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Sample records for american pit viper

  1. Structural and evolutionary insights into endogenous alpha-phospholipase A2 inhibitors of Latin American pit vipers.

    Science.gov (United States)

    Estevão-Costa, Maria Inácia; Fernandes, Carlos Alexandre H; Mudadu, Maurício de Alvarenga; Franco, Glória Regina; Fontes, Marcos Roberto M; Fortes-Dias, Consuelo Latorre

    2016-03-15

    Phospholipases A2 are major components of snake venoms (svPLA2s) and are able to induce multiple local and systemic deleterious effects upon envenomation. Several snake species are provided with svPLA2 inhibitors (sbPLIs) in their circulating blood, which confer a natural resistance against the toxic components of homologous and heterologous venoms. The sbPLIs belong to any of three structural classes named α, β and γ. In the present study, we identified, characterized and performed structural and evolutionary analyses of sbαPLIs transcripts and the encoded proteins, in the most common Latin American pit vipers belonging to Crotalus, Bothrops and Lachesis genera. Mutation data indicated that sbαPLIs from Latin American snakes might have evolved in an accelerated manner, similarly to that reported for sbαPLIs from Asian snakes, and possibly co-evoluted with svPLA2s in response to the diversity of target enzymes. The importance of sbαPLI trimerization for the effective binding and inhibition of acidic svPLA2s is discussed and conserved cationic residues located at the central pore of the inhibitor trimer are suggested to be a significant part of the binding site of sbαPLIs to acidic svPLA2s. Our data contribute to the current body of knowledge on the structural and evolutionary characteristics of sbPLIs, in general, and may assist in the future development of selective inhibitors for secretory PLA2 from several sources. PMID:26806211

  2. Distribution and abundance of pit vipers (Reptilia: Viperidae) along the Western Ghats of Goa, India

    OpenAIRE

    N.S. Sawant; T.D. Jadhav; S.K. Shyama

    2010-01-01

    The distribution and abundance of pit vipers in the Western Ghats namely Trimeresurus gramineus (Bamboo Pit Viper), T. malabaricus (Malabar Pit Viper) and Hypnale hypnale (Hump-nosed Pit Viper) was investigated in five wildlife sanctuaries of Goa from 2005 to 2009. Seasonal day-night data was collected based on band transect methods. All the pit viper species showed specific habitat preferences and their abundance changed with season. They were most abundant during monsoon. H. hypnale exte...

  3. Distribution and abundance of pit vipers (Reptilia: Viperidae along the Western Ghats of Goa, India

    Directory of Open Access Journals (Sweden)

    N.S. Sawant

    2010-09-01

    Full Text Available The distribution and abundance of pit vipers in the Western Ghats namely Trimeresurus gramineus (Bamboo Pit Viper, T. malabaricus (Malabar Pit Viper and Hypnale hypnale (Hump-nosed Pit Viper was investigated in five wildlife sanctuaries of Goa from 2005 to 2009. Seasonal day-night data was collected based on band transect methods. All the pit viper species showed specific habitat preferences and their abundance changed with season. They were most abundant during monsoon. H. hypnale extended its range to the adjoining cashew plantations during the post monsoon and winter.

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

  6. Venomics of New World pit vipers: Genus-wide comparisons of venom proteomes across Agkistrodon

    OpenAIRE

    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

    2013-01-01

    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 relativ...

  7. Identification and functional analysis of a novel bradykinin inhibitory peptide in the venoms of New World Crotalinae pit vipers

    International Nuclear Information System (INIS)

    A novel undecapeptide has been isolated and structurally characterized from the venoms of three species of New World pit vipers from the subfamily, Crotalinae. These include the Mexican moccasin (Agkistrodon bilineatus), the prairie rattlesnake (Crotalus viridis viridis), and the South American bushmaster (Lachesis muta). The peptide was purified from all three venoms using a combination of gel permeation chromatography and reverse-phase HPLC. Automated Edman degradation sequencing and MALDI-TOF mass spectrometry established its peptide primary structure as: Thr-Pro-Pro-Ala-Gly-Pro-Asp-Val-Gly-Pro-Arg-OH, with a non-protonated molecular mass of 1063.18 Da. A synthetic replicate of the peptide was found to be an antagonist of bradykinin action at the rat vascular B2 receptor. This is the first bradykinin inhibitory peptide isolated from snake venom. Database searching revealed the peptide to be highly structurally related (10/11 residues) with a domain residing between the bradykinin-potentiating peptide and C-type natriuretic peptide domains of a recently cloned precursor from tropical rattlesnake (Crotalus durissus terrificus) venom gland. BIP thus represents a novel biological entity from snake venom

  8. Identification and functional analysis of a novel bradykinin inhibitory peptide in the venoms of New World Crotalinae pit vipers.

    Science.gov (United States)

    Graham, Robert Leslie James; Graham, Ciaren; McClean, Stephen; Chen, Tianbao; O'Rourke, Martin; Hirst, David; Theakston, David; Shaw, Chris

    2005-12-23

    A novel undecapeptide has been isolated and structurally characterized from the venoms of three species of New World pit vipers from the subfamily, Crotalinae. These include the Mexican moccasin (Agkistrodon bilineatus), the prairie rattlesnake (Crotalus viridis viridis), and the South American bushmaster (Lachesis muta). The peptide was purified from all three venoms using a combination of gel permeation chromatography and reverse-phase HPLC. Automated Edman degradation sequencing and MALDI-TOF mass spectrometry established its peptide primary structure as: Thr-Pro-Pro-Ala-Gly-Pro-Asp-Val-Gly-Pro-Arg-OH, with a non-protonated molecular mass of 1063.18 Da. A synthetic replicate of the peptide was found to be an antagonist of bradykinin action at the rat vascular B2 receptor. This is the first bradykinin inhibitory peptide isolated from snake venom. Database searching revealed the peptide to be highly structurally related (10/11 residues) with a domain residing between the bradykinin-potentiating peptide and C-type natriuretic peptide domains of a recently cloned precursor from tropical rattlesnake (Crotalus durissus terrificus) venom gland. BIP thus represents a novel biological entity from snake venom. PMID:16277978

  9. Venoms of South Asian hump-nosed pit vipers (Genus: Hypnale cause muscarinic effects in BALB/c mice

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    A Silva

    2014-03-01

    Full Text Available Although clinical, in-vivo and in-vitro studies suggest the necrotic, haemorrhagic, pro-coagulant and nephrotoxic effects of South Asian Hump nosed pit vipers, reports on neurotoxic properties are limited to a single in-vitro study. Using BALB/c mice, for the first time, here we demonstrate the signs of envenoming suggestive of possible muscarinic effects of the venoms of all three Hypnale species. Further, we demonstrate that the muscarinic effects are occurred at lower venom doses by H. hypnale venom, compared to H. nepa and H. zara.

  10. First authenticated cases of life-threatening envenoming by the hump-nosed pit viper (Hypnale hypnale) in India.

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    Joseph, J K; Simpson, I D; Menon, N C S; Jose, M P; Kulkarni, K J; Raghavendra, G B; Warrell, D A

    2007-01-01

    In Kerala, south-western India, five patients developed systemic envenoming after bites by hump-nosed pit vipers (Hypnale hypnale), proved by identification of the snakes responsible. Two of the dead snakes had been misidentified as saw-scaled vipers (Echis carinatus), while three had remained unidentified. Symptoms of local envenoming were pain, swelling, haemorrhagic blistering, bruising and regional lymphadenopathy. Systemic symptoms included headache, nausea, vomiting and abdominal and chest pain. There was evidence of haemostatic dysfunction (coagulopathy, fibrinolysis, thrombocytopenia or spontaneous systemic haemorrhage) in all cases and of microangiopathic haemolysis in two. Two patients were haemodialysed for acute renal failure, one of whom developed pulmonary oedema requiring mechanical ventilation. In India, H. hypnale has not previously been regarded as a cause of frequent or potentially dangerous envenoming. Its medical importance has been overlooked throughout its geographical range, probably because of confusion with other small species. No specific antivenom exists, yet most patients are treated with non-specific antivenoms, risking reactions without hope of benefit. An effective antivenom is urgently needed in south India and in Sri Lanka, where this species is also a common cause of bites. PMID:16839578

  11. Frequent and potentially fatal envenoming by hump-nosed pit vipers (Hypnale hypnale and H. nepa) in Sri Lanka: lack of effective antivenom.

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    Ariaratnam, C A; Thuraisingam, V; Kularatne, S A M; Sheriff, M H R; Theakston, R D G; de Silva, A; Warrell, D A

    2008-11-01

    In a prospective study of snake bites involving 10 hospitals in Sri Lanka, 302 (35%) of 860 patients with bites by identified snakes proved to have been bitten by hump-nosed pit vipers (301 by Hypnale hypnale and 1 by H. nepa). Most victims were males aged between 11 years and 50 years who had been bitten on their feet or ankles while walking at night close to their homes. There was local swelling in 276 (91%) and local necrosis in 48 (16%). Eleven (4%) required amputation of fingers or toes and 12 (4%) received skin grafts. In 117 patients (39%) blood incoagulability was first detected between 15 min and 48 h after the bite, and in 116 of them this was present on admission to hospital. Spontaneous systemic bleeding was observed in 55 patients (18%). Acute renal failure developed in 10%, five of whom died to give an overall case fatality rate of 1.7%. Thus, bites by hump-nosed pit vipers can cause debilitating local and fatal systemic envenoming. In Sri Lanka and southwestern India where bites by these snakes are common, the only available antivenoms (raised against cobra, krait, Russell's viper and saw-scaled viper venoms) are ineffective and carry a high risk of reactions. PMID:18455743

  12. Habitat suitability, threats and conservation strategies of Hump-nosed Pit Viper Hypnale hymnal Merrem (Reptilia: Viperidae) found in Western Ghats, Goa, India

    OpenAIRE

    N.S. Sawant; T.D. Jadhav; S.K. Shyama

    2010-01-01

    Recent studies indicate that most species are best conserved in their natural community, which results in niche conservation. Depletion of any species is an irreversible change. In the present study the habitat ecology, threats and conservation strategies for the Hump-nosed Pit Viper Hypnale hypnale are suggested. The present study was undertaken in some protected areas (PAs) of Goa and the cashew plantations adjoining these PAs. H. hypnale prefers cool and moist places; most of the females o...

  13. Fatal diffuse thrombotic microangiopathy after a bite by the "Fer-de-Lance" pit viper (Bothrops lanceolatus) of Martinique.

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    Malbranque, Stéphane; Piercecchi-Marti, Marie Dominique; Thomas, Laurent; Barbey, Christophe; Courcier, Dominique; Bucher, Bernard; Ridarch, Alex; Smadja, Didier; Warrell, David A

    2008-06-01

    In Martinique, a man bitten two days earlier by a pit viper (Bothrops lanceolatus) was hospitalized with impaired consciousness and tetraplegia. Investigations confirmed cerebral and myocardial infarctions. Resolving thrombocytopenia was associated with virtually normal blood prothrombin time/activated partial thromboplastin time but increasing hyperfibrinogenemia. Despite specific antivenom treatment, he developed fatal left ventricular failure six days after the bite. At autopsy, multiple cerebral, myocardial and mesenteric infarctions were found. Rupture of mitral chordae tendinae was the likely cause of death. Histopathologic examination showed multi-focal thrombotic microangiopathy with intimal-medial dissection by thrombi extending from foci of endothelial damage in small cerebral, myocardial, pulmonary, mesenteric, and interlobular renal arteries and arterioles. These findings were the causes of infarctions. There was intense angiogenesis in organizing cerebral infarcts. Immunohistochemical analysis showed platelet aggregates and endothelial cells within microthrombi. Viperidae venoms contain vascular endothelial toxins, notably metalloproteinase hemorrhagins, but von Willebrand factor activators or vascular endothelial growth factor-type factors are more likely to have been implicated in this case. PMID:18541759

  14. Responses of infrared-sensitive tectal units of the pit viper Crotalus atrox to moving objects.

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    Kaldenbach, Felix; Bleckmann, Horst; Kohl, Tobias

    2016-06-01

    Rattlesnakes perceive IR radiation with their pit organs. This enables them to detect and strike towards warm-blooded prey even in the dark. In addition, the IR sense allows rattlesnakes to find places for thermoregulation. Animate objects (e.g., prey) tend to move and thus cause moving IR images across the pit membrane. Even when an object is stationary, scanning head movements of rattlesnakes will result in moving IR images across the pit membrane. We recorded the neuronal activity of IR-sensitive tectal neurons of the rattlesnake Crotalus atrox while stimulating the snakes with an IR source that moved horizontally at various velocities. As long as object velocity was low (angular velocity of ~5°/s) IR-sensitive tectal neurons hardly showed any responses. With increasing object velocity though, neuronal activity reached a maximum at ~50°/s. A further increase in object velocity up to ~120°/s resulted in a slight decrease of neuronal activity. Our results demonstrate the importance of moving stimuli for the snake's IR detection abilities: in contrast to fast moving objects, stationary or slowly moving objects will not be detected when the snake is motionless, but might be detected by scanning head movements. PMID:26906281

  15. Comparative in-vivo toxicity of venoms from South Asian hump-nosed pit vipers (Viperidae: Crotalinae: Hypnale

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    Silva Anjana

    2012-08-01

    Full Text Available Abstract Background Envenoming by south Asian hump-nosed pit vipers (Genus: Hypnale is a significant health issue in Sri Lanka and in peninsular India. Bites by these snakes frequently lead to local envenoming, coagulopathy and acute renal failure even resulting in death. Recently the genus was revised and the existence of three species viz H. hypnale, H. nepa and H. zara were recognized. There is, however, a paucity of information on the toxicity of the venoms of these species. Hence, we compared the toxic effects of the three Hypnale venoms using BALB/c mice. Findings Intraperitoneal median lethal doses (LD50 for H. hypnale, H. zara and H. nepa venoms were 1.6, 6.0 and 9.5 μg protein/g respectively. Minimum haemorrhagic doses for venoms of H. hypnale, H. zara and H. nepa were 3.4, 11.0 and 16.6 μg protein/mouse respectively. The minimum necrotic doses for the same venoms were 15.0, 55.1 and 68.2 μg protein/mouse respectively. Severe congestion and petecheal haemorrhages were observed in lungs, kidneys, liver and the alimentary tract. Histopathogical examination of kidneys revealed proximal tubular cell injury and acute tubular necrosis with intact basement membrane indicating possible direct nephrotoxicity. Hypnale venoms caused pulmonary oedema, hepatocellular degeneration and necrosis, focal neuronal degeneration in brain and extramedullary haemopoiesis in spleen. H. hypnale venom caused all above histopathological alterations at lower doses compared to the other two. Conclusion Hypnale venoms cause similar pathological changes with marked differences in the severity of the toxic effects in vivo. Therefore, differences in the severity of the clinical manifestations could possibly be seen among bite victims of the three Hypnale species.

  16. Enzymatic and toxinological activities of Hypnale hypnale (hump-nosed pit viper venom and its fractionation by ion exchange high performance liquid chromatography

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    CH Tan

    2011-01-01

    Full Text Available Hypnale hypnale (hump-nosed pit viper has been recently identified as one of the medically important venomous snakes in Sri Lanka and on the southwestern coast of India. The characterization of its venom is essential for understanding the pathophysiology of envenomation and for optimizing its management. In the present study, the biological properties of Hypnale hypnale venom and venom fractions obtained using Resource Q ion exchange chromatography were determined. The venom exhibited toxic activities typical of pit viper venom, comparable to that of its sister taxon, the Malayan pit viper (Calloselasma rhodostoma. Particularly noteworthy were its high activities of thrombin-like enzyme, proteases, phospholipase A2, L-amino acid oxidase and hyaluronidase. The thrombin-like enzyme was mainly acidic and distributed over several chromatography fractions, indicating its existence in multiple isoforms. The hemorrhagic and necrotic activities of the venom were likely associated with the proteolytic enzyme found mainly in the basic fraction. Phospholipase A2 and phosphomonoesterase exist in both acidic and basic isoforms, while L-amino acid oxidase and hyaluronidase are highly acidic. The venom clotting activity on fibrinogens showed distinct species specificity in the following increasing order for clotting time: bovine < rabbit < goat < human < horse < < dog, and was comparable to that of C. rhodostoma venom. Its clot formation on human fibrinogen is gradual and prolonged, a phenomenon suggestive of consumptive coagulopathy as a complication observed clinically. At an intramuscular sublethal dose, the venom did not cause acute kidney injury in a rodent model, contrary to the positive control group treated with Daboia russelii venom. Nephrotoxicity may result from higher venom doses in the context of coagulopathy, as a complication provoked by venom hematoxicity.

  17. Rare cardiac sequelae of a hump-nosed viper bite

    OpenAIRE

    Thillainathan, Sharmila; Priyangika, Dilani; Marasinghe, Indika; Kanapathippillai, Karunayokiny; Premawansa, Gayani

    2015-01-01

    Background The hump-nosed pit viper (Hypnale hypnale) is the commonest cause for venomous snakebites in Sri Lanka. Previously, it was thought to cause only local envenomation. However recently, several systemic effects and even mortality has been reported. Along with other snakes, such as the Indian cobra (Naja naja), the common krait (Bungarus caeruleus), the Russell’s viper (Daboia russelii) and the saw-scaled viper (Echis carinatus), the hump-nosed viper is now also considered capable of c...

  18. Habitat suitability, threats and conservation strategies of Hump-nosed Pit Viper Hypnale hymnal Merrem (Reptilia: Viperidae found in Western Ghats, Goa, India

    Directory of Open Access Journals (Sweden)

    N.S. Sawant

    2010-10-01

    Full Text Available Recent studies indicate that most species are best conserved in their natural community, which results in niche conservation. Depletion of any species is an irreversible change. In the present study the habitat ecology, threats and conservation strategies for the Hump-nosed Pit Viper Hypnale hypnale are suggested. The present study was undertaken in some protected areas (PAs of Goa and the cashew plantations adjoining these PAs. H. hypnale prefers cool and moist places; most of the females of this species are found to spend the period from post monsoon to late summer in the cashew plantations adjoining and within the PAs, making them more susceptible to anthropogenic threats. We conclude that this pattern of seasonal changes in habitat use is mostly a consequence of niche conservation. However, this preference for a particular micro-habitat emphasizes the importance for the conservation of this snake population and although the most suitable habitat in the Western Ghats, for this species is included in the protected areas, specific guidelines are needed to assess conservation needs.

  19. Inhibition of the hemorrhagic and proteolytic activities of Lansberg's hognose pit viper (Porthidium lansbergii hutmanni) venom by opossum (Didelphis marsupialis) serum: isolation of Didelphis marsupialis 0.15Dm fraction on DEAE-cellulose chromatography.

    Science.gov (United States)

    Pineda, María E; Girón, María E; Estrella, Amalid; Sánchez, Elda E; Aguilar, Irma; Fernandez, Irma; Vargas, Alba M; Scannone, Héctor; Rodríguez-Acosta, Alexis

    2008-01-01

    Earlier studies have revealed the ability of sera from several mammals to neutralize the toxic effects of snake venom. The Venezuelan opossum (Didelphis marsupialis) is one that has been found to inhibit hemorrhagic and proteolytic activities of venoms from many species of snakes. In this article it is shown that the opossum sera and its 0.15DM fraction were able to completely neutralize both hemorrhagic and hydrolysis (proteolysis) of casein effects induced by venom of the Lansberg's hognose pit viper (Porthidium lansbergii hutmanni). We have used DEAE-cellulose ion exchange chromatography to collect protein fractions from D. marsupialis sera which were able to defend mice from the lethal effects of P.l. hutmanni venom. The fractions separated were homogeneous by conventional electrophoresis using SDS-PAGE. The protein bands obtained contained molecular weights of approximately 6 to 220 kDa. These results revealed the presence of proteases inhibitors in the opossum sera fractions and the inhibition of venom activity by opossum sera suggesting a reciprocal adaptation at the molecular level. PMID:18800269

  20. Viper. [Design modification

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    Gilbert, L. E. Paul; Berry, Cassie; Lamborn, Dana; Murphy, Jack; Okelly, Chris

    1993-01-01

    A Viper aircraft was redesigned with a new airfoil and engine to verify if improvements can be made to the baseline configuration. The two major redesigning processes were: replacing the baseline aircraft's NACA 652-415 airfoil with an NLF 0414 Natural Laminar Flow airfoil, and the baseline aircraft's Lycoming 0-235 engine with a Teledyne Continental GR-36 rotary combustion engine. As a result of these changes: (1) the Viper aircraft becomes smaller in most respects (gross weight, wing platform area, and horizontal tail area); (2) overall drag of the aircraft decreased (due to reduction in area and the reduced drug of the new airfoil); (3) cruise velocity, the maximum rate of climb at sea level, and takeoff distance (but not landing distance) decreased; and (4) cost increased. Although the overall drag decreased, the performance remained about the same due to the reduced horsepower available from the Teledyne Continental engine.

  1. [Viper envenomation by Echis coloratus].

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    Gilon, D; Mann, G; Shalev, O

    1991-06-01

    Clinical and therapeutic experience with 24 cases of envenomation by Echis coloratus, the Mideast saw-scaled viper, is reported. These cases were seen between 1979-1989 at this hospital (Mt. Scopus). A clinical classification is proposed, based on severity of the bleeding diathesis and platelet count at presentation. It is suggested as a predictor of clinical outcome and as a guide to whether antiserum should be administered. PMID:1937209

  2. Predator facilitation or interference: a game of vipers and owls.

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    Embar, Keren; Raveh, Ashael; Hoffmann, Ishai; Kotler, Burt P

    2014-04-01

    In predator-prey foraging games, the prey's reaction to one type of predator may either facilitate or hinder the success of another predator. We ask, do different predator species affect each other's patch selection? If the predators facilitate each other, they should prefer to hunt in the same patch; if they interfere, they should prefer to hunt alone. We performed an experiment in a large outdoor vivarium where we presented barn owls (Tyto alba) with a choice of hunting greater Egyptian gerbils (Gerbillus pyramidum) in patches with or without Saharan horned vipers (Cerastes cerastes). Gerbils foraged on feeding trays set under bushes or in the open. We monitored owl location, activity, and hunting attempts, viper activity and ambush site location, and the foraging behavior of the gerbils in bush and open microhabitats. Owls directed more attacks towards patches with vipers, and vipers were more active in the presence of owls. Owls and vipers facilitated each other's hunting through their combined effect on gerbil behavior, especially on full moon nights when vipers are more active. Owls forced gerbils into the bushes where vipers preferred to ambush, while viper presence chased gerbils into the open where they were exposed to owls. Owls and vipers took advantage of their indirect positive effect on each other. In the foraging game context, they improve each other's patch quality and hunting success. PMID:24481981

  3. Use of gamma irradiated viper venom as the toxoid against viper venom poisoning in mice and rabbits

    International Nuclear Information System (INIS)

    The present paper deals with detoxification of the crude viper (Vipera russelli) venom by gamma irradiation and its effective immunogenic role in Balb/C mice, used as a toxoid. The successful immunization of rabbits with irradiated viper venom toxoid is also reported. Certain biochemical changes of the venom due to radiation exposure and neutralization capacity of the immune sera against phosphodiesterase and protease activity of the crude viper venom have also been studied. The neutralizing potency of Russell's viper venom (RVV) toxoid anti venom (anti venom raised in rabbits against γ-irradiated RVV toxoid adsorbed on aluminium phosphate), in comparison with a commercial bivalent anti venom (as a standard reference) with reference to haemorrhagic, necrotic and lethal effects of Russell's viper envenomation are reported. 25 refs

  4. Pitted keratolysis*

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    de Almeida Jr, Hiram Larangeira; Siqueira, Rodrigo Nunes; Meireles, Renan da Silva; Rampon, Greice; de Castro, Luis Antonio Suita; Silva, Ricardo Marques e

    2016-01-01

    Pitted keratolysis is a skin disorder that affects the stratum corneum of the plantar surface and is caused by Gram-positive bacteria. A 30-year-old male presented with small punched-out lesions on the plantar surface. A superficial shaving was carried out for scanning electron microscopy. Hypokeratosis was noted on the plantar skin and in the acrosyringium, where the normal elimination of corneocytes was not seen. At higher magnification (x 3,500) bacteria were easily found on the surface and the described transversal bacterial septation was observed. PMID:26982791

  5. Optic Nerve Pit

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    ... 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 ...

  6. Eye and pit size are inversely correlated in crotalinae: Implications for selection pressure relaxation.

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    Liu, Yang; Chen, Qin; Papenfuss, Theodore J; Lu, Fang; Tang, Yezhong

    2016-01-01

    Mate, prey, and predator recognition often depend on the integration of information from multiple sensory modalities including visual, auditory, and/or olfactory inputs. In Crotalinae, the eyes sense visible light while the pit organs detect infrared (IR) radiation. Previous studies indicate that there is significant overlap between the eye and pit sensory fields and that both senses are involved in recognition processes. This study investigated the relationships between eye and pit sizes in this taxonomic group as a function of phylogeny and habitat. In view of the fact that pit orientation depends largely on snout shape, pit vipers were grouped as follows: 1) arboreal, 2) terrestrial with rounded snout, and 3) terrestrial with pointed snout. The pit orientations and habitant patterns were fully independent of the Crotalinae phylogenetic tree. The phylogenetic generalized least squares model showed that both eye and pit areas were not of significantly phylogenetic relatedness, implying alternatively a strong effect of adaptation on eye and pit sizes. Negative correlations between relative eye and pit areas in terrestrial (both pointed and rounded snouts) and arboreal species were statistically significant. Our results suggest that the eyes and pits function in a complementary fashion such that selection for IR-perception relaxes selection pressures on the visual system and selection for visual discrimination relaxes selection pressures acting on the IR-system. PMID:26442780

  7. Debunking the viper's strike: harmless snakes kill a common assumption.

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    Penning, David A; Sawvel, Baxter; Moon, Brad R

    2016-03-01

    To survive, organisms must avoid predation and acquire nutrients and energy. Sensory systems must correctly differentiate between potential predators and prey, and elicit behaviours that adjust distances accordingly. For snakes, strikes can serve both purposes. Vipers are thought to have the fastest strikes among snakes. However, strike performance has been measured in very few species, especially non-vipers. We measured defensive strike performance in harmless Texas ratsnakes and two species of vipers, western cottonmouths and western diamond-backed rattlesnakes, using high-speed video recordings. We show that ratsnake strike performance matches or exceeds that of vipers. In contrast with the literature over the past century, vipers do not represent the pinnacle of strike performance in snakes. Both harmless and venomous snakes can strike with very high accelerations that have two key consequences: the accelerations exceed values that can cause loss of consciousness in other animals, such as the accelerations experienced by jet pilots during extreme manoeuvres, and they make the strikes faster than the sensory and motor responses of mammalian prey and predators. Both harmless and venomous snakes can strike faster than the blink of an eye and often reach a target before it can move. PMID:26979562

  8. Palestine Saw-scaled Vipers hunt disadvantaged avian migrants.

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    Yosef, Reuven; Zduniak, Piotr

    2015-11-01

    The selection of an ambush-cum-foraging site and proper prey are indispensable for maintaining an adequate energy intake by sit-and-wait predators to optimize survival and future fitness. This is important for snakes, where an ambush site has suitable ambience. We studied the foraging strategy of the Palestine Saw-scaled Viper (Echis coloratus) at an avian migratory stopover site. Following initial observations, we hypothesized that vipers are able to discern the body mass of a perched bird and hunt accordingly. We implemented an experiment where vipers chose between four groups of migratory Blackcaps with different body mass. Prey choice by vipers of both age classes was not random and adults focused on Blackcaps with the lightest body mass. Juveniles displayed a variability of prey choice but selected mainly birds from the lightest categories. We concluded that Saw-scaled Vipers hunt prey based on thermal cues; juveniles practice on different prey groups prior to perfecting their foraging techniques i.e., hunting is a learned process; and that they prefer birds with the lowest body mass. The last because Blackcaps, when on migration, save energy by entering a state of deep torpor in which they sacrifice their vigilance capabilities. PMID:26319368

  9. Cerebral infarction: an unusual manifestation of viper snake bite

    Directory of Open Access Journals (Sweden)

    Jyotirmoy Pal

    2014-06-01

    Full Text Available Snake envenomation causes significant mortality and morbidity. Viper bite usually present with local cellulites, renal failure and bleeding disorders. Thrombotic manifestation of snake bite is rarely reported and early administration of Anti-Snake Venom Serum (ASV also reduces the risk of thrombotic complications. Cerebral infarction in case of viper bite may be due to hypotension, hypercoagulability or direct action of venom on vessel wall. We report a rare case of viper bite, presented with renal failure and cerebral infarction in spite of early ASV institution. The thrombotic manifestation in this case was possibly due to disseminated intravascular coagulation. [Int J Res Med Sci 2014; 2(3.000: 1180-1183

  10. 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...

  11. Two cases of viper bite: still an important health problem

    Directory of Open Access Journals (Sweden)

    Adrija Hajra

    2016-04-01

    Full Text Available Viper venoms act mainly as hemotoxic. Manifestations of snakebites depend on specific toxins that constitute the venom. The local and systemic snake bite related symptoms are directly linked to the toxicity of the venom. Edema, ecchymoses, hematoma, and gangrenous lesions are reported to occur as local symptoms. Systemic symptoms may include fever, nausea, vomiting, delirium, jaundice, circulatory collapse, convulsions, and coma. Death from secondary infections, neurotoxicity, disseminated intravascular coagulation (DIC, intracranial hemorrhage, and acute renal failure are the well-known facts. For reduction of morbidity and mortality, it is important that antiserum is administered at the appropriate dose as early as possible after snake bite. There are several case reports about various complications of viperid bite. Here we are discussing two cases of viper bite. These cases are unique because of the extensive tissue necrosis. One of them succumbed to septicemia after acute pancreatitis. [Int J Res Med Sci 2016; 4(4.000: 1274-1277

  12. Ecotoxicological effects of Mikado and Viper on algae and daphnids.

    Science.gov (United States)

    Marques, C R; Gonçalves, A M M; Pereira, R; Gonçalves, F

    2012-12-01

    The toxicity of single and combined formulated herbicides (Mikado and Viper) was assessed on several endpoints in species from two trophic levels: algae growth-Pseudokirchneriella subcapitata and Chlorella vulgaris-immobilization and life-history traits (only for single compound toxicity) of daphnids-Daphnia longispina and Daphnia magna. Viper was the most toxic formulated herbicide. It was hypothesized that the toxicity of both formulated herbicides could have been enhanced by adjuvants, especially for Viper. In most cases, the sublethal endpoints were the most sensitive and affected by both formulations, comparatively to their acute effects. Concentration addition (CA) and independent action (IA) models provided an accurate description of Mikado and Viper joint action on algae growth and immobilization of daphnids, although significant deviations were always detected. A low-dose antagonism and high-dose synergism were identified for P. subcapitata, whereas C. vulgaris response deviated antagonistically from CA and synergistically from IA. For both daphnids, however, synergistic effects were observed for higher mixture concentrations. Under a regulatory standpoint, CA provided the most conservative estimation either because the mixture effects were overestimated or less subestimated than IA. Overall, the great sensitivity differences observed within species did not allow the conclusion that one trophic level was more tolerant than the other. Instead, P. subcapitata was always the most sensitive species to both herbicide formulations, followed by D. longispina, while D. magna and C. vulgaris were the most tolerant species. On a whole, further studies are needed toward a comprehensive understanding of herbicides mode of action, their effects at lower biological-level endpoints, and under different mixture designs. PMID:21374788

  13. Two cases of viper bite: still an important health problem

    OpenAIRE

    Adrija Hajra; Dhrubajyoti Bandyopadhyay

    2016-01-01

    Viper venoms act mainly as hemotoxic. Manifestations of snakebites depend on specific toxins that constitute the venom. The local and systemic snake bite related symptoms are directly linked to the toxicity of the venom. Edema, ecchymoses, hematoma, and gangrenous lesions are reported to occur as local symptoms. Systemic symptoms may include fever, nausea, vomiting, delirium, jaundice, circulatory collapse, convulsions, and coma. Death from secondary infections, neurotoxicity, disseminated in...

  14. Antipredatory Function of Head Shape for Vipers and Their Mimics

    OpenAIRE

    Valkonen, Janne; Nokelainen, Ossi; Mappes, Johanna

    2011-01-01

    Most research into the adaptive significance of warning signals has focused on the colouration and patterns of prey animals. However, behaviour, odour and body shape can also have signal functions and thereby reduce predators' willingness to attack defended prey. European vipers all have a distinctive triangular head shape; and they are all venomous. Several non-venomous snakes, including the subfamily Natricinae, commonly flatten their heads (also known as head triangulation) when disturbed....

  15. Dermoscopy of pitted keratolysis

    OpenAIRE

    Lockwood, L L; Gehrke, S. (Susanne); Navarini, A A

    2010-01-01

    Irritated hyperhidrotic soles with multiple small pits are pathognomonic for pitted keratolysis (PK). Here we show the dermatoscopic view of typical pits that can ensure the diagnosis. PK is a plantar infection caused by Gram-positive bacteria, particularly Corynebacterium. Increases in skin surface pH, hyperhidrosis, and prolonged occlusion allow these bacteria to proliferate. The diagnosis is fundamentally clinical and treatment generally consists of a combination of hygienic measures, corr...

  16. Dermoscopy of Pitted Keratolysis

    Directory of Open Access Journals (Sweden)

    Lauren L. Lockwood

    2010-08-01

    Full Text Available Irritated hyperhidrotic soles with multiple small pits are pathognomonic for pitted keratolysis (PK. Here we show the dermatoscopic view of typical pits that can ensure the diagnosis. PK is a plantar infection caused by Gram-positive bacteria, particularly Corynebacterium. Increases in skin surface pH, hyperhidrosis, and prolonged occlusion allow these bacteria to proliferate. The diagnosis is fundamentally clinical and treatment generally consists of a combination of hygienic measures, correcting plantar hyperhidrosis and topical antimicrobials.

  17. Phylogenetic relationship among vipers of the Vipera ursinii – renardi complex

    Czech Academy of Sciences Publication Activity Database

    Gvoždík, Václav; Kotlík, Petr; Jandzik, D.; Cordos, B.; Řehák, I.

    Porto : Cibio, 2007, s. 50-50. [Biology of the Vipers Conference /2./. Porto (PT), 24.09.2007-27.09.2008] R&D Projects: GA MŠk LC06073 Grant ostatní: GA ČR(CZ) GA206/05/2334 Institutional research plan: CEZ:AV0Z50450515 Keywords : viper Subject RIV: EG - Zoology

  18. Graphite waste pit cleanup

    International Nuclear Information System (INIS)

    The UP1 plant in Marcoule reprocessed nearly 20,000 tons of used natural uranium gas cooled reactor fuel coming from the first generation of civil nuclear reactors in France. During more than 40 years, the decladding operations produced thousands of tons of processed waste, mainly magnesium and graphite fragments. In the absence of a French repository for the graphite waste, the graphite sludge content of the storage pit had to be retrieved and transferred into a newer and safer pit. So, this project consists in the full retrieval and transfer of 15 m3 of water mixed with graphite dust located in the decladding facility, as well as the complete cleanup and decontamination of the pit. The equipment and process necessary for retrieval operations were designed, built and tested. The process is mainly based on the use of two pumps (one to capture and the other one to transfer the sludge) working one after the other and a robotic arm mounted on a telescopic mast. A dedicated process was also set up for the removal of the biggest fragments. In the pit, the sludge retrieval and transfer operations have been almost completed. Most of the non-pumpable graphite fragments has been removed and transferred to a new storage pit. As irradiant fragments have been discovered in the pit, specific studies are in progress in order to remove them to the laboratory for dissolution. This work is expected to 2014. (authors)

  19. Sand pits and gravel-sand pits

    Czech Academy of Sciences Publication Activity Database

    Řehounková, Klára; Řehounek, J.; Beran, L.; Bogusch, P.; Blízek, J.; Boukal, M.; Grycz, F.; Hátle, M.; Hlásek, J.; Heneberg, P.; Hesoun, P.; Konvička, Martin; Lepšová, A.; Matějček, T.; Rektoris, L.; Stárka, L.; Zavadil, V.

    České Budějovice : Faculty of Science, University of South Bohemia in České Budějovice, 2011 - (Řehounková, K.; Řehounek, J.; Prach, K.), s. 51-67 ISBN 978-80-7394-322-6 R&D Projects: GA ČR(CZ) GAP505/11/0256 Institutional research plan: CEZ:AV0Z60050516; CEZ:AV0Z50070508 Institutional support: RVO:67985939 ; RVO:60077344 Keywords : sand pits Subject RIV: EH - Ecology, Behaviour

  20. Studies on pharmacological effects of Russell's viper and Saw-scaled viper venom and its neutralization by chicken egg yolk antibodies.

    Science.gov (United States)

    Meenatchisundaram, S; Parameswari, G; Michael, A; Ramalingam, S

    2008-08-01

    Antivenom antibodies were raised in 24-week-old white leghorn chickens against hemotoxic venoms of Russell's viper and Saw-scaled viper snakes. Booster injections of increasing concentrations of venom were given at 14days of time interval to raise the antivenom level in egg yolk. Antibodies were extracted from immunized chicken egg yolk by Polson et al. (Polson A., Von Wechmar M.B., Van Regenmortel M.H.V. Isolation of viral IgY antibodies from yolks of immunized hens. Immunological Communications 1980; 9:475-493.) and further purified by DEAE cellulose ion exchange column chromatography, which gave pure (180-200kDa) specific antibodies against venom. High titre of more than 1:10,000 antibodies were detected by ELISA at the 135th day of observation. The lethal toxicity and various pharmacological activities like hemorrhagic activity, phospholipase activity, edema and procoagulant activities of venom were carried out by both in vivo and in vitro methods. The effectiveness of antivenom in neutralizing these effects was carried out involving pre-incubation type experiments. The median effective dose (ED50) for Russell's viper venom was 0.96mg/2LD50/18g mice and for Saw-scaled viper venom it was 1.28mg/2LD50/18g mice. One millilitre of specific antivenom was effective in neutralizing 0.110mg of Russell's viper and 0.137mg of Saw-scaled viper venoms respectively (PD50). Antivenom was effective in neutralization assays in a dose dependent manner. The results indicate that antibodies raised in chicken could effectively neutralize the pharmacological effects induced by venoms and chickens therefore present an alternative and cheaper source of specific antibody generation. PMID:18550009

  1. Clustering-based redshift estimation: application to VIPERS/CFHTLS

    CERN Document Server

    Scottez, V; Granett, B R; Moutard, T; Kilbinger, M; Scodeggio, M; Garilli, B; Bolzonella, M; de la Torre, S; Guzzo, L; Abbas, U; Adami, C; Arnouts, S; Bottini, D; Branchini, E; Cappi, A; Cucciati, O; Davidzon, I; Fritz, A; Franzetti, P; Iovino, A; Krywult, J; Brun, V Le; Fèvre, O Le; Maccagni, D; Małek, K; Marulli, F; Polletta, M; Pollo, A; Tasca, L A M; Tojeiro, R; Vergani, D; Zanichelli, A; Bel, J; Coupon, J; De Lucia, G; Ilbert, O; McCracken, H J; Moscardini, L

    2016-01-01

    We explore the accuracy of the clustering-based redshift estimation proposed by M\\'enard et al. (2013) when applied to VIPERS and CFHTLS real data. This method enables us to reconstruct redshift distributions from measurement of the angular clus- tering of objects using a set of secure spectroscopic redshifts. We use state of the art spectroscopic measurements with iAB 0.5 which allows us to test the accuracy of the clustering-based red- shift distributions. We show that this method enables us to reproduce the true mean color-redshift relation when both populations have the same magnitude limit. We also show that this technique allows the inference of redshift distributions for a population fainter than the one of reference and we give an estimate of the color-redshift mapping in this case. This last point is of great interest for future large redshift surveys which suffer from the need of a complete faint spectroscopic sample.

  2. 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.

  3. PIT Coating Requirements Analysis

    International Nuclear Information System (INIS)

    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

  4. Optimal pits and optimal transportation

    OpenAIRE

    Ekeland, Ivar; Queyranne, Maurice

    2014-01-01

    In open pit mining, one must dig a pit, that is, excavate the upper layers of ground before reaching the ore. The walls of the pit must satisfy some geomechanical constraints, in order not to collapse. The question then arises how to mine the ore optimally, that is, how to find the optimal pit. We set up the problem in a continuous (as opposed to discrete) framework, and we show, under weak assumptions, the existence of an optimum pit. For this, we formulate an optimal transportation problem,...

  5. Direct nephrotoxicity of Russell's viper venom demonstrated in the isolated perfused rat kidney.

    Science.gov (United States)

    Ratcliffe, P J; Pukrittayakamee, S; Ledingham, J G; Warrell, D A

    1989-03-01

    Envenoming by Russell's Viper (Vipera russelli) is an important cause of acute renal failure. The mechanism of renal damage is unresolved. It is difficult to obtain evidence of a direct nephrotoxic action because of the coincidental disturbance to the systemic circulation. We studied the action of Russell's Viper venom on the function of the isolated perfused rat kidney. Direct nephrotoxic action was indicated by a dose dependent decrease in inulin clearance and an increase in fractional excretion of sodium seen at venom concentrations down to 50 ng/ml, a concentration likely to be achieved in the human circulation after envenoming. The isolated perfused kidney was also used to assess the efficiency of antivenom and for a comparison with snake venoms from the Thai cobra (Naja kauothia) and the Nigerian Saw-Scaled Viper (Echis ocellatus). PMID:2929855

  6. Galaxy Clusters and Properties in the CFHTLS/VIPERS Survey

    Science.gov (United States)

    Gallego Gallego, Sofia Carolina; Murphy, David; Hyazinth Puzia, Thomas

    2015-08-01

    We present our analysis of clusters in the CFHTLS Wide fields using a red-sequence based cluster finding code. The deep five-band photometry and panoramic coverage permits detection of galaxy clusters between z=0 and z~1 over 132 square degrees. We present a cluster catalogue and optical richness estimates as mass proxies, derived cluster properties from a novel template-fitting analysis and cluster redshift measurements utilizing data from the VLT/VIPERS spectroscopic survey.We complement our analysis with studies of mock cluster catalogues generated from N-body simulation lightcones featuring semi-analytic prescriptions of galaxy formation. These provide us with an insight into the performance of the cluster-finding technique, uncertainties in the derived properties of the detected cluster populations and an important comparison of the popular “lambda” optical richness estimator to known dark matter halo properties.This study serves as the perfect precursor to LSST-depth cluster science, providing an important input into how models describe the evolution of clusters and their members as a function of redshift and mass, and the role high-density environments play in galaxy evolution over half the Hubble time.

  7. Exploring the proteomes of the venoms of the Peruvian pit vipers Bothrops atrox, B. barnetti and B. pictus.

    Science.gov (United States)

    Kohlhoff, Markus; Borges, Marcia H; Yarleque, Armando; Cabezas, Cesar; Richardson, Michael; Sanchez, Eladio F

    2012-04-01

    We report the comparative proteomic characterization of the venoms of Bothrops atrox, B. barnetti and B. pictus. The venoms were subjected to RP-HPLC and the resulting fractions analyzed by SDS-PAGE. The proteins were cut from the gels, digested with trypsin and identified via peptide mass fingerprint and manual sequencing of selected peptides by MALDI-TOF/TOF mass spectrometry. Around 20-25 proteins were identified belonging to only 6-7 protein families. Metalloproteinases of the classes P-I and P-III were the most abundant proteins in all venoms (58-74% based on peak area A214 nm), followed by phospholipases-A(2) (6.4-14%), disintegrins (3.2-9%) and serine proteinases (7-11%), and some of these proteins occurred in several isoforms. In contrast cysteine-rich secretory proteins and L-amino acid oxidases appeared only as single isoforms and were found only in B. atrox and B. barnetti. C-type lectins were also detected in all venoms but at low levels (~ 5%). Furthermore, the venoms contain variable numbers of peptides (Bothrops species is in agreement with their pharmacological and pathological effects. PMID:22300577

  8. Open-pit construction

    International Nuclear Information System (INIS)

    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.)

  9. A mitochondrial DNA phylogeny of the endangered vipers of the Vipera ursinii complex.

    Science.gov (United States)

    Gvoždík, Václav; Jandzik, David; Cordos, Bogdan; Rehák, Ivan; Kotlík, Petr

    2012-03-01

    The last two populations of the Hungarian meadow viper Vipera ursinii rakosiensis were thought to persist in the steppe fragments of Hungary until meadow vipers were discovered in central Romania (Transylvania), suggesting a possible existence of remnant populations elsewhere. We assessed the phylogenetic position of the Transylvanian vipers using 2030 bp of mitochondrial DNA sequence. We showed that they were closely related to the Hungarian vipers, while those from northeastern Romania (Moldavia) and Danube Delta belonged to the subspecies Vipera ursinii moldavica. Montane subspecies from Europe (Vipera ursinii ursinii and Vipera ursinii macrops) formed a sister clade to the two lowland subspecies. Vipera renardi formed a sister clade to V. ursinii, with populations from the Greater Caucasus (Vipera renardi lotievi) and Tien Shan (Vipera renardi tienshanica) as the sister group to Vipera renardi renardi, and Vipera renardi eriwanensis from the Lesser Caucasus as the most basal taxon in the species. Our results illustrate that the divergence between the lowland and montane populations occurred separately in each species and several times in V. renardi. We demonstrated that the recently discovered Transylvanian population is the third surviving population of V. u. rakosiensis and the only known population outside of Hungary. PMID:22182992

  10. Individual Growth Rates of Nikolsky’s Viper, Vipera berus nikolskii (Squamata, Viperidae

    Directory of Open Access Journals (Sweden)

    Bondarenko Z. S.

    2016-02-01

    Full Text Available Capture-mark-recapture data was used to infer growth rates of the Nikolsky’s viper, Vipera berus nikolskii (Vedmederja, Grubant et Rudaeva, 1986, in the Eastern Ukraine. We have found that growth rate is negatively correlated with age. The difference in growth rates before maturation is not significant between different sexes. Growth rates decrease rapidly after maturation in males and females, however adult males retain significantly higher average growth rates. There is large dispersion of growth rates in the group of adult females, which is caused, probably, by alteration of complete arrest of growth in the years with reproduction and more intensive growth in the years without it. Asymptotic snout-ventral length estimated after Von Bertalanffy model was 680 mm in females and 630 mm in males. Females mature after fifth and males mature after fourth hibernation. The larger females in vipers can not be the result of higher growth rates in females, but are the outcome of a combination of other factors including different maturation time and size (older and being larger, and, perhaps, longer life span due to lower mortality. Growth rates of the Nikolsky’s viper in the nature are higher than in other species in the group of small Eurasian vipers.

  11. Cloning of a prothrombin activator-like metalloproteinase from the West African saw-scaled viper, Echis ocellatus.

    Science.gov (United States)

    Hasson, S S; Theakston, R D G; Harrison, R A

    2003-11-01

    Systemic envenoming by the saw-scaled viper, Echis ocellatus, is responsible for more deaths than any other snake in West Africa. Despite its medical importance, there have been few investigations into the toxin composition of the venom of this viper. Here we describe the isolation of E. ocellatus venom gland cDNAs encoding a protein of 514 amino acids that showed 91% sequence similarity to Ecarin, a prothrombin-activating metalloproteinase from the venom of the East African viper, E. pyramidum leakeyi, that induces severe consumption coagulopathy. Structural similarities between the E. ocellatus metalloproteinase and analogues in venoms of related vipers suggest that antibodies raised to phylogenetically conserved E. ocellatus metalloproteinase domains may have potential for cross-specific and cross-generic neutralisation of analogous venom toxins. PMID:14602118

  12. Life threatening intracerebral haemorrhage following saw- scaled viper (Echis carinatus) envenoming-authenticated case report from Sri Lanka

    OpenAIRE

    Fonseka, Chathuranga Lakmal; jeevagan, Vijayabala; Gnanathasan, Christeine Ariaranee

    2013-01-01

    Background Echis carinatus (Saw scaled viper {SSV}) is a venomous snake found in the parts of Middle East and Central Asia. SSV envenoming is characterized by local swelling and coagulopathy. Various bleeding manifestations are commonly seen with SSV envenoming. In contrast to other part of Asia, saw scale viper envenoming has not been reported to cause life threatening haemorrhagic manifestations in Sri Lanka. Case presentation We report a 19 years old healthy boy who developed massive left ...

  13. Comet 67P's Pitted Surface

    Science.gov (United States)

    Kohler, Susanna

    2015-11-01

    High-resolution imagery of comet 67P ChuryumovGerasimenko has revealed that its surface is covered in active pits some measuring hundreds of meters both wide and deep! But what processes caused these pits to form?Pitted LandscapeESAs Rosetta mission arrived at comet 67P in August 2014. As the comet continued its journey around the Sun, Rosetta extensively documented 67Ps surface through high-resolution images taken with the on-board instrument NavCam. These images have revealed that active, circular depressions are a common feature on the comets surface.In an attempt to determine how these pits formed, an international team of scientists led by Olivier Mousis (Laboratory of Astrophysics of Marseille) has run a series of simulations of a region of the comet the Seth region that contains a 200-meter-deep pit. These simulations include the effects of various phase transitions, heat transfer through the matrix of ices and dust, and gas diffusion throughout the porous material.Escaping VolatilesAdditional examples of pitted areas on 67Ps northern-hemisphere surface include the Ash region and the Maat region (both imaged September 2014 by NavCam) [Mousis et al. 2015]Previous studies have already eliminated two potential formation mechanisms for the pits: impacts (the sizes of the pits werent right) and erosion due to sunlight (the pits dont have the right shape). Mousis and collaborators assume that the pits are instead caused by the depletion of volatile materials chemical compounds with low boiling points either via explosive outbursts at the comets surface, or via sinkholes opening from below the surface. But what process causes the volatiles to deplete when the comet heats?The authors simulations demonstrate that volatiles trapped beneath the comets surface either in icy structures called clathrates or within amorphous ice can be suddenly released as the comet warms up. The team shows that the release of volatiles from these two structures can create 200-meter

  14. Dilute Russell's viper venom and activated partial thromboplastin time in lupus anticoagulant diagnosis: is mixing essential?

    Science.gov (United States)

    Chandrashekar, Vani

    2016-06-01

    Dilute Russell's viper venom (DRVV) testing and activated partial thromboplastin time (APTT) have been effectively used in combination for lupus anticoagulant testing. The purpose of our study was to evaluate the role of mixing in activated partial thromboplastin and dilute Russell's viper venom testing for evaluation of lupus anticoagulants. Citrated blood from patients who were not on oral anticoagulant therapy was studied. Mixing study with 1 : 1 normal plasma for elevated APTT and also few samples with elevated screen time was carried out. Elevated APTT was seen in only 48.1% of patients with lupus anticoagulant. Correction of APTT was seen in 27.8% of lupus anticoagulant-positive patients. DRVV test on mixing resulted in 83.8% false-negative values. Integrated DRVV test could be a standalone test for testing lupus anticoagulant. Mixing study may be restricted for patients on oral anticoagulants or patients with strong lupus anticoagulant. PMID:26626041

  15. On the issue of taxonomical status of steppe viper (Vipera renardi in Right-bank Ukraine

    Directory of Open Access Journals (Sweden)

    A. L. Baybuz

    2011-07-01

    Full Text Available Data on morphologic variability of the steppe viper in the Kirovograd region (Right-bank Ukraine are given firstly. Tentative estimation of the similaritylevel of the local population and the populations from the Left-bank Ukraine and the Crimea was carried out using methods of the multivariate statistics. Morphological data in line with the results of mitochondrial DNA analysis show that the population in the Kirovograd region belongs to widespread Eurasian species Vipera renardiand morphologically most close to the original populations of the lowland Crimea, Sivash and Forest-Steppe of the Left-bank Ukraine. This could indicate the complicated history of the Right-bank Ukraine colonization by the steppe viper and possible influence of environmental conditions on the vipers’ morphology

  16. Purification and characterization of an organ specific haemorrhagic toxin from Vipera russelli russelli (Russell's viper) venom.

    Science.gov (United States)

    Kole, L; Chakrabarty, D; Datta, K; Bhattacharyya, D

    2000-04-01

    A haemorrhagic toxin (VRR-12) from Vipera russelli russelli (Russell's viper) venom has been purified by ion-exchange chromatography on CM-Sephadex C-50 followed by size-exclusion HPLC to electrophoretically homogeneous state. It is a 12 kDa single polypeptide having 1 mole of Zn+2 ion. This toxin induces intense intestinal haemorrhage and to a lesser extent skeletal muscle haemorrhage in mice. It does not show detectable proteolytic and esterolytic activity with selected substrates under specified conditions, haemolytic and phospholipase activity. When VRR-12, preincubated with bivalent antiserum against Saw-scaled and Russell's viper venom or EDTA was injected, haemorrhagic activity was not reduced, on the other hand preincubation with phenylmethyl sulphonyl fluoride reduced the activity markedly. Biodistribution studies with 125I VRR-12 show that haemorrhagic manifestation by this toxin is not a direct function of the fraction of the totally administered toxin distributed to that tissue. PMID:10983422

  17. Acute myocardial infarction and cerebrovascular accident in a young girl after a viper bite.

    OpenAIRE

    Aravanis, C; Ioannidis, P J; Ktenas, J

    1982-01-01

    A 17-year-old girl developed an acute myocardial infarction immediately after being bitten by a viper and four days later she had a cerebrovascular accident. The close clinical and laboratory follow-up of this case suggested that myocardial damage could be attributed to a direct cardiotoxic effect of the venom, while the brain injury that subsequently appeared was probably the result of a disseminated intravascular coagulopathy, possibly in conjunction with vasculitis.

  18. Measurements of the Physics Characteristics of the Fast Pulsed Reactor, VIPER

    International Nuclear Information System (INIS)

    The VIPER pulsed reactor was first made critical on 26 May 1967. The physics measurements carried out during its subsequent commissioning to prompt critical are described. These experiments include the measurement of reaction rate distributions, perturbation effects, neutron spectrum, neutron lifetime, and prompt temperature coefficients of reactivity. The measured characteristics of prompt critical transients are compared with predictions based on calculated expansion and Doppler effects. (author)

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

    International Nuclear Information System (INIS)

    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

  20. On a meeting between the Horn Viper and a Centipede in the Peloponnese, southern Greece  or the Biter, bit

    DEFF Research Database (Denmark)

    Tan, Kit; Kretzschmar, Horst

    2009-01-01

    Vipera ammodytes L., (the European Horn-Nosed Viper) is a small venomous snake occurring in southern L., (the European Horn-Nosed Viper) is a small venomous snake occurring in southern Europe. It was documented attacking Scolopendra cingulata Latreille (the venomous Mediterranean Banded Centipede...

  1. Development of VIPER: a simulator for assessing vision performance of warfighters

    Science.gov (United States)

    Familoni, Jide; Thompson, Roger; Moyer, Steve; Mueller, Gregory; Williams, Tim; Nguyen, Hung-Quang; Espinola, Richard L.; Sia, Rose K.; Ryan, Denise S.; Rivers, Bruce A.

    2016-05-01

    Background: When evaluating vision, it is important to assess not just the ability to read letters on a vision chart, but also how well one sees in real life scenarios. As part of the Warfighter Refractive Eye Surgery Program (WRESP), visual outcomes are assessed before and after refractive surgery. A Warfighter's ability to read signs and detect and identify objects is crucial, not only when deployed in a military setting, but also in their civilian lives. Objective: VIPER, a VIsion PERformance simulator was envisioned as actual video-based simulated driving to test warfighters' functional vision under realistic conditions. Designed to use interactive video image controlled environments at daytime, dusk, night, and with thermal imaging vision, it simulates the experience of viewing and identifying road signs and other objects while driving. We hypothesize that VIPER will facilitate efficient and quantifiable assessment of changes in vision and measurement of functional military performance. Study Design: Video images were recorded on an isolated 1.1 mile stretch of road with separate target sets of six simulated road signs and six objects of military interest, separately. The video footage were integrated with customdesigned C++ based software that presented the simulated drive to an observer on a computer monitor at 10, 20 or 30 miles/hour. VIPER permits the observer to indicate when a target is seen and when it is identified. Distances at which the observer recognizes and identifies targets are automatically logged. Errors in recognition and identification are also recorded. This first report describes VIPER's development and a preliminary study to establish a baseline for its performance. In the study, nine soldiers viewed simulations at 10 miles/hour and 30 miles/hour, run in randomized order for each participant seated at 36 inches from the monitor. Relevance: Ultimately, patients are interested in how their vision will affect their ability to perform daily

  2. 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.

  3. Development of venom toxin-specific antibodies by DNA immunisation: rationale and strategies to improve therapy of viper envenoming.

    Science.gov (United States)

    Harrison, R A

    2004-04-16

    DNA vaccination induces potent cellular immune responses against infectious and parasitic intracellular pathogens. This paper illustrates that DNA immunisation protocols can be adapted to induce high titre antibody responses with potential to improve the treatment of systemic snake envenoming that kills 20000 people annually in Africa. Envenoming by the saw-scaled vipers and puff adders are responsible for the majority of these deaths. DNA sequences encoding haemorrhagic, pro- and anti-coagulant and other haemostasis-disruptive venom toxins from these vipers showed extensive cross-specific and cross-generic sequence and structural similarities. The predicted antigenic profiles of these toxin sequences are utilised to design DNA immunisation constructs to generate toxin-specific antibodies with potential to polyspecifically neutralise venoms from the most medically-important African vipers. PMID:15068847

  4. Venom of Indian monocellate cobra and Russell's viper show anticancer activity in experimental models.

    Science.gov (United States)

    Debnath, Anindita; Chatterjee, Uttora; Das, Minati; Vedasiromoni, Joseph R; Gomes, Aparna

    2007-05-22

    Indian monocellate cobra (Naja kaouthia) and Russell's viper (Vipera russelli) are common snakes of the East Indian sub-peninsula. The anticarcinogenic activities of their crude venoms were studied on carcinoma, sarcoma and leukemia models. Sub-lethal doses of venoms showed cytotoxicity on Ehrlich ascites carcinoma (EAC) cells in vivo. The venoms increased lifespan of EAC mice and strengthened the impaired host antioxidant system. Sarcoma formation in mice (3-methylcholanthrene induced) after venom treatment was significantly less (p venoms displayed potent cytotoxic and apoptogenic effect on human leukemic cells (U937/K562). The venoms reduced cell proliferation rate (p venoms may be attributed to the difference in their constituents. PMID:17258413

  5. The VIMOS Public Extragalactic Redshift Survey (VIPERS). A Support Vector Machine classification of galaxies, stars and AGNs

    CERN Document Server

    Malek, K; Pollo, A; Fritz, A; Garilli, B; Scodeggio, M; Iovino, A; Granett, B R; Abbas, U; Adami, C; Arnouts, S; Bel, J; Bolzonella, M; Bottini, D; Branchini, E; Cappi, A; Coupon, J; Cucciati, O; Davidzon, I; De Lucia, G; de la Torre, S; Franzetti, P; Fumana, M; Guzzo, L; Ilbert, O; Krywult, J; Brun, V Le; Fevre, O Le; Maccagni, D; Marulli, F; McCracken, H J; Paioro, L; Polletta, M; Schlagenhaufer, H; Tasca, L A M; Tojeiro, R; Vergani, D; Zanichelli, A; Burden, A; Di Porto, C; Marchetti, A; Marinoni, C; Mellier, Y; Moscardini, L; Nichol, R C; Peacock, J A; Percival, W J; Phleps, S; Wolk, M; Zamorani, G

    2013-01-01

    The aim of this work is to develop a comprehensive method for classifying sources in large sky surveys and we apply the techniques to the VIMOS Public Extragalactic Redshift Survey (VIPERS). Using the optical (u*, g', r', i') and NIR data (z', Ks), we develop a classifier for identifying stars, AGNs and galaxies improving the purity of the VIPERS sample. Support Vector Machine (SVM) supervised learning algorithms allow the automatic classification of objects into two or more classes based on a multidimensional parameter space. In this work, we tailored the SVM for classifying stars, AGNs and galaxies, and applied this classification to the VIPERS data. We train the SVM using spectroscopically confirmed sources from the VIPERS and VVDS surveys. We tested two SVM classifiers and concluded that including NIR data can significantly improve the efficiency of the classifier. The self-check of the best optical + NIR classifier has shown a 97% accuracy in the classification of galaxies, 97 for stars, and 95 for AGNs ...

  6. The VIMOS Public Extragalactic Redshift Survey (VIPERS). Hierarchical scaling and biasing

    Science.gov (United States)

    Cappi, A.; Marulli, F.; Bel, J.; Cucciati, O.; Branchini, E.; de la Torre, S.; Moscardini, L.; Bolzonella, M.; Guzzo, L.; Abbas, U.; Adami, C.; Arnouts, S.; Bottini, D.; Coupon, J.; Davidzon, I.; De Lucia, G.; Fritz, A.; Franzetti, P.; Fumana, M.; Garilli, B.; Granett, B. R.; Ilbert, O.; Iovino, A.; Krywult, J.; Le Brun, V.; Le Fèvre, O.; Maccagni, D.; Małek, K.; McCracken, H. J.; Paioro, L.; Polletta, M.; Pollo, A.; Scodeggio, M.; Tasca, L. A. M.; Tojeiro, R.; Vergani, D.; Zanichelli, A.; Burden, A.; Di Porto, C.; Marchetti, A.; Marinoni, C.; Mellier, Y.; Nichol, R. C.; Peacock, J. A.; Percival, W. J.; Phleps, S.; Schimd, C.; Schlagenhaufer, H.; Wolk, M.; Zamorani, G.

    2015-07-01

    Aims: Building on the two-point correlation function analyses of the VIMOS Public Extragalactic Redshift Survey (VIPERS), we investigate the higher-order correlation properties of the same galaxy samples to test the hierarchical scaling hypothesis at z ~ 1 and the dependence on galaxy luminosity, stellar mass, and redshift. With this work we also aim to assess possible deviations from the linearity of galaxy bias independently from a previously performed analysis of our survey. Methods: We have measured the count probability distribution function in spherical cells of varying radii (3 ≤ R ≤ 10 h-1 Mpc), deriving σ8g (the galaxy rms at 8 h-1 Mpc), the volume-averaged two-, three-, and four-point correlation functions and the normalized skewness S3g and kurtosis S4g for different volume-limited subsamples, covering the following ranges: -19.5 ≤ MB(z = 1.1) - 5log (h) ≤ -21.0 in absolute magnitude, 9.0 ≤ log (M∗/M⊙h-2) ≤ 11.0 in stellar mass, and 0.5 ≤ zDeep Survey (VVDS). We measure the lowest bias b = 1.47 ± 0.18 for galaxies with MB(z = 1.1) - 5log (h) ≤ -19.5 in the first redshift bin (0.5 ≤ zweb site is http://www.vipers.inaf.it

  7. Echistatin. A potent platelet aggregation inhibitor from the venom of the viper, Echis carinatus.

    Science.gov (United States)

    Gan, Z R; Gould, R J; Jacobs, J W; Friedman, P A; Polokoff, M A

    1988-12-25

    A 49-residue protein, echistatin, which inhibits platelet aggregation, was purified from the venom of the saw-scaled viper Echis carinatus. The purification procedure included gel filtration on Sephadex G-50, cation-exchange chromatography on Mono S, and C18 reverse-phase high pressure liquid chromatography. The purified protein was homogeneous as judged by polyacrylamide gel electrophoresis, isoelectric focusing, reverse-phase high pressure liquid chromatography, and NH2-terminal sequence analysis. Echistatin is a single-chain polypeptide with a molecular weight of 5400 and a native isoelectric point of 8.3. The most abundant amino acid, cysteine, accounts for 8 of the 49 residues in the protein. A 10-residue segment of echistatin shows 90% identity to a portion of the sequence of trigramin, a platelet aggregation inhibitor from the green tree viper Trimereserus gramineus (Huang, T.-F., Holt, J. C., Lukasiewicz, H., and Niewiarowski, S. (1987) J. Biol. Chem. 262, 16157-16163). Echistatin contains the sequence arginine-glycine-aspartic acid, which is common to proteins which bind to the glycoprotein IIb/IIIa complex. It also contains the sequence proline-arginine-asparagine-proline, which is found in the A alpha chain of human fibrinogen at position 267-270. The purified protein inhibits fibrinogen-dependent platelet aggregation initiated by ADP with an IC50 of 3 x 10(-8) M and also prevents aggregation initiated by thrombin, epinephrine, collagen, or platelet-activating factor. Reduction of echistatin abolished its inhibitory activity. PMID:3198653

  8. Recent advances in phylogeny and taxonomy of Near and Middle Eastern Vipers – an update

    Directory of Open Access Journals (Sweden)

    Nikolaus Stümpel

    2009-12-01

    Full Text Available The number of recognized viper species in the Near and Middle East has been raised significantly in the last 25 years (Table 1. While some smaller genera remained more or less stable, the genus Vipera has been subdivided into four genera on the basis of molecular genetic data. Of these genera, Daboia contains the former Vipera palaestinae and D. russelii, Macrovipera the species M. lebetina, M. schweizeri and an undescribed, basal species from Iran, and Montivipera the former Vipera xanthina and V. raddei complexes. While the genetic diversity in the M. raddei complex is fairly low, it is high in the M. xanthina complex. This may give reason to synonymize several taxa in the M. raddei complex, while new taxa can be described in the Turkish M. xanthina complex. The number of known species in the Middle Eastern Saw-scaled vipers (genus Echis must be raised from 2 to 6. These species belong to 3 different species complexes (an Asian, an African and an Arabian complex. A particularly high diversity of Echis is found in southern Arabia. Antivenom producers should pay particular attention to new species in the medically important genera Echis and Macrovipera.

  9. The VIMOS Public Extragalactic Redshift Survey (VIPERS). Star formation history of passive galaxies

    CERN Document Server

    Siudek, M; Scodeggio, M; Garilli, B; Pollo, A; Haines, C P; Fritz, A; Bolzonella, M; de la Torre, S; Granett, B R; Guzzo, L; Abbas, U; Adami, C; Bottini, D; Cappi, A; Cucciati, O; De Lucia, G; Davidzon, I; Franzetti, P; Iovino, A; Krywult, J; Brun, V Le; Fèvre, O Le; Maccagni, D; Marchetti, A; Marulli, F; Polletta, M; Tasca, L A M; Tojeiro, R; Vergani, D; Zanichelli, A; Arnouts, S; Bel, J; Branchini, E; Ilbert, O; Gargiulo, A; Moscardini, L; Takeuchi, T T; Zamorani, G

    2016-01-01

    We trace the evolution and the star formation history of passive galaxies, using a subset of the VIMOS Public Extragalactic Redshift Survey (VIPERS). We extracted from the VIPERS survey a sample of passive galaxies in the redshift range 0.4

  10. Haemostasis disorders caused by envenomation by Cerastes cerastes and Macrovipera mauritanica vipers.

    Science.gov (United States)

    Fahmi, Laila; Makran, Bouchra; Boussadda, Lotfi; Lkhider, Mustapha; Ghalim, Noreddine

    2016-06-15

    Viper venoms are a real source of proteolytic enzymes causing clotting, bleeding, edema, necrosis, hemorrhage, pain at the bite site and systemic changes. This study was conducted to evaluate the changes induced in hematological and haemostatic parameters in rabbits after 1, 3, 6 and 24 h post-venom of subcutaneously administration of a sublethal dose of Cerastes cerastes and Macrovipera mauritanica venoms. Our results indicated that most hematological and haemostatic parameters showed significant changes 3 and 6 h after envenomation. The hemoglobin, hematocrit, red blood cells, platelets and prothrombin time were reduced significantly 3 h after envenomation. A very significant increase in the levels of white blood cells, lymphocytes, monocytes, activated thromboplastin time and fibrinogen were recorded 6 h following envenomation. However, no significant difference was found for the mean corpuscular volume, corpuscular hemoglobin content and mean corpuscular hemoglobin concentration throughout the whole duration of the experiment. These results suggest that severe hematological and haemostatic changes may be initiated during the early stages of envenomation leading to local and systemic hemorrhages and coagulopathies which are the main cause of death in case of vipers envenomation. PMID:26724273

  11. The VIMOS Public Extragalactic Redshift Survey (VIPERS). A support vector machine classification of galaxies, stars, and AGNs

    Science.gov (United States)

    Małek, K.; Solarz, A.; Pollo, A.; Fritz, A.; Garilli, B.; Scodeggio, M.; Iovino, A.; Granett, B. R.; Abbas, U.; Adami, C.; Arnouts, S.; Bel, J.; Bolzonella, M.; Bottini, D.; Branchini, E.; Cappi, A.; Coupon, J.; Cucciati, O.; Davidzon, I.; De Lucia, G.; de la Torre, S.; Franzetti, P.; Fumana, M.; Guzzo, L.; Ilbert, O.; Krywult, J.; Le Brun, V.; Le Fevre, O.; Maccagni, D.; Marulli, F.; McCracken, H. J.; Paioro, L.; Polletta, M.; Schlagenhaufer, H.; Tasca, L. A. M.; Tojeiro, R.; Vergani, D.; Zanichelli, A.; Burden, A.; Di Porto, C.; Marchetti, A.; Marinoni, C.; Mellier, Y.; Moscardini, L.; Nichol, R. C.; Peacock, J. A.; Percival, W. J.; Phleps, S.; Wolk, M.; Zamorani, G.

    2013-09-01

    Aims: The aim of this work is to develop a comprehensive method for classifying sources in large sky surveys and to apply the techniques to the VIMOS Public Extragalactic Redshift Survey (VIPERS). Using the optical (u∗,g',r',i') and near-infrared (NIR) data (z', Ks), we develop a classifier, based on broad-band photometry, for identifying stars, active galactic nuclei (AGNs), and galaxies, thereby improving the purity of the VIPERS sample. Methods: Support vector machine (SVM) supervised learning algorithms allow the automatic classification of objects into two or more classes based on a multidimensional parameter space. In this work, we tailored the SVM to classifying stars, AGNs, and galaxies and applied this classification to the VIPERS data. We trained the SVM using spectroscopically confirmed sources from the VIPERS and VVDS surveys. Results: We tested two SVM classifiers and concluded that including NIR data can significantly improve the efficiency of the classifier. The self-check of the best optical + NIR classifier has shown 97% accuracy in the classification of galaxies, 97% for stars, and 95% for AGNs in the 5-dimensional colour space. In the test of VIPERS sources with 99% redshift confidence, the classifier gives an accuracy equal to 94% for galaxies, 93% for stars, and 82% for AGNs. The method was applied to sources with low-quality spectra to verify their classification, hence increasing the security of measurements for almost 4900 objects. Conclusions: We conclude that the SVM algorithm trained on a carefully selected sample of galaxies, AGNs, and stars outperforms simple colour-colour selection methods and can be regarded as a very efficient classification method particularly suitable for modern large surveys. Based on observations collected at the European Southern Observatory, Cerro Paranal, Chile, using the Very Large Telescope under programme 182.A-0886 and partly 070.A-9007. Also based on observations obtained with MegaPrime/MegaCam, a joint

  12. 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.

  13. Conditions of growth of open corrosion pits in stainless steels -- Electrochemical experiments on model pits

    Energy Technology Data Exchange (ETDEWEB)

    Hakkarainen, T.J. [VTT Manufacturing Technology (Finland)

    1998-12-31

    The effects of the most important variables on continued growth and repassivation of open macroscopic corrosion pits in stainless steel sheets were investigated using two different artificial pit configurations. The pit growth was activated under anodic polarization either by injecting concentrated chloride solution into the pit or by initially filling the pit with chromic chloride crystals (CrCl{sub 3}-6H{sub 2}O). Experiments were made on sheet specimens of stainless steels of type UNS S31603 (316L) or UNS S312.54 in bulk solutions containing chloride and/or sulfate ions. Various aspects of the test arrangements and pitting of stainless steels are discussed, including the electrolyte composition within the pits, repassivation potentials and the IR-drops associated with pit growth. It is demonstrated that using the artificial pit configurations the effects of the main variables affecting the conditions for growth and repassivation of open corrosion pits can be investigated quantitatively, including electrode potentials, temperature, and composition of the bulk solution. It is concluded that for continued growth of corrosion pits with ``large`` openings to the bulk solution, a strongly oxidizing environment is required, and that sulfate ions in amounts comparable to or in excess of that of chloride ions may stabilize pit growth.

  14. 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…

  15. NV - Assessment of wildlife hazards associated with mine pit lakes

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Several open pit mines in Nevada lower groundwater to mine ore below the water table. After mining, the pits partially fill with groundwater to form pit lakes....

  16. Sequence diversity and ligand-induced structural rearrangements of viper hyaluronidase.

    Science.gov (United States)

    Bharathi, A Christian; Yadav, Pradeep Kumar; Syed Ibrahim, B

    2016-04-01

    Hyaluronidases (Hyals) are a class of carbohydrate-active enzyme involved in angiogenesis, cancer proliferation, tumour growth and venom spreading. Functionally significant Hyals are responsible for the fast spreading of venom to the target site of action. The absence of molecular diversity and the structural and functional behaviour of snake venom Hyals was the inspiration for the objective of this study. Echis pyramidum leakeyi hyaluronidase (EHY)-based phylogenetic analysis showed the existence of two functional groups of Hyals which had diverged from the coral snake (the ancestor). The structure was modelled and it was found that the E-loop region (211-224 AA) was only present in EHY compared to the templates which may account for the significant function of viper Hyal. The best interacting ligands were screened from the selected plant derivatives and MYR consisted of better pharmacophore features (AADDRRR) in comparison with other ligands. Furthermore, the HOMO, LUMO, and MO energies and energy gaps of CGA, MIM and MYR were calculated by DFT analysis. EHY-ligand complex stability and interactions were investigated through MD simulation and FEL analysis. These revealed that MIM and MYR or their derivative compounds could be prominent lead molecules for both EHY and other eukaryotic Hyals. PCA analysis of both the non-ligated and ligated forms confirmed that loop-III (86-96 AA) and E-loop region structural rearrangements were essential for the association and dissociation process of the substrate. Particularly, ARG92 and LYS219 are determined as important key residues from the conformational changes. These regions' dynamic behaviour can be associated with HA binding and the catalytic function of EHY. This result can extend our knowledge of viper Hyal functional behaviour and provides structural insight to target eukaryotic Hyals as forthcoming drug targets in cancer treatment and venom spreading. PMID:26867694

  17. The VIMOS Public Extragalactic Redshift Survey (VIPERS). Never mind the gaps: comparing techniques to restore homogeneous sky coverage

    Science.gov (United States)

    Cucciati, O.; Granett, B. R.; Branchini, E.; Marulli, F.; Iovino, A.; Moscardini, L.; Bel, J.; Cappi, A.; Peacock, J. A.; de la Torre, S.; Bolzonella, M.; Guzzo, L.; Polletta, M.; Fritz, A.; Adami, C.; Bottini, D.; Coupon, J.; Davidzon, I.; Franzetti, P.; Fumana, M.; Garilli, B.; Krywult, J.; Małek, K.; Paioro, L.; Pollo, A.; Scodeggio, M.; Tasca, L. A. M.; Vergani, D.; Zanichelli, A.; Di Porto, C.; Zamorani, G.

    2014-05-01

    Aims: Non-uniform sampling and gaps in sky coverage are common in galaxy redshift surveys, but these effects can degrade galaxy counts-in-cells measurements and density estimates. We carry out a comparative study of methods that aim to fill the gaps to correct for the systematic effects. Our study is motivated by the analysis of the VIMOS Public Extragalactic Redshift Survey (VIPERS), a flux-limited survey at iAB effectively separate under-dense from over-dense regions by considering cells in the 1st and 5th quintiles of the probability distribution of the observed counts. Conclusions: We show that despite systematic uncertainties, it is possible to reconstruct the lowest and highest density environments on scales of 5 h-1 Mpc at moderate redshifts 0.5 ≲ z ≲ 1.1, over a large volume such as the one covered by the VIPERS survey. This is vital for characterising cosmic variance and rare populations (e.g, brightest galaxies) in environmental studies at these redshifts. Based on observations collected at the European Southern Observatory, Cerro Paranal, Chile, using the Very Large Telescope under programs 182.A-0886 and partly 070.A-9007. Also based on observations obtained with MegaPrime/MegaCam, a joint project of CFHT and CEA/DAPNIA, at the Canada-France-Hawaii Telescope (CFHT), which is operated by the National Research Council (NRC) of Canada, the Institut National des Sciences de l'Univers, of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii. This work is based in part on data products produced at TERAPIX and the Canadian Astronomy Data Centre as part of the Canada-France-Hawaii Telescope Legacy Survey, a collaborative project of NRC and CNRS. The VIPERS website is http://www.vipers.inaf.it/Appendix A is available in electronic form at http://www.aanda.org

  18. The VIMOS Public Extragalactic Redshift Survey (VIPERS). On the recovery of the count-in-cell probability distribution function

    Science.gov (United States)

    Bel, J.; Branchini, E.; Di Porto, C.; Cucciati, O.; Granett, B. R.; Iovino, A.; de la Torre, S.; Marinoni, C.; Guzzo, L.; Moscardini, L.; Cappi, A.; Abbas, U.; Adami, C.; Arnouts, S.; Bolzonella, M.; Bottini, D.; Coupon, J.; Davidzon, I.; De Lucia, G.; Fritz, A.; Franzetti, P.; Fumana, M.; Garilli, B.; Ilbert, O.; Krywult, J.; Le Brun, V.; Le Fèvre, O.; Maccagni, D.; Małek, K.; Marulli, F.; McCracken, H. J.; Paioro, L.; Polletta, M.; Pollo, A.; Schlagenhaufer, H.; Scodeggio, M.; Tasca, L. A. M.; Tojeiro, R.; Vergani, D.; Zanichelli, A.; Burden, A.; Marchetti, A.; Mellier, Y.; Nichol, R. C.; Peacock, J. A.; Percival, W. J.; Phleps, S.; Wolk, M.

    2016-04-01

    We compare three methods to measure the count-in-cell probability density function of galaxies in a spectroscopic redshift survey. From this comparison we found that, when the sampling is low (the average number of object per cell is around unity), it is necessary to use a parametric method to model the galaxy distribution. We used a set of mock catalogues of VIPERS to verify if we were able to reconstruct the cell-count probability distribution once the observational strategy is applied. We find that, in the simulated catalogues, the probability distribution of galaxies is better represented by a Gamma expansion than a skewed log-normal distribution. Finally, we correct the cell-count probability distribution function from the angular selection effect of the VIMOS instrument and study the redshift and absolute magnitude dependency of the underlying galaxy density function in VIPERS from redshift 0.5 to 1.1. We found a very weak evolution of the probability density distribution function and that it is well approximated by a Gamma distribution, independently of the chosen tracers. Based on observations collected at the European Southern Observatory, Cerro Paranal, Chile, using the Very Large Telescope under programmes 182.A-0886 and partly 070.A-9007. Also based on observations obtained with MegaPrime/MegaCam, a joint project of CFHT and CEA/DAPNIA, at the Canada-France-Hawaii Telescope (CFHT), which is operated by the National Research Council (NRC) of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii. This work is based in part on data products produced at TERAPIX and the Canadian Astronomy Data Centre as part of the Canada-France-Hawaii Telescope Legacy Survey, a collaborative project of NRC and CNRS. The VIPERS web site is http://www.vipers.inaf.it/

  19. Pitting corrosion on a copper canister

    International Nuclear Information System (INIS)

    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

  20. Examination of pitting by scanning electrochemical microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Polkinghorne, J.C.; Still, J.W.; Wipf, D.O.

    1995-12-01

    The objective of this research project was to investigate the initiation and formation of localized corrosion pits on stainless steel samples. By using a scanning electrochemical microscope (SECM), the effects of varying Cl{sup -} concentration, pH, and sample potential on these processes were studied. Initiation and growth of single pits were attained by using the SECM tip to electrogenerate Cl{sup -} in an extremely small area on a metal sample, thus forming localized pits. Imaging of the sample surface was achieved via detection of surface conductivity by the SECM.

  1. Floating Lid Constructions for Pit Water Storage

    DEFF Research Database (Denmark)

    Heller, Alfred

    1997-01-01

    Seasonal storage is necessary if renewable heat sources are to be applied on a large scale. Pit water storage seems to be a cheaper alternative to steel tank storage. The lid price is the largest component of a pit water store with a cost share of about 60% of the total storage cost. Due to the...... large share in price the development of lid constructions is crucial for the development of pit water storage and seasonal storage.The current report gives a survey of the most important established and planned designs from Denmark, Sweden and Germany....

  2. Detection of venom after antivenom is not associated with persistent coagulopathy in a prospective cohort of Russell's viper (Daboia russelii envenomings.

    Directory of Open Access Journals (Sweden)

    Kalana Maduwage

    2014-12-01

    Full Text Available Venom recurrence or persistence in the circulation after antivenom treatment has been documented many times in viper envenoming. However, it has not been associated with clinical recurrence for many snakes, including Russell's viper (Daboia spp.. We compare the recovery of coagulopathy to the recurrence or persistence of venom in patients with Russell's viper envenoming.The study included patients with Russell's viper (D. russelii envenoming presenting over a 30 month period who had Russell's viper venom detected by enzyme immunoassay. Demographics, information on the snake bite, and clinical effects were collected for all patients. All patients had serum collected for venom specific enzyme immunoassay and citrate plasma to measure fibrinogen levels and prothrombin time (international normalised ratio; INR. Patients with venom recurrence/persistence were compared to those with no detectable recurrence of venom. There were 55 patients with confirmed Russell's viper envenoming and coagulopathy with low fibrinogen concentrations: 31 with venom recurrence/persistence, and 24 with no venom detected post-antivenom. Fibrinogen concentrations increased and INR decreased after antivenom in both the recurrence and non-recurrence patients. Clinical features, laboratory parameters, antivenom dose and length of hospital were similar for both groups. Pre-antivenom venom concentrations were higher in patients with venom recurrence/persistence with a median venom concentration of 385 ng/mL (16-1521 ng/mL compared to 128 ng/mL (14-1492 ng/mL; p = 0.008.Recurrence of Russell's viper venom was not associated with a recurrence of coagulopathy and length of hospital stay. Further work is required to determine if the detection of venom recurrence is due to the venom specific enzyme immunoassay detecting both venom-antivenom complexes as well as free venom.

  3. The VIPERS Multi-Lambda Survey - I: UV and NIR Observations, multi-color catalogs and photometric redshifts

    CERN Document Server

    Moutard, T; Ilbert, O; Coupon, J; Hudelot, P; Vibert, D; Comte, V; Conseil, S; Davidzon, I; Guzzo, L; Llebaria, A; Martin, C; McCracken, H J; Milliard, B; Morrison, G E; Schiminovich, D; Treyer, M; Van Werbaeke, L

    2016-01-01

    We present observations collected in the CFHTLS-VIPERS region in the ultraviolet (UV) with the GALEX satellite (far and near UV channels) and the near infrared with the CFHT/WIRCam camera ($K_s$-band) over an area of 22 and 27 deg$^2$, respectively. The depth of the photometry was optimized to measure the physical properties (e.g., SFR, stellar masses) of all the galaxies in the VIPERS spectroscopic survey. The large volume explored by VIPERS will enable a unique investigation of the relationship between the galaxy properties and their environment (density field and cosmic web) at high redshift (0.5 < z < 1.2). In this paper, we present the observations, the data reductions and the build-up of the multi-color catalogs. The CFHTLS-T0007 (gri-{\\chi}^2) images are used as reference to detect and measure the $K_s$-band photometry, while the T0007 u-selected sources are used as priors to perform the GALEX photometry based on a dedicated software (EMphot). Our final sample reaches $NUV_{AB}$~25 (at 5{\\sigma})...

  4. Revisiting saw-scaled viper (Echis carinatus) bites in the Jaffna Peninsula of Sri Lanka: distribution, epidemiology and clinical manifestations.

    Science.gov (United States)

    Kularatne, S A M; Sivansuthan, S; Medagedara, S C; Maduwage, K; de Silva, A

    2011-10-01

    In Sri Lanka, the saw-scaled viper (Echis carinatus) is distributed in the arid, dry and sandy coastal plains and in a prospective study we describe its bites in the Jaffna peninsula. Of the 304 snake bite admissions to the Jaffna Hospital in 2009, 217 (71.4%) were bitten by either venomous species or envenomed by unidentified snakes. There were 99 (45.6%) reported saw-scaled viper bites, of which 26 were confirmed cases. The length of the offending snakes ranged from 228-310mm and bites mainly occurred in the nearby islands. The median age of the confirmed cases was 34 years (range 1.5-72 years); occupations included housewives (8, 31%), school children (4, 15%) and farmers (2, 8%). In 18 patients (69%), bites occurred in daylight and in 8 (31%) within or near the compounds. The fingers were bitten in 8 (31%) and toes/foot in 11 (42%) cases. There were 2 (8%) dry bites and 19 patients (73%) developed local swelling; one patient developed haemorrhagic blisters. In 24 patients (92%), blood incoagulability manifested between 40 and 1095min after the bite, and three patients (12%) developed spontaneous bleeding. One patient (4%) developed mild acute renal dysfunction. The median time for correction of coagulopathy was 802min (range 180-1669min) with Indian polyvalent antivenom. All recovered. The saw scaled viper is responsible for most venomous bites in the Jaffna peninsula. PMID:21868049

  5. Sexual dimorphism in development and venom production of the insular threatened pit viper Bothrops insularism (Serpentes: Viperidae) of Queimada Grande Island, Brazil

    OpenAIRE

    S.R. Travaglia-Cardoso; A. Zelanis; M. F. D. Furtado

    2010-01-01

    Bothrops insularis is a threatened snake endemic to Queimada Grande Island, southern coast of São Paulo, Brazil, and the occurrence of sexual abnormalities in females (females with functional ovaries and rudimentary hemipenis) has been reported in this population. To date there are few data regarding developmental features of this particular species. The aim of this study was to follow some developmental features in specimens maintained in captivity for seven years in the Herpetology Labora...

  6. Sexual dimorphism in development and venom production of the insular threatened pit viper Bothrops insularism (Serpentes: Viperidae of Queimada Grande Island, Brazil

    Directory of Open Access Journals (Sweden)

    S.R. Travaglia-Cardoso

    2010-09-01

    Full Text Available Bothrops insularis is a threatened snake endemic to Queimada Grande Island, southern coast of São Paulo, Brazil, and the occurrence of sexual abnormalities in females (females with functional ovaries and rudimentary hemipenis has been reported in this population. To date there are few data regarding developmental features of this particular species. The aim of this study was to follow some developmental features in specimens maintained in captivity for seven years in the Herpetology Laboratory at Instituto Butantan, São Paulo, Brazil. We verified a pronounced sexual dimorphism in development and venom production in the specimens analyzed. In this regard, females showed greater length, mass and amount of venom in comparison to males. Our results suggest a possible niche partitioning between the sexes that reduces (or minimizes intraspecific disharmonic interactions (eg. competition on their small living area (Queimada Grande Island. Taken together, our data suggest that males and females probably are divergent in their diets, with females feeding preferentially on endothermic prey (such as migratory birds, while males maintain the juvenile diet (with the major items being ectothermic prey.

  7. Snake venomics of the Lesser Antillean pit vipers Bothrops caribbaeus and Bothrops lanceolatus: correlation with toxicological activities and immunoreactivity of a heterologous antivenom.

    Science.gov (United States)

    Gutiérrez, José María; Sanz, Libia; Escolano, José; Fernández, Julián; Lomonte, Bruno; Angulo, Yamileth; Rucavado, Alexandra; Warrell, David A; Calvete, Juan J

    2008-10-01

    The venom proteomes of the snakes Bothrops caribbaeus and Bothrops lanceolatus, endemic to the Lesser Antillean islands of Saint Lucia and Martinique, respectively, were characterized by reverse-phase HPLC fractionation, followed by analysis of each chromatographic fraction by SDS-PAGE, N-terminal sequencing, MALDI-TOF mass fingerprinting, and collision-induced dissociation tandem mass spectrometry of tryptic peptides. The venoms contain proteins belonging to seven ( B. caribbaeus) and five ( B. lanceolatus) types of toxins. B. caribbaeus and B. lanceolatus venoms contain phospholipases A 2, serine proteinases, l-amino acid oxidases and zinc-dependent metalloproteinases, whereas a long disintegrin, DC-fragments and a CRISP molecule were present only in the venom of B. caribbaeus, and a C-type lectin-like molecule was characterized in the venom of B. lanceolatus. Compositional differences between venoms among closely related species from different geographic regions may be due to evolutionary environmental pressure acting on isolated populations. The venoms of these two species differed in the composition and the relative abundance of their component toxins, but they exhibited similar toxicological and enzymatic profiles in mice, characterized by lethal, hemorrhagic, edema-forming, phospholipase A 2 and proteolytic activities. The venoms of B. caribbaeus and B. lanceolatus are devoid of coagulant and defibrinogenating effects and induce only mild local myotoxicity in mice. The characteristic thrombotic effect described in human envenomings by these species was not reproduced in the mouse model. The toxicological profile observed is consistent with the abundance of metalloproteinases, PLA 2s and serine proteinases in the venoms. A polyvalent (Crotalinae) antivenom produced in Costa Rica was able to immunodeplete approximately 80% of the proteins from both B. caribbaeus and B. lanceolatus venoms, and was effective in neutralizing the lethal, hemorrhagic, phospholipase A 2 and proteolytic activities of these venoms. PMID:18785768

  8. Systematics and Species Validity of the Dabieshan Pit Viper Protobothrops dabieshanensis Huang et al. 2012:Evidence from a Mitochondrial Gene Sequence Analysis

    Institute of Scientific and Technical Information of China (English)

    Baowei ZHANG; Xin HUANG; Tao PAN; Liang ZHANG; Wenliang ZHOU; Tao SONG; Demin HAN

    2013-01-01

    Aimed to evaluate the phylogenetic position of the recently described Protobothrops dabieshanensis Huang et al. (2012), phylogenic relationships of 12 species within Protobothrops based on four mtDNA gene fragments (12S RNA, 16S RNA, ND4 and Cyt b) were reconstructed in our study. The result indicates a clade composed of P. dabiesha-nensis, P. jerdonii and P. xiangchengsis with strong support. The genetic distance among P. dabieshanensis, P. jerdonii and P. xiangchengsis was much lower than other congeners. Based on the data from the phylogenetic analysis and pre-viously described morphological differences, we conclude that P. dabieshanensis is a valid species with close afifnities to P. jerdonii and P. xiangchengsis.

  9. Project Development Specification for Valve Pit Manifold

    Energy Technology Data Exchange (ETDEWEB)

    MCGREW, D.L.

    2000-09-28

    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.

  10. Project Development Specification for Valve Pit Manifold

    International Nuclear Information System (INIS)

    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. 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...

  12. Zgornje Radvanje, Cluster 10 – a Late Neolithic pit with a structure and smaller pits

    Directory of Open Access Journals (Sweden)

    Bine Kramberger

    2011-12-01

    Full Text Available Many hollows defined as pit houses are known from the Neo-Eneolithic period. Similar pits were also detected at the Neo-Eneolithic settlement of Zgornje Radvanje. The cluster of pits presented in this paper shows a stratigraphic sequence. One of the phases yielded a structure. Pottery forms, production and decoration are presented for each individual phase. A comparison of pottery forms and decoration with other sites indicates that the earliest pottery assemblages originate from the late Neolithic period.

  13. Pit 9 project: A private sector initiative

    International Nuclear Information System (INIS)

    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)

  14. Pitting corrosion of copper. Further model studies

    International Nuclear Information System (INIS)

    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

  15. Potassium-dependent assembly of coated pits: new coated pits form as planar clathrin lattices

    OpenAIRE

    1986-01-01

    Previous studies have shown that when human fibroblasts are depleted of intracellular K+, coated pits disappear from the cell surface and the receptor-mediated endocytosis of low density lipoprotein (LDL) is inhibited. We have now used the K+ depletion protocol to study several aspects of coated pit function. First, since coated pits rapidly form when K+-depleted fibroblasts are incubated in the presence of 10 mM KCl, we studied the sequence of assembly of coated pits as visualized in carbon-...

  16. W-12 valve pit decontamination demonstration

    International Nuclear Information System (INIS)

    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

  17. The VIMOS Public Extragalactic Redshift Survey (VIPERS). Environmental effects shaping the galaxy stellar mass function

    Science.gov (United States)

    Davidzon, I.; Cucciati, O.; Bolzonella, M.; De Lucia, G.; Zamorani, G.; Arnouts, S.; Moutard, T.; Ilbert, O.; Garilli, B.; Scodeggio, M.; Guzzo, L.; Abbas, U.; Adami, C.; Bel, J.; Bottini, D.; Branchini, E.; Cappi, A.; Coupon, J.; de la Torre, S.; Di Porto, C.; Fritz, A.; Franzetti, P.; Fumana, M.; Granett, B. R.; Guennou, L.; Iovino, A.; Krywult, J.; Le Brun, V.; Le Fèvre, O.; Maccagni, D.; Małek, K.; Marulli, F.; McCracken, H. J.; Mellier, Y.; Moscardini, L.; Polletta, M.; Pollo, A.; Tasca, L. A. M.; Tojeiro, R.; Vergani, D.; Zanichelli, A.

    2016-02-01

    We exploit the first public data release of VIPERS to investigate environmental effects in the evolution of galaxies between z ~ 0.5 and 0.9. The large number of spectroscopic redshifts (more than 50 000) over an area of about 10 deg2 provides a galaxy sample with high statistical power. The accurate redshift measurements (σz = 0.00047(1 + zspec)) allow us to robustly isolate galaxies living in the lowest and highest density environments (δ 4, respectively) as defined in terms of spatial 3D density contrast δ. We estimate the stellar mass function of galaxies residing in these two environments and constrain the high-mass end (ℳ ≳ 1011 ℳ⊙) with unprecedented precision. We find that the galaxy stellar mass function in the densest regions has a different shape than was measured at low densities, with an enhancement of massive galaxies and a hint of a flatter (less negative) slope at zrelate estimates from different redshift bins. We observe an evolution of the stellar mass function of VIPERS galaxies in high densities, while the low-density one is nearly constant. We compare these results to semi-analytical models and find consistent environmental signatures in the simulated stellar mass functions. We discuss how the halo mass function and fraction of central/satellite galaxies depend on the environments considered, making intrinsic and environmental properties of galaxies physically coupled, hence difficult to disentangle. The evolution of our low-density regions is described well by the formalism introduced by Peng et al. (2010, ApJ, 721, 193), and is consistent with the idea that galaxies become progressively passive because of internal physical processes. The same formalism could also describe the evolution of the mass function in the high density regions, but only if a significant contribution from dry mergers is considered. Based on observations collected at the European Southern Observatory, Cerro Paranal, Chile, using the Very Large Telescope under

  18. 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.

  19. 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).

  20. Haemostatic dysfunction and acute renal failure following envenoming by Merrem's hump-nosed viper (Hypnale hypnale) in Sri Lanka: first authenticated case.

    Science.gov (United States)

    de Silva, A; Wijekoon, A S; Jayasena, L; Abeysekera, C K; Bao, C X; Hutton, R A; Warrell, D A

    1994-01-01

    A five years old boy was bitten by a Merrem's hump-nosed viper (Hypnale hypnale) in Central Province, Sri Lanka. He developed local swelling, incoagulable blood, thrombocytopenia, bleeding into the gastrointestinal tract, and acute renal failure. Treatment with Serum Institute of Indian polyspecific antivenom (specific for venoms of cobra, common krait, Russell's viper and saw-scaled viper) had no effect on the coagulopathy, which persisted for more than a week. The boy recovered after 27 d in hospital, during which he was treated with peritoneal dialysis for renal failure. Laboratory studies demonstrated that the venom of H. hypnale was procoagulant, fibrinolytic and aggregated platelets. This first authenticated case of life-threatening acute renal failure and haemostatic disturbances caused by H. hypnale, a species responsible for 27% of snake bites in Sri Lanka, demonstrates the need for a new antivenom with specific activity against the venom of this species. PMID:8036678

  1. A nesting of vipers: Phylogeny and historical biogeography of the Viperidae (Squamata: Serpentes).

    Science.gov (United States)

    Wüster, Wolfgang; Peppin, Lindsay; Pook, Catharine E; Walker, Daniel E

    2008-11-01

    Despite their medical interest, the phylogeny of the snake family Viperidae remains inadequately understood. Previous studies have generally focused either on the pitvipers (Crotalinae) or on the Old World vipers (Viperinae), but there has been no comprehensive molecular study of the Viperidae as a whole, leaving the affinities of key taxa unresolved. Here, we infer the phylogenetic relationships among the extant genera of the Viperidae from the sequences of four mitochondrial genes (cytochrome b, NADH subunit 4, 16S and 12S rRNA). The results confirm Azemiops as the sister group of the Crotalinae, whereas Causus is nested within the Viperinae, and thus not a basal viperid or viperine. Relationships among the major clades of Viperinae remain poorly resolved despite increased sequence information compared to previous studies. Bayesian molecular dating in conjunction with dispersal-vicariance analysis suggests an early Tertiary origin in Asia for the crown group Viperidae, and rejects suggestions of a relatively recent, early to mid-Tertiary origin of the Caenophidia. PMID:18804544

  2. Climate change and peripheral populations: predictions for a relict Mediterranean viper

    Directory of Open Access Journals (Sweden)

    José C. Brito

    2011-06-01

    Full Text Available Ecological niche-based models were developed in peripheral populations of Vipera latastei North Africa to: 1 identify environmental factors related to species occurrence; 2 identify present suitable areas; 3 estimate future areas according to forecasted scenarios of climate change; and 4 quantify habitat suitability changes between present and future climatic scenarios. Field observations were combined with environmental factors to derive an ensemble of predictions of species occurrence. The resulting models were projected to the future North African environmental scenarios. Species occurrence was most related to precipitation variation. Present suitable habitats were fragmented and ranged from coastal to mountain habitats, and the overall fragmented range suggests a relict distribution from wider past ranges. Future projections suggest a progressive decrease in suitable areas. The relationship with precipitation supports the current unsuitability of most North Africa for the species and predicts future increased extinction risk. Monitoring of population trends and full protection of mountain forests are key-targets for long-term conservation of African populations of this viper. Predicted trends may give indications about other peripheral populations of Palearctic vertebrates in North Africa which should be assessed in detail.

  3. Snakebite Envenoming by Sochurek's Saw-scaled Viper Echis Carinatus Sochureki.

    Science.gov (United States)

    Valenta, Jiří; Stach, Zdeněk; Michálek, Pavel

    2016-01-01

    A snake breeder, 47-years-old man, was bitten by the saw-scaled viper (Echis carinatus sochureki). After admission to Toxinology Centre, within 1.5 h, laboratory evaluation showed clotting times prolonged to non-measurable values, afibrinogenaemia, significantly elevated D-dimers, haemolysis and myoglobin elevation. Currently unavailable antivenom was urgently imported and administered within 10 hours. In 24 hours, oligoanuric acute kidney injury (AKI) and mild acute respiratory distress syndrome (ARDS) developed. Despite administration of 10 vials of urgently imported Polyvalent Snake Antivenom Saudi Arabia, the venom-induced consumption coagulopathy (VICC) and AKI persisted. Another ten vials of antivenom were imported from abroad. VICC slowly subsided during the antivenom treatment and disappeared after administration of total 20 vials during 5 day period. No signs of haemorrhage were present during treatment. After resolving VICC, patient was transferred to Department of Nephrology for persisting AKI and requirement for haemodialysis. AKI completely resolved after 20 days. Despite rather timed administration of appropriate antivenom, VICC and AKI developed and the quantity of 20 vials was needed to cease acute symptoms of systemic envenoming. The course illustrates low immunogenicity of the venom haemocoagulation components and thus higher requirements of the antivenom in similar cases. PMID:26995204

  4. The VIMOS Public Extragalactic Redshift Survey (VIPERS). Environmental effects shaping the galaxy stellar mass function

    CERN Document Server

    Davidzon, I; Bolzonella, M; De Lucia, G; Zamorani, G; Arnouts, S; Moutard, T; Ilbert, O; Garilli, B; Scodeggio, M; Guzzo, L; Abbas, U; Adami, C; Bel, J; Bottini, D; Branchini, E; Cappi, A; Coupon, J; de la Torre, S; Di Porto, C; Fritz, A; Franzetti, P; Fumana, M; Granett, B R; Guennou, L; Iovino, A; Krywult, J; Brun, V Le; Fevre, O Le; Maccagni, D; Małek, K; Marulli, F; McCracken, H J; Mellier, Y; Moscardini, L; Polletta, M; Pollo, A; Tasca, L A M; Tojeiro, R; Vergani, D; Zanichelli, A

    2016-01-01

    We exploit the first public data release of VIPERS to investigate environmental effects in galaxy evolution between $z\\sim0.5$ and $0.9$. The large number of spectroscopic redshifts over an area of about $10\\,\\mathrm{deg}^2$ provides a galaxy sample with high statistical power. The accurate redshift measurements, with $\\sigma_z = 0.00047(1+z_\\mathrm{spec})$, allow us to robustly isolate galaxies living in the lowest- and highest-density environments, as defined in terms of spatial 3D density contrast. We estimate the stellar mass function (SMF) of galaxies residing in these two environments, and constrain its high-mass end with unprecedented precision. We find that the galaxy SMF in the densest regions has a different shape than that measured at low densities, with an enhancement of massive galaxies and a hint of a flatter (less negative) slope at $z<0.8$. We normalise each SMF to the comoving volume occupied by the corresponding environment, and relate estimates from different redshift bins. We observe an...

  5. 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.

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

    International Nuclear Information System (INIS)

    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.

  7. The VIPERS Multi-Lambda Survey. I. UV and near-IR observations, multi-colour catalogues, and photometric redshifts

    Science.gov (United States)

    Moutard, T.; Arnouts, S.; Ilbert, O.; Coupon, J.; Hudelot, P.; Vibert, D.; Comte, V.; Conseil, S.; Davidzon, I.; Guzzo, L.; Llebaria, A.; Martin, C.; McCracken, H. J.; Milliard, B.; Morrison, G.; Schiminovich, D.; Treyer, M.; Van Werbaeke, L.

    2016-05-01

    We present observations collected in the CFHTLS-VIPERS region in the ultraviolet with the GALEX satellite (far- and near-ultraviolet channels) and in the near-infrared with the CFHT/WIRCam camera (Ks band) over an area of 22 and 27 deg2, respectively. The depth of the photometry was optimised to measure the physical properties (e.g., star formation rate, stellar masses) of all the galaxies in the VIPERS spectroscopic survey. The large volume explored by VIPERS will enable a unique investigation of the relationship between the galaxy properties and their environment (density field and cosmic web) at high redshift (0.5 ≤ z ≤ 1.2). In this paper, we present the observations, the data reductions, and the build-up of the multi-colour catalogues. The CFHTLS-T0007 (gri-χ2) images are used as reference to detect and measure the Ks-band photometry, while the T0007 u∗-selected sources are used as priors to perform the GALEX photometry based on a dedicated software (EMphot). Our final sample reaches NUVAB ~ 25 (at 5σ) and KAB ~ 22 (at 3σ). The large spectroscopic sample (~51 000 spectroscopic redshifts) allows us to highlight the robustness of our star/galaxy separation and the reliability of our photometric redshifts with a typical accuracy of σz ≤ 0.04 and a fraction of catastrophic failures η ≤ 2% down to i ~ 23. We present various tests on the Ks-band completeness and photometric redshift accuracy by comparing our results with existing overlapping deep photometric catalogues. Finally, we discuss the BzK sample of passive and active galaxies at high redshift and the evolution of galaxy morphology in the (NUV-r) vs. (r-Ks) diagram at low redshift (z ≤ 0.25) based on the high image quality of the CFHTLS. The catalogue is available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/590/A102The images, catalogues, and photometric redshifts for 1.5 million sources (down to NUV

  8. Saw-Scaled Viper Bites in Sri Lanka: Is It a Different Subspecies? Clinical Evidence from an Authenticated Case Series

    OpenAIRE

    Gnanathasan, Ariaranee; Rodrigo, Chaturaka; Peranantharajah, Thambipillai; Coonghe, Anthonia

    2012-01-01

    The saw-scaled viper (SSV) (Echis carinatus) is considered to be a highly venomous snake in Sri Lanka despite any published clinical justification. Being a rarity, the clinical profile of SSV bites is not well established in Sri Lanka. We report a series of 48 (n-48) SSV bites from the Northern Province of Sri Lanka. The majority (65%) of victims had evidence of local envenoming at the site of the bite; however, 29% showed spontaneous bleeding and 71% had coagulopathy. There were no deaths in...

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

    International Nuclear Information System (INIS)

    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. Global methane emissions from pit latrines.

    Science.gov (United States)

    Reid, Matthew C; Guan, Kaiyu; Wagner, Fabian; Mauzerall, Denise L

    2014-01-01

    Pit latrines are an important form of decentralized wastewater management, providing hygienic and low-cost sanitation for approximately one-quarter of the global population. Latrines are also major sources of the greenhouse gas methane (CH4) from the anaerobic decomposition of organic matter in pits. In this study, we develop a spatially explicit approach to account for local hydrological control over the anaerobic condition of latrines and use this analysis to derive a set of country-specific emissions factors and to estimate global pit latrine CH4 emissions. Between 2000 and 2015 we project global emissions to fall from 5.2 to 3.8 Tg y(-1), or from ∼ 2% to ∼ 1% of global anthropogenic CH4 emissions, due largely to urbanization in China. Two and a half billion people still lack improved sanitation services, however, and progress toward universal access to improved sanitation will likely drive future growth in pit latrine emissions. We discuss modeling results in the context of sustainable water, sanitation, and hygiene development and consider appropriate technologies to ensure hygienic sanitation while limiting CH4 emissions. We show that low-CH4 on-site alternatives like composting toilets may be price competitive with other CH4 mitigation measures in organic waste sectors, with marginal abatement costs ranging from 57 to 944 $/ton carbon dioxide equivalents (CO2e) in Africa and 46 to 97 $/ton CO2e in Asia. PMID:24999745

  11. 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…

  12. The surviving engines of Glyn Pits

    Energy Technology Data Exchange (ETDEWEB)

    Gwyn Tilley

    2005-11-15

    The book describes two of the only surviving examples of Victorian engines. These engines await restoration at Glyn Pits, Pontypool in South Wales, and in this volume there is detailed information about the engines and their historical context. An interesting documentation about industrial archaeology connected with mining and metal working.

  13. 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)...

  14. Cavitation characteristics of pit structure in ultrasonic field

    Institute of Scientific and Technical Information of China (English)

    BAI LiXin; XU WeiLin; ZHANG FaXing; LI NaiWen; ZHANG YiChi; HUANG DeFa

    2009-01-01

    Bubble collecting, bubble holding and micro-bubble ejecting characteristics of pit structure and the influence of cavitation bubble on the development of erosion pit are investigated by means of highspeed photography experiments. Pits tend to collect and hold wandering cavitation bubbles. The air holding phenomenon of pits can be a destination of the incubation period in the process of cavitation erosion. The holding bubble tends to eject micro-bubbles from the top of holding cavitation bubble,making the pit a source of nuclei. With bubbles being held in pits, the diameters of pits increase rapidly.But in the given experiment condition, there is a specific stable value beyond which the diameter of pits will not increase. This characteristic will be helpful in understanding and predicting the cavitation erosion process.

  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. Some questions on small uranium open-pit mines

    International Nuclear Information System (INIS)

    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

  17. 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...

  18. Mosh pits and Circle pits: Collective motion at heavy metal concerts

    Science.gov (United States)

    Bierbaum, Matthew; Silverberg, Jesse L.; Sethna, James P.; Cohen, Itai

    2013-03-01

    Heavy metal concerts present an extreme environment in which large crowds (~102 -105) of humans experience very loud music (~ 130 dB) in sync with bright, flashing lights, often while intoxicated. In this setting, we find two types of collective motion: mosh pits, in which participants collide with each other randomly in a manner resembling an ideal gas, and circle pits, in which participants run collectively in a circle forming a vortex of people. We model these two collective behaviors using a flocking model and find qualitative and quantitative agreement with the behaviors found in videos of metal concerts. Futhermore, we find a phase diagram showing the transition from a mosh pit to a circle pit as well as a predicted third phase, lane formation.

  19. 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

  20. Cyclic transmission of Sarcocystis gerbilliechis n. sp. by the Arabian saw-scaled viper, Echis coloratus, to rodents of the subfamily gerbillinae.

    Science.gov (United States)

    Jäkel, T

    1995-08-01

    Infection experiments with rodents and snakes were performed to elucidate the life cycle of a Sarcocystis isolate found in an Arabian saw-scaled viper, Echis coloratus. Oocytes in feces of the naturally infected and of 2 experimentally infected Arabian saw-scaled vipers were already sporulated and contained 2 sporocysts each, measuring 12.7 (12.3-13.3) microns x 11.0 (10.7-11.4) microns. After oral inoculation of various rodent species with these sporocysts, sarcocysts developed in the esophagus and skeletal muscles of gerbils and related genera. Mature sarcocysts were filiform in shape and reached a maximum length of 11.7 mm after 5 mo postinoculation (PI), whereas the width did not exceed 190 microns. The primary cyst wall formed small, knoblike protrusions, which were up to 180 nm long and 120 nm wide. Mature schizonts were present in the liver and other organs of gerbils between 11 and 14 days PI. After inoculation of vipers of 3 different genera with mature sarcocysts from gerbils, oocysts developed in the intestine of Arabian saw-scaled vipers. A comparison of these data with those from previously described Sarcocystis species with snake-rodent life cycles suggests that Sarcocystis gerbilliechis is a new species. PMID:7623207

  1. One strategy for arthroscopic suture fixation of tibial intercondylar eminence fractures using the Meniscal Viper Repair System

    Directory of Open Access Journals (Sweden)

    Ochiai Satoshi

    2011-08-01

    Full Text Available Abstract Background Principles for the treatment of tibial intercondylar eminence fracture are early reduction and stable fixation. Numerous ways to treatment of this fracture have been invented. We designed a simple, low-invasive, and arthroscopic surgical strategy for tibial intercondylar eminence fracture utilizing the Meniscal Viper Repair System used for arthroscopic meniscal suture. Methods We studied 5 patients, who underwent arthroscopic suture fixation that we modified. The present technique utilized the Meniscal Viper Repair System for arthroscopic suture of the meniscus. With one handling, a high-strength ultra-high molecular weight polyethylene(UHMWPE suture can be passed through the anterior cruciate ligament (ACL and the loops for suture retrieval placed at both sides of ACL. Surgical results were evaluated by the presence or absence of bone union on plain radiographs, postoperative range of motion of the knee joint, the side-to-side differences measured by Telos SE, and Lysholm scores. Results The reduced position achieved after surgery was maintained and good function was obtained in all cases. The mean distance of tibia anterior displacement and assessment by Lysholm score showed good surgical results. Conclusion This method simplified the conventional arthroscopic suture fixation and increased its precision, and was applicable to Type II fractures that could be reduced, as well as surgically indicated Types III and IV. The present series suggested that our surgical approach was a useful surgical intervention for tibial intercondylar eminence fracture.

  2. Quantitative Proteomic Analysis of Venoms from Russian Vipers of Pelias Group: Phospholipases A2 are the Main Venom Components

    Science.gov (United States)

    Kovalchuk, Sergey I.; Ziganshin, Rustam H.; Starkov, Vladislav G.; Tsetlin, Victor I.; Utkin, Yuri N.

    2016-01-01

    Venoms of most Russian viper species are poorly characterized. Here, by quantitative chromato-mass-spectrometry, we analyzed protein and peptide compositions of venoms from four Vipera species (V. kaznakovi, V. renardi, V. orlovi and V. nikolskii) inhabiting different regions of Russia. In all these species, the main components were phospholipases A2, their content ranging from 24% in V. orlovi to 65% in V. nikolskii. Altogether, enzyme content in venom of V. nikolskii reached ~85%. Among the non-enzymatic proteins, the most abundant were disintegrins (14%) in the V. renardi venom, C-type lectin like (12.5%) in V. kaznakovi, cysteine-rich venom proteins (12%) in V. orlovi and venom endothelial growth factors (8%) in V. nikolskii. In total, 210 proteins and 512 endogenous peptides were identified in the four viper venoms. They represented 14 snake venom protein families, most of which were found in the venoms of Vipera snakes previously. However, phospholipase B and nucleotide degrading enzymes were reported here for the first time. Compositions of V. kaznakovi and V. orlovi venoms were described for the first time and showed the greatest similarity among the four venoms studied, which probably reflected close relationship between these species within the “kaznakovi” complex. PMID:27077884

  3. 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. PMID:27354013

  4. Combined snake venomics and venom gland transcriptomic analysis of the ocellated carpet viper, Echis ocellatus.

    Science.gov (United States)

    Wagstaff, Simon C; Sanz, Libia; Juárez, Paula; Harrison, Robert A; Calvete, Juan J

    2009-01-30

    Snakebite in Africa causes thousands of deaths annually and considerable permanent physical disability. The saw-scaled viper, Echis ocellatus, represents the single most medically important snake species in West Africa. To provide a detailed compositional analysis of the venom of E. ocellatus for designing novel toxin-specific immunotherapy and to delineate sequence structure-function relationships of individual toxins, we characterised the venom proteome and the venom gland transcriptome. Whole E. ocellatus venom was fractionated by reverse-phase HPLC, followed by analysis of each chromatographic fraction using a combination of SDS-PAGE, N-terminal sequencing, MALDI-TOF mass fingerprinting, and CID-MS/MS of tryptic peptides. This analysis identified around 35 distinct proteins of molecular masses in the range of 5.5-110 kDa belonging to 8 different toxin families (disintegrin, DC-fragment, phospholipase A(2), cysteine-rich secretory protein, serine proteinase, C-type lectin, l-amino acid oxidase, and Zn(2+)-dependent metalloprotease). Comparison of the toxin composition of E. ocellatus venom determined using a proteomic approach, with the predicted proteome derived from assembly of 1000 EST sequences from a E. ocellatus venom gland cDNA library, shows some differences. Most notably, peptides derived from 26% of the venom proteins could not be ascribed an exact match in the transcriptome. Similarly, 64 (67%) out of the 95 putative toxin clusters reported in the transcriptome did not match to peptides detected in the venom proteome. These data suggest that the final composition of venom is influenced by transcriptional and post-translational mechanisms that may be more complex than previously appreciated. This, in turn, emphasises the value of combining proteomic and transcriptomic approaches to acquire a more complete understanding of the precise composition of snake venom, than would be gleaned from using one analysis alone. From a clinical perspective, the large

  5. Probabilistic analysis and interpretation of steam generator tube pitting data

    International Nuclear Information System (INIS)

    'Full text:' Pitting corrosion is a serious form of degradation in steam generator tubing of some CANDU reactors. The occurrence and growth of pits over time are essential inputs to a life-cycle management model. Periodic inspections are carried out to detect and measure corrosion pits in steam generator tubing. However, probabilistic analysis of pit data is not a straightforward task. The reasons are the random measurement error associated with pit sizing, detection uncertainty, and censoring of pit sizes which complicate the estimation of growth rates. Tracking of pits over time to estimate the growth rate is limited by the ability to determine the exact location and elevation of pits between consecutive outages. This paper presents a comprehensive statistical analysis of the pitting data that accounts for limitations of inspection data. The pitting process is modeled as a random process and calibrated with the available data. The model is applied to estimate the distribution of the number extreme pits and probability of tube leakage per SG per EFPY. The application of this model is illustrated for the life-cycle management of steam generators. (author)

  6. Chain of Pits on Pavonis Mons

    Science.gov (United States)

    1999-01-01

    Pavonis Mons is the middle of the three large Tharsis Montes volcanoes in the martian western hemisphere. Located on the equator at about 113oW longitude, Pavonis Mons stands as much as 7 kilometers (4 miles) above the surrounding plain. The Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) recently spied the above chain of elliptical pits on the lower east flank of Pavonis Mons. The picture covers an area 3 kilometers (1.9 miles) wide by 3.4 kilometers (2.1 miles) in length. The pits are aligned down the center of a 485 meters-(530 yards)-wide, shallow trough. The straight trough and the pits were both formed by collapse associated with faulting. The scarp on each side of the trough is a fault line--troughs of this type are known to geologists as graben. Such features are typically formed when the ground is being moved apart by tectonic forces, or when the ground is uplifted by molten rock injected into the near sub-surface from deeper underground. Both processes may be contributing to the features seen on Pavonis Mons. The pits follow the trend of these faults, and indicate the locus of collapse. Illumination is from the upper left in this image. Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

  7. 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.

  8. Constituent Particle Clustering and Pitting Corrosion

    Science.gov (United States)

    Harlow, D. Gary

    2012-08-01

    Corrosion is a primary degradation mechanism that affects the durability and integrity of structures made of aluminum alloys, and it is a concern for commercial transport and military aircraft. In aluminum alloys, corrosion results from local galvanic coupling between constituent particles and the metal matrix. Due to variability in particle sizes, spatial location, and chemical composition, to name a few critical variables, corrosion is a complex stochastic process. Severe pitting is caused by particle clusters that are located near the material surface, which, in turn, serve as nucleation sites for subsequent corrosion fatigue crack growth. These evolution processes are highly dependent on the spatial statistics of particles. The localized corrosion growth rate is primarily dependent on the galvanic process perpetuated by particle-to-particle interactions and electrochemical potentials. Frequently, severe pits are millimeters in length, and these pits have a dominant impact on the structural prognosis. To accommodate large sizes, a model for three-dimensional (3-D) constituent particle microstructure is proposed. To describe the constituent particle microstructure in three dimensions, the model employs a fusion of classic stereological techniques, spatial point pattern analyses, and qualitative observations. The methodology can be carried out using standard optical microscopy and image analysis techniques.

  9. 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

  10. 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.

  11. Saw-scaled viper bites in Sri Lanka: is it a different subspecies? Clinical evidence from an authenticated case series.

    Science.gov (United States)

    Gnanathasan, Ariaranee; Rodrigo, Chaturaka; Peranantharajah, Thambipillai; Coonghe, Anthonia

    2012-02-01

    The saw-scaled viper (SSV) (Echis carinatus) is considered to be a highly venomous snake in Sri Lanka despite any published clinical justification. Being a rarity, the clinical profile of SSV bites is not well established in Sri Lanka. We report a series of 48 (n-48) SSV bites from the Northern Province of Sri Lanka. The majority (65%) of victims had evidence of local envenoming at the site of the bite; however, 29% showed spontaneous bleeding and 71% had coagulopathy. There were no deaths in the series. The envenoming was mild in contrast to the mortality and significant morbidity associated with SSV bites in West Africa and some parts of India. These observations need to be further explored with laboratory studies to identify the venom components, study of morphological characteristics, and genetic profiling of the Sri Lankan SSV to see if it is different from the subspecies found elsewhere. PMID:22302858

  12. Data on the reproduction of a Caucasian Viper, Vipera kaznakovi Nikolsky, 1909 (Serpentes: Viperidae from Hopa (Northeastern Anatolia, Turkey

    Directory of Open Access Journals (Sweden)

    Bayram Göçmen

    2013-12-01

    Full Text Available In the current study we report an observation of a Caucasian Viper, Vipera kaznakovi from Hopa (Artvin, Turkey giving birth. During our field studies, we captured a female Vipera kaznakovi on July 21, 2012 from Esenkıyı village, Hopa (Artvin, Turkey, it was brought to the laboratory and kept in a terrarium for a period until May 28, 2013. The female (SVL= 483 mm, total length, TL = 541 mm gave birth to eight young (mean SVL= 146 mm, mean TL= 161.4 mm, range= 155 – 172 mm; mean weight, W= 3.11 g, range= 2.6 – 3.4 g on August 11, 2012. In six and a half months, the juvenile snakes had reached 163 mm SVL, 187 mm TL and 5.1g W and increased their size by approximately 15%.

  13. The VIMOS Public Extragalactic Redshift Survey (VIPERS). Ωm0 from the galaxy clustering ratio measured at z ~ 1

    Science.gov (United States)

    Bel, J.; Marinoni, C.; Granett, B. R.; Guzzo, L.; Peacock, J. A.; Branchini, E.; Cucciati, O.; de la Torre, S.; Iovino, A.; Percival, W. J.; Steigerwald, H.; Abbas, U.; Adami, C.; Arnouts, S.; Bolzonella, M.; Bottini, D.; Cappi, A.; Coupon, J.; Davidzon, I.; De Lucia, G.; Fritz, A.; Franzetti, P.; Fumana, M.; Garilli, B.; Ilbert, O.; Krywult, J.; Le Brun, V.; Le Fèvre, O.; Maccagni, D.; Małek, K.; Marulli, F.; McCracken, H. J.; Paioro, L.; Polletta, M.; Pollo, A.; Schlagenhaufer, H.; Scodeggio, M.; Tasca, L. A. M.; Tojeiro, R.; Vergani, D.; Zanichelli, A.; Burden, A.; Di Porto, C.; Marchetti, A.; Mellier, Y.; Moscardini, L.; Nichol, R. C.; Phleps, S.; Wolk, M.; Zamorani, G.

    2014-03-01

    We use a sample of about 22 000 galaxies at 0.65 measurement of the galaxy clustering ratio ηg,R. This statistic has favourable properties, which is defined as the ratio of two quantities characterizing the smoothed density field in spheres of a given radius R: the value of its correlation function on a multiple of this scale, ξ(nR), and its variance σ2(R). For sufficiently large values of R, this is a universal number, which captures 2-point clustering information independently of the linear bias and linear redshift-space distortions of the specific galaxy tracers. In this paper, we discuss how to extend the application of ηg,R to quasi-linear scales and how to control and remove observational selection effects, which are typical of redshift surveys as VIPERS, in detail. We verify the accuracy and efficiency of these procedures using mock catalogues that match the survey selection process. These results show the robustness of ηg,R to non-linearities and observational effects, which is related to its very definition as a ratio of quantities that are similarly affected. At an effective redshift z = 0.93, we measured the value ηg,R(15) = 0.141 ± 0.013 at R = 5h-1 Mpc. Within a flat ΛCDM cosmology and by including the best available priors on H0, ns and baryon density, we obtain a matter density parameter at the current epoch Ωm,0 = 0.270-0.025+0.029. In addition to the great precision achieved on our estimation of Ωm using VIPERS PDR-1, this result is remarkable because it appears to be in good agreement with a recent estimate at z ≃ 0.3, which was obtained by applying the same technique to the SDSS-LRG catalogue. It, therefore, supports the robustness of the present analysis. Moreover, the combination of these two measurements at z ~ 0.3 and z ~ 0.9 provides us with a very precise estimate of Ωm,0 = 0.274 ± 0.017, which highlights the great consistency between our estimation and other cosmological probes, such as baryonic acoustic oscillations, cosmic

  14. 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...

  15. THE RELATIONSHIP BETWEEN PITTING SUSCEPTIBILITY AND INCLUSIONS IN CARBON STEELS IN ARTIFICIAL SEAWATER

    Institute of Scientific and Technical Information of China (English)

    X.D. Kong; X.Q. Chen; W.S. Chang; D.B. Chen; J.X. Zheng

    2001-01-01

    The pittings of five carbon steels have been studied by using anodic polarization test and microscope observation. The results show that pitting susceptibilities are related to the types and shapes of inclusions which are the sites of pitting initiation. The pitting initiating at inclusion needs a potential which is defined as pitting potential and the pitting potential is determined by the type and shape of inclusion. The influence of oxygen content in steel on pitting potential is also discussed.

  16. Bingham Pump Outage Pits: Environmental information document

    International Nuclear Information System (INIS)

    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 137Cs and 90Sr) 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

  17. RNA levels of human retrovirus receptors Pit1 and Pit2 do not correlate with infectibility by three retroviral vector pseudotypes

    DEFF Research Database (Denmark)

    Uckert, Wolfgang; Willimsky, Gerald; Pedersen, Finn Skou; Blankenstein, Thomas; Pedersen, Lene

    1998-01-01

    The gibbon ape leukemia virus (GaLV) and the amphotropic murine leukemia virus (A-MuLV) infect human cells via specific receptors, Pit1 and Pit2, respectively. mRNA levels of these receptors were determined by Northern analysis and for Pit2 in addition by quantitative RT-PCR. Pit1 and Pit2 were e...... Pit1 RNA; (3) factor(s) in addition to the presence of Pit1 and Pit2 are involved in retroviral infection; and (4) MuLV-10A1 pseudotype does not infect human cells more efficiently than do A-MuLV and GaLV pseudotypes....

  18. 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.

  19. Markov chain modelling of pitting corrosion in underground pipelines

    International Nuclear Information System (INIS)

    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.

  20. Pitted terrains on Vesta: Thermophysical analysis

    Science.gov (United States)

    Capria, M.; Tosi, F.; De Sanctis, M.; Turrini, D.; Ammannito, E.; Capaccioni, F.; Fonte, S.; Frigeri, A.; Longobardo, A.; Palomba, E.; Zambon, F.; Schroeder, S.; Denevi, B.; Williams, D.; Scully, J.; Russell, C.; Raymond, C.

    2014-07-01

    Launched in 2007, the Dawn spacecraft, after one year spent orbiting Vesta, is now on its way to Ceres. In the science payload, the Visible and Infrared mapping spectrometer (VIR) is devoted to the study of the mineralogical composition and thermophysical properties of Vesta's surface [1]. Disk-resolved surface temperatures of Vesta have been determined from the infrared spectra measured by VIR [2]. The observed temperatures, together with a thermophysical model, have been used to constrain the thermal properties of a large part of the surface of the asteroid [3]. The average thermal inertia of the surface is quite low, consistent with a widespread presence of a dust layer. While the global thermal inertia is low, the characterization of its surface in terms of regions showing peculiar thermophysical properties gives us the possibility to identify specific areas with different thermal and structural characteristics. These variations can be linked to strong albedo variations that have been observed, or to other physical and structural characteristics of the first few centimeters of the soil. The highest values of thermal inertia have been determined on areas coinciding with locations where pitted terrains have been found [4]. Pitted terrains, first identified on Mars, have been found in association with 4 craters on Vesta: Marcia, Cornelia, Licinia, and Numisia. The Marcia area is characterized by high hydrogen and OH content [5]. By analogy with Mars, the formation of these terrains is thought to be due to the rapid release of volatiles, triggered by heating from an impact event. A question arises on the origin of volatiles: hydrated minerals, or ground, buried ice? In order to discuss the second hypothesis, we have to assume that a comet impact delivers ice that gets buried under a layer of regolith. Successively, another impact on the same area would give origin to the pitted terrain. The buried ice has obviously to survive for the time between the two impacts

  1. Nitrate pollution of groundwater by pit latrines in developing countries

    OpenAIRE

    Templeton, Michael R.; Acile S. Hammoud; Adrian P. Butler; Laura Braun; Julie-Anne Foucher; Johanna Grossmann; Moussa Boukari; Serigne Faye; Jean Patrice Jourda

    2015-01-01

    Pit latrines are one of the most common forms of onsite sanitation facilities in many developing countries. These latrines are suitable as a means of isolating human waste, however, conditions within pits often lead to nitrification of the contained waste. In areas with a near-surface aquifer, the potential for nitrate pollution arising from pit latrines cannot be ignored. In this study, site visits were made to three densely populated, peri-urban areas near three West African cities (Dakar, ...

  2. Pitting behavior of 2024 aluminum alloy in nitrate solutions

    International Nuclear Information System (INIS)

    Pitting of 2024 aluminum alloy was investigated in chloride-containing nitrate solutions. Potentiostatic and potentiokinetic experiments followed by examination of the sample surface were performed in order to relate the pitting behavior of the alloy to its microstructure. The SEM examination showed that copper-rich particles were preferential sites for pitting. These particles started dissolving during the polarization in nitrate solutions due to the agressivity of nitrate ions toward copper. In the presence of chloride ions, these particles were completely dissolved. Nitrate ions on the other hand appeared to have a very strong inhibitory effect toward pitting in the aluminum matrix. (author)

  3. EKA hoonelt rebiti maha kaunistav pits / Urmas Tooming

    Index Scriptorium Estoniae

    Tooming, Urmas, 1954-

    2011-01-01

    Ehituskulude vähendamiseks muudeti Eesti Kunstiakadeemia uue hoone projekti. Maja välisfassaadilt eemaldati kaunistav pits ja loobuti spiraalsest aatriumist. Ehitusplatsile hakatakse rajama metallist sulundseina

  4. Determination of in vivo toxicity and in vitro cytotoxicity of venom from the Cypriot blunt-nosed viper Macrovipera lebetina lebetina and antivenom production

    OpenAIRE

    A Nalbantsoy; NU Karabay-Yavasoglu; F Sayim; I Deliloglu-Gurhan; B Gocmen; ARIKAN, H.; MZ Yildiz

    2012-01-01

    The venomous Levantine viper, Macrovipera lebetina lebetina is endemic to Cyprus. The objective of this study was to investigate in vitro cytotoxicity, in vivo lethality, and antivenom production followed by a re-immunization schedule in mice against Macrovipera lebetina lebetina venom. The LD50 value was estimated as 7.58 mg/kg within 24 hours by different venom doses administrated intraperitoneally in mice. Freund's complete and incomplete adjuvants were used for first and second immunizati...

  5. Introduction to Pits and Weapons Systems (U)

    Energy Technology Data Exchange (ETDEWEB)

    Kautz, D. [Los Alamos National Laboratory

    2012-07-02

    A Nuclear Explosive Package includes the Primary, Secondary, Radiation Case and related components. This is the part of the weapon that produces nuclear yield and it converts mechanical energy into nuclear energy. The pit is composed of materials that allow mechanical energy to be converted to electromagnetic energy. Fabrication processes used are typical of any metal fabrication facility: casting, forming, machining and welding. Some of the materials used in pits include: Plutonium, Uranium, Stainless Steel, Beryllium, Titanium, and Aluminum. Gloveboxes are used for three reasons: (1) Protect workers and public from easily transported, finely divided plutonium oxides - (a) Plutonium is very reactive and produces very fine particulate oxides, (b) While not the 'Most dangerous material in the world' of Manhattan Project lore, plutonium is hazardous to health of workers if not properly controlled; (2) Protect plutonium from reactive materials - (a) Plutonium is extremely reactive at ambient conditions with several components found in air: oxygen, water, hydrogen, (b) As with most reactive metals, reactions with these materials may be violent and difficult to control, (c) As with most fabricated metal products, corrosion may significantly affect the mechanical, chemical, and physical properties of the product; and (3) Provide shielding from radioactive decay products: {alpha}, {gamma}, and {eta} are commonly associated with plutonium decay, as well as highly radioactive materials such as {sup 241}Am and {sup 238}Pu.

  6. Identification of cDNAs encoding viper venom hyaluronidases: cross-generic sequence conservation of full-length and unusually short variant transcripts.

    Science.gov (United States)

    Harrison, Robert A; Ibison, Frances; Wilbraham, Davina; Wagstaff, Simon C

    2007-05-01

    The immobilisation of prey by snakes is most efficiently achieved by the rapid dissemination of venom from its site of injection into the blood stream. Hyaluronidase is a common component of snake venoms and has been termed the "venom spreading factor". In the absence of nucleotide or protein sequence data to confirm the functional identity of this venom component, we interrogated a venom gland EST database for the saw-scaled viper, Echis ocellatus (Nigeria), using the gene ontology (GO) term "carbohydrate metabolism". A single hyalurononglucosaminadase-activity matching sequence (EOC00242) was found and used to design PCR primers to acquire the full-length cDNA sequence. Although very different from the bee venom and mammalian hyaluronidase sequences, the E. ocellatus sequence retained all the catalytic, positional and structural residues that characterise this class of carbohydrate metabolising hydrolases. An extraordinarily high level of sequence identity (>95%) was observed in analogous venom gland cDNA sequences isolated (by PCR) from another saw-scaled viper species, E. pyramidum leakeyi (Kenya), and from the sahara horned viper, Cerastes cerastes cerastes (Egypt) and the puff adder, Bitis arietans (Nigeria). Smaller amplicons, lacking hyaluronidase catalytic residues because of 768 bp or 855 bp central deletions, appear to encode either truncated peptides without hyaluronidase activity, or are non-translated transcripts because they lack consensus translation initiating motifs. PMID:17210232

  7. 241-AY-102 Leak Detection Pit Drain Line Inspection Report

    Energy Technology Data Exchange (ETDEWEB)

    Boomer, Kayle D. [Washington River Protection Solutions, LLC (United States); Engeman, Jason K. [Washington River Protection Solutions, LLC (United States); Gunter, Jason R. [Washington River Protection Solutions, LLC (United States); Joslyn, Cameron C. [Washington River Protection Solutions, LLC (United States); Vazquez, Brandon J. [Washington River Protection Solutions, LLC (United States); Venetz, Theodore J. [Washington River Protection Solutions, LLC (United States); Garfield, John S. [AEM Consulting (United States)

    2014-01-20

    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.

  8. 241-AY-102 Leak Detection Pit Drain Line Inspection Report

    International Nuclear Information System (INIS)

    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

  9. 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 tabl

  10. EXPERIMENTAL AND FIELD STUDY ON MINING-PIT MIGRATION

    Institute of Scientific and Technical Information of China (English)

    S. Ali Akbar Salehi NEYSHABOURI; Ali FARHADZADEH; Ata AMINI

    2002-01-01

    Rivers are one of the most essential sources of sand and gravel supply for civil works. However,undesirable effects of irregular in-stream mining have been reported on natural sources, environment and infrastructures close to rivers. Therefore, it is necessary to find the effects of mining on rivers in more details. This research concentrates on mining-pit migration phenomenon and its effects on the channel bed.This paper reports an experimental study on the migration of rectangular mining pits and variation of longitudinal profile in the channel bed composed of rather uniform sediments. Different values of widths and lengths were used for pit while pit depths and flow variables were kept constant. The results show that the migration speed changes with the length/width ratio of the pit. The migration speed in convection period is higher than that in diffusion period. In addition, by increasing the length or width, filling rate of pit increases, where the effect of width is more important than the effect of the length. Also is reported in this paper a field study on the changes of three pits excavated at different locations of a river. Some similarities between the pit migration in the straight reach of the river and that of the experimental work is realized and presented.

  11. Flare pit reclamation in British Columbia

    International Nuclear Information System (INIS)

    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. Construction of the KUT test pits

    International Nuclear Information System (INIS)

    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 U3O8 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

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

    International Nuclear Information System (INIS)

    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

  14. Liquid waste processing from TRIGA spent fuel storage pits

    International Nuclear Information System (INIS)

    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 m3. 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

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

    OpenAIRE

    Victor Mwango Bowa

    2015-01-01

    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 desig...

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

    International Nuclear Information System (INIS)

    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

  17. 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.

  18. The galaxy-halo connection from a joint lensing, clustering and abundance analysis in the CFHTLenS/VIPERS field

    CERN Document Server

    Coupon, J; van Waerbeke, L; Moutard, T; Ilbert, O; van Uitert, E; Erben, T; Garilli, B; Guzzo, L; Heymans, C; Hildebrandt, H; Hoekstra, H; Kilbinger, M; Kitching, T; Mellier, Y; Miller, L; Scodeggio, M; Bonnett, C; Branchini, E; Davidzon, I; De Lucia, G; Fritz, A; Fu, L; Hudelot, P; Hudson, M J; Kuijken, K; Leauthaud, A; Fèvre, O Le; McCracken, H J; Moscardini, L; Rowe, B T P; Schrabback, T; Semboloni, E; Velander, M

    2015-01-01

    We present new constraints on the relationship between galaxies and their host dark matter halos, measured from the location of the peak of the stellar-to-halo mass ratio (SHMR), up to the most massive galaxy clusters at redshift $z\\sim0.8$ and over a volume of nearly 0.1~Gpc$^3$. We use a unique combination of deep observations in the CFHTLenS/VIPERS field from the near-UV to the near-IR, supplemented by $\\sim60\\,000$ secure spectroscopic redshifts, analysing galaxy clustering, galaxy-galaxy lensing and the stellar mass function. We interpret our measurements within the halo occupation distribution (HOD) framework, separating the contributions from central and satellite galaxies. We find that the SHMR for the central galaxies peaks at $M_{\\rm h, peak} = 1.9^{+0.2}_{-0.1}\\times10^{12} M_{\\odot}$ with an amplitude of $0.025$, which decreases to $\\sim0.001$ for massive halos ($M_{\\rm h} > 10^{14} M_{\\odot}$). Compared to central galaxies only, the total SHMR (including satellites) is boosted by a factor 10 in t...

  19. The VIMOS Public Extragalactic Redshift Survey (VIPERS). The coevolution of galaxy morphology and colour to z~1

    CERN Document Server

    Krywult, J; Pollo, A; Vergani, D; Bolzonella, M; Davidzon, I; Iovino, A; Gargiulo, A; Haines, C P; Scodeggio, M; Guzzo, L; Zamorani, G; Garilli, B; Granett, B R; de la Torre, S; Abbas, U; Adami, C; Bottini, D; Cappi, A; Cucciati, O; Franzetti, P; Fritz, A; Brun, V Le; Fèvre, O Le; Maccagni, D; Małek, K; Marulli, F; Polletta, M; Tojeiro, R; Zanichelli, A; Arnouts, S; Bel, J; Branchini, E; De Lucia, G; Ilbert, O; McCracken, H J; Moscardini, L; Takeuchi, T T

    2016-01-01

    We explore the evolution of the statistical distribution of galaxy morphological properties and colours over the redshift range $0.5VIPERS survey. Galaxy structural parameters are measured by fitting S\\'ersic profiles to $i$-band images and then combined with absolute magnitudes, colours and redshifts, to trace the evolution in a multi-parameter space. We analyse, using a new method, the combination of colours and structural parameters of early- and late-type galaxies in luminosity--redshift space. We found that both the rest-frame colour distributions in the (U-B) vs. (B-V) plane and the S\\'ersic index distributions are well fitted by a sum of two Gaussians, with a remarkable consistency of red-spheroidal and blue-disky galaxy populations, over the explored redshift ($0.5

  20. Pharmacological and biochemical studies on the venom of a clinically important viper snake (Echis carinatus) of Pakistan.

    Science.gov (United States)

    Savanur, Arifa; Ali, Syed Abid; Munir, Iqra; Abbasi, Atiya; Alam, Mehtab; Shaikh, Hilal Ahmed

    2014-03-01

    Echis carinatus (saw-scaled viper) has been the major culprit responsible for serious envenomation casualties throughout the subcontinent. The present study describes the electrophoretic and zymographic characterization of E. carinatus venom and its effect on mammalian smooth muscle. Crude venom showed the presence of disintegrin, PLA2, C-type lectin/lectin-like components, CRISP, Serine protease, l-amino acid oxidase and very high concentrations of SVMPs. E. carinatus venom (1, 10, 30, 50, 100 μg/ml) inhibited the active tension/force of muscle contraction in a time and concentration dependent manner. The observed effects abolished when the venom was heated at 100 °C for 5 min. However, a decrease in bath temperature from 37 °C to 26 °C or an increase in CaCl2 concentration to 5 mM did not prevent the inhibition of contractile activity. The contractile response elicited by exogenous application of 50 mM KCl and 1 μM acetylcholine (ACh) was also significantly inhibited by all venom concentrations. Prior administration of commercially available polyvalent anti-venom partially neutralized and prevented the effect of E. carinatus venom whereas addition of anti-venom at t50 failed to reverse the inhibitory effect. Studies on isolated intestinal muscle indicate involvement of myotoxic and apoptotic components in E. carinatus venom for irreversible damage to muscle tissue. PMID:24462660

  1. Crystal structure of echicetin from Echis carinatus (Indian saw-scaled viper) at 2.4A resolution.

    Science.gov (United States)

    Jasti, Jayasankar; Paramasivam, M; Srinivasan, A; Singh, T P

    2004-01-01

    Echicetin is a heterodimeric protein from the venom of the Indian saw-scaled viper, Echis carinatus. It binds to platelet glycoprotein Ib (GPIb) and thus inhibits platelet aggregation. It has two subunits, alpha and beta, consisting of 131 and 123 amino acid residues, respectively. The two chains are linked with a disulphide bond. The level of amino acid sequence homology between two subunits is 50%. The protein was purified from the venom of E.carinatus and crystallized using ammonium sulphate as a precipitant. The crystal structure has been determined at 2.4A resolution and refined to an R-factor of 0.187. Overall dimensions of the heterodimer are approximately 80Ax35Ax35A. The backbone folds of the two subunits are similar. The central portions of the polypeptide chains of alpha and beta-subunits move into each other to form a tight dimeric association. The remaining portions of the chains of both subunits fold in a manner similar to those observed in the carbohydrate-binding domains of C-type lectins. In echicetin, the Ca(2+)-binding sites are not present, despite being topologically equivalent to other similar Ca(2+)-binding proteins of the superfamily. The residues Ser41, Glu43 and Glu47 in the calcium-binding proteins of the related family are conserved but the residues Glu126/120 are replaced by lysine at the corresponding sites in the alpha and beta-subunits. PMID:14659748

  2. Pitting corrosion on a copper canister; Gropfraetning paa kopparkapsel

    Energy Technology Data Exchange (ETDEWEB)

    Hermansson, H.P.; Beverskog, B. [Studsvik Material AB, Nykoeping, (Sweden)

    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.

  3. The effect of dichromate ion on the pitting corrosion of AISI 316 stainless steel. Part I: Critical pitting temperature

    International Nuclear Information System (INIS)

    Highlights: • Effect of dichromate ion on critical pitting temperature of SS316 is investigated. • The CPT of 316 SS is increased up to 38 °C in the presence of 0.05 M dichromate. • Dichromate ion decreases the maximum current density in simulated pit solution. • Diffusion controlled limiting current density is decreased by dichromate addition. • Dichromate decreases the pores in lacy cover over the pits mouths. - Abstract: This article provides a better understanding of dichromate effect on the critical pitting temperature (CPT) of 316 SS in chloride solution. Potentiostatic measurements revealed that dichromate effectively improves the CPT. In the presence of dichromate ion, a remarkable decrease in the anodic dissolution in simulated pit environment and a slight decrease in the saturation concentration of cations in pit solution were defined in pencil electrode experiments. Scanning electron microscopy showed that, in compare with pure chloride solution, the pits formed on the metal surface in dichromate containing solution, have finer lacy covers

  4. Studies in pitting corrosion on archaeological bronzes. Copper

    International Nuclear Information System (INIS)

    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.)

  5. 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.

  6. Rifle Pits at Little Bighorn Battlefield National Monument, Montana

    Data.gov (United States)

    National Park Service, Department of the Interior — This is a vector polygon file showing the rifle pits used by the 7th Cavalry at the Reno-Benteen Battlefield at Little Bighorn Battlefield National Monument (LIBI)....

  7. The kinetics of pitting corrosion of carbon steel

    International Nuclear Information System (INIS)

    This report describes progress between April 1986 and May 1987 in a programme studying the kinetics of pitting corrosion in carbon steel containers for the disposal of high level nuclear waste in a granitic repository. Experimental studies are being undertaken with the following objectives: (a) To improve the validation of a mathematical model for the propagation of pitting corrosion. (b) To develop an improved statistical method for analysing experimental pit growth data to take account of the difference in area of laboratory specimens and full size waste containers. (c) To estimate the maximum period during which pitting attack is feasible under repository conditions by calculating the time during which the diffusion of oxygen to the containers will be sufficient to maintain carbon steel in its passive state. Work in the first 14 months of the project has concentrated on (b) and to a lesser extent on (c). (orig./MM)

  8. Relationship Between Foveal Cone Specialization and Pit Morphology in Albinism

    OpenAIRE

    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

    2014-01-01

    Foveal specialization (foveal cone packing, outer segment elongation, pit morphology) in albinism is highly variable and can overlap with normal foveal structure, contrary to the typical clinical picture of albinism.

  9. A Study of the Relation between Current Oscillations and Pitting

    Institute of Scientific and Technical Information of China (English)

    MA, Hou-Yi; YIN, Bing-Sheng; Li, Gui-Yan; GUO, Wen-Juan; CHEN, Shen-Hao; TANG, Kai

    2003-01-01

    Anodic polarization behaviors of iron in pure H2SO4 and three mixed acidic solutions, H2SO4 + NaCl, H2SO4 + NaNO3 and H2SO4 + NaCl + NaNO3, were investigated. The potentiodynamic sweep curves showed that the current densities rose and dropped irregularly in H2SO4 + NaCl solution at the more anodic potentials since the iron surface suffered pitting attack in the solution, but the pitting corrosion was inhibited effectively in the presence of nitrate ions. The surface morphological measurements indicated that pits appeared on the iron surface in H2SO4 + NaCl solution and only a few unobvions corrosion spots were observed in H2SO4 + NaCl + NaNO3 solution after the iron electrode was potentiostatically polarized at 1.3 V. The oscillatory properties of iron are associated with thesusceptibility of the iron to pitting. In H2SO4 + NaCl solution, the regular potentiostatic current oscillations gradually evolved into the irregular current fluctuations due to occurrence of the pitting;whereas in H2SO4 + NaCl + NaNO3 solution, the current oscillations took place regularly, like the oscillatory behavior in the pure H2SO4 solution. Thus, when the higher the oscillatory frequency, the more irregular oscillatory process and the more sensitive to pitting iron occurred.

  10. Deterministic chaos in the pitting phenomena of passivable alloys

    International Nuclear Information System (INIS)

    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-]/[NO3-] 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)

  11. Pitting resistance of stainless steels studied by PPR and CPT tests

    International Nuclear Information System (INIS)

    The effects of alloying elements Cr, Mo and N on the stability of passive film were investigated by measuring Pit Propagation Rate (PPR) and Critical Pitting Temperature(CPT) in aqueous 0.1N H2SO4+0.1N NaCl solution. CPT tests were carried out by measuring the temperature representing the critical current density obtained by increasing temperature at the specific applied potential within passive potential range while PPR tests were conducted by measuring the pit propagation rate obtained by the current density produced due to the pit growth divided by the pit area. The effects of alloying elements Cr, Mo, N on the stability of passive film were investigated by the comparison between CPT and PPR test results in terms of pitting resistance equivalent. PPR test results showed that pit propagation rate was decreased with the increase in Cr, Mo and N contents, indicating the synergistic effect of Mo and N. CPT test results exhibited that the higher contents of Cr, Mo and N, the higher critical pitting temperatures. The synergistic effects of Mo and N on the resistance to pitting corrosion were also observed. As the pitting resistance equivalent increases the passive potential range is extended due to the increased pitting potential. The increase in pitting resistance equivalent also results in the reduction of pit propagation rates, showing the increased critical pitting temperatures. Pitting resistance equivalent may be the good parameter representing the extent of the resistance to pitting corrosion regardless of the kinds of stainless steels

  12. Application of phase shifting interferential microscopy to pitting corrosion studies of ion-implanted stainless steel

    International Nuclear Information System (INIS)

    Phase-shifting interferometry microscopy is applied to the analysis of corrosion pitting of a 304 stainless steel (with and without molybdenum-ion implantation) in NaCl solution. Owing to the dimensions of the pits two kinds of pit can be defined. The statistical analysis of the specimen-inspected field shows that small pits of area 2 are by far the most frequent. The different sizes of the pits can be related to the different stages of pit formation, pre-pitting and growth. (Author)

  13. Crack Initiation from Corrosion Pit in Three Aluminum Alloys Under Ambient and Saltwater Environments

    Science.gov (United States)

    Sabelkin, V.; Misak, H. E.; Perel, V. Y.; Mall, S.

    2016-04-01

    Corrosion-pit-to-crack transition behaviors of three aluminum alloys using two pit configurations were investigated under ambient and saltwater environments. Fatigue stress ranges for crack initiation from a through-pit were less than that from a corner-pit in both environments in all three materials, while stress intensity factor ranges showed the opposite trend. Further, stress ranges or stress intensity factor ranges for crack initiation were less in saltwater than that in ambient environment for both pit configurations. Fatigue damage mechanisms in a test environment were similar for both pit configurations in all three materials. An empirical relationship is proposed to estimate pit-to-crack transition fatigue cycles.

  14. American Religion

    Institute of Scientific and Technical Information of China (English)

    田甜

    2008-01-01

    It is said that American religion,as a great part of American culture,plays an important role in American culture. It is hoped that some ideas can be obtained from this research paper,which focuses on analyzing the great impact is produced to American culture by American religion. Finally, this essay gives two useful standpoints to English learners:Understunding American religion will help understand the American history, culture and American people,and help you to communic.ate with them better. Understanding American religion will help you understand English better.

  15. Crystal structure of the disintegrin heterodimer from saw-scaled viper (Echis carinatus) at 1.9 A resolution.

    Science.gov (United States)

    Bilgrami, Sameeta; Yadav, Savita; Kaur, Punit; Sharma, Sujata; Perbandt, Markus; Betzel, Christian; Singh, Tej P

    2005-08-23

    Disintegrins constitute a family of potent polypeptide inhibitors of integrins. Integrins are transmembrane heterodimeric molecules involved in cell-cell and cell-extracellular matrix interactions. They are involved in many diseases such as cancer and thrombosis. Thus, disintegrins have a great potential as anticancer and antithrombotic agents. A novel heterodimeric disintegrin was isolated from the venom of saw-scaled viper (Echis carinatus) and was crystallized. The crystals diffracted to 1.9 A resolution and belonged to space group P4(3)2(1)2. The data indicated the presence of a pseudosymmetry. The structure was solved by applying origin shifts to the disintegrin homodimer schistatin solved in space group I4(1)22 with similar cell dimensions. The structure refined to the final R(cryst)/R(free) factors of 0.213/0.253. The notable differences are observed between the loops, (Gln39-Asp48) containing the important Arg42-Gly43-Asp44, of the present heterodimer and schistatin. These differences are presumably due to the presence of two glycines at positions 43 and 46 that allow the molecule to adopt variable conformations. A comparative analysis of the surface-charge distributions of various disintegrins showed that the charge distribution on monomeric disintegrins occurred uniformly over the whole surface of the molecule, while in the dimeric disintegrins, the charge is distributed only on one face. Such a feature may be important in the binding of two integrins to a single dimeric disintegrin. The phylogenetic analysis developed on the basis of amino acid sequence and three-dimensional structures indicates that the protein diversification and evolution presumably took place from the medium disintegrins and both the dimeric and short disintegrins evolved from them. PMID:16101289

  16. Evaluation of Ventilated Underground Pit Structures for Yam (Dioscorea Spp) Storage

    OpenAIRE

    T.U. Nwakonobi; S.E. Obetta; H. Iorwtsav

    2012-01-01

    Underground pit structures are commonly employed by farmers for on farm storage of yam (Dioscorea spp) in Nigeria and other parts of developing world. This traditional storage structure is used without provision for adequate air exchange or ventilation. This study investigated the performance of yams stored in underground pit structures provided with air vents. Three experimental pits of similar dimensions were constructed with Pit 1 installed with one PVC vent; Pit 2 had two PVC vents and Pi...

  17. The VIMOS Public Extragalactic Redshift Survey (VIPERS). A precise measurement of the galaxy stellar mass function and the abundance of massive galaxies at redshifts 0.5

    CERN Document Server

    Davidzon, I; Coupon, J; Ilbert, O; Arnouts, S; de la Torre, S; Fritz, A; De Lucia, G; Iovino, A; Granett, B R; Zamorani, G; Guzzo, L; Abbas, U; Adami, C; Bel1, J; Bottini, D; Branchini, E; Cappi, A; Cucciati, O; Franzetti, P; Fumana, M; Garilli, B; Krywult, J; Brun, V Le; Fevre, O Le; Maccagni, D; Malek, K; Marulli, F; McCracken, H J; Paioro, L; Peacock, J A; Polletta, M; Pollo, A; Schlagenhaufer, H; Scodeggio, M; Tasca, L A M; Tojeiro, R; Vergani, D; Zanichelli, A; Burden, A; Di Porto, C; Marchetti, A; Marinoni, C; Mellier, Y; Moscardini, L; Moutard, T; Nichol, R C; Percival, W J; Phleps, S; Wolk, M

    2013-01-01

    We measure the evolution of the galaxy stellar mass function from z=1.3 to z=0.5 using the first 53,608 redshifts of the ongoing VIMOS Public Extragalactic Survey (VIPERS). We estimate the galaxy stellar mass function at several epochs between z=0.5 and 1.3, discussing in detail the amount of cosmic variance affecting our estimate. We find that Poisson noise and cosmic variance of the galaxy mass function in the VIPERS survey are comparable with the statistical uncertainties of large surveys in the local universe. VIPERS data allow us to determine with unprecedented accuracy the high-mass tail of the galaxy stellar mass function, which includes a significant number of galaxies that are usually too rare to detect with any of the past spectroscopic surveys. At the epochs sampled by VIPERS, massive galaxies had already assembled most of their stellar mass. We apply a photometric classification in the (U-V) rest-frame colour to compute the mass function of blue and red galaxies, finding evidence for the evolution...

  18. Envenoming after a snakebite from the Northeast African saw-scaled viper Echis pyramidum: prolonged therapy upon failed treatment by antivenom.

    Science.gov (United States)

    Valenta, J; Stach, Z; Kolář, M

    2011-01-01

    A reptile holder based in the Czech Republic was bitten into his hand and foot by the Northeast saw-scaled viper (Echis pyramidum). The person arrived at the health institution after twenty hours for anuria. Despite the antivenom against the Asian Echis carinatum - the Echis pyramidum's close relative - was readily available and administered repeatedly, the envenoming continued to develop with subsequent coagulopathy, hepatopathy and respiratory failure. The effects of plasmapheresis and symptomatic therapy were positive, but only temporary. Continual renal replacement therapy and plasmapheresis were complicated by thrombotic occlusions of the device tubing set. A turning point arrived following repeated application of imported antivenom containing antigens against venom components of another African saw-scaled viper species, Echis leucogaster (the antivenom containing E. pyramidum antigens was not available). The clinical status, including complications, resolved following 30 days of hospitalization. The case further validates the geographical specifics of immunogenicity of venom components with similar clinical action in snakes of the same genus. PMID:21978783

  19. Characterization of transport mechanisms and determinants critical for Na+-dependent Pi symport of the PiT family paralogs human PiT1 and PiT2

    DEFF Research Database (Denmark)

    Bøttger, Pernille; Hede, Susanne E; Grunnet, Morten; Høyer, Boy; Klaerke, Dan A; Pedersen, Lene

    2006-01-01

    The general phosphate need in mammalian cells is accommodated by members of the P(i) transport (PiT) family (SLC20), which use either Na(+) or H(+) to mediate inorganic phosphate (P(i)) symport. The mammalian PiT paralogs PiT1 and PiT2 are Na(+)-dependent P(i) (NaP(i)) transporters and are...... exploited by a group of retroviruses for cell entry. Human PiT1 and PiT2 were characterized by expression in Xenopus laevis oocytes with (32)P(i) as a traceable P(i) source. For PiT1, the Michaelis-Menten constant for P(i) was determined as 322.5 +/- 124.5 microM. PiT2 was analyzed for the first time and...... showed positive cooperativity in P(i) uptake with a half-maximal activity constant for P(i) of 163.5 +/- 39.8 microM. PiT1- and PiT2-mediated Na(+)-dependent P(i) uptake functions were not significantly affected by acidic and alkaline pH and displayed similar Na(+) dependency patterns. However, only PiT2...

  20. Ion induced changes in the structure of bordered pit membranes

    Directory of Open Access Journals (Sweden)

    Jinkee eLee

    2012-03-01

    Full Text Available Xylem hydraulic resistance varies with ion concentration in sap solution. It is assumed that this variation in resistance results from hydrogel like properties of pectins located in bordered pit membranes separating adjacent vessels. Although kinetics of the resistance change suggests swelling/deswelling behavior of the pectins, there is no direct evidence of this activity. In this report we provide evidence of structural changes in bordered pit membranes responding to variation in ionic concentration of solute around it using atomic force microscopy (AFM. AFM revealed bordered pit membranes as relatively smooth, soft and lacking any sharp edges surface when submerged in de-ionized water, in contrast to pictures from scanning electron microscope (SEM or AFM performed on air dry material. Exposure of the bordered pit membranes to 50 mM KCl solution resulted in significant changes in both surface physical properties with and elevation features as bordered pit membrane became harder, with visible edges of fibers and collapsed, while no change in porosity was observed. Analysis suggests a need for a major shift in our understanding to the physical bases of variable xylem resistance from change in porosity to change in pathway length. Findings support the role of actuating properties of hybrid hydrogel-cellulose materials in water redistribution and embolism resistance.

  1. Detection of cavitation pits on steel surfaces using SEM imagery

    Science.gov (United States)

    Price, Jeffery R.; Hylton, Kathy W.; Tobin, Kenneth W., Jr.; Bingham, Philip R.; Hunn, John D.; Haines, John R.

    2003-04-01

    We describe an automated image processing approach for detecting and characterizing cavitation pits on stainless steel surfaces. The image sets to be examined have been captured by a scanning electron microscope (SEM). Each surface region is represented by a pair of SEM images, one captured before and one after the cavitation-causing process. Unfortunately, some required surface preparation steps between pre-cavitation and post-cavitation imaging can introduce artifacts and change image characteristics in such a way as to preclude simple image-to-image differencing. Furthermore, all of the images were manually captured and are subject to rotation and translation alignment errors as well as variations in focus and exposure. In the presented work, we first align the pre- and post- cavitation images using a Fourier-domain technique. Since pre-cavitation images can often contain artifacts that are very similar to pitting, we perform multi-scale pit detection on each pre- and post-cavitation image independently. Coincident regions labeled as pits in both pre- and post-cavitation images are discarded. Pit statistics are exported to a text file for further analysis. In this paper we provide background information, algorithmic details, and show some experimental results.

  2. W-320 pit liner vs. coating cost risk benefit analysis

    International Nuclear Information System (INIS)

    This report evaluates the costs and the risk trade-offs associated with the two pit lining or confinement options being considered as part of the Tank 241-C-106 Waste Retrieval Project. Both of these pit secondary confinement options (i.e., stainless steel pit liners and epoxy coating) can be implemented in a fashion that complies with criteria for secondary containment systems specified by the Washington Administration Codes (WAC-173-303-604). Direct life cycle costs of the two options including design, fabrication, installation, radiation, exposure, and decontamination and disposal costs are compared. Risk is expressed as probability weighted with the confinement consequences that could be mitigated by the pit liner. The risk impact of the choice of the confinement option is also evaluated in the context of the overall risk associated with the sluicing project and continued storage of the high-heat waste in the Tank 241-C-106 pending completion of the W-320 Project. The two pit secondary containment options are stainless steel line and epoxy coating

  3. Pitting of Incoloy 800 in presence of CuII

    International Nuclear Information System (INIS)

    The pitting behaviour of Incoloy 800 in presence of CuII 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 O2) and deaerated solutions containing 500, 1000, 2000, 10000 and 20000 ppm CuCl2. At 280 degrees C experiments were performed in deaerated 20 ppm, 50 ppm and 100 ppm CuCl2 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 CuCl2. At 60 degrees C pitting was observed in those solutions where the CuCl2 concentration is higher than 1000 ppm. At 280 degrees C pitting was found in the specimens exposed to those solutions where the CuCl2 concentration was higher than 20 ppm. (author). 3 refs

  4. Limiting temperatures for rapid pit propagation in stainless steels

    International Nuclear Information System (INIS)

    A decreasing temperature approach was used to determine critical temperatures for propagation of pitting and crevice corrosion in stainless steels in chloride solutions. Localized attack was made to start and propagate under anodic polarization at an elevated temperature. The temperature was then lowered slowly while retaining the constant potential and monitoring the current. A steep decrease in the current indicated a critical temperature for the propagation of rapid corrosion attack. The test arrangement allowed for a simultaneous development of both crevice type and pit type attack. A series of stainless steels were investigated, including several wrought and cast austenitic grades and some cast duplex stainless steels. The results indicate that a critical temperature may be determined for the rapid growth of pitting type attack. This temperature depends on the composition of the steel and possibly on the pit geometry. For crevice corrosion, however, such a sharp temperature limit could not be determined from the results. For the cast duplex stainless steels the critical temperature of pitting is less pronounced than for the purely austenitic grades

  5. Pitting evaluation on alloy 600 tubings of Kori 1 retired steam generator

    International Nuclear Information System (INIS)

    Pitting on alloy 600 in Kori 1 retired steam generator has been evaluated using results obtained from pulled out tube and repaired tube due to pitting with EFPD. Pitting occured exclusively at crevice between tube and sludge. Pit was filled with corrosion product. The corrosion product was seemed to be a sediment which proceeded following process. At start up, Cu base alloys dissolve due to high dissolved oxygen concentration and then dissolved copper ion or particulate moves through secondary circuit to steam generator. Dissolved oxygen concentration decreases with operating time, so copper ion is reduced. Around pit and them corrosion product was formed inside a pit due to metal dissolution. By repeating the two processes, sediment in pit was formed. Pitting seemed to be caused by influx of sea water through condenser tube, high oxygen concentration, copper ion and sulfur compound detached from resin. Pitting was mitigated by replacement of condenser and preheater material, chemical cleaning and advancement in water chemistry treatment

  6. Evaluation of Ventilated Underground Pit Structures for Yam (Dioscorea Spp Storage

    Directory of Open Access Journals (Sweden)

    T.U. Nwakonobi

    2012-03-01

    Full Text Available Underground pit structures are commonly employed by farmers for on farm storage of yam (Dioscorea spp in Nigeria and other parts of developing world. This traditional storage structure is used without provision for adequate air exchange or ventilation. This study investigated the performance of yams stored in underground pit structures provided with air vents. Three experimental pits of similar dimensions were constructed with Pit 1 installed with one PVC vent; Pit 2 had two PVC vents and Pit 3 without vent which served as control. 20 Kg weight of yams was loaded in each pit measuring 1.0 m in diameter and 0.65 m in depth. The results of the study show that a lowest temperature range of 30-38ºC was maintained in pit 1 (improved temperature range of 34-40ºC in Pit 2 (semi-improved while temperature in pit 3 range from 36- 42ºC. The relative humidity obtained were 84, 76 and 70% in pit 1, 2 and 3 respectively. The sprouting indexes obtained within 8 weeks storage period were 46.2, 53.8 and 76.9 for pit 1, 2 and 3, respectively. The cumulative weight loss obtained in pit 1, 2 and 3 were 44.8, 69.5 and 79.2%, respectively for the 8 weeks storage period. Increased in storage period for yams is possible with adequate ventilation in underground pit structure.

  7. Fukushima nuclear accident recorded in Tibetan Plateau snow pits.

    Directory of Open Access Journals (Sweden)

    Ninglian Wang

    Full Text Available 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.

  8. Nutritional quality evaluation of eighteen date pit varieties.

    Science.gov (United States)

    Habib, Hosam M; Ibrahim, Wissam H

    2009-01-01

    The pits from date palm fruits (Phoenix dactylifera L.) are nutrient dense but the nutrient composition across varieties has not been extensively studied. In the present study, 18 leading varieties of date pits from date fruits cultivated in the United Arab Emirates (Khalas, Barhe, Lulu, Shikat alkahlas, Sokkery, Bomaan, Sagay, Shishi, Maghool, Sultana, Fard, Maktoomi, Naptit Saif, Jabri, Kodary, Dabbas, Raziz and Shabebe) were analyzed and compared for their chemical and physical properties. Dietary fiber, proximate analysis, micronutrients, and physical properties (weight, length, and density) were determined. Significant differences (Pdifferent varieties. The results show that date pits, depending on the variety, contain significant but quite variable amounts of macronutrients and micronutrients, but all varieties are excellent sources of dietary fiber and may therefore serve as important constituents of functional foods. PMID:18925479

  9. 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.

  10. 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 to be...

  11. Pit Distribution Design for Computer-Generated Waveguide Holography

    Science.gov (United States)

    Yagi, Shogo; Imai, Tadayuki; Ueno, Masahiro; Ohtani, Yoshimitsu; Endo, Masahiro; Kurokawa, Yoshiaki; Yoshikawa, Hiroshi; Watanabe, Toshifumi; Fukuda, Makoto

    2008-02-01

    Multilayered waveguide holography (MWH) is one of a number of page-oriented data multiplexing holographies that will be applied to optical data storage and three-dimensional (3D) moving images. While conventional volumetric holography using photopolymer or photorefractive materials requires page-by-page light exposure for recording, MWH media can be made by employing stamping and laminating technologies that are suitable for mass production. This makes devising an economical mastering technique for replicating holograms a key issue. In this paper, we discuss an approach to pit distribution design that enables us to replace expensive electron beam mastering with economical laser beam mastering. We propose an algorithm that avoids the overlapping of even comparatively large adjacent pits when we employ laser beam mastering. We also compensate for the angular dependence of the diffraction power, which strongly depends on pit shape, by introducing an enhancement profile so that a diffracted image has uniform intensity.

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

    International Nuclear Information System (INIS)

    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

  13. Pit and fissure sealant: review of the literature.

    Science.gov (United States)

    Simonsen, Richard J

    2002-01-01

    For this literature review of pit and fissure sealant, 1,465 references were selected by a search for "sealants" on PubMed. References were limited to dental journals and papers in the English language. The search comprised papers from 1971 to October 2001. Additional papers of historical significance prior to 1971 were added from memory and from reference lists published in early papers. This paper reviewed the literature on pit and fissure sealants under the following subheadings: (1) laboratory studies, (2) clinical technique and tooth preparation, (3) etching time, (4) auxiliary application of pit and fissure sealant, (5) retention and caries prevention, (6) fluoride used with sealants and fluoride-containing sealant, (7) glass ionomer materials as sealants, (8) options in sealant: filled vs unfilled; colored vs clear; autocure vs light-initiated, (9) sealant placed over caries in a therapeutic manner, (10) cost effectiveness of sealant application, (11) underuse of pit and fissure sealant, (12) the estrogenicity issue, (13) use of an intermediate bonding layer to improve retention, (14) new developments and projections, and (15) summary and conclusions. From a careful and thorough review of peer-reviewed publications on pit and fissure sealant, it is clear that sealants are safe, effective and underused (at least underused in the United States). Pit and fissure sealant is best applied to high-risk populations by trained auxiliaries using sealant that incorporates the benefit of an intermediate bonding layer, applied under the rubber dam or with some alternative short-term, but effective, isolation technique, onto an enamel surface that has been cleaned with an air polishing technique and etched with 35% phosphoric acid for 15 seconds. The dental profession awaits with enthusiasm, and some impatience, the incorporation of dentin-bonding technology into the development of a modern, more durable, resin-based sealant. PMID:12412954

  14. Pitting corrosion of copper in nuclear waste disposal environments

    International Nuclear Information System (INIS)

    A literature survey on pitting corrosion of copper and polarisation experiments found that chloride, sulphate, carbonate and nitrate ions together with dissolved oxygen will be likely to promote the pitting corrosion of copper in groundwaters. Other components that can be expected to have some effect are Ca2+, Fe3+ and HS- ions, and H2O2 from radiolysis. The pH of the water also seems to be important while the temperature only is of minor importance. From these literature findings an experimental matrix was derived for experiments to possibly verify environments that could cause pitting corrosion. As the experiments have continued, some alterations have been made to the matrix as a feed-back from the current experimental results. Basically it was found that the corrosion of copper in the synthetic groundwater is dominated by the high salt concentration (mainly NaCl). A high salt content gives an environment that inhibits the formation of a passive layer on the surface. Only in a few cases is there a clear evidence for a passive layer formation in such an environment. With no passive layer on the surface, general corrosion dominates and pitting is less likely to occur. Two species were found that are more likely to cause pitting corrosion of the copper surface under repository conditions, namely sulphide and carbonate ions (HS- and HCO3-). Groundwater with HCO3- was forming a passive layer at pH 8.5 that was penetrated locally during the polarisation scan and thereby opened the surface to pitting corrosion. With HS-, a surface film was formed immediately after immersion, and the corrosion potential moved to very low values. During the polarisation scan there was an extensive formation of whiskers (dendrites formed through reactions between copper ions and sulphide) on the copper surface at high anodic potentials

  15. Pre-clinical assays predict pan-African Echis viper efficacy for a species-specific antivenom.

    Directory of Open Access Journals (Sweden)

    Nicholas R Casewell

    Full Text Available BACKGROUND: Snakebite is a significant cause of death and disability in subsistent farming populations of sub-Saharan Africa. Antivenom is the most effective treatment of envenoming and is manufactured from IgG of venom-immunised horses/sheep but, because of complex fiscal reasons, there is a paucity of antivenom in sub-Saharan Africa. To address the plight of thousands of snakebite victims in savannah Nigeria, the EchiTAb Study Group organised the production, testing and delivery of antivenoms designed to treat envenoming by the most medically-important snakes in the region. The Echis saw-scaled vipers have a wide African distribution and medical importance. In an effort to maximise the clinical utility of scarce antivenom resources in Africa, we aimed to ascertain, at the pre-clinical level, to what extent the E. ocellatus-specific EchiTAbG antivenom, which was designed specifically for Nigeria, neutralised the lethal activity of venom from two other African species, E. pyramidum leakeyi and E. coloratus. METHODOLOGY/PRINCIPAL FINDINGS: Despite apparently quite distinctive venom protein profiles, we observed extensive cross-species similarity in the immuno-reactivity profiles of Echis species-specific antisera. Using WHO standard pre-clinical in vivo tests, we determined that the monospecific EchiTAbG antivenom was as effective at neutralising the venom-induced lethal effects of E. pyramidum leakeyi and E. coloratus as it was against E. ocellatus venom. Under the restricted conditions of this assay, the antivenom was ineffective against the lethal effects of venom from the non-African Echis species, E. carinatus sochureki. CONCLUSIONS/SIGNIFICANCE: Using WHO-recommended pre-clinical tests we have demonstrated that the new anti-E. ocellatus monospecific antivenom EchiTAbG, developed in response to the considerable snakebite-induced mortality and morbidity in Nigeria, neutralised the lethal effects of venoms from Echis species representing each

  16. Development of an automated pit packaging system for Pantex

    Energy Technology Data Exchange (ETDEWEB)

    Fahrenholtz, J.C.

    1997-09-01

    Sandia National Laboratories is developing a system that uses robots to package pits at Pantex in the AT-400A pit storage and transportation container. This report will give an overview of the AT-400A packaging process, and the parts of the overall AT-400A packaging operation that will be performed robotically. The process employed to move from development in the laboratory at Sandia to production use at Pantex will be described. Finally, important technology components being developed for and incorporated into the robotic system will be described. 7 refs., 9 figs.

  17. Cut winnings methods of an open-pit mine development

    OpenAIRE

    Ivana Cehlárová; Michal Cehlár

    2007-01-01

    Surface mining is an extremely significant process of acquisition of a substantial amount of minerals serving the needs of human society. The open-pit mining process is characterized by horizontal removal of a huge amount of blasted rock. The deposit is often mined in several horizontal sections. The deposits may be mined via so-called shelf quarries, which are quarries created in the hill slope or via so-called pit quarries where the quarry is established in the terrain lacking the camber an...

  18. Ablation layers to prevent pitting in laser peening

    Energy Technology Data Exchange (ETDEWEB)

    Hackel, Lloyd A

    2016-08-09

    A hybrid ablation layer that comprises a separate under layer is applied to a material to prevent pitting resulting from laser peening. The underlayer adheres to the surface of the workpiece to be peened and does not have bubbles and voids that exceed an acceptable size. One or more overlayers are placed over and in contact with the underlayer. Any bubbles formed under the over layers are insulated from the surface to be peened. The process significantly reduces the incidence of pits on peened surfaces.

  19. In situ Raman identification of stainless steels pitting corrosion films

    International Nuclear Information System (INIS)

    Raman spectroscopy is used for the in situ identification of the corrosion products grown during the pitting corrosion of stainless steels in presence of NaCl. To obtain a better approach of these complicated materials, binary alloys are first investigated, in which the alloying element is present in the same ratio as in steel. Here, results on Fe-10%Ni and Fe-18%Cr, AISI304 and AISI316 are presented and the respective parts played by chromium and molybdenum in the prevention of pitting corrosion are described. The outer product, ''colloidal'' green rust (GR) ,is particularly studied and a GR formula is proposed

  20. Improving pitting corrosion resistance of aluminum by anodizing process

    International Nuclear Information System (INIS)

    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)

  1. Reconstitution of clathrin-coated pit budding from plasma membranes

    OpenAIRE

    1991-01-01

    Receptor-mediated endocytosis begins with the binding of ligand to receptors in clathrin-coated pits followed by the budding of the pits away from the membrane. We have successfully reconstituted this sequence in vitro. Highly purified plasma membranes labeled with gold were obtained by incubating cells in the presence of anti-LDL receptor IgG-gold at 4 degrees C, attaching the labeled cells to a poly-L-lysine- coated substratum at 4 degrees C and then gently sonicating them to remove everyth...

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Ziying [Department of Materials Science, Fudan University, Shanghai 200433 (China); Key Laboratory of Ecophysics, Department of Physics, Shihezi University, Shihezi 832003 (China); Xinjiang Laboratory of Phase Transitions and Microstructures in Condensed Matters, Yili Normal University, Yining 835000 (China); Han Dong; Jiang Yiming; Shi Chong [Department of Materials Science, Fudan University, Shanghai 200433 (China); Li Jin, E-mail: jinli@fudan.edu.cn [Department of Materials Science, Fudan University, Shanghai 200433 (China)

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer The relationship between pitting corrosion resistance and annealing temperature for UNS S32304 was systemically studied. Black-Right-Pointing-Pointer The specimens annealed at 1080 Degree-Sign C for 1 h, quenched in water exhibit the best pitting corrosion resistance. Black-Right-Pointing-Pointer The relationship between microstructural evolution and pitting resistance of annealed UNS S32304 was discussed in detail. Black-Right-Pointing-Pointer 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 Degree-Sign 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 Degree-Sign 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.

  4. 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.

  5. 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…

  6. 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…

  7. 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…

  8. 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…

  9. 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…

  10. 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…

  11. 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…

  12. 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…

  13. Pitted and Hybrid Morningglory Accessions Have Variable Tolerance to Glyphosate

    Science.gov (United States)

    Greenhouse studies were conducted to investigate the variability in tolerance to glyphosate among 38 accessions of pitted morningglory collected from several southern United States. Glyphosate at 420 g ae/ha was applied postemergence to plants at 4- to 5-leaf stage and control was visually estimated...

  14. The kinetics of pitting corrosion of carbon steel

    International Nuclear Information System (INIS)

    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 cm2) 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)

  15. Recultivation of the cavity of the closed open pit Bor

    Directory of Open Access Journals (Sweden)

    Lilić Jasmina

    2008-01-01

    Full Text Available Copper ore is one of the most important raw materials for industrial production. Increasing demands have been increasing its extraction generally. Shallow deposits with higher copper grade are mostly exhausted and the open pits become deeper, also the amount of overburden and the problems of its disposal are increased. In some cases large quantities of overburden can solve the problem of recultivation of degraded areas. This is the case of recultivation of degraded areas on the location of the closed open pit Bor. Here, the overburden from another open pit, Veliki Krivelj, is disposed into the cavity of the open pit Bor. In this way the overburden is disposed without further area degradation and the cavity is primarily, technically recultivated. When the filling process is finished, waste depot will have a flat top at the level K+450 [2], which is above the neighboring terrain, and the slopes height will vary. This problem was not especially considered up to date, so the experiences in this field are humble. This paper intends to be the basis for further research.

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

    International Nuclear Information System (INIS)

    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

  17. Black Butte switches to laser for mapping open pit mines

    Energy Technology Data Exchange (ETDEWEB)

    Corbley, K.P. [Corbley Communications Inc., Littleton, CO (USA)

    2001-03-01

    The Black Butte Coal Co. has turned to a new laser-based mapping technology called Light Detection and Ranging, LIDAR, for mapping the topography of surface mines. The system, known as the Remote Airborne Mapping System (RAMS), is provided by EnerQuest Systems LLC of Denver. In four projects at the 63-square mile Black Butte operation, advanced airborne LIDAR has demonstrated advantage over aerial photography in terms of timeliness and convenience for mapping coal seams in an open-pit mine. LIDAR uses a scanning laser altimeter to directly measure the latitude, longitude and elevation coordinates of ground points by emitting light pulses towards the ground from the unit in the aircraft. Black Butte mine uses a dragline for overburden stripping. 3-D models of the pit and seams are created with Minescape software. The LIDAR system allows modeling of overburden to determine the position of the economic cutoff by mapping outside the pit: mapping inside the pit enables the 3-D model to be checked. 1 fig., 1 photo.

  18. Olanzapine-induced tender pitting pre-tibial edema

    OpenAIRE

    Kaliaperumal Mathan; Venkatesan Muthukrishnan; Vikas Menon

    2015-01-01

    Antipsychotic-induced edema is uncommonly encountered in clinical practice. We report a case of tender pitting pre-tibial edema with olanzapine in a woman with no medical comorbidities. The peculiar distribution of edema resulted in diagnostic confusion necessitating specific investigations. Eventually, the edema resolved following complete stoppage of the drug, but caused distress to the patient and the caregiver.

  19. 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.

  20. Olanzapine-induced tender pitting pre-tibial edema

    Directory of Open Access Journals (Sweden)

    Kaliaperumal Mathan

    2015-01-01

    Full Text Available Antipsychotic-induced edema is uncommonly encountered in clinical practice. We report a case of tender pitting pre-tibial edema with olanzapine in a woman with no medical comorbidities. The peculiar distribution of edema resulted in diagnostic confusion necessitating specific investigations. Eventually, the edema resolved following complete stoppage of the drug, but caused distress to the patient and the caregiver.

  1. THE PITS PROPERTY OF ENTIRE FUNCTIONS DEFINED BY DIRICHLET SERIES

    Institute of Scientific and Technical Information of China (English)

    Shang Lina; Gao Zongsheng

    2009-01-01

    The value distribution of entire functions defined by Dirichlet series are studied in this present article. It is proved that entire functions defined by Dirichlet series have the pits property, which improve the relative results on lacunary Taylor series obtained by Littlewood J.E. and Offord A.C.

  2. The effect of dichromate ion on the pitting corrosion of AISI 316 stainless steel Part II: Pit initiation and transition to stability

    International Nuclear Information System (INIS)

    Highlights: • Effect of dichromate ion on pitting corrosion of 316 SS is investigated by a statistical approach. • Dichromate ion increases the value of both corrosion and breakdown potentials. • Dichromate ion decreases the initiation frequency of metastable pitting. • Dichromate hinders the transition from metastable to stale pitting. • Survival probability of stable pits is increased in dichromate containing solution. - Abstract: The effect of dichromate ions on the corrosion behaviour of 316 stainless steel was investigated in 0.1 M NaCl solution by electrochemical measurements and electron microscopy. The results revealed that the addition of dichromate increases the resistance to pitting corrosion as the pitting corrosion does not occur in the presence of 0.05 M dichromate ions at room temperature. The mechanistic studies showed that the increase in pitting corrosion resistance in presence of Cr2O72− is due to the decrease in the metastable pit initiation, lower kinetics of metastable pit dissolution and increase in the survival probability of the pit formation

  3. Micro Pulsed Inductive Thruster with Solid Fuel Option (uPIT_SF) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Micro Pulsed Inductive Thruster with Solid Fuel Option (5PIT_SF) is a high-precision impulse bit electromagnetic plasma micro-thruster. The 5PIT prototype is a...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. Purification of a basic phospholipase A2 from Indian saw-scaled viper (Echis carinatus) venom: characterization of antigenic, catalytic and pharmacological properties.

    Science.gov (United States)

    Kemparaju, K; Prasad, B N; Gowda, V T

    1994-10-01

    A major basic phospholipase A2 was purified from the Indian saw-scaled viper (Echis carinatus) venom by the combination of column chromatography and electrophoresis. The purified phospholipase A2 (EC-IV-PLA2) has a mol. wt of 14,000 by SDS-PAGE. It is a basic protein with a pI value between 7.2 and 7.6, and has a fluorescence emission maxima at 340 nm. It induces neurotoxicity and oedema in mice with an i.p. LD50 of 5 mg/kg body weight. It is devoid of direct haemolytic, myotoxic, cytotoxic and anticoagulant activities. Rabbit polyclonal antibodies prepared against EC-IV-PLA2 inhibited the in vitro enzymatic activity dose dependently, but did not neutralize the toxic effects of EC-IV-PLA2 in experimental animals. PMID:7846689

  6. Purification and characterization of a platelet aggregation inhibitor acidic phospholipase A2 from Indian saw-scaled viper (Echis carinatus) venom.

    Science.gov (United States)

    Kemparaju, K; Krishnakanth, T P; Veerabasappa Gowda, T

    1999-12-01

    An acidic phospholipase A2 (EC-I-PLA2) has been purified from the Indian saw-scaled viper (Echis carinatus) venom through a combination of column chromatography and electrophoresis. EC-I-PLA2 has a molecular weight of 16000 by SDS-PAGE. It was focussed between pH 4.2 and 4.8 by isoelectro focussing. EC-I-PLA2 was non-lethal to mice and devoid of neurotoxicity, myotoxicity, anticoagulant activity and cytotoxicity. It induced mild oedema in the foot pads of mice. The purified PLA2 inhibited ADP, collagen and epinephrine induced human platelet aggregation and the inhibition was both dose and time dependent. PMID:10519645

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

    OpenAIRE

    Gadang Priyotomo

    2013-01-01

    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 pitt...

  8. "Pit Craters", lava tubes, and open vertical volcanic conduits in Hawaii: a problem in terminology

    OpenAIRE

    William R. Halliday

    1998-01-01

    Almost from the 1849 publication of the term pit crater, volcanologists have disagreed about the parameters differentiating these features from other vertical volcanic structures. Kaluaiki is a jameo giving entry to Thurston Lava Tube in Hawaii Volcanoes National Park. Long-standing misidentification of it as a pit crater is an example of misunderstandings arising from the lack of a clear definition of pit crater. In general, pit craters are unrelated to lava tube caves genetically, but two s...

  9. The Feature of Deformation at Convex Corner of Deep Foundation Pit Based on FLAC3D

    OpenAIRE

    ZHAO Shun-li; Zhang, Guang; LI Mo-xiao; REN Qing-guo

    2016-01-01

    The study on the space-time feature of foundation pit deformation has important significance to ensure the stability of foundation pit engineering. In the present study, the relationship between the space-time fractal feature of foundation pit deformation and the stability of the foundation pit has not been studied adequately. By combining the concrete engineering example, used the FLAC3D software for numerical simulation, and the simulated values were compared with the actual value. Finally,...

  10. The Space-Time Fractal Feature of Deformation at Convex Corner of Deep Foundation Pit

    OpenAIRE

    ZHAO Shun-li; LIU Bao-zhi

    2016-01-01

    The study on the space-time feature of foundation pit deformation has important significance to ensure the stability of foundation pit engineering. In the present study, the relationship between the space-time fractal feature of foundation pit deformation and the stability of the foundation pit is expressed with simple indexes, such as the time and position of the maximum value of deformation. By combining the concrete engineering example, the fractal theory is introduced, and the correlation...

  11. The eroded pit that coming from the tracks of nucleus's fission and its meaning

    International Nuclear Information System (INIS)

    The traditional method of studying nucleon tracks is to erode the samples, which contain nucleon tracks, by erosive liquid so that the tracks will be enlarged into micron quantity level. Observing through microscope, these tracks look like little pits. In this paper, the authors also find out the same pits in samples, although these samples have not been eroded. The authors analyze the causation of these eroded pits, and point out the geologic effect of these pits. (author)

  12. Recipes for the fabrication of strictly ordered Ge islands on pit-patterned Si(001) substrates

    International Nuclear Information System (INIS)

    We identify the most important parameters for the growth of ordered SiGe islands on pit-patterned Si(001) substrates. From a multi-dimensional parameter space we link individual contributions to isolate their influence on ordered island growth. This includes the influences of: the pit size, pit depth and pit period on the Si buffer layer and subsequent Ge growth; the pit sidewall inclination on Ge island growth; the amount of Ge on island morphologies as well as the influences of the pit-size homogeneity, the pit period, the Ge growth temperature and rate on island formation. We highlight that the initial pit shape and pit size in combination with the growth conditions of the Si buffer layer should be adjusted to provide suitable preconditions for the growth of Ge islands with the desired size, composition and nucleation position. Furthermore, we demonstrate that the wetting layer between pits can play the role of a stabilizer that inhibits shape transformations of ordered islands. Thus, dislocation formation within islands can be delayed, uniform arrays of one island type can be fabricated and secondary island nucleation between pits can be impeded. These findings allow us to fabricate perfectly ordered and homogeneous Ge islands on one and the same sample, even if the pit period is varied from a few hundred nanometres to several micrometres. (paper)

  13. Limitations of using a thermal imager for snow pit temperatures

    Directory of Open Access Journals (Sweden)

    M. Schirmer

    2013-10-01

    Full Text Available Driven by temperature gradients, kinetic snow metamorphism is important for avalanche formation. Even when gradients appear to be insufficient for kinetic metamorphism, based on temperatures measured 10 cm apart, faceting close to a~crust can still be observed. Recent studies that visualized small scale (< 10 cm thermal structures in a profile of snow layers with an infrared (IR camera produced interesting results. The studies found melt-freeze crusts to be warmer or cooler than the surrounding snow depending on the large scale gradient direction. However, an important assumption within the studies was that a thermal photo of a freshly exposed snow pit was similar enough to the internal temperature of the snow. In this study, we tested this assumption by recording thermal videos during the exposure of the snow pit wall. In the first minute, the results showed increasing gradients with time, both at melt-freeze crusts and at artificial surface structures such as shovel scours. Cutting through a crust with a cutting blade or a shovel produced small concavities (holes even when the objective was to cut a planar surface. Our findings suggest there is a surface structure dependency of the thermal image, which is only observed at times with large temperature differences between air and snow. We were able to reproduce the hot-crust/cold-crust phenomenon and relate it entirely to surface structure in a temperature-controlled cold laboratory. Concave areas cooled or warmed slower compared with convex areas (bumps when applying temperature differences between snow and air. This can be explained by increased radiative transfer or convection by air at convex areas. Thermal videos suggest that such processes influence the snow temperature within seconds. Our findings show the limitations of the use of a thermal camera for measuring pit-wall temperatures, particularly in scenarios where large gradients exist between air and snow and the interaction of snow

  14. Impacts of swine manure pits on groundwater quality

    International Nuclear Information System (INIS)

    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 δ15N and δ18O 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

  15. The effect of Alloying elements on pitting resistance of ferritic and austenitic stainless steels in terms of pitting resistance equivalents (PRE)

    International Nuclear Information System (INIS)

    The alloying elements, such as Cr, Mo, and N of stainless steels play important roles in their resistances to pitting corrosion. The pitting resistances of stainless steels ha e long been characterized in terms of electrochemical parameters such as pitting potentials. however, in order to better understand the resistances to pitting of stainless steels, Pit Propagation Rate (PPR) and Critical Pitting Temperature (CPT) tests were carried out in deaerated 0.1N H2SO4 + 0.1N NaCl solution. The effect of Cr, Mo, and N alloying elements on the pitting corrosion resistances of both ferritic Fe-Cr, Fe-Cr-Mo stainless steels and austenitic stainless steels was examined by performing polarization, PPR, and CPT tests. The comparison between test results was made in terms of the Pitting Resistance Equivalent (PRE). Results showed that PRE values are the good parameters representing the extents of pitting corrosion resistance on a single scale regardless of both kinds of alloying elements and types of ferritic or austenitic stainless steels

  16. Pitting of steam-generator tubing alloys in solutions containing thiosulfate and sulfate or chloride.

    Science.gov (United States)

    Zhang, William; Carcea, Anatolie G; Newman, Roger C

    2015-01-01

    The pitting of nuclear steam generator tubing alloys 600, 690 and 800 was studied at 60 °C using dilute thiosulfate solutions containing excess sulfate or (for Alloy 600) chloride. A potentiostatic scratch method was used. In sulfate solutions, all alloys pitted at low potentials, reflecting their lack of protective Mo. The alloys demonstrated the most severe pitting at a sulfate : thiosulfate concentration ratio of ∼40. Alloy 600 pitted worst at a chloride : thiosulfate ratio of ∼2000. The results are interpreted through the mutual electromigration of differently charged anions into a pit nucleus, and differences in the major alloy component. PMID:25898311

  17. Study on determination of the stable slope configuration for deep open pit mine

    Institute of Scientific and Technical Information of China (English)

    Nai-long ZHU; Shi-xiong ZHANG; Shu-yu YUE

    2008-01-01

    The space effects of deep pit slope are analyzed by an elastic mechanics principle.The interaction among the critical slide angle,the friction coefficient,the cohesion,and the horizontal radius of the deep pits is derived in this paper.It indicates that the deeper the pit is excavated,the greater the critical slide angle is.Both the theory for reducing stripping waste rock in deep pit and the approach to determining the configuration of the stable slope are developed from the interaction.The theory in this paper comprises the preceding principles of stability analysis of slopes and is suitable for analyzing that of deep pit.

  18. 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 relati

  19. Predictive Index for slope instabilities in open pit mining

    CERN Document Server

    Ortega, J H; Lecaros, R; Medel, F; Padilla, F; García, A

    2016-01-01

    In this paper we study the stability and deformation of structures, in particular the wall of an open pit mine is studied by using information obtained from a variety of remote sensors and some extra data, with a novelty approach considering the use of mathematical models and data mining techniques. In particular we present two models to help the study the slope stability of pit and the possible occurrence of movements. Primarily we present an static model for slow movements, which will help us identify areas of possible risks areas with time horizons of several months or years, depends on the available information, before the wall start moving, and secondly a dynamic short-term model, which help us to determine risks of collapse zones with several days in advance. We remark that this methodology can be a powerful tool to plain future actions in order to simulate possible scenarios considering the production plans.

  20. Geologic report for the Weldon Spring Raffinate Pits Site

    Energy Technology Data Exchange (ETDEWEB)

    None

    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.

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

    International Nuclear Information System (INIS)

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

  2. The influence of tungsten on the pitting of aluminum films

    International Nuclear Information System (INIS)

    Many of the alloying additions responsible for the corrosion resistance of stainless steels can also be used to enhance the passivity of aluminum, provided that these elements remain in solid solution in the alloy. Passivity enhancing elements such as Cr, Mo, Ta, Zr, and W typically exhibit very low solubility limits in aluminum, below 1 atomic percent, and at these concentrations exert little influence on corrosion behavior. However, these solubility limits can be increased with a concomitant enhancement in corrosion performance if the alloys are produced using a rapid solidification process. One such process is co-sputter deposition of two metals, such as Al and W, simultaneously to form a binary alloy of W in solid solution with Al. Co-sputter deposition is routinely used to produce compound semiconductor films. The authors report on shifts in pitting potentials and on the effect of a transition element (W) on pitting resistance of Al

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

    International Nuclear Information System (INIS)

    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)

  4. Pulsed Laser-Induced Micro-Pits: As Bone Stabilizers

    Science.gov (United States)

    Çelen, Serap; Efeoğlu, Candan; Özden, Hüseyin

    Mechanical interlocking concept is a crucial criteria for osseointegration which is based on micro-porous surface structures. Several surface treatment methods have been used to modify the surface morphology of titanium implants in order to increase the effective interfacial area. The aim of the present preliminary study is two folds: to develop 3D finite element models for micro-pits on implant surfaces as bone stabilizers in order to evaluate the mechanical response of interfacial area and compare the estimated interfacial shear strength and the maximum effective shear strain with other biomechanical theories. Second is to produce novel regular micro-pit patterns using a 20 Watt ytterbium fiber laser and characterize these novel micro-stabilizers.

  5. Geologic report for the Weldon Spring Raffinate Pits Site

    International Nuclear Information System (INIS)

    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

  6. Cut winnings methods of an open-pit mine development

    International Nuclear Information System (INIS)

    Surface mining is an extremely significant process of acquisition of a substantial amount of minerals serving the needs of human society. The open-pit mining process is characterized by horizontal removal of a huge amount of blasted rock. The deposit is often mined in several horizontal sections. The deposits may be mined via so-called shelf quarries, which are quarries created in the hill slope or via so-called pit quarries where the quarry is established in the terrain lacking the camber and the quarry is 'deepened' in the depth direction by gradual mining. A combined way is also possible, when after the initial mining in the shelf quarry, mining continues to altitudes under the surrounding level. (authors)

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

    International Nuclear Information System (INIS)

    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.

  8. 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.

  9. The Feature of Deformation at Convex Corner of Deep Foundation Pit Based on FLAC3D

    Directory of Open Access Journals (Sweden)

    ZHAO Shun-li

    2016-03-01

    Full Text Available The study on the space-time feature of foundation pit deformation has important significance to ensure the stability of foundation pit engineering. In the present study, the relationship between the space-time fractal feature of foundation pit deformation and the stability of the foundation pit has not been studied adequately. By combining the concrete engineering example, used the FLAC3D software for numerical simulation, and the simulated values were compared with the actual value. Finally, we researched on the relationship between the foundation pit deformation and the stability of foundation pit. Research showed that FLAC3D could reveal the complex spatial and temporal characteristics of foundation pit deformation. But compared with the actual monitoring value, it still has some limitations.

  10. 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.

  11. Aspirated pits in wetwood and micromorphology of microbial degradation in subalpine fir

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yaoli; CAI Liping; XU Yongji

    2006-01-01

    Differentiating from normal wood,pit membranes in wetwood of subalpine fir contain bacteria of water drop shape or orbicular shape,and flaky shape,as observed using Scanning Electronic Microscope.Not only are ray parenchyma cells in wetwood partially degraded but also margo strands in pit membranes are somewhat degraded by bacterial activities.Most of the bordered-pit membranes in normal wood are unaspirated in green conditions and the proportions of aspirated pits in earlywood and latewood account for only 6.8% and 13.4%,respectively.Nevertheless,most of the bordered-pit membranes in wetwood are aspirated in green conditions and the proportions of aspirated pits account for 77.7% and 72.1%,respectively.The problem of hard-to-dry for subalpine fir could be reasoned from the considerable amount of aspirated pit membranes in wetwood.

  12. Data Summary Report D-Area Burning/Rubble Pits

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-10-01

    The purpose of this report is to verify that all analytical data collected at the D-Area Burning/Rubble Pits at the Savannah River Site for use in developing risk assessment and potential remediation procedures have been validated at the appropriate level. Any discrepancies or reasons why the data should be rejected for this purpose will be addressed. This report documents the data validation procedures used by Environmental Monitoring Section, Exploration Resources, and RUST Environment {ampersand} Infrastructure for Assigning qualifiers.

  13. Acidification of the cytosol inhibits endocytosis from coated pits

    OpenAIRE

    1987-01-01

    Acidification of the cytosol of a number of different cell lines strongly reduced the endocytic uptake of transferrin and epidermal growth factor. The number of transferrin binding sites at the cell surface was increased in acidified cells. Electron microscopic studies showed that the number of coated pits at the cell surface was not reduced in cells with acidified cytosol. Experiments with transferrin- horseradish peroxidase conjugates and a monoclonal anti-transferrin receptor antibody demo...

  14. Investigation of foundation pit excavation influence on adjacent buildings

    OpenAIRE

    Zertsalov Mikhail Grigor'evich; Kazachenko Sergey Andreevich; Konyukhov Dmitriy Sergeevich

    2014-01-01

    Modern urban policies, particularly in major towns, involve the active use of underground space that poses the problem of assessing the impact of excavation on the existing buildings as one of the most urgent. Surface and semi-closed construction methods are currently widespread in the process of urban civil and transport underground facilities construction. The depth of excavation can reach 30 m, but more often, in everyday practice common foundation pits have shallower depth, accommodating ...

  15. Restoration and conservation of sand and gravel-sand pits

    Czech Academy of Sciences Publication Activity Database

    Řehounková, Klára; Řehounek, J.

    Praha : Agentura ochrany přírody a krajiny České republiky, 2012 - (Jongepierová, I.; Pešout, P.; Jongepier, J.; Prach, K.), s. 94-96 ISBN 978-80-87457-32-0 R&D Projects: GA ČR(CZ) GAP505/11/0256 Institutional research plan: CEZ:AV0Z60050516 Institutional support: RVO:67985939 Keywords : restoration * conservation * sand pits Subject RIV: EH - Ecology, Behaviour

  16. 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.

  17. Cormorant predation on PIT-tagged lake fish

    Directory of Open Access Journals (Sweden)

    Christian Skov

    2014-02-01

    Full Text Available 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 to be the most vulnerable of the three species and based on a comparison with mortality estimates from lakes without significant avian predation, this study suggest that predation from cormorants can induce age/size truncation in lake Viborg, leaving very few larger perch in the lake. This truncation reduces the likelihood of anglers catching a large perch and may also influence lower trophic levels in the lake and thus turbidity as large piscivorous perch often play an important structuring role in lake ecosystem functioning.

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

    International Nuclear Information System (INIS)

    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

  19. Quantification of the chemical exergy of the acai pit

    Energy Technology Data Exchange (ETDEWEB)

    Mendes, Manoel do Espirito Santo dos Santos [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Lab. de Engenharia Mecanica. LABGAS]. E-mail: manoelssmendes@hotmail.com; Nogueira, Manoel Fernandes Martins [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Lab. de Engenharia Mecanica]. E-mail: mfmn@ufpa.br

    2008-07-01

    The exergy became a tool more and more important for project and analysis of thermal systems because it supplies base for term-economy discussion. Systems that use combustion of biomass have difficulties to calculate the chemical exergy of the process of combustion due to the uncertainties in the quantification of the chemical exergy of the biomass, falling back upon expressions of approximate values. This work presents a methodology to quantify the chemical exergy of biomass and it exemplifies the calculation at chemical exergy for acai pit. Such calculates starts with the results from ultimate and proximate analysis of acai pit. Following, the acai pit chemical exergy is quantified and compared with values from another method. The proposed methodology can be applied for any biomass and determines the chemical exergy of the dry biomass free from ashes, only the ash chemical exergy and finally contribution of the water contained in the biomass, thus assisting the exergetic analysis of thermal systems using biomass of the Amazon region as combustible for energy generation. (author)

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

    International Nuclear Information System (INIS)

    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 m3 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 m3 of old solid radwaste with competitive costs and in complete safety and protection of the environment. (authors)

  1. 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; Pedersen, Lene

    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 of...

  2. Effect of annealing temperature on the pitting corrosion resistance of super duplex stainless steel UNS S32750

    Energy Technology Data Exchange (ETDEWEB)

    Tan Hua; Jiang Yiming; Deng Bo; Sun Tao; Xu Juliang [Department of Material Science, Fudan University, Shanghai 200433 (China); Li Jin, E-mail: jinli@fudan.edu.cn [Department of Material Science, Fudan University, Shanghai 200433 (China)

    2009-09-15

    The pitting corrosion resistance of commercial super duplex stainless steels SAF2507 (UNS S32750) annealed at seven different temperatures ranging from 1030 deg. C to 1200 deg. C for 2 h has been investigated by means of potentiostatic critical pitting temperature. The microstructural evolution and pit morphologies of the specimens were studied through optical/scanning electron microscope. Increasing annealing temperature from 1030 deg. C to 1080 deg. C elevates the critical pitting temperature, whereas continuing to increase the annealing temperature to 1200 deg. C decreases the critical pitting temperature. The specimens annealed at 1080 deg. C for 2 h exhibit the best pitting corrosion resistance with the highest critical pitting temperature. The pit morphologies show that the pit initiation sites transfer from austenite phase to ferrite phase as the annealing temperature increases. The aforementioned results can be explained by the variation of pitting resistance equivalent number of ferrite and austenite phase as the annealing temperature changes.

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

    Energy Technology Data Exchange (ETDEWEB)

    Galuszka-Muga, Barbara

    2005-05-19

    An investigation was undertaken of the effect of gamma radiation on metastable pitting of mild carbon steels immersed in a solution similar to those existing at high level waste (HLW) deposits in the US. The object was to observe the extent to which a dosage rate of 1 Mrad/hour (10 Kgrey/hour) affected measurable electrochemical parameters such as pitting potential, open circuit potential, rate of metastable pitting and repassivation potential. Methods for reliably measuring electrochemical potentials in a high radiation field were developed. Exploratory analyses were made of the ion product release and electrolyte composition change in a confined volume simulating the conditions of a corrosion initiated pit during gamma irradiation. As expected the results indicated that the metastable pitting rate (as well as the general rate of corrosion) was significantly enhanced by a radiation field.

  4. Observation of etch pits in Fe-36wt%Ni Invar alloy

    Institute of Scientific and Technical Information of China (English)

    Dong-zhu Lu; Min-jie Wu

    2014-01-01

    To indirectly investigate the dislocation behavior of Fe−36wt%Ni Invar alloy by the etch pit method, polished Invar specimens were etched by a solution containing 4 g copper sulfate, 20 mL hydrochloric acid, and 20 mL deionized water for 2 min. Etch pits in the etched surfaces were observed. All the etch pits in one specific grain exhibited similar shapes, which are closely related to the grain orienta-tions. These etch pits were characterized as dislocation etch pits. It was observed that etch pits arranged along grain boundaries, gathered at grain tips and strip-like etch pit clusters passed through a number of grains in the pure Invar specimens. After the addition of a small amount of alloying elements, the identification of a single dislocation etch pit is challenging compared with the pure Invar alloy. Thus, the observa-tion of etch pits facilitates the investigation on the dislocation behavior of the pure Invar alloy. In addition, alloying elements may affect the densities and sizes of etch pits.

  5. 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. PMID:25754548

  6. Testing the 'rare pit' hypothesis for xylem cavitation resistance in three species of Acer.

    Science.gov (United States)

    Christman, Mairgareth A; Sperry, John S; Adler, Frederick R

    2009-01-01

    Eudicot angiosperms with greater vulnerability to xylem cavitation tend to have vessels with greater total area of inter-vessel pits, which inspired the 'rare pit' hypothesis: the more pits per vessel, by chance the leakier will be the vessel's single air-seeding pit and the lower the air-seeding threshold for cavitation to spread between vessels. Here, we demonstrate the feasibility of the hypothesis, using probability theory to model the axial propagation of air through air-injected stems. In the presence of rare, leaky pits, air-seeding pressures through short stems with few vessel ends in series should be low; pressures should increase in longer stems as more end-walls must be breached. Measurements on three Acer species conformed closely to model predictions, confirming the rare presence of leaky pits. The model indicated that pits air-seeding at or below the mean cavitation pressure (MCP) occurred at similarly low frequencies in all species. Average end-wall air-seeding pressures predicted by the model closely matched species' MCPs. Differences in species' vulnerability were primarily attributed to differences in frequency of the leakiest pits rather than pit number or area per vessel. Adjustments in membrane properties and extent of pitting per vessel apparently combine to influence cavitation resistance across species. PMID:19434805

  7. Mud Pit Identification Report, Nevada Test Site, Nevada (September 2001, Rev. No. 0); FINAL

    International Nuclear Information System (INIS)

    The U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Operations Office (NNSA/NV) and the Nevada Division of Environmental Protection completed the Mud Pit Strategy, Nevada Test Site (NTS), Nevada (DOE/NV, 2001) to document a systematic process for identifying and categorizing potentially contaminated mud pits located on the NTS, and systematically evaluating them for inclusion in the Federal Facility Agreement and Consent Order (FFACO). The objectives of this report are to summarize the process used to define the six mud pit categories, identify mud pits, discuss the mud pits that do not meet FFACO entry criteria, identify mud pits for proposed FFACO entry, and describe the general mud pit distribution. Underground nuclear testing conducted since 1951 at the NTS has produced mud pits that were used for the transfer and collection of drilling mud, rock cuttings, and drilling fluids. This report documents the execution of the strategy document by examining the identification process and documenting these results. For clarification purposes, this document uses the term ''entry'' to indicate inclusion of mud pits into the FFACO and ''exclusion'' to indicate those mud pits which do not meet the ''entry'' criteria defined in this report. Based on this criteria, 257 mud pits identified that have been proposed for FFACO entry were found in 14 separate areas of the NTS. Each of the 257 mud pits proposed for FFACO entry will need to be located in the field, photographed, and documented during future Industrial Sites Project, Preliminary Assessment activities. If the field review determines that a mud pit was misidentified or improperly categorized, the appropriate FFACO modification request will be submitted for review and approval

  8. Online Design Aid for Evaluating Manure Pit Ventilation Systems to Reduce Entry Risk.

    Science.gov (United States)

    Manbeck, Harvey B; Hofstetter, Daniel W; Murphy, Dennis J; Puri, Virendra M

    2016-01-01

    On-farm manure storage pits contain both toxic and asphyxiating gases such as hydrogen sulfide, carbon dioxide, methane, and ammonia. Farmers and service personnel occasionally need to enter these pits to conduct repair and maintenance tasks. One intervention to reduce the toxic and asphyxiating gas exposure risk to farm workers when entering manure pits is manure pit ventilation. This article describes an online computational fluid dynamics-based design aid for evaluating the effectiveness of manure pit ventilation systems to reduce the concentrations of toxic and asphyxiating gases in the manure pits. This design aid, developed by a team of agricultural engineering and agricultural safety specialists at Pennsylvania State University, represents the culmination of more than a decade of research and technology development effort. The article includes a summary of the research efforts leading to the online design aid development and describes protocols for using the online design aid, including procedures for data input and for accessing design aid results. Design aid results include gas concentration decay and oxygen replenishment curves inside the manure pit and inside the barns above the manure pits, as well as animated motion pictures of individual gas concentration decay and oxygen replenishment in selected horizontal and vertical cut plots in the manure pits and barns. These results allow the user to assess (1) how long one needs to ventilate the pits to remove toxic and asphyxiating gases from the pit and barn, (2) from which portions of the barn and pit these gases are most and least readily evacuated, and (3) whether or not animals and personnel need to be removed from portions of the barn above the manure pit being ventilated. PMID:27303661

  9. Online Design Aid for Evaluating Manure Pit Ventilation Systems to Reduce Entry Risk

    Directory of Open Access Journals (Sweden)

    Harvey B. Manbeck

    2016-05-01

    Full Text Available On-farm manure storage pits contain both toxic and asphyxiating gases such as hydrogen sulfide, carbon dioxide, methane and ammonia. Farmers and service personnel occasionally need to enter these pits to conduct repair and maintenance tasks. One intervention to reduce the toxic and asphyxiating gas exposure risk to farm workers when entering manure pits is manure pit ventilation. This article describes an online computational fluid dynamics based design aid for evaluating the effectiveness of manure pit ventilation systems to reduce the concentrations of toxic and asphyxiating gases in the manure pits. This design aid, developed by a team of agricultural engineering and agricultural safety specialists at Pennsylvania State University, represents the culmination of more than a decade of research and technology development effort. The article includes a summary of the research efforts leading to the online design aid development and describes protocols for using the online design aid, including procedures for data input and for accessing design aid results. Design aid results include gas concentration decay and oxygen replenishment curves inside the manure pit and inside the barns above the manure pits, as well as animated motion pictures of individual gas concentration decay and oxygen replenishment in selected horizontal and vertical cut plots in the manure pits and barns. These results allow the user to assess: (1 how long one needs to ventilate the pits to remove toxic and asphyxiating gases from the pit and barn, (2 from which portions of the barn and pit these gases are most and least readily evacuated, and (3 whether or not animals and personnel need to be removed from portions of the barn above the manure pit being ventilated.

  10. American ginseng

    Science.gov (United States)

    ... Some research suggests that taking a specific American ginseng extract called CVT-E002 (Cold-FX, Afexa Life Sciences, ... AD-fX, Afexa Life Sciences, Canada) containing American ginseng extract in combination with ginkgo leaf extract might help ...

  11. The kinetics of pitting corrosion of carbon steel applied to evaluating containers for nuclear waste disposal

    International Nuclear Information System (INIS)

    This is the final summary report on a project, funded by SKB, investigating the pitting corrosion of carbon steel containers for high level nuclear waste or spent reactor fuel under granite disposal conditions. The study has covered a statistically based experimental programme to establish the pit growth kinetics, and a modelling study to determine the maximum pitting period subsequent to repository closure. It is shown that the rate of pit propagation is slower than that suggested by earlier work and that the maximum pitting period is only a small fraction of the target container life of 1000 years. An illustrative example of the methodology for estimating the corrosion allowance needed to prevent pit penetration is given. This could be applied to specific repository conditions as defined by SKB. Finally some limited recommendations are made for further studies to test and validate the methodology. (au)

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

    International Nuclear Information System (INIS)

    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. 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.

  14. 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)

  15. Finite element analysis and modeling of water absorption by date pits during a soaking process.

    Science.gov (United States)

    Waezi-Zadeh, Motahareh; Ghazanfari, Ahmad; Noorbakhsh, Shahin

    2010-07-01

    Date pits for feed preparation or oil extraction are soaked in water to soften before milling or extrusion. Knowledge of water absorption by the date pits helps in better managing the soaking duration. In this research, the process of water absorption by date pits was modeled and analyzed using Fick's second law of diffusion, finite element approach, and Peleg model. The moisture content of the pits reached to its saturation level of 41.5% (wet basis) after 10 d. The estimated coefficient of diffusion was 9.89x10(-12) m(2)/s. The finite element model with a proposed ellipsoid geometry for a single date pit and the analytical model fitted better to the experimental data with R(2) of 0.98. The former model slightly overestimated the moisture content of the pits during the initial stages of the soaking and the latter model generally underestimated this variable through the entire stages of soaking process. PMID:20593512

  16. 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.

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

    International Nuclear Information System (INIS)

    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)

  18. Development of specimen preparation techniques for pitting potential measurement of irradiated fuel cladding tubes

    International Nuclear Information System (INIS)

    By the effect of the Great East Japan Earthquake, seawater was injected into spent fuel pools in unit 2, 3 and 4 at Fukushima Daiichi nuclear plant in order to cool spent fuels. It is known that chloride ion contained in seawater could cause pitting corrosion for metallic materials. It was concerned that radioactive products inside of fuel cladding tubes might be escaped through the pits. Therefore we have investigated the pit initiation condition of fuel cladding tubes by measuring pitting potential in order to evaluate stability of the enclosure function of fuel cladding tubes in spent fuel pools containing sea salt. In this report, we describe the development of specimen preparation techniques for pitting measurement of spent fuel cladding tubes having high radioactivity. By accomplishing of the development of the specimen preparation techniques, we could evaluate pit initiation condition of spent fuel cladding tubes in water containing sea salt. (author)

  19. El calcio nutriente para las plantas. Bitter pit en manzano

    OpenAIRE

    Monge Pacheco, Emilio; Val Falcón, Jesús; Sanz Encinas, Manuel; Blanco Braña, Álvaro; Montañés García, Luis

    1995-01-01

    Al present, bitter pit is an unsolved problem despite of the different points of view under which it has been approached. It appears in some orchads in a intermittent way. In this paper, some of the factors that induce or contribute to the development of this disorder are discussed.These factors depend on the soil (high availability of K and/or Mg, hot and dry soils), on the plant (inhibited transpiration, excessive imbalance between leaf mass and fruit, restricted root growth, rootstocks and...

  20. Pit Profile Simulation for HD DVD Mastering Process

    Science.gov (United States)

    Yamamoto, Ryousuke; Matsumaru, Masaaki; Nakamura, Naomasa

    2007-06-01

    We constructed an HD DVD mastering process simulator on the basis of the cell removal model. In the exposure process, we simulated the exposure profile in the photoresist film. In the development process, we defined the density and development rate of the unit cell. We carried out iterative calculation for each unit cell dissolution. The development rate was approximated as the function of the exposure intensity profile. From the results, we were able to simulate the three-dimension (3D) pit profiles of HD DVD-ROM (read only memory). We clarified that our development rate equation is similar to Hirai et al. and Trefonas and Daniels’ type equation in semiconductor lithography.

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

    International Nuclear Information System (INIS)

    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

  2. Chuqui introduces hydraulic shovel into its pit operations

    Energy Technology Data Exchange (ETDEWEB)

    Wyllie, R.J.M.

    1988-01-01

    The first O and K RH 300 hydraulic shovel to be used in a hard rock open pit went into service in October 1987 in Codelco Chile's Chuquicamata copper mine. Electricity to power the RH 300 and other electric machines at Chuquicamata is generated in the new-coal-fired section of the company's Tocopilla power plant. The plant is fired by coal mined several thousand km away at the new Pecket coal mine in southern Chile by another fleet of O and K hydraulic shovels.

  3. El teorema de Pitágoras en la escuela

    OpenAIRE

    Echavarría, Carlos; Bermúdez, Catalina

    2011-01-01

    Este taller estará dirigido a docentes de la educación básica y media y personas en general que estén interesados en conocer estrategias para la enseñanza del teorema de Pitágoras, en este se mostrarán algunos rompecabezas y se estudiaran, además se mostraran a través de una metodología llamada Aula Taller y finalmente se harán reflexiones alrededor de la enseñanza de la geometría en la escuela.

  4. Superficial drainage studies in open-pit mines

    International Nuclear Information System (INIS)

    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.)

  5. Sensitivity to thermal stimulation in prairie rattlesnakes (Crotalus viridis) after bilateral anesthetization of the facial pits

    Energy Technology Data Exchange (ETDEWEB)

    Chiszar, D.; Dickman, D.; Colton, J.

    1986-01-01

    Six yearling prairie rattlesnakes (Crotalus viridis) were exposed to thermal stimuli prior to and after bilateral anesthetization of their facial pits with 2% xylocaine solution. This treatment eliminates trigeminally mediated electrophysiological responses of the pits to thermal stimulation. Nevertheless, the rattlesnakes continued to exhibit behavioral responses to thermal cues after anesthetization of the pits. An auxiliary infrared-sensitive system, nociceptors, or the common temperature sense could be responsible for these findings.

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

    International Nuclear Information System (INIS)

    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)

  7. PRELIMINARY PLANKTON INVESTIGATIONS IN THE GRAVEL PIT AND WINTERPONDS NEAR JAGODNO

    OpenAIRE

    Marija Tomec

    2007-01-01

    Investigations of plankton populations have been performed in the gravel pit and two winterponds near the place Jagodno, Novo Čiće, in the vicinity of Velika Gorica. Our goal was to examine plankton composition of the gravel pit and winterponds, two ecosystems characterized by specific life–conditions which change with time and space. Investigations were conducted during June 2007. Plankton samples were collected from water surface layer at four locations (two locations in the gravel pit and ...

  8. 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.

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

    OpenAIRE

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

    2014-01-01

    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 corrosio...

  10. Cleft lip and palate, lower lip pits, and limb deficiency defects.

    OpenAIRE

    Küster, W; Lambrecht, J T

    1988-01-01

    Cleft lip or palate and lower lip pits are typical features of the autosomal dominantly inherited Van der Woude syndrome. Limb defects have not been reported in this syndrome so far. A girl with a unilateral complete cleft lip and palate, bilateral lower lip pits, and amniotic deformities of all four limbs is reported and the possibility of chance occurrence of cleft lip and palate, lower lip pits, and limb defects is discussed.

  11. Inhibition Mechanism of Pitting Corrosion of Nickel in Aqueous Medium by Some Macrocyclic Compounds

    OpenAIRE

    Fatma Mohamed Mahgoub; Ahmed Mohamed Hefnawy

    2012-01-01

    Anodic polarization of nickel was studied by potentiostatic technique in neutral media in presence of two macrocyclic ligands. Pit initiation was detected by measuring pitting potential, Ep and the charge transfer, Q during the anodic polarization. Initiation of pitting and Q were found to be dependent on the structure and concentrations of inhibitors. Under steady state conditions, the inhibition efficiency was in the order 1, 4, 8, 11 tetraazacyclotetradecane (

  12. Endocytosis of activated receptors and clathrin-coated pit formation: deciphering the chicken or egg relationship

    OpenAIRE

    1996-01-01

    The fundamental mechanisms by which receptors once targeted for endocytosis are found in coated pits is an important yet unresolved question. Specifically, are activated receptors simply trapped on encountering preexisting coated pits, subsequently being rapidly internalized? Or do the receptors themselves, by active recruitment, gather soluble coat and cytosolic components and initiate the rapid assembly of new coated pits that then mediate their internalization? To explore this question, we...

  13. Crystallization and preliminary X-ray crystallographic analysis of blood coagulation factor V-activating proteinase (RVV-V) from Russell’s viper venom

    International Nuclear Information System (INIS)

    The crystallization and preliminary X-ray crystallographic analysis of blood coagulation factor V-activating proteinase are reported. The best crystal diffracted to 1.9 Å resolution. Russell’s viper venom blood coagulation factor V activator (RVV-V) is a thrombin-like serine proteinase that specifically activates factor V by cleaving a single peptide bond between Arg1545 and Ser1546. Activated factor V combines with activated factor X produced by the enzyme RVV-X in the venom to form the prothombinase complex, which can induce disseminated intravascular coagulopathy in envenomated animals. In the current study, RVV-V was crystallized in order to attempt to understand its substrate specificity for factor V. Four distinct crystal forms of RVV-V were obtained using the sitting-drop vapour-diffusion method and diffraction data sets were collected on SPring-8 beamlines. The best crystal of RVV-V generated data sets to 1.9 Å resolution

  14. Mitochondrial phylogeny shows multiple independent ecological transitions and northern dispersion despite of Pleistocene glaciations in meadow and steppe vipers (Vipera ursinii and Vipera renardi).

    Science.gov (United States)

    Zinenko, Oleksandr; Stümpel, Nikolaus; Mazanaeva, Lyudmila; Bakiev, Andrey; Shiryaev, Konstantin; Pavlov, Aleksey; Kotenko, Tatiana; Kukushkin, Oleg; Chikin, Yury; Duisebayeva, Tatiana; Nilson, Göran; Orlov, Nikolai L; Tuniyev, Sako; Ananjeva, Natalia B; Murphy, Robert W; Joger, Ulrich

    2015-03-01

    The phylogeny and historical demography of small Eurasian vipers of the Vipera ursinii and V. renardi complexes were studied using mitochondrial DNA sequences analysed with Bayesian inference, Maximum Likelihood and Maximum Parsimony approaches, and mismatch distributions. Diversification in the group resulted from an initial dispersion in the later Pliocene - Pleistocene in two directions: north-westwards via the Balkans (V. ursinii complex) and north-eastwards from Asia Minor via the Caucasus (V. renardi complex). An independent, comparatively recent transition occurred from montane habitats to lowland grasslands in different mitochondrial lineages during the Late Pleistocene, when representatives of the both complexes had reached lowland steppes to the north. Effective population size showed clear signs of rapid growth in eastern V. renardi, triggered by colonization of vast lowland steppes, but in western V. ursinii complex grew during the Last Glaciation and experienced stabilization in Holocene. Expansion and population growth in lowland lineages of V. renardi was not strongly affected by Pleistocene climatic oscillations, when cold, dry conditions could have favoured species living in open grasslands. The high diversity of closely related haplotypes in the Caucasus and Tien-Shan could have resulted from repetitive expansion-constriction-isolation events in montane regions during Pleistocene climate fluctuations. The mitochondrial phylogeny pattern conflicts with the current taxonomy. PMID:25527984

  15. Determination of in vivo toxicity and in vitro cytotoxicity of venom from the Cypriot blunt-nosed viper Macrovipera lebetina lebetina and antivenom production

    Directory of Open Access Journals (Sweden)

    A Nalbantsoy

    2012-01-01

    Full Text Available The venomous Levantine viper, Macrovipera lebetina lebetina is endemic to Cyprus. The objective of this study was to investigate in vitro cytotoxicity, in vivo lethality, and antivenom production followed by a re-immunization schedule in mice against Macrovipera lebetina lebetina venom. The LD50 value was estimated as 7.58 mg/kg within 24 hours by different venom doses administrated intraperitoneally in mice. Freund's complete and incomplete adjuvants were used for first and second immunization of mice in antivenom production. A cell-based assay was performed to determine the effects of Macrovipera lebetina lebetina venom and antivenom neutralizing potency on L929 cell viability. The snake venom toxicity and cytotoxicity were examined and comparison of results showed good correlation, the LD50 value was tenfold higher than the IC50 value. The IC50 value was 0.62 ± 0.18 mL after 48 hours treatment while the calculated value was 1.62 ± 0.25 mL for the culture media totally refreshed after two hours treatment with venom. The in vitro efficacy of antivenom against Macrovipera lebetina lebetina venom was found to be low. This is the first report that describes the in vivo and in vitro toxic effects of Macrovipera lebetina lebetina venom and antivenom production against this species.

  16. Neurotoxicity, haemostatic disturbances and haemolytic anaemia after a bite by a Tunisian saw-scaled or carpet viper (Echis 'pyramidum'-complex): failure of antivenom treatment.

    Science.gov (United States)

    Gillissen, A; Theakston, R D; Barth, J; May, B; Krieg, M; Warrell, D A

    1994-08-01

    A young man in Germany was bitten by a large captive saw-scaled viper (Echis 'pyramidum'-complex) of Tunisian origin. During the first few hours after the bite he developed evidence of disseminated intravascular coagulation and fibrinolysis, and bled spontaneously. Despite being given a total of 310 ml of three different Echis-specific antivenoms (together with large amounts of fresh frozen plasma and concentrated clotting factors), venom antigenaemia (measured by enzyme immunoassay) and coagulopathy persisted for more than 10 days, and he developed a haemolytic anaemia and mild renal dysfunction. Transient bilateral ptosis was attributed to envenoming. The venom of the snake responsible for the bite was immunologically distinct from that of Nigerian E. ocellatus and was clearly not neutralised by the three monospecific antivenoms which had been administered. This case is another illustration of the geographical variation in snake venoms and the need for pooling venoms from snakes from different parts of the geographical range in the preparation of antivenoms. Envenoming by North African Echis species may not be reversible by available antivenoms. PMID:7985198

  17. Purification, crystallization and preliminary crystallographic analysis of a natural complex of phospholipase A2 from Echis carinatus (saw-scaled viper).

    Science.gov (United States)

    Nagpal, A; Chandra, V; Kaur, P; Singh, T P

    1999-06-01

    A novel complex of phospholipase A2 complexed with another venom protein has been isolated and purified from saw-scaled viper (Echis carinatus) venom. The molecular weights of the two components are 16 and 14 kDa, respectively. The complex was purified using an Affigel blue column and an anion-exchange (DEAE Sephacel) column. Long diamond-shaped crystals were obtained by hanging-drop vapour diffusion. The protein complex was dissolved at a concentration of 10 mg ml-1 in 20 mM sodium cacodylate, 1 mM CaCl2 and 2% dioxane at pH 6.0. The reservoir contained the same buffer with 7%(w/v) PEG 4000. Crystals appeared within 2-3 weeks. Native data to 2.9 A resolution have been obtained at 291 K. The crystals belong to the monoclinic space group P21 with unit-cell parameters a = 74.47, b = 47.87, c = 106.39 A, beta = 104.5 degrees and contain two molecules per asymmetric unit. Structure determination by molecular replacement is in progress. PMID:10329797

  18. Effects of three novel metalloproteinases from the venom of the West African saw-scaled viper, Echis ocellatus on blood coagulation and platelets.

    Science.gov (United States)

    Howes, J-M; Kamiguti, A S; Theakston, R D G; Wilkinson, M C; Laing, G D

    2005-06-20

    Two metalloproteinases, a 24-kDa P-I EoVMP1 and a 56-kDa P-III EoVMP2, have recently been isolated from the venom of the West African saw-scaled viper Echis ocellatus. We now reveal a new 65-kDa haemorrhagic group P-III metalloproteinase which we have designated EoVMP3. The aim of this study was to determine whether these three snake venom metalloproteinases (SVMPs) affect platelets and blood coagulation. EoVMP1 had no effect on the aggregation of washed human platelets, whereas EoVMP2 inhibited collagen-induced platelet aggregation. In contrast, EoVMP3 did not inhibit the aggregation of platelets by collagen but instead activated platelets in the absence of any additional co-factors. All three SVMPs were capable of activating prothrombin to varying degrees and can therefore be described as procoagulants. EoVMP1, EoVMP2 and EoVMP3 share sequence identity with other members of the reprolysin family, but differ greatly in their effects on some of the components that control haemostasis. PMID:15863354

  19. Structure of an acidic phospholipase A2 from Indian saw-scaled viper (Echis carinatus) at 2.6 A resolution reveals a novel intermolecular interaction.

    Science.gov (United States)

    Jasti, Jayasankar; Paramasivam, M; Srinivasan, A; Singh, T P

    2004-01-01

    The crystal structure of an acidic phospholipase A(2) from the venom of Echis carinatus (saw-scaled viper; scPLA(2)) has been determined at 2.6 A resolution and refined to a crystallographic R factor of 0.192. Although the overall structure of scPLA(2) is essentially similar to those of other group II acidic PLA(2)s from different species, it shows unique features in several parts. Particularly noteworthy is the C-terminal part, which folds differently to those of other group II PLA(2)s. This part is considered to be responsible for inhibition of the platelet-aggregation activity. The calcium-binding loop is tightly organized with sevenfold coordination. Another striking feature of scPLA(2) is the involvement of Asn79 O(delta1) of a symmetry-related molecule in a coordination linkage with Ca(2+) of the calcium-binding loop. This is the first observation of an internal metal ion participating in an intermolecular interaction. The beta-wing of a molecule is deeply inserted into the hydrophobic channel of another molecule and forms several intermolecular interactions. This results in the formation of an infinite chain of molecules. These chains are stacked in an antiparallel arrangement in the crystals. PMID:14684894

  20. Cytotoxic activities of [Ser⁴⁹]phospholipase A₂ from the venom of the saw-scaled vipers Echis ocellatus, Echis pyramidum leakeyi, Echis carinatus sochureki, and Echis coloratus.

    Science.gov (United States)

    Conlon, J Michael; Attoub, Samir; Arafat, Hama; Mechkarska, Milena; Casewell, Nicholas R; Harrison, Robert A; Calvete, Juan J

    2013-09-01

    Fractionation by reversed-phase HPLC of venom from four species of saw-scaled viper: Echis ocellatus, Echis pyramidum leakeyi, Echis carinatus sochureki, and Echis coloratus led to identification in each sample of an abundant protein with cytotoxic activity against human non-small cell lung adenocarcinoma A549 cells. The active component in each case was identified by MALDI-TOF mass fingerprinting of tryptic digests as [Ser⁴⁹]phospholipase A₂ ([Ser⁴⁹]PLA₂). An isoform of [Ser⁴⁹]PLA₂ containing the single Ala¹⁸→ Val substitution and a partially characterized [Asp⁴⁹]PLA₂ were also present in the E. coloratus venom. LC₅₀ values against A549 cells for the purified [Ser⁴⁹]PLA₂ proteins from the four species are in the range 2.9-8.5 μM. This range is not significantly different from the range of LC₅₀ values against human umbilical vein endothelial HUVEC cells (2.5-12.2 μM) indicating that the [Ser⁴⁹]PLA₂ proteins show no differential anti-tumor activity. The LC₅₀ value for [Ser⁴⁹]PLA₂ from E. ocellatus against human erythrocytes is >100 μM and the MIC values against Escherichia coli and Staphylococcus aureus are >100 μM. It is suggested that the [Ser⁴⁹]PLA₂ proteins play a major role in producing local tissue necrosis and hemorrhage at the site of envenomation. PMID:23747272

  1. 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).

  2. 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

    A novel method has been developed to fabricate nanoscale pits on Au(111) in aqueous environments by in situ scanning tunnelling microscopy (STM), based on critical interactions between tip and substrate. The most striking advantages of the present method are that the dimension and position 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 by...

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

    Energy Technology Data Exchange (ETDEWEB)

    MINTEER, D.J.

    2000-09-19

    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.

  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. 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.

  6. The Space-Time Fractal Feature of Deformation at Convex Corner of Deep Foundation Pit

    Directory of Open Access Journals (Sweden)

    ZHAO Shun-li

    2016-03-01

    Full Text Available The study on the space-time feature of foundation pit deformation has important significance to ensure the stability of foundation pit engineering. In the present study, the relationship between the space-time fractal feature of foundation pit deformation and the stability of the foundation pit is expressed with simple indexes, such as the time and position of the maximum value of deformation. By combining the concrete engineering example, the fractal theory is introduced, and the correlation dimension is calculated with the measured deformation data for a period of time. By combining the concrete engineering example, the fractal theory was introduced, and used the correlation dimension calculated with the measured deformation data to analyze the space-time fractal feature of deformation at convex corner. Further researched on the relationship between the correlation dimension of the foundation pit deformation and the stability of foundation pit. The research showed that the correlation dimension could reveal the complex space-time feature of the foundation pit deformation. From the aspects of time, the correlation dimension is related to the foundation pit condition, construction disturbance, the change of supporting structure and so on, and has a certain degree of decline with time. From the aspects of space, the difference of correlation dimension between stable and unstable regions is relatively large while there is little difference in the stability region. With the correlation dimension, it is more easily to identify the stable and the unstable regions of the foundation pit, compared with the accumulated deformation.

  7. Microscopic investigation of pitting corrosion in plasma nitrided austenitic stainless steel

    International Nuclear Information System (INIS)

    UNS 31603 austenitic stainless steel was nitrided using different techniques, and pitting corrosion resistance was analysed in a chloride solution. All nitriding techniques, LEII, PI. and convectional DC nitriding produced a nitrided layer called S phase which is corrosion resistant. Pits morphology and layer structure was investigated using optical and electronic microscopy, SEM-FIB, EDS, and a 3D reconstruction of a pit was assessed using FIB tomography. It was concluded that pits are initiated in MnS inclusions and a channel was generated passing through the nitrided layer, connecting the steel with the electrolyte. Base alloy dissolution was observed beneath the nitrided layer.

  8. Effect of nitrite concentration on pit depth in carbon steel exposed to simulated radioactive waste

    International Nuclear Information System (INIS)

    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

  9. INTER-TRACHEID AND CROSS-FIELD PITTING IN COMPRESSION AND OPPOSITE WOOD OF

    Directory of Open Access Journals (Sweden)

    Asghar Tarmian

    2009-02-01

    Full Text Available Inter-tracheid and cross-filed pit pairs in compression and opposite wood of Norway spruce (Picea abies were examined. The size, appearance, and frequency of bordered pits on the radial side of axial tracheids and their aperture specification were studied. The type, size, and number of half-bordered pits between the axial tracheids and rays per cross-field were also studied. Several techniques were employed for the measurements: Environmental Scanning Electron Microscope (ESEM, Scanning Electron Microscope (SEM, Light Microscope (LM, and the Frankling method (FM. The structure, size, and frequency of both types of the pits varied between compression and opposite wood. Fewer pits of a smaller size and a smaller aperture diameter were observed in compression wood. The uniseriate arrangement of bordered pit pairs, unpitted tracheid walls, circular- or often slit-like pit aperture, dominantly piceoid but sometimes cupressoid and occasionally taxodioid cross-field pitting, and a number of fissures on the tracheid walls and bordered pits were characteristics of compression wood.

  10. The dissolution vessel for plutonium pits at the U.S. DOE Pantex Plant.

    Science.gov (United States)

    Eifert, E J; Vickers, L D

    2000-02-01

    The U.S. DOE Pantex Plant has been given the mission to recertify and requalify plutonium pits for reuse in existing War Reserve nuclear weapons. The first process common to both recertification and requalification is cleaning the plutonium pit. The pit will be cleaned in a dissolution vessel using N-methyl pyrrolidone (NMP) solvent. The recertification and requalification programs are both in the design concept phase at Pantex Plant The U.S. DOE Pantex Plant secures the national security of the United States by using safe vessels for cleaning plutonium pits in a manner that protects the health and safety of employees, the public and the environment. PMID:10651401

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

  13. TRANSITIONS IN ELECTROCHEMICAL NOISE DURING PITTING CORROSION OF ALUMINUM IN CHLORIDE ENVIRONMENTS

    International Nuclear Information System (INIS)

    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

  14. Finite element analysis and modeling of water absorption by date pits during a soaking process

    OpenAIRE

    Waezi-Zadeh, Motahareh; Ghazanfari, Ahmad; Noorbakhsh, Shahin

    2010-01-01

    Date pits for feed preparation or oil extraction are soaked in water to soften before milling or extrusion. Knowledge of water absorption by the date pits helps in better managing the soaking duration. In this research, the process of water absorption by date pits was modeled and analyzed using Fick’s second law of diffusion, finite element approach, and Peleg model. The moisture content of the pits reached to its saturation level of 41.5% (wet basis) after 10 d. The estimated coefficient of ...

  15. 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.

  16. Off-line tests on pitting damage in mercury target

    International Nuclear Information System (INIS)

    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)

  17. Treatment of pit water from uranium mining operation

    International Nuclear Information System (INIS)

    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

  18. Modeling of light intensification by conical pits within multilayer coatings

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, S R; Wolfe, J E; Monterrosa, A; Feit, M D; Pistor, T V; Stolz, C J

    2009-11-02

    Removal of laser-induced damage sites provides a possible mitigation pathway to improve damage resistance of coated multilayer dielectric mirrors. In an effort to determine the optimal mitigation geometry which will not generate secondary damage precursors, the electric field distribution within the coating layers for a variety of mitigation shapes under different irradiation angles has been estimated using the finite difference time domain (FDTD) method. The coating consists of twenty-four alternating layers of hafnia and silica with a quarter-wave reflector design. A conical geometrical shape with different cone angles is investigated in the present study. Beam incident angles range from 0{sup o} to 60{sup o} at 5{sup o} increments. We find that light intensification (square of electric field, |E|{sup 2}) within the multilayers depends strongly on the beam incident direction and the cone angle. By comparing the field intensification for each cone angle under all angles of incidence, we find that a 30{sup o} conical pit generates the least field intensification within the multilayer film. Our results suggest that conical pits with shallow cone angles ({le} 30{sup o}) can be used as potential optimal mitigation structures.

  19. 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...

  20. Increasing the service life of cross ties at open pits

    Energy Technology Data Exchange (ETDEWEB)

    Tikhomirov, A.I.

    1981-01-01

    An analysis shows that the service life of cross ties on mobile tracks should be at least 6 years; on permanent ones, 11-12 years. Cross tie failure at open pits is greatly affected by frequent relaying of tracks during mining work, the significant dynamic and static loads when the rail lengths separate (up to 80-100 kN/length in the summer and 150-160 kN in the winter), instability of the soil foundation, movement of the cross ties when the gage is expanded, weakening of joints, etc. Improving their service life is affected by the ballast quality, heavier rail types, separate bolt and wood screw attachments, elastic liners between the tie plate and cross tie, and autoclave impregnation of the cross ties with oil antiseptics. Repair of old cross ties is an indispensable condition for extending their service life. At open pits, cross tie repair should be done at track repair and assembly stations with standard MPS cross tie repair shop equipment.

  1. Interim covering of waste pit 4 at the feed materials production center

    International Nuclear Information System (INIS)

    The Feed Materials Production Center (FMPC) is a Department of Energy (DOE) owned facility operated by Westinghouse Materials Company of Ohio (WMCO) for the purpose of producing metallic uranium fuel elements, target cores, and other uranium compounds. These materials are used at other DOE facilities in support of the US defense program. In the past, disposal of waste generated from production operations at the FMPC was accomplished by constructing waste disposal pits and landfilling the waste. As a result of this practice, the FMPC has six waste disposal pits which contain many different types of waste including uranium, thorium, construction rubble, fly ash and various other wastes unique to the FMPC. None of the waste disposal pits are currently operated for the disposal of waste and all six pits are being investigated under a sitewide Remedial Investigation/Feasibility Study to determine what effect the pits are having on the environment. Waste Pit 4 is unique among the six pits in that it contains an amount of mixed (hazardous/radioactive) waste and has been classified under the Resource Conservation and Recovery Act as a hazardous waste landfill. For this reason the US Environmental Protection Agency requested that the US DOE consider interim closure of Waste Pit 4 to prevent surface water infiltration. To meet this request, WMCO developed the Cover for Pit 4 project which involves placing subgrade fill onto the existing pit surface to form a domed cap over the pit, covering the cap with 0.6 meters of clay compacted to 10-7 cm/sec permeability, and installing a 1.1 millimeter reinforced Hypalon cover over the clay. This paper will detail the design process with the associated problems and solutions and the projected construction sequence

  2. Microbiologically influenced corrosion of stainless steels - What is required for pitting?

    Energy Technology Data Exchange (ETDEWEB)

    Hakkarainen, T.J. [VTT Industrial Systems, P.O. Box 1704, FIN-02044 VTT (Finland)

    2003-07-01

    Pitting of stainless steels in environments normally regarded as completely harmless is often attributed to microbial activity. In this paper, attention is drawn on one hand to the basic requirements for pitting of stainless steels to be possible, and on the other hand to various ways how microbial activity could contribute to a fulfilment of these requirements. For pit growth to be possible, three basic requirements must be fulfilled: (1) the environment must contain anions that can form an aggressive solution into the pit, (2) there must be a potential difference between the interior of the pit and the open surface outside the pit, (3) the temperature must exceed a critical value. The main factors that normally influence the possibility of pitting are the chloride content and the oxidising power of the environment, presence of anions other than chloride, temperature, possible presence of deposits on the steel surface, and the composition of the steel. Anions other than chloride in the bulk solution, including sulphate, usually have an inhibiting effect. Thiosulphate, however, is known to promote pitting under certain conditions. The possible ways of microbial activity to enhance pitting could include deposit formation leading to crevice type of attack, local modification of the composition of the environment to a more concentrated one, raising the electrode potential of the steel surface (''ennoblement''), or formation of reaction products that permit active dissolution inside a pit at lower potentials. Special attention is drawn to the possible action of thiosulphate by enhancing the anodic reaction at low potentials of the dissolving surface inside the pits. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  3. Pit formation on poly(methyl methacrylate) due to ablation induced by individual slow highly charged ion impact

    Science.gov (United States)

    Ritter, R.; Wilhelm, R. A.; Ginzel, R.; Kowarik, G.; Heller, R.; El-Said, A. S.; Papaléo, R. M.; Rupp, W.; Crespo López-Urrutia, J. R.; Ullrich, J.; Facsko, S.; Aumayr, F.

    2012-01-01

    We report the formation of nano-sized pits on poly(methyl methacrylate) after exposure to slow highly charged ion beams. The pits are formed on the polymer surface as a direct result of individual ion impacts. Intermittent contact mode atomic-force microscopy was employed to study the size evolution of the pits in dependence of potential and kinetic energies of the incident ions. A potential energy threshold value of approximately 7 keV was found for pit formation. Above this value an increase in potential energy results in an increasing pit volume, while the pit shape can be tuned by varying the kinetic energy.

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

    International Nuclear Information System (INIS)

    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 m3 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 m3 of old solid radwaste with competitive costs and in complete safety and protection of the environment. (author)

  5. Development of simple evaluation tool for water temperature and water level of spent fuel pit. Pit Calculator

    International Nuclear Information System (INIS)

    Before the accident at the Fukushima Daiichi Nuclear Power Station, we had already started to develop a method to predict the water temperature increase in the Spent Fuel Pit (SFP) adequately and simply during the shutdown of cooling systems. In these serial studies, we have carried out prediction of decay heat, calculation of evaporation heat flux from the water surface to the air and three dimensional (3D) thermal hydraulic computations of the SFP water using the computational fluid dynamics (CFD) software. After the accident, we extended the method capability to predict the water level decrease in the SFP during loss of all AC power supplies. 3D computations require a long computing time and its computed results showed that water temperatures were almost uniform outside the rack. This result indicated that a prediction system using one region (1R) calculation model might be able to obtain an average water temperature accurately. From these results, we had developed a simple evaluation tool for water temperature and water level of SFP named 'Pit Calculator'. (author)

  6. World War II, The CANOL project and the Marwell Tar Pit: a case study

    International Nuclear Information System (INIS)

    The CANOL project was a joint U.S.-Canada undertaking during World War II. It entailed the construction of a road and pipeline from the oil fields of Norman Wells on the Mackenzie River, 960 kms over the Mackenzie Mountains to a new refinery at Whitehorse. The goal was to provide a secure supply of aviation fuel far from the menace of Japanese bombers. Initially, the pipeline was expected to operate by October 1942. In actual fact, the first gasoline was not produced in the crude distillation unit until April 24, 1944, and it was not until November 1944 that the refinery finally began producing aviation fuel. Four months later, the pipeline and the refinery were shut down. The project cost American taxpayers $ 134 million. A total of 2650 kms of pipeline was laid. During the first nine months of pipeline operation 46,000 barrels of oil was spilled, much of it directly into the Mackenzie River. Total production from the refinery, which itself cost $ 27 million, wa 866,670 barrels of products. When the refinery was shut down, most of the refinery structures were dismantled and moved, via the Alaska Highway, to the newly discovered Leduc oilfields, but buildings, tanks and hydrocarbon waste were left behind. In a 1960 report it was estimated that some four million litres of oil has been pumped into a pit located within the containment berm formerly surrounding an 80,000 barrel oil storage tank which was dismantled after the shutdown. The bureaucratic dispute about who is responsible for cleaning up has been an issue ever since. The cost of cleanup was estimated at about $ 4 million in 1994. Since the federal government, the original owners of the land , transferred the land to provincial jurisdiction in 1970, it disclaimed any responsibility for site cleanup, however, there has been some recent evidence of willingness on the part of the Department of National Defence and the Department of Indian and Northern Affairs to determine proper actions to clean up the site

  7. Influence of the grain orientation spread on the pitting corrosion resistance of duplex stainless steels using electron backscatter diffraction and critical pitting temperature test at the microscale

    International Nuclear Information System (INIS)

    Highlights: ► Influence of grain orientation spread on the corrosion behavior of duplex stainless steels. ► Metallurgical criterion for pit initiation of duplex stainless steels. ► Crystallographic and electrochemical investigations at the microscale within both phases. - Abstract: The corrosion behavior of UNS S32202 duplex stainless steel was studied by combining electron backscatter diffraction (EBSD) measurements and critical pitting temperature tests at the microscale. The grain orientation spread (GOS) value was determined in grains of both phases from EBSD data. It was shown that austenitic sites containing extremely small ferrite grains having a GOS value greater than 1.3° were precursor sites for pitting in 4 M NaCl. The critical pitting temperature range was 45–90 °C. All the other sites of both phases remained passive up to 100 °C.

  8. The type III transporters (PiT-1 and PiT-2) are the major sodium-dependent phosphate transporters in the mice and human brains.

    Science.gov (United States)

    Inden, Masatoshi; Iriyama, Masaki; Zennami, Miho; Sekine, Shin-Ichiro; Hara, Akira; Yamada, Mitsunori; Hozumi, Isao

    2016-04-15

    PiT-1/SLC20A1 and PiT-2/SLC20A2 are members of the mammalian type-III inorganic phosphate (Pi) transporters encoded by the SLC20 genes. The broad distribution of SLC20A1 and SLC20A2 mRNAs in mammalian tissues is compatible with housekeeping maintenace of intracellular Pi homeostasis by transporting Pi from intrastitial fluid for normal cellular functions. Recently, mutations of SLC20A2 have been found in patients with idiopathic basal ganglia calcification (IBGC), also known as Fahr's disease. However, the localization of PiT-1 and PiT-2 in the normal brain has not been clarified yet. The aim of this study was to reveal the distribution of PiT-1 and PiT-2 in the mouse and human brains. As results, gene expressing analysis showed that SLC20A1 and SLC20A2 mRNAs were widely expressed throughout the mouse and human brains, although other Pi transporters encoded by SLC17 and SLC34 mRNAs were hardly detected. The region of cerebellum contained a higher level of SLC20A1 and SLC20A2 mRNAs than the other brain regions. Additionally, the cerebellum in the mouse brain contained higher levels of PiT-1 and PiT-2 than those in the other regions in the brain, respectively. The immonohistochemical studies showed that PiT-1 was recognized in neuron, astrocytes and vascular endothelial cells. Similarly to PiT-1 immunopositivity, PiT-2 was clearly recognized in these cells. These results suggest that SLC20 family plays a pivotal role in the maintenance of cellular Pi homeostasis particullary in the brain. The viewpoint is compatible with the finding that calcification in IBGC is recognized only in the brain. This provides us with a novel viewpoint to understand the basic pathophysiology of IBGC through type-III Pi transporters. PMID:26923164

  9. 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

  10. High Rate Laser Pitting Technique for Solar Cell Texturing

    Energy Technology Data Exchange (ETDEWEB)

    Hans J. Herfurth; Henrikki Pantsar

    2013-01-10

    High rate laser pitting technique for solar cell texturing Efficiency of crystalline silicon solar cells can be improved by creating a texture on the surface to increase optical absorption. Different techniques have been developed for texturing, with the current state-of-the-art (SOA) being wet chemical etching. The process has poor optical performance, produces surfaces that are difficult to passivate or contact and is relatively expensive due to the use of hazardous chemicals. This project shall develop an alternative process for texturing mc-Si using laser micromachining. It will have the following features compared to the current SOA texturing process: -Superior optical surfaces for reduced front-surface reflection and enhanced optical absorption in thin mc-Si substrates -Improved surface passivation -More easily integrated into advanced back-contact cell concepts -Reduced use of hazardous chemicals and waste treatment -Similar or lower cost The process is based on laser pitting. The objective is to develop and demonstrate a high rate laser pitting process which will exceed the rate of former laser texturing processes by a factor of ten. The laser and scanning technologies will be demonstrated on a laboratory scale, but will use inherently technologies that can easily be scaled to production rates. The drastic increase in process velocity is required for the process to be implemented as an in-line process in PV manufacturing. The project includes laser process development, development of advanced optical systems for beam manipulation and cell reflectivity and efficiency testing. An improvement of over 0.5% absolute in efficiency is anticipated after laser-based texturing. The surface textures will be characterized optically, and solar cells will be fabricated with the new laser texturing to ensure that the new process is compatible with high-efficiency cell processing. The result will be demonstration of a prototype process that is suitable for scale-up to a

  11. American Dream in Early American Literatuer

    Institute of Scientific and Technical Information of China (English)

    屈彩娥; 李小玺

    2008-01-01

    American dream has often been closely rehted to American literature.Many say that the American literary history can be seen as the history of American dreams.In most periods in history,writers,whose dreams have been infused in a variety of characters create the American literature.While in Early American literature,American dream had been presented in a dif-ferent way.

  12. HISTOLOGY OF SWEET ORANGE STEM PITTING CAUSED BY AN AUSTRALIAN ISOLATE OF CITRUS TRISTEZA VIRUS

    Science.gov (United States)

    Some strains of the citrus tristeza virus (CTV) cause stem pitting in sweet orange (Citrus sinensis (L.) Osbeck). This abnormality causes tree decline and reduction in fruit size and yield of affected citrus trees. Stem-pitting symptoms can occur on trunks, on all sizes of limbs, and on the twigs ...

  13. Cleanup Verification Package for the 126-F-1, 184-F Powerhouse Ash Pit

    Energy Technology Data Exchange (ETDEWEB)

    S. W. Clark and H. M Sulloway

    2007-10-31

    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.

  14. Preliminary study of realizability of Karazhyra open pit coal fines briquetting

    International Nuclear Information System (INIS)

    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)

  15. Decommissioning management of pit water at an uranium mine in Hunan Province

    International Nuclear Information System (INIS)

    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

  16. 7 CFR 52.802 - Grades of frozen red tart pitted cherries.

    Science.gov (United States)

    2010-01-01

    ... Product Description and Grades § 52.802 Grades of frozen red tart pitted cherries. (a) “U.S. Grade A” (or...) cherries per sample unit may be less than 9/16 inch (14 mm) in diameter, and that: (1) Possess a good red color; (2) Are practically free from pits; (3) Are practically free from defects; (4) Have a...

  17. Microsegregation-related pitting corrosion characteristics of AL-6XN superaustenitic stainless steel laser welds

    International Nuclear Information System (INIS)

    Research highlights: → Welding parameters affect pitting corrosion resistance of AL-6XN laser welds. → Lower heat input laser welds correspond to higher critical pitting temperature. → Depletion of Mo and Cr at dendrite cores causes preferential pitting corrosion. → Local Mo level at dendrite cores dominates weld pitting corrosion susceptibility. → Lower heat input laser welds manifest lower degree of microsegregation of Mo. - Abstract: Pitting corrosion resistance of laser welds of AL-6XN superaustenitic stainless steel (SASS) was investigated in acidic chloride ion medium. It was found that the critical pitting temperature (CPT) of the laser welds increased with increasing welding speed or decreasing laser power. Pitting attack preferentially occurred at selective dendrite cores of the laser welds. Analytical electron microscope (AEM) microanalysis revealed that depletion of Mo at dendrite cores due to microsegregation is the basic cause for the pitting corrosion susceptibility. The higher partition coefficient kMo and Mo concentration at dendrite cores of laser welds were attributed to the lower heat input welding parameters.

  18. Microsegregation-related pitting corrosion characteristics of AL-6XN superaustenitic stainless steel laser welds

    Energy Technology Data Exchange (ETDEWEB)

    Qian Ming, E-mail: qianm@simtech.a-star.edu.s [Department of Materials Science and Engineering, Lehigh University, Bethlehem, PA 18015 (United States); DuPont, J.N. [Department of Materials Science and Engineering, Lehigh University, Bethlehem, PA 18015 (United States)

    2010-10-15

    Research highlights: {yields} Welding parameters affect pitting corrosion resistance of AL-6XN laser welds. {yields} Lower heat input laser welds correspond to higher critical pitting temperature. {yields} Depletion of Mo and Cr at dendrite cores causes preferential pitting corrosion. {yields} Local Mo level at dendrite cores dominates weld pitting corrosion susceptibility. {yields} Lower heat input laser welds manifest lower degree of microsegregation of Mo. - Abstract: Pitting corrosion resistance of laser welds of AL-6XN superaustenitic stainless steel (SASS) was investigated in acidic chloride ion medium. It was found that the critical pitting temperature (CPT) of the laser welds increased with increasing welding speed or decreasing laser power. Pitting attack preferentially occurred at selective dendrite cores of the laser welds. Analytical electron microscope (AEM) microanalysis revealed that depletion of Mo at dendrite cores due to microsegregation is the basic cause for the pitting corrosion susceptibility. The higher partition coefficient k{sub Mo} and Mo concentration at dendrite cores of laser welds were attributed to the lower heat input welding parameters.

  19. Cleanup Verification Package for the 126-F-1, 184-F Powerhouse Ash Pit

    International Nuclear Information System (INIS)

    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

  20. Potential Multi-Canister Overpack (MCO) Cask Drop in the K West Basin South Loadout Pit

    International Nuclear Information System (INIS)

    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

  1. Pit to crack transition in stress corrosion cracking of a steam turbine disc steel

    Energy Technology Data Exchange (ETDEWEB)

    Turnbull, A.; Zhou, S. [National Physics Laboratory, Teddington (United Kingdom). Materials Centre

    2004-05-01

    Long term exposure tests have been carried out on a 3 NiCrMoV steam turbine disc steel in the form of cylindrical tensile test specimens self-loaded to 90% of {sigma}{sub 0.2} and exposed to three environmental conditions, viz. deaerated pure water, aerated pure water, and aerated water containing 1.5 ppm of chloride ion. Pitting occurred in all environments but the density and depth of pits in the chloride-containing medium was markedly greater. No cracking was observed in deaerated pure water but cracks initiated in aerated water between 13 and 19 months and in less than 7 months in aerated 1.5 ppm Cl{sup -} solution. The probability of a crack initiating from a pit of specific depth in aerated solution could be described well by a Weibull function. Profiling of pits and cracks in the disc steel tested in aerated 1.5 ppm Cl{sup -} solution showed that there while there were many cracks with a depth greater than that of the corresponding pit the depth of some cracks was smaller than that of the corresponding pit, suggesting that cracks do not necessarily initiate from the bottom of the pits. The growth rate of short cracks emerging from pits appeared greater than that of long cracks in fracture mechanics specimens. (author)

  2. Cleanup Verification Package for the 126-F-1, 184-F Powerhouse Ash Pit

    Energy Technology Data Exchange (ETDEWEB)

    S. W. Clark and H. M. Sulloway

    2007-09-26

    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.

  3. Investigation on Floating Lid Construction, pit Water Storage, Ottrupgaard, Denmark

    DEFF Research Database (Denmark)

    Heller, Alfred

    ambient conditions floating on hot water. The test lids were examined for tightness by a number of means. The results showed critical construction errors of the first lid design. A redesigned lid showed acceptable results, but also some water penetration into the lid insulation. The entered water gathers...... the development of lid constructions is crucial for the development of pit water storage and seasonal storage, as it seems that the development of solar collectors will not have a breakthrough in the near future.The Ottrupgaard lid design is basically a sandwich element construction of PUR......-foam between two metallic covers. The elements are joint in situ by special steel profiles. A two-step sealing with silicone mass and bitumen-tape is applied to tighten the construction.To ensure a proper lid design, two test lids of 1.5x1.5 metres were tested at the Department of Buildings and Energy under...

  4. Pitting damage in metals by mercury cavitation with MIMTM

    International Nuclear Information System (INIS)

    In the liquid mercury target for the spallation neutron source, pressure waves occurs owing to the high-intense proton beam bombardment. The pressure waves induces the cavitation in the interface between the mercury and the target vessel through the propagation process. Erosion damage composed of micro-pits clusters is formed by the micro-jets and shock waves emitted from cavitation bubble collapse. In this paper, researches for damage structure of the material that was examined using the electroMagnetic IMpact Testing Machine (MIMTM) form the viewpoint of high-speed deformation. The result showed that the 200 ∼ 300 m/s of collision velocity for micro-jet impacting which was estimated from the numerical simulation is reasonable value. (J.P.N.)

  5. Open-pit production and control at Roessing

    International Nuclear Information System (INIS)

    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

  6. 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......The need for continuous safety improvements and increased operational efficiency is driving the mining industry through a transition towards automated operations. From a communications perspective, this transition introduces a new set of high-bandwidth business- and mission-critical applications...... techniques. On the other hand, unlike unpredictable disaster scenarios, mining is a carefully planned activity. Taking advantage of this predictability element, we propose a framework that integrates mine and network planning so that continuous and automated adaptation of the network becomes possible...

  7. Investigation on Floating Lid Construction, pit Water Storage, Ottrupgaard, Denmark

    DEFF Research Database (Denmark)

    Heller, Alfred

    1997-01-01

    -foam between two metallic covers. The elements are joint in situ by special steel profiles. A two-step sealing with silicone mass and bitumen-tape is applied to tighten the construction.To ensure a proper lid design, two test lids of 1.5x1.5 metres were tested at the Department of Buildings and Energy under...... the development of lid constructions is crucial for the development of pit water storage and seasonal storage, as it seems that the development of solar collectors will not have a breakthrough in the near future.The Ottrupgaard lid design is basically a sandwich element construction of PUR...... ambient conditions floating on hot water. The test lids were examined for tightness by a number of means. The results showed critical construction errors of the first lid design. A redesigned lid showed acceptable results, but also some water penetration into the lid insulation. The entered water gathers...

  8. CMP [Chemicals, Metals, and Pesticides] Pits: Environmental information document

    International Nuclear Information System (INIS)

    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

  9. Cost analysis of open-pit mining by heap leaching

    International Nuclear Information System (INIS)

    The costs of producing uranium by an open-pit mining using a heap leaching beneficiation operation are analyzed. The selection of a heap leaching operation is dictated largely by the small size of the orebody. The uranium minerals present respond readily to the lixiviant employed permitting some 75 to 80 per cent of the 1200 to 1500 ppm of U3O8 present in the heap to be recovered. Manpower and transportation account for a large proportion of the operating costs. The capital investment employed is equivalent to $ 5 000 000 and the production cost is equivalent to a value in the range $ 10 to $ 15 per pound on U3O8. Of interest is the 11.5 per cent of the overhead costs spent on security

  10. Double contingency controls in the pit disassembly and conversion facility

    International Nuclear Information System (INIS)

    A Pit Disassembly and Conversion Facility (PDCF) will be built and operated at DOE'S Savannah River Site (SRS) in South Carolina. The facility will process over three metric tons of plutonium per year. There will be a significant amount of special nuclear material (SNM) moving through the various processing modules in the facility, and this will obviously require well-designed engineering controls to prevent criticality accidents. The PDCF control system will interlock glovebox entry doors closed if the correct amount of SNM has not been removed from the exit enclosure. These same engineering controls will also be used to verify that only plutonium goes to plutonium processing gloveboxes, enriched uranium goes to enriched uranium processing, and that neither goes into non-SNM processing gloveboxes.

  11. Flare pit waste remediation by low temperature oxidation

    International Nuclear Information System (INIS)

    A cost-effective method for treating contaminated soil 'in situ' using low temperature oxidation (LTO) to convert the hydrocarbons to inert coke, is discussed. Low temperature oxidation of a wide variety of hydrocarbons in the presence of core material and water has been investigated previously using plug flow reactors. For Athabasca bitumen, it was found that more than 80 per cent of the initial oil was converted into coke after only a few hours of injecting oxygen/nitrogen mixtures with less than 10 per cent oxygen content at temperatures ranging from 150 degrees C to 275 degrees C. Increasing the oxygen content in the gas and increasing reaction time would, presumably further augment the conversion of hydrocarbons to coke. The method is particularly well suited for remediating flare pits. 5 refs., 7 figs

  12. Environmental evaluation of produced water disposal to surface pits

    International Nuclear Information System (INIS)

    A study was conducted to examine the impacts of using groundwater from shallow aquifers for injection into oil reservoirs for maintenance of formation pressures. The study also examined the impacts of disposing the produced water to surface infiltration pits. Records of historical and current extraction and disposal volumes over the life of an oil field were obtained to evaluate the environmental impacts. The historical data was supplemented by a drilling and sampling program. Hydrodynamic parameters were measured while groundwater samples were collected for analysis of inorganic and organic indicators. Results showed that the main migration route for the produced water was downward through the water table and then horizontal to extraction wells. For environmental purposes, it was recommended that the deep well injection method should be used for produced water in order to remediate the hydrocarbon impacted groundwater

  13. Management of Pit 9 - highlights of accomplishments and lessons learned to date

    International Nuclear Information System (INIS)

    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 ft3 of soil beneath and between the buried waste and about 250,000 ft3 of overburden soil. The average depth of the pit from soil surface to bedrock is approximately 17.5 feet. Approximately 110,000 ft3 of transuranic (TRU) contaminated mixed wastes from Rocky Flats and approximately 40,000 ft3 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

  14. Effects of bicarbonate and sulfate ions on the pitting corrosion behavior of copper

    International Nuclear Information System (INIS)

    The strategy for disposal of high-level radioactive waste in China is to enclose the spent nuclear fuel in sealed metal canisters which are embedded in bentonite clay hundreds meters down in the bed-rock. The choice of container material depends largely on the redox conditions and the aqueous environment of the repository. One of the choices for the fabrication of waste canisters is copper, because it is thermodynamically stable under the saline, anoxic conditions over the large majority of the container lifetime. However, in the early aerobic phase of the geological disposal the corrosion of copper could take place, and the corrosion behavior of copper would be influenced by the complex chemical conditions of groundwater markedly. Pitting corrosion of copper often take place in power plants or air-conditioning condensate water. The corrosion environment usually contains bicarbonate, sulfate and chloride ions. In the early stage of geological disposal, if the aerobic water with bicarbonate, sulfate and chloride ions immersion repository, the pitting corrosion of copper may occur. The content of bicarbonate and sulfate ion in the water chemistry environment, as well as the synergy between them, could affect the behavior of pitting seriously. The content of bicarbonate and chloride ion in the water chemistry environment, as well as the synergy between them, could affect the behavior of pitting seriously. The researchers generally agreed that chloride ions would promote the occurrence of pitting corrosion of copper, and bicarbonate ions will lead to surface passivation and inhibition of pitting. However, there is no systematic work in this area. In our work, the cycle polarization behavior and surface morphology of pitting has been investigated in HCO3- and Cl- mixed solution, respectively by electrochemical cyclic polarization test and scanning electron microscopy. The results show that the circular polarization curves of copper could be divided into four types. The

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

    Institute of Scientific and Technical Information of China (English)

    SHUAI Li; JIANG Ming; DUAN Delin

    2006-01-01

    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.

  16. Cavitation pitting and erosion of aluminum 6061-T6 in mineral oil water

    Science.gov (United States)

    Rao, B. C. S.; Buckley, D. H.

    1983-01-01

    Cavitation erosion studies of aluminum 6061-T6 in mineral oil and in ordinary tap water are presented. The maximum erosion rate (MDPR, or mean depth of penetration rate) in mineral oil was about four times that in water. The MDPR in mineral oil decreased continuously with time, but the MDPR in water remained approximately constant. The cavitation pits in mineral oil were of smaller diameter and depth than the pits in water. Treating the pits as spherical segments, we computed the radius r of the sphere. The logarithm of h/a, where h is the pit depth and 2a is the top width of the pit, was linear when plotted against the logarithm of 2r/h - 1.

  17. Effect of Trace Sn on Pitting Behaviors of High Voltage Anode Aluminum Foil

    Institute of Scientific and Technical Information of China (English)

    Jingbo SONG; Weimin MAO; Hong YANG; Huiping FENG

    2008-01-01

    The effect of trace Sn on the pitting morphology of high voltage anode aluminum foils was investigated. The distributions of microelement Sn, Fe, Si, Cu and Mg in the surface layer of aluminum foils with different Sn content were determined by using a secondary ion mass spectrometer. It was found that the micro-alloyed Sn is enriched at the external surface. The mechanism of pitting behavior of trace Sn on aluminum surface is similar with that of lead. Enrichment of Sn in the surface layer provides large numbers of sites for initiation of pitting corrosion, while pitting sites appeared relatively inhomogenously in the foils without Sn. Sn, as an eco-friendly microelement, can be applied to replace Pb in improving the homogenous pitting behaviors of high voltage aluminum foils, in which the volume fraction of cube texture is not reduced.

  18. Non Destructive Testing Measurement for Monitoring Pitting Corrosion using Dcp Techniques

    International Nuclear Information System (INIS)

    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

  19. 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.

  20. EVALUATION OF THE PROBABILITY DISTRIBUTION OF PITTING CORROSION FATIGUE LIFE IN AIRCRAFT MATERIALS

    Institute of Scientific and Technical Information of China (English)

    WANG Qingyuan (王清远); N.KAWAGOISHI; Q.CHEN; R.M.PIDAPARTI

    2003-01-01

    Corrosion and fatigue properties of aircraft materials are known to have a considerable scatter due to the random nature of materials,loading,and environmental conditions.A probabilistic approach for predicting the pitting corrosion fatigue life has been investigated which captures the effect of the interaction of the cyclic load and corrosive environment and all stages of the corrosion fatigue process (i.e.the pit nucleation and growth,pit-crack transition,short- and long-crack propagation).The probabilistic model investigated considers the uncertainties in the initial pit size,corrosion pitting current,and material properties due to the scatter found in the experimental data.Monte Carlo simulations were performed to define the failure probability distribution.Predicted cumulative distribution functions of fatigue life agreed reasonably well with the existing experimental data.

  1. The Effect of Calcium Treatment on Pitting Corrosion of Type 316L Austenitic Stainless steel

    International Nuclear Information System (INIS)

    Pitting in chloride containing aqueous solution occurs mainly on manganese sulphide. Adding a slight amount of Ca as an alloying element prevents the MnS formation, since Ca is a stronger sulphide former than Mn. In this work, calcium treated Type 316L austenitic stainless steels have been investigated electrochemically to evaluate the effect of modified inclusions on pitting corrosion. Staircase polarization measurements were performed in 3.5% NaCl solution, where the occurrence of pits in materials caused current spikes. During staircase polarization test, steels with calcium treatment show low and discontinuous current spikes while those without calcium treatment show high and continuous current spikes. The results show that calcium treatment in Ca/S ratio of 1 ∼ 2 leads to an increase in the pitting potential of several hundred mV. A relationship between the calcium treatment and pit initiation sites was described

  2. 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.

  3. Gas cylinder disposal pit remediation waste minimization and management

    International Nuclear Information System (INIS)

    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

  4. Terrace pit mining systems, Phase I, Task I

    Energy Technology Data Exchange (ETDEWEB)

    1979-12-07

    This report presents an abstract-index of the agencies, legislation and regulations, in that order, that affect the design and operation of a surface/terrace pit mine on both state and federal levels. It is divided into two sections: The Federal Program and The State Programs. The Federal Program comprises two subsections, the first categorized by the federal administrative agencies and commissions whose jurisdiction encompasses physical mine make-up and worker well being. The second subsection is categorized by environmental performance legislation. This is a cross referenced approach which aids in deciphering the federal program's complex structure. The overlapping authority and duplication of effort that is inherent in federal regulation of a complex industry is illustrated. The State Programs consists of a table of state laws by primary areas of regulation, a summary table of the lead state agencies for the 13 states considered, and an abstract of their designated authority; and finally, a synopsis of the approach used by each state to comply with the environmental performance and occupational safety standards established by the federal government for maintaining air, water and land quality and a safe environment for the worker. The various state agencies which typically have jurisdictional responsibilities for surface mining activities are illustrated. Once the specific terrace pit mining site has been selected, requirements of local government agencies will be identified, analyzed and included in the master list of permit and regulation requirements. The finalized list will be used to develop the most time effective sequence for submitting permit applications to federal, state and local agencies.

  5. Radon release and dispersion from an open pit uranium mine

    Energy Technology Data Exchange (ETDEWEB)

    Kisieleski, W.E.

    1980-06-01

    Radon-222 flux from representative sections of the United Nuclear St. Anthony open-pit mine complex was measured. The collected radon was adsorbed on activated charcoal and the radon activity was measured by gamma spectroscopy. System design, calibration, and the procedure to determine radon flux density (pCi/m/sup 2/.s) are described. A continuous series of radon flux densities were measured over a 5-month period at a control point in the mine. The average flux density at the control point was 1.9 pCi/m/sup 2/.s. A close correlation between radon flux density variations and changes in barometric pressure was observed by a comparison of meteorological data and average daily radon flux density measured at the control point. The release rate from each section of the mine was calculated from the average radon flux density and the area of the section, as determined from enlarged aerial photographs. The average radon flux density for eight locations over the ore-bearing section was 7.3 pCi/m/sup 2/.s. The average flux density for four locations over undisturbed topsoil was 0.17 pCi/m/sup 2/.s. The average Ra-226 content of ten samples taken from the ore-bearing region was 102 pCi/g ore. The ratio of radon flux density to radium content (specific flux) was 0.072. The release rate from the entire St. Anthony open pit was determined to be 3.5 x 10/sup 5/ pCi/s. This rate is comparable to the natural release of radon from one square mile of undisturbed topsoil. 16 refs., 31 figs., 11 tabs.

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

    International Nuclear Information System (INIS)

    The quantity of 222Rn (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 226Ra (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

  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. 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.

  9. Effect of heat treatment on pitting corrosion of austenitic Cr-Ni-Mo steels in sodium chloride solution

    International Nuclear Information System (INIS)

    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 7500C 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)

  10. Central Shops Burning/Rubble Pit 631-6G Additional Sampling and Monitor Well Installation Report

    International Nuclear Information System (INIS)

    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. American Culture Reflected in American English

    Institute of Scientific and Technical Information of China (English)

    李华芳

    2013-01-01

    Language is a vehicle for culture. It is also a key component of culture. It not only reflects culture but also influences culture. As a variety of British English, American English, especially American words and expressions can reflect American culture from many aspects. This paper studies some typical traits of American culture reflected in words and expressions of American Eng-lish.

  12. Detection of Trichomonas vaginalis DNA by use of self-obtained vaginal swabs with the BD ProbeTec Qx assay on the BD Viper system.

    Science.gov (United States)

    Van Der Pol, Barbara; Williams, James A; Taylor, Stephanie N; Cammarata, Catherine L; Rivers, Charles A; Body, Barbara A; Nye, Melinda; Fuller, Deanna; Schwebke, Jane R; Barnes, Mathilda; Gaydos, Charlotte A

    2014-03-01

    Trichomonas vaginalis is the most prevalent nonviral sexually transmitted infection worldwide, and improved diagnostic methods are critical for controlling this pathogen. Diagnostic assays that can be used in conjunction with routine chlamydia/gonorrhea nucleic acid-based screening are likely to have the most impact on disease control. Here we describe the performance of the new BD T. vaginalis Qx (TVQ) amplified DNA assay, which can be performed on the automated BD Viper system. We focus on data from vaginal swab samples, since this is the specimen type routinely used for traditional trichomonas testing and the recommended specimen type for chlamydia/gonorrhea screening. Vaginal swabs were obtained from women attending sexually transmitted disease or family planning clinics at 7 sites. Patient-collected vaginal swabs were tested by the TVQ assay, and the Aptima T. vaginalis (ATV) assay was performed using clinician-collected vaginal swabs. Additional clinician-collected vaginal swabs were used for the wet mount and culture methods. Analyses included comparisons versus the patient infection status (PIS) defined by positive results with the wet mount method or culture, direct comparisons assessed with κ scores, and latent class analysis (LCA) as an unbiased estimator of test accuracy. Data from 838 women, 116 of whom were infected with T. vaginalis, were analyzed. The TVQ assay sensitivity and specificity estimates based on the PIS were 98.3% and 99.0%, respectively. The TVQ assay was similar to the ATV assay (κ=0.938) in direct analysis. LCA estimated the TVQ sensitivity and specificity as 98.3 and 99.6%, respectively. The TVQ assay performed well using self-collected vaginal swabs, the optimal sample type, as recommended by the CDC for chlamydia/gonorrhea screening among women. PMID:24391200

  13. Venom lethality and diet: differential responses of natural prey and model organisms to the venom of the saw-scaled vipers (Echis).

    Science.gov (United States)

    Richards, D P; Barlow, A; Wüster, W

    2012-01-01

    The composition of snake venoms shows a high degree of variation at all taxonomic levels, and natural selection for diet has been implicated as a potential cause. Saw-scaled vipers (Echis) provide a good model for studying this phenomenon. The venoms of arthropod feeding species of Echis are significantly more toxic to natural scorpion prey than those of species which feed predominantly upon vertebrate prey. Although testing venom activity on natural prey is important for our understanding of the evolution of venom, natural prey species are often difficult to obtain in sufficient numbers for toxinological work. In order to test the viability of using cheaper and more easily available model organisms for toxicity assessments in evolutionary research, and the extent to which toxicity of arthropod-eating Echis venoms is increased to arthropods in general or targeted to certain groups, we conducted median lethal dosage (LD(50)) and time to death trials using the desert locust (Schistocerca gregaria) as a model arthropod, rarely consumed by wild Echis. The venoms of arthropod specialist Echis were found to be significantly more toxic to locusts than the venom of a vertebrate feeding outgroup (Bitis arietans), and one arthropod specialist venom was found to be more toxic than those species which feed upon arthropods infrequently or not at all. The venoms of arthropod specialists were also found to cause death and incapacitation faster than the vertebrate feeding outgroup. Despite some similarity of trends, there are considerable differences between the response of natural prey (scorpions) and a model arthropod (locust) to the venoms of Echis species. This suggests that when possible, natural prey rather than convenient model organisms should be used to gain an understanding of the functional significance of variation in venom composition in snakes. PMID:22079297

  14. American Houses

    Institute of Scientific and Technical Information of China (English)

    张梦华

    2004-01-01

    American houses usually have private kitchens,a living room and sometimes separate areas for eating and watching television,A house usually has its own mailbox,a yard with plants or perhaps a lawn,and a place to store garbage out of sight.

  15. Phylogeny and diversification of mountain vipers (Montivipera, Nilson et al., 2001) triggered by multiple Plio-Pleistocene refugia and high-mountain topography in the Near and Middle East.

    Science.gov (United States)

    Stümpel, Nikolaus; Rajabizadeh, Mehdi; Avcı, Aziz; Wüster, Wolfgang; Joger, Ulrich

    2016-08-01

    The Near and Middle East is a hotspot of biodiversity, but the region remains underexplored at the level of genetic biodiversity. Here, we present an extensive molecular phylogeny of the viperid snake genus Montivipera, including all known taxa. Based on nuclear and mitochondrial data, we present novel insights into the phylogeny of the genus and review the status of its constituent species. Maximum likelihood methods revealed a montane origin of Montivipera at 12.3Mya. We then analyzed factors of mountain viper diversity. Our data support substantial changes in effective population size through Plio-Pleistocene periods. We conclude that climatic oscillations were drivers of allopatric speciation, and that mountain systems of the Near and Middle East have strongly influenced the evolution and survival of taxa, because climatic and topographical heterogeneities induced by mountains have played a crucial role as filters for dispersal and as multiple refugia. The wide diversity of montane microhabitats enabled mountain vipers to retain their ecological niche during climatic pessima. In consequence the varied geological and topographical conditions between refugia favoured genetic isolation and created patterns of species richness resulting in the formation of neoendemic taxa. Our data support high concordance between geographic distributions of Montivipera haplotypes with putative plant refugia. PMID:27165940

  16. The VIMOS Public Extragalactic Redshift Survey (VIPERS). Exploring the dependence of the three-point correlation function on stellar mass and luminosity at 0.5

    CERN Document Server

    Moresco, M; Moscardini, L; Branchini, E; Cappi, A; Davidzon, I; Granett, B R; de la Torre, S; Guzzo, L; Abbas, U; Adami, C; Arnouts, S; Bel, J; Bolzonella, M; Bottini, D; Coupon, J; Cucciati, O; De Lucia, G; Franzetti, P; Fritz, A; Fumana, M; Garilli, B; Ilbert, O; Iovino, A; Krywult, J; Brun, V Le; Fèvre, O Le; Małek, K; McCracken, H J; Polletta, M; Pollo, A; Scodeggio, M; Tasca, L A M; Tojeiro, R; Vergani, D; Zanichelli, A

    2016-01-01

    The three-point correlation function (3PCF) is a powerful probe to investigate the clustering of matter in the Universe in a complementary way with respect to lower-order statistics, providing additional information with respect to two-point correlation function and allowing to shed light on biasing, nonlinear processes and deviations from Gaussian statistics. In this paper, we analyse the first data release of the VIMOS Public Extragalactic Redshift Survey (VIPERS), determining the dependence of the three-point correlation function on luminosity and stellar mass at $z=[0.5,1.1]$. We exploit the VIPERS Public Data Release 1, consisting of more than 50000 galaxies with B-band magnitudes in the range $-21.6\\lesssim M_{\\rm B}-5\\log(h)\\lesssim-19.9$ and stellar masses in the range $9.8\\lesssim\\log(M_\\star[h^{-2}\\,M_\\odot])\\lesssim 10.7$. We measure both the connected 3PCF and the reduced 3PCF in redshift space, probing different configurations and scales, in the range $2.5

  17. Application of spectral analysis of the electrochemical noise to the investigation of aluminium alloy pitting corrosion

    International Nuclear Information System (INIS)

    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

  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. The role of V-shaped pits in (AlGaIn)N LED structures

    International Nuclear Information System (INIS)

    Despite the high density of threading dislocations generally found in group-III-nitride semiconductors, the light emission efficiency of GaInN/GaN quantum well (QW) structures is exceptionally high at room temperature. Therefore, nonradiative recombination processes of charge carriers in a QW must be suppressed. This can be explained by our V-shaped pit model, where every threading dislocation is decorated with a hexagonal V-shaped pit. The QWs inside a V-shaped pit are thinner compared with the QWs on c-plane. Thus the effective band gap is significant larger and the charge carriers will be kept away from the threading dislocations. In our GaInN/GaN QW structures with high internal quantum efficiency we find in TEM well-controlled V-shaped pits around the dislocations. In order to clarify the situation for commercial devices we investigated blue and green LEDs from various suppliers. We find that V-shaped pits are decorating virtually all threading dislocations in the QW region. This indicates that suppression of nonradiative recombination by V-shaped pits may be a desirable mechanism for achieving high light emission efficiency. We also discuss the effect of pits in GaN/AlGaN QW structures, where the typical emission efficiency is much lower than for GaInN/GaN structures

  20. Linking irradiance-induced changes in pit membrane ultrastructure with xylem vulnerability to cavitation.

    Science.gov (United States)

    Plavcová, Lenka; Hacke, Uwe G; Sperry, John S

    2011-03-01

    The effect of shading on xylem hydraulic traits and xylem anatomy was studied in hybrid poplar (Populus trichocarpa x deltoides, clone H11-11). Hydraulic measurements conducted on stem segments of 3-month-old saplings grown in shaded (SH) or control light (C) conditions indicated that shading resulted in more vulnerable and less efficient xylem. Air is thought to enter vessels through pores in inter-vessel pit membranes, thereby nucleating cavitation. Therefore, we tested if the ultrastructure and/or chemistry of pit membranes differed in SH and C plants. Transmission electron micrographs revealed that pit membranes were thinner in SH, which was paralleled by lower compound middle lamella thickness. Immunolabelling with JIM5 and JIM7 monoclonal antibodies surprisingly indicated that pectic homogalacturonans were not present in the mature pit membrane regardless of the light treatment. Porosity measurements conducted with scanning electron microscopy were significantly affected by the method used for sample dehydration. Drying through a gradual ethanol series seems to be a better alternative to drying directly from a hydrated state for pit membrane observations in poplar. Scanning electron microscopy based estimates of pit membrane porosity probably overestimated real porosity as suggested by the results from the 'rare pit' model. PMID:21118422

  1. A practical method for determining pit depths using X-ray attenuation in EDX spectra

    International Nuclear Information System (INIS)

    Highlights: • A practical method is developed for the rapid determination of pit depth from X-ray microanalysis. • The method relies on attenuation of X rays passing through pit walls on the way to the X-ray detector. • The method is valuable for deep, narrow pits, which are inaccessible to the standard techniques. - Abstract: A practical method has been developed for rapidly determining the depth of a corrosion micro-pit from the path lengths of X rays passing through the walls of the pit on their way to an X-ray detector. The method takes advantage of the attenuation of the Bremsstrahlung and characteristic X-ray radiation accompanying each X-ray spectrum, and the results are verified independently using AFM and the special pit geometry surrounding MnS inclusions in 1018 carbon steel. The method has general validity and is especially valuable in those cases where the pit depth-to-width ratio is too steep to measure using the conventional methods

  2. 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.

  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. American Headache Society

    Science.gov (United States)

    ... Us American Migraine Foundation Login THE AMERICAN Headache Society is a professional society of health care providers dedicated to the study ... MIGRAINE MOMENT” FILM CONTEST WINNERS The American Headache Society and American Migraine Foundation, the AHS’s charitable division, ...

  5. Cancer and African Americans

    Science.gov (United States)

    ... Population Profiles > Black/African American > Cancer Cancer and African Americans African Americans have the highest mortality rate ... 65MB] At a glance – Top Cancer Sites for African Americans (2008-2012) Cancer Incidence Rates per 100, ...

  6. American Sign Language

    Science.gov (United States)

    ... Health Info » Voice, Speech, and Language American Sign Language On this page: What is American Sign Language? ... signs "I love you." What is American Sign Language? American Sign Language (ASL) is a complete, complex ...

  7. 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. PMID:21654342

  8. Atypical pit craters on Mars: New insights from THEMIS, CTX, and HiRISE observations

    Science.gov (United States)

    Cushing, Glen E.; Okubo, Chris H.; Titus, Timothy N.

    2015-06-01

    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 High Resolution Imaging Science Experiment (HiRISE) and Context Camera to refine previous work where seven APCs were described from lower resolution THEMIS visible wavelength 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.

  9. 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).

  10. 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)

    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 137Cs; (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. Optimal Growth Conditions for Selective Ge Islands Positioning on Pit-Patterned Si(001

    Directory of Open Access Journals (Sweden)

    Bergamaschini R

    2010-01-01

    Full Text Available Abstract We investigate ordered nucleation of Ge islands on pit-patterned Si(001 using an original hybrid Kinetic Monte Carlo model. The method allows us to explore long time-scale evolution while using large simulation cells. We analyze the possibility to achieve selective nucleation and island homogeneity as a function of the various parameters (flux, temperature, pit period able to influence the growth process. The presence of an optimal condition where the atomic diffusivity is sufficient to guarantee nucleation only within pits, but not so large to induce significant Ostwald ripening, is clearly demonstrated.

  12. Chronology and spatial distribution of large mammal bones in PIT 91, Rancho La Brea

    OpenAIRE

    Friscia, Anthony R.; Van Valkenburgh, Blaire; Spencer, Lillian; Harris, John

    2008-01-01

    The Rancho La Brea tar pits represent a collection of Pleistocene fossils from an unusual sedimentary environment. A taphonomic analysis of a single tar seep, Pit 91, reveals a complex history of deposition and diagenesis for specimens found there. Radiometric dating of 46 bones from Pit 91 documents at least two episodes of deposition, one from 45,000 to 35,000 yr and another, shorter interval from 26,500 to 23,000 yr. Interestingly, the law of superposition was not upheld consistently in th...

  13. Quantitative evaluation of erosive cavitation pressure field from pits in material: fact or myth?

    Science.gov (United States)

    Choi, J.-K.; Chahine, G. L.

    2015-12-01

    Material pitting in a cavitating flow has been used for a long time as an indicator of the vague ‘cavitation intensity’ concept. Periodically, some researchers suggest pitting tests as a “simple” means to provide quantitative measurements of the amplitude of the impulsive pressures in the cavitation field, especially when combined with Tabor's formula or with simple finite element computations with static loads. This paper examines the viability of such a method using fully coupled bubble dynamics and material response, and strongly concludes that the commonly accepted idea is a myth, as different loading scenarios with the same amplitude of the cavitation impulsive pressure result in different pit aspect ratios.

  14. Microstructure and pitting corrosion of 13CrNiMo weld metals

    Energy Technology Data Exchange (ETDEWEB)

    Bilmes, P.D. [Laboratorio de Investigaciones de Metalurgia Fisica ' Ing. Gregorio Cusminsky' (LIMF), Departamento Mecanica, Facultad de Ingenieria, Universidad Nacional de la Plata, calle 1 y 47, 1900 La Plata (Argentina); Llorente, C.L. [Laboratorio de Investigaciones de Metalurgia Fisica ' Ing. Gregorio Cusminsky' (LIMF), Departamento Mecanica, Facultad de Ingenieria, Universidad Nacional de la Plata, calle 1 y 47, 1900 La Plata (Argentina); Saire Huaman, L. [Instituto de Investigaciones, Fisicoquimicas Teoricas y Aplicadas (INIFTA), Facultad de Ciencias Exactas, Universidad Nacional de la Plata, Sucursal 4-C.C. 16, 1900 La Plata (Argentina); Laboratorio de Ingenieria de Corrosion y Tecnologia Electroquimica (LICTE), Departamento Ingenieria Quimica, Facultad de Ingenieria, Universidad Nacional de la Plata, 1 y 47, 1900 La Plata (Argentina); Gassa, L.M. [Instituto de Investigaciones, Fisicoquimicas Teoricas y Aplicadas (INIFTA), Facultad de Ciencias Exactas, Universidad Nacional de la Plata, Sucursal 4-C.C. 16, 1900 La Plata (Argentina); Laboratorio de Ingenieria de Corrosion y Tecnologia Electroquimica (LICTE), Departamento Ingenieria Quimica, Facultad de Ingenieria, Universidad Nacional de la Plata, 1 y 47, 1900 La Plata (Argentina); Gervasi, C.A. [Instituto de Investigaciones, Fisicoquimicas Teoricas y Aplicadas (INIFTA), Facultad de Ciencias Exactas, Universidad Nacional de la Plata, Sucursal 4-C.C. 16, 1900 La Plata (Argentina) and Laboratorio de Ingenieria de Corrosion y Tecnologia Electroquimica (LICTE), Departamento Ingenieria Quimica, Facultad de Ingenieria, Universidad Nacional de la Plata, 1 y 47, 1900 La Plata (Argentina)]. E-mail: gervasi@inifta.unlp.edu.ar

    2006-10-15

    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.

  15. Microstructure and pitting corrosion of 13CrNiMo weld metals

    International Nuclear Information System (INIS)

    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

  16. The quality evaluation program for plutonium pits at the U.S. DOE Pantex plant.

    Science.gov (United States)

    Vickers, L; Eifert, E

    2000-11-01

    The United States Department of Energy Pantex Plant quality evaluation program for plutonium pits is an extensive program that includes 1) weigh and leak check system; 2) radiography; and 3) dye penetrant testing. Successful completion of these diagnostics qualifies a pit to remain in the active status stockpile program. The use of lead aprons and a robot when handling the plutonium pits minimizes personnel exposures to ionizing radiation. All personnel exposures to ionizing radiation at Pantex Plant are As Low As Reasonably Achievable. PMID:11045519

  17. Effect of chloride concentration and pH on pitting corrosion of waste package container materials

    International Nuclear Information System (INIS)

    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. Coat proteins isolated from clathrin coated vesicles can assemble into coated pits

    OpenAIRE

    1989-01-01

    Isolated human fibroblast plasma membranes that were attached by their extracellular surface to a solid substratum contained numerous clathrin coated pits that could be removed with a high pH buffer (Moore, M.S., D.T. Mahaffey, F.M. Brodsky, and R.G.W. Anderson. 1987. Science [Wash. DC]. 236:558-563). When these membranes were incubated with coat proteins extracted from purified bovine coated vesicles, new coated pits formed that were indistinguishable from native coated pits. Assembly was de...

  19. 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%.

  20. Phenotypic and genetic variation in two North American arctic charr (Salvelinus alpinus) stocks cultured in recirculating aquaculture systems

    Science.gov (United States)

    Arctic charr were obtained as eggs from two North American sources, an eastern (Fraser River, Canada) and a western (Bristol Bay, Alaska) stock. Fish from each family (n=38) were pit tagged at approximately 12 months post-hatch (eastern mean+SE=247+/-13g, western mean+SE=220+/-g) and stocked commun...

  1. KW basin backwash pit sludge measurement/video

    International Nuclear Information System (INIS)

    The purpose of this procedure is to gather visual and depth information and monitor underwater activities in the 105-KW SFBWP and transfer channel. Profile lighting (the use of lighting and shadows to show the surface contour) will be used to assess the contour of the sludge surface. Select measurements will also be taken to determine the actual sludge depth. The control/video station will be setup outside the radiation area or in lowest possible exposure area to reduce personnel exposure (ALARA). This procedure is to provide a mechanism to assist in fully characterizing the volume and surface topology of the sludge currently deposited in the sandfilter backwash pit (SFBWP). Surveillance Systems Engineering (SSE) personnel will gather visual information utilizing a closed circuit television (CCTV) color camera, mounted to stainless steel extension poles. Connections allow the camera to be connected with a pan and tilt to allow better positioning capabilities and to get good landscape profiling of the sediment surface. The information will be videotaped to a one-half inch NTSC or Y/C format. Underwater lighting will be accomplished by means of 500 watt underwater lamps

  2. KW basin backwash pit sludge measurement/video

    Energy Technology Data Exchange (ETDEWEB)

    Dodd, E.N. Jr.

    1994-09-06

    The purpose of this procedure is to gather visual and depth information and monitor underwater activities in the 105-KW SFBWP and transfer channel. Profile lighting (the use of lighting and shadows to show the surface contour) will be used to assess the contour of the sludge surface. Select measurements will also be taken to determine the actual sludge depth. The control/video station will be setup outside the radiation area or in lowest possible exposure area to reduce personnel exposure (ALARA). This procedure is to provide a mechanism to assist in fully characterizing the volume and surface topology of the sludge currently deposited in the sandfilter backwash pit (SFBWP). Surveillance Systems Engineering (SSE) personnel will gather visual information utilizing a closed circuit television (CCTV) color camera, mounted to stainless steel extension poles. Connections allow the camera to be connected with a pan and tilt to allow better positioning capabilities and to get good landscape profiling of the sediment surface. The information will be videotaped to a one-half inch NTSC or Y/C format. Underwater lighting will be accomplished by means of 500 watt underwater lamps.

  3. 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.

  4. EARTHSAWtm IN-SITU CONTAINMENT OF PITS AND TRENCHES

    International Nuclear Information System (INIS)

    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

  5. V-pits as Barriers to Diffusion of Carriers in InGaN/GaN Quantum Wells

    Science.gov (United States)

    Sheen, Mi-Hyang; Kim, Sung-Dae; Lee, Jong-Hwan; Shim, Jong-In; Kim, Young-Woon

    2015-11-01

    The luminescence characteristics of V-pits in InGaN/GaN quantum wells (QW) correlated directly with the microstructure of the V-pits, as studied by use of transmission electron microscopy with cathodoluminescence. {10-11}-Faceted V-pits, formed in the QW, produce more intense blue-shifted emission than {0001}-plane QW. A dead emission center seems to be present at the corner of the V-pit which connects the R-plane and C-plane QW. High-resolution transmission electron microscopy revealed formation of indium-deficient QW at the corners of the V-pits. High potential barriers occur because of the lack of indium around the hexagonal V-pit; this effectively blocks diffusion of carriers into the threading dislocations known to be non-radiative recombination centers. V-pits thus have promise for improving the internal quantum efficiency of light-emitting diodes.

  6. Evaluation of localized corrosion in duplex stainless steel aged at 850 deg. C with critical pitting temperature measurement

    Energy Technology Data Exchange (ETDEWEB)

    Deng Bo [Department of Material Science, Fudan University, Han Dan Road 220, Shanghai 200433 (China); Wang Zhiyu [Institute of Stainless Steel, Baosteel Co., LTD., Shanghai 201900 (China); Jiang Yiming; Wang Hao; Gao Juan [Department of Material Science, Fudan University, Han Dan Road 220, Shanghai 200433 (China); Li Jin [Department of Material Science, Fudan University, Han Dan Road 220, Shanghai 200433 (China)], E-mail: jinli@fudan.edu.cn

    2009-04-01

    Effect of aging at 850 deg. C on pitting corrosion of UNS S31803 duplex stainless steel was examined in chloride solution by potentiostatic critical pitting temperature (CPT) measurements. The quantitative metallography coupled with X-ray diffraction technique was employed to follow the microstructure evolution. Moreover, the initiation and propagation of pitting corrosion had been imaged in relation to microstructure variations using scanning electron microscopy (SEM). The results demonstrated that the corrosion behavior is strongly dependent on the microstructure, namely the presence of sigma phase. A deterioration of pitting corrosion resistance is found after aging 4 min, resulting in a drop in CPT. In particular, the metastable current transients during CPT test can clearly reflect the initiation of pitting process. Pitting nucleates preferentially in the austenite phase for the solution-annealed specimen, while the initiation of pitting corrosion takes place around sigma phase, in the newly formed secondary austenite for the aged specimen.

  7. Fractal Characteristic of Pits Distribution on 304 Stainless Steel Corroded Surface and Its Application in Corrosion Diagnosis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Electrochemical techniques and fractal theory were employed to study the corrosion behaviors and pits distribution characteristics on the corroded surfaces of 304 stainless steel exposed in FeCl3 solution.Fractal features of pits distribution over the corroded surfaces were observed and described by the fractal dimension. A 5-8-2 back-propagation (BP) artificial neural network model for the diagnoses of the pitting corrosion rate and pits deepness of 304 stainless steel under various conditions was developed by considering the fractal dimension as a key parameter for describing the pitting corrosion characteristics. The predicted results are well in agreement with the experimental data of pitting corrosion rate and pit deepness. The max relative errors between their experimental and simulation data are 6.69% and 4.62%, respectively.

  8. Computer-Assisted Detection of Collapse Pits in LROC NAC Images

    Science.gov (United States)

    Wagner, R. V.; Robinson, M. S.

    2012-12-01

    Pits in mare basalts and impact melt deposits provide unique environments for human shelters and preservation of geologic information. Due to their steep walls, pits are most distinguishable when the Sun is high (pit walls are casting shadows and impact crater walls are not). Because of the large number of NAC images acquired every day (>350), each typically with 5000 samples and 52,224 lines, it is not feasible to carefully search each image manually, so we developed a shadow detection algorithm (Pitscan) which analyzes an image in thirty seconds. It locates blocks of pixels that are below a digital number (DN) cutoff value, indicating that the block of pixels is "in shadow", and then runs a DN profile in the direction of solar lighting, comparing average DN values of the up-Sun and down-Sun sides. If the up-Sun average DN is higher than the down-Sun average, the shadow is assumed to be from a positive relief feature, and ignored. Otherwise, Pitscan saves a 200 x 200 pixel sub-image for later manual review. The algorithm currently generates ~150 false positives for each successful pit identification. This number would be unacceptable for an algorithm designed to catalog a common feature, but since the logic is merely intended to assist humans in locating an unusual type of feature, the false alarm rate is acceptable, and the current version allows a human to effectively check 10,000 NAC images for pits (over 2500 gigapixels) per hour. The false negative rate is not yet known, however Pitscan detected every pit in a test on a small subset of the images known to contain pits. Pitscan is only effective when the Sun is within 50° of the zenith. When the Sun is closer to the horizon crater walls often cast shadows, resulting in unacceptable numbers of false positives. Due to the Sun angle limit, only regions within 50° latitude of the equator are searchable. To date, 25.42% of the Moon has been imaged within this constraint. Early versions of Pitscan found more than

  9. 一体式电缆井的使用%Use of Integrated Cable Pit

    Institute of Scientific and Technical Information of China (English)

    蒋彦; 韦玮; 谈东波

    2012-01-01

    通过分析现有室外电缆井施工存在的不足,提出预制一体式电缆井的解决方案。分析一体式电缆井的技术优势、施工方法和注意事项,说明一体式电缆井的可实施性和推广价值。%Ac cording to the analysis on the disadvantages of construction of existing outdoor cable pits, a solution for prefabricated integrated cable pits is proposed. The technical advantages, construction methods and precautions of integrated cable pits are analyzed, and the practicality and promotion value of integrated cable pits is explained

  10. Pitting corrosion behaviour of austenitic stainless steels - combining effects of Mn and Mo additions

    International Nuclear Information System (INIS)

    Mn and Mo were introduced in AISI 304 and 316 stainless steel composition to modify their pitting corrosion resistance in chloride-containing media. Corrosion behaviour was investigated using gravimetric tests in 6 wt.% FeCl3, as well as potentiodynamic and potentiostatic polarization measurements in 3.5 wt.% NaCl. Additionally, the mechanism of the corrosion attack developed on the material surface was analysed by scanning electron microscopy (SEM), X-ray mapping and energy dispersive X-ray (EDX) analysis. The beneficial effect of Mo additions was assigned to Mo6+ presence within the passive film, rendering it more stable against breakdown caused by attack of aggressive Cl- ions, and to the formation of Mo insoluble compounds in the aggressive pit environment facilitating the pit repassivation. Conversely, Mn additions exerted an opposite effect, mainly due to the presence of MnS inclusions which acted as pitting initiators

  11. Pitting growth modelling in buried oil and gas pipelines using statistical techniques

    International Nuclear Information System (INIS)

    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.

  12. Impact of forming, welding, and electropolishing on pitting and the surface finish of SRF cavity niobium

    International Nuclear Information System (INIS)

    A broad range of coupon electropolishing experiments are described to ascertain the mechanism(s) by which large defects are formed near superconducting radiofrequency (SRF) cavity welds. Cold-worked vs. annealed metal, the presence of a weld, and several variations of electropolishing (EP) parameters were considered. Pitting is strongly promoted by cold work and agitation of the EP solution. Welding also promotes pitting, but less so compared with the other factors above. Temperature increase during EP did not strongly affect glossiness or pitting, but the reduced viscosity made the electrolyte more susceptible to agitation. The experiments suggest that several factors that are rather benign alone are combined by the cavity forming, welding, and processing sequence to promote the formation of defects such as pits. Process changes to mitigate these risks are discussed.

  13. 21 CFR 872.3765 - Pit and fissure sealant and conditioner.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3765 Pit and fissure sealant and... depressions (faults in the enamel) in the biting surfaces of teeth to prevent cavities. (b)...

  14. Numerical simulation on submerged gas jet scouring pit morphology in impingement water bath dust removers

    Institute of Scientific and Technical Information of China (English)

    GAO Huijie; WU Xuan; ZHAO Yuxiang; WU Wenfei; LI Baowei

    2014-01-01

    The VOF interface tracking method was adopted to simulate the two-dimensional submerged gas jet scouring pit morphology in an impingement water bath dust remover.The interaction of gas/liquid two-phase was obtained by force balance and momentum exchange.On the self-designed impingement water bath dust remover test bench,the submerged gas jet flushing with different gas velocities was simulated. The results show that,the gas inlet velocity is one of the main factors affecting the submerged gas jet scou-ring pit characteristics.The unique nature of gas/liquid two-phase determines their unique way of move-ment,thus affects the morphological character of the scouring pit in the expansion lag phase.Within the study range,the characteristic radius and impact depth of the scouring pit increases with the gas velocity, and so are their growth rates.

  15. 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...

  16. EIS study on pitting corrosion of 7150 aluminum alloy in sodium chloride and hydrochloric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Peng, G.S; Chen, K.H.; Fang, H.C.; Chao, H.; Chen, S.Y. [State Key Laboratory for Powder Metallurgy, Central South University, Hunan (China)

    2010-09-15

    The pitting corrosion behavior of 7150 aluminum alloy was studied by electrochemical impedance spectroscopy (EIS) in the sodium chloride and hydrochloric acid solution. Based on EIS features and corrosion morphologies as well as corrosion potential, the process of pitting corrosion could be clearly divided into four stages: at the first stage, the Nyquist diagram was composed of two overlapping capacitive loops at the high-medial frequency and one inductive loop at the low frequency. At the second stage (metastable pits developing stage), there existed one small capacitive loop at the high frequency and one big capacitive loop at the medial frequency. At the third stage (stable pits developing stage), two time constants were more clearly distinguished, corresponding to two obvious capacitive loops. At the fourth stage, there appeared one capacitive loop, attributing to uniform corrosion. An equivalent circuit was designed to fit EIS, and the experimental results and the fitted results had good correspondence. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  17. Study on Deep Well Dewatering Optimization Design in Deep Foundation Pit and Engineering Application

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Based on analyses of the theories of groundwater unsteady flow in deep well dewatering in the deep foundation pit, Theis equations are chosen to calculate and analyze the relationship between water level drawdown of confined aquifer and dewatering duration. In order to reduce engineering cost and diminish detrimental effect on ambient surrounding, optimization design target function based on the control of confined water drawdown and four restriction requisitions based on the control of safe water level, resistance to throwing up from the bottom of foundation pit, avoiding excessively great subsidence and unequal surface subsidence are proposed. A deep well dewatering project in the deep foundation pit is optimally designed. The calculated results including confined water level drawdown and surface subsidence are in close agreement with the measured results, and the optimization design can effectively control both surface subsidence outside foundation pit and unequal subsidence as a result of dewatering.

  18. Impact of forming, welding, and electropolishing on pitting and the surface finish of SRF cavity niobium

    Energy Technology Data Exchange (ETDEWEB)

    Cooley, L.D.; Burk, D.; Cooper, C.; Dhanaraj, N.; Foley, M.; Ford, D.; Gould, K.; Hicks, D.; Novitski, R.; Romanenko, A.; Schuessler, R.; /Fermilab

    2010-07-01

    A broad range of coupon electropolishing experiments are described to ascertain the mechanism(s) by which large defects are formed near superconducting radiofrequency (SRF) cavity welds. Cold-worked vs. annealed metal, the presence of a weld, and several variations of electropolishing (EP) parameters were considered. Pitting is strongly promoted by cold work and agitation of the EP solution. Welding also promotes pitting, but less so compared with the other factors above. Temperature increase during EP did not strongly affect glossiness or pitting, but the reduced viscosity made the electrolyte more susceptible to agitation. The experiments suggest that several factors that are rather benign alone are combined by the cavity forming, welding, and processing sequence to promote the formation of defects such as pits. Process changes to mitigate these risks are discussed.

  19. Submersible observations of an iceberg pit and scour on the Grand Banks of Newfoundland

    Science.gov (United States)

    Barrie, J. V.; Lewis, C. F. M.; Parrott, D. R.; Collins, W. T.

    1992-03-01

    An elongated sea bed depression (pit), 80 by 125 m and 10 m deep located on the Grand Banks of Newfoundland was identified on high resolution surficial geophysical survey lines and investigated using a manned submersible. The pit occurs at the termination of a long (greater than 3 km) iceberg scour, 1.5 m deep, and 80 m wide in 91 m of water. It is similar to other depressions in the region that indent the sea bed up to seven times deeper than the surrounding deepest iceberg furrows. The pit is interpreted to be the sea bed response to impact and loading by a rolling and grounding iceberg. The iceberg scour and pit appear to be of recent origin.

  20. Role of heat tint on pitting corrosion of 304 austenitic stainless steel in chloride environment

    International Nuclear Information System (INIS)

    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)

  1. Fabrication of high nitrogen austenitic stainless steels with excellent mechanical and pitting corrosion properties

    Institute of Scientific and Technical Information of China (English)

    Hua-bing Li; Zhou-hua Jiang; Yang Cao; Zu-rui Zhang

    2009-01-01

    18Cr18Mn2Mo0.9N high nitrogen austenitic stainless steel exhibits high strength and good ductility at room temperature. The steel shows typical duc-tile-brittle transition behavior and excellent pitting corrosion resistance properties.

  2. EVALUATION OF THE PROBABILITY DISTRIBUTION OF PITTING CORROSION FATIGUE LIFE IN AIRCRAFT MATERIALS

    Institute of Scientific and Technical Information of China (English)

    王清远; N.KAWAGOISHI; Q.CHEN; R.M.PIDAPARTI

    2003-01-01

    Corrosion and fatigue properties of aircraft materials axe known to have a considerablescatter due to the random nature of materials, loading, and environmental conditions. A probabilisticapproach for predicting the pitting corrosion fatigue life has been investigated which captures the effectof the interaction of the cyclic load and corrosive environment and all stages of the corrosion fatigueprocess (i.e. the pit nucleation and growth, pit-crack transition, short- and long-crack propagation).The probabilistic model investigated considers the uncertainties in the initial pit size, corrosion pittingcurrent, and material properties due to the scatter found in the experimental data. Monte Carlo simu-lations were performed to define the failure probability distribution. Predicted cumulative distributionfunctions of fatigue life agreed reasonably well with the existing experimental data.

  3. Norm Levels in Mine Pit Lakes in South-Western Spain

    International Nuclear Information System (INIS)

    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)

  4. Pitting corrosion and stress corrosion of Zircaloy 4 in neutral chloride environment

    International Nuclear Information System (INIS)

    In a first part, this research thesis describes the electrochemical methods which are generally used to characterize sensitivity to pitting corrosion of metallic materials, presents the method used for the statistical analysis of pitting initiation as well as results obtained in the case of Zircaloy 4 in a neutral chloride environment. This reveals that passivity film thickness is a critical parameter for the understanding of observed behaviours, and therefore required the study of passivity film formation kinetics. Thus established passivity rules are then used to study the influence of passive film evolution on behaviour in terms of pitting corrosion. Experimental results are then compared with published results. The second part addresses the determination of sensitivity to stress corrosion of the same alloy in the same environment. It aims at trying to identify correlations between sensitivity to this type of corrosion and sensitivity to pitting corrosion

  5. Effects of Inclusions in HSLA Carbon Steel on Pitting Corrosion in CaCl2

    Energy Technology Data Exchange (ETDEWEB)

    M. Ziomek-Moroz; S. Bullard; K. Rozman; J.J. Kruzic

    2011-12-05

    Susceptibility of high strength low alloy steel to localized corrosion was studied in 6.7 M CaCl{sub 2} for oil and natural gas drilling applications. Results of the immersion and electrochemical experiments showed that the steel is susceptible to pitting corrosion. Optical microscopy investigations of the polished samples revealed that 10% of the surface area was occupied by defects in the form of pits. The energy dispersive X-ray (EDX) and wavelength dispersive X-ray (WDX) chemical analyses revealed higher concentrations of Mn and S compared to the metal matrix in defected areas. These areas served as the sites for development of corrosion pits during both immersion and electrochemical experiments. The fatigue results of the corroded samples indicate that if the pit was the most significant defect, the fatigue crack initiated and propagated at this site.

  6. Radiological survey report for the Weldon Spring Raffinate Pits site, Weldon Spring, Missouri

    International Nuclear Information System (INIS)

    The Weldon Spring Site (WSS) is a US Department of Energy (DOE) surplus facility comprising the Raffinate Pits facility, the Quarry, and potentially contaminated vicinity properties. Radiological characterization of the WSS will be conducted in three phases: the Raffinate Pits facility, Quarry, and the vicinity properties. Bechtel National, Inc. (BNI) and its radiological support subcontractor, Eberline Instrument Corporation (EIC), conducted a radiological characterization survey of the Raffinate Pits during 1982 and 1983 in support of on-site construction work and a technical evaluation of site geology. The survey consisted of direct beta-gamma surface readings, near-surface gamma readings, exposure level measurements, and gamma-logs of boreholes. Soil samples were also collected from the surface, shallow boreholes, and trenches on the site. This report describes the radiological characterization of the Raffinate Pits facility, the procedures used to conduct the survey, the survey results, and their significance. 5 references, 9 figures, 8 tables

  7. SLOPE INSTABILITY IN OPEN PITS AND AN EXAMPLE OF A RETROSPECTIVE ANALYSIS: AFŞİN-ELBİSTAN-KIŞLAKÖY OPEN PIT COAL DEPOSIT

    OpenAIRE

    AKBULUT, İbrahim; ÇAM, İlker; AKSOY, Tahsin; ÇAĞLAN, Dinçer; ÖLMEZ, Tolga

    2013-01-01

    The subject of this study is to study the instabilities that have developed in the permanent east and west slopes of the Kışlaköy open pit of the Elektrik Üretim A.Ş. Afşin-Elbistan Linyitleri İşletmesi and to work out the sliding mechanism causing it. In the Kışlaköy open pit to establish if mass movement is continuing and if so which direction it would move, amount of mass to be involved and the failing model. Six movement control observations stations were established along 3 lines in each...

  8. Randomised controlled double-blind non-inferiority trial of two antivenoms for saw-scaled or carpet viper (Echis ocellatus envenoming in Nigeria.

    Directory of Open Access Journals (Sweden)

    Isa S Abubakar

    Full Text Available BACKGROUND: In West Africa, envenoming by saw-scaled or carpet vipers (Echis ocellatus causes great morbidity and mortality, but there is a crisis in supply of effective and affordable antivenom (ISRCTN01257358. METHODS: In a randomised, double-blind, controlled, non-inferiority trial, "EchiTAb Plus-ICP" (ET-Plus equine antivenom made by Instituto Clodomiro Picado was compared to "EchiTAb G" (ET-G ovine antivenom made by MicroPharm, which is the standard of care in Nigeria and was developed from the original EchiTAb-Fab introduced in 1998. Both are caprylic acid purified whole IgG antivenoms. ET-G is monospecific for Echis ocellatus antivenom (initial dose 1 vial and ET-Plus is polyspecific for E. ocellatus, Naja nigricollis and Bitis arietans (initial dose 3 vials. Both had been screened by pre-clinical and preliminary clinical dose-finding and safety studies. Patients who presented with incoagulable blood, indicative of systemic envenoming by E. ocellatus, were recruited in Kaltungo, north-eastern Nigeria. Those eligible and consenting were randomly allocated with equal probability to receive ET-Plus or ET-G. The primary outcome was permanent restoration of blood coagulability 6 hours after the start of treatment, assessed by a simple whole blood clotting test repeated 6, 12, 18, 24 and 48 hr after treatment. Secondary (safety outcomes were the incidences of anaphylactic, pyrogenic and late serum sickness-type antivenom reactions. FINDINGS: Initial doses permanently restored blood coagulability at 6 hours in 161/194 (83.0% of ET-Plus and 156/206 (75.7% of ET-G treated patients (Relative Risk [RR] 1.10 one-sided 95% CI lower limit 1.01; P = 0.05. ET-Plus caused early reactions on more occasions than did ET-G [50/194 (25.8% and 39/206 (18.9% respectively RR (1.36 one-sided 95% CI 1.86 upper limit; P = 0.06. These reactions were classified as severe in 21 (10.8% and 11 (5.3% of patients, respectively. CONCLUSION: At these doses, ET-Plus was

  9. Herniation pits and their renaissance in association with femoroacetabular impingement; Herniation Pits und ihre Renaissance im Zusammenhang mit femoroazetabulaerem Impingement

    Energy Technology Data Exchange (ETDEWEB)

    Panzer, Stephonie [Unfallklinik Murnau (Germany). Radiologie; Augat, P. [Unfallklinik Murnau (Germany). Radiologie; Paracelsus Univ. Salzburg (Austria). Biomechanisches Labor; Scheidler, J. [Radiologischs Zentrum Muenchen-Pasing (Germany). Radiologie

    2010-07-15

    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. Short convalescence and minimal pain after out-patient Bascom's pit-pick operation

    DEFF Research Database (Denmark)

    Colov, Emilie Palmgren; Bertelsen, Claus Anders

    2011-01-01

    Treatment of pilonidal sinuses with Bascom's pit-pick operation can easily be performed under local analgesia. We describe pain during and after the operation, time to return to work, time to healing and success rate.......Treatment of pilonidal sinuses with Bascom's pit-pick operation can easily be performed under local analgesia. We describe pain during and after the operation, time to return to work, time to healing and success rate....

  11. A structural and compositional analysis of intervessel pit membranes in the sapwood of some mangrove woods

    OpenAIRE

    Schmitz, N.; Koch, G; Beeckman, H.; N. Koedam; Robert, E.M.R.; Schmitt, U.

    2012-01-01

    Intervessel pits are prominent wall structures involved in the water transport mechanism of land plants. The role of their intra-tree variation in the regulation of water transport, however, remains enigmatic. The hypothesis was tested that pit membrane thickness and degree of impregnation with phenolic substances increase along the stem axis with increasing tension on the water column as an adaptation to the higher risk for cavitation. Wood samples were taken at different heights from the ma...

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

    International Nuclear Information System (INIS)

    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

  13. Bench stability in open pit mines : a methodology for jointed rock masses

    OpenAIRE

    Baroudi, Hafid; D. Hantz; Asof, P.D.; Piguet, Jack-Pierre

    1992-01-01

    The methods used to determine the overall gradients of the slopes in open pit workings aim to sufficiently eliminate all risk of failure on a scale comparable wich the pit walls. For this the slopes musc be made shallow gradual and reinforcing measures must generally be applied. Most often these consist of ensuring the drainage of the slopes and in limiting the effects of blasting (reinforcement is generally too costly in the case of very high slopes and deep planes of failure).

  14. Geodetic determining of stockpile volume of mineral excavated in open pit mine

    OpenAIRE

    Labant, Slavomír; Staňková, Hana; Weiss, Roland

    2013-01-01

    In the contemporary geodetic practice it is practically a must to use modern geodetic apparatuses and a variety of the CAD (Computer Aided Design) software for processing and visualising spatial data. The present paper deals with geodetic surveying of Kecerovce open pit mine to determine, for the purpose of mine reopening and commencing with mining of andesite, the volume of non-extracted volumes of andesite. The open pit mine is situated on the foot of Slanské vrchy mountain range. Determini...

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  16. Evidence from lateral mobility studies for dynamic interactions of a mutant influenza hemagglutinin with coated pits

    OpenAIRE

    1991-01-01

    Replacement of cysteine at position 543 by tyrosine in the influenza virus hemagglutinin (HA) protein enables the endocytosis of the mutant protein (Tyr 543) through coated pits (Lazarovits, J., and M. G. Roth. 1988. Cell. 53:743-752). To investigate the interactions between Tyr 543 and the clathrin coats in the plasma membrane of live cells, we performed fluorescence photobleaching recovery measurements comparing the lateral mobilities of Tyr 543 (which enters coated pits) and wild- type HA ...

  17. Serial-section analysis of coated pits and vesicles involved in adsorptive pinocytosis in cultured fibroblasts

    OpenAIRE

    1983-01-01

    We have examined, by analyzing thin (15-20 nm) serial sections, whether coated pits involved in adsorptive pinocytosis in cultured fibroblasts give rise to free coated vesicles or represent permanently surface- associated structures from the neck of which uncoated receptosomes pinch off and carry ligand into the cell. Human skin fibroblasts and mouse L-929 fibroblasts were incubated with cationized ferritin (CF), a ligand known to bind to coated pit regions, at 37 degrees C before fixation. I...

  18. Temporary protection of construction pit for pump station and service shaft

    OpenAIRE

    Šubic, Andrej

    2010-01-01

    The thesis deals with geostatic analysis of temporary excavation pit for installation of pump station and service shaft. They are part of the project named Renewal of public sewerage, waterwork and road reconstruction in Savska cesta in Kranj. Nearby buildings, local road, Kokra river and design depth of pump station dictate realization of temporary protection of construction pit under phreatic level. Analysis are executed analytically and numericaly using computer program Plaxis. Analyticall...

  19. 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.

  20. An experimental feasibility study of pipeline corrosion pit detection using a piezoceramic time reversal mirror

    Science.gov (United States)

    Du, Guofeng; Kong, Qingzhao; Wu, Fanghong; Ruan, Jiabiao; Song, Gangbing

    2016-03-01

    Corrosion pits on pipelines lead to the formation of small holes, which cause further pipeline damage and even catastrophic consequences. Since many pipelines are located underground, the detection of corrosion pits on pipelines in real time is still an engineering challenge. In this paper, an experimental feasibility study on pipeline corrosion pit detection using the time reversal technique with a piezoceramic transducer as a time reversal mirror was investigated. A specimen of steel pipeline section was fabricated with an artificially drilled hole, which was to mimic a corrosion pit. By gradually increasing the depth of the hole, the evolution of the corrosion pit on the pipeline was simulated and studied. Two piezoceramic transducers were employed to generate a stress wave to propagate along the pipeline and to detect the propagated stress wave. With both the properties of sensing and actuating functions, a piezoceramic transducer was used as a time reversal mirror, which first detected the propagated stress wave signal and then sent ‘back’ the time-reversed signal as a propagating stress wave. With the inherent auto-focusing property of the time reversal technique, the detected time-reversed stress wave had a distinct focused peak. A corrosion pit on a pipeline, as a structural defect, reduces the energy of the focused signal received by the piezoceramic sensor and the attenuation ratio of the focused signal depends strongly on the degree of corrosion depth. Experimental results show that the amplitudes of the focused signal peak decrease with the increase of corrosion pit depth and we can use the peak amplitude of the focused signal to determine the state of pipeline corrosion. The time reversal based method proposed in this paper shows the potential to quantitatively monitor the damage degree of corrosion pits on pipelines in real time.

  1. Predicting pitting damage during processing in California clingstone peaches using color and firmness measurements

    OpenAIRE

    Crisosto, Carlos H; Valero Ubierna, Constantino; Slaughter, David

    2007-01-01

    Nondestructive and destructive measures of color and firmness were studied to determine the feasibility of predicting the level of damage to clingstone peaches during mechanical pitting. Nondestructive and destructive measures of firmness were equally variable when measuring the firmness at three equatorial cheek locations (coefficient of variation of about 17%), both had inverse relationships with the level of pitting damage (r2 ranged from 0.70 to 0.83), and could classify peaches into two ...

  2. The chemical identity of intervessel pit membranes in Acer challenges hydrogel control of xylem hydraulic conductivity

    Science.gov (United States)

    Klepsch, Matthias M.; Schmitt, Marco; Paul Knox, J.; Jansen, Steven

    2016-01-01

    Ion-mediated enhancement of the hydraulic conductivity of xylem tissue (i.e. the ionic effect) has been reported for various angiosperm species. One explanation of the ionic effect is that it is caused by the swelling and shrinking of intervessel pit membranes due to the presence of pectins and/or other cell-wall matrix polymers such as heteroxylans or arabinogalactan–proteins (AGPs) that may contain acidic sugars. Here, we examined the ionic effect for six Acer species and their pit membrane chemistry using immunocytochemistry, including antibodies against glycoproteins. Moreover, anatomical features related to the bordered pit morphology and vessel dimensions were investigated using light and electron microscopy. The ionic effect varied from 18 % (± 9) to 32 % (± 13). Epitopes of homogalacturonan (LM18) and xylan (LM11) were not detected in intervessel pit membranes. Negative results were also obtained for glycoproteins (extensin: LM1, JIM20; AGP glycan: LM2), although AGP (JIM13)-related epitopes were detected in parenchyma cells. The mean vessel length was significantly correlated with the magnitude of the ionic effect, unlike other pit or vessel-related characteristics. Our results suggest that intervessel pit membranes of Acer are unlikely to contain pectic or other acidic polysaccharides. Therefore, alternative explanations should be tested to clarify the ionic effect. PMID:27354661

  3. 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.

  4. The effect of tempering temperature on pitting corrosion resistance of 420 stainless steels

    Science.gov (United States)

    Anwar, Moch. Syaiful; Prifiharni, Siska; Mabruri, Efendi

    2016-04-01

    The AISI Type 420 stainless steels are commonly used to steam generators, mixer blades, etc. These stainless steels are most prone to pitting in dissolved Cl- containing environments. In this paper, the effect of tempering temperature on pitting corrosion resistance of AISI Type 420 stainless steels was studied. The AISI Type 420 stainless steels specimens were heat treated at the temperature of 1050°C for 1 hour to reach austenite stabilization and then quench in the oil. After that, the specimens were tempered at the temperature of 150, 250, 350 and 450°C for 30 minutes and then air cooled to the room temperature. The electrochemical potentiodynamic polarization test was conducted at 3.5% sodium chloride solution to evaluate corrosion rate and pitting corrosion behaviour. The Scanning Electron Microscope (SEM), Energy Dispersive X-Ray Spectroscopy (EDS) were used to evaluate the pitting corrosion product. The result have shown that highest pitting potential was found in the sample tempered at 250°C and corrosion pits were found to initiate preferentially around chromium carbides.

  5. Pit formation on the Ge (1 0 0) surfaces by normal incident Si- ion implantation

    Science.gov (United States)

    Mollick, S. A.; Karmakar, S.; Metya, A.; Ghose, D.

    2012-02-01

    We have observed micron size pit formation on Ge surface due to bombardment of 26 keV Si- ion at normal incidence in the fluence range 1 × 1018 and 7 × 1018 ions/cm2. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) are used to follow the evolution of the surface morphology. The pits are of various shapes, e.g., crescent-shaped, kidney-like or circular structures. The two-field continuum model developed for small slope approximations can describe the pit formation and growth at the very beginning of ion bombardment. The growth of the pits at late times (high fluence) can be explained by the gradient dependent erosion mechanisms due to primary ion beam as well by secondary flux of particles originating from steep slopes. Energy dispersive X-ray analysis attached to SEM is employed to obtain the chemical information of the pitted surface. The depletion of Si at the bottom of the pits is explained due to lower diffusivity of Si in Ge.

  6. Acidic pit lakes. The legacy of coal and metal surface mines

    Energy Technology Data Exchange (ETDEWEB)

    Geller, Walter; Schultze, Martin [Helmholtz Centre for Environmental Research - UFZ, Magdeburg (Germany); Wolkersdorfer, Christian (eds.) [Cape Breton Univ., Sydney, NS (Canada). Industrial Research Chair in Mine Water Remediation and Management; International Mine Water Association, Wendelstein (Germany). General Secretary; Kleinmann, Robert

    2013-07-01

    This monograph provides an international perspective on pit lakes in post-mining landscapes, including the problem of geogenic acidification. Much has been learned during the last decade through research and practical experience on how to mitigate or remediate the environmental problems of acidic pit lakes. In the first part of the book, general scientific issues are presented in 21 contributions from the fields of geo-environmental science, water chemistry, lake physics, lake modeling, and on the peculiar biological features that occur in the extreme habitats of acidic pit lakes. Another chapter provides an overview of methods currently used to remediate acidic pit lakes and treat outflowing acidic water. The second part of the book is a collection of regional surveys of pit lake problems from three European countries and Australia, and case studies of various individual representative lakes. A final case study provides an innovative approach to assessing the economic value of new pit lakes and balancing the costs and benefits, a valuable tool for decision makers.

  7. The chemical identity of intervessel pit membranes in Acer challenges hydrogel control of xylem hydraulic conductivity.

    Science.gov (United States)

    Klepsch, Matthias M; Schmitt, Marco; Paul Knox, J; Jansen, Steven

    2016-01-01

    Ion-mediated enhancement of the hydraulic conductivity of xylem tissue (i.e. the ionic effect) has been reported for various angiosperm species. One explanation of the ionic effect is that it is caused by the swelling and shrinking of intervessel pit membranes due to the presence of pectins and/or other cell-wall matrix polymers such as heteroxylans or arabinogalactan-proteins (AGPs) that may contain acidic sugars. Here, we examined the ionic effect for six Acer species and their pit membrane chemistry using immunocytochemistry, including antibodies against glycoproteins. Moreover, anatomical features related to the bordered pit morphology and vessel dimensions were investigated using light and electron microscopy. The ionic effect varied from 18 % (± 9) to 32 % (± 13). Epitopes of homogalacturonan (LM18) and xylan (LM11) were not detected in intervessel pit membranes. Negative results were also obtained for glycoproteins (extensin: LM1, JIM20; AGP glycan: LM2), although AGP (JIM13)-related epitopes were detected in parenchyma cells. The mean vessel length was significantly correlated with the magnitude of the ionic effect, unlike other pit or vessel-related characteristics. Our results suggest that intervessel pit membranes of Acer are unlikely to contain pectic or other acidic polysaccharides. Therefore, alternative explanations should be tested to clarify the ionic effect. PMID:27354661

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

    International Nuclear Information System (INIS)

    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

  9. Crack Initiation Life of Materials Under Combined Pitting Corrosion and Cyclic Loading

    Science.gov (United States)

    Sriraman, M. R.; Pidaparti, R. M.

    2010-02-01

    Pitting corrosion triggered damage is responsible for the degradation of many metallic materials affecting structural integrity. As pitting and crack initiation processes govern the overall life of such structures and components, particularly at nominal cyclic stresses, there is a need to develop simple models to estimate crack initiation life of materials. This paper presents a simple deterministic model that considers the effect of cyclic stressing under pitting corrosion conditions. The developed model is validated on an aluminum alloy 2024-T3, and 12% Cr stainless steel used in aircraft and steam turbines, respectively. The predicted critical pit depth values are in fair agreement with the limited experimental data available in the literature. The model indicates that at high stresses, the crack initiation can occur very rapidly even from relatively small pits. The crack initiation life predictions when compared with the available experimental data, suggest a probable stress-level dependency with regard to the form and extent of the influence of cyclic stresses on pit growth and subsequent crack formation.

  10. Activation of the black seabream (Acanthopagrus schlegeli) somatolactin-alpha gene promoter by Pit-1c in the Hepa-T1 cell-line.

    Science.gov (United States)

    Tian, Jing; Chan, King Ming

    2010-03-01

    Somatolactin (SL) is a pituitary hormone of the growth hormone (GH) gene family found only in fish. To understand the regulation of this hormone at the level of gene transcription, we obtained a SLalpha gene from black seabream (bsb), with its 5' flanking promoter region carrying several putative transcription factors including seven binding sites for pituitary-specific transcription factor 1 (Pit-1). To study the actions of Pit-1 on this gene promoter, we cloned three variants of bsbPit-1 (Pit-1a, Pit-1b and Pit-1c) derived from alternative splicing of mRNA or differential transcription start sites from black seabream pituitary. The deduced amino acid sequences of these Pit-1s contained 371 amino acids (aa), 333 and 311aa for the three Pit-1 variants, Pit-1a, Pit-1b and Pit-1c, respectively, with diverse regions of Pit-1 located at the transactivation domain. The actions of bsbPit-1 variants on the bsbSL gene promoter were investigated using a co-transfection assay, with a reporter gene using a transient expression assay in Hepa-T1 cells. The N-terminus truncated isoform bsbPit-1c showed the highest level of activity on SLalpha gene promoter activation in Hepa-T1 cells; however, neither Pit-1a nor Pit-1b activated the bsbSL gene promoter in the same study. PMID:19766121

  11. Los Alamos National Laboratory W76 Pit Tube Lifetime Study

    Energy Technology Data Exchange (ETDEWEB)

    Abeln, Terri G. [Los Alamos National Laboratory

    2012-04-25

    A metallurgical study was requested as part of the Los Alamos National Laboratory (LANL) W76-1 life-extension program (LEP) involving a lifetime analysis of type 304 stainless steel pit tubes subject to repeat bending loads during assembly and disassembly operations at BWXT/Pantex. This initial test phase was completed during the calendar years of 2004-2006 and the report not issued until additional recommended tests could be performed. These tests have not been funded to this date and therefore this report is considered final. Tubes were reportedly fabricated according to Rocky Flats specification P14548 - Seamless Type 304 VIM/VAR Stainless Steel Tubing. Tube diameter was specified as 0.125 inches and wall thickness as 0.028 inches. A heat treat condition is not specified and the hardness range specification can be characteristic of both 1/8 and 1/4 hard conditions. Properties of all tubes tested were within specification. Metallographic analysis could not conclusively determine a specified limit to number of bends allowable. A statistical analysis suggests a range of 5-7 bends with a 99.95% confidence limit. See the 'Statistical Analysis' section of this report. The initial phase of this study involved two separate sets of test specimens. The first group was part of an investigation originating in the ESA-GTS [now Gas Transfer Systems (W-7) Group]. After the bend cycle test parameters were chosen (all three required bends subjected to the same amount of bend cycles) and the tubes bent, the investigation was transferred to Terri Abeln (Metallurgical Science and Engineering) for analysis. Subsequently, another limited quantity of tubes became available for testing and were cycled with the same bending fixture, but with different test parameters determined by T. Abeln.

  12. White phosphorus pits focused feasibility study final July 2007.

    Energy Technology Data Exchange (ETDEWEB)

    Davis, B.; Martino, L.

    2007-08-21

    The White Phosphorus Burning Pits (WPP) Area of Concern (AOC) is a site of about 5.5 acres (2.2 ha) located in the J-Field Study Area, in the Edgewood Area of Aberdeen Proving Ground (APG), Maryland (Figure 1.1). Considerable information about the WPP exists as a result of efforts to characterize the hazards associated with J-Field. Contamination in the J-Field Study Area was first detected during an environmental survey of the APG Edgewood Area conducted in 1977 and 1978 (Nemeth et al. 1983) by the U.S. Army Toxic and Hazardous Materials Agency (USATHAMA; predecessor to the U.S. Army Environmental Center). As part of a subsequent USATHAMA environmental survey, 11 wells were installed and sampled at J-Field (three of them at the WPP) (Nemeth 1989). Contamination was also detected in 1983 during a munitions disposal survey conducted by Princeton Aqua Science (1984). The Princeton Aqua Science investigation involved installing and sampling nine wells (four at the WPP) and collecting and analyzing surficial and deep composite soil samples (including samples from the WPP area). In 1986, the U.S. Environmental Protection Agency (EPA) issued a Resource Conservation and Recovery Act (RCRA) Permit (MD3-21-002-1355) requiring a post-wide RCRA Facility Assessment (RFA) and a hydrogeologic assessment of J-Field. In 1987, the U.S. Geological Survey (USGS) began a two-phase hydrogeologic assessment in which data were collected to model groundwater flow at J-Field. Soil-gas investigations were conducted, several well clusters were installed (four at the WPP), a groundwater flow model was developed, and groundwater and surface water monitoring programs were established that continue today. The results of the USGS study were published by Hughes (1993).

  13. Uranium activity ratio in water and fish from pit lakes in Kurday, Kazakhstan and Taboshar, Tajikistan

    International Nuclear Information System (INIS)

    Kurday in Kazhakstan and Taboshar in Tajikistan were U mining sites operated during the 1950s and 1960s as part of the USSR nuclear weapon program. Today, they represent sources of potential U contamination of the environment. Within both mining sites, open pits from which U ore was extracted have been filled with water due to ground water inflow and precipitation. These artificial pit lakes contain fish consumed occasionally by the local people, and wild and domestic animals are using the water for drinking purposes. To assess the potential impact from U in these pit lakes, field work was performed in 2006 in Kurday and 2006 and 2008 in Taboshar. Results show that the U concentration in the lake waters were relatively high, about 1 mg/L in Kurday Pit Lake and about 3 mg/L in Taboshar Pit Lake. The influence of U-bearing materials on the lakes and downstream waters were investigated by measuring the U concentration and the 234U/238U activity ratios. In both Kurday and Taboshar, the ratios increased distinctively from about 1 at the pit lakes to >1.5 far downstream the lakes. The concentrations of 238U in gill, liver, muscle and bones in fish from the pit lakes were much higher than in the reference fish. Peak concentration of U was seen in bones (13 mg/kg w.w.), kidney (9.1 mg/kg w.w.) and gills (8.9 mg/kg w.w.) from Cyprinus auratus caught in the Taboshar Pit Lake. Bioconcentration factors (BCF) calculated for organs from fish caught in the Taboshar Pit Lake, with the same tendency seen in the Kurday Pit Lake, showed that U accumulates most in bone (BCF = 4.8 L/kg w.w.), gills (BCF = 3.6 L/kg w.w.), kidney (BCF = 3.6 L/kg w.w.), and liver (BCF = 2.5 L/kg w.w.), while least was accumulated in the muscle (BCF = 0.12 L/kg w.w.)

  14. Analysis of the Potential for Use of Floating Photovoltaic Systems on Mine Pit Lakes: Case Study at the Ssangyong Open-Pit Limestone Mine in Korea

    Directory of Open Access Journals (Sweden)

    Jinyoung Song

    2016-02-01

    Full Text Available Recently, the mining industry has introduced renewable energy technologies to resolve power supply problems at mines operating in polar regions or other remote areas, and to foster substitute industries, able to benefit from abandoned sites of exhausted mines. However, little attention has been paid to the potential placement of floating photovoltaic (PV systems operated on mine pit lakes because it was assumed that the topographic characteristics of open-pit mines are unsuitable for installing any type of PV systems. This study analyzed the potential of floating PV systems on a mine pit lake in Korea to break this misconception. Using a fish-eye lens camera and digital elevation models, a shading analysis was performed to identify the area suitable for installing a floating PV system. The layout of the floating PV system was designed in consideration of the optimal tilt angle and array spacing of the PV panels. The System Advisor Model (SAM by National Renewable Energy Laboratory, USA, was used to conduct energy simulations based on weather data and the system design. The results indicated that the proposed PV system could generate 971.57 MWh/year. The economic analysis (accounting for discount rate and a 20-year operational lifetime showed that the net present value would be $897,000 USD, and a payback period of about 12.3 years. Therefore, we could know that the economic effect of the floating PV system on the mine pit lake is relatively higher than that of PV systems in the other abandoned mines in Korea. The annual reduction of greenhouse gas emissions was analyzed and found to be 471.21 tCO2/year, which is twice the reduction effect achieved by forest restoration of an abandoned mine site. The economic feasibility of a floating PV system on a pit lake of an abandoned mine was thus established, and may be considered an efficient reuse option for abandoned mines.

  15. A generic statistical methodology to predict the maximum pit depth of a localized corrosion process

    International Nuclear Information System (INIS)

    Highlights: → We propose a methodology to predict the maximum pit depth in a corrosion process. → Generalized Lambda Distribution and the Computer Based Bootstrap Method are combined. → GLD fit a large variety of distributions both in their central and tail regions. → Minimum thickness preventing perforation can be estimated with a safety margin. → Considering its applications, this new approach can help to size industrial pieces. - Abstract: This paper outlines a new methodology to predict accurately the maximum pit depth related to a localized corrosion process. It combines two statistical methods: the Generalized Lambda Distribution (GLD), to determine a model of distribution fitting with the experimental frequency distribution of depths, and the Computer Based Bootstrap Method (CBBM), to generate simulated distributions equivalent to the experimental one. In comparison with conventionally established statistical methods that are restricted to the use of inferred distributions constrained by specific mathematical assumptions, the major advantage of the methodology presented in this paper is that both the GLD and the CBBM enable a statistical treatment of the experimental data without making any preconceived choice neither on the unknown theoretical parent underlying distribution of pit depth which characterizes the global corrosion phenomenon nor on the unknown associated theoretical extreme value distribution which characterizes the deepest pits. Considering an experimental distribution of depths of pits produced on an aluminium sample, estimations of maximum pit depth using a GLD model are compared to similar estimations based on usual Gumbel and Generalized Extreme Value (GEV) methods proposed in the corrosion engineering literature. The GLD approach is shown having smaller bias and dispersion in the estimation of the maximum pit depth than the Gumbel approach both for its realization and mean. This leads to comparing the GLD approach to the GEV one

  16. Closure Report for Corrective Action Unit 544: Cellars, Mud Pits, and Oil Spills, Nevada National Security Site, Nevada, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Mark Krauss and Catherine Birney

    2011-05-01

    This Closure Report (CR) presents information supporting the closure of Corrective Action Unit (CAU) 544: Cellars, Mud Pits, and Oil Spills, Nevada National Security Site, Nevada. This CR complies with the requirements of the Federal Facility Agreement and Consent Order that was agreed to by the State of Nevada; U.S. Department of Energy (DOE), Environmental Management; U.S. Department of Defense; and DOE, Legacy Management. The corrective action sites (CASs) within CAU 544 are located within Areas 2, 7, 9, 10, 12, 19, and 20 of the Nevada National Security Site. Corrective Action Unit 544 comprises the following CASs: • 02-37-08, Cellar & Mud Pit • 02-37-09, Cellar & Mud Pit • 07-09-01, Mud Pit • 09-09-46, U-9itsx20 PS #1A Mud Pit • 10-09-01, Mud Pit • 12-09-03, Mud Pit • 19-09-01, Mud Pits (2) • 19-09-03, Mud Pit • 19-09-04, Mud Pit • 19-25-01, Oil Spill • 19-99-06, Waste Spill • 20-09-01, Mud Pits (2) • 20-09-02, Mud Pit • 20-09-03, Mud Pit • 20-09-04, Mud Pits (2) • 20-09-06, Mud Pit • 20-09-07, Mud Pit • 20-09-10, Mud Pit • 20-25-04, Oil Spills • 20-25-05, Oil Spills The purpose of this CR is to provide documentation supporting the completed corrective actions and data confirming that the closure objectives for CASs within CAU 544 were met. To achieve this, the following actions were performed: • Review the current site conditions, including the concentration and extent of contamination. • Implement any corrective actions necessary to protect human health and the environment. • Properly dispose of corrective action and investigation wastes. • Document Notice of Completion and closure of CAU 544 issued by the Nevada Division of Environmental Protection.

  17. Obesity and African Americans

    Science.gov (United States)

    ... Data > Minority Population Profiles > Black/African American > Obesity Obesity and African Americans African American women have the ... ss6304.pdf [PDF | 3.38MB] HEALTH IMPACT OF OBESITY More than 80 percent of people with type ...

  18. Pitting corrosion resistance of high-alloy OCTG in CO2 environment as affected by chlorides and sulfides

    International Nuclear Information System (INIS)

    High general corrosion resistance of high-alloy OCTG (oil country tubular goods) to CO2 may be limited by pitting corrosion in presence of chlorides and sulfides. The pitting resistance of 13% Cr steel, duplex and high Ni austenitic stainless steels have been examined by electrochemical measurements in a high temperature, high pressure autoclave simulating the well conditions. Each steel shows the pitting potential in CO2-NaCl-H2O system, the value of which being less noble as the Cl- concentration and the temperature increase. The presence of H2S is also detrimental. High alloying additions of Cr and Mo enhance pitting resistance whether or not H2S is present. The corrosion potentials of these steels in the simulating well conditions in which oxygen is absent do not exceed the pitting potential. Therefore, pitting corrosion can not occur by the passivity break through mechanism

  19. Mechanism of MnS-mediated pit initiation and propagation in carbon steel in an anaerobic sulfidogenic media

    International Nuclear Information System (INIS)

    Highlights: •In carbon steel, pits are initiated in the immediate surroundings of MnS inclusions. •Unlike stainless steel, MnS inclusions do not dissolve during pit initiation. •The presence of biofilms accelerates pit growth and development. -- Abstract: In a saline anaerobic sulfidogenic environment, pitting on 1018 carbon steel was initiated within a 20–30 nm zone at the MnS inclusion boundary. Nanoscale analysis was performed using scanning electron microscopy and a scanning Auger nanoprobe. The pitting was more pronounced in the presence of a biofilm of sulfate-reducing bacteria than in abiotic sulfide medium. It is proposed that initiation of an anodic reaction leading to dissolution of Fe matrix and subsequent pitting of steel in MnS inclusion boundary regions is due to disorder and strain exerted on the Fe matrix by MnS contamination of the interface from metallurgical processes

  20. Re-racking the Spent Fuel Pit in Nuclear Power Plant Krsko

    International Nuclear Information System (INIS)

    Krsko NPP was designed to temporary store a limited number of spent fuel assemblies (SFA). They were planned to be either removed for reprocessing or permanently stored. The plant will run out of capacity for storing of SFAs in 2003. This means that the plant could not operate further without additional changes since valid regulations require the Spent Fuel Pit (SFP) free storage capacity for the whole emergency core unloading (ECU). The purpose of the SFP Reracking Project is a safe storage of all SFAs in the existing SFP during the plant lifetime. Design solutions and related analysis do not only consider the quantity of spent fuel for the plant lifetime, i.e. up to the year 2023, but also a possibility of the SFP extension for eventually extended plant lifetime of 20 years. According to the planned project, racks shall be designed to provide up to 1694 cells for storage of FAs in Phase I which will be sufficient for normal NPP operation up to its lifetime, i.e. the year 2023. The extension of temporary storage capacity of SFAs in the SFP will be made possible by a combination of existing and new high-density racks. Three modules from the existing 12 will be eliminated, thus leaving 621 cells. There will be nine new racks with up to 1073 super-compacted cells installed in the empty part of the pool. The spacing between new cells will be smaller than the one between existing cells because of special plates, made of borated stainless steel. The design of the racks shall fulfil all the applicable requirements to ensure sub-criticality of all installed SFAs, enriched up to 5 % U 235 with designed peak pallet burnup up to 40 GWD/MTU. Besides static and dynamic seismic loading of both, the racks and the FHB, sufficient cooling of FAs is provided as well as accident conditions precluded. Greater cooling capacity will be achieved by installing the third heat exchanger, connected in parallel to existing two exchangers. The design and manufacturing of the new heat

  1. Inhibition of the ultrasonic microjet-pits on the carbon steel in the particles-water mixtures

    OpenAIRE

    Dayun Yan; Jiadao Wang; Fengbin Liu

    2015-01-01

    In the incubation period of ultrasonic cavitation, due to the impact of microjets on the material surface, the needle-like microjet-pits are formed. Because the formation of microjet-pits relates with the evolution of cavitation erosion on engineering materials, corresponding study will promote the understanding on the mechanism of cavitation erosion. However, little study on the microjet-pits has been carried out, especially in the particles-water mixture. In this study, we firstly demonstra...

  2. Quantitative analysis and development of a computer-aided system for identification of regular pit patterns of colorectal lesions

    OpenAIRE

    Takemura, Yoshito; Yoshida, Shigeto; Tanaka, Shinji; Onji, Keiichi; Oka, Shiro; Tamaki, Toru; Kaneda, Kazufumi; Yoshihara, Masaharu; Chayama, Kazuaki

    2010-01-01

    Background: Because pit pattern classification of colorectal lesions is clinically useful in determining treatment options for colorectal tumors but requires extensive training, we developed a computerized system to automatically quantify and thus classify pit patterns depicted on magnifying endoscopy images.Objective: To evaluate the utility and limitations of our automated pit pattern classification system.Design: Retrospective study.Setting: Department of endoscopy at a university hospital...

  3. Exclusion of erythrocyte-specific membrane proteins from clathrin- coated pits during differentiation of human erythroleukemic cells

    OpenAIRE

    1984-01-01

    When human erythroleukemic cells are induced to differentiate, they produce globin and redistribute glycophorin and spectrin to one pole of the cell. This process was accompanied by an alteration in the clathrin- coated pits at the cell surface. In nondifferentiating cells, receptors for Concanavalin A have been shown, using electron microscopy, to be concentrated into coated pits and rapidly internalized. Glycophorin was also internalized via coated pits, but was not greatly concentrated int...

  4. Prediction of microsegregation and pitting corrosion resistance of austenitic stainless steel welds by modelling

    Energy Technology Data Exchange (ETDEWEB)

    Vilpas, M. [VTT Manufacturing Technology, Espoo (Finland). Materials and Structural Integrity

    1999-07-01

    The present study focuses on the ability of several computer models to accurately predict the solidification, microsegregation and pitting corrosion resistance of austenitic stainless steel weld metals. Emphasis was given to modelling the effect of welding speed on solute redistribution and ultimately to the prediction of weld pitting corrosion resistance. Calculations were experimentally verified by applying autogenous GTA- and laser processes over the welding speed range of 0.1 to 5 m/min for several austenitic stainless steel grades. Analytical and computer aided models were applied and linked together for modelling the solidification behaviour of welds. The combined use of macroscopic and microscopic modelling is a unique feature of this work. This procedure made it possible to demonstrate the effect of weld pool shape and the resulting solidification parameters on microsegregation and pitting corrosion resistance. Microscopic models were also used separately to study the role of welding speed and solidification mode in the development of microsegregation and pitting corrosion resistance. These investigations demonstrate that the macroscopic model can be implemented to predict solidification parameters that agree well with experimentally measured values. The linked macro-micro modelling was also able to accurately predict segregation profiles and CPT-temperatures obtained from experiments. The macro-micro simulations clearly showed the major roles of weld composition and welding speed in determining segregation and pitting corrosion resistance while the effect of weld shape variations remained negligible. The microscopic dendrite tip and interdendritic models were applied to welds with good agreement with measured segregation profiles. Simulations predicted that weld inhomogeneity can be substantially decreased with increasing welding speed resulting in a corresponding improvement in the weld pitting corrosion resistance. In the case of primary austenitic

  5. PRELIMINARY PLANKTON INVESTIGATIONS IN THE GRAVEL PIT AND WINTERPONDS NEAR JAGODNO

    Directory of Open Access Journals (Sweden)

    Marija Tomec

    2007-04-01

    Full Text Available Investigations of plankton populations have been performed in the gravel pit and two winterponds near the place Jagodno, Novo Čiće, in the vicinity of Velika Gorica. Our goal was to examine plankton composition of the gravel pit and winterponds, two ecosystems characterized by specific life–conditions which change with time and space. Investigations were conducted during June 2007. Plankton samples were collected from water surface layer at four locations (two locations in the gravel pit and one location in each of two winterponds. Along with plankton sample collecting, measurements were made of some physico–chemical parameters (water temperature, pH–values and dissolved oxygen content in water. Water temperature at two sampling locations in the gravel pit and one location at each of the winterponds depended on the surrounding air temperature, and ranged from 22.5ºC to 23.6ºC. pH–reaction was alkaline, ranging from 8. 23 to 9. 02. Dissolved oxygen content in the gravel pit was around 10 mg/O2; in winterponds it ranged from 7.6 to 9.7 mg/O2 (Table 1. At the gravel pit locations total number of 32 phytoplankton species were determined; in winterponds were determined 37 (microphytic species? while zooplankton was represented in the phytoplankton community composition at the four locations with 5 species. Phytoplankton species determined in the samples from two gravel pit locations belonged to the system groups Dinophyta, Chrysophyta and Chlorophyta while in the samples from winterpond locations, along with the mentioned system groups, were found as well the representatives from the groups Cyanophyta/Cyanobacteria and Euglenophyta. Zooplankton species belonged to the groups Rotatoria, Cladocera and Copepoda (Table 2. In gravel pit locations dominated diatoms or Bacillarophyceae while in winterponds the majority of phytoplankton mass consisted of the representatives of the species Cyanophyta/Cyanobacteria and Euglenophyta. Qualitative

  6. Historiography, American Theatre, and the First Americans.

    Science.gov (United States)

    Jenkins, Linda Walsh

    American theatre history should include a study of Native American performances, since these performances are rich with "American" symbolic materials such as imagery, symbols, and heraldic visions of animals and landscapes. Indian cultures understood the importance of performance for both the visionary and the community at large. Even the pow-wow…

  7. Nano-pits on GaAs (1 0 0) surface: Preferential sputtering and diffusion

    Science.gov (United States)

    Kumar, Tanuj; Panchal, Vandana; Kumar, Ashish; Kanjilal, D.

    2016-07-01

    Self organized nano-structure array on the surfaces of semiconductors have potential applications in photonics, magnetic devices, photovoltaics, and surface-wetting tailoring etc. Therefore, the control over their dimensions is gaining scientific interest in last couple of decades. In this work, fabrication of pits of nano-dimensions is carried out on the GaAs (1 0 0) surface using 50 keV Ar+ at normal incidence. Variation in fluence from 3 × 1017 ions/cm2 to 5 × 1018 ions/cm2 does not make a remarkable variation in the dimension of pits such as size and depth, which is confirmed by atomic force microscopy (AFM) and scanning electron microscopy (SEM). However the simultaneous dots formation is observed along with the pits at higher fluences. Average size of pits is found to be of 22 nm with depth of 1-5 nm for the used fluences. The importance of preferential sputtering of 'As' as compared to 'Ga' is estimated using energy dispersive X-ray analysis (EDX). The observed alteration in near surface composition shows the Ga enrichment of surface, which is not being much affected by variation in fluence. The growth evolution of pits and dots for the used experimental conditions is explained on the basis of ion beam induced preferential sputtering and surface diffusion.

  8. Adsorption mechanisms of removing heavy metals and dyes from aqueous solution using date pits solid adsorbent

    International Nuclear Information System (INIS)

    A potential usefulness of raw date pits as an inexpensive solid adsorbent for methylene blue (MB), copper ion (Cu2+), and cadmium ion (Cd2+) has been demonstrated in this work. This work was conducted to provide fundamental information from the study of equilibrium adsorption isotherms and to investigate the adsorption mechanisms in the adsorption of MB, Cu2+, and Cd2+ onto raw date pits. The fit of two models, namely Langmuir and Freundlich models, to experimental data obtained from the adsorption isotherms was checked. The adsorption capacities of the raw date pits towards MB and both Cu2+ and Cd2+ ions obtained from Langmuir and Freundlich models were found to be 277.8, 35.9, and 39.5 mg g-1, respectively. Surface functional groups on the raw date pits surface substantially influence the adsorption characteristics of MB, Cu2+, and Cd2+ onto the raw date pits. The Fourier transform infrared spectroscopy (FTIR) studies show clear differences in both absorbances and shapes of the bands and in their locations before and after solute adsorption. Two mechanisms were observed for MB adsorption, hydrogen bonding and electrostatic attraction, while other mechanisms were observed for Cu2+ and Cd2+. For Cu2+, binding two cellulose/lignin units together is the predominant mechanism. For Cd2+, the predominant mechanism is by binding itself using two hydroxyl groups in the cellulose/lignin unit.

  9. NORM levels in Spanish pit lakes and their impact in neighboring environments

    Energy Technology Data Exchange (ETDEWEB)

    Manjon, G.; Galvan, J.A.; Mantero, J.; Diaz, I.; Garcia-Tenorio, R. [University of Seville (Spain)

    2014-07-01

    The Iberian Pyrite Belt (IPB) is a part of the South Zone of the Hercynian Iberian Massif (SW of Iberian Peninsula), being pyrite (FeS{sub 2}) the main mineral associated to this volcano-sedimentary complex. The intensive mining activities in the area, which started in the Roman Empire, have generated mine pits where underground and/or rainwater are stored. These stored waters have produced oxidation of pyrite and, consequently, the pH of pit water has become acid (pH around 2), causing the dissolution of metals and natural radionuclides. The main objective of this work is to show and discuss the levels found for different natural radionuclides (mainly uranium isotopes and daughters via α/γ spectrometry) in water samples and sediments collected from several mine pit lakes located in the south-west of Spain. The waters of the studied pit lakes can interact with the environment, and a fraction can be transferred to surrounding aquifers and even to the main river of the zone (the Odiel River). The waters of this river, when cross the mining area, show low pH values and high concentrations of U-isotopes due to acid mining drainage. Through the analysis of several isotope activity ratios, the presence of natural radionuclides in these pit lakes and its influence in the surrounding area and Odiel river will be additionally evaluated. Document available in abstract form only. (authors)

  10. Pitting corrosion inhibition of aluminum 2024 by Bacillus biofilms secreting polyaspartate or gamma-polyglutamate.

    Science.gov (United States)

    Ornek, D; Jayaraman, A; Syrett, B C; Hsu, C-H; Mansfeld, F B; Wood, T K

    2002-04-01

    Pitting corrosion of aluminum 2024 in Luria Bertani medium was reduced by the secretion of anionic peptides by engineered and natural Bacillus biofilms and was studied in continuous reactors using electrochemical impedance spectroscopy. Compared to sterile controls, pitting was reduced dramatically by the presence of the biofilms. The secretion of a 20 amino acid polyaspartate peptide by an engineered Bacillus subtilis WB600/pBE92-Asp biofilm slightly reduced the corrosion rate of the passive aluminum alloy at pH 6.5; however, the secretion of gamma-polyglutamate by a Bacillus licheniformis biofilm reduced the corrosion rate by 90% (compared to the B. subtilis WB600/pBE92 biofilm which did not secrete polyaspartate or gamma-polyglutamate). The corrosion potential ( E(corr)) of aluminum 2024 was increased by about 0.15-0.44 V due to the formation of B. subtilis and B. licheniformis biofilms as compared to sterile controls. The increase of E(corr) and the observed prevention of pitting indicate that the pitting potential ( E(pit)) had increased. This result and the further decrease of corrosion rates for the passive aluminum alloy suggest that the rate of the anodic metal dissolution reaction was reduced by an inhibitor produced by the biofilms. Purified gamma-polyglutamate also decreased the corrosion rates of aluminum 2024. PMID:11956749

  11. Effects of pH and chloride concentration on pitting corrosion of AA6061 aluminum alloy

    Energy Technology Data Exchange (ETDEWEB)

    Zaid, B. [Division de Technologie du Combustible, Departement de Metallurgie, Centre de Recherche Nucleaire de Draria, BP. 43 Seballa, Draria (Algeria)], E-mail: zaidbachir@yahoo.com; Saidi, D. [Division de Technologie du Combustible, Departement de Metallurgie, Centre de Recherche Nucleaire de Draria, BP. 43 Seballa, Draria (Algeria); Benzaid, A. [Divisionde Physique et Application Nucleaires, Departement Application Nucleaires, Centre de Recherche Nucleaire de Draria, BP. 43 Seballa, Draria (Algeria); Hadji, S. [Division de Technologie du Combustible, Departement du combustible, Centre de Recherche Nucleaire de Draria, BP. 43 Seballa, Draria (Algeria)

    2008-07-15

    Effects of pH solution and chloride (Cl{sup -}) ion concentration on the corrosion behaviour of alloy AA6061 immersed in aqueous solutions of NaCl have been investigated using measurements of weight loss, potentiodynamic polarisation, linear polarisation, cyclic polarisation experiment combined with open circuit potential transient technique and optical or scanning electron microscopy. The corrosion behaviour of the AA6061 aluminum alloy was found to be dependant on the pH and chloride concentration [NaCl] of solution. In acidic or slightly neutral solutions, general and pitting corrosion occurred simultaneously. In contrast, exposure to alkaline solutions results in general corrosion. Experience revealed that the alloy AA6061 was susceptible to pitting corrosion in all chloride solution of concentration ranging between 0.003 wt% and 5.5 wt% NaCl and an increase in the chloride concentration slightly shifted both the pitting E{sub pit} and corrosion E{sub cor} potentials to more active values. In function of the conditions of treatment, the sheets of the alloy AA6061 undergo two types of localised corrosion process, leading to the formation of hemispherical and crystallographic pits. Polarisation resistance measurements in acidic (pH = 2) and alkaline chloride solutions (pH = 12) which are in good agreement with those of weight loss, show that the corrosion kinetic is minimised in slightly neutral solutions (pH = 6)

  12. Herniation pits in the femoral neck: a radiographic indicator of femoroacetabular impingement?

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Ah; Park, Ji Seon; Ryu, Kyungnam [Kyung Hee University, Department of Radiology, Kyung Hee University Medical Center, Seoul (Korea, Republic of); Jin, Wook [Kyung Hee University, Department of Radiology, East-West Neo Medical Center, Seoul (Korea, Republic of)

    2011-02-15

    The purpose was to assess the significance of herniation pits in the femoral neck for radiographic diagnosis of femoroacetabular impingement (FAI). Eighty hips in 62 patients (bilateral in 18) with neutral pelvic orientation were enrolled. Herniation pits were diagnosed when they were located at the anterosuperior femoral neck, close to the physis, and with a diameter of >3 mm. The five radiographic signs of FAI were used: lateral center edge angle (LCE) >39 , acetabular index (AI) {<=}0, extrusion index (EI) <25%, acetabular retroversion, and pistol-grip deformity. Patients with radiographs suggesting FAI were retrospectively correlated with their clinical symptoms. Positive radiographic signs were observed in 7 hips with LCE, 7 with AI, and 80 with EI criteria. Only 3 hips out of 80 (3.8%) showed all of the signs. The acetabular retroversion and pistol-grip deformity were seen in 12/80 and 3/80 hips, respectively. The total number of hips that met radiographic criteria for FAI, including pincer type and cam type, was 18 (23%). However, none of these hips were clinically diagnosed with FAI. All symptomatic hips (11/80) presented only with nonspecific pain, and 2 hips out of 11 showed radiographic signs of FAI. The low frequency of positive radiographic signs suggesting FAI with related symptoms among patients with herniation pits suggests that herniation pits have limited significance in the diagnosis of FAI. Therefore it can be concluded that an incidental finding of herniation pits does not necessarily imply a correlation with FAI. (orig.)

  13. Differential response of pitted morning glory and ivy leaf morning glory to acifluorfen, fomesafen, and lactofen

    International Nuclear Information System (INIS)

    Field and laboratory investigations were conducted to examine the response of soybeans [Glycine max (L.) Merr.], pitted morning glory (Ipomoea lacunosa L.number1 IPOLA), and ivy leaf morning glory [Ipomoea hederacea (L.) Jacq. number IPOHE] to acifluorfen, fomesafen, and lactofen. In field studies, greatest soybean injury was observed with acifluorfen and lactofen. All treatments provided 80% or greater control of pitted morning glory 15 days after treatment. Only acifluorfen and fomesafen at 0.6 kg ai ha-1 provided 80% or greater ivy leaf morning glory. The differential response of pitted morning glory and ivy leaf morning glory to these diphenyl ether herbicides was reflected in soybean seed yields. In laboratory studies, 71 to 84% of applied 14C-acifluorfen was not absorbed into the leaf surface of ivy leaf morning glory. Thirty-two to 46% of applied acifluorfen was recovered from the leaf surface of pitted morning glory. Sixty-four percent of applied 14C-lactofen was recovered from leaf surfaces of both morning glory species 96 h after treatment. Treated leaves of pitted morning glory contained 35 to 37% more 14C-acifluorfen than ivy leaf morning glory. Less than 28% of applied 14C-lactofen was absorbed into treated leaves of both morning glory species at 24, 48, and 96 h harvests

  14. Pit Latrine Emptying Behavior and Demand for Sanitation Services in Dar Es Salaam, Tanzania

    Directory of Open Access Journals (Sweden)

    Marion W. Jenkins

    2015-02-01

    Full Text Available Pit latrines are the main form of sanitation in unplanned areas in many rapidly growing developing cities. Understanding demand for pit latrine fecal sludge management (FSM services in these communities is important for designing demand-responsive sanitation services and policies to improve public health. We examine latrine emptying knowledge, attitudes, behavior, trends and rates of safe/unsafe emptying, and measure demand for a new hygienic latrine emptying service in unplanned communities in Dar Es Salaam (Dar, Tanzania, using data from a cross-sectional survey at 662 residential properties in 35 unplanned sub-wards across Dar, where 97% had pit latrines. A picture emerges of expensive and poor FSM service options for latrine owners, resulting in widespread fecal sludge exposure that is likely to increase unless addressed. Households delay emptying as long as possible, use full pits beyond what is safe, face high costs even for unhygienic emptying, and resort to unsafe practices like ‘flooding out’. We measured strong interest in and willingness to pay (WTP for the new pit emptying service at 96% of residences; 57% were WTP ≥U.S. $17 to remove ≥200 L of sludge. Emerging policy recommendations for safe FSM in unplanned urban communities in Dar and elsewhere are discussed.

  15. Waste assessment radiological characterization of the Weldon Spring Site raffinate pits

    International Nuclear Information System (INIS)

    As part of the remedial investigation efforts conducted at the Weldon Spring Site Remedial Action Project (WSSRAP), it was recognized that an assessment of the nature and extent of the types of waste in the Weldon Spring Raffinate Pits (WSRP) was necessary to evaluate treatment and disposal alternatives. A sampling plan was developed, therefore, which detailed sample locations, sample parameters, and sampling techniques. The sampling effort consisted of collecting 145 samples from 42 locations. The sampling locations were evenly distributed across each of the four raffinate pits in terms of both area and depth. The samples were analyzed for long-lived radionuclides from the natural uranium and natural thorium transformation series. The average, standard deviation, minimum, and maximum were determined for the selected radionuclides for each pit. The data were then evaluated and interpreted specific to each pit and for each radionuclide. At a later date the surface waters of each pit were sampled and similarly analyzed. 11 refs., 8 figs., 18 tabs

  16. NORM levels in Spanish pit lakes and their impact in neighboring environments

    International Nuclear Information System (INIS)

    The Iberian Pyrite Belt (IPB) is a part of the South Zone of the Hercynian Iberian Massif (SW of Iberian Peninsula), being pyrite (FeS2) the main mineral associated to this volcano-sedimentary complex. The intensive mining activities in the area, which started in the Roman Empire, have generated mine pits where underground and/or rainwater are stored. These stored waters have produced oxidation of pyrite and, consequently, the pH of pit water has become acid (pH around 2), causing the dissolution of metals and natural radionuclides. The main objective of this work is to show and discuss the levels found for different natural radionuclides (mainly uranium isotopes and daughters via α/γ spectrometry) in water samples and sediments collected from several mine pit lakes located in the south-west of Spain. The waters of the studied pit lakes can interact with the environment, and a fraction can be transferred to surrounding aquifers and even to the main river of the zone (the Odiel River). The waters of this river, when cross the mining area, show low pH values and high concentrations of U-isotopes due to acid mining drainage. Through the analysis of several isotope activity ratios, the presence of natural radionuclides in these pit lakes and its influence in the surrounding area and Odiel river will be additionally evaluated. Document available in abstract form only. (authors)

  17. Predictive models for determination of pitting corrosion versus inhibitor concentrations and temperature for radioactive sludge in carbon steel waste tanks

    International Nuclear Information System (INIS)

    Statistical models were developed to predict the occurrence of pitting corrosion in carbon steel (CS) waste storage tanks exposed to radioactive nuclear waste. Levels of nitrite (NO2-) concentrations necessary to inhibit pitting at various temperatures and nitrate (NO3-) concentrations were determined experimentally via electrochemical polarization and coupon immersion corrosion tests. Models for the pitting behavior were developed based upon various statistical analyses of the experimental data. Freed-forward, artificial neural network (ANN) models, trained using the back-propagation of error algorithm, more accurately predicted conditions at which pitting occurred than the logistic regression models development using the same data

  18. Microscopic investigation of pitting corrosion in plasma nitrided austenitic stainless steel; Mikroskopische Untersuchung von Lochkorrosion an plasmanitriertem austenitischem rostfreiem Stahl

    Energy Technology Data Exchange (ETDEWEB)

    Escalada, Lisandro; Simison, Silvia N. [Univ. of Mar del Plata (Argentina). Faculty of Engineering; Bruehl, Sonia P. [National Univ. of Technology, Concepcion del Uruguay (Argentina). Surface Engineering Group

    2014-10-01

    UNS 31603 austenitic stainless steel was nitrided using different techniques, and pitting corrosion resistance was analysed in a chloride solution. All nitriding techniques, LEII, PI. and convectional DC nitriding produced a nitrided layer called S phase which is corrosion resistant. Pits morphology and layer structure was investigated using optical and electronic microscopy, SEM-FIB, EDS, and a 3D reconstruction of a pit was assessed using FIB tomography. It was concluded that pits are initiated in MnS inclusions and a channel was generated passing through the nitrided layer, connecting the steel with the electrolyte. Base alloy dissolution was observed beneath the nitrided layer.

  19. Interaction and Cooperative Nucleation of InAsSbP Quantum Dots and Pits on InAs(100 Substrate

    Directory of Open Access Journals (Sweden)

    Gambaryan Karen

    2009-01-01

    Full Text Available Abstract An example of InAsSbP quaternary quantum dots (QDs, pits and dots–pits cooperative structures’ growth on InAs(100 substrates by liquid phase epitaxy (LPE is reported. The interaction and surface morphology of the dots–pits combinations are investigated by the high-resolution scanning electron microscope. Bimodal growth mechanism for the both QDs and pits nucleation is observed. Cooperative structures consist of the QDs banded by pits, as well as the “large” pits banded by the quantum wires are detected. The composition of the islands and the pits edges is found to be quaternary, enriched by antimony and phosphorus, respectively. This repartition is caused by dissociation of the wetting layer, followed by migration (surface diffusion of the Sb and P atoms in opposite directions. The “small” QDs average density ranges from 0.8 to 2 × 109 cm−2, with heights and widths dimensions from 2 to 20 nm and 5 to 45 nm, respectively. The average density of the “small” pits is equal to (6–10 × 109 cm−2 with dimensions of 5–40 nm in width and depth. Lifshits–Slezov-like distribution for the amount and surface density of both “small” QDs and pits versus their average diameter is experimentally detected. A displacement of the absorption edge toward the long wavelength region and enlargement toward the short wavelength region is detected by the Fourier transform infrared spectrometry.

  20. Repair procedure used in removing corroded pits in the distillation towers of the Getulio Vargas Refinery Unit 2100

    Energy Technology Data Exchange (ETDEWEB)

    Lordelos, H.M.; Santin, J.L.

    1977-07-01

    A description is given of the corrosion pits on ASTM A240, Type 405 steel cladded to carbon steel plates used in Petroleo Brasileiro S.A.'s Getulio Vargas Refinery Unit 2100 distillation towers; the repair procedure used, including sand blasting of the corroded surfaces, grinding of the pits, and welding of those pits whose depth was above a maximum limit, and the use of liquid penetrant to check the repairs made; and hydrostatic testing of the T2201 catalytic cracking unit, which used also cladded metals and on which the pits were much smaller in size and number than those on the distillation units.

  1. Effect of boron addition on pitting corrosion resistance of modified 9Cr-1Mo steel: Application of electrochemical noise

    International Nuclear Information System (INIS)

    Highlights: → Weibull probability plots separate pitting and passive corrosion events. → Gumbel distribution analysis gives maximum metastable pit depths. → Addition of boron results in superior pitting corrosion resistance in 0.1 M NaCl. → Incorporation of B into M23C6 carbides refines them and improves pitting resistance. → Coarse M23C6 carbides and delta-ferrite result in inferior pitting resistance. - Abstract: 9Cr-1Mo steels indigenously melted with the addition of boron (Alloy B) and without it (Alloy D) along with Alloy C (without boron addition with minor changes in the trace element concentrations) were studied for their pitting corrosion resistance in 0.001 M, 0.01 M, 0.05 M and 0.1 M sodium chloride solutions using electrochemical noise (EN) technique. Weibull probability plots were used to determine the pit embryo generation rates. Gumbel extreme value analysis was conducted to determine the maximum metastable as well as stable pit radii. The analysis of the data showed superior pitting corrosion resistance of the Alloy B compared to Alloy C as well as Alloy D.

  2. Statistical study by digitalized image analysis of pitting corrosion of an AISI 304 type stainless steel in chloride environment

    International Nuclear Information System (INIS)

    This research thesis addresses the pitting corrosion of an AISI 304-type stainless steel in chloride environment, a phenomenon which is generally considered as comprising two main steps: pit initiation with local degradation of the passive film, and pit growth. By using a technique of analysis of digitalized images, the process is observed in situ and both steps are monitored. A statistical study of the initiation of all the noticed pits is performed. After a bibliographical survey on the pitting corrosion process, its mechanisms and the influence of different parameters, the author presents the studied material and the experimental methods, reports the investigation of the pitting corrosion process in potentiostatic mode over a wide range of potentials in order to study all the types of pits, discusses the influence of potential on pit initiation and growth, reports the study of the influence of hydrodynamic conditions and of ageing in solution on the different parameters, reports the analysis of passive films by photoelectron spectroscopy, and the study of the influence of an inhibitor (molybdate ions) on both steps of pitting corrosion

  3. Ecological condition around the uranium tailing pits in Tajikistan

    International Nuclear Information System (INIS)

    One of the basic sectors of the economy in Tajikistan is the mining industry. Its development in the past led to an accumulation of large amounts of waste mainly associated with the uranium milling facilities. These wastes contain radionuclides in high concentrations (basically uranium- thorium series) and other hazardous substances. These facilities are often located in residential areas and in the upper side of the main watersheds of the region, such as Amu-Daria and Syr-Daria. Tajikistan has a number of uranium ore deposits and mining and milling facilities, which operated in the past. This country's own ores and imported raw materials were processed mainly at the former Leninabad Geochemical Combine facility (currently State Enterprise (SE) 'Vostokredmet') and also at other hydro-metallurgical plants located in the vicinity of uranium ore extraction sites (Adrasman, Taboshar, Isphara etc.). Presently the only operating enterprise in the Republic of Tajikistan, which still has the potential to process Uranium ores, using an acid leach extraction process, is the SE 'Vostokredmet'. It is interesting is to note that the mine wastes at the Adrasman site were recently successfully reprocessed to produce a lead concentrate. Otherwise, all underground and open pit mines and old radium and uranium facilities have been decommissioned, but most of them are still not remediated. Due to the recent significant increase in the price of uranium, the uranium mining residues have become a focus of interest for various different investors and commercial companies who are considering reprocessing the waste rock piles and mill tailings of Northern Tajikistan. Based on estimates from SE 'Vostokredmet', the total amount of residual uranium in the tailings and waste rock piles in the Republic of Tajikistan is about 55 million tons. The total activity of these wastes is estimated to be approximately 240-285 1012 Bq. The total volume of waste rock piles and tailings in the vicinity of

  4. Pitting Corrosion of 316L Stainless Steel under Low Stress below Yield Strength

    Institute of Scientific and Technical Information of China (English)

    L(U) Shengjie; CHENG Xuequn; LI Xiaogang

    2012-01-01

    Pitting corrosion of 316L stainless steel (316L SS) under various stress was studied by potentiodynamic polarization,electrochemical impedance spectroscopy (EIS) and Mott-Schottky (M-S) analysis in 3.5% NaCl solution.The results of polarization curves show that,with the increase of the stress,the pitting potentials and the passive current density markedly decrease firstly (180 MPa),and then increase greatly (200 MPa).The corresponding surface morphologies of the samples after the polarization test well correspond to the results.Mott-Schottky analysis proved the least Cl- adsorbed to the surface of passive film with more positive flat potential,indicating that a moderate stress could increase the pitting corrosion resistance of 316L SS in 3.5% NaCl solution.

  5. Pitting and crevice corrosion behaviour of high alloy stainless steels in chloride-fluoride solutions

    International Nuclear Information System (INIS)

    The localised corrosion resistance (pitting and crevice corrosion) of two high alloy stainless steels, namely superduplex (SD) and superaustenitic (SA), has been studied in chloride-fluoride solutions at pH values ranging from 2 to 6.5. The pitting potential (Epit) and crevice potential (Ecre) have been calculated for these test media using electrochemical techniques (continuous current). The critical pitting temperature (CPT) and critical crevice temperature (CCT) are in both materials lower then the room temperature. In spite of this fact and due to the high repassivation rate, the resistance of these materials to localised corrosion is high in the tested media. At the highest tested concentration of aggressive anions and pH 6.5 both materials undergo a generalised attack. (orig.)

  6. Microstructure and Pitting Corrosion Behavior of Plasma-Sprayed Fe-Si Nanocomposite Coating

    Science.gov (United States)

    Shi, Xi; Meng, Xinjing; Zhong, Qingdong; Yang, Jian; Shu, Mingyong; Han, Hongbo; Bui, QuocBinh

    2016-06-01

    In this study, Fe-Si nanoparticle composite coating (FSN) and Fe-Si microparticle composite coating (FSM) were prepared via atmospheric plasma spraying, and FSN was thermally treated under hydrogen atmosphere at 1120 °C for holding time of 2.5 h (TFSN). Under transmission electron microscopy, many unmelted nanoscale particles were observed in FSN, while no substantial particles were found in TFSN. On scanning electron microscopy analysis, pores and cracks were observed in FSM and FSN, while no defects were found in TFSN. Scanning electrochemical microscopy testing in 3.5 wt.% NaCl for 5 h revealed that FSM underwent severe pitting corrosion, FSN showed relatively minor pitting corrosion, and TFSN had no pitting corrosion.

  7. Determination of the Stable Slope Configuration of Oval-Shaped Furrow Pits

    Institute of Scientific and Technical Information of China (English)

    ZHU Nai-long; ZHANG Shi-xiong

    2004-01-01

    The space effects of oval-shaped furrow pit slopes were analyzed by the elastic mechanics principle. The interaction of limit equilibrium slope angle, friction coefficient, cohesion and horizontal radius of oval-shaped furrow pits has been derived. The oval trumpet-like rock mass is homogeneous and elastic while only loadedby its dead weight. The interaction indicates that the deeper an oval-shaped furrow pit is excavated, the greater thelimit equilibrium slope angle. Both the theory base for reducing stripping waste rock in an oval- shaped furrow pitand the basic way to determine the configuration of a stable slope were developed from the mentioned interaction.The theory includes the preceding principles of stability analysis of slopes. Compared with the configuration deter-mined by traditional theory of slope stability, a great quantity of stripping waste rock can be reduced by that deter-mined in this paper under stable conditions.

  8. Association of Remitting Seronegative Symmetrical Synovitis with Pitting Edema, Polymyalgia Rheumatica, and Adenocarcinoma of the Prostate

    DEFF Research Database (Denmark)

    Emamifar, Amir; Hess, Soeren; Gildberg-Mortensen, Rannveig;

    2016-01-01

    BACKGROUND Remitting seronegative symmetrical synovitis with pitting edema (RS3PE) is a rare condition that occurs in elderly individuals. It can present alone or in association with various rheumatic or malignant diseases. CASE REPORT An 83-year-old man presented with anemia, hyper-sedimentation......BACKGROUND Remitting seronegative symmetrical synovitis with pitting edema (RS3PE) is a rare condition that occurs in elderly individuals. It can present alone or in association with various rheumatic or malignant diseases. CASE REPORT An 83-year-old man presented with anemia, hyper......-sedimentation, and pitting edema of the back of the hands. The patient complained of pain and stiffness of the shoulder and hip girdles, especially in the morning. He was previously diagnosed with adenocarcinoma of the prostate. After 3 years of watchful waiting, treatment with goserelin, a gonadotropin releasing...

  9. Microstructure and Pitting Corrosion Behavior of Plasma-Sprayed Fe-Si Nanocomposite Coating

    Science.gov (United States)

    Shi, Xi; Meng, Xinjing; Zhong, Qingdong; Yang, Jian; Shu, Mingyong; Han, Hongbo; Bui, QuocBinh

    2016-04-01

    In this study, Fe-Si nanoparticle composite coating (FSN) and Fe-Si microparticle composite coating (FSM) were prepared via atmospheric plasma spraying, and FSN was thermally treated under hydrogen atmosphere at 1120 °C for holding time of 2.5 h (TFSN). Under transmission electron microscopy, many unmelted nanoscale particles were observed in FSN, while no substantial particles were found in TFSN. On scanning electron microscopy analysis, pores and cracks were observed in FSM and FSN, while no defects were found in TFSN. Scanning electrochemical microscopy testing in 3.5 wt.% NaCl for 5 h revealed that FSM underwent severe pitting corrosion, FSN showed relatively minor pitting corrosion, and TFSN had no pitting corrosion.

  10. INFLUENCE OF AISI 316Ti STAINLESS STELL SURFACE TREATMENT ON PITTING CORROSION IN VARIOUS SOLUTIONS

    Directory of Open Access Journals (Sweden)

    Pavol Fajnor

    2010-12-01

    Full Text Available Investigation of the surface treatment effect on the resistance of AISI 316Ti stainless steel to pitting corrosion is presented in this paper. The grinded surfaces without additional chemical treatment, grinded and pickled, grinded, pickled and passivated surfaces are tested. The corrosion tests are carried out by exposition in solution which evoke pitting and by electrochemical cyclic potential - sweep method. According to the results the surface treatment has a great influence on the resistance of the tested material to pitting. It is not possible to estimate the best surface treatment because behavior of AISI 316Ti stainless steel with different surface state depends on the mechanism of corrosion processes which vary in the used experimental methods.

  11. Calculation of slope-cover height under price fluctuation in open-pit mines

    Institute of Scientific and Technical Information of China (English)

    Ma Jinyan; Cai Qingxiang; Liu Fuming; Chen Shuzhao

    2014-01-01

    Leaving ditches between adjacent mining areas can effectively reduce re-stripping in the latter mining area and simultaneously lead to an increment in internal dumping costs in the former mining area. This paper establishes calculation models for these two marginal costs. The optimizing model for slope cover height can be determined by including marginal cost models in the objective function. The paper has two main contributions:(a) it fully considers redistribution of dumping space in the model;(b) it introduces price fluctuations and cash discounts in the model. We use the typical open-pit mine as an example to test and prove the model. We conclude that a completely covered slope is reasonable in Haerwusu open pit mine;in addition to an increasing price index, the slope cover height can be reduced;and that price changes are one of the most important influencing factors of slope cover height optimization in an open-pit mine.

  12. Project W-314 241-AN-B valve pit upgrade acceptance for beneficial use

    International Nuclear Information System (INIS)

    This report identifies the responsibilities and requirements, applicable to the 241-AN-B Valve Pit Upgrades portion of Project W-314, for Acceptance for Beneficial Use in accordance with HNF-IP-0842, Vol IV, Sec 3.12. At project turnover, the end user accepts the affected Structures, Systems, and Components (SSCs) for beneficial use. This checklist is used to help the end user ensure that all documentation, training, and testing requirements are met prior to turnover. This checklist specifically identifies those items related to the upgrading of the 241-AN-B valve pit. The upgrades include: the installation of jumper/valve manifolds with position sensors, replacement pit leak detection systems, construction of replacement cover blocks, and electrical upgrades to support the instrumentation upgrades

  13. Project W-314 241-AN-A valve pit upgrade acceptance for beneficial use

    International Nuclear Information System (INIS)

    This report identifies the responsibilities and requirements, applicable to the 241-AN-A Valve Pit Upgrades portion of Project W-314, for Acceptance for Beneficial Use in accordance with HNF-IP-0842, Vol IV, Sec 3.12. At project turnover, the end user accepts the affected Structures, Systems, and Components (SSCs) for beneficial use. This checklist is used to help the end user ensure that all documentation, training, and testing requirements are met prior to turnover. This checklist specifically identifies those items related to the upgrading of the 241-AN-A valve pit. The upgrades include: the installation of jumper/valve manifolds with position sensors, replacement pit leak detection systems, construction of replacement cover blocks, and electrical upgrades to support the instrumentation upgrades

  14. Study on the application of permeable reactive barriers for remediation of uranium mine pit water

    International Nuclear Information System (INIS)

    Permeable reactive barrier (PRB) is economical and convenient on in suit remediation of polluted groundwater. In this paper, according to characteristics of uranium mine pit water, laboratory-scale PRB reactors were designed with the mixture of valent iron, active carbon, hydrated lime and quartz sands as reaction media. The feasibility and effectiveness of treating uranium mine pit water by PRB were tested under 3 different proportions of contaminants through dynamic simulation tests, which came out the optimal proportion of contaminants. The result indicated that the remediation effect of reactor B was the best, whose average removal rate to U was up to 99%. The quality of effluent attained the relevant standards, which indicated that the PRB technology is a feasible method for the treatment of uranium mine pit water. (authors)

  15. Natural radioactivity in lignite samples from open pit mines “Kolubara”, Serbia – risk assessment

    International Nuclear Information System (INIS)

    Coal as fossil fuel mainly contains naturally occurring radionuclides from the uranium and thorium series and 40K. Use of coal, primarily in industry, as a result has dispersion of radioactive material from coal in and through air and water. The aim of this study was to determine the activity concentrations of natural radionuclides in coal samples from open pit mines “Kolubara” and to evaluate its effect on population health. The results showed that all measured and calculated values were below the limits recommended in international legislation. - Highlights: • Activity concentrations of natural radionuclides in coal samples were determined. • Effect on population health due to the activity of these radionuclides was estimated. • All samples were collected at different locations of the open pit mines “Kolubara”. • All measured and calculated values were below the recommended limits. • There is no enhanced radiation hazard for population nearby open pit mines

  16. Hydrodynamic model of the open-pit mine “Buvač” (Republic of Srpska

    Directory of Open Access Journals (Sweden)

    Papić Petar

    2013-09-01

    Full Text Available Projecting of the dewatering system of the open-pit mine “Buvač” (Republic of Srpska, Bosnia and Herzegovina is based on the use of hydrodynamic model of groundwater regime. Creating the hydrodynamic model of the open-pit mine “Buvač“ was made in phases, which began by basic interpretation of collected data, along with schematization of the groundwater flow and flow conditions, and finally, forming and calibration of model. Hydrodynamic model was created as multilayer model with eight layers. Calibration of the hydrodynamic model is the starting point for making prognosis calculation in order to create the most optimal system of open-pit mine protection from groundwater. The results of model calibration indicated that the rivers Gomjenica and Bistrica, precipitation and inflow from karstified rocks are the primary sources of recharge of the limonite ore body “Buvač”.

  17. Alternatives Analysis Amchitka Island Mud Pit Cap Repair, Amchitka, Alaska January 2016

    Energy Technology Data Exchange (ETDEWEB)

    Darr, Paul S. [US Department of Energy, Washington, DC (United States). Office of Legacy Management

    2016-01-01

    The U.S. Department of Energy (DOE) Office of Legacy Management (LM) manages the Nevada Offsites program, which includes a series of reclaimed drilling mud impoundments on Amchitka Island, Alaska (Figure 1). Navarro Research and Engineering, Inc. is the Legacy Management Support contractor (the Contractor) for LM. The Contractor has procured Tetra Tech, Inc. to provide engineering support to the Amchitka mud pit reclamation project. The mud pit caps were damaged during a 7.9-magnitude earthquake that occurred in 2014. The goals of the current project are to investigate conditions at the mud pit impoundments, identify feasible alternatives for repair of the cover systems and the contents, and estimate relative costs of repair alternatives. This report presents descriptions of the sites and past investigations, existing conditions, summaries of various repair/mitigation alternatives, and direct, unburdened, order-of-magnitude (-15% to +50%) associated costs.

  18. Pit and fissure sealants versus fluoride varnishes for preventing dental decay in children and adolescents

    DEFF Research Database (Denmark)

    Hiiri, Anne; Ahovuo-Saloranta, Anneli; Nordblad, Anne;

    2010-01-01

    BACKGROUND: The majority of the detected increment in dental caries among children and adolescents is confined to pit and fissure surfaces of first molars. OBJECTIVES: The objective of this study was to compare the effectiveness of pit and fissure sealants with fluoride varnishes in the prevention......-up found significantly more caries on the fluoride varnished tooth surfaces, compared to sealed plus fluoride varnished surfaces, with a RR of 0.36 (95% CI 0.21 to 0.61). AUTHORS' CONCLUSIONS: There was some evidence on the superiority of pit and fissure sealants over fluoride varnish application in the...... design; sealants versus fluoride varnish or sealants and fluoride varnish combination versus fluoride varnish alone; and subjects under 20 years of age. The primary outcome of interest was the increment in the numbers of carious occlusal surfaces of permanent premolars and molars. DATA COLLECTION AND...

  19. Stationary and transient thermal states of barometric pumping in the access pit of an underground quarry.

    Science.gov (United States)

    Perrier, Frédéric; Le Mouël, Jean-Louis

    2016-04-15

    The transition zone between free and underground atmospheres hosts spectacular phenomena, as demonstrated by temperature measurements performed in the 4.6m diameter and 20m deep vertical access pit of an abandoned underground quarry located in Vincennes, near Paris. In summer, a stable stratification of the atmosphere is maintained, with coherent temperature variations associated with atmospheric pressure changes, with a barometric tide S2 larger than 0.1°C peak to peak. When the winter regime of turbulent cold air avalanches is initiated, stratification with pressure induced signals can be restored transiently in the upper part of the pit, while the lower part remains fully mixed and insensitive to pressure variations. The amplitude of the pressure to temperature transfer function increases with frequency below 5×10(-4)Hz, with values at 3×10(-5)Hz varying from 0.1°C·hPa(-1) at the bottom up to 2°C·hPa(-1) towards the top of the pit. These temperature variations are accounted for by cave breathing, which is pressure induced motion of air amplified by the large volume of the quarry. This understanding is supported by a numerical model including advective heat transport, heat diffusion, and heat exchange with the pit walls. Mean lifetime in the pit is of the order of 9 to 13h, and barometric pumping results in an effective ventilation rate of the quarry of the order of 10(-7)s(-1). This study illustrates the important role of barometric pumping in heat and matter transport between atmosphere and lithosphere. The resulting stationary and transient states, revealed in this pit, are probably a general feature of functioning interface systems, and therefore are an important aspect to consider in problems of contaminant transport, or the preservation of precious heritage such as rare ecosystems or painted caves. PMID:26855357

  20. Illuminating Anaerobic Microbial Community and Cooccurrence Patterns across a Quality Gradient in Chinese Liquor Fermentation Pit Muds.

    Science.gov (United States)

    Hu, Xiaolong; Du, Hai; Ren, Cong; Xu, Yan

    2016-04-15

    Fermentation pit mud, an important reservoir of diverse anaerobic microorganisms, is essential for Chinese strong-aroma liquor production. Pit mud quality, according to its sensory characteristics, can be divided into three grades: degraded, normal, and high quality. However, the relationship between pit mud microbial community and pit mud quality is poorly understood, as are microbial associations within the pit mud ecosystem. Here, microbial communities at these grades were compared using Illumina MiSeq sequencing of the variable region V4 of the 16S rRNA gene. Our results revealed that the pit mud microbial community was correlated with its quality and environmental factors. Species richness, biodiversity, and relative and/or absolute abundances ofClostridia,Clostridium kluyveri,Bacteroidia, andMethanobacteriasignificantly increased, with corresponding increases in levels of pH, NH4 (+), and available phosphorus, from degraded to high-quality pit muds, while levels ofLactobacillus, dissolved organic carbon, and lactate significantly decreased, with normal samples in between. Furthermore, 271 pairs of significant and robust correlations (cooccurrence and negative) were identified from 76 genera using network analysis. Thirteen hubs of cooccurrence patterns, mainly under theClostridia,Bacteroidia,Methanobacteria, andMethanomicrobia, may play important roles in pit mud ecosystem stability, which may be destroyed with rapidly increased levels of lactic acid bacteria (Lactobacillus,Pediococcus, andStreptococcus). This study may help clarify the relationships among microbial community, environmental conditions, and pit mud quality, allow the improvement of pit mud quality by using bioaugmentation and controlling environmental factors, and shed more light on the ecological rules guiding community assembly in pit mud. PMID:26896127