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Sample records for electrically self-heated pit

  1. Extraction of temperature dependent electrical resistivity and thermal conductivity from silicon microwires self-heated to melting temperature

    NASA Astrophysics Data System (ADS)

    Bakan, Gokhan; Adnane, Lhacene; Gokirmak, Ali; Silva, Helena

    2012-09-01

    Temperature-dependent electrical resistivity, ρ(T), and thermal conductivity, k(T), of nanocrystalline silicon microwires self-heated to melt are extracted by matching simulated current-voltage (I-V) characteristics to experimental I-V characteristics. Electrical resistivity is extracted from highly doped p-type wires on silicon dioxide in which the heat losses are predominantly to the substrate and the self-heating depends mainly on ρ(T) of the wires. The extracted ρ(T) decreases from 11.8 mΩ cm at room-temperature to 5.2 mΩ cm at 1690 K, in reasonable agreement with the values measured up to ˜650 K. Electrical resistivity and thermal conductivity are extracted from suspended highly doped n-type silicon wires in which the heat losses are predominantly through the wires. In this case, measured ρ(T) (decreasing from 20.5 mΩ cm at room temperature to 12 mΩ cm at 620 K) is used to extract ρ(T) at higher temperatures (decreasing to 1 mΩ cm at 1690 K) and k(T) (decreasing from 30 W m-1 K-1 at room temperature to 20 W m-1 K-1 at 1690 K). The method is tested by using the extracted parameters to model wires with different dimensions. The experimental and simulated I-V curves for these wires show good agreement up to high voltage and temperature levels. This technique allows extraction of the electrical resistivity and thermal conductivity up to very high temperatures from self-heated microstructures.

  2. Reactive self-heating model of aluminum spherical nanoparticles

    NASA Astrophysics Data System (ADS)

    Martirosyan, Karen S.; Zyskin, M.

    2013-02-01

    Aluminum-oxygen reaction is important in highly energetic and high pressure generating systems. Recent experiments with nanostructured thermites suggest that oxidation of aluminum nanoparticles occurs in a few microseconds. Such rapid reaction cannot be explained by a conventional diffusion-based mechanism. We present a rapid oxidation model of a spherical aluminum nanoparticle, using Cabrera-Mott moving boundary mechanism, and taking self-heating into account. In our model, electric potential solves the nonlinear Poisson equation. In contrast with the Coulomb potential, a "double-layer" type solution for the potential and self-heating leads to enhanced oxidation rates. At maximal reaction temperature of 2000 °C, our model predicts overall oxidation time scale in microseconds range, in agreement with the experimental evidence.

  3. Control of ITBs in Fusion Self-Heated Plasmas

    NASA Astrophysics Data System (ADS)

    Panta, Soma; Newman, David; Terry, Paul; Sanchez, Raul

    2015-11-01

    Simple dynamical models have been able to capture a remarkable amount of the dynamics of the transport barriers found in many devices, including the often disconnected nature of the electron thermal transport channel sometimes observed in the presence of a standard (``ion channel'') barrier. By including in this rich though simple dynamic transport model an evolution equation for electron fluctuations we have previously investigated the interaction between the formation of the standard ion channel barrier and the somewhat less common electron channel barrier. The electron channel formation and evolution is even more sensitive to the alignment of the various gradients making up the sheared radial electric field then the ion barrier is. Because of this sensitivity and coupling of the barrier dynamics, the dynamic evolution of the fusion self-heating profile can have a significant impact on the barrier location and dynamics. To investigate this, self-heating has been added this model and the impact of the self-heating on the formation and controllability of the various barriers is explored. It has been found that the evolution of the heating profiles can suppress or collapse the electron channel barrier. NBI and RF schemes will be investigated for profile/barrier control.

  4. Evaluation of High-Power Solar Electric Propulsion using Advanced Ion, Hall, MPD, and PIT Thrusters for Lunar and Mars Cargo Missions

    NASA Technical Reports Server (NTRS)

    Frisbee, Robert H.

    2006-01-01

    This paper presents the results of mission analyses that expose the advantages and disadvantages of high-power (MWe-class) Solar Electric Propulsion (SEP) for Lunar and Mars Cargo missions that would support human exploration of the Moon and Mars. In these analyses, we consider SEP systems using advanced Ion thrusters (the Xenon [Xe] propellant Herakles), Hall thrusters (the Bismuth [Bi] propellant Very High Isp Thruster with Anode Layer [VHITAL], magnetoplasmadynamic (MPD) thrusters (the Lithium [Li] propellant Advanced Lithium-Fed, Applied-field Lorentz Force Accelerator (ALFA2), and pulsed inductive thruster (PIT) (the Ammonia [NH3] propellant Nuclear-PIT [NuPIT]). The analyses include comparison of the advanced-technology propulsion systems (VHITAL, ALFA2, and NuPIT) relative to state-of-theart Ion (Herakles) propulsion systems and quantify the unique benefits of the various technology options such as high power-per-thruster (and/or high power-per-thruster packaging volume), high specific impulse (Isp), high-efficiency, and tankage mass (e.g., low tankage mass due to the high density of bismuth propellant). This work is based on similar analyses for Nuclear Electric Propulsion (NEP) systems.

  5. Self-heating in piezoresistive cantilevers

    PubMed Central

    Doll, Joseph C.; Corbin, Elise A.; King, William P.; Pruitt, Beth L.

    2011-01-01

    We report experiments and models of self-heating in piezoresistive microcantilevers that show how cantilever measurement resolution depends on the thermal properties of the surrounding fluid. The predicted cantilever temperature rise from a finite difference model is compared with detailed temperature measurements on fabricated devices. Increasing the fluid thermal conductivity allows for lower temperature operation for a given power dissipation, leading to lower force and displacement noise. The force noise in air is 76% greater than in water for the same increase in piezoresistor temperature. PMID:21731884

  6. Localized self-heating in large arrays of 1D nanostructures

    NASA Astrophysics Data System (ADS)

    Monereo, O.; Illera, S.; Varea, A.; Schmidt, M.; Sauerwald, T.; Schütze, A.; Cirera, A.; Prades, J. D.

    2016-02-01

    One dimensional (1D) nanostructures offer a promising path towards highly efficient heating and temperature control in integrated microsystems. The so called self-heating effect can be used to modulate the response of solid state gas sensor devices. In this work, efficient self-heating was found to occur at random networks of nanostructured systems with similar power requirements to highly ordered systems (e.g. individual nanowires, where their thermal efficiency was attributed to the small dimensions of the objects). Infrared thermography and Raman spectroscopy were used to map the temperature profiles of films based on random arrangements of carbon nanofibers during self-heating. Both the techniques demonstrate consistently that heating concentrates in small regions, the here-called ``hot-spots''. On correlating dynamic temperature mapping with electrical measurements, we also observed that these minute hot-spots rule the resistance values observed macroscopically. A physical model of a random network of 1D resistors helped us to explain this observation. The model shows that, for a given random arrangement of 1D nanowires, current spreading through the network ends up defining a set of spots that dominate both the electrical resistance and power dissipation. Such highly localized heating explains the high power savings observed in larger nanostructured systems. This understanding opens a path to design highly efficient self-heating systems, based on random or pseudo-random distributions of 1D nanostructures.One dimensional (1D) nanostructures offer a promising path towards highly efficient heating and temperature control in integrated microsystems. The so called self-heating effect can be used to modulate the response of solid state gas sensor devices. In this work, efficient self-heating was found to occur at random networks of nanostructured systems with similar power requirements to highly ordered systems (e.g. individual nanowires, where their thermal

  7. Evidence of Universal Temperature Scaling in Self-Heated Percolating Networks.

    PubMed

    Das, Suprem R; Mohammed, Amr M S; Maize, Kerry; Sadeque, Sajia; Shakouri, Ali; Janes, David B; Alam, Muhammad A

    2016-05-11

    During routine operation, electrically percolating nanocomposites are subjected to high voltages, leading to spatially heterogeneous current distribution. The heterogeneity implies localized self-heating that may (self-consistently) reroute the percolation pathways and even irreversibly damage the material. In the absence of experiments that can spatially resolve the current distribution and a nonlinear percolation model suitable to interpret them, one relies on empirical rules and safety factors to engineer these materials. In this paper, we use ultrahigh resolution thermo-reflectance imaging, coupled with a new imaging processing technique, to map the spatial distribution ΔT(x, y; I) and histogram f(ΔT) of temperature rise due to self-heating in two types of 2D networks (percolating and copercolating). Remarkably, we find that the self-heating can be described by a simple two-parameter Weibull distribution, even under voltages high enough to reconfigure the percolation pathways. Given the generality of the phenomenological argument supporting the distribution, other percolating networks are likely to show similar stress distribution in response to sufficiently large stimuli. Furthermore, the spatial evolution of the self-heating of network was investigated by analyzing the spatial distribution and spatial correlation, respectively. An estimation of degree of hotspot clustering reveals a mechanism analogous to crystallization physics. The results should encourage nonlinear generalization of percolation models necessary for predictive engineering of nanocomposite materials.

  8. Pitted keratolysis*

    PubMed Central

    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

  9. Correction for Self-Heating When Using Thermometers as Heaters in Precision Control Applications

    NASA Technical Reports Server (NTRS)

    Ressler, Michael E.; Cho, Hyung J.; Sukhatme, Kalyani G.

    2011-01-01

    In precision control applications, thermometers have temperature-dependent electrical resistance with germanium or other semiconductor material thermistors, diodes, metal film and wire, or carbon film resistors. Because resistance readout requires excitation current flowing through the sensor, there is always ohmic heating that leads to a temperature difference between the sensing element and the monitored object. In this work, a thermistor can be operated as a thermometer and a heater, simultaneously, by continuously measuring the excitation current and the corresponding voltage. This work involves a method of temperature readout where the temperature offset due to self-heating is subtracted exactly.

  10. Self-Heating and Failure in Scalable Graphene Devices

    PubMed Central

    Beechem, Thomas E.; Shaffer, Ryan A.; Nogan, John; Ohta, Taisuke; Hamilton, Allister B.; McDonald, Anthony E.; Howell, Stephen W.

    2016-01-01

    Self-heating induced failure of graphene devices synthesized from both chemical vapor deposition (CVD) and epitaxial means is compared using a combination of infrared thermography and Raman imaging. Despite a larger thermal resistance, CVD devices dissipate >3x the amount of power before failure than their epitaxial counterparts. The discrepancy arises due to morphological irregularities implicit to the graphene synthesis method that induce localized heating. Morphology, rather than thermal resistance, therefore dictates power handling limits in graphene devices. PMID:27279020

  11. Self-heating and failure in scalable graphene devices

    DOE PAGES

    Beechem, Thomas E.; Shaffer, Ryan A.; Nogan, John; Ohta, Taisuke; Hamilton, Allister B.; McDonald, Anthony E.; Howell, Stephen W.

    2016-06-09

    Self-heating induced failure of graphene devices synthesized from both chemical vapor deposition (CVD) and epitaxial means is compared using a combination of infrared thermography and Raman imaging. Despite a larger thermal resistance, CVD devices dissipate >3x the amount of power before failure than their epitaxial counterparts. The discrepancy arises due to morphological irregularities implicit to the graphene synthesis method that induce localized heating. As a result, morphology, rather than thermal resistance, therefore dictates power handling limits in graphene devices.

  12. Self-Heating and Failure in Scalable Graphene Devices

    NASA Astrophysics Data System (ADS)

    Beechem, Thomas E.; Shaffer, Ryan A.; Nogan, John; Ohta, Taisuke; Hamilton, Allister B.; McDonald, Anthony E.; Howell, Stephen W.

    2016-06-01

    Self-heating induced failure of graphene devices synthesized from both chemical vapor deposition (CVD) and epitaxial means is compared using a combination of infrared thermography and Raman imaging. Despite a larger thermal resistance, CVD devices dissipate >3x the amount of power before failure than their epitaxial counterparts. The discrepancy arises due to morphological irregularities implicit to the graphene synthesis method that induce localized heating. Morphology, rather than thermal resistance, therefore dictates power handling limits in graphene devices.

  13. Self-Heating and Failure in Scalable Graphene Devices.

    PubMed

    Beechem, Thomas E; Shaffer, Ryan A; Nogan, John; Ohta, Taisuke; Hamilton, Allister B; McDonald, Anthony E; Howell, Stephen W

    2016-01-01

    Self-heating induced failure of graphene devices synthesized from both chemical vapor deposition (CVD) and epitaxial means is compared using a combination of infrared thermography and Raman imaging. Despite a larger thermal resistance, CVD devices dissipate >3x the amount of power before failure than their epitaxial counterparts. The discrepancy arises due to morphological irregularities implicit to the graphene synthesis method that induce localized heating. Morphology, rather than thermal resistance, therefore dictates power handling limits in graphene devices. PMID:27279020

  14. Self-Heating Effects In Polysilicon Source Gated Transistors

    PubMed Central

    Sporea, R. A.; Burridge, T.; Silva, S. R. P.

    2015-01-01

    Source-gated transistors (SGTs) are thin-film devices which rely on a potential barrier at the source to achieve high gain, tolerance to fabrication variability, and low series voltage drop, relevant to a multitude of energy-efficient, large-area, cost effective applications. The current through the reverse-biased source barrier has a potentially high positive temperature coefficient, which may lead to undesirable thermal runaway effects and even device failure through self-heating. Using numerical simulations we show that, even in highly thermally-confined scenarios and at high current levels, self-heating is insufficient to compromise device integrity. Performance is minimally affected through a modest increase in output conductance, which may limit the maximum attainable gain. Measurements on polysilicon devices confirm the simulated results, with even smaller penalties in performance, largely due to improved heat dissipation through metal contacts. We conclude that SGTs can be reliably used for high gain, power efficient analog and digital circuits without significant performance impact due to self-heating. This further demonstrates the robustness of SGTs. PMID:26351099

  15. Experimental Study of Shale Rock Self-Heating

    NASA Astrophysics Data System (ADS)

    Restuccia, Francesco; Ptak, Nicolas; Rein, Guillermo

    2016-04-01

    Self-heating phenomena due to spontaneous exothermic reactions in oxidative environments are common for many porous materials, even at low temperatures. Combustion of shale outcrop formations has been reported in recent years, with self-heating a potential initiating cause. This work studies experimentally and for the first time the self-heating behavior of shale rock, a porous sedimentary rock. Using field samples collected from shale outcrop at Kimmeridge Bay (UK) and the Frank-Kamenetskii theory of criticality, we determine effective kinetic parameters and thermal properties for different shale particle size distributions and upscale the results to field formations of different thicknesses. We show that for fine particle sizes, with diameter below 2mm, spontaneous ignition is possible for rock formations of thickness between 25m and 5.4m at ambient temperatures between 16°C and 44°C. For the same temperature range, the required thickness is between 375km and 15km for coarse particles of diameter below 17mm. This shows that shale rock is reactive, with reactivity highly dependent on particle diameter, and self-ignition is possible for small particles in outcrops or formations accidentally exposed to oxygen.

  16. Self-heating forecasting for thick laminate specimens in fatigue

    NASA Astrophysics Data System (ADS)

    Lahuerta, F.; Westphal, T.; Nijssen, R. P. L.

    2014-12-01

    Thick laminate sections can be found from the tip to the root in most common wind turbine blade designs. Obtaining accurate and reliable design data for thick laminates is subject of investigations, which include experiments on thick laminate coupons. Due to the poor thermal conductivity properties of composites and the material self-heating that occurs during the fatigue loading, high temperature gradients may appear through the laminate thickness. In the case of thick laminates in high load regimes, the core temperature might influence the mechanical properties, leading to premature failures. In the present work a method to forecast the self-heating of thick laminates in fatigue loading is presented. The mechanical loading is related with the laminate self-heating, via the cyclic strain energy and the energy loss ratio. Based on this internal volumetric heat load a thermal model is built and solved to obtain the temperature distribution in the transient state. Based on experimental measurements of the energy loss factor for 10mm thick coupons, the method is described and the resulting predictions are compared with experimental surface temperature measurements on 10 and 30mm UD thick laminate specimens.

  17. Self-Heating Effects In Polysilicon Source Gated Transistors.

    PubMed

    Sporea, R A; Burridge, T; Silva, S R P

    2015-09-09

    Source-gated transistors (SGTs) are thin-film devices which rely on a potential barrier at the source to achieve high gain, tolerance to fabrication variability, and low series voltage drop, relevant to a multitude of energy-efficient, large-area, cost effective applications. The current through the reverse-biased source barrier has a potentially high positive temperature coefficient, which may lead to undesirable thermal runaway effects and even device failure through self-heating. Using numerical simulations we show that, even in highly thermally-confined scenarios and at high current levels, self-heating is insufficient to compromise device integrity. Performance is minimally affected through a modest increase in output conductance, which may limit the maximum attainable gain. Measurements on polysilicon devices confirm the simulated results, with even smaller penalties in performance, largely due to improved heat dissipation through metal contacts. We conclude that SGTs can be reliably used for high gain, power efficient analog and digital circuits without significant performance impact due to self-heating. This further demonstrates the robustness of SGTs.

  18. Self-heating of anaerobic digesters using energy crops.

    PubMed

    Lindorfer, H; Braun, R; Kirchmayr, R

    2006-01-01

    With the increasing application of energy crops in agricultural biogas plants and increasing digester volumes, the phenomenon of self-heating in anaerobic digesters appeared in some cases. Until now this development was just known from aerobic systems. To obtain an idea of the thermodynamics inside an anaerobic digester, a detailed analysis of all heat fluxes in a full-scale agricultural biogas plant was carried out. Several experiments were realised to quantify the influences of different internal and external energy sources. To estimate the impact of self-heating in anaerobic systems, data of other full-scale agricultural biogas plants in Austria were collected. Alternatives to the cooling of the digesters are discussed based on individual experiences of several plants. A connection between carbohydrate-rich substrates, especially with high starch contents, and the self-heating could be shown. From the results it can be assumed that the anaerobic digestion of most energy crops is exothermic, which is in contrast to the current thermodynamic belief.

  19. Self-heating study of an AlGaN/GaN-based heterostructure field effect transistor using ultraviolet micro-Raman scattering.

    SciTech Connect

    Kasisomayajula, V.; Baca, Albert G.; AHMAD, I.; Berg, Jeremy Mark; Holtz, M; Allerman, Andrew Alan; Tigges, Christopher P.; Kurtz, Steven Ross

    2005-01-01

    We report micro-Raman studies of self-heating in an AlGaN/GaN heterostructure field-effect transistor using below (visible 488.0 nm) and near (UV 363.8 nm) GaN band-gap excitation. The shallow penetration depth of the UV light allows us to measure temperature rise ({Delta}T) in the two-dimensional electron gas (2DEG) region of the device between drain and source. Visible light gives the average {Delta}T in the GaN layer, and that of the SiC substrate, at the same lateral position. Combined, we depth profile the self-heating. Measured {Delta}T in the 2DEG is consistently over twice the average GaN-layer value. Electrical and thermal transport properties are simulated. We identify a hotspot, located at the gate edge in the 2DEG, as the prevailing factor in the self-heating.

  20. Self-heating in normal metals and superconductors

    SciTech Connect

    Gurevich, A.V.; Mints, R.G.

    1987-10-01

    This review is devoted to the physics of current-carrying superconductors and normal metals having two or more stable states sustained by Joule self-heating. The creation, propagation, and localization of electrothermal domains and switching waves leading to the transition from one stable state to another in uniform and nonuniform samples are treated in detail. The connection between thermal bistability and hysteresis, dropping and stepped current-voltage characteristics, self-induced oscillations of current and voltage, self-replication of electrothermal domains, and the formation of periodic and stochastic resistive structures are considered.

  1. Optic Nerve Pit

    MedlinePlus

    ... What is the effect of optic pit on vision? The pit itself does not affect vision and most patients remain without any symptoms for decades. About 50% of patients start feeling vision deterioration in their 20’s or 30’s. It is ...

  2. Lithium-ion battery structure that self-heats at low temperatures

    NASA Astrophysics Data System (ADS)

    Wang, Chao-Yang; Zhang, Guangsheng; Ge, Shanhai; Xu, Terrence; Ji, Yan; Yang, Xiao-Guang; Leng, Yongjun

    2016-01-01

    Lithium-ion batteries suffer severe power loss at temperatures below zero degrees Celsius, limiting their use in applications such as electric cars in cold climates and high-altitude drones. The practical consequences of such power loss are the need for larger, more expensive battery packs to perform engine cold cranking, slow charging in cold weather, restricted regenerative braking, and reduction of vehicle cruise range by as much as 40 per cent. Previous attempts to improve the low-temperature performance of lithium-ion batteries have focused on developing additives to improve the low-temperature behaviour of electrolytes, and on externally heating and insulating the cells. Here we report a lithium-ion battery structure, the ‘all-climate battery’ cell, that heats itself up from below zero degrees Celsius without requiring external heating devices or electrolyte additives. The self-heating mechanism creates an electrochemical interface that is favourable for high discharge/charge power. We show that the internal warm-up of such a cell to zero degrees Celsius occurs within 20 seconds at minus 20 degrees Celsius and within 30 seconds at minus 30 degrees Celsius, consuming only 3.8 per cent and 5.5 per cent of cell capacity, respectively. The self-heated all-climate battery cell yields a discharge/regeneration power of 1,061/1,425 watts per kilogram at a 50 per cent state of charge and at minus 30 degrees Celsius, delivering 6.4-12.3 times the power of state-of-the-art lithium-ion cells. We expect the all-climate battery to enable engine stop-start technology capable of saving 5-10 per cent of the fuel for 80 million new vehicles manufactured every year. Given that only a small fraction of the battery energy is used for self-heating, we envisage that the all-climate battery cell may also prove useful for plug-in electric vehicles, robotics and space exploration applications.

  3. Lithium-ion battery structure that self-heats at low temperatures.

    PubMed

    Wang, Chao-Yang; Zhang, Guangsheng; Ge, Shanhai; Xu, Terrence; Ji, Yan; Yang, Xiao-Guang; Leng, Yongjun

    2016-01-28

    Lithium-ion batteries suffer severe power loss at temperatures below zero degrees Celsius, limiting their use in applications such as electric cars in cold climates and high-altitude drones. The practical consequences of such power loss are the need for larger, more expensive battery packs to perform engine cold cranking, slow charging in cold weather, restricted regenerative braking, and reduction of vehicle cruise range by as much as 40 per cent. Previous attempts to improve the low-temperature performance of lithium-ion batteries have focused on developing additives to improve the low-temperature behaviour of electrolytes, and on externally heating and insulating the cells. Here we report a lithium-ion battery structure, the 'all-climate battery' cell, that heats itself up from below zero degrees Celsius without requiring external heating devices or electrolyte additives. The self-heating mechanism creates an electrochemical interface that is favourable for high discharge/charge power. We show that the internal warm-up of such a cell to zero degrees Celsius occurs within 20 seconds at minus 20 degrees Celsius and within 30 seconds at minus 30 degrees Celsius, consuming only 3.8 per cent and 5.5 per cent of cell capacity, respectively. The self-heated all-climate battery cell yields a discharge/regeneration power of 1,061/1,425 watts per kilogram at a 50 per cent state of charge and at minus 30 degrees Celsius, delivering 6.4-12.3 times the power of state-of-the-art lithium-ion cells. We expect the all-climate battery to enable engine stop-start technology capable of saving 5-10 per cent of the fuel for 80 million new vehicles manufactured every year. Given that only a small fraction of the battery energy is used for self-heating, we envisage that the all-climate battery cell may also prove useful for plug-in electric vehicles, robotics and space exploration applications.

  4. Lithium-ion battery structure that self-heats at low temperatures

    NASA Astrophysics Data System (ADS)

    Wang, Chao-Yang; Zhang, Guangsheng; Ge, Shanhai; Xu, Terrence; Ji, Yan; Yang, Xiao-Guang; Leng, Yongjun

    2016-01-01

    Lithium-ion batteries suffer severe power loss at temperatures below zero degrees Celsius, limiting their use in applications such as electric cars in cold climates and high-altitude drones. The practical consequences of such power loss are the need for larger, more expensive battery packs to perform engine cold cranking, slow charging in cold weather, restricted regenerative braking, and reduction of vehicle cruise range by as much as 40 per cent. Previous attempts to improve the low-temperature performance of lithium-ion batteries have focused on developing additives to improve the low-temperature behaviour of electrolytes, and on externally heating and insulating the cells. Here we report a lithium-ion battery structure, the ‘all-climate battery’ cell, that heats itself up from below zero degrees Celsius without requiring external heating devices or electrolyte additives. The self-heating mechanism creates an electrochemical interface that is favourable for high discharge/charge power. We show that the internal warm-up of such a cell to zero degrees Celsius occurs within 20 seconds at minus 20 degrees Celsius and within 30 seconds at minus 30 degrees Celsius, consuming only 3.8 per cent and 5.5 per cent of cell capacity, respectively. The self-heated all-climate battery cell yields a discharge/regeneration power of 1,061/1,425 watts per kilogram at a 50 per cent state of charge and at minus 30 degrees Celsius, delivering 6.4–12.3 times the power of state-of-the-art lithium-ion cells. We expect the all-climate battery to enable engine stop–start technology capable of saving 5–10 per cent of the fuel for 80 million new vehicles manufactured every year. Given that only a small fraction of the battery energy is used for self-heating, we envisage that the all-climate battery cell may also prove useful for plug-in electric vehicles, robotics and space exploration applications.

  5. Lithium-ion battery structure that self-heats at low temperatures.

    PubMed

    Wang, Chao-Yang; Zhang, Guangsheng; Ge, Shanhai; Xu, Terrence; Ji, Yan; Yang, Xiao-Guang; Leng, Yongjun

    2016-01-28

    Lithium-ion batteries suffer severe power loss at temperatures below zero degrees Celsius, limiting their use in applications such as electric cars in cold climates and high-altitude drones. The practical consequences of such power loss are the need for larger, more expensive battery packs to perform engine cold cranking, slow charging in cold weather, restricted regenerative braking, and reduction of vehicle cruise range by as much as 40 per cent. Previous attempts to improve the low-temperature performance of lithium-ion batteries have focused on developing additives to improve the low-temperature behaviour of electrolytes, and on externally heating and insulating the cells. Here we report a lithium-ion battery structure, the 'all-climate battery' cell, that heats itself up from below zero degrees Celsius without requiring external heating devices or electrolyte additives. The self-heating mechanism creates an electrochemical interface that is favourable for high discharge/charge power. We show that the internal warm-up of such a cell to zero degrees Celsius occurs within 20 seconds at minus 20 degrees Celsius and within 30 seconds at minus 30 degrees Celsius, consuming only 3.8 per cent and 5.5 per cent of cell capacity, respectively. The self-heated all-climate battery cell yields a discharge/regeneration power of 1,061/1,425 watts per kilogram at a 50 per cent state of charge and at minus 30 degrees Celsius, delivering 6.4-12.3 times the power of state-of-the-art lithium-ion cells. We expect the all-climate battery to enable engine stop-start technology capable of saving 5-10 per cent of the fuel for 80 million new vehicles manufactured every year. Given that only a small fraction of the battery energy is used for self-heating, we envisage that the all-climate battery cell may also prove useful for plug-in electric vehicles, robotics and space exploration applications. PMID:26789253

  6. Sulci Collapse Pits

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    We will be looking at collapse pits for the next two weeks. Collapse pits on Mars are formed in serveral ways. In volcanic areas, channelized lava flows can form roofs which insulate the flowing lava. These features are termed lava tubes on Earth and are common features in basaltic flows. After the lava has drained, parts of the roof of the tube will collapse under its own weight. These collapse pits will only be as deep as the bottom of the original lava tube. Another type of collapse feature associated with volcanic areas arises when very large eruptions completely evacuate the magma chamber beneath the volcano. The weight of the volcano will cause the entire ediface to subside into the void space below it. Structural features including fractures and graben will form during the subsidence. Many times collapse pits will form within the graben. In addition to volcanic collapse pits, Mars has many collapse pits formed when volatiles (such as subsurface ice) are released from the surface layers. As the volatiles leave, the weight of the surrounding rock causes collapse pits to form.

    These collapse pits are found in an area of 'sulci' ridges east of Olympus Mons. Graben cut the ridges, and one graben hosts the collapse pits. It is likely that these collapse pits are related to volatile release from material that filled the lows at some point after graben formation.

    Image information: VIS instrument. Latitude 18.6, Longitude 234.6 East (125.4 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in

  7. The Chemistry of Self-Heating Food Products: An Activity for Classroom Engagement

    ERIC Educational Resources Information Center

    Oliver-Hoyo, Maria T.; Pinto, Gabriel; Llorens-Molina, Juan Antonio

    2009-01-01

    Two commercial self-heating food products have been used to apply chemical concepts such as stoichiometry, enthalpies of reactions and solutions, and heat transfer in a classroom activity. These products are the self-heating beverages sold in Europe and the Meals, Ready to Eat or MREs used primarily by the military in the United States. The main…

  8. Ascraeus Mons Collapse Pits

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    We will be looking at collapse pits for the next two weeks. Collapse pits on Mars are formed in several ways. In volcanic areas, channelized lava flows can form roofs which insulate the flowing lava. These features are termed lava tubes on Earth and are common features in basaltic flows. After the lava has drained, parts of the roof of the tube will collapse under its own weight. These collapse pits will only be as deep as the bottom of the original lava tube. Another type of collapse feature associated with volcanic areas arises when very large eruptions completely evacuate the magma chamber beneath the volcano. The weight of the volcano will cause the entire edifice to subside into the void space below it. Structural features including fractures and graben will form during the subsidence. Many times collapse pits will form within the graben. In addition to volcanic collapse pits, Mars has many collapse pits formed when volatiles (such as subsurface ice) are released from the surface layers. As the volatiles leave, the weight of the surrounding rock causes collapse pits to form.

    These collapse pits are found on the flank of Ascraeus Mons. The pits and channels are all related to lava tube formation and emptying.

    Image information: IR instrument. Latitude 8, Longitude 253.9 East (106.1 West). 100 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science

  9. Lava Tube Collapse Pits

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    We will be looking at collapse pits for the next two weeks. Collapse pits on Mars are formed in several ways. In volcanic areas, channelized lava flows can form roofs which insulate the flowing lava. These features are termed lava tubes on Earth and are common features in basaltic flows. After the lava has drained, parts of the roof of the tube will collapse under its own weight. These collapse pits will only be as deep as the bottom of the original lava tube. Another type of collapse feature associated with volcanic areas arises when very large eruptions completely evacuate the magma chamber beneath the volcano. The weight of the volcano will cause the entire edifice to subside into the void space below it. Structural features including fractures and graben will form during the subsidence. Many times collapse pits will form within the graben. In addition to volcanic collapse pits, Mars has many collapse pits formed when volatiles (such as subsurface ice) are released from the surface layers. As the volatiles leave, the weight of the surrounding rock causes collapse pits to form.

    These collapse pits are found in the southern hemisphere of Mars. They are likely lava tube collapse pits related to flows from Hadriaca Patera.

    Image information: VIS instrument. Latitude -36.8, Longitude 89.6 East (270.4 West). 19 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space

  10. Open-pit equipment notebook

    SciTech Connect

    Not Available

    1984-12-01

    Beds of consolidated material need to be drilled and blasted before successful excavation. In open-pit mining it is common to move fragmented material across to spoil piles by dragline, shovel, or bucketwheel excavator. One method recently introduced uses explosives to throw much of the overburden across the pit, thus reducing the amount of material needing rehandling. The increased cost of explosives must be balanced with the reduced cost of power needed by the prime excavator. The drill hole pattern and the use of high energy explosives require careful design. Making the choice between hydraulic excavators with a backhoe or front shovel, wheel loaders, and rope-operated shovels continues to be an interesting area of debate. While the rope-operated electric shovel is best for large output, smaller shovels are being replaced by hydraulic excavators for numerous reasons. One of the advantages of hydraulic excavators is that they weigh around half that of rope-operated shovels with the same size bucket. Another advantage is their mobility. They can move at a speed roughly twice that of a rope-operated shovel. Hydraulic excavators can successfully attack a solid face that needs blasting before being loaded by a wheel loader or rope-operated shovel. Neither the rope-operated shovel nor the wheel loader has the wrist-action of the hydraulic excavator. The backhoe's ability to dig below the level on which it is situated and to load trucks that are on the pit floor is important. Recently, many equipment manufacturers have introduced microprocessor-controlled systems for higher power and simpler operation. The choice between wheel loaders and hydraulic excavators should be based on site conditions.

  11. Alba Patera Collapse Pits

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    We will be looking at collapse pits for the next two weeks. Collapse pits on Mars are formed in several ways. In volcanic areas, channelized lava flows can form roofs which insulate the flowing lava. These features are termed lava tubes on Earth and are common features in basaltic flows. After the lava has drained, parts of the roof of the tube will collapse under its own weight. These collapse pits will only be as deep as the bottom of the original lava tube. Another type of collapse feature associated with volcanic areas arises when very large eruptions completely evacuate the magma chamber beneath the volcano. The weight of the volcano will cause the entire edifice to subside into the void space below it. Structural features including fractures and graben will form during the subsidence. Many times collapse pits will form within the graben. In addition to volcanic collapse pits, Mars has many collapse pits formed when volatiles (such as subsurface ice) are released from the surface layers. As the volatiles leave, the weight of the surrounding rock causes collapse pits to form.

    This image of the Alba Patera region has both lava tube collapse pits (running generally east/west) and subsidence related collapse within structural grabens.

    Image information: IR instrument. Latitude 26.9, Longitude 256.5 East (103.5 West). 100 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA

  12. Sulci Collapse Pits

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    We will be looking at collapse pits for the next two weeks. Collapse pits on Mars are formed in several ways. In volcanic areas, channelized lava flows can form roofs which insulate the flowing lava. These features are termed lava tubes on Earth and are common features in basaltic flows. After the lava has drained, parts of the roof of the tube will collapse under its own weight. These collapse pits will only be as deep as the bottom of the original lava tube. Another type of collapse feature associated with volcanic areas arises when very large eruptions completely evacuate the magma chamber beneath the volcano. The weight of the volcano will cause the entire edifice to subside into the void space below it. Structural features including fractures and graben will form during the subsidence. Many times collapse pits will form within the graben. In addition to volcanic collapse pits, Mars has many collapse pits formed when volatiles (such as subsurface ice) are released from the surface layers. As the volatiles leave, the weight of the surrounding rock causes collapse pits to form.

    This is the Noctis Labyrinthus region of Mars. These collapse pits are forming along structural fractures that are allowing the release of volatiles from the subsurface. This is believed to be the way that chaos terrain forms on Mars. This area represents the early stage of chaos formation.

    Image information: VIS instrument. Latitude -12.6, Longitude 264 East (96 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in

  13. Tharsis Collapse Pits

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    We will be looking at collapse pits for the next two weeks. Collapse pits on Mars are formed in several ways. In volcanic areas, channelized lava flows can form roofs which insulate the flowing lava. These features are termed lava tubes on Earth and are common features in basaltic flows. After the lava has drained, parts of the roof of the tube will collapse under its own weight. These collapse pits will only be as deep as the bottom of the original lava tube. Another type of collapse feature associated with volcanic areas arises when very large eruptions completely evacuate the magma chamber beneath the volcano. The weight of the volcano will cause the entire edifice to subside into the void space below it. Structural features including fractures and graben will form during the subsidence. Many times collapse pits will form within the graben. In addition to volcanic collapse pits, Mars has many collapse pits formed when volatiles (such as subsurface ice) are released from the surface layers. As the volatiles leave, the weight of the surrounding rock causes collapse pits to form.

    These collapse pits are found within the extensive lava flows of the Tharsis region. They are related to lava tubes, likely coming from Ascraeus Mons.

    Image information: VIS instrument. Latitude 22.8, Longitude 266.8 East (93.2 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office

  14. Alba Patera Collapse Pits

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    We will be looking at collapse pits for the next two weeks. Collapse pits on Mars are formed in several ways. In volcanic areas, channelized lava flows can form roofs which insulate the flowing lava. These features are termed lava tubes on Earth and are common features in basaltic flows. After the lava has drained, parts of the roof of the tube will collapse under its own weight. These collapse pits will only be as deep as the bottom of the original lava tube. Another type of collapse feature associated with volcanic areas arises when very large eruptions completely evacuate the magma chamber beneath the volcano. The weight of the volcano will cause the entire edifice to subside into the void space below it. Structural features including fractures and graben will form during the subsidence. Many times collapse pits will form within the graben. In addition to volcanic collapse pits, Mars has many collapse pits formed when volatiles (such as subsurface ice) are released from the surface layers. As the volatiles leave, the weight of the surrounding rock causes collapse pits to form.

    These collapse pits are found within graben surrounding Alba Patera. Alba Patera is an old volcano that has subsided after it's magma chamber was evacuated.

    Image information: VIS instrument. Latitude 43.1, Longitude 259.4 East (100.6 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA

  15. Tractus Catena Collapse Pits

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    We will be looking at collapse pits for the next two weeks. Collapse pits on Mars are formed in several ways. In volcanic areas, channelized lava flows can form roofs which insulate the flowing lava. These features are termed lava tubes on Earth and are common features in basaltic flows. After the lava has drained, parts of the roof of the tube will collapse under its own weight. These collapse pits will only be as deep as the bottom of the original lava tube. Another type of collapse feature associated with volcanic areas arises when very large eruptions completely evacuate the magma chamber beneath the volcano. The weight of the volcano will cause the entire edifice to subside into the void space below it. Structural features including fractures and graben will form during the subsidence. Many times collapse pits will form within the graben. In addition to volcanic collapse pits, Mars has many collapse pits formed when volatiles (such as subsurface ice) are released from the surface layers. As the volatiles leave, the weight of the surrounding rock causes collapse pits to form.

    These collapse pits are found in graben located in Tractus Catena. These features are related to subsidence after magma chamber evacuation of Alba Patera.

    Image information: VIS instrument. Latitude 35.8, Longitude 241.7 East (118.3 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA

  16. A self-heating cartridge for molecular diagnostics.

    PubMed

    Liu, Changchun; Mauk, Michael G; Hart, Robert; Qiu, Xianbo; Bau, Haim H

    2011-08-21

    A disposable, water-activated, self-heating, easy-to-use, polymeric cartridge for isothermal nucleic acid amplification and visual fluorescent detection of the amplification products is described. The device is self-contained and does not require any special instruments to operate. The cartridge integrates chemical, water-triggered, exothermic heating with temperature regulation facilitated with a phase-change material (PCM) and isothermal nucleic acid amplification. The water flows into the exothermic reactor by wicking through a porous paper. The porous paper's characteristics control the rate of water supply, which in turn controls the rate of exothermic reaction. The PCM material enables the cartridge to maintain a desired temperature independent of ambient temperatures in the range between 20 °C and 40 °C. The utility of the cartridge is demonstrated by amplifying and detecting Escherichia coli DNA with loop mediated isothermal amplification (LAMP). The device can detect consistently as few as 10 target molecules in the sample. With proper modifications, the cartridge also can work with other isothermal nucleic acid amplification technologies for detecting nucleic acids associated with various pathogens borne in blood, saliva, urine, and other body fluids as well as in water and food. The device is suitable for use at home, in the field, and in poor-resource settings, where access to sophisticated laboratories is impractical, unaffordable, or nonexistent.

  17. Pitting of 3003 aluminum

    SciTech Connect

    Lee, R.

    1996-12-31

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

  18. PIT Coating Requirements Analysis

    SciTech Connect

    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.

  19. Detecting Cavitation Pitting Without Disassembly

    NASA Technical Reports Server (NTRS)

    Barkhoudarian, S.

    1986-01-01

    Technique for detecting cavitation pitting in pumps, turbines, and other machinery uses low-level nuclear irradiation. Isotopes concentrated below surface emit gamma radiation, a portion of which is attenuated by overlying material. Where there are cavitation pits, output of gamma-ray detector fluctuates as detector is scanned near pits. Important to detect cavitation pits because nozzle, turbine blade, or other pump component weakened by cavitation could fail catastrophically and cause machine to explode.

  20. Self-heating study of bulk acoustic wave resonators under high RF power.

    PubMed

    Ivira, Brice; Fillit, René-Yves; Ndagijimana, Fabien; Benech, Philippe; Parat, Guy; Ancey, Pascal

    2008-01-01

    The present work first provides an experimental technique to study self-heating of bulk acoustic wave (BAW) resonators under high RF power in the gigahertz range. This study is specially focused on film bulk acoustic wave resonators and solidly mounted resonators processed onto silicon wafers and designed for wireless systems. Precisely, the reflection coefficient of a one-port device is measured while up to several watts are applied and power leads to electrical drifts of impedances. In the following, we describe how absorbed power can be determined from the incident one in real time. Therefore, an infrared camera held over the radio frequency micro electromechanical system (RF-MEMS) surface with an exceptional spatial resolution reaching up to 2 microm/pixels gives accurate temperature mapping of resonators after emissivity correction. From theoretical point of view, accurate three-dimensional (3-D) structures for finite-element modeling analyses are carried out to know the best materials and architectures to use for enhancing power handling. In both experimental and theoretical investigations, comparison is made between film bulk acoustic wave resonators and solidly mounted resonators. Thus, the trend in term of material, architecture, and size of device for power application such as in transmission path of a transceiver is clearly identified. PMID:18334320

  1. Self-heating study of bulk acoustic wave resonators under high RF power.

    PubMed

    Ivira, Brice; Fillit, René-Yves; Ndagijimana, Fabien; Benech, Philippe; Parat, Guy; Ancey, Pascal

    2008-01-01

    The present work first provides an experimental technique to study self-heating of bulk acoustic wave (BAW) resonators under high RF power in the gigahertz range. This study is specially focused on film bulk acoustic wave resonators and solidly mounted resonators processed onto silicon wafers and designed for wireless systems. Precisely, the reflection coefficient of a one-port device is measured while up to several watts are applied and power leads to electrical drifts of impedances. In the following, we describe how absorbed power can be determined from the incident one in real time. Therefore, an infrared camera held over the radio frequency micro electromechanical system (RF-MEMS) surface with an exceptional spatial resolution reaching up to 2 microm/pixels gives accurate temperature mapping of resonators after emissivity correction. From theoretical point of view, accurate three-dimensional (3-D) structures for finite-element modeling analyses are carried out to know the best materials and architectures to use for enhancing power handling. In both experimental and theoretical investigations, comparison is made between film bulk acoustic wave resonators and solidly mounted resonators. Thus, the trend in term of material, architecture, and size of device for power application such as in transmission path of a transceiver is clearly identified.

  2. Polar Cap Pits

    NASA Technical Reports Server (NTRS)

    2005-01-01

    17 August 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows kidney bean-shaped pits, and other pits, formed by erosion in a landscape of frozen carbon dioxide. This images shows one of about a dozen different patterns that are common in various locations across the martian south polar residual cap, an area that has been receiving intense scrutiny by the MGS MOC this year, because it is visible on every orbit and in daylight for most of 2005.

    Location near: 86.9oS, 6.9oW Image width: width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Spring

  3. Cracked and Pitted Plain

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-536, 6 November 2003

    This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a typical view--at 1.5 meters (5 feet) per pixel--of surfaces in far western Utopia Planitia. In this region, the plains have developed cracks and pit chains arranged in a polygonal pattern. The pits form by collapse along the trend of a previously-formed crack. This picture is located near 45.0oN, 275.4oW. This April 2003 image covers an area 3 km (1.9 mi) wide and is illuminated by sunlight from the lower left.

  4. Ariel's Densely Pitted Surface

    NASA Technical Reports Server (NTRS)

    1986-01-01

    This mosaic of the four highest-resolution images of Ariel represents the most detailed Voyager 2 picture of this satellite of Uranus. The images were taken through the clear filter of Voyager's narrow-angle camera on Jan. 24, 1986, at a distance of about 130,000 kilometers (80,000 miles). Ariel is about 1,200 km (750 mi) in diameter; the resolution here is 2.4 km (1.5 mi). Much of Ariel's surface is densely pitted with craters 5 to 10 km (3 to 6 mi) across. These craters are close to the threshold of detection in this picture. Numerous valleys and fault scarps crisscross the highly pitted terrain. Voyager scientists believe the valleys have formed over down-dropped fault blocks (graben); apparently, extensive faulting has occurred as a result of expansion and stretching of Ariel's crust. The largest fault valleys, near the terminator at right, as well as a smooth region near the center of this image, have been partly filled with deposits that are younger and less heavily cratered than the pitted terrain. Narrow, somewhat sinuous scarps and valleys have been formed, in turn, in these young deposits. It is not yet clear whether these sinuous features have been formed by faulting or by the flow of fluids.

    JPL manages the Voyager project for NASA's Office of Space Science.

  5. Computational design and refinement of self-heating lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Yang, Xiao-Guang; Zhang, Guangsheng; Wang, Chao-Yang

    2016-10-01

    The recently discovered self-heating lithium ion battery has shown rapid self-heating from subzero temperatures and superior power thereafter, delivering a practical solution to poor battery performance at low temperatures. Here, we describe and validate an electrochemical-thermal coupled model developed specifically for computational design and improvement of the self-heating Li-ion battery (SHLB) where nickel foils are embedded in its structure. Predicting internal cell characteristics, such as current, temperature and Li-concentration distributions, the model is used to discover key design factors affecting the time and energy needed for self-heating and to explore advanced cell designs with the highest self-heating efficiency. It is found that ohmic heat generated in the nickel foil accounts for the majority of internal heat generation, resulting in a large internal temperature gradient from the nickel foil toward the outer cell surface. The large through-plane temperature gradient leads to highly non-uniform current distribution, and more importantly, is found to be the decisive factor affecting the heating time and energy consumption. A multi-sheet cell design is thus proposed and demonstrated to substantially minimize the temperature gradient, achieving 30% more rapid self-heating with 27% less energy consumption than those reported in the literature.

  6. Controlling potential barrier height by changing V-shaped pit size and the effect on optical and electrical properties for InGaN/GaN based light-emitting diodes

    SciTech Connect

    Okada, Narihito Kashihara, Hiroyuki; Sugimoto, Kohei; Yamada, Yoichi; Tadatomo, Kazuyuki

    2015-01-14

    The internal quantum efficiency (IQE) of InGaN/GaN multiple quantum wells (MQWs) with blue light emission was improved by inserting an InGaN/GaN superlattice (SL) beneath the MQWs. While the SL technique is useful for improving the light-emitting diode (LED) performance, its effectiveness from a multilateral point of view requires investigation. V-shaped pits (V-pits), which generate a potential barrier and screen the effect of the threading dislocation, are one of the candidates for increasing the light emission efficiency of LEDs exceptionally. In this research, we investigated the relationship between the V-pit and SL and revealed that the V-pit diameter is strongly correlated with the IQE by changing the number of SL periods. Using scanning near-field optical microscopy and photoluminescence measurements, we demonstrated the distinct presence of the potential barrier formed by the V-pits around the dislocations. The relationship between the V-pit and the number of SL periods resulted in changing the potential barrier height, which is related to the V-pit diameter determined by the number of SL periods. In addition, we made an attempt to insert pit expansion layers (PELs) composed of combination of SL and middle temperature grown GaN layer instead of only SL structure. As a result of the evaluation of LEDs using SL or PEL, the EL intensity was strongly related to pit diameter regardless of the structures to form the V-pits. In addition, it was clear that larger V-pits reduce the efficiency droop, which is considered to be suppression of the carrier loss at high injection current.

  7. Controlling potential barrier height by changing V-shaped pit size and the effect on optical and electrical properties for InGaN/GaN based light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Okada, Narihito; Kashihara, Hiroyuki; Sugimoto, Kohei; Yamada, Yoichi; Tadatomo, Kazuyuki

    2015-01-01

    The internal quantum efficiency (IQE) of InGaN/GaN multiple quantum wells (MQWs) with blue light emission was improved by inserting an InGaN/GaN superlattice (SL) beneath the MQWs. While the SL technique is useful for improving the light-emitting diode (LED) performance, its effectiveness from a multilateral point of view requires investigation. V-shaped pits (V-pits), which generate a potential barrier and screen the effect of the threading dislocation, are one of the candidates for increasing the light emission efficiency of LEDs exceptionally. In this research, we investigated the relationship between the V-pit and SL and revealed that the V-pit diameter is strongly correlated with the IQE by changing the number of SL periods. Using scanning near-field optical microscopy and photoluminescence measurements, we demonstrated the distinct presence of the potential barrier formed by the V-pits around the dislocations. The relationship between the V-pit and the number of SL periods resulted in changing the potential barrier height, which is related to the V-pit diameter determined by the number of SL periods. In addition, we made an attempt to insert pit expansion layers (PELs) composed of combination of SL and middle temperature grown GaN layer instead of only SL structure. As a result of the evaluation of LEDs using SL or PEL, the EL intensity was strongly related to pit diameter regardless of the structures to form the V-pits. In addition, it was clear that larger V-pits reduce the efficiency droop, which is considered to be suppression of the carrier loss at high injection current.

  8. Open-pit explosives

    SciTech Connect

    Dannenberg, J.

    1982-07-01

    This paper explains how mine operators are taking a closer look at the power of explosives and how primary breakage affects other open-pit mining costs. Slurries have overcome most of the disadvantages attributed to them in their early years and may replace Anfo. Effective blasting is the key to an efficient, low-cost mining operation. Reviews are presented on research in crater studies, computer-aided design, the expanding gas theory, and high-speed motion picture cameras that show the importance of shock energy in fracturing the rock interfaces throughout the burden. The paper concludes with MSHA-approved courses in blasting offered throughout the US.

  9. Present a new type of self-heating composite based on carbon nanotubes paper and investigate the feasibility in deicing (presentation video)

    NASA Astrophysics Data System (ADS)

    Chu, Hetao; Zhang, Zhichun; Liu, Yanju; Leng, Jinsong

    2014-04-01

    In this paper, a novel self-heating composite material utilizing carbon nanotubes (CNTs) paper is designed and fabricated successfully. The carbon nanotube paper was prepared by multiple steps of CNTs dispersion and suspension filtration as shown in Fig1. a and characterized by scanning electron microscopy thermo gravimetric analysis nitrogen adsorption isotherms at 77K and so on. The surface of the as-prepared CNTs paper is smooth and very flexible. The conductivity of the CNTs paper could be regulated from 30 S/cm to 200 S/cm. The fabricating process of the self-heating is shown in Fig.1 b and the electric heating performance under different ambient temperature, power changing from 4.3W to 44.8W and wind speed ranging from 8m/s to 14m/s was discussed. In addition, the feasibility of the application in the deicing of the composite was simulated by the software of Fluent. The thermal behavior was discussed combining the experimental and simulated values, especially the temperature field distribution under different wind speed. The maximum heating rate can reach 2℃/s under different condition. The equilibrium temperature and energy consumption of the composite at different power compared with the commercial kanthal electric heating film were also investigated. The energy consumption of the self-heating material is less than the kanthal electric heating film to reach the same equilibrium temperature which may be caused by the difference of heat capacity. The experimental and simulated results indicate the electric heating performance of CNTs paper-based composite is superior to the commercial kanthal electric heating film and has feasibility in the field of deicing.

  10. 13. DETAIL WEST OF TURBINE PIT SHOWING PIT DRAINED AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. DETAIL WEST OF TURBINE PIT SHOWING PIT DRAINED AND TURBINE EXPOSED. ORIGINAL WATER LEVEL SHOWN BY LINE JUST ABOVE ARCHED OPENING TO LEFT. WATER LINE AFTER 1982 INSTALLATION OF FLASH BOARDS REVEALED BY DARK STAIN. - Middle Creek Hydroelectric Dam, On Middle Creek, West of U.S. Route 15, 3 miles South of Selinsgrove, Selinsgrove, Snyder County, PA

  11. Ultimate open pit stochastic optimization

    NASA Astrophysics Data System (ADS)

    Marcotte, Denis; Caron, Josiane

    2013-02-01

    Classical open pit optimization (maximum closure problem) is made on block estimates, without directly considering the block grades uncertainty. We propose an alternative approach of stochastic optimization. The stochastic optimization is taken as the optimal pit computed on the block expected profits, rather than expected grades, computed from a series of conditional simulations. The stochastic optimization generates, by construction, larger ore and waste tonnages than the classical optimization. Contrary to the classical approach, the stochastic optimization is conditionally unbiased for the realized profit given the predicted profit. A series of simulated deposits with different variograms are used to compare the stochastic approach, the classical approach and the simulated approach that maximizes expected profit among simulated designs. Profits obtained with the stochastic optimization are generally larger than the classical or simulated pit. The main factor controlling the relative gain of stochastic optimization compared to classical approach and simulated pit is shown to be the information level as measured by the boreholes spacing/range ratio. The relative gains of the stochastic approach over the classical approach increase with the treatment costs but decrease with mining costs. The relative gains of the stochastic approach over the simulated pit approach increase both with the treatment and mining costs. At early stages of an open pit project, when uncertainty is large, the stochastic optimization approach appears preferable to the classical approach or the simulated pit approach for fair comparison of the values of alternative projects and for the initial design and planning of the open pit.

  12. Flyover Modeling of Planetary Pits

    NASA Astrophysics Data System (ADS)

    Balakumar, A.; Bhasin, N.; Daids, O.; Shanor, R.; Snyder, K.; Whittaker, W.

    2015-10-01

    This research uses vision, inertial, and LIDAR sensors to build a high resolution model of a planetary pit as a landing vehicle flies overhead. Pits allow access to subterranean caves, but cannot be fully observed from orbit due to their geometry.

  13. Self-heated silicon nanowires for high performance hydrogen gas detection.

    PubMed

    Ahn, Jae-Hyuk; Yun, Jeonghoon; Moon, Dong-Il; Choi, Yang-Kyu; Park, Inkyu

    2015-03-01

    Self-heated silicon nanowire sensors for high-performance, ultralow-power hydrogen detection have been developed. A top-down nanofabrication method based on well-established semiconductor manufacturing technology was utilized to fabricate silicon nanowires in wafer scale with high reproducibility and excellent compatibility with electronic readout circuits. Decoration of palladium nanoparticles onto the silicon nanowires enables sensitive and selective detection of hydrogen gas at room temperature. Self-heating of silicon nanowire sensors allows us to enhance response and recovery performances to hydrogen gas, and to reduce the influence of interfering gases such as water vapor and carbon monoxide. A short-pulsed heating during recovery was found to be effective for additional reduction of operation power as well as recovery characteristics. This self-heated silicon nanowire gas sensor will be suitable for ultralow-power applications such as mobile telecommunication devices and wireless sensing nodes.

  14. PIT Tagging Anurans

    USGS Publications Warehouse

    McCreary, Brome

    2008-01-01

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

  15. Analytical model for self-heating in nanowire geometries

    NASA Astrophysics Data System (ADS)

    Hunley, D. Patrick; Johnson, Stephen L.; Flores, Roel L.; Sundararajan, Abhishek; Strachan, Douglas R.

    2013-06-01

    An analytical closed form diffusive model is developed of Joule heating in a device consisting of a nanowire connected to two contacts on a substrate. This analytical model is compared to finite-element simulations and demonstrates excellent agreement over a wider range of system parameters in comparison to other recent models, with particularly large improvements in cases when the width of the nanowire is less than the thermal healing length of the contacts and when the thermal resistance of the contact is appreciable relative to the thermal resistance of the nanowire. The success of this model is due to more accurately accounting for the heat spreading within the contact region of a device and below the nanowire into a substrate. The heat spreading is achieved by matching the linear heat flow near the nanowire interfaces with a radially symmetric spreading solution through an interpolation function. Additional features of this model are the ability to incorporate contact resistances that may be present at the nanowire-contact interfaces, as well as accommodating materials with a linear temperature-dependent electrical resistivity.

  16. Self-heating of dried industrial wastewater sludge: lab-scale investigation of supporting conditions.

    PubMed

    Della Zassa, M; Biasin, A; Zerlottin, M; Refosco, D; Canu, P

    2013-06-01

    We studied the reactivity of dried sludge produced by treatment of wastewater, mainly from tanneries. The solids transformations have been first characterized with thermal analysis (TGA and DSC) proving that exothermic transformation takes place at fairly low temperature, before the total organic combustion that occurs in air above 400°C. The onset of low temperature reactions depends on the heating rate and it can be below 100°C at very small heating rate. Then, we reproducibly determined the conditions to trigger dried sludge self-heating at the laboratory scale, on samples in the 0.2-0.3 kg size. Thermal insulation, some aeration and addition of water are key factors. Mastering the self-heating at this scale allows more detailed investigations as well as manipulation of conditions, to understand its nature, course and remediation. Here we report proves and discussions on the role of air, water, particle size, porosity and biological activity, as well as proving that also dried sludge from similar sources lead to self-heating. Tests demonstrate that air and water are simultaneously required for significant self-heating to occur. They act in diverging directions, both triggering the onset of the reactions and damping the temperature rise, by supporting heat loss. The higher the O2 concentration, the higher the solids heating rate. More added water prolongs the exothermic phase. Further additions of water can reactivate the material. Water emphasizes the exothermic processes, but it is not sufficient to start it in an air-free atmosphere. The initial solid moisture concentration (between 8% and 15%) affects the onset of self-heating as intuitive. The sludge particles size strongly determines the strength and extent of the heat release, indicating that surface reactions are taking place. In pelletized particles, limitations to water and air permeability mitigates the reaction course.

  17. Comet 67P's Pitted Surface

    NASA Astrophysics Data System (ADS)

    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

  18. 30. (Credit JTL) Old 19111912 low service pump pit and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    30. (Credit JTL) Old 1911-1912 low service pump pit and receiving well in background. Platform and well in foreground constructed in 1977 for #6 and #7 electric low service pumps (#6 pump moved from old receiving well; #7 installed new). - McNeil Street Pumping Station, McNeil Street & Cross Bayou, Shreveport, Caddo Parish, LA

  19. Tunneling Atomic Force Microscopy Studies on Surface Growth Pits Due to Dislocations in 4H-SiC Epitaxial Layers

    NASA Astrophysics Data System (ADS)

    Ohtani, Noboru; Ushio, Shoji; Kaneko, Tadaaki; Aigo, Takashi; Katsuno, Masakazu; Fujimoto, Tatsuo; Ohashi, Wataru

    2012-08-01

    The morphological and electrical properties of surface growth pits caused by dislocations in 4H-SiC epitaxial layers were characterized using tunneling atomic force microscopy. The characteristic distribution of the tip current between the metal-coated atomic force microscopy tip and the SiC was observed within a large surface growth pit caused by a threading screw dislocation. The current was highly localized inside the pit and occurred only on the inclined surface in the up-step direction near the pit bottom. This paper discusses the causes and possible mechanisms of the observed tip current distribution inside surface growth pits.

  20. Collapse Pits in Bernard Crater

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    We will be looking at collapse pits for the next two weeks. Collapse pits on Mars are formed in serveral ways. In volcanic areas, channelized lava flows can form roofs which insulate the flowing lava. These features are termed lava tubes on Earth and are common features in basaltic flows. After the lava has drained, parts of the roof of the tube will collapse under its own weight. These collapse pits will only be as deep as the bottom of the original lava tube. Another type of collapse feature associated with volcanic areas arises when very large eruptions completely evacuate the magma chamber beneath the volcano. The weight of the volcano will cause the entire ediface to subside into the void space below it. Structural features including fractures and graben will form during the subsidence. Many times collapse pits will form within the graben. In addition to volcanic collapse pits, Mars has many collapse pits formed when volatiles (such as subsurface ice) are released from the surface layers. As the volatiles leave, the weight of the surrounding rock causes collapse pits to form.

    These pits occur in the floor of Bernard Crater. These collapse pits were likely formed by the release of volatiles from the materials deposited in the crater floor.

    Image information: VIS instrument. Latitude -24, Longitude 205.5 East (154.5 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission

  1. A novel partial SOI LDMOSFET with periodic buried oxide for breakdown voltage and self heating effect enhancement

    NASA Astrophysics Data System (ADS)

    Jamali Mahabadi, S. E.; Rajabi, Saba; Loiacono, Julian

    2015-09-01

    In this paper a partial silicon on insulator (PSOI) lateral double diffused metal oxide semiconductor field effect transistor (LDMOSFET) with periodic buried oxide layer (PBO) for enhancing breakdown voltage (BV) and self-heating effects (SHEs) is proposed for the first time. This new structure is called periodic buried oxide partial silicon on insulator (PBO-PSOI). In this structure, periodic small pieces of SiO2 were used as the buried oxide (BOX) layer in PSOI to modulate the electric field in the structure. It was demonstrated that the electric field is distributed more evenly by producing additional electric field peaks, which decrease the common peaks near the drain and gate junctions in the PBO-PSOI structure. Hence, the area underneath the electric field curve increases which leads to higher breakdown voltage. Also a p-type Si window was introduced in the source side to force the substrate to share the vertical voltage drop, leading to a higher vertical BV. Furthermore, the Si window under the source and those between periodic pieces of SiO2 create parallel conduction paths between the active layer and substrate thereby alleviating the SHEs. Simulations with the two dimensional ATLAS device simulator from the Silvaco suite of simulation tools show that the BV of PBO-PSOI is 100% higher than that of the conventional partial SOI (C-PSOI) structure. Furthermore the PBO-PSOI structure alleviates SHEs to a greater extent than its C-PSOI counterpart. The achieved drain current for the PBO-PSOI structure (100 μA), at drain-source voltage of VDS = 100 V and gate-source voltage of VGS = 25 V, is shown to be significantly larger than that in C-PSOI and fully depleted SOI (FD-SOI) structures (87 μA and 51 μA respectively). Drain current can be further improved at the expense of BV by increasing the doping of the drift region.

  2. Efficient Fabrication of Intrinsic-Josephson-Junction Terahertz Oscillators with Greatly Reduced Self-Heating Effects

    NASA Astrophysics Data System (ADS)

    Kashiwagi, T.; Yamamoto, T.; Minami, H.; Tsujimoto, M.; Yoshizaki, R.; Delfanazari, K.; Kitamura, T.; Watanabe, C.; Nakade, K.; Yasui, T.; Asanuma, K.; Saiwai, Y.; Shibano, Y.; Enomoto, T.; Kubo, H.; Sakamoto, K.; Katsuragawa, T.; Marković, B.; Mirković, J.; Klemm, R. A.; Kadowaki, K.

    2015-11-01

    The intrinsic Josephson junctions (IJJs) in the high-Tc superconductor Bi2Sr2CaCu2O8 +δ (Bi2212) are shown to have great potential for the construction of an oscillator emitting in the terahertz-frequency f regime. However, earlier devices with Bi2212 substrates exhibit strong self-heating effects detrimental to their operation and limiting the maximum f to approximately 1 THz. Here we describe an efficient fabrication procedure for a stand-alone-mesa IJJ terahertz oscillator with considerably reduced self-heating effects, greatly expanding the tunability and maximum value of f , potentially even to 15 THz. Their typical current-voltage characteristics, radiation tunability and power, and some practical uses are also presented.

  3. Self-heating induced instability of oxide thin film transistors under dynamic stress

    NASA Astrophysics Data System (ADS)

    Kise, Kahori; Fujii, Mami N.; Urakawa, Satoshi; Yamazaki, Haruka; Kawashima, Emi; Tomai, Shigekazu; Yano, Koki; Wang, Dapeng; Furuta, Mamoru; Ishikawa, Yasuaki; Uraoka, Yukiharu

    2016-01-01

    Degradation caused by Joule heating of transparent amorphous oxide semiconductor thin-film transistors (TFTs) is an important issue for display technology. Deep understanding of the mechanism of self-heating degradation generated by driving pulse voltage will pave the way for the development of highly reliable flexible displays. In this work, by using a pseudo interval measurement method, we examined the relationship of the highest and the lowest heating temperature in pulse 1 cycle and frequency. These self-heating converged to a constant temperature under pulse voltage applied at 1 kHz. Moreover, the long-term reliability under positive-bias stress voltage at 1 kHz of low converged temperature condition was improved relative to that of the stress voltage at 10 Hz of dynamic temperature change condition. We discussed the degradation mechanism of oxide TFTs generated by pulse voltage, and clarified that the degradation was accelerated by thermionic emission which occurred at low frequency.

  4. Breaking of Apricot Pits by Using a Mechanical System

    NASA Astrophysics Data System (ADS)

    Polat, R.; Aktas, T.; Gezer, I.; Atay, U.; Bilim, H. I. C.

    The objective of this research was to investigate the effects of heating process and warping effect on breaking of apricot pits and obtaining of its kernel without damage. For this aim, heating process (350°C) was applied to apricot pits. Heated pits were fallen onto the rotating disc and they were warped to warping wall by centrifuge effect. Warping velocity was adjusted by changing of rotating disc revolution that was driven by an electric engine. Three different disc revolution namely 400, 500 and 600 min-1 and 4 different moisture contents of apricot pits namely 6.7, 15.5, 22.2 and 31.5% were used in the experiments. As a result, it was found that increasing of moisture content was increased amount of breaking and also sound kernel ratio. Increasing of disc revolution increased ratio of damaged kernel. The highest breaking amount was determined for experiment with heated pits that had 31.5% moisture content and warped with 400 min-1 disk revolution.

  5. Numerical Simulation of Temperature Sensor Self-Heating Effects in Gaseous and Liquid Hydrogen Under Cryogenic Conditions

    NASA Astrophysics Data System (ADS)

    Langebach, R.; Haberstroh, Ch.

    2010-04-01

    In this paper a numerical investigation is presented that characterizes the free convective flow field and the resulting heat transfer mechanisms for a resistance temperature sensor in liquid and gaseous hydrogen at various cryogenic conditions. Motivation for this is the detection of stratification effects e.g. inside a liquid hydrogen storage vessel. In this case, the local temperature measurement in still resting fluid requires a very high standard of precision despite an extremely poor thermal anchoring of the sensor. Due to electrical power dissipation a certain amount of heat has to be transferred from sensor to fluid. This can cause relevant measurement errors due to a slightly elevated sensor temperature. A commercial CFD code was employed to calculate the heat and mass transfer around the typical sensor geometry. The results were compared with existing heat transfer correlations from the literature. As a result the magnitude of averaged heat transfer coefficients and sensor over-heating as a function of power dissipation are given in figures. From the gained numerical results a new correlation for the averaged Nusselt Number is presented that represents very low Rayleigh Number flows. The correlation can be used to estimate sensor self-heating effects in similar situations.

  6. INTERACTIVE PIT LAKES 2004 CONFERENCE

    EPA Science Inventory

    This CD and the workshop provide a pit lakes forum for the exchange of scientific information on current domestic and international approaches, including arid and wet regions throughout the world. These approaches include characterization, modeling/monitoring, and treatment and r...

  7. Increase of self-heating effects in nanodevices induced by surface roughness: A full-quantum study

    SciTech Connect

    Pala, M. G. Cresti, A.

    2015-02-28

    We present a full-quantum approach to investigate self-heating effects in nanoelectronic devices and exploit it to simulate rough nanowire field-effect transistors. Self-heating is found to significantly contribute (up to about 16%) to the degradation of the transistor performances, with an impact that is stronger for stronger roughness. The mechanism at the origin of the enhanced backscattering is the temperature increase due to the thermal conductivity reduction and the consequent increase of electron-phonon coupling.

  8. Quantitative damage evaluation of localized deep pitting

    SciTech Connect

    Al Beed, A.A.; Al Garni, M.A.

    2000-04-01

    Localized deep pitting is considered difficult to precisely measure and evaluate using simple techniques and daily-use analysis approaches. A case study was made of carbon steel heat exchangers in a typical fresh cooling water environment that experienced severe pitting. To effectively and precisely evaluate the encountered pitting damage, a simple measurement and analyses approach was devised. In this article, the pitting measurement technique and the damage evaluation approach are presented and discussed in detail.

  9. NIR detection of pits and pit fragments in fresh cherries (abstract)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The feasibility of using near infrared (NIR) diffuse reflectance spectroscopy for the detection of pits and pit fragments in cherries was demonstrated. For detection of whole pits, 300 cherries were obtained locally and pits were removed from half. NIR reflectance spectra were obtained in triplicate...

  10. Workshop Proceedings: Pitting in Steam Generator Tubing

    SciTech Connect

    1984-10-01

    A two-day workshop focused on the probable causes of steam generator pitting at two nuclear plants and on whether pitting is a low-temperature or a high-temperature phenomenon. Participants also heard descriptions of various pit-resistant metals that are suitable for tube sleeving.

  11. CALL FOR ABSTRACTS - PIT LAKES 2004

    EPA Science Inventory

    This call for abstracts is for the 11/16-18/2004 Pit Lakes 2004 meeting held in Reno, NV. This conference will provide a forum for the exchange of scientific information on current domestic and international pit lake approaches, including pit lakes from arid and wet regions throu...

  12. Experimental investigation of the systematic error on photomechanic methods induced by camera self-heating.

    PubMed

    Ma, Qinwei; Ma, Shaopeng

    2013-03-25

    The systematic error for photomechanic methods caused by self-heating induced image expansion when using a digital camera was systematically studied, and a new physical model to explain the mechanism has been proposed and verified. The experimental results showed that the thermal expansion of the camera outer case and lens mount, instead of mechanical components within the camera, were the main reason for image expansion. The corresponding systematic error for both image analysis and fringe analysis based photomechanic methods were analyzed and measured, then error compensation techniques were proposed and verified.

  13. Influence of anharmonic phonon decay on self-heating in Si nanowire transistors

    SciTech Connect

    Rhyner, Reto Luisier, Mathieu

    2014-08-11

    Anharmonic phonon-phonon scattering is incorporated into an electro-thermal quantum transport approach based on the nonequilibrium Green's function formalism. Electron-phonon and phonon-phonon interactions are taken into account through scattering self-energies solved in the self-consistent Born approximation. While studying self-heating effects in ultra-scaled Si nanowire transistors, it is found that the phonon decay process softens the artificial accumulation of high energy phonons caused by electron relaxations close to the drain region. This leads to an increase of the device current in the ON-state and a reduction of the effective lattice temperature.

  14. Ultra-low power operation of self-heated, suspended carbon nanotube gas sensors

    NASA Astrophysics Data System (ADS)

    Chikkadi, Kiran; Muoth, Matthias; Maiwald, Verena; Roman, Cosmin; Hierold, Christofer

    2013-11-01

    We present a suspended carbon nanotube gas sensor that senses NO2 at ambient temperature and recovers from gas exposure at an extremely low power of 2.9 μW by exploiting the self-heating effect for accelerated gas desorption. The recovery time of 10 min is two orders of magnitude faster than non-heated recovery at ambient temperature. This overcomes an important bottleneck for the practical application of carbon nanotube gas sensors. Furthermore, the method is easy to implement in sensor systems and requires no additional components, paving the way for ultra-low power, compact, and highly sensitive gas sensors.

  15. SELF-HEATING OF CORONA BY ELECTROSTATIC FIELDS DRIVEN BY SHEARED FLOWS

    SciTech Connect

    Saleem, H.; Ali, S.; Poedts, S.

    2012-04-01

    A mechanism for self-heating of the solar corona is discussed. It is shown that the free energy available in the form of sheared flows gives rise to unstable electrostatic perturbations which accelerate and heat particles. The electrostatic perturbations can occur through two processes, viz., by a purely growing sheared flow-driven instability and/or by a sheared flow-driven drift wave. These processes can occur throughout the corona and, hence, this self-heating mechanism could be very important for coronal heating. These instabilities can give rise to local perturbed electrostatic potentials {psi}{sub 1} of up to 100 volts within 3 Multiplication-Sign 10{sup -2} to a few seconds time, if the (dimensionless) initial perturbation is assumed to be about 1%, that is, e{psi}{sub 1}/T{sub e} {approx_equal} 10{sup -2}. The wavelengths in the direction perpendicular to the external magnetic field B{sub 0} vary from about 10 m to 1 m in our model. The purely growing instability creates electrostatic fields by sheared flows even if there is no density gradient, whereas a density gradient is crucial for the occurrence of the drift wave instability. The purely growing instability develops a small real frequency as well in the two-ion coronal plasma. In the solar corona, very low frequency (of the order of 1 Hz) drift dissipative waves can also occur due to electron-ion collisions.

  16. An acoustic/thermal model for self-heating in PMN sonar projectors

    PubMed

    Shankar; Hom

    2000-11-01

    Dielectric hysteresis and a strong material temperature dependence uniquely couple the acoustic output and temperature of a sonar projector driven by electrostrictive Pb(Mg1/3, Nb2/3)O3 (PMN). Both the source level and the source of self-heating, i.e., dielectric hysteresis, dramatically decrease as the PMN driver heats. The final temperature delineates outstanding PMN transducers from mediocre PMN transducers, so accurate acoustic performance prediction requires accurate transducer temperature prediction. This study examined this self-heating phenomenon by combining an electro-acoustics model for a PMN flextensional transducer with a thermal finite element model. The sonar model calculated the source level and heat generation rate for the PMN driver as a function of temperature. This computed source level varied 12 dB over a 75 degrees C temperature range solely due to the temperature dependent ceramic. The heat transfer model used the computed heat rate to predict the transducer's transient thermal response. The results clearly demonstrate that the transducer reached a steady-state equilibrium temperature, where the heat generated by the PMN driver balanced the heat dissipated. While the transducer model predicted a significant temperature rise, the corresponding acoustic output still surpassed the output of an equivalent Pb(Zr,Ti)O3 (PZT) transducer by 8 dB. Good agreement with experiments made on a PMN flextensional transducer validated the model.

  17. Metal-insulator transition upon heating and negative-differential-resistive-switching induced by self-heating in BaCo{sub 0.9}Ni{sub 0.1}S{sub 1.8}

    SciTech Connect

    Fisher, B.; Genossar, J.; Chashka, K. B.; Patlagan, L.; Reisner, G. M.

    2014-04-14

    The layered compound BaCo{sub 1−x}Ni{sub x}S{sub 2−y} (0.05 < x < 0.2 and 0.05 < y < 0.2) exhibits an unusual first-order structural and electronic phase transition from a low-T monoclinic paramagnetic metal to a high-T tetragonal antiferromagnetic insulator around 200 K with huge hysteresis (∼40 K) and large volume change (∼0.01). Here, we report on unusual voltage-controlled resistive switching followed by current-controlled resistive switching induced by self-heating in polycrystalline BaCo{sub 1−x}Ni{sub x}S{sub 2−y} (nominal x = 0.1 and y = 0.2). These were due to the steep metal to insulator transition upon heating followed by the activated behavior of the resistivity above the transition. The major role of Joule heating in switching is supported by the absence of nonlinearity in the current as function of voltage, I(V), obtained in pulsed measurements, in the range of electric fields relevant to d.c. measurements. The voltage-controlled negative differential resistance around the threshold for switching was explained by a simple model of self-heating. The main difficulty in modeling I(V) from the samples resistance as function of temperature R(T) was the progressive increase of R(T), and to a lesser extend the decrease of the resistance jumps at the transitions, caused by the damage induced by cycling through the transitions by heating or self-heating. This was dealt with by following systematically R(T) over many cycles and by using the data of R(T) in the heating cycle closest to that of the self-heating one.

  18. Metal-insulator transition upon heating and negative-differential-resistive-switching induced by self-heating in BaCo0.9Ni0.1S1.8

    NASA Astrophysics Data System (ADS)

    Fisher, B.; Genossar, J.; Chashka, K. B.; Patlagan, L.; Reisner, G. M.

    2014-04-01

    The layered compound BaCo1-xNixS2-y (0.05 < x < 0.2 and 0.05 < y < 0.2) exhibits an unusual first-order structural and electronic phase transition from a low-T monoclinic paramagnetic metal to a high-T tetragonal antiferromagnetic insulator around 200 K with huge hysteresis (˜40 K) and large volume change (˜0.01). Here, we report on unusual voltage-controlled resistive switching followed by current-controlled resistive switching induced by self-heating in polycrystalline BaCo1-xNixS2-y (nominal x = 0.1 and y = 0.2). These were due to the steep metal to insulator transition upon heating followed by the activated behavior of the resistivity above the transition. The major role of Joule heating in switching is supported by the absence of nonlinearity in the current as function of voltage, I(V), obtained in pulsed measurements, in the range of electric fields relevant to d.c. measurements. The voltage-controlled negative differential resistance around the threshold for switching was explained by a simple model of self-heating. The main difficulty in modeling I(V) from the samples resistance as function of temperature R(T) was the progressive increase of R(T), and to a lesser extend the decrease of the resistance jumps at the transitions, caused by the damage induced by cycling through the transitions by heating or self-heating. This was dealt with by following systematically R(T) over many cycles and by using the data of R(T) in the heating cycle closest to that of the self-heating one.

  19. Cause of pitting in beryllium

    SciTech Connect

    Kershaw, R.P.

    1982-04-16

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

  20. Pits and Flutes on Stimpy

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The rock 'Stimpy' is seen in this close-up image taken by the Sojourner rover's left front camera on Sol 70 (September 13). Detailed texture on the rock, such as pits and flutes, are clearly visible.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

  1. Thermal reactive ion etching technique involving use of self-heated cathode.

    PubMed

    Yamada, S; Minami, Y; Sohgawa, M; Abe, T

    2015-04-01

    In this work, the thermal reactive ion etching (TRIE) technique for etching hard-to-etch materials is presented. The TRIE technique employs a self-heated cathode and a thermally insulated aluminum plate is placed on the cathode of a regular reactive ion etching (RIE) system. By optimizing the beam size to support the sample stage, the temperature of the stage can be increased to a desired temperature without a cathode heater. The technique was used to etch a bulk titanium plate. An etch rate of 0.6 μm/min and an etch selectivity to nickel of 100 were achieved with SF6 plasma. The proposed technique makes a regular RIE system a more powerful etcher without the use of chlorine gas, a cathode heater, and an inductively coupled plasma source. PMID:25933887

  2. Thermal conductivity and diffusivity of biomaterials measured with self-heated thermistors

    NASA Astrophysics Data System (ADS)

    Valvano, J. W.; Cochran, J. R.; Diller, K. R.

    1985-05-01

    This paper presents an experimental method to measure the thermal conductivity and thermal diffusivity of biomaterials. Self-heated thermistor probes, inserted into the tissue of interest, are used to deliver heat as well as to monitor the rate of heat removal. An empirical calibration procedure allows accurate thermal-property measurements over a wide range of tissue temperatures. Operation of the instrument in three media with known thermal properties shows the uncertainty of measurements to be about 2%. The reproducibility is 0.5% for the thermal-conductivity measurements and 2% for the thermal-diffusivity measurements. Thermal properties were measured in dog, pig, rabbit, and human tissues. The tissues included kidney, spleen, liver, brain, heart, lung, pancreas, colon cancer, and breast cancer. Thermal properties were measured for 65 separate tissue samples at 3, 10, 17, 23, 30, 37, and 45°C. The results show that the temperature coefficient of biomaterials approximates that of water.

  3. A self-heating 2ω method for Seebeck coefficient measurement of thermoelectric materials.

    PubMed

    Miao, Tingting; Ma, Weigang; Zhang, Xing; Li, Zhen

    2011-02-01

    A novel and reliable self-heating 2ω method has been developed to measure the Seebeck coefficient of the microscale/nanoscale thermoelectric materials. Based on the analytical solution of the transient heat-conduction equation of the specimen heated by a harmonic current, two measurement modes have been developed: (1) the Seebeck coefficient can be directly extracted from the ratio of experimentally measured 2ω Seebeck voltage to theoretically predicted 2ω temperature drop oscillation; and (2) the Seebeck coefficient can be steadily extracted from the measured 2ω and 3ω voltages. This approach has been applied to a 25.4 μm thick K-type thermocouple and the measured Seebeck coefficient corresponds well with the nominal value.

  4. Thermal reactive ion etching technique involving use of self-heated cathode

    NASA Astrophysics Data System (ADS)

    Yamada, S.; Minami, Y.; Sohgawa, M.; Abe, T.

    2015-04-01

    In this work, the thermal reactive ion etching (TRIE) technique for etching hard-to-etch materials is presented. The TRIE technique employs a self-heated cathode and a thermally insulated aluminum plate is placed on the cathode of a regular reactive ion etching (RIE) system. By optimizing the beam size to support the sample stage, the temperature of the stage can be increased to a desired temperature without a cathode heater. The technique was used to etch a bulk titanium plate. An etch rate of 0.6 μm/min and an etch selectivity to nickel of 100 were achieved with SF6 plasma. The proposed technique makes a regular RIE system a more powerful etcher without the use of chlorine gas, a cathode heater, and an inductively coupled plasma source.

  5. Numerical Simulation of the Self-Heating Effect Induced by Electron Beam Plasma in Atmosphere

    NASA Astrophysics Data System (ADS)

    Deng, Yongfeng; Tan, Chang; Han, Xianwei; Tan, Yonghua

    2012-02-01

    For exploiting advantages of electron beam air plasma in some unusual applications, a Monte Carlo (MC) model coupled with heat transfer model is established to simulate the characteristics of electron beam air plasma by considering the self-heating effect. Based on the model, the electron beam induced temperature field and the related plasma properties are investigated. The results indicate that a nonuniform temperature field is formed in the electron beam plasma region and the average temperature is of the order of 600 K. Moreover, much larger volume pear-shaped electron beam plasma is produced in hot state rather than in cold state. The beam ranges can, with beam energies of 75 keV and 80 keV, exceed 1.0 m and 1.2 m in air at pressure of 100 torr, respectively. Finally, a well verified formula is obtained for calculating the range of high energy electron beam in atmosphere.

  6. Numerical dc self-heating in planar double-gate MOSFETs

    NASA Astrophysics Data System (ADS)

    González, B.; Iñiguez, B.; Lázaro, A.; Cerdeira, A.

    2011-09-01

    Self-heating in planar double-gate (DG) MOSFETs is numerically studied under static operating conditions. In order to correctly predict the lattice temperature inside the device and, consequently, the drain current, factors such as the reduction in thermal conductivity of thin films (temperature dependent), the influence of the buried oxide layer, the necessity of a hydrodynamic model and quantization are analysed to evidence their impact on a proper simulation of the dc transistor performance. This paper also shows that DG MOSFETs can be thermally optimized using flare extensions in all terminals and mid-gap gate metals with high thermal conductivity. Moreover, the influence of gate length and channel thickness on the peak temperature rise is studied. Other major technological changes, such as eliminating thin oxide films from channel extensions and using AlN instead of SiO2, are also discussed.

  7. Thermal reactive ion etching technique involving use of self-heated cathode

    SciTech Connect

    Yamada, S.; Minami, Y.; Sohgawa, M.; Abe, T.

    2015-04-15

    In this work, the thermal reactive ion etching (TRIE) technique for etching hard-to-etch materials is presented. The TRIE technique employs a self-heated cathode and a thermally insulated aluminum plate is placed on the cathode of a regular reactive ion etching (RIE) system. By optimizing the beam size to support the sample stage, the temperature of the stage can be increased to a desired temperature without a cathode heater. The technique was used to etch a bulk titanium plate. An etch rate of 0.6 μm/min and an etch selectivity to nickel of 100 were achieved with SF{sub 6} plasma. The proposed technique makes a regular RIE system a more powerful etcher without the use of chlorine gas, a cathode heater, and an inductively coupled plasma source.

  8. Open pit blasting in India

    SciTech Connect

    Wasson, D.A.; Garg, D.D.

    1995-12-31

    Open pit blasting in India uses two types of explosives. First there are bulk explosives for wet and dry holes, and there are packaged explosives. The Indian open pit coal mining is projected to use 190 thousand metric tons of explosives in 1995. This volume is projected to grow for the next ten years, whereas the underground coal mining will hold fairly constant. Bulk explosives started in about 1977 with watergels. In the late 1980s, bulk emulsions and heavy ANFOs were introduced. This system is still being expanded and is replacing packaged products in the larger mines. Packaged products are still popular where the annual consumption is less than 2,000 metric tons per year. Also, packaged products are used in small wet shots. Porous ammonium nitrate prill have recently become available but ANFO is not very common because of the high cost of the prill and the wet blasting conditions. As the market expands there will be a continuing demand for packaged products but an increasing demand for bulk waterproof products, particularly in the larger operations. Dynamites are produced at four plants in India. The annual production of about 45,000 metric tons per year is holding fairly constant, but is likely to decrease in the future. The future blasting in India will primarily use pumped emulsions and heavy ANFO on an increasing basis, but the packaged products will maintain their position.

  9. Laser-resistance sensitivity to substrate pit size of multilayer coatings

    PubMed Central

    Chai, Yingjie; Zhu, Meiping; Wang, Hu; Xing, Huanbin; Cui, Yun; Sun, Jian; Yi, Kui; Shao, Jianda

    2016-01-01

    Nanosecond laser-resistance to dielectric multilayer coatings on substrate pits was examined with respect to the electric-field (E-field) enhancement and mechanical properties. The laser-induced damage sensitivity to the shape of the substrate pits has not been directly investigated through experiments, thus preventing clear understanding of the damage mechanism of substrate pits. We performed a systematic and comparative study to reveal the effects of the E-field distributions and localized stress concentration on the damage behaviour of coatings on substrates with pits. To obtain reliable results, substrate pits with different geometries were fabricated using a 520-nm femtosecond laser-processing platform. By using the finite element method, the E-field distribution and localized stress of the pitted region were well simulated. The 1064-nm damage morphologies of the coated pit were directly compared with simulated E-field intensity profiles and stress distributions. To enable further understanding, a simplified geometrical model was established, and the damage mechanism was introduced. PMID:27252016

  10. Laser-resistance sensitivity to substrate pit size of multilayer coatings

    NASA Astrophysics Data System (ADS)

    Chai, Yingjie; Zhu, Meiping; Wang, Hu; Xing, Huanbin; Cui, Yun; Sun, Jian; Yi, Kui; Shao, Jianda

    2016-06-01

    Nanosecond laser-resistance to dielectric multilayer coatings on substrate pits was examined with respect to the electric-field (E-field) enhancement and mechanical properties. The laser-induced damage sensitivity to the shape of the substrate pits has not been directly investigated through experiments, thus preventing clear understanding of the damage mechanism of substrate pits. We performed a systematic and comparative study to reveal the effects of the E-field distributions and localized stress concentration on the damage behaviour of coatings on substrates with pits. To obtain reliable results, substrate pits with different geometries were fabricated using a 520-nm femtosecond laser-processing platform. By using the finite element method, the E-field distribution and localized stress of the pitted region were well simulated. The 1064-nm damage morphologies of the coated pit were directly compared with simulated E-field intensity profiles and stress distributions. To enable further understanding, a simplified geometrical model was established, and the damage mechanism was introduced.

  11. 7 CFR 52.807 - Freedom from pits.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... CERTAIN OTHER PROCESSED FOOD PRODUCTS 1 United States Standards for Grades of Frozen Red Tart Pitted... allowances in this subpart is a whole pit or portions of pits computed as follows: (i) A single piece of pit shell, whether or not within or attached to a whole cherry, that is larger than one-half pit shell...

  12. 7 CFR 52.779 - Freedom from pits.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    .... Canned red tart pitted cherries that are practically free from pits may be given a score of 18 to 20 points. “Practically free from pits” means that the number of pits that may be present in the drained...) classification. Canned red tart pitted cherries that are reasonably free from pits may be given a score of 16...

  13. 76 FR 49463 - Pacific Gas and Electric Company; Notice of Authorization for Continued Project Operation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-10

    ... Project Operation On June 16, 2009, Pacific Gas and Electric Company, licensee for the McCloud-Pit... Commission's regulations thereunder. The McCloud-Pit Hydroelectric Project is located on the McCloud and Pit... authorized to continue operation of the McCloud-Pit Hydroelectric Project, until such time as the...

  14. COPPER PITTING AND PINHOLE LEAK RESEARCH STUDY

    EPA Science Inventory

    Localized copper corrosion or pitting is a significant problem at many water utilities across the United States. Copper pinhole leak problems resulting from extensive pitting are widely under reported. Given the sensitive nature of the problem, extent of damage possible, costs o...

  15. Speed, Acceleration, Chameleons and Cherry Pit Projectiles

    ERIC Educational Resources Information Center

    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…

  16. Geophysical Investigations of the Mound City Borrow Pits, Ross County, Ohio

    NASA Astrophysics Data System (ADS)

    Benson, Blair Elizabeth

    Geophysical subsurface imaging is becoming a common practice in archaeology. Non-invasive geophysical methods provide efficient alternatives to costly and invasive excavations, allowing archaeologists to analyze sites before any excavation is done to identify areas of interest. For my thesis, I investigated two prehistoric borrow pits at the Mound City Group (200 BC - 200 AD) in the Hopewell Culture National Historical Park in south-central Ohio. The primary objective of this study was to determine the presence and spatial extent of a clay lining that was emplaced upon the borrow pits by the Hopewell people. Information gleaned from the geophysical investigation was used to assess the degree of site disturbance from agriculture, construction of Camp Sherman, and modern reconstruction of the earthworks. My analysis included a suite of overlapping geophysical surveys consisting of ground-penetrating radar, magnetometry, electromagnetic induction, and electrical resistivity. The geophysical data was ground-truthed with limited auguring and trenching. Analysis of the first borrow pit data showed strong evidence of historical disturbance within the pit from construction of Camp Sherman, including disturbed soil and a buried utility pipe, leaving little of the clay lining present except around the edges of the borrow pit. The geophysical data for the second borrow pit showed less historical damage that was primarily caused from the re-excavation of the pit during the reconstruction of the park. The second borrow pit still retains about half of the clay lining, a finding supported by the results of auguring and trenching. These results are evidence that the borrow pits at Mound City may have also served a purpose as cultural landscape features. The geophysical methods used in this study proved to be an invaluable source of information with minimal disturbance of the site.

  17. The relationship between induction time for pitting and pitting potential for high purity aluminum.

    SciTech Connect

    Wall, Frederick Douglas; Vandenavyle, Justin J.; Martinez, Michael A.

    2003-08-01

    The objective of this study was to determine if a distribution of pit induction times (from potentiostatic experiments) could be used to predict a distribution of pitting potentials (from potentiodynamic experiments) for high-purity aluminum. Pit induction times were measured for 99.99 Al in 50 mM NaCl at potentials of -0.35, -0.3, -0.25, and -0.2 V vs. saturated calomel electrode. Analysis of the data showed that the pit germination rate generally was an exponential function of the applied potential; however, a subset of the germination rate data appeared to be mostly potential insensitive. The germination rate behavior was used as an input into a mathematical relationship that provided a prediction of pitting potential distribution. Good general agreement was found between the predicted distribution and an experimentally determined pitting potential distribution, suggesting that the relationships presented here provide a suitable means for quantitatively describing pit germination rate.

  18. Considerable different frequency dependence of dynamic tensile modulus between self-heating (Joule heat) and external heating for polymer--nickel-coated carbon fiber composites.

    PubMed

    Zhang, Rong; Bin, Yuezhen; Dong, Enyuan; Matsuo, Masaru

    2014-06-26

    Dynamic tensile moduli of polyethylene--nickel-coated carbon fiber (NiCF) composites with 10 and 4 vol % NiCF contents under electrical field were measured by a homemade instrument in the frequency range of 100--0.01 Hz. The drastic descent of the storage modulus of the composite with 10 vol % was verified in lower frequency range with elevating surface temperature (T(s)) by self-heating (Joule heat). The composite was cut when T(s) was beyond 108 °C. On the other hand, the measurement of the composite with 4 vol % beyond 88 °C was impossible, since T(s) did not elevate because of the disruption of current networks. Incidentally, the dynamic tensile moduli by external heating could be measured up to 130 and 115 °C for 10 and 4 vol %, respectively, but the two composites could be elongated beyond the above temperatures. Such different properties were analyzed in terms of crystal dispersions, electrical treeing, and thermal fluctuation-induced tunneling effect. PMID:24893179

  19. Considerable different frequency dependence of dynamic tensile modulus between self-heating (Joule heat) and external heating for polymer--nickel-coated carbon fiber composites.

    PubMed

    Zhang, Rong; Bin, Yuezhen; Dong, Enyuan; Matsuo, Masaru

    2014-06-26

    Dynamic tensile moduli of polyethylene--nickel-coated carbon fiber (NiCF) composites with 10 and 4 vol % NiCF contents under electrical field were measured by a homemade instrument in the frequency range of 100--0.01 Hz. The drastic descent of the storage modulus of the composite with 10 vol % was verified in lower frequency range with elevating surface temperature (T(s)) by self-heating (Joule heat). The composite was cut when T(s) was beyond 108 °C. On the other hand, the measurement of the composite with 4 vol % beyond 88 °C was impossible, since T(s) did not elevate because of the disruption of current networks. Incidentally, the dynamic tensile moduli by external heating could be measured up to 130 and 115 °C for 10 and 4 vol %, respectively, but the two composites could be elongated beyond the above temperatures. Such different properties were analyzed in terms of crystal dispersions, electrical treeing, and thermal fluctuation-induced tunneling effect.

  20. Inertially confined fusion plasmas dominated by alpha-particle self-heating

    NASA Astrophysics Data System (ADS)

    Hurricane, O. A.; Callahan, D. A.; Casey, D. T.; Dewald, E. L.; Dittrich, T. R.; Döppner, T.; Haan, S.; Hinkel, D. E.; Berzak Hopkins, L. F.; Jones, O.; Kritcher, A. L.; Le Pape, S.; Ma, T.; Macphee, A. G.; Milovich, J. L.; Moody, J.; Pak, A.; Park, H.-S.; Patel, P. K.; Ralph, J. E.; Robey, H. F.; Ross, J. S.; Salmonson, J. D.; Spears, B. K.; Springer, P. T.; Tommasini, R.; Albert, F.; Benedetti, L. R.; Bionta, R.; Bond, E.; Bradley, D. K.; Caggiano, J.; Celliers, P. M.; Cerjan, C.; Church, J. A.; Dylla-Spears, R.; Edgell, D.; Edwards, M. J.; Fittinghoff, D.; Barrios Garcia, M. A.; Hamza, A.; Hatarik, R.; Herrmann, H.; Hohenberger, M.; Hoover, D.; Kline, J. L.; Kyrala, G.; Kozioziemski, B.; Grim, G.; Field, J. E.; Frenje, J.; Izumi, N.; Gatu Johnson, M.; Khan, S. F.; Knauer, J.; Kohut, T.; Landen, O.; Merrill, F.; Michel, P.; Moore, A.; Nagel, S. R.; Nikroo, A.; Parham, T.; Rygg, R. R.; Sayre, D.; Schneider, M.; Shaughnessy, D.; Strozzi, D.; Town, R. P. J.; Turnbull, D.; Volegov, P.; Wan, A.; Widmann, K.; Wilde, C.; Yeamans, C.

    2016-08-01

    Alpha-particle self-heating, the process of deuterium-tritium fusion reaction products depositing their kinetic energy locally within a fusion reaction region and thus increasing the temperature in the reacting region, is essential for achieving ignition in a fusion system. Here, we report new inertial confinement fusion experiments where the alpha-particle heating of the plasma is dominant with the fusion yield produced exceeding the fusion yield from the work done on the fuel (pressure times volume change) by a factor of two or more. These experiments have achieved the highest yield (26 +/- 0.5 kJ) and stagnation pressures (≍220 +/- 40 Gbar) of any facility-based inertial confinement fusion experiments, although they are still short of the pressures required for ignition on the National Ignition Facility (~300-400 Gbar). These experiments put us in a new part of parameter space that has not been extensively studied so far because it lies between the no-alpha-particle-deposition regime and ignition.

  1. MEMS Flow Sensors Based on Self-Heated aGe-Thermistors in a Wheatstone Bridge.

    PubMed

    Talic, Almir; Cerimovic, Samir; Beigelbeck, Roman; Kohl, Franz; Sauter, Thilo; Keplinger, Franz

    2015-04-28

    A thermal flow transduction method combining the advantages of calorimetric and hot-film transduction principles is developed and analyzed by Finite Element Method (FEM) simulations and confirmed experimentally. The analyses include electrothermal feedback effects of current driven NTC thermistors. Four thin-film germanium thermistors acting simultaneously as heat sources and as temperature sensors are embedded in a micromachined silicon-nitride membrane. These devices form a self-heated Wheatstone bridge that is unbalanced by convective cooling. The voltage across the bridge and the total dissipated power are exploited as output quantities. The used thin-film thermistors feature an extremely high temperature sensitivity. Combined with properly designed resistance values, a power demand in sub-1mW range enables efficient gas-flow transduction, as confirmed by measurements. Two sensor configurations with different arrangements of the membrane thermistors were examined experimentally. Moreover, we investigated the influence of different layouts on the rise time, the sensitivity, and the usable flow range by means of two-dimensional finite element simulations. The simulation results are in reasonable agreement with corresponding measurement data confirming the basic assumptions and modeling approach.

  2. Co-composting of eggshell waste in self-heating reactors: monitoring and end product quality.

    PubMed

    Soares, Micaela A R; Quina, Margarida M J; Quinta-Ferreira, Rosa M

    2013-11-01

    Industrial eggshell waste (ES) is classified as an animal by-product not intended to human consumption. For reducing pathogen spreading risk due to soil incorporation of ES, sanitation by composting is a pre-treatment option. This work aims to evaluate eggshell waste recycling in self-heating composting reactors and investigate ES effect on process evolution and end product quality. Potato peel, grass clippings and rice husks were the starting organic materials considered. The incorporation of 30% (w/w) ES in a composting mixture did not affect mixture biodegradability, nor its capacity to reach sanitizing temperatures. After 25 days of composting, ES addition caused a nitrogen loss of about 10 g N kg(-1) of initial volatile solids, thus reducing nitrogen nutritional potential of the finished compost. This study showed that a composting mixture with a significant proportion of ES (30% w/w) may be converted into calcium-rich marketable compost to neutralize soil acidity and/or calcium deficiencies. PMID:24055972

  3. Arne - Exploring the Mare Tranquillitatis Pit

    NASA Astrophysics Data System (ADS)

    Robinson, M. S.; Thangavelautham, J.; Wagner, R.; Hernandez, V. A.; Finch, J.

    2014-12-01

    Lunar mare "pits" are key science and exploration targets. The first three pits were discovered within Selene observations [1,2] and were proposed to represent collapses into lava tubes. Subsequent LROC images revealed 5 new mare pits and showed that the Mare Tranquillitatis pit (MTP; 8.335°N, 33.222°E) opens into a sublunarean void at least 20-meters in extent [3,4]. A key remaining task is determining pit subsurface extents, and thus fully understanding their exploration and scientific value. We propose a simple and cost effective reconnaissance of the MTP using a small lander (<130 kg) named Arne, that carries three flying microbots (or pit-bots) [5,6,7]. Key measurement objectives include decimeter scale characterization of the pit walls, 5-cm scale imaging of the eastern floor, determination of the extent of sublunarean void(s), and measurement of the magnetic and thermal environment. After landing and initial surface systems check Arne will transmit full resolution descent and surface images. Within two hours the first pit-bot will launch and fly into the eastern void. Depending on results from the first pit-bot the second and third will launch and perform follow-up observations. The primary mission is expected to last 48-hours; before the Sun sets on the lander there should be enough time to execute ten flights with each pit-bot. The pit-bots are 30-cm diameter spherical flying robots [5,6,7] equipped with stereo cameras, temperature sensors, sensors for obstacle avoidance and a laser rangefinder. Lithium hydride [5,6] and water/hydrogen peroxide power three micro-thrusters and achieve a specific impulse of 350-400 s. Each pit-bot can fly for 2 min at 2 m/s for more than 100 cycles; recharge time is 20 min. Arne will carry a magnetometer, thermometer, 2 high resolution cameras, and 6 wide angle cameras and obstacle avoidance infrared sensors enabling detailed characterization of extant sublunarean voids. [1] Haruyama et al. (2010) 41st LPSC, #1285. [2

  4. 29. (Credit JTL) Low service pump pit in background erected ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    29. (Credit JTL) Low service pump pit in background erected in 1911-1912 on the banks of Cross Bayou (a Worthington compound duplex steam engine was placed inside this structure.) In the foreground is the receiving well (also erected in 1911-1912) which received water from the Red River siphon. After 1926 this well received water, instead, from Cross Lake via a 30-inch conduit. A concrete platform was installed in 1960 for #6 electric low service pump which has been superceded by newer 1977 installation. - McNeil Street Pumping Station, McNeil Street & Cross Bayou, Shreveport, Caddo Parish, LA

  5. Pitted keratolysis, erythromycin, and hyperhidrosis.

    PubMed

    Pranteda, Guglielmo; Carlesimo, Marta; Pranteda, Giulia; Abruzzese, Claudia; Grimaldi, Miriam; De Micco, Sabrina; Muscianese, Marta; Bottoni, Ugo

    2014-01-01

    Pitted keratolysis (PK) is a plantar skin disorder mainly caused by coryneform bacteria. A common treatment consists of the topical use of erythromycin. Hyperhidrosis is considered a predisposing factor for bacterial proliferation and, consequently, for the onset of PK. The aim of this study was to evaluate the relationship between PK erythromycin and hyperhidrosis. All patients with PK seen in Sant'Andrea Hospital, between January 2009 and December 2011, were collected. PK was clinically and microscopically diagnosed. All patients underwent only topical treatment with erythromycin 3% gel twice daily. At the beginning of the study and after 5 and 10 days of treatment, a clinical evaluation and a gravimetric measurement of plantar sweating were assessed. A total of 97 patients were diagnosed as PK and were included in the study. Gravimetric measurements showed that in 94 of 97 examined patients (96.90%) at the time of the diagnosis, there was a bilateral excessive sweating occurring specifically in the areas affected by PK. After 10 days of antibiotic therapy, hyperhidrosis regressed together with the clinical manifestations. According to these data, we hypothesize that hyperhidrosis is due to an eccrine sweat gland hyperfunction, probably secondary to bacterial infection. PMID:24703267

  6. Cherry Pit Primes Brad Pitt

    PubMed Central

    Burke, Deborah M.; Locantore, Jill Kester; Austin, Ayda A.; Chae, Bryan

    2008-01-01

    This study investigated why proper names are difficult to retrieve, especially for older adults. On intermixed trials, young and older adults produced a word for a definition or a proper name for a picture of a famous person. Prior production of a homophone (e.g., pit) as the response on a definition trial increased correct naming and reduced tip-of-the-tongue experiences for a proper name (e.g., Pitt) on a picture-naming trial. Among participants with no awareness of the homophone manipulation, older but not young adults showed these homophone priming effects. With a procedure that reduced awareness effects (Experiment 2), prior production of a homophone improved correct naming only for older adults, but speeded naming latency for both age groups. We suggest that representations of proper names are susceptible to weak connections that cause deficits in the transmission of excitation, impairing retrieval especially in older adults. We conclude that homophone production strengthens phonological connections, increasing the transmission of excitation. PMID:15016287

  7. Pitted keratolysis, erythromycin, and hyperhidrosis.

    PubMed

    Pranteda, Guglielmo; Carlesimo, Marta; Pranteda, Giulia; Abruzzese, Claudia; Grimaldi, Miriam; De Micco, Sabrina; Muscianese, Marta; Bottoni, Ugo

    2014-01-01

    Pitted keratolysis (PK) is a plantar skin disorder mainly caused by coryneform bacteria. A common treatment consists of the topical use of erythromycin. Hyperhidrosis is considered a predisposing factor for bacterial proliferation and, consequently, for the onset of PK. The aim of this study was to evaluate the relationship between PK erythromycin and hyperhidrosis. All patients with PK seen in Sant'Andrea Hospital, between January 2009 and December 2011, were collected. PK was clinically and microscopically diagnosed. All patients underwent only topical treatment with erythromycin 3% gel twice daily. At the beginning of the study and after 5 and 10 days of treatment, a clinical evaluation and a gravimetric measurement of plantar sweating were assessed. A total of 97 patients were diagnosed as PK and were included in the study. Gravimetric measurements showed that in 94 of 97 examined patients (96.90%) at the time of the diagnosis, there was a bilateral excessive sweating occurring specifically in the areas affected by PK. After 10 days of antibiotic therapy, hyperhidrosis regressed together with the clinical manifestations. According to these data, we hypothesize that hyperhidrosis is due to an eccrine sweat gland hyperfunction, probably secondary to bacterial infection.

  8. Lessons Learned from Pit Viper System Deployment

    SciTech Connect

    Catalan, Michael A.; Bailey, Sharon A.; Alzheimer, James M.; Baker, Carl P.; Valdez, Patrick L.

    2002-08-08

    The Pit Viper is a tele-operated system intended to enhance worker safety while simultaneously improving the efficiency of pit operations at the Hanford Site. Commercial off-the-shelf (COTS) components were used in an attempt to increase system reliability and reduce integration difficulties. The Pit Viper, as is, provides significant improvement over the current baseline approach. During integration, multiple areas where technology development would enhance the effectiveness of the system were identified. Most notable of these areas were the manipulator control system, tool design, and tool handling. Various issues were identified regarding the interfacing of the Pit Viper with the Tank Farm environment and the maturity of remote/ robotic systems for unstructured environments.

  9. Okay, Kids, Everyone into the Pit!

    ERIC Educational Resources Information Center

    Belle, Bob; And Others

    1988-01-01

    Discusses a typical food chain and the interrelationship between plants and animals. Describes the "Food Chain Pit" game which can be used to help students create food chains of different habitats. (RT)

  10. Changes in pit membrane porosity due to deflection and stretching: the role of vestured pits.

    PubMed

    Choat, Brendan; Jansen, Steven; Zwieniecki, Maciej A; Smets, Erik; Holbrook, N Michele

    2004-07-01

    The effect of increasing pressure difference (DeltaP) on intervessel pit membrane porosity was studied in two angiosperm tree species with differing pit architecture. Fraxinus americana L. possesses typical angiosperm bordered pit structure while Sophora japonica L. exhibits well-developed vestures in intervessel pit chambers. It was hypothesized (a) that large DeltaP across intervessel pits would cause the deflection of pit membranes in the stems of F. americana resulting in significant increases in porosity and thus lower cavitation thresholds, and (b) that the presence of vestures would prevent the deflection of pit membranes in S. japonica. To determine if the porosity of pit membranes increased under mechanical stress, suspensions of colloidal gold, 5 nm and 20 nm in diameter, were perfused across intervessel pit membranes at DeltaP ranging from 0.25 MPa to 6.0 MPa. The effect of increasing DeltaP on membrane porosity was also tested by comparing air seeding thresholds (Pa) in stems perfused with water or a solution with lower surface tension. Air seeding and colloidal gold experiments indicated that pit membrane porosity increased significantly with DeltaP in F. americana. In S. japonica, increases in permeability to colloidal gold with DeltaP were small and maximum pore diameters predicted from Pa were independent of DeltaP, suggesting that vestures limited the degree to which the membrane can be deflected from the centre of the pit cavity. This provides the first experimental evidence that vestures reduce the probability of air seeding through pit membranes. PMID:15181107

  11. Pit 9 project: A private sector initiative

    SciTech Connect

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

    1993-05-01

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

  12. Quantitative analysis of CO-humidity gas mixtures with self-heated nanowires operated in pulsed mode

    NASA Astrophysics Data System (ADS)

    Prades, J. D.; Hernández-Ramírez, F.; Fischer, T.; Hoffmann, M.; Müller, R.; López, N.; Mathur, S.; Morante, J. R.

    2010-12-01

    Self-heating effect in individual metal oxide nanowires can be used to activate their response to gases with power consumptions below tenths of microwatts. The thermal response time of these devices is extremely fast (a few milliseconds) and it makes it possible to observe the kinetics of the interactions between the gas molecules and the metal oxide. In this work we demonstrate that such effects enable an experimental methodology to improve the selectivity of metal oxide-based sensors based on the analysis of their fast response dynamics. Specifically, this work jointly analyzes the magnitude and response time of SnO2 nanowire-based sensors to carbon monoxide (CO) and humidity (H2O) mixtures, proving that a quantitative analysis of CO-H2O gas blends can be achieved by modulating their work temperature through the self-heating effect.

  13. Using pitting and protection potentials to predict pitting behavior: New insights

    SciTech Connect

    Not Available

    1991-10-01

    A literature review was performed to identify test methods that have been used to examine pitting susceptibility of alloys in chloride (Cl{sup {minus}}) containing environments. Several techniques were identified and a critical analysis of the validity of the different electrochemical methods was performed with special attention given to the causes of variations observed in the pitting, or breakdown, potential (E{sub pit}) and the protection, or repassivation, potential (E{sub prot}). Experiments were performed on Type 317L stainless steel in three solutions containing high levels of Cl{sup {minus}} and Alloy G3 in two solutions containing high levels of Cl{sup {minus}}. The test solutions were designed to simulate environments present in flue gas desulfurization systems. Cyclic potentiodynamic polarization (CPP) experiments and constant potential-time experiments (up to 60 days) were performed to examine pit initiation and repassivation; and modified ASTM F-746 tests were performed to establish the protection potential as a function of prior pitting history. Analysis of the data suggests that there exists a unique pitting potential (E{sub u}) defined by the stochastic models for pit initiation that equals the most active value of E{sub pit} (long incubation times) and that equals the most noble E{sub prot} value (measured following only minimal pit growth). 24 refs., 34 figs., 7 tabs.

  14. 7 CFR 987.105 - Whole equivalent of pitted dates.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Whole equivalent of pitted dates. For the purposes of this part, the whole date equivalent weight of pitted dates shall be determined by dividing the weight of the pitted dates by 0.83. Identification and... 7 Agriculture 8 2012-01-01 2012-01-01 false Whole equivalent of pitted dates. 987.105 Section...

  15. 7 CFR 987.105 - Whole equivalent of pitted dates.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Whole equivalent of pitted dates. For the purposes of this part, the whole date equivalent weight of pitted dates shall be determined by dividing the weight of the pitted dates by 0.83. Identification and... 7 Agriculture 8 2010-01-01 2010-01-01 false Whole equivalent of pitted dates. 987.105 Section...

  16. 7 CFR 987.105 - Whole equivalent of pitted dates.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Whole equivalent of pitted dates. For the purposes of this part, the whole date equivalent weight of pitted dates shall be determined by dividing the weight of the pitted dates by 0.83. Identification and... 7 Agriculture 8 2013-01-01 2013-01-01 false Whole equivalent of pitted dates. 987.105 Section...

  17. 7 CFR 987.105 - Whole equivalent of pitted dates.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Whole equivalent of pitted dates. For the purposes of this part, the whole date equivalent weight of pitted dates shall be determined by dividing the weight of the pitted dates by 0.83. Identification and... 7 Agriculture 8 2014-01-01 2014-01-01 false Whole equivalent of pitted dates. 987.105 Section...

  18. 7 CFR 987.105 - Whole equivalent of pitted dates.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Whole equivalent of pitted dates. For the purposes of this part, the whole date equivalent weight of pitted dates shall be determined by dividing the weight of the pitted dates by 0.83. Identification and... 7 Agriculture 8 2011-01-01 2011-01-01 false Whole equivalent of pitted dates. 987.105 Section...

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

    SciTech Connect

    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.

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

    SciTech Connect

    Palmer, E.

    1996-03-01

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

  1. Excellent scalability including self-heating phenomena of vertical-channel field-effect-diode type capacitor-less one transistor dynamic random access memory cell

    NASA Astrophysics Data System (ADS)

    Imamoto, Takuya; Endoh, Tetsuo

    2014-01-01

    The scalability study and the impact of the self-heating effect (SHE) on memory operation of the bulk vertical-channel field effect diode (FED) type capacitorless one transistor (1T) dynamic random access memory (DRAM) cell are investigated via device simulator for the first time. The vertical-channel FED type 1T-DRAM cell shows the excellent hold characteristics (100 ms at 358 K of ambient temperature) with large enough read current margin (1 µA/cell) even when silicon pillar diameter (D) is scaled down from 20 to 12 nm. It is also shown that by employing the vertical-channel FED type, maximum lattice temperature in the memory cell due to SHE (T_{\\text{L}}^{\\text{Max}}) can be suppressed to a negligible small value and only reach 300.6 from 300 K ambient temperature due to the low lateral electric field, while the vertical-channel bipolar junction transistor (BJT) type 1T-DRAM shows significant SHE (T_{\\text{L}}^{\\text{Max}} = 330.6 K). Moreover, this excellent thermal characteristic can be maintained even when D is scaled down from 20 to 12 nm.

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

    SciTech Connect

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

    2012-06-08

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

  3. Examination of pits in Trojan nuclear power plant steam generator tubes: Final report

    SciTech Connect

    Powell, D.E.

    1989-05-01

    This report presents the results from examination of defects, oxides, and corrosion products on three steam generator tubes removed from the Trojan Nuclear Plant of Portland General Electric. In-generator eddy current inspection of the steam generator tubes suggested the probability of pits in one tube, located several inches above the tubesheet, within the height of the sludge pile. A weak indication was reported in the second tube, also within the height of the sludge pile. Copper signals were reported above the tubesheet and first support plate for the third tube which was removed. Destructive examination revealed numerous pits in a band several inches above the tubesheet. The depth of the pits corresponded to those anticipated by field eddy current testing. The pits contained a chromium rich iron and nickel depleted corrosion product with traces of copper and zinc. Intergranular penetrations were present at the base of the pits. Traces of sulfur and chlorine were found within the penetrations. Additionally, nickel sulfide and copper sulfide ribbons were present within the corrosion products of the pits. Sulfate and chloride anions were also observed in concentrations of hundreds of parts per million (each) within the exterior surface oxides. Hence, the pitting corrosion was attributed to acid forms of sulfur, acting synergistically with chlorides. The oxides on the external surfaces of the steam generator tubes were found to consist of magnetite (Fe/sub 3/O/sub 4/) with minor components of franklinite (ZnFe/sub 2/O/sub 4/). Embedded within this composite were numerous particles of copper in the elemental form. 8 refs.

  4. Project W-314 241-AN-A valve pit upgrade acceptance for beneficial use

    SciTech Connect

    HAMMERS, J.S.

    1999-07-21

    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.

  5. Project W-314 241-AN-B valve pit upgrade acceptance for beneficial use

    SciTech Connect

    HAMMERS, J.S.

    1999-07-21

    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.

  6. Energy saving ideas for open pit mining

    SciTech Connect

    Rixen, W.; Benecke, K.J.

    1981-05-01

    The increasing cost of diesel fuel is making truck haulage in open pit mines less economic. Belt conveyor systems have much lower operating costs but are not as flexible in their application and require more detailed pit planning. The possibility of combining the flexibility of trucks with the low cost of conveyors is offered by the application of semi-mobile crushing plants followed by belt conveyors for the main haul out of the pit. In the first part of this article. Dr.-Ing W. Rixen describes some of the semi-mobile plants already in operation, while in the second section. Dr.-Ing K.J. Benecke discusses a theoretical case study involving trucks, crushers, and conveyors. Since a belt conveyor cannot transport rocks of a size often produced when blasting hard strata, a crusher must be installed before the belt conveyor to reduce the material to a transportable size. This also serves as a primary crusher. The crushing plant is positioned centrally in the mine and trucks haul overburden and ore from the individual faces to the crusher without having to climb long gradients. Therefore, truck haul distances and operating costs are significantly reduced. The resulting savings in operating costs greatly exceeds the additional capital costs for the crushing plant. The use of fully mobile crushers directly fed by the face shovel is well established. Whereas the partial elimination of truck haulage by semi-mobile in-pit crushers is a more recent development. This latter method restricts truck haulage to in-pit operation only, saving costly haulage of material up-grade out of the pit to the crusher or overburden dump. It is particularly applicable to operations where blending is required. In such cases, the flexibility and adaptability of trucks to frequently changing faces is essential, while the semi-mobile crusher reduces haul distances to a minimum.

  7. Arsia Mons Collapse Pits in IR

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    We will be looking at collapse pits for the next two weeks. Collapse pits on Mars are formed in several ways. In volcanic areas, channelized lava flows can form roofs which insulate the flowing lava. These features are termed lava tubes on Earth and are common features in basaltic flows. After the lava has drained, parts of the roof of the tube will collapse under its own weight. These collapse pits will only be as deep as the bottom of the original lava tube. Another type of collapse feature associated with volcanic areas arises when very large eruptions completely evacuate the magma chamber beneath the volcano. The weight of the volcano will cause the entire edifice to subside into the void space below it. Structural features including fractures and graben will form during the subsidence. Many times collapse pits will form within the graben. In addition to volcanic collapse pits, Mars has many collapse pits formed when volatiles (such as subsurface ice) are released from the surface layers. As the volatiles leave, the weight of the surrounding rock causes collapse pits to form.

    These collapse pits are found on the flank of Arsia Mons and are related to lava tube collapse.

    Image information: IR instrument. Latitude -8.8, Longitude 240.4 East (119.6 West). 100 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal

  8. The impact of the thermal conductivity of a dielectric layer on the self-heating effect of a graphene transistor.

    PubMed

    Pan, T S; Gao, M; Huang, Z L; Zhang, Y; Feng, Xue; Lin, Y

    2015-08-28

    The self-heating effect of a graphene transistor on the transport properties was studied. Different dielectric layers, SiO2 and AlN, which have different thermal conductivities, were used to tune the thermal dissipation of the graphene transistor. An obvious change in channel resistance and a shift of charge neutrality point were observed during the operation of the transistor with SiO2, while the change is slight when AlN is the dielectric layer. This observation is considered to be related to the temperature determined desorption rate of p-type dopants in graphene.

  9. Two-stage plasma gun based on a gas discharge with a self-heating hollow emitter.

    PubMed

    Vizir, A V; Tyunkov, A V; Shandrikov, M V; Oks, E M

    2010-02-01

    The paper presents the results of tests of a new compact two-stage bulk gas plasma gun. The plasma gun is based on a nonself-sustained gas discharge with an electron emitter based on a discharge with a self-heating hollow cathode. The operating characteristics of the plasma gun are investigated. The discharge system makes it possible to produce uniform and stable gas plasma in the dc mode with a plasma density up to 3x10(9) cm(-3) at an operating gas pressure in the vacuum chamber of less than 2x10(-2) Pa. The device features high power efficiency, design simplicity, and compactness.

  10. COPPER PITTING CORROSION: A CASE STUDY

    EPA Science Inventory

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

  11. Extracting Valuable Data from Classroom Trading Pits

    ERIC Educational Resources Information Center

    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. Global methane emissions from pit latrines.

    PubMed

    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.

  13. OVERVIEW, LOOKING SOUTHWEST, TO 8750 PIT WITH DRILL SETTING AN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    OVERVIEW, LOOKING SOUTHWEST, TO 8750 PIT WITH DRILL SETTING AN EXPLOSIVE CHARGE TO REMOVE OVERBURDEN AND ACCESS COAL SEAMS LOCATED 200 FEET BELOW FOR STRIPPING. - Drummond Coal Company Cedrum Mine, 8750 Pit, County Road 124, Townley, Walker County, AL

  14. LONGITUDINAL VIEW OF THE SOAKING PIT BUILDING INTERIOR WITH OPEN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    LONGITUDINAL VIEW OF THE SOAKING PIT BUILDING INTERIOR WITH OPEN HEARTH IN BACKGROUND AND FURNACE PIT/ STACK AREA TO THE LEFT. - Pittsburgh Steel Company, Monessen Works, Open Hearth Plant, Donner Avenue, Monessen, Westmoreland County, PA

  15. Looking west inside of the soaking pit building for the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Looking west inside of the soaking pit building for the 44" slab mill at a red hot ingot being removed from a pit. - U.S. Steel Edgar Thomson Works, 44" Slab Mill, Along Monongahela River, Braddock, Allegheny County, PA

  16. GENERAL OVERVIEW, LOOKING EAST, FROM RECLAIMED PASTURE TO 8750 PIT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    GENERAL OVERVIEW, LOOKING EAST, FROM RECLAIMED PASTURE TO 8750 PIT WITH STRIPPING AND RECLAMATION ACTIVITY ONGOING SIDE BY SIDE. - Drummond Coal Company Cedrum Mine, 8750 Pit, County Road 124, Townley, Walker County, AL

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

    SciTech Connect

    Roeder-Smith, Lynne

    2002-06-30

    The Pit Viper - a remote operations waste retrieval system - was developed to replace manual operations in the valve pits of waste storge 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.

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

    NASA Astrophysics Data System (ADS)

    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. An investigation of the self-heating phenomenon in viscoelastic materials subjected to cyclic loadings accounting for prestress

    NASA Astrophysics Data System (ADS)

    de Lima, A. M. G.; Rade, D. A.; Lacerda, H. B.; Araújo, C. A.

    2015-06-01

    It has been demonstrated by many authors that the internal damping mechanism of the viscoelastic materials offers many possibilities for practical engineering applications. However, in traditional procedures of analysis and design of viscoelastic dampers subjected to cyclic loadings, uniform, constant temperature is generally assumed and do not take into account the self-heating phenomenon. Moreover, for viscoelastic materials subjected to dynamic loadings superimposed on static preloads, such as engine mounts, these procedures can lead to poor designs or even severe failures since the energy dissipated within the volume of the material leads to temperature rises. In this paper, a hybrid numerical-experimental investigation of effects of the static preloads on the self-heating phenomenon in viscoelastic dampers subjected to harmonic loadings is reported. After presenting the theoretical foundations, the numerical and experimental results obtained in terms of the temperature evolutions at different points within the volume of the viscoelastic material for various static preloads are compared, and the main features of the methodology are discussed.

  20. A Study on Self-Heating and Mutual Thermal Coupling in SiGe Multi-Finger HBTs

    NASA Astrophysics Data System (ADS)

    Dwivedi, A. D. D.; D'Esposito, Rosario; Sahoo, Amit Kumar; Fregonese, Sebastien; Zimmer, Thomas

    2016-11-01

    In this paper, the self-heating and mutual thermal coupling in a state-of-the-art SiGe:C multi-finger heterojunction bipolar transistor (HBT) was investigated in static dc operation conditions. Multi-finger HBT structure was created using Sentaurus structure editor with dimensions similar to the layout of SiGe:C multi-finger HBTs in ST-Microelectronics BiCMOS55 (B55) technology ( f T > 300 GHz, f max > 400 GHz) as per ST's BiCMOS55 process design kit guidelines. Three-dimensional thermal technology computer aided design (TCAD) simulations were carried out to obtain the temperature distribution in static dc operation. The lattice temperature ( T Lattice) and heat flux ( F Heat) distribution inside the device were studied. The impact of back-end-of-line (BEOL) layers on static thermal behavior of the state-of-the-art SiGe:C multi finger HBTs was also investigated. The temperature dependent thermal resistance of different fingers of the trench isolated SiGe multi-finger HBT was extracted without and with back-end-of-line (BEOL) effect. An electro-thermal dc compact model of self-heating and mutual thermal coupling in multi-finger HBTs was proposed and applied to compare the modeling results with the TCAD simulation results. Very good agreement was achieved between results obtained from TCAD simulation and those obtained from compact model-based simulation.

  1. A Study on Self-Heating and Mutual Thermal Coupling in SiGe Multi-Finger HBTs

    NASA Astrophysics Data System (ADS)

    Dwivedi, A. D. D.; D'Esposito, Rosario; Sahoo, Amit Kumar; Fregonese, Sebastien; Zimmer, Thomas

    2016-07-01

    In this paper, the self-heating and mutual thermal coupling in a state-of-the-art SiGe:C multi-finger heterojunction bipolar transistor (HBT) was investigated in static dc operation conditions. Multi-finger HBT structure was created using Sentaurus structure editor with dimensions similar to the layout of SiGe:C multi-finger HBTs in ST-Microelectronics BiCMOS55 (B55) technology (f T > 300 GHz, f max > 400 GHz) as per ST's BiCMOS55 process design kit guidelines. Three-dimensional thermal technology computer aided design (TCAD) simulations were carried out to obtain the temperature distribution in static dc operation. The lattice temperature (T Lattice) and heat flux (F Heat) distribution inside the device were studied. The impact of back-end-of-line (BEOL) layers on static thermal behavior of the state-of-the-art SiGe:C multi finger HBTs was also investigated. The temperature dependent thermal resistance of different fingers of the trench isolated SiGe multi-finger HBT was extracted without and with back-end-of-line (BEOL) effect. An electro-thermal dc compact model of self-heating and mutual thermal coupling in multi-finger HBTs was proposed and applied to compare the modeling results with the TCAD simulation results. Very good agreement was achieved between results obtained from TCAD simulation and those obtained from compact model-based simulation.

  2. 99. ARAIII. Overall view of drilling area in reactor pit. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    99. ARA-III. Overall view of drilling area in reactor pit. Bridge over pit in use for operations. Shows water in pool, reactor, hoist, operators, and general view of interior of reactor pit area. August 12, 1963. Ineel photo no. 63-4454. Photographer: Benson. - Idaho National Engineering Laboratory, Army Reactors Experimental Area, Scoville, Butte County, ID

  3. 10. Turbine Pit of Unit 5, view to the north. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. Turbine Pit of Unit 5, view to the north. Note the difference in configuration within this turbine pit as compared to one of the original pits illustrated in photograph number MT-105-A-11. - Washington Water Power Clark Fork River Noxon Rapids Hydroelectric Development, Powerhouse, South bank of Clark Fork River at Noxon Rapids, Noxon, Sanders County, MT

  4. 7 CFR 52.807 - Freedom from pits.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... substantially free from any adhering sirup, sugar, or other packing medium. (c) (A) Classification. Frozen red tart pitted cherries that are practically free from pits may be given a score of 18 to 20 points. “Practically free from pits” means that the number of pits that may be present does not exceed the...

  5. 30 CFR 56.3131 - Pit or quarry wall perimeter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Pit or quarry wall perimeter. 56.3131 Section... Mining Methods § 56.3131 Pit or quarry wall perimeter. In places where persons work or travel in... stripped back for at least 10 feet from the top of the pit or quarry wall. Other conditions at or near...

  6. Metastable pitting of carbon steel under potentiostatic control

    SciTech Connect

    Cheng, Y.F.; Luo, J.L.

    1999-03-01

    The metastable pitting of A516-70 carbon steel was studied under potentiostatic control in solutions containing chloride ions. It was shown that there were different current fluctuation patterns and spectral slopes, that is, roll-off slopes, in passivity, general corrosion, and metastable pitting. Pits were often covered by a deposit which played an important role in the current fluctuation, with a quick current rise followed by a slow drop. There was a transitional potential (about 0 mV vs Ag/AgCl electrode) below which the metastable pitting initiation rate increased with the potential, because more sites would be activated. Above the transitional potential, the decay of the pitting occurrence rate with increased potential was due to the elimination of available pit sites. When the applied potential was between {minus}50 and 100 mV, pit growth kinetics was controlled by the potential drop through the deposit over the pit mouth. The potential dependence of repassivation time was mainly due to the effect of applied potential on the deposit over the pit mouth. There seemed to be good agreement between the calculated pit size and the measured values by optical microphotography. The assumption of hemispherical pit geometry was reasonable in calculating the pit radii.

  7. THE INFLUENCE OF NANOENGINEERED Cu DEFECTS ON ALUMINUM PITTING INITIATION

    SciTech Connect

    WALL,F.D.; SON,K.A.; MISSERT,N.A.; BARBOUR,J.C.; MARTINEZ,M.A.; ZAVIDIL,K.R.; SULLIVAN,J.P.; GOPELAND,R.G.; CIESLAK,W.R.; BUCHHEIT,R.G.; ISAACS,H.S.

    1999-11-01

    Nanoengineering technologies have been used to generate well defined arrays of pure Cu islands within an Al thin film matrix in order to examine the impact of noble particle defects on the initiation of metastable pitting. The Cu particles form local galvanic cells with the surrounding Al matrix and drive metastable corrosion. Electrical isolation of the Cu particles from the Al occurs due to selective Al dissolution and appears to correlate to cessation of metastable events. Distributions of parameters related to the electrochemical signature of an event suggests that size and spacing of particles do not impact the signatures of individual events. However, event frequency data indicate that the propensity for a structure to induce localized events is linked to Cu island diameter and separation.

  8. Corrosion pitting of SiC by molten salts

    NASA Technical Reports Server (NTRS)

    Jacobson, N. S.; Smialek, J. L.

    1986-01-01

    The corrosion of SiC by thin films of Na2CO3 and Na2SO4 at 1000 C is characterized by a severe pitting attack of the SiC substrate. A range of different Si and SiC substrates were examined to isolate the factors critical to pitting. Two types of pitting attack are identified: attack at structural discontinuities and a crater-like attack. The crater-like pits are correlated with bubble formation during oxidation of the SiC. It appears that bubbles create unprotected regions, which are susceptible to enhanced attack and, hence, pit formation.

  9. Treatment of a mud pit by bioremediation.

    PubMed

    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

  10. Pitting corrosion resistant austenite stainless steel

    DOEpatents

    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.

  11. Pits, pipes, ponds--and me.

    PubMed

    Mara, Duncan

    2013-05-01

    My life in low-cost sanitation and low-cost wastewater treatment and the use of treated wastewater in agriculture and aquaculture really has been 'pits, pipes and ponds' - 'pits' are low-cost sanitation technologies (LCST) such as VIP latrines and pour-flush toilets; 'pipes' are low-cost sewerage, principally condominial (simplified) sewerage; and 'ponds' are low-cost wastewater treatment systems, especially waste stabilization ponds, and the use of treated wastewater in agriculture and aquaculture. 'Pits' were mainly working on World Bank LCST research projects, with fieldwork principally in Zimbabwe, 'pipes' were working on condominial sewerage projects in Brazil and disseminating this LCST to a wider global audience, and 'ponds' were waste stabilization ponds, with fieldwork mainly in Brazil, Colombia, Portugal and the United Kingdom, the development of aerated rock filters to polish facultative-pond effluents, and the human-health aspects of treated wastewater use in agriculture and aquaculture, with fieldwork in Brazil and the UK, and the application of quantitative microbial risk analysis. The paper provides a professional perspective and lessons from historical developments and gives recommended future directions based on my career working on low-cost sanitation technologies and treated wastewater use in agriculture and aquaculture.

  12. Pits, pipes, ponds--and me.

    PubMed

    Mara, Duncan

    2013-05-01

    My life in low-cost sanitation and low-cost wastewater treatment and the use of treated wastewater in agriculture and aquaculture really has been 'pits, pipes and ponds' - 'pits' are low-cost sanitation technologies (LCST) such as VIP latrines and pour-flush toilets; 'pipes' are low-cost sewerage, principally condominial (simplified) sewerage; and 'ponds' are low-cost wastewater treatment systems, especially waste stabilization ponds, and the use of treated wastewater in agriculture and aquaculture. 'Pits' were mainly working on World Bank LCST research projects, with fieldwork principally in Zimbabwe, 'pipes' were working on condominial sewerage projects in Brazil and disseminating this LCST to a wider global audience, and 'ponds' were waste stabilization ponds, with fieldwork mainly in Brazil, Colombia, Portugal and the United Kingdom, the development of aerated rock filters to polish facultative-pond effluents, and the human-health aspects of treated wastewater use in agriculture and aquaculture, with fieldwork in Brazil and the UK, and the application of quantitative microbial risk analysis. The paper provides a professional perspective and lessons from historical developments and gives recommended future directions based on my career working on low-cost sanitation technologies and treated wastewater use in agriculture and aquaculture. PMID:23490108

  13. Constituent Particle Clustering and Pitting Corrosion

    NASA Astrophysics Data System (ADS)

    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.

  14. Multilayer deformation planarization by substrate pit suturing.

    PubMed

    Chai, Yingjie; Zhu, Meiping; Xing, Huanbin; Wang, Hu; Cui, Yun; Shao, Jianda

    2016-08-01

    In the pursuit of 1064 nm high-power laser resistance dielectric coatings in the nanosecond region, a group of HfO2/SiO2 high reflectors with and without suture layers were prepared on prearranged fused silica substrates with femtosecond laser pits. Surface morphology, global coating stress, and high-resolution cross sections were characterized to determine the effects of substrate pit suturing. Laser-induced damage resistance was investigated for samples with and without suture layers. Our results indicate considerable stability in terms of the nanosecond 1064 nm laser-induced damage threshold for samples having a suture layer, due to decreased electronic field (e-field) deformation with simultaneous elimination of internal cracks. In addition, a suture layer formed by plasma ion-assisted deposition could effectively improve global mechanical stress of the coatings. By effectively reducing the multilayer deformation using a suture layer, electron-beam high-reflective coatings, whose laser-induced damage resistance was not influenced by the substrate pit, can be prepared. PMID:27472579

  15. Self-heating effects of a surface-oxidized FeCo nanoparticle colloid under an alternating magnetic field

    NASA Astrophysics Data System (ADS)

    Kim, Jinu; Kim, Ki Hyeon; Nam, Baekil

    2016-08-01

    To evaluate the self-heating effects of FeCo magnetic nanoparticles, we synthesized surfaceoxidized FeCo nanoparticles by using the co-precipitation method with the reduction reaction without any post treatments. As-synthesized FeCo nanoparticles exhibited a mean diameter of about 39 nm with an oxidized shell thickness of about 4 - 5 nm. The saturation magnetization and coercivity were found to be 172 emu/g and 268 Oe at 300 K, respectively. The heat elevation of the FeCo magnetic colloid was measured under alternating magnetic fields of 76, 102, and 127 Oe with selectable frequencies of 190, 250 and 355 kHz. The heat temperature increased up to about 45 °C from an initial temperature of 24 °C under a 127 Oe field with a frequency of 355 kHz, at which the specific absorption was about 35.7 W/g.

  16. Effects of self-heating and phase change on the thermal profile of hydrogen isotopes in confined geometries

    SciTech Connect

    Baxamusa, S. Field, J.; Dylla-Spears, R.; Kozioziemski, B.; Suratwala, T.; Sater, J.

    2014-03-28

    Growth of high-quality single-crystal hydrogen in confined geometries relies on the in situ formation of seed crystals. Generation of deuterium-tritium seed crystals in a confined geometry is governed by three effects: self-heating due to tritium decay, external thermal environment, and latent heat of phase change at the boundary between hydrogen liquid and vapor. A detailed computation of the temperature profile for liquid hydrogen inside a hollow shell, as is found in inertial confinement fusion research, shows that seeds are likely to form at the equatorial plane of the shell. Radioactive decay of tritium to helium slowly alters the composition of the hydrogen vapor, resulting in a modified temperature profile that encourages seed formation at the top of the shell. We show that the computed temperature profile is consistent with a variety of experimental observations.

  17. THE USE OF A TREATABILITY STUDY TO INVESTIGATE THE POTENTIAL FOR SELF HEATING & EXOTHERMIC REACTIONS IN DECONTAMINATION MATERIALS AT PFP

    SciTech Connect

    HOPKINS, A.M.

    2005-02-23

    Cerium Nitrate has been proposed for use in the decontamination of plutonium contaminated equipment at the Plutonium Finishing Plant (PFP) located on the Hanford Nuclear Reservation in eastern Washington. A Treatability Study was conducted to determine the validity of this decontamination technology in terms of meeting its performance goals and to understand the risks associated with the use of Cerium Nitrate under the conditions found at the PFP. Fluor Hanford is beginning the decommissioning of the PFP at the Hanford site. Aggressive chemicals are commonly used to remove transuranic contaminants from process equipment to allow disposal as low level waste. Chemicals being considered for decontamination of gloveboxes in PFP include cerium (IV) nitrate in a nitric acid solution, and proprietary commercial solutions that include acids, degreasers, and sequestering agents. Fluor's decontamination procedure involves application of the chemicals, followed by a wipe-down of the contaminated surfaces with rags. This process effectively transfers the decontamination liquids containing the transuranic materials to the rags, which can then be readily packaged for disposal as TRU waste. As part of a treatability study, Fluor Hanford and the Pacific Northwest National Laboratory (PNNL) have evaluated the potential for self-heating and exothermic reactions in the residual decontamination materials and the waste packages. Laboratory analyses and thermal-hydraulic modeling reveal a significant self-heating risk for cerium nitrate solutions when used with cotton rags. Exothermic reactions that release significant heat and off-gas have been discovered for cerium nitrate at higher temperatures. From these studies, limiting conditions have been defined to assure safe operations and waste packaging.

  18. Drainage pits in cohesionless materials: implications for surface of Phobos.

    PubMed

    Horstman, K C; Melosh, H J

    1989-09-10

    Viking orbiter images show grooves and chains of pits crossing the surface of Phobos, many of which converge toward the large crater Stickney or its antipode. Although it has been proposed that the pits and grooves are chains of secondary craters, their morphology and geometric relations suggest that they are the surface traces of fractures in the underlying solid body of Phobos. Several models have been proposed to explain the pits, of which the most plausible are gas venting and drainage of regolith into open fractures. the latter mechanism is best supported by the image data and is the mechanism studied in this investigation. Drainage pits and fissures are modeled experimentally by using two rigid substrate plates placed edge to edge and covered by uniform thicknesses of dry fragmental debris (simulated regolith). Fracture extension is simulated by drawing the plates apart, allowing drainage of regolith into the newly created void. A typical drainage experiment begins with a shallow depression on the surface of the regolith, above the open fissure. Increased drainage causes local drainage pits to form; continued drainage causes the pits to coalesce, forming a cuspate groove. The resulting experimental patterns of pits and grooves have pronounced similarities to those observed on Phobos. Characteristics such as lack of raised rims, linearity of grooves and chains of pits, uniform spacing of pits, and progression from discrete pits to cuspate grooves are the same in the experiments and on Phobos. In contrast, gas-venting pits occur in irregular chains and have raised rims. These experiments thus indicate that the Phobos grooves and pits formed as drainage structures. The pit spacing in an experiment is measured at the time that the maximum number of pits forms, prior to groove development. The average pit spacing is compared to the regolith thickness for each material. Regression line fits indicate that the average spacing of drainage pits in unconsolidated

  19. Drainage pits in cohesionless materials: implications for surface of Phobos.

    PubMed

    Horstman, K C; Melosh, H J

    1989-09-10

    Viking orbiter images show grooves and chains of pits crossing the surface of Phobos, many of which converge toward the large crater Stickney or its antipode. Although it has been proposed that the pits and grooves are chains of secondary craters, their morphology and geometric relations suggest that they are the surface traces of fractures in the underlying solid body of Phobos. Several models have been proposed to explain the pits, of which the most plausible are gas venting and drainage of regolith into open fractures. the latter mechanism is best supported by the image data and is the mechanism studied in this investigation. Drainage pits and fissures are modeled experimentally by using two rigid substrate plates placed edge to edge and covered by uniform thicknesses of dry fragmental debris (simulated regolith). Fracture extension is simulated by drawing the plates apart, allowing drainage of regolith into the newly created void. A typical drainage experiment begins with a shallow depression on the surface of the regolith, above the open fissure. Increased drainage causes local drainage pits to form; continued drainage causes the pits to coalesce, forming a cuspate groove. The resulting experimental patterns of pits and grooves have pronounced similarities to those observed on Phobos. Characteristics such as lack of raised rims, linearity of grooves and chains of pits, uniform spacing of pits, and progression from discrete pits to cuspate grooves are the same in the experiments and on Phobos. In contrast, gas-venting pits occur in irregular chains and have raised rims. These experiments thus indicate that the Phobos grooves and pits formed as drainage structures. The pit spacing in an experiment is measured at the time that the maximum number of pits forms, prior to groove development. The average pit spacing is compared to the regolith thickness for each material. Regression line fits indicate that the average spacing of drainage pits in unconsolidated

  20. Flyover Modeling of Planetary Pits - Undergraduate Student Instrument Project

    NASA Astrophysics Data System (ADS)

    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

  1. Detecting pits in tart cherries by hyperspectral transmission imaging

    NASA Astrophysics Data System (ADS)

    Qin, Jianwei; Lu, Renfu

    2004-11-01

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

  2. Experimental investigation of road snow-melting based on CNFP self-heating concrete

    NASA Astrophysics Data System (ADS)

    Zhang, Qiangqiang; Li, Hui

    2011-04-01

    In this study, the road snow-melting system consisted of CNFP thermal source, AlN/Epoxy-based insulated-encapsulated layer and MWCNT/cement-based thermal conductive layer, was fabricated. The carbon nano-fiber paper (CNFP) taken excellent thermal and electrical properties was integrated into snow-melting system as the high-efficient thermal source. The remarkable electro-thermal and resistive properties of CNFP with the thickness of 0.38mm were investigated, and verified much higher efficiency electro-thermal property than other papery materials. The linearly temperature-dependent effect of CNFP resistivity was founded in certain temperature scope and met the line model as a function of temperature. Carbon nanotubes (CNT) attracted many filed scholars' focus based on its unique thermal conduction as a strong thermal-transferring candidate since it was founded. A new approach, named electric repulsion/high-frequency oscillatory dispersion, was proposed to fabricate the MWCNT/cement-based composites. The sample, filled with 3% MWCNT by the amount of cement, presents the significant improvement of thermal conductive property in contrast with other fillers and dispersing methods, which was integrated into snow-melting system with other parts as the thermal conductive layer material. The AlN/Epoxy-based composite, filled with 20% micron-AlN by the weight of mixture as the best candidate of insulated-capsulation material, would be used to guarantee the insulation. Due to the snow-melting field test, the snow-melting characteristics of integrated snow-melting system, dependent on the ambient temperature, wind speed, heat flux density and snow thickness, were investigated. The results not only verified the high-efficient, stable, feasible and economic properties, but also provided the valuable parameters for further snow-melting or ice-deicing investigation.

  3. Orientation dependence and bonding during pitting corrosion of HCP metals.

    SciTech Connect

    Lillard, Robert Scott

    2002-01-01

    The orientation dependence of pitting in single crystal beryllium (Be) is compared to the observations for single crystal zinc (Zn) reported by other investigators. The pit walls in stable propagating pits for prism planes were always square; in the (ioio) surface the walls were normal to the [0001] and [{bar 1}2{bar 1}0] directions while in the (110) surface the walls were normal to the [0001] and [{bar 1}100] directions. In addition, for the (ioio) and (11{bar 2}0) surfaces the pit interiors were characterized by crystallographically oriented parallel plates of unattacked Be. The orientation of these lamella was quite different than those observed in Zn. To explain this difference, the electron density distributions in the metal lattices are analyzed. A conceptual model for crystallographic pitting is introduced. In this model it is proposed that the crystallographic pits observed in single crystal hcp metals reflects the bond energy in the lattice.

  4. Coordinate Measuring Machine Pit Artifact Inspection Procedure

    SciTech Connect

    Montano, Joshua D.

    2012-07-31

    The goal of this document is to outline a procedure for dimensional measurement of Los Alamos National Laboratory's CMM Pit Artifact. This procedure will be used by the Manufacturing Practice's Inspection Technology Subgroup of the Interagency Manufacturing Operations Group and Joint Operations Weapon Operations Group (IMOG/JOWOG 39) round robin participants. The intent is to assess the state of industry within the Nuclear Weapons Complex for measurements made on this type of part and find which current measurement strategies and techniques produce the best results.

  5. The Pit and the Safety Pendulum

    SciTech Connect

    Nitschke, Robert Leon; Ramos, Amadeo Gabriel

    2000-11-01

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

  6. Analysis and cleaning of dirty W48 pits

    SciTech Connect

    LeMay, J.D.

    1996-04-01

    This presentation will summarize the results of an investigation of a dirty W48 pit and the subsequent development of a process for cleaning this class of pits in preparation for long-term storage. The residues of the dirty pit were analyzed for chemical identification and evidence of species known to promote corrosion of the metal cladding. The cleaning process was developed to reduce the potential for future corrosion during long-term storage.

  7. 18. DETAIL, INSPECTION PIT Delaware, Lackawanna & Western Railroad ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. DETAIL, INSPECTION PIT - Delaware, Lackawanna & Western Railroad Freight & Rail Yard, Multiple Unit Light Inspection Shed, New Jersey Transit Hoboken Terminal Rail Yard, Hoboken, Hudson County, NJ

  8. Lessons Learned from Pit Viper System Deployment

    SciTech Connect

    Catalan, Michael A.; Alzheimer, James M.; Valdez, Patrick LJ; Bailey, Sharon A.; Baker, Carl P.

    2002-04-11

    Tele-operated and robotic systems operated in unstructured field environments pose unique challenges for tool design. Since field tasks are not always well defined and the robot work area usually cannot be designed for ease of operation, the tools must be versatile. It's important to carefully consider the orientation of the grip the robot takes on the tool, as it's not easily changed in the field. The stiffness of the robot and the possibility of robot positioning errors encourages the use of non-contact or minimal-contact tooling. While normal hand tools can usually be modified for use by the robot, this is not always the most effective approach. It's desirable to have tooling that is relatively independent of the robot; in this case, the robot places the tool near the desired work location and the tool performs its task relatively independently. Here we consider the adaptation of a number of tools for cleanup of a radioactively contaminated piping junction and valve pit. The tasks to be considered are debris removal (small nuts and bolts and pipe up to 100 mm in diameter), size reduction, surface cleaning, and support of past practice crane-based methods for working in the pits.

  9. Introduction to Pits and Weapons Systems (U)

    SciTech Connect

    Kautz, D.

    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.

  10. Cloning of the full length pig PIT1 (POU1F1) CDNA and a novel alternative PIT1 transcript, and functional studies of their encoded proteins.

    PubMed

    Yu, T P; Sun, H S; Wahls, S; Sanchez-Serrano, I; Rothschild, M F; Tuggle, C K

    2001-05-01

    PIT1 is an essential regulatory gene of growth hormone (GH), prolactin (PRL) and thyrotropin beta subunit (TSHbeta). Previously, a partial pig PIT1 cDNA and a genomic clone of the entire 3' end of the PIT1 gene was isolated, and polymorphisms at PIT1 were associated with several performance traits in the pig. In order to understand the biological function of the pig PIT1 gene and its possible application in swine genetics, reverse transcriptase-polymerase chain reaction (RT-PCR) was used to complete the cloning of the full length cDNA for pig PIT1. The pig PIT1 cDNA and its deduced protein sequence have approximately 90% and 95% identity, respectively, with the PIT1 cDNA and protein of other mammals (human, bovine, sheep and rodents). Surprisingly, sequence comparison to other pig PIT1 sequences indicated only approximately 93% identity. Additional sequencing confirmed our sequence, and identified a new polymorphism in exon 4. Phylogenetic analysis of several mammalian PIT1 sequences indicates sequencing errors may account for the discrepancies observed in the other pig sequences reported. Several PIT1 alternative spliced forms were also identified by RT-PCR. They were the delta3PIT1 (missing entire exon 3), delta4PIT1 (missing entire exon 4) and PIT1beta (additional 26 amino acids inserted in front of exon 2) transcripts. The delta4PIT1 and PIT1beta transcripts have been found to encode functionally different proteins in rodents. The delta3PIT1 transcript is a novel isoform of PIT1. Potentially different functions between pig delta3PIT1 and PIT1 were analyzed by expressing these proteins in bacteria. The E. coli-expressed PIT1 and delta3PIT1 proteins were used with rat growth hormone (rGH) and rat prolactin (rPRL) promoter DNA in DNA mobility shift assays. The results showed that pig PIT1 can specifically bind rGH and rPRL promoter regions, but that the pig delta3PIT1 cannot, even at very high protein concentrations. Possible protein-protein interactions between

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

    PubMed

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

    2014-12-01

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

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

    PubMed

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

    2014-12-01

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

  13. Power delivery and self-heating in nanoscale near field transducer for heat-assisted magnetic recording.

    PubMed

    Zhou, Nan; Traverso, Luis M; Xu, Xianfan

    2015-03-27

    To keep increasing the storage density in next-generation hard disk drives, heat-assisted magnetic recording is being developed where a nanoscale near field transducer (NFT) locally and temporally heats a sub-diffraction-limited region in the recording medium to reduce the magnetic coercivity. This allows the use of very small grain in the medium while still maintaining data thermal stability. Plasmonic nanostructures made of apertures or antennas are good candidates for NFTs because of their capability of subwavelength light manipulation in optical frequencies. The NFT must simultaneously deliver enough power to the recording medium with as small as possible incident laser power to reduce self-heating in the NFT, which could cause thermal expansion and materials failure that lead to degradation of the overall hard drive performance. In this work, we study the effect of optical properties on the power delivery efficiency of nanoscale bowtie aperture antennas, with the presence of a recording media stack. Heat dissipation and temperature rise in the NFT are also computed to investigate their dependence on materials' properties. The possibility of using alternative plasmonic materials for delivering higher power and/or reducing heating in NFTs is discussed.

  14. Power delivery and self-heating in nanoscale near field transducer for heat-assisted magnetic recording

    NASA Astrophysics Data System (ADS)

    Zhou, Nan; Traverso, Luis M.; Xu, Xianfan

    2015-03-01

    To keep increasing the storage density in next-generation hard disk drives, heat-assisted magnetic recording is being developed where a nanoscale near field transducer (NFT) locally and temporally heats a sub-diffraction-limited region in the recording medium to reduce the magnetic coercivity. This allows the use of very small grain in the medium while still maintaining data thermal stability. Plasmonic nanostructures made of apertures or antennas are good candidates for NFTs because of their capability of subwavelength light manipulation in optical frequencies. The NFT must simultaneously deliver enough power to the recording medium with as small as possible incident laser power to reduce self-heating in the NFT, which could cause thermal expansion and materials failure that lead to degradation of the overall hard drive performance. In this work, we study the effect of optical properties on the power delivery efficiency of nanoscale bowtie aperture antennas, with the presence of a recording media stack. Heat dissipation and temperature rise in the NFT are also computed to investigate their dependence on materials’ properties. The possibility of using alternative plasmonic materials for delivering higher power and/or reducing heating in NFTs is discussed.

  15. Power delivery and self-heating in nanoscale near field transducer for heat-assisted magnetic recording.

    PubMed

    Zhou, Nan; Traverso, Luis M; Xu, Xianfan

    2015-03-27

    To keep increasing the storage density in next-generation hard disk drives, heat-assisted magnetic recording is being developed where a nanoscale near field transducer (NFT) locally and temporally heats a sub-diffraction-limited region in the recording medium to reduce the magnetic coercivity. This allows the use of very small grain in the medium while still maintaining data thermal stability. Plasmonic nanostructures made of apertures or antennas are good candidates for NFTs because of their capability of subwavelength light manipulation in optical frequencies. The NFT must simultaneously deliver enough power to the recording medium with as small as possible incident laser power to reduce self-heating in the NFT, which could cause thermal expansion and materials failure that lead to degradation of the overall hard drive performance. In this work, we study the effect of optical properties on the power delivery efficiency of nanoscale bowtie aperture antennas, with the presence of a recording media stack. Heat dissipation and temperature rise in the NFT are also computed to investigate their dependence on materials' properties. The possibility of using alternative plasmonic materials for delivering higher power and/or reducing heating in NFTs is discussed. PMID:25759907

  16. 103. ARAIII. Looking down into GCRE reactor pit as it ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    103. ARA-III. Looking down into GCRE reactor pit as it was being modified for further ML-1 testing. Shows bellows assembly, men working in pit, spiral staircase. May 20, 1965. Ineel photo no. 65-2762. Photographer: Farmer. - Idaho National Engineering Laboratory, Army Reactors Experimental Area, Scoville, Butte County, ID

  17. 241-AY-102 Leak Detection Pit Drain Line Inspection Report

    SciTech Connect

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

    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.

  18. 7 CFR 52.807 - Freedom from pits.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... United States Standards for Grades of Frozen Red Tart Pitted Cherries Factors of Quality § 52.807 Freedom... substantially free from any adhering sirup, sugar, or other packing medium. (c) (A) Classification. Frozen red... for this classification specified in Table I. (d) (B) Classification. Frozen red tart pitted...

  19. 7 CFR 52.807 - Freedom from pits.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... means pitted cherries that are substantially free from any adhering sirup, sugar, or other packing... may be present does not exceed the allowances for this classification specified in Table I. (d) (B... in Table I. (e) (C) Classification. Frozen red tart pitted cherries that are fairly free from...

  20. 7 CFR 52.807 - Freedom from pits.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... substantially free from any adhering sirup, sugar, or other packing medium. (c) (A) Classification. Frozen red... for this classification specified in Table I. (d) (B) Classification. Frozen red tart pitted cherries... pits that may be present does not exceed the number specified in Table I. (e) (C)...

  1. Modelling the mechanical behaviour of pit membranes in bordered pits with respect to cavitation resistance in angiosperms

    PubMed Central

    Tixier, Aude; Herbette, Stephane; Jansen, Steven; Capron, Marie; Tordjeman, Philippe; Cochard, Hervé; Badel, Eric

    2014-01-01

    Background and Aims Various correlations have been identified between anatomical features of bordered pits in angiosperm xylem and vulnerability to cavitation, suggesting that the mechanical behaviour of the pits may play a role. Theoretical modelling of the membrane behaviour has been undertaken, but it requires input of parameters at the nanoscale level. However, to date, no experimental data have indicated clearly that pit membranes experience strain at high levels during cavitation events. Methods Transmission electron microscopy (TEM) was used in order to quantify the pit micromorphology of four tree species that show contrasting differences in vulnerability to cavitation, namely Sorbus aria, Carpinus betulus, Fagus sylvatica and Populus tremula. This allowed anatomical characters to be included in a mechanical model that was based on the Kirchhoff–Love thin plate theory. A mechanistic model was developed that included the geometric features of the pits that could be measured, with the purpose of evaluating the pit membrane strain that results from a pressure difference being applied across the membrane. This approach allowed an assessment to be made of the impact of the geometry of a pit on its mechanical behaviour, and provided an estimate of the impact on air-seeding resistance. Key Results The TEM observations showed evidence of residual strains on the pit membranes, thus demonstrating that this membrane may experience a large degree of strain during cavitation. The mechanical modelling revealed the interspecific variability of the strains experienced by the pit membrane, which varied according to the pit geometry and the pressure experienced. The modelling output combined with the TEM observations suggests that cavitation occurs after the pit membrane has been deflected against the pit border. Interspecific variability of the strains experienced was correlated with vulnerability to cavitation. Assuming that air-seeding occurs at a given pit membrane

  2. Mapping sand and gravel pits in the Patuxent River watershed

    NASA Technical Reports Server (NTRS)

    Schmidt, T. J.; Witt, R. G.

    1981-01-01

    LANDSAT data from July 1973 and June 1978 for the Patuxent River Watershed of Maryland were processed in an effort to devise an economical method of monitoring the reclamation of sand and gravel pits. ASTEP-II and IDIMS software were utilized to derive signatures for sand and gravel pits and other land use/land cover types. Both unsupervised and supervised classifications of the two data sets were produced. Resultant statistics and color output products were compared in order to determine the extent of reclamation and expansion of sand and gravel pits over the five-year time span and to check the locations of more recent sand and gravel pits. Preliminary results indicate that, for a selected northern sub-acre, signatures derived for sand and gravel pits were nearly 90 percent accurate.

  3. Crevice and pitting corrosion behavior of stainless steels in seawater

    SciTech Connect

    Zaragoza-Ayala, A.E.; Orozco-Cruz, R.

    1999-11-01

    Pitting and crevice corrosion tests in natural seawater were performed on a series of stainless steels (i.e., S31603, N08904, S32304, S31803, S32520, N08925 and S31266) in order to determine their resistance to these types of localized corrosion. Open circuit potential (OCP) measurements for these alloys show for short exposure times an ennoblement in the OCP. After a certain time, occasional fall and rise in the OCP values was observed, which can be related to nucleation and repassivation of pits and/or crevices on the metal surface. Analysis of the electrochemical behavior and microscopic observations shows that only S31603 and S32304 alloys were susceptible to crevice and pitting corrosion, whereas the remaining alloys exhibited good resistance. Pitting potentials determined by the potentiodynamic technique also show S3 1603 and S32304 are susceptible to pitting corrosion under the experimental conditions used in this work.

  4. Microbial contents of soil from fire pits

    NASA Astrophysics Data System (ADS)

    Moon, K.; Esparza, V.; de Sandre, J.; Cheney, S.; Anderson, A.; White, M. A.

    2006-12-01

    Forest fires generate polycylic aromatic hydrocarbons (PAHs) that can lead to carcinogenic compounds, which are potential health risks. PAHs can be degraded to water and carbon dioxide by certain soil microbes. Thus, during participation in a NASA-funded summer research experience at Utah State University, our high school student team sampled soils from a month-old fire pit in which plant materials had been burnt. We detected in soil samples, from surface, 10 and 20 cm depths, microbes that would grow on a defined minimal medium source. Other microbes were cultured from the roots of plants that had established at the fire pit. A diversity of microbes was present in all samples based on visible differences in cell shape and color. It was surprising that the surface ash, although exposed to sunlight over the month interval, had culturable colonies. Many of these culturable bacteria were pigmented perhaps as a protection against UV radiation from the sun. We searched for genes in the microbes that encoded enzymes called dioxygenases that in other bacteria are involved in degradation of PAHs. This test involved using polymerase chain reactions to detect the genes. PCR products were found in two of the fifteen isolates tested although their sizes differed from the control gene product from a PAH-degrading mycobacterium isolate. These results suggest that the soils did contain microbes with the possible potential to alter the PAH compounds generated from vegetation fires. Our findings serve as a starting point for future studies looking at recovery and remediation of fired acreages.

  5. 37. ELECTRICAL PLAN AND DETAILS. SHOWS PLANNED LOCATION OF PORTABLE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    37. ELECTRICAL PLAN AND DETAILS. SHOWS PLANNED LOCATION OF PORTABLE GENERATOR. FUNCTION OF FOUR-FOOT SQUARE PIT IS SHOWN AS 'D.C. POWER SUPPLY PIT.' F.C. TORKELSON DRAWING NUMBER 842-ARVFS-701-E-1. INEL INDEX CODE NUMBER: 075 0701 10 851 151973. - Idaho National Engineering Laboratory, Advanced Reentry Vehicle Fusing System, Scoville, Butte County, ID

  6. A Topographic Analysis of Lunar Pit Craters Using LOLA

    NASA Astrophysics Data System (ADS)

    Malinski, P. T.; Milam, K. A.

    2014-12-01

    Pit craters have been a recent interest in the impact crater community due to their elusive formational mechanism(s) and their variable morphologies on different bodies. Pit craters have been observed on multiple planetary bodies and currently efforts are underway to characterize these crater types. In this work we focused on finding and evaluating pitted craters and their morphologic habits on the lunar surface to better constrain pit crater formation on a relatively dry body (compared to Mars and Ganymede). The study area ranged across the entire lunar surface from -20 to 50 degree latitudes and included both highland and maria terrains. The diameter range of the crater population evaluated was 20 - 60 km. The diameter range was chosen to include complex crater morphology (minimum diameter ~20 km) but to not include larger impacts (>60 km) to prevent misinterpretation of central regions. An overall population of 1490 craters were evaluated, of which 115 craters were characterized as pit craters. The LOLA data set along with NAC+WAC, Clementine visible imagery were used to locate and assess the pit craters in addition to generated digital elevation models of the craters. Our results show that pitted craters have variable morphologies, where the pitted features could be oblique or linear in shape. Summit and floor pit craters were found in both maria and highland terrain. The Moran index and Chi statistical tests were applied and determined that the population is randomly distributed across the study area. Evaluation of the individual pit craters show that they may potentially have one or more formational mechanisms associated. The statistical tests coupled with the variant morphologies may indicate multiple relations to possible formational mechanisms (volcanic, volatile release, or structural deformation).

  7. Lunar Pit Craters Presumed to be the Entrances of Lava Caves by Analogy to the Earth Lava Tube Pits

    NASA Astrophysics Data System (ADS)

    Hong, Ik-Seon; Yi, Yu; Kim, Eojin

    2014-06-01

    Lava caves could be useful as outposts for the human exploration of the Moon. Lava caves or lava tubes are formed when the external surface of the lava flows cools more quickly to make a hardened crust over subsurface lava flows. The lava flow eventually ceases and drains out of the tube, leaving an empty space. The frail part of the ceiling of lava tube could collapse to expose the entrance to the lava tubes which is called a pit crater. Several pit craters with the diameter of around 100 meters have been found by analyzing the data of SELENE and LRO lunar missions. It is hard to use these pit craters for outposts since these are too large in scale. In this study, small scale pit craters which are fit for outposts have been investigated using the NAC image data of LROC. Several topographic patterns which are believed to be lunar caves have been found and the similar pit craters of the Earth were compared and analyzed to identify caves. For this analysis, the image data of satellites and aerial photographs are collected and classified to construct a database. Several pit craters analogous to lunar pit craters were derived and a morphological pit crater model was generated using the 3D printer based on this database.

  8. Method for Identifying Lava Tubes Among Pit Craters Using Brightness Profile Across Pits on the Moon or Mars

    NASA Astrophysics Data System (ADS)

    Jung, Jongil; Hong, Ik-Seon; Cho, Eunjin; Yi, Yu

    2016-03-01

    Caves can serve as major outposts for future human exploration of the Moon and Mars. In addition, caves can protect people and electronic equipment from external hazards such as cosmic ray radiation and meteorites impacts and serve as a shelter. Numerous pit craters have been discovered on the Moon and Mars and are potential entrances to caves; the principal topographic features of pit craters are their visible internal floors and pits with vertical walls. We have devised two topographical models for investigating the relationship between the topographical characteristics and the inner void of pit craters. One of our models is a concave floor void model and the other is a convex floor tube model. For each model, optical photographs have been obtained under conditions similar to those in which optical photographs have been acquired for craters on the Moon and Mars. Brightness profiles were analyzed for determining the profile patterns of the void pit craters. The profile patterns were compared to the brightness profiles of Martian pit craters, because no good-quality images of lunar pit craters were available. In future studies, the model profile patterns will be compared to those of lunar pit craters, and the proposed method will likely become useful for finding lunar caves and consequently for planning lunar bases for manned lunar expeditions.

  9. Suppression of self-heating effect in AlGaN/GaN high electron mobility transistors by substrate-transfer technology using h-BN

    SciTech Connect

    Hiroki, Masanobu Kumakura, Kazuhide; Kobayashi, Yasuyuki; Akasaka, Tetsuya; Makimoto, Toshiki; Yamamoto, Hideki

    2014-11-10

    We fabricated AlGaN/GaN high electron mobility transistors (HEMTs) on h-BN/sapphire substrates and transferred them from the host substrates to copper plates using h-BN as a release layer. In current–voltage characteristics, the saturation drain current decreased by about 30% under a high-bias condition before release by self-heating effect. In contrast, after transfer, the current decrement was as small as 8% owing to improved heat dissipation: the device temperature increased to 50 °C in the as-prepared HEMT, but only by several degrees in the transferred HEMT. An effective way to improve AlGaN/GaN HEMT performance by a suppression of self-heating effect has been demonstrated.

  10. Self-heating probe instrument and method for measuring high temperature melting volume change rate of material

    NASA Astrophysics Data System (ADS)

    Wang, Junwei; Wang, Zhiping; Lu, Yang; Cheng, Bo

    2013-03-01

    The castings defects are affected by the melting volume change rate of material. The change rate has an important effect on running safety of the high temperature thermal storage chamber, too. But the characteristics of existing measuring installations are complex structure, troublesome operation and low precision. In order to measure the melting volume change rate of material accurately and conveniently, a self-designed measuring instrument, self-heating probe instrument, and measuring method are described. Temperature in heating cavity is controlled by PID temperature controller; melting volume change rate υ and molten density are calculated based on the melt volume which is measured by the instrument. Positive and negative υ represent expansion and shrinkage of the sample volume after melting, respectively. Taking eutectic LiF+CaF2 for example, its melting volume change rate and melting density at 1 123 K are -20.6% and 2 651 kg·m-3 measured by this instrument, which is only 0.71% smaller than literature value. Density and melting volume change rate of industry pure aluminum at 973 K and analysis pure NaCl at 1 123 K are detected by the instrument too. The measure results are agreed with report values. Measuring error sources are analyzed and several improving measures are proposed. In theory, the measuring errors of the change rate and molten density which are measured by the self-designed instrument is nearly 1/20-1/50 of that measured by the refitted mandril thermal expansion instrument. The self-designed instrument and method have the advantages of simple structure, being easy to operate, extensive applicability for material, relatively high accuracy, and most importantly, temperature and sample vapor pressure have little effect on the measurement accuracy. The presented instrument and method solve the problems of complicated structure and procedures, and large measuring errors for the samples with high vapor pressure by existing installations.

  11. Investigating oiled birds from oil field waste pits

    SciTech Connect

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

    1991-10-01

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

  12. 41. THE BEAR PIT (OLD SIDE DINING ROOM). THE ETCHINGS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    41. THE BEAR PIT (OLD SIDE DINING ROOM). THE ETCHINGS ON THE CEILING BEAMS AND COLUMNS OF PARK WILDLIFE ARE ORIGINAL TO THE OLD SIDE DINING ROOM. THE SIDE DINING ROOM WAS DESIGNED AND BUILT BY ROBERT REAMER IN 1927. IN 1962 WHEN IT WAS CONVERTED INTO THE BEAR PIT A WALL WAS ADDED BETWEEN THE THREE COLUMNS THAT SEPARATE THIS ROOM FROM THE MAIN DINING ROOM. THE ORIGINAL BEAR PIT ETCHINGS DEPICTING BEARS TENDING BAR AND PLAYING THE PIANO WERE MOUNTED ON THE WALL BETWEEN THE COLUMNS. - Old Faithful Inn, 900' northeast of Snowlodge & 1050' west of Old Faithful Lodge, Lake, Teton County, WY

  13. The effects of a dredge excavation pit on benthic macrofauna in offshore Louisiana.

    PubMed

    Palmer, Terence A; Montagna, Paul A; Nairn, Robert B

    2008-04-01

    Over two years after the original creation of a sand excavation pit 8 km off the Louisiana coast, benthic macrofauna communities and sedimentary characteristics are still effected. Macrofaunal communities inside the pit had lower abundance, biomass, and diversity than communities outside the pit. This difference, however, was only significant with some of the stations outside the pit. Results from multi-dimensional scaling and cluster analysis showed that macrofaunal communities were less than 32% similar inside the pit to communities outside the pit. The polychaete Mediomastus ambiseta was the most abundant species outside the excavation pit, but the species was only counted once inside the pit. The most dominant species, which made up over 90% of organisms inside the pit, was the pioneer polychaete Paraprionospio pinnata. Only three species were found at each station inside the pit as opposed to 9-27 species at stations outside the pit. All species inside the pit were also found outside the pit; thus, change was due to a loss of species rather than replacement by different species. Sediment inside the pit contained more silt and clay; however, no difference in water quality was detected compared with outside the pit. Hurricanes Katrina and Rita passed near the dredge pit in 2005 and could have effected sediment transport in the region. Because the macrofaunal community inside the pit has not recovered within 38 months, it is likely that it will require more time before it resembles the surrounding conditions.

  14. The Effects of a Dredge Excavation Pit on Benthic Macrofauna in Offshore Louisiana

    NASA Astrophysics Data System (ADS)

    Palmer, Terence A.; Montagna, Paul A.; Nairn, Robert B.

    2008-04-01

    Over two years after the original creation of a sand excavation pit 8 km off the Louisiana coast, benthic macrofauna communities and sedimentary characteristics are still effected. Macrofaunal communities inside the pit had lower abundance, biomass, and diversity than communities outside the pit. This difference, however, was only significant with some of the stations outside the pit. Results from multi-dimensional scaling and cluster analysis showed that macrofaunal communities were less than 32% similar inside the pit to communities outside the pit. The polychaete Mediomastus ambiseta was the most abundant species outside the excavation pit, but the species was only counted once inside the pit. The most dominant species, which made up over 90% of organisms inside the pit, was the pioneer polychaete Paraprionospio pinnata. Only three species were found at each station inside the pit as opposed to 9-27 species at stations outside the pit. All species inside the pit were also found outside the pit; thus, change was due to a loss of species rather than replacement by different species. Sediment inside the pit contained more silt and clay; however, no difference in water quality was detected compared with outside the pit. Hurricanes Katrina and Rita passed near the dredge pit in 2005 and could have effected sediment transport in the region. Because the macrofaunal community inside the pit has not recovered within 38 months, it is likely that it will require more time before it resembles the surrounding conditions.

  15. Retaining latch for a water pit gate

    DOEpatents

    Beale, Arden R.

    1997-01-01

    A retaining latch for use in a hazardous materials storage or handling facility to adjustably retain a water pit gate in a gate frame. A retaining latch is provided comprising a latch plate which is rotatably mounted to each end of the top of the gate and a recessed opening, formed in the gate frame, for engaging an edge of the latch plate. The latch plate is circular in profile with one side cut away or flat, such that the latch plate is D-shaped. The remaining circular edge of the latch plate comprises steps of successively reduced thickness. The stepped edge of the latch plate fits inside a recessed opening formed in the gate frame. As the latch plate is rotated, alternate steps of the latch plate are engaged by the recessed opening. When the latch plate is rotated such that the flat portion of the latch plate faces the recessed opening in the gate frame, there is no connection between the opening and the latch plate and the gate is unlatched from the gate frame.

  16. Retaining latch for a water pit gate

    DOEpatents

    Beale, A.R.

    1997-11-18

    A retaining latch is described for use in a hazardous materials storage or handling facility to adjustably retain a water pit gate in a gate frame. A retaining latch is provided comprising a latch plate which is rotatably mounted to each end of the top of the gate and a recessed opening, formed in the gate frame, for engaging an edge of the latch plate. The latch plate is circular in profile with one side cut away or flat, such that the latch plate is D-shaped. The remaining circular edge of the latch plate comprises steps of successively reduced thickness. The stepped edge of the latch plate fits inside a recessed opening formed in the gate frame. As the latch plate is rotated, alternate steps of the latch plate are engaged by the recessed opening. When the latch plate is rotated such that the flat portion of the latch plate faces the recessed opening in the gate frame, there is no connection between the opening and the latch plate and the gate is unlatched from the gate frame. 4 figs.

  17. 15. INTERIOR, INSPECTION PITS, OVERHEAD CATWALKS AND OVERHEAD CRANE SUPPORT, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. INTERIOR, INSPECTION PITS, OVERHEAD CATWALKS AND OVERHEAD CRANE SUPPORT, FACING WEST - Delaware, Lackawanna & Western Railroad Freight & Rail Yard, Multiple Unit Light Inspection Shed, New Jersey Transit Hoboken Terminal Rail Yard, Hoboken, Hudson County, NJ

  18. 14. INTERIOR, INSPECTION PITS AND OVERHEAD CATWALKS, FACING WEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. INTERIOR, INSPECTION PITS AND OVERHEAD CATWALKS, FACING WEST - Delaware, Lackawanna & Western Railroad Freight & Rail Yard, Multiple Unit Light Inspection Shed, New Jersey Transit Hoboken Terminal Rail Yard, Hoboken, Hudson County, NJ

  19. 17. INTERIOR, INSPECTION PITS, OVERHEAD CRANE SUPPORT AND CAR JACKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. INTERIOR, INSPECTION PITS, OVERHEAD CRANE SUPPORT AND CAR JACKING PADS, FACING EAST - Delaware, Lackawanna & Western Railroad Freight & Rail Yard, Multiple Unit Light Inspection Shed, New Jersey Transit Hoboken Terminal Rail Yard, Hoboken, Hudson County, NJ

  20. 18. LOOKING EAST AT THE HOT METAL RELADLING PIT No. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. LOOKING EAST AT THE HOT METAL RELADLING PIT No. 1 ON THE CHARGING AISLE OF THE BOP SHOP. - U.S. Steel Duquesne Works, Basic Oxygen Steelmaking Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  1. 24. SOUTHEAST VIEW OF LADLE REPAIR PIT ON THE WESTERN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    24. SOUTHEAST VIEW OF LADLE REPAIR PIT ON THE WESTERN TEEMING AISLE OF THE BOP SHOP. LOOKING SOUTHEAST. - U.S. Steel Duquesne Works, Basic Oxygen Steelmaking Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  2. CONSTRUCTION PROGRESS PHOTO SHOWING EXCAVATION PIT FOR MAIN PROCESSING BUILDING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    CONSTRUCTION PROGRESS PHOTO SHOWING EXCAVATION PIT FOR MAIN PROCESSING BUILDING (CPP-601) LOOKING SOUTH. INL PHOTO NUMBER NRTS-50-693. Unknown Photographer, 1950 - Idaho National Engineering Laboratory, Idaho Chemical Processing Plant, Fuel Reprocessing Complex, Scoville, Butte County, ID

  3. Molten salt corrosion of SiC: Pitting mechanism

    NASA Technical Reports Server (NTRS)

    Jacobson, N. S.; Smialek, J. L.

    1985-01-01

    Thin films of Na2SO4 and Na2CO3 at 1000 C lead to severe pitting of sintered alpha-SiC. These pits are important as they cause a strength reduction in this material. The growth of product layers is related to pit formation for the Na2CO3 case. The early reaction stages involve repeated oxidation and dissolution to form sodium silicate. This results in severe grain boundary attack. After this a porous silica layer forms between the sodium silicate melt and the SiC. The pores in this layer appear to act as paths for the melt to reach the SiC and create larger pits.

  4. 105-KW Sandfilter Backwash Pit sludge volume calculation

    SciTech Connect

    Dodd, E.N. Jr.

    1995-02-10

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

  5. 23. Closer perspective view from the southwest. An archaeological pit ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    23. Closer perspective view from the southwest. An archaeological pit is located under the center first-floor window. - John Bartram House & Garden, House, 54th Street & Lindbergh Boulevard, Philadelphia, Philadelphia County, PA

  6. 16. Detail of drainage pits inside east half (1892 part) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. Detail of drainage pits inside east half (1892 part) of main section of roundhouse. View to southeast. - Duluth & Iron Range Rail Road Company Shops, Roundhouse, Southwest of downtown Two Harbors, northwest of Agate Bay, Two Harbors, Lake County, MN

  7. 22. VIEW SOUTH, INTERIOR OF SOUTH PIT, SHOWING FINAL STEP ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. VIEW SOUTH, INTERIOR OF SOUTH PIT, SHOWING FINAL STEP IN GEARING THAT DRIVES OPERATING WHEEL, WITH HYDRAULIC SHAFT BRAKE - Mystic River Bridge, Spanning Mystic River at U.S. Route 1, Groton, New London County, CT

  8. Pit latrine effluent infiltration into groundwater: the Epworth case study.

    PubMed

    Chidavaenzi, M; Bradley, M; Jere, M; Nhandara, C

    2000-01-01

    Water can be a vehicle for the transmission of communicable diseases. Technologies have been developed to protect groundwater from external surface contamination. However, there is growing concern about the likelihood of pit latrine effluent infiltrating into groundwater reservoirs for well water supply systems. Investigations on seasonal variations and extent of pit latrine effluent infiltration into soil and groundwater have been carried out in Zimbabwe. Preliminary results show that groundwater flows in the direction of surface runoff, and that there is no lateral soil pollution above the groundwater surface. Pit latrine contents leach downwards and down slopes for distances that vary per season and soil type. The results also demonstrate the contribution of refuse pits and water collection methods to groundwater pollution.

  9. BARBEQUE PIT AND PLAYHOUSE IN (REAR) YARD, LOOKING SOUTH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    BARBEQUE PIT AND PLAYHOUSE IN (REAR) YARD, LOOKING SOUTH - Irvine Ranch Agricultural Headquarters, Carillo Tenant House, Southwest of Intersection of San Diego & Santa Ana Freeways, Irvine, Orange County, CA

  10. CHICKEN COOP BEHIND FENCED YARD AND (REAR) OF BARBEQUE PIT, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    CHICKEN COOP BEHIND FENCED YARD AND (REAR) OF BARBEQUE PIT, LOOKING NORTH - Irvine Ranch Agricultural Headquarters, Carillo Tenant House, Southwest of Intersection of San Diego & Santa Ana Freeways, Irvine, Orange County, CA

  11. 13. VIEW OF BARBECUE PIT, FACING EAST. (BUILDING 132 IS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. VIEW OF BARBECUE PIT, FACING EAST. (BUILDING 132 IS IN BACKGROUND ON RIGHT.) - Fort McPherson, World War II Station Hospital, Structures, Bordered by Hardee & Thorne Avenues & Howe Street, Atlanta, Fulton County, GA

  12. 54. Photocopied August 1978. INTERIOR OF A TAIL PIT OR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    54. Photocopied August 1978. INTERIOR OF A TAIL PIT OR TAIL RACE AT THE EAST END OF THE POWER HOUSE, SEPTEMBER 17, 1900. THE PRE-MOULDED BLOCKS WHICH FORMED THE SIDE WALLS AND THE ARCHED FOREBAY WALL ARE CLEARLY VISIBLE. THE MONOLITHIC FLOOR OF THE TAIL PIT, HOWEVER, HAS NOT YET BEEN POURED: NEITHER HAS THE MONOLITHIC ARCHED ROOF. (75) - Michigan Lake Superior Power Company, Portage Street, Sault Ste. Marie, Chippewa County, MI

  13. Pitting of stainless steel in an emergency service water system

    SciTech Connect

    Morgan, D.J.; Willertz, L.E.

    1994-12-31

    Pitting of AISI 321 grade stainless steel flex-hoses in an emergency service water system has been experienced recently, after 13 years of successful service. Failures of new hoses have occurred in as little as 4 months. This paper presents the authors analysis of the failures and discusses the primary suspected mechanisms, underdeposit pitting and microbiologically influenced corrosion (MIC). It also presents their approach for investigating suspected causes and developing an integrated plan to minimize its recurrence.

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

    PubMed

    Lee, Jinkee; Holbrook, N Michele; Zwieniecki, Maciej A

    2012-01-01

    Ion-mediated changes in xylem hydraulic resistance are hypothesized to result from hydrogel like properties of pectins located in the bordered pit membranes separating adjacent xylem vessels. Although the kinetics of the ion-mediated changes in hydraulic resistance are consistent with the swelling/deswelling behavior of pectins, there is no direct evidence of this activity. In this report we use atomic force microscopy (AFM) to investigate structural changes in bordered pit membranes associated with changes in the ionic concentration of the surrounding solution. When submerged in de-ionized water, AFM revealed bordered pit membranes as relatively smooth, soft, and lacking any sharp edges surface, 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 and elevation features. Specifically, bordered pit membranes became harder and the fiber edges were clearly visible. In addition, the membrane contracted and appeared much rougher due to exposed microfibers. In neither solution was there any evidence of discrete pores through the membrane whose dimensions were altered in response to the ionic composition of the surrounding solution. Instead the variable hydraulic resistance appears to involve changes in the both the permeability and the thickness of the pit membrane.

  15. Corrosion pitting and environmentally assisted small crack growth

    PubMed Central

    Turnbull, Alan

    2014-01-01

    In many applications, corrosion pits act as precursors to cracking, but qualitative and quantitative prediction of damage evolution has been hampered by lack of insights into the process by which a crack develops from a pit. An overview is given of recent breakthroughs in characterization and understanding of the pit-to-crack transition using advanced three-dimensional imaging techniques such as X-ray computed tomography and focused ion beam machining with scanning electron microscopy. These techniques provided novel insights with respect to the location of crack development from a pit, supported by finite-element analysis. This inspired a new concept for the role of pitting in stress corrosion cracking based on the growing pit inducing local dynamic plastic strain, a critical factor in the development of stress corrosion cracks. Challenges in quantifying the subsequent growth rate of the emerging small cracks are then outlined with the potential drop technique being the most viable. A comparison is made with the growth rate for short cracks (through-thickness crack in fracture mechanics specimen) and long cracks and an electrochemical crack size effect invoked to rationalize the data. PMID:25197249

  16. Corrosion pitting and environmentally assisted small crack growth.

    PubMed

    Turnbull, Alan

    2014-09-01

    In many applications, corrosion pits act as precursors to cracking, but qualitative and quantitative prediction of damage evolution has been hampered by lack of insights into the process by which a crack develops from a pit. An overview is given of recent breakthroughs in characterization and understanding of the pit-to-crack transition using advanced three-dimensional imaging techniques such as X-ray computed tomography and focused ion beam machining with scanning electron microscopy. These techniques provided novel insights with respect to the location of crack development from a pit, supported by finite-element analysis. This inspired a new concept for the role of pitting in stress corrosion cracking based on the growing pit inducing local dynamic plastic strain, a critical factor in the development of stress corrosion cracks. Challenges in quantifying the subsequent growth rate of the emerging small cracks are then outlined with the potential drop technique being the most viable. A comparison is made with the growth rate for short cracks (through-thickness crack in fracture mechanics specimen) and long cracks and an electrochemical crack size effect invoked to rationalize the data. PMID:25197249

  17. PIT tags increase effectiveness of freshwater mussel recaptures

    USGS Publications Warehouse

    Kurth, J.; Loftin, C.; Zydlewski, J.; Rhymer, J.

    2007-01-01

    Translocations are used increasingly to conserve populations of rare freshwater mussels. Recovery of translocated mussels is essential to accurate assessment of translocation success. We designed an experiment to evaluate the use of passive integrated transponder (PIT) tags to mark and track individual freshwater mussels. We used eastern lampmussels (Lampsilis radiata radiata) as a surrogate for 2 rare mussel species. We assessed internal and external PIT-tag retention in the laboratory and field. Internal tag retention was high (75-100%), and tag rejection occurred primarily during the first 3 wk after tagging. A thin layer of nacre coated internal tags 3 to 4 mo after insertion, suggesting that long-term retention is likely. We released mussels with external PIT tags at 3 field study sites and recaptured them with a PIT pack (mobile interrogation unit) 8 to 10 mo and 21 to 23 mo after release. Numbers of recaptured mussels differed among study sites; however, we found more tagged mussels with the PIT-pack searches with visual confirmation (72-80%) than with visual searches alone (30-47%) at all sites. PIT tags offer improved recapture of translocated mussels and increased accuracy of posttranslocation monitoring. ?? 2007 by The North American Benthological Society.

  18. Role of chicken Pit-1 isoforms in activating growth hormone gene.

    PubMed

    Murase, Daisuke; Taniuchi, Shusuke; Takeuchi, Sakae; Adachi, Hiromi; Kansaku, Norio; Okazaki, Katsuichiro; Ohkubo, Takeshi

    2011-09-01

    In the present study, we expressed chicken (ch) Pit-1α (chPit-1α) and chPit-1γin vitro to compare the roles of chPit-1s in the transcription of the chicken growth hormone (chGH) gene. Both green fluorescence protein (GFP)-fused chPit-1γ and GFP-fused chPit-1α were localized in the nuclei of COS-7 cells. In a luciferase reporter gene assay, both chPit-1α and chPit-1γ transactivated the chGH promoter, and chPit-1α showed a more potent effect than chPit-1γ. On the other hand, an increase of cellular cAMP induced by forskolin promoted transactivation of the chGH gene with chPit-1α and chPit-1γ to similar extents. These results suggest that chPit-1γ may modulate the basal promoter activity of the chGH gene to the same degree as chPit-1α; however, a structural difference observed at the N-terminus transactivation domains in chPit-1α and chPit-1γ could be associated with the efficiency of basal activation of the chGH promoter. PMID:21703269

  19. 7 CFR 52.802 - Grades of frozen red tart pitted cherries.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Grades of frozen red tart pitted cherries. 52.802... of Frozen Red Tart Pitted Cherries Product Description and Grades § 52.802 Grades of frozen red tart pitted cherries. (a) “U.S. Grade A” (or “U.S. Fancy”) is the quality of frozen red tart pitted...

  20. 7 CFR 52.802 - Grades of frozen red tart pitted cherries.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Grades of frozen red tart pitted cherries. 52.802... of Frozen Red Tart Pitted Cherries Product Description and Grades § 52.802 Grades of frozen red tart pitted cherries. (a) “U.S. Grade A” (or “U.S. Fancy”) is the quality of frozen red tart pitted...

  1. One dimensional Linescan x-ray detection of pits in fresh cherries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The presence of pits in processed cherries is a concern for both processors and consumers, in many cases causing injury and potential lawsuits. While machines used for pitting cherries are extremely efficient, if one or more plungers in a pitting head become misaligned, a large number of pits may p...

  2. Real-time methods for non-destructive detection of pits in fresh cherries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The presence of pits in processed cherries is a concern for both processors and consumers, in many cases causing injury and potential lawsuits. While machines used for pitting cherries are extremely efficient, if one or more plungers in a pitting head become misaligned, a large number of pits may p...

  3. Multiphysics Modeling for Dimensional Analysis of a Self-Heated Molten Regolith Electrolysis Reactor for Oxygen and Metals Production on the Moon and Mars

    NASA Technical Reports Server (NTRS)

    Dominguez, Jesus A.; Sibille, Laurent

    2010-01-01

    The technology of direct electrolysis of molten lunar regolith to produce oxygen and molten metal alloys has progressed greatly in the last few years. The development of long-lasting inert anodes and cathode designs as well as techniques for the removal of molten products from the reactor has been demonstrated. The containment of chemically aggressive oxide and metal melts is very difficult at the operating temperatures ca 1600 C. Containing the molten oxides in a regolith shell can solve this technical issue and can be achieved by designing a self-heating reactor in which the electrolytic currents generate enough Joule heat to create a molten bath. In a first phase, a thermal analysis model was built to study the formation of a melt of lunar basaltic regolith irradiated by a focused solar beam This mode of heating was selected because it relies on radiative heat transfer, which is the dominant mode of transfer of energy in melts at 1600 C. Knowing and setting the Gaussian-type heat flux from the concentrated solar beam and the phase and temperature dependent thermal properties, the model predicts the dimensions and temperature profile of the melt. A validation of the model is presented in this paper through the experimental formation of a spherical cap melt realized by others. The Orbitec/PSI experimental setup uses an 3.6-cm diameter concentrated solar beam to create a hemispheric melt in a bed of lunar regolith simulant contained in a large pot. Upon cooling, the dimensions of the vitrified melt are measured to validate the thermal model. In a second phase, the model is augmented by multiphysics components to compute the passage of electrical currents between electrodes inserted in the molten regolith. The current through the melt generates Joule heating due to the high resistivity of the medium and this energy is transferred into the melt by conduction, convection and primarily by radiation. The model faces challenges in two major areas, the change of phase as

  4. Nobody’s perfect: can irregularities in pit structure influence vulnerability to cavitation?

    PubMed Central

    Plavcová, Lenka; Jansen, Steven; Klepsch, Matthias; Hacke, Uwe G.

    2013-01-01

    Recent studies have suggested that species-specific pit properties such as pit membrane thickness, pit membrane porosity, torus-to-aperture diameter ratio and pit chamber depth influence xylem vulnerability to cavitation. Despite the indisputable importance of using mean pit characteristics, considerable variability in pit structure within a single species or even within a single pit field should be acknowledged. According to the rare pit hypothesis, a single pit that is more air-permeable than many neighboring pits is sufficient to allow air-seeding. Therefore, any irregularities or morphological abnormalities in pit structure allowing air-seeding should be associated with increased vulnerability to cavitation. Considering the currently proposed models of air-seeding, pit features such as rare, large pores in the pit membrane, torus extensions, and plasmodesmatal pores in a torus can represent potential glitches. These aberrations in pit structure could either result from inherent developmental flaws, or from damage caused to the pit membrane by chemical and physical agents. This suggests the existence of interesting feedbacks between abiotic and biotic stresses in xylem physiology. PMID:24273549

  5. Multiphysics Modeling for Dimensional Analysis of a Self-Heated Molten Regolith Electrolysis Reactor for Oxygen and Metals Production on the Moon and Mars

    NASA Technical Reports Server (NTRS)

    Dominguez, Jesus; Sibille, Laurent

    2010-01-01

    The technology of direct electrolysis of molten lunar regolith to produce oxygen and molten metal alloys has progressed greatly in the last few years. The development of long-lasting inert anodes and cathode designs as well as techniques for the removal of molten products from the reactor has been demonstrated. The containment of chemically aggressive oxide and metal melts is very difficult at the operating temperatures ca. 1600 C. Containing the molten oxides in a regolith shell can solve this technical issue and can be achieved by designing a self-heating reactor in which the electrolytic currents generate enough Joule heat to create a molten bath.

  6. Evaporative respiratory cooling augments pit organ thermal detection in rattlesnakes.

    PubMed

    Cadena, Viviana; Andrade, Denis V; Bovo, Rafael P; Tattersall, Glenn J

    2013-12-01

    Rattlesnakes use their facial pit organs to sense external thermal fluctuations. A temperature decrease in the heat-sensing membrane of the pit organ has the potential to enhance heat flux between their endothermic prey and the thermal sensors, affect the optimal functioning of thermal sensors in the pit membrane and reduce the formation of thermal "afterimages", improving thermal detection. We examined the potential for respiratory cooling to improve strike behaviour, capture, and consumption of endothermic prey in the South American rattlesnake, as behavioural indicators of thermal detection. Snakes with a higher degree of rostral cooling were more accurate during the strike, attacking warmer regions of their prey, and relocated and consumed their prey faster. These findings reveal that by cooling their pit organs, rattlesnakes increase their ability to detect endothermic prey; disabling the pit organs caused these differences to disappear. Rattlesnakes also modify the degree of rostral cooling by altering their breathing pattern in response to biologically relevant stimuli, such as a mouse odour. Our findings reveal that low humidity increases their ability to detect endothermic prey, suggesting that habitat and ambush site selection in the wild may be influenced by external humidity levels as well as temperature.

  7. Stochastic nature of clathrin-coated pit assembly

    NASA Astrophysics Data System (ADS)

    Banerjee, Anand; Berezhkovskii, Alexander; Nossal, Ralph

    2013-03-01

    Clathrin-mediated endocytosis is a complex process through which eukaryotic cells internalize various macromolecules (cargo). The process occurs via the formation of invaginations on the cell membrane, called clathrin-coated pits (CCPs). The dynamics of CCP formation shows remarkable variability. After initiation, a fraction of CCPs, called ``productive pits'', bind to cargo and then grow and mature into clathrin-coated vesicles (CCVs). In contrast, a large fraction of CCPs, called ``abortive pits'', fail to bind to cargo, grow only up to intermediate sizes and then disassemble. There is notable heterogeneity in the lifetimes of both productive and abortive pits. We propose a stochastic model of CCP dynamics to explain these experimental observations. Our model includes a kinetic scheme for CCP assembly and a related functional form for the dependence of free energy of a CCP on its size. Using this model, we calculate the lifetime distribution of abortive pits (via Monte Carlo simulation) and show that the distribution fits experimental data very well. By fitting the data we determine the free energy of CCP formation and show that CCPs without cargo are energetically unstable. We also suggest a mechanism by which cargo binding stabilizes CCPs and facilitates their growth.

  8. Dissolution kinetics and etch pit studies of potassium aluminium sulphate

    NASA Astrophysics Data System (ADS)

    van der Hoek, B.; Van Enckevort, W. J. P.; Van Der Linden, W. H.

    1983-03-01

    The dissolution process of the {111} faces of potash alum is studied, both by microtopographic examinations of the etch pit patterns and by measurement of the dissolution kinetics in a rotating disc crystallizer. Both methods showed that the Cabrera-Levine dissolution theory holds for the two most common dislocation types ending on the {111} faces of potash alum. On the basis of the rotating disc experiments, the interfacial supersaturation of the etch pit experiments was roughly estimated. Using this, it was found that at interfacial supersaturations below -0.6% (dislocations with <110> Burgers vector) or below -0.85% (dislocations with <100> Burgers vector) numerous etch pits related to those dislocation types appeared. Below those undersaturations the dissolution process is mainly determined by volume diffusion. From the critical undersaturation, determined in the rotating disc crystallizer, the value of the edge free energy of a step was found to be approximately 0.01 J/m 2.

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

    SciTech Connect

    Atencio, B.P.

    1994-06-01

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

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

    SciTech Connect

    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.

  11. Fukushima Nuclear Accident Recorded in Tibetan Plateau Snow Pits

    PubMed Central

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

    2015-01-01

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

  12. Comparative treatment effectiveness of conventional trench and seepage pit systems.

    PubMed

    Field, J P; Farrell-Poe, K L; Walworth, J L

    2007-03-01

    On-site wastewater treatment systems can be a potential source of groundwater contamination in regions throughout the United States and other parts of the world. Here, we evaluate four conventional trench systems and four seepage pit systems to determine the relative effectiveness of these systems for the treatment of septic tank effluent in medium- to coarse-textured arid and semiarid soils. Soil borings were advanced up to twice the depth of the trenches (4 m) and seepage pits (15 m) at two horizontal distances (30 cm and 1.5 m) from the sidewalls of the systems. Soil samples were analyzed for various biological and chemical parameters, including Escherichia coli, total coliform, pH, total organic carbon, total dissolved solids, total nitrogen, ammonium-nitrogen, and nitrate-nitrogen. Most soil parameters investigated approached background levels more rapidly near the trenches than the seepage pits, as sampling distance increased both vertically and horizontally from the sidewalls of the systems.

  13. Pit Distribution Design for Computer-Generated Waveguide Holography

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

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

    2015-01-01

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

  15. Electric-field dependence of electron drift velocity in 4H-SiC

    NASA Astrophysics Data System (ADS)

    Ivanov, P. A.; Potapov, A. S.; Samsonova, T. P.; Grekhov, I. V.

    2016-09-01

    Room temperature isothermal forward current-voltage characteristics of mesa-epitaxial 4H-SiC Schottky diodes were measured at high electric fields (beyond 105 V/cm) in the 34-μm thick n-base doped at 1 × 1015 cm-3. The effect of diode self-heating on current was minimized when using single 4-ns pulses. The analytical formula was derived for the dependence of electron drift velocity on electric field along c-axis.

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

    PubMed Central

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

    2014-01-01

    Purpose. Albinism is associated with disrupted foveal development, though intersubject variability is becoming appreciated. We sought to quantify this variability, and examine the relationship between foveal cone specialization and pit morphology in patients with a clinical diagnosis of albinism. Methods. We recruited 32 subjects with a clinical diagnosis of albinism. DNA was obtained from 25 subjects, and known albinism genes were analyzed for mutations. Relative inner and outer segment (IS and OS) lengthening (fovea-to-perifovea ratio) was determined from manually segmented spectral domain-optical coherence tomography (SD-OCT) B-scans. Foveal pit morphology was quantified for eight subjects from macular SD-OCT volumes. Ten subjects underwent imaging with adaptive optics scanning light ophthalmoscopy (AOSLO), and cone density was measured. Results. We found mutations in 22 of 25 subjects, including five novel mutations. All subjects lacked complete excavation of inner retinal layers at the fovea, though four subjects had foveal pits with normal diameter and/or volume. Peak cone density and OS lengthening were variable and overlapped with that observed in normal controls. A fifth hyper-reflective band was observed in the outer retina on SD-OCT in the majority of the subjects with albinism. Conclusions. Foveal cone specialization and pit morphology vary greatly in albinism. Normal cone packing was observed in the absence of a foveal pit, suggesting a pit is not required for packing to occur. The degree to which retinal anatomy correlates with genotype or visual function remains unclear, and future examination of larger patient groups will provide important insight on this issue. PMID:24845642

  17. Upper Extremity Injuries in NASCAR Drivers and Pit Crew

    PubMed Central

    Wertman, Gary; Gaston, R. Glenn; Heisel, William

    2016-01-01

    Background: Understanding the position-specific musculoskeletal forces placed on the body of athletes facilitates treatment, prevention, and return-to-play decisions. While position-specific injuries are well documented in most major sports, little is known about the epidemiology of position-specific injuries in National Association for Stock Car Automobile Racing (NASCAR) drivers and pit crew. Purpose: To investigate position-specific upper extremity injuries in NASCAR drivers and pit crew members. Study Design: Descriptive epidemiological study. Methods: A retrospective chart review was performed to assess position-specific injuries in NASCAR drivers and pit crew members. Included in the study were patients seen by a single institution between July 2003 and October 2014 with upper extremity injuries from race-related NASCAR events or practices. Charts were reviewed to identify the diagnosis, mechanism of injury, and position of each patient. Results: A total of 226 NASCAR team members were treated between July 2003 and October 2014. Of these, 118 injuries (52%) occurred during NASCAR racing events or practices. The majority of these injuries occurred in NASCAR changers (42%), followed by injuries in drivers (16%), carriers (14%), jack men (11%), fuel men (9%), and utility men (8%). The majority of the pit crew positions are at risk for epicondylitis, while drivers are most likely to experience neuropathies, such as hand-arm vibration syndrome. The changer sustains the most hand-related injuries (42%) on the pit crew team, while carriers commonly sustain injuries to their digits (29%). Conclusion: Orthopaedic injuries in NASCAR vary between positions. Injuries in NASCAR drivers and pit crew members are a consequence of the distinctive forces associated with each position throughout the course of the racing season. Understanding these forces and position-associated injuries is important for preventive measures and facilitates diagnosis and return-to-play decisions

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

    SciTech Connect

    Galuszka-Muga, Barbara; Muga, Luis M.

    2006-12-31

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

  19. Lower lip pits: van der woude or kabuki syndrome?

    PubMed

    David-Paloyo, Ferri P; Yang, Xuecai; Lin, Ju-Li; Wong, Fen-Hwa; Wu-Chou, Yah-Huei; Lo, Lun-Jou

    2014-11-01

    Kabuki syndrome (KS) is a multiple congenital anomaly/mental retardation syndrome with characteristic facial features. Despite more than 350 documented cases and recent correlation of MLL2 mutations as a genetic cause, its full clinical spectrum is still being defined. This report describes two patients who were initially diagnosed with Van der Woude syndrome (VWS) based on the presence of lower lip pits. However, this finding can occur with KS, albeit infrequently. For patients with lower lip pits, a thorough evaluation should be made to distinguish between VWS and KS, as there are differences in long-term prognosis. PMID:24088119

  20. Description of work for 216-U-Pond test pits

    SciTech Connect

    Kelty, G.G.

    1993-08-11

    This description of work (DOW) details the field activities associated with the test pit excavation and soil sampling at the 216- U-10 Pond (U-10 Pond) in the 200 West Area and will serve as a field guide for those performing the work. It will be used in conjunction with the 200-UP-2 Resource Conservation and Recovery Act of 1976 (RCRA) Facility Investigation/Corrective Measures Study (DOE-RL 1993a, [LFI]) and Site Characterization Manual (WHC 1988a). Test pits will be constructed to characterize the vertical extent of contaminants in sediments within and beneath the former U-10 pond.

  1. Centrifugation applied to drilling fluids and sludge pit cleanup

    SciTech Connect

    Grichar, C.N.

    1987-01-01

    Solid bowl decanting centrifuges are an indispensible part of a well-designed, modern oilfield solids control system. They have application throughout the entire drilling process and during the post-drilling sludge pit cleanup operation. As drilling costs rise further, and as environmental regulations become stricter, the decanting centrifuge will become even more important and contribute more heavily to the overall cost effectiveness of the drilling process. The significance of this technology as applied to drilling fluids and sludge pit cleanup is emphasized in this paper.

  2. Ablation layers to prevent pitting in laser peening

    DOEpatents

    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.

  3. Development of an automated pit packaging system for Pantex

    SciTech Connect

    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.

  4. The effects of pitting on fatigue crack nucleation in 7075-T6 aluminum alloy

    NASA Technical Reports Server (NTRS)

    Ma, LI; Hoeppner, David W.

    1994-01-01

    A high-strength aluminum alloy, 7075-T6, was studied to quantitatively evaluate chemical pitting effects of its corrosion fatigue life. The study focused on pit nucleation, pit growth, and fatigue crack nucleation. Pitting corrosion fatigue experiments were conducted in 3.5 percent NaCl aqueous solution under constant amplitude sinusoidal loading at two frequencies, 5 and 20 Hz. Smooth and unnotched specimens were used in this investigation. A video recording system was developed to allow in situ observation of the surface changes of the specimens during testing. The results indicated that pitting corrosion considerably reduces the fatigue strength by accelerating fatigue crack nucleation. A metallographic examination was conducted on the specimens to evaluate the nature of corrosion pits. First, the actual shapes of the corrosion pits were evaluated by cross-sectioning the pits. Secondly, the relation between corrosion pits and microstructure was also investigated. Finally, the possibility of another corrosion mechanism that might be involved in pitting was explored in this investigation. The fractography of the tested specimens showed that corner corrosion pits were responsible for fatigue crack nucleation in the material due to the associated stress concentration. The pits exhibited variance of morphology. Fatigue life for the experimental conditions appeared to be strongly dependent on pitting kinetics and the crack nucleation stage.

  5. Impact of electroviscosity on the hydraulic conductance of the bordered pit membrane: a theoretical investigation.

    PubMed

    Santiago, Michael; Pagay, Vinay; Stroock, Abraham D

    2013-10-01

    In perfusion experiments, the hydraulic conductance of stem segments ( ) responds to changes in the properties of the perfusate, such as the ionic strength ( ), pH, and cationic identity. We review the experimental and theoretical work on this phenomenon. We then proceed to explore the hypothesis that electrokinetic effects in the bordered pit membrane (BPM) contribute to this response. In particular, we develop a model based on electroviscosity in which hydraulic conductance of an electrically charged porous membrane varies with the properties of the electrolyte. We use standard electrokinetic theory, coupled with measurements of electrokinetic properties of plant materials from the literature, to determine how the conductance of BPMs, and therefore , may change due to electroviscosity. We predict a nonmonotonic variation of with with a maximum reduction of 18%. We explore how this reduction depends on the characteristics of the sap and features of the BPM, such as pore size, density of chargeable sites, and their dissociation constant. Our predictions are consistent with changes in observed for physiological values of sap and pH. We conclude that electroviscosity is likely responsible, at least partially, for the electrolyte dependence of conductance through pits and that electroviscosity may be strong enough to play an important role in other transport processes in xylem. We conclude by proposing experiments to differentiate the impact of electroviscosity on from that of other proposed mechanisms.

  6. 30 CFR 56.3131 - Pit or quarry wall perimeter.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Pit or quarry wall perimeter. 56.3131 Section 56.3131 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Ground...

  7. 30 CFR 56.3131 - Pit or quarry wall perimeter.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Pit or quarry wall perimeter. 56.3131 Section 56.3131 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Ground...

  8. 30 CFR 56.3131 - Pit or quarry wall perimeter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Pit or quarry wall perimeter. 56.3131 Section 56.3131 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Ground...

  9. 30 CFR 56.3131 - Pit or quarry wall perimeter.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Pit or quarry wall perimeter. 56.3131 Section 56.3131 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Ground...

  10. THE IMPACT OF PHOSPHATE ON COPPER PITTING CORROSION

    EPA Science Inventory

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

  11. Pitting behavior of aluminum ion implanted with nitrogen

    SciTech Connect

    McCafferty, E.; Natishan, P.M.; Hubler, G.K.

    1997-07-01

    Ion implantation of {approx} 2 at% N into aluminum increased the pitting potential in 0.1 M sodium chloride by an average of 0.35 V. Surface analysis by x-ray photoelectron spectroscopy showed implanted nitrogen was present as several species: NH{sub 4}{sup +}, NO or NH{sub 3} (as a ligand), AIN, and weakly bound or interstitial nitrogen. With anodic polarization, there was an increase in the total amount of nitrogen in the near-surface region, a decrease in the relative amount of nitride, and an increase in the relative amount of NO or NH{sub 3}. These changes resulted from migration of implanted nitrogen from the substrate into the near-surface region with partial conversion of the AIN species to NO or NH{sub 3}. It was suggested that the effect of implanted nitrogen on pitting behavior of aluminum is similar to that in nitrogen-containing stainless steels, where nitrogen at the metal surface inhibits the dissolution kinetics or aids the repassivation process in the pit by forming NH{sub 4}{sup +} ions that buffer the pit electrolyte.

  12. 80. ARAIII. Forming of the mechanical equipment pit in reactor ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    80. ARA-III. Forming of the mechanical equipment pit in reactor building (ARA-608). Camera facing northwest. September 22, 1958. Ineel photo no. 58-4675. Photographer: Jack L. Anderson. - Idaho National Engineering Laboratory, Army Reactors Experimental Area, Scoville, Butte County, ID

  13. Operational apron with pit hydrants in foreground, aircraft in background. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Operational apron with pit hydrants in foreground, aircraft in background. View to west - Offutt Air Force Base, Looking Glass Airborne Command Post, Operational & Hangar Access Aprons, Spanning length of northeast half of Project Looking Glass Historic District, Bellevue, Sarpy County, NE

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

    ERIC Educational Resources Information Center

    McColman, Don

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

  15. 8. COLLAPSED AND SCATTERED BUILDING ON FLOOR OF PIT, WITH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. COLLAPSED AND SCATTERED BUILDING ON FLOOR OF PIT, WITH PILE OF RHYOLITE BOULDERS IN BACKGROUND, VIEW TO SOUTH - Iron Springs Quarry, 150 feet west of Grand Loop Road, 20 miles east of U.S. Highway 287, West Thumb, Teton County, WY

  16. Pitting corrosion of low-Cr austenitic stainless steels

    SciTech Connect

    Bullard, Sophie J.; Covino, Bernard S. Jr.

    1996-01-01

    The Albany Research Center has investigated the pitting corrosion resistance of experimental low-Cr stainless steels and several commercial stainless steels in chloride-containing aqueous and atmospheric environments. Previous research had shown the experimental alloys to be as corrosion resistant as commercial stainless steels in chloride-free acid environments. The alloys studied were Fe-8Cr-16Ni-5.5Si-1Cu-(0-1)Mo, 304 SS, and 316 SS. These alloys were examined by immersion and electrochemical tests in 3.5 wt. pct. NaCl and 6 wt.pct.FeCl{sub 3}. Results of these tests showed that the addition of one weight percent Mo improved the pitting resistance of the low-Cr alloy and that the Mo-containing experimental alloy was as resistant to pitting as the commercial alloys. Electrochemical tests did, however, show the experimental alloys to be slightly less resistant to pitting than the commercial alloys. Because of these results, the low-Cr alloy with one weight percent Mo and 304 SS were exposed for one year to a marine atmospheric environment on the coast of Oregon. The marine atmospheric corrosion resistance of the low-Cr alloy was found to be comparable to that for type 304 stainless steel.

  17. CONSTRUCTION PROGRESS PHOTO SHOWING EXCAVATION PIT FOR MAIN PROCESSING BUILDING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    CONSTRUCTION PROGRESS PHOTO SHOWING EXCAVATION PIT FOR MAIN PROCESSING BUILDING (CPP-601) LOOKING NORTHWEST. INL PHOTO NUMBER NRTS-50-885. Unknown Photographer, 10/30/1950 - Idaho National Engineering Laboratory, Idaho Chemical Processing Plant, Fuel Reprocessing Complex, Scoville, Butte County, ID

  18. 62. Historic propellant piping diagram of oxidant pit at Building ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    62. Historic propellant piping diagram of oxidant pit at Building 202, January 6, 1956. NASA GRC drawing no. CF-101644. (On file at NASA Glenn Research Center). - Rocket Engine Testing Facility, GRC Building No. 202, NASA Glenn Research Center, Cleveland, Cuyahoga County, OH

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

    EPA Science Inventory

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

  20. 39. VIEW EAST INSIDE WEST COUNTERWEIGHT PIT GEAR 'D' ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    39. VIEW EAST INSIDE WEST COUNTERWEIGHT PIT - GEAR 'D' IS AT CENTER OF PHOTOGRAPH - BOTTOM OF COUNTERWEIGHT IS AT TOP RIGHT OF PHOTOGRAPH - Tomlinson Bridge, Spanning Quinnipiac River at Forbes Street (U.S. Route 1), New Haven, New Haven County, CT

  1. EXTERIOR VIEW, LOOKING NORTH, OF THE 'OLD PIT' WITH EXTRACTION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    EXTERIOR VIEW, LOOKING NORTH, OF THE 'OLD PIT' WITH EXTRACTION OF LIMESTONE IN PROCESS. AN ELEVEN-HOLE SHOT IS DISLODGING APPROXIMATELY 25,000 TONS OF LIMESTONE FOR USE IN ROAD CONSTRUCTION. - Vulcan Material Company, Calera Quarry, 1614 Highway 84, Calera, Shelby County, AL

  2. 6. View of turbine pit at unit 3 showing servomotor ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. View of turbine pit at unit 3 showing servo-motor head (left of center) with piston rods bolted to turbine gate operation ring (right foreground). View to southeast. - Holter Hydroelectric Facility, Dam & Power House, End of Holter Dam Road, Wolf Creek, Lewis and Clark County, MT

  3. 4. VIEW OF TURBINE PIT AT UNIT 3 SHOWING SERVOMOTOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. VIEW OF TURBINE PIT AT UNIT 3 SHOWING SERVO-MOTOR HEADS (BACKGROUND AT CENTER) WITH PISTON RODS BOLTED TO TURBINE GATE OPERATION RING (CENTER AT LEFT AND CENTER AT RIGHT). VIEW TO THE NORTH-NORTHWEST. - Black Eagle Hydroelectric Facility, Powerhouse, Great Falls, Cascade County, MT

  4. 7. View of turbine pit at an exciter unit showing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. View of turbine pit at an exciter unit showing servo-motor heads (foreground and background at left) with piston rods bolted to the operating ring of the turbine gate (foreground and background at center). View to northeast. - Holter Hydroelectric Facility, Dam & Power House, End of Holter Dam Road, Wolf Creek, Lewis and Clark County, MT

  5. 12. Detail of engine pit in machine shop section of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. Detail of engine pit in machine shop section of roundhouse. Engine house section of roundhouse visible in background through rectangular openings. View to southeast. - Duluth & Iron Range Rail Road Company Shops, Roundhouse, Southwest of downtown Two Harbors, northwest of Agate Bay, Two Harbors, Lake County, MN

  6. 17. INTERIOR VIEW, BASEMENT, LOOKING SOUTHWEST AT THE GEAR PIT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. INTERIOR VIEW, BASEMENT, LOOKING SOUTHWEST AT THE GEAR PIT BELOW THE GRINDING STONES, SHOWING WOODEN COGS ATTACHED TO UNDERGROUND TURBINES. FRICTION DRIVE VISIBLE BEHIND CONTROL BAR (LEFT) WHICH OPERATES SMUT MILL - Schech's Mill, Beaver Creek State Park, La Crescent, Houston County, MN

  7. 106. Photocopied August 1978. EXTENSION OF TAIL PIT WALLS, APRIL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    106. Photocopied August 1978. EXTENSION OF TAIL PIT WALLS, APRIL 28, 1917. THE TIMBERWORK IN THE FOREGROUND WAS USED AS A COMBINATION COFFER DAM AND FORM FOR POURING THE CONCRETE TAIL RACE WALL EXTENSION. IN THE BACKGROUND ALONG THE POWER HOUSE SEVERAL COMPLETED WALL EXTENSIONS CAN BE SEEN DIMLY. (787) - Michigan Lake Superior Power Company, Portage Street, Sault Ste. Marie, Chippewa County, MI

  8. 5. Credit GE. Photographic copy of photograph, completed flame pit ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. Credit GE. Photographic copy of photograph, completed flame pit in Test Stand 'A' with steel plate flame deflector over refractory brick. (JPL negative no. 383-1033, 17 January 1946) - Jet Propulsion Laboratory Edwards Facility, Test Stand A, Edwards Air Force Base, Boron, Kern County, CA

  9. Dental Pit and Fissure Sealants: Implications for School Health Personnel.

    ERIC Educational Resources Information Center

    McCormack-Brown, K. R.; And Others

    1989-01-01

    To promote good personal hygiene practices in students, school health personnel must be informed about dental pit and fissure sealants and related programs. Adoption and maintenance of such programs may depend on the success of school health personnel in educating administrators and policymakers. (SM)

  10. 3. VIEW OF THE DEPRESSION PIT IN ROOM 103, IN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. VIEW OF THE DEPRESSION PIT IN ROOM 103, IN 1965, WHEREIN FISSILE SOLUTION WAS STORED. THIS PHOTOGRAPH SHOWS THE URANIUM SOLUTION TANKS ON THE LEFT AND THE PLUTONIUM SYSTEM ON THE RIGHT. NO PLUTONIUM SOLUTION WAS EVER STORED IN BUILDING 886. - Rocky Flats Plant, Critical Mass Laboratory, Intersection of Central Avenue & 86 Drive, Golden, Jefferson County, CO

  11. 60. FORWARD AIRPLANE ELEVATOR PIT WITH ELEVATOR IN RAISED POSITION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    60. FORWARD AIRPLANE ELEVATOR PIT WITH ELEVATOR IN RAISED POSITION AFT LOOKING FORWARD ON CENTERLINE SHOWING ELEVATOR GUIDES, WIREWAYS, SHEAVES, HYDRAULIC OIL TANKS AND ELEVATOR LANDING PADS. - U.S.S. HORNET, Puget Sound Naval Shipyard, Sinclair Inlet, Bremerton, Kitsap County, WA

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

    SciTech Connect

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

    1999-01-01

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

  13. Statistical analysis of pitting corrosion in condenser tubes

    SciTech Connect

    Ault, J.P.; Gehring, G.A. Jr.

    1997-12-31

    Condenser tube failure via wall penetration allows cooling water to contaminate the working fluid (steam). Contamination, especially from brackish or saltwater, will lower steam quality and thus lower overall plant efficiency. Because of the importance of minimizing leakages, power plant engineers are primarily concerned with the maximum localized corrosion in a unit rather than average corrosion values or rates. Extreme value analysis is a useful tool for evaluating the condition of condenser tubing. Extreme value statistical techniques allow the prediction of the most probable deepest pit in a given surface area based upon data acquired from a smaller surface area. Data is gathered from a physical examination of actual tubes (either in-service or from a sidestream unit) rather than small sample coupons. Three distinct applications of extreme value statistics to condenser tube evaluation are presented in this paper: (1) condition assessment of an operating condenser, (2) design data for material selection, and (3) research tool for assessing impact of various factors on condenser tube corrosion. The projections for operating units based on extreme value analysis are shown to be more useful than those made on the basis of other techniques such as eddy current or electrochemical measurements. Extreme value analysis would benefit from advances in two key areas: (1) development of an accurate and economical method for the measurement of maximum pit depths of condenser tubes in-situ would enhance the application of extreme value statistical analysis to the assessment of condenser tubing corrosion pitting and (2) development of methodologies to predict pit depth-time relationship in addition to pit depth-area relationship would be useful for modeling purposes.

  14. Analysis of Proximity-1 Space Link Interleaved Time Synchronization (PITS) Protocol

    NASA Technical Reports Server (NTRS)

    Woo, Simon S.

    2011-01-01

    To synchronize clocks between spacecraft in proximity, the Proximity-1 Space Link Interleaved Time Synchronization (PITS) Protocol has been proposed. PITS is based on the NTP Interleaved On-Wire Protocol and is capable of being adapted and integrated into CCSDS Proximity-1 Space Link Protocol with minimal modifications. In this work, we will discuss the correctness and liveness of PITS. Further, we analyze and evaluate the performance of time synchronization latency with various channel error rates in different PITS operational modes.

  15. SPERTI Reactor Pit Building (PER605) sections and details. Section DD ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    SPERT-I Reactor Pit Building (PER-605) sections and details. Section D-D shows relationship between pit and roof elevation of the building. Profile of earth fill between Pit Building and Instrument Cell Building. Details of valve and sump pits. Idaho Operations Office PER-605-IDO-2. INEEL index no. 761-0605-60-396-109182 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

  16. Self heating in Si0.5Ge0.5/Si and GaAs/Si thin film device structures

    NASA Astrophysics Data System (ADS)

    Zheng, H.; Jagannadham, K.

    2014-09-01

    Si0.5Ge0.5 and GaAs films grown on Si substrates were used to measure the interface thermal conductance between the films and the substrate. Transient thermoreflectance technique was used with the one-dimensional heat equation to simulate the experimental results. The results showed that the interface thermal conductance of SiGe/Si interface is 100 MW m-2 K-1 and that of GaAs/Si is 20 MW m-2 K-1. These values of interface thermal conductance combined with the thermal conductivity of the films were used to conclude that SiGe films are less susceptible to self heating than GaAs films of same thickness.

  17. Influence of self heating and Li{sub 2}SO{sub 4} addition on the microstructural development of calcium aluminate cement

    SciTech Connect

    Gosselin, Christophe Gallucci, Emmanuel; Scrivener, Karen

    2010-10-15

    Hydrated Calcium Aluminate Cement (CAC) is known to have a complex microstructure involving different phase assemblages strongly dependant on the temperature. This work presents an experimental approach to study the microstructure of CAC pastes from the first minute of hydration with controlled time-temperature histories up to several months of curing. The self heating usually occurring in the CAC concrete is considered and its influence on the growth and assemblage of the hydration products and subsequent space filling is shown. Quantification of the degree of CA hydration by BSE image analysis is used to understand the evolution of phases throughout the hydration process. Lithium sulphate is commonly used to control the setting time of CAC based materials. It is shown that this promotes the formation of more stable hydrates, but slightly reduces the extent of CA hydration.

  18. Adiabatic calorimetry test of the reaction kinetics and self-heating model for 18650 Li-ion cells in various states of charge

    NASA Astrophysics Data System (ADS)

    Chen, Wei-Chun; Wang, Yih-Wen; Shu, Chi-Min

    2016-06-01

    Use of adiabatic calorimetry to characterise thermal runaway of Li-ion cells is a crucial technique in battery safety testing. Various states of charge (SoC) of Li-ion cells were investigated to ascertain their thermal runaway features using a Vent Sizing Package 2 (VSP2) adiabatic calorimeter. To evaluate the thermal runaway characteristics, the temperature-pressure-time trajectories of commercial cylindrical cells were tested, and it was found that cells at a SoC of greater than 50% were subject to thermal explosion at elevated temperatures. Calorimetry data from various 18650 Li-ion cells with different SoC were used to calculate the thermal explosion energies and chemical kinetics; furthermore, a novel self-heating model based on a pseudo-zero-order reaction that follows the Arrhenius equation was found to be applicable for studying the exothermic reaction of a charged cell.

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

    NASA Astrophysics Data System (ADS)

    Grydlik, Martyna; Langer, Gregor; Fromherz, Thomas; Schäffler, Friedrich; Brehm, Moritz

    2013-03-01

    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.

  20. Infrared receptors in the facial pits of the Australian python Morelia spilotes.

    PubMed

    Warren, J W; Proske, U

    1968-01-26

    There is a series of pits in the scales of the rostrum and posterior portion of the lower lips in some pythons and boas. In the Australian python Morelia spilotes, these pits are innervated by the maxillary and mandibular branches of the trigeminal nerve. Structural and neurophysiological evidence indicate that in the pits there are receptors that function as detectors of radiant heat flux.

  1. 7 CFR 52.812 - Score sheet for frozen red tart pitted cherries.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Score sheet for frozen red tart pitted cherries. 52.812 Section 52.812 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING... Pitted Cherries Score Sheet § 52.812 Score sheet for frozen red tart pitted cherries. Size and kind...

  2. 7 CFR 52.802 - Grades of frozen red tart pitted cherries.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Grades of frozen red tart pitted cherries. 52.802... OTHER PROCESSED FOOD PRODUCTS 1 United States Standards for Grades of Frozen Red Tart Pitted Cherries Product Description and Grades § 52.802 Grades of frozen red tart pitted cherries. (a) “U.S. Grade A”...

  3. 7 CFR 52.812 - Score sheet for frozen red tart pitted cherries.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Score sheet for frozen red tart pitted cherries. 52... for Grades of Frozen Red Tart Pitted Cherries Score Sheet § 52.812 Score sheet for frozen red tart pitted cherries. Size and kind of container Container mark or identification Label (style of pack,...

  4. 7 CFR 52.812 - Score sheet for frozen red tart pitted cherries.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Score sheet for frozen red tart pitted cherries. 52... for Grades of Frozen Red Tart Pitted Cherries Score Sheet § 52.812 Score sheet for frozen red tart pitted cherries. Size and kind of container Container mark or identification Label (style of pack,...

  5. 7 CFR 52.812 - Score sheet for frozen red tart pitted cherries.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Score sheet for frozen red tart pitted cherries. 52.812 Section 52.812 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING... Pitted Cherries Score Sheet § 52.812 Score sheet for frozen red tart pitted cherries. Size and kind...

  6. 7 CFR 52.784 - Score sheet for canned red tart pitted cherries.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Score sheet for canned red tart pitted cherries. 52.784 Section 52.784 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING... Pitted Cherries 1 Score Sheet § 52.784 Score sheet for canned red tart pitted cherries. Size and kind...

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

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Grades of frozen red tart pitted cherries. 52.802... OTHER PROCESSED FOOD PRODUCTS 1 United States Standards for Grades of Frozen Red Tart Pitted Cherries Product Description and Grades § 52.802 Grades of frozen red tart pitted cherries. (a) “U.S. Grade A”...

  8. 7 CFR 52.784 - Score sheet for canned red tart pitted cherries.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Score sheet for canned red tart pitted cherries. 52.784 Section 52.784 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING... Pitted Cherries 1 Score Sheet § 52.784 Score sheet for canned red tart pitted cherries. Size and kind...

  9. 7 CFR 52.812 - Score sheet for frozen red tart pitted cherries.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Score sheet for frozen red tart pitted cherries. 52..., AND CERTAIN OTHER PROCESSED FOOD PRODUCTS 1 United States Standards for Grades of Frozen Red Tart Pitted Cherries Score Sheet § 52.812 Score sheet for frozen red tart pitted cherries. Size and kind...

  10. 7 CFR 52.784 - Score sheet for canned red tart pitted cherries.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Score sheet for canned red tart pitted cherries. 52..., AND CERTAIN OTHER PROCESSED FOOD PRODUCTS 1 United States Standards for Grades of Canned Red Tart Pitted Cherries 1 Score Sheet § 52.784 Score sheet for canned red tart pitted cherries. Size and kind...

  11. 7 CFR 52.802 - Grades of frozen red tart pitted cherries.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Grades of frozen red tart pitted cherries. 52.802... OTHER PROCESSED FOOD PRODUCTS 1 United States Standards for Grades of Frozen Red Tart Pitted Cherries Product Description and Grades § 52.802 Grades of frozen red tart pitted cherries. (a) “U.S. Grade A”...

  12. 78 FR 33894 - Proposed Information Collection (Open Burn Pit Registry Airborne Hazard Self-Assessment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-05

    ... AFFAIRS Proposed Information Collection (Open Burn Pit Registry Airborne Hazard Self-Assessment... members of the Armed Forces to toxic airborne chemicals and fumes caused by open burn pits. DATES: Written...: cynthia.harvey-pryor@va.gov . Please refer to ``OMB Control No. 2900-NEW, Open Burn Pit Registry...

  13. 78 FR 54956 - Agency Information Collection (Open Burn Pit Registry Airborne Hazard Self-Assessment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-06

    ... AFFAIRS Agency Information Collection (Open Burn Pit Registry Airborne Hazard Self-Assessment....rennie@va.gov . Please refer to ``OMB Control No. 2900-NEW, Open Burn Pit Registry Airborne Hazard Self-Assessment Questionnaire.'' SUPPLEMENTARY INFORMATION: Title: Open Burn Pit Registry Airborne Hazard...

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

    USGS Publications Warehouse

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

    2003-01-01

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

  15. The pitting behavior of structural electrodeposits used in MEMS applications.

    SciTech Connect

    Wall, Frederick Douglas; Serna, Lysle M.; Martinez, Michael A.

    2004-10-01

    LIGA is an acronym for the German terms Lithographie, Galvanoformung, Abformung, which describe a microfabrication process for high aspect ratio, structural parts based on electrodeposition of a metal into a poly-methyl-methacrylate (PMMA) mold. LIGA produced parts have very high dimensional tolerances (on the order of a micron) and can vary in size from microns to centimeters. These properties make LIGA parts ideal for incorporation into MEMS devices or for other applications where strict tolerances must be met; however, functionality of the parts can only be maintained if they remain dimensionally stable throughout their lifetime. It follows that any form of corrosion attack (e.g., uniform dissolution, localized pitting, environmental cracking, etc.) cannot be tolerated. This presentation focuses on the pitting behavior of Ni electrodeposits, specifically addressing the influence of the following: grain structure, alloy composition, impurities, plating conditions, post plating processing (including chemical and thermal treatment), galvanic interactions and environment (aqueous vs. atmospheric). A small subset of these results is summarized. A typical LIGA part is shown in Figure 1. Due to the small size scale, electrochemical testing was performed using a capillary based test system. Although very small test areas can be probed with this system (e.g., Figure 2), typically capillaries on the order of 80 to 90 ?m's were used in the testing. All LIGA parts tested in the as-received condition had better pitting resistance than the high purity wrought Ni material used as a control. In the case of LIGA-Ni and LIGA-Ni-Mn, no detrimental effects were observed due to aging at 700C. Ni-S (approximately 500 ppm S), showed good as-received pitting behavior but decreased pitting resistance with thermal aging. Aged Ni-S showed dramatic increases in grain size (from single {micro}m's to 100's of {micro}m's), and significant segregation of S to the boundaries. The capillary test

  16. Design review report: AN valve pit upgrades for Project W-314, tank farm restoration and safe operations

    SciTech Connect

    Boes, K.A.

    1998-01-13

    This Design Review Report (DRR) documents the contractor design verification methodology and records associated with project W-314`s AN Valve Pit Upgrades design package. The DRR includes the documented comments and their respective dispositions for this design. Acceptance of the comment dispositions and closure of the review comments is indicated by the signatures of the participating reviewers. Project W-314, Tank Farm Restoration and Safe Operations, is a project within the Tank Waste Remediation System (TWRS) Tank Waste Retrieval Program. This project provides capital upgrades for the existing Hanford tank farms` waste transfer, instrumentation, ventilation, and electrical infrastructure systems. To support established TWRS programmatic objectives, the project is organized into two distinct phases. The initial focus of the project (i.e., Phase 1) is on waste transfer system upgrades needed to support the TWRS Privatization waste feed delivery system. Phase 2 of the project will provide upgrades to support resolution of regulatory compliance issues, improve tank infrastructure reliability, and reduce overall plant operating/maintenance costs. Within Phase 1 of the W-314 project, the waste transfer system upgrades are further broken down into six major packages which align with the project`s work breakdown structure. Each of these six sub-elements includes the design, procurement, and construction activities necessary to accomplish the specific tank farm upgrades contained within the package. The first package to be performed is the AN Valve Pit Upgrades package. The scope of the modifications includes new pit cover blocks, valve manifolds, leak detectors, transfer line connections (for future planned transfer lines), and special protective coating for the 241-AN-A and 241-AN-B valve pits.

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

    NASA Astrophysics Data System (ADS)

    Schirmer, M.; Jamieson, B.

    2014-03-01

    Driven by temperature gradients, kinetic snow metamorphism plays an import role in avalanche formation. When gradients based on temperatures measured 10 cm apart appear to be insufficient for kinetic metamorphism, faceting close to a crust can be observed. Recent studies that visualised 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 these 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 artificial surface structures such as shovel scours. Cutting through a crust with a cutting blade or 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 was only observed at times during a strong cooling/warming of the exposed pit wall. 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 more slowly compared with convex areas (bumps) when applying temperature differences between snow and air. This can be explained by increased radiative and/or turbulent energy transfer at convex areas. Thermal videos suggest that such processes influence the snow temperature within seconds. Our findings show the limitations of using a thermal camera for measuring pit-wall temperatures, particularly during windy conditions, clear skies and large temperature differences between air and snow. At crusts or other

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

    PubMed

    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

  19. A laser gyro with a four-mirror square resonator: formulas for simulating the dynamics of the synchronisation zone parameters of the frequencies of counterpropagating waves during the device operation in the self-heating regime

    SciTech Connect

    Bondarenko, E A

    2014-04-28

    For a laser gyro with a four-mirror square resonator we have developed a mathematical model, which allows one to simulate the temporal behaviour of the synchronisation zone parameters of the frequencies of counterpropagating waves in a situation when the device operates in the self-heating regime and is switched-on at different initial temperatures. (laser gyroscopes)

  20. Building pit dewatering: application of transient analytic elements.

    PubMed

    Zaadnoordijk, Willem J

    2006-01-01

    Analytic elements are well suited for the design of building pit dewatering. Wells and drains can be modeled accurately by analytic elements, both nearby to determine the pumping level and at some distance to verify the targeted drawdown at the building site and to estimate the consequences in the vicinity. The ability to shift locations of wells or drains easily makes the design process very flexible. The temporary pumping has transient effects, for which transient analytic elements may be used. This is illustrated using the free, open-source, object-oriented analytic element simulator Tim(SL) for the design of a building pit dewatering near a canal. Steady calculations are complemented with transient calculations. Finally, the bandwidths of the results are estimated using linear variance analysis.

  1. Surface aspects of pitting and stress corrosion cracking

    NASA Technical Reports Server (NTRS)

    Truhan, J. S., Jr.; Hehemann, R. F.

    1977-01-01

    The pitting and stress corrosion cracking of a stable austenitic stainless steel in aqueous chloride environments were investigated using a secondary ion mass spectrometer as the primary experimental technique. The surface concentration of hydrogen, oxygen, the hydroxide, and chloride ion, magnesium or sodium, chromium and nickel were measured as a function of potential in both aqueous sodium chloride and magnesium chloride environments at room temperature and boiling temperatures. It was found that, under anodic conditions, a sharp increase in the chloride concentration was observed to occur for all environmental conditions. The increase may be associated with the formation of an iron chloride complex. Higher localized chloride concentrations at pits and cracks were also detected with an electron microprobe.

  2. Open pit slope deformation monitoring by fiber Bragg grating sensors

    NASA Astrophysics Data System (ADS)

    Xu, Guoquan; Xiong, Daiyu; Duan, Yun; Cao, Xiaoshuang

    2015-01-01

    With microstrain resolution and the capability to sample at rates of 2000 Hz or higher, fiber Bragg grating (FBG) strain sensor offers exciting new possibilities for in situ deformation monitoring induced by blasting load in an open pit slope. Here, we are developing a new technology for measuring deformation in real time on the microstrain in an open pit slope during the blasting. A fiber optically instrumented rock mass strain sensor measured strain at 100-cm intervals along a two anchor rock bolt grouted in the slope intact rock mass. In field testing, a number of transient signals have been observed, which in some cases were large enough to trigger rapid sampling. The combination of short- and long-term observation offers new insight into the slope stability and blasting cumulative effects. Therefore, FBG sensors are a useful tool for measuring in situ strain in intact rock masses.

  3. Integrating Safeguards into the Pit Disassembly and Conversion Facility

    SciTech Connect

    Clark, T.G.

    2002-05-28

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

  4. Geologic report for the Weldon Spring Raffinate Pits Site

    SciTech Connect

    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.

  5. The Effects of Hot Corrosion Pits on the Fatigue Resistance of a Disk Superalloy

    NASA Technical Reports Server (NTRS)

    Gabb, Timothy P.; Telesman, Jack; Hazel, Brian; Mourer, David P.

    2009-01-01

    The effects of hot corrosion pits on low cycle fatigue life and failure modes of the disk superalloy ME3 were investigated. Low cycle fatigue specimens were subjected to hot corrosion exposures producing pits, then tested at low and high temperatures. Fatigue lives and failure initiation points were compared to those of specimens without corrosion pits. Several tests were interrupted to estimate the fraction of fatigue life that fatigue cracks initiated at pits. Corrosion pits significantly reduced fatigue life by 60 to 98 percent. Fatigue cracks initiated at a very small fraction of life for high temperature tests, but initiated at higher fractions in tests at low temperature. Critical pit sizes required to promote fatigue cracking were estimated, based on measurements of pits initiating cracks on fracture surfaces.

  6. 12. "TEST STAND; STRUCTURAL; DEFLECTOR PIT DETAILS, SHEET NO. 1." ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. "TEST STAND; STRUCTURAL; DEFLECTOR PIT DETAILS, SHEET NO. 1." Specifications No. ENG-04-353-55-72; Drawing No. 60-09-12; sheet 41 of 148; file no. 1320/92, Rev. A. Stamped: RECORD DRAWING - AS CONSTRUCTED. Below stamp: Contract no. 4338, no change. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Test Stand 1-A Terminal Room, Test Area 1-120, north end of Jupiter Boulevard, Boron, Kern County, CA

  7. 30. VIEW DOWN INTO TURBINE PIT SHOWING WICKET GATE CONTROL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    30. VIEW DOWN INTO TURBINE PIT SHOWING WICKET GATE CONTROL MECHANISM AND MAIN SHAFT OF I. P. MORRIS TURBINE. TURBINE BUILT BY I. P. MORRIS & DE LA VERGNE, INC. OF PHILADELPHIA, PA, AND INSTALLED IN 1925. TURBINE RATED AT 18,000 HP AT 113.3 RPM UNDER 18.5 FEET OF HEAD. - Lake Lynn Hydroelectric Power House & Dam, Cheat River, Morgantown, Monongalia County, WV

  8. 11. Turbine Pit and Shaft of Unit 1, view to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Turbine Pit and Shaft of Unit 1, view to the south, with operating ring at base of shaft and servo motor arms in foreground and in left background recess. Turbine monitoring and auxiliary equipment is located in the rightbackground recess. - Washington Water Power Clark Fork River Noxon Rapids Hydroelectric Development, Powerhouse, South bank of Clark Fork River at Noxon Rapids, Noxon, Sanders County, MT

  9. 20. Interior view of fuel storage pit or vault adjacent ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. Interior view of fuel storage pit or vault adjacent to Test Cell 9 in Component Test Laboratory (T-27), looking west. Photograph shows upgraded instrumentation, piping, tanks, and technological modifications installed in 1997-99 to accommodate component testing requirements for the Atlas V missile. - Air Force Plant PJKS, Systems Integration Laboratory, Components Test Laboratory, Waterton Canyon Road & Colorado Highway 121, Lakewood, Jefferson County, CO

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

    SciTech Connect

    Palmer, E.R.

    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.

  11. 3. Unit 4 Turbine Pit Shaft and Operating Ring, view ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. Unit 4 Turbine Pit Shaft and Operating Ring, view to the northeast. One of the servo motor housings is visible in the right background of the photograph. Notice the wicket gate linkage greasing tubes along the top of the operating ring. - Washington Water Power Clark Fork River Cabinet Gorge Hydroelectric Development, Powerhouse, North Bank of Clark Fork River at Cabinet Gorge, Cabinet, Bonner County, ID

  12. The Origin of Subretinal Fluid in Optic Disc Pit Maculopathy.

    PubMed

    Türkçüoğlu, Peykan; Taskapan, Cagtay

    2016-03-01

    A surgical approach for the drainage of fluid leaking over the pit in optic disc pit maculopathy is described, and a theory of the origin of fluid is discussed. In two cases, complete fluid-air exchange was performed. The air infusion pressure was decreased to 5 mm Hg, and the collected fluid was drained by raising the infusion pressure to 25 mm Hg. The fluid inside the back-flush needle was routed via a microcentrifuge tube. Biochemical analyses of the fluids were conducted in order to find their origin. Results of the first and second case were comparable to normal cerebrospinal fluid (CSF) levels (chloride: 125 mmol/L, 122 mmol/L; sodium: 146 mmol/L, 147 mmol/L; potassium: 2.8 mmol/L, 3.0 mmol/L; protein: 29 mg/dL, 18.4 mg/ dL; and glucose: 60 mg/dL, 57 mg/dL, respectively). These findings suggest that the origin of subretinal fluid found in the submacular space in optic disc pit maculopathy is CSF.

  13. Origin of small pits in martian impact craters

    NASA Astrophysics Data System (ADS)

    Boyce, Joseph M.; Wilson, Lionel; Mouginis-Mark, Peter J.; Hamilton, Christopher W.; Tornabene, Livio L.

    2012-09-01

    We propose a numerical model for the formation of the closely-spaced pits found in the thin, ejecta-related deposits superposed on the floors, interior terrace blocks, and near-rim ejecta blankets of well-preserved martian impact craters. Our model predicts the explosive degassing of water from this pitted material, which is assumed to originally be water-bearing, impact melt-rich breccia at the time of deposition. This process is analogous to what occurred in the fall-out suevite deposits at the Ries impact structure in Germany. At Ries, impact heating of water-bearing target material resulted in the rapid degassing of its water and other volatiles. The martian environment plays an important role in enhancing the effects of this degassing by increasing the flow-speed of the escaping gas. The high flow-rate of gas through particulate materials, such as suevite, tends to quickly form segregation channels or vent pipes, similar to those found in the Ries deposits. These pipes act as conduits for the efficient high-speed escape of the gas and small clasts that it entrains. Escaping gas and entrained clasts abraded and eroded the conduit walls, flaring them to form pits above a network of pipes.

  14. Clean option: Berkeley Pit water treatment and resource recovery strategy

    SciTech Connect

    Gerber, M.A.; Orth, R.J.; Elmore, M.R.; Monzyk, B.F.

    1995-09-01

    The US Department of Energy (DOE), Office of Technology Development, established the Resource Recovery Project (RRP) in 1992 as a five-year effort to evaluate and demonstrate multiple technologies for recovering water, metals, and other industrial resources from contaminated surface and groundwater. Natural water resources located throughout the DOE complex and the and western states have been rendered unusable because of contamination from heavy metals. The Berkeley Pit, a large, inactive, open pit copper mine located in Butte, Montana, along with its associated groundwater system, has been selected by the RRP for use as a feedstock for a test bed facility located there. The test bed facility provides the infrastructure needed to evaluate promising technologies at the pilot plant scale. Data obtained from testing these technologies was used to assess their applicability for similar mine drainage water applications throughout the western states and at DOE. The objective of the Clean Option project is to develop strategies that provides a comprehensive and integrated approach to resource recovery using the Berkeley Pit water as a feedstock. The strategies not only consider the immediate problem of resource recovery from the contaminated water, but also manage the subsequent treatment of all resulting process streams. The strategies also employ the philosophy of waste minimization to optimize reduction of the waste volume requiring disposal, and the recovery and reuse of processing materials.

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

    SciTech Connect

    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.

  16. PitPro 1.1 User's Manual; Pit-tag to SURPH Data Translation Utility, Technical Manual 2003.

    SciTech Connect

    Westhagen, Peter; Skalski, John

    2003-07-01

    This manual describes the use of Program PitPro to convert PIT-tag data files in PTAGIS (PIT Tag Information System, Pacific States Marine Fisheries Commission) to input files ready for survival analysis in Program SURPH 2.1. This utility converts the various PIT-tag detections at the multitude of detector coils within a juvenile bypass or at adult counting windows and ladders into capture histories. The capture histories indicate whether a tagged fish was detected, not detected, or detected and censored at the major hydroprojects in the Columbia Basin. A major update to this program is the inclusion of adult upstream detection histories. Adult detection histories include not only whether the fish was detected or not but also the year of detection for proper adult survival estimation. The SURPH program is a valuable tool for estimating survival and detection probabilities of fish migrating in the Snake and Columbia rivers. Using special input data files, SURPH computes reach-to-reach statistics for any release group passing a system of detection sites. However, PIT-tag data, as available from PTAGIS, comes in a form that is not ready for use as SURPH input. SURPH requires a capture history for each fish. A capture history consists of a series of fields, one for each detection site, that has a code for whether the fish was detected and returned to the river, detected and removed, or not detected. The data, as received from PTAGIS, has one line for each detection with information such as fish identification (id), detection date and time, number of coil hits and detector coil ids, etc. Because an individual fish may be detected at several coils within a detection site as well as at several detection sites, each fish is often represented by multiple lines in the PTAGIS data file. For the PTAGIS data to be usable by SURPH, it must be preprocessed. The data must be condensed down to one line per fish with the relevant detection information from the PTAGIS file

  17. Impacts of swine manure pits on groundwater quality

    USGS Publications Warehouse

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

    2002-01-01

    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 ??15N and ??18O 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 streptococcus bacteria were detected at least once in groundwater from all monitoring wells at both sites

  18. Canister Storage Building Receiving Pit Modification Informal Design Verification

    SciTech Connect

    KRIEG, S.A.

    2000-10-09

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

  19. Impacts of swine manure pits on groundwater quality.

    PubMed

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

    2002-01-01

    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 delta15N and delta15O 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 streptococcus bacteria were detected at least once in groundwater from all monitoring wells at both

  20. Complex Burial and Exhumation of South Polar Cap Pitted Terrain

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This image is illuminated by sunlight from the upper left. The two prominent bright stripes at the left/center of the image are covered with bright frost and thus create the illusion that they are sunlit from the lower left.

    The large pits, troughs, and 'swiss cheese' of the south polar residual cap appear to have been formed in the upper 4 or 5 layers of the polar material. Each layer is approximately 2 meters (6.6 feet) thick. Some Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) images of this terrain show examples in which older pitted and eroded layers have been previously buried and are now being exhumed. The example shown here includes two narrow, diagonal slopes that trend from upper left toward lower right at the left/center portion of the frame. Along the bottoms of these slopes are revealed a layer that underlies them in which there are many more pits and troughs than in the upper layer. It is likely in this case that the lower layer formed its pits and troughs before it was covered by the upper layer. This observation suggests that the troughs, pits, and 'swiss cheese' features of the south polar cap are very old and form over long time scales.

    The picture is located near 84.6oS, 45.1oW, and covers an area 3 km by 5 km (1.9 x 3.1 mi) at a resolution of about 3.8 meters (12 ft) per pixel. The image was taken during southern spring on August 29, 1999.

    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.

  1. Explanation of Significant Difference (ESD) for the A-Area Burning/Rubble Pits (731-A/1A) and Rubble Pit (731-2A) (U)

    SciTech Connect

    Morgan, Randall

    2000-11-17

    The A-Area Burning/Rubble Pits (731-A/1A) and Rubble Pit (731-2A) (ABRP) operable unit (OU) is located in the northwest portion of Savannah River Site (SRS), approximately 2.4 kilometers (1.5 miles) south of the A/M Area operations. Between 1951 and 1973, Pits 731-A and 731-1A were used to burn paper, plastics, wood, rubber, rags, cardboard, oil, degreasers, and solvents. Combustible materials were burned monthly. After burning was discontinued in 1973, Pits 731-A and 731-1A were also converted to rubble pits and used to dispose of concrete rubble, bricks, tile, asphalt, plastics, metal, wood products, and rubber until about 1978. When the pits were filled to capacity, there were covered with compacted clay-rich native soils and vegetation was established. Pit 731-2A was only used as a rubble pit until 1983 after which the area was backfilled and seeded. Two other potential source areas within the OU were investigated and found to be clean. The water table aquifer (M-Area aquifer) was also investigated.

  2. Pit membrane structure is highly variable and accounts for a major resistance to water flow through tracheid pits in stems and roots of two boreal conifer species.

    PubMed

    Schulte, Paul J; Hacke, Uwe G; Schoonmaker, Amanda L

    2015-10-01

    The flow of xylem sap in conifers is strongly dependent on the presence of a low resistance path through bordered pits, particularly through the pores present in the margo of the pit membrane. A computational fluid dynamics approach was taken, solving the Navier-Stokes equation for models based on the geometry of pits observed in tracheids from stems and roots of Picea mariana (black spruce) and Picea glauca (white spruce). Model solutions demonstrate a close, inverse relationship between the total resistance of bordered pits and the total area of margo pores. Flow through the margo was dominated by a small number of the widest pores. Particularly for pits where the margo component of flow resistance was low relative to that of the torus, pore location near the inner edge of the margo allowed for greater flow than that occurring through similar-sized pores near the outer edge of the margo. Results indicate a surprisingly large variation in pit structure and flow characteristics. Nonetheless, pits in roots have lower resistance to flow than those in stems because the pits were wider and consisted of a margo with a larger area in pores. PMID:25944400

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

    SciTech Connect

    Tan Hua; Jiang Yiming; Deng Bo; Sun Tao; Xu Juliang; Li Jin

    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.

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

    SciTech Connect

    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.

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

    PubMed

    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.

  6. Effects of hydrogen on film structure and pitting susceptibility of nickel and 310 stainless steel

    SciTech Connect

    Zeng, Y.M.; Chu, W.Y.; Qiao, L.J.; Yang, Q.; Luo, J.L.

    1998-12-31

    Effects of hydrogen on the pitting susceptibility of Ni and 310 stainless steel (SS) were investigated. The results showed that hydrogen changed p-type oxide of 310 SS to n-type while it did not change the p-type oxide of Ni. Hydrogen enhanced remarkably pitting susceptibility of 310 SS. No pitting occurred for over 6 days for the samples without precharged hydrogen in 6% FeCl{sub 3} solution at room temperature. For samples precharged with very small current density of 0.1 mA/cm{sup 2}, pitting occurred within 80 minutes. The pitting even occurred within 2 minutes for the charged samples with current density of 0.5 mA/cm{sup 2}. Hydrogen decreased pitting incubation time, increased pitting initiation density and growth rate. Average pit diameter D increased linearly with logarithm of immersion time t, i.e., D = {alpha} ln(t) + {beta}, where {alpha} and {beta} are constants. The value of constant {alpha} increased with the rise of charging current density. Effect of hydrogen on the pitting of Ni was not so obvious as on 310 SS. The hydrogen interactions with defects both in surface film and metal were used to explain the hydrogen deleterious effects on the resistance to pitting corrosion.

  7. Application of gradient-based Hough transform to the detection of corrosion pits in optical images

    NASA Astrophysics Data System (ADS)

    Wang, Yafei; Cheng, Guangxu

    2016-03-01

    In this paper, we introduce a circle detection technique named Hough transform to automatically recognize the corrosion pits in microscopic images. All the points in the input image are transformed into a parameter space, which is represented by a two-dimensional accumulative array with the same size of the original image. Local extreme values in the accumulative array, which represent the candidates of corrosion pits, are located using a maxima searching algorithm. The accuracy of detecting the number, radius and coordinate of pits from simulated images was examined. The results show that more than 95% of pits were successfully detected and the average errors of radius and coordinate are less than 10%, while these errors have negligible effect on the pit size distribution. The introduced method can also differentiate pits from scratches or inclusions, as indicated by the 100% accuracy of pit detection, from the simulated images presented in this study. Therefore, it is believed that the gradient-based Hough transform is a powerful method for the recognition of corrosion pits in microscopic images, making the statistical analysis of pit size and pit locations easier and more efficient.

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

    PubMed

    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.

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

    PubMed

    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

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

    PubMed

    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.

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

    PubMed Central

    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

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

    SciTech Connect

    NNSA /NV

    2001-09-20

    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.

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

    USGS Publications Warehouse

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

    1993-01-01

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

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

    PubMed

    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

  15. A self-heated silicon nanowire array: selective surface modification with catalytic nanoparticles by nanoscale Joule heating and its gas sensing applications.

    PubMed

    Yun, Jeonghoon; Jin, Chun Yan; Ahn, Jae-Hyuk; Jeon, Seokwoo; Park, Inkyu

    2013-08-01

    We demonstrated novel methods for selective surface modification of silicon nanowire (SiNW) devices with catalytic metal nanoparticles by nanoscale Joule heating and local chemical reaction. The Joule heating of a SiNW generated a localized heat along the SiNW and produced endothermic reactions such as hydrothermal synthesis of nanoparticles or thermal decomposition of polymer thin films. In the first method, palladium (Pd) nanoparticles could be selectively synthesized and directly coated on a SiNW by the reduction of the Pd precursor via Joule heating of the SiNW. In the second method, a sequential process composed of thermal decomposition of a polymer, evaporation of a Pd thin film, and a lift-off process was utilized. The selective decoration of Pd nanoparticles on SiNW was successfully accomplished by using both methods. Finally, we demonstrated the applications of SiNWs decorated with Pd nanoparticles as hydrogen detectors. We also investigated the effect of self-heating of the SiNW sensor on its sensing performance. PMID:23770994

  16. Evidence for an explosive origin of central pit craters on Mars

    NASA Astrophysics Data System (ADS)

    Williams, Nathan R.; Bell, James F.; Christensen, Philip R.; Farmer, Jack D.

    2015-05-01

    Kilometer-scale pits are nested in the centers of many impact craters on Mars as well as on icy satellites. They have been inferred to form in the presence of a water-ice rich substrate; however, the process(es) responsible for their formation is still debated. Previous models invoke origins by either explosive excavation of potentially water-bearing crustal material, or by subsurface drainage of meltwater and/or collapse. If explosive excavation forms central pits, pit-derived ejecta should be draped around the pits, whereas internal collapse should not deposit significant material outside pit rims. Using visible wavelength images from the Mars Reconnaissance Orbiter (MRO) Context Camera (CTX) and High Resolution Imaging Science Experiment (HiRISE) instruments and thermal infrared images from the Odyssey Thermal Emission Imaging System (THEMIS) instrument, we conducted a survey to characterize, in detail, the global population of central pits in impact craters ⩾10 km in diameter. We specifically examined the morphology and thermophysical characteristics of the pits for evidence of pit ejecta. Our analysis of thermal images suggests that coarse-grained materials are distributed proximally around many central pits on the floors of their host craters. The decrease in average grain size with distance from pit rims is consistent with pit-derived ejecta. These observations and interpretations better support an explosive origin for central pits on Mars than they do an origin of subsurface meltwater drainage and collapse of the overlying substrate. A major weakness to previous explosive central pit formation models is the inability for them to form pits late enough in the impact process to be preserved. To address this, we present an alternative "melt contact model" where a central uplift brings ice-bearing substrate into contact with impact melt to generate steam explosions and excavate central pits during the impact modification stage. Theoretical calculations show

  17. Drainage pits in cohesionless materials - Implications for the surface of PHOBOS

    NASA Astrophysics Data System (ADS)

    Horstman, K. C.; Melosh, H. J.

    1989-09-01

    The origin of the pits and grooves on the surface of Phobos visible on the Viking orbital images of Phobos is investigated using a model of the mechanism of venting and drainage of regolith into open fractures, which is the mechanism that is best supported by image data. In this model, drainage pits and fissures are modeled experimentally by considering two rigid substrate plates placed edge to edge and covered by uniform thicknesses of dry fragmental debris (simulated regolith); fracture extension is simulated by drawing the plates apart, allowing the regolith to drain into the newly created void. The resulting experimental patterns of pits and grooves were found to have pronounced similarities with those observed on Phobos, displaying many characteristics, such as the lack of raised rims, the linearity of grooves and chains of pits, a uniform spacing of pits, and the progression from discrete pits to cuspate grooves, which are the same as those observed on Phobos.

  18. Pit Formation during the Self-Assembly of Dithiol Monolayers on Au(111)

    NASA Astrophysics Data System (ADS)

    Macdairmid, A. R.; Cappello, M. L.; Keeler, W. J.; Banks, J. T.; Gallagher, M. C.

    2000-03-01

    The formation of pits one gold atom deep during the growth of alkanethiol monolayers on Au(111), has been observed previously by others. Explanations for pit formation include etching of the substrate, or mass transport of gold atom + thiol molecule on the surface, due to changes in surface energy^1. We have investigated the structure of dithiothreitol (DTT) SAMs on Au(111). Ex situ STM measurements indicate similar pitting occurs during formation of the dithiol monolayer. The degree of pitting depends on exposure time, sample temperature during formation, and subsequent annealing of the sample. Pitting is enhanced considerasbly when DTT is coordinated with Ti, in fact DTT/Ti films exhibit considerable pit motion during STM imaging. ^1 F. Teran et al. Electrochimica Acta 44, 1053 (1998).

  19. A method to predict evolving post-closure pit lake chemistry

    SciTech Connect

    Davis, A.; Fennemore, G.G.

    1998-12-31

    There are currently over 50 active open pit mines in Nevada, at least 30 of which may be inundated by ground water upon pit closure, forming lakes as deep as 200 m when the pumps dewatering the excavation are turned off. With the growing awareness of environmental issues related to mining, prediction of future pit-lake chemistry has become mandatory during permitting, to determine both potential ecological risk, and long-term impacts on downgradient groundwater quality. This paper outline a methodology that couples a groundwater model (MODFLOW) with the rate of solute leaching from pit wall rocks (derived from field experiments and the FND pyrite oxidation model), and the geochemical reactions occurring in the pit lake water column (using PHREEQC). The model would predict pit lake water quality (chemogenesis) from the juvenile infilling condition through a mature, hydrogeologically steady-state condition.

  20. 12. Turbine Pit Servo Motors of Unit 1, view to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. Turbine Pit Servo Motors of Unit 1, view to the southeast. The servo motors are set into wall recesses and operated by the governors. Note the wicket gate linkages visible in the lower center of the photograph, between the deck plates and the operating ring. Also note the wicket gate linkage grease lines along the wall just below the lights. - Washington Water Power Clark Fork River Noxon Rapids Hydroelectric Development, Powerhouse, South bank of Clark Fork River at Noxon Rapids, Noxon, Sanders County, MT

  1. Pitting within the Martian South Polar Swiss Cheese Terrain

    NASA Astrophysics Data System (ADS)

    Pathare, A.; Ingersoll, A.; Cushing, G.; Titus, T.

    2004-12-01

    The morphology of the Martian South Permanent Residual Cap is dominated by enigmatic quasi-circular landforms commonly referred to as "Swiss cheese" terrain. These large Swiss cheese depressions, which typically have widths of more than 100 m and extend down to the base of the layer, are expanding at rates of a few meters per Martian year due to CO2 sublimation. We present high-resolution Mars Orbiter Camera (MOC) images detailing extensive "pits," by which we mean small cavities generally less than 10 m in diameter that do not penetrate completely through the Swiss cheese terrain. This pitting is only observed upon the thickest (~10 m) Swiss cheese mesas ("Unit A" as classified by Thomas et al. 2004), and moreover only occurs within 50 meters of the edges of these deposits. We argue that the pits are collapse features caused by the release of CO2 gas from a pressurized layer several meters below the mesa top. As the walls of the mesa retreat due to radiation imbalance, the pressurized layer is exposed, and CO2 vents out laterally, weakening the layer and causing the collapse. We can think of no other process that communicates laterally over distances of 50 meters in one Martian year, which is the time scale over which the pits form. For a layer 6 meters thick, the hydrostatic head is ~200 mbar, which provides an upper bound to the gas pressure in the sealed lower layer. However, for that maximum pressure to be attained, the CO2 in the lower layer must be approximately 30 K warmer than CO2 on the surface. Such a temperature differential is difficult to maintain, though, given that 6 meters is also the thermal skin depth for CO2 over 1 Martian year. We are exploring a number of mechanisms that might continually or cyclically warm this layer and enable rapid venting when the seal is broken. The persistence of polygonal cracks on the mesa tops could be further evidence of subsurface thermal variations.

  2. Method to prevent/mitigate steam explosions in casting pits

    DOEpatents

    Taleyarkhan, R.P.

    1996-12-24

    Steam explosions can be prevented or mitigated during a metal casting process by the placement of a perforated flooring system in the casting pit. An upward flow of compressed gas through this perforated flooring system is introduced during the casting process to produce a buffer layer between any spilled molten metal and the cooling water in the reservoir. This buffer layer provides a hydrodynamic layer which acts to prevent or mitigate steam explosions resulting from hot, molten metal being spilled into or onto the cooling water. 3 figs.

  3. Method to prevent/mitigate steam explosions in casting pits

    DOEpatents

    Taleyarkhan, Rusi P.

    1996-01-01

    Steam explosions can be prevented or mitigated during a metal casting process by the placement of a perforated flooring system in the casting pit. An upward flow of compressed gas through this perforated flooring system is introduced during the casting process to produce a buffer layer between any spilled molten metal and the cooling water in the reservoir. This buffer layer provides a hydrodynamic layer which acts to prevent or mitigate steam explosions resulting from hot, molten metal being spilled into or onto the cooling water.

  4. Pit Profile Simulation for HD DVD Mastering Process

    NASA Astrophysics Data System (ADS)

    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.

  5. An unusual cause of small bowel perforation: apricot pit.

    PubMed

    Atila, Koray; Güler, Sanem; Bora, Seymen; Gülay, Hüseyin

    2011-05-01

    Ingestion of foreign bodies can be a common problem, especially among children, alcoholics, and psychiatric and senile patients. Foreign bodies with smooth edges usually do not pose significant problems, but a sharp foreign object that is not retrieved immediately may penetrate the wall and cause complications. Ingested foreign bodies usually pass the intestinal tract uneventfully, and perforation occurs in less than 1%. In this study, we report a case of small bowel obstruction with perforation in a 73-year-old female due to the accidental swallowing of an apricot pit. PMID:21935813

  6. 4. Unit 4 Turbine Pit Oil Jacking Pump and Wicket ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. Unit 4 Turbine Pit Oil Jacking Pump and Wicket Gate Linkages, view to the north. The jacking pump, located along the wall on the left side of photograph, is used for pumping oil to lift the thrust bearing prior to starting the unit. Note the wicket gate linkages attached to the operating ring and visible in the lower center of the photograph. - Washington Water Power Clark Fork River Cabinet Gorge Hydroelectric Development, Powerhouse, North Bank of Clark Fork River at Cabinet Gorge, Cabinet, Bonner County, ID

  7. Giant weathering pits in the Entrada Sandstone, southeastern Utah: Preliminary findings

    SciTech Connect

    Netoff, D.I. . Dept. of Geography and Geology); Shroba, R.R. )

    1993-04-01

    Giant weathering pits formed in outcrops of the lower Entrada Sandstone slickrock of Jurassic age are present in two areas in the Glen Canyon region of arid southeastern Utah. The pits are far larger than any previously described in the geologic literature. The pits near Cookie Jar Butte are commonly cylindrical, typically have low width-to-depth ratios (1.5--3.6), and have a depth of closure of as much as 18 m. There are no obvious lithologic or structural controls that determine their shape or location. Many of the pits at Rock Creek Bay are elongate; several of them have long axes in excess of 53 m, and the longest one is 74 m. Many of the pit walls are breached at the top, and the depth of closure is generally less than 6 m. The shapes of these pits are influenced by point orientation and pit coalescence. Thin-section analyses of near-surface sandstone cores taken near Cookie Jar Butte from pit walls, floors, and rims reveal no significant diagenetic alteration of the fine-grained to very fine frained quartzose sandstone (quartz arenite). Quartz grains appear fresh, and feldspar grains are only slightly weathered. The cement between the grains is mostly CaCO[sub 3]. In several of the pits in both areas sandy sediment veneers the bedrock floor. This sediment is similar in character to the adjacent sandstone and is probably locally derived. Possible origins of the giant pits include various physical, chemical, and biological weathering processes that initiate pit development, followed by excavation by plunge-pool action, wind deflation, dissolution, and piping. Preliminary field and laboratory data do not clearly identify and single process of group of processes that account for pit development.

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

    SciTech Connect

    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.

  9. Large heterogeneities in comet 67P as revealed by active pits from sinkhole collapse.

    PubMed

    Vincent, Jean-Baptiste; Bodewits, Dennis; Besse, Sébastien; Sierks, Holger; Barbieri, Cesare; Lamy, Philippe; Rodrigo, Rafael; Koschny, Detlef; Rickman, Hans; Keller, Horst Uwe; Agarwal, Jessica; A'Hearn, Michael F; Auger, Anne-Thérèse; Barucci, M Antonella; Bertaux, Jean-Loup; Bertini, Ivano; Capanna, Claire; Cremonese, Gabriele; Da Deppo, Vania; Davidsson, Björn; Debei, Stefano; De Cecco, Mariolino; El-Maarry, Mohamed Ramy; Ferri, Francesca; Fornasier, Sonia; Fulle, Marco; Gaskell, Robert; Giacomini, Lorenza; Groussin, Olivier; Guilbert-Lepoutre, Aurélie; Gutierrez-Marques, P; Gutiérrez, Pedro J; Güttler, Carsten; Hoekzema, Nick; Höfner, Sebastian; Hviid, Stubbe F; Ip, Wing-Huen; Jorda, Laurent; Knollenberg, Jörg; Kovacs, Gabor; Kramm, Rainer; Kührt, Ekkehard; Küppers, Michael; La Forgia, Fiorangela; Lara, Luisa M; Lazzarin, Monica; Lee, Vicky; Leyrat, Cédric; Lin, Zhong-Yi; Lopez Moreno, Josè J; Lowry, Stephen; Magrin, Sara; Maquet, Lucie; Marchi, Simone; Marzari, Francesco; Massironi, Matteo; Michalik, Harald; Moissl, Richard; Mottola, Stefano; Naletto, Giampiero; Oklay, Nilda; Pajola, Maurizio; Preusker, Frank; Scholten, Frank; Thomas, Nicolas; Toth, Imre; Tubiana, Cecilia

    2015-07-01

    Pits have been observed on many cometary nuclei mapped by spacecraft. It has been argued that cometary pits are a signature of endogenic activity, rather than impact craters such as those on planetary and asteroid surfaces. Impact experiments and models cannot reproduce the shapes of most of the observed cometary pits, and the predicted collision rates imply that few of the pits are related to impacts. Alternative mechanisms like explosive activity have been suggested, but the driving process remains unknown. Here we report that pits on comet 67P/Churyumov-Gerasimenko are active, and probably created by a sinkhole process, possibly accompanied by outbursts. We argue that after formation, pits expand slowly in diameter, owing to sublimation-driven retreat of the walls. Therefore, pits characterize how eroded the surface is: a fresh cometary surface will have a ragged structure with many pits, while an evolved surface will look smoother. The size and spatial distribution of pits imply that large heterogeneities exist in the physical, structural or compositional properties of the first few hundred metres below the current nucleus surface.

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

    SciTech Connect

    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).

  11. Printability and inspectability of programmed pit defects on teh masks in EUV lithography

    SciTech Connect

    Kang, I.-Y.; Seo, H.-S.; Ahn, B.-S.; Lee, D.-G.; Kim, D.; Huh, S.; Koh, C.-W.; Cha, B.; Kim, S.-S.; Cho, H.-K.; Mochi, I.; Goldberg, K. A.

    2010-03-12

    Printability and inspectability of phase defects in ELlVL mask originated from substrate pit were investigated. For this purpose, PDMs with programmed pits on substrate were fabricated using different ML sources from several suppliers. Simulations with 32-nm HP L/S show that substrate pits with below {approx}20 nm in depth would not be printed on the wafer if they could be smoothed by ML process down to {approx}1 nm in depth on ML surface. Through the investigation of inspectability for programmed pits, minimum pit sizes detected by KLA6xx, AIT, and M7360 depend on ML smoothing performance. Furthermore, printability results for pit defects also correlate with smoothed pit sizes. AIT results for pattemed mask with 32-nm HP L/S represents that minimum printable size of pits could be {approx}28.3 nm of SEVD. In addition, printability of pits became more printable as defocus moves to (-) directions. Consequently, printability of phase defects strongly depends on their locations with respect to those of absorber patterns. This indicates that defect compensation by pattern shift could be a key technique to realize zero printable phase defects in EUVL masks.

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

    SciTech Connect

    SASAKI,K.; ISAACS,H.S.; LEVY,P.W.

    2001-09-02

    Aluminum, in a chloride containing solutions close to its pitting potential, shows vigorous fluctuations in current and potential. Measurements have been made of the freely corroding potential, and the currents between interconnected electrodes. It is shown that there is a transition in the behavior of the transients. The transition occurs when multiple active pits are present and electrochemical communication occurs between them. The major source of current and potential transients is the growth process in the active pits rather than meta-stable pitting at the passive surface.

  13. Effects of wall linings on moisture ingress into traditional grain storage pits.

    PubMed

    el-Tayeb Abdalla, A; Stigter, C J; Mohamed, H A; Mohammed, A E; Gough, M C

    2001-07-01

    Increasing climate variability, resulting in frequent years of poor rainfall, has recently subjected the traditional subsistence farmers in the Central Clay Plain of the Sudan to longer periods of food shortage. However, excess production in years of good rainfall could bridge the gap of years with poor rainfall if the grain is properly stored. Resource-poor farmers have tried several linings to improve the traditional underground pit ("matmura") they use for storage of sorghum. In the experimental study described here, pits with two types of lining: (i) a mixture of mud, cow dung and straw and (ii) sorghum chaff, were compared with unlined pits. Six closed pits were used, two for each type, and temperature and moisture content were monitored. It was found that the temperature increased in all pits and at all positions within the pits, with few differences between the linings. Moisture levels also increased everywhere but the sources of moisture were at the sides and bottoms of the pits. The chaff-lined pits were superior to the others because they showed smaller increases in moisture content at all positions and thus maintained a better quality of sorghum. Joint traditional assessments with local farmers after the pits were opened supported these findings.

  14. Finite Element Modeling of Magnetic Flux Leakage Signals from Mechanical Damage Containing Corrosion Pits

    NASA Astrophysics Data System (ADS)

    Babbar, Vijay; Clapham, Lynann

    2009-03-01

    Steel pipeline defects such as mechanical damage (dents) and corrosion pits have been studied using the magnetic flux leakage (MFL) technique and finite element modeling (FEM). The nature of MFL signals from these defects is generally known. However, since a dented region is more susceptible to corrosion, a dent-pit defect combination may be formed, which adds complexity to signal interpretation. The present work employs FEM to investigate the change in dent signal in the presence of a pit of varying dimensions. It helps to infer if a pit located inside a dent is detectable.

  15. Comparing Central Peak and Central Pit Craters on Mercury and Mars: Implications for Crustal Strength

    NASA Astrophysics Data System (ADS)

    Barlow, Nadine G.; Horstman, Ryan M.

    2016-10-01

    We have measured and classified 20,782 impact craters on Mercury and 24,495 craters on Mars 5 km in diameter and larger for a comparison study of these features. We identified 1144 floor pit and 638 summit pit craters on Mars and 32 summit pit craters but no floor pits on Mercury. We also identified 1682 central peak craters on Mars and 1764 on Mercury. We computed the ratio of the pit or basal peak diameter to the crater diameter in each case and compared the results for the two bodies. Summit pits on Mars have a median pit-to-crater diameter (Dp/Dc) ratio of 0.12 compared to 0.09 on Mercury, indicating pits are slightly larger relative to their parent crater on Mars. We find no correlation of the distribution of Mercury's central pits with features attributed to volatiles, i.e. radar-bright polar craters and craters containing hollows. This indicates that Mercury's central pits form by collapse of a weak brecciated core in the central peak and do not require the presence of volatiles, as is commonly assumed for central pit formation. The median peak-to-crater diameter (Dpk/Dc) ratio for the peaks on which summit pits are found on both bodies is statistically identical to that of the respective normal unpitted central peaks. This indicates that the peaks on which summit pits occur form in the same manner as normal central peaks but subsequently undergo core collapse to create the summit pit. Interestingly, the median Dpk/Dc for Martian peaks is twice as high as for their Mercurian counterparts (0.30 versus 0.15, respectively). Because Mercury and Mars have essentially the same surface gravity, the only major difference between the two bodies that could explain this observation is target characteristics. Prior studies of the composition of the crust and the detection of larger-than-normal secondary craters have led to the proposal that Mercury's crust is stronger than the crusts of the other terrestrial planets. Mercury's low number of central pit craters, the

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

    SciTech Connect

    Knief, R.A.

    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.

  17. Large heterogeneities in comet 67P as revealed by active pits from sinkhole collapse

    NASA Astrophysics Data System (ADS)

    Vincent, Jean-Baptiste; Bodewits, Dennis; Besse, Sébastien; Sierks, Holger; Barbieri, Cesare; Lamy, Philippe; Rodrigo, Rafael; Koschny, Detlef; Rickman, Hans; Keller, Horst Uwe; Agarwal, Jessica; A'Hearn, Michael F.; Auger, Anne-Thérèse; Barucci, M. Antonella; Bertaux, Jean-Loup; Bertini, Ivano; Capanna, Claire; Cremonese, Gabriele; da Deppo, Vania; Davidsson, Björn; Debei, Stefano; de Cecco, Mariolino; El-Maarry, Mohamed Ramy; Ferri, Francesca; Fornasier, Sonia; Fulle, Marco; Gaskell, Robert; Giacomini, Lorenza; Groussin, Olivier; Guilbert-Lepoutre, Aurélie; Gutierrez-Marques, P.; Gutiérrez, Pedro J.; Güttler, Carsten; Hoekzema, Nick; Höfner, Sebastian; Hviid, Stubbe F.; Ip, Wing-Huen; Jorda, Laurent; Knollenberg, Jörg; Kovacs, Gabor; Kramm, Rainer; Kührt, Ekkehard; Küppers, Michael; La Forgia, Fiorangela; Lara, Luisa M.; Lazzarin, Monica; Lee, Vicky; Leyrat, Cédric; Lin, Zhong-Yi; Lopez Moreno, Josè J.; Lowry, Stephen; Magrin, Sara; Maquet, Lucie; Marchi, Simone; Marzari, Francesco; Massironi, Matteo; Michalik, Harald; Moissl, Richard; Mottola, Stefano; Naletto, Giampiero; Oklay, Nilda; Pajola, Maurizio; Preusker, Frank; Scholten, Frank; Thomas, Nicolas; Toth, Imre; Tubiana, Cecilia

    2015-07-01

    Pits have been observed on many cometary nuclei mapped by spacecraft. It has been argued that cometary pits are a signature of endogenic activity, rather than impact craters such as those on planetary and asteroid surfaces. Impact experiments and models cannot reproduce the shapes of most of the observed cometary pits, and the predicted collision rates imply that few of the pits are related to impacts. Alternative mechanisms like explosive activity have been suggested, but the driving process remains unknown. Here we report that pits on comet 67P/Churyumov-Gerasimenko are active, and probably created by a sinkhole process, possibly accompanied by outbursts. We argue that after formation, pits expand slowly in diameter, owing to sublimation-driven retreat of the walls. Therefore, pits characterize how eroded the surface is: a fresh cometary surface will have a ragged structure with many pits, while an evolved surface will look smoother. The size and spatial distribution of pits imply that large heterogeneities exist in the physical, structural or compositional properties of the first few hundred metres below the current nucleus surface.

  18. Large heterogeneities in comet 67P as revealed by active pits from sinkhole collapse.

    PubMed

    Vincent, Jean-Baptiste; Bodewits, Dennis; Besse, Sébastien; Sierks, Holger; Barbieri, Cesare; Lamy, Philippe; Rodrigo, Rafael; Koschny, Detlef; Rickman, Hans; Keller, Horst Uwe; Agarwal, Jessica; A'Hearn, Michael F; Auger, Anne-Thérèse; Barucci, M Antonella; Bertaux, Jean-Loup; Bertini, Ivano; Capanna, Claire; Cremonese, Gabriele; Da Deppo, Vania; Davidsson, Björn; Debei, Stefano; De Cecco, Mariolino; El-Maarry, Mohamed Ramy; Ferri, Francesca; Fornasier, Sonia; Fulle, Marco; Gaskell, Robert; Giacomini, Lorenza; Groussin, Olivier; Guilbert-Lepoutre, Aurélie; Gutierrez-Marques, P; Gutiérrez, Pedro J; Güttler, Carsten; Hoekzema, Nick; Höfner, Sebastian; Hviid, Stubbe F; Ip, Wing-Huen; Jorda, Laurent; Knollenberg, Jörg; Kovacs, Gabor; Kramm, Rainer; Kührt, Ekkehard; Küppers, Michael; La Forgia, Fiorangela; Lara, Luisa M; Lazzarin, Monica; Lee, Vicky; Leyrat, Cédric; Lin, Zhong-Yi; Lopez Moreno, Josè J; Lowry, Stephen; Magrin, Sara; Maquet, Lucie; Marchi, Simone; Marzari, Francesco; Massironi, Matteo; Michalik, Harald; Moissl, Richard; Mottola, Stefano; Naletto, Giampiero; Oklay, Nilda; Pajola, Maurizio; Preusker, Frank; Scholten, Frank; Thomas, Nicolas; Toth, Imre; Tubiana, Cecilia

    2015-07-01

    Pits have been observed on many cometary nuclei mapped by spacecraft. It has been argued that cometary pits are a signature of endogenic activity, rather than impact craters such as those on planetary and asteroid surfaces. Impact experiments and models cannot reproduce the shapes of most of the observed cometary pits, and the predicted collision rates imply that few of the pits are related to impacts. Alternative mechanisms like explosive activity have been suggested, but the driving process remains unknown. Here we report that pits on comet 67P/Churyumov-Gerasimenko are active, and probably created by a sinkhole process, possibly accompanied by outbursts. We argue that after formation, pits expand slowly in diameter, owing to sublimation-driven retreat of the walls. Therefore, pits characterize how eroded the surface is: a fresh cometary surface will have a ragged structure with many pits, while an evolved surface will look smoother. The size and spatial distribution of pits imply that large heterogeneities exist in the physical, structural or compositional properties of the first few hundred metres below the current nucleus surface. PMID:26135448

  19. Comparing Central Pit Craters on Mars, Ganymede, Mercury, and the Moon

    NASA Astrophysics Data System (ADS)

    Barlow, Nadine G.

    2014-11-01

    Central pit craters (CPC) display a central depression either directly on the crater floor (“floor pit”) or atop a central peak (“summit pit”). They are distinct from pitted floor material and peak ring structures and are commonly attributed to removal of target volatiles during crater formation. CPC are common on Mars, Ganymede, and Callisto but also have been reported on Mercury and the Moon, indicating that target volatiles are not the only contributor to their formation. This study compares the morphometric characteristics of CPC on volatile-richer (Ganymede, Mars) and volatile-poorer (Mercury, Moon) bodies to better constrain formation of these features. Our databases of CPC on Mars (1692 craters) and Ganymede (471 craters) are compared with data for Mercury (27 craters) and the Moon (47 craters) by Xiao and colleagues (Xiao and Komatsu, 2013; Xiao et al., 2014). Central pits are divided into floor pit or summit pit based on morphologic appearance and (if available) topographic data, diameters of craters and pits are measured, and geographic distributions are determined. Current results are: (1) Many fewer CPC occur on Mercury and the Moon compared to Ganymede and Mars; (2) No strong correlation of CPC distribution with specific latitude or geologic units is seen for any of the four bodies; (3) CPC occur over the narrowest diameter range (16.0-33.0 km) for Mercury and over the largest diameter range (12.0-143.8 km) for Ganymede; (4) No summit pit craters are identified on Ganymede and no floor pit craters are reported for Mercury; (5) Floor pit craters on Ganymede and Mars can be divided into those with and without an elevated rim around the pit and terrain characteristics influence rimmed vs non-rimmed pit distribution on Mars; (6) Median pit-to-crater diameter (Dp/Dc) values for floor pit craters are largest for volatile-rich Ganymede (0.20) and smallest for volatile-poor Moon (0.12); (7) Median Dp/Dc values for summit pit craters are identical for

  20. A Rare Case of Symptomatic Double Optic Disc Pit without Maculopathy

    PubMed Central

    Abdul-Nabi, Mohammad

    2016-01-01

    Optic disc pits are an uncommon congenital abnormality. Patients remain asymptomatic unless they develop maculopathy. We present a rare case of a double optic disc pit of which only three others have been reported worldwide. A 51-year-old gentleman presented with blurred vision. Fundoscopy revealed a right double optic disc pit. Though he was symptomatic there was no evidence of maculopathy. OCT of macula and disc was otherwise unremarkable. Visual field demonstrated a paracentral defect. Although optic disc pits are rare they are still an important clinical entity. Prompt identification and treatment of complications are required to prevent a poor visual prognosis. PMID:27648324

  1. A Rare Case of Symptomatic Double Optic Disc Pit without Maculopathy.

    PubMed

    Ali, Zaria; Abdul-Nabi, Mohammad

    2016-01-01

    Optic disc pits are an uncommon congenital abnormality. Patients remain asymptomatic unless they develop maculopathy. We present a rare case of a double optic disc pit of which only three others have been reported worldwide. A 51-year-old gentleman presented with blurred vision. Fundoscopy revealed a right double optic disc pit. Though he was symptomatic there was no evidence of maculopathy. OCT of macula and disc was otherwise unremarkable. Visual field demonstrated a paracentral defect. Although optic disc pits are rare they are still an important clinical entity. Prompt identification and treatment of complications are required to prevent a poor visual prognosis. PMID:27648324

  2. Effects of wall linings on moisture ingress into traditional grain storage pits

    NASA Astrophysics Data System (ADS)

    el-Tayeb Abdalla, Ahmed; Stigter, C. J.; A/Hafiz Mohamed, Habiballa; El-Tayeb Mohammed, Ahmed; Gough, M. C.

    Increasing climate variability, resulting in frequent years of poor rainfall, has recently subjected the traditional subsistence farmers in the Central Clay Plain of the Sudan to longer periods of food shortage. However, excess production in years of good rainfall could bridge the gap of years with poor rainfall if the grain is properly stored. Resource-poor farmers have tried several linings to improve the traditional underground pit (''matmura'') they use for storage of sorghum. In the experimental study described here, pits with two types of lining: (i) a mixture of mud, cow dung and straw and (ii) sorghum chaff, were compared with unlined pits. Six closed pits were used, two for each type, and temperature and moisture content were monitored. It was found that the temperature increased in all pits and at all positions within the pits, with few differences between the linings. Moisture levels also increased everywhere but the sources of moisture were at the sides and bottoms of the pits. The chaff-lined pits were superior to the others because they showed smaller increases in moisture content at all positions and thus maintained a better quality of sorghum. Joint traditional assessments with local farmers after the pits were opened supported these findings.

  3. Expression of Pit2 sodium-phosphate cotransporter during murine odontogenesis is developmentally regulated.

    PubMed

    Zhao, Dawei; Vaziri Sani, Forugh; Nilsson, Jeanette; Rodenburg, Michaela; Stocking, Carol; Linde, Anders; Gritli-Linde, Amel

    2006-12-01

    Different sodium-dependent inorganic phosphate (P(i)) uptake mechanisms play a major role in cellular P(i) homeostasis. The function and detailed distribution patterns of the type III Na(+)-phosphate cotransporter, PiT-2, in different organs during development are still largely unknown. We therefore examined the temporospatial expression patterns of Pit2 during murine odontogenesis. Odontoblasts were always devoid of Pit2 expression, whereas a transient, but strong, expression was detected in young secretory ameloblasts. However, the stratum intermedium and, later on, the papillary layer and cells of the subodontoblastic layer, exhibited high levels of Pit2 mRNA, which increased gradually as the tooth matured. Hormonal treatment or P(i) starvation of tooth germs in vitro did not alter Pit2 levels or patterns of expression, indicating mechanisms of regulation different from those of PiT-1 or other cell types. PiT-2 also functions as a retroviral receptor, and functional membrane-localized protein was confirmed throughout the dental papilla/pulp by demonstrating cellular permissiveness to infection by a gammaretrovirus that uses PiT-2 as a receptor. The distinct pattern of Pit2 expression during odontogenesis suggests that its P(i)-transporter function may be important for homeostasis of dental cells and not specifically for mineralization of the dental extracellular matrices. The expression of viral receptors in enamel-forming cells and the dental pulp may be of pathological significance.

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

    SciTech Connect

    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.

  5. Closure of the Brewer Gold Mine by pit backfilling

    SciTech Connect

    Lewis-Russ, A.; Lupo, J.F.; Bronson, J.M.

    1996-12-31

    Brewer Gold Mine, located in north-central South Carolina, is implementing an innovative reclamation plan that includes backfilling the main Brewer open pit with mine waste. The primary goals of the closure are to reduce acid rock drainage and minimize or eliminate long-term operation and maintenance requirements by restoring the site property to approximate pre-mining topography. The plan calls for consolidation of approximately 200 acres of waste into approximately 20 hectares (50 acres). Much of the material to be backfilled into the pit, including spent heap leach material and waste rock, has acid-generating potential. Therefore, the backfill design integrated geochemical properties of the backfill materials with expected post-closure conditions. A prime consideration was the final position of the water table. Since mining at the site started in the early 1800`s, no records exist of the original groundwater levels. Therefore, the design incorporates a large anoxic limestone drain to control the final groundwater level. Additional amendments are to be placed in targeted areas of the backfill to maximize their utilization. A low-permeability cap system that includes a GEOSYNTHETIC clay liner has been designed to limit infiltration into the backfill.

  6. Remaining Sites Verification Package for the 100-F-44:4, Discovery Pipeline in Silica Gel Pit, Waste Site Reclassification Form 2008-030

    SciTech Connect

    J. M. Capron

    2008-09-23

    The 100-F-44:4, Discovery Pipeline in Silica Gel Pit subsite is located in the 100-FR-1 Operable Unit of the Hanford Site, near the location of the former 110-F Gas Storage Tanks structure. The 100-F-44:4 subsite is a steel pipe discovered October 17, 2004, during trenching to locate the 118-F-4 Silica Gel Pit. Based on visual inspection and confirmatory investigation sampling data, the 100-F-44:4 subsite is a piece of non-hazardous electrical conduit debris. The 100-F-44:4 subsite supports unrestricted future use of shallow zone soil and is protective of groundwater and the Columbia River. No residual contamination exists within the deep zone. Therefore, no deep zone institutional controls are required.

  7. Underground Pumped Storage Hydroelectricity using Abandoned Works (open pits and deep mines)

    NASA Astrophysics Data System (ADS)

    Pujades, E.; Willems, T.; Bodeux, S.; Orban, P.; Dassargues, A.

    2015-12-01

    Pumped Storage Hydroelectricity (PSH) is a good alternative to increase the efficiency of power plants, which cannot regulate the amount of electricity generated according to the demand (wind, solar or even nuclear power plants). PSH plants, which consist in two reservoirs located at different heights (upper and lower), can store energy during low demand periods (pumping water from the lower to the upper reservoir) and generate electricity during the high demand peaks (falling water from the upper to the lower reservoir). Given that the two reservoirs must be located at different heights, PSH plants cannot be constructed in flat regions. Nevertheless, in these regions, an alternative could be to use abandoned underground works (open pits or deep mines) as lower reservoirs to construct Underground Pumped Storage Hydroelectricity (UPSH) plants. To select the best place to construct a plant, two considerations must be taken into account regarding the interaction between UPSH plants and groundwater: 1) the alteration of the natural conditions of aquifers and 2), the efficiency of the plant since the electricity generated depends on the hydraulic head inside the underground reservoir. Obviously, a detailed numerical model must be necessary before to select a location. However, a screening methodology to reject the most disadvantageous sites in a short period of time would be useful. Groundwater flow impacts caused by UPSH plants are analyzed numerically and the main variables involved in the groundwater evolution are identified. The most noticeable effect consists in an oscillation of the groundwater. The hydraulic head around which groundwater oscillates, the magnitude of the oscillations and the time to achieve a "dynamic steady state" depend on the boundaries, the parameters of the aquifer and the characteristics of the underground reservoir. A screening methodology is proposed to assess the main impacts caused in aquifers by UPSH plants. Finally, the efficiency

  8. Effect of Feeding Date Pits on Milk Production, Composition and Blood Parameters of Lactating Ardi Goats.

    PubMed

    Al-Suwaiegh, S B

    2016-04-01

    Twenty Ardi lactating goats were used to investigate the effect of substituting 10%, 15%, and 20% of concentrate feed with date pits on milk production, composition, and blood parameters. Four isocaloric and isonitrogenous dietary treatments were used. Four levels (0% [control], 10%, 15%, and 20%) of date pits were used to replace concentrate feed. The forages to concentrate ratio used was 60 to 40. Dry matter intake (DMI) of goats fed diets containing 10% and 15% date pits was significantly (p<0.05) higher than those fed diets containing 0% and 20%. However, goats fed a diet containing 20% date pits were significantly (p<0.05) lower in DMI compared to those fed control diet. The protein percent was significantly higher for goats fed control diet compared to the other dietary treatments. Total solids percent was significantly the lowest for goats fed diet supplemented with 10% date pits. Goats fed a diet containing 20% date pits was significantly (p<0.05) higher in the total protein compared to those fed a diet containing 10%. In addition, goats fed a diet containing 15% date pits exhibited no significant differences in the total protein percent compared to those fed a diet containing 20% date pits. Triglyceride was significantly higher for goats fed diets containing 10% and 20% date pits compared to those fed 15% date pits. Results obtained in the present study suggest that date pits can be added up to 20% of the concentrate feeds into lactating Ardi goat diets without negative effects on their productive performance. PMID:26949951

  9. Effect of Feeding Date Pits on Milk Production, Composition and Blood Parameters of Lactating Ardi Goats.

    PubMed

    Al-Suwaiegh, S B

    2016-04-01

    Twenty Ardi lactating goats were used to investigate the effect of substituting 10%, 15%, and 20% of concentrate feed with date pits on milk production, composition, and blood parameters. Four isocaloric and isonitrogenous dietary treatments were used. Four levels (0% [control], 10%, 15%, and 20%) of date pits were used to replace concentrate feed. The forages to concentrate ratio used was 60 to 40. Dry matter intake (DMI) of goats fed diets containing 10% and 15% date pits was significantly (p<0.05) higher than those fed diets containing 0% and 20%. However, goats fed a diet containing 20% date pits were significantly (p<0.05) lower in DMI compared to those fed control diet. The protein percent was significantly higher for goats fed control diet compared to the other dietary treatments. Total solids percent was significantly the lowest for goats fed diet supplemented with 10% date pits. Goats fed a diet containing 20% date pits was significantly (p<0.05) higher in the total protein compared to those fed a diet containing 10%. In addition, goats fed a diet containing 15% date pits exhibited no significant differences in the total protein percent compared to those fed a diet containing 20% date pits. Triglyceride was significantly higher for goats fed diets containing 10% and 20% date pits compared to those fed 15% date pits. Results obtained in the present study suggest that date pits can be added up to 20% of the concentrate feeds into lactating Ardi goat diets without negative effects on their productive performance.

  10. Pitting corrosion of inconel 600 in high-temperature water containing CuCl/sub 2/

    SciTech Connect

    Park, J.R.; Szklarska-Smialowska, Z.

    1985-11-01

    Pitting corrosion of Inconel 600 was studied in aqueous sodium and cupric chloride solutions at 60 and 280 C. The pit nucleation potential, E /SUB np/ was evaluated in two different concentrations of sodium chloride. E /SUB np/ decreased with increasing concentrations of the chloride ion and with temperature. On specimen surfaces exposed to cupric chloride solutions, pitting occurred at open circuit potentials nearly equal to or higher than the E /SUB np/ determined by anodic polarization in 0.01 M NaCl solution. The number and size of the pits increased with increasing concentrations of cupric chloride and dissolved oxygen. On specimens partly covered with polytetrafluorethylene (PTFE) tape (i.e., in the presence of artificial crevices), pitting occurre more easily at low concentrations of CuCl/sub 2/ (less than or equal to20 ppm CuCl/sub 2/ in deaerated solutions at 280 C). Tubes covered with oxide films that formed during the operation of model boilers exhibited greater pitting resistance than tubes with clean surfaces at 280 C, but less resistance at 60 C. Corrosion products contained in the pits were enriched in chromium with small amounts of copper, sulfur, and chlorine. The composition of corrosion products covering the pits was similar to that in the pits, but with the additional enrichment of iron. Presumably, sulfur present in Inconel 600 as an impurity was significant in the pitting process. The probable mechanism of the processes leading to pitting of Inconel 600 tubing in high-temperature water is discussed.

  11. Effect of Feeding Date Pits on Milk Production, Composition and Blood Parameters of Lactating Ardi Goats

    PubMed Central

    AL-Suwaiegh, S. B.

    2016-01-01

    Twenty Ardi lactating goats were used to investigate the effect of substituting 10%, 15%, and 20% of concentrate feed with date pits on milk production, composition, and blood parameters. Four isocaloric and isonitrogenous dietary treatments were used. Four levels (0% [control], 10%, 15%, and 20%) of date pits were used to replace concentrate feed. The forages to concentrate ratio used was 60 to 40. Dry matter intake (DMI) of goats fed diets containing 10% and 15% date pits was significantly (p<0.05) higher than those fed diets containing 0% and 20%. However, goats fed a diet containing 20% date pits were significantly (p<0.05) lower in DMI compared to those fed control diet. The protein percent was significantly higher for goats fed control diet compared to the other dietary treatments. Total solids percent was significantly the lowest for goats fed diet supplemented with 10% date pits. Goats fed a diet containing 20% date pits was significantly (p<0.05) higher in the total protein compared to those fed a diet containing 10%. In addition, goats fed a diet containing 15% date pits exhibited no significant differences in the total protein percent compared to those fed a diet containing 20% date pits. Triglyceride was significantly higher for goats fed diets containing 10% and 20% date pits compared to those fed 15% date pits. Results obtained in the present study suggest that date pits can be added up to 20% of the concentrate feeds into lactating Ardi goat diets without negative effects on their productive performance. PMID:26949951

  12. Inconsistent identification of pit bull-type dogs by shelter staff.

    PubMed

    Olson, K R; Levy, J K; Norby, B; Crandall, M M; Broadhurst, J E; Jacks, S; Barton, R C; Zimmerman, M S

    2015-11-01

    Shelter staff and veterinarians routinely make subjective dog breed identification based on appearance, but their accuracy regarding pit bull-type breeds is unknown. The purpose of this study was to measure agreement among shelter staff in assigning pit bull-type breed designations to shelter dogs and to compare breed assignments with DNA breed signatures. In this prospective cross-sectional study, four staff members at each of four different shelters recorded their suspected breed(s) for 30 dogs; there was a total of 16 breed assessors and 120 dogs. The terms American pit bull terrier, American Staffordshire terrier, Staffordshire bull terrier, pit bull, and their mixes were included in the study definition of 'pit bull-type breeds.' Using visual identification only, the median inter-observer agreements and kappa values in pair-wise comparisons of each of the staff breed assignments for pit bull-type breed vs. not pit bull-type breed ranged from 76% to 83% and from 0.44 to 0.52 (moderate agreement), respectively. Whole blood was submitted to a commercial DNA testing laboratory for breed identification. Whereas DNA breed signatures identified only 25 dogs (21%) as pit bull-type, shelter staff collectively identified 62 (52%) dogs as pit bull-type. Agreement between visual and DNA-based breed assignments varied among individuals, with sensitivity for pit bull-type identification ranging from 33% to 75% and specificity ranging from 52% to 100%. The median kappa value for inter-observer agreement with DNA results at each shelter ranged from 0.1 to 0.48 (poor to moderate). Lack of consistency among shelter staff indicated that visual identification of pit bull-type dogs was unreliable. PMID:26403955

  13. High Rate Laser Pitting Technique for Solar Cell Texturing

    SciTech Connect

    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

  14. The effect of normal pulsed Nd-YAG laser irradiation on pits and fissures in human teeth.

    PubMed

    Bahar, A; Tagomori, S

    1994-01-01

    The effects of normal pulsed Nd-YAG laser irradiation on the acid resistance of human dental enamel of pits and fissures, the cleaning of the pit and fissure contents and fluoride uptake into deep pits and fissures were examined. The acid resistance of the pit and fissure enamel was evaluated by the amount of dissolved calcium per square millimeter of the surface area. The pit and fissure enamel treated with laser irradiation obtained an acid resistance 30% higher than that of the unlased controls. The cleaning effect of laser irradiation on the pit and fissure contents was compared with chemicomechanical and mechanical methods. The laser irradiation was found to clean the pits and fissures to a greater depth without alterating the shape of pits and fissures, compared with the other two methods. The distribution of calcium, phosphorus and fluoride in the enamel of the pits and fissures was then measured by electron probe microanalyzer. At the entrance and in the deep part of the pits and fissures, the fluoride content of the enamel treated with acidulated phosphate fluoride after laser irradiation was higher than that of the enamel treated with acidulated phosphate fluoride alone. These results thus suggest that Nd-YAG laser irradiation might be effective in increasing the acid resistance of the pit and fissure enamel, while removing the pit and fissure debris contents and increasing the fluoride uptake into the pit and fissure enamel.

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

    SciTech Connect

    POWERS, T.B.

    1999-12-09

    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.

  16. 86. ARAIII. GCRE reactor building (ARA608) showing mechanical loop pit ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    86. ARA-III. GCRE reactor building (ARA-608) showing mechanical loop pit after building shell had been erected. Beyond pit are demineralized water surge tank and heat exchanger. Camera facing northeast. December 22, 1958. Ineel photo no. 58-6427. Photographer: Ken Mansfield. - Idaho National Engineering Laboratory, Army Reactors Experimental Area, Scoville, Butte County, ID

  17. 90. ARAIII. GCRE reactor building (ARA608) mechanical loop pit. Shows ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    90. ARA-III. GCRE reactor building (ARA-608) mechanical loop pit. Shows nitrogen gas compressor in foreground, piping installations on walls of pit, and other details. February 24, 1959. Ineel photo no. 59-880. Photographer: Ken Mansfield. - Idaho National Engineering Laboratory, Army Reactors Experimental Area, Scoville, Butte County, ID

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

  20. PREVENTION OF ACID MINE DRAINAGE GENERATION FROM OPEN-PIT MINE HIGHWALLS

    EPA Science Inventory



    Exposed, open pit mine highwalls contribute significantly to the production of acid mine

    drainage (AMD) thus causing environmental concerns upon closure of an operating mine. Available information on the generation of AMD from open-pit mine highwalls is very limit...

  1. Different presentations of intraretinal fluid collections in optic disc pits: OCT study of 3 cases.

    PubMed

    Brasil, Oswaldo Ferreira Moura; Brasil, Maria Vitoria Oliveira Moura; Brasil, Oswaldo Moura

    2006-01-01

    The congenital optic disc pit is a rare anomaly that can lead to major visual impairment associated with subretinal fluid accumulation. The authors describe the optical coherence tomography study of three cases of untreated congenital optic disc pits with different levels of visual impairment and its different presentations of intraretinal fluid collections.

  2. 21 CFR 872.3765 - Pit and fissure sealant and conditioner.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Pit and fissure sealant and conditioner. 872.3765 Section 872.3765 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3765 Pit and fissure sealant...

  3. 21 CFR 872.3765 - Pit and fissure sealant and conditioner.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Pit and fissure sealant and conditioner. 872.3765 Section 872.3765 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3765 Pit and fissure sealant...

  4. 41. 44INCH SOAKING PITS. A MORGAN CRANE LOWERS THE STEEL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    41. 44-INCH SOAKING PITS. A MORGAN CRANE LOWERS THE STEEL INGOT INTO A 'SOAKING PIT,' WHERE IT IS HEATED TO A UNIFORM TEMPERATURE PRIOR TO ROLLING. THE INGOT RECEIVES ITS FIRST ROLLING ON THE 44-INCH BLOOMING MILL. - Corrigan, McKinney Steel Company, 3100 East Forty-fifth Street, Cleveland, Cuyahoga County, OH

  5. A Comprehensive Investigation of Copper Pitting Corrosion in a Drinking Water Distribution System

    EPA Science Inventory

    Copper pipe pitting is a complicated corrosion process for which exact causes and solutions are uncertain. This paper presents the findings of a comprehensive investigation of a cold water copper pitting corrosion problem in a drinking water distribution system, including a refi...

  6. 7 CFR 52.784 - Score sheet for canned red tart pitted cherries.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Score sheet for canned red tart pitted cherries. 52... VEGETABLES, PROCESSED PRODUCTS THEREOF, AND CERTAIN OTHER PROCESSED FOOD PRODUCTS 1 United States Standards for Grades of Canned Red Tart Pitted Cherries 1 Score Sheet § 52.784 Score sheet for canned red...

  7. BRINE STORAGE PIT AND PUMP HOUSE, TRA631. ELEVATIONS. CONCRETE VAULT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    BRINE STORAGE PIT AND PUMP HOUSE, TRA-631. ELEVATIONS. CONCRETE VAULT FOR BRINE PITS. CONCRETE BLOCK BUILDING FOR BRINE PUMPS. CONCRETE PIPE TRENCH. BLAW-KNOX 3150-808-3, 1/1951. INL INDEX NO. 531-0608-00-098-100677. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  8. 68. Interior view in pit "B" showing air compressor/purifier on ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    68. Interior view in pit "B" showing air compressor/purifier on left, and entry door to pit in center, with fallout shelter/escapr route on right, looking east - Nike Missile Battery MS-40, County Road No. 260, Farmington, Dakota County, MN

  9. 7 CFR 52.3754 - Size designations for whole and pitted styles.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... of Canned Ripe Olives 1 Product Description, Types, Styles, and Grades § 52.3754 Size designations for whole and pitted styles. (a) General. (1) “Average count” for canned whole ripe olives is... olives. (2) Diameters of canned whole and pitted ripe olives are determined by measuring the...

  10. 7 CFR 52.3754 - Size designations for whole and pitted styles.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... of Canned Ripe Olives 1 Product Description, Types, Styles, and Grades § 52.3754 Size designations for whole and pitted styles. (a) General. (1) “Average count” for canned whole ripe olives is... olives. (2) Diameters of canned whole and pitted ripe olives are determined by measuring the...

  11. Impact of Electroviscosity on the Hydraulic Conductance of the Bordered Pit Membrane: A Theoretical Investigation1[C

    PubMed Central

    Santiago, Michael; Pagay, Vinay; Stroock, Abraham D.

    2013-01-01

    In perfusion experiments, the hydraulic conductance of stem segments () responds to changes in the properties of the perfusate, such as the ionic strength (), pH, and cationic identity. We review the experimental and theoretical work on this phenomenon. We then proceed to explore the hypothesis that electrokinetic effects in the bordered pit membrane (BPM) contribute to this response. In particular, we develop a model based on electroviscosity in which hydraulic conductance of an electrically charged porous membrane varies with the properties of the electrolyte. We use standard electrokinetic theory, coupled with measurements of electrokinetic properties of plant materials from the literature, to determine how the conductance of BPMs, and therefore , may change due to electroviscosity. We predict a nonmonotonic variation of with with a maximum reduction of 18%. We explore how this reduction depends on the characteristics of the sap and features of the BPM, such as pore size, density of chargeable sites, and their dissociation constant. Our predictions are consistent with changes in observed for physiological values of sap and pH. We conclude that electroviscosity is likely responsible, at least partially, for the electrolyte dependence of conductance through pits and that electroviscosity may be strong enough to play an important role in other transport processes in xylem. We conclude by proposing experiments to differentiate the impact of electroviscosity on from that of other proposed mechanisms. PMID:24014573

  12. Underground pumped storage hydroelectricity using abandoned works (deep mines or open pits) and the impact on groundwater flow

    NASA Astrophysics Data System (ADS)

    Pujades, Estanislao; Willems, Thibault; Bodeux, Sarah; Orban, Philippe; Dassargues, Alain

    2016-09-01

    Underground pumped storage hydroelectricity (UPSH) plants using open-pit or deep mines can be used in flat regions to store the excess of electricity produced during low-demand energy periods. It is essential to consider the interaction between UPSH plants and the surrounding geological media. There has been little work on the assessment of associated groundwater flow impacts. The impacts on groundwater flow are determined numerically using a simplified numerical model which is assumed to be representative of open-pit and deep mines. The main impact consists of oscillation of the piezometric head, and its magnitude depends on the characteristics of the aquifer/geological medium, the mine and the pumping and injection intervals. If an average piezometric head is considered, it drops at early times after the start of the UPSH plant activity and then recovers progressively. The most favorable hydrogeological conditions to minimize impacts are evaluated by comparing several scenarios. The impact magnitude will be lower in geological media with low hydraulic diffusivity; however, the parameter that plays the more important role is the volume of water stored in the mine. Its variation modifies considerably the groundwater flow impacts. Finally, the problem is studied analytically and some solutions are proposed to approximate the impacts, allowing a quick screening of favorable locations for future UPSH plants.

  13. Measuring the performance of two stationary interrogation systems for detecting downstream and upstream movement of PIT-tagged salmonids

    USGS Publications Warehouse

    Connolly, P.J.; Jezorek, I.G.; Martens, K.D.; Prentice, E.F.

    2008-01-01

    We tested the performance of two stationary interrogation systems designed for detecting the movement of fish with passive integrated transponder (PIT) tags. These systems allowed us to determine the direction of fish movement with high detection efficiency and high precision in a dynamic stream environment. We describe an indirect method for deriving an estimate for detection efficiency and the associated variance that does not rely on a known number of fish passing the system. By using six antennas arranged in a longitudinal series of three arrays, we attained detection efficiencies for downstream- and upstream-moving fish exceeding 96% during high-flow periods and approached 100% during low-flow periods for the two interrogation systems we tested. Because these systems did not rely on structural components, such as bridges or culverts, they were readily adaptable to remote, natural stream sites. Because of built-in redundancy, these systems were able to perform even with a loss of one or more antennas owing to dislodgement or electrical failure. However, the reduction in redundancy resulted in decreased efficiency and precision and the potential loss of ability to determine the direction of fish movement. What we learned about these systems should be applicable to a wide variety of other antenna configurations and to other types of PIT tags and transceivers.

  14. Loss of PiT-1 results in abnormal endocytosis in the yolk sac visceral endoderm.

    PubMed

    Wallingford, Mary C; Giachelli, Cecilia M

    2014-08-01

    PiT-1 protein is a transmembrane sodium-dependent phosphate (Pi) transporter. PiT-1 knock out (KO) embryos die from largely unknown causes by embryonic day (E) 12.5. We tested the hypothesis that PiT-1 is required for endocytosis in the embryonic yolk sac (YS) visceral endoderm (VE). Here we present data supporting that PiT-1 KO results in a YS remodeling defect and decreased endocytosis in the YS VE. The remodeling defect is not due to an upstream cardiomyocyte requirement for PiT-1, as SM22αCre-specific KO of PiT-1 in the developing heart and the YS mesodermal layer (ME) does not recapitulate the PiT-1 global KO phenotype. Furthermore, we find that high levels of PiT-1 protein localize to the YS VE apical membrane. Together these data support that PiT-1 is likely required in YS VE. During normal development maternal immunoglobulin (IgG) is endocytosed into YS VE and accumulates in the apical side of the VE in a specialized lysosome termed the apical vacuole (AV). We have identified a reduction in PiT-1 KO VE cell height and a striking loss of IgG accumulation in the PiT-1 KO VE. The endocytosis genes Tfeb, Lamtor2 and Snx2 are increased at the RNA level. Lysotracker Red staining reveals a loss of distinct AVs, and yolk sacs incubated ex vivo with phRODO Green Dextran for Endocytosis demonstrate a functional loss of endocytosis. As yolk sac endocytosis is controlled in part by microautophagy, but expression of LC3 had not been examined, we investigated LC3 expression during yolk sac development and found stage-specific LC3 RNA expression that is predominantly from the YS VE layer at E9.5. Normalized LC3-II protein levels are decreased in the PiT-1 KO YS, supporting a requirement for PiT-1 in autophagy in the YS. Therefore, we propose the novel idea that PiT-1 is central to the regulation of endocytosis and autophagy in the YS VE.

  15. Envenomation by a juvenile Malayan pit viper (Agkistrodon rhodostoma).

    PubMed

    Vest, D K; Kardong, K V

    1980-05-01

    Following an accidental bite inflicted by a juvenile Malayan pit viper (Agkistrodon rhodostoma), the progress of envenomation was carefully monitored and subsequent laboratory work performed to determine the amount and quality of venom injected. Even a very small amount of venom from this species is capable of inducing noticeable local symptoms including edema, subcutaneous bleeding, and throbbing. Constitutional symptoms were present but minimal. The extent of inflammation present at any given time following envenomation was found to be a more accurate diagnostic signal than the speed with which it developed. This case is similar to that of bites by juveniles of other species of viperines and crotalines and may serve to aid in the diagnosis and treatment of bites by juvenile specimens of serpents in these families.

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

    SciTech Connect

    Christensen, L.; Brady-Raap, M.

    2002-01-01

    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.

  17. Simulation of Fatigue Crack Initiation at Corrosion Pits With EDM Notches

    NASA Technical Reports Server (NTRS)

    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.

  18. Annealing to Mitigate Pitting in Electropolished Niobium Coupons and SRF Cavities

    SciTech Connect

    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.

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

    NASA Technical Reports Server (NTRS)

    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.

  20. Nucleation Of Ge 3D-islands On Pit-patterned Si Substrates

    SciTech Connect

    Novikov, P. L.; Smagina, J. V.; Vlasov, D. Yu.; Deryabin, A. S.; Kozhukhov, A. S.; Dvurechenskii, A. V.

    2011-12-23

    Joint experimental and theoretical study of Ge nanoislands growth on pit-patterned Si substrate is carried out. Si substrates that have been templated by means of electron beam lithography and reactive ion etching have been used to grow Ge by molecular-beam epitaxy. Atomic-force-microscopy studies show that at Si(100) substrate temperature 550 deg. C, Ge nanoislands are formed at the pits' edges, rather than between the pits. The effect is interpreted in terms of energy barrier, that is formed near the edge of a pit and prevents Ge transport inside the pit. By molecular dynamics calculations the value of the energy barrier 0.9 eV was obtained.

  1. Changes in energy metabolism accompanying pitting in blueberries stored at low temperature.

    PubMed

    Zhou, Qian; Zhang, Chunlei; Cheng, Shunchang; Wei, Baodong; Liu, Xiuying; Ji, Shujuan

    2014-12-01

    Low-temperature storage and transport of blueberries is widely practiced in commercial blueberry production. In this research, the storage life of blueberries was extended at low temperature, but fruit stored for 30 d at 0°C pitted after 2d at room-temperature. Fruit cellular structure and physiological parameters accompanying pitting in blueberries were changed. The objective of this research was to characterise properties of energy metabolism accompanying pitting in blueberries during storage, including adenosine phosphates and mitochondrial enzymes involved in stress responses. Physiological and metabolic disorders, changes in cell ultrastructure, energy content and ATPase enzyme activity were observed in pitting blueberries. Energy shortages and increased activity of phenylalanine ammonia lyase (PAL) and lipoxygenase (LOX) were observed in fruit kept at shelf life. The results suggested that sufficient available energy status and a stable enzymatic system in blueberries collectively contribute to improve chilling tolerance, thereby alleviating pitting and maintaining quality of blueberry fruit in long-term cold storage.

  2. Eddy current detection of pitting corrosion around fastener holes

    NASA Astrophysics Data System (ADS)

    Heida, J. H.; Thart, W. G. J.

    1995-01-01

    An evaluation of the eddy current technique for the detection and depth assessment of corrosion around fastener holes in F-16 lower wing skins is described. The corrosion type in this structure is pitting corrosion at the countersink edge of the fastener holes. Due to a corrosion clean-up limit of only 1.5 - 2.5 percent, a maximum thickness reduction in the range of 0.08 - 0.32 mm is allowed (depending on local skin thickness). This specifies the needed sensitivity for in-service corrosion inspection. In the evaluation use was made of specimens cut out of the F-16 lower wing skin structure. In total twelve specimens were exposed to an accelerated corrosion test (EXCO-test). Eddy current inspection of the specimens with installed fasteners was performed with a standard eddy scope and four different eddy current probes. After the eddy current inspection cross-sections of the twelve-specimens were made to determine the extent of pitting corrosion at the countersink edges. After evaluation of the inspection results the following conclusions can be drawn: for in-service detection of countersink edge corrosion standard visual inspection is the preferred technique regarding the simplicity, sensitivity and reliability of inspection; and for the purpose of depth assessment the eddy current technique is capable of detecting countersink edge corrosion with a depth from about 0.1 mm. Due to the corrosion clean-up limit of only 1.5 - 2.5 percent (0.08 - 0.32 mm), however, the eddy current technique is considered not applicable for in-service depth assessment of countersink edge corrosion in F-16 lower wing skins.

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

    SciTech Connect

    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.

  4. Remedial Action Work Plan Amchitka Island Mud Pit Closures

    SciTech Connect

    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.

  5. Gas cylinder disposal pit remediation waste minimization and management

    SciTech Connect

    Alas, C.A.; Solow, A.; Criswell, C.W.; Spengler, D.; Brannon, R.; Schwender, J.M.; Eckman, C.K.; Rusthoven, T.

    1995-02-01

    A remediation of a gas cylinder disposal pit at Sandia National Laboratories, New Mexico has recently been completed. The cleanup prevented possible spontaneous releases of hazardous gases from corroded cylinders that may have affected nearby active test areas at Sandia`s Technical Area III. Special waste management, safety, and quality plans were developed and strictly implemented for this project. The project was conceived from a waste management perspective, and waste minimization and management were built into the planning and implementation phases. The site layout was planned to accommodate light and heavy equipment, storage of large quantities of suspect soil, and special areas to stage and treat gases and reactive chemicals removed from the pit, as well as radiation protection areas. Excavation was a tightly controlled activity using experienced gas cylinder and reactive chemical specialists. Hazardous operations were conducted at night under lights, to allow nearby daytime operations to function unhindered. The quality assurance plan provided specific control of, and documentation for, critical decisions, as well as the record of daily operations. Both hand and heavy equipment excavation techniques were utilized. Hand excavation techniques were utilized. Hand excavation techniques allows sealed glass containers to be exhumed unharmed. In the end, several dozen thermal batteries; 5 pounds (2.3 kg) of lithium metal; 6.6 pounds (3.0 kg) of rubidium metal; several kilograms of unknown chemicals; 140 cubic yards (107 cubic meters) of thorium-contaminated soil; 270 cubic yards (205 cubic meters) of chromium-contaminated soil; and 450 gas cylinders, including 97 intact cylinders containing inert, flammable, toxic, corrosive, or oxidizing gases were removed and effectively managed to minimize waste.

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

    SciTech Connect

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

    1982-08-01

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

  7. Fish assemblages in borrow-pit lakes of the Lower Mississippi River

    USGS Publications Warehouse

    Miranda, Leandro E.; Killgore, K. J.; Hoover, J.J.

    2013-01-01

    Borrow-pit lakes encompass about a third of the lentic water habitats (by area) in the active floodplain of the Lower Mississippi River, yet little is known about their fish assemblages. We investigated whether fish assemblages supported by borrow-pit lakes resembled those in oxbow lakes to help place the ecological relevance of borrow-pit lakes in context with that of natural floodplain lakes. In all, we collected 75 fish species, including 65 species in eight borrow-pit lakes, 52 species in four riverside oxbow lakes, and 44 species in eight landside oxbow lakes. Significant differences in several species richness metrics were evident between borrow-pit lakes and landside oxbow lakes but not between borrow-pit lakes and riverside oxbow lakes. All three lake types differed in fish assemblage composition. Borrow-pit lakes and riverside oxbow lakes tended to include a greater representation of fish species that require access to diverse environments, including lentic, lotic, and palustrine habitats; fish assemblages in landside oxbow lakes included a higher representation of lacustrine species. None of the fish species collected in borrow-pit lakes was federally listed as threatened or endangered, but several were listed as species of special concern by state governments in the region, suggesting that borrow-pit lakes provide habitat for sensitive riverine and wetland fish species. Differences in fish assemblages among borrow-pit lakes were linked to engineered morphologic features, suggesting that diversity in engineering can contribute to diversity in fish assemblages; however, more research is needed to match engineering designs with fish assemblage structures that best meet conservation needs.

  8. Pit-1w may regulate prolactin gene expression in mouse testis.

    PubMed

    Maeda, Kazuki; Taniuchi, Shusuke; Takahashi, Sumio; Takeuchi, Sakae

    2012-09-01

    Pit-1 is a POU-domain transcription factor that promotes growth hormone (GH), prolactin (PRL), and thyroid-stimulating hormone β subunit (TSHβ) gene expression in the pituitary gland. Alternative splicing of Pit-1 gene transcripts has been shown to give rise to several variants with discrete transactivation properties. Recently, we identified a mouse Pit-1 w that is generated by alternative promoter usage and is expressed in a variety of tissues including the testis. Using a combination of reverse-transcription polymerase chain reaction analyses and luciferase reporter gene assays, we investigated the possible role of Pit-1 w in the mouse testis. In postnatal testicular development, the expression of Pit-1 w mRNA was significantly up-regulated between 18 and 20 days after birth when the numbers of secondary spermatocytes and spermatids have been reported to increase in mice. The PRL mRNA, but not the mRNAs for GH or TSHβ, showed intratesticular expression patterns that were similar to those of the Pit-1 w mRNA. In experimental unilaterally cryptorchid testes of adult mice, spermatid numbers were extremely low and the expression levels of both the Pit-1 w and PRL mRNAs dropped dramatically. Furthermore, in the luciferase reporter gene assays, we found that Pit-1 w specifically transactivated the PRL promoter but had no effect on the promoters of GH or TSHβ. These results suggested that Pit-1 w could be involved in the paracrine/autocrine system in mice and may be necessary for normal testicular function via its possible role in regulating PRL expression in testicular germ cells. This is the first report demonstrating the possible role of Pit-1 w in mammals. PMID:22634956

  9. Uav-Based Point Cloud Generation for Open-Pit Mine Modelling

    NASA Astrophysics Data System (ADS)

    Shahbazi, M.; Sohn, G.; Théau, J.; Ménard, P.

    2015-08-01

    Along with the advancement of unmanned aerial vehicles (UAVs), improvement of high-resolution cameras and development of vision-based mapping techniques, unmanned aerial imagery has become a matter of remarkable interest among researchers and industries. These images have the potential to provide data with unprecedented spatial and temporal resolution for three-dimensional (3D) modelling. In this paper, we present our theoretical and technical experiments regarding the development, implementation and evaluation of a UAV-based photogrammetric system for precise 3D modelling. This system was preliminarily evaluated for the application of gravel-pit surveying. The hardware of the system includes an electric powered helicopter, a 16-megapixels visible camera and inertial navigation system. The software of the system consists of the in-house programs built for sensor calibration, platform calibration, system integration and flight planning. It also includes the algorithms developed for structure from motion (SfM) computation including sparse matching, motion estimation, bundle adjustment and dense matching.

  10. Manipulation of nanoscale V-pits to optimize internal quantum efficiency of InGaN multiple quantum wells

    SciTech Connect

    Chang, Chiao-Yun; Li, Heng; Shih, Yang-Ta; Lu, Tien-Chang

    2015-03-02

    We systematically investigated the influence of nanoscale V-pits on the internal quantum efficiency (IQE) of InGaN multiple quantum wells (MQWs) by adjusting the underlying superlattices (SLS). The analysis indicated that high barrier energy of sidewall MQWs on V-pits and long diffusion distance between the threading dislocation (TD) center and V-pit boundary were crucial to effectively passivate the non-radiative centers of TDs. For a larger V-pit, the thicker sidewall MQW on V-pit would decrease the barrier energy. On the contrary, a shorter distance between the TD center and V-pit boundary would be observed in a smaller V-pit, which could increase the carrier capturing capability of TDs. An optimized V-pit size of approximately 200–250 nm in our experiment could be concluded for MQWs with 15 pairs SLS, which exhibited an IQE value of 70%.

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

    SciTech Connect

    Palmer, E.

    1995-02-01

    The Central Shops Burning/Rubble Pit 631-6G was constructed in 1951 as an unlined earthen pit in surficial sediments for disposal and incineration of potentially hazardous substances, such as metals and organic solvents.

  12. 76 FR 12096 - McCloud-Pit Project; Notice of Availability of the Final Environmental Impact Statement for the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-04

    ... Energy Regulatory Commission McCloud-Pit Project; Notice of Availability of the Final Environmental... reviewed the application for license for the McCloud-Pit Hydroelectric Project (FERC No. 2106), located on the McCloud and Pit Rivers in Shasta County, California and has prepared a final environmental...

  13. Effects of deoxidizing degree on the pitting corrosion behavior of carbon and manganese steels

    NASA Astrophysics Data System (ADS)

    Cao, Guo-Liang; Li, Guo-Min; Chen, Shan; Chang, Wan-Shun; Chen, Xue-Qun

    2011-04-01

    Nine steels with different deoxidizing degrees and two comparative steels were selected. Their pitting initiation susceptibility was compared by means of potentiodynamic polarization tests in 3wt% NaCl solution. The pit propagation rate was evaluated in artificial sea water and 3wt% sea salt solution by simulating occluded corrosion cell (SOCC) test and hanging plate test, respectively. The composition of inclusions and corrosive feature were studied by scanning electron microscopy (SEM), electron probe micro-analysis (EPMA), and optical microscopy (OM). The results indicate that sulfide inclusions in steel are the sites for pit nucleation. The sulphide inclusions vary in shape from short spindle-like to long strip-like with increasing deoxidizing degree. Under the same conditions, the lower the deoxidizing degree gets, the lower the pitting initiation susceptibility becomes, and the stronger the resistance to pit propagation exhibits. For steels with different deoxidizing degrees, their pitting initiation susceptibility is mainly influenced by thermodynamic stability, while the pit propagation rate is primarily subject to the characteristics of inclusions in steel.

  14. Optimizing the physical conditioning of the NASCAR sprint cup pit crew athlete.

    PubMed

    Ferguson, David P; Davis, Adam M; Lightfoot, J Timothy

    2015-03-01

    Stock car racing is the largest spectator sport in the United States. As a result, National Association for Stock Car Automobile Racing (NASCAR) Sprint Cup teams have begun to invest in strength and conditioning programs for their pit crew athletes. However, there is limited knowledge regarding the physical characteristics of elite NASCAR pit crew athletes, how the NASCAR Sprint Cup season affects basic physiological parameters such as body composition, and what is the most appropriate physical training program that meets the needs of a pit crew athlete. We conducted 3 experiments involving Sprint Cup motorsport athletes to determine predictors of success at the elite level, seasonal physiological changes, and appropriate physical training programs. Our results showed that hamstring flexibility (p = 0.015) and the score on the 2-tire front run test (p = 0.012) were significant predictors of NASCAR Sprint Cup Pit Crew athlete performance. Additionally, during the off season, pit crew athletes lost lean body mass, which did not return until the middle of the season. Therefore, a strength and conditioning program was developed to optimize pit crew athlete performance throughout the season. Implementation of this strength and conditioning program in 1 NASCAR Sprint Cup team demonstrated that pit crew athletes were able to prevent lean body mass loss and have increased muscle power output from the start of the season to the end of the season.

  15. Fracture Characteristics in a Disposal Pit on Mesita del Buey, Los Alamos National Laboratory

    SciTech Connect

    David T. Vaniman; Steven L. Reneau

    1998-12-01

    The characteristics of fractures in unit 2 of the Tshirege Member of the Bandelier Tuff were documented in Pit 39, a newly excavated 13.7 m deep disposal pit at Material Disposal Area G on Mesita del Buey. The average spacing between fractures is about 1.0 to 1.3 m, the average fracture aperture is about 3 to 5 mm, and the average fracture dip is about 76o to 77o. Fracture spacing and dip in Pit 39 are generally consistent with that reported from other fracture studies on the Pajarito Plateau, although the fracture apertures in Pit 39 are less than reported elsewhere. Measured fracture orientations are strongly affected by biases imparted by the orientations of the pit walls, which, combined with a small data set, make identification of potential preferred orientations dlfflcult. The most prominent fracture orientations observed in Pit 39, about E-W and N20E, are often not well represented elsewhere on the Pajarito Plateau. Fracture fills contain smectite to about 3 m depth, and calcite and opal may occur at all depths, principally associated with roots or root fossils (rhizoliths). Roots of pifion pine extend in fractures to the bottom of the pit along the north side, perhaps indicating a zone of preferred infiltration of water. Finely powdered tuff with clay-sized particles occurs within a number of fractures and may record abrasive disaggregation associated with small amounts of displacement on minor local faults.

  16. Expression of the tissue-specific transcription factor Pit-1 in the lancelet, Branchiostoma lanceolatum.

    PubMed

    Candiani, S; Pestarino, M

    1998-03-16

    Lancelets, known also as amphioxus, are protochordates that share common archetypal features with vertebrates. Recently, several developmental and molecular biology studies have pointed out homologies between anatomical structures of lancelets and vertebrates. We have studied the head region of the lancelet, Branchiostoma lanceolatum, by means of scanning electron microscopy, immunocytochemistry, and Western blotting techniques, to localize the pituitary-specific transcription factor, Pit-1. Immunoreactive Pit-1 protein has been found in cells of two typical structures of the lancelets, the Kölliker's and Hatschek's pits. Moreover, the frontal eye complex, neurons, and the rostral nerves show Pit-1 immunoreactivity. A band of 33 kilodaltons has been resolved in lancelet extracts by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and after Western blotting, the bands have been probed by a monoclonal antibody to rat Pit-1. Our results demonstrate that Pit-1 is expressed in both neurones and receptosecretory epithelial cells of adult lancelets, and that the cells lining the two pits display ultrastructural and immunocytochemical features typical of chemoreceptosecretory/olfactory- and adenohypophyseal-like structures.

  17. Evaluation of methods for attaching PIT tags and biotelemetry devices to freshwater mussels

    USGS Publications Warehouse

    Young, S.P.; Isely, J.J.

    2008-01-01

    We evaluated methods to attach PIT tags and transmitters to freshwater mussels. Mussels received externally-mounted PIT tags using cyanoacrylate or underwater epoxy, and a sub-group of those with PIT tags attached using cyanoacrylate also received dummy transmitters. Tag retention and survival were 100% after a 30 day laboratory observation period for each method. During the subsequent 18 months of field observation, underwater epoxy and cyanoacrylate proved to be adequate adhesives for attaching PIT tags and transmitters. Epoxy performed best with 100% PIT tag retention. Cyanoacrylate also provided high retention rates of PIT tags and transmitters, >90%. Mortality was minimal at 4.7% for all relocated mussels over 18 months. All mortalities were those tagged with cyanoacrylate. Three of the mortalities occurred among mussels fitted with dummy transmitters, and seven among PIT tags only. Percent recapture of the different tag/adhesive combinations ranged from 48 - 77.5% during 6- and 18-month surveys. Results suggest both adhesives provide a reliable method for external attachment of tags during freshwater mussel research; however, epoxy may be better suited because of slightly higher tag retention and reduced emersion times during attachment. Copyright ?? 2008 Malacological Society of Australasia.

  18. Antivenom cross neutralisation in a suspected Asian pit viper envenoming causing severe coagulopathy.

    PubMed

    Isbister, G K; Maduwage, K; Page, C B

    2014-11-01

    There is evidence of cross-neutralisation between common toxin groups in snake venoms and therefore the potential for antivenoms to be effective against species they are not raised against. Here we present a 49 year old female bitten by an unknown pit-viper in Nepal. She developed a venom induced consumption coagulopathy with an unrecordable international normalised ratio and undetectable fibrinogen. On return to Australia 5 days post-bite she was treated successfully with one antivenom raised against Malayan pit viper and green pit viper venoms (Haemato-polvalent antivenom from Thailand) and then subsequently with another antivenom raised against American pit-viper venoms (Antivipmyn). Presumed pit viper venom was detected in patient sera with an enzyme immunoassay against Hypnale hypnale venom. There was increased absorbance before antivenom compared to non-envenomed control samples, which then decreased after the administration of each antivenom. The recurrence of venom detected by enzyme immunoassay between antivenom doses was accompanied by a recurrence of the coagulopathy. Cross reactivity between the unknown venom and both antivenoms was supported by the fact that no venom was detected in the pre-antivenom samples after they were incubated in vitro with both antivenoms. This case and investigation of the venom and antivenoms suggest cross-neutralisation between pit vipers, including pit vipers from different continents. PMID:25178876

  19. Weathering pits as indicators of the relative age of granite surfaces in the Cairngorm mountains, Scotland

    USGS Publications Warehouse

    Hall, A.M.; Phillips, W.M.

    2006-01-01

    Weathering pits 1-140 cm deep occur on granite surfaces in the Cairngorms associated with a range of landforms, including tors, glacially exposed slabs, large erratics and blockfields. Pit depth is positively correlated with cosmogenic exposure age, and both measures show consistent relationships on individual rock landforms. Rates of pit deepening are non-linear and a best fit is provided by the sigmoidal function D = b1+ exp(b2+b3/t). The deepest pits occur on unmodified tor summits, where 10 Be exposure ages indicate that surfaces have been exposed to weathering for a minimum of 52-297 ka. Glacially exposed surfaces with pits 10-46 cm deep have given 10 Be exposure durations of 21-79 ka, indicating exposure by glacial erosion before the last glacial cycle. The combination of cosmogenic exposure ages with weathering pit depths greatly extends the area over which inferences can be made regarding the ages of granite surfaces in the Cairngorms. Well-developed weathering pits on glacially exposed surfaces in other granite areas are potential indicators of glacial erosion before the Last Glacial Maximum. ?? Swedish Society for Anthropology and Geography.

  20. Optimization of Pit Depth for Concurrent Read Only Memory-Random Access Memory Optical Disk

    NASA Astrophysics Data System (ADS)

    Aoyama, Nobuhide; Yamashita, Satoshi; Kunimatsu, Yasukiyo; Hosokawa, Tetsuo; Morimoto, Yasuaki; Suenaga, Masashi; Yoshihiro, Masafumi; Shimazaki, Katsusuke

    2004-06-01

    We have studied a concurrent read only memory-random access memory (ROM-RAM) optical disk system without laser feedback by optimizing pit depth. When the pit depth was 47 nm (optical depth about 1/11 λ) and the pit width 0.45 μm, about 8% jitter in both pit and magneto-optical (MO) signals was obtained with a 785 nm wavelength laser diode and 0.55 NA objective lens by employing magnetic-field-modulation (MFM) MO recording. Both pit data and MO data were recorded with eight to fourteen modulation (EFM) code with a minimum mark length of 0.83 μm and a track pitch of 1.6 μm and thus the areal density is comparable to 1.3 GB for φ 120 mm single sided disk. By the optimization of the pit depth, sufficient system margins for practical use were obtained without laser feed back for the simultaneous reproduction of both pit and MO signals.

  1. Design of the Hoisting System for D-Zero Collision Hall Pit

    SciTech Connect

    Rucinski, Russell A.; /Fermilab

    2002-02-28

    A hoisting rail system has been designed for lifting loads from the north sidewalk of the D0 collision hall into the collision hall pit. This engineering note documents the design. The hoisting system was conceived primarily to aid in getting heavy loads into the pit during short (less than a few days) accesses. The typical use for the hoist will be to lift a BLS power supply (120 lbs) and carrier (16 lbs) from a roll around cart on the sidewalk and onto a similar cart in the collision hall pit. The hoist system will alleviate the need for two persons to carry this heavy load up and down a narrow (24-inch) staircase. The hoisting system has a designed lift rating of 150 lbs. All members and components are well within a conservative safety factor when subjected to this loading at it's worst possible configuration, that is with it's boom cantilevered out 8 feet from the base rail. See the hoisting rail assembly sketch (in the hand calculations section) and the picture inserted below to get an orientation of the device. The hoisting system is designed using BLine 'unistrut' system components. The hoist consists of a 'base' rail that is fastened to either the northeast or northwest air handler platforms. This fixed base rail has (2) two sided trolley assemblies inserted into it's lower unistrut member. One assembly is locked in place on the base rail. Another is locked in place on the lower 'boom' rail. The trolley assemblies are free wheeling which allows boom movement in the north-south direction about 7 1/2 feet within the fixed base rail. An electric hoist hangs from the 'boom' rail on a single trolley. The hoisting system meets Fermilab Environment and Safety Manual chapter 5021 entitled 'Overhead cranes hoists and rigging'. Inclusive in that requirement is that it meets the applicable Fermilab 'work smart standards' of ANSI B30.11-1998 'Monorails and underhung cranes', and ANSI B30.16-1998 'Overhead hoists (underhung)'. The design criteria for the structural

  2. Central Pit and Dome Formation as Seen in Occator Crater, Ceres

    NASA Astrophysics Data System (ADS)

    Schenk, Paul M.; Buczkowski, Debra; Scully, Jennifer E. C.; De Sanctis, Maria Cristina; Schmidt, Britney E.; O'Brien, David P.; Hiesinger, Harald; Sizemore, Hanna G.; Ammannito, Eleonora; Raymond, Carol; Russell, Christopher T.; Dawn Science Team

    2016-10-01

    Dawn mapping of Ceres revealed that central depressions (or pits) are common in craters >75 km. The best preserved of these is Occator (D~92 km), where the pit is associated with a major bright deposit dominated by carbonates. The pit is ~9 km wide, 600-800 m deep and flanked by asymmetric massifs 0.7 to 1.3 km high. The pit is partially filled by a fractured central dome ~3 km wide and 700 m high. Fracturing could have been due to dome inflation by "magma" or by subsurface freezing of ice. Within the bright material, two color units are mapped, including a paler surface unit and a more yellowish to reddish unit exposed within the most fractured parts of the dome surface and at small bright spots, at least some of which could be post-Occator small craters. Some bright materials form as discrete small spots midslope along the pit wall and others avoid small hills, suggesting partial topographic control. Stratigraphic relations are ambiguous but suggest formation of a smooth carapace some meters thick that was subsequently disrupted by fractures crossing the floor of Occator, and by uplift of the dome surface. Pit and dome morphologies, including dome fracturing are potentially analogous to central pits and domes in many craters on Ganymede and Callisto, suggesting some commonality in formation processes. The absence of center pits or domes on Saturnian satellites could be related to much lower temperatures on those bodies. The prominence of central pits and domes on Ceres confirms the importance of volatile materials, mostly likely water ice, in the outer layers of Ceres, especially as compared to Vesta.

  3. Atypical pit craters on Mars: new insights from THEMIS, CTX and HiRISE observations

    USGS Publications Warehouse

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

    2015-01-01

    More than 100 pit craters in the Tharsis region of Mars exhibit morphologies, diameters and thermal behaviors that diverge from the much larger bowl-shaped pit craters that occur in most regions across Mars. These Atypical Pit Craters (APCs) generally have sharp and distinct rims, vertical or overhanging walls that extend down to their floors, surface diameters of ~50-350 m, and high depth-to-diameter (d/D) ratios that are usually greater than 0.3 (which is an upper-range value for impacts and bowl-shaped pit craters), and can exceed values of 1.8. Observations by the Mars Odyssey THermal Emission Imaging System (THEMIS) show that APC floor temperatures are warmer at night, and fluctuate with much lower diurnal amplitudes than nearby surfaces or adjacent bowl-shaped pit craters. Kīlauea volcano, Hawai'i, hosts pit craters that formed through subsurface collapse into active volcanic dikes, resulting in pits that can appear morphologically analogous to either APCs or bowl-shaped pit craters. Partially-drained dikes are sometimes exposed within the lower walls and floors of these terrestrial APC analogs and can form extensive cave systems with unique microclimates. Similar caves in martian pit craters are of great interest for astrobiology. This study uses new observations by the Mars Reconnaissance Orbiter (MRO) High Resolution Imaging Science Experiment (HiRISE) and Context Camera (CTX) to refine previous work where seven APCs were described from lower-resolution THEMIS visible-wavelength (VIS) observations. Here, we identify locations of 115 APCs, map their distribution across the Tharsis region, characterize their internal morphologies with high-resolution observations, and discuss possible formation mechanisms.

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

    NASA Astrophysics Data System (ADS)

    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.

  5. Heart rate and core temperature responses of elite pit crews during automobile races.

    PubMed

    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.

  6. Pit Latrines and Their Impacts on Groundwater Quality: A Systematic Review

    PubMed Central

    Polizzotto, Matthew L.

    2013-01-01

    Background: Pit latrines are one of the most common human excreta disposal systems in low-income countries, and their use is on the rise as countries aim to meet the sanitation-related target of the Millennium Development Goals. There is concern, however, that discharges of chemical and microbial contaminants from pit latrines to groundwater may negatively affect human health. Objectives: Our goals were to a) calculate global pit latrine coverage, b) systematically review empirical studies of the impacts of pit latrines on groundwater quality, c) evaluate latrine siting standards, and d) identify knowledge gaps regarding the potential for and consequences of groundwater contamination by latrines. Methods: We used existing survey and population data to calculate global pit latrine coverage. We reviewed the scientific literature on the occurrence of contaminants originating from pit latrines and considered the factors affecting transport of these contaminants. Data were extracted from peer-reviewed articles, books, and reports identified using Web of ScienceSM, PubMed, Google, and document reference lists. Discussion: We estimated that approximately 1.77 billion people use pit latrines as their primary means of sanitation. Studies of pit latrines and groundwater are limited and have generally focused on only a few indicator contaminants. Although groundwater contamination is frequently observed downstream of latrines, contaminant transport distances, recommendations based on empirical studies, and siting guidelines are variable and not well aligned with one another. Conclusions: In order to improve environmental and human health, future research should examine a larger set of contextual variables, improve measurement approaches, and develop better criteria for siting pit latrines. PMID:23518813

  7. In situ vitrification demonstration at Pit 1, Oak Ridge National Laboratory. Volume 2: Site characterization report of the Pit 1 area

    SciTech Connect

    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).

  8. Sea floor gouges and pits in deep fjords, Baffin Island: Possible mammalian feeding traces

    NASA Astrophysics Data System (ADS)

    Hein, F. J.; Syvitski, J. P. M.

    1989-06-01

    Pisces submersible dives within Baffin Island fjords have revealed the common occurrence of pits on the sea floor, at water depths between 40 and 326 m. The size of these pits are in the decimeter to meter range. Through indirect evidence (by comparison of morphologic features to pits or gouges of known origin) they are believed to be feeding traces of narwhal, beluga, or bowhead whales. If so, they are the deepest mammalian feeding traces yet reported. Bioerosion by large foraging mammals may be a more common sea floor process than previously thought.

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

    SciTech Connect

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

    2002-05-11

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

  10. Modeling pitting corrosion of iron exposed to alkaline solutions containing nitrate and nitrite

    NASA Astrophysics Data System (ADS)

    Chen, Lifeng

    2001-07-01

    Pitting corrosion could be extremely serious for dilute high-level radioactive waste stored or processed in carbon steel tanks at the Savannah River Site. In these solutions, nitrate is an aggressive ion with respect to pitting of carbon steel while nitrite can be used as an inhibitor. Excessive additions of nitrite increase the risk of generating unstable nitrogen compounds during waste processing, and insufficient additions of nitrite could increase the risk of corrosion-induced failure. Thus there are strong incentives to obtain a fundamental understanding of the role of nitrite in pitting corrosion prevention with these solution chemistries. In this dissertation, both a 1-D and a 2-D model are used to study the pitting mechanism as a function of nitrite/nitrate ratios. The 1-D model used BAND(J) to test a reaction mechanism for the passivation behavior by comparing the predicted Open Circuit Potential (OCP) with OCP data from experiments at different NO2-/NO3- ratio. The model predictions are compared with Cyclic Potentiodynamic Polarization (CPP) experiments. A 2-D model was developed for the propagation of a pit in iron by writing subroutines for finite element software of GAMBIT and FIDAP. Geometrically distributed anodic and cathodic reactions are assumed. The results show three partial explanations describing the inhibition influence of nitrite to iron corrosion: the competing reduction reaction of nitrate to nitrite, the formation of Fe(OH)+, and the function of the porous film. The current distributions and the effect of porosity of the film on pH are also explained. The calculation results also show that rate of pit growth decreases as the pit diameter increases until it reaches a constant value. The profile of the local current density on the pit wall is parabolic for small pits and it changes to a linear distribution for large pits. The model predicts that addition of nitrite will decrease the production of ferrous ions and those can prevent iron from

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

    SciTech Connect

    Roy, A.K.; Fleming, D.L.; Gordon, S.R.

    1996-12-01

    Electrochemical cyclic potentiodynamic polarization experiments were performed on several candidate waste package container materials to evaluate their susceptibility to pitting corrosion at 90 degrees C in aqueous environments relevant to the potential underground high-level nuclear waste repository. Results indicate that of all the materials tested, Alloy C-22 and Ti Grade-12 exhibited the maximum corrosion resistance, showing no pitting or observable corrosion in any environment tested. Efforts were also made to study the effect of chloride ion concentration and pH on the measured corrosion potential (Ecorr), critical pitting and protection potential values.

  12. Fabrication of mitigation pits for improving laser damage resistance in dielectric mirrors by femtosecond laser machining

    SciTech Connect

    Wolfe, Justin E.; Qiu, S. Roger; Stolz, Christopher J.

    2011-03-20

    Femtosecond laser machining is used to create mitigation pits to stabilize nanosecond laser-induced damage in multilayer dielectric mirror coatings on BK7 substrates. In this paper, we characterize features and the artifacts associated with mitigation pits and further investigate the impact of pulse energy and pulse duration on pit quality and damage resistance. Our results show that these mitigation features can double the fluence-handling capability of large-aperture optical multilayer mirror coatings and further demonstrate that femtosecond laser macromachining is a promising means for fabricating mitigation geometry in multilayer coatings to increase mirror performance under high-power laser irradiation.

  13. Inhibiting pitting corrosion in carbon steel exposed to dilute radioactive waste slurries

    SciTech Connect

    Zapp, P.E.; Hobbs, D.T.

    1991-01-01

    Dilute caustic high-level radioactive waste slurries can induce pitting corrosion in carbon steel. Cyclic potentiodynamic polarization tests were conducted in simulated and actual waste solutions to determine minimum concentrations of sodium nitrate which inhibit pitting in ASTM A537 class 1 steel exposed to these solutions. Susceptibility to pitting was assessed through microscopic inspection of specimens and inspection of polarization scans. Long-term coupon immersion tests were conducted to verify the nitrite concentrations established by the cyclic potentiodynamic polarization tests. The minimum effective nitrite concentration is expressed as a function of the waste nitrate concentration and temperature.

  14. Further development of a predictive pitting model for gears: Improvements in the life prediction analysis

    NASA Astrophysics Data System (ADS)

    Blake, J. W.; Draper, C. F.

    1994-04-01

    A predictive pitting model for gear design applications was recently developed by Blake and Cheng. Life estimates were based on predicting the growth of surface-breaking cracks leading to pit formation. While trends predicted by the model reflected observed behavior, estimated lives were lower than expected. The crack growth model has been improved by modifying the original shear-driven, two-dimensional propagation model to reflect three-dimensional cracks driven by both shear and lubricant pressure effects. Resistance to crack growth due to friction between the crack faces has also been considered. These changes have led to a net increase in predicted lives, which better reflects observed pitting behavior.

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

    NASA Astrophysics Data System (ADS)

    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.

  16. Misfit dislocation gettering by substrate pit-patterning in SiGe films on Si(001)

    SciTech Connect

    Grydlik, Martyna; Groiss, Heiko; Brehm, Moritz; Schaeffler, Friedrich; Boioli, Francesca; Montalenti, Francesco; Miglio, Leo; Gatti, Riccardo; Devincre, Benoit

    2012-07-02

    We show that suitable pit-patterning of a Si(001) substrate can strongly influence the nucleation and the propagation of dislocations during epitaxial deposition of Si-rich Si{sub 1-x}Ge{sub x} alloys, preferentially gettering misfit segments along pit rows. In particular, for a 250 nm layer deposited by molecular beam epitaxy at x{sub Ge} = 15%, extended film regions appear free of dislocations, by atomic force microscopy, as confirmed by transmission electron microscopy sampling. This result is quite general, as explained by dislocation dynamics simulations, which reveal the key role of the inhomogeneous distribution in stress produced by the pit-patterning.

  17. Comprehensive experimental study on prevention of land subsidence caused by dewatering in deep foundation pit with hanging waterproof curtain

    NASA Astrophysics Data System (ADS)

    Yang, T. L.; Yan, X. X.; Wang, H. M.; Huang, X. L.; Zhan, G. H.

    2015-11-01

    Land subsidence caused by dewatering of deep foundations pit has currently become the focus of prevention and control of land subsidence in Shanghai. Because of the reliance on deep foundation dewatering pit projects, two comprehensive test sites were established to help prevent land subsidence. Through geological environmental monitoring during dewatering of a deep foundation pit, the analysis of the relation between artesian water level and soil subsidence, some basic features of land subsidence caused by dewatering of deep foundation pits are elucidated. The results provide a scientific basis for prevention and control of land subsidence caused by dewatering in deep foundation pits.

  18. KW basin backwash pit sludge measurement/video

    SciTech Connect

    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.

  19. EARTHSAWtm IN-SITU CONTAINMENT OF PITS AND TRENCHES

    SciTech Connect

    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.

  20. The PIT MkV pulsed inductive thruster

    NASA Technical Reports Server (NTRS)

    Dailey, C. Lee; Lovberg, Ralph H.

    1993-01-01

    The pulsed inductive thruster (PIT) is an electrodeless, magnetic rocket engine that can operate with any gaseous propellant. A puff of gas injected against the face of a flat (spiral) coil is ionized and ejected by the magnetic field of a fast-rising current pulse from a capacitor bank discharge. Single shot operation on an impulse balance has provided efficiency and I(sub sp) data that characterize operation at any power level (pulse rate). The 1-m diameter MkV thruster concept offers low estimated engine mass at low powers, together with power capability up to more than 1 MW for the 1-m diameter design. A 20 kW design estimate indicates specific mass comparable to Ion Engine specific mass for 10,000 hour operation, while a 100,000 hour design would have a specific mass 1/3 that of the Ion Engine. Performance data are reported for ammonia and hydrazine. With ammonia, at 32 KV coil voltage, efficiency is a little more than 50 percent from 4000 to more than 8000 seconds I(sub sp). Comparison with data at 24 and 28 kV indicates that a wider I(sub sp) range could be achieved at higher coil voltages, if required for deep space missions.

  1. Underground Pumped Storage Hydropower using abandoned open pit mines: influence of groundwater seepage on the system efficiency

    NASA Astrophysics Data System (ADS)

    Pujades, Estanislao; Bodeux, Sarah; Orban, Philippe; Dassargues, Alain

    2016-04-01

    Pumped Storage Hydropower (PSH) plants can be used to manage the production of electrical energy according to the demand. These plants allow storing and generating electricity during low and high demand energy periods, respectively. Nevertheless, PSH plants require a determined topography because two reservoirs located at different heights are needed. At sites where PSH plants cannot be constructed due to topography requirements (flat regions), Underground Pumped Storage Hydropower (UPSH) plants can be used to adjust the electricity production. These plants consist in two reservoirs, the upper one is located at the surface (or at shallow depth) while the lower one is underground (or deeper). Abandoned open pit mines can be used as lower reservoirs but these are rarely isolated. As a consequence, UPSH plants will interact with surrounding aquifers exchanging groundwater. Groundwater seepage will modify hydraulic head inside the underground reservoir affecting global efficiency of the UPSH plant. The influence on the plant efficiency caused by the interaction between UPSH plants and aquifers will depend on the aquifer parameters, underground reservoir properties and pumping and injection characteristics. The alteration of the efficiency produced by the groundwater exchanges, which has not been previously considered, is now studied numerically. A set of numerical simulations are performed to establish in terms of efficiency the effects of groundwater exchanges and the optimum conditions to locate an UPSH plant.

  2. Improvements, Evaluation, and Application of 1D Vetem Inversion and Development and Application of 3D Vetem Inversion to Waste Pits at The Idaho National Engineering and Environmental Laboratory

    SciTech Connect

    Weng Cho Chew

    2004-10-27

    The project aim was the improvement, evaluation, and application of one dimensional (1D) inversion and development and application of three dimensional (3D) inversion to processing of data collected at waste pits at the Idaho National Engineering and Environmental Laboratory. The inversion methods were intended mainly for the Very Early Time Electromagnetic (VETEM) system which was designed to improve the state-of-the-art of electromagnetic imaging of the shallow (0 to about 5m) subsurface through electrically conductive soils.

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

    NASA Technical Reports Server (NTRS)

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

    2012-01-01

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

  4. Mitigated Transfer Line Leaks that Result in Surface Pools and Spray Leaks into Pits

    SciTech Connect

    HEY, B.E.

    1999-12-07

    This analysis provides radiological and toxicological consequence calculations for postulated mitigated leaks during transfers of six waste compositions. Leaks in Cleanout Boxes equipped with supplemental covers and leaks in pits are analyzed.

  5. Morphological analysis of pits formed on Al 2024-T3 in chloride aqueous solution

    NASA Astrophysics Data System (ADS)

    Silva, J. W. J.; Bustamante, A. G.; Codaro, E. N.; Nakazato, R. Z.; Hein, L. R. O.

    2004-09-01

    It has been used a new image analysis method, based on segmentation by shape parameters, for pits morphology examination from Al 2024 aluminum-copper alloy in chloride aqueous solution. Corrosion behavior of this alloys in naturally aerated 3.5% NaCl solution has been investigated through open circuit potential measurements. Afterwards, pits have been characterized by image analysis taking density and size measurements right from corroded surfaces. Morphological investigation has been conducted for profiles, cut orthogonally from mean surface planes, and observed through light microscopy. Image analysis data could demonstrate that pits are wider than deep, evoluting for conical, quasi-conical or irregular shapes. Most pits have presented a quasi-conical morphology, but the wider ones have evoluted to an irregular shape influenced by sub-surface microstructure. Image analysis based on shape segmentation could enhance the differences on morphological behavior.

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

    SciTech Connect

    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.

  7. Extraction and characterization of montmorency (Prunus cerasus L.) sour cherry pit oil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Montmorency sour cherry (Prunus cerasus L.) pit oil was extracted and characterized by various methods including: gas chromatography (GC), liquid chromatography coupled with mass spectrometry (LC-MS), nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), differential scanning calorime...

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

    SciTech Connect

    Not Available

    1984-08-01

    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.

  9. Remote monitoring of fish in small streams: A unified approach using PIT tags

    USGS Publications Warehouse

    Zydlewski, G.B.; Horton, G.; Dubreuil, T.; Letcher, B.; Casey, S.; Zydlewski, J.

    2006-01-01

    Accurate assessments of fish populations are often limited by re-observation or recapture events. Since the early 1990s, passive integrated transponders (PIT tags) have been used to understand the biology of many fish species. Until recently, PIT applications in small streams have been limited to physical recapture events. To maximize recapture probability, we constructed PIT antenna arrays in small streams to remotely detect individual fish. Experiences from two different laboratories (three case studies) allowed us to develop a unified approach to applying PIT technology for enhancing data assessments. Information on equipment, its installation, tag considerations, and array construction is provided. Theoretical and practical definitions are introduced to standardize metrics for assessing detection efficiency. We demonstrate how certain conditions (stream discharge, vibration, and ambient radio frequency noise) affect the detection efficiency and suggest that by monitoring these conditions, expectations of efficiency can be modified. We emphasize the importance of consistently estimating detection efficiency for fisheries applications.

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

    SciTech Connect

    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.

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

    NASA Astrophysics Data System (ADS)

    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

  12. Pitted terrain on Vesta and implications for the presence of volatiles.

    PubMed

    Denevi, B W; Blewett, D T; Buczkowski, D L; Capaccioni, F; Capria, M T; De Sanctis, M C; Garry, W B; Gaskell, R W; Le Corre, L; Li, J-Y; Marchi, S; McCoy, T J; Nathues, A; O'Brien, D P; Petro, N E; Pieters, C M; Preusker, F; Raymond, C A; Reddy, V; Russell, C T; Schenk, P; Scully, J E C; Sunshine, J M; Tosi, F; Williams, D A; Wyrick, D

    2012-10-12

    We investigated the origin of unusual pitted terrain on asteroid Vesta, revealed in images from the Dawn spacecraft. Pitted terrain is characterized by irregular rimless depressions found in and around several impact craters, with a distinct morphology not observed on other airless bodies. Similar terrain is associated with numerous martian craters, where pits are thought to form through degassing of volatile-bearing material heated by the impact. Pitted terrain on Vesta may have formed in a similar manner, which indicates that portions of the surface contain a relatively large volatile component. Exogenic materials, such as water-rich carbonaceous chondrites, may be the source of volatiles, suggesting that impactor materials are preserved locally in relatively high abundance on Vesta and that impactor composition has played an important role in shaping the asteroid's geology.

  13. STS-32 crewmembers use water hose during exercises at JSC fire training pit

    NASA Technical Reports Server (NTRS)

    1989-01-01

    STS-32 Commander Daniel C. Brandenstein (left) and Pilot James D. Wetherbee handle water hose during fire training exercises conducted at JSC Fire Training Pit across from the Gilruth Center Bldg 207.

  14. Description of work for 100-DR-2 Operable Unit Vadose Drilling/test pits

    SciTech Connect

    Naiknimbalkar, N.

    1993-08-01

    This report describes the scope of work for the boreholes/test pits of the 100-DR-2 Operable Unit. Sampling and field activities include: Soil screening; geologic sampling; soil sampling (physical property); analytical sampling and depths; and geophysical logging.

  15. Gear Fault Detection Effectiveness as Applied to Tooth Surface Pitting Fatigue Damage

    NASA Technical Reports Server (NTRS)

    Lewicki, David G.; Dempsey, Paula J.; Heath, Gregory F.; Shanthakumaran, Perumal

    2009-01-01

    A study was performed to evaluate fault detection effectiveness as applied to gear tooth pitting fatigue damage. Vibration and oil-debris monitoring (ODM) data were gathered from 24 sets of spur pinion and face gears run during a previous endurance evaluation study. Three common condition indicators (RMS, FM4, and NA4) were deduced from the time-averaged vibration data and used with the ODM to evaluate their performance for gear fault detection. The NA4 parameter showed to be a very good condition indicator for the detection of gear tooth surface pitting failures. The FM4 and RMS parameters performed average to below average in detection of gear tooth surface pitting failures. The ODM sensor was successful in detecting a significant amount of debris from all the gear tooth pitting fatigue failures. Excluding outliers, the average cumulative mass at the end of a test was 40 mg.

  16. Controls by saturation state on etch pit formation during calcite dissolution

    NASA Astrophysics Data System (ADS)

    Teng, H. Henry

    2004-01-01

    Dissolution experiments were conducted on {101¯4} cleavage faces of calcite at various under-saturations to determine how the saturation state controls etch pit formation. Experimental observations were made by using in situ fluid cell Atomic Force Microscopy. Three dissolution modes were observed. When the saturation index Ω > 0.541, no etch pit formation was seen and dissolution primarily occurred at existing steps. When Ω decreased to Ω c = 0.541-0.410, the first visible pits appeared and continuous reduction in saturation state slowly increased the pit density on terraces while dissolution simultaneously proceeded at step edges. Finally, when the saturation state fell below Ω max = ˜0.007, a precipitous increase in pit density took place that sharply contrasted to the ordered fashion of pit formation observed at saturation conditions above this level. These observations are interpreted to be two-dimensional and unassisted pit formation at Ω < ˜0.007, defect- and step-assisted dissolution in between Ω = 0.541 and 0.007, and existing step-induced dissolution for Ω > 0.541. The values of Ω c are in good agreement with the dislocation theory's predicted critical under-saturations for pit formation at line dislocations. The occurrence of Ω max is not directly predicted but is a logical consequence of dissolution thermodynamics. These findings suggest that (1) dissolution near and far from equilibrium (i.e., Ω > Ω c, Ω < Ω max) is not controlled by dislocations, therefore (2) dislocation density should significantly impact dissolution rate only in the saturation range of Ω max < Ω < Ω c; (3) dissolution kinetics and chemical affinity of dissolution reactions should have a non-linear relationship: at sufficiently close to equilibrium, when dislocations cannot open up to form etch pits, the dissolution kinetics will be limited by the number of existing steps; at far from equilibrium, when pits are able to form in defect-free regions, the dissolution

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

    PubMed

    Walter, W David; Anderson, Charles W; Vercauteren, Kurt C

    2012-01-01

    Methods to individually mark and identify free-ranging wildlife without trapping and handling would be useful for a variety of research and management purposes. The use of Passive Integrated Transponder technology could be an efficient method for collecting data for mark-recapture analysis and other strategies for assessing characteristics about populations of various wildlife species. Passive Integrated Transponder tags (PIT) have unique numbered frequencies and have been used to successfully mark and identify mammals. We tested for successful injection of PIT and subsequent functioning of PIT into gelatin blocks using 4 variations of a prototype dart. We then selected the prototype dart that resulted in the least depth of penetration in the gelatin block to assess the ability of PIT to be successfully implanted into muscle tissue of white-tailed deer (Odocoileus virginianus) post-mortem and long-term in live, captive Rocky Mountain elk (Cervus elaphus). The prototype dart with a 12.7 mm (0.5 inch) needle length and no powder charge resulted in the shallowest mean (± SD) penetration depth into gelatin blocks of 27.0 mm (± 5.6 mm) with 2.0 psi setting on the Dan-Inject CO(2)-pressured rifle. Eighty percent of PIT were successfully injected in the muscle mass of white-tailed deer post-mortem with a mean (± SD) penetration depth of 22.2 mm (± 3.8 mm; n = 6). We injected PIT successfully into 13 live, captive elk by remote delivery at about 20 m that remained functional for 7 months. We successfully demonstrated that PIT could be remotely delivered in darts into muscle mass of large mammals and remain functional for >6 months. Although further research is warranted to fully develop the technique, remote delivery of PIT technology to large mammals is possible using prototype implant darts. PMID:22984572

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

    PubMed

    Walter, W David; Anderson, Charles W; Vercauteren, Kurt C

    2012-01-01

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

  19. Collective Motion of Humans in Mosh and Circle Pits at Heavy Metal Concerts

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

    Human collective behavior can vary from calm to panicked depending on social context. Using videos publicly available online, we study the highly energized collective motion of attendees at heavy metal concerts. We find these extreme social gatherings generate similarly extreme behaviors: a disordered gaslike state called a mosh pit and an ordered vortexlike state called a circle pit. Both phenomena are reproduced in flocking simulations demonstrating that human collective behavior is consistent with the predictions of simplified models.

  20. The Experience of Implementation of Innovative Technology of Quarry Waste Water Purifying in Kuzbass Open Pit

    NASA Astrophysics Data System (ADS)

    Lesin, Yu V.; Hellmer, M. C.

    2016-08-01

    Among all industries in Kuzbass (Western Siberia, Russia) the coal industry provides the most environmental threat. However, the construction of new and maintenance of existing open pit mines do not often correspond to the tasks of improving the environmental safety of surface mining. So the article describes the use of innovative quarry waste water purifying technology implemented in Kuzbass open pit mine «Shestaki». This technology is based on using artificial filter arrays made of overburden rock.

  1. The Python pit organ: imaging and immunocytochemical analysis of an extremely sensitive natural infrared detector.

    PubMed

    Grace, M S; Church, D R; Kelly, C T; Lynn, W F; Cooper, T M

    1999-01-01

    The Python infrared-sensitive pit organ is a natural infrared imager that combines high sensitivity, ambient temperature function, microscopic dimensions, and self-repair. We are investigating the spectral sensitivity and signal transduction process in snake infrared-sensitive neurons, neither of which is understood. For example, it is unknown whether infrared receptor neurons function on a thermal or a photic mechanism. We imaged pit organs in living Python molurus and Python regius using infrared-sensitive digital video cameras. Pit organs were significantly more absorptive and/or emissive than surrounding tissues in both 3-5 microns and 8-12 microns wavelength ranges. Pit organs exhibited greater absorption/emissivity in the 8-12 microns range than in the 3-5 microns range. To directly test the relationship between photoreceptors and pit organ infrared-sensitive neurons, we performed immunocytochemistry using antisera directed against retinal photoreceptor opsins. Retinal photoreceptors were labeled with antisera specific for retinal opsins, but these antisera failed to label terminals of infrared-sensitive neurons in the pit organ. Infrared-receptive neurons were also distinguished from retinal photoreceptors on the basis of their calcium-binding protein content. These results indicate that the pit organ absorbs infrared radiation in two major atmospheric transmission windows, one of which (8-12 microns) matches emission of targeted prey, and that infrared receptors are biochemically distinct from retinal photoreceptors. These results also provide the first identification of prospective biochemical components of infrared signal transduction in pit organ receptor neurons.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    SciTech Connect

    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.

  4. The Python pit organ: imaging and immunocytochemical analysis of an extremely sensitive natural infrared detector.

    PubMed

    Grace, M S; Church, D R; Kelly, C T; Lynn, W F; Cooper, T M

    1999-01-01

    The Python infrared-sensitive pit organ is a natural infrared imager that combines high sensitivity, ambient temperature function, microscopic dimensions, and self-repair. We are investigating the spectral sensitivity and signal transduction process in snake infrared-sensitive neurons, neither of which is understood. For example, it is unknown whether infrared receptor neurons function on a thermal or a photic mechanism. We imaged pit organs in living Python molurus and Python regius using infrared-sensitive digital video cameras. Pit organs were significantly more absorptive and/or emissive than surrounding tissues in both 3-5 microns and 8-12 microns wavelength ranges. Pit organs exhibited greater absorption/emissivity in the 8-12 microns range than in the 3-5 microns range. To directly test the relationship between photoreceptors and pit organ infrared-sensitive neurons, we performed immunocytochemistry using antisera directed against retinal photoreceptor opsins. Retinal photoreceptors were labeled with antisera specific for retinal opsins, but these antisera failed to label terminals of infrared-sensitive neurons in the pit organ. Infrared-receptive neurons were also distinguished from retinal photoreceptors on the basis of their calcium-binding protein content. These results indicate that the pit organ absorbs infrared radiation in two major atmospheric transmission windows, one of which (8-12 microns) matches emission of targeted prey, and that infrared receptors are biochemically distinct from retinal photoreceptors. These results also provide the first identification of prospective biochemical components of infrared signal transduction in pit organ receptor neurons. PMID:10028649

  5. Rhegmatogenous retinal detachment with a pit of the optic nerve head.

    PubMed

    Traboulsi, E I; Pilkerton, A R

    1988-04-01

    A 56-year-old myope developed a retinal detachment of the macular area and the temporal quadrants in his left eye that harbored a temporally-located pit of the optic nerve head. Under anesthesia a small peripheral retinal break was identified, and the retina was reattached successfully using cryotherapy and a limited scleral buckling procedure. Peripheral retinal breaks should be searched for in myopic eyes with optic pits and retinal detachments involving peripheral retinal quadrants.

  6. SPERTI Reactor Pit Building (PER605) under construction. Poured concrete foundation ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    SPERT-I Reactor Pit Building (PER-605) under construction. Poured concrete foundation will enclosure a "Pit" into which the reactor vessel will be placed. Steel framework has been erected. To left of view is instrument cell (PER-606), constructed of concrete block. Photographer: R.G. Larsen. Date: April 22, 1955. INEEL negative no. 55-1000 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

  7. Chronoamperometric study of mild steel pitting in sodium sulfide aqueous solution

    SciTech Connect

    Otero, T.F.; Achucarro, C. . Dept. de Ciencia y Tecnologia de Polimeros)

    1994-08-01

    Mild steel samples were studied by chronoamperometry in sodium sulfide (Na[sub 2]S) aqueous solution. Pit nucleation and growth also were monitored by optical microscopy. The influence of variables such as temperature, polarization potential, surface roughness, the presence of electrochemically generated oxide layers, and the simultaneous presence of potassium hydroxide (KOH) was studied. The influence of each parameter on pit shape and growth was reviewed. Different reactions and competitive processes were proposed based on the experimental results.

  8. Evaluation of Remote Delivery of Passive Integrated Transponder (PIT) Technology to Mark Large Mammals

    PubMed Central

    Walter, W. David; Anderson, Charles W.; VerCauteren, Kurt C.

    2012-01-01

    Methods to individually mark and identify free-ranging wildlife without trapping and handling would be useful for a variety of research and management purposes. The use of Passive Integrated Transponder technology could be an efficient method for collecting data for mark-recapture analysis and other strategies for assessing characteristics about populations of various wildlife species. Passive Integrated Transponder tags (PIT) have unique numbered frequencies and have been used to successfully mark and identify mammals. We tested for successful injection of PIT and subsequent functioning of PIT into gelatin blocks using 4 variations of a prototype dart. We then selected the prototype dart that resulted in the least depth of penetration in the gelatin block to assess the ability of PIT to be successfully implanted into muscle tissue of white-tailed deer (Odocoileus virginianus) post-mortem and long-term in live, captive Rocky Mountain elk (Cervus elaphus). The prototype dart with a 12.7 mm (0.5 inch) needle length and no powder charge resulted in the shallowest mean (± SD) penetration depth into gelatin blocks of 27.0 mm (±5.6 mm) with 2.0 psi setting on the Dan-Inject CO2-pressured rifle. Eighty percent of PIT were successfully injected in the muscle mass of white-tailed deer post-mortem with a mean (± SD) penetration depth of 22.2 mm (±3.8 mm; n = 6). We injected PIT successfully into 13 live, captive elk by remote delivery at about 20 m that remained functional for 7 months. We successfully demonstrated that PIT could be remotely delivered in darts into muscle mass of large mammals and remain functional for >6 months. Although further research is warranted to fully develop the technique, remote delivery of PIT technology to large mammals is possible using prototype implant darts. PMID:22984572

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

    SciTech Connect

    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.

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

    PubMed

    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.

  11. Effect of chloride concentration on the pitting and repassivation potentials of reinforcing steel in alkaline solutions

    SciTech Connect

    Li, L.

    1999-11-01

    Reinforcing steel bars ({approximately}12mm diameter and 150mm long) were used in cyclic polarization tests in saturated Ca(OH){sub 2} solution and simulated concrete pore solution (SPS) with various levels of sodium chloride addition. Below a limiting chloride level ({approximately}O.004M [Cl{sup {minus}}] in Ca(OH){sub 2} solution and {approximately}0.4M [Cl{sup {minus}}] in SPS solution), steel was not found to undergo pitting corrosion even if it was polarized to the oxygen evolution potential ({approximately}O.6V/SCE). At higher NaCl addition, pitting corrosion could often be initiated but the pitting potential was non-deterministic to a great extent. In Ca(OH){sub 2} solution the average pitting potential was found to be strongly dependent on chloride concentration when [Cl{sup {minus}}]{ge}0.008M. In SPS solution, the average pitting potential was almost independent of the chloride concentration when [Cl{sup {minus}}]{ge}0.8M. The repassivation potential was found to be a strong function of the severity of corrosion attack that has occurred on the steel surface before repassivation, rather than a function of the chloride content of the bulk solution. The pitting tendency in chloride-containing SPS and Ca(OH){sub 2} solutions was interpreted on a statistical basis. The threshold thus determined good agreement with other values reported in the literature.

  12. Pits confined in ultrathin cerium(IV) oxide for studying catalytic centers in carbon monoxide oxidation

    NASA Astrophysics Data System (ADS)

    Sun, Yongfu; Liu, Qinghua; Gao, Shan; Cheng, Hao; Lei, Fengcai; Sun, Zhihu; Jiang, Yong; Su, Haibin; Wei, Shiqiang; Xie, Yi

    2013-11-01

    Finding ideal material models for studying the role of catalytic active sites remains a great challenge. Here we propose pits confined in an atomically thin sheet as a platform to evaluate carbon monoxide catalytic oxidation at various sites. The artificial three-atomic-layer thin cerium(IV) oxide sheet with approximately 20% pits occupancy possesses abundant pit-surrounding cerium sites having average coordination numbers of 4.6 as revealed by X-ray absorption spectroscopy. Density-functional calculations disclose that the four- and five-fold coordinated pit-surrounding cerium sites assume their respective role in carbon monoxide adsorption and oxygen activation, which lowers the activation barrier and avoids catalytic poisoning. Moreover, the presence of coordination-unsaturated cerium sites increases the carrier density and facilitates carbon monoxide diffusion along the two-dimensional conducting channels of surface pits. The atomically thin sheet with surface-confined pits exhibits lower apparent activation energy than the bulk material (61.7 versus 122.9 kJ mol-1), leading to reduced conversion temperature and enhanced carbon monoxide catalytic ability.

  13. Infrared-sensitive pit organ and trigeminal ganglion in the crotaline snakes

    PubMed Central

    2011-01-01

    The infrared (IR) receptors in the pit organ of crotaline snakes are very sensitive to temperature. The sensitivity to IR radiation is much greater in crotaline snakes than in boid snakes because they have a thermosensitive membrane suspended in a pair of pits that comprise the pit organ. The vasculature of the pit membrane, which is located near IR-sensitive terminal nerve masses, the IR receptors, supplies the blood necessary to provide cooling and the energy and oxygen that the IR receptors require. The ophthalmic and maxillary branches of the trigeminal nerve innervate the pit membrane. In crotaline snakes, the trigeminal ganglion (TG) is divided into the ophthalmic and maxillomandibular ganglia; a prominent septum further separates the two divisions of the maxillomandibular ganglion. The TG neurons in the ophthalmic ganglion and the maxillary division of the maxillomandibular ganglion relay IR sensation to the brain. This article reviews the IR-sensitive pit organ and trigeminal sensory system structures in crotaline snakes. PMID:21519544

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

    PubMed

    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

  15. 3D Modeling of Lacus Mortis Pit Crater with Presumed Interior Tube Structure

    NASA Astrophysics Data System (ADS)

    Hong, Ik-Seon; Yi, Yu; Yu, Jaehyung; Haruyama, Junichi

    2015-06-01

    When humans explore the Moon, lunar caves will be an ideal base to provide a shelter from the hazards of radiation, meteorite impact, and extreme diurnal temperature differences. In order to ascertain the existence of caves on the Moon, it is best to visit the Moon in person. The Google Lunar X Prize(GLXP) competition started recently to attempt lunar exploration missions. Ones of those groups competing, plan to land on a pit of Lacus Mortis and determine the existence of a cave inside this pit. In this pit, there is a ramp from the entrance down to the inside of the pit, which enables a rover to approach the inner region of the pit. In this study, under the assumption of the existence of a cave in this pit, a 3D model was developed based on the optical image data. Since this model simulates the actual terrain, the rendering of the model agrees well with the image data. Furthermore, the 3D printing of this model will enable more rigorous investigations and also could be used to publicize lunar exploration missions with ease.

  16. Pits confined in ultrathin cerium(IV) oxide for studying catalytic centers in carbon monoxide oxidation.

    PubMed

    Sun, Yongfu; Liu, Qinghua; Gao, Shan; Cheng, Hao; Lei, Fengcai; Sun, Zhihu; Jiang, Yong; Su, Haibin; Wei, Shiqiang; Xie, Yi

    2013-01-01

    Finding ideal material models for studying the role of catalytic active sites remains a great challenge. Here we propose pits confined in an atomically thin sheet as a platform to evaluate carbon monoxide catalytic oxidation at various sites. The artificial three-atomic-layer thin cerium(IV) oxide sheet with approximately 20% pits occupancy possesses abundant pit-surrounding cerium sites having average coordination numbers of 4.6 as revealed by X-ray absorption spectroscopy. Density-functional calculations disclose that the four- and five-fold coordinated pit-surrounding cerium sites assume their respective role in carbon monoxide adsorption and oxygen activation, which lowers the activation barrier and avoids catalytic poisoning. Moreover, the presence of coordination-unsaturated cerium sites increases the carrier density and facilitates carbon monoxide diffusion along the two-dimensional conducting channels of surface pits. The atomically thin sheet with surface-confined pits exhibits lower apparent activation energy than the bulk material (61.7 versus 122.9 kJ mol(-1)), leading to reduced conversion temperature and enhanced carbon monoxide catalytic ability.

  17. Pits, a protein interacting with Ttk69 and Sin3A, has links to histone deacetylation

    PubMed Central

    Liaw, Gwo-Jen

    2016-01-01

    Histone deacetylation plays an important role in transcriptional repression. Previous results showed that the genetic interaction between ttk and rpd3, which encodes a class I histone deacetylase, is required for tll repression. This study investigated the molecular mechanism by which Ttk69 recruits Rpd3. Using yeast two-hybrid screening and datamining, one novel protein was found that weakly interacts with Ttk69 and Sin3A, designated as Protein interacting with Ttk69 and Sin3A (Pits). Pits protein expressed in the early stages of embryos and bound to the region of the tor response element in vivo. Expanded tll expression patterns were observed in embryos lacking maternal pits activity and the expansion was not widened by reducing either maternal ttk or sin3A activity. However, in embryos with simultaneously reduced maternal pits and sin3A activities or maternal pits, sin3A and ttk activities, the proportions of the embryos with expanded tll expression were significantly increased. These results indicate that all three gene activities are involved in tll repression. Level of histone H3 acetylation in the tll proximal region was found to be elevated in embryo with reduced these three gene activities. In conclusion, Ttk69 causes the histone deacetylation-mediated repression of tll via the interaction of Pits and Sin3A. PMID:27622813

  18. Comparison study of solid-liquid separation techniques for oilfield pit closures

    SciTech Connect

    Wojtanowicz, A.C.; Field, S.D.; Osterman, M.C.

    1986-01-01

    Extensive bench-scale and full-scale experiments were conducted at the LSU Solids Control Environmental Laboratory in order to evaluate application of the solids-liquid separation technology to oilfield waste pit volume reduction. The experiments addressed chemical conditioning of various pit slurries such as water-base and oil-base mud reserve pit slurries, mixed sludge from offshore operations, and oil production pit slurry. Effective treatment was found for the majority of the waste samples with pH adjustment and with nonionic and low-charge anionic, high molecular weight polymers. Ultimate dewaterability of various samples was determined by use of the belt press bench simulator. Bench simulators of belt press filtration, vacuum filtration and centrifuge sedimentation were used for design and optimization of the full-scale tests. Alternative solid-liquid separation techniques such as vacuum filtration, belt press filtration, screw press filtration and centrifuging were pilot-tested using field-size equipment and 200 bbls samples of water-base mud, reserve pit slurry and production pit sludge. The test data were analyzed at various operating conditions using a new graphical technique. Also, four typical oilfield solid-bowl centrifuges and a modern solid-bowl dewatering decanter were compared in a series of full-scale tests. Finally a preliminary process study on the mechanism of centrifuge separation of flocculated sludges was performed.

  19. Central pit and dome craters - Exposing the interiors of Ganymede and Callisto

    NASA Technical Reports Server (NTRS)

    Schenk, Paul M.

    1993-01-01

    Central pit craters on Ganymede and Callisto are an unusual crater class, perhaps related to the unusual properties of water ice. The domes and pits form rapidly, on the time scale of the impact itself, rather than by long-term, post-impact intrusion or extrusion. The bright domes in pit craters are most simply explained as the uplift and exposure of relatively ice-rich material from depths of approximately 3.5 to 5 km during impact. The unusual pit morphology on icy satellites may be the result of impact into crust that is mechanically much weaker at shallow depth than on rocky bodies such as the moon. Because crater morphology is strongly dependent on ice-rock composition, the similarity of pit and dome dimensions on Ganymede and Callisto indicates that the structure and rheology of the crusts of these bodies are very similar, and have been for several billion years. Pit crater morphology indicates that the crusts of both satellites are probably ice-rich and differentiated.

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

    PubMed Central

    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

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

    NASA Astrophysics Data System (ADS)

    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.

  2. Central pit and dome craters - Exposing the interiors of Ganymede and Callisto

    NASA Astrophysics Data System (ADS)

    Schenk, P. M.

    1993-04-01

    Central pit craters on Ganymede and Callisto are an unusual crater class, perhaps related to the unusual properties of water ice. The domes and pits form rapidly, on the time scale of the impact itself, rather than by long-term, post-impact intrusion or extrusion. The bright domes in pit craters are most simply explained as the uplift and exposure of relatively ice-rich material from depths of approximately 3.5 to 5 km during impact. The unusual pit morphology on icy satellites may be the result of impact into crust that is mechanically much weaker at shallow depth than on rocky bodies such as the moon. Because crater morphology is strongly dependent on ice-rock composition, the similarity of pit and dome dimensions on Ganymede and Callisto indicates that the structure and rheology of the crusts of these bodies are very similar, and have been for several billion years. Pit crater morphology indicates that the crusts of both satellites are probably ice-rich and differentiated.

  3. Pit-1 inhibits BRCA1 and sensitizes human breast tumors to cisplatin and vitamin D treatment

    PubMed Central

    Seoane, Samuel; Arias, Efigenia; Sigueiro, Rita; Sendon-Lago, Juan; Martinez-Ordoñez, Anxo; Castelao, Esteban; Eiró, Noemí; Garcia-Caballero, Tomás; Macia, Manuel; Lopez-Lopez, Rafael; Maestro, Miguel; Vizoso, Francisco; Mouriño, Antonio; Perez-Fernandez, Roman

    2015-01-01

    The POU class 1 homeobox 1 (POU1F1, also known as Pit-1), pertaining to the Pit-Oct-Unc (POU) family of transcription factors, has been related to tumor growth and metastasis in breast. However, its role in response to breast cancer therapy is unknown. We found that Pit-1 down-regulated DNA-damage and repair genes, and specifically inhibited BRCA1 gene expression, sensitizing breast cancer cells to DNA-damage agents. Administration of 1α, 25-dihydroxy-3-epi-vitamin D3 (3-Epi, an endogenous low calcemic vitamin D metabolite) reduced Pit-1 expression, and synergized with cisplatin, thus, decreasing cell proliferation and apoptosis in vitro, and reducing tumor growth in vivo. In addition, fifteen primary cultures of human breast tumors showed significantly decreased proliferation when treated with 3-Epi+cisplatin, compared to cisplatin alone. This response positively correlated with Pit-1 levels. Our findings demonstrate that high levels of Pit-1 and reduced BRCA1 levels increase breast cancer cell susceptibility to 3-Epi+cisplatin therapy. PMID:25992773

  4. Pits, a protein interacting with Ttk69 and Sin3A, has links to histone deacetylation.

    PubMed

    Liaw, Gwo-Jen

    2016-01-01

    Histone deacetylation plays an important role in transcriptional repression. Previous results showed that the genetic interaction between ttk and rpd3, which encodes a class I histone deacetylase, is required for tll repression. This study investigated the molecular mechanism by which Ttk69 recruits Rpd3. Using yeast two-hybrid screening and datamining, one novel protein was found that weakly interacts with Ttk69 and Sin3A, designated as Protein interacting with Ttk69 and Sin3A (Pits). Pits protein expressed in the early stages of embryos and bound to the region of the tor response element in vivo. Expanded tll expression patterns were observed in embryos lacking maternal pits activity and the expansion was not widened by reducing either maternal ttk or sin3A activity. However, in embryos with simultaneously reduced maternal pits and sin3A activities or maternal pits, sin3A and ttk activities, the proportions of the embryos with expanded tll expression were significantly increased. These results indicate that all three gene activities are involved in tll repression. Level of histone H3 acetylation in the tll proximal region was found to be elevated in embryo with reduced these three gene activities. In conclusion, Ttk69 causes the histone deacetylation-mediated repression of tll via the interaction of Pits and Sin3A. PMID:27622813

  5. Dynamin recruitment and membrane scission at the neck of a clathrin-coated pit

    PubMed Central

    Cocucci, Emanuele; Gaudin, Raphaël; Kirchhausen, Tom

    2014-01-01

    Dynamin, the GTPase required for clathrin-mediated endocytosis, is recruited to clathrin-coated pits in two sequential phases. The first is associated with coated pit maturation; the second, with fission of the membrane neck of a coated pit. Using gene-edited cells that express dynamin2-EGFP instead of dynamin2 and live-cell TIRF imaging with single-molecule EGFP sensitivity and high temporal resolution, we detected the arrival of dynamin at coated pits and defined dynamin dimers as the preferred assembly unit. We also used live-cell spinning-disk confocal microscopy calibrated by single-molecule EGFP detection to determine the number of dynamins recruited to the coated pits. A large fraction of budding coated pits recruit between 26 and 40 dynamins (between 1 and 1.5 helical turns of a dynamin collar) during the recruitment phase associated with neck fission; 26 are enough for coated vesicle release in cells partially depleted of dynamin by RNA interference. We discuss how these results restrict models for the mechanism of dynamin-mediated membrane scission. PMID:25232009

  6. Electronic structures of GeSi nanoislands grown on pit-patterned Si(001) substrate

    SciTech Connect

    Ye, Han Yu, Zhongyuan

    2014-11-15

    Patterning pit on Si(001) substrate prior to Ge deposition is an important approach to achieve GeSi nanoislands with high ordering and size uniformity. In present work, the electronic structures of realistic uncapped pyramid, dome, barn and cupola nanoislands grown in (105) pits are systematically investigated by solving Schrödinger equation for heavy-hole, which resorts to inhomogeneous strain distribution and nonlinear composition-dependent band parameters. Uniform, partitioned and equilibrium composition profile (CP) in nanoisland and inverted pyramid structure are simulated separately. We demonstrate the huge impact of composition profile on localization of heavy-hole: wave function of ground state is confined near pit facets for uniform CP, at bottom of nanoisland for partitioned CP and at top of nanoisland for equilibrium CP. Moreover, such localization is gradually compromised by the size effect as pit filling ratio or pit size decreases. The results pave the fundamental guideline of designing nanoislands on pit-patterned substrates for desired applications.

  7. Membrane tension regulates clathrin-coated pit dynamics

    NASA Astrophysics Data System (ADS)

    Liu, Allen

    2014-03-01

    Intracellular organization depends on close communication between the extracellular environment and a network of cytoskeleton filaments. The interactions between cytoskeletal filaments and the plasma membrane lead to changes in membrane tension that in turns help regulate biological processes. Endocytosis is thought to be stimulated by low membrane tension and the removal of membrane increases membrane tension. While it is appreciated that the opposing effects of exocytosis and endocytosis have on keeping plasma membrane tension to a set point, it is not clear how membrane tension affects the dynamics of clathrin-coated pits (CCPs), the individual functional units of clathrin-mediated endocytosis. Furthermore, although it was recently shown that actin dynamics counteracts membrane tension during CCP formation, it is not clear what roles plasma membrane tension plays during CCP initiation. Based on the notion that plasma membrane tension is increased when the membrane area increases during cell spreading, we designed micro-patterned surfaces of different sizes to control the cell spreading sizes. Total internal reflection fluorescence microscopy of living cells and high content image analysis were used to quantify the dynamics of CCPs. We found that there is an increased proportion of CCPs with short (<20s) lifetime for cells on larger patterns. Interestingly, cells on larger patterns have higher CCP initiation density, an effect unexpected based on the conventional view of decreasing endocytosis with increasing membrane tension. Furthermore, by analyzing the intensity profiles of CCPs that were longer-lived, we found CCP intensity decreases with increasing cell size, indicating that the CCPs are smaller with increasing membrane tension. Finally, disruption of actin dynamics significantly increased the number of short-lived CCPs, but also decreased CCP initiation rate. Together, our study reveals new mechanistic insights into how plasma membrane tension regulates

  8. Bacillus vini sp. nov. isolated from alcohol fermentation pit mud.

    PubMed

    Ma, Kedong; Chen, Xiaorong; Guo, Xiang; Wang, Yanwei; Wang, Huimin; Zhou, Shan; Song, Jinlong; Kong, Delong; Zhu, Jie; Dong, Weiwei; He, Mingxiong; Hu, Guoquan; Zhao, Bingqiang; Ruan, Zhiyong

    2016-08-01

    A novel aerobic, Gram-stain-positive, sporogenous, rod-shaped bacterium, designated LAM0415(T), was isolated from an alcohol fermentation pit mud sample collected from Sichuan Luzhou-flavour liquor enterprise in China. The isolate was found to be able to grow at NaCl concentrations of 0-10 % (w/v) (optimum: 1.0 %), 10-50 °C (optimum: 30-35 °C) and pH 3.0-10.0 (optimum: 7.0-8.0). Phylogenetic analysis of 16S rRNA gene sequences indicated that the new isolate belonged to the genus Bacillus and was closely related to Bacillus sporothermodurans DSM 10599(T) and Bacillus oleronius DSM 9356(T), with 98.4 and 97.2 % sequence similarity, respectively. The DNA-DNA hybridization values between strain LAM0415(T) and the two reference strains were 33.3 ± 1.2 and 42.8 ± 0.8 %, respectively. The genomic DNA G+C content was 35.2 mol% as determined by the T m method. The major fatty acids were determined to be iso-C15:0, anteiso-C15:0 and anteiso-C17:0. The predominant menaquinones were identified as MK7 and MK8. The major polar lipids were found to be diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, one unidentified phospholipid and four unidentified glycolipids. The diagnostic amino acid of the cell wall peptidoglycan was determined to be meso-diaminopimelic acid. On the basis of its phenotypic, phylogenetic and chemotaxonomic characteristics, strain LAM0415(T) (=ACCC 06413(T) = JCM 19841(T)) represents the type strain of a novel species of the genus Bacillus, for which the name Bacillus vini sp. nov. is proposed. PMID:27055557

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

    SciTech Connect

    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).

  10. Androgens and doping tests: genetic variation and pit-falls

    PubMed Central

    Rane, Anders; Ekström, Lena

    2012-01-01

    The large variation in disposition known for most drugs is also true for anabolic androgenic steroids. Genetic factors are probably the single most important cause of this variation. Further, there are reasons to believe that there is a corresponding variation in efficacy of doping agents. Doped individuals employ a large variety of doping strategies in respect of choice of substance, dose, dose interval, duration of treatment and use of other drugs for enforcement of effects or correction of side effects. Metabolic steps up-stream and down-stream of testosterone are genetically variable and contribute substantially to the variation in disposition of testosterone, the most common doping agent in sports and in society. Large inter- and intra-ethnic variation in testosterone glucuronidation and excretion is described as well as the pit-falls in evaluation of testosterone doping test results. The hydrolysis and bioactivation of testosterone enanthate is also genetically variable yielding a 2–3 fold variation in excretion rate and serum concentration, thereby implicating a substantial variation in ‘efficacy’ of testosterone. Given this situation it is logical to adopt the new findings in the doping control programme. The population based cut-off level for the testosterone : epitestosterone ratio should be replaced by a Bayesian interpretation of consecutive tests in the same individual. When combined with the above genetic information the sensitivity of the test is considerably improved. The combination of the three approaches should reduce the rate of falsely negative or positive results and the number of expensive follow-up tests, stipulated by the World Anti-Doping Agency. PMID:22506612

  11. Los Alamos National Laboratory W76 Pit Tube Lifetime Study

    SciTech Connect

    Abeln, Terri G.

    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. Avian mortality at oil pits in the United States: A review of the problem and efforts for its solution.

    PubMed

    Trail, Pepper W

    2006-10-01

    Oil production operations produce waste fluids that may be stored in pits, open tanks, and other sites accessible to wildlife. Birds visit these fluid-filled pits and tanks ("oil pits"), which often resemble water sources, and may become trapped and die. The US Fish and Wildlife Service (USFWS) has a program to reduce these impacts by locating problem pits, documenting mortality of protected wildlife species, and seeking cleanup or corrective action at problem pits with the help of state and federal agencies regulating the oil industry. Species identification and verification of protected status for birds recovered from oil pits are performed at the USFWS National Fish and Wildlife Forensics Laboratory. From 1992 to 2005, a minimum of 2060 individual birds were identified from remains recovered from oil pits, representing 172 species from 44 families. The taxonomic and ecological diversity of these birds indicates that oil pits pose a threat to virtually all species of birds that encounter them. Ninety-two percent of identified bird remains belonged to protected species. Most remains identified at the Forensics Laboratory were from passerines, particularly ground-foraging species. Based on Forensics Laboratory and USFWS field data, oil pits currently cause the deaths of 500,000-1 million birds per year. Although law enforcement and industry efforts have produced genuine progress on this issue, oil pits remain a significant source of mortality for birds in the United States.

  13. An assessment of hydrogeochemical computer codes applied toward modeling and predicting post-mining pit water geochemistry

    SciTech Connect

    Bird, D.A.; Lyons, W.B. . Hydrology Program); Miller, G.C. . Dept. of Environmental Resource Sciences)

    1993-04-01

    Geochemists for the mining industry utilize a variety of computer codes to model and predict post-mining pit water chemogenesis. This study surveys several of the PC-supported hydrogeochemical codes, applies them to specific open pit mine scenarios, and evaluates their suitability to predicting post-mining pit and groundwater hydro-geochemistry. The prediction of pit water geochemistry is important because of the potential adverse effects of mine drainage, which include acidity, trace metal contamination, pit water stratification, and sludge accumulation. The WATEQ codes of the USGS can calculate speciation and saturation states of a pit water or groundwater sample, but are not designed to model forward rock/water reactions. NETPATH can calculate the chemical mass transfer (inverse modeling) that has occurred during rock/water interaction, but again is not designed to model forward pit water chemogenesis. Several mining industry modelers use EPA's MINTEQA2 code, which has shown to be very flexible with its large database and ability to model adsorption. Reaction path codes, like PHREEQE and EQ3/6, can model reactions on an incremental basis as the pit fills over time, but also may require much user manipulation. New coupled codes like PHREEQM and HYDROGEOCHEM can simulate movement and reaction of groundwater through the aquifer as it approaches and inundates the pit. One aspect of post-mining hydrogeochemical modeling that has received little attention is the effect groundwater will have down gradient after it flows from the pit into the aquifer.

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

    PubMed

    Strømman, G; Rosseland, B O; Skipperud, L; Burkitbaev, L M; Uralbekov, B; Heier, L S; Salbu, B

    2013-09-01

    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 (234)U/(238)U 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 (238)U 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.).

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

    SciTech Connect

    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.

  16. Retention of resin-based filled and unfilled pit and fissure sealants: A comparative clinical study

    PubMed Central

    Reddy, V. Rajashekar; Chowdhary, Nagalakshmi; Mukunda, K. S.; Kiran, N. K.; Kavyarani, B. S.; Pradeep, M. C.

    2015-01-01

    Background and Objectives: The most caries-susceptible period of a permanent first molar tooth is the eruption phase, during which the enamel is not fully matured and it is usually difficult for the child to clean the erupting tooth surfaces. Sealing occlusal pits and fissures with resin-based pit and fissure sealants is a proven method to prevent occlusal caries. The difference in the viscosity of the sealants differs in the penetration into pit and fissures and abrasive wear resistance property due to the addition of filler particles. The present study was conducted to evaluate and compare the retention of the resin-based filled (Helioseal F, Ivoclar Vivadent) and unfilled (Clinpro, 3M ESPE) pit and fissure sealants, which is important for their effectiveness. Materials and Methods: Fifty-six children between the age group of 6 and 9 years, with all four newly erupted permanent first molars were selected. Sealants were applied randomly using split mouth design technique on permanent first molars. Evaluation of sealant retention was performed at regular intervals over 12 months, using Simonsen's criteria at 2nd, 4th, 6th, 8th, 10th and 12th month. The results were subjected to statistical analysis. Results: At the end of our study period (12th month), 53.57% showed complete retention, 37.50% showed partial retention, and 8.83% showed complete missing of resin-based filled (Helioseal F) pit and fissure sealant. And, 64.29% showed complete retention, 32.14% showed partial retention, and 3.57% showed complete missing of resin-based unfilled (Clinpro) pit and fissure sealant. This difference in retention rates between filled and unfilled pit and fissure sealants was not statistically significant. Conclusion: The difference in retention rates between Helioseal F and Clinpro was not statistically significant, but Clinpro (unfilled) sealant showed slightly higher retention rates and clinically better performance than Helioseal F (filled). PMID:25821368

  17. Adsorbate-driven morphological changes on Cu(111) nano-pits

    SciTech Connect

    Mudiyanselage, K.; Xu, F.; Hoffmann, F. M.; Hrbek, J.; Waluyo, I.; Boscoboinik, J. A.; Stacchiola, D. J.

    2014-12-09

    Adsorbate-driven morphological changes of pitted-Cu(111) surfaces have been investigated following the adsorption and desorption of CO and H. The morphology of the pitted-Cu(111) surfaces, prepared by Ar+ sputtering, exposed a few atomic layers deep nested hexagonal pits of diameters from 8 to 38 nm with steep step bundles. The roughness of pitted-Cu(111) surfaces can be healed by heating to 450-500 K in vacuum. Adsorption of CO on the pitted-Cu(111) surface leads to two infrared peaks at 2089-2090 and 2101-2105 cm-1 for CO adsorbed on under-coordinated sites in addition to the peak at 2071 cm-1 for CO adsorbed on atop sites of the close-packed Cu(111) surface. CO adsorbed on under-coordinated sites is thermally more stable than that of atop Cu(111) sites. Annealing of the CO-covered surface from 100 to 300 K leads to minor changes of the surface morphology. In contrast, annealing of a H covered surface to 300 K creates a smooth Cu(111) surface as deduced from infrared data of adsorbed CO and scanning tunnelling microscopy (STM) imaging. The observation of significant adsorbate-driven morphological changes with H is attributed to its stronger modification of the Cu(111) surface by the formation of a sub-surface hydride with a hexagonal structure, which relaxes into the healed Cu(111) surface upon hydrogen desorption. These morphological changes occur ~150 K below the temperature required for healing of the pitted-Cu(111) surface by annealing in vacuum. In contrast, the adsorption of CO, which only interacts with the top-most Cu layer and desorbs by 160 K, does not significantly change the morphology of the pitted-Cu(111) surface.

  18. Adsorbate-driven morphological changes on Cu(111) nano-pits

    DOE PAGES

    Mudiyanselage, K.; Xu, F.; Hoffmann, F. M.; Hrbek, J.; Waluyo, I.; Boscoboinik, J. A.; Stacchiola, D. J.

    2014-12-09

    Adsorbate-driven morphological changes of pitted-Cu(111) surfaces have been investigated following the adsorption and desorption of CO and H. The morphology of the pitted-Cu(111) surfaces, prepared by Ar+ sputtering, exposed a few atomic layers deep nested hexagonal pits of diameters from 8 to 38 nm with steep step bundles. The roughness of pitted-Cu(111) surfaces can be healed by heating to 450-500 K in vacuum. Adsorption of CO on the pitted-Cu(111) surface leads to two infrared peaks at 2089-2090 and 2101-2105 cm-1 for CO adsorbed on under-coordinated sites in addition to the peak at 2071 cm-1 for CO adsorbed on atop sitesmore » of the close-packed Cu(111) surface. CO adsorbed on under-coordinated sites is thermally more stable than that of atop Cu(111) sites. Annealing of the CO-covered surface from 100 to 300 K leads to minor changes of the surface morphology. In contrast, annealing of a H covered surface to 300 K creates a smooth Cu(111) surface as deduced from infrared data of adsorbed CO and scanning tunnelling microscopy (STM) imaging. The observation of significant adsorbate-driven morphological changes with H is attributed to its stronger modification of the Cu(111) surface by the formation of a sub-surface hydride with a hexagonal structure, which relaxes into the healed Cu(111) surface upon hydrogen desorption. These morphological changes occur ~150 K below the temperature required for healing of the pitted-Cu(111) surface by annealing in vacuum. In contrast, the adsorption of CO, which only interacts with the top-most Cu layer and desorbs by 160 K, does not significantly change the morphology of the pitted-Cu(111) surface.« less

  19. Electrical conductivity of microwave heated polyaniline nanotubes and possible mechanism of microwave absorption by materials.

    PubMed

    Murai, Takahiro; Fukasawa, Ryo; Muraoka, Tohru; Takauchi, Hiroyuki; Gotoh, Yasuo; Takizawa, Tokihiro; Matsuse, Takehiro

    2009-01-01

    In the course of experiments to perform deprotonation and carbonization of doped polyaniline (PANI) nanotubes (NTs) by irradiating directly 2.45 GHz microwave (MW) in our microwave heating system (MWHS), we have discovered that the PANI-NTs self heat by absorbing the MW but the temperature of the PANI-NTs stops rising around 300 degrees C in spite of the heightened MW power Furthermore, we have found that the MW irradiated PANI-NTs have transferred from electrical conductor to insulator depending on the temperature of the PANI-NTs. By measuring electron spin resonance (ESR) spectra of the MW heated PANI-NTs, the existence of the unpaired electrons is shown to have a strong correlation between the degree of MW absorption and the transition in the electrical conductivities. In order to deprotonate and carbonize further the PANI-NTs, we have performed heat treatment for the PANI-NTs up to a temperature (T(HT)) of about 1200 degrees C in the same MWHS using carbon fiber which self heats by absorbing MW. The chemical transformations in the PANI-NTs induced by the heat treatments are discussed by measuring the X-ray photoelectron spectroscopy (XPS) spectra. Finally, the temperature dependence of electrical conductivities of the PANI-NTs are measured in order to investigate the mechanism of electrical conduction of the heat treated PANI-NTs. PMID:21384721

  20. Design approaches in quarrying and pit-mining reclamation

    USGS Publications Warehouse

    Arbogast, Belinda F.

    1999-01-01

    art show a celebration of beauty and experience -- abstract geology. The last design approach combines art and science in a human-nature ecosystem termed integration. With environmental concerns, an operating or reclaimed mine site can no longer be considered isolated from its surroundings. Site analysis of mine works needs to go beyond site-specific information and relate to the regional context of the greater landscape. Understanding design approach can turn undesirable features (mines and pits) into something perceived as desirable by the public.