thermogenic origin. 235 refs., 86 figs., 4 tabs.

Surface-downhole and crosshole geoelectrics for monitoring of brine injection at the Ketzin CO2 storage site

Science.gov (United States)

Rippe, Dennis; Bergmann, Peter; Labitzke, Tim; Wagner, Florian; Schmidt-Hattenberger, Cornelia

2016-04-01

The Ketzin pilot site in Germany is the longest operating on-shore CO2 storage site in Europe. From June 2008 till August 2013, a total of ˜67,000 tonnes of CO2 were safely stored in a saline aquifer at depths of 630 m to 650 m. The storage site has now entered the abandonment phase, and continuation of the multi-disciplinary monitoring as part of the national project "CO2 post-injection monitoring and post-closure phase at the Ketzin pilot site" (COMPLETE) provides the unique chance to participate in the conclusion of the complete life cycle of a CO2 storage site. As part of the continuous evaluation of the functionality and integrity of the CO2 storage in Ketzin, from October 12, 2015 till January 6, 2015 a total of ˜2,900 tonnes of brine were successfully injected into the CO2 reservoir, hereby simulating in time-lapse the natural backflow of brine and the associated displacement of CO2. The main objectives of this brine injection experiment include investigation of how much of the CO2 in the pore space can be displaced by brine and if this displacement of CO2 during the brine injection differs from the displacement of formation fluid during the initial CO2 injection. Geophysical monitoring of the brine injection included continuous geoelectric measurements accompanied by monitoring of pressure and temperature conditions in the injection well and two adjacent observation wells. During the previous CO2 injection, the geoelectrical monitoring concept at the Ketzin pilot site consisted of permanent crosshole measurements and non-permanent large-scale surveys (Kiessling et al., 2010). Time-lapse geoelectrical tomographies derived from the weekly crosshole data at near-wellbore scale complemented by six surface-downhole surveys at a scale of 1.5 km showed a noticeable resistivity signature within the target storage zone, which was attributed to the CO2 plume (Schmidt-Hattenberger et al., 2011) and interpreted in terms of relative CO2 and brine saturations (Bergmann

Downhole drilling hammer. Marteau de forage

Energy Technology Data Exchange (ETDEWEB)

Techy, M.

1987-07-28

This invention concerns a drilling hammer of the downhole type, comprising a tubular body fed by compressed air, a drilling cutter and a hammer piston set into movement inside an interior cylinder by a compressed air distribution mechanism alternately above and below the piston. The hammer includes a gas-oil injection device in the chamber above the piston and a mechanism for initiating the injection during the rising of the piston; the additional compression provokes the combustion of the gas-oil-air mixture, which hurls the piston towards the cutter. This type of apparatus permits an important reduction in costs of materials and of operation, and permits at the same time an increase in drilling power and a reduction in energy consumption. 8 figs.

Theoretical and experimental investigation of position-controlled semi-active friction damper for seismic structures

Science.gov (United States)

Lu, Lyan-Ywan; Lin, Tzu-Kang; Jheng, Rong-Jie; Wu, Hsin-Hsien

2018-01-01

A semi-active friction damper (SAFD) can be employed for the seismic protection of structural systems. The effectiveness of an SAFD in absorbing seismic energy is usually superior to that of its passive counterpart, since its slip force can be altered in real time according to structural response and excitation. Most existing SAFDs are controlled by adjusting the clamping force applied on the friction interface. Thus, the implementation of SAFDs in practice requires precision control of the clamping force, which is usually substantially larger than the slip force. This may increase the implementation complexity and cost of SAFDs. To avoid this problem, this study proposes a novel position-controlled SAFD, named the leverage-type controllable friction damper (LCFD). The LCFD system combines a traditional passive friction damper and a leverage mechanism with a movable central pivot. By simply controlling the pivot position, the damping force generated by the LCFD system can be adjusted in real time. In order to verify the feasibility of the proposed SAFD, a prototype LCFD was tested by using a shaking table. The test results demonstrate that the equivalent friction force and hysteresis loop of the LCFD can be regulated by controlling the pivot position. By considering 16 ground motions with two different intensities, the adaptive feature of the LCFD for seismic structural control is further demonstrated numerically.

Loading dynamics of a sliding DNA clamp.

KAUST Repository

Cho, Won-Ki; Jergic, Slobodan; Kim, Daehyung; Dixon, Nicholas E; Lee, Jong-Bong

2014-01-01

8° during clamp closure. The single-molecule polarization and FRET studies thus revealed the real-time dynamics of the ATP-hydrolysis-dependent 3D conformational change of the β clamp during loading at a ss/dsDNA junction.

Downhole microseismic monitoring of shale deposits: Case study from Northern Poland

Czech Academy of Sciences Publication Activity Database

Swiech, E.; Wandycz, P.; Eisner, Leo; Pasternacki, A.; Mackowski, T.

2017-01-01

Roč. 14, č. 3 (2017), s. 297-304 ISSN 1214-9705 Grant - others:AV ČR(CZ) CNR-16-17 Program:Bilaterální spolupráce Institutional support: RVO:67985891 Keywords : Polish shale gas * downhole microseismic processing * anisotropy * microseismic events Subject RIV: DC - Siesmology, Volcanology, Earth Structure OBOR OECD: Geology Impact factor: 0.699, year: 2016

Force-controlled patch clamp of beating cardiac cells.

Science.gov (United States)

Ossola, Dario; Amarouch, Mohamed-Yassine; Behr, Pascal; Vörös, János; Abriel, Hugues; Zambelli, Tomaso

2015-03-11

From its invention in the 1970s, the patch clamp technique is the gold standard in electrophysiology research and drug screening because it is the only tool enabling accurate investigation of voltage-gated ion channels, which are responsible for action potentials. Because of its key role in drug screening, innovation efforts are being made to reduce its complexity toward more automated systems. While some of these new approaches are being adopted in pharmaceutical companies, conventional patch-clamp remains unmatched in fundamental research due to its versatility. Here, we merged the patch clamp and atomic force microscope (AFM) techniques, thus equipping the patch-clamp with the sensitive AFM force control. This was possible using the FluidFM, a force-controlled nanopipette based on microchanneled AFM cantilevers. First, the compatibility of the system with patch-clamp electronics and its ability to record the activity of voltage-gated ion channels in whole-cell configuration was demonstrated with sodium (NaV1.5) channels. Second, we showed the feasibility of simultaneous recording of membrane current and force development during contraction of isolated cardiomyocytes. Force feedback allowed for a gentle and stable contact between AFM tip and cell membrane enabling serial patch clamping and injection without apparent cell damage.

Research on calibration method of downhole optical fiber temperature measurement and its application in SAGD well

Science.gov (United States)

Lu, Zhiwei; Han, Li; Hu, Chengjun; Pan, Yong; Duan, Shengnan; Wang, Ningbo; Li, Shijian; Nuer, Maimaiti

2017-10-01

With the development of oil and gas fields, the accuracy and quantity requirements of real-time dynamic monitoring data needed for well dynamic analysis and regulation are increasing. Permanent, distributed downhole optical fiber temperature and pressure monitoring and other online real-time continuous data monitoring has become an important data acquisition and transmission technology in digital oil field and intelligent oil field construction. Considering the requirement of dynamic analysis of steam chamber developing state in SAGD horizontal wells in F oil reservoir in Xinjiang oilfield, it is necessary to carry out real-time and continuous temperature monitoring in horizontal section. Based on the study of the principle of optical fiber temperature measurement, the factors that cause the deviation of optical fiber temperature sensing are analyzed, and the method of fiber temperature calibration is proposed to solve the problem of temperature deviation. Field application in three wells showed that it could attain accurate measurement of downhole temperature by temperature correction. The real-time and continuous downhole distributed fiber temperature sensing technology has higher application value in the reservoir management of SAGD horizontal wells. It also has a reference for similar dynamic monitoring in reservoir production.

Core clamping device for a nuclear reactor

International Nuclear Information System (INIS)

Guenther, R.W.

1974-01-01

The core clamping device for a fast neutron reactor includes clamps to support the fuel zone against the pressure vessel. The clamps are arranged around the circumference of the core. They consist of torsion bars arranged parallel at some distance around the core with lever arms attached to the ends whose force is directed in the opposite direction, pressing against the wall of the pressure vessel. The lever arms and pressure plates also actuated by the ends of the torsion bars transfer the stress, the pressure plates acting upon the fuel elements or fuel assemblies. Coupling between the ends of the torsion bars and the pressure plates is achieved by end carrier plates directly attached to the torsion bars and radially movable. This clamping device follows the thermal expansions of the core, allows specific elements to be disengaged in sections and saves space between the core and the neutron reflectors. (DG) [de

Lotus birth, a holistic approach on physiological cord clamping.

Science.gov (United States)

Zinsser, Laura A

2018-04-01

The positive effects of delayed cord clamping (DCC) has been extensively researched. DCC means: waiting at least one minute after birth before clamping and cutting the cord or till the pulsation has stopped. With physiological clamping and cutting (PCC) the clamping and cutting can happen at the earliest after the pulsation has stopped. With a Lotus birth, no clamping and cutting of the cord is done. A woman called Clair Lotus Day imitated the holistic approach of PCC from an anthropoid ape in 1974. The chimpanzee did not separate the placenta from the newborn. The aim of this case report is to discuss and learn a different approach in the third stage of labour. Three cases of Lotus birth by human beings were observed. All three women gave birth in an out-of-hospital setting and had ambulant postnatal care. The placenta was washed, salted and herbs were put on 2-3h post partum. The placenta was wrapped in something that absorbs the moisture. The salting was repeated with a degreasing frequency depending on moistness of the placenta. On life day six all three Lotus babies experiences a natural separation of the cord. All three Lotus birth cases were unproblematic, no special incidence occurred. One should differentiate between early cord clamping (ECC), delayed cord clamping (DCC) and physiological cord clamping (PCC). Lotus birth might lead to an optimisation of the bonding and attachment. Research is needed in the areas of both PCC and Lotus birth. Copyright © 2017 Australian College of Midwives. Published by Elsevier Ltd. All rights reserved.

π-Clamp-mediated cysteine conjugation

Science.gov (United States)

Zhang, Chi; Welborn, Matthew; Zhu, Tianyu; Yang, Nicole J.; Santos, Michael S.; van Voorhis, Troy; Pentelute, Bradley L.

2016-02-01

Site-selective functionalization of complex molecules is one of the most significant challenges in chemistry. Typically, protecting groups or catalysts must be used to enable the selective modification of one site among many that are similarly reactive, and general strategies that selectively tune the local chemical environment around a target site are rare. Here, we show a four-amino-acid sequence (Phe-Cys-Pro-Phe), which we call the ‘π-clamp’, that tunes the reactivity of its cysteine thiol for site-selective conjugation with perfluoroaromatic reagents. We use the π-clamp to selectively modify one cysteine site in proteins containing multiple endogenous cysteine residues. These examples include antibodies and cysteine-based enzymes that would be difficult to modify selectively using standard cysteine-based methods. Antibodies modified using the π-clamp retained binding affinity to their targets, enabling the synthesis of site-specific antibody-drug conjugates for selective killing of HER2-positive breast cancer cells. The π-clamp is an unexpected approach to mediate site-selective chemistry and provides new avenues to modify biomolecules for research and therapeutics.

Downhole Applications of Magnetic Sensors

Directory of Open Access Journals (Sweden)

Chinthaka P. Gooneratne

2017-10-01

Full Text Available In this paper we present a review of the application of two types of magnetic sensors—fluxgate magnetometers and nuclear magnetic resonance (NMR sensors—in the oil/gas industry. These magnetic sensors play a critical role in drilling wells safely, accurately and efficiently into a target reservoir zone by providing directional data of the well and acquiring information about the surrounding geological formations. Research into magnetic sensors for oil/gas drilling has not been explored by researchers to the same extent as other applications, such as biomedical, magnetic storage and automotive/aerospace applications. Therefore, this paper aims to serve as an opportunity for researchers to truly understand how magnetic sensors can be used in a downhole environment and to provide fertile ground for research and development in this area. A look ahead, discussing other magnetic sensor technologies that can potentially be used in the oil/gas industry is presented, and what is still needed in order deploy them in the field is also addressed.

Downhole Applications of Magnetic Sensors.

Science.gov (United States)

Gooneratne, Chinthaka P; Li, Bodong; Moellendick, Timothy E

2017-10-19

In this paper we present a review of the application of two types of magnetic sensors-fluxgate magnetometers and nuclear magnetic resonance (NMR) sensors-in the oil/gas industry. These magnetic sensors play a critical role in drilling wells safely, accurately and efficiently into a target reservoir zone by providing directional data of the well and acquiring information about the surrounding geological formations. Research into magnetic sensors for oil/gas drilling has not been explored by researchers to the same extent as other applications, such as biomedical, magnetic storage and automotive/aerospace applications. Therefore, this paper aims to serve as an opportunity for researchers to truly understand how magnetic sensors can be used in a downhole environment and to provide fertile ground for research and development in this area. A look ahead, discussing other magnetic sensor technologies that can potentially be used in the oil/gas industry is presented, and what is still needed in order deploy them in the field is also addressed.

Linking downhole logging data and clay mineralogy analysis in the ICDP Lake Junín drilling Project, Peru

Science.gov (United States)

Pierdominici, S.; Schleicher, A.; Kueck, J.; Rodbell, D. T.; Abbott, M. B.

2017-12-01

The lake Junin drilling project, co-funded by the International Continental Drilling Program (ICDP), is located at 4000 m a.s.l. in the tropical Andes of Peru. Several boreholes were drilled with the goal to obtain both high-resolution paleoclimate records from lacustrine sediments and to reconstruct the history of the continental records covering the glacial-interglacial cycles. Lake Junín is characterized by a thick package of lacustrine sediments (> 125 m) deposited at a high rate (0.2 to 1.0 mm yr-1), and it is one of the few lakes in the tropical Andes that is hundreds of thousands of years old with a continuous sedimentation rate preserving a very long and continuous record of past ice age cycles. The boreholes reached a maximum depth of 110.08 m and continuous coring was performed at three sites with 11 boreholes. Additionally, an extensive geophysical downhole logging campaign was performed on five boreholes (1A, 1C, 1D, 2A and 3B) by the Operational Support Group of ICDP. Downhole logging measurements comprise total and spectrum gamma ray, magnetic susceptibility, borehole geometry, temperature, and sonic p-wave velocity. In order to fit the downhole logging depths to the composite profile depths, each borehole was depth-matched with the core data. Interpreting the downhole logging data permits to establish a complete lithological log, to characterize the in-situ physical properties of drilled lacustrine sediments, to determine sedimentary structures and to obtain evidences about palaeoclimatic conditions during up to 200 ka. Th and K values are used as a proxy for a first estimate and characterization of clay content in the sediments, which are present as montmorillonite, smectite, illite, and kaolinite in different amounts. Linking the clay minerals that occur in the core material with the downhole logging data allows assessing the geological history of the lake and the relationship to climate change processes. Additional laboratory analysis will be

Seismic velocities and geologic logs from boreholes at three downhole arrays in San Francisco, California

Science.gov (United States)

Gibbs, James F.; Fumal, Thomas E.; Borcherdt, Roger D.; Warrick, Richard E.; Liu, Hsi-Ping; Westerlund, Robert E.

1994-01-01

The Loma Prieta earthquake of October 17, 1989 (1704 PST), has reinforced observations made by Wood and others (1908) after the 1906 San Francisco earthquake, that poor ground conditions (soft soil) increase the likelihood of shaking damage to structures. Since 1908 many studies (for example Borcherdt, 1970, Borcherdt and Gibbs, 1976, Borcherdt and Glassmoyer, 1992) have shown that soft soils amplify seismic waves at frequencies that can be damaging to structures. Damage in the City of San Francisco from the Loma Prieta earthquake was concentrated in the Marina District, the Embarcadero, and the China Basin areas. Each of these areas, to some degree, is underlain by soft soil deposits. These concentrations of damage raise important questions regarding the amplification effects of such deposits at damaging levels of motion. Unfortunately, no strong-motion recordings were obtained in these areas during the Loma Prieta earthquake and only a limited number (< 10) have been obtained on other soft soil sites in the United States. Consequently, important questions exist regarding the response of such deposits during damaging earthquakes, especially questions regarding the nonlinear soil response. Towards developing a data set to address these important questions, borehole strong-motion arrays have been installed at three locations. These arrays consist of groups of wide-dynamic-range pore-pressure transducers and three-component accelerometers, the outputs of which are recorded digitally. The arrays are designed to provide an integrated set of data on ground shaking, liquifaction-induced ground failure, and structural response. This report describes the detailed geologic, seismic, and material-property determinations derived at each of these sites.

A new clamp method for firing bricks | Obeng | Journal of Applied ...

African Journals Online (AJOL)

A new clamp method for firing bricks. ... Journal of Applied Science and Technology ... To overcome this operational deficiencies, a new method of firing bricks that uses brick clamp technique that incorporates a clamp wall of 60 cm thickness, a six tier approach of sealing the top of the clamp (by combination of green bricks) ...

IMPORTANT: Fluke is recalling Digital Clamp Meters

CERN Multimedia

2013-01-01

Fluke is voluntarily recalling four models of Digital Clamp Meters: Fluke 373, 374, 375 and 376. If you own one of these clamp meters, please stop using it and send it back to Fluke for repair even if you have not experienced problems.   Description of the problem: "The printed circuit assembly may not be properly fastened to the test lead input jack. This may result in inaccurate voltage readings, including a low or no-voltage reading on a circuit energised with a hazardous voltage, presenting a shock, electrocution or thermal burn hazard." To determine if your clamp meter is affected by this recall notice, and for more information, click here.

Is "Delayed Umbilical Cord Clamping" Beneficial for Premature Newborns?

Directory of Open Access Journals (Sweden)

Amir-Mohammad Armanian

2017-05-01

Full Text Available Background: The appropriate moment for clamping the umbilical cord is controversial. Immediate cord clamping (ICC is an item of active management of the third stage of labor (AMTSL. Unclamped umbilical cord may cause inconvenience in preterm neonates because they commonly need some levels of emergent services. Some studies revealed delayed cord clamping (DCC of preterm neonates results in better health conditions like lower rates of respiratory distress syndrome (RDS, less morbidities in labor room and lower risk of postpartum hemorrhage. The aim of the present study was to determine the effect of delayed umbilical cord clamping on premature neonatal outcomes. Materials and Methods: In this single‑center randomized control trial study, sixty premature neonates (gestational age ≤ 34 weeks were randomly assigned to ICC (cord clamped at 5–10 seconds or DCC (30–45 seconds groups and followed up in neonatal intensive care unit (NICU. Primary outcomes were 1st and 5th minute Apgar score, average of level of hematocrit after birth, intra ventricle hemorrhage and need some levels of resuscitation. Results: Differences in demographic characteristics were not statistically significant. After birth, neonates who had delayed clamping had significantly higher mean hematocrit after at 4-hour of birth (49.58+5.15gr/dl vs. 46.58+5.40gr/dlin DCC vs. ICC groups, respectively (P=0.031. Delayed cord clamping reduced the duration of need to nasal continues positive airway pressure (NCPAP (86.7% and 60.0% in ICC and DCC groups, respectively, P= 0.039. Attractively, the results showed lower incidence of clinical sepsis in delayed cord clamping neonates (53.3% vs. 23.3% in ICC and DCC groups, respectively, P=0.033. Conclusion: Prematurity complications might decrease by delay umbilical cord clamping which improve the hematocrit, duration of need to NCPAP and incidence of clinical sepsis. Furthermore, DCC may have no negative impact on neonatal resuscitation.

A missing factor in chip-based patch clamp assay: gigaseal

International Nuclear Information System (INIS)

Ong, W-L; Yobas, L; Ong, W-Y

2006-01-01

The 'gold' standard in the study of ionic currents across biological membranes is the Patch Clamp method. However, this is a slow, labor and skill intensive process. High throughput patch clamp devices are mainly chip-based. A major challenge in these miniaturized devices is the low rate of 'Gigaseal' formation which is critical in the study of Single Channel effect. In a conventional patch clamp, a pipette moves and patches a fixed cell (cell-adhered patch) which is grown on the bottom of a Petri dish. In the chip-based case, the cells are in suspension and move towards the fixed patch clamp sites (cell-suspended patch). In this study, using the proven conventional patch clamp setup, we investigated the effect of the differences in the cell configurations between the convention patch clamp and cell-based patch clamp. It is shown that adhered cells (as used in the conventional setup) have a much higher rate of gigaseal formation as compared to the cells in suspension (as used in chip-based devices). We postulate that the arrangement of the cytoskeleton within the cell plays a major part in the formation of the gigaseal

Patch-Clamp Recording from Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes: Improving Action Potential Characteristics through Dynamic Clamp

Science.gov (United States)

Veerman, Christiaan C.; Zegers, Jan G.; Mengarelli, Isabella; Bezzina, Connie R.

2017-01-01

Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) hold great promise for studying inherited cardiac arrhythmias and developing drug therapies to treat such arrhythmias. Unfortunately, until now, action potential (AP) measurements in hiPSC-CMs have been hampered by the virtual absence of the inward rectifier potassium current (IK1) in hiPSC-CMs, resulting in spontaneous activity and altered function of various depolarising and repolarising membrane currents. We assessed whether AP measurements in “ventricular-like” and “atrial-like” hiPSC-CMs could be improved through a simple, highly reproducible dynamic clamp approach to provide these cells with a substantial IK1 (computed in real time according to the actual membrane potential and injected through the patch-clamp pipette). APs were measured at 1 Hz using perforated patch-clamp methodology, both in control cells and in cells treated with all-trans retinoic acid (RA) during the differentiation process to increase the number of cells with atrial-like APs. RA-treated hiPSC-CMs displayed shorter APs than control hiPSC-CMs and this phenotype became more prominent upon addition of synthetic IK1 through dynamic clamp. Furthermore, the variability of several AP parameters decreased upon IK1 injection. Computer simulations with models of ventricular-like and atrial-like hiPSC-CMs demonstrated the importance of selecting an appropriate synthetic IK1. In conclusion, the dynamic clamp-based approach of IK1 injection has broad applicability for detailed AP measurements in hiPSC-CMs. PMID:28867785

ENHANCED OIL RECOVERY WITH DOWNHOLE VIBRATION STIMULATION IN OSAGE COUNTY OKLAHOMA

Energy Technology Data Exchange (ETDEWEB)

Robert Westermark; J. Ford Brett

2003-11-01

This Final Report covers the entire project from July 13, 2000 to June 30, 2003. The report summarizes the details of the work done on the project entitled ''Enhanced Oil Recovery with Downhole Vibration Stimulation in Osage County Oklahoma'' under DOE Contract Number DE-FG26-00BC15191. The project was divided into nine separate tasks. This report is written in an effort to document the lessons learned during the completion of each task. Therefore each task will be discussed as the work evolved for that task throughout the duration of the project. Most of the tasks are being worked on simultaneously, but certain tasks were dependent on earlier tasks being completed. During the three years of project activities, twelve quarterly technical reports were submitted for the project. Many individual topic and task specific reports were included as appendices in the quarterly reports. Ten of these reports have been included as appendices to this final report. Two technical papers, which were written and accepted by the Society of Petroleum Engineers, have also been included as appendices. The three primary goals of the project were to build a downhole vibration tool (DHVT) to be installed in seven inch casing, conduct a field test of vibration stimulation in a mature waterflooded field and evaluate the effects of the vibration on both the produced fluid characteristics and injection well performance. The field test results are as follows: In Phase I of the field test the DHVT performed exceeding well, generating strong clean signals on command and as designed. During this phase Lawrence Berkeley National Laboratory had installed downhole geophones and hydrophones to monitor the signal generated by the downhole vibrator. The signals recorded were strong and clear. Phase II was planned to be ninety-day reservoir stimulation field test. This portion of the field tests was abruptly ended after one week of operations, when the DHVT became stuck in the well

Surface-seismic imaging for nehrp soil profile classifications and earthquake hazards in urban areas

Science.gov (United States)

Williams, R.A.; Stephenson, W.J.; Odum, J.K.

1998-01-01

We acquired high-resolution seismic-refraction data on the ground surface in selected areas of the San Fernando Valley (SFV) to help explain the earthquake damage patterns and the variation in ground motion caused by the 17 January 1994 magnitude 6.7 Northridge earthquake. We used these data to determine the compressional- and shear-wave velocities (Vp and Vs) at 20 aftershock recording sites to 30-m depth ( V??s30, and V??p30). Two other sites, located next to boreholes with downhole Vp and Vs data, show that we imaged very similar seismic-vefocity structures in the upper 40 m. Overall, high site response appears to be associated with tow Vs in the near surface, but there can be a wide rangepf site amplifications for a given NEHRP soil type. The data suggest that for the SFV, if the V??s30 is known, we can determine whether the earthquake ground motion will be amplified above a factor of 2 relative to a local rock site.

Assessment and interpretation of cross- and down-hole seismograms at the Paducah Gaseous Diffusion Plant

Energy Technology Data Exchange (ETDEWEB)

Staub, W.P.; Wang, J.C. (Oak Ridge National Lab., TN (United States)); Selfridge, R.J. (Automated Sciences Group, (United States))

1991-09-01

This paper is an assessment and interpretation of cross-and down-hole seismograms recorded at four sites in the vicinity of the Paducah Gaseous Diffusion Plant (PGDP). Arrival times of shear (S-) and compressional (P-) waves are recorded on these seismograms in milliseconds. Together with known distances between energy sources and seismometers lowered into boreholes, these arrival times are used to calculate S- and P-wave velocities in unconsolidated soils and sediments that overlie bedrock approximately 320 ft beneath PGDP. The soil columns are modified after an earlier draft by ERC Environmental and Energy Services Company (ERCE), 1990. In addition to S- and P- wave velocity estimates from this paper, the soil columns contain ERCE's lithologic and other geotechnical data for unconsolidated soils and sediments from the surface to bedrock. Soil columns for Sites 1 through 4 and a site location map are in Plates 1 through 5 of Appendix 6. The velocities in the four columns are input parameters for the SHAKE computer program, a nationally recognized computer model that simulates ground response of unconsolidated materials to earthquake generated seismic waves. The results of the SHAKE simulation are combined with predicted ground responses on rock foundations (caused by a given design earthquake) to predict ground responses of facilities with foundations placed on unconsolidated materials. 3 refs.

Evaluation and Design of Downhole Heat Exchangers for Direct Application

Energy Technology Data Exchange (ETDEWEB)

Culver, G [Oregon Institute of Technology, Klamath Falls, Oregon; Reistad, G M [Oregon State University, Corvallis, Oregon

0000-12-30

Over 400 wells with downhole heat exchangers are in use in Klamath Falls, Oregon. Some have been in use for nearly 30 years. Despite the large number and the long experience, the exact nature of the mechanism of heat exchange and, therefore, the maximum output was not known, except that it had been theorized that convection cells were established in the well. Oregon Institute of Technology and Oregon State University are jointly involved in a project to study the heat exchange process and economics of the downhole heat exchanger system. The existence of significant convection cell circulation has been established and measured using a “spinner,” hot film anemometer, and by energy balance calculations. Based on these measurements, analytical models have been developed which predict heat extraction rates within 15% of actual measured values. The existence of significant mixing of “new” and circulating well fluid has been established and can be calculated, although at this time not accurately predicted before testing a well. Based on the analytical models, multi-tube heat exchangers have been designed and very recently tested with outputs within 15% of predicted values. Economic analyses shows that for small to moderate extraction rates, about 300 kW thermal, and shallow wells, DHEs may be more economical than pumped systems when surface discharge is not acceptable.

Seismic testing and analysis of a prototypic nonlinear piping system

International Nuclear Information System (INIS)

Barta, D.A.; Anderson, M.J.; Severud, L.K.

1982-11-01

A series of seismic tests and analyses of a nonlinear Fast Flux Test Facility (FFTF) prototypic piping system are described, and measured responses are compared with analytical predictions. The test loop was representative of a typical LMFBR insulated small bore piping system and it was supported from a rigid test frame by prototypic dead weight supports, mechanical snubbers and pipe clamps. Various piping support configurations were tested and analyzed to evaluate the effects of free play and other nonlinear stiffness characteristics on the piping system response

Reducing blood loss during laparoscopic myomectomy by temporary uterine artery clamping using bulldog clamp

Directory of Open Access Journals (Sweden)

Kai-Jo Chiang

2014-01-01

Full Text Available Uterine myoma is the most common benign gynecologic tumor worldwide. Mini-invasive surgery has become popular for myomectomy, with advantages over laparotomy. However, reducing blood loss during laparoscopic myomectomy is a major concern for the surgeon because of the limitation in making a quick control bleeding during the operation. Several methods have proved to decrease blood flow, but are not always effective or available. We present a case of uterine myoma with the uterine arteries clamped by bulldog clamps during laparoscopic myomectomy. The myoma was removed successfully with minimal blood loss (<50 ml during the operation. This is an effective, safe, and reliable method for reducing bleeding during laparoscopic myomectomy that does not require ligation of the uterine artery.

Planar patch clamp: advances in electrophysiology.

Science.gov (United States)

Brüggemann, Andrea; Farre, Cecilia; Haarmann, Claudia; Haythornthwaite, Ali; Kreir, Mohamed; Stoelzle, Sonja; George, Michael; Fertig, Niels

2008-01-01

Ion channels have gained increased interest as therapeutic targets over recent years, since a growing number of human and animal diseases have been attributed to defects in ion channel function. Potassium channels are the largest and most diverse family of ion channels. Pharmaceutical agents such as Glibenclamide, an inhibitor of K(ATP) channel activity which promotes insulin release, have been successfully sold on the market for many years. So far, only a small group of the known ion channels have been addressed as potential drug targets. The functional testing of drugs on these ion channels has always been the bottleneck in the development of these types of pharmaceutical compounds.New generations of automated patch clamp screening platforms allow a higher throughput for drug testing and widen this bottleneck. Due to their planar chip design not only is a higher throughput achieved, but new applications have also become possible. One of the advantages of planar patch clamp is the possibility of perfusing the intracellular side of the membrane during a patch clamp experiment in the whole-cell configuration. Furthermore, the extracellular membrane remains accessible for compound application during the experiment.Internal perfusion can be used not only for patch clamp experiments with cell membranes, but also for those with artificial lipid bilayers. In this chapter we describe how internal perfusion can be applied to potassium channels expressed in Jurkat cells, and to Gramicidin channels reconstituted in a lipid bilayer.

Analysis of the role of PCNA-DNA contacts during clamp loading

Directory of Open Access Journals (Sweden)

Goedken Eric R

2010-01-01

Full Text Available Abstract Background Sliding clamps, such as Proliferating Cell Nuclear Antigen (PCNA in eukaryotes, are ring-shaped protein complexes that encircle DNA and enable highly processive DNA replication by serving as docking sites for DNA polymerases. In an ATP-dependent reaction, clamp loader complexes, such as the Replication Factor-C (RFC complex in eukaryotes, open the clamp and load it around primer-template DNA. Results We built a model of RFC bound to PCNA and DNA based on existing crystal structures of clamp loaders. This model suggests that DNA would enter the clamp at an angle during clamp loading, thereby interacting with positively charged residues in the center of PCNA. We show that simultaneous mutation of Lys 20, Lys 77, Arg 80, and Arg 149, which interact with DNA in the RFC-PCNA-DNA model, compromises the ability of yeast PCNA to stimulate the DNA-dependent ATPase activity of RFC when the DNA is long enough to extend through the clamp. Fluorescence anisotropy binding experiments show that the inability of the mutant clamp proteins to stimulate RFC ATPase activity is likely caused by reduction in the affinity of the RFC-PCNA complex for DNA. We obtained several crystal forms of yeast PCNA-DNA complexes, measuring X-ray diffraction data to 3.0 Å resolution for one such complex. The resulting electron density maps show that DNA is bound in a tilted orientation relative to PCNA, but makes different contacts than those implicated in clamp loading. Because of apparent partial disorder in the DNA, we restricted refinement of the DNA to a rigid body model. This result contrasts with previous analysis of a bacterial clamp bound to DNA, where the DNA was well resolved. Conclusion Mutational analysis of PCNA suggests that positively charged residues in the center of the clamp create a binding surface that makes contact with DNA. Disruption of this positive surface, which had not previously been implicated in clamp loading function, reduces RFC

File list: Oth.ALL.50.Clamp.AllCell [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available Oth.ALL.50.Clamp.AllCell dm3 TFs and others Clamp All cell types SRX159172,SRX15917...0,SRX159174,SRX159166,SRX159173 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Oth.ALL.50.Clamp.AllCell.bed ...

Deep Downhole Seismic Testing at the Waste Treatment Plant Site, Hanford, WA. Volume V S-Wave Measurements in Borehole C4996 Seismic Records, Wave-Arrival Identifications and Interpreted S-Wave Velocity Profile.

Energy Technology Data Exchange (ETDEWEB)

Stokoe, Kenneth H.; Li, Song Cheng; Cox, Brady R.; Menq, Farn-Yuh

2007-06-06

Velocity measurements in shallow sediments from ground surface to approximately 370 to 400 feet bgs were collected by Redpath Geophysics using impulsive S- and P-wave seismic sources (Redpath 2007). Measurements below this depth within basalt and sedimentary interbeds were made by UTA between October and December 2006 using the T-Rex vibratory seismic source in each of the three boreholes. Results of these measurements including seismic records, wave-arrival identifications and interpreted velocity profiles are presented in the following six volumes: I. P-Wave Measurements in Borehole C4993 II. P-Wave Measurements in Borehole C4996 III. P-Wave Measurements in Borehole C4997 IV. S-Wave Measurements in Borehole C4993 V. S-Wave Measurements in Borehole C4996 VI. S-Wave Measurements in Borehole C4997 In this volume (V), all S-wave measurements are presented that were performed in Borehole C4996 at the WTP with T-Rex as the seismic source and the Lawrence Berkeley National Laboratory (LBNL) 3-D wireline geophone as the at-depth borehole receiver.

Deep Downhole Seismic Testing at the Waste Treatment Plant Site, Hanford, WA. Volume VI S-Wave Measurements in Borehole C4997 Seismic Records, Wave-Arrival Identifications and Interpreted S-Wave Velocity Profile.

Energy Technology Data Exchange (ETDEWEB)

Stokoe, Kenneth H.; Li, Song Cheng; Cox, Brady R.; Menq, Farn-Yuh

2007-06-06

Velocity measurements in shallow sediments from ground surface to approximately 370 to 400 feet bgs were collected by Redpath Geophysics using impulsive S- and P-wave seismic sources (Redpath 2007). Measurements below this depth within basalt and sedimentary interbeds were made by UTA between October and December 2006 using the T-Rex vibratory seismic source in each of the three boreholes. Results of these measurements including seismic records, wave-arrival identifications and interpreted velocity profiles are presented in the following six volumes: I. P-Wave Measurements in Borehole C4993 II. P-Wave Measurements in Borehole C4996 III. P-Wave Measurements in Borehole C4997 IV. S-Wave Measurements in Borehole C4993 V. S-Wave Measurements in Borehole C4996 VI. S-Wave Measurements in Borehole C4997 In this volume (VI), all S-wave measurements are presented that were performed in Borehole C4997 at the WTP with T-Rex as the seismic source and the Lawrence Berkeley National Laboratory (LBNL) 3-D wireline geophone as the at-depth borehole receiver.

Ruggedized downhole tool for real-time measurements and uses thereof

Energy Technology Data Exchange (ETDEWEB)

Hess, Ryan Falcone; Lindblom, Scott C.; Yelton, William G.; Limmer, Steven J.; Boyle, Timothy J.; Cieslewski, Grzegorz

2018-01-09

The present invention relates to ruggedized downhole tools and sensors, as well as uses thereof. In particular, these tools can operate under extreme conditions and, therefore, allow for real-time measurements in geothermal reservoirs or other potentially harsh environments. One exemplary sensor includes a ruggedized ion selective electrode (ISE) for detecting tracer concentrations in real-time. In one embodiment, the ISE includes a solid, non-conductive potting material and an ion selective material, which are disposed in a temperature-resistant electrode body. Other electrode configurations, tools, and methods are also described.

Modeling of SVM Diode Clamping Three-Level Inverter Connected to Grid

DEFF Research Database (Denmark)

Guo, Yougui; Zeng, Ping; Zhu, Jieqiong

2011-01-01

PLECS is used to model the diode clamping three-level inverter connected to grid and good results are obtained. First the output voltage SVM is described for diode clamping three-level inverter with loads connected to Y. Then the output voltage SVM of diode clamping three-level inverter is simply...... analyzed with loads connected to △. But it will be further researched in the future. Third, PLECS is briefly introduced. Fourth, the modeling of diode clamping three-level inverter is briefly presented with PLECS. Finally, a series of simulations are carried out. The simulation results tell us PLECS...... is very powerful tool to real power circuits and it is very easy to simulate them. They have also verified that SVM control strategy is feasible to control the diode clamping three-level inverter....

Detailed evaluation of gas hydrate reservoir properties using JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well downhole well-log displays

Science.gov (United States)

Collett, T.S.

1999-01-01

The JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well project was designed to investigate the occurrence of in situ natural gas hydrate in the Mallik area of the Mackenzie Delta of Canada. Because gas hydrate is unstable at surface pressure and temperature conditions, a major emphasis was placed on the downhole logging program to determine the in situ physical properties of the gas-hydrate-bearing sediments. Downhole logging tool strings deployed in the Mallik 2L-38 well included the Schlumberger Platform Express with a high resolution laterolog, Array Induction Imager Tool, Dipole Shear Sonic Imager, and a Fullbore Formation Microlmager. The downhole log data obtained from the log- and core-inferred gas-hydrate-bearing sedimentary interval (897.25-1109.5 m log depth) in the Mallik 2L-38 well is depicted in a series of well displays. Also shown are numerous reservoir parameters, including gas hydrate saturation and sediment porosity log traces, calculated from available downhole well-log and core data. The gas hydrate accumulation delineated by the Mallik 2L-38 well has been determined to contain as much as 4.15109 m3 of gas in the 1 km2 area surrounding the drill site.

Crystal structure of DNA polymerase III β sliding clamp from Mycobacterium tuberculosis.

Science.gov (United States)

Gui, Wen-Jun; Lin, Shi-Qiang; Chen, Yuan-Yuan; Zhang, Xian-En; Bi, Li-Jun; Jiang, Tao

2011-02-11

The sliding clamp is a key component of DNA polymerase III (Pol III) required for genome replication. It is known to function with diverse DNA repair proteins and cell cycle-control proteins, making it a potential drug target. To extend our understanding of the structure/function relationship of the sliding clamp, we solved the crystal structure of the sliding clamp from Mycobacterium tuberculosis (M. tuberculosis), a human pathogen that causes most cases of tuberculosis (TB). The sliding clamp from M. tuberculosis forms a ring-shaped head-to-tail dimer with three domains per subunit. Each domain contains two α helices in the inner ring that lie against two β sheets in the outer ring. Previous studies have indicated that many Escherichia coli clamp-binding proteins have a conserved LF sequence, which is critical for binding to the hydrophobic region of the sliding clamp. Here, we analyzed the binding affinities of the M. tuberculosis sliding clamp and peptides derived from the α and δ subunits of Pol III, which indicated that the LF motif also plays an important role in the binding of the α and δ subunits to the sliding clamp of M. tuberculosis. Copyright © 2011 Elsevier Inc. All rights reserved.

Tuning permanent magnets with adjustable field clamps

International Nuclear Information System (INIS)

Schermer, R.I.

1987-01-01

The effective length of a permanent-magnet assembly can be varied by adjusting the geometrical parameters of a field clamp. This paper presents measurements on a representative dipole and quadrupole as the field clamp is withdrawn axially or radially. The detailed behavior depends upon the magnet multipolarity and geometry. As a rule-of-thumb, a 3-mm-thick iron plate placed at one end plane of the magnet will shorten the length by one-third of the magnet bore radius

Analysis and Experiments on Sea Load and Fastened Mechanics on Pipe Clamps

Directory of Open Access Journals (Sweden)

Wang Zhuo

2017-08-01

Full Text Available When an offshore oil field completed and put into production, new subsea pipelines and the new cable need to be established. Cable protection pipe clamp is used to fix cable protection pipe on the jacket. In order to avoid the problem of traditional steel structure clamp splice, counterpoint, fastening difficulty when installed cable protection pipe under water, reduce the risk and workload of under water, This paper develop a new type of portable connecting riser clamp -“backpack clamp” which solve the riser cable protection pipe difficult underwater installation problem. The main structure of backpack clamp used three valves type structure. The load characteristic of a clamping device was determined by the Morison equation which was a classical theory. Clamp device underwater mechanics analysis model was established. The minimum tension pre-tightening force was determined. The results show that the strength of the base meets the requirements after strength analysis with finite element analysis method, stability and strength experiments, which means the clamp based on resin matrix composite is feasible.

Physical Properties and Seismic Structure of Izu-Bonin-Mariana Fore Arc crust: Results From IODP Expedition 352 and Comparison with Oceanic Crust

Science.gov (United States)

Christeson, G. L.; Morgan, S.; Kodaira, S.; Yamashita, M.

2015-12-01

Most of the well-preserved ophiolite complexes are believed to form in supra-subduction zone settings. One of the goals of IODP Expedition 352 was to test the supra-subduction zone ophiolite model by drilling forearc crust at the northern Izu-Bonin-Mariana (IBM) system. IBM forearc drilling successfully cored 1.22 km of volcanic lavas and underlying dikes at four sites. A surprising observation is that basement compressional velocities measured from downhole logging average ~3.0 km/s, compared to values of 5 km/s at similar basement depths at oceanic crust sites 504B and 1256D. Typically there is an inverse relationship in extrusive lavas between velocity and porosity, but downhole logging shows similar porosities for the IBM and oceanic crust sites, despite the large difference in measured compressional velocities. These observations can be explained by a difference in crack morphologies between IBM forearc and oceanic crust, with a smaller fractional area of asperity contact across cracks at EXP 352 sites than at sites 504B and 1256D. Seismic profiles at the IBM forearc image many faults, which may be related to the crack population.

Earth modeling and estimation of the local seismic ground motion due to site geology in complex volcanoclastic areas

Directory of Open Access Journals (Sweden)

V. Di Fiore

2002-06-01

Full Text Available Volcanic areas often show complex behaviour as far as seismic waves propagation and seismic motion at surface are concerned. In fact, the finite lateral extent of surface layers such as lava flows, blocks, differential welding and/or zeolitization within pyroclastic deposits, introduces in the propagation of seismic waves effects such as the generation of surface waves at the edge, resonance in lateral direction, diffractions and scattering of energy, which tend to modify the amplitude as well as the duration of the ground motion. The irregular topographic surface, typical of volcanic areas, also strongly influences the seismic site response. Despite this heterogeneity, it is unfortunately a common geophysical and engineering practice to evaluate even in volcanic environments the subsurface velocity field with monodimensional investigation method (i.e. geognostic soundings, refraction survey, down-hole, etc. prior to the seismic site response computation which in a such cases is obviously also made with 1D algorithms. This approach often leads to highly inaccurate results. In this paper we use a different approach, i.e. a fully 2D P-wave Çturning rayÈ tomographic survey followed by 2D seismic site response modeling. We report here the results of this approach in three sites located at short distance from Mt. Vesuvius and Campi Flegrei and characterized by overburdens constituted by volcanoclastic deposits with large lateral and vertical variations of their elastic properties. Comparison between 1D and 2D Dynamic Amplification Factor shows in all reported cases entirely different results, both in terms of peak period and spectral contents, as expected from the clear bidimensionality of the geological section. Therefore, these studies suggest evaluating carefully the subsoil geological structures in areas characterized by possible large lateral and vertical variations of the elastic properties in order to reach correct seismic site response

Active energy recovery clamping circuit to improve the performance of power converters

Science.gov (United States)

Whitaker, Bret; Barkley, Adam

2017-05-09

A regenerative clamping circuit for a power converter using clamping diodes to transfer charge to a clamping capacitor and a regenerative converter to transfer charge out of the clamping capacitor back to the power supply input connection. The regenerative converter uses a switch connected to the midpoint of a series connected inductor and capacitor. The ends of the inductor and capacitor series are connected across the terminals of the power supply to be in parallel with the power supply.

Advanced Data Communications for Downhole Data Logging and Control Applications in the Oil Industry

International Nuclear Information System (INIS)

Spracklen, C T; Aslam, Tariq

2013-01-01

We present details of 'Mercury', a high-speed downhole communications system that utilizes the (metallic) wall of a gas or oil pipeline or a drill 'string' as the communications 'channel' to control or monitor equipment or sensors used in the oil industry. Conventional downhole communication systems typically use 'mud pulse' telemetry for 'Measurement While Drilling' (MWD) operations. Current mud pulse telemetry technology offers bandwidths of up to 40 bit/s. However the data rate drops with increasing length of the wellbore and is typically as low as 1.5 bit/s – 3.0 bit/s at a depth of 35,000 ft. – 40,000 ft. The system described, by contrast, offers data rates of several megabits per second over distances of many kilometres and uses Orthogonal Frequency Division Multiplexing (OFDM) coupled with Wideband Frequency Division Multiple Access (W-CDMA). This paper presents details of our system; results of several trials undertaken on actual gas pipelines in the UK will be presented at the Conference

File list: Oth.CeL.50.Clamp.AllCell [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available Oth.CeL.50.Clamp.AllCell dm3 TFs and others Clamp Cell line SRX159172,SRX159170,SRX...159174,SRX159166,SRX159173 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Oth.CeL.50.Clamp.AllCell.bed ...

File list: Oth.CeL.05.Clamp.AllCell [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available Oth.CeL.05.Clamp.AllCell dm3 TFs and others Clamp Cell line SRX159172,SRX159170,SRX...159174,SRX159166,SRX159173 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Oth.CeL.05.Clamp.AllCell.bed ...

[Analysis of brain hemometabolism behavior during carotid endarterectomy with temporary clamping.].

Science.gov (United States)

Duval Neto, Gastão Fernandes; Niencheski, Augusto H

2004-04-01

Carotid endarterectomy with temporary clamping changes cerebral blood flow and cerebral metabolic oxygen demand ratio with consequent oligemic hypoxia or hemometabolic uncoupling. This study aimed at identifying changes in brain hemometabolism, evaluated through changes in oxyhemoglobin saturation in internal jugular vein bulb (SvjO2) during carotid endarterectomy with clamping, and at correlating these changes with potentially interfering factors, mainly end tidal CO2 pressure (P ET CO2) and cerebral perfusion pressure (CPP). Sixteen patients with unilateral carotid stenotic disease scheduled to carotid endarterectomy with carotid arterial clamping were enrolled in this study. Parameters including internal jugular bulb oxyhemoglobin saturation, stump pressure and end tidal CO2 pressure were measured at the following moments: M1 - pre-clamping; M2 - 3 minutes after clamping; M3 - pre-unclamping; M4 - post-unclamping). The comparison among SvjO2 (%, mean +/- SD) in all studied periods has shown differences between those recorded in moments M1 (52.25 +/- 7.87) and M2 (47.43 +/- 9.19). This initial decrease stabilized during temporary clamping, showing decrease in the comparison between M2 and M3 (46.56 +/- 9.25), without statistical significance (p = ns). At post-unclamping, M4 (47.68 +/- 9.12), SvjO2 was increased as compared to M2 and M3 clamping stages, however it was still lower than that of pre-clamping stage M1.(M4 x M1 - p brain hemometabolic uncoupling trend were correlated to P ET CO2. The comparison between CPP and SvjO2 showed weak correlation devoid of statistical significance. In the conditions of our study, SvjO2 measurement is a fast and effective way of clinically monitoring changes in CBF/CMRO2 ratio. Temporary carotid clamping implies in a trend towards brain hemometabolic uncoupling and, as a consequence, to oligemic ischemia; cerebral perfusion pressure does not assesses brain hemometabolic status (CBF and CMRO2 ratio); hypocapnia, may lead to

275 C Downhole Switched-Mode Power Supply

Energy Technology Data Exchange (ETDEWEB)

Chris Hutchens; Vijay Madhuravasal

2008-08-31

A vee-square (V2) control based controller IC is developed for a switch mode power supply capable of operating at extreme temperature/harsh environment conditions. A buck type regulator with silicon carbide power junction field effect transistors (JFET) as power devices is used to analyze the performance of controller. Special emphases are made on the analog sub-blocks--voltage reference, operational transconductance amplifier and comparator as individual building blocks. Transformer coupled gate drives and high temperature operable magnetic cores and capacitors are identified and tested for use in the design. Conventional ceramic chip packaging of ICs combined with lead carrier type mounting of passive filter components is introduced for hybrid packaging of the complete product. The developed SMPS is anticipated to support the operation of down-hole microcontrollers and other electronics devices that require low/medium power filtered dc inputs over an operating temperature of 275 C.

The role of duplex stainless steels for downhole tubulars

International Nuclear Information System (INIS)

Francis, R.

1993-01-01

In sour conditions there is an increasing trend to turn to corrosion resistant alloys for downhole tubulars. The most commonly used CRA tubular is 13Cr, and there are thousands of feet in service. However, there are limits to the use of 13Cr, ie., the risk of sulphide stress corrosion cracking at high H 2 S levels, and the possibility of pitting or high corrosion rates in waters with high chloride contents. Where the service conditions are felt to be too severe for 13Cr alloys it has been traditional to switch to nickel base alloys such as alloys 825 and C-276 (UNS N08825 and N10276). The alloys are much more expensive than 13Cr, and in recent years the duplex stainless steels have been selected as alloys with superior corrosion and SSCC resistance compared with 13Cr, and having lower cost than nickel alloys. Originally the 22Cr duplex alloy (UNS 31803) was used, but more recently the 25Cr super duplex alloys (UNS S32760 and S32750) have become more available. The present paper reviews the data available for 13Cr and the limits of applicability. Data is also presented for laboratory tests for both the 22Cr and 25Cr super duplex alloys. There is extensive service experience with both 22Cr and 25Cr super duplex in the North Sea, covering both downhole tubulars, manifold and post wellhead equipment. Data is presented showing some of the sour condition being experienced in the North Sea by super duplex alloys. These results show that there is a substantial gap between the limits of use for 13Cr and the 25Cr super duplex stainless steel alloys. This means that in many sour environments super duplex stainless steel provides a cost effective alternative to nickel-base alloys

Development and validation of the downhole freestanding shear device (DFSD) for measuring the dynamic properties of clay.

Science.gov (United States)

2008-12-01

The Downhole Freestanding Shear Device (DFSD) is an innovative tool developed for in situ measurement of dynamic : properties (modulus and damping) of clay soils over a broad range of strains. The device essentially performs : laboratory-quality tors...

Source Characterization and Seismic Hazard Considerations for Hydraulic Fracture Induced Seismicity

Science.gov (United States)

Bosman, K.; Viegas, G. F.; Baig, A. M.; Urbancic, T.

2015-12-01

Large microseismic events (M>0) have been shown to be generated during hydraulic fracture treatments relatively frequently. These events are a concern both from public safety and engineering viewpoints. Recent microseismic monitoring projects in the Horn River Basin have utilized both downhole and surface sensors to record events associated with hydraulic fracturing. The resulting hybrid monitoring system has produced a large dataset with two distinct groups of events: large events recorded by the surface network (0structures; small events are concentrated at reservoir depth. Differences in behavior have been observed between these two datasets, leading to conclusions of different underlying processes responsible for the recorded activity. Both datasets show very low seismic efficiency, implying slip weakening and possibly the presence of fluids in the source region. Reservoir events have shear-tensile source mechanisms ranging between tensile opening and tensile closing, and fracture orientations dominated by the rock fabric which are not always optimally oriented to the regional stress field. The observed source characteristics are expected for events driven by increased pore pressure and reduced friction due to lubrication. On average, deep events show higher stress drop, apparent stress, and rupture velocity than reservoir events. This reflects higher confining stresses with depth, and possibly the release of stored energy in the existing zone of weakness. Deep events are dominated by shear failures, but source characteristics are smaller than for naturally occurring tectonic earthquakes of similar magnitude. Most importantly from a seismic hazard perspective, large earthquakes associated with hydrofracing have lower stress drops than tectonic earthquakes, and thus produce smaller peak ground acceleration and less damage on surface. The largest event recorded in this dataset has a moment magnitude of +2.9 and was felt by field crews in the area. The response

Computer Simulation Model to Train Medical Personnel on Glucose Clamp Procedures.

Science.gov (United States)

Maghoul, Pooya; Boulet, Benoit; Tardif, Annie; Haidar, Ahmad

2017-10-01

A glucose clamp procedure is the most reliable way to quantify insulin pharmacokinetics and pharmacodynamics, but skilled and trained research personnel are required to frequently adjust the glucose infusion rate. A computer environment that simulates glucose clamp experiments can be used for efficient personnel training and development and testing of algorithms for automated glucose clamps. We built 17 virtual healthy subjects (mean age, 25±6 years; mean body mass index, 22.2±3 kg/m 2 ), each comprising a mathematical model of glucose regulation and a unique set of parameters. Each virtual subject simulates plasma glucose and insulin concentrations in response to intravenous insulin and glucose infusions. Each virtual subject provides a unique response, and its parameters were estimated from combined intravenous glucose tolerance test-hyperinsulinemic-euglycemic clamp data using the Bayesian approach. The virtual subjects were validated by comparing their simulated predictions against data from 12 healthy individuals who underwent a hyperglycemic glucose clamp procedure. Plasma glucose and insulin concentrations were predicted by the virtual subjects in response to glucose infusions determined by a trained research staff performing a simulated hyperglycemic clamp experiment. The total amount of glucose infusion was indifferent between the simulated and the real subjects (85±18 g vs. 83±23 g; p=NS) as well as plasma insulin levels (63±20 mU/L vs. 58±16 mU/L; p=NS). The virtual subjects can reliably predict glucose needs and plasma insulin profiles during hyperglycemic glucose clamp conditions. These virtual subjects can be used to train personnel to make glucose infusion adjustments during clamp experiments. Copyright © 2017 Diabetes Canada. Published by Elsevier Inc. All rights reserved.

Deformations and Rotational Ground Motions Inferred from Downhole Vertical Array Observations

Science.gov (United States)

Graizer, V.

2017-12-01

Only few direct reliable measurements of rotational component of strong earthquake ground motions are obtained so far. In the meantime, high quality data recorded at downhole vertical arrays during a number of earthquakes provide an opportunity to calculate deformations based on the differences in ground motions recorded simultaneously at different depths. More than twenty high resolution strong motion downhole vertical arrays were installed in California with primary goal to study site response of different geologic structures to strong motion. Deformation or simple shear strain with the rate γ is the combination of pure shear strain with the rate γ/2 and rotation with the rate of α=γ/2. Deformations and rotations were inferred from downhole array records of the Mw 6.0 Parkfield 2004, the Mw 7.2 Sierra El Mayor (Mexico) 2010, the Mw 6.5 Ferndale area in N. California 2010 and the two smaller earthquakes in California. Highest amplitude of rotation of 0.60E-03 rad was observed at the Eureka array corresponding to ground velocity of 35 cm/s, and highest rotation rate of 0.55E-02 rad/s associated with the S-wave was observed at a close epicentral distance of 4.3 km from the ML 4.2 event in Southern California at the La Cienega array. Large magnitude Sierra El Mayor earthquake produced long duration rotational motions of up to 1.5E-04 rad and 2.05E-03 rad/s associated with shear and surface waves at the El Centro array at closest fault distance of 33.4km. Rotational motions of such levels, especially tilting can have significant effect on structures. High dynamic range well synchronized and properly oriented instrumentation is necessary for reliable calculation of rotations from vertical array data. Data from the dense Treasure Island array near San Francisco demonstrate consistent change of shape of rotational motion with depth and material. In the frequency range of 1-15 Hz Fourier amplitude spectrum of vertical ground velocity is similar to the scaled tilt

Summary evaluation of Yucca Mountain surface transects with implications for downhole sampling. Yucca Mountain Site Characterization Project

International Nuclear Information System (INIS)

Mckenna, S.A.; Rautman, C.A.

1995-06-01

The results of previously completed vertical outcrop sampling transacts are summarized with respect to planning downhole sampling. The summary includes statistical descriptions and descriptions of the spatial variability of the sampled parameters. Descriptions are made on each individual transect, each thermal/mechanical unit and each previously defined geohydrologic unit. Correlations between parameters indicate that saturated hydraulic conductivity is not globally correlated to porosity. The correlation between porosity and saturated hydraulic conductivity is both spatially and lithologically dependent. Currently, there are not enough saturated hydraulic conductivity and sorptivity data to define relationships between these properties and porosity on a unit by unit basis. Also, the Prow Pass member of the Crater Flat Tuff and stratigraphically lower units have gone essentially unsampled in these outcrop transacts. The vertical correlation length for hydrologic properties is not constant across the area of the transacts. The average sample spacing within the transacts ranges from 1.25 to 2.1 meters. It appears that, with the exception of the Topopah Spring member units, a comparable sample spacing will give adequate results in the downhole sampling campaign even with the nonstationarity of the vertical correlation. The properties within the thermal/mechanical units and geohydrologic units of the Topopah Spring member appear to have a spatial correlation range less than or equal to the current sample spacing within these units. For the downhole sampling, a sample spacing of less than 1.0 meters may be necessary within these units

Investigation of the Dynamics of a Clamped-Clamped Microbeam Near the Third Mode Using a Partial Electrode

KAUST Repository

Masri, Karim M.

2014-08-17

We present an investigation of the dynamics of a clamped-clamped microbeam excited electrostatically near its third mode. To maximize the response at the third mode, a partial electrode configuration is utilized. A multi-mode Galerkin method is used to develop a reduced order model (ROM) of the beam. A shooting method to find the periodic motion is utilized to generate frequency response curves. The curves show hardenining behavior and dynamic pull-in. We show that the dynamic amplitude of the partial configuration is higher than that of a full electrode configuration. These results are promising for the use of higher-order modes for mass detection and for ultra sensitive resonant sensors.

Investigation of the Dynamics of a Clamped-Clamped Microbeam Near the Third Mode Using a Partial Electrode

KAUST Repository

Masri, Karim M.; Younis, Mohammad I.

2014-01-01

We present an investigation of the dynamics of a clamped-clamped microbeam excited electrostatically near its third mode. To maximize the response at the third mode, a partial electrode configuration is utilized. A multi-mode Galerkin method is used to develop a reduced order model (ROM) of the beam. A shooting method to find the periodic motion is utilized to generate frequency response curves. The curves show hardenining behavior and dynamic pull-in. We show that the dynamic amplitude of the partial configuration is higher than that of a full electrode configuration. These results are promising for the use of higher-order modes for mass detection and for ultra sensitive resonant sensors.

COMPARISON OF EARLY AND DELAYED UMBILICAL CORD CLAMPING IN THE THIRD STAGE OF LABOUR

Directory of Open Access Journals (Sweden)

Tamara Serdinšek

2015-09-01

Full Text Available Background: Umbilical cord clamping in the third stage of labour is still controversial. Early cord clamping is defined as clamping at 10, 15, 30 or 60 seconds after delivery and delayed as clamping after 60 seconds or at 2-5 minutes after delivery, when the cord stops pulsating or when the placenta is visible within the birth canal. Early clamping is one of the three components of active management of the third stage of labour, which has been used widely in modern obstetrics during the last century. However, in some northern European countries, various parts of the USA and Canada and in developing countries physiological management is preferred.Conclusions: After publication of several trials describing advantages of delayed clamping, this has recently been progressively replacing early clamping. The most important advantages of delayed cord clamping are higher haemoglobin and ferritin levels, higher iron stores, lower incidence of iron deficiency anaemia, better cardiopulmonary adaptation, lower rate of respiratory distress syndrome, and longer duration of early breastfeeding in term neonates, while there is no increase in the incidence of postpartum haemorrhage. Delayed clamping seems to bring some advantages for preterm neonates as well. However, caution is still advised because of the potential adverse effects, especially polycythaemia with hyperviscosity, hyperbilirubinaemia and respiratory distress.

Different methods of hilar clamping during partial nephrectomy: Impact on renal function.

Science.gov (United States)

Lee, Jeong Woo; Kim, Hwanik; Choo, Minsoo; Park, Yong Hyun; Ku, Ja Hyeon; Kim, Hyeon Hoe; Kwak, Cheol

2014-03-01

To evaluate the impact of different hilar clamping methods on changes in renal function after partial nephrectomy. We analyzed the clinical data of 369 patients who underwent partial nephrectomy for a single renal tumor of size ≤4.0 cm and a normal contralateral kidney. Patients were separated into three groups depending on hilar clamping method: non-clamping, cold ischemia and warm ischemia. Estimated glomerular filtration rate was examined at preoperative, nadir and 1 year postoperatively. Percent change in estimated glomerular filtration rate was used as the parameter to assess the renal functional outcome. Percent change in nadir estimated glomerular filtration rate in the non-clamping group was significantly less compared with the cold ischemia and warm ischemia groups (P hilar clamping (both warm ischemia and cold ischemia) were significantly associated with percent change in nadir estimated glomerular filtration rate, but not in 1-year estimated glomerular filtration rate. Non-clamping partial nephrectomy results in a lower percent change in nadir estimated glomerular filtration rate, whereas it carries an estimated glomerular filtration rate change at 1 year that is similar to partial nephrectomy with cold ischemia and warm ischemia. Cold ischemia and warm ischemia provide a similar effect on renal function. Therefore, when hilar clamping is required, minimization of ischemia time is necessary. © 2013 The Japanese Urological Association.

Seismic characteristics of tensile fracture growth induced by hydraulic fracturing

Science.gov (United States)

Eaton, D. W. S.; Van der Baan, M.; Boroumand, N.

2014-12-01

Hydraulic fracturing is a process of injecting high-pressure slurry into a rockmass to enhance its permeability. Variants of this process are used for unconventional oil and gas development, engineered geothermal systems and block-cave mining; similar processes occur within volcanic systems. Opening of hydraulic fractures is well documented by mineback trials and tiltmeter monitoring and is a physical requirement to accommodate the volume of injected fluid. Numerous microseismic monitoring investigations acquired in the audio-frequency band are interpreted to show a prevalence of shear-dominated failure mechanisms surrounding the tensile fracture. Moreover, the radiated seismic energy in the audio-frequency band appears to be a miniscule fraction (<< 1%) of the net injected energy, i.e., the integral of the product of fluid pressure and injection rate. We use a simple penny-shaped crack model as a predictive framework to describe seismic characteristics of tensile opening during hydraulic fracturing. This model provides a useful scaling relation that links seismic moment to effective fluid pressure within the crack. Based on downhole recordings corrected for attenuation, a significant fraction of observed microseismic events are characterized by S/P amplitude ratio < 5. Despite the relatively small aperture of the monitoring arrays, which precludes both full moment-tensor analysis and definitive identification of nodal planes or axes, this ratio provides a strong indication that observed microseismic source mechanisms have a component of tensile failure. In addition, we find some instances of periodic spectral notches that can be explained by an opening/closing failure mechanism, in which fracture propagation outpaces fluid velocity within the crack. Finally, aseismic growth of tensile fractures may be indicative of a scenario in which injected energy is consumed to create new fracture surfaces. Taken together, our observations and modeling provide evidence that

The Investigation of the Corrosion Resistance of the Tension Clamps Skl14

Directory of Open Access Journals (Sweden)

Marek Pětioký

2015-05-01

Full Text Available At the level crossings it is possible to find the problems with the corrosion of the parts of the fastening system. These problems are especially at the rubber level crossings and in the tunnels. As a part of the thesis the problem of the corrosion of the tension clamp Skl14 of the producer Vossloh at the rubber level crossings is examined. For the purposes of the comparison the tension clamps without the corrosion protection and the tension clamps with the corrosion protection KTL were examined. As a first step the corrosion features of the tension clamps Skl14 were solved. The examination was divided into two parts. First part it was the examination according to ČSN EN ISO 9227. The samples of the tension clamps were putted into the corrosion chamber. After 1728 h the results of the corrosion impacts were not satisfied. It was decided for the second step of the examination. It was the immersion in an electrolyte solution. As a result of the paper the corrosion features of the tension clamps without the corrosion protection and with the corrosion protection are compared.

CALIBRATION AND TESTING OF SONIC STIMULATION TECHNOLOGIES

Energy Technology Data Exchange (ETDEWEB)

Roger Turpening; Wayne Pennington; Christopher Schmidt; Sean Trisch

2005-03-01

In conjunction with Baker Atlas Inc. Michigan Technological University devised a system capable of recording the earth motion and pressure due to downhole and surface seismic sources. The essential elements of the system are (1) a borehole test site that will remain constant and is available all the time and for any length of time, (2) a downhole sonde that will itself remain constant and, because of its downhole digitization feature, does not require the wireline or surface recording components to remain constant, and (3) a set of procedures that ensures that the amplitude and frequency parameters of a wide range of sources can be compared with confidence. This system was used to record four seismic sources, three downhole sources and one surface source. A single activation of each of the downhole sources was not seen on time traces above the ambient noise, however, one sweep of the surface source, a small vertical vibrator, was easily seen in a time trace. One of the downhole sources was seen by means of a spike in its spectrum and a second downhole source was clearly seen after correlation and stacking. The surface vibrator produced a peak to peak particle motion signal of approximately 4.5 x 10{sup -5} cm/sec and a peak to peak pressure of approx. 2.5 x 10{sup -7} microPascals at a depth of 1,485 ft. Theoretical advances were made with our partner, Dr. Igor Beresnev at Iowa State University. A theory has been developed to account for the behavior of oil ganglia trapped in pore throats, and their ultimate release through the additional incremental pressure associated with sonic stimulation.

Calibration and Testing of Sonic Stimulation Technologies

Energy Technology Data Exchange (ETDEWEB)

Roger M. Turpening; Wayne D.Pennington

2005-03-31

In conjunction with Baker Atlas Inc. Michigan Technological University devised a system capable of recording the earth motion and pressure due to downhole and surface seismic sources. The essential elements of the system are 1) a borehole test site that will remain constant and is available all the time and for any length of time, 2) a downhole sonde that will itself remain constant and, because of its downhole digitization feature, does not require the wireline or surface recording components to remain constant, and 3) a set of procedures that ensures that the amplitude and frequency parameters of a wide range of sources can be compared with confidence. This system was used to record four seismic sources, three downhole sources and one surface source. A single activation of each of the downhole sources was not seen on time traces above the ambient noise, however, one sweep of the surface source, a small vertical vibrator, was easily seen in a time trace. One of the downhole sources was seen by means of a spike in its spectrum and a second downhole source was clearly seen after correlation and stacking. The surface vibrator produced a peak to peak particle motion signal of approximately 4.5 X 10-5 cm/sec and a peak to peak pressure of approx. 2.5 X 10-7 microPascals at a depth of 1,485 ft. Theoretical advances were made with our partner, Dr. I. Beresnev at Iowa State University. A theory has been developed to account for the behavior of oil ganglia trapped in pore throats, and their ultimate release through the additional incremental pressure associated with sonic stimulation.

Four- year thyroidectomy procedures: Ligasure Vs. clamp & tie

Directory of Open Access Journals (Sweden)

Pazoki AR

2010-01-01

Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: The electrothermal bipolar vessel sealing system is an adjunct to the hemostatic technique, which has been successfully used in many abdominal operation, recently made available to thyroid surgery. The purpose of this was compare the outcomes of new hemostatic technique with traditional method of clamp and tie."n"nMethods: In this retrospective cross-sectional study has been done in surgery's wards of Milad & Rasul- Akram hospitals in Tehran, Iran. During three- year period between 2005-2008 all patients with different kind of pathology that need operation were assessed. Time duration of surgery and hospital stay and post surgery complication in two group, ligasure (n=45 and clamp & tie (n=145 were compared with each others."n"nResults: No difference was seen between two groups in time duration of surgery. Significant difference was seen in hospital stay and complications of surgery. Time of operation in Ligasure group was 132/22 minute and in clamp and tie group was 130/10 minute. There was found significant difference in duration of hospital stay and postoperative complication. Hypocalcemia were seen in two and 24 cases in Ligasure and Clamp & Tie group, respectively (p<0.05. Hospital stay was 2

Preliminary analysis of downhole logging data from ICDP Lake Junin drilling Project, Peru

Science.gov (United States)

Pierdominici, Simona; Kück, Jochem; Rodbell, Donald T.; Abbott, Mark B.

2016-04-01

The International Continental Drilling Programm (ICDP) has supported a scientific drilling campaign in Peru during the summer season 2015. The Lake Junin Drilling Project mainly aims at obtaining high-resolution paleoclimate records from lacustrine sediments to reconstruct the history of the continental records covering the glacial-interglacial cycles. Lake Junín is located at 4000 m a.s.l. in the tropical Andes of Peru, and is characterized by a thick (> 125 m) sediment package deposited at a high rate (0.2 to 1.0 mm yr-1). Lake Junín is one of the few lakes in the tropical Andes that predates the maximum extent of glaciation and is in a geomorphic position to record the waxing and waning of glaciers in nearby cordillera, hence making the lake a key site for the investigation of the Quaternary climate evolution in the inner-tropics of the Southern Hemisphere. Continous coring was performed at three sites in overall 11 boreholes on the lake with at least two overlapping boreholes per site to avoid core gaps. The depth of the boreholes varied between approx. 30 m and 110 m depending on the drill site. The core bit had a bit size of 122.6 mm and yielded a core diameter of 85 mm. Upon completion of coring operations downhole geophysical logging was performed in five of the 11 boreholes (1A, 1C, 1D, 2A and 3B) by the Operational Support Group of ICDP. The main objective was to record in-situ the physical properties of the lacustrine sediments of Lake Junin. Downhole logs provide a powerful tool to fill in information at intervals with core gaps and as depth reference for depth matching of the discontinous cores. Furthermore it will be used for the lithological reconstruction and interpretation. The OSG downhole logging comprised total and spectrum gamma ray, magnetic susceptibility, borehole geometry, temperature, and sonic P-wave velocity. Unstable and collapsing borehole walls made it neccessary to carry out logging in several sections instead of in one run. The

Application of active electrode compensation to perform continuous voltage-clamp recordings with sharp microelectrodes.

Science.gov (United States)

Gómez-González, J F; Destexhe, A; Bal, T

2014-10-01

Electrophysiological recordings of single neurons in brain tissues are very common in neuroscience. Glass microelectrodes filled with an electrolyte are used to impale the cell membrane in order to record the membrane potential or to inject current. Their high resistance induces a high voltage drop when passing current and it is essential to correct the voltage measurements. In particular, for voltage clamping, the traditional alternatives are two-electrode voltage-clamp technique or discontinuous single electrode voltage-clamp (dSEVC). Nevertheless, it is generally difficult to impale two electrodes in a same neuron and the switching frequency is limited to low frequencies in the case of dSEVC. We present a novel fully computer-implemented alternative to perform continuous voltage-clamp recordings with a single sharp-electrode. To reach such voltage-clamp recordings, we combine an active electrode compensation algorithm (AEC) with a digital controller (AECVC). We applied two types of control-systems: a linear controller (proportional plus integrative controller) and a model-based controller (optimal control). We compared the performance of the two methods to dSEVC using a dynamic model cell and experiments in brain slices. The AECVC method provides an entirely digital method to perform continuous recording and smooth switching between voltage-clamp, current clamp or dynamic-clamp configurations without introducing artifacts.

Improved DNA clamps by stacking to adjacent nucleobases

DEFF Research Database (Denmark)

Fatthalla, M.I.; Pedersen, Erik Bjerregaard

2012-01-01

Three or four aromatic rings interconnected by acetylene bridges form a stiff conjugated system with sufficient conformational freedom to make it useful to link together the two strands of a DNA clamp. Upon targeting a ssDNA, the conformational flexibility allows better stacking of the linker...... to the underlying non-planar base triplet in the formed triplex. This type of triplexes has a substantially higher thermal melting temperature which can be further improved by inserting locked nucleic acids (LNAs) in the Hoogsteen part of the clamp. An extremely high sensitivity to mismatches is observed...

DOWNHOLE POWER GENERATION AND WIRELESS COMMUNICATIONS FOR INTELLIGENT COMPLETIONS APPLICATIONS

Energy Technology Data Exchange (ETDEWEB)

Paul Tubel

2003-10-14

The fourth quarter of the project was dedicated to the manufacturing of the mechanical system for wireless communications and the power generation module and inspection pre assembly of the mechanical components. Another emphasis for the quarter was the development of filter control and signal detection software. The tasks accomplished during this report period were: (1) Dimensional issues were resolved and revised drawings for manufacturing of the wireless communications gauge and power generator were completed and sent to a machine shop for manufacturing. (2) Finalized the requirements and fittings and connections for testing the tool in the Halliburton flow loop. (3) The new acoustic generator was manufactured successfully and it was delivered during this quarter. The assembly will be outsourced for plastic coating in preparation for hostile environment use. (4) The acoustic two-way communications development continued to progress. The real time firmware for the surface system was developed and the processor was able to detect and process the data frame transmitted from downhole. The analog section of the tool was also developed and it is being tested for filtering capabilities and signal detection and amplification. (5) The new transformer to drive the acoustic generator assembly was manufactured and was successfully tested. Spring mandrel design showed increased acoustic output on the pipe and was implemented. (6) PCBA board carrier with board set was tested for function and fit and is 100% complete. (7) Filter control software is complete and software to allow modification of communication parameters dynamically is 50% complete. (8) All mechanical parts to assemble the wireless gauge and power generator have been received and verified to be within specification. (9) Acoustic generator has been assembled in the tool mandrel and tested successfully. (10) The circuit required to harvest the power generated downhole has been designed and the power generator

Lithostratigraphy from downhole logs in Hole AND-1B, Antarctica

Science.gov (United States)

Williams, Trevor; Morin, Roger H.; Jarrard, Richard D.; Jackolski, Chris L.; Henrys, Stuart A.; Niessen, Frank; Magens, Diana; Kuhn, Gerhard; Monien, Donata; Powell, Ross D.

2012-01-01

The ANDRILL (Antarctic Drilling Project) McMurdo Ice Shelf (MIS) project drilled 1285 m of sediment in Hole AND–1B, representing the past 12 m.y. of glacial history. Downhole geophysical logs were acquired to a depth of 1018 mbsf (meters below seafloor), and are complementary to data acquired from the core. The natural gamma radiation (NGR) and magnetic susceptibility logs are particularly useful for understanding lithological and paleoenvironmental change at ANDRILL McMurdo Ice Shelf Hole AND–1B. NGR logs cover the entire interval from the seafloor to 1018 mbsf, and magnetic susceptibility and other logs covered the open hole intervals between 692 and 1018 and 237–342 mbsf. In the upper part of AND–1B, clear alternations between low and high NGR values distinguish between diatomite (lacking minerals containing naturally radioactive K, U, and Th) and diamictite (containing K-bearing clays, K-feldspar, mica, and heavy minerals). In the lower open hole logged section, NGR and magnetic susceptibility can also distinguish claystones (rich in K-bearing clay minerals, relatively low in magnetite) and diamictites (relatively high in magnetite). Sandstones can be distinguished by their high resistivity values in AND–1B. On the basis of these three downhole logs, diamictite, claystones, and sandstones can be predicted correctly for 74% of the 692–1018 mbsf interval. The logs were then used to predict facies for the 6% of this interval that was unrecovered by coring. Given the understanding of the physical property characteristics of different facies, it is also possible to identify subtle changes in lithology from the physical properties and help refine parts of the lithostratigraphy, for example, the varying terrigenous content of diatomites and the transitions from subice diamictite to open-water diatomite.

Formal Design Review Foot Clamp Modification

International Nuclear Information System (INIS)

OTEN, T.C.

2000-01-01

This report documents the Design Review performed for the foot clamp modification. The report documents the acceptability of the design, identifies the documents that were reviewed, the scope of the review and the members of the review team

Novel Downhole Electromagnetic Flowmeter for Oil-Water Two-Phase Flow in High-Water-Cut Oil-Producing Wells.

Science.gov (United States)

Wang, Yanjun; Li, Haoyu; Liu, Xingbin; Zhang, Yuhui; Xie, Ronghua; Huang, Chunhui; Hu, Jinhai; Deng, Gang

2016-10-14

First, the measuring principle, the weight function, and the magnetic field of the novel downhole inserted electromagnetic flowmeter (EMF) are described. Second, the basic design of the EMF is described. Third, the dynamic experiments of two EMFs in oil-water two-phase flow are carried out. The experimental errors are analyzed in detail. The experimental results show that the maximum absolute value of the full-scale errors is better than 5%, the total flowrate is 5-60 m³/d, and the water-cut is higher than 60%. The maximum absolute value of the full-scale errors is better than 7%, the total flowrate is 2-60 m³/d, and the water-cut is higher than 70%. Finally, onsite experiments in high-water-cut oil-producing wells are conducted, and the possible reasons for the errors in the onsite experiments are analyzed. It is found that the EMF can provide an effective technology for measuring downhole oil-water two-phase flow.

Novel Downhole Electromagnetic Flowmeter for Oil-Water Two-Phase Flow in High-Water-Cut Oil-Producing Wells

Directory of Open Access Journals (Sweden)

Yanjun Wang

2016-10-01

Full Text Available First, the measuring principle, the weight function, and the magnetic field of the novel downhole inserted electromagnetic flowmeter (EMF are described. Second, the basic design of the EMF is described. Third, the dynamic experiments of two EMFs in oil-water two-phase flow are carried out. The experimental errors are analyzed in detail. The experimental results show that the maximum absolute value of the full-scale errors is better than 5%, the total flowrate is 5–60 m3/d, and the water-cut is higher than 60%. The maximum absolute value of the full-scale errors is better than 7%, the total flowrate is 2–60 m3/d, and the water-cut is higher than 70%. Finally, onsite experiments in high-water-cut oil-producing wells are conducted, and the possible reasons for the errors in the onsite experiments are analyzed. It is found that the EMF can provide an effective technology for measuring downhole oil-water two-phase flow.

Molecular mechanism of DNA replication-coupled inactivation of the initiator protein in Escherichia coli: interaction of DnaA with the sliding clamp-loaded DNA and the sliding clamp-Hda complex.

Science.gov (United States)

Su'etsugu, Masayuki; Takata, Makoto; Kubota, Toshio; Matsuda, Yusaku; Katayama, Tsutomu

2004-06-01

In Escherichia coli, the ATP-DnaA protein initiates chromosomal replication. After the DNA polymerase III holoenzyme is loaded on to DNA, DnaA-bound ATP is hydrolysed in a manner depending on Hda protein and the DNA-loaded form of the DNA polymerase III sliding clamp subunit, which yields ADP-DnaA, an inactivated form for initiation. This regulatory DnaA-inactivation represses extra initiation events. In this study, in vitro replication intermediates and structured DNA mimicking replicational intermediates were first used to identify structural prerequisites in the process of DnaA-ATP hydrolysis. Unlike duplex DNA loaded with sliding clamps, primer RNA-DNA heteroduplexes loaded with clamps were not associated with DnaA-ATP hydrolysis, and duplex DNA provided in trans did not rescue this defect. At least 40-bp duplex DNA is competent for the DnaA-ATP hydrolysis when a single clamp was loaded. The DnaA-ATP hydrolysis was inhibited when ATP-DnaA was tightly bound to a DnaA box-bearing oligonucleotide. These results imply that the DnaA-ATP hydrolysis involves the direct interaction of ATP-DnaA with duplex DNA flanking the sliding clamp. Furthermore, Hda protein formed a stable complex with the sliding clamp. Based on these, we suggest a mechanical basis in the DnaA-inactivation that ATP-DnaA interacts with the Hda-clamp complex with the aid of DNA binding. Copyright Blackwell Publishing Limited

The design and simulation of new downhole vibration device about acoustic oil recovery technology

Directory of Open Access Journals (Sweden)

Yongjun Hou

2015-09-01

Full Text Available More and more oilfields are using acoustic technology to enhance oil recovery. In order to know the mechanism of acoustic oil recovery technology, the sound radiator of a new downhole vibration device is modeled and analyzed. Based on the theoretical background, this paper firstly analyzes the acoustic mechanism for the oil reservoir and then makes a acoustic response analysis on the sound radiator model for frequency and time-domain investigation by using professional acoustic simulation software–LMS Virtual.lab Acoustics, finally calculates the acoustic transmission loss in the downhole oil reservoir. The research reveals that firstly, acoustic waves have influences on the oil & water fluidity in the oil reservoir, the oil pressure gradient and the interfacial tension of capillary; secondly, the acoustic radiation power and sound pressure of field point attain a peak on the natural frequency of the sound radiator; thirdly, with the acoustic impact, the sound pressure of oil reservoir would fluctuate so as to improve the oil recovery ratio; the last but not the least one is both the sound pressure of oil reservoir point and the transmission loss of rock have a positive correlation with the vibration frequency. Therefore, it is of great importance for the research of vibration frequency and structure optimization of sound radiator.

Clamp wins pipe repair prize

Energy Technology Data Exchange (ETDEWEB)

Anon.

2001-04-01

This paper describes the permanent pipeline repair system, developed by Tekmar, which is powered by seawater hydraulics and is easily installed and tested by any workclass remotely operated vehicle (rov). Details are given of the two main components of the system, namely, the diverless high pressure split repair clamp and the rov-operated tool to install it.

A Hybrid Model for Safety Pharmacology on an Automated Patch Clamp Platform: Using Dynamic Clamp to Join iPSC-Derived Cardiomyocytes and Simulations of Ik1 Ion Channels in Real-Time

Directory of Open Access Journals (Sweden)

Birgit Goversen

2018-01-01

Full Text Available An important aspect of the Comprehensive In Vitro Proarrhythmia Assay (CiPA proposal is the use of human stem cell-derived cardiomyocytes and the confirmation of their predictive power in drug safety assays. The benefits of this cell source are clear; drugs can be tested in vitro on human cardiomyocytes, with patient-specific genotypes if needed, and differentiation efficiencies are generally excellent, resulting in a virtually limitless supply of cardiomyocytes. There are, however, several challenges that will have to be surmounted before successful establishment of hSC-CMs as an all-round predictive model for drug safety assays. An important factor is the relative electrophysiological immaturity of hSC-CMs, which limits arrhythmic responses to unsafe drugs that are pro-arrhythmic in humans. Potentially, immaturity may be improved functionally by creation of hybrid models, in which the dynamic clamp technique joins simulations of lacking cardiac ion channels (e.g., IK1 with hSC-CMs in real-time during patch clamp experiments. This approach has been used successfully in manual patch clamp experiments, but throughput is low. In this study, we combined dynamic clamp with automated patch clamp of iPSC-CMs in current clamp mode, and demonstrate that IK1 conductance can be added to iPSC-CMs on an automated patch clamp platform, resulting in an improved electrophysiological maturity.

Analytical-numerical solution for the trajectory of seismic rays in media with vertical heterogeneity

International Nuclear Information System (INIS)

Imhof, Armando Luis; Calvo, Carlos Adolfo; Moyano, Amalia; Sanchez, Manuel

2015-01-01

A determined curve path is followed by the propagation of seismic waves generated in emitters and detected in receivers by the principle of minimum time of Fermat. An ordinary differential equation is derived from the application of the calculation of variations. Due to the compaction of the terrain, the speed usually increases with depth. The experimental laws for each soil have led to this variation leading to a numerical resolution. The adjustment of experimental speed data by an exponential function; the analytical integration of the differential equation and the numerical determination of the integration constants are studied. A geophysical method such as up-hole or down-hole has determined the experimental data. Its main application is centered in the validation of numerical models of curved trajectories. Then time of first arrivals through tomographic algorithms for detection and modeling of anomalies in the first 12 m depth. (author) [es

A High Step-Down Interleaved Buck Converter with Active-Clamp Circuits for Wind Turbines

Directory of Open Access Journals (Sweden)

Chih-Lung Shen

2012-12-01

Full Text Available In this paper, a high step-down interleaved buck coupled-inductor converter (IBCC with active-clamp circuits for wind energy conversion has been studied. In high step-down voltage applications, an IBCC can extend duty ratio and reduce voltage stresses on active switches. In order to reduce switching losses of active switches to improve conversion efficiency, a IBCC with soft-switching techniques is usually required. Compared with passive-clamp circuits, the IBCC with active-clamp circuits have lower switching losses and minimum ringing voltage of the active switches. Thus, the proposed IBCC with active-clamp circuits for wind energy conversion can significantly increase conversion efficiency. Finally, a 240 W prototype of the proposed IBCC with active-clamp circuits was built and implemented. Experimental results have shown that efficiency can reach as high as 91%. The proposed IBCC with active-clamp circuits is presented in high step-down voltage applications to verify the performance and the feasibility for energy conversion of wind turbines.

Natural Vibration Analysis of Clamped Rectangular Orthotropic Plates

Science.gov (United States)

dalaei, m.; kerr, a. d.

The natural vibrations of clamped rectangular orthotropic plates are analyzed using the extended Kantorovich method. The developed iterative scheme converges very rapidly to the final result. The obtained natural frequencies are evaluated for a square plate made of Kevlar 49 Epoxy and the obtained results are compared with those published by Kanazawa and Kawai, and by Leissa. The agreement was found to be very close. As there are no exact analytical solutions for clamped rectangular plates, the generated closed form expression for the natural modes, and the corresponding natural frequencies, are very suitable for use in engineering analyses.

Effect of non-ideal clamping shape on the resonance frequencies of silicon nanocantilevers

Energy Technology Data Exchange (ETDEWEB)

Guillon, Samuel; Saya, Daisuke; Mazenq, Laurent; Nicu, Liviu [CNRS, LAAS, 7 Avenue du Colonel Roche, F-31077 Toulouse Cedex 4 (France); Perisanu, Sorin; Vincent, Pascal [LPMCN, Universite Claude Bernard Lyon 1 et CNRS, 43 boulevard du 11 novembre 1918, 69622 Villeurbanne Cedex (France); Lazarus, Arnaud; Thomas, Olivier, E-mail: sguillon@laas.fr [Structural Mechanics and Coupled Systems Laboratory, Conservatoire National des Arts et Metiers, 2 rue Conte, 75003 Paris (France)

2011-06-17

In this paper, we investigate the effects of non-ideal clamping shapes on the dynamic behavior of silicon nanocantilevers. We fabricated silicon nanocantilevers using silicon on insulator (SOI) wafers by employing stepper ultraviolet (UV) lithography, which permits a resolution of under 100 nm. The nanocantilevers were driven by electrostatic force inside a scanning electron microscope (SEM). Both lateral and out-of-plane resonance frequencies were visually detected with the SEM. Next, we discuss overhanging of the cantilever support and curvature at the clamping point in the silicon nanocantilevers, which generally arises in the fabrication process. We found that the fundamental out-of-plane frequency of a realistically clamped cantilever is always lower than that for a perfectly clamped cantilever, and depends on the cantilever width and the geometry of the clamping point structure. Using simulation with the finite-elements method, we demonstrate that this discrepancy is attributed to the particular geometry of the clamping point (non-zero joining curvatures and a flexible overhanging) that is obtained in the fabrication process. The influence of the material orthotropy is also investigated and is shown to be negligible.

Strong seismic ground motion propagation

International Nuclear Information System (INIS)

Seale, S.; Archuleta, R.; Pecker, A.; Bouchon, M.; Mohammadioun, G.; Murphy, A.; Mohammadioun, B.

1988-10-01

At the McGee Creek, California, site, 3-component strong-motion accelerometers are located at depths of 166 m, 35 m and 0 m. The surface material is glacial moraine, to a depth of 30.5 m, overlying homfels. Accelerations were recorded from two California earthquakes: Round Valley, M L 5.8, November 23, 1984, 18:08 UTC and Chalfant Valley, M L 6.4, July 21, 1986, 14:42 UTC. By separating out the SH components of acceleration, we were able to determine the orientations of the downhole instruments. By separating out the SV component of acceleration, we were able to determine the approximate angle of incidence of the signal at 166 m. A constant phase velocity Haskell-Thomson model was applied to generate synthetic SH seismograms at the surface using the accelerations recorded at 166 m. In the frequency band 0.0 - 10.0 Hz, we compared the filtered synthetic records to the filtered surface data. The onset of the SH pulse is clearly seen, as are the reflections from the interface at 30.5 m. The synthetic record closely matches the data in amplitude and phase. The fit between the synthetic accelerogram and the data shows that the seismic amplification at the surface is a result of the contrast of the impedances (shear stiffnesses) of the near surface materials

Clamped end conditions and cross section deformation in the finite element absolute nodal coordinate formulation

International Nuclear Information System (INIS)

Hussein, Bassam A.; Weed, David; Shabana, Ahmed A.

2009-01-01

In the finite element absolute nodal coordinate formulation (ANCF), the elimination of the relative translations and rotations at a point does not necessarily define a fully clamped joint, particularly in the case of fully parameterized ANCF finite elements that allow for the deformation of the cross section. In this investigation, the formulations and results of two different sets of clamped end conditions that define two different joints are compared. The first joint, called the partially clamped joint, eliminates only the translations and rotations at a point on the cross section. The second joint, called the fully clamped joint, eliminates all the translation, rotation and deformation degrees of freedom at a point on the cross section. The kinematic equations that define the partially and fully clamped joints are developed, and the dynamic equations used in the comparative numerical study presented in this paper are shown. As discussed in this investigation, the fully clamped joint does not allow for the deformation of the cross section at the joint node since the gradient vectors remain orthogonal unit vectors. The partially clamped joint, on the other hand, allows for the deformation of the cross section. Nanson's formula is used as a measure of the deformation of the cross section in the case of the partially clamped joint. A very flexible pendulum that has a rigid body attached to its free end is used to compare the results of the partially and fully clamped joints. The numerical results obtained using this very flexible pendulum example show that, while the type of joint (partially or fully clamped) does not significantly affect the gross reference motion of the system, there are fundamental differences between the two joints since the partially clamped joint allows for the cross section deformations at the joint node

Role of the Checkpoint Clamp in DNA Damage Response

Directory of Open Access Journals (Sweden)

Mihoko Kai

2013-01-01

Full Text Available DNA damage occurs during DNA replication, spontaneous chemical reactions, and assaults by external or metabolism-derived agents. Therefore, all living cells must constantly contend with DNA damage. Cells protect themselves from these genotoxic stresses by activating the DNA damage checkpoint and DNA repair pathways. Coordination of these pathways requires tight regulation in order to prevent genomic instability. The checkpoint clamp complex consists of Rad9, Rad1 and Hus1 proteins, and is often called the 9-1-1 complex. This PCNA (proliferating cell nuclear antigen-like donut-shaped protein complex is a checkpoint sensor protein that is recruited to DNA damage sites during the early stage of the response, and is required for checkpoint activation. As PCNA is required for multiple pathways of DNA metabolism, the checkpoint clamp has also been implicated in direct roles in DNA repair, as well as in coordination of the pathways. Here we discuss roles of the checkpoint clamp in DNA damage response (DDR.

Three-dimensional renal CT angiography for guiding segmental renal artery clamping during laparoscopic partial nephrectomy

International Nuclear Information System (INIS)

Xu, Yi; Shao, Pengfei; Zhu, Xiaomei; Lv, Qiang; Liu, Wangyan; Xu, Hai; Zhu, Yinsu; Yang, Guangyu; Tang, Lijun; Yin, Changjun

2013-01-01

Aim: To evaluate the effectiveness of three-dimensional (3D) renal computed tomography angiography (CTA) in guiding segmental renal artery clamping during laparoscopic partial nephrectomy (LPN). Materials and methods: Forty-three patients with renal tumours undergoing renal CTA before LPN were retrospectively enrolled in this study. 3D arteriogram reconstructed images were created to identify the renal tumour-supplying arteries. The number and location of these targeted vessels were annotated on 3D images preoperatively and compared with the clamped vessels during LPN. The consistency between target vessels annotated at CTA and clamped arteries at LPN was compared both using a patient-based analysis and vessel-based analysis. The χ 2 test was applied to analyse the influence of tumour size, location, and growth pattern on the number of clamped segmental renal branches. Results: On patient-based analysis, the number of targeted vessels was consistent with the clamped vessels during LPN in 33 of 43 patients. On vessel-based analysis, 56 of 65 target vessels annotated at CTA were clamped during LPN. More segmental renal branches (p = 0.04) were clamped in patients with tumours of larger size. Tumour location and growth pattern had no association with the number of clamped segmental branches during LPN. Conclusion: High-quality CTA images and 3D reconstruction images can detect detailed information of tumour-supplying arteries to renal tumours. 3D renal CTA is an effective way to guide segmental renal artery clamping during LPN

Implementation of a fast 16-Bit dynamic clamp using LabVIEW-RT.

Science.gov (United States)

Kullmann, Paul H M; Wheeler, Diek W; Beacom, Joshua; Horn, John P

2004-01-01

The dynamic-clamp method provides a powerful electrophysiological tool for creating virtual ionic conductances in living cells and studying their influence on membrane potential. Here we describe G-clamp, a new way to implement a dynamic clamp using the real-time version of the Lab-VIEW programming environment together with a Windows host, an embedded microprocessor that runs a real-time operating system and a multifunction data-acquisition board. The software includes descriptions of a fast voltage-dependent sodium conductance, delayed rectifier, M-type and A-type potassium conductances, and a leak conductance. The system can also read synaptic conductance waveforms from preassembled data files. These virtual conductances can be reliably implemented at speeds < or =43 kHz while simultaneously saving two channels of data with 16-bit precision. G-clamp also includes utilities for measuring current-voltage relations, synaptic strength, and synaptic gain. Taking an approach built on a commercially available software/hardware platform has resulted in a system that is easy to assemble and upgrade. In addition, the graphical programming structure of LabVIEW should make it relatively easy for others to adapt G-clamp for new experimental applications.

Design, Installation, and Monitoring of a New Downhole Heat Exchanger

Energy Technology Data Exchange (ETDEWEB)

Chiasson, A.D.; G.G. Culver (Geo-Heat Center, Oregon Institute of Technology, Klamath Falls, OR, USA); Favata, D. (Alternative Geothermal Solutions, Oklahoma City, OK, USA); Keiffer, S. (Facilities Services, Oregon Institute of Technology, Klamath Falls, OR, USA)

2005-01-01

The downhole heat exchanger (DHE) is used to provide space heating and domestic hot water from a single geothermal well. The most common construction of DHEs has been black iron, which is subject to failure by corrosion. This paper describes the design, installation, and monitoring of a new type of DHE constructed of cross-linked polyethylene plastic (PEX), a material known for its relatively high temperature and pressure rating, durability, and chemical resistance. The PEX DHE was installed as a retrofit at a residence in Klamath Falls, OR and a data logger was used to record system temperatures at 5-minute intervals for the 2004-2005 heating season. Observations thus far show the PEX assembly to be an acceptable DHE.

Locoregional Anesthesia for Carotid Endarterectomy: Identification of Patients with Intolerance to Cross-Clamping.

Science.gov (United States)

Dellaretti, Marcos; de Vasconcelos, Laura T; Dourado, Jules; de Souza, Renata F; Fontoura, Renato R; de Sousa, Atos A

2016-03-01

During carotid endarterectomy (CEA), carotid cross-clamping is performed to allow for artery incision and plaque removal. A small subgroup of patients can tolerate carotid occlusion for only a few seconds, if at all, without presenting neurologic deficit. These patients are described as having ''cross-clamp intolerance.'' The purpose of this study was to demonstrate the safety of locoregional anesthesia in identifying patients with cross-clamp intolerance and factors associated with this condition. From August 2008 to May 2010, 115 consecutive patients were submitted to CEA under locoregional anesthesia at the Santa Casa de Belo Horizonte; the procedure was performed by the main author. Patients who showed intolerance to internal carotid artery (ICA) occlusion for intolerance. Among the 115 participating patients, 9.6% (11 patients) showed intolerance to ICA occlusion and developed deficits in intolerance). The factor that was associated with cross-clamp intolerance was the mean degree of contralateral carotid stenosis, which was 57.5% for those who presented intolerance and 27.8% for those who tolerated ICA occlusion. Locoregional anesthesia is a safe method for identifying patients with cross-clamp intolerance. Patients with cross-clamp intolerance present contralateral stenosis that is greater on average than patients who readily tolerate carotid artery occlusion. Copyright © 2016 Elsevier Inc. All rights reserved.

Geoelectric Monitoring of geological CO2 storage at Ketzin, Germany (CO2SINK project): Downhole and Surface-Downhole measurements

Science.gov (United States)

Kiessling, D.; Schuett, H.; Schoebel, B.; Krueger, K.; Schmidt-Hattenberger, C.; Schilling, F.

2009-04-01

images of the true resistivity distribution in the reservoir, which reflects the extent of the CO2 plume. The resistivity data provide information about the saturation state of the reservoir independently of seismic methods. Base data sets have been measured prior to the CO2 injection; monitoring data sets are registered while CO2 is being injected. Using combined 3D surface-downhole measurements (realized in cooperation with University of Leipzig) we got in addition an indication for effects of anisotropy in CO2 migration. We present an overview of the electrode installation, first examples for baseline and monitoring datasets and the corresponding tomograms that show indications of the CO2 migration.

Disposal of oil cuttings by downhole fracturing injections : slurry product specifications issues

International Nuclear Information System (INIS)

Radzuan Junin

1994-01-01

The technique of using on-site injection of oil contaminated drill cuttings is attracting considerable attention as a cost effective means of complying with environmental legislation concerning discharges of drilling wastes. The slurrification and injection of oil based cuttings into a casing annulus, a process developed in 1989 by a major oil and gas producer/ operator, has proven to be a significant step toward reduction of such environmental waste. This paper discusses the development of the cuttings reinjection, slurrification, slurry properties and benefits of quality slurry, and behaviour of solid laden slurries in a fracture in conjunction with down-hole disposal operations

Artifactual voltage response recorded from hair cells with patch-clamp amplifiers.

Science.gov (United States)

Masetto, S; Weng, T; Valli, P; Correia, M J

1999-06-23

Patch-clamp amplifiers (PCAs) are commonly used to characterize voltage- and current-clamp responses in the same cell. However, the cell membrane voltage response can be severely distorted by PCAs working in the current-clamp mode. Here we compare the voltage response of pigeon semicircular canal hair cells in situ, recorded with two different PCAs, and with a classic microelectrode bridge amplifier (BA). We found that the voltage response of hair cells recorded with PCAs differed significantly from that recorded with the BA. The true hair cell membrane voltage response to positive current steps was characterized by a strongly damped oscillation, whose frequency and duration depended on hair cell location in the sensory crista ampullaris.

Dynamic assembly of Hda and the sliding clamp in the regulation of replication licensing.

Science.gov (United States)

Kim, Jin S; Nanfara, Michael T; Chodavarapu, Sundari; Jin, Kyeong S; Babu, Vignesh M P; Ghazy, Mohamed A; Chung, Scisung; Kaguni, Jon M; Sutton, Mark D; Cho, Yunje

2017-04-20

Regulatory inactivation of DnaA (RIDA) is one of the major regulatory mechanisms of prokaryotic replication licensing. In RIDA, the Hda-sliding clamp complex loaded onto DNA directly interacts with adenosine triphosphate (ATP)-bound DnaA and stimulates the hydrolysis of ATP to inactivate DnaA. A prediction is that the activity of Hda is tightly controlled to ensure that replication initiation occurs only once per cell cycle. Here, we determined the crystal structure of the Hda-β clamp complex. This complex contains two pairs of Hda dimers sandwiched between two β clamp rings to form an octamer that is stabilized by three discrete interfaces. Two separate surfaces of Hda make contact with the β clamp, which is essential for Hda function in RIDA. The third interface between Hda monomers occludes the active site arginine finger, blocking its access to DnaA. Taken together, our structural and mutational analyses of the Hda-β clamp complex indicate that the interaction of the β clamp with Hda controls the ability of Hda to interact with DnaA. In the octameric Hda-β clamp complex, the inability of Hda to interact with DnaA is a novel mechanism that may regulate Hda function. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

The Effect of an Added Mass on the Frequency Shifts of a Clamped-Clamped Microbeam for Bio-Mass Detection

KAUST Repository

Bouchaala, Adam M.

2016-12-05

We present analytical formulations to calculate the induced resonance frequency shifts of electrically actuated clamped-clamped microbeams due to an added mass. Based on the Euler-Bernoulli beam theory, we investigate the linear dynamic responses of the beams added masses, which are modeled as discrete point masses. Analytical expressions based on perturbation techniques and a one-mode Galerkin approximation are developed to calculate accurately the frequency shifts under a DC voltage as a function of the added mass and position. The analytical results are compared to numerical solution of the eigenvalue problem. Results are shown for the fundamental as well as the higher-order modes of the beams. The results indicate a significant increase in the frequency shift, and hence the sensitivity of detection, when scaling down to nano scale and using higher-order modes.

The Effect of an Added Mass on the Frequency Shifts of a Clamped-Clamped Microbeam for Bio-Mass Detection

KAUST Repository

Bouchaala, Adam M.; Nayfeh, Ali H.; Younis, Mohammad I.

2016-01-01

We present analytical formulations to calculate the induced resonance frequency shifts of electrically actuated clamped-clamped microbeams due to an added mass. Based on the Euler-Bernoulli beam theory, we investigate the linear dynamic responses of the beams added masses, which are modeled as discrete point masses. Analytical expressions based on perturbation techniques and a one-mode Galerkin approximation are developed to calculate accurately the frequency shifts under a DC voltage as a function of the added mass and position. The analytical results are compared to numerical solution of the eigenvalue problem. Results are shown for the fundamental as well as the higher-order modes of the beams. The results indicate a significant increase in the frequency shift, and hence the sensitivity of detection, when scaling down to nano scale and using higher-order modes.

Holy grail: Pioneering acoustic telemetry technology set to revolutionize downhole communication

Energy Technology Data Exchange (ETDEWEB)

Greenaway, R.

2003-12-01

Acoustic telemetry, a faster and more efficient downhole-to-surface-communication technology, is the latest development in downhole communication systems. The system has been developed by Extreme Engineering Limited of Calgary, led by Derek Logan, founder and one-time senior vice-president of Ryan Energy Technologies that developed the original measurement -while-drilling (MWD) and logging-while-drilling )LWD) tools. The company predicts that acoustic telemetry will cause a massive transformation of the drilling industry in Western Canada once the technology is commercialized. Conventional MWD techniques, based on mud-pulse technology, have been industry standard since the 1970s, but mud-pulse technology is now considered extremely slow. In the 1980s industry came up electromagnetic telemetry, as an alternative to mud-pulse. Today, the need to transmit ever more data, the need for a faster communications system and greater wellbore control, has become even more pressing. Logan believes that acoustic technology is the answer. It is not only capable of transmitting data 20 to 30 times faster than mud-pulse telemetries, it can also communicate massive amounts of data. It can be used in drilling, completion production, drillstem testing, frac monitoring and any other wellbore process requiring wireless real-time telemetry. Acoustic telemetry is also the only wireless system that can perform MWD and LWD in offshore underbalanced drilling. Notwithstanding its great promise, Extreme Engineering Limited had considerable difficulty raising funds for developing and commercializing XAcT (the trade name for acoustic telemetry). Prospects are reported to have been substantially improved by recent infusion of funds by the federal Industrial Research Assistance Program (IRAP) , and XAcT's recognition by R and D Magazine with one of the R and D 100 awards for 2003. 3 figs.

Early identification of hERG liability in drug discovery programs by automated patch clamp

Directory of Open Access Journals (Sweden)

Timm eDanker

2014-09-01

Full Text Available Blockade of the cardiac ion channel coded by hERG can lead to cardiac arrhythmia, which has become a major concern in drug discovery and development. Automated electrophysiological patch clamp allows assessment of hERG channel effects early in drug development to aid medicinal chemistry programs and has become routine in pharmaceutical companies. However, a number of potential sources of errors in setting up hERG channel assays by automated patch clamp can lead to misinterpretation of data or false effects being reported. This article describes protocols for automated electrophysiology screening of compound effects on the hERG channel current. Protocol details and the translation of criteria known from manual patch clamp experiments to automated patch clamp experiments to achieve good quality data are emphasized. Typical pitfalls and artifacts that may lead to misinterpretation of data are discussed. While this article focuses on hERG channel recordings using the QPatch (Sophion A/S, Copenhagen, Denmark technology, many of the assay and protocol details given in this article can be transferred for setting up different ion channel assays by automated patch clamp and are similar on other planar patch clamp platforms.

Three-dimensional site response at KiK-net downhole arrays

Science.gov (United States)

Thompson, Eric M.; Tanaka, Yasuo; Baise, Laurie G.; Kayen, Robert E.

2010-01-01

Ground motions at two Kiban-Kyoshin Network (KiK-net) strong motion downhole array sites in Hokkaido, Japan (TKCH08 in Taiki and TKCH05 in Honbetsu) illustrate the importance of three-dimensional (3D) site effects. These sites recorded the M8.0 2003 Tokachi-Oki earthquake, with recorded accelerations above 0.4 g at both sites as well as numerous ground motions from smaller events. Weak ground motions indicate that site TKCH08 is well modeled with the assumption of plane SH waves traveling through a 1D medium (SH1D), while TKCH05 is characteristic of a poor fit to the SH1D theoretical response. We hypothesized that the misfit at TKCH05results from the heterogeneity of the subsurface. To test this hypothesis, we measured four S-wave velocity profiles in the vicinity (KiK-net site pair is ideal for assessing the relative importance of 3D site effects and nonlinear site effects. The linear ground motions at TKCH05 isolate the 3D site effects, as we hypothesized from the linear ground motions and confirmed with our subsequent SASW surveys. The Tokachi-Oki time history at TKCH08 isolates the effects of nonlinearity from spatial heterogeneity because the 3D effects are negligible. The Tokachi-Oki time history at TKCH05 includes both nonlinear and 3D site effects. Comparisons of the accuracy of the SH1D model predictions of these surface time histories from the downhole time histories indicates that the 3D site effects are at least as important as nonlinear effects in this case. The errors associated with the assumption of a 1D medium and 1D wave propagation will be carried into a nonlinear analysis that relies on these same assumptions. Thus, the presence of 3D effects should be ruled out prior to a 1D nonlinear analysis. The SH1D residuals show that 3D effects can be mistaken for nonlinear effects.

Downhole success : back to the future

Energy Technology Data Exchange (ETDEWEB)

Sherman, J. [Halliburton Energy Services, Calgary, AB (Canada)

2002-07-01

This Power Point presentation included several viewgraphs depicting the difference that technology makes for exploration success. In particular, it refers to the impact that information technology and computers have had in increasing our knowledge base of the subsurface through measurement while drilling (MWD) data and logging while drilling (LWD) data. Computers have made it possible to model Darcy's Law of fluid flow through porous media along with Moore's Law. Onshore control centres make it possible to manage assets, plan preventive maintenance, and continuously monitor safety and environmental compliance. The paper described the key components of the NOW Field as being 4-D seismic, seismic while drilling, intelligent wells, remote operations, visualization technology, forecasting, subsurface models, and data hubs used to build a subsurface model. tabs., figs.

Downhole television (DHTV) applications in borehole plugging

International Nuclear Information System (INIS)

Christensen, C.L.; Statler, R.D.; Peterson, E.W.

1980-05-01

The Borehole Plugging (BHP) Program is a part of the Sandia experimental program to support the Waste Isolation Pilot Plant (WIPP). The Sandia BHP program is an Office of Nuclear Waste Isolation (ONWI)-funded program designed to provide inputs to the generic plugging program while simultaneously acquiring WIPP-specific data. For this reason a close liaison is maintained between the Sandia WIPP project and the ONWI generic program. Useful technology developed within the Sandia BHP to support WIPP is made available and considered for further development and application to the generic Borehole Plugging and Repository Sealing Program at ONWI. The purpose of this report is to illustrate the usefulness of downhole television (DHTV) observations of a borehole to plan plugging operations. An indication of the wellbore conditions observed is provided. The equipment and setup procedure used in the evaluation of AEC-7 for the Bell Canyon test series are illustrated. A sequence of pictures at various depths as the DHTV rig is lowered through the wellbore is presented. Sample photographs taken with both dry and underwater lamps for illumination are included. The caliper logs for the same depth are included for comparison. General comments are provided on the illustrations

Finite element analysis on factors influencing the clamping force in an electrostatic chuck

International Nuclear Information System (INIS)

Wang Xingkuo; Yang Yiyong; Cheng Jia; Wang Kesheng; Sun Yuchun; Cao Minglu; Ji Linhong

2014-01-01

As one of the core components of IC manufacturing equipment, the electrostatic chuck (ESC) has been widely applied in semiconductor processing such as etching, PVD and CVD. The clamping force of the ESC is one of the most important technical indicators. A multi-physics simulation software COMSOL is used to analyze the factors influencing the clamping force. The curves between the clamping force and the main parameters such as DC voltage, electrode thickness, electrode radius, dielectric thickness and helium gap are obtained. Moreover, the effects of these factors on the clamping force are investigated by means of orthogonal experiments. The results show that the factors can be ranked in order of voltage, electrode radius, helium gap and dielectric thickness according to their importance, which may offer certain reference for the design of ESCs. (semiconductor devices)

Measurement Of Compressional-Wave Seismic Velocities In 29 Wells At The Hanford Site

International Nuclear Information System (INIS)

Peterson, S.W.

2010-01-01

Check shot seismic velocity surveys were collected in 100 B/C, 200 East, 200-PO-1 Operational Unit (OU), and the Gable Gap areas in order to provide time-depth correlation information to aid the interpretation of existing seismic reflection data acquired at the Hanford Site (Figure 1). This report details results from 5 wells surveyed in fiscal year (FY) 2008, 7 wells in FY 2009, and 17 wells in FY 2010 and provides summary compressional-wave seismic velocity information to help guide future seismic survey design as well as improve current interpretations of the seismic data (SSC 1979/1980; SGW-39675; SGW-43746). Augmenting the check shot database are four surveys acquired in 2007 in support of the Bechtel National, Inc. Waste Treatment Plant construction design (PNNL-16559, PNNL-16652), and check shot surveys in three wells to support seismic testing in the 200 West Area (Waddell et al., 1999). Additional sonic logging was conducted during the late 1970s and early 1980s as part of the Basalt Waste Isolation Program (BWIP) (SSC 1979/1980) and check shot/sonic surveys as part of the safety report for the Skagit/Hanford Nuclear project (RDH/10-AMCP-0164). Check shot surveys are used to obtain an in situ measure of compressional-wave seismic velocity for sediment and rock in the vicinity of the well point, and provide the seismic-wave travel time to geologic horizons of interest. The check shot method deploys a downhole seismic receiver (geophone) to record the arrival of seismic waves generated by a source at the ground surface. The travel time of the first arriving seismic-wave is determined and used to create a time-depth function to correlate encountered geologic intervals with the seismic data. This critical tie with the underlying geology improves the interpretation of seismic reflection profile information. Fieldwork for this investigation was conducted by in house staff during the weeks of September 22, 2008 for 5 wells in the 200 East Area (Figure 2); June 1

Modelling the clamping force distribution among chips in press-pack IGBTs using the finite element method

DEFF Research Database (Denmark)

Hasmasan, Adrian Augustin; Busca, Christian; Teodorescu, Remus

2012-01-01

In this paper, a FEM (finite element method) based mechanical model for PP (press-pack) IGBTs (insulated gate bipolar transistors) is presented, which can be used to calculate the clamping force distribution among chips under various clamping conditions. The clamping force is an important parameter...... for the chip, because it influences contact electrical resistance, contact thermal resistance and power cycling capability. Ideally, the clamping force should be equally distributed among chips, in order to maximize the reliability of the PP IGBT. The model is built around a hypothetical PP IGBT with 9 chips......, and it has numerous simplifications in order to reduce the simulation time as much as possible. The developed model is used to analyze the clamping force distribution among chips, in various study cases, where uniform and non-uniform clamping pressures are applied on the studied PP IGBT....

Microseismic Monitoring Using Sparse Surface Network of Broadband Instruments: Western Canada Shale Play Case Study

Science.gov (United States)

Yenier, E.; Baturan, D.; Karimi, S.

2016-12-01

Monitoring of seismicity related to oil and gas operations is routinely performed nowadays using a number of different surface and downhole seismic array configurations and technologies. Here, we provide a hydraulic fracture (HF) monitoring case study that compares the data set generated by a sparse local surface network of broadband seismometers to a data set generated by a single downhole geophone string. Our data was collected during a 5-day single-well HF operation, by a temporary surface network consisting of 10 stations deployed within 5 km of the production well. The downhole data was recorded by a 20 geophone string deployed in an observation well located 15 m from the production well. Surface network data processing included standard STA/LTA event triggering enhanced by template-matching subspace detection, grid search locations which was improved using the double-differencing re-location technique, as well as Richter (ML) and moment (Mw) magnitude computations for all detected events. In addition, moment tensors were computed from first motion polarities and amplitudes for the subset of highest SNR events. The resulting surface event catalog shows a very weak spatio-temporal correlation to HF operations with only 43% of recorded seismicity occurring during HF stages times. This along with source mechanisms shows that the surface-recorded seismicity delineates the activation of several pre-existing structures striking NNE-SSW and consistent with regional stress conditions as indicated by the orientation of SHmax. Comparison of the sparse-surface and single downhole string datasets allows us to perform a cost-benefit analysis of the two monitoring methods. Our findings show that although the downhole array recorded ten times as many events, the surface network provides a more coherent delineation of the underlying structure and more accurate magnitudes for larger magnitude events. We attribute this to the enhanced focal coverage provided by the surface

An isolated Hda-clamp complex is functional in the regulatory inactivation of DnaA and DNA replication.

Science.gov (United States)

Kawakami, Hironori; Su'etsugu, Masayuki; Katayama, Tsutomu

2006-10-01

In Escherichia coli, a complex consisting of Hda and the DNA-loaded clamp-subunit of the DNA polymerase III holoenzyme promotes hydrolysis of DnaA-ATP. The resultant ADP-DnaA is inactive for initiation of chromosomal DNA replication, thereby repressing excessive initiations. As the cellular content of the clamp is 10-100 times higher than that of Hda, most Hda molecules might be complexed with the clamp in vivo. Although Hda predominantly forms irregular aggregates when overexpressed, in the present study we found that co-overexpression of the clamp with Hda enhances Hda solubility dramatically and we efficiently isolated the Hda-clamp complex. A single molecule of the complex appears to consist of two Hda molecules and a single clamp. The complex is competent in DnaA-ATP hydrolysis and DNA replication in the presence of DNA and the clamp deficient subassembly of the DNA polymerase III holoenzyme (pol III*). These findings indicate that the clamp contained in the complex is loaded onto DNA through an interaction with the pol III* and that the Hda activity is preserved in these processes. The complex consisting of Hda and the DNA-unloaded clamp may play a specific role in a process proceeding to the DnaA-ATP hydrolysis in vivo.

Patch Clamp: A Powerful Technique for Studying the Mechanism of Acupuncture

Directory of Open Access Journals (Sweden)

D. Zhang

2012-01-01

Full Text Available Cellular and molecular events can be investigated using electrophysiological techniques. In particular, the patch-clamp method provides detailed information. In addition, the patch-clamp technique has become a powerful method for investigating the mechanisms underlying the effects of acupuncture. In this paper, recent researches on how acupuncture might modulate electrophysiological responses in the central nervous system (CNS and affect peripheral structures are reviewed.

Prediction of clamp-derived insulin sensitivity from the oral glucose insulin sensitivity index

DEFF Research Database (Denmark)

Tura, Andrea; Chemello, Gaetano; Szendroedi, Julia

2018-01-01

that underwent both a clamp and an OGTT or meal test, thereby allowing calculation of both the M value and OGIS. The population was divided into a training and a validation cohort (n = 359 and n = 154, respectively). After a stepwise selection approach, the best model for M value prediction was applied......AIMS/HYPOTHESIS: The euglycaemic-hyperinsulinaemic clamp is the gold-standard method for measuring insulin sensitivity, but is less suitable for large clinical trials. Thus, several indices have been developed for evaluating insulin sensitivity from the oral glucose tolerance test (OGTT). However......, most of them yield values different from those obtained by the clamp method. The aim of this study was to develop a new index to predict clamp-derived insulin sensitivity (M value) from the OGTT-derived oral glucose insulin sensitivity index (OGIS). METHODS: We analysed datasets of people...

Common voltage eliminating of SVM diode clamping three-level inverter connected to grid

DEFF Research Database (Denmark)

Guo, Yougui; Zeng, Ping; Zhu, Jieqiong

2011-01-01

A novel method of common voltage eliminating is put forward for SVM diode clamping three-level inverter connected to grid by calculation of common voltage of its various switching states. PLECS is used to model this three-level inverter connected to grid and good results are obtained. First...... analysis of common mode voltage for switching states of diode clamping 3-level inverter is given in detail. Second the common mode voltage eliminating control strategy of SVM is described for diode clamping three-level inverter. Third, PLECS is briefly introduced. Fourth, the modeling of diode clamping...... three-level inverter is presented with PLECS. Finally, a series of simulations are carried out. The simulation results tell us PLECS is a very powerful tool to real power circuits modeling. They have also verified that proposed common mode voltage eliminating control strategy of SVM is feasible...

Investigation on the Behavior of the Jointing Clamps to the Simulated Environmental - LOCA

International Nuclear Information System (INIS)

Ivan, P.; Segarceanu, D.; Geambasu, C.

2002-01-01

The paper presents the main aspect concerning the electric parameter variation of jointing clamps operating under specific environmental conditions determinate by pressure, temperature and humidity. The testing of jointing clamps capability to meet and exceed the required performances all along its operating life implies the performing of LOCA simulation conditions while the jointing clamps is bright in a relatively short time under conditions equivalent to those at the end of its service life. The paper describes ageing and measurement techniques and the analyses of electric parameter behaviour in these environmental simulated conditions. (author)

Investigation of geophysical methods for assessing seepage and internal erosion in embankment dams : a study of through-dam seismic testing at WAC Bennett Dam

Energy Technology Data Exchange (ETDEWEB)

Gaffran, P.; Jeffries, M. [BC Hydro, Burnaby, BC (Canada)

2005-07-15

Crosshole tomography is used to establish the distribution of seismic velocity between drill holes. The through-dam mode takes advantage of the triangular cross-section of earth embankments, obviating the need for drill holes. Seismic energy, generated on one face of the dam, passes underneath the crest and is detected by sensors arrayed on the opposite face. The sinkholes discovered at WAC Bennett Dam in 1996 provided an opportunity to test the procedure. Using p-wave energy, two series of measurements were conducted, notably one immediately before remediation of one sinkhole, and a second one shortly after the sinkhole was repaired. The known defect was successfully imaged by the first round of measurements. This report presented the results of an investigation of the through-dam seismic method using propagation of seismic waves through a dam from upstream to downstream, or vice-versa. The purpose of the study was to determine if this procedure could characterize the distribution of seismic velocity within a dam in an accurate and cost effective manner. The report presented the methods of velocity testing such as crosshole and downhole, and tomography; and through-dam measurements. Background to the Bennett Dam studies was also provided, with particular reference to the Bennett Dam sinkholes; sinkhole investigations; working hypothesis for sinkhole development; sinkhole number one characterization; and sinkhole remediation. An analysis of compression wave testing at Bennett Dam and shear wave testing was then offered. Other topics that were discussed included field test procedures; methodologies for data processing; p-waves versus s-waves; applicability of the research; and costs of through-dam surveys. It was concluded that under the right circumstances, through-dam seismic testing was capable of detecting changed conditions in an embankment dam. 15 refs., 2 tabs., 41 figs., 1 appendix.

Research on micromanipulator’s clamping force sensing based on static wirerope tension of a surgical robot

Directory of Open Access Journals (Sweden)

Lingtao Yu

2015-04-01

Full Text Available The micromanipulator’s force feedback is one of the key research contents of minimally invasive surgical robotic system. Because the micromanipulator is a kind of compact construction which is suitable for valve installation with small space in surgery, especially for the influence of disinfection method, there are major difficulties and limitations to integrate compact sensors in the end of micromanipulator. This article focuses on the 3-degree-of-freedom micromanipulator’s clamping force sensing, and these three joints are actuated by wirerope driving. A clamping force sensing method is proposed based on static tension of wirerope driving, and a static model between the clamping force and wirerope’s static tension is established considering the influence of real friction resistance in the mechanical system. Finally, an equivalent experimental test platform for 3-degree-of-freedom micromanipulator’s clamping force sensing is set up, and then a series of experiments of the clamping force are studied. The frictional resistances of wirerope between the guide plate and guide pulley mechanism are tested, and a calibration and correction method of the experimental clamping force is proposed. The final experiment results show that the total average accuracy of experimental clamping force is about 78.3%, and it can be the basic measurement force to realize micromanipulator’s clamping force feedback of a minimally invasive surgical robot.

Deriving Geomechanical Constraints from Microseismic Monitoring Demonstrated with Data from the Decatur CO2 Sequestration Site

Science.gov (United States)

Goertz-Allmann, B. P.; Oye, V.

2015-12-01

The occurrence of induced and triggered microseismicity is of increasing concern to the general public. The underlying human causes are numerous and include hydrocarbon production and geological storage of CO2. The concerns of induced seismicity are the potential hazards from large seismic events and the creation of fluid pathways. However, microseismicity is also a unique tool to gather information about real-time changes in the subsurface, a fact generally ignored by the public. The ability to detect, locate and characterize microseismic events, provides a snapshot of the stress conditions within and around a geological reservoir. In addition, data on rapid stress changes (i.e. microseismic events) can be used as input to hydro-mechanical models, often used to map fluid propagation. In this study we investigate the impact of microseismic event location accuracy using surface seismic stations in addition to downhole geophones. Due to signal-to-noise conditions and the small magnitudes inherent in microseismicity, downhole systems detect significantly more events with better precision of phase arrival times than surface networks. However, downhole systems are often limited in their ability to obtain large enough observational apertures required for accurate locations. We therefore jointly locate the largest microseismic events using surface and downhole data. This requires careful evaluation in the weighting of input data when inverting for the event location. For the smaller events only observed on the downhole geophones, we define event clusters using waveform cross-correlation methods. We apply this methodology to microseismic data collected in the Illinois Basin-Decatur Project. A previous study revealed over 10,000 events detected by the downhole sensors. In our analysis, we include up to 12 surface sensors, installed by the USGS. The weighting scheme for this assembly of data needs to take into account significant uncertainties in the near-surface velocity

Deciphering Equatorial Pacific Deep Sea Sediment Transport Regimes by Core-Log-Seismic Integration

Science.gov (United States)

Ortiz, E.; Tominaga, M.; Marcantonio, F.

2017-12-01

Investigating deep-sea sediment transportation and deposition regimes is a key to accurately understand implications from geological information recorded by pelagic sediments, e.g. climate signals. However, except for physical oceanographic particle trap experiments, geochemical analyses of in situsediments, and theoretical modeling of the relation between the bottom currents and sediment particle flux, it has remained a challenging task to document the movement of deep sea sediments, that takes place over time. We utilized high-resolution, multichannel reflection seismic data from the eastern equatorial Pacific region with drilling and logging results from two Integrated Ocean Drilling Program (IODP) sites, the Pacific Equatorial Age Transect (PEAT) 7 (Site U1337) and 8 (Site U1338), to characterize sediment transportation regimes on 18-24 Ma oceanic crust. Site U1337, constructed by a series of distinct abyssal hills and abyssal basins; Site U1338, located 570 km SE from Site U1337 site and constructed by a series of ridges, seamounts, and abyssal hills. These sites are of particular interest due to their proximity to the equatorial productivity zone, areas with high sedimentation rates and preservation of carbonate-bearing sediment that provide invaluable insights on equatorial Pacific ecosystems and carbon cycle. We integrate downhole geophysical logging data as well as geochemistry and physical properties measurements on recovered cores from IODP Sites U1337 and U1338 to comprehensively examine the mobility of deep-sea sediments and sediment diagenesis over times in a quasi-3D manner. We also examine 1100 km of high resolution underway seismic surveys from site survey lines in between PEAT 7 and 8 in order to investigate changes in sediment transportation between both sites. Integrating detailed seismic interpretations, high resolution core data, and 230Th flux measurements we aim to create a detailed chronological sedimentation and sediment diagenesis history

Clamp and Gas Nozzle for TIG Welding

Science.gov (United States)

Gue, G. B.; Goller, H. L.

1982-01-01

Tool that combines clamp with gas nozzle is aid to tungsten/inert-gas (TIG) welding in hard-to-reach spots. Tool holds work to be welded while directing a stream of argon gas at weld joint, providing an oxygen-free environment for tungsten-arc welding.

The Anion Paradox in Sodium Taste Reception: Resolution by Voltage-Clamp Studies

Science.gov (United States)

Ye, Qing; Heck, Gerard L.; Desimone, John A.

1991-11-01

Sodium salts are potent taste stimuli, but their effectiveness is markedly dependent on the anion, with chloride yielding the greatest response. The cellular mechanisms that mediate this phenomenon are not known. This "anion paradox" has been resolved by considering the field potential that is generated by restricted electrodiffusion of the anion through paracellular shunts between taste-bud cells. Neural responses to sodium chloride, sodium acetate, and sodium gluconate were studied while the field potential was voltage-clamped. Clamping at electronegative values eliminated the anion effect, whereas clamping at electropositive potentials exaggerated it. Thus, field potentials across the lingual epithelium modulate taste reception, indicating that the functional unit of taste reception includes the taste cell and its paracellular microenvironment.

Timing of umbilical cord-clamping and infant anaemia: the role of maternal anaemia.

Science.gov (United States)

Blouin, Brittany; Penny, Mary E; Maheu-Giroux, Mathieu; Casapía, Martín; Aguilar, Eder; Silva, Hermánn; Creed-Kanashiro, Hilary M; Joseph, Serene A; Gagnon, Anita; Rahme, Elham; Gyorkos, Theresa W

2013-05-01

Evidence from randomized controlled trials has shown that delayed cord-clamping is beneficial to infant iron status. The role of maternal anaemia in this relationship, however, has not been established. To determine the effect of maternal anaemia at delivery on the association between timing of umbilical cord-clamping and infant anaemia at 4 and 8 months of age. A cohort of pregnant women admitted to the labour room of Hospital Iquitos (Iquitos, Peru) and their newborns were recruited into the study during two time periods (18 May to 3 June and 6-20 July 2009). Between the two recruitment periods, the hospital's policy changed from early to delayed umbilical cord-clamping. Maternal haemoglobin levels were measured before delivery, and the time between delivery and cord-clamping was recorded at delivery for the entire cohort. Mother-infant pairs were followed-up at 4 (n = 207) and 8 months (n = 184) post partum. Infant haemoglobin levels were measured at follow-up visits. Data were analysed using logistic regression models. The prevalence of maternal anaemia (Hb anaemia was modified by the mother's anaemia status. Significant benefits of delayed cord-clamping in preventing anaemia were found in infants born to anaemic mothers at both 4 months (aOR = 0.59, 95% CI 0.36-0.99) and 8 months (aOR = 0.38, 95% CI 0.19-0.76) of age. The study contributes additional evidence in support of delayed cord-clamping. This intervention is likely to have most public health impact in areas with a high prevalence of anaemia during pregnancy.

Enhancing endogenous stem cells in the newbornvia delayed umbilical cord clamping

Institute of Scientific and Technical Information of China (English)

Christopher Lawton; Sandra Acosta; Nate Watson; Chiara Gonzales-Portillo; hTeo Diamandis; Naoki Tajiri; Yuji Kaneko; Paul R. Sanberg; Cesar V. Borlongan

2015-01-01

There is currently no consensus among clinicians and scientists over the appropriate or optimal timing for umbilical cord clamping. However, many clinical studies have suggested that delayed cord clamping is associated with various neonatal beneifts including increased blood volume, reduced need for blood transfusion, increased cerebral oxygenation in pre-term infants, and decreased frequency of iron deifciency anemia in term infants. Human umbilical cord blood con-tains signiifcant amounts of stem and progenitor cells and is currently used in the treatment of several life-threatening diseases. We propose that delayed cord clamping be encouraged as it en-hances blood lfow from the placenta to the neonate, which is accompanied by an increase supply of valuable stem and progenitor cells, as well as may improve blood oxygenation and increase blood volume, altogether reducing the infant’s susceptibility to both neonatal and age-related diseases.

Evaluation of selected martensitic stainless steels for use in downhole tubular expansion - Results of a laboratory study

Energy Technology Data Exchange (ETDEWEB)

Mack, Robert [Shell International E and P, b.v. Kessler Park 1, Postbus 60, 2280 AB Rijswijk (Netherlands)

2004-07-01

A laboratory program was performed to evaluate the potential of selected martensitic stainless steels for downhole cladding applications. The evaluation of the effects of tubular expansion on mechanical properties, defects, and resistance to environmentally assisted cracking demonstrated that some steels were acceptable for the intended application. The results were used to qualify and select the stainless steel for the intended sweet cladding applications. (authors)

A Fiber-Optic Borehole Seismic Vector Sensor System for Geothermal Site Characterization and Monitoring

Energy Technology Data Exchange (ETDEWEB)

Paulsson, Bjorn N.P. [Paulsson, Inc., Van Nuys, CA (United States); Thornburg, Jon A. [Paulsson, Inc., Van Nuys, CA (United States); He, Ruiqing [Paulsson, Inc., Van Nuys, CA (United States)

2015-04-21

Seismic techniques are the dominant geophysical techniques for the characterization of subsurface structures and stratigraphy. The seismic techniques also dominate the monitoring and mapping of reservoir injection and production processes. Borehole seismology, of all the seismic techniques, despite its current shortcomings, has been shown to provide the highest resolution characterization and most precise monitoring results because it generates higher signal to noise ratio and higher frequency data than surface seismic techniques. The operational environments for borehole seismic instruments are however much more demanding than for surface seismic instruments making both the instruments and the installation much more expensive. The current state-of-the-art borehole seismic instruments have not been robust enough for long term monitoring compounding the problems with expensive instruments and installations. Furthermore, they have also not been able to record the large bandwidth data available in boreholes or having the sensitivity allowing them to record small high frequency micro seismic events with high vector fidelity. To reliably achieve high resolution characterization and long term monitoring of Enhanced Geothermal Systems (EGS) sites a new generation of borehole seismic instruments must therefore be developed and deployed. To address the critical site characterization and monitoring needs for EGS programs, US Department of Energy (DOE) funded Paulsson, Inc. in 2010 to develop a fiber optic based ultra-large bandwidth clamped borehole seismic vector array capable of deploying up to one thousand 3C sensor pods suitable for deployment into ultra-high temperature and high pressure boreholes. Tests of the fiber optic seismic vector sensors developed on the DOE funding have shown that the new borehole seismic sensor technology is capable of generating outstanding high vector fidelity data with extremely large bandwidth: 0.01 – 6,000 Hz. Field tests have shown

Clampe de Ganz no tratamento de urgência em lesões do anel pélvico Ganz clamps to treat emergencies in pelvic ring lesions

Directory of Open Access Journals (Sweden)

Gilberto José Cação Pereira

2008-07-01

Full Text Available OBJETIVO: Avaliar a eficiência do clampe de Ganz na estabilização e redução dos deslocamentos da pelve, quando utilizado no tratamento de urgência, além de aquilatar eventuais dificuldades e facilidades do método. MÉTODOS: O clampe de Ganz foi utilizado no tratamento de urgência em 31 pacientes com graves lesões do anel pélvico (Tile C associadas a importante instabilidade hemodinâmica. RESULTADO: Entre os pacientes, 27 (87,1% apresentaram evolução favorável, com estabilização, redução dos deslocamentos e compressão da região posterior do anel, além de estabilização hemodinâmica, e quatro (12,9% evoluíram para óbito. CONCLUSÃO: O clampe de Ganz mostrou-se eficiente ferramenta no tratamento de urgência das lesões do anel pélvico, por ser de concepção simples, de rápida colocação, não impedir ou dificultar procedimentos no abdome e, principalmente, por permitir a estabilização da pelve, redução dos deslocamentos e compressão na região posterior do anel, local onde ocorrem os maiores sangramentos, reduzindo-os ou eliminando-os.OBJECTIVE: To evaluate the effectiveness of Ganz clamp to stabilize and reduce pelvic dislocations in emergency situations, and to assess possible difficult and easy aspects of the method. METHOD: Ganz clamp was used in the emergency treatment of 31 patients with severe lesions of the pelvic ring (Tile C associated to major hemodynamic instability. RESULTS: Among the patients, 27 (87.1% presented a favorable evolution, with stabilization, reduction of dislocations, and compression of the posterior portion of the ring, and also hemodynamic stabilization, and 4 (12.9% died. CONCLUSION: The Ganz clamp was found to be an effective tool in the emergency treatment of pelvic ring lesions because it has an uncomplicated conception, allowing for a fast placement, because it does not prevent nor make it difficult for abdominal procedures, and most of all because it allows for the

Evaluation of Introduction of a Delayed Cord Clamping Protocol for Premature Neonates in a High-Volume Maternity Center.

Science.gov (United States)

Liu, Lilly Y; Feinglass, Joe M; Khan, Janine Y; Gerber, Susan E; Grobman, William A; Yee, Lynn M

2017-05-01

To evaluate adherence to a delayed cord clamping protocol for preterm births in the first 2 years after its introduction, perform a quality improvement assessment, and determine neonatal outcomes associated with protocol implementation and adherence. This is a retrospective cohort study of women delivering singleton neonates at 23-32 weeks of gestation in the 2 years before (preprotocol) and 2 years after (postprotocol) introduction of a 30-second delayed cord clamping protocol at a large-volume academic center. This policy was communicated to obstetric and pediatric health care providers and nurses and reinforced with intermittent educational reviews. Barriers to receiving delayed cord clamping were assessed using χ tests and multivariable logistic regression. Neonatal outcomes then were compared between all neonates in the preprotocol period and all neonates in the postprotocol period and between all neonates in the preprotocol period and neonates receiving delayed cord clamping in the postprotocol period using multivariable linear and logistic regression analyses. Of the 427 eligible neonates, 187 were born postprotocol. Of these, 53.5% (n=100) neonates received delayed cord clamping according to the protocol. The rate of delayed cord clamping preprotocol was 0%. Protocol uptake and frequency of delayed cord clamping increased over the 2 years after its introduction. In the postprotocol period, cesarean delivery was the only factor independently associated with failing to receive delayed cord clamping (adjusted odds ratio [OR] 0.49, 95% confidence interval [CI] 0.25-0.96). In comparison with the preprotocol period, those who received delayed cord clamping in the postprotocol period had significantly higher birth hematocrit (β=2.46, P=.007) and fewer blood transfusions in the first week of life (adjusted OR 0.49, 95% CI 0.25-0.96). After introduction of an institutional delayed cord clamping protocol followed by continued health care provider education and

Higher order modes excitation of electrostatically actuated clamped–clamped microbeams: experimental and analytical investigation

KAUST Repository

Jaber, Nizar; Ramini, Abdallah; Carreno, Armando Arpys Arevalo; Younis, Mohammad I.

2016-01-01

© 2016 IOP Publishing Ltd. In this study, we demonstrate analytically and experimentally the excitations of the higher order modes of vibrations in electrostatically actuated clamped-clamped microbeam resonators. The concept is based on using

Investigation of sinkhole areas in Germany using 2D shear wave reflection seismics and zero-offset VSP

Science.gov (United States)

Tschache, Saskia; Wadas, Sonja; Polom, Ulrich; Krawczyk, Charlotte M.

2017-04-01

Sinkholes pose a serious geohazard for humans and infrastructure in populated areas. The Junior Research Group Subrosion within the Leibniz Institute for Applied Geophysics and the joint project SIMULTAN work on the multi-scale investigation of subrosion processes in the subsurface, which cause natural sinkholes. In two case studies in sinkhole areas of Thuringia in Germany, we applied 2D shear wave reflection seismics using SH-waves with the aim to detect suitable parameters for the characterisation of critical zones. This method has the potential to image near-surface collapse and faulting structures in improved resolution compared to P-wave surveys resulting from the shorter wavelength of shear waves. Additionally, the shear wave velocity field derived by NMO velocity analysis is a basis to calculate further physical parameters, as e.g. the dynamic shear modulus. In both investigation areas, vertical seismic profiles (VSP) were acquired by generating P- and SH-waves (6 component VSP) directly next to a borehole equipped with a 3C downhole sensor. They provide shear and compressional wave velocity profiles, which are used to improve the 2D shear wave velocity field from surface seismics, to perform a depth calibration of the seismic image and to calculate the Vp/Vs ratio. The signals in the VSP data are analysed with respect to changes in polarisation and attenuation with depth and/or azimuth. The VSP data reveal low shear wave velocities of 200-300 m/s in rock layers known to be heavily affected by subrosion and confirm the low velocities calculated from the surface seismic data. A discrepancy of the shear wave velocities is observed in other intervals probably due to unsymmetrical travel paths in the surface seismics. In some VSP data dominant conversion of the direct SH-wave to P-wave is observed that is assumed to be caused by an increased presence of cavities. A potential fault distorting the vertical travel paths was detected by abnormal P-wave first

21 CFR 882.5175 - Carotid artery clamp.

Science.gov (United States)

2010-04-01

... (the principal artery in the neck that supplies blood to the brain) and has a removable adjusting mechanism that protrudes through the skin of the patient's neck. The clamp is used to occlude the patient's... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...

Adaptive Sensor Tuning for Seismic Event Detection in Environment with Electromagnetic Noise

Science.gov (United States)

Ziegler, Abra E.

The goal of this research is to detect possible microseismic events at a carbon sequestration site. Data recorded on a continuous downhole microseismic array in the Farnsworth Field, an oil field in Northern Texas that hosts an ongoing carbon capture, utilization, and storage project, were evaluated using machine learning and reinforcement learning techniques to determine their effectiveness at seismic event detection on a dataset with electromagnetic noise. The data were recorded from a passive vertical monitoring array consisting of 16 levels of 3-component 15 Hz geophones installed in the field and continuously recording since January 2014. Electromagnetic and other noise recorded on the array has significantly impacted the utility of the data and it was necessary to characterize and filter the noise in order to attempt event detection. Traditional detection methods using short-term average/long-term average (STA/LTA) algorithms were evaluated and determined to be ineffective because of changing noise levels. To improve the performance of event detection and automatically and dynamically detect seismic events using effective data processing parameters, an adaptive sensor tuning (AST) algorithm developed by Sandia National Laboratories was utilized. AST exploits neuro-dynamic programming (reinforcement learning) trained with historic event data to automatically self-tune and determine optimal detection parameter settings. The key metric that guides the AST algorithm is consistency of each sensor with its nearest neighbors: parameters are automatically adjusted on a per station basis to be more or less sensitive to produce consistent agreement of detections in its neighborhood. The effects that changes in neighborhood configuration have on signal detection were explored, as it was determined that neighborhood-based detections significantly reduce the number of both missed and false detections in ground-truthed data. The performance of the AST algorithm was

Analysis and testing of the DIII-D ohmic heating coil lead repair clamp

International Nuclear Information System (INIS)

Reis, E.E.; Anderson, P.M.; Chin, E.; Robinson, J.I.

1997-11-01

DIII-D has been operating for the last year with limited volt-second capabilities due to structural failure of a conductor lead to one of the ohmic heating (OH) solenoids. The conductor failure was due to poor epoxy impregnation of the overwrap of the lead pack, resulting in copper fatigue and a water leak. A number of structural analyses were performed to assist in determining the failure scenario and to evaluate various repair options. A fatigue stress analysis of the leads with a failed epoxy overwrap indicated crack initiation after 1,000 cycles at the maximum operating conditions. The failure occurred in a very inaccessible area which restricted design repair options to concepts which could be implemented remotely. Several design options were considered for repairing the lead so that it can sustain the loads for 7.5 Vs conditions at full toroidal field. A clamp, along with preloaded banding straps and shim bags, provides a system that guarantees that the stress at the crack location is always compressive and prevents further crack growth in the conductor. Due to the limited space available for the repair, it was necessary to design the clamp system to operate at the material yield stress. The primary components of the clamp system were verified by load tests prior to installation. The main body of the clamp contains a load cell and potentiometer for monitoring the load-deflection characteristics of the clamp and conductors during plasma operation. Strain gages provides redundant instrumentation. If required, the preload on the conductors can be increased remotely by a special wrench attached to the clamp assembly

Ventilation before Umbilical Cord Clamping improves the physiological transition at birth.

Directory of Open Access Journals (Sweden)

Sasmira eBhatt

2014-10-01

Full Text Available The transition from a fetus to a neonate at birth represents a critical phase in our life. Most infants make this transition without complications, but preterm infants usually require some form of assistance due to immature cardiopulmonary systems that predispose them to lifelong sequelae. As the incidence of preterm birth is increasing, there is now an urgent need for the development of management strategies that facilitate this transition, which will likely include improved strategies for the management of the maternal third stage of labour. For instance, recent studies on the physiological transition at birth have led to the discovery that establishing ventilation in the infant before the umbilical cord is clamped greatly stabilizes the cardiovascular transition at birth. While most benefits of delayed clamping have previously been attributed to an increase in placenta to infant blood transfusion, clearly there are other significant benefits for the infant, which are not well understood. Nevertheless, if ventilation can be established before cord clamping in a preterm infant, the large adverse changes in cardiac function that normally accompanies umbilical cord clamping can be avoided. As preterm infants have an immature cerebral vascular bed, large swings in cardiovascular function places them at high risk of cerebral vascular rupture and the associated increased risk of mortality and morbidity. In view of the impact that cord clamping has on the cardiovascular transition at birth, it is also time to re-examine some of the strategies used in the management of the third stage of labour. These include the appropriate timing of uterotonic administration in relation to delivery of the infant and placenta. As there is a lack of evidence on the effects these individual practices have on the infant, there is a necessity to improve our understanding of their impact in order to develop strategies that facilitate the transition to newborn life.

CLAMP - a toolkit for efficiently building customized clinical natural language processing pipelines.

Science.gov (United States)

Soysal, Ergin; Wang, Jingqi; Jiang, Min; Wu, Yonghui; Pakhomov, Serguei; Liu, Hongfang; Xu, Hua

2017-11-24

Existing general clinical natural language processing (NLP) systems such as MetaMap and Clinical Text Analysis and Knowledge Extraction System have been successfully applied to information extraction from clinical text. However, end users often have to customize existing systems for their individual tasks, which can require substantial NLP skills. Here we present CLAMP (Clinical Language Annotation, Modeling, and Processing), a newly developed clinical NLP toolkit that provides not only state-of-the-art NLP components, but also a user-friendly graphic user interface that can help users quickly build customized NLP pipelines for their individual applications. Our evaluation shows that the CLAMP default pipeline achieved good performance on named entity recognition and concept encoding. We also demonstrate the efficiency of the CLAMP graphic user interface in building customized, high-performance NLP pipelines with 2 use cases, extracting smoking status and lab test values. CLAMP is publicly available for research use, and we believe it is a unique asset for the clinical NLP community. © The Author 2017. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Vertical seismic profile data from well Mallik 2L-38 for gas hydrate studies

Energy Technology Data Exchange (ETDEWEB)

Mi, Y [Calgary Univ., AB (Canada); Walia, R [Victoria Univ., BC (Canada); Hyndman, R D; Sakai, A

1999-01-01

A gas hydrate research well was drilled in the Canadian Arctic to determine gas hydrates in a permafrost setting in a collaborative research project between the Japan National Oil Corp., and the Geological Survey of Canada with the participation of other agencies. The multidisciplinary study included an electromagnetic survey, permafrost and gas hydrate coring, and comprehensive downhole geophysical logging and measurement. Laboratory studies on recovered cores and cuttings included sedimentology, physical properties, geochemistry, and reservoir characteristics of the Mallik gas accumulation. As part of the field program, a vertical seismic profiling survey was conducted at zero and offset source positions with 3 component receiver tools and horizontal and vertical vibration sources. A special effort was made to record shear wave data, and results from this work were combined with down hole logs and regional surface seismic data. The data will be used also to determine the effect of gas hydrates on formation velocities and to measure gas hydrate concentrations as a function of depth in the formation penetrated by the well. Certain conclusions followed from the initial VSP analysis. 1) Zero offset vertical vibration Z component and horizontal X component data give reliable velocity estimation within the gas hydrate formation zone, and P wave velocities from offset data indicate excellent consistency with that from zero offset data and with the sonic log. 2) The VSP data permitted reliable identification of gas hydrate bearing zones. 4 refs.

Effect of complete hilar versus only renal artery clamping on renal histomorphology following ischemia/reperfusion injury in an experimental model.

Science.gov (United States)

Umul, M; Cal, A C; Turna, B; Oktem, G; Aydın, H H

2016-01-01

To evaluate the effect of temporary complete hilar versus only renal artery clamping with different duration of warm ischemia on renal functions, and possibly identify a "safe" clamping type and duration of renal ischemia. Fifty male rabbits have been incorporated to study. Rabbits were subjected to ischemia/reperfusion injury by temporary vascular clamping. Reagents were randomized to 3 experimental groups (only renal artery clamping, complete hilar clamping, sham surgery) and sub-groups were determined according to different clamping times (30 and 60 minutes). Median laparotomy and left renal hilus dissection were performed to sham group. Only artery or complete hilar clamping was performed for 30 or 60 minutes by microvascular bulldog clamps to other reagents. Rabbits were sacrificed 10 days after primary surgery and left nephrectomy performed. Nephrectomy materials were evaluated for the level of nitric-oxide synthase (NOS) immunoreactivity, malondialdehyde (MDA) level and superoxide dismutase (SOD) activity and an electron microscopic examination was performed. NOS immunoreactivity was correlated with the temporary clamping time. We also observed that complete hilar vascular clamping entails an increase on NOS immunoreactivity. MDA levels were similar for all experimental surgery groups (p = 0.42). The SOD activity was decreased among all subgroups compared with sham surgery. But the significant decrease occurred in 30 minutes only artery and 30 minutes complete hilar clamping groups in proportion to sham surgery (p = 0.026 and p = 0.019, respectively). This current study suggested that only renal artery clamping under 30 minutes is more appropriate during renal surgical procedures requiring temporary vascular clamping.

Three Level Diode Clamped Inverter Fed Induction Motor with Dtc-Svm

OpenAIRE

V. Ranjith Kumar

2013-01-01

This project presents a three-level diode-clamped inverter feeding an asynchronous motor drive with direct torque control (DTC). The control method is based on DTC operating principles. The stator voltage vector reference is computed from the stator flux and torque errors imposed by the flux and torque controllers. This voltage reference is then generated using a diode-clamped inverter, where each phase of the inverter can be implemented using a dc source, which would be available from fuel c...

Measurement of Streaming Potential in Downhole Application: An Insight for Enhanced Oil Recovery Monitoring

Directory of Open Access Journals (Sweden)

Tengku Mohd Tengku Amran

2017-01-01

Full Text Available Downhole monitoring using streaming potential measurement has been developing in order to respond to actual reservoir condition. Most studies have emphasized on monitoring water flooding at various reservoir condition and improving the approaches of measurement. Enhanced Oil Recovery (EOR could significantly improve oil recovery and the efficiency of the process should be well-monitored. Alkaline-surfactant-polymer (ASP flooding is the most promising chemical EOR method due to its synergy of alkaline, surfactant and polymer, which could enhance the extraction of residual oil. However, limited studies have been focused on the application of streaming potential in EOR processes, particularly ASP. Thus, this paper aims to review the streaming potential measurement in downhole monitoring with an insight for EOR application and propose the potential measurement in monitoring ASP flooding. It is important for a preliminary study to investigate the synergy in ASP and the effects on oil recovery. The behaviour of streaming potential should be investigated when the environment of porous media changes with respect to ASP flooding. Numerical model can be generated from the experimental data to forecast the measured streaming potential signal during production associated with ASP flooding. Based on the streaming potential behaviour on foam assisted water alternate gas (FAWAG and water alternate gas (WAG processes, it is expected that the streaming potential could change significantly when ASP flooding alters the environment and surface properties of porous media. The findings could provide new prospect and knowledge in the relationship between streaming potential and ASP mechanisms, which could be a potential approach in monitoring the efficiency of the process.

Suppression of Spiral Waves by Voltage Clamp Techniques in a Conductance-Based Cardiac Tissue Model

International Nuclear Information System (INIS)

Lian-Chun, Yu; Guo-Yong, Zhang; Yong, Chen; Jun, Ma

2008-01-01

A new control method is proposed to control the spatio-temporal dynamics in excitable media, which is described by the Morris–Lecar cells model. It is confirmed that successful suppression of spiral waves can be obtained by spatially clamping the membrane voltage of the excitable cells. The low voltage clamping induces breakup of spiral waves and the fragments are soon absorbed by low voltage obstacles, whereas the high voltage clamping generates travel waves that annihilate spiral waves through collision with them. However, each method has its shortcomings. Furthermore, a two-step method that combines both low and high voltage clamp techniques is then presented as a possible way of out this predicament. (cross-disciplinary physics and related areas of science and technology)

Application of surface–downhole combined microseismic monitoring technology in the Fuling shale gas field and its enlightenment

Directory of Open Access Journals (Sweden)

Yaowen Liu

2017-01-01

Full Text Available The Fuling shale gas field in the Sichuan Basin, as a national shale gas demonstration area, is the largest commercially developed shale gas field in the world except those in North America. The fracturing technology in the mode of “well factory” has been applied widely in the gas field, but it is necessary to perform further investigation on the way to evaluate effectively the fracturing effect of multi-well platform “well factory” and the distribution laws of its induced fracture networks. In this paper, the fractures induced by the “well factory” at the JY 48 platform were real-time monitored by a surface–downhole combined microseismic monitoring technology. The geometric size and extension direction of artificial fractures induced in the model of “well factory” fracturing in the Jiaoshiba block of Fuling Shale Gas Field were preliminarily understood. Moreover, the fracturing parameters under the mode of “well factory” were recognized by using the comprehensive interpretation results of surface–downhole combined microseismic monitoring technology, together with the SRV fracturing prediction chart. Eventually, the distribution laws of artificial fractures during the “well-factory-zipper” fracturing in the Fuling Shale Gas Field were clarified definitely. This paper provides guidance for the optimization of fracturing parameters at the later stage.

Substrate clamping effects on irreversible domain wall dynamics in lead zirconate titanate thin films.

Science.gov (United States)

Griggio, F; Jesse, S; Kumar, A; Ovchinnikov, O; Kim, H; Jackson, T N; Damjanovic, D; Kalinin, S V; Trolier-McKinstry, S

2012-04-13

The role of long-range strain interactions on domain wall dynamics is explored through macroscopic and local measurements of nonlinear behavior in mechanically clamped and released polycrystalline lead zirconate-titanate (PZT) films. Released films show a dramatic change in the global dielectric nonlinearity and its frequency dependence as a function of mechanical clamping. Furthermore, we observe a transition from strong clustering of the nonlinear response for the clamped case to almost uniform nonlinearity for the released film. This behavior is ascribed to increased mobility of domain walls. These results suggest the dominant role of collective strain interactions mediated by the local and global mechanical boundary conditions on the domain wall dynamics. The work presented in this Letter demonstrates that measurements on clamped films may considerably underestimate the piezoelectric coefficients and coupling constants of released structures used in microelectromechanical systems, energy harvesting systems, and microrobots.

Behavior of a hollow core photonic crystal fiber under high radial pressure for downhole application

Energy Technology Data Exchange (ETDEWEB)

Sadeghi, J., E-mail: j-sadeghi@sbu.ac.ir; Chenari, Z.; Ziaee, F. [Laser and Plasma Research Institute, Shahid Beheshti University, 1983963113 Tehran (Iran, Islamic Republic of); Latifi, H., E-mail: latifi@sbu.ac.ir [Laser and Plasma Research Institute, Shahid Beheshti University, 1983963113 Tehran (Iran, Islamic Republic of); Department of Physics, Shahid Beheshti University, Evin, 1983963113 Tehran (Iran, Islamic Republic of); Santos, J. L., E-mail: josantos@fc.up.pt [INESC Porto—Instituto de Engenharia de Sistemas e Computadores do Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal); Departamento de Física, da Faculdade de Ciências, da Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal)

2014-02-17

Pressure fiber sensors play an important role in downhole high pressure measurements to withstand long term operation. The purpose of this paper is to present an application of hollow core photonic crystal fiber (HC-PCF) as a high pressure sensor head for downhole application based on dispersion variation. We used a high pressure stainless steel unit to exert pressure on the sensor. The experimental results show that different wavelengths based on sagnac loop interferometer have additive sensitivities from 5 × 10{sup −5} nm/psi at 1480 nm to 1.3 × 10{sup −3} nm/psi at 1680 nm. We developed a simulation to understand the reason for difference in sensitivity of wavelengths and also the relationship between deformation of HC-PCF and dispersion variation under pressure. For this purpose, by using the finite element method, we investigated the effect of structural variation of HC-PCF on spectral transformation of two linear polarizations under 1000 psi pressure. The simulation and experimental results show exponential decay behavior of dispersion variation from −3.4 × 10{sup −6} 1/psi to −1.3 × 10{sup −6} 1/psi and from −5 × 10{sup −6} 1/psi to −1.8 × 10{sup −6} 1/psi, respectively, which were in a good accordance with each other.

Γ-source Neutral Point Clamped Inverter

DEFF Research Database (Denmark)

Mo, Wei; Loh, Poh Chiang; Blaabjerg, Frede

Transformer based Z-source inverters are recently proposed to achieve promising buck-boost capability. They have improved higher buck-boost capability, smaller size and less components count over Z-source inverters. On the other hand, neutral point clamped inverters have less switching stress...... and better output performance comparing with traditional two-level inverters. Integrating these two types of configurations can help neutral point inverters achieve enhanced votlage buck-boost capability....

Constant-frequency, clamped-mode resonant converters

Science.gov (United States)

Tsai, Fu-Sheng; Materu, Peter; Lee, Fred C.

1987-01-01

Two novel clamped-mode resonant converters are proposed which operate at a constant frequency while retaining many desired features of conventional series- and parallel-resonant converters. State-plane analysis techniques are used to identify all possible operating modes and define their mode boundaries. Control-to-output characteristics are derived that specify the regions for natural and forced commutation. The predicted operating modes are verified using a prototype circuit.

Evaluation of the lithology contents and types of clay minerals using downhole spectral analyzer of natural gamma radiation

International Nuclear Information System (INIS)

Zivanov, M.; Savicic, M.; Grbovic, G.

1992-01-01

The microprocessor downhole spectrum analyzer of natural gamma radiation is an important part of the new generation of geophysical well logging systems. This instrument produces complete energy spectra of the penetrated formations. here physical principles of logging are shown. based on the logging results from one of the wells complex lithology was identified, together with shale contents in the formation and types of clay and minerals. (author)

275 C Downhole Microcomputer System

Energy Technology Data Exchange (ETDEWEB)

Chris Hutchens; Hooi Miin Soo

2008-08-31

An HC11 controller IC and along with serial SRAM and ROM support ICs chip set were developed to support a data acquisition and control for extreme temperature/harsh environment conditions greater than 275 C. The 68HC11 microprocessor is widely used in well logging tools for control, data acquisition, and signal processing applications and was the logical choice for a downhole controller. This extreme temperature version of the 68HC11 enables new high temperature designs and additionally allows 68HC11-based well logging tools and MWD tools to be upgraded for high temperature operation in deep gas reservoirs, The microcomputer chip consists of the microprocessor ALU, a small boot ROM, 4 kbyte data RAM, counter/timer unit, serial peripheral interface (SPI), asynchronous serial interface (SCI), and the A, B, C, and D parallel ports. The chip is code compatible with the single chip mode commercial 68HC11 except for the absence of the analog to digital converter system. To avoid mask programmed internal ROM, a boot program is used to load the microcomputer program from an external mask SPI ROM. A SPI RAM IC completes the chip set and allows data RAM to be added in 4 kbyte increments. The HC11 controller IC chip set is implemented in the Peregrine Semiconductor 0.5 micron Silicon-on-Sapphire (SOS) process using a custom high temperature cell library developed at Oklahoma State University. Yield data is presented for all, the HC11, SPI-RAM and ROM. The lessons learned in this project were extended to the successful development of two high temperature versions of the LEON3 and a companion 8 Kbyte SRAM, a 200 C version for the Navy and a 275 C version for the gas industry.

2750 C Downhole Microcomputer System

International Nuclear Information System (INIS)

Hutchens, Chris; Soo, Hooi Miin

2008-01-01

An HC11 controller IC and along with serial SRAM and ROM support ICs chip set were developed to support a data acquisition and control for extreme temperature/harsh environment conditions greater than 275 C. The 68HC11 microprocessor is widely used in well logging tools for control, data acquisition, and signal processing applications and was the logical choice for a downhole controller. This extreme temperature version of the 68HC11 enables new high temperature designs and additionally allows 68HC11-based well logging tools and MWD tools to be upgraded for high temperature operation in deep gas reservoirs, The microcomputer chip consists of the microprocessor ALU, a small boot ROM, 4 kbyte data RAM, counter/timer unit, serial peripheral interface (SPI), asynchronous serial interface (SCI), and the A, B, C, and D parallel ports. The chip is code compatible with the single chip mode commercial 68HC11 except for the absence of the analog to digital converter system. To avoid mask programmed internal ROM, a boot program is used to load the microcomputer program from an external mask SPI ROM. A SPI RAM IC completes the chip set and allows data RAM to be added in 4 kbyte increments. The HC11 controller IC chip set is implemented in the Peregrine Semiconductor 0.5 micron Silicon-on-Sapphire (SOS) process using a custom high temperature cell library developed at Oklahoma State University. Yield data is presented for all, the HC11, SPI-RAM and ROM. The lessons learned in this project were extended to the successful development of two high temperature versions of the LEON3 and a companion 8 Kbyte SRAM, a 200 C version for the Navy and a 275 C version for the gas industry

Theoretical background and the flow fields in downhole liquid-liquid hydrocyclone (LLHC

Directory of Open Access Journals (Sweden)

Osei Harrison

2014-07-01

Full Text Available Hydrocyclone system for downhole oil-water separation provides an effective technique of enhancing the economic viability of higher water-cut wells while at the same time reducing the risk of environmental pollution. This paper describes the hydrodynamics of the liquid-liquid hydrocyclones and the flow fields within it are paramount for achieving successful separation process. Some of the important hydrodynamic flow phenomenon within the liquid-liquid hydrocyclone and how they influence the separation efficiency of water/oil was analyzed through analytical solution. The properties of the liquids were based on Bayan offshore field measured properties. The results indicated that there are two swirling zones separated by stagnant flow field. The inner is the light liquid zone, while the outer is the heavy liquid zone.

The optimal protocol to reduce blood loss and blood transfusion after unilateral total knee replacement: Low-dose IA-TXA plus 30-min drain clamping versus drainage clamping for the first 3 h without IA-TXA.

Science.gov (United States)

Park, Joo Hyun; Choi, Sung Wook; Shin, Eun Ho; Park, Myung Hoon; Kim, Myung Ku

2017-01-01

Although intraarticular tranexamic acid (IA-TXA) administration or drainage clamping are popular methods used to reduce blood loss after total knee replacement (TKR), the protocol remains controversial. We aimed (1) to establish new protocols through investigating whether two methods, that is, low-dose (500 mg) IA-TXA plus 30-min drain clamping and drainage clamping for the first 3 h without IA-TXA, can reduce blood loss and blood transfusion after unilateral TKR and (2) to make recommendations related to clinical application. This study, conducted from September 2014 to June 2016 related to enrolled 95 patients with primary osteoarthritis who were to have a unilateral cemented TKR, was nonrandomized and retrospective. In group A, the drain was released following tourniquet deflation. In group B, 500-mg TXA was injected into the knee joint via a drain tube after fascia closure and the drain was clamped for the first 30 min to prevent leakage. In group C, the drain was clamped for the first 3-h postoperation. Demographic characteristics and clinical data were collected, including the levels of hematocrit (Hct), the total blood loss (TBL), drained blood volume (BV), the amount of blood transfused, and any complications that developed. We found a significantly lower postoperative TBL, drained BV, decreasing Hct level, and less transfused BV in the IA-TXA injection group (group B) and the 3-h drainage clamping group (group C) compared to the conventional negative drainage group (group A; p optimal than drainage clamping in patients with high bleeding tendency or lateral retinacular release during TKR, who would be concerned about postoperative wound complication.

[The Impact of Late Umbilical Cord Clamping on Neonatal Jaundice and Postpartum Hemorrhage: A Randomized Controlled Trail].

Science.gov (United States)

Chien, Pei-Chun; Yang, Cherng-Chia; Gau, Meei-Ling; Liu, Chieh-Yu; Lee, Tzu-Ying

2015-08-01

The current evidence supports the clinical benefits of late umbilical cord clamping. These benefits include increased blood volume and total body iron. Furthermore, delayed cord clamping facilitates the transplantation of stem cells, which helps the development of infant bodily systems. However, due to concerns related to postpartum hemorrhaging and neonate jaundice, most maternity units still clamp the cord immediately after a child is born. This study investigates the impact of delaying cord clamping on neonatal jaundice and postpartum hemorrhage. A randomized, controlled trial was conducted at a regional teaching hospital in northern Taiwan. One hundred and five healthy nulliparous women at 36 weeks of pregnancy were included and allocated randomly to the experiment group (n=44) and the control group (n=61). Participants in the experiment group received delayed cord clamping (DCC) at 3 minutes after delivery. Participants in the control group received early cord clamping (ECC) at around 1 minute after delivery. Clinical measures of the outcomes were measured by the infant transcutaneous bilirubin levels (TcB) and postpartum hemorrhage at birth. A structured questionnaire and biophysical measures were used to collect data on participant demographics, obstetrical information, maternal blood loss at birth, neonate weight and TcB level at hospitalization, and whether or not the infant received phototherapy at 4-7 days postpartum. Overall, there was no significant difference between the two groups in terms of neonatal jaundice, maternal hemorrhage at birth, and phototherapy rates at time of hospitalization and at 4-7 days postpartum. The findings of the present study support that late umbilical cord clamping does not increase the risk of maternal postpartum hemorrhaging or neonate jaundice. Thus, we suggest that clinicians inform clients during prenatal classes of the benefits of delayed cord clamping and also use current, evidence-based knowledge to dispel client

Detection of gas hydrate with downhole logs and assessment of gas hydrate concentrations (saturations) and gas volumes on the Blake Ridge with electrical resistivity log data

Science.gov (United States)

Collett, T.S.; Ladd, J.

2000-01-01

Let 164 of the Ocean Drilling Program was designed to investigate the occurrence of gas hydrate in the sedimentary section beneath the Blake Ridge on the southeastern continental margin of North America. Site 994, and 997 were drilled on the Blake Ridge to refine our understanding of the in situ characteristics of natural gas hydrate. Because gas hydrate is unstable at surface pressure and temperature conditions, a major emphasis was placed on the downhole logging program to determine the in situ physical properties of the gas hydrate-bearing sediments. Downhole logging tool strings deployed on Leg 164 included the Schlumberger quad-combination tool (NGT, LSS/SDT, DIT, CNT-G, HLDT), the Formation MicroScanner (FMS), and the Geochemical Combination Tool (GST). Electrical resistivity (DIT) and acoustic transit-time (LSS/SDT) downhole logs from Sites 994, 995, and 997 indicate the presence of gas hydrate in the depth interval between 185 and 450 mbsf on the Blake Ridge. Electrical resistivity log calculations suggest that the gas hydrate-bearing sedimentary section on the Blake Ridge may contain between 2 and 11 percent bulk volume (vol%) gas hydrate. We have determined that the log-inferred gas hydrates and underlying free-gas accumulations on the Blake Ridge may contain as much as 57 trillion m3 of gas.

Robotic Automation of In Vivo Two-Photon Targeted Whole-Cell Patch-Clamp Electrophysiology.

Science.gov (United States)

Annecchino, Luca A; Morris, Alexander R; Copeland, Caroline S; Agabi, Oshiorenoya E; Chadderton, Paul; Schultz, Simon R

2017-08-30

Whole-cell patch-clamp electrophysiological recording is a powerful technique for studying cellular function. While in vivo patch-clamp recording has recently benefited from automation, it is normally performed "blind," meaning that throughput for sampling some genetically or morphologically defined cell types is unacceptably low. One solution to this problem is to use two-photon microscopy to target fluorescently labeled neurons. Combining this with robotic automation is difficult, however, as micropipette penetration induces tissue deformation, moving target cells from their initial location. Here we describe a platform for automated two-photon targeted patch-clamp recording, which solves this problem by making use of a closed loop visual servo algorithm. Our system keeps the target cell in focus while iteratively adjusting the pipette approach trajectory to compensate for tissue motion. We demonstrate platform validation with patch-clamp recordings from a variety of cells in the mouse neocortex and cerebellum. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

INTEGRATED DRILLING SYSTEM USING MUD ACTUATED DOWN HOLE HAMMER AS PRIMARY ENGINE

Energy Technology Data Exchange (ETDEWEB)

John V. Fernandez; David S. Pixton

2005-12-01

A history and project summary of the development of an integrated drilling system using a mud-actuated down-hole hammer as its primary engine are given. The summary includes laboratory test results, including atmospheric tests of component parts and simulated borehole tests of the hammer system. Several remaining technical hurdles are enumerated. A brief explanation of commercialization potential is included. The primary conclusion for this work is that a mud actuated hammer can yield substantial improvements to drilling rate in overbalanced, hard rock formations. A secondary conclusion is that the down-hole mud actuated hammer can serve to provide other useful down-hole functions including generation of high pressure mud jets, generation of seismic and sonic signals, and generation of diagnostic information based on hammer velocity profiles.

Design and experimental research of a novel inchworm type piezo-driven rotary actuator with the changeable clamping radius.

Science.gov (United States)

Zhao, Hongwei; Fu, Lu; Ren, Luquan; Huang, Hu; Fan, Zunqiang; Li, Jianping; Qu, Han

2013-01-01

In this paper, a novel piezo-driven rotary actuator with the changeable clamping radius is developed based on the inchworm principle. This actuator mainly utilizes three piezoelectric actuators, a flexible gripper, a clamping block, and a rotor to achieve large stroke rotation with high resolution. The design process of the flexible gripper consisting of the driving unit and the clamping unit is described. Lever-type mechanisms were used to amplify the micro clamping displacements. The amplifying factor and parasitic displacement of the lever-type mechanism in the clamping unit was analyzed theoretically and experimentally. In order to investigate the rotation characteristics of the actuator, a series of experiments was carried out. Experimental results indicate that the actuator can rotate at a speed of 77,488 μrad/s with a driving frequency of 167 Hz. The rotation resolution and maximum load torque of the actuator are 0.25 μrad and 37 N mm, respectively. The gripper is movable along the z direction based on an elevating platform, and the clamping radius can change from 10.6 mm to 25 mm. Experimental results confirm that the actuator can achieve different rotation speeds by changing the clamping radius.

Experimental determination of optimal clamping torque for AB-PEM Fuel cell

Directory of Open Access Journals (Sweden)

Noor Ul Hassan

2016-04-01

Full Text Available Polymer electrolyte Membrane (PEM fuel cell is an electrochemical device producing electricity by the reaction of hydrogen and oxygen without combustion. PEM fuel cell stack is provided with an appropriate clamping torque to prevent leakage of reactant gases and to minimize the contact resistance between gas diffusion media (GDL and bipolar plates. GDL porous structure and gas permeability is directly affected by the compaction pressure which, consequently, drastically change the fuel cell performance. Various efforts were made to determine the optimal compaction pressure and pressure distributions through simulations and experimentation. Lower compaction pressure results in increase of contact resistance and also chances of leakage. On the other hand, higher compaction pressure decreases the contact resistance but also narrows down the diffusion path for mass transfer from gas channels to the catalyst layers, consequently, lowering cell performance. The optimal cell performance is related to the gasket thickness and compression pressure on GDL. Every stack has a unique assembly pressure due to differences in fuel cell components material and stack design. Therefore, there is still need to determine the optimal torque value for getting the optimal cell performance. This study has been carried out in continuation of deve­lopment of Air breathing PEM fuel cell for small Unmanned Aerial Vehicle (UAV application. Compaction pressure at minimum contact resistance was determined and clamping torque value was calcu­la­ted accordingly. Single cell performance tests were performed at five different clamping torque values i.e 0.5, 1.0, 1.5, 2.0 and 2.5 N m, for achieving optimal cell per­formance. Clamping pressure distribution tests were also performed at these torque values to verify uniform pressure distribution at optimal torque value. Experimental and theoretical results were compared for making inferences about optimal cell perfor­man­ce. A

Combined acute hyperglycemic and hyperinsulinemic clamp induced profibrotic and proinflammatory responses in the kidney.

Science.gov (United States)

Mariappan, Meenalakshmi M; DeSilva, Kristin; Sorice, Gian Pio; Muscogiuri, Giovanna; Jimenez, Fabio; Ahuja, Seema; Barnes, Jefferey L; Choudhury, Goutam Ghosh; Musi, Nicolas; DeFronzo, Ralph; Kasinath, Balakuntalam S

2014-02-01

Increase in matrix protein content in the kidney is a cardinal feature of diabetic kidney disease. While renal matrix protein content is increased by chronic hyperglycemia, whether it is regulated by acute elevation of glucose and insulin has not been addressed. In this study, we aimed to evaluate whether short duration of combined hyperglycemia and hyperinsulinemia, mimicking the metabolic environment of prediabetes and early type 2 diabetes, induces kidney injury. Normal rats were subjected to either saline infusion (control, n = 4) or 7 h of combined hyperglycemic-hyperinsulinemic clamp (HG+HI clamp; n = 6). During the clamp, plasma glucose and plasma insulin were maintained at about 350 mg/dl and 16 ng/ml, respectively. HG+HI clamp increased the expression of renal cortical transforming growth factor-β (TGF-β) and renal matrix proteins, laminin and fibronectin. This was associated with the activation of SMAD3, Akt, mammalian target of rapamycin (mTOR) complexes, and ERK signaling pathways and their downstream target events in the initiation and elongation phases of mRNA translation, an important step in protein synthesis. Additionally, HG+HI clamp provoked renal inflammation as shown by the activation of Toll-like receptor 4 (TLR4) and infiltration of CD68-positive monocytes. Urinary F2t isoprostane excretion, an index of renal oxidant stress, was increased in the HG+HI clamp rats. We conclude that even a short duration of hyperglycemia and hyperinsulinemia contributes to activation of pathways that regulate matrix protein synthesis, inflammation, and oxidative stress in the kidney. This finding could have implications for the control of short-term rises in blood glucose in diabetic individuals at risk of developing kidney disease.

Protein associations in DnaA-ATP hydrolysis mediated by the Hda-replicase clamp complex.

Science.gov (United States)

Su'etsugu, Masayuki; Shimuta, Toh-Ru; Ishida, Takuma; Kawakami, Hironori; Katayama, Tsutomu

2005-02-25

In Escherichia coli, the activity of ATP-bound DnaA protein in initiating chromosomal replication is negatively controlled in a replication-coordinated manner. The RIDA (regulatory inactivation of DnaA) system promotes DnaA-ATP hydrolysis to produce the inactivated form DnaA-ADP in a manner depending on the Hda protein and the DNA-loaded form of the beta-sliding clamp, a subunit of the replicase holoenzyme. A highly functional form of Hda was purified and shown to form a homodimer in solution, and two Hda dimers were found to associate with a single clamp molecule. Purified mutant Hda proteins were used in a staged in vitro RIDA system followed by a pull-down assay to show that Hda-clamp binding is a prerequisite for DnaA-ATP hydrolysis and that binding is mediated by an Hda N-terminal motif. Arg(168) in the AAA(+) Box VII motif of Hda plays a role in stable homodimer formation and in DnaA-ATP hydrolysis, but not in clamp binding. Furthermore, the DnaA N-terminal domain is required for the functional interaction of DnaA with the Hda-clamp complex. Single cells contain approximately 50 Hda dimers, consistent with the results of in vitro experiments. These findings and the features of AAA(+) proteins, including DnaA, suggest the following model. DnaA-ATP is hydrolyzed at a binding interface between the AAA(+) domains of DnaA and Hda; the DnaA N-terminal domain supports this interaction; and the interaction of DnaA-ATP with the Hda-clamp complex occurs in a catalytic mode.

Simplified method to evaluate seismic nozzle loads on mechanical equipment connected to unbraced piping

International Nuclear Information System (INIS)

Detroux, P.; Lafaille, J.P.

1991-01-01

After ten years of operation, the Belgian Nuclear Power Plants had to be seismically reassessed; especially, new requirements were imposed to the oldest units. The method, presented in this paper, is based on the principle that all the piping connected to the equipment is replaced by a clamped-hinged beam with or without concentrated mass and of a characteristic length depending on the diameter, schedule, mass per length of the connected piping and on the floor response spectra applicable at the location of the equipment. A theoretical justification of the method is presented for the simplest cases. The case of added concentrated mass is investigated. Finally, several comparisons with a full modal spectral analysis are presented

MEMS-based clamp with a passive hold function for precision position retaining of micro manipulators

International Nuclear Information System (INIS)

Brouwer, D M; Van Dijk, J; Soemers, H M J R; De Jong, B R; De Boer, M J; Jansen, H V; Krijnen, G J M

2009-01-01

In this paper the design, modeling and fabrication of a precision MEMS-based clamp with a relatively large clamping force are presented. The purpose of the clamp is to mechanically fix a six-degree-of-freedom (DOF) MEMS-based sample manipulator (Brouwer et al J. Int. Soc. Precis. Eng. Nanotechnol. submitted) once the sample has been positioned in all DOFs. The clamping force is generated by a rotational electrostatic comb-drive actuator and can be latched passively by a parallel plate type electrostatically driven locking device. The clamp design is based on the principles of exact constraint design, resulting in a high actuation compliance (flexibility) combined with a high suspension stiffness. Therefore, a relatively large blocking force of 1.4 mN in relation to the used area of 1.8 mm 2 is obtained. The fabrication is based on silicon bulk micromachining technology and combines a high-aspect-ratio deep reactive ion etching (DRIE), conformal deposition of low-pressure chemical vapor deposition (LPCVD) silicon nitride and an anisotropic potassium hydroxide (KOH) backside etching technology. Special attention is given to void reduction of Si x N y trench isolation and reduction of heating phenomena during front-side release etching. Guidelines are given for the applied process. Measurements showed that the clamp was able to fix, hold and release a test actuator. The dynamic behavior was in good agreement with the modal analysis

Hydrocarbon Induced Seismicity in Northern Netherlands

Science.gov (United States)

Dost, B.; Spetzler, J.; Kraaijpoel, D.; Caccavale, M.

2015-12-01

The northern Netherlands has been regarded aseismic until the first earthquakes started in 1986, after more than 25 years of gas production from the one of the largest on-shore gas-fields in the World, the Groningen field, and accompanying smaller gas fields. Due to the shallow sources, at approximately 3 km depth, even small magnitude events cause considerable damage to buildings in the region. Since the largest recorded event in the Groningen field in 2012 with ML= 3,6, more than 30.000 damage claims were received by the mining company. Since 1995 a seismic monitoring network is operational in the region, consisting of 8 200m deep boreholes with 4 levels of 3C 4,5 Hz geophones. The network was designed for a location threshold of ML=1,5 over a 40x 80 km region. Average station separation was 20 km. At the end of 2014, 245 events have been recorded with ML ≥ 1,5, out of a total of 1100. Since 2003 a new mining law is in place in the Netherlands, which requires for each gas field in production a seismic risk analysis. Initially, due to the small number of events for specific fields, a general hazard (PSHA) was calculated for all gas-fields and a maximum magnitude was estimated at ML = 3,9. Since 2003 an increase in the activity rate is observed for the Groningen field, leading to the development of new models and a re-assessment of parameters like the maximum magnitude. More recently these models are extended to seismic risk, where also the fragility of the regional buildings is taken into account. Understanding the earthquake process is essential in taking mitigation measures. Continued research is focused on reducing the uncertainties in the hazard and risk models and is accompanied by an upgrade of the monitoring network. In 2014 a new dense network was designed to monitor the Groningen gas field in this region (30*40 km) with an average separation of 4 km. This allows an improved location threshold (M>0,5) and location accuracy (50-100m). A detailed P- and S

Enhancing endogenous stem cells in the newborn via delayed umbilical cord clamping

Directory of Open Access Journals (Sweden)

Christopher Lawton

2015-01-01

Full Text Available There is currently no consensus among clinicians and scientists over the appropriate or optimal timing for umbilical cord clamping. However, many clinical studies have suggested that delayed cord clamping is associated with various neonatal benefits including increased blood volume, reduced need for blood transfusion, increased cerebral oxygenation in pre-term infants, and decreased frequency of iron deficiency anemia in term infants. Human umbilical cord blood contains significant amounts of stem and progenitor cells and is currently used in the treatment of several life-threatening diseases. We propose that delayed cord clamping be encouraged as it enhances blood flow from the placenta to the neonate, which is accompanied by an increase supply of valuable stem and progenitor cells, as well as may improve blood oxygenation and increase blood volume, altogether reducing the infant′s susceptibility to both neonatal and age-related diseases.

The evaluation on clamping force of high strength bolts by length parameter

International Nuclear Information System (INIS)

Kim, Kang-Seok; Nah, Hwan-Seon; Lee, Hyeon-Ju; Lee, Kang-Min

2009-01-01

It has been reported that the length parameter of high strength bolts results in the variance in tension loads. The required turn for each length is specified in AISC RCSC specification. This study was focused on evaluating any influence on the clamping torque subjected to length parameter of high strength bolts. The two kinds of high strength bolts of specimen are as follows; High Strength Hexagon bolt defined on ASTM A490 and Torque Shear Bolt on KS B 2819. The length parameter ranged from 60mm(3d) to 140mm(7d). The torque, turn of nut and the clamping force were analyzed to review whether length parameter can be affected on the required tension load. To test whether the length parameter has an impact on the torque and turn of nut for the required strength and clamping force, statistical analysis is carried out. (author)

Thermodynamic basis for engineering high-affinity, high-specificity binding-induced DNA clamp nanoswitches.

Science.gov (United States)

Idili, Andrea; Plaxco, Kevin W; Vallée-Bélisle, Alexis; Ricci, Francesco

2013-12-23

Naturally occurring chemoreceptors almost invariably employ structure-switching mechanisms, an observation that has inspired the use of biomolecular switches in a wide range of artificial technologies in the areas of diagnostics, imaging, and synthetic biology. In one mechanism for generating such behavior, clamp-based switching, binding occurs via the clamplike embrace of two recognition elements onto a single target molecule. In addition to coupling recognition with a large conformational change, this mechanism offers a second advantage: it improves both affinity and specificity simultaneously. To explore the physics of such switches we have dissected here the thermodynamics of a clamp-switch that recognizes a target DNA sequence through both Watson-Crick base pairing and triplex-forming Hoogsteen interactions. When compared to the equivalent linear DNA probe (which relies solely on Watson-Crick interactions), the extra Hoogsteen interactions in the DNA clamp-switch increase the probe's affinity for its target by ∼0.29 ± 0.02 kcal/mol/base. The Hoogsteen interactions of the clamp-switch likewise provide an additional specificity check that increases the discrimination efficiency toward a single-base mismatch by 1.2 ± 0.2 kcal/mol. This, in turn, leads to a 10-fold improvement in the width of the "specificity window" of this probe relative to that of the equivalent linear probe. Given these attributes, clamp-switches should be of utility not only for sensing applications but also, in the specific field of DNA nanotechnology, for applications calling for a better control over the building of nanostructures and nanomachines.

Seismic isolation - efficient procedure for seismic response assessement

International Nuclear Information System (INIS)

Zamfir, M. A.; Androne, M.

2016-01-01

The aim of this analysis is to reduce the dynamic response of a structure. The seismic isolation solution must take into consideration the specific site ground motion. In this paper will be presented results obtained by applying the seismic isolation method. Based on the obtained results, important conclusions can be outlined: the seismic isolation device has the ability to reduce seismic acceleration of the seismic isolated structure to values that no longer present a danger to people and environment; the seismic isolation solution is limiting devices deformations to safety values for ensuring structural integrity and stability of the entire system; the effective seismic energy dissipation and with no side effects both for the seismic isolated building and for the devices used, and the return to the initial position before earthquake occurence are obtained with acceptable permanent displacement. (authors)

Reversible fastener clamp load monitor with continuous visual or remote readout

Science.gov (United States)

Hodge, Malcolm H.; Kausel, Theodore C., Jr.; Begley, Matthew R.

1998-03-01

SIMS has developed a simple means for detecting and monitoring both absolute and relative clamp load, or bolt tension, in fastener systems. More than twenty-five percent of automotive failures are known to be due to undetected loss of fastener clamp load. While the equivalent aerospace maintenance statistics are not known, the average automobile has 3,500 fasteners while a Boeing 747 has closer to one million. It is therefore anticipated that the new SensaBolt clamp load tracking system could find wide applications in the aerospace arena. We describe a visually-evident and retrofitted clamp load monitoring design which is based on the differential joint substrate compression at, and immediately adjacent to, the fastener location. This intrinsically-accurate indicator does not necessarily require alteration in either the bolt or nut geometries, thereby facilitating product introduction and retrofit in aging aircraft applications. In addition, SensaBolt's sole reliance on substrate compression renders it more accurate then torque wrench or turn-of-nut techniques. Readout may be accomplished by any of three principal methods: for those applications with ease of access to the sensor, loss of tension can be determined by direct visual inspection. Application of a standard wrench can then be made to restore the fastener's proper tightness, per the SensaBolt indicators. In those instances where line-of-sight is unimpeded and more formal inspection is desired, the SensaBolt may be interrogated by a laser scanner bar code reader. Finally, SensaBolt may be addressed by the SIMS fiber optic harness for those instances where full-time remote interrogation is desired.

A simple technique to measure regional cerebral blood flow during intravascular ballon clamping

International Nuclear Information System (INIS)

Furuhata, Shigeru; Kubo, Atsushi; Kawase, Takeshi; Ibata, Yukio; Toya, Shigeo

1988-01-01

A case of giant internal carotid ophthalmic aneurysm was presented. In order to clarify whether the patient could tolerate carotid occlusion, a ballon clamping test was performed before surgery. The cerebral blood flow was measured using early imaging by single photon emission computed tomography (SPECT) with N-isopropyl-(iodine-123)-p-iodoamphetamine ( 123 I-IMP). When the ballon clamping test was performed the tracer was injected, and scanning was performed 35 minutes after removing the catheter. This tracer enabled a 'memory of blood flow' during temporary ischemia to determine the character of quick diffusion and slow wash out, that could not be performed by other methods of cerebral blood flow measurement. SPECT with 123 I-IMP can simplify the measurement of cerebral blood flow during the balloon clamping test. (author)

Interactions Between SNAP-25 and Synaptotagmin-1 Are Involved in Vesicle Priming, Clamping Spontaneous and Stimulating Evoked Neurotransmission

DEFF Research Database (Denmark)

Schupp, Melanie; Malsam, Jörg; Ruiter, Marvin

2016-01-01

between region I (vesicle priming) and region II (evoked release). Spontaneous release was disinhibited by region I mutations and found to correlate with defective complexin (Cpx) clamping in an in vitro fusion assay, pointing to an interdependent role of synaptotagmin and Cpx in release clamping...... triggering, depend on direct SNARE complex interaction. SIGNIFICANCE STATEMENT: The function of synaptotagmin-1 (syt-1):soluble NSF attachment protein receptor (SNARE) interactions during neurotransmission remains unclear. We mutated SNAP-25 within the recently identified region I and region II...... was disinhibited by region I mutation and found to correlate with defective complexin (Cpx) clamping in vitro, pointing to an interdependent role of synaptotagmin and Cpx in release clamping. Therefore, vesicle priming, clamping spontaneous release, and eliciting evoked release are three different functions of syt...

Seismic testing

International Nuclear Information System (INIS)

Sollogoub, Pierre

2001-01-01

This lecture deals with: qualification methods for seismic testing; objectives of seismic testing; seismic testing standards including examples; main content of standard; testing means; and some important elements of seismic testing

Applications of Dynamic Clamp to Cardiac Arrhythmia Research: Role in Drug Target Discovery and Safety Pharmacology Testing

Directory of Open Access Journals (Sweden)

Francis A. Ortega

2018-01-01

Full Text Available Dynamic clamp, a hybrid-computational-experimental technique that has been used to elucidate ionic mechanisms underlying cardiac electrophysiology, is emerging as a promising tool in the discovery of potential anti-arrhythmic targets and in pharmacological safety testing. Through the injection of computationally simulated conductances into isolated cardiomyocytes in a real-time continuous loop, dynamic clamp has greatly expanded the capabilities of patch clamp outside traditional static voltage and current protocols. Recent applications include fine manipulation of injected artificial conductances to identify promising drug targets in the prevention of arrhythmia and the direct testing of model-based hypotheses. Furthermore, dynamic clamp has been used to enhance existing experimental models by addressing their intrinsic limitations, which increased predictive power in identifying pro-arrhythmic pharmacological compounds. Here, we review the recent advances of the dynamic clamp technique in cardiac electrophysiology with a focus on its future role in the development of safety testing and discovery of anti-arrhythmic drugs.

seismic-py: Reading seismic data with Python

Directory of Open Access Journals (Sweden)

2008-08-01

Full Text Available The field of seismic exploration of the Earth has changed
dramatically over the last half a century. The Society of Exploration
Geophysicists (SEG has worked to create standards to store the vast
amounts of seismic data in a way that will be portable across computer
architectures. However, it has been impossible to predict the needs of the
immense range of seismic data acquisition systems. As a result, vendors have
had to bend the rules to accommodate the needs of new instruments and
experiment types. For low level access to seismic data, there is need for a
standard open source library to allow access to a wide range of vendor data
files that can handle all of the variations. A new seismic software package,
seismic-py, provides an infrastructure for creating and managing drivers for
each particular format. Drivers can be derived from one of the known formats
and altered to handle any slight variations. Alternatively drivers can be
developed from scratch for formats that are very different from any previously
defined format. Python has been the key to making driver development easy
and efficient to implement. The goal of seismic-py is to be the base system
that will power a wide range of experimentation with seismic data and at the
same time provide clear documentation for the historical record of seismic
data formats.

Harsh-Environment Solid-State Gamma Detector for Down-hole Gas and Oil Exploration

International Nuclear Information System (INIS)

Peter Sandvik; Stanislav Soloviev; Emad Andarawis; Ho-Young Cha; Jim Rose; Kevin Durocher; Robert Lyons; Bob Pieciuk; Jim Williams; David O'Connor

2007-01-01

The goal of this program was to develop a revolutionary solid-state gamma-ray detector suitable for use in down-hole gas and oil exploration. This advanced detector would employ wide-bandgap semiconductor technology to extend the gamma sensor's temperature capability up to 200 C as well as extended reliability, which significantly exceeds current designs based on photomultiplier tubes. In Phase II, project tasks were focused on optimization of the final APD design, growing and characterizing the full scintillator crystals of the selected composition, arranging the APD device packaging, developing the needed optical coupling between scintillator and APD, and characterizing the combined elements as a full detector system preparing for commercialization. What follows is a summary report from the second 18-month phase of this program

Small Molecules for Early Endosome-Specific Patch Clamping.

Science.gov (United States)

Chen, Cheng-Chang; Butz, Elisabeth S; Chao, Yu-Kai; Grishchuk, Yulia; Becker, Lars; Heller, Stefan; Slaugenhaupt, Susan A; Biel, Martin; Wahl-Schott, Christian; Grimm, Christian

2017-07-20

To resolve the subcellular distribution of endolysosomal ion channels, we have established a novel experimental approach to selectively patch clamp Rab5 positive early endosomes (EE) versus Rab7/LAMP1-positive late endosomes/lysosomes (LE/LY). To functionally characterize ion channels in endolysosomal membranes with the patch-clamp technique, it is important to develop techniques to selectively enlarge the respective organelles. We found here that two small molecules, wortmannin and latrunculin B, enlarge Rab5-positive EE when combined but not Rab7-, LAMP1-, or Rab11 (RE)-positive vesicles. The two compounds act rapidly, specifically, and are readily applicable in contrast to genetic approaches or previously used compounds such as vacuolin, which enlarges EE, RE, and LE/LY. We apply this approach here to measure currents mediated by TRPML channels, in particular TRPML3, which we found to be functionally active in both EE and LE/LY in overexpressing cells as well as in endogenously expressing CD11b+ lung-tissue macrophages. Copyright © 2017 Elsevier Ltd. All rights reserved.

Seismic damping factors of small-bore piping as influenced by insulation and support elements

International Nuclear Information System (INIS)

Severud, L.K.; Anderson, M.J.; Barta, D.A.

1983-01-01

Seismic damping tests of a prototypical Liquid Metal Fast Breeder Reactor (LMFBR) small-bore piping system is described, and measured transient responses to pulse excitations are reported. The test specimen was representative of a typical LMFBR insulated small-bore piping system, and it was supported from a rigid test fame by prototypic dead-weight supports, mechanical snubbers, and pipe clamps. Various support configurations were tested to assess the reponse sensitivity to insulation and use of mechanical snubbers. Factors much higher than the magnitudes currently allowed in design, by the USNRC Regulatory Guide 1.61, were found. This verified the design values but also pointed out the possibility of undue conservatism and costly overdesign resulting from use of the present design values

Downhole microseismic signal-to-noise ratio enhancement via strip matching shearlet transform

Science.gov (United States)

Li, Juan; Ji, Shuo; Li, Yue; Qian, Zhihong; Lu, Weili

2018-04-01

Shearlet transform has been proved effective in noise attenuation. However, because of the low magnitude and high frequency of downhole microseismic signals, the coefficient values of valid signals and noise are similar in the shearlet domain. As a result, it is hard to suppress the noise. In this paper, we present a novel signal-to-noise ratio enhancement scheme called strip matching shearlet transform. The method takes into account the directivity of microseismic events and shearlets. Through strip matching, the matching degree in direction between them has been promoted. Then the coefficient values of valid signals are much larger than those of the noise. Consequently, we can separate them well with the help of thresholding. The experimental results on both synthetic records and field data illustrate that our proposed method preserves the useful components and attenuates the noise well.

Long-Time Choledochal Clamping in Wistar Rats Causes Biliary Obstruction Progressing to Hepatic Fibrosis.

Science.gov (United States)

Jorge, G D L; Tártaro, R R; Escanhoela, C A F; Boin, I D F S F

2016-09-01

Biliary complications are important causes of morbidity and mortality in patients undergoing hepatic surgery. The aim of the study was to evaluate late liver alterations after a long period of choledochal clamping in Wistar rats. Ten male Wistar rats, weighing 304 grams, anesthetized with sodium thiopental (25 mg/kg) and xylazine (10 mg/kg) intravenously, were distributed into 2 groups: the choledochal clamping group (CCG) and the operation sham group (OSG), with 5 animals each submitted to an abdominal incision. In the CCG, the choledochal was isolated, dissected, and clamped with a microvascular clamp for 40 minutes. After this occlusion time, the clamp was removed and the incision was closed. In the OSG the animals, under normal conditions, were submitted only to anesthesia and laparotomy for choledochal manipulation. In all animals, after the 31st day, a hepatic biopsy was carried out for histology and blood biochemical tests: total bilirubin, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, and gamma-glutamyl transferase. The animals were euthanized under anesthesia. This research was approved by the Ethics Committee on Animal Use (CEUA, Unicamp, No. 2511-1). In the CCG, 100% of the animals showed bile duct dilatation, ductular proliferation, and portal inflammatory infiltrate; 60% showed regenerative nodule formation; and 80% had porta-porta septa and foci of necrosis, all of which were not found in the OSG. All CCG group biochemical tests had significant increases (P Wistar rats caused hepatic dysfunction and biochemical and histological injuries with degrees of distortion to the hepatic architecture. Copyright © 2016 Elsevier Inc. All rights reserved.

Non-Invasive Seismic Methods for Earthquake Site Classification Applied to Ontario Bridge Sites

Science.gov (United States)

Bilson Darko, A.; Molnar, S.; Sadrekarimi, A.

2017-12-01

How a site responds to earthquake shaking and its corresponding damage is largely influenced by the underlying ground conditions through which it propagates. The effects of site conditions on propagating seismic waves can be predicted from measurements of the shear wave velocity (Vs) of the soil layer(s) and the impedance ratio between bedrock and soil. Currently the seismic design of new buildings and bridges (2015 Canadian building and bridge codes) requires determination of the time-averaged shear-wave velocity of the upper 30 metres (Vs30) of a given site. In this study, two in situ Vs profiling methods; Multichannel Analysis of Surface Waves (MASW) and Ambient Vibration Array (AVA) methods are used to determine Vs30 at chosen bridge sites in Ontario, Canada. Both active-source (MASW) and passive-source (AVA) surface wave methods are used at each bridge site to obtain Rayleigh-wave phase velocities over a wide frequency bandwidth. The dispersion curve is jointly inverted with each site's amplification function (microtremor horizontal-to-vertical spectral ratio) to obtain shear-wave velocity profile(s). We apply our non-invasive testing at three major infrastructure projects, e.g., five bridge sites along the Rt. Hon. Herb Gray Parkway in Windsor, Ontario. Our non-invasive testing is co-located with previous invasive testing, including Standard Penetration Test (SPT), Cone Penetration Test and downhole Vs data. Correlations between SPT blowcount and Vs are developed for the different soil types sampled at our Ontario bridge sites. A robust earthquake site classification procedure (reliable Vs30 estimates) for bridge sites across Ontario is evaluated from available combinations of invasive and non-invasive site characterization methods.

[Time of cord clamping and neonatal complications, a prospective study].

Science.gov (United States)

Rincón, D; Foguet, A; Rojas, M; Segarra, E; Sacristán, E; Teixidor, R; Ortega, A

2014-09-01

To assess the effects of early or late clamping of the umbilical cord in term newborns, assessing the levels of hemoglobin, hematocrit, and ferritin, and their correlation with some of the complications. A prospective study of healthy newborns at term or born by dystotic or eutocic delivery in our hospital between May 2009 until May 2010. Patients were assigned according to the time of clamping, group 1 (<60 seconds), group 2 (1 to<2 minutes), and group 3 (2 to 3 minutes). Laboratory tests were performed at birth and at 48 hours of life, assessing the levels of hemoglobin, hematocrit, ferritin, and bilirubin. The risk of polycythemia, respiratory distress syndrome, neonatal phototherapy or admission to the Intensive Care Unit and the hospital stay, were evaluated. A total of 242 patients were included: group 1 (g1=80), group 2 (g2=31) y group 3 (g3=131). The background maternal and neonatal characteristics were similar in all sets. The first test showed significant differences in ferritin levels in those infants with delayed clamping (g1: 111 mg/dl, g2: 125 mg/dl, g3: 173 mg/dl; p<0.01). In the second analysis the values of hemoglobin (g1: 17.3 g/dl, g2: 18.9 g/dl, g3: 19.2 g/dl; p<0.01), hematocrit (g1: 53.4%, g2: 58%, g3: 59%; p<0.01) and ferritin (g1: 254 mg/dl, g2: 254.7 mg/dl, g3: 313 mg/dl; p = 0.008) were statistically higher in this group. As regards complications, a significant increase was observed in the number of cases of polycythemia symptoms in group 3. The late cord clamping is associated with an increase in hematocrit, hemoglobin and ferritin at 48 hours of life, as well as an increased risk of polycythemia present with symptoms. Copyright © 2013 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

Robotic multi-well planar patch-clamp for native and primary mammalian cells

Science.gov (United States)

Milligan, Carol J; Li, Jing; Sukumar, Piruthivi; Majeed, Yasser; Dallas, Mark L; English, Anne; Emery, Paul; Porter, Karen E; Smith, Andrew M; McFadzean, Ian; Beccano-Kelly, Dayne; Bahnasi, Yahya; Cheong, Alex; Naylor, Jacqueline; Zeng, Fanning; Liu, Xing; Gamper, Nikita; Jiang, Lin-Hua; Pearson, Hugh A; Peers, Chris; Robertson, Brian; Beech, David J

2009-01-01

Multi-well robotic planar patch-clamp has become common in drug development and safety programmes because it enables efficient and systematic testing of compounds against ion channels during voltage-clamp. It has not, however, been adopted significantly in other important areas of ion channel research, where conventional patch-clamp remains the favoured method. Here we show the wider potential of the multi-well approach with the capability for efficient intracellular solution exchange, describing protocols and success rates for recording from a range of native and primary mammalian cells derived from blood vessels, arthritic joints, and the immune and central nervous systems. The protocol involves preparing a suspension of single cells to be dispensed robotically into 4-8 microfluidic chambers each containing a glass chip with a small aperture. Under automated control, giga-seals and whole-cell access are achieved followed by pre-programmed routines of voltage paradigms and fast extracellular or intracellular solution exchange. Recording from 48 chambers usually takes 1-6 hr depending on the experimental design and yields 16-33 cell recordings. PMID:19197268

IODP Expedition 340T: Borehole Logging at Atlantis Massif Oceanic Core Complex

Directory of Open Access Journals (Sweden)

Donna Blackman

2013-03-01

Full Text Available Integrated Ocean Drilling Program (IODP Expedition 340T returned to the 1.4-km-deep Hole U1309D at Atlantis Massif to carry out borehole logging including vertical seismic profiling (VSP. Seismic, resistivity, and temperature logs were obtained throughout the geologic section in the footwall of this oceanic core complex. Reliable downhole temperature measurements throughout and the first seismic coverage of the 800–1400 meters below seafloor (mbsf portionof the section were obtained. Distinct changes in velocity, resistivity, and magnetic susceptibility characterize the boundaries of altered, olivine-rich troctolite intervals within the otherwise dominantly gabbroic se-quence. Some narrow fault zones also are associated with downhole resistivity or velocity excursions. Small deviations in temperature were measured in borehole fluid adjacent to known faults at 750 mbsf and 1100 mbsf. This suggests that flow of seawater remains active along these zones of faulting and rock alteration. Vertical seismic profile station coverage at zero offsetnow extends the full length of the hole, including the uppermost 150 mbsf, where detachment processes are expected to have left their strongest imprint. Analysis of wallrock properties, together with alteration and structural characteristics of the cores from Site U1309, highlights the likely interplay between lithology, structure, lithospheric hydration, and core complex evolution.

Modeling error and apparent isotope discrimination confound estimation of endogenous glucose production during euglycemic glucose clamps

International Nuclear Information System (INIS)

Finegood, D.T.; Bergman, R.N.; Vranic, M.

1988-01-01

We previously demonstrated that conventional tracer methods applied to euglycemic-hyperinsulinemic glucose clamps result in substantially negative estimates for the rate of endogenous glucose production, particularly during the first half of 180-min clamps. We also showed that addition of tracer to the exogenous glucose infusate resulted in nonnegative endogenous glucose production (Ra) estimates. In this study, we investigated the underlying cause of negative estimates of Ra from conventional clamp/tracer methods and the reason for the difference in estimates when tracer is added to the exogenous glucose infusate. We performed euglycemic-hyperinsulinemic (300-microU/ml) clamps in normal dogs without (cold GINF protocol, n = 6) or with (hot GINF protocol, n = 6) tracer (D-[3-3H]glucose) added to the exogenous glucose infusate. In the hot GINF protocol, sufficient tracer was added to the exogenous glucose infusate such that arterial plasma specific activity (SAa) did not change from basal through the clamp period (P greater than .05). In the cold GINF studies, plasma SAa fell 81 +/- 2% from the basal level by the 3rd h of clamping. We observed a significant, transient, positive venous-arterial difference in specific activity (SAv-SAa difference) during the cold GINF studies. The SAv-SAa difference reached a peak of 27 +/- 6% at 30 min and diminished to a plateau of 7 +/- 1% between 70 and 180 min. We also observed a positive but constant SAv-SAa difference (4.6 +/- 0.2% between 10 and 180 min) during the hot GINF studies

Inertial piezoelectric linear motor driven by a single-phase harmonic wave with automatic clamping mechanism

Science.gov (United States)

He, Liangguo; Chu, Yuheng; Hao, Sai; Zhao, Xiaoyong; Dong, Yuge; Wang, Yong

2018-05-01

A novel, single-phase, harmonic-driven, inertial piezoelectric linear motor using an automatic clamping mechanism was designed, fabricated, and tested to reduce the sliding friction and simplify the drive mechanism and power supply control of the inertial motor. A piezoelectric bimorph and a flexible hinge were connected in series to form the automatic clamping mechanism. The automatic clamping mechanism was used as the driving and clamping elements. A dynamic simulation by Simulink was performed to prove the feasibility of the motor. The finite element method software COMSOL was used to design the structure of the motor. An experimental setup was built to validate the working principle and evaluate the performance of the motor. The prototype motor outputted a no-load velocity of 3.178 mm/s at a voltage of 220 Vp-p and a maximum traction force of 4.25 N under a preload force of 8 N. The minimum resolution of 1.14 μm was achieved at a driving frequency of 74 Hz, a driving voltage of 50 Vp-p, and a preload force of 0 N.

Safety of minimally invasive mitral valve surgery without aortic cross-clamp.

Science.gov (United States)

Umakanthan, Ramanan; Leacche, Marzia; Petracek, Michael R; Kumar, Sathappan; Solenkova, Nataliya V; Kaiser, Clayton A; Greelish, James P; Balaguer, Jorge M; Ahmad, Rashid M; Ball, Stephen K; Hoff, Steven J; Absi, Tarek S; Kim, Betty S; Byrne, John G

2008-05-01

We developed a technique for open heart surgery through a small (5 cm) right-anterolateral thoracotomy without aortic cross-clamp. One hundred and ninety-five consecutive patients (103 male and 92 female), age 69 +/- 8 years, underwent surgery between January 2006 and July 2007. Mean preoperative New York Heart Association function class was 2.2 +/- 0.7. Thirty-five patients (18%) had an ejection fraction 0.35 or less. Cardiopulmonary bypass was instituted through femoral (176 of 195, 90%), axillary (18 of 195, 9%), or direct aortic (1 of 195, 0.5%) cannulation. Under cold fibrillatory arrest (mean temperature 28.2 degrees C) without aortic cross-clamp, mitral valve repair (72 of 195, 37%), mitral valve replacement (117 of 195, 60%), or other (6 of 195, 3%) procedures were performed. Concomitant procedures included maze (45 of 195, 23%), patent foramen ovale closure (42 of 195, 22%) and tricuspid valve repair (16 of 195, 8%), or replacement (4 of 195, 2%). Thirty-day mortality was 3% (6 of 195). Duration of fibrillatory arrest, cardiopulmonary bypass, and "skin to skin" surgery were 88 +/- 32, 118 +/- 52, and 280 +/- 78 minutes, respectively. Ten patients (5%) underwent reexploration for bleeding and 44% did not receive any blood transfusions. Six patients (3%) sustained a postoperative stroke, eight (4%) developed low cardiac output syndrome, and two (1%) developed renal failure requiring hemodialysis. Mean length of hospital stay was 7 +/- 4.8 days. This simplified technique of minimally invasive open heart surgery is safe and easily reproducible. Fibrillatory arrest without aortic cross-clamping, with coronary perfusion against an intact aortic valve, does not increase the risk of stroke or low cardiac output. It may be particularly useful in higher risk patients in whom sternotomy with aortic clamping is less desirable.

Study on structural seismic margin and probabilistic seismic risk. Development of a structural capacity-seismic risk diagram

International Nuclear Information System (INIS)

Nakajima, Masato; Ohtori, Yasuki; Hirata, Kazuta

2010-01-01

Seismic margin is extremely important index and information when we evaluate and account seismic safety of critical structures, systems and components quantitatively. Therefore, it is required that electric power companies evaluate the seismic margin of each plant in back-check of nuclear power plants in Japan. The seismic margin of structures is usually defined as a structural capacity margin corresponding to design earthquake ground motion. However, there is little agreement as to the definition of the seismic margin and we have no knowledge about a relationship between the seismic margin and seismic risk (annual failure probability) which is obtained in PSA (Probabilistic Safety Assessment). The purpose of this report is to discuss a definition of structural seismic margin and to develop a diagram which can identify a relation between seismic margin and seismic risk. The main results of this paper are described as follows: (1) We develop seismic margin which is defined based on the fact that intensity of earthquake ground motion is more appropriate than the conventional definition (i.e., the response-based seismic margin) for the following reasons: -seismic margin based on earthquake ground motion is invariant where different typed structures are considered, -stakeholders can understand the seismic margin based on the earthquake ground motion better than the response-based one. (2) The developed seismic margin-risk diagram facilitates us to judge easily whether we need to perform detailed probabilistic risk analysis or only deterministic analysis, given that the reference risk level although information on the uncertainty parameter beta is not obtained. (3) We have performed numerical simulations based on the developed method for four sites in Japan. The structural capacity-risk diagram differs depending on each location because the diagram is greatly influenced by seismic hazard information for a target site. Furthermore, the required structural capacity

Interpretation of Microseismicity Observed From Surface and Borehole Seismic Arrays During Hydraulic Fracturing in Shale - Bedding Plane Slip Model

Science.gov (United States)

Stanek, F.; Jechumtalova, Z.; Eisner, L.

2017-12-01

We present a geomechanical model explaining microseismicity induced by hydraulic fracturing in shales developed from many datasets acquired with two most common types of seismic monitoring arrays, surface and dual-borehole arrays. The geomechanical model explains the observed source mechanisms and locations of induced events from two stimulated shale reservoirs. We observe shear dip-slip source mechanisms with nodal planes aligned with location trends. We show that such seismicity can be explained as a shearing along bedding planes caused by aseismic opening of vertical hydraulic fractures. The source mechanism inversion was applied only to selected high-quality events with sufficient signal-to-noise ratio. We inverted P- and P- and S-wave arrival amplitudes to full-moment tensor and decomposed it to shear, volumetric and compensated linear vector dipole components. We also tested an effect of noise presented in the data to evaluate reliability of non-shear components. The observed seismicity from both surface and downhole monitoring of shale stimulations is very similar. The locations of induced microseismic events are limited to narrow depth intervals and propagate along distinct trend(s) showing fracture propagation in direction of maximum horizontal stress from injection well(s). The source mechanisms have a small non-shear component which can be partly explained as an effect of noise in the data, i.e. events represent shearing on faults. We observe predominantly dip-slip events with a strike of the steeper (almost vertical) nodal plane parallel to the fracture propagation. Therefore the other possible nodal plane is almost horizontal. The rake angles of the observed mechanisms divide these dip-slips into two groups with opposite polarities. It means that we observe opposite movements on the nearly identically oriented faults. Realizing a typical structural weakness of shale in horizontal planes, we interpret observed microseismicity as a result of shearing

Seismic Ecology

Science.gov (United States)

Seleznev, V. S.; Soloviev, V. M.; Emanov, A. F.

The paper is devoted to researches of influence of seismic actions for industrial and civil buildings and people. The seismic actions bring influence directly on the people (vibration actions, force shocks at earthquakes) or indirectly through various build- ings and the constructions and can be strong (be felt by people) and weak (be fixed by sensing devices). The great number of work is devoted to influence of violent seismic actions (first of all of earthquakes) on people and various constructions. This work is devoted to study weak, but long seismic actions on various buildings and people. There is a need to take into account seismic oscillations, acting on the territory, at construction of various buildings on urbanized territories. Essential influence, except for violent earthquakes, man-caused seismic actions: the explosions, seismic noise, emitted by plant facilities and moving transport, radiation from high-rise buildings and constructions under action of a wind, etc. can exert. Materials on increase of man- caused seismicity in a number of regions in Russia, which earlier were not seismic, are presented in the paper. Along with maps of seismic microzoning maps to be built indicating a variation of amplitude spectra of seismic noise within day, months, years. The presence of an information about amplitudes and frequencies of oscillations from possible earthquakes and man-caused oscillations in concrete regions allows carry- ing out soundly designing and construction of industrial and civil housing projects. The construction of buildings even in not seismically dangerous regions, which have one from resonance frequencies coincident on magnitude to frequency of oscillations, emitted in this place by man-caused objects, can end in failure of these buildings and heaviest consequences for the people. The practical examples of detail of engineering- seismological investigation of large industrial and civil housing projects of Siberia territory (hydro power

Axially Modulated Clamped-Guided Arch Resonator for Memory and Logic Applications

KAUST Repository

Hafiz, Md Abdullah Al; Tella, Sherif Adekunle; Alcheikh, Nouha; Fariborzi, Hossein; Younis, Mohammad I.

2017-01-01

We experimentally demonstrate memory and logic devices based on an axially modulated clamped-guided arch resonator. The device are electrostatically actuated and capacitively sensed, while the resonance frequency modulation is achieved through an axial electrostatic force from the guided side of the clamped-guided arch microbeam. We present two case studies: first, a dynamic memory based on the nonlinear frequency response of the resonator, and second, a reprogrammable two-input logic gate based on the linear frequency modulation of the resonator. These devices show energy cost per memory/logic operation in pJ, are fully compatible with CMOS fabrication processes, have the potential for on-chip system integration, and operate at room temperature.

Axially Modulated Clamped-Guided Arch Resonator for Memory and Logic Applications

KAUST Repository

Hafiz, Md Abdullah Al

2017-11-03

We experimentally demonstrate memory and logic devices based on an axially modulated clamped-guided arch resonator. The device are electrostatically actuated and capacitively sensed, while the resonance frequency modulation is achieved through an axial electrostatic force from the guided side of the clamped-guided arch microbeam. We present two case studies: first, a dynamic memory based on the nonlinear frequency response of the resonator, and second, a reprogrammable two-input logic gate based on the linear frequency modulation of the resonator. These devices show energy cost per memory/logic operation in pJ, are fully compatible with CMOS fabrication processes, have the potential for on-chip system integration, and operate at room temperature.

Integral transform solution of bending problem of clamped orthotropic rectangular plates

International Nuclear Information System (INIS)

An, C.; Gu, J.-J.; Su, J.

2011-01-01

The generalized integral transform technique (GITT) is employed to obtain an exact solution for the bending problem of fully clamped orthotropic rectangular plates. The use of the GITT approach in the analysis of the transverse deflection equation leads to a coupled system of fourth order differential equations in the dimensionless longitudinal spatial variable. The resulting transformed ODE system is then numerically solved by making use of the subroutine DBVPFD from IMSL Library. Numerical results with automatic global accuracy control are produced for different values of aspect ratio. Critical comparisons with previously reported numerical results are performed with excellent agreement. Several sets of reference results for clamped orthotropic rectangular plates are also provided for future covalidation purposes. (author)

Gigaseal formation in patch clamping with applications of nanotechnology

CERN Document Server

Malboubi, Majid

2014-01-01

This book presents an investigation of gigaseal formation using micro/nanotechnology. The aims of the book are twofold. First, it explains the mechanisms of gigaseal formation using the latest discoveries. Second, it provides practical techniques for frequent formation of high resistance seals. The formation of a high-resistance electrical seal, also known as a gigaseal, between a cell membrane and a glass micropipette tip is essential in patch-clamp experiments. Even though four decades have passed since the introduction of the patch-clamping technique by Neher and Sakmann, gigaseal formation remains an obstacle in developing the high-throughput ion channel screening systems required by the pharmaceutical industry. Here the authors share their latest methods for achieving gigaseal formation and describe techniques that are highly desirable at both research and industrial levels. Nanotechnology has been found to be a powerful tool for studying and modifying glass micropipettes and in tackling the problem of g...

Harsh-Environment Solid-State Gamma Detector for Down-hole Gas and Oil Exploration

Energy Technology Data Exchange (ETDEWEB)

Peter Sandvik; Stanislav Soloviev; Emad Andarawis; Ho-Young Cha; Jim Rose; Kevin Durocher; Robert Lyons; Bob Pieciuk; Jim Williams; David O' Connor

2007-08-10

The goal of this program was to develop a revolutionary solid-state gamma-ray detector suitable for use in down-hole gas and oil exploration. This advanced detector would employ wide-bandgap semiconductor technology to extend the gamma sensor's temperature capability up to 200 C as well as extended reliability, which significantly exceeds current designs based on photomultiplier tubes. In Phase II, project tasks were focused on optimization of the final APD design, growing and characterizing the full scintillator crystals of the selected composition, arranging the APD device packaging, developing the needed optical coupling between scintillator and APD, and characterizing the combined elements as a full detector system preparing for commercialization. What follows is a summary report from the second 18-month phase of this program.

Downhole fluid injection systems, CO2 sequestration methods, and hydrocarbon material recovery methods

Science.gov (United States)

Schaef, Herbert T.; McGrail, B. Peter

2015-07-28

Downhole fluid injection systems are provided that can include a first well extending into a geological formation, and a fluid injector assembly located within the well. The fluid injector assembly can be configured to inject a liquid CO2/H2O-emulsion into the surrounding geological formation. CO2 sequestration methods are provided that can include exposing a geological formation to a liquid CO2/H2O-emulsion to sequester at least a portion of the CO2 from the emulsion within the formation. Hydrocarbon material recovery methods are provided that can include exposing a liquid CO2/H2O-emulsion to a geological formation having the hydrocarbon material therein. The methods can include recovering at least a portion of the hydrocarbon material from the formation.

Automated patch clamp on mESC-derived cardiomyocytes for cardiotoxicity prediction.

Science.gov (United States)

Stoelzle, Sonja; Haythornthwaite, Alison; Kettenhofen, Ralf; Kolossov, Eugen; Bohlen, Heribert; George, Michael; Brüggemann, Andrea; Fertig, Niels

2011-09-01

Cardiovascular side effects are critical in drug development and have frequently led to late-stage project terminations or even drug withdrawal from the market. Physiologically relevant and predictive assays for cardiotoxicity are hence strongly demanded by the pharmaceutical industry. To identify a potential impact of test compounds on ventricular repolarization, typically a variety of ion channels in diverse heterologously expressing cells have to be investigated. Similar to primary cells, in vitro-generated stem cell-derived cardiomyocytes simultaneously express cardiac ion channels. Thus, they more accurately represent the native situation compared with cell lines overexpressing only a single type of ion channel. The aim of this study was to determine if stem cell-derived cardiomyocytes are suited for use in an automated patch clamp system. The authors show recordings of cardiac ion currents as well as action potential recordings in readily available stem cell-derived cardiomyocytes. Besides monitoring inhibitory effects of reference compounds on typical cardiac ion currents, the authors revealed for the first time drug-induced modulation of cardiac action potentials in an automated patch clamp system. The combination of an in vitro cardiac cell model with higher throughput patch clamp screening technology allows for a cost-effective cardiotoxicity prediction in a physiologically relevant cell system.

A new seismic station in Romania the Bucovina seismic array

International Nuclear Information System (INIS)

Grigore, Adrian; Grecu, Bogdan; Ionescu, Constantin; Ghica, Daniela; Popa, Mihaela; Rizescu, Mihaela

2002-01-01

Recently, a new seismic monitoring station, the Bucovina Seismic Array, has been established in the northern part of Romania, in a joint effort of the Air Force Technical Applications Center, USA, and the National Institute for Earth Physics, Romania. The array consists of 10 seismic sensors (9 short-period and one broad band) located in boreholes and distributed in a 5 x 5 km area. On July 24, 2002 the official Opening Ceremony of Bucovina Seismic Array took place in the area near the city of Campulung Moldovenesc in the presence of Romanian Prime Minister, Adrian Nastase. Starting with this date, the new seismic monitoring system became fully operational by continuous recording and transmitting data in real-time to the National Data Center of Romania, in Bucharest and to the National Data Center of USA, in Florida. Bucovina Seismic Array, added to the present Seismic Network, will provide much better seismic monitoring coverage of Romania's territory, on-scale recording for weak-to-strong events, and will contribute to advanced seismological studies on seismic hazard and risk, local effects and microzonation, seismic source physics, Earth structure. (authors)

Flange joint system for SRF cavities utilizing high force spring clamps for low particle generation

Science.gov (United States)

None

2017-09-05

A flange joint system for SRF cavities. The flange joint system includes a set of high force spring clamps that produce high force on the simple flanges of Superconducting Radio Frequency (SRF) cavities to squeeze conventional metallic seals. The system establishes the required vacuum and RF-tight seal with minimum particle contamination to the inside of the cavity assembly. The spring clamps are designed to stay within their elastic range while being forced open enough to mount over the flange pair. Upon release, the clamps have enough force to plastically deform metallic seal surfaces and continue to a new equilibrium sprung dimension where the flanges remain held against one another with enough preload such that normal handling will not break the seal.

Down-Hole Heat Exchangers: Modelling of a Low-Enthalpy Geothermal System for District Heating

Directory of Open Access Journals (Sweden)

M. Carlini

2012-01-01

Full Text Available In order to face the growing energy demands, renewable energy sources can provide an alternative to fossil fuels. Thus, low-enthalpy geothermal plants may play a fundamental role in those areas—such as the Province of Viterbo—where shallow groundwater basins occur and conventional geothermal plants cannot be developed. This may lead to being fuelled by locally available sources. The aim of the present paper is to exploit the heat coming from a low-enthalpy geothermal system. The experimental plant consists in a down-hole heat exchanger for civil purposes and can supply thermal needs by district heating. An implementation in MATLAB environment is provided in order to develop a mathematical model. As a consequence, the amount of withdrawable heat can be successfully calculated.

Imaging Seismic Source Variations Using Back-Projection Methods at El Tatio Geyser Field, Northern Chile

Science.gov (United States)

Kelly, C. L.; Lawrence, J. F.

2014-12-01

During October 2012, 51 geophones and 6 broadband seismometers were deployed in an ~50x50m region surrounding a periodically erupting columnar geyser in the El Tatio Geyser Field, Chile. The dense array served as the seismic framework for a collaborative project to study the mechanics of complex hydrothermal systems. Contemporaneously, complementary geophysical measurements (including down-hole temperature and pressure, discharge rates, thermal imaging, water chemistry, and video) were also collected. Located on the western flanks of the Andes Mountains at an elevation of 4200m, El Tatio is the third largest geyser field in the world. Its non-pristine condition makes it an ideal location to perform minutely invasive geophysical studies. The El Jefe Geyser was chosen for its easily accessible conduit and extremely periodic eruption cycle (~120s). During approximately 2 weeks of continuous recording, we recorded ~2500 nighttime eruptions which lack cultural noise from tourism. With ample data, we aim to study how the source varies spatially and temporally during each phase of the geyser's eruption cycle. We are developing a new back-projection processing technique to improve source imaging for diffuse signals. Our method was previously applied to the Sierra Negra Volcano system, which also exhibits repeating harmonic and diffuse seismic sources. We back-project correlated seismic signals from the receivers back to their sources, assuming linear source to receiver paths and a known velocity model (obtained from ambient noise tomography). We apply polarization filters to isolate individual and concurrent geyser energy associated with P and S phases. We generate 4D, time-lapsed images of the geyser source field that illustrate how the source distribution changes through the eruption cycle. We compare images for pre-eruption, co-eruption, post-eruption and quiescent periods. We use our images to assess eruption mechanics in the system (i.e. top-down vs. bottom-up) and

The Seismic Analyzer: Interpreting and Illustrating 2D Seismic Data

OpenAIRE

Patel, Daniel; Giertsen, Christopher; Thurmond, John; Gjelberg, John; Gröller, Eduard

2008-01-01

We present a toolbox for quickly interpreting and illustrating 2D slices of seismic volumetric reflection data. Searching for oil and gas involves creating a structural overview of seismic reflection data to identify hydrocarbon reservoirs. We improve the search of seismic structures by precalculating the horizon structures of the seismic data prior to interpretation. We improve the annotation of seismic structures by applying novel illustrative rendering algorithms tailored to seism...

NIMBY, CLAMP, and the location of new nuclear-related facilities: U.S. national and 11 site-specific surveys.

Science.gov (United States)

Greenberg, Michael R

2009-09-01

Public and political opposition have made finding locations for new nuclear power plants, waste management, and nuclear research and development facilities a challenge for the U.S. government and the nuclear industry. U.S. government-owned properties that already have nuclear-related activities and commercial nuclear power generating stations are logical locations. Several studies and utility applications to the Nuclear Regulatory Commission suggest that concentrating locations at major plants (CLAMP) has become an implicit siting policy. We surveyed 2,101 people who lived within 50 miles of 11 existing major nuclear sites and 600 who lived elsewhere in the United States. Thirty-four percent favored CLAMP for new nuclear power plants, 52% for waste management facilities, and 50% for new nuclear laboratories. College educated, relatively affluent male whites were the strongest CLAMP supporters. They disproportionately trusted those responsible for the facilities and were not worried about existing nuclear facilities or other local environmental issues. Notably, they were concerned about continuing coal use. Not surprisingly, CLAMP proponents tended to be familiar with their existing local nuclear site. In short, likely CLAMP sites have a large and politically powerful core group to support a CLAMP policy. The challenge to proponents of nuclear technologies will be to sustain this support and expand the base among those who clearly are less connected and receptive to new nearby sites.

Comparison between symmetrical and asymmetrical single phase multilevel inverter with diode-clamped topology

DEFF Research Database (Denmark)

Blaabjerg, Frede; Nami, A.; Zare, F.

2008-01-01

In this paper, a different configuration based on different DC bus voltage for a diode-clamped multilevel inverter has been presented. Two different symmetrical and asymmetrical arrangements of a four-level diode clamped inverters have been compared, in order to find an optimum arrangement...... compared with the conventional four-level inverter and this will lead to the reduction of harmonic content of output voltage. A predictive current control technique has been carried out to verify the viability of new configuration. The advantages of this control method are simplicity and applicability...

Seismic damping factors of small bore piping as influenced by insulation and support elements

International Nuclear Information System (INIS)

Severud, L.K.; Anderson, M.J.; Barta, D.A.

1985-01-01

Seismic damping tests of a prototypical Liquid Metal Fast Breeder Reactor (LMFBR) small bore piping system is described, and measured transient responses to pulse excitations are reported. The test specimen was representative of a typical LMFBR insulated small bore piping system, and it was supported from a rigid test frame by prototypic dead weight supports, mechanical snubbers, and pipe clamps. Various support configurations were tested to assess the response sensitivity to insulation and other nonlinear support characteristics. Damping factors increased significantly due to the insulation and use of mechanical snubbers. Factors much higher than the magnitudes currently allowed in design by the USNRC Regulatory Guide 1.61, were found. This verified the design values, and it also pointed out the possibility of undue conservatism and costly overdesign resulting from use of the present design values

Seismic damping factors of small bore piping as influenced by insulation and support elements

International Nuclear Information System (INIS)

Severud, L.K.; Barta, D.A.

1983-01-01

Seismic damping tests of a prototypical Liquid Metal Fast Breeder Reactor (LMFBR) small bore piping system is described, and measured transient responses to pulse excitations are reported. The test specimen was representative of a typical LMFBR insulated small bore piping system, and it was supported from a rigid test frame by prototypic dead weight supports, mechanical snubbers, and pipe clamps. Various support configurations were tested to assess the response sensitivity to insulation and other nonlinear support characteristics. Damping factors increased significantly due to the insulation and use of mechanical snubbers. Factors much higher than the magnitudes currently allowed in design, by the USNRC Regulatory Guide 1.61, were found. This verified the design values but also pointed out the possibility of undue conservatism and costly overdesign resulting from use of the present design values

From deep water to deep rock: MWD/LWD technology advancing

Energy Technology Data Exchange (ETDEWEB)

Jaremko, D.

2004-01-01

Measurement-while-drilling (MWD) and logging-while-drilling (LWD) tools that help operators learn about the geological formations they drill while drilling them, are discussed. New MWD and LWD systems are quickly being developed for both offshore and onshore applications, even though both services are relatively expensive. For the offshore market a new seismic-while-drilling LWD tool has just been introduced by Schlumberger. The seismicVision tool acquires and transmits traditional borehole seismic data without interrupting drilling operations. Similarly, Baker-Atlas also introduced a new LWD system for onshore applications that uses advanced downhole sensing technology in a shorter, lighter, reliable instrument package to carry out well logging with accuracy and precision at up to twice the speed of conventional technology. Precision Drilling Inc. also has a new MWD system out, called HEL (hostile environment logging) which is designed to address shortcomings of currently available deepwater MWD systems. The HEL MWD is rated to operate at downhole pressures of up to 30,000 psi and temperatures of up to 180 degrees C. The entire system, including telemetry tools, environmental severity measurement sensors, and other sophisticated measuring tools are housed in one drill collar. photos.

Euglycemic clamp insulin sensitivity and longitudinal systolic blood pressure

DEFF Research Database (Denmark)

Petrie, John R; Malik, Muhammad Omar; Balkau, Beverley

2013-01-01

and Cardiovascular disease (RISC) study, we measured insulin sensitivity (M/I) using the euglycemic clamp technique in 1073 healthy European adults (587 women, 486 men) aged 30 to 60 years followed up 3 years later. Systolic BP (SBP) at baseline was higher in insulin-resistant women (ie, those in the low sex...

An accurate online calibration system based on combined clamp-shape coil for high voltage electronic current transformers

International Nuclear Information System (INIS)

Li, Zhen-hua; Li, Hong-bin; Zhang, Zhi

2013-01-01

Electronic transformers are widely used in power systems because of their wide bandwidth and good transient performance. However, as an emerging technology, the failure rate of electronic transformers is higher than that of traditional transformers. As a result, the calibration period needs to be shortened. Traditional calibration methods require the power of transmission line be cut off, which results in complicated operation and power off loss. This paper proposes an online calibration system which can calibrate electronic current transformers without power off. In this work, the high accuracy standard current transformer and online operation method are the key techniques. Based on the clamp-shape iron-core coil and clamp-shape air-core coil, a combined clamp-shape coil is designed as the standard current transformer. By analyzing the output characteristics of the two coils, the combined clamp-shape coil can achieve verification of the accuracy. So the accuracy of the online calibration system can be guaranteed. Moreover, by employing the earth potential working method and using two insulating rods to connect the combined clamp-shape coil to the high voltage bus, the operation becomes simple and safe. Tests in China National Center for High Voltage Measurement and field experiments show that the proposed system has a high accuracy of up to 0.05 class

An accurate online calibration system based on combined clamp-shape coil for high voltage electronic current transformers.

Science.gov (United States)

Li, Zhen-hua; Li, Hong-bin; Zhang, Zhi

2013-07-01

Electronic transformers are widely used in power systems because of their wide bandwidth and good transient performance. However, as an emerging technology, the failure rate of electronic transformers is higher than that of traditional transformers. As a result, the calibration period needs to be shortened. Traditional calibration methods require the power of transmission line be cut off, which results in complicated operation and power off loss. This paper proposes an online calibration system which can calibrate electronic current transformers without power off. In this work, the high accuracy standard current transformer and online operation method are the key techniques. Based on the clamp-shape iron-core coil and clamp-shape air-core coil, a combined clamp-shape coil is designed as the standard current transformer. By analyzing the output characteristics of the two coils, the combined clamp-shape coil can achieve verification of the accuracy. So the accuracy of the online calibration system can be guaranteed. Moreover, by employing the earth potential working method and using two insulating rods to connect the combined clamp-shape coil to the high voltage bus, the operation becomes simple and safe. Tests in China National Center for High Voltage Measurement and field experiments show that the proposed system has a high accuracy of up to 0.05 class.

Estimates for lower order eigenvalues of a clamped plate problem

OpenAIRE

Cheng, Qing-Ming; Huang, Guangyue; Wei, Guoxin

2009-01-01

For a bounded domain $\\Omega$ in a complete Riemannian manifold $M^n$, we study estimates for lower order eigenvalues of a clamped plate problem. We obtain universal inequalities for lower order eigenvalues. We would like to remark that our results are sharp.

A comparison of petrophysical data inputs for establishing time-depth relationships: a guide for future drilling expeditions

Science.gov (United States)

Boaga, J.; Sauermilch, I.; Mateo, Z. R. P.

2017-12-01

Time-depth relationships (TDR) are crucial in correlating drillhole and core information to seismic reflection profiles, for accurate resource estimation, scientific interpretation and to guide drilling operations. Conventional seismic time-depth domain conversion utilizes downhole sonic logs (DSI), calibrated using available checkshot data, which are local travel times from the surface to a particular depth. Scientific drilling programs (ODP and IODP) also measure P-wave velocity (PWL or C) on recovered core samples. Only three percent of all ODP and IODP sites record all three velocity measurements, however this information can be instructive as sometimes these data input show dissimilar TDR. These representative sites provide us with an opportunity to perform a comparative analysis highlighting the differences and similarities of TDRs derived from checkshot, downhole, and laboratory measurements. We then discuss the impact of lithology, stratigraphy, water column and other petrophysical properties in the predictive accuracy of TDR calculations, in an effort to provide guidance for future drilling and coring expeditions.

33 CFR 183.532 - Clips, straps, and hose clamps.

Science.gov (United States)

2010-07-01

... resistant material; and (2) Not cut or abrade the fuel line. (b) If tested in accordance with the fire test under § 183.590, a hose clamp installed on a fuel line system requiring metallic fuel lines or “USCG... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Equipment Standards § 183.532 Clips...

Seismic Microzonation for Refinement of Seismic Load Parameters

Energy Technology Data Exchange (ETDEWEB)

Savich, A. I.; Bugaevskii, A. G., E-mail: office@geodyn.ru, E-mail: bugaevskiy@geodyn.ru [Center of the Office of Geodynamic Observations in the Power Sector, an affiliate of JSC “Institut Gidroproekt” (Russian Federation)

2016-05-15

Functional dependencies are established for the characteristics of seismic transients recorded at various points of a studied site, which are used to propose a new approach to seismic microzonation (SMZ) that enables the creation of new SMZ maps of strong seismic motion, with due regard for dynamic parameters of recorded transients during weak earthquakes.

The seismic analyzer: interpreting and illustrating 2D seismic data.

Science.gov (United States)

Patel, Daniel; Giertsen, Christopher; Thurmond, John; Gjelberg, John; Gröller, M Eduard

2008-01-01

We present a toolbox for quickly interpreting and illustrating 2D slices of seismic volumetric reflection data. Searching for oil and gas involves creating a structural overview of seismic reflection data to identify hydrocarbon reservoirs. We improve the search of seismic structures by precalculating the horizon structures of the seismic data prior to interpretation. We improve the annotation of seismic structures by applying novel illustrative rendering algorithms tailored to seismic data, such as deformed texturing and line and texture transfer functions. The illustrative rendering results in multi-attribute and scale invariant visualizations where features are represented clearly in both highly zoomed in and zoomed out views. Thumbnail views in combination with interactive appearance control allows for a quick overview of the data before detailed interpretation takes place. These techniques help reduce the work of seismic illustrators and interpreters.

Seismicity and seismic monitoring in the Asse salt mine

International Nuclear Information System (INIS)

Flach, D.; Gommlich, G.; Hente, B.

1987-01-01

Seismicity analyses are made in order to assess the safety of candidate sites for ultimate disposal of hazardous wastes. The report in hand reviews the seismicity history of the Asse salt mine and presents recent results of a measuring campaign made in the area. The monitoring network installed at the site supplies data and information on the regional seismicity, on seismic amplitudes under ground and above ground, and on microseismic activities. (DG) [de

Role of clamping tube thoracostomy prior to removal in non-cardiac thoracic trauma

International Nuclear Information System (INIS)

Rasheed, M.A.; Majeed, F.A.; Naz, A.

2016-01-01

The frequently encountered thoracic trauma in surgical emergencies is a major cause of mortality and morbidity. Eighty percent of thoracic trauma can be managed by simple insertion of tube thoracostomy. Though guidelines for insertion are comprehensively explained in literature, an ideal algorithm for discontinuation is not available. A standard and safe defined protocol would eliminate hesitancy in confident removal among general surgeons. The objective of this study was to determine role of clamping trial prior to removal in terms of frequency of recurrent pneumothorax. Methods: This study was conducted in department of Surgery Combined military hospital/Military Hospital Rawalpindi from April 2013 to March 2014. Total 180 patients with blunt or penetrating thoracic trauma were included in the study. Chest tube (28-36 Fr) was inserted in Trauma centre under strict asepsis. Tubes were then connected to under water seal for minimum six hours. Patients were randomly divided in two equal groups (90 in each). In Group A, Clamping trial was given before attempting removal while in Group B, tube was removed immediately without clamping trial. Patients of both groups were observed two hourly for development of recurrent pneumothorax. Data was analysed using SPSS-18. Results: The comparison of frequency of recurrent pneumothorax in Group A (9 patients, 10%) and in Group B (4 patients, 4.5%) was not found to be statistically significant. (p-value 2.073). Conclusion: Clamping trial is unnecessary prior to removal of tube thoracostomy in blunt and penetrating non-cardiac thoracic trauma in terms of recurrent pneumothorax. (author)

Mycobacterium tuberculosis class II apurinic/apyrimidinic-endonuclease/3'-5' exonuclease III exhibits DNA regulated modes of interaction with the sliding DNA β-clamp.

Science.gov (United States)

Khanam, Taran; Rai, Niyati; Ramachandran, Ravishankar

2015-10-01

The class-II AP-endonuclease (XthA) acts on abasic sites of damaged DNA in bacterial base excision repair. We identified that the sliding DNA β-clamp forms in vivo and in vitro complexes with XthA in Mycobacterium tuberculosis. A novel 239 QLRFPKK245 motif in the DNA-binding domain of XthA was found to be important for the interactions. Likewise, the peptide binding-groove (PBG) and the C-terminal of β-clamp located on different domains interact with XthA. The β-clamp-XthA complex can be disrupted by clamp binding peptides and also by a specific bacterial clamp inhibitor that binds at the PBG. We also identified that β-clamp stimulates the activities of XthA primarily by increasing its affinity for the substrate and its processivity. Additionally, loading of the β-clamp onto DNA is required for activity stimulation. A reduction in XthA activity stimulation was observed in the presence of β-clamp binding peptides supporting that direct interactions between the proteins are necessary to cause stimulation. Finally, we found that in the absence of DNA, the PBG located on the second domain of the β-clamp is important for interactions with XthA, while the C-terminal domain predominantly mediates functional interactions in the substrate's presence. © 2015 John Wiley & Sons Ltd.

The Effect of PRGF on Healing of Clamp-Induced Tendinopathy in Animals

Directory of Open Access Journals (Sweden)

Uğur Diliçıkık

2018-04-01

Material and Methods: A preliminary study was designed to obtain more apparent tendinopathy changes in the subculture. Histopathologically, second level compression with a clamp for 1 minute followed by releasing for 3 minutes applying the same mechanical stimulus procedure for four times, was defined as the optimal compression mode for the most optimal damage in terms of tendinopathy. Thirty-four female Sprague Downey type rats were divided into five separate groups and clamped tendon damage was formed on unilateral (left Acchilles tendons. The first group was a control group (Kontrol: CN; in the second group tissue specimens were taken from the rats immediately after being clamped (K-0; from the group 3, tissue samples were taken 1 week after clamping (K-7. Immediately after the tendinopathy model was applied to the animals in the fourth group (PRGF, the PRGF injection was performed to the subjects from the blood that was obtained from the control group, while an isotonic saline solution was injected into the subjects in the fifth group (SF, and tissue samples from both groups were obtained 1 week after. Results: The samples were examined by means of a transmission electron microscope. In the K-0 group among the collagenous fibers, vacuoles are observed in the cytoplasm of the edematous areas and fibrocytes, and in comparison, with K-7 and SF group there was a significant increase in fibroblast and collagen fiber synthesis in the PRGF-treated group. Furthermore, fibroblast and new collagen synthesis were observed to be increased in K-7 and SF groups. An intense increase in organelle levels was observed in PRGF group fibroblasts. Conclusion: This data suggests that PRGF may provide a better healing response in tendons with limited healing and circulation, which enhances the activation in the cells at the beginning of the healing process.

German seismic regulations

International Nuclear Information System (INIS)

Danisch, Ruediger

2002-01-01

Rules and regulations for seismic design in Germany cover the following: seismic design of conventional buildings; and seismic design of nuclear facilities. Safety criteria for NPPs, accident guidelines, and guidelines for PWRs as well as safety standards are cited. Safety standards concerned with NPPs seismic design include basic principles, soil analysis, design of building structures, design of mechanical and electrical components, seismic instrumentation, and measures to be undertaken after the earthquake

Establishing seismic design criteria to achieve an acceptable seismic margin

International Nuclear Information System (INIS)

Kennedy, R.P.

1997-01-01

In order to develop a risk based seismic design criteria the following four issues must be addressed: (1) What target annual probability of seismic induced unacceptable performance is acceptable? (2). What minimum seismic margin is acceptable? (3) Given the decisions made under Issues 1 and 2, at what annual frequency of exceedance should the Safe Shutdown Earthquake ground motion be defined? (4) What seismic design criteria should be established to reasonably achieve the seismic margin defined under Issue 2? The first issue is purely a policy decision and is not addressed in this paper. Each of the other three issues are addressed. Issues 2 and 3 are integrally tied together so that a very large number of possible combinations of responses to these two issues can be used to achieve the target goal defined under Issue 1. Section 2 lays out a combined approach to these two issues and presents three potentially attractive combined resolutions of these two issues which reasonably achieves the target goal. The remainder of the paper discusses an approach which can be used to develop seismic design criteria aimed at achieving the desired seismic margin defined in resolution of Issue 2. Suggestions for revising existing seismic design criteria to more consistently achieve the desired seismic margin are presented

Seismic capacity of a reinforced concrete frame structure without seismic detailing and limited ductility seismic design in moderate seismicity

International Nuclear Information System (INIS)

Kim, J. K.; Kim, I. H.

1999-01-01

A four-story reinforced concrete frame building model is designed for the gravity loads only. Static nonlinear pushover analyses are performed in two orthogonal horizontal directions. The overall capacity curves are converted into ADRS spectra and compared with demand spectra. At several points the deformed shape, moment and shear distribution are calculated. Based on these results limited ductility seismic design concept is proposed as an alternative seismic design approach in moderate seismicity resign

Outside-out "sniffer-patch" clamp technique for in situ measures of neurotransmitter release.

Science.gov (United States)

Muller-Chrétien, Emilie

2014-01-01

The mechanism underlying neurotransmitter release is a critical research domain for the understanding of neuronal network function; however, few techniques are available for the direct detection and measurement of neurotransmitter release. To date, the sniffer-patch clamp technique is mainly used to investigate these mechanisms from individual cultured cells. In this study, we propose to adapt the sniffer-patch clamp technique to in situ detection of neurosecretion. Using outside-out patches from donor cells as specific biosensors plunged in acute cerebral slices, this technique allows for proper detection and quantification of neurotransmitter release at the level of the neuronal network.

Scanning electron microscope/energy dispersive x ray analysis of impact residues on LDEF tray clamps

Science.gov (United States)

Bernhard, Ronald P.; Durin, Christian; Zolensky, Michael E.

1992-01-01

To better understand the nature of particulates in low-Earth orbit (LEO), and their effects on spacecraft hardware, we are analyzing residues found in impacts on the Long Duration Exposure Facility (LDEF) tray clamps. LDEF experiment trays were held in place by 6 to 8 chromic-anodized aluminum (6061-T6) clamps that were fastened to the spacecraft frame using three stainless steel hex bolts. Each clamp exposed an area of approximately 58 sq cm (4.8 cm x 12.7 cm x .45 cm, minus the bolt coverage). Some 337 out of 774 LDEF tray clamps were archived at JSC and are available through the Meteoroid & Debris Special Investigation Group (M&D SIG). Optical scanning of clamps, starting with Bay/Row A01 and working toward H25, is being conducted at JSC to locate and document impacts as small as 40 microns. These impacts are then inspected by Scanning Electron Microscopy/Energy Dispersive X-ray Analysis (SEM/EDXA) to select those features which contain appreciable impact residue material. Based upon the composition of projectile remnants, and using criteria developed at JSC, we have made a preliminary discrimination between micrometeoroid and space debris residue-containing impact features. Presently, 13 impacts containing significant amounts of unmelted and semi-melted micrometeoritic residues were forwarded to Centre National d'Etudes Spatiales (CNES) in France. At the CNES facilities, the upgraded impacts were analyzed using a JEOL T330A SEM equipped with a NORAN Instruments, Voyager X-ray Analyzer. All residues were quantitatively characterized by composition (including oxygen and carbon) to help understand interplanetary dust as possibly being derived from comets and asteroids.

Burar seismic station: evaluation of seismic performance

International Nuclear Information System (INIS)

Ghica, Daniela; Popa, Mihaela

2005-01-01

A new seismic monitoring system, the Bucovina Seismic Array (BURAR), has been established since July 2002, in the Northern part of Romania, in a joint effort of the Air Force Technical Applications Center, USA, and the National Institute for Earth Physics (NIEP), Romania. The small-aperture array consists of 10 seismic sensors (9 vertical short-period and one three-component broad band) located in boreholes and distributed in a 5 x 5 km 2 area. At present, the seismic data are continuously recorded by the BURAR and transmitted in real-time to the Romanian National Data Center in Bucharest and National Data Center of the USA, in Florida. Based on the BURAR seismic information gathered at the National Data Center, NIEP (ROM N DC), in the August 2002 - December 2004 time interval, analysis and statistical assessments were performed. Following the preliminary processing of the data, several observations on the global performance of the BURAR system were emphasized. Data investigation showed an excellent efficiency of the BURAR system particularly in detecting teleseismic and regional events. Also, a statistical analysis for the BURAR detection capability of the local Vrancea events was performed in terms of depth and magnitude for the year 2004. The high signal detection capability of the BURAR resulted, generally, in improving the location solutions for the Vrancea seismic events. The location solution accuracy is enhanced when adding BURAR recordings, especially in the case of low magnitude events (recorded by few stations). The location accuracy is increased, both in terms of constraining hypocenter depth and epicentral coordinates. Our analysis certifies the importance of the BURAR system in NIEP efforts to elaborate seismic bulletins. Furthermore, the specific procedures for array data processing (beam forming, f-k analysis) increase significantly the signal-to-noise ratio by summing up the coherent signals from the array components, and ensure a better accuracy

Biological cell controllable patch-clamp microchip

Science.gov (United States)

Penmetsa, Siva; Nagrajan, Krithika; Gong, Zhongcheng; Mills, David; Que, Long

2010-12-01

A patch-clamp (PC) microchip with cell sorting and positioning functions is reported, which can avoid drawbacks of random cell selection or positioning for a PC microchip. The cell sorting and positioning are enabled by air bubble (AB) actuators. AB actuators are pneumatic actuators, in which air pressure is generated by microheaters within sealed microchambers. The sorting, positioning, and capturing of 3T3 cells by this type of microchip have been demonstrated. Using human breast cancer cells MDA-MB-231 as the model, experiments have been demonstrated by this microchip as a label-free technical platform for real-time monitoring of the cell viability.

Seismic hazard estimation based on the distributed seismicity in northern China

Science.gov (United States)

Yang, Yong; Shi, Bao-Ping; Sun, Liang

2008-03-01

In this paper, we have proposed an alternative seismic hazard modeling by using distributed seismicites. The distributed seismicity model does not need delineation of seismic source zones, and simplify the methodology of probabilistic seismic hazard analysis. Based on the devastating earthquake catalogue, we established three seismicity model, derived the distribution of a-value in northern China by using Gaussian smoothing function, and calculated peak ground acceleration distributions for this area with 2%, 5% and 10% probability of exceedance in a 50-year period by using three attenuation models, respectively. In general, the peak ground motion distribution patterns are consistent with current seismic hazard map of China, but in some specific seismic zones which include Shanxi Province and Shijiazhuang areas, our results indicated a little bit higher peak ground motions and zonation characters which are in agreement with seismicity distribution patterns in these areas. The hazard curves have been developed for Beijing, Tianjin, Taiyuan, Tangshan, and Ji’nan, the metropolitan cities in the northern China. The results showed that Tangshan, Taiyuan, Beijing has a higher seismic hazard than that of other cities mentioned above.

Analysis of failed and nickel-coated 3093 beam clamp components at the East Tennessee Technology Park (ETTP).

Energy Technology Data Exchange (ETDEWEB)

Singh, D.; Pappacena, K.; Gaviria, J.; Burtsteva, T.; Nuclear Engineering Division

2010-10-11

The U.S. Department of Energy and its contractor, Bechtel Jacobs Company (BJC), are undertaking a major effort to clean up the former gaseous diffusion facility (K-25) located in Oak Ridge, TN. The decontamination and decommissioning activities require systematic removal of contaminated equipment and machinery followed by demolition of the buildings. As part of the cleanup activities, a beam clamp, used for horizontal life lines (HLLs) for fall protection, was discovered to be fractured during routine inspection. The beam clamp (yoke and D-ring) was a component in the HLL system purchased from Reliance Industries LLC. Specifically, the U-shaped stainless steel yoke of the beam clamp failed in a brittle mode at under less than 10% of the rated design capacity of 14,500 lb. The beam clamp had been in service for approximately 16 months. Bechtel Jacobs approached Argonne National Laboratory to assist in identifying the root cause of the failure of the beam clamp. The objectives of this study were to (1) review the prior reports and documents on the subject, (2) understand the possible failure mechanism(s) that resulted in the failed beam clamp components, (3) recommend approaches to mitigate the failure mechanism(s), and (4) evaluate the modified beam clamp assemblies. Energy dispersive x-ray analysis and chemical analysis of the corrosion products on the failed yoke and white residue on an in-service yoke indicated the presence of zinc, sulfur, and calcium. Analysis of rainwater in the complex, as conducted by BJC, indicated the presence of sulfur and calcium. It was concluded that, as a result of galvanic corrosion, zinc from the galvanized components of the beam clamp assembly (D-ring) migrated to the corroded region in the presence of the rainwater. Under mechanical stress, the corrosion process would have accelerated, resulting in the catastrophic failure of the yoke. As suggested by Bechtel Jacobs personnel, hydrogen embrittlement as a consequence of corrosion

Progressive Seismic Failure, Seismic Gap, and Great Seismic Risk across the Densely Populated North China Basin

Science.gov (United States)

Yin, A.; Yu, X.; Shen, Z.

2014-12-01

Although the seismically active North China basin has the most complete written records of pre-instrumentation earthquakes in the world, this information has not been fully utilized for assessing potential earthquake hazards of this densely populated region that hosts ~200 million people. In this study, we use the historical records to document the earthquake migration pattern and the existence of a 180-km seismic gap along the 600-km long right-slip Tangshan-Hejian-Cixian (THC) fault zone that cuts across the North China basin. The newly recognized seismic gap, which is centered at Tianjin with a population of 11 million people and ~120 km from Beijing (22 million people) and Tangshan (7 million people), has not been ruptured in the past 1000 years by M≥6 earthquakes. The seismic migration pattern in the past millennium suggests that the epicenters of major earthquakes have shifted towards this seismic gap along the THC fault, which implies that the 180- km gap could be the site of the next great earthquake with M≈7.6 if it is ruptured by a single event. Alternatively, the seismic gap may be explained by aseismic creeping or seismic strain transfer between active faults.

Time-Independent Annual Seismic Rates, Based on Faults and Smoothed Seismicity, Computed for Seismic Hazard Assessment in Italy

Science.gov (United States)

Murru, M.; Falcone, G.; Taroni, M.; Console, R.

2017-12-01

In 2015 the Italian Department of Civil Protection, started a project for upgrading the official Italian seismic hazard map (MPS04) inviting the Italian scientific community to participate in a joint effort for its realization. We participated providing spatially variable time-independent (Poisson) long-term annual occurrence rates of seismic events on the entire Italian territory, considering cells of 0.1°x0.1° from M4.5 up to M8.1 for magnitude bin of 0.1 units. Our final model was composed by two different models, merged in one ensemble model, each one with the same weight: the first one was realized by a smoothed seismicity approach, the second one using the seismogenic faults. The spatial smoothed seismicity was obtained using the smoothing method introduced by Frankel (1995) applied to the historical and instrumental seismicity. In this approach we adopted a tapered Gutenberg-Richter relation with a b-value fixed to 1 and a corner magnitude estimated with the bigger events in the catalogs. For each seismogenic fault provided by the Database of the Individual Seismogenic Sources (DISS), we computed the annual rate (for each cells of 0.1°x0.1°) for magnitude bin of 0.1 units, assuming that the seismic moments of the earthquakes generated by each fault are distributed according to the same tapered Gutenberg-Richter relation of the smoothed seismicity model. The annual rate for the final model was determined in the following way: if the cell falls within one of the seismic sources, we merge the respective value of rate determined by the seismic moments of the earthquakes generated by each fault and the value of the smoothed seismicity model with the same weight; if instead the cells fall outside of any seismic source we considered the rate obtained from the spatial smoothed seismicity. Here we present the final results of our study to be used for the new Italian seismic hazard map.

space vector pulse width modulation of a multi-level diode clamped

African Journals Online (AJOL)

ES Obe

step by step development of MATLAB /SIMULINK modeling of the space vector ..... Pulse Width Mod. of Multi-Level Diode Clamped Converter 119 powergui. Discrete, .... Load. Figure 22: Block diagram of the three level DCC design. 3 LEVEL ...

Voltage Balancing Control of Diode-Clamped Multilevel Inverter

Directory of Open Access Journals (Sweden)

ŞCHIOP Adrian

2013-10-01

Full Text Available In this paper is developed a control scheme for mono-phase diode clamped inverter to achieve balancing voltages on inverter capacitors. First, it develops a control scheme without taking into account the need to balance voltage on two capacitors. It examines the effects on the output voltage inverter, and then it realizes two control schemes that will balance the voltages. The simulations of control schemes were performed in OrCAD Pspice.

Five-level Z-source diode-clamped inverter

DEFF Research Database (Denmark)

Gao, F.; Loh, Poh Chiang; Blaabjerg, Frede

2010-01-01

This study proposes a five-level Z-source diode-clamped inverter designed with two intermediate Z-source networks connected between the dc input sources and rear-end inverter circuitry. By partially shorting the Z-source networks, new operating states not previously reported for two-level Z......-source inverter are introduced here for operating the proposed inverter with voltage buck–boost energy conversion ability and five-level phase voltage switching. These characteristic features are in fact always ensured at the inverter terminal output by simply adopting a properly designed carrier modulation...

Bingham Sealing and Application in Vacuum Clamping

Science.gov (United States)

Yao, S. M.; Teo, Wee Kin; Geng, Zunmin; Turner, Sam; Ridgway, Keith

2011-12-01

Vacuum clamping is extensively used in shell machining. In this paper a Bingham Sealing (BS) is presented and formulized based on Bingham plastic performance. The sealing capability of BS is evaluated in various cases. A new Bingham plastic is developed and the yield stress is measured. The performances of "O"ring sealing and BS with the developed Bingham plastic are compared to the static experiment. In this experiment the same vacuum is achieved and the distortion of the blade with BS is better than that with "O" ring sealing.

Bingham Sealing and Application in Vacuum Clamping

International Nuclear Information System (INIS)

Yao, S M; Teo, Wee Kin; Geng Zunmin; Turner, Sam; Ridgway, Keith

2011-01-01

Vacuum clamping is extensively used in shell machining. In this paper a Bingham Sealing (BS) is presented and formulized based on Bingham plastic performance. The sealing capability of BS is evaluated in various cases. A new Bingham plastic is developed and the yield stress is measured. The performances of Or ing sealing and BS with the developed Bingham plastic are compared to the static experiment. In this experiment the same vacuum is achieved and the distortion of the blade with BS is better than that with 'O' ring sealing.

The hypertriglyceridemic clamp technique. Studies using long-chain and structured triglyceride emulsions in healthy subjects.

Science.gov (United States)

Nordenström, Jörgen; Thörne, Anders; Aberg, Wiveca; Carneheim, Claes; Olivecrona, Thomas

2006-11-01

In a randomized crossover study, plasma kinetics of 2 different types of fat emulsions were studied in 8 healthy volunteers by using a hypertriglyceridemic clamp technique. The method involves the stabilization of serum triglyceride (TG) concentration during 180 minutes at a predetermined level (4 mmol/L) by adjustment of TG infusion rate by repeated online measurements of serum TG concentration. The fat emulsions under study were a long-chain fatty acid triglyceride (LCT) emulsion (Intralipid 20%, Fresenius Kabi, Sweden) and a structured triglyceride (STG) emulsion (Structolipid 20%, Fresenius Kabi) where medium- and long-chain fatty acids have been interesterified within a TG molecule. The hypertriglyceridemic clamp was found to have acceptable reproducibility when tested in 3 healthy individuals on 2 different occasions, as similar steady-state TG levels were obtained by infusing similar amounts of fat. The average (+/-SEM) TG concentration during the 180-minute clamp was similar for STGs and LCTs (4.0 +/- 0.1 vs 3.9 +/- 0.1 mmol/L; not significant), but the amount of fat that had to be infused was significantly higher during STG than during LCT clamping (0.31 +/- 0.04 vs 0.21 +/- 0.02 g TG per minute; P < .05). Higher serum levels of free fatty acids (1.80 +/- 0.13 vs 0.96 +/- 0.09 mmol/L; P < .05), free glycerol (1.30 +/- 0.07 vs 0.76 +/- 0.08 mmol/L; P < .001), and beta-OH butyrate (1.61 +/- 0.44 vs 1.17 +/- 0.23 mmol/L; not significant) were obtained at the end of the clamp during infusion of STGs compared with LCTs. During infusion of STGs the medium-chain fatty acids octanoic (C:8) and decanoic acid (C:10) constituted approximately half of circulating fatty acids that correspond to the compositional ratio of the emulsion. Plasma lipoprotein lipase (LPL) concentration was higher during STG than during LCT clamping (6.06 +/- 0.62 vs 3.15 +/- 0.40 mU/mL; P < .05), and there was a positive correlation between the mean LPL concentration and the amount of

Simple hardware implementation of voltage balancing in capacitor-clamped inverter

Czech Academy of Sciences Publication Activity Database

Kokeš, Petr; Semerád, Radko

2009-01-01

Roč. 54, č. 4 (2009), s. 325-341 ISSN 0001-7043 R&D Projects: GA MPO FT-TA4/077 Institutional research plan: CEZ:AV0Z20570509 Keywords : capacitor -clamped multilevel inverter * flying capacitor voltage balancing * pulse width modulation (PWM) Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

Production of natural gas from methane hydrate by a constant downhole pressure well

International Nuclear Information System (INIS)

Ahmadi, Goodarz; Ji, Chuang; Smith, Duane H.

2007-01-01

Natural gas production from the dissociation of methane hydrate in a confined reservoir by a depressurizing downhole well was studied. The case that the well pressure was kept constant was treated, and two different linearization schemes in an axisymmetric configuration were used in the analysis. For different fixed well pressures and reservoir temperatures, approximate self similar solutions were obtained. Distributions of temperature, pressure and gas velocity field across the reservoir were evaluated. The distance of the decomposition front from the well and the natural gas production rate as functions of time were also computed. Time evolutions of the resulting profiles were presented in graphical forms, and their differences with the constant well output results were studied. It was shown that the gas production rate was a sensitive function of well pressure and reservoir temperature. The sensitivity of the results to the linearization scheme used was also studied

Delineation of seismic source zones based on seismicity parameters ...

Indian Academy of Sciences (India)

In the present study, an attempt has been made to delineate seismic source zones in the study area (south India) based on the seismicity parameters. Seismicity parameters and the maximum probable earthquake for these source zones were evaluated and were used in the hazard evaluation. The probabilistic evaluation of ...

Russian regulatory approaches to seismic design and seismic analysis of NPP piping

International Nuclear Information System (INIS)

Kaliberda, Y.V.

2003-01-01

The paper presents an overview of Russian regulatory approaches to seismic design and seismic analysis of NPP piping. The paper is focused on categorization and seismic analysis of nuclear power plant items (piping, equipment, supports, valves, but not building structures). The paper outlines the current seismic recommendations, corresponding methods with the examples of calculation models. The paper considers calculation results of the mechanisms of dynamic behavior and the problems of developing a rational and economical approaches to seismic design and seismic protection. (author)

Angola Seismicity MAP

Science.gov (United States)

Neto, F. A. P.; Franca, G.

2014-12-01

The purpose of this job was to study and document the Angola natural seismicity, establishment of the first database seismic data to facilitate consultation and search for information on seismic activity in the country. The study was conducted based on query reports produced by National Institute of Meteorology and Geophysics (INAMET) 1968 to 2014 with emphasis to the work presented by Moreira (1968), that defined six seismogenic zones from macro seismic data, with highlighting is Zone of Sá da Bandeira (Lubango)-Chibemba-Oncócua-Iona. This is the most important of Angola seismic zone, covering the epicentral Quihita and Iona regions, geologically characterized by transcontinental structure tectono-magmatic activation of the Mesozoic with the installation of a wide variety of intrusive rocks of ultrabasic-alkaline composition, basic and alkaline, kimberlites and carbonatites, strongly marked by intense tectonism, presenting with several faults and fractures (locally called corredor de Lucapa). The earthquake of May 9, 1948 reached intensity VI on the Mercalli-Sieberg scale (MCS) in the locality of Quihita, and seismic active of Iona January 15, 1964, the main shock hit the grade VI-VII. Although not having significant seismicity rate can not be neglected, the other five zone are: Cassongue-Ganda-Massano de Amorim; Lola-Quilengues-Caluquembe; Gago Coutinho-zone; Cuima-Cachingues-Cambândua; The Upper Zambezi zone. We also analyzed technical reports on the seismicity of the middle Kwanza produced by Hidroproekt (GAMEK) region as well as international seismic bulletins of the International Seismological Centre (ISC), United States Geological Survey (USGS), and these data served for instrumental location of the epicenters. All compiled information made possible the creation of the First datbase of seismic data for Angola, preparing the map of seismicity with the reconfirmation of the main seismic zones defined by Moreira (1968) and the identification of a new seismic

France's seismic zoning

International Nuclear Information System (INIS)

Mohammadioun, B.

1997-01-01

In order to assess the seismic hazard in France in relation to nuclear plant siting, the CEA, EDF and the BRGM (Mine and Geology Bureau) have carried out a collaboration which resulted in a seismic-tectonic map of France and a data base on seismic history (SIRENE). These studies were completed with a seismic-tectonic zoning, taking into account a very long period of time, that enabled a probabilistic evaluation of the seismic hazard in France, and that may be related to adjacent country hazard maps

Effects of clamping force on the water transport and performance of a PEM (proton electrolyte membrane) fuel cell with relative humidity and current density

International Nuclear Information System (INIS)

Cha, Dowon; Ahn, Jae Hwan; Kim, Hyung Soon; Kim, Yongchan

2015-01-01

The clamping force should be applied to a proton electrolyte membrane (PEM) fuel cell due to its structural characteristics. The clamping force affects the ohmic and mass transport resistances in the PEM fuel cell. In this study, the effects of the clamping force on the water transport and performance characteristics of a PEM fuel cell are experimentally investigated with variations in the relative humidity and current density. The water transport characteristics were analyzed by calculating the net drag coefficient. The ohmic resistance decreased with the increase in the clamping force due to the reduced contact resistance and more even membrane hydration. However, the mass transport resistance increased with the increase in the clamping force due to the gas diffusion layer compression. The net drag coefficient decreased with the increase in the clamping force due to high water back-diffusion. Additionally, the relationship between the total resistance and the net drag coefficient was investigated. - Highlights: • Effects of clamping force on the performance of a PEM fuel cell are investigated. • Water transport characteristics are analyzed using net drag coefficient. • Ohmic resistance decreased with clamping force, but mass transport resistance increased. • Net drag coefficient decreased with the increase in clamping force. • Total resistance was significantly degraded for a net drag coefficient below 0.2.

Stress sensitivity of fault seismicity: A comparison between limited-offset oblique and major strike-slip faults

Science.gov (United States)

Parsons, T.; Stein, R.S.; Simpson, R.W.; Reasenberg, P.A.

1999-01-01

We present a new three-dimensional inventory of the southern San Francisco Bay area faults and use it to calculate stress applied principally by the 1989 M = 7.1 Loma Prieta earthquake and to compare fault seismicity rates before and after 1989. The major high-angle right-lateral faults exhibit a different response to the stress change than do minor oblique (right-lateral/thrust) faults. Seismicity on oblique-slip faults in the southern Santa Clara Valley thrust belt increased where the faults were unclamped. The strong dependence of seismicity change on normal stress change implies a high coefficient of static friction. In contrast, we observe that faults with significant offset (>50-100 km) behave differently; microseismicity on the Hayward fault diminished where right-lateral shear stress was reduced and where it was unclamped by the Loma Prieta earthquake. We observe a similar response on the San Andreas fault zone in southern California after the Landers earthquake sequence. Additionally, the offshore San Gregorio fault shows a seismicity rate increase where right-lateral/oblique shear stress was increased by the Loma Prieta earthquake despite also being clamped by it. These responses are consistent with either a low coefficient of static friction or high pore fluid pressures within the fault zones. We can explain the different behavior of the two styles of faults if those with large cumulative offset become impermeable through gouge buildup; coseismically pressurized pore fluids could be trapped and negate imposed normal stress changes, whereas in more limited offset faults, fluids could rapidly escape. The difference in behavior between minor and major faults may explain why frictional failure criteria that apply intermediate coefficients of static friction can be effective in describing the broad distributions of aftershocks that follow large earthquakes, since many of these events occur both inside and outside major fault zones.

Seismic Noise Analysis and Reduction through Utilization of Collocated Seismic and Atmospheric Sensors at the GRO Chile Seismic Network

Science.gov (United States)

Farrell, M. E.; Russo, R. M.

2013-12-01

The installation of Earthscope Transportable Array-style geophysical observatories in Chile expands open data seismic recording capabilities in the southern hemisphere by nearly 30%, and has nearly tripled the number of seismic stations providing freely-available data in southern South America. Through the use of collocated seismic and atmospheric sensors at these stations we are able to analyze how local atmospheric conditions generate seismic noise, which can degrade data in seismic frequency bands at stations in the ';roaring forties' (S latitudes). Seismic vaults that are climate-controlled and insulated from the local environment are now employed throughout the world in an attempt to isolate seismometers from as many noise sources as possible. However, this is an expensive solution that is neither practical nor possible for all seismic deployments; and also, the increasing number and scope of temporary seismic deployments has resulted in the collection and archiving of terabytes of seismic data that is affected to some degree by natural seismic noise sources such as wind and atmospheric pressure changes. Changing air pressure can result in a depression and subsequent rebound of Earth's surface - which generates low frequency noise in seismic frequency bands - and even moderate winds can apply enough force to ground-coupled structures or to the surface above the seismometers themselves, resulting in significant noise. The 10 stations of the permanent Geophysical Reporting Observatories (GRO Chile), jointly installed during 2011-12 by IRIS and the Chilean Servicio Sismológico, include instrumentation in addition to the standard three seismic components. These stations, spaced approximately 300 km apart along the length of the country, continuously record a variety of atmospheric data including infrasound, air pressure, wind speed, and wind direction. The collocated seismic and atmospheric sensors at each station allow us to analyze both datasets together, to

External mean flow influence on sound transmission through finite clamped double-wall sandwich panels

Science.gov (United States)

Liu, Yu; Catalan, Jean-Cédric

2017-09-01

This paper studies the influence of an external mean flow on the sound transmission through finite clamped double-wall sandwich panels lined with poroelastic materials. Biot's theory is employed to describe wave propagation in poroelastic materials and various configurations of coupling the poroelastic layer to the facing plates are considered. The clamped boundary of finite panels are dealt with by the modal superposition theory and the weighted residual (Garlekin) method, leading to a matrix equation solution for the sound transmission loss (STL) through the structure. The theoretical model is validated against existing theories of infinite sandwich panels with and without an external flow. The numerical results of a single incident wave show that the external mean flow has significant effects on the STL which are coupled with the clamped boundary effect dominating in the low-frequency range. The external mean flow also influences considerably the limiting incidence angle of the panel system and the effect of the incidence angle on the STL. However, the influences of the azimuthal angle and the external flow orientation are negligible.

Isolated PWM DC-AC SICAM with an active capacitive voltage clamp[Pulse Density Modulated; Pulse Width Modulation

Energy Technology Data Exchange (ETDEWEB)

Ljusev, P.

2004-03-15

In this report an isolated PWM DC-AC SICAM with an active capacitive voltage clamp is presented. AC-DC power supply is implemented in its simplest form: diode rectifier followed by a medium-size charge-storage capacitors and possibly with an EMC filter on the mains entrance. Isolation from the AC mains is achieved using a high frequency (HF) transformer, whose voltages are not audio-modulated. The latter simplifies the design and is expected to have many advantages over the approach where the transformer voltages are modulated in regards to the audio signal reference. Input stage is built as a DC-AC inverter (push-pull, half-bridge or a full-bridge) and operated with 50% duty cycle, with all the challenges to avoid transformer saturation and obtain symmetrical operation. On the secondary side the output section is implemented as rectifier+inverter AC-AC stage, i.e. a true bidirectional bridge, which operation is aimed towards amplification of the audio signal. In order to solve the problem with the commutation of the load current, a dead time between the incoming and outgoing bidirectional switch is implemented, while a capacitive voltage clamp is used to keep the induced overvoltage to reasonable levels. The energy stored in the clamping capacitor is not wasted as in the dissipative clamps, but is rather transferred back to the primary side for further processing using an auxiliary isolated single-switch converter, i.e. an active clamping technique is used. (au)

Seismic re-evaluation of Mochovce nuclear power plant. Seismic reevaluation of civil structures

International Nuclear Information System (INIS)

Podrouzek, P.

1997-01-01

In this contribution, an overview of seismic design procedures used for reassessment of seismic safety of civil structures at the Mochovce NPP in Slovak Republic presented. As an introduction, the objectives, history, and current status of seismic design of the NPP have been explained. General philosophy of design methods, seismic classification of buildings, seismic data, calculation methods, assumptions on structural behavior under seismic loading and reliability assessment were described in detail in the subsequent section. Examples of calculation models used for dynamic calculations of seismic response are given in the last section. (author)

Downhole Elemental Analysis with LIBS

Science.gov (United States)

Moreschini, Paolo; Zacny, Kris; Rickman, Doug

2011-01-01

vertical stage; a second actuator at the top of the downhole probe allows radial scanning of the borehole. Analysis of iron and titanium in lunar simulant with LIBS was performed in air using the method of standard addition. The results for lunar simulant NU-LHT-2M show a value for the concentration of iron ranging between 2.29% and 3.05% depending on the atomic line selected. The accepted value for the sample analyzed is 2.83%, showing the capability for the system in development to provide qualitative and semi-quantitative analysis in real-time.

Role of seismic PRA in seismic safety decisions of nuclear power plants

International Nuclear Information System (INIS)

Ravindra, M.K.; Kennedy, R.P.; Sues, R.H.

1985-01-01

This paper highlights the important roles that seismic probabilistic risk assessments (PRAs) can play in the seismic safety decisions of nuclear power plants. If a seismic PRA has been performed for a plant, its results can be utilized to evaluate the seismic capability beyond the safe shutdown event (SSE). Seismic fragilities of key structures and equipment, fragilities of dominant plant damage states and the frequencies of occurrence of these plant damage states are reviewed to establish the seismic safety of the plant beyond the SSE level. Guidelines for seismic margin reviews and upgrading may be developed by first identifying the generic classes of structures and equipment that have been shown to be dominant risk contributors in the completed seismic PRAs, studying the underlying causes for their contribution and examining why certain other items (e.g., piping) have not proved to be high-risk-contributors

Analytical and experimental investigation on transmission loss of clamped double panels: implication of boundary effects.

Science.gov (United States)

Xin, F X; Lu, T J

2009-03-01

The air-borne sound insulation performance of a rectangular double-panel partition clamp mounted on an infinite acoustic rigid baffle is investigated both analytically and experimentally and compared with that of a simply supported one. With the clamped (or simply supported) boundary accounted for by using the method of modal function, a double series solution for the sound transmission loss (STL) of the structure is obtained by employing the weighted residual (Galerkin) method. Experimental measurements with Al double-panel partitions having air cavity are subsequently carried out to validate the theoretical model for both types of the boundary condition, and good overall agreement is achieved. A consistency check of the two different models (based separately on clamped modal function and simply supported modal function) is performed by extending the panel dimensions to infinite where no boundaries exist. The significant discrepancies between the two different boundary conditions are demonstrated in terms of the STL versus frequency plots as well as the panel deflection mode shapes.

Comparison of seismic margin assessment and probabilistic risk assessment in seismic IPE

International Nuclear Information System (INIS)

Reed, J.W.; Kassawara, R.P.

1993-01-01

A comparison of technical requirements and managerial issues between seismic margin assessment (SMA) and seismic probabilistic risk assessment (SPRA) in a seismic Individual Plant Examination (IPE) is presented and related to requirements for an Unresolved Safety Issue (USI) A-46 review which is required for older nuclear power plants. Advantages and disadvantages are discussed for each approach. Technical requirements reviewed for a seismic IPE include: scope of plants covered, seismic input, scope of review, selection of equipment, required experience and training of engineers, walkdown procedure, evaluation of components, relay review, containment review, quality assurance, products, documentation requirements, and closure procedure. Managerial issues discussed include regulatory acceptability, compatibility with seismic IPE, compliance with seismic IPE requirements, ease of use by utilities, and relative cost

Evaluation of induced seismicity forecast models in the Induced Seismicity Test Bench

Science.gov (United States)

Király, Eszter; Gischig, Valentin; Zechar, Jeremy; Doetsch, Joseph; Karvounis, Dimitrios; Wiemer, Stefan

2016-04-01

Induced earthquakes often accompany fluid injection, and the seismic hazard they pose threatens various underground engineering projects. Models to monitor and control induced seismic hazard with traffic light systems should be probabilistic, forward-looking, and updated as new data arrive. Here, we propose an Induced Seismicity Test Bench to test and rank such models. We apply the test bench to data from the Basel 2006 and Soultz-sous-Forêts 2004 geothermal stimulation projects, and we assess forecasts from two models that incorporate a different mix of physical understanding and stochastic representation of the induced sequences: Shapiro in Space (SiS) and Hydraulics and Seismics (HySei). SiS is based on three pillars: the seismicity rate is computed with help of the seismogenic index and a simple exponential decay of the seismicity; the magnitude distribution follows the Gutenberg-Richter relation; and seismicity is distributed in space based on smoothing seismicity during the learning period with 3D Gaussian kernels. The HySei model describes seismicity triggered by pressure diffusion with irreversible permeability enhancement. Our results show that neither model is fully superior to the other. HySei forecasts the seismicity rate well, but is only mediocre at forecasting the spatial distribution. On the other hand, SiS forecasts the spatial distribution well but not the seismicity rate. The shut-in phase is a difficult moment for both models in both reservoirs: the models tend to underpredict the seismicity rate around, and shortly after, shut-in. Ensemble models that combine HySei's rate forecast with SiS's spatial forecast outperform each individual model.

Robust Clamping Force Control of an Electro-Mechanical Brake System for Application to Commercial City Buses

Directory of Open Access Journals (Sweden)

Sangjune Eum

2017-02-01

Full Text Available This paper proposes a sensor-less robust force control method for improving the control performance of an electro-mechanical brake (EMB which is applicable to commercial city buses. The EMB generates the accurate clamping force commanded by a driver through an independent motor control at each wheel instead of using existing mechanical components. In general, an EMB undergoes parameter variation and a backdrivability problem. For this reason, the cascade control strategy (e.g., force-position cascade control structure is proposed and the disturbance observer is employed to enhance control robustness against model variations. Additionally, this paper proposed the clamping force estimation method for a sensor-less control, i.e., the clamping force observer (CFO. Finally, in order to confirm the performance and effectiveness of a proposed robust control method, several experiments are performed and analyzed.

Feasibility, safety and image quality of cardiac FDG studies during hyperinsulinaemic-euglycaemic clamping

International Nuclear Information System (INIS)

Bax, Jeroen J.; Visser, Frans C.; Lingen, Arthur van; Visser, Cees A.; Poldermans, Don; Elhendy, Abdou; Boersma, Eric

2002-01-01

Fluorine-18 fluorodeoxyglucose (FDG) imaging for the assessment of myocardial viability has become an integral part of the diagnostic and prognostic work-up of patients with ischaemic cardiomyopathy. To ensure good image quality, in particular in patients with diabetes mellitus, hyperinsulinaemic-euglycaemic clamping has been proposed. In this study we evaluated the safety and the image quality of cardiac FDG imaging during clamping in a large group of patients, including a subgroup with diabetes mellitus. The incidence of viability (on both a segment and a patient basis) was also determined for patients with and without diabetes mellitus. The safety and image quality of cardiac FDG studies during clamping were evaluated in 131 patients, including 19 with diabetes mellitus. Image quality was assessed visually and quantitatively using heart-to-lung (H/L), heart-to-liver (H/Li) and myocardium-to-background (M/B) ratios. Blood samples were drawn at baseline and at the time of FDG injection to determine levels of glucose, free fatty acids and insulin. The metabolic circumstances were optimal for FDG imaging: high insulin levels, low free fatty acid levels and glucose levels in the normal range (levels of substrates were comparable between patients with and patients without diabetes mellitus). No serious side-effects occurred in any patient. Image quality (assessed visually) was good in all patients. The quantitative parameters of image quality (H/L, H/Li and M/B) were comparable between patients with and patients without diabetes mellitus. The incidence of viability was high: 38% of patients without and 58% of patients with diabetes mellitus had substantial viability despite contractile dysfunction. It is concluded that cardiac FDG imaging during clamping is safe and provides excellent image quality, including in patients with diabetes mellitus. The incidence of viability is high, in particular in patients with diabetes mellitus. (orig.)

Influence of non-steady state during isoglycemic hyperinsulinemic clamp in hypertension. A LIFE substudy

DEFF Research Database (Denmark)

Olsen, M H; Andersen, U B; Wachtell, K

1999-01-01

We wanted to investigate whether time to steady state was reached within 2 h of insulin infusion during isoglycemic hyperinsulinemic clamp, comparing the glucose uptake index (M/IG) with Bergman's insulin sensitivity index (Sip). We performed a 2-h oral glucose tolerance test and a 3-h isoglycemic....... Because the 2-h M/IG correlated strongly with the 3-h Sip with relatively narrow limits of agreement, it is a good measure of insulin sensitivity. However, a 2-h clamp results in lower insulin sensitivity values in elderly, hypertensive patients due to the fact that steady state is not reached...

Comparison of seismic sources for shallow seismic: sledgehammer and pyrotechnics

Directory of Open Access Journals (Sweden)

Brom Aleksander

2015-10-01

Full Text Available The pyrotechnic materials are one of the types of the explosives materials which produce thermal, luminous or sound effects, gas, smoke and their combination as a result of a self-sustaining chemical reaction. Therefore, pyrotechnics can be used as a seismic source that is designed to release accumulated energy in a form of seismic wave recorded by tremor sensors (geophones after its passage through the rock mass. The aim of this paper was to determine the utility of pyrotechnics for shallow seismic engineering. The work presented comparing the conventional method of seismic wave excitation for seismic refraction method like plate and hammer and activating of firecrackers on the surface. The energy released by various sources and frequency spectra was compared for the two types of sources. The obtained results did not determine which sources gave the better results but showed very interesting aspects of using pyrotechnics in seismic measurements for example the use of pyrotechnic materials in MASW.

Dynamic characteristics of rotating pretwisted clamped-clamped beam under thermal stress

International Nuclear Information System (INIS)

Zhang, Bo; Li, Yueming; Lu, Wei Zhen

2016-01-01

Effects of thermal stress on the vibration characteristics, buckling limit and critical speed of a rotating pretwisted beam clamped to rigid hub at a stagger angle were investigated. By considering the work done by thermal stress, the thermal influence on stiffness matrix was introduced in the dynamic model. The motion equations were derived based on Lagrange equation by employing three pure Cartesian deformation variables combined with nonlinear von Karman strain formula. Numerical investigations studied the modal characteristics of the beam. Numerical results calculated from a commercial finite element code and obtained with the present modeling method were in good agreement with the previous results reported in the literature. The combined softening effects due to the thermal stress and the rotation motion were observed. Furthermore, it is shown that the inclusion of thermal stress is necessary for blades operating under a high temperature field. Buckling thermal loads and the critical rotating speed were calculated through solving the corresponding nonlinear equations numerically, and some pertinent conclusions are outlined. It is also found that the peak value position of the first mode shape approaches to the tip of blade with the increment of rotating speed and hub radius. However, the variation in the environment temperature causes only a slight alteration in the mode shape

Dynamic characteristics of rotating pretwisted clamped-clamped beam under thermal stress

Energy Technology Data Exchange (ETDEWEB)

Zhang, Bo; Li, Yueming [State Key Laboratory for Strength and Vibration of Mechanical Structures, Shaanxi Key Laboratory of Environment and Control for Flight Vehicle, School of Aerospace, Xi' an Jiaotong UniversityXi' an (China); Lu, Wei Zhen [Dept. of Civil and Architectural Engineering, City University of Hong Kong, Hong Kong (China)

2016-09-15

Effects of thermal stress on the vibration characteristics, buckling limit and critical speed of a rotating pretwisted beam clamped to rigid hub at a stagger angle were investigated. By considering the work done by thermal stress, the thermal influence on stiffness matrix was introduced in the dynamic model. The motion equations were derived based on Lagrange equation by employing three pure Cartesian deformation variables combined with nonlinear von Karman strain formula. Numerical investigations studied the modal characteristics of the beam. Numerical results calculated from a commercial finite element code and obtained with the present modeling method were in good agreement with the previous results reported in the literature. The combined softening effects due to the thermal stress and the rotation motion were observed. Furthermore, it is shown that the inclusion of thermal stress is necessary for blades operating under a high temperature field. Buckling thermal loads and the critical rotating speed were calculated through solving the corresponding nonlinear equations numerically, and some pertinent conclusions are outlined. It is also found that the peak value position of the first mode shape approaches to the tip of blade with the increment of rotating speed and hub radius. However, the variation in the environment temperature causes only a slight alteration in the mode shape.

Post-seismic relaxation from geodetic and seismic data

Directory of Open Access Journals (Sweden)

Mikhail V. Rodkin

2017-01-01

Full Text Available We have examined the aftershock sequence and the post-seismic deformation process of the Parkfield earthquake (2004, M = 6, California, USA source area using GPS data. This event was chosen because of the possibility of joint analysis of data from the rather dense local GPS network (from SOPAC Internet archive and of the availability of the rather detailed aftershock sequence data (http://www.ncedc.org/ncedc/catalog-search.html. The relaxation process of post-seismic deformation prolongs about the same 400 days as the seismic aftershock process does. Thus, the aftershock process and the relaxation process in deformation could be the different sides of the same process. It should be noted that the ratio of the released seismic energy and of the GPS obtained deformation is quite different for the main shock and for the aftershock stage. The ratio of the released seismic energy to the deformation value decreases essentially for the post-shock process. The similar change in the seismic energy/deformation value ratio is valid in a few other strong earthquakes. Thus, this decrease seems typical of aftershock sequences testifying for decrease of ratio of elastic to inelastic deformation in the process of post-shock relaxation when the source area appears to be mostly fractured after the main shock occurs, but the healing process had no yet sufficient time to develop.

Seismic texture classification. Final report

Energy Technology Data Exchange (ETDEWEB)

Vinther, R.

1997-12-31

The seismic texture classification method, is a seismic attribute that can both recognize the general reflectivity styles and locate variations from these. The seismic texture classification performs a statistic analysis for the seismic section (or volume) aiming at describing the reflectivity. Based on a set of reference reflectivities the seismic textures are classified. The result of the seismic texture classification is a display of seismic texture categories showing both the styles of reflectivity from the reference set and interpolations and extrapolations from these. The display is interpreted as statistical variations in the seismic data. The seismic texture classification is applied to seismic sections and volumes from the Danish North Sea representing both horizontal stratifications and salt diapers. The attribute succeeded in recognizing both general structure of successions and variations from these. Also, the seismic texture classification is not only able to display variations in prospective areas (1-7 sec. TWT) but can also be applied to deep seismic sections. The seismic texture classification is tested on a deep reflection seismic section (13-18 sec. TWT) from the Baltic Sea. Applied to this section the seismic texture classification succeeded in locating the Moho, which could not be located using conventional interpretation tools. The seismic texture classification is a seismic attribute which can display general reflectivity styles and deviations from these and enhance variations not found by conventional interpretation tools. (LN)

Recent Vs. Historical Seismicity Analysis For Banat Seismic Region (Western Part Of Romania)

OpenAIRE

Oros Eugen; Diaconescu Mihai

2015-01-01

The present day seismic activity from a region reflects the active tectonics and can confirm the seismic potential of the seismogenic sources as they are modelled using the historical seismicity. This paper makes a comparative analysis of the last decade seismicity recorded in the Banat Seismic Region (western part of Romania) and the historical seismicity of the region (Mw≥4.0). Four significant earthquake sequences have been recently localized in the region, three of them nearby the city of...

Trans-Z-source and Γ-Z-source neutral-point-clamped inverters

DEFF Research Database (Denmark)

Wei, Mo; Loh, Poh Chiang; Blaabjerg, Frede

2015-01-01

Z-source neutral-point-clamped (NPC) inverters are earlier proposed for obtaining voltage buck-boost and three-level switching simultaneously. Their performances are, however, constrained by a trade-off between their input-to-output gain and modulation ratio. This trade-off can lead to high...

Seismic changes industry

International Nuclear Information System (INIS)

Taylor, G.

1992-01-01

This paper discusses the growth in the seismic industry as a result of the recent increases in the foreign market. With the decline of communism and the opening of Latin America to exploration, seismic teams have moved out into these areas in support of the oil and gas industry. The paper goes on to discuss the improved technology available for seismic resolution and the subsequent use of computers to field-proof the data while the seismic team is still on-site. It also discusses the effects of new computer technology on reducing the amount of support staff that is required to both conduct and interpret seismic information

Evaluation of diel patterns of relative changes in cell turgor of tomato plants using leaf patch clamp pressure probes

NARCIS (Netherlands)

Lee, K.M.; Driever, S.M.; Heuvelink, E.; Rüger, S.; Zimmermann, U.; Gelder, de A.; Marcelis, L.F.M.

2012-01-01

Relative changes in cell turgor of leaves of well-watered tomato plants were evaluated using the leaf patch clamp pressure probe (LPCP) under dynamic greenhouse climate conditions. Leaf patch clamp pressure changes, a measure for relative changes in cell turgor, were monitored at three different

National Seismic Station

International Nuclear Information System (INIS)

Stokes, P.A.

1982-06-01

The National Seismic Station was developed to meet the needs of regional or worldwide seismic monitoring of underground nuclear explosions to verify compliance with a nuclear test ban treaty. The Station acquires broadband seismic data and transmits it via satellite to a data center. It is capable of unattended operation for periods of at least a year, and will detect any tampering that could result in the transmission of unauthentic seismic data

Targeted Endovascular Temporary Vessel Occlusion with a Reverse Thermosensitive Polymer for Near-Bloodless Partial Nephrectomy: Comparison to Standard Surgical Clamping Techniques

Energy Technology Data Exchange (ETDEWEB)

Flacke, Sebastian, E-mail: Sebastian.Flacke@lahey.org [Lahey Clinic, Tuft University Medical School, Department of Radiology (United States); Harty, Niall J.; Laskey, Daniel H.; Moinzadeh, Alireza [Lahey Clinic, Tuft University Medical School, Department of Urology (United States); Benn, James A. [Pluromed Inc (United States); Villani, Rosanna [DaVinci Biomedical Research Products (United States); Kalra, Aarti [Lahey Clinic, Tuft University Medical School, Department of Pathology (United States); Libertino, John A.; Madras, Peter N. [Lahey Clinic, Tuft University Medical School, Department of Urology (United States)

2012-10-15

Purpose: To determine whether reversible blood flow interruption to a randomly chosen target region of the kidney may be achieved with the injection of a reverse thermoplastic polymer through an angiographic catheter, thereby facilitating partial nephrectomy without compromising blood flow to the remaining kidney or adding risks beyond those encountered by the use of hilar clamping. Methods: Fifteen pigs underwent partial nephrectomy after blood flow interruption by vascular cross-clamping or injection of polymer (Lumagel Trade-Mark-Sign ) into a segmental artery. Five animals were euthanized after surgery (three open and two laparoscopic resection, cross-clamping n = 2), and 10 (open resection, cross-clamping n = 4) were euthanized after 6 weeks' survival. Blood specimens were obtained periodically, and angiogram and necropsy were performed at 6 weeks. Results: Selective renal ischemia was achieved in all cases. Surgical resection time averaged 9 and 24.5 min in the open and laparoscopic groups, respectively. Estimated blood loss was negligible with the exception of one case where an accessory renal artery was originally overlooked. Reversal of the polymer to a liquid state was consistent angiographically and visually in all cases. Time to complete flow return averaged 7.4 and 2 min for polymer and clamping, respectively. Angiography at 6 weeks revealed no evidence of vascular injury. Laboratory data and necropsies revealed no differences between animals undergoing vascular clamping or polymer injection. Conclusion: Lumagel was as effective as vascular clamping in producing a near bloodless operative field for partial nephrectomy while maintaining flow to the uninvolved portion of the affected kidney.

Solution study of the Escherichia coli DNA polymerase III clamp loader reveals the location of the dynamic ψχ heterodimer

Directory of Open Access Journals (Sweden)

Farzaneh Tondnevis

2015-09-01

Full Text Available Several X-ray crystal structures of the E. coli core clamp loader containing the five core (δ′, δ, and three truncated γ subunits have been determined, but they lack the ψ and χ subunits. We report the first solution structure of the complete seven-subunit clamp loader complex using small angle X-ray scattering. This structure not only provides information about the location of the χ and ψ subunits but also provides a model of the dynamic nature of the clamp loader complex.

Design and control of a novel gastroscope intervention mechanism with circumferentially pneumatic-driven clamping function.

Science.gov (United States)

Li, Yanmin; Liu, Hao; Hao, Siwen; Li, Hongyi; Han, Jianda; Yang, Yunsheng

2017-03-01

Robot-assisted manipulation is promising for solving problems such as understaffing and the risk of infection in gastro-intestinal endoscopy. However, the commonly used friction rollers in few existing systems have a potential risk of deforming flexible endoscopes for non-uniform clamping. This paper presents a robotic system for a standard flexible endoscope and focuses on a novel gastroscope intervention mechanism (GIM), which provides circumferentially uniform clamping with an airbag. The GIM works with a relay-on mechanism in a way similar to manual operation. The shear stiffness of airbag and the critical slipping force (CSF) were analysed to determine the parameters of the airbag. A fuzzy PID controller was employed to realize a fast response and high accuracy of pneumatic actuation. Experiments were performed to evaluate the accuracy, stiffness and CSF. In vitro and in vivo animal experiments were also carried out. The GIM realized an accuracy of 0.025 ± 0.2 mm and -0.03 ± 0.25° for push-pull and rotation without delivery resistance. Under polynomial could be used to describe the relationship between the CSF and pneumatic pressure. The novel GIM could effectively deliver gastroscopes. The pneumatic-driven clamping method proposed could protect the gastroscope by circumferentially uniform clamping force and the CSF could be properly controlled to guarantee operating safety. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Overview of seismic margin insights gained from seismic PRA results

International Nuclear Information System (INIS)

Kennedy, R.P.; Sues, R.H.; Campbell, R.D.

1986-01-01

This paper presents the findings of a study conducted under NRC and EPRI sponsorship in which published seismic PRAs were reviewed in order to gain insight to the seismic margins inherent in existing nuclear plants. The approach taken was to examine the fragilities of those components which have been found to be dominant contributors to seismic risk at plants in low-to-moderate seismic regions (SSE levels between 0.12g and 0.25g). It is concluded that there is significant margin inherent in the capacity of most critical components above the plant design basis. For ground motions less than about 0.3g, the predominant sources of seismic risk are loss of offsite power coupled with random failure of the emergency diesels, non-recoverable circuit breaker trip due to relay chatter, unanchored equipment, unreinforced non-load bearing block walls, vertical water storage tanks, systems interactions and possibly soil liquefaction. Recommendations as to which components should be reviewed in seismic margin studies for margin earthquakes less than 0.3g, between 0.3g and 0.5g, and greater than 0.5g, developed by the NRC expert panel on the quantification of seismic margins (based on the review of past PRA data, earthquake experience data, and their own personal experience) are presented

Adding seismic broadband analysis to characterize Andean backarc seismicity in Argentina

Science.gov (United States)

Alvarado, P.; Giuliano, A.; Beck, S.; Zandt, G.

2007-05-01

Characterization of the highly seismically active Andean backarc is crucial for assessment of earthquake hazards in western Argentina. Moderate-to-large crustal earthquakes have caused several deaths, damage and drastic economic consequences in Argentinean history. We have studied the Andean backarc crust between 30°S and 36°S using seismic broadband data available from a previous ("the CHARGE") IRIS-PASSCAL experiment. We collected more than 12 terabytes of continuous seismic data from 22 broadband instruments deployed across Chile and Argentina during 1.5 years. Using free software we modeled full regional broadband waveforms and obtained seismic moment tensor inversions of crustal earthquakes testing for the best focal depth for each event. We also mapped differences in the Andean backarc crustal structure and found a clear correlation with different types of crustal seismicity (i.e. focal depths, focal mechanisms, magnitudes and frequencies of occurrence) and previously mapped terrane boundaries. We now plan to use the same methodology to study other regions in Argentina using near-real time broadband data available from the national seismic (INPRES) network and global seismic networks operating in the region. We will re-design the national seismic network to optimize short-period and broadband seismic station coverage for different network purposes. This work is an international effort that involves researchers and students from universities and national government agencies with the goal of providing more information about earthquake hazards in western Argentina.

Seismic failure modes and seismic safety of Hardfill dam

Directory of Open Access Journals (Sweden)

Kun Xiong

2013-04-01

Full Text Available Based on microscopic damage theory and the finite element method, and using the Weibull distribution to characterize the random distribution of the mechanical properties of materials, the seismic response of a typical Hardfill dam was analyzed through numerical simulation during the earthquakes with intensities of 8 degrees and even greater. The seismic failure modes and failure mechanism of the dam were explored as well. Numerical results show that the Hardfill dam remains at a low stress level and undamaged or slightly damaged during an earthquake with an intensity of 8 degrees. During overload earthquakes, tensile cracks occur at the dam surfaces and extend to inside the dam body, and the upstream dam body experiences more serious damage than the downstream dam body. Therefore, under the seismic conditions, the failure pattern of the Hardfill dam is the tensile fracture of the upstream regions and the dam toe. Compared with traditional gravity dams, Hardfill dams have better seismic performance and greater seismic safety.

Diuretic response to acute hypertension is blunted during angiotensin II clamp

DEFF Research Database (Denmark)

Leong, Patrick K K; Zhang, Yibin; Yang, Li E

2002-01-01

and endogenous lithium clearance increased two- and threefold, respectively. We conclude that HOE-140, an inhibitor of the B(2) receptor, potentiates the sensitivity of arterial pressure to ANG II and that clamping systemic ANG II levels during acute hypertension blunts the magnitude of the pressure diuretic...

A Hybrid Cascade Converter Topology With Series-Connected Symmetrical and Asymmetrical Diode-Clamped H-Bridge Cells

DEFF Research Database (Denmark)

Nami, Alireza; Zare, Firuz; Ghosh, Arindam

2011-01-01

to approach a very low total harmonic distortion of voltage and current, which leads to the possible elimination of the output filter. Regarding the proposed configuration, a new cascade inverter is verified by cascading an asymmetrical diode-clamped inverter, in which 19 levels can be synthesized in output......A novel H-bridge multilevel pulsewidth modulation converter topology based on a series connection of a high-voltage diode-clamped inverter and a low-voltage conventional inverter is proposed in this paper. A dc link voltage arrangement for the new hybrid and asymmetric solution is presented to have...... voltage with the same number of components. To balance the dc link capacitor voltages for the maximum output voltage resolution as well as synthesize asymmetrical dc link combination, a new multi-output boost converter is utilized at the dc link voltage of a seven-level H-bridge diode-clamped inverter...

Impedance spectra of patch clamp scenarios for single cells immobilized on a lab-on-a-chip

DEFF Research Database (Denmark)

Alberti, Massimo; Snakenborg, Detlef; Lopacinska, Joanna M.

2014-01-01

and simulated impedance spectra proved that the presented method could distinguish between a cell-attached mode and a whole-cell mode even with low-quality seals. In physiological conditions, the capacitance of HeLa cells was measured to *38 pF. The first gigaseal was recorded and maintained for 40 min. Once...... membrane. After incubating the chip for 24 h, HeLa cells adhered and grew on the chip surface but did not survive when trapped on the microapertures. The microfluidic system proved to work as a micro electrophysiological analysis system, and the IS-based method can be used for further studies on the post......A simple method based on impedance spectroscopy (IS) was developed to distinguish between different patch clamp modes for single cells trapped on microapertures in a patch clamp microchannel array designed for patch clamping on cultured cells. The method allows detecting via impedance analysis...

Laser microsurgery of higher plant cell walls permits patch-clamp access

International Nuclear Information System (INIS)

Henriksen, G.H.; Taylor, A.R.; Brownlee, C.; Assmann, S.M.

1996-01-01

Plasma membranes of guard cells in epidermal peels of Vicia faba and Commelina communis can be made accessible to a patch-clamp pipet by removing a small portion (1-3 micrometer in diameter) of the guard cell wall using a microbeam of ultraviolet light generated by a nitrogen laser. Using this laser microsurgical technique, we have measured channel activity across plasma membranes of V. faba guard cells in both cell-attached and isolated patch configurations. Measurements made in the inside-out patch configuration revealed two distinct K+-selective channels. Major advantages of the laser microsurgical technique include the avoidance of enzymatic protoplast isolation, the ability to study cell types that have been difficult to isolate as protoplasts or for which enzymatic isolation protocols result in protoplasts not amenable to patch-clamp studies, the maintenance of positional information in single-channel measurements, reduced disruption of cell-wall-mediated signaling pathways, and the ability to investigate intercellular signaling through studies of cells remaining situated within tissue

A Novel Neutral Point Clamped Full-Bridge Topology for Transformerless Photovoltaic Grid-Connected Inverters

Directory of Open Access Journals (Sweden)

M. Pakdel

2017-04-01

Full Text Available This paper presents a novel neutral point clamped full-bridge topology for transformerless photovoltaic grid-tied inverters. Transformerless grid-connected inverters have been used widely in recent years since they offer higher efficiency and lower costs. Ground leakage current suppression is the main issue which should be considered carefully in transformerless photovoltaic grid-connected inverters. Among different methods used to decline ground leakage current, neutral point clamped (NPC topologies are considered more useful and effective. In NPC topologies, the short-circuited output voltage at the freewheeling period is clamped to the middle of the DC bus voltage. Therefore, the common-mode voltage (CM will be constant at the whole switching period. Various NPC topologies such as H6 [1], HB-ZVR [2], oH5 [3], and PN-NPC [4] have been proposed. In this paper, a novel NPC topology is proposed which has lower power losses and higher efficiency over previous topologies. Furthermore, the proposed NPC topology exhibits a similar ground leakage current with the PN-NPC topology. The proposed NPC topology is analyzed theoretically using simulation studies and an experimental prototype is provided to verify theoretical analysis and simulation studies.

Ion channel electrophysiology via integrated planar patch-clamp chip with on-demand drug exchange.

Science.gov (United States)

Chen, Chang-Yu; Tu, Ting-Yuan; Jong, De-Shien; Wo, Andrew M

2011-06-01

Planar patch clamp has revolutionized characterization of ion channel behavior in drug discovery primarily via advancement in high throughput. Lab use of planar technology, however, addresses different requirements and suffers from inflexibility to enable wide range of interrogation via a single cell. This work presents integration of planar patch clamp with microfluidics, achieving multiple solution exchanges for tailor-specific measurement and allowing rapid replacement of the cell-contacting aperture. Studies via endogenously expressed ion channels in HEK 293T cells were commenced to characterize the device. Results reveal the microfluidic concentration generator produces distinct solution/drug combination/concentrations on-demand. Volume-regulated chloride channel and voltage-gated potassium channels in HEK 293T cells immersed in generated solutions under various osmolarities or drug concentrations show unique channel signature under specific condition. Excitation and blockage of ion channels in a single cell was demonstrated via serial solution exchange. Robustness of the reversible bonding and ease of glass substrate replacement were proven via repeated usage of the integrated device. The present approach reveals the capability and flexibility of integrated microfluidic planar patch-clamp system for ion channel assays. Copyright © 2011 Wiley Periodicals, Inc.

Information needs for characterization of high-level waste repository sites in six geologic media. Volume 2. Appendices

Energy Technology Data Exchange (ETDEWEB)

NONE

1985-05-01

Volume II contains appendices for the following: (1) remote sensing and surface mapping techniques; (2) subsurface mapping methods for site characterization; (3) gravity technique; (4) audio-frequency magnetotelluric technique; (5) seismic refraction technique; (6) direct-current electrical resistivity method; (7) magnetic technique; (8) seismic reflection technique; (9) seismic crosshole method; (10) mechanical downhole seismic velocity survey method; (11) borehole geophysical logging techniques; (12) drilling and coring methods for precharacterization studies; (13) subsurface drilling methods for site characterization; (14) geomechanical/thermomechanical techniques for precharacterization studies; (15)geomechanical/thermal techniques for site characterization studies; (16) exploratory geochemical techniques for precharacterization studies; (17) geochemical techniques for site characterization; (18) hydrologic techniques for precharacterization studies; (19) hydrologic techniques for site characterization; and (20) seismological techniques.

Information needs for characterization of high-level waste repository sites in six geologic media. Volume 2. Appendices

International Nuclear Information System (INIS)

1985-05-01

Volume II contains appendices for the following: (1) remote sensing and surface mapping techniques; (2) subsurface mapping methods for site characterization; (3) gravity technique; (4) audio-frequency magnetotelluric technique; (5) seismic refraction technique; (6) direct-current electrical resistivity method; (7) magnetic technique; (8) seismic reflection technique; (9) seismic crosshole method; (10) mechanical downhole seismic velocity survey method; (11) borehole geophysical logging techniques; (12) drilling and coring methods for precharacterization studies; (13) subsurface drilling methods for site characterization; (14) geomechanical/thermomechanical techniques for precharacterization studies; (15)geomechanical/thermal techniques for site characterization studies; (16) exploratory geochemical techniques for precharacterization studies; (17) geochemical techniques for site characterization; (18) hydrologic techniques for precharacterization studies; (19) hydrologic techniques for site characterization; and (20) seismological techniques

Early estimation of epicenter seismic intensities according to co-seismic deformation

OpenAIRE

Weidong, Li; Chaojun, Zhang; Dahui, Li; Jiayong, He; Huizhong, Chen; Lomnitz, Cinna

2010-01-01

The absolute fault displacement in co-seismic deformation is derived assuming that location, depth, faulting mechanism and magnitude of the earthquake are known. The 2008 Wenchuan earthquake (M8.0) is used as an example to determine the distribution of seismic intensities using absolute displacement and a crustal model. We fnd that an early prediction of the distribution of seismic intensities after a large earthquake may be performed from the estimated absolute co-seismic displacements using...

A comparison between the minimal model and the glucose clamp in the assessment of insulin sensitivity across the spectrum of glucose tolerance. Insulin Resistance Atherosclerosis Study.

Science.gov (United States)

Saad, M F; Anderson, R L; Laws, A; Watanabe, R M; Kades, W W; Chen, Y D; Sands, R E; Pei, D; Savage, P J; Bergman, R N

1994-09-01

An insulin-modified frequently sampled intravenous glucose tolerance test (FSIGTT) with minimal model analysis was compared with the glucose clamp in 11 subjects with normal glucose tolerance (NGT), 20 with impaired glucose tolerance (IGT), and 24 with non-insulin-dependent diabetes mellitus (NIDDM). The insulin sensitivity index (SI) was calculated from FSIGTT using 22- and 12-sample protocols (SI(22) and SI(12), respectively). Insulin sensitivity from the clamp was expressed as SI(clamp) and SIP(clamp). Minimal model parameters were similar when calculated with SI(22) and SI(12). SI could not be distinguished from 0 in approximately 50% of diabetic patients with either protocol. SI(22) correlated significantly with SI(clamp) in the whole group (r = 0.62), and in the NGT (r = 0.53), IGT (r = 0.48), and NIDDM (r = 0.41) groups (P SIP(clamp) were expressed in the same units, SI(22) was 66 +/- 5% (mean +/- SE) and 50 +/- 8% lower than SI(clamp) and SIP(clamp), respectively. Thus, minimal model analysis of the insulin-modified FSIGTT provides estimates of insulin sensitivity that correlate significantly with those from the glucose clamp. The correlation was weaker, however, in NIDDM. The insulin-modified FSIGTT can be used as a simple test for assessment of insulin sensitivity in population studies involving nondiabetic subjects. Additional studies are needed before using this test routinely in patients with NIDDM.

Subsurface Rock Physical Properties by Downhole Loggings - Case Studies of Continental Deep Drilling in Kanto Distinct, Japan

Science.gov (United States)

Omura, K.

2014-12-01

In recent years, many examples of physical logging have been carried out in deep boreholes. The loggings are direct in-situ measurements of rock physical properties under the ground. They provide significant basic data for the geological, geophysical and geotechnical investigations, e.g., tectonic history, seismic wave propagation, and ground motion prediction. Since about 1980's, Natl. Res. Inst. for Earth Sci. and Disast. Prev. (NIED) dug deep boreholes (from 200m to 3000m depth) in sedimentary basin of Kanto distinct, Japan, for purposes of installing seismographs and hydrological instruments, and in-situ stress and pore pressure measurements. At that time, downhole physical loggings were conducted in the boreholes: spontaneous potential, electrical resistance, elastic wave velocity, formation density, neutron porosity, total gamma ray, caliper, temperature loggings. In many cases, digital data values were provided every 2m or 1m or 0.1m. In other cases, we read printed graphs of logging plots and got digital data values. Data from about 30 boreholes are compiled. Especially, particular change of logging data at the depth of an interface between a shallow part (soft sedimentary rock) and a base rock (equivalent to hard pre-Neogene rock) is examined. In this presentation, the correlations among physical properties of rock (especially, formation density, elastic wave velocity and electrical resistance) are introduced and the relation to the lithology is discussed. Formation density, elastic wave velocity and electric resistance data indicate the data are divide in two groups that are higher or lower than 2.5g/cm3: the one correspond to a shallow part and the other correspond to a base rock part. In each group, the elastic wave velocity and electric resistance increase with increase of formation density. However the rates of increases in the shallow part are smaller than in the base rock part. The shallow part has lower degree of solidification and higher porosity

Causality between expansion of seismic cloud and maximum magnitude of induced seismicity in geothermal field

Science.gov (United States)

Mukuhira, Yusuke; Asanuma, Hiroshi; Ito, Takatoshi; Häring, Markus

2016-04-01

Occurrence of induced seismicity with large magnitude is critical environmental issues associated with fluid injection for shale gas/oil extraction, waste water disposal, carbon capture and storage, and engineered geothermal systems (EGS). Studies for prediction of the hazardous seismicity and risk assessment of induced seismicity has been activated recently. Many of these studies are based on the seismological statistics and these models use the information of the occurrence time and event magnitude. We have originally developed physics based model named "possible seismic moment model" to evaluate seismic activity and assess seismic moment which can be ready to release. This model is totally based on microseismic information of occurrence time, hypocenter location and magnitude (seismic moment). This model assumes existence of representative parameter having physical meaning that release-able seismic moment per rock volume (seismic moment density) at given field. Seismic moment density is to be estimated from microseismic distribution and their seismic moment. In addition to this, stimulated rock volume is also inferred by progress of microseismic cloud at given time and this quantity can be interpreted as the rock volume which can release seismic energy due to weakening effect of normal stress by injected fluid. Product of these two parameters (equation (1)) provide possible seismic moment which can be released from current stimulated zone as a model output. Difference between output of this model and observed cumulative seismic moment corresponds the seismic moment which will be released in future, based on current stimulation conditions. This value can be translated into possible maximum magnitude of induced seismicity in future. As this way, possible seismic moment can be used to have feedback to hydraulic stimulation operation in real time as an index which can be interpreted easily and intuitively. Possible seismic moment is defined as equation (1), where D

Screening of E. coli β-clamp Inhibitors Revealed that Few Inhibit Helicobacter pylori More Effectively: Structural and Functional Characterization

Directory of Open Access Journals (Sweden)

Preeti Pandey

2018-01-01

Full Text Available The characteristic of interaction with various enzymes and processivity-promoting nature during DNA replication makes β-clamp an important drug target. Helicobacter pylori (H. pylori have several unique features in DNA replication machinery that makes it different from other microorganisms. To find out whether difference in DNA replication proteins behavior accounts for any difference in drug response when compared to E. coli, in the present study, we have tested E. coli β-clamp inhibitor molecules against H. pylori β-clamp. Various approaches were used to test the binding of inhibitors to H. pylori β-clamp including docking, surface competition assay, complex structure determination, as well as antimicrobial assay. Out of five shortlisted inhibitor molecules on the basis of docking score, three molecules, 5-chloroisatin, carprofen, and 3,4-difluorobenzamide were co-crystallized with H. pylori β-clamp and the structures show that they bind at the protein-protein interaction site as expected. In vivo studies showed only two molecules, 5-chloroisatin, and 3,4-difluorobenzamide inhibited the growth of the pylori with MIC values in micro molar range, which is better than the inhibitory effect of the same drugs on E. coli. Therefore, the evaluation of such drugs against H. pylori may explore the possibility to use to generate species-specific pharmacophore for development of new drugs against H. pylori.

Screening of E. coli β-clamp Inhibitors Revealed that Few Inhibit Helicobacter pylori More Effectively: Structural and Functional Characterization.

Science.gov (United States)

Pandey, Preeti; Verma, Vijay; Dhar, Suman Kumar; Gourinath, Samudrala

2018-01-11

The characteristic of interaction with various enzymes and processivity-promoting nature during DNA replication makes β-clamp an important drug target. Helicobacter pylori ( H. pylori ) have several unique features in DNA replication machinery that makes it different from other microorganisms. To find out whether difference in DNA replication proteins behavior accounts for any difference in drug response when compared to E. coli , in the present study, we have tested E. coli β-clamp inhibitor molecules against H. pylori β-clamp. Various approaches were used to test the binding of inhibitors to H. pylori β-clamp including docking, surface competition assay, complex structure determination, as well as antimicrobial assay. Out of five shortlisted inhibitor molecules on the basis of docking score, three molecules, 5-chloroisatin, carprofen, and 3,4-difluorobenzamide were co-crystallized with H. pylori β-clamp and the structures show that they bind at the protein-protein interaction site as expected. In vivo studies showed only two molecules, 5-chloroisatin, and 3,4-difluorobenzamide inhibited the growth of the pylori with MIC values in micro molar range, which is better than the inhibitory effect of the same drugs on E. coli . Therefore, the evaluation of such drugs against H. pylori may explore the possibility to use to generate species-specific pharmacophore for development of new drugs against H. pylori .

Investigating the effect of clamping force on the fatigue life of bolted plates using volumetric approach

International Nuclear Information System (INIS)

Esmaeili, F.; Chakherlou, T. N.; Zehsaz, M.; Hasanifard, S.

2013-01-01

In this paper, the effects of bolt clamping force on the fatigue life for bolted plates made from Al7075-T6 have been studied on the values of notch strength reduction factor obtained by volumetric approach. To attain stress distribution around the notch (hole) which is required for volumetric approach, nonlinear finite element simulations were carried out. To estimate the fatigue life, the available smooth S-N curve of Al7075-T6 and the notch strength reduction factor obtained from volumetric method were used. The estimated fatigue life was compared with the available experimental test results. The investigation shows that there is a good agreement between the life predicted by the volumetric approach and the experimental results for various specimens with different amount of clamping forces. Volumetric approach and experimental results showed that the fatigue life of bolted plates improves because of the compressive stresses created around the plate hole due to clamping force.

Seismic Studies

Energy Technology Data Exchange (ETDEWEB)

R. Quittmeyer

2006-09-25

This technical work plan (TWP) describes the efforts to develop and confirm seismic ground motion inputs used for preclosure design and probabilistic safety 'analyses and to assess the postclosure performance of a repository at Yucca Mountain, Nevada. As part of the effort to develop seismic inputs, the TWP covers testing and analyses that provide the technical basis for inputs to the seismic ground-motion site-response model. The TWP also addresses preparation of a seismic methodology report for submission to the U.S. Nuclear Regulatory Commission (NRC). The activities discussed in this TWP are planned for fiscal years (FY) 2006 through 2008. Some of the work enhances the technical basis for previously developed seismic inputs and reduces uncertainties and conservatism used in previous analyses and modeling. These activities support the defense of a license application. Other activities provide new results that will support development of the preclosure, safety case; these results directly support and will be included in the license application. Table 1 indicates which activities support the license application and which support licensing defense. The activities are listed in Section 1.2; the methods and approaches used to implement them are discussed in more detail in Section 2.2. Technical and performance objectives of this work scope are: (1) For annual ground motion exceedance probabilities appropriate for preclosure design analyses, provide site-specific seismic design acceleration response spectra for a range of damping values; strain-compatible soil properties; peak motions, strains, and curvatures as a function of depth; and time histories (acceleration, velocity, and displacement). Provide seismic design inputs for the waste emplacement level and for surface sites. Results should be consistent with the probabilistic seismic hazard analysis (PSHA) for Yucca Mountain and reflect, as appropriate, available knowledge on the limits to extreme ground

Seismic Studies

International Nuclear Information System (INIS)

R. Quittmeyer

2006-01-01

This technical work plan (TWP) describes the efforts to develop and confirm seismic ground motion inputs used for preclosure design and probabilistic safety 'analyses and to assess the postclosure performance of a repository at Yucca Mountain, Nevada. As part of the effort to develop seismic inputs, the TWP covers testing and analyses that provide the technical basis for inputs to the seismic ground-motion site-response model. The TWP also addresses preparation of a seismic methodology report for submission to the U.S. Nuclear Regulatory Commission (NRC). The activities discussed in this TWP are planned for fiscal years (FY) 2006 through 2008. Some of the work enhances the technical basis for previously developed seismic inputs and reduces uncertainties and conservatism used in previous analyses and modeling. These activities support the defense of a license application. Other activities provide new results that will support development of the preclosure, safety case; these results directly support and will be included in the license application. Table 1 indicates which activities support the license application and which support licensing defense. The activities are listed in Section 1.2; the methods and approaches used to implement them are discussed in more detail in Section 2.2. Technical and performance objectives of this work scope are: (1) For annual ground motion exceedance probabilities appropriate for preclosure design analyses, provide site-specific seismic design acceleration response spectra for a range of damping values; strain-compatible soil properties; peak motions, strains, and curvatures as a function of depth; and time histories (acceleration, velocity, and displacement). Provide seismic design inputs for the waste emplacement level and for surface sites. Results should be consistent with the probabilistic seismic hazard analysis (PSHA) for Yucca Mountain and reflect, as appropriate, available knowledge on the limits to extreme ground motion at

Using Seismic Interferometry to Investigate Seismic Swarms

Science.gov (United States)

Matzel, E.; Morency, C.; Templeton, D. C.

2017-12-01

Seismicity provides a direct means of measuring the physical characteristics of active tectonic features such as fault zones. Hundreds of small earthquakes often occur along a fault during a seismic swarm. This seismicity helps define the tectonically active region. When processed using novel geophysical techniques, we can isolate the energy sensitive to the fault, itself. Here we focus on two methods of seismic interferometry, ambient noise correlation (ANC) and the virtual seismometer method (VSM). ANC is based on the observation that the Earth's background noise includes coherent energy, which can be recovered by observing over long time periods and allowing the incoherent energy to cancel out. The cross correlation of ambient noise between a pair of stations results in a waveform that is identical to the seismogram that would result if an impulsive source located at one of the stations was recorded at the other, the Green function (GF). The calculation of the GF is often stable after a few weeks of continuous data correlation, any perturbations to the GF after that point are directly related to changes in the subsurface and can be used for 4D monitoring.VSM is a style of seismic interferometry that provides fast, precise, high frequency estimates of the Green's function (GF) between earthquakes. VSM illuminates the subsurface precisely where the pressures are changing and has the potential to image the evolution of seismicity over time, including changes in the style of faulting. With hundreds of earthquakes, we can calculate thousands of waveforms. At the same time, VSM collapses the computational domain, often by 2-3 orders of magnitude. This allows us to do high frequency 3D modeling in the fault region. Using data from a swarm of earthquakes near the Salton Sea, we demonstrate the power of these techniques, illustrating our ability to scale from the far field, where sources are well separated, to the near field where their locations fall within each other

Characterization of a patch-clamp microchannel array towards neuronal networks analysis

DEFF Research Database (Denmark)

Alberti, Massimo; Snakenborg, Detlef; Lopacinska, Joanna M.

2010-01-01

for simultaneous patch clamping of cultured cells or neurons in the same network. A disposable silicon/silicon dioxide (Si/SiO2) chip with a microhole array was integrated in a microfluidic system for cell handling, perfusion and electrical recording. Fluidic characterization showed that our PC mu CA can work...

Negligible substrate clamping effect on piezoelectric response in (111)-epitaxial tetragonal Pb(Zr, Ti)O3 films

International Nuclear Information System (INIS)

Yamada, Tomoaki; Yasumoto, Jun; Ito, Daisuke; Yoshino, Masahito; Nagasaki, Takanori; Sakata, Osami; Imai, Yasuhiko; Kiguchi, Takanori; Shiraishi, Takahisa; Shimizu, Takao; Funakubo, Hiroshi

2015-01-01

The converse piezoelectric responses of (111)- and (001)-epitaxial tetragonal Pb(Zr 0.35 Ti 0.65 )O 3 [PZT] films were compared to investigate the orientation dependence of the substrate clamping effect. Synchrotron X-ray diffraction (XRD) and piezoelectric force microscopy revealed that the as-grown (111)-PZT film has a polydomain structure with normal twin boundaries that are changed by the poling process to inclined boundaries, as predicted by Romanov et al. [Phys. Status Solidi A 172, 225 (1999)]. Time-resolved synchrotron XRD under bias voltage showed the negligible impact of substrate clamping on the piezoelectric response in the (111)-PZT film, unlike the case for (001)-PZT film. The origin of the negligible clamping effect in the (111)-PZT film is discussed from the viewpoint of the elastic properties and the compensation of lattice distortion between neighboring domains

Seismic qualification of equipment

International Nuclear Information System (INIS)

Heidebrecht, A.C.; Tso, W.K.

1983-03-01

This report describes the results of an investigation into the seismic qualification of equipment located in CANDU nuclear power plants. It is particularly concerned with the evaluation of current seismic qualification requirements, the development of a suitable methodology for the seismic qualification of safety systems, and the evaluation of seismic qualification analysis and testing procedures

Geomorphology and seismic risk

Science.gov (United States)

Panizza, Mario

1991-07-01

The author analyses the contributions provided by geomorphology in studies suited to the assessment of seismic risk: this is defined as function of the seismic hazard, of the seismic susceptibility, and of the vulnerability. The geomorphological studies applicable to seismic risk assessment can be divided into two sectors: (a) morpho-neotectonic investigations conducted to identify active tectonic structures; (b) geomorphological and morphometric analyses aimed at identifying the particular situations that amplify or reduce seismic susceptibility. The morpho-neotectonic studies lead to the identification, selection and classification of the lineaments that can be linked with active tectonic structures. The most important geomorphological situations that can condition seismic susceptibility are: slope angle, debris, morphology, degradational slopes, paleo-landslides and underground cavities.

Characterization of heterologously expressed transporter genes by patch- and voltage-clamp methods: Application to cyclic nucleotide-dependent responses

KAUST Repository

Lemtiri-Chlieh, Fouad

2013-09-03

The application of patch- and voltage-clamp methods to study ion transport can be limited by many hurdles: the size of the cells to be patched and/or stabbed, the subcellular localization of the molecule of interest, and its density of expression that could be too low even in their own native environment. Functional expression of genes using recombinant DNA technology not only overcomes those hurdles but also affords additional and elegant investigations such as single-point mutation studies and subunit associations/regulations. In this chapter, we give a step-by-step description of two electrophysiological methods, patch clamp and two-electrode voltage clamp (TEVC), that are routinely used in combination with heterologous gene expression to assist researchers interested in the identification and characterization of ion transporters. We describe how to (1) obtain and maintain the cells suitable for the use with each of the above-mentioned methods (i.e., HEK-293 cells and yeast spheroplasts to use with the patch-clamp methodology and Xenopus laevis oocytes with TEVC), (2) transfect/inject them with the gene of interest, and (3) record ion transport activities. © Springer Science+Business Media New York 2013.

Characterization of heterologously expressed transporter genes by patch- and voltage-clamp methods: Application to cyclic nucleotide-dependent responses

KAUST Repository

Lemtiri-Chlieh, Fouad; Ali, Rashid Ayesha

2013-01-01

The application of patch- and voltage-clamp methods to study ion transport can be limited by many hurdles: the size of the cells to be patched and/or stabbed, the subcellular localization of the molecule of interest, and its density of expression that could be too low even in their own native environment. Functional expression of genes using recombinant DNA technology not only overcomes those hurdles but also affords additional and elegant investigations such as single-point mutation studies and subunit associations/regulations. In this chapter, we give a step-by-step description of two electrophysiological methods, patch clamp and two-electrode voltage clamp (TEVC), that are routinely used in combination with heterologous gene expression to assist researchers interested in the identification and characterization of ion transporters. We describe how to (1) obtain and maintain the cells suitable for the use with each of the above-mentioned methods (i.e., HEK-293 cells and yeast spheroplasts to use with the patch-clamp methodology and Xenopus laevis oocytes with TEVC), (2) transfect/inject them with the gene of interest, and (3) record ion transport activities. © Springer Science+Business Media New York 2013.

Seismic sequences in the Sombrero Seismic Zone

Science.gov (United States)

Pulliam, J.; Huerfano, V. A.; ten Brink, U.; von Hillebrandt, C.

2007-05-01

The northeastern Caribbean, in the vicinity of Puerto Rico and the Virgin Islands, has a long and well-documented history of devastating earthquakes and tsunamis, including major events in 1670, 1787, 1867, 1916, 1918, and 1943. Recently, seismicity has been concentrated to the north and west of the British Virgin Islands, in the region referred to as the Sombrero Seismic Zone by the Puerto Rico Seismic Network (PRSN). In the combined seismicity catalog maintained by the PRSN, several hundred small to moderate magnitude events can be found in this region prior to 2006. However, beginning in 2006 and continuing to the present, the rate of seismicity in the Sombrero suddenly increased, and a new locus of activity developed to the east of the previous location. Accurate estimates of seismic hazard, and the tsunamigenic potential of seismic events, depend on an accurate and comprehensive understanding of how strain is being accommodated in this corner region. Are faults locked and accumulating strain for release in a major event? Or is strain being released via slip over a diffuse system of faults? A careful analysis of seismicity patterns in the Sombrero region has the potential to both identify faults and modes of failure, provided the aggregation scheme is tuned to properly identify related events. To this end, we experimented with a scheme to identify seismic sequences based on physical and temporal proximity, under the assumptions that (a) events occur on related fault systems as stress is refocused by immediately previous events and (b) such 'stress waves' die out with time, so that two events that occur on the same system within a relatively short time window can be said to have a similar 'trigger' in ways that two nearby events that occurred years apart cannot. Patterns that emerge from the identification, temporal sequence, and refined locations of such sequences of events carry information about stress accommodation that is obscured by large clouds of

Advancements in Exploration and In-Situ Recovery of Sedimentary-Hosted Uranium

International Nuclear Information System (INIS)

Maerten, Horst; Marsland-Smith, Andrea; Ross, Jonathan; Haschke, Michael; Kalka, Harald; Schubert, Jens

2014-01-01

Context and Outline: • ISR feasibility – determining factors: – What counts?; • High-resolution shallow seismic: – Methodology from ‘oil & gas hunting’ adapted to mineral exploration in sedimentary basins; • New down-hole logging tool: – Advanced PFN technology combined with lithologic logging; • Moving theory to practice: – Reactive-transport modelling for optimizing ISR

Gain-clamping techniques in two-stage double-pass L-band EDFA

Indian Academy of Sciences (India)

Two designs of long-wavelength band erbium-doped fiber amplifier (L-band. EDFA) for gain clamping in double-pass systems are demonstrated and compared. The first design is based on ring laser technique where a backward amplified spontaneous emis- sion (ASE) from the second stage is routed into the feedback loop ...

Analysis of the Pallet Clamping Conditions in Work Positioning

OpenAIRE

L. A. Kolesnikov

2016-01-01

Pallets of automatic transfer lines serve as the technological and work-transfer equipment. However, their design is based on the general principles of designing machine accessories. Calculation of the basic design parameters of work based on their functioning features is fairly relevant.In pallet transfer movement over work positioning there is a mismatch between axes of the basic bushing of a pallet and the clamping locks of positioning. The paper identifies the factors influencing it, and ...

Patterns of Seismicity Associated with USGS Identified Areas of Potentially Induced Seismicity.

Science.gov (United States)

Barnes, Caitlin; Halihan, Todd

2018-03-13

A systematic review across U.S. Geological Survey (USGS) identified potentially induced seismic locations was conducted to discover seismic distance patterns and trends over time away from injection disposal wells. Previous research indicates a 10 km (6 miles) average where the majority of induced seismicity is expected to occur within individual locations, with some areas reporting a larger radius of 35 km (22 miles) to over 70 km (43 miles). This research analyzed earthquake occurrences within nine USGS locations where specified wells were identified as contributors to induced seismicity to determine distance patterns from disposal wells or outward seismic migration over time using established principles of hydrogeology. Results indicate a radius of 31.6 km (20 miles) where 90% of felt earthquakes occur among locations, with the closest proximal felt seismic events, on average, occurring 3 km (1.9 miles) away from injection disposal wells. The results of this research found distance trends across multiple locations of potentially induced seismicity. © 2018, National Ground Water Association.

The Piezo Actuator-Driven Pulsed Water Jet System for Minimizing Renal Damage after Off-Clamp Laparoscopic Partial Nephrectomy.

Science.gov (United States)

Kamiyama, Yoshihiro; Yamashita, Shinichi; Nakagawa, Atsuhiro; Fujii, Shinji; Mitsuzuka, Koji; Kaiho, Yasuhiro; Ito, Akihiro; Abe, Takaaki; Tominaga, Teiji; Arai, Yoichi

2017-09-01

In the setting of partial nephrectomy (PN) for renal cell carcinoma, postoperative renal dysfunction might be caused by surgical procedure. The aim of this study was to clarify the technical safety and renal damage after off-clamp laparoscopic PN (LPN) with a piezo actuator-driven pulsed water jet (ADPJ) system. Eight swine underwent off-clamp LPN with this surgical device, while off-clamp open PN was also performed with radio knife or soft coagulation. The length of the removed kidney was 40 mm, and the renal parenchyma was dissected until the renal calyx became clearly visible. The degree of renal degeneration from the resection surface was compared by Hematoxylin-Eosin staining and immunostaining for 1-methyladenosine, a sensitive marker for the ischemic tissue damage. The mRNA levels of neutrophil gelatinase-associated lipocalin (Ngal), a biomarker for acute kidney injury, were measured by quantitative real-time PCR. Off-clamp LPN with ADPJ system was successfully performed while preserving fine blood vessels and the renal calix with little bleeding. In contrast to other devices, the resection surface obtained with the ADPJ system showed only marginal degree of ischemic changes. Indeed, the expression level of Ngal mRNA was lower in the resection surface obtained with the ADPJ system than that with soft coagulation (p = 0.02). Furthermore, using the excised specimens of renal cell carcinoma, we measured the breaking strength at each site of the human kidney, suggesting the applicability of this ADPJ to clinical trials. In conclusion, off-clamp LPN with the ADPJ system could be safely performed with attenuated renal damage.

Seismic proving test of process computer systems with a seismic floor isolation system

International Nuclear Information System (INIS)

Fujimoto, S.; Niwa, H.; Kondo, H.

1995-01-01

The authors have carried out seismic proving tests for process computer systems as a Nuclear Power Engineering Corporation (NUPEC) project sponsored by the Ministry of International Trade and Industry (MITI). This paper presents the seismic test results for evaluating functional capabilities of process computer systems with a seismic floor isolation system. The seismic floor isolation system to isolate the horizontal motion was composed of a floor frame (13 m x 13 m), ball bearing units, and spring-damper units. A series of seismic excitation tests was carried out using a large-scale shaking table of NUPEC. From the test results, the functional capabilities during large earthquakes of computer systems with a seismic floor isolation system were verified

Seismic gaps and plate tectonics: seismic potential for major boundaries

Energy Technology Data Exchange (ETDEWEB)

McCann, W R; Nishenko, S P; Sykes, L R; Krause, J

1979-01-01

The theory of plate tectonics provides a basic framework for evaluating the potential for future great earthquakes to occur along major plate boundaries. Along most of the transform and convergent plate boundaries considered in this paper, the majority of seismic slip occurs during large earthquakes, i.e., those of magnitude 7 or greater. The concepts that rupture zones, as delineated by aftershocks, tend to abut rather than overlap, and large events occur in regions with histories of both long-and short-term seismic quiescence are used in this paper to delineate major seismic gaps. The term seismic gap is taken to refer to any region along an active plate boundary that has not experienced a large thrust or strike-slip earthquake for more than 30 years. A region of high seismic potential is a seismic gap that, for historic or tectonic reasons, is considered likely to produce a large shock during the next few decades. The seismic gap technique provides estimates of the location, size of future events and origin time to within a few tens of years at best. The accompanying map summarizes six categories of seismic potential for major plate boundaries in and around the margins of the Pacific Ocean and the Caribbean, South Sandwich and Sunda (Indonesia) regions for the next few decades. These six categories are meant to be interpreted as forecasts of the location and size of future large shocks and should not be considered to be predictions in which a precise estimate of the time of occurrence is specified. The categories of potential assigned here provide a rationale for assigning priorities for instrumentation, for future studies aimed at predicting large earthquakes and for making estimates of tsunami potential.

Fast and objective detection and analysis of structures in downhole images

Science.gov (United States)

Wedge, Daniel; Holden, Eun-Jung; Dentith, Mike; Spadaccini, Nick

2017-09-01

Downhole acoustic and optical televiewer images, and formation microimager (FMI) logs are important datasets for structural and geotechnical analyses for the mineral and petroleum industries. Within these data, dipping planar structures appear as sinusoids, often in incomplete form and in abundance. Their detection is a labour intensive and hence expensive task and as such is a significant bottleneck in data processing as companies may have hundreds of kilometres of logs to process each year. We present an image analysis system that harnesses the power of automated image analysis and provides an interactive user interface to support the analysis of televiewer images by users with different objectives. Our algorithm rapidly produces repeatable, objective results. We have embedded it in an interactive workflow to complement geologists' intuition and experience in interpreting data to improve efficiency and assist, rather than replace the geologist. The main contributions include a new image quality assessment technique for highlighting image areas most suited to automated structure detection and for detecting boundaries of geological zones, and a novel sinusoid detection algorithm for detecting and selecting sinusoids with given confidence levels. Further tools are provided to perform rapid analysis of and further detection of structures e.g. as limited to specific orientations.

2D and 3D assessment of sustentaculum tali screw fixation with or without Screw Targeting Clamp.

Science.gov (United States)

De Boer, A Siebe; Van Lieshout, Esther M M; Vellekoop, Leonie; Knops, Simon P; Kleinrensink, Gert-Jan; Verhofstad, Michael H J

2017-12-01

Precise placement of sustentaculum tali screw(s) is essential for restoring anatomy and biomechanical stability of the calcaneus. This can be challenging due to the small target area and presence of neurovascular structures on the medial side. The aim was to evaluate the precision of positioning of the subchondral posterior facet screw and processus anterior calcanei screw with or without a Screw Targeting Clamp. The secondary aim was to evaluate the added value of peroperative 3D imaging over 2D radiographs alone. Twenty Anubifix™ embalmed, human anatomic lower limb specimens were used. A subchondral posterior facet screw and a processus anterior calcanei screw were placed using an extended lateral approach. A senior orthopedic trauma surgeon experienced in calcaneal fracture surgery and a senior resident with limited experience in calcaneal surgery performed screw fixation in five specimens with and in five specimens without the clamp. 2D lateral and axial radiographs and a 3D recording were obtained postoperatively. Anatomical dissection was performed postoperatively as a diagnostic golden standard in order to obtain the factual screw positions. Blinded assessment of quality of fixation was performed by two surgeons. In 2D, eight screws were considered malpositioned when placed with the targeting device versus nine placed freehand. In 3D recordings, two additional screws were malpositioned in each group as compared to the golden standard. As opposed to the senior surgeon, the senior resident seemed to get the best results using the Screw Targeting Clamp (number of malpositioned screws using freehand was eight, and using the targeting clamp five). In nine out of 20 specimens 3D images provided additional information concerning target area and intra-articular placement. Based on the 3D assessment, five additional screws would have required repositioning. Except for one, all screw positions were rated equally after dissection when compared with 3D examinations

Recent Vs. Historical Seismicity Analysis For Banat Seismic Region (Western Part Of Romania

Directory of Open Access Journals (Sweden)

Oros Eugen

2015-03-01

Full Text Available The present day seismic activity from a region reflects the active tectonics and can confirm the seismic potential of the seismogenic sources as they are modelled using the historical seismicity. This paper makes a comparative analysis of the last decade seismicity recorded in the Banat Seismic Region (western part of Romania and the historical seismicity of the region (Mw≥4.0. Four significant earthquake sequences have been recently localized in the region, three of them nearby the city of Timisoara (January 2012 and March 2013 and the fourth within Hateg Basin, South Carpathians (October 2013. These sequences occurred within the epicentral areas of some strong historical earthquakes (Mw≥5.0. The main events had some macroseismic effects on people up to some few kilometers from the epicenters. Our results update the Romanian earthquakes catalogue and bring new information along the local seismic hazard sources models and seismotectonics.

Back-Projection Imaging of extended, high-frequency pre-, co-, and post-eruptive seismicity at El Jefe Geyser, El Tatio Geyser Field, Chile

Science.gov (United States)

Kelly, C. L.; Lawrence, J. F.; Beroza, G. C.

2017-12-01

and over multiple eruption cycles. We target specific seismic observations by restricting the frequency band of analysis (i.e., high or low frequency bands), and use our results to evaluate changes in source distributions before, during and after eruptions and compare them to synchronous surface observations (downhole pressure/temperature, discharge rate, thermal video).

Delineation of seismic source zones based on seismicity parameters ...

Indian Academy of Sciences (India)

these source zones were evaluated and were used in the hazard evaluation. ... seismic sources, linear and areal, were considered in the present study to model the seismic sources in the ..... taken as an authentic reference manual for iden-.

Micro-seismicity and seismic moment release within the Coso Geothermal Field, California

Science.gov (United States)

Kaven, Joern; Hickman, Stephen H.; Davatzes, Nicholas C.

2014-01-01

We relocate 16 years of seismicity in the Coso Geothermal Field (CGF) using differential travel times and simultaneously invert for seismic velocities to improve our knowledge of the subsurface geologic and hydrologic structure. We expand on our previous results by doubling the number of relocated events from April 1996 through May 2012 using a new field-wide 3-D velocity model. Relocated micro-seismicity sharpens in many portions of the active geothermal reservoir, likely defining large-scale fault zones and fluid pressure compartment boundaries. However, a significant fraction of seismicity remains diffuse and does not cluster into sharply defined structures, suggesting that permeability is maintained within the reservoir through distributed brittle failure. The seismic velocity structure reveals heterogeneous distributions of compressional (Vp) and shear (Vs) wave speed, with Vs generally higher in the Main Field and East Flank and Vp remaining relatively uniform across the CGF, but with significant local variations. The Vp/Vs ratio appears to outline the two main producing compartments of the reservoir at depths below mean ground level of approximately 1 to 2.5 km, with a ridge of relatively high Vp/Vs separating the Main Field from the East Flank. Detailed analyses of spatial and temporal variations in earthquake relocations and cumulative seismic moment release in the East Flank reveal three regions with persistently high rates of seismic activity. Two of these regions exhibit sharp, stationary boundaries at the margins of the East Flank that likely represent barriers to fluid flow and advective heat transport. However, seismicity and moment release in a third region at the northern end of the East Flank spread over time to form an elongated NE to SW structure, roughly parallel both to an elongated cluster of seismicity at the southern end of the East Flank and to regional fault traces mapped at the surface. Our results indicate that high

Investigating ion channel conformational changes using voltage clamp fluorometry.

Science.gov (United States)

Talwar, Sahil; Lynch, Joseph W

2015-11-01

Ion channels are membrane proteins whose functions are governed by conformational changes. The widespread distribution of ion channels, coupled with their involvement in most physiological and pathological processes and their importance as therapeutic targets, renders the elucidation of these conformational mechanisms highly compelling from a drug discovery perspective. Thanks to recent advances in structural biology techniques, we now have high-resolution static molecular structures for members of the major ion channel families. However, major questions remain to be resolved about the conformational states that ion channels adopt during activation, drug modulation and desensitization. Patch-clamp electrophysiology has long been used to define ion channel conformational states based on functional criteria. It achieves this by monitoring conformational changes at the channel gate and cannot detect conformational changes occurring in regions distant from the gate. Voltage clamp fluorometry involves labelling cysteines introduced into domains of interest with environmentally sensitive fluorophores and inferring structural rearrangements from voltage or ligand-induced fluorescence changes. Ion channel currents are monitored simultaneously to verify the conformational status. By defining real time conformational changes in domains distant from the gate, this technique provides unexpected new insights into ion channel structure and function. This review aims to summarise the methodology and highlight recent innovative applications of this powerful technique. This article is part of the Special Issue entitled 'Fluorescent Tools in Neuropharmacology'. Copyright © 2015 Elsevier Ltd. All rights reserved.

Voltage clamp methods for the study of membrane currents and SR Ca2+ release in adult skeletal muscle fibres

Science.gov (United States)

Hernández-Ochoa, Erick O.; Schneider, Martin F.

2012-01-01

Skeletal muscle excitation-contraction (E-C)1 coupling is a process composed of multiple sequential stages, by which an action potential triggers sarcoplasmic reticulum (SR)2 Ca2+ release and subsequent contractile activation. The various steps in the E-C coupling process in skeletal muscle can be studied using different techniques. The simultaneous recordings of sarcolemmal electrical signals and the accompanying elevation in myoplasmic Ca2+, due to depolarization-initiated SR Ca2+ release in skeletal muscle fibres, have been useful to obtain a better understanding of muscle function. In studying the origin and mechanism of voltage dependency of E-C coupling a variety of different techniques have been used to control the voltage in adult skeletal fibres. Pioneering work in muscles isolated from amphibians or crustaceans used microelectrodes or ‘high resistance gap’ techniques to manipulate the voltage in the muscle fibres. The development of the patch clamp technique and its variant, the whole-cell clamp configuration that facilitates the manipulation of the intracellular environment, allowed the use of the voltage clamp techniques in different cell types, including skeletal muscle fibres. The aim of this article is to present an historical perspective of the voltage clamp methods used to study skeletal muscle E-C coupling as well as to describe the current status of using the whole-cell patch clamp technique in studies in which the electrical and Ca2+ signalling properties of mouse skeletal muscle membranes are being investigated. PMID:22306655

Down-hole catalytic upgrading of heavy crude oil

Energy Technology Data Exchange (ETDEWEB)

Weissman, J.G.; Kessler, R.V.; Sawicki, R.A.; Belgrave, J.D.M.; Laureshen, C.J.; Mehta, S.A.; Moore, R.G.; Ursenbach, M.G. [University of Calgary, Calgary, AB (Canada). Dept. of Chemical and Petroleum Engineering

1996-07-01

Several processing options have been developed to accomplish near-well bore in-situ upgrading of heavy crude oils. These processes are designed to pass oil over a fixed bed of catalyst prior to entering the production well, the catalyst being placed by conventional gravel pack methods. The presence of brine and the need to provide heat and reactant gases in a down-hole environment provide challenges not present in conventional processing. These issues were addressed and the processes demonstrated by use of a modified combustion tube apparatus. Middle-Eastern heavy crude oil and the corresponding brine were used at the appropriate reservoir conditions. In-situ combustion was used to generate reactive gases and to drive fluids over a heated sand or catalysts bed, simulating the catalyst contacting portion of the proposed processes. The heavy crude oil was found to be amenable to in-situ combustion at anticipated reservoir conditions, with a relatively low air requirement. Forcing the oil to flow over a heated zone prior to production results in some upgrading of the oil, as compared to the original oil, due to thermal effects. Passing the oil over a hydroprocessing catalyst located in the heated zone results in a product that is significantly upgraded as compared to either the original oil or thermally processed oil. Catalytic upgrading is due to hydrogenation and the results in about a 50% sulfur removal and an 8{degree} API gravity increase. Additionally, the heated catalyst was found to be efficient at converting CO to additional H{sub 2}. While all of the technologies needed for a successful field trial of in-situ catalytic upgrading exist, a demonstration has yet to be undertaken. 27 refs., 5 figs., 5 tabs.

Seismic monitoring of hydraulic fracturing: techniques for determining fluid flow paths and state of stress away from a wellbore

Energy Technology Data Exchange (ETDEWEB)

Fehler, M.; House, L.; Kaieda, H.

1986-01-01

Hydraulic fracturing has gained in popularity in recent years as a way to determine the orientations and magnitudes of tectonic stresses. By augmenting conventional hydraulic fracturing measurements with detection and mapping of the microearthquakes induced by fracturing, we can supplement and idependently confirm information obtained from conventional analysis. Important information obtained from seismic monitoring includes: the state of stress of the rock, orientation and spacing of the major joint sets, and measurements of rock elastic parameters at locations distant from the wellbore. While conventional well logging operations can provide information about several of these parameters, the zone of interrogation is usually limited to the immediate proximity of the borehole. The seismic waveforms of the microearthquakes contain a wealth of information about the rock in regions that are otherwise inaccessible for study. By reliably locating the hypocenters of many microearthquakes, we have inferred the joint patterns in the rock. We observed that microearthquake locations do not define a simple, thin, planar distribution, that the fault plane solutions are consistent with shear slippage, and that spectral analysis indicates that the source dimensions and slip along the faults are small. Hence we believe that the microearthquakes result from slip along preexisting joints, and not from tensile extension at the tip of the fracture. Orientations of the principal stresses can be estimated by using fault plane solutions of the larger microearthquakes. By using a joint earthquake location scheme, and/or calibrations with downhole detonators, rock velocities and heterogeneities thereof can be investigated in rock volumes that are far enough from the borehole to be representative of intrincis rock properties.

Fault diagnosis of downhole drilling incidents using adaptive observers and statistical change detection

DEFF Research Database (Denmark)

Willersrud, Anders; Blanke, Mogens; Imsland, Lars

2015-01-01

Downhole abnormal incidents during oil and gas drilling causes costly delays, any may also potentially lead to dangerous scenarios. Dierent incidents willcause changes to dierent parts of the physics of the process. Estimating thechanges in physical parameters, and correlating these with changes ...... expectedfrom various defects, can be used to diagnose faults while in development.This paper shows how estimated friction parameters and ow rates can de-tect and isolate the type of incident, as well as isolating the position of adefect. Estimates are shown to be subjected to non......-Gaussian,t-distributednoise, and a dedicated multivariate statistical change detection approach isused that detects and isolates faults by detecting simultaneous changes inestimated parameters and ow rates. The properties of the multivariate di-agnosis method are analyzed, and it is shown how detection and false alarmprobabilities...... are assessed and optimized using data-based learning to obtainthresholds for hypothesis testing. Data from a 1400 m horizontal ow loop isused to test the method, and successful diagnosis of the incidents drillstringwashout (pipe leakage), lost circulation, gas in ux, and drill bit plugging aredemonstrated....

Development of Canadian seismic design approach and overview of seismic standards

Energy Technology Data Exchange (ETDEWEB)

Usmani, A. [Amec Foster Wheeler, Toronto, ON (Canada); Aziz, T. [TSAziz Consulting Inc., Mississauga, ON (Canada)

2015-07-01

Historically the Canadian seismic design approaches have evolved for CANDU® nuclear power plants to ensure that they are designed to withstand a design basis earthquake (DBE) and have margins to meet the safety requirements of beyond DBE (BDBE). While the Canadian approach differs from others, it is comparable and in some cases more conservative. The seismic requirements are captured in five CSA nuclear standards which are kept up to date and incorporate lessons learnt from recent seismic events. This paper describes the evolution of Canadian approach, comparison with others and provides an overview and salient features of CSA seismic standards. (author)

Vertical seismic profile data from well Mallik 2L-38 for gas hydrate studies

Energy Technology Data Exchange (ETDEWEB)

Mi, Y [Calgary Univ., AB (Canada). Dept. of Geology and Geophysics; Walia, R [Victoria Univ., BC (Canada) School of Earth and Ocean Sciences; Hyndman, R [Geological Survey of Canada, Sidney, BC (Canada) Pacific Geoscience Centre

1999-07-01

A gas hydrate research well was drilled in the Canadian Arctic to study gas hydrates in a permafrost setting in a collaborative research project between the Japan National Oil Corp., the Geological Survey of Canada and other agencies. The multidisciplinary study included an electromagnetic survey, permafrost and gas hydrate coring, comprehensive downhole geophysical logging and measurement. Laboratory studies concerned studies on recovered cuttings and core including sedimentology, physical properties, geochemistry, and reservoir characteristics of the Mallik gas accumulation. As part of the Mallik 2L-38 field program, a vertical seismic profiling survey was conducted at zero and other offset source positions with three component receiver tools and horizontal and vertical vibration sources. A special effort was made to record shear wave data, which will be used to estimate the effect of gas hydrate on formation velocities and to determine gas hydrate concentration as a function of the Mallik gas accumulation. From the initial VSP analysis, certain conclusions follow: 1) zero offset vertical vibration component Z and horizontal X component data give reliable velocity determination within the gas hydrate formation zone. P wave velocities from offset VSP data show an excellent consistency with that from offset data and with the sonic log. And 2) the VSP data permit reliable identification of gas hydrate bearing zones. Abstract only included.

Rescaled Range analysis of Induced Seismicity: rapid classification of clusters in seismic crisis

Science.gov (United States)

Bejar-Pizarro, M.; Perez Lopez, R.; Benito-Parejo, M.; Guardiola-Albert, C.; Herraiz, M.

2017-12-01

Different underground fluid operations, mainly gas storing, fracking and water pumping, can trigger Induced Seismicity (IS). This seismicity is normally featured by small-sized earthquakes (M<2.5), although particular cases reach magnitude as great as 5. It has been up for debate whether earthquakes greater than 5 can be triggered by IS or this level of magnitude only corresponds to tectonic earthquakes caused by stress change. Whatever the case, the characterization of IS for seismic clusters and seismic series recorded close but not into the gas storage, is still under discussion. Time-series of earthquakes obey non-linear patterns where the Hurst exponent describes the persistency or anti-persistency of the sequence. Natural seismic sequences have an H-exponent close to 0.7, which combined with the b-value time evolution during the time clusters, give us valuable information about the stationarity of the phenomena. Tectonic earthquakes consist in a main shock with a decay of time-occurrence of seismic shocks obeying the Omori's empirical law. On the contrary, IS does not exhibit a main shock and the time occurrence depends on the injection operations instead of on the tectonic energy released. In this context, the H-exponent can give information about the origin of the sequence. In 2013, a seismic crisis was declared from the Castor underground gas storing located off-shore in the Mediterranean Sea, close to the Northeastern Spanish cost. The greatest induced earthquake was 3.7. However, a 4.2 earthquake, probably of tectonic origin, occurred few days after the operations stopped. In this work, we have compared the H-exponent and the b-value time evolution according to the timeline of gas injection. Moreover, we have divided the seismic sequence into two groups: (1) Induced Seismicity and (2) Triggered Seismicity. The rescaled range analysis allows the differentiation between natural and induced seismicity and gives information about the persistency and long

del Nido versus St. Thomas Cardioplegia Solutions: A Single-Center Retrospective Analysis of Post Cross-Clamp Defibrillation Rates.

Science.gov (United States)

Buel, Shane T; Striker, Carrie Whittaker; O'Brien, James E

2016-06-01

There are many cardioplegia solutions currently in use for pediatric cardiopulmonary bypass (CPB). The most common being del Nido solution. Another common cardioplegia solution used for pediatric CPB is St. Thomas. In October 2014, Children's Mercy Kansas City changed from the use of modified St. Thomas to del Nido. This study compared rates of post cross-clamp fibrillation requiring defibrillation between del Nido solution and modified St. Thomas solution stratified by weight at Children's Mercy Kansas City. This retrospective study consisted of 394 patients who underwent cardiac surgery requiring cardioplegia between January 1, 2014 and July 31, 2015. The outcome measured was defibrillation upon cross-clamp removal. Statistical significance was determined using Fishers exact test with a two-sided significance level of .05. Incidence of defibrillation post cross-clamp removal was 4.4% in the del Nido group and 26.8% in the St. Thomas group (p Thomas group (p Thomas group (p Thomas group (p 60-kg category had an incidence of defibrillation of 16.7% in the del Nido group and 63% in the St. Thomas group (p Thomas and del Nido cardioplegia solutions. Analyses of weight stratifications demonstrate a decrease in the rate of defibrillation post cross-clamp removal in all categories within the del Nido group.

Seismic intrusion detector system

Science.gov (United States)

Hawk, Hervey L.; Hawley, James G.; Portlock, John M.; Scheibner, James E.

1976-01-01

A system for monitoring man-associated seismic movements within a control area including a geophone for generating an electrical signal in response to seismic movement, a bandpass amplifier and threshold detector for eliminating unwanted signals, pulse counting system for counting and storing the number of seismic movements within the area, and a monitoring system operable on command having a variable frequency oscillator generating an audio frequency signal proportional to the number of said seismic movements.

Quantitative Seismic Amplitude Analysis

NARCIS (Netherlands)

Dey, A.K.

2011-01-01

The Seismic Value Chain quantifies the cyclic interaction between seismic acquisition, imaging and reservoir characterization. Modern seismic innovation to address the global imbalance in hydrocarbon supply and demand requires such cyclic interaction of both feed-forward and feed-back processes.

Co-ordinated research programme on benchmark study for the seismic analysis and testing of WWER-type nuclear power plants. V. 3H. Kozloduy NPP units 5/6: Analysis and testing. Working material

International Nuclear Information System (INIS)

1999-01-01

In August 1991, following the SMiRT-11 Conference in Tokyo, a Technical Committee Meeting was held on the 'Seismic safety issues relating to existing NPPs'. The Proceedings of this TCM was subsequently compiled in an IAEA Working Material. One of the main recommendations of this TCM, called for the harmonization of criteria and methods used in Member States in seismic reassessment and upgrading of existing NPPs. Twenty four institutions from thirteen countries participated in the CRP named 'Benchmark study for the seismic analysis and testing of WWER type NPPs'. Two types of WWER reactors (WWER-1000 and WWER-440/213) selected for benchmarking. Kozloduy NPP Units 5/6 and Paks NPP represented these respectively as prototypes. Consistent with the recommendations of the TCM and the working paper prepared by the subsequent Consultants' Meeting, the focal activity of the CRP was the benchmarking exercises. A similar methodology was followed both for Paks NPP and Kozloduy NPP Unit 5. Firstly, the NPP (mainly the reactor building) was tested using a blast loading generated by a series of explosions from buried TNT charges. Records from this test were obtained at several free field locations (both downhole and surface), foundation mat, various elevations of structures as well as some tanks and the stack. Then the benchmark participants were provided with structural drawings, soil data and the free field record of the blast experiment. Their task was to make a blind prediction of the response at preselected locations. The analytical results from these participants were then compared with the results from the test. Although the benchmarking exercises constituted the focus of the CRP, there were many other interesting problems related to the seismic safety of WWER type NPPs which were addressed by the participants. These involved generic studies, i.e. codes and standards used in original WWER designs and their comparison with current international practice; seismic analysis

Seismic Design of a Single Bored Tunnel: Longitudinal Deformations and Seismic Joints

Science.gov (United States)

Oh, J.; Moon, T.

2018-03-01

The large diameter bored tunnel passing through rock and alluvial deposits subjected to seismic loading is analyzed for estimating longitudinal deformations and member forces on the segmental tunnel liners. The project site has challenges including high hydrostatic pressure, variable ground profile and high seismic loading. To ensure the safety of segmental tunnel liner from the seismic demands, the performance-based two-level design earthquake approach, Functional Evaluation Earthquake and Safety Evaluation Earthquake, has been adopted. The longitudinal tunnel and ground response seismic analyses are performed using a three-dimensional quasi-static linear elastic and nonlinear elastic discrete beam-spring elements to represent segmental liner and ground spring, respectively. Three components (longitudinal, transverse and vertical) of free-field ground displacement-time histories evaluated from site response analyses considering wave passage effects have been applied at the end support of the strain-compatible ground springs. The result of the longitudinal seismic analyses suggests that seismic joint for the mitigation measure requiring the design deflection capacity of 5-7.5 cm is to be furnished at the transition zone between hard and soft ground condition where the maximum member forces on the segmental liner (i.e., axial, shear forces and bending moments) are induced. The paper illustrates how detailed numerical analyses can be practically applied to evaluate the axial and curvature deformations along the tunnel alignment under difficult ground conditions and to provide the seismic joints at proper locations to effectively reduce the seismic demands below the allowable levels.

Acute phase response in lactating dairy cows during hyperinsulinemic hypoglycaemic and hyperinsulinemic euglycaemic clamps and after intramammary LPS challenge.

Science.gov (United States)

De Matteis, L; Bertoni, G; Lombardelli, R; Wellnitz, O; Van Dorland, H A; Vernay, M C M B; Bruckmaier, R M; Trevisi, E

2017-06-01

The link between energy availability, turnover of energy substrates and the onset of inflammation in dairy cows is complex and poorly investigated. To clarify this, plasma inflammatory variables were measured in mid-lactating dairy cows allocated to three groups: hyperinsulinemic hypoglycaemic clamp, induced by insulin infusion (HypoG, n = 5); hyperinsulinemic euglycaemic clamp, induced by insulin and glucose infusion (EuG; n = 6); control, receiving a saline solution infusion (NaCl; n = 6). At 48 h after the start of i.v. infusions, two udder quarters per cow were challenged with 200 μg of E. coli lipopolysaccharide (LPS). Individual blood samples were taken before clamps, before LPS challenge (i.e. 48 h after clamps) and 6.5 h after. At 48 h, positive acute phase proteins (posAPP) did not differ among groups, whereas albumin and cholesterol (index of lipoproteins), negative APP (negAPP), were lower (p insulin at the tissue-level makes dairy cows more susceptible to inflammatory events. In contrast, HypoG seems to attenuate the inflammatory response. Journal of Animal Physiology and Animal Nutrition © 2016 Blackwell Verlag GmbH.

Mapping porosity of the deep critical zone in 3D using near-surface geophysics, rock physics modeling, and drilling

Science.gov (United States)

Flinchum, B. A.; Holbrook, W. S.; Grana, D.; Parsekian, A.; Carr, B.; Jiao, J.

2017-12-01

Porosity is generated by chemical, physical and biological processes that work to transform bedrock into soil. The resulting porosity structure can provide specifics about these processes and can improve understanding groundwater storage in the deep critical zone. Near-surface geophysical methods, when combined with rock physics and drilling, can be a tool used to map porosity over large spatial scales. In this study, we estimate porosity in three-dimensions (3D) across a 58 Ha granite catchment. Observations focus on seismic refraction, downhole nuclear magnetic resonance logs, downhole sonic logs, and samples of core acquired by push coring. We use a novel petrophysical approach integrating two rock physics models, a porous medium for the saprolite and a differential effective medium for the fractured rock, that drive a Bayesian inversion to calculate porosity from seismic velocities. The inverted geophysical porosities are within about 0.05 m3/m3 of lab measured values. We extrapolate the porosity estimates below seismic refraction lines to a 3D volume using ordinary kriging to map the distribution of porosity in 3D up to depths of 80 m. This study provides a unique map of porosity on scale never-before-seen in critical zone science. Estimating porosity on these large spatial scales opens the door for improving and understanding the processes that shape the deep critical zone.

Impact of delayed umbilical cord clamping on public cord blood donations: can we help future patients and benefit infant donors?

Science.gov (United States)

Ciubotariu, Rodica; Scaradavou, Andromachi; Ciubotariu, Ilinca; Tarnawski, Michal; Lloyd, Sara; Albano, Maria; Dobrila, Ludy; Rubinstein, Pablo; Grunebaum, Amos

2018-03-25

Cord blood (CB) is a widely accepted stem cell source and its clinical utilization depends, to a great extent, on its cell content. Birth-to-clamping (BTC) time of umbilical cord determines placental transfusion to the newborn, and the remaining blood that can be collected and banked. The 2017 Committee Opinion of the American College of Obstetrics and Gynecologists (ACOG) recommends a delay of "at least 30-60 seconds" before clamping the cord for all newborns to ensure adequate iron stores. The impact of delayed cord clamping (DCC) on public CB banking can be substantial. Cord blood units (CBUs) collected from 1210 mothers at one hospital were evaluated for total nucleated cells (TNCs) and weight/volume based on time to clamping. Bank staff recorded BTC time in seconds as reported by obstetricians; collections were performed ex utero. Immediate clamping was defined as BTC of less than 30 seconds, whereas DCC was defined as BTC of 30 seconds or more. Cord clamping was immediate in 903 (75%) and delayed in 307 (25%) deliveries. Successful recovery (% clinical CBUs) decreased 10-fold with DCC of more than 60 seconds (22% vs. 2.4%, p < 0.001). CBUs collected after DCC of more than 60 seconds had significantly lower TNC counts than those after DCC of less than 60 seconds (p < 0.0001). Furthermore, 38% to 46% of CBUs after DCC of more than 60 seconds had volume of less than 40 mL. Our study indicates that DCC of 30 to 60 seconds has a small negative impact on collection of high-TNC-count CBUs. However, increasing BTC to more than 60 seconds decreases significantly both TNC content and volume, reducing drastically the chances of obtaining clinically useful CBUs. © 2018 AABB.

a Borehole Seismic System for Active and Passive Seimsic Studies to 3 KM at Ptrc's Aquistore Project

Science.gov (United States)

Schmitt, D. R.; Nixon, C.; Kofman, R.; White, D. J.; Worth, K.

2015-12-01

We have constructed a downhole seismic recording system for application to depths of nearly 3 km and temperatures up to 135 °C at Aquistore, an independent research and monitoring project in which liquid CO2 is being stored in a brine and sandstone water formation. The key component to this system is a set of commercially available slim-hole 3-C sondes carrying 15 Hz geophones deployable in open and cased boreholes with diameters as small as 57 mm. The system is currently hosted on a 4-conductor wireline with digital information streamed to the surface recording unit. We have further incorporated these sondes into a mobile passive monitoring unit that includes a number of redundancies such as a multiple Tbyte network accessible RAID hard-drive system (NAS) and a self-designed uninterruptible power supply. The system can be remotely controlled via the internet. The system is currently deployed covering a range of depths from 2850 m to 2910 m. Ambient temperatures at this depth are approximately 110 °C with onboard tool temperatures running at 115 °C. Data is continuously streamed to the NAS for archiving, approximately 11 GBytes of data is recorded per day at the sampling period of 0.5 ms. The lack of noise at this depth allows short data snippets to be flagged with a simple amplitude threshold criteria. The greatly reduced data volume of the snippets allows for ready access via the internet to the system for ongoing quality control. Spurious events, mostly small amplitude tube waves originating at or near the surface, are readily discounted. Active seismic measurements are carried out simultaneously but these require that an appropriately accurate independent GPS based time synchronization be used. Various experiences with event detection, orientation of sondes using both explosives and seismic vibrator, potential overheating of the surface electronics, and issues related to loss of shore power provide for a detailed case study. Aquistore, managed by the

Correlation of open cell-attached and excised patch clamp techniques.

Science.gov (United States)

Filipovic, D; Hayslett, J P

1995-11-01

The excised patch clamp configuration provides a unique technique for some types of single channel analyses, but maintenance of stable, long-lasting preparations may be confounded by rundown and/or rapid loss of seal. Studies were performed on the amiloride-sensitive Na+ channel, located on the apical surface of A6 cells, to determine whether the nystatin-induced open cell-attached patch could serve as an alternative configuration. Compared to excised inside-out patches, stable preparations were achieved more readily with the open cell-attached patch (9% vs. 56% of attempts). In both preparations, the current voltage (I-V) relation was linear, current amplitudes were equal at opposite equivalent clamped voltages, and Erev was zero in symmetrical Na+ solutions, indicating similar Na+ activities on the cytosolic and external surfaces of the patch. Moreover, there was no evidence that nystatin altered channel activity in the patch because slope conductance (3-4pS) and Erev (75 mV), when the bath was perfused with a high K:low Na solution (ENa = 80 mV), were nearly equal in both patch configurations. Our results therefore indicate that the nystatin-induced open cell-attached patch can serve as an alternative approach to the excised inside-out patch when experiments require modulation of univalent ions in the cytosol.

Development and seismic evaluation of the seismic monitoring analysis system for HANARO

International Nuclear Information System (INIS)

Ryu, J. S.; Youn, D. B.; Kim, H. G.; Woo, J. S.

2003-01-01

Since the start of operation, the seismic monitoring system has been utilized for monitoring an earthquake at the HANARO site. The existing seismic monitoring system consists of field sensors and monitoring panel. The analog-type monitoring system with magnetic tape recorder is out-of-date model. In addition, the disadvantage of the existing system is that it does not include signal-analyzing equipment. Therefore, we have improved the analog seismic monitoring system except the field sensors into a new digital Seismic Monitoring Analysis System(SMAS) that can monitor and analyze earthquake signals. To achieve this objective for HANARO, the digital type hardware of the SMAS has been developed. The seismic monitoring and analysis programs that can provide rapid and precise information for an earthquake were developed. After the installation of the SMAS, we carried out the Site Acceptance Test (SAT) to confirm the functional capability of the newly developed system. The results of the SAT satisfy the requirements of the fabrication technical specifications. In addition, the seismic characteristics and structural integrity of the SMAS were evaluated. The results show that the cabinet of SMAS can withstand the effects of seismic loads and remain functional. This new SMAS is operating in the HANARO instrument room to acquire and analyze the signal of an earthquake

A seismic design of nuclear reactor building structures applying seismic isolation system in a seismicity region-a feasibility case study in Japan

Energy Technology Data Exchange (ETDEWEB)

Kubo, Tetsuo [The University of Tokyo, Tokyo (Japan); Yamamoto, Tomofumi; Sato, Kunihiko [Mitsubishi Heavy Industries, Ltd., Kobe (Japan); Jimbo, Masakazu [Toshiba Corporation, Yokohama (Japan); Imaoka, Tetsuo [Hitachi-GE Nuclear Energy, Ltd., Hitachi (Japan); Umeki, Yoshito [Chubu Electric Power Co. Inc., Nagoya (Japan)

2014-10-15

A feasibility study on the seismic design of nuclear reactor buildings with application of a seismic isolation system is introduced. After the Hyogo-ken Nanbu earthquake in Japan of 1995, seismic isolation technologies have been widely employed for commercial buildings. Having become a mature technology, seismic isolation systems can be applied to NPP facilities in areas of high seismicity. Two reactor buildings are discussed, representing the PWR and BWR buildings in Japan, and the application of seismic isolation systems is discussed. The isolation system employing rubber bearings with a lead plug positioned (LRB) is examined. Through a series of seismic response analyses using the so-named standard design earthquake motions covering the design basis earthquake motions obtained for NPP sites in Japan, the responses of the seismic isolated reactor buildings are evaluated. It is revealed that for the building structures examined herein: (1) the responses of both isolated buildings and isolating LRBs fulfill the specified design criteria; (2) the responses obtained for the isolating LRBs first reach the ultimate condition when intensity of motion is 2.0 to 2.5 times as large as that of the design-basis; and (3) the responses of isolated reactor building fall below the range of the prescribed criteria.

Seismic hazard assessment: Issues and alternatives

Science.gov (United States)

Wang, Z.

2011-01-01

Seismic hazard and risk are two very important concepts in engineering design and other policy considerations. Although seismic hazard and risk have often been used inter-changeably, they are fundamentally different. Furthermore, seismic risk is more important in engineering design and other policy considerations. Seismic hazard assessment is an effort by earth scientists to quantify seismic hazard and its associated uncertainty in time and space and to provide seismic hazard estimates for seismic risk assessment and other applications. Although seismic hazard assessment is more a scientific issue, it deserves special attention because of its significant implication to society. Two approaches, probabilistic seismic hazard analysis (PSHA) and deterministic seismic hazard analysis (DSHA), are commonly used for seismic hazard assessment. Although PSHA has been pro-claimed as the best approach for seismic hazard assessment, it is scientifically flawed (i.e., the physics and mathematics that PSHA is based on are not valid). Use of PSHA could lead to either unsafe or overly conservative engineering design or public policy, each of which has dire consequences to society. On the other hand, DSHA is a viable approach for seismic hazard assessment even though it has been labeled as unreliable. The biggest drawback of DSHA is that the temporal characteristics (i.e., earthquake frequency of occurrence and the associated uncertainty) are often neglected. An alternative, seismic hazard analysis (SHA), utilizes earthquake science and statistics directly and provides a seismic hazard estimate that can be readily used for seismic risk assessment and other applications. ?? 2010 Springer Basel AG.

Seismic and Geodetic Monitoring of the Nicoya, Costa Rica, Seismic Gap

Science.gov (United States)

Protti, M.; Gonzalez, V.; Schwartz, S.; Dixon, T.; Kato, T.; Kaneda, Y.; Simila, G.; Sampson, D.

2007-05-01

The Nicoya segment of the Middle America Trench has been recognized as a mature seismic gap with potential to generate a large earthquake in the near future (it ruptured with large earthquakes in 1853, 1900 and 1950). Low level of background seismicity and fast crustal deformation of the forearc are indicatives of strong coupling along the plate interface. Given its high seismic potential, the available data and especially the fact that the Nicoya peninsula extends over large part of the rupture area, this gap was selected as one of the two sites for a MARGINS-SEIZE experiment. With the goal of documenting the evolution of loading and stress release along this seismic gap, an international effort involving several institutions from Costa Rica, the United States and Japan is being carried out for over a decade in the region. This effort involves the installation of temporary and permanent seismic and geodetic networks. The seismic network includes short period, broad band and strong motion instruments. The seismic monitoring has provided valuable information on the geometry and characteristics of the plate interface. The geodetic network includes temporary and permanent GPS stations as well as surface and borehole tiltmeters. The geodetic networks have helped quantify the extend and degree of coupling. A continuously recording, three- station GPS network on the Nicoya Peninsula, Costa Rica, recorded what we believe is the first slow slip event observed along the plate interface of the Costa Rica subduction zone. We will present results from these monitoring networks. Collaborative international efforts are focused on expanding these seismic and geodetic networks to provide improved resolution of future creep events, to enhanced understanding of the mechanical behavior of the Nicoya subduction segment of the Middle American Trench and possibly capture the next large earthquake and its potential precursor deformation.

Seismic Structure of Perth Basin (Australia) and surroundings from Passive Seismic Deployments

Science.gov (United States)

Issa, N.; Saygin, E.; Lumley, D. E.; Hoskin, T. E.

2016-12-01

We image the subsurface structure of Perth Basin, Western Australia and surroundings by using ambient seismic noise data from 14 seismic stations recently deployed by University of Western Australia (UWA) and other available permanent stations from Geoscience Australia seismic network and the Australian Seismometers in Schools program. Each of these 14 UWA seismic stations comprises a broadband sensor and a high fidelity 3-component 10 Hz geophone, recording in tandem at 250 Hz and 1000 Hz. The other stations used in this study are equipped with short period and broadband sensors. In addition, one shallow borehole station is operated with eight 3 component geophones at depths of between 2 and 44 m. The network is deployed to characterize natural seismicity in the basin and to try and identify any microseismic activity across Darling Fault Zone (DFZ), bounding the basin to the east. The DFZ stretches to approximately 1000 km north-south in Western Australia, and is one of the longest fault zones on the earth with a limited number of detected earthquakes. We use seismic noise cross- and auto-correlation methods to map seismic velocity perturbations across the basin and the transition from DFZ to the basin. Retrieved Green's functions are stable and show clear dispersed waveforms. Travel times of the surface wave Green's functions from noise cross-correlations are inverted with a two-step probabilistic framework to map the absolute shear wave velocities as a function of depth. The single station auto-correlations from the seismic noise yields P wave reflectivity under each station, marking the major discontinuities. Resulting images show the shear velocity perturbations across the region. We also quantify the variation of ambient seismic noise at different depths in the near surface using the geophones in the shallow borehole array.

Negligible substrate clamping effect on piezoelectric response in (111)-epitaxial tetragonal Pb(Zr, Ti)O{sub 3} films

Energy Technology Data Exchange (ETDEWEB)

Yamada, Tomoaki, E-mail: t-yamada@nucl.nagoya-u.ac.jp [Department of Materials, Physics and Energy Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan); Yasumoto, Jun; Ito, Daisuke; Yoshino, Masahito; Nagasaki, Takanori [Department of Materials, Physics and Energy Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Sakata, Osami [Synchrotron X-ray Station at SPring-8 and Synchrotron X-ray Group, National Institute for Materials Science, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Department of Innovative and Engineered Material, Tokyo Institute of Technology, Yokohama 226-8503 (Japan); Imai, Yasuhiko [Japan Synchrotron Radiation Research Institute, SPring-8, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Kiguchi, Takanori [Institute for Materials Research, Tohoku University, Sendai, Miyagi 980-8577 (Japan); Shiraishi, Takahisa; Shimizu, Takao; Funakubo, Hiroshi [Department of Innovative and Engineered Material, Tokyo Institute of Technology, Yokohama 226-8503 (Japan)

2015-08-21

The converse piezoelectric responses of (111)- and (001)-epitaxial tetragonal Pb(Zr{sub 0.35}Ti{sub 0.65})O{sub 3} [PZT] films were compared to investigate the orientation dependence of the substrate clamping effect. Synchrotron X-ray diffraction (XRD) and piezoelectric force microscopy revealed that the as-grown (111)-PZT film has a polydomain structure with normal twin boundaries that are changed by the poling process to inclined boundaries, as predicted by Romanov et al. [Phys. Status Solidi A 172, 225 (1999)]. Time-resolved synchrotron XRD under bias voltage showed the negligible impact of substrate clamping on the piezoelectric response in the (111)-PZT film, unlike the case for (001)-PZT film. The origin of the negligible clamping effect in the (111)-PZT film is discussed from the viewpoint of the elastic properties and the compensation of lattice distortion between neighboring domains.

Apparatus for deploying and energizing submersible electric motor downhole

International Nuclear Information System (INIS)

Conner, S.E.; Dwiggins, J.L.; Brookbank, E.B.

1991-01-01

This patent describes an apparatus for deploying and energizing a submergible electric motor downhole. It comprises a cable socket assembly and a cable connecting-and-sealing chamber assembly adapted to be arranged seriatim in the path of cable means and the motor, the assemblies having first and second housings, respectively, means for connecting a lower end of the first housing to an upper end of the second housing, a lower end of the second housing being adapted for connection to the motor, the cable socket assembly having an attachment portion including means for attaching a weight-bearing cable of the cable means to the first housing via a breakaway connection, the first housing having a passage therein adapted to pass an electrical cable of the cable means to the second housing, the second housing being divided by a body therein into first and second chambers sealed from each other, the first chamber being adapted to communicate sealingly with the passage and the second chamber being adapted to communicate sealingly with the interior of the motor, a first set of electrical conductors in the first chamber and a second set of electrical conductors in the second chamber, the body having feed-through means for electrically interconnecting conductors of the first set with corresponding conductors of the second set, the conductors of the first set having electrical connector parts adapted to connect releasably with corresponding electrical connector parts of the electrical cable, and the conductors of the second set having electrical connector parts adapted to connect with corresponding electrical connector parts of the motor, each of the chambers being adapted to be filled with fluid to exclude well fluid therefrom

Quantitative analysis of dual whole-cell voltage-clamp determination of gap junctional conductance

NARCIS (Netherlands)

van Rijen, H. V.; Wilders, R.; van Ginneken, A. C.; Jongsma, H. J.

1998-01-01

The dual whole-cell voltage-clamp technique is used widely for determination of kinetics and conductance of gap junctions. The use of this technique may, however, occasion to considerable errors. We have analysed the errors in steady state junctional conductance measurements under different

Co-ordinated research programme on benchmark study for the seismic analysis and testing of WWER-type nuclear power plants. V. 2B. General material: codes, standards, criteria. Working material

International Nuclear Information System (INIS)

1999-01-01

In August 1991, following the SMiRT-11 Conference in Tokyo, a Technical Committee Meeting was held on the 'Seismic safety issues relating to existing NPPs'. The Proceedings of this TCM was subsequently compiled in an IAEA Working Material. One of the main recommendations of this TCM, called for the harmonization of criteria and methods used in Member States in seismic reassessment and upgrading of existing NPPs. Twenty four institutions from thirteen countries participated in the CRP named 'Benchmark study for the seismic analysis and testing of WWER type NPPs'. Two types of WWER reactors (WWER-1000 and WWER-440/213) selected for benchmarking. Kozloduy NPP Units 5/6 and Paks NPP represented these respectively as prototypes. Consistent with the recommendations of the TCM and the working paper prepared by the subsequent Consultants' Meeting, the focal activity of the CRP was the benchmarking exercises. A similar methodology was followed both for Paks NPP and Kozloduy NPP Unit 5. Firstly, the NPP (mainly the reactor building) was tested using a blast loading generated by a series of explosions from buried TNT charges. Records from this test were obtained at several free field locations (both downhole and surface), foundation mat, various elevations of structures as well as some tanks and the stack. Then the benchmark participants were provided with structural drawings, soil data and the free field record of the blast experiment. Their task was to make a blind prediction of the response at preselected locations. The analytical results from these participants were then compared with the results from the test. Although the benchmarking exercises constituted the focus of the CRP, there were many other interesting problems related to the seismic safety of WWER type NPPs which were addressed by the participants. These involved generic studies, i.e. codes and standards used in original WWER designs and their comparison with current international practice; seismic analysis

New seismic source `BLASTER` for seismic survey; Hasaiyaku wo shingen to shite mochiita danseiha tansa

Energy Technology Data Exchange (ETDEWEB)

Koike, G; Yoshikuni, Y [OYO Corp., Tokyo (Japan)

1996-10-01

Built-up weight and vacuole have been conceived as seismic sources without using explosive. There have been problems that they have smaller energy to generate elastic wave than explosive, and that they have inferior working performance. Concrete crushing explosive is tried to use as a new seismic source. It is considered to possess rather large seismic generating energy, and it is easy to handle from the viewpoint of safety. Performance as seismic source and applicability to exploration works of this crushing explosive were compared with four kinds of seismic sources using dynamite, dropping weight, shot-pipe utilizing shot vacuole, and impact by wooden maul. When considered by the velocity amplitude, the seismic generating energy of the crushing explosive of 120 g is about one-fifth of dynamite of 100 g. Elastic wave generated includes less high frequency component than that by dynamite, and similar to that using seismic source without explosive, such as the weight dropping. The maximum seismic receiving distance obtained by the seismic generation was about 100 m. This was effective for the slope survey with the exploration depth between 20 m and 30 m. 1 ref., 9 figs., 2 tabs.

Seismic rupture modelling, strong motion prediction and seismic hazard assessment: fundamental and applied approaches

International Nuclear Information System (INIS)

Berge-Thierry, C.

2007-05-01

The defence to obtain the 'Habilitation a Diriger des Recherches' is a synthesis of the research work performed since the end of my Ph D. thesis in 1997. This synthesis covers the two years as post doctoral researcher at the Bureau d'Evaluation des Risques Sismiques at the Institut de Protection (BERSSIN), and the seven consecutive years as seismologist and head of the BERSSIN team. This work and the research project are presented in the framework of the seismic risk topic, and particularly with respect to the seismic hazard assessment. Seismic risk combines seismic hazard and vulnerability. Vulnerability combines the strength of building structures and the human and economical consequences in case of structural failure. Seismic hazard is usually defined in terms of plausible seismic motion (soil acceleration or velocity) in a site for a given time period. Either for the regulatory context or the structural specificity (conventional structure or high risk construction), seismic hazard assessment needs: to identify and locate the seismic sources (zones or faults), to characterize their activity, to evaluate the seismic motion to which the structure has to resist (including the site effects). I specialized in the field of numerical strong-motion prediction using high frequency seismic sources modelling and forming part of the IRSN allowed me to rapidly working on the different tasks of seismic hazard assessment. Thanks to the expertise practice and the participation to the regulation evolution (nuclear power plants, conventional and chemical structures), I have been able to work on empirical strong-motion prediction, including site effects. Specific questions related to the interface between seismologists and structural engineers are also presented, especially the quantification of uncertainties. This is part of the research work initiated to improve the selection of the input ground motion in designing or verifying the stability of structures. (author)

J-integral analysis of heterogeneous mismatched girth welds in clamped single-edge notched tension specimens

International Nuclear Information System (INIS)

Hertelé, Stijn; De Waele, Wim; Verstraete, Matthias; Denys, Rudi; O'Dowd, Noel

2014-01-01

Flaw assessment procedures require a quantification of crack driving force, and such procedures are generally based on the assumption of weld homogeneity. However, welds generally have a heterogeneous microstructure, which will influence the crack driving force. This paper describes a stress-based methodology to assess complex heterogeneous welds using a J-based approach. Clamped single-edge notched tension specimens, representative of girth weld flaws, are analyzed and the influence of weld heterogeneity on crack driving force has been determined. The use of a modified limit load for heterogeneous welds is proposed, suitable for implementation in a ‘homogenized’ J-integral estimation scheme. It follows from an explicit modification of an existing solution for centre cracked tension specimens. The proposed solution provides a good estimate of crack driving force and any errors in the approximation may be accounted for by means of a small safety factor on load bearing capacity. - Highlights: • We present a crack driving force estimation procedure for heterogeneous welds. • The procedure is based on a ‘homogenized’ version of the EPRI equation. • Complex welds are translated into equivalent idealized mismatched welds. • The procedure is validated for clamped SE(T) specimens. • A mismatch limit load for clamped SE(T) specimens is developed

Seismic and tsunami safety margin assessment

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-08-15

Nuclear Regulation Authority is going to establish new seismic and tsunami safety guidelines to increase the safety of NPPs. The main purpose of this research is testing structures/components important to safety and tsunami resistant structures/components, and evaluating the capacity of them against earthquake and tsunami. Those capacity data will be utilized for the seismic and tsunami back-fit review based on the new seismic and tsunami safety guidelines. The summary of the program in 2012 is as follows. 1. Component seismic capacity test and quantitative seismic capacity evaluation. PWR emergency diesel generator partial-model seismic capacity tests have been conducted and quantitative seismic capacities have been evaluated. 2. Seismic capacity evaluation of switching-station electric equipment. Existing seismic test data investigation, specification survey and seismic response analyses have been conducted. 3. Tsunami capacity evaluation of anti-inundation measure facilities. Tsunami pressure test have been conducted utilizing a small breakwater model and evaluated basic characteristics of tsunami pressure against seawall structure. (author)

Seismic and tsunami safety margin assessment

International Nuclear Information System (INIS)

2013-01-01

Nuclear Regulation Authority is going to establish new seismic and tsunami safety guidelines to increase the safety of NPPs. The main purpose of this research is testing structures/components important to safety and tsunami resistant structures/components, and evaluating the capacity of them against earthquake and tsunami. Those capacity data will be utilized for the seismic and tsunami back-fit review based on the new seismic and tsunami safety guidelines. The summary of the program in 2012 is as follows. 1. Component seismic capacity test and quantitative seismic capacity evaluation. PWR emergency diesel generator partial-model seismic capacity tests have been conducted and quantitative seismic capacities have been evaluated. 2. Seismic capacity evaluation of switching-station electric equipment. Existing seismic test data investigation, specification survey and seismic response analyses have been conducted. 3. Tsunami capacity evaluation of anti-inundation measure facilities. Tsunami pressure test have been conducted utilizing a small breakwater model and evaluated basic characteristics of tsunami pressure against seawall structure. (author)

Five-Level Z-Source Neutral Point-Clamped Inverter

DEFF Research Database (Denmark)

Gao, F.; Loh, P.C.; Blaabjerg, Frede

2007-01-01

This paper proposes a five-level Z-source neutralpoint- clamped (NPC) inverter with two Z-source networks functioning as intermediate energy storages coupled between dc sources and NPC inverter circuitry. Analyzing the operational principles of Z-source network with partial dclink shoot......-through scheme reveals the hidden theories in the five-level Z-source NPC inverter unlike the operational principle appeared in the general two-level Z-source inverter, so that the five-level Z-source NPC inverter can be designed with the modulation of carrier-based phase disposition (PD) or alternative phase...

Seismic Consequence Abstraction

International Nuclear Information System (INIS)

Gross, M.

2004-01-01

The primary purpose of this model report is to develop abstractions for the response of engineered barrier system (EBS) components to seismic hazards at a geologic repository at Yucca Mountain, Nevada, and to define the methodology for using these abstractions in a seismic scenario class for the Total System Performance Assessment - License Application (TSPA-LA). A secondary purpose of this model report is to provide information for criticality studies related to seismic hazards. The seismic hazards addressed herein are vibratory ground motion, fault displacement, and rockfall due to ground motion. The EBS components are the drip shield, the waste package, and the fuel cladding. The requirements for development of the abstractions and the associated algorithms for the seismic scenario class are defined in ''Technical Work Plan For: Regulatory Integration Modeling of Drift Degradation, Waste Package and Drip Shield Vibratory Motion and Seismic Consequences'' (BSC 2004 [DIRS 171520]). The development of these abstractions will provide a more complete representation of flow into and transport from the EBS under disruptive events. The results from this development will also address portions of integrated subissue ENG2, Mechanical Disruption of Engineered Barriers, including the acceptance criteria for this subissue defined in Section 2.2.1.3.2.3 of the ''Yucca Mountain Review Plan, Final Report'' (NRC 2003 [DIRS 163274])

Seismic Consequence Abstraction

Energy Technology Data Exchange (ETDEWEB)

M. Gross

2004-10-25

The primary purpose of this model report is to develop abstractions for the response of engineered barrier system (EBS) components to seismic hazards at a geologic repository at Yucca Mountain, Nevada, and to define the methodology for using these abstractions in a seismic scenario class for the Total System Performance Assessment - License Application (TSPA-LA). A secondary purpose of this model report is to provide information for criticality studies related to seismic hazards. The seismic hazards addressed herein are vibratory ground motion, fault displacement, and rockfall due to ground motion. The EBS components are the drip shield, the waste package, and the fuel cladding. The requirements for development of the abstractions and the associated algorithms for the seismic scenario class are defined in ''Technical Work Plan For: Regulatory Integration Modeling of Drift Degradation, Waste Package and Drip Shield Vibratory Motion and Seismic Consequences'' (BSC 2004 [DIRS 171520]). The development of these abstractions will provide a more complete representation of flow into and transport from the EBS under disruptive events. The results from this development will also address portions of integrated subissue ENG2, Mechanical Disruption of Engineered Barriers, including the acceptance criteria for this subissue defined in Section 2.2.1.3.2.3 of the ''Yucca Mountain Review Plan, Final Report'' (NRC 2003 [DIRS 163274]).

Co-seismic slip, post-seismic slip, and largest aftershock associated with the 1994 Sanriku-haruka-oki, Japan, earthquake

Science.gov (United States)

Yagi, Yuji; Kikuchi, Masayuki; Nishimura, Takuya

2003-11-01

We analyzed continuous GPS data to investigate the spatio-temporal distribution of co-seismic slip, post-seismic slip, and largest aftershock associated with the 1994 Sanriku-haruka-oki, Japan, earthquake (Mw = 7.7). To get better resolution for co-seismic and post-seismic slip distribution, we imposed a weak constraint as a priori information of the co-seismic slip determined by seismic wave analyses. We found that the post-seismic slip during 100 days following the main-shock amount to as much moment release as the main-shock, and that the sites of co-seismic slip and post-seismic slip are partitioning on a plate boundary region in complimentary fashion. The major post-seismic slip was triggered by the mainshock in western side of the co-seismic slip, and the extent of the post-seismic slip is almost unchanged with time. It rapidly developed a shear stress concentration ahead of the slip area, and triggered the largest aftershock.

Risk based seismic design criteria

International Nuclear Information System (INIS)

Kennedy, R.P.

1999-01-01

In order to develop a risk based seismic design criteria the following four issues must be addressed: (1) What target annual probability of seismic induced unacceptable performance is acceptable? (2) What minimum seismic margin is acceptable? (3) Given the decisions made under Issues 1 and 2, at what annual frequency of exceedance should the safe-shutdown-earthquake (SSE) ground motion be defined? (4) What seismic design criteria should be established to reasonably achieve the seismic margin defined under Issue 2? The first issue is purely a policy decision and is not addressed in this paper. Each of the other three issues are addressed. Issues 2 and 3 are integrally tied together so that a very large number of possible combinations of responses to these two issues can be used to achieve the target goal defined under Issue 1. Section 2 lays out a combined approach to these two issues and presents three potentially attractive combined resolutions of these two issues which reasonably achieves the target goal. The remainder of the paper discusses an approach which can be used to develop seismic design criteria aimed at achieving the desired seismic margin defined in resolution of Issue 2. Suggestions for revising existing seismic design criteria to more consistently achieve the desired seismic margin are presented. (orig.)

Feasibility evaluation of downhole oil/water separator (DOWS) technology.

Energy Technology Data Exchange (ETDEWEB)

Veil, J. A.; Langhus, B. G.; Belieu, S.

1999-01-31

The largest volume waste stream associated with oil and gas production is produced water. A survey conducted by the American Petroleum Institute estimated that 20.9 billion barrels of produced water were disposed of in 1985 (Wakim 1987). Of this total, 91% was disposed of through disposal wells or was injected for enhanced oil recovery projects. Treatment and disposal of produced water represents a significant cost for operators. A relatively new technology, downhole oil/water separators (DOWS), has been developed to reduce the cost of handling produced water. DOWS separate oil and gas from produced water at the bottom of the well and reinject some of the produced water into another formation or another horizon within the same formation, while the oil and gas are pumped to the surface. Since much of the produced water is not pumped to the surface, treated, and pumped from the surface back into a deep formation, the cost of handling produced water is greatly reduced. When DOWS are used, additional oil may be recovered as well. In cases where surface processing or disposal capacity is a limiting factor for further production within a field, the use of DOWS to dispose of some of the produced water can allow additional production within that field. Simultaneous injection using DOWS minimizes the opportunity for contamination of underground sources of drinking water (USDWs) through leaks in tubing and casing during the injection process. This report uses the acronym 'DOWS' although the technology may also be referred to as DHOWS or as dual injection and lifting systems (DIALS). Simultaneous injection using DOWS has the potential to profoundly influence the domestic oil industry. The technology has been shown to work in limited oil field applications in the United States and Canada. Several technical papers describing DOWS have been presented at oil and gas industry conferences, but for the most part, the information on the DOWS technology has not been widely

Rotation-Enabled 7-Degree of Freedom Seismometer for Geothermal Resource Development. Phase 1 Final Report

Energy Technology Data Exchange (ETDEWEB)

Pierson, Bob [Applied Technology Associates, Albuquerque, NM (United States); Laughlin, Darren [Applied Technology Associates, Albuquerque, NM (United States)

2013-10-29

, and confidence, thus removing some current blocks to feasibility and significantly increasing access to potential geothermal sites. During the Phase 1 effort summarized in this final report, the ATA Team modeled and built two TRL 3 proof-of-concept test units for two competing rotational sensor technologies. The two competing technologies were based on ATA's angular rate and angular displacement measurement technologies; Angular rate: ATA's Magnetohydrodynamic Angular Rate Sensor (Seismic MHD); and Angular displacement: ATA's Low Frequency Improved Torsional Seismometer (LFITS). In order to down-select between these two technologies and formulate a go / no go decision, the ATA Team analyzed and traded scientific performance requirements and market constraints against sensor characteristics and components, acquiring field data where possible to validate the approach and publishing results from these studies of rotational technology capability. Based on the results of Phase 1, the ATA Team finds that the Seismic MHD (SMHD) technology is the best choice for enabling rotational seismometry and significant technical potential exists for micro-seismic monitoring using a downhole 7-DOF device based on the SMHD. Recent technical papers and field data confirm the potential of rotational sensing for seismic mapping, increasing confidence that cost-reduction benefits are achievable for EGS. However, the market for geothermal rotational sensing is small and undeveloped. As a result, this report recommends modifying the Phase 2 plan to focus on prototype development aimed at partnering with early adopters within the geothermal industry and the scientific research community. The highest public benefit will come from development and deployment of a science-grade SMHD rotational seismometer engineered for geothermal downhole conditions and an integrated test tool for downhole measurements at active geothermal test sites.

Enhancement of seismic resistance of buildings

Directory of Open Access Journals (Sweden)

Claudiu-Sorin Dragomir

2014-03-01

Full Text Available The objectives of the paper are both seismic instrumentation for damage assessment and enhancing of seismic resistance of buildings. In according with seismic design codes in force the buildings are designed to resist at seismic actions. Due to the time evolution of these design provisions, there are buildings that were designed decades ago, under the less stringent provisions. The conceptual conformation is nowadays provided in all Codes of seismic design. According to the Code of seismic design P100-1:2006 the asymmetric structures do not have an appropriate seismic configuration; they have disadvantageous distribution of volumes, mass and stiffness. Using results of temporary seismic instrumentation the safety condition of the building may be assessed in different phases of work. Based on this method, the strengthening solutions may be identified and the need of seismic joints may be emphasised. All the aforementioned ideas are illustrated through a case study. Therefore it will be analysed the dynamic parameter evolution of an educational building obtained in different periods. Also, structural intervention scenarios to enhance seismic resistance will be presented.

FY 1998 report on the verification survey of geothermal survey technology, etc./Development of the reservoir fluctuation survey method (Summary). Theme 5-1. Technology to predict reservoir fluctuations; 1998 nendo chinetsu tansa gijutsu nado kensho chosa choryuso hendo tanhsaho kaihatsu hokokusho (yoyaku ). 5-1. Choryuso hendo (choryuso hendo yooku gijutsu)

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

The existing gravity post processor was improved and a feasibility study of downhole gravity profile measurement was conducted. As compared with the earth surface, great fluctuations could be observed in the downhole, indicating a possibility of acquiring the useful information on underground steam zones. The existing self-potential post processor was improved, which made the history matching analysis easy. A geochemical post processor was developed which can analyze geochemical fluctuations. Changes in resistivity in reservoir associated with production/injection of geothermal fluids were calculated, and a feasibility was shown of developing the resistivity post processor into which the existing MT forward calculation method was efficiently integrated. From the data on effects of changes in temperature/fluid phase on seismic wave velocity and damping, usability of the seismic wave post processor was made clear. From the reservoir fluctuation analysis using gravity/self-potential post processor, it was found out that gravity fluctuations at Onikobe had already finished and presently there are less fluctuations. Self-potential is still in fluctuations and becomes indices of reservoir fluctuations. Study was made also on Sumikawa where steam is dominant. (NEDO)

Method and apparatus for determining the spontaneous earth potential log from downhole gradient measurements

International Nuclear Information System (INIS)

Maciejewski, W. J.

1985-01-01

A method and apparatus for measuring the differential or gradient of an earth variable within a well bore (e.g., the spontaneous earth potential) and producing improved logs of this gradient or differential and its integral variable essentially free of any accumulated instrument and base line drift or error. The differential spontaneous potential of an earth formation traversed by a well bore is measured at repeated multiple depths by moving a pair of closely spaced electrodes through the well bore wherein each electrode is electrically insulated externally from the other and from a third downhole local ground (such as the well tool cable) to which each is internally resistively referenced. The measured electrical potential across the closely spaced electrodes is amplified and digitized before being transmitted to the earth's surface, whereupon an averaged value of such differential measurements within a traveling data window of predetermined length and adjacent to each successive measurement is used to adjust for base line drift, noise and instrument induced error. The resulting compensated differential logs are integrated, resulting in spontaneous potential logs of improved character

Gasket-holder to put in place gaskets for connection of pipes with clamp fittings

International Nuclear Information System (INIS)

Fiori, R.

1989-01-01

Gasket-holder comprising 2 arms with tongues holding the gasket and fixing devices on a pipe clamp fitting and centering means. Application is made to fit circular gaskets on pipe with conic end in adverse environment [fr

Seismic risk map for Southeastern Brazil

International Nuclear Information System (INIS)

Mioto, J.A.

1984-01-01

During the last few years, some studies regarding seismic risk were prepared for three regions of Brazil. They were carried on account of two basic interests: first, toward the seismic history and recurrence of Brazilian seismic events; second, in a way as to provide seismic parameters for the design and construction of hydro and nuclear power plants. The first seismic risk map prepared for the southeastern region was elaborated in 1979 by 6he Universidade de Brasilia (UnB-Brasilia Seismological Station). In 1981 another seismic risk map was completed on the basis of seismotectonic studies carried out for the design and construction of the Nuclear power plants of Itaorna Beach (Angra dos Reis, Rio de Janeiro) by IPT (Mining and Applied Geology Division). In Brazil, until 1984, seismic studies concerning hydro and nuclear power plants and other civil construction of larger size did not take into account the seismic events from the point of view of probabilities of seismic recurrences. Such analysis in design is more important than the choice of a level of intensity or magnitude, or adoption of a seismicity level ased on deterministic methods. In this way, some considerations were made, concerning the use of seisms in Brazilian designs of hydro and nuclear power plants, as far as seismic analysis is concerned, recently altered over the current seismic risk panorama. (D.J.M.) [pt

Seismic retrofitting of Apsara reactor building

International Nuclear Information System (INIS)

Reddy, G.R.; Parulekar, Y.M.; Sharma, A.; Rao, K.N.; Narasimhan, Rajiv; Srinivas, K.; Basha, S.M.; Thomas, V.S.; Soma Kumar, K.

2006-01-01

Seismic analysis of Apsara Reactor building was carried out and was found not meeting the current seismic requirements. Due to the building not qualifying for seismic loads, a retrofit scheme using elasto-plastic dampers is proposed. Following activities have been performed in this direction: Carried out detailed seismic analysis of Apsara reactor building structure incorporating proposed seismic retrofit. Demonstrating the capability of the retrofitted structure to with stand the earth quake level for Trombay site as per the current standards by analysis and by model studies. Implementation of seismic retrofit program. This paper presents the details of above aspects related to Seismic analysis and retrofitting of Apsara reactor building. (author)

Co-ordinated research programme on benchmark study for the seismic analysis and testing of WWER-type nuclear power plants. V. 3I. Kozloduy NPP units 5/6: Analysis and testing. Working material

International Nuclear Information System (INIS)

1999-01-01

In August 1991, following the SMiRT-11 Conference in Tokyo, a Technical Committee Meeting was held on the 'Seismic safety issues relating to existing NPPs'. The Proceedings of this TCM was subsequently compiled in an IAEA Working Material. One of the main recommendations of this TCM, called for the harmonization of criteria and methods used in Member States in seismic reassessment and upgrading of existing NPPs. Twenty four institutions from thirteen countries participated in the CRP named 'Benchmark study for the seismic analysis and testing of WWER type NPPs'. Two types of WWER reactors (WWER-1000 and WWER-440/213) selected for benchmarking. Kozloduy NPP Units 5/6 and Paks NPP represented these respectively as prototypes. Consistent with the recommendations of the TCM and the working paper prepared by the subsequent Consultants' Meeting, the focal activity of the CRP was the benchmarking exercises. A similar methodology was followed both for Paks NPP and Kozloduy NPP Unit 5. Firstly, the NPP (mainly the reactor building) was tested using a blast loading generated by a series of explosions from buried TNT charges. Records from this test were obtained at several free field locations (both downhole and surface), foundation mat, various elevations of structures as well as some tanks and the stack. Then the benchmark participants were provided with structural drawings, soil data and the free field record of the blast experiment. Their task was to make a blind prediction of the response at preselected locations. The analytical results from these participants were then compared with the results from the test. Although the benchmarking exercises constituted the focus of the CRP, there were many other interesting problems related to the seismic safety of WWER type NPPs which were addressed by the participants. These involved generic studies, i.e. codes and standards used in original WWER designs and their comparison with current international practice; seismic analysis

Production induced subsidence and seismicity in the Groningen gas field - can it be managed?

Science.gov (United States)

de Waal, J. A.; Muntendam-Bos, A. G.; Roest, J. P. A.

2015-11-01

centre of the field on subsidence and seismicity will be studied in detail in an effort to improve understanding and thereby reduce prediction uncertainties. First indications are that the reduction has led to a drop in subsidence rate and seismicity within a period of a few months. This suggests that the system can be controlled and regulated. If this is the case, the integrated loop of predicting, monitoring and updating in combination with mitigation measures can be applied to keep subsidence (rate) and induced seismicity within limits. To be able to do so, the operator has extended the field-monitoring network. It now includes PS-InSAR and GPS stations for semi-permanent subsidence monitoring in addition to a traditional network of levelling benchmarks. For the seismic monitoring 60 shallow (200 m) borehole seismometers, 60 + accelerometers and two permanent downhole seismic arrays at reservoir level will be added. Scenario's spanning the range of parameter and model uncertainties will be generated to calculate possible subsidence and seismicity outcomes. The probability of each scenario will be updated over time through confrontation with the measurements as they become available. At regular intervals the subsidence prediction and the seismic risk will be re-evaluated. Further mitigation measures, possibly including further production measures will need to be taken if probabilities indicate unacceptable risks.

Seismic fragility analyses

International Nuclear Information System (INIS)

Kostov, Marin

2000-01-01

In the last two decades there is increasing number of probabilistic seismic risk assessments performed. The basic ideas of the procedure for performing a Probabilistic Safety Analysis (PSA) of critical structures (NUREG/CR-2300, 1983) could be used also for normal industrial and residential buildings, dams or other structures. The general formulation of the risk assessment procedure applied in this investigation is presented in Franzini, et al., 1984. The probability of failure of a structure for an expected lifetime (for example 50 years) can be obtained from the annual frequency of failure, β E determined by the relation: β E ∫[d[β(x)]/dx]P(flx)dx. β(x) is the annual frequency of exceedance of load level x (for example, the variable x may be peak ground acceleration), P(fI x) is the conditional probability of structure failure at a given seismic load level x. The problem leads to the assessment of the seismic hazard β(x) and the fragility P(fl x). The seismic hazard curves are obtained by the probabilistic seismic hazard analysis. The fragility curves are obtained after the response of the structure is defined as probabilistic and its capacity and the associated uncertainties are assessed. Finally the fragility curves are combined with the seismic loading to estimate the frequency of failure for each critical scenario. The frequency of failure due to seismic event is presented by the scenario with the highest frequency. The tools usually applied for probabilistic safety analyses of critical structures could relatively easily be adopted to ordinary structures. The key problems are the seismic hazard definitions and the fragility analyses. The fragility could be derived either based on scaling procedures or on the base of generation. Both approaches have been presented in the paper. After the seismic risk (in terms of failure probability) is assessed there are several approaches for risk reduction. Generally the methods could be classified in two groups. The

Timing of umbilical cord clamping among infants born at 22 through 27 weeks' gestation.

Science.gov (United States)

Backes, C H; Huang, H; Iams, J D; Bauer, J A; Giannone, P J

2016-01-01

To investigate the safety, feasibility and efficacy of delayed cord clamping (DCC) compared with immediate cord clamping (ICC) at delivery among infants born at 22 to 27 weeks' gestation. This was a pilot, randomized, controlled trial in which women in labor with singleton pregnancies at 22 to 27 weeks' gestation were randomly assigned to ICC (cord clamped at 5 to 10 s) or DCC (30 to 45 s). Forty mother-infant pairs were randomized. Infants in the ICC and DCC groups had mean gestational ages (GA) of 24.6 and 24.4 weeks, respectively. No differences were observed between the groups across all available safety measures, although infants in the DCC group had higher admission temperatures than infants in the ICC group (97.4 vs. 96.2 °F, P=0.04). During the first 24 h of life, blood pressures were lower in the ICC group than in the DCC group (P<0.05), despite a threefold greater incidence of treatment for hypotension (45% vs. 12%, P<0.01). Infants in the ICC group had increased numbers of red blood transfusions (in first 28 days of life) than infants in DCC group (4.1±3.9 vs. 2.8±2.2, P=0.04). Among infants born at an average GA of 24 weeks', DCC appears safe, logistically feasible, and offers hematological and circulatory advantages compared with ICC. A more comprehensive appraisal of this practice is needed.

Detection capability of the IMS seismic network based on ambient seismic noise measurements

Science.gov (United States)

Gaebler, Peter J.; Ceranna, Lars

2016-04-01

All nuclear explosions - on the Earth's surface, underground, underwater or in the atmosphere - are banned by the Comprehensive Nuclear-Test-Ban Treaty (CTBT). As part of this treaty, a verification regime was put into place to detect, locate and characterize nuclear explosion testings at any time, by anyone and everywhere on the Earth. The International Monitoring System (IMS) plays a key role in the verification regime of the CTBT. Out of the different monitoring techniques used in the IMS, the seismic waveform approach is the most effective technology for monitoring nuclear underground testing and to identify and characterize potential nuclear events. This study introduces a method of seismic threshold monitoring to assess an upper magnitude limit of a potential seismic event in a certain given geographical region. The method is based on ambient seismic background noise measurements at the individual IMS seismic stations as well as on global distance correction terms for body wave magnitudes, which are calculated using the seismic reflectivity method. From our investigations we conclude that a global detection threshold of around mb 4.0 can be achieved using only stations from the primary seismic network, a clear latitudinal dependence for the detection threshold can be observed between northern and southern hemisphere. Including the seismic stations being part of the auxiliary seismic IMS network results in a slight improvement of global detection capability. However, including wave arrivals from distances greater than 120 degrees, mainly PKP-wave arrivals, leads to a significant improvement in average global detection capability. In special this leads to an improvement of the detection threshold on the southern hemisphere. We further investigate the dependence of the detection capability on spatial (latitude and longitude) and temporal (time) parameters, as well as on parameters such as source type and percentage of operational IMS stations.

Pituitary-gonadal and pituitary-thyroid axis hormone concentrations before and during a hypoglycemic clamp after sleep deprivation in healthy men.

Directory of Open Access Journals (Sweden)

Kamila Jauch-Chara

Full Text Available Total sleep deprivation (TSD exerts strong modulatory effects on the secretory activity of endocrine systems that might be related to TSD-induced challenges of cerebral glucose metabolism. Here, we investigate whether TSD affects the course of male pituitary-gonadal and pituitary-thyroid axis related hormones during a subsequent 240-min hypoglycemic clamp. Ten healthy men were tested on 2 different conditions, TSD and 7-hour regular sleep. Circulating concentrations of total testosterone, prolactin (PRL, thyroid stimulating hormone (TSH, free triiodothyronine (fT3, and free thyroxin (fT4 were measured during baseline and a subsequent hypoglycemic clamp taking place in the morning. Basal, i.e. at 07:00 am measured, concentrations of total testosterone (P = 0.05 and PRL (P<0.01 were lower while the values of TSH (P = 0.02, fT3 (P = 0.08, and fT4 (P = 0.04 were higher after TSD as compared to regular sleep. During the subsequent hypoglycemic clamp (all measurements from baseline to the end of the clamp analyzed total testosterone concentrations in the regular sleep (P<0.01 but not in the TSD condition (P = 0.61 decreased, while PRL levels increased (P = 0.05 irrespectively of the experimental condition (P = 0.31. TSH concentrations decreased during hypoglycemia (P<0.01, with this decrease being more pronounced after TSD (P = 0.04. However, at the end of the hypoglycemic clamp concentrations all of the above mentioned hormones did not differ between the two sleep conditions. Our data indicate a profound influence of TSD on male pituitary-gonadal and pituitary-thyroid axis hormones characterized by reduced basal testosterone and PRL levels and increased TSH levels. However, since concentrations of these hormones measured at the end of the 240-min hypoglycemic clamp were not affected by TSD it can be speculated that the influence of TSD on the two endocrine axes is rather short lived or does not interact in an additive

Georgia-Armenia Transboarder seismicity studies

Science.gov (United States)

Godoladze, T.; Tvaradze, N.; Javakishvili, Z.; Elashvili, M.; Durgaryan, R.; Arakelyan, A.; Gevorgyan, M.

2012-12-01

In the presented study we performed Comprehensive seismic analyses for the Armenian-Georgian transboarder active seismic fault starting on Armenian territory, cutting the state boarder and having possibly northern termination on Adjara-Triealeti frontal structure in Georgia. In the scope of International projects: ISTC A-1418 "Open network of scientific Centers for mitigation risk of natural hazards in the Southern Caucasus and Central Asia" and NATO SfP- 983284 Project "Caucasus Seismic Emergency Response" in Akhalkalaki (Georgia) seismic center, Regional Summer school trainings and intensive filed investigations were conducted. Main goal was multidisciplinary study of the Javakheti fault structure and better understanding seismicity of the area. Young scientists from Turkey, Armenia, Azerbaijan and Georgia were participated in the deployment of temporal seismic network in order to monitor seisimity on the Javakheti highland and particularly delineate fault scarf and identify active seismic structures. In the scope of international collaboration the common seismic database has been created in the southern Caucasus and collected data from the field works is available now online. Javakheti highland, which is located in the central part of the Caucasus, belongs to the structure of the lesser Caucasus and represents a history of neotectonic volcanism existed in the area. Jasvakheti highland is seismicalu active region devastating from several severe earthquakes(1088, 1283, 1899…). Hypocenters located during analogue network were highly scattered and did not describe real pattern of seismicity of the highland. We relocated hypocenters of the region and improved local velocity model. The hypocenters derived from recently deployed local seismic network in the Javakheti highland, clearly identified seismically active structures. Fault plane solutions of analogue data of the Soviet times have been carefully analyzed and examined. Moment tensor inversion were preformed

SEISMIC ANALYSIS FOR PRECLOSURE SAFETY

Energy Technology Data Exchange (ETDEWEB)

E.N. Lindner

2004-12-03

The purpose of this seismic preclosure safety analysis is to identify the potential seismically-initiated event sequences associated with preclosure operations of the repository at Yucca Mountain and assign appropriate design bases to provide assurance of achieving the performance objectives specified in the Code of Federal Regulations (CFR) 10 CFR Part 63 for radiological consequences. This seismic preclosure safety analysis is performed in support of the License Application for the Yucca Mountain Project. In more detail, this analysis identifies the systems, structures, and components (SSCs) that are subject to seismic design bases. This analysis assigns one of two design basis ground motion (DBGM) levels, DBGM-1 or DBGM-2, to SSCs important to safety (ITS) that are credited in the prevention or mitigation of seismically-initiated event sequences. An application of seismic margins approach is also demonstrated for SSCs assigned to DBGM-2 by showing a high confidence of a low probability of failure at a higher ground acceleration value, termed a beyond-design basis ground motion (BDBGM) level. The objective of this analysis is to meet the performance requirements of 10 CFR 63.111(a) and 10 CFR 63.111(b) for offsite and worker doses. The results of this calculation are used as inputs to the following: (1) A classification analysis of SSCs ITS by identifying potential seismically-initiated failures (loss of safety function) that could lead to undesired consequences; (2) An assignment of either DBGM-1 or DBGM-2 to each SSC ITS credited in the prevention or mitigation of a seismically-initiated event sequence; and (3) A nuclear safety design basis report that will state the seismic design requirements that are credited in this analysis. The present analysis reflects the design information available as of October 2004 and is considered preliminary. The evolving design of the repository will be re-evaluated periodically to ensure that seismic hazards are properly

SEISMIC ANALYSIS FOR PRECLOSURE SAFETY

International Nuclear Information System (INIS)

E.N. Lindner

2004-01-01

The purpose of this seismic preclosure safety analysis is to identify the potential seismically-initiated event sequences associated with preclosure operations of the repository at Yucca Mountain and assign appropriate design bases to provide assurance of achieving the performance objectives specified in the Code of Federal Regulations (CFR) 10 CFR Part 63 for radiological consequences. This seismic preclosure safety analysis is performed in support of the License Application for the Yucca Mountain Project. In more detail, this analysis identifies the systems, structures, and components (SSCs) that are subject to seismic design bases. This analysis assigns one of two design basis ground motion (DBGM) levels, DBGM-1 or DBGM-2, to SSCs important to safety (ITS) that are credited in the prevention or mitigation of seismically-initiated event sequences. An application of seismic margins approach is also demonstrated for SSCs assigned to DBGM-2 by showing a high confidence of a low probability of failure at a higher ground acceleration value, termed a beyond-design basis ground motion (BDBGM) level. The objective of this analysis is to meet the performance requirements of 10 CFR 63.111(a) and 10 CFR 63.111(b) for offsite and worker doses. The results of this calculation are used as inputs to the following: (1) A classification analysis of SSCs ITS by identifying potential seismically-initiated failures (loss of safety function) that could lead to undesired consequences; (2) An assignment of either DBGM-1 or DBGM-2 to each SSC ITS credited in the prevention or mitigation of a seismically-initiated event sequence; and (3) A nuclear safety design basis report that will state the seismic design requirements that are credited in this analysis. The present analysis reflects the design information available as of October 2004 and is considered preliminary. The evolving design of the repository will be re-evaluated periodically to ensure that seismic hazards are properly

Nuclear Tools For Oilfield Logging-While-Drilling Applications

International Nuclear Information System (INIS)

Reijonen, Jani

2011-01-01

Schlumberger is an international oilfield service company with nearly 80,000 employees of 140 nationalities, operating globally in 80 countries. As a market leader in oilfield services, Schlumberger has developed a suite of technologies to assess the downhole environment, including, among others, electromagnetic, seismic, chemical, and nuclear measurements. In the past 10 years there has been a radical shift in the oilfield service industry from traditional wireline measurements to logging-while-drilling (LWD) analysis. For LWD measurements, the analysis is performed and the instruments are operated while the borehole is being drilled. The high temperature, high shock, and extreme vibration environment of LWD imposes stringent requirements for the devices used in these applications. This has a significant impact on the design of the components and subcomponents of a downhole tool. Another significant change in the past few years for nuclear-based oilwell logging tools is the desire to replace the sealed radioisotope sources with active, electronic ones. These active radiation sources provide great benefits compared to the isotopic sources, ranging from handling and safety to nonproliferation and well contamination issues. The challenge is to develop electronic generators that have a high degree of reliability for the entire lifetime of a downhole tool. LWD tool testing and operations are highlighted with particular emphasis on electronic radiation sources and nuclear detectors for the downhole environment.

A SEISMIC DESIGN OF NUCLEAR REACTOR BUILDING STRUCTURES APPLYING SEISMIC ISOLATION SYSTEM IN A HIGH SEISMICITY REGION –A FEASIBILITY CASE STUDY IN JAPAN-

Directory of Open Access Journals (Sweden)

TETSUO KUBO

2014-10-01

Full Text Available A feasibility study on the seismic design of nuclear reactor buildings with application of a seismic isolation system is introduced. After the Hyogo-ken Nanbu earthquake in Japan of 1995, seismic isolation technologies have been widely employed for commercial buildings. Having become a mature technology, seismic isolation systems can be applied to NPP facilities in areas of high seismicity. Two reactor buildings are discussed, representing the PWR and BWR buildings in Japan, and the application of seismic isolation systems is discussed. The isolation system employing rubber bearings with a lead plug positioned (LRB is examined. Through a series of seismic response analyses using the so-named standard design earthquake motions covering the design basis earthquake motions obtained for NPP sites in Japan, the responses of the seismic isolated reactor buildings are evaluated. It is revealed that for the building structures examined herein: (1 the responses of both isolated buildings and isolating LRBs fulfill the specified design criteria; (2 the responses obtained for the isolating LRBs first reach the ultimate condition when intensity of motion is 2.0 to 2.5 times as large as that of the design-basis; and (3 the responses of isolated reactor building fall below the range of the prescribed criteria.

Seismic fragility capacity of equipment

International Nuclear Information System (INIS)

Iijima, Toru; Abe, Hiroshi; Suzuki, Kenichi

2006-01-01

Seismic probabilistic safety assessment (PSA) is an available method to evaluate residual risks of nuclear plants that are designed on definitive seismic conditions. From our preliminary seismic PSA analysis, horizontal shaft pumps are important components that have significant influences on the core damage frequency (CDF). An actual horizontal shaft pump and some kinds of elements were tested to evaluate realistic fragility capacities. Our test results showed that the realistic fragility capacity of horizontal shaft pump would be at least four times as high as a current value, 1.6 x 9.8 m/s 2 , used for our seismic PSA. We are going to incorporate the fragility capacity data that were obtained from those tests into our seismic PSA analysis, and we expect that the reliability of seismic PSA should increase. (author)

Battery charger with a capacitor-diode clamped LLC resonant converter

OpenAIRE

Tsang, C.; Bingham, C.; Foster, M. P.; Stone, D.; Leech, J.

2016-01-01

The paper proposes a novel battery charger through use of\\ud two serially-connected LLC resonant converters. The first\\ud stage utilises a capacitor-diode clamped LLC resonant\\ud converter which allows operation in both constant voltage\\ud (CV) and constant current (CC) modes, as found in most\\ud battery chargers, to be realised, whilst the second stage\\ud provides the necessary gain and line and load regulation. A\\ud design example is included that demonstrates the resulting\\ud converter top...

Two applications of time reversal mirrors: Seismic radio and seismic radar

KAUST Repository

Hanafy, Sherif M.

2011-07-08

Two seismic applications of time reversal mirrors (TRMs) are introduced and tested with field experiments. The first one is sending, receiving, and decoding coded messages similar to a radio except seismic waves are used. The second one is, similar to radar surveillance, detecting and tracking a moving object(s) in a remote area, including the determination of the objects speed of movement. Both applications require the prior recording of calibrationGreen’s functions in the area of interest. This reference Green’s function will be used as a codebook to decrypt the coded message in the first application and as a moving sensor for the second application. Field tests show that seismicradar can detect the moving coordinates ( x(t), y(t), z(t)) of a person running through a calibration site. This information also allows for a calculation of his velocity as a function of location. Results with the seismic radio are successful in seismically detecting and decoding coded pulses produced by a hammer. Both seismic radio and radar are highly robust to signals in high noise environments due to the super-stacking property of TRMs.

Balance control strategy of two-amplitude actively clamped resonant DC-Link inverter clamping voltage%双幅有源箝位谐振直流环节逆变器箝位电压平衡控制策略

Institute of Scientific and Technical Information of China (English)

陈沁野; 张德华; 侯尧杰

2012-01-01

Aiming at the big loss of the traditional clamping voltage balance control strategies, in two-amplitude actively clamped resonant DC-LINK inverter, the work process of DC link was analyzed. In order to keep the clamp capacitor voltage balance the value set in DC-link work, no short-circuit control was proposed.The DC-link of inverter was calculated by Mathcad. The loss of two modes of short-circuit control and no short-circuit control were compared.Under the no short-circuit control and voltage ripple is not be greater than twenty percent, the parameters of the clamp capacitor were calculated. The results indicate that, the micro-power ACRDCLI clamping voltage balance use no short-circuit control,that can reduce the loss of the DC link and can use thin-film capacitor as a clamp capacitor to achieve the micro-power ACRDCLI low loss and iong life requirements.%针对微型功率双幅有源箝位谐振直流环节逆变器在正常工作过程中,传统箝位电压平衡母线短路控制策略带来损耗大的问题,开展了直流环节工作过程的分析,针对直流环节正常工作的情况下,箝位电容电压必须能平衡在设定值,提出了箝位电压平衡母线无短路控制策略,根据给出的损耗估算方法,通过Mathcad计算,对比了母线短路控制和无短路控制两种方式下的损耗,同时计算出了母线无短路控制箝位电容电压纹波不大于20％下的箝位电容参数.研究结果表明:微型功率ACRDCLI箝位电压平衡采用母线无短线控制,不但可以减少双幅有源箝位谐振直流环节逆变器的损耗,并且可以使用薄膜电容作为箝位电容,以达到微型功率ACRDCLI损耗低、寿命长的要求.

Hda monomerization by ADP binding promotes replicase clamp-mediated DnaA-ATP hydrolysis.

Science.gov (United States)

Su'etsugu, Masayuki; Nakamura, Kenta; Keyamura, Kenji; Kudo, Yuka; Katayama, Tsutomu

2008-12-26

ATP-DnaA is the initiator of chromosomal replication in Escherichia coli, and the activity of DnaA is regulated by the regulatory inactivation of the DnaA (RIDA) system. In this system, the Hda protein promotes DnaA-ATP hydrolysis to produce inactive ADP-DnaA in a mechanism that is mediated by the DNA-loaded form of the replicase sliding clamp. In this study, we first revealed that hda translation uses an unusual initiation codon, CUG, located downstream of the annotated initiation codon. The CUG initiation codon could be used for restricting the Hda level, as this initiation codon has a low translation efficiency, and the cellular Hda level is only approximately 100 molecules per cell. Hda translated using the correct reading frame was purified and found to have a high RIDA activity in vitro. Moreover, we found that Hda has a high affinity for ADP but not for other nucleotides, including ATP. ADP-Hda was active in the RIDA system in vitro and stable in a monomeric state, whereas apo-Hda formed inactive homomultimers. Both ADP-Hda and apo-Hda could form complexes with the DNA-loaded clamp; however, only ADP-Hda-DNA-clamp complexes were highly functional in the following interaction with DnaA. Formation of ADP-Hda was also observed in vivo, and mutant analysis suggested that ADP binding is crucial for cellular Hda activity. Thus, we propose that ADP is a crucial Hda ligand that promotes the activated conformation of the protein. ADP-dependent monomerization might enable the arginine finger of the Hda AAA+ domain to be accessible to ATP bound to the DnaA AAA+ domain.

Two applications of time reversal mirrors: Seismic radio and seismic radar

KAUST Repository

Hanafy, Sherif M.; Schuster, Gerard T.

2011-01-01

Two seismic applications of time reversal mirrors (TRMs) are introduced and tested with field experiments. The first one is sending, receiving, and decoding coded messages similar to a radio except seismic waves are used. The second one is, similar

Co-ordinated research programme on benchmark study for the seismic analysis and testing of WWER-type nuclear power plants. V. 5C. Experience data. Working material

International Nuclear Information System (INIS)

1999-01-01

In August 1991, following the SMiRT-11 Conference in Tokyo, a Technical Committee Meeting was held on the 'Seismic safety issues relating to existing NPPs'. The Proceedings of this TCM was subsequently compiled in an IAEA Working Material. One of the main recommendations of this TCM, called for the harmonization of criteria and methods used in Member States in seismic reassessment and upgrading of existing NPPs. Twenty four institutions from thirteen countries participated in the CRP named 'Benchmark study for the seismic analysis and testing of WWER type NPPs'. Two types of WWER reactors (WWER-1000 and WWER-440/213) selected for benchmarking. Kozloduy NPP Units 5/6 and Paks NPP represented these respectively as prototypes. Consistent with the recommendations of the TCM and the working paper prepared by the subsequent Consultants' Meeting, the focal activity of the CRP was the benchmarking exercises. A similar methodology was followed both for Paks NPP and Kozloduy NPP Unit 5. Firstly, the NPP (mainly the reactor building) was tested using a blast loading generated by a series of explosions from buried TNT charges. Records from this test were obtained at several free field locations (both downhole and surface), foundation mat, various elevations of structures as well as some tanks and the stack. Then the benchmark participants were provided with structural drawings, soil data and the free field record of the blast experiment. Their task was to make a blind prediction of the response at preselected locations. The analytical results from these participants were then compared with the results from the test. Although the benchmarking exercises constituted the focus of the CRP, there were many other interesting problems related to the seismic safety of WWER type NPPs which were addressed by the participants. These involved generic studies, i.e. codes and standards used in original WWER designs and their comparison with current international practice; seismic analysis

Potassium Chloride Versus Voltage Clamp Contractures in Ventricular Muscle

Science.gov (United States)

Morad, M.; Reeck, S.; Rao, M.

1981-01-01

In frog ventricle, developed tension was markedly larger in response to depolarization caused by a voltage clamp step than to depolarization induced by high concentrations of potassium chloride. Measurement of extracellular potassium activity at the surface and at the depth of muscle during the development of contractures showed that the diffusion of potassium is much slower than the spread of depolarization through the cross section of muscle. These two observations suggest that competition between the depolarizing and the negative inotropic effects of an increase in the extracellular potassium ion concentration may determine the time course and magnitude of contractile tension in heart muscle.

Inferring the lithology of borehole rocks by applying neural network classifiers to downhole logs: an example from the Ocean Drilling Program

Science.gov (United States)

Benaouda, D.; Wadge, G.; Whitmarsh, R. B.; Rothwell, R. G.; MacLeod, C.

1999-02-01

In boreholes with partial or no core recovery, interpretations of lithology in the remainder of the hole are routinely attempted using data from downhole geophysical sensors. We present a practical neural net-based technique that greatly enhances lithological interpretation in holes with partial core recovery by using downhole data to train classifiers to give a global classification scheme for those parts of the borehole for which no core was retrieved. We describe the system and its underlying methods of data exploration, selection and classification, and present a typical example of the system in use. Although the technique is equally applicable to oil industry boreholes, we apply it here to an Ocean Drilling Program (ODP) borehole (Hole 792E, Izu-Bonin forearc, a mixture of volcaniclastic sandstones, conglomerates and claystones). The quantitative benefits of quality-control measures and different subsampling strategies are shown. Direct comparisons between a number of discriminant analysis methods and the use of neural networks with back-propagation of error are presented. The neural networks perform better than the discriminant analysis techniques both in terms of performance rates with test data sets (2-3 per cent better) and in qualitative correlation with non-depth-matched core. We illustrate with the Hole 792E data how vital it is to have a system that permits the number and membership of training classes to be changed as analysis proceeds. The initial classification for Hole 792E evolved from a five-class to a three-class and then to a four-class scheme with resultant classification performance rates for the back-propagation neural network method of 83, 84 and 93 per cent respectively.

3D Modelling of Seismically Active Parts of Underground Faults via Seismic Data Mining

Science.gov (United States)

Frantzeskakis, Theofanis; Konstantaras, Anthony

2015-04-01

During the last few years rapid steps have been taken towards drilling for oil in the western Mediterranean sea. Since most of the countries in the region benefit mainly from tourism and considering that the Mediterranean is a closed sea only replenishing its water once every ninety years careful measures are being taken to ensure safe drilling. In that concept this research work attempts to derive a three dimensional model of the seismically active parts of the underlying underground faults in areas of petroleum interest. For that purpose seismic spatio-temporal clustering has been applied to seismic data to identify potential distinct seismic regions in the area of interest. Results have been coalesced with two dimensional maps of underground faults from past surveys and seismic epicentres, having followed careful reallocation processing, have been used to provide information regarding the vertical extent of multiple underground faults in the region of interest. The end product is a three dimensional map of the possible underground location and extent of the seismically active parts of underground faults. Indexing terms: underground faults modelling, seismic data mining, 3D visualisation, active seismic source mapping, seismic hazard evaluation, dangerous phenomena modelling Acknowledgment This research work is supported by the ESPA Operational Programme, Education and Life Long Learning, Students Practical Placement Initiative. References [1] Alves, T.M., Kokinou, E. and Zodiatis, G.: 'A three-step model to assess shoreline and offshore susceptibility to oil spills: The South Aegean (Crete) as an analogue for confined marine basins', Marine Pollution Bulletin, In Press, 2014 [2] Ciappa, A., Costabile, S.: 'Oil spill hazard assessment using a reverse trajectory method for the Egadi marine protected area (Central Mediterranean Sea)', Marine Pollution Bulletin, vol. 84 (1-2), pp. 44-55, 2014 [3] Ganas, A., Karastathis, V., Moshou, A., Valkaniotis, S., Mouzakiotis

Improving reservoir performance using new 'smart' well technology

International Nuclear Information System (INIS)

Roggensack, W.D.; Matthews, C.M.

1997-01-01

The technologies that were available in the past to improve reservoir performance include 3-D seismic, coiled tubing, horizontal wells, and PCP's. Future enabling technologies will also include multi-lateral wells, 'smart' wells, underbalanced drilling, and downhole fluids processing. A description of 'smart' well technology was given, defined as well completions which facilitate downhole monitoring and control of production to achieve maximum reserves recovery. The current development for 'smart' wells is focused on offshore and subsea wells for marginal field development and work-over mitigation, with the emphasis in system design for production control of horizontal and multi-lateral wells. Basic 'smart' well configuration, instrumentation and monitoring systems, applications of 'smart' well technology in the Western Canadian Sedimentary Basin, and future developments and applications for the technology in general, were also discussed. 30 figs

Overmodulation of n-level three-leg DC-AC diode-clamped converters with comprehensive capacitor voltage balance

DEFF Research Database (Denmark)

Busquets-Monge, S.; Maheshwari, Ram Krishan; Munk-Nielsen, Stig

2013-01-01

This paper presents a novel PWM strategy for nlevel three-leg semiconductor-clamped dc-ac converters in the overmodulation region, with dc-link capacitor voltage balance in every switching cycle. The strategy is based on the virtual-vector concept. Suitable reference vector trajectories are selec......This paper presents a novel PWM strategy for nlevel three-leg semiconductor-clamped dc-ac converters in the overmodulation region, with dc-link capacitor voltage balance in every switching cycle. The strategy is based on the virtual-vector concept. Suitable reference vector trajectories...

Enhanced static ground power unit based on flying capacitor based h-bridge hybrid active-neutral-point-clamped converter

DEFF Research Database (Denmark)

Abarzadeh, Mostafa; Madadi Kojabadi, Hossein; Deng, Fujin

2016-01-01

Static power converters have various applications, such as static ground power units (GPUs) for airplanes. This study proposes a new configuration of a static GPU based on a novel nine-level flying capacitor h-bridge active-neutral-point-clamped (FCHB_ANPC) converter. The main advantages of the p......Static power converters have various applications, such as static ground power units (GPUs) for airplanes. This study proposes a new configuration of a static GPU based on a novel nine-level flying capacitor h-bridge active-neutral-point-clamped (FCHB_ANPC) converter. The main advantages...