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Sample records for integrated transponder pit

  1. Evaluation of remote delivery of Passive Integrated Transponder (PIT technology to mark large mammals.

    Directory of Open Access Journals (Sweden)

    W David Walter

    Full Text Available Methods to individually mark and identify free-ranging wildlife without trapping and handling would be useful for a variety of research and management purposes. The use of Passive Integrated Transponder technology could be an efficient method for collecting data for mark-recapture analysis and other strategies for assessing characteristics about populations of various wildlife species. Passive Integrated Transponder tags (PIT have unique numbered frequencies and have been used to successfully mark and identify mammals. We tested for successful injection of PIT and subsequent functioning of PIT into gelatin blocks using 4 variations of a prototype dart. We then selected the prototype dart that resulted in the least depth of penetration in the gelatin block to assess the ability of PIT to be successfully implanted into muscle tissue of white-tailed deer (Odocoileus virginianus post-mortem and long-term in live, captive Rocky Mountain elk (Cervus elaphus. The prototype dart with a 12.7 mm (0.5 inch needle length and no powder charge resulted in the shallowest mean (± SD penetration depth into gelatin blocks of 27.0 mm (± 5.6 mm with 2.0 psi setting on the Dan-Inject CO(2-pressured rifle. Eighty percent of PIT were successfully injected in the muscle mass of white-tailed deer post-mortem with a mean (± SD penetration depth of 22.2 mm (± 3.8 mm; n = 6. We injected PIT successfully into 13 live, captive elk by remote delivery at about 20 m that remained functional for 7 months. We successfully demonstrated that PIT could be remotely delivered in darts into muscle mass of large mammals and remain functional for >6 months. Although further research is warranted to fully develop the technique, remote delivery of PIT technology to large mammals is possible using prototype implant darts.

  2. Monitoring Eastern Spadefoot (Scaphiopus holbrookii) response to weather with the use of a passive integrated transponder (PIT) system

    Science.gov (United States)

    Ryan, Kevin J.; Calhoun, Aram J.K.; Timm, Brad C.; Zydlewski, Joseph D.

    2015-01-01

    Eastern Spadefoots (Scaphiopus holbrookii) are probably one of the least-understood amphibian species in the United States. In New England, populations are localized and it is likely that some populations go undocumented because of the species' cryptic habits. We used passive integrated transponders (PIT tags) to monitor burrow emergence with the aid of continuously running, stationary (but portable) PIT tag readers. We monitored the activity of individual Eastern Spadefoots by placing circular antennae directly over burrows of PIT tag-implanted individuals. We monitored 18 Eastern Spadefoots from 1 to 84 nights in the spring, summer, and fall of 2009–2011. Our results indicate that, on average, Eastern Spadefoots emerged on 43% of the nights that they were monitored. Nights when Eastern Spadefoots emerged were warmer and more humid than nonemergence nights. Eastern Spadefoots were also much more likely to emerge on a given night if they had emerged the night before. Our results have improved the understanding of Eastern Spadefoot burrow-emergence patterns in the northeast region. Our findings may considerably enhance the prospect of employing nocturnal visual encounter surveys as a method for monitoring known, and detecting previously undocumented, populations of this species.

  3. Effects of passive integrated transponder tags on survival and growth of juvenile Atlantic salmon Salmo salar

    DEFF Research Database (Denmark)

    Larsen, Martin Hage; Thorn, Aske N.; Skov, Christian

    2013-01-01

    Background: A laboratory experiment was conducted to assess the potential impacts of surgically implanted 23 and 32 mm passive integrated transponder (PIT) tags on survival, growth, and body condition of juvenile Atlantic salmon Salmo salar. Rate of tag retention and healing of the tagging incision...... were also evaluated. Atlantic salmon of three different size classes (I: 80 to 99 mm fork length (FL), II: 100 to 119 mm FL, III: 120 to 135 mm FL) were allocated to each of five experimental treatment groups: control, sham-operated (surgery without PIT-tag implantation), 23 mm PIT-tag implantation...... with and without suture closure of the incision, and 32 mm PIT-tag implantation without suture closure. Results: Over the 35-day experiment, mortality occurred only among fish tagged with 32 mm PIT tags (14%) and all fish larger than 103 mm FL survived. Non-sutured Atlantic salmon between 80 and 99 mm FL implanted...

  4. Efficiency of Portable Antennas for Detecting Passive Integrated Transponder Tags in Stream-Dwelling Salmonids.

    Directory of Open Access Journals (Sweden)

    Nolan P Banish

    Full Text Available Portable antennas have become an increasingly common technique for tracking fish marked with passive integrated transponder (PIT tags. We used logistic regression to evaluate how species, fish length, and physical habitat characteristics influence portable antenna detection efficiency in stream-dwelling brown trout (Salmo trutta, bull trout (Salvelinus confluentus, and redband trout (Oncorhynchus mykiss newberrii marked with 12-mm PIT tags. We redetected 56% (20/36 of brown trout, 34% (68/202 of bull trout, and 33% (20/61 of redband trout after a recovery period of 21 to 46 hours. Models indicate support for length and species and minor support for percent boulder, large woody debris, and percent cobble as parameters important for describing variation in detection efficiency, although 95% confidence intervals for estimates were large. The odds of detecting brown trout (1.5 ± 2.2 [mean ± SE] are approximately four times as high as bull trout (0.4 ± 1.6 or redband trout (0.3 ± 1.8 and species-specific differences may be related to length. Our reported detection efficiency for brown trout falls within the range of other studies, but is the first reported for bull trout and redband trout. Portable antennas may be a relatively unbiased way of redetecting varying sizes of all three salmonid species.

  5. Efficiency of portable antennas for detecting passive integrated transponder tags in stream-dwelling salmonids

    Science.gov (United States)

    Banish, Nolan P.; Burdick, Summer M.; Moyer, Katherine R.

    2016-01-01

    Portable antennas have become an increasingly common technique for tracking fish marked with passive integrated transponder (PIT) tags. We used logistic regression to evaluate how species, fish length, and physical habitat characteristics influence portable antenna detection efficiency in stream-dwelling brown trout (Salmo trutta), bull trout (Salvelinus confluentus), and redband trout (Oncorhynchus mykiss newberrii) marked with 12-mm PIT tags. We redetected 56% (20/36) of brown trout, 34% (68/202) of bull trout, and 33% (20/61) of redband trout after a recovery period of 21 to 46 hours. Models indicate support for length and species and minor support for percent boulder, large woody debris, and percent cobble as parameters important for describing variation in detection efficiency, although 95% confidence intervals for estimates were large. The odds of detecting brown trout (1.5 ± 2.2 [mean ± SE]) are approximately four times as high as bull trout (0.4 ± 1.6) or redband trout (0.3 ± 1.8) and species-specific differences may be related to length. Our reported detection efficiency for brown trout falls within the range of other studies, but is the first reported for bull trout and redband trout. Portable antennas may be a relatively unbiased way of redetecting varying sizes of all three salmonid species.

  6. Colonial waterbird predation on Lost River and shortnose suckers based on recoveries of passive integrated transponder tags

    Science.gov (United States)

    Evans, Allen; Payton, Quinn; Cramer, Bradley D.; Collis, Ken; Hewitt, David A.; Roby, Daniel D.

    2015-01-01

    We evaluated predation on Lost River suckers (Deltistes luxatus) and shortnose suckers (Chasmistes brevirostris), both listed under the Endangered Species Act (ESA), from American white pelicans (Pelecanus erythrorhynchos) and double-crested cormorants (Phalacrocorax auritus) nesting at mixed species colonies on Clear Lake Reservoir, CA and Upper Klamath Lake, OR during 2009-2014. Predation was evaluated by recovering passive integrated transponder (PIT) tags that were implanted in suckers, subsequently consumed by pelicans or cormorants, and deposited on the birds’ nesting colonies. Data from PIT tag recoveries were used to estimate predation rates (proportion of available tagged suckers consumed) by birds to evaluate the relative susceptibility of suckers to avian predation in Upper Klamath Basin. Data on the size of pelican and cormorant colonies (number of breeding adults) at Clear Lake and Upper Klamath Lake were also collected and reported in the context of predation on suckers.

  7. Development and Evaluation of Passive Integrated Transponder Tag Technology, 2000-2002.

    Energy Technology Data Exchange (ETDEWEB)

    Downing, Sandra L.; Prentice, Earl F.; Nunnallee, Edmund P. [National Marine Fisheries Service

    2009-04-03

    Since 1984, the National Marine Fisheries Service (NMFS) in cooperation with the Bonneville Power Administration (BPA) has conducted a research project to develop and evaluate technology for passive-integrated-transponder tags (PIT tags) throughout the Columbia River Basin (CRB). Work conducted as part of this project between October 2000 and September 2002 (FY01 and FY02) was divided into seven individual elements, which are covered separately in this report. The efforts by personnel associated with this project have produced and will continue to produce products that aid resource stakeholders in assessing the effectiveness of actions taken to enhance the survival of juvenile and adult salmonids. These products and their uses include: (1) Survival and migration timing information on stocks to evaluate water management strategies and fish passage/collection facilities; (2) Data needed for the management and restoration of salmonids and other fish stocks listed under the Endangered Species Act (ESA); (3) Information required for the management of multiple species in a variety of habitats; and (4) Tools that enable fisheries researchers and managers to address previously unanswerable questions and critical uncertainties These products are also used in genetic, physiology, behavior, and captive broodstock research on endangered species. The continued development of PIT-tag technology will enable researchers and fisheries managers to address issues expressed in both of NMFS biological opinions for operation of the Federal Columbia River Power System (FCRPS)(NMFS 1995a, 2000) and the proposed Snake River Recovery Plan (NMFS 1995b; tasks 2.1.d, 2.3.b.4, 2.4.a, 2.6.c.2, and 2.9.d).

  8. Integration of thin film giant magnetoimpedance sensor and surface acoustic wave transponder

    KAUST Repository

    Li, Bodong

    2012-03-09

    Passive and remote sensing technology has many potential applications in implantable devices, automation, or structural monitoring. In this paper, a tri-layer thin film giant magnetoimpedance (GMI) sensor with the maximum sensitivity of 16%/Oe and GMI ratio of 44% was combined with a two-port surface acoustic wave(SAW) transponder on a common substrate using standard microfabrication technology resulting in a fully integrated sensor for passive and remote operation. The implementation of the two devices has been optimized by on-chip matching circuits. The measurement results clearly show a magnetic field response at the input port of the SAW transponder that reflects the impedance change of the GMI sensor.

  9. Integration of thin film giant magnetoimpedance sensor and surface acoustic wave transponder

    KAUST Repository

    Li, Bodong; Salem, Nedime Pelin M. H.; Giouroudi, Ioanna; Kosel, Jü rgen

    2012-01-01

    Passive and remote sensing technology has many potential applications in implantable devices, automation, or structural monitoring. In this paper, a tri-layer thin film giant magnetoimpedance (GMI) sensor with the maximum sensitivity of 16%/Oe and GMI ratio of 44% was combined with a two-port surface acoustic wave(SAW) transponder on a common substrate using standard microfabrication technology resulting in a fully integrated sensor for passive and remote operation. The implementation of the two devices has been optimized by on-chip matching circuits. The measurement results clearly show a magnetic field response at the input port of the SAW transponder that reflects the impedance change of the GMI sensor.

  10. Tagging effects of passive integrated transponder and visual implant elastomer on the small-bodied white sands pupfish (Cyprinodon tularosa)

    Science.gov (United States)

    Peterson, Damon; Trantham, Randi B.; Trantham, Tulley G.; Caldwell, Colleen A.

    2018-01-01

    One of the greatest limiting factors of studies designed to obtain growth, movement, and survival in small-bodied fishes is the selection of a viable tag. The tag must be relatively small with respect to body size as to impart minimal sub-lethal effects on growth and mobility, as well as be retained throughout the life of the fish or duration of the study. Thus, body size of the model species becomes a major limiting factor; yet few studies have obtained empirical evidence of the minimum fish size and related tagging effects. The probability of surviving a tagging event was quantified in White Sands pupfish (Cyprinodon tularosa) across a range of sizes (19–60 mm) to address the hypothesis that body size predicts tagging survival. We compared tagging related mortality, individual taggers, growth, and tag retention in White Sands pupfish implanted with 8-mm passive integrated transponder (PIT), visual implant elastomer (VIE), and control (handled similarly, but no tag implantation) over a 75 d period. Initial body weight was a good predictor of the probability of survival in PIT- and VIE-tagged fish. As weight increased by 1 g, the fish were 4.73 times more likely to survive PIT-tag implantation compared to the control fish with an estimated suitable tagging size at 1.1 g (TL: 39.29 ± 0.41 mm). Likewise, VIE-tagged animals were 2.27 times more likely to survive a tagging event compared to the control group for every additional 1 g with an estimated size suitable for tagging of 0.9 g (TL: 36.9 ± 0.36 mm) fish. Growth rates of PIT- and VIE-tagged White Sands pupfish were similar to the control groups. This research validated two popular tagging methodologies in the White Sands pupfish, thus providing a valuable tool for characterizing vital rates in other small-bodied fishes.

  11. Estimating movement and survival rates of a small saltwater fish using autonomous antenna receiver arrays and passive integrated transponder tags

    Science.gov (United States)

    Rudershausen, Paul J.; Buckel, Jeffery A.; Dubreuil, Todd; O'Donnell, Matthew J.; Hightower, Joseph E.; Poland, Steven J.; Letcher, Benjamin H.

    2014-01-01

    We evaluated the performance of small (12.5 mm long) passive integrated transponder (PIT) tags and custom detection antennas for obtaining fine-scale movement and demographic data of mummichog Fundulus heteroclitus in a salt marsh creek. Apparent survival and detection probability were estimated using a Cormack Jolly Seber (CJS) model fitted to detection data collected by an array of 3 vertical antennas from November 2010 to March 2011 and by a single horizontal antenna from April to August 2011. Movement of mummichogs was monitored during the period when the array of vertical antennas was used. Antenna performance was examined in situ using tags placed in wooden dowels (drones) and in live mummichogs. Of the 44 tagged fish, 42 were resighted over the 9 mo monitoring period. The in situ detection probabilities of the drone and live mummichogs were high (~80-100%) when the ambient water depth was less than ~0.8 m. Upstream and downstream movement of mummichogs was related to hourly water depth and direction of tidal current in a way that maximized time periods over which mummichogs utilized the intertidal vegetated marsh. Apparent survival was lower during periods of colder water temperatures in December 2010 and early January 2011 (median estimate of daily apparent survival = 0.979) than during other periods of the study (median estimate of daily apparent survival = 0.992). During late fall and winter, temperature had a positive effect on the CJS detection probability of a tagged mummichog, likely due to greater fish activity over warmer periods. During the spring and summer, this pattern reversed possibly due to mummichogs having reduced activity during the hottest periods. This study demonstrates the utility of PIT tags and continuously operating autonomous detection systems for tracking fish at fine temporal scales, and improving estimates of demographic parameters in salt marsh creeks that are difficult or impractical to sample with active fishing gear.

  12. Evaluation of PIT-tagging in cyprinids

    DEFF Research Database (Denmark)

    Skov, Christian; Brodersen, J.; Brönmark, C.

    2005-01-01

    Laboratory and field experiments were used to investigate how different marking procedures, with 23 mm PIT (passive integrated transponders) - tags. affected mortality, body condition and tag expulsion in small roach Rutilus rutilus and rudd Scardinus erythrophthalmus (117 to 163 mm total length...

  13. PIT-tagging method for small fishes: A case study using sandeel ( Ammodytes tobianus )

    DEFF Research Database (Denmark)

    Jørgensen, Michelle Grace Pinto; Deurs, Mikael van; Butts, Ian

    2017-01-01

    Passive integrated transponder (PIT) tags are commonly used to assess fish movement for use in fisheries management. Here, we investigated physiological and behavioral effects of tagging on sandeels (Ammodytes tobianus) using PIT tags constituting 2.1 ± 0.9% of their body weight. Swimming stamina...

  14. Investigating fish hydraulic habitat preferences using a passive integrated transponder antenna network: Scope on spatial scales and individual mobility

    Science.gov (United States)

    Roy, M. L.; Roy, A. G.

    2009-12-01

    Flow velocity is a major feature of fluvial fish habitat. It affects swimming energy expenditures, resource distribution and efficiency of prey capture, thus exerting a major influence on fish distribution. Preferences of juvenile salmonids for ranges of flow velocity are well documented. Preference curves are usually generated by comparing velocities measured at the precise location of captured fish (nose velocity) with velocities measured at random locations where fish are absent. However, these preferences tend to be specific to sites and rivers and show important variability with time. Recent biotelemetry studies have revealed that juvenile salmonids are more mobile than previously assumed and use larger home ranges and multiple micro-habitats. Therefore, fish might select habitats based on the characteristics of a microhabitat, but also based on the properties of the surrounding area. Furthermore, mobile fish could present temporal variability in their habitat preferences. Recent advances in biotelemetry provide new ways to monitor fish locations and to obtain habitat preferences both at the individual and the population levels at high temporal and spatial resolutions for extended periods. In this study, we seek to identify the most relevant spatial scales defining habitat preferences of juvenile Atlantic salmon. We emphasize both the group and individual temporal variability in hydraulic habitat preferences. During a three month period, we monitored the location and movements of 61 juveniles marked with 23-mm passive integrated transponders (PIT) using a network of 186 antennas buried into the bed of a natural river reach in Saguenay, Canada. Each antenna was scanned every 33 seconds to detect and record the presence or absence of tagged fish. The reach was 70 m long and 9 m wide on average and presented a very clear morphological sequence consisting of two pools separated by a riffle. Mean flow velocity and turbulent flow properties were measured at 3500

  15. Pb(Zr,TiO3 (PZT Thin Film Sensors for Fully-Integrated, Passive Telemetric Transponders

    Directory of Open Access Journals (Sweden)

    Richard X. FU

    2011-04-01

    Full Text Available The great potential of taking advantages of PZT in a single chip to achieve inexpensive, fully-integrated, passive telemetric transponders has been shown in this paper. The processes for the sputter deposition of Pb(Zr,TiO3 (PZT thin films from two different composite targets on both Si and c-plane sapphire substrates have been demonstrated. PZT thin films have been deposited by sputter technique. PZT films were deposited onto substrates (Si [(100 Cz wafer] and c-plane sapphire (0001//Ti//Pt followed by sputter-deposited Pt top electrodes. X-ray diffraction results showed that both sputtered PZT films were textured along the [110] direction. The degree of preference for the [110] direction was greater on sapphire substrate where the intensity of that peak is seen to be larger compared to the intensity one Si substrate. TEM data revealed that both sputtered PZT films were polycrystalline in nature. Selected area diffraction (SAD pattern showed that the degree of disorientation between the crystallites was smaller on sapphire substrate compared to on Si substrate, which confirmed the results from the XRD. The remnant polarization Pr on sapphire substrate was larger than on Si’s. The leakage current for the 11 % Pb target sputtered film was much less than 22 % Pb target sputtered film. The breakdown voltage on sapphire substrate was the best. However, for the 11 % Pb target sputtered film’s breakdown voltage was much higher than 22 % Pb target sputtered film.

  16. PIT Tagging Anurans

    Science.gov (United States)

    McCreary, Brome

    2008-01-01

    The following video demonstrates a procedure to insert a passive integrated transponder (PIT) tag under the skin of an anuran (frog or toad) for research and monitoring purposes. Typically, a 12.5 mm tag (0.5 in.) is used to uniquely identify individual anurans as smal as 40 mm (1.6 in.) in length from snout to vent. Smaller tags are also available and allow smaller anurans to be tagged. The procedure does not differ for other sizes of tages or other sizes of anurans. Anyone using this procedure should ensure that the tag is small enough to fit easily behind the sacral hump of the anuran, as shown in this video.

  17. Integrating Safeguards into the Pit Disassembly and Conversion Facility

    International Nuclear Information System (INIS)

    Clark, T.G.

    2002-01-01

    In September 2000, the United States and the Russian Federation entered into an agreement which stipulates each country will irreversibly transform 34 metric tons of weapons-grade plutonium into material which could not be used for weapon purposes. Supporting the Department of Energy's (DOE) program to dispose of excess nuclear materials, the Pit Disassembly and Conversion Facility (PDCF) is being designed and constructed to disassemble the weapon ''pits'' and convert the nuclear material to an oxide form for fabrication into reactor fuel at the separate Mixed Oxide Fuel Fabrication Facility. The PDCF design incorporates automation to the maximum extent possible to facilitate material safeguards, reduce worker dose, and improve processing efficiency. This includes provisions for automated guided vehicle movements for shipping containers, material transport via automated conveyor between processes, remote process control monitoring, and automated Nondestructive Assay product systems

  18. Cormorant predation on PIT-tagged lake fish

    DEFF Research Database (Denmark)

    Skov, Christian; Jepsen, Niels; Baktoft, Henrik

    2014-01-01

    The present study use data from recovered PIT (Passive Integrated Transponder) tags to explore species-and size-specific annual predation rates by cormorants on three common lacustrine fishes (size range 120-367 mm) in a European lake; roach (Rutilus rutilus), common bream (Abramis brama) and perch...... (Perca fluviatilis). In addition, we quantify the level of age/size truncation that cormorant predation could introduce in a population of perch, an important fish for recreational angling as well as for trophic interactions and ecosystem function in European lakes. Based on three years of PIT tagging...... of fish in Lake Viborg and subsequent recoveries of PIT tags from nearby cormorant roosting and breeding sites, we show that cormorants are major predators of roach, bream and perch within the size groups we investigated and for all species larger individuals had higher predation rates. Perch appear...

  19. Pitting temporal against spatial integration in schizophrenic patients.

    Science.gov (United States)

    Herzog, Michael H; Brand, Andreas

    2009-06-30

    Schizophrenic patients show strong impairments in visual backward masking possibly caused by deficits on the early stages of visual processing. The underlying aberrant mechanisms are not clearly understood. Spatial as well as temporal processing deficits have been proposed. Here, by combining a spatial with a temporal integration paradigm, we show further evidence that temporal but not spatial processing is impaired in schizophrenic patients. Eleven schizophrenic patients and ten healthy controls were presented with sequences composed of Vernier stimuli. Patients needed significantly longer presentation times for sequentially presented Vernier stimuli to reach a performance level comparable to that of healthy controls (temporal integration deficit). When we added spatial contextual elements to some of the Vernier stimuli, performance changed in a complex but comparable manner in patients and controls (intact spatial integration). Hence, temporal but not spatial processing seems to be deficient in schizophrenia.

  20. Crevice corrosion ampersand pitting of high-level waste containers: integration of deterministic ampersand probabilistic models

    International Nuclear Information System (INIS)

    Farmer, J.C.; McCright, R.D.

    1997-01-01

    A key component of the Engineered Barrier System (EBS) being designed for containment of spent-fuel and high-level waste at the proposed geological repository at Yucca Mountain, Nevada is a two-layer canister. In this particular design, the inner barrier is made of a corrosion resistant material (CRM) such as Alloy 625 or C-22, while the outer barrier is made of a corrosion-allowance material (CAM) such as carbon steel or Monel 400. An integrated predictive model is being developed to account for the effects of localized environmental conditions in the CRM-CAM crevice on the initiation and propagation of pits through the CRM

  1. CREVICE CORROSION and PITTING OF HIGH-LEVEL WASTE CONTAINERS: INTEGRATION OF DETERMINISTIC and PROBABILISTIC MODELS

    International Nuclear Information System (INIS)

    JOSEPH C. FARMER AND R. DANIEL MCCRIGHT

    1997-01-01

    A key component of the Engineered Barrier System (EBS) being designed for containment of spent-fuel and high-level waste at the proposed geological repository at Yucca Mountain, Nevada is a two-layer canister. In this particular design, the inner barrier is made of a corrosion resistant material (CRM) such as Alloy 625 or C-22, while the outer barrier is made of a corrosion-allowance material (CAM) such as carbon steel or Monel 400. An integrated predictive model is being developed to account for the effects of localized environmental conditions in the CRM-CAM crevice on the initiation and propagation of pits through the CRM

  2. Development of a Switching Passive 2.4 GHz RFID Transponder on Flexible Substrate

    NARCIS (Netherlands)

    Hoogeboom, P.; Elferink, F.H.; Trampuz, C.

    2009-01-01

    For the detection and tracking of a football on a playground, a transponder was developed on a flexible substrate suitable for integration in the ball. The transponder secures permanent detection and identification with FMCW radar, thus enabling an easy and cost-effective tracking of the ball. The

  3. Guidelines for calculating and enhancing detection efficiency of PIT tag interrogation systems

    Science.gov (United States)

    Connolly, Patrick J.

    2010-01-01

    With increasing use of passive integrated transponder (PIT) tags and reliance on stationary PIT tag interrogation systems to monitor fish populations, guidelines are offered to inform users how best to use limited funding and human resources to create functional systems that maximize a desired level of detection and precision. The estimators of detection efficiency and their variability as described by Connolly et al. (2008) are explored over a span of likely performance metrics. These estimators were developed to estimate detection efficiency without relying on a known number of fish passing the system. I present graphical displays of the results derived from these estimators to show the potential efficiency and precision to be gained by adding an array or by increasing the number of PIT-tagged fish expected to move past an interrogation system.

  4. Guidelines to indirectly measure and enhance detection efficiency of stationary PIT tag interrogation systems in streams

    Science.gov (United States)

    Connolly, Patrick J.; Wolf, Keith; O'Neal, Jennifer S.

    2010-01-01

    With increasing use of passive integrated transponder (PIT) tags and reliance on stationary PIT tag interrogation systems to monitor fish populations, guidelines are offered to inform users how best to use limited funding and human resources to create functional systems that maximize a desired level of detection and precision. The estimators of detection efficiency and their variability as described by Connolly et al. (2008) are explored over a span of likely performance metrics. These estimators were developed to estimate detection efficiency without relying on a known number of fish passing the system. I present graphical displays of the results derived from these estimators to show the potential efficiency and precision to be gained by adding an array or by increasing the number of PIT-tagged fish expected to move past an interrogation system.

  5. The electromagnetic integrated demonstration at the Idaho National Engineering Laboratory cold test pit

    International Nuclear Information System (INIS)

    Pellerin, L.; Alumbaugh, D.L.; Pfeifer, M.C.

    1997-01-01

    The electromagnetic integrated demonstration (EMID) is a baseline study in electromagnetic (EM) exploration of the shallow subsurface (< 10 m). Eleven distinct EM systems, covering the geophysical spectrum, acquired data on a grid over the Idaho National Engineering Laboratory (INEL) Cold Test Pit (CTP). The systems are investigated and evaluated for the purpose of identifying and reviewing existing geophysical characterization instrumentation (commercial and experimental), integrating those technologies with multi-dimensional interpretational algorithms, and identifying gaps in shallow subsurface EM imaging technology. The EMID data, are valuable for testing and evaluating new interpretational software, and developing techniques for integrating multiple datasets. The experimental field techniques shows how the acquisition of data in a variety of array configurations can considerably enhance interpretation. All data are available on the world wide web. Educators and students are encouraged to use the data for both classroom and graduate studies. The purpose of this paper is to explain why, where, how and what kind of data were collected. It is left to the reader to assess the value of a given system for their particular application. Information about the EMID is organized into two general categories: survey description and system evaluation

  6. Lessons Learned from Pit Viper Integration into Hanford Tank Farm Reality

    International Nuclear Information System (INIS)

    Catalan, Michael A.; Bailey, Sharon A.; Alzheimer, James M.; Niebuhr, Daniel P.

    2002-01-01

    The Pit Viper is a tele-operated system intended to enhance worker safety while simultaneously improving the efficiency of pit operations at the Hanford Site. Commercial off-the-shelf (COTS) components were used in an attempt to increase system efficiency. During preparation for initial deployment, the Pit Viper team identified multiple areas where more advanced technology offers substantial improvement in system capabilities. The team also ensured that the system as is, was capable of fulfilling its mission. However, there are valid concerns of the reliability of the technology. Areas where improvement are desired include; operator feedback, manipulator dexterous envelope, and system reliability

  7. Integration of OHS into Risk Management in an Open-Pit Mining Project in Quebec (Canada

    Directory of Open Access Journals (Sweden)

    Adel Badri

    2011-09-01

    Full Text Available Despite undeniable progress, the mining industry remains the scene of serious accidents revealing disregard for occupational health and safety (OHS and leaving open the debate regarding the safety of its employees. The San José mine last collapse near Copiapó, Chile on 5 August 2010 and the 69-day rescue operation that followed in order to save 33 miners trapped underground show the serious consequences of neglecting worker health and safety. The aim of this study was to validate a new approach to integrating OHS into risk management in the context of a new open-pit mining project in Quebec, based on analysis of incident and accident reports, semi-structured interviews, questionnaires and collaborative field observations. We propose a new concept, called hazard concentration, based on the number of hazards and their influence. This concept represents the weighted fraction of each category of hazards related to an undesirable event. The weight of each category of hazards is calculated by AHP, a multicriteria method. The proposed approach included the creation of an OHS database for facilitating expert risk management. Reinforcing effects between hazard categories were identified and all potential risks were prioritized. The results provided the company with a rational basis for choosing a suitable accident prevention strategy for its operational activities.

  8. An algebraic perspective to single-transponder underwater navigation

    DEFF Research Database (Denmark)

    Jouffroy, Jerome; Reger, Johann

    This paper studies the position estimation of an underwater vehicle using a single acoustic transponder. The chosen estimation approach is based on nonlinear differential algebraic methods which allow to express very simply conditions for observability. These are then used in combination with an ...... with an integrator-based time-derivative estimation technique to design an algebraic estimator, which, contrary to asymptotic observers, does not require sometimes tedious convergence verification. Simple simulation results are presented to illustrate the approach....

  9. Foldable micro coils for a transponder system measuring intraocular pressure

    Energy Technology Data Exchange (ETDEWEB)

    Ullerich, S.; Schnakenberg, U. [Technische Hochschule Aachen (Germany). Inst. of Materials in Electrical Engineering 1; Mokwa, W. [Technische Hochschule Aachen (Germany). Inst. of Materials in Electrical Engineering 1]|[Fraunhofer Inst. of Microelectronic Circuits and Systems, Duisburg (Germany); Boegel, G. vom [Fraunhofer Inst. of Microelectronic Circuits and Systems, Duisburg (Germany)

    2001-07-01

    A foldable transponder system consisting of a chip and a micro coil for measuring intraocular pressure continuously is presented. The system will be integrated in the haptic of a soft artificial intraocular lens. Calculations of planar micro coils with 6 mm and 10.3 mm in diameter show the limits for planar coils with an outer diameter of 6 mm. For the realisation of the transponder system a 20 {mu}m thick coil with an outer diameter of 10.3 mm, an inner diameter of 7.7 mm, 16 turns and a gap of 20 {mu}m between the windings was selected. Measurements show a good agreement between calculated and measured values. Wireless pressure measurements were carried out showing a linear behaviour of the output signal with respect to the applied pressure. (orig.)

  10. Mode S data link transponder flight test results

    Science.gov (United States)

    1997-02-01

    The Federal Aviation Administration (FAA) William J. Hughes Technical Center is : in the unique position of having the facilities designed to test Mode S radars : and transponders. A vendor supplied an early production model of a Mode S : transponder...

  11. Active patch antennas for transponder applications

    Energy Technology Data Exchange (ETDEWEB)

    Biffi Gentili, G; Avitabile, G; Bonifacio, F; Salvador, C [Florence Univ. (Italy). Dip. di Ingegneria Elettronica

    1996-01-01

    The paper deals with two patch antenna structures that are mainly taught for short range link and non-contact identification system (RFID). The proposed antennas were developed by starting from an original concept of cross-polarization usefully applicable, in compliance with european for transponder applications are described and experimental results are reported.

  12. A comparison between three different pit and fissure sealants with regard to marginal integrity.

    Science.gov (United States)

    Fernandes, Kristlee Sabrin; Chalakkal, Paul; de Ataide, Ida de Noronha; Pavaskar, Rajdeep; Fernandes, Precylia Philo; Soni, Harleen

    2012-04-01

    THE AIM OF THIS STUDY IS TO COMPARE THE OCCURRENCE OF ENAMEL FRACTURES, SEALANT FRACTURES AND MARGINAL FISSURES AFTER PLACEMENT OF THREE SEALANTS: Helioseal F, Conseal F and Clinpro. Thirty individuals between 13 and 15 years of age, diagnosed with pit and fissure caries by visual and DIAGNOdent examination, were chosen for sealant placement on their mandibular molars. The sealants were placed at random, after which, impressions were made with polyvinyl siloxane and casts were fabricated. Dies were prepared, each of which were sputter coated with gold in order to be examined under a scanning electron microscope. The following morphologies were analyzed from dies from each of the sealant groups: Continuous margins, sealant fractures, marginal fissures and enamel fractures. After six months, they were recalled for impression making. Dies were prepared and microscopically analyzed as mentioned. Based on the time of evaluation, there were two groups: Initial group (soon after placement) and final group (after six months). Statistical analysis was done using the paired 't' test and One-way analysis of variance (ANOVA). Clinpro had the greatest fracture resistance, followed by Conseal F and Helioseal F. The occurrence of marginal fissure was found to be least with Clinpro.

  13. The application of PIT tags to measure transport of detrital coral fragments on a fringing reef: Majuro Atoll, Marshall Islands

    Science.gov (United States)

    Ford, Murray R.

    2014-06-01

    Passive integrated transponder (PIT) tags are a radio-frequency identification device widely used as a machine-readable identification tool in fisheries research. PIT tags have also been employed, to a lesser extent, to track the movement of gravel-sized clasts within fluvial and coastal systems. In this study, PIT tags were inserted into detrital coral fragments and used to establish source-sink transport pathways on a fringing reef on Majuro Atoll in the Marshall Islands. Results suggest the transport of gravel-sized material on the inter-tidal reef flat is exclusively across-reef towards the lagoon. Considerable variation in the distance travelled by fragments was observed. Fragments were largely intact and visually recognisable after almost 5 months on the reef flat. However, the branches of some recovered fragments had broken off and corallite abrasion was observed in recovered fragments. This study indicates that PIT tags are an inexpensive and powerful new addition to the suite of sediment transport and taphonomic tools for researchers working within coral reef systems.

  14. Using RFID and PIT tags to Quantify Bedload Transport in the Oregon Coast Range

    Science.gov (United States)

    Sanfilippo, J.; Lancaster, S. T.

    2017-12-01

    Introducing the methods, issues, and data collection techniques and interpretation over one water year using RFID (radio frequency identification) and PIT (passive integrated transponder) tags in Oak Creek, near Corvallis Oregon. We constructed an RFID four-antenna array that runs off of a single radiofrequency reader via a multiplexer board. Using 4 grain sizes we tagged 990 individual rocks, roughly 250 in of each four size ranges (8-16mm, 16-32mm, 32-64mm, 64-128mm). Using 12 mm and 23 mm PIT tags during 1 water year the antennas logged 477 tracer passage events. To calculate bedload transport for each size range, at each antenna, interarrival times yield count rates when combined with grain size fractions of the bed and tracer concentrations, yield bedload transport for each size class. We calculated transport rates for five events of varying magnitude and found that PIT tag RFID method under predicts transport between 1 and 3 orders of magnitude.

  15. Estimating disperser abundance using open population models that incorporate data from continuous detection PIT arrays

    Science.gov (United States)

    Dzul, Maria C.; Yackulic, Charles B.; Korman, Josh

    2017-01-01

    Autonomous passive integrated transponder (PIT) tag antenna systems continuously detect individually marked organisms at one or more fixed points over long time periods. Estimating abundance using data from autonomous antennae can be challenging, because these systems do not detect unmarked individuals. Here we pair PIT antennae data from a tributary with mark-recapture sampling data in a mainstem river to estimate the number of fish moving from the mainstem to the tributary. We then use our model to estimate abundance of non-native rainbow trout Oncorhynchus mykiss that move from the Colorado River to the Little Colorado River (LCR), the latter of which is important spawning and rearing habitat for federally-endangered humpback chub Gila cypha. We estimate 226 rainbow trout (95% CI: 127-370) entered the LCR from October 2013-April 2014. We discuss the challenges of incorporating detections from autonomous PIT antenna systems into mark-recapture population models, particularly in regards to using information about spatial location to estimate movement and detection probabilities.

  16. Integrating geological uncertainty in long-term open pit mine production planning by ant colony optimization

    Science.gov (United States)

    Gilani, Seyed-Omid; Sattarvand, Javad

    2016-02-01

    Meeting production targets in terms of ore quantity and quality is critical for a successful mining operation. In-situ grade uncertainty causes both deviations from production targets and general financial deficits. A new stochastic optimization algorithm based on ant colony optimization (ACO) approach is developed herein to integrate geological uncertainty described through a series of the simulated ore bodies. Two different strategies were developed based on a single predefined probability value (Prob) and multiple probability values (Pro bnt) , respectively in order to improve the initial solutions that created by deterministic ACO procedure. Application at the Sungun copper mine in the northwest of Iran demonstrate the abilities of the stochastic approach to create a single schedule and control the risk of deviating from production targets over time and also increase the project value. A comparison between two strategies and traditional approach illustrates that the multiple probability strategy is able to produce better schedules, however, the single predefined probability is more practical in projects requiring of high flexibility degree.

  17. Personal communications via ACTS satellite HBR transponders

    Science.gov (United States)

    Fang, Russell J. F.

    1991-01-01

    The concept of a fully meshed network of briefcase-sized terminals is presented for personal communications over Ka-band satellite transponders. In this concept, undesirable double-hop delays are avoided for voice communications. The bandwidth and power resources of the transponder are efficiently shared by users in a simple demand-assigned manner via code-division multiple access (CDMA). Voice, data, and facsimile are statistically multiplexed at each terminal. In order to minimize terminal costs, frequency-precorrected, and level-preadjusted continuous-wave tones are sent from the central network control station in each beam so that the terminals in each down-link beam can use these pilots as references for antenna acquisition and tracking, as reliable frequency sources, and as indicators of signal fade for up-link power control (ULPC). The potential CDMA 'near-far' problem due to up-link fades is mitigated by using ULPC. Quasi-burst mode transmission is employed to minimize the potential clock and pseudorandom number code synchronization.

  18. 14 CFR 99.13 - Transponder-on requirements.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Transponder-on requirements. 99.13 Section 99.13 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.13 Transponder-on...

  19. Optic Nerve Pit

    Science.gov (United States)

    ... Conditions Frequently Asked Questions Español Condiciones Chinese Conditions Optic Nerve Pit What is optic nerve pit? An optic nerve pit is a ... may be seen in both eyes. How is optic pit diagnosed? If the pit is not affecting ...

  20. A New Methodology for Open Pit Slope Design in Karst-Prone Ground Conditions Based on Integrated Stochastic-Limit Equilibrium Analysis

    Science.gov (United States)

    Zhang, Ke; Cao, Ping; Ma, Guowei; Fan, Wenchen; Meng, Jingjing; Li, Kaihui

    2016-07-01

    Using the Chengmenshan Copper Mine as a case study, a new methodology for open pit slope design in karst-prone ground conditions is presented based on integrated stochastic-limit equilibrium analysis. The numerical modeling and optimization design procedure contain a collection of drill core data, karst cave stochastic model generation, SLIDE simulation and bisection method optimization. Borehole investigations are performed, and the statistical result shows that the length of the karst cave fits a negative exponential distribution model, but the length of carbonatite does not exactly follow any standard distribution. The inverse transform method and acceptance-rejection method are used to reproduce the length of the karst cave and carbonatite, respectively. A code for karst cave stochastic model generation, named KCSMG, is developed. The stability of the rock slope with the karst cave stochastic model is analyzed by combining the KCSMG code and the SLIDE program. This approach is then applied to study the effect of the karst cave on the stability of the open pit slope, and a procedure to optimize the open pit slope angle is presented.

  1. The design and analysis of salmonid tagging studies in the Columbia Basin. Volume 2: Estimating salmonid survival with combined PIT-CWT tagging. Technical report

    International Nuclear Information System (INIS)

    Newman, K.

    1997-06-01

    Passive Integrated Transponder (PIT) tags and Coded Wire Tags (CWTs) in combination can provide information about salmonid survival that single tag releases may not. The release and recapture protocol affects which survival and recapture rates can be estimated and the precision of the estimates. For the particular case of Columbia river salmonids tagged with both PIT tags and CWTs, three different release and recapture protocols were evaluated. This report addresses the need to study the fate of salmon smolt in-river and their subsequent return as adults. Double-tagging procedures are investigated where PIT-tags would be used to provide in-river survival data during smolt outmigrations and coded-wire tags (CWT) used to provide adult return information. This report provides statistical models for the analysis of the joint data as well as recommendations on optimal tagging studies. Study costs and stress on smolt can be reduced by only PIT-tagging a subset of all the fish coded-wire-tagged, while retaining the information content and sampling precision

  2. Use of PIT tag and underwater video recording in assessing estuarine fish movement in a high intertidal mangrove and salt marsh creek

    Science.gov (United States)

    Meynecke, Jan-Olaf; Poole, Geoffrey C.; Werry, Jonathan; Lee, Shing Yip

    2008-08-01

    We assessed movement patterns in relation to habitat availability (reflected by the extent of tidal flooding) for several commercially and recreationally important species in and out of a small mangrove creek within the subtropical Burrum River estuary (25°10'S 152°37'E) in Queensland, Australia. Movement patterns of Acanthopagrus australis, Pomadasys kaakan, Lutjanus russelli and Mugil cephalus were examined between December 2006 and April 2007 using a stationary passive integrated transponder (PIT) system adapted for saline environments (30-38 ppt) and underwater digital video cameras (DVCs). This is the second known application of a stationary PIT tag system to studying fish movement in estuarine environments. The transponder system was set in place for 104 days and recorded >5000 detections. Overall 'recapture' rate of tagged fish by the transponder system was >40%. We used PIT tags implanted in a total of 75 fish from a tidal creek connected to the main channel of the estuary. We also developed a high-resolution digital elevation (2.5 m cell size) model of the estuary derived from airborne light detection and ranging (LIDAR) and aerial imagery to estimate inundation dynamics within the tidal creek, and related the timing of inundation in various habitats to the timing of fish immigration to and emigration from the creek. Over 50% of all tagged fish were moving in and out of the creek at a threshold level when 50% of the mangrove forest became flooded. Individuals of all four species moved into and out of the tidal creek repeatedly at different times depending on species and size, indicating strong residential behaviour within the estuary. The main activity of fishes was at night time. Manual interpretation of video from >700 fish sightings at three different mangrove sites confirmed the findings of the stationary PIT system, that the function of shelter vs food in mangrove habitat may be size dependent. Our established techniques assess the spatial ecology

  3. Implantable microchip transponders for body temperature measurements in pigs

    DEFF Research Database (Denmark)

    Lohse, Louise; Uttenthal, Åse; Enøe, Claes

    thermometer. This work, however, can be quite time consuming and laborious, and further compromising the immediate well-fare of the pig, when restraining of the individual animal is necessary. Therefore, an electronic body monitoring system using implantable microchip transponders for measuring peripheral...... body temperature was tested, in order to evaluate the utility and reliability of this tool, in domestic pigs. The system is presently used and well optimized in small laboratory animals [1, 2]. We tested the microchip transponders during experimental infection of pigs with classical swine fever virus...... microchip transponder was injected deep subcutaneously by the left ear base of each individual. The transponder was before insertion programmed with ID identical to the individual pig’s ear tag number. The pigs were randomly divided into 3 groups: one group placebo-infected and two groups virus...

  4. PIT-tagged particle study of bed mobility in a Maine salmon river impacted by logging activities

    Science.gov (United States)

    Thompson, D. M.; Fixler, S. A.; Roberts, K. E.; McKenna, M.; Marshall, A. E.; Koenig, S.

    2017-12-01

    Presenting an interim report on a study on the Narraguagus River in Maine, which utilizes laser total stations cross-sectional surveys and tracking of passive integrated transponder (PIT) tags embedded in glass spheres to document changes in channel-bed characteristics associated with large wood (LW) additions and natural spawning activities. In 2016, work was initiated to monitor changes in bed elevation and sediment mobility with the addition of LW to the Narraguagus River as part of a restoration effort. Ten cross-sections, spaced 5-m apart, were established and surveyed with a laser total station in each of three different study reaches. The study sites include a control reach, a section with anticipated spawning activities and a site with ongoing LW placement. A grid of 200 glass spheres embedded with PIT tags, with twenty alternating 25-mm and 40-mm size particles equally spaced along each of the ten transects, were placed to serve as point sensors to detect sediment mobilization within each reach. In 2017, the site was revisited to determine if differences in PIT-tagged tracer particle mobilization reflect locations were LW was added and places where Atlantic salmon (Salmo salar) and sea lamprey (Petromyzon marinus) construct spawning redds. The positions of PIT-tagged tracer particles was recorded, but particles were not disturbed or uncovered to permit study of potential reworking of buried tracer particles the following year. Full tracer particle recovery will be determined in 2018 to determine if depths of tracer burial and changes in bed elevation vary among places near redds, LW and main channel locations. The data will be used to determine if salmon redds are preferentially located in either places with greater evidence of sediment reworking or alternatively in stable areas? The study will help determine the degree of bed disruption associated with spawning activities and whether LW placement encourages similar sediment mobilization processes.

  5. TDRSS multimode transponder program. Phase 2: Equipment development

    Science.gov (United States)

    Cnossen, R. S.

    1974-01-01

    This report contains a complete description of the TDRS Multimode Transponder and its associated ground support equipment. The transponder will demonstrate candidate modulation techniques to provide the required information for the design of an eventual VHF/UHF transponder suitable for installation in a user satellite, capable of operating as part of a Tracking and Data Relay Satellite (TDRS) systems. Use of geosynchronous TDRS which can serve both low data rate users at VHF and high data rate users at other frequencies has been considered. The effects of radio frequency interference from the earth and of multipath propagation due to reflections from the earth are expected to pose problems for the TDRS system at VHF. Investigations have suggested several modulation techniques that offer promise to overcome these problems.

  6. International business communications via Intelsat K-band transponders

    Science.gov (United States)

    Hagmann, W.; Rhodes, S.; Fang, R.

    This paper discusses how the transponder throughput and the required earth station HPA power in the Intelsat Business Services Network vary as a function of coding rate and required fade margin. The results indicate that transponder throughputs of 40 to 50 Mbit/s are achievable. A comparison of time domain simulation results with results based on a straightforward link analysis shows that the link analysis results may be fairly optimistic if the satellite traveling wave tube amplifier (TWTA) is operated near saturation; however, there is good agreement for large backoffs.

  7. Pit Water Storage Ottrupgaard

    DEFF Research Database (Denmark)

    Heller, Alfred

    2000-01-01

    The pit water storage, a seasonal thermal storage, was built in 1993 with floating lid and hybrid clay-polymer for pit lining. The storage was leaking severe and solutions were to be found. In the paper solutions for pit lining and floating lids are discussed, cost estimations given and coming...

  8. 78 FR 69318 - Airworthiness Directives; Rockwell Collins, Inc. Transponders

    Science.gov (United States)

    2013-11-19

    ... We invite you to send any written relevant data, views, or arguments about this proposal. Send your... with the transponders that could lead to increased pilot and air traffic controller workload as well as..., certificated in any category: (i) Airbus Models A319, A320, A330, A340; and (ii) Boeing Models B777, B747, MD...

  9. Crotaline Fab antivenom appears to be effective in cases of severe North American pit viper envenomation: An integrative review

    Directory of Open Access Journals (Sweden)

    Mlynarchek Sara L

    2009-06-01

    Full Text Available Abstract Background In 2000, the United States Food and Drug Administration approved Crotalidae Polyvalent Immune Fab (Ovine (hereafter, FabAV, "for the management of patients with minimal to moderate North American Crotalid envenomation." Because whole-IgG pit viper antivenom is no longer available in the United States, FabAV is currently the only specific treatment option available to United States clinicians treating snakebite victims of any severity. No clinical trial data are available concerning the effectiveness of FabAV for treatment of severe snakebite, but several published articles describe its use in this setting. Methods We performed a comprehensive review of the English-language medical literature to identify all publications (1996 to July, 2008 containing data about the administration of FabAV. Two trained reviewers separately extracted case-level data concerning the administration of FabAV to patients with severe envenomation by North American crotaline snakes to a standardized form. Descriptive statistics were used. In addition, we hand-searched the US National Poison Data System reports for the years 2000–2006 to identify and describe any reports of death that occurred after FabAV administration. Results The literature review found 147 unique publications regarding FabAV. Twenty-four evaluable cases of severe human envenomation treated with FabAV were identified in 19 publications. Seven cases were described in five cohort studies, and 17 cases were described in 14 single patient case reports or non-cohort case series. Sixty-five specific severe venom effects were reported in these 24 patients, of which 50 effects (77% improved or resolved after FabAV therapy. Initial control of all severe venom effects was achieved in 12 patients (50%. The rate at which initial control was achieved was significantly higher among patients reported in the cohort series than in the case series and non-cohort reports (100% vs. 29%, P = 0

  10. A radioisotope-powered surface acoustic wave transponder

    International Nuclear Information System (INIS)

    Tin, S; Lal, A

    2009-01-01

    We demonstrate a 63 Ni radioisotope-powered pulse transponder that has a SAW (surface acoustic wave) device as the frequency transmission frequency selector. Because the frequency is determined by a SAW device, narrowband detection with an identical SAW device enables the possibility for a long-distance RF-link. The SAW transponders can be buried deep into structural constructs such as steel and concrete, where changing batteries or harvesting vibration or EM energy is not a reliable option. RF-released power to radioisotope- released power amplification is 10 8 , even when regulatory safe amounts of 63 Ni are used. Here we have achieved an 800 µW pulse (315 MHz, 10 µs pause) across a 50 Ω load every 3 min, using a 1.5 milli-Ci 63 Ni source

  11. Novel Use of PIT Tags in Sea Cucumbers: Promising Results with the Commercial Species Cucumaria frondosa.

    Directory of Open Access Journals (Sweden)

    Bruno L Gianasi

    Full Text Available The lack of a reliable and innocuous mark-recapture method has limited studies that would provide essential information for the management of commercial sea cucumbers. Tagging sea cucumbers is notoriously difficult because of their plastic nature and autolysis capacities. The markers that have so far been tested, mainly on or through the body wall, were either lost rapidly or had major drawbacks (e.g. suitable only for batch identification, requiring complex analysis, causing infections, necrosis, behavioural changes and mortality. The present study explored the efficacy of passive integrated transponder (PIT tags for individually marking sea cucumbers by assessing retention rates and long-term side effects of tags inserted in previously unstudied tissues/organs. Individuals of the species Cucumaria frondosa were tagged in the body wall, aquapharyngeal bulb and at the base of the oral tentacles. They were monitored closely for evidence of stress, infection, change in feeding and spawning behaviour and tag retention rate. Implanting the tag in an oral tentacle to reach the hydrovascular system of the aquapharyngeal bulb achieved the best retention rates in full-size individuals: from a maximum of 92% after 30 days to 68% at the end of the experimental period (300 days. Efficacy was lower in smaller individuals (84% after 30 d and 42% after 300 d. Following a slight increase in cloacal movements for 15 h post tagging, no side effect was noted in sea cucumbers tagged in the aquapharyngeal bulb via the tentacles. Feeding and spawning behaviours were not affected and no signs of infections or abnormal cell development in the vicinity of the tags were observed. This study indicates that marking sea cucumbers with 8.2 mm long PIT tags implanted via the oral tentacle is an effective technique, yielding relatively high retention rates over long periods without any detectable physiological or behavioural effects.

  12. Handling equipment Selection in open pit mines by using an integrated model based on group decision making

    Directory of Open Access Journals (Sweden)

    Abdolreza Yazdani-Chamzini

    2012-10-01

    Full Text Available Process of handling equipment selection is one of the most important and basic parts in the project planning, particularly mining projects due to holding a high charge of the total project's cost. Different criteria impact on the handling equipment selection, while these criteria often are in conflicting with each other. Therefore, the process of handling equipment selection is a complex and multi criteria decision making problem. There are a variety of methods for selecting the most appropriate equipment among a set of alternatives. Likewise, according to the sophisticated structure of the problem, imprecise data, less of information, and inherent uncertainty, the usage of the fuzzy sets can be useful. In this study a new integrated model based on fuzzy analytic hierarchy process (FAHP and fuzzy technique for order preference by similarity to ideal solution (FTOPSIS is proposed, which uses group decision making to reduce individual errors. In order to calculate the weights of the evaluation criteria, FAHP is utilized in the process of handling equipment selection, and then these weights are inserted to the FTOPSIS computations to select the most appropriate handling system among a pool of alternatives. The results of this study demonstrate the potential application and effectiveness of the proposed model, which can be applied to different types of sophisticated problems in real problems.

  13. Transponder-aided joint calibration and synchronization compensation for distributed radar systems.

    Science.gov (United States)

    Wang, Wen-Qin

    2015-01-01

    High-precision radiometric calibration and synchronization compensation must be provided for distributed radar system due to separate transmitters and receivers. This paper proposes a transponder-aided joint radiometric calibration, motion compensation and synchronization for distributed radar remote sensing. As the transponder signal can be separated from the normal radar returns, it is used to calibrate the distributed radar for radiometry. Meanwhile, the distributed radar motion compensation and synchronization compensation algorithms are presented by utilizing the transponder signals. This method requires no hardware modifications to both the normal radar transmitter and receiver and no change to the operating pulse repetition frequency (PRF). The distributed radar radiometric calibration and synchronization compensation require only one transponder, but the motion compensation requires six transponders because there are six independent variables in the distributed radar geometry. Furthermore, a maximum likelihood method is used to estimate the transponder signal parameters. The proposed methods are verified by simulation results.

  14. Tank Riser Pit Decontamination System (Pit Viper) Return on Investment and Break-Even Analysis

    International Nuclear Information System (INIS)

    Young, Joan K.; Weimar, Mark R.; Balducci, Patrick J.; Fassbender, Linda L.; Hernandez, Melissa

    2003-01-01

    This study assessed the cost benefit of Pit Viper deployment for 80 tank farm pits between October 1, 2003 and September 30, 2012 under the technical baseline for applicable double-shell tank (DST) and single-shell tank (SST) projects. After this assessment had been completed, the U.S. Department of Energy (DOE) Richland Operations Office (RL) and Office of River Protection (ORP) published the Hanford Performance Management Plan (August 2003), which accelerated the schedule for SST retrieval. Then, DOE/CH2M HILL contract modification M064 (October 2002) and The Integrated Mission Acceleration Plan (March 2003) further accelerated SST retrieval and closure schedules. Twenty-six to 40 tanks must be retrieved by 2006. Thus the schedule for SST pit entries is accelerated and the number of SST pit entries is increased. This study estimates the return on investment (ROI) and the number of pits where Pit Viper deployment would break even or save money over current manual practices. The results of the analysis indicate a positive return on the federal investment for deployment of the Pit Viper provided it is used on a sufficient number of pits

  15. Design of Solar Harvested Semi Active RFID Transponder with Supercapacitor Storage

    OpenAIRE

    Gary Valentine; Lukas Vojtech; Marek Neruda

    2015-01-01

    This paper presents the analysis, design and manufacture of a low cost, low maintenance and long-range prototype of RFID transponder with continuous operability. A prototype of semi-active RFID transponder is produced with a range that can be extended via a DC input to allow all of the readers signal power to be reflected via backscatter modulation. The transponder is powered via solar harvested power which is selected over other energy harvesting technologies as it provides a greater energy ...

  16. Iris Transponder-Communications and Navigation for Deep Space

    Science.gov (United States)

    Duncan, Courtney B.; Smith, Amy E.; Aguirre, Fernando H.

    2014-01-01

    The Jet Propulsion Laboratory has developed the Iris CubeSat compatible deep space transponder for INSPIRE, the first CubeSat to deep space. Iris is 0.4 U, 0.4 kg, consumes 12.8 W, and interoperates with NASA's Deep Space Network (DSN) on X-Band frequencies (7.2 GHz uplink, 8.4 GHz downlink) for command, telemetry, and navigation. This talk discusses the Iris for INSPIRE, it's features and requirements; future developments and improvements underway; deep space and proximity operations applications for Iris; high rate earth orbit variants; and ground requirements, such as are implemented in the DSN, for deep space operations.

  17. 21 CFR 880.6300 - Implantable radiofrequency transponder system for patient identification and health information.

    Science.gov (United States)

    2010-04-01

    ... patient identification and health information. 880.6300 Section 880.6300 Food and Drugs FOOD AND DRUG... radiofrequency transponder system for patient identification and health information. (a) Identification. An implantable radiofrequency transponder system for patient identification and health information is a device...

  18. Pits on Ascraeus

    Science.gov (United States)

    2005-01-01

    24 September 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows collapse pits and troughs on the lower northeast flank of the giant martian volcano, Ascraeus Mons. Layers of volcanic rock are evident in some of the pit and valley walls, and boulders the size of houses and trucks that were liberated from these walls by gravity can be seen on the floors of the depressions. Location near: 13.6oN, 102.6oW Image width: width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Autumn

  19. Why do Pit-Hours outlive the Pit?

    NARCIS (Netherlands)

    S.R. Ozturk (Sait); M. van der Wel (Michel); D.J.C. van Dijk (Dick)

    2015-01-01

    markdownabstract__Abstract__ We study why a majority of trades still happen during the pit hours, i.e. when the trading pit is open, even after the pit ceased to be a liquid and informative venue. We investigate the case of 30-year U.S. Treasury futures using a ten-years-long intraday data set

  20. PIT Coating Requirements Analysis

    International Nuclear Information System (INIS)

    MINTEER, D.J.

    2000-01-01

    This study identifies the applicable requirements for procurement and installation of a coating intended for tank farm valve and pump pit interior surfaces. These requirements are intended to be incorporated into project specification documents and design media. This study also evaluates previously recommended coatings and identifies requirement-compliant coating products

  1. PIT Coating Requirements Analysis

    Energy Technology Data Exchange (ETDEWEB)

    MINTEER, D.J.

    2000-10-20

    This study identifies the applicable requirements for procurement and installation of a coating intended for tank farm valve and pump pit interior surfaces. These requirements are intended to be incorporated into project specification documents and design media. This study also evaluates previously recommended coatings and identifies requirement-compliant coating products.

  2. Pitting of 3003 aluminum

    International Nuclear Information System (INIS)

    Lee, R.

    1996-01-01

    The Advanced Photon Source is a state-of-the-art synchrotron light source. The storage ring vacuum chamber is fabricated from 6061 extruded Al. Water connections to the vacuum chambers that were fabricated from 3003 Al had developed water leaks, which were subsequently remedied after considerable investigations. Materials subjected to the pitting analysis in this study are 3003, 6061, and 6063 Al

  3. Sliceable transponders for metro-access transmission links

    Science.gov (United States)

    Wagner, C.; Madsen, P.; Spolitis, S.; Vegas Olmos, J. J.; Tafur Monroy, I.

    2015-01-01

    This paper presents a solution for upgrading optical access networks by reusing existing electronics or optical equipment: sliceable transponders using signal spectrum slicing and stitching back method after direct detection. This technique allows transmission of wide bandwidth signals from the service provider (OLT - optical line terminal) to the end user (ONU - optical network unit) over an optical distribution network (ODN) via low bandwidth equipment. We show simulation and experimental results for duobinary signaling of 1 Gbit/s and 10 Gbit/s waveforms. The number of slices is adjusted to match the lowest analog bandwidth of used electrical devices and scale from 2 slices to 10 slices. Results of experimental transmission show error free signal recovery by using post forward error correction with 7% overhead.

  4. STAR: FPGA-based software defined satellite transponder

    Science.gov (United States)

    Davalle, Daniele; Cassettari, Riccardo; Saponara, Sergio; Fanucci, Luca; Cucchi, Luca; Bigongiari, Franco; Errico, Walter

    2013-05-01

    This paper presents STAR, a flexible Telemetry, Tracking & Command (TT&C) transponder for Earth Observation (EO) small satellites, developed in collaboration with INTECS and SITAEL companies. With respect to state-of-the-art EO transponders, STAR includes the possibility of scientific data transfer thanks to the 40 Mbps downlink data-rate. This feature represents an important optimization in terms of hardware mass, which is important for EO small satellites. Furthermore, in-flight re-configurability of communication parameters via telecommand is important for in-orbit link optimization, which is especially useful for low orbit satellites where visibility can be as short as few hundreds of seconds. STAR exploits the principles of digital radio to minimize the analog section of the transceiver. 70MHz intermediate frequency (IF) is the interface with an external S/X band radio-frequency front-end. The system is composed of a dedicated configurable high-speed digital signal processing part, the Signal Processor (SP), described in technology-independent VHDL working with a clock frequency of 184.32MHz and a low speed control part, the Control Processor (CP), based on the 32-bit Gaisler LEON3 processor clocked at 32 MHz, with SpaceWire and CAN interfaces. The quantization parameters were fine-tailored to reach a trade-off between hardware complexity and implementation loss which is less than 0.5 dB at BER = 10-5 for the RX chain. The IF ports require 8-bit precision. The system prototype is fitted on the Xilinx Virtex 6 VLX75T-FF484 FPGA of which a space-qualified version has been announced. The total device occupation is 82 %.

  5. Data Link Test and Analysis System/ATCRBS Transponder Test System Technical Reference

    Science.gov (United States)

    1990-05-01

    This document references material for personnel using or making software changes : to the Data Link Test and Analysis System (DATAS) for Air Traffic Control Radar : Beacon System (ATCRBS) transponder testing and data collection. This is one of : a se...

  6. SHORT-PULSE ELECTROMAGNETIC TRANSPONDER FOR HOLE-TO-HOLE USE.

    Science.gov (United States)

    Wright, David L.; Watts, Raymond D.; Bramsoe, Erik

    1983-01-01

    Hole-to-hole observations were made through nearly 20 m of granite using an electromagnetic transponder (an active reflector) in one borehole and a single-hole short-pulse radar in another. The transponder is inexpensive, operationally simple, and effective in extending the capability of a short-pulse borehole radar system to allow hole-to-hole operation without requiring timing cables. A detector in the transponder senses the arrival of each pulse from the radar. Each pulse detection triggers a kilovolt-amplitude pulse for retransmission. The transponder 'echo' may be stronger than that of a passive reflector by a factor of as much as 120 db. The result is an increase in range capability by a factor which depends on attenuation in the medium and hole-to-hole wavepath geometry.

  7. Investigations of interference between electromagnetic transponders and wireless MOSFET dosimeters: a phantom study.

    Science.gov (United States)

    Su, Zhong; Zhang, Lisha; Ramakrishnan, V; Hagan, Michael; Anscher, Mitchell

    2011-05-01

    To evaluate both the Calypso Systems' (Calypso Medical Technologies, Inc., Seattle, WA) localization accuracy in the presence of wireless metal-oxide-semiconductor field-effect transistor (MOSFET) dosimeters of dose verification system (DVS, Sicel Technologies, Inc., Morrisville, NC) and the dosimeters' reading accuracy in the presence of wireless electromagnetic transponders inside a phantom. A custom-made, solid-water phantom was fabricated with space for transponders and dosimeters. Two inserts were machined with positioning grooves precisely matching the dimensions of the transponders and dosimeters and were arranged in orthogonal and parallel orientations, respectively. To test the transponder localization accuracy with/without presence of dosimeters (hypothesis 1), multivariate analyses were performed on transponder-derived localization data with and without dosimeters at each preset distance to detect statistically significant localization differences between the control and test sets. To test dosimeter dose-reading accuracy with/without presence of transponders (hypothesis 2), an approach of alternating the transponder presence in seven identical fraction dose (100 cGy) deliveries and measurements was implemented. Two-way analysis of variance was performed to examine statistically significant dose-reading differences between the two groups and the different fractions. A relative-dose analysis method was also used to evaluate transponder impact on dose-reading accuracy after dose-fading effect was removed by a second-order polynomial fit. Multivariate analysis indicated that hypothesis 1 was false; there was a statistically significant difference between the localization data from the control and test sets. However, the upper and lower bounds of the 95% confidence intervals of the localized positional differences between the control and test sets were less than 0.1 mm, which was significantly smaller than the minimum clinical localization resolution of 0

  8. Status of the pit disassembly and conversion facility

    International Nuclear Information System (INIS)

    Wood, Warren T.; Christensen, Lowell T.

    2000-01-01

    A planned new facility, the Pit Disassembly and Conversion Facility (PDCF), will be used to disassemble the nation's inventory of surplus nuclear weapons pits and convert the plutonium from those pits into a form suitable for storage, international inspection, and final disposition. Sized to handle 35 metric tons of plutonium from pits and other sources over its 10-year operating life, the PDCF will apply the Advanced Recovery and Integrated Extraction System (ARIES) technology. ARIES process technology has been developed at Los Alamos National Laboratory (LANL) and Lawrence Livermore National Laboratory (LLNL), and an integrated system is being demonstrated at LANL. The Los Alamos National Laboratory is the lead for technical design oversight of the PDCF. Technical data gained from the ARIES demonstrations is integral for the proper design of the PDCF

  9. A study on the applicability of implantable microchip transponders for body temperature measurements in pigs

    Directory of Open Access Journals (Sweden)

    Enøe Claes

    2010-05-01

    Full Text Available Abstract Background The applicability of an electronic monitoring system using microchip transponders for measurement of body temperatures was tested in 6-week-old conventional Danish weaners infected with classical swine fever virus (CSFV. Subcutaneous tissue temperatures obtained by the implantable transponders were compared with rectal temperatures, recorded by a conventional digital thermometer. Methods In a preliminary study, transponders were inserted subcutaneously at 6 different positions of the body of 5 pigs. The transponders positioned by the ear base provided the best correlation to rectal temperature. To test the stability of the monitoring system in a larger group of pigs, transponders were therefore inserted by the left ear base in a subsequent infection experiment with 30 pigs. Results Generally, the microchip transponders measured a subcutaneous tissue temperature, which was about 1°C lower than the rectal temperature. However, a simple linear relationship between the measures of the two methods was found. Conclusions Our study showed that the tested body monitoring system may represent a promising tool to obtain an approximate correlate of body temperatures in groups of pigs. In contrast, however, the tested system did not constitute a suitable tool to measure body temperatures of individual animals in the present pig infection experiment.

  10. Methods and apparatus for switching a transponder to an active state, and asset management systems employing same

    Science.gov (United States)

    Mickle, Marlin H. (Inventor); Jones, Alex K. (Inventor); Cain, James T. (Inventor); Hawrylak, Peter J. (Inventor); Marx, Frank (Inventor); Hoare, Raymond R. (Inventor)

    2012-01-01

    A transponder that may be used as an RFID tag includes a passive circuit to eliminate the need for an "always on" active RF receiving element to anticipate a wake-up signal for the balance of the transponder electronics. This solution allows the entire active transponder to have all circuit elements in a sleep (standby) state, thus drastically extending battery life or other charge storage device life. Also, a wake-up solution that reduces total energy consumption of an active transponder system by allowing all non-addressed transponders to remain in a sleep (standby) state, thereby reducing total system or collection energy. Also, the transponder and wake-up solution are employed in an asset tracking system.

  11. Satellite communication transponders and their reliability; Eisei tosai tsushin kiki oyobi shinraisei ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, H [NTT Wireless System Laboratories, Kanagawa (Japan)

    1994-11-01

    The Engineering Test Satellite-VI is a large composite test satellite weighing two tons to perform different communication experiments. Adoption of the multi-beam satellite communication system has made possible to increase the transmission capacity, reduce the sizes of earth stations, and utilize frequencies more effectively. This paper describes the configuration of the relaying devices mounted thereon, the newly developed circuit technologies, and their reliability. The multi-beam satellite communication system mounts a number of transponders, with the frequency bands used divided into the 2.6/2.5 GHz band between the moving body and the satellite, the 6/4 GHz band for the channels between the earth stations and the satellite, and the 30/20 GHz band for the fixed communications. These arrangements were intended to achieve large size reduction as a result of applying the integrated circuit technology. The transmitters and the receivers corresponding to each beam are connected by using the satellite switches (16 inputs {times} 12 outputs). The parts used were general purpose ones rather than those specified in the MIL standards because of their number having reached so huge. Their reliability was ensured by long-term burn-in operations. 5 refs., 6 figs., 1 tab.

  12. A voltage regulator system with dynamic bandwidth boosting for passive UHF RFID transponders

    International Nuclear Information System (INIS)

    Shen Jinpeng; Wang Xin'an; Liu Shan; Li Shoucheng; Ruan Zhengkun

    2013-01-01

    This paper presents a voltage regulator system for passive UHF RFID transponders, which contains a rectifier, a limiter, and a regulator. The rectifier achieves power by rectifying the incoming RF energy. Due to the huge variation of the rectified voltage, a limiter at the rectifier output is used to clamp the rectified voltage. In this paper, the design of a limiter circuit is discussed in detail, which can provide a stable limiting voltage with low sensitivity to temperature variation and process dispersion. The key aspect of the voltage regulator system is the dynamic bandwidth boosting in the regulator. By sensing the excess current that is bypassed in the limiter during periods of excess energy, the bias current as well as the bandwidth of the regulator are increased, the output supply voltage can recover quickly from line transients during the periods of no RF energy to a full blast of RF energy. This voltage regulator system is implemented in a 0.18 μm CMOS process. (semiconductor integrated circuits)

  13. Pitting process visualization

    Directory of Open Access Journals (Sweden)

    Michal Černý

    2010-01-01

    Full Text Available The paper describes time-domain simulation of gear pitting damage using animation program. Key frames have been used to create illusion of motion. The animation uses experimental results of high-cycle fatigue of material. The fatigue damage occurs in the nominal creep area on the side of the gear tooth sample loaded with variable-positioned Hertz pressure. By applying the force, the pressure cumulates between two convex surfaces. This phenomenon results in material damage under of curved surfaces in contact. Moreover, further damage has been registered on the surface. This is due to exceeding the elastic-plastic state limit and development of „tabs“. The tabs serve as origin of surface micro cracks powered by shear stress and enclosed grease pressure as well. This deformation and extreme pressures of Pascal law contribute to elongation and growth of the surface micro crack. Non-homogenous parts of material volume support the initialization/development of the micro cracks as well. Resulting visualization of the tooth-side fatigue damage provides clear and easy-to-understand description of the damage development process right from the micro crack initialization to the final fragmentation due to pitting degradation.

  14. Motion monitoring during a course of lung radiotherapy with anchored electromagnetic transponders. Quantification of inter- and intrafraction motion and variability of relative transponder positions

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, Daniela [German Cancer Research Center (DKFZ), Division of Medical Physics in Radiation Oncology, Heidelberg (Germany); National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg (Germany); Heidelberg University Hospital, Department of Radiation Oncology, Heidelberg (Germany); Nill, Simeon; Oelfke, Uwe [German Cancer Research Center (DKFZ), Division of Medical Physics in Radiation Oncology, Heidelberg (Germany); National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg (Germany); The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, Joint Department of Physics, London (United Kingdom); Roeder, Falk [German Cancer Research Center (DKFZ), Clinical Cooperation Unit Molecular Radiooncology, Heidelberg (Germany); University of Munich (LMU), Department of Radiation Oncology, Munich (Germany); Gompelmann, Daniela; Herth, Felix [University of Heidelberg, Pneumology and Critical Care Medicine, Thoraxklinik, Heidelberg (Germany); German Center for Lung Research, Translational Lung Research Center Heidelberg (TLRC), Heidelberg (Germany)

    2017-10-15

    Anchored electromagnetic transponders for tumor motion monitoring during lung radiotherapy were clinically evaluated. First, intrafractional motion patterns were analyzed as well as their interfractional variations. Second, intra- and interfractional changes of the geometric transponder positions were investigated. Intrafractional motion data from 7 patients with an upper or middle lobe tumor and three implanted transponders each was used to calculate breathing amplitudes, overall motion amount and motion midlines in three mutual perpendicular directions and three-dimensionally (3D) for 162 fractions. For 6 patients intra- and interfractional variations in transponder distances and in the size of the triangle defined by the transponder locations over the treatment course were determined. Mean 3D values of all fractions were up to 4.0, 4.6 and 3.4 mm per patient for amplitude, overall motion amount and midline deviation, respectively. Intrafractional transponder distances varied with standard deviations up to 3.2 mm, while a maximal triangle shrinkage of 36.5% over 39 days was observed. Electromagnetic real-time motion monitoring was feasible for all patients. Detected respiratory motion was on average modest in this small cohort without lower lobe tumors, but changes in motion midline were of the same size as the amplitudes and greater midline motion can be observed in some fractions. Intra- and interfractional variations of the geometric transponder positions can be large, so for reliable motion management correlation between transponder and tumor motion needs to be evaluated per patient. (orig.) [German] Verankerte, elektromagnetische Transponder fuer die Bewegungserkennung des Tumors waehrend der Strahlentherapie der Lunge wurden klinisch evaluiert. Dafuer wurden intrafraktionelle Bewegungsmuster und ihre interfraktionellen Variationen analysiert und intra- und interfraktionelle Veraenderungen der geometrischen Transponderpositionen untersucht. Intrafraktionelle

  15. Open-pit construction

    International Nuclear Information System (INIS)

    1981-06-01

    The conceptual design of a nuclear power plant accordingly to SR 136, situated in deep open pits in rock near the brink of a plateau and accessible from above as well as horizontally from the receiving stream, was further worked out. The increased backfill covering enables the reactor building to withstand heavier external forces and higher internal pressure caused by contaminated atmosphere in the event of severe hypothetical internal accidents. The leakage of this atmosphere is to be collected in special condensation rooms and another part of it is to be cooled down in these rooms. An outer safety barrier and leakage extraction fans keep this atmosphere substantially enclosed. By that means the consequences of a core melt accident will be reduced considerably. (orig.) [de

  16. Roll-to-Roll Screen Printed Radio Frequency Identification Transponder Antennas for Vehicle Tracking Systems

    Science.gov (United States)

    Zichner, Ralf; Baumann, Reinhard R.

    2013-05-01

    Vehicle tracking systems based on ultra high frequency (UHF) radio frequency identification (RFID) technology are already introduced to control the access to car parks and corporate premises. For this field of application so-called Windshield RFID transponder labels are used, which are applied to the inside of the windshield. State of the art for manufacturing these transponder antennas is the traditional lithography/etching approach. Furthermore the performance of these transponders is limited to a reading distance of approximately 5 m which results in car speed limit of 5 km/h for identification. However, to achieve improved performance compared to existing all-purpose transponders and a dramatic cost reduction, an optimized antenna design is needed which takes into account the special dielectric and in particular metallic car environment of the tag and an roll-to-roll (R2R) printing manufacturing process. In this paper we focus on the development of a customized UHF RFID transponder antenna design, which is adopted for vehicle geometry as well as R2R screen printing manufacturing processes.

  17. A current-mode voltage regulator with an embedded sub-threshold reference for a passive UHF RFID transponder

    International Nuclear Information System (INIS)

    Liu Zhongqi; Zhang Chun; Li Yongming; Wang Zhihua

    2010-01-01

    This paper presents a current-mode voltage regulator for a passive UHF RFID transponder. The passive tag power is extracted from RF energy through the RF-to-DC rectifier. Due to huge variations of the incoming RF power, the rectifier output voltage should be regulated to achieve a stable power supply. By accurately controlling the current flowing into the load with an embedded sub-threshold reference, the regulated voltage varies in a range of 1-1.3 V from -20 to 80 0 C, and a bandwidth of about 100 kHz is achieved for a fast power recovery. The circuit is fabricated in UMC 0.18 μm mixed-mode CMOS technology, and the current consumption is only 1 μA. (semiconductor integrated circuits)

  18. A current-mode voltage regulator with an embedded sub-threshold reference for a passive UHF RFID transponder

    Energy Technology Data Exchange (ETDEWEB)

    Liu Zhongqi [Department of Electronic Engineering, Tsinghua University, Beijing 100084 (China); Zhang Chun; Li Yongming; Wang Zhihua, E-mail: liu-zq04@mails.tsinghua.edu.c [Institute of Microelectronics, Tsinghua University, Beijing 100084 (China)

    2010-06-15

    This paper presents a current-mode voltage regulator for a passive UHF RFID transponder. The passive tag power is extracted from RF energy through the RF-to-DC rectifier. Due to huge variations of the incoming RF power, the rectifier output voltage should be regulated to achieve a stable power supply. By accurately controlling the current flowing into the load with an embedded sub-threshold reference, the regulated voltage varies in a range of 1-1.3 V from -20 to 80 {sup 0}C, and a bandwidth of about 100 kHz is achieved for a fast power recovery. The circuit is fabricated in UMC 0.18 {mu}m mixed-mode CMOS technology, and the current consumption is only 1 {mu}A. (semiconductor integrated circuits)

  19. Integrated Water Basin Management Including a Large Pit Lake and a Water Supply Reservoir: The Mero-Barcés Basin

    Science.gov (United States)

    Delgado, Jordi; Juncosa-Rivera, Ricardo; Hernández-Anguiano, Horacio; Muñoz-Ibáñez, Andrea

    2016-04-01

    Water resource managers attempt to minimize conflicts among users, preserve the environment as much as possible, and satisfy user necessities at a minimum cost. Several European directives indirectly address mine restoration policies, with a goal of minimizing negative impacts and adding social and environmental value where possible. Water management must consider water sources, ecological flows, flood control, and variability in the demands for urban, industrial, and agricultural uses. In the context of the present study, the city of A Coruña is located in Galicia (NW Spain). The water supply system for this city and surrounding municipalities (~400.000 inhabitants) is based on the Abegondo-Cecebre reservoir. In cases when precipitation is scarce (e.g. no rain for more than seven consecutive months) and there is a seasonal increase in demand significantly stress the supply system so that, as occurred in 2010, shortages and water supply restrictions need to be considered. This is a clear indication of that, at present, the Abegondo-Cecebre reservoir has not enough capacity to cope with a scenario of increasing water demand (due to the vegetative and seasonal increase of population) and hydric stress likely connected with the widely acknowledged climate change. In the present context of monetary resources scarcity and society concern with respect large new public work projects, the construction of a new dam is challenging. However the opportunity provided by the recent flooding of the Meirama open pit (a large mine void that has been forced-flooded for its reclamation and it is located in the headwaters of one of the rivers draining towards the Abegondo-Cecebre reservoir) proves to be a significant new asset that will help to improve the future water management scenarios under the acknowledged uncertain conditions. In this study we have studied in detail the hydrochemistry of the affected systems (lake, river and reservoir) in order to make clear whether or not the

  20. pitting corrosion susceptibility pitting corrosion susceptibility of aisi

    African Journals Online (AJOL)

    eobe

    2DEPARTMENT OF MECHANICAL ENGINEERING, UNIVERSITY OF BENIN, BENIN- CITY, EDO STATE, NIGERIA. E-mail addresses: ... fluids and aggressive chemicals. Pitting corrosion ... the kitchen, food manufacturing and dispensing and.

  1. A predictive approach to fitness-for-service assessment of pitting corrosion

    International Nuclear Information System (INIS)

    Shekari, Elahe; Khan, Faisal; Ahmed, Salim

    2016-01-01

    Pitting corrosion is a localized corrosion that often causes leak and failure of process components. The aim of this work is to present a new fitness-for-service (FFS) assessment methodology for process equipment to track and predict pitting corrosion. In this methodology, pit density is modeled using a non-homogenous Poisson process and induction time for pit initiation is simulated as the realization of a Weibull process. The non-homogenous Markov process is used to estimate maximum pit depth, considering that only the current state of the damage influences its future development. Subsequently, the distributions of the operating pressure and the estimated burst pressure of the defected component are integrated with Monte Carlo simulations and First Order Second Moment (FOSM) method to calculate the reliability index and probability of failure. This methodology provides a more realistic failure assessment and enables consideration of uncertainty associated with estimating pit characteristics. The practical application of the proposed model is demonstrated using a piping case study. - Highlights: • A new model to estimate maximum pit depth and pit density as two main pit characteristics. • Integrating maximum pit depth with failure analysis considering allowable pressure of defected component. • Time dependent failure analysis to determine the remaining life.

  2. Single pit propagation on austenitic stainless steel

    International Nuclear Information System (INIS)

    Heurtault, Stephane

    2016-01-01

    The electrochemical characterization of metastable events such as pitting corrosion of stainless steel in chloride electrolyte remains complex because many individual processes may occur simultaneously on the alloy surface. To overcome these difficulties, an experimental setup, the flow micro-device, has been developed to achieve the initiation of a single pit and to propagate the single pit in three dimensions. In this work, we take advantage of such a device in order to revisit the pitting process on a 316L stainless steel in a chloride - sulphate bulk. In a first step, the time evolution of the pit geometry (depth, radius) and the chemical evolution of the pit solution investigated using in situ Raman spectroscopy have shown that the pit depth propagation depends on the formation of a metal chloride and sulphate gel in the pit solution, and is controlled by the metallic cations diffusion from the pit bottom to the pit mouth. The pit radius growth is defined by the initial surface de-passivation, by the presence of a pit cover and by the gel development in the solution. all of these phenomena are function of applied potential and chemical composition of the solution. In a last step, it was demonstrated that a critical chloride concentration is needed in order to maintain the pit propagation. This critical concentration slightly increases with the pit depth. From statistical analysis performed on identical experiments, a zone diagram showing the pit stability as a function of the chloride concentration and the pit dimensions was built. (author) [fr

  3. Assessing the Performance of In-Stream Restoration Projects Using Radio Frequency Identification (RFID Transponders

    Directory of Open Access Journals (Sweden)

    Bruce MacVicar

    2015-10-01

    Full Text Available Instream channel restoration is a common practice in river engineering that presents a challenge for research. One research gap is the development of monitoring techniques that allow for testable predictions of sediment transport and supply. Here we use Radio Frequency Identification (RFID transponders to compare the short-term (1-year sediment transport response to flood events in a restored and a control reach. The field site is Wilket Creek, an enlarged creek in a fully urbanized catchment without stormwater management control in Toronto, Ontario. The responses to three flooding periods, each of which are at or above the design bankfull discharge, are described. Key results are that (i particle mobility is lower in the restored reach for all three periods; (ii full mobility occurs in the control reach during the first two floods while partial mobility occurs in the restored reach; and (iii the constructed morphology exerted a controlling influence on particle entrainment, with higher mobility in the pools. Log-transformed travel distances exhibit normal distributions when grouped by particle size class, which allows a statistical comparison with power law and other predictive travel-distance relations. Results show that three bedload transport conditions can occur, with partial mobility associated with a mild relation between particle size and travel distance and full mobility associated with either a flat or steep relation depending on the degree of integration of particles in the bed. Recommendations on seeding strategy and sample sizes are made to improve the precision of the results by minimizing confidence intervals for mobility and travel distances. Even in a short term study, the RFID sediment tracking technique allows a process-based assessment of stream restoration outcomes that can be used to justify the instream intervention and plan future attempts to stabilize and enhance the system.

  4. Radar transponder operation with compensation for distortion due to amplitude modulation

    Science.gov (United States)

    Ormesher, Richard C [Albuquerque, NM; Tise, Bertice L [Albuquerque, NM; Axline, Jr., Robert M.

    2011-01-04

    In radar transponder operation, a variably delayed gating signal is used to gate a received radar pulse and thereby produce a corresponding gated radar pulse for transmission back to the source of the received radar pulse. This compensates for signal distortion due to amplitude modulation on the retransmitted pulse.

  5. Signal processing issues for the exploitation of pulse-to-pulse encoding SAR transponders

    DEFF Research Database (Denmark)

    Merryman Boncori, John Peter; Schiavon, Giovanni

    2008-01-01

    -encoding point scatterers and distributed ones. A time-domain processing algorithm and a code synchronization procedure are proposed and validated on simulated data and on a European Remote Sensing Satellite-2 data set containing prototypes of such a device. The interaction of the transponder signal with terrain...

  6. A zero power harmonic transponder sensor for ubiquitous wireless μL liquid-volume monitoring

    Science.gov (United States)

    Huang, Haiyu; Chen, Pai-Yen; Hung, Cheng-Hsien; Gharpurey, Ranjit; Akinwande, Deji

    2016-01-01

    Autonomous liquid-volume monitoring is crucial in ubiquitous healthcare. However, conventional approach is based on either human visual observation or expensive detectors, which are costly for future pervasive monitoring. Here we introduce a novel approach based on passive harmonic transponder antenna sensor and frequency hopping spread spectrum (FHSS) pattern analysis, to provide a very low cost wireless μL-resolution liquid-volume monitoring without battery or digital circuits. In our conceptual demonstration, the harmonic transponder comprises of a passive nonlinear frequency multiplier connected to a metamaterial-inspired 3-D antenna designed to be highly sensitive to the liquid-volume within a confined region. The transponder first receives some FHSS signal from an interrogator, then converts such signal to its harmonic band and re-radiates through the antenna sensor. The harmonic signal is picked up by a sniffer receiver and decoded through pattern analysis of the high dimensional FHSS signal strength data. A robust, zero power, absolute accuracy wireless liquid-volume monitoring is realized in the presence of strong direct coupling, background scatters, distance variance as well as near-field human-body interference. The concepts of passive harmonic transponder sensor, metamaterial-inspired antenna sensor, and FHSS pattern analysis based sensor decoding may help establishing cost-effective, energy-efficient and intelligent wireless pervasive healthcare monitoring platforms.

  7. Monitoring of Non-Linear Ground Movement in an Open Pit Iron Mine Based on an Integration of Advanced DInSAR Techniques Using TerraSAR-X Data

    Directory of Open Access Journals (Sweden)

    José Claudio Mura

    2016-05-01

    Full Text Available This work presents an investigation to determine ground deformation based on an integration of DInSAR Time-Series (DTS and Persistent Scatterer Interferometry (PSI techniques aiming at detecting high rates of linear and non-linear ground movement. The combined techniques were applied in an open pit iron mine located in Carajás Mineral Province (Brazilian Amazon region, using a set of 33 TerraSAR-X-1 images acquired from March 2012 to April 2013 when, due to a different deformation behavior during the dry and wet seasons in the Amazon region, a non-linear deformation was detected. The DTS analysis was performed on a stack of multi-look unwrapped interferograms using an extension of the SVD (Singular Value Decomposition, where a set of additional weighted constraints on the acceleration of the displacement was incorporated to control the smoothness of the time-series solutions, whose objective was to correct the atmospheric phase artifacts. The height errors and the deformation history provided by the DTS technique were used as previous information to perform the PSI analysis. This procedure improved the capability of the PSI technique to detect non-linear movement as well as to increase the numbers of point density of the final results. The results of the combined techniques are presented and compared with total station/prisms and ground-based radar (GBR measurements.

  8. Evaluation of pain and inflammation associated with hot iron branding and microchip transponder injection in horses.

    Science.gov (United States)

    Lindegaard, Casper; Vaabengaard, Dorte; Christophersen, Mogens T; Ekstøm, Claus T; Fjeldborg, Julie

    2009-07-01

    To compare effects of hot iron branding and microchip transponder injection regarding aversive behavioral reactions indicative of pain and inflammation in horses. 7 adult horses. In a randomized controlled clinical crossover study, behavioral reactions to hot iron branding and microchip transponder injection were scored by 4 observers. Local and systemic inflammation including allodynia were assessed and compared by use of physiologic and biochemical responses obtained repeatedly for the 168-hour study period. Serum cortisol concentration was measured repeatedly throughout the first 24 hours of the study. Sham treatments were performed 1 day before and 7 days after treatments. Hot iron branding elicited a significantly stronger aversive reaction indicative of pain than did microchip transponder injection (odds ratio [OR], 12.83). Allodynia quantified by means of skin sensitivity to von Frey monofilaments was significantly greater after hot iron branding than after microchip transponder injection (OR, 2.59). Neither treatment induced signs of spontaneously occurring pain that were observed during the remaining study period, and neither treatment induced increased serum cortisol concentrations. Comparison with sham treatments indicated no memory of an unpleasant event. The hot iron branding areas had significantly increased skin temperature and swelling (OR, 14.6). Systemic inflammation as measured via serum amyloid A concentration was not detected after any of the treatments. Microchip transponder injection induced less signs of pain and inflammation and did not seem to pose a higher long-term risk than hot iron branding. Consequently, results indicated that hot iron branding does inflict more pain and should be abandoned where possible.

  9. Stochastic modeling of pitting corrosion: A new model for initiation and growth of multiple corrosion pits

    International Nuclear Information System (INIS)

    Valor, A.; Caleyo, F.; Alfonso, L.; Rivas, D.; Hallen, J.M.

    2007-01-01

    In this work, a new stochastic model capable of simulating pitting corrosion is developed and validated. Pitting corrosion is modeled as the combination of two stochastic processes: pit initiation and pit growth. Pit generation is modeled as a nonhomogeneous Poisson process, in which induction time for pit initiation is simulated as the realization of a Weibull process. In this way, the exponential and Weibull distributions can be considered as the possible distributions for pit initiation time. Pit growth is simulated using a nonhomogeneous Markov process. Extreme value statistics is used to find the distribution of maximum pit depths resulting from the combination of the initiation and growth processes for multiple pits. The proposed model is validated using several published experiments on pitting corrosion. It is capable of reproducing the experimental observations with higher quality than the stochastic models available in the literature for pitting corrosion

  10. Stochastic modeling of pitting corrosion: A new model for initiation and growth of multiple corrosion pits

    Energy Technology Data Exchange (ETDEWEB)

    Valor, A. [Facultad de Fisica, Universidad de La Habana, San Lazaro y L, Vedado, 10400 Havana (Cuba); Caleyo, F. [Departamento de Ingenieria, Metalurgica, IPN-ESIQIE, UPALM Edif. 7, Zacatenco, Mexico DF 07738 (Mexico)]. E-mail: fcaleyo@gmail.com; Alfonso, L. [Departamento de Ingenieria, Metalurgica, IPN-ESIQIE, UPALM Edif. 7, Zacatenco, Mexico DF 07738 (Mexico); Rivas, D. [Departamento de Ingenieria, Metalurgica, IPN-ESIQIE, UPALM Edif. 7, Zacatenco, Mexico DF 07738 (Mexico); Hallen, J.M. [Departamento de Ingenieria, Metalurgica, IPN-ESIQIE, UPALM Edif. 7, Zacatenco, Mexico DF 07738 (Mexico)

    2007-02-15

    In this work, a new stochastic model capable of simulating pitting corrosion is developed and validated. Pitting corrosion is modeled as the combination of two stochastic processes: pit initiation and pit growth. Pit generation is modeled as a nonhomogeneous Poisson process, in which induction time for pit initiation is simulated as the realization of a Weibull process. In this way, the exponential and Weibull distributions can be considered as the possible distributions for pit initiation time. Pit growth is simulated using a nonhomogeneous Markov process. Extreme value statistics is used to find the distribution of maximum pit depths resulting from the combination of the initiation and growth processes for multiple pits. The proposed model is validated using several published experiments on pitting corrosion. It is capable of reproducing the experimental observations with higher quality than the stochastic models available in the literature for pitting corrosion.

  11. Assessment of Concrete Repair Techniques for Radiologically-Contaminated Tank Farm Pump and Valve Pits

    International Nuclear Information System (INIS)

    MINTEER, D.J.

    2000-01-01

    As part of the scope of Project W-314, ''Tank Farm Restoration and Safe Operations,'' the condition of pump and valve pit walls and floors is being assessed, and repairs made as needed, to support upgrading the infrastructure necessary to safely transfer tank waste for treatment. Flaws in the surfaces of the pits (e.g., concrete crack/faults, protective coating deterioration) must be repaired to ensure containment integrity and to facilitate future decontamination of the pits. This engineering study presents a cost/risk/benefit evaluation of concrete and protective coating repair methods in pump and valve pits using various manual and remote tool systems

  12. Open pit mining of uranium

    International Nuclear Information System (INIS)

    Wood, J.T.

    1977-01-01

    The Jackpile--Paquate Mines of the Anaconda Company are on the Laguna Indian Reservation midway between Grants and Albuquerque, New Mexico. The open pit mining of uranium ore at those mines is conducted in three separate operations (stripping, mining, and ore haul)

  13. Detection of Pitting in Gears Using a Deep Sparse Autoencoder

    Directory of Open Access Journals (Sweden)

    Yongzhi Qu

    2017-05-01

    Full Text Available In this paper; a new method for gear pitting fault detection is presented. The presented method is developed based on a deep sparse autoencoder. The method integrates dictionary learning in sparse coding into a stacked autoencoder network. Sparse coding with dictionary learning is viewed as an adaptive feature extraction method for machinery fault diagnosis. An autoencoder is an unsupervised machine learning technique. A stacked autoencoder network with multiple hidden layers is considered to be a deep learning network. The presented method uses a stacked autoencoder network to perform the dictionary learning in sparse coding and extract features from raw vibration data automatically. These features are then used to perform gear pitting fault detection. The presented method is validated with vibration data collected from gear tests with pitting faults in a gearbox test rig and compared with an existing deep learning-based approach.

  14. Body temperature measurement in mice during acute illness: implantable temperature transponder versus surface infrared thermometry.

    Science.gov (United States)

    Mei, Jie; Riedel, Nico; Grittner, Ulrike; Endres, Matthias; Banneke, Stefanie; Emmrich, Julius Valentin

    2018-02-23

    Body temperature is a valuable parameter in determining the wellbeing of laboratory animals. However, using body temperature to refine humane endpoints during acute illness generally lacks comprehensiveness and exposes to inter-observer bias. Here we compared two methods to assess body temperature in mice, namely implanted radio frequency identification (RFID) temperature transponders (method 1) to non-contact infrared thermometry (method 2) in 435 mice for up to 7 days during normothermia and lipopolysaccharide (LPS) endotoxin-induced hypothermia. There was excellent agreement between core and surface temperature as determined by method 1 and 2, respectively, whereas the intra- and inter-subject variation was higher for method 2. Nevertheless, using machine learning algorithms to determine temperature-based endpoints both methods had excellent accuracy in predicting death as an outcome event. Therefore, less expensive and cumbersome non-contact infrared thermometry can serve as a reliable alternative for implantable transponder-based systems for hypothermic responses, although requiring standardization between experimenters.

  15. Experimental Stress Analysis at Railway Inspection Pit

    Directory of Open Access Journals (Sweden)

    Nicuşor Laurentiu Zaharia

    2008-10-01

    Full Text Available Railway inspection pits are used in railway halls. The purpose of inspection pits is to allow the working under the vehicle. Inspection pits can be found in locomotive depots, factories etc. The new design for a inspection pit in a railway hall involve tests in purpose of homologations the railway infrastructure. Before the homologation committee meeting, tests are made; after the test, a testing report is made which it will be part at homologation documents.

  16. Novel Particle Swarm Optimization and Its Application in Calibrating the Underwater Transponder Coordinates

    OpenAIRE

    Zheping Yan; Chao Deng; Benyin Li; Jiajia Zhou

    2014-01-01

    A novel improved particle swarm algorithm named competition particle swarm optimization (CPSO) is proposed to calibrate the Underwater Transponder coordinates. To improve the performance of the algorithm, TVAC algorithm is introduced into CPSO to present an extension competition particle swarm optimization (ECPSO). The proposed method is tested with a set of 10 standard optimization benchmark problems and the results are compared with those obtained through existing PSO algorithms, basic par...

  17. Design of Solar Harvested Semi Active RFID Transponder with Supercapacitor Storage

    Directory of Open Access Journals (Sweden)

    Gary Valentine

    2015-01-01

    Full Text Available This paper presents the analysis, design and manufacture of a low cost, low maintenance and long-range prototype of RFID transponder with continuous operability. A prototype of semi-active RFID transponder is produced with a range that can be extended via a DC input to allow all of the readers signal power to be reflected via backscatter modulation. The transponder is powered via solar harvested power which is selected over other energy harvesting technologies as it provides a greater energy density and lower cost. Solar has one major drawback in terms of providing a steady DC voltage in it needed a constant supply of sunlight. A method of power storage is proposed, and the use of a supercapacitor over a rechargeable battery is used as it has a longer lifespan due to higher recharge rates. The prototype underwent a series of experiments in various working environments and proves an effective solution in providing long lasting operability. The paper concludes the use of solar harvesting with supercapacitor storage has potential for further uses in external remote sensors used in the Internet of Things.

  18. Forecasting the impact of an 1859-caliber superstorm on geosynchronous Earth-orbiting satellites: Transponder resources

    Science.gov (United States)

    Odenwald, Sten F.; Green, James L.

    2007-06-01

    We calculate the economic impact on the existing geosynchronous Earth-orbiting satellite population of an 1859-caliber superstorm event were it to occur between 2008 and 2018 during the next solar activity cycle. From a detailed model for transponder capacity and leasing, we have investigated the total revenue loss over the entire solar cycle, as a function of superstorm onset year and intensity. Our Monte Carlo simulations of 1000 possible superstorms, of varying intensity and onset year, suggest that the minimum revenue loss could be of the order of 30 billion. The losses would be larger than this if more that 20 satellites are disabled, if future launch rates do not keep up with the expected rate of retirements, or if the number of spare transponders falls below ˜30%. Consequently, revenue losses can be significantly reduced below 30 billion if the current satellite population undergoes net growth beyond 300 units during Solar Cycle 24 and a larger margin of unused transponders is maintained.

  19. Designing a ring-VCO for RFID transponders in 0.18 μm CMOS process.

    Science.gov (United States)

    Jalil, Jubayer; Reaz, Mamun Bin Ibne; Bhuiyan, Mohammad Arif Sobhan; Rahman, Labonnah Farzana; Chang, Tae Gyu

    2014-01-01

    In radio frequency identification (RFID) systems, performance degradation of phase locked loops (PLLs) mainly occurs due to high phase noise of voltage-controlled oscillators (VCOs). This paper proposes a low power, low phase noise ring-VCO developed for 2.42 GHz operated active RFID transponders compatible with IEEE 802.11 b/g, Bluetooth, and Zigbee protocols. For ease of integration and implementation of the module in tiny die area, a novel pseudodifferential delay cell based 3-stage ring oscillator has been introduced to fabricate the ring-VCO. In CMOS technology, 0.18 μm process is adopted for designing the circuit with 1.5 V power supply. The postlayout simulated results show that the proposed oscillator works in the tuning range of 0.5-2.54 GHz and dissipates 2.47 mW of power. It exhibits a phase noise of -126.62 dBc/Hz at 25 MHz offset from 2.42 GHz carrier frequency.

  20. Experimental and theoretic investigations of thermal behavior of a seasonal water pit heat storage

    DEFF Research Database (Denmark)

    Fan, Jianhua; Huang, Junpeng; Chatzidiakos, Angelos

    Seasonal heat storages are considered essential for district heating systems because they offer flexibility for the system to integrate different fluctuating renewable energy sources. Water pit thermal storages (PTES) have been successfully implemented in solar district heating plants in Denmark....... Thermal behavior of a 75,000 m3 water pit heat storage in Marstal solar heating plant was investigated experimentally and numerically. Temperatures at different levels of the water pit storage and temperatures at different depths of the ground around the storage were monitored and analyzed. A simulation...... model of the water pit storage is built to investigate development of temperatures in and around the storage. The calculated temperatures are compared to the monitored temperatures with an aim to validate the simulation model. Thermal stratification in the water pit heat storage and its interaction...

  1. Feasibility of Electromagnetic Transponder Use to Monitor Inter- and Intrafractional Motion in Locally Advanced Pancreatic Cancer Patients

    Energy Technology Data Exchange (ETDEWEB)

    Shinohara, Eric T., E-mail: eric.t.shinohara@vanderbilt.edu [Department of Radiation Oncology, The Vanderbilt Clinic, Nashville, TN (United States); Kassaee, Alireza [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA (United States); Mitra, Nandita [Department of Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia, PA (United States); Vapiwala, Neha; Plastaras, John P. [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA (United States); Drebin, Jeff [Department of Surgery, University of Pennsylvania, Philadelphia, PA (United States); Wan, Fei [Department of Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia, PA (United States); Metz, James M. [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA (United States)

    2012-06-01

    Purpose: The primary objective of this study was to determine the feasibility of electromagnetic transponder implantation in patients with locally advanced unresectable pancreatic cancer. Secondarily, the use of transponders to monitor inter- and intrafractional motion, and the efficacy of breath holding for limiting target motion, were examined. Methods and Materials: During routine screening laparoscopy, 5 patients without metastatic disease were implanted with transponders peri-tumorally. The Calypso System's localization and tracking modes were used to monitor inter- and intrafractional motion, respectively. Intrafractional motion, with and without breath holding, was also examined using Calypso tracking mode. Results: Transponder implantation was well tolerated in all patients, with minimal migration, aside from 1 patient who expulsed a single transponder. Interfractional motion based on mean shifts from setup using tattoos/orthogonal imaging to transponder based localization from 164 treatments was significant in all dimensions. Mean shift (in millimeters), followed by the standard deviation and p value, were as follows: X-axis: 4.5 mm (1.0, p = 0.01); Y axis: 6.4 mm (1.9, p = 0.03); and Z-axis 3.9 mm (0.6, p = 0.002). Mean intrafractional motion was also found to be significant in all directions: superior, 7.2 mm (0.9, p = 0.01); inferior, 11.9 mm (0.9, p < 0.01); anterior: 4.9 mm (0.5, p = 0.01); posterior, 2.9 mm (0.5, p = 0.02); left, 2.2 mm (0.4, p = 0.02); and right, 3.1 mm (0.6, p = 0.04). Breath holding during treatment significantly decreased tumor motion in all directions. Conclusions: Electromagnetic transponder implantation appears to be safe and effective for monitoring inter- and intrafractional motion. Based on these results a larger clinical trial is underway.

  2. Feasibility of Electromagnetic Transponder Use to Monitor Inter- and Intrafractional Motion in Locally Advanced Pancreatic Cancer Patients

    International Nuclear Information System (INIS)

    Shinohara, Eric T.; Kassaee, Alireza; Mitra, Nandita; Vapiwala, Neha; Plastaras, John P.; Drebin, Jeff; Wan, Fei; Metz, James M.

    2012-01-01

    Purpose: The primary objective of this study was to determine the feasibility of electromagnetic transponder implantation in patients with locally advanced unresectable pancreatic cancer. Secondarily, the use of transponders to monitor inter- and intrafractional motion, and the efficacy of breath holding for limiting target motion, were examined. Methods and Materials: During routine screening laparoscopy, 5 patients without metastatic disease were implanted with transponders peri-tumorally. The Calypso System’s localization and tracking modes were used to monitor inter- and intrafractional motion, respectively. Intrafractional motion, with and without breath holding, was also examined using Calypso tracking mode. Results: Transponder implantation was well tolerated in all patients, with minimal migration, aside from 1 patient who expulsed a single transponder. Interfractional motion based on mean shifts from setup using tattoos/orthogonal imaging to transponder based localization from 164 treatments was significant in all dimensions. Mean shift (in millimeters), followed by the standard deviation and p value, were as follows: X-axis: 4.5 mm (1.0, p = 0.01); Y axis: 6.4 mm (1.9, p = 0.03); and Z-axis 3.9 mm (0.6, p = 0.002). Mean intrafractional motion was also found to be significant in all directions: superior, 7.2 mm (0.9, p = 0.01); inferior, 11.9 mm (0.9, p < 0.01); anterior: 4.9 mm (0.5, p = 0.01); posterior, 2.9 mm (0.5, p = 0.02); left, 2.2 mm (0.4, p = 0.02); and right, 3.1 mm (0.6, p = 0.04). Breath holding during treatment significantly decreased tumor motion in all directions. Conclusions: Electromagnetic transponder implantation appears to be safe and effective for monitoring inter- and intrafractional motion. Based on these results a larger clinical trial is underway.

  3. [Literature review of the influences on error rates when identifying equids with transponder and hot-iron branding].

    Science.gov (United States)

    Campe, Amely; Schulz, Sophia; Bohnet, Willa

    2016-01-01

    Although equids have had to be tagged with a transponder since 2009, breeding associations in Germany disagree as to which method is best suited for identification (with or without hot iron branding). Therefore, the aim of this systematic literature review was to gain an overview of how effective identification is using transponders and hot iron branding and as to which factors influence the success of identification. Existing literature showed that equids can be identified by means of transponders with a probability of 85-100%, whereas symbol brandings could be identified correctly in 78-89%, whole number brandings in 0-87% and single figures in 37-92% of the readings, respectively. The successful reading of microchips can be further optimised by a correctly operated implantation process and thorough training of the applying persons. affect identification with a scanner. The removal of transponders for manipulation purposes is virtually impossible. Influences during the application of branding marks can hardly, if at all, be standardised, but influence the subsequent readability relevantly. Therefore, identification by means of hot branding cannot be considered sufficiently reliable. Impaired quality of identification can be reduced during reading but cannot be counteracted. Based on the existing studies it can be concluded that the transponder method is the best suited of the investigated methods for clearly identifying equids, being forgery-proof and permanent. It is not to be expected that applying hot branding in addition to microchips would optimise the probability of identification relevantly.

  4. New diagnostic technology and hidden pits and fissures caries

    Directory of Open Access Journals (Sweden)

    Fabrizio Guerra

    2015-10-01

    Full Text Available The accuracy in pits and fissures caries detection is of paramount importance in dental caries primary and secondary prevention. A combination of visual examination and probing is currently the mainstay of occlusal caries diagnosis. Unfortunately, these types of inspection alone may leave a certain number of pit and fissure caries undetected. The Vista Cam iX fluorescence camera (Durr Dental, Bietigheim-Bissingen, Germany is a novel dental diagnostic tool for quantitative assessment of dental caries with high specificity for carious lesions detection. In the presented cases photographic images, representing the visual diagnostic approach, are applied as integration to VistaCam iX Proof images. A step-by-step sequence of inspection and assessment of operative treatment need is presented in a case of hidden pit and fissure caries on a permanent molar. Based on the reported case, it could be observed that VistaCam iX Proof shows promising results in hidden pits and fissures caries detection and could be considered a non-invasive examination method that facilitate the detection of early lesions and a potential diagnostic aid.

  5. Metallography of pitted aluminum-clad, depleted uranium fuel

    International Nuclear Information System (INIS)

    Nelson, D.Z.; Howell, J.P.

    1994-01-01

    The storage of aluminum-clad fuel and target materials in the L-Disassembly Basin at the Savannah River Site for more than 5 years has resulted in extensive pitting corrosion of these materials. In many cases the pitting corrosion of the aluminum clad has penetrated in the uranium metal core, resulting in the release of plutonium, uranium, cesium-137, and other fission product activity to the basin water. In an effort to characterize the extent of corrosion of the Mark 31A target slugs, two unirradiated slug assemblies were removed from basin storage and sent to the Savannah River Technology Center for evaluation. This paper presents the results of the metallography and photographic documentation of this evaluation. The metallography confirmed that pitting depths varied, with the deepest pit found to be about 0.12 inches (3.05 nun). Less than 2% of the aluminum cladding was found to be breached resulting in less than 5% of the uranium surface area being affected by corrosion. The overall integrity of the target slug remained intact

  6. Cause of pitting in beryllium

    International Nuclear Information System (INIS)

    Kershaw, R.P.

    1982-01-01

    Light microscopy, bare-film radiography, secondary ion mass spectroscopy, electron microprobe and physical testing were used to examine beryllium specimens exhibiting a stratified, pitted, pattern after chemical milling. The objective was to find the cause of this pattern. Specimens were found to have voids in excess of density specification allowances. These voids are attributed, at least in part, to the sublimation of beryllium fluoride during the vacuum hot pressing operation. The origin of the pattern is attributed to these voids and etching out of fines and associated impurities. Hot isostatic pressing with a subsequent heat treatment close residual porosity and dispersed impurities enough to correct the problem

  7. Post-pit optimization strategic alignment

    OpenAIRE

    Breed, M.F.; van Heerden, D.

    2016-01-01

    Successful development of projects or life-of-mine strategies requires an understanding of the relative sensitivity of value drivers such as grade, tonnage, energy costs, direct operational costs, and recoveries. For example, the results could vary significantly depending on the grade strategy, given a specific orebody amenable to open pitting. Pit optimization is a very powerful tool widely used in the industry to determine the pit shell with the most attractive value potential. Based on the...

  8. Computer simulation of pitting potential measurements

    International Nuclear Information System (INIS)

    Laycock, N.J.; Noh, J.S.; White, S.P.; Krouse, D.P.

    2005-01-01

    A deterministic model for the growth of single pits in stainless steel has been combined with a purely stochastic model of pit nucleation. Monte-Carlo simulations have been used to compare the predictions of this model with potentiodynamic experimental measurements of the pitting potential. The quantitative agreement between model and experiment is reasonable for both 304 and 316 stainless steel, and the effects of varying surface roughness, solution chloride concentration and potential sweep rate have been considered

  9. Spontaneous Resolution of Optic Disc Pit Maculopathy

    OpenAIRE

    Tripathy, Koushik

    2017-01-01

    I read with interest the article reporting spontaneous resolution of optic disc pit maculopathy in a boy.1 Though the presence of an optic disc pit and associated macular involvement is undoubted in the presented case, the provided optical coherence tomography (OCT) does not clearly show typical intraretinal schisis (Figure 1B)1 at multiple retinal levels which may communicate with the pit. Instead, it shows a sub-internal limiting membrane (sub-ILM) cavity. Such cavities are known to occur f...

  10. Methow and Columbia Rivers studies: summary of data collection, comparison of database structure and habitat protocols, and impact of additional PIT tag interrogation systems to survival estimates, 2008-2012

    Science.gov (United States)

    Martens, Kyle D.; Tibbits, Wesley T.; Watson, Grace A.; Newsom, Michael A.; Connolly, Patrick J.

    2014-01-01

    designed to show some initial analysis and to disseminate summary information that could potentially be used in ongoing modeling efforts by USGS, Reclamation, and University of Idaho. The second chapter documents the database of fish and habitat data collected by USGS from 2004 through 2012 and compares USGS habitat protocols to the Columbia Habitat Monitoring Program (CHaMP) protocol. The third chapter is a survival analysis of fish moving through Passive Integrated Transponder (PIT) tag interrogation systems in the Methow and Columbia Rivers. It examines the effects of adding PIT tags and/or PIT tag interrogation systems on survival estimates of juvenile steelhead and Chinook salmon.

  11. Integrated Status and Effectiveness Monitoring Program Population Estimates for Juvenile Salmonids in Nason Creek, WA ; 2008 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Matthew; Murdoch, Keely [Yakama Nation Fisheries Resource Management

    2009-07-20

    This report summarizes juvenile coho, spring Chinook, and steelhead salmon migration data collected at a 1.5m diameter cone rotary fish trap on Nason Creek during 2008; providing abundance and freshwater productivity estimates. We used species enumeration at the trap and efficiency trials to describe emigration timing and to estimate the number of emigrants. Trapping began on March 2, 2008 and was suspended on December 11, 2008 when snow and ice accumulation prevented operation. During 2008, 0 brood year (BY) 2006 coho, 1 BY2007 coho, 906 BY2006 spring Chinook, 323 BY2007 fry Chinook, 2,077 BY2007 subyearling Chinook, 169 steelhead smolts, 414 steelhead fry and 2,390 steelhead parr were trapped. Mark-recapture trap efficiency trials were performed over a range of stream discharge stages. A total of 2,639 spring Chinook, 2,154 steelhead and 12 bull trout were implanted with Passive Integrated Transponder (PIT) tags. Most PIT tagged fish were used for trap efficiency trials. We were unable to identify a statistically significant relationship between stream discharge and trap efficiency, thus, pooled efficiency estimates specific to species and trap size/position were used to estimate the number of fish emigrating past the trap. We estimate that 5,259 ({+-} 359; 95% CI) BY2006 Chinook, 16,816 ({+-} 731; 95% CI) BY2007 Chinook, and 47,868 ({+-} 3,780; 95% CI) steelhead parr and smolts emigrated from Nason Creek in 2008.

  12. Speed, Acceleration, Chameleons and Cherry Pit Projectiles

    Science.gov (United States)

    Planinsic, Gorazd; Likar, Andrej

    2012-01-01

    The paper describes the mechanics of cherry pit projectiles and ends with showing the similarity between cherry pit launching and chameleon tongue projecting mechanisms. The whole story is written as an investigation, following steps that resemble those typically taken by scientists and can therefore serve as an illustration of scientific…

  13. Burning/Rubble Pits: Environmental information document

    International Nuclear Information System (INIS)

    Huber, L.A.; Johnson, W.F.; Marine, I.W.

    1987-03-01

    The Burning/Rubble Pits, located near each of the major operating areas at the Savannah River Plant (SRP), began collecting burnable waste in 1951. The waste was incinerated monthly. All Burning/Rubble Pits are currently closed except for Burning/Rubble Pit 131-1R, which has not been backfilled but is inactive. No soil cores from the Burning/Rubble Pits have been analyzed. There are four groundwater monitoring wells located around each of the pits, which have been sampled quarterly since 1984. The closure options considered for the Burning/Rubble Pits are waste removal and closure, no waste removal and closure, and no action. Modeling calculations were made to determine the risks to human population for the three postulated closure options. An ecological assessment was conducted to predict the environmental impacts on aquatic and terrestrial biota. The relative costs for each of the closure options were estimated. An evaluation of the environmental impacts from the Burning/Rubble Pits indicates that the relative risks to human health and ecosystems for the postulated closure options are low. The ecological assessment shows that the effects of any closure activities on river water quality and wildlife would be insignificant. The cost estimates show the waste removal and closure option to be the most expensive for all of the pits. 38 refs., 35 figs., 47 tabs

  14. Stochastic modeling of inspection uncertainties and applications to pitting flaws in steam generator tubes

    International Nuclear Information System (INIS)

    Mao, D.; Yuan, X.-X.; Pandey, M.D.

    2009-01-01

    Steam generators (SG) are a major pressure retaining component of great safety significance in nuclear power plants. Due to various manufacturing, operation and maintenance activities, as well as material interaction with the surrounding chemical environment, the SG tubes have been subject to a number of degradation modes. Among them, the under-deposit pitting corrosion at outside surfaces of the SG tubes just on top of the tubesheet support plates has had a serious impact on the integrity of the SG tubes. This paper presents an advanced probabilistic model of pitting corrosion characterizing the inherent randomness of the pitting process and measurement uncertainties of the in-service inspection (ISI) data obtained from eddy current (EC) inspections. A Bayesian method based on Markov Chain Monte Carlo (MCMC) simulation is developed for estimating the model parameters. The proposed model is able to predict the actual pit number, the actual pit depth as well as the maximum pit depth, which is the main interest of the pitting corrosion model. (author)

  15. Accountability Quality Shuffler Measurements on Pits

    International Nuclear Information System (INIS)

    Rinard, P.M.

    2000-01-01

    Pits have generally been treated as accountable units that are intact if merely present and they are excluded from the more demanding nondestructive assay requirements. As pits begin to flow into disposition streams, there may be more incentive to measure the masses of their fissile components for accountability purposes. This Department of Energy Office of Safeguards and Security (OSS) Lifecycle Project has explored some ways in which such measurements may be done successfully. The active neutron instrument called a shuffler has been used to measure a variety of actual pits, and a calculational technique has been developed to accurately predict such count rates. Passive multiplicity counting has previously been applied to pits for determining their plutonium contents. This combination of measurement and calculational techniques provide powerful and accurate tools for determining the fissile contents of pits with the quality needed for accountability purposes

  16. PIT 9 Project: A private sector initiative

    International Nuclear Information System (INIS)

    Macdonald, D.W.; Hughes, F.P.; Burton, B.N.

    1993-01-01

    The Pit 9 Comprehensive Demonstration is intended to demonstrate a cost-effective approach to remediate an Idaho National Engineering Lab. (INEL) waste disposal pit through a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Interim Action. The remediation will include additional requirements, if needed, to provide high confidence that only minor additional work would be necessary to accomplish the final closure as part of the overall final closure strategy for the INEL's Subsurface Disposal Area (SDA). Pit 9 is an inactive waste disposal pit located in the northeastern corner of the SDA at the INEL's Radioactive Waste Management Complex (RWMC). It covers approximately 1 acre. The waste within Pit 9 is primarily transuranic waste generated at the Rocky Flats Plant and additional wastes, both hazardous and low-level radioactive, from generators at the INEL

  17. Pit closures - effects and alternatives

    Energy Technology Data Exchange (ETDEWEB)

    Stott, A G

    1987-02-01

    During the last decade, British Coal has closed around 100 mines. This article illustrates the effect of pit closures on the colliery's workforce, and the local community and its economy. Working conditions at Newmarket Colliery and the Selby coalfield are compared within the context of British Coal's national transfer market. British Coal's transfer benefits include resettlement payments and mortgage subsidies. The job creation venture of British Coal Enterprise Ltd. has helped to create over 3700 new jobs in 264 projects, involving a total investment of 38 M pounds sterling. The article also discusses deputies' qualifications and prospects for recently qualified management staff, and gives a comparison of losses suffered by the different mining unions.

  18. Is Playing in the Pit Really the Pits?: Pain, Strength, Music Performance Anxiety, and Workplace Satisfaction in Professional Musicians in Stage, Pit, and Combined Stage/Pit Orchestras.

    Science.gov (United States)

    Kenny, Dianna T; Driscoll, Tim; Ackermann, Bronwen J

    2016-03-01

    Typically, Australian orchestral musicians perform on stage, in an orchestra pit, or in a combination of both workplaces. This study explored a range of physical and mental health indicators in musicians who played in these different orchestra types to ascertain whether orchestra environment was a risk factor affecting musician wellbeing. Participants comprised 380 full-time orchestral musicians from the eight major state orchestras in Australia comprised of two dedicated pit orchestras, three stage-only symphonic orchestras, and three mixed stage/pit orchestras. Participants completed a physical assessment and a range of self-report measures assessing performance-related musculoskeletal disorders (PRMD), physical characteristics including strength and perceived exertion, and psychological health, including music performance anxiety (MPA), workplace satisfaction, and bullying. Physical characteristics and performance-related musculoskeletal profiles were similar for most factors on the detailed survey completed by orchestra members. The exceptions were that pit musicians demonstrated greater shoulder and elbow strength, while mixed-workload orchestra musicians had greater flexibility Significantly more exertion was reported by pit musicians when rehearsing and performing. Stage/pit musicians reported less physical exertion when performing in the pit compared with performing on stage. Severity of MPA was significantly greater in pit musicians than mixed orchestra musicians. Pit musicians also reported more frequent bullying and lower job satisfaction compared with stage musicians. There were few differences in the objective physical measures between musicians in the different orchestra types. However, pit musicians appear more psychologically vulnerable and less satisfied with their work than musicians from the other two orchestra types. The physical and psychological characteristics of musicians who perform in different orchestra types have not been adequately

  19. 78 FR 43262 - Use of Wireless Mobile Data Devices as Transponders for the Commercial Motor Vehicle Information...

    Science.gov (United States)

    2013-07-19

    ... FMCSA's regulations prohibiting texting and the use of hand-held wireless mobile phones by commercial... part 392 prohibiting texting and the use of hand-held wireless mobile phones by commercial motor vehicle (CMV) drivers. Benefits Use of wireless mobile data devices as transponders with CMRS provides...

  20. Software Modules for the Proximity-1 Space Link Interleaved Time Synchronization (PITS) Protocol

    Science.gov (United States)

    Woo, Simon S.; Veregge, John R.; Gao, Jay L.; Clare, Loren P.; Mills, David

    2012-01-01

    The Proximity-1 Space Link Interleaved Time Synchronization (PITS) protocol provides time distribution and synchronization services for space systems. A software prototype implementation of the PITS algorithm has been developed that also provides the test harness to evaluate the key functionalities of PITS with simulated data source and sink. PITS integrates time synchronization functionality into the link layer of the CCSDS Proximity-1 Space Link Protocol. The software prototype implements the network packet format, data structures, and transmit- and receive-timestamp function for a time server and a client. The software also simulates the transmit and receive-time stamp exchanges via UDP (User Datagram Protocol) socket between a time server and a time client, and produces relative time offsets and delay estimates.

  1. Cogema experience on retrieving and conditioning solid radwaste previously stored in pits. The La Hague north west pit case

    International Nuclear Information System (INIS)

    Bodin, F.; Alexandre, D.; Fournier, Ph.

    2000-01-01

    Short lived, low and medium level waste called 'technological waste' produced by the La Hague Reprocessing Plant have been stored in the La Hague North-West concrete-lined pits until implementation at ANDRA's Centre de Stockage de la Manche (CSM). COGEMA decided to retrieve and condition 11,000 m 3 of humid solid radwaste, stored in bulk in pits. This report describes the experience gained from February 1990 to December 1998, taking into account radwaste and integrated dose rate results conditioning such waste. The procedures and means used and improved by COGEMA to comply with ANDRA's storage standards and the ever-decreasing financial costs generated by the workers, allowed to retrieve and condition 11,000 m 3 of old solid radwaste with competitive costs and in complete safety and protection of the environment. (authors)

  2. Low modulation index RF signal detection for a passive UHF RFID transponder

    International Nuclear Information System (INIS)

    Liu Zhongqi; Zhang Chun; Li Yongming; Wang Zhihua

    2009-01-01

    In a typical RFID system the reader transmits modulated RF power to provide both data and energy for the passive transponder. Low modulation index RF energy is preferable for an adequate tag power supply and increase in communication range but gives rise to difficulties for near-field conventional demodulation. Therefore, a novel ASK demodulator for minimum 20% modulation index RF signal detection over a range of 23 dB is presented. Thanks to the proposed innovative divisional linear conversion from the power into voltage signal, the detection sensitivity is ensured over a wide power range with low power consumption of 8.6 μW. The chip is implemented in UMC 0.18 μm mix-mode CMOS technology, and the chip area is 0.06 mm 2 .

  3. Low modulation index RF signal detection for a passive UHF RFID transponder

    Energy Technology Data Exchange (ETDEWEB)

    Liu Zhongqi [Department of Electronic Engineering, Tsinghua University, Beijing 100084 (China); Zhang Chun; Li Yongming; Wang Zhihua, E-mail: liu-zq04@mails.tsinghua.edu.c [Institute of Microelectronics, Tsinghua University, Beijing 100084 (China)

    2009-09-15

    In a typical RFID system the reader transmits modulated RF power to provide both data and energy for the passive transponder. Low modulation index RF energy is preferable for an adequate tag power supply and increase in communication range but gives rise to difficulties for near-field conventional demodulation. Therefore, a novel ASK demodulator for minimum 20% modulation index RF signal detection over a range of 23 dB is presented. Thanks to the proposed innovative divisional linear conversion from the power into voltage signal, the detection sensitivity is ensured over a wide power range with low power consumption of 8.6 {mu}W. The chip is implemented in UMC 0.18 {mu}m mix-mode CMOS technology, and the chip area is 0.06 mm{sup 2}.

  4. Extended post processing for simulation results of FEM synthesized UHF-RFID transponder antennas

    Directory of Open Access Journals (Sweden)

    R. Herschmann

    2007-06-01

    Full Text Available The computer aided design process of sophisticated UHF-RFID transponder antennas requires the application of reliable simulation software. This paper describes a Matlab implemented extension of the post processor capabilities of the commercially available three dimensional field simulation programme Ansoft HFSS to compute an accurate solution of the antenna's surface current distribution. The accuracy of the simulated surface currents, which are physically related to the impedance at the feeding point of the antenna, depends on the convergence of the electromagnetic fields inside the simulation volume. The introduced method estimates the overall quality of the simulation results by combining the surface currents with the electromagnetic fields extracted from the field solution of Ansoft HFSS.

  5. Pitting corrosion on a copper canister

    International Nuclear Information System (INIS)

    Hermansson, H.P.; Beverskog, B.

    1996-02-01

    It is demonstrated that normal pitting can occur during oxidizing conditions in the repository. It is also concluded that a new theory for pitting corrosion has to be developed, as the present theory is not in accordance with all practical and experimental observations. A special variant of pitting, based on the growth of sulfide whiskers, is suggested to occur during reducing conditions. However, such a mechanism needs to be demonstrated experimentally. A simple calculational model of canister corrosion was developed based on the results of this study. 69 refs, 3 figs

  6. Pit disassembly and conversion demonstration environmental assessment and research and development activities

    International Nuclear Information System (INIS)

    1998-08-01

    A significant portion of the surplus plutonium is in the form of pits, a nuclear weapons component. Pits are composed of plutonium which is sealed in a metallic shell. These pits would need to be safely disassembled and permanently converted to an unclassified form that would be suitable for long-term disposition and international inspection. To determine the feasibility of an integrated pit disassembly and conversion system, a Pit Disassembly and Conversion Demonstration is proposed to take place at the Los Alamos National Laboratory (LANL). This demonstration would be done in existing buildings and facilities, and would involve the disassembly of up to 250 pits and conversion of the recovered plutonium to plutonium metal ingots and plutonium dioxide. This demonstration also includes the conversion of up to 80 kilograms of clean plutonium metal to plutonium dioxide because, as part of the disposition process, some surplus plutonium metal may be converted to plutonium dioxide in the same facility as the surplus pits. The equipment to be used for the proposed demonstration addressed in this EA would use some parts of the Advanced Recovery and Integrated Extraction System (ARIES) capability, other existing equipment/capacities, plus new equipment that was developed at other sites. In addition, small-scale R and D activities are currently underway as part of the overall surplus plutonium disposition program. These R and D activities are related to pit disassembly and conversion, MOX fuel fabrication, and immobilization (in glass and ceramic forms). They are described in Section 7.0. On May 16, 1997, the Office of Fissile Materials Disposition (MD) notified potentially affected states and tribes that this EA would be prepared in accordance with NEPA. This EA has been prepared to provide sufficient information for DOE to determine whether a Finding of No Significant Impact (FONSI) is warranted or whether an EIS must be prepared

  7. The United States pit disassembly and conversion project -- Meeting the MOX fuel specification

    International Nuclear Information System (INIS)

    Nelson, T.O.; James, C.A.; Kolman, D.G.

    1998-01-01

    The US is actively involved in demonstrating the disassembly of nuclear weapons pits to an unclassified form readied for disposition. The MOX option is the most likely path forward for plutonium that originated from nuclear weapon pits. The US demonstration line for pit disassembly and conversion is known as ARIES, the advanced recovery and integrated extraction system. The ARIES demonstration line is being used to gather data in an integrated fashion of the technologies needed for pit disassembly and conversion. These activities include the following modules: pit bisection, hydride-dehydride, oxide conversion, canning, electrolytic decontamination, and nondestructive assay (NDA). Pit bisection swages in a pit in half. Hydride-dehydride converts the pit plutonium metal to an unclassified metal button. To convert the plutonium metal to an oxide the US is investigating a number of options. The primary oxide conversion approach involves variations of combining plutonium hydriding and subsequent oxidation. Another approach is to simply oxidize the metal under controlled conditions-direct metal oxidation (DMO). To remove the gallium from the plutonium oxide, a thermal distillation approach is being used. These pyrochemical approaches will substantially reduce the wastes produced for oxide conversion of weapon plutonium, compared to traditional aqueous processing. The packaging of either the plutonium metal or oxide to long term storage criteria involves the canning and electrolytic decontamination modules. The NDA suite of instruments is then used to assay the material in the containers, which enables international verification without the need to open the containers and repackage them. All of these processes are described

  8. CHerenkov detectors In mine PitS (CHIPS) Letter of Intent to FNAL

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, P. [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Austin, J. [Univ. of Minnesota, Duluth, MN (United States); Cao, S. V. [Univ. of Texas, Austin, TX (United States); Coelho, J. A. B. [Tufts Univ., Medford, MA (United States); Davies, G. S. [Iowa State Univ., Ames, IA (United States); Evans, J. J. [Univ. of Manchester (United Kingdom); Guzowski, P. [Univ. of Manchester (United Kingdom); Habig, A. [Univ. of Minnesota, Duluth, MN (United States); Holin, A. [Univ. College London, London (United Kingdom); Huang, J. [Univ. of Texas, Austin, TX (United States); Johnson, R. [Univ. of Cincinnati, OH (United States); St. John, J. [Univ. of Cincinnati, OH (United States); Kreymer, A. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Kordosky, M. [College of William and Mary, Williamsburg, VA (United States); Lang, K. [Univ. of Texas, Austin, TX (United States); Marshak, M. L. [Univ. of Minnesota, Minneapolis, MN (United States); Mehdiyev, R. [Univ. of Texas, Austin, TX (United States); Meier, J. [Univ. of Minnesota, Minneapolis, MN (United States); Miller, W. [Univ. of Minnesota, Minneapolis, MN (United States); Naples, D. [Univ. of Pittsburgh, PA (United States); Nelson, J. K. [College of William and Mary, Williamsburg, VA (United States); Nichol, R. J. [Univ. College London, London (United Kingdom); Patterson, R. B. [California Inst. of Technology (CalTech), Pasadena, CA (United States); Paolone, V. [Univ. of Pittsburgh, PA (United States); Pawloski, G. [Univ. of Minnesota, Minneapolis, MN (United States); Perch, A. [Univ. College London, London (United Kingdom); Pfutzner, M. [Univ. College London, London (United Kingdom); Proga, M. [Univ. of Texas, Austin, TX (United States); Qian, X. [Brookhaven National Lab. (BNL), Upton, NY (United States); Radovic, A. [Univ. College London, London (United Kingdom); Sanchez, M. C. [Iowa State Univ., Ames, IA (United States); Schreiner, S. [Univ. of Minnesota, Minneapolis, MN (United States); Soldner-Rembold, S. [Univ. of Manchester (United Kingdom); Sousa, A. [Univ. of Cincinnati, OH (United States); Thomas, J. [Univ. College London, London (United Kingdom); Vahle, P. [College of William and Mary, Williamsburg, VA (United States); Wendt, C. [Univ. of Wisconsin, Madison, WI (United States); Whitehead, L. H. [Univ. College London, London (United Kingdom); Wojcicki, S. [Stanford Univ., CA (United States)

    2013-12-30

    This Letter of Intent outlines a proposal to build a large, yet cost-effective, 100 kton fiducial mass water Cherenkov detector that will initially run in the NuMI beam line. The CHIPS detector (CHerenkov detector In Mine PitS) will be deployed in a flooded mine pit, removing the necessity and expense of a substantial external structure capable of supporting a large detector mass. There are a number of mine pits in northern Minnesota along the NuMI beam that could be used to deploy such a detector. In particular, the Wentworth Pit 2W is at the ideal off-axis angle to contribute to the measurement of the CP violating phase. The detector is designed so that it can be moved to a mine pit in the LBNE beam line once that becomes operational.

  9. AHAR: Part 1 - PIT Estimates of Homelessness

    Data.gov (United States)

    Department of Housing and Urban Development — This report outlines the key findings of the 2014 Point-In-Time (PIT) and Housing Inventory (HIC) counts conducted in January 2014. Specifically, this report...

  10. Project Development Specification for Valve Pit Manifold

    International Nuclear Information System (INIS)

    MCGREW, D.L.

    2000-01-01

    Establishes the performance, design development, and test requirements for the valve pit manifolds. The system engineering approach was used to develop this document in accordance with the guidelines laid out in the Systems Engineering Management Plan for Project W-314

  11. Pitting corrosion of copper. Further model studies

    International Nuclear Information System (INIS)

    Taxen, C.

    2002-08-01

    The work presented in this report is a continuation and expansion of a previous study. The aim of the work is to provide background information about pitting corrosion of copper for a safety analysis of copper canisters for final deposition of radioactive waste. A mathematical model for the propagation of corrosion pits is used to estimate the conditions required for stationary propagation of a localised anodic corrosion process. The model uses equilibrium data for copper and its corrosion products and parameters for the aqueous mass transport of dissolved species. In the present work we have, in the model, used a more extensive set of aqueous and solid compounds and equilibrium data from a different source. The potential dependence of pitting in waters with different compositions is studied in greater detail. More waters have been studied and single parameter variations in the composition of the water have been studied over wider ranges of concentration. The conclusions drawn in the previous study are not contradicted by the present results. However, the combined effect of potential and water composition on the possibility of pitting corrosion is more complex than was realised. In the previous study we found what seemed to be a continuous aggravation of a pitting situation by increasing potentials. The present results indicate that pitting corrosion can take place only over a certain potential range and that there is an upper potential limit for pitting as well as a lower. A sensitivity analysis indicates that the model gives meaningful predictions of the minimum pitting potential also when relatively large errors in the input parameters are allowed for

  12. Pit 9 project: A private sector initiative

    International Nuclear Information System (INIS)

    Macdonald, D.W.; Hughes, F.P.; Burton, B.N.

    1993-01-01

    This report discusses the Pit 9 Comprehensive Demonstration which is intended to demonstrate a cost-effective approach to remediate an Idaho National Engineering Laboratory (INEL) waste disposal pit through a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Interim Action. The remediation will include additional requirements, if needed, to provide high confidence that only minor additional work would be necessary to accomplish the final closure as part of the overall final closure strategy for the INEL's Subsurface Disposal Area (SDA)

  13. Pitting corrosion as a mixed system: coupled deterministic-probabilistic simulation of pit growth

    Science.gov (United States)

    Ibrahim, Israr B. M.; Fonna, S.; Pidaparti, R.

    2018-05-01

    Stochastic behavior of pitting corrosion poses a unique challenge in its computational analysis. However, it also stems from electrochemical activity causing general corrosion. In this paper, a framework for corrosion pit growth simulation based on the coupling of the Cellular Automaton (CA) and Boundary Element Methods (BEM) is presented. The framework assumes that pitting corrosion is controlled by electrochemical activity inside the pit cavity. The BEM provides the prediction of electrochemical activity given the geometrical data and polarization curves, while the CA is used to simulate the evolution of pit shapes based on electrochemical activity provided by BEM. To demonstrate the methodology, a sample case of local corrosion cells formed in pitting corrosion with varied dimensions and polarization functions is considered. Results show certain shapes tend to grow in certain types of environments. Some pit shapes appear to pose a higher risk by being potentially significant stress raisers or potentially increasing the rate of corrosion under the surface. Furthermore, these pits are comparable to commonly observed pit shapes in general corrosion environments.

  14. Oxygen pitting failure of a bagasse boiler tube

    CSIR Research Space (South Africa)

    Heyes, AM

    2001-04-01

    Full Text Available Examination of a failed roof tube from a bagasse boiler showed transverse through-cracks and extensive pitting. The pitting was typically oxygen induced pitting and numerous fatigue cracks had started within these pits. It is highly probable...

  15. W-12 valve pit decontamination demonstration

    International Nuclear Information System (INIS)

    Benson, C.E.; Parfitt, J.E.; Patton, B.D.

    1995-12-01

    Waste tank W-12 is a tank in the ORNL Low-Level Liquid Waste (LLLW) system that collected waste from Building 3525. Because of a leaking flange in the discharge line from W-12 to the evaporator service tank (W-22) and continual inleakage into the tank from an unknown source, W-12 was removed from service to comply with the Federal Facilities Agreement requirement. The initial response was to decontaminate the valve pit between tank W-12 and the evaporator service tank (W-22) to determine if personnel could enter the pit to attempt repair of the leaking flange. Preventing the spread of radioactive contamination from the pit to the environment and to other waste systems was of concern during the decontamination. The drain in the pit goes to the process waste system; therefore, if high-level liquid waste were generated during decontamination activities, it would have to be removed from the pit by means other than the available liquid waste connection. Remote decontamination of W-12 was conducted using the General Mills manipulator bridge and telescoping trolley and REMOTEC RM-10 manipulator. The initial objective of repairing the leaking flange was not conducted because of the repair uncertainty and the unknown tank inleakage. Rather, new piping was installed to empty the W-12 tank that would bypass the valve pit and eliminate the need to repair the flange. The radiological surveys indicated that a substantial decontamination factor was achieved

  16. Design-only conceptual design report for pit disassembly and conversion facility. Rev 0

    International Nuclear Information System (INIS)

    Zygmunt, S.; Christensen, L.; Richardson, C.

    1997-01-01

    This design-only conceptual design report (DOCDR) was prepared to support a funding request by the Department of Energy (DOE)-Office of Fissile Material Disposition (OFMD) for engineering design of the Pit Disassembly and Conversion Facility (PDCF) Project No. 99-D-141. The PDCF will be used to disassemble the nation's inventory of surplus nuclear weapons pits and convert the plutonium recovered from those pits into a form suitable for storage, international inspection, and final disposition. The PDCF is a complex consisting of a hardened building that will contain the plutonium processes in a safe and secure manner, and conventional buildings and structures that will house support personnel, systems, and equipment. The PDCF uses the Advanced Recovery and Integrated Extraction System (ARIES), a low waste, modular pyroprocessing system to convert pits to plutonium oxide. The PDCF project consists of engineering and design, and construction of the buildings and structures, and engineering and design, procurement, installation, testing and start-up of equipment to disassemble pits and convert plutonium in pits to oxide form. The facility is planned to operate for 10 years, averaging 3.5 metric tons (3.86 tons) of plutonium metal per year. On conclusion of operations, the PDCF will be decontaminated and decommissioned

  17. Design-only conceptual design report for pit disassembly and conversion facility. Rev 0

    Energy Technology Data Exchange (ETDEWEB)

    Zygmunt, S.; Christensen, L.; Richardson, C.

    1997-12-12

    This design-only conceptual design report (DOCDR) was prepared to support a funding request by the Department of Energy (DOE)-Office of Fissile Material Disposition (OFMD) for engineering design of the Pit Disassembly and Conversion Facility (PDCF) Project No. 99-D-141. The PDCF will be used to disassemble the nation`s inventory of surplus nuclear weapons pits and convert the plutonium recovered from those pits into a form suitable for storage, international inspection, and final disposition. The PDCF is a complex consisting of a hardened building that will contain the plutonium processes in a safe and secure manner, and conventional buildings and structures that will house support personnel, systems, and equipment. The PDCF uses the Advanced Recovery and Integrated Extraction System (ARIES), a low waste, modular pyroprocessing system to convert pits to plutonium oxide. The PDCF project consists of engineering and design, and construction of the buildings and structures, and engineering and design, procurement, installation, testing and start-up of equipment to disassemble pits and convert plutonium in pits to oxide form. The facility is planned to operate for 10 years, averaging 3.5 metric tons (3.86 tons) of plutonium metal per year. On conclusion of operations, the PDCF will be decontaminated and decommissioned.

  18. A probability distribution model of tooth pits for evaluating time-varying mesh stiffness of pitting gears

    Science.gov (United States)

    Lei, Yaguo; Liu, Zongyao; Wang, Delong; Yang, Xiao; Liu, Huan; Lin, Jing

    2018-06-01

    Tooth damage often causes a reduction in gear mesh stiffness. Thus time-varying mesh stiffness (TVMS) can be treated as an indication of gear health conditions. This study is devoted to investigating the mesh stiffness variations of a pair of external spur gears with tooth pitting, and proposes a new model for describing tooth pitting based on probability distribution. In the model, considering the appearance and development process of tooth pitting, we model the pitting on the surface of spur gear teeth as a series of pits with a uniform distribution in the direction of tooth width and a normal distribution in the direction of tooth height, respectively. In addition, four pitting degrees, from no pitting to severe pitting, are modeled. Finally, influences of tooth pitting on TVMS are analyzed in details and the proposed model is validated by comparing with a finite element model. The comparison results show that the proposed model is effective for the TVMS evaluations of pitting gears.

  19. Pitting of malaria parasites and spherocyte formation

    Directory of Open Access Journals (Sweden)

    Gichuki Charity W

    2006-07-01

    Full Text Available Abstract Background A high prevalence of spherocytes was detected in blood smears of children enrolled in a case control study conducted in the malaria holoendemic Lake Victoria basin. It was speculated that the spherocytes reflect intraerythrocytic removal of malarial parasites with a concurrent removal of RBC membrane through a process analogous to pitting of intraerythrocytic inclusion bodies. Pitting and re-circulation of RBCs devoid of malaria parasites could be a host mechanism for parasite clearance while minimizing the anaemia that would occur were the entire parasitized RBC removed. The prior demonstration of RBCs containing ring-infected erythrocyte surface antigen (pf 155 or RESA but no intracellular parasites, support the idea of pitting. Methods An in vitro model was developed to examine the phenomenon of pitting and spherocyte formation in Plasmodium falciparum infected RBCs (iRBC co-incubated with human macrophages. In vivo application of this model was evaluated using blood specimens from patients attending Kisumu Ditrict Hospital. RBCs were probed with anti-RESA monoclonal antibody and a DNA stain (propidium iodide. Flow cytometry and fluorescent microscopy was used to compare RBCs containing both the antigen and the parasites to those that were only RESA positive. Results Co-incubation of iRBC and tumor necrosis factor-alpha activated macrophages led to pitting (14% ± 1.31% macrophages with engulfed trophozoites as opposed to erythrophagocytosis (5.33% ± 0.95% (P Conclusion It is proposed that in malaria holoendemic areas where prevalence of asexual stage parasites approaches 100% in children, RBCs with pitted parasites are re-circulated and pitting may produce spherocytes.

  20. Baseline Risk Assessment for the F-Area Burning/Rubble Pits and Rubble Pit

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, E. [Westinghouse Savannah River Company, AIKEN, SC (United States)

    1996-03-01

    This document provides an overview of the Savannah River Site (SRS) and a description of the F-Area Burning/Rubble Pits (BRPs) and Rubble Pit (RP) unit. It also describes the objectives and scope of the baseline risk assessment (BRA).

  1. Electromagnetic Transponders Indicate Prostate Size Increase Followed by Decrease During the Course of External Beam Radiation Therapy

    International Nuclear Information System (INIS)

    King, Benjamin L.; Butler, Wayne M.; Merrick, Gregory S.; Kurko, Brian S.; Reed, Joshua L.; Murray, Brian C.; Wallner, Kent E.

    2011-01-01

    Purpose: Real-time image guidance enables more accurate radiation therapy by tracking target movement. This study used transponder positions to monitor changes in prostate volume that may be a source of dosimetric and target inaccuracy. Methods and Materials: Twenty-four men with biopsy-proven T1c-T3a prostate cancer each had three electromagnetic transponders implanted transperineally. Their coordinates were recorded by the Calypso system, and the perimeter of the triangle formed by the transponders was used to calculate prostate volumes at sequential time points throughout the course of radiation therapy to a dose of 81 Gy in 1.8-Gy fractions. Results: There was a significant decrease in mean prostate volume of 10.9% from the first to the final day of radiation therapy. The volume loss did not occur monotonically but increased in most patients (75%) during the first several weeks to a median maximum on Day 7. The volume increased by a mean of 6.1% before decreasing by a mean maximum difference of 18.4% to nadir (p < 0.001 for both increase and decrease). Glandular shrinkage was asymmetric, with the apex to right base dimension varying more than twice that of the lateral dimension. For all dimensions, the mean change was <0.5 cm. Conclusion: Real-time transponder positions indicated a volume increase during the initial days of radiation therapy and then significant and asymmetric shrinkage by the final day. Understanding and tracking volume fluctuations of the prostate during radiation therapy can help real-time imaging technology perform to its fullest potential.

  2. NELL-1 increases pre-osteoblast mineralization using both phosphate transporter Pit1 and Pit2

    Energy Technology Data Exchange (ETDEWEB)

    Cowan, Catherine M. [Department of Bioengineering, University of California, Los Angeles, 420 Westwood Plaza,7523 Boelter Hall, Los Angeles, CA 90095 (United States); Dental and Craniofacial Research Institute and Section of Orthodontics, School of Dentistry, University of California, Los Angeles, 40833 Le Conte Ave, Los Angeles, CA 90095 (United States); Zhang, Xinli; James, Aaron W.; Mari Kim, T.; Sun, Nichole [Dental and Craniofacial Research Institute and Section of Orthodontics, School of Dentistry, University of California, Los Angeles, 40833 Le Conte Ave, Los Angeles, CA 90095 (United States); Wu, Benjamin [Department of Bioengineering, University of California, Los Angeles, 420 Westwood Plaza,7523 Boelter Hall, Los Angeles, CA 90095 (United States); Dental and Craniofacial Research Institute and Section of Orthodontics, School of Dentistry, University of California, Los Angeles, 40833 Le Conte Ave, Los Angeles, CA 90095 (United States); Ting, Kang [Dental and Craniofacial Research Institute and Section of Orthodontics, School of Dentistry, University of California, Los Angeles, 40833 Le Conte Ave, Los Angeles, CA 90095 (United States); Soo, Chia, E-mail: bsoo@ucla.edu [UCLA and Orthopaedic Hospital Department of Orthopaedic Surgery and the Orthopaedic, Hospital Research Center, University of California, Los Angeles, 2641 Charles E. Young Dr. South, Los Angeles, CA 90095 (United States)

    2012-06-08

    Highlights: Black-Right-Pointing-Pointer NELL-1 accelerates extracellular matrix mineralization in MC3T3-E1 pre-osteoblasts. Black-Right-Pointing-Pointer NELL-1 significantly increases intracellular inorganic phosphate levels. Black-Right-Pointing-Pointer NELL-1 positively regulates osteogenesis but not proliferation in MC3T3-E1 cells. Black-Right-Pointing-Pointer NELL-1 regulates inorganic phosphate transporter activity. -- Abstract: NELL-1 is a potent osteoinductive molecule that enhances bone formation in multiple animal models through currently unidentified pathways. In the present manuscript, we hypothesized that NELL-1 may regulate osteogenic differentiation accompanied by alteration of inorganic phosphate (Pi) entry into the osteoblast via sodium dependent phosphate (NaPi) transporters. To determine this, MC3T3-E1 pre-osteoblasts were cultured in the presence of recombinant human (rh)NELL-1 or rhBMP-2. Analysis was performed for intracellular Pi levels through malachite green staining, Pit-1 and Pit-2 expression, and forced upregulation of Pit-1 and Pit-2. Results showed rhNELL-1 to increase MC3T3-E1 matrix mineralization and Pi influx associated with activation of both Pit-1 and Pit-2 channels, with significantly increased Pit-2 production. In contrast, Pi transport elicited by rhBMP-2 showed to be associated with increased Pit-1 production only. Next, neutralizing antibodies against Pit-1 and Pit-2 completely abrogated the Pi influx effect of rhNELL-1, suggesting rhNELL-1 is dependent on both transporters. These results identify one potential mechanism of action for rhNELL-1 induced osteogenesis and highlight a fundamental difference between NELL-1 and BMP-2 signaling.

  3. NELL-1 increases pre-osteoblast mineralization using both phosphate transporter Pit1 and Pit2

    International Nuclear Information System (INIS)

    Cowan, Catherine M.; Zhang, Xinli; James, Aaron W.; Mari Kim, T.; Sun, Nichole; Wu, Benjamin; Ting, Kang; Soo, Chia

    2012-01-01

    Highlights: ► NELL-1 accelerates extracellular matrix mineralization in MC3T3-E1 pre-osteoblasts. ► NELL-1 significantly increases intracellular inorganic phosphate levels. ► NELL-1 positively regulates osteogenesis but not proliferation in MC3T3-E1 cells. ► NELL-1 regulates inorganic phosphate transporter activity. -- Abstract: NELL-1 is a potent osteoinductive molecule that enhances bone formation in multiple animal models through currently unidentified pathways. In the present manuscript, we hypothesized that NELL-1 may regulate osteogenic differentiation accompanied by alteration of inorganic phosphate (Pi) entry into the osteoblast via sodium dependent phosphate (NaPi) transporters. To determine this, MC3T3-E1 pre-osteoblasts were cultured in the presence of recombinant human (rh)NELL-1 or rhBMP-2. Analysis was performed for intracellular Pi levels through malachite green staining, Pit-1 and Pit-2 expression, and forced upregulation of Pit-1 and Pit-2. Results showed rhNELL-1 to increase MC3T3-E1 matrix mineralization and Pi influx associated with activation of both Pit-1 and Pit-2 channels, with significantly increased Pit-2 production. In contrast, Pi transport elicited by rhBMP-2 showed to be associated with increased Pit-1 production only. Next, neutralizing antibodies against Pit-1 and Pit-2 completely abrogated the Pi influx effect of rhNELL-1, suggesting rhNELL-1 is dependent on both transporters. These results identify one potential mechanism of action for rhNELL-1 induced osteogenesis and highlight a fundamental difference between NELL-1 and BMP-2 signaling.

  4. A Gold Nanoparticle Bio-Optical Transponder to Dynamically Monitor Intracellular pH.

    Science.gov (United States)

    Carnevale, Kate J F; Riskowski, Ryan A; Strouse, Geoffrey F

    2018-06-13

    A pH-sensitive bio-optical transponder (pH-BOT) capable of simultaneously reporting the timing of intracellular DNA cargo release from a gold nanoparticle (AuNP) and the evolving intracellular pH (pH i) during endosomal maturation is demonstrated. The pH-BOT is designed with a triple-dye-labeled duplex DNA appended to a 6.6 nm AuNP, utilizing pH-responsive fluorescein paired with DyLight405 as a surface energy transfer (SET) coupled dye pair to ratiometrically report the pH at and after cargo release. A non-SET-coupled dye, DyLight 700, is used to provide dynamic tracking throughout the experiment. The pH-BOT beacon of the cargo uptake, release, and processing was visualized using live-cell confocal fluorescent microscopy in Chinese hamster ovary cells, and it was observed that while maturation of endosomes carrying pH-BOT is slowed significantly, the pH-BOT is distributed throughout the endolysosomal system while remaining at pH ∼6. This observed decoupling of endosomal maturation from acidification lends support to those models that propose that pH alone is not sufficient to explain endosomal maturation and may enable greater insight into our understanding of the fundamental processes of biology.

  5. Spontaneous Resolution of Optic Disc Pit Maculopathy

    Directory of Open Access Journals (Sweden)

    Koushik Tripathy

    2017-06-01

    Full Text Available I read with interest the article reporting spontaneous resolution of optic disc pit maculopathy in a boy.1 Though the presence of an optic disc pit and associated macular involvement is undoubted in the presented case, the provided optical coherence tomography (OCT does not clearly show typical intraretinal schisis (Figure 1B1 at multiple retinal levels which may communicate with the pit. Instead, it shows a sub-internal limiting membrane (sub-ILM cavity. Such cavities are known to occur following the resolution of sub-ILM bleed due to various cause including Valsalva retinopathy,2 Terson syndrome, and also in some retinitis3 cases.4 In fact, some of these cavities may simulate a neurosensory retinal detachment or central serous chorioretinopathy on cursory clinical examination.5 To confirm that the features of the current patient1 are indeed related to the optic disc pit, it is necessary for the authors to provide an OCT scan which shows a connection of the presented cavity with the optic disc pit. Also, clear OCT scans of the fovea, both at presentation and at final follow-up would help our understanding of the visual recovery of the patient. The interval between the presenting (28 June 2012 OCT and final OCT (30 Nov 2012 is 5 months and not 6 months as described in the manuscript. For an effective comparison, both the presenting and final OCT scans should have been taken using either horizontal or vertical orientation over the macula. Though the spontaneous resolution of optic disc pit maculopathy is possible, visual recovery in usually unlikely and in such cases an alternate diagnosis needs to be excluded.

  6. Pitting corrosion of zirconium in aqueous solution

    International Nuclear Information System (INIS)

    El Shayeb, H.A.; Abd El Wahab, F.M.; Abd Elk Meguid, E.A.

    1994-01-01

    The open circuit potentials of the Zr electrode are followed as a function of time in various aqueous solutions till attainment of steady state values.The results are discussed on the basis of oxide film thickening and repair. Pitting corrosion of Zr was examined in chloride solutions using the potentiodynamic technique. The effect of some inorganic and organic additives was also investigated for inhibiting the pitting corrosion of Zr and the relative performance is presented and discussed. (author). 21 refs., 6 figs., 1 tab

  7. 5G in Open-Pit Mines

    DEFF Research Database (Denmark)

    Portela Lopes de Almeida, Erika; Caldwell, George; Rodriguez Larrad, Ignacio

    2017-01-01

    5G will play a pivotal role in the digitization of the industrial sector and is expected to make the best use of every bit of spectrum available. In this light, this paper presents the results of an extensive measurement campaign in two iron-ore open-pit mining complexes, at the 700 MHz and 2.6 GHz...... for the future wireless network design, simulation and performance evaluation. The results show that, in order to comply with ultra-reliable communications (URC) availability requirements, larger shadowing margins will have to be considered in the network planning in open-pit mines, when compared to traditional...

  8. ARIES pit disassembly-safeguards issues for transparency

    International Nuclear Information System (INIS)

    Fearey, B.L.; Cremers, T.L.

    1995-01-01

    Historic changes are now occurring in U.S. nonproliferation and arms control policy. The quantity of nuclear weapons required to provide a deterrence has decreased (especially with the end of the Cold War). Further, various bilateral and multilateral treaties now require the removal of numerous nuclear weapons from the U.S. stockpile. Although the removal of such weapons appears straightforward, the final disposition of the surplus weapons-grade nuclear material must be carefully considered. Domestically, several plutonium disposition plans are now under consideration concerning long-term safety, materials accounting, environmental impact, accessibility, and long-term containment. The Automated Retirement and Integrated Extraction System (ARIES) currently under development at Los Alamos National Laboratory is one such disposition method for the disassembly of plutonium weapons components (pits). The ARIES system integrates and automates several features: disassembly of pits, consolidation of the plutonium material, on-line measurement of final products, waste streams, and long-term packaging. Clearly, in any plutonium disposition plan, the safeguards aspects of materials control and accounting and the security aspects must be carefully considered and evaluated

  9. Modeling and management of pit lake water chemistry 1: Theory

    International Nuclear Information System (INIS)

    Castendyk, D.N.; Eary, L.E.; Balistrieri, L.S.

    2015-01-01

    Highlights: • Review of pit lake literature in the context of pit lake predictions. • Review of approaches used to predict pit wall-rock runoff and leachate. • Review of approaches used to generate a pit lake water balance. • Review of approaches used to generate a hydrodynamic prediction. • Review of approaches used to generate a geochemical prediction of a future pit lake. - Abstract: Pit lakes are permanent hydrologic/landscape features that can result from open pit mining for metals, coal, uranium, diamonds, oil sands, and aggregates. Risks associated with pit lakes include local and regional impacts to water quality and related impacts to aquatic and terrestrial ecosystems. Stakeholders rely on predictive models of water chemistry to prepare for and manage these risks. This paper is the first of a two part series on the modeling and management of pit lakes. Herein, we review approaches that have been used to quantify wall-rock runoff geochemistry, wall-rock leachate geochemistry, pit lake water balance, pit lake limnology (i.e. extent of vertical mixing), and pit lake water quality, and conclude with guidance on the application of models within the mine life cycle. The purpose of this paper is to better prepare stakeholders, including future modelers, mine managers, consultants, permitting agencies, land management agencies, regulators, research scientists, academics, and other interested parties, for the challenges of predicting and managing future pit lakes in un-mined areas

  10. Markov Chain Models for the Stochastic Modeling of Pitting Corrosion

    Directory of Open Access Journals (Sweden)

    A. Valor

    2013-01-01

    Full Text Available The stochastic nature of pitting corrosion of metallic structures has been widely recognized. It is assumed that this kind of deterioration retains no memory of the past, so only the current state of the damage influences its future development. This characteristic allows pitting corrosion to be categorized as a Markov process. In this paper, two different models of pitting corrosion, developed using Markov chains, are presented. Firstly, a continuous-time, nonhomogeneous linear growth (pure birth Markov process is used to model external pitting corrosion in underground pipelines. A closed-form solution of the system of Kolmogorov's forward equations is used to describe the transition probability function in a discrete pit depth space. The transition probability function is identified by correlating the stochastic pit depth mean with the empirical deterministic mean. In the second model, the distribution of maximum pit depths in a pitting experiment is successfully modeled after the combination of two stochastic processes: pit initiation and pit growth. Pit generation is modeled as a nonhomogeneous Poisson process, in which induction time is simulated as the realization of a Weibull process. Pit growth is simulated using a nonhomogeneous Markov process. An analytical solution of Kolmogorov's system of equations is also found for the transition probabilities from the first Markov state. Extreme value statistics is employed to find the distribution of maximum pit depths.

  11. Parturition pit: the bony imprint of vaginal birth

    International Nuclear Information System (INIS)

    McArthur, Tatum A.; Meyer, Isuzu; Jackson, Bradford; Pitt, Michael J.; Larrison, Matthew C.

    2016-01-01

    To retrospectively evaluate for pits along the dorsum of the pubic body in females and compare the presence/absence of these pits to vaginal birth data. We retrospectively reviewed females with vaginal birth data who underwent pelvic CT. The presence of pits along the dorsum of the pubic body, pit grade (0 = not present; 1 = faintly imperceptible; 2 = present; 3 = prominent), and the presence of osteitis condensans ilii, preauricular sulcus, and sacroiliac joint vacuum phenomenon were assessed on imaging. Musculoskeletal radiologists who were blinded to the birth data evaluated the CTs. 48 males were also evaluated for the presence of pits. 482 female patients underwent CT pelvis and 171 were excluded due to lack of vaginal birth data. Of the 311 study patients, 262 had prior vaginal birth(s) and 194 had pits on CT. Only 7 of the 49 patients without prior vaginal birth had pits. There was a statistically significant association between vaginal birth and presence of pits (p < 0.0001). Patients with more prominent pits (grades 2/3) had a greater number of vaginal births. As vaginal deliveries increased, the odds of having parturition pits greatly increased, adjusting for age and race at CT (p < 0.0001). No males had pits. Our study indicates that parturition pits are associated with prior vaginal birth and should be considered a characteristic of the female pelvis. The lytic appearance of prominent pits on imaging can simulate disease and create a diagnostic dilemma for interpreting radiologists. (orig.)

  12. The PIT-trap-A "model-free" bootstrap procedure for inference about regression models with discrete, multivariate responses.

    Science.gov (United States)

    Warton, David I; Thibaut, Loïc; Wang, Yi Alice

    2017-01-01

    Bootstrap methods are widely used in statistics, and bootstrapping of residuals can be especially useful in the regression context. However, difficulties are encountered extending residual resampling to regression settings where residuals are not identically distributed (thus not amenable to bootstrapping)-common examples including logistic or Poisson regression and generalizations to handle clustered or multivariate data, such as generalised estimating equations. We propose a bootstrap method based on probability integral transform (PIT-) residuals, which we call the PIT-trap, which assumes data come from some marginal distribution F of known parametric form. This method can be understood as a type of "model-free bootstrap", adapted to the problem of discrete and highly multivariate data. PIT-residuals have the key property that they are (asymptotically) pivotal. The PIT-trap thus inherits the key property, not afforded by any other residual resampling approach, that the marginal distribution of data can be preserved under PIT-trapping. This in turn enables the derivation of some standard bootstrap properties, including second-order correctness of pivotal PIT-trap test statistics. In multivariate data, bootstrapping rows of PIT-residuals affords the property that it preserves correlation in data without the need for it to be modelled, a key point of difference as compared to a parametric bootstrap. The proposed method is illustrated on an example involving multivariate abundance data in ecology, and demonstrated via simulation to have improved properties as compared to competing resampling methods.

  13. Some questions on small uranium open-pit mines

    International Nuclear Information System (INIS)

    Li Junyi

    1992-01-01

    The experiences of the existing uranium open pits are summarized and the questions in design, erection and production are analyzed. It is important helpful to develop and to design such economical and reasonable small uranium open pits

  14. Application of Surpac and Whittle Software in Open Pit Optimisation ...

    African Journals Online (AJOL)

    Application of Surpac and Whittle Software in Open Pit Optimisation and Design. ... This paper studies the Surpac and Whittle software and their application in designing an optimised pit. ... EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  15. The Application of Foundation Pit Monitoring Technology to the Excavation

    Directory of Open Access Journals (Sweden)

    Qiu Jin

    2015-01-01

    Full Text Available The foundation pit monitoring plays an important role in the foundation pit supporting projects especially in those deep foundation pit projects. Through the whole monitoring of the foundation pit construction from the excavation to the backfill, we can learn about the forcing and deforming process of the foundation pit supporting system, and grasp the impact of external condition changes on the foundation pit. This paper takes a project in Jinan as an example to establish a specific monitoring program, and then conducts the analysis and evaluation of the monitoring data; the real-time grasp of the foundation pit deformation and internal force changes can help to further ensure the security status of the foundation pit, thus better guiding the construction.

  16. Pit slope manual chapter 3. Mechanical properties

    Energy Technology Data Exchange (ETDEWEB)

    Gyenge, M.; Herget, G.

    1977-01-01

    Guidance is given on the procedures required to obtain adequate knowledge of the mechanical properties of the soils and rocks which constitute the walls of the pit. The reason why certain data is necessary is explained and the tests required to obtain these data are described.

  17. The cuisine of the Pitted Ware Culture

    DEFF Research Database (Denmark)

    Philippsen, Bente; Persson, Per

    The Pitted Ware Culture is a Middle Neolithic culture in southwestern Scandinavia. It appears about thousand years after the introduction of agriculture to this area. In some regions, it is characterized by an almost fully “Mesolithic” economy with a heavy reliance on seal hunting. In Djursland, ...

  18. Extracting Valuable Data from Classroom Trading Pits

    Science.gov (United States)

    Bergstrom, Theodore C.; Kwok, Eugene

    2005-01-01

    How well does competitive theory explain the outcome in experimental markets? The authors examined the results of a large number of classroom trading experiments that used a pit-trading design found in Experiments with Economic Principles, an introductory economics textbook by Bergstrom and Miller. They compared experimental outcomes with…

  19. COPPER PITTING CORROSION: A CASE STUDY

    Science.gov (United States)

    Localized or pitting corrosion of copper pipes used in household drinking-water plumbing is a problem for many water utilities and their customers. Extreme attack can lead to pinhole water leaks that may result in water damage, mold growth, and costly repairs. Water quality has b...

  20. Modelling the filling rate of pit latrines

    African Journals Online (AJOL)

    2012-09-18

    Sep 18, 2012 ... the transfer of water into and out of the pit, biological trans- formations, and pathogen die-off (Buckley et al., 2008). .... formations that consumed or generated it. However, the age distribution of the originally deposited unbiodegradable mate- rial depends only on the deposition history, as it undergoes no.

  1. Increased dose near the skin due to electromagnetic surface beacon transponder.

    Science.gov (United States)

    Ahn, Kang-Hyun; Manger, Ryan; Halpern, Howard J; Aydogan, Bulent

    2015-05-08

    The purpose of this study was to evaluate the increased dose near the skin from an electromagnetic surface beacon transponder, which is used for localization and tracking organ motion. The bolus effect due to the copper coil surface beacon was evaluated with radiographic film measurements and Monte Carlo simulations. Various beam incidence angles were evaluated for both 6 MV and 18 MV experimentally. We performed simulations using a general-purpose Monte Carlo code MCNPX (Monte Carlo N-Particle) to supplement the experimental data. We modeled the surface beacon geometry using the actual mass of the glass vial and copper coil placed in its L-shaped polyethylene terephthalate tubing casing. Film dosimetry measured factors of 2.2 and 3.0 enhancement in the surface dose for normally incident 6 MV and 18 MV beams, respectively. Although surface dose further increased with incidence angle, the relative contribution from the bolus effect was reduced at the oblique incidence. The enhancement factors were 1.5 and 1.8 for 6 MV and 18 MV, respectively, at an incidence angle of 60°. Monte Carlo simulation confirmed the experimental results and indicated that the epidermal skin dose can reach approximately 50% of the dose at dmax at normal incidence. The overall effect could be acceptable considering the skin dose enhancement is confined to a small area (~ 1 cm2), and can be further reduced by using an opposite beam technique. Further clinical studies are justified in order to study the dosimetric benefit versus possible cosmetic effects of the surface beacon. One such clinical situation would be intact breast radiation therapy, especially large-breasted women.

  2. Pit Viper strikes at the Hanford site. Pit maintenance using robotics at the Hanford Tank Farms

    International Nuclear Information System (INIS)

    Roeder-Smith, Lynne

    2002-01-01

    The Pit Viper--a remote operations waste retrieval system--was developed to replace manual operations in the valve pits of waste storage tanks at the Hanford Site. The system consists of a typical industrial backhoe fitted with a robotic manipulator arm and is operated remotely from a control trailer located outside of the tank farm. Cameras mounted to the arm and within the containment tent allow the operator to view the entire pit area and operate the system using a joystick. The arm's gripper can grasp a variety of tools that allow personnel to perform cleaning, debris removal, and concrete repair tasks--a more efficient and less dose-intensive process than the previous 'long-pole' method. The project team overcame a variety of obstacles during development and testing of the Pit Viper system, and deployment occurred in Hanford Tank C-104 in December 2001

  3. Pit Study, Geographic NAD83, LOSCO (1999) [pit_study_LOSCO_1998

    Data.gov (United States)

    Louisiana Geographic Information Center — The 'Pit Study' was meant to identify the remnants of former oil extraction sites which pose the threat of creating an oil spill. These remnants include many other...

  4. Open Pit Water Control Safety A Case Of Nchanga Open Pit Mine Zambia

    Directory of Open Access Journals (Sweden)

    Silwamba C

    2015-08-01

    Full Text Available Abstract Mining in Chingola Zambia started underground in 1931 and was catastrophically flooded and closed. The present Nchanga Underground Mine NUG started in 1937. The Nchanga Open Pit NOP mine started in 1955 situated to the west of NUG and partially overlying it. Open pit water control safety operations in the Nchanga-Chingola area have successfully enabled the safe extraction of millions of tonnes of copper ore annually over the past 60 years from NUG mining as well as the NOP. At the start Nchanga mining license surface already had NUG and many watershed divides with the Nchanga and Chingola streams being the main streams feeding into Zambias second largest river Kafue river and 42 of the year was characterised by heavy rains ranging between 800mm to 1300mm per annum. In this paper the presence of very significant amounts of seasonal rain and subsurface water in the mining area was identified as both a curse and a blessing. An excess in seasonal rain and subsurface water would disrupt both open pit and underground mining operations. In order for NOP to be operated successfully stable and free from flooding coping water management tactics were adopted from 1955 to 2015 including 1. Underground mine pump chamber pumping system 2. Piezometer instrumented boreholes 3. Underground mine 1500-ft sub-haulage east borehole dewatering beneath the open pit 4. Nchanga and Chingola stream diversionary tunnel and open drains 5. Nchanga stream causeway and embankment dam in the Matero School Golf Club area 6. Pit perimeter borehole pumping 7. Outer and inner pit perimeter drains and bund walls 8. In-pit ramp side drains 9. In-pit sub-horizontal borehole geo-drains and water and 10. Pit bottom sump pumps. Application of grout curtains along the Vistula River Poland was noted as a possibility in the right circumstances although it had never been used at Nchanga Open Pit. An additional conclusion was that forward health safety and environmental end

  5. Laboratory protocols for testing the efficacy of commercial pit latrine ...

    African Journals Online (AJOL)

    There is considerable national interest in the use of commercial microbially derived products for controlling the rate of accumulation of the contents of pit latrines. Manufacturers claim that some of these products can reduce accumulation rates, prevent the pit from ever filling up, or even result in decreases in pit contents ...

  6. Modeling sludge accumulation rates in lined pit latrines in slum ...

    African Journals Online (AJOL)

    Yvonne

    should include geo-physical characterization of soil and drainage of pit latrine sites so as ... Key words: Faecal, sludge accumulation rates, slum areas, lined pit latrines. .... Value and its unit Source .... overall quality of the models had to be assessed by validation on ..... Sanitation partnership series: Bringing pit emptying out.

  7. Congenital pits of the optic nerve head and retinochoroidal colobomas.

    Science.gov (United States)

    Brown, G C; Augsburger, J J

    1980-07-01

    A 45-year-old man presented with bilateral retinochoroidal colobomas associated with an inferonasal congenital pit of the optic nerve head in each eye. Different theories on the origin of such pits are discussed. This case supports the theory that some congenital optic pits occur as a result of failure of closure of the superior end of the embryonic fissure.

  8. Interacting Effects Induced by Two Neighboring Pits Considering Relative Position Parameters and Pit Depth

    Directory of Open Access Journals (Sweden)

    Yongfang Huang

    2017-04-01

    Full Text Available For pre-corroded aluminum alloy 7075-T6, the interacting effects of two neighboring pits on the stress concentration are comprehensively analyzed by considering various relative position parameters (inclination angle θ and dimensionless spacing parameter λ and pit depth (d with the finite element method. According to the severity of the stress concentration, the critical corrosion regions, bearing high susceptibility to fatigue damage, are determined for intersecting and adjacent pits, respectively. A straightforward approach is accordingly proposed to conservatively estimate the combined stress concentration factor induced by two neighboring pits, and a concrete application example is presented. It is found that for intersecting pits, the normalized stress concentration factor Ktnor increases with the increase of θ and λ and always reaches its maximum at θ = 90°, yet for adjacent pits, Ktnor decreases with the increase of λ and the maximum value appears at a slight asymmetric location. The simulations reveal that Ktnor follows a linear and an exponential relationship with the dimensionless depth parameter Rd for intersecting and adjacent cases, respectively.

  9. Analysis of BY-106 pump pit cover plate

    International Nuclear Information System (INIS)

    Coverdell, B.L.

    1994-01-01

    A new cover for the pump pit of Tank 241-BY-106 has been designed to allow the rotary core exhauster to be hooked up without requiring pit entry, riser modification, or equipment removal. The new pit cover is necessary to allow installation of two risers for reducing exposure, contamination, and waste. Computer analysis indicates that the safety margin of the pit cover plate with two risers is adequate. The computer stress model and input files are attached. The pit cover plate is a replacement for an existing plate; therefore seismic and wind loads were considered for the plate only

  10. Geochemical evolution of a high arsenic, alkaline pit-lake in the Mother Lode Gold District, California

    Science.gov (United States)

    Savage, Kaye S.; Ashley, Roger P.; Bird, Dennis K.

    2009-01-01

    The Harvard orebody at the Jamestown gold mine, located along the Melones fault zone in the southern Mother Lode gold district, California, was mined in an open-pit operation from 1987 to 1994. Dewatering during mining produced a hydrologic cone of depression; recovery toward the premining ground-water configuration produced a monomictic pit lake with alkaline Ca-Mg-HCO3-SO4–type pit water, concentrations of As up to 1,200 μg/L, and total dissolved solids (TDS) up to 2,000 mg/L. In this study, pit-wall rocks were mapped and chemically analyzed to provide a context for evaluating observed variability in the composition of the pit-lake waters in relationship to seasonal weather patterns. An integrated hydrogeochemical model of pit-lake evolution based on observations of pit-lake volume, water composition (samples collected between 1998–2000, 2004), and processes occurring on pit walls was developed in three stages using the computer code PHREEQC. Stage 1 takes account of seasonally variable water fluxes from precipitation, evaporation, springs, and ground water, as well as lake stratification and mixing processes. Stage 2 adds CO2fluxes and wall-rock interactions, and stage 3 assesses the predictive capability of the model.Two major geologic units in fault contact comprise the pit walls. The hanging wall is composed of interlayered slate, metavolcanic and metavolcaniclastic rocks, and schists; the footwall rocks are chlorite-actinolite and talc-tremolite schists generated by metasomatism of greenschist-facies mafic and ultramafic igneous rocks. Alteration in the ore zone provides evidence for mineralizing fluids that introduced CO2, S, and K2O, and redistributed SiO2. Arsenian pyrite associated with the alteration weathers to produce goethite and jarosite on pit walls and in joints, as well as copiapite and hexahydrite efflorescences that accumulate on wall-rock faces during dry California summers. All of these pyrite weathering products incorporate arsenic at

  11. COGEMA experience on retrieving and conditioning solid radwaste previously stored in pits. The La Hague North-West pit case

    International Nuclear Information System (INIS)

    Bodin, F.; Alexandre, D.; Fournier, P.

    1999-01-01

    Short lived, low and medium level waste called 'technological waste' produced by the La Hague Reprocessing Plant have been stored in the La Hague North-West concrete-lined pits until implementation at ANDRA's Centre de Stockage de la Manche (CSM). COGEMA decided to retrieve and condition 11,000 m 3 of humid solid radwaste, stored in bulk in pits. On account of the variety of radwaste kinds, retrieving and conditioning operations represented real challenge. One goal of these operations was to ensure that the work was performed in complete safety towards environment with optimum containment and with the best radiation protection for the personnel involved. COGEMA decided to split the work into two phases. The feedback from the first phase was very helpful to the second phase. This report describes the experience gained from February 1990 to December 1998, taking into account radwaste and integrated dose rate results conditioning such waste. The procedures and means used and improved by COGEMA to comply with ANDRA's storage standards and the ever-decreasing financial costs generated by the workers, allowed to retrieve and condition 11,000 m 3 of old solid radwaste with competitive costs and in complete safety and protection of the environment. (author)

  12. Optic disc pit with sectorial retinitis pigmentosa.

    Science.gov (United States)

    Balikoglu-Yilmaz, Melike; Taskapili, Muhittin; Yilmaz, Tolga; Teke, Mehmet Yasin

    2013-01-01

    Sectorial retinitis pigmentosa (RP) and optic disc pit (ODP) are rare clinical conditions. We present a 40-year-old woman with a history of mild night blindness and decreased vision in the right eye for about 5 years. Fundus examination revealed retinal pigmentary changes in the superior and inferotemporal sectors covering the macula and reduced arterial calibre and ODP at the temporal edge of the optic disc. In addition, fundus autofluorescence, spectral-domain optical coherence tomography, fluorescein angiography, and multifocal electroretinogram scans confirmed these clinical findings. Visual acuity was decreased due to an atrophic-appearing foveal lesion. No intervention was suggested because of the poor visual potential. To the best of our knowledge, the present study is the first to describe coexistent optic disc pit and sectorial RP in the superior and inferotemporal sectors covering the macula in the same eye with figures.

  13. Optic Disc Pit with Sectorial Retinitis Pigmentosa

    Directory of Open Access Journals (Sweden)

    Melike Balikoglu-Yilmaz

    2013-01-01

    Full Text Available Sectorial retinitis pigmentosa (RP and optic disc pit (ODP are rare clinical conditions. We present a 40-year-old woman with a history of mild night blindness and decreased vision in the right eye for about 5 years. Fundus examination revealed retinal pigmentary changes in the superior and inferotemporal sectors covering the macula and reduced arterial calibre and ODP at the temporal edge of the optic disc. In addition, fundus autofluorescence, spectral-domain optical coherence tomography, fluorescein angiography, and multifocal electroretinogram scans confirmed these clinical findings. Visual acuity was decreased due to an atrophic-appearing foveal lesion. No intervention was suggested because of the poor visual potential. To the best of our knowledge, the present study is the first to describe coexistent optic disc pit and sectorial RP in the superior and inferotemporal sectors covering the macula in the same eye with figures.

  14. Treatment of a mud pit by bioremediation.

    Science.gov (United States)

    Avdalović, Jelena; Đurić, Aleksandra; Miletić, Srdjan; Ilić, Mila; Milić, Jelena; Vrvić, Miroslav M

    2016-08-01

    The mud generated from oil and natural gas drilling, presents a considerable ecological problem. There are still insufficient remedies for the removal and minimization of these very stable emulsions. Existing technologies that are in use, more or less successfully, treat about 20% of generated waste drilling mud, while the rest is temporarily deposited in so-called mud pits. This study investigated in situ bioremediation of a mud pit. The bioremediation technology used in this case was based on the use of naturally occurring microorganisms, isolated from the contaminated site, which were capable of using the contaminating substances as nutrients. The bioremediation was stimulated through repeated inoculation with a zymogenous microbial consortium, along with mixing, watering and biostimulation. Application of these bioremediation techniques reduced the concentration of total petroleum hydrocarbons from 32.2 to 1.5 g kg(-1) (95% degradation) during six months of treatment. © The Author(s) 2016.

  15. Optic Disc Pit with Sectorial Retinitis Pigmentosa

    OpenAIRE

    Balikoglu-Yilmaz, Melike; Taskapili, Muhittin; Yilmaz, Tolga; Teke, Mehmet Yasin

    2013-01-01

    Sectorial retinitis pigmentosa (RP) and optic disc pit (ODP) are rare clinical conditions. We present a 40-year-old woman with a history of mild night blindness and decreased vision in the right eye for about 5 years. Fundus examination revealed retinal pigmentary changes in the superior and inferotemporal sectors covering the macula and reduced arterial calibre and ODP at the temporal edge of the optic disc. In addition, fundus autofluorescence, spectral-domain optical coherence tomography, ...

  16. Pitting corrosion resistant austenite stainless steel

    Science.gov (United States)

    van Rooyen, D.; Bandy, R.

    A pitting corrosion resistant austenite stainless steel comprises 17 to 28 wt. % chromium, 15 to 26 wt. % nickel, 5 to 8 wt. % molybdenum, and 0.3 to 0.5 wt. % nitrogen, the balance being iron, unavoidable impurities, minor additions made in the normal course of melting and casting alloys of this type, and may optionally include up to 10 wt. % of manganese, up to 5 wt. % of silicon, and up to 0.08 wt. % of carbon.

  17. Investigating pitting in X65 carbon steel using potentiostatic polarisation

    Science.gov (United States)

    Mohammed, Sikiru; Hua, Yong; Barker, R.; Neville, A.

    2017-11-01

    Although pitting corrosion in passive materials is generally well understood, the growth of surface pits in actively-corroding materials has received much less attention to date and remains poorly understood. One of the key challenges which exists is repeatedly and reliably generating surface pits in a practical time-frame in the absence of deformation and/or residual stress so that studies on pit propagation and healing can be performed. Another pertinent issue is how to evaluate pitting while addressing general corrosion in low carbon steel. In this work, potentiostatic polarisation was employed to induce corrosion pits (free from deformation or residual stress) on actively corroding X65 carbon steel. The influence of applied potential (50 mV, 100 mV and 150 mV vs open circuit potential) was investigated over 24 h in a CO2-saturated, 3.5 wt.% NaCl solution at 30 °C and pH 3.8. Scanning electron microscopy (SEM) was utilised to examine pits, while surface profilometry was conducted to measure pit depth as a function of applied potential over the range considered. Analyses of light pitting (up to 120 μm) revealed that pit depth increased linearly with increase in applied potential. This paper relates total pit volume (measured using white light interferometry) to dissipated charge or total mass loss (using the current response for potentiostatic polarisation in conjunction with Faraday's law). By controlling the potential of the surface (anodic) the extent of pitting and general corrosion could be controlled. This allowed pits to be evaluated for their ability to continue to propagate after the potentiostatic technique was employed. Linear growth from a depth of 70 μm at pH 3.8, 80 °C was demonstrated. The technique offers promise for the study of inhibition of pitting.

  18. An implantable, batteryless, and wireless capsule with integrated impedance and pH sensors for gastroesophageal reflux monitoring.

    Science.gov (United States)

    Cao, Hung; Landge, Vaibhav; Tata, Uday; Seo, Young-Sik; Rao, Smitha; Tang, Shou-Jiang; Tibbals, H F; Spechler, Stuart; Chiao, J-C

    2012-11-01

    In this study, a device for gastroesophageal reflux disease (GERD) monitoring has been prototyped. The system consists of an implantable, batteryless and wireless transponder with integrated impedance and pH sensors; and a wearable, external reader that wirelessly powers up the transponder and interprets the transponded radio-frequency signals. The transponder implant with the total size of 0.4 cm × 0.8 cm × 3.8 cm harvests radio frequency energy to operate dual-sensor and load-modulation circuitry. The external reader can store the data in a memory card and/or send it to a base station wirelessly, which is optional in the case of multiple-patient monitoring in a hospital or conducting large-scale freely behaving animal experiments. Tests were carried out to verify the signal transduction reliability in different situations for antenna locations and orientation. In vitro, experiments were conducted in a mannequin model by positioning the sensor capsule inside the wall of a tube mimicking the esophagus. Different liquids with known pH values were flushed through the tube creating reflux episodes and wireless signals were recorded. Live pigs under anesthesia were used for the animal models with the transponder implant attached on the esophageal wall. The reflux episodes were created while the sensor data were recorded wirelessly. The data were compared with those recorded independently by a clinically used wireless pH sensor capsule placed next to our implant transponder. The results showed that our transponder detected every episode in both acid and nonacid nature, while the commercial pH sensor missed events that had similar, repeated pH values, and failed to detect pH values higher than 10. Our batteryless transponder does not require a battery thus allowing longer diagnosis and prognosis periods to monitor drug efficacy, as well as providing accurate assessment of GERD symptoms.

  19. Influence of Pitting Corrosion on Fatigue and Corrosion Fatigue of Ship and Offshore Structures, Part II: Load - Pit - Crack Interaction

    Directory of Open Access Journals (Sweden)

    Jakubowski Marek

    2015-09-01

    Full Text Available In the paper has been discussed influence of stresses on general corrosion rate and corrosion pit nucleation rate and growth , whose presence has been questioned by some authors but accepted by most of them. Influence of roughness of pit walls on fatigue life of a plate suffering pit corrosion and presence of the so called „ non-damaging” pits which never lead to initiation of fatigue crack, has been presented. Possibility of prediction of pit-to-crack transition moment by two different ways, i.e. considering a pit a stress concentrator or an equivalent crack, has been analyzed. Also, influence of statistical distribution of depth of corrosion pits as well as anticorrosion protection on fatigue and corrosion fatigue has been described.

  20. Burn Pit Emissions Exposure and Respiratory and Cardiovascular Conditions Among Airborne Hazards and Open Burn Pit Registry Participants.

    Science.gov (United States)

    Liu, Jason; Lezama, Nicholas; Gasper, Joseph; Kawata, Jennifer; Morley, Sybil; Helmer, Drew; Ciminera, Paul

    2016-07-01

    The aim of this study was to determine how burn pit emissions exposure is associated with the incidence of respiratory and cardiovascular conditions. We examined the associations between assumed geographic and self-reported burn pit emissions exposure and respiratory and cardiovascular outcomes in participants of the Airborne Hazards and Open Burn Pit Registry. We found significant dose-response associations for higher risk of self-reported emphysema, chronic bronchitis, or chronic obstructive pulmonary disease with increased days of deployment within 2 miles of selected burn pits (P-trend = 0.01) and self-reported burn pit smoke exposure (P-trend = 0.0005). We found associations between burn pit emissions exposure and higher incidence of post-deployment self-reported respiratory and cardiovascular conditions, but these findings should be interpreted with caution because the surrogate measurements of burn pit emissions exposure in this analysis may not reflect individual exposure levels.

  1. Clinico epidemiological study of pitted keratolysis

    Directory of Open Access Journals (Sweden)

    Naik Chandra

    2007-01-01

    Full Text Available Background: Pitted keratolysis is a common dermatological condition. However, very few studies are available on the clinical characteristics and epidemiological features of this disorder from India and abroad. Materials and Methods: Fifty patients from rural area of Kolar at Sri R.L.J.H. and S.N.R. Hospital, presenting with clinically distinctive lesions of pitted keratolysis were included in the study. Cases were interviewed with particular emphasis on triggering factors and findings were recorded. Investigations like Gram′s stain, culture studies, Wood′s ultraviolet light examination, histopathology etc, was done in selected cases to ascertain the clinical diagnosis. Results: Age of the patients varied from 20 to 40 years in 52% with male preponderance in 82% of cases. Duration of the disease varied from 15 days to five years, most of the patients were bare-footed farmers (62% of cases. Hyperhidrosis and pruritus were most frequently observed symptoms in 70% and 60% of patients. Most of the patients presented with the characteristic pits which varied from 1 to 50 in number in 56 % of cases, located predominantly on the pressure bearing areas in 92% of cases and depth of the pits varied from 1 to 2 mm in 60% of cases. Associated skin conditions recorded in present study were fissuring of soles in 38%, psoriasis 10%, dermatophyte infections in 6%, planter warts 6% and Corynebacterial triad and corn in 2% of patients each. Discussion: Affection of bare-footed individuals, male preponderance, presence of hyperhidrosis and occurrence of lesions over pressure bearing areas of soles, observed in the present study were consistent with earlier studies on the subject. However, pruritus as commonest presenting symptom reported by 60% patients in the present study, has not been documented in the previous studies. Conclusion: Pitted keratolysis is fairly common in bare footed male farmers of rural India. The condition is predominantly seen over the

  2. Effect of an Antibacterial Monomer on the Antibacterial Activity of a Pit-and-Fissure Sealant.

    Directory of Open Access Journals (Sweden)

    Fan Yu

    Full Text Available Resin-based pit-and-fissure sealants are often used to form a barrier on the occlusal surface of molars to treat caries lesions; however, bacteria can remain in the pit and fissures without detection, increasing the risk of secondary caries. Sealants with antimicrobial properties or microbial repellent actions might be advantageous. The aim of this study was to assess the inhibitory effect of a 2-methacryloxylethyl dodecyl methyl ammonium bromide (MAE-DB-incorporated sealant against Streptococcus mutans. MAE-DB (4% wt was incorporated into a commercially available sealant, Eco-S resin-based pit-and-fissure sealant (Vericom Co., Ltd., Korea; a sealant without MAE-DB served as a negative control, and Clinpro™ Sealant (3M™ ESPE™, a fluoride-releasing resin, was used as a commercial control. The effects of the cured sealants and their eluents on the growth of S. mutans were determined according to colony-forming unit counts and metabolic tests. The effects of the cured sealants on the adherence and membrane integrity of S. mutans were investigated using confocal laser-scanning microscopy (CLSM in conjunction with fluorescent indicators. Compared with the negative control and commercial control, the cured MAE-DB-incorporated pit-and-fissure sealant exhibited a significant inhibitory effect on the growth of S. mutans (P < 0.05, whereas the eluents did not show any detectable antibacterial activity. The commercial control also showed no detectable bactericidal activity. Moreover, the aged experimental material retained its property of contact inhibition of biofilm formation. The fluorescence analysis of CLSM images demonstrated that the cured MAE-DB-incorporated sealant could hamper the adherence of S. mutans and exert a detrimental effect on bacterial membrane integrity. The incorporation of MAE-DB can render a pit-and-fissure sealant with contact antibacterial activity after polymerization via influencing the growth, adherence, and membrane

  3. Detecting pits in tart cherries by hyperspectral transmission imaging

    Science.gov (United States)

    Qin, Jianwei; Lu, Renfu

    2004-11-01

    The presence of pits in processed cherry products causes safety concerns for consumers and imposes potential liability for the food industry. The objective of this research was to investigate a hyperspectral transmission imaging technique for detecting the pit in tart cherries. A hyperspectral imaging system was used to acquire transmission images from individual cherry fruit for four orientations before and after pits were removed over the spectral region between 450 nm and 1,000 nm. Cherries of three size groups (small, intermediate, and large), each with two color classes (light red and dark red) were used for determining the effect of fruit orientation, size, and color on the pit detection accuracy. Additional cherries were studied for the effect of defect (i.e., bruises) on the pit detection. Computer algorithms were developed using the neural network (NN) method to classify the cherries with and without the pit. Two types of data inputs, i.e., single spectra and selected regions of interest (ROIs), were compared. The spectral region between 690 nm and 850 nm was most appropriate for cherry pit detection. The NN with inputs of ROIs achieved higher pit detection rates ranging from 90.6% to 100%, with the average correct rate of 98.4%. Fruit orientation and color had a small effect (less than 1%) on pit detection. Fruit size and defect affected pit detection and their effect could be minimized by training the NN with properly selected cherry samples.

  4. Open Pit Water Control Safety A Case Of Nchanga Open Pit Mine Zambia

    OpenAIRE

    Silwamba C; Chileshe P R K

    2015-01-01

    Abstract Mining in Chingola Zambia started underground in 1931 and was catastrophically flooded and closed. The present Nchanga Underground Mine NUG started in 1937. The Nchanga Open Pit NOP mine started in 1955 situated to the west of NUG and partially overlying it. Open pit water control safety operations in the Nchanga-Chingola area have successfully enabled the safe extraction of millions of tonnes of copper ore annually over the past 60 years from NUG mining as well as the NOP. At the st...

  5. Markov chain modelling of pitting corrosion in underground pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Caleyo, F. [Departamento de Ingenieri' a Metalurgica, ESIQIE, IPN, UPALM Edif. 7, Zacatenco, Mexico D. F. 07738 (Mexico)], E-mail: fcaleyo@gmail.com; Velazquez, J.C. [Departamento de Ingenieri' a Metalurgica, ESIQIE, IPN, UPALM Edif. 7, Zacatenco, Mexico D. F. 07738 (Mexico); Valor, A. [Facultad de Fisica, Universidad de La Habana, San Lazaro y L, Vedado, 10400 La Habana (Cuba); Hallen, J.M. [Departamento de Ingenieri' a Metalurgica, ESIQIE, IPN, UPALM Edif. 7, Zacatenco, Mexico D. F. 07738 (Mexico)

    2009-09-15

    A continuous-time, non-homogenous linear growth (pure birth) Markov process has been used to model external pitting corrosion in underground pipelines. The closed form solution of Kolmogorov's forward equations for this type of Markov process is used to describe the transition probability function in a discrete pit depth space. The identification of the transition probability function can be achieved by correlating the stochastic pit depth mean with the deterministic mean obtained experimentally. Monte-Carlo simulations previously reported have been used to predict the time evolution of the mean value of the pit depth distribution for different soil textural classes. The simulated distributions have been used to create an empirical Markov chain-based stochastic model for predicting the evolution of pitting corrosion depth and rate distributions from the observed properties of the soil. The proposed model has also been applied to pitting corrosion data from pipeline repeated in-line inspections and laboratory immersion experiments.

  6. Markov chain modelling of pitting corrosion in underground pipelines

    International Nuclear Information System (INIS)

    Caleyo, F.; Velazquez, J.C.; Valor, A.; Hallen, J.M.

    2009-01-01

    A continuous-time, non-homogenous linear growth (pure birth) Markov process has been used to model external pitting corrosion in underground pipelines. The closed form solution of Kolmogorov's forward equations for this type of Markov process is used to describe the transition probability function in a discrete pit depth space. The identification of the transition probability function can be achieved by correlating the stochastic pit depth mean with the deterministic mean obtained experimentally. Monte-Carlo simulations previously reported have been used to predict the time evolution of the mean value of the pit depth distribution for different soil textural classes. The simulated distributions have been used to create an empirical Markov chain-based stochastic model for predicting the evolution of pitting corrosion depth and rate distributions from the observed properties of the soil. The proposed model has also been applied to pitting corrosion data from pipeline repeated in-line inspections and laboratory immersion experiments.

  7. Assessment and remediation of earthen pits in Alberta

    International Nuclear Information System (INIS)

    Lye, D.E.; Deibert, L.

    1999-01-01

    The proper decommissioning of abandoned earthen pits and the elimination of the associated environmental liabilities were discussed. An earthen pit is an excavated pit used by upstream oil and gas companies to contain/store/burn produced fluids and gases from either gas or oil producing operations. Produced fluids may include liquid hydrocarbons, process chemicals and water originating from oil wells, gas wells, and associated batteries and processing facilities. Improper operation and management at some pits has resulted in soil and/or groundwater contamination. In response to regulatory direction, petroleum operators in Alberta have begun the process of replacing earthen pits with alternative flaring and liquid storage facilities, and embarked on programs to assess, remediate and decommission earthen pits at their operations. This paper describes some of the challenges facing petroleum operators in this regard. It also outlines the regulatory framework within which decommissioning projects must be completed. 2 tabs

  8. Bingham Pump Outage Pits: Environmental information document

    International Nuclear Information System (INIS)

    Pekkala, R.O.; Jewell, C.E.; Holmes, W.G.; Marine, I.W.

    1987-03-01

    Seven waste sites known as the Bingham Pump Outage Pits located in areas of the Savannah River Plant (SRP) received solid waste containing an estimated 4 Ci of low-level radioactivity in 1957-1958. These sites were subsequently backfilled and have been inactive since that time. Most of the radioactivity at the Bingham Pump Outage Pits has been eliminated by radioactive decay. A total of approximately 1 Ci of activity (primarily 137 Cs and 90 Sr) is estimated to remain at the seven sites. The closure options considered for the Bingham Pump Outage Pits are waste removal and closure, no waste removal and closure, and no action. The predominant pathways for human exposure to chemical and/or radioactive constituents are through surface, subsurface, and atmospheric transport. Modeling calculations were made to determine the risks to human population via these general pathways for the three postulated closure options. An ecological assessment was conducted to predict the environmental impacts on aquatic and terrestrial biota. The relative costs for each of the closure options were estimated. Evaluation indicates that the relative human health risks for all closure options are small. The greatest public risk would occur after the waste site was released to unrestricted public use (assumed to occur in Year 2085) via the groundwater pathway to a well. The cost estimates show that the waste removal and closure option is the most expensive (89.6 million dollars). The cost of the no waste removal and the no action options is $800,000. 35 refs., 26 figs., 47 tabs

  9. SU-F-J-27: Segmentation of Prostate CBCT Images with Implanted Calypso Transponders Using Double Haar Wavelet Transform

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Y [Shandong Communication and Media College, Jinan, Shandong (China); Saleh, Z; Tang, X [Memorial Sloan Kettering Cancer Center, West Harrison, NY (United States); Song, Y; Obcemea, C [Memorial Sloan-Kettering Cancer Center, Sleepy Hollow, NY (United States); Chan, M [Memorial Sloan-Kettering Cancer Center, Basking Ridge, NJ (United States); Li, X [Memorial Sloan Kettering Cancer Center, Rockville Centre, NY (United States); Happersett, L [Memorial Sloan Kettering Cancer Center, New York, NY (United States); Shi, C [Saint Vincent Medical Center, Bridgeport, CT (United States); Qian, X [North Shore Long Island Jewish health System, North New Hyde Park, NY (United States)

    2016-06-15

    Purpose: Segmentation of prostate CBCT images is an essential step towards real-time adaptive radiotherapy. It is challenging For Calypso patients, as more artifacts are generated by the beacon transponders. We herein propose a novel wavelet-based segmentation algorithm for rectum, bladder, and prostate of CBCT images with implanted Calypso transponders. Methods: Five hypofractionated prostate patients with daily CBCT were studied. Each patient had 3 Calypso transponder beacons implanted, and the patients were setup and treated with Calypso tracking system. Two sets of CBCT images from each patient were studied. The structures (i.e. rectum, bladder, and prostate) were contoured by a trained expert, and these served as ground truth. For a given CBCT, the moving window-based Double Haar transformation is applied first to obtain the wavelet coefficients. Based on a user defined point in the object of interest, a cluster algorithm based adaptive thresholding is applied to the low frequency components of the wavelet coefficients, and a Lee filter theory based adaptive thresholding is applied to the high frequency components. For the next step, the wavelet reconstruction is applied to the thresholded wavelet coefficients. A binary/segmented image of the object of interest is therefore obtained. DICE, sensitivity, inclusiveness and ΔV were used to evaluate the segmentation result. Results: Considering all patients, the bladder has the DICE, sensitivity, inclusiveness, and ΔV ranges of [0.81–0.95], [0.76–0.99], [0.83–0.94], [0.02–0.21]. For prostate, the ranges are [0.77–0.93], [0.84–0.97], [0.68–0.92], [0.1–0.46]. For rectum, the ranges are [0.72–0.93], [0.57–0.99], [0.73–0.98], [0.03–0.42]. Conclusion: The proposed algorithm appeared effective segmenting prostate CBCT images with the present of the Calypso artifacts. However, it is not robust in two scenarios: 1) rectum with significant amount of gas; 2) prostate with very low contrast. Model

  10. Millennium Open Pit Mine, Alberta, Canada

    Science.gov (United States)

    2007-01-01

    Near Fort McMurray, Alberta, Canada, on the east bank of the Athabasca River, are found the Steepbank and Millennium mines. These open pit mines produce oil sands that are processed to recover bitumen, and then upgrade it to refinery-ready raw crude oil, and diesel fuel. The ASTER images were acquired September 22, 2000 and July 31, 2007, cover an area of 22.5 x 25.5 km, and are located near 57 degrees north latitude, 111.5 degrees west longitude. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  11. The Pit and the Safety Pendulum

    Energy Technology Data Exchange (ETDEWEB)

    Nitschke, Robert Leon; Ramos, Amadeo Gabriel

    2000-11-01

    The hypothesis of this paper is that the safety analysis pendulum has swung considerably in the direction of increasingly complex and lengthy safety evaluations and intense reviews during the past 30 years. The test of this hypothesis will be a review of the safety analysis conducted for various activities associated with the retrieval of transuranic radioactive waste from burial pits at a National Laboratory site over a span of 30 years. The examination will focus on the safety aspects and the safety analysis that was conducted for the projects. At the conclusion of this examination, the paper will identify five reasons why the changes have taken place.

  12. Markov Chain Models for the Stochastic Modeling of Pitting Corrosion

    OpenAIRE

    Valor, A.; Caleyo, F.; Alfonso, L.; Velázquez, J. C.; Hallen, J. M.

    2013-01-01

    The stochastic nature of pitting corrosion of metallic structures has been widely recognized. It is assumed that this kind of deterioration retains no memory of the past, so only the current state of the damage influences its future development. This characteristic allows pitting corrosion to be categorized as a Markov process. In this paper, two different models of pitting corrosion, developed using Markov chains, are presented. Firstly, a continuous-time, nonhomogeneous linear growth (pure ...

  13. Research process of nondestructive testing pitting corrosion in metal material

    Directory of Open Access Journals (Sweden)

    Bo ZHANG

    2017-12-01

    Full Text Available Pitting corrosion directly affects the usability and service life of metal material, so the effective nondestructive testing and evaluation on pitting corrosion is of great significance for fatigue life prediction because of data supporting. The features of pitting corrosion are elaborated, and the relation between the pitting corrosion parameters and fatigue performance is pointed out. Through introducing the fundamental principles of pitting corrosion including mainly magnetic flux leakage inspection, pulsed eddy current and guided waves, the research status of nondestructive testing technology for pitting corrosion is summarized, and the key steps of nondestructive testing technologies are compared and analyzed from the theoretical model, signal processing to industrial applications. Based on the analysis of the signal processing specificity of different nondestructive testing technologies in detecting pitting corrosion, the visualization combined with image processing and signal analysis are indicated as the critical problems of accurate extraction of pitting defect information and quantitative characterization for pitting corrosion. The study on non-contact nondestructive testing technologies is important for improving the detection precision and its application in industries.

  14. Modeling pitting corrosion damage of high-level radioactive-waste containers, with emphasis on the stochastic approach

    Energy Technology Data Exchange (ETDEWEB)

    Henshall, G.A.; Halsey, W.G.; Clarke, W.L.; McCright, R.D.

    1993-01-01

    Recent efforts to identify methods of modeling pitting corrosion damage of high-level radioactive-waste containers are described. The need to develop models that can provide information useful to higher level system performance assessment models is emphasized, and examples of how this could be accomplished are described. Work to date has focused upon physically-based phenomenological stochastic models of pit initiation and growth. These models may provide a way to distill information from mechanistic theories in a way that provides the necessary information to the less detailed performance assessment models. Monte Carlo implementations of the stochastic theory have resulted in simulations that are, at least qualitatively, consistent with a wide variety of experimental data. The effects of environment on pitting corrosion have been included in the model using a set of simple phenomenological equations relating the parameters of the stochastic model to key environmental variables. The results suggest that stochastic models might be useful for extrapolating accelerated test data and for predicting the effects of changes in the environment on pit initiation and growth. Preliminary ideas for integrating pitting models with performance assessment models are discussed. These ideas include improving the concept of container ``failure``, and the use of ``rules-of-thumb`` to take information from the detailed process models and provide it to the higher level system and subsystem models. Finally, directions for future work are described, with emphasis on additional experimental work since it is an integral part of the modeling process.

  15. Modeling pitting corrosion damage of high-level radioactive-waste containers, with emphasis on the stochastic approach

    International Nuclear Information System (INIS)

    Henshall, G.A.; Halsey, W.G.; Clarke, W.L.; McCright, R.D.

    1993-01-01

    Recent efforts to identify methods of modeling pitting corrosion damage of high-level radioactive-waste containers are described. The need to develop models that can provide information useful to higher level system performance assessment models is emphasized, and examples of how this could be accomplished are described. Work to date has focused upon physically-based phenomenological stochastic models of pit initiation and growth. These models may provide a way to distill information from mechanistic theories in a way that provides the necessary information to the less detailed performance assessment models. Monte Carlo implementations of the stochastic theory have resulted in simulations that are, at least qualitatively, consistent with a wide variety of experimental data. The effects of environment on pitting corrosion have been included in the model using a set of simple phenomenological equations relating the parameters of the stochastic model to key environmental variables. The results suggest that stochastic models might be useful for extrapolating accelerated test data and for predicting the effects of changes in the environment on pit initiation and growth. Preliminary ideas for integrating pitting models with performance assessment models are discussed. These ideas include improving the concept of container ''failure'', and the use of ''rules-of-thumb'' to take information from the detailed process models and provide it to the higher level system and subsystem models. Finally, directions for future work are described, with emphasis on additional experimental work since it is an integral part of the modeling process

  16. Mudstone depressurization behaviour in an open pit coal mine, Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Marchand, G.; Waterhouse, J. [Golder Associates, West Perth, WA (Australia); Crisostomo, J. [PT Adaro Indonesia, Jakarta (Indonesia)

    2010-07-01

    Mining activities in the Tutupan mine in Indonesia began in the mid-1990s. The open pit mine's coal seams are interbedded with fine-grained sandstones, mudstones, and carbonaceous mudstones. Slope stability analyses at the pit have integrated hydrogeology with geotechnical engineering analyses to optimize slope designs and reduce the risk of slope failure. This paper discussed the impact of mining and dewatering on mudstone depressurization. Sensors were placed at key points in the mine to obtain data related to the mudstone units. Reductions in pore pressure occurred as a result of groundwater flow away from the observed zones, increases in porosity, and increases in total porosity caused by an expansion of the rock mass as a result of drainage and hydrostatic unloading. Mudstone pore pressure trends with time were interpreted by determining the thickness of the mudstone unit, the presence or absence of known thin sandstone beds, unloading from overhead mining activities, and the position of the mudstone within the sedimentary sequence. The study showed that unloading activities have a significant impact on pore pressure in thick mudstone units, regardless of the depth, thickness, or properties of the unit. Pore pressure within high wall mudstone units typically decreased to values equivalent to the elevation of the unit where it was exposed to dips in a high wall. The dewatering of sandstone units in low walls caused a decline in pore pressure within the thick mudstone units located beneath the sandstones. Differences in primary permeabilities were attributed to greater fracturing in deeper and stronger rock units. 3 refs., 4 figs.

  17. Radon and aerosol release from open-pit uranium mining

    International Nuclear Information System (INIS)

    Thomas, V.W.; Nielson, K.K.; Mauch, M.L.

    1982-08-01

    The quantity of 222 Rn (hereafter called radon) released per unit of uranium produced from open pit mining has been determined. A secondary objective was to determine the nature and quantity of airborne particles resulting from mine operations. To accomplish these objectives, a comprehensive study of the release rates of radon and aerosol material to the atmosphere was made over a one-year period from April 1979 to May 1980 at the Morton Ranch Mine which was operated by United Nuclear Corporation (UNC) in partnership with Tennessee Valley Authority (TVA). The mine is now operated for TVA by Silver King Mines. Morton Ranch Mine was one of five open pit uranium mines studied in central Wyoming. Corroborative measurements were made of radon flux and 226 Ra (hereafter called radium) concentrations of various surfaces at three of the other mines in October 1980 and again at these three mines plus a fourth in April of 1981. Three of these mines are located in the Powder River Basin, about 80 kilometers east by northeast of Casper. One is located in the Shirley Basin, about 60 km south of Casper, and the remaining one is located in the Gas Hills, approximately 100 km west of Casper. The one-year intensive study included simultaneous measurement of several parameters: continuous measurement of atmospheric radon concentration near the ground at three locations, monthly 24-hour radon flux measurements from various surfaces, radium analyses of soil samples collected under each of the flux monitoring devices, monthly integrations of aerosols on dichotomous aerosol samplers, analysis of aerosol samplers for total dust loading, aerosol elemental and radiochemical composition, aerosol elemental composition by particle size, wind speed, wind direction, temperature, barometric pressure, and rainfall

  18. Location Optimization for Biomass Trigeneration System with Pit Thermal Energy Storage: the Case of the City of Petrinja

    DEFF Research Database (Denmark)

    Ćosić, B.; Dominkovic, Dominik Franjo; Ban, M.

    2015-01-01

    The combined production of electricity, heat and cold in biomass trigeneration power plants integrated with seasonal pit thermal energy storage ensures maximum utilization of biomass resources and at the same time reduction of variable operation costs of the system. Beside optimal size of trigene...

  19. Numerical modelling of the groundwater inflow to an advancing open pit mine: Kolahdarvazeh pit, Central Iran.

    Science.gov (United States)

    Bahrami, Saeed; Doulati Ardejani, Faramarz; Aslani, Soheyla; Baafi, Ernest

    2014-12-01

    The groundwater inflow into a mine during its life and after ceasing operations is one of the most important concerns of the mining industry. This paper presents a hydrogeological assessment of the Irankuh Zn-Pb mine at 20 km south of Esfahan and 1 km northeast of Abnil in west-Central Iran. During mine excavation, the upper impervious bed of a confined aquifer was broken and water at high-pressure flowed into an open pit mine associated with the Kolahdarvazeh deposit. The inflow rates were 6.7 and 1.4 m(3)/s at the maximum and minimum quantities, respectively. Permeability, storage coefficient, thickness and initial head of the fully saturated confined aquifer were 3.5 × 10(-4) m/s, 0.2, 30 m and 60 m, respectively. The hydraulic heads as a function of time were monitored at four observation wells in the vicinity of the pit over 19 weeks and at an observation well near a test well over 21 h. In addition, by measuring the rate of pumping out from the pit sump, at a constant head (usually equal to height of the pit floor), the real inflow rates to the pit were monitored. The main innovations of this work were to make comparison between numerical modelling using a finite element software called SEEP/W and actual data related to inflow and extend the applicability of the numerical model. This model was further used to estimate the hydraulic heads at the observation wells around the pit over 19 weeks during mining operations. Data from a pump-out test and observation wells were used for model calibration and verification. In order to evaluate the model efficiency, the modelling results of inflow quantity and hydraulic heads were compared to those from analytical solutions, as well as the field data. The mean percent error in relation to field data for the inflow quantity was 0.108. It varied between 1.16 and 1.46 for hydraulic head predictions, which are much lower values than the mean percent errors resulted from the analytical solutions (from 1.8 to 5

  20. Analysis of two Pit-1 gene polymorphisms: Single nucleotide ...

    African Journals Online (AJOL)

    Pit-1 is a pituitary-specific transcription factor responsible for pituitary development and hormone expression in mammals. Pit-1 is a member of the POU domain containing proteins, a group of transcriptional regulators with a critical role in cell differentiation and proliferation. It was shown that this group of proteins control the ...

  1. The phylogenetic significance of vestured pits in Boraginaceae

    NARCIS (Netherlands)

    Rabaey, D.; Lens, F.; Smets, E.; Jansen, S.

    2010-01-01

    The bordered pit structure in tracheary elements of 105 Boraginaceae species is studied using scanning electron microscopy to examine the systematic distribution of vestured pits. Forty-three species out of 16 genera show a uniform presence of this feature throughout their secondary xylem. Most

  2. Modelling the filling rate of pit latrines | Brouckaert | Water SA

    African Journals Online (AJOL)

    Excreta (faeces and urine) that are deposited into a pit latrine are subject to biodegradation, which substantially reduces the volume that remains. On the other hand, other matter that is not biodegradable usually finds itsway into pit latrines. The net filling rate is thus dependent on both the rate of addition of material and its ...

  3. Sustainable Environmental Protection Using Modified Pit-Latrines

    NARCIS (Netherlands)

    Chaggu, E.J.

    2004-01-01

    Pit-latrines are on-site excreta disposal facilities widely used as anaerobic accumulation system for stabilizing human wastes like excreta, both in rural and urban settlements of developing countries. Flooding of pit-latrines is often a common phenomenon, especially in situations of high water

  4. Pit membranes of Ephedra resemble gymnosperms more than angiosperms

    Science.gov (United States)

    Roland Dute; Lauren Bowen; Sarah Schier; Alexa Vevon; Troy Best; Maria Auad; Thomas Elder; Pauline Bouche; Steven Jansen

    2014-01-01

    Bordered pit pairs of Ephedra species were characterized using different types of microscopy. Pit membranes contained tori that did not stain for lignin. SEM and AFM views of the torus surface showed no plasmodesmatal openings, but branched, secondary plasmodesmata were occasionally noted using TEM in conjunction with ultrathin sections. The margo consisted of radial...

  5. Inhibition of Copper Pitting Corrosion in Aggressive Potable Waters

    Directory of Open Access Journals (Sweden)

    Emily Sarver

    2012-01-01

    Full Text Available Copper pitting corrosion can lead to premature plumbing failures, and can be caused by aggressive potable waters characterized by high pH, free chlorine residual and low alkalinity. In such waters and under continuous flow, certain inhibitors including phosphate, silica or natural organic matter may greatly reduce pitting occurrence. In the current work, 1 mg/L phosphate (as P completely prevented initiation of pits, and 5 mg/L silica (as Si significantly decelerated pitting. However, much lower doses of these inhibitors had little benefit and actually accelerated the rate of attack in some cases. Effects of organic matter were dependent on both the type (e.g., natural versus ozonated humic substances and dosage. Dose-response effects of free chlorine and alkalinity were also investigated. Based on electrochemical data, pits initiated more rapidly with increased free chlorine, but even moderate levels of chlorine (~0.4 mg/L eventually caused severe pitting. High alkalinity decreased pit propagation rates but did not prevent pit formation.

  6. 241-AY-102 Leak Detection Pit Drain Line Inspection Report

    International Nuclear Information System (INIS)

    Boomer, Kayle D.; Engeman, Jason K.; Gunter, Jason R.; Joslyn, Cameron C.; Vazquez, Brandon J.; Venetz, Theodore J.; Garfield, John S.

    2014-01-01

    This document provides a description of the design components, operational approach, and results from the Tank AY-102 leak detection pit drain piping visual inspection. To perform this inspection a custom robotic crawler with a deployment device was designed, built, and operated by IHI Southwest Technologies, Inc. for WRPS to inspect the 6-inch leak detection pit drain line

  7. Pitting corrosion of copper. An equilibrium - mass transport study

    Energy Technology Data Exchange (ETDEWEB)

    Taxen, C

    1996-11-01

    A mathematical model for the propagation of corrosion pits on copper is described. The model is used to predict the potentials below which copper is immune to pitting. The criteria used for immunity against pitting is that the volume of the cuprous oxide formed at the site of the metal oxidation at the bottom of a corrosion pit must be smaller than the volume of the oxidised metal. Equal volumes would give a complete coverage of the metal in a pit by adherent cuprous oxide and propagation would not be possible. For potentials where copper is not immune to pitting an estimate of the maximum growth rate is given. The model uses equilibrium data and diffusion coefficients and calculates the stationary concentration profiles from the bulk water outside a corrosion pit to the site of the metal dissolution at the bottom a corrosion pit. Precipitation of oxides as well as of basic salts of copper is considered. A total of 26 aqueous species are considered in waters with compositions ranging from those of tap waters to that of sea water. Calculations are made for the temperatures 25 deg C and 75 deg C. 38 refs, 60 figs, 17 tabs

  8. Liquid waste processing from TRIGA spent fuel storage pits

    International Nuclear Information System (INIS)

    Buchtela, Karl

    1988-01-01

    At the Atominstitute of the Austrian Universities and also at other facilities running TRIGA reactors, storage pits for spent fuel elements are installed. During the last revision procedure, the reactor group of the Atominstitute decided to refill the storage pits and to get rid of any contaminated storage pit water. The liquid radioactive waste had been pumped to polyethylene vessels for intermediate storage before decontamination and release. The activity concentration of the storage pit water at the Aominstitute after a storage period of several years was about 40 kBq/l, the total amount of liquid in the storage pits was about 0.25 m 3 . It was attempted to find a simple and inexpensive method to remove especially the radioactive Cesium from the waste solution. Different methods for decontamination like distillation, precipitation and ion exchange are discussed

  9. Stochastic models for predicting pitting corrosion damage of HLRW containers

    International Nuclear Information System (INIS)

    Henshall, G.A.

    1991-10-01

    Stochastic models for predicting aqueous pitting corrosion damage of high-level radioactive-waste containers are described. These models could be used to predict the time required for the first pit to penetrate a container and the increase in the number of breaches at later times, both of which would be useful in the repository system performance analysis. Monte Carlo implementations of the stochastic models are described, and predictions of induction time, survival probability and pit depth distributions are presented. These results suggest that the pit nucleation probability decreases with exposure time and that pit growth may be a stochastic process. The advantages and disadvantages of the stochastic approach, methods for modeling the effects of environment, and plans for future work are discussed

  10. PITTING CORROSION OF STAINLESS STEEL AT THE VARIOUS SURFACE TREATMENT

    Directory of Open Access Journals (Sweden)

    Viera Zatkalíková

    2011-09-01

    Full Text Available The stainless steel surface treatment is very important with regard to its pitting corrosion susceptibility. An effect of various types surfacing on pitting corrosion resistance of AISI 304stainless steel is investigated in this work. The samples of the tested material are turned, blasted, peened, grinded and a half of them are pickled to achieve higher purity of surfaces and better quality of passive film. Eight types of different finished surfaces are tested by electrochemical and immersion tests to determine corrosion behaviour in conditions where pitting is evoked by controlled potential and second by solution with high redox potential. By this way the effect of mechanical and chemical surface treatment on the resistance to pitting corrosion, character, size and shape of pits are compared in the conditions of different mechanisms of corrosion process.

  11. Flare pit reclamation in British Columbia

    International Nuclear Information System (INIS)

    Mitchell, J.D.

    1997-01-01

    The legislative acts and policies administered by the Pollution Prevention program of the B.C. Ministry of Environment, Lands and Parks, (MELP) were reviewed. MELP is responsible for protecting land, water, air and living resources. Past oil and gas activities have left behind high levels of hazardous materials spills on the land which can pose a risk to human health. Flare pits are also a potential source of soil and groundwater contamination, therefore proper management and remediation of these sites is critical to ensuring that adverse impacts do not occur due to contamination of the sites. MELP has created a Contaminated Sites Regulation (CSR) which presents a consistent approach to ensuring protection of human health, the environment and property. This paper explores key provisions of the CSR, the prescribed contaminated sites management process and compares the B.C. legislation with that of neighbouring Alberta. 5 refs., 1 tab., 4 figs

  12. Optic nerve head pit-associated maculopathy

    International Nuclear Information System (INIS)

    Beltrán Sainz, Raisa Ivis; Hernández Baguer, Raisa; Gonzales Díaz, Rafael Ernesto; Hernández Martínez, Rocío; Galindo Reimond, Kenia

    2016-01-01

    A literature review was made to expand knowledge on the optic nerve head pit-related maculopathy, its physiopathology and main manifestations, clinical and angiographic diagnosis, optical coherence tomography, and to describe some of the treatments recently used worldwide. The current therapeutic tendencies were taken into account. The fundamental sources of information were scientific articles from journals in PubMED and Cochrane databases as well as basic texts which dealt with this topic in the last five years through Google search engine. Despite the rare occurrence of the disease, its management may be difficult particularly in macular effect cases. This paper confirmed that most of the studies used small samples, were retrospective, non-comparative and non-randomized. However, some therapeutic modalities were found, which have been used for years and also descriptions of new techniques that require further research. There is no consensus on the ideal treatment protocol for this disease. (author)

  13. Radio Propagation in Open-pit Mines

    DEFF Research Database (Denmark)

    Portela Lopes de Almeida, Erika; Caldwell, George; Rodriguez Larrad, Ignacio

    2017-01-01

    In this paper we present the results of an extensive measurement campaign performed at two large iron ore mining centers in Brazil at the 2.6 GHz band. Although several studies focusing on radio propagation in underground mines have been published, measurement data and careful analyses for open......-pit mines are still scarce. Our results aim at filling this gap in the literature. The research is motivated by the ongoing mine automation initiatives, where connectivity becomes critical. This paper presents the first set of results comprising measurements under a gamut of propagation conditions. A second...... paper detailing sub-GHz propagation is also in preparation. The results indicate that conventional wisdom is wrong, in other words, radio-frequency (RF) propagation in surface mines can be far more elaborate than plain free-space line-of-sight conditions. Additionally, the old mining adage “no two mines...

  14. Construction of the KUT test pits

    International Nuclear Information System (INIS)

    Knapp, K.E.; Bush, W.E.

    1976-09-01

    Models are required to calibrate spectral logging systems to differentiate between U, Th, and K (''KUT''), in order to determine the grade of low-grade U deposits. The models were constructed by excavating three pits, emplacing three form tanks (11 ft long, 4 ft dia culvert) with 4-in. dia central holes, and pouring the following zones: 3-ft concrete lower barren zone, a 5-ft ore zone, and a final 3-ft upper barren zone. The U ore zone comprised 0.33 percent U 3 O 8 Climax ore, sand, cement, and water; the Th ore zone comprised monazite sands, plaster sand, cement, and water; and the K ore zone comprised feldspar, cement, and water. Form pipes were used to form the central holes. Analyses were made of samples taken from the zones

  15. Amchitka Mud Pit Sites 2006 Post-Closure Monitoring and Inspection Report, Amchitka Island, Alaska, Rev. No.: 0

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, Patrick

    2006-09-01

    In 2001, the U.S. Department of Energy (DOE), National Nuclear Security Administration (NNSA/NSO) remediated six areas associated with Amchitka mud pit release sites located on Amchitka Island, Alaska. This included the construction of seven closure caps. To ensure the integrity and effectiveness of remedial action, the mud pit sites are to be inspected every five years as part of DOE's long-term monitoring and surveillance program. In August of 2006, the closure caps were inspected in accordance with the ''Post-Closure Monitoring and Inspection Plan for Amchitka Island Mud Pit Release Sites'' (Rev. 0, November 2005). This post-closure monitoring report provides the 2006 cap inspection results.

  16. Comparative Performance of Acoustic-tagged and PIT-tagged Juvenile Salmonids

    Energy Technology Data Exchange (ETDEWEB)

    Hockersmith, Eric E.; Brown, Richard S.; Liedtke, Theresa L.

    2008-02-01

    Numerous research tools and technologies are currently being used to evaluate fish passage and survival to determine the impacts of the Federal Columbia River Power System (FCRPS) on endangered and threatened juvenile salmonids, including PIT tags, balloon tags, hydroacoustic evaluations, radio telemetry, and acoustic telemetry. Each has advantages and disadvantages, but options are restricted in some situations because of limited capabilities of a specific technology, lack of detection capability downstream, or availability of adequate numbers of fish. However, there remains concern about the comparative effects of the tag or the tagging procedure on fish performance. The recently developed Juvenile Salmonid Acoustic Telemetry System (JSATS) acoustic transmitter is the smallest active acoustic tag currently available. The goal of this study was to determine whether fish tagged with the JSATS acoustic-telemetry tag can provide unbiased estimates of passage behavior and survival within the performance life of the tag. We conducted both field and laboratory studies to assess tag effects. For the field evaluation we released a total of 996 acoustic-tagged fish in conjunction with 21,026 PIT-tagged fish into the tailrace of Lower Granite Dam on 6 and 13 May. Travel times between release and downstream dams were not significantly different for the majority of the reaches between acoustic-tagged and PIT-tagged fish. In addition to the field evaluation, a series of laboratory experiments were conducted to determine if growth and survival of juvenile Chinook salmon surgically implanted with acoustic transmitters is different than untagged or PIT tagged juvenile Chinook salmon. Only yearling fish with integrated and non-integrated transmitters experienced mortalities, and these were low (<4.5%). Mortality among sub-yearling control and PIT-tag treatments ranged up to 7.7% while integrated and non-integrated treatments had slightly higher rates (up to 8.3% and 7

  17. Pitting corrosion of copper. An equilibrium - mass transport study

    International Nuclear Information System (INIS)

    Taxen, C.

    2002-08-01

    A mathematical model for the propagation of corrosion pits is described and used to calculate the potentials below which copper is immune to pitting. The model uses equilibrium data and diffusion coefficients and calculates the stationary concentration profiles of 26 aqueous species from the bulk water outside a corrosion pit to the site of the metal dissolution. Precipitation of oxides and salts of copper is considered. Studied conditions include water compositions from tap waters to seawater at the temperatures 25 deg C and 75 deg C. Carbonate and sulphate are aggressive towards copper because of complex formation with divalent copper. Carbonate is less aggressive in a corrosion pit than outside at the pH of the bulk. Carbonate carries acidity out from the pit, favours oxide formation and may prevent the initiation of acidic corrosion pits. The concentration profiles are used to estimate the maximum propagation rates for a corrosion pit. A high potential is found to be the most important factor for the rate of propagation. The levels of potential copper can sustain, as corrosion potentials are discussed in terms of the stability of cuprous oxide as a cathode material for oxygen reduction relative to non-conducting cupric phases

  18. Pit above the lesser tuberosity in axial view radiography.

    Science.gov (United States)

    Cho, Jae-Ho; Han, Kyeong-Jin; Lee, Doo-Hyung; Chung, Nam-Su; Park, Do Young

    2015-02-01

    This study examined the relationship between the presence of a pit above the lesser tuberosity on axial view radiographs and rotator cuff tears and compared the demographic data between groups according to the presence of a pit above the lesser tuberosity. The hypothesis of this study was that the radiographic finding of a pit above the lesser tuberosity is related to rotator cuff tears. For 112 patients with a symptomatic rotator cuff tear, plain radiographs of the symptomatic shoulder (tear side radiographs) and plain radiographs of the asymptomatic contralateral shoulder (no-tear side radiographs) were assessed. Seventeen radiological findings, including a pit above the lesser tuberosity, osteophytes, subchondral cysts, and sclerosis, were recorded by one blinded observer. Demographic data such as age, duration of symptoms, sex, arm dominance, smoking history, trauma history, American Shoulder and Elbow Surgeons score, Constant score, and involved tendon were collected. A pit above the lesser tuberosity was noted on tear side radiographs of 40 patients (35.7 %) and on the no-tear side radiographs of 27 patients (24.1 %), representing a significant difference (P = 0.040). A pit associated with a rotator cuff tear was observed more often in the dominant arm (P = 0.040) and more often in patients with less previous trauma (P = 0.024). A pit above the lesser tuberosity on axial view radiography was associated with a rotator cuff tear and occurred more often in the dominant arm of patients who had no trauma history. Prognostic study, Level III.

  19. Pitting corrosion of copper. An equilibrium - mass transport study

    Energy Technology Data Exchange (ETDEWEB)

    Taxen, C. [Swedish Corrosion Inst., Stockholm (Sweden)

    2002-08-01

    A mathematical model for the propagation of corrosion pits is described and used to calculate the potentials below which copper is immune to pitting. The model uses equilibrium data and diffusion coefficients and calculates the stationary concentration profiles of 26 aqueous species from the bulk water outside a corrosion pit to the site of the metal dissolution. Precipitation of oxides and salts of copper is considered. Studied conditions include water compositions from tap waters to seawater at the temperatures 25 deg C and 75 deg C. Carbonate and sulphate are aggressive towards copper because of complex formation with divalent copper. Carbonate is less aggressive in a corrosion pit than outside at the pH of the bulk. Carbonate carries acidity out from the pit, favours oxide formation and may prevent the initiation of acidic corrosion pits. The concentration profiles are used to estimate the maximum propagation rates for a corrosion pit. A high potential is found to be the most important factor for the rate of propagation. The levels of potential copper can sustain, as corrosion potentials are discussed in terms of the stability of cuprous oxide as a cathode material for oxygen reduction relative to non-conducting cupric phases.

  20. Corrosion pit depth extreme value prediction from limited inspection data

    International Nuclear Information System (INIS)

    Najjar, D.; Bigerelle, M.; Iost, A.; Bourdeau, L.; Guillou, D.

    2004-01-01

    Passive alloys like stainless steels are prone to localized corrosion in chlorides containing environments. The greater the depth of the localized corrosion phenomenon, the more dramatic the related damage that can lead to a structure weakening by fast perforation. In practical situations, because measurements are time consuming and expensive, the challenge is usually to predict the maximum pit depth that could be found in a large scale installation from the processing of a limited inspection data. As far as the parent distribution of pit depths is assumed to be of exponential type, the most successful method was found in the application of the statistical extreme-value analysis developed by Gumbel. This study aims to present a new and alternative methodology to the Gumbel approach with a view towards accurately estimating the maximum pit depth observed on a ferritic stainless steel AISI 409 subjected to an accelerated corrosion test (ECC1) used in automotive industry. This methodology consists in characterising and modelling both the morphology of pits and the statistical distribution of their depths from a limited inspection dataset. The heart of the data processing is based on the combination of two recent statistical methods that avoid making any choice about the type of the theoretical underlying parent distribution of pit depths: the Generalized Lambda Distribution (GLD) is used to model the distribution of pit depths and the Bootstrap technique to determine a confidence interval on the maximum pit depth. (authors)

  1. Pitting by corrosion in aluminium and Al-6201 alloy

    International Nuclear Information System (INIS)

    Vera, R.; Schrebler, R.; Layana, G.; Orellana, F.; Olguin, A.

    1998-01-01

    The susceptibility of pure aluminum 6201 alloy to pitting was investigated in sodium chloride solutions through determination of the corrosion, repassivation and pitting potentials. Potentiodynamic polarization including scratching techniques were employed being also determined the type and relative amount of corrosion damage to the metals. The morphology of the attach was determined using scanning electrons microscopy (SEM). The results showed a similar performance for aluminum 6201 alloy and aluminum. It was also observed that an increase in chloride concentration resulted in a decrease in the corrosion, pitting and repassivation potentials of both materials. (Author) 19 refs

  2. Investigating oiled birds from oil field waste pits

    International Nuclear Information System (INIS)

    Gregory, D.G.; Edwards, W.C.

    1991-01-01

    Procedures and results of investigations concerning the oiling of inland raptors, migratory water-fowl and other birds are presented. Freon washings from the oiled birds and oil from the pits were analyzed by gas chromatography. In most instances the source of the oil could be established by chromatographic procedures. The numbers of birds involved (including many on the endangered species list) suggested the need for netting or closing oil field waste pits and mud disposal pits. Maintaining a proper chain of custody was important

  3. Seasonal movement of Dolly Varden and cutthroat trout with respect to stream discharge in a second–order stream in South Alaska

    Science.gov (United States)

    M.D. Bryant; M.D. Lukey; J.P. McDonell; R.A. Gubernick; R.S. Aho

    2009-01-01

    The relationship between the movement of small (,150-mm) Dolly Varden Salvelinus malma and cutthroat trout Oncorhynchus clarkii and stream discharge is not well known in streams of southeast Alaska. We measured movement in a small headwater stream using passive integrated transponder (PIT) tags and stationary antennas to record time and date of movement. Fish with PIT...

  4. Movement ecology and seasonal distribution of mountain yellow-legged frogs, Rana muscosa, in a high-elevation Sierra Nevada basin.

    Science.gov (United States)

    K.L. Pope; K.R. Matthews

    2001-01-01

    Movement ecology and seasonal distribution of mountain yellow-legged frogs (Rana muscosa) in Dusy Basin (3470 m), Kings Canyon National Park, California, were characterized using passive integrated transponder (PIT) surveys and visual encounter surveys. We individually PIT-tagged 500 frogs during the summers of 1997 and 1998 and monitored these individuals during seven...

  5. Comparative Survival Study (CSS) of Hatchery PIT-tagged Spring/Summer Chinook; Migration Years 1997-2002 Mark/Recapture Activities and Bootstrap Analysis, 2003-2004 Biennial Report.

    Energy Technology Data Exchange (ETDEWEB)

    Berggren, Thomas J.; Franzoni, Henry; Basham, Larry R. (Columbia Basin Fish and Wildlife Authority, Fish Passage Center, Portland, OR)

    2003-11-01

    The Comparative Survival Study (CSS) was initiated in 1996 as a multi-year program of the fishery agencies and tribes to estimate survival rates over different life stages for spring and summer Chinook (hereafter, Chinook) produced in major hatcheries in the Snake River basin and from selected hatcheries in the lower Columbia River. Much of the information evaluated in the CSS is derived from fish tagged with Passive Integrated Transponder (PIT) tags. A comparison of survival rates of Chinook marked in two different regions (which differ in the number of dams Chinook have to migrate through) provides insight into the effects of the Snake/Columbia hydroelectric system (hydrosystem). The CSS also compares the smolt-to-adult survival rates (SARs) for Snake River Chinook that were transported versus those that migrated in-river to below Bonneville Dam. Additional comparisons can be made within in-river experiences as well as comparison between the different collector projects from which smolts are transported. CSS also compares survival rates for wild Snake River spring and summer Chinook. These comparisons generate information regarding the relative effects of the current management actions used to recover this listed species. Scientists and managers have recently emphasized the importance of delayed hydrosystem mortality to long-term management decisions. Delayed hydrosystem mortality may be related to the smolts experience in the Federal Columbia River Power System, and could occur for both smolts that migrate in-river and smolts that are transported. The CSS PIT tag information on in-river survival rates and smolt-to-adult survival rates (SARs) of transported and in-river fish are relevant to estimation of ''D'', which partially describes delayed hydrosystem mortality. The parameter D is the differential survival rate of transported fish relative to fish that migrate in-river, as measured from below Bonneville Dam to adults returning to Lower

  6. Assessment of Astrid reactor pit design options

    International Nuclear Information System (INIS)

    Verpoest, Thomas; Villedieu, Alexandre; Robin, Jean-Charles

    2014-01-01

    Answering the French Act of the 28. of June 2006 about nuclear materials and waste management, the ASTRID (Advanced Sodium Technological Reactor for Industrial Demonstration) Project has the objectives to demonstrate the industrial feasibility based on identified domains (safety, operability, economy) of Sodium-cooled Fast Reactor and to perform transmutation demonstrations. The pre-conceptual design, started in 2010, considers several reactor pit design options. One of the objectives is to define a reference configuration for the ASTRID project which is able to answer safety and design requirements. The components addressed in this article are: the safety vessel and the Decay Heat Removal system through the main vessel. The core catcher associated to the different configurations studied in this article is an internal core catcher (inside the main vessel). This article deals with the different locations of the DHR through the main vessel and the type of the safety vessel (supported versus suspended vessel). These options are studied in order to establish the advantages and drawbacks of the different configurations in terms of economy, safety, In Service Inspection and Repair (ISIR), operability, robustness, and project risk (authors)

  7. Optimization of coal recovery from open pits

    Energy Technology Data Exchange (ETDEWEB)

    Kim, C; Wolff, S F; Baafi, E Y; Cervantes, J A; Coates, D F

    1979-02-01

    The design techniques of the Pit Slope Manual were successfully applied in a case study concerned with optimizing the design of coal mines. A steeply dipping multiple seam deposit, being mined by the truck-shovel combination, was selected for the study. The criterion for optimum slopes was based on the financial consequences of each design, i.e., the resultant benefits and costs. Three alternative designs were analyzed. The first had an average highwall slope angle of 28 degrees and a final height of 290 m. The second had a 35 degrees slope angle and a 305-m wall height. The third had a 45 degrees slope angle and a 320-m wall height. Trade-off between benefits and increased cost of slope instability inherent in steeper slope angles was analyzed for the entire mine life through computer simulation of actual mining operations. The cost models developed were (1) No Cost, (2) Clean-up, (3) Lost Coal, (4) Early Mining, (5) Mine Abandonment, (6) Increased Haulage, and (7) Haul Road Re-establishment. (8 refs.)

  8. Comparison of Microchip Transponder and Noncontact Infrared Thermometry with Rectal Thermometry in Domestic Swine (Sus scrofa domestica)

    Science.gov (United States)

    Jara, Amanda L; Hanson, Jarod M; Gabbard, Jon D; Johnson, Scott K; Register, Emery T; He, Biao

    2016-01-01

    During disease outbreaks, core temperature is a useful health metric in swine, due to the presence of pyrexia especially during the acute phase of infection. Despite technologic advances in other facets of swine production and health management, rectal thermometry continues to be the ‘gold standard’ for measuring core body temperature. However, for various reasons, collecting rectal temperatures can be difficult and unsafe depending on the housing modality. In addition, the delay between insertion of the rectal thermometer and obtaining a reading can affect measurement accuracy, especially when the pig requires physical restraint. Clearly safer, faster, and more accurate and precise temperature acquisition methods that necessitate minimal or no handling of swine are needed. We therefore compared rectal thermometers, subcutaneous microchips, and an inexpensive handheld infrared thermometer by measuring the core body temperature of 24 male castrated piglets at random intervals over a 5-wk period. The core body temperature (mean ± 1 SD) was 39.3 ± 0.5 °C by rectal thermometry, 39.0 ± 0.7 °C by microchip transponder, and 34.3 ± 1.0 °C by infrared thermometry; these 3 values differed significantly. Although the readings obtain by using infrared thermometry were numerically lower than those from the other methods, it is arguably the safest method for assessing the core temperature of swine and showed strong relative correlation with rectal temperature. PMID:27657715

  9. Stochastic production phase design for an open pit mining complex with multiple processing streams

    Science.gov (United States)

    Asad, Mohammad Waqar Ali; Dimitrakopoulos, Roussos; van Eldert, Jeroen

    2014-08-01

    In a mining complex, the mine is a source of supply of valuable material (ore) to a number of processes that convert the raw ore to a saleable product or a metal concentrate for production of the refined metal. In this context, expected variation in metal content throughout the extent of the orebody defines the inherent uncertainty in the supply of ore, which impacts the subsequent ore and metal production targets. Traditional optimization methods for designing production phases and ultimate pit limit of an open pit mine not only ignore the uncertainty in metal content, but, in addition, commonly assume that the mine delivers ore to a single processing facility. A stochastic network flow approach is proposed that jointly integrates uncertainty in supply of ore and multiple ore destinations into the development of production phase design and ultimate pit limit. An application at a copper mine demonstrates the intricacies of the new approach. The case study shows a 14% higher discounted cash flow when compared to the traditional approach.

  10. Influence of remanent magnetization on pitting corrosion in pipeline steel

    Energy Technology Data Exchange (ETDEWEB)

    Espina-Hernandez, J. H. [ESIME Zacatenco, SEPI Electronica Instituto Politecnico Nacional Mexico, D. F. (Mexico); Caleyo, F.; Hallen, J. M. [DIM-ESIQIE, Instituto Politecnico Nacional Mexico D. F. (Mexico); Lopez-Montenegro, A.; Perez-Baruch, E. [Pemex Exploracion y Produccion, Region Sur Villahermosa, Tabasco (Mexico)

    2010-07-01

    Statistical studies performed in Mexico indicate that leakage due to external pitting corrosion is the most likely cause of failure of buried pipelines. When pipelines are inspected with the magnetic flux leakage (MFL) technology, which is routinely used, the magnetization level of every part of the pipeline changes as the MFL tool travels through it. Remanent magnetization stays in the pipeline wall after inspection, at levels that may differ from a point to the next. This paper studies the influence of the magnetic field on pitting corrosion. Experiments were carried out on grade 52 steel under a level of remanent magnetization and other laboratory conditions that imitated the conditions of a pipeline after an MLF inspection. Non-magnetized control samples and magnetized samples were subjected to pitting by immersion in a solution containing chlorine and sulfide ions for seven days, and then inspected with optical microscopy. Results show that the magnetic field in the pipeline wall significantly increases pitting corrosion.

  11. Studies in pitting corrosion on archaeological bronzes. Copper

    International Nuclear Information System (INIS)

    Bresle, Aa.; Saers, J.; Arrhenius, B.

    1983-01-01

    Copper has been proposed as a canister material for use in the long-term storage of radioactive waste from nuclear power reactors. The storage period has been set to at least 100 000 years, during which time the copper cylinders must remain intact so that the contained waste has no possibility of leaking out. In this work, the pitting factor in archaelogical copper objects have been determined. The absolute values of the pitting factor obtained are generally very low. In the case of the most thoroughly studied material the pitting factor is only slightly more than three units. Nor does the native copper, with a presumed burial period of about 8000 years, exhibit particularly high values. In summary, it can therefore be concluded that the present study does not provide support for the assumption of extremely high pitting factors in copper-base material that has been buried for periods of several millenia. (G.B.)

  12. Effect of microcrystallization on pitting corrosion of pure aluminium

    International Nuclear Information System (INIS)

    Meng Guozhe; Wei Liyan; Zhang Tao; Shao Yawei; Wang Fuhui; Dong Chaofang; Li Xiaogang

    2009-01-01

    A microcrystalline aluminium film with grain size of about 400 nm was prepared by magnetron sputtering technique. Its corrosion behaviour was investigated in NaCl containing acidic solution by means of potentiodynamic polarization curves and electrochemical noise (EN). The polarization results indicated that the corrosion potential of the sample shifted towards more positive direction, while its corrosion current density decreased compared with that of pure coarse-grain Al. The EN analysis based on stochastic model demonstrated that there existed two kinds of effect of microcrystallization on the pitting behaviour of pure aluminium: (1) the rate of pit initiation is accelerated, (2) the pit growth process was impeded. This leads to the enhancement of pitting resistance for the microcrystallized aluminium.

  13. A critical analysis of physiochemical properties influencing pit latrine ...

    African Journals Online (AJOL)

    African Journal of Environmental Science and Technology ... pit emptying devices and poor faecal sludge disposal contributing to environmental pollution. ... from each depth using a manual sampling tool and emptied into a plastic container.

  14. 105-KW Sandfilter Backwash Pit sludge volume calculation

    International Nuclear Information System (INIS)

    Dodd, E.N. Jr.

    1995-01-01

    The volume of sludge contained in the 100-KW Sandfilter Backwash Pit (SFBWP) was calculated from depth measurements of the sludge, pit dimension measurements and analysis of video tape recordings taken by an underwater camera. The term sludge as used in this report is any combination of sand, sediment, or corrosion products visible in the SFBWP area. This work was performed to determine baseline volume for use in determination of quantities of uranium and plutonium deposited in the pit from sandfilter backwashes. The SFBWP has three areas where sludge is deposited: (1) the main pit floor, (2) the transfer channel floor, and (3) the surfaces and structures in the SFBWP. The depths of sludge and the uniformity of deposition varies significantly between these three areas. As a result, each of the areas was evaluated separately. The total volume of sludge determined was 3.75 M 3 (132.2 ft 3 )

  15. Application of Surpac and Whittle Software in Open Pit Optimisation ...

    African Journals Online (AJOL)

    Michael

    2015-06-01

    Jun 1, 2015 ... The deposit has undergone intense weathering, forming an oxidised gold deposit ... total of 82 optimal pit outlines were generated using the 3D Lerchs-Grossmann algorithm. ... are also widely accepted in the mining industry.

  16. Template measurement for plutonium pit based on neural networks

    International Nuclear Information System (INIS)

    Zhang Changfan; Gong Jian; Liu Suping; Hu Guangchun; Xiang Yongchun

    2012-01-01

    Template measurement for plutonium pit extracts characteristic data from-ray spectrum and the neutron counts emitted by plutonium. The characteristic data of the suspicious object are compared with data of the declared plutonium pit to verify if they are of the same type. In this paper, neural networks are enhanced as the comparison algorithm for template measurement of plutonium pit. Two kinds of neural networks are created, i.e. the BP and LVQ neural networks. They are applied in different aspects for the template measurement and identification. BP neural network is used for classification for different types of plutonium pits, which is often used for management of nuclear materials. LVQ neural network is used for comparison of inspected objects to the declared one, which is usually applied in the field of nuclear disarmament and verification. (authors)

  17. New diagnostic technology and hidden pits and fissures caries

    OpenAIRE

    Fabrizio Guerra; Marta Mazur; Francesca Rinaldo; Denise Corridore; Daniele Salvi; Debora Pasqualotto; Gianna Maria Nardi; Livia Ottolenghi

    2015-01-01

    The accuracy in pits and fissures caries detection is of paramount importance in dental caries primary and secondary prevention. A combination of visual examination and probing is currently the mainstay of occlusal caries diagnosis. Unfortunately, these types of inspection alone may leave a certain number of pit and fissure caries undetected. The Vista Cam iX fluorescence camera (Durr Dental, Bietigheim-Bissingen, Germany) is a novel dental diagnostic tool for quantitative assessment of denta...

  18. Ecological geology environmental assessment of open-pit mines

    International Nuclear Information System (INIS)

    Dong Shuangfa; Jiang Xue

    2010-01-01

    In this paper, there is a detail description of ecological geology environmental assessment of open-pit mines, including method, process and results. We took ecological geology environmental assessment work on the base of the results of some open-pit mines such as extremely low content magnetite in Hebei Province, inducted and summarized the ecological geology environment quality. The results are reasonable. It provides basic data for the second mines programming in Hebei Province. (authors)

  19. Force-displacement measurements of earlywood bordered pits using a mesomechanical tester

    Science.gov (United States)

    Samuel L. Zelinka; Keith J. Bourne; John C. Hermanson; Samuel V. Glass; Adriana Costa; Alex C. Wiedenhoeft

    2015-01-01

    The elastic properties of pit membranes are reported to have important implications in understanding air-seeding phenomena in gymnosperms, and pit aspiration plays a large role in wood technological applications such as wood drying and preservative treatment. Here we present force–displacement measurements for pit membranes of circular bordered pits, collected on a...

  20. Statistical characterization of pitting corrosion process and life prediction

    International Nuclear Information System (INIS)

    Sheikh, A.K.; Younas, M.

    1995-01-01

    In order to prevent corrosion failures of machines and structures, it is desirable to know in advance when the corrosion damage will take place, and appropriate measures are needed to mitigate the damage. The corrosion predictions are needed both at development as well as operational stage of machines and structures. There are several forms of corrosion process through which varying degrees of damage can occur. Under certain conditions these corrosion processes at alone and in other set of conditions, several of these processes may occur simultaneously. For a certain type of machine elements and structures, such as gears, bearing, tubes, pipelines, containers, storage tanks etc., are particularly prone to pitting corrosion which is an insidious form of corrosion. The corrosion predictions are usually based on experimental results obtained from test coupons and/or field experiences of similar machines or parts of a structure. Considerable scatter is observed in corrosion processes. The probabilities nature and kinetics of pitting process makes in necessary to use statistical method to forecast the residual life of machine of structures. The focus of this paper is to characterization pitting as a time-dependent random process, and using this characterization the prediction of life to reach a critical level of pitting damage can be made. Using several data sets from literature on pitting corrosion, the extreme value modeling of pitting corrosion process, the evolution of the extreme value distribution in time, and their relationship to the reliability of machines and structure are explained. (author)

  1. Deterministic chaos in the pitting phenomena of passivable alloys

    International Nuclear Information System (INIS)

    Hoerle, Stephane

    1998-01-01

    It was shown that electrochemical noise recorded in stable pitting conditions exhibits deterministic (even chaotic) features. The occurrence of deterministic behaviors depend on the material/solution severity. Thus, electrolyte composition ([Cl - ]/[NO 3 - ] ratio, pH), passive film thickness or alloy composition can change the deterministic features. Only one pit is sufficient to observe deterministic behaviors. The electrochemical noise signals are non-stationary, which is a hint of a change with time in the pit behavior (propagation speed or mean). Modifications of electrolyte composition reveals transitions between random and deterministic behaviors. Spontaneous transitions between deterministic behaviors of different features (bifurcation) are also evidenced. Such bifurcations enlighten various routes to chaos. The routes to chaos and the features of chaotic signals allow to suggest the modeling (continuous and discontinuous models are proposed) of the electrochemical mechanisms inside a pit, that describe quite well the experimental behaviors and the effect of the various parameters. The analysis of the chaotic behaviors of a pit leads to a better understanding of propagation mechanisms and give tools for pit monitoring. (author) [fr

  2. Integration

    DEFF Research Database (Denmark)

    Emerek, Ruth

    2004-01-01

    Bidraget diskuterer de forskellige intergrationsopfattelse i Danmark - og hvad der kan forstås ved vellykket integration......Bidraget diskuterer de forskellige intergrationsopfattelse i Danmark - og hvad der kan forstås ved vellykket integration...

  3. Numerical Investigation on Stress Concentration of Tension Steel Bars with One or Two Corrosion Pits

    Directory of Open Access Journals (Sweden)

    Jian Hou

    2015-01-01

    Full Text Available Pitting corrosion has been observed in steel bars of existing reinforced concrete (RC structures in different erosion environments and has been identified as a potential origin for fatigue crack nucleation. In the present study, under uniaxial tension loading, stress distribution in the steel bars with one or two semiellipsoidal corrosion pits has systematically been investigated by conducting a series of three-dimensional semiellipsoidal pitted models. Based on the finite element analyses, it is shown that stress concentration factor (SCF increases linearly with increasing pit aspect ratio (a/b and increases nonlinearly with increasing pit relative depth (a/R for single corrosion pit problem. For double corrosion pits problem, the SCF decreases nonlinearly with increasing angle of two transverse pits (θ. The interaction of two longitudinal pits can be ignored in the calculation of SCF even if the distance of two pits (d is very small.

  4. [Integrity].

    Science.gov (United States)

    Gómez Rodríguez, Rafael Ángel

    2014-01-01

    To say that someone possesses integrity is to claim that that person is almost predictable about responses to specific situations, that he or she can prudentially judge and to act correctly. There is a closed interrelationship between integrity and autonomy, and the autonomy rests on the deeper moral claim of all humans to integrity of the person. Integrity has two senses of significance for medical ethic: one sense refers to the integrity of the person in the bodily, psychosocial and intellectual elements; and in the second sense, the integrity is the virtue. Another facet of integrity of the person is la integrity of values we cherish and espouse. The physician must be a person of integrity if the integrity of the patient is to be safeguarded. The autonomy has reduced the violations in the past, but the character and virtues of the physician are the ultimate safeguard of autonomy of patient. A field very important in medicine is the scientific research. It is the character of the investigator that determines the moral quality of research. The problem arises when legitimate self-interests are replaced by selfish, particularly when human subjects are involved. The final safeguard of moral quality of research is the character and conscience of the investigator. Teaching must be relevant in the scientific field, but the most effective way to teach virtue ethics is through the example of the a respected scientist.

  5. A Comparison of Vibration and Oil Debris Gear Damage Detection Methods Applied to Pitting Damage

    Science.gov (United States)

    Dempsey, Paula J.

    2000-01-01

    Helicopter Health Usage Monitoring Systems (HUMS) must provide reliable, real-time performance monitoring of helicopter operating parameters to prevent damage of flight critical components. Helicopter transmission diagnostics are an important part of a helicopter HUMS. In order to improve the reliability of transmission diagnostics, many researchers propose combining two technologies, vibration and oil monitoring, using data fusion and intelligent systems. Some benefits of combining multiple sensors to make decisions include improved detection capabilities and increased probability the event is detected. However, if the sensors are inaccurate, or the features extracted from the sensors are poor predictors of transmission health, integration of these sensors will decrease the accuracy of damage prediction. For this reason, one must verify the individual integrity of vibration and oil analysis methods prior to integrating the two technologies. This research focuses on comparing the capability of two vibration algorithms, FM4 and NA4, and a commercially available on-line oil debris monitor to detect pitting damage on spur gears in the NASA Glenn Research Center Spur Gear Fatigue Test Rig. Results from this research indicate that the rate of change of debris mass measured by the oil debris monitor is comparable to the vibration algorithms in detecting gear pitting damage.

  6. Risk assessment to groundwater of pit latrine rural sanitation policy in developing country settings.

    Science.gov (United States)

    Back, Jan O; Rivett, Michael O; Hinz, Laura B; Mackay, Nyree; Wanangwa, Gift J; Phiri, Owen L; Songola, Chrispine Emmanuel; Thomas, Mavuto A S; Kumwenda, Steve; Nhlema, Muthi; Miller, Alexandra V M; Kalin, Robert M

    2018-02-01

    Parallel global rise in pit-latrine sanitation and groundwater-supply provision is of concern due to the frequent spatial proximity of these activities. Study of such an area in Malawi has allowed understanding of risks posed to groundwater from the recent implementation of a typical developing-country pit-latrine sanitation policy to be gained. This has assisted the development of a risk-assessment framework approach pragmatic to regulatory-practitioner management of this issue. The framework involves water-supply and pit-latrine mapping, monitoring of key groundwater contamination indicators and surveys of possible environmental site-condition factors and culminates in an integrated statistical evaluation of these datasets to identify the significant factors controlling risks posed. Our approach usefully establishes groundwater-quality baseline conditions of a potentially emergent issue for the study area. Such baselines are foundational to future trend discernment and contaminant natural attenuation verification critical to policies globally. Attribution of borehole contamination to pit-latrine loading should involve, as illustrated, the use of the range of contamination (chemical, microbiological) tracers available recognising none are ideal and several radial and capture-zone metrics that together may provide a weight of evidence. Elevated, albeit low-concentration, nitrate correlated with some radial metrics and was tentatively suggestive of emerging latrine influences. Longer term monitoring is, however, necessary to verify that the commonly observed latrine-borehole separation distances (29-58m), alongside statutory guidelines, do not constitute significant risk. Borehole contamination was limited and correlation with various environmental-site condition factors also limited. This was potentially ascribed to effectiveness of attenuation to date, monitoring of an emergent problem yet to manifest, or else contamination from other sources. High borehole usage

  7. Modelling assessment of End Pit Lakes meromictic potential

    International Nuclear Information System (INIS)

    2006-11-01

    The use of End Pit Lakes have been proposed as a remediation solution for oil sands reclamation and operational waters. This report modelled the main factors controlling the occurrence of stratification in Pit Lakes in order to establish design and management guidelines for the Cumulative Environmental Management Association's End Pit Lake Sub-group. The study focused on End Pit Lake size, depth, starting lake salinity concentrations, inflow rates and inflow salinity flux, and investigated their influence on density gradients. One-dimensional modelling and limited 2-D modelling simulations were conducted to examine meromictic potential for a large range of End Pit Lake configurations and conditions. Modelling results showed that fall is the governing season for determining meromixis. The expelling of salt from saline water upon ice formation and its effect on stratification potential and the effect of fresh water loading on stratification potential during spring melt events were not observed to be dominant factors governing meromictic potential for the scenarios examined in the study. Results suggested that shallow End Pit Lakes showed a high turn-over rate with seasonal heating and cooling cycles. Moderately deep End Pit Lakes demonstrated a meromictic potential that was inversely proportional to lake size and require higher starting salinities. With a 2 or 10 million m 3 /yr inflow rate and a 5 parts per thousand starting salinity, a 50 m deep End Pit Lake achieved meromixis at all 3 size ranges considered in the study. Results also showed that the rate of influent salinity decrease was the least important of the parameters influencing meromixis. It was observed that meromixis was a temporary condition in all of the End Pit Lake scenarios envisioned due to the lack of a constant, positive salt replenishment over the long term. It was concluded that further 3-D modelling is required to represent littoral areas as well as to account for extreme winter conditions. A

  8. Pitting of Incoloy 800 in presence of CuII

    International Nuclear Information System (INIS)

    Bianchi, G.L.; Alvarez, M.G.

    1993-01-01

    The pitting behaviour of Incoloy 800 in presence of Cu II ions, at 60 degrees C and 280 degrees C was studied by long term exposition of specimens in aqueous cupric chloride solutions. At 60 degrees C experiments were performed in aerated (7 ppm O 2 ) and deaerated solutions containing 500, 1000, 2000, 10000 and 20000 ppm CuCl 2 . At 280 degrees C experiments were performed in deaerated 20 ppm, 50 ppm and 100 ppm CuCl 2 solutions. During each experiment the open circuit potential of the alloy was measured as a function of time. After corrosion test the specimens were examined by Scanning Electron Microscopy for the presence of pits. In another set of experiments potentiodynamic anodic polarization curves were used to determine the pitting potential of Incoloy 800 in deaerated NaCl solutions at chloride concentrations and pH values corresponding to those possessed by solutions containing 20 ppm to 20000 ppm CuCl 2 . At 60 degrees C pitting was observed in those solutions where the CuCl 2 concentration is higher than 1000 ppm. At 280 degrees C pitting was found in the specimens exposed to those solutions where the CuCl 2 concentration was higher than 20 ppm. (author). 3 refs

  9. Herniation pits of the femur neck: incidence and radiologic findings

    International Nuclear Information System (INIS)

    Cho, Jae Hyun; Suh, Jin Suk; Lee, Hye Yeon

    1994-01-01

    In order to assess the incidence and radiologic findings of herniation pit of the femur neck in Korean. In 152 macerated femurs of 88 cadavers, and randomly selected 115 hips of 70 patients, the presence of herniation pit was determined by using fluoroscopy and radiography. It was then examined by CT for inspection of overlying surface and its opening was confirmed by inserting thin steal wire under the fluoroscopic guidance. Seventeen herniation pits in 15 macerated femurs of 13 cadavers were noted. (14.8%, 13/88). Two of 13 individuals showed bilaterality. All lesions were found only in males. Six herniation pit in 6 femurs of 6 patients (8.6%, 6/70) were also noted. All lesions were on anterosuperior aspect of femur neck. Plain radiographs of macerated femurs revealed well marginated and thin sclerosis in 15 lesions. Of all 23 lesions, CT showed cortical breakdown in 3, and overlying cortical thickening in 8. In 15 macerated femurs, roughed area of cortex was found in anterosuperior aspect of femur in all cases, and tiny openings(diameter less than 1 mm) related to cystic lesions were confirmed in 9 lesions. The incidence of herniation pits was 14.8% in 88 cadaver, and 8.6% in 70 patients. All were males

  10. Detailed investigation of current transients from metastable pitting events on stainless steel - the transition to stability

    International Nuclear Information System (INIS)

    Pistorius, P.C.; Burstein, G.T.

    1992-01-01

    Current transients which result from metastable pitting events (on Type 304 stainless steel in an acidic solution containing 1 M Cl - ) are presented. A criterion for the stable growth of open hemispherical pits is developed; the criterion states that the product of current density and pit depth must exceed a certain minimum value, to sustain rapid dissolution. Analysis of the transients from metastable pits shows that these pits fall short of this minimum, as do stable pits initially. The growth of these pits thus requires the presence of another barrier to diffusion, which is thought to be a remnant of the passive film; this forms a flawed cover over the pit mouth. When this cover ruptures under the influence of osmotic pressure, the pit repassivates. Pits growing at higher current densities approach the minimum requirement for stable growth more closely. A ''pitting potential'' results from the effect that metastable pits formed at more positive potentials grow at higher current densities, and are thus more likely to grow into stable pits. The effect of potential on the current density does not result from either activation control or ohmic control; rather, the pits grow under diffusion control. A change, with potential, of the type of pit site which can be activated, causes the potential dependence of the distribution of current densities in metastable pits. Although the distribution of current densities changes with potential, each metastable pit grows under diffusion control with a current density which is independent of the potential; this is confirmed by polarisation tests on growing metastable pits

  11. 200 West Ash Pit Demolition Site closure plan

    International Nuclear Information System (INIS)

    1992-11-01

    The Hanford Facility is owned by the US Government and operated by the US Department of Energy, Richland Field Office. Dangerous waste and mixed waste (containing both radioactive and dangerous components) are managed and produced on the Hanford Facility. Westinghouse Hanford Company is a major contractor to the US Department of Energy, Richland Field Office and serves as cooperator of the 200 West Ash Pit Demolition Site, the unit addressed in this closure plan. The 200 West Ash Pit Demolition Site Closure Plan consists of a Part A Permit Application (Revision 3) and a closure plan. An explanation of the Part A Permit Application revision is provided at the beginning of the Part A section. The closure plan consists of nine chapters and three appendices. This 200 West Ash Pit Demolition Site Closure Plan submittal contains information current as of October 15, 1992

  12. State Waste Discharge Permit application: 200-W Powerhouse Ash Pit

    Energy Technology Data Exchange (ETDEWEB)

    Atencio, B.P.

    1994-06-01

    As part of the Hanford Federal Facility Agreement and Consent Order negotiations; the US Department of Energy, Richland Operations Office, the US Environmental Protection Agency, and the Washington State Department of Ecology agreed that liquid effluent discharges to the ground on the Hanford Site which affect groundwater or have the potential to affect groundwater would be subject to permitting under the structure of Chapter 173-216 (or 173-218 where applicable) of the Washington Administrative Code, the State Waste Discharge Permit Program. This document constitutes the State Waste Discharge Permit application for the 200-W Powerhouse Ash Pit. The 200-W Powerhouse Ash Waste Water discharges to the 200-W Powerhouse Ash Pit via dedicated pipelines. The 200-W Powerhouse Ash Waste Water is the only discharge to the 200-W Powerhouse Ash Pit. The 200-W Powerhouse is a steam generation facility consisting of a coal-handling and preparation section and boilers.

  13. State Waste Discharge Permit application: 200-E Powerhouse Ash Pit

    Energy Technology Data Exchange (ETDEWEB)

    Atencio, B.P.

    1994-06-01

    As part of the Hanford Federal Facility Agreement and Consent Order negotiations, the US Department and Energy, Richland Operations Office, the US Environmental Protection Agency, and the Washington State Department of Ecology agreed that liquid effluent discharges to the ground on the Hanford Site which affect groundwater or have the potential to affect groundwater would be subject to permitting under the structure of Chapter 173-216 (or 173-218 where applicable) of the Washington Administrative Code, the State Waste Discharge Permit Program. This document constitutes the State Waste Discharge Permit application for the 200-E Powerhouse Ash Pit. The 200-E Powerhouse Ash Waste Water discharges to the 200-E Powerhouse Ash Pit via dedicated pipelines. The 200-E Ash Waste Water is the only discharge to the 200-E Powerhouse Ash Pit. The 200-E Powerhouse is a steam generation facility consisting of a coal-handling and preparation section and boilers.

  14. Optimal grade control sampling practice in open-pit mining

    DEFF Research Database (Denmark)

    Engström, Karin; Esbensen, Kim Harry

    2017-01-01

    Misclassification of ore grades results in lost revenues, and the need for representative sampling procedures in open pit mining is increasingly important in all mining industries. This study evaluated possible improvements in sampling representativity with the use of Reverse Circulation (RC) drill...... sampling compared to manual Blast Hole (BH) sampling in the Leveäniemi open pit mine, northern Sweden. The variographic experiment results showed that sampling variability was lower for RC than for BH sampling. However, the total costs for RC drill sampling are significantly exceeding current costs...... for manual BH sampling, which needs to be compensated for by other benefits to motivate introduction of RC drilling. The main conclusion is that manual BH sampling can be fit-for-purpose in the studied open pit mine. However, with so many mineral commodities and mining methods in use globally...

  15. Dewatering of planned Key Lake open pits in northern Saskatchewan

    International Nuclear Information System (INIS)

    Unland, W.; Holl, N.

    1980-01-01

    The engineering design and experience gained so far with a dewatering system for an open-pit uranium mine planned at Key Lake in Northern Saskatchewan are presented. An extensive unconfined overburden aquifer is hydraulically connected with the underlying Athabasca Formation and basement rocks, both of relatively low hydraulic conductivity. The overburden aquifer is embedded in a bedrock trough, with the deepest depression between the planned pits. Hydrogeological data were used in a numerical dewatering model simulating groundwater flow at different stages of the pit development. Based on the model results, the enginering design had to provide for different pumping rates, varying between 1.0 and 0.21 m 3 /sec. This problem was solved by using a double line pressure system. The design concept for the complete peripheral discharge system and the well design used for 26 dewatering wells are discussed. (auth)

  16. Congenital upper lip pit: A rare case report

    Directory of Open Access Journals (Sweden)

    Leena James

    2015-01-01

    Full Text Available One of the rarest developmental malformations of the lip is congenital lip pits. They are usually seen as bilateral depressions in the vermilion zone of the lip and occur on the paramedian portion of the vermilion border of the lip. They are extremely rare in the upper lip. Lip pits are due to the failure of complete union of embryonic lateral sulci of the lip/notching of lip at an early stage of development with fixation of tissues of the base of the notch. Lip pits have also been associated with a variety of other congenital disorders and other malformations. The clinical and pathologic picture and the therapeutic aspects of this condition are discussed in this paper.

  17. Fukushima Nuclear Accident Recorded in Tibetan Plateau Snow Pits

    Science.gov (United States)

    Wang, Ninglian; Wu, Xiaobo; Kehrwald, Natalie; Li, Zhen; Li, Quanlian; Jiang, Xi; Pu, Jianchen

    2015-01-01

    The β radioactivity of snow-pit samples collected in the spring of 2011 on four Tibetan Plateau glaciers demonstrate a remarkable peak in each snow pit profile, with peaks about ten to tens of times higher than background levels. The timing of these peaks suggests that the high radioactivity resulted from the Fukushima nuclear accident that occurred on March 11, 2011 in eastern Japan. Fallout monitoring studies demonstrate that this radioactive material was transported by the westerlies across the middle latitudes of the Northern Hemisphere. The depth of the peak β radioactivity in each snow pit compared with observational precipitation records, suggests that the radioactive fallout reached the Tibetan Plateau and was deposited on glacier surfaces in late March 2011, or approximately 20 days after the nuclear accident. The radioactive fallout existed in the atmosphere over the Tibetan Plateau for about one month. PMID:25658094

  18. The Influence of Radiation on Pit Solution Chemistry as it Pertains to the Transition from Metastable to Stable Pitting in Steels

    International Nuclear Information System (INIS)

    Galuszka-Muga, Barbara; Muga, Luis M.

    2006-01-01

    Previous work relevant to current efforts is summarized. A description of an improved version of a new electrochemical probe, the ArtPit, is given. The distinct feature of the probe for investigating metastable pitting of carbon steels is specified and compared to other approaches. The electrochemical response of the ArtPit under the gamma irradiation and elevated temperature conditions that occur at high level waste (HLW) storage tanks is presented. In particular, the Tafel slope determinations and chemical analyses of the ArtPit confined volume electrolyte are described. Based on results a possible approach for reducing the corrosion rate of HLW tank walls is suggested. Additional statistical analysis of the occurrence of short duration (passivated pits) and long term (stable pitting) electrochemical pulses (current surges) during exposure confirm that radiation enhances the occurrence of both more and smaller sized pits due to increased likelihood of repassivation

  19. Relationship between foveal cone specialization and pit morphology in albinism.

    Science.gov (United States)

    Wilk, Melissa A; McAllister, John T; Cooper, Robert F; Dubis, Adam M; Patitucci, Teresa N; Summerfelt, Phyllis; Anderson, Jennifer L; Stepien, Kimberly E; Costakos, Deborah M; Connor, Thomas B; Wirostko, William J; Chiang, Pei-Wen; Dubra, Alfredo; Curcio, Christine A; Brilliant, Murray H; Summers, C Gail; Carroll, Joseph

    2014-05-20

    Albinism is associated with disrupted foveal development, though intersubject variability is becoming appreciated. We sought to quantify this variability, and examine the relationship between foveal cone specialization and pit morphology in patients with a clinical diagnosis of albinism. We recruited 32 subjects with a clinical diagnosis of albinism. DNA was obtained from 25 subjects, and known albinism genes were analyzed for mutations. Relative inner and outer segment (IS and OS) lengthening (fovea-to-perifovea ratio) was determined from manually segmented spectral domain-optical coherence tomography (SD-OCT) B-scans. Foveal pit morphology was quantified for eight subjects from macular SD-OCT volumes. Ten subjects underwent imaging with adaptive optics scanning light ophthalmoscopy (AOSLO), and cone density was measured. We found mutations in 22 of 25 subjects, including five novel mutations. All subjects lacked complete excavation of inner retinal layers at the fovea, though four subjects had foveal pits with normal diameter and/or volume. Peak cone density and OS lengthening were variable and overlapped with that observed in normal controls. A fifth hyper-reflective band was observed in the outer retina on SD-OCT in the majority of the subjects with albinism. Foveal cone specialization and pit morphology vary greatly in albinism. Normal cone packing was observed in the absence of a foveal pit, suggesting a pit is not required for packing to occur. The degree to which retinal anatomy correlates with genotype or visual function remains unclear, and future examination of larger patient groups will provide important insight on this issue. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

  20. Structural evaluation of W-211 flexible receiver platforms and tank pit walls

    International Nuclear Information System (INIS)

    Shrivastava, H.P.

    1997-01-01

    This document is a structural analysis of the Flexible Receiver Platforms and the tank-pit wall during removal of equipment and during a accidental drop of that equipment. The platform and the pit walls must withstand a accidental drop of a mixer and transfer pumps in specific pits in tanks 102-AP and 104-AP. A mixer pump will be removed from riser 11 in pit 2A on tank 241-AP-102. A transfer pump will be removed from riser 13 in pit 2D on tank 241-AP-102 and another transfer pump will be removed from riser 3A in pit 4A on tank 241-AP-104

  1. DEFINICIÓN DE PIT FINAL CAPACITADO BAJO INCERTIDUMBRE

    OpenAIRE

    PEIRANO OPAZO, FERNANDO ANDRÉS

    2011-01-01

    El objetivo principal de este trabajo de tesis es desarrollar una metodología y una herramienta que permitan definir un pit final incorporando las restricciones de capacidad y las condiciones de incertidumbre asociadas al recurso geológico. El resultado metodológico consiste en un algoritmo de cálculo que incorpora heurísticas de definición de pit final como es la enunciada por Lerchs y Grossman (1964), en conjunto con heurísticas de secuenciamiento de bloques como son enunciadas por Gersh...

  2. Pitting and stress corrosion cracking of stainless steel

    Science.gov (United States)

    Saithala, Janardhan R.

    An investigation has been performed to determine the pitting resistance of stainless steels and stress corrosion cracking of super duplex stainless steels in water containing chloride ions from 25 - 170°C. The steels studied are 12% Cr, FV520B, FV566, 304L, Uranus65, 2205, Ferallium Alloy 255, and Zeron 100. All these commercial materials used in very significant industrial applications and suffer from pitting and stress corrosion failures. The design of a new experimental setup using an autoclave enabled potentiodynamic polarisation experiments and slow strain rate tests in dilute environments to be conducted at elevated temperatures. The corrosion potentials were controlled using a three electrode cell with computer controlled potentiostat.The experimental programme to determine pitting potentials was designed to simulate the service conditions experienced in most industrial plants and develop mathematical model equations to help a design engineer in material selection decision. Stress corrosion resistance of recently developed Zeron100 was evaluated in dilute environments to propose a mechanism in chloride solutions at high' temperatures useful for the nuclear and power generation industry. Results have shown the significance of the composition of alloying elements across a wide range of stainless steels and its influence on pitting. Nitrogen and molybdenum added to modern duplex stainless steels was found to be unstable at higher temperatures. The fractographic results obtained using the scanning electron microscope (SEM) has given insight in the initiation of pitting in modem duplex and super duplex stainless steels. A mathematical model has been proposed to predict pitting in stainless steels based on the effect of environmental factors (temperature, chloride concentration, and chemical composition). An attempt has been made to identify the mechanism of SCC in Zeron100 super duplex stainless steel.The proposed empirical models have shown good correlation

  3. Improving pitting corrosion resistance of aluminum by anodizing process

    International Nuclear Information System (INIS)

    John, P.; Khan, I.U.

    2013-01-01

    Summary: Anodizing of aluminum was studied in sulphuric/citric/boric acid electrolyte system to improve pitting corrosion resistance. Maximum oxide film thickness was obtained using 5% sulphuric acid, 3% citric acid and 0.5% boric acid electrolyte composition. The corrosion resistance of aluminum sample was determined to find the effectiveness of oxide coating by potentiodynamic polarization test. The surface morphology of aluminum samples was investigated using scanning electron microscope (SEM) before and after corrosion test. It was found that the coated aluminum sample obtained by anodizing in sulphuric/citric/boric acid electrolyte system exhibited better pitting corrosion resistance with no significant difference in surface morphology. (author)

  4. Interior drains for open pit disposal of uranium mill tailings

    International Nuclear Information System (INIS)

    Staub, W.P.

    1978-01-01

    A conceptualized interior drainage system is presented for reducing the environmental impact on natural groundwater by disposal of uranium mill tailings in the mined-out open pit. The evaporation/seepage ratio can be increased through the use of interior drains, long-term monitoring of groundwater quality can be eliminated, and the open pit will not require an extensive liner. Other advantages not related to groundwater are: control of fugitive dust and radon emanation during mill operations and timely reclamation after the impoundment is filled with tailings

  5. Microstructural evolution and pitting resistance of annealed lean duplex stainless steel UNS S32304

    International Nuclear Information System (INIS)

    Zhang Ziying; Han Dong; Jiang Yiming; Shi Chong; Li Jin

    2012-01-01

    Highlights: ► The relationship between pitting corrosion resistance and annealing temperature for UNS S32304 was systemically studied. ► The specimens annealed at 1080 °C for 1 h, quenched in water exhibit the best pitting corrosion resistance. ► The relationship between microstructural evolution and pitting resistance of annealed UNS S32304 was discussed in detail. ► The pitting corrosion resistance is consistent with pitting resistance equivalent number of weaker phase for UNS S32304 alloy. - Abstract: The effect of annealing temperature in the range from 1000 to 1200 °C on the pitting corrosion behavior of duplex stainless steel UNS S32304 was investigated by the potentiodynamic polarization and potentiostatic critical pitting temperature techniques. The microstructural evolution and pit morphologies were studied using a scanning electron microscopy with energy dispersive X-ray spectroscopy. The results demonstrated that the nucleation of metastable pits transformed from austenite phase to ferrite phase with the increasing annealing temperature. As the annealing temperature increased, the pitting corrosion resistance firstly increased and then decreased. The highest pitting corrosion resistance was obtained at 1080 °C with the highest critical pitting temperature value and pitting nucleation resistance. The results could be well explained by the microstructural evolution of ferrite and austenite phases induced by annealing treatment.

  6. Pitting Corrosion Topography Characteristics and Evolution Laws of LC4 Aluminum Alloy in Service Environment

    Directory of Open Access Journals (Sweden)

    LIU Zhiguo

    2017-08-01

    Full Text Available Aircraft aluminum alloy is easy to initiate pitting corrosion in the service environment, the pitting corrosion topography characteristics could directly affect the fatigue mechanical property of structure material. In order to obtain the pitting corrosion topography characteristics of LC4 aluminum alloy in the service environment, the accelerated corrosion test was carried out along the accelerated corrosion test environment spectrum which imitated the service environment spectrum, and the corrosion topography characteristic parameters of corrosion pit depth H,corrosion pit surface length L and corrosion pit surface width W were defined respectively. During the corrosion test process,the three parameters of typical corrosion pit were successively measured in different equivalent corrosion years for obtaining the corrosion pit damage size data, then the data were analysed through the statistics method and fractal theory. Further more in order to gain the pit topography characteristics in the same equivalent corrosion year and the topography evolution laws during different equivalent corrosion years were gained. The analysis results indicate that LC4 aluminum alloy corrosion pit topography characteristics in the service environment include the following:firstly, the pit topography characteristic parameters conform to the lognormal distributions in the same equivalent corrosion years; secondly,the pit topography characteristic parameters gradually reflect the fractal feature in accordance with the equivalent corrosion year increment, and the pits tend to be shallow, long and moderate wide topography character.

  7. Optimization Of Blasting Design Parameters On Open Pit Bench A Case Study Of Nchanga Open Pits

    Directory of Open Access Journals (Sweden)

    Victor Mwango Bowa

    2015-08-01

    Full Text Available Abstract In hard rock mining blasting is the most productive excavation technique applied to fragment insitu rock to the required size for efficient loading and crushing. In order to blast the insitu rock to the desired fragment size blast design parameter such as bench height hole diameter spacing burden hole length bottom charge specific charge and rock factor are considered. The research was carried out as a practical method on Nchanga Open Pits NOP ore Bench to optimize the blasting design parameters that can yield the required fragmentation size thereby reducing the shovel loading times and maximizing efficiency of the subsequent mining unit operations such as hauling and crushing. Fragmentation characteristics such as the mean fragment size were measured by means of a digital measuring tape and predicated using the Kuznetsov equation and rock factor value of ore bench was calculated using Lilly 1986 equations by means of rock characteristics. Traditional blasting design parameters were acquired for NOP and modified using Langerfors and Sharma P.A approaches. Several blast operations were conducted using both traditional and modified blasting design parameters on the same ore bench with the same geological conditions. Loading times of the shovel and fragment sizes were obtained after the blasts from ore bench where both the traditional and modified blasting design parameters were applied. Results show that mean fragment size and loading times were reduced from 51cm and 12minutes to 22cm and 3minutes where traditional and modified blasting design parameters were applied respectively.

  8. Railroad Rails Containing Electrode-Induced Pitting from Pressure Electric Welding

    Science.gov (United States)

    2018-04-18

    This paper describes the forensic evaluations of three railroad rails containing electrode-induced pitting. These evaluations include: magnetic particle inspection to nondestructively detect cracks emanating from the pitting; fractography to study th...

  9. Situation and development of uranium open-pit mining techniques in China

    International Nuclear Information System (INIS)

    Li Kaiwen.

    1986-01-01

    The situation of uranium open-pit mining techniques in China is described. The main experiences in production and management are introduced. Meanwhile the suggestions about the further development of uranium open-pit mining techniques are also proposed

  10. Preliminary quantification of a shape model for etch-pits formed during natural weathering of olivine

    International Nuclear Information System (INIS)

    Nowicki, M. Anna; Velbel, Michael A.

    2011-01-01

    Many etch-pits on olivine grains occur as a pair of cone-shaped pits sharing a base, which consequently appear as diamond-shaped etch-pits in cross-section. Quantitative image analysis of back-scattered electron images establishes empirical dimensions of olivine etch-pits in naturally weathered samples from Hawaii and North Carolina. Images of naturally etched olivine were acquired from polished thin-sections by scanning electron microscopy. An average cone-radius-to-height ratio (r:h) of 1.78 was determined for diamond-shaped cross-sections of etch-pits occurring in naturally weathered olivine grains, largely consistent with previous qualitative results. Olivine etch-pit shape as represented by r:h varies from slightly more than half the average value to slightly more than twice the average. Etch-pit shape does not appear to vary systematically with etch-pit size.

  11. Towards a rapid assessment protocol for identifying pit lakes worthy of restoration.

    Science.gov (United States)

    de Lange, W J; Genthe, B; Hill, L; Oberholster, P J

    2018-01-15

    Before the introduction of reclamation legislation in South Africa, final cut lakes in mining areas were left without any restoration while the final excavation was not back filled. Characteristics of these lacustrine water bodies vary considerably, but they are often linear in shape, large (1-30 ha), deep (2-30 m) and have poorly developed littoral zones. With water tables often near the surface; a variety of vascular hydrophytes can colonize these bodies, thus establishing emerging wetland type ecosystems. These, man-made aquatic structures that are (unintentionally) created potentially offers some realistic and inexpensive mitigation options for some of the negative impacts associated with mining, i.e. these water bodies can become useful by yielding potentially valuable services. However, no method currently exists to compare and rank these water bodies according ecological integrity and the expected monetary value to be derived from them in order to select sites for restoration. To answer this need, we applied an index to determine the ability of these water bodies to provide useful services in their current state. The index was then used to derive estimates of the monetary value of potential services in order to allow comparison with the cost of restoring the water body in question or to compare with other pit lakes. We present a South African case study to illustrate the method. As far as could be established, this is the first attempt towards creating a rapid assessment tool as standardised way of comparing pit lakes that allows for the ranking and identification of those pit lakes worthy of restoration. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Effect of Trimeresurus albolabris (green pit viper) venom on mean ...

    African Journals Online (AJOL)

    An in vitro study was conducted by mixing small amounts of green pit viper venom with blood and observing changes. At a concentration of 10 mg crude venom, red blood cells (RBC) osmotic fragility slightly increased. RBC morphology changed to spherical shape which was compatible with what was observed in scanning ...

  13. Atomic force microscopy of torus-bearing pit membranes

    Science.gov (United States)

    Roland R. Dute; Thomas Elder

    2011-01-01

    Atomic force microscopy was used to compare the structures of dried, torus-bearing pit membranes from four woody species, three angiosperms and one gymnosperm. Tori of Osmanthus armatus are bipartite consisting of a pustular zone overlying parallel sets of microfibrils that form a peripheral corona. Microfibrils of the corona form radial spokes as they traverse the...

  14. Heavy Duty Tireman. Open Pit Mining Job Training Series.

    Science.gov (United States)

    McColman, Don

    This training outline for heavy duty tiremen, one in a series of eight outlines, is designed primarily for company training foremen or supervisors and for trainers to use as an industry-wide guideline for heavy equipment operator training in open pit mining in British Columbia. Intended as a guide for preparation of lesson plans both for classroom…

  15. Front End Loader Operator. Open Pit Mining Job Training Series.

    Science.gov (United States)

    Savilow, Bill

    This training outline for front end loader operators, one in a series of eight outlines, is designed primarily for company training foremen or supervisors and for trainers to use as an industry-wide guideline for heavy equipment operator training in open pit mining in British Columbia. Intended as a guide for preparation of lesson plans both for…

  16. Mission-Critical Mobile Broadband Communications in Open Pit Mines

    DEFF Research Database (Denmark)

    Uzeda Garcia, Luis Guilherme; Portela Lopes de Almeida, Erika; Barbosa, Viviane S. B.

    2016-01-01

    that need to be met by the wireless network. This article introduces fundamental concepts behind open-pit mining and discusses why this ever changing environment coupled with strict industrial reliability requirements pose unique challenges to traditional broadband network planning and optimization...

  17. Track Dozer Operator. Open Pit Mining Job Training Series.

    Science.gov (United States)

    British Columbia Dept. of Education, Victoria.

    This training outline for track dozer operators, one in a series of eight outlines, is designed primarily for company training foremen or supervisors and for trainers to use as an industry-wide guideline for heavy equipment operator training in open pit mining in British Columbia. Intended as a guide for preparation of lesson plans both for…

  18. Rotary Drill Operator. Open Pit Mining Job Training Series.

    Science.gov (United States)

    Savilow, Bill

    This training outline for rotary drill operators, one in a series of eight outlines, is designed primarily for company training foremen or supervisors and for trainers to use as an industry-wide guideline for heavy equipment operator training in open pit mining in British Columbia. Intended as a guide for preparation of lesson plans both for…

  19. Haulage Truck Operator. Open Pit Mining Job Training Series.

    Science.gov (United States)

    British Columbia Dept. of Education, Victoria.

    This training outline for haulage truck operators, one in a series of eight outlines, is designed primarily for company training foremen or supervisors and for trainers to use as an industry-wide guideline for heavy equipment operator training in open pit mining in British Columbia. Intended as a guide for preparation of lesson plans both for…

  20. Grader Operator. Open Pit Mining Job Training Series.

    Science.gov (United States)

    Savilow, Bill

    This training outline for grader operators, one in a series of eight outlines, is designed primarily for company training foremen or supervisors and for trainers to use as an industry-wide guideline for heavy equipment operator training in open pit mining in British Columbia. Intended as a guide for preparation of lesson plans both for classroom…

  1. Rubber Tire Dozer Operator. Open Pit Mining Job Training Series.

    Science.gov (United States)

    British Columbia Dept. of Education, Victoria.

    This training outline for rubber tire dozer operators, one in a series of eight outlines, is designed primarily for company training foremen or supervisors and for trainers to use as an industry-wide guideline for heavy equipment operator training in open pit mining in British Columbia. Intended as a guide for preparation of lesson plans both for…

  2. Bitter pit in apples: pre- and postharvest factors: A review

    International Nuclear Information System (INIS)

    Jemrić, T.; Fruk, I.; Fruk, M.; Radman, S.; Sinkovič, L.; Fruk, G.

    2016-01-01

    Bitter pit is a physiological disorder that significantly reduces the quality of apples. Although it has been detected since the beginning of the last century, still there is little known about the mechanism of its occurrence. According to numerous studies, bitter pit is formed as a result of calcium deficiency in the fruit. Some authors cite the high concentration of gibberellins, later in the production season, most probably caused by excessive activity of the roots, as the chief causative factor. Beside Ca, there are several factors that can also contribute to its development, like imbalance among some mineral elements (N, P, K and Mg), cultivar, rootstock, the ratio of vegetative and generative growth, post-harvest treatments and the storage methods. There are some prediction models available that can estimate the risk of bitter pit in apples, but even those are not always reliable. The aim of this review was to encompass the pre and postharvest factors which cause bitter pit and point out the directions for solving this problem.

  3. Shovel Operator. Open Pit Mining Job Training Series.

    Science.gov (United States)

    Hartley, Larry

    This training outline for shovel operators, one in a series of eight outlines, is designed primarily for company training foremen or supervisors and for trainers to use as an industry-wide guideline for heavy equipment operator training in open pit mining in British Columbia. Intended as a guide for preparation of lesson plans both for classroom…

  4. Bitter pit in apples: pre- and postharvest factors: A review

    Energy Technology Data Exchange (ETDEWEB)

    Jemrić, T.; Fruk, I.; Fruk, M.; Radman, S.; Sinkovič, L.; Fruk, G.

    2016-07-01

    Bitter pit is a physiological disorder that significantly reduces the quality of apples. Although it has been detected since the beginning of the last century, still there is little known about the mechanism of its occurrence. According to numerous studies, bitter pit is formed as a result of calcium deficiency in the fruit. Some authors cite the high concentration of gibberellins, later in the production season, most probably caused by excessive activity of the roots, as the chief causative factor. Beside Ca, there are several factors that can also contribute to its development, like imbalance among some mineral elements (N, P, K and Mg), cultivar, rootstock, the ratio of vegetative and generative growth, post-harvest treatments and the storage methods. There are some prediction models available that can estimate the risk of bitter pit in apples, but even those are not always reliable. The aim of this review was to encompass the pre and postharvest factors which cause bitter pit and point out the directions for solving this problem.

  5. Characterization of pavement distress from test pit observation

    CSIR Research Space (South Africa)

    Mgangira, Martin B

    2009-08-01

    Full Text Available the profiling exercise of an investigation into the causes of the premature failure of a pavement. The field investigation entailed a detailed inspection and recording of the profile exposed in test pits, with particular attention being paid to areas with cracks...

  6. THE IMPACT OF PHOSPHATE ON COPPER PITTING CORROSION

    Science.gov (United States)

    Pinhole leaks caused by extensive localized or pitting corrosion of copper pipes is a problem for many homeowners. Pinhole water leaks may result in water damage, mold growth, and costly repairs. A large water system in Florida has been addressing a widespread pinhole leak proble...

  7. COPPER PITTING CORROSION AND PINHOLE LEAKS: A CASE STUDY

    Science.gov (United States)

    Localized corrosion, or "pitting", of copper drinking water pipe continues is a problem for many water utilities and their customers. Extreme attack leads to pinhole leaks that can potentially lead to water damage, mold growth, and costly repairs for the homeowners, as well as th...

  8. Plantar pitted keratolysis: a study from non-risk groups

    Directory of Open Access Journals (Sweden)

    Asli Feride Kaptanoglu

    2012-02-01

    Full Text Available Pitted keratolysis is an acquired, superficial bacterial infection of the skin which is characterized by typical malodor and pits in the hyperkeratotic areas of the soles. It is more common in barefooted people in tropical areas, or those who have to wear occlusive shoes, such as soldiers, sailors and athletes. In this study, we evaluated 41 patients who had been diagnosed with plantar pitted keratolysis. The patients were of high socioeconomic status, were office-workers, and most had a university degree. Malodor and plantar hyperhydrosis were the most frequently reported symptoms. The weight-bearing metatarsal parts of the feet were those most affected. Almost half the women in the study gave a history of regular pedicure and foot care in a spa salon. Mean treatment duration was 19 days. All patients were informed about the etiology of the disease, predisposing factors and preventive methods. Recurrences were observed in only 17% of patients during the one year follow-up period. This study emphasizes that even malodorous feet among non-risk city dwellers may be a sign of plantar pitted keratolysis. A study of the real incidence of the disease in a large population-based series is needed.

  9. Laboratory protocols for testing the efficacy of commercial pit latrine ...

    African Journals Online (AJOL)

    additive products. Protocols were developed and tested on a range of different commercial products sold for their ability to control the rate of accumulation of pit latrine contents. The effect of commercial additives on mass loss from VIP sludge in. 300 g honey jars was compared to mass loss from similar units subjected to no ...

  10. The kinetics of pitting corrosion of carbon steel

    International Nuclear Information System (INIS)

    Marsh, G.P.; Taylor, K.J.; Sooi, Z.

    1988-02-01

    The development of an improved statistical method for analysing pit growth data to take account of the difference in area of laboratory specimens and full sized high level nuclear waste containers is described. Statistical analysis of data from pit growth experiments with large area (460 cm 2 ) plates of BS 4360 steel have indicated that the depth distributions correlate most closely with a limited distribution function. This correlation implies that previous statistical analyses to estimate the maximum pit depths in full size containers, which were made using unlimited distribution functions, will be pessimistic. An evaluation of the maximum feasible pitting period based on estimating the period during which the oxygen diffusion flux is sufficient to stabilise a passive film on carbon steel containers has indicated that this is of the order of 125 years rather than the full 1000 year container life. The estimate is sensitive to the value of the leakage current assumed to flow through the passive film, and therefore work is planned to measure this accurately in relevant granitic environments. (author)

  11. A critical analysis of physiochemical properties influencing pit latrine ...

    African Journals Online (AJOL)

    User

    African Journal of Environmental Science and ... Department of Agricultural and Bio-systems Engineering, Makerere University, ... Key words: Pit latrine, faecal sludge management, developing countries, ..... PCA was the most innovative and novel aspect of the ..... A project report submitted to Loughborough University of.

  12. Demonstration of In-Situ Stabilization of Buried Waste at Pit G-11 at the Brookhaven National laboratory Glass Pits Disposal Site

    International Nuclear Information System (INIS)

    Dwyer, B.P.; Gilbert, J.; Heiser, J.

    1999-01-01

    In 1989 BNL was added to the EPAs National Priorities List. The site is divided into seven operable units (OU). OU-I includes the former landfill area. The field task site is noted as the AOC 2C Glass Holes location. Beginning in the 1960s and continuing into the 1980s, BNL disposed of laboratory waste (glassware, chemicals and animal carcasses) in numerous shallow pits. The drivers for remediating the pits are; historical records that indicate hazardous materials may have been disposed of in the pits; ground water contamination down gradient of the pits; a test excavation of one of the glass holes that unearthed laboratory glass bottles with unidentified liquids still contained; and the fact that BNL rests atop an EPA designated sole-source aquifer. The specific site chosen for this demonstration was pit G-11. The requirements that lead to choosing this pit were; a well characterized pit and a relatively isolated pit where our construction operations would not impact on adjacent pits. The glass holes area, including pit G-11, was comprehensively surveyed using a suite of geophysical techniques (e.g., EM-31, EM-61, GPR). Prior to stabilizing the waste form a subsurface barrier was constructed to contain the entire waste pit. The pit contents were then stabilized using a cement grout applied via jet grouting. The stabilization was performed to make removal of the waste from the pit easier and safer in terms of worker exposure. The grouting process would mix and masticate the waste and grout and form a single monolithic waste form. This large monolith would then be subdivided into smaller 4 foot by 4 foot by 10-12 foot block using a demolition grout. The smaller blocks would then be easily removed from the site and disposed of in a CERCLA waste site

  13. Rationale and concept for a lunar pit reconnaissance probe

    Science.gov (United States)

    Dorrington, G. E.

    2018-04-01

    Speculation on near-term scientific reasons for the exploration of lunar pits is offered alongside comments on possible longer-term human exploitation. It is proposed that in order to determine whether or not one or more of the pits offer access the large subsurface voids e.g. a non-collapsed lava tube, a preliminary reconnaissance mission solely focused on obtaining lateral images (and/or LiDAR maps) is needed. Possible concept options for such a preliminary reconnaissance mission are discussed. It is suggested that one of the best possible strategies is to employ a micro-sized probe (∼0.3m) that would hop from a nearby main landing spacecraft to the selected pit. After the surface position of the main lander is determined accurately, the probe would perform a ballistic hop, or hover-traverse, a distance of ∼3 km over the lunar surface using existing propulsive and guidance technology capability. Once hovering above the pit, the probe or a separate tethered imaging unit would then be lowered into the pit to acquire the necessary subsurface void topology data. This data would then be transmitted back to Earth, directly, via the lander, or via a store-and-forward orbiting relay. Preliminary estimates indicate that a probe of ∼14 kg (dry mass) is viable using a conventional hydrazine monopropellant system with a propellant mass fraction of less than ∼0.2 (20%) including margins, suggesting a piggyback architecture would be feasible.

  14. Standardized emissions inventory methodology for open-pit mining areas.

    Science.gov (United States)

    Huertas, Jose I; Camacho, Dumar A; Huertas, Maria E

    2011-08-01

    There is still interest in a unified methodology to quantify the mass of particulate material emitted into the atmosphere by activities inherent to open-pit mining. For the case of total suspended particles (TSP), the current practice is to estimate such emissions by developing inventories based on the emission factors recommended by the USEPA for this purpose. However, there are disputes over the specific emission factors that must be used for each activity and the applicability of such factors to cases quite different to the ones under which they were obtained. There is also a need for particulate matter with an aerodynamic diameter less than 10 μm (PM(10)) emission inventories and for metrics to evaluate the emission control programs implemented by open-pit mines. To address these needs, work was carried out to establish a standardized TSP and PM(10) emission inventory methodology for open-pit mining areas. The proposed methodology was applied to seven of the eight mining companies operating in the northern part of Colombia, home to the one of the world's largest open-pit coal mining operations (∼70 Mt/year). The results obtained show that transport on unpaved roads is the mining activity that generates most of the emissions and that the total emissions may be reduced up to 72% by spraying water on the unpaved roads. Performance metrics were defined for the emission control programs implemented by mining companies. It was found that coal open-pit mines are emitting 0.726 and 0.180 kg of TSP and PM(10), respectively, per ton of coal produced. It was also found that these mines are using on average 1.148 m(2) of land per ton of coal produced per year.

  15. Evaluation of water chemistry on the pitting susceptibility of aluminum

    International Nuclear Information System (INIS)

    Chandler, G.T.; Sindelar, R.L.; Lam, P.S.

    1997-01-01

    Aluminum-clad spent nuclear fuels are being stored in water in the Receiving Basin for Off-site Fuels (RBOF) and the reactor disassembly (cooling) basins at the Savannah River Site (SRS). Experience shows that fuels stored in water are subject to rapid pitting corrosion if the water quality is poor. Upgrade projects and actions, including those to improve water quality, were recently undertaken to upgrade the disassembly basins for extended storage. A technical strategy was developed for continued basin storage of aluminum-clad fuel assemblies. The strategy includes development and implementation of basin technical standards for water quality to minimize attack due to pitting corrosion over a desired storage period. In the absence of localized corrosion, only slow, general corrosion of the cladding would be expected. A laboratory corrosion program is being performed to provide the bases for technical standards by identifying the region of aggressive water qualities where existing oxide films would tend to break down and pits would initiate and remain active. Initial results from corrosion potential and cyclic polarization testing of aluminum alloys in various water chemistries have shown that low conductivity water (< 50 μS/cm) should not be aggressive to cause self-pitting corrosion. Initial results from tests of 8001 and 5052 aluminum and aluminium-10% uranium alloy indicate that a strong galvanic couple should not exist between the aluminum cladding materials and the aluminum-uranium fuel. Additional laboratory testing will include immersion testing to allow characterization of the growth rate of active pits to benchmark a kinetic model. This model will form the basis for a water quality technical standard and enable prediction of the life of aluminum-clad spent nuclear fuels in basin storage

  16. Study of pitting corrosion in line-pipe steel under the influence of remanent magnetization

    Energy Technology Data Exchange (ETDEWEB)

    Espina-Hernandez, J H; Caleyo, F; Hallen, J M [Instituto Politecnico Nacional (IPN), Zacatenco (Mexico)

    2009-07-01

    The influence of remanent magnetization on pitting corrosion in line-pipe steels is studied. Pitting corrosion experiments have been carried out on samples of an API 5L grade 52 steel under a magnetization level of the same order of magnitude of the remanent magnetization in the pipeline wall after in-line inspection based on magnetic flux leakage. The samples were magnetized using rings of the same grade as the investigated steel. Immediately after magnetization, the investigated samples were subjected to pitting by immersing them in a solution containing dissolved Cl{sup -} and SO{sup 2-}{sub 4} and ions. The pitting experiments were conducted during a seven days period. The pit depth distribution and the maximum pit depth in each sample were recorded and used to conduct extreme value analyses of the pitting process in magnetized and non-magnetized control samples. The statistical assessment of the pitting corrosion data collected during this study shows that the magnetic field reduces the average depth of the pit population and also the extreme pit depth values that can be predicted from the maximum values observed in the magnetized samples in comparison with to the non-magnetized control samples. Scanning electron microscopy observations show that the magnetic field alters the pit morphology by increasing the pit mouth opening. (author)

  17. 78 FR 33894 - Proposed Information Collection (Open Burn Pit Registry Airborne Hazard Self-Assessment...

    Science.gov (United States)

    2013-06-05

    ... chemicals and fumes caused by open burn pits. DATES: Written comments and recommendations on the proposed... to ``OMB Control No. 2900-NEW, Open Burn Pit Registry Airborne Hazard Self-Assessment Questionnaire.... Title: Open Burn Pit Registry Airborne Hazard Self-Assessment Questionnaire, VA Form 10-10066. OMB...

  18. ON THE PROPAGATION OF OPEN AND COVERED PIT IN 316L STAINLESS STEEL

    International Nuclear Information System (INIS)

    Heurtault, Stéphane; Robin, Raphaël; Rouillard, Fabien; Vivier, Vincent

    2016-01-01

    Highlights: • The propagation of a single pit was investigated with a flow micro-device. • Both in depth and radial pit propagation were characterized. • The formation of a salt film in the pit was discussed. - Abstract: Pitting corrosion on stainless steel has been widely studied during the last decades, but since it is a stochastic process, it remains difficult to analyze experimentally such a phenomenon. In this work, reproducible single pits were performed on 316L steel by using an experimental setup based on the use of a glass microcapillary to locally supply chloride ions on the steel surface in order to characterize the pit propagation. This original approach allowed obtaining new results about pit propagation. Indeed, it was possible to control the presence of a metallic cap covering the pit by adjusting the experimental parameters (potential – chloride to sulfate ratio – temperature). The presence of this cover was shown to be an important issue concerning the propagation mechanism. It was also possible to study the evolution of both the pit depth and the pit diameter as a function of various parameters. Then, based on the simulation of the current densities at the pit bottom and at the pit aperture, a special attention has been paid for the investigation of the local propagation mechanism.

  19. Creating Nanoscale Pits on Solid Surfaces in Aqueous Environment with Scanning Tunnelling Microscopy

    DEFF Research Database (Denmark)

    Chi, Qijin; Zhang, Jingdong; Friis, Esben P.

    2000-01-01

    of the pits can be controlled well in aqueous environments, and the operations are simple. Parameters affecting the pit formation and size have been systematically characterized to show that pit formation is dominated by bias voltage. A mechanism is proposed based on local surface reconstruction induced...

  20. Tale of two pit lakes: initial results of a three-year study of the Main Zone and Waterline pit lakes near Houston, British Columbia, Canada

    Science.gov (United States)

    Crusius, John; Pieters, R.; Leung, A.; Whittle, P.; Pedersen, T.; Lawrence, G.; McNee, J.J.

    2003-01-01

    Pit lakes are becoming increasingly common in North America as well as in the rest of the world. They are created as openpit mines fill passively with ground water and surface inflows on cessation of mining activity. In many instances, the water quality in these pit lakes does not meet regulatory requirements due to a number of influences. The most important are the oxidation of sulfide minerals and the associated release of acid and metals and the flushing of soluble metals during pit filling. Examples of pit lakes with severe water-quality problems include the Berkeley Pit lake (Butte, MT) and the Liberty Pit lake (Nevada), whose waters are characterized by a pH near 3 and Cu concentrations as high as ~150 mg/L (Miller et al., 1996; Davis and Eary, 1997). The importance of the problem can be seen in the fact that some of these sites in the United States are Superfund sites.

  1. Comparative study of resin sealant and resin modified glass ionomer as pit and fissure sealant

    Directory of Open Access Journals (Sweden)

    Shirin Malek

    2017-02-01

    Full Text Available The purpose of the present study was to compare the marginal integrity of resin modified glass ionomer cement with that of resin sealant, in vitro. Forty artificial pit and fissure cavities were prepared in occlusal surface of extracted premolar teeth by using ¼ round carbide bur. Cavities were condensed with artificial organic debris followed by cleaning with prophylaxis pumice brush and paste and then separated into two treatment groups. In Group A, 15 fissure cavities were sealed by resin sealant and in Group B, 15 fissure cavities were sealed by resin modified glass ionomer sealant. These specimens were subjected to thermo-cycling followed by dye penetration test. The remaining 5 cavities from each group were analyzed for debris score by the SEM. The results of the microleakage test showed that the efficacy of preventing microleakage of samples sealed by resin modified glass ionomer sealant was higher than the samples sealed by resin sealant. However, no significant differences were found. It can be concluded that use of resin modified glass ionomer sealant is a good alternative for sealing pits and fissures.

  2. 'Integration'

    DEFF Research Database (Denmark)

    Olwig, Karen Fog

    2011-01-01

    , while the countries have adopted disparate policies and ideologies, differences in the actual treatment and attitudes towards immigrants and refugees in everyday life are less clear, due to parallel integration programmes based on strong similarities in the welfare systems and in cultural notions...... of equality in the three societies. Finally, it shows that family relations play a central role in immigrants’ and refugees’ establishment of a new life in the receiving societies, even though the welfare society takes on many of the social and economic functions of the family....

  3. Impacts of swine manure pits on groundwater quality

    International Nuclear Information System (INIS)

    Krapac, I.G.; Dey, W.S.; Roy, W.R.; Smyth, C.A.; Storment, E.; Sargent, S.L.; Steele, J.D.

    2002-01-01

    New information is presented on impacts on groundwater by manure storage in deep ground pits. - Manure deep-pits are commonly used to store manure at confined animal feeding operations. However, previous to this study little information had been collected on the impacts of deep-pits on groundwater quality to provide science-based guidance in formulating regulations and waste management strategies that address risks to human health and the environment. Groundwater quality has been monitored since January 1999 at two hog finishing facilities in Illinois that use deep-pit systems for manure storage. Groundwater samples were collected on a monthly basis and analyzed for inorganic and bacteriological constituent concentrations. The two sites are located in areas with geologic environments representing different vulnerabilities for local groundwater contamination. One site is underlain by more than 6 m of clayey silt, and 7-36 m of shale. Concentrations of chloride, ammonium, phosphate, and potassium indicated that local groundwater quality had not been significantly impacted by pit leakage from this facility. Nitrate concentrations were elevated near the pit, often exceeding the 10 mg N/l drinking water standard. Isotopic nitrate signatures suggested that the nitrate was likely derived from soil organic matter and fertilizer applied to adjacent crop fields. At the other site, sandstone is located 4.6-6.1 m below land surface. Chloride concentrations and δ 15 N and δ 18 O values of dissolved nitrate indicated that this facility may have limited and localized impacts on groundwater. Other constituents, including ammonia, potassium, phosphate, and sodium were generally at or less than background concentrations. Trace- and heavy-metal concentrations in groundwater samples collected from both facilities were at concentrations less than drinking water standards. The concentration of inorganic constituents in the groundwater would not likely impact human health. Fecal

  4. Impacts of swine manure pits on groundwater quality

    Energy Technology Data Exchange (ETDEWEB)

    Krapac, I.G.; Dey, W.S.; Roy, W.R.; Smyth, C.A.; Storment, E.; Sargent, S.L.; Steele, J.D

    2002-12-01

    New information is presented on impacts on groundwater by manure storage in deep ground pits. - Manure deep-pits are commonly used to store manure at confined animal feeding operations. However, previous to this study little information had been collected on the impacts of deep-pits on groundwater quality to provide science-based guidance in formulating regulations and waste management strategies that address risks to human health and the environment. Groundwater quality has been monitored since January 1999 at two hog finishing facilities in Illinois that use deep-pit systems for manure storage. Groundwater samples were collected on a monthly basis and analyzed for inorganic and bacteriological constituent concentrations. The two sites are located in areas with geologic environments representing different vulnerabilities for local groundwater contamination. One site is underlain by more than 6 m of clayey silt, and 7-36 m of shale. Concentrations of chloride, ammonium, phosphate, and potassium indicated that local groundwater quality had not been significantly impacted by pit leakage from this facility. Nitrate concentrations were elevated near the pit, often exceeding the 10 mg N/l drinking water standard. Isotopic nitrate signatures suggested that the nitrate was likely derived from soil organic matter and fertilizer applied to adjacent crop fields. At the other site, sandstone is located 4.6-6.1 m below land surface. Chloride concentrations and {delta}{sup 15}N and {delta}{sup 18}O values of dissolved nitrate indicated that this facility may have limited and localized impacts on groundwater. Other constituents, including ammonia, potassium, phosphate, and sodium were generally at or less than background concentrations. Trace- and heavy-metal concentrations in groundwater samples collected from both facilities were at concentrations less than drinking water standards. The concentration of inorganic constituents in the groundwater would not likely impact human

  5. Formation of primary pit connection during conchocelis phase of Porphyra yezoensis (Bangiophyceae, Rhodophyta)

    Science.gov (United States)

    Shual, Li; Jiang, Ming; Duan, Delin

    2006-09-01

    The formation of pit connection during conchocelis phase of Porphyra yezoensis Ueda was observed and examined with transmission electron microscope (TEM) and epifluorence microscope. It is indicated that the pit connection was formed in late stage of conchocelis phase and the early stages of conchosporangial cell development, and disappeared in bispore stage. The pit connection contained a thin membrane layer at outer pit plug. Stained with 4', 6'-diamidino-2-phenylidole dihydrochloride hydrate (DAPI), transferring of DNA or RNA between adjacent cells were observed in late stage of conchocelis development, it was deduced that pit connection might serve as a channel for signal transduction and genetic substance transportation in conchocelis phase.

  6. Assessment of the impacts of pit latrines on groundwater quality in rural areas: A case study from Marondera district, Zimbabwe

    Science.gov (United States)

    Dzwairo, Bloodless; Hoko, Zvikomborero; Love, David; Guzha, Edward

    In resource-poor and low-population-density areas, on-site sanitation is preferred to off-site sanitation and groundwater is the main source of water for domestic uses. Groundwater pollution potential from on-site sanitation in such areas conflicts with Integrated Water Resources Management (IWRM) principles that advocate for sustainable use of water resources. Given the widespread use of groundwater for domestic purposes in rural areas, maintaining groundwater quality is a critical livelihood intervention. This study assessed impacts of pit latrines on groundwater quality in Kamangira village, Marondera district, Zimbabwe. Groundwater samples from 14 monitoring boreholes and 3 shallow wells were analysed during 6 sampling campaigns, from February 2005 to May 2005. Parameters analysed were total and faecal coliforms, NH4+-N, NO3--N, conductivity, turbidity and pH, both for boreholes and shallow wells. Total and faecal coliforms both ranged 0-TNTC (too-numerous-to-count), 78% of results meeting the 0 CFU/100 ml WHO guidelines value. NH4+-N range was 0-2.0 mg/l, with 99% of results falling below the 1.5 mg/l WHO recommended value. NO3--N range was 0.0-6.7 mg/l, within 10 mg/l WHO guidelines value. The range for conductivity values was 46-370 μS/cm while the pH range was 6.8-7.9. There are no WHO guideline values for these two parameters. Turbidity ranged from 1 NTU to 45 NTU, 59% of results meeting the 5 NTU WHO guidelines limit. Depth from the ground surface to the water table for the period February 2005 to May 2005 was determined for all sampling points using a tape measure. The drop in water table averaged from 1.1 m to 1.9 m and these values were obtained by subtracting water table elevations from absolute ground surface elevation. Soil from the monitoring boreholes was classified as sandy. The soil infiltration layer was taken as the layer between the pit latrine bottom and the water table. It averaged from 1.3 m to 1.7 m above the water table for two latrines

  7. Water and chemical budgets of gravel pit lakes : Case studies of fluvial gravel pit lakes along the Meuse River (The Netherlands) and coastal gravel pit lakes along the Adriatic Sea (Ravenna, Italy)

    NARCIS (Netherlands)

    Mollema, P.N.

    2016-01-01

    Gravel pit lakes form when gravel is excavated from below the water table of a phreatic or shallow confined aquifer. Typically many of these lakes are concentrated along naturally occurring sedimentary gravel deposits in areas where gravel is needed for construction. Most gravel pit lakes are

  8. A Bayesian approach to modeling and predicting pitting flaws in steam generator tubes

    International Nuclear Information System (INIS)

    Yuan, X.-X.; Mao, D.; Pandey, M.D.

    2009-01-01

    Steam generators in nuclear power plants have experienced varying degrees of under-deposit pitting corrosion. A probabilistic model to accurately predict pitting damage is necessary for effective life-cycle management of steam generators. This paper presents an advanced probabilistic model of pitting corrosion characterizing the inherent randomness of the pitting process and measurement uncertainties of the in-service inspection (ISI) data obtained from eddy current (EC) inspections. A Markov chain Monte Carlo simulation-based Bayesian method, enhanced by a data augmentation technique, is developed for estimating the model parameters. The proposed model is able to predict the actual pit number, the actual pit depth as well as the maximum pit depth, which is the main interest of the pitting corrosion model. The study also reveals the significance of inspection uncertainties in the modeling of pitting flaws using the ISI data: Without considering the probability-of-detection issues and measurement errors, the leakage risk resulted from the pitting corrosion would be under-estimated, despite the fact that the actual pit depth would usually be over-estimated.

  9. Markov chain model helps predict pitting corrosion depth and rate in underground pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Caleyo, F.; Velazquez, J.C.; Hallen, J. M. [ESIQIE, Instituto Politecnico Nacional, Mexico D. F. (Mexico); Esquivel-Amezcua, A. [PEMEX PEP Region Sur, Villahermosa, Tabasco (Mexico); Valor, A. [Universidad de la Habana, Vedado, La Habana (Cuba)

    2010-07-01

    Recent reports place pipeline corrosion costs in North America at seven billion dollars per year. Pitting corrosion causes the higher percentage of failures among other corrosion mechanisms. This has motivated multiple modelling studies to be focused on corrosion pitting of underground pipelines. In this study, a continuous-time, non-homogenous pure birth Markov chain serves to model external pitting corrosion in buried pipelines. The analytical solution of Kolmogorov's forward equations for this type of Markov process gives the transition probability function in a discrete space of pit depths. The transition probability function can be completely identified by making a correlation between the stochastic pit depth mean and the deterministic mean obtained experimentally. The model proposed in this study can be applied to pitting corrosion data from repeated in-line pipeline inspections. Case studies presented in this work show how pipeline inspection and maintenance planning can be improved by using the proposed Markovian model for pitting corrosion.

  10. Copper Tube Pitting in Santa Fe Municipal Water Caused by Microbial Induced Corrosion.

    Science.gov (United States)

    Burleigh, Thomas D; Gierke, Casey G; Fredj, Narjes; Boston, Penelope J

    2014-06-05

    Many copper water lines for municipal drinking water in Santa Fe, New Mexico USA, have developed pinhole leaks. The pitting matches the description of Type I pitting of copper, which has historically been attributed to water chemistry and to contaminants on the copper tubing surface. However, more recent studies attribute copper pitting to microbial induced corrosion (MIC). In order to test for microbes, the copper tubing was fixed in hexamethyldisilazane (HMDS), then the tops of the corrosion mounds were broken open, and the interior of the corrosion pits were examined with scanning electron microscopy (SEM). The analysis found that microbes resembling actinobacteria were deep inside the pits and wedged between the crystallographic planes of the corroded copper grains. The presence of actinobacteria confirms the possibility that the cause of this pitting corrosion was MIC. This observation provides better understanding and new methods for preventing the pitting of copper tubing in municipal water.

  11. Copper Tube Pitting in Santa Fe Municipal Water Caused by Microbial Induced Corrosion

    Directory of Open Access Journals (Sweden)

    Thomas D. Burleigh

    2014-06-01

    Full Text Available Many copper water lines for municipal drinking water in Santa Fe, New Mexico USA, have developed pinhole leaks. The pitting matches the description of Type I pitting of copper, which has historically been attributed to water chemistry and to contaminants on the copper tubing surface. However, more recent studies attribute copper pitting to microbial induced corrosion (MIC. In order to test for microbes, the copper tubing was fixed in hexamethyldisilazane (HMDS, then the tops of the corrosion mounds were broken open, and the interior of the corrosion pits were examined with scanning electron microscopy (SEM. The analysis found that microbes resembling actinobacteria were deep inside the pits and wedged between the crystallographic planes of the corroded copper grains. The presence of actinobacteria confirms the possibility that the cause of this pitting corrosion was MIC. This observation provides better understanding and new methods for preventing the pitting of copper tubing in municipal water.

  12. Dependence of Crystallographic Orientation on Pitting Corrosion Behavior of Ni-Fe-Cr Alloy 028

    Science.gov (United States)

    Zhang, LiNa; Szpunar, Jerzy A.; Dong, JianXin; Ojo, Olanrewaju A.; Wang, Xu

    2018-03-01

    The influence of crystallographic orientation on the pitting corrosion behavior of Ni-Fe-Cr alloy 028 was studied using a combination of X-ray diffraction (XRD), electron backscatter diffraction (EBSD), potentiodynamic polarization technique, and atomic force microscopy (AFM). The results show that there is anisotropy of pitting corrosion that strongly depends on crystallographic orientation of the surface plane. The distribution of pit density in a standard stereographic triangle indicates that the crystallographic planes close to {100} are more prone to pitting corrosion compared to planes {110} and {111}. The surface energy calculation of (001) and (111) shows that the plane with a high atomic packing density has a low surface energy with concomitant strong resistance to pitting corrosion. A correlation function between crystallographic orientation and pitting corrosion susceptibility suggests a method that not only predicts the pitting resistance of known textured materials, but also could help to improve corrosion resistance by controlling material texture.

  13. Development of pits and cones on ion bombarded copper

    International Nuclear Information System (INIS)

    Tanovic, L.A.; Carter, G.; Nobes, M.J.; Whitton, I.L.; Williams, J.S.

    1980-01-01

    The formation of pits and cones on Ar ion bombarded copper has been studied. Carefully polished surfaces of large grained 99.999% pure copper crystals have been bombarded at normal incidence with 40 keV argon ions. The cone formation has been investigated for annealed and non-annealed crystals at room temperature and at 30 K and in the case of monocrystal and polycrystal samples. Although in the most other studies the presence of impurities is as a necessary condition for generation of cones and pits the obtained experimental results show that under certain conditions these features are formed on clean surfaces. It is shown that the dominant parameter in the production of cones on copper is the crystal orientation [ru

  14. Geologic report for the Weldon Spring Raffinate Pits Site

    International Nuclear Information System (INIS)

    1984-10-01

    A preliminary geologic site characterization study was conducted at the Weldon Spring Raffinate Pits Site, which is part of the Weldon Spring Site, in St. Charles County, Missouri. The Raffinate Pits Site is under the custody of the Department of Energy (DOE). Surrounding properties, including the Weldon Spring chemical plant, are under the control of the Department of the Army. The study determined the following parameters: site stratigraphy, lithology and general conditions of each stratigraphic unit, and groundwater characteristics and their relation to the geology. These parameters were used to evaluate the potential of the site to adequately store low-level radioactive wastes. The site investigation included trenching, geophysical surveying, borehole drilling and sampling, and installing observation wells and piezometers to monitor groundwater and pore pressures

  15. Project design of an open pit colliery in Terkidag, Turkey

    Directory of Open Access Journals (Sweden)

    H. Kose

    2010-10-01

    Full Text Available In this manuscript, first of all, the status of Turkey in terms of energy production and consumption is given and the need to relyon domestic sources, namely lignite deposits, is emphasized rather than importing fuels from abroad. Then, a thorough literature workconcerning open pit design and production planning is explained in detail. On this basis, the project design and production planningof Tekirdag-Saray open pit colliery are conducted. According to the selected production technique, machinery-equipment that willbe utilized in the coal winning system is determined and in the final part, the investment cost and unit production cost regardingthe project are computed and the importance of constructing a power plant in the region operating with domestic fuels is expressed.

  16. Removal of the damaged fuel from Paks-2 pit

    International Nuclear Information System (INIS)

    Cserhati, A.

    2007-01-01

    On 10 April 2003, during the outage period a chemical cleaning program for the fuel assemblies has been carried out at the unit 2, in a specially designed cleaning tank. The tank is located in a pit, near to the reactor. 30 fuel assemblies have been significantly damaged due to inadequate cooling. After the extensive preparation - lasting 3,5 years - the pickup and encapsulation of the damaged fuel has been preformed. All tasks have been carried out safely, during the planned 3 months without any substantial problems. This paper covers the events of this last implementation phase. The main topics are: initial conditions of the pit and the cleaning tank before the start of the recovery; tasks and responsibilities, organization, timing, control.; visual following for the fuel removal; technology features, steps made; short and long term tasks after the removal of the fuel; summary, achievements. (author)

  17. Image features of herniation pit of the femoral neck

    International Nuclear Information System (INIS)

    Zhang Xuezhe; Li Guangming; Wang Cunli; Wang Guimin

    2008-01-01

    Objective: To evaluate imaging appearances of herniation pit of the femoral neck. Methods: We retrospectively analyzed the X-ray, CT and MRI findings of 9 patients with herniation pit of the femoral neck. All nine patients were male with the age ranging from 21 to 73 years. They had pain in the hip from two months to two years duration. Results: The bilateral hips were affected in six patients, the right hips in the other 3 patients. Of the nine patients, X-ray plain films (2 cases), CT scanning(6 cases), and MR scanning (5 cases ) were performed. The size of the lesions ranged from 0.5 cm x 0.6 cm to 1.0 cm x 1.5 cm, located in the anterosuperior portion of the femoral neck (n=7) or anteroinferior portion (n=2). X-ray plain films showed an osteolytic lesion surrounded by a sclerotic rim. CT scanning showed the lesion just below the cortex of the femoral neck surrounded by a rim of sclerosis or associated with a small cortical break in two patients. MR scanning showed low signal intensity in five patients on T 1 WI and high signal intensity surrounded by a rim of low signal intensity (n=3) or low signal intensity (n=2) on T 2 WI, and high signal intensity on fat suppression MR image. A small joint effusion was observed in two cases on T 2 WI. Conclusion: The CT and MRI findings of herniation pit of the femoral neck are characteristic, it is useful in defining the diagnosis of the herniation pit of the femoral neck. (authors)

  18. Measurement of unattached fractions in open-pit uranium mines

    International Nuclear Information System (INIS)

    Solomon, S.B.; Wise, K.N.

    1983-01-01

    A preliminary set of measurements of the unattached fraction of potential alpha energy was made at the Ranger open pit uranium uranium mine and the Nabarlek uranium mill. The measurement system, which incorporated a parallel plate diffusion battery and diffuse junction detectors, is described. Results for RaA show a wide variation in the unattached fraction. They range up to 0.76 and are higher than corresponding values for underground mining operations

  19. Analysis of traversable pits model to make intelligent wheeled vehicles

    Directory of Open Access Journals (Sweden)

    F. Abbasi

    2017-11-01

    Full Text Available In this paper, the issue of passing wheeled vehicles from pits is discussed. The issue is modeled by defining the limits of passing wheeled vehicles. The proposed model has been studied based on changes in the effective parameters. Finally, in order to describe the problem, the proposed model has been solved for wheeled vehicles based on the effective parameters by using one of the numerical methods.

  20. Pitting Corrosion Susceptibility of AISI 301 Stainless Steel in ...

    African Journals Online (AJOL)

    The susceptibility of austenitic (AISI 301) stainless steel to pitting corrosion was evaluated in sodium chloride (NaCl) solutions - 0.1M, 0.2M, 0.3M, 0.5M and 0.7M and 1.0M. Tensile tests and microscopic examinations were performed on samples prepared from the steel after exposure in the various environments.

  1. Composição mineral e severidade de "bitter pit" em maçãs 'Catarina' Mineral composition and bitter pit severity in 'Catarina' apples

    Directory of Open Access Journals (Sweden)

    Cassandro Vidal Talamini do Amarante

    2006-04-01

    Full Text Available Maçãs 'Catarina', colhidas na maturação comercial em pomar no município de São Joaquim-SC, foram separadas em quatro lotes de 14 frutos, de acordo com a severidade de incidência de "bitter pit": nula (nenhuma lesão/fruto, baixa (1-2 lesões/fruto, moderada (3-5 lesões/fruto e alta (6-18 lesões/fruto. Foram determinadas as concentrações de Ca, Mg, K e N na casca e na polpa de cada fruto. Foram verificadas relação linear (P 'Catarina' apples were harvested at the commercial maturity in an orchard in São Joaquim-SC and segregated in four lots of 14 fruits with different levels of bitter pit severity: null (none pit/fruit, low (1-2 pits/fruit, moderate (3-5 pits/fruit, and high (6-18 pits/fruit. Nutritional analysis (Ca, Mg, K, and N in the skin and flesh tissues were performed on individual fruits of each severity level. The average number of pits/fruit (calculated for each lot of bitter pit severity showed a negative linear relationship (P < 0.05 with the skin Ca content, and a negative linear relationship (P < 0.05 with the ratios of Mg/Ca, (K+Mg/Ca, and (K+Mg+N/Ca in the skin. For the flesh, the increasing of bitter pit severity was accompanied by significant reduction of Ca and Mg contents. The multivariate analysis (canonical discriminant analysis showed that the Mg/Ca ratio in the skin provided the best discrimination between the lots of fruit with different levels of bitter pit severity. Therefore, for 'Catarina' apples, increasing values of the Mg/Ca ratio in the skin are indicative of fruits with increasing bitter pit susceptibility.

  2. Mechanism of pitting corrosion prevention by nitrite in carbon steel exposed to dilute salt solutions. 1998 annual progress report

    International Nuclear Information System (INIS)

    Zapp, P.E.; Zee, J. van.

    1998-01-01

    'The overall goal of this project is to develop a fundamental understanding of the role of nitrite in preventing the breakdown of protective oxide(s) on carbon steel and the onset of pitting. Pitting corrosion of carbon steel exposed to dilute alkaline salt solutions can be induced by nitrate, sulfate, and chloride ions and is prevented by sufficient concentration of nitrite. A significant example of this material/electrolyte system is the storage and processing of DOE''s high-level radioactive liquid waste in carbon steel tanks. Added nitrite in the waste has a considerable downstream impact on the immobilization of the waste in a stable glass form. Waste tank integrity and glass production efficiency may benefit from the fundamental understanding of nitrite''s role in preventing pitting. This report summarizes progress after approximately six months of effort in this three-year EMSP project. Initial experimental and theoretical work has focused on the electrochemical behavior of carbon steel in simplified non-radioactive solutions that simulate complex dilute radioactive waste solutions. These solutions contain corrosion-inducing species such as nitrate and chloride and the corrosion-inhibiting nitrite at moderately alkaline pHs. The electrochemical behavior of interest here is that of the open-circuit potential of the steel specimen at equilibrium in the experimental electrolyte and the measures of the steel''s passivity and passivity breakdown.'

  3. Comparison between Windrow and Pit Composting of Poultry Wastes, Leaves and Garbage of Municipal Solid Waste in Damghan, Iran

    Directory of Open Access Journals (Sweden)

    Yaghmaeian K, Malakootian M, Noorisepehr M

    2005-01-01

    Full Text Available Basic principles of Integrated Solid Waste Management (ISWM are: Reduction, Reuse, Recycling and Recovery (4Rs. Composting as an element of ISWM strategy that can be applied to separately collected or mixed wastes, is a controlled aerobic process carried out by successive microbial populations combining both mesophilic and thermophilic activities and leading to the production of carbon dioxide, water, minerals and stabilized organic matter. In this research, comparing between windrow and pit co-composting methods was studied in the city of Damghan, Iran. Waste proportioning was done based on C/N ratio (about 25:1 and moisture content (about 55%. Mixed wastes were located in windrow and pit with natural aeration tunnel. Sufficient oxygen supply was provided in the piles of compostable materials in two systems through frequent turning of the piles in 7 d intervals during the first month. Temperature reached to maximum level in 10-15 d and then depleted (days: 20-25. It reached to the safety level (about 60˚C based on U.S.EPA and WHO recommendations. Finally, compost was produced with pH=7.7, dark brown color and 30- 35% moisture content. N, P, K, organic matter and organic carbon were measured by standard methods. Results were compared with WHO and U.S.EPA recommendations showing suitable conditions Also it was indicated that pit method was better for maintaining temperature, nitrogen, organic C and organic matter.

  4. Spontaneous Resolution of Long-Standing Macular Detachment due to Optic Disc Pit with Significant Visual Improvement.

    Science.gov (United States)

    Parikakis, Efstratios A; Chatziralli, Irini P; Peponis, Vasileios G; Karagiannis, Dimitrios; Stratos, Aimilianos; Tsiotra, Vasileia A; Mitropoulos, Panagiotis G

    2014-01-01

    To report a case of spontaneous resolution of a long-standing serous macular detachment associated with an optic disc pit, leading to significant visual improvement. A 63-year-old female presented with a 6-month history of blurred vision and micropsia in her left eye. Her best-corrected visual acuity was 6/24 in the left eye, and fundoscopy revealed serous macular detachment associated with optic disc pit, which was confirmed by optical coherence tomography (OCT). The patient was offered vitrectomy as a treatment alternative, but she preferred to be reviewed conservatively. Three years after initial presentation, neither macular detachment nor subretinal fluid was evident in OCT, while the inner segment/outer segment (IS/OS) junction line was intact. Her visual acuity was improved from 6/24 to 6/12 in her left eye, remaining stable at the 6-month follow-up after resolution. We present a case of spontaneous resolution of a long-standing macular detachment associated with an optic disc pit with significant visual improvement, postulating that the integrity of the IS/OS junction line may be a prognostic factor for final visual acuity and suggesting OCT as an indicator of visual prognosis and the probable necessity of a surgical management.

  5. Spontaneous Resolution ofLong-Standing Macular Detachment due to Optic Disc Pit with Significant Visual Improvement

    Directory of Open Access Journals (Sweden)

    Efstratios A. Parikakis

    2014-03-01

    Full Text Available Purpose: To report a case of spontaneous resolution of a long-standing serous macular detachment associated with an optic disc pit, leading to significant visual improvement. Case Presentation: A 63-year-old female presented with a 6-month history of blurred vision and micropsia in her left eye. Her best-corrected visual acuity was 6/24 in the left eye, and fundoscopy revealed serous macular detachment associated with optic disc pit, which was confirmed by optical coherence tomography (OCT. The patient was offered vitrectomy as a treatment alternative, but she preferred to be reviewed conservatively. Three years after initial presentation, neither macular detachment nor subretinal fluid was evident in OCT, while the inner segment/outer segment (IS/OS junction line was intact. Her visual acuity was improved from 6/24 to 6/12 in her left eye, remaining stable at the 6-month follow-up after resolution. Conclusion: We present a case of spontaneous resolution of a long-standing macular detachment associated with an optic disc pit with significant visual improvement, postulating that the integrity of the IS/OS junction line may be a prognostic factor for final visual acuity and suggesting OCT as an indicator of visual prognosis and the probable necessity of a surgical management.

  6. Restoration of Secondary Containment in Double Shell Tank (DST) Pits

    Energy Technology Data Exchange (ETDEWEB)

    SHEN, E.J.

    2000-10-05

    Cracks found in many of the double-shell tank (DST) pump and valve pits bring into question the ability of the pits to provide secondary containment and remain in compliance with State and Federal regulations. This study was commissioned to identify viable options for maintain/restoring secondary containment capability in these pits. The basis for this study is the decision analysis process which identifies the requirements to be met and the desired goals (decision criteria) that each option will be weighed against. A facilitated workshop was convened with individuals knowledgeable of Tank Farms Operations, engineering practices, and safety/environmental requirements. The outcome of this workshop was the validation or identification of the critical requirements, definition of the current problem, identification and weighting of the desired goals, baselining of the current repair methods, and identification of potential alternate solutions. The workshop was followed up with further investigations into the potential solutions that were identified in the workshop and through other efforts. These solutions are identified in the body of this report. Each of the potential solutions were screened against the list of requirements and only those meeting the requirements were considered viable options. To expand the field of viable options, hybrid concepts that combine the strongest features of different individual approaches were also examined. Several were identified. The decision analysis process then ranked each of the viable options against the weighted decision criteria, which resulted in a recommended solution. The recommended approach is based upon installing a sprayed on coating system.

  7. Micro pit formation by mercury-sphere collision

    International Nuclear Information System (INIS)

    Ishikura, Syuichi; Kogawa, Hiroyuki; Futakawa, Masatoshi; Kaminaga, Masanori; Hino, Ryutaro

    2004-01-01

    The development of a MW-class spallation neutron source facility is being carried out under the Japan Proton Accelerator Research Complex (J-PARC) Project promoted by JAERI and KEK. A mercury target working as the spallation neutron source will be subjected to pressure waves generated by rapid thermal expansion of mercury due to a pulsed proton beam injection. The pressure wave will impose dynamic stress on the vessel and deform the vessel, which would cause cavitation in mercury. To evaluate the effect of mercury micro jets, driven by cavitation bubble collapse, on the micro-pit formation, analyses on mercury sphere collision were carried out: single bubble dynamics and collision behavior on interface between liquid and solid, which take the nonlinearity due to shock wave in mercury and the strain rate dependency of yield stress in solid metal into account. Analytical results give a good explanation to understand relationship between the micro-pit formation and material properties: the pit size could decrease with increasing the yield strength of materials. (author)

  8. Women miners in developing countries: pit women and others

    Energy Technology Data Exchange (ETDEWEB)

    Kuntala Lahiri-Dutt; Martha Macintyre [Australian National University (Australia). Research School of Pacific and Asian Studies

    2006-05-15

    Contrary to their masculine portrayal, mines have always employed women in valuable and productive roles. Yet, pit life continues to be represented as a masculine world of work, legitimizing men as the only mineworkers and large, mechanized, and capitalized operations as the only form of mining. Bringing together a range of case studies of women miners from past and present in Asia, the Pacific Region, Latin America and Africa, this book makes visible the roles and contributions of women as miners. It also highlights the importance of engendering small and informal mining in the developing world as compared to the early European and American mines. The book shows that women are engaged in various kinds of mining and illustrates how gender and inequality are constructed and sustained in the mines, and also how ethnic identities intersect with those gendered identities. Chapters dealing with coal mining include: Introduction: Where life is in the pits (and elsewhere) and gendered; Japanese coal mining: women discovered; Mining gender at work in the Indian collieries: identity construction; Women in the mining industry of contemporary China; Roti do, ya goli do! (give us bread, or give us bullets!): stories of struggles of women workers in Bhowra colliery, India and Globalization and women's work in the mine pits in East Kalimantan, Indonesia. 17 ills.

  9. Water quality in gravel pits in the Bratislava area

    International Nuclear Information System (INIS)

    Flakova, R.; Rohacikova, A.; Zenisova, Z.

    1999-01-01

    The gravel pits around Bratislava have an esthetic, urban and recreational function. Open water table areas are in a direct contact with the air and acquire some characteristics of the surface water. The quality of open water table is much more susceptible to pollution than that of groundwater. Wet and dry deposition, water inflow from the surrounding surface, unmanageable sewerage effluents, solid and liquid wastes, but also the water birds contribute to the pollution. The Department of Hydrogeology has monitored the water quality in six gravel pits (Cunovo, Drazdiak, Strkovec, Pasienky, Zlate Piesky, Vajnory) since 1976 with an an interruption between 1988 - 1993. Two sampling per year have been made since 1994 and after 1998 the analyses have been supplemented by Na, K, Fe, Mn, by oxygen regime parameters, by trace elements (As, Ag, Cd, Co, Cu, Cr, Hg, Ni, Pb, V, Zn) and by organic pollutants. As regards the oxygen regime, the water quality pits is very good. The anthropogenic influence is expressed mainly by the increased contents of sulfates and chlorides. Most problematic trace elements are the mercury and vanadium (Drazdiak, Zlate Piesky and Vajnory). (authors)

  10. Restoration of Secondary Containment in Double Shell Tank (DST) Pits

    International Nuclear Information System (INIS)

    SHEN, E.J.

    2000-01-01

    Cracks found in many of the double-shell tank (DST) pump and valve pits bring into question the ability of the pits to provide secondary containment and remain in compliance with State and Federal regulations. This study was commissioned to identify viable options for maintain/restoring secondary containment capability in these pits. The basis for this study is the decision analysis process which identifies the requirements to be met and the desired goals (decision criteria) that each option will be weighed against. A facilitated workshop was convened with individuals knowledgeable of Tank Farms Operations, engineering practices, and safety/environmental requirements. The outcome of this workshop was the validation or identification of the critical requirements, definition of the current problem, identification and weighting of the desired goals, baselining of the current repair methods, and identification of potential alternate solutions. The workshop was followed up with further investigations into the potential solutions that were identified in the workshop and through other efforts. These solutions are identified in the body of this report. Each of the potential solutions were screened against the list of requirements and only those meeting the requirements were considered viable options. To expand the field of viable options, hybrid concepts that combine the strongest features of different individual approaches were also examined. Several were identified. The decision analysis process then ranked each of the viable options against the weighted decision criteria, which resulted in a recommended solution. The recommended approach is based upon installing a sprayed on coating system

  11. Open pit coal exploitation viability. Margarita mine. Case of study

    International Nuclear Information System (INIS)

    Veloza, Julia; Molina, Jorge; Mejia, Humberto

    2006-01-01

    This paper provides an analysis of financial viability, planning and design for the new coal open pit exploitation for La Margarita mine, with coal-resources estimated on 440.139,7 ton. Dimension, design and economic evaluation were possible by three exploitation methods: (multiple bench, open cast contour, and terraces). Net present values (NVP) were calculated: $c 817,5; $c 518,5 and $c 645,2 respectively for each method (given in million current Colombian pesos $. $c 2380 are equivalent to $us 1) and rate of return (ROR) 78,33%; 34,0% and 38,62% respectively for each method. These indicators served as a parameter to choose the multiple bench method, which should be recalculated because it was necessary to work jointly with two pits and making feasible the project. in addition a general environmental evaluation was done, which is vital for the exploitation. Important impacts on the flower, animals, air, water were found, and measures of control, prevention and mitigation were stated. it is expected that this paper can be useful as a technical-economical support for the development of the open pit exploitation in the margarita mine

  12. Oil sands mine pit wall design and performance at Syncrude

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, R.; Danku, M; Purhar, G. [Syncrude Canada Ltd., Fort McMurray, AB (Canada)

    2008-07-01

    This study conducted slope stability analyses in order to compare pit performance at an oil sands mine with results from computerized simulations using conventionally known soil parameters. Ranges included fully-drained to fully-saturated piezometric conditions; full-peak strength conditions; fully-softened peak conditions; residual shear strength conditions; and undrained shear strength considerations. Pit wall designs were reviewed and a history of marine clay layers at the mine was presented. Assumed overburden fall-down limits were considered. Shovel overburden slope angles were calculated. An analysis of the review suggested that steeper pit walls provide less room for error and have a higher rate of failures. Incised pleistocene channels, joint and fracture areas as well as higher piezometric level areas also impacted on slope performance. Failed areas influenced ore volumes and led to productivity reductions below 50 per cent. It was concluded that the overburden portions of the oil sands mine ranged between 4H:1V to 5H:1V due to haul roads and the timing of top-bench pushbacks. Future plans for the mine must consider ore inventories, haul road requirements; running surface requirements; and ramping accesses. Future slopes at the oil sands mine will be buttressed with overburden and tailings storage areas, while longer-term slopes will be flattened. 6 refs., 2 tabs., 11 figs.

  13. Investigation of the pitting corrosion of low carbon steel containers

    International Nuclear Information System (INIS)

    Mughabghab, S.F.; Sullivan, T.M.

    1988-01-01

    The present study was undertaken because the prediction of the degradation rate of low carbon steel contains over long time frames is one of the crucial elements in the development of a source term model for low-level shallow land burial. The principal data base considered is that of the NBS corrosion measurements of ferrous materials buried in the ground for periods of up to 18 years. In this investigation, the maximum penetration in mils, hm, due to pitting corrosion was found to conform closely to the relation h m = kt n where it is the exposure time of the sample in years, κ is the pitting parameter in mil/(years) n , and n > O is a parameter related to the aeration property of the soil. The central objective of the present investigation is the determination of the dependence of the pitting parameters κ and n on the soil properties. The result of a detailed linear correlation analysis of κ on one hand, the pH value and the resistivity of the soil on the other hand revealed that κ is principally influenced by the pH value of the soil. The resistivity of the soil is found to play a minor role

  14. A preliminary pit slope stability study Kvanefjeld, South Greenland

    International Nuclear Information System (INIS)

    Kalvig, P.

    1983-11-01

    On the basis of 1300 field measurements of joint planes, four individual structural regions have been outlined in the Kvanefjeld area. Potential failure planes and planes which are unlikely to be involved in slope failures are identified. Failures seem, not likely to occur on walls dipping SW or NE respectively, but may occur on walls dipping NM. The factors of safety for each region are calculated in order to determine the sensibility of the overall slope to different overall slope angles. The factors of safety does only exceed the required factor of safety of 1.5 in one of the structural regions. Changing the overall pit slope inclination from 55deg to 45deg improves the security, but even still not satisfactorily for two of the regions. At 45deg overall pit slope in parts of the pit implies additional 14.3 x 10 6 tonnes of non-mineralized material to be mined, thus resulting in a total mineralized- to non-mineralized material ratio about 1.0: 1.7. (author)

  15. Remediation of flare pit soils using supercritical fluid extraction

    Energy Technology Data Exchange (ETDEWEB)

    Nagpal, V.; Guigard, S.E. [Alberta Univ., Edmonton, AB (Canada). Dept. of Civil Engineering

    2005-09-01

    A laboratory study was conducted to examine the ability of supercritical fluid extraction (SFE) to remove petroleum hydrocarbons (PHCs) from two flare pit soils in Alberta. SFE is a technology for remediation of contaminated soils. In order to determine the optimal extraction conditions and to understand the effects of pressure, temperature, supercritical carbon dioxide flow rate, soil type, and extraction time on the extraction efficiency of SFE, extractions were performed on two flare pit soils at various pressures and temperatures. Chemicals in the study included diesel oil, SAE 10-30W motor oil, n-decane, hexadecane, tetratriacontane and pentacontane. The best extraction conditions were defined as conditions that result in a treated soil with a PHC concentration that meets the regulatory guidelines of the Canadian Council of Ministers of the Environment in the Canada-wide standard for PHC is soil. The study results indicate that the efficiency of the SFE process is solvent-density dependent for the conditions studied. The highest extraction efficiency for both soils was obtained at conditions of 24.1 MPa and 40 degrees C. An increase in pressure at a fixed temperature led to an increase in the extraction efficiency while an increase in temperature at a fixed pressure led to a decrease in the extraction efficiency. The treated soils were observed to be lighter in colour, drier, and grainier than the soil prior to extraction. It was concluded that SFE is an effective method for remediating flare pit soils. 63 refs., 4 tabs., 5 figs.

  16. Study of ex-vessel steam explosion risk of Reactor Pit Flooding System and structural response of containment for CPR1000"+ Unit

    International Nuclear Information System (INIS)

    Zhang Juanhua; Chen Peng

    2015-01-01

    Reactor Pit Flooding System is one of the special mitigation measures for severe accident for CPR1000"+ Unit. If the In-Vessel Relocation function of Reactor Pit Flooding System is failed, there is the steam explosion risk in reactor cavity. This paper firstly adopts MC3D code to build steam explosion model in order to calculate the pressure load and impulses of steam explosion that are as the input data of containment structural response analysis. The next step is to model the containment structure and analyze the structural response by ABAQUS code. The analysis results show that the integral damage induced by steam explosion to the external containment wall is shallow, and the containment structural integrity can be maintained. The risk and damage to the containment integrity reduced by steam explosion of RPF is small, and it does not influence the design and implementation of RPF. (author)

  17. Single Amino Acid Insertion in Loop 4 Confers Amphotropic Murine Leukemia Virus Receptor Function upon Murine Pit1

    DEFF Research Database (Denmark)

    Lundorf, Mikkel D.; Pedersen, Finn Skou; O'Hara, Bryan

    1998-01-01

    Pit1 is the human receptor for gibbon ape leukemia virus (GALV) and feline leukemia virus subgroup B (FeLV-B), while the related human protein Pit2 is a receptor for amphotropic murine leukemia virus (A-MuLV). The A-MuLV-related isolate 10A1 can utilize both Pit1 and Pit2 as receptors. A stretch...

  18. Treatment of sulphated water of surface origin produced by an open pit coal mine

    Directory of Open Access Journals (Sweden)

    Alan Campos-Sánchez

    2016-12-01

    Full Text Available The purpose of this study was to select the most suitable method of treatment of sulfated water produced by an open pit coal mine in Venezuela. Samples of water taken on surface, middle and bottom of water bodies in three areas were subjected to basic, gravimetric, volumetric and colorimetric analysis. The results indicated that the pH is within limits permitted by current environmental regulations, while total suspended solids, total dissolved solids, and sulfates exceed the normed values. The aerobic wetland method was selected as the most efficient for the removal of sulfates, depending on the physicochemical characteristics of the sulphated waters from the mine and because they are systems that use natural energy to purify water, its construction and maintenance costs Is significantly inferior to the conventional treatments and because, being replicas of natural ecosystems, they are integrated to the environment.

  19. Canister Storage Building Receiving Pit Modification Informal Design Verification

    International Nuclear Information System (INIS)

    KRIEG, S.A.

    2000-01-01

    The design for modifications to the CSB Cask Receiving pit guides was verified by the informal design verification (meeting) method on August 9, 2000. The invited list of attendees and the meeting attendance sheet are included in attachment 1. The design modifications that were reviewed are documented in ECN 654484 (attachment 2). The requirement that the design is to be verified against is to ''center the transportation cask sufficiently to allow installation of the guide funnel on the cask (± 0.25 inches or less)''. The alternatives considered are detailed in attachment 3. Alternative number 4, ''Modify The Pit Guides'', was determined to be the preferred alternative primarily due to considerations of simplicity, reliability, and low cost. Alternative 1, ''Rotate the impact Absorber 180 o '', was successfully performed but was considered a temporary fix that was not acceptable for a long term operational mode. The requirement to position the receiving crane accurately enough to lower the transportation cask into the pit with the redesigned guides was discussed and considered to be achievable without undue effort from the operator. The tolerance on the OD of the transfer cask was discussed (± 1/8 inch) relative to the clearance with the guides. As-built dimensions for the cask OD will be looked at to verify sufficient clearance exists with the maximum cask OD. The final design thickness of the shims under the guides will be based on the as-built cask OD dimensions and field measurements between the pit guides. The need for a ''plastic'' cover for the guides was discussed and deemed unnecessary. Thermal growth of the cask OD was calculated at 3-5 mils and considered insignificant. The possibility of reducing the OD of the guide funnel was reviewed but this was considered impractical due to the requirement for the MCO to miss the edge of the funnel in case of a MCO drop. One of the transportation casks have the lift trunions installed 3/8 inch off center. This is

  20. Fokker-Planck modeling of pitting corrosion in underground pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Camacho, Eliana Nogueira [Risco Ambiental Engenharia, Rio de Janeiro, RJ (Brazil); Melo, Paulo F. Frutuoso e [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Saldanha, Pedro Luiz C. [Comissao Nacional de Energia Nuclear (CGRC/CNEN), Rio de Janeiro, RJ (Brazil). Coordenacao Geral de Reatores e Ciclo do Combustivel; Silva, Edson de Pinho da [Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropedica, RJ (Brazil). Dept. of Physics

    2011-07-01

    Full text: The stochastic nature of pitting corrosion has been recognized since the 1930s. It has been learned that this damage retains no memory of its past. Instead, the future state is determined only by the knowledge of its present state. This Markovian property that underlies the stochastic process governing pitting corrosion has been explored as a discrete Markovian process by many authors since the beginning of the 1990s for underground pipelines of the oil and gas industries and nuclear power plants. Corrosion is a genuine continuous time and space state Markovian process, so to model it as a discrete time and/or state space is an approximation to the problem. Markovian chains approaches, with an increasing number of states, could involve a large number of parameters, the transition rates between states, to be experimentally determined. Besides, such an increase in the number of states produces matrices with huge dimensions leading to time-consuming computational solutions. Recent approaches involving Markovian discrete process have overcome those difficulties but, on the other hand, a large number of soil and pipe stochastic variables have to be known. In this work we propose a continuous time and space state approach to the evolution of pit corrosion depths in underground pipelines. In order to illustrate the application of the model for defect depth growth a combination of real life data and Monte Carlo simulation was used. The process is described by a Fokker-Planck equation. The Fokker-Planck equation is completely determined by the knowledge of two functions known as the drift and diffusion coefficients. In this work we also show that those functions can be estimated from corrosion depth data from in-line inspections. Some particular forms of drift and diffusion coefficients lead to particular Fokker-Planck equations for which analytical solutions are known, as is the case for the Wiener process, the Ornstein-Uhlenbeck process and the Brownian motion

  1. Retrospective Analysis of Mosh-Pit-Related Injuries.

    Science.gov (United States)

    Milsten, Andrew M; Tennyson, Joseph; Weisberg, Stacy

    2017-12-01

    Moshing is a violent form of dancing found world-wide at rock concerts, festivals, and electronic dance music events. It involves crowd surfing, shoving, and moving in a circular rotation. Moshing is a source of increased morbidity and mortality. The goal of this study was to report epidemiologic information on patient presentation rate (PPR), transport to hospital rate (TTHR), and injury patterns from patients who participated in mosh-pits. Materials and Methods Subjects were patrons from mosh-pits seeking medical care at a single venue. The events reviewed were two national concert tours which visited this venue during their tour. The eight distinct events studied occurred between 2011 and 2014. Data were collected retrospectively from prehospital patient care reports (PCRs). A single Emergency Medical Service (EMS) provided medical care at this venue. The following information was gathered from each PCR: type of injury, location of injury, treatment received, alcohol or drug use, Advanced Life Support/ALS interventions required, age and gender, disposition, minor or parent issues, as well as type of activity engaged in when injured. Attendance for the eight events ranged from 5,100 to 16,000. Total patient presentations ranged from 50 to 206 per event. Patient presentations per ten thousand (PPTT) ranged from 56 to 130. The TTHR per 10,000 ranged from seven to 20. The mean PPTT was 99 (95% CI, 77-122) and the median was 98. The mean TTHR was 16 (95% CI, 12-29) and the median TTHR was 17. Patients presenting from mosh-pits were more frequently male (57.6%; Psurfing was the next most significant, accounting for 20% of presentations. The most common body part injured was the head (64% of injuries). This retrospective review of mosh-pit-associated injury patterns demonstrates a high rate of injuries and presentations for medical aid at the evaluated events. General moshing was the most commonly associated activity and the head was the most common body part injured

  2. Influence of lubricant on the pitting capacity of gears. Comparison and discussion of main pitting test methods

    Energy Technology Data Exchange (ETDEWEB)

    Hoehn, Bernd-Robert; Oster, Peter; Tobie, Thomas; Hergesell, Maria [Forschungsstelle fuer Zahnraeder und Getriebebau, Technische Univ. Muenchen, Garching (Germany)

    2009-07-01

    The lubricant in a gearbox should provide a separating lubricating film between the meshing teeth. Furthermore its main task is the evacuation of the developing heat. Hence the lubricant is also an important influence parameter on the pitting life time of gearsets. Due to the constantly rising demands for higher power transmission of gearsets, also higher demands are made against the performance of the lubricants. In order to quantify the capability and to choose the appropriate lubricant for each application, reliable testing methods are necessary. Therefor today different testing methods are available. Two of the main pitting testing methods are the Standard Pittingtest according to FVA 2/IV [2] and its advancement, the Practice Relevant Pittingtest according to FVA 371 [4]. For the Practice Relevant Pittingtest test gears with profile modification and lengthwise crowning are used, which are superfinished. For the introduction of the Practice Relevant Pittingtest into industrial application a round robin test was performed in co-operation with FVA and DGMK. This paper is discussing the today usual testing methods regarding the pitting load capacity of lubricants and their characteristics in comparison. Furthermore the results of the round robin test and further example results, including pictures of typical pittings, are presented. In addition it is demonstrated, how to deal with the results. On the basis of test experience, knowledge from research projects and other examples typical questions concerning the different testing methods are discussed. Thereby essential requirements for reliable and reproducible results are pointed out and possible limits for the application of the test methods are represented. (orig.)

  3. Effects of selected water chemistry variables on copper pitting propagation in potable water

    International Nuclear Information System (INIS)

    Ha Hung; Taxen, Claes; Williams, Keith; Scully, John

    2011-01-01

    Highlights: → The effects of water composition on pit propagation kinetics on Cu were separated from pit initiation and stabilization using the artificial pit method in a range of dilute HCO 3 - , SO 4 2- and Cl - -containing waters. → The effective polarization and Ohmic resistance of pits were lower in SO4 2- -containing solutions and greater in Cl - -containing solutions. → Relationship between the solution composition and the corrosion product identity and morphology were found. → These, in turn controlled the corrosion product Ohmic resistance and subsequently the pit growth rate. - Abstract: The pit propagation behavior of copper (UNS C11000) was investigated from an electrochemical perspective using the artificial pit method. Pit growth was studied systematically in a range of HCO 3 - , SO 4 2- and Cl - containing-waters at various concentrations. Pit propagation was mediated by the nature of the corrosion products formed both inside and over the pit mouth (i.e., cap). Certain water chemistry concentrations such as those high in sulfate were found to promote fast pitting that could be sustained over long times at a fixed applied potential but gradually stifled in all but the lowest concentration solutions. In contrast, Cl - containing waters without sulfate ions resulted in slower pit growth and eventual repassivation. These observations were interpreted through understanding of the identity, amount and porosity of corrosion products formed inside and over pits. These factors controlled their resistive nature as characterized using electrochemical impedance spectroscopy. A finite element model (FEM) was developed which included copper oxidation kinetics, transport by migration and diffusion, Cu(I) and Cu(II) solid corrosion product formation and porosity governed by equilibrium thermodynamics and a saturation index, as well as pit current and depth of penetration. The findings of the modeling were in good agreement with artificial pit experiments

  4. Force-displacement measurements of earlywood bordered pits using a mesomechanical tester.

    Science.gov (United States)

    Zelinka, Samuel L; Bourne, Keith J; Hermanson, John C; Glass, Samuel V; Costa, Adriana; Wiedenhoeft, Alex C

    2015-10-01

    The elastic properties of pit membranes are reported to have important implications in understanding air-seeding phenomena in gymnosperms, and pit aspiration plays a large role in wood technological applications such as wood drying and preservative treatment. Here we present force-displacement measurements for pit membranes of circular bordered pits, collected on a mesomechanical testing system. The system consists of a quartz microprobe attached to a microforce sensor that is positioned and advanced with a micromanipulator mounted on an inverted microscope. Membrane displacement is measured from digital image analysis. Unaspirated pits from earlywood of never-dried wood of Larix and Pinus and aspirated pits from earlywood of dried wood of Larix were tested to generate force-displacement curves up to the point of membrane failure. Two failure modes were observed: rupture or tearing of the pit membrane by the microprobe tip, and the stretching of the pit membrane until the torus was forced out of the pit chamber through the pit aperture without rupture, a condition we refer to as torus prolapse. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

  5. Investigation of Stress Concentration and Casing Strength Degradation Caused by Corrosion Pits

    Directory of Open Access Journals (Sweden)

    Wei Yan

    2016-01-01

    Full Text Available Downhole casing and tubing are subjected to corrosion in many cases because of the exposure to corrosive environment. A more serious problem is that pitting corrosion occurs in the casing inner surface. Meanwhile, downhole strings are subjected to various forms of mechanical loads, for example, internal pressure load, external collapse load, or both. These loads acting on the corrosion pits will cause stress concentration and degrade the casing strength. Thus, it is essential to evaluate the stress concentration degree reasonably. The SCF (stress concentration factor is usually used to characterize the degree of stress concentration induced by corrosion pits. This paper presented a comparison on the SCFs regarding the analytical method for a single pit and experimental method for double pits. The results show that the SCF of a single pit depends mainly on the depth of the corrosion pit; however, the SCF of the double pits strongly depends on the pits distance. A correction factor of 1.3 was recommended in the double pits SCF prediction model.

  6. Numerical simulation of the double pits stress concentration in a curved casing inner surface

    Directory of Open Access Journals (Sweden)

    Wei Yan

    2016-12-01

    Full Text Available Sour or sweet oil fields development is common in recent years. Casing and tubing are usually subjected to pitting corrosion because of exposure to the strong corrosion species, such as CO2, H2S, and saline water. When the corrosion pits formed in the casing inner surface, localized stress concentration will occur and the casing strength will be degraded. Thus, it is essential to evaluate the degree of stress concentration factor accurately. This article performed a numerical simulation on double pits stress concentration factor in a curved inner surface using the finite element software ABAQUS. The results show that the stress concentration factor of double pits mainly depends on the ratio of two pits distance to the pit radius (L/R. It should not be only assessed by the absolute distance between the two pits. When the two pits are close and tangent, the maximum stress concentration factor will appear on the inner tangential edges. Stress concentration increased by double pits in a curved casing inner surface is more serious than that in a flat surface. A correction factor of 1.9 was recommended in the curved inner surface double pits stress concentration factor predict model.

  7. Least tern and piping plover nesting at sand pits in Nebraska

    Science.gov (United States)

    Sidle, John G.; Kirsch, E.M.

    1993-01-01

    Endangered Least Terns (Sterna antillarum) and threatened Piping Plovers (Charadrius melodus) nest at commercial sand and gravel mining operations (sand pits) along the Platte River system in Nebraska. Sandbar habitat has been disappearing since the early 1900's along the Platte River system, but numbers of sand pits have increased. We hypothesized that birds would more fully utilize sand pits where suitable sandbar habitat was limited. We inventoried sand pits and censused terns and plovers on both habitats along the Loup River, part of the North Loup River, and most of the Platte River during 1988-1991. Using aircraft, we also quantified features of suitable sand pits present on the central Platte in 1988 and lower Platte in 1990, and related features to abundance and presence of birds. We found 225 sand pits of which 78 were suitable and 187 were unsuitable for nesting. Along the central Platte, where sandbar habitat is severely degraded, birds nested at 81% of the suitable sand pits (N = 32) at least once during 1988-1991, and most birds (61-94%) nested on sand pits. Along the lower Platte, where both sandbar and sand pit habitat are plentiful, birds nested at 60% of the suitable sand pits (N = 35) at least once during 1988-1991, and most birds (60-86%) nested on sandbars. Numbers of terns and plovers were more weakly correlated with features of sand pits on the central Platte than on the lower Platte. Least Terns and Piping Plovers seem to use more of the suitable sand pit habitat on the central Platte than on the lower Platte. Sand pits probably have influenced the birds' distribution by providing alternative nesting habitat along rivers where suitable sandbars are rare or absent.

  8. Structures of Bordered Pits Potentially Contributing to Isolation of a Refilled Vessel from Negative Xylem Pressure in Stems of Morus australis Poir.: Testing of the Pit Membrane Osmosis and Pit Valve Hypotheses.

    Science.gov (United States)

    Ooeda, Hiroki; Terashima, Ichiro; Taneda, Haruhiko

    2017-02-01

    Two hypotheses have been proposed to explain the mechanism preventing the refilling vessel water from being drained to the neighboring functional vessels under negative pressure. The pit membrane osmosis hypothesis proposes that the xylem parenchyma cells release polysaccharides that are impermeable to the intervessel pit membranes into the refilling vessel; this osmotically counteracts the negative pressure, thereby allowing the vessel to refill. The pit valve hypothesis proposes that gas trapped within intervessel bordered pits isolates the refilling vessel water from the surrounding functional vessels. Here, using the single-vessel method, we assessed these hypotheses in shoots of mulberry (Morus australis Poir.). First, we confirmed the occurrence of xylem refilling under negative pressure in the potted mulberry saplings. To examine the pit membrane osmosis hypothesis, we estimated the semi-permeability of pit membranes for molecules of various sizes and found that the pit membranes were not semi-permeable to polyethylene glycol of molecular mass osmosis mechanism in mulberry would be unrealistically large. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  9. The Solid Waste Transfer Pit an FFTF [Fast Flux Test Facility] station for fuel and reflector transfer

    International Nuclear Information System (INIS)

    Milewski, A.J.; Thomson, J.D.

    1985-01-01

    This paper describes the design aspects of a proposed FFTF facility called the Solid Waste Transfer Pit (SWTP). This new facility will be used as a transfer station for reflectors and/or low decay heat fuel assemblies when movement from the Fuel Storage Facility for sodium removal and subsequent reprocessing is to be accomplished. The SWTP utilizes a shielded cell cover with an integral manually-operated gate valve for top loading of a transfer vessel. The cost-effective design discussed herein provides a practical approach using state-of-the-art concepts while assuring safe and reliable operation

  10. Pitting Corrosion of Ni3(Si,Ti Intermetallic Compound at Various Chloride Concentrations

    Directory of Open Access Journals (Sweden)

    Gadang Priyotomo

    2013-10-01

    Full Text Available The pitting corrosion of Ni3(Si,Ti intermetallic compound was investigated as function of chloride concentration by using electrochemical method and scanning electron microscope in sodium chloride solutions at 293 K.  In addition, the pitting corrosion of type C276 alloy was also studied under the same experimental condition for comparison.  The pitting potential obtained for the intermetallic compound decreased with increasing chloride concentration.  The specific pitting potential and pitting potential of Ni3(Si,Ti were lower than those of C276 alloy, which means that the pitting corrosion resistance of C276 alloy was higher than that of Ni3(Si,Ti.

  11. Probability distribution of pitting corrosion depth and rate in underground pipelines: A Monte Carlo study

    International Nuclear Information System (INIS)

    Caleyo, F.; Velazquez, J.C.; Valor, A.; Hallen, J.M.

    2009-01-01

    The probability distributions of external-corrosion pit depth and pit growth rate were investigated in underground pipelines using Monte Carlo simulations. The study combines a predictive pit growth model developed by the authors with the observed distributions of the model variables in a range of soils. Depending on the pipeline age, any of the three maximal extreme value distributions, i.e. Weibull, Frechet or Gumbel, can arise as the best fit to the pitting depth and rate data. The Frechet distribution best fits the corrosion data for long exposure periods. This can be explained by considering the long-term stabilization of the diffusion-controlled pit growth. The findings of the study provide reliability analysts with accurate information regarding the stochastic characteristics of the pitting damage in underground pipelines.

  12. Probability distribution of pitting corrosion depth and rate in underground pipelines: A Monte Carlo study

    Energy Technology Data Exchange (ETDEWEB)

    Caleyo, F. [Departamento de Ingenieria Metalurgica, ESIQIE, IPN, UPALM Edif. 7, Zacatenco, 07738 Mexico, D.F. (Mexico)], E-mail: fcaleyo@gmail.com; Velazquez, J.C. [Departamento de Ingenieria Metalurgica, ESIQIE, IPN, UPALM Edif. 7, Zacatenco, 07738 Mexico, D.F. (Mexico); Valor, A. [Facultad de Fisica, Universidad de La Habana, San Lazaro y L, Vedado, 10400, La Habana (Cuba); Hallen, J.M. [Departamento de Ingenieria Metalurgica, ESIQIE, IPN, UPALM Edif. 7, Zacatenco, 07738 Mexico, D.F. (Mexico)

    2009-09-15

    The probability distributions of external-corrosion pit depth and pit growth rate were investigated in underground pipelines using Monte Carlo simulations. The study combines a predictive pit growth model developed by the authors with the observed distributions of the model variables in a range of soils. Depending on the pipeline age, any of the three maximal extreme value distributions, i.e. Weibull, Frechet or Gumbel, can arise as the best fit to the pitting depth and rate data. The Frechet distribution best fits the corrosion data for long exposure periods. This can be explained by considering the long-term stabilization of the diffusion-controlled pit growth. The findings of the study provide reliability analysts with accurate information regarding the stochastic characteristics of the pitting damage in underground pipelines.

  13. Detection of simulated pitting corrosion and noises in crude oil storage tank by acoustic emission

    International Nuclear Information System (INIS)

    Shukri Mohd; Latif, N.A.; Azhar Mohd Sinin; Mohamad Daud; Abd Nasir Ibrahim

    2008-01-01

    The damage mechanisms associated with crude oil storage tanks can be complex and varied and include pitting corrosion due to presence of species such as sulphate reducing bacteria. Acoustic Emission (AE) could be used to characterise the pitting corrosion signal in crude oil storage tanks but it is extremely difficult to simulate the pitting corrosion in the laboratory using crude oil as electrolyte because crude oil is considered as non corrosive medium. In this study, induced current have been introduced onto a surface ASTM 516 steel as an electrical source to simulate the electrical noise produced during pitting corrosion process and AE sensor have been used to detect this current. It is found that AE system could detect AE signal release during current induction this current and is expected that if the exact simulation of the current magnitude produced during pitting corrosion process is made available, AE characterisation of pitting corrosion in such tank could be made possible. (Author)

  14. Pitting morphologies of zirconium base alloys in aqueous and non aqueous chloride media

    International Nuclear Information System (INIS)

    Palit, G.C.; Gadiyar, H.S.

    1988-01-01

    Pitting morphology of zirconium and Zr-Cr alloys in aqueous chloride and nonaqueous methanol + 0.4 per cent HCl solution was investigated and observed to follow different modes in these two environments. While in aqueous chloride solution pitting was transgranular and randomly oriented, in methanol-chloride solution pits were observed to initiate and propagate along the grain boundaries. In aqueous chloride solution very irregular and sponge like zirconium metal was formed inside the pit while in methanol-chloride solution the pits were crystallographic in nature. Optical microscopy has revealed that pits preferentially initiate and propagate along scratch line in aqueous chloride solution, but such was not the case in nonaqueous methanol-chloride solution. The nature and the mechanism operating in the catastropic failure of these materials are investigated. (author). 10 refs., 11 figs

  15. The role of inclusions in the pitting behaviour of maraging steel

    International Nuclear Information System (INIS)

    Ahmad, M.S.; Hussain, S.W.; Ashraf, H.

    1999-01-01

    The pitting characteristics of maraging steel in artificial seawater have been investigated electrochemically using the cyclic polarization technique. Pits were found to be associated with the inclusions present in steel. The hysteresis loop observed indicates that maraging steel has poor resistance to pitting in air saturated seawater. On examination of corroded surfaces under SEM, it is noted that the pits are always associated with inclusions, which are generally the carbonitrides of TiMo presents in maraging steel in varying quantities depending on the melting practice. In order to confirm that the pitting behavior is associated with inclusions, samples from clean maraging steel, having very low inclusion level, were tested. Such samples showed much less tendency for pitting. (author)

  16. Stochastic modeling of pitting corrosion in underground pipelines using Markov chains

    Energy Technology Data Exchange (ETDEWEB)

    Velazquez, J.C.; Caleyo, F.; Hallen, J.M.; Araujo, J.E. [Instituto Politecnico Nacional (IPN), Mexico D.F. (Mexico). Escuela Superior de Ingenieria Quimica e Industrias Extractivas (ESIQIE); Valor, A. [Universidad de La Habana, La Habana (Cuba)

    2009-07-01

    A non-homogenous, linear growth (pure birth) Markov process, with discrete states in continuous time, has been used to model external pitting corrosion in underground pipelines. The transition probability function for the pit depth is obtained from the analytical solution of the forward Kolmogorov equations for this process. The parameters of the transition probability function between depth states can be identified from the observed time evolution of the mean of the pit depth distribution. Monte Carlo simulations were used to predict the time evolution of the mean value of the pit depth distribution in soils with different physicochemical characteristics. The simulated distributions have been used to create an empirical Markov-chain-based stochastic model for predicting the evolution of pitting corrosion from the observed properties of the soil in contact with the pipeline. Real- life case studies, involving simulated and measured pit depth distributions are presented to illustrate the application of the proposed Markov chains model. (author)

  17. Numerical Simulation of Interactions between Corrosion Pits on Stainless Steel under Loading Conditions

    International Nuclear Information System (INIS)

    Wang, Haitao; Han, En-Hou

    2017-01-01

    The interactions between corrosion pits on stainless steel under loading conditions are studied by using a cellular automata model coupled with finite element method at a mesoscopic scale. The cellular automata model focuses on a metal/film/electrolyte system, including anodic dissolution, passivation, diffusion of hydrogen ions and salt film hydrolysis. The Chopard block algorithm is used to improve the diffusion simulation efficiency. The finite element method is used to calculate the stress concentration on the pit surface during pit growth, and the effect of local stress and strain on anodic current is obtained by using the Gutman model, which is used as the boundary conditions of the cellular automata model. The transient current characteristics of the interactions between corrosion pits under different simulation factors including the breakdown of the passive film at the pit mouth and the diffusion of hydrogen ions are analyzed. The analysis of the pit stability product shows that the simulation results are close to the experimental conclusions.

  18. Numerical Simulation of Interactions between Corrosion Pits on Stainless Steel under Loading Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Haitao; Han, En-Hou [Chinese Academy of Sciences, Shenyang (China)

    2017-04-15

    The interactions between corrosion pits on stainless steel under loading conditions are studied by using a cellular automata model coupled with finite element method at a mesoscopic scale. The cellular automata model focuses on a metal/film/electrolyte system, including anodic dissolution, passivation, diffusion of hydrogen ions and salt film hydrolysis. The Chopard block algorithm is used to improve the diffusion simulation efficiency. The finite element method is used to calculate the stress concentration on the pit surface during pit growth, and the effect of local stress and strain on anodic current is obtained by using the Gutman model, which is used as the boundary conditions of the cellular automata model. The transient current characteristics of the interactions between corrosion pits under different simulation factors including the breakdown of the passive film at the pit mouth and the diffusion of hydrogen ions are analyzed. The analysis of the pit stability product shows that the simulation results are close to the experimental conclusions.

  19. Development of a passive and remote magnetic microsensor with thin-film giant magnetoimpedance element and surface acoustic wave transponder

    KAUST Repository

    Al Rowais, Hommood; Li, Bodong; Liang, Cai; Green, Scott Ryan; Gianchandani, Yogesh B.; Kosel, Jü rgen

    2011-01-01

    This paper presents the development of a wireless magnetic field sensor consisting of a three-layer thin-film giant magnetoimpedance sensor and a surface acoustic wave device on one substrate. The goal of this integration is a passive and remotely interrogated sensor that can be easily mass fabricated using standard microfabrication tools. The design parameters, fabrication process, and a model of the integrated sensor are presented together with experimental results of the sensor. © 2011 American Institute of Physics.

  20. Exfoliation Corrosion and Pitting Corrosion and Their Role in Fatigue Predictive Modeling: State-of-the-Art Review

    Directory of Open Access Journals (Sweden)

    David W. Hoeppner

    2012-01-01

    Full Text Available Intergranular attack (IG and exfoliation corrosion (EC have a detrimental impact on the structural integrity of aircraft structures of all types. Understanding the mechanisms and methods for dealing with these processes and with corrosion in general has been and is critical to the safety of critical components of aircraft. Discussion of cases where IG attack and exfoliation caused issues in structural integrity in aircraft in operational fleets is presented herein along with a much more detailed presentation of the issues involved in dealing with corrosion of aircraft. Issues of corrosion and fatigue related to the structural integrity of aging aircraft are introduced herein. Mechanisms of pitting nucleation are discussed which include adsorption-induced, ion migration-penetration, and chemicomechanical film breakdown theories. In addition, pitting corrosion (PC fatigue models are presented as well as a critical assessment of their application to aircraft structures and materials. Finally environmental effects on short crack behavior of materials are discussed, and a compilation of definitions related to corrosion and fatigue are presented.

  1. Superficial drainage studies in open-pit mines

    International Nuclear Information System (INIS)

    Teixeira Junior, P.B.; Leite, C.B.B.

    1984-01-01

    Drainage studies concerning large open-pit mining projects can be of vital importance throughout the mining activity itself as they may assist in avoiding activity interruptions due to drainage problems, therefore representing substantial savings. These studies should, in fact, be carried out from the initial activity stages and shall be considered in operational, project and planning decisions in order to optimize results and reduce costs. This specific study presents a drainage study systematization proposal, enphasazing economic decision criteria. The authors comment on studies of this nature developed at the Caldas uranium mine - NUCLEBRAS. (D.J.M.) [pt

  2. Proposed open-pit mine threatens Jasper National Park

    Energy Technology Data Exchange (ETDEWEB)

    Mikelcic, S.

    1996-12-31

    Concerns by the Sierra Club, the Alberta Wilderness Association, and other environmental groups about the proposed Cheviot Mine are discussed. Cardinal River Coals, which is owned by Luscar Ltd. and Consolidated Coals of Pittsburgh, is proposing the mining operation, which includes 26 deep open pit mines of which 14 will not be backfilled. The mine extends to within 2 km of Jasper National Park`s border. Concerns about the mine include: disruption of an environmentally sensitive area, interference with grizzly bear movement and bighorn sheep habitat and diet, destruction of flora and fauna, and pollution of two major watersheds. Hearings for the mine commence in January 1997.

  3. TMI-2 auxiliary building elevator shaft and pit decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Bengel, T.G.

    1986-01-01

    Decontamination of the elevator pit and shaft in the auxiliary building at Three Mile Island Unit 2 (TMI-2) was performed to remove high radiation and contamination levels which prevented personnel from utilizing the elevator. The radiation and contamination levels in the TMI-2 auxiliary building elevator shaft have been reduced to the point where plant personnel are again permitted to ride in the elevator without a radiation work permit, with the exception of access to the 281-ft (basement) level. Based on the declassification and expanded use of the elevator, the task goal has been met. The tax expended 16.16 man-rem and 621 man-hours.

  4. In the pit: a Cape Breton coal miner

    Energy Technology Data Exchange (ETDEWEB)

    MacKenzie, R.; Caplan, R. (ed.)

    2001-07-01

    This is an account of the mining life of a coal miner in Nova Scotia from 1951 to 1969. The author was born in New Waterford and worked there, in Numbers 12 and 18 Colliery. Many of his experiences and observations from working at the coal face are described. These include accounts of hauling coal in the pit, driving a diesel, and the coming of mechanization. Mining community life is included as background material. A brief history of 12 Colliery (1908-1975) is included. 12 figs.

  5. Familial occurrence of lip pits: A case report

    Directory of Open Access Journals (Sweden)

    Motesaddi Zaranadi M

    2002-06-01

    Full Text Available Lip pits are among the rarest congenital deformities recorded. Initially reported in 1845, it’s familial occurrence has been reported just once. These developmental anomalies occur either as an isolated defect or in association with other developmental deformities including cleft lip, cleft palate or both. It may be located at the commisures of the lips or in the midline of the lower lip. It is often inherited as an autosomal dominant trait with variable penetrance.Our report of a family in which all of the three children (two girls and a boy and their father wre involved in concert with the latter statement.

  6. Electrochemical tests for pitting and crevice corrosion susceptibility

    International Nuclear Information System (INIS)

    Postlethwaite, J.

    1983-01-01

    Passive metals are being considered as container materials for the disposal of nuclear waste by deep burial. Localized corrosion is a potential problem and electrochemical techniques have an important role in the assessment of the susceptibility of these container materials to crevice and pitting corrosion. This paper critically reviews both the theoretical background and the experimental details of the electrochemical test methods presently used in both industrial and scientific studies of localized corrosion in both halide and non-halide solutions and identifies those areas where theory and experimental behaviour are in agreement and those areas for which there is neither well established theory nor an experimental test method

  7. Storage and Management of Open-pit Transportation Path

    Directory of Open Access Journals (Sweden)

    Jiusheng Du

    2013-07-01

    Full Text Available This paper is aiming at the actual demand of open-pit mine daily production scheduling and positioning monitoring. After extracting data from existing topographic maps and other information, it discusses the feasibility of using this data to establish thematic database. By considering the extensive application of GPS data, utilizing new spatial data types of SQL Server 2008 for data storage and management. Extracting data algorithms such as the node spatial data, the regional boundary and the path are implemented, then spatial data storage and management is also realized. It provides the basis for the production of decision-making and production cost savings.

  8. Itataia's deposit - Structural zoning of a pit until the level 480 meters

    International Nuclear Information System (INIS)

    Mendonca, J.C.G.S.

    1986-01-01

    This work is part of Itataia Project-Geotechnics; in it are introduced several comments concerning the structural zoning of a pit in Itataias' phosphorous-uranipherous deposit, until the level 480 meters. The structural parameters (fractures, faults, foliations) obtained in surface and underground works were statistically treated. Stereographic projection was used to define eventual slipping into the pit. All the data were arranged in tables to make it easy the comparison with experimental pits. (author) [pt

  9. Prediction of the net radon emission from a model open pit uranium mine

    International Nuclear Information System (INIS)

    Nielson, K.K.; Perkins, R.W.; Schwendiman, L.C.; Enderlin, W.I.

    1979-04-01

    Radon emission from a model open pit uranium mining operation has been estimated by applying radon exhalation fluxes measured in an open pit uranium mine to the various areas of the model mine. The model mine was defined by averaging uranium concentrations and production and procedural statistics for eight major open pit uranium mines in the Casper, Wyoming area. The resulting emission rates were 740 Ci/AFR during mining operations and 33 Ci/AFR/yr after abandonment of the mine

  10. Criticality safety evaluation report for the 100 KE Basin sandfilter backwash pit

    International Nuclear Information System (INIS)

    Erickson, D.G.

    1995-01-01

    This analysis presents the technical basis for establishing a safe mass limit for continued operations of the KE Basin sandfilter backwash pit. The main analysis is based on a very conservative UO 2 -PuO 2 -H 2 O system using the measured isotopic concentrations of uranium and plutonium in the sludge. Appendix C contains analyses of the sandfilter backwash pit utilizing all verified materials presently in the pit, and gives new limits based on assumptions made

  11. The use of different techniques for determination of pitting corrosion potential of austenitic stainless steel

    International Nuclear Information System (INIS)

    Eskelinen, P.; Forsen, O.; Onnela, J.; Ylaesaari, S.; Haenninen, H.

    1992-01-01

    Three different techniques for pitting corrosion potential measurement on austenitic stainless steel (Fe18Cr10Ni) were compared: conventional polarization method, a new Avesta electrochemical corrosion measurement cell and a scratch technique. Special attention was paid to the effects of crevice corrosion during pitting corrosion potential measurement and to their elimination. Development of a rapid test technique for reliable pitting corrosion potential determination was aimed at and resulted from comparison of the different techniques

  12. INFLUENCE OF PIT WALL ANCHORAGE ONTO ADDITIONAL DEFORMATIONS OF EXISTING BUILDINGS

    Directory of Open Access Journals (Sweden)

    Kubetskiy Valeriy Leonidovich

    2012-07-01

    Assessment of additional projected deformations of buildings located in close proximity to pits is exemplified by the specific structure of the pit support system that has active PIT [1] anchors. The authors also consider the influence produced by the structure of anchors onto the two buildings located within the area of influence of the excavation works and protected by the anchors installed underneath the foundations of the two adjacent buildings.

  13. Mud Pit Risk-Based Closure Strategy Report, Nevada Test Site, Nevada, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Brain Hoenes

    2004-08-01

    This report presents the findings of the human and ecological risk assessment for the NTS mud pits. The risk assessment utilizes data from 52 of the 270 NTS mud pits in conjunction with corroborative data from 87 other DOE mud pits associated with nuclear testing (at locations on the NTS, in the western United States, and Alaska) as well as relevant process knowledge. Based on the risk assessment findings, the report provides a strategy for further evaluation, characterization, and closure of all 270 NTS mud pit CASs using the Streamlined Approach for Environmental Restoration (SAFER).

  14. Criticality analysis for weapon disassembly at the Pantex Plant - part I: Bare pits

    Energy Technology Data Exchange (ETDEWEB)

    Knief, R.A. [Ogden Environmental & Energy Services, Albuquerque, NM (United States)

    1997-06-01

    This paper briefly describes criticality investigations for weapon assembly and dismantlement at the Pantex Plant. Results are summarized for calculations performed for safety analyses, radiological hazards assessments, and a study to justify the criticality alarm exemption. Pits and pits in containers were modeled in their most reactive configuration. Criticality calculations were performed with the KENO and MCNP code packages. Configurations involving bare pits were subcritical by a substantial amount even with very conservative model assumptions. Thus, it is concluded that a critical configuration involving the bare pits is not credible.

  15. TRANSITIONS IN ELECTROCHEMICAL NOISE DURING PITTING CORROSION OF ALUMINUM IN CHLORIDE ENVIRONMENTS

    International Nuclear Information System (INIS)

    SASAKI, K.; ISAACS, H.S.; LEVY, P.W.

    2001-01-01

    Aluminum, in a chloride containing solutions close to its pitting potential, shows vigorous fluctuations in current and potential. Measurements have been made of the freely corroding potential, and the currents between interconnected electrodes. It is shown that there is a transition in the behavior of the transients. The transition occurs when multiple active pits are present and electrochemical communication occurs between them. The major source of current and potential transients is the growth process in the active pits rather than meta-stable pitting at the passive surface

  16. Research on horizontal displacement monitoring method of deep foundation pit based on laser projecting sensing technology

    Science.gov (United States)

    Liu, Peng; Xie, Shulin; Zhang, Lixiao; Zhou, Guangyi; Zhao, Xuefeng

    2018-03-01

    A certain level of horizontal displacement will occur during excavation or subsequent construction of deep foundation pit. If the support is improper and the horizontal displacement of the foundation pit is too large, it will cause collapse and even affect the buildings around the foundation pit, which will endanger people's life and property. Therefore, the horizontal displacement monitoring of deep foundation pit becomes more and more important. At present, the electronic total station is often used to monitor the horizontal displacement of the foundation pit, but this monitoring method is expensive, prone to accidental errors, and can not be used for real-time monitoring. Therefore, a method of monitoring the horizontal displacement of deep foundation pit by using laser projection sensing technique is proposed in this paper. The horizontal displacement of the foundation pit is replaced by the displacement of the laser spot emitted by the laser, and the horizontal displacement of the foundation pit can be obtained by identifying the displacement of the laser spot projected on the screen. A series of experiments show that the accuracy of this monitoring method meets the engineering requirements and greatly reduces the cost, which provides a new technology for the displacement monitoring of deep foundation pit.

  17. Effect of nitrite concentration on pit depth in carbon steel exposed to simulated radioactive waste

    International Nuclear Information System (INIS)

    Zapp, P.E.

    1997-01-01

    The growth of pits in carbon steel exposed to dilute (0.055 M nitrate-bearing) alkaline salt solutions that simulate radioactive waste was investigated in coupon immersion tests. Most coupons were tested in the as-received condition, with the remainder having been heat treated to produce an oxide film. Nitrite, which is an established pitting inhibitor in these solutions, was present in concentrations from 0 to 0.031 M to 0.16 M; the last concentration is known to prevent pitting initiation in the test solution at the 50 degrees C test temperature. The depths of the deepest pits on coupons of particular exposure conditions were measure microscopically and were analyzed as simple, type 1 extreme value statistical distributions, to predict the deepest expected pit in a radioactive waste tank subject to the test conditions. While the growth rate of pits could not be established from these tests, the absolute value of the deepest pits predicted is of the order of 100 mils after 448 days of exposure. The data indicate that even nitrite concentrations insufficient to prevent pitting have a beneficial effect on limiting the growth of deepest pits

  18. Reliable identification of deep sulcal pits: the effects of scan session, scanner, and surface extraction tool.

    Directory of Open Access Journals (Sweden)

    Kiho Im

    Full Text Available Sulcal pit analysis has been providing novel insights into brain function and development. The purpose of this study was to evaluate the reliability of sulcal pit extraction with respect to the effects of scan session, scanner, and surface extraction tool. Five subjects were scanned 4 times at 3 MRI centers and other 5 subjects were scanned 3 times at 2 MRI centers, including 1 test-retest session. Sulcal pits were extracted on the white matter surfaces reconstructed with both Montreal Neurological Institute and Freesurfer pipelines. We estimated similarity of the presence of sulcal pits having a maximum value of 1 and their spatial difference within the same subject. The tests showed high similarity of the sulcal pit presence and low spatial difference. The similarity was more than 0.90 and the spatial difference was less than 1.7 mm in most cases according to different scan sessions or scanners, and more than 0.85 and about 2.0 mm across surface extraction tools. The reliability of sulcal pit extraction was more affected by the image processing-related factors than the scan session or scanner factors. Moreover, the similarity of sulcal pit distribution appeared to be largely influenced by the presence or absence of the sulcal pits on the shallow and small folds. We suggest that our sulcal pit extraction from MRI is highly reliable and could be useful for clinical applications as an imaging biomarker.

  19. Reliable identification of deep sulcal pits: the effects of scan session, scanner, and surface extraction tool.

    Science.gov (United States)

    Im, Kiho; Lee, Jong-Min; Jeon, Seun; Kim, Jong-Heon; Seo, Sang Won; Na, Duk L; Grant, P Ellen

    2013-01-01

    Sulcal pit analysis has been providing novel insights into brain function and development. The purpose of this study was to evaluate the reliability of sulcal pit extraction with respect to the effects of scan session, scanner, and surface extraction tool. Five subjects were scanned 4 times at 3 MRI centers and other 5 subjects were scanned 3 times at 2 MRI centers, including 1 test-retest session. Sulcal pits were extracted on the white matter surfaces reconstructed with both Montreal Neurological Institute and Freesurfer pipelines. We estimated similarity of the presence of sulcal pits having a maximum value of 1 and their spatial difference within the same subject. The tests showed high similarity of the sulcal pit presence and low spatial difference. The similarity was more than 0.90 and the spatial difference was less than 1.7 mm in most cases according to different scan sessions or scanners, and more than 0.85 and about 2.0 mm across surface extraction tools. The reliability of sulcal pit extraction was more affected by the image processing-related factors than the scan session or scanner factors. Moreover, the similarity of sulcal pit distribution appeared to be largely influenced by the presence or absence of the sulcal pits on the shallow and small folds. We suggest that our sulcal pit extraction from MRI is highly reliable and could be useful for clinical applications as an imaging biomarker.

  20. Large heterogeneities in comet 67P as revealed by active pits from sinkhole collapse.

    Science.gov (United States)

    Vincent, Jean-Baptiste; Bodewits, Dennis; Besse, Sébastien; Sierks, Holger; Barbieri, Cesare; Lamy, Philippe; Rodrigo, Rafael; Koschny, Detlef; Rickman, Hans; Keller, Horst Uwe; Agarwal, Jessica; A'Hearn, Michael F; Auger, Anne-Thérèse; Barucci, M Antonella; Bertaux, Jean-Loup; Bertini, Ivano; Capanna, Claire; Cremonese, Gabriele; Da Deppo, Vania; Davidsson, Björn; Debei, Stefano; De Cecco, Mariolino; El-Maarry, Mohamed Ramy; Ferri, Francesca; Fornasier, Sonia; Fulle, Marco; Gaskell, Robert; Giacomini, Lorenza; Groussin, Olivier; Guilbert-Lepoutre, Aurélie; Gutierrez-Marques, P; Gutiérrez, Pedro J; Güttler, Carsten; Hoekzema, Nick; Höfner, Sebastian; Hviid, Stubbe F; Ip, Wing-Huen; Jorda, Laurent; Knollenberg, Jörg; Kovacs, Gabor; Kramm, Rainer; Kührt, Ekkehard; Küppers, Michael; La Forgia, Fiorangela; Lara, Luisa M; Lazzarin, Monica; Lee, Vicky; Leyrat, Cédric; Lin, Zhong-Yi; Lopez Moreno, Josè J; Lowry, Stephen; Magrin, Sara; Maquet, Lucie; Marchi, Simone; Marzari, Francesco; Massironi, Matteo; Michalik, Harald; Moissl, Richard; Mottola, Stefano; Naletto, Giampiero; Oklay, Nilda; Pajola, Maurizio; Preusker, Frank; Scholten, Frank; Thomas, Nicolas; Toth, Imre; Tubiana, Cecilia

    2015-07-02

    Pits have been observed on many cometary nuclei mapped by spacecraft. It has been argued that cometary pits are a signature of endogenic activity, rather than impact craters such as those on planetary and asteroid surfaces. Impact experiments and models cannot reproduce the shapes of most of the observed cometary pits, and the predicted collision rates imply that few of the pits are related to impacts. Alternative mechanisms like explosive activity have been suggested, but the driving process remains unknown. Here we report that pits on comet 67P/Churyumov-Gerasimenko are active, and probably created by a sinkhole process, possibly accompanied by outbursts. We argue that after formation, pits expand slowly in diameter, owing to sublimation-driven retreat of the walls. Therefore, pits characterize how eroded the surface is: a fresh cometary surface will have a ragged structure with many pits, while an evolved surface will look smoother. The size and spatial distribution of pits imply that large heterogeneities exist in the physical, structural or compositional properties of the first few hundred metres below the current nucleus surface.

  1. Pitting corrosion of Inconel 600 in chloride and sulfate solutions at low temperature

    International Nuclear Information System (INIS)

    Chang Mingyu; Yu Geping

    1993-01-01

    Pitting corrosion of Inconel 600 was examined in chloride and sulfate solutions through usage of potentiodynamic polarization techniques. The effects of chloride and sulfate concentration were investigated in the range of 0.0001 to 0.1 M. Increasing chloride concentrations resulted in active shifts of the pit nucleation potential. Immunity to pitting corrosion was evident at a chloride level below 0.005 M. Increasing sulfate concentrations resulted in improved pitting resistance of Inconel 600 in chloride solutions. Detrimental effects associated with pitting were evident with low-level sulfate being added to dilute chloride media. The density of pits increased with increasing chloride concentrations or temperature between room temperature and 70 C. Systematic trends for the depth of pits were not evident. The observations of pitting corrosion in open immersion were consistent with those in polarization methods. Corrosion products contained in the pits were enriched in nickel, chromium and iron with a small amount of titanium and silicon. The enrichment of chlorine or sulfur was still, however, not found. (orig.)

  2. TRANSITIONS IN ELECTROCHEMICAL NOISE DURING PITTING CORROSION OF ALUMINUM IN CHLORIDE ENVIRONMENTS.

    Energy Technology Data Exchange (ETDEWEB)

    SASAKI,K.; ISAACS,H.S.; LEVY,P.W.

    2001-09-02

    Aluminum, in a chloride containing solutions close to its pitting potential, shows vigorous fluctuations in current and potential. Measurements have been made of the freely corroding potential, and the currents between interconnected electrodes. It is shown that there is a transition in the behavior of the transients. The transition occurs when multiple active pits are present and electrochemical communication occurs between them. The major source of current and potential transients is the growth process in the active pits rather than meta-stable pitting at the passive surface.

  3. Investigation of the pitting of aluminum induced by chloride ions by holographic microphotography

    Directory of Open Access Journals (Sweden)

    LIANG LI

    2008-05-01

    Full Text Available Holographic microphotography was used to investigate the dynamic processes of pitting during anodic dissolution of aluminum in a solution containing chloride ions. The induction and the follow-up propagation processes of the pitting were observed in real-time. A simple model of the propagating process of the pitting was deduced from the result of the holograms of the Al/electrolyte interface. The results prove that holographic microphotography is a useful tool to study the dynamic processes of pitting.

  4. A rare nonsyndromic presentation of bilateral doughnut shaped lip pits in an Indian child

    Directory of Open Access Journals (Sweden)

    Senthil Balasubramani

    2016-01-01

    Full Text Available Lip pits are a rare congenital anomaly that presents on the upper or lower lip or the commissure of the lips. Lip pits are an autosomal dominant trait occurring almost always in association with cleft lip or palate. They most commonly occur in association with developmental disturbances such as Van der Woude's syndrome, popliteal pterygium syndrome, oro-facial-digital syndrome, Marres-Cremers syndrome, and Hirschsprung disease. Its occurrence in nonsyndromic individuals is extremely rare with only a handful of cases reported. The identification of lip pits with other associated anomalies is crucial for genetic counseling; we report a case of nonsyndromic presentation of bilateral lip pits.

  5. Pit morphology studies of iron and steel in alkaline chloride environment using EMPA technique

    International Nuclear Information System (INIS)

    Benjamin, S.E.; Sykes, J.M.

    1993-01-01

    A comparative study of iron and steel in stimulated alkaline chloride solutions showed that Swedish iron has better reproducibility in terms of pitting potentials as compared to ordinary hot rolled mild steel. This study was undertaken to reason this pitting behavior on the basis of number and the nature of inclusions present in both the metals. Electron probe microanalysis technique (EPMA) was utilised to contemplate the origin of pits, the solution chemistry of the pits and finally the nature of the rust product. (author)

  6. Venomics of New World pit vipers: genus-wide comparisons of venom proteomes across Agkistrodon.

    Science.gov (United States)

    Lomonte, Bruno; Tsai, Wan-Chih; Ureña-Diaz, Juan Manuel; Sanz, Libia; Mora-Obando, Diana; Sánchez, Elda E; Fry, Bryan G; Gutiérrez, José María; Gibbs, H Lisle; Sovic, Michael G; Calvete, Juan J

    2014-01-16

    We report a genus-wide comparison of venom proteome variation across New World pit vipers in the genus Agkistrodon. Despite the wide variety of habitats occupied by this genus and that all its taxa feed on diverse species of vertebrates and invertebrate prey, the venom proteomes of copperheads, cottonmouths, and cantils are remarkably similar, both in the type and relative abundance of their different toxin families. The venoms from all the eleven species and subspecies sampled showed relatively similar proteolytic and PLA2 activities. In contrast, quantitative differences were observed in hemorrhagic and myotoxic activities in mice. The highest myotoxic activity was observed with the venoms of A. b. bilineatus, followed by A. p. piscivorus, whereas the venoms of A. c. contortrix and A. p. leucostoma induced the lowest myotoxic activity. The venoms of Agkistrodon bilineatus subspecies showed the highest hemorrhagic activity and A. c. contortrix the lowest. Compositional and toxicological analyses agree with clinical observations of envenomations by Agkistrodon in the USA and Central America. A comparative analysis of Agkistrodon shows that venom divergence tracks phylogeny of this genus to a greater extent than in Sistrurus rattlesnakes, suggesting that the distinct natural histories of Agkistrodon and Sistrurus clades may have played a key role in molding the patterns of evolution of their venom protein genes. A deep understanding of the structural and functional profiles of venoms and of the principles governing the evolution of venomous systems is a goal of venomics. Isolated proteomics analyses have been conducted on venoms from many species of vipers and pit vipers. However, making sense of these large inventories of data requires the integration of this information across multiple species to identify evolutionary and ecological trends. Our genus-wide venomics study provides a comprehensive overview of the toxic arsenal across Agkistrodon and a ground for

  7. Venomics of New World pit vipers: Genus-wide comparisons of venom proteomes across Agkistrodon

    Science.gov (United States)

    Lomonte, Bruno; Tsai, Wan-Chih; Ureña-Diaz, Juan Manuel; Sanz, Libia; Mora-Obando, Diana; Sánchez, Elda E.; Fry, Bryan G.; Gutiérrez, José María; Gibbs, H. Lisle; Sovic, Michael G.; Calvete, Juan J.

    2015-01-01

    We report a genus-wide comparison of venom proteome variation across New World pit vipers in the genus Agkistrodon. Despite the wide variety of habitats occupied by this genus and that all its taxa feed on diverse species of vertebrates and invertebrate prey, the venom proteomes of copperheads, cottonmouths, and cantils are remarkably similar, both in the type and relative abundance of their different toxin families. The venoms from all the eleven species and subspecies sampled showed relatively similar proteolytic and PLA2 activities. In contrast, quantitative differences were observed in hemorrhagic and myotoxic activities in mice. The highest myotoxic activity was observed with the venoms of A. b. bilineatus, followed by A. p. piscivorus, whereas the venoms of A. c. contortrix and A. p. leucostoma induced the lowest myotoxic activity. The venoms of Agkistrodon bilineatus subspecies showed the highest hemorrhagic activity and A. c. contortrix the lowest. Compositional and toxicological analyses agree with clinical observations of envenomations by Agkistrodon in the USA and Central America. A comparative analysis of Agkistrodon shows that venom divergence tracks phylogeny of this genus to a greater extent than in Sistrurus rattlesnakes, suggesting that the distinct natural histories of Agkistrodon and Sistrurus clades may have played a key role in molding the patterns of evolution of their venom protein genes. Biological significance A deep understanding of the structural and functional profiles of venoms and of the principles governing the evolution of venomous systems is a goal of venomics. Isolated proteomics analyses have been conducted on venoms from many species of vipers and pit vipers. However, making sense of these large inventories of data requires the integration of this information across multiple species to identify evolutionary and ecological trends. Our genus-wide venomics study provides a comprehensive overview of the toxic arsenal across

  8. Treatment of pit water from uranium mining operation

    International Nuclear Information System (INIS)

    Mouton, A.; Lafforgue, P.; Lyaudet, G.

    1984-01-01

    The pit water from uranium mines is normally treated to eliminate the soluble radium and suspended solids. The radium is precipitated together with the barium sulphate. The latter results from the reaction of barium chloride with an excess of sulphate ions. The suspended solids are flocculated by aluminium salts (chloride, polychloride). If necessary, synthetic flocculants are also used. Certain grades of pit water contain, sometimes incidentally, a few milligrams of uranium per litre. These quantities always remain too low for any direct recovery (treatment by ion exchange resins). By applying certain measures, the preceding processes can also be used to eliminate uranium. The latter is carried away by aluminium hydroxide in a very narrow zone of pH (6 to 7,4) which corresponds to the minimum solubility of the hydroxide. Depending on the characteristic of the water (pH, salinity), use is made either of aluminium sulphate or of sodium aluminate, with an addition of a base in extreme cases. This article gives various examples of applications in the Haute-Vienne, Chardon in Vendee, the Commanderie mine in Vendee, at Cerilly in Allier and at Lodeve in Herault [fr

  9. Off-line tests on pitting damage in mercury target

    International Nuclear Information System (INIS)

    Futakawa, Masatoshi; Kogawa, Hiroyuki; Ishikura, Shuichi; Ikeda, Yujiro

    2003-03-01

    A liquid-mercury target system for the MW-scale target is being developed in the world. The moment the proton beams bombard the target, stress waves will be imposed on the beam window and pressure waves will be generated in the mercury by the thermally shocked heat deposition. Provided that the negative pressure generates through its propagation in the mercury target and causes cavitation in the mercury, there is the possibility for the cavitation bubbles collapse to form pits on the interface between the mercury and the target vessel wall. In order to estimate the cavitation erosion damage due to pitting, two types of off-line tests were performed: Split Hopkinson Pressure Bar (SHPB), and Magnetic IMpact Testing Machine (MIMTM). The data on the piping damage at the high cycle impacts up to 10 million were given by the MIMTM. Additionally the data obtained were compared with classical vibratory horn tests. As a result, it is confirmed that the mean depth erosion is predictable using a homologous line in the steady state with mass loss independently of testing machines and the incubation period is very dependent on materials and imposed pressures. (author)

  10. Off-line tests on pitting damage in mercury target

    CERN Document Server

    Futakawa, M; Ishikura, S; Kogawa, H; Tsai, C C

    2003-01-01

    A liquid-mercury target system for the MW-scale target is being developed in the world. The moment the proton beams bombard the target, stress waves will be imposed on the beam window and pressure waves will be generated in the mercury by the thermally shocked heat deposition. Provided that the negative pressure generates through its propagation in the mercury target and causes cavitation in the mercury, there is the possibility for the cavitation bubbles collapse to form pits on the interface between the mercury and the target vessel wall. In order to estimate the cavitation erosion damage due to pitting, two types of off-line tests were performed: Split Hopkinson Pressure Bar (SHPB), and Magnetic IMpact Testing Machine (MIMTM). The data on the piping damage at the high cycle impacts up to 10 million were given by the MIMTM. Additionally the data obtained were compared with classical vibratory horn tests. As a result, it is confirmed that the mean depth erosion is predictable using a homologous line in the s...

  11. Inconsistent identification of pit bull-type dogs by shelter staff.

    Science.gov (United States)

    Olson, K R; Levy, J K; Norby, B; Crandall, M M; Broadhurst, J E; Jacks, S; Barton, R C; Zimmerman, M S

    2015-11-01

    Shelter staff and veterinarians routinely make subjective dog breed identification based on appearance, but their accuracy regarding pit bull-type breeds is unknown. The purpose of this study was to measure agreement among shelter staff in assigning pit bull-type breed designations to shelter dogs and to compare breed assignments with DNA breed signatures. In this prospective cross-sectional study, four staff members at each of four different shelters recorded their suspected breed(s) for 30 dogs; there was a total of 16 breed assessors and 120 dogs. The terms American pit bull terrier, American Staffordshire terrier, Staffordshire bull terrier, pit bull, and their mixes were included in the study definition of 'pit bull-type breeds.' Using visual identification only, the median inter-observer agreements and kappa values in pair-wise comparisons of each of the staff breed assignments for pit bull-type breed vs. not pit bull-type breed ranged from 76% to 83% and from 0.44 to 0.52 (moderate agreement), respectively. Whole blood was submitted to a commercial DNA testing laboratory for breed identification. Whereas DNA breed signatures identified only 25 dogs (21%) as pit bull-type, shelter staff collectively identified 62 (52%) dogs as pit bull-type. Agreement between visual and DNA-based breed assignments varied among individuals, with sensitivity for pit bull-type identification ranging from 33% to 75% and specificity ranging from 52% to 100%. The median kappa value for inter-observer agreement with DNA results at each shelter ranged from 0.1 to 0.48 (poor to moderate). Lack of consistency among shelter staff indicated that visual identification of pit bull-type dogs was unreliable. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. Moving the boundary between wavelength resources in optical packet and circuit integrated ring network.

    Science.gov (United States)

    Furukawa, Hideaki; Miyazawa, Takaya; Wada, Naoya; Harai, Hiroaki

    2014-01-13

    Optical packet and circuit integrated (OPCI) networks provide both optical packet switching (OPS) and optical circuit switching (OCS) links on the same physical infrastructure using a wavelength multiplexing technique in order to deal with best-effort services and quality-guaranteed services. To immediately respond to changes in user demand for OPS and OCS links, OPCI networks should dynamically adjust the amount of wavelength resources for each link. We propose a resource-adjustable hybrid optical packet/circuit switch and transponder. We also verify that distributed control of resource adjustments can be applied to the OPCI ring network testbed we developed. In cooperation with the resource adjustment mechanism and the hybrid switch and transponder, we demonstrate that automatically allocating a shared resource and moving the wavelength resource boundary between OPS and OCS links can be successfully executed, depending on the number of optical paths in use.

  13. Depth preference in released juvenile turbot Psetta maxima

    DEFF Research Database (Denmark)

    Albertsen, Christoffer Moesgaard; Støttrup, Josianne; Nielsen, Anders

    2014-01-01

    Hatchery-reared juvenile turbot Psetta maxima were tagged with Passive Integrated Transponder (PIT) tags and released at three different depths in a sandy bay in Denmark. About 2–7% of the released fish were registered daily to monitor their distribution using a tag antenna mounted on a modified...

  14. Identification of individual foothill yellow-legged frogs (Rana boylii) using chin pattern photographs: a non-invasive and effective method for small population studies

    Science.gov (United States)

    K.R. Marlow; K.D. Wiseman; Clara Wheeler; J.E.  Drennan; R.E.  Jackman

    2016-01-01

    The ability to identify individual animals is a valuable tool in the study of amphibian population dynamics, movement ecology, social behavior, and habitat use. Numerous methods of marking amphibians have been employed including the use of passive integrated transponder (PIT) tags, radio-transmitters, elastomers, branding, and mutilation techniques such as toe...

  15. LEO-to-ground optical communications using SOTA (Small Optical TrAnsponder) - Payload verification results and experiments on space quantum communications

    Science.gov (United States)

    Carrasco-Casado, Alberto; Takenaka, Hideki; Kolev, Dimitar; Munemasa, Yasushi; Kunimori, Hiroo; Suzuki, Kenji; Fuse, Tetsuharu; Kubo-Oka, Toshihiro; Akioka, Maki; Koyama, Yoshisada; Toyoshima, Morio

    2017-10-01

    Free-space optical communications have held the promise of revolutionizing space communications for a long time. The benefits of increasing the bitrate while reducing the volume, mass and energy of the space terminals have attracted the attention of many researchers for a long time. In the last few years, more and more technology demonstrations have been taking place with participants from both the public and the private sector. The National Institute of Information and Communications Technology (NICT) in Japan has a long experience in this field. SOTA (Small Optical TrAnsponder) was the last NICT space lasercom mission, designed to demonstrate the potential of this technology applied to microsatellites. Since the beginning of SOTA mission in 2014, NICT regularly established communication using the Optical Ground Stations (OGS) located in the Headquarters at Koganei (Tokyo) to receive the SOTA signals, with over one hundred successful links. All the goals of the SOTA mission were fulfilled, including up to 10-Mbit/s downlinks using two different wavelengths and apertures, coarse and fine tracking of the OGS beacon, space-to-ground transmission of the on-board-camera images, experiments with different error correcting codes, interoperability with other international OGS, and experiments on quantum communications. The SOTA mission ended on November 2016, more than doubling the designed lifetime of 1-year. In this paper, the SOTA characteristics and basic operation are explained, along with the most relevant technological demonstrations.

  16. Nucleation sites of Ge nanoislands grown on pit-patterned Si substrate prepared by electron-beam lithography

    Science.gov (United States)

    Smagina, Zh. V.; Zinovyev, V. A.; Rudin, S. A.; Novikov, P. L.; Rodyakina, E. E.; Dvurechenskii, A. V.

    2018-04-01

    Regular pit-patterned Si(001) substrates were prepared by electron-beam lithography followed by plasma chemical etching. The geometry of the pits was controlled by varying the etching conditions and the electron-beam exposure duration. It was shown that the location of three-dimensional (3D) Ge nanoislands subsequently grown on the pit-patterned Si substrates depends on the shape of the pit bottom. In the case of pits having a sharp bottom, 3D Ge islands nucleate inside the pits. For pits with a wide flat bottom, the 3D Ge island nucleation takes place at the pit periphery. This effect is attributed to the strain relaxation depending not only on the initial pit shape, but also on its evolution during the Ge wetting layer deposition. It was shown by Monte Carlo simulations that in the case of a pit with a pointed bottom, the relaxation is most effective inside the pit, while for a pit with a wide bottom, the most relaxed area migrates during Ge deposition from the pit bottom to its edges, where 3D Ge islands nucleate.

  17. Flyover Modeling of Planetary Pits - Undergraduate Student Instrument Project

    Science.gov (United States)

    Bhasin, N.; Whittaker, W.

    2015-12-01

    On the surface of the moon and Mars there are hundreds of skylights, which are collapsed holes that are believed to lead to underground caves. This research uses Vision, Inertial, and LIDAR sensors to build a high resolution model of a skylight as a landing vehicle flies overhead. We design and fabricate a pit modeling instrument to accomplish this task, implement software, and demonstrate sensing and modeling capability on a suborbital reusable launch vehicle flying over a simulated pit. Future missions on other planets and moons will explore pits and caves, led by the technology developed by this research. Sensor software utilizes modern graph-based optimization techniques to build 3D models using camera, LIDAR, and inertial data. The modeling performance was validated with a test flyover of a planetary skylight analog structure on the Masten Xombie sRLV. The trajectory profile closely follows that of autonomous planetary powered descent, including translational and rotational dynamics as well as shock and vibration. A hexagonal structure made of shipping containers provides a terrain feature that serves as an appropriate analog for the rim and upper walls of a cylindrical planetary skylight. The skylight analog floor, walls, and rim are modeled in elevation with a 96% coverage rate at 0.25m2 resolution. The inner skylight walls have 5.9cm2 color image resolution and the rims are 6.7cm2 with measurement precision superior to 1m. The multidisciplinary student team included students of all experience levels, with backgrounds in robotics, physics, computer science, systems, mechanical and electrical engineering. The team was commited to authentic scientific experimentation, and defined specific instrument requirements and measurable experiment objectives to verify successful completion.This work was made possible by the NASA Undergraduate Student Instrument Project Educational Flight Opportunity 2013 program. Additional support was provided by the sponsorship of an

  18. Powder-in-Tube (PIT) Nb3Sn conductors for high-field magnets

    NARCIS (Netherlands)

    Lindenhovius, J.H.; Hornsveld, E.M.; den Ouden, A.; Wessel, Wilhelm A.J.; ten Kate, Herman H.J.

    2000-01-01

    New Nb3Sn conductors, based on the powder-in-tube (PIT) process, have been developed for application in accelerator magnets and high-field solenoids. For application in accelerator magnets, SMI has developed a binary 504 filament PIT conductor by optimizing the manufacturing process and adjustment

  19. Decommissioning management of pit water at an uranium mine in Hunan Province

    International Nuclear Information System (INIS)

    Li Renjie

    2002-01-01

    The author introduces the influence of mining on groundwater at an uranium mine in Hunan Province, emphatically discusses the managing principles, methods and research works of pit water in decommissioning, and summaries sealing technique, construction management and the effect achieved in management of pit water

  20. Stochastic approach to pitting-corrosion-extreme modelling in low-carbon steel

    Energy Technology Data Exchange (ETDEWEB)

    Valor, A. [Facultad de Fisica, Universidad de La Habana, San Lazaro y L, Vedado 10400, La Habana (Cuba); Caleyo, F. [Departamento de Ingenieria Metalurgica, IPN-ESIQIE, UPALM Edif. 7, Zacatenco, Mexico DF 07738 (Mexico)], E-mail: fcaleyo@gmail.com; Rivas, D.; Hallen, J.M. [Departamento de Ingenieria Metalurgica, IPN-ESIQIE, UPALM Edif. 7, Zacatenco, Mexico DF 07738 (Mexico)

    2010-03-15

    A stochastic model previously developed by the authors using Markov chains has been improved in the light of new experimental evidence. The new model has been successfully applied to reproduce the time evolution of extreme pitting corrosion depths in low-carbon steel. The model is shown to provide a better physical understanding of the pitting process.

  1. Structural and functional studies on the pituitary-specific transcription factor Pit-1

    NARCIS (Netherlands)

    Augustijn, K.D.

    2002-01-01

    Pit-1 is a pituitary specific transcription factor that plays a central role in the development and maintenance of a number of cell lineages in the anterior pituitary gland. In these cell lineages, Pit-1 is required for the selective expression of the growth hormone (GH), prolactin (PRL) and the

  2. Seedling and Sapling Dynamics of Treefall Pits in Puerto Rico1

    Science.gov (United States)

    Lawrence R. Walker

    2000-01-01

    Seedling and sapling dynamics in a Puerto Rican rain forest were compared between forest understory and soil pits created by the uprooting of 27 trees during Hurricane Hugo. Soil N and P, organic matter, and soil moisture were lower and bulk densities were higher in the disturbed mineral soils of the pits than in undisturbed forest soils ten months after the hurricane...

  3. Rupelian (middle Oligocene) fish otoliths from the clay pit 'De Vlijt' near Winterswijk, The Netherlands

    NARCIS (Netherlands)

    Gaemers, P.A.M.; Hinsbergh, van V.W.M.

    1978-01-01

    A large, interesting otolith fauna from the Middle Oligocene was found in the clay pit 'De Vlijt' near Winterswijk by sifting large quantities of clay and by collecting large loose specimens in the clay pit. Thirty-five species and one subspecies were indentified; nine species are new, viz.

  4. 78 FR 54956 - Agency Information Collection (Open Burn Pit Registry Airborne Hazard Self-Assessment...

    Science.gov (United States)

    2013-09-06

    ...: Open Burn Pit Registry Airborne Hazard Self-Assessment Questionnaire, VA Form 10-10066. Type of Review... services to Open Burn Pit Registry participants and improve VA's ability to understand the health effects... DEPARTMENT OF VETERANS AFFAIRS [OMB Control No. 2900-NEW] Agency Information Collection (Open Burn...

  5. 78 FR 44625 - Proposed Information Collection (Open Burn Pit Registry Airborne Hazard Self-Assessment...

    Science.gov (United States)

    2013-07-24

    ... DEPARTMENT OF VETERANS AFFAIRS Proposed Information Collection (Open Burn Pit Registry Airborne... to ``OMB Control No. 2900--NEW, Open Burn Pit Registry Airborne Hazard Self-Assessment Questionnaire... health effects of service members' exposure to toxic airborne chemicals and fumes caused by open burn...

  6. Preliminary study of realizability of Karazhyra open pit coal fines briquetting

    International Nuclear Information System (INIS)

    Deryavko, I.I.; Perepelkin, I.G.; Chuprunov, K.V.

    2001-01-01

    Main properties of brown coals in Karazhyra open pit upper and lower packs are determined. Characteristics of these coals briquette-ability are evaluated. A conceptual possibility to obtain high-quality briquettes from open pit coal fines is shown. (author)

  7. PREVENTION OF ACID MINE DRAINAGE GENERATION FROM OPEN-PIT MINE HIGHWALLS

    Science.gov (United States)

    Exposed, open pit mine highwalls contribute significantly to the production of acid mine drainage (AMD) thus causing environmental concerns upon closure of an operating mine. Available information on the generation of AMD from open-pit mine highwalls is very limit...

  8. Stochastic approach to pitting-corrosion-extreme modelling in low-carbon steel

    International Nuclear Information System (INIS)

    Valor, A.; Caleyo, F.; Rivas, D.; Hallen, J.M.

    2010-01-01

    A stochastic model previously developed by the authors using Markov chains has been improved in the light of new experimental evidence. The new model has been successfully applied to reproduce the time evolution of extreme pitting corrosion depths in low-carbon steel. The model is shown to provide a better physical understanding of the pitting process.

  9. Variation in xylem structure from tropics to tundra: Evidence from vestured pits

    NARCIS (Netherlands)

    Jansen, S.; Baas, P.; Gasson, P.; Lens, F.; Smets, E.

    2004-01-01

    Bordered pits play an important role in permitting water flow among adjacent tracheary elements in flowering plants. Variation in the bordered pit structure is suggested to be adaptive in optimally balancing the conflict between hydraulic efficiency (conductivity) and safety from air entry at the

  10. Potential Multi-Canister Overpack (MCO) Cask Drop in the K West Basin South Loadout Pit

    International Nuclear Information System (INIS)

    POWERS, T.B.

    1999-01-01

    This calculation note documents the probabilistic calculation of a potential drop of a multi-canister overpack (MCO) cask or MCO cask and immersion pail at the K West Basin south loadout pit. The calculations are in support of the cask loading system (CLS) subproject alignment of CLS equipment in the K West Basin south loadout pit

  11. Cleanup Verification Package for the 126-F-1, 184-F Powerhouse Ash Pit

    International Nuclear Information System (INIS)

    Clark, S.W.; Sulloway, H.M.

    2007-01-01

    This cleanup verification package documents completion of remedial action for the 126-F-1, 184-F Powerhouse Ash Pit. This waste site received coal ash from the 100-F Area coal-fired steam plant. Leakage of process effluent from the 116-F-14 , 107-F Retention Basins flowed south into the ash pit, contaminating the northern portion

  12. Drill and Blast Performance Evaluation at the Obra Pit of Chirano ...

    African Journals Online (AJOL)

    This paper investigates the causes of inefficient fragmentation and formation of toes in the Obra pit of Chirano Gold Mines Ltd and recommends best practices in order to produce optimum fragmentation to feed the crusher at a reduced cost and to provide good working pit floors. The methods employed included: drilling ...

  13. Micromorphology and systematic distribution of pit membrane thickenings in Oleaceae: Tori and pseudo-tori

    NARCIS (Netherlands)

    Rabaey, D.; Huysmans, S.; Lens, F.; Smets, E.; Jansen, S.

    2008-01-01

    Recent studies on the functional significance of pit membranes in water conducting cells have renewed general interest in their micromorphology. At least two types of pit membrane thickenings have been described in angiosperm families, i.e. genuine tori and pseudo-tori. This study explores the

  14. Pitting Corrosion Behavior of 304 SS and 316 SS Alloys in Aqueous Chloride and Bromide Solutions

    Directory of Open Access Journals (Sweden)

    Ibtehal Kareem Shakir

    2018-01-01

    Full Text Available The importance of the present work falls on the pitting corrosion behavior investigation of 304 SS and 316 SS alloys in 3.5 wt% of aqueous solution bearing with chloride and bromide anion at different solutions temperature range starting from (20-50oC due to the pitting corrosion tremendous effect on the economic, safety and materials loss due to leakage. The impact of solution temperatures on the pitting corrosion resistance at 3.5wt% (NaCl and NaBr solutions for the 304 SS and 316 SS has been investigated utilizing the cyclic polarization techniques at the potential range -400 to1000 mV vs. SCE at 40 mV/sec scan rate followed by the surface characterization employing Scanning Electron Microscope. The results show that a significant decline in the pitting corrosion potential Ep values of both stainless steel alloys in chloride and bromide solution during temperature increase attributed to the pitting corrosion potential decreased arises from the modification of the passive film properties. The surface examination using optical microscope and scanning electron microscope prove the occurring of higher pitting density over 304 SS in chloride solution than that observed in bromide solution with a non-circular lacy cover pitfall out at the center and falls inside the pits hall in comparison to the isolated circular lacy cover pit formed on 316 SS in 3.5wt% NaBr solution at 50 oC.

  15. A New Algorithm for Determining Ultimate Pit Limits Based on Network Optimization

    Directory of Open Access Journals (Sweden)

    Ali Asghar Khodayari

    2013-12-01

    Full Text Available One of the main concerns of the mining industry is to determine ultimate pit limits. Final pit is a collection of blocks, which can be removed with maximum profit while following restrictions on the slope of the mine’s walls. The size, location and final shape of an open-pit are very important in designing the location of waste dumps, stockpiles, processing plants, access roads and other surface facilities as well as in developing a production program. There are numerous methods for designing ultimate pit limits. Some of these methods, such as floating cone algorithm, are heuristic and do not guarantee to generate optimum pit limits. Other methods, like Lerchs–Grossmann algorithm, are rigorous and always generate the true optimum pit limits. In this paper, a new rigorous algorithm is introduced. The main logic in this method is that only positive blocks, which can pay costs of their overlying non-positive blocks, are able to appear in the final pit. Those costs may be paid either by positive block itself or jointly with other positive blocks, which have the same overlying negative blocks. This logic is formulated using a network model as a Linear Programming (LP problem. This algorithm can be applied to two- and three-dimension block models. Since there are many commercial programs available for solving LP problems, pit limits in large block models can be determined easily by using this method.

  16. Management of Pit 9 - highlights of accomplishments and lessons learned to date

    International Nuclear Information System (INIS)

    Schwartz, F.G.

    1995-01-01

    The Pit 9 project is a U.S. Department of Energy prototype full scale demonstration to retrieve and treat buried mixed transuranic waste. The project is being managed by the DOE-Idaho Environmental Restoration Program, in conjunction with the Environmental Protection Agency Region 10 and the state of Idaho, under the Idaho National Engineering Laboratory Federal Facility Agreement and Consent Order. Pit 9 is located in the northeast corner of the Subsurface Disposal Area (SDA) of the Radioactive Waste Management Complex (RWMC) at the Idaho National Engineering Laboratory (INEL). The Pit 9 project was conceived out of the need to determine capabilities to cost effectively retrieve and treat buried radioactive and radioactive mixed waste, and obtain characterization and contaminant migration data for buried waste at the INEL. Waste was disposed in Pit 9 from November 1967 to June 1969. Pit 9, at about 380 feet by 125 feet, represents approximately one acre of surface area of the 88 acre SDA. The pit contains approximately 350,000 ft 3 of soil beneath and between the buried waste and about 250,000 ft 3 of overburden soil. The average depth of the pit from soil surface to bedrock is approximately 17.5 feet. Approximately 110,000 ft 3 of transuranic (TRU) contaminated mixed wastes from Rocky Flats and approximately 40,000 ft 3 of low level and mixed wastes from the INEL were buried in Pit 9 during this period. Pit 9 is estimated to contain over 30,000 gallons of organics (over 30% of the total organic inventory in the SDA) and approximately 66 pounds of TRU radionuclides (between 3% and 4% of the total TRU inventory in the SDA). Pit 9 was selected as a demonstration site because it was one of the last disposal pits at the INEL to receive Rocky Flats waste, disposal records are better for Pit 9 than for disposal pits and trenches from earlier points in time, and the wastes in Pit 9 are representative of the wastes disposed in the SDA

  17. Pit initiation resistance of ferritic stainless steels in chloride environments from 800 to 2600C

    International Nuclear Information System (INIS)

    Cieslak, W.R.; Duquette, D.J.

    1983-01-01

    The pitting resistance of high-purity ferritic stainless steels has been studied by potentiodynamic anodic polarization, mechanical film-rupture (scratch) testing, and microstructural examination. The purpose has been to determine the ability of the Fe-Cr-Mo alloys to resist pit initiation at temperatures up to 260 0 C in chloride environments. At temperatures exceeding about 200 0 C, Cr is shown to become much more effective than Mo to enhance alloy pitting resistance. In fact, at 260 0 C, 2% Mo does not noticeably affect the pitting resistance of 18% Cr or 28% Cr steels. Also, 5% Mo is more effective for the lower Cr than for the higher Cr alloy, unlike lower temperatures, at which the effect of the two elements is greater than additive. Preferential localized attack at microstructural features, e.g. inclusions, is not observed under any of the experimental conditions, rather the pit-initiation resistance is controlled solely by alloy composition

  18. Simulation of Fatigue Crack Initiation at Corrosion Pits With EDM Notches

    Science.gov (United States)

    Smith, Stephen W.; Newman, John A.; Piascik, Robert S.

    2003-01-01

    Uniaxial fatigue tests were conducted to compare the fatigue life of laboratory produced corrosion pits, similar to those observed in the shuttle main landing gear wheel bolt-hole, and an electro-discharged-machined (EDM) flaw. EDM Jaws are used to simulate corrosion pits during shuttle wheel (dynamometer) testing. The aluminum alloy, (AA 7050) laboratory fatigue tests were conducted to simulate the local stress level contained in the wheel bolt-hole. Under this high local stress condition, the EDM notch produced a fatigue life similar to test specimens containing corrosion pits of similar size. Based on the laboratory fatigue test results, the EDM Jaw (semi-circular disc shaped) produces a local stress state similar to corrosion pits and can be used to simulate a corrosion pit during the shuttle wheel dynamometer tests.

  19. Non Destructive Testing Measurement for Monitoring Pitting Corrosion using Dcp Techniques

    International Nuclear Information System (INIS)

    Atlam, A.; Omar, A.A.; Habashy, M.; Waheed, A.F.; Shafy, M.

    2010-01-01

    A repeatable monitoring of pit from in accessible side of a welded side of a structure is one of the hurdles in field of NT. The present work uses the DC potential drop measuring system for evaluating the response of pits in the weld joins to be detected by DC potential drop measurements. Weld joint of type 304L stainless steel welded with 308L was tested. Selected pits in different zones of the weld joint were detected by optical microscopy. The PD test shows difference in potential between pitted and non-pitted weld joints ranging from 1.3 in BM to 1.7 in HAZ. The capability of present monitoring process can be extended to evaluate the reduction in thickness for the case of thick stainless steel structure

  20. Influence of cracks and pitting corrosion on residual ultimate strength of stiffened plates

    Directory of Open Access Journals (Sweden)

    ZHANG Jing

    2018-02-01

    Full Text Available [Objectives] Ships and offshore platforms serve in the harsh sea environment for a long time. Cracks and pitting corrosion will occur in such a structure and the damage will affect its ultimate strength.[Methods] To investigate the influence of cracks and pitting corrosion on ultimate bearing capacity, the ultimate strength of a structure under axial compression is studied by using a nonlinear finite element. The mesh size of a stiffened plate with cracks and pitting corrosion is first discussed. Then the influence of the relative positions of cracks and pitting corrosion, number of corrosion points and crack length impact on the residual ultimate strength of damaged stiffened plates is discussed via a series of calculations.[Results] The results indicate that the increase in crack length and pitting corrosion significantly decreases the ultimate strength of a stiffened plate. [Conclusions] This provides a useful reference for designing and maintaining ships and offshore structures in their life cycles.

  1. Annealing to Mitigate Pitting in Electropolished Niobium Coupons and SRF Cavities

    Energy Technology Data Exchange (ETDEWEB)

    Cooley, L.D.; Hahn, E.; Hicks, D.; Romanenko, A.; Schuessler, R.; Thompson, C.; /Fermilab

    2011-06-08

    Ongoing studies at Fermilab investigate whether dislocations and other factors instigate pitting during cavity electropolishing (EP), despite careful processing controls and the inherent leveling mechanism of EP itself. Here, cold-worked niobium coupons, which exhibited increased tendencies for pitting in our past study, were annealed in a high vacuum furnace and subsequently processed by EP. Laser confocal scanning microscopy and special defect counting algorithms were used to assess the population of pits formed. Hardness measurements indicated that annealing for 2 hours at 800 C produced recovery, whereas annealing for 12 hours at 600 C did not, as is consistent with known changes for cavities annealed in a similar way. The 800 C anneal was effective in some cases but not others, and we discuss reasons why tendencies for pitting remain. We discuss implications for cavities and continued work to understand pitting.

  2. The effect of notches and pits on corrosion fatigue strength

    Science.gov (United States)

    Tatner, Ian

    An investigation has been undertaken to examine the fatigue behaviour of two martensitic steels in air and aggressive environments. The steels studied are, 18% Ni marageing steel and FV520B, the later being a stainless steel turbine blade material and the former being a marageing steel that suffers general corrosion in mild environments. Both steels were heat treated to give similar tensile strength.The design and manufacture of an autoclave allowed push-pull fatigue tests to be conducted in aggressive environments at elevated temperatures.Corrosion potential was monitored using a three electrode cell and was controlled during testing. Base-line fatigue tests were conducted with a range of constant corrosion potentials, using both notched and plain FV520B specimens. In addition fatigue tests with pulsed corrosion potential were performed to asses the effect of transient corrosion conditions on the corrosion fatigue strength. The pulsed tests were designed to simulate service transients in the oxygen content and general chemical hostility in the condensing steam environment during start-up and shut down of the steam turbine.Post test examination of fractured samples was performed using Scanning Electron Microscopy (SEM) and optical microscope techniques. The fractography results were used to quantify microstructural and fracture features of the steels.A model based on the size and geometry of the initial corrosion pitting has been proposed to asses the fatigue life of FV520B in an aggressive environment.The effect of pitting on the corrosion fatigue strength of FV520B has been modelled using linear elastic fracture mechanics (LEFM) type approach. The model has shown a good correlation between predicted fatigue lives with experimental results.The results suggest that the fatigue life is governed by the mechanical stress concentrating effect of the pits rather than the electrochemical damage caused by the environment.Finite Element Analysis (FEA) of the notch allowed

  3. Open-pit production and control at Roessing

    International Nuclear Information System (INIS)

    Hodson, D.; Rich, C.

    1986-01-01

    In recent years metal prices have been severely depressed and most companies have directed efforts to controlling costs in order to stay in business. Roessing Uranium has consistently kept uranium production cost increases well below the domestic inflation rate and this has been the result of a firm commitment to production and cost control, which is the main theme of this paper. The subject of cost analysis is briefly presented and the paper then gives more technical detail under the main headings of grade control, production control and engineering projects. The main communication channels, which are used to ensure that different departments on the mine are all working for the same objectives, are mentioned. The paper, however, is intended to be a general overview of the engineering aspects of open-pit cost control

  4. Equipment size effects on open pit mining performance

    Energy Technology Data Exchange (ETDEWEB)

    A. Bozorgebrahimi; R.A. Hall; M.A. Morin [University of British Columbia, Vancouver, BC (Canada). Mining Engineering Department

    2005-03-01

    This paper discusses the exploitation of economies of scale in open pit mining through the use of increasingly larger equipment. It presents a method adopted to evaluate the impact of increased scale on operational performance factors. The work identifies equipment size sensitive variables (ESSVs) in the mine design process that affect the performance of the production process. Data from a set of case studies show that the ESSV influence extends beyond mine production to encompass milling performance, environmental footprint and community impacts. Some ESSVs (such as reliability, tyre costs and productivity) are shown to be related to the current state of equipment technology and their effects are therefore comparable for different mines. Other ESSVs relate to the mine and deposit characteristics; their effects therefore vary from mine to mine. A detailed analytical approach, developed to model the impact of ESSVs, suggests that for truck/shovel operations, the industry may be approaching a situation of diseconomies of scale.

  5. IP and resistivity survey at the INEL cold test pit

    International Nuclear Information System (INIS)

    Frangos, W.

    1997-01-01

    Induced polarization (IP) is a technique for detection of diffuse occurrences of metallic material. The Idaho National Laboratory (INEL) Cold Test Pit (CTP) has been carefully constructed to simulate stored hazardous waste occurrences. IP and resistivity surveys of the CTP show a very strong IP response and a modest resistivity response associated with the simulated waste. Several false positive resistivity anomalies are noted. 2-D inversion of the data accurately determine the lateral limits of the waste zone. The depth of burial indicated is deeper than reported by the construction engineers. Limited depth extent is recognized, in distinction to results from other, resistivity-based, methods, but it also appears too deep. IP holds promise as a method for locating buried waste

  6. CMP [Chemicals, Metals, and Pesticides] Pits: Environmental information document

    International Nuclear Information System (INIS)

    Scott, S.C.; Kolb, N.L.; Price, V.; Bledsoe, H.W.

    1986-12-01

    This document provides environmental information on postulated closure options for the Chemicals, Metals, and Pesticides (CMP) Pits at the Savannah River Plant and was developed as background technical documentation for the Department of Energy's proposed Environmental Impact Statement (EIS) on waste management activities for groundwater protection at the plant. The results of groundwater and atmospheric pathway analyses, accident analysis, and other environmental assessments discussed in this document are based upon a conservative analysis of all foreseeable scenarios as defined by the National Environmental Policy Act (40 CFR 1500-1508). The scenarios do not necessarily represent actual environmental conditions. This document is not meant to be used as a regulatory closure plan or other regulatory document to comply with required federal or state environmental regulations

  7. Remedial Action Work Plan Amchitka Island Mud Pit Closures

    Energy Technology Data Exchange (ETDEWEB)

    DOE/NV

    2001-04-05

    This remedial action work plan presents the project organization and construction procedures developed for the performance of the remedial actions at U.S. Department of Energy (DOE's) sites on Amchitka Island, Alaska. During the late1960s and early 1970s, the U.S. Department of Defense and the U.S. Atomic Energy Commission (the predecessor agency to DOE) used Amchitka Island as a site for underground nuclear tests. A total of nine sites on the Island were considered for nuclear testing; however, tests were only conducted at three sites (i.e., Long Shot in 1965, Milrow in 1969, and Cannikin in 1971). In addition to these three sites, large diameter emplacement holes were drilled in two other locations (Sites D and F) and an exploratory hole was in a third location (Site E). It was estimated that approximately 195 acres were disturbed by drilling or preparation for drilling in conjunction with these activities. The disturbed areas include access roads, spoil-disposal areas, mud pits which have impacted the environment, and an underground storage tank at the hot mix plant which was used to support asphalt-paving operations on the island. The remedial action objective for Amchitka Island is to eliminate human and ecological exposure to contaminants by capping drilling mud pits, removing the tank contents, and closing the tank in place. The remedial actions will meet State of Alaska regulations, U.S. Fish and Wildlife Service refuge management goals, address stakeholder concerns, and address the cultural beliefs and practices of the native people. The U.S. Department of Energy, Nevada Operations Office will conduct work on Amchitka Island under the authority of the Comprehensive Emergency Response, Compensation, and Liability Act. Field activities are scheduled to take place May through September 2001. The results of these activities will be presented in a subsequent Closure Report.

  8. Gas cylinder disposal pit remediation waste minimization and management

    International Nuclear Information System (INIS)

    Alas, C.A.; Solow, A.; Criswell, C.W.; Spengler, D.; Brannon, R.; Schwender, J.M.; Eckman, C.K.; Rusthoven, T.

    1995-01-01

    A remediation of a gas cylinder disposal pit at Sandia National Laboratories, New Mexico has recently been completed. The cleanup prevented possible spontaneous releases of hazardous gases from corroded cylinders that may have affected nearby active test areas at Sandia's Technical Area III. Special waste management, safety, and quality plans were developed and strictly implemented for this project. The project was conceived from a waste management perspective, and waste minimization and management were built into the planning and implementation phases. The site layout was planned to accommodate light and heavy equipment, storage of large quantities of suspect soil, and special areas to stage and treat gases and reactive chemicals removed from the pit, as well as radiation protection areas. Excavation was a tightly controlled activity using experienced gas cylinder and reactive chemical specialists. Hazardous operations were conducted at night under lights, to allow nearby daytime operations to function unhindered. The quality assurance plan provided specific control of, and documentation for, critical decisions, as well as the record of daily operations. Both hand and heavy equipment excavation techniques were utilized. Hand excavation techniques were utilized. Hand excavation techniques allows sealed glass containers to be exhumed unharmed. In the end, several dozen thermal batteries; 5 pounds (2.3 kg) of lithium metal; 6.6 pounds (3.0 kg) of rubidium metal; several kilograms of unknown chemicals; 140 cubic yards (107 cubic meters) of thorium-contaminated soil; 270 cubic yards (205 cubic meters) of chromium-contaminated soil; and 450 gas cylinders, including 97 intact cylinders containing inert, flammable, toxic, corrosive, or oxidizing gases were removed and effectively managed to minimize waste

  9. Decontamination and decommissioning of the SPERT-I seepage pit at the Idaho National Engineering Laboratory. Final report

    International Nuclear Information System (INIS)

    Suckel, R.A.

    1984-11-01

    This report describes the decontamination and decommissioning of the SPERT-I seepage pit. Prior to its decontamination and decommissioning, the seepage pit was surrounded by an earthen dike varying from 2 to 6 ft above the pit bottom. A 6-in., cast iron, underground waste line originated at the pit tank in the reactor building and ran approximately 68 ft to the seepage pit. The soil in the seepage pit contained low-level radioactive contamination. The soil surface was removed to a depth of 2.5 ft and shipped to the Radioactive Waste Management Complex (RWMC). The waste line that contained fixed contamination was removed and also sent to the RWMC. The pit was backfilled with radiologically clean soil, reducing the surface activity to background. A permanent marker was erected over the backfilled pit to indicate that presence of residual subsurface radioactive contamination. 5 references, 26 figures, 3 tables

  10. Central Shops Burning/Rubble Pit 631-6G Additional Sampling and Monitor Well Installation Report

    International Nuclear Information System (INIS)

    Palmer, E.

    1995-02-01

    The Central Shops Burning/Rubble Pit 631-6G was constructed in 1951 as an unlined earthen pit in surficial sediments for disposal and incineration of potentially hazardous substances, such as metals and organic solvents

  11. Effect of heat treatment on pitting corrosion of austenitic Cr-Ni-Mo steels in sodium chloride solution

    International Nuclear Information System (INIS)

    Stefec, R.; Franz, F.; Holecek, A.

    1979-01-01

    The pitting corrosion resistance of Cr17Ni12Mo2,5 type steel under potentiostatic polarization in a sodium chloride solution is adversely affected by previous annealing. The data obtained were systematically dependent on annealing temperature, time and surface roughness. The corrosion current, the number of pits or the mean area of pit opening and the corrosion rate within the pits were increased by previous annealing at 550 to 750 0 C for 1-100 hrs. The highest corrosion rate estimated corresponded to heat treatments provoking severe sensitization to intergranular corrosion. The paercentage area of corrosion pit openings and the estimated pit penetration rates were several times higher for as-machined than for polished surfaces. It can be assumed that pitting corrosion is little affected by the carbon content and that molybdenum depletion of grain-boundary zones is responsible for the reduced pitting resistance of annealed steels. (orig./HP) [de

  12. Fish assemblages in borrow-pit lakes of the Lower Mississippi River

    Science.gov (United States)

    Miranda, Leandro E.; Killgore, K. J.; Hoover, J.J.

    2013-01-01

    Borrow-pit lakes encompass about a third of the lentic water habitats (by area) in the active floodplain of the Lower Mississippi River, yet little is known about their fish assemblages. We investigated whether fish assemblages supported by borrow-pit lakes resembled those in oxbow lakes to help place the ecological relevance of borrow-pit lakes in context with that of natural floodplain lakes. In all, we collected 75 fish species, including 65 species in eight borrow-pit lakes, 52 species in four riverside oxbow lakes, and 44 species in eight landside oxbow lakes. Significant differences in several species richness metrics were evident between borrow-pit lakes and landside oxbow lakes but not between borrow-pit lakes and riverside oxbow lakes. All three lake types differed in fish assemblage composition. Borrow-pit lakes and riverside oxbow lakes tended to include a greater representation of fish species that require access to diverse environments, including lentic, lotic, and palustrine habitats; fish assemblages in landside oxbow lakes included a higher representation of lacustrine species. None of the fish species collected in borrow-pit lakes was federally listed as threatened or endangered, but several were listed as species of special concern by state governments in the region, suggesting that borrow-pit lakes provide habitat for sensitive riverine and wetland fish species. Differences in fish assemblages among borrow-pit lakes were linked to engineered morphologic features, suggesting that diversity in engineering can contribute to diversity in fish assemblages; however, more research is needed to match engineering designs with fish assemblage structures that best meet conservation needs.

  13. Project W-314 acceptance test report HNF-4647 for HNF-4646 241-B pit leak detection ANB-WT-LDSTA-231 for project W-314

    International Nuclear Information System (INIS)

    HAMMERS, J.S.

    1999-01-01

    The purpose of the test was to verify that the AN Tank Farm B Pit Leak Detector components are functionally integrated and operate in accordance with engineering design specifications. The Acceptance Test Procedure HNF-4646,241-AN-B-Pit Leak Detection ANB-WT-LDSTA-231 was conducted between 26 June and 02 July 1999 at the 200E AN Tank Farm. The test has been completed with no open test exceptions. The test was conducted prior to final engineering ''as built'' activities being completed this had no impact on the procedure or test results. All components, identified in the procedure were found to be labeled and identified as written in the procedure

  14. 76 FR 12096 - McCloud-Pit Project; Notice of Availability of the Final Environmental Impact Statement for the...

    Science.gov (United States)

    2011-03-04

    ... Project; Notice of Availability of the Final Environmental Impact Statement for the Mccloud-Pit... Pit Rivers in Shasta County, California and has prepared a final environmental impact statement (EIS... and the alternatives for relicensing the McCloud-Pit Project. The final EIS documents the views of...

  15. ChIP-PIT: Enhancing the Analysis of ChIP-Seq Data Using Convex-Relaxed Pair-Wise Interaction Tensor Decomposition.

    Science.gov (United States)

    Zhu, Lin; Guo, Wei-Li; Deng, Su-Ping; Huang, De-Shuang

    2016-01-01

    In recent years, thanks to the efforts of individual scientists and research consortiums, a huge amount of chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq) experimental data have been accumulated. Instead of investigating them independently, several recent studies have convincingly demonstrated that a wealth of scientific insights can be gained by integrative analysis of these ChIP-seq data. However, when used for the purpose of integrative analysis, a serious drawback of current ChIP-seq technique is that it is still expensive and time-consuming to generate ChIP-seq datasets of high standard. Most researchers are therefore unable to obtain complete ChIP-seq data for several TFs in a wide variety of cell lines, which considerably limits the understanding of transcriptional regulation pattern. In this paper, we propose a novel method called ChIP-PIT to overcome the aforementioned limitation. In ChIP-PIT, ChIP-seq data corresponding to a diverse collection of cell types, TFs and genes are fused together using the three-mode pair-wise interaction tensor (PIT) model, and the prediction of unperformed ChIP-seq experimental results is formulated as a tensor completion problem. Computationally, we propose efficient first-order method based on extensions of coordinate descent method to learn the optimal solution of ChIP-PIT, which makes it particularly suitable for the analysis of massive scale ChIP-seq data. Experimental evaluation the ENCODE data illustrate the usefulness of the proposed model.

  16. Pitting growth rate in carbon steel exposed to simulated radioactive waste

    International Nuclear Information System (INIS)

    Zapp, P.E.

    1995-01-01

    Dilute high-level radioactive waste slurries can induce pitting corrosion in carbon steel tanks in which such waste is stored and processed. The waste is normally maintained with closely monitored nitrite and hydroxide concentrations known to prevent the initiation of pitting. Coupon immersion are being conducted in laboratory simulants of waste to determine the probability and growth rate of pitting in steel in the event of below-limits nitrite concentrations. Sets of about 36 carbon steel coupons have been immersed in known corrosive conditions (nitrite < 5% of the established limit) at a temperature of 50 C. Three sets have been removed from testing after 64, 150, and 350 days of immersion. The long immersion times introduced variability in the exposure conditions due to the evaporation and replenishment of solution. The deepest corrosive attack was measured one each coupon by optical microscopy. The deepest pits were ranked and analyzed as a type 1 extreme value distribution to extrapolate from the coupon population to the maximum pit depths in a waste tank structure. The data were compared to a power law for pit growth, although the deepest pits did not increase monotonically with time in the limited data set

  17. Pitting Corrosion of Ni3(Si,Ti+2Cr Intermetallic Compound at Various Chloride Concentrations

    Directory of Open Access Journals (Sweden)

    Gadang Priyotomo

    2014-05-01

    Full Text Available The pitting corrosion of Ni3(Si,Ti with 2 at% Cr containing two regions of a Ni3(Si,Ti single-phase of L12 structure and a mixture phase of of (L12 +Niss was investigated as function of chloride concentrations by using a polarization method, scanning electron microscope and energy dispersive X-Ray spectroscopy in neutral sodium chloride solutions at 293 K.  The pitting corrosion of Ni3(Si,Ti with and without the addition of aluminium and type C276 alloy were also studied under the same experimental condition for the comparison.  The pitting potential obtained for the Ni3(Si,Ti with 2 at% Cr decreased with increasing chloride concentration.  The specific pitting potentials and the pitting potentials were decreased in the order of C276 alloy > Ni3(Si,Ti > Ni3(Si,Ti + 2Cr > Ni3(Si,Ti + 4Al, which means that the pitting corrosion resistance of Ni3(Si,Ti with 2 at% Cr was higher than Ni3(Si,Ti with 4 at% Al, but lower than that of Ni3(Si,Ti.  A critical chloride concentration of Ni3(Si,Ti with 2 at% Cr was found to be higher than that of Ni3(Si,Ti with at% Al. In addition, the presence of high concentration for oxygen indicates the occurrence of pit formation.

  18. A numerical study of under-deposit pitting corrosion in sour petroleum pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Z.; Sand, K.W.; Teevens, P.J. [Broadsword Corrosion Engineering Ltd., Calgary, AB (Canada)

    2010-07-01

    Insufficient fluid velocity in petroleum pipelines can lead to the deposit of sand, corrosion products, and non-corrosion products on the pipe's metal surface, which in turn can lead to pitting corrosion. There is currently no reliable means of detecting and preventing the pitting process. This paper presented a computerized simulation tool that used the finite element method to model mass transfer-governed internal pitting corrosion under solids deposition in sour petroleum pipelines. The computational domain consisted of a hemispherical pit and a thin stagnant solution film under a surface deposit. The moving mesh method was used to track pitting growth. A Poisson equation was used to determine aqueous path migration of ions. Pitting corrosion rates were estimated using the Nernst-Planck equation. The model was used to predict the effects of different operating parameters on pitting corrosion rates. The model can be used to develop pigging and in-line-inspection (ILI) procedures. 35 refs., 2 tabs., 16 figs.

  19. Pitting growth rate in carbon steel exposed to simulated radioactive waste

    International Nuclear Information System (INIS)

    Zapp, P.E.

    1996-06-01

    Dilute high-level radioactive waste slurries can induce pitting corrosion in carbon steel tanks in which such waste is stored and processed. The waste is normally maintained with closely monitored nitrite and hydroxide concentrations known to prevent the initiation of pitting. Coupon immersion tests are being conducted in laboratory simulants of waste to determine the probability and growth rate of pitting in steel in the event of out-of-limits nitrite concentrations. Sets of about 36 carbon steel coupons have been immersed in known corrosive conditions (nitrite < 5 per cent of the established limit) at a temperature of 50 degrees C. Three sets have been removed from testing after 64, 150, and 350 days of immersion. The long immersion times introduced variability in the exposure conditions due to the evaporation and replenishment of solution. The deepest corrosive attack was measured on each coupon by optical microscopy. The deepest pits were ranked and analyzed as a type 1 extreme value distribution to extrapolate from the coupon population to the maximum expected pit depths in a waste tank structure. The data were compared to a power law for pit growth, although the deepest pits did not increase monotonically with time in the limited data set

  20. Optimizing the physical conditioning of the NASCAR sprint cup pit crew athlete.

    Science.gov (United States)

    Ferguson, David P; Davis, Adam M; Lightfoot, J Timothy

    2015-03-01

    Stock car racing is the largest spectator sport in the United States. As a result, National Association for Stock Car Automobile Racing (NASCAR) Sprint Cup teams have begun to invest in strength and conditioning programs for their pit crew athletes. However, there is limited knowledge regarding the physical characteristics of elite NASCAR pit crew athletes, how the NASCAR Sprint Cup season affects basic physiological parameters such as body composition, and what is the most appropriate physical training program that meets the needs of a pit crew athlete. We conducted 3 experiments involving Sprint Cup motorsport athletes to determine predictors of success at the elite level, seasonal physiological changes, and appropriate physical training programs. Our results showed that hamstring flexibility (p = 0.015) and the score on the 2-tire front run test (p = 0.012) were significant predictors of NASCAR Sprint Cup Pit Crew athlete performance. Additionally, during the off season, pit crew athletes lost lean body mass, which did not return until the middle of the season. Therefore, a strength and conditioning program was developed to optimize pit crew athlete performance throughout the season. Implementation of this strength and conditioning program in 1 NASCAR Sprint Cup team demonstrated that pit crew athletes were able to prevent lean body mass loss and have increased muscle power output from the start of the season to the end of the season.

  1. Inspecting a research reactor's control rod surface for pitting using a machine vision

    International Nuclear Information System (INIS)

    Tokuhiro, Akira T.; Vadakattu, Shreekanth

    2005-01-01

    Inspection for pits on the control rod is performed to study the degradation of the control rod material which helps estimating the service life of the control rod at UMR nuclear reactor (UMRR). This inspection task is visually inspected and recorded subjectively. The conventional visual inspection to identify pits on the control rod surface can be automated using machine vision technique. Since the in-service control rods were not available to capture images and measure number of pits and size of the pits, the applicability of machine vision method was applied on SAE 1018 steel coupons immersed in oxygen saturated de-ionized water at 30deg, 50deg and 70deg. Images were captured after each test cycle at different light intensity to reveal surface topography of the coupon surface and analyzed for number of pits and pit size using EPIX XCAP-Std software. The captured and analyzed images provided quantitative results for the steel coupons and demonstrated that the method can be applied for identifying pits on control rod surface in place of conventional visual inspection. (author)

  2. Initiation and inhibition of pitting corrosion on reinforcing steel under natural corrosion conditions

    Energy Technology Data Exchange (ETDEWEB)

    Abd El Wanees, S., E-mail: s_wanees@yahoo.com [Chemistry Department, Faculty of Science, University of Tabuk, Tabuk (Saudi Arabia); Chemistry Department, Faculty of Science, Zagazig University, Zagazig 44519 (Egypt); Bahgat Radwan, A. [Center for Advanced Materials, Qatar University, Doha 2713 (Qatar); Alsharif, M.A. [Chemistry Department, Faculty of Science, University of Tabuk, Tabuk (Saudi Arabia); Abd El Haleem, S.M. [Chemistry Department, Faculty of Science, Zagazig University, Zagazig 44519 (Egypt)

    2017-04-01

    Initiation and inhibition of pitting corrosion on reinforcing steel in saturated, naturally aerated Ca(OH){sub 2} solutions, under natural corrosion conditions, are followed through measurements of corrosion current, electrochemical impedance spectroscopy and SEM investigation. Induction period for pit initiation and limiting corrosion current for pit propagation are found to depend on aggressive salt anion and cation-types, as well as, concentration. Ammonium chlorides and sulfates are more corrosive than the corresponding sodium salts. Benzotriazole and two of its derivatives are found to be good inhibitors for pitting corrosion of reinforcing steel. Adsorption of these compounds follows a Langmuir adsorption isotherm. The thermodynamic functions ΔE{sup ∗}, ΔH{sup ∗} and ΔS{sup ∗} for pitting corrosion processes in the absence and presence of inhibitor are calculated and discussed. - Highlights: • Cl{sup −} and SO{sub 4} {sup 2-} induce pitting corrosion on passive reinforcing steel. • Initiation and propagation of pitting depend on cation and anion types. • Inhibition is based on adsorption according to Langmuir isotherm.

  3. Pitting Corrosion of Ni3(Si,Ti+4Al Intermetallic Compound at Various Chloride Concentrations

    Directory of Open Access Journals (Sweden)

    Gadang Priyotomo

    2014-04-01

    Full Text Available The pitting corrosion of Ni3(Si,Ti with 4 at% Al consisting of two regions of a Ni3(Si,Ti single-phase of L12 structure and two phases of L12 and fcc Niss was investigated as function of chloride concentrations by using electrochemical method, scanning electron microscope and energy dispersive X-Ray spectroscopy in neutral sodium chloride solutions at 293 K.  In addition, the pitting corrosion of Ni3(Si,Ti and  type C276 alloy were also studied under the same experimental condition for comparison.  The pitting potential obtained for the Ni3(Si,Ti with 4 at%Al decreased with increasing chloride concentration.  The specific pitting potential and pitting potential of Ni3(Si,Ti with 4at%, Ni3(Si,Ti and C276 were the lowest, the moderate and the highest, respectively, which means that the pitting corrosion resistance of Ni3(Si,Ti was higher than Ni3(Si,Ti with 4at% Al, but lower than that of C276.  A critical chloride concentration of Ni3(Si,Ti with 4at% Al was found to be lower than that of Ni3(Si,Ti.  The Pitting corrosion of Ni3(Si,Ti with 4at% Al occurred in the two phase mixture (L12 + Niss.

  4. Application of spectral analysis of the electrochemical noise to the investigation of aluminium alloy pitting corrosion

    International Nuclear Information System (INIS)

    Bataillon, Christian

    1987-01-01

    The objective of this research is to decode (at least partially) the nature of the information contained in the electrochemical noise associated with the pitting corrosion phenomenon in aluminium alloys. After a general presentation of aluminium and its alloys and a report of a bibliographical study on the electrochemical noise, the author gives an overview of a theoretical approach of stochastic phenomena, and of an experimental approach. Then, the experimental investigation of the electrochemical noise in the case of pitting corrosion leads to a noise control law, to a study of the structure of pitting growth, and to the elaboration of a procedure of assessment of spectral characteristics of this noise. The author reports a systematic study of the electrochemical noise with respect to the parameters of the control law. Results allow a quantitative characterization of pitting corrosion resistance of the studied alloys, notably by using the kinetic aspect of pitting growth and the structure of pitting corrosion. The author discusses the physicochemical nature of random fluctuations which build up the noise. He proposes a more precise explanation of phenomena related to initiation and propagation of pitting corrosion on aluminium alloys in marine environment [fr

  5. Critical pitting temperature for Type 254 SMO stainless steel in chloride solutions

    International Nuclear Information System (INIS)

    Abd El Meguid, E.A.; Abd El Latif, A.A.

    2007-01-01

    The variation with time of the open circuit potential of high molybdenum containing stainless steel (Type 254 SMO) was measured in 4% sodium chloride solution in the temperatures range 30-100 deg. C. The plot of steady state potentials as function of temperature showed an inflection at 50 deg. C, attributed to the decrease of oxygen solubility in test solution above 50 deg. C. Potentiodynamic cycling anodic polarization technique was used to determine the critical pitting potential (E pit ) and the critical protection potential (E prot ) of the steel in 4-30% NaCl solutions at temperatures between 30 and 100 deg. C. By plotting the two values versus solution temperature, the corresponding critical pitting (CPT) and the critical protection (CPrT) temperatures were determined. Both parameters decreased with increasing chloride content. Above the CPT, E pit and E prot decreased linearly with log[Cl - ]. The addition of bromide ions to the solution shifted both E pit and E prot towards positive values. In 4% NaCl, E pit increased linearly with pH in the range 1-10. The combined effect of chloride ion concentration and pH on the morphology of the pits was examined by scanning electron microscopy (SEM) following potentiodynamic cycling anodic polarization

  6. Real-time positioning in logging: Effects of forest stand characteristics, topography, and line-of-sight obstructions on GNSS-RF transponder accuracy and radio signal propagation.

    Directory of Open Access Journals (Sweden)

    Eloise G Zimbelman

    Full Text Available Real-time positioning on mobile devices using global navigation satellite system (GNSS technology paired with radio frequency (RF transmission (GNSS-RF may help to improve safety on logging operations by increasing situational awareness. However, GNSS positional accuracy for ground workers in motion may be reduced by multipath error, satellite signal obstruction, or other factors. Radio propagation of GNSS locations may also be impacted due to line-of-sight (LOS obstruction in remote, forested areas. The objective of this study was to characterize the effects of forest stand characteristics, topography, and other LOS obstructions on the GNSS accuracy and radio signal propagation quality of multiple Raveon Atlas PT GNSS-RF transponders functioning as a network in a range of forest conditions. Because most previous research with GNSS in forestry has focused on stationary units, we chose to analyze units in motion by evaluating the time-to-signal accuracy of geofence crossings in 21 randomly-selected stands on the University of Idaho Experimental Forest. Specifically, we studied the effects of forest stand characteristics, topography, and LOS obstructions on (1 the odds of missed GNSS-RF signals, (2 the root mean squared error (RMSE of Atlas PTs, and (3 the time-to-signal accuracy of safety geofence crossings in forested environments. Mixed-effects models used to analyze the data showed that stand characteristics, topography, and obstructions in the LOS affected the odds of missed radio signals while stand variables alone affected RMSE. Both stand characteristics and topography affected the accuracy of geofence alerts.

  7. Real-time positioning in logging: Effects of forest stand characteristics, topography, and line-of-sight obstructions on GNSS-RF transponder accuracy and radio signal propagation.

    Science.gov (United States)

    Zimbelman, Eloise G; Keefe, Robert F

    2018-01-01

    Real-time positioning on mobile devices using global navigation satellite system (GNSS) technology paired with radio frequency (RF) transmission (GNSS-RF) may help to improve safety on logging operations by increasing situational awareness. However, GNSS positional accuracy for ground workers in motion may be reduced by multipath error, satellite signal obstruction, or other factors. Radio propagation of GNSS locations may also be impacted due to line-of-sight (LOS) obstruction in remote, forested areas. The objective of this study was to characterize the effects of forest stand characteristics, topography, and other LOS obstructions on the GNSS accuracy and radio signal propagation quality of multiple Raveon Atlas PT GNSS-RF transponders functioning as a network in a range of forest conditions. Because most previous research with GNSS in forestry has focused on stationary units, we chose to analyze units in motion by evaluating the time-to-signal accuracy of geofence crossings in 21 randomly-selected stands on the University of Idaho Experimental Forest. Specifically, we studied the effects of forest stand characteristics, topography, and LOS obstructions on (1) the odds of missed GNSS-RF signals, (2) the root mean squared error (RMSE) of Atlas PTs, and (3) the time-to-signal accuracy of safety geofence crossings in forested environments. Mixed-effects models used to analyze the data showed that stand characteristics, topography, and obstructions in the LOS affected the odds of missed radio signals while stand variables alone affected RMSE. Both stand characteristics and topography affected the accuracy of geofence alerts.

  8. Heart rate and core temperature responses of elite pit crews during automobile races.

    Science.gov (United States)

    Ferguson, David P; Bowen, Robert S; Lightfoot, J Timothy

    2011-08-01

    There is limited information regarding the physiological and psychological demands of the racing environment, and the subsequent effect on the performance of pit crew athletes. The purpose of this study was to evaluate heart rates (HRs) and core body temperatures (CTs) of pit crew athletes in the race environment. The HR and CT of pit crew athletes (n = 7) and control subjects were measured during 6 National Association for Stock Car Automobile Racing Sprint Cup races using ingestible sensors (HQ Inc, Palmetto, FL, USA). The HR and CT were measured before each race, at 15-minute intervals during the race, and upon completion of each pit stop. Compared to the control subject at each race, the pit crew athletes had significantly (p = 0.014) lower core temperatures (CTs). The pit crew athletes displayed higher HRs on the asphalt tracks than on concrete tracks (p = 0.011), and HR responses of the crew members were significantly (p = 0.012) different between pit crew positions, with the tire changers and jackman exhibiting higher HRs than the tire carriers. Unexpectedly, the CTs of the pit crew athletes were not elevated in the race environment, despite high ambient temperatures and the extensive fire-protection equipment (e.g., helmet, suit, gloves) each pit crew athlete wore. The lack of CT change is possibly the result of the increased HR more efficiently shunting blood to the skin and dissipating heat as a consequence of the athletes' extensive training regimen and ensuing heat acclimation. Additionally, it is possible that psychological stress unique to several of the tracks provided an additive effect resulting in increased heart rates.

  9. Atypical pit craters on Mars: new insights from THEMIS, CTX and HiRISE observations

    Science.gov (United States)

    Cushing, Glen; Okubo, Chris H.; Titus, Timothy N.

    2015-01-01

    More than 100 pit craters in the Tharsis region of Mars exhibit morphologies, diameters and thermal behaviors that diverge from the much larger bowl-shaped pit craters that occur in most regions across Mars. These Atypical Pit Craters (APCs) generally have sharp and distinct rims, vertical or overhanging walls that extend down to their floors, surface diameters of ~50-350 m, and high depth-to-diameter (d/D) ratios that are usually greater than 0.3 (which is an upper-range value for impacts and bowl-shaped pit craters), and can exceed values of 1.8. Observations by the Mars Odyssey THermal Emission Imaging System (THEMIS) show that APC floor temperatures are warmer at night, and fluctuate with much lower diurnal amplitudes than nearby surfaces or adjacent bowl-shaped pit craters. Kīlauea volcano, Hawai'i, hosts pit craters that formed through subsurface collapse into active volcanic dikes, resulting in pits that can appear morphologically analogous to either APCs or bowl-shaped pit craters. Partially-drained dikes are sometimes exposed within the lower walls and floors of these terrestrial APC analogs and can form extensive cave systems with unique microclimates. Similar caves in martian pit craters are of great interest for astrobiology. This study uses new observations by the Mars Reconnaissance Orbiter (MRO) High Resolution Imaging Science Experiment (HiRISE) and Context Camera (CTX) to refine previous work where seven APCs were described from lower-resolution THEMIS visible-wavelength (VIS) observations. Here, we identify locations of 115 APCs, map their distribution across the Tharsis region, characterize their internal morphologies with high-resolution observations, and discuss possible formation mechanisms.

  10. In situ vitrification demonstration at Pit 1, Oak Ridge National Laboratory. Volume 2: Site characterization report of the Pit 1 area

    Energy Technology Data Exchange (ETDEWEB)

    Spalding, B.P.; Bogle, M.A.; Cline, S.R.; Naney, M.T.; Gu, B.

    1997-12-01

    A treatability study was initiated in October 1993, initially encompassing the application of in situ vitrification (ISV) to at least two segments of Oak Ridge National Laboratory (ORNL) seepage Pit 1 by the end of fiscal year (FY) 1995. This treatability study was to have supported a possible Interim Record of Decision (IROD) or removal action for closure of one or more of the seepage pits and trenches as early as FY 1997. The Remedial Investigation/Feasibility Study for Waste Area Grouping (WAG) 7, which contains these seven seepage pits and trenches, will probably not begin until after the year 2000. This treatability study will establish the field-scale technical performance of ISV for (1) attaining the required depth, nominally 15 ft, to incorporate source contamination within and beneath the pits; (2) demonstrating field capability to overlap melt settings that are necessary to achieve fused, melted segments of the source contamination; (3) demonstrating off-gas handling technology for accommodating and minimizing the volatilization of {sup 137}Cs; (4) demonstrating adequate site characterization techniques to predict ISV melting kinetics, processing temperatures, and product durability; and (5) promoting public acceptance of ISV technology by demonstrating its safety, implementability, site impacts, and air emissions and by coordinating the treatability study within the regulatory closure process. This report summarizes the site characterization information gathered through the end of September 1996 which supports the planning and assessment of ISV for Pit 1 (objective 4 above).

  11. In situ vitrification demonstration at Pit 1, Oak Ridge National Laboratory. Volume 2: Site characterization report of the Pit 1 area

    International Nuclear Information System (INIS)

    Spalding, B.P.; Bogle, M.A.; Cline, S.R.; Naney, M.T.; Gu, B.

    1997-12-01

    A treatability study was initiated in October 1993, initially encompassing the application of in situ vitrification (ISV) to at least two segments of Oak Ridge National Laboratory (ORNL) seepage Pit 1 by the end of fiscal year (FY) 1995. This treatability study was to have supported a possible Interim Record of Decision (IROD) or removal action for closure of one or more of the seepage pits and trenches as early as FY 1997. The Remedial Investigation/Feasibility Study for Waste Area Grouping (WAG) 7, which contains these seven seepage pits and trenches, will probably not begin until after the year 2000. This treatability study will establish the field-scale technical performance of ISV for (1) attaining the required depth, nominally 15 ft, to incorporate source contamination within and beneath the pits; (2) demonstrating field capability to overlap melt settings that are necessary to achieve fused, melted segments of the source contamination; (3) demonstrating off-gas handling technology for accommodating and minimizing the volatilization of 137 Cs; (4) demonstrating adequate site characterization techniques to predict ISV melting kinetics, processing temperatures, and product durability; and (5) promoting public acceptance of ISV technology by demonstrating its safety, implementability, site impacts, and air emissions and by coordinating the treatability study within the regulatory closure process. This report summarizes the site characterization information gathered through the end of September 1996 which supports the planning and assessment of ISV for Pit 1 (objective 4 above)

  12. New Generation Energy Efficient Refractory Application in Soaking Pits of Bhilai Steel Plant, Sail

    Science.gov (United States)

    Roy, Indranil; Chintaiah, Perumetla; Bhattacharya, Ajoy Kr.; Garai, Swapan Kr.; Ray Choudhury, Pankaj Kr.; Tiwari, Laksman

    In Bhilai Steel Plant (BSP), soaking pits are used for heating ingots for successive rolling into blooms. Pits are operated at a temperature of around 1350°C. Mixed gas (Mixture of Blast Furnace gas & Coke Oven gas) of calorific value around 2040 kcal/Nm3 is used as fuel. The walls of soaking pits were lined with traditional 38% Al2O3 firebricks and top 500mm was cast with 70% Al2O3 low cement castable (LCC). This type of lining results in frequent damages due to hitting by ingots while being lifted from pit by overhead cranes thus affecting the availability of pit. Life of pits was 2 to 2.5 years in BSP with 3-4 cold repairs and 3-4 hot repairs. Energy loss through the wall is also quite high in this type of lining. To triumph over the limitations of the conventional lining, a lining design was developed for the walls which consist of special 70% Al2O3 LCC having high hot strength (HMOR) in combination with specially design flexible SS-304 anchors. Ceramic fiber blanket and insulation bricks were provided between castable and the metallic shell of the pit to minimize the heat loss. A heating schedule was developed and introduced based on available infrastructure at BSP for proper curing of modified LCC based lining. After introduction of modified lining, pit no. 14/2 is running for more than 2.5 years without any repair. To capitalize the success, two more pits i.e. 12/1 and 9/2 were converted to modified lining. These pits are also running satisfactorily for more than 1.5 years. The modification has resulted in higher availability with substantial increase in production. Shell temperature of the modified pits reduced to 90° - 140°C from 120° - 200°C of conventional pits. This shows reduction in heat loss through walls, resulting less fuel consumption and energy saving of about 18%.

  13. Spatial statistics of pitting corrosion patterning: Quadrat counts and the non-homogeneous Poisson process

    International Nuclear Information System (INIS)

    Lopez de la Cruz, J.; Gutierrez, M.A.

    2008-01-01

    This paper presents a stochastic analysis of spatial point patterns as effect of localized pitting corrosion. The Quadrat Counts method is studied with two empirical pit patterns. The results are dependent on the quadrat size and bias is introduced when empty quadrats are accounted for the analysis. The spatially inhomogeneous Poisson process is used to improve the performance of the Quadrat Counts method. The latter combines Quadrat Counts with distance-based statistics in the analysis of pit patterns. The Inter-Event and the Nearest-Neighbour statistics are here implemented in order to compare their results. Further, the treatment of patterns in irregular domains is discussed

  14. Influence of the Haizhou Open Pit Coal Mine on the atmospheric flow over Fuxin, China.

    Science.gov (United States)

    Chen, He; Yang, Zhi-Feng; Wang, Xuan

    2004-01-01

    The influence of the Haizhou Open Pit Mine on the atmospheric flow in nearby Fuxin City in China was analyzed with the aid of the steady-state Navier-Stokes equations. The finite element method was used to obtain numerical solutions to these equations. The results showed that the Haizhou Open Pit Coal Mine contributes to the turbulent flow in the Fuxin City and its surroundings. However, when compared with the climatic effects, the open pit mine has a relatively small impact on the atmospheric flow over Fuxin.

  15. The pitting resistance of AISI 316 stainless steel passivated in diluted nitric acid

    International Nuclear Information System (INIS)

    Barbosa, M.A.

    1983-01-01

    The pitting resistance of AISI 316 stainless steel after passivation in diluted nitric acid was studied in comparison with that of non-passivated specimens. The passivation treatment increased the pitting potential but decreased the resistance to crevice corrosion under open circuit conditions in aerated sea water. Immersion in the nitric acid solution was found to remove the sulphide inclusions from the metal surface, thus eliminating the most susceptible sites for attack. In the absence of sulphide particles pitting nucleated at aluminium-rich oxides. (author)

  16. Numerical simulation of excavation and supporting of pit slope of the pump room in XNPC

    International Nuclear Information System (INIS)

    Hu Mengqian; Zhu Xiuyun; Ji Zhonghua; Lu Yu; Sun Feng

    2014-01-01

    The research simulates the excavation and supporting of pit slope of the pump room in XNPC. According to the designing of excavation and supporting plan of slope, the numerical simulation of excavation and supporting of pit slope is conducted using the ANSYS finite element numerical simulation software. The simulation results show that, the displacement and stress caused by the excavation of above stage slope and pit slope are both small after taking some measures, including deep mixing pile reinforcement, retaining piles and prestressed anchor cable. Thus the slope is steady. (authors)

  17. Effect of chloride concentration and pH on pitting corrosion of waste package container materials

    International Nuclear Information System (INIS)

    Roy, A.K.; Fleming, D.L.; Gordon, S.R.

    1996-12-01

    Electrochemical cyclic potentiodynamic polarization experiments were performed on several candidate waste package container materials to evaluate their susceptibility to pitting corrosion at 90 degrees C in aqueous environments relevant to the potential underground high-level nuclear waste repository. Results indicate that of all the materials tested, Alloy C-22 and Ti Grade-12 exhibited the maximum corrosion resistance, showing no pitting or observable corrosion in any environment tested. Efforts were also made to study the effect of chloride ion concentration and pH on the measured corrosion potential (Ecorr), critical pitting and protection potential values

  18. Inhibiting pitting corrosion in carbon steel exposed to dilute radioactive waste slurries

    International Nuclear Information System (INIS)

    Zapp, P.E.; Hobbs, D.T.

    1991-01-01

    Dilute caustic high-level radioactive waste slurries can induce pitting corrosion in carbon steel. Cyclic potentiodynamic polarization tests were conducted in simulated and actual waste solutions to determine minimum concentrations of sodium nitrate which inhibit pitting in ASTM A537 class 1 steel exposed to these solutions. Susceptibility to pitting was assessed through microscopic inspection of specimens and inspection of polarization scans. Long-term coupon immersion tests were conducted to verify the nitrite concentrations established by the cyclic potentiodynamic polarization tests. The minimum effective nitrite concentration is expressed as a function of the waste nitrate concentration and temperature

  19. Microstructure and pitting corrosion of 13CrNiMo weld metals

    International Nuclear Information System (INIS)

    Bilmes, P.D.; Llorente, C.L.; Saire Huaman, L.; Gassa, L.M.; Gervasi, C.A.

    2006-01-01

    Cyclic potentiodynamic measurements and scanning electron microscopy were used to analyze susceptibility to pitting corrosion of 13CrNiMo weld metals. In order to carry out a critical assessment of the influence of microstructural factors on localized corrosion, different heat treatments were applied to the alloys under investigation. Volume fractions of austenite in tempered conditions as well as the amount and size of precipitated carbides strongly affect pitting resistance. Characteristic potentials (pitting potential and repassivation potential) increase according to the retained austenite content. Results can be discussed in terms of a model that describes the structural refinement resulting from a double-tempering procedure

  20. A New Algorithm for Determining Ultimate Pit Limits Based on Network Optimization

    OpenAIRE

    Ali Asghar Khodayari

    2013-01-01

    One of the main concerns of the mining industry is to determine ultimate pit limits. Final pit is a collection of blocks, which can be removed with maximum profit while following restrictions on the slope of the mine’s walls. The size, location and final shape of an open-pit are very important in designing the location of waste dumps, stockpiles, processing plants, access roads and other surface facilities as well as in developing a production program. There are numerous methods for designing...

  1. Passive safe small reactor for distributed energy supply system sited in water filled pit at seaside

    International Nuclear Information System (INIS)

    Ishida, Toshihisa; Imayoshi, Shou

    2003-01-01

    Japan Atomic Energy Research Institute has developed a Passive Safe Small Reactor for Distributed Energy Supply System (PSRD) concept. The PSRD is an integrated-type PWR with reactor thermal power of 100 to 300 MW aimed at supplying electricity, district heating, etc. In design of the PSRD, high priority is laid on enhancement of safety as well as improvement of economy. Safety is enhanced by the following means: i) Extreme reduction of pipes penetrating the reactor vessel, by limiting to only those of the steam, the feed water and the safety valves, ii) Adoption of the water filled containment and the passive safety systems with fluid driven by natural circulation force, and iii) Adoption of the in-vessel type control rod drive mechanism, accompanying a passive reactor shut-down device. For improvement of economy, simplification of the reactor system and long operation of the core over five years without refueling with low enriched UO 2 fuel rods are achieved. To avoid releasing the radioactive materials to the circumstance even if a hypothetical accident, the containment is submerged in a pit filled with seawater at a seaside. Refueling or maintenance of the reactor can be conducted using an exclusive barge instead of the reactor building. (author)

  2. Abstraction of Models for Pitting and Crevice Corrosion of Drip Shield and Waste Package Outer Barrier

    International Nuclear Information System (INIS)

    Mon, K.

    2001-01-01

    This analyses and models report (AMR) was conducted in response to written work direction (CRWMS M and O 1999a). ICN 01 of this AMR was developed following guidelines provided in TWP-MGR-MD-000004 REV 01, ''Technical Work Plan for: Integrated Management of Technical Product Input Department'' (BSC 2001, Addendum B). The purpose and scope of this AMR is to review and analyze upstream process-level models (CRWMS M and O 2000a and CRWMS M and O 2000b) and information relevant to pitting and crevice corrosion degradation of waste package outer barrier (Alloy 22) and drip shield (Titanium Grade 7) materials, and to develop abstractions of the important processes in a form that is suitable for input to the WAPDEG analysis for long-term degradation of waste package outer barrier and drip shield in the repository. The abstraction is developed in a manner that ensures consistency with the process-level models and information and captures the essential behavior of the processes represented. Also considered in the model abstraction are the probably range of exposure conditions in emplacement drifts and local exposure conditions on drip shield and waste package surfaces. The approach, method, and assumptions that are employed in the model abstraction are documented and justified

  3. Abstraction of Models for Pitting and Crevice Corrosion of Drip Shield and Waste Package Outer Barrier

    Energy Technology Data Exchange (ETDEWEB)

    K. Mon

    2001-08-29

    This analyses and models report (AMR) was conducted in response to written work direction (CRWMS M and O 1999a). ICN 01 of this AMR was developed following guidelines provided in TWP-MGR-MD-000004 REV 01, ''Technical Work Plan for: Integrated Management of Technical Product Input Department'' (BSC 2001, Addendum B). The purpose and scope of this AMR is to review and analyze upstream process-level models (CRWMS M and O 2000a and CRWMS M and O 2000b) and information relevant to pitting and crevice corrosion degradation of waste package outer barrier (Alloy 22) and drip shield (Titanium Grade 7) materials, and to develop abstractions of the important processes in a form that is suitable for input to the WAPDEG analysis for long-term degradation of waste package outer barrier and drip shield in the repository. The abstraction is developed in a manner that ensures consistency with the process-level models and information and captures the essential behavior of the processes represented. Also considered in the model abstraction are the probably range of exposure conditions in emplacement drifts and local exposure conditions on drip shield and waste package surfaces. The approach, method, and assumptions that are employed in the model abstraction are documented and justified.

  4. Integrating Oil Debris and Vibration Gear Damage Detection Technologies Using Fuzzy Logic

    Science.gov (United States)

    Dempsey, Paula J.; Afjeh, Abdollah A.

    2002-01-01

    A diagnostic tool for detecting damage to spur gears was developed. Two different measurement technologies, wear debris analysis and vibration, were integrated into a health monitoring system for detecting surface fatigue pitting damage on gears. This integrated system showed improved detection and decision-making capabilities as compared to using individual measurement technologies. This diagnostic tool was developed and evaluated experimentally by collecting vibration and oil debris data from fatigue tests performed in the NASA Glenn Spur Gear Fatigue Test Rig. Experimental data were collected during experiments performed in this test rig with and without pitting. Results show combining the two measurement technologies improves the detection of pitting damage on spur gears.

  5. Analysis on the stress corrosion crack inception based on pit shape and size of the FV520B tensile specimen

    Science.gov (United States)

    Xiang, Longhao; Pan, Juyi; Chen, Songying

    2018-06-01

    The influence of pit shape and size on local stress concentration in the tensile specimen and the stress corrosion cracks inception was studied by employing the element remove technique. The maximum stress located in the bottom of pit on FV520B tensile specimen. The location of maximum strain was near the mouth of the pit or the shoulder and plastic strain existed in this region. Stress concentration factor and plastic deformation on four different geometrical shape pits of hemisphere, semi-ellipsoid, bullet and butterfly were numerically investigated, respectively. The simulation results showed that butterfly pit got the biggest stress concentration factor. The plastic strain rate during pit growth was in the sensitivity range of stress corrosion cracks inception, indicating that stress corrosion cracks were more likely to nucleate near the pit tip or the shoulder.

  6. A Statistical Study on the Effect of Hydrostatic Pressure on Metastable Pitting Corrosion of X70 Pipeline Steel.

    Science.gov (United States)

    Yang, Zixuan; Kan, Bo; Li, Jinxu; Qiao, Lijie; Volinsky, Alex A; Su, Yanjing

    2017-11-14

    Hydrostatic pressure effects on pitting initiation and propagation in X70 steel are investigated by evaluating metastable pitting probability using electrochemical methods and immersion corrosion tests in containing chlorine ion solution. Potentiodynamic tests indicated that hydrostatic pressure can decrease the breakdown potential and lead to a reduced transpassivity region. Metastable test results revealed that hydrostatic pressure can increase metastable pitting formation frequency and promote stabilization of metastable pitting growth. Electrochemical impedance spectroscopy (EIS) results indicate that Hydrostatic pressure decreases the charge transfer resistance and increases the dissolution rate within the cavities. Corrosion test results also indicated that pitting initiation and propagation are accelerated by hydrostatic pressure. Result validity was verified by evaluating metastable pitting to predict pitting corrosion resistance.

  7. Subsidence of the pit slab at SLC experimental hall

    International Nuclear Information System (INIS)

    Inaba, J.; Himeno, Yoichi; Katsura, Yutaka

    1992-01-01

    Detectors installed at particle accelerator facilities are quite heavy, weighing thousands of tons. On the other hand, ground subsidence caused by the installation of a detector adversely affects the beam line alignment of the collider. It becomes, therefore, very important to figure out the expected amount of ground settlement by means of adequate evaluation methods in advance. At Stanford Linear Accelerator Center (SLAC), a 1700 mT (metric tons) Mark II detector was replaced with a 4000 mT SLD detector in Stanford Linear Collider (SLC). The exchange started in December 1990 and lasted until March 1991, and the amount of ground settlement was measured by SLAC during that period. We performed simulation studies to evaluate the subsidence of the pit slab using several analysis methods. Parameters used for the analyses were decided based on the information of the SLC structure and the ground conditions at the SLAC area. The objective of this study is to verify the applicability of several simulation methods by comparing the analytical results with the actual subsidence data obtained by SLAC

  8. Use of a thermal imager for snow pit temperatures

    Directory of Open Access Journals (Sweden)

    C. Shea

    2012-03-01

    Full Text Available Weak snow of interest to avalanche forecasting often forms and changes as thin layers. Thermometers, the current field technology for measuring the temperature gradients across such layers – and for thus estimating the expected vapour flux and future type of crystal metamorphism – are difficult to use at distances shorter than 1 cm. In contrast, a thermal imager can provide thousands of simultaneous temperature measurements across small distances with better accuracy. However, a thermal imager only senses the exposed surface, complicating its methods for access and accuracy of buried temperatures. This paper presents methods for exposing buried layers on pit walls and using a thermal imager to measure temperatures on these walls, correct for lens effects with snow, adjust temperature gradients, adjust time exposed, and calculate temperature gradients over millimetre distances. We find lens error on temperature gradients to be on the order of 0.03 °C between image centre and corners. We find temperature gradient change over time to usually decrease – as expected with atmospheric equalization as a strong effect. Case studies including thermal images and visual macro photographs of crystals, collected during the 2010–2011 winter, demonstrate large temperature differences over millimetre-scale distances that are consistent with observed kinetic metamorphism. Further study is needed to use absolute temperatures independently of supporting gradient data.

  9. Herniation pits and their renaissance in association with femoroacetabular impingement

    International Nuclear Information System (INIS)

    Panzer, Stephonie; Augat, P.; Paracelsus Univ. Salzburg; Scheidler, J.

    2010-01-01

    Hernitation pits (HPs) of the femoral neck were first described in 1982. The purpose of this paper is to summarize the information concerning HPs published since then and to show their association with the diagnosis of femoroacetabular impingement (FAI) which has occurred within the last years. HPs are predominantly located at the anterior-superior femoral neck with a typical radiological appearance, which makes it possible to differentiate them from the numerous differential diagnoses mentioned. In the early publications HPs were described as a separate entity, while recent studies increasingly assign them to intra-osseous ganglia. In contrast to the early publications depicting HPs as an incidental finding, they are currently mainly mentioned in association with FAI and at the same time are partly considered to be a radiological indicator of FAI. In summary, HPs should always be recognized and documented because they may contribute to the diagnosis of FAI which is essential for preventing or delaying osteoarthritis of the hip joint in the early stage. (orig.)

  10. A mathematical model of crevice and pitting corrosion

    International Nuclear Information System (INIS)

    Sharland, S.M.; Tasker, P.W.

    1985-09-01

    A predictive and self-consistent mathematical model incorporating the electrochemical, chemical and ionic migration processes characterising crevice and pitting corrosion is described. The model predicts full details of the steady-state solution chemistry and electrode kinetics (and hence metal penetration rates) within the corrosion cavities as functions of the many parameters on which these depend such as external electrode potential and crevice dimensions. The crevice is modelled as a parallel-sided slot filled with a dilute sodium chloride solution. Corrosion in both one and two directions is considered. The model includes a solid hydroxide precipitation reaction and assesses the effect on the corrosion rates of consequent changes in the chemical and physical environment within the crevice. A time stepping method is developed for the study of the progression of the corrosion with a precipitation reaction included and is applied to a restricted range of parameters. The applicability of this method is justified in relation to the physical and mathematical approximations made during the construction of the model. (author)

  11. EARTHSAWtm IN-SITU CONTAINMENT OF PITS AND TRENCHES

    International Nuclear Information System (INIS)

    Ernest E. Carter, P.E.

    2002-01-01

    EarthSaw(trademark) is a proposed technology for construction of uniform high quality barriers under and around pits and trenches containing buried radioactive waste without excavating or disturbing the waste. The method works by digging a deep vertical trench around the perimeter of a site, filling that trench with high specific gravity grout sealant, and then cutting a horizontal bottom pathway at the base of the trench with a simple cable saw mechanism. The severed block of earth becomes buoyant in the grout and floats on a thick layer of grout, which then cures into an impermeable barrier. The ''Interim Report on task 1 and 2'' which is incorporated into this report as appendix A, provided theoretical derivations, field validation of formulas, a detailed quantitative engineering description of the technique, engineering drawings of the hardware, and a computer model of how the process would perform in a wide variety of soil conditions common to DOE waste burial sites. The accomplishments of task 1 and 2 are also summarized herein Task 3 work product provides a comprehensive field test plan in Appendix B and a health and safety plan in Appendix C and proposal for a field-scale demonstration of the EarthSaw barrier technology. The final report on the subcontracted stress analysis is provided in Appendix D. A copy of the unified computer model is provided as individual non-functional images of each sheet of the spreadsheet and separately as a Microsoft Excel 2000 file

  12. Flare pits wastes remediation by low temperature oxidation

    International Nuclear Information System (INIS)

    Catalan, L. J. L.; Jamaluddin, A. K. M.; Mehta, R.; Moore, R. G.; Okazawa, N.; Ursenbach, M.

    1997-01-01

    The remediation of contaminated soil in oilfield sites, flare pits in particular, is subject to strict environmental regulations. Most current remediation techniques such as biological or thermal treatment are not particularly effective in highly contaminated sites, or effective only at costs that are considered prohibitive. This contribution describes a cost-effective method for the treatment of contaminated soil in-situ. The proposed treatment involves low temperature oxidation which converts the hydrocarbons in the contaminated soil to inert coke. In laboratory studies contaminated soil was oxidized with air at temperatures between 150 degrees C and 170 degrees C for three weeks. After the three week treatment extractable hydrocarbon levels were reduced to less than 0.1 per cent. Bioassays also demonstrated that toxicity associated with hydrocarbons was eliminated. Salts and metals remaining in the soil after treatment were removed by leaching with water. Low temperature oxidation requires no special equipment; it can occur under conditions and with equipment that are readily available in an oilfield setting. 5 refs., 8 tabs., 7 figs

  13. EXCAVATION OF PITS (CHANNELS BY IMPACT OF PULSE POWER LOADING

    Directory of Open Access Journals (Sweden)

    Anakhaev Koshkinbai Nazirovich

    2017-08-01

    Full Text Available The paper provides an innovative hydromechanical solution of the problem of profiles development of pits and channels by impact of pulse (blasting power load on a surface of homogeneous soil mass, for example, when excavating solid rocks, frozen soil, etc. Thus, soil would be considered as an ideal heavy liquid (disregarding its mechanical strength and plastic properties. The solution of this problem is achieved by the method of consecutive conformal mappings of physical flow region (in the form of Kirchhoff complex on the region of complex potential (in the form of a rectangle. Thus, the new technique of geometrical image generation of the latter in the presence in the flow region of a fixed point with discontinuous variations of pressure head-flow function and the direction of speed of flow and representation of an elliptic sine of Jacobi by means of elementary functions are used. The received analytical functional dependencies allow to determine an outline of a funnel of the soil ejection and all the required hydromechanical characteristics of flow (head-flow function, function of flow, speed of flow, etc.. Thus, the soil ejection funnel outline (for a benchmark problem completely coincides with subproduct of the known rigorous solution of Lavrentyev-Kuznetsov.

  14. Modeling pitting growth data and predicting degradation trend

    International Nuclear Information System (INIS)

    Viglasky, T.; Awad, R.; Zeng, Z.; Riznic, J.

    2007-01-01

    A non-statistical modeling approach to predict material degradation is presented in this paper. In this approach, the original data series is processed using Accumulated Generating Operation (AGO). With the aid of the AGO which weakens the random fluctuation embedded in the data series, an approximately exponential curve is established. The generated data series described by the exponential curve is then modeled by a differential equation. The coefficients of the differential equation can be deduced by approximate difference formula based on least-squares algorithm. By solving the differential equation and processing an inverse AGO, a predictive model can be obtained. As this approach is not established on the basis of statistics, the prediction can be performed with a limited amount of data. Implementation of this approach is demonstrated by predicting the pitting growth rate in specimens and wear trend in steam generator tubes. The analysis results indicate that this approach provides a powerful tool with reasonable precision to predict material degradation. (author)

  15. EARTHSAWtm IN-SITU CONTAINMENT OF PITS AND TRENCHES

    Energy Technology Data Exchange (ETDEWEB)

    Ernest E. Carter, P.E.

    2002-09-20

    EarthSaw{trademark} is a proposed technology for construction of uniform high quality barriers under and around pits and trenches containing buried radioactive waste without excavating or disturbing the waste. The method works by digging a deep vertical trench around the perimeter of a site, filling that trench with high specific gravity grout sealant, and then cutting a horizontal bottom pathway at the base of the trench with a simple cable saw mechanism. The severed block of earth becomes buoyant in the grout and floats on a thick layer of grout, which then cures into an impermeable barrier. The ''Interim Report on task 1 and 2'' which is incorporated into this report as appendix A, provided theoretical derivations, field validation of formulas, a detailed quantitative engineering description of the technique, engineering drawings of the hardware, and a computer model of how the process would perform in a wide variety of soil conditions common to DOE waste burial sites. The accomplishments of task 1 and 2 are also summarized herein Task 3 work product provides a comprehensive field test plan in Appendix B and a health and safety plan in Appendix C and proposal for a field-scale demonstration of the EarthSaw barrier technology. The final report on the subcontracted stress analysis is provided in Appendix D. A copy of the unified computer model is provided as individual non-functional images of each sheet of the spreadsheet and separately as a Microsoft Excel 2000 file.

  16. Pitting growth modelling in buried oil and gas pipelines using statistical techniques

    International Nuclear Information System (INIS)

    Velazquez, J. C.; Caleyo, F.; Valorm, A.; Hallen, J. M.

    2011-01-01

    New deterministic and stochastic predictive models are proposed for external pitting corrosion in underground pipelines. The deterministic model takes into consideration the local chemical and physical properties of the soil as well as the pipeline coating to predict the time dependence of pitting depth and rate in a range of soils. This model, based on results from a field study, was used to conduct Monte Carlo simulations that established the probability distribution of pitting depth and growth rate in the studied soils and their evolution over the life of the pipeline. In the last stage of the study, an empirical Markov chain-based stochastic model was developed for predicting the evolution of pitting corrosion depth and rate distributions from the observed properties of the soil. (Author) 18 refs.

  17. Newall Glacier Snow Pit and Ice Core, 1987 to 1989, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — Snow pit and ice core data from the Newall Glacier (location - 162 30' East, 77 35' South) were collected during 1987 and 1988. These include information on...

  18. Mitigated Transfer Line Leaks that Result in Surface Pools and Spray Leaks into Pits

    Energy Technology Data Exchange (ETDEWEB)

    HEY, B.E.

    1999-12-07

    This analysis provides radiological and toxicological consequence calculations for postulated mitigated leaks during transfers of six waste compositions. Leaks in Cleanout Boxes equipped with supplemental covers and leaks in pits are analyzed.

  19. Analysis of reactivity worth for xenon poisoning during restart-up of reactor in iodine pit

    International Nuclear Information System (INIS)

    Li Xaofeng; Chen Wenzhen; Zhu Qian; Xu Guojun

    2009-01-01

    The reactivity worth of xenon poisoning and the densities of 135 I and 135 Xe were derived when the reactor was restarted up in iodine pit. Through the expressions obtained we can find the physics characteristics of reactor restarted up in iodine pit comprehensively and essentially. The results were analyzed and discussed. The reactor power before shutdown, the start-up power, the position where the reactor starts up in iodine pit, and so on, all have effect on the reactivity worth of xenon poisoning, and the different conditions can lead to totally different physics characteristics. In addition, the time when the reactor starts up in iodine pit is a very important factor for nuclear reactors safety. The conclusions are very important to the maneuverability and operation safety of ship nuclear reactors. (authors)

  20. Compromises in orchestra pit design: A ten-year trench war in The Royal Theatre, Copenhagen

    DEFF Research Database (Denmark)

    Gade, Anders Christian; Mortensen, Bo

    1998-01-01

    of opera finally opened the way for a new renovation of the pit, which solved most of the problems. The paper describes the many lessons learned during the ten-year period in which the authors were involved with the case as acoustic consultants. Questions of how pit configuration influences mutual hearing......The ``old stage'' of The Royal Theatre in Copenhagen-a classical horseshoe theatre with an almost flat audience floor and four balcony levels—is the primary opera and ballet theatre in Denmark. In the early 1980s the orchestra pit was enlarged and its size made flexible. However, in the following...... years this new flexibility caused a formal battle between the orchestra, the singers, and management, because each group had different interests as to how the pit should be configured for each new production. In the 1990s, increased concern about the musicians' hearing and the increase in the popularity...

  1. Laser surface melting of 304 stainless steel for pitting corrosion resistance improvement

    CSIR Research Space (South Africa)

    Seleka, TS

    2006-11-01

    Full Text Available optical emission spectroscopy (GDOES) was utilized for chemical analysis. Changes in hardness were observed by using a Vickers microhardness tester. Pitting corrosion tests on laser treated and untreated samples were conducted according to ASTM G48...

  2. A method for opening a mine field which is adjacent to a pit

    Energy Technology Data Exchange (ETDEWEB)

    Onishchenko, V.I.; Grebenyuk, V.K.; Kukharev, V.N.; Martynenko, V.P.; Omelnitskiy, A.G.; Sallin, V.I.; Sidorov, A.S.

    1982-01-01

    The method for opening a mine field adjacent to a pit includes the construction of the main and auxiliary opening drifts in the pit and the surface complex of the mine through assembling a support with subsequent filling of them by tailings of the covering rock. In order to increase the productive capacity of the mine, to reduce capital expenditures and to increase the safety of underground operations, a base is first formed from the tailing rock along the front of the open mining operations, from the bottom of the pit at the level of the stratum being opened to the surface with simultaneous layer by layer packing of the cited base, after which the opening drifts are built on this base. The mouth of the main opening drifts and the surface complex of the mine are positioned in the region of the pit.

  3. Description of work for 100-DR-2 Operable Unit Vadose Drilling/test pits

    International Nuclear Information System (INIS)

    Naiknimbalkar, N.

    1993-01-01

    This report describes the scope of work for the boreholes/test pits of the 100-DR-2 Operable Unit. Sampling and field activities include: Soil screening; geologic sampling; soil sampling (physical property); analytical sampling and depths; and geophysical logging

  4. PIT Tag data - Monitoring the migrations of wild Snake River spring/summer Chinook salmon juveniles

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This is an ongoing Bonneville Power Administration funded project to annually collect, PIT tag, and release wild Chinook salmon parr in up to 17 streams of the...

  5. Genetic variation of Pit-1 gene in Chinese indigenous and Western ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-07-20

    Jul 20, 2009 ... regulates pituitary development and expression of the growth hormone, prolactin and thyrotropin β- submit genes. Pit-1 ... mice (Camper et al., 1990), as well as including the .... logy Company, Shanghai, China). Statistical ...

  6. Correlation between evolution of inclusions and pitting corrosion in 304 stainless steel with yttrium addition.

    Science.gov (United States)

    Shi, Weining; Yang, Shufeng; Li, Jingshe

    2018-03-19

    Effects of the evolution of inclusions on the pitting corrosion resistance of 304 stainless steel with different contents of the rare-earth element yttrium (Y) were studied using thermodynamic calculations, accelerated immersion tests, and electrochemical measurements. The experimental results showed that regular Y 2 O 3 inclusions demonstrated the best pitting resistance, followed in sequence by (Al,Mn)O inclusions, the composite inclusions, and irregular Y 2 O 3 inclusions. The pitting resistance first decreased, then increased, and then decreased again with increasing Y content, because sulfide inclusions were easily generated when the Y content was low and YN inclusions were easily generated at higher Y contents. The best pitting corrosion resistance was obtained for 304 stainless steel with addition of 0.019% Y.

  7. The fabrication and application of patterned Si(001) substrates with ordered pits via nanosphere lithography

    International Nuclear Information System (INIS)

    Chen Peixuan; Fan Yongliang; Zhong Zhenyang

    2009-01-01

    A new scalable approach has been developed for fabricating large-scale pit patterns with controllable periodicity on Si(001) substrates. The fabrication processes start with self-assembling a monolayer of polystyrene (PS) spheres on hydrogenated Si(001) substrates. A novel net-like mask in combination of the Au pattern thermally evaporated in between the PS spheres and the Au-catalyzed SiO 2 around them is naturally formed. After selective etching of Si by KOH solution, two-dimensionally ordered pits with a periodicity equal to the diameter of the PS spheres in the range from micrometers to less than 100 nm can be obtained. The shape of the pits can be modulated by controlling the chemical etching time. Such pit-patterned Si substrates facilitate the formation of ordered Si-based nanostructures, such as ordered self-assembled GeSi quantum dots, by deposition of Ge using molecular beam epitaxy.

  8. Role of heat tint on pitting corrosion of 304 austenitic stainless steel in chloride environment

    Energy Technology Data Exchange (ETDEWEB)

    Elshawesh, F.; Elhoud, A. [Petroleum Research Center, P. O. Box 6431, Tripoli (Libyan Arab Jamahiriya)

    2004-07-01

    The effect of simulated heat tint produced by air oxidation at a wide range of temperatures 200, 400, 600, 800 and 1050 deg. C on pitting potential of 304 austenitic stainless steel was studied in environment of different chloride concentration. It was found that the heat tint effect depends on the heating temperature. The most effective heat tint was that produced at the high temperature up to 1050 deg. C and hence less pitting potential and low corrosion resistance. In order to improve the surface pitting corrosion resistance, acid pickling of hydrochloric acid was applied at different time and temperatures of 15 and 60 min, room temperature and 60 deg. C, respectively. Improvement in pitting potential was achieved as the pickling time and temperature increase. This is can be attributed to the removal of depleted chromium oxide film produced during the heat tint. (authors)

  9. Vestured pits: a diagnostic character in the secondary xylem of Myrtales

    NARCIS (Netherlands)

    Jansen, S.; Pletsers, A.; Rabaey, D.; Lens, F.

    2008-01-01

    Vestures are small projections from the secondary cell wall associated with tracheary elements of the secondary xylem. They are usually associated with bordered pits and characterize various angiosperm families, including important timber species such as Dipterocarpaceae and Eucalyptus trees. The

  10. Norm Levels in Mine Pit Lakes in South-Western Spain

    International Nuclear Information System (INIS)

    Manjón, G.; Galván, J.; Mantero, J.; Díaz, I.; García-Tenorio, R.

    2015-01-01

    Former mining activities in a pyritic area in south-western Spain have generated mine pits in which underground water and rainwater has accumulated. The accumulated waters have produced oxidation of the pyrite and, consequently, the pit water has become acidic, causing the dissolution of metals and radionuclides of natural origin. The paper discusses the activity concentration levels of uranium isotopes and other radionuclides in water samples and sediments collected from these mine pit lakes. Tributaries of the nearby Odiel River, when crossing the mining area, show low pH values and high concentrations of uranium isotopes due to acid mine drainage. Through the analysis of several isotope activity ratios, the presence of radionuclides in the pit lakes and the influence of these radionuclides on the surrounding area and the Odiel River are evaluated. (author)

  11. Mitigated Transfer Line Leaks that Result in Surface Pools and Spray Leaks into Pits

    International Nuclear Information System (INIS)

    HEY, B.E.

    1999-01-01

    This analysis provides radiological and toxicological consequence calculations for postulated mitigated leaks during transfers of six waste compositions. Leaks in Cleanout Boxes equipped with supplemental covers and leaks in pits are analyzed

  12. Influence of the filler material on the pitting corrosion in welded duplex stainless

    International Nuclear Information System (INIS)

    Munez, C. J.; Utrilla, M. V.; Urena, A.; Otero, E.

    2007-01-01

    In this work, it has been studied the pitting corrosion resistance of welding duplex stainless steel 2205. Unions were made by GMAW process with different fillers: duplex ER 2209 and two austenitic (ER 316LSi and ER 308LSi). the microstructure obtained with the duplex ER 2209 filler is similar to the duplex 2205 base material, but the unions produced with the austenitic fillers cause a decrease of the phases relationα/γ. To evaluate the influence of the filler on the weld, the pitting corrosion resistance was determined by electrochemical critical pitting temperature test (TCP) and the mechanical properties by the hardness. The phases imbalance produced for the dissimilar fillers bring out a variation of the pitting corrosion resistance and the mechanical properties. (Author)

  13. Pits, rifts and slumps: the summit structure of Piton de la Fournaise

    Science.gov (United States)

    Carter, Adam; van Wyk de Vries, Benjamin; Kelfoun, Karim; Bachèlery, Patrick; Briole, Pierre

    2007-06-01

    A clear model of structures and associated stress fields of a volcano can provide a framework in which to study and monitor activity. We propose a volcano-tectonic model for the dynamics of the summit of Piton de la Fournaise (La Reunion Island, Indian Ocean). The summit contains two main pit crater structures (Dolomieu and Bory), two active rift zones, and a slumping eastern sector, all of which contribute to the actual fracture system. Dolomieu has developed over 100 years by sudden large collapse events and subsequent smaller drops that include terrace formation. Small intra-pit collapse scars and eruptive fissures are located along the southern floor of Dolomieu. The western pit wall of Dolomieu has a superficial inward dipping normal fault boundary connected to a deeper ring fault system. Outside Dolomieu, an oval extension zone containing sub-parallel pit-related fractures extends to a maximum distance of 225 m from the pit. At the summit the main trend for eruptive fissures is N80°, normal to the north south rift zone. The terraced structure of Dolomieu has been reproduced by analogue models with a roof to width ratio of approximately 1, suggesting an original magma chamber depth of about 1 km. Such a chamber may continue to act as a storage location today. The east flank has a convex concave profile and is bounded by strike-slip fractures that define a gravity slump. This zone is bound to the north by strike-slip fractures that may delineate a shear zone. The southern reciprocal shear zone is probably marked by an alignment of large scoria cones and is hidden by recent aa lavas. The slump head intersects Dolomieu pit and may slide on a hydrothermally altered layer known to be located at a depth of around 300 m. Our model has the summit activity controlled by the pit crater collapse structure, not the rifts. The rifts become important on the mid-flanks of the cone, away from pit-related fractures. On the east flank the superficial structures are controlled

  14. Structure of energy consumption and improving open-pit dump truck efficiency

    Science.gov (United States)

    Koptev, V. Yu; Kopteva, A. V.

    2017-10-01

    This paper studies the dynamics of the improvement of wheel type transport vehicles environmental and energy performance in open-pit mines. The paper discloses characteristics of the gas turbine engine with capacity of 1250 hp, mounted on tanks, and technical-economic calculations, confirming reasonability of their use in open-pit dump trucks with the 120 …130-ton loading capacity. The general layout scheme of mechanical transmission with the gas turbine engine is shown.

  15. Enamel Pit Defects and Taurodontism in a Patient with Ring Chromosome 14 and 47,XXX.

    Science.gov (United States)

    Townsend, Janice A; Lacour, Letitia; Scheuerle, Angela E

    2017-01-15

    The purpose of this paper is to describe the clinical findings and management of a case involving a patient with co-occurring ring chromosome 14 syndrome and 47,XXX presenting with enamel pit defects and taurodontism. Ring chromosome 14 syndrome is an unusual condition with uncontrolled seizure disorder as its most significant finding; 47,XXX (trisomy X; triple X) is a more common condition and has characteristic physical and behavioral findings. Neither condition has been associated with enamel pit defects.

  16. Ground movement and deformation due to dewatering and open pit excavation

    International Nuclear Information System (INIS)

    Liu, B.; Yang, J.; Zhang, J.

    1996-01-01

    In the application of stochastic medium theory, it is assumed that ground movement process has the property of Markov Process. Based on superposition principle and rock consolidation principle, the ground movement and deformation due to dewatering and open pit excavation can be calculated. The comparison between the field measurements in Morwell Open Pit, Latrobe Valley (Victoria, Australia) and the calculated results shows the validity of the method in this paper. 5 refs

  17. Reconnection of SN-216 to U-D Valve Pit Design Review

    International Nuclear Information System (INIS)

    REED, R.W.

    1999-01-01

    The design for the reconnection of SN-216 to U-D valve pit was reviewed on May 24, 1999. All Review Comment Record comments were resolved and closed at this meeting. The review concluded that the reconnection of SN-216 to U-D valve pit was acceptable. The design was approved with the incorporated comments as recorded on the RCR's. No outstanding comments remain

  18. Ecological risk of reprocessing of uranium wastes of the Gafurov's tailing pit

    International Nuclear Information System (INIS)

    Khakimov, N.; Nazarov, Kh.M.; Kamalov, D.D.; Mirsaidov, U.M.

    2010-01-01

    Present article is devoted to assessment ecological risk of reprocessing of uranium wastes of the Gafurov's tailing pit. Authors set as their purpose the investigation of ecological risk of reprocessing of uranium wastes of the Gafurov-city's tailing pit. Having carried out their investigations, the authors came to the conclusion that the effect of radon gas during reprocessing to workers and specialists is minimal if they follow all the required safety rules.

  19. Designing local solutions for emptying pit latrines in low-income urban settlements (Malawi)

    Science.gov (United States)

    Chipeta, W. C.; Holm, R. H.; Kamanula, J. F.; Mtonga, W. E.; de los Reyes, F. L.

    2017-08-01

    A lack of effective options in local technology poses challenges when onsite household sanitation facilities are eventually filled to capacity in unplanned settlement areas within Mzuzu City, located in northern Malawi. Vacuum trucks currently dominate the market but focus on emptying septic tanks in the more easily accessible planned settlement areas, rather than servicing the pit latrines common in unplanned settlement areas. As a result, households in the unplanned settlement areas within Mzuzu rely primarily on manual pit emptying (i.e., shoveling by hand) or digging a new pit latrine. These practices have associated health risks and are limited by space constraints. This research focused on filling the technological gap through the design, development, and testing of a pedal powered modified Gulper pump using locally available materials and fabrication. A modified pedal powered Gulper technology was developed and demonstrated to be capable of lifting fecal sludge from a depth of 1.5 m with a mean flow rate of 0.00058 m3/s. If the trash content was low, a typical pit latrine with a volume of 1-4 m3 could be emptied within 1-2 h. Based on the findings in our research Phase IV, the pedal powered Gulper modification is promising as a potential emptying technology for lined pit latrines in unplanned settlement areas. The success rate of the technology is about 17% (5 out 30 sampled lined pit latrines were successful) and reflects the difficulty in finding a single technology that can work well in all types of pit latrines with varying contents. We note that cost should not be the only design criteria and acknowledge the challenge of handling trash in pit latrines.

  20. Software development for geologic information management system on open-pit production

    Energy Technology Data Exchange (ETDEWEB)

    Li, K.; Tian, A.; Ren, Z.; Pang, Y. [China University of Mining and Technomogy, Xuzhou (China). College of Mineral and Energy Resources

    2001-09-01

    A software, including geological data gathering and processing, deposit modelling, reserves calculating and mine map plotting, for geologic information management of open-pit production was developed. Based on the interactive technique, CAD, the object-oriented simulation, and the characteristics of geologic structures, all the geologic information databases and geologic mapping sub-systems have been established for open-pit production, planning and management. 6 refs., 1 fig.